FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Fields, RE AF Fields, RE TI Shocked by electrostatics SO SCIENTIFIC AMERICAN LA English DT Letter C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fields, RE (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD FEB PY 2003 VL 288 IS 2 BP 10 EP 10 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 636MQ UT WOS:000180460200008 ER PT J AU Wallbrink, PJ Martin, CE Wilson, CJ AF Wallbrink, PJ Martin, CE Wilson, CJ TI Quantifying the contributions of sediment, sediment-P and fertiliser-P from forested, cultivated and pasture areas at the landuse and catchment scale using fallout radionuclides and geochemistry SO SOIL & TILLAGE RESEARCH LA English DT Article DE diffuse sources; landuse; fallout radionuclides; phosphorus; sediment delivery; soil erosion; Eutrophication; geochemistry ID NEW-SOUTH-WALES; SUSPENDED SEDIMENT; GEOLOGICAL SAMPLES; BANK EROSION; RIVER; PHOSPHORUS; AUSTRALIA; TRANSPORT; CESIUM-137; PB-210 AB In this paper we use a combination of fallout nuclides and geochemistry to determine the contributions of sediment and sediment bound phosphorus (sed-P) from the major diffuse sources in the Bundella Creek catchment (8700 ha), NSW, Australia. Sources include surface erosion from cultivated, pasture and steep forested land as well as subsoil erosion from channels and gullies. We determine these contributions to the <10 mu m fraction of deposited sediments. Concentrations of P were higher in the surface soils of each landuse than the underlying subsoils, and erosion from these contributed more to offsite sediment-P (similar to 60%) than did subsoil erosion at the individual landuse scale. At the catchment outlet, the amount of surface sediment eroded from cultivated lands was a factor of similar to 84 higher than from pastures; the steep forested lands contributed similar to 9 times more than pastures. Sed-P eroded from cultivated land was similar to 42 times higher than from pasturelands; the forests were similar to 8 times greater than from pastures. At the catchment outlet the largest contribution of sediment (similar to 70%) and sed-P (similar to 62%) was from subsoil erosion of gullies and channels within and between the different landuse areas. There was little contribution of sediment or sed-P at the catchment scale from surface erosion of pastures. Concentrations of P were highest in 'storm event' suspended sediment samples taken from the pasture and cultivated areas without gullies. In a suite of samples selected for their high P contents, fertiliser P was detected in two storm event suspended sediment samples and one deposited sediment sample, using the ratio of Nd/P. This suggests fertiliser P may be transported-off landsurfaces with sediments and contribute to offsite sediment-P concentrations in some situations. However, the fertiliser contributions were episodic and variable; and probably influenced by particle size selectivity as well as timing of fertiliser application with respect to size and occurrence of subsequent rainfall. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CSIRO, Div Land & Water, Canberra, ACT 2601, Australia. Cooperat Res Ctr Catchment Hydrol, Canberra, ACT 2601, Australia. Univ Otago, Dept Geol, Dunedin, New Zealand. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wallbrink, PJ (reprint author), CSIRO, Div Land & Water, Christian Bldg,POB 1666, Canberra, ACT 2601, Australia. EM peter.wallbrink@cbr.csiro.au RI Wallbrink, Peter/A-2794-2011; Wallbrink, Peter/A-7107-2017 NR 42 TC 49 Z9 54 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-1987 J9 SOIL TILL RES JI Soil Tillage Res. PD FEB PY 2003 VL 69 IS 1-2 BP 53 EP 68 AR PII S0167-1987(02)00128-9 DI 10.1016/S0167-1987(02)00128-9 PG 16 WC Soil Science SC Agriculture GA 648PE UT WOS:000181159100006 ER PT J AU Coffey, GW Hardy, J Pedersen, LR Rieke, PC Thomsen, EC Walpole, M AF Coffey, GW Hardy, J Pedersen, LR Rieke, PC Thomsen, EC Walpole, M TI Electrochemical properties of lanthanum strontium aluminum ferrites for the oxygen reduction reaction SO SOLID STATE IONICS LA English DT Article DE solid oxide fuel cell; cathode; oxygen reduction reaction; lanthanum strontium ferrite; lanthanum strontium aluminum ferrite ID YTTRIA-STABILIZED ZIRCONIA; SOFC CATHODE MATERIALS; THERMODYNAMIC PROPERTIES; CHEMICAL-REACTIVITY; OXIDE; ELECTROLYTE; CELLS; MN; CO; LA AB The oxygen reduction reaction was studied on the La1 - xSrxAlyFe1 - yO3 (x=0.2, y=0.1, 0.2, 0.3, 0.4) s stem by cyclic voltametry and electronic conductivity. Activation energies for the bulk and film conductivities were determined. Tafel analysis afforded the activation energies "from the temperature dependence of the exchange current densities" as well as the charge transfer coefficient. The electrical conductivity of bulk material was found to decrease with aluminum content. Formation of the materials into thin porous films further decreased the conductivity after correcting for porosity. Aluminum substitution. substantially decreased the performance through influence of the pre-exponential factor in the Butler-volmer formulation. Neither the activation energies nor the charge transfer coefficient for these materials varied significantly. Aluminum does not adversely influence the basic mechanism of oxygen reduction. It may occupy and block electrochemically active sites on the electrode surface, but it does not appear to decrease the intrinsic activity of available surface sites. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Mat Synth & Modificat Grp, Richland, WA 99352 USA. RP Rieke, PC (reprint author), Pacific NW Natl Lab, Mat Synth & Modificat Grp, K2-44,POB 999, Richland, WA 99352 USA. RI Hardy, John/E-1938-2016 OI Hardy, John/0000-0002-1699-3196 NR 21 TC 21 Z9 22 U1 2 U2 17 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 FEB PY 2003 VL 158 IS 1-2 BP 1 EP 9 AR PII S0167-2738(02)00174-1 DI 10.1016/S0167-2738(02)00174-1 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 654QF UT WOS:000181507000001 ER PT J AU Edman, L Doeff, MM AF Edman, L Doeff, MM TI Thermal analysis of a solid polymer electrolyte and a subsequent electrochemical investigation of a lithium polymer battery SO SOLID STATE IONICS LA English DT Article DE polymer electrolyte; lithium polymer battery; ambient temperature application; thermal properties; cell cycling; differential scanning calorimetry ID TRANSPORT-PROPERTIES; POLY(ETHYLENE OXIDE); IONIC-CONDUCTIVITY; SALT COMPLEXES; PEO-LITFSI; LICF3SO3; CELLS; FILM AB A notable slow recrystallization process following heating above the liquidus line for P(EO),,LiTFSI electrolytes with n values ranging from 5 to 12 is shown to be correlated to a slow nucleation process as concluded from extensive differential scanning calorimetry (DSC) measurements. This concentration anomaly motivated the assembly of a room temperature Li/ P(EO)(8)LiTFSI/LixMnO2 cell, containing a preheated amorphous electrolyte, which initially delivered a cathode capacity of 27 mA h/g at a current density of 0.1 mA/cm(2) and 60 mA h/g at 0.05 mA/cm(2) as compared to typical discharge capacities of 95 - 120 mA h/g for similar polymer systems at 85 degreesC and liquid systems at room temperature. The delivered capacity decreased during cell cycling and reached a limiting value of 10 mA h/g after cycle 15. Li/P(EO)(n)LiTFSl/LixMnO2 cells (n = 6, 8, 20) were also cycled extensively at 85 degreesC, and an analysis of the results indicates that the solid electrolyte interfacial (SEI) resistance, formed between the lithium negative electrode and the electrolyte, remains constant during cycling (R-SEI = 37 x 10(-3) Omega m(2)) and is of the same magnitude as the bulk electrolyte resistance. Furthermore, it is shown that severe concentration gradients develop over the electrolytes during cell operation, and that the marked diminishing cathode capacity for the n = 8 cell at 20 degreesC, and also for the n = 20 cell at 85 degreesC, with increasing current density, appears to be related to a limiting current situation. Losses in energy and power densities at steady state conditions for n = 6 and n = 8 cells at 85 degreesC appear mainly related to the development of a concentration overpotential, which lowers the working potential curve and causes the cutoff potential to be reached sooner. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Umea Univ, Dept Expt Phys, SE-90187 Umea, Sweden. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Edman, L (reprint author), Umea Univ, Dept Expt Phys, SE-90187 Umea, Sweden. OI Doeff, Marca/0000-0002-2148-8047 NR 37 TC 17 Z9 18 U1 1 U2 27 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 FEB PY 2003 VL 158 IS 1-2 BP 177 EP 186 AR PII S0167-2738(02)00716-6 DI 10.1016/S0167-2738(02)00716-6 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 654QF UT WOS:000181507000018 ER PT J AU Shenoy, G AF Shenoy, G TI Basic characteristics of synchrotron radiation SO STRUCTURAL CHEMISTRY LA English DT Article DE synchrotron radiation sources; wigglers; undulators; high brightness; X-ray optics ID HARD X-RAYS; ADVANCED PHOTON SOURCE; INSERTION DEVICES; MULTIPOLE WIGGLER; CRYSTAL OPTICS; ZONE PLATES; MONOCHROMATOR; RESOLUTION; SCATTERING; DYNAMICS AB Many advances have been made in chemical structure research over the past three decades using synchrotron radiation. Synchrotron radiation has a number of unique properties. They include high brightness, high collimation, broad energy spectrum, variable polarization, coherent power, and sub-nanosecond pulse width. The third-generation storage rings with wiggler and undulator sources and lower electron beam dimensions are delivering over 10(12) times higher brightness than laboratory-based sources. The future of synchrotron sources looks very promising with the development of energy recovery linac sources and free-electron laser sources. These will permit dynamic studies of chemical structure with subpico second time resolution. Commensurate with the development of X-ray sources, major progress has occurred in optical schemes to meet the challenging needs of chemical structure research. High-resolution monochromatization and submicron focusing of X rays present new avenues for the future. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Shenoy, G (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 48 TC 17 Z9 18 U1 1 U2 8 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1040-0400 J9 STRUCT CHEM JI Struct. Chem. PD FEB PY 2003 VL 14 IS 1 BP 3 EP 14 DI 10.1023/A:1021656723964 PG 12 WC Chemistry, Multidisciplinary; Chemistry, Physical; Crystallography SC Chemistry; Crystallography GA 626GQ UT WOS:000179863800002 ER PT J AU Fischer, P Eimuller, T Schutz, G Denbeaux, G AF Fischer, P Eimuller, T Schutz, G Denbeaux, G TI Imaging magnetic domain structures with soft X-ray microscopy SO STRUCTURAL CHEMISTRY LA English DT Article DE X-ray magnetic circular dichroism; soft X-ray microscopy; magnetic domain structure; circular polarized synchrotron radiation; Fresnel zone plates ID SCANNING-TUNNELING-MICROSCOPY; CIRCULAR-DICHROISM; ELECTRON AB The current achievements in magnetic transmission soft X-ray microscopy will be reviewed. The magnetic contrast is given by X-ray magnetic circular dichroism (X-MCD), i.e., the dependence of the absorption coefficient of circularly polarized X rays on the projection of the magnetization in a ferromagnetic system onto the photon propagation direction. X-MCD contrast can reach, e.g., at L-2,L-3 edges in transition metals, large values up to 50%. Combined with a soft X-ray microscope where Fresnel zone plates acting as optical elements provide a lateral resolution down at 25 nm, it allows for imaging magnetic microstructures. Specific features of this photon-based technique are the recording of images in varying external magnetic fields, an inherent chemical specificity, a high sensitivity to thin magnetic layers, due to the large contrast, and the possibility to distinguish between in-plane and out-of plane contributions. In this report, recent results obtained with the XM-1 microscope at the ALS (Berkeley/CA) demonstrate the broad applicability of this novel experimental technique to both fundamental and technological relevant issues in nanomagnetism. The future potential will be briefly outlined. C1 Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr X Ray Opt, Berkeley, CA 94720 USA. RP Fischer, P (reprint author), Max Planck Inst Met Res, Heisenbergstr 1, D-70569 Stuttgart, Germany. RI Fischer, Peter/A-3020-2010 OI Fischer, Peter/0000-0002-9824-9343 NR 31 TC 4 Z9 4 U1 0 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1040-0400 J9 STRUCT CHEM JI Struct. Chem. PD FEB PY 2003 VL 14 IS 1 BP 39 EP 47 DI 10.1023/A:1021612908943 PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Crystallography SC Chemistry; Crystallography GA 626GQ UT WOS:000179863800005 ER PT J AU Pavarini, E Baek, SH Suh, BJ Borsa, F Bud'ko, SL Canfield, PC AF Pavarini, E Baek, SH Suh, BJ Borsa, F Bud'ko, SL Canfield, PC TI NMR relaxation rates and Knight shifts in MgB2 and AlB2: theory versus experiments SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Magnesium Diboride and Related Materials CY JUN 17-19, 2002 CL GENOA, ITALY ID SUPERCONDUCTIVITY AB We have performed B-11 NMR measurements in B-11 enriched MgB2 powder sample in the normal phase. The Knight shift was accurately determined by using the magic angle spinning technique. Results for B-11 and Al-27 Knight shifts (K) and relaxation rates (1/T-1) are also reported for AlB2. The data show a dramatic decrease of both K and 1/T-1 for B-11 in AlB2 with respect to MgB2. We compare experimental results with ab initio calculated NMR relaxation rates and Knight shifts. The experimental values for 1/T-1 and K are in most cases in good agreement with the theoretical results. We show that the decrease of K and 1/T-1 for B-11 is consistent with a drastic drop of the density of states at the boron site in AlB2 with respect to MgB2. C1 Univ Pavia, INFM, I-27100 Pavia, Italy. Univ Pavia, Dipartimento Fis A Volta, I-27100 Pavia, Italy. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Catholic Univ Korea, Dept Phys, Puchon 420743, South Korea. RP Pavarini, E (reprint author), Univ Pavia, INFM, Via Bassi 6, I-27100 Pavia, Italy. EM pavarini@pv.infn.it RI Pavarini, Eva/F-3156-2011; Canfield, Paul/H-2698-2014; Baek, Seung-Ho/F-4733-2011 OI Pavarini, Eva/0000-0003-0860-8558; Baek, Seung-Ho/0000-0002-0059-8255 NR 27 TC 6 Z9 6 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD FEB PY 2003 VL 16 IS 2 BP 147 EP 151 AR PII S0953-2048(03)56897-X DI 10.1088/0953-2048/16/2/303 PG 5 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 651RT UT WOS:000181335600004 ER PT J AU Iavarone, M Karapetrov, G Koshelev, A Kwok, WK Hinks, D Crabtree, GW Kang, WN Chi, EM Kim, HJ Lee, SI AF Iavarone, M Karapetrov, G Koshelev, A Kwok, WK Hinks, D Crabtree, GW Kang, WN Chi, EM Kim, HJ Lee, SI TI MgB2: directional tunnelling two-band superconductivity SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Magnesium Diboride and Related Materials CY JUN 17-19, 2002 CL GENOA, ITALY ID 2-BAND SUPERCONDUCTIVITY; TUNNELING SPECTROSCOPY; MAGNESIUM DIBORIDE; POINT-CONTACT; ENERGY-GAP; ART.; DENSITY AB We have studied the anisotropic superconductor MgB2 using a combination of scanning electron microscopy and scanning tunnelling spectroscopy. Tunnelling spectroscopy performed on thin films and pellets reveals two distinct energy gaps at Delta(1) = 2.3 meV and Delta(2) = 7.1 meV. On different crystallites within the polycrystalline sample different spectral weights of the partial densities of states (PDOS) were observed. They reflect different tunnelling directions with respect to the crystallographic orientation of the grain in a multiband system. Indeed when tunnelling in the c-axis films only one superconducting gap is observed, which is associated with the 3D band in this system. Temperature evolution of the tunnelling spectra reveals that both gaps close simultaneously near the bulk critical temperature, Our experimental findings are consistent with the two-band superconductivity scenario in the presence of strong pair interaction between the two bands [1]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Pohang Univ Sci & Technol, NCRICS, Pohang 790784, South Korea. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. RP Iavarone, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Karapetrov, Goran/C-2840-2008; Iavarone, Maria/C-3628-2008 OI Karapetrov, Goran/0000-0003-1113-0137; NR 24 TC 7 Z9 7 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD FEB PY 2003 VL 16 IS 2 BP 156 EP 161 AR PII S0953-2048(03)54456-6 DI 10.1088/0953-2048/16/2/305 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 651RT UT WOS:000181335600006 ER PT J AU Lyard, L Samuely, P Szabo, P Marcenat, C Klein, T Kim, KHP Jung, CU Lee, HS Kang, B Choi, S Lee, SI Paulius, L Marcus, J Blanchard, S Jansen, AGM Welp, U Karapetrov, G Kwok, WK AF Lyard, L Samuely, P Szabo, P Marcenat, C Klein, T Kim, KHP Jung, CU Lee, HS Kang, B Choi, S Lee, SI Paulius, L Marcus, J Blanchard, S Jansen, AGM Welp, U Karapetrov, G Kwok, WK TI Upper critical magnetic fields in single crystal MgB2 SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Magnesium Diboride and Related Materials CY JUN 17-19, 2002 CL GENOA, ITALY ID SUPERCONDUCTING PROPERTIES; STATE; MAGNETOTRANSPORT; HEAT AB The upper critical field H-c2 for the fields perpendicular and parallel to Mg and B planes of the magnesium diboride is presented in the temperature range from 5.4 K up to T-c as obtained by comparison of high-field magnetotransport, ac-susceptibility and specific heat measurements. The onset of the finite resistivity yields H-c2, while the end of the resistive transition to the normal state is due to surface effects. H-c2 perpendicular to the planes reveals a conventional temperature dependence with mu(0)H(c2perpendicular toab)(0) = 3.5 T but the parallel critical field with mu(0)H(c2parallel toab)(0) = 17 T has a positive curvature at temperatures above 20 K. Consequently, the anisotropy factor Gamma = H-c2parallel toab/H-c2perpendicular toab is temperature dependent with Gamma equal to 4.8 at low temperatures and about 2 near T-c. The angular dependence of the upper critical field of an elliptic form is obtained at several temperatures. C1 CNRS, Etud Proprietes Elect Solides Lab, F-38042 Grenoble 9, France. Commissariat Energie Atom Grenoble, Dept Rech Fondamentale Mat Condensee, SPSMS, F-38054 Grenoble 9, France. Univ Grenoble 1, F-38041 Grenoble 9, France. Slovak Acad Sci, Inst Expt Phys, SK-04353 Kosice, Slovakia. Pohang Univ Sci & Technol, NVCRICS, Pohang 790784, South Korea. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. Max Planck Inst Festkorperforsch, Grenoble High Magnet Field Lab, F-38042 Grenoble 9, France. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Lyard, L (reprint author), CNRS, Etud Proprietes Elect Solides Lab, BP 166, F-38042 Grenoble 9, France. RI Karapetrov, Goran/C-2840-2008 OI Karapetrov, Goran/0000-0003-1113-0137 NR 38 TC 12 Z9 12 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD FEB PY 2003 VL 16 IS 2 BP 193 EP 198 AR PII S0953-2048(03)55318-0 DI 10.1088/0953-2048/16/2/312 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 651RT UT WOS:000181335600013 ER PT J AU Karpinski, J Angst, M Jun, J Kazakov, SM Puzniak, R Wisniewski, A Roos, J Keller, H Perucchi, A Degiorgi, L Eskildsen, MR Bordet, P Vinnikov, L Mironov, A AF Karpinski, J Angst, M Jun, J Kazakov, SM Puzniak, R Wisniewski, A Roos, J Keller, H Perucchi, A Degiorgi, L Eskildsen, MR Bordet, P Vinnikov, L Mironov, A TI MgB2 single crystals: high pressure growth and physical properties SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Magnesium Diboride and Related Materials CY JUN 17-19, 2002 CL GENOA, ITALY ID SUPERCONDUCTING PROPERTIES; FIELD AB Single crystals of MgB2 with a size up to 1.5 x 0.9 x 0.2 mm(3) have been grown with a high pressure cubic anvil technique. The crystal growth process is very peculiar and involves an intermediate nitride, namely MgNB9. Single crystals of BN and MgB2 grow simultaneously by a peritectic decomposition of MgNB9. Magnetic measurements with SQUID magnetometry in fields of 1-5 Oe show, sharp transitions to the superconducting state at 37-38.6 K with a width of similar to0.5 K. The high quality of the crystals allowed the accurate determination of magnetic, transport (electric and heat) and optical properties as well as scanning tunnelling spectroscopy (STS) and decoration studies. Investigations of crystals with torque magnetometry show that H-c2(parallel toc) for high quality crystals is very low (24 kOe at 15 K) and saturates with decreasing temperature, while H-c2(parallel toab) increases up to 140 kOe at 15 K. The upper critical field anisotropy gamma = H-c2(parallel toab)/H-c2(parallel toc) was found to be temperature dependent (decreasing from gamma congruent to 6 at 15 K to 2.8 at 35 K). The effective anisotropy gamma(eff), as calculated from reversible torque data near T, is field dependent (increasing roughly linearly from gamma(eff) congruent to 2 in zero field to 3.7 in 10 kOe). The temperature and field dependence of the anisotropy can be related to the double gap structure of MgB2 with a large two-dimensional gap and small three-dimensional gap, the latter of which is rapidly suppressed in a magnetic field. Torque magnetometry investigations also show a pronounced peak effect, which indicates an order-disorder phase transition of vortex matter. Decoration experiments and STS visualize a hexagonal vortex lattice. STS spectra in zero field evidence two gaps 3 meV and 6 meV with a weight depending on the tunnelling direction. Magneto-optic investigations in the far-infrared region with Hparallel toc show a clear signature of the smaller of the two superconducting gaps, completely disappearing only in fields higher than H-c2(parallel toc). C1 Swiss Fed Inst Technol, Solid State Phys Lab, Zurich, Switzerland. Polish Acad Sci, Inst Phys, Warsaw, Poland. Univ Zurich, Inst Phys, Zurich, Switzerland. Univ Geneva, DPMC, Geneva, Switzerland. CNRS, Lab Cristallog, Grenoble, France. US DOE, Ames Lab, Ames, IA 50011 USA. Moscow MV Lomonosov State Univ, Dept Chem, Moscow, Russia. RP Karpinski, J (reprint author), Swiss Fed Inst Technol, Solid State Phys Lab, Zurich, Switzerland. EM karpinski@solid.phys.ethz.ch RI Eskildsen, Morten/E-7779-2011; Angst, Manuel/I-4380-2012; Kazakov, Sergey/A-4139-2014; Puzniak, Roman/N-1643-2013; Wisniewski, Andrzej/A-1781-2017 OI Angst, Manuel/0000-0001-8892-7019; Kazakov, Sergey/0000-0002-0553-7881; Puzniak, Roman/0000-0001-5636-5541; NR 35 TC 66 Z9 67 U1 0 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD FEB PY 2003 VL 16 IS 2 BP 221 EP 230 AR PII S0953-2048(03)54487-6 DI 10.1088/0953-2048/16/2/317 PG 10 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 651RT UT WOS:000181335600018 ER PT J AU Andreone, A Di Gennaro, E Lamura, G Salluzzo, M Purnell, A Cohen, LF Hao, L Gallop, J Cantoni, C Paranthaman, M AF Andreone, A Di Gennaro, E Lamura, G Salluzzo, M Purnell, A Cohen, LF Hao, L Gallop, J Cantoni, C Paranthaman, M TI A study on the nonlinear microwave electrodynamic response of e-beam evaporated MgB2 superconducting thin films SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Magnesium Diboride and Related Materials CY JUN 17-19, 2002 CL GENOA, ITALY ID SURFACE-RESISTANCE; ANISOTROPY AB We present a study on the temperature and field dependence of the microwave surface impedance Z(s) in thin films of the superconducting MgB2 compound. Samples were prepared by e-beam evaporation of boron on r-plane sapphire followed by an ex situ annealing in Mg vapour. Critical temperature values range between 26 and 38 K. Surface impedance measurements (Z(s) = R-s + iX(s)) were performed from 2 K close to T-c in the microwave region up to 20 GHz via parallel plate or dielectrically loaded resonators in 'symmetric' (two MgB2 films) and asymmetric (an MgB2 film and a commercial YBCO control film) configurations. At high microwave power, frequency domain measurements show a characteristic signature associated with weak links and this appears to be the limiting factor governing the performance of these films. C1 Univ Naples Federico II, INFM, I-80125 Naples, Italy. Univ Naples Federico II, Dipartimento Sci Fisiche, I-80125 Naples, Italy. Univ London Imperial Coll Sci Technol & Med, London SW7 2BZ, England. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Andreone, A (reprint author), Univ Naples Federico II, INFM, I-80125 Naples, Italy. RI salluzzo, marco/C-5919-2009; Paranthaman, Mariappan/N-3866-2015; Di Gennaro, Emiliano/G-6311-2010; Cantoni, Claudia/G-3031-2013 OI salluzzo, marco/0000-0001-8372-6963; Paranthaman, Mariappan/0000-0003-3009-8531; Di Gennaro, Emiliano/0000-0003-4231-9776; Cantoni, Claudia/0000-0002-9731-2021 NR 20 TC 6 Z9 6 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD FEB PY 2003 VL 16 IS 2 BP 260 EP 263 AR PII S0953-2048(03)54872-2 DI 10.1088/0953-2048/16/2/323 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 651RT UT WOS:000181335600024 ER PT J AU Rocha-Rangel, E Becher, PF Lara-Curzio, E AF Rocha-Rangel, E Becher, PF Lara-Curzio, E TI Influence of carbon on the interfacial contact angle between alumina and liquid aluminum SO SURFACE AND INTERFACE ANALYSIS LA English DT Article DE carbon; interfacial; contact angle; alumina; aluminum ID METAL-MATRIX COMPOSITES; CERAMIC SYSTEMS; SURFACE-TENSION; WETTABILITY; CHEMISTRY; DYNAMICS; SAPPHIRE; SILICON; ALLOYS AB The wetting of alumina by pure liquid aluminum was investigated over the temperature range 900-1300degreesC by the sessile drop method under a dynamic vacuum of 10(-4) -10(-5) Pa. When the substrate is carbon coated, the terminal contact angle is reduced to 40degrees at 1300degreesC for times longer than 4500 s. In the absence of carbon, the final angle is 82degrees for the same conditions. Reactive wetting is suggested by the observation of undercutting of the substrate and ridge formation at the leading edge of the liquid aluminum in all carbon-coated samples. Based on energy considerations, the following is among the thermodynamically favorable reactions: 4Al + 3C --> Al4C3. Possible mechanisms for the observed carbon-enhanced wettability in the system are discussed. Copyright (C) 2003 John Wiley Sons, Ltd. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. UAM A, Dept Mat, Mexico City 02200, DF, Mexico. RP Lara-Curzio, E (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 37 TC 10 Z9 10 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD FEB PY 2003 VL 35 IS 2 BP 151 EP 155 DI 10.1002/sia.1525 PG 5 WC Chemistry, Physical SC Chemistry GA 649MM UT WOS:000181212600006 ER PT J AU Salvadori, MC Melo, LL Cattani, M Monteiro, OR Brown, IG AF Salvadori, MC Melo, LL Cattani, M Monteiro, OR Brown, IG TI Measurement of critical exponents of platinum thin films SO SURFACE REVIEW AND LETTERS LA English DT Article DE platinum thin films; critical exponents ID SCANNING-TUNNELING-MICROSCOPY; CATHODIC-ARC DEPOSITION; DIAMOND FILMS; CORRELATED NOISE; METAL PLASMA; GROWTH; SURFACES AB We have fabricated platinum thin films by metal plasma ion deposition on silicon substrates. The roughness of these films has been measured by a scanning tunneling microscope (STM) and we have determined the growth dynamics critical exponents. C1 Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Salvadori, MC (reprint author), Univ Sao Paulo, Inst Fis, CP 66318, BR-05315970 Sao Paulo, Brazil. RI Cattani, Mauro/N-9749-2013; Salvadori, Maria Cecilia/A-9379-2013 NR 25 TC 19 Z9 19 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD FEB PY 2003 VL 10 IS 1 BP 1 EP 5 DI 10.1142/S0218625X03004561 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 669YC UT WOS:000182377900001 ER PT J AU Lea, AS Hurt, TT El-Azab, A Amonette, JE Baer, DR AF Lea, AS Hurt, TT El-Azab, A Amonette, JE Baer, DR TI Heteroepitaxial growth of a manganese carbonate secondary nano-phase on the (1 0(1)over-bar 4) surface of calcite in solution SO SURFACE SCIENCE LA English DT Article DE epitaxy; solid-liquid interfaces; surface stress; atomic force microscopy ID RAY STANDING-WAVE; SCANNING FORCE MICROSCOPY; SOLID-SOLUTION FORMATION; MN2+ IMPURITY IONS; GHZ EPR-SPECTRA; CRYSTAL-GROWTH; IN-SITU; DISSOLUTION KINETICS; POLYCRYSTALLINE CALCITE; RADIONUCLIDE SORPTION AB Heteroepitaxy of a manganese carbonate phase with nano-meter dimensions on the (1014) surface of calcite (CaCO3) using an AFM has been observed in solution during dissolution of calcite when the ion activity product of Mn2+ and CO32- nears the solubility limit of MnCO3. Growth rate observations at different Mn concentrations, coupled with X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements, suggest that the resulting phase is Mn0.5Ca0.5CO3. These islands, while growing many microns in length along the [22 1] direction, have a uniform width in the range of 120-240 nm and a uniform height of approximately 2.7 nm, corresponding to nine atomic layers. The islands cease growing when they encounter step edges and have been observed to dissolve when undercut by a growing etch pit. Comparison of the crystal lattices of calcite and Mn0.5Ca0.5CO3 indicates that [221] is the direction of preferred growth. A glued-wetting-layer model with a condition of constant surface chemical potential has been used to model the observed cross section of the heteroepitaxial layer. Although not all the required parameters are accurately known, the model accurately depicts the measured profiles of the islands. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Lea, AS (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS K8-93,POB 999, Richland, WA 99352 USA. RI Baer, Donald/J-6191-2013; OI Baer, Donald/0000-0003-0875-5961; Lea, Alan/0000-0002-4232-1553 NR 71 TC 25 Z9 25 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 2003 VL 524 IS 1-3 BP 63 EP 77 AR PII S0039-6028(02)02479-2 DI 10.1016/S0039-6028(02)02479-2 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 644QB UT WOS:000180928900011 ER PT J AU Adib, K Mullins, DR Totir, G Camillone, N Fitts, JP Rim, KT Flynn, GW Osgood, RM AF Adib, K Mullins, DR Totir, G Camillone, N Fitts, JP Rim, KT Flynn, GW Osgood, RM TI Dissociative adsorption of CCl4 on the Fe3O4(111)-(2 x 2) selvedge of alpha-Fe2O3(0001) SO SURFACE SCIENCE LA English DT Article DE molecule-solid reactions; synchrotron radiation photoelectron spectroscopy; thermal desorption spectroscopy; surface chemical reaction; iron oxide; Halides ID SCANNING-TUNNELING-MICROSCOPY; IRON-OXIDE SURFACES; RAY PHOTOELECTRON; AQUEOUS CR(VI); PHOTOEMISSION; FILMS; TERMINATION; WATER; PHOTODISSOCIATION; FE3O4(001) AB The surface reactions of CCl4 with the Fe3O4(111)-(2 x 2) selvedge of naturally occurring alpha-Fe2O3(0001) singlecrystals have been investigated using synchrotron X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD). CCl4 was found to dissociate on the Fe3O4 surface at 100 K producing chemisorbed Cl and adsorbed CCl2. TPD shows that the large majority of the dissociatively adsorbed CCl2 fragments extract lattice oxygen and desorb as phosgene at >275 K. However, the XPS spectra show no evidence for the formation of surface-bound phosgene, at 100 K, indicating that its formation involves two steps. The first step, dissociation, is spontaneous at 100 K, whereas the second, oxygen atom abstraction to form phosgene, requires thermal excitation. Cl chemisorption yielded two separate species, the mono- and dichloride terminations of surface iron sites. The identification of these two surface terminations is based on the coverage dependence and the surface temperature history of their Cl 2p(3/2) peak intensity. For example, heating to >450 K allows the monochloride to transform into iron dichloride, indicating Cl adatom mobility at these temperatures. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Dept Appl Phys & Appl Math, Mat Sci Program, New York, NY 10027 USA. Columbia Univ, Ctr Integrated Sci & Engn, Environm Mol Sci Inst, New York, NY 10027 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Osgood, RM (reprint author), Columbia Univ, Ctr Integrated Sci & Engn, Environm Mol Sci Inst, 530 W 120th St, New York, NY 10027 USA. RI Fitts, Jeffrey/J-3633-2012 NR 49 TC 19 Z9 21 U1 2 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 2003 VL 524 IS 1-3 BP 113 EP 128 AR PII S0039-6028(02)02485-8 DI 10.1016/S0039-6028(02)02485-8 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 644QB UT WOS:000180928900015 ER PT J AU Brako, EE Wilson, AK Jonah, MM Blum, CA Cerny, EA Williams, KL Bhattacharyya, MH AF Brako, EE Wilson, AK Jonah, MM Blum, CA Cerny, EA Williams, KL Bhattacharyya, MH TI Cadmium pathways during gestation and lactation in control versus metallothoinein 1,2-knockout mice SO TOXICOLOGICAL SCIENCES LA English DT Article DE metallothionein; cadmium; pregnancy; gestation; lactation; mice ID GASTROINTESTINAL ABSORPTION; TISSUE DISTRIBUTION; METALLOTHIONEIN-I; INTESTINAL-ABSORPTION; NULL; RETENTION; EXPOSURE; MOUSE; SENSITIVITY; PREGNANCY AB Effects of metallothionein (MT) on cadmium absorption and transfer pathways during gestation and lactation in mice were investigated. Female 129/SvJ metallothionein-knockout (MT1,2KO) and metallothionein-normal (MTN) mice received drinking water containing trace amounts of (CdCl2)-Cd-109 (0.15 ng Cd/ml; 0.074 muCi Cd-109/ml). Cd-109 and MT in maternal, fetal, and pup tissues were measured on gestation days 7, 14, and 17 and lactation day 11. In dams, MT influenced both the amount of Cd-109 transferred from intestine into body (two- to three-fold higher in MT1,2KO than MTN dams) and tissue-specific Cd-109 distribution (higher liver/kidney ratio in MT1,2KO dams). Placental Cd-109 concentrations in MT1,2KO dams were three- and seven-fold higher on gestation days 14 and 17, respectively, than in MTN dams. Fetal Cd-109 levels were low in both mouse types, but at least 10-fold lower in MTN fetuses. MT had no effect on the amount of Cd-109 transferred to pups via milk; furthermore, 85-90% of total pup Cd-109 was recovered in gastrointestinal tracts of both types, despite high duodenal MT only in MTN pups. A relatively large percentage of milk-derived intestinal Cd-109 was transferred to other pup tissues in both MT1,2KO and MTN pups (14 and 10%, respectively). These results demonstrate that specific sequestration of cadmium by both maternal and neonatal intestinal tract does not require MT. Although MT decreased oral cadmium transfer from intestine to body tissues at low cadmium exposure levels, MT did not play a major role in restricting transfer of cadmium from dam to fetus via placenta and to neonate via milk. C1 Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. Winona State Univ, Dept Biol, Winona, MN 55987 USA. Benedictine Univ, Dept Biol Sci, Lisle, IL 60532 USA. Dominican Univ, Dept Nat Sci, River Forest, IL 60305 USA. RP Bhattacharyya, MH (reprint author), Argonne Natl Lab, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 38 TC 17 Z9 19 U1 0 U2 5 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1096-6080 J9 TOXICOL SCI JI Toxicol. Sci. PD FEB PY 2003 VL 71 IS 2 BP 154 EP 163 DI 10.1093/toxsci/71.2.154 PG 10 WC Toxicology SC Toxicology GA 642XT UT WOS:000180832200005 PM 12563101 ER PT J AU Poet, TS Soelberg, JJ Weitz, KK Mast, TJ Miller, RA Thrall, BD Corley, RA AF Poet, TS Soelberg, JJ Weitz, KK Mast, TJ Miller, RA Thrall, BD Corley, RA TI Mode of action and pharmacokinetic studies of 2-butoxyethanol in the mouse with an emphasis on forestomach dosimetry SO TOXICOLOGICAL SCIENCES LA English DT Article DE glycol ethers; 2-butoxyethanol; butoxyacetic acid; forestomach, dosimetry ID PHYSIOLOGICALLY-BASED PHARMACOKINETICS; BUTOXYACETIC ACID; MAJOR METABOLITE; 2-BUTOXYACETIC ACID; OXIDATIVE STRESS; B6C3F1 MICE; F344 RATS; HUMANS; DEFORMABILITY; ABSORPTION AB Chronic inhalation studies with 2-butoxyethanol (BE) conducted by the National Toxicology Program identified the forestomach and liver of B6C3F1 mice as target organs for tumorigenicity (NTP, 2000). Previous studies have shown that the liver tumors likely resulted from chronic hemolysis-induced oxidative stress. For the forestomach lesions seen in mice, chronic contact irritation (cytotoxicity) and regenerative hyperplasia are hypothesized to result in forestomach tumor development. To test this hypothesis, several experiments were conducted to address the sensitivity of the mouse forestomach to BE administered by various routes. Oral administration of undiluted BE was shown to cause irritation and a compensatory proliferative response in the mouse forestomach, confirming that direct contact between the forestomach and BE, which can occur via grooming of BE condensed on the fur during inhalation exposures, can cause irritation. However, only small amounts of BE (<10 mg/kg) were detected on the fur of mice at the end of 6-h, whole-body or nose-only inhalation exposures to the highest concentration used in the NTP chronic inhalation studies (250 ppm). Furthermore, no significant differences were detected in the end-exposure blood concentrations of BE and butoxyacetic acid (BAA) between these types of exposures. In addition, parenteral administration of BE (ip and sc injection) also resulted in forestomach lesions, indicating that there may be sources other than grooming for BE- or BAA-induced forestomach irritation. In the pharmacokinetic study, BE and, to a lesser extent, BAA was eliminated more slowly from the forestomach tissue of mice than from blood or other tissues, following either oral gavage or ip injection. The forestomach was the only tissue with detectable levels of BE at 24 h. BE and BAA were both excreted in the saliva and were present in stomach contents for a prolonged period of time following these routes of exposure, which may further contribute to forestomach tissue dosimetry. Thus, there appear to be multiple mechanisms behind the increased levels of BE and BAA in the forestomach tissue of mice, which together can contribute to a prolonged contact irritation, compensatory hyperplasia, and tumorigenicity in mice. The relevance of these effects in humans, who lack a forestomach, is questionable. C1 Battelle Mem Inst, Pacific NW Div, Chem Dosimetry, Richland, WA 99352 USA. Battelle Mem Inst, Columbus Operat, Richland, WA 99352 USA. RP Poet, TS (reprint author), Battelle Mem Inst, Pacific NW Div, Chem Dosimetry, POB 999,MSIN P7-59, Richland, WA 99352 USA. NR 26 TC 15 Z9 17 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1096-6080 J9 TOXICOL SCI JI Toxicol. Sci. PD FEB PY 2003 VL 71 IS 2 BP 176 EP 189 DI 10.1093/toxsci/71.2.176 PG 14 WC Toxicology SC Toxicology GA 642XT UT WOS:000180832200007 PM 12563103 ER PT J AU Frome, EL Newman, LS Cragle, DL Colyer, SP Wambach, PF AF Frome, EL Newman, LS Cragle, DL Colyer, SP Wambach, PF TI Identification of an abnormal beryllium lymphocyte proliferation test SO TOXICOLOGY LA English DT Article DE beryllium; lymphocyte proliferation test; least absolute values; statistical methods; electronic notebook ID OPERATING CHARACTERISTIC CURVES; DISEASE; SENSITIVITY; REGRESSION AB The potential hazards from exposure to beryllium or beryllium compounds in the workplace were first reported in the 1930s. The tritiated thymidine beryllium lymphocyte proliferation test (BeLPT) is an in vitro blood test that is widely used to screen beryllium exposed workers in the nuclear industry for sensitivity to beryllium. The clinical significance of the BeLPT was described and a standard protocol was developed in the late 1980s. Cell proliferation is measured by the incorporation of tritiated thymidine into dividing cells on two culture dates and using three concentrations of beryllium sulfate. Results are expressed as a 'stimulation index' (SI) which is the ratio of the amount of tritiated thymidine (measured by beta counts) in the simulated cells divided by the counts for the unstimulated cells on the same culture day. Several statistical methods for use in the routine analysis of the BeLPT were proposed in the early 1990s. The least absolute values (LAV) method was recommended for routine analysis of the BeLPT. This report further evaluates the LAV method using new data, and proposes a new method for identification of an abnormal or borderline test. This new statistical-biological positive (SBP) method reflects the clinical judgment that: (i) at least two SIs show a 'positive' response to beryllium; and (ii) that the maximum of the six SIs must exceed a cut-point that is determined from a reference data set of normal individuals whose blood has been tested by the same method in the same serum. The new data is from the Y-12 National Security Complex in Oak Ridge (Y-12) and consists of 1080 workers and 33 nonexposed control BeLPTs (all tested in the same serum). Graphical results are presented to explain the statistical method, and the new SBP method is applied to the Y-12 group. The true positive rate and specificity of the new method were estimated to be 86% and 97%, respectively. An electronic notebook that is accessible via the Internet was used in this work and contains background information and details not included in the paper. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37830 USA. Natl Jewish Med & Res Ctr, Denver, CO USA. Oak Ridge Inst Sci & Educ, Ctr Epidemiol Res, Oak Ridge, TN USA. US DOE, Germantown, MD USA. RP Frome, EL (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37830 USA. NR 28 TC 21 Z9 21 U1 2 U2 2 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0300-483X J9 TOXICOLOGY JI Toxicology PD FEB 1 PY 2003 VL 183 IS 1-3 BP 39 EP 56 AR PII S0300-483X(02)00439-0 DI 10.1016/S0300-483X(02)00439-0 PG 18 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 642HX UT WOS:000180799100004 PM 12504341 ER PT J AU Verruijt, A Sagaseta, C Strack, OE AF Verruijt, A Sagaseta, C Strack, OE TI Predictions of ground deformations in shallow tunnels in clay - Wei-I. Chou; Antonio Bobet, Tunnelling and Underground Space Technology, vol. 17, pp 3-19 SO TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY LA English DT Editorial Material ID ELASTIC HALF-PLANE C1 Delft Univ Technol, Dept Civil Engn, NL-2628 CN Delft, Netherlands. Univ Cantabria, E-39005 Santander, Spain. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Verruijt, A (reprint author), Delft Univ Technol, Dept Civil Engn, Stevinweg 1, NL-2628 CN Delft, Netherlands. EM a.verruijt@planet.nl NR 8 TC 0 Z9 0 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0886-7798 J9 TUNN UNDERGR SP TECH JI Tunn. Undergr. Space Technol. PD FEB PY 2003 VL 18 IS 1 BP 93 EP 94 AR PII S0886-7798(02)00104-9 DI 10.1016/S0886-7798(02)00104-9 PG 2 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA 658QF UT WOS:000181731100009 ER PT J AU Eliassi-Rad, T Shavlik, J AF Eliassi-Rad, T Shavlik, J TI A system for building intelligent agents that learn to retrieve and extract information SO USER MODELING AND USER-ADAPTED INTERACTION LA English DT Article DE information extraction; information retrieval; instructable and adaptive software agents; machine learning; neural networks; Web mining ID AUTOMATIC TEXT RETRIEVAL; KNOWLEDGE; NETWORKS AB We present a system for rapidly and easily building instructable and self-adaptive software agents that retrieve and extract information. Our Wisconsin Adaptive Web Assistant ( WAWA) constructs intelligent agents by accepting user preferences in the form of instructions. These user-provided instructions are compiled into neural networks that are responsible for the adaptive capabilities of an intelligent agent. The agent's neural networks are modified via user-provided and system-constructed training examples. Users can create training examples by rating Web pages (or documents), but more importantly WAWA's agents uses techniques from reinforcement learning to internally create their own examples. Users can also provide additional instruction throughout the life of an agent. Our experimental evaluations on a 'home-page finder' agent and a 'seminar-announcement extractor' agent illustrate the value of using instructable and adaptive agents for retrieving and extracting information. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Univ Wisconsin, Dept Comp Sci, Madison, WI 53706 USA. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Box 808,L-560, Livermore, CA 94551 USA. EM eliassi@llnl.gov; shavlik@cs.wisc.edu NR 47 TC 3 Z9 3 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0924-1868 EI 1573-1391 J9 USER MODEL USER-ADAP JI User Model. User-Adapt. Interact. PD FEB-MAY PY 2003 VL 13 IS 1 BP 35 EP 88 DI 10.1023/A:1024009718142 PG 54 WC Computer Science, Cybernetics SC Computer Science GA 684KE UT WOS:000183204700003 ER PT J AU Constantz, J Tyler, SW Kwicklis, E AF Constantz, Jim Tyler, Scott W. Kwicklis, Edward TI Temperature-Profile Methods for Estimating Percolation Rates in Arid Environments SO VADOSE ZONE JOURNAL LA English DT Review AB Percolation rates are estimated using vertical temperature profiles from sequentially deeper vadose environments, progressing from sediments beneath stream channels, to expansive basin-fill materials, and finally to deep fractured bedrock underlying mountainous terrain. Beneath stream channels, vertical temperature profiles vary over time in response to downward heat transport, which is generally controlled by conductive heat transport during dry periods, or by advective transport during channel infiltration. During periods of stream-channel infiltration, two relatively simple approaches are possible: a heat-pulse technique, or a heat and liquid-water transport simulation code. Focused percolation rates beneath stream channels are examined for perennial, seasonal, and ephemeral channels in central New Mexico, with estimated percolation rates ranging from 100 to 2100 mm d(-1). Deep within basin-fill and underlying mountainous terrain, vertical temperature gradients are dominated by the local geothermal gradient, which creates a profile with decreasing temperatures toward the surface. If simplifying assumptions are employed regarding stratigraphy and vapor fluxes, an analytical solution to the heat transport problem can be used to generate temperature profiles at specified percolation rates for comparison to the observed geothermal gradient. Comparisons to an observed temperature profile in the basin-fill sediments beneath Frenchman Flat, Nevada, yielded water fluxes near zero, with absolute values <10 mm yr(-1). For the deep vadose environment beneath Yucca Mountain, Nevada, the complexities of stratigraphy and vapor movement are incorporated into a more elaborate heat and water transport model to compare simulated and observed temperature profiles for a pair of deep boreholes. Best matches resulted in a percolation rate near zero for one borehole and 11 mm yr(-1) for the second borehole. C1 [Constantz, Jim] US Geol Survey, Menlo Pk, CA 94025 USA. [Tyler, Scott W.] Univ Nevada, Reno, NV 89557 USA. [Kwicklis, Edward] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Constantz, J (reprint author), US Geol Survey, 345 Middlefield Rd, Menlo Pk, CA 94025 USA. EM jconstan@usgs.gov FU National Science Foundation [EAR-9614646] FX The authors would like to thank Jim Bartolino, USGS, for the Rio Grande Data; Amy Lewis, Sangre de Cristo Water, Santa Fe, NM, for surface water data for the Santa Fe River; Amy Stewart, Philip Williams and Associates, San Francisco, CA, for analysis of the Santa Fe River data; and Rich Niswonger, U.C. Davis and USGS, for analysis of the Bear Canyon data. The authors would also like to thank Joe Rousseau, USGS, and Paul "Ty" Ferre, University of Arizona, for thoughtful reviews. Efforts of the second author were funded in part by National Science Foundation Grant EAR-9614646. NR 55 TC 55 Z9 56 U1 1 U2 18 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 1539-1663 J9 VADOSE ZONE J JI Vadose Zone J. PD FEB PY 2003 VL 2 IS 1 BP 12 EP 24 PG 13 WC Environmental Sciences; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA V11UY UT WOS:000207557700002 ER PT J AU Oostrom, M Lenhard, RJ AF Oostrom, M. Lenhard, R. J. TI Carbon Tetrachloride Flow Behavior in Unsaturated Hanford Caliche Material: An Investigation of Residual Nonaqueous Phase Liquids SO VADOSE ZONE JOURNAL LA English DT Article AB At many contaminated sites, nonaqueous phase liquids (NAPLs) persist in the vadose zone for long periods of time. This occurs because the permeability of the NAPL becomes negligible at some saturation and downward movement ceases, resulting in residual NAPL. To obtain data that can be used to study the development of a residual NAPL saturation and to test corresponding models, a detailed transient experiment was conducted in a 170 cm long by 90 cm high by 5.5 cm wide flow cell. Fluid saturation measurements were obtained with a dual-energy gamma radiation system. The experimental conditions reflected those at the Hanford Site in Washington State, where an estimated 363 to 580 m(3) of carbon tetrachloride (CCl(4)) was disposed to the subsurface. A key subsurface feature at the Hanford Site is a sloped Plio-Pleistocene caliche layer, which was reproduced in the experiment as a sloped lens in a medium-grained, uniform, sand matrix. The caliche contains considerable amounts of CaCO(3) and may have fluid wettability properties other than strongly water wet. A total of 800 mL of CCl(4) was injected into the experimental domain at a rate of 0.5 mL min(-1) from a small source area located at the surface. After apparent static conditions were obtained with respect to CCl(4) redistribution, saturation measurements indicated that all of the dense nonaqueous phase liquids (DNAPL) that had initially moved into the caliche remained in this layer. Water was subsequently applied to the surface at a constant rate over the full length of the caliche layer to study CCl(4) displacement as a result of changing water saturations. Water saturation in the caliche layer rose to as high as 0.91 during water infiltration. Results show that 25% of the DNAPL present in the caliche migrated from this layer as a consequence of water infiltration, while 75% remained in the caliche layer. The experimental results could not be reproduced with numerical multifluid flow simulations based on common constitutive theory. This indicates that improvements in constitutive theory may be needed to accurately model air - DNAPL-water flow behavior. C1 [Oostrom, M.] Pacific NW Natl Lab, Environm Technol Div, Richland, WA 99352 USA. [Lenhard, R. J.] Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Oostrom, M (reprint author), Pacific NW Natl Lab, Environm Technol Div, POB 999,MS K9-33, Richland, WA 99352 USA. EM mart.oostrom@pnl.gov FU Idaho National Engineering & Environmental Laboratory (INEEL); U.S. Department of Energy's Richland Operations Office FX Pacific Northwest National Laboratory is operated by the Battelle Memorial Institute for the Department of Energy under Contract DE-AC06-76RLO 1830. The laboratory experiment was supported by the Laboratory Directed Research & Development Program of the Idaho National Engineering & Environmental Laboratory (INEEL) under the Subsurface Science Initiative. The analysis component was supported by the Ground water/Vadose Zone Integration Project funded through the U.S. Department of Energy's Richland Operations Office. NR 31 TC 19 Z9 20 U1 3 U2 4 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 1539-1663 J9 VADOSE ZONE J JI Vadose Zone J. PD FEB PY 2003 VL 2 IS 1 BP 25 EP 33 PG 9 WC Environmental Sciences; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA V11UY UT WOS:000207557700003 ER PT J AU Lin, MC Chung, HM Burke, A AF Lin, MC Chung, HM Burke, A TI An analytical approach for the fast design of high-power waveguide windows SO WAVE MOTION LA English DT Article DE waveguide window; microwave; vacuum; analytical ID VACUUM WINDOW AB An analytical approach is presented to achieve the fast design of high-power waveguide windows. The analytical calculation is compared with the result of numerical simulation via the finite-element code high frequency structure simulator and the experiments of W-band waveguide windows performed at the Stanford Linear Accelerator Center (SLAC), Stanford University, Stanford, CA. The closed form has been carried out to enhance the accuracy and efficiency, and the exact calculation agrees with the experimental results and the numerical simulation very well. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Chiao Tung Univ, Dept Electrophys, Hsinchu 30050, Taiwan. Chung Shan Inst Sci & Technol, High Temp Mat Sect, Mat & Electroopt Res Div, Tao Yuan 325, Taiwan. Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Lin, MC (reprint author), Natl Chiao Tung Univ, Dept Electrophys, Hsinchu 30050, Taiwan. NR 17 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-2125 J9 WAVE MOTION JI Wave Motion PD FEB PY 2003 VL 37 IS 2 BP 183 EP 188 AR PII S0165-2125(02)00073-2 DI 10.1016/S0165-2125(02)00073-2 PG 6 WC Acoustics; Mechanics; Physics, Multidisciplinary SC Acoustics; Mechanics; Physics GA 634UV UT WOS:000180360700006 ER PT J AU Nawrocki, JG DuPont, JN Robino, CV Puskar, JD Marder, AR AF Nawrocki, JG DuPont, JN Robino, CV Puskar, JD Marder, AR TI The mechanism of stress-relief cracking in a ferritic alloy steel SO WELDING JOURNAL LA English DT Article DE stress-relief cracking; carbide precipitation; coarse-grained HAZ; heat-affected zone; ferritic alloy steel; high temperature ID STRAIN-AGE CRACKING; EMBRITTLEMENT AB Stress-relief cracking is a major cause of weld failures in creep-resistant, precipitation-strengthened materials such as ferritic alloy steels, stainless steels, and Ni-based superalloys. Stress-relief cracking occurs primarily in the coarse-grained heat-affected zone of weldments. Although the general causes of stress-relief cracking are known, the underlying mechanisms are very much a topic of debate. The mechanism of stress-relief cracking in the coarse-grained heat-affected zone (CGHAZ) of a new ferritic alloy steel (HCM2S) was investigated through stress-relaxation testing and detailed microstructural characterization. The CGHAZ simulation and stress-relaxation testing was performed using Gleeble techniques. The time to failure exhibited C-curve behavior as a function of temperature. A balance of intergranular and intragranular carbide precipitation controlled the stress-relief cracking susceptibility. Cracking initiated at prior austenite grain boundaries by cavity nucleation on incoherent, Fe-rich M3C carbides. The grain interiors were resistant to plastic deformation due to precipitation strengthening by small (5-40 nm) alloy carbides. Elemental segregation played no detectable role in the stress-relief cracking failures. Much of the microstructural characterization was performed using a VG603 FEG STEM having a probe size of about 1.5 mn. The small probe size allowed nano-sized precipitates to be individually analyzed by using EDS and elemental EDS traces taken across prior austenite grain boundaries. In addition, SE STEM imaging with the VG603 FEG STEM was able to resolve small precipitates that were previously unobservable using conventional TEM and STEM techniques. The results of this study form a basis for heat treatment and welding process variables for HCM2S to avoid stress-relief cracking. In addition, these procedures and analytical results can be applied to other materials to avoid microstructures that are susceptible to stress-relief cracking. C1 Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. Sandia Natl Labs, Joining & Coating Dept, Albuquerque, NM 87185 USA. RP Nawrocki, JG (reprint author), Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. NR 29 TC 25 Z9 25 U1 1 U2 10 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD FEB PY 2003 VL 82 IS 2 BP 25S EP 35S PG 11 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 746VH UT WOS:000186768000012 ER PT J AU Vitek, JM David, SA Hinman, CR AF Vitek, JM David, SA Hinman, CR TI Improved ferrite number prediction model that accounts for cooling rate effects - Part 2: Model results SO WELDING JOURNAL LA English DT Article DE Ferrite Number; neural network; duplex stainless steel; austenitic stainless steel; ferrite content; cooling rate; alloy composition; constitution diagram ID STAINLESS-STEEL WELDS; ARTIFICIAL NEURAL NETWORKS; METAL; 304-STAINLESS-STEEL AB A new Ferrite Number prediction model, ORFN (Oak Ridge Ferrite Number), was developed in Part 1 of this study (Welding Journal, January 2003) and, in this contribution, the model predictions are evaluated and compared with predictions of other models. The ORFN quantitatively takes account of cooling rate effects on the Ferrite Number for the first time. It is shown the new ORFN model presents very good agreement with experimental data and is significantly more accurate than existing constitution diagrams or recently developed composition-only neural network models., The model is equally valid for austenitic stainless steels and duplex stainless steels. Furthermore, the model is applicable to both conventional arc welding conditions as well as high cooling rate conditions prevalent during high energy beam welding, such as laser beam welding, and high-speed arc welding. C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Vitek, JM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 19 TC 16 Z9 16 U1 2 U2 2 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD FEB PY 2003 VL 82 IS 2 BP 43S EP 50S PG 8 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 746VH UT WOS:000186768000014 ER PT J AU Cooper, DI Eichinger, WE Archuleta, J Hipps, L Kao, J Leclerc, MY Neale, CM Prueger, J AF Cooper, DI Eichinger, WE Archuleta, J Hipps, L Kao, J Leclerc, MY Neale, CM Prueger, J TI Spatial source-area analysis of three-dimensional moisture fields from lidar, eddy covariance, and a footprint model SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE spatial source-area analysis; three-dimensional moisture; latent energy flux ID BOUNDARY-LAYER; SURFACE-LAYER; VARIABILITY; FOREST AB The Los Alamos National Laboratory scanning Raman lidar was used to measure the three-dimensional moisture field over a salt cedar canopy. A critical question concerning these measurements is; what are the spatial properties of the source region that contributes to the observed three-dimensional moisture field? Traditional methods used to address footprint properties rely on point sensor time-series data and the assumption of Taylor's hypothesis to transform temporal data-into the spatial domain. In this paper, the analysis of horizontal source-area size is addressed from direct lidar-based spatial analysis of the moisture field, eddy covariance co-spectra, and a dedicated footprint model. The results of these analysis techniques converged on the microscale average source region of between 25 and 75 m under ideal conditions. This work supports the concept that the scanning lidar can be used to map small scale boundary layer processes, including riparian zone moisture fields and fluxes. Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Iowa, Iowa City, IA 52242 USA. Utah State Univ, Logan, UT 84322 USA. Univ Georgia, Griffin, GA 30223 USA. USDA ARS, Natl Soil Tilth Lab, Ames, IA 50011 USA. RP Cooper, DI (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Neale, Christopher/G-3860-2012; Neale, Christopher/P-3676-2015 OI Hipps, Lawrence/0000-0002-7658-8571; Neale, Christopher/0000-0002-7199-6410; Neale, Christopher/0000-0002-7199-6410 NR 31 TC 20 Z9 20 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD JAN 31 PY 2003 VL 114 IS 3-4 BP 213 EP 234 AR PII S0168-1923(02)00175-2 DI 10.1016/S0168-1923(02)00175-2 PG 22 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 635UL UT WOS:000180417800006 ER PT J AU He, HZ Ding, Y Bartlam, M Sun, F Le, Y Qin, XC Tang, H Zhang, RG Joachimiak, A Liu, JY Zhao, NM Rao, ZH AF He, HZ Ding, Y Bartlam, M Sun, F Le, Y Qin, XC Tang, H Zhang, RG Joachimiak, A Liu, JY Zhao, NM Rao, ZH TI Crystal structure of tabtoxin resistance protein complexed with acetyl coenzyme A reveals the mechanism for beta-lactam acetylation SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE acetyl coenzyme A; crystal structure; GCN5-related N-acetyltransferase superfamily; histone acetyltransferase; tabtoxin resistance protein ID GCN5-RELATED N-ACETYLTRANSFERASE; SYRINGAE PV TABACI; HISTONE ACETYLTRANSFERASES; CHROMATIN STRUCTURE; SUBSTRATE-BINDING; SUPERFAMILY; TOXIN; TRANSCRIPTION; FEATURES AB Tabtoxin resistance protein (TTR) is an enzyme that renders tabtoxin-producing pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. Here, we report the crystal structure of TTR complexed with its natural cofactor, acetyl coenzyme A (AcCoA), to 1.55 Angstrom resolution. The binary complex forms a characteristic "V" shape for substrate binding and contains the four motifs conserved in the GCN5-related N-acetyl-transferase (GNAT) superfamily, which also includes the histone acetyl-transferases (HATs). A single-step mechanism is proposed to explain the function of three conserved residues, Glu92, Asp130 and Tyr141, in catalyzing the acetyl group transfer to its substrate. We also report that TTR possesses HAT activity and suggest an evolutionary relationship between TTR and other GNAT members. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Tsing Hua Univ, Sch Life Sci & Engn, Lab Struct Biol, Beijing 100084, Peoples R China. Tsing Hua Univ, Sch Life Sci & Engn, MOE Lab Prot Sci, Beijing 100084, Peoples R China. Chinese Acad Sci, Inst Microbiol, Beijing 100080, Peoples R China. Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. RP Rao, ZH (reprint author), Tsing Hua Univ, Sch Life Sci & Engn, Lab Struct Biol, Beijing 100084, Peoples R China. NR 39 TC 36 Z9 40 U1 2 U2 6 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JAN 31 PY 2003 VL 325 IS 5 BP 1019 EP 1030 DI 10.1016/S0022-2836(02)01284-6 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 640EY UT WOS:000180676300012 PM 12527305 ER PT J AU Bulaevskii, LN Ortiz, G AF Bulaevskii, LN Ortiz, G TI Tunneling measurement of a single quantum spin SO PHYSICAL REVIEW LETTERS LA English DT Article ID SILICON; STM AB Measurement of the tunneling current of spin-polarized electrons via a molecule with a localized spin provides information on the orientation of that spin. We show that a strong tunneling current due to the shot noise suppresses the spin dynamics, such as the spin precession in an external magnetic field, and the relaxation due to the environment (quantum Zeno effect). A weak tunneling current preserves the spin precession with the oscillatory component of the current of the same order as the noise. We propose an experiment to observe the Zeno effect in a tunneling system and describe how the tunneling current may be used to read a qubit represented by a single spin 1/2. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Bulaevskii, LN (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 17 TC 25 Z9 25 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 31 PY 2003 VL 90 IS 4 AR 040401 DI 10.1103/PhysRevLett.90.040401 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000001 PM 12570405 ER PT J AU Gurevich, A Vinokur, VM AF Gurevich, A Vinokur, VM TI Interband phase modes and nonequilibrium soliton structures in two-gap superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHENOMENOLOGICAL THEORY; MGB2 AB We predict a new dynamic state in current-carrying superconductors with a multicomponent order parameter. If the current density J exceeds a critical value J(t), an interband breakdown caused by charge imbalance of nonequilibrium quasiparticles occurs. For J>J(t), the electric field penetrating from current leads gives rise to various static and dynamic soliton phase textures, and voltage oscillations similar to the nonstationary Josephson effect. We propose experiments to observe these effects which would probe the multicomponent nature of the superconducting order parameter. C1 Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Gurevich, A (reprint author), Univ Wisconsin, Ctr Appl Superconduct, 1500 Johnson Dr, Madison, WI 53706 USA. RI Gurevich, Alex/A-4327-2008 OI Gurevich, Alex/0000-0003-0759-8941 NR 19 TC 67 Z9 67 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 31 PY 2003 VL 90 IS 4 AR 047004 DI 10.1103/PhysRevLett.90.047004 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000047 PM 12570451 ER PT J AU Kusnezov, D Ormand, WE AF Kusnezov, D Ormand, WE TI Giant-dipole resonance and the deformation of hot, rotating nuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID INELASTIC ALPHA-SCATTERING; HIGH-EXCITATION ENERGY; FINITE-TEMPERATURE; EXCITED NUCLEI; SHAPE; SN-120; WIDTH; DECAY; FLUCTUATIONS; PB-208 AB The development of nuclear shapes under the extreme conditions of high angular momentum and/or temperature is examined. Scaling properties are used to demonstrate universal properties of both thermal expectation values of nuclear shapes as well as the minima of the free energy, which can be used to understand the Jacobi transition. A universal correlation between the width of the giant-dipole resonance and quadrupole deformation is found, providing a novel probe to measure the nuclear deformation in hot nuclei. C1 Yale Univ, Sloane Phys Lab, Ctr Theoret Phys, New Haven, CT 06520 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kusnezov, D (reprint author), Yale Univ, Sloane Phys Lab, Ctr Theoret Phys, New Haven, CT 06520 USA. NR 31 TC 24 Z9 24 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 31 PY 2003 VL 90 IS 4 AR 042501 DI 10.1103/PhysRevLett.90.042501 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000008 PM 12570412 ER PT J AU Lopatin, AV Vinokur, VM AF Lopatin, AV Vinokur, VM TI Quantum tunneling between paramagnetic and superconducting states of a nanometer-scale superconducting grain placed in a magnetic field SO PHYSICAL REVIEW LETTERS LA English DT Article AB We consider the process of quantum tunneling between the superconducting and paramagnetic states of a nanometer-scale superconducting grain placed in a magnetic field. The grain is supposed to be weakly coupled to a normal metallic contact that plays the role of the spin reservoir. Using the instanton method, we find the probability of the quantum tunneling process and express it in terms of the applied magnetic field, order parameter of the superconducting grain, and conductance of the tunneling junction between the grain and metallic contact. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lopatin, AV (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 31 PY 2003 VL 90 IS 4 AR 047003 DI 10.1103/PhysRevLett.90.047003 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000046 PM 12570450 ER PT J AU McCarty, KF Bartelt, NC AF McCarty, KF Bartelt, NC TI Role of bulk thermal defects in the reconstruction dynamics of the TiO2(110) surface SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; PHASE; DIFFRACTION; MORPHOLOGY; OXIDE; TIO2 AB We use low-energy electron microscopy to show that changing the temperature of oxygen-deficient, rutile-structure crystals causes steps on the (110) surfaces to move. This motion occurs because the concentration of bulk oxygen vacancies changes with temperature, requiring that material be added to or subtracted from the surface. During cooling below a bulk-stoichiometry-dependent temperature, the surface reconstructs into a 1x2 structure in the regions surface steps have swept through, showing that the structural and compositional changes needed to form the 1x2 phase are facilitated by the surface-to-bulk mass flow. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP McCarty, KF (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. RI McCarty, Kevin/F-9368-2012; Bartelt, Norman/G-2927-2012 OI McCarty, Kevin/0000-0002-8601-079X; NR 20 TC 35 Z9 35 U1 1 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 31 PY 2003 VL 90 IS 4 AR 046104 DI 10.1103/PhysRevLett.90.046104 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000034 PM 12570438 ER PT J AU Reichhardt, C Reichhardt, CJO AF Reichhardt, C Reichhardt, CJO TI Charge transport transitions and scaling in disordered arrays of metallic dots SO PHYSICAL REVIEW LETTERS LA English DT Article ID CURRENT-VOLTAGE CHARACTERISTICS; FLUX-LINE-LATTICE; VORTEX LATTICES; CONDUCTION THRESHOLD; 2-DIMENSIONAL ARRAYS; DRIVEN LATTICES; DYNAMICS; BEHAVIOR; FLOW; SYSTEMS AB We examine the charge transport through disordered arrays of metallic dots using numerical simulations. We find power law scaling in the current-voltage curves for arrays containing no voids, while for void-filled arrays charge bottlenecks form and a single scaling is absent, in agreement with recent experiments. In the void-free case we also show that the scaling exponent depends on the effective dimensionality of the system. For increasing applied drives we find a transition from 2D disordered filamentary flow near threshold to a 1D smectic flow which can be identified experimentally using characteristics in the transport curves and conduction noise. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Reichhardt, C (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. OI Reichhardt, Cynthia/0000-0002-3487-5089 NR 26 TC 45 Z9 45 U1 0 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 31 PY 2003 VL 90 IS 4 AR 046802 DI 10.1103/PhysRevLett.90.046802 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000037 PM 12570441 ER PT J AU Saes, M Bressler, C Abela, R Grolimund, D Johnson, SL Heimann, PA Chergui, M AF Saes, M Bressler, C Abela, R Grolimund, D Johnson, SL Heimann, PA Chergui, M TI Observing photochemical transients by ultrafast x-ray absorption spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXCITED-STATE; FEMTOSECOND DYNAMICS; CHARGE-TRANSFER; FINE-STRUCTURE; PHOTOLYSIS; SPECTRA; LASER; EXAFS AB Accurate determination of the transient electronic structures, which drive photochemical reactions, is crucial in chemistry and biology. We report the detection of transient chemical changes on the picosecond time scale by x-ray-absorption near-edge structure of photoexcited aqueous [Ru(bpy)(3)](2+). Upon ultrashort laser pulse excitation a charge transfer excited state having a 300 ns lifetime is formed. We detect the change of oxidation state of the central Ru atom at its L-3 and L-2 edges, at a temporal resolution of 100 ps with the zero of time unambiguously determined. C1 Univ Lausanne, Inst Phys Mat Condensee, BSP, CH-1015 Lausanne, Switzerland. Paul Scherrer Inst, Swiss Light Source, CH-5232 Villigen, Switzerland. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Labs, Adv Light Source, Berkeley, CA 94720 USA. RP Bressler, C (reprint author), Univ Lausanne, Inst Phys Mat Condensee, BSP, CH-1015 Lausanne, Switzerland. RI Bressler, Christian/G-1864-2010; Johnson, Steven/B-3252-2008 OI Johnson, Steven/0000-0001-6074-4894 NR 20 TC 126 Z9 126 U1 3 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 31 PY 2003 VL 90 IS 4 AR 047403 DI 10.1103/PhysRevLett.90.047403 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000055 PM 12570459 ER PT J AU Sanati, M Wang, LG Zunger, A AF Sanati, M Wang, LG Zunger, A TI Adaptive crystal structures: CuAu and NiPt SO PHYSICAL REVIEW LETTERS LA English DT Article ID FIRST-PRINCIPLES; PHASE-DIAGRAMS; METAL-ALLOYS; ISING-MODEL; STABILITY; LATTICE; AU; AG AB We discover that Au-rich Cu1-xAux and Pt-rich Ni1-xPtx contain a composition range in which there is a quasicontinuum of stable, ordered "adaptive structures" made of (001) repeat units of simple structural motifs. This is found by searching similar to3x10(6) different fcc configurations whose energies are parametrized via a "cluster expansion" of first-principles-calculated total energies of just a few structures. This structural adaptivity is explained in terms of an anisotropic, long-range strain energy. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sanati, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 24 TC 40 Z9 40 U1 2 U2 13 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 31 PY 2003 VL 90 IS 4 AR 045502 DI 10.1103/PhysRevLett.90.045502 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000026 PM 12570430 ER PT J AU Tang, A Watson, JW Aclander, J Alster, J Asryan, G Averichev, Y Barton, D Baturin, V Bukhtoyarova, N Carroll, A Gushue, S Heppelmann, S Leksanov, A Makdisi, Y Malki, A Minina, E Navon, I Nicholson, H Ogawa, A Panebratsev, Y Piasetzky, E Schetkovsky, A Shimanskiy, S Zhalov, D AF Tang, A Watson, JW Aclander, J Alster, J Asryan, G Averichev, Y Barton, D Baturin, V Bukhtoyarova, N Carroll, A Gushue, S Heppelmann, S Leksanov, A Makdisi, Y Malki, A Minina, E Navon, I Nicholson, H Ogawa, A Panebratsev, Y Piasetzky, E Schetkovsky, A Shimanskiy, S Zhalov, D TI n-p short-range correlations from (p, 2p+n) measurements SO PHYSICAL REVIEW LETTERS LA English DT Article ID LARGE MOMENTUM-TRANSFER; SCATTERING AB We studied the C-12(p,2p+n) reaction at beam momenta of 5.9, 8.0, and 9.0 GeV/c. For quasielastic (p,2p) events p(f), the momentum of the knocked-out proton before the reaction, was compared (event by event) with p(n), the coincident neutron momentum. For \p(n)\>k(F)=0.220 GeV/c (the Fermi momentum) a strong back-to-back directional correlation between p(f) and p(n) was observed, indicative of short-range n-p correlations. From p(n) and p(f) we constructed the distributions of c.m. and relative motion in the longitudinal direction for correlated pairs. We also determined that 49+/-13% of events with \p(f)\>k(F) had directionally correlated neutrons with \p(n)\>k(F). C1 Kent State Univ, Dept Phys, Kent, OH 44242 USA. Tel Aviv Univ, Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Ramat Aviv, Israel. Yerevan Phys Inst, Yerevan 375036, Armenia. Brookhaven Natl Lab, Collider Accelerator Dept, Upton, NY 11973 USA. Petersburg Nucl Phys Inst, St Petersburg 188350, Russia. Penn State Univ, Dept Phys, University Pk, PA 16801 USA. Mt Holyoke Coll, Dept Phys, S Hadley, MA 01075 USA. Joint Inst Nucl Res, Dubna 141980, Moscow, Russia. RP Tang, A (reprint author), Kent State Univ, Dept Phys, Kent, OH 44242 USA. NR 14 TC 56 Z9 57 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 31 PY 2003 VL 90 IS 4 AR 042301 DI 10.1103/PhysRevLett.90.042301 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000007 PM 12570411 ER PT J AU Zakharov, LE AF Zakharov, LE TI Magnetic propulsion of intense lithium streams in a tokamak magnetic field SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL WALLS AB This paper describes the effect and gives the theory of magnetic propulsion which allows driving free surface plasma facing liquid lithium streams in tokamaks. In the approximation of a thin flowing layer the MHD equations are reduced to one integrodifferential equation which takes into account the propulsion effect, viscosity, and the drag force due to magnetic pumping and other interactions with the magnetic field. A stability criterion is obtained for stabilization of the "sausage" instability of the streams by centrifugal force. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Zakharov, LE (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 12 TC 8 Z9 9 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 31 PY 2003 VL 90 IS 4 AR 045001 DI 10.1103/PhysRevLett.90.045001 PG 4 WC Physics, Multidisciplinary SC Physics GA 640TA UT WOS:000180703000024 PM 12570428 ER PT J AU Korniss, G Novotny, MA Guclu, H Toroczkai, Z Rikvold, PA AF Korniss, G Novotny, MA Guclu, H Toroczkai, Z Rikvold, PA TI Suppressing roughness of virtual times in parallel discrete-event simulations SO SCIENCE LA English DT Article ID NONEQUILIBRIUM SURFACE GROWTH; SMALL-WORLD NETWORKS; SYSTEMS; ALGORITHMS; MODELS AB In a parallel discrete-event simulation (PDES) scheme, tasks are distributed among processing elements (PEs) whose progress is controlled by a synchronization scheme. For lattice systems with short-range interactions, the progress of the conservative PDES scheme is governed by the Kardar-Parisi-Zhang equation from the theory of nonequilibrium surface growth. Although the simulated (virtual) times of the PEs progress at a nonzero rate, their standard deviation (spread) diverges with the number of PEs, hindering efficient data collection. We show that weak random interactions among the PEs can make this spread nondivergent. The PEs then progress at a nonzero, near-uniform rate without requiring global synchronizations. C1 Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Mississippi State Univ, Dept Phys & Astron, Mississippi State, MS 39762 USA. Mississippi State Univ, ERC Ctr Computat Sci, Mississippi State, MS 39762 USA. Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. Florida State Univ, Ctr Mat Res & Technol, Dept Phys, Tallahassee, FL 32306 USA. Florida State Univ, Sch Computat Sci & Informat Technol, Tallahassee, FL 32306 USA. RP Korniss, G (reprint author), Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, 110 8th St, Troy, NY 12180 USA. RI Toroczkai, Zoltan/A-3421-2008; Korniss, Gyorgy/A-7360-2011 OI Toroczkai, Zoltan/0000-0002-6602-2849; NR 26 TC 97 Z9 99 U1 1 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 31 PY 2003 VL 299 IS 5607 BP 677 EP 679 DI 10.1126/science.1079382 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 640KH UT WOS:000180687700037 PM 12560543 ER PT J AU Gering, KL AF Gering, KL TI Simulations of methane hydrate phenomena over geologic timescales. Part 1: Effect of sediment compaction rates on methane hydrate and free gas accumulations SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE methane; hydrate; simulation; marine sediments; porosity; compaction; advection; transport; Blake Ridge ID CASCADIA MARGIN; BLAKE RIDGE; SEA-FLOOR; GULF; OVERPRESSURE; STABILITY; DEPOSITS; PRESSURE; MEXICO; BASIN AB The focus of this work is a model that describes migration and biogenic formation of methane under conditions representative of dynamic marine basins, and the conversion of soluble methane into either solid hydrate or exsolved gas. Incorporated into the overall model are an accurate phase equilibria model for seawater-methane, a methane source term based on biogenesis data, and a sediment compaction model based on porosity as a function of position, time, and the local volume fractions of hydrate solids and free gas. Simulations have shown that under some compaction scenarios, liquid overpressures reach the lithostatic limit due to permeability constraints, which can diminish the advective transfer of soluble methane within the porous sediment. As such, the formation of methane hydrate can be somewhat of a self-moderating process. The occurrence and magnitude of hydrate formation is directly tied to fundamental parameters such as the compaction/sedimentation rates, liquid advection rates, seafloor depth, geothermal gradient, etc. Results are shown for simulations covering 20 million years, wherein growth profiles for methane hydrate and free gas (neither exceeding 10 vol% at any location) are tracked within a vertical sediment column spanning over 3000 in. A case study is also presented for the Blake Ridge region (Ocean Drilling Program Leg 164, Sites 994, 995, and 997) based on simulations covering 6 Ma, wherein it is concluded that methane migration from compaction-driven advection may account for 15-30% of the total hydrate mass present in this region. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Bechtel BWXT Idaho, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Gering, KL (reprint author), Bechtel BWXT Idaho, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 42 TC 13 Z9 18 U1 3 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JAN 30 PY 2003 VL 206 IS 1-2 BP 65 EP 81 AR PII S0012-821X(02)01075-0 DI 10.1016/S0012-821X(02)01075-0 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 642EY UT WOS:000180792300006 ER PT J AU Chung, SU AF Chung, SU TI Covariant helicity-coupling amplitudes: Principles and examples SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT Workshop on Partial Wave Analysis CY JUN 02-04, 2002 CL CARNEGIE MELLON UNIV, PITTSBURGH, PENNSYLVANIA HO CARNEGIE MELLON UNIV AB A general formulation has been given for constructing covariant helicity-coupling amplitudes involving two-body decays with arbitrary integer spins. In order to illustrate the principles, the case of a spin-1 object decaying into spin-2 and spin-1 particles is treated in some detail. Also given are the helicity-coupling amplitudes for a spin-2 object decaying into a spin-2 and a spin-0 particle. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Chung, SU (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JAN 30 PY 2003 VL 18 IS 3 BP 457 EP 473 DI 10.1142/S0217751X03014381 PG 17 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 647MV UT WOS:000181097600014 ER PT J AU Thoma, U AF Thoma, U TI Combining data sets in a partial wave analysis SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT Workshop on Partial Wave Analysis CY JUN 02-04, 2002 CL CARNEGIE MELLON UNIV, PITTSBURGH, PENNSYLVANIA HO CARNEGIE MELLON UNIV ID QUARK-MODEL; DECAYS; REST; ANNIHILATION; BARYONS; STATE AB Partial wave analyses are often done to extract resonance parameters from data. Using analyses of data from the Crystal Barrel Experiment (LEAR) as an example, it will be shown that this can be done with higher reliability and precision if different data sets containing related information are combined in one analysis. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Thoma, U (reprint author), Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JAN 30 PY 2003 VL 18 IS 3 BP 475 EP 485 DI 10.1142/S0217751X03014393 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 647MV UT WOS:000181097600015 ER PT J AU Song, Z Cai, TH Rodriguez, JA Hrbek, J Chan, ASY Friend, CM AF Song, Z Cai, TH Rodriguez, JA Hrbek, J Chan, ASY Friend, CM TI A novel growth mode of Mo on Au (111) from a Mo(CO)(6) precursor: An STM study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SCANNING TUNNELING MICROSCOPY; DIFFUSION-LIMITED AGGREGATION; EPITAXIAL-GROWTH; RECONSTRUCTED AU(111); THERMAL-DECOMPOSITION; INORGANIC OXIDES; METAL-CARBONYLS; SURFACE; CO; NUCLEATION AB The growth of a submonolayer of metallic Mo prepared by chemical vapor deposition (CVD) Of Mo(CO)(6) on Au(111) was studied by scanning tunneling microscopy (STM). At low coverage, nanoscale Mo clusters grow at the elbow sites and in the fcc regions of the reconstructed Au surface. When the coverage increases, rather than decorating uniformly all elbows as found in physical vapor deposition (PVD), the Mo clusters aggregate but do not coalesce, forming ramified cluster islands. Within the islands, the clusters preferentially aggregate along the fcc troughs and the domain boundaries. At step edges, Mo clusters are found to grow at both upper and lower step edges. Differences between CVD and PVD are attributed to differences in the mobility of the nascent Mo species leading to growth. We hypothesize that the difference in mobility for the CVD process is due to the presence of CO from the precursor molecules. Oxidation of the Mo islands leads to their spreading, proving that the Mo clusters are either three-dimensional above or embedded in the surface of the gold substrate. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. RP Hrbek, J (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Hrbek, Jan/I-1020-2013 NR 61 TC 30 Z9 30 U1 1 U2 6 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 30 PY 2003 VL 107 IS 4 BP 1036 EP 1043 DI 10.1021/jp0270405 PG 8 WC Chemistry, Physical SC Chemistry GA 639VB UT WOS:000180649100021 ER PT J AU Ramirez, AP AF Ramirez, AP TI Magic moments SO NATURE LA English DT Editorial Material C1 Los Alamos Natl Lab, Mat Integrat Sci Lab, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Inst Complex Adapt Matter, Los Alamos, NM 87545 USA. RP Ramirez, AP (reprint author), Los Alamos Natl Lab, Mat Integrat Sci Lab, POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 54 Z9 54 U1 1 U2 11 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 30 PY 2003 VL 421 IS 6922 BP 483 EP 483 DI 10.1038/421483a PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 640DB UT WOS:000180670600024 PM 12556870 ER PT J AU Anthony, PL Arnold, RG Averett, T Band, HR Benmouna, N Boeglin, W Borel, H Bosted, PE Bultmann, SL Court, GR Crabb, D Day, D Decowski, P DePietro, P Egiyan, H Erbacher, R Erickson, R Fatemi, R Frlez, E Griffioen, KA Harris, C Hughes, EW Hyde-Wright, C Igo, G Johnson, J King, P Kramer, K Kuhn, SE Lawrence, D Liang, Y Lindgren, R Lombard-Nielsen, RM McKee, P McNulty, DE Meyer, W Mitchell, GS Mitchell, J Olson, M Penttila, S Peterson, GA Pitthan, R Pocanic, D Prepost, R Prescott, C Raue, BA Reyna, D Ryan, P Rochester, LS Rock, S Rondon-Aramayo, O Sabatie, F Smith, T Sorrell, L St Lorant, S Szalata, Z Terrien, Y Tobias, A Toole, T Trentalange, S Wesselmann, FR Wright, TR Zeier, M Zhu, H Zihlmann, B AF Anthony, PL Arnold, RG Averett, T Band, HR Benmouna, N Boeglin, W Borel, H Bosted, PE Bultmann, SL Court, GR Crabb, D Day, D Decowski, P DePietro, P Egiyan, H Erbacher, R Erickson, R Fatemi, R Frlez, E Griffioen, KA Harris, C Hughes, EW Hyde-Wright, C Igo, G Johnson, J King, P Kramer, K Kuhn, SE Lawrence, D Liang, Y Lindgren, R Lombard-Nielsen, RM McKee, P McNulty, DE Meyer, W Mitchell, GS Mitchell, J Olson, M Penttila, S Peterson, GA Pitthan, R Pocanic, D Prepost, R Prescott, C Raue, BA Reyna, D Ryan, P Rochester, LS Rock, S Rondon-Aramayo, O Sabatie, F Smith, T Sorrell, L St Lorant, S Szalata, Z Terrien, Y Tobias, A Toole, T Trentalange, S Wesselmann, FR Wright, TR Zeier, M Zhu, H Zihlmann, B CA E155 Collaboration TI Precision measurement of the proton and deuteron spin structure functions g(2) and asymmetries A(2) SO PHYSICS LETTERS B LA English DT Article ID DEEP-INELASTIC-SCATTERING; POLARIZED STRUCTURE FUNCTIONS; STRUCTURE-FUNCTION G(1)(N); SUM-RULES; POWER CORRECTIONS; BAG MODEL; TARGET; DEPENDENCE; NUCLEONS; QUARKS AB We have measured the spin struction functions g(2)(p) and g(2)(d) and the virtual photon asymmetries A(2)(p) and A(2)(d) over the kinetmatic range 0.02 less than or equal to x less than or equal to 0.8 and 0.7 less than or equal to Q(2) less than or equal to 20 GeV2 by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH3 and (LiD)-Li-6 targets. Our measured g(2) approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3 reduced matrix elements d(2)(p) and d(2)(n) are less than two standard deviations from zero. The data are inconsistent with the Burkhardt-Cottingham sum rule if there is no pathological behavior as x --> 0. The Efremov-Leader-Teryaev integral is consistent with zero within our measured kinematic range. The absolute value of A(2) is significantly smaller than the A(2) < rootR(1 + A(1))/2- limit. (C) 2002 Elsevier Science B.V. All rights reserved. C1 American Univ, Washington, DC 20016 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. CEA Saclay, DAPNIA Serv Phys Nucl, F-91191 Gif Sur Yvette, France. Florida Int Univ, Miami, FL 33199 USA. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Massachusetts, Amherst, MA 01003 USA. Old Dominion Univ, Norfolk, VA 23529 USA. St Norbert Coll, De Pere, WI 54115 USA. Smith Coll, Northampton, MA 01063 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Univ Virginia, Charlottesville, VA 22901 USA. Coll William & Mary, Williamsburg, VA 23187 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Univ Massachusetts, Amherst, MA 01003 USA. RI Averett, Todd/A-2969-2011; Rondon Aramayo, Oscar/B-5880-2013; Frlez, Emil/B-6487-2013; Day, Donal/C-5020-2015; Sabatie, Franck/K-9066-2015; OI Day, Donal/0000-0001-7126-8934; Sabatie, Franck/0000-0001-7031-3975; Wesselmann, Frank/0000-0001-7834-7977; Hyde, Charles/0000-0001-7282-8120; King, Paul/0000-0002-3448-2306 NR 35 TC 143 Z9 143 U1 0 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 30 PY 2003 VL 553 IS 1-2 BP 18 EP 24 DI 10.1016/S0370-2693(02)03015-0 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 639RC UT WOS:000180642200003 ER PT J AU Zhang, Y Haynes, JA Pint, BA Wright, IG Lee, WY AF Zhang, Y Haynes, JA Pint, BA Wright, IG Lee, WY TI Martensitic transformation in CVD NiAl and (Ni,Pt)Al bond coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 29th International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 2002 CL SAN DIEGO, CALIFORNIA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE martensitic transformation; thermal barrier coating; bond coat; platinum aluminide; rumpling ID CHEMICAL-VAPOR-DEPOSITION; CYCLIC OXIDATION; SCALE ADHESION; BEHAVIOR; PHASE; ALLOYS; SUPERALLOY; ALUMINIDE AB The martensitic phase transformation in single-phase beta-NiAl and (Ni,Pt)Al coatings was investigated. After isothermal exposure to 1150 degreesC for 100 h, the beta phase in both types of coatings was transformed to a martensite phase during cooling to room temperature. Martensitic transformation was also observed in the (Ni,Pt)Al bond coat with and without a YSZ top layer after thermal cycling at 1150 degreesC (700 1-h cycles). The transformation took place due to Al depletion in the coating from the formation of the Al2O3 scale and interdiffusion between the coating and superalloy substrate. The effects of the martensitic transformation on coating surface stability ('rumpling') via volume changes during the phase transformation are discussed with regard to TBC failure. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Tennessee Technol Univ, Dept Mech Engn, Cookeville, TN 38505 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Stevens Inst Technol, Dept Chem Biochem & Mat Engn, Hoboken, NJ 07030 USA. RP Zhang, Y (reprint author), Tennessee Technol Univ, Dept Mech Engn, Cookeville, TN 38505 USA. RI Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 26 TC 95 Z9 97 U1 4 U2 45 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 30 PY 2003 VL 163 BP 19 EP 24 AR PII S0257-8972(02)00585-6 DI 10.1016/S0257-8972(02)00585-6 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 636JG UT WOS:000180450700004 ER PT J AU Nychka, JA Clarke, DR Sridharan, S Jordan, E Gell, M Lance, MJ Chunnilall, CJ Smith, IM Saunders, SRJ Pillan, R Sergo, V Selcuk, A Atkinson, A Murphy, KS AF Nychka, JA Clarke, DR Sridharan, S Jordan, E Gell, M Lance, MJ Chunnilall, CJ Smith, IM Saunders, SRJ Pillan, R Sergo, V Selcuk, A Atkinson, A Murphy, KS TI NDE assessment of TBCs: an interim report of a photo-stimulated luminescence 'round-robin' test SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 29th International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 2002 CL SAN DIEGO, CALIFORNIA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE photo-stimulated luminescence spectroscopy (PSLS); 'round-robin' test; electronic spectra ID ALUMINA AB Photo-stimulated luminescence spectroscopy (PSLS) can be used as a non-destructive tool to gain quantitative information about the stress and strain in the thermally grown oxide (TGO) formed beneath a thermal barrier coating (TBC) and possibly assess damage. In response to the increasing popularity of this technique, a 'round-robin' test has been initiated to compare methods of luminescence collection using different instruments as well as various spectral analysis methods. The interim results of this 'round-robin' are reported here with a series of PSLS measurements and analyses performed at four different laboratories on the same set of electron beam physical vapor deposited (EB-PVD) TBC samples, having undergone various oxidation treatments. In addition, a set of standard electronic spectra (collected from one group) were circulated for analysis in order to compare the curve-fitting methods used by each group. Apart from sample variations, there was very good agreement between the results obtained in the different laboratories, and there were no systematic differences in the data, indicating that present collection and analysis methods are comparable. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Univ Trieste, Dipartimento Ingn Mat & Chim Applicata, I-34127 Trieste, Italy. Univ London Imperial Coll Sci Technol & Med, London, England. Howmet Castings Corp, Whitehall, MI 49461 USA. RP Nychka, JA (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RI Clarke, David/D-2616-2009; Albe, Karsten/F-1139-2011; Lance, Michael/I-8417-2016 OI Lance, Michael/0000-0001-5167-5452 NR 9 TC 27 Z9 27 U1 1 U2 8 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 30 PY 2003 VL 163 BP 87 EP 94 AR PII S0257-8972(02)00596-0 DI 10.1016/S0257-8972(02)00596-0 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 636JG UT WOS:000180450700015 ER PT J AU Monteiro, OR Delplancke-Ogletree, MP AF Monteiro, OR Delplancke-Ogletree, MP TI Investigation of non-hydrogenated DLC : Si prepared by cathodic arc SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 29th International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 2002 CL SAN DIEGO, CA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE nano-indentation hardness; spectroscopy; coefficient of friction; filtered arc deposition; diamond-like carbon; silicon ID X-RAY-ABSORPTION; CARBON-FILMS; DIAMOND-LIKE; THERMAL-STABILITY; SILICON; DEPOSITION; HARDNESS; CARBIDE AB Non-hydrogenated diamond-like carbon (DLC) films (also referred as ta-C) have been extensively studied and are used for a variety of wear related applications. Alloying DLC with refractory metals and other elements have been shown to be promising techniques to overcome some of the problems associated with pure DLC, such as excessive level of intrinsic stresses and high-temperature stability. The microstructure of DLC:Me in general consists of crystalline metal carbides dispersed in a DLC matrix. In contrary, DLC:Si has an amorphous structure. We have used filtered cathodic arc to prepare DLC:Si up to 6% Si, and have characterized their structure and bonding using transmission electron microscopy and X-ray absorption spectroscopy. The effect of Si in changing the bonding configuration of the C network is discussed. The microstructure is then correlated to hardness and friction measured by nano-indentation and micro-wear. (C) 2002 Elsevier Science B.V All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Free Univ Brussels, Dept Ind Chem, B-1050 Brussels, Belgium. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Mail Stop 53-004,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM ormonteiro@lbl.gov NR 20 TC 15 Z9 16 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JAN 30 PY 2003 VL 163 BP 144 EP 148 AR PII S0257-8972(02)00488-7 DI 10.1016/S0257-8972(02)00488-7 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 636JG UT WOS:000180450700023 ER PT J AU Meng, WJ Zhang, XD Shi, B Jiang, JC Rehn, LE Baldo, PM Tittsworth, RC AF Meng, WJ Zhang, XD Shi, B Jiang, JC Rehn, LE Baldo, PM Tittsworth, RC TI Structure and mechanical properties of Ti-Si-N ceramic nanocomposite coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 29th International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 2002 CL SAN DIEGO, CALIFORNIA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE nanostructured ceramics; mechanical properties; physical vapor deposition; chemical vapor deposition ID SUPERHARD; HARDNESS AB We have synthesized a series of Ti-Si-N coatings with 0-20 at.% Si by high-density plasma-assisted vapor phase deposition. Composition, structure and atomic short-range order were characterized by Rutherford backscattering spectrometry (RBS), transmission electron microscopy (TEM), 0-2theta X-ray diffraction (XRD) and X-ray absorption near-edge structure (XANES) spectroscopy. The mechanical properties of these coatings were characterized by instrumented nanoindentation and compared to those of B1-TiN. Our experiments show that the present series of Ti-Si-N coatings are nanocomposites, consisting of a nm-scale mixture of crystalline titanium nitride (TiN) and amorphous silicon nitride (a-Si:N). The hardness of the present series of Ti-Si-N coatings was found to be less than 32 GPa. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. Louisiana State Univ, Ctr Adv Microstruct & Devices, Baton Rouge, LA 70803 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Meng, WJ (reprint author), Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. NR 20 TC 31 Z9 34 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JAN 30 PY 2003 VL 163 BP 251 EP 259 AR PII S0257-8972(02)00603-5 DI 10.1016/S0257-8972(02)00603-5 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 636JG UT WOS:000180450700040 ER PT J AU Sanchez-Lopez, JC Erdemir, A Donnet, C Rojas, TC AF Sanchez-Lopez, JC Erdemir, A Donnet, C Rojas, TC TI Friction-induced structural transformations of diamondlike carbon coatings under various atmospheres SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 29th International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 2002 CL SAN DIEGO, CALIFORNIA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE DLC; friction; testing environment; Raman; EELS ID AMORPHOUS-CARBON; FILMS; HYDROGEN; PERFORMANCE; PLASMAS; WEAR AB Structural transformations that occur in dianiondlike carbon coatings with increasing hydrogen content have been investigated by Raman spectroscopy, transmission electron microscopy, electron diffraction, and electron-energy-loss spectroscopy. Friction tests were performed with uncoated steel balls against coated substrates at contact stresses of I GPa in ambient air (RH=30-40%), dry air (RH < 1%), and dry nitrogen (< 1%). The lowest friction coefficient (f < 0.02) was obtained for the most hydrogenated sample in dry nitrogen, where the formation of a third-body layer was observed on the steel surface. Raman spectra obtained from the counterfaces after sliding in humid and dry air revealed an increase and narrowing of the 'D' and 'G' peaks with decreasing humidity. Analysis of peak positions and I(D)/I(G) ratios suggest an increasing order and an enlargement of the sp(2) clusters under friction. The shape and position of the carbon K-edge spectra for the transfer layer are affected the same way, although evidence of extended graphite layer formation was not observed. Development of these differing trends was correlated with the hydrogen-to-carbon ratio of the gas precursor used during the synthesis and testing environment. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Sevilla, CSIC, Inst Ciencia Mat Sevilla, Seville 41092, Spain. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Univ Jean Monnet, Lab Traitement Signal & Instrumentat, UMR 5516, F-42023 St Etienne, France. RP Sanchez-Lopez, JC (reprint author), Univ Sevilla, CSIC, Inst Ciencia Mat Sevilla, Avda Americo Vespucio S-N, Seville 41092, Spain. RI Sanchez-Lopez, Juan Carlos/K-3424-2014; Rojas, Teresa Cristina/B-8914-2015 OI Sanchez-Lopez, Juan Carlos/0000-0002-3490-6455; Rojas, Teresa Cristina/0000-0001-7684-2421 NR 24 TC 124 Z9 129 U1 7 U2 49 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 30 PY 2003 VL 163 BP 444 EP 450 AR PII S0257-8972(02)00641-2 DI 10.1016/S0257-8972(02)00641-2 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 636JG UT WOS:000180450700068 ER PT J AU Andersson, J Erck, RA Erdemir, A AF Andersson, J Erck, RA Erdemir, A TI Frictional behavior of diamondlike carbon films in vacuum and under varying water vapor pressure SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 29th International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 2002 CL SAN DIEGO, CALIFORNIA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE diamondlike carbon; water vapor pressures; hydrogenated carbon film ID TRIBOLOGICAL PROPERTIES; SUPERLOW FRICTION AB In this study, we investigated the frictional behavior of both hydrogenated and hydrogen-free diamondlike carbon (DLC) films in high vacuum (10(-6) Pa) at room temperature. Water was also introduced into the vacuum chamber to elucidate its effects on DLC film tribology. The hydrogen-free DLC (also referred to as tetrahedral amorphous carbon, or ta-C) was produced by an arc-PVD process, and the highly hydrogenated DLC was produced by plasma-enhanced chemical-vapor deposition. Tribological measurements of these films were made with a pin-on-disc machine with coated steel balls and coated steel discs in matched pairs under a I N load. The ball/disk pairs were rotated at sliding speeds in the range of 0.025-0.075 m/s. In vacuum, the steady-state friction coefficient of ta-C was of the order of 0.6 and the wear was severe, whereas for the highly hydrogenated film, friction was below 0.01, and in an optical microscope no wear could be detected. Adding water vapor to the sliding ta-C system in a vacuum chamber caused friction to decrease monotonically from 0.6 to approximate to0.07. In contrast, adding water vapor to the sliding DLC system caused the friction to increase linearly with pressure from 0.01 to 0.07. The results illustrate the importance of taking into account environmental conditions, especially the presence of water, when DLC films are being considered for a given application. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Energy Technol Div, Argonne, IL 60439 USA. Angstrom Lab, Tribomat Grp, SE-75121 Uppsala, Sweden. RP Erck, RA (reprint author), Argonne Natl Lab, Energy Technol Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Andersson, Joakim/A-3017-2009 OI Andersson, Joakim/0000-0003-2991-1927 NR 17 TC 111 Z9 118 U1 3 U2 34 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 30 PY 2003 VL 163 BP 535 EP 540 AR PII S0257-8972(02)00617-5 DI 10.1016/S0257-8972(02)00617-5 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 636JG UT WOS:000180450700081 ER PT J AU LaViolette, RA Wood, TR McJunkin, TR Noah, KS Podgorney, RK Starr, RC Stoner, DL Glass, RJ AF LaViolette, RA Wood, TR McJunkin, TR Noah, KS Podgorney, RK Starr, RC Stoner, DL Glass, RJ TI Convergent flow observed in a laboratory-scale unsaturated fracture system SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB An experiment was designed to observe water flow in a simple analogue fractured rock network. The fracture network was modeled by the gaps between an array of limestone blocks, whose permutations generated different realizations of the network. Three out of five of these realizations displayed flow convergence, in contrast to that predicted by porous continuum models. Such convergence occurs because fracture intersections act as capillary barriers that integrate or focus flow within the network. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP LaViolette, RA (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. RI McJunkin, Timothy/G-8385-2011 OI McJunkin, Timothy/0000-0002-4987-9170 NR 9 TC 13 Z9 13 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 29 PY 2003 VL 30 IS 2 AR 1083 DI 10.1029/2002GL015775 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 678XW UT WOS:000182892800001 ER PT J AU Weber, R Orsini, D Duan, Y Baumann, K Kiang, CS Chameides, W Lee, YN Brechtel, F Klotz, P Jongejan, P ten Brink, H Slanina, J Boring, CB Genfa, Z Dasgupta, P Hering, S Stolzenburg, M Dutcher, DD Edgerton, E Hartsell, B Solomon, P Tanner, R AF Weber, R Orsini, D Duan, Y Baumann, K Kiang, CS Chameides, W Lee, YN Brechtel, F Klotz, P Jongejan, P ten Brink, H Slanina, J Boring, CB Genfa, Z Dasgupta, P Hering, S Stolzenburg, M Dutcher, DD Edgerton, E Hartsell, B Solomon, P Tanner, R TI Intercomparison of near real time monitors of PM2.5 nitrate and sulfate at the US Environmental Protection Agency Atlanta Supersite SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE particulate matter; PM2.5; instrumentation; ionic aerosol components; sulfate; nitrate; online analysis; semicontinuous; Supersite ID CONTINUOUS AUTOMATED MEASUREMENT; JET AEROSOL COLLECTOR; PARTICULATE MATTER AB Five new instruments for semicontinuous measurements of fine particle (PM2.5) nitrate and sulfate were deployed in the Atlanta Supersite Experiment during an intensive study in August 1999. The instruments measured bulk aerosol chemical composition at rates ranging from every 5 min to once per hour. The techniques included a filter sampling system with automated water extraction and online ion chromatographic (IC) analysis, two systems that directly collected particles into water for IC analysis, and two techniques that converted aerosol nitrate or sulfate either catalytically or by flash vaporization to gaseous products that were measured with gas analyzers. During the one-month study, 15-min integrated nitrate concentrations were low, ranging from about 0.1 to 3.5 mug m(-3) with a mean value of 0.5 mug m(-3). Ten-minute integrated sulfate concentrations varied between 0.3 and 40 mug m(-3) with a mean of 14 mug m(-3). By the end of the one-month study most instruments were in close agreement, with r-squared values between instrument pairs typically ranging from 0.7 to 0.94. Based on comparison between individual semicontinuous devices and 24-hour integrated filter measurements, most instruments were within 20-30% for nitrate (similar to0.1-0.2 mug m(-3)) and 10-15% for sulfate (1-2 mug m(-3)). Within 95% confidence intervals, linear regression fits suggest that no biases existed between the semicontinuous techniques and the 24-hour integrated filter measurements of nitrate and sulfate;, however, for nitrate, the semicontinuous intercomparisons showed significantly less variability than intercomparisons amongst the 24-hour integrated filters. C1 Georgia Inst Technol, Sch Earth & Atmostphere, Atlanta, GA 30332 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Netherlands Energy Res Fdn, ECN, Dept Air Qual, NL-1755 ZG Petten, Netherlands. Texas Tech Univ, Dept Chem, Lubbock, TX 79409 USA. Aerosol Dynam Inc, Berkeley, CA 94710 USA. Atmospher Res & Anal Inc, Cary, NC 27513 USA. Atmospher Res & Anal Inc, Plano, TX 75074 USA. US EPA, Las Vegas, NV 89119 USA. Tennessee Valley Author, Environm Res Ctr, Muscle Shoals, AL 35662 USA. RP Weber, R (reprint author), Georgia Inst Technol, Sch Earth & Atmostphere, 221 Bobby Dodd Way, Atlanta, GA 30332 USA. EM rweber@eas.gatech.edu; douglas.orsini@eas.gatech.edu; kb@eas.gatech.edu; kiang@mindspring.com; wcham@eas.gatech.edu; ynlee@bnl.gov; fredb@bnl.gov; jongejan@ecn.nl; tenbrink@ecn.nl; slanina@ecn.nl; sandy.dasgupta@pop.admin.ttu.edu; susanne@aerosol.us; mark@aerosoldynamics.com; dabsatbak@aol.com; ericedge@gte.net; hartsell@gte.net; Solomon.Paul@epamail.epa.gov; rltanner@tva.gov RI Hering, Susanne/B-1906-2012 NR 12 TC 53 Z9 55 U1 3 U2 25 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 29 PY 2003 VL 108 IS D7 AR 8421 DI 10.1029/2001JD001220 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 679AF UT WOS:000182898300001 ER PT J AU Coe, BJ Jones, LA Harris, JA Brunschwig, BS Asselberghs, I Clays, K Persoons, A AF Coe, BJ Jones, LA Harris, JA Brunschwig, BS Asselberghs, I Clays, K Persoons, A TI Highly unusual effects of pi-conjugation extension on the molecular linear and quadratic nonlinear optical properties of ruthenium(II) ammine complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DONOR-ACCEPTOR POLYENES; ORGANOMETALLIC MEROCYANINES; FIRST HYPERPOLARIZABILITIES; STARK SPECTROSCOPY; FERROCENE C1 Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England. Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. Univ Louvain, Ctr Res Mol Elect & Photon, Lab Chem & Biol Dynam, B-3001 Louvain, Belgium. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Coe, BJ (reprint author), Univ Manchester, Dept Chem, Oxford Rd, Manchester M13 9PL, Lancs, England. RI Brunschwig, Bruce/G-4249-2011 NR 25 TC 108 Z9 109 U1 1 U2 10 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 29 PY 2003 VL 125 IS 4 BP 862 EP 863 DI 10.1021/ja028897i PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 638PN UT WOS:000180579600005 PM 12537472 ER PT J AU Bie, LJ Wang, YX Lin, JH Loong, CK Richardson, JW You, LP Dong, C AF Bie, LJ Wang, YX Lin, JH Loong, CK Richardson, JW You, LP Dong, C TI Synthesis and structure of n=5 member of the A(n+1)Mn(n)O(3n+3)(A(2)O) series SO CHEMISTRY OF MATERIALS LA English DT Article ID MAGNETORESISTANCE; PEROVSKITE; OXIDE; SUPERCONDUCTIVITY; PHASES; FAMILY; BA AB La4Ba2.6Ca1.4(Mn4Ca)O-19, a novel hexagonal perovskite-intergrowth manganate, was synthesized by solid-state reaction. It crystallizes in the space group C2/m (no. 12) with the lattice parameters of a = 9.8394(4) Angstrom, b = 5.6823(2) Angstrom, c = 15.6435(3) Angstrom, and beta = 102.093(5), cell volume of 855.21(5) Angstrom(3), and Z = 2. The structure was investigated by electron, X-ray, and neutron diffraction techniques and fully resolved by refinements of both X-ray and neutron powder diffraction data. The structure can be described as alternate stacking of 6H-type hexagonal perovskite blocks and graphite-like Ca2O sheets. In the hexagonal perovskite block, Mn and Ca cations occupy the octahedral sites of the corner-shearing and face-shearing octahedra, respectively. Preferred La/Ba and Ca/La substitution at the ratio of 7:3 was observed over specific crystallographic sites. La(4)Ba(2.6)Cal(1.4)(Mn4Ca)O-19 is an n = 5 member of the A(n+1)Mn(n)O(3n+3)(Ca2O) series in which 1/5 of the Mn atoms in the 6H-hexagonal perovskite blocks are replaced by Ca. A structural principle that is based on alternate stacking of close-packed [AO(3)] layers and graphite-like sheets is introduced for structural prediction of new hexagonal perovskite intergrowth compounds. C1 Peking Univ, Coll Chem & Mol Engn, State Key Lab Rare Earth Mat Chem & Applicat, Beijing 100871, Peoples R China. Argonne Natl Lab, Intense Pulsed Neutron Source Div, Argonne, IL 60439 USA. Peking Univ, Dept Phys, Electron Microscopy Lab, Beijing 100871, Peoples R China. Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China. RP Lin, JH (reprint author), Peking Univ, Coll Chem & Mol Engn, State Key Lab Rare Earth Mat Chem & Applicat, Beijing 100871, Peoples R China. NR 26 TC 8 Z9 8 U1 0 U2 3 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 28 PY 2003 VL 15 IS 2 BP 516 EP 522 DI 10.1021/cm020706n PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 638ZM UT WOS:000180603200024 ER PT J AU Krstic, PS Schultz, DR AF Krstic, PS Schultz, DR TI Elastic processes involving vibrationally excited molecules in cold hydrogen plasmas SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CHARGE-TRANSFER PROCESSES; CROSS-SECTIONS; SLOW COLLISIONS; SCATTERING; H+; APPROXIMATIONS; SYSTEM; H++H-2 AB We describe here a comprehensive quantum mechanical study of elastic scattering of protons by vibrationally excited hydrogen molecules and of hydrogen atoms by vibrationally excited hydrogen molecular ions, in the range of collision energies from a fraction of an eV to 6 eV. The problem was solved within a treatment considering all inelastic processes between the vibrational states, including excitation, charge transfer and dissociation. This was realized by expanding the problem in vibrational bases of H-2 and H-2(+) which, in addition to all bound states, contained a large number of discretized vibrational continuum states, and solving the resulting set of coupled channel equations. The sudden approximation was applied with regard to rotations of the target molecule, and particular attention has been paid to convergence of the elastic cross sections with the number of partial waves of the projectile. Important plasma transport related moments of the elastic scattering cross section, the momentum transfer and viscosity cross sections, are also reported here and compared with inelastic cross sections for various vibrationally excited states. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Krstic, PS (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 20 TC 19 Z9 19 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JAN 28 PY 2003 VL 36 IS 2 BP 385 EP 398 AR PII S0953-4075(03)53346-6 DI 10.1088/0953-4075/36/2/318 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 642YT UT WOS:000180835500020 ER PT J AU Huang, YY Chen, HL Li, HC Lin, TL Lin, JS AF Huang, YY Chen, HL Li, HC Lin, TL Lin, JS TI Coalescence of crystalline microdomains driven by postannealing in a block copolymer blend SO MACROMOLECULES LA English DT Article ID BUTADIENE DIBLOCK COPOLYMER; TRANSITION; MORPHOLOGY; POLYBUTADIENE; HOMOPOLYMER; MIXTURES C1 Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. Natl Tsing Hua Univ, Dept Engn & Syst Sci, Hsinchu 30013, Taiwan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chen, HL (reprint author), Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. NR 26 TC 13 Z9 13 U1 2 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 28 PY 2003 VL 36 IS 2 BP 282 EP 285 DI 10.1021/ma0213201 PG 4 WC Polymer Science SC Polymer Science GA 638YW UT WOS:000180601500004 ER PT J AU Gupta, RR Lavery, KA Francis, TJ Webster, JRP Smith, GS Russell, TP Watkins, JJ AF Gupta, RR Lavery, KA Francis, TJ Webster, JRP Smith, GS Russell, TP Watkins, JJ TI Self-diffusion of polystyrene in a CO2-swollen polystyrene matrix: A real time study using neutron reflectivity SO MACROMOLECULES LA English DT Article ID SUPERCRITICAL CARBON-DIOXIDE; POLYMER-POLYMER INTERFACES; REACTION-KINETICS; LIGHT-SCATTERING; GLASS-TRANSITION; MOLECULAR-WEIGHT; SOLVENT SYSTEMS; DEPENDENCE; INTERDIFFUSION; COEFFICIENTS AB The self-diffusivities of high molecular weight polystyrene chains in CO2-swollen polystyrene matrices were measured in real time using neutron reflectivity. Bilayer films of hydrogenated and deuterated polystyrene (PS) were prepared on silicon substrates and exposed to compressed CO2 The broadening of the interface between the films as a function of time was determined from the reflectivity profiles, yielding the chain diffusivity. Diffusivity was studied as a function of polymer molecular weight, concentration Of CO2 in the polymer film, and temperature. Nearly an order of magnitude enhancement in the diffusivity of polystyrene chains (M = 2 x 10(5)), from 1.62 x 10(-16) to 9.35 x 10(-1)6 cm(2)/S, was found with a modest increase in the concentration of CO2 in the polystyrene (from 8.9 to 11.3 wt %) at 62 degreesC. This concentration dependence was modeled using the Vrentas-Duda free volume theory. 50-52 At a constant temperature and CO2 pressure the polystyrene diffusivity scaled as M-2.38. The scaling of the self-diffusivity of PS in CO2-swollen PS with T - T-g, where T-g is the glass transition temperature depressed by the presence of the solvent, is discussed. C1 Univ Massachusetts, Dept Chem Engn, Amherst, MA 01003 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. Rutherford Appleton Lab, ISIS, Didcot OX11 0QX, Oxon, England. Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. RP Univ Massachusetts, Dept Chem Engn, Amherst, MA 01003 USA. EM watkins@ecs.umass.edu NR 62 TC 44 Z9 44 U1 2 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD JAN 28 PY 2003 VL 36 IS 2 BP 346 EP 352 DI 10.1021/ma021215r PG 7 WC Polymer Science SC Polymer Science GA 638YW UT WOS:000180601500015 ER PT J AU McCormick, M Reimer, JRA AF McCormick, M Reimer, JRA TI NMR studies of structural phase transitions in random copolymers SO MACROMOLECULES LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; MODEL-FREE APPROACH; POLYPEPTIDE-CHAINS; RELAXATION; DYNAMICS; MACROMOLECULES; RESIDUES; MOTIONS; ACID); C-13 AB Nuclear magnetic resonance (NMR) has been used in conjunction with circular dichroism (CD) and intrinsic viscosity (IV) measurements to probe the phase diagram of poly(L-glutamic acid-ran-L-leucine) (PEL). IV measurements indicate that PEL in aqueous salt solution undergoes a pH-mediated collapsing transition whereby its size decreases by a factor of 2.6 as the pH is decreased from 6.82 to 4.92. CD measurements indicate a pH-mediated helix-coil transition as the pH is increased from less than 5 to greater than 7. NMR relaxation times and nuclear Overhauser effects were obtained as a function of temperature for various phases of the PEL system and analyzed according to various models for polymer dynamics. The results of these analyses are discussed in the context of freezing transitions predicted by contemporary theories of random copolymers. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP McCormick, M (reprint author), Max Planck Inst Polymer Res, Postfach 3148, D-55118 Mainz, Germany. NR 35 TC 2 Z9 2 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 28 PY 2003 VL 36 IS 2 BP 477 EP 485 DI 10.1021/ma021433k PG 9 WC Polymer Science SC Polymer Science GA 638YW UT WOS:000180601500029 ER PT J AU Pak, J Pyda, M Wunderlich, B AF Pak, J Pyda, M Wunderlich, B TI Rigid amorphous fractions and glass transitions in poly(oxy-2,6-dimethyl-1,4-phenylene) SO MACROMOLECULES LA English DT Article ID HEAT-CAPACITY; BEHAVIOR; DSC AB Semicrystalline poly(oxy-2,6-dimethyl-1,4-phenylene), PPO, is the first example of a polymer that has the glass transition of the rigid amorphous fraction (RAF) above the melting temperature of the crystals. Such phase structure does not allow fast melting below the glass transition and hinders recrystallization. The PPO is analyzed by temperature-modulated differential scanning calorimetry. In the standard DSC of PPO with about 30% crystallinity, a melting peak appears at 515 K, but no glass transition can be seen. The reversing heat capacity of the semicrystalline PPO shows no melting, but a glass transition at about 502 K. Annealing below the beginning of melting causes not only the development of a glass transition as known from amorphous PPO but also a reduction in crystallinity. The RAF was calculated from the deficiency between the measured, reversing heat capacity and the expected thermodynamic heat capacity calculated from our data bank. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Pyda, M (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 16 TC 56 Z9 56 U1 1 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 28 PY 2003 VL 36 IS 2 BP 495 EP 499 DI 10.1021/ma021487u PG 5 WC Polymer Science SC Polymer Science GA 638YW UT WOS:000180601500031 ER PT J AU Annis, BK Kim, MH Brown, C AF Annis, BK Kim, MH Brown, C TI Comparison of boson peaks in polypropylenes SO MACROMOLECULES LA English DT Article ID INELASTIC NEUTRON-SCATTERING; FRAGILE GLASS FORMERS; DYNAMICS; MICROSTRUCTURE; TACTICITY; RESONANCE; MELTS C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Annis, BK (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Brown, Craig/B-5430-2009 OI Brown, Craig/0000-0002-9637-9355 NR 17 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 28 PY 2003 VL 36 IS 2 BP 520 EP 521 DI 10.1021/ma0212689 PG 2 WC Polymer Science SC Polymer Science GA 638YW UT WOS:000180601500034 ER PT J AU Manasreh, MO Friedman, DJ Ma, WQ Workman, CL George, CE Salamo, GJ AF Manasreh, MO Friedman, DJ Ma, WQ Workman, CL George, CE Salamo, GJ TI Photoluminescence of metalorganic-chemical-vapor-deposition-grown GaInNAs/GaAs single quantum wells SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; DOT-LIKE BEHAVIOR; LASER-DIODES; GAAS AB Photoluminescence (PL) spectra of interband transitions in GaInNAs/GaAs single quantum wells grown by metalorganic chemical vapor deposition on semi-insulating GaAs substrates were measured at 77 K for several samples grown with different In compositions and dimethylhydrazine (DMH)/III ratios. The results show that the PL intensity increases as the In mole fraction is increased from 0% to 25%, but the PL intensity is degraded for samples with an In mole fraction of 30% or higher. The peak position energies of the PL spectra were investigated as a function of the DMH/III ratio. Thermal annealing effect induced a blueshift in the PL spectra peak position energy in samples grown with high DMH/III ratios. (C) 2003 American Institute of Physics. C1 Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. Univ Arkansas, Dept Elect Engn, Fayetteville, AR 72701 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Arkansas, Dept Phys, Fayetteville, AR 72701 USA. RP Manasreh, MO (reprint author), Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. NR 15 TC 5 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 27 PY 2003 VL 82 IS 4 BP 514 EP 516 DI 10.1063/1.1540731 PG 3 WC Physics, Applied SC Physics GA 638GV UT WOS:000180564000010 ER PT J AU Kent, PRC Zunger, A AF Kent, PRC Zunger, A TI Failure of nitrogen cluster states to emerge into the bandgap of GaAsN with application of pressure SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM-WELLS; ALLOYS; LOCALIZATION; EVOLUTION; GAAS1-XNX; PAIRS; GAP AB The electronic structure of GaAsN alloys was previously described in terms of nitrogen "cluster states" (CS) that exist in the dilute alloy in the bandgap, and "perturbed host states" (PHS) inside the conduction band. As the nitrogen concentration increases, the PHS plunge down in energy overtaking the CS. We show theoretically that the CS respond to the application of pressure in two different ways: the highly localized deep CS emerge (or remain) in the gap, because their pressure coefficient is lower than that of the conduction band minimum. In contrast, the shallow CS (first to be overtaken) hybridize so strongly with the conduction band that their pressure coefficient becomes comparable to that of the conduction states. These states fail to emerge into the gap upon application of pressure because they move, with application of pressure, at a similar rate with conduction states. (C) 2003 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kent, PRC (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Kent, Paul/A-6756-2008; Zunger, Alex/A-6733-2013 OI Kent, Paul/0000-0001-5539-4017; NR 21 TC 29 Z9 29 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 27 PY 2003 VL 82 IS 4 BP 559 EP 561 DI 10.1063/1.1549543 PG 3 WC Physics, Applied SC Physics GA 638GV UT WOS:000180564000025 ER PT J AU Izuhara, T Gheorma, IL Osgood, RM Roy, AN Bakhru, H Tesfu, YM Reeves, ME AF Izuhara, T Gheorma, IL Osgood, RM Roy, AN Bakhru, H Tesfu, YM Reeves, ME TI Single-crystal barium titanate thin films by ion slicing SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON; LAYERS AB Thin barium titanate films, 0.5-8 mum thick, are obtained from a single-crystal bulk sample using ion slicing. The process, based on ion implantation and anodic bonding, separates thin films having areas of similar to1x1 cm(2), from bulk crystals. The quality of the film is characterized by measurement of surface roughness and dielectric properties. The film permittivity retains its single-crystal value. (C) 2003 American Institute of Physics. C1 Columbia Univ, Microelect Sci Labs, New York, NY 10027 USA. SUNY Albany, Dept Phys, Albany, NY 12222 USA. George Washington Univ, Dept Phys, Washington, DC 20052 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Izuhara, T (reprint author), Columbia Univ, Microelect Sci Labs, New York, NY 10027 USA. NR 19 TC 21 Z9 21 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 27 PY 2003 VL 82 IS 4 BP 616 EP 618 DI 10.1063/1.1540727 PG 3 WC Physics, Applied SC Physics GA 638GV UT WOS:000180564000044 ER PT J AU Cich, MJ Johnson, JA Peake, GM Spahn, OB AF Cich, MJ Johnson, JA Peake, GM Spahn, OB TI Crystallographic dependence of the lateral undercut wet etching rate of InGaP in HCl SO APPLIED PHYSICS LETTERS LA English DT Article ID GAAS; IN0.5GA0.5P; H2O2 AB The crystallographic dependence of the lateral etch rate in 12 M HCl of InGaP lattice matched to GaAs has been measured. The etch rate at 20 degreesC is found to have twofold rotational symmetry about [100] and varies between <0.01 mu m/min for mesas oriented along [011] directions and similar to 0.9 mu m/min for mesas 55 degrees and 125 degrees from [011] towards [0<(1)over bar>1]. Etch fronts consist of {111}A planes. The etch rate also depends on the direction of etch step flow, suggesting that reconstruction plays an important role during InGaP wet etching. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mjcich@sandia.gov NR 12 TC 13 Z9 15 U1 2 U2 6 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 27 PY 2003 VL 82 IS 4 BP 651 EP 653 DI 10.1063/1.1540236 PG 3 WC Physics, Applied SC Physics GA 638GV UT WOS:000180564000056 ER PT J AU Wasinger, EC Davis, MI Pau, MYM Orville, AM Zaleski, JM Hedman, B Lipscomb, JD Hodgson, KO Solomon, EI AF Wasinger, EC Davis, MI Pau, MYM Orville, AM Zaleski, JM Hedman, B Lipscomb, JD Hodgson, KO Solomon, EI TI Spectroscopic studies of the effect of ligand donor strength on the Fe-NO bond in intradiol dioxygenases SO INORGANIC CHEMISTRY LA English DT Article ID X-RAY-ABSORPTION; REDUCED PROTOCATECHUATE 3,4-DIOXYGENASE; MAGNETIC CIRCULAR-DICHROISM; NONHEME IRON ENZYMES; SPIN METAL-IONS; ACTIVE-SITE; NITRIC-OXIDE; ELECTRONIC-STRUCTURE; NITROSYL COMPLEXES; THEORETICAL DESCRIPTION AB The geometric and electronic structure of NO bound to reduced protocatechuate 3,4-dioxygenase and its substrate (3,4-dihydroxybenzoate, PCA) complex have been examined by X-ray absorption (XAS), UV-vis absorption (Abs), magnetic circular dichroism (MCD), and variable temperature variable field (VTVH) MCD spectroscopies. The results are compared to those previously published on model complexes described as {FeNO}(7) systems in which an S = 5/2 ferric center is antiferromagnetically coupled to an S = 1 NO-. XAS pre-edge analysis indicates that the Fe-NO units in (FePCD)-P-III{NO-} and (FePCD)-P-III{PCA,NO-} lack the greatly increased pre-edge intensity representative of most {FeNO}(7) model sites. Furthermore, from extended X-ray absorption fine structure (EXAFS) analysis, the (FePCD)-P-III{NO-} and (FePCD)-P-III{PCA,NO-} active sites are shown to have an Fe-NO distance of at least 1.91 Angstrom, approximate to0.2 Angstrom greater than those found in the model complexes. The weakened Fe-NO bond is consistent with the overall lengthening of the bond lengths and the fact that VTVH MCD data show that NO- --> Fe-III CT transitions are no longer polarized along the z-axis of the zero-field splitting tensor. The weaker Fe-NO bond derives from the strong donor interaction of the endogenous phenolate and substrate catecholate ligands, which is observed from the increased intensity in the CT region relative to that of {FeNO}(7) model complexes, and from the shift in XAS edge position to lower energy. As NO is an analogue of O-2, the effect of endogenous ligand donor strength on the Fe-NO bond has important implications with respect to O-2 activation by non-heme iron enzymes. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Minnesota, Dept Biochem Mol Biol & Biophys, Minneapolis, MN 55455 USA. Univ Minnesota, Ctr Met Biocatalysis, Minneapolis, MN 55455 USA. RP Hedman, B (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. OI Lipscomb, John/0000-0002-8158-5594 FU NCRR NIH HHS [RR01209]; NIGMS NIH HHS [GM40392, GM24689, R01 GM024689, R37 GM024689] NR 69 TC 17 Z9 17 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JAN 27 PY 2003 VL 42 IS 2 BP 365 EP 376 DI 10.1021/ic025906f PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 638WC UT WOS:000180594400017 PM 12693216 ER PT J AU Xu, XM Shen, WQ Feng, YC Zhou, DC AF Xu, XM Shen, WQ Feng, YC Zhou, DC TI Charmonium dissociation cross sections and p-A collisions SO NUCLEAR PHYSICS A LA English DT Article DE charmonium dissociation cross sections; proton-nucleus reactions; J/psi,psi ' and chi(c) suppressions ID J/PSI PRODUCTION; HADRONIC MATTER; SUPPRESSION; QUARKONIUM; QCD; POLARIZATION; TEVATRON; MODEL; PSI AB Charmonium dissociations by nucleons are first studied from a quark-quark potential in combination with quark exchange mechanism. Wave functions of nucleons and charmed baryons involved in dissociation reactions result from a fit to mass splittings of baryons with spins and 3/2. Transverse momentum and x(F) distributions of prompt J/psi produced in 800 GeV/c p-Be collisions are calculated by using NRQCD dsigma/d (t) over cap for parton-parton scatterings and taking into account initial transverse-momentum distributions of partons inside nucleons. We emphasize that the new dissociation cross sections of J/psi, psi' and chi(cJ) give rise to remarkable differences of J/psi, psi' and chi(c) suppressions at large negative x(F) in p-W collisions at root(s)NN = 38.8 and 41.6 GeV and p-Au collisions at root(s)NN = 130 GeV. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Dept Phys, Oak Ridge, TN 37831 USA. Acad Sinica, Shanghai Inst Nucl Res, Div Nucl Phys, Shanghai 201800, Peoples R China. Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China. RP Xu, XM (reprint author), Oak Ridge Natl Lab, Dept Phys, Bldg 6011,MS-6373,POB 2008, Oak Ridge, TN 37831 USA. NR 36 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 27 PY 2003 VL 713 IS 3-4 BP 470 EP 497 AR PII S0375-9474(02)01306-4 DI 10.1016/S0375-9474(02)01306-4 PG 28 WC Physics, Nuclear SC Physics GA 633ZT UT WOS:000180315800007 ER PT J AU Baacke, J Cormier, D de Vega, HJ Heitmann, K AF Baacke, J Cormier, D de Vega, HJ Heitmann, K TI Out of equilibrium dynamics of supersymmetry at high energy density SO NUCLEAR PHYSICS B LA English DT Article ID SYMMETRY NON-RESTORATION; SPIN 1/2 FIELD; FINITE-TEMPERATURE; NONEQUILIBRIUM DYNAMICS; SCALAR FIELD; LARGE-N; FRW COSMOLOGY; RENORMALIZATION; MODEL; EVOLUTION AB We investigate the out of equilibrium dynamics of global chiral supersymmetry at finite energy density. We concentrate on two specific models. The first is the massive Wess-Zumino model which we study in a self-consistent one-loop approximation. We find that for energy densities above a certain threshold, the fields are driven dynamically to a point in field space at which the fermionic component of the superfield is massless. The state, however, is found to be unstable, indicating a breakdown of the one-loop approximation. To investigate further, we consider an O(N) massive chiral model which is solved exactly in the large N limit. For sufficiently high energy densities, we find that for late times the fields reach a nonperturbative minimum of the effective potential degenerate with the perturbative minimum. This minimum is a true attractor for O(N) invariant states at high energy densities, and this provides a mechanism for determining which of the otherwise degenerate vacua is chosen by the dynamics. The final state for large energy density is a cloud of massless particles (both bosons and fermions) around this new nonperturbative supersymmetric minimum. By introducing boson masses which softly break the supersymmetry, we demonstrate a see-saw mechanism for generating small fermion masses. We discuss some of the cosmological implications of our results. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Dortmund, Inst Phys, D-44221 Dortmund, Germany. Univ Sussex, Ctr Theoret Phys, Brighton BN1 9QH, E Sussex, England. Univ Paris 06, Phys Theor & Hautes Energies Lab, F-75252 Paris, France. Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA. RP Baacke, J (reprint author), Univ Dortmund, Inst Phys, Postfach 500500, D-44221 Dortmund, Germany. NR 63 TC 2 Z9 2 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 27 PY 2003 VL 649 IS 3 BP 415 EP 448 DI 10.1016/S0550-3213(02)01063-5 PG 34 WC Physics, Particles & Fields SC Physics GA 636LC UT WOS:000180456500001 ER PT J AU Seol, Y Liu, HH Bodvarsson, GS AF Seol, Y Liu, HH Bodvarsson, GS TI Effects of dry fractures on matrix diffusion in unsaturated fractured rocks SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYDRAULIC CONDUCTIVITY; MODEL AB [1] Matrix diffusion has been recognized as an important mechanism affecting solute transport through unsaturated fractured rock, where a significant portion of the fracture network remains relatively dry and inactive in conducting liquid flow. This simulation study shows that dry fractures act as strong diffusion barriers to solute transport when such fractures divide the matrix into discrete blocks. Where fracture surface roughness causes certain amount of direct contact between matrix blocks separated by a dry fracture, the contacts of the matrix blocks provide conduits for liquid flow and molecular diffusion across dry fractures. Simulation results indicate that the presence of dry fractures and their discontinuities can considerably affect solute transport in unsaturated fractured rock, depending on the magnitude of molecular diffusion. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Seol, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, MS 90-1116, Berkeley, CA 94720 USA. NR 12 TC 4 Z9 5 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 25 PY 2003 VL 30 IS 2 AR 1075 DI 10.1029/2002GL016118 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 660EX UT WOS:000181821800007 ER PT J AU Delire, C Foley, JA Thompson, S AF Delire, C Foley, JA Thompson, S TI Evaluating the carbon cycle of a coupled atmosphere-biosphere model SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE carbon cycle in terrestrial biosphere; climate-vegetation interactions; vegetation dynamics; climate model; soil carbon ID COMMUNITY-CLIMATE-MODEL; TRANSFER SCHEME LSX; VEGETATION FEEDBACKS; STOMATAL CONDUCTANCE; LAND BIOSPHERE; WATER-BALANCE; CO2 EXCHANGE; PHOTOSYNTHESIS; PERFORMANCE; DYNAMICS AB [1] We investigate how well a coupled biosphere-atmosphere model, CCM3-IBIS, can simulate the functioning of the terrestrial biosphere and the carbon cycling through it. The simulated climate is compared to observations, while the vegetation cover and the carbon cycle are compared to an off-line version of the biosphere model IBIS forced with observed climatic variables. The simulated climate presents some local biases that strongly affect the vegetation (e.g., a misrepresentation of the African monsoon). Compared to the off-line model, the coupled model simulates well the globally averaged carbon fluxes and vegetation pools. The zonal mean carbon fluxes and the zonal mean seasonal cycle are also well represented except between 0degrees and 20degreesN due to the misrepresentation of the African monsoon. These results suggest that, despite regional biases in climate and ecosystem simulations, this coupled atmosphere-biosphere model can be used to explore geographic and temporal variations in the global carbon cycle. C1 Univ Wisconsin, Ctr SAGE, Gaylord Nelson Inst Environm Studies, Madison, WI 53726 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Delire, C (reprint author), Univ Wisconsin, Ctr SAGE, Gaylord Nelson Inst Environm Studies, 1710 Univ Ave, Madison, WI 53726 USA. NR 43 TC 25 Z9 28 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD JAN 25 PY 2003 VL 17 IS 1 AR 1012 DI 10.1029/2002GB001870 PG 15 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 660FK UT WOS:000181823000002 ER PT J AU Lio, YC Mazin, AV Kowalczykowski, SC Chen, DJ AF Lio, YC Mazin, AV Kowalczykowski, SC Chen, DJ TI Complex formation by the human Rad51B and Rad51C DNA repair proteins and their activities in vitro SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ESCHERICHIA-COLI RECA; HOMOLOGOUS RECOMBINATION; MAMMALIAN-CELLS; STRAND EXCHANGE; CHROMOSOME STABILITY; MOUSE GENES; FAMILY; XRCC2; MEMBER; PURIFICATION C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Drexel Univ, Coll Med, Dept Biochem, Philadelphia, PA 19102 USA. Univ Calif Davis, Div Biol Sci, Sect Microbiol & Mol & Cellular Biol, Ctr Genet & Dev, Davis, CA 95616 USA. RP Lio, YC (reprint author), Lawrence Berkeley Natl Lab, Div Life Sci, MS74-157,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA 74046, CA-092584]; NIGMS NIH HHS [GM-62653] NR 50 TC 89 Z9 96 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 24 PY 2003 VL 278 IS 4 BP 2469 EP 2478 DI 10.1074/jbc.M211038200 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 638FY UT WOS:000180562000055 PM 12427746 ER PT J AU Yan, Z Haddad, PR Fritz, JS AF Yan, Z Haddad, PR Fritz, JS TI Ion chromatography on reversed-phase materials coated with mixed cationic and nonionic surfactants SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 25th International Symposium on Capillary Chromatography CY MAY 13-17, 2002 CL RIVA DEL GARDA, ITALY DE stationary phase, LC; dynamically coated column; surfactants; nonionic surfactant; cationic surfactant ID LOW-CONDUCTIVITY ELUENTS; ANION CHROMATOGRAPHY; CETYLTRIMETHYLAMMONIUM; COLUMNS; RESINS AB Columns suitable for use in anion chromatography can be prepared by coating a packed reversed-phase HPLC column (C-18 silica or polystyrene particles) with a cationic surfactant. The efficiency is improved dramatically by first coating the column with a nonionic surfactant and then subsequently with the cationic surfactant. The thickness of the first coated layer as well as the chemical structure of the surfactant have a major effect on the column performance. Actual separations are included to demonstrate the convenience and practical use of the coated columns. Using this approach, columns with 12 900 theoretical plates for the 15-cm column (or 86 000 plates/m) were produced, giving well shaped peaks with an average asymmetry factor of 1.09. The coated layers were found to be stable, giving retention times with an average relative standard deviation of 1.6% for 12 consecutive runs. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Tasmania, Sch Chem, Australian Ctr Res Separat Sci, Hobart, Tas 7001, Australia. Zhejiang Univ, Dept Chem, Hangzhou 310028, Peoples R China. Iowa State Univ, Dept Chem, Ames, IA USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Haddad, PR (reprint author), Univ Tasmania, Sch Chem, Australian Ctr Res Separat Sci, GPO Box 252-75, Hobart, Tas 7001, Australia. NR 14 TC 8 Z9 11 U1 2 U2 4 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 24 PY 2003 VL 985 IS 1-2 BP 359 EP 365 AR PII S0021-9673(02)01419-X DI 10.1016/S0021-9673(02)01419-X PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 638PX UT WOS:000180580400042 PM 12580504 ER PT J AU Adler, C Ahammed, Z Allgower, C Amonett, J Anderson, BD Anderson, M Averichev, GS Balewski, J Barannikova, O Barnby, LS Baudot, J Bekele, S Belaga, VV Bellwied, R Berger, J Bichsel, H Billmeier, A Bland, LC Blyth, CO Bonner, BE Boucham, A Brandin, A Bravar, A Cadman, RV Caines, H Sanchez, MCD Cardenas, A Carroll, J Castillo, J Castro, M Cebra, D Chaloupka, P Chattopadhyay, S Chen, Y Chernenko, SP Cherney, M Chikanian, A Choi, B Christie, W Coffin, JP Cormier, TM Cramer, JG Crawford, HJ Deng, WS Derevschikov, AA Didenko, L Dietel, T Draper, JE Dunin, VB Dunlop, JC Eckardt, V Efimov, LG Emelianov, V Engelage, J Eppley, G Erazmus, B Fachini, P Faine, V Faivre, J Filimonov, K Finch, E Fisyak, Y Flierl, D Foley, KJ Fu, J Gagliardi, CA Gagunashvili, N Gans, J Gaudichet, L Germain, M Geurts, F Ghazikhanian, V Grachov, O Grigoriev, V Guedon, M Gushin, E Hallman, TJ Hardtke, D Harris, JW Henry, TW Heppelmann, S Herston, T Hippolyte, B Hirsch, A Hjort, E Hoffmann, GW Horsley, M Huang, HZ Humanic, TJ Igo, G Ishihara, A Ivanshin, YI Jacobs, P Jacobs, WW Janik, M Johnson, I Jones, PG Judd, EG Kaneta, M Kaplan, M Keane, D Kiryluk, J Kisiel, A Klay, J Klein, SR Klyachko, A Konstantinov, AS Kopytine, M Kotchenda, L Kovalenko, AD Kramer, M Kravtsov, P Krueger, K Kuhn, C Kulikov, AI Kunde, GJ Kunz, CL Kutuev, RK Kuznetsov, AA Lakehal-Ayat, L Lamont, MAC Landgraf, JM Lange, S Lansdell, CP Lasiuk, B Laue, F Lauret, J Lebedev, A Lednicky, R Leontiev, VM LeVine, MJ Li, Q Lindenbaum, SJ Lisa, MA Liu, F Liu, L Liu, Z Liu, QJ Ljubicic, T Llope, WJ LoCurto, G Long, H Longacre, RS Lopez-Noriega, M Love, WA Ludlam, T Lynn, D Ma, J Majka, R Margetis, S Markert, C Martin, L Marx, J Matis, HS Matulenko, YA McShane, TS Meissner, F Melnick, Y Meschanin, A Messer, M Miller, ML Milosevich, Z Minaev, NG Mitchell, J Moiseenko, VA Moore, CF Morozov, V de Moura, MM Munhoz, MG Nelson, JM Nevski, P Nikitin, VA Nogach, LV Norman, B Nurushev, SB Odyniec, G Ogawa, A Okorokov, V Oldenburg, M Olson, D Paic, G Pandey, SU Panebratsev, Y Panitkin, SY Pavlinov, AI Pawlak, T Perevoztchikov, V Peryt, W Petrov, VA Planinic, M Pluta, J Porile, N Porter, J Poskanzer, AM Potrebenikova, E Prindle, D Pruneau, C Putschke, J Rai, G Rakness, G Ravel, O Ray, RL Razin, SV Reichhold, D Reid, JG Renault, G Retiere, F Ridiger, A Ritter, HG Roberts, JB Rogachevski, OV Romero, JL Rose, A Roy, C Rykov, V Sakrejda, I Salur, S Sandweiss, J Saulys, AC Savin, I Schambach, J Scharenberg, RP Schmitz, N Schroeder, LS Schuttauf, A Schweda, K Seger, J Seliverstov, D Seyboth, P Shahaliev, E Shestermanov, KE Shimanskii, SS Shvetcov, VS Skoro, G Smirnov, N Snellings, R Sorensen, P Sowinski, J Spinka, HM Srivastava, B Stephenson, EJ Stock, R Stolpovsky, A Strikhanov, M Stringfellow, B Struck, C Suaide, AAP Sugarbaker, E Suire, C Sumbera, M Surrow, B Symons, TJM de Toledo, AS Szarwas, P Tai, A Takahashi, J Tang, AH Thomas, JH Thompson, M Tikhomirov, V Tokarev, M Tonjes, MB Trainor, TA Trentalange, S Tribble, RE Trofimov, V Tsai, O Ullrich, T Underwood, DG Buren, GV VanderMolen, AM Vasilevski, IM Vasiliev, AN Vigdor, SE Voloshin, SA Wang, F Ward, H Watson, JW Wells, R Westfall, GD Whitten, C Wieman, H Willson, R Wissink, SW Witt, R Wood, J Xu, N Xu, Z Yakutin, AE Yamamoto, E Yang, J Yepes, P Yurevich, VI Zanevski, YV Zborovsky, I Zhang, H Zhang, WM Zoulkarneev, R Zubarev, AN AF Adler, C Ahammed, Z Allgower, C Amonett, J Anderson, BD Anderson, M Averichev, GS Balewski, J Barannikova, O Barnby, LS Baudot, J Bekele, S Belaga, VV Bellwied, R Berger, J Bichsel, H Billmeier, A Bland, LC Blyth, CO Bonner, BE Boucham, A Brandin, A Bravar, A Cadman, RV Caines, H Sanchez, MCD Cardenas, A Carroll, J Castillo, J Castro, M Cebra, D Chaloupka, P Chattopadhyay, S Chen, Y Chernenko, SP Cherney, M Chikanian, A Choi, B Christie, W Coffin, JP Cormier, TM Cramer, JG Crawford, HJ Deng, WS Derevschikov, AA Didenko, L Dietel, T Draper, JE Dunin, VB Dunlop, JC Eckardt, V Efimov, LG Emelianov, V Engelage, J Eppley, G Erazmus, B Fachini, P Faine, V Faivre, J Filimonov, K Finch, E Fisyak, Y Flierl, D Foley, KJ Fu, J Gagliardi, CA Gagunashvili, N Gans, J Gaudichet, L Germain, M Geurts, F Ghazikhanian, V Grachov, O Grigoriev, V Guedon, M Gushin, E Hallman, TJ Hardtke, D Harris, JW Henry, TW Heppelmann, S Herston, T Hippolyte, B Hirsch, A Hjort, E Hoffmann, GW Horsley, M Huang, HZ Humanic, TJ Igo, G Ishihara, A Ivanshin, YI Jacobs, P Jacobs, WW Janik, M Johnson, I Jones, PG Judd, EG Kaneta, M Kaplan, M Keane, D Kiryluk, J Kisiel, A Klay, J Klein, SR Klyachko, A Konstantinov, AS Kopytine, M Kotchenda, L Kovalenko, AD Kramer, M Kravtsov, P Krueger, K Kuhn, C Kulikov, AI Kunde, GJ Kunz, CL Kutuev, RK Kuznetsov, AA Lakehal-Ayat, L Lamont, MAC Landgraf, JM Lange, S Lansdell, CP Lasiuk, B Laue, F Lauret, J Lebedev, A Lednicky, R Leontiev, VM LeVine, MJ Li, Q Lindenbaum, SJ Lisa, MA Liu, F Liu, L Liu, Z Liu, QJ Ljubicic, T Llope, WJ LoCurto, G Long, H Longacre, RS Lopez-Noriega, M Love, WA Ludlam, T Lynn, D Ma, J Majka, R Margetis, S Markert, C Martin, L Marx, J Matis, HS Matulenko, YA McShane, TS Meissner, F Melnick, Y Meschanin, A Messer, M Miller, ML Milosevich, Z Minaev, NG Mitchell, J Moiseenko, VA Moore, CF Morozov, V de Moura, MM Munhoz, MG Nelson, JM Nevski, P Nikitin, VA Nogach, LV Norman, B Nurushev, SB Odyniec, G Ogawa, A Okorokov, V Oldenburg, M Olson, D Paic, G Pandey, SU Panebratsev, Y Panitkin, SY Pavlinov, AI Pawlak, T Perevoztchikov, V Peryt, W Petrov, VA Planinic, M Pluta, J Porile, N Porter, J Poskanzer, AM Potrebenikova, E Prindle, D Pruneau, C Putschke, J Rai, G Rakness, G Ravel, O Ray, RL Razin, SV Reichhold, D Reid, JG Renault, G Retiere, F Ridiger, A Ritter, HG Roberts, JB Rogachevski, OV Romero, JL Rose, A Roy, C Rykov, V Sakrejda, I Salur, S Sandweiss, J Saulys, AC Savin, I Schambach, J Scharenberg, RP Schmitz, N Schroeder, LS Schuttauf, A Schweda, K Seger, J Seliverstov, D Seyboth, P Shahaliev, E Shestermanov, KE Shimanskii, SS Shvetcov, VS Skoro, G Smirnov, N Snellings, R Sorensen, P Sowinski, J Spinka, HM Srivastava, B Stephenson, EJ Stock, R Stolpovsky, A Strikhanov, M Stringfellow, B Struck, C Suaide, AAP Sugarbaker, E Suire, C Sumbera, M Surrow, B Symons, TJM de Toledo, AS Szarwas, P Tai, A Takahashi, J Tang, AH Thomas, JH Thompson, M Tikhomirov, V Tokarev, M Tonjes, MB Trainor, TA Trentalange, S Tribble, RE Trofimov, V Tsai, O Ullrich, T Underwood, DG Buren, GV VanderMolen, AM Vasilevski, IM Vasiliev, AN Vigdor, SE Voloshin, SA Wang, F Ward, H Watson, JW Wells, R Westfall, GD Whitten, C Wieman, H Willson, R Wissink, SW Witt, R Wood, J Xu, N Xu, Z Yakutin, AE Yamamoto, E Yang, J Yepes, P Yurevich, VI Zanevski, YV Zborovsky, I Zhang, H Zhang, WM Zoulkarneev, R Zubarev, AN CA STAR Collaboration TI Azimuthal anisotropy and correlations in the hard scattering regime at RHIC SO PHYSICAL REVIEW LETTERS LA English DT Article ID RELATIVISTIC NUCLEAR COLLISIONS; PLUS AU COLLISIONS; ELLIPTIC FLOW; ROOT-S(NN)=130 GEV; SIGNATURE; QCD; A+A AB Azimuthal anisotropy (v(2)) and two-particle angular correlations of high p(T) charged hadrons have been measured in Au+Au collisions at roots(NN) = 130 GeV for transverse momenta up to 6 GeV/c, where hard processes are expected to contribute significantly. The two-particle angular correlations exhibit elliptic flow and a structure suggestive of fragmentation of high p(T) partons. The monotonic rise of v(2)(p(T)) for p(T) < 2 GeV/c is consistent with collective hydrodynamical flow calculations. At p(T) > 3 GeV/c, a saturation of v(2) is observed which persists up to p(T) = 6 GeV/c. C1 Univ Frankfurt, D-6000 Frankfurt, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Birmingham, Birmingham, W Midlands, England. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Creighton Univ, Omaha, NE 68178 USA. JINR, Lab High Energy, Dubna, Russia. JINR, Particle Phys Lab, Dubna, Russia. Indiana Univ, Bloomington, IN 47408 USA. Inst Rech Subatom, Strasbourg, France. Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany. Michigan State Univ, E Lansing, MI 48824 USA. Moscow Engn Phys Inst, Moscow 115409, Russia. CUNY City Coll, New York, NY 10031 USA. Ohio State Univ, Columbus, OH 43210 USA. Penn State Univ, University Pk, PA 16802 USA. Inst High Energy Phys, Protvino, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77251 USA. Univ Sao Paulo, Sao Paulo, Brazil. SUBATECH, Nantes, France. Texas A&M Univ, College Stn, TX 77843 USA. Univ Texas, Austin, TX 78712 USA. Warsaw Univ Technol, Warsaw, Poland. Univ Washington, Seattle, WA 98195 USA. Wayne State Univ, Detroit, MI 48201 USA. Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China. Yale Univ, New Haven, CT 06520 USA. RP Adler, C (reprint author), Univ Frankfurt, D-6000 Frankfurt, Germany. RI Skoro, Goran/F-3642-2010; Barnby, Lee/G-2135-2010; Takahashi, Jun/B-2946-2012; Chen, Yu/E-3788-2012; Planinic, Mirko/E-8085-2012; Witt, Richard/H-3560-2012; Castillo Castellanos, Javier/G-8915-2013; Voloshin, Sergei/I-4122-2013; Johnson, Ian/I-2439-2013; Lednicky, Richard/K-4164-2013; Zborovsky, Imrich/G-7964-2014; Sumbera, Michal/O-7497-2014; Skoro, Goran/P-1229-2014; Strikhanov, Mikhail/P-7393-2014; Kisiel, Adam/O-8754-2015; Tikhomirov, Vladimir/M-6194-2015; Chaloupka, Petr/E-5965-2012; Suaide, Alexandre/L-6239-2016; Okorokov, Vitaly/C-4800-2017; OI Barnby, Lee/0000-0001-7357-9904; Takahashi, Jun/0000-0002-4091-1779; Castillo Castellanos, Javier/0000-0002-5187-2779; Sumbera, Michal/0000-0002-0639-7323; Skoro, Goran/0000-0001-7745-9045; Strikhanov, Mikhail/0000-0003-2586-0405; Kisiel, Adam/0000-0001-8322-9510; Tikhomirov, Vladimir/0000-0002-9634-0581; Suaide, Alexandre/0000-0003-2847-6556; Okorokov, Vitaly/0000-0002-7162-5345; Fisyak, Yuri/0000-0002-3151-8377; Grachov, Oleg/0000-0002-4294-9025; Sorensen, Paul/0000-0001-5056-9391; Thomas, James/0000-0002-6256-4536 NR 24 TC 170 Z9 174 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 24 PY 2003 VL 90 IS 3 AR 032301 DI 10.1103/PhysRevLett.032301 PG 6 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200012 PM 12570484 ER PT J AU Chaloupka, JL Rudati, J Lafon, R Agostini, P Kulander, KC DiMauro, LF AF Chaloupka, JL Rudati, J Lafon, R Agostini, P Kulander, KC DiMauro, LF TI Observation of a transition in the dynamics of strong-field double ionization SO PHYSICAL REVIEW LETTERS LA English DT Article ID MULTIPHOTON DOUBLE-IONIZATION; MOMENTUM DISTRIBUTIONS; THRESHOLD IONIZATION; RARE-GASES; ELECTRON; HELIUM; IONS; SPECTROSCOPY; SINGLE AB The double ionization of argon and xenon in an intense laser field has been studied in detail using an electron-ion coincidence technique. The observed double ionization electron spectra in xenon show resonancelike structures here resolved for the first time. In argon, the featureless spectra are consistent with rescattering. This represents a clear transition in the dynamics of strong-field double ionization, analogous to the well-known transition between the tunneling and multiphoton regimes in single ionization. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Ctr Etud Saclay, SPAM, F-91191 Gif Sur Yvette, France. Lawrence Livermore Natl Lab, TAMP, Livermore, CA 94551 USA. RP Chaloupka, JL (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 24 TC 34 Z9 36 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 033002 DI 10.1103/PhysRevLett.90.033002 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200014 PM 12570486 ER PT J AU Chertkov, M Lebedev, V AF Chertkov, M Lebedev, V TI Decay of scalar turbulence revisited SO PHYSICAL REVIEW LETTERS LA English DT Article ID PASSIVE SCALAR; STATISTICS; FLOW AB We demonstrate that at long times the rate of passive scalar decay in a turbulent, or simply chaotic, flow is dominated by regions where mixing is less efficient. We examine two situations. The first is of a spatially homogeneous stationary turbulent flow with both viscous and inertial scales present. It is shown that at large times scalar fluctuations decay algebraically in time at all spatial scales. The second example explains chaotic stationary flow in a disk/pipe. The boundary region of the flow controls the long-time decay, which is algebraic at some transient times, but becomes exponential, with the decay rate dependent on the scalar diffusion coefficient, at longer times. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. LD Landau Theoret Phys Inst, Moscow 117334, Russia. RP Chertkov, M (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Chertkov, Michael/O-8828-2015 NR 19 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 034501 DI 10.1103/PhysRevLett.90.034501 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200019 ER PT J AU Fleming, S Leibovich, AK AF Fleming, S Leibovich, AK TI Resummed photon spectrum in radiative Upsilon decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID EFFECTIVE-FIELD THEORY; Y DECAYS; GLUONS; QCD; QUARKONIUM; HEAVY AB We present a theoretical prediction for the photon spectrum in radiative Y decay including the effects of resumming the end point region, E-gamma-->M-Y/2. Our approach is based on nonrelativistic QCD (NRQCD) and the soft-collinear effective theory. We find that our results give much better agreement with data than the leading order NRQCD prediction. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Fermilab Natl Accelerator Lab, Theory Grp, Batavia, IL 60510 USA. RP Fleming, S (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RI Fleming, Sean/C-3677-2015 OI Fleming, Sean/0000-0002-9553-7198 NR 19 TC 26 Z9 26 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 24 PY 2003 VL 90 IS 3 AR 032001 DI 10.1103/PhysRevLett.90.032001 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200011 PM 12570483 ER PT J AU Knudson, MD Hanson, DL Bailey, JE Hall, CA Asay, JR AF Knudson, MD Hanson, DL Bailey, JE Hall, CA Asay, JR TI Use of a wave reverberation technique to infer the density compression of shocked liquid deuterium to 75 GPa SO PHYSICAL REVIEW LETTERS LA English DT Article ID INSULATOR-METAL TRANSITION; OF-STATE PROPERTIES; MOLECULAR-HYDROGEN; FLUID HYDROGEN; 1-6 MBAR; EQUATION; HUGONIOT; HOT; DISSOCIATION AB A novel approach was developed to probe density compression of liquid deuterium (L-D-2) along the principal Hugoniot. Relative transit times of shock waves reverberating within the sample are shown to be sensitive to the compression due to the first shock. This technique has proven to be more sensitive than the conventional method of inferring density from the shock and mass velocity, at least in this high-pressure regime. Results in the range of 22-75 GPa indicate an approximately fourfold density compression, and provide data to differentiate between proposed theories for hydrogen and its isotopes. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Knudson, MD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 27 TC 96 Z9 103 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 035505 DI 10.1103/PhysRevLett.90.035505 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200033 PM 12570505 ER PT J AU Machida, M AF Machida, M TI Dynamical matching of Josephson vortex lattice with sample edge in layered high-T-c superconductors: Origin of the periodic oscillation of flux flow resistance SO PHYSICAL REVIEW LETTERS LA English DT Article ID JUNCTIONS; INSTABILITIES; VORTICES; ARRAYS; MODES AB We numerically investigate Josephson vortex flow states in layered high-T-c superconductors motivated by a recent experimental observation for accurate periodic magnetic field dependences of the Josephson vortex flow resistance over a wide range of magnetic field (0.5-4.0 T). We confirm in our mesoscale simulations that dynamical matching of Josephson vortex lattice with sample edge is responsible for the periodic dependence. The present simulations reveal that the Josephson vortex lattice flow speed is particularly suppressed when the moment of vortex entry matches that of vortex escape. Thus, the possible matching situations are taken into account and the observed periodicity is successfully explained. C1 Japan Atom Energy Res Inst, CCSE, Taito Ku, Tokyo 1100015, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Machida, M (reprint author), Japan Atom Energy Res Inst, CCSE, Taito Ku, 6-9-3 Higashi Ueno, Tokyo 1100015, Japan. NR 18 TC 56 Z9 56 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 037001 DI 10.1103/PhysRevLett.90.037001 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200045 PM 12570517 ER PT J AU Marcenat, C Blanchard, S Marcus, J Paulius, LM van der Beek, CJ Konczykowski, M Klein, T AF Marcenat, C Blanchard, S Marcus, J Paulius, LM van der Beek, CJ Konczykowski, M Klein, T TI Anisotropic enhancement of superconductivity in heavy-ion irradiated (K,Ba)BiO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID UPPER CRITICAL-FIELD; HIGH-TEMPERATURE SUPERCONDUCTORS; BOSE-GLASS TRANSITION; COLUMNAR DEFECTS; SINGLE-CRYSTALS; PHASE-TRANSITION; VORTEX; YBA2CU3O7; DISORDER; TL2BA2CUO6+DELTA AB We have measured the specific heat, resistivity, and ac susceptibility of (K,Ba)BiO3 single crystals before and after introduction of either point or columnar defects by electron (EI) or heavy-ion irradiation (HII). While the magnetic field dependence of these properties remains mainly unaffected by EI, the irreversibility line and the location of the specific heat anomaly are both shifted up in temperature after HII. The shift is apparent only if the magnetic field is applied parallel to the ion tracks. For perpendicularly applied fields, both lines lie at the same field as in the pristine sample. These experiments call the nature of the vortex liquid state into question. C1 SPSMS, Dept Rech Fondamentale Mat Condensee, Commissariat Energie Atom Grenoble, F-38054 Grenoble 9, France. CNRS, Etud Proprietes Elect Solides Lab, F-38042 Grenoble, France. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Ecole Polytech, CNRS, UMR 7642, Solides Irradies Lab, F-91128 Palaiseau, France. Ecole Polytech, CEA, DSM, DRECAM, F-91128 Palaiseau, France. Univ Grenoble 1, F-38041 Grenoble 9, France. Inst Univ France, F-38041 Grenoble 9, France. RP Marcenat, C (reprint author), SPSMS, Dept Rech Fondamentale Mat Condensee, Commissariat Energie Atom Grenoble, 17 Rue Martyrs, F-38054 Grenoble 9, France. NR 29 TC 11 Z9 11 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 037004 DI 10.1103/PhysRevLett.90.037004 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200048 PM 12570520 ER PT J AU Nagao, K Bonev, SA Bergara, A Ashcroft, NW AF Nagao, K Bonev, SA Bergara, A Ashcroft, NW TI Enhanced friedel structure and proton pairing in dense solid hydrogen SO PHYSICAL REVIEW LETTERS LA English DT Article ID MEGABAR PRESSURES; ELECTRON AB The mechanism of proton pairing in dense solid hydrogen, and its progression with density, are both studied using effective potentials between protons which include electronic response up to quadratic terms. For high pressures nonlinear effects originating with different pairs are crucial in establishing the net attraction within a given pair, and in this picture Friedel oscillations are considerably enhanced by quadratic response, subsequently playing a very important role in the overall pairing. Calculated vibron frequencies also show substantial agreement with experiment, reflecting at the same time significant changes in the physical character of the pairing itself. C1 Cornell Univ, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Euskal Herriko Unibertsitatea, Zientzia Fak, Mat Kondentsatuaren Fis, Bilbao 48080, Spain. RP Nagao, K (reprint author), Cornell Univ, Atom & Solid State Phys Lab, Clark Hall, Ithaca, NY 14853 USA. RI CSIC-UPV/EHU, CFM/F-4867-2012; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014; Bergara, Aitor/G-2434-2016 NR 19 TC 19 Z9 19 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 035501 DI 10.1103/PhysRevLett.90.035501 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200029 PM 12570501 ER PT J AU Presilla, C Onofrio, R AF Presilla, C Onofrio, R TI Cooling dynamics of ultracold two-species Fermi-Bose mixtures SO PHYSICAL REVIEW LETTERS LA English DT Article ID EINSTEIN CONDENSED GAS; TRAPPED ATOMS; SUPERFLUIDITY; FLOW AB We compare strategies for evaporative and sympathetic cooling of two-species Fermi-Bose mixtures in single-color and two-color optical dipole traps. We show that in the latter case a large heat capacity of the bosonic species can be maintained during the entire cooling process. This could allow one to efficiently achieve a deep Fermi degeneracy regime having at the same time a significant thermal fraction for the Bose gas, crucial for a precise thermometry of the mixture. Two possible signatures of a superfluid phase transition for the Fermi species are discussed. C1 Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Rome 1, Ist Nazl Fis Mat, I-00185 Rome, Italy. Ctr Stat Mech & Complex, I-00185 Rome, Italy. Ist Nazl Fis Nucl, Sez Roma 1, I-00185 Rome, Italy. Univ Padua, Dipartimento Fis G Galilei, I-35131 Padua, Italy. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Univ Roma La Sapienza, Dipartimento Fis, Piazzale Aldo Moro 2, I-00185 Rome, Italy. NR 33 TC 24 Z9 24 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 030404 DI 10.1103/PhysRevLett.90.030404 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200004 PM 12570476 ER PT J AU Raty, JY Galli, G Bostedt, C van Buuren, TW Terminello, LJ AF Raty, JY Galli, G Bostedt, C van Buuren, TW Terminello, LJ TI Quantum confinement and fullerenelike surface reconstructions in nanodiamonds SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-ABSORPTION; INTERSTELLAR DIAMONDS; SI NANOCRYSTALS; OPTICAL GAPS; METEORITES; GRAPHITE; SILICON; DOTS AB We present x-ray absorption and emission experiments and ab initio calculations showing that the size of carbon diamond must be reduced to at least 2 nm, in order to observe an increase of its optical gap, at variance with Si and Ge where quantum confinement effects persist up to 6-7 nm. In addition, our calculations show that the surface of nanodiamond particles larger than similar or equal to 1 nm reconstructs in a fullerenelike manner, giving rise to a new family of carbon clusters: bucky diamonds. Signatures of these surface reconstructions are compatible with pre-edge features observed in measured absorption spectra. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Liege B5, B-4000 Cointe Ougree, Belgium. RP Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 30 TC 233 Z9 235 U1 3 U2 57 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 24 PY 2003 VL 90 IS 3 AR 037401 DI 10.1103/PhysRevLett.90.037401 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200049 PM 12570521 ER PT J AU Vesey, RA Cuneo, ME Bennett, GR Porter, JL Adams, RG Aragon, RA Rambo, PK Ruggles, LE Simpson, WW Smith, IC AF Vesey, RA Cuneo, ME Bennett, GR Porter, JL Adams, RG Aragon, RA Rambo, PK Ruggles, LE Simpson, WW Smith, IC TI Demonstration of radiation symmetry control for inertial confinement fusion in double Z-pinch hohlraums SO PHYSICAL REVIEW LETTERS LA English DT Article ID NATIONAL IGNITION FACILITY; DRIVEN HOHLRAUM; ASYMMETRY; DESIGN; POWER AB Simulations of a double Z-pinch hohlraum, relevant to the high-yield inertial-confinement-fusion concept, predict that through geometry design the time-integrated P-2 Legendre mode drive asymmetry can be systematically controlled from positive to negative coefficient values. Studying capsule elongation, recent experiments on Z confirm such control by varying the secondary hohlraum length. Since the experimental trend and optimum length are correctly modeled, confidence is gained in the simulation tools; the same tools predict capsule drive uniformity sufficient for high-yield fusion ignition. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Ktech Corp Inc, Albuquerque, NM 87106 USA. RP Vesey, RA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 25 TC 38 Z9 39 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 24 PY 2003 VL 90 IS 3 AR 035005 DI 10.1103/PhysRevLett.90.035005 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200026 PM 12570498 ER PT J AU Viola, L Knill, E AF Viola, L Knill, E TI Robust dynamical decoupling of quantum systems with bounded controls SO PHYSICAL REVIEW LETTERS LA English DT Article ID ULTRAFAST OPTICAL PULSES; DECOHERENCE; SUPPRESSION; SUBSYSTEMS AB We propose a general procedure for implementing dynamical decoupling of quantum systems without requiring arbitrarily strong, impulsive control actions. This is accomplished by designing continuous decoupling propagators according to Eulerian paths in the decoupling group for the system. Such Eulerian decoupling schemes offer two important advantages over their impulsive counterparts: they are able to enforce the same dynamical symmetrization but with more realistic control resources and, at the same time, they are intrinsically tolerant against a large class of systematic implementation errors. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Viola, L (reprint author), Los Alamos Natl Lab, Mail Stop B256, Los Alamos, NM 87545 USA. NR 22 TC 132 Z9 133 U1 1 U2 10 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 24 PY 2003 VL 90 IS 3 AR 037901 DI 10.1103/PhysRevLett.90.037901 PG 4 WC Physics, Multidisciplinary SC Physics GA 638PJ UT WOS:000180579200053 PM 12570525 ER PT J AU Quigg, C AF Quigg, C TI The next generation of science policy-makers SO SCIENCE LA English DT Letter C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Quigg, C (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 24 PY 2003 VL 299 IS 5606 BP 511 EP 512 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 638EZ UT WOS:000180559800024 PM 12546004 ER PT J AU Huston, MA Brown, JH Allen, AP Gillooly, JF AF Huston, MA Brown, JH Allen, AP Gillooly, JF TI Heat and biodiversity SO SCIENCE LA English DT Letter C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Huston, MA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Huston, Michael/B-1434-2009; Allen, Andrew/B-8045-2011 OI Huston, Michael/0000-0001-9513-1166; Allen, Andrew/0000-0003-0304-7544 NR 4 TC 13 Z9 17 U1 3 U2 20 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 24 PY 2003 VL 299 IS 5606 BP 512 EP 512 DI 10.1126/science.299.5606.512 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 638EZ UT WOS:000180559800025 PM 12546005 ER PT J AU Westneat, MW Betz, O Blob, RW Fezzaa, K Cooper, WJ Lee, WK AF Westneat, MW Betz, O Blob, RW Fezzaa, K Cooper, WJ Lee, WK TI Tracheal respiration in insects visualized with synchrotron X-ray imaging SO SCIENCE LA English DT Article ID VENTILATION; LOCOMOTION AB Insects are known to exchange respiratory gases in their system of tracheal tubes by using either diffusion or changes in internal pressure that are produced through body motion or hemolymph circulation. However, the inability to see inside living insects has limited our understanding of their respiration mechanisms. We used a synchrotron beam to obtain x-ray videos of living, breathing insects. Beetles, crickets, and ants exhibited rapid cycles of tracheal compression and expansion in the head and thorax. Body movements and hemolymph circulation cannot account for these cycles; therefore, our observations demonstrate a previously unknown mechanism of respiration in insects analogous to the inflation and deflation of vertebrate lungs. C1 Field Museum Nat Hist, Dept Zool, Chicago, IL 60605 USA. Univ Kiel, Dept Zool, Kiel, Germany. Clemson Univ, Dept Biol Sci, Clemson, SC 29634 USA. Argonne Natl Lab, Adv Photon Source, Expt Facilities Div, Argonne, IL 60439 USA. Univ Chicago, Dept Organismal Biol & Anat, Chicago, IL 60637 USA. RP Westneat, MW (reprint author), Field Museum Nat Hist, Dept Zool, Chicago, IL 60605 USA. NR 18 TC 139 Z9 146 U1 11 U2 81 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 24 PY 2003 VL 299 IS 5606 BP 558 EP 560 DI 10.1126/science.1078008 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 638EZ UT WOS:000180559800047 PM 12543973 ER PT J AU Abe, E Pennycook, SJ Tsai, AP AF Abe, E Pennycook, SJ Tsai, AP TI Direct observation of a local thermal vibration anomaly in a quasicrystal SO NATURE LA English DT Article ID DECAGONAL QUASI-CRYSTALS; DIFFUSE-SCATTERING; CO; CRYSTALLOGRAPHY; ELASTICITY; CLUSTERS; PHASONS AB Quasicrystals have long-range order with symmetries that are incompatible with periodicity, and are often described with reference to a higher-dimensional analogue of a periodic lattice(1-3). Within the context of this 'hyperspace' crystallography, lattice dynamics of quasicrystals can be described by a combination of lattice vibrations and atomic fluctuations-phonons and phasons(1,4). However, it is difficult to see localized fluctuations in a real-space quasicrystal structure, and so the nature of phason-related fluctuations and their contribution to thermodynamic stability are still not fully understood. Here we use atomic-resolution annular dark-field scanning transmission electron microscopy to map directly the change in thermal diffuse scattering intensity distribution in the quasicrystal, through in situ high-temperature observation of decagonal Al72Ni20Co8. We find that, at 1,100 K, a local anomaly of atomic vibrations becomes significant at specific atomic sites in the structure. The distribution of these localized vibrations is not random but well-correlated, with a quasiperiodic length scale of 2 nm. We are able to explain this feature by an anomalous temperature (Debye-Waller) factor for the Al atoms that sit at the phason-related sites defined within the framework of hyperspace crystallography. The present results therefore provide a direct observation of local thermal vibration anomalies in a solid. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37830 USA. Japan Sci & Technol Corp, Natl Inst Mat Sci, Tsukuba, Ibaraki 3050047, Japan. Japan Sci & Technol Corp, SORST, Tsukuba, Ibaraki 3050047, Japan. RP Abe, E (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37830 USA. NR 31 TC 84 Z9 84 U1 2 U2 32 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 23 PY 2003 VL 421 IS 6921 BP 347 EP 350 DI 10.1038/nature01337 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 637UW UT WOS:000180533000035 PM 12540895 ER PT J AU Berger, EL Bodwin, GT Lee, J AF Berger, EL Bodwin, GT Lee, J TI Radiative decay of Upsilon (nS) into S-wave sbottornonium SO PHYSICS LETTERS B LA English DT Article DE upsilon decay; bottom squark; gluino; quarkonium ID SCALAR BOTTOM QUARK; ANNIHILATION; SQUARKS; SPECTRA; SEARCH; MASS; E+E; FIT AB A calculation is presented of the radiative decay of the Y(nS) into a bound state of bottom squarks. Predictions are provided of the branching fraction as a function of the masses of the bottom squark and the gluino. Branching fractions as large as several times 10(-4) are obtained for supersymmetric particle masses in the range suggested by the analysis of bottom-quark production cross sections. Data are shown that limit the range of allowed masses. Forthcoming high-statistics data from the CLEO Collaboration offer possibilities of discovery or significant new bounds on the existence and masses of supersymmetric particles. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. RP Berger, EL (reprint author), Argonne Natl Lab, HEP Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 26 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 23 PY 2003 VL 552 IS 3-4 BP 223 EP 228 DI 10.1016/S0370-2693(02)03127-1 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 638QZ UT WOS:000180582900015 ER PT J AU Trivedi, R Jin, F Anderson, IE AF Trivedi, R Jin, F Anderson, IE TI Dynamical evolution of microstructure in finely atomized droplets of Al-Si alloys SO ACTA MATERIALIA LA English DT Article DE atomization; aluminum alloys; eutectic solidification; microstructure; nucleation ID RAPID SOLIDIFICATION CONDITIONS; EUTECTIC GROWTH; DENDRITIC GROWTH; METALLIC ALLOYS; MELTS AB The complex time-dependent evolution of microstructure in rapidly solidified droplets of Al-Si eutectic alloys is quantitatively studied. Fine droplets of the alloy were obtained by using a high pressure gas atomization technique. The recalescence effect within each droplet gives rise to non-steady state growth conditions that lead to a systematic variation in microstructure across the droplet. This variation in microstructure is quantitatively characterized first by determining the nucleation undercooling and then by measuring the spatial variation in microstructural scales within the droplet. The results are compared with theoretical models to obtain the interface velocity and interface undercooling as a function of distance from the apparent nucleation site in different sized droplets. Eutectic, dendritic and cellular microstructures have been observed in droplets and the presence of these different morphologies is explained by constructing a microstructure map for the Al-Si system. The volume fractions of these three microstructures, as well as the length scale of each microstructure, are shown to determine the properties of the material. Specifically, microhardness measurements have been carried out for different diameter droplets, and a minimum in the microhardness is observed that is related to the presence of different microstructures. A microstructure map is developed for the Al-Si system to establish regimes of alloy composition and undercooling (as related to droplet diameter) required for the design of materials with optimum mechanical properties. (C) 2002 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc. C1 Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Trivedi, R (reprint author), Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. NR 24 TC 48 Z9 50 U1 3 U2 18 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 22 PY 2003 VL 51 IS 2 BP 289 EP 300 DI 10.1016/S1359-6454(02)00226-4 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 643CR UT WOS:000180844800001 ER PT J AU Kim, J Barmak, K Lewis, LH AF Kim, J Barmak, K Lewis, LH TI L1(o)-CoPt/Co bilayer ferromagnetic films: interdiffusion, structure and microstructure SO ACTA MATERIALIA LA English DT Article ID EXCHANGE-SPRING BEHAVIOR; CR THIN-FILMS; TETRAGONAL PTCO; CO-CR; COPT/CO; MULTILAYERS; DIFFRACTION; DIFFUSION; MAGNETS; PT(111) AB Detailed understanding of the connections between nanostructure and magnetic properties is key to the realization of optimal exchange-spring magnets. To this end, x-ray and electron diffraction and transmission electron microscopy were used to study the evolution of phases, microstructure and texture of model exchange-spring bilayers of L1(0)-CoPt/Co upon annealing at temperatures ranging from 300-550 degreesC. The work was motivated by previously detailed changes in the magnetic exchange coupling of the system induced by the annealing treatments [1]. Unannealed CoPt/Co bilayers comprised a [111] fiber-textured L1(0) CoPt layer and a [0001] fiber-textured Co layer. The Co layer predominantly consisted of the hcp (A3) form, but contained a minority fcc (A I) phase. Annealing the bilayers at low temperatures (300-450 degreesC) or for short times resulted in a strengthening of the hcp Co [0001] fiber texture and disappearance of the minor fee phase. By contrast, annealing at higher temperatures (450-550 degreesC)Q or for longer times resulted in the interdiffusion of the Co and CoPt layers and the formation of new Co-Pt solid solutions. One of these solid solutions was found to be hcp in structure, while the other was fcc. The amount of the fcc solid solution increased at the expense of the L1(0) CoPt, hcp Co and hcp Co-Pt solid solution phases as annealing time and temperature were increased. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Carnegie Mellon Univ, Ctr Data Storage Syst, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. RP Kim, J (reprint author), Carnegie Mellon Univ, Ctr Data Storage Syst, Pittsburgh, PA 15213 USA. RI Barmak, Katayun/A-9804-2008 OI Barmak, Katayun/0000-0003-0070-158X NR 24 TC 5 Z9 5 U1 0 U2 9 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 22 PY 2003 VL 51 IS 2 BP 313 EP 323 DI 10.1016/S1359-6454(02)00302-6 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 643CR UT WOS:000180844800003 ER PT J AU Kumar, KS Suresh, S Chisholm, MF Horton, JA Wang, P AF Kumar, KS Suresh, S Chisholm, MF Horton, JA Wang, P TI Deformation of electrodeposited nanocrystalline nickel SO ACTA MATERIALIA LA English DT Article DE nanocrystalline metal; deformation; fine structure; in situ microscopy; dimpled rupture ID MOLECULAR-DYNAMICS SIMULATION; GRAIN-BOUNDARIES; MECHANICAL-BEHAVIOR; PLASTIC-DEFORMATION; NANOPHASE MATERIALS; TENSILE BEHAVIOR; METALS; COPPER; PALLADIUM; MICROSTRUCTURE AB The mechanisms of deformation and damage evolution in electrodeposited, fully dense, nanocrystalline Ni with an average grain size of similar to30 nm and a narrow grain size distribution were investigated by recourse to (i) tensile tests performed in situ in the transmission electron microscope and (ii) microscopic observations made at high resolution following ex situ deformation induced by compression, rolling and nanoindentation. Particular attention was also devoted to the characterization of the structure in grain interiors and in the vicinity of grain boundaries at Angstrom-level resolution in the as-deposited material and following compression, and to the real-time video-imaging of the evolution of dislocation activity and damage during deformation; these images are presented in this paper and in the web sites provided as supplementary material to this paper. These observations clearly reveal that dislocation-mediated plasticity plays a dominant role in the deformation of nanocrystalline Ni examined in this study. Fracture surface examination confirms dimpled rupture with the scale of the dimples being several times larger than the grain size. Dislocation emission at grain boundaries together with intragranular slip and unaccommodated grain boundary sliding facilitate the nucleation of voids at boundaries and triple junctions. Individual monocrystal ligaments, formed by the growth/linking of these voids, undergo extensive local plasticity to the extent that many of them neck down to a chisel point. These voids as well as those that may have existed prior to deformation can act as nucleation sites for dimples leading to fracture that does not occur preferentially along grain boundaries. The transmission electron microscopy observations of in situ and ex situ deformed specimens are synthesized to formulate a mechanistic framework that provides new insights into the mechanisms of flow and fracture in nanostructured metals. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Brown Univ, Div Engn, Providence, RI 02912 USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Brown Univ, Div Engn, Box D, Providence, RI 02912 USA. EM sharvan_kumar@brown.edu NR 48 TC 379 Z9 396 U1 25 U2 186 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 22 PY 2003 VL 51 IS 2 BP 387 EP 405 DI 10.1016/S1359-6454(02)00421-4 PG 19 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 643CR UT WOS:000180844800009 ER PT J AU Schuh, CA Nieh, TG Iwasaki, H AF Schuh, CA Nieh, TG Iwasaki, H TI The effect of solid solution W additions on the mechanical properties of nanocrystalline Ni SO ACTA MATERIALIA LA English DT Article DE nanocrystalline metals; solid solution alloys; wear; nanoindentation; Ni-W alloys ID HALL-PETCH RELATION; PULSED ELECTRODEPOSITION; PLASTIC-DEFORMATION; THERMAL-STABILITY; GRAIN-REFINEMENT; FE-NI; NICKEL; COPPER; ALLOYS; STRENGTH AB Although pure metals with grain sizes below about 10 nm are very difficult to prepare, alloying enables the realization of finer grain sizes, often down to the amorphous limit. In this work, the role of solid solution additions of similar to13 at% W are considered with respect to the structure and mechanical properties of electrodeposited Ni alloys with grain sizes below 10 nm. Structure of the nanocrystalline alloys is analyzed by high-resolution transmission electron microscopy, and related to the mechanical properties assessed by instrumented nanoindentation and nano-scratch experiments. The Ni-W alloys exhibit higher hardness and scratch resistance as compared to the finest pure nanocrystalline Ni alloys, although the contribution of solid solution strengthening from W is expected to be essentially negligible. The improved properties are therefore most likely due to the finer length scale available in multicomponent nanocrystalline alloys, and suggest that alloying may suppress the breakdown of Hall-Petch strengthening to finer grain sizes. Finally, the present data are shown to smoothly bridge the hardness-grain size trend between nanocrystalline Ni (grain size > 10 nm) and amorphous Ni-based alloys. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94550 USA. Himeji Inst Technol, Dept Mat Sci & Engn, Himeji, Hyogo 6712201, Japan. RP Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94550 USA. EM nieh1@llnl.gov RI Schuh, Christopher/C-7947-2009; Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 59 TC 238 Z9 246 U1 15 U2 168 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 22 PY 2003 VL 51 IS 2 BP 431 EP 443 DI 10.1016/S1359-6454(02)00427-5 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 643CR UT WOS:000180844800012 ER PT J AU Ko, D Siriwardane, R Biegler, LT AF Ko, D Siriwardane, R Biegler, LT TI Optimization of a pressure-swing adsorption process using zeolite 13X for CO2 sequestration SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID STEADY-STATE CONVERGENCE; SIMULATION; SYSTEMS; DESIGN AB A pressure-swing adsorption process, which uses zeolite 13X as an adsorbent to recover and sequester carbon dioxide from mixture gas (nitrogen and carbon dioxide), is investigated through dynamic simulation and optimization. The purpose of this paper is to improve the purity of each component by finding optimal values of decision variables with a given power constraint. Langmuir isotherm parameters are calculated from experimental data of zeolite 13X and a general mathematical model consisting of a set of partial differential and algebraic equations and solved in gPROMS. The method of centered finite differences is adopted for the discretization of the spatial domains, and a reduced space SQP method is used for the optimization. As a result, the optimal conditions at cyclic steady state are obtained. C1 Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Biegler, LT (reprint author), Carnegie Mellon Univ, Dept Chem Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA. NR 24 TC 138 Z9 142 U1 11 U2 69 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 22 PY 2003 VL 42 IS 2 BP 339 EP 348 DI 10.1021/ie0204540 PG 10 WC Engineering, Chemical SC Engineering GA 638LV UT WOS:000180573200015 ER PT J AU Glaesemann, KR Fried, LE AF Glaesemann, KR Fried, LE TI A path integral approach to molecular thermochemistry SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID GAUSSIAN-BASIS SETS; MONTE-CARLO SIMULATIONS; POTENTIAL-ENERGY SURFACES; DENSITY-FUNCTIONAL THEORY; ANHARMONIC VIBRATIONAL-STATES; AB-INITIO THERMOCHEMISTRY; SHELL PERTURBATION-THEORY; CORRELATED WAVE-FUNCTIONS; ORBITAL METHODS; CONFIGURATION-INTERACTION AB The calculation of thermochemical data requires accurate molecular energies. When such high accuracy is needed, often a method such as G1, G2, or G3 is used to calculate the energy. These methods rely upon the standard harmonic normal mode analysis to calculate the vibrational and rotational contributions to the energy. We present a method for going beyond the harmonic analysis, which uses path integral Monte Carlo to calculate the vibrational and rotational contributions. Anharmonic effects are found to be as large as 2.5 kcal/mol for the molecules studied. Analytical methods for determining an optimal path discretization are presented. A novel potential energy caching scheme, which greatly improves computational efficiency, is also presented. (C) 2003 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Glaesemann, KR (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Glaesemann, Kurt/B-4841-2010; Fried, Laurence/L-8714-2014; OI Fried, Laurence/0000-0002-9437-7700; Glaesemann, Kurt/0000-0002-9512-1395 NR 101 TC 20 Z9 20 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 22 PY 2003 VL 118 IS 4 BP 1596 EP 1603 DI 10.1063/1.1529682 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634AD UT WOS:000180317000006 ER PT J AU Rejoub, R Morton, CD Lindsay, BG Stebbings, RF AF Rejoub, R Morton, CD Lindsay, BG Stebbings, RF TI Electron-impact ionization of the simple alcohols SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CROSS-SECTIONS; ABSOLUTE; THRESHOLD; DETECTOR AB Absolute partial and total cross sections for electron-impact ionization of methanol, ethanol, and 1-propanol are reported for electron energies from threshold to 1000 eV. The product ions are mass analyzed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that all product ion species are collected with equal efficiency irrespective of their initial kinetic energies. The total cross section for each target is obtained as the sum of the partial cross sections. The overall uncertainty in most of the absolute cross sections is +/-6%-8%. Significant discrepancies are seen between the only prior methanol partial cross section determination and this study but the majority of published total cross section measurements and calculations are in good agreement with this work. (C) 2003 American Institute of Physics. C1 Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. RP Rejoub, R (reprint author), Oak Ridge Natl Lab, Div Phys, MS 6372, Oak Ridge, TN 37831 USA. NR 11 TC 35 Z9 35 U1 1 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 2003 VL 118 IS 4 BP 1756 EP 1760 DI 10.1063/1.1531631 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634AD UT WOS:000180317000026 ER PT J AU McMorrow, DF Nagler, SE McEwen, KA Brown, SD AF McMorrow, DF Nagler, SE McEwen, KA Brown, SD TI Large enhancement of x-ray magnetic scattering at the L edges of the 5d transition metal antiferromagnet K2ReCl6 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID RESONANCE EXCHANGE SCATTERING; NEUTRON-DIFFRACTION AB yThe x-ray resonant scattering cross-section of K2ReCl6 has been studied for energies near the L edges of rhenium. Below the Neel temperature of T-N similar to 11 K, additional peaks appear when the photon energy is tuned to the L-II or L-III edges. The peaks are found to rotate the incident (linear) polarization, and have a Lorentzian lineshape in energy. The peaks are ascribed to resonant magnetic scattering, where a dipolar transition connects 2p-5d states. At resonance the scattering amplitude is of order similar tor(0) per atom, roughly two orders of magnitude greater than that of the bare magnetic scattering. C1 Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. RI McMorrow, Desmond/C-2655-2008; Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010 OI McMorrow, Desmond/0000-0002-4947-7788; Nagler, Stephen/0000-0002-7234-2339 NR 24 TC 10 Z9 10 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 22 PY 2003 VL 15 IS 2 BP L59 EP L66 AR PII S0953-8984(03)54975-X DI 10.1088/0953-8984/15/2/108 PG 8 WC Physics, Condensed Matter SC Physics GA 645QD UT WOS:000180989100008 ER PT J AU Shen, J Pierce, JP Plummer, EW Kirschner, J AF Shen, J Pierce, JP Plummer, EW Kirschner, J TI The effect of spatial confinement on magnetism: films, stripes and dots of Fe on Cu(111) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Review ID SELF-ORGANIZED GROWTH; MOLECULAR MAGNETS; STEPPED CU(111); ULTRATHIN FILMS; EXCHANGE BIAS; THIN-FILMS; CU 111; CU(100); SURFACE; ARRAYS AB In this article, we review recent progress in the exploration of the complex magnetic phases of the fee Fe/Cu(111) system. In particular, we emphasize the magnetic properties realized by the synthesis of novel nanostructures of Fe on Cu(111). These include monolayer films, one-dimensional stripe arrays and nanodot arrays. The effects of spatial confinement, together with strong spin-lattice correlations, result in dramatically different magnetic behaviour for the various manifestations of the Fe/Cu(111) system. Multi-scale theoretical calculations have been used to provide an understanding of the magnetic behaviour in each case. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Max Planck Inst Mikrostrukturphys, D-06120 Halle An Der Saale, Germany. RP Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 80 TC 43 Z9 43 U1 1 U2 14 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 22 PY 2003 VL 15 IS 2 BP R1 EP R30 AR PII S0953-8984(03)33359-4 DI 10.1088/0953-8984/15/2/201 PG 30 WC Physics, Condensed Matter SC Physics GA 645QD UT WOS:000180989100013 ER PT J AU Bosman, AW Vestberg, R Heumann, A Frechet, JMJ Hawker, CJ AF Bosman, AW Vestberg, R Heumann, A Frechet, JMJ Hawker, CJ TI A modular approach toward functionalized three-dimensional macromolecules: From synthetic concepts to practical applications SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID FREE-RADICAL POLYMERIZATION; CROSS-LINKED NANOPARTICLES; BLOCK-COPOLYMER MICELLES; STAR POLYMERS; ASYMMETRIC-SYNTHESIS; SIDE-CHAIN; DENDRITIC MACROMOLECULES; CONVERGENT APPROACH; DIBLOCK COPOLYMERS; MEMBRANE REACTOR AB A new strategy for the preparation of functional, multiarm star polymers via nitroxide-mediated "living" radical polymerization has been explored. The generality of this approach to the synthesis of three-dimensional macromolecular architectures allows for the construction of nanoscopically defined materials from a wide range of different homo, block, and random copolymers combining both apolar and polar vinylic repeat units. Functional groups can also be included along the backbone or as peripheral/chain end groups, thereby modulating the reactivity and polarity of defined portions of the stars. This modular approach to the synthesis of three-dimensional macromolecules permits the application of these tailored materials as multifunctional hosts for hydrogen bonding, nanoparticle formation, and as scaffolds for catalytic groups. Examples of applications of the functional stars in catalysis include their use in a Heck-type coupling as well as an enantioselective addition reaction. C1 IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Frechet, JMJ (reprint author), IBM Corp, Almaden Res Ctr, 650 Harry Rd, San Jose, CA 95120 USA. EM frechet@cchem.berkeley.edu; hawker@almaden.ibm.com RI Hawker, Craig/G-4971-2011; OI Hawker, Craig/0000-0001-9951-851X; Frechet, Jean /0000-0001-6419-0163 NR 129 TC 273 Z9 277 U1 3 U2 56 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 22 PY 2003 VL 125 IS 3 BP 715 EP 728 DI 10.1021/ja028392s PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 636QY UT WOS:000180468900029 PM 12526671 ER PT J AU Jacquamet, L Sun, YJ Hatfield, J Gu, WW Cramer, SP Crowder, MW Lorigan, GA Vincent, JB Latour, JM AF Jacquamet, L Sun, YJ Hatfield, J Gu, WW Cramer, SP Crowder, MW Lorigan, GA Vincent, JB Latour, JM TI Characterization of chromodulin by X-ray absorption and electron paramagnetic resonance spectroscopies and magnetic susceptibility measurements SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CHROMIUM-BINDING SUBSTANCE; SATURATION MAGNETIZATION; KINASE-ACTIVITY; OLIGOPEPTIDE; BIOCHEMISTRY; COMPLEXES; PROTEINS; STATE; FORM; FUR AB The biologically active form of the essential trace element chromium is believed to be the oligopeptide chromodulin. Chromodulin binds four chromic ions before binding at or near the active site of activating insulin receptor and subsequently potentiating the tyrosine kinase activity of the receptor. Charge balance arguments and preliminary spectroscopic studies suggested that the chromic centers might be part of a multinuclear assembly. Using a combination of X-ray absorption and electron paramagnetic resonance spectroscopies and variable-temperature magnetic susceptibility measurements, we found that holochromodulin is shown to possess an antiferromagnetically coupled trinuclear assembly which probably weakly interacts with a fourth chromium center. The chromium centers possess octahedron coordination comprised of oxygen-based ligation, presumably derived primarily from oligopeptide-supplied carboxylate groups. X-ray absorption data cannot be reproduced with the presence of sulfur atom(s), indicating that the cysteine thiolate group does not coordinate to the chromium centers. Thus, chromodulin possesses a unique type of multinuclear assembly, distinct from those known in other bioinorganic systems. C1 Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. Univ Alabama, Coalit Biomol Prod, Tuscaloosa, AL 35487 USA. Miami Univ, Dept Chem & Biochem, Oxford, OH 45056 USA. CEA, PMB, DRDC, UJF,CNRS,FRE 2427,Lab Physicochim Metaux Biol, F-38054 Grenoble 9, France. CEA, CNRS, Inst Biol Struct JP Ebel, LCCP, F-38027 Grenoble 1, France. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RP Vincent, JB (reprint author), Univ Alabama, Dept Chem, Box 870336, Tuscaloosa, AL 35487 USA. FU NIGMS NIH HHS [GM-44380] NR 29 TC 46 Z9 48 U1 0 U2 5 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 22 PY 2003 VL 125 IS 3 BP 774 EP 780 DI 10.1021/ja0202661 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 636QY UT WOS:000180468900036 PM 12526678 ER PT J AU Liu, CP Gibson, JM AF Liu, CP Gibson, JM TI Quantitative characterization of self-assembled coherent islands SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT International Conference on Materials for Advanced Technologies (ICMAT2001) CY JUL 01-06, 2001 CL SINGAPORE, SINGAPORE SP Mat Res Soc, Int Union Mat Res Soc DE transmission electron microscopy; heterostructures; coherent islands; strain contrast ID BEAM ELECTRON-DIFFRACTION; GE ISLANDS; STRESS-RELAXATION; SHAPE TRANSITION; GE/SI ISLANDS; STRAIN; SI(001); MICROSCOPY; EVOLUTION; CLUSTERS AB We report on plan-view transmission electron microscopy techniques, by which the size, the actual shape and the strain of a coherent island in semiconductor heterostructures can be measured accurately. The bright-field suppressed-diffraction imaging condition where no strong diffracted beam is excited in the sample provides reliable size measurement as well as the detailed shape and aspect ratio. An exact two-beam diffraction condition is employed to produce the strain contrast of a coherent island and the corresponding fringes can be easily utilized to measure the average strain relaxation occurring during island evolution. We also propose an off-axis z contrast technique for the unambiguous determination of composition profile in an island. Finally examples of application of these techniques on the characterization of Ge coherent islands on Si(1 0 0) substrates are demonstrated. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Cheng Kung Univ, Dept Mat Sci & Engn, Tainan 701, Taiwan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Liu, CP (reprint author), Natl Cheng Kung Univ, Dept Mat Sci & Engn, Tainan 701, Taiwan. EM cpliu@mail.ncku.edu.tw RI Liu, Chuan-Pu /H-8926-2012; Gibson, Murray/E-5855-2013 OI Gibson, Murray/0000-0002-0807-6224 NR 26 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 22 PY 2003 VL 424 IS 1 BP 2 EP 8 AR PII S0040-6090(02)00896-9 DI 10.1016/S0040-6090(02)00896-9 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 672VB UT WOS:000182542700002 ER PT J AU Liu, H Li, ST Fernandez, FE Liu, GK AF Liu, H Li, ST Fernandez, FE Liu, GK TI Optical property of Eu in strontium barium niobate optical thin film grown by pulsed laser deposition SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT International Conference on Materials for Advanced Technologies (ICMAT2001) CY JUL 01-06, 2001 CL SINGAPORE, SINGAPORE SP Mat Res Soc DE laser ablation; fluorescence; optical properties; europium ID CRYSTALS; SPECTROSCOPY AB Thin films of strontium barium niobate SrxBa1-xNb2O6 (SBN) were successfully fabricated on fused quartz substrates using pulsed laser deposition (PLD) technique. The optical and non-linear optical properties were characterized. High-resolution spectroscopic measurements in either time domain or frequency domain were conducted. For undoped SBN thin films, a broadband emission at UV and extending to the visible was observed by excitation at 355 nm. It is attributed to the exciton luminescence of the SBN host in the film. In degenerate four-wave-mixing (DFWM) measurements, a considerable enhancement of the third order susceptibility chi((3)) by 2 orders of magnitude, in transverse alignment was obtained. High-resolution spectroscopic measurements in frequency domain were conducted at the temperatures varying from 270 K down to 2.3 K. The very well resolved fine structure of D-5(0)-F-7 multiplet emission was observed in the annealed sample. The hole-burning experiment shows a hole of width 100 MHz with depth as high as 30% with the laser pumping at 5774 Angstrom. It is suggested that Eu3+ ions may substitute Nb, occupying 6-fold sites. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Puerto Rico, Dept Phys, Mayaguez, PR 00681 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Liu, H (reprint author), Univ Puerto Rico, Dept Phys, Mayaguez, PR 00681 USA. OI Fernandez, Felix/0000-0002-0710-6751 NR 9 TC 8 Z9 9 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 22 PY 2003 VL 424 IS 1 BP 61 EP 65 AR PII S0040-6090(02)00913-6 DI 10.1016/S0040-6090(02)00913-6 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 672VB UT WOS:000182542700012 ER PT J AU Foreman, MB Coffman, JP Murcia, MJ Cesana, S Jordan, R Smith, GS Naumann, CA AF Foreman, MB Coffman, JP Murcia, MJ Cesana, S Jordan, R Smith, GS Naumann, CA TI Gelation of amphiphilic lipopolymers at the air-water interface: 2D analogue to 3D gelation of colloidal systems with grafted polymer chains? SO LANGMUIR LA English DT Article ID OSCILLATORY SHEAR MEASUREMENTS; REVERSIBLE THERMAL GELATION; LENGTHY OXYETHYLENE BLOCKS; PHOSPHOLIPID MONOLAYERS; NEUTRON REFLECTION; AQUEOUS-SOLUTION; FILM BALANCE; X-RAY; VISCOELASTIC PROPERTIES; RHEOLOGICAL PROPERTIES AB Amphiphilic lipopolymers are known to form 2D thermoreversible gels at the air- water interface. Recently, we have reported surface rheology and film balance experiments on poly(ethylene glycol) (PEG) lipopolymers of different molecular weights, which indicated that a sufficient cross-sectional area mismatch between polymer and lipid moieties is necessary to form stable 2D gels (J. Coffman and C. Naumann. Macromolecules 2002, 35, 1835). In the current studies, we have investigated the influence of the hydrophobic anchor on the gelation properties by surface rheology and film balance technique, Experiments on PEG lipopolymers, carrying saturated and partially unsaturated alkyl chains and on poly [(2-n-nonyl -2-oxazoline)(x)-b-(2-methyl-or 2-ethyl-2-oxazoline)(y)] (NxMy or NxEy) diblock copolymers of different block length show that the gel formation is not merely the result of the area mismatch between hydrophilic and hydropliobic Illoieties of the amphiphile (cone shape), but that a sufficient strength of van der Waals interaction within the hydrophobic moiety is necessary for the 2D gel to form, thus verifying carlier predictions that all alkyl chain condensation is a necessary precursor for the gelation process to occur. We also present neutron reflectometry data on PEG lipopolymers above and below the alkyl chain condensation and gelation transitions, which, in agreement to previous neutron and X-ray scattering experiments, reveal that both transitions occur after surface micelles oflipopolymers are formed at the air-water interface. On the basis of these findings, we assume that the gelation process of lipopolymers at the air-water interface is Mused by a surface micellization of lipopolymers, which can be seen as the 2D analogue to the 3D gel formation observed for polymeric colloids with grafted polymer chains, such as, copolymers and star polymers. C1 Indiana Univ Purdue Univ, Dept Chem, Indianapolis, IN 46202 USA. Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Polytech Univ, Dept Chem Chem Engn & Mat Sci, Metrotech Ctr 6, Brooklyn, NY 11201 USA. Tech Univ Munich, Lehrstuhl Makromol Stoffe, D-85747 Garching, Germany. RP Naumann, CA (reprint author), Indiana Univ Purdue Univ, Dept Chem, Indianapolis, IN 46202 USA. EM cnaumann@chem.iupui.edu RI Jordan, Rainer/B-6542-2008 OI Jordan, Rainer/0000-0002-9414-1597 NR 38 TC 40 Z9 40 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JAN 21 PY 2003 VL 19 IS 2 BP 326 EP 332 DI 10.1921/la0261390 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 637NQ UT WOS:000180519200019 ER PT J AU Brem, RF Kieper, DA Rapelyea, JA Majewski, S AF Brem, RF Kieper, DA Rapelyea, JA Majewski, S TI Evaluation of a high-resolution, breast-specific, small-field-of view gamma camera for the detection of breast cancer SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st Topical Symposium on Functional Breast Imaging with Advanced Detectors CY APR 18-21, 2001 CL ROME, ITALY DE breast neoplasms; breast neoplasms, diagnosis; breast neoplasms; redionuclide studies ID TC-99M SESTAMIBI SCINTIMAMMOGRAPHY; PRONE SCINTIMAMMOGRAPHY; TC-99(M)-MIBI SCINTIMAMMOGRAPHY; MAMMOGRAPHY; LESIONS; DIAGNOSIS; METHOXYISOBUTYLISONITRILE; TECHNETIUM-99M-SESTAMIBI; INVOLVEMENT; CARCINOMA AB Purpose: The purpose of our study is to review the state of the art in nuclear medicine imaging of the breast (scintimammography) and to evaluate a novel, high-resolution, breast-specific gamma camera (HRBGC) for the detection of suspicious breast lesions. Materials and Methods: Fifty patients with 58 breast lesions in whom a scintimammogram was clinically indicated were prospectively evaluated with a general-purpose gamma camera and a HRBGC prototype. Nuclear studies were prospectively classified as negative (normal/benign) or positive (suspicious/malignant) by two radiologists, blinded to marnmographic and histologic results with both the conventional and high-resolution. All lesions were confirmed by pathology. Results: Included in this study were 30 benign and 28 malignant lesions. The sensitivity for detection of breast cancer was 64.3% (18/28) with the conventional camera and 78.6% (22/28) with the HRBGC. Specificity of both systems was 93.3% (28/30). In the 18 nonpalpable cancers, sensitivity was 55.5% (10/18) and 72.2% (13/18) with the generalpurpose camera and HRBGC, respectively. In cancers less than or equal to 1cm, 7 of 15 were detected with the general-purpose camera and 10 of 15 with the HRBGC. Four of the cancers (median size, 8.5 mm) detected with the HRBGC were missed by the conventional camera. Conclusion: Evaluation of indeterminate breasts lesions with a high resolution, breast-specific gamma camera results in improved sensitivity for the detection of cancer with greater improvement demonstrated in nonpalpable and less than or equal to 1 cm cancers. (C) 2002 Elsevier Science B.V. All rights reserved. C1 George Washington Univ, Med Ctr, Breast Imaging & Intervent Ctr, Washington, DC 20037 USA. Hampton Univ, Hampton, VA 23668 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Brem, RF (reprint author), George Washington Univ, Med Ctr, Breast Imaging & Intervent Ctr, 2150 Penn Ave, Washington, DC 20037 USA. NR 20 TC 10 Z9 10 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 2003 VL 497 IS 1 BP 39 EP 45 AR PII S0168-9002(02)01890-9 DI 10.1016/S0168-9002(02)01890-9 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 644CR UT WOS:000180900800008 ER PT J AU Moses, WW Qi, J AF Moses, WW Qi, J TI Fundamental limits of positron emission mammography SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st Topical Symposium on Functional Breast Imaging with Advanced Detectors CY APR 18-21, 2001 CL ROME, ITALY DE positron emission mammography; positron emission tomography; nuclear medicine instrumentation; focal plane tomography; iterative reconstruction; breast cancer ID BREAST-CANCER; PET DETECTOR; FIBERS AB We explore the causes of performance limitation in positron emission mammography cameras. We compare two basic camera geometries containing the same volume of 511 keV photon detectors, one with a parallel plane geometry and another with a rectangular geometry. We find that both geometries have similar performance for the phantom imaged (in Monte Carlo simulation), even though the solid angle coverage of the rectangular camera is about 50% higher than the parallel plane camera. The reconstruction algorithm used significantly affects the resulting image; iterative methods significantly outperform the commonly used focal plane tomography. Finally, the characteristics of the tumor itself, specifically the absolute amount of radiotracer taken up by the tumor, will significantly affect the imaging performance. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Moses, WW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,Mail Stop 55-121, Berkeley, CA 94720 USA. RI Qi, Jinyi/A-1768-2010 OI Qi, Jinyi/0000-0002-5428-0322 NR 19 TC 20 Z9 20 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2003 VL 497 IS 1 BP 82 EP 89 AR PII S0168-9002(02)01895-8 DI 10.1016/S0168-9002(02)01895-8 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 644CR UT WOS:000180900800013 ER PT J AU Kieper, D Green, TD Hoefer, R Keppel, C Wymer, DC Weisenberger, AG Welch, B AF Kieper, D Green, TD Hoefer, R Keppel, C Wymer, DC Weisenberger, AG Welch, B TI Data analysis methods for a small field-of-view combined scintimammography/digital X-ray system in breast lesion management SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st Topical Symposium on Functional Breast Imaging with Advanced Detectors CY APR 18-21, 2001 CL ROME, ITALY DE scintimammography; pixellated scintillator; position sensitive photomultiplier ID PRONE SCINTIMAMMOGRAPHY; TC-99M SESTAMIBI; DETECTOR; DIAGNOSIS; CARCINOMA; CANCER; PSPMT AB Recently, a multidisciplinary research collaboration began a clinical study employing a dual modality, small field-of-view breast imaging system. The system, comprised of a mini gamma camera and digital X-ray detector, was designed to examine the possible clinical advantages of dual modality breast imaging in the management of patients with suspicious findings (BIRADS 3-5) from a screening mammogram. In addition, dynamic time-resolution studies of radiotracer uptake and washout were evaluated for their value in differentiation of lesion type. This preliminary report focuses on the development and implementation of these techniques and presents patient data as evidence of their effectiveness. The results of this study indicate that applying these techniques may significantly improve the diagnostic value of scintimammography by increasing specificity to 97.7% by differentiation of true positive and false positive lesions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Thomas Jefferson Natl Accelerator Facil, Dept Phys, Newport News, VA 23606 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Oyster Point Surg Associates, Newport News, VA USA. Riverside Diagnost & Imaging Ctr, Newport News, VA USA. RP Kieper, D (reprint author), Thomas Jefferson Natl Accelerator Facil, Dept Phys, Newport News, VA 23606 USA. NR 12 TC 1 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2003 VL 497 IS 1 BP 135 EP 140 DI 10.1016/S0168-9002(02)01903-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 644CR UT WOS:000180900800021 ER PT J AU Giokaris, ND Loudos, GK Maintas, D Papapanagiotou, D Nikita, KS Uzunoglu, NK Karabarbounis, A Papanicolas, CN Stillaris, E Archimandritis, SC Varvarigou, AD Stefanis, CN Majewski, S Weisen-berger, A Pani, R Scopinaro, F AF Giokaris, ND Loudos, GK Maintas, D Papapanagiotou, D Nikita, KS Uzunoglu, NK Karabarbounis, A Papanicolas, CN Stillaris, E Archimandritis, SC Varvarigou, AD Stefanis, CN Majewski, S Weisen-berger, A Pani, R Scopinaro, F TI Imaging of breast phantoms using a high-resolution position sensitive photomultiplier tube SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st Topical Symposium on Functional Breast Imaging with Advanced Detectors CY APR 18-21, 2001 CL ROME, ITALY DE PSPMT; breast phantoms; high resolution; sensitivity; maximum likelihood; "hot" spot AB The results of studies conducted with a small field of view gamma camera based on a Position Sensitive Photomultiplier Tube (PSPMT) and a pixelized scintillator crystal, made of CsI(TI), are reported. Using a computer-controlled step motor allowing object rotation, projection data from several angles are acquired. Images of slices of the object are obtained and compared with the use of a Filtered Backprojection and a Maximum Likelihood algorithm. Phantom studies have shown a spatial resolution of 2-3 mm in both two and three dimensions, and mice experiments have shown successful SPECT imaging of small organs. 31) images obtained from a paraffin cylinder phantom and from a Tc-99m water solution phantom showed that a "hot" spot with a size down to 0.2ml can be detected with a resolution of about 2 mm if the tumor to background activity ratio is 6: 1. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Inst Accelerating Syst & Applicat, Athens 10024, Greece. Natl Tech Univ Athens, GR-15773 Athens, Greece. Natl Capodistrian Univ Athens, Athens 10679, Greece. Natl Ctr Sci Res Demokritos, Athens 15310, Greece. Athens Med Ctr, Inst Isotop Studies, Athens 15125, Greece. Univ Athens, Mental Hlth Res Inst, Athens 11521, Greece. Jefferson Lab, Newport News, VA USA. Univ Roma La Sapienza, Rome, Italy. RP Giokaris, ND (reprint author), Inst Accelerating Syst & Applicat, POB 17214, Athens 10024, Greece. OI Scopinaro, Francesco/0000-0003-1924-3005 NR 12 TC 14 Z9 14 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 2003 VL 497 IS 1 BP 141 EP 149 AR PII S0168-9002(02)01904-6 DI 10.1016/S0168-9002(02)01904-6 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 644CR UT WOS:000180900800022 ER PT J AU Kieper, D Majewski, S Kross, B Popov, V Weisenberger, AG Welch, B Wojcik, R Williams, MB Goode, AR More, M Zhang, G AF Kieper, D Majewski, S Kross, B Popov, V Weisenberger, AG Welch, B Wojcik, R Williams, MB Goode, AR More, M Zhang, G TI Optimization of breast imaging procedure with dedicated compact gamma cameras SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st Topical Symposium on Functional Breast Imaging with Advanced Detectors CY APR 18-21, 2001 CL ROME, ITALY DE pixellated scintillator; scintimammography; gamma camera AB Results are presented on studies conducted with various prototypes of a dedicated small field-of-view (SFOV) gamma camera for use in radiopharmaceutical studies of the breast. Since the experience in the clinical use of such instruments is limited, these experiments were conducted to test various clinical imaging implementations. Both planar and tomographic techniques were utilized to image various compressed and noncompressed breast phantoms. Lesion contrast was used to quantify the lesion visibility of each case. The results of this study indicate that lesion contrast is optimized with planar imaging of the compressed breast and that contrast is also dependent on lesion-to-detector distance. Based on these observations, planar imaging conducted with a system comprised of two opposed detectors providing compression to the breast would be optimal. The opposed views would ensure the minimization of lesion-to-detector distance, especially for lesions whose location is not known a-priori. Published by Elsevier Science B.V. C1 Thomas Jefferson Natl Accelerator Facil, Dept Phys, Newport News, VA 23606 USA. Univ Virginia, Dept Radiol, Charlottesville, VA 22908 USA. RP Kieper, D (reprint author), Thomas Jefferson Natl Accelerator Facil, Dept Phys, Newport News, VA 23606 USA. NR 3 TC 12 Z9 12 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 2003 VL 497 IS 1 BP 168 EP 173 AR PII S0168-9002(02)01907-1 DI 10.1016/S0168-9002(02)01907-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 644CR UT WOS:000180900800025 ER PT J AU Mourant, JR Gibson, RR Johnson, TM Carpenter, S Short, KW Yamada, YR Freyer, JP AF Mourant, JR Gibson, RR Johnson, TM Carpenter, S Short, KW Yamada, YR Freyer, JP TI Methods for measuring the infrared spectra of biological cells SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID MAJOR CELLULAR-COMPONENTS; ATOMIC-FORCE MICROSCOPY; LASER RAMAN; SPECTROSCOPY; PROTEINS; CYCLE; IR; CONFORMATION; FIBROBLASTS; MORPHOLOGY AB Infrared (IR) spectroscopy of biological cells is a growing area of research, with many papers focusing on differences between the spectra of cancerous and noncancerous cells. Much of this research has been performed using a monolayer of dehydrated cells. We posit that the use of monolayers can introduce artefacts that lead to an apparent but inaccurate measurement of differences between cancerous and noncancerous cells. Additionally, the use of dried cells complicates the extraction of biochemical information from the IR spectra. We demonstrate that using suspensions of viable cells in aqueous suspension reduces measurement artefacts and facilitates determining the concentration of the major biochemical components via a linear least-squares fit of the component spectra to the spectrum of the cells. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Mourant, JR (reprint author), Los Alamos Natl Lab, Biosci Div, MS E535, Los Alamos, NM 87545 USA. NR 29 TC 54 Z9 54 U1 2 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD JAN 21 PY 2003 VL 48 IS 2 BP 243 EP 257 AR PII S0031-9155(03)39902-6 DI 10.1088/0031-9155/48/2/307 PG 15 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 647ZZ UT WOS:000181125100007 PM 12587907 ER PT J AU Yang, JK Park, MS Waldo, GS Suh, SW AF Yang, JK Park, MS Waldo, GS Suh, SW TI Directed evolution approach to a structural genomics project: Rv2002 from Mycobacterium tuberculosis SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SHORT-CHAIN DEHYDROGENASES; CRYSTAL-STRUCTURE; 3-ALPHA,20-BETA-HYDROXYSTEROID DEHYDROGENASE; 17-BETA-HYDROXYSTEROID DEHYDROGENASE; ALCOHOL-DEHYDROGENASE; CATALYTIC DOMAIN; REDUCTASE; PROTEIN; FAMILY; IDENTIFICATION AB One of the serious bottlenecks in structural genomics projects is overexpression of the target proteins in soluble form. We have applied the directed evolution technique and prepared soluble mutants of the Mycobacterium tuberculosis Rv2002 gene product, the wild type of which had been expressed as inclusion bodies in Escherichia coli. A triple mutant 16T/V47M/T69K (Rv2002-M3) was chosen for structural and functional characterizations. Enzymatic assays indicate that the Rv2002-M3 protein has a high catalytic activity as a NADH-dependent 3alpha, 20beta-hydroxysteroid dehydrogenase. We have determined the crystal structures of a binary complex with NAD(+) and a ternary complex with androsterone and NADH. The structure reveals that Asp-38 determines the cofactor specificity. The catalytic site includes the triad Ser-140/Tyr-153/Lys-157. Additionally, it has an unusual feature, Glu-142. Enzymatic assays of the E142A mutant of Rv2002-M3 indicate that Glu-142 reverses the effect of Lys-157 in influencing the pKa of Tyr-153. This study suggests that the Rv2002 gene product is a unique member of the SDR family and is likely to be involved in steroid metabolism in M. tuberculosis. Our work demonstrates the power of the directed evolution technique as a general way of overcoming the difficulties in overexpressing the target proteins in soluble form. C1 Seoul Natl Univ, Sch Chem & Mol Engn, Struct Proteom Lab, Seoul 151742, South Korea. Los Alamos Natl Lab, Div Biosci, Los Alamos, NM 87545 USA. RP Suh, SW (reprint author), Seoul Natl Univ, Sch Chem & Mol Engn, Struct Proteom Lab, Seoul 151742, South Korea. RI Suh, Se Won/H-8306-2013 OI Suh, Se Won/0000-0002-1768-4635 NR 35 TC 35 Z9 40 U1 0 U2 4 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 21 PY 2003 VL 100 IS 2 BP 455 EP 460 DI 10.1073/phas.0137017100 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 638UE UT WOS:000180589000015 PM 12524453 ER PT J AU Berdahl, P Reade, RP Liu, JP Russo, RE Fritzemeier, L Buczek, D Schoop, U AF Berdahl, P Reade, RP Liu, JP Russo, RE Fritzemeier, L Buczek, D Schoop, U TI Oblique ion texturing of yttria-stabilized zirconia: the {211}< 111 > structure SO APPLIED PHYSICS LETTERS LA English DT Article ID BEAM-ASSISTED DEPOSITION; SINGLE-CRYSTAL; THIN-FILMS; ORIENTATION; CRYSTALLIZATION; BOMBARDMENT; METAL AB Amorphous (Zr,Y)O-x films were synthesized by reactive magnetron sputtering and subsequently crystallized by oblique ion bombardment. Crystalline texture nucleated by the ion beam was replicated by solid-phase epitaxial growth throughout the formerly amorphous yttria-stabilized zirconia (YSZ) film. The resulting YSZ films have (211) orientation normal to the substrate with in-plane directions (111), parallel, and (110), transverse, to the azimuth of the ion beam. We hypothesize that the texture mechanism involves ion-induced film compression and shear. The results, taken together with prior work, show that oblique ion texturing of amorphous films is a general phenomenon that can be used to fabricate substrates with more than one type of crystallographic orientation. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Amer Supercond Corp, Westborough, MA 01581 USA. RP Berdahl, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Liu, Jinping/B-2305-2010 NR 23 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 20 PY 2003 VL 82 IS 3 BP 343 EP 345 DI 10.1063/1.1536266 PG 3 WC Physics, Applied SC Physics GA 636HT UT WOS:000180449100011 ER PT J AU Lomascolo, M Creti, A Leo, G Vasanelli, L Manna, L AF Lomascolo, M Creti, A Leo, G Vasanelli, L Manna, L TI Exciton relaxation processes in colloidal core/shell ZnSe/ZnS nanocrystals SO APPLIED PHYSICS LETTERS LA English DT Article ID CDSE QUANTUM DOTS; SEMICONDUCTOR NANOCRYSTALS; GROWTH AB Colloidal ZnSe nanocrystals are coated with a ZnS shell and are investigated by means of time-resolved photoluminescence spectroscopy. These nanocrystals are stable against photooxidation and have photoluminescence quantum efficiencies around 15% even months after the synthesis. Recombination processes are investigated as a function of the excitation intensity and the emission energy. Nonlinear processes such as Auger recombination dominate in the early times after the photogeneration of electron-hole pairs. The lifetime of single exciton states is shorter in smaller ZnSe dots than in larger ones, in accordance with theoretical predictions and as previously observed on similar systems. (C) 2003 American Institute of Physics. C1 IMM CNR, Ist Microelettr & Microsistemi Lecce, I-73100 Lecce, Italy. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Lecce, Inst Adv Interdisciplinary Studies ISUFI, I-73100 Lecce, Italy. Univ Lecce, Dipartimento Ingn Innovaz, I-73100 Lecce, Italy. RP Lomascolo, M (reprint author), IMM CNR, Ist Microelettr & Microsistemi Lecce, Via Arnesano, I-73100 Lecce, Italy. RI Manna, Liberato/G-2339-2010; OI Manna, Liberato/0000-0003-4386-7985; LEO, GABRIELLA/0000-0001-8871-7556; LOMASCOLO, MAURO/0000-0002-2851-8552 NR 19 TC 34 Z9 35 U1 3 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 20 PY 2003 VL 82 IS 3 BP 418 EP 420 DI 10.1063/1.1537050 PG 3 WC Physics, Applied SC Physics GA 636HT UT WOS:000180449100036 ER PT J AU Skidmore, JT Gildemeister, J Lee, AT Myers, MJ Richards, PL AF Skidmore, JT Gildemeister, J Lee, AT Myers, MJ Richards, PL TI Superconducting bolometer for far-infrared Fourier transform spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID STRONG ELECTROTHERMAL FEEDBACK AB A voltage-biased superconducting bolometer with a heat sink temperature of 4.2 K has been developed for Fourier transform spectroscopy in the far infrared. This device is based on a Nb transition edge sensor with T-c=8.1 K. It will operate for absorbed infrared power up to 3x10(-6) W and has an absorber area of 7 mm2. The response is inherently linear and the noise equivalent power (NEP)=1.2x10(-13) W Hz(-1/2) is dominated by thermal fluctuation noise. This NEP is at least a factor 10 better than that expected for a conventional 4.2 K semiconductor bolometer which is optimized for 1% saturation at the same infrared power. The optical response time tau=1.2 ms is dominated by the internal thermalization time. A smaller version of this bolometer could be useful for diffraction-limited spectroscopy of small samples throughout the infrared. Estimates suggest that values of detectivity D*>10(11) cm Hz+1/2 W-1 and time constants approaching 270 mus could be achieved. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. RP Skidmore, JT (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 6 TC 9 Z9 9 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 20 PY 2003 VL 82 IS 3 BP 469 EP 471 DI 10.1063/1.1538348 PG 3 WC Physics, Applied SC Physics GA 636HT UT WOS:000180449100053 ER PT J AU Klein, RI Budil, KS Perry, TS Bach, DR AF Klein, RI Budil, KS Perry, TS Bach, DR TI The interaction of supernova remnants with interstellar clouds: Experiments on the Nova laser SO ASTROPHYSICAL JOURNAL LA English DT Article DE instabilities; ISM : clouds; methods : laboratory; shock waves; supernova remnants ID GAS CLOUDS; INSTABILITY; WAVES AB The interaction of strong shock waves, such as those generated by the explosion of supernovae with interstellar clouds, is a problem of fundamental importance in understanding the evolution and the dynamics of the interstellar medium (ISM) as it is disrupted by shock waves. Here we present the results of a series of scaled Nova laser high energy density experiments investigating the evolution of a high-density sphere embedded in a low-density medium after the passage of a strong shock wave, thereby emulating the supernova shock-cloud interaction. The Nova laser was utilized to generate a strong (similar toMach 10) shock wave that traveled along a miniature beryllium shock tube, 750 mum in diameter, filled with a low-density plastic emulating the ISM. Embedded in the plastic was a copper microsphere (100 mum in diameter), emulating the interstellar cloud. The morphology and evolution as well as the shock wave trajectory were diagnosed via side-on X-ray radiography. We describe here experimental X-ray radiographic results of this interaction out to several cloud crushing times and compare them to detailed two- and three-dimensional radiation hydrodynamic simulations using both arbitrary Lagrangian and Eulerian hydrodynamics (ALE), as well as high-resolution adaptive mesh refinement (AMR) hydrodynamics. A key result is the first experimental evidence that the cloud is destroyed by a three-dimensional nonlinear bending-mode instability (Widnall instability), confirming earlier predictions with high-resolution three-dimensional calculations. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Klein, RI (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. RI Perry, Theodore/K-3333-2014 OI Perry, Theodore/0000-0002-8832-2033 NR 15 TC 57 Z9 57 U1 0 U2 3 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 2003 VL 583 IS 1 BP 245 EP 259 DI 10.1086/345340 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634NJ UT WOS:000180346800019 ER PT J AU Mullan, DJ Smith, CW Ness, NF Skoug, RM AF Mullan, DJ Smith, CW Ness, NF Skoug, RM TI Short-period magnetic fluctuations in Advanced Composition Explorer solar wind data: Evidence for anticorrelation with Alfven speed SO ASTROPHYSICAL JOURNAL LA English DT Article DE interplanetary medium; MHD; solar wind ID DISSIPATION AB Short-period rms uctuations deltaB(rms) in the interplanetary magnetic field have been derived from Advanced Composition Explorer/MAG data for 50 solar rotations between 1998 and 2001. We find that in many cases, individual maxima in deltaB(rms) are associated with local minima in the Alfven speed V-Alf. To determine whether this anticorrelation persists in large data sets, we compute the correlation coefficient between the temporal gradients (in the spacecraft frame) delta(B) over dot(rms) and (V) over dot(Alf) for each of the 50 solar rotations in the data set. We find that, in 48 of the 50 rotations, delta(B) over dot(rms) is anticorrelated with (V) over dot(Alf). The confidence level of the anticorrelation is greater than 90% in 35 rotations and is greater than 99.95% in 14 rotations. We find that in some low-V-Alf regions of solar wind, there is a pronounced enhancement of non-Alfvenic (compressive) fluctuations. We suggest that refraction effects operating on MHD waves contribute to these aspects of the magnetic field fluctuation properties of the solar wind. C1 Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mullan, DJ (reprint author), Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. NR 12 TC 11 Z9 11 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 2003 VL 583 IS 1 BP 496 EP 505 DI 10.1086/345353 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634NJ UT WOS:000180346800044 ER PT J AU Torres, DF Nuza, SE AF Torres, DF Nuza, SE TI Possible new gamma-ray pulsar detections by the AGILE and GLAST missions: An outer gap model look at the Parkes pulsar catalog SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; gamma rays : theory; pulsars : general ID UNIDENTIFIED EGRET SOURCES; SUPERNOVA REMNANT; DISCOVERY AB The predictive power of the outer gap model of high-energy emission from pulsars is used to analyze the Parkes multibeam pulsar survey. We find that most of the radio pulsars of the Parkes catalog are not gamma-ray emitters according to the outer gap model. The sample of possible new gamma-ray pulsar detections by AGILE and GLAST is given. That includes 13 new excellent candidates. Four new positional coincidences between EGRET detections and Parkes pulsars are found, for which we discard a physical association. The consequences of applying a new electron density model for assigning the pulsar distances are explored. The new model systematically reduces the distances to the pulsars (corrections can be as large as 90%), increasing their fluxes and affecting the detection prospects. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Fis Juan Jose Giambiagi, RA-1428 Buenos Aires, DF, Argentina. RP Torres, DF (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,L-413, Livermore, CA 94550 USA. RI Torres, Diego/O-9422-2016 OI Torres, Diego/0000-0002-1522-9065 NR 23 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 2003 VL 583 IS 1 BP L25 EP L29 DI 10.1086/367815 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634NL UT WOS:000180347000007 ER PT J AU MacKinnon, RJ Carey, GF AF MacKinnon, RJ Carey, GF TI Positivity-preserving, flux-limited finite-difference and finite-element methods for reactive transport SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE convection-diffusion-reaction equation; positivity preserving; total variation diminishing; upwinding; Petrov-Galerkin method; finite-difference method ID HIGH-RESOLUTION SCHEMES; HYPERBOLIC CONSERVATION-LAWS; FLOW; COMPUTATION; SIMULATION; GRIDS AB A new class of positivity-preserving, flux-limited finite-difference and Petrov-Galerkin (PG) finite-element methods are devised for reactive transport problems. The methods are similar to classical TVD flux-limited schemes with the main difference being that the flux-limiter constraint is designed to preserve positivity for problems involving diffusion and reaction. In the finite-element formulation, we also consider the effect of numerical quadrature in the lumped and consistent mass matrix forms on the positivity-preserving property. Analysis of the latter scheme shows that positivity-preserving solutions of the resulting difference equations can only be guaranteed if the flux-limited scheme is both implicit and satisfies an additional lower-bound condition on time-step size. We show that this condition also applies to standard Galerkin linear finite-element approximations to the linear diffusion equation. Numerical experiments are provided to demonstrate the behavior of the methods and confirm the theoretical conditions on time-step size, mesh spacing, and flux limiting for transport problems with and without nonlinear reaction. (C) Copyright 2003 John Wiley Sons, Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Texas, Coll Engn, Austin, TX 78712 USA. RP MacKinnon, RJ (reprint author), Sandia Natl Labs, POB 5800,MS 0778, Albuquerque, NM 87123 USA. NR 27 TC 13 Z9 13 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JAN 20 PY 2003 VL 41 IS 2 BP 151 EP 183 DI 10.1002/fld.433 PG 33 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 635QL UT WOS:000180410300003 ER PT J AU Rice, JP Bender, SC Atkins, WH Lovas, FJ AF Rice, JP Bender, SC Atkins, WH Lovas, FJ TI Deployment test of the NIST EOS thermal-infrared transfer radiometer SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article; Proceedings Paper CT Conference on Characterization and Radiometric Calibration fo Remote Sensing CY NOV 09-11, 1999 CL UTAH STATE UNIV, LOGAN, UTAH HO UTAH STATE UNIV ID CALIBRATION AB The National Institute of Standards and Technology (NIST) Thermal-infrared Transfer Radiometer (TXR), developed for the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS), was deployed at the remote sensing radiometric calibration facility at Los Alamos National Laboratory (LANL). The purpose of the deployment was to test the ability of the TXR to operate off-site of NIST in a host cryogenic vacuum chamber, and to provide an end-to-end verification of the radiance scale in the LANL facility. The TXR was calibrated pre-trip and post-trip at NIST against a water bath black body in ambient conditions. At LANL, the TXR was operated in a liquid nitrogen cooled vacuum chamber, mounted in the same position that remote sensing instruments occupy during their pre-flight calibrations. The results from the TXR 5 mum channel show that the LANL radiance scale agrees with that of the NIST water bath black body to within a radiance uncertainty of +/-0.16% (k = 2). This corresponds to a brightness temperature uncertainty of 50 mK (k = 2) at 300 K. Thus, the TXR has demonstrated its ability to provide an economical end-to-end system-level verification of the component-level radiometric scale assigned to a calibration facility. Such verifications provide an extra level of confidence in the radiometric accuracy of flight instrument calibration facilities that has hitherto not been possible. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rice, JP (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 5 TC 15 Z9 18 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN 20 PY 2003 VL 24 IS 2 BP 367 EP 388 DI 10.1080/01431160110113197 PG 22 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 640YV UT WOS:000180717400014 ER PT J AU Agarwal, H Gokhale, AM Graham, S Horstemeyer, MF AF Agarwal, H Gokhale, AM Graham, S Horstemeyer, MF TI Void growth in 6061-aluminum alloy under triaxial stress state SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE void growth; damage; aluminum alloys; image analysis; quantitative metallography ID NUCLEATION AB In numerous metals and alloys, ductile fracture involves void nucleation, growth, and coalescence. In this contribution, void growth has been quantitatively characterized in an extruded 6061-wrought Al-alloy as a function of stress state in notch tensile test specimens. Digital image analysis and Stereology have been used to estimate the volume fraction and three-dimensional number density of voids in a series of interrupted notch tensile test specimens where the local stress state is predominantly triaxial. Finite elements (FE) simulations have been used to compute the stress states at different locations in the specimens. The computed stress states and experimentally estimated average void volume are utilized to verify analytical void growth models. Lack of agreement between the predictions of the models and the experimental data is due to interactions between neighboring voids, which are ignored in the theoretical models, and continuous void nucleation. The following empirical damage evolution equation is obtained from the experimental data on void volume fraction expressed as % (f), and the corresponding local equivalent plastic strain (6,) and stress triaxiality (I) computed from FE simulations: f = a + b ln[epsilon(p)] + cI. In this equation, a, b and c are empirical constants whose values depend on the alloy chemistry, heat treatment, and microstructure. The equation is useful only for 6061(T6) Al-alloy. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Sandia Natl Labs, Livermore, CA USA. RP Gokhale, AM (reprint author), Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. OI Horstemeyer, Mark/0000-0003-4230-0063 NR 12 TC 53 Z9 61 U1 1 U2 15 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 20 PY 2003 VL 341 IS 1-2 BP 35 EP 42 AR PII S0921-5093(02)00073-4 DI 10.1016/S0921-5093(02)00073-4 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 618GH UT WOS:000179410000004 ER PT J AU Goretta, KC Gutierrez-Mora, F Picciolo, JJ Routbort, JL AF Goretta, KC Gutierrez-Mora, F Picciolo, JJ Routbort, JL TI Joining alumina/zirconia ceramics SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE ZrO2; superplastic; Al2O3 ID SUPERPLASTIC DEFORMATION MECHANISMS; STABILIZED ZIRCONIA POLYCRYSTALS; ALUMINA CERAMICS; CREEP; FLOW; FABRICATION; INTERLAYER AB Dense compacts consisting of 40 vol.% Al-103-60 vol.% 3 mol% Y2O3-stabilized ZrO2 (YSZ) were joined with an interlayer of 50 vol.% Al2O3-50 vol.% YSZ. A joint was also made at 1200 degreesC with an interlayer that was 50 vol.% Al2O3-50 vol.% ZrO2, in which the average particle size of both powders was less than or equal to20 nm. The joint materials were applied by aerosol spraying, and thus the technique is suitable for commercial application. Superplastic deformation at 1200-1350 degreesC required less than or equal to2 h to form fully dense joints in which minimal grain growth occurred. Virtually perfect joints were also made with various other ratios of Al2O3-YSZ. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Routbort, JL (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Gutierrez-Mora, Felipe/H-4625-2015 OI Gutierrez-Mora, Felipe/0000-0003-3632-7163 NR 22 TC 22 Z9 22 U1 0 U2 9 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 20 PY 2003 VL 341 IS 1-2 BP 158 EP 162 AR PII S0921-5093(02)00212-5 DI 10.1016/S0921-5093(02)00212-5 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 618GH UT WOS:000179410000018 ER PT J AU Hurwitz, S Goff, F Janik, CJ Evans, WC Counce, DA Sorey, ML Ingebritsen, SE AF Hurwitz, S Goff, F Janik, CJ Evans, WC Counce, DA Sorey, ML Ingebritsen, SE TI Mixing of magmatic volatiles with groundwater and interaction with basalt on the summit of Kilauea Volcano, Hawaii SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article DE Kilauea Volcano; magmatic volatiles; groundwater chemistry; water-rock interaction; hydrothermal system; mass transport ID MOUNT ST-HELENS; EAST RIFT-ZONE; HYDROTHERMAL SYSTEM; VELOCITY STRUCTURE; CARBON-DIOXIDE; LOOWIT CANYON; WATERS; USA; HYDROGEN; TRITIUM AB [1] We interpret new chemical and isotopic data from samples collected between October 1998 and March 2002 from the NSF well ( also called the Keller well), the only deep well on the summit of Kilauea Volcano, Hawaii. Sample collection followed cleaning of the well, which renewed access to the hydrothermal system very close to the loci of magmatic and fumarolic activity. The chemical and isotopic compositions of the new samples differ remarkably from data published previously. On the basis of the S/Cl ratio and carbon and helium isotopes we conclude that the thermal fluids formed by condensation of magmatic gas into shallow meteoric groundwater. Gas condensation was followed by a complex pattern of basalt dissolution accompanied by an increase of fluid pH and precipitation of secondary minerals. Geochemical modeling and geothermometry imply that the fluids equilibrated with an assemblage of secondary minerals at temperatures between 90 and 140 degreesC. The significantly different chemical composition of the NSF well fluids from that of springs along the southern coast of the island indicates that mass transport from the summit region toward the lower flanks of the volcano is limited. C1 US Geol Survey, Menlo Pk, CA 94025 USA. Los Alamos Natl Lab, Geol Geochem Grp, Los Alamos, NM 87545 USA. RP Hurwitz, S (reprint author), US Geol Survey, 345 Middlefield Rd, Menlo Pk, CA 94025 USA. EM shaul@usgs.gov RI Evans, William/J-4283-2012 NR 75 TC 9 Z9 9 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 18 PY 2003 VL 108 IS B1 AR 2028 DI 10.1029/2001JB001594 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 659WE UT WOS:000181799800005 ER PT J AU Rigden, DJ Littlejohn, JE Henderson, K Jedrzejas, MJ AF Rigden, DJ Littlejohn, JE Henderson, K Jedrzejas, MJ TI Structures of phosphate and trivanadate complexes of Bacillus stearothermophilus phosphatase PhoE: Structural and functional analysis in the cofactor-dependent phosphoglycerate mutase superfamily SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE catalysis; Gram-positive bacteria; mechanism of action; phosphohistidine intermediate; X-ray ID CRYSTAL-STRUCTURE; ACID-PHOSPHATASE; ANGSTROM RESOLUTION; PROTEIN STRUCTURES; FRUCTOSE-2,6-BISPHOSPHATASE; CRYSTALLOGRAPHY; EVOLUTION; MECHANISM; ENZYME; DOMAIN AB Bacillus stearothermophilus phosphatase PhoE is a member of the cofactor-dependent phosphoglycerate mutase superfamily possessing broad specificity phosphatase activity. Its previous structural determination in complex with glycerol revealed probable bases for its efficient hydrolysis of both large, hydrophobic, and smaller, hydrophilic substrates. Here we report two further structures of PhoE complexes, to higher resolution of diffraction, which yield a better and thorough understanding of its catalytic mechanism. The environment of the phosphate ion in the catalytic site of the first complex strongly suggests an acid-base catalytic function for Glu83. It also reveals how the C-terminal tail ordering is linked to enzyme activation on phosphate binding by a different mechanism to that seen in Escherichia coli phosphoglycerate mutase. The second complex structure with an unusual doubly covalently bound trivanadate shows how covalent modification of the phosphorylable His10 is accompanied by small structural changes, presumably to catalytic advantage. When compared with structures of related proteins in the cofactor-dependent phosphoglycerate mutase superfamily, an additional phosphate ligand, Gln22, is observed in PhoE. Functional constraints lead to the corresponding residue being conserved as Gly in fructose-2,6-bisphosphatases and Thr/Ser/Cys in phosphoglycerate mutases. A number of sequence annotation errors in databases are highlighted by this analysis. B. stearothermophilus PhoE is evolutionarily related to a group of enzymes primarily present in Gram-positive bacilli. Even within this group substrate specificity is clearly variable highlighting the difficulties of computational functional annotation in the cofactor-dependent phosphoglycerate mutase superfamily. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Childrens Hosp Oakland Res Inst, Oakland, CA 94609 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley Ctr Struct Biol, Berkeley, CA 94720 USA. SAIN, EMBRAPA, Cenargen, Natl Ctr Genet Resources & Biotechnol, BR-70770900 Brasilia, DF, Brazil. RP Jedrzejas, MJ (reprint author), Childrens Hosp Oakland Res Inst, 5700 Martin Luther King Jr Way, Oakland, CA 94609 USA. OI Rigden, Daniel/0000-0002-7565-8937 FU NIAID NIH HHS [AI 44079] NR 40 TC 21 Z9 21 U1 0 U2 3 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JAN 17 PY 2003 VL 325 IS 3 BP 411 EP 420 DI 10.1016/S0022-2836(02)01229-9 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 637ZZ UT WOS:000180544700001 PM 12498792 ER PT J AU Opalka, N Beckmann, R Boisset, N Simon, MN Russel, M Darst, SA AF Opalka, N Beckmann, R Boisset, N Simon, MN Russel, M Darst, SA TI Structure of the filamentous phage pIV multimer by cryo-electron microscopy SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE membrane protein; filamentous phage; secretin; pIV; cryo-electron microscopy ID GENERAL SECRETORY PATHWAY; BACTERIAL-CELL ENVELOPE; ESCHERICHIA-COLI; OUTER-MEMBRANE; 3-DIMENSIONAL RECONSTRUCTION; CRYSTAL-STRUCTURE; PROTEIN; EXPORT; FORMS; TRANS AB The homo-multimeric pIV protein constitutes a channel required for the assembly and export of filamentous phage across the outer membrane of Escherichia coli. We present a 22 A-resolution three-dimensional reconstruction of detergent-solubilized pIV by cryo-electron microscopy associated with image analysis. The structure reveals a barrel-like complex, 13.5 nm in diameter and 24 nm in length, with D14 point-group symmetry, consisting of a dimer of unit multimers. Side views of each unit multimer exhibit three cylindrical domains named the N-ring, the M-ring and the C-ring. Gold labeling of pIV engineered to contain a single cysteine residue near the N or C terminus unambiguously identified the N-terminal region as the N-ring, and the C-terminal region was inferred to make up the C-ring. A large pore, ranging in inner diameter from 6.0 nm to 8.8 nm, runs through the middle of the multimer, but a central domain, the pore gate, blocks it. Moreover, the pore diameter at the N-ring is smaller than the phage particle. We therefore propose that the pIV multimer undergoes a large conformational change during phage transport, with reorganization of the central domain to open the pore, and widening at the N-ring in order to accommodate the 6.5 nm diameter phage particle. (C) 2003 Elsevier Science Ltd. All rights reserved C1 Rockefeller Univ, New York, NY 10021 USA. Humboldt Univ, Inst Biochem, Charite, D-10117 Berlin, Germany. Univ Paris 06, CNRS, Lab Mineral Cristallog Paris, UMR 7590, F-75252 Paris, France. Univ Paris 07, CNRS, Lab Mineral Cristallog Paris, UMR 7590, F-75252 Paris 05, France. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Darst, SA (reprint author), Rockefeller Univ, 1230 York Ave, New York, NY 10021 USA. FU NCRR NIH HHS [P41-RR01777] NR 42 TC 78 Z9 81 U1 1 U2 10 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JAN 17 PY 2003 VL 325 IS 3 BP 461 EP 470 DI 10.1016/S0022-2836(02)01246-9 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 637ZZ UT WOS:000180544700005 PM 12498796 ER PT J AU Viola, L Onofrio, R AF Viola, L Onofrio, R TI Contractive Schrodinger cat states for a free mass SO NEW JOURNAL OF PHYSICS LA English DT Article ID STANDARD QUANTUM LIMIT; SUPERPOSITION STATES; RADIATION-PRESSURE; NOISE REDUCTION; DECOHERENCE; ENTANGLEMENT; OSCILLATOR; MIRROR; CAVITY; ENVIRONMENT AB Contractive states for a free quantum particle were introduced by Yuen (Yuen H P 1983 Phys. Rev. Lett. 51 719) in an attempt to evade the standard quantum limit for repeated position measurements. We show how appropriate families of two- and three-component 'Schrodinger cat states' are able to support non-trivial correlations between the position and momentum observables leading to contractive behaviour. The existence of contractive Schrodinger cat states is suggestive of potential novel roles of non-classical states for precision measurement schemes. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Padua, Dipartimento Fis G Galilei, I-35131 Padua, Italy. Ist Nazl Fis Mat, Unita Roma La Sapienza, I-00185 Rome, Italy. Ctr Stat Mech & Complex, I-00185 Rome, Italy. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM lviola@lanl.gov; onofrio@pd.infn.it NR 73 TC 5 Z9 5 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1367-2630 J9 NEW J PHYS JI New J. Phys. PD JAN 17 PY 2003 VL 5 AR 5 DI 10.1088/1367-2630/5/1/305 PG 21 WC Physics, Multidisciplinary SC Physics GA 637MJ UT WOS:000180515600002 ER PT J AU Adamova, D Agakichiev, G Appelshauser, H Belaga, V Braun-Munzinger, P Castillo, A Cherlin, A Damjanovic, S Dietel, T Dietrich, L Drees, A Esumi, SI Filimonov, K Fomenko, K Fraenkel, Z Garabatos, C Glassel, P Hering, G Holeczek, J Kushpil, V Lenkeit, B Ludolphs, W Maas, A Marin, A Milosevic, J Milov, A Miskowiec, D Panebrattsev, Y Petchenova, O Petracek, V Pfeiffer, A Rak, J Ravinovich, I Rehak, P Sako, H Schmitz, W Schukraft, J Sedykh, S Shimansky, S Slivova, J Specht, HJ Stachel, J Sumbera, M Tilsner, H Tserruya, I Wessels, JP Wienold, T Windelband, B Wurm, JP Xie, W Yurevich, S Yurevich, V AF Adamova, D Agakichiev, G Appelshauser, H Belaga, V Braun-Munzinger, P Castillo, A Cherlin, A Damjanovic, S Dietel, T Dietrich, L Drees, A Esumi, SI Filimonov, K Fomenko, K Fraenkel, Z Garabatos, C Glassel, P Hering, G Holeczek, J Kushpil, V Lenkeit, B Ludolphs, W Maas, A Marin, A Milosevic, J Milov, A Miskowiec, D Panebrattsev, Y Petchenova, O Petracek, V Pfeiffer, A Rak, J Ravinovich, I Rehak, P Sako, H Schmitz, W Schukraft, J Sedykh, S Shimansky, S Slivova, J Specht, HJ Stachel, J Sumbera, M Tilsner, H Tserruya, I Wessels, JP Wienold, T Windelband, B Wurm, JP Xie, W Yurevich, S Yurevich, V CA CERES Collaboration TI Universal pion freeze-out in heavy-ion collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CORRELATIONS; INTERFEROMETRY; EXPANSION; RAPIDITY; PLASMA; HADRON AB Based on an evaluation of data on pion interferometry and on particle yields at midrapidity, we propose a universal condition for thermal freeze-out of pions in heavy-ion collisions. We show that freeze-out occurs when the mean free path of pions lambda(f) reaches a value of about 1 fm, which is much smaller than the spatial extent of the system at freeze-out. This critical mean free path is independent of the centrality of the collision and beam energy from the Alternating Gradient Synchrotron to the Relativistic Heavy Ion Collider. C1 Nucl Phys Inst ASCR, Rez 25068, Czech Republic. Gesell Schwerionenforsch mbH, D-64291 Darmstadt, Germany. Univ Heidelberg, Inst Phys, D-69120 Heidelberg, Germany. Joint Inst Nucl Res, Dubna 141980, Russia. Weizmann Inst Sci, IL-76100 Rehovot, Israel. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. CERN, CH-1211 Geneva 23, Switzerland. Brookhaven Natl Lab, Upton, NY 11973 USA. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. RP Adamova, D (reprint author), Nucl Phys Inst ASCR, Rez 25068, Czech Republic. RI Sumbera, Michal/O-7497-2014; Adamova, Dagmar/G-9789-2014; OI Sumbera, Michal/0000-0002-0639-7323; Maas, Axel/0000-0002-4621-2151 NR 37 TC 75 Z9 77 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 17 PY 2003 VL 90 IS 2 AR 022301 DI 10.1103/PhysRevLett.90.022301 PG 4 WC Physics, Multidisciplinary SC Physics GA 636FP UT WOS:000180444200011 PM 12570540 ER PT J AU Battaglieri, M Brunoldi, M De Vita, R Laget, JM Osipenko, M Ripani, M Taiuti, M Adams, G Amaryan, MJ Anciant, E Anghinolfi, M Armstrong, DS Asavapibhop, B Asryan, G Audit, G Auger, T Avakian, H Barrow, S Beard, K Bektasoglu, M Berman, BL Bersani, A Bianchi, N Biselli, AS Boiarinov, S Bouchigny, S Bradford, R Branford, D Briscoe, WJ Brooks, WK Burkert, VD Calarco, JR Capitani, GP Carman, DS Carnahan, B Cazes, A Cetina, C Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, JP DeSanctis, E Degtyarenko, PV Demirchyan, R Denizli, H Dennis, L Dharmawardane, KV Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Eckhause, M Egiyan, H Egiyan, KS Elouadrhiri, L Farhi, L Feuerbach, RJ Ficenec, J Forest, TA Freyberger, AP Frolov, V Funsten, H Gaff, SJ Gai, M Garcon, M Gavalian, G Gilad, S Gilfoyle, GP Giovanetti, KL Golovach, E Griffioen, K Guidal, M Guillo, M Guo, L Gyurjyan, V Hadjidakis, C Hancock, D Hardie, J Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Ito, MM Joo, K Kelley, JH Khandaker, M Kim, W Klein, A Klein, FJ Klimenko, AV Klusman, M Kossov, M Kramer, LH Kuang, Y Kuhn, SE Lachniet, J Lawrence, D Lucas, M Lukashin, K Major, RW Manak, JJ Marchand, C McAleer, S McCarthy, J McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Mikhailov, K Mirazita, M Miskimen, R Mokeev, V Morrow, S Mozer, MU Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nelson, SO Niccolai, S Niczyporuk, BB Niyazov, RA Nozar, M O'Brien, JT Opper, AK Peterson, G Philips, SA Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Preedom, BM Price, JW Protopopescu, D Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ritchie, BG Ronchetti, F Rossi, P Rowntree, D Rubin, PD Sabourov, K Salgado, C Sapunenko, V Schumacher, RA Serov, VS Shafi, A Sharabian, YG Shaw, J Skabelin, AV Smith, ES Smith, T Smith, LC Sober, DI Spraker, M Stavinsky, A Stepanyan, S Stoler, P Taylor, S Tedeschi, DJ Todor, L Thoma, U Thompson, R Vineyard, MF Vlassov, AV Wang, K Weinstein, LB Weller, H Weygand, DP Whisnant, CS Wolin, E Wood, M Yegneswaran, A Yun, J Zhang, B Zhao, J Zhou, Z AF Battaglieri, M Brunoldi, M De Vita, R Laget, JM Osipenko, M Ripani, M Taiuti, M Adams, G Amaryan, MJ Anciant, E Anghinolfi, M Armstrong, DS Asavapibhop, B Asryan, G Audit, G Auger, T Avakian, H Barrow, S Beard, K Bektasoglu, M Berman, BL Bersani, A Bianchi, N Biselli, AS Boiarinov, S Bouchigny, S Bradford, R Branford, D Briscoe, WJ Brooks, WK Burkert, VD Calarco, JR Capitani, GP Carman, DS Carnahan, B Cazes, A Cetina, C Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, JP DeSanctis, E Degtyarenko, PV Demirchyan, R Denizli, H Dennis, L Dharmawardane, KV Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Eckhause, M Egiyan, H Egiyan, KS Elouadrhiri, L Farhi, L Feuerbach, RJ Ficenec, J Forest, TA Freyberger, AP Frolov, V Funsten, H Gaff, SJ Gai, M Garcon, M Gavalian, G Gilad, S Gilfoyle, GP Giovanetti, KL Golovach, E Griffioen, K Guidal, M Guillo, M Guo, L Gyurjyan, V Hadjidakis, C Hancock, D Hardie, J Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Ito, MM Joo, K Kelley, JH Khandaker, M Kim, W Klein, A Klein, FJ Klimenko, AV Klusman, M Kossov, M Kramer, LH Kuang, Y Kuhn, SE Lachniet, J Lawrence, D Lucas, M Lukashin, K Major, RW Manak, JJ Marchand, C McAleer, S McCarthy, J McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Mikhailov, K Mirazita, M Miskimen, R Mokeev, V Morrow, S Mozer, MU Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nelson, SO Niccolai, S Niczyporuk, BB Niyazov, RA Nozar, M O'Brien, JT Opper, AK Peterson, G Philips, SA Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Preedom, BM Price, JW Protopopescu, D Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ritchie, BG Ronchetti, F Rossi, P Rowntree, D Rubin, PD Sabourov, K Salgado, C Sapunenko, V Schumacher, RA Serov, VS Shafi, A Sharabian, YG Shaw, J Skabelin, AV Smith, ES Smith, T Smith, LC Sober, DI Spraker, M Stavinsky, A Stepanyan, S Stoler, P Taylor, S Tedeschi, DJ Todor, L Thoma, U Thompson, R Vineyard, MF Vlassov, AV Wang, K Weinstein, LB Weller, H Weygand, DP Whisnant, CS Wolin, E Wood, M Yegneswaran, A Yun, J Zhang, B Zhao, J Zhou, Z CA CLAS Collaboration TI Photoproduction of the omega meson on the proton at large momentum transfer SO PHYSICAL REVIEW LETTERS LA English DT Article ID VECTOR-MESONS; REGGE TRAJECTORIES; SCATTERING; PHOTON; ELECTROPRODUCTION; THRESHOLD; SYSTEM; PION; CLAS AB The differential cross section, dsigma/dt, for omega meson exclusive photoproduction on the proton above the resonance region (2.63.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded. C1 Tohoku Univ, Res Ctr Neutrino Sci, Sendai, Miyagi 9808578, Japan. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Univ Hawaii Manoa, Dept Phys & Astron, Honolulu, HI 96822 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ New Mexico, Dept Phys, Albuquerque, NM 87131 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. Duke Univ, Dept Phys, Durham, NC 27706 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Univ N Carolina, Dept Phys, Chapel Hill, NC USA. Acad Sinica, Inst High Energy Phys, Beijing 100039, Peoples R China. RP Eguchi, K (reprint author), Tohoku Univ, Res Ctr Neutrino Sci, Sendai, Miyagi 9808578, Japan. RI MOTOKI, Masakazu/B-4212-2009; Decowski, Patrick/A-4341-2011; Murayama, Hitoshi/A-4286-2011; Horton-Smith, Glenn/A-4409-2011; Gould, Christopher/M-7676-2013; Kamyshkov, Yuri/J-7999-2016 OI Horton-Smith, Glenn/0000-0001-9677-9167; Kamyshkov, Yuri/0000-0002-3789-7152 NR 27 TC 1686 Z9 1699 U1 7 U2 42 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 17 PY 2003 VL 90 IS 2 AR 021802 DI 10.1103/PhysRevLett.90.021802 PG 6 WC Physics, Multidisciplinary SC Physics GA 636FP UT WOS:000180444200007 PM 12570536 ER PT J AU Luo, X Zhang, SB Wei, SH AF Luo, X Zhang, SB Wei, SH TI Understanding ultrahigh doping: The case of boron in silicon SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; ABSORPTION FINE-STRUCTURE; IMPURITY INCORPORATION; SURFACE SEGREGATION; FIRST-PRINCIPLES; FILM GROWTH; AB-INITIO; DIFFUSION; SI(111); GAAS AB Using first-principles calculations, we develop a theory for ultrahigh impurity doping in semiconductors. Our study of B in Si explains why boron solubility in epitaxial growth could exceed the solid solubility to reach the kinetic solubility, and, with adequate surface passivation, to reach even higher values. We further show that the partial ionization at high B concentration, C-B, observed by experiment is predominantly an electron chemical potential effect, not a boron clustering effect. Our calculated hole concentration over a wide C-B range is in reasonable agreement with experiments. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 34 TC 30 Z9 30 U1 0 U2 15 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 17 PY 2003 VL 90 IS 2 AR 026103 DI 10.1103/PhysRevLett.90.026103 PG 4 WC Physics, Multidisciplinary SC Physics GA 636FP UT WOS:000180444200030 PM 12570559 ER PT J AU Reichhardt, C Reichhardt, CJO Martin, I Bishop, AR AF Reichhardt, C Reichhardt, CJO Martin, I Bishop, AR TI Dynamical ordering of driven stripe phases in quenched disorder SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSITION-METAL OXIDES; LONG-RANGE INTERACTIONS; FLUX-LINE-LATTICE; VORTEX LATTICES; PERIODIC MEDIA; LOGARITHMIC INTERACTIONS; FLOW; SUMMATION; PATTERNS; SYSTEMS AB We examine the dynamics and stripe formation in a system with competing short and long-range interactions in the presence of both an applied dc drive and quenched disorder. Without disorder, the system forms stripes organized in a labyrinth state. We find that, when the disorder strength exceeds a critical value, an applied dc drive can induce a dynamical stripe ordering transition to a state that is more ordered than the originating undriven, unpinned pattern. We show that signatures in the structure factor and transport properties correspond to this dynamical reordering transition, and we present the dynamic phase diagram as a function of strengths of disorder and dc drive. C1 Los Alamos Natl Lab, Div Theoret, CNLS, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Reichhardt, C (reprint author), Los Alamos Natl Lab, Div Theoret, CNLS, Los Alamos, NM 87545 USA. OI Reichhardt, Cynthia/0000-0002-3487-5089 NR 36 TC 49 Z9 49 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 17 PY 2003 VL 90 IS 2 AR 026401 DI 10.1103/PhysRevLett.90.026401 PG 4 WC Physics, Multidisciplinary SC Physics GA 636FP UT WOS:000180444200033 PM 12570562 ER PT J AU Lahann, J Mitragotri, S Tran, TN Kaido, H Sundaram, J Choi, IS Hoffer, S Somorjai, GA Langer, R AF Lahann, J Mitragotri, S Tran, TN Kaido, H Sundaram, J Choi, IS Hoffer, S Somorjai, GA Langer, R TI A reversibly switching surface SO SCIENCE LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SUM-FREQUENCY GENERATION; IN-SITU STRUCTURE; GOLD ELECTRODES; ACTIVE CONTROL; NUCLEIC-ACIDS; FORCE-FIELD; CONTACT; SPECTROSCOPY; INTERFACE C1 MIT, Dept Chem Engn, Cambridge, MA 02139 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. Univ Calif Berkeley, Dept Chem, Div Mat Sci, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP MIT, Dept Chem Engn, 45 Carleton St, Cambridge, MA 02139 USA. EM rlanger@mit.edu RI CHOI, INSUNG S./C-1592-2011; Lahann, Joerg/J-7663-2013 NR 34 TC 786 Z9 795 U1 26 U2 356 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 17 PY 2003 VL 299 IS 5605 BP 371 EP 374 DI 10.1126/science.1078933 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 635YB UT WOS:000180426800038 PM 12532011 ER PT J AU Genbacev, OD Prakobphol, A Foulk, RA Krtolica, AR Ilic, D Singer, MS Yang, ZQ Kiessling, LL Rosen, SD Fisher, SJ AF Genbacev, OD Prakobphol, A Foulk, RA Krtolica, AR Ilic, D Singer, MS Yang, ZQ Kiessling, LL Rosen, SD Fisher, SJ TI Trophoblast L-selectin-mediated adhesion at the maternal-fetal interface SO SCIENCE LA English DT Article ID HIGH-ENDOTHELIAL VENULES; HUMAN CYTOTROPHOBLASTS; LYMPHOCYTES; INVASION; RECEPTORS; LIGAND; CELLS AB Trophoblast adhesion to the uterine wall is the requisite first step of implantation and, subsequently, placentation. At the maternal-fetal interface, we investigated the expression of selectin adhesion systems that enable leukocyte capture from the bloodstream. On the maternal side, human uterine epithelial cells up-regulated selectin oligosaccharide-based ligands during the window of receptivity. On the fetal side, human trophoblasts expressed L-selectin. This ligand-receptor system was functional, because beads coated with the selectin ligand 6-sulfo sLe(x) bound to trophoblasts, and trophoblasts bound to ligand-expressing uterine luminal epithelium in tissue sections. These results suggest that trophoblast L-selectin mediates interactions with the uterus and that this adhesion mechanism may be critical to establishing human pregnancy. C1 Univ Calif San Francisco, Dept Stomatol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Nevada Ctr Reprod Med, Reno, NV 89509 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Wisconsin, Dept Chem, Madison, WI 53706 USA. Univ Wisconsin, Dept Biochem, Madison, WI 53706 USA. RP Fisher, SJ (reprint author), Univ Calif San Francisco, Dept Stomatol, San Francisco, CA 94143 USA. RI Kiessling, Laura/A-4074-2008 FU NHLBI NIH HHS [HL 64597]; NICHD NIH HHS [U01 HD 42283]; NIDCR NIH HHS [DE 07244]; NIGMS NIH HHS [R37GM23547] NR 18 TC 244 Z9 273 U1 1 U2 21 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 17 PY 2003 VL 299 IS 5605 BP 405 EP 408 DI 10.1126/science.1079546 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 635YB UT WOS:000180426800049 PM 12532021 ER PT J AU Wang, DH Zhou, WL McCaughy, BF Hampsey, JE Ji, XL Jiang, YB Xu, HF Tang, JK Schmehl, RH O'Connor, C Brinker, CJ Lu, YF AF Wang, DH Zhou, WL McCaughy, BF Hampsey, JE Ji, XL Jiang, YB Xu, HF Tang, JK Schmehl, RH O'Connor, C Brinker, CJ Lu, YF TI Electrodeposition of metallic nanowire thin films using mesoporous silica templates SO ADVANCED MATERIALS LA English DT Article ID ARRAYS; AG AB Metal nanowire thin films have been obtained by electrodeposition into mesoporous silica thin-film templates, resulting in nanowire arrays that reflect the pore structure of the template. Removal of silica is achieved via annealing followed by etching to leave mechanically strong freestanding metal nanowire films (see Figure). These metal films have many potential applications, such as electrodes, optical hosts, catalysts, magnetic materials, photovoltaic devices, and sensors. C1 Tulane Univ, Dept Chem Engn, New Orleans, LA 70118 USA. Univ New Orleans, Adv Mat Res Inst, New Orleans, LA 70148 USA. Univ New Mexico, Dept Earth & Planetary Sci, Transmiss Electron Microscopy Lab, Albuquerque, NM 87131 USA. Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. Tulane Univ, Dept Chem, New Orleans, LA 70118 USA. Univ New Mexico, Sandia Natl Labs, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RP Lu, YF (reprint author), Tulane Univ, Dept Chem Engn, New Orleans, LA 70118 USA. EM ylu@tulane.edu RI Schmehl, Russell/D-2558-2011; Wang, Donghai/L-1150-2013 OI Wang, Donghai/0000-0001-7261-8510 NR 22 TC 97 Z9 99 U1 3 U2 49 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 16 PY 2003 VL 15 IS 2 BP 130 EP + DI 10.1002/adma.200390025 PG 5 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 644DF UT WOS:000180902100010 ER PT J AU Vasco, DW Johnson, LR Marques, O AF Vasco, DW Johnson, LR Marques, O TI Resolution, uncertainty, and whole Earth tomography SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID LARGE MATRIX INVERSIONS; TRAVEL-TIME TOMOGRAPHY; CORE-MANTLE BOUNDARY; SEISMIC TOMOGRAPHY; VELOCITY STRUCTURE; LIQUID-CORE; ARRIVAL TIMES; P-VELOCITY; COVARIANCE; PHASES AB [1] Using the arrival times of 10 distinct phases from the International Seismological Center catalogue (P, S, PP, PcP, SS, ScS, PKPab, PKPbc, PKPdf, SKSac) and two sets of differential times (SS - S410S and SS - S660S), we estimate the P and S velocity structure of the whole Earth (mantle, outer core, and inner core), boundary topography of four interfaces within the Earth, hypocentral relocation parameters, and station corrections. The entire catalogue is relocated and reassociated using the radial velocity model ak135. Both P and S phases are used in the relocation of over 41,000 events. In depth, isotropic velocity variations within the Earth are parameterized by 22 layers. Lateral variations in shear and compressional velocity within the layers are represented by one of two grids. In the mantle, each layer is subdivided into 4560 equal-volume cells, of dimension 3degrees x 3degrees at the equator. However, in the outer and inner core, the cell size is increased to 6degrees x 6degrees. This change in grid spacing accounts for decreasing cell volumes with depth and variations in sampling between the mantle and core. Previous attempts using a fine grid throughout the Earth resulted in poor resolution of core structure. With the current grid, the resolution of velocity heterogeneity in the mantle and outer core is comparable. In the upper and midmantle, the well-resolved cells lie beneath Eurasia and a narrow zone surrounding the mantle beneath the Pacific basin. In the lowest mantle, the resolution decreases significantly. An examination of the averaging kernels associated with six locations near the base of the mantle reveals the significant lateral and vertical averaging inherent in estimates of compressional velocity. In well-sampled regions of the outer core, we are able to resolve compressional velocity variations in our 6degrees x 6degrees cells. However, velocity variations in the inner core are poorly constrained at the scale of our blocks. In well-sampled regions of the mantle and outer core model, parameter standard deviations remain below 0.25%. For much of the inner core, the standard deviations are quite large, exceeding 0.5%. Narrow, high-velocity anomalies are imaged in the upper mantle, associated with subduction zones. In a number of locations, such as beneath the Americas, these features extend well into the lower mantle. In the outer core, heterogeneity is generally lower in magnitude, of the order of 0.5%. The most notable feature in the outer core is a systematic shift to slightly higher velocity. In addition, we find a roughly symmetric distribution of heterogeneity at the base of the outer core. Compressional velocities are generally higher in the equatorial regions and lower at the poles. C1 Univ Calif Berkeley, Berkeley Lab, Ctr Computat Seismol, Berkeley, CA 94720 USA. Univ Calif Berkeley, High Performance Comp Res Dept, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley Seismol Lab, Berkeley, CA 94720 USA. RP Vasco, DW (reprint author), Univ Calif Berkeley, Berkeley Lab, Ctr Computat Seismol, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM dwvasco@lbl.gov; lrj@ccs.lbl.gov RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 59 TC 20 Z9 20 U1 0 U2 4 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 16 PY 2003 VL 108 IS B1 AR 2022 DI 10.1029/2001JB000412 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 659WB UT WOS:000181799500001 ER PT J AU Trasobares, S Kolczewski, C Raty, R Borglund, N Bassan, A Hug, G Colliex, C Csillag, S Pettersson, LGM AF Trasobares, S Kolczewski, C Raty, R Borglund, N Bassan, A Hug, G Colliex, C Csillag, S Pettersson, LGM TI Monitoring the decomposition of melamine in the solid phase by electron energy loss chronospectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID K-SHELL; OSCILLATOR-STRENGTHS; CORE EXCITATION; BASIS SETS; NANOTUBES; SPECTROSCOPY; IONIZATION; MOLECULES; PYRIDINE; GAS AB The decomposition process of melamine exposed to a high-energy electron beam has been investigated by monitoring the changes in the energy loss near edge structures (ELNES) using time-resolved electron energy loss spectroscopy. Calculations on different CN-containing molecules were performed in order to simulate the experimental ELNES observed at the different decomposition stages and to identify some of the intermediate compounds produced during this degradation process. As a result, we suggest that the amino groups are first eliminated as a release of N-2 gas. Then, the degradation of the molecule occurs through a reduction of the carbon-nitrogen double bonds. If the irradiation is maintained over longer periods, the formation of different CN fragments could then be possible. C1 Univ Paris 11, CNRS, UMR 8502, Phys Solides Lab, F-91405 Orsay, France. Stockholm Univ, Dept Phys, Stockholm Ctr Phys Astron & Biotechnol, S-10691 Stockholm, Sweden. Off Natl Etud & Rech Aerosp, LEM, F-92322 Chatillon, France. RP Trasobares, S (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave,Bldg 200-D125, Argonne, IL 60439 USA. RI Pettersson, Lars/F-8428-2011; Pettersson, Lars/J-4925-2013; Trasobares, Susana/H-5282-2015 OI Pettersson, Lars/0000-0003-1133-9934; Trasobares, Susana/0000-0003-3820-4327 NR 37 TC 5 Z9 5 U1 0 U2 3 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 16 PY 2003 VL 107 IS 2 BP 228 EP 235 DI 10.1021/jp026340j PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 635QN UT WOS:000180410500003 ER PT J AU Martin, JE Odinek, J Wilcoxon, JP Anderson, RA Provencio, P AF Martin, JE Odinek, J Wilcoxon, JP Anderson, RA Provencio, P TI Sintering of alkanethiol-capped gold and platinum nanoclusters SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MELTING TEMPERATURE; PARTICLES AB One of the unusual properties of metal nanoclusters is the size dependence of the melting temperature. Studies show that the melting temperature is a decreasing function of the cluster diameter, although the actual dependence is not known, due to the difficulties associated with the experimental measurements. We have synthesized narrow dispersity alkanethiol-functionalized An and Pt nanoclusters in inverse micellar solutions and have measured the sintering temperatures of these films using a capacitance technique to determine the onset of film conductivity. Cluster sintering is accompanied by pronounced optical changes and a thermal signature that can be observed in differential thermal analysis. The large optical absorbance of nanocluster films makes laser sintering a practical method for the formation of metallization layers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 29 Z9 29 U1 2 U2 15 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 16 PY 2003 VL 107 IS 2 BP 430 EP 434 DI 10.1021/jp020489d PG 5 WC Chemistry, Physical SC Chemistry GA 635QP UT WOS:000180410600004 ER PT J AU Wang, LQ Exarhos, GJ AF Wang, LQ Exarhos, GJ TI Study of local molecular ordering in layered surfactant-silicate mesophase composites SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SOLID-STATE NMR; LIQUID-CRYSTAL TEMPLATE; MESOPOROUS MATERIALS; SIEVES; MCM-41; ORGANIZATION; PHASES; CONFORMATION; MECHANISM; MOBILITY AB We have synthesized layered surfactant-silicate mesophase composites using surfactant-templated synthetic routes under hydrothermal conditions. Local molecular ordering in both the bound surfactant and the inorganic framework for these mesophase composites has been observed and investigated using solid-state NMR and X-ray diffraction techniques. Synthesis parameters were systematically varied to determine the key factors that influence the molecular-ordering process. The dynamics and mobility of surfactant molecules at the interface have also been examined using NMR chemical-shift analyses, relaxation-time studies, and 2D WISE measurements. Results from this current work are compared with studies reported on other surfactant-silicate mesoporous materials. C1 Pacific NW Natl Lab, Dept Mat Sci, Richland, WA 99352 USA. RP Wang, LQ (reprint author), Pacific NW Natl Lab, Dept Mat Sci, Battelle Blvd, Richland, WA 99352 USA. NR 28 TC 21 Z9 21 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 16 PY 2003 VL 107 IS 2 BP 443 EP 450 DI 10.1021/jp021512y PG 8 WC Chemistry, Physical SC Chemistry GA 635QP UT WOS:000180410600006 ER PT J AU Boxley, CJ White, HS Lister, TE Pinhero, PJ AF Boxley, CJ White, HS Lister, TE Pinhero, PJ TI Electrochemical deposition and reoxidation of Au at highly oriented pyrolytic graphite. Stabilization of Au nanoparticles on the upper plane of step edges SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; MOLECULE CORRALS; BASAL-PLANE; SILVER NANOCRYSTALLITES; ORDERED GRAPHITE; SURFACES; CARBON; GOLD; ELECTRODEPOSITION; STM AB The electrochemical deposition and reoxidation of Au on the basal plane of highly oriented pyrolytic graphite (HOPG) immersed in a 5 mM AuCl4-/6 M LiCl solution is reported. Scanning electron microscopy (SEM) and ex-situ atomic force microscopy (AFM) demonstrate that An nanoparticles, similar to3.3 nm in height and similar to10 nm in diameter, are deposited at times less than similar to1 s. The density of nanoparticles, 6 x 10(9) cm(-2), is of the same order of magnitude as the surface point defect density, suggesting that point defects act as nucleation sites for An electrodeposition. A small subset of the Au nanoparticles (similar to7%) continues to grow between 1 and 50 s, reaching a height of similar to150 nm and a diameter of similar to300 nm. At times greater than 50 s, the larger particles coalesce to yield a surface comprised of a low density (similar to2 x 10(6) cm(-2)) of micrometer-size An crystallites surrounded by An nanoparticles. Double potential step chronocoulometric experiments demonstrate that the electrodeposition of Au is chemically irreversible, a finding supported by SEM and AFM observations of An nanoparticles and larger crystallites on the surface after long periods of reoxidation (>3600 s). Au nanoparticles are observed to be preferentially deposited on the upper plane of step edges, a consequence of the nonuniform surface electron density that results from relaxation of the graphite lattice near steps. C1 Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP White, HS (reprint author), Univ Utah, Dept Chem, 315 S 1400 E, Salt Lake City, UT 84112 USA. NR 43 TC 28 Z9 28 U1 0 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 16 PY 2003 VL 107 IS 2 BP 451 EP 458 DI 10.1021/jp026496j PG 8 WC Chemistry, Physical SC Chemistry GA 635QP UT WOS:000180410600007 ER PT J AU Henderson, MA Epling, WS Peden, CHF Perkins, CL AF Henderson, MA Epling, WS Peden, CHF Perkins, CL TI Insights into photoexcited electron scavenging processes on TiO2 obtained from studies of the reaction of O-2 with OH groups adsorbed at electronic defects on TiO2(110) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; HETEROGENEOUS PHOTOCATALYTIC OXIDATION; DIFFUSE-REFLECTANCE SPECTROSCOPY; CHARGE RECOMBINATION KINETICS; OXYGEN ISOTOPE EXCHANGE; TITANIUM-DIOXIDE FILMS; NANOSTRUCTURED TIO2; MOLECULAR-OXYGEN; PHOTOPHYSICAL PROPERTIES; SURFACE-STRUCTURE AB In this study we show that molecular oxygen reacts with bridging OH (OHbr) groups formed as a result of water dissociation at oxygen vacancy defects on the surface of rutile TiO2(110). The electronic structure of an oxygen vacancy defect on TiO2(110) is essentially the same as that of electron trap states detected on photoexcited or sensitized TiO2 photocatalysts, being Ti3+ in nature. Electron energy loss spectroscopy (EELS) measurements, in agreement with valence band photoemission results in the literature, indicate that water dissociation at oxygen vacancy sites has little or no impact on the electronic structure of these sites. Temperature programmed desorption (TPD) measurements show that O-2 adsorbed at 120 K reacts with near unity reaction probability with OHbr groups on TiO2(110) to form an unidentified intermediate that decomposes to generate terminal OH groups at nondefect sites. Commensurate with this process, the electronic defect associated with the original oxygen vacancy defect (Ti3+) is oxidized. Vibrational EELS results indicate that the reaction between O-2 and OHbr occurs at about 230 K, whereas electronic EELS results suggest that charge is transferred away from the vacancies at 90 K. Detailed TPD experiments in which the precoverage of water was varied indicate that chemisorption of O-2 at cation sites on the TiO2(110) surface is not required in order for the reaction between O-2 and OHbr to occur, which implies a direct interaction between weakly bound (physisorbed) O-2 and the OHbr groups. In agreement with this conclusion, we find that second-layer water, which selectively hydrogen-bonds to bridging O2- sites and bridging OH groups, blocks the reaction of O-2 with OHbr groups and prevents oxidation of the vacancy-related Ti3+ electronic state. These results suggest that the electron scavenging role of O-2 in photocatalysis may involve a direct reaction between O-2, and trapped electrons located at bridging OH groups. Our studies suggest that the negative influence of high water concentrations in gas-phase heterogeneous photocatalysis studies results from hydrogen-bonded water blocking access of O-2 to trapped electrons located at surface OH groups. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Henderson, MA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999,MS K8-93, Richland, WA 99352 USA. OI Peden, Charles/0000-0001-6754-9928 NR 100 TC 287 Z9 289 U1 14 U2 137 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 16 PY 2003 VL 107 IS 2 BP 534 EP 545 DI 10.1021/jp0262113 PG 12 WC Chemistry, Physical SC Chemistry GA 635QP UT WOS:000180410600019 ER PT J AU Ghosh, T Garcia, AE Garde, S AF Ghosh, T Garcia, AE Garde, S TI Water-mediated three-particle interactions between hydrophobic solutes: Size, pressure, and salt effects SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; FREE-ENERGY CALCULATIONS; TEMPERATURE-DEPENDENCE; STATISTICAL-MECHANICS; ENTROPY CONVERGENCE; SURFACE-AREA; MONTE-CARLO; HYDRATION; MODEL; COOPERATIVITY AB We use molecular dynamics (MD) simulations of solutions of hydrophobic solutes in explicit water to study the many-body character of hydrophobic interactions at the level of solute-solute-solute three-particle correlations. Comparisons of the calculated three-particle potentials of mean force (PMF) with that obtained by adding solute-solute pair PMFs are used to quantify the many-body effect. Our results shed light on both the range and magnitude of many-body (i.e., nonadditivity) effects. We find that the nonadditivity effects depend on the specific configuration of the three interacting particles and are short-ranged, restricted primarily to locations of the third solute within the first two solvation shells of the primary solute pair. The contact and solvent-separated configurations show anticooperative behavior (i.e., the actual three-particle PMF is less favorable than the pairwise additive approximation), whereas cooperativity is observed at the desolvation barrier. Increasing the solute size makes the nonadditive effects uniformly more anticooperative. Nonadditivity behavior is also short-ranged at higher pressures and in NaCl solutions. Interestingly, increasing pressure changes the nonadditivity effects toward cooperativity, whereas the opposite is true upon the addition of salt to the solution. The implications of these results on more complex self-assembly processes are discussed. C1 Rensselaer Polytech Inst, Dept Chem Engn, Troy, NY 12180 USA. Los Alamos Natl Lab, Theoret Biol & Biophys Grp, Los Alamos, NM 87545 USA. RP Garde, S (reprint author), Rensselaer Polytech Inst, Dept Chem Engn, Troy, NY 12180 USA. RI Garde, Shekhar/C-3060-2008 NR 68 TC 48 Z9 48 U1 5 U2 12 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 16 PY 2003 VL 107 IS 2 BP 612 EP 617 DI 10.1021/jp0220175 PG 6 WC Chemistry, Physical SC Chemistry GA 635QP UT WOS:000180410600030 ER PT J AU Hu, DH Lu, HP AF Hu, DH Lu, HP TI Single-molecule nanosecond anisotropy dynamics of tethered protein motions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID RESOLVED FLUORESCENCE ANISOTROPY; SCANNING OPTICAL MICROSCOPY; POLARIZATION SPECTROSCOPY; CONFORMATIONAL DYNAMICS; REORIENTATION DYNAMICS; ROTATIONAL DIFFUSION; ENZYMATIC DYNAMICS; ROOM-TEMPERATURE; IDENTIFICATION; ORIENTATIONS AB Confined and hindered protein motions generally exist in living cells, with tethered proteins or protein domains particularly associated with and relevant to the early events of molecular interactions in cell signaling at extra- and intracellular membrane surfaces. Ensemble-averaged, time-resolved fluorescence anisotropy has been extensively applied to study the protein rotational and conformational motion dynamics under physiologically relevant conditions. However, the spatial and temporal inhomogeneities of the nonsynchronizable stochastic protein rotational and conformational motions are extremely difficult to characterize with such ensemble-averaged measurements. Here, we demonstrate the use of single-molecule nanosecond anisotropy to study the tethered protein motion of a T4 lysozyme molecule on a biologically compatible surface under water. The rotational motions of tethered proteins are confined in a half-sphere whose volume is primarily defined by the linker and the surface. We observe dynamic inhomogeneities of the rotational diffusion dynamics, i.e., diffusion rate fluctuation, because of interactions between the proteins and the surface. However, we also find that the long-time averages of the dynamically inhomogeneous diffusion rates of single molecules are essentially homogeneous among the single molecules examined. Moreover, tethered proteins stay predominately in solution, rather than being fixed on the modified surface. The infrequent surface interactions are not energetic enough to fix the protein rotational motions. These results suggest that the motions of proteins tethered to surfaces are dynamically inhomogeneous, even if the surfaces or the local environments are homogeneous; in contrast, static inhomogeneity of the rotation dynamics can only exist when the local surface or the local environment are inhomogeneous. Furthermore, the tethered-proteins are found to be in solution without rotational rate fluctuations for most of the time during the measurements, suggesting that the use of tethered proteins on modified glass surfaces under water is a reasonable way to study protein dynamics in solution, as many single-molecule experiments have demonstrated. Our approach allows the recording of time trajectories of the single-molecule rotation rate fluctuation and reveals the single-molecule rotational motion over wide time scale from subnanoseconds to seconds. C1 Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Lu, HP (reprint author), Pacific NW Natl Lab, Fundamental Sci Div, POB 999, Richland, WA 99352 USA. RI Hu, Dehong/B-4650-2010 OI Hu, Dehong/0000-0002-3974-2963 NR 47 TC 37 Z9 37 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 16 PY 2003 VL 107 IS 2 BP 618 EP 626 DI 10.1021/jp0213654 PG 9 WC Chemistry, Physical SC Chemistry GA 635QP UT WOS:000180410600031 ER PT J AU Chandler, DP Jarrell, AE AF Chandler, DP Jarrell, AE TI Enhanced nucleic acid capture and flow cytometry detection with peptide nucleic acid probes and tunable-surface microparticles SO ANALYTICAL BIOCHEMISTRY LA English DT Article DE suspension array; peptide nucleic acid; flow cytometry; sequential injection; microfluidic; renewable surface; 16S rRNA ID DNA HYBRIDIZATION; SOIL EXTRACTS; RIBOSOMAL-RNA; PNA; AMPLIFICATION; ASSAY; OLIGONUCLEOTIDES; MICROCOLUMNS; PURIFICATION; MICROARRAYS AB New methods for automated, direct nucleic acid purification and detection are required for the next generation of unattended environmental monitoring devices. In this study we investigated whether tunable-surface bead chemistry and peptide nucleic acids (PNA) could enhance the recovery and detection of intact rRNA in both test tube and automated suspension array hybridization formats. Intact rRNA was easily captured and detected on PNA-coated Lumavidin beads from 0.1 ng total RNA with a 15-min hybridization in pH 7 buffer, representing 1.7 x 10(3) cell equivalents of total RNA. DNA-conjugated beads in pH 5 hybridization buffer required an overnight hybridization to achieve a detectable signal at 0.1 ng target RNA. Standard DNA hybridization conditions (pH 7) were one order of magnitude less sensitive than the tunable-surface (pH 5) condition. The PNA-conjugated particles were 100 x more sensitive than the tunable-surface DNA particles in the automated format, with a detection limit of 0.1 ng total RNA. The detection limits for total RNA on PNA-conjugated microparticles is immediately conducive to the detection and characterization of microorganisms in low-biomass environments or to the identification of rare sequences in a complex sample mixture, without using PCR. Published by Elsevier Science (USA). C1 Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. Pacific NW Natl Lab, Analyt Microbiol Grp, Richland, WA 99352 USA. RP Chandler, DP (reprint author), Argonne Natl Lab, Biochip Technol Ctr, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 34 TC 24 Z9 28 U1 1 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD JAN 15 PY 2003 VL 312 IS 2 BP 182 EP 190 AR PII S0003-2697(02)00445-1 DI 10.1016/S0003-2697(02)00445-1 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 640VW UT WOS:000180709500014 PM 12531204 ER PT J AU Stratis-Cullum, DN Griffin, GD Mobley, J Vass, AA Vo-Dinh, T AF Stratis-Cullum, DN Griffin, GD Mobley, J Vass, AA Vo-Dinh, T TI A miniature biochip system for detection of aerosolized Bacillus globigii spores SO ANALYTICAL CHEMISTRY LA English DT Article ID FIBER OPTIC BIOSENSOR AB The feasibility of using a novel detection scheme for the analysis of biological warfare agents is demonstrated using Bacillus globigii spores, a surrogate species for Bacillus anthracis. In this paper, a sensitive and selective enzyme-linked immunosorbent assay using a novel fluorogenic alkaline phosphatase substrate (dimethylactidinone phosphate) is combined with a compact biochip detection system, which includes a miniature diode laser for excitation. Detection of aerosolized spores was achieved by coupling the miniature system to a portable bioaerosol sampler, and the performance of the antibody-based recognition and enzyme amplification method was evaluated. The bioassay performance was found to be compatible with the air sampling device, and the enzymatic amplification was found to be an attractive amplification method for detection of low spore concentrations. The combined portable bioaerosol sampler and miniature biochip system detected 100 B. globigii spores, corresponding to 17 aerosolized spores/L of air. Moreover, the incorporation of the miniature diode laser with the self-contained biochip design allows for a compact system that is readily adaptable to field use. In addition, these studies have included investigations into the tradeoff between assay time and sensitivity. C1 Oak Ridge Natl Lab, Adv Biomed Sci & Technol Grp, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Adv Biomed Sci & Technol Grp, Bethel Valley Rd,MS-6101 POB 2008, Oak Ridge, TN 37831 USA. NR 15 TC 73 Z9 74 U1 0 U2 16 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 2003 VL 75 IS 2 BP 275 EP 280 DI 10.1021/ac026068+ PG 6 WC Chemistry, Analytical SC Chemistry GA 635ZM UT WOS:000180430100014 PM 12553762 ER PT J AU King, BV Pellin, MJ Moore, JF Veryovkin, IV Savina, MR Tripa, CE AF King, BV Pellin, MJ Moore, JF Veryovkin, IV Savina, MR Tripa, CE TI Estimation of useful yield in surface analysis using single photon ionisation SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 13th International Conference on Secondary Ion Mass Spectrometry and Related Topics (SIMS XIII) CY NOV 11-16, 2001 CL NARA, JAPAN DE postionisation; laser desorption; SIMS; SAM; useful yield ID IONIZATION MASS-SPECTROMETRY AB Secondary ion mass spectrometry (SIMS), laser sputter neutral mass spectrometry (SNMS) and laser desorption photo-ionisation (LDPI) have been used to investigate the desorption of molecules from self-assembled monolayers of phenylsulphides. LDPI, using an F-2 excimer laser to single photon ionise gave the lowest fragmentation. A useful yield greater than 0.5% was found for analysis of diphenyldisulphide self-assembled monolayers. It is shown that using a free electron laser to postionise will lead, in the future, to analysis of many atoms and molecules with useful yields approaching 30%. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Newcastle, Sch Math & Phys Sci, Callaghan, NSW 2308, Australia. Argonne Natl Lab, Argonne, IL 60439 USA. RP King, BV (reprint author), Univ Newcastle, Sch Math & Phys Sci, Callaghan, NSW 2308, Australia. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 8 TC 16 Z9 17 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD JAN 15 PY 2003 VL 203 BP 244 EP 247 AR PII S0169-4332(02)00636-0 DI 10.1016/S0169-4332(02)00636-0 PG 4 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 637RT UT WOS:000180527300055 ER PT J AU Kwon, T Chang, JH Kwak, E Lee, CW Joachimiak, A Kim, YC Lee, JW Cho, YJ AF Kwon, T Chang, JH Kwak, E Lee, CW Joachimiak, A Kim, YC Lee, JW Cho, YJ TI Mechanism of histone lysine methyl transfer revealed by the structure of SET7/9-AdoMet SO EMBO JOURNAL LA English DT Article DE compact form of AdoMet; 9 histone methyltransferase; post-SET helix; SET7; SET domain; substrate-specific channel ID HP1 CHROMO DOMAIN; COVALENT MODIFICATIONS; H3; METHYLTRANSFERASES; HETEROCHROMATIN; PROTEIN; RECOGNITION; SPECIFICITY; CODE; SITE AB The methylation of lysine residues of histones plays a pivotal role in the regulation of chromatin structure and gene expression. Here, we report two crystal structures of SET7/9, a histone methyltransferase (HMTase) that transfers methyl groups to Lys4 of histone H3, in complex with S-adenosyl-L-methionine (AdoMet) determined at 1.7 and 2.3 Angstrom resolution. The structures reveal an active site consisting of: (i) a binding pocket between the SET domain and a c-SET helix where an AdoMet molecule in an unusual conformation binds; (ii) a narrow substrate-specific channel that only unmethylated lysine residues can access; and (iii) a catalytic tyrosine residue. The methyl group of AdoMet is directed to the narrow channel where a substrate lysine enters from the opposite side. We demonstrate that SET7/9 can transfer two but not three methyl groups to unmodified Lys4 of H3 without substrate dissociation. The unusual features of the SET domain-containing HMTase discriminate between the un- and methylated lysine substrate, and the methylation sites for the histone H3 tail. C1 Pohang Univ Sci & Technol, Natl Creat Res Initiat Ctr Struct Biol, Pohang 790784, KyungBook, South Korea. Pohang Univ Sci & Technol, Dept Life Sci, Pohang 790784, KyungBook, South Korea. Argonne Natl Lab, Struct Biol Ctr, Biosci Div, Argonne, IL 60439 USA. RP Cho, YJ (reprint author), Pohang Univ Sci & Technol, Natl Creat Res Initiat Ctr Struct Biol, San31, Pohang 790784, KyungBook, South Korea. NR 50 TC 79 Z9 82 U1 0 U2 16 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0261-4189 J9 EMBO J JI Embo J. PD JAN 15 PY 2003 VL 22 IS 2 BP 292 EP 303 DI 10.1093/emboj/cdg025 PG 12 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 638KJ UT WOS:000180569900013 PM 12514135 ER PT J AU Templeton, AS Trainor, TP Spormann, AM Newville, M Sutton, SR Dohnalkova, A Gorby, Y Brown, GE AF Templeton, AS Trainor, TP Spormann, AM Newville, M Sutton, SR Dohnalkova, A Gorby, Y Brown, GE TI Sorption versus biomineralization of Pb(II) within Burkholderia cepacia biofilms SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID RAY-ABSORPTION-SPECTRA; LEAD RESISTANCE; MULTIPLE-SCATTERING; BACTERIAL SURFACES; CONTAMINATED SOILS; EXAFS SPECTROSCOPY; WATER INTERFACES; METAL ADSORPTION; BINDING-SITES; CELL-WALLS AB X-ray spectroscopy measurements have been combined with macroscopic uptake data and transmission electron microscopy (TEM) results to show that Pb(II) uptake by Burkholderia cepacia is due to simultaneous sorption and biomineralization processes. X-ray microprobe mapping of B. cepacia biofilms formed on alpha-Al2O3 surfaces shows that Pb(II) is distributed heterogeneously throughout the biofilms because of the formation of Pb "hot spots". EXAFS data and TEM observations show that the enhanced Pb accumulation is due to the formation of nanoscale crystals of pyromorphite (Pb-5(PO4)(3)(OH)) adjacent to the outermembrane of a fraction of the total population of B. cepacia cells. In contrast, B. cepacia cell suspensions or biofilms that were heat-killed or pretreated with X-rays do not form pyromorphite, which suggests that metabolic activity is required. Precipitation of pyromorphite occurs over several orders of magnitude in [H+] and [Pb] and accounts for approximately 90% of the total Pb uptake below pH 4.5 but only 45-60% at near-neutral pH because of the formation of additional Pb(II) adsorption complexes. Structural fits of Pb L-III EXAFS data collected for heat-treated cells at near-neutral pH suggest that Pb(II) forms inner-sphere adsorption complexes with carboxyl functional groups in the biofilms. C1 Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94035 USA. Univ Chicago, Argonne Natl Lab, Consortium Adv Radiat Sources, Argonne, IL 60439 USA. Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Templeton, AS (reprint author), Scripps Inst Oceanog, Div Marine Biol Res, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM atempleton@ucsd.edu OI TEMPLETON, ALEXIS/0000-0002-9670-0647 NR 41 TC 42 Z9 44 U1 6 U2 29 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 2003 VL 37 IS 2 BP 300 EP 307 DI 10.1021/es025972g PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 637FT UT WOS:000180501500014 PM 12564901 ER PT J AU Mark, TD Futrell, JH AF Mark, TD Futrell, JH TI Special issue - Dedicated to the memory of Werner Lindinger - Foreword SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Editorial Material C1 Univ Innsbruck, Inst Ionenphys, A-6020 Innsbruck, Austria. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Univ Innsbruck, Inst Ionenphys, Technikerstr 25, A-6020 Innsbruck, Austria. RI Mark, Tilmann/J-1650-2014 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 EI 1873-2798 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN 15 PY 2003 VL 223 IS 1-3 BP XI EP XII AR PII S1387-3806(02)01046-1 DI 10.1016/S1387-3806(02)01046-1 PG 2 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 634WT UT WOS:000180366000001 ER PT J AU Vockenhuber, C Ahmad, I Golser, R Kutschera, W Liechtenstein, V Priller, A Steier, P Winkler, S AF Vockenhuber, C Ahmad, I Golser, R Kutschera, W Liechtenstein, V Priller, A Steier, P Winkler, S TI Accelerator mass spectrometry of heavy long-lived radionuclides SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE accelerator mass spectrometry; heavy radionuclides; VERA ID HALF-LIFE; AMS; VERA; SN-126; U-236; PROSPECTS; ISOTOPES; SAMPLES; SYSTEM; VIENNA AB This paper describes the upgrade of the Vienna Environmental Research Accelerator (VERA) to a universal facility for accelerator mass spectrometry (AMS). As a result, it is now possible to measure many long-lived radionuclides at natural abundances across the nuclear chart, from the lightest (Be-10) to the heaviest (Pu-244). Particular emphasis is placed on measurements to understand the ion optics and the origin of background ions, which ultimately limit the sensitivity. VERA is now ready to venture into the realm of actinides (e.g., U-236, Pu-244), and other heavy radionuclides (e.g., Hf-182), which promise interesting applications in astrophysics and other fields. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Vienna, Inst Isotop Res & Nucl Phys, Vienna Environm Res Accelerator, A-1090 Vienna, Austria. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Kurchatov Inst, Inst Nucl Fus, Russian Res Ctr, Moscow 123182, Russia. RP Vockenhuber, C (reprint author), Univ Vienna, Inst Isotop Res & Nucl Phys, Vienna Environm Res Accelerator, Waehringer Guertel 18, A-1090 Vienna, Austria. OI Priller, Alfred/0000-0002-5008-2089 NR 42 TC 95 Z9 100 U1 4 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN 15 PY 2003 VL 223 IS 1-3 BP 713 EP 732 AR PII S1387-3806(02)00944-2 DI 10.1016/S1387-3806(02)00944-2 PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 634WT UT WOS:000180366000062 ER PT J AU Alexander, M Boscaini, E Lindinger, W Mark, TD AF Alexander, M Boscaini, E Lindinger, W Mark, TD TI Membrane introduction proton-transfer reaction mass spectrometry SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE membrane; diffusion coefficient; proton-transfer reaction mass spectrometer; headspace analysis ID VOLATILE ORGANIC-COMPOUNDS; WATER AB The combination of membrane introduction mass spectrometry (MIMS) and proton-transfer reaction mass spectrometry (PTR-MS) is explored. The PTR-MS is used to measure properties of a well-characterized membrane material, poly-dimethylsiloxane (PDMS). It is found that the ability of the PTR-MS to measure absolute concentrations in real-time makes it an ideal tool for the characterization of membrane properties and the interaction of the membrane with multiple organic species. Values for the diffusion coefficients of several molecules are measured and found to be in agreement with literature values. Time modulation of the analyte across the membrane is explored as a method of resolving isobaric interferences for different chemical species. This is demonstrated for acetone and propanal. Finally, the benefit of combining MIMS with PTR-MS is demonstrated by the direct analysis of organic species in the headspace of a hot water solution where the high humidity would not allow analysis using the PTR-MS alone. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Alexander, M (reprint author), Pacific NW Natl Lab, POB 999,K8-93, Richland, WA 99352 USA. RI Mark, Tilmann/J-1650-2014 NR 16 TC 22 Z9 22 U1 4 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN 15 PY 2003 VL 223 IS 1-3 BP 763 EP 770 AR PII S1387-3806(02)00964-8 DI 10.1016/S1387-3806(02)00964-8 PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 634WT UT WOS:000180366000066 ER PT J AU Shukla, AK Futrell, JH AF Shukla, AK Futrell, JH TI Dynamics of hyperthermal energy ion-surface collisions: dissociative and non-dissociative scattering of ethanol cations from a self-assembled monolayer surface of fluorinated alkyl thiol on Au(111) SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE ion-surface collisions; surface-induced dissociation; self-assembled monolayer surface; inelastic collisions; energy transfer; scattering; ethanol ions ID POLYATOMIC IONS; MOLECULAR-IONS; PROTONATED PEPTIDES; FRAGMENTATION; IMPACT; NEUTRALIZATION; CR(CO)(6)(+); SIMULATIONS; ALCOHOLS; CLUSTERS AB Dissociation and inelastic scattering of ethanol molecular ions from self-assembled monolayer (SAM) surface of fluorinated alkyl thiol on an Au (1 1 1) monocrystal have been studied at 28.9 and 52.9 eV collision energies. A single dynamics mechanism for quasi-inelastic scattering was found at both energies. Ions recoil nearly parallel to the surface with very small kinetic energy losses of the order of less than or equal to 2 eV. Dissociation dynamics features for the main dissociation channel, loss of methyl radical, are dramatically different from that of inelastically scattered primary ions and are different at the two collision energies studied. At 28.9 eV two energetically and angularly resolved features are observed, one corresponding to the loss of very large amounts (nearly all) of ion's translational energy and the other appearing to gain energy (superelastic scattering). This dynamics feature is interpreted as delayed dissociation of ions transmitted through the energy analyzer as molecular ions. This implies a lifetime of such excited ions of more than 5 Vs. The same dynamics features are observed at 52.9 eV ion energy except that a second inelastic process begins to compete with the nearly fully inelastic process. Moreover, at this energy the delayed ion dissociation mechanism is the dominant mechanism. The hypothesis that collision of ethanol cations with the SAM surface initially involves collision of the ion with a single end group of the SAM polymer chain provides a useful rationale for the observed dynamics. Support for this hypothesis is provided by Newton diagrams, which summarize momentum conservation relationships in terms of a common center-of-mass, CMeff, which provides a basis for describing scattering mechanisms for this system. Observation of three energetically distinct scattering processes suggests uniquely different ion-surface interactions contributing to surface-induced dissociation of ethanol ions. Preliminary experiments with Ar+ scattered from the same surface exhibit very similar dynamics features to that observed for ethanol cations. Finally, we note that intensities of scattered primary or fragment ions never approach the specular angle at the energies investigated here. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Shukla, AK (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 46 TC 6 Z9 6 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN 15 PY 2003 VL 223 IS 1-3 BP 783 EP 801 AR PII S1387-3806(02)00982-X DI 10.1016/S1387-3806(02)00982-X PG 19 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 634WT UT WOS:000180366000068 ER PT J AU Cahill, DG Ford, WK Goodson, KE Mahan, GD Majumdar, A Maris, HJ Merlin, R Phillpot Sr AF Cahill, DG Ford, WK Goodson, KE Mahan, GD Majumdar, A Maris, HJ Merlin, R Phillpot, SR TI Nanoscale thermal transport SO JOURNAL OF APPLIED PHYSICS LA English DT Review ID MOLECULAR-DYNAMICS SIMULATION; SMALL SEMICONDUCTOR-DEVICES; CHEMICAL-VAPOR-DEPOSITION; ATOMIC-FORCE MICROSCOPE; PHONON HEAT-CONDUCTION; THIN-FILMS; MONTE-CARLO; CARBON NANOTUBES; QUANTUM-WELLS; GAAS/ALAS SUPERLATTICES AB Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid-solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime-experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management of optoelectronic devices have stimulated extensive studies of semiconductor superlattices; agreement between experiment and theory is generally poor. Advances in measurement methods, e.g., the 3omega method, time-domain thermoreflectance, sources of coherent phonons, microfabricated test structures, and the scanning thermal microscope, are enabling new capabilities for nanoscale thermal metrology. (C) 2003 American Institute of Physics. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. Intel Corp, Hillsboro, OR 97124 USA. Stanford Univ, Dept Engn Mech, Stanford, CA 94305 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Calif Berkeley, Dept Engn Mech, Berkeley, CA 94720 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Cahill, DG (reprint author), Univ Illinois, Dept Mat Sci & Engn, 1304 W Green St, Urbana, IL 61801 USA. EM d-cahill@uiuc.edu RI Goodson, Kenneth/C-3545-2011; Phillpot, Simon/J-9117-2012; Cahill, David/B-3495-2014; OI Phillpot, Simon/0000-0002-7774-6535; Merlin, Roberto/0000-0002-5584-0248 NR 171 TC 1507 Z9 1529 U1 95 U2 1060 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 2003 VL 93 IS 2 BP 793 EP 818 DI 10.1063/1.1524305 PG 26 WC Physics, Applied SC Physics GA 630WW UT WOS:000180134200001 ER PT J AU Jones, SC Robinson, MC Gupta, YM AF Jones, SC Robinson, MC Gupta, YM TI Ordinary refractive index of sapphire in uniaxial tension and compression along the c axis SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ALPHA-AL2O3 SINGLE-CRYSTALS; ELASTIC PROPERTIES; INTERFEROMETER; WAVES AB The ordinary refractive index of sapphire, at 532 nm, was measured in single crystals subjected to elastic, uniaxial tensile (and compressive) strain along the c axis in plate impact experiments. The refractive index under both tension and compression was determined from the difference between the uncorrected particle velocities from velocity interferometer measurements and the known particle velocities in symmetric impact experiments. Results to a peak stress of 100 kbar in tension and compression show that the refractive index has an overall monotonic, nonlinear dependence on density that is asymmetric about the ambient density. In compression, the refractive index decreases by an extremely small amount; in contrast, the change is relatively larger in tension. These refractive index results at large tensile stresses suggest that sapphire polarizability is quite different under compression and tension. Compression measurements by themselves can be approximated well by a linear refractive index-density relation, resulting in a window correction (at 532 nm) that is a constant fraction of the true particle velocity up to at least 115 kbar longitudinal stress. The present data also provide high-precision shock velocity results in compression and demonstrate the appropriateness of using second and third order elastic constants for calculating the elastic response of sapphire under uniaxial tensile strain loading. (C) 2003 American Institute of Physics. C1 Washington State Univ, Inst Shock Phys, Pullman, WA 99164 USA. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. RP Jones, SC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 27 TC 25 Z9 27 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 2003 VL 93 IS 2 BP 1023 EP 1031 DI 10.1063/1.1530716 PG 9 WC Physics, Applied SC Physics GA 630WW UT WOS:000180134200033 ER PT J AU Davis, AV Wester, R Bragg, AE Neumark, DM AF Davis, AV Wester, R Bragg, AE Neumark, DM TI Time-resolved photoelectron imaging of the photodissociation of I-2(-) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANGULAR-DISTRIBUTIONS; GROUND-STATE; SPECTROSCOPY; CLUSTERS; ANION; EMISSION; DYNAMICS; IONS AB Time-resolved photoelectron imaging is presented as a new method for the study of anion dynamics. Time-dependent photoelectron energy spectra and angular distributions are extracted from images taken during the dissociation of I-2(-) at 793 nm, and used to follow in detail the dissociation dynamics from 0-1 ps. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Davis, AV (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Neumark, Daniel/B-9551-2009; Wester, Roland/J-6293-2012 OI Neumark, Daniel/0000-0002-3762-9473; Wester, Roland/0000-0001-7935-6066 NR 23 TC 70 Z9 70 U1 1 U2 16 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 2003 VL 118 IS 3 BP 999 EP 1002 DI 10.1063/1.1536617 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634AB UT WOS:000180316700001 ER PT J AU Aguirre, F Pratt, ST AF Aguirre, F Pratt, ST TI Velocity map imaging of the photodissociation of CF3I: Vibrational energy dependence of the recoil anisotropy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLYATOMIC-MOLECULES; REFLECTION PRINCIPLE; TRIATOMIC-MOLECULES; ALKYL IODIDES; A-BAND; 248 NM; 304 NM; SPECTROSCOPY; DYNAMICS; CH3BR AB The photodissociation of jet-cooled CF3I into CF3+I(P-2(3/2)) and CF3+I-*(P-2(1/2)) has been investigated between 304 and 277 nm by using velocity map ion imaging. The two-dimensional images provide detailed information on the partition of available energy into kinetic and internal energy of the photofragments. Vibrational structure with spacing of 695+/-100 cm(-1) is resolved in both I and I* images, indicating excitation of the umbrella mode nu(2) of the CF3 photofragment. The fragment recoil anisotropies beta(I) and beta(I-*) are determined as a function of the excitation wavelength and their variations are interpreted in terms of the crossing between the (3)Q(0) and (1)Q(1) dissociative electronic states. The high-resolution images allow the determination of the variation of the anisotropy parameter beta as a function of the vibrational level of CF3 fragment, and provide a complementary method for the determination of the C-I bond energy. The vibrational dependence of the anisotropy values is discussed in terms of final-state interactions between the CF3 umbrella motion and the C-I dissociation coordinate, as discussed previously by Hennig [J. Chem. Phys. 84, 544 (1986)]. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Aguirre, F (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 34 TC 54 Z9 55 U1 2 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 2003 VL 118 IS 3 BP 1175 EP 1183 DI 10.1063/1.1530582 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634AB UT WOS:000180316700022 ER PT J AU Martin, JE Anderson, RA Williamson, RL AF Martin, JE Anderson, RA Williamson, RL TI Generating strange magnetic and dielectric interactions: Classical molecules and particle foams SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FIELD-STRUCTURED COMPOSITES; BIAXIAL FIELD; SIMULATION; BEHAVIOR; MATRIX AB When a soft magnetic particle suspension is subjected to a vertical uniaxial magnetic field the particles polarize, the positive dipolar interactions causing particle chain formation. If instead an audio-frequency rotating magnetic field is applied in a horizontal plane, the particles experience an average interaction that to first order is a negative dipolar interaction, causing particle sheet formation in the biaxial field plane. When a vertical uniaxial field and a horizontal biaxial field are simultaneously applied with the field amplitudes balanced, the positive and negative dipolar interactions cancel to first order, and one might expect no dipolar interactions at all. But in this balanced triaxial field an isotropic second-order dipolar interaction of surprising magnitude remains. This triaxial interaction can be attractive or repulsive, and exhibits strong many-body interactions that lead to a variety of unexpected effects, including stable clusters with molecular geometries, the emergence of a particle foam, and the production of vortices in the fluid. By manipulating the triaxial field, a variety of particle structures can be made that cannot be produced by any other known means. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Martin, JE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 53 Z9 54 U1 2 U2 12 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 2003 VL 118 IS 3 BP 1557 EP 1570 DI 10.1063/1.1528892 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634AB UT WOS:000180316700063 ER PT J AU Song, JM Mobley, J Vo-Dinh, T AF Song, JM Mobley, J Vo-Dinh, T TI Detection of bacterial pathogen DNA using an integrated complementary metal oxide semiconductor microchip system with capillary array electrophoresis SO JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES LA English DT Article DE complementary metal oxide semiconductor microchip; polymerase chain reaction; DNA; poly(vinylpyrrolidone) ID TOXIGENIC ESCHERICHIA-COLI; OPTIMIZATION; DEVICE; TOXIN AB In this paper, we show an integrated complementary metal oxide semiconductor (CMOS)-based microchip system with capillary array electrophoresis (CAE) for the detection of bacterial pathogen amplified by polymerase chain reaction (PCR). In order to demonstrate the efficacy of PCR reaction for the heat-labile toxin producing enterotoxigenic Escherichia coli (E. coli), which causes cholera-like diarrhea, 100 bp DNA ladders. were injected along with the PCR product. Poly(vinylpyrrolidone) (PVP) was used as the separation medium and provided separation resolution which was adequate for the identification of PCR product. The miniaturized integrated CMOS microchip system with CAE has excellent advantages over conventional instrumental systems for analysis of bacterial pathogens such as compactness, low cost, high speed, and multiplex capability. Furthermore, the miniaturized integrated CMOS microchip system should be compatible with a variety of microfabricated devices that aim at more rapid and high-throughput analysis. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Life Sci, Adv Biomed Sci & Technol Grp, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Div Life Sci, Adv Biomed Sci & Technol Grp, POB 2008, Oak Ridge, TN 37831 USA. NR 30 TC 21 Z9 23 U1 0 U2 1 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 15 PY 2003 VL 783 IS 2 BP 501 EP 508 AR PII S1570-0232(02)00747-X PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 634FX UT WOS:000180330300020 ER PT J AU Lenhart, JL Dunkers, JP van Zanten, JH Parnas, RS AF Lenhart, JL Dunkers, JP van Zanten, JH Parnas, RS TI Characterization of sizing layers and buried polymer/sizing/substrate interfacial regions using a localized fluorescent probe SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE fluorescence; interface; interphase; composite; epoxy; coupling agent ID SILANE COUPLING AGENT; ADSORPTION BEHAVIOR; SILICA; SURFACE; GLASS; STRENGTH; OXIDE AB A novel technique is described to investigate buried polymer/sizing/substrate interfacial regions, in situ, by localizing a fluorescent probe molecule in the sizing layer. Epoxy functional silane coupling agent multilayers were deposited on glass microscope cover slips and doped with small levels of a fluorescently labeled silane coupling agent (FLSCA). The emission of the grafted FLSCA was dependent on the silane layer thickness, showing blue-shifted emission with decreasing thickness. The fluorescent results suggest that thinner layers were more tightly bound to the glass surface. The layers were also characterized by scanning electron microscopy, contact angle, and thermogravimetric analysis (TGA). When the FLSCA-doped silane layers were immersed in epoxy resin, a blue shift in emission occurred during resin cure, indicating the potential to study interfacial chemistry, in situ. Thicker silane layers exhibited smaller fluorescence shifts during cure, suggesting incomplete resin penetration into the thickest silane layers. (C) 2003 Elsevier Science (USA). All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. RP Lenhart, JL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 37 TC 4 Z9 4 U1 1 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD JAN 15 PY 2003 VL 257 IS 2 BP 398 EP 407 AR PII S0021-9797(02)00035-8 DI 10.1016/S0021-9797(02)00035-8 PG 10 WC Chemistry, Physical SC Chemistry GA 644YA UT WOS:000180947700028 PM 16256496 ER PT J AU Brown, S Head-Gordon, T AF Brown, S Head-Gordon, T TI Cool walking: A new Markov chain Monte Carlo sampling method SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article DE Metropolis Monte Carlo; ergodicity; detailed balanced simulation; sampling ID SIMULATION; CLUSTERS; SCHEME; WATER AB Effective relaxation processes for difficult systems like proteins or spin glasses require special simulation techniques that permit barrier crossing to ensure ergodic sampling. Numerous adaptations of the venerable Metropolis Monte Carlo (MMC) algorithm have been proposed to improve its sampling efficiency, including various hybrid Monte Carlo (HMC) schemes, and methods designed specifically for overcoming quasi-ergodicity problems such as Jump Walking (J-Walking), Smart Walking (S-Walking), Smart Darting, and Parallel Tempering. We present an alternative to these approaches that we call Cool Walking, or C-Walking. In C-Walking two Markov chains, are propagated in tandem, one at a high (ergodic) temperature and the other at a low temperature, Nonlocal trial moves for the low temperature walker are generated by first sampling from the high-temperature distribution, then performing a statistical quenching process on the sampled configuration to generate a C-Walking jump move, C-Walking needs only one high-temperature walker, satisfies detailed balance. and offers the important practical advantage that the high and low-temperature walkers can be run in tandem with minimal degradation of sampling due to the presence of correlations. To make the C-Walking approach more suitable to real problems we decrease the required number of cooling steps by attempting to jump at intermediate temperatures during cooling. We further reduce the number of cooling steps by utilizing "windows" of states when jumping, which improves acceptance ratios and lowers the average number of cooling steps. We present C-Walking results with comparisons to J-Walking, S-Walking. Smart Darting. and Parallel Tempering on a one-dimensional rugged potential energy surface in which the exact normalized probability distribution is known. C-Walking shows superior sampling as judged by two ergodic measures. (C) 2002 Wiley Periodicals, Inc. C1 Univ Calif Berkeley, Dept Bioengn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci & Div, Berkeley, CA 94720 USA. RP Head-Gordon, T (reprint author), Univ Calif Berkeley, Dept Bioengn, Berkeley, CA 94720 USA. RI Head-Gordon, Teresa/E-5818-2011 NR 22 TC 30 Z9 30 U1 1 U2 4 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0192-8651 J9 J COMPUT CHEM JI J. Comput. Chem. PD JAN 15 PY 2003 VL 24 IS 1 BP 68 EP 76 DI 10.1002/jcc.10181 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 632RQ UT WOS:000180237000007 PM 12483676 ER PT J AU Raty, JY Gaspard, JP Bichara, C AF Raty, JY Gaspard, JP Bichara, C TI Properties of molten Ge chalcogenides: an ab initio molecular dynamics study SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 5th Liquid Matter Conference CY SEP 14-18, 2002 CL CONSTANCE, GERMANY ID LIQUID PHASE-TRANSITION; TE ALLOYS; SEMICONDUCTORS; TELLURIUM AB In this study, we perform first-principles molecular dynamics simulations of the eutectic alloy Ge15Te85 at five different densities and temperatures. We obtain structures in agreement with the available diffraction data and obtain a new view of the molten Ge chalcogenides. We show that the anomalous volume contraction observed in the liquid 30 K above the eutectic temperature corresponds to a significant change of the Ge-Te partial structure factor. The detailed structural analysis shows that volume variations observed upon melting in Ge15Te85, as in liquid, GeSe and GeTe, can be explained in terms of the competition between two types of local environment of the germanium atoms. A symmetrical coordination octahedron is entropically favoured at high temperature, while an asymmetrical octahedron resulting from the local manifestation of the Peierls distortion is electronically favoured at lower temperatures. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Liege, B-4000 Sart Tilman Par Liege, Belgium. CNRS, CRMC2, F-13288 Marseille, France. RP Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 23 TC 8 Z9 8 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 15 PY 2003 VL 15 IS 1 SI SI BP S167 EP S173 AR PII S0953-8984(03)55420-0 DI 10.1088/0953-8984/15/1/321 PG 7 WC Physics, Condensed Matter SC Physics GA 669HX UT WOS:000182346800022 ER PT J AU Huynh, MHV Witham, LM Lasker, JM Wetzler, M Mort, B Jameson, DL White, PS Takeuchi, KJ AF Huynh, MHV Witham, LM Lasker, JM Wetzler, M Mort, B Jameson, DL White, PS Takeuchi, KJ TI Aerobic oxidation of methyl p-tolyl sulfide catalyzed by a remarkably labile heteroscorpionate Ru(II)-aqua complex, fac-[Ru-II(H2O)(dpp)(tppm)](2+) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RUTHENIUM(II)-CATALYZED THIOETHER OXIDATION; LIGAND SUBSTITUTION; SELECTIVE OXIDATION; SULFOXIDES; OXYGEN; PORPHYRIN; ALCOHOLS; CRYSTAL; METALS; SULFUR C1 SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. Los Alamos Natl Lab, Div Chem, C SIC Grp, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Dynam Experimentat Div, HE Sci & Technol Grp, Los Alamos, NM 87545 USA. Gettysburg Coll, Dept Chem, Gettysburg, PA 17325 USA. RP Huynh, MHV (reprint author), SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. EM huynh@lanl.gov; takeuchi@nsm.buffalo.edu NR 37 TC 40 Z9 40 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 15 PY 2003 VL 125 IS 2 BP 308 EP 309 DI 10.1021/ja0124111 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 633YE UT WOS:000180311800001 PM 12517123 ER PT J AU Liu, TB AF Liu, TB TI An unusually slow self-assembly of inorganic ions in dilute aqueous solution SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLYBDENUM-OXIDE; SPHERES C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Liu, TB (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Liu, Tianbo/D-8915-2017 OI Liu, Tianbo/0000-0002-8181-1790 NR 7 TC 93 Z9 94 U1 2 U2 11 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 15 PY 2003 VL 125 IS 2 BP 312 EP 313 DI 10.1021/ja028933d PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 633YE UT WOS:000180311800003 PM 12517125 ER PT J AU Chabanas, M Baudouin, A Coperet, C Basset, JM Lukens, W Lesage, A Hediger, S Emsley, L AF Chabanas, M Baudouin, A Coperet, C Basset, JM Lukens, W Lesage, A Hediger, S Emsley, L TI Perhydrocarbyl Re-VII complexes: Comparison of molecular and surface complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ALKYLIDENE-ALKYLIDYNE COMPLEXES; X-RAY STRUCTURE; ORGANOMETALLIC CHEMISTRY; OLEFIN METATHESIS; C-H; RHENIUM; CATALYST; LIGANDS; BONDS AB The molecular complex [Re(equivalent toC(t)Bu)(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)2] (1) reacts with a silica partially dehydroxylated at 700 degreesC to give syn-2, [(equivalent toSiO)Re(equivalent toC(t)Bu)(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)], as a single isomer according to mass-balance analysis, IR, and solid-state NMR spectroscopy. 1 D and 2D solid-state NMR.(HETCOR and long-range HETCOR) on a C-13-labeled-2 has allowed us to observe the chemical shifts of all carbons (including those that are not labeled) and ascertain their assignments. Moreover, EXAFS data are consistent with the presence of two carbons at a relatively short distance (1.79 Angstrom), which cannot be cleconvoluted, but which are consistent with the presence of alkylidene and alkylidyne carbons along with two other first neighbors at a longer distance (2.01 Angstrom), the alkyl carbon and the 0 atom by which the Re is attached to the surface. Moreover, the data also suggest the presence of a siloxane bridge of the silica surface at 2.4 Angstrom in the coordination sphere of the Re center. Thermal and photochemical treatment allow us to observe the anti isomer, which was also fully characterized by 1D and 2D solid-state NMR. This behavior parallels the reactivity of molecular Re complexes, and their respective H-1 and C-13 chemical shifts match those of the corresponding molecular analogues syn- and anti-2m and n. Finally, the grafting of 1 onto silica involves the reaction of both the alkyl and the alkylidene ligand with an equiprobability, leaving the alkylidyne as a spectator ligand. Noteworthy is the formation of 2 [(equivalent toSiO)Re(equivalent toC(t)Bu)(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)], rather than the corresponding trisneopentyl-neopentylidyne Re complex, monografted on silica, [(equivalent toSiO)Re(equivalent toC(t)Bu)((CH2Bu)-Bu-t)(3)], which would have been expected from the reactivity of I with various molecular Bronsted acids and which also suggests that a proximal siloxane bridge forces the alpha-H abstraction process, leading to syn-2a. C1 CNRS, UMR 9983, Lab Chim Organomet Surface, ESCPE Lyon, F-69626 Villeurbanne, France. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Ecole Normale Super Lyon, Lab Rech Conventionne, CEA 23V, Lab Stereochim & Interact Mol,UMR 5532,CNRS,ENS, F-69365 Lyon, France. RP Coperet, C (reprint author), CNRS, UMR 9983, Lab Chim Organomet Surface, ESCPE Lyon, 43 Bd 11 Novembre 1918, F-69626 Villeurbanne, France. EM coperet@cpe.fr; basset@cpe.fr RI Emsley, Lyndon/C-6108-2008; Baudouin, Anne/B-2228-2010; OI Emsley, Lyndon/0000-0003-1360-2572; basset, jean marie/0000-0003-3166-8882 NR 25 TC 79 Z9 80 U1 1 U2 10 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 15 PY 2003 VL 125 IS 2 BP 492 EP 504 DI 10.1021/ja020136s PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 633YE UT WOS:000180311800041 PM 12517163 ER PT J AU Unal, O Dayal, V AF Unal, O Dayal, V TI Interlaminar shear strength measurement of ceramic composites by asymmetric four point bend shear test SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE shear strength; test method; composite ID SPECIMENS; JOINTS AB Asymmetric four-point bend test is used for the measurement of interlaminar shear strength of ceramic composite. It is shown by finite element analysis that the method provides a reasonably good approximation to a constant shear state in the sample. The use of very small samples makes this method very attractive, especially during the material development stage, when larger samples may be impractical or impossible to fabricate. This technique is also useful when bigger samples would be prohibitively expensive or impractical. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Dept Aerosp Engn & Mech, Ames, IA 50011 USA. Ames Lab, Met & Ceram Program, Ames, IA 50010 USA. RP Dayal, V (reprint author), Iowa State Univ Sci & Technol, Dept Aerosp Engn & Mech, 2271 Howe Hall, Ames, IA 50011 USA. NR 13 TC 10 Z9 10 U1 0 U2 3 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 2003 VL 340 IS 1-2 BP 170 EP 174 AR PII S0921-5093(02)00168-5 DI 10.1016/S0921-5093(02)00168-5 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 615TC UT WOS:000179261900018 ER PT J AU Schneibel, JH Sekhar, JA AF Schneibel, JH Sekhar, JA TI Microstructure and properties of MoSi2-MoB and MoSi2-Mo5Si3 molybdenum silicides SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE intermetallic; silicide; MoSi2; mechanical properties; oxidation ID GRAIN-SIZE DEPENDENCE; FRACTURE ENERGY; COMPOSITES; OXIDATION; BEHAVIOR; CERAMICS AB MoSi2-based intermetallics containing different volume fractions of MOB or Mo5Si3 were fabricated by hot-pressing MoSi2, MOB, and Mo5Si3 powders in vacuum. Both classes of alloys contained approximately 5 vol.% of dispersed silica phase. Additions of MoB or Mo5Si3 caused the average grain size to decrease. The decrease in the grain size was typically accompanied by an increase in flexure strength, a decrease in the room temperature fracture toughness, and a decrease in the hot strength (compressive creep strength) measured around 1200 degreesC, except when the Mo5Si3 effectively became the major phase. Oxidation measurements on the two classes of alloys were carried out in air. Both classes of alloys were protected from oxidation by an in-situ adherent scale that formed on exposure to high temperature. The scale, although not analyzed in detail, is commonly recognized in MoSi2 containing materials as consisting mostly of SiO2. The MOB containing materials showed an increase in the scale thickness and the cyclic oxidation rate at 1400 degreesC when compared with pure MoSi2. However, in contrast with the pure MoSi2 material, oxidation at 1400 degreesC began with a weight loss followed by a weight gain and the formation of the protective silica layer. The Mo5Si3 containing materials experienced substantial initial weight losses followed by regions of small weight changes. Overall, the MoB and Mo5Si3 additions to MoSi2 tended to be detrimental for the mechanical and oxidative properties. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Micropyret Heaters Int Inc, Cincinnati, OH 45215 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. RP Schneibel, JH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 13 TC 19 Z9 24 U1 2 U2 11 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 2003 VL 340 IS 1-2 BP 204 EP 211 AR PII S0921-5093(02)00193-4 DI 10.1016/S0921-5093(02)00193-4 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 615TC UT WOS:000179261900022 ER PT J AU Kaatz, FH Siegal, MP Overmyer, DL Provencio, PP Jackson, JL AF Kaatz, FH Siegal, MP Overmyer, DL Provencio, PP Jackson, JL TI Diameter control and emission properties of carbon nanotubes grown using chemical vapor deposition SO MATERIALS SCIENCE & ENGINEERING C-BIOMIMETIC AND SUPRAMOLECULAR SYSTEMS LA English DT Article; Proceedings Paper CT Spring Meeting of the European-Materials-Research-Society (E-MRS) CY JUN 18-21, 2002 CL STRASBOURG, FRANCE SP European Mat Res Soc DE carbon nanotubes; electron emission ID HEXAGONAL PORE ARRAYS; FIELD-EMISSION; ANODIC ALUMINA; EMITTERS AB We grow multiwalled carbon nanotubes (CNTs) via thermal chemical vapor deposition from a sputtered 4-nm-thick nickel catalyst film on a tungsten-coated silicon substrate. CNTs grow from a mixture of nitrogen and acetylene gases at temperatures ranging from 630 to 790 degreesC, resulting in CNT outer diameters of 5-350 nm. CNT diameters increase exponentially with temperature. These results define regimes for template growth fabricated in catalytically active anodized aluminum oxide (AAO) with controlled pinhole sizes ranging from 10 to 50 nm. We measure a threshold electron emission field of 3 V/mum and a field enhancement factor beta = 5230 on randomly oriented 10-nm diameter CNTs. (C) 2002 Elsevier Science B.V All rights reserved. C1 Mesalands Community Coll, Tucumcari, NM 88401 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mesalands Community Coll, 911 S 10th St, Tucumcari, NM 88401 USA. EM forrestk@mesalands.edu NR 20 TC 20 Z9 22 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0928-4931 J9 MAT SCI ENG C-BIO S JI Mater. Sci. Eng. C-Biomimetic Supramol. Syst. PD JAN 15 PY 2003 VL 23 IS 1-2 BP 141 EP 144 AR PII S0928-4931(02)00243-6 DI 10.1016/S0928-4931(02)00243-6 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 638YP UT WOS:000180600800026 ER PT J AU Reyes-Lopez, M Mendez-Tenorio, A Maldonaldo-Rodriguez, R Doktycz, MJ Fleming, JT Beattie, KL AF Reyes-Lopez, M Mendez-Tenorio, A Maldonaldo-Rodriguez, R Doktycz, MJ Fleming, JT Beattie, KL TI Fingerprinting of prokaryotic 16S rRNA genes using oligodeoxyribonucleotide microarrays and virtual hybridization SO NUCLEIC ACIDS RESEARCH LA English DT Article ID NEAREST-NEIGHBOR THERMODYNAMICS; TETHERED OLIGONUCLEOTIDE PROBES; DOT-T MISMATCHES; DNA; ALGINATE; SYSTEM; NMR AB An oligonucleotide microarray hybridization system to differentiate microbial species was designed and tested. Seven microbial species were studied, including one Bacillus and six Pseudomonas strains. DNA sequences near the 5' end of 16S rRNA genes were aligned and two contiguous regions of high variability, flanked by highly conserved sequences, were found. The conserved sequences were used to design PCR primers which efficiently amplified these polymorphic regions from all seven species. The amplicon sequences were used to design 88 9mer hybridization probes which were arrayed onto glass slides. Single-stranded, fluorescence-tagged PCR products were hybridized to the microarrays at 15degreesC. The experimental results were compared with the DeltaGdegrees values for all matched and mismatched duplexes possible between the synthetic probes and the 16S target sequences of the seven test species, calculated using a 'virtual hybridization' software program. Although the observed hybridization patterns differed significantly from patterns predicted solely on the basis of perfect sequence matches, a unique hybridization fingerprint was obtained for each of the species, including closely related Pseudomonas species, and there was a reasonable correlation between the intensity of observed hybridization signals and the calculated DeltaGdegrees values. The results suggest that both perfect and mismatched pairings can contribute to microbial identification by hybridization fingerprinting. C1 IPN, Lab Tecnol DNA, Escuela Nacl Ciencias Biol, Mexico City 11340, DF, Mexico. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. RP Maldonaldo-Rodriguez, R (reprint author), IPN, Lab Tecnol DNA, Escuela Nacl Ciencias Biol, Prol Carpio & Plan Ayala S-N, Mexico City 11340, DF, Mexico. EM romaldodr@hotmail.com RI Doktycz, Mitchel/A-7499-2011; Reyes-Lopez, Miguel Angel/D-9308-2011 OI Doktycz, Mitchel/0000-0003-4856-8343; NR 35 TC 23 Z9 25 U1 2 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JAN 15 PY 2003 VL 31 IS 2 BP 779 EP 789 DI 10.1093/nar/gkg132 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 647FE UT WOS:000181081500030 PM 12527788 ER PT J AU Je, JH You, H Cullen, WG Maroni, VA Ma, B Koritala, RE Rupich, MW Thieme, CLH AF Je, JH You, H Cullen, WG Maroni, VA Ma, B Koritala, RE Rupich, MW Thieme, CLH TI Microstructure of RE2O3 layers on cube textured Ni substrates SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE RE2O3/Ni; coincidence site density; extended domain matching; cube textured Ni substrates ID CRITICAL-CURRENT DENSITY; YBCO COATED CONDUCTORS; SUPERCONDUCTING TAPES; BUFFER LAYERS; FILMS; EVAPORATION; DEPOSITION; GROWTH AB We investigated the structure and alignment of epitaxial Y2O3 and Gd2O3 films on cube textured Ni(001) substrates and used the findings to develop a general interpretation of the morphology of RE,03 films (RE = Y or a rare earth element) on cube textured nickel and nickel-based alloys. The [10 0] axis of RE2O3 oxides mostly prefers aligning to the Ni[0 0 1] axis, while the [0 0 1] axis is aligned with the Ni[0 0 1] axis. This (2root2 x 2root2)R45degrees extended domain matching (EDM) seems to be favored by a high coincidence site density (CSD) with the Ni(0 0 1) surface atoms, in spite of the existence of large lattice mismatches to Ni(0 0 1). Meanwhile a 3 x 3 EDM is not favored on Ni(O 0 1), in spite of the relatively small lattice mismatch to Ni(O 0 1), because of the existence of a low CSD. The broad mosaic distributions of RE2O3(0 0 1) grains (6-9degrees full-width at half-maximum) indicate that RE,03 layers prefer growing along the Ni(O 0 1) planes rather than along the Ni surface, a condition presumably induced by the favorable energetics for EDM. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. POSTECH, Dept Mat Sci & Engn, Pohang 790784, South Korea. Amer Supercond, Westborough, MA 01581 USA. RP You, H (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Koritala, Rachel/F-1774-2011; Ma, Beihai/I-1674-2013; You, Hoydoo/A-6201-2011 OI Ma, Beihai/0000-0003-3557-2773; You, Hoydoo/0000-0003-2996-9483 NR 16 TC 4 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JAN 15 PY 2003 VL 384 IS 1-2 BP 54 EP 60 AR PII s0921-4534(02)01982-2 DI 10.1016/S0921-4534(02)01982-2 PG 7 WC Physics, Applied SC Physics GA 633VU UT WOS:000180305800007 ER PT J AU Olson, CJ Reichhardt, C Scalettar, RT Zimanyi, GT Gronbech-Jensen, N AF Olson, CJ Reichhardt, C Scalettar, RT Zimanyi, GT Gronbech-Jensen, N TI Disordering transitions in vortex matter: peak effect and phase diagram SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID FLUX-LINE-LATTICE; T-C SUPERCONDUCTORS; LAYERED SUPERCONDUCTOR; MELTING TRANSITION; BI2SR2CACU2O8; VORTICES; CRYSTAL; DYNAMICS; MODEL; YBA2CU3O7-DELTA AB Using numerical simulations of magnetically interacting vortices in disordered layered superconductors we obtain the static vortex phase diagram as a function of magnetic field and temperature. For increasing field or temperature, we find a transition from ordered straight vortices to disordered decoupled vortices. This transition is associated with a peak effect in the critical current. For samples with increasing disorder strength the field at which the decoupling occurs decreases. Long range, nonlinear interactions in the c-axis are required to observe the effect. (C) 2002 Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Lawrence Berkeley Natl Lab, NERSC, Berkeley, CA 94720 USA. RP Olson, CJ (reprint author), Los Alamos Natl Lab, Div Theoret, T-12,MS B268, Los Alamos, NM 87545 USA. EM olson@t12.lanl.gov NR 40 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JAN 15 PY 2003 VL 384 IS 1-2 BP 143 EP 148 AR PII S0921-4534(02)01799-9 DI 10.1016/S0921-4534(02)01799-9 PG 6 WC Physics, Applied SC Physics GA 633VU UT WOS:000180305800018 ER PT J AU Beleggia, M Fazzini, PF Merli, PG Pozzi, G AF Beleggia, M Fazzini, PF Merli, PG Pozzi, G TI Influence of charged oxide layers on TEM imaging of reverse-biased p-n junctions SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-MICROSCOPY; HOLOGRAPHY; MODEL AB Experimental observations of reverse-biased p-n junctions by means of the out-of-focus method display features which cannot be interpreted within the standard theory of an abrupt p-n junction. In order to reconcile theory and experiment it is necessary to introduce an active role of the specimen surfaces. In particular it is shown how the introduction of a suitable surface density charge at the interface between the silicon and oxide created after the thinning process allows us to explain the main features of the experimental results. Moreover, some questions left unanswered by previous observations made by Lorentz and holographic methods will be clarified. The results point out that oxide charging cannot be overlooked and should be properly taken into account whenever semiconductor devices are observed by transmission electron microscopy techniques, especially when these methods are employed for the analysis of dopant diffusion in submicron devices. C1 Univ Bologna, Dept Phys, I-40127 Bologna, Italy. Univ Bologna, INFM, I-40127 Bologna, Italy. CNR, IMM, Sez Bologna, I-40129 Bologna, Italy. RP Beleggia, M (reprint author), Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. RI FAZZINI, Pier Francesco/B-2645-2012 OI FAZZINI, Pier Francesco/0000-0002-4307-6481 NR 23 TC 22 Z9 23 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 4 AR 045328 DI 10.1103/PhysRevB.67.045328 PG 4 WC Physics, Condensed Matter SC Physics GA 646CA UT WOS:000181016200060 ER PT J AU de Dood, MJA Gralak, B Polman, A Fleming, JG AF de Dood, MJA Gralak, B Polman, A Fleming, JG TI Superstructure and finite-size effects in a Si photonic woodpile crystal SO PHYSICAL REVIEW B LA English DT Article ID BAND-GAP; DIFFRACTION GRATINGS; INFRARED WAVELENGTHS AB The reflectivity of finite-thickness silicon photonic woodpile structures was measured in the wavelength range from 0.9 to 1.7 mum. Polarization and surface orientation dependent measurements were performed as function of angle of incidence and the data were compared with rigorous calculations for the finite structure. Due to the finite size, the reflectivity near the stop gap edge is strongly orientation and polarization dependent. Clear stop gaps can be identified and good agreement with calculations is found. Outside the stop gap region, Fabry-Perot type resonances are observed that are related to the finite thickness of the photonic crystal. In the stop gap region clear dips are found that are not reproduced in the calculation for perfect, finite-size crystals. These are due an irregularity in the pitch of the woodpile structure as observed in electron microscopy images. This irregularity can be described in terms of a superstructure that introduces additional bands due to zone folding of the bandstructure. Calculations based on the superstructure successfully reproduce the major features in the experimental data. C1 FOM, Inst Atom & Mol Phys, NL-1098 SJ Amsterdam, Netherlands. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP de Dood, MJA (reprint author), Univ Calif Santa Barbara, Calif Nanosyst Inst, Santa Barbara, CA 93106 USA. RI Polman, Albert/D-1490-2011; de Dood, Michiel/A-9839-2012 OI de Dood, Michiel/0000-0002-4585-4814 NR 22 TC 10 Z9 10 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035322 DI 10.1103/PhysRevB.67.035322 PG 8 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800084 ER PT J AU Feibelman, PJ AF Feibelman, PJ TI Vibrations of a water adlayer on Ru(0001) SO PHYSICAL REVIEW B LA English DT Article ID INITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; AUGMENTED-WAVE METHOD; ULTRASOFT PSEUDOPOTENTIALS; BASIS-SET; METALS; TRANSITION; SURFACES; EXCHANGE; BILAYER AB Ab initio vibration spectra have been calculated for two-dimensional arrangements of intact and partially dissociated water molecules adsorbed on Ru(0001) and for an ice-Ih crystal. Dissociation of the non-hydrogen-bonding O-D bonds of a heavy-water bilayer on Ru(0001) eliminates the highest-energy O-D stretch feature, just as is seen in Denzler 's (unpublished) sum frequency generation observations. Reduced zero-point energy, a consequence of replacing O-D stretch vibrations with softer Ru-D modes, stabilizes partially dissociated adlayers relative to adsorption structures made purely of intact water molecules. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Feibelman, PJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 33 TC 46 Z9 46 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035420 DI 10.1103/PhysRevB.67.035420 PG 9 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800112 ER PT J AU Fournee, V Cai, TC Ross, AR Lograsso, TA Evans, JW Thiel, PA AF Fournee, V Cai, TC Ross, AR Lograsso, TA Evans, JW Thiel, PA TI Nucleation and growth of Ag films on a quasicrystalline AlPdMn surface SO PHYSICAL REVIEW B LA English DT Article ID ENERGY-ELECTRON DIFFRACTION; QUASI-CRYSTAL; FIVEFOLD SURFACE; ISLAND-SIZE; AL70PD21MN9; ORIGINS; AL AB Nucleation and growth of thin films of Ag on the fivefold surface of an Al72Pd19.5Mn8.5 icosahedral quasicrystal is studied with scanning-tunneling microscopy. For low coverages, flux-independent island nucleation is observed involving adatom capture at "traps." With increasing coverage, islands start growing vertically, but then spread, and ultimately form hexagonal nanocrystals. These have fcc symmetry and pyramidlike multilayer stacking along the [111] direction. The constituent hexagonal islands have five different orientations, rotated by 2pi/5, thus reflecting the symmetry of the substrate. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Math, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. EM thiel@ameslab.gov NR 24 TC 51 Z9 51 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 033406 DI 10.1103/PhysRevB.67.033406 PG 4 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800023 ER PT J AU Hsu, L McCluskey, MD Haller, EE AF Hsu, L McCluskey, MD Haller, EE TI Pressure dependence of donor excitation spectra in AlSb SO PHYSICAL REVIEW B LA English DT Article ID HYDROSTATIC-PRESSURE; GALLIUM-ARSENIDE; ZINCBLENDE SEMICONDUCTORS; RAMAN-SCATTERING; OPTICAL PHONONS; IMPURITY LEVELS; SOLID NITROGEN; SHALLOW DONOR; DEEP LEVELS; GAAS AB We have investigated the behavior of ground- to bound excited-state electronic transitions of Se and Te donors in AlSb as a function of hydrostatic pressure. Using broadband far-infrared Fourier transform spectroscopy, we observe qualitatively different behaviors of the electronic transition energies of the two donors. While the pressure derivative of the Te transition energy is small and constant, as might be expected for a shallow donor, the pressure derivatives of the Se transition energies are quadratic and large at low pressures, indicating that Se is actually a deep donor. In addition, at pressures between 30 and 50 kbar, we observe evidence of an anticrossing between one of the selenium electronic transitions and a two-phonon mode. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. Washington State Univ, Inst Shock Phys, Pullman, WA 99164 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Hsu, L (reprint author), Univ Minnesota, Gen Coll, Minneapolis, MN 55455 USA. NR 49 TC 0 Z9 0 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035209 DI 10.1103/PhysRevB.67.035209 PG 8 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800060 ER PT J AU Ismail Zhang, JD Matzdorf, R Kimura, T Tokura, Y Plummer, EW AF Ismail Zhang, JD Matzdorf, R Kimura, T Tokura, Y Plummer, EW TI Surface lattice dynamics of layered transition metal oxides: Sr2RuO4 and La0.5Sr1.5MnO4 SO PHYSICAL REVIEW B LA English DT Article ID MANGANESE PEROVSKITES; CHARGE; PHYSICS; MANGANITES; SUPERCONDUCTIVITY; LA0.65SR0.35MNO3; LA1/2SR3/2MNO4; ELECTRONS AB Momentum resolved inelastic electron scattering has been used to study the surface lattice dynamics of two layered isostructural perovskite crystals (Sr2RuO4 and La0.5Sr1.5MnO4), two materials with different physical properties. There were three surface optical phonons observed with the energies at 30.0, 50.0, and 75.0 meV with a shoulder appearing at 67.5 meV for Sr2RuO4 and at 26.0, 56.5, and 78.5 meV for La0.5Sr1.5MnO4. In the K2NiF4-type structure, these phonons are associated with the La/Sr vibrational (external), Mn-O-Mn (Ru-O-Ru) bending, and MnO6 (RuO6) stretching modes, respectively. The observed surface phonons, especially for breathing and stretching modes, are at significantly higher energies than the corresponding modes in the bulk, which are directly associated with the relative reduction of out-of-plane Mn-O/Ru-O bond lengths at the surfaces. The line shapes of the quasielastic scattering peaks reflects the surface conductivity of Sr2RuO4 and the insulating behavior of La0.5Sr1.5MnO4. For Sr2RuO4, the large line width of the external mode is attributed to nonequivalent Sr vibrational sites due to the surface reconstruction. For La0.5Sr1.5MnO4, the broad character of both the bending and the stretching modes results from surface electronic inhomogeneities. In contrast to the bulk, the absence of phonon restructuring in the observed temperature range suggests that the long-range charge/orbital ordering transition occurring in the bulk may not take place on the surface, probably correlated with stiffening of observed optical phonons at the surface. C1 Florida Int Univ, Dept Phys, Miami, FL 33199 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Wurzburg, D-97074 Wurzburg, Germany. Univ Tokyo, Dept Appl Phys, Tokyo 1130033, Japan. AIST, Correlated Electron Res Ctr, Tsukuba, Ibaraki 3050046, Japan. RP Zhang, JD (reprint author), Florida Int Univ, Dept Phys, Miami, FL 33199 USA. RI Tokura, Yoshinori/C-7352-2009 NR 27 TC 1 Z9 2 U1 2 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035407 DI 10.1103/PhysRevB.67.035407 PG 9 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800099 ER PT J AU Karathanos, AT Perakis, IE Fromer, NA Chemla, DS AF Karathanos, AT Perakis, IE Fromer, NA Chemla, DS TI Ultrafast nonlinear optical response of strongly correlated systems: Dynamics in the quantum Hall effect regime SO PHYSICAL REVIEW B LA English DT Article ID FERMI-EDGE SINGULARITY; 2-DIMENSIONAL ELECTRON-GAS; HIGH MAGNETIC-FIELDS; MANY-BODY; TRANSFORMATION APPROACH; COULOMB CORRELATIONS; VIRTUAL EXCITATION; LANDAU-LEVEL; SEMICONDUCTORS; PHOTOLUMINESCENCE AB We present a theoretical formulation of the coherent ultrafast nonlinear optical response of a strongly correlated system and discuss an example where the Coulomb correlations dominate. We separate out the correlated contributions to the third-order nonlinear polarization, and identify non-Markovian dephasing effects coming from the noninstantaneous interactions and propagation in time of the collective excitations of the many-body system. We discuss the signatures, in the time and frequency dependence of the four-wave-mixing (FWM) spectrum, of the inter-Landau level magnetoplasmon excitations of the two-dimensional electron gas in a perpendicular magnetic field. We predict a resonant enhancement of the lowest Landau-level (LL) FWM signal, a strong non-Markovian dephasing of the next LL magnetoexciton (X), a symmetric FWM temporal profile, and strong oscillations as a function of time delay, of quantum kinetic origin. We show that the correlation effects can be controlled experimentally by tuning the central frequency of the optical excitation between the two lowest LL's. C1 Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Karathanos, AT (reprint author), Univ Crete, Dept Phys, POB 2208, Iraklion 71003, Crete, Greece. RI Perakis, Ilias/G-9186-2011 NR 57 TC 14 Z9 14 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035316 DI 10.1103/PhysRevB.67.035316 PG 19 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800078 ER PT J AU Li, JB Wang, LW AF Li, JB Wang, LW TI Energy levels of isoelectronic impurities by large scale LDA calculations SO PHYSICAL REVIEW B LA English DT Article ID V SEMICONDUCTORS; CHEMICAL TRENDS; QUANTUM DOTS; BAND OFFSETS; ALLOYS; GAASN; GAN; LUMINESCENCE; ORBITALS AB Isoelectronic impurity states are localized states induced by stoichiometric single atom substitutions in bulk semiconductors. Photoluminescence spectra indicate deep impurity levels of 0.5-0.9 eV above the top of the valence band for such systems as GaN:As, GaN:P, CdS:Te, and ZnS:Te. Previous calculations based on small supercells seemingly confirmed these experimental results. However, the current ab initio calculations based on thousand-atom supercells indicate that the impurity levels of the above systems are actually much shallower (0.05-0.20 eV), and these impurity levels should be compared with photoluminescence excitation spectra, not photoluminescence spectra. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Li, JB (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 25 TC 19 Z9 20 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 033102 DI 10.1103/PhysRevB.67.033102 PG 4 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800002 ER PT J AU Mun, ED Kwon, YS Jung, MH AF Mun, ED Kwon, YS Jung, MH TI Anderson lattice in CeNiSi2 intermediate valence compound SO PHYSICAL REVIEW B LA English DT Article ID HEAVY-FERMION COMPOUNDS; MAGNETIC-PROPERTIES; KONDO-LATTICE; SUSCEPTIBILITY; RESISTIVITY; COHERENCE; CAPACITY; MODEL AB We present experimental results of electrical resistivity, Hall coefficient, magnetic susceptibility, and specific heat for single crystals of the Ce-based intervalent compound CeNiSi2. The results show similar behaviors observed in Yb-based intervalent compounds and support a recent theory of the Anderson lattice, in which the Fermi-liquid coherence is gloval over the whole lattice. There is a low-temperature scale T(coh)similar to50 K for the onset of Fermi-liquid coherence, in addition to a high-temperature scale T-K*similar to150 K for the Kondo lattice condensation. Therefore we conclude that two energy scales are generic in intermediate valence compounds based on Ce where the orbital degeneracy is smaller and where the size of the 4f orbital is larger than those based on Yb. C1 Sungkyunkwan Univ, Phys Res Div BK21, Suwon 440746, South Korea. Sungkyunkwan Univ, Inst Basic Sci, Suwon 440746, South Korea. Seoul Natl Univ, Ctr Stongly Correlated Mat Res, Seoul 151742, South Korea. Los Alamos Natl Lab, MST NHMFL, Los Alamos, NM 87545 USA. RP Kwon, YS (reprint author), Sungkyunkwan Univ, Phys Res Div BK21, Suwon 440746, South Korea. EM yskwon@skku.ac.kr NR 15 TC 19 Z9 19 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 033103 DI 10.1103/PhysRevB.67.033103 PG 3 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800003 ER PT J AU Ronning, F Kim, C Shen, KM Armitage, NP Damascelli, A Lu, DH Feng, DL Shen, ZX Miller, LL Kim, YJ Chou, F Terasaki, I AF Ronning, F Kim, C Shen, KM Armitage, NP Damascelli, A Lu, DH Feng, DL Shen, ZX Miller, LL Kim, YJ Chou, F Terasaki, I TI Universality of the electronic structure from a half-filled CuO2 plane SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; SPIN-CHARGE SEPARATION; REMNANT FERMI-SURFACE; T-J MODEL; HUBBARD-MODEL; SUPERCONDUCTING STATE; DYNAMIC PROPERTIES; CU3O4 PLANE; HOLE; SR2CUO2CL2 AB We present angle-resolved photoemission spectroscopy data from insulating A(2)CuO(2)X(2) (A=Sr, Ca; X=Cl, Br), Sr2Cu3O4Cl2, and Bi2Sr2MCu2O8 (M=Er, Dy) single crystals, which illustrate that the low-energy electronic structure of the half-filled cuprates are independent of the apical atom. By performing a photon energy dependent study on Ca2CuO2Cl2, we are able to distinguish between features which are intrinsic and those which are a result of the photoemission matrix elements. We find that the dispersion is independent of photon energy, while an asymmetry in the electron occupation probability across the antiferromagnetic zone boundary is robust to variations in photon energy. Finally, we show that the d-wave-like dispersion which exists in the insulator along the antiferromagnetic zone boundary does not precisely fit the simple d-wave functional form near the nodal direction. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Waseda Univ, Dept Appl Phys, Tokyo 1698555, Japan. RP Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. RI Shen, Kyle/B-3693-2008; Kim, Young-June /G-7196-2011; damascelli, andrea/P-6329-2014; TERASAKI, Ichiro/I-7083-2014 OI Kim, Young-June /0000-0002-1172-8895; damascelli, andrea/0000-0001-9895-2226; TERASAKI, Ichiro/0000-0002-6073-2639 NR 55 TC 18 Z9 18 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035113 DI 10.1103/PhysRevB.67.035113 PG 16 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800041 ER PT J AU Seager, CH AF Seager, CH TI Comment on "Infrared spectroscopy of Mg-H local vibrational mode in GaN with polarized light" SO PHYSICAL REVIEW B LA English DT Editorial Material ID HYDROGEN; COMPLEXES AB Clerjaud [Phys. Rev. B 61, 8238 (2000)] analyzed infrared spectroscopic data obtained on GaN containing Mg-H complexes and claimed that it was consistent with a defect dipole aligned at 130degrees+/-5degrees from the c axis. This angle differs from that indicated for the lowest energy defect configuration in several density functional theory calculations. We suggest that their data analysis of the optical spectra did not take into account the internal reflections at the GaN/Al2O3 substrate interface. A correct theory of this situation is presented here; this illustrates that the interpretation of the ratio of Mg-H absorptance peak heights for two different polarizations is strongly dependent on the exact thickness of the GaN absorbing layer and on the distribution of Mg-H centers. Since only rough estimates of this thickness and no details of the Mg distribution were given by Clerjaud, we suggest that further analysis of their data is required in order to establish limits on the Mg-H dipole orientation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Seager, CH (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 037201 DI 10.1103/PhysRevB.67.037201 PG 2 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800123 ER PT J AU Shvets, G AF Shvets, G TI Photonic approach to making a material with a negative index of refraction SO PHYSICAL REVIEW B LA English DT Article AB An approach to producing a composite material with negative refraction index is demonstrated. It is shown that a photonic structure consisting of two dielectric materials, with positive and negative dielectric permittivities, can support electromagnetic surface waves which exhibit the unusual electromagnetic property of left handedness (or negative refraction index). Depending on the dielectric materials, these surface waves localized at the dielectric interfaces can be either surface plasmons or phonons. The detailed geometry of the structure determines whether this composite left-handed material is isotropic or anisotropic. C1 IIT, Chicago, IL 60616 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60520 USA. RP Shvets, G (reprint author), IIT, Chicago, IL 60616 USA. NR 15 TC 113 Z9 116 U1 2 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035109 DI 10.1103/PhysRevB.67.035109 PG 8 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800037 ER PT J AU Wu, J Walukiewicz, W Yu, KM Ager, JW Haller, EE Miotkowski, I Ramdas, AK Su, CH Sou, IK Perera, RCC Denlinger, JD AF Wu, J Walukiewicz, W Yu, KM Ager, JW Haller, EE Miotkowski, I Ramdas, AK Su, CH Sou, IK Perera, RCC Denlinger, JD TI Origin of the large band-gap bowing in highly mismatched semiconductor alloys SO PHYSICAL REVIEW B LA English DT Article ID NITROGEN-INDUCED INCREASE; ELECTRONIC-STRUCTURE; ZNSE; ZNTE AB Photomodulated reflection, optical absorption, and photoluminescence spectroscopies have been used to measure the composition dependence of interband optical transitions in ZnSe1-xTex and ZnS1-xTex alloys. The results reveal entirely different origins of the large band-gap bowing for small and large Te content. On the Te-rich side, the reduction of the band gap is well explained by the band anticrossing interaction between the Se or S localized states and the ZnTe conduction-band states. On the Se- or S-rich side, an interaction between the localized Te states and the degenerate Gamma valence bands of ZnSe or ZnS is responsible for the band-gap reduction and the rapid increase of the spin-orbit splitting with increasing Te concentration. Results of the soft-x-ray emission experiment provide direct proof of the valence-band anticrossing interaction. The band-gap bowing in the entire composition range is accounted for by a linear interpolation between the conduction-band anticrossing and valence-band anticrossing models. C1 Univ Calif Berkeley, Appl Sci & Technol Grad Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. NASA, George C Marshall Space Flight Ctr, Sci Directorate SD46, Huntsville, AL 35812 USA. Hong Kong Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong, Peoples R China. Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Wu, J (reprint author), Univ Calif Berkeley, Appl Sci & Technol Grad Grp, Berkeley, CA 94720 USA. RI Wu, Junqiao/G-7840-2011; Yu, Kin Man/J-1399-2012 OI Wu, Junqiao/0000-0002-1498-0148; Yu, Kin Man/0000-0003-1350-9642 NR 21 TC 39 Z9 39 U1 2 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 2003 VL 67 IS 3 AR 035207 DI 10.1103/PhysRevB.67.035207 PG 5 WC Physics, Condensed Matter SC Physics GA 644WR UT WOS:000180943800058 ER PT J AU Anderson, PR Molina-Paris, C Mottola, E AF Anderson, PR Molina-Paris, C Mottola, E TI Linear response, validity of semiclassical gravity, and the stability of flat space SO PHYSICAL REVIEW D LA English DT Article ID EINSTEIN-LANGEVIN EQUATION; VACUUM ENERGY DENSITY; DE-SITTER SPACE; QUANTUM-GRAVITY; BACK-REACTION; BLACK-HOLE; COSMOLOGICAL PERTURBATIONS; NONEQUILIBRIUM DYNAMICS; LAMBDA-PHI(4) THEORY; THERMAL-EQUILIBRIUM AB A quantitative test for the validity of the semiclassical approximation in gravity is given. The criterion proposed is that solutions to the semiclassical Einstein equations should be stable to linearized perturbations, in the sense that no gauge invariant perturbation should become unbounded in time. A self-consistent linear response analysis of these perturbations, based upon an invariant effective action principle, necessarily involves metric fluctuations about the mean semiclassical geometry, and brings in the two-point correlation function of the quantum energy-momentum tensor in a natural way. This linear response equation contains no state dependent divergences and requires no new renormalization counterterms beyond those required in the leading order semiclassical approximation. The general linear response criterion is applied to the specific example of a scalar field with arbitrary mass and curvature coupling in the vacuum state of Minkowski spacetime. The spectral representation of the vacuum polarization function is computed in n dimensional Minkowski spacetime, and used to show that the flat space solution to the semiclassical Einstein equations for n = 4 is stable to all perturbations on distance scales much larger than the Planck length. C1 Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Warwick, Inst Math, Coventry CV4 7AL, W Midlands, England. RP Anderson, PR (reprint author), Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA. NR 78 TC 30 Z9 30 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 2003 VL 67 IS 2 AR 024026 DI 10.1103/PhysRevD.67.024026 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 646BV UT WOS:000181015700050 ER PT J AU Csaki, C Erlich, J Terning, J AF Csaki, C Erlich, J Terning, J TI Seiberg-Witten description of the deconstructed 6D (0,2) theory SO PHYSICAL REVIEW D LA English DT Article ID SUPERSYMMETRIC GAUGE-THEORIES; PRODUCT GROUP THEORIES; SYMMETRY-BREAKING; DUALITY; DIMENSIONS; MONOPOLES; BRANES; VACUA; QCD AB It has recently been suggested that, in the large N limit, a particular four dimensional gauge theory is indistinguishable from six dimensional conformal field theory with (0,2) supersymmetry compactified on a torus. We give further evidence for this correspondence by studying the Seiberg-Witten curve for the "deconstructed" theory and demonstrating that along the reduced Coulomb branch of moduli space (at the intersection of the Higgs and Coulomb branches) it describes the low energy physics on a stack of M5-branes on a torus, which is the (0,2) theory on a torus as claimed. The M-theory construction helps to clarify the enhancement of supersymmetry in the deconstructed theory at low energies, and demonstrates its stability to radiative and instanton corrections. We demonstrate the role of the theta vacuum in the deconstructed theory. We point out that, by varying the theta parameters and gauge couplings in the deconstructed theory, the complex structure of the torus can be chosen arbitrarily, and the torus is not metrically S(1)xS(1) in general. C1 Cornell Univ, Newman Lab Elementary Particle Phys, Ithaca, NY 14853 USA. Los Alamos Natl Lab, Theory Div T8, Los Alamos, NM 87545 USA. RP Csaki, C (reprint author), Cornell Univ, Newman Lab Elementary Particle Phys, Ithaca, NY 14853 USA. NR 43 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 2003 VL 67 IS 2 AR 025019 DI 10.1103/PhysRevD.67.025019 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 646BV UT WOS:000181015700081 ER PT J AU Meurice, Y AF Meurice, Y TI Complex singularities of the critical potential in the large-N limit SO PHYSICAL REVIEW D LA English DT Article ID DYSONS HIERARCHICAL MODEL; RENORMALIZATION-GROUP TRANSFORMATIONS; HIGH-TEMPERATURE EXPANSION; SYMMETRY BREAKING; FIXED-POINT; EXPONENTS; BEHAVIOR AB We show with two numerical examples that the conventional expansion in powers of the field for the critical potential of 3-dimensional O(N) models in the large-N limit does not converge for values of phi(2) larger than some critical value. This can be explained by the existence of conjugated branch points in the complex phi(2) plane. Pade approximants [L + 3/L] for the critical potential apparently converge at large phi(2). This allows high-precision calculation of the fixed point in a more suitable set of coordinates. We argue that the singularities are generic and not an artifact of the large-N limit. We show that ignoring these singularities may lead to inaccurate approximations. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Meurice, Y (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 32 TC 2 Z9 2 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 2003 VL 67 IS 2 AR 025006 DI 10.1103/PhysRevD.67.025006 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 646BV UT WOS:000181015700068 ER PT J AU Makarova, OV Mancini, DC Moldovan, N Divan, R Tang, CM Ryding, DG Lee, RH AF Makarova, OV Mancini, DC Moldovan, N Divan, R Tang, CM Ryding, DG Lee, RH TI Microfabrication of freestanding metal structures using graphite substrate SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article; Proceedings Paper CT 15th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2002) CY JAN 20-24, 2002 CL LAS VEGAS, NEVADA SP IEEE, Robot & Automat Soc DE graphite substrate; LIGA; MEMS; microstructure release; high-aspect-ratio; antiscatter grid ID X-RAY-LITHOGRAPHY; DEEP; ADHESION; MASKS AB A novel method of fabricating freestanding electroformed metal structures using a rigid porous graphite substrate is reported. Polymethylmethacrylate's adhesion to graphite is much stronger compared with metal-coated silicon or graphite, because of graphite's high porosity and microroughness. Another advantage of graphite is its easy sacrificial removal by abrasion. Results are presented on the fabrication of high-aspect-ratio freestanding copper grids used as collimators in mammography and medical imaging. The method can be used in the production of micromolds for hot embossing and injection mold fabrication of microelectromechanical systems (MEMSs) and for fabrication of arrays of microparts on pick-and-place carriers for assembly into MEMS. Published by Elsevier Science B.V. C1 Creatv Micro Tech Inc, Potomac, MD 20854 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Makarova, OV (reprint author), Creatv Micro Tech Inc, Potomac, MD 20854 USA. NR 11 TC 15 Z9 15 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD JAN 15 PY 2003 VL 103 IS 1-2 BP 182 EP 186 AR PII S0924-4247(02)00333-3 DI 10.1016/S0924-4247(02)00333-3 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 635UQ UT WOS:000180418200025 ER PT J AU Baselt, DR Fruhberger, B Klaassen, E Cemalovic, S Britton, CL Patel, SV Mlsna, TE McCorkle, D Warmack, B AF Baselt, DR Fruhberger, B Klaassen, E Cemalovic, S Britton, CL Patel, SV Mlsna, TE McCorkle, D Warmack, B TI Design and performance of a microcantilever-based hydrogen sensor SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE hydrogen; cantilever; palladium; MEMS; gas sensor ID SENSITIVE MOS-STRUCTURES; CHEMICAL SENSOR; CANTILEVER; READOUT AB This paper describes the design of, and the effects of basic environmental parameters on, a microelectromechanical (MEMS) hydrogen sensor. The sensor contains an array of 10 micromachined cantilever beams. Each cantilever is 500 mum wide x 267 mum long x 2 mum thick and has a capacitance readout capable of measuring cantilever deflection to within 1 nm. A 20-nm-thick coating of 90% palladium-10% nickel bends some of the cantilevers in the presence of hydrogen. The palladium-nickel coatings are deposited in ultra-high-vacuum (UHV) to ensure freedom from a "relaxation" artifact apparently caused by oxidation of the coatings. The sensor consumes 84 mW of power in continuous operation, and can detect hydrogen concentrations between 0.1 and 100% with a roughly linear response between 10 and 90% hydrogen. The response magnitude decreases with increasing temperature, humidity, and oxygen concentration, and the response time decreases with increasing temperature and hydrogen concentration. The 0-90% response time of an unheated cantilever to 1% hydrogen in air is about 90 s at 25 degreesC and 0% humidity. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Graviton Inc, Chem Sensors Div, La Jolla, CA 92037 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Intel Corp, Santa Clara, CA 95052 USA. RP Baselt, DR (reprint author), Graviton Inc, Chem Sensors Div, 11025 N Torrey Pines Rd,Suite 200, La Jolla, CA 92037 USA. RI Patel, Sanjay/D-2903-2014 OI Patel, Sanjay/0000-0001-9540-9957 NR 24 TC 127 Z9 129 U1 4 U2 33 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 15 PY 2003 VL 88 IS 2 BP 120 EP 131 AR PII S0925-4005(02)00315-5 DI 10.1016/S0925-4005(02)00315-5 PG 12 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 633YU UT WOS:000180313200002 ER PT J AU Eikerling, M Paddison, SJ Pratt, LR Zawodzinski, TA AF Eikerling, M Paddison, SJ Pratt, LR Zawodzinski, TA TI Defect structure for proton transport in a triflic acid monohydrate solid SO CHEMICAL PHYSICS LETTERS LA English DT Article ID INITIO MOLECULAR-DYNAMICS; FUEL-CELLS; CONDUCTING MEMBRANES; TEMPERATURE; TRANSITION; WATER; PSEUDOPOTENTIALS; ELECTROLYTES; SIMULATION; MECHANISM AB The mechanism of proton transport in a trifluoromethane sulfonic acid monohydrate solid is investigated using ab initio molecular dynamics. This system provides a model for proton transfer in minimally hydrated sulfonic acid based polymer electrolyte membranes, materials of technological importance in fuel cells. As a mechanism of proton transport, these simulations identify a defect involving the formation of an H5O2+ ion and the re-organization of neighboring sulfonate groups, which share a proton between the oxygen atoms of the anionic sites. The energy of formation of this defect (0.3 eV) agrees with the experimentally determined activation energy for proton transport in minimally hydrated Nafion(R) of 0.36 eV. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. Case Western Reserve Univ, Dept Chem Engn, Cleveland, OH 44106 USA. Los Alamos Natl Lab, Div Sci Mat, Los Alamos, NM 87545 USA. Tech Univ Munich, Dept Phys, D-85748 Munich, Germany. Motorola Inc, Comp Nanosci Grp, Los Alamos, NM 87544 USA. RP Paddison, SJ (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RI Pratt, Lawrence/H-7955-2012; Paddison, Stephen/B-2935-2014 OI Pratt, Lawrence/0000-0003-2351-7451; NR 34 TC 79 Z9 80 U1 1 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 14 PY 2003 VL 368 IS 1-2 BP 108 EP 114 AR PII S0009-2614(02)01733-5 DI 10.1016/S0009-2614(02)01733-5 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634BJ UT WOS:000180319900017 ER PT J AU Wilcox, L Burnside, G Kiranga, B Shekhawat, R Mazumder, MK Hawk, RM Lindquist, DA Burton, SD AF Wilcox, L Burnside, G Kiranga, B Shekhawat, R Mazumder, MK Hawk, RM Lindquist, DA Burton, SD TI Porous alumina prepared from diethylaluminum amide, acetone, and water SO CHEMISTRY OF MATERIALS LA English DT Article ID GEL AB A previously described synthetic method was modified to improve the porosity of the alumina product. The compound (Et2AlNH2)(3) was prepared from ammonia and triethyl-aluminum (Et3Al) in toluene solvent. Addition of acetone to form a solution of ethylaluminoxane (EtAlO) and acetonine (2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydropyrimidine) was followed by addition of two equivalents of water to give an alumina precursor. Alumina precursors also were prepared by the direct hydrolysis of (Et2AlNH2)(3). Powder X-ray diffraction, Al-27 MAS NMR, and N-2 adsorption/desorption isotherms were used to analyze the aluminas after calcination of the precipitates. The aluminas exhibited high pore volume and surface area, and they were amorphous after calcination at 500 degreesC. One alumina showed a significant fraction of pentacoordinate aluminum after heating to 300 degreesC in air or 500 degreesC in steam atmosphere. The products crystallized as alpha-Al2O3 at the low temperature of 1000 degreesC, which reduces their applicability for catalysts. Synthesis variables and their effects on alumina properties are discussed. C1 Univ Arkansas, Dept Chem, Little Rock, AR 72204 USA. Univ Arkansas, Dept Appl Sci, Little Rock, AR 72204 USA. Pacific NW Natl Lab, William R Wiley Environm & Mol Sci Labs, Richland, WA 99352 USA. RP Lindquist, DA (reprint author), Univ Arkansas, Dept Chem, Little Rock, AR 72204 USA. EM dalindquist@ualr.edu NR 20 TC 19 Z9 21 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN 14 PY 2003 VL 15 IS 1 BP 51 EP 56 DI 10.1021/cm020836w PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 634XP UT WOS:000180368000011 ER PT J AU Ye, XR Wai, CM Zhang, DQ Kranov, Y McIlroy, DN Lin, YH Engelhard, M AF Ye, XR Wai, CM Zhang, DQ Kranov, Y McIlroy, DN Lin, YH Engelhard, M TI Immersion deposition of metal films on silicon and germanium substrates in supercritical carbon dioxide SO CHEMISTRY OF MATERIALS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; ELECTROLESS DEPOSITION; REACTIVE DEPOSITION; COPPER DEPOSITION; FLUID DEPOSITION; PALLADIUM FILMS; THIN-FILMS; X-RAY; SURFACE; GROWTH AB A low-temperature CO2-based technology, supercritical fluid immersion deposition (SFID), has been developed for producing Pd, Cu, Ag, or other metal films on Si-based substrates in supercritical CO2 solutions. The reaction is most likely initiated by oxidation of elemental silicon to SiF4 or H(2)SiFs with HF, causing the reduction of a metal chelate precursor to the metallic form on silicon surface in CO2]. Using this method, only the substrate surfaces exposed to CO2 solutions are coated with metals, and the metal films (Pd, Cu, and Ag) exhibit good coverage, smooth and dense texture, and high purity. Preliminary experiment indicates that palladium films deposited on silicon by SFID can be converted to palladium silicide by annealing treatment. Metal films can also be deposited onto germanium substrates using SFID. The gaslike properties and high pressure of the supercritical fluids, combined with the low reaction temperature, make this SFID method potentially useful for fabricating thin films of metal or metal silicide in small features, which is difficult to accomplish by conventional metal deposition methods. C1 Univ Idaho, Dept Chem, Moscow, ID 83844 USA. Univ Idaho, Dept Phys, 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, Moscow, ID 83844 USA. EM cwai@uidaho.edu 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 83 TC 40 Z9 41 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN 14 PY 2003 VL 15 IS 1 BP 83 EP 91 DI 10.1021/cm011534h PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 634XP UT WOS:000180368000017 ER PT J AU Boyle, TJ Coker, EN Zechmann, CA Voigt, JA Rodriguez, MA Kemp, RA AF Boyle, TJ Coker, EN Zechmann, CA Voigt, JA Rodriguez, MA Kemp, RA TI Precipitation of spherical magnesium(II) cresolate particles SO CHEMISTRY OF MATERIALS LA English DT Article ID RAY CRYSTAL-STRUCTURES; PRECURSORS; ALKOXIDES AB Magnesium bis-o-cresol (or o-methylphenoxide), [Mg(oMP)(2)](n) (1), was prepared through a variety of synthetic routes that involved the stoichiometric reaction of o-methylphenol (H-oMP), with Mg(Bu)(2), Mg{N(Si(CH3)(3))(2)}(2)(THF)(2), or the bulk metal (Mg-0). In all cases the low-temperature product was found to be soluble, while precipitation occurred at higher temperatures. The precipitate could only be redissolved by the addition of pyridine or a similarly strongly coordinating Lewis base. The pyridine and NH3 adducts of 1 were isolated as monomeric species, whereas the THF adduct proved to be the dimeric [Mg(mu-oMP)(oMP)-(THF)(2)](2), 2. For a limited set of conditions, sufficient control over the precipitation kinetics of the reaction between Mg(Bu)(2) and H-oMP was realized to yield spherical morphologies. The window of spherulitic growth was small and could only be partially controlled by varying reaction conditions during the precipitation. Use of seed particles to control nucleation events during precipitation was found to lead to increased monodispersity of spherical [Mg(oMP)(2)](n) precipitate powders. C1 Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. Union Carbide Corp, Houston, TX USA. RP Boyle, TJ (reprint author), Sandia Natl Labs, Adv Mat Lab, 1001 Univ Blvd SE, Albuquerque, NM 87106 USA. NR 11 TC 5 Z9 5 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN 14 PY 2003 VL 15 IS 1 BP 309 EP 319 DI 10.1021/cm020802o PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 634XP UT WOS:000180368000047 ER PT J AU Seong, MJ Micic, OI Nozik, AJ Mascarenhas, A Cheong, HM AF Seong, MJ Micic, OI Nozik, AJ Mascarenhas, A Cheong, HM TI Size-dependent raman study of InP quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article ID RESONANCE RAMAN; SEMICONDUCTOR MICROCRYSTALLITES; CDSE; SPECTROSCOPY; NANOCRYSTALS; SUPERLATTICES; SCATTERING; MOLECULES; CLUSTERS AB Raman spectrum of a quantum dot (QD) is characterized by transverse (TO) and longitudinal (LO) optical modes as well as surface optical modes, occurring between the TO and LO modes. We have studied in detail the size-dependence of the Raman spectrum of InP QD of diameter larger than 35 Angstrom. The LO phonon frequency decreases while the TO phonon frequency increases with decreasing QD size. The linewidth of the LO phonon broadens and the broadening becomes increasingly asymmetrical towards the low frequency side as the QD size decreases. By analyzing the Raman intensity ratio of the LO phonon to its overtone, we find that the electron-phonon coupling decreases with decreasing QD size. (C) 2003 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Sogang Univ, Dept Phys, Seoul 121742, South Korea. RP Seong, MJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Cheong, Hyeonsik/D-7424-2012; Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 OI Cheong, Hyeonsik/0000-0002-2347-4044; NR 22 TC 58 Z9 59 U1 1 U2 20 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 13 PY 2003 VL 82 IS 2 BP 185 EP 187 DI 10.1063/1.1535272 PG 3 WC Physics, Applied SC Physics GA 634AG UT WOS:000180317400011 ER PT J AU Kalyanaraman, R Venezia, VC Pelaz, L Haynes, TE Gossmann, HJL Rafferty, CS AF Kalyanaraman, R Venezia, VC Pelaz, L Haynes, TE Gossmann, HJL Rafferty, CS TI Enhanced low temperature electrical activation of B in Si SO APPLIED PHYSICS LETTERS LA English DT Article ID ENERGY ION-IMPLANTATION; BORON-DIFFUSION; SILICON; REDUCTION; DAMAGE; CLUSTERS; DEFECTS AB The electrical activation of B in n-type epitaxial-Si(100) has been enhanced in the temperature range of 400-800 degreesC. This enhanced activation was measured for 40 keV, 2x10(14) cm(-2) dose of B implanted into a vacancy-rich Si region. The vacancy-rich region consists of excess vacancies (V-ex) generated by a 2 MeV Si implant in the dose range of 3x10(15)-10x10(15) cm(-2). The B activation in vacancy-rich Si is found to be a factor of similar to2.4 larger with up to similar to80% of the B activated as compared to similar B implant and activation anneals carried out in the bulk Si. The dependence of B activation on V-ex concentration shows that the active B concentration increases with the V-ex concentration. From this dependence it was estimated that at least three vacancies are required to activate an additional B atom. This process is distinctly different from the low temperature activation that occurs during solid-phase epitaxial recrystallization of B-doped amorphous Si as no amorphous Si is produced during any step. This low temperature processing will be advantageous in situations where the epitaxial recrystallization of a doped amorphous Si layer is not possible, for instance in the fabrication of fully depleted Si-on-insulator devices. (C) 2003 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Washington Univ, St Louis, MO 63130 USA. Agere Syst, Murray Hill, NJ 07974 USA. IMEC, Phillips Royal Elect, Louvain, Belgium. Univ Valladolid, E-47011 Valladolid, Spain. RP Kalyanaraman, R (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Pelaz, Lourdes/M-1766-2014; Haynes, Tony/P-8932-2015; OI Haynes, Tony/0000-0003-2871-4745; kalyanaraman, ramki/0000-0002-5340-029X NR 25 TC 14 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 13 PY 2003 VL 82 IS 2 BP 215 EP 217 DI 10.1063/1.1535270 PG 3 WC Physics, Applied SC Physics GA 634AG UT WOS:000180317400021 ER PT J AU Norton, DP Pearton, SJ Hebard, AF Theodoropoulou, N Boatner, LA Wilson, RG AF Norton, DP Pearton, SJ Hebard, AF Theodoropoulou, N Boatner, LA Wilson, RG TI Ferromagnetism in Mn-implanted ZnO : Sn single crystals SO APPLIED PHYSICS LETTERS LA English DT Article ID ROOM-TEMPERATURE FERROMAGNETISM; DILUTED MAGNETIC SEMICONDUCTOR AB We have investigated the magnetic properties of Mn-implanted n-type ZnO single crystals that are codoped with Sn. Theory predicts that room-temperature carrier-mediated ferromagnetism should be possible in manganese-doped p-type ZnO, although Mn-doped n-type ZnO should not be ferromagnetic. While previous efforts report only low-temperature ferromagnetism in Mn-doped ZnO that is n type via shallow donors, we find evidence for ferromagnetism with a Curie temperature of similar to250 K in ZnO that is codoped with Mn and Sn. As a 4+ valence cation, Sn should behave as a doubly ionized donor, thus introducing states deep in the gap. Hysteresis is clearly observed in magnetization versus field curves. Differences in zero-field-cooled and field-cooled magnetization persists up to similar to250 K for Sn-doped ZnO crystals implanted with 3 at. % Mn. Increasing the Mn concentration to 5 at. % significantly reduces the magnetic hysteresis. This latter observation is inconsistent with the origin for ferromagnetism being due to segregated secondary phases, and strongly suggests that a near-room-temperature dilute magnetic semiconducting oxide has been realized. Based on these results, ZnO doped with Mn and Sn may prove promising as a ferromagnetic semiconductor for spintronics. (C) 2003 American Institute of Physics. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Stevenson Ranch, San Jose, CA 95131 USA. RP Norton, DP (reprint author), Univ Florida, Dept Mat Sci & Engn, 106 Rhines Hall,POB 116400, Gainesville, FL 32611 USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 27 TC 369 Z9 386 U1 4 U2 28 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 13 PY 2003 VL 82 IS 2 BP 239 EP 241 DI 10.1063/1.1537457 PG 3 WC Physics, Applied SC Physics GA 634AG UT WOS:000180317400029 ER PT J AU Curtis, CJ Miedaner, A Ciancanelli, R Ellis, WW Noll, BC DuBois, MR DuBois, DL AF Curtis, CJ Miedaner, A Ciancanelli, R Ellis, WW Noll, BC DuBois, MR DuBois, DL TI [Ni(Et2PCH2NMeCH2PEt2)(2)](2+) as a functional model for hydrogenases SO INORGANIC CHEMISTRY LA English DT Article ID FE-ONLY HYDROGENASE; NICKEL-IRON HYDROGENASE; ACTIVE-SITE; CRYSTAL-STRUCTURE; NIFE HYDROGENASE; ANGSTROM RESOLUTION; BRIDGING LIGAND; PROTON-TRANSFER; COMPLEXES; HYDRIDE AB The reaction of Et2PCH2N(Me)CH2PEt2 (PNP) with [Ni(CH3CN)(6)](BF4)(2) results in the formation of [Ni(PNP)(2)](BF4)(2), which possesses both hydride- and proton-acceptor sites. This complex is an electrocatalyst for the oxidation of hydrogen to protons, and stoichiometric reaction with hydrogen forms [HNi(PNP)(PNHP)](BF4)(2), in which a hydride ligand is bound to Ni and a proton is bound to a pendant N atom of one PNP ligand. The free energy associated with this reaction has been calculated to be -5 kcal/mol using a thermodynamic cycle. The hydride ligand and the NH proton undergo rapid intramolecular exchange with each other and intermolecular exchange with protons in solution. [HNi(PNP)(PNHP)](BF4)(2) undergoes reversible deprotonation to form [HNi(PNP)(2)](BF4) in acetonitrile solutions (pK(a) = 10.6). A convenient synthetic route to the PF6- salt of this hydride involves the reaction of PNP with Ni(COD)(2) to form Ni(PNP)(2), followed by protonation with NH4PF6. A pK(a) of value of 22.2 was measured for this hydride. This value, together with the half-wave potentials of [Ni(PNP)(2)](BF4)(2), was used to calculate homolytic and heterolytic Ni-H bond dissociation free energies of 55 and 66 kcal/mol, respectively, for [HNi(PNP)(2)](PF6). Oxidation of [HNi(PNP)(2)](PF6) has been studied by cyclic voltammetry, and the results are consistent with a rapid migration of the proton from the Ni atom of the resulting [HNi(PNP)(2)](2+) cation to the N atom to form [Ni(PNP)(PNHP)](2+). Estimates of the pK(a) values of the NiH and NH protons of these two isomers indicate that proton migration from Ni to N should be favorable by 1-2 pK(a) units. Cyclic voltammetry and proton exchange studies of [HNi(depp)(2)]-(PF6) (where depp is Et2PCH2CH2CH2PEt2) are also presented as control experiments that support the important role of the bridging N atom of the PNP ligand in the proton exchange reactions observed for the various Ni complexes containing the PNP ligand. Similarly, structural studies of [Ni(PNBuP)(2)](BF4)(2) and [Ni(PNP)(dmpm)](BF4)(2) (where PNBuP is Et2PCH2N(Bu)CH2PEt2 and dmpm is Me2PCH2Me2) illustrate the importance of tetrahedral distortions about Ni in determining the hydride acceptor ability of Ni(II) complexes. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP DuBois, DL (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 40 TC 148 Z9 148 U1 5 U2 31 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 13 PY 2003 VL 42 IS 1 BP 216 EP 227 DI 10.1021/ic020610v PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 634JT UT WOS:000180336800029 PM 12513098 ER PT J AU Shanahan, KL Holder, JS AF Shanahan, KL Holder, JS TI Tritium aging effects in a Pd0.94Rh0.05Co0.01 foil SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE tritium aging; hydrogen storage ID DECAY AB Tritium aging characteristics of a melt-spun Pd0.94Rh0.05Co0.01 foil have been determined. Typical behavior is observed in that plateau pressure depression and heel growth is noted. Some healing of the decay damage resulted from the first absorption-desorption cycle, but the material is thereafter stable to cycling. Hysteresis is significantly reduced by aging. (C) 2002 Westinghouse Savannah River Company. Published by Elsevier Science B.V. All rights reserved. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Shanahan, KL (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Bldg 232-H, Aiken, SC 29808 USA. NR 6 TC 5 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JAN 13 PY 2003 VL 348 IS 1-2 BP 72 EP 75 AR PII S0925-8388(02)00777-6 DI 10.1016/S0925-8388(02)00777-6 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 631DZ UT WOS:000180153600012 ER PT J AU Heinz, A Schmidt, KH Junghans, AR Armbruster, P Benlliure, J Bockstiegel, C Clerc, HG Grewe, A de Jong, M Muller, J Pfutzner, M Steinhauser, S Voss, B AF Heinz, A Schmidt, KH Junghans, AR Armbruster, P Benlliure, J Bockstiegel, C Clerc, HG Grewe, A de Jong, M Muller, J Pfutzner, M Steinhauser, S Voss, B TI Electromagnetic-induced fission of U-238 projectile fragments, a test case for the production of spherical super-heavy nuclei SO NUCLEAR PHYSICS A LA English DT Article DE secondary beams produced by projectile fragmentation; nuclear fission; electromagnetic excitation; measured fission cross sections; deduced fission probabilities; shell effects; perspectives for the production of spherical super-heavy nuclei ID ANGULAR-MOMENTUM; HEAVIEST NUCLEI; CROSS-SECTIONS; LEVEL DENSITY; MODEL; COLLISIONS; BARRIERS; DECAY; BEAMS; IONS AB Isotopic series of 58 neutron-deficient secondary projectiles (At-205,At-206, Rn205-209, 208-212,217,218FR, (211-223)RA, Ac215-226, Th221-229, Pa226-231, U231-234) were produced by projectile fragmentation using a 1 A GeV U-238 beam. Cross sections of fission induced by nuclear and electromagnetic interactions in a secondary lead target were measured. They were found to vary smoothly as a function of proton and neutron number of the fissioning system, also for nuclei with large ground-state shell effects near the 126-neutron shell. No stabilization against fission was observed for these nuclei at low excitation energies. Consequences for the expectations on the production cross sections of super-heavy nuclei are discussed. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Gesell Schwerionenforsch mbH, D-64291 Darmstadt, Germany. Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany. Univ Santiago de Compostela, Fac Fis, Santiago De Compostela 15706, Spain. Warsaw Univ, Inst Fizyki Doswiadczalney, PL-00381 Warsaw, Poland. RP Heinz, A (reprint author), Argonne Natl Lab, Phys Div, Bd 203,9700 S Cass Ave, Argonne, IL 60439 USA. RI Heinz, Andreas/E-3191-2014; Junghans, Arnd/D-4596-2012; Benlliure, Jose/K-8407-2014 OI Benlliure, Jose/0000-0002-5114-1298 NR 38 TC 28 Z9 28 U1 1 U2 4 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 13 PY 2003 VL 713 IS 1-2 BP 3 EP 23 AR PII S0375-9474(02)01296-4 DI 10.1016/S0375-9474(02)01296-4 PG 21 WC Physics, Nuclear SC Physics GA 620FR UT WOS:000179523800001 ER PT J AU Omenetto, FG Efimov, A Taylor, AJ Knight, JC Wadsworth, WJ Russell, PSJ AF Omenetto, FG Efimov, A Taylor, AJ Knight, JC Wadsworth, WJ Russell, PSJ TI Polarization dependent harmonic generation in microstructured fibers SO OPTICS EXPRESS LA English DT Article ID OPTICAL FIBERS AB We report on the control of visible harmonic generation in microstructured fiber through the polarization state of the fundamental radiation. By coupling lambda=1.55 mum fermosecond pulses that have the same peak power into a short length (Z=20 cm) of high-Delta microstructured fiber, we observe the generation of distinct visible spectral components in the visible at the output of the fiber in dependence of the input pulse's polarization state. (C) 2003 Optical Society of America. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Bath, Dept Phys, Bath BA2 7AY, Avon, England. RP Omenetto, FG (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MST-10,MS K764, Los Alamos, NM 87545 USA. EM omenetto@lanl.gov RI Wadsworth, William/A-1317-2012; Knight, Jonathan/D-3879-2011; Russell, Philip/G-5132-2012; OI Knight, Jonathan/0000-0002-0802-8804; Russell, Philip/0000-0002-8972-2477; Efimov, Anatoly/0000-0002-5559-4147 NR 11 TC 37 Z9 40 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD JAN 13 PY 2003 VL 11 IS 1 BP 61 EP 67 DI 10.1364/OE.11.000061 PG 7 WC Optics SC Optics GA 634NE UT WOS:000180346300009 PM 19461706 ER PT J AU Hughes, DA Hansen, N Bammann, DJ AF Hughes, DA Hansen, N Bammann, DJ TI Geometrically necessary boundaries, incidental dislocation boundaries and geometrically necessary dislocations SO SCRIPTA MATERIALIA LA English DT Article ID DEFORMATION; MICROSTRUCTURE AB The concept of statistically stored and geometrically necessary dislocations is discussed in terms of observed deformation microstructures subdivided by incidental dislocation and geometrically necessary boundaries. This discussion is illustrated by examples of microstructures formed under conditions of homogeneous and nonhomogeneous deformation, respectively. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Ctr Mat & Engn Sci, Livermore, CA 94550 USA. Riso Natl Lab, Ctr Fundamental Res, Mat Res Dept, DK-4000 Roskilde, Denmark. RP Hughes, DA (reprint author), Sandia Natl Labs, Ctr Mat & Engn Sci, POB 969, Livermore, CA 94550 USA. NR 24 TC 117 Z9 120 U1 8 U2 53 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 13 PY 2003 VL 48 IS 2 BP 147 EP 153 AR PII S1359-6462(02)00358-5 DI 10.1016/S1359-6462(02)00358-5 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 626NZ UT WOS:000179880600007 ER PT J AU Rosales, I Schneibel, JH Heatherly, L Horton, JA Martinez, L Campillo, B AF Rosales, I Schneibel, JH Heatherly, L Horton, JA Martinez, L Campillo, B TI High temperature deformation of A15 Mo3Si single crystals SO SCRIPTA MATERIALIA LA English DT Article DE single crystal; intermetallic compounds; high temperature mechanical properties; yield phenomena ID MECHANICAL-PROPERTIES; MO-12SI-8.5B AT.PERCENT; BEHAVIOR; SILICIDES; PHASE AB Mo3Si single crystals were tested in compression at 1325 degreesC in vacuum. The <110> and <111> specimens exhibited pronounced yield points. Slip trace analysis showed the active slip planes to be {001} and {012}, respectively, with similar critical resolved shear stresses. The hard <100> orientation exhibited neither slip traces nor an anomalous yield point. (C) 2002 Acta Materialia Inc. Published. by Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Fac Quim, Cuernavaca 62191, Morelos, Mexico. RP Schneibel, JH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 22 TC 13 Z9 14 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 13 PY 2003 VL 48 IS 2 BP 185 EP 190 AR PII S1359-6462(02)00360-3 DI 10.1016/S1359-6462(02)00360-3 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 626NZ UT WOS:000179880600013 ER PT J AU McDonald, J Velissaris, C Viren, B Diwan, M Erwin, AR Naples, D Ping, H AF McDonald, J Velissaris, C Viren, B Diwan, M Erwin, AR Naples, D Ping, H TI Ionization chambers for monitoring in high-intensity charged particle beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE ionization chambers; radiation hard detectors AB Radiation-hard ionization chambers were tested using an intense electron beam from the accelerator test facility at the Brookhaven National Laboratory. The detectors were designed to be used as the basic element for monitoring muons in the Main Injector Neutrino beamline at the Fermi National Accelerator Laboratory. Measurements of linearity of response, voltage dependence, and the onset of ionization saturation as a function of gap voltage were performed. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP McDonald, J (reprint author), Univ Pittsburgh, Dept Phys & Astron, 100 Allen Hall,3941 OHara St, Pittsburgh, PA 15260 USA. NR 9 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 2003 VL 496 IS 2-3 BP 293 EP 304 AR PII S0168-9002(02)01768-0 DI 10.1016/S0168-9002(02)01768-0 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 636VP UT WOS:000180478200006 ER PT J AU Barrett, CL Mortveit, HS Reidys, CM AF Barrett, CL Mortveit, HS Reidys, CM TI ETS IV: Sequential dynamical systems: fixed points, invertibility and equivalence SO APPLIED MATHEMATICS AND COMPUTATION LA English DT Article DE sequential dynamical system; quasi-symmetric functions; fixed points; digraph isomorphism; topological conjugation ID RANDOM GRAPHS; SIMULATION; ELEMENTS AB Sequential dynamical systems (SDSs) are discrete dynamical systems that are obtained from the following data: (a) a finite (labeled) graph Y with vertex set {1,...,n} where each vertex has a binary state, (b) a vertex labeled sequence of functions (F-i,F-Y : F-2(n)--> F-2(n))(i) and (c) a permutation pi is an element of S-n. The function F-i,F-Y updates the binary state of vertex i as a function of the states of vertex i and its Y-neighbors and leaves the states of all other vertices fixed. The permutation pi represents a Y-vertex ordering according to which the functions Fi,y are applied. By composing the functions F-i,F-Y in the order given by pi we obtain the SDS [F-Y,pi] = Pi(i=1)(n) F-n(i),F-Y : F-2(n) --> F-2(n.) In this paper we will generalize a class of results on SDS that have been proven for symmetric Boolean (local) functions to quasi-symmetric local functions. Further, we completely classify invertible SDS and investigate fixed points of sequential and parallel cellular automata (CA). Finally, we show sharpness of a combinatorial upper bound for the number of non-equivalent SDS that can be obtained through rescheduling for a certain class of graphs. Published by Elsevier Science Inc. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Barrett, CL (reprint author), Los Alamos Natl Lab, TSA-2,MS M997,Mailstop TA-0,SM-1237, Los Alamos, NM 87545 USA. NR 9 TC 14 Z9 15 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 10 PY 2003 VL 134 IS 1 BP 153 EP 171 AR PII S0096-3003(01)00277-6 DI 10.1016/S0096-3003(01)00277-6 PG 19 WC Mathematics, Applied SC Mathematics GA 606BR UT WOS:000178713600012 ER PT J AU Wojdowski, PS Liedahl, DA Sako, M Kahn, SM Paerels, F AF Wojdowski, PS Liedahl, DA Sako, M Kahn, SM Paerels, F TI Resolving the effects of resonant X-ray line scattering in Centaurus X-3 with Chandra SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; pulsars : individual (Centaurus X-3); radiative transfer; scattering; X-rays : binaries ID ILLUMINATED STELLAR WINDS; VELA X-1; MASS-LOSS; IONIZATION; SPECTROSCOPY; EMISSION; SPECTRUM; BINARY; STARS; FLUORESCENCE AB The massive X-ray binary Cen X-3 was observed over approximately one-quarter of the system's 2.08 day orbit, beginning before eclipse and ending slightly after eclipse center with the Chandra X-Ray Observatory using its High Energy Transmission Grating Spectrometer. The spectra show K-shell emission lines from hydrogen- and helium-like ions of magnesium, silicon, sulfur, and iron as well as a Kalpha fluorescence emission feature from near-neutral iron. The helium-like n=2-->1 triplet of silicon is fully resolved, and the analogous triplet of iron is partially resolved. We measure fluxes, shifts, and widths of the observed emission lines. The helium-like triplet component flux ratios outside of eclipse are consistent with emission from recombination and subsequent cascades (recombination radiation) from a photoionized plasma with a temperature of similar to100 eV. In eclipse, however, the w (resonance) lines of silicon and iron are stronger than that expected for recombination radiation and are consistent with emission from a collisionally ionized plasma with a temperature of similar to1 keV. The triplet line flux ratios at both phases can be explained more naturally, however, as emission from a photoionized plasma if the effects of resonant line scattering, a process that has generally been neglected in X-ray spectroscopy, are included in addition to recombination radiation. We show that resonant line scattering in photoionized plasmas may increase the emissivity of n=2-->1 line emission in hydrogen- and helium-like ions by a factor as large as 4 relative to that of pure recombination, and so previous studies, in which resonant scattering has been neglected, may contain significant errors in the derived plasma parameters. The emissivity due to resonance scattering depends sensitively on the line optical depth, and in the case of winds in X-ray binaries, this allows constraints on the wind velocity even when Doppler shifts cannot be resolved. C1 Lawrence Livermore Natl Lab, Dept Phys & Adv Technol, Livermore, CA 94551 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. RP Wojdowski, PS (reprint author), MIT, Ctr Space Res, NE80-6003,77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 42 TC 31 Z9 31 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 2003 VL 582 IS 2 BP 959 EP 971 DI 10.1086/344821 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 633KP UT WOS:000180282700033 ER PT J AU Reuland, M van Breugel, W Rottgering, H de Vries, W De Breuck, C Stern, D AF Reuland, M van Breugel, W Rottgering, H de Vries, W De Breuck, C Stern, D TI An obscured radio galaxy at high redshift SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : high-redshift; radio continuum : galaxies; submillimeter ID INFRARED GALAXIES; STAR-FORMATION; TELESCOPE; EMISSION; QUASARS; CAMERA AB Perhaps as many as 10% of high-redshift radio galaxy (z>2) candidates that are selected using an ultrasteep radio spectrum criterion fail to show optical emission (continuum, lines) in deep Keck exposures. Their parent objects are only detected in the near-IR and are probably heavily obscured and/or at very high redshift. To search for signatures of dust and help constrain the nature and redshifts of these "no-z" radio galaxies, we have conducted a program of submillimeter and millimeter observations. Here we report the first results of a detailed study of one of these objects, WN J0305+3525. It appears associated with a small group of Ksimilar to21-22 objects and is strongly detected at both 850 mum and 1.25 mm. On the basis of its faint K-band magnitude, spectral energy distribution, and other evidence, we estimate that the radio galaxy is probably at a redshift zsimilar or equal to3+/-1. This would make WN J0305-3525 a radio-loud hyperluminous infrared galaxy (L(FIR)similar to10(13) L-circle dot) similar to, but more obscured than, other dusty radio galaxies in this redshift range. This, together with the absence of Lyalpha emission and compact (thetaless than or similar to1".9) radio structure, suggests that WN J0305+3525 is embedded in a very dense, dusty medium and is probably at an early stage of its formation. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Inst Astrophys Paris, F-75014 Paris, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Reuland, M (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, L-413,POB 808, Livermore, CA 94551 USA. OI De Breuck, Carlos/0000-0002-6637-3315 NR 38 TC 2 Z9 2 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 2003 VL 582 IS 2 BP L71 EP L74 DI 10.1086/367689 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 633KQ UT WOS:000180282800003 ER PT J AU Shimaoka, M Xiao, T Liu, JH Yang, YT Dong, YC Jun, CD McCormack, A Zhang, RG Joachimiak, A Takagi, J Wang, JH Springer, TA AF Shimaoka, M Xiao, T Liu, JH Yang, YT Dong, YC Jun, CD McCormack, A Zhang, RG Joachimiak, A Takagi, J Wang, JH Springer, TA TI Structures of the alpha L I domain and its complex with ICAM-1 reveal a shape-shifting pathway for integrin regulation SO CELL LA English DT Article ID INTERCELLULAR-ADHESION MOLECULE-1; FUNCTION-ASSOCIATED ANTIGEN-1; CRYSTAL-STRUCTURE; LIGAND-BINDING; A-DOMAIN; CONFORMATIONAL-CHANGES; MONOCLONAL-ANTIBODY; INSERTED DOMAIN; T-CELLS; LFA-1 AB The structure of the I domain of integrin alphaLbeta2 bound to the Ig superfamily ligand ICAM-1 reveals the open ligand binding conformation and the first example of an integrin-IgSF interface. The I domain Mg2+ directly coordinates Glu-34 of ICAM-1, and a dramatic swing of I domain residue Glu-241 enables a critical salt bridge. Liganded and unliganded structures for both high- and intermediate-affinity mutant I domains reveal that ligand binding can induce conformational change in the alphaL I domain and that allosteric signals can convert the closed conformation to intermediate or open conformations without ligand binding. Pulling down on the C-terminal alpha7 helix with introduced disulfide bonds ratchets the beta6-alpha7 loop into three different positions in the closed, intermediate, and open conformations, with a progressive increase in affinity. C1 Harvard Univ, Sch Med, Dana Farber Canc Inst, Boston, MA 02115 USA. Harvard Univ, Sch Med, Ctr Blood Res, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Pathol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Anesthesia, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Pediat, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Biol Chem, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Mol Pharmacol, Boston, MA 02115 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Wang, JH (reprint author), Harvard Univ, Sch Med, Dana Farber Canc Inst, 44 Binney St, Boston, MA 02115 USA. EM jwang@red.dfci.harvard.edu; springer@cbr.med.harvard.edu RI Xiao, Tsan/A-8590-2010; Xiao, Tsan/I-7616-2013 OI Xiao, Tsan/0000-0001-9688-475X FU NCI NIH HHS [CA31798, R01 CA031798, R37 CA031798]; NHLBI NIH HHS [HL48675, P01 HL048675] NR 58 TC 335 Z9 347 U1 0 U2 14 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD JAN 10 PY 2003 VL 112 IS 1 BP 99 EP 111 DI 10.1016/S0092-8674(02)01257-6 PG 13 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 649DK UT WOS:000181191500010 PM 12526797 ER PT J AU Yu, HG AF Yu, HG TI Accelerating the calculation of the rovibrational energies of tetraatomic molecules using a two-layer Lanczos algorithm (vol 365, pg 189, 2002) SO CHEMICAL PHYSICS LETTERS LA English DT Correction C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Yu, HG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Yu, Hua-Gen/N-7339-2015 NR 1 TC 8 Z9 8 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 10 PY 2003 VL 367 IS 5-6 BP 791 EP 791 AR PII S0009-2614(02)01813-4 DI 10.1016/S0009-2614(02)01813-4 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634UE UT WOS:000180359100043 ER PT J AU Halpern, MB Wagner, F AF Halpern, MB Wagner, F TI The general coset orbifold action SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article DE orbifold; conformal field theory; string theory; WZW; coset ID CONFORMAL FIELD-THEORIES; VIRASORO CONSTRUCTION; 2 DIMENSIONS; AFFINE-G; MODELS; CURRENTS; ALGEBRA AB Recently an action formulation, called the general WZW orbifold action, was given for each sector of every WZW orbifold. In this paper we gauge this action by general twisted gauge groups to find the action formulation of each sector of every coset orbifold. Connection with the known current-algebraic formulation of coset orbifolds is discussed as needed, and some large examples are worked out in further, detail. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Theoret Phys, Berkeley, CA 94720 USA. RP Halpern, MB (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 25 TC 16 Z9 16 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JAN 10 PY 2003 VL 18 IS 1 BP 19 EP 55 DI 10.1142/S0217751X03012229 PG 37 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 638AJ UT WOS:000180545800003 ER PT J AU Anderson, DH Sawaya, MR Cascio, D Ernst, W Modlin, R Krensky, A Eisenberg, D AF Anderson, DH Sawaya, MR Cascio, D Ernst, W Modlin, R Krensky, A Eisenberg, D TI Granulysin crystal structure and a structure-derived lytic mechanism SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE granulysin; saposin fold; antimicrobial protein; crystal structure; lytic mechanism ID CYTOLYTIC T-CELLS; NK-LYSIN; MYCOBACTERIUM-TUBERCULOSIS; PROTEIN CRYSTALLOGRAPHY; MACROMOLECULAR STRUCTURES; MEMBRANE INTERACTIONS; GLOBULAR-PROTEINS; SWISS-MODEL; APOPTOSIS; CAVITIES AB Our crystal structure of granulysin suggests a mechanism for lysis of bacterial membranes by granulysin, a 74-residue basic protein from human cytolytic T lymphocyte and natural killer cells. We determined the initial crystal structure of selenomethionyl granulysin by MAD phasing at 2Angstrom resolution. We present the structure model refined using native diffraction data to 0.96Angstrom resolution. The five-helical bundle of granulysin resembles other "saposin folds" (such as NK-lysin). Positive charges distribute in a ring around the granulysin molecule, and one face has net positive charge. Sulfate ions bind near the segment of the molecule identified as most membrane-lytic and of highest hydrophobic moment. The ion locations may indicate granulysin's orientation of initial approach towards the membrane. The crystal packing reveals one way to pack a sheet of granulysin molecules at the cell surface for a concerted lysis effort. The energy of binding granulysin charges to the bacterial membrane could drive the subsequent lytic processes. The loosely packed core facilitates a hinge or scissors motion towards exposure of hydro-phobic surface that we propose tunnels the granulysin into the fracturing target membrane. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Howard Hughes Med Inst, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, US DOE, Inst Genom & Prote, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, David Geffen Sch Med, Div Dermatol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, David Geffen Sch Med, Dept Microbiol Mol Genet & Immunol, Los Angeles, CA 90095 USA. Stanford Univ, Dept Paediat, Stanford, CA 94305 USA. RP Anderson, DH (reprint author), Howard Hughes Med Inst, 5-748 MacDonald Box 951662, Los Angeles, CA 90095 USA. RI Krensky, Alan/F-7956-2011; OI Modlin, Robert/0000-0003-4720-031X; Sawaya, Michael/0000-0003-0874-9043 FU NIAID NIH HHS [AI43348, AI07118]; NIAMS NIH HHS [AR40312] NR 56 TC 95 Z9 106 U1 1 U2 7 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JAN 10 PY 2003 VL 325 IS 2 BP 355 EP 365 DI 10.1016/S0022-2836(02)01234-2 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 637MB UT WOS:000180514700009 PM 12488100 ER PT J AU Demirel, MC Kuprat, AP George, DC Rollett, AD AF Demirel, MC Kuprat, AP George, DC Rollett, AD TI Bridging simulations and experiments in microstructure evolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID GRAIN-BOUNDARY; MOBILITY; GEOMETRY AB We demonstrate the importance of anisotropic interface properties in microstructure evolution by comparing computed evolved microstructures to final experimental microstructures of 5170 grains in 19 thin aluminum foil samples. This is the first time that a direct experimental validation of simulation has been performed at the level of individual grains. We observe that simulated microstructures using curvature-driven grain boundary motion and anisotropic interface properties agree well with experimentally evolved microstructures, whereas agreement is poor when isotropic properties are used. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Demirel, MC (reprint author), Los Alamos Natl Lab, Div Theoret, MST-8, Los Alamos, NM 87545 USA. RI Demirel, Melik/E-4495-2010; Rollett, Anthony/A-4096-2012; Demirel, Melik/E-3775-2016 OI Rollett, Anthony/0000-0003-4445-2191; NR 17 TC 28 Z9 28 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 10 PY 2003 VL 90 IS 1 AR 016106 DI 10.1103/PhysRevLett.90.016106 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300039 PM 12570632 ER PT J AU Gilson, EP Fajans, J AF Gilson, EP Fajans, J TI Quadrupole-induced resonant-particle transport in a pure electron plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID ASYMMETRY-INDUCED TRANSPORT AB Small transverse magnetic quadrupole fields sharply degrade the confinement of non-neutral plasmas held in Malmberg-Penning traps. For example, a quadrupole magnetic field of only 0.02 G/cm doubles the diffusion rate in a trap with a 100 G axial magnetic field. Larger quadrupole fields noticeably change the shape of the plasma. The transport is greatest at an orbital resonance. These results cast doubt on plans to use magnetic quadrupole neutral atom traps to confine antihydrogen atoms created in double-well positron/antiproton Malmberg-Penning traps. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Gilson, EP (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM egilson@pppl.gov; joel@physics.berkeley.edu RI Fajans, Joel/J-6597-2016 OI Fajans, Joel/0000-0002-4403-6027 NR 19 TC 47 Z9 47 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 10 PY 2003 VL 90 IS 1 AR 015001 DI 10.1103/PhysRevLett.90.015001 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300027 PM 12570620 ER PT J AU Karny, M Grzywacz, RK Batchelder, JC Bingham, CR Gross, CJ Hagino, K Hamilton, JH Janas, Z Kulp, WD McConnell, JW Momayezi, M Piechaczek, A Rykaczewski, KP Semmes, PA Tantawy, MN Winger, JA Yu, CH Zganjar, EF AF Karny, M Grzywacz, RK Batchelder, JC Bingham, CR Gross, CJ Hagino, K Hamilton, JH Janas, Z Kulp, WD McConnell, JW Momayezi, M Piechaczek, A Rykaczewski, KP Semmes, PA Tantawy, MN Winger, JA Yu, CH Zganjar, EF TI Fine structure in proton emission from Tm-145 discovered with digital signal processing SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEAR-SPHERICAL NUCLEI; EMITTERS; DECAY; RADIOACTIVITY AB Fine structure in proton emission from the 3.1(3) mus activity of Tm-145 was discovered by using a novel technique of digital processing of overlapping recoil implantation and decay signals. Proton transitions to the ground state of Er-144 and to its first excited 2(+) state at 0.33(1) MeV with a branching ratio I-p(2(+))=9.6+/-1.5% were observed. The structure of the Tm-145 wave function and the emission process were analyzed by using particle-core vibration coupling models. C1 Univ Warsaw, IFD, PL-00681 Warsaw, Poland. Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37830 USA. Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan. Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Dept Phys, Atlanta, GA 30332 USA. Xray Instrumentat Associates, Newark, CA 94560 USA. Louisiana State Univ, Dept Phys, Baton Rouge, LA 70803 USA. Tennessee Technol Univ, Dept Phys, Cookeville, TN 38505 USA. Mississippi State Univ, Dept Phys, Mississippi State, MS 39762 USA. RP Karny, M (reprint author), Univ Warsaw, IFD, Hoza 69, PL-00681 Warsaw, Poland. NR 24 TC 45 Z9 45 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 10 PY 2003 VL 90 IS 1 AR 012502 DI 10.1103/PhysRevLett.90.012502 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300011 PM 12570604 ER PT J AU Levitov, LS Tsvelik, AM AF Levitov, LS Tsvelik, AM TI Narrow-gap Luttinger liquid in carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article AB Electron interactions reinforce minigaps induced in metallic nanotubes by an external field and turn the gap field dependence into a universal power law. An exactly solvable Gross-Neveau model with an SU(4) symmetry is derived for neutral excitations near half filling. Charge excitations, described by a sine-Gordon perturbation of Luttinger liquid theory, are composite solitons formed by the charged and neutral fields with two separate length scales. Charge compressibility at finite density, evaluated in terms of intersoliton interaction, exhibits a crossover from overlapping to nonoverlapping soliton state. Implications for the Coulomb blockade measurements are discussed. C1 MIT, Dept Phys, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP MIT, Dept Phys, Ctr Mat Sci & Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 23 TC 35 Z9 35 U1 1 U2 4 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 10 PY 2003 VL 90 IS 1 AR 016401 DI 10.1103/PhysRevLett.90.016401 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300041 PM 12570634 ER PT J AU Martin, I Mozyrsky, D Jiang, HW AF Martin, I Mozyrsky, D Jiang, HW TI A scheme for electrical detection of single-electron spin resonance SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; TRANSISTORS; HETEROSTRUCTURES AB We study a scheme for electrical detection of the spin resonance of a single-electron trapped near a field effect transistor (FET) conduction channel. In this scheme, the resonant Rabi oscillations of the trapped electron spin cause a modification of the average charge of a shallow trap, which can be detected through the change in the FET channel resistivity. We show that the dependence of the channel resistivity on the frequency of the rf field can have either peak or dip at the Larmor frequency of the electron spin in the trap. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Martin, I (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 20 TC 39 Z9 39 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 10 PY 2003 VL 90 IS 1 AR 018301 DI 10.1103/PhysRevLett.90.018301 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300059 PM 12570652 ER PT J AU McGraw, R Liu, YG AF McGraw, R Liu, YG TI Kinetic potential and barrier crossing: A model for warm cloud drizzle formation SO PHYSICAL REVIEW LETTERS LA English DT Article ID SIZE DISTRIBUTION; NUCLEATION THEORY; MICROPHYSICS; TURBULENCE; AEROSOLS; RAIN AB The kinetic potential of nucleation theory is used to describe droplet growth processes in a cloud. Drizzle formation is identified as a statistical barrier-crossing phenomenon that transforms cloud droplets to drizzle size with a rate dependent on turbulent diffusion, droplet collection, and size distribution. Steady-state and transient drizzle rates are calculated for typical cloud conditions. We find drizzle more likely under transient conditions. The model quantifies an important indirect effect of aerosols on climate-drizzle suppression in clouds of higher droplet concentration. C1 Brookhaven Natl Lab, Div Atmospher Sci, Dept Environm Sci, Upton, NY 11973 USA. RP McGraw, R (reprint author), Brookhaven Natl Lab, Div Atmospher Sci, Dept Environm Sci, Upton, NY 11973 USA. RI Liu, Yangang/H-6154-2011 NR 22 TC 17 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 10 PY 2003 VL 90 IS 1 AR 018501 DI 10.1103/PhysRevLett.90.018501 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300063 PM 12570656 ER PT J AU Shvyd'ko, YV Lerche, M Wille, HC Gerdau, E Lucht, M Ruter, HD Alp, EE Khachatryan, R AF Shvyd'ko, YV Lerche, M Wille, HC Gerdau, E Lucht, M Ruter, HD Alp, EE Khachatryan, R TI X-ray interferometry with microelectronvolt resolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID FABRY-PEROT-INTERFEROMETER; SILICON; CRYSTAL; BACKSCATTERING; RADIATION; SAPPHIRE AB We demonstrate an interferometer for hard x rays with two back-reflecting sapphire crystal mirrors-a prototype x-ray Fabry-Perot interferometer. A finesse of 15 and 0.76 mueV broad Fabry-Perot transmission resonances are measured by the time response of the interferometer. Interference patterns are observed directly in spectral dependences of reflectivity. C1 Univ Hamburg, Inst Expt Phys, D-22761 Hamburg, Germany. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Shvyd'ko, YV (reprint author), Univ Hamburg, Inst Expt Phys, D-22761 Hamburg, Germany. RI Wille, Hans-Christian/C-3881-2013 NR 20 TC 45 Z9 45 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 10 PY 2003 VL 90 IS 1 AR 013904 DI 10.1103/PhysRevLett.90.013904 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300020 PM 12570613 ER PT J AU Tu, JJ Homes, CC Strongin, M AF Tu, JJ Homes, CC Strongin, M TI Optical properties of ultrathin films: Evidence for a dielectric anomaly at the insulator-to-metal transition SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2 DIMENSIONS; GOLD-FILMS; SUPERCONDUCTIVITY; PHASE; CONDUCTIVITY; DESTRUCTION; SYSTEM; LIMIT; ONSET; RANGE AB Optical properties of ultrathin layers (<50 Angstrom) of Au and Pb quench condensed on amorphous germanium (alpha-Ge) have been measured in situ at 10 K. The development of these films from an insulating state to a metallic state is traced as a function of the film thickness as well as the sheet resistance, R-square. Of particular interest is the regime of R-square near 3000 Omega where there is an anomaly in the optical transmission. This anomaly is due to a singularity in the dielectric function when the system undergoes an electronic percolation or insulator-to-metal (I/M) transition. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Tu, JJ (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 28 TC 44 Z9 44 U1 0 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 10 PY 2003 VL 90 IS 1 AR 017402 DI 10.1103/PhysRevLett.90.017402 PG 4 WC Physics, Multidisciplinary SC Physics GA 634AR UT WOS:000180318300056 PM 12570649 ER PT J AU Chapin, DM Cohen, KP Davis, WK Kintner, EE Koch, LJ Landis, JW Levenson, M Mandil, IH Pate, AT Rockwell, T Schriesheim, A Simpson, JW Squire, A Starr, C Stone, HE Taylor, JJ Todreas, NE Wolfe, B Zebroski, EL AF Chapin, DM Cohen, KP Davis, WK Kintner, EE Koch, LJ Landis, JW Levenson, M Mandil, IH Pate, AT Rockwell, T Schriesheim, A Simpson, JW Squire, A Starr, C Stone, HE Taylor, JJ Todreas, NE Wolfe, B Zebroski, EL TI Revisiting nuclear power plant safety - Response SO SCIENCE LA English DT Letter ID IONIZING-RADIATION; CANCER C1 MPR Associates Inc, Alexandria, VA 22314 USA. GE Co, Nucl Energy Grp, Fairfield, CT 06431 USA. Bechtel Corp, San Francisco, CA USA. GPU Nucl Corp, Parsippany, NJ USA. Publ Safety Stand Grp, Weston, MA 02493 USA. World Assoc Nucl Operators, Atlanta, GA 30339 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Westinghouse Elect Corp, Pittsburgh, PA 15222 USA. Elect Power Res Inst, Palo Alto, CA 94303 USA. MIT, Cambridge, MA 02139 USA. RP Chapin, DM (reprint author), MPR Associates Inc, Alexandria, VA 22314 USA. NR 15 TC 0 Z9 0 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 10 PY 2003 VL 299 IS 5604 BP 202 EP 203 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 633LD UT WOS:000180284000019 ER PT J AU Andrus, CFT Crowe, DE Sandweiss, DH Reitz, EJ Romanek, CS Maasch, KA AF Andrus, CFT Crowe, DE Sandweiss, DH Reitz, EJ Romanek, CS Maasch, KA TI Comment on "Otolith delta O-18 record of mid-Holocene sea surface temperatures in Peru" - Response SO SCIENCE LA English DT Editorial Material ID EL-NINO; ECUADOR; CLIMATE; ONSET; BP C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Dept Geol, Athens, GA 30602 USA. Univ Maine, Dept Anthropol, Orono, ME 04469 USA. Univ Maine, Inst Quaternary & Climate Studies, Bryand Global Sci Ctr, Orono, ME 04469 USA. Univ Georgia, Dept Anthropol, Athens, GA 30602 USA. Univ Georgia, Georgia Museum Nat Hist, Athens, GA 30602 USA. Univ Georgia, Dept Geol, Athens, GA 30602 USA. Univ Maine, Dept Earth Sci, Bryand Global Sci Ctr, Orono, ME 04469 USA. RP Andrus, CFT (reprint author), Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. EM andrus@srel.edu NR 24 TC 0 Z9 0 U1 2 U2 4 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 10 PY 2003 VL 299 IS 5604 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 633LD UT WOS:000180284000046 ER PT J AU Tabet, N Faiz, M Hamdan, NM Hussain, Z AF Tabet, N Faiz, M Hamdan, NM Hussain, Z TI High resolution XPS study of oxide layers grown on Ge substrates SO SURFACE SCIENCE LA English DT Article DE germanium; oxidation; surface electronic phenomena (work function, surface potential, surface states, etc.); X-ray photoelectron spectroscopy ID GERMANIUM AB High resolution X-ray photoelectron spectroscopy (XPS) was used to analyze thin layers of germanium oxide grown on germanium substrates under various conditions. The results reveal the presence of high density of electron states located at the oxide/germanium interface that lead to the energy band bending. The surface of native oxide layers and that of thin oxide layer grown under dry oxygen correspond to GeO2 composition. Under Ar etching, lower oxidation states were revealed. Short in situ heat treatment at T = 673 K under ultrahigh vacuum leads to the removal of the oxide layer. In addition, the analysis of the layer grown at T = 653 K under dry oxygen suggests that carbides form at the oxide/substrate interface. (C) 2002 Elsevier Science B.V. All rights reserved. C1 King Fahd Univ Petr & Minerals, Dept Phys, Surface Sci Lab, Dhahran 31261, Saudi Arabia. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Tabet, N (reprint author), King Fahd Univ Petr & Minerals, Dept Phys, Surface Sci Lab, Dhahran 31261, Saudi Arabia. NR 10 TC 49 Z9 51 U1 2 U2 35 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 2003 VL 523 IS 1-2 BP 68 EP 72 AR PII S0039-6028(02)02354-3 DI 10.1016/S0039-6028(02)02354-3 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 633JA UT WOS:000180278100011 ER PT J AU Arenz, M Stamenkovic, V Schmidt, TJ Wandelt, K Ross, PN Markovic, NM AF Arenz, M Stamenkovic, V Schmidt, TJ Wandelt, K Ross, PN Markovic, NM TI The effect of specific chloride adsorption on the electrochemical behavior of ultrathin Pd films deposited on Pt(111) in acid solution SO SURFACE SCIENCE LA English DT Article DE electrochemical methods; reflection spectroscopy; metal-electrolyte interfaces; adsorption kinetics; carbon monoxide; platinum; palladium ID SINGLE-CRYSTAL SURFACES; HYDROGEN ADSORPTION; ELECTRODE-KINETICS; OXYGEN REDUCTION; H-2/CO MIXTURES; METAL-SURFACES; INITIAL-STAGES; PALLADIUM; CO; OVERLAYERS AB The electrochemical behavior of thin Pd films supported on a Pt(1 1 1) electrode is investigated by cyclic voltammetry and in situ Fourier transform infrared (FTIR) spectroscopy. It is demonstrated that in perchloric acid solution underpotential deposition of hydrogen (H-upd) and hydroxyl adsorption (OHad) is in strong competition with the adsorption of Cl- anions, the latter being present as a trace impurity in HClO4. The interaction of Cl- with Pd is rather strong, controlling the adsorption of Hupd and OHad as well as the kinetic rate of CO oxidation. The microscopic insight (the binding sites) of the adsorbed CO (COad) and the rate of CO oxidation (established from CO2 production) on Pt(1 1 1) modified with a (sub)monolayer of Pd is elucidated by means of Fourier infrared (FTIR) spectroscopy. The appearance of both the characteristic Pt(1 1 1)-COad and Pt(1 1 1)-1 ML Pd-COad stretching bands on a Pt(1 1 1) surface covered by 0.5 ML Pd confirms previous findings that the Pd atoms agglomerate into islands and that the bare Pt areas and the Pd islands behave according to their own surface chemistry. The systematic increase of the Pd surface coverage results in a gradual change in the catalytic properties of Pt(1 1 1)-xPd electrodes towards CO oxidation, from those characteristic of bare Pt(1 1 1) to those which are characteristic for Pt(1 1 1) covered with I ML of Pd. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Bonn, Inst Phys & Theoret Chem, D-53115 Bonn, Germany. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. RP Arenz, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Schmidt, Thomas/A-2586-2010; Arenz, Matthias/C-7385-2009; Arenz, Matthias/C-3195-2016 OI Schmidt, Thomas/0000-0002-1636-367X; Arenz, Matthias/0000-0001-9765-4315; Arenz, Matthias/0000-0001-9765-4315 NR 40 TC 56 Z9 57 U1 1 U2 26 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 2003 VL 523 IS 1-2 BP 199 EP 209 AR PII S0039-6028(02)02456-1 DI 10.1016/S0039-6028(02)02456-1 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 633JA UT WOS:000180278100026 ER PT J AU Dixon, DA Feller, D Francisco, JS AF Dixon, DA Feller, D Francisco, JS TI Molecular structure, vibrational frequencies, and energetics of the HCO, HOCO, and HCO2 anions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DIATOMIC DISSOCIATION-ENERGIES; GAUSSIAN-BASIS SETS; GAS-PHASE; TRIPLE EXCITATIONS; PROTON AFFINITIES; WAVE-FUNCTIONS; TRANS-HOCO; HEATS; SPECTROSCOPY; BENCHMARK AB The structures and vibrational spectra for HCO-, HOCO-, and HCO2- have been calculated at high levels of electronic structure theory. The changes in the structure of HCO- relative to neutral HCO are consistent with the predictions based on photodetachment experiments. Of the two isomers, HCO2- and HOCO-, the HCO2- anion is predicted to be the more stable. For HOCO-, the cis conformer is of lower energy as compared to the trans. Conversely, for neutral HOCO, the trans conformer is lower in energy. The electron affinity of HCO is predicted to be 0.308 eV in excellent agreement with the experimental value of 0.313 eV. The electron affinity of HOCO is predicted to be 1.42 eV and there is no known experimental measurement. The electron affinity of HCO2((2)A(1)) is predicted to be 3.51 eV as compared to the experimental value of 3.498 +/- 0.015 eV. The (2)A(1) state of HCO2 is predicted to be the ground state on the basis of theoretical calculations, which are in agreement with the experimental assignment determined from the photoelectron spectra. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. RP Dixon, DA (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, POB 99, Richland, WA 99352 USA. NR 50 TC 36 Z9 36 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 9 PY 2003 VL 107 IS 1 BP 186 EP 190 DI 10.1021/jp0220736 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 632ZL UT WOS:000180254700024 ER PT J AU Blackburn, JL Ellingson, RJ Micic, OI Nozik, AJ AF Blackburn, JL Ellingson, RJ Micic, OI Nozik, AJ TI Electron relaxation in colloidal InP quantum dots with photogenerated excitons or chemically injected electrons SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SEMICONDUCTOR NANOCRYSTALS; ENERGY RELAXATION; SPECTROSCOPY; DYNAMICS; CHARGE; PHOTOCONDUCTIVITY; COMPOSITES AB Femtosecond transient absorption spectroscopy has been used to characterize charge carrier relaxation from the second excited state (1P) to the first excited state (1S) in colloidal indium phosphide (InP) quantum dots (QDs). A three pulse experiment consisting of a visible pump, infrared pump, and white light probe was used to characterize the relaxation of photogenerated excitons, and the roles of surface chemistry and size were investigated. A two pulse experiment consisting of only the infrared pump and white light probe was used to characterize the relaxation of chemically injected electrons in the absence of holes. In the case of photogenerated excitons, two subsets of QDs were probed in the experiment, corresponding to exciton-confined and charge-separated QDs. The relaxation rates for exciton-confined and charge-separated QDs increase with decreasing QD diameter. The relaxation rates obtained for both photogenerated excitons that become charge-separated and chemically injected electrons were slowed by approximately 1 order of magnitude as compared to excitons confined to the QD core. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RP Blackburn, JL (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. RI Blackburn, Jeffrey/D-7344-2012; Ellingson, Randy/H-3424-2013; Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 NR 37 TC 54 Z9 54 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 9 PY 2003 VL 107 IS 1 BP 102 EP 109 DI 10.1021/jp026746w PG 8 WC Chemistry, Physical SC Chemistry GA 632ZN UT WOS:000180254900017 ER PT J AU Alavi, S Sorescu, DC Thompson, DL AF Alavi, S Sorescu, DC Thompson, DL TI Adsorption of HCl on single-crystal alpha-Al2O3 (0001) surface: A DFT study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; TOTAL-ENERGY CALCULATIONS; ALUMINUM-OXIDE PARTICLES; WAVE BASIS-SET; AB-INITIO; HYDROGEN-CHLORIDE; CLUSTER-MODELS; WATER CLUSTERS; ICE SURFACES; CLONO2 AB First principles calculations based on density functional theory (DFT) and the pseudopotential method have been used to study the adsorption of HCl on the basal plane of an alpha-Al2O3 crystal. The calculations accurately reproduce the energetic and structural properties of bulk alumina and of the alpha-Al2O3 (0001) surface. A 2 x 2 supercell slab model was used to study both the molecular and dissociative adsorption of HCl on the alpha-Al2O3 (0001) surface. Our calculations indicate that the dissociative configurations have adsorption energies that are at least 28 kcal/mol greater than the molecular configurations on the surface. Several ionic adsorption configurations have been investigated in which the proton is adsorbed on a nearest neighbor surface O-ion site (1-2 adsorption), or a next nearest neighbor surface O-site (1-4 adsorption). We have found that the highest binding energy corresponds to 1-2 adsorption. Analysis of the surface coverage effects shows that by increasing the coverage of 1-2 adsorbed HCl molecules to a full monolayer, the adsorption energy of each HCl decreases by about 10 kcal/mol as a result of repulsions between neighboring molecules. Implications of HCl binding to particles of alpha-Al2O3 released in the exhaust of the space shuttle booster rockets on the active chlorine-producing reaction in the stratosphere are discussed. C1 Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. RP Thompson, DL (reprint author), Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. NR 59 TC 20 Z9 20 U1 1 U2 23 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 9 PY 2003 VL 107 IS 1 BP 186 EP 195 DI 10.1021/jp021559j PG 10 WC Chemistry, Physical SC Chemistry GA 632ZN UT WOS:000180254900029 ER PT J AU Medlin, JW Allendorf, MD AF Medlin, JW Allendorf, MD TI Theoretical study of the adsorption of acetylene on the (111) surfaces of Pd, Pt, Ni, and Rh SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SUPPORTED METAL-CATALYSTS; DENSITY-FUNCTIONAL THEORY; EXTENDED HUCKEL THEORY; TEMPERATURE-PROGRAMMED DESORPTION; SELECTIVE HYDROGENATION; CARBON-MONOXIDE; VIBRATIONAL-SPECTRA; ETHYLENE ADSORPTION; MOLECULAR-DYNAMICS; PT(111) SURFACE AB Plane-wave density functional theory and extended Huckel calculations have been used to study the adsorption of acetylene and hydrogen on the (111) surface planes of Pd, Pt, Ni, and Rh. In agreement with previous experimental and computational studies, atomic hydrogen is found to preferentially adsorb in a 3-fold hollow site on each metal surface, although the potential-energy surface for hydrogen binding is apparently rather flat. Differences in the adsorption behavior of acetylene on the four surfaces are more pronounced. An adsorption structure in which C(2)H(2) is oriented above a 3-fold hollow, with its axis parallel to but tilted away from a metal-metal bond, is computed to be most stable on Pd, Pt, and Rh. On Ni(111), acetylene is found to strongly adsorb above two contiguous hollow sites, with its molecular plane perpendicular to the surface and bisecting a Ni-Ni bond. The anomalous adsorption behavior on Ni is explained using the crystal orbital Hamilton population formalism. Calculated C(2)H(2) adsorption behavior is compared with experimental studies of acetylene decomposition and hydrogenation on single-crystal surfaces. Implications for the mechanism of acetylene hydrogenation on supported metal catalysts are also discussed. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Allendorf, MD (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. EM mdallen@sandia.gov NR 60 TC 72 Z9 75 U1 4 U2 43 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 9 PY 2003 VL 107 IS 1 BP 217 EP 223 DI 10.1021/jp026555t PG 7 WC Chemistry, Physical SC Chemistry GA 632ZN UT WOS:000180254900033 ER PT J AU Stegman, DR Jellinek, AM Zatman, SA Baumgardner, JR Richards, MA AF Stegman, DR Jellinek, AM Zatman, SA Baumgardner, JR Richards, MA TI An early lunar core dynamo driven by thermochemical mantle convection SO NATURE LA English DT Article ID PROCELLARUM KREEP TERRANE; THERMAL EVOLUTION; MARE VOLCANISM; EARTHS CORE; MAGNETISM; HEAT; MOON AB Although the Moon currently has no internally generated magnetic field, palaeomagnetic data, combined with radiometric ages of Apollo samples, provide evidence for such a magnetic field from similar to3.9 to 3.6 billion years (Gyr) ago(1), possibly owing to an ancient lunar dynamo(1,2). But the presence of a lunar dynamo during this time period is difficult to explain(1-4), because thermal evolution models for the Moon 5 yield insufficient core heat flux to power a dynamo after similar to4.2 Gyr ago. Here we show that a transient increase in core heat flux after an overturn of an initially stratified lunar mantle might explain the existence and timing of an early lunar dynamo. Using a three-dimensional spherical convection model(6), we show that a dense layer, enriched in radioactive elements (a 'thermal blanket'), at the base of the lunar mantle can initially prevent core cooling, thereby inhibiting core convection and magnetic field generation. Subsequent radioactive heating progressively increases the buoyancy of the thermal blanket, ultimately causing it to rise back into the mantle. The removal of the thermal blanket, proposed to explain the eruption of thorium- and titanium-rich lunar mare basalts(7), plausibly results in a core heat flux sufficient to power a short-lived lunar dynamo. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. EM dstegman@cps.berkeley.edu RI Stegman, Dave/F-5794-2010 OI Stegman, Dave/0000-0001-8012-6145 NR 33 TC 76 Z9 79 U1 1 U2 21 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD JAN 9 PY 2003 VL 421 IS 6919 BP 143 EP 146 DI 10.1038/nature01267 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 633DR UT WOS:000180267200033 PM 12520295 ER PT J AU Chekanov, S ZEUS Collaboration Krakauer, D Magill, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Margotti, A Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kind, O Paul, E Rautenberg, J Renner, R Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Wang, M Weber, A Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Tapper, RJ Wing, M Capua, M Mastroberardino, A Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Bauerdick, LAT Behrens, U Bloch, I Borras, K Chiochia, V Dannheim, D Derrick, M Drews, G Fourletova, J Fox-Murphy, A Fricke, U Geiser, A Goebel, R Gottlicher, P Gutsche, O Haas, T Hain, W Hartner, GF Hillert, S Kotz, U Kowalski, H Kramberger, G Labes, H Lelas, D Lohr, B Mankel, R Melzer-Pellmann, IA Moritz, M Notz, D Petrucci, MC Polini, A Raval, A Schneekloth, U Selonke, F Wessoleck, H Wichmann, R Wolf, G Youngman, C Zeuner, W Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Bell, M Bussey, PJ Doyle, AT Glasman, C Hanlon, S Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Gialas, I Bodmann, B Carli, T Holm, U Klimek, K Krumnack, N Lohrmann, E Milite, M Salehi, H Stonjek, S Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Tapper, AD Cloth, P Filges, D Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Lim, H Son, D Barreiro, F Gonzalez, O Labarga, L del Peso, J Redondo, I Tassi, E Terron, J Vazquez, M Bertolin, MB Corriveau, F Ochs, A Padhi, S Stairs, DG St-Laurent, M Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, VS Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Koffeman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tiecke, H Tuning, N Velthuis, JJ Wigger's, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grzelak, G Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Heaphy, EA Oh, BY Saull, PRB Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Pavel, N Abramowicz, H Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kagawa, S Kohno, T Tawara, T Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Ferrero, MI Monaco, V Ruspa, M Sacchi, R Solano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Jones, TW Lightwood, MS Loizides, JH West, BJ Ciborowski, J Ciesielski, R Nowak, RJ Pawlak, JM Smalska, B Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Kcira, D Lammers, S Li, L Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, VW Straub, PB Bhadra, S Catterall, CD Fourletov, S Menary, S Soares, M Standage, J AF Chekanov, S ZEUS Collaboration Krakauer, D Magill, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Margotti, A Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kind, O Paul, E Rautenberg, J Renner, R Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Wang, M Weber, A Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Tapper, RJ Wing, M Capua, M Mastroberardino, A Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Bauerdick, LAT Behrens, U Bloch, I Borras, K Chiochia, V Dannheim, D Derrick, M Drews, G Fourletova, J Fox-Murphy, A Fricke, U Geiser, A Goebel, R Gottlicher, P Gutsche, O Haas, T Hain, W Hartner, GF Hillert, S Kotz, U Kowalski, H Kramberger, G Labes, H Lelas, D Lohr, B Mankel, R Melzer-Pellmann, IA Moritz, M Notz, D Petrucci, MC Polini, A Raval, A Schneekloth, U Selonke, F Wessoleck, H Wichmann, R Wolf, G Youngman, C Zeuner, W Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Bell, M Bussey, PJ Doyle, AT Glasman, C Hanlon, S Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Gialas, I Bodmann, B Carli, T Holm, U Klimek, K Krumnack, N Lohrmann, E Milite, M Salehi, H Stonjek, S Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Tapper, AD Cloth, P Filges, D Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Lim, H Son, D Barreiro, F Gonzalez, O Labarga, L del Peso, J Redondo, I Tassi, E Terron, J Vazquez, M Bertolin, MB Corriveau, F Ochs, A Padhi, S Stairs, DG St-Laurent, M Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, VS Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Koffeman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tiecke, H Tuning, N Velthuis, JJ Wigger's, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grzelak, G Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Heaphy, EA Oh, BY Saull, PRB Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Pavel, N Abramowicz, H Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kagawa, S Kohno, T Tawara, T Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Ferrero, MI Monaco, V Ruspa, M Sacchi, R Solano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Jones, TW Lightwood, MS Loizides, JH West, BJ Ciborowski, J Ciesielski, R Nowak, RJ Pawlak, JM Smalska, B Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Kcira, D Lammers, S Li, L Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, VW Straub, PB Bhadra, S Catterall, CD Fourletov, S Menary, S Soares, M Standage, J TI Study of the azimuthal asymmetry of jets in neutral current deep inelastic scattering at HERA SO PHYSICS LETTERS B LA English DT Article ID LEPTON-NUCLEON SCATTERING; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; MONTE-CARLO GENERATOR; CROSS-SECTIONS; PROTON-SCATTERING; QUANTUM CHROMODYNAMICS; PARTON DISTRIBUTIONS; HADRON-COLLISIONS; EVENT GENERATOR AB The azimuthal distribution of jets produced in the Breit frame in high-Q(2) deep inelastic e(+)p scattering has been studied with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb(-1). The measured azimuthal distribution shows a structure that is well described by next-to-leading-order QCD predictions over the Q(2) range considered, Q(2) > 125 GeV(2). (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Univ Bologna, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Ist Nazl Fis Nucl, Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, Hudson, NY 10027 USA. Inst Nucl Phys, Krakow, Poland. Stanislaw Staszic Univ Min & Met, Fac Phys & Nucl Tech, PL-30059 Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, D-2000 Hamburg, Germany. DESY, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Freiburg, Fak Phys, D-7800 Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Aegean, Dept Engn Management & Finance, Aegean, Greece. Univ Hamburg, Inst Expt Phys, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Forschungszentrum, Inst Kernphys, Julich, Germany. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Zazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Kyungpook Natl Univ, Taegu 702701, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Engn Phys Inst, Moscow 115409, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. NIKHEF, Amsterdam, Netherlands. Univ Amsterdam, Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Ewha Womans Univ, Dept Phys, Seoul, South Korea. Univ Siegen, Fachbereich Phys, D-5900 Siegen, Germany. Tel Aviv Univ, Sch Phys, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 158, Japan. Univ Turin, Dipartimento Fis Sperimentale, Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. York Univ, Dept Phys, Toronto, ON M3J 1P3, Canada. Univ Piemonte Orientale, Novara, Italy. RP Chekanov, S (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM b.foster@bristol.ac.uk RI Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Katz, Uli/E-1925-2013; Tassi, Enrico/K-3958-2015; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Doyle, Anthony/C-5889-2009; collins-tooth, christopher/A-9201-2012; Ferrando, James/A-9192-2012; Golubkov, Yury/E-1643-2012; Levchenko, B./D-9752-2012; Gladilin, Leonid/B-5226-2011; Suchkov, Sergey/M-6671-2015; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Li, Liang/O-1107-2015; Capua, Marcella/A-8549-2015; OI Katz, Uli/0000-0002-7063-4418; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Ferrando, James/0000-0002-1007-7816; Gladilin, Leonid/0000-0001-9422-8636; dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Li, Liang/0000-0001-6411-6107; PAGANIS, STATHES/0000-0002-1950-8993; Capua, Marcella/0000-0002-2443-6525; Arneodo, Michele/0000-0002-7790-7132; Gutsche, Oliver/0000-0002-8015-9622 NR 46 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 9 PY 2003 VL 551 IS 3-4 BP 226 EP 240 DI 10.1016/S0370-2693(02)03072-1 PG 15 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JF UT WOS:000180278800003 ER PT J AU Smith, MB Cizewski, JA Carpenter, MP Kondev, FG Khoo, TL Lauritsen, T Janssens, RVF Abu Saleem, K Ahmad, I Amro, H Danchev, M Davids, CN Hartley, DJ Heinz, A Lister, CJ Ma, WC Poli, GL Ressler, JJ Reviol, W Riedinger, LL Seweryniak, D Wiedenhover, I AF Smith, MB Cizewski, JA Carpenter, MP Kondev, FG Khoo, TL Lauritsen, T Janssens, RVF Abu Saleem, K Ahmad, I Amro, H Danchev, M Davids, CN Hartley, DJ Heinz, A Lister, CJ Ma, WC Poli, GL Ressler, JJ Reviol, W Riedinger, LL Seweryniak, D Wiedenhover, I TI Limits of the energy-spin phase space beyond the proton drip line: entry distributions of Pt and Au isobars SO PHYSICS LETTERS B LA English DT Article ID SHAPE COEXISTENCE; RADIOACTIVITY; MECHANISM; ISOTOPES; NUCLEI; REGION; BANDS AB Entry distributions in angular momentum and excitation energy have been measured for several very proton-rich isotopes of Pt and Au. This is the first systematic study of the energy-spin phase space for nuclei near and beyond the proton drip line. Comparisons are made between the distributions associated with proton-unbound An nuclei and more stable Pt isobars. In Au-173 the first evidence is seen for the limits of excitation energy and angular momentum which a nucleus beyond the proton drip line can sustain. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. Argonne Natl Lab, Dept Phys, Argonne, IL 60439 USA. IIT, Dept Phys, Chicago, IL 60616 USA. Mississippi State Univ, Dept Phys, Mississippi State, MS 39762 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. RP Smith, MB (reprint author), TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada. EM mbsmith@triumf.ca RI Ressler, Jennifer Jo/F-2279-2010; Heinz, Andreas/E-3191-2014; Carpenter, Michael/E-4287-2015; OI Carpenter, Michael/0000-0002-3237-5734; Smith, Martin/0000-0003-0834-1574 NR 23 TC 1 Z9 1 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 9 PY 2003 VL 551 IS 3-4 BP 262 EP 268 AR PII S0370-2693(02)03051-4 DI 10.1016/S0370-2693(02)03051-4 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JF UT WOS:000180278800007 ER PT J AU Barton, CJ Caprio, MA Shapira, D Zamfir, NV Brenner, DS Gill, RL Lewis, TA Cooper, JR Casten, RF Beausang, CW Krucken, R Novak, JR AF Barton, CJ Caprio, MA Shapira, D Zamfir, NV Brenner, DS Gill, RL Lewis, TA Cooper, JR Casten, RF Beausang, CW Krucken, R Novak, JR TI B(E2) values from low-energy Coulomb excitation at an ISOL facility: the N=80, 82 Te isotopes SO PHYSICS LETTERS B LA English DT Article ID YRAST EXCITATIONS; DETECTOR; NUCLEI; TE-136; BEAM AB B(E2; 0(1)(+)--> 2(1)(+)) values for the unstable, neutron-rich nuclei Te-132,Te-134 were determined through Coulomb excitation, in inverse kinematics, of accelerated. beams of these nuclei. The systematics of measured B(E2) values from the ground state to the first excited state have been extended to the N = 82 shell closure in the Te nuclei and have been compared with the predictions of different theories. The measurements were performed at the Holifield Radioactive Ion Beam Facility (HRIBF) using the GRAFIK detector. The success of this approach, which couples a 5.7% efficient through-well Nal(TI) gamma-ray detector with thin foil microchannel plate beam detectors, also demonstrates the feasibility for Coulomb excitation studies of neutron-rich nuclei even further from the valley of beta stability, both at present-generation ISOL facilities and at the proposed Rare Isotope Accelerator. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Yale Univ, Wright Nucl Struct Lab, New Haven, CT 06520 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Clark Univ, Worcester, MA 01610 USA. Natl Inst Phys & Nucl Engn, Bucharest, Romania. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37831 USA. RP Barton, CJ (reprint author), CCLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. EM c.j.barton@dl.ac.uk RI Zamfir, Nicolae Victor/F-2544-2011; Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 34 TC 25 Z9 25 U1 0 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 9 PY 2003 VL 551 IS 3-4 BP 269 EP 276 AR PII S0370-2693(02)03066-6 DI 10.1016/S0370-2693(02)03066-6 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JF UT WOS:000180278800008 ER PT J AU Bass, SA Muller, B Srivastava, DK AF Bass, SA Muller, B Srivastava, DK TI Parton rescattering and screening in Au plus Au collisions at RHIC SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; TRANSVERSE-MOMENTUM; GAUGE-THEORIES; QCD; CASCADES; DYNAMICS; MODEL AB We study the microscopic dynamics of quarks and gluons in relativistic heavy ion collisions in the framework of the Parton Cascade Model. We use lowest order perturbative QCD cross sections with fixed lower momentum cutoff p(T)(min). We calculate the time-evolution of the Debye-screening mass muD for Au + Au collisions at roots = 200 GeV per nucleon pair. The screening mass is used to determine a lower limit for the allowed range of p(T)(min). We also determine the energy density reached through T hard and semi-hard processes at RHIC, obtain a lower bound for the rapidity density of charged hadrons produced by semi-hard interactions, and analyze the extent of perturbative rescattering among partons. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Duke Univ, Dept Phys, Durham, NC 27708 USA. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. RP Bass, SA (reprint author), Duke Univ, Dept Phys, Durham, NC 27708 USA. OI Bass, Steffen/0000-0002-9451-0954 NR 27 TC 61 Z9 61 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 9 PY 2003 VL 551 IS 3-4 BP 277 EP 283 AR PII S0370-2693(02)03068-X DI 10.1016/S0370-2693(02)03068-X PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JF UT WOS:000180278800009 ER PT J AU Close, FE Lipkin, HJ AF Close, FE Lipkin, HJ TI Puzzles in Cabibbo-suppressed charm decays SO PHYSICS LETTERS B LA English DT Article ID MESON AB We identify two Cabibbo suppressed D+ decay modes with anomalously high branching ratios which are not simply explained by any model. All standard model diagrams that can contribute to these decays are related by symmetries to diagrams for other decays that do not show any such enhancement. If these high branching ratios are confirmed by more precise experiments, they may require new physics to explain them. Anomalies in D-s decays and tests for possible violation of G-parity are discussed. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Oxford, Dept Theoret Phys, Oxford OX1 3NP, England. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Close, FE (reprint author), Univ Oxford, Dept Theoret Phys, Keble Rd, Oxford OX1 3NP, England. NR 6 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 9 PY 2003 VL 551 IS 3-4 BP 337 EP 342 AR PII S0370-2693(02)03064-2 DI 10.1016/S0370-2693(02)03064-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JF UT WOS:000180278800017 ER PT J AU Meyers, JS Chumbley, S Laabs, F Pecharsky, AO AF Meyers, JS Chumbley, S Laabs, F Pecharsky, AO TI TEM analysis of Gd-5(SixGe1-x)4, where x=1/2 SO ACTA MATERIALIA LA English DT Article DE transmission electron microscopy; rare earth; phase transition; ferroelastic; Gd5Si2Ge2 ID GIANT; GD-5(SI2GE2); TRANSITION AB The material Gd-5(SixGe1-x)(4), with x=1/2 was investigated using transmission electron microscopy. The material possesses a complex crystallographic structure and undergoes a unique, reversible, transformation at low temperatures and an irreversible high temperature transformation. The high, room and low temperature microstructures of arc-melted and heat treated samples are reported. Direct observation of the transformation with a discussion on the mechanism of the reversible, low temperature, phase transformation is detailed. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Chumbley, S (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 16 TC 7 Z9 9 U1 0 U2 2 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 8 PY 2003 VL 51 IS 1 BP 61 EP 70 DI 10.1016/S1359-6454(02)00227-6 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 636NG UT WOS:000180461800005 ER PT J AU Schuh, CA Nieh, TG AF Schuh, CA Nieh, TG TI A nanoindentation study of serrated flow in bulk metallic glasses SO ACTA MATERIALIA LA English DT Article ID MECHANICAL-PROPERTIES; AMORPHOUS-ALLOYS; DEFORMATION MECHANISMS; PLASTIC INSTABILITIES; THIN-FILMS; INDENTATION; BEHAVIOR; FRACTURE; CREEP; PRESSURE AB Plastic deformation of two Pd- and two Zr-based bulk metallic glasses (BMGs) is investigated through the use of nanoindentation, which probes mechanical properties at the length scale of shear bands, the carriers of plasticity in such alloys. These materials exhibit serrated flow during nanoindentation, manifested as a stepped load-displacement curve punctuated by discrete bursts of plasticity. These discrete "pop-in" events correspond to the activation of individual shear bands, and the character of serrations is strongly dependent on the indentation loading rate; slower indentation rates promote more conspicuous serrations, and rapid indentations suppress serrated flow. Analysis of the experimental data reveals a critical applied strain rate, above which serrated flow is completely suppressed. Furthermore, careful separation of the plastic and elastic contributions to deformation reveals that, at sufficiently low indentation rates, plastic deformation occurs entirely in discrete events of isolated shear banding, while at the highest rates, deformation is continuous, without any evidence of discrete events at any size scale. All of the present results are consistent with a kinetic limitation for shear bands, where at high rates, a single shear band cannot accommodate the imposed strain rapidly enough, and consequently multiple shear bands must operate simultaneously. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94550 USA. RP Schuh, CA (reprint author), MIT, Dept Mat Sci & Engn, Room 8-211, Cambridge, MA 02139 USA. RI Schuh, Christopher/C-7947-2009; Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 56 TC 378 Z9 400 U1 22 U2 177 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 8 PY 2003 VL 51 IS 1 BP 87 EP 99 DI 10.1016/S1359-6454(02)00303-8 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 636NG UT WOS:000180461800007 ER PT J AU Zhang, KM Parker, GA Kouri, DJ Hoffman, DK Iyengar, SS AF Zhang, KM Parker, GA Kouri, DJ Hoffman, DK Iyengar, SS TI Quantum reactive scattering in three dimensions using adiabatically adjusting principal axis hyperspherical coordinates: Periodic distributed approximating functional method for surface functions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; INTEGRAL CROSS-SECTIONS; DISCRETE VARIABLE REPRESENTATION; TOTAL ANGULAR-MOMENTUM; REACTION PROBABILITIES; MECHANICAL CALCULATION; DELAY TIMES; F+H2->HF+H AB Periodic distributed approximating functionals are proposed and used to obtain a coordinate representation for the adiabatically adjusting principal axis hyperspherical coordinate kinetic energy operator. The approach is tested and accurate results for adiabatic surface functions for the reaction F+H(2)-->HF+H are calculated and compared to those of some existing methods. (C) 2003 American Institute of Physics. C1 Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Utah, Henry Eyring Ctr Theoret Chem, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. RP Zhang, KM (reprint author), Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. EM parker@phyast.nhn.ou.edu RI Parker, Gregory/A-4327-2009; Iyengar, Srinivasan/B-5570-2017 OI Parker, Gregory/0000-0002-0225-8887; Iyengar, Srinivasan/0000-0001-6526-2907 NR 46 TC 2 Z9 2 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 2003 VL 118 IS 2 BP 569 EP 581 DI 10.1063/1.1526835 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 627RY UT WOS:000179949700013 ER PT J AU Holroyd, RA Itoh, K Nishikawa, M AF Holroyd, RA Itoh, K Nishikawa, M TI Density inhomogeneities and electron mobility in supercritical xenon SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DEFORMATION-POTENTIAL-THEORY; RARE-GAS MODERATORS; EXCESS ELECTRONS; FLUID ARGON; LIQUID ARGON; KRYPTON; FIELD; TEMPERATURE; DEPENDENCE; TRANSPORT AB The low-field mobility of electrons in supercritical Xe has been measured isothermally as a function of density above the critical temperature (289.7 K). At 293 K the mobility varies from a high of 890 cm(2)/V s at 9.2x10(21) atoms/cm(3) to a minimum value of 4.6 cm(2)/V s at a density of 3.5x10(21) atoms/cm(3), which is just below the critical density. The density dependence of the mobility is reasonably well predicted by the deformation potential model if the adiabatic compressibility is used to characterize the electron-medium interactions. Approximate agreement indicates that electrons are quasifree in supercritical xenon. (C) 2003 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Tokyo, Dept Pure & Appl Sci, Tokyo 1538902, Japan. Kanagawa Inst Technol, Fac Engn, Atsugi, Kanagawa 2430292, Japan. RP Holroyd, RA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 25 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 2003 VL 118 IS 2 BP 706 EP 710 DI 10.1063/1.1527944 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 627RY UT WOS:000179949700025 ER PT J AU Heine, D Wu, DT Curro, JG Grest, GS AF Heine, D Wu, DT Curro, JG Grest, GS TI Role of intramolecular energy on polyolefin miscibility: Isotactic polypropylene/polyethylene blends SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTEGRAL-EQUATION THEORY; MONTE-CARLO SIMULATIONS; MOLECULAR-DYNAMICS SIMULATIONS; MULTICOMPONENT POLYMER BLENDS; PRESSURE-VOLUME-TEMPERATURE; UNITED-ATOM DESCRIPTION; X-RAY-SCATTERING; TRANSFERABLE POTENTIALS; MONOMER STRUCTURE; EXCESS ELECTRONS AB Self-consistent polymer reference interaction site model (PRISM) calculations and molecular dynamics (MD) simulations were performed for a blend of isotactic polypropylene (iPP) and polyethylene (PE) at various compositions and chain lengths. United atom models were used for both components. Both PRISM theory and MD simulations predicted that the change in intramolecular energy going from the melt to the blend for each species was a significant positive contribution to the total mixing energy. Furthermore, this intramolecular heat of mixing was dominated by the torsional and van der Waals contributions. Constant pressure MD simulations indicated that, with the united atom parameters used, the iPP/PE blend had essentially zero volume change of mixing. MD simulations were used to compute the partial structure factors for the blend and together with the standard random phase approximation analysis were used to estimate the small angle neutron scattering (SANS) chi parameter. Good agreement was found between estimates from PRISM and MD of both the enthalpic and SANS chi parameters. (C) 2003 American Institute of Physics. C1 Colorado Sch Mines, Dept Chem & Geochem, Dept Chem Engn, Golden, CO 80401 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wu, DT (reprint author), Colorado Sch Mines, Dept Chem & Geochem, Dept Chem Engn, Golden, CO 80401 USA. NR 35 TC 32 Z9 32 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 2003 VL 118 IS 2 BP 914 EP 924 DI 10.1063/1.1516591 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 627RY UT WOS:000179949700045 ER PT J AU Rodriguez, JA Dvorak, J Jirsak, T Liu, G Hrbek, J Aray, Y Gonzalez, C AF Rodriguez, JA Dvorak, J Jirsak, T Liu, G Hrbek, J Aray, Y Gonzalez, C TI Coverage effects and the nature of the metal-sulfur bond in S/Au(111): High-resolution photoemission and density-functional studies SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; ELECTRONIC-STRUCTURE CALCULATIONS; SCANNING-TUNNELING-MICROSCOPY; ABSORPTION FINE-STRUCTURE; TOTAL-ENERGY CALCULATIONS; DEFINED GOLD PARTICLES; CATALYTIC ACTIVITY; POPULATION ANALYSIS; ULTRAHIGH-VACUUM; AU(111) SURFACE AB The bonding of sulfur to surfaces of gold is an important subject in several areas of chemistry, physics, and materials science. Synchrotron-based high-resolution photoemission and first-principles density-functional (DF) slab calculations were used to study the interaction of sulfur with a well-defined Au(111) surface and polycrystalline gold. Our experimental and theoretical results show a complex behavior for the sulfur/Au(111) interface as a function of coverage and temperature. At small sulfur coverages, the adsorption of S on fcc hollow sites of the gold substrate is energetically more favorable than adsorption on bridge or a-top sites. Under these conditions, S behaves as a weak electron acceptor but substantially reduces the density-of-states that gold exhibits near the Fermi edge. As the sulfur coverage increases, there is a weakening of the Au-S bonds (with a simultaneous reduction in the Au --> S charge transfer and a modification in the S sp hybridization) that facilitates changes in adsorption site and eventually leads to S-S bonding. At sulfur coverages above 0.4 ML, S-2 and not atomic S is the more stable species on the gold surface. Formation of S-n (n > 2) species occurs at sulfur coverages higher than a monolayer. Very similar trends were observed for the adsorption of sulfur on polycrystalline surfaces of gold. The S atoms bonded to Au(111) display a unique mobility/reactivity not seen on surfaces of early or late transition metals. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11953 USA. Inst Venezolano Invest Cient, Ctr Quim, A-1020 Vienna, Austria. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Brookhaven Natl Lab, Dept Chem, Upton, NY 11953 USA. EM rodrigez@bnl.gov RI Hrbek, Jan/I-1020-2013 NR 91 TC 133 Z9 134 U1 2 U2 32 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 8 PY 2003 VL 125 IS 1 BP 276 EP 285 DI 10.1021/ja021007e PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 632MQ UT WOS:000180227400046 PM 12515530 ER PT J AU Wang, XB Dacres, JE Yang, X Broadus, KM Lis, L Wang, LS Kass, SR AF Wang, XB Dacres, JE Yang, X Broadus, KM Lis, L Wang, LS Kass, SR TI Photodetachment of zwitterions: Probing intramolecular Coulomb repulsion and attraction in the gas phase using pyridinium dicarboxylate anions SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID OROTIDINE 5'-MONOPHOSPHATE DECARBOXYLASE; MULTIPLY-CHARGED ANIONS; ENZYME ACTIVE-SITE; MOLECULAR RECOGNITION; ION-PAIRS; CATALYSIS; ACID; CYCLOADDITION; DISSOCIATION; SPECIFICITY AB Zwitterions are critically important in many biological transformations and are used in numerous chemical processes. The consequences of electrostatic effects on reactivity and physical properties, however, are largely unknown. In this work, we report the results of negative ion photoelectron spectra of nine isomeric pyridinium dicarboxylate zwitterions and three nonzwitterionic methoxycarbonylpyridine carboxylate isomers (-O(2)CPyrCO(2)CH(3)). Information about the intramolecular electrostatic interactions was directly obtained from the photoelectron spectra. The adiabatic and vertical detachment energies were measured and understood in terms of intramolecular Coulombic forces. Calculations at the B3LYP and CCSD(T) level were performed and compared to the experimental electron binding energies. Structures, relative stabilities, and the electron detachment sites also were obtained from the calculations. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, W R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. NR 54 TC 38 Z9 38 U1 1 U2 10 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 8 PY 2003 VL 125 IS 1 BP 296 EP 304 DI 10.1021/ja028204y PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 632MQ UT WOS:000180227400048 PM 12515532 ER PT J AU Maye, MM Luo, J Lin, YH Engelhard, MH Hepel, M Zhong, CJ AF Maye, MM Luo, J Lin, YH Engelhard, MH Hepel, M Zhong, CJ TI X-ray photoelectron spectroscopic study of the activation of molecularly-linked gold nanoparticle catalysts SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; CLUSTER MOLECULES; FUEL-CELLS; CORE; OXIDATION; AU; METHANOL; REACTIVITIES; DISULFIDES; ELECTRODES AB This paper reports the results of a study on the activation of core-shell assembled gold nanoparticle catalysts using X-ray photoelectron spectroscopy (XPS). The goal is to determine the surface reconstitution of the nanostructured catalysts upon electrochemical activation for the electrocatalytic oxidation of methanol. The decanethiolate-capped gold nanoparticles of 2-5 nm core sizes were assembled as catalyst thin films on electrode surfaces using 1,9-nonanedithiol and 11-mercaptoundecanoic acid as model molecular linkers. The XPS results have provided two important insights into the surface reconstitution of the activated nanostructure. First, the capping/linking thiolates or dithiolates are partially removed to produce the catalytic access, with the degree of removal being dependent on the nature of the molecular linker. Second, oxygenated species are detected on the activated gold nanocrystals, demonstrating the formation of surface gold oxide and its participation in the electrocatalytic oxidation of methanol. The findings are also correlated with results from studies of surface microscopic morphology and interfacial mass flux and provide further insights into issues related to the design and preparation of highly active nanostructured gold catalysts. C1 SUNY Binghamton, Dept Chem, Binghamton, NY 13902 USA. Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. SUNY Coll Potsdam, Dept Chem, Potsdam, NY 13676 USA. RP Zhong, CJ (reprint author), SUNY Binghamton, Dept Chem, Binghamton, NY 13902 USA. RI Engelhard, Mark/F-1317-2010; Lin, Yuehe/D-9762-2011; Zhong, Chuan-Jian/D-3394-2013; OI Lin, Yuehe/0000-0003-3791-7587; Engelhard, Mark/0000-0002-5543-0812 NR 39 TC 82 Z9 82 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JAN 7 PY 2003 VL 19 IS 1 BP 125 EP 131 DI 10.1021/1a0264116 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 634GW UT WOS:000180332500019 ER PT J AU Frink, LJD Salinger, AG AF Frink, LJD Salinger, AG TI Interactions and assembly of simple solvated polymers models SO LANGMUIR LA English DT Article ID DENSITY-FUNCTIONAL THEORY; MONTE-CARLO; FORCES; SOLVENT; DNA; FLUIDS AB In this paper we discusses the application of a three-dimensional implementation of a geometry-based nonlocal density functional theory to the interactions between rigid polymers in solution. Deoxyribonucleic acid (DNA) provides inspiration for the three simple model polymers (cylindrical, bead chain, and periodic) we consider; however the results are more generally applicable to rigid polymers such as liquid crystals. The calculations show that fine details of polymer surface structure play a critical role in determining the solvation energy landscape. This solvation energy landscape in turn controls routes for assembly of bundles of macromolecules. This approach provides a new level of molecular insight into interactions in solvated polymer systems with wide applications to both industrial and biological polymers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Frink, LJD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 2 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JAN 7 PY 2003 VL 19 IS 1 BP 182 EP 185 DI 10.1021/1a026212m PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 634GW UT WOS:000180332500026 ER PT J AU Miao, JW Hodgson, KO Ishikawa, T Larabell, CA LeGros, MA Nishino, Y AF Miao, JW Hodgson, KO Ishikawa, T Larabell, CA LeGros, MA Nishino, Y TI Imaging whole Escherichia coli bacteria by using single-particle x-ray diffraction SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID MICROSCOPY; RESOLUTION AB We report the first experimental recording, to our knowledge, of the diffraction pattern from intact Escherichia coli bacteria using coherent x-rays with a wavelength of 2 A. By using the oversampling phasing method, a real space image at a resolution of 30 nm was directly reconstructed from the diffraction pattern. An R factor used for characterizing the quality of the reconstruction was in the range of 5%, which demonstrated the reliability of the reconstruction process. The distribution of proteins inside the bacteria labeled with manganese oxide has been identified and this distribution confirmed by fluorescence microscopy images. Compared with lens-based microscopy, this diffraction-based imaging approach can examine thicker samples, such as whole cultured cells, in three dimensions with resolution limited only by radiation damage. Looking forward, the successful recording and reconstruction of diffraction patterns from biological samples reported here represent an important step toward the potential of imaging single biomolecules at near-atomic resolution by combining single-particle diffraction with x-ray free electron lasers. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RIKEN, SPring 8, Mikazuki, Hyogo 6795148, Japan. Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. EO Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. EO Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Miao, JW (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RI Ishikawa, Tetsuya/I-4775-2012; Nishino, Yoshinori/A-9927-2008 OI Ishikawa, Tetsuya/0000-0002-6906-9909; Nishino, Yoshinori/0000-0002-7215-8013 NR 22 TC 183 Z9 186 U1 1 U2 18 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 7 PY 2003 VL 100 IS 1 BP 110 EP 112 DI 10.1073/pnas.232691299 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 633WG UT WOS:000180307100021 PM 12518059 ER PT J AU Park, JY Phaneuf, RJ AF Park, JY Phaneuf, RJ TI Time response in tunneling to a pn junction SO APPLIED PHYSICS LETTERS LA English DT Article ID FORCE MICROSCOPY; TRAPPED CHARGE; SIO2; SILICON AB We report on the variation in the response time in scanning tunneling microscopy (STM) measurements across a Si pn junction, and its effect on STM images of such devices. The response time of the tip height subsequent to a stepwise change in the voltage at a fixed demanded current varies by almost two orders of magnitude across the junction, with the slowest response of nearly 80 ms corresponding to the tip-sample junction in strong inversion. Measurements at decreasing separation show an increase in response time up to a saturation point, consistent with screening due to the inversion charge. The slow response in regions where the tip-sample junction is in inversion explains observations of anomalously deep features in STM topography images and scan direction-dependent features in STM conductance maps. (C) 2003 American Institute of Physics. C1 Lab Phys Sci, College Pk, MD 20740 USA. Univ Maryland, College Pk, MD 20740 USA. RP Park, JY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RI Park, Jeong Young/A-2999-2008 NR 14 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 6 PY 2003 VL 82 IS 1 BP 64 EP 66 DI 10.1063/1.1533849 PG 3 WC Physics, Applied SC Physics GA 630WV UT WOS:000180134100022 ER PT J AU Lee, DR Srajer, G Fitzsimmons, MR Metlushko, V Sinha, SK AF Lee, DR Srajer, G Fitzsimmons, MR Metlushko, V Sinha, SK TI Polarized neutron scattering from ordered magnetic domains on a mesoscopic permalloy antidot array SO APPLIED PHYSICS LETTERS LA English DT Article ID FILMS AB Using polarized neutrons, we measured grazing-incidence scattering from a mesoscopic permalloy antidot array. A kinematical theory incorporating a highly anisotropic resolution function was developed to interpret the data. Calculations for a magnetic domain structure of the antidot array were obtained from a micromagnetic simulation and show good agreement with the experiment. In contrast, calculations based on a model of uniform magnetization between the antidots were not found to be consistent with the data. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Lee, DR (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RI Lujan Center, LANL/G-4896-2012 NR 12 TC 19 Z9 19 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 6 PY 2003 VL 82 IS 1 BP 82 EP 84 DI 10.1063/1.1534919 PG 3 WC Physics, Applied SC Physics GA 630WV UT WOS:000180134100028 ER PT J AU Jiang, CS Hasoon, FS Moutinho, HR Al-Thani, HA Romero, MJ Al-Jassim, MM AF Jiang, CS Hasoon, FS Moutinho, HR Al-Thani, HA Romero, MJ Al-Jassim, MM TI Direct evidence of a buried homojunction in Cu(In,Ga)Se-2 solar cells SO APPLIED PHYSICS LETTERS LA English DT Article ID BATH DEPOSITION PROCESS; CONDUCTION-BAND OFFSET; FORCE MICROSCOPY; THIN-FILMS; BUFFER LAYERS; EFFICIENCY; CU(INGA)SE-2; PERFORMANCE AB The built-in electrical potential of Cu(In,Ga)Se-2 (CIGS) solar cells was measured quantitatively and resolved spatially using scanning Kelvin probe microscopy. Profiles of the electrical potential along cross sections of the device demonstrate that the p-n junction is a buried homojunction, and the p/n boundary is located 30-80 nm from the CIGS/CdS interface in the CIGS film. The built-in electric field terminates at the CIGS/CdS interface, indicating that the CdS and ZnO layers of the device structure are inactive for the collection of photoexcited carriers. (C) 2003 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Jiang, CS (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI jiang, chun-sheng/F-7839-2012 NR 22 TC 71 Z9 73 U1 2 U2 34 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 6 PY 2003 VL 82 IS 1 BP 127 EP 129 DI 10.1063/1.1534417 PG 3 WC Physics, Applied SC Physics GA 630WV UT WOS:000180134100043 ER PT J AU Poe, GR Rector, DM Harper, RM AF Poe, GR Rector, DM Harper, RM TI State-dependent columnar organization of dorsal hippocampal activity in the freely-behaving cat SO BEHAVIOURAL BRAIN RESEARCH LA English DT Article DE hippocampus; optical imaging; slabs; lamellae; state; sleep ID SLEEP; PATTERNS; CORTEX AB We examined reflected light images from the dorsal hippocampus in freely-behaving cats to assess the topographical organization of neural activity expressed during sleep-waking states. Reflectance patterns, organized as columns along the CA3-CA1 axis which appeared during rapid eye movement sleep (REM) and waking states, were compared to baseline periods collected during quiet sleep (QS). The columns were not static across states or behaviors within a state, but showed inversion in activation/inactivation patterns, and narrowed or widened over time. A correlation between state-dependence and reflectance patterns emerged, with transitions to active waking and REM most likely exhibiting enhanced columnar patterning, relative to QS. No columnar patterns appeared in overlying neocortical areas or in control media. The columnar patterns suggest a highly structured functional state-dependent organization in the dorsal hippocampus, as has been previously predicted by anatomical studies. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Angeles, Dept Neurobiol, Brain Res Inst, Los Angeles, CA 90095 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Michigan, Dept Anesthesiol, Ann Arbor, MI 48109 USA. RP Harper, RM (reprint author), Univ Calif Los Angeles, Dept Neurobiol, Brain Res Inst, 10833 Le Conte Ave, Los Angeles, CA 90095 USA. OI Poe, Gina/0000-0003-3388-2858 FU NHLBI NIH HHS [HL-22418] NR 26 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-4328 J9 BEHAV BRAIN RES JI Behav. Brain Res. PD JAN 6 PY 2003 VL 138 IS 1 BP 107 EP 112 AR PII S0166-4328(02)00233-4 DI 10.1016/S0166-4328(02)00233-4 PG 6 WC Behavioral Sciences; Neurosciences SC Behavioral Sciences; Neurosciences & Neurology GA 635YZ UT WOS:000180428900010 PM 12493634 ER PT J AU Moran, AM Kelley, AM Tretiak, S AF Moran, AM Kelley, AM Tretiak, S TI Excited state molecular dynamics simulations of nonlinear push-pull chromophores SO CHEMICAL PHYSICS LETTERS LA English DT Article ID BOND-LENGTH ALTERNATION; DONOR-ACCEPTOR POLYENES; OPTICAL PROPERTIES; CONJUGATED MOLECULES; ORGANIC-MOLECULES; P-NITROANILINE; SOLVENT; MODEL; POLARIZABILITIES; HYPERPOLARIZABILITY AB Julolidinemalononitrile, p-nitroaniline, and julolidinyl-n-N,N'-diethylthiobarbituric acid are studied with ground and excited state molecular dynamics simulations in conjunction with the collective electronic oscillator formalism and Onsager's cavity model. Ground and excited state geometries are calculated in the gas phase and four solvents. The results are interpreted in the context of a two-state valence bond model for charge-transfer transitions of conjugated organic molecules, and are compared to recent resonant Raman experimental results. The calculated geometries are qualitatively consistent with both the two-state model and experiment. In addition, calculated transition density matrices are presented to visualize the changes in charge distribution accompanying photoexcitation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Div Theoret, Los Alamos, NM 87545 USA. Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA. RP Tretiak, S (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. RI Tretiak, Sergei/B-5556-2009 OI Tretiak, Sergei/0000-0001-5547-3647 NR 35 TC 37 Z9 37 U1 0 U2 9 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 6 PY 2003 VL 367 IS 3-4 BP 293 EP 307 AR PII S0009-2614(02)01583-X DI 10.1016/S0009-2614(02)01583-X PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 634PH UT WOS:000180349100007 ER PT J AU Gerisch, M Krumper, JR Bergman, RG Tilley, TD AF Gerisch, M Krumper, JR Bergman, RG Tilley, TD TI Rhodium(III) and rhodium(II) complexes of novel bis(oxazoline) pincer ligands SO ORGANOMETALLICS LA English DT Article ID KHARASCH ADDITION-REACTION; ONE-ELECTRON ACTIVATION; X-RAY STRUCTURE; CRYSTAL-STRUCTURE; BITE ANGLE; C-H; 2,6-BIS<(DIMETHYLAMINO)METHYL>PHENYL-N,N',C COMPLEXES; BOND FORMATION; CATALYSTS; DEHYDROGENATION AB A series of novel C-2-symmetric bisoxazoline ligands (benbox and benboxMe(2)) have been prepared. A variety of coordinatively unsaturated rhodium(III) complexes (3a-g, 4a-g) have been isolated. Trapping reactions of the agostically stabilized complex [RhCl2{(S,S)-ib-benbox(Me-2)}] (4d) are described. Metal-to-aryl methyl migration reactions are described for the complex [RhMe{(S,S)-ip-benbox(Me-2)}] [BArf] (11c). Full characterization details and reactivity studies of air-stable, isolable, mononuclear, paramagnetic rhodium(II) complexes [RhCl2{(S,S)-tb-benbox(Me-2)}(H)] (15e) and [RhCl2{dm-benbox(Me-2)H}] (15g) are reported. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94702 USA. Univ Calif Berkeley, CNDOS, Berkeley, CA 94702 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94702 USA. RP Univ Calif Berkeley, Dept Chem, Berkeley, CA 94702 USA. EM bergman@cchem.berkeley.edu; tdtilley@socrates.berkeley.edu NR 78 TC 54 Z9 54 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 EI 1520-6041 J9 ORGANOMETALLICS JI Organometallics PD JAN 6 PY 2003 VL 22 IS 1 BP 47 EP 58 DI 10.1021/om0207562 PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 631ZE UT WOS:000180197500009 ER PT J AU Milliron, DJ Alivisatos, AP Pitois, C Edder, C Frechet, JMJ AF Milliron, DJ Alivisatos, AP Pitois, C Edder, C Frechet, JMJ TI Electroactive surfactant designed to mediate electron transfer between CdSe nanocrystals and organic semiconductors SO ADVANCED MATERIALS LA English DT Article ID HETEROSUPRAMOLECULAR CHEMISTRY; ELECTROLUMINESCENCE; COMPOSITES; KINETICS; DYNAMICS; GROWTH AB An electroactive pentathiophene surfactant containing a phosphonic acid head group was designed and shown to provide strong binding to the surface of a CdSe nanocrystal and facilitate charge transfer between the nanocrystal and an organic semiconducting matrix (see Figure). Incorporation into organic-inorganic heterojunction solar cells could improve the efficiency of these promising devices. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94702 USA. RP Alivisatos, AP (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Milliron, Delia/D-6002-2012; Alivisatos , Paul /N-8863-2015; OI Alivisatos , Paul /0000-0001-6895-9048; Frechet, Jean /0000-0001-6419-0163 NR 20 TC 153 Z9 155 U1 5 U2 35 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 3 PY 2003 VL 15 IS 1 BP 58 EP + DI 10.1002/adma.200390011 PG 5 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 638VT UT WOS:000180593500010 ER PT J AU Anton, PA Mitsuyasu, RT Deeks, SG Scadden, DT Wagner, B Huang, C Macken, C Richman, DD Christopherson, C Borellini, F Lazar, R Hege, KM AF Anton, PA Mitsuyasu, RT Deeks, SG Scadden, DT Wagner, B Huang, C Macken, C Richman, DD Christopherson, C Borellini, F Lazar, R Hege, KM TI Multiple measures of HIV burden in blood and tissue are correlated with each other but not with clinical parameters in aviremic subjects SO AIDS LA English DT Article DE HIV-1; quantitative; reservoirs; mucosa; tissue; gastrointestinal-associated lymphoid tissue; viral load; clinical trials; assay correlation; assay variability ID IMMUNODEFICIENCY-VIRUS INFECTION; ACTIVE ANTIRETROVIRAL THERAPY; T-CELLS; MONONUCLEAR-CELLS; LATENT RESERVOIR; LYMPHOID-TISSUE; PLASMA; RNA; LYMPHOCYTES; REPLICATION AB Objectives: To determine the levels of residual HIV DNA and RNA in blood and gut reservoirs in aviremic patients, assess correlations among compartmental measurements of HIV burden, and evaluate association with clinical parameters. Design: Cross-sectional analysis of baseline data only, on 40 patients enrolled in phase 11 study evaluating efficacy of autologous gene-modified CD4+ and CD8+ T cells. All patients were on stable antiretroviral regimen with undetectable plasma HIV RNA (< 50 copies/ml). Methods: Measurements repeatedly performed over 8-12 weeks pre-intervention: blood HIV DNA, analysis of rectal mucosa-associated lymphoid tissue for both HIV RNA and HIV DNA, and quantitative co-culture of HIV from CD8-depleted peripheral blood mononuclear cells (PBMC). Results: Quantifiable levels of HIV detected in compartments despite undetectable levels of plasma HIV RNA: HIV co-culture of PBMC (88%), blood HIV DNA (95%), rectal biopsy HIV DNA (95%), rectal biopsy HIV RNA (65%). A significant correlation existed among various measures of HIV burden (HIV co-culture, blood HIV DNA, rectal biopsy HIV RNA and DNA) but not between assays and clinical parameters [duration of highly active antiretroviral therapy (HAART), type of HAART]. All assays had comparable or less variability than in plasma viral load assays; HIV co-culture had the highest coefficient of variability whereas the blood HIV DNA assay had the lowest and was considered the most reliable assay. Conclusions: The data support safety, feasibility and high compliance of quantifying reservoirs of residual HIV in treated subjects with undetectable plasma HIV RNA. Lack of correlation between levels of HIV in residual reservoirs and duration of HAART suggests treatment-mediated viral suppression alone does not lead to reproducible decay in HIV reservoirs. (C) 2003 Lippincott Williams & Wilkins. C1 Univ Calif Los Angeles, AIDS Inst, Los Angeles, CA 90095 USA. San Francisco Gen Hosp, San Francisco, CA 94110 USA. Massachusetts Gen Hosp, Boston, MA 02114 USA. ViRx Inc, San Francisco, CA USA. Adv Res Associates, Mt View, CA USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif San Diego, San Diego, CA 92103 USA. Roche Mol Syst, Alameda, CA USA. Cell Genesys Inc, Foster City, CA USA. RP Anton, PA (reprint author), Univ Calif Los Angeles, AIDS Inst, MRL 2734,675 Charles E Young Dr S, Los Angeles, CA 90095 USA. FU NCRR NIH HHS [5-MO1-RR00083-37, RR-00051, RR-00865]; NIAID NIH HHS [AI28697, AI01610] NR 25 TC 55 Z9 56 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0269-9370 J9 AIDS JI Aids PD JAN 3 PY 2003 VL 17 IS 1 BP 53 EP 63 DI 10.1097/00002030-200301030-00008 PG 11 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 634YF UT WOS:000180369500008 PM 12478069 ER PT J AU Gritti, F Piatkowski, W Guiochon, G AF Gritti, F Piatkowski, W Guiochon, G TI Study of the mass transfer kinetics in a monolithic column SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE mass transfer; kinetic studies; monolithic columns; adsorption isotherms; perturbation chromatography; frontal analysis; BET model; column efficiency; axial dispersion; mathematical modeling ID PERFORMANCE LIQUID-CHROMATOGRAPHY; POROUS SILICA COLUMNS; FINITE-ELEMENTS; IDEAL MODEL; SEPARATION; SPECTROMETRY; PROFILES; ISOTHERM; MEDIA; SPEED AB The purpose of this work is to investigate the mass transfer kinetics of butylbenzoate on a monolithic RPLC column, with methanol-water (65:35, v/v) as the mobile phase. We used the perturbation method, measuring the height equivalent to a theoretical plate (HETP) of the peaks obtained. as the response to small pulses of solute injected on a concentration plateau. The equilibrium isotherm of butylbenzoate was previously determined by frontal analysis. It is well accounted for by a liquid-solid extended multilayer BET isotherm model. The equilibrium data derived from the pulse method are in excellent 3 agreement with those of frontal analysis in the accessible concentration range of 0 to 8 g/dm(3). Plots of the HETP of small pulses, injected on eight different plateau concentrations, were acquired in a wide range of mobile phase flow velocities. The axial dispersion and the mass transfer kinetic coefficients were derived from these data. The validity of these measurements is discussed. The mass kinetics of butylbenzoate depends strongly on the plateau concentration. Processes involving adsorptive interactions between the solute and the stationary phase, e.g. surface diffusion and adsorption-desorption kinetics, combine in series to the external mass transfer kinetics and to effective pore diffusivity. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, 552 Buehler Hall, Knoxville, TN 37996 USA. NR 46 TC 74 Z9 79 U1 3 U2 13 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 3 PY 2003 VL 983 IS 1-2 BP 51 EP 71 AR PII S0021-9673(02)01648-5 DI 10.1016/S0021-9673(02)01648-5 PG 21 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 633XF UT WOS:000180309500005 PM 12568370 ER PT J AU Santer, BD Sausen, R Wigley, TML Boyle, JS AchutaRao, K Doutriaux, C Hansen, JE Meehl, GA Roeckner, E Ruedy, R Schmidt, G Taylor, KE AF Santer, BD Sausen, R Wigley, TML Boyle, JS AchutaRao, K Doutriaux, C Hansen, JE Meehl, GA Roeckner, E Ruedy, R Schmidt, G Taylor, KE TI Behavior of tropopause height and atmospheric temperature in models, reanalyses, and observations: Decadal changes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE tropopause height; tropospheric temperatures; stratospheric temperatures; climate modeling; microwave sounding unit ID CLIMATE-CHANGE SIMULATIONS; TROPICAL TROPOPAUSE; GREENHOUSE-GAS; 20TH-CENTURY TEMPERATURE; FINGERPRINT DETECTION; THERMAL STRUCTURE; OZONE DEPLETION; AEROSOL; TRENDS; ATTRIBUTION AB We examine changes in tropopause height, a variable that has hitherto been neglected in climate change detection and attribution studies. The pressure of the lapse rate tropopause, p(LRT), is diagnosed from reanalyses and from integrations performed with coupled and uncoupled climate models. In the National Centers for Environmental Prediction (NCEP) reanalysis, global-mean p(LRT) decreases by 2.16 hPa/decade over 1979-2000, indicating an increase in the height of the tropopause. The shorter European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis has a global-mean p(LRT) trend of -1.13 hPa/decade over 1979-1993. Simulated p(LRT) trends over the past several decades are consistent with reanalysis results. Superimposed on the overall increase in tropopause height in models and reanalyses are pronounced height decreases following the eruptions of El Chichon and Pinatubo. Interpreting these p(LRT) results requires knowledge of both T(z), the initial atmospheric temperature profile, and DeltaT(z), the change in this profile in response to external forcing. T( z) has a strong latitudinal dependence, as does DeltaT( z) for forcing by well-mixed greenhouse gases and stratospheric ozone depletion. These dependencies help explain why overall tropopause height increases in reanalyses and observations are amplified toward the poles. The pronounced increases in tropopause height in the climate change integrations considered here indicate that even AGCMs with coarse vertical resolution can resolve relatively small externally forced changes in tropopause height. The simulated decadal-scale changes in p(LRT) are primarily thermally driven and are an integrated measure of the anthropogenically forced warming of the troposphere and cooling of the stratosphere. Our algorithm for estimating p(LRT) (based on a thermal definition of tropopause height) is sufficiently sensitive to resolve these large-scale changes in atmospheric thermal structure. Our results indicate that the simulated increase in tropopause height over 1979-1997 is a robust, zero-order response of the climate system to forcing by well-mixed greenhouse gases and stratospheric ozone depletion. At the global-mean level, we find agreement between the simulated decadal-scale p(LRT) changes and those estimated from reanalyses. While the agreement between simulated p(LRT) changes and those in NCEP is partly fortuitous (due to excessive stratospheric cooling in NCEP), it is also driven by real pattern similarities. Our work illustrates that changes in tropopause height may be a useful "fingerprint'' of human effects on climate and are deserving of further attention. C1 Lawrence Livermore Natl Lab, PCMDI, Livermore, CA 94550 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. Zentrum Luft & Raumfahrt, Inst Phys Atmosphere, D-82234 Wessling, Germany. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. RP Santer, BD (reprint author), Lawrence Livermore Natl Lab, PCMDI, POB 808,Mail Stop L-103, Livermore, CA 94550 USA. EM santer1@llnl.gov; robert.sausen@dlr.de; wigley@ucar.edu; boyle5@llnl.gov; achutarao1@llnl.gov; doutriaux1@llnl.gov; jhansen@giss.nasa.gov; meehl@ucar.edu; roeckner@dkrz.de; cdrar@ipcc2.giss.nasa.gov; gschmidt@giss.nasa.gov; taylor13@llnl.gov RI Wigley, Tom/B-4705-2008; Taylor, Karl/F-7290-2011; Santer, Benjamin/F-9781-2011; Schmidt, Gavin/D-4427-2012 OI Taylor, Karl/0000-0002-6491-2135; Schmidt, Gavin/0000-0002-2258-0486 NR 65 TC 97 Z9 108 U1 2 U2 21 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 3 PY 2003 VL 108 IS D1 AR 4002 DI 10.1029/2002JD002258 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 654LN UT WOS:000181498500002 ER PT J AU Cheng, CZ AF Cheng, CZ TI MHD field line resonances and global modes in three-dimensional magnetic fields SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE field line resonance; MHD theory; Alfven waves; slow modes; magnetosphere; high beta plasma ID AXISYMMETRIC TOROIDAL PLASMAS; SHEAR-ALFVEN; MAGNETOSPHERIC EQUILIBRIUM; WAVES; PULSATIONS; FREQUENCY; PRESSURE; PERIODS AB [1] By assuming a general isotropic pressure distribution P = P(psi, alpha), where psi and alpha are three-dimensional scalar functions labeling the field lines with B = delpsi x delalpha, we have derived a set of MHD eigenmode equations for both global MHD modes and field line resonances (FLR). Past MHD theories are restricted to isotropic pressures with P = P(psi) only. The present formulation also allows the plasma mass density to vary along the field line. The linearized ideal MHD equations are cast into a set of global differential equations from which the field line resonance equations of the shear Alfven waves and slow magnetosonic modes are naturally obtained for general three-dimensional magnetic field geometries with flux surfaces. Several new terms associated with partial derivativeP/partial derivativealpha a are obtained. In the FLR equations a new term is found in the shear Alfven FLR equation due to the geodesic curvature and the pressure gradient in the poloidal flux surface. The coupling between the shear Alfven waves and the magnetosonic waves is through the combined effects of geodesic magnetic field curvature (k(s) =2K . B x delpsi/B-2) and plasma pressure as previously derived. The properties of the FLR eigenfunctions at the resonance field lines are investigated, and the behavior of the FLR wave solutions near the FLR surface are derived. Numerical solutions of the FLR equations for three-dimensional magnetospheric fields in equilibrium with high plasma pressure will be presented in a future publication. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Cheng, CZ (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Cheng, Chio/K-1005-2014 NR 30 TC 12 Z9 12 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 3 PY 2003 VL 108 IS A1 AR 1002 DI 10.1029/2002JA009470 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 654NQ UT WOS:000181503300004 ER PT J AU Cheng, CZ Zaharia, S AF Cheng, CZ Zaharia, S TI Field line resonances in quiet and disturbed time three-dimensional magnetospheres SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE field line resonances; magnetosphere; waves ID PC 3-4 PULSATIONS; MAGNETIC-FIELD; ALFVEN WAVES; ULF WAVES; EARTHS MAGNETOSPHERE; AURORAL ARCS; SOLAR-WIND; MODEL; EQUILIBRIUM; FREQUENCY AB [1] Numerical solutions for field line resonances (FLRs) in the magnetosphere are presented for three-dimensional equilibrium magnetic fields represented by two Euler potentials as B = delpsi x delalpha, where psi is the poloidal flux and alpha is a toroidal angle-like variable. The linearized ideal MHD equations for FLR harmonics of shear Alfven waves and slow magnetosonic modes are solved for plasmas with the pressure assumed to be isotropic and constant along a field line. The coupling between the shear Alfven waves and the slow magnetosonic waves is via the combined effects of geodesic magnetic field curvature and plasma pressure. Numerical solutions of the FLR equations are obtained for a quiet time magnetosphere as well as a disturbed time magnetosphere with a thin current sheet in the near-Earth region. The FLR frequency spectra in the equatorial plane as well as in the auroral latitude are presented. The field line length, magnetic field intensity, plasma beta, geodesic curvature, and pressure gradient in the poloidal flux surface are important in determining the FLR frequencies. In general, the computed shear Alfven FLR frequency based on the full MHD model is larger than that based on the commonly adopted cold plasma model in the beta(eq) > 1 region. For the quiet time magnetosphere, the shear Alfven resonance frequency decreases monotonically with the equatorial field line distance, which reasonably explains the harmonically structured continuous spectrum of the azimuthal magnetic field oscillations as a function of the dipole L shell in the L less than or equal to 8.8 R-E region. However, the FLR frequency spectrum for the disturbed time magnetosphere with a near-Earth thin current sheet is substantially different from that for the quiet time magnetosphere for R >6 R-E, mainly due to shorter field line length due to magnetic field compression by solar wind, reduced magnetic field intensity in the high beta current sheet region, azimuthal pressure gradient and geodesic magnetic field curvature. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Cheng, CZ (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Cheng, Chio/K-1005-2014 NR 36 TC 10 Z9 10 U1 0 U2 5 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 3 PY 2003 VL 108 IS A1 AR 1001 DI 10.1029/2002JA009471 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 654NQ UT WOS:000181503300005 ER PT J AU Tulk, CA Benmore, CJ Klug, DD Urquidi, J Neuefeind, J Tomberli, B AF Tulk, CA Benmore, CJ Klug, DD Urquidi, J Neuefeind, J Tomberli, B TI Another look at water and ice - Response SO SCIENCE LA English DT Letter C1 Oak Ridge Natl Lab, Oak Ridge, TN 37381 USA. Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada. Univ Guelph, Guelph, ON N1G 2W1, Canada. Argonne Natl Lab, Argonne, IL 60439 USA. RP Tulk, CA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37381 USA. RI Neuefeind, Joerg/D-9990-2015; Tulk, Chris/R-6088-2016 OI Neuefeind, Joerg/0000-0002-0563-1544; Tulk, Chris/0000-0003-3400-3878 NR 0 TC 1 Z9 1 U1 0 U2 4 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 3 PY 2003 VL 299 IS 5603 BP 45 EP 45 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 631JZ UT WOS:000180165800017 ER PT J AU Wang, YY Ono, S Onose, Y Gu, G Ando, Y Tokura, Y Uchida, S Ong, NP AF Wang, YY Ono, S Onose, Y Gu, G Ando, Y Tokura, Y Uchida, S Ong, NP TI Dependence of upper critical field and pairing strength on doping in cuprates SO SCIENCE LA English DT Article ID HIGH MAGNETIC-FIELDS; TRANSPORT-PROPERTIES; SUPERCONDUCTORS; TEMPERATURE; DENSITY; STATE; FILMS; TC AB We have determined the upper critical field H-c2 as a function of hole concentration in bismuth-based cuprates by measuring the voltage induced by vortex flow in a driving temperature gradient (the Nernst effect), in magnetic fields up to 45 tesla. We found that H-c2 decreased steeply as doping increased, in both single and bilayer cuprates. This relationship implies that the Cooper pairing potential displays a trend opposite to that of the superfluid density versus doping. The coherence length of the pairs xi(0) closely tracks the gap measured by photoemission. We discuss implications for understanding the doping dependence of the critical temperature T-c0. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Elect Power Ind, Cent Res Inst, Tokyo 2018511, Japan. Japan Sci & Technol, Spin Superstruct Project, Tsukuba, Ibaraki 3058562, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Sch Frontier Sci, Tokyo 1138656, Japan. Univ Tokyo, Dept Appl Phys, Tokyo 1138656, Japan. RP Ong, NP (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RI Onose, Yoshinori/F-1977-2010; Tokura, Yoshinori/C-7352-2009; Ando, Yoichi/B-8163-2013 OI Ando, Yoichi/0000-0002-3553-3355 NR 22 TC 148 Z9 152 U1 7 U2 31 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 3 PY 2003 VL 299 IS 5603 BP 86 EP 89 DI 10.1126/science.1078422 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 631JZ UT WOS:000180165800037 PM 12511645 ER PT J AU Stone, JO Balco, GA Sugden, DE Caffee, MW Sass, LC Cowdery, SG Siddoway, C AF Stone, JO Balco, GA Sugden, DE Caffee, MW Sass, LC Cowdery, SG Siddoway, C TI Holocene deglaciation of Marie Byrd Land, West Antarctica SO SCIENCE LA English DT Article ID LAST GLACIAL MAXIMUM; SEA-LEVEL CHANGE; ICE-SHEET; PAST; EARTH AB Surface exposure ages of glacial deposits in the Ford Ranges of western Marie Byrd Land indicate continuous thinning of the West Antarctic Ice Sheet by more than 700 meters near the coast throughout the past 10,000 years. Deglaciation lagged the disappearance of ice sheets in the Northern Hemisphere by thousands of years and may still be under way. These results provide further evidence that parts of the West Antarctic Ice Sheet are on a long-term trajectory of decline. West Antarctic melting contributed water to the oceans in the late Holocene and may continue to do so in the future. C1 Univ Washington, Quaternary Res Ctr, Seattle, WA 98195 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Univ Edinburgh, Dept Geog, Edinburgh EH8 9XP, Midlothian, Scotland. L397 Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Colorado Coll, Dept Geol, Colorado Springs, CO 80903 USA. RP Stone, JO (reprint author), Univ Washington, Quaternary Res Ctr, Box 351360, Seattle, WA 98195 USA. RI Caffee, Marc/K-7025-2015; OI Caffee, Marc/0000-0002-6846-8967; Siddoway, Christine Smith/0000-0003-0478-6138 NR 33 TC 137 Z9 141 U1 3 U2 27 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 3 PY 2003 VL 299 IS 5603 BP 99 EP 102 DI 10.1126/science.1077998 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 631JZ UT WOS:000180165800041 PM 12511648 ER PT J AU Yang, KL Yiacoumi, S Tsouris, C AF Yang, KL Yiacoumi, S Tsouris, C TI Electrosorption capacitance of nanostructured carbon aerogel obtained by cyclic voltammetry SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE cyclic voltammetry; electrical double layer; electrosorption; point of zero charge; carbon aerogel ID ELECTRICAL DOUBLE-LAYER; GRAPHITE-ELECTRODES; AQUEOUS-SOLUTIONS; IONS; DEIONIZATION AB Cyclic voltammetry experiments at various electrolyte solution concentrations (0.001-0.1 M) and scan rates (I to 5 mV s(-1)) have been performed to study the electrical double layer (edl) formation in nanostructured carbon aerogel. The results show that carbon aerogel is a good edl capacitor and can be further divided into mesoporous and microporous capacitors. According to the experiments, the mesoporous capacitor shows a fast charging/discharging response and is only minimally affected by the electrolyte concentration and scan rate. Therefore, the specific capacitance of the mesoporous capacitor is found to be constant over a wide range of applied electrical potentials. On the other hand, the microporous capacitor shows a slow charging/discharging response and its capacitance strongly depends on the electrolyte concentration and potential. Unlike previous experiments, in which only a flat minimum was observed at the point of zero charge (pzc), in the current study, a deep minimum is observed near the pzc at low electrolyte concentration if a slow scan rate is used. This unique feature is a result of edl overlapping in the micropores and is consistent with the predictions by the Gouy-Chapman model employed in this study. Based on this behavior, a new approach is suggested for pzc measurements of solid porous materials for which a large portion of the surface area is in the micropore region. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Georgia Inst Technol, Sch Civil & Environm Engn, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Yiacoumi, S (reprint author), Georgia Inst Technol, Sch Civil & Environm Engn, 200 Bobby Dodd Way, Atlanta, GA 30332 USA. RI Yang, Kun-Lin/C-2247-2011; Tsouris, Costas/C-2544-2016 OI Yang, Kun-Lin/0000-0002-7958-9334; Tsouris, Costas/0000-0002-0522-1027 NR 32 TC 79 Z9 85 U1 3 U2 32 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD JAN 2 PY 2003 VL 540 BP 159 EP 167 AR PII S0022-0728(02)01308-6 DI 10.1016/S0022-0728(02)01308-6 PG 9 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 642ZG UT WOS:000180836800020 ER PT J AU Evans, GB Furneaux, RH Gainsford, GJ Hanson, JC Kicska, GA Sauve, AA Schramm, VL Tyler, PC AF Evans, GB Furneaux, RH Gainsford, GJ Hanson, JC Kicska, GA Sauve, AA Schramm, VL Tyler, PC TI 8-aza-immucillins as transition-state analogue inhibitors of purine nucleoside phosphorylase and nucleoside hydrolases SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID 2.0 ANGSTROM STRUCTURE; N-RIBOSIDE HYDROLASES; C-NUCLEOSIDE; MYCOBACTERIUM-TUBERCULOSIS; CINE-SUBSTITUTION; AMP NUCLEOSIDASE; IMMUCILLIN-H; FORMYCIN; PHOSPHORIBOSYLTRANSFERASE; 1,4-DINITROPYRAZOLES AB The 8-aza-immucillins (8-aza-9-deazapurines linked from C9 to C1 of 1,4-dideoxy-1,4-iminoribitol) have been designed as transition-state analogues of the reactions catalyzed by purine nucleoside phosphorylase and nucleoside hydrolases. Syntheses of the 8-aza-immucillin analogues of inosine and adenosine are described. They are powerful inhibitors of the target enzymes with equilibrium dissociation constants as low as 42 pM. C1 Ind Res Ltd, Carbohydrate Chem, Lower Hutt, New Zealand. Yeshiva Univ Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Evans, GB (reprint author), Ind Res Ltd, Carbohydrate Chem, POB 31-310, Lower Hutt, New Zealand. EM g.evans@irl.cri.nz RI Hanson, jonathan/E-3517-2010; Evans, Gary/B-8343-2011; Furneaux, Richard/B-4157-2015 OI Evans, Gary/0000-0002-6973-2002; Furneaux, Richard/0000-0003-0973-2606 FU NIGMS NIH HHS [GM41916] NR 34 TC 48 Z9 48 U1 1 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 2 PY 2003 VL 46 IS 1 BP 155 EP 160 DI 10.1021/jm0203332 PG 6 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA 631WP UT WOS:000180190400018 PM 12502369 ER PT J AU Sergueeva, AV Song, C Valiev, RZ Mukherjee, AK AF Sergueeva, AV Song, C Valiev, RZ Mukherjee, AK TI Structure and properties of amorphous and nanocrystalline NiTi prepared by severe plastic deformation and annealing SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE nitinol; high pressure torsion; nanocrystallization; mechanical behavior ID ALLOY; NI3AL AB The formation of homogeneous nanocrystalline structure by nanocrystallization of amorphous NiTi subjected to high pressure torsion is demonstrated. Structural evolution during annealing was investigated and homogeneous nanocrystalline structures with different grain sizes have been obtained by controlled annealing. Nanocrystallization results in the record value of room temperature strength for this material equal to 2650 MPa with an elongation to failure of about 5%. At elevated temperatures of (0.4...0.5) T-m nanocrystalline nitinol showed a high ultimate strength with sufficient elongation (up to 200%). The observation that the shape and the size of grains after deformation remain close to that of the initial state suggests that in nanocrystalline NiTi such mechanism as grain boundary sliding and grain rotation are active and the generation and motion of dislocations play the role of accommodation of stress concentration. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia. RP Mukherjee, AK (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. NR 20 TC 186 Z9 190 U1 6 U2 39 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 2 PY 2003 VL 339 IS 1-2 BP 159 EP 165 AR PII S0921-5093(02)00122-3 DI 10.1016/S0921-5093(02)00122-3 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 614WX UT WOS:000179215400020 ER PT J AU Huang, JY Zhu, YT Liao, XZ Beyerlein, IJ Bourke, MA Mitchell, TE AF Huang, JY Zhu, YT Liao, XZ Beyerlein, IJ Bourke, MA Mitchell, TE TI Microstructure of cryogenic treated M2 tool steel SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE cryogenic treatment; steel; microstructure; carbide; wear resistance AB Cryogenic treatment has been claimed to improve wear resistance of certain steels and has been implemented in cutting tools, autos, barrels etc. Although it has been confirmed that cryogenic treatment can improve the service life of tools, the underling mechanism remains unclear. In this paper, we studied the microstructure changes of M2 tool steel before and after cryogenic treatment. We found that cryogenic treatment can facilitate the formation of carbon clustering and increase the carbide density in the subsequent heat treatment, thus improving the wear resistance of steels. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Huang, JY (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MS G 755, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Liao, Xiaozhou/B-3168-2009; Huang, Jianyu/C-5183-2008; Beyerlein, Irene/A-4676-2011 OI Zhu, Yuntian/0000-0002-5961-7422; Liao, Xiaozhou/0000-0001-8565-1758; NR 7 TC 128 Z9 140 U1 5 U2 22 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 2 PY 2003 VL 339 IS 1-2 BP 241 EP 244 AR PII S0921-5093(02)00165-X DI 10.1016/S0921-5093(02)00165-X PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 614WX UT WOS:000179215400031 ER PT J AU Soff, S Randrup, J Stocker, H Xu, N AF Soff, S Randrup, J Stocker, H Xu, N TI Effects of strong color fields on baryon dynamics SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; PLUS AU COLLISIONS; QUARK-GLUON MATTER; ROOT-S(NN)=130 GEV; RAPIDITY DEPENDENCE; AU+AU COLLISIONS; STOPPING POWER; PB COLLISIONS; MODEL AB We calculate the antibaryon-to-baryon ratios, (p) over bar /p, (&ULambda;) over bar/Lambda, (&UXi;) over bar/Xi, and (&UOmega;) over bar/Omega for Au + Au collisions at RHIC (rootS(NN) = 200 GeV). The effects of strong color fields associated with an enhanced strangeness and diquark production probability and with an effective decrease of formation times are investigated. Antibaryon-to-baryon ratios increase with the color field strength. The ratios also increase with the strangeness content \S\. The netbaryon number at midrapidity considerably increases with the color field strength while the netproton number remains roughly the same. This shows that the enhanced baryon transport involves a conversion into the hyperon sector (hyperonization) which can be observed in the (Lambda - (&ULambda;) over bar)/(p - (p) over bar) ratio. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Nucl Sci Div 70 319, Berkeley, CA 94720 USA. Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. RP Soff, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Nucl Sci Div 70 319, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 57 TC 21 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 2 PY 2003 VL 551 IS 1-2 BP 115 EP 120 AR PII S0370-2693(02)03019-8 DI 10.1016/S0370-2693(02)03019-8 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JE UT WOS:000180278700016 ER PT J AU Kane, GL Lykken, J Nelson, BD Wang, LT AF Kane, GL Lykken, J Nelson, BD Wang, LT TI Re-examination of electroweak symmetry breaking in supersymmetry and implications for light superpartners SO PHYSICS LETTERS B LA English DT Article ID FINE-TUNING PRICE; SOFT TERMS; MU-PROBLEM; GAUGINO CONDENSATION; NATURAL SOLUTION; HIDDEN SECTOR; STRING MODELS; UPPER-BOUNDS; SUPERGRAVITY; SCALE AB We examine arguments that could avoid light superpartners as an implication of supersymmetric radiative electroweak symmetry breaking. We argue that, from the point of view of string theory and standard approaches to generating the mu term, cancellations among parameters are not a generic feature. While the coefficients relating M-Z to parameters in the soft supersymmetry breaking Lagrangian can be made smaller, these same mechanisms lead to lighter superpartner masses at the electroweak scale. Consequently we strengthen the implication that gluinos, neutralmos, and charginos are light and likely to be produced at the Fermilab Tevatron and a linear collider. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Michigan, Randall Lab Phys, Michigan Ctr Theoret Phys, Ann Arbor, MI 48109 USA. Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Kane, GL (reprint author), Univ Michigan, Randall Lab Phys, Michigan Ctr Theoret Phys, Ann Arbor, MI 48109 USA. NR 45 TC 58 Z9 58 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 2 PY 2003 VL 551 IS 1-2 BP 146 EP 160 AR PII S0370-2693(02)03010-1 DI 10.1016/S0370-2693(02)03010-1 PG 15 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 633JE UT WOS:000180278700020 ER PT B AU Thulasidasan, S Feng, WC Gardner, MK AF Thulasidasan, S Feng, WC Gardner, MK GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Optimizing GridFTP through dynamic right-sizing SO 12TH IEEE INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 12th IEEE International Symposium on High-Performance Distributed Computing CY JUN 22-24, 2003 CL SEATTLE, WA SP IEEE Comp Soc Tech Comm Distributed Comp, Univ Arizona, Argonne Natl Lab, Univ Calif San Diego, San Diego Supercomp Ctr DE GridFTP; Globus; dynamic right-sizing; DRS; drsFTP; computational grid; bandwidth-delay product; auto-tuning AB In this paper, we describe the integration of dynamic right-sizing-an automatic and scalable buffer management technique for enhancing TCP performance-into GridFTP, a subsystem of the Globus Toolkit for managing bulk data transfers across computational grids. Such grids are often characterized by networks with large bandwidth-delay products. Unfortunately, many of today's grid applications use only a small fraction of available bandwidth because the default buffer sizes in TCP are tuned for yesterday's WAN speeds. Buffer sizes can be manually tuned to allow TCP flow control to adapt to high-speed WAN environments, but this is a tedious process. Although recent work has shown how to automatically tune system buffers during connection set-up, these values may not be appropriate for the connection's lifetime due to varying network delay and throughput. We show how using the technique of dynamic right-sizing (DRS) in GridFTP helps us optimize memory usage while maintaining high throughput over the lifetime of the connection. We also show how DRS enhances important GridFTP features such as striped and third-party data transfers in a scalable way. The technique is implemented entirely in user space so that end users do not have to modify the kernel. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Thulasidasan, S (reprint author), Los Alamos Natl Lab, CCS-5, Los Alamos, NM 87544 USA. NR 17 TC 6 Z9 6 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 0-7695-1965-2 PY 2003 BP 14 EP 23 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BX12L UT WOS:000184334900002 ER PT B AU Kleban, SD Clearwater, SH AF Kleban, SD Clearwater, SH GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Quelling queue storms SO 12TH IEEE INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 12th IEEE International Symposium on High-Performance Distributed Computing CY JUN 22-24, 2003 CL SEATTLE, WA SP IEEE Comp Soc Tech Comm Distributed Comp, Univ Arizona, Argonne Natl Lab, Univ Calif San Diego, San Diego Supercomp Ctr ID DEPENDENCE; VIDEO AB This paper characterizes "queue storms" in supercomputer systems and discusses methods for quelling them Queue storms are anomalously large queue lengths dependent upon the job size mix, the queuing system, the machine size, and correlations and dependencies between job submissions. We use synthetic data generated from actual job log data from the ASCI Blue Mountain supercomputer combined with different long-range dependencies. We show the distribution of times from the first storm to occur, which is in a sense the time when the machine becomes obsolete because it represents the time when the machine first fails to provide satisfactory turnaround. To overcome queue storms, more resources are needed even if they appear superfluous most of the time. We present two methods, including a grid-based solution, for reducing these correlations and their resulting effect on the size and frequency of queue storms. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kleban, SD (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 21 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 0-7695-1965-2 PY 2003 BP 162 EP 171 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BX12L UT WOS:000184334900015 ER PT S AU Barnum, H Saks, M Szegedy, M AF Barnum, H Saks, M Szegedy, M GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Quantum query complexity and semi-definite programming SO 18TH IEEE ANNUAL CONFERENCE ON COMPUTATIONAL COMPLEXITY, PROCEEDINGS SE IEEE Conference on Computational Complexity LA English DT Proceedings Paper CT 18th IEEE Annual Conference on Computational Complexity CY JUL 07-10, 2003 CL AARHUS, DENMARK SP IEEE Comp Soc Tech Comm Math Fdn Comp, ACM SIGACT, EATCS AB We reformulate quantum query complexity in terms of inequalities and equations for a set of positive semidefinite matrices. Using the new formulation we: 1. show that the workspace of a quantum computer can be limited to at most n + k qubits (where n and k are the number of input and output bits respectively) without reducing the computational power of the model. 2. give an algorithm that on input the truth table of a partial boolean function and an integer t runs in time polynomial in the size of the truth table and estimates, to any desired accuracy, the minimum probability of error that can be attained by a quantum query algorithm attempts to evaluate of in t queries. 3. use semidefinite programming duality to formulate a dual SDP (P) over cap (f, t, epsilon) that is feasible if and only if f can not be evaluated within error c by a t-step quantum query algorithm Using this SDP we derive a general lower bound for quantum query complexity that encompasses a lower bound method of Ambainis and its generalizations. 4. Give an interpretation of a generalized form of branching in quantum computation. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, CCS-3,MS B256, Los Alamos, NM 87545 USA. EM barnum@lanl.gov; saks@math.rutgers.edu; szegedys@cs.rutgers.edu NR 20 TC 44 Z9 44 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 SN 1093-0159 BN 0-7695-1879-6 J9 ANN IEEE CONF COMPUT PY 2003 BP 179 EP 193 DI 10.1109/CCC.2003.1214419 PG 15 WC Computer Science, Theory & Methods SC Computer Science GA BX21A UT WOS:000184613900014 ER PT B AU DiMasi, E Fossum, JO da Silva, GJ AF DiMasi, E Fossum, JO da Silva, GJ BE Dominguez, E Mas, GR Cravero, F TI Synchrotron x-ray study of hydration dynamics in the synthetic swelling clay Na-fluorohectorite SO 2001 - A CLAY ODYSSEY LA English DT Proceedings Paper CT 12th International Clay Conference CY JUL 22-28, 2001 CL UNIV NACL SUR, BAHIA BLANCA, ARGENTINA SP Assoc Int Etude Argiles, Clay Mineral Soc HO UNIV NACL SUR ID VERMICULITE; WATER; DIFFRACTION AB We present time-resolved synchrotron x-ray diffraction from the swelling clay Na fluorohectorite during controlled hydration and dehydration. A comparison of bulk and surface scattering reveals that the time dependence of basal Bragg peak positions and intensities has two components, which come into play at distinct temperatures. Intercalation of water into the crystal structure commences at a temperature of about 60degreesC, on a time scale on the order of 1 hour. By contrast, percolation of water into the porous medium has a characteristic time constant of 3-4 h. This is the rate limiting process for hydration of the interior of the clay for T>40degreesC. We suggest that the temperature-dependent percolation step may account for some of the hysteresis reported in earlier diffraction studies of the hydration of similar systems. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP DiMasi, E (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 14 TC 0 Z9 0 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-50945-3 PY 2003 BP 427 EP 434 DI 10.1016/B978-044450945-1/50144-5 PG 8 WC Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Geology; Mineralogy; Agriculture GA BX69H UT WOS:000186143000055 ER PT S AU De Geronimo, G O'Connor, P Beuttenmuller, RH Li, Z Kuczewski, AJ Siddons, DP AF De Geronimo, G O'Connor, P Beuttenmuller, RH Li, Z Kuczewski, AJ Siddons, DP BE Metzler, S TI Development of a high-rate, high-resolution detector for EXAFS experiments SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID READOUT ASICS AB A new detector for EXAFS experiments is being developed. It is based on a multi-element Si sensor and dedicated readout ASICs. The sensor is composed of 384 pixels, each having 1mm(2) area, arranged in four quadrants of 12 x 8 elements, and wire-bonded to 32-channel front-end ASICs. Each channel implements low noise preamplification with self-adaptive continuous reset, high order shaper, band-gap referenced baseline stabilizer, one threshold comparator and two DAC adjustable window comparators, each followed by a 24-bit counter. Fabricated in 0.35mum CMOS dissipates about 8mW per channel. First measurements show at room temperature a resolution of 14 rms electrons without the detector and of 40 rms electrons (340eV) with the detector connected and biased. Cooling at -35C a FWHM of 205eV (167eV from electronics) was measured at the Mn-Kalpha line. A resolution of about 300eV was measured for rates approaching 100kcps/cm(2) per channel, corresponding to an overall rate in excess of 10MHz/cm(2). A channel-to-channel threshold dispersion after DACs adjustment of 2.5 rms electrons was also measured. 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 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 19 EP 23 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500008 ER PT S AU Dombeck, TW AF Dombeck, TW BE Metzler, S TI A water calorimeter based on radiation-induced conductivity SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID ABSORPTION SPECTRA; IRRADIATED WATER; ELECTRON-BEAMS; DOSIMETRY; CALIBRATION; EQUIVALENT AB A calorimeter is described that measures the delivered dosage of radiation by the induced electrical conductivity in water through the production of long-lived ions. The device is being developed for use in providing real-time measurements of beam losses in particle accelerators. It promises to be a simple, reliable and accurate device with a linear response from a few Grays up to a MegaGray with potential application in industry and medical clinics. A model of the physical processes that produce the long-lived ions is presented in this paper and compared with the existing data. These ions have been implicated in the radiation lethality to living cells such that the water calorimeter might measure direct biological-equivalent dosage without recourse to intermediate protocols. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Dombeck, TW (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. 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 SN 1082-3654 BN 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 38 EP 42 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500012 ER PT S AU Cardona, J Kewisch, J Peggs, S AF Cardona, J Kewisch, J Peggs, S BE Metzler, S TI Optical design of the rapid cycling medical synchrotron SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc DE FODO; optics; synchrotron; protons AB The optical design of the. Rapid Cycling Medical Synchrotron (RCMS) is based on the strong focusing principle. Several advantages arise from this choice of design, including smaller beam sizes and more optimization possibilities. In this paper, a detail description of the optical design of all beam lines of the facility is presented with the methods that have been used to optimize such beam lines. Comparisons between old designs and the most recent design will be presented to illustrate the progress in the methods that have been developed for optimization. Special emphasis is made on cost savings when comparing one design with another. C1 BNL, Upton, NY USA. RP Cardona, J (reprint author), BNL, Upton, NY 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 52 EP 56 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500015 ER PT S AU Hahn, S Elphic, R Murphy, T Hodgson, M Byrd, R Longmire, J Lawrence, D Barraclough, B Fuller, K Prettyman, T Meier, M Dors, E Funsten, H Belian, R Patrick, D Latino, J Moore, T Sweet, M Burczyk, L Sutton, J Williford, R Clanton, C AF Hahn, S Elphic, R Murphy, T Hodgson, M Byrd, R Longmire, J Lawrence, D Barraclough, B Fuller, K Prettyman, T Meier, M Dors, E Funsten, H Belian, R Patrick, D Latino, J Moore, T Sweet, M Burczyk, L Sutton, J Williford, R Clanton, C BE Metzler, S TI A validation payload for space and atmospheric nuclear event detection SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc DE nuclear measurements; nuclear explosions; gamma-ray detectors; particle measurements AB We describe an experimental flight validation payload for detecting atmospheric and space nuclear events with a planned launch date in 2004. The five detector subsystems in the payload employ 27 sensors including Si, CdZnTe, gas proportional counter tubes, photomultiplier tubes, channel electron multipliers and photodiodes. Detection of events is based on simultaneous measurements of gamma rays, neutrons, and charged particles with wide dynamic ranges of deposited energy and count rates. The sensors and electronics are housed in one package with approximate mass and power consumption of 27 kg and 50 watts, respectively. The instrument uses sophisticated on-board digital signal processing and multi-layer triggering algorithms to detect and assess the validity of small signals in a large background radiation environment. This paper presents system configuration and preliminary test data from the first of the two units in development. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hahn, S (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Funsten, Herbert/A-5702-2015; Lawrence, David/E-7463-2015 OI Funsten, Herbert/0000-0002-6817-1039; Lawrence, David/0000-0002-7696-6667 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 71 EP 77 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500019 ER PT S AU Ericson, MN Britton, CL Rochelle, JM Blalock, BJ Binkley, DM Wintenberg, AL Williamson, BD AF Ericson, MN Britton, CL Rochelle, JM Blalock, BJ Binkley, DM Wintenberg, AL Williamson, BD BE Metzler, S TI Noise Behavior of MOSFETs fabricated in 0.5 mu m fully-depleted (FD) Silicon-on-Sapphire (SOS) CMOS in weak, moderate, and strong inversion SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB This paper presents a summary of the measured noise behavior of CMOS MOSFETs fabricated in a 0.5mum fully-depleted (FD) silicon-on-sapphire (SOS) process. SOS CMOS technology provides an alternative to standard bulk CMOS processes for high-density detector front-end electronics due to its inherent radiation tolerance. In this paper, the noise behavior of SOS devices will be presented and discussed with reference to device inversion coefficient (IC). The concept of inversion coefficient will be introduced and the results of SOS device noise measurements in weak, moderate, and strong inversion will be presented and compared for devices with gate lengths of 0.5mum to 4mum. Details of the noise measurement system will be provided including specifies of the measurement approach and custom circuits used for device biasing. This work will provide a thorough presentation of measured SOS device noise as a function of inversion coefficient. In addition, strategies for device biasing and sizing to obtain optimum noise performance will be presented encouraging more widespread use of SOS integrated circuits in high-density detector applications. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ericson, MN (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 125 EP 129 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500030 ER PT S AU Barbosa, FJ Jastrzembski, E Proffitt, J Wilson, J AF Barbosa, FJ Jastrzembski, E Proffitt, J Wilson, J BE Metzler, S TI The jefferson lab high resolution TDC module SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB We discuss the design of a high resolution TDC module for use in nuclear physics experiments at Jefferson Lab. Preliminary results on the performance of the prototype module are presented. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Barbosa, FJ (reprint author), Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 135 EP 139 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500032 ER PT S AU Shaw, TM Baumbaugh, A Boubekeur, A Elias, JE Hoff, J Holm, S Los, S Rivetta, C Ronzhin, A Whitmore, J Zimmerman, T Yarema, RJ AF Shaw, TM Baumbaugh, A Boubekeur, A Elias, JE Hoff, J Holm, S Los, S Rivetta, C Ronzhin, A Whitmore, J Zimmerman, T Yarema, RJ BE Metzler, S TI Front end readout electronics for the CMS Hadron Calorimeter SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB The front-end electronics for the CMS Hadron Calorimeter provides digitized data at the beam interaction rate of 40 MHz, Analog signals provided by hybrid photodiodes (HPDs) or photomultiplier tubes (PMTs) are digitized and the data is sent off board through serialized fiber optic links running at 1600 Mbps. In order to maximize the input signal, the front-end electronics are housed on the detector in close proximity to the scintillating fibers or phototubes. To fit the electronics into available space, custom crates, backplanes and cooling methods have had to be developed. During the expected ten-year lifetime, the front-end readout electronics will exist in an environment where radiation levels approach 330 rads and the neutron fluence will be 1.3E11 n/cm(2). For this reason, the design approach relies heavily upon custom radiation tolerant ASICs. This paper will present the system architecture of the front-end readout crates and describe our results with early prototypes. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Shaw, TM (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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 194 EP 197 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500045 ER PT S AU Rapisarda, SM Wilcer, NG Olsen, JT AF Rapisarda, SM Wilcer, NG Olsen, JT BE Metzler, S TI Real-time data reorganizer for the D0 Central Fiber Tracker trigger system at Fermilab SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB A custom digital data Mixer system has been designed to reorganize, in real time, the data produced by the Fermilab D0 Scintillating Fiber Detector. The data is used for the Level I and Level 2 trigger generation. The Mixer System receives the data from the front-end digitization electronics over 320 Low Voltage Differential Signaling (LVDS) links running at 371 MHz. The input data is de-serialized down to 53 MHz by the LVDS receivers, clock/frame re-synchronized and multiplexed in Field Programmable Gate Arrays (FPGAs). The data is then re-serialized at 371 MHz by LVDS transmitters over 320 LVDS output links and sent to the electronics responsible for Level I and Level 2 trigger decisions. The Mixer System processes 311 Gigabits per second of data with an input to output delay of 200 nanoseconds. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Rapisarda, SM (reprint author), Fermilab Natl Accelerator Lab, 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 203 EP 206 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500047 ER PT S AU McKenna, M Vigneault, M Adams, M Banik, A Barbknecht, L Baumbaugh, A Baumbaugh, B Beiber, C Broughton, D Brewer, P Brown, J Budd, H Cashbaugh, J Castle, L Chorny, J de Barbaro, P De la Cova, J Dwyer, D Evers, A Foltz, R Freeman, J Gromski, M Heering, A Higgins, J Kapetanovic, K Karmgard, D Lawson, J Los, S Mallen, E Marchant, J Martin, E McCamish, E Nebel, T Novak, J Nowicki, A Pagels, A Parisi, B Preuss, F Ronzhin, A Ruchti, R Ruggiero, D Skup, E Tanner, E Vanderkam, D Wiand, D Winters, T AF McKenna, M Vigneault, M Adams, M Banik, A Barbknecht, L Baumbaugh, A Baumbaugh, B Beiber, C Broughton, D Brewer, P Brown, J Budd, H Cashbaugh, J Castle, L Chorny, J de Barbaro, P De la Cova, J Dwyer, D Evers, A Foltz, R Freeman, J Gromski, M Heering, A Higgins, J Kapetanovic, K Karmgard, D Lawson, J Los, S Mallen, E Marchant, J Martin, E McCamish, E Nebel, T Novak, J Nowicki, A Pagels, A Parisi, B Preuss, F Ronzhin, A Ruchti, R Ruggiero, D Skup, E Tanner, E Vanderkam, D Wiand, D Winters, T BE Metzler, S TI Production of optical decoder units for the CMS Hadron Calorimeter SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB The CMS Hadron Calorimeter (HCAL) will use Optical Decoder Units (ODU) as a link between scintillating plastic tiles, arranged in megatile layers around the HCAL, and multi-channel hybrid photodiodes. See figure 1. Photons are produced in the scintillating tiles as sub-atomic particles pass through and deposit energy. Y-11 waveshifting fiber and cables of clear optical fiber serve as connecting transmission tines from scintillating tiles to the ODU. The ODU reorganizes tight signals from layer geometry to tower geometry for particle energy measurement. The hybrid photodiode (HPD) converts the light signals to electrical signals that are amplified and digitized for the data acquisition system. This paper provides aspects of the production of Optical Decoder Units. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP McKenna, M (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 225 EP 228 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500052 ER PT S AU Holm, S Shaw, TM Elias, J Surgueev, S AF Holm, S Shaw, TM Elias, J Surgueev, S BE Metzler, S TI Design and testing of a radiation tolerant Clock, Control and Monitor (CCM) module for the CMS HCAL electronics SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB A Clock, Control and Monitoring (CCM) Module is being designed for the Hadron Calorimeter subsystem of the CMS Detector. The CMS detector has been designed to detect cleanly the diverse signatures of new physics at the Large Hadron Collider. This CCM module will be responsible for low skew clock and beam crossing marker distribution, monitoring of voltages and temperatures and as the interface between the main control system and the Front End Modules. The CCM module will reside in the HCAL Readout Box that will be mounted on the HCAL detector. Due to this physical location the CCM module will need to work within a radiation environment with minimal access over a ten-year period. The electronics are expected to see a total neutron fluence of 1.3 x 10(11) n/cm(2) and a total ionizing dose of 330 rads over the 10 year running period. This paper will detail the design of the CCM Module including the selecting and testing of devices that will operate within the radiation field. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Holm, S (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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 229 EP 232 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500053 ER PT S AU Matis, HS Bieser, F Kleinfelder, S Rai, G Retiere, F Ritter, HG Singh, K Wurzel, SE Wieman, H Yamamoto, E AF Matis, HS Bieser, F Kleinfelder, S Rai, G Retiere, F Ritter, HG Singh, K Wurzel, SE Wieman, H Yamamoto, E BE Metzler, S TI A CMOS active pixel sensor for charged particle detection SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID TRACKING AB Active Pixel Sensor (APS) technology has shown promise for next-generation vertex detectors. This paper discusses the design and testing of two generations of APS chips. Both are arrays of 128 by 128 pixels, each 20 by 20 mum. Each array is divided into sub-arrays in which different sensor structures (4 in the first version and 16 in the second) and/or readout circuits are employed. Measurements of several of these structures under Fe-55 exposure are reported. The sensors have also been irradiated by 55 MeV protons to test for radiation damage. The radiation increased the noise and reduced the signal. The noise can be explained by shot noise from the increased leakage current and the reduction in signal is due to charge being trapped in the epi layer. Nevertheless, the radiation effect is small for the expected exposures at RHIC and RHIC II. Finally, we describe our concept for mechanically supporting a thin silicon wafer in an actual detector. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Matis, HS (reprint author), Lawrence Berkeley Lab, 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 259 EP 263 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500060 ER PT S AU Yu, B Radeka, V Smith, GC Woody, CL Smirnoff, NN AF Yu, B Radeka, V Smith, GC Woody, CL Smirnoff, NN BE Metzler, S TI Study of GEM characteristics for application in a MicroTPC SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID GAS ELECTRON MULTIPLIER; AMPLIFICATION; READOUT; CHAMBER; MWPC AB The Gas Electron Multiplier (GEM) may provide a convenient method for obtaining significant electron multiplication over large detector areas. An important potential application of the GEM is for readout of microTPCs. We are conducting a study of a multi-GEM structure with particular emphasis on the following characteristics: gain uniformity/stability, ion feedback and position readout. In particular, we present the first experimental results of interpolating anode pad readout. Initial results provide encouragement that the GEM application in microTPCs may be realized. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Yu, B (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 10 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 287 EP 291 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500066 ER PT S AU O'Connor, P De Geronimo, G Kandasamy, A AF O'Connor, P De Geronimo, G Kandasamy, A BE Metzler, S TI Amplitude and time measurement ASIC with analog derandomization SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID SILICON STRIP DETECTORS; LOW-NOISE; READOUT; SYSTEM AB We describe a new ASIC for accurate and efficient processing of high-rate pulse signals from highly segmented detectors. In contrast to conventional approaches, this circuit affords a dramatic reduction in data volume through the use of analog techniques (precision peak detectors and time-to-amplitude converters) together with fast arbitration and sequencing logic to concentrate the data before digitization. In operation the circuit functions like a data-driven analog first-in, first-out (FIFO) memory between the preamplifiers and the ADC. Peak amplitudes of pulses arriving at any one of the 32 inputs are sampled, stored, and queued for readout and digitization through a single output port. Hit timing, pulse risetime, and channel address are also available at the output. Prototype chips have been fabricated in 0.35 micron CMOS and tested. First results indicate proper functionality for pulses down to 30 ns peaking time and input rates up to 1.6 MHz/channel. Amplitude accuracy of the peak detect and hold circuit is 0.3% (absolute). TAC accuracy is within 0.3% of full scale. Power consumption is less than 2 mW/channel. Compared with conventional techniques such as track-and-hold and analog memory, this new ASIC will enable efficient pulse height measurement at 20 to 300 times higher rates. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP O'Connor, P (reprint author), Brookhaven Natl Lab, Instrumentat Div, Bldg 535B, Upton, NY 11973 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 327 EP 331 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500074 ER PT S AU Kim, JG Dardin, SM Kadel, RW Kadyk, JA Jackson, KH Peskov, V Wenzel, WA Joo, KS AF Kim, JG Dardin, SM Kadel, RW Kadyk, JA Jackson, KH Peskov, V Wenzel, WA Joo, KS BE Metzler, S TI Further studies of electron avalanche gain in liquid argon SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID XENON; EMISSION; FIELD AB Previously [1] we showed how small admixtures of xenon (Xe) stabilize electron avalanches in liquid Argon (LAr). We have measured the positive charge carrier mobility in LAr with small admixtures of Xe to be 7.0 x 10(-3) cm(2)/Vsec, in approximate agreement with the mobility measured in pure LAr, and consistent with holes as charge carriers. We have measured the concentration of Xe actually dissolved in the liquid and compared the results with expectations based on the amount of Xe gas added to the LAr. We also have tested LAr doped with krypton to investigate the mechanism of avalanche stabilization. C1 Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. RP Kim, JG (reprint author), Lawrence Berkeley Natl Lab, Div Phys, 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 SN 1082-3654 BN 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 557 EP 561 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500123 ER PT S AU Jagadish, U Britton, CL Bryan, WL Garber, FW Walter, J AF Jagadish, U Britton, CL Bryan, WL Garber, FW Walter, J BE Metzler, S TI A front-end ASIC for use with large-pixel array detectors SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID MULTIPLICITY VERTEX DETECTOR; PHENIX AB An Integrated Circuit (IC) readout chip with four channels arranged so as to receive input charge from the corners of the chip was designed for use with 5- to 7-mm pixel detectors. This Application Specific IC (ASIC) can be used for cold neutron imaging, for study of structural order in materials using cold neutron scattering or for particle physics experiments. The ASIC is fabricated in a 0.5-mum n-well AMI process. The design of the ASIC and the test measurements made will be reported. Noise measurements will also be reported. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jagadish, U (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 576 EP 579 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500127 ER PT S AU Yamada, R Hansen, S Kiper, T Lofgren, J Regan, T Smith, RP Boero, G AF Yamada, R Hansen, S Kiper, T Lofgren, J Regan, T Smith, RP Boero, G BE Metzler, S TI The DO solenoid NMR magnetometer SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB A field monitoring system for the 2 Tesla Solenoid of the D0 detector is described. It is comprised of a very small NMR probe cabled to a DSP based signal processing board. The design magnetic field range is from 1.0 to 2.2 Tesla, corresponding to an RF frequency range of 42.57 to 93.67 MHz. The desired accuracy is one part in 10(5). To minimize material in the interaction region of the D0 detector, the overall thickness of the NMR probe is 4 mm, including its mounting plate, and its width is 10 mm. To minimize cable mass, 4mm diameter IMR-100A cables are used for transmitting the RF signals from a nearby patch panel 25 meters to each of four probes mounted within the bore of the solenoid. RG213U cables 45 meters long are used to send the RF from the D0 movable counting house to the patch panel. With this setup, the detector signal voltage at the movable counting house is in the range of 250-400 mV. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Yamada, R (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 590 EP 594 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500130 ER PT S AU Coluccia, MR Appel, JA Chiodini, G Christian, DC Cihangir, S Kwan, SW Sellberg, G AF Coluccia, MR Appel, JA Chiodini, G Christian, DC Cihangir, S Kwan, SW Sellberg, G BE Metzler, S TI Electrical characterization of irradiated prototype silicon pixel sensors for BTeV SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID READOUT CHIP; RADIATION AB The pixel detector in the BTeV experiment at the Tevatron (Fermilab) provides high-resolution tracking and vertex identification. For this task the hybrid pixel detector has to work in a very harsh radiation environment with up to 10(14) minimum ionizing particles/cm(2)/year. Radiation hardness of prototype n(+)/n/p(+) silicon pixel sensors has been investigated. We present electrical characterization curves for irradiated prototype n(+)/n/p(+) sensors, intended for use in the BTeV experiment. We tested pixel sensors from various vendors and with two pixel isolation techniques: p-stop and p-spray. Results are based on irradiation with 200 MeV protons up to 6 x 10(14) protons/cm(2). C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Coluccia, MR (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 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 SN 1082-3654 BN 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 638 EP 644 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500140 ER PT S AU Shokouhi, S Stoll, SP Villanueva, A Vaska, P Schlyer, DJ Woody, CL Yu, B O'Connor, P Pratte, JF Radeka, V Volkow, N Fowler, JS AF Shokouhi, S Stoll, SP Villanueva, A Vaska, P Schlyer, DJ Woody, CL Yu, B O'Connor, P Pratte, JF Radeka, V Volkow, N Fowler, JS BE Metzler, S TI A non-invasive LSO-APD blood radioactivity monitor for PET imaging studies SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID POSITRON-EMISSION-TOMOGRAPHY; ARTERIAL INPUT FUNCTION; DETECTOR SYSTEM; METABOLIC-RATE; FLOW; FDG AB A study has been carried out to investigate the possibility of using a pair of LSO + APD detector arrays to obtain a non-invasive measurement of the arterial input function for use in PET. The main focus of this study was to determine the spatial resolution and sensitivity required to obtain a high quality image that would permit a precise determination of the region of interest around the wrist artery. From these data a quantitative arterial input function that has minimal interference from the tissue and vein background can be obtained. The detector arrays were operated in coincidence counting mode to obtain planar images of various phantoms to demonstrate the feasibility of the concept. C1 SUNY Stony Brook, Dept Biomed Engn, Stony Brook, NY 11794 USA. RP Shokouhi, S (reprint author), Brookhaven Natl Lab, Dept Chem, Bldg 901, Upton, NY 11973 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 SN 1082-3654 BN 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 921 EP 925 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500201 ER PT S AU Goddard, JS Gleason, SS Paulus, MJ Majewski, S Popov, V Smith, M Weisenberger, A Welch, B Wojcik, R AF Goddard, JS Gleason, SS Paulus, MJ Majewski, S Popov, V Smith, M Weisenberger, A Welch, B Wojcik, R BE Metzler, S TI Real-time landmark-based unrestrained animal tracking system for motion-corrected PET/SPECT imaging SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB Oak Ridge National Laboratory (ORNL) and Jefferson Lab and are collaborating to develop a new high-resolution single photon emission tomography (SPECT) instrument to image unrestrained laboratory animals. This technology development will allow functional imaging studies to be performed on the animals without the use of anesthetic agents. This technology development could have eventual clinical applications for performing functional imaging studies on patients that cannot remain still (Parkinson's patients, Alzheimer's patients, small children, etc.) during a PET or SPECT scan. A key component of this new device is the position tracking apparatus. The tracking apparatus is an integral part of the gantry and designed to measure the spatial position of the animal at a rate of 10-15 frames per second with sub-millimeter accuracy. Initial work focuses on brain studies where anesthetic agents or physical restraint can significantly impact physiologic processes. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Goddard, JS (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1534 EP 1537 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500338 ER PT S AU Reutter, BW Gullberg, GT Huesman, RH AF Reutter, BW Gullberg, GT Huesman, RH BE Metzler, S TI Accuracy and precision of compartmental model parameters obtained from directly estimated dynamic SPECT time-activity curves SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE Nuclear Science Symposium Conference Record LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc DE dynamic single photon emission computed tomography (SPECT); fully four-dimensional (4-13) reconstruction; kinetic parameter estimation ID EMISSION COMPUTED-TOMOGRAPHY; SPATIOTEMPORAL DISTRIBUTIONS; RECONSTRUCTION; PROJECTIONS AB Quantitative kinetic analysis of dynamic cardiac single photon emission computed tomography (SPECT) data has the potential to provide better contrast between healthy and diseased tissue, compared to static images. However, imaging a rapidly changing radiopharmaceutical distribution with the use of a moving gantry yields inconsistent projection data that can generate artifacts in a time sequence of conventional image reconstructions. The artifacts can lead to biases in kinetic parameters estimated from the image sequence. This source of bias can be eliminated by estimating B-spline models for time-activity curves directly from the projections. In this study, we perform Monte Carlo simulations to determine how the polynomial order and initial time sampling of the splines affect the accuracy and precision of compartmental model parameters obtained from directly estimated time-activity curves. The Mathematical Cardiac Torso (MCAT) phantom is used to simulate a realistic 15 min dynamic (99m)Tc-teboroxime patient study in which 10 million total events are detected. For a large volume of normal myocardium (250 cc), the relative bias of the uptake and washout parameter sample means does not exceed 0.22% when using cubic or quadratic splines that provide rapid initial sampling. The coefficient of variation is about 1%. For small (8.4 cc) myocardial defects that exhibit reduced uptake and accelerated washout, the relative bias and coefficient of variation increase to maximum values of about 16% and 49%, respectively. These levels of accuracy and precision allow the defects to be discriminated from the normal myocardium. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Med & Funct Imaging, Berkeley, CA 94720 USA. RP Reutter, BW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Med & Funct Imaging, Berkeley, CA 94720 USA. EM bwreutter@lbl.gov NR 16 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1584 EP 1588 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500350 ER PT S AU Vaska, P Stoll, SP Woody, CL Schlyer, DJ Shokouhi, S AF Vaska, P Stoll, SP Woody, CL Schlyer, DJ Shokouhi, S BE Metzler, S TI Effects of inter-crystal cross-talk on multi-element LSO/APD PET detectors SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID SCATTER; ARRAYS; PERFORMANCE; MODULE AB One of the most promising high resolution PET detector designs comprises an array of small, optically isolated scintillator crystals each coupled to an independent photosensor, such as an avalanche photodiode (APD). However, cross-talk between crystals (due to Compton scatter, photoelectron escape, or incomplete optical isolation) can significantly degrade performance, and is expected to increase as crystals become narrower to improve spatial resolution. Various measures of cross-talk have been determined for different configurations of 4x8 blocks of 2 mm x 2 nun lutetium oxyorthosilicate (LSO) crystals coupled to matched Hamamatsu APD arrays. Results indicate that ignoring crosstalk signals could lead to a similar to30% loss in coincidence sensitivity for a tomograph using these detectors, and a decrease in energy resolution of similar to2 percentage points. Spatial and time resolution would not be significantly affected with most practical front-end architectures. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Vaska, P (reprint author), Brookhaven Natl Lab, Upton, NY 11973 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1643 EP 1647 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500363 ER PT S AU Moses, WW AF Moses, WW BE Metzler, S TI Advantages of improved timing accuracy in PET cameras using LSO scintillator SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID POSITRON-EMISSION-TOMOGRAPHY; OF-FLIGHT MEASUREMENTS; IMAGE-RECONSTRUCTION; ACCIDENTAL COINCIDENCES; SYSTEM; INFORMATION; LUALO3-CE; ARRAYS AB PET scanners based on LSO have the potential for significantly better coincidence timing resolution than the 6 ns fwhm typically achieved with BGO. This study analyzes the performance enhancements made possible by improved timing as a function of the coincidence time resolution. If 500 ps fwhm coincidence timing resolution can be achieved in a complete PET camera, the following four benefits can be realized for whole-body FDG imaging: 1) The random event rate can be reduced by using a narrower coincidence timing window, increasing the peak NECR by similar to50%. 2) Using time-of-flight in the reconstruction algorithm will reduce the noise variance by a factor of 5. 3) Emission and transmission data can be acquired simultaneously, reducing the total scan time. 4) Axial blurring can be reduced by using time-of-flight to determine the correct axial plane that each event originated from. While time-of-flight was extensively studied in the 1980's, practical factors limited its effectiveness at that time and little attention has been paid to timing in PET since then. As these potential improvements are substantial and the advent of LSO PET cameras gives us the means to obtain them without other sacrifices, efforts to improve PET timing should resume after their long dormancy. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Moses, WW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 35 TC 0 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1670 EP 1675 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500369 ER PT S AU Qi, JY Huesman, RH AF Qi, JY Huesman, RH BE Metzler, S TI Wavelet crosstalk matrix and its application to assessment of shift-variant Imaging systems SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID RECONSTRUCTION; SVD; SPECT AB The objective assessment of image quality is essential for design of imaging systems. Barrett and Gifford [1] introduced the Fourier crosstalk matrix. Because it is diagonal for continuous linear shift-invariant imaging systems, the Fourier crosstalk matrix is a powerful technique for discrete imaging systems that are close to shift invariant. However, for a system that is intrinsically shift-variant, Fourier techniques are not particularly effective. Because Fourier bases have no localization property, the shift-variance of the imaging system cannot be shown by the response of individual Fourier bases; rather, it is shown in the correlation between the Fourier coefficients. This makes the analysis and optimization quite difficult. In this paper, we introduce a wavelet crosstalk matrix based on wavelet series expansions. The wavelet crosstalk matrix allows simultaneous study of the imaging system in both the frequency and spatial domains. Hence it is well suited for shift-variant systems. We compared the wavelet crosstalk matrix with the Fourier crosstalk matrix several simulated imaging systems, namely the interior and exterior tomography problems, limited angle tomography, and a rectangular geometry positron emission tomograph. The results demonstrate the advantages of the wavelet crosstalk matrix in analyzing shift-variant imaging systems. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Qi, JY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RI Qi, Jinyi/A-1768-2010 OI Qi, Jinyi/0000-0002-5428-0322 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1696 EP 1700 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500374 ER PT S AU Smith, MF Kieper, DA Majewski, S Weisenberger, AG Welch, B AF Smith, MF Kieper, DA Majewski, S Weisenberger, AG Welch, B BE Metzler, S TI Optimizing pinhole and parallel hole collimation for scintimammography with compact pixellated detectors SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc AB The relative advantages of pinhole and parallel hole collimators for scintimammography with compact, pixellated gamma detectors were investigated using analytic models of resolution and sensitivity. Collimator design was studied as follows. A desired object resolution was specified for a pixellated detector with a given crystal size and intrinsic spatial resolution and for a given object-to-collimator distance. Using analytic formulas, pinhole and parallel hole collimator parameters were calculated that satisfy this object resolution with optimal geometric sensitivity. Analyses were performed for 15 cm x 20 cm field of view detectors with crystal elements 1.0, 2.0 and 3.0 nun on a side and 140 keV incident photons. The sensitivity for a given object resolution was greater for pinhole collimation at smaller distances, as expected. The object distance at which the pinhole and parallel hole sensitivity curves cross each other is important. The crossover distances increased with larger crystal size for a constant object resolution and increased as the desired object resolution decreases for a constant crystal size. For example, for 4 mm object resolution these distances were 5.5 cm, 6.5 cm and 8 cm for the 1 mm, 2 mm and 3 mm crystal detectors, respectively. The results suggest a strategy of parallel hole collimation for whole breast imaging and pinhole collimation for imaging focal uptake. This could be accomplished with a dual detector system with a different collimator type on each head or a single head system equipped with two collimators and a rapid switching mechanism. Multipinhole collimators have the potential to increase sensitivity yet maintain high image resolution. An experimental SPECT phantom study with a four-pinhole collimator was acquired with a pixellated detector. The iterative maximum-likelihood expectation-maximization (MLEM) reconstruction of a hot sphere in a warm cylinder showed the potential of multipinhole collimation to improve sensitivity for tomographic pinhole scintimammography. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Smith, MF (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. NR 10 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1806 EP 1809 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500397 ER PT S AU Huesman, RH Klein, GJ Kimdon, JA Kuo, C Majumdar, S AF Huesman, RH Klein, GJ Kimdon, JA Kuo, C Majumdar, S BE Metzler, S TI Deformable registration of multi-modal data including rigid structures SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc DE multi-modality; registration; lumbar spine; rigid; elastic; x-ray; CT; MRI ID THIN-PLATE SPLINES; MUTUAL INFORMATION; IMAGE REGISTRATION; DEFORMATIONS; MAXIMIZATION; CT AB Multi-modality imaging studies are becoming more widely utilized in the analysis of medical data. Anatomical data from CT and MRI are useful for analyzing or further processing functional data from techniques such as PET and SPECT. When data are not acquired simultaneously, even when these data are acquired on a dual-imaging device using the same bed, motion can occur that requires registration between the reconstructed image volumes. As the human torso can allow non-rigid motion, this type of motion should be estimated and corrected. We report a deformation registration technique that utilizes rigid registration for bony structures, while allowing elastic transformation of soft tissue to more accurately register the entire image volume. The technique is applied to the registration of CT and MR images of the lumbar spine. First a global rigid registration is performed to approximately align features. Bony structures are then segmented from the CT data using a semi-automated process, and bounding boxes for each vertebra are established. Each CT subvolume is then individually registered to the MRI data using a piece-wise rigid registration algorithm and a mutual information image similarity measure. The resulting set of rigid transformations allows for accurate registration of the parts of the CT and MRI data representing the vertebrae, but not the adjacent soft tissue. To align the soft tissue, a smoothly-varying deformation is computed using a thin plate spline (TPS) algorithm. The TPS technique requires a sparse set of landmarks that are to be brought into correspondence. These landmarks are automatically obtained from the segmented data using simple edge-detection techniques and random sampling from the edge candidates. A smoothness parameter is also included in the TPS formulation for characterization of the stiffness of the soft tissue. Estimation of an appropriate stiffness factor is obtained iteratively by using the mutual information cost function on the result of the global deformable transformation. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Huesman, RH (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Kuo, Chaincy/H-9475-2016 OI Kuo, Chaincy/0000-0001-7958-8764 NR 8 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1879 EP 1882 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500413 ER PT S AU Smith, MF Majewski, S Raylman, RR AF Smith, MF Majewski, S Raylman, RR BE Metzler, S TI Positron emission mammography with multiple angle acquisition SO 2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY NOV 10-16, 2002 CL NORFOLK, VA SP IEEE, Nucl & Plasma Sci Soc ID IMAGING-SYSTEM; BREAST-CANCER; PET AB Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor: background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three-dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal-to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Smith, MF (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. NR 14 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 0-7803-7636-6 J9 IEEE NUCL SCI CONF R PY 2003 BP 1892 EP 1896 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BX56R UT WOS:000185702500416 ER PT B AU Ho, CK AF Ho, CK GP ASME TI Stochastic modeling of chemical transport through human skin SO 2003 ADVANCES IN BIOENGINEERING LA English DT Proceedings Paper CT ASME International Mechanical Engineering Congress CY NOV 15-21, 2003 CL Washington, DC SP ASME, Fluid Power Syst & Technol Div, ASME, Micro Elect Mech Syst Div, ASME, Fluids Engn Div, ASME, Bioengn Div, ASME, Appl Mech Div, ASME, Elect & Photon Packaging Div, ASME, Mfg Engn Div, ASME, Adv Energy Syst Div, ASME, Aerosp Div AB A probabilistic, transient, three-phase model of chemical transport through human skin has been developed to assess the relative importance of uncertain parameters and processes during chemical exposure assessments and transdermal drug delivery. Penetration routes through the skin that were modeled include the following: (1) intercellular diffusion through the multiphase stratum comeum; (2) aqueous-phase diffusion through sweat ducts; and (3) oil-phase diffusion through hair follicles. Uncertainty distributions were developed for the model parameters, and a Monte Carlo analysis was performed to simulate probability distributions of mass fluxes through each of the routes for a hypothetical scenario of chemical transport through the skin. At early times (60 seconds), the sweat ducts provided a significant amount of simulated mass flux into the bloodstream. At longer times (1 hour), diffusion through the stratum comeum became important because of its relatively large surface area. Sensitivity analyses using stepwise linear regression were also performed to identify model parameters that were most important to the simulated mass fluxes at different times. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ho, CK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-3710-6 PY 2003 BP 1 EP 3 PG 3 WC Biophysics; Engineering, Biomedical; Mechanics; Medicine, Research & Experimental SC Biophysics; Engineering; Mechanics; Research & Experimental Medicine GA BAL07 UT WOS:000222660500001 ER PT B AU Kambour, KE Hjalmarson, HP Myles, CW AF Kambour, KE Hjalmarson, HP Myles, CW GP IEEE IEEE TI Theory of optically-triggered electrical breakdown of semiconductors SO 2003 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 19-22, 2003 CL ALBUQUERQUE, NM SP IEEE Dielect & Elect Insulat Soc AB In this paper, we describe a rate equation approach that leads to new insights about electrical breakdown in insulating and semiconducting materials. In this approach, the competition between carrier generation by impact ionization and carrier recombination by Auger and defect recombination leads to steady state solutions for the carrier generation rate, and it is the accessibility of these steady state solutions, for a given electric field, that governs whether breakdown does or does not occur. This approach leads to theoretical definitions for not only the intrinsic breakdown field but also other characteristic quantities. Results obtained for GaAs using a carrier distribution function calculated by both a Maxwellian approximation and an ensemble Monte Carlo method will be discussed. C1 Texas Tech Univ, Dept Phys, Lubbock, TX 79409 USA. RP Hjalmarson, HP (reprint author), Sandia Natl Labs, MS-0316, 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 0-7803-7910-1 PY 2003 BP 345 EP 348 DI 10.1109/CEIDP.2003.1254864 PG 4 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BX92E UT WOS:000186828000083 ER PT B AU Bacon, LD Lehr, JM Molina, LL Salazar, RA AF Bacon, LD Lehr, JM Molina, LL Salazar, RA GP IEEE IEEE TI Measurement of the dielectric properties of dispersive materials over a wide frequency range SO 2003 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 19-22, 2003 CL ALBUQUERQUE, NM SP IEEE Dielect & Elect Insulat Soc ID DECONVOLUTION AB The propagation of electromagnetic waves through dispersive media forms the basis for a wide variety of applications. Rapid advances in materials have produced new products with tailored responses across frequency bands. Many of these new materials, such as radar absorbing material and photonic crystals, are dispersive in nature. This, in turn, has opened up the possibility for the exploitation of these dispersive dielectric properties for a variety of applications. Thus, it is desirable to know the electromagnetic properties of both man-made and natural materials across a wide frequency range. With the advent of transient pulsers with sub-nanosecond risetimes and rates of voltage rise approaching 10**16 V/s, the frequencies of interest in the transient response extend to approximately the 2 GHz range. Although a network analyzer can provide either frequency- or time- domain data (by inverse transform), common TEM cells are only rated to 0.5 to 1.5 GHz - significantly below the maximum frequency of interest. To extend the frequency range to include 2 GHz, a TEM cell was characterized and a de-embedding algorithm was applied to account, in part, for the limitations of the cell. The de-embedding technique is described along with such measurement issues such as clear time and sneak around. Measurements of complex permittivity of common drinking water are shown. This frequency extension will lead to more expansive testing of dielectric materials of interest. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bacon, LD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 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 0-7803-7910-1 PY 2003 BP 526 EP 529 DI 10.1109/CEIDP.2003.1254908 PG 4 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BX92E UT WOS:000186828000127 ER PT B AU Sauers, I Pace, MO James, DR Ellis, AR AF Sauers, I Pace, MO James, DR Ellis, AR GP IEEE IEEE TI Energy dissipation by partial discharge in cryogenic cables SO 2003 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 19-22, 2003 CL ALBUQUERQUE, NM SP IEEE Dielect & Elect Insulat Soc ID TEMPERATURE SUPERCONDUCTING CABLE; COMPOSITE INSULATION SYSTEM; LIQUID; INCEPTION AB In general the two contributions to aging in lapped tape insulated cables are partial discharge and thermal heating. At cryogenic temperatures, thermal aging is expected to be negligible, leaving partial discharge as the primary aging mechanism. Using data obtained with a digital partial discharge detector, the energy dissipated by PD can be determined from the product of the apparent charge of each PD pulse times the instantaneous applied voltage and summing over all pulses. This can be shown to be equivalent to the product of actual charge and the internal voltage at the site of PD. It can also be shown that the slope, n, of the log plot of energy dissipation versus voltage is the same, n, in the exponent of the power law used in aging studies. We will show data on energy dissipation versus voltage for lapped tape insulated cable in pressurized liquid nitrogen and compare the n from that data with aging data reported in the literature. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Sauers, I (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 0-7803-7910-1 PY 2003 BP 624 EP 627 DI 10.1109/CEIDP.2003.1254932 PG 4 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BX92E UT WOS:000186828000151 ER PT B AU James, DR Sauers, I Ellis, AR Pace, MO Deschenes, DJ AF James, DR Sauers, I Ellis, AR Pace, MO Deschenes, DJ GP IEEE IEEE TI Effect of gas pressure on partial discharge in voids in epoxy SO 2003 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 19-22, 2003 CL ALBUQUERQUE, NM SP IEEE Dielect & Elect Insulat Soc AB The pressure inside an enclosed void in a solid dielectric is generally determined by calculation based on equating the measured partial discharge (PD) onset voltage and the breakdown voltage from the Paschen curve for a particular gas. Here it is assumed that the gas is known or that physical properties remain approximately constant. In the present experiment, two different large voids were placed in epoxy adjacent to the ground electrode containing a small pump out port. This arrangement allowed for direct measurement and setting of the pressure for different gases filling the void. PD onset and extinction voltages were determined as a function of pressure over the range from 13.3 Pa (0.1 torr) to 101 kPa (760 torr) for nitrogen and SF6 at room temperature. The onset voltages generally followed the Paschen curve dependence on pressure but were higher in voltage at pressures around the minimum, while the extinction voltage followed the Paschen curve more closely in both pressure dependence and voltage. Agreement with the Paschen curve is better at the higher pressures. One possible explanation is the dominant role that real surfaces play at lower pressures. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP James, DR (reprint author), Oak Ridge Natl Lab, 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 0-7803-7910-1 PY 2003 BP 628 EP 632 DI 10.1109/CEIDP.2003.1254933 PG 5 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BX92E UT WOS:000186828000152 ER PT S AU Christophersen, JP Motloch, CG Ho, CD Morrison, JL Fenton, RC Battaglia, VS Duong, TQ AF Christophersen, JP Motloch, CG Ho, CD Morrison, JL Fenton, RC Battaglia, VS Duong, TQ GP IEEE TI Lumped parameter modeling as a predictive tool for a battery status monitor SO 2003 IEEE 58TH VEHICULAR TECHNOLOGY CONFERENCE, VOLS1-5, PROCEEDINGS SE IEEE VTS Vehicular Technology Conference Proceedings LA English DT Proceedings Paper CT 58th IEEE Vehicular Technology Conference (VTC 2003) CY OCT 06-09, 2003 CL Orlando, FL SP IEEE, IEEE VTS DE Advanced Technology Development; lithium-ion batteries; lumped parameter model; battery status monitor AB The Advanced Technology Development Program is currently evaluating the performance of the second generation of lithium-ion cells (i.e., Gen 2 cells). Both the Gen 2 Baseline and Variant C cells are tested in accordance with the cell-specific test plan, and are removed at roughly equal power fade increments and sent for destructive diagnostic analysis. The diagnostic laboratories did not need all test cells for analysis, and returned five spare cells to the Idaho National Engineering and Environmental Laboratory (INEEL). INEEL used these cells for special pulse testing at various duty cycles, amplitudes, and durations to investigate the usefulness of the lumped parameter model as a predictive tool in a battery status monitor. The lumped parameter model is a simplified linear model that accurately predicts the voltage response during certain pulse conditions. A database of parameter trends should enable dynamic predictions of state-of-charge and state-of-health conditions during in-vehicle pulsing. This information could be used by the battery status monitor to provide accurate information to the vehicle control system. C1 Idaho Natl Engn & Environm Lab, Transportat Technol & Infrastruct Dept, Idaho Falls, ID USA. RP Christophersen, JP (reprint author), Idaho Natl Engn & Environm Lab, Transportat Technol & Infrastruct Dept, Idaho Falls, ID USA. NR 5 TC 1 Z9 1 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1090-3038 BN 0-7803-7954-3 J9 IEEE VTS VEH TECHNOL PY 2003 BP 3257 EP 3261 DI 10.1109/VETECF.2003.1286255 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BAD40 UT WOS:000221662300658 ER PT S AU Wells, L Sorensen, K Doerry, A Remund, B AF Wells, L Sorensen, K Doerry, A Remund, B GP IEEE IEEE TI Developments in SAR and IFSAR systems and technologies at Sandia National Laboratories SO 2003 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-8 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 08-15, 2003 CL BIG SKY, MT SP IEEE Aerosp & Elect Syst Soc, Aerosp Corp, Analog Interfaces, AstroExpo com, Caltech, JPL, Circle Mt Co, Gandalf Associates, LLC, GEB Software Technologies, Missile Defense Agcy, NASA, Panasonic, SpectrumAstro, Superior Solut, TechLink AB Sandia National Laboratories is a leader in the development of airborne, real-time, fine-resolution, high image quality Synthetic Aperture Radar (SAR), high-performance Interferometric SAR (IFSAR), advanced SAR algorithms, and SAR hardware. Recently designed Sandia airborne systems are the most capable and flexible SARs and IFSARs in existence, offering unprecedented performance and image quality. Sandia designed SARs are currently operational on several platforms for a variety of users. Applications of these systems include surveillance, arms control non-proliferation and treaty verification, military and civilian intelligence, precision guidance and targeting, environmental monitoring, and other issues of interest to the Department of Energy, and the nation at large. Additionally, Sandia continues its strong tradition of research and development in even higher performance SARs, new operating modes, and extensions to basic SAR capabilities and underlying technologies. Experimental systems include; a novel US band foliage penetration SAR, a "VideoSAR" mode that creates "movie-like" images that uniquely allow monitoring of moving targets, and a radar responsive tag system. Current R&D efforts include; a new Ka band SAR capable of unprecedented ultra-fine resolutions, a 20 pound full functional SAR, and a digital radar receiver. This paper will provide a brief overview of these selected Sandia SAR development efforts. C1 Sandia Natl Labs, Radar & Signals Analy Dept, Albuquerque, NM 87185 USA. RP Wells, L (reprint author), Sandia Natl Labs, Radar & Signals Analy Dept, POB 5800 MS 0519, Albuquerque, NM 87185 USA. 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 1095-323X BN 0-7803-7651-X J9 AEROSP CONF PROC PY 2003 BP 1085 EP 1095 PG 11 WC Engineering, Aerospace SC Engineering GA BX65K UT WOS:000185997700108 ER PT S AU Barbee, TW AF Barbee, TW GP IEEE IEEE TI Nano-laminates: A new class of materials for aerospace applications SO 2003 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-8 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 08-15, 2003 CL BIG SKY, MT SP IEEE Aerosp & Elect Syst Soc, Aerosp Corp, Analog Interfaces, AstroExpo com, Caltech, JPL, Circle Mt Co, Gandalf Associates, LLC, GEB Software Technologies, Missile Defense Agcy, NASA, Panasonic, SpectrumAstro, Superior Solut, TechLink AB Nano-laminate materials are fully dense ultra-fine grained high interface concentration solids. Such materials are characterized by truly nano-microstructures. They are typically synthesized using atom-by-atom processes such as molecular beam epitaxy, thermal physical evaporation, sputter physical evaporation, chemical vapor deposition and electrochemical atom by atom based technologies. The microstructure scale of nano-laminate materials is determined during synthesis by control of the thickness of the individual layers. These layers may be from one monolayer (0.2 nm) to hundreds of monolayers (> 200 nm) thick. The macroscopic thickness of nano-laminates has, in the past, been generally limited to less than 1 squarem, and more typically, to 0.5 squarem or less. Magnetron sputter deposition of thick nano-laminate materials has been developed at LLNL and used to fabricate free standing high quality structures. Nano-laminate materials having areas up to 1600 cm(2), thickness up to 400 squarem and containing more than 50,000 individual layers have been fabricated using the LLNL magnetron approach. At this time nano-laminate structures have been synthesized from at least 78 of the 92 naturally occurring elements in elemental form, as alloys or as compounds at LLNL. These macroscopic nano-laminates enable effective property determination, facilitate traditional structural characterization approaches and have fostered the development of applications that are generative rather than incremental in impact. In this presentation the LLNL magnetron fabrication technology is discussed first. Specific emphasis will be placed on the range of materials used and the variations in structural parameters that may be fabricated. Transmission electron microscopy (TEM) observations of the structure of a copper/zirconium nano-laminates will be presented. Nano-laminate materials are now applied in several areas high lighted in the following and are under development for ther applications. These are based on their properities of: 1) exceptional mechanical performance; 2) exceptional surface quality for thick nano-laminate foils; 3) measurement of alloy/compound thermodynamic properties; 4) advanced resource conservative alloydevelopment; 5) high performance x-ray, soft x-ray and extreme ultra-violet optics: 6) energetic materials development; 7) development of very low areal density large area optic structures. Applications under active development or use are presented in TABLE1. In this presentation development of very low areal density large area optic structures will be considered. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Barbee, TW (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 14 TC 0 Z9 0 U1 3 U2 7 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7651-X J9 AEROSP CONF PROC PY 2003 BP 1745 EP 1754 PG 10 WC Engineering, Aerospace SC Engineering GA BX65K UT WOS:000185997700177 ER PT S AU Perkins, JD Teplin, CW van Hest, MFAM Harris, SR AF Perkins, JD Teplin, CW van Hest, MFAM Harris, SR GP IEEE IEEE TI Optimization of transparent conducting oxides for liquid crystal based optical phased arrays SO 2003 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-8 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 08-15, 2003 CL BIG SKY, MT SP IEEE Aerosp & Elect Syst Soc, Aerosp Corp, Analog Interfaces, AstroExpo com, Caltech, JPL, Circle Mt Co, Gandalf Associates, LLC, GEB Software Technologies, Missile Defense Agcy, NASA, Panasonic, SpectrumAstro, Superior Solut, TechLink AB Transparent conducting oxides are used as a contacting layer to liquid crystal (LC) based single wavelength optical phased array (OPA) infrared beam steerers. To investigate TCO optimization for this application, a numerical model based on the Drude (free-electron) theory is used to calculate the optical absorption at 1550 nm for layers with a fixed sheet resistance, R-S, as a function of conducting electron concentration and carrier mobility. For fixed R-S, carrier mobility is found to be the critical parameter. In short, increased mobility allows for reduced carrier concentration and hence less absorption for a given sheet resistance. For R-S = 3000 Omega/Sq., as is used in current prototype LC-OPA devices, the use of high conductivity commercial ITO would require using a very thin, similar to1 nm thick, ITO layer. However, the conventionally worse TCO Zn-Sn-O has good mobility but with a much lower carrier concentration than ITO which allows for a more robust layer thickness of 20 nm while still keeping the absorption minimal. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Perkins, JD (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 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 1095-323X BN 0-7803-7651-X J9 AEROSP CONF PROC PY 2003 BP 1823 EP 1829 PG 7 WC Engineering, Aerospace SC Engineering GA BX65K UT WOS:000185997700185 ER PT S AU Graham, P Caffrey, M Wirthlin, M Johnson, DE Rollins, N AF Graham, P Caffrey, M Wirthlin, M Johnson, DE Rollins, N GP IEEE IEEE TI Reconfigurable computing in space: From current technology to reconfigurable systems-on-a-chip SO 2003 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-8 SE IEEE Aerospace Conference Proceedings LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 08-15, 2003 CL BIG SKY, MT SP IEEE Aerosp & Elect Syst Soc, Aerosp Corp, Analog Interfaces, AstroExpo com, Caltech, JPL, Circle Mt Co, Gandalf Associates, LLC, GEB Software Technologies, Missile Defense Agcy, NASA, Panasonic, SpectrumAstro, Superior Solut, TechLink AB With the improved performance, in-system reprogrammability, flexibility, and reduced costs of using SRAM-based FPGAs in low-volume systems, FPGAs have some distinct advantages over both microprocessor and ASIC solutions in space-based computing systems. Despite these advantages, radiation-tolerant FPGAs are still susceptible to single-event upsets (SEUs) that must be managed to make these devices useful in space. This paper describes the various SEU categories for the Virtex FPGA and their observability characteristics as well as several techniques for managing the effects of these SEUs. Additionally, this paper provides several practical design considerations for systems employing Virtex FPGAs for space systems as well as a brief look at newer FPGA families and their potential for space-based reconfigurable computing. From this and previous work, we believe that some space-based systems can effectively use radiation-tolerant SRAM-based FPGAs. C1 Los Alamos Natl Lab, Space Data Syst, NIS 3, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Space Data Syst, NIS 3, Mailstop D440, Los Alamos, NM 87545 USA. EM grahamp@lanl.gov; mpc@lanl.gov; wirthlin@ee.byu.edu; dej23@ee.byu.edu; nhr2@ee.byu.edu 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 SN 1095-323X BN 0-7803-7651-X J9 AEROSP CONF PROC PY 2003 BP 2399 EP 2410 PG 12 WC Engineering, Aerospace SC Engineering GA BX65K UT WOS:000185997700237 ER PT B AU Dowla, F Spiridon, A AF Dowla, F Spiridon, A GP IEEE TI Spotforming with an array of ultra-wideband radio transmitters SO 2003 IEEE CONFERENCE ON ULTRA WIDEBAND SYSTEMS AND TECHNOLOGIES, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Conference on Ultra-Wideband Systems and Technologies CY NOV 16-19, 2003 CL RESTON, VA SP IEEE Microwave Theory & Tech Soc, VA Tech Mobile & Portable Radio Res Grp, IEEE No Va Sect, IEEE Aerosp & Elect Syst Soc, IEEE Electromagnet Compatibil Soc, IEEE Signal Proc Soc, Intel AB Ultra-wideband (UWB) array signal processing has the distinct advantage in that it is possible to illuminate or focus on "spots" at distant points in space, as opposed to just illuminating or steering at certain directions for narrowband array processing. The term "spotforming" is used to emphasize the property that point-focusing techniques with UWB waveforms can be viewed as a generalization of the well-known narrowband beamforming techniques. Because methods in spotforming can lead to powerful applications for UWB systems, in this paper we derive, simulate and experimentally verify UWB spot size as a function of frequency, bandwidth and array aperture. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Dowla, F (reprint author), Lawrence Livermore Natl Lab, L-290, Livermore, CA 94551 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 0-7803-8187-4 PY 2003 BP 172 EP 175 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BY30U UT WOS:000188866600034 ER PT B AU Mills, TD Hoskins, RS Nemier, MS AF Mills, TD Hoskins, RS Nemier, MS GP IEEE IEEE TI Application of material characterization techniques to electrical forensic analysis SO 2003 IEEE INDUSTRIAL AND COMMERCIAL POWER SYSTEMS TECHNICAL CONFERENCE, CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Industrial and Commercial Power Systems Technical Conference CY MAY 04-08, 2003 CL ST LOUIS, MO SP IEEE Ind Appl Soc, Ind & Commercial Power Syst, IEEE Reg 5, IEEE St Louis Sect DE forensics; seismic qualification; material characterization; scanning electron microscope; SEM; uninterruptible power supply; UPS AB The application of forensic science techniques to electrical equipment failure investigation has not been widely documented in the engineering world. This paper is intended to share an example of using material characterization techniques to support an initial cause determination of an electrical component "failure" event. The resulting conclusion supported the initial cause determination and ruled out the possibility of design deficiencies. Thus, the qualification testing of the equipment was allowed to continue to successful completion. C1 Bechtel Savannah River Inc, Aiken, SC 29808 USA. RP Mills, TD (reprint author), Bechtel Savannah River Inc, Savannah River Site, Aiken, SC 29808 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 0-7803-7771-0 PY 2003 BP 98 EP 104 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW75W UT WOS:000183073700014 ER PT S AU Rubinstein, F Treado, S Pettler, P AF Rubinstein, F Treado, S Pettler, P GP IEEE IEEE IEEE TI Standardizing communication between lighting control devices - A role for IEEE P1451 SO 2003 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-3: CROSSROADS TO INNOVATIONS SE IEEE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETING LA English DT Proceedings Paper CT 38th Annual Meeting of the Industry-Applications-Society CY OCT 12-16, 2003 CL SALT LAKE CITY, UT SP IEEE Ind Applicat Soc DE building equipment; lighting controls; networking; BACnet; IEEE P1451; IBECS; DALI; building controls; communication protocols AB The paper proposes a building equipment communications network based on a federation of existing standards and communications protocols. The proposed network concept provides a viable model for control manufacturers to provide advanced digital control of most building equipment. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Bldg Technol Dept, Berkeley, CA 94720 USA. RP Rubinstein, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Bldg Technol Dept, Berkeley, CA 94720 USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0197-2618 BN 0-7803-7883-0 J9 IEEE IND APPLIC SOC PY 2003 BP 805 EP 811 PG 7 WC Automation & Control Systems; Energy & Fuels; Engineering, Industrial; Engineering, Electrical & Electronic; Engineering, Mechanical SC Automation & Control Systems; Energy & Fuels; Engineering GA BY14W UT WOS:000187891400117 ER PT S AU Rao, NSV Wu, Q Iyengar, SS Manickam, A AF Rao, NSV Wu, Q Iyengar, SS Manickam, A GP IEEE IEEE TI Connectivity-through-time Protocols for dynamic wireless networks to support mobile robot teams SO 2003 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-3, PROCEEDINGS SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT 20th IEEE International Conference on Robotics and Automation (ICRA) CY SEP 14-19, 2003 CL TAIPEI, TAIWAN SP IEEE Robot & Automat Soc, Natl Sci Council, Minist Educ, Chinese Inst Automat Engineers, Ind Technol Res Inst, TECO Elect & Machinery Co Ltd, Met Ind Res & Dev Ctr AB Mobile robot teams are increasingly deployed in various applications involving remote operations in unstructured environments that do not support wireless network infrastructures. We propose a class of protocols based on the connectivity-through-time concepts that exploit the robot movements to extend the traditional notions of network connectivity. These protocols enable the formation of ad hoc networks of mobile robots without the infrastructure of access points by utilizing the robots as routers. These protocols are implemented as a collection of daemons that track connectivity changes, compute single and multiple hop connectivity, route the packets via robots with suitable buffering, and adapt the transport parameters to the connection characteristics. The implementation employs UDP with window-based flow control that is tuned to the nature of connections. We present experimental performance results based on our implementation on robot teams to illustrate the salient features of this approach. C1 Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. RP Rao, NSV (reprint author), Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. OI Rao, Nageswara/0000-0002-3408-5941 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 1050-4729 BN 0-7803-7736-2 J9 IEEE INT CONF ROBOT PY 2003 BP 1653 EP 1658 DI 10.1109/ROBOT.2003.1241831 PG 6 WC Robotics SC Robotics GA BY05H UT WOS:000187419900265 ER PT S AU Marble, JL Bruemmer, DJ Few, DA AF Marble, JL Bruemmer, DJ Few, DA GP IEEE IEEE TI Lessons learned from usability tests with a collaborative cognitive workspace for human-robot teams SO 2003 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN AND CYBERNETICS, VOLS 1-5, CONFERENCE PROCEEDINGS SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC 03) CY OCT 05-08, 2003 CL WASHINGTON, D.C. SP IEEE, Syst, Man & Cybernet Soc DE mixed-initiative control; dynamic autonomy; human-robot interaction; robots AB Use of new robotics technologies is challenged by issues of system trust, unknowns regarding how the system will, can, and should be used, and possibilities for human error that may cause harm to the human operator, system, or environment. This paper discusses initial usability tests of a mixed-initiative robotic system. Participants were asked to search a building using a robot equipped with multiple levels of autonomy to identify 3 targets in pre-specified locations. The experiment showed a significant difference between novice and experienced robotic operators especially regarding willingness to use the autonomous capabilities of the robot. Users unfamiliar with teleoperation were more willing to utilize the autonomous capabilities of the robot, while skilled teleoperators preferred and were more efficient when in direct control. Users were almost always able to successfully complete the search task. However, feedback indicates that users, having been given only a cursory explanation of the system, were sometimes confused by robot initiative even though the interface supplied textual explanations. The experiment shows that mixed-initiative interaction may exceed the limitations of either fully autonomous or teleoperated control; however, potential benefits can easily be overshadowed by control challenges inherent to deploying robot-human teams. C1 Idaho Natl Engn & Environm Lab, Human Robot & Remote Syst, Idaho Falls, ID USA. RP Marble, JL (reprint author), Idaho Natl Engn & Environm Lab, Human Robot & Remote Syst, Idaho Falls, ID USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-7952-7 J9 IEEE SYS MAN CYBERN PY 2003 BP 448 EP 453 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BX83D UT WOS:000186578600074 ER PT B AU Schmidt, DJ Pianetta, PA AF Schmidt, DJ Pianetta, PA GP IEEE IEEE TI Color filtering metallization for optoelectronic 100nm CMOS circuits SO 2003 IEEE INTERNATIONAL ELECTRON DEVICES MEETING, TECHNICAL DIGEST LA English DT Proceedings Paper CT IEEE International Electron Devices Meeting CY DEC 08-10, 2003 CL WASHINGTON, D.C. SP IEEE, Elect Devices Soc ID TRANSMISSION AB We show a novel color filter system that can be implemented in a standard CMOS process without any additional chemicals and processing, using standard CMOS metals like aluminum. The filter uses sub-wavelength aperture and grating arrays allowing some light wavelengths through while blocking others. Furthermore, we show an integrated photo-detector, both as a standard junction diode and an MSM diode which combines the filters and detector into the simplest color imaging system. The experimental data is explained with simulations and electromagnetic theory. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7872-5 PY 2003 BP 389 EP 392 PG 4 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BY39C UT WOS:000189158800089 ER PT B AU Ericson, MN Britton, CL Rochelle, JM Blalock, BJ Williamson, BD Greenwell, RL Schultz, R AF Ericson, MN Britton, CL Rochelle, JM Blalock, BJ Williamson, BD Greenwell, RL Schultz, R GP IEEE IEEE TI High temperature DC characterization of fully-depleted 0.5 mu m SOS-CMOS MOSFETs for analog circuit design SO 2003 IEEE INTERNATIONAL SOI CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT IEEE International SOI Conference CY SEP 29-OCT 02, 2003 CL NEWPORT BEACH, CA SP IEEE Elect Devices Soc AB Extensive characterization results of MOSFET small-signal parameters over temperature (25 to 300 C) are presented for low-V-T transistors fabricated in a SOS 0.5-mum process. Low-V-T devices such as these are particularly useful for low-voltage, low-power (LVLP) analog applications. Small-signal do 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 (0.5mum to 16mum) and temperature. Inversion coefficient representation is employed for data presentation and analysis. This work provides the most thorough presentation of SOS MOSFET do parameters as a function of both gate length and temperature to date. In addition, this work summarizes device information essential for successful high-temperature SOS-CMOS analog circuit design. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ericson, MN (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 BN 0-7803-7815-6 PY 2003 BP 89 EP 91 PG 3 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BX71S UT WOS:000186203600036 ER PT B AU Hansson, AA Aulin, TM AF Hansson, AA Aulin, TM GP IEEE IEEE TI Generalized APP detection for unknown ISI channels SO 2003 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Symposium on Information Theory CY JUN 29-JUL 04, 2003 CL Yokohama, JAPAN SP IEEE, IEEE Informat Theory Soc AB Soft information is computed in a simple way. In particular, we investigate iterative detection of serially concatenated continuous phase modulation corrupted by unknown intersymbol interference. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hansson, AA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS M997, 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 BN 0-7803-7728-1 PY 2003 BP 199 EP 199 PG 1 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BX68L UT WOS:000186112600199 ER PT B AU Ganti, A Klein, TE Haner, M AF Ganti, A Klein, TE Haner, M GP IEEE IEEE TI Base station assignment and power control algorithms for data users in a wireless multiaccess framework SO 2003 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Symposium on Information Theory CY JUN 29-JUL 04, 2003 CL Yokohama, JAPAN SP IEEE, IEEE Informat Theory Soc C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ganti, A (reprint author), Sandia Natl Labs, 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 BN 0-7803-7728-1 PY 2003 BP 336 EP 336 PG 1 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BX68L UT WOS:000186112600336 ER PT S AU Rosfjord, K Denham, P Kemp, C Gullikson, E Batson, P Rekawa, S Attwood, D AF Rosfjord, K Denham, P Kemp, C Gullikson, E Batson, P Rekawa, S Attwood, D GP IEEE IEEE TI Initial characterization of new coherent soft x-ray branchline at the advanced light source SO 2003 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society CY OCT 27-30, 2003 CL TUCSON, AZ SP IEEE Lasers & Electro Opt Soc C1 Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Rosfjord, K (reprint author), Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 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 SN 1092-8081 BN 0-7803-7888-1 J9 IEEE LEOS ANN MTG PY 2003 BP 160 EP 160 PG 1 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BY23D UT WOS:000188359700080 ER PT S AU Chao, W Anderson, E Denbeaux, G Harteneck, B Liddle, JA Olynick, D Pearson, AL Salmassi, F Song, C Attwood, D AF Chao, W Anderson, E Denbeaux, G Harteneck, B Liddle, JA Olynick, D Pearson, AL Salmassi, F Song, C Attwood, D GP IEEE IEEE TI New demonstration technique of 20 nm spatial resolution soft X-ray microscopy SO 2003 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society CY OCT 27-30, 2003 CL TUCSON, AZ SP IEEE Lasers & Electro Opt Soc C1 Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Chao, W (reprint author), Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RI Liddle, James/A-4867-2013 OI Liddle, James/0000-0002-2508-7910 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 0-7803-7888-1 J9 IEEE LEOS ANN MTG PY 2003 BP 225 EP 226 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BY23D UT WOS:000188359700113 ER PT S AU Williams, GP Neil, GR Douglas, DR Benson, S AF Williams, GP Neil, GR Douglas, DR Benson, S GP IEEE IEEE TI High power THz generation from relativistic electrons SO 2003 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society CY OCT 27-30, 2003 CL TUCSON, AZ SP IEEE Lasers & Electro Opt Soc ID SYNCHROTRON-RADIATION C1 Jefferson Lab, Free Electron Laser Facil, Newport News, VA 23606 USA. RP Williams, GP (reprint author), Jefferson Lab, Free Electron Laser Facil, 12000 Jefferson Ave, Newport News, VA 23606 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 0-7803-7888-1 J9 IEEE LEOS ANN MTG PY 2003 BP 324 EP 325 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BY23D UT WOS:000188359700164 ER PT S AU Cole, EI Bruce, MR Barton, DL Tangyunyong, P Bruce, VJ Hawkins, CF Soden, JM Henderson, L Ring, RM Chong, WL Eppes, DH Wilcox, J Benson, DA AF Cole, EI Bruce, MR Barton, DL Tangyunyong, P Bruce, VJ Hawkins, CF Soden, JM Henderson, L Ring, RM Chong, WL Eppes, DH Wilcox, J Benson, DA GP IEEE IEEE TI Optical tools and techniques for failure analysis of modern integrated circuits SO 2003 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society CY OCT 27-30, 2003 CL TUCSON, AZ SP IEEE Lasers & Electro Opt Soc AB Defect localization in modem ICs can be extremely challenging. To address this complexity several optically based methodologies have been developed over the past decade. These techniques will be described demonstrating their utility in locating defects. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Cole, EI (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 8 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-7888-1 J9 IEEE LEOS ANN MTG PY 2003 BP 537 EP 538 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BY23D UT WOS:000188359700271 ER PT S AU Allerman, AA Fischer, AJ Crawford, MH Lee, SR Bogart, KHA Mitchell, CC Koleske, DD Follstaedt, DM Provencio, PP Missert, NA AF Allerman, AA Fischer, AJ Crawford, MH Lee, SR Bogart, KHA Mitchell, CC Koleske, DD Follstaedt, DM Provencio, PP Missert, NA GP IEEE IEEE TI GaN to AIN: Materials for deep-UV emitters SO 2003 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 16th Annual Meeting of the IEEE Lasers and Electro-Optics Society CY OCT 27-30, 2003 CL TUCSON, AZ SP IEEE Lasers & Electro Opt Soc C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Allerman, AA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 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 SN 1092-8081 BN 0-7803-7888-1 J9 IEEE LEOS ANN MTG PY 2003 BP 874 EP 875 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BY23D UT WOS:000188359700440 ER PT B AU Cich, MJ Lopez, GM Tigges, C Spahn, OB AF Cich, MJ Lopez, GM Tigges, C Spahn, OB GP IEEE IEEE TI GaAs-based microelectromechanical waveguide switches monolithically integrated with lasers and detectors SO 2003 IEEE/LEOS INTERNATIONAL CONFERENCE ON OPTICAL MEMS LA English DT Proceedings Paper CT IEEE/LEOS International Conference on Optical MEMS CY AUG 18-21, 2003 CL WAIKOLOA, HI SP IEEE, LEOS C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cich, MJ (reprint author), Sandia Natl Labs, MS0603, 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 0-7803-7830-X PY 2003 BP 137 EP 138 DI 10.1109/OMEMS.2003.1233504 PG 2 WC Optics SC Optics GA BX51V UT WOS:000185581900066 ER PT B AU Nekoogar, F Dowla, F AF Nekoogar, F Dowla, F BE Gebali, F TI Performance of multiple pulse multiple delay modulated UWB signals in a multiple access indoor wireless channel SO 2003 IEEE PACIFIC RIM CONFERENCE ON COMMUNICATIONS, COMPUTERS, AND SIGNAL PROCESSING, VOLS 1 AND 2, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Pacific Rim Conference on Communications Computers and Signal Processing (PACRIM 2003) CY AUG 28-30, 2003 CL VICTORIA, CANADA SP IEEE Canada Reg 7, IEEE Victoria Sect, Univ Victoria ID PROPAGATION; RADIO AB In this paper, the performance of a two user UWB multiple access (UWB-MA) system based on multiple-pulse multiple-delay (MPMD) modulation scheme in an indoor wireless channel is evaluated by computer simulations. The indoor multipath propagation channel model used in this study is based on the modified statistical Saleh-Valenzuela model proposed by Foerester and Li from Intel. The simulation results indicate that the multipath performance of MPMD modulated signals in a multiple access system outperforms the non-multipath case as the number of autocorrelation function (ACF) sampling points increases for each user. This is an unusual but important result, since MPMD receiver exploits multipath phenomenon in indoor wireless channels to increase the BER performance, hence the transmission rate in a UWB-MA system. C1 Univ Calif Davis, Univ Calif Lawrence Livermore Natl Lab, Dept Appl Sci, Davis, CA 95616 USA. RP Nekoogar, F (reprint author), Univ Calif Davis, Univ Calif Lawrence Livermore Natl Lab, Dept Appl Sci, Davis, CA 95616 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 0-7803-7978-0 PY 2003 BP 545 EP 548 PG 4 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Telecommunications SC Computer Science; Engineering; Imaging Science & Photographic Technology; Telecommunications GA BX78G UT WOS:000186424200134 ER PT B AU Basso, TS DeBlasio, RD AF Basso, TS DeBlasio, RD GP IEEE TI IEEE P1547-series of standards for interconnection SO 2003 IEEE PES TRANSMISSION AND DISTRIBUTION CONFERENCE & EXPOSITION, VOLS 1-3, CONFERENCE PROCEEDINGS: BLAZING TRAILS IN ENERGY DELIVERY AND SERVICES LA English DT Proceedings Paper CT IEEE PES Transmission and Distribution Conference and Exposition CY SEP 07-12, 2003 CL Dallas, TX SP IEEE Power Engn soc DE certification; communications; distributed generation; distributed power; distributed resources; dispersed storagem and generation; fuel cells; interconnection; monitoring and control; power systems; photovoltaic power systems; power distribution; power generation; regulation; standards; test AB The IEEE P1547 Standard For Interconnecting Distributed Resources With Electric Power Systems is the first in the P1547-series of planned interconnection standards, and, there are additional standards needed. There are major issues and obstacles to an orderly transition to using and integrating distributed power resources with electric power systems (grid or utility grid). The lack of uniform national interconnection standards and tests for interconnection operation and certification, as well as the lack of uniform national building, electrical, and safety codes, are understood, and, resolving that needs reasonable lead time to develop and promulgate consensus. The P1547 standard is a benchmark milestone for the IEEE standards consensus process and successfully demonstrates a model for ongoing success in developing further national standards and for moving forward in modernizing our nation's electric power system. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Basso, TS (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 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 0-7803-8110-6 PY 2003 BP 556 EP 561 DI 10.1109/TDC.2003.1335335 PG 6 WC Energy & Fuels SC Energy & Fuels GA BY41E UT WOS:000189196900101 ER PT B AU Guttromson, RT Chassin, DP Widergren, SE AF Guttromson, RT Chassin, DP Widergren, SE GP IEEE IEEE TI Residential energy resource models for distribution feeder simulation SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc DE adaptive systems; complexity theory; home appliances; load modeling; power distribution; power system simulation AB Advances in information technology, ubiquitous communications, and distributed generation and storage reveal new opportunities for the participation of demand-side resources in balancing the physical and economic operation of electric power systems. To better understand the potential impact of this participation, accurate, detailed energy resource models are necessary at the distribution feeder level. This presentation describes a detailed approach to residential energy resource modeling that preserves the individual characteristics of major residential appliances and human behavior patterns so that their contribution to energy efficiency schemes and intelligent demand curtailment algorithms is properly portrayed. These models are derived from previous analyses of residential and commercial building systems supported by data collected from the End-Use Load and Consumer Assessment Program (ELCAP) undertaken by the Bonneville Power Administration from 1983 to 1990. Preliminary results of using these models in distribution system simulations indicate that non-obvious, complex behavior patterns can emerge when consumers are confronted with varying price signals. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Guttromson, RT (reprint author), Pacific NW Natl Lab, POB 999,MSIN,K5-20, Richland, WA 99352 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 BN 0-7803-7989-6 PY 2003 BP 108 EP 113 DI 10.1109/PES.2003.1267145 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300037 ER PT B AU Corey, GP AF Corey, GP GP IEEE IEEE TI Batteries for stationary standby and for stationary cycling applications - Introduction SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc DE batteries; battery storage plants; energy storage; emergency power supplies; standards AB The term "Stationary Battery" tends to conjure up many interpretations among power engineers, depending on one's perspectives on battery energy storage. The primary application that immediately comes to mind is that for standby or UPS use, but that is not the only application for stationary batteries. Currently, changes are underway where large stationary batteries are being used in grid-tied cycling applications for Distributed Energy Resource systems. The current IEEE standards developed for standby application do not apply to these new stationary applications, but many engineers are totally unaware of the not-so-subtle differences in standby battery and cycling battery O&M requirements. The purpose of this paper is to introduce engineers who will be using stationary batteries in cycling applications to the differences in-battery system management standards currently in use in the IEEE to preclude the improper application of standards for standby applications with those intended for cycling applications. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Corey, GP (reprint author), Sandia Natl Labs, POB 5800,MS-0710, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7989-6 PY 2003 BP 139 EP 140 DI 10.1109/PES.2003.1267154 PG 2 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300046 ER PT B AU Chamberlin, JL AF Chamberlin, JL GP IEEE IEEE TI Batteries for stationary standby and cycling applications Part 5: Maintenance and testing standards SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc DE batteries; maintenance; testing; IEEE standards AB The existing IEEE stationary battery maintenance and testing standards fall into two basic categories: those associated with grid-tied standby applications and those associated with stand-alone photovoltaic cycling applications. These applications differ in several significant ways which in turn influence their associated standards. A review of the factors influencing the maintenance and testing of stationary battery systems provides the reasons for the differences between these standards and some of the hazards of using a standard inappropriate to the application. This review also provides a background on why these standards will need to be supplemented in the future to support emerging requirements of other applications, such as grid-tied cycling and photovoltaic hybrid applications. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chamberlin, JL (reprint author), Sandia Natl Labs, POB 5800,MS-0665, Albuquerque, NM 87185 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 BN 0-7803-7989-6 PY 2003 BP 158 EP 163 DI 10.1109/PES.2003.1267159 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300051 ER PT B AU Koritarov, VS Veselka, TD AF Koritarov, VS Veselka, TD GP IEEE IEEE TI Modeling the regional electricity network in southeast Europe SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc DE regional electricity market; interconnections; power transactions; locational marginal prices AB The objective of this analysis is to investigate the potential benefits of a regional electricity market in Southeast Europe in 2005. The study models the operation of electric power systems of seven countries. The primary software tool is the GTMax model, which was used to analyze the operation of individual utility systems, as well as their operation in a regional electricity market. Four typical weeks in different seasons of 2005 are simulated. To capture the variability of hydro inflows and their influence on hydro generation, the analysis is performed for three hydrological conditions: wet, average, and dry. In the analysis of regional electricity market scenario, GTMax is used to calculate hourly values of locational marginal prices for all nodes of the regional network and to optimize power transactions among the utility systems. A comparison of operating costs obtained for the two scenarios showed that regional electricity market provides for significant benefits and cost savings compared to the operation of individual utility systems. Substantial costs savings are achieved in all analyzed periods and under all hydrological conditions. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Koritarov, VS (reprint author), Argonne Natl Lab, 9700 S Cass Ave,DIS-900, Argonne, IL 60439 USA. 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 0-7803-7989-6 PY 2003 BP 399 EP 404 DI 10.1109/PES.2003.1267208 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300104 ER PT B AU Lesieutre, BC Thomas, RJ Mount, TD AF Lesieutre, BC Thomas, RJ Mount, TD GP IEEE IEEE TI A revenue sensitivity approach for the identification and quantification of market power in electric energy markets SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc DE deregulation; electric energy markets; market power AB In this paper we present a practical approach for identifying and measuring market power in an electric energy market. To do so we determine which participants or groups of participants have the ability to increase their own revenues without affecting. the rest of the market, and then apply a relative measure to quantify the extent of market power exploitation. We present a 30-bus, 6-generator example in which two generators in a load pocket are found to have and use market power. Using price and revenue signals from a repeated auction, we explain how these generators learn to exploit their power over time. Experimental results are also presented and analyzed. C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Lesieutre, BC (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 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 0-7803-7989-6 PY 2003 BP 838 EP 842 DI 10.1109/PES.2003.1270416 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300196 ER PT B AU Herig, C AF Herig, C GP IEEE IEEE TI Photovoltaics as a distributed resource - Making the value connection SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Herig, C (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 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 0-7803-7989-6 PY 2003 BP 1334 EP 1338 DI 10.1109/PES.2003.1268445 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300305 ER PT B AU Guttromson, RT AF Guttromson, RT GP IEEE IEEE TI Modeling distributed energy resource dynamics on the transmission system SO 2003 IEEE POWER ENGINEERING SOCIETY GENERAL MEETING, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE-Power-Engineering-Society General Meeting CY JUL 13-17, 2003 CL TORONTO, CANADA SP IEEE Power Engn Soc DE distributed generation; distributed energy resources; transient stability; small signal stability; dynamic performance C1 Pacific NW Natl Lab, Richland, WA USA. RP Guttromson, RT (reprint author), Pacific NW Natl Lab, Richland, WA 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 0-7803-7989-6 PY 2003 BP 2146 EP 2146 DI 10.1109/PES.2003.1270947 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BY07E UT WOS:000187500300472 ER PT B AU Brocato, R Heller, E Wendt, J Gurule, E Omdahl, G Gibson, C Smith, J Palmer, D AF Brocato, R Heller, E Wendt, J Gurule, E Omdahl, G Gibson, C Smith, J Palmer, D GP ieee TI Ultra-wideband communication using a SAW correlator Zero-IF architecture SO 2003 IEEE TOPICAL CONFERENCE ON WIRELESS COMMUNICATION TECHNOLOGY LA English DT Proceedings Paper CT IEEE Topical Conference on Wireless Communication Technology/2nd Wireless Grantees Workshop CY OCT 15-17, 2003 CL Honolulu, HI SP IEEE, IEICE, Natl Sci Fdn AB A communication system has been demonstrated using surface acoustic wave (SAW) correlators in a direct conversion, ultra-wideband architecture. High frequency SAW correlators were used to passively detect a BPSK input signal and provide a direct RF-to-baseband conversion. SAW correlators were used to build transmitters and receivers with 3.3 %, 12.5%, 25%, and 50% fractional bandwidths centered at 900 MHz and 2.45 GHz. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Brocato, R (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 0-7803-8196-3 PY 2003 BP 443 EP 444 PG 2 WC Telecommunications SC Telecommunications GA BAL36 UT WOS:000222673800184 ER PT S AU Telschow, KL Larson, JD AF Telschow, KL Larson, JD BE Yuhas, DE Schneider, SC TI Determination of lateral mode dispersion from full-field imaging of film bulk acoustic resonator motion SO 2003 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1 AND 2 SE ULTRASONICS SYMPOSIUM LA English DT Proceedings Paper CT IEEE International Ultrasonics Symposium CY OCT 05-08, 2003 CL Honolulu, HI SP IEEE Ultrason, Ferroelect & Frequency Control Soc ID WAVES AB A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates and heterodyne principles are used to allow operation at any frequency from Hz to GHz. Both acoustic amplitude and phase are recorded allowing Fourier transformation of the displacement images to provide a mapping of excited mode wavenumbers at each frequency. Measurements as a function of frequency provide a means for mode identification and a direct measure of the lateral mode dispersion. Results are presented at frequencies near the first longitudinal plate thickness mode (similar to 876 MHz) demonstrating simultaneous excitation of lateral modes with nonzero wavenumbers in an electrically driven AlN thin film bulk acoustic resonator. Discussion and analysis are presented illustrating identification of specific lateral modes and illustration of the effects of physical dimensions and material elastic properties on the measured dispersion relations. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Telschow, KL (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1051-0117 BN 0-7803-7922-5 J9 ULTRASON PY 2003 BP 280 EP 283 PG 4 WC Acoustics; Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Engineering; Radiology, Nuclear Medicine & Medical Imaging GA BY90R UT WOS:000189492100062 ER PT B AU Cheung, SCS Zakhor, A AF Cheung, SCS Zakhor, A GP IEEE IEEE TI Fast similarity search on video signatures SO 2003 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOL 2, PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Image Processing CY SEP 14-17, 2003 CL BARCELONA, SPAIN SP IEEE Signal Proc Soc AB Video signatures are compact representations of video sequences designed for efficient similarity measurement. In this paper we propose a feature extraction technique to support fast similarity search on large databases of video signatures. Our proposed technique transforms the high dimensional video signatures into low dimensional vectors where similarity search can be efficiently performed. We exploit both the upper and lower bounds of the triangle inequalities in approximating the high-dimensional metric, and combine this approximation with the classical PCA to achieve the target dimension. Experimental results on a large set of web video sequences show that our technique outperforms Fastmap, Haar wavelet, PCA, and Triangle-Inequality Pruning. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Cheung, SCS (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-561, Livermore, CA 94551 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 0-7803-7750-8 PY 2003 BP 1 EP 4 PG 4 WC Computer Science, Artificial Intelligence; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BX96F UT WOS:000187010300001 ER PT B AU Johnstone, CJ Berz, M Errede, D Makino, K AF Johnstone, CJ Berz, M Errede, D Makino, K GP IEEE IEEE TI Optimization and beam control in large-emittance accelerators: Neutrino Factories SO 2003 INTERNATIONAL CONFERENCE PHYSICS AND CONTROL, VOLS 1-4, PROCEEDINGS: VOL 1: PHYSICS AND CONTROL: GENERAL PROBLEMS AND APPLICATIONS; VOL 2: CONTROL OF OSCILLATIONS AND CHAOS; VOL 3: CONTROL OF MICROWORLD PROCESSES. NANO- AND FEMTOTECHNOLOGIES; VOL 4: NONLINEAR DYNAMICS AND CONTROL LA English DT Proceedings Paper CT International Conference on Physics and Control (PHYSCON 2003) CY AUG 20-22, 2003 CL ST PETERSBURG, RUSSIA SP Russian Acad Sci, St Petersburg Sci Ctr, St Petersburg Grp Russian Natl Comm Automat Control, St Petersburg Informat & Control Soc, Russian Acad Sci, Inst Problem Mech Engn, St Petersburg State Univ, European Phys Soc, Int Union Theoret & Appl Mech, IEEE Control Syst Soc, IEEE Circuits & Syst Soc, Russia N IEEE Sect, Russia W IEEE Sect, EPS Interdivis Grp Expt Phys Control Syst, Cent Sci & Res Inst, City Univ Hong KOng AB Schemes for intense sources of high-energy muons require collection, rf capture, and transport of particle beams with unprecedented emittances, both longitudinally and transversely. These large emittances Must be reduced or "cooled" both in size and in energy spread before the muons can be efficiently accelerated. Therefore, formation of muon beams sufficiently intense to drive a Neutrino Factory or Muon Collider requires multi-stage preparation. Further, because of the large beam phase space which must be successfully controlled, accelerated, and transported, the major stages that comprise such a facility: proton driver, production, capture, phase rotation, cooling, acceleration, and storage are complex and strongly interlinked. Each of the stages must be consecutively matched and simultaneously optimized with upstream and downstream systems, meeting challenges not only technically in the optics and component design, but also in the modeling of both new and extended components. One design for transverse cooling, for example, employs meter-diameter solenoids to maintain strong focusing-300-500 mr beam divergences-across ultralarge momentum ranges, greater than or equal to 20% deltap/p, defying conventional approximations to the dynamics and field representation. To now, the interplay of the different systems and staging strategies has not been formally addressed. This work discusses two basic, but different approaches to a Neutrino Factory and how the staging strategy depends on beam parameters and method of acceleration. C1 Fermilab Natl Accelerator Lab, Beams Div, Batavia, IL 60510 USA. RP Johnstone, CJ (reprint author), Fermilab Natl Accelerator Lab, Beams Div, POB 500, Batavia, IL 60510 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7939-X PY 2003 BP 964 EP 973 PG 10 WC Automation & Control Systems; Physics, Applied SC Automation & Control Systems; Physics GA BX87L UT WOS:000186707400171 ER PT B AU Parsa, Z Zadorozhny, V Rudenko, A AF Parsa, Z Zadorozhny, V Rudenko, A GP IEEE IEEE TI Control theory to accelerator research and self-focused bunched beam SO 2003 INTERNATIONAL CONFERENCE PHYSICS AND CONTROL, VOLS 1-4, PROCEEDINGS: VOL 1: PHYSICS AND CONTROL: GENERAL PROBLEMS AND APPLICATIONS; VOL 2: CONTROL OF OSCILLATIONS AND CHAOS; VOL 3: CONTROL OF MICROWORLD PROCESSES. NANO- AND FEMTOTECHNOLOGIES; VOL 4: NONLINEAR DYNAMICS AND CONTROL LA English DT Proceedings Paper CT International Conference on Physics and Control (PHYSCON 2003) CY AUG 20-22, 2003 CL ST PETERSBURG, RUSSIA SP Russian Acad Sci, St Petersburg Sci Ctr, St Petersburg Grp Russian Natl Comm Automat Control, St Petersburg Informat & Control Soc, Russian Acad Sci, Inst Problem Mech Engn, St Petersburg State Univ, European Phys Soc, Int Union Theoret & Appl Mech, IEEE Control Syst Soc, IEEE Circuits & Syst Soc, Russia N IEEE Sect, Russia W IEEE Sect, EPS Interdivis Grp Expt Phys Control Syst, Cent Sci & Res Inst, City Univ Hong KOng AB A new approach to a nonlinear bunched beam dynamics based on the self-consistent Vlasov equation is presented. The man emphasis is given on the direct. Lyapunov method in case of a vector field (on a compact manifold with a singular point) to finding a solution to Vlasov - Poisson equation (VPE). The VPE is transformed into a Fredholm equation in an attraction region. These propertied are linked to the self-focusing and acceleration of a bunched beam. C1 Brookhaven Natl Lab, Dept Phys 901, Upton, NY 11973 USA. RP Parsa, Z (reprint author), Brookhaven Natl Lab, Dept Phys 901, Upton, NY 11973 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 BN 0-7803-7939-X PY 2003 BP 991 EP 996 PG 6 WC Automation & Control Systems; Physics, Applied SC Automation & Control Systems; Physics GA BX87L UT WOS:000186707400177 ER PT B AU Divan, R Mancini, DC Moldovan, N Assoufid, L Chu, YS Ma, Q Rosenberg, RA AF Divan, R Mancini, DC Moldovan, N Assoufid, L Chu, YS Ma, Q Rosenberg, RA GP IEEE IEEE TI X-ray patterned deposition of gold nanoparticles from solution SO 2003 INTERNATIONAL SEMICONDUCTOR CONFERENCE, VOLS 1 AND 2, PROCEEDINGS LA English DT Proceedings Paper CT 26th International Semiconductor Conference (CAS 2003) CY SEP 28-OCT 02, 2003 CL Sinaia, ROMANIA SP Natl Inst Res & Dev Microtechnol, IEEE Electron Devices Soc, Minist Educ, Res Youth, IEEE Romania Sect, Electron Devices Chapter DE nanoclusters; nanoparticles; high-energy x-rays; metallic deposition; x-ray diffraction ID ADVANCED PHOTON SOURCE; LITHOGRAPHY; IRRADIATION AB High-energy synchrotron radiation was used to induce the deposition of gold nanoparticles from a gold-salt solution onto a silicon dioxide surface. The nanoparticles distribution and film morphology depend on the x-ray dose. The average lateral grain size is about 100 nm. The particles exhibit a (111) preferred orientation normal to the substrate. The properties of the nanoclusters depend on the solution chemistry and deposition conditions. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Divan, R (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 10 TC 0 Z9 0 U1 3 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7821-0 PY 2003 BP 39 EP 42 DI 10.1109/SMICND.2003.1251340 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Optics; Physics GA BY80W UT WOS:000189468100005 ER PT B AU Liu, XM Maly, K Zubair, M Nelson, ML AF Liu, XM Maly, K Zubair, M Nelson, ML BE Marshall, CC Henry, G Delcambre, L TI Repository synchronization in the OAI framework SO 2003 JOINT CONFERENCE ON DIGITAL LIBRARIES, PROCEEDINGS LA English DT Proceedings Paper CT Joint Conference on Digital Libraries CY MAY 27-31, 2003 CL RICE UNIV, HOUSTON, TX SP IEEE TC Digital Lib, ACM SIGIR, ACM SIGWEB, Coalit Networked Informat, DELOS, Amer Soc Informat Sci & Technol HO RICE UNIV AB The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) began as an alternative to distributed searching of scholarly eprint repositories. The model embraced by the OAI-PMH is that of metadata harvesting, where value-added services (by a "service provider") are constructed on cached copies of the metadata extracted from the repositories of the harvester's choosing. While this model dispenses with the well known problems of distributed searching, it introduces the problem of synchronization. Stated simply, this problem arises when the service provider's copy of the metadata does not match the metadata currently at the constituent repositories. We define some metrics for describing the synchronization problem in the OAI-PMH. Based on these metrics, we study the synchronization problem of the OAI-PMH framework and propose several approaches for harvesters to implement better synchronization. In particular if a repository knows its update frequency, it can publish it in an OAI-PMH Identify response using an optional About container that borrows from RDF Site Syndication (RSS) Format. C1 Los Alamos Natl Lab, Res Lib, Los Alamos, NM 87545 USA. RP Liu, XM (reprint author), Los Alamos Natl Lab, Res Lib, POB 1663, Los Alamos, NM 87545 USA. OI Nelson, Michael/0000-0003-3749-8116 NR 17 TC 0 Z9 0 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 0-7695-1939-3 PY 2003 BP 191 EP 198 PG 8 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA BW95C UT WOS:000183728000025 ER PT B AU Hochstenbach, P Jerez, H Van de Sompel, H AF Hochstenbach, P Jerez, H Van de Sompel, H BE Marshall, CC Henry, G Delcambre, L TI The OAI-PMH static repository and static repository gateway SO 2003 JOINT CONFERENCE ON DIGITAL LIBRARIES, PROCEEDINGS LA English DT Proceedings Paper CT Joint Conference on Digital Libraries CY MAY 27-31, 2003 CL RICE UNIV, HOUSTON, TX SP IEEE TC Digital Lib, ACM SIGIR, ACM SIGWEB, Coalit Networked Informat, DELOS, Amer Soc Informat Sci & Technol HO RICE UNIV DE OAI-PMH; metadata harvesting AB Although the OAI-PMH specification is focused on making it straightforward for data providers to expose metadata, practice shows that in certain significant situations deployment of OAI-PMH conformant repository software remains problematic. In this paper, we report on research aimed at devising solutions to further lower the barrier to make metadata collections harvestable. We provide an in depth description of an approach in which a data provider makes a metadata collection available as an XML file with a specific format - an OAI Static Repository - which is made OAI-PMH harvestable through the intermediation of software - an OAI Static Repository Gateway - operated by a third party. We describe the properties of both components, and provide insights in our experience with an experimental implementation of a Gateway. C1 Los Alamos Natl Lab, Res Lib, Prototyping Team, Los Alamos, NM 87545 USA. RP Hochstenbach, P (reprint author), Los Alamos Natl Lab, Res Lib, Prototyping Team, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 4 Z9 4 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 0-7695-1939-3 PY 2003 BP 210 EP 217 DI 10.1109/JCDL.2003.1204865 PG 8 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA BW95C UT WOS:000183728000027 ER PT B AU Feng, W Vanichpun, S AF Feng, W Vanichpun, S GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Enabling compatibility between TCP Reno and TCP vegas SO 2003 SYMPOSIUM ON APPLICATIONS AND THE INTERNET, PROCEEDINGS LA English DT Proceedings Paper CT International Symposium on Applications and the Internet CY JAN 27-31, 2003 CL ORLANDO, FL SP IEEE Comp Soc, Informat Proc Soc Japan DE TCP Reno; TCP Vegas; congestion control; congestion avoidance; compatibility; fairness; convergence AB Despite research showing the superiority of TCP Vegas over TCP Reno, Reno is still the most widely deployed variant of TCP This predicament is due primarily to the alleged incompatibility of Vegas with Reno. While Vegas in isolation performs better with respect to overall network utilization, stability, fairness, throughput and packet loss, and burstiness; its performance is generally mediocre in any environment where Reno connections exist. Hence, there exists no incentive for any operating system to adopt TCP Vegas. In this paper we show that the accepted (default) configuration of Vegas is indeed incompatible with TCP Reno. However with a careful analysis of how Reno and Vegas use buffer space in routers, Reno and Vegas can be compatible with one another if Vegas is configured properly. Furthermore, we show that overall network performance actually improves with the addition of properly configured Vegas flows competing head-to-head with Reno flows. C1 Los Alamos Natl Lab, Comp & Computat Sci Div, Los Alamos, NM 87544 USA. RP Feng, W (reprint author), Los Alamos Natl Lab, Comp & Computat Sci Div, Los Alamos, NM 87544 USA. NR 15 TC 9 Z9 12 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 0-7695-1872-9 PY 2003 BP 301 EP 308 DI 10.1109/SAINT.2003.1183063 PG 8 WC Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA BW17R UT WOS:000181075200041 ER PT B AU Chambers, SA AF Chambers, SA GP IEEE IEEE TI Nucleation, growth, electronic and magnetic properties of epitaxial co-doped TiO2 anatase SO 2003 THIRD IEEE CONFERENCE ON NANOTECHNOLOGY, VOLS ONE AND TWO, PROCEEDINGS LA English DT Proceedings Paper CT 3rd IEEE Conference on Nanotechnology (IEEE-NANO 2003) CY AUG 12-14, 2003 CL SAN FRANCISCO, CA SP IEEE Nanotechnol Council, IEEE Reg 6 Western ID THIN-FILMS; TITANIUM-DIOXIDE; SILICON; FERROMAGNETISM; SPINTRONICS; OXIDES AB Co-doped TiO2 anatase (CoxTi1-xO2-x), as grown by oxygen plasma assisted molecular beam epitaxy, has been shown to be strongly ferromagnetic up to similar to700K. The robust magnetism is tied to the presence of a secondary phase of Co-enriched anatase, which appears as nano- and mesoscale epitaxial particles that nucleate on the surface of continuous anatase epitaxial films. Co in both secondary (concentrated) and primary (dilute) phases substitutes for Ti, and is in the +2 formal oxidation state. The magnetization is proportional to the n-type conductivity, suggesting electron mediated exchange interaction. This material may thus be useful in the rapidly developing field of spintronics for which ferromagnetic semiconductors with Curie points well above room temperature are critically important. C1 Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7976-4 PY 2003 BP 9 EP 12 PG 4 WC Chemistry, Applied; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Materials Science; Physics GA BX48B UT WOS:000185389900003 ER PT B AU Shutthanandan, V Thevuthasan, S Engelhard, MH Droubay, T Heald, SM Saraf, LV Chambers, SA Taylor, B Sears, RP Sinkovic, B Mun, BS AF Shutthanandan, V Thevuthasan, S Engelhard, MH Droubay, T Heald, SM Saraf, LV Chambers, SA Taylor, B Sears, RP Sinkovic, B Mun, BS GP IEEE IEEE TI Characterization of ferromagnetic Co-implanted rutile TiO2(110) SO 2003 THIRD IEEE CONFERENCE ON NANOTECHNOLOGY, VOLS ONE AND TWO, PROCEEDINGS LA English DT Proceedings Paper CT 3rd IEEE Conference on Nanotechnology (IEEE-NANO 2003) CY AUG 12-14, 2003 CL SAN FRANCISCO, CA SP IEEE Nanotechnol Council, IEEE Reg 6 Western ID DOPED TIO2 ANATASE; EPITAXIAL-GROWTH; FILMS; SPINTRONICS AB Co ions of energy 100 KeV and fluences between 1.25x10(16) and 5.0x10(16) Co+/cm(2) were implanted in single crystal TiO2(110) substrates at temperatures of 300, 875 and 1075K. Co depth profiles were obtained using x-ray photoelectron spectroscopy and Rutherford backscattering spectrometry. The Co diffused to a much greater depth when implanted at 1075 K compared to implantation at lower temperatures. The valence state of Co was investigated using Co K and L edge x-ray absorption near edge spectra. Although implantation at lower temperatures results in a mixture of metallic and oxidized Co, implantation at 1075 K results in no measurable Co(0) in the sample. The magnetic properties were investigated using magneto-optical Kerr-effect and vibrating sample magnetometer. The sample implanted at 1075K shows ferromagnetic properties at room temperature. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Shutthanandan, V (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; OI Engelhard, Mark/0000-0002-5543-0812 NR 17 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7976-4 PY 2003 BP 13 EP 15 PG 3 WC Chemistry, Applied; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Materials Science; Physics GA BX48B UT WOS:000185389900004 ER PT B AU Saraf, L Shutthanandan, V Wang, CM Zhang, YW Marina, O Thevuthasan, S AF Saraf, L Shutthanandan, V Wang, CM Zhang, YW Marina, O Thevuthasan, S GP IEEE IEEE TI Oxygen diffusion in nanocrystalline CeO2 SO 2003 THIRD IEEE CONFERENCE ON NANOTECHNOLOGY, VOLS ONE AND TWO, PROCEEDINGS LA English DT Proceedings Paper CT 3rd IEEE Conference on Nanotechnology (IEEE-NANO 2003) CY AUG 12-14, 2003 CL SAN FRANCISCO, CA SP IEEE Nanotechnol Council, IEEE Reg 6 Western ID OXIDE FUEL-CELL; ELECTRICAL-CONDUCTIVITY; SURFACE; TECHNOLOGIES; ZIRCONIA; EXCHANGE; CERIA AB In this study, O-18 diffusion and related transport on 1-2 gm thick nanocrystalline ceria films prepared by sol-gel process with an average grain-size in the range of 3-38 nm are studied. Initial O-18 diffusion results indicate increased diffusion in 6 nm average grain-size nano-ceria films compared to similar to 38 nm average grain-size poly-ceria films. Conductivity values in the case of similar to 3 nm average grain size CeO2 films grown at 573 K observed to be marginally increased compared to similar to 6 nm average grain size ceria films grown at 723 K. A detailed nano-grain analysis by high-resolution transmission electron microscopy (HRTEM) was carried out to understand the effect of nanocrystallinity on the blocking phenomena. C1 Pacific NW Natl Lab, Fundamental Sci Directorate, Richland, WA 99352 USA. RP Saraf, L (reprint author), Pacific NW Natl Lab, Fundamental Sci Directorate, Richland, WA 99352 USA. 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 BN 0-7803-7976-4 PY 2003 BP 477 EP 479 PG 3 WC Chemistry, Applied; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Materials Science; Physics GA BX48B UT WOS:000185389900123 ER PT B AU Thevuthasan, S Azad, S Marina, OA Shutthanandan, V McCready, DE Saraf, L Wang, CM Lyubinetsky, I Peden, CHF Petrovsky, V AF Thevuthasan, S Azad, S Marina, OA Shutthanandan, V McCready, DE Saraf, L Wang, CM Lyubinetsky, I Peden, CHF Petrovsky, V GP IEEE IEEE TI Influence of multiple interfaces on oxygen ionic conductivity in gadolinia-doped single crystal oxide electrolyte multi-layer nano films SO 2003 THIRD IEEE CONFERENCE ON NANOTECHNOLOGY, VOLS ONE AND TWO, PROCEEDINGS LA English DT Proceedings Paper CT 3rd IEEE Conference on Nanotechnology (IEEE-NANO 2003) CY AUG 12-14, 2003 CL SAN FRANCISCO, CA SP IEEE Nanotechnol Council, IEEE Reg 6 Western ID GROWTH AB Single-crystal multi-layered thin films of pure and gadolinia-doped ceria and zirconia were heteroepitaxially grown on sapphire (0001) substrates using molecular beam epitaxy. The growth of these films was monitored using in-situ reflection high-energy electron diffraction (RHEED). In addition, the ex-situ characterization techniques including x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) along with ion channeling were used to further characterize these films. The electrical conductivity in these films was measured using a four-probe van der Pauw technique. Oxygen ionic conductivity at low temperatures appeared to be higher in the four-layer film compared to two-layer film. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Thevuthasan, S (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 16 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7976-4 PY 2003 BP 550 EP 552 PG 3 WC Chemistry, Applied; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Materials Science; Physics GA BX48B UT WOS:000185389900143 ER PT B AU Lyubinetsky, I Thevuthasan, S McCready, DE Lea, AS Baer, DR AF Lyubinetsky, I Thevuthasan, S McCready, DE Lea, AS Baer, DR GP IEEE IEEE TI Formation of self-assembled cuprous oxide nano-dots on SrTiO(3)(001)Surfaces SO 2003 THIRD IEEE CONFERENCE ON NANOTECHNOLOGY, VOLS ONE AND TWO, PROCEEDINGS LA English DT Proceedings Paper CT 3rd IEEE Conference on Nanotechnology (IEEE-NANO 2003) CY AUG 12-14, 2003 CL SAN FRANCISCO, CA SP IEEE Nanotechnol Council, IEEE Reg 6 Western ID NANOCRYSTALS; SURFACES; GROWTH; CU2O AB Formation of self-assembled crystalline cuprous oxide (Cu(2)O) nanoclusters on the SrTiO(3)(001) substrate have been observed using oxygen plasma assisted molecular beam epitaxy (OPA MBE). The composition and structure were examined by x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), x-ray diffraction (XRD), and atomic force microscopy (AFM) in a wide range of growth parameters (temperature, oxygen pressure, and Cu flux). The parameters were optimized to obtain Cu(2)O as a single phase in these structures. Understanding of the evolution of the dot shape, size and composition would allow us to optimize formation conditions to synthesize cuprous oxide nanodots with desirable parameters. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Lyubinetsky, I (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Baer, Donald/J-6191-2013; OI Baer, Donald/0000-0003-0875-5961; Lea, Alan/0000-0002-4232-1553 NR 19 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7976-4 PY 2003 BP 667 EP 670 PG 4 WC Chemistry, Applied; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Materials Science; Physics GA BX48B UT WOS:000185389900174 ER PT B AU Sorescu, DC Boatz, JA Thompson, DL AF Sorescu, DC Boatz, JA Thompson, DL GP IEEE COMPUTER SOCIETY TI First-principles calculations of the adsorption of nitromethane and 1,1-diamino-2,2-dinitroethylene (FOX-7) molecules on the Al(111) surface SO 2003 USERS GROUP CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT Users Group 2003 Conference CY JUN 09-13, 2003 CL Bellevue, WA SP Dept Defense High Performance Comp Modernizat Program ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; METALS; DYNAMICS AB First-principles calculations based on density functional theory (DFT) and the generalized gradient approximation (GGA) have been used to study the adsorption of nitromethane (NM) and 1,1-diamino-2,2-dinitroethylene (FOX-7) molecules on the Al(111) surface. Both dissociative and nondissociative adsorption mechanisms are predicted. O-atom abstraction by Al surface atoms is seen to be the dominant mechanism of dissociative chemisorption. For nondissociative adsorption, various N-O-Al bridge-type bonding configurations can be formed. Therefore, oxidation of the aluminum surface readily occurs, either by partial or complete dissociation of the oxygen atoms from the NO2 group. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Sorescu, DC (reprint author), US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. EM dsorescu+@pitt.edu; jerry.boatz@edwards.af.mil; dlt@okstate.edu NR 12 TC 0 Z9 0 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 0-7695-1953-9 PY 2003 BP 16 EP 19 DI 10.1109/DODUGC.2003.1253366 PG 4 WC Computer Science, Interdisciplinary Applications SC Computer Science GA BY55Y UT WOS:000189408300003 ER PT S AU Otoo, E Shoshani, A AF Otoo, E Shoshani, A BE Titsworth, F TI Accurate modeling of cache replacement policies in a data grid SO 20TH IEEE/11TH NASA GODDARD CONFERENCE ON MASS STORAGE AND TECHNOLOGIES (MSST 2003), PROCEEDINGS SE IEEE Symposium on Mass Storage Systems and Technologies Proceedings-MSST LA English DT Proceedings Paper CT 20th IEEE Conference on Mass Storage Systems and Technology/11th NASA Goddard Conference on Mass Storage Systems and Technology CY APR 07-10, 2003 CL SAN DIEGO, CA SP IEEE Mass Storage Syst Tech omm, NASA Goddard Space Flight Ctr ID MANAGEMENT AB Caching techniques have been used to improve the performance gap of storage hierarchies in computing systems. In data intensive applications that access large data files over wide area network environment, such as a data grid, caching mechanism can significantly improve the data access performance under appropriate workloads. In a data grid, it is envisioned that local disk storage resources retain or cache the data files being used by local application. Under a workload of shared access and high locality of reference, the performance of the caching techniques depends heavily on the replacement policies being used A replacement policy effectively determines which set of objects must be evicted when space is needed Unlike cache replacement policies in virtual memory paging or database buffering, developing an optimal replacement policy for data grids is complicated by the fact that the file objects being cached have varying sizes and varying transfer and processing costs that vary with time. We present an accurate model for evaluating various replacement policies and propose a new replacement algorithm referred to as Least Cost Beneficial based on K backward references (LCB-K). Using this modeling technique, we compare LCB-K with various replacement policies such as Least Frequently Used (LFU), Least Recently Used (LRU), Greedy Dual Size (GDS), etc., using synthetic and actual workload of accesses to and from tertiary storage systems. The results obtained show that (LCB-K) and (GDS) are the most cost effective cache replacement policies for storage resource management in data grids. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 50B-3238, Berkeley, CA 94720 USA. NR 17 TC 3 Z9 4 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 SN 2160-195X BN 0-7695-1914-8 J9 IEEE S MASS STOR SYS PY 2003 BP 10 EP 19 DI 10.1109/MASS.2003.1194831 PG 10 WC Computer Science, Hardware & Architecture SC Computer Science GA BW72H UT WOS:000182973500002 ER PT S AU Bakken, J Berman, E Huang, CH Moibenko, A Petravick, D Zalokar, M AF Bakken, J Berman, E Huang, CH Moibenko, A Petravick, D Zalokar, M BE Titsworth, F TI The Fermilab data storage infrastructure SO 20TH IEEE/11TH NASA GODDARD CONFERENCE ON MASS STORAGE AND TECHNOLOGIES (MSST 2003), PROCEEDINGS SE IEEE SYMPOSIUM ON MASS STORAGE SYSTEMS - PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE Conference on Mass Storage Systems and Technology/11th NASA Goddard Conference on Mass Storage Systems and Technology CY APR 07-10, 2003 CL SAN DIEGO, CA SP IEEE Mass Storage Syst Tech omm, NASA Goddard Space Flight Ctr AB Fermilab, in collaboration with the DESY laboratory in Hamburg, Germany, has created a petabyte scale data storage infrastructure to meet the requirements of experiments to store and access large data sets. The Fermilab data storage infrastructure consists of the following major storage and data transfer components: Enstore mass storage system, DCache distributed data cache, ftp, and Grid ftp for primarily external data transfers. This infrastructure provides a data throughput sufficient for transferring data from experiments' data acquisition systems. It also allows access to data in the Grid framework. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bakken, J (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 3 TC 1 Z9 1 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 SN 1051-9173 BN 0-7695-1914-8 J9 IEEE S MASS STOR SYS PY 2003 BP 101 EP 104 DI 10.1109/MASS.2003.1194845 PG 4 WC Computer Science, Hardware & Architecture SC Computer Science GA BW72H UT WOS:000182973500016 ER PT B AU Lagin, L Bryant, R Carey, R Casavant, D Demaret, R Edwards, O Ferguson, W Krammen, J Larson, D Lee, A Ludwigsen, P Miller, M Moses, E Nyholm, R Reed, R Shelton, R Van Arsdall, PJ Wuest, C AF Lagin, L Bryant, R Carey, R Casavant, D Demaret, R Edwards, O Ferguson, W Krammen, J Larson, D Lee, A Ludwigsen, P Miller, M Moses, E Nyholm, R Reed, R Shelton, R Van Arsdall, PJ Wuest, C GP ieee TI Status of the National Ignition Facility integrated computer control system SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest and most energetic laser experimental system, providing an international center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's 192 energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Laser hardware is modularized into line replaceable units such as deformable mirrors, amplifiers, and multi-function sensor packages that are operated by the Integrated Computer Control System (ICCS). ICCS is a layered architecture of 300 front-end processors attached to nearly 60,000 control points and coordinated by supervisor subsystems in the main control room. The functional subsystems - beam control including automatic beam alignment and wavefront correction, laser pulse generation and pre-amplification, diagnostics, pulse power, and timing implement automated shot control, archive data, and support the actions of fourteen operators at graphic consoles. Object-oriented software development uses a mixed language environment of Ada (for functional controls) and Java (for user interface and database backend). The ICCS distributed software framework uses CORBA to communicate between languages and processors. ICCS software is approximately 3/4 complete with over 750 thousand source lines of code having undergone off-line verification tests and deployed to the facility. NIF has entered the first phases of its laser commissioning program. NIF has now demonstrated the highest energy 1omega, 2omega, and 3omega beamlines in the world. NIF's target experimental systems are also being installed in preparation for experiments to begin in late 2003. This talk will provide a detailed look at the status of the control system. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lagin, L (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94551 USA. NR 6 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 27 EP 30 DI 10.1109/FUSION.2003.1425870 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700006 ER PT B AU Zatz, IJ AF Zatz, IJ GP ieee TI Final examination and testing of the TFTR TF-coils SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB In operation for nearly 15 years, the Tokamak Fusion Test Reactor (TFTR) was not only a fusion science milestone, but a milestone of achievement in engineering as well. The TFTR Decontamination and Decommissioning (D&D) program provided a rare opportunity to examine machine components that had been exposed to a unique performance environment of greater than 100,000 mechanical and thermal load cycles. In particular, the examination of the TFTR Toroidal Field (TF) coils, which met then exceeded the 5.2 Tesla magnetic field machine specification, could supply the answers to many questions that have been asked and debated since the coils were originally designed and built. A test program conducted in parallel with the D&D effort was the chance to look inside and examine, in detail, the TFTR TF coils for the first time since they were delivered encased to PPPL. This program set aside a number of selected sections from the twenty TFTR TF coils as they were removed during D&D. These sections were cut from the coils in several different areas including the nose, back leg, water fitting and lead block regions, concentrating on those known areas whose performance was questioned during TFTR operations. The test program included documented visual inspections and photography during all phases of disassembly and testing. Physical examinations of the coils were performed to determine consistency of coil manufacturing techniques, including status of the potting compound, quality of turn-to-turn epoxy impregnation and bonding, and determination of the cause of coolant leaks during operation. Selected chemical and metallurgical analyses were conducted to determine if the composition of the materials have altered and to identify unknown materials. Multiple mechanical test samples in various orientations were cut from several magnet and case locations to check for consistency and range of material properties. This paper discusses the findings of the test program. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Zatz, IJ (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 31 EP 34 DI 10.1109/FUSION.2003.1425871 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700007 ER PT B AU Neumeyer, C Brooks, A Chrzanowski, J Dudek, L Heitzenroeder, P Kalish, M Williams, M Zatz, I AF Neumeyer, C Brooks, A Chrzanowski, J Dudek, L Heitzenroeder, P Kalish, M Williams, M Zatz, I GP ieee TI NSTX TF joint failure and re-design SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The Toroidal Field (TF) coil of the National Spherical Torus Experiment (NSTX) [1] suffered a failure on February 14, 2003, after approximately 3 years of service and 7200 pulses. The failure occurred at an electrical joint connecting one of the radial flags to the inner leg bundle. Damage was extensive such that the coil could not be repaired. Analysis of the failure revealed structural design problems which have been addressed in the redesign effort described herein. Construction of a new TF coil is now underway. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Neumeyer, C (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 35 EP 38 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700008 ER PT B AU Kugel, HW Anderson, M Barnes, G Bell, M Blanchard, W Dudek, L Gates, D Gernhardt, R Maingi, R Mueller, D Provost, T Raman, R Soukhanovskii, V AF Kugel, HW Anderson, M Barnes, G Bell, M Blanchard, W Dudek, L Gates, D Gernhardt, R Maingi, R Mueller, D Provost, T Raman, R Soukhanovskii, V GP ieee TI NSTX high field side gas fueling system SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID PLASMAS; BETA AB Fueling NSTX plasmas with gas injected from the high field side (HFS) has produced earlier, more reliable transitions to the H-mode, longer H-mode durations, higher toroidal rotation, and higher edge T-e compared with similar discharges using the low field side (LFS) gas fueling injectors. The HFS gas fueling system consists of a Center Stack midplane injector, and an injector at the inner, upper corner of the Center Stack. The challenging design and installation constraints for the HFS gas system involved placing the control components as close as possible to the machine-vacuum interface, devising a special feed-through flange, traversing through vessel regions whose temperatures during bake-out range from 150C to 350C, adapting the gas transport tubing size and route to the small instrumentation wire channels behind the existing graphite PFC tiles on the Center Stack, and providing output orifices shielded from excessive plasma power depositions while concentrating the output flow to facilitate fast camera viewing and analysis. Design, recent performance, and future upgrades will be presented. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kugel, HW (reprint author), Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 82 EP 85 DI 10.1109/FUSION.2003.1426593 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700019 ER PT B AU Lumia, M Gentile, C Creek, K Sandoval, R AF Lumia, M Gentile, C Creek, K Sandoval, R GP ieee TI Removable thin films used for the abatement and mitigation of a beryllium SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The use of removable thin films for the abatement of hazardous particulates has many advantages. Removable thin films are designed to trap and fix particulates in the film's matrix by adhesion. Thin films can be applied to an existing contaminated area to fix and capture the particulates for removal. The nature of the removable thin films, after sufficient cure time, is such that it can typically be removed as one continuous entity. The removable thin films can be applied to almost any surface type with a high success rate of removal. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lumia, M (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 168 EP 170 DI 10.1109/FUSION.2003.1426614 PG 3 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700039 ER PT B AU Gentile, CA Parsells, R Butler, JE Sethian, JD Ciebiera, L Hegeler, F Jun, C Langish, S Myers, M AF Gentile, CA Parsells, R Butler, JE Sethian, JD Ciebiera, L Hegeler, F Jun, C Langish, S Myers, M GP ieee TI The development of a hibachi window for electron beam SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB In support of Inertial Fusion Energy (IFE) a 150 pin thick silicon (Si) wafer coated on one side with a 1.2 mun nanocrystalline diamond foil is being fabricated as an electron beam transmission (hibachi) window for use in KrF lasers. The hibachi window separates the lasing medium from the electron beam source while allowing the electron beam to pass through. The hibachi window must be capable of withstanding the challenging environment presented in the lasing chamber, which include: fluorine gas, delta pressure > 2 atm @ 5 Hz, and a high heat flux due to the transmission of electrons passing through the foil. Tests at NRL / Electra and at PPPL have shown that a device employing these novel components in the stated configuration provide for a robust hibachi window with structural integrity. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Gentile, CA (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Butler, James/B-7965-2008 OI Butler, James/0000-0002-4794-7176 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 0-7803-7908-X PY 2003 BP 175 EP 176 DI 10.1109/FUSION.2003.1426616 PG 2 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700041 ER PT B AU Perry, E Chrzanowski, J Gentile, C Parsells, R Rule, K Strykowsky, R Viola, M AF Perry, E Chrzanowski, J Gentile, C Parsells, R Rule, K Strykowsky, R Viola, M GP ieee TI Decommissioning of the Tokamak Fusion Test Reactor SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory was operated from 1982 until 1997. The last several years included operations with mixtures of deuterium and tritium. In September 2002, the three year Decontamination and Decommissioning (D&D) Project for TFTR was successfully completed. The need to deal with tritium contamination as well as activated materials led to the adaptation of many techniques from the maintenance work during TFTR operations to the D&D effort. In addition, techniques from the decommissioning of fission reactors were adapted to the D&D of TFTR and several new technologies, most notably the development of a diamond wire cutting process for complex metal structures, were developed. These techniques, along with a project management system that closely linked the field crews to the engineering staff which developed the techniques and procedures, via a Work Control Center, resulted in a project which was completed safely, on time and well below budget. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Perry, E (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 256 EP 259 DI 10.1109/FUSION.2003.1426633 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700058 ER PT B AU Reyes, S Cadwallader, LC del Rio, JG Latkowski, JF Sanz, J AF Reyes, S Cadwallader, LC del Rio, JG Latkowski, JF Sanz, J GP ieee TI Safety issues of beryllium use in IFE power plants SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID HYLIFE-II; ACCIDENT CONSEQUENCES; TARGET MATERIALS; DESIGN AB Selection of materials for inertial fusion energy (IFE) power plant designs must consider a wide variety of factors such as performance, cost, ease of fabrication and safety and environmental (S&E) issues. In the past, we have performed a S&E assessment of mercury and lead as potential hohlraum materials, including for the first time a comparative analysis of the radiological and toxicological consequences of an accidental release. It was found that the chemical safety requirements dominate over radiological considerations. In the present work, we address the various safety issues regarding the use of beryllium in an IFE power plant. Beryllium is one of the constituents of the molten salt flibe (Li2BeF4), used in some IFE liquid-wall chamber concepts and also proposed as a candidate material in some target designs. Here, we want to assess the safety hazards of beryllium use in IFE, from both the radiological and the chemical toxicity points of view. For that purpose, we use the latest DOE regulations to compare potential accident scenarios with the Be concentration limits for public protection, to estimate the level of compliance of the safety standards. We also evaluate the effects from acute radiological and toxicological Be exposures. The results from this work demonstrate that whereas traditional IFE safety analyses have focused on radiological issues, chemical hazards must also be considered to provide a complete safety assessment for fusion power plants. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Reyes, S (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Cadwallader, Lee/F-6933-2014 NR 32 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 260 EP 263 DI 10.1109/FUSION.2003.1426634 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700059 ER PT B AU Heitzenroeder, P Brown, T Neilson, GH Reiersen, W Viola, M Malinowski, F Sutton, L Cole, M Nelson, B Williamson, D Goranson, P Keilbach, R AF Heitzenroeder, P Brown, T Neilson, GH Reiersen, W Viola, M Malinowski, F Sutton, L Cole, M Nelson, B Williamson, D Goranson, P Keilbach, R GP ieee TI Manufacturing development of the NCSX modular coil winding forms and vacuum vessel SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The National Compact Stellarator Experiment (NCSX) is the first of a new class of stellarators known as "compact stellarators". Stellarators are characterized by three dimensional magnetic fields and plasma shapes and are the best-developed class of magnetic fusion devices after the tokamak. Stellarators are attractive because they solve critical problems of magnetic fusion energy: steady state operation without current drive and stable operation without feedback control or rotation drive. The differentiating feature of the compact stellarator is the use of a small plasma current in conjunction with external magnetic fields to provide the required plasma shaping and confinement. This permits a more compact stellarator design. Many of the components of NCSX are conventional in design and manufacture; however, two of the most critical components, the vacuum vessel and the modular coil winding forms, are also the most challenging components to manufacture. This paper describes design of these two critical elements of NCSX and the three-phase program that is being used in the manufacturing development of these components. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Heitzenroeder, P (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 276 EP 279 DI 10.1109/FUSION.2003.1426638 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700063 ER PT B AU Nygren, RE Rognlien, TD Rensink, ME Smolentsev, S Nelson, BE Fogarty, PJ Eberle, C Ulrickson, MA AF Nygren, RE Rognlien, TD Rensink, ME Smolentsev, S Nelson, BE Fogarty, PJ Eberle, C Ulrickson, MA GP ieee TI Liquid surface divertor designs for fusion reactors SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID LITHIUM; RETENTION; FLOWS; HE; LI; EROSION/REDEPOSITION; DIFFUSIVITY; SYSTEMS; EROSION; SHEATH AB As part of work in the US on free flowing liquid surfaces facing the plasma, we are studying issues of integrating a liquid surface divertor into a configuration based upon an advanced tokamak (ARIES-RS) with the flow of the liquid first wall of molten salt Flinabe (Li, Na, Be fluorides) continuing to become the divertor. We present the design and thermal performance and issues in design integration such as the interactions with the plasma edge. Sn and Sn-Li have also been considered, although the complicated 3-D MHD flows cannot yet be fully modeled. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Nygren, RE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 28 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 284 EP 287 DI 10.1109/FUSION.2003.1426640 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700065 ER PT B AU Nygren, RE Sze, DK Nelson, BE Fogarty, P Eberle, C Rognlien, JD Rensink, ME Smolentsev, S Youssef, MZ Sawan, ME Merrill, BJ Majeski, R AF Nygren, RE Sze, DK Nelson, BE Fogarty, P Eberle, C Rognlien, JD Rensink, ME Smolentsev, S Youssef, MZ Sawan, ME Merrill, BJ Majeski, R GP ieee TI A fusion chamber design with a liquid first wall and divertor SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID HEAT DEPOSITION; POWER-PLANT; HYLIFE-II; LITHIUM; DENSITY; SURFACE; ARIES; SYSTEMS; FLIBE; PERFORMANCE AB The APEX study is investigating the use of free flowing liquid surfaces to form the inner surface of the chamber around a fusion plasma. We present a design for the chamber of a 3840MW fusion reactor based on the configuration for the chamber and magnets from ARIES-RS but with a fast flowing molten salt of mixed Be, Li and Na fluorides for the first wall and divertor and molten salt blanket with a ferritic steel structure. Our design analysis includes strong radiation from the core and edge plasma, (liquid) MHD effects on the weakly conducting molten salt, a recycling first wall stream that enables a high efficiency thermal conversion, and evaluations of breeding, neutronics, tritium recovery and safety. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Nygren, RE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 58 TC 1 Z9 1 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 288 EP 295 DI 10.1109/FUSION.2003.1426641 PG 8 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700066 ER PT B AU Kessel, CE Meade, D Swain, DW Titus, P Ulrickson, MA AF Kessel, CE Meade, D Swain, DW Titus, P Ulrickson, MA GP ieee TI Advanced tokamak Plasmas in the fusion ignition research experiment SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID HYBRID CURRENT DRIVE; STABILITY; SHEAR AB The Advanced Tokamak capability of the FIRE burning plasma experiment is examined with OD systems analysis, equilibrium and ideal MHD stability, RF current drive analysis, and full discharge dynamic simulations. These analyses have identified the required parameters for attractive burning AT plasmas, and indicate that these are feasible within the engineering constraints of the device. C1 Princeton Plasma Phys Lab, Princeton, NJ 08534 USA. RP Kessel, CE (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08534 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 0-7803-7908-X PY 2003 BP 296 EP 299 DI 10.1109/FUSION.2003.1426642 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700067 ER PT B AU Neumeyer, C Kessel, C Peng, M Rutherford, P AF Neumeyer, C Kessel, C Peng, M Rutherford, P GP ieee TI Design point studies for future spherical torus avices SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID ASPECT RATIO AB A Systems Code analysis has been developed which provides a tool for the assessment of design points for future spherical torus (ST) devices. The code includes algorithms for plasma physics as well as engineering aspects, which are necessarily simplified but sufficient to capture the essential design-driving considerations. This paper describes the methodology and presents some example cases from ongoing studies. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Neumeyer, C (reprint author), Princeton Plasma Phys Lab, POB 451, 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 0-7803-7908-X PY 2003 BP 304 EP 307 DI 10.1109/FUSION.2003.1426644 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700069 ER PT B AU Nelson, B Benson, R Berry, L Brooks, A Cole, M Fogarty, P Fortier, G Freudenberg, K Goranson, P Hargrove, T Heitzenroeder, P Hirshman, S Jones, G Lovett, G Lyon, J Madhukar, M Mioduszewski, P Monticello, D Neilson, G Parang, M Spong, D Strickler, D Ware, A Williamson, D AF Nelson, B Benson, R Berry, L Brooks, A Cole, M Fogarty, P Fortier, G Freudenberg, K Goranson, P Hargrove, T Heitzenroeder, P Hirshman, S Jones, G Lovett, G Lyon, J Madhukar, M Mioduszewski, P Monticello, D Neilson, G Parang, M Spong, D Strickler, D Ware, A Williamson, D GP ieee TI Engineering design of the Quasi-Poloidal Stellarator (QPS) SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The engineering design status of the Quasi-Poloidal Stellarator Experiment (QPS) is presented. The overall configuration and the design, manufacturing and assembly techniques of the various components of the core are described. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Nelson, B (reprint author), Oak Ridge Natl Lab, POB 2009, Oak Ridge, TN 37831 USA. RI Spong, Donald/C-6887-2012 OI Spong, Donald/0000-0003-2370-1873 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 0-7803-7908-X PY 2003 BP 308 EP 311 DI 10.1109/FUSION.2003.1426645 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700070 ER PT B AU Ku, LP AF Ku, LP CA ARIES-CS Team GP ieee TI A compact quasi-axisymmetric stellarator reactor SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB We report the progress made in assessing the potential of compact, quasi-axisymmetric stellarators as powerproducing reactors. Using an aspect ratio A=4.5 configuration derived from NCSX and optimized with respect to the quasiaxisymmetry and MRD stability in the linear regime as an example, we show that a reactor of 1 GW(e) maybe realizable with a major radius less than or equal to8 m. This is significantly smaller than the designs of stellarator reactors attempted before. We further show the design of modular coils and discuss the optimization of coil aspect ratios in order to accommodate the blanket for tritium breeding and radiation shielding for coil protection. In addition, we discuss the effects of coil aspect ratio on the peak magnetic field in the coils. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Ku, LP (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 312 EP 315 DI 10.1109/FUSION.2003.1426646 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700071 ER PT B AU Woolley, RD AF Woolley, RD GP ieee TI Progress on a steady-state tokamak magnetic field sensor - Accurate for unlimited time durations for fusion reactors SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB A novel hybrid method for accurate magnetic field measurements in steady-state or long-pulse tokamaks, described in a 1995 publication and patented in 1998, has not yet been tested in a tokamak. Recent development progress is described herein. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Woolley, RD (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 351 EP 354 DI 10.1109/FUSION.2003.1426656 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700081 ER PT B AU Feder, R Renda, GF Johnson, D Lowrance, JL Mastrocola, VJ Stratton, B von Goeler, S AF Feder, R Renda, GF Johnson, D Lowrance, JL Mastrocola, VJ Stratton, B von Goeler, S GP ieee TI Fast tangential soft x-ray camera for NSTX SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The National Spherical Torus Experiment (NSTX) Fast Tangential Soft X-Ray Camera (FTSXC) collects soft x-ray images (0.5-5 keV) at frame rates up to 500 KHz for the study of MHD events such as sawtooth crashes. The camera has a wide angle (28degrees) tangential view of the plasma. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Feder, R (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 355 EP 358 DI 10.1109/FUSION.2003.1426657 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700082 ER PT B AU Gettelfinger, G Dong, J Gernhardt, R Kugel, H Sichta, P Timberlake, J AF Gettelfinger, G Dong, J Gernhardt, R Kugel, H Sichta, P Timberlake, J GP ieee TI Lithium pellet injector development for NSTX SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB A pellet injector suitable for the injection of lithium and other low-Z pellets of varying mass into plasmas at precise velocities from 5 to 500 m/s is being developed for use on NSTX. The ability to inject low-Z impurities will significantly expand NSTX experimental capability for a broad range of diagnostic and operational applications. The architecture employs a pellet-carrying cartridge propelled through a guide tube by deuterium gas. Abrupt deceleration of the cartridge at the end of the guide tube results in the pellet continuing along its intended path, thereby giving controlled reproducible velocities for a variety of pellets materials and a reduced gas load to the torus. The planned injector assembly has four hundred guide tubes contained in a rotating magazine with eight tubes provided for injection into plasmas. A PC-based control system is being developed as well and will be described elsewhere in these Proceedings. The development path and mechanical performance of the injector will be described. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Gettelfinger, G (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 2 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 359 EP 362 DI 10.1109/FUSION.2003.1426658 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700083 ER PT B AU Lutz, TJ Nygren, RE Tanaka, TJ McDonald, JM Bauer, FJ Troncosa, KP Ulrickson, MA AF Lutz, TJ Nygren, RE Tanaka, TJ McDonald, JM Bauer, FJ Troncosa, KP Ulrickson, MA GP ieee TI Measurements of lithium flow with an EM flow meter in LIMITS SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB A simple electromagnetic flow meter was constructed and used in the one-inch thick-walled 316L stainless steel tubing (20.6 mm W.) of LIMITS, an experimental lithium flow loop at Sandia National Laboratories. (A parallel paper in this conference by Tanaka et al describes LIMITS.) The flow meter uses a pair of NdFeB permanent magnets (57.2mmW x 48.3mmD x 76.2mmH) mounted on an iron yoke producing a field of about 0.5 Tesla. This paper describes the field measurements, calibration and use of the flow meter in experiments with flowing lithium. Initial calibration of the meter was done as lithium was moved using gas pressure from a transfer tank to the lithium furnace. In this calibration, we monitored the signal from the flow meter and the signal from a previously uncalibrated level meter in the lithium furnace. The reference for the calibration was the change in weight of the transfer tank, which we measured using a set of load cells under the sled supporting the tank. The flow meter signal ranged from 0 to about 6 mV for flow speeds of 0 to about 1 m/s. There was, as expected, some noise with the mV signal, but use of a running average essentially eliminated the noise. The signal was quite linear with flow as judged by the correspondence between the integrated flow signal and the weight of lithium transferred. We also have used the flow meter in lithium flow experiments in LIMITS and these data and the calibration procedure will be reported in the paper. Among the observed effects during the flow tests was a difficulty in interpreting the signal whenever vibration of stainless steel tubing occurred due to the (usually smooth running) pump or changes in the valve positions, for example, opening a valve with the pump running. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lutz, TJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 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 0-7803-7908-X PY 2003 BP 367 EP 370 DI 10.1109/FUSION.2003.1426660 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700085 ER PT B AU Ramakrishnan, S Neumeyer, C Marsala, R Schneider, H Gernhardt, R Baker, E AF Ramakrishnan, S Neumeyer, C Marsala, R Schneider, H Gernhardt, R Baker, E GP ieee TI Ground fault detection in NSTX coil power system SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physic Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The NSTX power system has eleven (11) circuits. Each circuit is a floating DC system. Ground detection and protection device is provided for each circuit. The TFTR ground detection scheme had to be modified for the new application. The Coaxial Helicity Injection System (CHI) requires special scheme to detect grounds in the main power loop since the circuit can be back fed from during Neutral Beam Injection. For CHI, the vacuum vessel is divided into a) Inner vessel and b) Outer Vessel, insulated from one another. Special Ground Protection devices are being designed for the CHI. An additional system to detect grounds and generate alarms while performing maintenance on the vacuum vessel has also been installed. This was necessary to maintain the insulation integrity of the vessel. Also techniques used to trouble shoot vessel grounds are outlined. This paper describes the changes and addition to the Electrical Power Circuit ground detection and monitoring for the NSTX magnet systems and CHI electrodes. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Ramakrishnan, S (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 383 EP 386 DI 10.1109/FUSION.2003.1426664 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700089 ER PT B AU Sichta, P Dong, J Gernhardt, R Gettelfinger, G Kugel, H AF Sichta, P Dong, J Gernhardt, R Gettelfinger, G Kugel, H GP ieee TI Control system for the NSTX Lithium Pellet Injector SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The Lithium Pellet Injector (LPI) is being developed for the National Spherical Torus Experiment (NSTX). The LPI will inject 'pellets' of various composition into the plasma in order to study wall conditioning, edge impurity transport, liquid limiter simulations, and other areas of research. The control system for the NSTX LPI has incorporated widely used advanced technologies, such as LabVIEW(TM) and PCI bus I/O boards, to create a low-cost control system which is fully integrated into the NSTX computing environment. This paper will present the hardware and software design of the computer control system for the LPI. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Sichta, P (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 6 TC 0 Z9 0 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 409 EP 412 DI 10.1109/FUSION.2003.1426671 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700096 ER PT B AU Moses, EI AF Moses, EI GP ieee TI The national ignition facility: The world's largest laser SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest and most energetic laser experimental system, providing an international center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's 192 energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will allow the study of physical processes at temperatures approaching 10(8) K and 10(11) Bars, conditions that exist naturally only in the interior of stars, planets and in nuclear weapons. NIF has now completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilojoules of infrared light, exceeding design requirements. Operation of single beams at the second harmonic (531 nm) and third harmonic (351 nm) at greater than 10 kilojoules have also exceeded the performance criteria. NIF's target experimental systems are being commissioned and experiments have begun. This paper provides a detailed look the NIF laser systems, laser and optical performance and results from recent laser commissioning shots, and plans for commissioning diagnostics for experiments on NIF. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Moses, EI (reprint author), Lawrence Livermore Natl Lab, POB 808,L-466, Livermore, CA 94550 USA. NR 11 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 413 EP 418 DI 10.1109/FUSION.2003.1426672 PG 6 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700097 ER PT B AU Kalish, M Kozub, T Neumeyer, C Schneider, H Jurczynski, S AF Kalish, M Kozub, T Neumeyer, C Schneider, H Jurczynski, S GP ieee TI NSTX flag joint fastener design, testing, and fatigue analysis SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB In February of 2003 NSTX experienced a fault in the TF Coil system resulting in damage to the center stack TF bundle. Subsequent investigation revealed that unexpected loading of the TF Bus connections had led to failure in the "TF Flag" Bus area. Design improvements were made with respect to the TF Flag support structure and detailed analysis was performed to substantiate the new approach under both static and fatigue loading. Component and Prototype testing was used to verify the validity of the analysis. This paper briefly reviews the redesign and details the analysis and testing associated with the TF Flag Joint hardware. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kalish, M (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 462 EP 465 DI 10.1109/FUSION.2003.1426683 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700108 ER PT B AU Combs, SK Baylor, LR Foust, CR Jernigan, TC Tsai, CC AF Combs, SK Baylor, LR Foust, CR Jernigan, TC Tsai, CC GP ieee TI Experimental study of gas flow through curved tubes in support of disruption mitigation experiments in DIII-D SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc ID INJECTION; TOKAMAK AB High-pressure gas injection has been shown to be an effective disruption mitigation technique in the DIII-D tokamak, offering dramatic reductions in localized power deposition and forces to the internal components due to halo currents. To date, the gas (Ar, Ne, He, or H-2) has been injected from the magnetic low-field side of the machine through close-coupled stainless steel tubes, with relatively high gas load per shot (up to 4000 torr-L in approximate to10 ms). Another option for high-pressure gas injection in DIII-D is to utilize curved guide tubes similar to those presently used for magnetic high-field side pellet injection with exit ports on the inner wall. To demonstrate the feasibility of this option, an experimental study with different tube diameters and configurations has been carried out in the laboratory. The test results indicate that sufficiently high gas flows can be delivered through the curved guide tubes as long as the tube bore is not too restrictive (greater than or equal to7.5-mm diam). The experimental results are presented and discussed relative to the disruption mitigation experiments in DIII-D. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Combs, SK (reprint author), Oak Ridge Natl Lab, POB 2009, Oak Ridge, TN 37831 USA. NR 7 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 470 EP 473 DI 10.1109/FUSION.2003.1426685 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700110 ER PT B AU Greenough, N Wilson, JR Rosenberg, A Brunkhorst, C Depasquale, S Lafrance, D AF Greenough, N Wilson, JR Rosenberg, A Brunkhorst, C Depasquale, S Lafrance, D GP ieee TI Implementing phase feedback on the NSTX HHFW transmitters SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB A complete phase feedback system has been implemented for the High harmonic Fast Wave (HHFW) Transmitters on the National Spherical Torus Experiment. This system allows the phase of the antenna loops to be defined regardless of plasma and transmitter interaction. The system consists of two multi-channel phase detectors (presented at the 19th SOFE), high-speed RF optical links, an operator control computer running a graphical interface and a new multiple-output variable-phase oscillator presented in an adjacent paper at this conference. See "A New Phase-Feedback Digital Oscillator for HHFW Transmitters" for details of the oscillator component. This paper presents the overview and operational results of the phase feedback system that has been in service on NSTX since April 2002. To date, phase-stable operation has been achieved into all types of plasmas using both fixed and variable phase profiles during a shot. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Greenough, N (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 500 EP 503 DI 10.1109/FUSION.2003.1426693 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700118 ER PT B AU Greenough, N Lafrance, D AF Greenough, N Lafrance, D GP ieee TI A new phase-feedback digital oscillator for HHFW transmitters SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB Traditional variable-phase, multiple-output oscillators have been constructed using phase-locked loops synched to a master oscillator. Phase control is achieved by introducing a DC offset into the VCO, thus forcing the loop to compensate by shifting its phase. Such systems have limited phase shift range and often have transient locking problems leading to loss of phase control. A new variable-phase, multi-channel oscillator has been developed that directly synthesizes a variable phase output using techniques borrowed from Direct Digital Synthesis. The oscillators are under control of a simple Digital Signal Processor (DSP) that implements a phase feedback system. The present system achieves simultaneous real-time phase control of six HHFW transmitters following a pre-programmed phase profile. Future plans include real-time reaction to plasma parameters. The sample rate of the system is considerably faster than commercial "canned" solutions based on rackmount computers and graphically-programmed processes. The new oscillator is a component of a phase-feedback system for the HHFW transmitters on NSTX. See "Implementing Phase Feedback on the NSTX HHFW Transmitters" presented at this conference for a description of the complete phase-feedback system. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Greenough, N (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 504 EP 507 DI 10.1109/FUSION.2003.1426694 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700119 ER PT B AU Kung, C Greenough, N Bernabei, S Fredd, E Wilson, R Hosea, J AF Kung, C Greenough, N Bernabei, S Fredd, E Wilson, R Hosea, J GP ieee TI Improvement for lower hybrid coupler with step transformers and power dividers SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB PPPL and MIT are preparing an experiment of current profile control using Lower Hybrid waves in order to produce and sustain advanced tokamak regimes in steady state conditions in Alcator C-Mod. This new C-Mod coupler will have similar characteristics as the multijunction coupler used in other LH systems in order to obtain the full control of the phasing. This is achieved by using 3-dB vertical power splitters and a stack of laminated plates into which the waveguides are milled. Since the 3-dB vertical power splitter is in the form of the reduced height waveguide, the matching between standard WR187 waveguides and reduced height waveguides is very important in order to guarantee the power splitter performance and reduce the matching loss. 3-section quarter-wave transformers are designed for this purpose to replace the tapers in the system. Furthermore, the 3-dB vertical power splitter is redesigned with a post in the center of the coupling region, so that the splitter performance is greatly improved at the desired operating frequency. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kung, C (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 528 EP 531 DI 10.1109/FUSION.2003.1426700 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700125 ER PT B AU Kajiwara, K Lohr, J Gorelov, IA Green, MT Ponce, D Callis, RW Ellis, RA AF Kajiwara, K Lohr, J Gorelov, IA Green, MT Ponce, D Callis, RW Ellis, RA GP ieee TI Launcher performance and thermal capability of the DIII-D ECH system SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The temperatures of components of DIII-D ECH launchers were observed during 2003 tokamak operation. The injected power was typically 500-700 kW and the pulse length was typically 2 s. Plasma shots were performed at intervals of about 17 min from 9 a.m. to 5 p.m. The temperatures of a movable mirror, a fixed mirror and a launcher reached an equilibrium after about six hours of repetitive pulsing. The saturation temperature depends to some extent on the plasma stored energy. However, even in high P plasma, the temperatures plateaued at acceptable values. C1 Oak Ridge Inst Sci Educ, Oak Ridge, TN USA. RP Kajiwara, K (reprint author), Oak Ridge Inst Sci Educ, Oak Ridge, TN 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 0-7803-7908-X PY 2003 BP 538 EP 541 DI 10.1109/FUSION.2003.1426703 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700128 ER PT B AU Swain, DW Kessel, C AF Swain, DW Kessel, C GP ieee TI Heating and current drive systems for FIRE AT operation SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB FIRE is a proposed high-field tokamak (130 up to 10 T) designed to explore burning plasma physics of conventional ELMy H-modes as well as several types of advanced tokamak (AT) modes. A 20-MW ion cyclotron system in the 70 to 115 MHz frequency range is the baseline heating system. This system should achieve Q approximate to 10 in a 50:50 D-T plasma under standard (i.e., non-AT) conditions, and can also drive a modest amount of current near the center of the plasma during AT operation. Two other heating and current drive systems are being considered for FIRE as upgrade options: a 30-MW, 5-GHz lower hybrid system to drive current in the outer part of the plasma, and a 170-GHz electron cyclotron system to stabilize neoclassical tearing modes during AT operation. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Swain, DW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 BN 0-7803-7908-X PY 2003 BP 549 EP 552 DI 10.1109/FUSION.2003.1426706 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700131 ER PT B AU Brooks, A Reiersen, W AF Brooks, A Reiersen, W GP ieee TI Coil tolerance impact on plasma surface quality for NCSX SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The successful operation of the NCSX machine will require producing plasma configurations with good flux surfaces, with a minimum volume of the plasma lost to magnetic islands or stochastic regions. The project goal is to achieve good flux surfaces over 90% of the plasma volume. NCSX is a three period device designed to be operated with iota ranging from similar to 0.4 on axis to similar to0.7 at the edge. The field errors of most concern are those that are resonant with 3/5 and 3/6 modes (for symmetry preserving field errors) and the 1/2 and 2/3 modes (for symmetry breaking field errors). In addition to losses inherent in the physics configuration itself, there will be losses from field errors arising from coil construction and assembly errors. Some of these losses can be recovered through the use of trim coils or correction coils. The impact of coil tolerances on plasma surface quality is evaluated herein for the NCSX design. The methods used in this evaluation are discussed. The ability of the NCSX trim coils to correct for field errors is also examined. The results are used to set coils tolerances for the various coil systems. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Brooks, A (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 3 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 553 EP 556 DI 10.1109/FUSION.2003.1426707 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700132 ER PT B AU Zatz, IJ Chrzanowski, J Nelson, B Williamson, D Fabian, P AF Zatz, IJ Chrzanowski, J Nelson, B Williamson, D Fabian, P GP ieee TI Test program to determine the mechanical properties of the NCSX modular coils SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB The National Compact Stellarator Experiment (NCSX) is the first of a new class of stellarators known as "compact stellarators". The differentiating feature of a compact stellarator is the use of plasma current in combination with external fields to accomplish shaping and confinement. The modular coil set for NCSX is comprised of 18 complex shaped windings contained in an integral shell. There are three distinct modular coil shapes; six of each embody the complete set. To fabricate these windings to the precise shapes required, stranded copper cable conductor is wound on stainless steel winding forms. A single modular coil conductor turn is comprised of four rectangular compacted copper ropes in a two-by-two configuration which are vacuum impregnated. Groups of conductors are placed in a mold where they are bonded into bundles forming the modular coils. An in-depth mechanical test program is required to verify the integrity of the modular coil manufacturing process. This would be followed by an extensive test program, which would evaluate the vacuum impregnation of the coil and determine the thermally dependent mechanical properties of the coils. Properties to be evaluated include tension, compression, shear and flexural moduli and strengths. Thermal coefficients of expansion for various coil components are to be determined over the entire range of NCSX operating temperatures. Other specific tests, including an evaluation of resin cure shrinkage, are also planned. This paper will report the findings and results of this test program to date. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Zatz, IJ (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 557 EP 560 DI 10.1109/FUSION.2003.1426708 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700133 ER PT B AU Fan, HM Williamson, D AF Fan, HM Williamson, D GP ieee TI Engineering analyses of NCSX modular coil and its supporting structure for EM loads SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB NCSX modular coil is a major parts of the NCSX coil systems that surround the highly shaped plasma and vacuum vessel. The flexible copper cable conductors are used to form modular coil on both sides of the 'tee' beam, which is cast inside the supporting shell structure. The Engineering analyses comprise sequentially coupled-field analyses that include an electromagnetic analysis to calculate the magnetic fields and EM forces, and a structural analysis to evaluate the structural responses. In the sequential EM-structural analysis, nodal forces obtained from the EM analysis were applied as "nodal force" loads in the subsequent stress analysis using the identical nodal points and elements. The shell model was imported directly from Pro/ENGINEER files in order to obtain an accurate structural representation. The Boolean operations provided by the ANSYS preprocessor were then applied to subdivide the solid model for more desirable finite element meshing. Material properties of the modular coil were based on test results. Analyses using the ANSYS program to evaluate structural responses of the complicated modular coil systems provided a clear understanding of the structural behaviors and the directions for improving the structural design. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Fan, HM (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 1 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7908-X PY 2003 BP 565 EP 568 DI 10.1109/FUSION.2003.1426710 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700135 ER PT B AU Hatcher, RE Okabayashi, M AF Hatcher, RE Okabayashi, M GP ieee TI Field computations for DIII-D RWM stabilization coil systems SO 20TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 20th IEEE/NPSS Symposium on Fusion Engineering CY OCT 14-17, 2003 CL San Diego, CA SP IEEE, Nucl & Plasma Sci Soc AB Stabilization of the Resistive Wall Mode (RWM) is seen by fusion researchers as central to the ability to operate modern experimental devices in advanced tokamak (AT) regimes. On DIII-D first the external "C-" and now the internal "I-coil" arrays have been used in both static and dynamic RWM stabilization experiments. A suite of analysis routines was developed to analyze the magnetic fields produced by these two coil systems in realistic three-dimensional (3D) geometries. With these routines we are able to look at possible operating scenarios of the coil arrays, individually or in combination, and compare the fields produced by the coils to mode patterns from theoretical ideal-MHD calculations. These types of analyses can be an extremely valuable tool during the coil system commissioning and experiment startup process where there are uncertainties regarding installation details and connection of the various hardware components that comprise the complete system. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Hatcher, RE (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 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 0-7803-7908-X PY 2003 BP 606 EP 609 DI 10.1109/FUSION.2003.1426720 PG 4 WC Nuclear Science & Technology; Physics, Fluids & Plasmas SC Nuclear Science & Technology; Physics GA BBG17 UT WOS:000225384700145 ER PT S AU Bingham, PR Tobin, KW Bennett, MH Marmillion, P AF Bingham, PR Tobin, KW Bennett, MH Marmillion, P BE Kimmel, KR Staud, W TI Preliminary results for mask metrology using spatial heterodyne interferometry SO 23RD ANNUAL BACUS SYMPOSIUM ON PHOTOMASK TECHNOLOGY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 23rd Annual BACUS Symposium on Photomask Technology CY SEP 09-12, 2003 CL MONTEREY, CA SP BACUS, SPIE, Int Tech Grp DE mask inspection; mask metrology; spatial heterodyne interferometry AB Spatial heterodyne interferometry (SHI) is an imaging technique that captures both the phase and amplitude of a complex wavefront in a single high-speed image. This technology was developed at the Oak Ridge National Laboratory (ORNL) and is currently being implemented for semiconductor wafer inspection by nLine Corporation. As with any system that measures phase, metrology and inspection of surface structures is possible by capturing a wavefront reflected from the surface. The interpretation of surface structure heights for metrology applications can become very difficult with the many layers of various materials used on semiconductor wafers, so inspection (defect detection) has been the primary focus for semiconductor wafers. However, masks used for photolithography typically only contain a couple well-defined materials opening the doors to high-speed mask metrology in 3 dimensions in addition to inspection. Phase shift masks often contain structures etched out of the transparent substrate material for phase shifting. While these structures are difficult to inspect using only intensity, the phase and amplitude images captured with SHI can produce very good resolution of these structures. The phase images also provide depth information that is crucial for these phase shift regions. Preliminary testing has been performed to determine the feasibility of SHI for high-speed non-contact mask metrology using a prototype SHI system with 532nm wavelength illumination named the Visible Alpha Tool (VAT). These results show that prototype SHI system is capable of performing critical dimension measurements on 400nm lines with a repeatability of 1.4 nm and line height measurements with a repeatability of 0.26 nm. Additionally initial imaging of an alternating aperture phase shift mask has shown the ability of SHI to discriminate between typical phase shift heights. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bingham, PR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5143-6 J9 P SOC PHOTO-OPT INS PY 2003 VL 5256 BP 1331 EP 1342 DI 10.1117/12.518364 PN 1&2 PG 12 WC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BY41F UT WOS:000189197100143 ER PT S AU Whittle, J Saboo, J Kwan, R AF Whittle, J Saboo, J Kwan, R GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI From scenarios to code: An air traffic control case study SO 25TH INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING, PROCEEDINGS SE INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING LA English DT Proceedings Paper CT 25th International Conference on Software Engineering (ICSE 2003) CY MAY 03-10, 2003 CL PORTLAND, OR SP IEEE, IEEE Comp Soc, Tech Council Software Engn, ACM, ACM SIGSOFT, IBM, NORTHROP GRUMMAN Space Technol, BMW, NOKIA, SUN Microsyst, DaimlerChrysler, Microsoft Res ID SYSTEMS AB Two high profile workshops at OOPSLA and ICSE, an IEEE Computer article by David Harel and a growing number of research papers have all suggested algorithms that translate scenarios of a system's behavior into state machines. One of the uses of such algorithms is in the transition from requirements scenarios to component design. To date, however, most efforts have concentrated on the algorithmic details of the proposed translations. Less work has been done on evaluating these algorithms on a realistic case study. In this paper, we do exactly that for the algorithm presented in [10]. Our study is a component of an air traffic advisory system developed at NASA Ames Research Center. C1 NASA, Ames Res Ctr, QSS Grp, Ames, IA USA. RP Whittle, J (reprint author), NASA, Ames Res Ctr, QSS Grp, Ames, IA USA. NR 11 TC 12 Z9 12 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 SN 0270-5257 BN 0-7695-1877-X J9 PROC INT CONF SOFTW PY 2003 BP 490 EP 495 DI 10.1109/ICSE.2003.1201227 PG 6 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BW77V UT WOS:000183140900045 ER PT S AU Goosman, D Avara, G Wade, J Rivera, A AF Goosman, D Avara, G Wade, J Rivera, A BE Cavailler, C Haddleton, GP Hugenschmidt, M TI Optical filters to exclude non-Doppler-shifted light in fast velocimetry SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE velocimetry; filters; Doppler; Fabry-Perot AB We frequently measure velocity-time histories of dynamic experiments. In some, the Doppler-shifted light is often weak compared to non-shifted light reflected from stationary surfaces and imperfections in components. With our Fabry-Perot (FP) based systems which handle multiple frequencies, data is lost where the fringes coincide; if we had used an intensity-measuring VISAR system, it would probably fail. We designed a facility for doing experiments under such conditions by selectively eliminating most of the non-shifted light. Our first filter excluded non-shifted light by a factor of 300 when manually tuned, and by 150 when run in an auto-tuning mode. It used a single 50 mm diameter FP as the filter with a spacing of 1.65 mm and reflectivities of 77%, and filters five channels prior to use in one of our 5-beam velocimeters. One use of the filter system was to embed optical fibers in long sections of explosives to make continuous detonation velocity-time histories. We have carried out many such tests with this filter, and two without. A special single-beam filter was constructed with a 40% efficiency for shifted light that rejected non-shifted light by 4 million times, with a bandpass of a few GHz. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Goosman, D (reprint author), Lawrence Livermore Natl Lab, POB 808,L-281, Livermore, CA 94550 USA. NR 7 TC 1 Z9 1 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 152 EP 159 DI 10.1117/12.516818 PG 8 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500022 ER PT S AU Lai, CC AF Lai, CC BE Cavailler, C Haddleton, GP Hugenschmidt, M TI Electron optics design and performance of a new large-format two-frame framing tube SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE electron optics design; computer modeling; trajectory analysis; framing tube; image converter AB We have developed a framing tube with 80-mm photocathode for capturing two frames in less than 100-ns onto a 50-mm phosphor screen. A proven electron optics trajectory code was used to design the tube for imaging fidelity over wide dynamic range. This code's full accounting of space charge effects is essential for its ability to simulate accurately the distributed photoelectronic trajectories from the entire large photocathode area. Our approach and guideline for designing the electron optics are described. Results of trajectory simulation and test measurement are reported. Substantial correlations between the code expectation and the measured results are observed on relative resolution and distortion of the frame images. This tube has been integrated into an active framing camera system for field application. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lai, CC (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 5 TC 0 Z9 0 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 318 EP 323 DI 10.1117/12.516883 PG 6 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500046 ER PT S AU Lai, CC Goosman, DR Wade, JT Avara, R AF Lai, CC Goosman, DR Wade, JT Avara, R BE Cavailler, C Haddleton, GP Hugenschmidt, M TI Design and field test of a galvanometer deflected streak camera SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE streak camera; optomechanical streak camera; nanosecond streak camera; charge couple device; galvanometer scanner AB We have developed a compact fieldable optically-deflected streak camera first reported(1) in the 20-th HSPP Congress. Using a triggerable galvanometer that scans the optical signal, the imaging and streaking function is an all-optical process without incurring any photon-electron-photon conversion or pbotoelectronic deflection. As such, the achievable imaging quality is limited mainly only by optical design, rather than by multiple conversions of signal carrier and high voltage electron-optics effect. All core elements of the camera are packaged into a 12"x24" footprint box, a size similar to that of a conventional electronic streak camera. At LLNL's Site-300 Test Site, we have conducted a Fabry-Perot interferometer measurement of fast object velocity using this all-optical camera side-by-side with an intensified electronic streak camera. These two cameras are configured as two independent instruments for recording synchronously each branch of the 50/50 splits from one incoming signal. Given the same signal characteristics, the test result has undisputedly demonstrated superior imaging performance for the all-optical streak camera. It produces higher signal sensitivity, wider linear dynamic range, better spatial contrast, finer temporal resolution, and larger data capacity as compared with that of the electronic unit. The camera had also demonstrated its structural robustness and functional consistence to be well compatible with field environment. This paper presents the camera design and the test results in both pictorial records and post-process graphic summaries. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lai, CC (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 2 TC 11 Z9 11 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 330 EP 335 DI 10.1117/12.516886 PG 6 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500048 ER PT S AU King, NSP Baker, S Jaramillo, S Kwiatkowski, K Lutz, S Hogan, GE Homes, V Morris, CL Nedrow, P Pazuchanics, PD Rohrer, J Sorenson, D Thompson, R AF King, NSP Baker, S Jaramillo, S Kwiatkowski, K Lutz, S Hogan, GE Homes, V Morris, CL Nedrow, P Pazuchanics, PD Rohrer, J Sorenson, D Thompson, R BE Cavailler, C Haddleton, GP Hugenschmidt, M TI Imaging detector systems for soft X-ray and proton radiography SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE electro-optic shuttering; radiography AB Multi-pulse imaging systems have been developed for recording images from pulsed X-ray and proton radiographic sources. The number of successive images for x-ray radiography is limited to four being generated by 25ns, pulsed sources in a close positioned geometry. The number of proton images are provided by the number of proton bursts (similar to60ns) delivered to the radiographic system. In both cases the radiation to light converter is a thin LSO crystal. The radiographic image formed is relayed by a direct, coherent bundle or lens coupling to a variety of electronic shuttered, cooled CCD cameras. The X-ray system is optimized for detecting bremmstrahlung, reflection geometry generated X-rays with end point energies below 300keV. This has resulted in less than 200mum thick LSO converters which are 25x25mm(2). The converter is attached to a UV transmitting fiberoptic which in turn is directly coupled to a coherent bundle. The image is relayed to a 25mm microchannel plate image intensifier attached to a 4 image framing camera. The framing camera image is recorded by a 1600x1600 pixel, cooled CCD camera. The current proton radiography imaging system for dynamic experiments is based on a system of seven individual high-resolution CCD cameras, each with its own optical relay and fast shuttering. The image of the radiographed object is formed on a 1.7mm thick tiles of LSO scintillator. The rapid shuttering for each of the CCD's is accomplished via proximity-focussed planar diodes (PPD), which require application of 300-to-500 ns long, 12kV pulses to the PPD from a dedicated HV pulser. The diodes are fiber-optically coupled to the front face of the CCD chips. For each time-frame a separate CCD assembly is required. The detection quantum efficiency (DQE) of the system is about 0.4. This is due to the lens coupling inefficiency, the necessary demagnification (typically between 5:1 and 3: 1) in the system optics, and the planar-diode photo-cathode quantum efficiency (QE) (of similar to15%). More recently, we have incorporated a series of 4,or 9 image framing cameras to provide an increased number of images. These have been coupled to cooled CCD cameras as readouts. A detailed description of the x-ray and proton radiographic imaging systems are discussed as well as observed limitations in performance. A number of improvements are also being developed which will be described. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP King, NSP (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 7 TC 5 Z9 5 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 610 EP 615 DI 10.1117/12.516915 PG 6 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500087 ER PT S AU Kwiatkowski, K King, NSP Lyke, J Beche, JF Hogan, GE Kapusta, C Millaud, JE Morris, C Wojnarowski, R AF Kwiatkowski, K King, NSP Lyke, J Beche, JF Hogan, GE Kapusta, C Millaud, JE Morris, C Wojnarowski, R BE Cavailler, C Haddleton, GP Hugenschmidt, M TI Development of a multi-frame optical Imaging detector for proton radiography at LANL SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE proton radiography; fast visible imagers; hybrid detectors; 3D packaging; ultra dense interconnect AB In this paper we give a brief report on the development of simple direct- and indirect-detection imagers for proton radiography experiments. We outline a conceptual design for a novel, multi-frame 5 mega frames per second (Mfs) hybrid imager. The high-density interconnect is identified as a critical enabling technology. We present a description of a 3D electronics packaging cube, which was completed in a recent feasibility study. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Kwiatkowski, K (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 5 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 616 EP 621 DI 10.1117/12.516916 PG 6 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500088 ER PT S AU Multhauf, LG Back, NL Simmons, LF Zentler, JM Scarpetti, RD AF Multhauf, LG Back, NL Simmons, LF Zentler, JM Scarpetti, RD BE Cavailler, C Haddleton, GP Hugenschmidt, M TI The LLNL flash X-ray induction linear accelerator (FXR) SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE FXR; CFF; LIA; contained firing facility; linear induction accelerator; gamma-ray camera AB The FXR is an induction linear accelerator used for high-speed radiography at the Lawrence Livermore National Laboratory's Experimental Test Site. It was designed specifically for the radiography of very thick explosive objects. Since its completion in 1982, it has been very actively used for a large variety of explosives tests, and has been periodically upgraded to achieve higher performance. Upgrades have addressed machine reliability, radiographic sensitivity and resolution, two-frame imaging by double pulsing-improvements that are described in detail in the paper. At the same time, the facility in which it was installed has also been extensively upgraded, first by adding space for optical and interferometric diagnostics, and more recently by adding a containment chamber to prevent the environmental dispersal of hazardous and radioactive materials. The containment addition also further expands space for new non-radiographic diagnostics. The new Contained Firing Facility is still in the process of activation. At the same time, FXR is continuing to undergo modifications aimed primarily at further increasing radiographic resolution and sensitivity, and at improving double-pulsed performance. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Multhauf, LG (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 622 EP 633 DI 10.1117/12.516922 PG 12 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500089 ER PT S AU Stigman, WL Kihara, R Scarpetti, RD AF Stigman, WL Kihara, R Scarpetti, RD BE Cavailler, C Haddleton, GP Hugenschmidt, M TI An electronic flash lamp system to replace the traditional, explosively - Driven light source SO 25TH INTERNATIONAL CONGRESS ON HIGH-SPEED PHOTOGRAPHY AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 25th International Congress on High-Speed Photography and Photonics CY SEP 29-OCT 04, 2002 CL BEAUNE, FRANCE SP nac Image Technol, Photron (Europe) Ltd, Photo Son Int Ltd, Vis Res Inc DE flash lamps; light sources; rotating mirror cameras; explosives; illumination; high-speed photography AB Electronic flash lamps are being developed at the Lawrence Livermore National Laboratory (LLNL). These lamps are intended to replace the traditional explosively driven Argon-gas filled light sources (Argon candles) that are currently used to provide illumination for high speed rotating mirror-framing cameras. At Livermore, we are developing an electronic flash lamp system that can match or exceed the light output of a traditional Argon candle. These systems utilize a Plasma Arc Lamp(1,2) developed by PRISM Science Inc of Woburn, MA, USA. In the past, high-speed photography requiring explosively driven light sources were a one-time-only event that destroyed fixtures and optical alignment. The electronic flash lamp system, utilizing the Plasma Arc Lamp, will replace the explosively driven lighting systems and provide the capability to dry run experimental setups and repeat tests without damage to the experimental set-up. The electronic flash lamp system eliminates the problem of collateral damage to the experiment and does not add to the overall amount of explosives needed for a single test. Since the Pulsed-Power driver is remotely located, only the flash lamp itself is destroyed when the explosive shot is fired. The flexible geometry of this light source also enables the user to create complex light patterns as well as photograph very large areas with a single lighting system. This electronic flash lamp system will provide an extremely bright, stable, and repeatable light source for rotating-mirror framing cameras operating at one million frames per second, using both black & white or color films. The design of the Pulsed-Power driver and the flash lamp, along with experimental data and results will be discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Stigman, WL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4744-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4948 BP 806 EP 810 DI 10.1117/12.516985 PG 5 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BX38E UT WOS:000185090500117 ER PT B AU Dorow, K AF Dorow, K GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Flexible fault tolerance in configurable middleware for embedded systems SO 27TH ANNUAL INTERNATIONAL COMPUTER SOFTWARE AND APPLICATIONS CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 27th Annual International Computer Software and Applications Conference CY NOV 03-06, 2003 CL DALLAS, TX SP IEEE Comp Soc AB MicroQoSCORBA (MQC) is a middleware platform that focuses on embedded applications by providing a very fine level of configurability of its internal orthogonal components. Using this configurability, a developer can generate a customized middleware instantiation that is tailored to both the requirements and constraints of a specific embedded application and the embedded hardware. One of the key components provided by MQC is a set of fault-tolerant mechanisms, which allow for support of applications that require a higher level of reliability. This document provides a detailed description of the algorithms and protocols selected for these mechanisms, along with a discussion of their implementation and incorporation into the MQC platform. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Dorow, K (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 7 TC 2 Z9 2 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 0-7695-2020-0 PY 2003 BP 563 EP 569 DI 10.1109/CMPSAC.2003.1245396 PG 7 WC Computer Science, Information Systems; Computer Science, Software Engineering SC Computer Science GA BX93S UT WOS:000186891300082 ER PT B AU Gorton, I Thurman, D Thomson, J AF Gorton, I Thurman, D Thomson, J GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Next generation application integration: Challenges and new approaches SO 27TH ANNUAL INTERNATIONAL COMPUTER SOFTWARE AND APPLICATIONS CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 27th Annual International Computer Software and Applications Conference CY NOV 03-06, 2003 CL DALLAS, TX SP IEEE Comp Soc AB integrating multiple heterogeneous data sources into applications is a time-consuming, costly and error-prone engineering task. Relatively mature technologies exist that make integration tractable from an engineering perspective. These technologies, however, have many limitations, and hence present opportunities for breakthrough research. This paper briefly describes some of these limitations, and enumerates a subset of the general open research problems. It then describes the Data Concierge research project and prototype that is attempting to provide solutions to some of these problems. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gorton, I (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Gorton, Ian/A-8247-2009 NR 8 TC 1 Z9 1 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 0-7695-2020-0 PY 2003 BP 576 EP 581 DI 10.1109/CMPSAC.2003.1245398 PG 6 WC Computer Science, Information Systems; Computer Science, Software Engineering SC Computer Science GA BX93S UT WOS:000186891300084 ER PT S AU Radovic, M Lara-Curzio, E Armstrong, B Walls, C AF Radovic, M Lara-Curzio, E Armstrong, B Walls, C BE Kriven, WM Lin, HT TI Effect of thickness and porosity on the mechanical properties of planar components for solid oxide fuel cells at ambient and elevated temperatures SO 27TH INTERNATIONAL COCOA BEACH CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 27th International Cocoa Beach Conference on Advanced Ceramics Composites CY JAN 26-31, 2003 CL COCOA BEACH, FL SP Amer Ceram Soc AB The effects of specimen thickness and porosity on the elastic moduli, equibiaxial strength, and fracture toughness of planar solid oxide fuel cell components are reported. The tested materials include 8mol% yttria-stabilized zirconia (YSZ) electrolytes, and unreduced NiO/YSZ anodes. The thickness of these components varied between 0.5 and 1.5 mm, while the porosity varied between 6 and 23 % vol. Test specimens were processed by tape casting techniques and inspected by Infrared Imaging and Resonant Ultrasound Spectroscopy (RUS). These non-destructive evaluation techniques revealed the existence of defects, such as delamination. The equibiaxial flexural strength was determined by the ring-on-ring test method (ASTM C1499) while the fracture toughness was determined according to the double-torsion test method. Tests were carried out at ambient and elevated temperatures in air. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Radovic, M (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Armstrong, Beth/E-6752-2017 OI Armstrong, Beth/0000-0001-7149-3576 NR 9 TC 4 Z9 4 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 2003 VL 24 IS 3 BP 329 EP 334 PG 6 WC Electrochemistry; Materials Science, Ceramics; Materials Science, Biomaterials; Materials Science, Characterization & Testing; Materials Science, Composites SC Electrochemistry; Materials Science GA BY46D UT WOS:000189318200050 ER PT S AU Tiegs, TN Kiggans, JO Montgomery, FC Harper, DC Blue, CA AF Tiegs, TN Kiggans, JO Montgomery, FC Harper, DC Blue, CA BE Kriven, WM Lin, HT TI Surface modification of ceramics by high density infrared heating SO 27TH INTERNATIONAL COCOA BEACH CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 27th International Cocoa Beach Conference on Advanced Ceramics Composites CY JAN 26-31, 2003 CL COCOA BEACH, FL SP Amer Ceram Soc AB High density infrared (HDI) heating offers a unique method for surface modification. The technique was used to surface treat commercial high alumina refractories where surface melting was observed. During solidification of the surface melted region, highly oriented mullite grains with the c-axis perpendicular to the surface were precipitated. Preliminary corrosion testing with molten copper showed less penetration into the HDI treated materials. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tiegs, TN (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 2003 VL 24 IS 3 BP 477 EP 482 PG 6 WC Electrochemistry; Materials Science, Ceramics; Materials Science, Biomaterials; Materials Science, Characterization & Testing; Materials Science, Composites SC Electrochemistry; Materials Science GA BY46D UT WOS:000189318200068 ER PT S AU Kiggans, JO Montgomery, FC Tiegs, TN Evans, BM AF Kiggans, JO Montgomery, FC Tiegs, TN Evans, BM BE Kriven, WM Lin, HT TI Low temperature sintering of Pb(ZrTi)O-3 materials for actuator applications SO 27TH INTERNATIONAL COCOA BEACH CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 27th International Cocoa Beach Conference on Advanced Ceramics Composites CY JAN 26-31, 2003 CL COCOA BEACH, FL SP Amer Ceram Soc ID PIEZOELECTRIC CERAMICS AB A goal in manufacturing multilayer lead zirconium titanate (PZT) actuators is to produce materials that can be sintered at temperatures <960degreesC so that the internal electrodes can be constructed from more cost-effective Ag alloys. A commercial PZT-4 type powder was modified by the addition of glass forming donor and acceptor compounds. Powder mixtures were milled using standard ball milling or high-energy attrition milling steps. Both pressed and tape cast laminate discs were fabricated from the powders and then sintered at 800degreesC to 950degreesC in air. The mechanical properties and electromechanical properties of the sintered materials were measured. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Kiggans, JO (reprint author), Oak Ridge Natl Lab, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 7 TC 0 Z9 0 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 2003 VL 24 IS 4 BP 35 EP 40 PG 6 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BY46E UT WOS:000189318400006 ER PT S AU Sun, JG Erdman, S Connolly, L AF Sun, JG Erdman, S Connolly, L BE Kriven, WM Lin, HT TI Measurement of delamination size and depth in ceramic matrix composites using pulsed thermal imaging SO 27TH INTERNATIONAL COCOA BEACH CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 27th International Cocoa Beach Conference on Advanced Ceramics Composites CY JAN 26-31, 2003 CL COCOA BEACH, FL SP Amer Ceram Soc AB A pulsed thermal imaging (PTI) method was developed to determine the size and depth of delaminations in ceramic matrix composites (CMCs). In this method, pulsed heat energy is applied to the surface of a sample, and the decay of the surface temperature is then measured and analyzed to produce a depth image of the sample. The sensitivity and accuracy of the PTI method were determined from experiments using a melt-infiltrated CMC sample with drilled flat-bottom holes at the back surface to serve as "delaminations". A 3-D transient-heat-transfer code was used to simulate the experimental heat transfer process within the samples and to determine the optimal sensitivity for delamination detection by the PTI method. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Sun, JG (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 5 Z9 7 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 2003 VL 24 IS 4 BP 201 EP 206 PG 6 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BY46E UT WOS:000189318400030 ER PT S AU Jones, RH AF Jones, RH BE Kriven, WM Lin, HT TI SiCf/SiC composites for advanced nuclear applications SO 27TH INTERNATIONAL COCOA BEACH CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 27th International Cocoa Beach Conference on Advanced Ceramics Composites CY JAN 26-31, 2003 CL COCOA BEACH, FL SP Amer Ceram Soc AB Composite materials have the potential for their properties to be tailored to specific applications by engineering the combination of fibers and matrices. Ceramic matrix composites are attractive because of their excellent high-temperature properties and corrosion resistance. In particular, ceramic composites made from silicon carbide fibers and silicon carbide matrices (SiCf/SiC) are promising for nuclear applications because of the radiation resistance of the beta-phase of SiC, their excellent high-temperature fracture, creep, corrosion and thermal shock resistance. The beta-phase of SiC has been shown by numerous studies to have a: saturation swelling value of about 0.1 to 0.2% at 800 to 1000degreesC. This suggests that composites of SiC/SiC have the potential for excellent radiation stability. The continuous fiber architecture, coupled with engineered interfaces between the fiber and matrix, provide excellent fracture properties and fracture toughness values on the order of 25 MPa m(1/2). The strength and fracture toughness are independent of temperature up to the limit of the fiber stability. Also, these fiber/matrix microstructures impart excellent thermal shock and thermal fatigue resistance so start-up and shut-down cycles and coolant loss scenarios should not induce significant structural damage. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Jones, RH (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 6 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 2003 VL 24 IS 4 BP 261 EP 267 PG 7 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BY46E UT WOS:000189318400038 ER PT S AU Hinoki, T Lara-Curzio, E Snead, LL AF Hinoki, T Lara-Curzio, E Snead, LL BE Kriven, WM Lin, HT TI Evaluation of transthickness tensile strength of SiC/SiC composites SO 27TH INTERNATIONAL COCOA BEACH CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 27th International Cocoa Beach Conference on Advanced Ceramics Composites CY JAN 26-31, 2003 CL COCOA BEACH, FL SP Amer Ceram Soc ID FIBER; GLASS AB The transthickness tensile strength (TTS) of 2-D CVI-SiC/SiC composites reinforced with Tyranno SA fibers was evaluated by the diametral compression test. The effect of specimen size and specimen shape on the magnitude of the TTS were studied and the results were analyzed using Weibull statistics. Specimens failed along an interlaminar plane adjacent to the line of action of the applied load and fractographic analyses revealed that the crack had propagated through matrix pores and along interfaces between the fiber, fiber coating and matrix. The magnitude of the TTS was found to be independent of specimen size or shape for the range of specimen dimensions investigated, although the amount of scatter was largest for the results obtained from the evaluation of the smallest specimens. The characteristic value of the TTS and the Weibull modulus for the distribution of TTS values were 24.9 MPa and 6.48, respectively. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hinoki, T (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 2003 VL 24 IS 4 BP 401 EP 406 PG 6 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BY46E UT WOS:000189318400058 ER PT B AU Ellingson, RJ Blackburn, JL Nedeljkovic, J Rumbles, G Jones, M Fu, H Nozik, AJ AF Ellingson, RJ Blackburn, JL Nedeljkovic, J Rumbles, G Jones, M Fu, H Nozik, AJ BE Stutzmann, M TI Experimental and theoretical investigation of electronic structure in colloidal indium phosphide quantum dots SO 2ND INTERNATIONAL CONFERENCE ON SEMICONDUCTOR QUANTUM DOTS LA English DT Proceedings Paper CT 2nd International Conference on Semiconductor Quantum Dots CY SEP 30-OCT 03, 2002 CL UNIV TOKYO, KOMABA CAMPUS, TOKYO, JAPAN HO UNIV TOKYO, KOMABA CAMPUS ID INP; RELAXATION; EXCITONS AB We present detailed electronic structure calculations, based on an atomistic pseudopotential approach, for a 42 Angstrom InP QD; theoretical results are correlated to results of experimental measurements. To better understand energy loss dynamics and mechanisms for hot carriers in QDs, we investigate relaxation between electronic levels in InP QDs with diameters significantly smaller than twice the Bohr exciton radius. Energy level spacings exceeding the optical phonon energy present the opportunity for slowed charge carrier cooling (phonon bottleneck effect). However, interaction between confined electrons and holes provides an alternate, efficient relaxation route. Therefore, we expect sufficiently fast charge separation to weaken the Coulomb interaction and decrease the electronic energy loss rate. We study electronic relaxation in InP QDs using variations of subpicosecond transient absorption spectroscopy. C1 Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RP Ellingson, RJ (reprint author), Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RI Ellingson, Randy/H-3424-2013; OI Rumbles, Garry/0000-0003-0776-1462 NR 13 TC 2 Z9 2 U1 1 U2 4 PU WILEY-VCH, INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA BN 3-527-40464-3 PY 2003 BP 1229 EP 1232 DI 10.1002/pssc.200303100 PG 4 WC Physics, Condensed Matter SC Physics GA BX68D UT WOS:000186108000035 ER PT B AU Michael, P Miller, M AF Michael, P Miller, M GP AMS TI Cloud detection using radar wind profiler output SO 31ST CONFERENCE ON RADAR METEOROLOGY, VOLS 1 AND 2 LA English DT Proceedings Paper CT 31st Conference on Radar Meteorology CY AUG 06-12, 2003 CL Seattle, WA SP Amer Meteorol Soc ID RADIATION MEASUREMENT PROGRAM; ATMOSPHERIC RADIATION C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Michael, P (reprint author), Brookhaven Natl Lab, Bldg 490D, Upton, NY 11973 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2003 BP 1000 EP 1003 PG 4 WC Meteorology & Atmospheric Sciences; Physics, Applied SC Meteorology & Atmospheric Sciences; Physics GA BAT17 UT WOS:000223421300289 ER PT S AU Barrett, CL Marathe, MV Engelhart, DC Sivasubramaniam, A AF Barrett, CL Marathe, MV Engelhart, DC Sivasubramaniam, A BE Bilof, R TI Approximate connectivity graph generation in mobile ad hoc radio networks SO 36TH ANNUAL SIMULATION SYMPOSIUM, PROCEEDINGS SE PROCEEDINGS OF THE ANNUAL SIMULATION SYMPOSIA LA English DT Proceedings Paper CT 36th Annual Simulation Symposium CY MAR 30-APR 02, 2003 CL ORLANDO, FL SP Soc Modeling & Simulat Int AB Simulation is a widely used technique in the design and evaluation of mobile ad-hoc networks. However time and space constraints can often limit the extent of the size, complexity and detail of the networks that can be simulated. Approximations in the system model can possibly alleviate this problem, but we need to be careful about how much accuracy is compromised when employing them. This paper specifically focuses on one aspect of simulation cost that is incurred in the computation of the connectivity graph that is used to describe what mobile nodes can communicate with whom. Since such a graph is recomputed frequently during the simulation, we explore alternatives to computing this graph exactly and their accuracy in capturing the actual graph properties. We investigate three approximation alternatives to compute graph connectivity, and propose metrics for expressing their deviations from the actual graph. In addition, the graphs generated by these approximations are compared to the original by examining two previously proposed graph measures - the degree and clustering coefficient distributions. Results indicate that these approximations can be quite effective in avoiding repeated calculation of exact graph connectivity. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Barrett, CL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 11 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 SN 1080-241X BN 0-7695-1911-3 J9 PROC ANNU SIMUL SYMP PY 2003 BP 81 EP 88 DI 10.1109/SIMSYM.2003.1192801 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BW53X UT WOS:000182322600010 ER PT S AU Holmes, VP Johnson, WR Miller, DJ AF Holmes, VP Johnson, WR Miller, DJ BE Bilof, R TI Integrating web service and grid enabling technologies to provide desktop access to high-performance cluster-based components for large-scale data services SO 36TH ANNUAL SIMULATION SYMPOSIUM, PROCEEDINGS SE PROCEEDINGS OF THE ANNUAL SIMULATION SYMPOSIA LA English DT Proceedings Paper CT 36th Annual Simulation Symposium CY MAR 30-APR 02, 2003 CL ORLANDO, FL SP Soc Modeling & Simulat Int AB At Sandia National Laboratories, a Data Services system is under development to provide web-based access to high-performance computing clusters. These clusters host a set of scalable post-processing applications for very large data manipulation and visualization of results generated by large-scale simulations in support of the design to analysis process for ensuring safety and reliability of the nation's nuclear weapons stockpile. The primary contribution of this work is the integration of standards-based web services technologies, grid-enabling software, and a component framework for parallel computing, resulting in a service-oriented architecture which provides end users the ability from their desktops to manage and understand simulation results for very large, complex problems. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Holmes, VP (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 6 Z9 6 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 SN 1080-241X BN 0-7695-1911-3 J9 PROC ANNU SIMUL SYMP PY 2003 BP 167 EP 174 DI 10.1109/SIMSYM.2003.1192810 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BW53X UT WOS:000182322600019 ER PT B AU Tarver, EE AF Tarver, EE BE Sanson, LD TI External second gate Fourier transform ion mobility spectrometry: Parametric optimization for detection of weapons of mass destruction SO 37TH ANNUAL 2003 INTERNATIONAL CARNAHAN CONFERENCE ON SECURITY TECHNOLOGY, PROCEEDINGS LA English DT Proceedings Paper CT 37th Annual International Carnahan Conference on Security Technology CY OCT 14-16, 2003 CL Taipei, TAIWAN SP IEEE Lexington Sect, IEEE Aerosp & Elect Syst Soc, Chung Shan Inst Sci & Technol, USA Res Lab, Far E Res Off Aerosp, Res & Dev, IEEE Taipei Sect, Natl Cent Univ, Chinese Inst Elect Engn DE signal averaging; entrance gate; exit gate; interferogram; Fourier transform AB Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and robust techniques for the detection of narcotics, explosives and chemical warfare agents. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention treaty verification as well as humanitarian de-mining efforts have mandated that equal importance be placed on the analysis time as well as the quality of the analytical data. ((1)) IMS unrivaled when both speed of response and sensitivity have to be considered. ((2)) The problem with conventional (signal averaging) IMS systems is the fixed duty cycle of the entrance gate that restricts to less than 1%, the number of available ions contributing to the measured signal. Furthermore, the signal averaging process incorporates scan-to-scan variations that degrade the spectral resolution. With external second gate Fourier Transform ion mobility spectrometry (FT-IMS), the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters to increase the spectral resolution. In addition, with FT-IMS the entrance gate operates with a 50% duty cycle and so affords a 7-10 fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system. C1 Sandia Natl Labs, Analyt Mat Sci Dept, Livermore, CA 94551 USA. RP Tarver, EE (reprint author), Sandia Natl Labs, Analyt Mat Sci Dept, POB 969, Livermore, CA 94551 USA. NR 8 TC 1 Z9 1 U1 2 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7882-2 PY 2003 BP 515 EP 522 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA BAC95 UT WOS:000221608800086 ER PT B AU Tucker, BJ AF Tucker, BJ BE Tichy, RJ Yadama, V TI Using antisymmetric ultrasonic plate waves to determine flexural and transverse shear properties in wood composite panels SO 37th International Wood Composite Materials Symposium Proceedings LA English DT Proceedings Paper CT 37th International Wood Composite Materials Symposium CY APR 08-10, 2003 CL Washington State Univ, Pullman, WA SP Washington State Univ, Coll Engn & Architecture, Wood Mat & Engn Lab, WSU Extension HO Washington State Univ C1 Pacific NW Natl Lab, Natl Secur Directorate, Richland, WA USA. RP Tucker, BJ (reprint author), Pacific NW Natl Lab, Natl Secur Directorate, Richland, WA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WASHINGTON STATE UNIV ENGINEERING EXTENSION SERVICE PI PULLMAN PA DANA HALL, PULLMAN, WA 99164 USA PY 2003 BP 153 EP 153 PG 1 WC Materials Science, Paper & Wood; Materials Science, Composites SC Materials Science GA BCR40 UT WOS:000230914100030 ER PT B AU Bazan, G Dearborn, DSP Dossa, DD Eggleton, PP Taylor, A Castor, JI Murray, S Cook, KH Eltgroth, PG Cavallo, RM Turcotte, S Keller, SC Pudliner, BS AF Bazan, G Dearborn, DSP Dossa, DD Eggleton, PP Taylor, A Castor, JI Murray, S Cook, KH Eltgroth, PG Cavallo, RM Turcotte, S Keller, SC Pudliner, BS BE Turcotte, S Keller, SC Cavallo, RM TI Djehuty, a code for modeling stars in three dimensions SO 3D STELLAR EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3D Stellar Evolution Workshop CY JUL 22-26, 2002 CL UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA HO UNIV CALIF DAVIS, DEPT APPL SCI ID TURBULENT COMPRESSIBLE CONVECTION; NEUTRINO ENERGY-LOSS; DIFFERENTIAL ROTATION; STELLAR INTERIORS; SIMULATIONS; OPACITIES; EVOLUTION; PLASMA; FLOW AB Current practice in stellar evolution is to employ one-dimensional calculations that quantitatively apply only to a minority of the observed stars (single non-rotating stars, or well detached binaries). Even in these systems, astrophysicists are dependent on approximations to handle complex three-dimensional processes like convection. Understanding the structure of binary stars, like those that lead to the Type la supernovae used to measure the expansion of the universe, are grossly non-spherical and await a 3D treatment. To approach very large problems like multi-dimensional modeling of stars, the Lawrence Livermore National Laboratory has invested in massively parallel computers and invested even more in developing the algorithms to utilize them on complex physics problems. We have leveraged skills from across the lab to develop a 3D stellar evolution code, Djehuty (after the Egyptian god for writing and calculation) that operates efficiently on platforms with thousands of nodes, with the best available physical data (opacities, EOS, etc.). Djehuty has incorporated all basic physics for modeling stars including an accurate equation of state, radiation transport by diffusion, thermonuclear reaction rates, and hydrodynamics, and we have begun testing it in a number of applications. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bazan, G (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Murray, Stephen/I-8685-2016 OI Murray, Stephen/0000-0001-5597-090X NR 20 TC 16 Z9 16 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-140-0 J9 ASTR SOC P PY 2003 VL 293 BP 1 EP 14 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW96Q UT WOS:000183791600001 ER PT B AU Eggleton, PP Bazan, G Cavallo, AM Dearborn, DSP Dossa, DD Keller, SC Taylor, AG Turcotte, S AF Eggleton, PP Bazan, G Cavallo, AM Dearborn, DSP Dossa, DD Keller, SC Taylor, AG Turcotte, S BE Turcotte, S Keller, SC Cavallo, RM TI Prospects for Djehuty SO 3D STELLAR EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3D Stellar Evolution Workshop CY JUL 22-26, 2002 CL UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA HO UNIV CALIF DAVIS, DEPT APPL SCI ID STELLAR EVOLUTION; STARS AB The Djehuty project at Lawrence Livermore National Laboratory is planning to tackle a great variety of stellar-structural problems with a 3-D hydrodynamic and thermodynamic code. We plan to evolve entire stars, including all the major physical processes in a realistic manner. The project is in its early stages, but we describe a few preliminary results, and discuss our aims for the future. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Eggleton, PP (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-140-0 J9 ASTR SOC P PY 2003 VL 293 BP 15 EP 21 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW96Q UT WOS:000183791600002 ER PT B AU Cohl, HS AF Cohl, HS BE Turcotte, S Keller, SC Cavallo, RM TI Portent of Heine's reciprocal square root identity SO 3D STELLAR EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3D Stellar Evolution Workshop CY JUL 22-26, 2002 CL UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA HO UNIV CALIF DAVIS, DEPT APPL SCI AB Precise efforts in theoretical astrophysics are needed to fully understand the mechanisms that govern the structure, stability, dynamics, formation, and evolution of differentially rotating stars. Direct computation of the physical attributes of a star can be facilitated by the use of highly compact azimuthal and separation angle Fourier formulations of the Green's functions for the linear partial differential equations of mathematical physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Cohl, HS (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-140-0 J9 ASTR SOC P PY 2003 VL 293 BP 70 EP 75 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW96Q UT WOS:000183791600009 ER PT B AU Keller, SC Wood, PR AF Keller, SC Wood, PR BE Turcotte, S Keller, SC Cavallo, RM TI Bump cepheids and the stellar mass-luminosity relation SO 3D STELLAR EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3D Stellar Evolution Workshop CY JUL 22-26, 2002 CL UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA HO UNIV CALIF DAVIS, DEPT APPL SCI ID CLUSTERS AB We present the results of non-linear pulsation modeling of bump Cepheids in the LMC and SMC. By obtaining an optimal fit to the observed MACHO V and R lightcurves we can determine the fundamental parameters of each Cepheid, namely mass, luminosity, effective temperature, distance modulus and reddening. We are able to describe the mass-luminosity relation for core-He burning intermediate mass stars. The mass-luminosity relation depends critically upon the level of internal mixing during the course of the star's main-sequence evolution. Under the paradigm of convective core overshoot, our results enable us to place tight quantitative limits of the level of overshoot. We derive an overshooting paxameter of Lambda(c) of 0.65+/-0.03 and 0.67+/-0.04 l/H-p for the LMC and SMC respectively. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Keller, SC (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, POB 5508, Livermore, CA 94550 USA. NR 5 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 1-58381-140-0 J9 ASTR SOC P PY 2003 VL 293 BP 285 EP 289 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW96Q UT WOS:000183791600032 ER PT B AU Hurricane, OA Fong, BHL Cowley, SC AF Hurricane, OA Fong, BHL Cowley, SC BE Turcotte, S Keller, SC Cavallo, RM TI Explosive instability of prominence flux ropes SO 3D STELLAR EVOLUTION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3D Stellar Evolution Workshop CY JUL 22-26, 2002 CL UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA HO UNIV CALIF DAVIS, DEPT APPL SCI ID KINK INSTABILITY; DETONATION AB The rapid, Alfvenic, time scale of erupting solar-prominences has been an enigma ever since they where first identified. Investigators have proposed a variety of different mechanisms in an effort to account for the abrupt reconfiguration observed. No one mechanism clearly stands out as the single cause of these explosive events. Recent analysis has demonstrated that field lines in the solar atmosphere are metastable to ballooning type instabilities. It has been found previously that in ideal MHD plasmas marginally unstable ballooning modes inevitably become "explosive" evolving towards a finite time singularity via a nonlinear 3D instability called "Nonlinear Magnetohydrodynamic Detonation." Thus, this mechanism is a good candidate to explain explosive events observed in the solar atmosphere of our star or in others. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Hurricane, OA (reprint author), Lawrence Livermore Natl Lab, POB 808,L-22, Livermore, CA 94551 USA. NR 12 TC 0 Z9 0 U1 1 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-140-0 J9 ASTR SOC P PY 2003 VL 293 BP 306 EP 313 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW96Q UT WOS:000183791600035 ER PT B AU Dodd, PE Shaneyfelt, MR Schwank, JR Hash, GL AF Dodd, PE Shaneyfelt, MR Schwank, JR Hash, GL GP IEEE IEEE TI Neutron-induced latchup in SRAMs at ground level SO 41ST ANNUAL PROCEEDINGS: INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM SE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM LA English DT Proceedings Paper CT 41st Annual IEEE International Reliability Physics Symposium CY MAR 30-APR 04, 2003 CL DALLAS, TX SP IEEE Electr Devices Soc, IEEE Reliabil Soc ID RADIATION-INDUCED LATCHUP; INDUCED SOFT ERRORS; COSMIC-RAYS; ELECTRONICS; MEMORIES; SPACE AB Neutron-induced single-event latchup has been studied in SRAMs manufactured by several different vendors. These SRAMs span different cell designs (six-transistor and four-transistor cells), technology generations (0.25 mum to 0.14 mum) and power supplies (5 V to 1.5 V). While some technologies appear to be latchup-free in neutron environments, others have neutron-induced latchup failure-in-time, (FIT) rates as high as 300 FIT/Mbit at room temperature and maximum rated voltage. Latchup FIT rates increase dramatically with temperature. The observed latchup, rates can lead to very high failure rates in. systems with large amounts of memory, and can't be circumvented using terror correction. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dodd, PE (reprint author), Sandia Natl Labs, POB 5800,MS-1083, Albuquerque, NM 87185 USA. NR 21 TC 14 Z9 15 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7649-8 J9 INT REL PHY PY 2003 BP 51 EP 55 DI 10.1109/RELPHY.2003.1197720 PG 5 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BW53W UT WOS:000182322300010 ER PT B AU Tanner, DM Swanson, SE Walraven, JA Dohner, JL AF Tanner, DM Swanson, SE Walraven, JA Dohner, JL GP IEEE IEEE TI On-chip monitoring of MEMS gear motion SO 41ST ANNUAL PROCEEDINGS: INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM SE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM LA English DT Proceedings Paper CT 41st Annual IEEE International Reliability Physics Symposium CY MAR 30-APR 04, 2003 CL DALLAS, TX SP IEEE Electr Devices Soc, IEEE Reliabil Soc ID OXIDATION AB We have designed and fabricated a polysilicon sidewall-contact motion monitor that fits in between the teeth of a MEMS gear. The monitor has a center grounded member that is moved into contact with a pad held at voltage. We have succeeded in observing motion, however, the monitor fails after only a few actuations. A thorough investigation of the contacting interfaces revealed that for voltages > 5 V with a current limit of 100 muA, the main conduction process is Fowler-Nordheim tunneling. After a few switch cycles, the polysilicon interfaces became insulating. This is shown to be a permanent change and the suspected mechanism is field-induced oxidation of the asperity contacts. To reduce the effects of field-induced oxidation, tests were performed at 0.5 V and no permanent insulating case was observed. However, the position of the two contacting surfaces produced three types of conduction processes a) Fowler-Nordheim tunneling, b) ohmic, and c) insulator, which were observed in a random order during switch cycling. The alignment of contact asperities produced this positional effect. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tanner, DM (reprint author), Sandia Natl Labs, POB 5800,MS 1081, Albuquerque, NM 87185 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 0-7803-7649-8 J9 INT REL PHY PY 2003 BP 484 EP 490 DI 10.1109/RELPHY.2003.1197796 PG 7 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BW53W UT WOS:000182322300085 ER PT B AU Gurvits, L AF Gurvits, L GP IEEE IEEE TI What is the finiteness conjecture for linear continuous time inclusions? SO 42ND IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-6, PROCEEDINGS LA English DT Proceedings Paper CT 42nd IEEE Conference on Decision and Control CY DEC 09-12, 2003 CL Maui, HI SP IEEE, SIAM, Control Syst Soc, SICE, Informs, Honeywell Lab, Natl Instruments, XEROX, MathWorks ID STABILITY AB We give various continuous time generalizations of the discrete time finiteness "conjecture", formulated as problems about a priori norms. Ultimate answer is given for polytope norms, some low dimensional answers are given for Hilbert norms. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gurvits, L (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 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 BN 0-7803-7924-1 PY 2003 BP 1165 EP 1169 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BY66S UT WOS:000189434100201 ER PT B AU Rohwer, JA Abdallah, CT Christodoulou, CG AF Rohwer, JA Abdallah, CT Christodoulou, CG GP IEEE IEEE TI Least squares support vector machines for fixed-step and fixed-set CDMA power control SO 42ND IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-6, PROCEEDINGS LA English DT Proceedings Paper CT 42nd IEEE Conference on Decision and Control CY DEC 09-12, 2003 CL Maui, HI SP IEEE, SIAM, Control Syst Soc, SICE, Informs, Honeywell Lab, Natl Instruments, XEROX, MathWorks ID SYSTEMS AB This paper presents two machine learning based algorithms for CDMA power control. The Least Squares Support Vector Machine (LS-SVM) algorithms classify eigenvalues estimates into sets of power control commands. A binary LS-SVM algorithm generates fixed step power control (FSPC) commands, while the one vs. one multiclass LS-SVM algorithm generates estimates for fixed set power control. C1 Sandia Natl Labs, Dept 2665, Albuquerque, NM 87185 USA. RP Rohwer, JA (reprint author), Sandia Natl Labs, Dept 2665, POB 5800,MS-0986, Albuquerque, NM 87185 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 0-7803-7924-1 PY 2003 BP 5097 EP 5102 DI 10.1109/CDC.2003.1272444 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BY66S UT WOS:000189434100877 ER PT S AU Brocato, R Heller, E Omdahl, G Wendt, J Jones, S Palmer, D AF Brocato, R Heller, E Omdahl, G Wendt, J Jones, S Palmer, D GP IEEE IEEE TI High frequency SAW correlator module SO 53RD ELECTRONIC COMPONENTS & TECHNOLOGY CONFERENCE, 2003 PROCEEDINGS SE ELECTRONIC COMPONENTS AND TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT 53rd Electronic Components and Technology Conference CY MAY 27-30, 2003 CL NEW ORLEANS, LA SP IEEE, CPMT, Electr Components, Assemblies & Mat Assoc, Electr Ind Alliance AB Surface Acoustic Wave (SAW) corretators, were developed which function with central frequencies ranging from 300 MHz to 2.7 GHz. These devices enable direct translation of data to RF and back without the use of intermediate frequency stages. Several impediments to the manufacture of SAW correlators, were overcome. In addition, a programmable SAW correlator built as a flip-chip combination of lithium niobate on silicon was demonstrated. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Brocato, R (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 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 0569-5503 BN 0-7803-7991-5 J9 ELEC COMP C PY 2003 BP 458 EP 463 DI 10.1109/ECTC.2003.1216318 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BW87U UT WOS:000183448100072 ER PT S AU Yang, Q Feick, H Armitage, R Weber, ER AF Yang, Q Feick, H Armitage, R Weber, ER BE Stutzmann, M TI Metastability in the excitonic luminescence of electron-irradiated GaN SO 5TH INTERNATIONAL CONFERENCE ON NITRIDE SEMICONDUCTORS (ICNS-5), PROCEEDINGS SE Physica Status Solidi C-Current Topics in Solid State Physics LA English DT Proceedings Paper CT 5th International Conference on Nitride Semiconductors (ICNS-5) CY MAY 25-30, 2003 CL NARA, JAPAN SP Japan Soc Appl Phys, Japan Soc Promot Sci, 162nd Comm Wide Bandgap Semiconductor Photon & Elect Devices, Japan Assoc Crystal Growth, Elect Soc ID DONOR AB Metastability under focused 267 nm laser beam is observed at low temperature in the excitonic luminescence of GaN after irradiation with 0.42 MeV electrons. The oxygen-bound exciton intensity, the total band edge luminescence intensity, and the luminescence decay lifetime of free and bound excitons all increase with laser exposure time. The rate of reaching the stable state depends on the average laser power. The observed metastable behavior is explained by the carrier trapping or recombination-enhanced dissociation of non-radiative defect complexes related to N-i. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM qingyang@uclink.berkeley.edu; feick@caesar.de NR 13 TC 0 Z9 0 U1 0 U2 1 PU WILEY-VCH, INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1862-6351 BN 3-527-40489-9 J9 PHYS STATUS SOLIDI C PY 2003 VL 0 IS 7 BP 2712 EP 2715 DI 10.1002/pssc.200303312 PG 4 WC Crystallography; Materials Science, Multidisciplinary; Optics; Physics, Applied SC Crystallography; Materials Science; Optics; Physics GA BY53E UT WOS:000189401700173 ER PT B AU Aziz, S Berti, L Brigljevic, V Bruno, G Cano, E Csilling, A Cittolin, S Erhan, S Gigi, D Glege, F Gulmini, M Gutleber, J Jacobs, C Kozlovszky, M Larsen, H Litmaath, M Magrans, I Maron, G Meijers, F Meschi, E Murray, S O'Dell, V Oh, A Orsini, L Pollet, L Racz, A Samyn, D Scharff-Hansen, P Sphicas, P Schwick, C Suzuki, I Toniolo, N Zangrando, L AF Aziz, S Berti, L Brigljevic, V Bruno, G Cano, E Csilling, A Cittolin, S Erhan, S Gigi, D Glege, F Gulmini, M Gutleber, J Jacobs, C Kozlovszky, M Larsen, H Litmaath, M Magrans, I Maron, G Meijers, F Meschi, E Murray, S O'Dell, V Oh, A Orsini, L Pollet, L Racz, A Samyn, D Scharff-Hansen, P Sphicas, P Schwick, C Suzuki, I Toniolo, N Zangrando, L BE Callaos, N Chen, E Wyanor, S Wolf, A TI A simulation of an event building network for the CMS high energy physics experiment SO 7TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL, III, PROCEEDINGS: COMMUNICATION, NETWORK AND CONTROL SYSTEMS, TECHNOLOGIES AND APPLICATIONS LA English DT Proceedings Paper CT 7th World Multiconference on Systemics, Cybernetics and Informatics CY JUL 27-30, 2003 CL ORLANDO, FL SP Int Inst Informat & System DE simulation; networks; data acquisition AB A simulation of the event building network of the Data Acquisition System of the CMS experiment at the Large Hadron Collider at CERN has been developed. The simulation of this highly complex system allows the validation of the system design and the optimization of its performance. The correctness of the simulation model is verified using measurements from test set-ups and a forecast for the full-scale system is made. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Aziz, S (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA BN 980-6560-01-9 PY 2003 BP 294 EP 300 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Telecommunications SC Automation & Control Systems; Computer Science; Telecommunications GA BY46T UT WOS:000189329200056 ER PT B AU Elmore, MT Potok, TE Sheldon, FT AF Elmore, MT Potok, TE Sheldon, FT BE Callaos, N Lesso, W Rahimi, S Boonjing, V Mohamad, J Liu, TK Schewe, KD TI Dynamic data fusion using an ontology-based software agent system SO 7TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL IX, PROCEEDINGS: COMPUTER SCIENCE AND ENGINEERING: II LA English DT Proceedings Paper CT 7th World Multiconference on Systemics, Cybernetics and Informatics CY JUL 27-30, 2003 CL ORLANDO, FL SP Int Inst Informat & System AB Developing a knowledge-sharing capability across distributed heterogeneous data sources remains a significant challenge. Ontology-based approaches show promise by resolving heterogeneity, if the participating data owners agree to use a common ontology (i.e., a set of common attributes). Such common ontologies offer the capability to work with distributed data as if it were located in a central repository. This knowledge sharing may be achieved by determining the intersection of similar concepts from across various heterogeneous systems. However, if information is sought from a subset of the data sources, there may be concepts common to the subset that are not included in the full common ontology, and therefore are unavailable for knowledge sharing. We offer a novel ontology-based software agent approach that provides flexible and dynamic fusion of data across any combination of the participating data sources to maximize knowledge sharing. The software agents generate the largest intersection of shared data across any selected subset. This approach maximizes knowledge sharing by dynamically generating common ontologies over the data sources of interest. Data provided by five national laboratories was used to validate this approach by defining a local ontology for each. In this experiment, the ontologies are used to specify how to format the data using XML to make it suitable for query. Consequently, software agents provide the ability to dynamically form local ontologies from the data sources. In this way, the cost of developing these ontologies is reduced while providing the broadest possible access to available data sources. C1 Oak Ridge Natl Lab, Computat Sci & Engn Div, Appl Software Engn Res Grp, Oak Ridge, TN 37831 USA. RP Elmore, MT (reprint author), Oak Ridge Natl Lab, Computat Sci & Engn Div, Appl Software Engn Res Grp, POB 2008,MSC 6363, Oak Ridge, TN 37831 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA BN 980-6560-01-9 PY 2003 BP 5 EP 10 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BY48M UT WOS:000189346900002 ER PT B AU Potok, TE Elmore, M Reed, J Sheldon, FT AF Potok, TE Elmore, M Reed, J Sheldon, FT BE Callaos, N Lesso, W Rahimi, S Boonjing, V Mohamad, J Liu, TK Schewe, KD TI VIPAR: Advanced information agents discovering knowledge in an open and changing environment SO 7TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL IX, PROCEEDINGS: COMPUTER SCIENCE AND ENGINEERING: II LA English DT Proceedings Paper CT 7th World Multiconference on Systemics, Cybernetics and Informatics CY JUL 27-30, 2003 CL ORLANDO, FL SP Int Inst Informat & System ID INTELLIGENT AGENTS AB Given the rapid evolution of information technology, most people on a daily basis are confronted by more information than they can reasonably process. The challenge to organize/classify and comprehend immense amounts of information is vitally important to the scientific, business, and defense/security communities (particularly when projecting the future evolution of information technology. For example, the defense/security community is faced with the daunting challenge of gathering and summarizing information so that military/political leaders can make informed decisions and recommendations. One such group, the Virtual Information Center (VIC) at US Pacific Command, gathers, analyzes, and summarizes information from Internet-based newspapers on a daily basis (largely a manual, time and resource intensive process). This paper discusses the VIPAR project, which has addressed this need. Intelligent agent technology was chosen 1) to utilize the ability for broadcast as well as peer-to-peer communication among agents, 2) to follow rules outlined in an ontology, and 3) because of the ability for agents to suspend processing on one machine, move to another, and resume processing (persistence). These strengths are well suited to addressing the challenges of automatically gathering Internet-based information. The VIPAR system is a multi-agent system that demonstrates the ability to self-organize newspaper articles in a manner comparable to humans. The VIPAR system demonstrates the important ability where agents use a flexible RDF ontology to monitor/manage Internet-based newspaper information. Moreover, VIPAR extends this capability by dynamically adding/clustering new information entering the system. The VIPAR system includes thirteen information agents that manage thirteen different newspaper sites. Results from the project show that VIPAR can organize information in a way comparable to human organized information and validates the agent approach taken. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Potok, TE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA BN 980-6560-01-9 PY 2003 BP 28 EP 33 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BY48M UT WOS:000189346900006 ER PT J AU Lebedev, AV Ostrovskii, LA Sutin, AM Soustova, IA Johnson, PA AF Lebedev, AV Ostrovskii, LA Sutin, AM Soustova, IA Johnson, PA TI Resonant acoustic Spectroscopy at low Q factors SO ACOUSTICAL PHYSICS LA English DT Article ID ULTRASOUND SPECTROSCOPY; ELASTIC-CONSTANTS; COMPOSITE; TEXTURE AB The application of resonant acoustic spectroscopy to rock, building materials, and materials with cracks is hindered by the substantial mechanical losses in these materials and by the overlapping of the individual resonance responses. The paper describes a method for the determination of the resonance frequencies in low-Q materials in the presence of a strong overlapping of resonances. The effect of cracks on the values of the resonance frequencies and Q factors is studied experimentally. (C) 2003 MAIK "Nauka/Interperiodica". C1 Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603950, Russia. NOAA, Environm Technol Lab, Zell Technol, Boulder, CO 80305 USA. Stevens Inst Technol, Davidson Lab, Hoboken, NJ 07030 USA. Los Alamos Natl Lab, Los Alamos, NM 87501 USA. RP Lebedev, AV (reprint author), Russian Acad Sci, Inst Appl Phys, Ul Ulyanova 46, Nizhnii Novgorod 603950, Russia. NR 22 TC 8 Z9 8 U1 0 U2 2 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7710 J9 ACOUST PHYS+ JI Acoust. Phys. PD JAN-FEB PY 2003 VL 49 IS 1 BP 81 EP 87 DI 10.1134/1.1537392 PG 7 WC Acoustics SC Acoustics GA 644MP UT WOS:000180922100013 ER PT J AU Soszynski, I Udalski, A Szymanski, M Kubiak, M Pietrzynski, G Wozniak, P Zebrun, K Szewczyk, O Wyrzykowski, L AF Soszynski, I Udalski, A Szymanski, M Kubiak, M Pietrzynski, G Wozniak, P Zebrun, K Szewczyk, O Wyrzykowski, L TI The optical gravitational lensing experiment. Catalog of RR Lyr stars in the Large Magellanic Cloud SO ACTA ASTRONOMICA LA English DT Article DE stars : variables : RR Lyr; Magellanic Clouds; catalogs ID DIFFERENCE IMAGE-ANALYSIS; ECLIPSING BINARY STARS; DENSE STELLAR REGIONS; NONRADIAL MODES; VARIABLE-STARS; BVI MAPS; SMC DATA; LMC; PROJECT; INVENTORY AB We present the catalog of RR Lyr stars discovered in a 4.5 square degrees area in the central parts of the Large Magellanic Cloud (LMC). Presented sample contains 7612 objects, including 5455 fundamental mode pulsators (RRab), 1655 first-overtone (RRc), 272 second-overtone (RRe) and 230 double-mode RR Lyr stars (RRd). Additionally we attach a list of several dozen other short-period pulsating variables. The catalog data include astrometry, periods, BVI photometry, amplitudes, and parameters of the Fourier decomposition of the I-band light curve ' of each object. We present density map of RR Lyr stars in the observed fields which shows that the variables are strongly concentrated toward the LMC center. The modal values of the period distribution for RRab, RRc and RRe stars are 0.573, 0.339 and 0.276 days,. respectively. The period-luminosity diagrams for BVI magnitudes and for extinction insensitive index W(I) are constructed. We provide the log P-I, log P-V and log P-W(I) relations for RRab, RRc and RRe stars. The mean observed V-band magnitudes of RR Lyr stars in the LMC are 19.36 mag and 19.31 mag for ab and c types, respectively, while the extinction free values are 18.91 mag and 18.89 mag. We found a large number of RR Lyr stars pulsating in two modes closely spaced in the power spectrum. These stars are believed to exhibit non-radial pulsating modes. We discovered three stars which simultaneously reveal RR Lyr-type and eclipsing-type variability. If any of these objects were an eclipsing binary system containing RR Lyr star, then for the first time the direct determination of the mass of RR Lyr variable would be possible. We provide a list of six LMC star clusters which contain RR Lyr stars. The richest cluster, NGC 1835, hosts 84 RR Lyr variables. The period distribution of these stars suggests that NGC 1835 shares features of Oosterhoff type I and type II groups. All presented data, including individual BVI observations and finding charts are available from the OGLE INTERNET archive. C1 Univ Warsaw Observ, PL-00478 Warsaw, Poland. Univ Concepcion, Dept Fis, Concepcion, Chile. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Soszynski, I (reprint author), Univ Warsaw Observ, Urazdowskie 4, PL-00478 Warsaw, Poland. EM soszynsk@astrouw.edu.pl; udalski@astrouw.edu.pl; msz@astrouw.edu.pl; mk@astrouw.edu.pl; pietrzyn@astrouw.edu.pl; wozniak@lanl.gov; zebrun@astrouw.edu.pl; szewczyk@astrouw.edu.pl; wyrzykow@astrouw.edu.pl NR 47 TC 90 Z9 90 U1 0 U2 2 PU COPERNICUS FOUNDATION POLISH ASTRONOMY PI WARSAW PA AL UJAZDOWSKIE 4, 00-478 WARSAW, POLAND SN 0001-5237 J9 ACTA ASTRONOM JI Acta Astron. PY 2003 VL 53 IS 2 BP 93 EP 116 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 699RB UT WOS:000184068800001 ER PT J AU Zhong, Z Kao, CC Siddons, DP Zhong, H Hastings, JB AF Zhong, Z Kao, CC Siddons, DP Zhong, H Hastings, JB TI A lamellar model for the X-ray rocking curves of sagittally bent Laue crystals SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID SYNCHROTRON-RADIATION; PERFECT CRYSTALS; MONOCHROMATORS; REFLECTIVITY AB The use of sagittally bent asymmetric Laue crystals in horizontally focusing monochromators for high-energy synchrotron X-rays necessitates simulation of the X-ray reflectivity by such crystals. Based on the theory of the lattice distortion in the diffraction plane of sagittally bent Laue crystals, a lamellar model was developed to predict their rocking curves. The model was experimentally verified by rocking-curve measurements from various reflections on silicon crystals of four representative orientations, sagittally bent to various radii, using X-rays of 67 keV energy. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Akron, Dept Mech Engn, Akron, OH 44325 USA. RP Zhong, Z (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. NR 20 TC 6 Z9 6 U1 0 U2 6 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD JAN PY 2003 VL 59 BP 1 EP 6 DI 10.1107/S0108767302016835 PN 1 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 627TF UT WOS:000179951600001 PM 12496454 ER PT J AU Schlueter, JA Geiser, U Manson, JL AF Schlueter, JA Geiser, U Manson, JL TI Tetraaquabis(carbamoyldicyano-methanido-kappa N)manganese(II) dihydrate SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article AB The crystal structure of [Mn(C4H2N3O)(2)(H2O)(4)].2H(2)O, conventionally abbreviated [Mn(cdm)(2) (H2O)(4)].2H(2)O, where cdm is carbamoyldicyanomethanide, is described. The bond lengths and distances are comparable to those previously reported for the isomorphous Ni and Co analogs. Molecular units are formed by coordination of the nitrile N atoms of two cdm anions and four water molecules to the manganese(II) cation. Although these mononuclear molecular species are connected via hydrogen bonding, no magnetic ordering was observed down to 1.55 K. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Schlueter, JA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD JAN PY 2003 VL 59 BP M1 EP M3 DI 10.1107/S0108270102020334 PN 1 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 634NB UT WOS:000180345900005 PM 12506211 ER PT J AU Baker, T Dauter, Z AF Baker, T Dauter, Z TI Changing of the guard SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Editorial Material C1 Univ Auckland, Sch Biol Sci, Auckland 1, New Zealand. Brookhaven Natl Lab, Natl Canc Inst, Dept Biol, Upton, NY 11973 USA. RP Baker, T (reprint author), Univ Auckland, Sch Biol Sci, Auckland 1, New Zealand. NR 0 TC 0 Z9 0 U1 0 U2 1 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 1 EP 1 DI 10.1107/S090744490202245X PN 1 PG 1 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400001 PM 12499532 ER PT J AU Muller, P Kopke, S Sheldrick, GM AF Muller, P Kopke, S Sheldrick, GM TI Is the bond-valence method able to identify metal atoms in protein structures? SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID CRYSTALS; PARAMETERS; LENGTHS; DATABASE; SOLIDS; SITES AB The proper assignment of metal ions in X-ray structures of proteins is not always easy, but in many cases this knowledge can be important, e.g. for an understanding of enzyme mechanism. In this publication, the bond-valence approach is assessed critically. A simplified version, the calcium bond-valence sum (CBVS), is proposed for the convenient analysis of the geometric environment of potential sites with a view to metal-ion assignment. The bond-valence approach is found to be more reliable for structures determined from high-resolution data (1.5 Angstrom or better). C1 Univ Calif Los Angeles, DOE Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Univ Gottingen, Lehrstuhl Strukturchem, D-37077 Gottingen, Germany. RP Muller, P (reprint author), Univ Calif Los Angeles, DOE Lab Struct Biol & Mol Med, 205 MBI,Box 95157, Los Angeles, CA 90095 USA. RI Muller, Peter/A-8858-2008 OI Muller, Peter/0000-0001-6530-3852 NR 25 TC 57 Z9 58 U1 0 U2 8 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 32 EP 37 DI 10.1107/S0907444902018000 PN 1 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400005 PM 12499536 ER PT J AU Terwilliger, TC AF Terwilliger, TC TI Automated main-chain model building by template matching and iterative fragment extension SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID ELECTRON-DENSITY MAPS; REFINED CRYSTAL-STRUCTURE; ANGSTROM RESOLUTION; PROTEIN MODELS; RECOGNITION; LOCATION; FEATURES AB An algorithm for the automated macromolecular model building of polypeptide backbones is described. The procedure is hierarchical. In the initial stages, many overlapping polypeptide fragments are built. In subsequent stages, the fragments are extended and then connected. Identification of the locations of helical and beta-strand regions is carried out by FFT-based template matching. Fragment libraries of helices and beta-strands from refined protein structures are then positioned at the potential locations of helices and strands and the longest segments that fit the electron-density map are chosen. The helices and strands are then extended using fragment libraries consisting of sequences three amino acids long derived from refined protein structures. The resulting segments of polypeptide chain are then connected by choosing those which overlap at two or more C-alpha positions. The fully automated procedure has been implemented in RESOLVE and is capable of model building at resolutions as low as 3.5 Angstrom. The algorithm is useful for building a preliminary main-chain model that can serve as a basis for refinement and side-chain addition. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Terwilliger, TC (reprint author), Los Alamos Natl Lab, Mail Stop M888, Los Alamos, NM 87545 USA. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 NR 31 TC 486 Z9 492 U1 2 U2 11 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 38 EP 44 DI 10.1107/S0907444902018036 PN 1 PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400006 PM 12499537 ER PT J AU Terwilliger, TC AF Terwilliger, TC TI Automated side-chain model building and sequence assignment by template matching SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID ELECTRON-DENSITY MAPS; REFINED CRYSTAL-STRUCTURE; PROTEIN; RESOLUTION AB An algorithm is described for automated building of side chains in an electron-density map once a main-chain model is built and for alignment of the protein sequence to the map. The procedure is based on a comparison of electron density at the expected side-chain positions with electron-density templates. The templates are constructed from average amino-acid side-chain densities in 574 refined protein structures. For each contiguous segment of main chain, a matrix with entries corresponding to an estimate of the probability that each of the 20 amino acids is located at each position of the main-chain model is obtained. The probability that this segment corresponds to each possible alignment with the sequence of the protein is estimated using a Bayesian approach and high-confidence matches are kept. Once side-chain identities are determined, the most probable rotamer for each side chain is built into the model. The automated procedure has been implemented in the RESOLVE software. Combined with automated main-chain model building, the procedure produces a preliminary model suitable for refinement and extension by an experienced crystallographer. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Terwilliger, TC (reprint author), Los Alamos Natl Lab, Mail Stop M888, Los Alamos, NM 87545 USA. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 NR 21 TC 88 Z9 89 U1 0 U2 4 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 45 EP 49 DI 10.1107/S0907444902018048 PN 1 PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400007 PM 12499538 ER PT J AU Pletnev, V Addlagatta, A Wawrzak, Z Duax, W AF Pletnev, V Addlagatta, A Wawrzak, Z Duax, W TI Three-dimensional structure of homodimeric cholesterol esterase-ligand complex at 1.4 angstrom resolution SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID CANDIDA-RUGOSA LIPASE; PSEUDOMONAS-FLUORESCENS; CRYSTAL-STRUCTURE; CYLINDRACEA; PROTEIN; ACETYLCHOLINESTERASE; HYDROLASE; PROGRAM; SITE AB The three-dimensional structure of a Candida cylindracea cholesterol esterase (ChE) homodimer (534 x 2 amino acids) in complex with a ligand of proposed formula C23H48O2 has been determined at 1.4 Angstrom resolution in space group P1 using synchrotron low-temperature data. The structure refined to R = 0.136 and R-free = 0.169 and has revealed new stereochemical details in addition to those detected for the apo- and holo-forms at 1.9 and 2.0 Angstrom resolution, respectively [Ghosh et al. (1995), Structure, 3, 279-288]. The cholesterol esterase structure is a dimer with four spatially separated interfacial contact areas and two symmetry-related pairs of openings to an internal intradimer cavity. Hydrophobic active-site gorges in each subunit face each other across a central interfacial cavity. The ChE subunits have carbohydrate chains attached to their Asn314 and Asn351 residues, with two ordered N-acetyl-D-glucosoamine moieties visible at each site. The side chains of 14 residues have two alternative conformations with occupancy values of 0.5 +/- 0.2. For each subunit the electron density in the enzyme active-site gorge is well modeled by a C-23-chain fatty acid. C1 Hauptman Woodward Med Res Inst, Buffalo, NY USA. Russian Acad Sci, Inst Bioorgan Chem, Moscow, Russia. SUNY Buffalo, Buffalo, NY 14214 USA. Northwestern Univ, Argonne, IL USA. Adv Photon Source, Sunchrotron Res Ctr, DuPont NW Dow Collaborat Access Team, Argonne, IL USA. RP Duax, W (reprint author), Hauptman Woodward Med Res Inst, Buffalo, NY USA. RI Addlagatta, Anthony/B-1101-2010; Pletnev, Vladimir/Q-6151-2016 FU NIDDK NIH HHS [4 R37DK26546-34] NR 27 TC 17 Z9 17 U1 0 U2 2 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 50 EP 56 DI 10.1107/S0907444902018851 PN 1 PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400008 PM 12499539 ER PT J AU Uson, I Schmidt, B von Bulow, R Grimme, S von Figura, K Dauter, M Rajashankar, KR Dauter, Z Sheldrick, GM AF Uson, I Schmidt, B von Bulow, R Grimme, S von Figura, K Dauter, M Rajashankar, KR Dauter, Z Sheldrick, GM TI Locating the anomalous scatterer substructures in halide and sulfur phasing SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID CRYSTAL-STRUCTURE; SIGNAL; CRYSTALLOGRAPHY; DIFFRACTION; RESOLUTION; PROGRAM; ATOM AB Improved data quality now makes it feasible to exploit the weak anomalous signal derived only from the sulfurs inherent to the protein or in particular from halide ions incorporated by soaking. The latter technique requires the location of a high number of partially occupied halide sites. This number appears to be roughly proportional to the exposed protein surface. This paper explores the application of dual-space ab initio methods as implemented in the program SHELXD to the location of substructures of sulfur in SAD experiments, bromide in SAD and MAD experiments and iodide using SAD and SIRAS to determine the anomalous-atom substructure. Sets of atoms consistent with the Patterson function were generated as a starting point for the dual-space recycling procedure in SHELXD. The substructure is then expanded to the full structure by maximum-likelihood phasing with SHARP and density modification with the program DM. Success in the location of the substructures and subsequent phasing depends critically on the quality of the data and on the extent of the anomalous signal. This varies with each crystal and soak, but for the same crystal the significance of the anomalous signal was found to be highly sensitive to the redundancy of the intensity measurements, which in some cases made all the difference. This is illustrated by the determination of the previously unknown structure of repeat 11 of the human mannose-6-phosphate/insulin-like growth factor II receptor (Man6P/IGFII-receptor), with 310 amino acids in the asymmetric unit, which was phased by soaking the crystals in a cryoprotectant solution containing halide anions. C1 Univ Gottingen, Inst Anorgan Chem, Lehrstuhl Strukturchem, D-37077 Gottingen, Germany. Univ Gottingen, Zentrum Biochem & Mol Zellbiol, Abt Biochem 2, D-37073 Gottingen, Germany. Brookhaven Natl Lab, Natl Canc Inst, Synchrotron Radiat Res Sect, Upton, NY 11973 USA. RP Uson, I (reprint author), Univ Gottingen, Inst Anorgan Chem, Lehrstuhl Strukturchem, Tammannstr 4, D-37077 Gottingen, Germany. EM uson@shelx.uni-ac.gwdg.de NR 32 TC 38 Z9 40 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 57 EP 66 DI 10.1107/S090744490201884X PN 1 PG 10 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400009 PM 12499540 ER PT J AU Eswaramoorthy, S Gerchman, S Graziano, V Kycia, H Studier, FW Swaminathan, S AF Eswaramoorthy, S Gerchman, S Graziano, V Kycia, H Studier, FW Swaminathan, S TI Structure of a yeast hypothetical protein selected by a structural genomics approach SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID AMINO-ACID-SEQUENCE; ALANINE RACEMASE; ANGSTROM RESOLUTION; DIFFRACTION DATA; TYROSINE-265; REFINEMENT; PROJECT; MOTIFS; FOLD AB Yeast hypothetical protein YBL036C (SWISS-PROT P38197), initially thought to be a member of an 11-protein family, was selected for crystal structure determination since no structural or functional information was available. The structure has been determined independently by MIR and MAD methods to 2.0 Angstrom resolution. The MAD structure was determined largely through automated model building. The protein folds as a TIM barrel beginning with a long N-terminal helix, in contrast to the classic triose phosphate isomerase (TIM) structure, which begins with a beta-strand. A cofactor, pyridoxal 5'-phosphate, is covalently bound near the C-terminal end of the barrel, the usual active site in TIM-barrel folds. A single-domain monomeric molecule, this yeast protein resembles the N-terminal domain of alanine racemase or ornithine decarboxylase, both of which are two-domain dimeric proteins. The yeast protein has been shown to have amino-acid racemase activity. Although selected as a member of a protein family having no obvious relationship to proteins of known structure, the protein fold turned out to be a well known and widely distributed fold. This points to the need for a more comprehensive base of structural information and better structure-modeling tools before the goal of structure prediction from amino-acid sequences can be realised. In this case, similarity to a known structure allowed inferences to be made about the structure and function of a widely distributed protein family. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Swaminathan, S (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. FU NIGMS NIH HHS [GM62529] NR 35 TC 17 Z9 19 U1 0 U2 2 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 127 EP 135 DI 10.1107/S0907444902018012 PN 1 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400017 PM 12499548 ER PT J AU Daniels, BV Myles, DAA Forsyth, VT Lawson, CL AF Daniels, BV Myles, DAA Forsyth, VT Lawson, CL TI Crystals of trp repressor suitable for high-resolution neutron Laue diffraction studies SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID MACROMOLECULAR CRYSTALLOGRAPHY; PROTEIN CRYSTALLOGRAPHY; CONCANAVALIN-A; X-RAY; BINDING; ENDOTHIAPEPSIN; REFLECTIONS; EXPRESSION; MYOGLOBIN; LYSOZYME AB Crystallization and preliminary neutron-diffraction measurements of wild-type variant Val58-->Ile of the Escherichia coli trp repressor are reported. A vapor-diffusion chamber suitable for initial protein-solution volumes in the range 0.2-0.5 ml was used to grow cube-shaped crystals with edge dimensions in the range 0.8-1.4 mm. Neutron Laue measurements to a nominal resolution of 2.1 Angstrom were recorded from a D2O-exchanged crystal using the LADI instrument at ILL. These results demonstrate that it will be possible for the first time to obtain a full-atom neutron structural model of a DNA-binding protein plus its associated solvent. Direct observation of hydrogen bonding between protein and solvent should enhance understanding of the role of solvent in protein-DNA recognition. C1 Rutgers State Univ, Dept Chem & Biol Chem, Piscataway, NJ 08854 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Inst Max Von Laue Paul Langevin, European Mol Biol Lab, Grenoble Outstn, F-38042 Grenoble, France. Univ Keele, Sch Chem & Phys, Keele ST5 5BG, Staffs, England. RP Lawson, CL (reprint author), Rutgers State Univ, Dept Chem & Biol Chem, 610 Taylor Rd, Piscataway, NJ 08854 USA. RI Forsyth, V. Trevor/A-9129-2010; myles, dean/D-5860-2016 OI Forsyth, V. Trevor/0000-0003-0380-3477; myles, dean/0000-0002-7693-4964 FU NIGMS NIH HHS [GM21589] NR 33 TC 6 Z9 6 U1 0 U2 0 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JAN PY 2003 VL 59 BP 136 EP 138 DI 10.1107/S0907444902018516 PN 1 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 627UW UT WOS:000179955400018 PM 12499549 ER PT J AU Vogt, R AF Vogt, R TI Heavy quark production in heavy ion colliders SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article DE heavy quarks; perturbative QCD ID PARTON DISTRIBUTIONS; CHARM PRODUCTION; GLUON PLASMA; QCD ANALYSIS; ENERGY-LOSS; COLLISIONS; HADROPRODUCTION; SUPPRESSION; TEVATRON; NUCLEON AB We describe updated calculations of Q (Q) over bar production in pp and pi(-)p interactions. We compare these results to total cross section data and discuss how the baseline cross sections extrapolate to heavy ion collider energies. We touch upon the differences between leading and next-to-leading order heavy quark production. Finally, we discuss the implications of our calculations for quarkonium production. Our discussion here focuses on bottom quarks. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Vogt, R (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. NR 44 TC 16 Z9 16 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 18 IS 1 BP 11 EP 20 DI 10.1556/APH.18.2003.1.2 PG 10 WC Physics, Nuclear SC Physics GA 714EJ UT WOS:000184899100002 ER PT J AU Blaschke, D Burau, G Barnes, T Kalinovsky, Y Swanson, E AF Blaschke, D Burau, G Barnes, T Kalinovsky, Y Swanson, E TI Hadronic spectral function and charm meson production SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article DE J/psi suppression; Mott effect; quark-gluon plasma; charm mesons ID CHIRAL PHASE-TRANSITION; QUARK-GLUON PLASMA; J/PSI-SUPPRESSION; PSI-SUPPRESSION; MODEL; DISSOCIATION; COLLISIONS; DECONFINEMENT; KINETICS; MATTER AB At the chiral restoration/deconfinement transition, most hadrons undergo a Mott transition from being bound states in the confined phase to resonances in the deconfined phase. We investigate the consequences of this qualitative change in the hadron spectrum on final state interactions of charmonium in hot and dense matter, and show that the Mott effect for D-mesons leads to a critical enhancement of the J/psi dissociation rate. Anomalous J/psi suppression in the NA50 experiment is discussed as well as the role of the Mott effect for the heavy-flavor kinetics in future experiments at the LHC. The status of our calculations of hadron-hadron cross sections using the quark interchange and chiral Lagrangian approaches is reviewed, and an ansatz for a unification of these schemes is given. C1 Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Russia. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Joint Inst Nucl Res, Informat Technol Lab, Dubna 141980, Russia. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. RP Blaschke, D (reprint author), Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. NR 30 TC 1 Z9 1 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 18 IS 1 BP 49 EP 57 DI 10.1556/APH.18.2003.1.6 PG 9 WC Physics, Nuclear SC Physics GA 714EJ UT WOS:000184899100006 ER PT J AU Wuosmaa, AH AF Wuosmaa, AH TI Clustering in light nuclei studied with multi-particle-gamma-ray correlations SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT Symposium on Nuclear Clusters: From Light Exotic to Superheavy Nuclei CY AUG 05-09, 2002 CL MARBURG, GERMANY DE angular correlations; high spin states; resonances; segmented solid state detectors ID INELASTIC-SCATTERING; RESONANCES; C-12&C-12; SYSTEM; MG-24 AB The experimental study of clustering in light nuclei has advanced significantly in the past decade, due in part to the advent of devices such as high-resolution segmented silicon detectors. We present the results of two measurements conducted with a combination of segmented silicon strip detectors and the high-resolution gamma-ray detector array GAMMASPHERE, a determination of spins of unbound states in Mg-24, and a measurement of particle-particle-gamma-ray angular correlations to study spin alignment and resonance behavior in the C-12(C-12,C-12[0(2)(+))C-12[2(+)] inelastic scattering reaction. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Wuosmaa, AH (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 18 IS 2-4 BP 273 EP 278 DI 10.1556/APH.18.2003.2-4.25 PG 6 WC Physics, Nuclear SC Physics GA 752XD UT WOS:000187200700025 ER PT J AU Hwang, JK Fong, D Ramayya, A Hamilton, JH Jandel, M Beyer, CJ Kormicki, J Luo, YX Gore, P Kliman, J Krupa, L Morhac, M Ter-Akopian, GM Oganessian, YT Rodin, AM Fomichev, AS Popeko, GS Daniel, A Rasmussen, JO Macchiavelli, AO Lee, IY Stoyer, MA Donangelo, R Cole, JD AF Hwang, JK Fong, D Ramayya, A Hamilton, JH Jandel, M Beyer, CJ Kormicki, J Luo, YX Gore, P Kliman, J Krupa, L Morhac, M Ter-Akopian, GM Oganessian, YT Rodin, AM Fomichev, AS Popeko, GS Daniel, A Rasmussen, JO Macchiavelli, AO Lee, IY Stoyer, MA Donangelo, R Cole, JD TI Identification of Gamma transitions from He and Be ternary fission fragments SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT Symposium on Nuclear Clusters: From Light Exotic to Superheavy Nuclei CY AUG 05-09, 2002 CL MARBURG, GERMANY DE spontaneous fission; ternary fission; Cf-252 AB He and Be ternary fission processes of Cf-252 have been studied in two experiments with the Gammasphere detector array with light charged particle detectors surrounding the source. From alpha-gamma double gated spectra, neutron multiplicity distributions were determined for related a ternary fission pairs. In going from binary to a ternary SIT for approximately the same mass splittings (A approximate to 104-146) the average neutron multiplicity decreases about 0.7 AMU. In the first light charged particle (LCP) gamma-gamma experiment, the Be-10 spectrum was cutoff below 27 MeV and in the recent experiment, below 18 MeV. For high energy (E > 27 MeV) Be-10 ternary fission, the data indicate that the largest yields go via the cold process (zero neutron evaporation). In the recent experiment with E cutoff of 18 MeV, the Be-10 ternary SF was observed for zero to 4n emissions. It seems that in some cases like Te-136, the On channel is the strongest and in the other cases like Zr-100 the 1n or 2n channel dominates. Clearly, there is a shift to lower average number of neutrons emitted for Be-10 compared to a ternary SF. The Zr-104 and Te-136 cases where zero neutron emission occurs may be related to the fact that these nuclei are near the limits of the more neutron rich Zr and Te nuclei observed. The Te-136 is more spherical than the heavy partners in the other pairs and this may influence the On channel. Finally, the On channel may be more enhanced in the first data with the higher Be-10 energy cutoff, leading to lower excitation energy. Also, we confirmed the 3368 keV peak with the FWHM of 60 keV emitted from the moving Be particles in the Doppler effect corrected spectrum. C1 Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Slovak Acad Sci, Dept Nucl Phys, Bratislava, Slovakia. Joint Inst Heavy Ion Res, Oak Ridge, TN 37835 USA. Joint Inst Nucl Res, Flerov Lab Nucl React, Dubna, Russia. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Hwang, JK (reprint author), Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 18 IS 2-4 BP 383 EP 391 DI 10.1556/APH.18.2003.2-4.46 PG 9 WC Physics, Nuclear SC Physics GA 752XD UT WOS:000187200700046 ER PT J AU Vogt, R AF Vogt, R TI The usage of the K factor in heavy ion physics SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article DE Drell-Yan; heavy quarks; QCD ID HIGH-ENERGY COLLIDERS; PARTON DISTRIBUTIONS; CHARM PRODUCTION; CROSS-SECTIONS; NUCLEAR COLLISIONS; QUARK PRODUCTION; HADROPRODUCTION; ORDER; TEVATRON; SPECTRA AB The theoretical K factor, describing the difference between the leading and higher-order cross sections, can be defined in more than one way. The resulting estimate of the higher-order cross section is sensitive to the order of the fit to the parton densities and the number of loops at which a, is evaluated. We describe alternate ways to define the K factor and show how the definition affects its magnitude and shape for the examples of hadroproduction of Drell-Yan lepton pairs and heavy quarks. We discuss which definition is appropriate under what circumstances. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Vogt, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. NR 41 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 17 IS 1 BP 75 EP 92 DI 10.1556/APH.17.2003.1.9 PG 18 WC Physics, Nuclear SC Physics GA 660XA UT WOS:000181859200010 ER PT J AU David, G AF David, G CA PHENIX Collaboration TI Results from PHENIX: Year-1 and outlook SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Quark and Hadron Dynamics held in Honor of Judit Nemeth, Istvan Lovas and Jozsef Zimany CY MAR 03-07, 2002 CL BUDAPEST, HUNGARY DE relativistic heavy ion collisions ID COLLISIONS; P(T) AB The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory had its first physics run Summer 2000 colliding Au+Au ions at rootsNN = 130 GeV energy. The PHENIX experiment measured global observables of the collision, spectra of electrons and identified hadrons as well as pair correlations. This talk gives an overview of the PHENIX results as presented at the Budapest'02 Workshop on Quark and Hadron Dynamics, Budapest, Hungary, March 3-7, 2002. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP David, G (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 17 IS 2-4 BP 191 EP 196 DI 10.1556/APH.17.2003.2-4.3 PG 6 WC Physics, Nuclear SC Physics GA 699TT UT WOS:000184072600003 ER PT J AU Van Buren, G AF Van Buren, G CA STAR Collaboration TI STAR results on mixed hadron ratios SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Quark and Hadron Dynamics held in Honor of Judit Nemeth, Istvan Lovas and Jozsef Zimany CY MAR 03-07, 2002 CL BUDAPEST, HUNGARY DE quark gluon plasma; strangeness production; hyperon ID HEAVY-ION COLLISIONS; AU+AU COLLISIONS; ROOT-S(NN)=130 GEV; HADRONIZATION AB The STAR Experiment at RHIC is capable of a wide variety of measurements of the production of various hadrons in nuclear collisions. Measurements of the relative production of particle yields can shed light on the validity of models for hadron production in these collisions which may help characterize the source. We will present here preliminary results on these measurements at RHIC energies of rootsNN = 130 GeV and 200 GeV and discuss comparisons to some models. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Van Buren, G (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO RT PI BUDAPEST PA PRIELLE K U 19, PO BOX 245,, H-1117 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 17 IS 2-4 BP 197 EP 204 DI 10.1556/APH.17.2003.2-4.4 PG 8 WC Physics, Nuclear SC Physics GA 699TT UT WOS:000184072600004 ER PT J AU Xu, N AF Xu, N TI Collective dynamics at RHIC SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Quark and Hadron Dynamics held in Honor of Judit Nemeth, Istvan Lovas and Jozsef Zimany CY MAR 03-07, 2002 CL BUDAPEST, HUNGARY DE flow ID ENERGY NUCLEAR COLLISIONS; HADRON FREEZE-OUT; ROOT-S(NN)=130 GEV; ELLIPTIC FLOW; DISTRIBUTIONS; TEMPERATURE; STRANGENESS; ENHANCEMENT; YIELDS; J/PSI AB We discuss the strong collective flow effects, (V-2) and (beta(t)), observed at RHIC (roots(NN) = 130 GeV). We argue that part of the collectivity could have already developed at partonic stage. To 'see' the partonic effects directly, measurements of multi-strange baryons like Xi, Q and charmed particles like J/psi transverse momentum distributions are important. They provide one of the possible keys to the discovery of collective modes with the partonic (quarks and gluons) degrees of freedom. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Xu, N (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS70-319, Berkeley, CA 94720 USA. EM NXu@lbl.gov NR 36 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO RT PI BUDAPEST PA PRIELLE K U 19, PO BOX 245,, H-1117 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 17 IS 2-4 BP 229 EP 235 DI 10.1556/APH.17.2003.2-4.7 PG 7 WC Physics, Nuclear SC Physics GA 699TT UT WOS:000184072600007 ER PT J AU Csernai, LP Anderlik, C Keranen, A Magas, VK Manninen, J Strottman, DD AF Csernai, LP Anderlik, C Keranen, A Magas, VK Manninen, J Strottman, DD TI QGP hydrodynamics for RHIC energies SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Quark and Hadron Dynamics held in Honor of Judit Nemeth, Istvan Lovas and Jozsef Zimany CY MAR 03-07, 2002 CL BUDAPEST, HUNGARY DE relativistic hydrodynamics; heavy ion reactions ID QUARK-GLUON PLASMA; FREEZE-OUT MODELS; HEAVY-NUCLEI; COLLISIONS AB The relativistic hydrodynamic approach in this field became one of the best established theoretical and experimental methods [1]. The applicability of this method is vital, so we have to discuss the initial and final stages of heavy ion reactions in great detail, in addition to the middle stages of the reaction where the relativistic hydrodynamic description provides an adequate and accurate description of the reaction. C1 Univ Bergen, Theoret & Computat Phys Sect, N-5007 Bergen, Norway. KFKI, Res Inst Particle & Nucl Phys, H-1525 Budapest, Hungary. Univ Bergen, Parallab Computat Sci & High Performance Comp Lab, N-5020 Bergen, Norway. Oulu Univ, Dept Phys Sci, FIN-90014 Oulu, Finland. Inst Super Tecn, Ctr Phys Fundamental Interact, Dept Phys, P-1049001 Lisbon, Portugal. Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. RP Csernai, LP (reprint author), Univ Bergen, Theoret & Computat Phys Sect, Allegaten 55, N-5007 Bergen, Norway. RI Magas, Volodymyr/J-8599-2016 OI Magas, Volodymyr/0000-0003-3701-8362 NR 25 TC 3 Z9 3 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2003 VL 17 IS 2-4 BP 271 EP 280 DI 10.1556/APH.17.2003.2-4.11 PG 10 WC Physics, Nuclear SC Physics GA 699TT UT WOS:000184072600011 ER PT S AU Gavel, DT Gates, EL Max, CE Cruz, S Olivier, SS Bauman, BJ Pennington, DM Macintosh, BA Patience, J Brown, CG Danforth, PM Hurd, RL Severson, SA Lloyd, JP AF Gavel, DT Gates, EL Max, CE Cruz, S Olivier, SS Bauman, BJ Pennington, DM Macintosh, BA Patience, J Brown, CG Danforth, PM Hurd, RL Severson, SA Lloyd, JP BE Wizinowich, PL Bonaccini, D TI Recent science and engineering results with the laser guide star adaptive optics system at Lick Observatory SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES II, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Adaptive Optical System Technologies II CY AUG 22-26, 2002 CL WAIKOLOA, HI SP SPIE ID LAYER C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Gavel, DT (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 9 TC 15 Z9 15 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4618-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 4839 BP 354 EP 359 DI 10.1117/12.459680 PN 1&2 PG 6 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BW43V UT WOS:000181980700039 ER PT S AU Gavel, D Wiberg, D AF Gavel, D Wiberg, D BE Wizinowich, PL Bonaccini, D TI Toward Strehl-optimizing adaptive optics controllers SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES II, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Adaptive Optical System Technologies II CY AUG 22-26, 2002 CL WAIKOLOA, HI SP SPIE DE adaptive optics; optimal control; predictive control ID ESTIMATORS; SYSTEMS AB A main objective of adaptive optics is to maximize closed-loop Strehl, or, equivalently, minimize the statistical mean-square wavefront residual. Most currently implemented AO wavefront reconstructors and closed-loop control laws do not take into account either the correlation of the Kolmogorov wavefronts over time or the modified statistics of the residual wavefront in closed loop. There have been a number of attempts in the past to generate "predictive" controllers, which utilize wind speed and Cn2 profiles and incorporate one or two previous time steps. We present here a general framework for a dynamic controller/reconstructor design where the goal is to maximize mean closed-loop Strehl ratio over time using all previous data and exploiting the spatial-temporal statistics of the Kolmogorov turbulence and measurement noise. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Gavel, D (reprint author), Lawrence Livermore Natl Lab, L-290,POB 808, Livermore, CA 94551 USA. NR 6 TC 15 Z9 15 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4618-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 4839 BP 890 EP 901 DI 10.1117/12.459684 PN 1&2 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BW43V UT WOS:000181980700092 ER PT S AU Gavel, DT AF Gavel, DT BE Wizinowich, PL Bonaccini, D TI Suppressing anomalous localized waffle behavior in least squares wavefront reconstructors SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES II, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Adaptive Optical System Technologies II CY AUG 22-26, 2002 CL WAIKOLOA, HI SP SPIE DE wavefront reconstructors; waffle mode ID FRONT AB A major difficulty with wavefront slope sensors is their insensitivity to certain phase aberration patterns, the classic example being the waffle pattern in the Fried sampling geometry. As the number of degrees of freedom in AO systems grows larger, the possibility of troublesome waffle-like behavior over localized portions of the aperture is becoming evident. Reconstructor matrices have associated with them, either explicitly or implicitly, an orthogonal mode space over which they operate, called the singular mode space. If not properly preconditioned, the reconstructor's mode set can consist almost entirely of modes that each have some localized waffle-like behavior. In this paper we analyze the behavior of least-squares reconstructors with regard to their mode spaces. We introduce a new technique that is successful in producing a mode space that segregates the waffle-Eke behavior into a few "high order" modes, which can then be projected out of the reconstructor matrix. This technique can be adapted so as to remove any specific modes that are undesirable in the final recontructor (such as piston, tip, and tilt for example) as well as suppress (the more nebulously defined) localized waffle behavior. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gavel, DT (reprint author), Lawrence Livermore Natl Lab, POB 808,L-290, Livermore, CA 94550 USA. NR 8 TC 20 Z9 20 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4618-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 4839 BP 972 EP 980 DI 10.1117/12.459686 PN 1&2 PG 9 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BW43V UT WOS:000181980700100 ER PT S AU Poyneer, LA AF Poyneer, LA BE Wizinowich, PL Bonaccini, D TI Advanced techniques for Fourier transform wavefront reconstruction SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES II, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Adaptive Optical System Technologies II CY AUG 22-26, 2002 CL WAIKOLOA, HI SP SPIE DE adaptive optics; wavefront reconstruction; extremely large telescopes ID DIFFERENCE MEASUREMENTS; ADAPTIVE OPTICS; WAVE-FRONT AB The performance of Fourier transform (FT) reconstructors in large adaptive optics systems with Shack-Hartmann sensors and a deformable mirror is analyzed. FT methods, which are derived for point-based geometries, are adapted for use on continuous systems. Analysis and simulation show how to compensate for effects such as misalignment of the deformable mirror and wavefront sensor gain. Further filtering methods to reduce noise and improve performance are presented. These modifications can be implemented at the filtering stage, preserving, the speed of FT reconstruction and providing flexibility by allowing on-the-fly filter adaptation. Simulation of a large system shows how compensated FT methods can have equivalent or better performance to slower vector-matrix-multiply methods. The best-performing FT method is the fastest to compute, has lower noise propagation and does not suffer from waffle errors. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Poyneer, LA (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 10 TC 14 Z9 14 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4618-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 4839 BP 1023 EP 1034 DI 10.1117/12.459461 PN 1&2 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BW43V UT WOS:000181980700105 ER PT J AU Howitt, J Anderson, CW Freimuth, P AF Howitt, J Anderson, CW Freimuth, P TI Adenovirus interaction with its cellular receptor CAR SO ADENOVIRUSES: MODEL AND VECTORS IN VIRUS-HOST INTERACTIONS SE CURRENT TOPICS IN MICROBIOLOGY AND IMMUNOLOGY LA English DT Review ID TYPE-5 FIBER PROTEIN; GENE-DELIVERY; VIRUS-RECEPTOR; 1.7-ANGSTROM RESOLUTION; SEROTYPE-2 FIBER; BINDING DOMAIN; PENTON BASE; SUBGROUP-C; DNA-PKCS; COXSACKIEVIRUS AB Representative adenoviruses from four of the five major virus subgroups have been shown to interact with the 46-kDa coxsackievirus and adenovirus receptor (CAR) that is widely expressed on many human cell types, suggesting that the ability to bind CAR may be a conserved feature of many of the similar to50 known adenovirus serotypes. Receptor binding is a function of the distal 'knob' domain of the trimeric viral fiber protein. Here we review recent structural characterizations of knob, CAR and knob-CAR complexes, and we discuss how knob architecture may have evolved to accommodate opposing selective pressures to vary antigenic structure while conserving receptor binding specificity. In contrast to the hypervariability of the solvent-exposed surface of knob, the CAR receptor was found to be non-polymorphic. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Freimuth, P (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 70 TC 26 Z9 27 U1 0 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0070-217X J9 CURR TOP MICROBIOL JI Curr.Top.Microbiol.Immunol. PY 2003 VL 272 BP 331 EP 364 PG 34 WC Immunology; Microbiology SC Immunology; Microbiology GA BX34R UT WOS:000184998700011 PM 12747555 ER PT S AU Stokes, DL Allain, L Griffin, GD Mobley, J Stratis-Cullum, DN Wintenberg, AL Maples, RA Vo-Dinh, T AF Stokes, DL Allain, L Griffin, GD Mobley, J Stratis-Cullum, DN Wintenberg, AL Maples, RA Vo-Dinh, T BE VoDinh, T Grundfest, WS Benaron, DA Cohn, GE TI Biochip using a biofluidic system for detection of E-coli and other pathogens SO ADVANCED BIOMEDICAL AND CLINICAL DIAGNOSTIC SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Biomedical and Clinical Diagnostic Systems CY JAN 26-28, 2003 CL SAN JOSE, CA SP SPIE DE biochip; CMOS; integrated circuit; biofluidics; E. coli; B. anthracis; DNA; antibody; immunoassay; laser-induced fluorescence ID IN-GROUND BEEF; RAPID DETECTION; WATER; O157-H7; BACTERIA; QUALITY; CANCER; FOODS; DNA; KIT AB This work provides an overview of progress made, in our laboratory, towards the development of a practical biochip-based technology with a biofluidics system for the detection of E. coli and other pathogens. Efforts have been devoted towards efficient coupling between a compact biofluidics sample/reagent delivery system and an integrated circuit (IC) biochip, consisting of a 2-dimensional photosensor array, for on-chip monitoring of bioassays. The complementary metal-oxide semiconductor (CMOS) technology has been implemented to design and produce the IC biochip, which features a 4x4 array of independently addressable photodiodes that are integrated with amplifiers, discriminators and logic circuitry on a single platform. The CMOS-based biochip offers the advantages of compactness and low power consumption, making it better suited for field use than other array detectors, including CCDs. The biofluidics system includes a 0.4 mL hybridization chamber, which accommodates disposable sampling platforms embedded with bioreceptors for selective capture of pathogen DNA, proteins, or antibodies in discrete zones. The independently operating photodiodes of the IC biochip offer the capability of monitoring of multiple assays. Highlights of this work include highly sensitive detection of E. coli (<50 organisms) and quantitative capability with a linear dynamic range of 3-5 orders of magnitude for various assays. C1 Oak Ridge Natl Lab, Div Life Sci, Adv Biomed Sci & Technol Grp, Oak Ridge, TN 37831 USA. RP Stokes, DL (reprint author), Oak Ridge Natl Lab, Div Life Sci, Adv Biomed Sci & Technol Grp, POB 2008, Oak Ridge, TN 37831 USA. NR 18 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4758-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4958 BP 13 EP 21 DI 10.1117/12.488677 PG 9 WC Computer Science, Interdisciplinary Applications; Medical Laboratory Technology; Medicine, Research & Experimental; Physics, Applied SC Computer Science; Medical Laboratory Technology; Research & Experimental Medicine; Physics GA BX38F UT WOS:000185090600002 ER PT S AU Chuang, FYS Gutierrez, DM Nguyen, CP Johnson, DC Palmer, RA Richards, JB Chang, JT Visuri, SR Colston, BW AF Chuang, FYS Gutierrez, DM Nguyen, CP Johnson, DC Palmer, RA Richards, JB Chang, JT Visuri, SR Colston, BW BE VoDinh, T Grundfest, WS Benaron, DA Cohn, GE TI Rapid, point-of-care, multiplex immunodetection using 2-dimensional microarray technology SO ADVANCED BIOMEDICAL AND CLINICAL DIAGNOSTIC SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Biomedical and Clinical Diagnostic Systems CY JAN 26-28, 2003 CL SAN JOSE, CA SP SPIE ID INFLUENZA; ASSAY AB In response to a broad-based need for point-of-care multiplex diagnostic capability, we have developed a novel hybrid platform to analyze optically encoded microspheres arranged on a 2-dimensional planar array. The microspheres which we have initially selected are developed by Luminex Inc. as substrates for sandwich-type fluorescent immunoassays and are typically used in conjunction with a customized flow analyzer. CCD-based optics are the essential feature which enables the development of a rugged diagnostic instrument which can be scaled for point-of-care applications. We have characterized the Multiplex Immunoassay Diagnostic System (MIDS) using a benchtop prototype built around a conventional 12-bit CCD. This system is capable of resolving up to 6 discrete classes of fluorescent microbeads, and measuring their corresponding reporter signal. The MIDS sensitivity to the phycoerythrin (PE) reporter compared favorably to that of the reference Luminex flow system, and is capable of identifying viral, bacterial, and protein simulants in laboratory samples, at concentrations less than 1 mug/ml. The ability to resolve small differences in the average PE fluorescence is a direct function of CCD performance, and may be a necessary trade-off for developing a portable and economical detection system. However, we are confident that the MIDS platform can easily be scaled to meet the nominal requirements of any given point-of-care or screening application, and furthermore provide much-needed diagnostic functionality in this particular environment. C1 Lawrence Livermore Natl Lab, M Div, Livermore, CA 94550 USA. RP Chuang, FYS (reprint author), Lawrence Livermore Natl Lab, M Div, Livermore, CA 94550 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4758-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4958 BP 22 EP 26 DI 10.1117/12.485488 PG 5 WC Computer Science, Interdisciplinary Applications; Medical Laboratory Technology; Medicine, Research & Experimental; Physics, Applied SC Computer Science; Medical Laboratory Technology; Research & Experimental Medicine; Physics GA BX38F UT WOS:000185090600003 ER PT S AU Vo-Dinh, T Panjehpour, M Overholt, BF Julius, C Overholt, S Phan, MN AF Vo-Dinh, T Panjehpour, M Overholt, BF Julius, C Overholt, S Phan, MN BE VoDinh, T Grundfest, WS Benaron, DA Cohn, GE TI Laser-induced fluorescence for the detection of esophageal and skin cancer SO ADVANCED BIOMEDICAL AND CLINICAL DIAGNOSTIC SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Biomedical and Clinical Diagnostic Systems CY JAN 26-28, 2003 CL SAN JOSE, CA SP SPIE DE laser-induced fluorescence; gastrointestinal cancer; skin cancer; dysplasia; Barrett's esophagus ID SPECTROSCOPY; DIAGNOSIS; TISSUE AB Laser-induced fluorescence (LIF) is used for in-vivo cancer diagnosis of the esophagus and skin cancer. For esophageal measurements a fiberoptic probe inserted through an endoscope was used. Autofluorescence of normal and malignant tissues were measured directly on patient skin without requiring an endoscope. Measurement of the fluorescence signal from the tissue was performed using laser excitation at 410 nm. The methodology was applied to differentiate normal and malignant tumors of the esophagus and malignant skin lesions. The results of this LIF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement in the classification of normal and malignant tumors for the samples investigated. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 12 TC 5 Z9 5 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4758-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4958 BP 67 EP 70 DI 10.1117/12.488678 PG 4 WC Computer Science, Interdisciplinary Applications; Medical Laboratory Technology; Medicine, Research & Experimental; Physics, Applied SC Computer Science; Medical Laboratory Technology; Research & Experimental Medicine; Physics GA BX38F UT WOS:000185090600009 ER PT S AU Stokes, DL Allain, LR Isola, N Vo-Dinh, T AF Stokes, DL Allain, LR Isola, N Vo-Dinh, T BE VoDinh, T Grundfest, WS Benaron, DA Cohn, GE TI SERS gene probe for DNA diagnostics SO ADVANCED BIOMEDICAL AND CLINICAL DIAGNOSTIC SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Biomedical and Clinical Diagnostic Systems CY JAN 26-28, 2003 CL SAN JOSE, CA SP SPIE DE SERS; gene probe; DNA sequencing; PCR; oligonucleotides; silver surface derivatization; SAMS; Rhodamine; cresyl fast violet; brilliant cresyl blue ID ENHANCED RAMAN-SCATTERING; SINGLE-MOLECULE DETECTION; SILVER ELECTRODE; ISLAND FILMS; SURFACE; SPECTROSCOPY; GOLD; SPECTRA; DYE; PYRIDINE AB We describe the development of a surface-enhanced Raman scattering gene (SERGen) probe technology for rapid screening for diseases and pathogens through DNA hybridization assays. The technology combines the use of gene probes labeled with SERS-active markers, and nanostructured metallic platforms for inducing the SERS effect. As a result, SERGen-based methods can offer the spectral selectivity and sensitivity of SERS as well as the molecular specificity of DNA sequence hybridization. Furthermore, these new probe s preclude the use of radioactive labels. As illustrated herein, SERGen probes have been used as primers in polymerase chain reaction (PCR) amplifications of specific DNA sequences, hence further boosting the sensitivity of the technology. We also describe several approaches to developing SERS-active DNA assay platforms, addressing the challenges of making the SERGen technology accessible and practical for clinical settings. The usefulness of the SERGen approach has been demonstrated in the detection of HIV, BRCA1 breast cancer, and BAX genes. There is great potential for the use of numerous SERGen probes for multiplexed detection of multiple biological targets. C1 Oak Ridge Natl Lab, Life Sci Div, Adv Biomed Sci & Technol Grp, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Life Sci Div, Adv Biomed Sci & Technol Grp, POB 2008, Oak Ridge, TN 37831 USA. NR 36 TC 0 Z9 0 U1 1 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4758-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4958 BP 98 EP 108 DI 10.1117/12.488679 PG 11 WC Computer Science, Interdisciplinary Applications; Medical Laboratory Technology; Medicine, Research & Experimental; Physics, Applied SC Computer Science; Medical Laboratory Technology; Research & Experimental Medicine; Physics GA BX38F UT WOS:000185090600013 ER PT S AU Ewsuk, KG Arguello, JG AF Ewsuk, KG Arguello, JG BE Suzuki, H Komeya, K Sakai, M TI Science-based ceramic powder processing SO ADVANCED CERAMICS AND COMPOSITES SE Key Engineering Materials LA English DT Article; Proceedings Paper CT 2nd International Symposium on Advanced Ceramics CY NOV 19-22, 2002 CL SHANGHAI, PEOPLES R CHINA SP Japan Soc Promot Sci, 124th Comm High Temp Ceram Mat, Chinese Acad Sci, Shanghai Inst Ceram, Adv Inst Mat Sci, Asahi Glass Fdn, Ishikawa Fdn Carbon Sci & Technol, Nipple Sheet Glass Fdn Mat Sci & Engn, Tokuyama Co Ltd, Yokohama Natl Univ DE characterization; compaction; modeling; processing; sintering ID FINITE-ELEMENT SIMULATION; CRADA DEVELOPS MODEL; DIE DESIGN; COMPACTION; PARTICLE AB In ceramic component manufacturing, reproducible processing is required to cost-effectively produce reliable parts. Materials and process understanding and control are required to achieve reproducible manufacturing. In combination with advanced characterization technology, computer models are being developed and applied to enhance our fundamental understanding of ceramic processing, including the controls necessary to achieve manufacturing reproducibility. Characterization and computer modeling have been employed to identify critical relationships between powder characteristics, powder properties, and processing. Significant advances have been made in understanding particle packing, powder compaction, and sintering. Modeling can be used for tool and die design, to help optimize processing, and to anticipate and minimize defects in powder processing. Application of modeling technology to develop more robust processes and more processable powders will be a major step towards more reproducible, efficient, and cost effective manufacturing of quality ceramic components. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ewsuk, KG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 28 TC 5 Z9 5 U1 1 U2 3 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 1013-9826 BN 0-87849-924-5 J9 KEY ENG MATER PY 2003 VL 247 BP 27 EP 34 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BX35P UT WOS:000185045800004 ER PT S AU Kitayama, M Narushima, T Tran, K Gronsky, G Glaese, AM AF Kitayama, M Narushima, T Tran, K Gronsky, G Glaese, AM BE Suzuki, H Komeya, K Sakai, M TI Model studies of surfaces and interfaces in ceramics SO ADVANCED CERAMICS AND COMPOSITES SE Key Engineering Materials LA English DT Article; Proceedings Paper CT 2nd International Symposium on Advanced Ceramics CY NOV 19-22, 2002 CL SHANGHAI, PEOPLES R CHINA SP Japan Soc Promot Sci, 124th Comm High Temp Ceram Mat, Chinese Acad Sci, Shanghai Inst Ceram, Adv Inst Mat Sci, Asahi Glass Fdn, Ishikawa Fdn Carbon Sci & Technol, Nipple Sheet Glass Fdn Mat Sci & Engn, Tokuyama Co Ltd, Yokohama Natl Univ DE ceramic/metal interfaces; copper; equilibrium shape; morphological stability; nickel; sapphire; silicon carbide; surface energy; surface transport ID MICRODESIGNED INTERFACES; FACETED CRYSTALS; PORE ARRAYS; WULFF SHAPE; ALUMINA; OPPORTUNITIES; MECHANISMS; PARTICLES; EVOLUTION; CAVITIES AB For ceramics, surfaces and interfaces play a critical role in affecting the outcome of processing and sintering. The ultimate performance of ceramics and ceramic-containing composites and devices will also be impacted by surfaces and heterophase interfaces. This paper summarizes the development and application of model experiments for the study of ceramic/vapor and ceramic/metal interfaces. Lithography and etching when combined with solid-state diffusion bonding allow the internalization of controlled-geometry voids, whose morphological evolution can prove information on the coupling between surface energetics (Wulff shapes) and the kinetics of mass flow. Examples from studies - of undoped sapphire and silicon carbide will be presented. We have recently demonstrated that filling the voids with metal prior to diffusion bonding allows the fabrication of arrays of encapsulated, controlled-geometry, metal particles (nickel or copper) within a single crystal ceramic host (sapphire). The potential for using such embedded particles for studies of ceramic/metal interface energetics and shape relaxation kinetics in ceramic/metal systems will be discussed. C1 Fukuoka Inst Technol, Funct Mat Engn, Fukuoka 8110295, Japan. Tohoku Univ, Dept Met, Sendai, Miyagi 9808579, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Kitayama, M (reprint author), Fukuoka Inst Technol, Funct Mat Engn, Fukuoka 8110295, Japan. NR 21 TC 0 Z9 0 U1 1 U2 4 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 1013-9826 BN 0-87849-924-5 J9 KEY ENG MATER PY 2003 VL 247 BP 341 EP 347 PG 7 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BX35P UT WOS:000185045800073 ER PT J AU Yu, K Smarsly, B Brinker, CJ AF Yu, K Smarsly, B Brinker, CJ TI Self-assembly and characterization of mesostructured silica films with a 3D arrangement of isolated spherical mesopores SO ADVANCED FUNCTIONAL MATERIALS LA English DT Article ID MOLECULAR-SIEVES; POROUS SILICA; MEMBRANES AB We report the self-assembly and characterization of mesoporous silica thin films with a 3D ordered arrangement of isolated spherical pores. The preparation method was based on solvent-evaporation induced self-assembly (EISA), with MTES (CH3-Si(OCH2CH3)(3)) as the silica precursor and a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer as the structure-directing agent. The synthetic approach was designed to suppress the siloxane condensation rate of the siloxane network, allowing eo-self-assembly of the silica and the amphiphile, followed by retraction of the PEO chains from the silica matrix and matrix consolidation, to occur unimpeded. The calcined films retained the methyl ligands and exhibited no measurable microporosity, thereby indicating that the 3D-ordered spherical mesopores are not interconnected. A solvent-mediated formation mechanism is proposed for the absence of microporosity. Due to their closed porosity and hydrophobicity, the MTES 1 based films and MTES-TEOS (Si(OCH2CH3)(4))-based hybrid films we describe should be promising for applications such as low-k dielectrics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Ctr Micro Engineered Mat, Albuquerque, NM 87131 USA. RP Yu, K (reprint author), Sandia Natl Labs, MS 1349, Albuquerque, NM 87185 USA. RI Smarsly, Bernd/G-8514-2011; ye, bin/K-7828-2012; 牛, 开心/C-3081-2014 NR 32 TC 69 Z9 69 U1 1 U2 44 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1616-301X J9 ADV FUNCT MATER JI Adv. Funct. Mater. PD JAN PY 2003 VL 13 IS 1 BP 47 EP 52 DI 10.1002/adfm.200390005 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 644MT UT WOS:000180922400006 ER PT J AU Huynh, WU Dittmer, JJ Libby, WC Whiting, GL Alivisatos, AP AF Huynh, WU Dittmer, JJ Libby, WC Whiting, GL Alivisatos, AP TI Controlling the morphology of nanocrystal-polymer composites for solar cells SO ADVANCED FUNCTIONAL MATERIALS LA English DT Article ID CDSE NANOCRYSTALS; PHOTOVOLTAIC CELLS; QUANTUM; TRANSPORT; POLY(3-HEXYLTHIOPHENE); LUMINESCENCE; EFFICIENCY; MICROSCOPY AB We have shown recently that the use of high-aspect-ratio inorganic nanorods in conjunction with conjugated polymers is a route to obtaining efficient solar cells processed from solution. Here, we demonstrate that the use of binary solvent mixtures in which one of the components is a ligand for the nanocrystals is effective in controlling the dispersion of nanocrystals in a polymer. By varying the concentration of the solvent mixture, phase separation between the nanocrystal and polymer could be tuned from micrometer scale to nanometer scale. In addition, we can achieve nanocrystal surfaces that are free of surfactant through the use of weak binding ligands that can be removed through heating. When combined, the control of film morphology together with surfactant removal result in nanorod-polymer blend photovoltaic cells with a high external quantum efficiency of 59 % under 0.1 mW cm(-2) illumination at 450 nm. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Huynh, WU (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 27 TC 354 Z9 361 U1 0 U2 86 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1616-301X J9 ADV FUNCT MATER JI Adv. Funct. Mater. PD JAN PY 2003 VL 13 IS 1 BP 73 EP 79 DI 10.1002/adfm.200390009 PG 7 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 644MT UT WOS:000180922400010 ER PT J AU Mazaheri, AR Ahmadi, G Gamwo, IK AF Mazaheri, AR Ahmadi, G Gamwo, IK TI Hot-gas flow and particle transport and deposition in a candle filter vessel SO ADVANCED POWDER TECHNOLOGY LA English DT Article DE hot-gas; particle transport; deposition; ash deposition ID OPERATIONAL FILTRATION DATA; TURBULENT DUCT FLOW; ROUGH SURFACES; PLANT; SMOOTH AB Hot-gas flow and particle transport and deposition in an industrial filtration system are studied. The special example of the Siemens-Westinghouse filter vessel at the Power System Development Facility at Wilsonville, Alabama is treated in detail. This tangential flow filter vessel contains clusters of 91 candle filters, which are arranged in two tiers. The upper tier containing 36 candle filters is modeled by six equivalent filters. Seven equivalent filters are used in the computational model to represent the 55 candle filters in the lower tiers. The Reynolds stress turbulent model of FLUENT(TM) code is used, and the gas mean velocity and root mean square fluctuation velocities in the filter vessel are evaluated. The particle equation of motion used includes drag and gravitational forces. The mean particle deposition patterns are evaluated and the effect of particle size is studied. The computational results indicate that large particles of the order of 10 mum or larger are removed from the gas due to the centrifugal forces exerted by rotating flow between the shroud and the refractory. C1 Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Ahmadi, G (reprint author), Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. NR 33 TC 7 Z9 8 U1 0 U2 2 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0921-8831 J9 ADV POWDER TECHNOL JI Adv. Powder Technol. PY 2003 VL 14 IS 1 BP 111 EP 125 DI 10.1163/156855203762469920 PG 15 WC Engineering, Chemical SC Engineering GA 656FL UT WOS:000181598100007 ER PT B AU Fox, S Flugge, UI Rawsthorne, S Hills, M AF Fox, S Flugge, UI Rawsthorne, S Hills, M BE Murata, N Yamada, M Nishida, I Okuyama, H Sekiya, J Hajime, W TI Re-constitution of the glucose & phosphate translocator in liposomes: Inhibition of glucose & phosphate and inorganic phosphate exchange by oleoyl-coenzyme A SO ADVANCED RESEARCH ON PLANT LIPIDS LA English DT Proceedings Paper CT 15th International Symposium on Plant Lipids CY MAY 12-17, 2002 CL OKAZAKI, JAPAN SP Japan Assoc Plant Lipid Researchers ID FATTY-ACID SYNTHESIS; BRASSICA-NAPUS L.; PLASTIDS; TRANSPORTER C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Fox, S (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-1105-9 PY 2003 BP 57 EP 60 PG 4 WC Plant Sciences; Cell Biology SC Plant Sciences; Cell Biology GA BW36B UT WOS:000181696200012 ER PT S AU Rocha-Rangel, E Becher, PF Lara-Curzio, E AF Rocha-Rangel, E Becher, PF Lara-Curzio, E BE CalderonBenavides, HA CabanasMoreno, JG TI Reactive-wetting of alumina by molten aluminum alloys SO ADVANCED STRUCTURAL MATERIALS SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT Advanced Structural Materials Symposium held at the Annual Congress of the Mexican-Academy-of-Materials-Science CY AUG 26-31, 2002 CL Cancun, MEXICO SP Mexican Acad Mat Sci DE alumina; molten aluminum alloys; reactive-wetting ID SYSTEM; WETTABILITY; SAPPHIRE AB Sessile drop experiments of molten Al, Al-2.5 at. %La and Al-3 at. %Y alloys on alumina were conducted in vacuum (10(-4) to 10(-5) Pa) at 1300degreesC to obtain the time-dependent contact angles as a function of time. In all cases, it was found that the magnitude of the contact angle decreased with time. With the addition of lanthanum or yttrium, the final contact angle reached 57 and 69 degrees, respectively, at times longer than 4500 seconds, whereas for pure Al the final contact angle for the same conditions was 82 degrees. After removal of the metallic droplet from the substrate, observations of the interfacial region by scanning electron microscopy revealed a series of rings formed on the surface of the alumina substrate. Considering the high negative values of the free energy of formation of lanthanum. and yttrium oxides, the presence of these rings suggests reactive-wetting taking place between the aluminum alloys and alumina. C1 UAMA, Dept Mat, Mexico City 02200, DF, Mexico. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Rocha-Rangel, E (reprint author), UAMA, Dept Mat, Av San Pablo 180,Col Reynosa Tamaulipas, Mexico City 02200, DF, Mexico. NR 19 TC 6 Z9 6 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-930-X J9 MATER SCI FORUM PY 2003 VL 442 BP 97 EP 102 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA BY71B UT WOS:000189444600015 ER PT S AU Calzado, L Calderon, HA Mori, T Kisielowski, C Clement, N AF Calzado, L Calderon, HA Mori, T Kisielowski, C Clement, N BE CalderonBenavides, HA CabanasMoreno, JG TI HREM investigation of coherent y ' particles in Ni based superalloys SO ADVANCED STRUCTURAL MATERIALS SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT Advanced Structural Materials Symposium held at the Annual Congress of the Mexican-Academy-of-Materials-Science CY AUG 26-31, 2002 CL Cancun, MEXICO SP Mexican Acad Mat Sci DE coarsening; coherent particles; HREM; Ni-base superalloys ID ELASTIC INTERACTION ENERGY; AL ALLOYS AB The mechanism of coarsening of coherent particles in solids is investigated via high-resolution electron microscopy (HREM). Ni based alloys are used for microscopic observation of interfaces between particles (gamma') and matrix (gamma). HREM images of neighboring particles are used to ascertain whether or not such particles have the same translation order domain (TOD), and to measure the distance between them. It is found that the distance between particles is influenced by the relationship between their respective TOD. Particles with different TOD show shorter separation distances. C1 ESFM, Dept Ciencia Mat, Mexico City 07300, DF, Mexico. Univ Manchester, Inst Sci & Technol, Manchester Mat Sci Ctr, Manchester M60 1QD, Lancs, England. NCEM, Lawrence Berkeley Nat Lab, Berkeley, CA USA. CNRS, CEMES, Toulouse, France. RP Calzado, L (reprint author), ESFM, Dept Ciencia Mat, Apdo Postal 118-375, Mexico City 07300, DF, Mexico. NR 11 TC 0 Z9 0 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-930-X J9 MATER SCI FORUM PY 2003 VL 442 BP 127 EP 132 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA BY71B UT WOS:000189444600020 ER PT S AU Carrano, CJ AF Carrano, CJ BE Gonglewski, JD Vorontsov, MA Gruneisen, MT TI Anisoplanatic performance of horizontal-path speckle imaging SO ADVANCED WAVEFRONT CONTROL: METHODS, DEVICES, AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Wavefront Control: Methods Devices and Applications CY AUG 06-07, 2003 CL SAN DIEGO, CA SP SPIE DE horizontal-path imaging; slant-path imaging; isoplanatic angle; simulation; bispectral speckle imaging; extended scene reconstruction; long-range surveillance AB We have previously demonstrated and reported on the use of sub-field speckle processing for the enhancement of both near and far-range surveillance imagery of people and vehicles that have been degraded by atmospheric turbulence(1,2,3). We have obtained near diffraction-limited imagery in many cases and have shown dramatic image quality improvement in other cases. As it is possible to perform only a limited number of experiments in a limited number of conditions, we have developed a computer simulation capability to aid in the prediction of imaging performance in a wider variation of conditions. Our simulation capability includes the ability to model extended scenes in distributed turbulence. Of great interest is the effect of the isoplanatic angle on speckle imaging performance as well as on single deformable mirror and multiconjugate adaptive optics system performance. These angles are typically quite small over horizontal and slant paths. Ibis paper will begin to explore these issues which are important for predicting the performance of both passive and active horizontal and slant-path imaging systems. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Carrano, CJ (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94551 USA. NR 8 TC 14 Z9 15 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5035-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5162 BP 14 EP 27 DI 10.1117/12.508082 PG 14 WC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BY24V UT WOS:000188420300002 ER PT S AU Poyneer, LA La Fortune, K Chan, C AF Poyneer, LA La Fortune, K Chan, C BE Gonglewski, JD Vorontsov, MA Gruneisen, MT TI Scene-based wave-front sensing for remote imaging SO ADVANCED WAVEFRONT CONTROL: METHODS, DEVICES, AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Wavefront Control: Methods Devices and Applications CY AUG 06-07, 2003 CL SAN DIEGO, CA SP SPIE DE adaptive optics; remote imaging; wave-front sensing ID TECHNOLOGY; OPTICS AB Scene-based wave-front sensing (SBWFS) is a technique that allows an arbitrary scene to be used for wave-front sensing with adaptive optics (AO) instead of the normal point source. This makes AO feasible in a wide range of interesting scenarios. This paper first presents the basic concepts and properties of SBWFS. Then it discusses the application of this technique with AO to remote imaging, for the specific case of correction of a lightweight optic. End-to-end simulation results establish that in this case, SBWFS can perform as well as point-source AO. Design considerations such as noise propagation, number of subapertures and tracking changing image content are analyzed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Poyneer, LA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 15 TC 6 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5035-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5162 BP 91 EP 102 DI 10.1117/12.506483 PG 12 WC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BY24V UT WOS:000188420300010 ER PT J AU Bolan, NS Adriano, DC Curtin, D AF Bolan, NS Adriano, DC Curtin, D TI Soil acidification and liming interactions with nutrient and heavy metal transformation and bioavailability SO ADVANCES IN AGRONOMY, VOL 78 SE ADVANCES IN AGRONOMY LA English DT Review ID CATION-EXCHANGE CAPACITY; VARIABLE SURFACE-CHARGE; SOLANUM-TUBEROSUM L; NEW-ZEALAND SOILS; ORGANIC-MATTER; SEWAGE-SLUDGE; ACID SOILS; CADMIUM UPTAKE; SUBTERRANEAN CLOVER; CONTAMINATED SOILS C1 Massey Univ, Fertilizer & Lime Res Ctr, Palmerston North, New Zealand. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Crop & Food, Christchurch, New Zealand. RP Bolan, NS (reprint author), Massey Univ, Fertilizer & Lime Res Ctr, Palmerston North, New Zealand. RI Bolan, Nanthi/E-8535-2011 OI Bolan, Nanthi/0000-0003-2056-1692 NR 280 TC 107 Z9 121 U1 12 U2 78 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-2113 J9 ADV AGRON PY 2003 VL 78 BP 215 EP 272 DI 10.1016/S0065-2113(02)78006-1 PG 58 WC Agronomy SC Agriculture GA BW67F UT WOS:000182758100006 ER PT J AU Haggblom, MM Ahn, YB Fennell, DE Kerkhof, LJ Rhee, SK AF Haggblom, MM Ahn, YB Fennell, DE Kerkhof, LJ Rhee, SK TI Anaerobic dehalogenation of organohalide contaminants in the marine environment SO ADVANCES IN APPLIED MICROBIOLOGY, VOL 53 SE ADVANCES IN APPLIED MICROBIOLOGY LA English DT Review ID SPONGE APLYSINA-AEROPHOBA; MICROBIAL REDUCTIVE DEHALOGENATION; HALOGENATED AROMATIC-COMPOUNDS; POLYCHAETE NOTOMASTUS-LOBATUS; 16S RIBOSOMAL-RNA; ESTUARINE SEDIMENTS; CHLORINATED DIOXINS; POLYCHLORINATED-BIPHENYLS; DESULFOMONILE-TIEDJEI; BENZOIC-ACIDS C1 Rutgers State Univ, Dept Biochem & Microbiol, New Brunswick, NJ 08901 USA. Rutgers State Univ, Biotechnol Ctr Agr & Environm, New Brunswick, NJ 08901 USA. Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Oak Ridge Natl Lab, Microbial Genom & Ecol Grp, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Haggblom, MM (reprint author), Rutgers State Univ, Dept Biochem & Microbiol, New Brunswick, NJ 08901 USA. RI Fennell, Donna/O-1751-2013; Haggblom, Max/E-7597-2010 OI Fennell, Donna/0000-0002-4329-5174; Haggblom, Max/0000-0001-6307-7863 NR 106 TC 22 Z9 23 U1 5 U2 22 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-2164 J9 ADV APPL MICROBIOL JI Adv.Appl.Microbiol. PY 2003 VL 53 BP 61 EP + DI 10.1016/S0065-2164(03)53002-7 PG 27 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA BY22E UT WOS:000188282600002 PM 14696316 ER PT J AU Sugama, T Brothers, LE Weber, L AF Sugama, T Brothers, LE Weber, L TI Acid-resistant polydimethylsiloxane additive for geothermal well cement in 150 degrees C H2SO4 solution SO ADVANCES IN CEMENT RESEARCH LA English DT Article ID INFRARED-SPECTROSCOPY; SILICATE-GLASSES; SODIUM; TEMPERATURE; CARBONATION; SPECTRA AB The resistance of sodium polyphosphate-modified fly ash/calcium aluminate blend (SFCB) geothermal cement to H2SO4 solution (pH 1.2) at 150degreesC is enhanced by incorporating an emulsion of silanol-terminated polydmethylsiloxane (PDMS) into slurries. The crystalline phase composition of both 150degreesC-autoclaved PDMS-modified and unmodified cements consisted of three hydration reaction products: hydroxyapatite (HOAp), boehmite, and Na-P type zeolite; one carbonation product, calcite; and three unconsumed reactants: monocalcium aluminate, perovskite and quartz from calcium aluminate cement and fly ash. When unmodified cement was exposed for 20 days to hot acid, its surface was covered with the crystalline bassanite (CaSO4.1/2H2O) phase as the acid corrosion product of cement. Bassanite was,formed not only by reactions between H2SO4 and calcite or monocalcium aluminate, but also by reaction of HOAp with acid. In contrast, PDMS protected the cement against acid corrosion in two ways: it considerably reduced the formation of calcite and it abated the rate of reaction of HOAp with acid. C1 Brookhaven Natl Lab, Energy Resources Div, Energy Sci & Technol Dept, Upton, NY 11973 USA. Halliburton, Duncan, OK 73536 USA. UNOCAL Corp, Sugar Land, TX 77478 USA. RP Sugama, T (reprint author), Brookhaven Natl Lab, Energy Resources Div, Energy Sci & Technol Dept, Upton, NY 11973 USA. NR 19 TC 2 Z9 2 U1 1 U2 5 PU THOMAS TELFORD SERVICES LTD PI LONDON PA THOMAS TELFORD HOUSE, 1 HERON QUAY, LONDON E14 4JD, ENGLAND SN 0951-7197 J9 ADV CEM RES JI Adv. Cem. Res. PD JAN PY 2003 VL 15 IS 1 BP 35 EP 44 PG 10 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 653MG UT WOS:000181439900006 ER PT S AU Winter, VL Roach, S Wickstrom, G AF Winter, VL Roach, S Wickstrom, G BE Zelkowitz, MV TI Transformation-Oriented Programming: A development methodology for high assurance software SO ADVANCES IN COMPUTERS, VOL 58: HIGHLY DEPENDABLE SOFTWARE SE Advances in Computers LA English DT Article ID SYSTEM C1 Univ Nebraska, Dept Comp Sci, Omaha, NE 68182 USA. Univ Texas, El Paso, TX 79968 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Univ Nebraska, Dept Comp Sci, 6001 Dodge St,PKI 175A, Omaha, NE 68182 USA. EM vwinter@ist.unomaha.edu; sroach@cs.utep.edu; glwicks@sandia.gov NR 58 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-2458 BN 0-12-012158-1 J9 ADV COMPUT JI Adv. Comput. PY 2003 VL 58 BP 47 EP 116 DI 10.1016/S0065-2458(03)58002-0 PG 70 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA BX40E UT WOS:000185152000002 ER PT S AU Niemeyer, S Koch, L AF Niemeyer, S Koch, L GP IAEA TI The nuclear smuggling International Technical Working Group: Making a difference in combating illicit trafficking SO ADVANCES IN DESTRUCTIVE AND NON-DESTRUCTIVE ANALYSIS FOR ENVIRONMENTAL MONITORING AND NUCLEAR FORENSICS SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics CY OCT 21-23, 2002 CL Karlsruhe, GERMANY SP Int Atom Energy Agcy C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Niemeyer, S (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-110203-8 J9 P S IAEA PY 2003 BP 17 EP 19 PG 3 WC Chemistry, Analytical; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BBO78 UT WOS:000226765000003 ER PT S AU Dudder, GB Hanlen, RC Herbillon, GMJ AF Dudder, GB Hanlen, RC Herbillon, GMJ GP IAEA TI International Technical Working Group Round Robin tests SO ADVANCES IN DESTRUCTIVE AND NON-DESTRUCTIVE ANALYSIS FOR ENVIRONMENTAL MONITORING AND NUCLEAR FORENSICS SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics CY OCT 21-23, 2002 CL Karlsruhe, GERMANY SP Int Atom Energy Agcy AB The goal of nuclear forensics is to develop a preferred approach to support illicit-trafficking investigations. This approach must be widely understood and accepted as credible. The principal objectives of round robin tests conducted by the Round-Robin Task Group within the Nuclear Smuggling International Technical Working Group are to prioritize forensic techniques and methods, evaluate attribution capabilities and examine the utility of the database for attribution. The HEU (high enriched uranium) Round Robin and the previous Plutonium Round Robin have made significant contributions to fulfilling these goals through a collaborative learning experience that resulted from the outstanding efforts of members of eleven participating laboratories in ten countries. A prioritized list of techniques and methods has been developed based on these exercises. Current work is focused on the extent to which the techniques and methods can be generalized. The HEU Round Robin demonstrated a rather high level of capability to determine important characteristics of the materials and processes using analytical methods. When this capability is combined with the appropriate knowledge/data base, it results in significant capability to attribute the source of a material to a specific process or facility. Shortfalls were also identified in current capabilities, including procedures for non-nuclear forensics and lack of a comprehensive network of data/knowledge bases. The results of the round robin will be used to develop guidelines or a "recommended protocol" to be made available to interested authorities and countries for investigative use. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Dudder, GB (reprint author), Pacific NW Natl Lab, K8-41,POB 999, Richland, WA 99352 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-110203-8 J9 P S IAEA PY 2003 BP 41 EP 51 PG 11 WC Chemistry, Analytical; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BBO78 UT WOS:000226765000008 ER PT S AU Niemeyer, S Hutcheon, I AF Niemeyer, S Hutcheon, I GP IAEA TI Forensic analysis of smuggled high enriched uranium interdicted in Bulgaria SO ADVANCES IN DESTRUCTIVE AND NON-DESTRUCTIVE ANALYSIS FOR ENVIRONMENTAL MONITORING AND NUCLEAR FORENSICS SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics CY OCT 21-23, 2002 CL Karlsruhe, GERMANY SP Int Atom Energy Agcy C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Niemeyer, S (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-110203-8 J9 P S IAEA PY 2003 BP 105 EP 106 PG 2 WC Chemistry, Analytical; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BBO78 UT WOS:000226765000015 ER PT S AU Wacker, JF Wogman, NA Olsen, KB Petersen, SL Farmer, OT Kelley, JM Eiden, GC Maiti, TC AF Wacker, JF Wogman, NA Olsen, KB Petersen, SL Farmer, OT Kelley, JM Eiden, GC Maiti, TC GP IAEA TI Ultratrace analysis of uranium and plutonium by mass spectrometry SO ADVANCES IN DESTRUCTIVE AND NON-DESTRUCTIVE ANALYSIS FOR ENVIRONMENTAL MONITORING AND NUCLEAR FORENSICS SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics CY OCT 21-23, 2002 CL Karlsruhe, GERMANY SP Int Atom Energy Agcy ID ICP-MS; SAMPLES; RADIONUCLIDES; MIGRATION; ISOTOPES; RATIOS; SITE AB At the Pacific Northwest National Laboratory (PNNL), we have developed highly sensitive methods to analyse uranium and plutonium in environmental samples. Our most sensitive, well developed methodologies employ thermal ionization mass spectrometry. However, recent advances in inductively coupled plasma mass spectrometry have shown considerable promise for detecting uranium and plutonium at environmental levels. An overview is presented of the mass spectrometric methods used at PNNL to measure actinide elements in environmental samples. We compare these techniques and present results from recent studies that represent the techniques used. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Wacker, JF (reprint author), Pacific NW Natl Lab, POB 999,MSIN P7-07, Richland, WA 99352 USA. NR 22 TC 2 Z9 2 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-110203-8 J9 P S IAEA PY 2003 BP 115 EP 120 PG 6 WC Chemistry, Analytical; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BBO78 UT WOS:000226765000017 ER PT S AU Goldberg, SA Richter, S Essex, R Mason, P Schwieters, J AF Goldberg, SA Richter, S Essex, R Mason, P Schwieters, J GP IAEA TI Improved environmental and forensics measurements using multiple ion counters in isotope ratio mass spectrometry SO ADVANCES IN DESTRUCTIVE AND NON-DESTRUCTIVE ANALYSIS FOR ENVIRONMENTAL MONITORING AND NUCLEAR FORENSICS SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics CY OCT 21-23, 2002 CL Karlsruhe, GERMANY SP Int Atom Energy Agcy AB A new detector system designed for isotope ratio mass spectrometers provides improved precision on measurements of samples with very low amounts (<10(-11) g) of analyte. An array of continuous dynode electron multipliers has been installed on a new ThermoFinnigan MAT Triton thermal ionization mass spectrometer acquired by the New Brunswick Laboratory. These ion counters are modifications of miniaturized, commercially available continuous dynode electron multipliers. They can be readily installed to replace individual Faraday cups in a multidetector mass spectrometer or bundled together and located along the detector plane with a set of Faraday cups. On the New Brunswick Laboratory mass spectrometer, nine Faraday cups, one conventional discrete dynode electron multiplier and seven miniaturized ion counters were installed. The size of the miniaturized ion counters is identical to the standard Faraday cups, and thus the ion counters can be aligned with unit mass spacing for the measurement of high mass elements such as uranium and plutonium. Six of the small ion counters were bundled together and positioned on the low mass side of the Low 4 Faraday cup. One additional ion counter was positioned on the high mass side of the Low 4 Faraday cup. This arrangement allows simultaneous measurement of either all uranium (including U-233) or plutonium (including Pu-244) isotopes, also a combination of the two, and allows the measurement of larger U-238 intensities on the Faraday cup, if needed. Compensation for small mass dispersion differences at unit mass spacing of uranium, plutonium or other actinides with slightly different masses is readily achieved by the use of a mass dispersion zoom lens. The advantage of multiple ion counting is the simultaneous collection of isotopes. It overcomes many of the problems such as transient signal variation in sample emission and ionization, which would significantly reduce the attainable precision of a single collector measurement. For a given sample, multiple ion counting generates a greater number of counts for each isotope relative to single detector ion counting and provides improved counting statistics by a factor of two or more. In addition, multiple ion counting eliminates the need for drift correction algorithms that are required in single collector measurements and thus eliminates a potential source of systematic error. Initial tests indicate that the multiple ion counters exhibit high counting efficiency, a dark noise of less than 10 counts per minute and typically less than I count per minute, and show linear response characteristics over four orders of magnitude using standard deadtime correction algorithms. For higher count rates in excess of about 100000 counts per second, additional correction schemes such as the RLR algorithm can be used. ne stability of the detectors at high count rates as a function of time is being investigated, and likely will require the incorporation of this parameter into a correction algorithm. The miniaturized continuous dynode electron multipliers have sufficient stability to yield a repeatability of 0.1% RSD on the U-235/U-218 ratio in a 10 x 10(-12) g uranium samples of CRM U500. These data were obtained by measuring in the total evaporation mode. Further test results are presented. C1 US DOE, New Brunswick Lab, Argonne, IL 60439 USA. RP Goldberg, SA (reprint author), US DOE, New Brunswick Lab, 9800 S Cass Ave,Bldg 350, Argonne, IL 60439 USA. NR 4 TC 1 Z9 1 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-110203-8 J9 P S IAEA PY 2003 BP 155 EP 164 PG 10 WC Chemistry, Analytical; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BBO78 UT WOS:000226765000022 ER PT S AU Riciputi, LR Ingeneri, KB Hedberg, PML AF Riciputi, LR Ingeneri, KB Hedberg, PML GP IAEA TI Enhanced ionization efficiency using the high efficiency cavity source implemented on a magnetic sector TIMS SO ADVANCES IN DESTRUCTIVE AND NON-DESTRUCTIVE ANALYSIS FOR ENVIRONMENTAL MONITORING AND NUCLEAR FORENSICS SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics CY OCT 21-23, 2002 CL Karlsruhe, GERMANY SP Int Atom Energy Agcy ID EMISSION; URANIUM AB Traditional thermal ionization mass spectrometry (TIMS) is the most common method for determination of isotope ratios and concentration (via isotope dilution) of uranium and plutonium. Despite its exemplary performance, the thermal ionization mechanism is inefficient. Total efficiencies (the ratio of ions detected/atoms of sample loaded) are typically of the order of 0.001 to 0.1% for uranium and 0.1 to 1% for plutonium; most of the available material is lost during analysis. With the goal of improving total efficiency for analysing uranium and plutonium by TIMS, a new cavity type ion source was developed and installed on a commercial magnetic sector mass spectrometer. The dimensions and geometry of this high efficiency cavity source (HECS) combine to provide a dramatic increase in ionization efficiency and, therefore, in sample utilization. Average ionization efficiencies for the new source were 5% for uranium and 7% for plutonium. Implementation of the HECS could significantly improve detection of uranium and plutonium in safeguards and environmental sampling programmes, in addition to having applications in other arenas where high sample utilization efficiency is critical. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Riciputi, LR (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 6 TC 4 Z9 4 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-110203-8 J9 P S IAEA PY 2003 BP 347 EP 353 PG 7 WC Chemistry, Analytical; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BBO78 UT WOS:000226765000052 ER PT B AU Malba, V Evans, LB Harvey, CD Bernhardt, AF AF Malba, V Evans, LB Harvey, CD Bernhardt, AF GP asme TI V-pac: Vertical packaging for assembly-compatible chip stacks SO ADVANCES IN ELECTRONIC PACKAGING 2003, VOL 2 LA English DT Proceedings Paper CT International Electronic Packaging Technical Conference CY JUL 06-11, 2003 CL Maui, HI SP Amer Soc Mech Engineers, Elect & Photon Packaging Div AB A new process for making high-density memory stacks which are completely compatible with typical electronic assembly techniques is presented. The process uses PECVD-SiO2 passivation, laser direct-writing, electrodeposited photoresist, and metal electroplating to form a reroute pattern extending from the input/output (I/O) pads on top of the chip directly onto the chip. sidewalls. With the I/O available for interconnection on the side of the chip, four memory chips are stacked together with one silicon reroute chip. A high-temperature compatible anisotropically conductive adhesive is used to connect a flex circuit to the sidewall I/O pads of the memory chips and the reroute die. The reroute die's sidewall pads connect to a pattern on the die surface which redistributes the I/O for connection to a leadframe. The lead frame is epoxied to the reroute die, and wirebonded to complete the electrical connection. The leadframe/stack assembly is then encapsulated with an epoxy potting compound, and the leads are formed and trimmed, creating a chip stack which is indistinguishable from a standard IC package. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, 7000 E Ave,M-S L-271, Livermore, CA 94550 USA. EM malba1@llnl.gov; evans5@llnl.gov; harvey1@llnl.gov; bernhardt1@llnl.gov NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-3691-6 PY 2003 BP 853 EP 858 PG 6 WC Engineering, Aerospace; Thermodynamics; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Thermodynamics; Telecommunications GA BAK08 UT WOS:000222625600117 ER PT J AU Idachaba, MA Nyavor, K Egiebor, NO Rogers, RD AF Idachaba, MA Nyavor, K Egiebor, NO Rogers, RD TI Limitations of the NRC method of microbial stability evaluation of waste forms SO ADVANCES IN ENVIRONMENTAL RESEARCH LA English DT Article DE Tuskegee cement/cobalt chloride; waste form; Thiobacillus thiooxidans; Nuclear Regulatory Commission; degradation; leaching ID HAMBURG SEWER SYSTEM; CONCRETE; CORROSION AB In this study a critical examination of the current Nuclear Regulatory Commission (NRC) protocol for-waste forms microbial stability evaluation is carried out using Tuskegee cement/cobalt chloride. waste form and Thiobacillus thiooxidans (T thiooxidans) as models. Two major limitations were identified in,the current NRC protocol that makes it impossible to accurately use it to evaluate the stability of cement-base waste forms to microbial degradation. One of the limitations is the use of a T thiooxidans culture that is significantly lower in pH in comparison to the control medium, which could lead to an overestimation of the degradative effect of T thiooxidans. The other limitation is the use of a culture that is substrate limited, which could result in an underestimation of T. thiooxidans's capability. X radical change in approach to waste forms microbial stability evaluation is being suggested to ensure an accurate estimate of T thiooxidans involvement in waste form degradation. The approach involves the use of a two-stage system with the first stage serving as an inoculation stage and the second stage serving as the evaluation stage. At both stages the experimental and control samples are fed with solutions of similar pH, thus eliminating the pH differential which is a major weakness in the NRC protocol. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Tuskegee Univ, Dept Chem Engn, Environm Engn Program, Tuskegee, AL 36088 USA. EG&G Idaho Inc, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Idachaba, MA (reprint author), Tuskegee Univ, Dept Chem Engn, Environm Engn Program, Tuskegee, AL 36088 USA. NR 12 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1093-0191 J9 ADV ENVIRON RES JI Adv. Environ. Res. PD JAN PY 2003 VL 7 IS 2 BP 273 EP 281 AR PII S1093-0191(01)00131-9 DI 10.1016/S1093-0191(01)00131-9 PG 9 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA 649MG UT WOS:000181212100003 ER PT S AU Beach, RJ Feit, MD Mitchell, SC Cutter, KP Dawson, JW Payne, SA Mead, RW Hayden, JS Krashkevich, D Alunni, DA AF Beach, RJ Feit, MD Mitchell, SC Cutter, KP Dawson, JW Payne, SA Mead, RW Hayden, JS Krashkevich, D Alunni, DA BE Durvasula, LN TI Ribbon fiber with multiple antiguided phase-locked gain cores SO ADVANCES IN FIBER LASERS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advances in Fiber Lasers CY JAN 27-28, 2003 CL SAN JOSE, CA SP SPIE AB We report on the first experimental demonstration of a scalable fiber laser approach based on phase-locking multiple gain cores in an antiguided structure. A novel fabrication technology is used with soft glass components to construct the multiple core fiber used in our experiments. The waveguide region is rectangular in shape and comprised of a periodic sequence of gain and no-gain segments having nearly uniform refractive index. The rectangular waveguide, is itself embedded in a lower refractive index cladding region. Experimental results confirm that our five-core Nd doped glass prototype structure runs predominately in two spatial antiguided modes as predicted by our modeling. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Beach, RJ (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. RI Feit, Michael/A-4480-2009 NR 6 TC 13 Z9 13 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4774-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 4974 BP 7 EP 16 DI 10.1117/12.478275 PG 10 WC Optics; Physics, Applied SC Optics; Physics GA BX33A UT WOS:000184962900003 ER PT S AU Dawson, JW Drobshoff, A Liao, Z Beach, RJ Pennington, DM Payne, SA Taylor, L Hackenberg, W Bonaccini, D AF Dawson, JW Drobshoff, A Liao, Z Beach, RJ Pennington, DM Payne, SA Taylor, L Hackenberg, W Bonaccini, D BE Durvasula, LN TI High power 938nm cladding pumped fiber laser SO ADVANCES IN FIBER LASERS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advances in Fiber Lasers CY JAN 27-28, 2003 CL SAN JOSE, CA SP SPIE ID EFFICIENT AB We have developed a Nd:doped cladding pumped fiber amplifier, which operates at 938nm with greater than 2W of output power. The core co-dopants were specifically chosen to enhance emission at 938nm. The fiber was liquid nitrogen cooled in order to achieve four-level laser operation on a laser transition that is normally three level at room temperature, thus permitting efficient cladding pumping of the amplifier. Wavelength selective attenuation was induced by bending the fiber around a mandrel, which permitted near complete suppression of amplified spontaneous en-fission at 1088nm. We are presently seeking to scale the output of this laser to 10W. We will discuss the fiber and laser design issues involved in scaling the laser to the 10W power level and present our most recent results. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Dawson, JW (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 5 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4774-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 4974 BP 75 EP 82 DI 10.1117/12.478270 PG 8 WC Optics; Physics, Applied SC Optics; Physics GA BX33A UT WOS:000184962900011 ER PT S AU Kliner, DAV Di Teodoro, F Koplow, JP Moore, SW Smith, AV AF Kliner, DAV Di Teodoro, F Koplow, JP Moore, SW Smith, AV BE Durvasula, LN TI Efficient visible and UV generation by frequency conversion of a mode-filtered fiber amplifier SO ADVANCES IN FIBER LASERS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advances in Fiber Lasers CY JAN 27-28, 2003 CL SAN JOSE, CA SP SPIE DE ultraviolet generation; optical fiber amplifiers; frequency conversion; ytterbium ID POLED LITHIUM-NIOBATE; POLARIZATION INSTABILITIES; 2ND-HARMONIC GENERATION; PULSE AMPLIFICATION; LASER; GAIN; KTP AB We have generated the second, third, fourth, and fifth harmonics of the output of a Yb-doped fiber amplifier seeded by-a passively Q-switched Nd:YAG microchip laser. The fiber amplifier employed multimode fiber (25 mum core diameter, V approximate to 7.4) to provide high-peak-power pulses, but diffraction-limited beam quality was obtained by use of bend-loss-induced mode filtering. The amplifier output had a pulse duration of 0.97 ns and smooth, transform-limited temporal and spectral profiles (similar to500 MHz linewidth). We obtained high nonlinear conversion efficiencies using a simple optical arrangement and critically phase-matched crystals. Starting with 320 mW of average power at 1064 run (86 muJ per pulse at a 3.7 kHz repetition rate), we generated 160 mW at 532 nm, 38 mW at 355 rim, 69 mW at 266 nm, and 18 mW at 213 nm. The experimental results are in excellent agreement with calculations. Significantly higher visible and UV powers will be possible by operating the fiber amplifier at higher repetition rates and pulse energies and by further optimizing the nonlinear conversion scheme. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Kliner, DAV (reprint author), Sandia Natl Labs, POB 969,MS 9056, Livermore, CA 94551 USA. NR 21 TC 2 Z9 2 U1 2 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4774-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 4974 BP 230 EP 235 DI 10.1117/12.502207 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA BX33A UT WOS:000184962900028 ER PT J AU Espenson, JH AF Espenson, JH TI Oxygen transfer reactions: Catalysis by rhenium compounds SO ADVANCES IN INORGANIC CHEMISTRY: INCLUDING BIOINORGANIC STUDIES, VOL 54 SE ADVANCES IN INORGANIC CHEMISTRY LA English DT Review ID ATOM-TRANSFER-REACTIONS; PYRIDINE N-OXIDES; ACTIVE-SITES; OXORHENIUM(V) COMPOUND; SUBSTITUTION-REACTIONS; THIOPHENE 1,1-DIOXIDE; TRANSITION-METALS; COMPLEXES; KINETICS; OXO C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Espenson, JH (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 66 TC 39 Z9 39 U1 4 U2 16 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0898-8838 J9 ADV INORG CHEM PY 2003 VL 54 BP 157 EP 202 DI 10.1016/S0898-8838(03)54003-X PG 46 WC Chemistry, Inorganic & Nuclear SC Chemistry GA BX27T UT WOS:000184819100003 ER PT S AU Kim, JY Weil, KS AF Kim, JY Weil, KS BE Lewinsohn, CA Singh, M Loehman, R TI Development of a copper oxide-silver braze for ceramic joining SO ADVANCES IN JOINING OF CERAMICS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Joning of Ceramics held at the 104th Annual Meeting of the American-Ceramic-Society CY APR 28-MAY 01, 2002 CL ST LOUIS, MO SP Amer Ceram Soc ID ALUMINA; AG AB The joining of ceramic materials has become an increasingly important technology as the demand for high temperature structural ceramic components in gas turbines, combustion engines, heat exchangers, and burners has grown. One of the challenges in developing a useful ceramic joining technique is in forming a joint interface which can maintain its strength under a high temperature, oxidizing environment. A recently developed method of ceramic joining referred to as reactive air brazing (RAB) appears to be promising in this regard. The copper oxide-rich CuO/Ag RAB compositions investigated in the present study display excellent wettability with polycrystalline alumina, However, as will be discussed, an inverse relationship between wettability and four-point bend strength was observed. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kim, JY (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 14 TC 9 Z9 9 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-153-6 J9 CERAM TRANS PY 2003 VL 138 BP 119 EP 132 PG 14 WC Materials Science, Ceramics SC Materials Science GA BX25C UT WOS:000184738700006 ER PT S AU Saiz, E Tomsia, AP Fujino, S Gomez-Vega, JM AF Saiz, E Tomsia, AP Fujino, S Gomez-Vega, JM BE Lewinsohn, CA Singh, M Loehman, R TI Graded coatings for metallic implant alloys SO ADVANCES IN JOINING OF CERAMICS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Joning of Ceramics held at the 104th Annual Meeting of the American-Ceramic-Society CY APR 28-MAY 01, 2002 CL ST LOUIS, MO SP Amer Ceram Soc ID TRICALCIUM-PHOSPHATE; HYDROXYAPATITE; BEHAVIOR; BONE; GROWTH AB Graded glass and glass-hydroxyapatite coatings on Ti-based and Co-Cr alloys have been prepared using a simple enameling technique. The composition of the glasses has been tailored to match the thermal expansion of the alloys. By controlling the firing time, and temperature, it has been possible to control the reactivity between the glass and the alloy and to fabricate coatings (25 to 150 mum thick) with excellent adhesion to the substrate, resistant to corrosion and able to precipitate hydroxyapatite during in vitro tests in simulated body fluid. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Saiz, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 21 TC 0 Z9 0 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-153-6 J9 CERAM TRANS PY 2003 VL 138 BP 159 EP 172 PG 14 WC Materials Science, Ceramics SC Materials Science GA BX25C UT WOS:000184738700009 ER PT S AU Chou, YS Stevenson, JW AF Chou, YS Stevenson, JW BE Lewinsohn, CA Singh, M Loehman, R TI Thermal cycling of advanced compressive seals for solid oxide fuel cells SO ADVANCES IN JOINING OF CERAMICS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Joning of Ceramics held at the 104th Annual Meeting of the American-Ceramic-Society CY APR 28-MAY 01, 2002 CL ST LOUIS, MO SP Amer Ceram Soc ID GLASS-CERAMICS; SOFC; PROGRESS AB Thermal cycling was conducted on the compressive mica seals at 800degreesC in air. Thin (similar to0.1 mm) Muscovite mica was pressed between a metal tube and an alumina substrate and tested for leak rates at a stress of 100 psi in the advanced design and the plain design. The advanced design involves adding two glass interlayers and was found to greatly reduce the leak rates. Two metals (Inconel #600 and SS430) with high and low coefficients of thermal expansion (CTE) were used to evaluate the effect of CTE mismatch on thermal cycling. The results showed that the leak rates were lower for the advanced design than the plain micas. In addition, using the lower CTE (SS430) metal tube resulted in lower leak rates as compared to Inconel #600 metal (high CTE). In general, the leak rates abruptly increased during the first couple of cycles, and then tended to stabilize. Microstructure examination using scanning electron microscopy revealed damage to the mica after thermal cycling. C1 Pacific NW Natl Lab, Mat Resource Dept, Richland, WA 99352 USA. RP Chou, YS (reprint author), Pacific NW Natl Lab, Mat Resource Dept, K2-44,POB 999, Richland, WA 99352 USA. NR 11 TC 0 Z9 0 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-153-6 J9 CERAM TRANS PY 2003 VL 138 BP 175 EP 184 PG 10 WC Materials Science, Ceramics SC Materials Science GA BX25C UT WOS:000184738700010 ER PT S AU Weil, KS Hardy, JS AF Weil, KS Hardy, JS BE Lewinsohn, CA Singh, M Loehman, R TI Brazing a mixed ionic/electronic conductor to an oxidation resistant metal SO ADVANCES IN JOINING OF CERAMICS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Joning of Ceramics held at the 104th Annual Meeting of the American-Ceramic-Society CY APR 28-MAY 01, 2002 CL ST LOUIS, MO SP Amer Ceram Soc ID COPPER-OXIDE; FUEL-CELLS; ALUMINA; CERAMICS; MEMBRANES; OXYGEN; AG AB High temperature, solid-state electrochemical devices have received considerable attention in recent years because of their technological importance in a wide array of applications, including chemical sensors, solid oxide fuel cells, gas separation devices, and electrocatalyzers. While numerous advances have been made in the fabrication and performance of the ceramic materials that form the heart of the working device, less emphasis has been placed on the materials that will be used in the balance of the device; in particular, the seals that bond the functional ceramic to the metallic structural component. In an effort to begin addressing this issue, a new brazing concept referred to as reactive air brazing has been developed. This paper discusses the details of this joining technique and illustrates its use in bonding a potential oxygen separation material, (La0.6Sr0.4)(Co0.2Fe0.8)O-3, to an alumina scale-forming stainless steel alloy. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Weil, KS (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Hardy, John/E-1938-2016 OI Hardy, John/0000-0002-1699-3196 NR 23 TC 2 Z9 2 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-153-6 J9 CERAM TRANS PY 2003 VL 138 BP 185 EP 200 PG 16 WC Materials Science, Ceramics SC Materials Science GA BX25C UT WOS:000184738700011 ER PT J AU Abanov, A Chubukov, AV Schmalian, J AF Abanov, A Chubukov, AV Schmalian, J TI Quantum-critical theory of the spin fermion model and its application to cuprates: normal state analysis SO ADVANCES IN PHYSICS LA English DT Review ID HIGH-TEMPERATURE SUPERCONDUCTORS; 2-DIMENSIONAL HUBBARD-MODEL; T-C SUPERCONDUCTORS; ANGLE-RESOLVED PHOTOEMISSION; RAMAN-SCATTERING; QUASI-PARTICLE; NEUTRON-SCATTERING; CRITICAL-POINT; CRITICAL-BEHAVIOR; SPECTRAL-FUNCTION AB We present the full analysis of the normal state properties of the spin-fermion model near the antiferromagnetic instability in two dimensions. The model describes low-energy fermions interacting with their own collective spin fluctuations, which soften at the antiferromagnetic transition. We argue that in 2D, the system has two typical energies an effective spin fermion interaction (g) over bar and an energy omega(sf) below which the system behaves as a Fermi liquid. The ratio of the two determines the dimensionless coupling constant for spin fermion interaction lambda(2) proportional to (g) over bar/omega(sf). We show that lambda scales with the spin correlation length and diverges at criticality. This divergence implies that the conventional perturbative expansion breaks down. We develop a novel approach to the problem the expansion in either the inverse number of hot spots in the Brillouin zone, or the inverse number of fermionic-flavours which allows us to explicitly account for all terms which diverge as powers of lambda, and treat the remaining, O(log lambda) terms in the RG formalism. We apply this technique to study the properties of the spin fermion model in various frequency and temperature regimes. We present the results for the fermionic spectral function, spin susceptibility, optical conductivity and other observables. We compare our results in detail with the normal state data for the cuprates, and argue that the spin fermion model is capable of explaining the anomalous normal state properties of the high T-c materials. We also show that the conventional phi(4) theory of the quantum-critical behaviour is inapplicable in 2D due to the singularity of the phi(4) vertex. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Chubukov, AV (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. EM chubukov@skazka.physics.wisc.edu RI Schmalian, Joerg/H-2313-2011 NR 187 TC 262 Z9 262 U1 6 U2 23 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0001-8732 EI 1460-6976 J9 ADV PHYS JI Adv. Phys. PY 2003 VL 52 IS 3 BP 119 EP 218 DI 10.1080/0001873021000057123 PG 100 WC Physics, Condensed Matter SC Physics GA 633LH UT WOS:000180284400001 ER PT S AU Lenhart, JL Fischer, DA Sambasivan, S Lin, EK Jones, RL Soles, CL Wu, WL Goldfarb, DL Angelopoulos, M AF Lenhart, JL Fischer, DA Sambasivan, S Lin, EK Jones, RL Soles, CL Wu, WL Goldfarb, DL Angelopoulos, M BE Fedynyshyn, TH TI X-ray absorption spectroscopy to probe interfacial issues in photolithography SO ADVANCES IN RESIST TECHNOLOGY AND PROCESSING XX, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 20th Annual Conference on Advances in Resist Technology and Processing CY JAN 24-26, 2003 CL SANTA CLARA, CA SP SPIE, Int SEMATECH, Semicond Equipment Mat Int ID CHEMICALLY AMPLIFIED RESISTS; LINE EDGE ROUGHNESS; DEEP-ULTRAVIOLET RESISTS; AIRBORNE CONTAMINATION; ACID-DIFFUSION; REACTION FRONT; POSITIVE-TONE; LITHOGRAPHY; PHOTORESISTS; DISSOLUTION AB We utilize-near edge X-ray absorption fine structure spectroscopy (NEXAFS) to provide detailed chemical insight into two interfacial Problems facing sub-100 nm patterning. First, chemically amplified photo-resists are sensitive to surface phenomenon, which causes deviations in the pattern profile near the interface.. Striking examples include T-topping; closure, footing, and undercutting. NEXAFS was used to examine surface segregation of a photo-acid generator at the resist/air interface and to illustrate that the surface extent of deprotection in A model resist film can be different than the bulk extent of deprotection. Second, line edge roughness becomes increasingly critical with shrinking patterns, and may be intimately related to the line edge deprotection profile. A NEXAFS technique to surface depth profile for compositional gradients is described with the potential to provide chemical information about the resist line edge. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lenhart, JL (reprint author), Sandia Natl Labs, POB 5800,MS 1411, Albuquerque, NM 87185 USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4844-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 5039 BP 343 EP 356 DI 10.1117/12.485149 PG 14 WC Materials Science, Coatings & Films; Optics; Imaging Science & Photographic Technology; Polymer Science SC Materials Science; Optics; Imaging Science & Photographic Technology; Polymer Science GA BX07Y UT WOS:000184199500036 ER PT J AU Iqbal, A Kashani-Poor, AK AF Iqbal, Amer Kashani-Poor, Amir-Kian TI Instanton Counting and Chern-Simons Theory SO ADVANCES IN THEORETICAL AND MATHEMATICAL PHYSICS LA English DT Article AB The instanton partition function of N = 2, D = 4 SU(2) gauge theory is obtained by taking the field theory limit of the topological open string partition function, given by a Chern-Simons theory, of a CY3-fold. The CY3-fold on the open string side is obtained by geometric transition from local IP1 x IP1 which is used in the geometric engineering of the SU(2) theory. The partition function obtained from the Chern-Simons theory agrees with the closed topological string partition function of local IP1 x IP1 proposed recently by Nekrasov. We also obtain the partition functions for local F-1 and F-2 CY3-folds and show that the topological string amplitudes of all three local Hirze-bruch surfaces give rise to the same field theory limit. It is shown that a generalization of the topological closed string partition function whose field theory limit is the generalization of the instanton partition function, proposed by Nekrasov, can be determined easily from the Chern-Simons theory. C1 [Iqbal, Amer] Harvard Univ, Jefferson Lab, Cambridge, MA 02138 USA. [Kashani-Poor, Amir-Kian] Stanford Univ, Dept Phys, Stanford, CA 94305 USA. [Kashani-Poor, Amir-Kian] Stanford Univ, SLAC, Stanford, CA 94305 USA. RP Iqbal, A (reprint author), Harvard Univ, Jefferson Lab, Cambridge, MA 02138 USA. FU NSF [NSF-DMS/00-74329]; Department of Energy [DE-AC03-76SF00515] FX AI would like to thank Mina Aganagic, Marcos Marino and Cumrun Vafa for valuable discussions. AK would like to thank Allan Adams, Sergei Gukov, and David Morrison for helpful conversations. The research of AI was supported by NSF award NSF-DMS/00-74329. The research of AK was supported by the Department of Energy under contract number DE-AC03-76SF00515. NR 31 TC 13 Z9 13 U1 0 U2 0 PU INT PRESS BOSTON, INC PI SOMERVILLE PA PO BOX 43502, SOMERVILLE, MA 02143 USA SN 1095-0761 J9 ADV THEOR MATH PHYS JI Adv. Theor. Math. Phys. PY 2003 VL 7 IS 3 BP 457 EP 497 PG 41 WC Physics, Particles & Fields; Physics, Mathematical SC Physics GA V29BZ UT WOS:000208725200004 ER PT J AU Freedman, VL Ibaraki, M AF Freedman, VL Ibaraki, M TI Coupled reactive mass transport and fluid flow: Issues in model verification SO ADVANCES IN WATER RESOURCES LA English DT Article DE geochemistry; geochemical models; solute transport; density; hydrogeology; numerical models ID POROUS-MEDIA; HYDROTHERMAL SYSTEMS; CHEMICAL-TRANSPORT; PRECIPITATION; DISSOLUTION; CANNOT AB Model verification and validation are both important steps in the development of reactive transport models. In this paper. a distinction is made between verification and validation, and the focus is on codifying the issues of verification for a numerical, reactive transport flow model. First, the conceptual basis of model verification is reviewed, which shows that verification should be understood as a first step in model development, and be followed by a protocol that assures that the model accurately represents system behavior. Second, commonly used procedures and methods of model verification are presented. In the third part of this paper, an intercomparison of models is used to demonstrate that model verification can be performed despite differences in hydrogeochemical transport code formulations. Results of an example simulation of transport are presented in which the numerical model is tested against other hydrogeochemical codes. Different kinetic formulations between solid and aqueous phases used among numerical models complicates model verification. This test problem involves uranium transport under conditions of varying pH and oxidation potential, with reversible precipitation of calcium uranate and coffinite. Results between the different hydrogeochemical transport codes show differences in oxidation potentials, but similarities in mineral assemblages and aqueous transport patterns. Because model verification can be further complicated by differences in the approach for solving redox problems, a comparison of a fagacity approach (based on 0, partial pressure) to both the external approach (based on hypothetical electron activity) and effective internal approach (based on conservation of electrons) is performed. The comparison demonstrates that the oxygen fugacity approach produces different redox potentials and mineral assemblages than both the effective internal and external approaches. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Ohio State Univ, Dept Geol Sci, Columbus, OH 43210 USA. RP Freedman, VL (reprint author), Pacific NW Natl Lab, POB 999 MSIN K9-36, Richland, WA 99352 USA. EM vicky.freedman@pnl.gov; iba-raki.1@osu.edu NR 32 TC 3 Z9 4 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD JAN PY 2003 VL 26 IS 1 BP 117 EP 127 AR PII S0309-1708(02)00106-9 DI 10.1016/S0309-1708(02)00106-9 PG 11 WC Water Resources SC Water Resources GA 635ZY UT WOS:000180431100011 ER PT B AU Dale, LL Whitehead, CD Williams, NA AF Dale, LL Whitehead, CD Williams, NA BE Maksimovic, C Butler, D Memon, FA TI Trends in California Water metering: a preliminary analysis SO ADVANCES IN WATER SUPPLY MANAGEMENT LA English DT Proceedings Paper CT International Conference on Advances in Water Supply Management CY SEP 15-17, 2003 CL IMPERIAL COLL LONDON, LONDON, ENGLAND SP Comp & Control Water Ind HO IMPERIAL COLL LONDON AB Despite growing water scarcity, many water districts in California sell water to customers on a flat rate basis at a time when many policy makers advise sales on a volumetric basis to conserve water. A transactions cost model clarifies the district choice of water sales practice. The model assumes that districts maximize net consumer benefits when choosing between a flat rate and a volumetric sales option. The model is used to explain the observed pattern of flat rate and volumetric sale practices in the Central Valley of California and to predict the increase in volumetric sales resulting from art increase in the average cost of water. A logistic regression analysis of this data indicates that local water cost explains much of the variation in water sale practices in the Central Valley, as predicted by the model. C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Dale, LL (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5809-608-4 PY 2003 BP 573 EP 580 PG 8 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BX68B UT WOS:000186106300061 ER PT B AU Herling, D Hunt, W AF Herling, D Hunt, W BE Pandey, AB Kendig, KL Lewandowski, JJ Shah, SS TI Low cost cast aluminum metal matrix composites have arrived SO AFFORDABLE METAL MATRIX COMPOSITES FOR HIGH-PERFORMANCE APPLICATIONS II LA English DT Proceedings Paper CT International Symposium on Powder Materials - Current Research and Industrial Practices III held at the Materials Science and Technology Meeting CY NOV 09-12, 2003 CL CHICAGO, IL SP TMS Powder Mat Comm DE metal matrix composites; MMC; brake rotor; casting AB Aluminum metal matrix composites (MMC) have found applications in many industries, from aerospace and automotive to sporting goods and electronics packaging [1-5]. Many of the primary applications have been in military components and structures, where advanced high performance materials are necessary to meet vigorous material challenges. Aluminum MMC are attractive due to their lightweight and high specific stiffness. In addition, the ceramic particle reinforcement significantly increases the wear resistance of these materials. Nevertheless, high materials costs relative to conventional aluminum alloys have been the primary limit to widespread use of such a material family. The use of particulate instead of fiber reinforcement has helped to reduce the overall material cost for those applications that do not require the additional strength obtained from fiber reinforced composites. However, for many cost sensitive industries, such as the on-highway transportation industry, widespread application of particulate reinforced MMC is still limited due to cost and availability. There are two primary components that makeup the cost of metal matrix composite feedstock material. The first is the raw material cost, which is somewhat controlled by the cost of aluminum. However, the raw material used for the reinforcement can play a significant role in the overall MMC material cost. This incurred cost can be affected through the use of alternative and less costly ceramic material options. The other source of cost is related to the compositing processes used to make the aluminum MMC materials. If the cost associated with these two aspects can be controlled and reduced, then this could enable widespread use of particle reinforced aluminum MMC materials. Metal Matrix Composites for the 21(st) Century (MC-21), Inc., in Carson City, Nevada, has developed a novel rapid mixing process for the production of MMC materials. This is a proprietary process, with the focus of rapidly mixing the particulate into the matrix alloy. The process claims to significantly reduce the time required for mixing, and therefore can reduce the labor and ultimately MMC material costs. In addition, it is proposed to place such a modular mixing system at the site of a foundry, producing the composite material as needed and transferring the molten material directly to the casting floor, without the need for remelting of ingot. This would potentially aid in reducing costs. Further cost savings can be realized with the use of a low cost SiC material for the reinforcement, compared to the standard F-500 grade used in the industry. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Herling, D (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,MS K2-03, Richland, WA 99352 USA. NR 10 TC 1 Z9 1 U1 4 U2 5 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-557-3 PY 2003 BP 13 EP 23 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY52G UT WOS:000189399400002 ER PT J AU West, OR Tsouris, C Lee, S McCallum, SD Liang, LY AF West, OR Tsouris, C Lee, S McCallum, SD Liang, LY TI Negatively buoyant CO2-hydrate composite for ocean carbon sequestration SO AICHE JOURNAL LA English DT Article ID HYDRATE FORMATION; CO2 HYDRATE; DISPOSAL C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Wales Coll Cardiff, Sch Engn, Cardiff, S Glam, Wales. RP West, OR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Liang, Liyuan/O-7213-2014; Tsouris, Costas/C-2544-2016 OI Liang, Liyuan/0000-0003-1338-0324; Tsouris, Costas/0000-0002-0522-1027 NR 10 TC 21 Z9 22 U1 2 U2 4 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD JAN PY 2003 VL 49 IS 1 BP 283 EP 285 DI 10.1002/aic.690490127 PG 3 WC Engineering, Chemical SC Engineering GA 636LQ UT WOS:000180457800026 ER PT S AU Wells, L Doerry, AW AF Wells, L Doerry, AW BE Andraitis, AA Greer, JD Leygraaf, GJ TI Synthetic aperture radar: not just a sensor of last resort SO AIRBORNE RECONNAISSANCE XXVII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Reconnaissance XXVII CY APR 22-23, 2003 CL ORLANDO, FL SP SPIE DE SAR; radar; image; resolution; high-performance AB Modern high-performance Synthetic Aperture Radar (SAR) systems have evolved into highly versatile, robust, and reliable tactical sensors, offering images and information not available from other sensor systems. For example, real-time images are routinely formed by the Sandia-designed General Atomics (AN/APY-8) Lynx SAR yielding 4-inch resolution at 25 kin range (representing better than arc-second resolutions) in clouds, smoke, and rain. Sandia's Real-Time Visualization (RTV) program operates an Interferometric SAR (IFSAR) system that forms three dimensional (3-D) topographic maps in near real-time with National Imagery and Mapping Agency (NIMA) Digital Terrain Elevation Data (DTED) level 4 performance (3 meter post spacing with 0.8-meter height accuracy) or better. When exported to 3-D rendering software, this data allows remarkable interactive fly-through experiences. Coherent Change Detection (CCD) allows detecting tire tracks on dirt roads, foot-prints, and other minor, otherwise indiscernible ground disturbances long after their originators have left the scene. Ground Moving Target Indicator (GMTI) radar modes allow detecting and tracking moving vehicles. A Sandia program known as "MiniSAR" is developing technologies that are expected to culminate in a fully functioning, high-performance, real-time SAR that weighs less than 20 lbs. The purpose of this paper is to provide an overview of recent technology developments, as well as current on-going research and development efforts at Sandia National Laboratories. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Wells, L (reprint author), POB 5800,MS 0519, Albuquerque, NM 87185 USA. NR 10 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4969-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 5109 BP 98 EP 109 DI 10.1117/12.487282 PG 12 WC Instruments & Instrumentation; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Imaging Science & Photographic Technology GA BX48P UT WOS:000185396300011 ER PT J AU Hitzemann, R Hitzemann, B Rivera, S Gatley, J Thanos, P Shou, LLSM Williams, RW AF Hitzemann, R Hitzemann, B Rivera, S Gatley, J Thanos, P Shou, LLSM Williams, RW TI Dopamine D-2 receptor binding, Drd2 expression and the number of dopamine neurons in the BXD recombinant inbred series: Genetic relationships to alcohol and other drug associated phenotypes SO ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH LA English DT Article DE genetic; recombinant inbred; QTL; dopamine receptor; Drd2 expression; microarray; tyrosine hydroxylase; conditioned place preference. ID QUANTITATIVE-TRAIT LOCI; HALOPERIDOL-INDUCED CATALEPSY; CONDITIONED PLACE PREFERENCE; INDIVIDUAL-DIFFERENCES; ALLELIC ASSOCIATION; LOCOMOTOR-ACTIVITY; MOUSE STRAINS; CELL-DENSITY; AL ALLELE; MICE AB Background: It has not been established to what extent the natural variation in dopamine systems contribute to the variation in ethanol response. The current study addresses this issue by measuring D-2 dopamine (DA) receptor binding, the expression of Drd2, the number of midbrain DA neurons in the BXD recombinant inbred (RI) series and then compares these strain means with those previously reported for a variety of ethanol and other drug-related phenotypes. Methods: Data were collected for 21 to 23 of the BXD RI strains and the parental strains. D-2 DA receptor autoradiography was performed using I-125-epidepride as the ligand [Kanes S, Dains K, Cipp L, Gatley J, Hitzemann B, Rasmussen E, Sanderson S, Silverman S, Hitzemann R (1996) Mapping the genes for haloperidol-induced catalepsy. J Pharmacol Exp, Ther 277:1016-1025]. Drd2 expression was measured using the Affymetrix oligoarray system. Immunocytochemical techniques were used to determine the number of midbrain DA neurons [Hitzemann 13, Dains K, Hitzemann R (1994) Further studies on the relationship between dopamine cell density and haloperidol response. J Pharmacol Exp Ther 271:969-976]. Results and Conclusions: The range of difference in receptor binding for the RI strains was approximately 2-fold in all regions examined, the core, the shell of the nucleus accumbens (NAc) and the dorsomedial caudate-putamen (CPu); heritability in all regions was moderate-(h2 similar to 0.35). Drd2 expression in forebrain samples from the RI and parental strains ranged 1.5- to 2-fold and h(2) was moderate-0.47. Variation in the number of tyrosine hydroxylase (TH) positive neurons was moderate, 41% and 26% and h(2) was low-0.19 and 0.15 for the ventral tegmental area (VTA) and substantia nigra compacta (SNc), respectively. Significant correlations were found between D-2 DA receptor binding and the low dose (1.33 g/kg) ethanol stimulant response. (p < 0.002) and between Drd2 expression and conditioned place preference (CPP) (p < 0.0005). No significant correlations were detected between ethanol preference and either receptor binding or Drd2 expression; however, a significant correlation was found between preference and Ncam expression. Ncam is approximately 0.2 Mb from Drd2. Overall, the data suggest ethanol preference and CPP are associated with the expression of Drd2 or closely linked genetic loci. C1 SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Univ Tennessee, Ctr Hlth Sci, Ctr Genomics & Bioinformat, Memphis, TN 38163 USA. RP Hitzemann, R (reprint author), Oregon Hlth Sci Univ, Dept Behav Neurosci, Portland, OR 97201 USA. OI Williams, Robert/0000-0001-8924-4447 FU NIAAA NIH HHS [AA 11043, AA 11384] NR 65 TC 28 Z9 29 U1 1 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0145-6008 J9 ALCOHOL CLIN EXP RES JI Alcoholism (NY) PD JAN PY 2003 VL 27 IS 1 BP 1 EP 11 DI 10.1097/01.ALC.000047862.40562.27 PG 11 WC Substance Abuse SC Substance Abuse GA 640VZ UT WOS:000180709800001 PM 12543998 ER PT J AU McCune, W Padmanabhan, R Veroff, R AF McCune, W Padmanabhan, R Veroff, R TI Yet another single law for lattices SO ALGEBRA UNIVERSALIS LA English DT Article DE lattice basis; lattice single identity AB In this note we show that the equational theory of all lattices is defined by the single absorption law (((yboolean ORx)boolean ANDx)boolean OR(((zboolean AND(xboolean ORx))boolean OR(uboolean ANDx))boolean ANDv))boolean AND(wboolean OR((sboolean ORx)boolean AND(xboolean ORt))) = x. This identity of length 29 with 8 variables is shorter than previously known such equations defining lattices. C1 Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60419 USA. Univ Manitoba, Dept Math, Winnipeg, MB R3T 2N2, Canada. Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. RP McCune, W (reprint author), Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60419 USA. EM mccune@mcs.anl.gov; padman@cc.umanitoba.ca; veroff@cs.unm.edu NR 12 TC 1 Z9 3 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0002-5240 J9 ALGEBRA UNIV JI Algebr. Universalis PY 2003 VL 50 IS 2 BP 165 EP 169 DI 10.1007/s00012-003-1832-2 PG 5 WC Mathematics SC Mathematics GA 801QW UT WOS:000220111400005 ER PT J AU Bailey, CG Oliveira, JS AF Bailey, CG Oliveira, JS TI Cube-like structures generated by filters SO ALGEBRA UNIVERSALIS LA English DT Article DE Boolean algebras; cubic algebras; intervals; filters AB The join semi-lattice of faces of an n-cube Haas a rich structure. In considering generalizations of these structures we are led to looking at. interval algebras constructed using Boolean filters. We look at, the structure of these algebras and their automorphisin groups. C1 Victoria Univ Wellington, Sch Math & Comp Sci, Wellington, New Zealand. Pacific NW Natl Lab, Richland, WA USA. RP Bailey, CG (reprint author), Victoria Univ Wellington, Sch Math & Comp Sci, POB 600, Wellington, New Zealand. NR 13 TC 0 Z9 0 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0002-5240 J9 ALGEBRA UNIV JI Algebr. Universalis PY 2003 VL 49 IS 2 BP 129 EP 158 DI 10.1007/s00012-003-1812-30 PG 30 WC Mathematics SC Mathematics GA 719KD UT WOS:000185201500003 ER PT S AU Doerry, AW Dickey, FM Romero, LA AF Doerry, AW Dickey, FM Romero, LA BE Zelnio, EG Garber, FD TI Windowing functions for SAR data with spectral gaps SO ALGORITHM FOR SYNTHETIC APERTURE RADAR IMAGERY X SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Algorithms for Synthetic Aperture Radar Imagery X CY APR 21-23, 2003 CL ORLANDO, FL SP SPIE DE SAR; radar; image; window functions; spectral gaps ID SPHEROIDAL WAVE-FUNCTIONS; FOURIER-ANALYSIS; UNCERTAINTY AB Synthetic Aperture Radar systems are being driven to provide images with ever-finer resolutions. This, of course, requires ever-wider bandwidths to support these resolutions in a number of frequency bands across the microwave (and lower) spectrum. The problem is that the spectrum is already quite crowded with a multitude of users, and a multitude of uses. For a radar system, this manifests itself as a number of 'stay-out' zones in the spectrum mandated by regulatory agencies; frequencies where the radar is not allowed to transmit. Even frequencies where the radar is allowed to transmit might be corrupted by interference from other legitimate (and/or illegitimate) users, rendering these frequencies useless to the radar system. In a SAR image, these spectral holes (by whatever source) degrade images, most notably by increasing objectionable sidelobe levels, most evident in the neighborhood of bright point-like objects. For contiguous spectrums, sidelobes in SAR images are controlled by employing window functions. However, those windows that work well for contiguous spectrums don't seem to work well for spectrums with significant gaps or holes. In this paper we address the question "Can some sorts of window functions be developed and employed to advantage when the spectrum is not contiguous, but contains significant holes or gaps?" A window function that minimizes sidelobe energy can be constructed based on prolate spheroidal wave functions. This approach is extended to accommodate spectral notches or holes, although the guaranteed minimum sidelobe energy can be quite high in this case. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP POB 5800,MS 0529, Albuquerque, NM 87185 USA. EM awdoerr@sandia.gov; fmdicke@sandia.gov; lromero@sandia.gov NR 19 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4955-5 J9 PROC SPIE PY 2003 VL 5095 BP 54 EP 65 DI 10.1117/12.487265 PG 12 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX63A UT WOS:000185937600007 ER PT S AU Richards, JA Bow, WJ Bray, BK AF Richards, JA Bow, WJ Bray, BK BE Zelnio, EG Garber, FD TI An informative confidence metric for ATR SO ALGORITHM FOR SYNTHETIC APERTURE RADAR IMAGERY X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms for Synthetic Aperture Radar Imagery X CY APR 21-23, 2003 CL ORLANDO, FL SP SPIE DE ATR; confidence metric; reliability; performance analysis; high-confidence identification AB Automatic or assisted target recognition (ATR) is an important application of synthetic aperture radar (SAR). Most ATR researchers have focused on the core problem of declaration-that is, detection and identification of targets of interest within a SAR image. For ATR declarations to be of maximum value to an image analyst, however, it is essential that each declaration be accompanied by a reliability estimate or confidence metric. Unfortunately, the need for a clear and informative confidence metric for ATR has generally been overlooked or ignored. We propose a framework and methodology for evaluating the confidence in an ATR system's declarations and competing target hypotheses. Our proposed confidence metric is intuitive, informative, and applicable to a broad class of ATRs. We demonstrate that seemingly similar ATRs may differ fundamentally in the ability-or inability-to identify targets with high confidence. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Richards, JA (reprint author), POB 5800 MS 0844, Albuquerque, NM 87185 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4955-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 5095 BP 336 EP 348 DI 10.1117/12.487670 PG 13 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX63A UT WOS:000185937600035 ER PT S AU Eidenbenz, S Pagourtzis, A Widmayer, P AF Eidenbenz, S Pagourtzis, A Widmayer, P BE Ibaraki, T Katoh, N Ono, H TI Flexible train rostering SO ALGORITHMS AND COMPUTATION, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 14th Annual International Symposium on Algorithms and Computation CY DEC 15-17, 2003 CL KYOTO, JAPAN SP Telecommun Advancement Fdn, Int Commun Fdn, Kansai Res Fdn Technol Promot, Casio Sci Promot Fdn AB Determining cost-effective vehicle scheduling is an important optimization issue in mass transportation networks. An interesting question in this context is whether allowing certain flexibility in the departure times of scheduled routes may reduce the number of vehicles needed. We formulate this question as the FLEXIBLE TRAIN ROSTERING(1) problem. We consider two cases that are of practical interest: Unlimited flexibility: only the durations of routes are given and we are free to determine the most appropriate departure time for each route. Limited flexibility: initial departure times are given, together with a delay threshold epsilon; we are asked to determine the most appropriate delay less than or equal to epsilon for each route. We also consider variants where we are allowed to use empty rides, (i.e., routes without passengers). We present a variety of results for these problems: polynomial-time algorithms that optimally solve some of them, NP- and APX-hardness proofs for others, as well as approximation algorithms for most of the hard problems. C1 Los Alamos Natl Lab, Basic & Appl Simulat Sci CCS 5, Los Alamos, NM 87545 USA. Natl Tech Univ Athens, Sch Elect & Comp Engn, Athens, Greece. ETH, Inst Theoret Comp Sci, Zurich, Switzerland. RP Los Alamos Natl Lab, Basic & Appl Simulat Sci CCS 5, Los Alamos, NM 87545 USA. EM eidenben@lanl.gov; pagour@cs.ntua.gr; widmayer@inf.ethz.ch NR 12 TC 1 Z9 1 U1 1 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-20695-7 J9 LECT NOTES COMPUT SC PY 2003 VL 2906 BP 615 EP 624 PG 10 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA BY20N UT WOS:000188242500063 ER PT S AU Sheen, DM Gallagher, NB Sharpe, SW Anderson, KK Schultz, JF AF Sheen, DM Gallagher, NB Sharpe, SW Anderson, KK Schultz, JF BE Shen, SS Lewis, PE TI Impact of background and atmospheric variability on infrared hyperspectral chemical detection sensitivity SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE hyperspectral imaging; chemical detection; infrared ID RESOLUTION; GAS AB Chemical detection using infrared hyperspectral imaging systems often is limited by the effects of variability of the scene background emissivity spectra and temperature. Additionally, the atmospheric up-welling and down-welling radiance and transmittance are difficult to estimate from the hyperspectral image data, and may vary across the image. In combination, these background variability effects are referred to as "clutter." A study has been undertaken at Pacific Northwest National Laboratory to determine the relative impact of atmospheric variability and background variability on the detection of trace chemical vapors. This study has analyzed Atmospheric Emitted Radiance Interferometer data to estimate fluctuations in atmospheric constituents. To allow separation of the effects of background and atmospheric variability, hyperspectral data were synthesized using large sets of simulated atmospheric spectra, measured background emissivity spectra, and measured high-resolution gas absorbance spectra. The atmosphere was simulated using FASCODE in which the constituent gas concentrations and temperatures were varied. These spectral sets were combined synthetically using a physics model to realize a statistical synthetic scene with a plume present in a portion of the image. Noise was added to the image with the level determined by a numerical model of the hyperspectral imaging instrument. The chemical detection performance was determined by applying a matched-filter estimator to both the on-plume and off-plume regions. The detected levels in the off-plume region were then used to determine the noise equivalent concentration path length (NECL), a measure of the chemical detection sensitivity. The NECL was estimated for numerous gases and for a variety of background and atmospheric conditions to determine the relative impact of instrument noise, background variability, and atmospheric variability. C1 US DOE, Battelle Mem Inst, Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sheen, DM (reprint author), US DOE, Battelle Mem Inst, Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. OI Anderson, Kevin/0000-0001-5613-5893 NR 11 TC 5 Z9 5 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5093 BP 218 EP 229 DI 10.1117/12.488931 PG 12 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900022 ER PT S AU Theiler, J Cai, DM AF Theiler, J Cai, DM BE Shen, SS Lewis, PE TI Resampling approach for anomaly detection in multispectral images SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE anomaly detection; machine learning; multispectral imagery ID SUPPORT; CLASSIFIERS AB We propose a novel approach for identifying the "most unusual" samples in a data set, based on a resampling of data attributes. The resampling produces a "background class" and then binary classification is used to distinguish the original training set from the background. Those in the training set that are most like the background (i.e., most unlike the rest of the training set) are considered anomalous. Although by. their nature, anomalies do not permit a positive definition (if I knew what they were, I wouldn't call them anomalies), one can make "negative definitions" (I can say what does not qualify as an interesting anomaly). By choosing different resampling schemes, one can identify different kinds of anomalies. For multispectral images, anomalous pixels correspond to locations on the ground with unusual spectral signatures or, depending on how feature sets are constructed, unusual spatial textures. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Theiler, J (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 20 Z9 20 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5093 BP 230 EP 240 DI 10.1117/12.487069 PG 11 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900023 ER PT S AU Galbraith, A Theiler, J Bender, S AF Galbraith, A Theiler, J Bender, S BE Shen, SS Lewis, PE TI Resampling methods for the MTI coregistration product SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE MTI; multispectral; imagery; resampling AB Accurate coregistration of images from the Multispectral Thermal Imager (MTI) is needed to properly align bands for spectral analysis and physical retrievals, such as water surface temperature, land-cover classification, or small target identification. After accounting for spacecraft motion, optical distortion, and geometrical perspective, the irregularly-spaced pixels in the images must be resampled to a common grid. What constitutes an optimal resampling depends, to some extent, on the needs of the user. A good resampling trades off radiometric fidelity, contrast preservation for small objects, and cartographic accuracy - and achieves this compromise without unreasonable computational effort. The standard MTI coregistration product originally used a weighted-area approach to achieve this irregular resampling, which generally over-smoothes the imagery and reduces the contrast of small objects. Recently, other resampling methods have been implemented to improve the final coregistered image. These methods include nearest-neighbor resampling and a tunable, distance-weighted resampling. We will discuss the pros and cons of various resampling methods applied to MTI images, and show results of comparing the contrast of small objects before and after resampling. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Space & Remote Sensing Sci, POB 1663, Los Alamos, NM 87545 USA. EM amyg@lanl.gov; jt@lanl.gov; sbender@lanl.gov NR 18 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 PROC SPIE PY 2003 VL 5093 BP 283 EP 293 DI 10.1117/12.485985 PG 11 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900028 ER PT S AU Pope, P Theiler, J AF Pope, P Theiler, J BE Shen, SS Lewis, PE TI Automated Image Registration (AIR) of MTI imagery SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE MTI; image; multispectral; registration; correlation; reciprocity; weighted least squares AB This paper describes an algorithm for the registration of imagery collected by the Multispectral Thermal Imager (MTI). The Automated Image Registration (AIR) algorithm is entirely image-based and is implemented in an automated fashion, which avoids any requirement for human interaction. The AIR method differs from the "direct georeferencing" method used to create our standard coregistered product since explicit information about the satellite's trajectory and the sensor geometry are not required. The AIR method makes use of a maximum cross-correlation (MCC) algorithm, which is applied locally about numerous points within any two images being compared. The MCC method is used to determine the row and column translations required to register the bands of imagery collected by a single SCA (band-to-band registration), and the row and column translations required to register the imagery collected by the three SCAs for any individual band (SCA-to-SCA registration). Of particular note is the use of reciprocity and a weighted least squares approach to obtaining the band-to-band registration shifts. Reciprocity is enforced by using the MCC method to determine the row and column translations between all pair-wise combinations of bands. This information is then used in a weighted least squares approach to determine the optimum shift values between an arbitrarily selected reference band and the other 15 bands. The individual steps of the AIR methodology, and the results of registering MTI imagery through use of this algorithm, are described. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci, Los Alamos, NM 87545 USA. RP Theiler, J (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 9 Z9 9 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5093 BP 294 EP 305 DI 10.1117/12.485702 PG 12 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900029 ER PT S AU Salazar, JS Smith, JL AF Salazar, JS Smith, JL BE Shen, SS Lewis, PE TI Nonparametric image segmentation applied to Multispectral Thermal Imager data SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE MTI; multispectral; thermal; imager; image; segmentation; clustering; classification AB The Multispectral Thermal Imager (MTI) provides a highly informative source of remote sensing data. However, the analysis and exploitation can be very challenging. Effective utilization of this imagery by an image analyst typically requires a consistent and timely means of locating regions of interest. Many available image analysis/segmentation techniques are often slow, not robust to spectral variabilities from view to view or within a spectrally similar region, C, and/or require a significant amount of user intervention to achieve a segmentation corresponding to self-similar regions within the data. This paper discusses a segmentation approach that exploits the gross spectral shape of MTI data. In particular, we propose a nonparametric approach to perform coarse level segmentation that can stand alone or as a potential precursor to other image analysis tools. In comparison to previous techniques, the key characteristics of this approach are in its simplicity, speed, and consistency. Most importantly it requires relatively, few user inputs and determines the number of clusters, their extent, and, data assignment directly from the data. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Salazar, JS (reprint author), Sandia Natl Labs, MS 0844,POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5093 BP 306 EP 319 DI 10.1117/12.488532 PG 14 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900030 ER PT S AU Villa-Aleman, E Kurzeja, RJ Pendergast, MM AF Villa-Aleman, E Kurzeja, RJ Pendergast, MM BE Shen, SS Lewis, PE TI Temporal, spatial, and spectral variability at the Ivanpah Playa vicarious calibration site SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE MTI satellite; calibration; Ivanpah Playa AB The Savannah River Technology Center (SRTC) conducted four reflectance vicarious calibrations at Ivanpah Playa, California since July 2000 in support of the MTI satellite. The multi-year study shows temporal, spatial and spectral variability at the playa. The temporal variability in the wavelength dependent reflectance and emissivity across the playa suggests a dependency witt precipitation during the winter and early spring seasons. Satellite imagery acquired on September and November 2000, May 2001 and March 2002 in conjunction with ground truth during the September, May and March campaigns and water precipitation records were used to demonstrate the correlation observed at the playa. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Villa-Aleman, E (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Bldg 735A,D Wing, Aiken, SC 29808 USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5093 BP 320 EP 330 DI 10.1117/12.486960 PG 11 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900031 ER PT S AU Villa-Aleman, E Kurzeja, RJ Pendergast, MM AF Villa-Aleman, E Kurzeja, RJ Pendergast, MM BE Shen, SS Lewis, PE TI Assessment of Ivanpah Playa as a site for thermal vicarious calibration for the MTI satellite SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL AND ULTRASPECTRAL IMAGERY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery IX CY APR 21-24, 2003 CL ORLANDO, FL SP SPIE DE MTI; satellite; calibration; Ivanpah Playa AB The Savannah River Technology Center (SRTC) conducted four vicarious reflectance calibrations at Ivanpah Playa, California since July 2000 in support of the MTI satellite. The potential of the playa as a thermal calibration site was also investigated in the campaigns with a mobile Fourier transform infrared spectrometer. The multi-year study shows time and spatial variability in the spectral emissivity. The ground truth temperature and emissivity correlate quite well with the data from the MTI satellite imagery. The research paper will show the time-dependent emissivities measured during our ground truth campaigns and the corresponding satellite imagery. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Villa-Aleman, E (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Bldg 725A,D Wing, Aiken, SC 29808 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4953-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5093 BP 331 EP 342 DI 10.1117/12.485801 PG 12 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BX79U UT WOS:000186472900032 ER PT S AU Chen, ZZ Jiang, T Lin, GH Rizzi, R Wen, JJ Xu, D Xu, Y AF Chen, ZZ Jiang, T Lin, GH Rizzi, R Wen, JJ Xu, D Xu, Y BE DiBattista, G Zwick, U TI More reliable protein NMR peak assignment via improved 2-interval scheduling SO ALGORITHMS - ESA 2003, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 11th Annual European Symposium on Algorithms CY SEP 16-19, 2003 CL BIDAPEST, HUNGARY SP European Assoc Theoret Comp Sci, Hungarian Acad Sci, Hungarian Natl Fdn Sci, Univ Szeged, Inst Informat AB Protein NMR peak assignment refers to the process of assigning a group of "spin systems" obtained experimentally to a protein sequence of amino acids. The automation of this process is still an unsolved and challenging problem in NMR protein structure determination. Recently, protein backbone NMR peak assignment has been formulated as an interval scheduling problem, where a protein sequence P of amino acids is viewed as a discrete time interval I (the amino acids on P one-to-one correspond to the time units of I), each subset S of spin systems that are known to originate from consecutive amino acids of P is viewed as a "job" js, the preference of assigning S to a subsequence P of consecutive amino acids on P is viewed as the profit of executing job js in the subinterval of I corresponding to P, and the goal is to maximize the total profit of executing the jobs (on a single machine) during I. The interval scheduling problem is Max SNP-hard in general. Typically the jobs that require one or two consecutive time units are the most difficult to assign/schedule. To solve these most difficult assignments, we present an efficient (13)/(7)-approximation algorithm. Combining this algorithm with a greedy filtering strategy for handling long jobs (i. e. jobs that need more than two consecutive time units), we obtained a new efficient heuristic for protein NMR peak assignment. Our study using experimental data shows that the new heuristic produces the best peak assignment in most of the cases, compared with the NMR peak assignment algorithms in the literature. The (13)/(7)-approximation algorithm is also the first approximation algorithm for a nontrivial case of the classical (weighted) interval scheduling problem that breaks the ratio 2 barrier. C1 Tokyo Denki Univ, Dept Math Sci, Hatoyama, Saitama 3500394, Japan. Univ Calif Riverside, Dept Comp Sci, Riverside, CA 92521 USA. Univ Alberta, Dept Comp Sci, Edmonton, AB T6G 2E8, Canada. Univ Trent, Dipartimento Informat & Telecomun, Trent, Italy. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Chen, ZZ (reprint author), Tokyo Denki Univ, Dept Math Sci, Hatoyama, Saitama 3500394, Japan. RI Rizzi, Romeo/J-4224-2012; OI Rizzi, Romeo/0000-0002-2387-0952 NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-20064-9 J9 LECT NOTES COMPUT SC PY 2003 VL 2832 BP 580 EP 592 PG 13 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BY05J UT WOS:000187420300053 ER PT B AU Cieliebak, M Eidenbenz, S Penna, P AF Cieliebak, M Eidenbenz, S Penna, P BE Benson, G Page, R TI Noisy data make the partial digest problem NP-hard SO ALGORITHMS IN BIOINFORMATICS, PROCEEDINGS SE LECTURE NOTES IN BIOINFORMATICS LA English DT Article; Proceedings Paper CT 3rd International Workshop on Algorithms in Bioinformatics CY SEP 15-20, 2003 CL BUDAPEST, HUNGARY AB The problem to find the coordinates of n points on a line such that the pairwise distances of the points form a given multi-set of (n 2) distances is known as PARTIAL DIGEST problem, which occurs for instance in DNA physical mapping and de novo sequencing of proteins. Although PARTIAL DIGEST was - as a combinatorial problem - already proposed in the 1930's, its computational complexity is still unknown. In an effort to model real-life data, we introduce two optimization variations of PARTIAL DIGEST that model two different error types that occur in real-life data. First, we study the computational complexity of a minimization version Of PARTIAL DIGEST in which only a subset of all pairwise distances is given and the rest are lacking due to experimental errors. We show that this variation is NP-hard to solve exactly. This result answers an open question posed by Pevzner (2000). We then study a maximization version Of PARTIAL DIGEST where a superset of all pairwise distances is given, with some additional distances due to inaccurate measurements. We show that this maximization version is NP-hard to approximate to within a factor of \D\(1/2-epsilon) for any epsilon > 0, where \D\ is the number of input distances. This inapproximability result is tight up to low-order terms as we give a trivial approximation algorithm that achieves a matching approximation ratio. C1 ETH, Inst Theoret Comp Sci, Zurich, Switzerland. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cieliebak, M (reprint author), ETH, Inst Theoret Comp Sci, Zurich, Switzerland. EM cieliebak@inf.ethz.ch; eidenben@lanl.gov; penna@inf.ethz.ch NR 27 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-20076-2 J9 LECT N BIOINFORMAT PY 2003 VL 2812 BP 111 EP 123 PG 13 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Genetics & Heredity; Mathematics, Interdisciplinary Applications SC Computer Science; Genetics & Heredity; Mathematics GA BY27N UT WOS:000188697400009 ER PT B AU Jones, RH Windisch, CF AF Jones, RH Windisch, CF BE Das, SK TI Stress corrosion cracking of lightweight automotive materials SO ALUMINUM 2003 LA English DT Proceedings Paper CT Symposium on Aluminum held at the TMS 2003 Annual Meeting CY MAR 02-06, 2003 CL SAN DIEGO, CA SP Minerals, Met & Mat Soc ID ALLOY; MG AB Stress corrosion cracking can be eliminated or controlled with a knowledge of the material and environmental conditions that cause it. For lightweight automotive materials such as Al-Mg and Mg-Al alloys, grain boundary chemistry and microstructure play a key role in stress corrosion cracking. Precipitation of the Mg rich beta-phase (Al3Mg2) at grain boundaries of Al-Mg alloys and the gamma-phase (Mg17Al12) at grain boundaries of the Mg-Al alloys are critical factors in their stress corrosion performance. In Mg-Al, the gamma-phase is cathodic to the matrix while in the Al-Mg case, the beta-phase is anodic to the matrix. These phases produce localized galvanic induced-corrosion that leads to intergranular stress corrosion cracking and cracking growth rates of 5 to 10(3) times faster than the solution treated condition, for Al-Mg and Mg-Al, respectively. Utilization of these alloys for automotive applications will require some precautions such as assuring that the Al-Mg alloys are in the solution treated and quenched conditions and not used in applications where the temperature will reach 150degreesC for extended periods while the Mg-Al alloys will likely require corrosion protection. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Jones, RH (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-542-5 PY 2003 BP 43 EP 54 PG 12 WC Engineering, Mechanical; Metallurgy & Metallurgical Engineering; Transportation Science & Technology SC Engineering; Metallurgy & Metallurgical Engineering; Transportation GA BX66P UT WOS:000186057900005 ER PT B AU Robinson, T AF Robinson, T BE Das, SK TI Aluminum industry research and development partnerships US department of energy, industrial technologies program SO ALUMINUM 2003 LA English DT Proceedings Paper CT Symposium on Aluminum held at the TMS 2003 Annual Meeting CY MAR 02-06, 2003 CL SAN DIEGO, CA SP Minerals, Met & Mat Soc C1 US DOE, Washington, DC USA. RP Robinson, T (reprint author), US DOE, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-542-5 PY 2003 BP 205 EP 214 PG 10 WC Engineering, Mechanical; Metallurgy & Metallurgical Engineering; Transportation Science & Technology SC Engineering; Metallurgy & Metallurgical Engineering; Transportation GA BX66P UT WOS:000186057900020 ER PT J AU Felmy, AR Mason, MJ Gassman, PL McCready, DE AF Felmy, AR Mason, MJ Gassman, PL McCready, DE TI The formation of Sr silicates at low temperature and the solubility product of tobermoritelike Sr5Si6O16(OH)(2)center dot 5H(2)O SO AMERICAN MINERALOGIST LA English DT Article ID HIGH-IONIC-STRENGTH; AQUEOUS-SOLUTION; NATURAL-WATERS; CALCIUM; HYDRATE; MODEL; MICROSTRUCTURE; PRECIPITATION; 25-DEGREES-C; SYNCHROTRON AB The aqueous phase interaction of divalent Sr with silicate-containing solutions was studied over a range of pH values, dissolved silica, and Sr concentrations, and extending to basic solution (0.2 M NaOH) at room temperature (22-23 degreesC). Formation of an amorphous Sr silicate phase of variable composition was observed, beginning at approximately pH 10. The precipitate became quasi-crystalline at higher base concentrations and with aging time. The phase that formed at high base concentration (beginning at pH 11.5-12.0) was identified by total chemical analysis, X-ray diffraction, and thermogravimetric analysis to have a chemical formula of Sr5Si6O16(OH)(2).5H(2)O, with a tobermorite-like structure. The Sr5Si6O16(OH)(2).5H(2)O phase has not been previously reported. Scanning electron microscopy (SEM) analysis of alcohol-washed precipitates showed a fine granular structure similar to Ca silicate hydrates. De-ionized water washing of the precipitates resulted in dissolution and growth of surface phases with the classical "sheaf of wheat" nucleation structure previously identified only for Ca silicate hydrates. Solubility studies of the precipitates, which extended to 286 days of equilibration, yielded an estimate of the solubility product of quasicrystalline, tobermorite-like Sr silicate of Log K = -38.0 +/- 0.7 for the overall reaction, 5H(2)O + Sr5Si6O16(OH)(2).5H(2)O = 5Sr(2+) + 6H(3)SiO(4)(-) + 4OH(-). The first estimate of the association constant for the species SrH2SiO4(aq) of Log K = 2.86 was also made. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Felmy, AR (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, 3335 Q Ave, Richland, WA 99352 USA. EM ar.felmy@pnl.gov NR 29 TC 5 Z9 5 U1 1 U2 3 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD JAN PY 2003 VL 88 IS 1 BP 73 EP 79 PG 7 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 635DV UT WOS:000180383600009 ER PT J AU Sharp, ZD Papike, JJ Durakiewicz, T AF Sharp, ZD Papike, JJ Durakiewicz, T TI The effect of thermal decarbonation on stable isotope compositions of carbonates SO AMERICAN MINERALOGIST LA English DT Article ID MARTIAN METEORITE ALH84001; PHOSPHORIC-ACID; OXYGEN; FRACTIONATION; MAGNETITE; TEMPERATURE; LIFE; MARS AB Oxygen and C isotope compositions of CO2 gas released by thermal decomposition of siderite, calcite, and dolomite were measured using a new "real-time" continuous-flow technique to determine whether fractionation associated with simple thermal decarbonation could explain the large isotopic variations and mineralogy such as those found in the ALH84001 meteorite. Oxygen and C isotope fractionation between calcite or dolomite and evolved CO2 gas during thermal decarbonation in a 3 bar He pressure environment is very small. The delta(13)C and delta(18)O values of evolved CO2 gas are nearly identical to those of the carbonate, very different from the calculated equilibrium Delta(18)O(calcite-CO2) value of -4 to -5parts per thousand at 800-900 degreesC or from previous experimental results of decarbonation in vacuum. The kinetic Delta(18)O(siderite-CO2) values are similar to-2parts per thousand, whereas Delta(13)C(siderite-CO2) values increase logarithmically with time, from similar to1parts per thousand for the earliest stages of decarbonation to >5parts per thousand in the final stages. Incomplete siderite decomposition produces both magnetite (delta(18)O = 3.5parts per thousand SMOW) and minor graphite. CO and O-2 were detected during the decarbonation process. The data can be explained by simultaneous oxidation and reduction by the reaction: 6FeCO(3) --> 2Fe(3)O(4) + 2x CO + 4y CO2 + (6 - 2x - 4y) C + (5 - x - 4y) O-2, where x and y are between 0 and 1. Siderite decomposition in the presence of H-2 gas produces wustite and Fe metal in place of oxidized Fe minerals. The experiments in this study are not a perfect analog for possible decarbonation conditions that might have occurred to the carbonates in ALH84001. Nevertheless, the large VC and 6110 variations observed in ALH84001 (greater than or equal to10parts per thousand for O) are significantly larger than those expected by thermal decarbonation, suggesting instead a low-temperature mechanism for their formation. C1 Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Univ New Mexico, Inst Meteorit Earth & Planetary Sci, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. Marie Curie Sklodowska Univ, Mass Spect Lab, Inst Phys, PL-20031 Lublin, Poland. RP Sharp, ZD (reprint author), Univ New Mexico, Dept Earth & Planetary Sci, Northrop Hall, Albuquerque, NM 87131 USA. OI Durakiewicz, Tomasz/0000-0002-1980-1874 NR 24 TC 18 Z9 19 U1 0 U2 8 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JAN PY 2003 VL 88 IS 1 BP 87 EP 92 PG 6 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 635DV UT WOS:000180383600011 ER PT J AU Post, JE Heaney, PJ Hanson, J AF Post, JE Heaney, PJ Hanson, J TI Synchrotron X-ray diffraction study of the structure and dehydration behavior of todorokite SO AMERICAN MINERALOGIST LA English DT Article ID OCTAHEDRAL MOLECULAR-SIEVES; MANGANESE OXIDE; RIETVELD REFINEMENT; POWDER DIFFRACTION; CATION DISPLACEMENTS; CRYPTOMELANE; HOLLANDITES; CATALYSTS; NODULES; IONS AB Real-time, temperature-resolved synchrotron powder X-ray diffraction data and Rietveld refinements were used to investigate the behavior of the todorokite structure from 100 to 820 K. At 298 K, the lower valence cations, such as Mn3+, occupy large octahedral sites at the edges of the triple chains, and four water/cation sites are in the tunnels. In our heating experiments in vacuum, todorokite began to break down at similar to450 K and fully decomposed by 620 K, at which point hausmannite started to form. Our results suggest that the loss Of O-2 accompanied the reduction of Mn4+ to Mn3+ and Mn2+, and these reactions impelled a breakdown of the octahedral framework and the subsequent release of the tunnel water molecules. Rierveld refinements revealed a gradual thermal expansion of the todorokite structure to similar to450 K. At higher temperatures, the unit-cell volume gradually decreased, primarily as a result of a decrease in c, and the decline in beta with increasing temperature was accelerated. A mechanism for forming the inverse spinel hausmannite structure from todorokite is presented. C1 Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11793 USA. RP Post, JE (reprint author), Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. EM post.jeffrey@nmnh.si.edu RI Hanson, jonathan/E-3517-2010 NR 33 TC 36 Z9 41 U1 3 U2 12 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD JAN PY 2003 VL 88 IS 1 BP 142 EP 150 PG 9 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 635DV UT WOS:000180383600017 ER PT J AU Hou, XQ Bish, DL Wang, SL Johnston, CT Kirkpatrick, RJ AF Hou, XQ Bish, DL Wang, SL Johnston, CT Kirkpatrick, RJ TI Hydration, expansion, structure, and dynamics of layered double hydroxides SO AMERICAN MINERALOGIST LA English DT Article ID HYDROTALCITE-LIKE COMPOUNDS; INTERLAYER MOLECULAR-STRUCTURE; MONTE-CARLO SIMULATION; SWELLING CLAY-MINERALS; ANION-EXCHANGE; ION-EXCHANGE; INTERCALATION COMPOUNDS; CRYSTAL-CHEMISTRY; THERMAL-STABILITY; X-RAY AB Water-vapor sorption isotherms, relative humidity (RH) controlled powder X-ray diffraction (XRD) data, and new and previously published multi-nuclear NMR spectroscopic data for a wide range of layered double hydroxides (LDHs) provide greatly increased understanding of the effects of hydration state on the structure and dynamical behavior of interlayer and surface anions and the factors controlling the expansion behavior of this group of minerals. Li,Al and Mg,Al LDH phases containing SO42-, SeO42-, PO43-, HPO42-, MoO42-, ClO4-, SeO32-, CO32-, F-, Cl-, Br-, I-, OH-, and NO3- were examined. The phases studied can be grouped into three types based on basal spacing expansion, water sorption, and interlayer anion dynamics: Type 1, significantly expandable (1.5-3.0 Angstrom); Type 2, slightly expandable (expansion <0.5 Angstrom) and with significant interlayer water exchange; and Type 3, essentially non-expandable (0-0.2 Angstrom) and with little interlayer water exchange. For Type 1, the fully expanded phases have a two-water layer structure, and the phase transition from one layer to two layers as determined by XRD consistently correlates with a significant step in the water sorption isotherm and with changes in the interlayer structure and dynamics as observed by NMR spectroscopy. For Type-2 phases, only one-water layer structures form, and the interlayer anions may undergo dynamical disordering with increasing RH, as observed by NMR. For both Types I and 2, the first water layer does not cause significant basal spacing expansion due to occupancy of vacant interstitial sites between the anions by the water molecules. For Type-3 phases, there is little interlayer water sorption because the interlayers are essentially closed due to the small size or planar shape of the anions and their strong electrostatic and hydrogen bonding interaction with the hydroxyl layers. RH has no effect on the structural environments and dynamics of the interlayer anions in this group. C1 Univ Illinois, Dept Geol, Urbana, IL 61801 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Purdue Univ, Dept Agron, W Lafayette, IN 47907 USA. RP Hou, XQ (reprint author), Univ Illinois, Dept Geol, 245 NHB,1301 W Green St, Urbana, IL 61801 USA. RI Wang, Shan-Li/C-6016-2008; Johnston, Cliff/B-2215-2009 OI Wang, Shan-Li/0000-0003-3156-5365; Johnston, Cliff/0000-0002-8462-9724 NR 61 TC 60 Z9 62 U1 9 U2 37 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JAN PY 2003 VL 88 IS 1 BP 167 EP 179 PG 13 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 635DV UT WOS:000180383600020 ER PT J AU Groat, LA Chakoumakos, BC Brouwer, DH Hoffman, CM Fyfe, CA Morell, H Schultz, AJ AF Groat, LA Chakoumakos, BC Brouwer, DH Hoffman, CM Fyfe, CA Morell, H Schultz, AJ TI The amblygonite (LiAlPO4F)-montebrasite (LiAlPO4OH) solid solution: A combined powder and single-crystal neutron diffraction and solid-state Li-6 MAS, CP MAS, and REDOR NMR study SO AMERICAN MINERALOGIST LA English DT Article ID DISTANCE DETERMINATIONS; CROSS-POLARIZATION; FLUORINE AB The amblygonite-montebrasite series of minerals, common constituents of granitic pegmatites and topaz-bearing granites, show complete solid solution with ideal composition LiAlPO4(F, OH). These compounds are ideal for studying F <----> OH solid solution in minerals because natural members of the series generally show little deviation from the ideal composition. In this study, we used powder and single-crystal neutron diffraction and solid-state Li-6 MAS, CP MAS, and REDOR NMR techniques to study the effect of F <----> OH substitution on the series. Lattice parameters refined from single-crystal neutron diffraction data show increasing b and decreasing a, c, and V with increasing F/(F + OH). The volume is highest for the OH end-member because of the presence of an additional atom (H). The a and c parameters decrease with increasing F/(F + OH) because the O-H vector is close to the a-c plane and the Al-OH/F vectors are approximately parallel to c. Lattice parameters refined from neutron powder diffraction patterns collected at lower T show that thermal contraction increases with F/(F + OH), presumably because the F anion takes up less space than the OH molecule. The results show that the OH/F position is always fully occupied. The H displacement ellipsoid shows little change with occupancy, which obviously corresponds negatively with increasing F/(F + OH). However, the Li displacement ellipsoid becomes extremely large and anisotropic with increasing F fraction. Most of the distortion is associated with the U-3 eigenvalue, which lies between the c and c* directions. U-eq values corresponding to the Li atom show a greater reduction with decreasing temperature than the other atoms. The temperature dependence of Li is the same regardless of F content. Even when extrapolated to absolute zero the Li displacement ellipsoid is very large, which implies a large static disorder. At the montebrasite end of the series, there are five short Li-phi (phi = O, OH, F) distances and one very long Li-O4 bond. With increasing F content, the Li-O4 distance decreases and the Li-O3f distance increases, such that at the amblygonite end, the coordination is 4 + 2. The disorder in the Li site is obviously caused by the substitution of F for OH. The driving force is the loss of the hydrogen bond to 04, which causes the Li-O4 bond to strengthen and improves the bond valence to O4. The results show that the H atom position is imbedded within the distorted octahedral oxygen coordination of the Li atom. To represent the disorder better, we used a split Li site model. The results show that Li1 occupancy increases and the Li2 occupancy decreases with increasing F content, and that the Li1-Li2 distance is longer for intermediate compositions than for the end-members. The Li-6 MAS NMR experiments provide important structural information complementary to the neutron diffraction results. The spectra of samples in the amblygonite-montebrasite series show two well-resolved peaks, confirming the presence of Li disorder over two distinct sites, and highly resolved Li-6 MAS NMR spectra are obtained at the very high magnetic field strength of 18.8 T. The peaks at -0.3 ppm and -0.9 ppm were unambiguously assigned to the Li2(OH) and Li1(F) sites found in the neutron diffraction structures. The isotropic chemical shifts are consistent with the coordinations of these Li sites found in the neutron diffraction structures. The relative intensities of the two peaks across the series of samples reflect the varying F/(F + OH). In addition to confirming the assignments of the peaks, it is possible to measure H-Li2 and F-Li1 internuclear distances by Li-6 {H-1} and Li-6 {F-19} CP and REDOR NMR that are consistent with the corresponding distances from the neutron diffraction structures. The Li-6 {H-1} and Li-6 {F-19} CP and REDOR results indicate that the Li disorder is random throughout the crystals rather than over large domains, a conclusion that cannot be made from diffraction experiments. Variable temperature Li-6 MAS NMR spectra confirm that the disorder is static and there is no dynamic exchange involving F, OH, or Li. Each Li ion has access to only one of the two observed sites as determined by the presence of either OH or F in its immediate environment and there is no possibility of a dynamic exchange. C1 Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V6T 1Z4, Canada. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada. Argonne Natl Lab, Argonne, IL 60439 USA. RP Univ British Columbia, Dept Earth & Ocean Sci, 6339 Stores Rd, Vancouver, BC V6T 1Z4, Canada. EM lgroat@eos.ubc.ca RI Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 29 TC 17 Z9 17 U1 0 U2 13 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD JAN PY 2003 VL 88 IS 1 BP 195 EP 210 PG 16 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 635DV UT WOS:000180383600023 ER EF