FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Striebel, K Guerfi, A Shim, J Armand, M Gauthier, M Zaghib, K AF Striebel, K Guerfi, A Shim, J Armand, M Gauthier, M Zaghib, K TI LiFePO4/gel/natural graphite cells for the BATT program SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 11th International Meeting on Lithium Batteries CY JUN 24-28, 2002 CL MONTEREY, CALIFORNIA DE LiFePO4/gel/natural graphite cells; BATT program; calendar life test AB LiFePO4/gel/natural graphite (NG) cells have been prepared and cycled under a fixed protocol for cycle and calendar life determination. Cell compression of 68 kPa was found to represent an optimal balance between cell impedance and the first cycle losses on the individual electrodes with the gel electrolyte. Cells with a Li anode showed capacities of 160 and 78 mAh/g LiFePO4 for C/25 and 2C discharge rates, respectively. Rapid capacity and power fade were observed in the LiFePO4/gel/NG cells during cycling and calendar life studies. Diagnostic evaluations point to the consumption of cycleable Li though a side reaction as the reason for performance fade with minimal degradation of the individual electrodes. Published by Elsevier Science B.V. C1 Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Inst Rech Hydro Quebec, Varennes, PQ J3X 1S1, Canada. Univ Montreal, Dept Chim, CNRS, Joint Int Lab,UdM,UMR 2289, Montreal, PQ H3C 3J7, Canada. RP Striebel, K (reprint author), Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 3 TC 51 Z9 52 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUN 1 PY 2003 VL 119 SI SI BP 951 EP 954 DI 10.1016/S0378-7753(03)00295-7 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 694XC UT WOS:000183799600179 ER PT J AU Shim, J Striebel, KA AF Shim, J Striebel, KA TI Cycling performance of low-cost lithium ion batteries with natural graphite and LiFePO4 SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 11th International Meeting on Lithium Batteries CY JUN 24-28, 2002 CL MONTEREY, CALIFORNIA DE lithium-ion batteries; natural graphite; LiFePO4 ID SURFACE-CHEMISTRY; LI AB Low-cost lithium ion batteries with LiFePO4 and natural graphite were cycled in 1 M LiBF4 + EC/DEC at 100% depth of discharge and 25 degreesC in order to investigate cycle performance and diagnostics for capacity fading. The 12 cm(2) pouch cell showed 65% of capacity retention at 5C compared to that at C/25. The cell showed 80% of initial capacity after 80 cycles and its capacity fade rate was 11.3 muA h/cycle during constant C/2 cycling. In hybrid pulse power characterization, the discharge resistance of this cell was higher than commercial graphite/LiCoO2 cell because of low lithium diffusivity in LiFePO4. Slow rate cycling in pouch full cell showed almost 40% of capacity fade after 100 cycles. However, the 100-cycled cathode and anode did not show any capacity fading in half-cell test after disassembling full cell, suggesting that capacity fade in the full cell is caused by loss of cycleable Li. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Striebel, KA (reprint author), Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 11 TC 84 Z9 89 U1 7 U2 61 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUN 1 PY 2003 VL 119 SI SI BP 955 EP 958 DI 10.1016/S0378-7753(03)00297-0 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 694XC UT WOS:000183799600180 ER PT J AU Jones, CR AF Jones, CR TI Invited Editorial: The evolution of the system of radiological protection - evolution or expedition? SO JOURNAL OF RADIOLOGICAL PROTECTION LA English DT Editorial Material C1 Org Econ Cooperat & Dev, Nucl Energy Agcy Comm Radiat Protect & Publ Hlth, Paris, France. US DOE, Washington, DC USA. RP Jones, CR (reprint author), Org Econ Cooperat & Dev, Nucl Energy Agcy Comm Radiat Protect & Publ Hlth, Paris, France. NR 3 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0952-4746 J9 J RADIOL PROT JI J. Radiol. Prot. PD JUN PY 2003 VL 23 IS 2 BP 121 EP 124 DI 10.1088/0952-4746/23/2/002 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 705CD UT WOS:000184377900002 PM 12875544 ER PT J AU Schoonover, JR Zhang, SLL Johnston, CT AF Schoonover, JR Zhang, SLL Johnston, CT TI Raman spectroscopy and multivariate curve resolution of concentrated Al2O3-Na2O-H2O solutions SO JOURNAL OF RAMAN SPECTROSCOPY LA English DT Article DE Raman spectroscopy; multivariate curve resolution; aluminate ID ALUMINATE SOLUTIONS; SPECTRA; WATER; ION AB Multivariate curve resolution was applied to a series of Raman spectra for samples representing highly concentrated alkaline aluminate slurries. Factors are extracted that represent the behavior of the dominant chemical species present, including aluminate monomer, aluminate oligomers, water and hydroxide. The analysis is particularly useful in unraveling the numerous overlapping contributions in the v(OH) region of the spectrum. These extracted factors were further examined by comparing their scores with measured physiochemical properties such as density, relative humidity and molar concentrations of components, weight fractions and water activity. Published in 2003 by John Wiley Sons, Ltd. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Unilever Res, Edgewater, NJ 07020 USA. Purdue Univ, W Lafayette, IN 47907 USA. RP Schoonover, JR (reprint author), Los Alamos Natl Lab, Mail Stop E549, Los Alamos, NM 87545 USA. RI Johnston, Cliff/B-2215-2009 OI Johnston, Cliff/0000-0002-8462-9724 NR 19 TC 7 Z9 7 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0377-0486 J9 J RAMAN SPECTROSC JI J. Raman Spectrosc. PD JUN PY 2003 VL 34 IS 6 BP 404 EP 412 DI 10.1002/jrs.1011 PG 9 WC Spectroscopy SC Spectroscopy GA 701XG UT WOS:000184193800002 ER PT J AU DeVault, TL Stephens, WL Reinhart, BD Rhodes, OE Brisbin, IL AF DeVault, TL Stephens, WL Reinhart, BD Rhodes, OE Brisbin, IL TI Aerial telemetry accuracy in a forested landscape SO JOURNAL OF RAPTOR RESEARCH LA English DT Article DE aerial telemetry; geographic information system; radiotelemetry; telemetry error ID HOME RANGES; TRIANGULATION; LOCATIONS; ERROR; BIAS C1 Purdue Univ, Dept Forestry & Nat Resources, W Lafayette, IN 47907 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Purdue Univ, Dept Forestry & Nat Resources, W Lafayette, IN 47907 USA. RP DeVault, TL (reprint author), Purdue Univ, Dept Forestry & Nat Resources, W Lafayette, IN 47907 USA. NR 19 TC 5 Z9 6 U1 0 U2 0 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 14377 117TH STREET SOUTH, HASTINGS, MN 55033 USA SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD JUN PY 2003 VL 37 IS 2 BP 147 EP 151 PG 5 WC Ornithology SC Zoology GA 702PQ UT WOS:000184232600006 ER PT J AU Gourdon, O Miller, GJ AF Gourdon, O Miller, GJ TI Reinvestigation of the GaMn structure and theoretical studies of its electronic and magnetic properties SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE intermetallic compounds; gallium; manganese; ab initio band structure calculations; spin polarization; magnetism ID MNGA; ALLOYS; DIFFRACTION; CRYSTALS; SYSTEMS; AL3MN AB The crystal structure of the binary gallide compound GaMn is reinvestigated using X-ray diffraction. The structure is quite different front that proposed previously. Although GaMn is reported to crystallize with the Al8Cr5 structure type, space group R3m, we found that the centrosymmetric space group R (3) over barm, with a = 12.605(2) Angstrom and c = 8.0424(11) Angstrom, was more accurate. Moreover, the atomic positions and the atomic displacement parameters, which are missing in the previous study, are now refined. Thereafter, band structure calculations have been performed using the TB-LMTO-ASA method to understand the electronic and magnetic properties of this compound. Analyses from the band structure, the density of states and the magnetic moments obtained using spin-polarized calculations show the stability of two different magnetic models relative to the nonmagnetic one. (C) 2002 Elsevier Science (USA). All rights reserved. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. RP Miller, GJ (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 32 TC 21 Z9 21 U1 2 U2 15 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUN PY 2003 VL 173 IS 1 BP 137 EP 147 AR PII S0022-4596(02)00031-2 DI 10.1016/S0022-4596(02)00031-2 PG 11 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 689JX UT WOS:000183489700020 ER PT J AU Nakagawa, S Nihei, KT Myer, LR Majer, EL AF Nakagawa, S Nihei, KT Myer, LR Majer, EL TI Three-dimensional elastic wave scattering by a layer containing vertical periodic fractures SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID FINITE-ELEMENT METHOD; PLANE ACOUSTIC-WAVE; RESERVOIRS; CRACK AB Elastic wave scattering off a layer containing a single set of vertical periodic fractures is examined using a numerical technique based on the work of Hennion et al. [J. Acoust. Soc. Am. 87, 1861 1970 (1990)]. This technique combines the finite element method and plane wave method to simulate three-dimensional scattering off a two-dimensional fractured layer structure. Each fracture is modeled explicitly, so that the model can simulate both discrete arrivals of scattered waves from individual fractures and multiply scattered waves between the fractures. Using this technique, we examine changes in scattering characteristics of plane elastic waves as a function of wave frequency, angle of incidence, and fracture properties such as fracture stiffness, height, and regular and irregular spacing. (C) 2003 Acoustical Society of America. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Nakagawa, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Nakagawa, Seiji/F-9080-2015; Nihei, Kurt/K-1239-2016 OI Nakagawa, Seiji/0000-0002-9347-0903; NR 19 TC 8 Z9 8 U1 0 U2 4 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 2003 VL 113 IS 6 BP 3012 EP 3023 DI 10.1121/1.1572139 PG 12 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 688RB UT WOS:000183448700009 PM 12822772 ER PT J AU Scalerandi, M Agostini, V Delsanto, PP Van Den Abeele, K Johnson, PA AF Scalerandi, M Agostini, V Delsanto, PP Van Den Abeele, K Johnson, PA TI Local interaction simulation approach to modelling nonclassical, nonlinear elastic behavior in solids SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID WAVE SPECTROSCOPY NEWS; BEREA SANDSTONE; SLOW DYNAMICS; PROPAGATION; ROCK; HYSTERESIS; RELAXATION; MEMORY; DAMAGE AB Recent studies show that a broad category of materials share "nonclassical" nonlinear elastic behavior much different from "classical" (Landau-type) nonlinearity. Manifestations of "nonclassical" nonlinearity include stress-strain hysteresis and discrete memory in quasistatic experiments, and specific dependencies of the harmonic amplitudes with respect to the drive amplitude in dynamic wave experiments, which are remarkably different from those predicted by the classical theory. These materials have in common soft "bond" elements, where the elastic nonlinearity originates, contained in hard matter (e.g., a rock sample). The bond system normally comprises a small fraction of the total material volume, and can be localized (e.g., a crack in a solid) or distributed, as in a rock. In this paper a model is presented in which the soft elements are treated as hysteretic or reversible elastic units connected in a one-dimensional lattice to elastic elements (grains), which make up the hard matrix. Calculations are performed in the framework of the local interaction simulation approach (LISA). Experimental observations are well predicted by the model, which is now ready both for basic investigations about the physical origins of nonlinear elasticity and for applications to material damage diagnostics. (C) 2003 Acoustical Society of America. C1 Politecn Torino, Dipartimento Fis, INFM, Turin, Italy. Katholieke Univ Leuven, Interdisciplinary Res Ctr, Fac Sci, B-8500 Kortrijk, Belgium. Los Alamos Natl Lab, Nonlinear Elast Grp, Los Alamos, NM 87545 USA. RP Scalerandi, M (reprint author), Politecn Torino, Dipartimento Fis, INFM, Corso Duca degli Abruzzi 24, Turin, Italy. EM scalerandi@polito.it RI Agostini, Valentina/A-9570-2009; OI Agostini, Valentina/0000-0001-5887-1499; SCALERANDI, MARCO/0000-0003-0809-9976 NR 30 TC 45 Z9 48 U1 0 U2 5 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 2003 VL 113 IS 6 BP 3049 EP 3059 DI 10.1121/1.1570440 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 688RB UT WOS:000183448700013 PM 12822776 ER PT J AU White, CM Strazisar, BR Granite, EJ Hoffman, JS Pennline, HW AF White, CM Strazisar, BR Granite, EJ Hoffman, JS Pennline, HW TI Separation and capture of CO2 from large stationary sources and sequestration in geological formations - Coalbeds and deep saline aquifers SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Review ID PRESSURE SWING ADSORPTION; FIRED POWER-PLANTS; ALBERTA SEDIMENTARY BASIN; CARBON-DIOXIDE SEPARATION; LITHIUM ZIRCONATE POWDER; GREENHOUSE-GAS EMISSIONS; RESEARCH-AND-DEVELOPMENT; FIXED-BED OPERATIONS; LOW-RANK COALS; FLUE-GAS AB The topic of global warming as a result of increased atmospheric CO2 concentration is arguably the most important environmental issue that the world faces today. It is a global problem that will need to be solved on a global level. The link between anthropogenic emissions of CO2 with increased atmospheric CO2 levels and, in turn, with increased global temperatures has been well established and accepted by the world. International organizations such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC) have been formed to address this issue. Three options are being explored to stabilize atmospheric levels of greenhouse gases (GHGs) and global temperatures without severely and negatively impacting standard of living: (1) increasing energy efficiency, (2) switching to less carbon-intensive sources of energy, and (3) carbon sequestration. To be successful, all three options must be used in concert. The third option is the subject of this review. Specifically, this review will cover the capture and geologic sequestration of CO2 generated from large point sources, namely fossil-fuel-fired power gasification plants. Sequestration of CO2 in geological formations is necessary to meet the President's Global Climate Change Initiative target of an 18% reduction in GHG intensity by 2012. Further, the best strategy to stabilize the atmospheric concentration of CO2 results from a multifaceted approach where sequestration of CO2 into geological formations is combined with increased efficiency in electric power generation and utilization, increased conservation, increased use of lower carbon-intensity fuels, and increased use of nuclear energy and renewables. This review covers the separation and capture of CO2 from both flue gas and fuel gas using wet scrubbing technologies, dry regenerable sorbents, membranes, cryogenics, pressure and temperature swing adsorption, and other advanced concepts. Existing commercial CO2 capture facilities at electric power-generating stations based on the use of monoethanolamine are described, as is the Rectisol process used by Dakota Gasification to separate and capture CO2 from, a coal gasifier. Two technologies for storage of the captured CO2 are reviewed-sequestration in deep unmineable coalbeds with concomitant recovery of CH4 and sequestration in deep saline aquifers. Key issues for both of these techniques include estimating the potential storage capacity, the storage integrity, and the physical and chemical processes that are initiated by injecting CO2 underground. Recent studies using computer modeling as well as laboratory and field experimentation are presented here. In addition, several projects have been initiated in which CO2 is injected into a deep coal seam or saline aquifer. The current status of several such projects is discussed. Included is a commercial-scale project in which a million tons of CO2 are injected annually into an aquifer under the North Sea in Norway. The review makes the case that this can all be accomplished safely with off-the-shelf technologies. However, substantial research and development must be performed to reduce the cost, decrease the risks, and increase the safety of sequestration technologies. This review also includes discussion of possible problems related to deep injection of CO2. There are safety concerns that need to be addressed because of the possibilities of leakage to the surface and induced seismic activity. These issues are presented along with a case study of a similar incident in the past. It is clear that monitoring and verification of storage will be a crucial part of all geological sequestration practices so that such Problems may be avoided. Available techniques include direct measurement of CO2 and CH4 surface soil fluxes, the use of chemical tracers, and underground 4-D seismic monitoring. Ten new hypotheses were formulated to describe what happens when CO2 is pumped into a coal seam. These hypotheses provide significant insight into the fundamental chemical, physical, and thermodynamic phenomena that occur during coal seam sequestration of CO2. C1 Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP White, CM (reprint author), Natl Energy Technol Lab, 626 Cochrans Mill Rd,POB 10940, Pittsburgh, PA 15236 USA. NR 447 TC 376 Z9 382 U1 37 U2 278 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD JUN PY 2003 VL 53 IS 6 BP 645 EP 715 PG 71 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 687FG UT WOS:000183365100003 PM 12828330 ER PT J AU Chou, YS Stevenson, JW Chick, LA AF Chou, YS Stevenson, JW Chick, LA TI Novel compressive mica seals with metallic interlayers for solid oxide fuel cell applications SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GLASS-CERAMICS; SOFC; PROGRESS AB A novel hybrid compressive mica seal was developed that showed an exceptionally low leak rate of similar to8.9 x 10(-4) sccm/cm (standard cubic centimeters per minute per unit leak length of seal) at 800degreesC and a compressive stress of 100 psi, about 740 times lower than that of the conventional compressive mica seals (6.6 x 10(-1) sccm/cm), at a pressure gradient of 2 psi. The hybrid compressive mica seals were composed of two compliant metallic layers and a mica layer. Three commercially available micas were tested in this study. All showed substantial improvements in reducing the leak rates by using the hybrid design. The best results were obtained using muscovite single-crystal mica and 125 mum silver layers. Using the paper form of muscovite and phlogopite mica, the leak rates were still far superior (similar to1 x 10(-1) sccm/cm) compared with mica without the compliant silver layer (about 6-9 sccm/cm). The microstructure of the mica was examined before and after the 800degreesC leak tests. These results are compared with results for hybrid seals using glass interlayers. In addition, an explanation for the substantial reduction of the leak rates is proposed, and the application of the hybrid compressive mica seals in planar SOFC stacks is briefly addressed. C1 Pacific NW Natl Lab, Mat Resource Dept, Richland, WA 99352 USA. RP Chou, YS (reprint author), Pacific NW Natl Lab, Mat Resource Dept, Richland, WA 99352 USA. NR 11 TC 40 Z9 41 U1 1 U2 9 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 2003 VL 86 IS 6 BP 1003 EP 1007 PG 5 WC Materials Science, Ceramics SC Materials Science GA 689NF UT WOS:000183499200019 ER PT J AU Tadesse, I Isoaho, SA Puhakka, JA Green, FB AF Tadesse, I Isoaho, SA Puhakka, JA Green, FB TI Transformation of sulphur in wastewater pond system (R) advanced integrated treating tannery effluent SO JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION LA English DT Article ID STABILIZATION PONDS; SULFATE; REMOVAL; PERFORMANCE; REDUCTION; BACTERIA AB An outdoor experiment was conducted to study the fate and transformation of sulphur in tannery wastewater being treated by a novel pond-based wastewater treatment technology known as the Advanced Integrated Wastewater Pond System(R) or AIWPS(R). The experiment used a research-scale AIWPS(R) consisting of a primary Advanced Facultative Pond (AFP) with submerged Fermentation Pit (FP), Secondary Facultative Pond (SFP) and Maturation Pond (MP) all arranged in series. Screening and settling were included as sequential pretreatments. The sulphate and sulphide concentrations of the raw tannery wastewater varied between 150 and 3,500 mg/l and 100 and 800 mg/l, respectively. In a three-phased experiment, the AIWPS(R) facility was subjected to increasing organic and sulphate loadings. With sulphate loading rates of 78-244 g/m(3)-d over the experiment phases, the AFP with the FP attained a total sulphur (SO(4)(=)-S + S(=)-S) removal of 67-79%. Dissimilar sulphate reduction in the submerged FP followed by photosynthetic sulphide oxidation into elemental sulphur in the solar illuminated upper water layers was the major sulphur removal mechanism in the AFP. The overall organics removal performance of the AFP was not adversely affected by increased organics and sulphate loading rates. With an increase of sulphate loading from 78 g/m(3)-d during phase 1 to 122 g/m'-d during phase 2 and a corresponding COD loading increase from 560 to 1480 g/m'-d, COD removal efficiency in the AFP dropped by only 4%. Some process instability with inhibition of methane fermentation in the AFP and domination of microalgae by photosynthetic sulphur bacteria in the SFP were observed during phase 3 when the AFP was subjected to extreme sulphate and COD loading rates of 244 and 1,860 g/m'-d, respectively. The extreme loading rates decreased the COD removal efficiency of the AFP by only 25%. Odour free operations and high organics and sulphur removal performances of the AFP were due to the proliferations of microbial morphotypes similar to genera: Thiocystis, Rhodobacter, Rhodopselidomonas and Rhodospirillion. A sulphur scum with purity of up to 35% sulphur was recovered from the AFP water surface. Gentle mixing in the upper water layers of the SFP remedied the unwanted domination of algae by pink sulphur bacteria. C1 Tampere Univ Technol, Inst Environm Engn & Biotechnol, FIN-33101 Tampere, Finland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Tadesse, I (reprint author), Tampere Univ Technol, Inst Environm Engn & Biotechnol, POB 541, FIN-33101 Tampere, Finland. EM issayas.tadesse@tut.fi RI Puhakka, Jaakko/G-4220-2014 NR 40 TC 3 Z9 4 U1 1 U2 4 PU AMER LEATHER CHEMISTS ASSOC PI LUBBOCK PA TEXAS TECH UNIV, BOX 45300, LUBBOCK, TX 79409-5300 USA SN 0002-9726 J9 J AM LEATHER CHEM AS JI J. Am. Leather Chem. Assoc. PD JUN PY 2003 VL 98 IS 6 BP 203 EP 215 PG 13 WC Chemistry, Applied; Materials Science, Textiles SC Chemistry; Materials Science GA 688GK UT WOS:000183425700001 ER PT J AU Li, FM Byers, MA Houk, RS AF Li, FM Byers, MA Houk, RS TI Tandem mass spectrometry of metal nitrate negative ions produced by electrospray ionization SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID COLLISION-INDUCED DISSOCIATION; ORGANOMETALLIC CHEMISTRY; ELEMENTAL SPECIATION; AQUEOUS-SOLUTIONS; COMPLEXES; IDENTIFICATION; SPECTROSCOPY; PROTEINS; ENERGY; TOOL AB M(NO3)(x)(-) ions are generated by electrospray ionization (ESI) of metal solutions in nitric acid in negative ion mode. Collision-induced reactions of these ions are monitored in a tandem mass spectrometer (MS) of quadrupole-octopole-quadrupole (QoQ) geometry. For Group land 2 elements, the M(NO3)(x)(-) ions dissociate into NO3 and neutral metal nitrate molecules. These elements also form some M-x(NO3)(x+1)(-) clusters, especially Li+. Metal nitrate ions from transition elements and Group 13 elements fragment into oxo products and also undergo internal electron transfer to leave the M atom in a lower oxidation state. To calibrate the collision energy, the dissociation energy of O-NO2- is found to be 5.55 eV, about 0.76 eV lower than a value derived from thermochemistry. The product ions from Fe(NO3)(4)(-) ions have low formation thresholds of only 0.5 to 2 eV. (J Am Soc Mass Spectrom 2003,14, 671-679) (C) 2003 American Society for Mass Spectrometry. C1 Iowa State Univ, US DOE, Dept Chem, Ames Lab, Ames, IA 50011 USA. RP Houk, RS (reprint author), Iowa State Univ, US DOE, Dept Chem, Ames Lab, Ames, IA 50011 USA. NR 36 TC 19 Z9 19 U1 0 U2 13 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JUN PY 2003 VL 14 IS 6 BP 671 EP 679 DI 10.1016/S1044-0305(03)00210-1 PG 9 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 684BJ UT WOS:000183185300013 PM 12781468 ER PT J AU Song, SJ Wachsman, ED Dorris, SE Balachandranb, U AF Song, SJ Wachsman, ED Dorris, SE Balachandranb, U TI Electrical properties of p-type electronic defects in the Protonic conductor SrCe0.95Eu0.05O3-delta SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID YB-DOPED SRCEO3; HIGH-TEMPERATURE; SOLID ELECTROLYTES; OXIDES; SRCE0.95YB0.05O3; ATMOSPHERES; BEHAVIOR; HYDROGEN; MOBILITY; CELLS AB The electrical properties of SrCe0.95Eu0.05O3-delta were studied as a function of both oxygen partial pressure and water vapor partial pressure in the temperature range of 500-800degreesC, and the partial conductivities of protons, holes, and oxygen vacancies were calculated from the proposed defect model. P-type conduction was dominant in an oxidative atmosphere. It was shown that, in a wet atmosphere, SrCe0.95Eu0.05O3-delta is a mixed conductor of protons, holes, and oxygen ions. A conduction transition from protons to holes and/or oxygen ions was found as temperature increased. The calculated activation energy of oxygen ion transport was 0.67 eV; standard solution enthalpy of water dissolution was -164 kJ/mole, which is larger than that of SrCe0.95Yb0.05O3-delta. The effect of dopants on the conduction mechanism is explained by a hopping mechanism. (C) 2003 The Electrochemical Society. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Wachsman, ED (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 25 TC 54 Z9 54 U1 0 U2 6 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 2003 VL 150 IS 6 BP A790 EP A795 DI 10.1149/1.1574031 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 679RK UT WOS:000182935600022 ER PT J AU Kelly, JJ Yang, N Headley, T Hachman, J AF Kelly, JJ Yang, N Headley, T Hachman, J TI Experimental study of the microstructure and stress of electroplated gold for microsystem applications SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID DEPOSITION AB Gold, used as an X-ray absorber for lithography and as a structural or conducting material in microsystems, was deposited from a commercially available sulfite electrolyte. The effects of current type and an arsenic additive on the gold microstructure and residual stress were studied. Using a simple bent strip method, good agreement with literature stress values determined via other methods was obtained. Without arsenic, residual stresses are tensile (similar to 50 MPa) regardless of current type. With 25 ppm arsenic, the stress is compressive for direct current (ca. -30 MPa), with pulsed current reducing the stress to <-5 MPa compressive; this has been noted previously with thallium as an additive. The addition of arsenic does not appreciably change the film grain size but does lower the twin density and modify texture. Pores were observed in all the gold films, but were larger and less concentrated for films produced with arsenic; for the case of direct current with arsenic, the pores were concentrated at the grain boundaries. Consistencies in the microstructural observations and thin film stress theories are discussed. (C) 2003 The Electrochemical Society. C1 Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94551 USA. Sandia Natl Labs, Mat & Proc Sci Ctr, Albuquerque, NM 87185 USA. RP Kelly, JJ (reprint author), Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94551 USA. NR 23 TC 13 Z9 16 U1 3 U2 13 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 2003 VL 150 IS 6 BP C445 EP C450 DI 10.1149/1.1573197 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 679RK UT WOS:000182935600046 ER PT J AU Nilson, RH Griffiths, SK AF Nilson, RH Griffiths, SK TI Natural convection in trenches of high aspect ratio SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SHAPE EVOLUTION; HEAT-TRANSFER; ELECTRODEPOSITED BUMPS; THERMAL-CONVECTION; CAVITY; FLOW; SIMULATION; TRANSPORT; COPPER AB Filling deep trench-like features by electrodeposition is often limited by ion transport from the electrolyte bath to the plating surface at the feature bottom. This transport may be substantially enhanced by buoyancy-driven convection induced by metal-ion depletion adjacent to the plating surface. Numerical solutions of the Navier-Stokes and species transport equations are used to determine the magnitude of transport enhancement, expressed as a Sherwood number, for Rayleigh numbers ranging from 103 to 108 and for feature aspect ratios of depth to width ranging from 1 to 16 both for open trenches and for fully enclosed rectangular domains. To facilitate extrapolation of these numerical results, an exact analytical solution is derived for aspect ratios much greater than unity. This is used in conjunction with the known asymptotic behavior for large Rayleigh numbers to construct a composite formula relating the Sherwood number to the Rayleigh number and aspect ratio. The results indicate that buoyancy-driven convection may provide significant transport enhancement during electrodeposition into features having depths greater than about 100 mum and that enhancement exceeding a factor of ten may occur in LIGA features having depths of 1 mm or more. It is also shown that a moderate inclination of the substrate helps to suppress the formation of multiple vertically stacked convective cells that would otherwise reduce the overall transport. (C) 2003 The Electrochemical Society. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Nilson, RH (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 34 TC 19 Z9 19 U1 0 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 2003 VL 150 IS 6 BP C401 EP C412 DI 10.1149/1.1569480 PG 12 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 679RK UT WOS:000182935600040 ER PT J AU Mansour, AN Smith, PH Baker, WM Balasubramanian, M McBreen, J AF Mansour, AN Smith, PH Baker, WM Balasubramanian, M McBreen, J TI Comparative in situ X-ray absorption spectroscopy study of nanophase V2O5 aerogel and ambigel cathodes (vol 150, pg A403, 2003) SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Correction C1 Naval Surface Warfare Ctr, Carderock Div, Bethesda, MD 20817 USA. Brookhaven Natl Lab, Div Mat, Upton, NY 11973 USA. RP Mansour, AN (reprint author), Naval Surface Warfare Ctr, Carderock Div, Code 644, Bethesda, MD 20817 USA. NR 1 TC 1 Z9 1 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 2003 VL 150 IS 6 BP L13 EP L13 DI 10.1149/1.1574327 PG 1 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 679RK UT WOS:000182935600066 ER PT J AU Gerberich, WW Mook, WM Perrey, CR Carter, CB Baskes, MI Mukherjee, R Gidwani, A Heberlein, J McMurry, PH Girshick, SL AF Gerberich, WW Mook, WM Perrey, CR Carter, CB Baskes, MI Mukherjee, R Gidwani, A Heberlein, J McMurry, PH Girshick, SL TI Superhard silicon nanospheres SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article DE dislocations; indentation and hardness; strengthening and mechanisms ID MOLECULAR-DYNAMICS; LENGTH-SCALE; NANOINDENTATION; INDENTATION; DEFORMATION; DIMENSIONS; DEPOSITION; PLASTICITY; SIMULATION; BEHAVIOR AB Successful deposition and mechanical probing of nearly spherical, defect-free silicon nanospheres has been accomplished. The results show silicon at this length scale to be up to four times harder;than bulk silicon. Detailed measurements of plasticity evolution and the corresponding hardening response in normally brittle silicon is possible in these small volumes. Based upon a proposed length scale related to the size of nanospheres in the 20-50 nm radii range, a prediction of observed hardnesses in the range of 20-50 GPa is made. The ramifications of this to computational materials science studies on identical volumes are discussed. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Univ Minnesota, Minneapolis, MN 55455 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Gerberich, WW (reprint author), Univ Minnesota, 151 Amundson Hall,421 Washington, Minneapolis, MN 55455 USA. RI Carter, C. Barry/E-6478-2010; McMurry, Peter/A-8245-2008 OI Carter, C. Barry/0000-0003-4251-9102; McMurry, Peter/0000-0003-1609-5131 NR 33 TC 154 Z9 154 U1 4 U2 44 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD JUN PY 2003 VL 51 IS 6 BP 979 EP 992 DI 10.1016/S0022-5096(03)00018-8 PG 14 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 668PP UT WOS:000182302600001 ER PT J AU Wang, YJ Kim, YJ Christianson, RJ LaMarra, SC Chou, FC Masuda, T Tsukada, I Uchinokura, K Birgeneau, RJ AF Wang, YJ Kim, YJ Christianson, RJ LaMarra, SC Chou, FC Masuda, T Tsukada, I Uchinokura, K Birgeneau, RJ TI X-ray scattering and magnetic susceptibility study of doped CuGeO3 SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE spin-Peierls; CuGeO3; doping; x-ray scattering; magnetic susceptibility ID SPIN-PEIERLS SYSTEMS; UNIFORM-ANTIFERROMAGNETIC PHASES; NEUTRON-SCATTERING; COMPOUND CUGEO3; SOLITON LATTICE; SINGLE-CRYSTALS; CUPRATE CUGEO3; RANDOM-FIELDS; DIAGRAM; TRANSITION AB We report comprehensive synchrotron x-ray scattering and magnetic susceptibility studies of the doped spin-Peierls materials Cu1-xZnxGeO3 and CuGe1-ySiyO3. Temperature versus dopant concentration phase diagrams are mapped out for both Zn and Si dopants. The phase diagrams of both Cu1-xZnxGeO3 and CuGe1-ySiyO3 closely resemble that of Cu1-xMgxGeO3, including the observation that the spin gap is established at a much higher temperature than the temperature at which the spin-Peierls dimerization attains long-range order. The spin-Peierls transitions in doped samples exhibit unusual phase transition behavior, characterized by highly rounded phase transitions, Lorentzian squared lineshapes, and very long relaxation times. Phenomenological explanations for these observations are given by considering the effects of competing random bond interactions as well as random fields generated by the dopants. We have also confirmed the reentrance of the spin-Peierls phase when the temperature is lowered through the antiferromagnetic ordering transition. The low temperature re-entrance of the spin-Peierls phase has been explained speculatively using a local phase separation scheme between the spin-Peierls phase and the Neel phase. C1 MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. RP Wang, YJ (reprint author), MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. RI Kim, Young-June /G-7196-2011; wang, yujie/C-2582-2015 OI Kim, Young-June /0000-0002-1172-8895; NR 47 TC 8 Z9 8 U1 1 U2 3 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JUN PY 2003 VL 72 IS 6 BP 1544 EP 1553 DI 10.1143/JPSJ.72.1544 PG 10 WC Physics, Multidisciplinary SC Physics GA 693LN UT WOS:000183719200038 ER PT J AU Chow, R Decker, TA Gansert, RV Gansert, D Lee, D AF Chow, R Decker, TA Gansert, RV Gansert, D Lee, D TI Properties of aluminum deposited by a HVOF process SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE aluminum; hardness; HVOF; porosity; roughness ID COATINGS; STEEL AB Pure aluminum coatings deposited by a high velocity oxyfuel (HVOF) process have been produced and studied. A simple design-of-experiment (DOE) was used to assess the effect of two deposition parameters, the spray distance and oxygen-to-fuel ratio, on relevant coating properties. Porosity, surface roughness, and micro-hardness of the coatings were measured as responses to changes in the DOE parameters. The results indicated that these three properties of the aluminum coatings were normally insensitive to spray distance. Oxygen-to-fuel ratio, by flow, did appear to affect the porosity level of the coatings. Some post-coat processing of the aluminum coatings and minimization of nozzle loading are discussed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Stellite Coatings, Goshen, IN USA. Hardface Alloys Inc, Sante Fe Springs, CA USA. RP Chow, R (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD JUN PY 2003 VL 12 IS 2 BP 208 EP 213 DI 10.1361/105996303770348311 PG 6 WC Materials Science, Coatings & Films SC Materials Science GA 692RC UT WOS:000183673200004 ER PT J AU Malkin, AJ McPherson, A Gershon, PD AF Malkin, AJ McPherson, A Gershon, PD TI Structure of intracellular mature vaccinia virus visualized by in situ atomic force microscopy SO JOURNAL OF VIROLOGY LA English DT Article ID DNA TOPOISOMERASE; CORE PROTEIN; MEMBRANE; RESOLUTION; VIRIONS AB Vaccinia virus, the basis of the smallpox vaccine, is one of the largest viruses to replicate in humans. We have used in situ atomic force microscopy (AFM) to directly visualize fully hydrated, intact intracellular mature vaccinia virus (IMV) virions and chemical and enzymatic treatment products thereof. The latter included virion cores, core-enveloping coats, and core substructures. The isolated coats appeared to be composed of a highly cross-linked protein array. AFM imaging of core substructures indicated association of the linear viral DNA genome with a segmented protein sheath forming an extended similar to16-nm-diameter filament with helical surface topography; enclosure of this filament within a 30- to 40-nm-diameter tubule which also shows helical topography; and enclosure of the folded, condensed 30- to 40-nm-diameter tubule within the core by a wall covered with peg-like projections. Proteins observed attached to the 30- to 40-nm-diameter tubules may mediate folding and/or compaction of the tubules and/or represent vestiges of the core wall and/or pegs. An accessory "satellite domain" was observed protruding from the intact core. This corresponded in size to isolated 70- to 100-nm-diameter particles that were imaged independently and might represent detached accessory domains. AFM imaging of intact virions indicated that IMV underwent a reversible shrinkage upon dehydration (as much as 2.2- to 2.5-fold in the height dimension), accompanied by topological and topographical changes, including protrusion of the satellite domain. As shown here, the chemical and enzymatic dissection of large, asymmetrical virus particles in combination with in situ AFM provides an informative complement to other structure determination techniques. C1 Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Biosecur & Nanosci Lab, Livermore, CA 94551 USA. Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA. Texas A&M Univ Syst Hlth Sci Ctr, Inst Biosci & Technol, Dept Med Biochem & Genet, Houston, TX 77030 USA. RP Malkin, AJ (reprint author), Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Biosecur & Nanosci Lab, L-233,POB 808, Livermore, CA 94551 USA. FU NIGMS NIH HHS [R01 GM501953] NR 41 TC 58 Z9 62 U1 0 U2 8 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0022-538X J9 J VIROL JI J. Virol. PD JUN PY 2003 VL 77 IS 11 BP 6332 EP 6340 DI 10.1128/JVI.77.11.6332-6340.2003 PG 9 WC Virology SC Virology GA 679NL UT WOS:000182928800025 PM 12743290 ER PT J AU Burger, C Ran, S Fang, DF Cookson, D Yabuki, K Teramoto, Y Cunniff, PM Viccaro, PJ Hsiao, BS Chu, B AF Burger, C Ran, S Fang, DF Cookson, D Yabuki, K Teramoto, Y Cunniff, PM Viccaro, PJ Hsiao, BS Chu, B TI Time-resolved structural studies in fiber processing SO MACROMOLECULAR SYMPOSIA LA English DT Article; Proceedings Paper CT 39th International Symposium on Macromolecules CY JUL 07-12, 2002 CL BEIJING, PEOPLES R CHINA SP Chinese Chem Soc DE high performance polymers; fibers; spinning; WAXS; SAXS AB Time-resolved and off-line synchrotron wide-angle and small-angle x-ray scattering (WAXS and SAXS) was used to study the structure formation in poly-p-phenylenebenzobisoxazole (PBO) fibers during various stages of spinning, coagulation, and heating processes. WAXS data could be explained in terms of liquid-crystalline structures of varying degrees of order. A structure model is proposed that is in accordance with the observed SAXS four-point pattern. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia. Argonne Natl Lab, Adv Photon Source, ChemMat CARS, Argonne, IL USA. Toyobo Co Ltd, Res Ctr, Otsu, Shiga, Japan. USA, Soldier & Biol Chem Command, Natick, MA 01760 USA. RP Chu, B (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. NR 6 TC 4 Z9 4 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD JUN PY 2003 VL 195 BP 297 EP 302 DI 10.1002/masy.200390138 PG 6 WC Polymer Science SC Polymer Science GA 706UX UT WOS:000184474400039 ER PT J AU Chieh, TC Chu, J Liu, CT Wu, JK AF Chieh, TC Chu, J Liu, CT Wu, JK TI Corrosion of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glasses in aqueous solutions SO MATERIALS LETTERS LA English DT Article DE Zr-based amorphous alloy; corrosion resistance; pitting corrosion; aqueous solutions ID ZR65AL7.5NI10CU17.5 AMORPHOUS ALLOY; PHOSPHATE-BUFFERED SOLUTION; POLARIZATION BEHAVIOR; SUPERCOOLED LIQUID; SUPERPLASTICITY; STABILIZATION; RESISTANCE; OXYGEN AB Zr-based amorphous alloy exhibits excellent corrosion resistance in 3.5% NaCl solution and good corrosion resistance in HNO3 and H2SO4 solutions. The corrosion resistance of Zr-based alloy is extremely poor in HCl solution. Zr-based specimens after various tests show excellent pitting corrosion resistance. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Taiwan Ocean Univ, Inst Mat Engn, Chilung 20224, Taiwan. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Wu, JK (reprint author), Natl Taiwan Ocean Univ, Inst Mat Engn, Chilung 20224, Taiwan. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 16 TC 20 Z9 24 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JUN PY 2003 VL 57 IS 20 BP 3022 EP 3025 DI 10.1016/S0167-577X(02)01424-6 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 689EZ UT WOS:000183479800007 ER PT J AU Hassold, GN Holm, EA Miodownik, MA AF Hassold, GN Holm, EA Miodownik, MA TI Accumulation of coincidence site lattice boundaries during grain growth SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID MISORIENTATION DISTRIBUTION; ENERGY; ORIENTATION; SIMULATION; EVOLUTION AB Monte Carlo simulations were used to investigate the effect of grain growth on the coincidence site lattice (CSL) boundary content of randomly textured polycrystals. Each grain was assigned an orientation, and grain boundary properties were dependent on both the boundary misorientation and the CSL character. While low misorientation angle boundaries (LABs) increase during growth, the fraction of CSL boundaries does not change with time. Decreasing CSL boundary energy and mobility did not alter these results. In contrast with LABs, which are characterised by a scalar misorientation angle, a particular combination of three independent rotation variables is required to create a low energy CSL boundary; thus, these boundaries are unlikely to form or to persist in a random polycrystal. While texture influences boundary formation, a texture that can enhance CSL boundaries is not apparent. Boundary plane effects should not increase CSL fraction during grain growth. C1 Kettering Univ, Dept Sci & Math, Flint, MI 48504 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Kings Coll London, Dept Engn Mech, London WC2R 2LS, England. RP Hassold, GN (reprint author), Kettering Univ, Dept Sci & Math, Flint, MI 48504 USA. EM mark.miodownik@kcl.ac.uk RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 29 TC 16 Z9 17 U1 1 U2 5 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 0267-0836 J9 MATER SCI TECH-LOND JI Mater. Sci. Technol. PD JUN PY 2003 VL 19 IS 6 BP 683 EP 687 DI 10.1179/026708303225002893 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 698DY UT WOS:000183983400002 ER PT J AU Agarwal, S AF Agarwal, S TI A broad perspective on federal technology transfer in the USA SO MATERIALS TECHNOLOGY LA English DT Editorial Material C1 INEEL, Idaho Falls, ID 83415 USA. RP Agarwal, S (reprint author), INEEL, 2525 N Fremont Ave, Idaho Falls, ID 83415 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU MATRICE TECHNOLOGY LIMITED PI POULTON PA PO BOX 41, POULTON FY6 8GD, ENGLAND SN 1066-7857 J9 MATER TECHNOL JI Mater. Technol. PD JUN PY 2003 VL 18 IS 2 BP 66 EP 69 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 688HE UT WOS:000183427500002 ER PT J AU Scalerandi, M Peggion, F Sansone, BC Benati, C AF Scalerandi, M Peggion, F Sansone, BC Benati, C TI Avascular and vascular phases in tumor cords growth SO MATHEMATICAL AND COMPUTER MODELLING LA English DT Article DE tumor cords; simulation; angiogenesis; phase transition; energy conservation ID MODEL; SIMULATION; CANCER; RESISTANCE; PATTERNS; KINETICS; THERAPY AB A general feature of cancer growth is the cellular competition for available nutrients. This is also the case for tumor cords, neoplasms forming cylindrical structures around blood vessels. Experimental data show that, in their avascular phase, cords grow up to a limit radius, rapidly reaching a quasi-steady state. At this stage, a transition towards a vascular phase (i.e., the formation of a new vascular system feeding the tumor) occurs and the growth becomes uncontrolled. Here we use a set of rules to formulate a model that describes how the dynamics of cord growth is controlled by this transition. The model takes into account mechanical effects resulting from the interaction between the multiplying cancer cells and the surrounding tissue. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Politecn Torino, Dipartimento Fis, INFM, I-10129 Turin, Italy. Los Alamos Natl Lab, Los Alamos, NM USA. RP Scalerandi, M (reprint author), Politecn Torino, Dipartimento Fis, INFM, Corso Duca Abruzzi 24, I-10129 Turin, Italy. EM scalerandi@polito.it OI SCALERANDI, MARCO/0000-0003-0809-9976 NR 30 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-7177 J9 MATH COMPUT MODEL JI Math. Comput. Model. PD JUN PY 2003 VL 37 IS 11 BP 1191 EP 1200 AR PII S0895-7177(03)00130-4 DI 10.1016/S0895-7177(03)00130-4 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 694AC UT WOS:000183749700008 ER PT J AU Rivardl, MJ Kirk, BL AF Rivardl, MJ Kirk, BL TI Testes dose following implantation using I-125 and Pd-103 SO MEDICAL PHYSICS LA English DT Meeting Abstract CT 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine CY AUG 10-14, 2003 CL SAN DIEGO, CALIFORNIA SP Amer Assoc Physicists Med C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUN PY 2003 VL 30 IS 6 BP 1430 EP 1430 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 692JT UT WOS:000183658500479 ER PT J AU Kieper, D Green, T Keppel, C Kross, B Weisenberger, A Welch, B Wojcik, R Wymer, D AF Kieper, D Green, T Keppel, C Kross, B Weisenberger, A Welch, B Wojcik, R Wymer, D TI Breast lesion dynamic radiotracer uptake analysis employing a combined digital x-ray/gamma system SO MEDICAL PHYSICS LA English DT Meeting Abstract CT 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine CY AUG 10-14, 2003 CL SAN DIEGO, CALIFORNIA SP Amer Assoc Physicists Med C1 Hampton Univ, Newport News, VA USA. Jefferson Lab, Newport News, VA USA. Old Dominion Univ, Norfolk, VA USA. Univ Florida, Gainesville, FL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUN PY 2003 VL 30 IS 6 BP 1438 EP 1438 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 692JT UT WOS:000183658500518 ER PT J AU Kieper, D Green, T Keppel, C Kross, B Welch, B Weisenberger, A Wojcik, R Wymer, D AF Kieper, D Green, T Keppel, C Kross, B Welch, B Weisenberger, A Wojcik, R Wymer, D TI Spatial correlation of mammographic radiodensities and scintimammographic radiotracer distribution using a dedicated dual modality breast imaging system SO MEDICAL PHYSICS LA English DT Meeting Abstract CT 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine CY AUG 10-14, 2003 CL SAN DIEGO, CALIFORNIA SP Amer Assoc Physicists Med C1 Hampton Univ, Newport News, VA USA. Jefferson Lab, Newport News, VA USA. Old Dominion Univ, Norfolk, VA USA. Univ Florida, Gainesville, FL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUN PY 2003 VL 30 IS 6 BP 1438 EP 1438 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 692JT UT WOS:000183658500516 ER PT J AU Lehmann, J Pawlicki, T AF Lehmann, J Pawlicki, T TI IMRT: Better plans with tuning structures SO MEDICAL PHYSICS LA English DT Meeting Abstract CT 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine CY AUG 10-14, 2003 CL SAN DIEGO, CALIFORNIA SP Amer Assoc Physicists Med C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Stanford Univ, Med Ctr, Sch Med, Stanford, CA 94305 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUN PY 2003 VL 30 IS 6 BP 1485 EP 1486 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 692JT UT WOS:000183658500737 ER PT J AU Lamberton, JS Christian, AT AF Lamberton, JS Christian, AT TI Varying the nucleic acid composition of siRNA molecules dramatically varies the duration and degree of gene silencing SO MOLECULAR BIOTECHNOLOGY LA English DT Article DE RNA interference; siRNA; mutagenesis; DNA : RNA hybrid; eukaryote; gene silencing; posttranscriptional ID RNA INTERFERENCE; MESSENGER-RNA; ANTISENSE OLIGONUCLEOTIDES; CAENORHABDITIS-ELEGANS; C-ELEGANS; CELLS; EXPRESSION; DROSOPHILA; TARGET; AGENTS AB The utility of short interfering RNA (siRNA) as a means of gene silencing depends on several factors. These include the degree to which a gene can be silenced, the length of time for which the gene remains silenced, the degree of recovery of gene function, and the effects of the silencing process on general cell functions. We hypothesized that changing the nucleic acid composition of the siRNA constructs used for silencing would affect these parameters. With siRNA gene silencing of the glucose-6-phosphate dehydrogenase gene as a baseline, we found that siDNA molecules have an effect that is similar in duration but lesser in degree, Whereas hybrid DNA:RNA molecules have an effect that is enormously greater in both duration and degree. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. FU NCI NIH HHS [CA55861] NR 25 TC 12 Z9 14 U1 0 U2 2 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 1073-6085 J9 MOL BIOTECHNOL JI Mol. Biotechnol. PD JUN PY 2003 VL 24 IS 2 BP 111 EP 119 DI 10.1385/MB:24:2:111 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 683WG UT WOS:000183173600003 PM 12746552 ER PT J AU Hauswaldt, JS Glenn, TC AF Hauswaldt, JS Glenn, TC TI Microsatellite DNA loci from the Diamondback terrapin (Malaclemys terrapin) SO MOLECULAR ECOLOGY NOTES LA English DT Article DE dinucleotide repeats; Malaclemys terrapin; microsatellites; primer; SSR; tetranucleotide repeats AB We describe polymerase chain recation (PCR) primers and conditions to amplify one dinucleotide and five tetranucleotide microsatellite DNA loci isolated from the Diamondback terrapin (Malaclemys terrapin). The PCR primers were tested on 21 terrapins from Cape Romain, SC, USA. The microsatellite primers developed yielded a high number of alleles (8-14) and high observed heterozygosities (0.57-1.0). C1 Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Hauswaldt, JS (reprint author), Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. RI Glenn, Travis/A-2390-2008 NR 10 TC 87 Z9 91 U1 1 U2 9 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1471-8278 J9 MOL ECOL NOTES JI Mol. Ecol. Notes PD JUN PY 2003 VL 3 IS 2 BP 174 EP 176 DI 10.1046/j.1471-8286.2003.00388.x PG 3 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 688RX UT WOS:000183450700002 ER PT J AU Pamies, JC McCabe, C Cummings, PT Vega, LF AF Pamies, JC McCabe, C Cummings, PT Vega, LF TI Coexistence densities of methane and propane by canonical molecular dynamics and Gibbs ensemble Monte Carlo simulations SO MOLECULAR SIMULATION LA English DT Article ID LIQUID-VAPOR INTERFACE; PHASE-EQUILIBRIA; N-ALKANES; ALGORITHM; FLUIDS; MODEL AB We present preliminary canonical molecular dynamics (MD) and Gibbs ensemble Monte Carlo (GEMC) results for the vapour-liquid orthobaric densities of methane and propane. Computational advantages and drawbacks of both simulation methods are discussed and future work is outlined on the application of these techniques to the calculation of transport and interfacial properties. n-Alkanes are described through the TraPPE-UA force field. We study the effect of the truncation of interactions in the Lennard-Jones potential on the accuracy of the orthobaric liquid densities for these inhomogeneous systems along the phase diagram. We observed that a cutoff of at least 5.5 times the Lennard-Jones diameter is needed to obtain accurate results for saturated liquid densities. C1 Univ Rovira & Virgili, Dept Engn Quim, ETSEQ, Tarragona 43007, Spain. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Vega, LF (reprint author), Univ Rovira & Virgili, Dept Engn Quim, ETSEQ, Avinguda Paisos Catalans 26, Tarragona 43007, Spain. RI McCabe, Clare/I-8017-2012; Cummings, Peter/B-8762-2013; OI McCabe, Clare/0000-0002-8552-9135; Cummings, Peter/0000-0002-9766-2216; Pamies, Pep/0000-0003-2242-3752; Vega, Lourdes/0000-0002-7609-4184 NR 19 TC 15 Z9 15 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0892-7022 J9 MOL SIMULAT JI Mol. Simul. PD JUN PY 2003 VL 29 IS 6-7 BP 463 EP 470 DI 10.1080/0892702031000117270 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 696MU UT WOS:000183891300015 ER PT J AU Dattelbaum, AM Amweg, ML Ecke, LE Yee, CK Shreve, AP Parikh, AN AF Dattelbaum, AM Amweg, ML Ecke, LE Yee, CK Shreve, AP Parikh, AN TI Photochemical pattern transfer and enhancement of thin film silica mesophases SO NANO LETTERS LA English DT Article ID INORGANIC COMPOSITE FILMS; VACUUM-ULTRAVIOLET LIGHT; MESOPOROUS SILICA; PHOTOCALCINATION; GROWTH AB Here we present a spatially directed calcination approach based on masked UV exposure to pattern mesoporous regions within a mesostructured matrix in a rapid, single-step, and inexpensive manner. Subsequent chemical treatment of the film can selectively remove the mesostructured regions, leading to patterned mesoporous structures. Such tunability in the processing under near room-temperature conditions allows for spatial control and patterning of function related to optical properties, topology, porosity, hydrophobicity, and structural morphology of the mesoscopic thin film material on a wide range of substrates. C1 Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Parikh, AN (reprint author), Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RI PARIKH, ATUL/D-2243-2014 OI PARIKH, ATUL/0000-0002-5927-4968 NR 24 TC 37 Z9 37 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUN PY 2003 VL 3 IS 6 BP 719 EP 722 DI 10.1021/nl0341279 PG 4 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 689YX UT WOS:000183521500006 ER PT J AU Ahrenkiel, SP Micic, OI Miedaner, A Curtis, CJ Nedeljkovic, JM Nozik, AJ AF Ahrenkiel, SP Micic, OI Miedaner, A Curtis, CJ Nedeljkovic, JM Nozik, AJ TI Synthesis and characterization of colloidal InP quantum rods SO NANO LETTERS LA English DT Article ID LIQUID-SOLID GROWTH; SEMICONDUCTOR NANOWIRES; SELECTIVE SYNTHESIS; NANOPARTICLES; NANOCRYSTALS; ZINCBLENDE; DIAMETER; ARRAYS; SHAPE; DOTS AB InP nanorods and nanowires in the diameter range of 30-300 Angstrom and 100-1000 Angstrom in length were synthesized. For the preparation of nanorods, we used an organometallic precursor that decomposes thermally into InP and In metal particles. The [after serves as a nucleation catalyst for the growth of the semiconductor. Quantum rods of zinc blende structure with a high degree of crystallinity are grown along the (111) crystallographic planes. The absorption spectrum of InP nanorods with diameter of about 30 Angstrom and 100-300 Angstrom in length is in the visible spectral regime, suggesting a substantial blue shift with respect to the bulk (band gap 1.35 eV) that is due to size confinement. Moreover, the Stokes shift of the emission band in the quantum rods is substantially larger than the shift in the corresponding quantum dots. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ahrenkiel, SP (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM phil_ahrenkiel@nrel.gov RI Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 NR 25 TC 71 Z9 74 U1 2 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUN PY 2003 VL 3 IS 6 BP 833 EP 837 DI 10.1021/nl034152e 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 689YX UT WOS:000183521500029 ER PT J AU Stach, EA Pauzauskie, PJ Kuykendall, T Goldberger, J He, RR Yang, PD AF Stach, EA Pauzauskie, PJ Kuykendall, T Goldberger, J He, RR Yang, PD TI Watching GaN nanowires grow SO NANO LETTERS LA English DT Article ID GALLIUM NITRIDE; THIN-FILMS; DECOMPOSITION AB We report real-time high temperature transmission electron microscopy observations of the growth of GaN nanowires via a self-catalytic vapor-liquid-solid (VLS) mechanism. High temperature thermal decomposition of GaN in a vacuum yields nanoscale Ga liquid droplets and gallium/nitrogen vapor species for the subsequent GaN nanowire nucleation and growth. This is the first direct observation of self-catalytic growth of nanowires; via the VLS mechanism and suggests new strategies for synthesizing electronically pure single-crystalline semiconductor nanowires. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Stach, EA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Div Sci Mat, Berkeley, CA 94720 USA. RI Goldberger, Joshua/F-5484-2011; Stach, Eric/D-8545-2011; Pauzauskie, Peter/A-1316-2014; Goldberger, Joshua/N-8963-2016 OI Goldberger, Joshua/0000-0003-4284-604X; Stach, Eric/0000-0002-3366-2153; Goldberger, Joshua/0000-0003-4284-604X NR 14 TC 142 Z9 144 U1 2 U2 64 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUN PY 2003 VL 3 IS 6 BP 867 EP 869 DI 10.1021/nl034222h PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 689YX UT WOS:000183521500036 ER PT J AU Chen, XY Yang, L Cook, RE Skanthakumar, S Shi, D Liu, GK AF Chen, XY Yang, L Cook, RE Skanthakumar, S Shi, D Liu, GK TI Crystallization, phase transition and optical properties of the rare-earth-doped nanophosphors synthesized by chemical deposition SO NANOTECHNOLOGY LA English DT Article ID TRIVALENT EUROPIUM; EU2O3; NANOCRYSTALS; LUMINESCENCE; IONS; SPECTROSCOPY; NANOPARTICLES; FLUORESCENCE; RELAXATION; EU3+-Y2O3 AB The structural and electronic properties of Eu(3+)-doped Y(2)O(3) films coated on spherical alumina nanoparticles are studied using transmission electron microscope, x-ray diffraction, and laser spectroscopic techniques. It is observed that the coated films crystallize at temperatures higher than 600degreesC and may be completely converted into a cubic Y(2)O(3) nanocrystalline layer at 750degreesC. At 900degreesC, phase transition occurs between the outer coating layer and the inner core, and different types of crystalline nanophase can be obtained. In the materials that we prepared and studied, all possible crystallographic phases, including two of solid-state laser media, YAlO(3) (YAP), and Y(3)Al(5)O(12) (YAG), may be formed in the pseudo-binary Al(2)O(3)-Y(2)O(3) nanosystem by controlling thermal annealing procedures from 600 to 900degreesC, a temperature region far below the conventional solid-state reaction temperature. The spectroscopic properties of Eu(3+) in all the nanophases are characterized in comparison with those of their bulk counterparts. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Cincinnati, Dept Mat Sci & Engn, Cincinnati, OH 45221 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Liu, GK (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM gkliu@anl.gov RI Chen, Xueyuan/C-5613-2012 OI Chen, Xueyuan/0000-0003-0493-839X NR 20 TC 27 Z9 27 U1 1 U2 16 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD JUN PY 2003 VL 14 IS 6 BP 670 EP 674 AR PII S09570-4484(03)59671-4 DI 10.1088/0957-4484/14/6/320 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 698RA UT WOS:000184011500020 ER PT J AU Rogan, RC Tamura, N Swift, GA Ustundag, E AF Rogan, RC Tamura, N Swift, GA Ustundag, E TI Direct measurement of triaxial strain fields around ferroelectric domains using X-ray microdiffraction SO NATURE MATERIALS LA English DT Article ID BARIUM-TITANATE; SINGLE-CRYSTALS; STRESS; BATIO3; WALLS; MICROSCOPY; CERAMICS AB Ferroelectric materials, such as BaTiO3, have piezoelectric properties that make them attractive for microelectronic and sensing applications(1). It is well known that the application of mechanical stress or electric field can alter the domain structure in ferroelectrics(1-6). Indeed, the constitutive behaviour of a ferroelectric is largely governed by the formation, movement and interaction of its domains. Therefore, it is crucial that the micromechanics of domains and their effect on internal stresses in ferroelectrics be understood. Here we show that the emerging technique of scanning X-ray microdiffraction(7) can be used to measure directly, for the first time, the local triaxial strain fields around 90degrees domains in single-crystal BaTiO3. Specifically, residual strain maps in a region surrounding an isolated, approximately 40 mum wide, 90degrees domain were obtained with 3 mum resolution, revealing significant residual strains. This information is critical for accurate micromechanical modelling of domain behaviour in ferroelectrics. C1 CALTECH, Dept Mat Sci, Keck Lab, Pasadena, CA 91125 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Rogan, RC (reprint author), CALTECH, Dept Mat Sci, Keck Lab, Pasadena, CA 91125 USA. RI Ustundag, Ersan/C-1258-2009 OI Ustundag, Ersan/0000-0002-0812-7028 NR 21 TC 55 Z9 55 U1 3 U2 31 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD JUN PY 2003 VL 2 IS 6 BP 379 EP 381 DI 10.1038/nmat901 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 688CR UT WOS:000183415700012 PM 12754499 ER PT J AU Manna, L Milliron, DJ Meisel, A Scher, EC Alivisatos, AP AF Manna, L Milliron, DJ Meisel, A Scher, EC Alivisatos, AP TI Controlled growth of tetrapod-branched inorganic nanocrystals SO NATURE MATERIALS LA English DT Article ID CDSE NANOCRYSTALS; SEMICONDUCTOR NANOCRYSTALS; OPTICAL-PROPERTIES; NANOPARTICLES; MONODISPERSE; NANORODS; CRYSTALS; POLYMER AB Nanoscale materials are currently being exploited as active components in a wide range of technological applications in various fields, such as composite materials(1,2), chemical sensing(3), biomedicine(4-6), optoelectronics(7-9) and nanoelectronics(10-12). Colloidal nanocrystals are promising candidates in these fields, due to their ease of fabrication and processibility. Even more applications and new functional materials might emerge if nanocrystals could be synthesized in shapes of higher complexity than the ones produced by current methods (spheres, rods, discs)(13-19). Here, we demonstrate that polytypism, or the existence of two or more crystal structures in different domains of the same crystal, coupled with the manipulation of surface energy at the nanoscale, can be exploited to produce branched inorganic nanostructures controllably. For the case of CdTe, we designed a high yield, reproducible synthesis of soluble, tetrapod-shaped nanocrystals through which we can independently control the width and length of the four arms. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. INFM, Natl Nanotechnol Lab, I-73100 Lecce, Italy. RP Manna, L (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Milliron, Delia/D-6002-2012; Manna, Liberato/G-2339-2010; Alivisatos , Paul /N-8863-2015 OI Manna, Liberato/0000-0003-4386-7985; Alivisatos , Paul /0000-0001-6895-9048 NR 32 TC 1056 Z9 1065 U1 25 U2 326 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD JUN PY 2003 VL 2 IS 6 BP 382 EP 385 DI 10.1038/nmat902 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 688CR UT WOS:000183415700013 PM 12764357 ER PT J AU Letant, SE Hart, BR Van Buuren, AW Terminello, LJ AF Letant, SE Hart, BR Van Buuren, AW Terminello, LJ TI Functionalized silicon membranes for selective bio-organism capture SO NATURE MATERIALS LA English DT Article ID GOLD NANOTUBULE MEMBRANES; POROUS SILICON; NANOPOROUS MEMBRANES; TRANSPORT-PROPERTIES; IMMUNOISOLATION; ALKENES; THIOLS AB Membranes with various pore size, length, morphology and density have been synthesized from diverse materials(1-5) for size-exclusion-based separation. An example is the sterilization of intravenous lines by exclusion of bacteria and viruses using polyvinylidene fluoride membranes with 0.1-mum-diameter pores. Chemically specific filtration has recently been addressed for small molecules(6-10). Nevertheless, specific bio-organism immobilization and detection remains a great technical challenge in many biomedical applications, such as decontamination or analysis of air and liquids such as drinking water and body fluids. To achieve this goal, materials with controlled pore diameter, length and surface chemistry are required. In this letter, we present the first functionalized silicon membranes and demonstrate their ability to selectively capture simulated bio-organisms. These extremely versatile and rigid devices open the door to a new class of materials that are able to recognize the external fingerprints of bio-organisms-such as size and outer membrane proteins-for specific capture and detection applications. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP Letant, SE (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. NR 22 TC 50 Z9 50 U1 5 U2 37 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD JUN PY 2003 VL 2 IS 6 BP 391 EP 396 DI 10.1038/nmat888 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 688CR UT WOS:000183415700015 PM 12717430 ER PT J AU Oda, MN Forte, TM Ryan, RO Voss, JC AF Oda, MN Forte, TM Ryan, RO Voss, JC TI The C-terminal domain of apolipoprotein A-I contains a lipid-sensitive conformational trigger SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID CHOLESTEROL ACYLTRANSFERASE ACTIVATION; HEMAGGLUTININ MEMBRANE GLYCOPROTEIN; HIGH-DENSITY-LIPOPROTEIN; LOOP-GAP RESONATOR; INFLUENZA HEMAGGLUTININ; PHOSPHOLIPID-BINDING; STRUCTURAL-ANALYSIS; SPIN; LECITHIN; MUTAGENESIS AB Exchangeable apolipoproteins can convert between lipid-free and lipid-associated states. The C-terminal domain of human apolipoprotein A-I ( apoA-I) plays a role in both lipid binding and self-association. Site-directed spin-label electron paramagnetic resonance spectroscopy was used to examine the structure of the apoA-I C terminus in lipid-free and lipid-associated states. Nitroxide spin-labels positioned at defined locations throughout the C terminus were used to define discrete secondary structural elements. Magnetic interactions between probes localized at positions 163, 217 and 226 in singly and doubly labeled apoA-I gave inter-and intramolecular distance information, providing a basis for mapping apoA-I tertiary and quaternary structure. Spectra of apoA-I in reconstituted HDL revealed a lipid-induced transition of defined random coils and - strands into - helices. This conformational switch is analogous to triggered events in viral fusion proteins and may serve as a means to overcome the energy barriers of lipid sequestration, a critical step in cholesterol efflux and HDL assembly. C1 Childrens Hosp Oakland, Res Inst, Oakland, CA 94609 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Biol Chem, Davis, CA 95616 USA. RP Oda, MN (reprint author), Childrens Hosp Oakland, Res Inst, Oakland, CA 94609 USA. OI Voss, John/0000-0001-9279-209X NR 35 TC 97 Z9 97 U1 0 U2 6 PU NATURE PUBLISHING GROUP PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUN PY 2003 VL 10 IS 6 BP 455 EP 460 DI 10.1038/nsb931 PG 6 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 683GT UT WOS:000183140600011 PM 12754494 ER PT J AU Kenyon, GT Travis, BJ Marshak, DW AF Kenyon, GT Travis, BJ Marshak, DW TI Role of synaptic feedback and intrinsic voltage-gated currents in shaping cone light responses SO NEUROCOMPUTING LA English DT Article DE retina; computer simulation; outer plexiform layer; horizontal cell ID HORIZONTAL CELLS; CAT RETINA; TRANSDUCTION; SIMULATION; CHANNELS AB A model of the outer primate retina was used to investigate how cone light responses could be shaped by both synaptic feedback from horizontal cells and intrinsic voltage-gated conductances. Published data was used to estimate the photoconductance, convergence/divergence ratios, synaptic transfer functions, passive membrane properties and voltage-gated conductances, the latter using a Levenberg-Marquardt search algorithm. When the cone resting potential was sufficiently depolarized, synaptic feedback from horizontal cells could account for the flash response measured experimentally. Voltage-gated conductances were not significantly activated during the flash response but rather maintained the cone membrane potential inside a narrow physiological range. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Texas, Hlth Sci Ctr, Dept Neurobiol & Anat, Houston, TX 77030 USA. RP Kenyon, GT (reprint author), Los Alamos Natl Lab, P-21 Biophys MS D454, Los Alamos, NM 87545 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-2312 J9 NEUROCOMPUTING JI Neurocomputing PD JUN PY 2003 VL 52-4 BP 125 EP 133 DI 10.1016/S0925-2312(02)00790-7 PG 9 WC Computer Science, Artificial Intelligence SC Computer Science GA 689VU UT WOS:000183514300020 ER PT J AU Petti, DA Buongiorno, J Maki, JT Hobbins, RR Miller, GK AF Petti, DA Buongiorno, J Maki, JT Hobbins, RR Miller, GK TI Key differences in the fabrication, irradiation and high temperature accident testing of US and German TRISO-coated particle fuel, and their implications on fuel performance SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 1st International Topical Meeting on High Temperature Reactor Technology CY APR 22-24, 2002 CL PETTEN, NETHERLANDS AB Historically, the irradiation performance of TRISO-coated gas reactor particle fuel in Germany has been superior to that in the US. German fuel generally has displayed gas release values during irradiation three orders of magnitude lower than US fuel. Thus, we have critically examined the TRISO-coated fuel fabrication processes in the US and Germany and the associated irradiation database with a goal of understanding why the German fuel behaves acceptably, why the US fuel has not faired as well, and what process/production parameters impart the reliable performance to this fuel form. The postirradiation examination results are also reviewed to identify failure mechanisms that may be the cause of the poorer US irradiation performance. This comparison will help determine the roles that particle fuel process/product attributes and irradiation conditions (burnup, fast neutron fluence, temperature. degree of acceleration) have on the behavior of the fuel during irradiation and provide a more quantitative linkage between acceptable processing parameters, as-fabricated fuel properties and subsequent in-reactor performance. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Petti, DA (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 15 TC 106 Z9 110 U1 7 U2 27 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD JUN PY 2003 VL 222 IS 2-3 BP 281 EP 297 DI 10.1016/S0029-5493(03)00033-5 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 678HE UT WOS:000182860400016 ER PT J AU Rodriguez, C Baxter, A McEachern, D Fikani, M Venneri, F AF Rodriguez, C Baxter, A McEachern, D Fikani, M Venneri, F TI Deep-Burn: making nuclear waste transmutation practical SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 1st International Topical Meeting on High Temperature Reactor Technology CY APR 22-24, 2002 CL PETTEN, NETHERLANDS AB In the Deep-Burn concept, destruction of the transuranic component of light water reactor (LWR) waste is carried out in one burn-up cycle. accomplishing the virtually complete destruction of weapons-usable materials (Plutonium-239), and up to 90% of all transuranic waste, including the near totality of Neptunium-237 (the most mobile actinide in the repository environment) and its precursor. Americium-241. Waste destruction would be performed rapidly, without multiple reprocessing of plutonium, thus eliminating the risks of repeated handling of weapons-usable material and limiting the generation of secondary waste. There appears to be no incentive in continuing the destruction of waste beyond this level. An essential feature of the Deep-burn Transmuter is the use of ceramic-coated fuel particles that provide very strong containment and are highly resistant to irradiation, thereby allowing very extensive destruction levels ("Deep Burn") in the one pass, using gas-cooled modular helium reactor (MHR) technology developed for high-efficiency energy production. The fixed moderator (graphite) and neutronically transparent coolant (helium) provide a unique neutron energy spectrum to cause Deep-Burn, and inherent safety features, specific to the destruction of nuclear waste, that are not found in any other design. Deep-Burn technology could be available for deployment in a relatively short time, thus contributing effectively to waste problem solutions. Extensive modeling effort has led to conceptual Deep-Burn designs that can achieve high waste destruction levels (70% in critical mode, 90% in with a supplemental subcritical step) within the operational envelope of commercial MHR operation, including long refueling intervals and the highly efficient production of energy (approximately 50%). To the plant operator, a Deep-burn Transmuter will be identical to its commercial reactor counterpart. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Gen Atom Co, San Diego, CA 92186 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rodriguez, C (reprint author), Gen Atom Co, San Diego, CA 92186 USA. EM Carmelo.Rodriguez@gat.com NR 10 TC 34 Z9 34 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD JUN PY 2003 VL 222 IS 2-3 BP 299 EP 317 DI 10.1016/S0029-5493(03)00034-7 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 678HE UT WOS:000182860400017 ER PT J AU Strait, EJ Bialek, J Bogatu, N Chance, M Chu, MS Edgell, D Garofalo, AM Jackson, GL Jensen, TH Johnson, LC Kim, JS La Haye, RJ Navratil, G Okabayashi, M Reimerdes, H Scoville, JT Turnbull, AD Walker, ML AF Strait, EJ Bialek, J Bogatu, N Chance, M Chu, MS Edgell, D Garofalo, AM Jackson, GL Jensen, TH Johnson, LC Kim, JS La Haye, RJ Navratil, G Okabayashi, M Reimerdes, H Scoville, JT Turnbull, AD Walker, ML CA DIII-D Team TI Resistive wall stabilization of high-beta plasmas in DIII-D SO NUCLEAR FUSION LA English DT Article ID ACTIVE FEEDBACK STABILIZATION; MODES; TOKAMAKS; ROTATION; LIMIT AB Recent DIII-D experiments show that ideal kink-modes can be stabilized at high beta by a resistive wall, with sufficient plasma rotation. However, the resonant response to static magnetic field asymmetries by a marginally stable resistive wall mode can lead to strong damping of the rotation. Careful reduction of such asymmetries has allowed plasmas with beta well above the ideal MHD no-wall limit, and approaching the ideal-wall limit, to be sustained for durations exceeding 1 s. Feedback control can improve plasma stability by direct stabilization of the resistive wall mode or by reducing magnetic field asymmetry. Assisted by plasma rotation, direct feedback control of resistive wall modes with growth rates more than five times faster than the characteristic wall time has been observed. These results open a new regime of tokamak operation above the free-boundary stability limit, accessible by a combination of plasma rotation and feedback control. C1 Gen Atom Co, San Diego, CA 92186 USA. Columbia Univ, New York, NY 10027 USA. Fartech Inc, San Diego, CA 92121 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Strait, EJ (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. OI Walker, Michael/0000-0002-4341-994X NR 26 TC 68 Z9 68 U1 2 U2 8 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2003 VL 43 IS 6 BP 430 EP 440 AR PII S0029-5515(03)62677-3 DI 10.1088/0029-5515/43/6/306 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 696ZE UT WOS:000183917100006 ER PT J AU Chu, MS Chance, MS Glasser, AH Okabayashi, M AF Chu, MS Chance, MS Glasser, AH Okabayashi, M TI Normal mode approach to modelling of feedback stabilization of the resistive wall mode SO NUCLEAR FUSION LA English DT Article ID DIII-D; TOKAMAKS; GEOMETRY; PLASMAS AB Feedback stabilization of the resistive wall mode (RWM) of a plasma in a general feedback configuration is formulated in terms of the normal modes of the plasma-resistive wall system. The growth/damping rates and the eigenfunctions of the normal modes are determined by an extended energy principle for the plasma during its open (feedback) loop operation. A set of equations are derived for the time evolution of these normal modes with currents in the feedback coils. The dynamics of the feedback system is completed by the prescription of the feedback logic. The feasibility of the feedback is evaluated by using the Nyquist diagram method or by solving the characteristic equations. The elements of the characteristic equations are formed from the growth and damping rates of the normal modes, the sensor matrix of the perturbation fluxes detected by the sensor loops, the excitation matrix of the energy input to the normal modes by the external feedback coils, and the feedback logic. (The RWM is also predicted to be excited by an external error field to a large amplitude when it is close to marginal stability.) This formulation has been implemented numerically and applied to the DIII-D tokamak. It is found that feedback with poloidal sensors is much more effective than feedback with radial sensors. Using radial sensors, increasing the number of feedback coils from a central band on the outboard side to include an upper and a lower band can substantially increase the effectiveness of the feedback system. The strength of the RWM that can be stabilized is increased from gammatau(w) = 1 to 30 (gamma is the growth rate of the RWM in the absence of feedback and tau(w) is the resistive wall time constant) Using poloidal sensors, just one central band of feedback coils is sufficient for the stabilization of the RWM with gammatau(w) = 30. C1 Gen Atom Co, San Diego, CA 92186 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chu, MS (reprint author), Gen Atom Co, San Diego, CA 92186 USA. NR 14 TC 59 Z9 59 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2003 VL 43 IS 6 BP 441 EP 454 AR PII S0029-5515(03)63261-8 DI 10.1088/0029-5515/43/6/307 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 696ZE UT WOS:000183917100007 ER PT J AU Testa, D Fu, GY Jaun, A Fasoli, A Sauter, O AF Testa, D Fu, GY Jaun, A Fasoli, A Sauter, O CA JET-EFDA TI Experimental test of damping models for n=1 toroidal Alfven eigenmodes in JET SO NUCLEAR FUSION LA English DT Article ID JOINT EUROPEAN TORUS; TOKAMAK PLASMAS; WAVES AB The damping rate of the n = 1 toroidal Alfven eigenmodes (TAE) mode in Ohmic-heated JET plasmas has been measured and compared with the prediction of the kinetic NOVA-K code, which includes electron and ion Landau damping of the global shear-Alfven wave field, collisional damping, and radiative damping. It was found that the calculated damping rate is too small to account for the measured value under these experimental conditions. A relatively weak dependence of the damping rate on the normalized Larmor radius is observed experimentally. C1 EPFL, CRPP, Assoc Euratom Confederat Suisse, CH-1015 Lausanne, Switzerland. MIT, Plasma Sci & Fus Ctr, Boston, MA USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Royal Inst Technol, NADA VR, EURATOM Assoc, Stockholm, Sweden. RP Testa, D (reprint author), EPFL, CRPP, Assoc Euratom Confederat Suisse, CH-1015 Lausanne, Switzerland. NR 18 TC 19 Z9 19 U1 1 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2003 VL 43 IS 6 BP 479 EP 482 AR PII S0029-5155(03)63273-4 DI 10.1088/0029-5515/43/6/310 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 696ZE UT WOS:000183917100010 ER PT J AU Park, W Breslau, J Chen, J Fu, GY Jardin, SC Klasky, S Menard, J Pletzer, A Stratton, BC Stutman, D Strauss, HR Sugiyama, LE AF Park, W Breslau, J Chen, J Fu, GY Jardin, SC Klasky, S Menard, J Pletzer, A Stratton, BC Stutman, D Strauss, HR Sugiyama, LE TI Nonlinear simulation studies of tokamaks and STs SO NUCLEAR FUSION LA English DT Article ID HIGH-BETA DISRUPTION; MAGNETOHYDRODYNAMICS; PLASMAS AB The multilevel physics, massively parallel plasma simulation code, M3D has been used to study spherical toris (STs) and tokamaks. The magnitude of outboard shift of density profiles relative to electron temperature profiles seen in NSTX under strong toroidal flow is explained. Internal reconnection events in ST discharges can be classified depending on the crash mechanism, just as in tokamak discharges; a sawtooth crash, disruption due to stochasticity, or high-beta disruption. Toroidal shear flow can reduce linear growth of internal kink. It has a strong stabilizing effect nonlinearly and causes mode saturation if its profile is maintained, e.g. through a fast momentum source. Normally, however, the flow profile itself flattens during the reconnection process, allowing a complete reconnection to occur. In some cases, the maximum density and pressure spontaneously occur inside the island and cause mode saturation. Gyrokinetic hot particle/MHD hybrid studies of NSTX show the effects of fluid compression on a fast-ion driven n = 1 mode. MHD studies of recent tokamak experiments with a central current hole indicate that the current clamping is due to sawtooth-like crashes, but with n = 0. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. NYU, New York, NY 10012 USA. MIT, Cambridge, MA 02139 USA. RP Park, W (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Jardin, Stephen/E-9392-2010; Stutman, Dan/P-4048-2015; OI Menard, Jonathan/0000-0003-1292-3286 NR 14 TC 22 Z9 22 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2003 VL 43 IS 6 BP 483 EP 489 AR PII S0029-5515(03)63260-6 DI 10.1088/0029-5515/43/6/311 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 696ZE UT WOS:000183917100011 ER PT J AU Micklich, BJ Smith, DL Massey, TN Fink, CL Ingram, D AF Micklich, BJ Smith, DL Massey, TN Fink, CL Ingram, D TI Measurement of thick-target high-energy gamma-ray yields from the F-19(p,alpha gamma)O-16 reaction SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE thick target photon yield; high-energy gamma-ray source; F-19(p,alpha gamma)O-16 reaction; NaI detector response function ID T FUSION NEUTRONS; WATER AB We measured the photon yields for proton energies between 1.5 and 4.25 MeV using both CaF2 and MgF2 solid targets and SF6 gas targets. Photon yields were measured using a 7.62 cm x 7.62 cm NaI scintillator detector. Detector response functions for these three, individual gamma-rays were calculated using the Monte Carlo code MCNP-4C. The relative intensities of the three gamma-rays were determined by a least-squares fit of these response functions to the data in a selected region of the pulse-height spectrum. A maximum photon yield of 6.0 x 10(7) gamma/muC/sr (at 0degrees) was determined for the sum of these three gamma-rays at an effective proton energy; of 4.0 MeV. The contribution of the individual lines to the total photon yield depends strongly on the incident proton energy. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. Ohio Univ, Dept Phys & Astron, Edwards Accelerator Lab, Athens, OH 45701 USA. RP Micklich, BJ (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 1 EP 4 DI 10.1016/50168-9002(03)01006-4 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700003 ER PT J AU Fink, CL Smith, DL Micklich, BJ Massey, TN AF Fink, CL Smith, DL Micklich, BJ Massey, TN TI Gamma rays produced by 1.75-to 4-MeV proton bombardment of thick aluminum targets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE thick target photon yield; high energy photons ID YIELDS AB In the few-MeV energy range below the (p,n) threshold, gamma rays are produced from proton bombardment of aluminum via the Al-27(p,p'gamma)Al-27, Al-27(p, alpha, gamma)Mg-24, and Al-27(p, gamma)Si-28 reactions. Thick-target gamma-ray yield data are important for various applications, including radiation shielding near accelerators and gamma-ray background interference in;experiments that focus on other materials. We measured p+Al gamma-ray spectra over the photon energy range 0.5-15 MeV and at 0 and 90 laboratory angle relative to the incident proton beam. In the experiment, monoenergetic proton beams of 1.75, 2, 2.5, 3, 3.5, and 4 MeV irradiated thick stopping targets of pure aluminum. The resulting gamma rays were detected by 7.62 x 7.62 cm(2) NaI scintillation detectors. The spectra were unfolded using detector response functions calculated with the Monte Carlo code MCNP-4C. We report gamma-ray spectra and tabulated gamma-ray yields that can be used in applications that involve protons incident on thick aluminum targets at energies less than or equal to 4 MeV. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. Ohio Univ, Dept Phys & Astron, Edwards Accelerator Lab, Athens, OH 45701 USA. RP Micklich, BJ (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 5 EP 8 DI 10.1016/S0168-9002(03)01007-6 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700004 ER PT J AU Wallace, S Stephan, AC Womble, PC Begtrup, G Dai, S AF Wallace, S Stephan, AC Womble, PC Begtrup, G Dai, S TI Spectra of fast neutrons using a lithiated glass film on silicon SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE fast neutron detector; lithiated sol-gel glass; differential die-away detection; D-T neutron generator; Pu-Be source AB Experimental results of a neutron detector manufactured by coating a silicon charged particle detector with a film of lithiated glass are presented. The silicon surface barrier detector (SBD) responds to the Li-6(n, alpha)triton reaction products generated in the thin film of lithiated glass entering the SBD. Neutron spectral information is present in the pulse height spectrum. An energy response is seen that clearly shows that neutrons from a Pu-Be source and from a deuterium-tritium (D-T) pulsed neutron generator can be differentiated and counted above a gamma background. The significant result is that the fissile content within a container can be measured using a pulsed D-T neutron generator using the neutrons that are counted in the interval between the pulses. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Neutron Sci Inc, Knoxville, TN 37932 USA. Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. Western Kentucky Univ, Bowling Green, KY 42101 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wallace, S (reprint author), Neutron Sci Inc, Knoxville, TN 37932 USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 5 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 16 EP 19 DI 10.1016/S0168-9002(03)01010-6 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700007 ER PT J AU Hertz, KL Hilton, NR Lund, JC Van Scyoc, JM AF Hertz, KL Hilton, NR Lund, JC Van Scyoc, JM TI Alpha-emitting radioisotopes for switchable neutron generators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE radioisotopes; neutron source AB Traditionally, radioisotopic neutron generators mix an alpha-emitting radioisotope with beryllium. The disadvantage of such an alpha-Be source is that they emit neutrons at a steady rate even when stored. These conventional generators are extremely awkward to use in many applications because of the neutron shielding required to prevent exposure to personnel and sensitive electronics. Recently, at our laboratory acid others, the possibility of using switchable radioactive neutron sources has been investigated. These sources rely on a mechanical operation to separate the alpha-emitting radioisotope from the Be target, thus allowing the source to be switched on and off. The utility of these new switchable sources is critically dependent on the selection of the alpha-emitting radioisotope. In this paper we discuss issues that determine the desirability of an alpha-emitting source for a switchable:neutron generator, and select alpha emitters that are best suited for use in this application. (C) 2003 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Hertz, KL (reprint author), Sandia Natl Labs, POB 969,MS 9402, Livermore, CA 94551 USA. 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 41 EP 45 DI 10.1016/S0168-9002(03)01016-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700013 ER PT J AU De Lurgio, PM Klann, RT Fink, CL McGregor, DS Thiyagarajan, P Naday, I AF De Lurgio, PM Klann, RT Fink, CL McGregor, DS Thiyagarajan, P Naday, I TI A neutron detector to monitor the intensity of transmitted neutrons for small-angle neutron scattering instruments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE transmission; thermal nuetron; detector; GaAs; solid state AB A semiconductor-based neutron detector was developed at Argonne National Laboratory (ANL) for use as a neutron beam monitor for small-angle neutron scattering instruments. The detector is constructed using a coating of 1 B on a gallium-arsenide semiconductor detector and is mounted directly within a cylindrical (2.2 cm dia. and 4.4 cm long) enriched (B4C)-B-10 beam stop in the time-of-flight Small Angle Neutron Diffractometer (SAND) instrument at the Intense Pulsed Neutron Source (IPNS) facility at ANL. The neutron beam viewed by the SAND is from a pulsed spallation source moderated by a solid methane moderator that produces useful neutrons in the wavelength range of 0.5-14 Angstrom. The SAND instrument uses all detected neutrons in the above wavelength range sorted by time-of-flight into 68 constant DeltaT/T = 0.05 channels. This new detector continuously monitors the transmitted neutron beam through the sample during scattering measurements and takes data concurrently with the other detectors in the instrument. The B-10 coating on the GaAs detector allows the detection of the cold neutron spectrum with reasonable efficiency. This paper describes the details of the detector fabrication, the beam stop monitor design, and includes a discussion of results from preliminary tests using the detector during several run cycles at the IPNS. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60561 USA. Kansas State Univ, Manhattan, KS 66506 USA. RP De Lurgio, PM (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60561 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 46 EP 49 DI 10.1016/S0168-9002(03)01017-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700014 ER PT J AU Belian, AP Browne, MC Clay, W Ensslin, N Geist, W Nguyen, H Ianakiev, K Mayo, D Panowski, S Russo, P AF Belian, AP Browne, MC Clay, W Ensslin, N Geist, W Nguyen, H Ianakiev, K Mayo, D Panowski, S Russo, P TI An approach to multiplicity counting for a versatile new sensor for plutonium assay with a very short die-away time, and independent measurements of neutrons and gamma rays SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE neutron; coincidence; multiplicity; plutonium; assay; directional AB A unique detector design incorporating a Li-6-based capture medium, ZnS scintillator, and wavelength shifting optical fibers is the basis of a new neutron coincidence counter for measurements of plutonium in highly impure residues. The sensor elements have a high efficiency for detecting neutrons and exhibit excellent gamma-ray discrimination based on pulse-shape analysis. The short die-away time of the counter that is based on these detector elements allows coincidence-gate settings shorter than 10 mus. This qualifies the technology for measurements of materials with high yields of uncorrelated neutrons from Am-241(alpha,n) reactions. The characteristics of the new neutron counter will be illustrated with test data from measurements of plutonium, Cf-252, and gamma-ray sources. The integrated electronics design of the new detector also permits the simultaneous but independent measurement of both neutrons and gamma rays. Recent test results that illustrate some unique applications of the sensor's versatility will also be presented. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Belian, AP (reprint author), Los Alamos Natl Lab, NIS-5,POB 1663,MS E-540, Los Alamos, NM 87545 USA. NR 5 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 54 EP 57 DI 10.1016/S0168-9002(03)01019-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700016 ER PT J AU Shah, KS Glodo, J Klugerman, M Cirignano, L Moses, WW Derenzo, SE Weber, MJ AF Shah, KS Glodo, J Klugerman, M Cirignano, L Moses, WW Derenzo, SE Weber, MJ TI LaCl3 : Ce scintillator for gamma-ray detection SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MI DE scintillation crystals; rare-earth trihalides; LaCl3 : Ce; gamma-detection AB In this paper, we report on a relatively new cerium-doped scintillator-LaCl3 for gamma-ray spectroscopy. Crystals of this scintillator have been grown using Bridgman method.. This material when doped with 10% cerium has high light output (similar to50,000 photons/MeV) and fast principal decay time constant (similar to20 ns). Furthermore, it shows excellent, energy resolution for gamma-ray detection. For example, energy resolution as low as 3.2% (FWHM) has been achieved with 662 keV photons (Cs-137 source) at room temperature. Also, high timing resolution (264 ps-FWHM) has been recorded with LaCl3-PMT and BaF2-PMT detectors operating in coincidence using 511 keV positron annihilation gamma-ray pairs. Details of crystal growth, scintillation properties, and variation of these properties with cerium concentration are also reported. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Radiat Monitoring Devices Inc, Watertown, MA 02472 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Shah, KS (reprint author), Radiat Monitoring Devices Inc, Watertown, MA 02472 USA. EM kshah@rmdinc.com NR 7 TC 62 Z9 75 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 76 EP 81 DI 10.1016/S0168-9002(03)01024-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700021 ER PT J AU Derenzo, SE Weber, MJ Bourret-Courchesne, WE Klintenberg, MK AF Derenzo, SE Weber, MJ Bourret-Courchesne, WE Klintenberg, MK TI The quest for the ideal inorganic scintillator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE scintillators; semiconductors; scintillation mechanisms ID TEMPERATURE-DEPENDENCE; CDS-IN; ZNO AB The past half century has witnessed the discovery of many new inorganic scintillator materials and numerous advances in our understanding of the basic physical processes governing the transformation of ionizing radiation into scintillation light. Whereas scintillators are available with a good combination of physical properties, none provides the desired combination of stopping power, light output, and decay time. A review of the numerous scintillation mechanisms of known inorganic scintillators reveals why none of them is both bright and fast. The mechanisms of radiative recombination in wide-band gap direct semiconductors, however, remain relatively unexploited for scintillators. We describe how suitably doped semiconductor scintillators could provide a combination of high light output, short decay time, and linearity of response that approach fundamental limits. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Derenzo, SE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,Mail Stop 55-121, Berkeley, CA 94720 USA. NR 28 TC 122 Z9 125 U1 4 U2 46 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 111 EP 117 DI 10.1016/S0168-9002(03)01031-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700028 ER PT J AU Tindall, C Hau, L Luke, PN AF Tindall, C Hau, L Luke, PN TI Evaluation of Si(Li) detectors for use in Compton telescopes SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE lithium-drifted silicon; Si(Li) detectors; advanced compton telescope; gamma-ray spectroscopy; Si(Li) strip detectors ID TEMPERATURE; SILICON AB Si(Li) detectors are currently being developed for use in large Compton telescopes. A major advantage of silicon when compared with germanium is its ability to operate at significantly higher temperatures. To determine the feasibility of using Si(Li) detectors in a Compton telescope, their performance as a function of temperature has been studied. We present leakage current, noise data and gamma-ray spectral performance at various temperatures for single 6-mm-thick planar devices. It has been determined that for detectors without a guard ring, the noise began to rise significantly around 210K. Adding a guard ring improved the leakage current by about an order of magnitude and reduced the total noise (detector plus electronics) by about 25%. The noise of the detectors with similar to 130 mm(2) area and a guard ring did not exceed our performance goal of 2 keV FWHM until the temperature was approximately 240 K. For 122 keV gamma rays, no evidence of ballistic deficit was seen at 8 mus peaking time and bias voltages corresponding to an internal electric field of similar to1150V/cm. Some evidence of ballistic deficit was seen for 662 keV gamma rays at temperatures above 220 K. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. RP Tindall, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 9 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 130 EP 135 DI 10.1016/S0168-9002(03)01035-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700032 ER PT J AU Hau, ID Tindall, C Luke, PN AF Hau, ID Tindall, C Luke, PN TI New contact development for Si(Li) orthogonal-strip detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE lithium drift silicon; amorphous silicon contact; boron implanted contact; thermal annealing; gamma-ray detector; orthogonal-strip detector ID SILICON AB At present, the contacts generally used for lithium-drifted silicon detectors consist of a diffused lithium layer (n-type) and a gold surface barrier (p-type). These contacts work well for unsegmented detectors. However, they both have disadvantages if used for segmented detectors. For this reason, we. are developing new types of contacts that will be more, robust and easier to segment. To replace the lithium n-type contact, we are using a thin. layer of amorphous silicon (alpha-Si) with metalization on top. The new p-type contact consists of boron implanted into, the silicon and annealed at the relatively low temperature of 500 degreesC. The implantation and annealing is carried out as the first step in the process, prior to lithium drifting. Detectors have been fabricated using the new contacts both with and without a guard ring. They performed as well as detectors with standard contacts at operating temperatures between 80 and 240 K. We will present data on the leakage current vs. temperature, isolation resistance between the guard ring and the center contact versus temperature and bias voltage, electronic noise and energy resolution versus temperature, as well as Co-57 spectra. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. RP Tindall, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 9 TC 9 Z9 9 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 148 EP 154 DI 10.1016/S0168-9002(03)01039-8 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700036 ER PT J AU Moore, EF Ahmad, I Amman, J Carpenter, MP Fischer, SM Janssens, RVF Khoo, TL Lauritsen, T Lister, CJ Mukherjee, G Nisius, D Sangsingkeow, P Sienko, T Truett, B Underwood, TA AF Moore, EF Ahmad, I Amman, J Carpenter, MP Fischer, SM Janssens, RVF Khoo, TL Lauritsen, T Lister, CJ Mukherjee, G Nisius, D Sangsingkeow, P Sienko, T Truett, B Underwood, TA TI Development of a gamma-ray box (GARBO) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE germanium detectors; gamma-ray spectroscopy; Monte-Carlo simulations AB Isomer decays, beta-gamma and electron-gamma spectroscopy, alpha-gamma fine structure studies, and Coulomb excitation are cases of nuclear structure experiments where the ideal detector is a compact, highly segmented, very efficient germanium (Ge) detector box. In order to develop such a structure, we are working,on the R&D of large, segmented, high-purity planar Ge strip detectors (HPGeDSSD) which form the walls of such a box. We have developed a 92 turn x 92 mm,,x 20 mm HPGeDSSD, which has 16 x 16 orthogonal strips of 5 mm width. We are in the process of designing a focal plane detector for the Argonne fragment mass analyzer which consists of a five-sided box, each side having a HPGeDSSD backed by a large segmented clover HPGe detector. MCNP simulations indicate this detector would have an efficiency of similar to60 % for 122 keV gamma rays and similar to15 % for 1.33 MeV radiation, which is ideal for studying the decays of nuclei far from stability that are usually produced with very low cross-sections. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. De Paul Univ, Dept Phys, Chicago, IL 60614 USA. BIR, Lincolnshire, IL 60069 USA. Ortec, Oak Ridge, TN 37831 USA. Purdue Univ Calumet, Dept Chem & Phys, Hammond, IN 46323 USA. RP Moore, EF (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 2 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 163 EP 166 DI 10.1016/S0168-9002(03)01042-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700039 ER PT J AU Becker, JA Cork, CP Fabris, L Madden, NW AF Becker, JA Cork, CP Fabris, L Madden, NW TI Portable, low-power, mechanically cooled Ge spectrometer SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN AB A light-weight portable mechanically cooled gamma-ray spectrometer has been constructed and tested. The spectrometer is based on a high-purity n-type Ge coaxial crystal, similar to 5 cm long x 5 cm diameter, a small, low-power Stirling cycle microcooler, and a low-power custom electronics package. The energy resolution of the spectrometer is similar to 3.5 keV at E-gamma = 662 keV, the power requirements are similar to 15 W DC, and the combined weight of the Ge, housing, and controller is approximately 10 pounds. The spectrometer qualifies therefore as "hand held". It is suitable for field operations, because of its light-weight, low-power draw, and operational lifetime. The microcooler itself has a MTBF > 30,000 h, and the spectrometer runs for several months (at least 6) before a 2 day recycle is required. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Becker, JA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 1 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 167 EP 169 DI 10.1016/S0168-9002(03)01043-X PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700040 ER PT J AU Sullivan, CJ He, Z Knoll, GF Tepper, G Wehe, DK AF Sullivan, CJ He, Z Knoll, GF Tepper, G Wehe, DK TI A high pressure xenon gamma-ray spectrometer using a coplanar anode configuration SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE radiation detectors; gamma-ray spectrometers; high pressure xenon; gas ionization chamber ID SEMICONDUCTOR-DETECTORS; ENERGY RESOLUTION; ELECTRODES AB A new design of a high pressure xenon ionization chamber has been fabricated in an attempt to eliminate the problems associated with acoustical vibrations of the Frisch grid. The function of the traditional Frisch grid has been accomplished by employing a coplanar anode system capable of single polarity charge sensing. Two different detector designs have been fabricated using both cylindrical and parallel plate geometries. Each is filled with highly purified xenon gas at a pressure of approximately 57 atm. The designs of these new spectrometers and their measured characteristics will be presented. (C) 2003 Published by Elsevier Science B.V. C1 Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. Virginia Commonwealth Univ, Dept Chem Engn, Richmond, VA 23284 USA. RP Sullivan, CJ (reprint author), Los Alamos Natl Lab, POB 1663,MS J562, Los Alamos, NM 87545 USA. OI Sullivan, Clair/0000-0003-4827-5348 NR 8 TC 10 Z9 10 U1 2 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 JUN 1 PY 2003 VL 505 IS 1-2 BP 238 EP 241 DI 10.1016/S0168-9002(03)01060-X PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700057 ER PT J AU Simoes, PCPS Covita, DS Veloso, JFCA dos Santos, JMF Morgado, RE AF Simoes, PCPS Covita, DS Veloso, JFCA dos Santos, JMF Morgado, RE TI A new method for pulse analysis of driftless-gas proportional scintillation counters SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE xenon gaseous detectors; gas proportional scintillation counters; driftless; pulse analysis ID SOFT X-RAYS; DETECTORS AB A new method for pulse analysis of driftless-gas proportional scintillation counters (GPSCs) is presented. With this method the requirement for additional analog or digital signal time-analysis and pulse-amplitude correction currently used is eliminated. In contrast to conventional- and driftless-GPSCs that have always relied on long shaping-time constants (several mus), the use of very short linear amplifier shaping-time constants (similar to50 ns) enables pulse shapes to closely represent the scintillation light-pulse time-profile. Since the number of detected photons in the photosensor increases continuously with depth due to the increase in the solid angle subtended by the photosensor, a maximum is achieved when the primary electron cloud is closest to the anode. This maximum depends only on the number of primary electrons in that cloud, regardless of where the X-ray absorption took place, and is proportional to the X-ray energy. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Coimbra, Dept Fis, P-3004516 Coimbra, Portugal. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP dos Santos, JMF (reprint author), Univ Coimbra, Dept Fis, P-3004516 Coimbra, Portugal. RI veloso, joao/J-4478-2013; Covita, Daniel/J-5627-2013; dos Santos, Joaquim/B-3058-2015; OI Veloso, Joao/0000-0002-7107-7203; dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 11 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 247 EP 251 DI 10.1016/S0168-9002(03)01062-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700059 ER PT J AU Helmer, RG AF Helmer, RG TI Modern tools for precise gamma-ray spectrometry with Ge detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE gamma-ray spectrometry; gamma-ray energies; detector efficiencies; gamma-ray spectra ID MONTE-CARLO CALCULATIONS; HPGE DETECTOR; EFFICIENCY CALIBRATION; ENERGY CALIBRATION; CURVE AB Over the past few years, several data evaluations and method developments have improved the capability to do precise gamma-ray spectrometry and some of these are described here. For energy calibration, an evaluation of a large set of consistent gamma-ray energies, generally with uncertainties of less than 10 ppm, has been published. A program to produce high-quality, well-documented decay data is the Decay Data Evaluation Project (DDEP) which is an informal collaboration of evaluators from six countries with the goal of producing evaluations of the decay data for about 250 nuclides of interest in various applications. As an aid in more precise efficiency calibration, new measurements have improved the relative emission probabilities for the strong gamma rays from the decay of Co-56 and Ga-66 which extend up to 4.8 MeV. Also, new studies have demonstrated the use of Monte Carlo calculations along with measured data in the determination of efficiency curves at a precision approaching 0.1% over an extended energy range. A Catalogue of new gamma-ray spectra, the associated decay schemes, and the energies and emission probabilities is being made available on the Internet. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Idaho State Univ, Idaho Accelerator Ctr, Pocatello, ID 83209 USA. RP Helmer, RG (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 18 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 297 EP 305 DI 10.1016/S0168-9002(03)01073-8 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700070 ER PT J AU Popov, V AF Popov, V TI Design and study of photomultiplier pulse-shaping amplifier powered by the current flowing through a voltage divider SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE photomultipliers; amplifier; Cherenkov detectors AB A new version of Photomultiplier Tube (PMT) pulse amplifier, entirely powered by the current flowing through the base voltage divider, was designed and tested. This amplifier was designed for application in the JLAB G0 Experiment E00-006 as a part of high voltage base for XP2262 Photonis PMT. According to JLAB G0 experiment requirement, these PMT's operate with plastic scintillators at high counting rate (about MHz). Tests in JLAB experimental Hall C indicate that low energy gamma background cause up to 0.1 mA of PMT average anode current (without amplifier). At this radiation condition, PMT gain decreases by 50% within about I month of operation. The amplifier needs to reduce PMT anode current and to shape PMT anode pulse prior to sending it through a long cable line (more then 400 ft of RG-213 and RG-58 coax cables). Shaping of the PMT output pulse helps to reduce attenuation effect of the long cable line without significant reduction of timing accuracy. The results of this study of designed amplifier and PMT plus amplifier system are presented. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Thomas Jefferson Natl Accelerator Facil, Jefferson Lab, Newport News, VA 23606 USA. RP Popov, V (reprint author), Thomas Jefferson Natl Accelerator Facil, Jefferson Lab, Newport News, VA 23606 USA. NR 1 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 316 EP 319 DI 10.1016/S0168-9002(03)01076-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700073 ER PT J AU Smith, LE Aalseth, CE Hossbach, TW Miley, HS Perkins, RW Ellis, JE AF Smith, LE Aalseth, CE Hossbach, TW Miley, HS Perkins, RW Ellis, JE TI Development of portable multicoincidence radionuclide analysis systems SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE tadionuclides analysis; environmental sampling; nuclear forensics; coincidence systems ID GAMMA-RAY SPECTRA AB Multicoincidence radionuclide analysis systems consisting of light-charged-particle detectors operating in coincidence with photon spectrometers are being developed to improve the sensitivity of radionuclide analysis in field applications. Requiring charged-particle/photon coincidence provides active shielding from environmental photon sources, and mapping photon-photon events into a coincidence plane can remove photon spectroscopy interferences. List-mode data acquisition and flexible hardware design ensures that the most sensitive coincidence schemes. involving beta, atomic electron, gamma and X-ray emissions can be used for radionuclide quantification. System hardware design and preliminary measurement data are discussed. A centerpiece component of this project, the development of analysis, tools and data libraries required to perform automated multicoincidence analysis, is also described. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Smith, LE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 8 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 320 EP 323 DI 10.1016/S0168-9002(03)01077-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700074 ER PT J AU Nelson, MA Rooney, BD Dinwiddie, DR Brunson, GS AF Nelson, MA Rooney, BD Dinwiddie, DR Brunson, GS TI Analysis of digital timing methods with BaF2 scintillators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE digital signal timing; constant-fraction discrimination; pulse shape fitting; digital pulse timing AB Various digital methods were examined for determining the relative arrival,times of pulses from to 5.08 x 2.54 cm. BaF2 scintillators. In this study, pulses from the photomultiplier tubes were digitized by a 1 Gs/s analog-to-digital converter and post processed with multiple techniques. These techniques include: (1) leading edge discrimination, (2) moment-analysis, (3) constant-fraction discrimination, (4) digital constant-fraction discrimination, (5) triangular pulse shaping with a leading edge linear regression, and (6) pulse-shape fitting. Average timing resolutions of 456 +/- 8 ps were obtained with constant-fraction discrimination, which is slightly higher than the analog average resolution of 419 +/- 7 ps. This study explores the application of these digital techniques for pulse-timing applications and their potential advantages and limitations. Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Nelson, MA (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 20 Z9 21 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 324 EP 327 DI 10.1016/S0168-9002(03)01078-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700075 ER PT J AU O'Connor, P De Geronimo, G Kandasamy, A AF O'Connor, P De Geronimo, G Kandasamy, A TI Amplitude and time measurement ASIC with analog derandomization SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE peak detector; CMOS; time-to-amplitude converter; derandomizer ID SILICON STRIP DETECTORS; LOW-NOISE; READOUT; SYSTEM AB A versatile 32-channel ASIC has been developed for accurate 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 mum CMOS and tested. Amplitude accuracy of the peak detect and hold circuit is 0.2% (absolute) and 0.04% (nonlinearity) for signals within 0.3 V of either supply rail. Time walk is below 5 ns, droop rate is 25 0 mV/s, and power consumption is less than 2 mW/channel at pulse rates up to 500 kHz per channel. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP O'Connor, P (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 352 EP 357 DI 10.1016/S0168-9002(03)01095-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700081 ER PT J AU Khamzin, MK Valentine, JD AF Khamzin, MK Valentine, JD TI Discriminator amplitude walk correction in gamma-ray coincidence experiments using list-mode time-stamping data acquisition SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE timing walk; timing jitter; time spectroscopy; ESCSC; Compton scatter camera AB When pulse amplitude and time stamp are recorded in list-mode time-stamping data acquisition, it is possible to correct for the system amplitude walk, typically observed as the time pickoff dependence on pulse amplitude. In this study, a method of correcting for amplitude walk during post-acquisition analysis of such list mode data is developed and demonstrated. The method is demonstrated using a simple two-channel system and a photon source capable of producing coincidence events (Na-22). Two leading-edge discriminators, vulnerable to the amplitude walk, were used to produce the time pickoffs. The resulting corrected data chow an amplitude walk less than the detector timing resolution. The method developed can be. used in list-mode data acquisition systems such as medical imaging scanners or Compton scatter cameras. (C) 2003 Published by Elsevier Science B.V. C1 Georgia Inst Technol, Neely Nucl Res Ctr, Atlanta, GA 30332 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Khamzin, MK (reprint author), Georgia Inst Technol, Neely Nucl Res Ctr, 900 Altantic Dr, Atlanta, GA 30332 USA. NR 5 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 358 EP 361 DI 10.1016/S0168-9002(03)01096-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700082 ER PT J AU Moss, CE Frankle, CM Litvinenko, VN Weller, HR AF Moss, CE Frankle, CM Litvinenko, VN Weller, HR TI Recent results using the high intensity gamma-ray source facility SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE gamma-ray beam; free-electron laser; electron storage ring; photon cross-sections; photodisintegration; nuclear resonance fluorescence ID STORAGE-RING AB Ne describe the high intensity gamma-ray source, which produces nearly monoenergetic gamma-ray beams with energies ranging from 2 to 58 MeV, intensities of 10(5)-5 x 10(8) gamma/s, and 100% linear polarization. Upgrades of the facility are in progress to increase the energy range and intensity. To illustrate some of the present capabilities of the facility, we describe the measurement of total photon attenuation cross-sections to +/-0.5% in the energy range 3.451-14 MeV. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Duke Univ, FEL Lab, Durham, NC 27708 USA. TUNL, Durham, NC 27708 USA. RP Moss, CE (reprint author), Los Alamos Natl Lab, POB 1663,Mail Stop J562, Los Alamos, NM 87545 USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 374 EP 376 DI 10.1016/S0168-9002(03)01100-8 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700086 ER PT J AU Ahmad, I Moore, EF Greene, JP Porter, CE Felker, LK AF Ahmad, I Moore, EF Greene, JP Porter, CE Felker, LK TI Quantitative determination of Cf-252 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE radioactivity Cf-252; measured I-gamma of fission fragments ID NEUTRON-INDUCED FISSION AB Sealed Cf-252 sources in the microCurie to milliCurie range are routinely used in industry and research. At present, no reliable analytical method is available for precise determination of the activity. Very strong sources can be analyzed by neutron counting but the error is large. We propose to use gamma-ray spectroscopy for such analysis. In particular, high-energy gamma rays (above 1 MeV) of fission fragments in equilibrium with the source are very convenient because they have little absorption in materials surrounding the source. It is found that the 1435.8-keV gamma-ray of Cs-138 and the 1596.5-keV gamma-ray of La-140 are well isolated and sufficiently above the background under these peaks. We have measured the gamma/alpha ratio for the Cf-252 with an uncertainty of better than 5%. The experiment involved the preparation of several thin Cf-252 sources, alpha pulse height analysis, determination of alpha decay rate, and the measurement of gamma singles spectrum with a well-shielded germanium spectrometer. The measured ratio and the gamma-ray spectroscopy of unknown samples can provide the activity of Cf-252, in these samples. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. RP Ahmad, I (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 10 TC 1 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 389 EP 392 DI 10.1016/S0168-9002(03)01104-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700090 ER PT J AU Woodring, M Beddingfield, D Souza, D Entine, G Squillante, M Christian, J Kogan, A AF Woodring, M Beddingfield, D Souza, D Entine, G Squillante, M Christian, J Kogan, A TI Advanced multi-dimensional imaging of gamma-ray radiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE RadCam2000; IMAGE2000; radiation; imager; gamma ray; MURA; coded aperture; data cube AB The tracking of radiation contamination and distribution has become a high-priority US DOE task. To support DOE needs, Radiation Monitoring Devices Inc. has been actively carrying out research and development on a gamma-radiation imager, RadCam 2000(TM). The imager is based upon a position-sensitive PMT coupled to a scintillator near a MURA coded aperture. The modulated gamma flux detected by the PSPMT is mathematically decoded to produce images that are computer displayed in near real time. Additionally, we have developed a data-manipulation scheme which allows a multi-dimensional data array, comprised of x position, gamma position, and energy, to be used in the imaging process. In the imager software a gate can be set on a specific isotope energy to reveal where in the field of view the gated data lies or, conversely, a gate can be set on an area in the field of view to examine what isotopes are present in that area. This process is complicated by the FFT decoding process used with the coded aperture; however, we have achieved excellent performance and results are presented here. (C) 2003 Published by Elsevier Science B.V. C1 Radiat Monitoring Devices Inc, Instrument Res & Dev Grp, Watertown, MA 01824 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Daddenmark Software, Chugiak, AK 99567 USA. RP Woodring, M (reprint author), Radiat Monitoring Devices Inc, Instrument Res & Dev Grp, 44 Hunt St, Watertown, MA 01824 USA. NR 8 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 415 EP 419 DI 10.1016/S0168-9002(03)01111-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700097 ER PT J AU Ziock, KP Burks, MT Craig, W Fabris, L Hull, EL Madden, NW AF Ziock, KP Burks, MT Craig, W Fabris, L Hull, EL Madden, NW TI Real-time generation of images with pixel-by-pixel spectra for a coded aperture imager with high spectral resolution SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE germanium detector; strip detector; gamma-ray imaging; coded aperture; orthogonal strip; position sensing ID RAY; ARRAYS AB The capabilities of a coded aperture imager are significantly enhanced when a detector with excellent energy resolution is used. We are constructing such an imager with a 1.1 cm thick, crossed-strip, planar detector which has 3 8 strips of 2 mm pitch in each dimension followed by a large coaxial detector. Full value from this system is obtained only when the images are "fully deconvolved" meaning that the energy spectrum is available from each pixel in the image. The large number of energy bins associated with the spectral resolution of the detector, and the fixed pixel size, present significant computational challenges in generating an image in a timely manner at the conclusion of a data acquisition. The long computation times currently preclude the generation of intermediate images during the acquisition itself. We have solved this problem by building the images on-line as each event comes in using pre-imaged arrays of the system response. The generation of these arrays and the use of fractional mask-to-detector pixel sampling is discussed. (C) 2003 Published by Elsevier Science B.V. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Ziock, KP (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 10 TC 18 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 420 EP 424 DI 10.1016/S0168-9002(03)01112-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700098 ER PT J AU Micklich, BJ Smith, DL Massey, TN Fink, CL Ingram, D AF Micklich, BJ Smith, DL Massey, TN Fink, CL Ingram, D TI FIGARO: detecting nuclear materials using high-energy gamma-rays SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE nuclear materials detection; low-energy proton accelerator; gamma-rays; photofission AB The potential diversion of nuclear materials is a major international concern. Fissile (e.g., U, Pu) and other nuclear materials (e.g., D, Be) can be detected using 6-7 MeV gamma-rays produced in the F-19(p,alphagamma) O-16 reaction. These gamma-rays can induce, neutron emission via photoneutron and photofission processes in nuclear materials. However, they are not energetic enough to generate significant numbers of neutrons from common benign materials. Neutrons are counted using an array of BF3 tubes in a polyethylene moderator. A strong increase in neutron count rates is seen when irradiating depleted uranium, Be, D2O, and Li-6, with little or no increase for other materials (e.g., H2O, SS, Cu, Al, C, Li-7). Experiments using both photon and neutron shielding show that the technique is resistant to countermeasures. We have reduced the neutron background from proton beam reactions (thus increasing the system's sensitivity) and have tested a high-current gas cell which should be capable of operating at proton beam currents of up to 100 muA. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. Ohio Univ, Dept Phys & Astron, Edwards Accelerator Lab, Athens, OH 45701 USA. RP Micklich, BJ (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 466 EP 469 DI 10.1016/S0168-9002(03)01122-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700108 ER PT J AU Beddingfield, DH Beyerle, A Russo, PA Ianakiev, K Vo, DT Dmitrenko, V AF Beddingfield, DH Beyerle, A Russo, PA Ianakiev, K Vo, DT Dmitrenko, V TI High-pressure xenon ion chambers for gamma-ray spectroscopy in nuclear safeguards SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE xenon; spectroscopy; safeguards AB There has been a long-standing need for a room-temperature gamma-ray detector system with high efficiency and adequate resolution for nuclear safeguards applications. For nuclear safeguards, measurements must resolve the uranium complex at 186 keV and the plutonium complex at 414 keV. The kneed for adequate room-temperature resolution has been met by CdZnTe detectors, but these small detectors cannot produce the efficiency needed for broad application in nuclear safeguards. The high-pressure xenon (HPXe) detector offers resolution, efficiency, intrinsic radiation resistance and temperature stability, making this detector type a viable candidate for broad application in nuclear safeguards. We will examine the current status HPXe detector systems, contrast HPXe with other detector types for nuclear safeguards applications, and discuss our efforts to improve the HPXe detector operating characteristics. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Mirmar Sensor LLC, Santa Barbara, CA USA. Moscow Engn Phys State Inst, Moscow 115409, Russia. RP Beddingfield, DH (reprint author), Los Alamos Natl Lab, MS E540,NIS-5,POB 1663, Los Alamos, NM 87545 USA. NR 2 TC 8 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 JUN 1 PY 2003 VL 505 IS 1-2 BP 474 EP 477 DI 10.1016/S0168-9002(03)01124-0 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700110 ER PT J AU Bell, ZW Hickerson, TW Gaby, JE Williams, JA AF Bell, ZW Hickerson, TW Gaby, JE Williams, JA TI Analysis of a radiation attribute from uranium in storage SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE uranium; solid-state detector; silicon P-I-N diode; analysis; statistics AB Storage of radioactive nuclear material necessitates the measurement of gamma and X-ray count rate to discourage tampering. However,. in long-term, unattended storage scenarios, it is vital that the analysis of this count rate account for perturbations in the count rate caused by drifting equipment response, and changes in natural (radon levels, for example) or man-made background. In this paper, we report the long-term behavior of 420 silicon P-I-N diode's used as radiation detectors. Data were obtained over the course of 16-20 months at both 1-h and 1-min intervals, and, in addition to perfectly stable count rates, effects attributable to equipment failure, long-term gain drift, short-term gain drift, and software failures were observed. The results of statistical analyses of the time series will be given as well as a description of an event classification algorithm. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Y 12 Natl Secur Complex, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bell, ZW (reprint author), Y 12 Natl Secur Complex, Bear Creek Rd, Oak Ridge, TN 37831 USA. OI Bell, Zane/0000-0003-1115-8674 NR 1 TC 0 Z9 0 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 JUN 1 PY 2003 VL 505 IS 1-2 BP 494 EP 497 DI 10.1016/S0168-9002(03)01131-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700115 ER PT J AU Cooper, JC Koltick, DS Mihalczo, JT Neal, JS AF Cooper, JC Koltick, DS Mihalczo, JT Neal, JS TI Evaluation of ZnO(Ga) coatings as alpha particle transducers within a neutron generator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Symposium on Radiation Measurements and Applications CY MAY 21-23, 2002 CL ANN ARBOR, MICHIGAN DE alpha detection; zinc oxide; neutron activation AB Neutrons generated by the deuterium-tritium reaction (D-2 + T-3 --> n + alpha) are correlated to the alpha particle by energy and momentum conservation to lie along trajectories 180degrees with respect to one another. An associated particle neutron generator uses this spatial correlation to infer the neutron trajectory by detecting the alpha particle. This technique can be used to suppress backgrounds and in building three-dimensional images using the return excitation gamma-ray energy due to the neutron interactions. The critical-performance component of the system is the alpha detection element, which is embedded within the neutron generator accelerator head. This element must be highly efficient, capable of nanosecond timing, and robust under the temperature changes encountered during manufacture. ZnO(Ga) scintillator coatings of differing thicknesses, with and without Ni overcoatings, were evaluated for this purpose, when excited by alpha particles between 3.2 and 5.4MeV. Average light output of up to 61 photoelectrons per event was measured. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Purdue Univ, Dept Phys, Ctr Sensing Sci & Technol, W Lafayette, IN 47907 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Cooper, JC (reprint author), Purdue Univ, Dept Phys, Ctr Sensing Sci & Technol, 1396 Phys Bldg, W Lafayette, IN 47907 USA. RI Neal, John/R-8203-2016 OI Neal, John/0000-0001-8337-5235 NR 7 TC 25 Z9 25 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2003 VL 505 IS 1-2 BP 498 EP 501 DI 10.1016/S0168-9002(03)01132-X PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 693JJ UT WOS:000183713700116 ER PT J AU Elvira, VD AF Elvira, VD CA DO Collaboration TI Jet measurements at DO using a k(T) algorithm SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 9th High-Energy Physics International Conference on Quantum ChromoDynamics CY JUL 02-09, 2002 CL MONTPELLIER, FRANCE SP Montpellier Reg, Montpellier Town & Dist, Univ Montpellier II ID DEEP-INELASTIC-SCATTERING; EVENT-SHAPE VARIABLES; HADRON-COLLISIONS; PARTON DISTRIBUTIONS; GLOBAL ANALYSIS; GLUON JETS; ALPHA-S; DECAYS; Z0; QCD AB DO has implemented and calibrated a k(perpendicular to) jet algorithm for the first time in a p (p) over bar collider. We present two results based on 1992-1996 data which were recently published: the subjet multiplicity in quark and gluon jets and the central inclusive jet cross section. The measured ratio between subjet multiplicities in gluon and quark jets is consistent with theoretical predictions and previous experimental values. NLO pQCD predictions of the k(perpendicular to) inclusive jet cross section agree with the DO measurement, although marginally in the low p(T) range. We also 3 present a preliminary measurement of thrust cross sections, which indicates the need to include higher than alpha(s)(3) terms and resumation in the theoretical calculations. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM daniel@fnal.gov NR 41 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 121 BP 21 EP 28 DI 10.1016/S0920-5632(03)01805-X PG 8 WC Physics, Particles & Fields SC Physics GA 699DD UT WOS:000184039900005 ER PT J AU Albino, S Klasen, M Soldner-Rembold, S AF Albino, S Klasen, M Soldner-Rembold, S TI Strong coupling constant from the photon structure function SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 9th High-Energy Physics International Conference on Quantum ChromoDynamics CY JUL 02-09, 2002 CL MONTPELLIER, FRANCE SP Montpellier Reg, Montpellier Town & Dist, Univ Montpellier II ID STRUCTURE-FUNCTION F-2(GAMMA); PARTON DISTRIBUTIONS; Q(2) EVOLUTION; LEP; Q2; GEV2 C1 Univ Hamburg, Inst Theoret Phys 2, D-22761 Hamburg, Germany. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Univ Hamburg, Inst Theoret Phys 2, Luruper Chaussee 149, D-22761 Hamburg, Germany. EM simon@mail.desy.de NR 28 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 121 BP 73 EP 73 DI 10.1016/S0920-5632(03)01816-4 PG 1 WC Physics, Particles & Fields SC Physics GA 699DD UT WOS:000184039900016 ER PT J AU Black, D Harada, M Schechter, J AF Black, D Harada, M Schechter, J TI Vector-meson-dominance model for radiative decays involving light scalar mesons SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 9th High-Energy Physics International Conference on Quantum ChromoDynamics CY JUL 02-09, 2002 CL MONTPELLIER, FRANCE SP Montpellier Reg, Montpellier Town & Dist, Univ Montpellier II ID Q(Q)OVER-BAR NONET; KLOE DETECTOR; PHI->ETA-PI(0)GAMMA; HADRONS; STATES AB We present a vector dominance model to describe radiative decays involving the light scalar mesons. Assuming that the light scalar mesons form a nonet this model gives relations among various decay amplitudes of the form S --> gammagamma, V --> Sgamma and S --> Vgamma, where S and V denote scalar and vector mesons. By comparing with experimental radiative decay rates, including those recently measured for phi --> PP'gamma, we obtain a fairly large number of predictions. We discuss briefly ongoing extensions of the present work in an attempt to describe the radiative phi decay measurements in detail. C1 Theory Grp, Jefferson Lab, Newport News, VA 23606 USA. Seoul Natl Univ, Sch Phys, Seoul 151742, South Korea. Syracuse Univ, Dept Phys, Syracuse, NY 13244 USA. RP Black, D (reprint author), Theory Grp, Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 121 BP 95 EP 98 DI 10.1016/S0920-5632(03)01820-6 PG 4 WC Physics, Particles & Fields SC Physics GA 699DD UT WOS:000184039900020 ER PT J AU Gritsan, AV AF Gritsan, AV CA BABAR Collaboration TI Measurement of sin(2 alpha) at BABAR SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela ID CP-VIOLATION; MESON SYSTEM; B-DECAYS; ASYMMETRIES AB We present updated measurements of branching fractions and CP-violating asymmetries for neutral B meson decays to two-body final states of charged pions and kaons. The results are obtained from a data sample of about 60 million Y(4S) --> B (B) over bar decays collected between 1999 and 2001 by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The sample contains 124(-15)(+16) pipi, 403 +/- 24 Kpi, and 0.6(-7.4)(+8.0) KK candidates, from which we measure the following quantities: B(B-o --> pi(+)pi(-)) = (5.4 +/- 0.7 +/- 0.4) x 10(-6), B(B-o --> K(+)pi(-)) = (17.8 +/- 1.1 +/- 0.8) x 10(-6), B(B-o --> K+K-) < 1.1 x 10(-6) (90% C.L.), A(Kpi) = -0.05 +/- 0.06 +/- 0.01 [-0.14, +0.05], S-pipi = -0.01 +/- 0.37 +/- 0.07 [-0.66, +0.62], C-pipi = -0.02 +/- 0.29 +/- 0.07 [-0.54, +0.48], where the errors are statistical and systematic; respectively, and the asymmetry limits correspond to the 90% confidence level. These results are preliminary. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Gritsan, AV (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 91 EP 96 DI 10.1016/S0920-5632(03)01886-3 PG 6 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000013 ER PT J AU Baranovski, A Garzoglio, G Lueking, L Terekhov, DSI Walker, R AF Baranovski, A Garzoglio, G Lueking, L Terekhov, DSI Walker, R TI SAM-GRID: A system utilizing grid middleware and SAM to enable full function grid computing SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela AB We present a grid system, which is in development, employing an architecture comprising the primary functional components of job handling, data handling, and monitoring and information services. Each component is built using existing Grid middleware. The Job handling utilizes Condor Match Making Services to broker job submissions, Condor-G to schedule, and GRAM to submit and execute jobs on remote compute resources. The information services provide strategic information of the system including a file replica catalogue, compute availability; and network data-throughput rate predictions, which are made available to the other components. Data handling services are provided by SAM, the data management system built for the Dzero experiment at Fermilab, to optimize data delivery, and cache and replicate data as needed at the processing nodes. The SAM-Grid system is being built to provide experiments in progress at Fermilab the ability to utilize worldwide computing resources to process enormous quantities of data for complex physics analyses. C1 Fermilab Natl Accelerator Lab, Batavia, IL USA. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. RP Baranovski, A (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL USA. NR 10 TC 2 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 119 EP 125 DI 10.1016/S0920-5632(03)01891-7 PG 7 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000018 ER PT J AU Butler, JN AF Butler, JN CA BTeV Collaboration TI Distributed and/or grid-oriented approach to BTeV data analysis SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela AB The BTeV collaboration will record approximately 2 petabytes of raw data per year. It plans to analyze this data using the distributed resources of the collaboration as well as dedicated resources, primarily residing in the very large BTeV trigger farm, and resources accessible through the developing world-wide data grid. The data analysis system is being designed from the very start with this approach in mind. In particular, we plan a fully disk-based data storage system with multiple copies of the data distributed across the collaboration to provide redundancy and to optimize access. We will also position ourself to take maximum advantage of shared systems, as well as dedicated systems, at our collaborating institutions. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Butler, JN (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 131 EP 135 DI 10.1016/S0920-5632(03)01893-0 PG 5 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000020 ER PT J AU Giagu, S AF Giagu, S CA CDF Collaboration TI The CDFII Time-of-Flight detector and impact on beauty flavor tagging SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela ID P(P)OVER-BAR COLLISIONS AB The new CDFII detector incorporates a Time-of-Flight detector (TOF), employing plastic scintillator bars and fine-mesh photomultipliers. Since August 2001 the TOF system has been fully instrumented and integrated into the CDFII data acquisition system. With a design goal of 100 ps resolution the TOF system will provide at least two standard deviations separation between K+/- and pi(+/-) for momenta p < 1.6 GeV/c, complementing low momentum particle identification by means of the specific ionization energy loss measured in the drift chamber. We describe the design of the TOF detector and discuss the current status of its calibration and initial performances. Finally we review the expected impact of the TOF detector in the flavor tagging of neutral B-s(0) meson. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Roma La Sapienza, Ist Nazl Fis Nucl, Rome, Italy. RP Giagu, S (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RI Kim, Soo-Bong/B-7061-2014 NR 10 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 219 EP 224 DI 10.1016/S0920-5632(03)01905-4 PG 6 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000032 ER PT J AU Kutschke, RK AF Kutschke, RK CA BTeV Collaboration TI BTeV: Lepton, hadron and photon identification SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela AB The BTeV detector contains three particle ID devices: a RICH detector, an Electromagnetic Calorimeter and a Muon Detector. These are used to distinguish among the five types of charged tracks (e, mu, pi, K, p), to reconstruct single photons, and to reconstruct mesons such as pi(0) and eta((1)) which decay into photons. This article will outline the design of these devices, with particular attention to recent developments, and will present some benchmark numbers for the expected performance of these devices. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kutschke, RK (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. OI Kutschke, Robert/0000-0001-9315-2879 NR 2 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 225 EP 229 DI 10.1016/S0920-5632(03)01906-6 PG 5 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000033 ER PT J AU Kutschke, RK AF Kutschke, RK CA BTeV Collaboration TI BTeV: Status, overview and prospects SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela AB The BTeV Collaboration is designing a detector to perform a broad program of studies in flavor physics in the beauty and charm systems: CP violation, flavor mixing and searches for rare and forbidden decays. The program will be sensitive to many signatures for physics beyond the Standard Model. The BTeV detector will be located at the CZero interaction region of the Tevatron p-(p) over bar collider at Fermilab. This report will present the status of the program, review the detector design with emphasis on new developments, survey the projected physics reach, and conclude with expectations for the future. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kutschke, RK (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. OI Kutschke, Robert/0000-0001-9315-2879 NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 311 EP 315 DI 10.1016/S0920-5632(03)01921-2 PG 5 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000048 ER PT J AU Butler, JN AF Butler, JN TI B physics, BTeV, and all that SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 8th International Conference on B-Physics at Hadron Machines CY JUN 17-21, 2002 CL SANTIAGO COMPOSTE, SPAIN SP Spanish Minist Sci & Technol, Univ Santiago Compostela ID KOBAYASHI-MASKAWA MATRIX; CP-VIOLATION; PARAMETRIZATION; ASYMMETRY AB The status of "flavor physics" in our pursuit of knowledge in elementary particle physics is discussed. Then, the BTeV experiment, planned for the Fermilab Tevatron collider, is described briefly and its physics reach is discussed. Comparisons are made to the current B physics experiments at e(+)e(-) facilities and to the LHCb experiment, planned for the Large Hadron Collider at CERN. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Butler, JN (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 17 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2003 VL 120 BP 325 EP 331 DI 10.1016/S0920-5632(03)01923-6 PG 7 WC Physics, Particles & Fields SC Physics GA 688CU UT WOS:000183416000050 ER PT J AU Shinohara, N Kohno, N Nakahara, Y Tsujimoto, K Sakurai, T Mukaiyama, T Raman, S AF Shinohara, N Kohno, N Nakahara, Y Tsujimoto, K Sakurai, T Mukaiyama, T Raman, S TI Validation of minor actinide cross sections by studying samples irradiated for 492 days at the Dounreay prototype fast reactor - I: Radiochemical analysis SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Actinide samples irradiated in the Dounreay Prototype Fast Reactor for 492 effective full-power days were analyzed at Japan Atomic Energy Research Institute by radiochemical methods to measure the isotopic compositions of the fission products (molybdenum, zirconium, and neodymium isotopes) and of the actinides (uranium, neptunium, plutonium, americium, curium, and californium isotopes). In this first of two companion papers, procedures used for chemical analyses and the analyzed data are presented. There is good agreement between the current results and previous results obtained at Oak Ridge National Laboratory. Therefore, these analytical results could serve as a benchmark for future calculations and validation of nuclear data libraries. Such a validation is attempted in the companion paper. C1 Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Shinohara, N (reprint author), Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. NR 13 TC 5 Z9 5 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 2003 VL 144 IS 2 BP 115 EP 128 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 680PC UT WOS:000182985700001 ER PT J AU Tsujimoto, K Kohno, N Shinohara, N Sakurai, T Nakahara, Y Mukaiyama, T AF Tsujimoto, K Kohno, N Shinohara, N Sakurai, T Nakahara, Y Mukaiyama, T TI Validation of minor actinide cross sections by studying samples irradiated for 492 days at the Dounreay prototype fast reactor - II: Burnup calculations SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB To evaluate neutron cross-section data of minor actinides (MAs), separated actinide samples and dosimetry samples were irradiated at the Dounreay Prototype Fast Reactor for 492 effective full-power days. Irradiated samples were analyzed both at-Oak Ridge National Laboratory and at Japan Atomic Energy Research Institute (JAERI). This independent duplication has resulted in the generation of reliable radiochemical analysis data. Based on the burnup calculations of major-actinide (U-235 and: Pu-239) and dosimetry samples,- the neutron flux distribution and the flux level were adjusted at the locations where MA samples were irradiated. The burnup calculations were carried out for MAs using the determined flux distribution and flux level. The calculated results were compared with the experimental data. A brief description of sample preparation and irradiation and a detailed discussion of radiochemical analysis at JAERI are given in a companion paper. The current paper discusses the burnup calculations and the validation of MA cross-section data in evaluated nuclear data libraries. C1 Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tsujimoto, K (reprint author), Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. NR 21 TC 8 Z9 8 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 2003 VL 144 IS 2 BP 129 EP 141 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 680PC UT WOS:000182985700002 ER PT J AU Chadwick, MB Young, PG MacFarlane, RE White, MC Little, RC AF Chadwick, MB Young, PG MacFarlane, RE White, MC Little, RC TI Photonuclear physics in radiation transport - I: Cross sections and spectra SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID CONTINUUM ANGULAR-DISTRIBUTIONS; NUCLEAR-REACTIONS; LEVEL DENSITIES; SYSTEMATICS; PHOTOABSORPTION; SILICON; ISOSPIN; REGION; MODEL; PB AB This paper describes model calculations and nuclear data evaluations of photonuclear reactions on isotopes of C, O, Al, Si, Ca, Fe, Cu, Ta, W and Pb for incident photon energies up to 150 MeV The calculations, using the GNASH code, include giant-dipole, resonance and quasi-deuteron models for photoabsorption. The emission of secondary particles and gamma rays is computed using preequilibrium theory, together with an open-ended sequence of compound nucleus decays using the Hauser-Feshbach theory. The accuracy of the calculated and evaluated cross sections is assessed through extensive comparisons with measured cross sections, average neutron multiplicities, and energy-dependent emission spectra. The evaluated nuclear data files (ENDF) facilitate radiation transport studies of the importance of photonuclear reactions in a number of technologies including photoneutrons produced in electron/photon accelerators, shielding studies, and nondestructive detection of nuclear materials. A companion paper describes developments in the MCNP and MCNPX codes to utilize these data in transport simulations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chadwick, MB (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 62 TC 12 Z9 12 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 2003 VL 144 IS 2 BP 157 EP 173 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 680PC UT WOS:000182985700004 ER PT J AU White, MC Little, RC Chadwick, MB Young, PG MacFarlane, RE AF White, MC Little, RC Chadwick, MB Young, PG MacFarlane, RE TI Photonuclear physics in radiation transport - II: Implementation SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB This is the second of two companion papers. Thefirst paper describes model calculations and nuclear data evaluations of photonuclear reactions on isotopes of C, O, Al, Si, Ca, Fe, Cu, Ta, W, and Pb for incident photon energies up to 150 MeV This paper describes the steps taken to process these files into transport libraries and to update the Monte Carlo N-Particle (MCNP) and M-CNPX radiation transport codes to use tabular photonuclear reaction data. The evaluated photonuclear data files are created in the standard evaluated nuclear data file (ENDF) format. These files must be processed by the NJOY data processing system into A Compact ENDF (ACE) files suitable for radiation transport calculations. MCNP and MCNPX have been modified to use these new data in a self-consistent and fully integrated manner. Verification problems were used at each step along the path to check the integrity of the methodology. The resulting methodology and tools provide a comprehensive system for using photonuclear data in radiation transport calculations. Also described are initial validation simulations used to benchmark several of the photonuclear transport tables. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP White, MC (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 28 TC 9 Z9 9 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 2003 VL 144 IS 2 BP 174 EP 189 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 680PC UT WOS:000182985700005 ER PT J AU Fessenden, JE Ehleringer, JR AF Fessenden, JE Ehleringer, JR TI Temporal variation in delta C-13 of ecosystem respiration in the Pacific Northwest: links to moisture stress SO OECOLOGIA LA English DT Article DE carbon isotopes; CO2; discrimination; ecosystem respiration; soil respiration ID CARBON-ISOTOPE DISCRIMINATION; ATMOSPHERIC CO2; ANTHROPOGENIC CO2; DARK RESPIRATION; RESPIRED CO2; FOREST; C-13; PHOTOSYNTHESIS; RATIO; DIOXIDE AB We measured seasonal and interannual variations in delta(13)C values within the carbon reservoirs (leaves and soil) and CO2 fluxes (soil and ecosystem respired CO2) of an old growth coniferous forest in the Pacific Northwest USA with relation to local meteorological conditions. There were significant intra-annual and interannual differences in the carbon isotope ratios of CO2 respired at both the ecosystem (delta(13)C(R)) and the soil levels (delta(13)C(R-soil)), but only limited variations in the carbon isotope ratios of carbon stocks. The delta(13)C(R) values varied by as much as 4.4parts per thousand over a growing season, while delta(13)C(R-soil) values changed as much as 6.2parts per thousand. The delta(13)C of soil organic carbon (delta(13)C(SOC)) and needle organic carbon (delta(13)C(P)) exhibited little or no significant changes over the course of this study. Carbon isotope discrimination within leaves (Delta(p)) showed systematic decreases with increased canopy height, but remained fairly constant throughout the year (Delta(p)=17.9parts per thousand-19.2parts per thousand at the top of the canopy, Delta(p)=19.6parts per thousand-20.9parts per thousand at mid-canopy, Delta(p)=23.3parts per thousand-25.1parts per thousand at the canopy base). The temporal variation in the delta(13)C of soil and ecosystem respired CO2 was correlated (r=0.93, P<0.001) with soil moisture levels, with dry summer months having the most C-13-enriched values. The dynamic seasonal changes in δC-13 of respired CO2 are hypothesized to be the result of fast cycling of recently fixed carbon back to the atmosphere. One scaling consequence of the seasonal and interannual variations in δC-13(R) is that inversion-based carbon-cycle models dependent on observed atmospheric CO2 concentration and isotope values may be improved by incorporating dynamic δC-13(R) values to interpret regional carbon sink strength. C1 Los Alamos Natl Lab, Hydrol Geol & Geochem Div, Los Alamos, NM 87545 USA. Univ Utah, Dept Biol, SIRFER, Salt Lake City, UT 84112 USA. RP Fessenden, JE (reprint author), Los Alamos Natl Lab, Hydrol Geol & Geochem Div, EES 6,MS D460, Los Alamos, NM 87545 USA. NR 47 TC 63 Z9 65 U1 3 U2 12 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD JUN PY 2003 VL 136 IS 1 BP 129 EP 136 DI 10.1007/s00442-003-1260-1 PG 8 WC Ecology SC Environmental Sciences & Ecology GA 692AK UT WOS:000183638000015 PM 12750989 ER PT J AU Pack, MV Armstrong, DJ Smith, AV Amiet, ME AF Pack, MV Armstrong, DJ Smith, AV Amiet, ME TI Second harmonic generation with focused beams in a pair of walkoff-compensating crystals SO OPTICS COMMUNICATIONS LA English DT Article DE nonlinear optics; second harmonic generation; walkoff compensation ID SINGLE AB We develop the heuristic theory of second harmonic generation with focused beams in walkoff-compensating crystals,and compare it with experiments, demonstrating excellent agreement. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Dept 1118, Albuquerque, NM 87185 USA. Duke Univ, Dept Phys, Durham, NC 27708 USA. RP Pack, MV (reprint author), Sandia Natl Labs, Dept 1118, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 3 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JUN 1 PY 2003 VL 221 IS 1-3 BP 211 EP 221 DI 10.1016/S0030-4018(03)01469-X PG 11 WC Optics SC Optics GA 688XW UT WOS:000183463400024 ER PT J AU Koshelev, IK Paulikas, AP Uran, S Beno, MB Jennings, G Linton, J Veal, BW AF Koshelev, IK Paulikas, AP Uran, S Beno, MB Jennings, G Linton, J Veal, BW TI Influence of a reactive element on the growth of a thermally grown chromia scale: A grazing emission X-ray fluorescence study SO OXIDATION OF METALS LA English DT Article DE grazing-emission X-ray fluorescence; reactive element effect; chromia scale ID OXIDE SCALES; OXIDATION; ALLOYS; CR; MECHANISM; ADDITIONS; ADHESION; CR2O3; FILMS AB The oxidation of 55Fe-25Cr-20Ni (wt.%) alloys, with and without added reactive element (RE) Y, were studied using grazing-emission X-ray fluorescence (GEXRF). Samples were studied after isothermal treatments at 750degreesC in O-2 and after cyclic-oxidation treatments. In early-stage oxidation, a Ni-rich scale is formed. The distribution of this early-stage Ni deposit is studied as the scale evolves. The Ni deposit, serving as a marker, remains on the outer scale surface in Y-containing alloys, but is not detectable in scales on Y-free alloys. The results indicate that new chromia scale growth occurs at the outer surface in Y-free alloys but, for Y-containing alloys, new growth occurs away from the outer surface. Thus, a shift in the growth mode is apparently observed at 750degreesC, consistent with higher-temperature observations. However, unlike the high-temperature measurements, scale-growth rates are not significantly affected by the RE. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Veal, BW (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 21 TC 2 Z9 2 U1 1 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD JUN PY 2003 VL 59 IS 5-6 BP 469 EP 481 DI 10.1023/A:1023615121997 PG 13 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 673XT UT WOS:000182606800002 ER PT J AU Hou, PY Moskito, J AF Hou, PY Moskito, J TI Sulfur segregation to Al2O3-FeAl interfaces studied by field emission-Auger electron spectroscopy SO OXIDATION OF METALS LA English DT Article DE Auger electron microscopy; iron alloys; surfaces and interfaces; oxidation; segregation ID HIGH-TEMPERATURE OXIDATION; OXIDE SCALE ADHERENCE; AL2O3/ALLOY INTERFACES; INTERGRANULAR FRACTURE; IMPURITY SEGREGATION; GRAIN-BOUNDARIES; REACTIVE ELEMENT; METAL INTERFACE; ADHESION; BEHAVIOR AB Using a 30-nm field-emission Auger spectroscopy probe, the segregation of sulfur to a growing oxide-metal interface was studied. The interfaces were formed by the oxidation of a Fe-40at.% Al alloy at 1000degreesC for various times. Both the oxide and the alloy sides of the interface were examined after spalling the surface Al2O3 layer in ultra-high vacuum. Results were compared with similar studies performed using conventional AES and related to scale development and the interface microstructure. Sulfur started to segregate to the interface only after a complete layer of alpha-Al2O3 developed there, its concentration then increased slowly with further oxidation until reaching a level close to half a monolayer. Higher amounts were observed on interfacial-void surfaces, where Al and S cosegregated. The study showed that sulfur segregation to oxide-alloy interfaces depended on the type of interface, indicating possible relationships between segregation energies and interface microstructure. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Charles Evans & Associates, Sunnyvale, CA 94086 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 37 TC 20 Z9 20 U1 2 U2 5 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X EI 1573-4889 J9 OXID MET JI Oxid. Met. PD JUN PY 2003 VL 59 IS 5-6 BP 559 EP 574 DI 10.1023/A:1023627424723 PG 16 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 673XT UT WOS:000182606800008 ER PT J AU Yamakov, V Wolf, D Phillpot, SR Mukherjee, AK Gleiter, H AF Yamakov, V Wolf, D Phillpot, SR Mukherjee, AK Gleiter, H TI Deformation mechanism crossover and mechanical behaviour in nanocrystalline materials SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; BOUNDARY DIFFUSION CREEP; SIZE; ALUMINUM; METALS; COPPER AB We use molecular dynamics simulations to elucidate the transition with decreasing grain size from a dislocation- to a grain-boundary-based deformation mechanism in nanocrystalline fee metals. Our simulations reveal that this crossover is accompanied by a pronounced transition in the mechanical behaviour of the material; namely, at the grain size where the crossover occurs (the 'strongest size'), the strain rate under tensile elongation goes through a minimum. This simultaneous transition in both the deformation mechanism and the corresponding mechanical behaviour offers an explanation for the experimentally observed crossover in the yield strength of nanocrystalline materials, from Hall-Petch hardening to 'inverse Hall-Petch' softening. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Calif Davis, Div Mat Sci & Engn, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Forschungszentrum Karlsruhe, Inst Nanotechnol, D-76021 Karlsruhe, Germany. RP Yamakov, V (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA. EM wolf@anl.gov RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 28 TC 114 Z9 116 U1 8 U2 40 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD JUN PY 2003 VL 83 IS 6 BP 385 EP 393 DI 10.1080/09500830031000120891 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 706KK UT WOS:000184452700005 ER PT J AU Anderson, NE Straszheim, WE Bud'ko, SL Canfield, PC Finnemore, DK Suplinskas, RJ AF Anderson, NE Straszheim, WE Bud'ko, SL Canfield, PC Finnemore, DK Suplinskas, RJ TI Titanium additions to MgB2 conductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE MgB2 conductors; Ti-doping; CVD method ID CRITICAL-CURRENT DENSITY; SUPERCONDUCTIVITY; WIRES AB A series of doping experiments are reported for MgB2 conductors that have been synthesized using doped boron fibers prepared by chemical vapor deposition (CVD) methods. Undoped MgB2 samples prepared from CVD prepared fibers consistently give critical current densities, J(c), in the range of 500,000 A/cm(2) in low field at 5 K. These values fall by a factor of about 100 as the magnetic field increases to 3 T. For heavily Ti-doped boron fibers where the B/Ti ratio is comparable to 1, there is a substantial suppression of both T-c, superconducting volume fraction, and J(c) values. If, however, a sample with a few percent Ti in B is deposited on a carbon substrate and reacted at 1100 degreesC, then T-c is suppressed only a couple of degrees and critical current densities are found to be J(c) similar to 2-5 x 10(6) A/cm(2) for superconducting layers ranging from 4 to 10 mum thick. These materials show J(c) values over 10,000 A/cm(2) at 25 K and 1.3 T. (C) 2003 Elsevier Science B.V. All rights reserved. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Specialty Mat Inc, Lowell, MA 01851 USA. RP Finnemore, DK (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 8 TC 19 Z9 19 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN 1 PY 2003 VL 390 IS 1 BP 11 EP 15 DI 10.1016/S0921-4534(03)00863-3 PG 5 WC Physics, Applied SC Physics GA 684DX UT WOS:000183191100003 ER PT J AU Markos, P Soukoulis, CM AF Markos, P Soukoulis, CM TI Structures with negative index of refraction SO PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Wilhelm and Else Heraeus Summer School on Photonic Crystals CY JUL 15-25, 2002 CL WITTENBERG, GERMANY ID LEFT-HANDED MATERIALS; PHOTONIC BAND-GAP; LOW-FREQUENCY PLASMONS; EXPERIMENTAL-VERIFICATION; MICROWAVE TRANSMISSION; ELECTROMAGNETIC-WAVES; FREE-SPACE; METAMATERIALS; PERMITTIVITY; PERMEABILITY AB We review recent progress in the investigation of man made composites which exhibit negative refraction of the electromagnetic waves. Results for both left-handed materials (LHM) and photonic crystals are presented. Experiments on LHM are mostly done in the microwave regime, while on photonic crystals can be performed in the optical or the far-infrared regime. C1 Slovak Acad Sci, Inst Phys, Dept Complex Phys Syst, Bratislava 84511, Slovakia. Res Ctr Crete, Iraklion 71110, Crete, Greece. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Slovak Acad Sci, Inst Phys, Dept Complex Phys Syst, Dubravska Cesta 9, Bratislava 84511, Slovakia. EM soukoulis@ameslab.gov RI Soukoulis, Costas/A-5295-2008 NR 59 TC 6 Z9 6 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 1862-6300 EI 1862-6319 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Mat. PD JUN PY 2003 VL 197 IS 3 BP 595 EP 604 DI 10.1002/pssa.200303112 PG 10 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 695TM UT WOS:000183846500004 ER PT J AU Arbo, DG Reinhold, CO Burgdorfer, J Pattanayak, AK Stokely, CL Zhao, W Lancaster, JC Dunning, FB AF Arbo, DG Reinhold, CO Burgdorfer, J Pattanayak, AK Stokely, CL Zhao, W Lancaster, JC Dunning, FB TI Pulse-induced focusing of Rydberg wave packets SO PHYSICAL REVIEW A LA English DT Article ID HALF-CYCLE PULSES; ATOM; IONIZATION; MECHANICS; DYNAMICS; CHAOS AB We demonstrate that strong transient phase-space localization can be achieved by the application of a single impulsive "kick" in the form of a short (600 ps) unidirectional electric-field pulse to a strongly polarized, quasi-one-dimensional Rydberg atom. The underlying classical dynamics is analyzed and it is shown that phase-space localization results from a focusing effect analogous to rainbow scattering. Moreover, it is shown that the essential features of the classical analysis remain valid in a quantum-mechanical treatment of the system in terms of its phase-space Husimi distribution. The degree of phase-space localization is characterized by the coarse-grained Renyi entropy. Transient phase-space localization is demonstrated experimentally using extreme redshifted m=0 potassium Stark states in the n=351 manifold and a short probe pulse. The experimental data are in good agreement with theoretical predictions. The localized state provides an excellent starting point for further control and manipulation of the electron wave packet. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Vienna Univ Technol, Inst Theoret Phys, A-1040 Vienna, Austria. Carleton Coll, Dept Phys & Astron, Northfield, MN 55057 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. RP Arbo, DG (reprint author), Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. NR 30 TC 46 Z9 46 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2003 VL 67 IS 6 AR 063401 DI 10.1103/PhysRevA.67.063401 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 696YM UT WOS:000183915200089 ER PT J AU Fortunato, EM Viola, L Pravia, MA Knill, E Laflamme, R Havel, TF Cory, DG AF Fortunato, EM Viola, L Pravia, MA Knill, E Laflamme, R Havel, TF Cory, DG TI Exploring noiseless subsystems via nuclear magnetic resonance SO PHYSICAL REVIEW A LA English DT Article ID DECOHERENCE-FREE SUBSPACES; QUANTUM ERROR-CORRECTION; COMPUTATION; SYSTEMS; ENTANGLEMENT; COMPUTERS; PULSES; DESIGN; CODES AB Noiseless subsystems offer a general and efficient method for protecting quantum information in the presence of noise that has symmetry properties. A paradigmatic class of error models displaying nontrivial symmetries emerges under collective noise behavior, which implies a permutationally invariant interaction between the system and the environment. We expand our previous investigation of the noiseless subsystem idea [L. Viola , Science 293, 2059 (2001)] by reporting and analyzing NMR experiments that demonstrate the preservation of a qubit encoded in a three-qubit noiseless subsystem for general collective noise. A complete set of input states is used to determine the superoperator for the implemented one-qubit process and to confirm that the fidelity of entanglement is improved for a large, noncommutative set of engineered errors. To date, this is the largest set of error operators that has been successfully corrected for by any quantum code. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Perimeter Inst Theoret Phys, Waterloo, ON N2J 2W9, Canada. RP Viola, L (reprint author), Los Alamos Natl Lab, Mail Stop B256, Los Alamos, NM 87545 USA. EM lviola@lanl.gov NR 66 TC 23 Z9 25 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2003 VL 67 IS 6 AR 062303 DI 10.1103/PhysRevA.67.062303 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 696YM UT WOS:000183915200032 ER PT J AU Kim, YH Grice, WP AF Kim, YH Grice, WP TI Observation of correlated-photon statistics using a single detector SO PHYSICAL REVIEW A LA English DT Article ID 2-PHOTON INTERFERENCE EXPERIMENT; CONVERSION; COHERENCE AB We report experimental observations of correlated-photon statistics in the single-photon detection rate. The usual quantum interference in a two-photon polarization interferometer always accompanies a dip in the single-detector counting rate, regardless of whether a dip or a peak is seen in the coincidence rate. This effect is explained by taking into account all possible photon number states that reach the detector, rather than considering just the state postselected by the coincidence measurement. We also report an interferometeric scheme in which the interference peak or dip in the coincidence corresponds directly to a peak or a dip in the single-photon detection rate. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. RP Kim, YH (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. EM kimy@ornl.gov RI Kim, Yoonho/D-2591-2012; Grice, Warren/L-8466-2013 NR 17 TC 4 Z9 4 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2003 VL 67 IS 6 AR 065802 DI 10.1103/PhysRevA.67.065802 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 696YM UT WOS:000183915200142 ER PT J AU McKinsey, DN Brome, CR Dzhosyuk, SN Golub, R Habicht, K Huffman, PR Korobkina, E Lamoreaux, SK Mattoni, CEH Thompson, AK Yang, L Doyle, JM AF McKinsey, DN Brome, CR Dzhosyuk, SN Golub, R Habicht, K Huffman, PR Korobkina, E Lamoreaux, SK Mattoni, CEH Thompson, AK Yang, L Doyle, JM TI Time dependence of liquid-helium fluorescence SO PHYSICAL REVIEW A LA English DT Article ID BOMBARDED SUPERFLUID-HELIUM; ULTRAVIOLET EMISSION-SPECTRUM; MOLECULAR METASTABLE STATES; SCINTILLATION INTENSITY; NEUTRAL EXCITATION; ULTRACOLD NEUTRONS; DYNAMIC PROPERTIES; RECOMBINATION; LUMINESCENCE; TRANSITION AB The time dependence of extreme ultraviolet (EUV) fluorescence following an ionizing radiation event in liquid helium is observed and studied in the temperature range from 250 mK to 1.8 K. The fluorescence exhibits significant structure including a short (similar to10 ns) strong initial pulse followed by single photons whose emission rate decays exponentially with a 1.6-mus time constant. At an even longer time scale, the emission rate varies as "1/time" (inversely proportional to the time after the initial pulse). The intensity of the "1/time" component from beta particles is significantly weaker than those from alpha particles or neutron capture on He-3. It is also found that for alpha particles, the intensity of this component depends on the temperature of the superfluid helium. Proposed models describing the observed fluorescence are discussed. C1 Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Hahn Meitner Inst Berlin GmbH, D-1000 Berlin, Germany. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP McKinsey, DN (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. EM mckinsey@princeton.edu RI Habicht, Klaus/K-3636-2013 OI Habicht, Klaus/0000-0002-9915-7221 NR 46 TC 24 Z9 24 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2003 VL 67 IS 6 AR 062716 DI 10.1103/PhysRevA.67.062716 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 696YM UT WOS:000183915200074 ER PT J AU Southworth, SH Kanter, EP Krassig, B Young, L Armen, GB Levin, JC Ederer, DL Chen, MH AF Southworth, SH Kanter, EP Krassig, B Young, L Armen, GB Levin, JC Ederer, DL Chen, MH TI Double K-shell photoionization of neon SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-IMPACT; CROSS-SECTIONS; IONIZATION; HELIUM; PHOTON; SINGLE; EXCITATION; SPECTRA; ATOMS; RANGE AB Double K-shell photoionization of Ne at 5000 eV was observed by recording the KK-KLL Auger-electron hypersatellite spectrum. The measured Auger spectrum is compared with the results of multiconfiguration Dirac-Fock calculations. Shake calculations are used to identify likely multivacancy states produced by photoexcitation or ionization in addition to double-K vacancies, and their calculated Auger spectra are compared with the measured spectrum. The measured relative intensities of hypersatellite and diagram Auger lines are combined with experimental and theoretical determinations of branching ratios from single- and double-K vacancies into final states to determine the ratio of double-to-single K-shell photoionization cross sections to be 0.32(4)%. This ratio is much larger than the calculated high-energy-limit ratio and indicates a large contribution of dynamic electron correlation. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Tennessee, Knoxville, TN 37996 USA. Tulane Univ, New Orleans, LA 70118 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Southworth, SH (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 45 Z9 45 U1 1 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2003 VL 67 IS 6 AR 062712 DI 10.1103/PhysRevA.67.062712 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 696YM UT WOS:000183915200070 ER PT J AU Jung, MH Alsmadi, A Kim, HC Bang, YY Ahn, KH Umeo, K Lacerda, AH Nakotte, H Ri, HC Takabatake, T AF Jung, MH Alsmadi, A Kim, HC Bang, YY Ahn, KH Umeo, K Lacerda, AH Nakotte, H Ri, HC Takabatake, T TI Superconductivity in magnetically ordered CeTe1.82 SO PHYSICAL REVIEW B LA English DT Article ID FERROMAGNETIC METALS; CETE2; TRANSPORT; PRESSURE; ELECTRON; BEHAVIOR AB We report the discovery of pressure-induced superconductivity in a semimetallic magnetic material CeTe1.82. The superconducting transition temperature T-c=2.7 K (well below the magnetic ordering temperatures) under pressure (>2 kbar) is remarkably high, considering the relatively low carrier density due to a charge-density-wave transition associated with lattice modulation. The mixed magnetic structure of antiferromagnetism coexisting with ferromagnetism can provide a clue for this high T-c. We discuss a possible theoretical model for the superconducting pairing mechanism. C1 Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Korea Basic Sci Inst, Mat Sci Lab, Taejon 305333, South Korea. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Hiroshima Univ, Dept Quantum Matter, ADSM, Higashihiroshima 7398530, Japan. RP Jung, MH (reprint author), Korea Basic Sci Inst, MSL, Taejon 305333, South Korea. EM mhjung@kbsi.re.kr RI Takabatake, Toshiro/L-2882-2014 OI Takabatake, Toshiro/0000-0002-3293-8592 NR 24 TC 17 Z9 17 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2003 VL 67 IS 21 AR 212504 DI 10.1103/PhysRevB.67.212504 PG 4 WC Physics, Condensed Matter SC Physics GA 698QW UT WOS:000184011100021 ER PT J AU Luning, J Nolting, F Scholl, A Ohldag, H Seo, JW Fompeyrine, J Locquet, JP Stohr, J AF Luning, J Nolting, F Scholl, A Ohldag, H Seo, JW Fompeyrine, J Locquet, JP Stohr, J TI Determination of the antiferromagnetic spin axis in epitaxial LaFeO3 films by x-ray magnetic linear dichroism spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION-SPECTROSCOPY; CIRCULAR-DICHROISM; THIN-FILMS; NEUTRON-DIFFRACTION; ANGULAR-DEPENDENCE; ELECTRON-YIELD; SUM-RULES; FE; ANISOTROPY; MOMENTS AB We report x-ray magnetic linear dichroism (XMLD) measurements at the Fe L-2,L-3 absorption edges of thin antiferromagnetic (AFM) LaFeO3 films grown epitaxially on SrTiO3 (100) and (110) substrates and a stepped (100) substrate with a 2degrees miscut. The spin structure in the near-surface region of the thin films, and in particular the orientation of the AFM axis, has been derived from the observed polarization dependence. We show that in all cases, the orientation of the AFM axis differs from that of bulk LaFeO3. In particular, we find that the AFM axis is rotated away from its bulk orientation and lies parallel to the (111) plane of the underlying cubic SrTiO3 substrate, with its projection on the film surface parallel to the c axis of the orthorhombic LaFeO3 crystal lattice. Our results are of importance in light of existing models for the exchange coupling and bias of antiferromagnetic/ferromagnetic multilayers. They indicate the inadequacy of models that assume a bulk like spin structure near surfaces and interfaces. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. IBM Corp, Div Res, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland. Univ Neuchatel, Inst Phys, CH-2000 Neuchatel, Switzerland. RP Luning, J (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RI Seo, Jin Won/J-3980-2013; Scholl, Andreas/K-4876-2012; Ohldag, Hendrik/F-1009-2014 OI Seo, Jin Won/0000-0003-4937-0769; NR 50 TC 50 Z9 50 U1 7 U2 39 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 JUN 1 PY 2003 VL 67 IS 21 AR 214433 DI 10.1103/PhysRevB.67.214433 PG 14 WC Physics, Condensed Matter SC Physics GA 698QW UT WOS:000184011100062 ER PT J AU Martinho, H Rettori, C Huber, DL Mitchell, JF Oseroff, SB AF Martinho, H Rettori, C Huber, DL Mitchell, JF Oseroff, SB TI Low-energy spin-wave excitations in the bilayered magnetic manganite La2-2xSr1+2xMn2O7 (0.30 <= x <= 0.50) SO PHYSICAL REVIEW B LA English DT Article ID EQUAL-TO 0.50; GIANT MAGNETORESISTANCE; NEUTRON-SCATTERING; LA1.2SR1.8MN2O7; TRANSITION; CRYSTAL AB We have studied the low-temperature behavior of the magnetization and specific heat of the bilayered perovskite system La2-2xSr1+2xMn2O7 for 0.30less than or equal toxless than or equal to0.50. Our analysis reveals that below 30 K the temperature dependence of the magnetization of the ferromagnetic samples, x=0.30, 0.32, and 0.36, in a field of 1 T can be interpreted in terms of the thermal excitations of a two-dimensional gas of ferromagnetic magnons. The specific heat in zero field for these samples, such as for the x=0.50 antiferromagnetic one, is linear with temperature in the range of 1.8 K less than or equal toTless than or equal to10 K. This behavior can be also explained by the magnon gas model. By comparing specific heat measurements in zero field with those taken in a field of 9 T we are able to extract the lattice and electronic contributions and determine the in-plane exchange interactions. They are found to be in reasonable agreement with the values inferred from analysis of the magnetization data and also with the values reported by inelastic neutron scattering studies. In addition, we found that the electronic density of states obtained for the x=0.50 sample is in agreement with previous band structure calculations. C1 Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. San Diego State Univ, San Diego, CA 92182 USA. RP Martinho, H (reprint author), Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. EM hercules@ifi.unicamp.br RI Rettori, Carlos/C-3966-2012; Martinho, Herculano/F-4684-2015; Optica e Eletronica, Laboratorio/A-8669-2014; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Rettori, Carlos/0000-0001-6692-7915; NR 18 TC 5 Z9 5 U1 1 U2 4 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 JUN 1 PY 2003 VL 67 IS 21 AR 214428 DI 10.1103/PhysRevB.67.214428 PG 7 WC Physics, Condensed Matter SC Physics GA 698QW UT WOS:000184011100057 ER PT J AU Rutel, IB Zvyagin, SA Brooks, JS Krzystek, J Kuhns, P Reyes, AP Jobiliong, E Ward, BH Schlueter, JA Winter, RW Gard, GL AF Rutel, IB Zvyagin, SA Brooks, JS Krzystek, J Kuhns, P Reyes, AP Jobiliong, E Ward, BH Schlueter, JA Winter, RW Gard, GL TI High-field magnetic resonant properties of beta '-(ET)(2)SF5CF2SO3 SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-SPIN-RESONANCE; BEDT-TTF; ANION INTERACTION; CHARGE-TRANSFER; SALTS; PHASE; SPECTROSCOPY; TRANSITION; CLO4; BR AB The charge transfer salt beta(')-(ET)(2)SF5CF2SO3, which has previously been considered a spin-Peierls material with a T(SP)similar to33 K, is examined using high-resolution high-field sub-millimeter/millimeter wave electron spin resonance (ESR), and nuclear magnetic resonance (NMR) techniques. A peak in the nuclear spin-lattice relaxation behavior in fields of 8 T, accompanied by a broadening and paramagnetic shift of the resonance line, indicates a phase transition at T(c)similar to20 K. A pronounced change in the high-field ESR excitation spectra at similar to24 T, observed at T(c)similar to20 K, may indicate the onset of antiferromagnetic (AFM) correlations of the low-temperature phase in beta(')-(ET)(2)SF5CF2SO3. Peculiarities of the low-temperature magnetic and resonance properties of beta(')-(ET)(2)SF5CF2SO3 are discussed. C1 Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32310 USA. Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Portland State Univ, Dept Chem, Portland, OR 97207 USA. RP Rutel, IB (reprint author), Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. RI Zvyagin, Sergei/H-8389-2014 NR 23 TC 1 Z9 1 U1 0 U2 4 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 JUN 1 PY 2003 VL 67 IS 21 AR 214417 DI 10.1103/PhysRevB.67.214417 PG 6 WC Physics, Condensed Matter SC Physics GA 698QW UT WOS:000184011100046 ER PT J AU Venturini, EL Samara, GA Kleemann, W AF Venturini, EL Samara, GA Kleemann, W TI Pressure as a probe of dielectric properties and phase transition of doped quantum paraelectrics: Sr1-xCaxTiO3 (x=0.007) SO PHYSICAL REVIEW B LA English DT Article ID SRTIO3; FERROELECTRICITY; KTA1-XNBXO3; DEPENDENCE; DYNAMICS; BEHAVIOR; CLUSTER; GLASS AB Pressure is shown to have a very strong influence on the glass-like (relaxor) dielectric response of Sr1-xCaxTiO3 (x=0.007), or SCT (0.007), reducing the dielectric susceptibility and lowering the glass transition temperature, T-m, at the very rapid rate of similar to35 K/kbar. Above 0.5 kbar there is complete suppression of the transition and relaxor state and evolution of a quantum paraelectric state at low temperatures. These effects can be understood in terms of the increase of the ferroelectric soft mode frequency, omega(s), with pressure which strongly reduces the polarizability, and thereby the correlation length, r(c), for dipolar interactions. It is estimated that above 0.5 kbar r(c) becomes significantly smaller than the average separation between neighboring Ca2+ ions (2.1 nm) leading to loss of overlap and correlations between adjacent nano-domains and loss of the relaxational character of the dielectric response. While pressure lowers T-m, the application of a dc biasing electric fields raises T-m and can reinstate a ferroelectric state at modest pressures. The interplay between pressure and dc field provides insights into the physics. The very large pressure and field effects observed are attributed to the small characteristic energies of the crystal in the quantum regime. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Venturini, EL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 9 Z9 10 U1 1 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 JUN 1 PY 2003 VL 67 IS 21 AR 214102 DI 10.1103/PhysRevB.67.214102 PG 7 WC Physics, Condensed Matter SC Physics GA 698QW UT WOS:000184011100024 ER PT J AU Yan, YF Al-Jassim, MM AF Yan, YF Al-Jassim, MM TI Solubility, diffusion, and precipitation of oxygen impurities in MgB2 SO PHYSICAL REVIEW B LA English DT Article ID CRITICAL-CURRENT DENSITY; SUPERCONDUCTING MGB2; MAGNESIUM-DIBORIDE; THIN-FILMS; MOLECULAR-DYNAMICS; PSEUDOPOTENTIALS; TRANSITION; DEFECTS; FIELD; WIRES AB We investigate the structure and energetics of native and oxygen-related defects in MgB2. First-principles total-energy calculations reveal that the nonstoichiometry in MgB2 can be very small. Oxygen impurities have high solubility in MgB2 at O-rich growth conditions. However, the presence of excess Mg during the growth can dramatically reduce oxygen incorporation by forming MgO precipitates. Oxygen impurities are found to exist in atomic form in MgB2. Interstitial oxygen atoms are very mobile, with an activation energy of 1.3 eV, indicating that they can be annealed out ex situ in Mg vapor. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Yan, YF (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 28 TC 11 Z9 12 U1 1 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 JUN 1 PY 2003 VL 67 IS 21 AR 212503 DI 10.1103/PhysRevB.67.212503 PG 4 WC Physics, Condensed Matter SC Physics GA 698QW UT WOS:000184011100020 ER PT J AU Davids, B van den Berg, AM Dendooven, P Fleurot, F Hunyadi, M de Huu, MA Siemssen, RH Wilschut, HW Wortche, HJ Hernanz, M Jose, J Rehm, KE Wuosmaa, AH Segel, RE AF Davids, B van den Berg, AM Dendooven, P Fleurot, F Hunyadi, M de Huu, MA Siemssen, RH Wilschut, HW Wortche, HJ Hernanz, M Jose, J Rehm, KE Wuosmaa, AH Segel, RE TI Astrophysical rate of O-15(alpha,gamma)Ne-19 via the (p, t) reaction in inverse kinematics SO PHYSICAL REVIEW C LA English DT Article ID CLASSICAL NOVAE; RP PROCESS; ALPHA; NUCLEOSYNTHESIS; STRENGTHS; DECAY; NE-19; F-19 AB A recoil coincidence technique has been applied to measure the alpha-decay branching ratios of near-threshold states in Ne-19. Populating these states using the (p,t) reaction in inverse kinematics, we detected the recoils and their decay products with 100% geometric efficiency using a magnetic spectrometer. Combining our branching ratio measurements with independent determinations of the radiative widths of these states, we calculate the astrophysical rate of O-15(alpha,gamma)Ne-19. Using this reaction rate, we perform hydrodynamic calculations of nova outbursts and conclude that no significant breakout from the hot CNO cycles into the rp process occurs in novae via O-15(alpha,gamma)Ne-19. C1 Univ Groningen, Kernfys Versneller Inst, NL-9747 AA Groningen, Netherlands. Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. Univ Politecn Catalunya, Dept Fis & Engn Nucl, E-08800 Barcelona, Spain. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Northwestern Univ, Dept Phys, Evanston, IL 60208 USA. RP Davids, B (reprint author), Univ Groningen, Kernfys Versneller Inst, Zernikelaan 25, NL-9747 AA Groningen, Netherlands. EM davids@kvi.nl RI Hernanz, Margarita/K-1770-2014; van den Berg, Adriaan/P-6792-2015 OI Hernanz, Margarita/0000-0002-8651-7910; NR 34 TC 39 Z9 39 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 065808 DI 10.1103/PhysRevC.67.065808 PG 8 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900065 ER PT J AU Fischer, SM Lister, CJ Balamuth, DP AF Fischer, SM Lister, CJ Balamuth, DP TI Unravelling the band crossings in Se-68 and Kr-72: The quest for T=0 pairing SO PHYSICAL REVIEW C LA English DT Article ID PROTON-NEUTRON CORRELATIONS; SHAPE COEXISTENCE; N=Z NUCLEI; HIGH-SPIN; ROTATIONAL BANDS; ALIGNMENT; GAMMASPHERE AB High-spin band crossings in N=Z nuclei have been suggested to contain information on T=0 neutron-proton pairing correlations. Several experiments that produced high angular momentum states in the N=Z nuclei Se-68(34) and Kr-72(36) have been carried out. Levels in these neutron deficient nuclei were populated through heavy-ion fusion reactions and their subsequent gamma decay was measured with Gammasphere. The combination of these data allowed the level sequence in yrast and near yrast bands to be firmly established, extended to higher spin, and has resolved some previously published discrepancies. The yrast sequence in Se-68 was extended to spin J=26 and a new band crossing observed. In Kr-72, the ground state band was found to fork into three bands, each of which has irregularities in its moment of inertia. Differential Doppler shift measurements indicate that the two high-spin bands have very different shapes. Similar, sharp band crossings were established in both nuclei. A comparison of these data with recent measurements of N=Z+2 nuclei Se-70 and Kr-74 allowed the issue of "delayed alignments'' to be addressed in detail. No clear-cut evidence for any delay was found. C1 De Paul Univ, Dept Phys, Chicago, IL 60614 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. RP Fischer, SM (reprint author), De Paul Univ, Dept Phys, Chicago, IL 60614 USA. NR 52 TC 63 Z9 65 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 064318 DI 10.1103/PhysRevC.67.064318 PG 13 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900032 ER PT J AU Fotiades, N Cizewski, JA Krucken, R McNabb, DP Becker, JA Bernstein, LA Younes, W Clark, RM Fallon, P Lee, IY Macchiavelli, AO AF Fotiades, N Cizewski, JA Krucken, R McNabb, DP Becker, JA Bernstein, LA Younes, W Clark, RM Fallon, P Lee, IY Macchiavelli, AO TI High-spin states in odd-odd Rh-106,Rh-108,Rh-110,Rh-112 SO PHYSICAL REVIEW C LA English DT Article ID BAND STRUCTURES; RH-100; ISOTOPES AB The level structures of Rh-106,Rh-108,Rh-110,Rh-112 have been studied in the fission of the compound system formed in three different heavy-ion induced reactions. Sequences of five transitions, together with weak crossover transitions, have been assigned to each isotope based on coincidences with known transitions in the complementary fragments. Comparison with the lighter odd-odd Rh isotopes supports assignment of these sequences as the yrast bands built on the pig(9/2)xnuh(11/2) configuration. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. Tech Univ Munich, Dept Phys E12, D-85748 Garching, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Fotiades, N (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 18 TC 17 Z9 17 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 064304 DI 10.1103/PhysRevC.67.064304 PG 6 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900018 ER PT J AU Ginter, TN Gregorich, KE Loveland, W Lee, DM Kirbach, UW Sudowe, R Folden, CM Patin, JB Seward, N Wilk, PA Zielinski, PM Aleklett, K Eichler, R Nitsche, H Hoffman, DC AF Ginter, TN Gregorich, KE Loveland, W Lee, DM Kirbach, UW Sudowe, R Folden, CM Patin, JB Seward, N Wilk, PA Zielinski, PM Aleklett, K Eichler, R Nitsche, H Hoffman, DC TI Confirmation of production of element 110 by the Pb-208(Ni-64,n) reaction SO PHYSICAL REVIEW C LA English DT Article ID DECAY; SEPARATOR AB We report the experimental confirmation of the production of element 110. In the bombardment of a Pb-208 target with a 309-MeV Ni-64 beam, we have observed two chains of time- and position-correlated events. Each chain consisted of the implantation of an evaporation residue followed by the emission of alpha particles. We attribute these two chains to the decay of (271)110 produced with a cross section of 8.3(-5.3)(+11) pb. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Surrey, Dept Phys, Surrey, England. Uppsala Univ, Uppsala, Sweden. Paul Scherrer Inst, Villigen, Switzerland. RP Ginter, TN (reprint author), Michigan State Univ, Natl Supercond Cyclotron Lab, E Lansing, MI 48824 USA. RI Wilk, Philip/B-5954-2008; Eichler, Robert/G-5130-2011; Folden, Charles/F-1033-2015 OI Folden, Charles/0000-0002-2814-3762 NR 24 TC 105 Z9 107 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 064609 DI 10.1103/PhysRevC.67.064609 PG 5 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900041 ER PT J AU Guber, KH Koehler, PE Derrien, H Valentine, TE Leal, LC Sayer, RO Rauscher, T AF Guber, KH Koehler, PE Derrien, H Valentine, TE Leal, LC Sayer, RO Rauscher, T TI Neutron capture reaction rates for silicon and their impact on the origin of presolar mainstream SiC grains SO PHYSICAL REVIEW C LA English DT Article ID SOLAR-SYSTEM FORMATION; CARBIDE GRAINS; CROSS-SECTIONS; MURCHISON METEORITE; NUCLEOSYNTHESIS; ND; ANOMALIES; CHONDRITE; EVOLUTION; CARBON AB We have made new, improved measurements of the Si28-30 (n, gamma) cross sections and have done a resonance analysis of these data including previous total cross sections. Together with the calculated contributions due to direct capture, we calculated the astrophysical (n, gamma) reaction rates and investigated the s-process abundances of the Si isotopes. Measured isotopic anomalies of intermediate and heavy elements in SiC grains from meteorites appear to be attributable to the s-process in asymptotic giant branch (AGB) stars. But the Si isotopic ratios in these grains are substantially different than s-process models predict. Therefore, recent papers have invoked galactic chemical evolution or other effects to explain the Si isotope ratios in these grains. Our new reaction rates are significantly different than previous rates, and s-process calculations using these rates lead to much larger isotopic shifts in Si-30. However, these exploratory calculations demonstrate that even with these substantially different rates the large observed variation in SiC grain from AGB stars cannot be explained by standard s-process models. C1 Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Basel, Inst Phys, CH-4056 Basel, Switzerland. RP Guber, KH (reprint author), Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. RI Rauscher, Thomas/D-2086-2009 OI Rauscher, Thomas/0000-0002-1266-0642 NR 32 TC 25 Z9 25 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 062802 DI 10.1103/PhysRevC.67.062802 PG 5 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900008 ER PT J AU Langfeld, K Markum, H Pullirsch, R Roberts, CD Schmidt, SM AF Langfeld, K Markum, H Pullirsch, R Roberts, CD Schmidt, SM TI Concerning the quark condensate SO PHYSICAL REVIEW C LA English DT Article ID CHIRAL-SYMMETRY-BREAKING; RANDOM-MATRIX THEORY; DYSON-SCHWINGER EQUATIONS; LATTICE GAUGE-THEORY; QCD DIRAC OPERATOR; FINITE-TEMPERATURE; INFRARED BEHAVIOR; CONFINEMENT; SPECTRUM; CONTINUUM AB A continuum expression for the trace of the massive dressed-quark propagator is used to explicate a connection between the infrared limit of the QCD Dirac operator's spectrum and the quark condensate appearing in the operator product expansion. This connection is verified via comparison with a lattice-QCD simulation. The pseudoscalar vacuum polarization provides a good approximation to the condensate over a larger range of current-quark masses. C1 Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. Tech Univ Vienna, Atominst, A-1040 Vienna, Austria. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. Helmholtz Gemeinschaft, D-53175 Bonn, Germany. RP Langfeld, K (reprint author), Univ Tubingen, Inst Theoret Phys, Morgenstelle 14, D-72076 Tubingen, Germany. OI Langfeld, Kurt/0000-0002-4368-3580 NR 37 TC 38 Z9 38 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 065206 DI 10.1103/PhysRevC.67.065206 PG 7 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900056 ER PT J AU Marginean, N Bucurescu, D Alvarez, CR Ur, CA Skouras, LD Johnstone, LP Bazzacco, D Lunardi, S de Angelis, G Axiotis, M Farnea, E Gadea, A Ionescu-Bujor, M Iordachescu, A Krolas, W Kroll, T Lenzi, SM Martinez, T Marginean, R Menegazzo, R Napoli, DR Pavan, P De Poli, M Quintana, B Rusu, C Spolaore, P Wrzesinski, J AF Marginean, N Bucurescu, D Alvarez, CR Ur, CA Skouras, LD Johnstone, LP Bazzacco, D Lunardi, S de Angelis, G Axiotis, M Farnea, E Gadea, A Ionescu-Bujor, M Iordachescu, A Krolas, W Kroll, T Lenzi, SM Martinez, T Marginean, R Menegazzo, R Napoli, DR Pavan, P De Poli, M Quintana, B Rusu, C Spolaore, P Wrzesinski, J TI Yrast isomers in Ag-95, Pd-95, and Pd-94 SO PHYSICAL REVIEW C LA English DT Article ID SHELL-MODEL CALCULATIONS; HIGH ANGULAR-MOMENTUM; 80-100 MASS REGION; HIGH-SPIN ISOMERS; LEVEL STRUCTURE; IN-BEAM; NUCLEI; STATES; DECAY AB The yrast level schemes of three neutron deficient nuclei with mass A approximate to 95 have been studied with the reaction Ni-58 + Ca-40 at 135 MeV, using the GASP gamma-ray array, the ISIS silicon ball, and the n-ring neutron detector. Excited levels, including a (23/2(+)) spin-gap isomer, are reported for the first time in the heaviest N = Z + 1 nucleus experimentally investigated, Ag-95. In Pd-95, the yrast line above the ground state has been observed and connected to states above the known isomeric level 21/2(+), showing for the first time that this is indeed a spin-gap isomer. In Pd-94, the 95.6-keV isomeric transition was confirmed, and its E2 character was firmly established. The experimental observations are compared with current shell-model calculations. C1 Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. H Hulubei Natl Inst Phys & Nucl Engn, Bucharest, Romania. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Sez Padova, Padua, Italy. NCSR Demokritos, Inst Nucl Phys, Aghia Paraskevi, Greece. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. Inst Nucl Phys, Krakow, Poland. Univ Salamanca, Grp Fis Nucl, E-37008 Salamanca, Spain. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RP Marginean, N (reprint author), Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. RI Lenzi, Silvia/I-6750-2012; Axiotis, Michail/D-3550-2013; Krolas, Wojciech/N-9391-2013; Martinez, Trinitario/K-6785-2014; Gadea, Andres/L-8529-2014; Marginean, Nicolae Marius/C-4732-2011; Napoli, Daniel R./D-9863-2012; Menegazzo, Roberto/J-5853-2012 OI Martinez, Trinitario/0000-0002-0683-5506; Gadea, Andres/0000-0002-4233-1970; Napoli, Daniel R./0000-0002-8154-6958; Menegazzo, Roberto/0000-0002-3060-5276 NR 21 TC 23 Z9 23 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 061301 DI 10.1103/PhysRevC.67.061301 PG 5 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900002 ER PT J AU Rehm, KE Wuosmaa, AH Jiang, CL Caggiano, J Greene, JP Heinz, A Henderson, D Janssens, RVF Moore, EF Mukherjee, G Pardo, RC Pennington, T Schiffer, JP Siemssen, RH Paul, M Jisonna, L Segel, RE AF Rehm, KE Wuosmaa, AH Jiang, CL Caggiano, J Greene, JP Heinz, A Henderson, D Janssens, RVF Moore, EF Mukherjee, G Pardo, RC Pennington, T Schiffer, JP Siemssen, RH Paul, M Jisonna, L Segel, RE TI Branching ratio Gamma(alpha)/Gamma(gamma) of the 4.033 MeV 3/2(+) state in Ne-19 SO PHYSICAL REVIEW C LA English DT Article ID LIGHT-NUCLEI; REACTION-RATES; ENERGY-LEVELS; ALPHA; STRENGTHS; NE-20 AB The branching ratio Gamma(alpha)/Gamma(gamma) of the 4.033 MeV 3/2(+) state in Ne-19 plays a crucial role in the breakout from the hot CNO cycle into the rapid proton capture process. This ratio has been studied by making use of the advantages of inverse kinematics. The state was populated via the He-3(Ne-20, alpha) Ne-19* reaction and its decay via gamma or alpha emission was measured by detecting the heavy reaction products (Ne-19 or O-15) in coincidence in a magnetic spectrograph. An upper limit Gamma(alpha)/Gamma(gamma) less than or equal to 6x10(-4) has been obtained. With these results, the astrophysical reaction rate for the O-15 (alpha,gamma) Ne-19 reaction has been calculated. Its influence on the breakout at various astrophysical sites, novas, x-ray bursts, and supermassive stars, is discussed. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Hebrew Univ Jerusalem, Jerusalem, Israel. Northwestern Univ, Evanston, IL 60208 USA. RP Rehm, KE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Heinz, Andreas/E-3191-2014 NR 31 TC 24 Z9 24 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 065809 DI 10.1103/PhysRevC.67.065809 PG 9 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900066 ER PT J AU Sato, T Uno, D Lee, TSH AF Sato, T Uno, D Lee, TSH TI Dynamical model of weak pion production reactions SO PHYSICAL REVIEW C LA English DT Article ID CHIRAL PERTURBATION-THEORY; GAMMA-N->PI-N REACTION; DELTA(1232) REGION; GAUGE-INVARIANT; QUARK-MODEL; PHOTOPRODUCTION; AMPLITUDES; NUCLEON; UNITARY; ELECTROPRODUCTION AB The dynamical model of pion electroproduction developed by Sato and Lee [Phys. Rev. C 63, 055201 (2001)] has been extended to investigate the weak pion production reactions. With the conserved vector current hypothesis, the weak vector currents are constructed from electromagnetic currents by isospin rotations. Guided by the effective chiral Lagrangian method and using the unitary transformation method developed previously, the weak axial vector currents for pi production are constructed with no adjustable parameters. In particular, the N-Delta transitions at Q(2)-->0 are calculated from the constituent quark model and their Q(2) dependence is assumed to be identical to that determined in the study of pion electroproduction. The main feature of our approach is to renormalize these bare N-Delta form factors with the dynamical pion cloud effects originating from the nonresonant pi production mechanisms. The predicted cross sections of neutrino-induced pion production reactions, N(nu(mu), mu(-)pi) N, are in good agreement with the existing data. We show that the renormalized (dressed) axial N-Delta form factor contains large dynamical pion cloud effects and these renormalization effects are crucial in getting agreement with the data. We conclude that the N-Delta transitions predicted by the constituent quark model are consistent with the existing neutrino-induced pion production data in the Delta region, contrary to the previous observations. This is consistent with our previous findings in the study of pion electroproduction reactions. However, more extensive and precise data of neutrino-induced pion production reactions are needed to further test our model and to pin down the Q(2) dependence of the axial vector N-Delta transition form factor. C1 Osaka Univ, Dept Phys, Osaka 5600043, Japan. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Sato, T (reprint author), Osaka Univ, Dept Phys, Osaka 5600043, Japan. NR 37 TC 87 Z9 87 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 065201 DI 10.1103/PhysRevC.67.065201 PG 13 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900051 ER PT J AU Sienko, TA Lister, CJ Kaye, RA AF Sienko, TA Lister, CJ Kaye, RA TI gamma vibrational band and quasiparticle excitations in Sr-80 SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON-DEFICIENT NUCLEI; HIGH-SPIN STATES; TRANSITION STRENGTHS; SUPERDEFORMED BANDS; STRONTIUM ISOTOPES; DEFORMATION; SR; SOFTNESS; REGION; ATLAS AB Non-yrast states in Sr-80 were populated in the Mg-24(Ni-58,2p)Sr-80 reaction at 200 MeV and their g decays investigated using Gammasphere, in order to investigate shape softness and quasiparticle excitations. A large data set was collected which was A and Z gated, using the Argonne Fragment Mass Analyzer and a focal plane ion chamber. The excellent channel selection enhanced the sensitivity to energetically nonfavored configurations. Several new rotational bands were found, and many conflicts between previous experiments were resolved. In particular, the gamma vibrational band is now clearly delineated, and more than ten quasiparticle bandheads have been identified. At the highest spins, evidence for a long-predicted shape change was found. C1 Purdue Univ Calumet, Dept Chem & Phys, Hammond, IN 46323 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Sienko, TA (reprint author), Purdue Univ Calumet, Dept Chem & Phys, Hammond, IN 46323 USA. NR 32 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 064311 DI 10.1103/PhysRevC.67.064311 PG 8 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900025 ER PT J AU Starostin, A Nefkens, BMK Manley, DM Abaev, VV Allgower, CE Bekrenev, V Briscoe, WJ Clajus, M Comfort, JR Craig, K Grosnick, D Isenhower, D Knecht, N Koetke, DD Koulbardis, AA Kozlenko, NG Kruglov, S Lolos, G Lopatin, IV Manweiler, R Marusic, A McDonald, S Olmsted, J Papandreou, Z Peaslee, DC Phaisangittisakul, N Prakhov, S Price, JW Ramirez, AF Sadler, M Shafi, A Spinka, H Stanislaus, TDS Staudenmaier, HM Supek, I Tippens, WB AF Starostin, A Nefkens, BMK Manley, DM Abaev, VV Allgower, CE Bekrenev, V Briscoe, WJ Clajus, M Comfort, JR Craig, K Grosnick, D Isenhower, D Knecht, N Koetke, DD Koulbardis, AA Kozlenko, NG Kruglov, S Lolos, G Lopatin, IV Manweiler, R Marusic, A McDonald, S Olmsted, J Papandreou, Z Peaslee, DC Phaisangittisakul, N Prakhov, S Price, JW Ramirez, AF Sadler, M Shafi, A Spinka, H Stanislaus, TDS Staudenmaier, HM Supek, I Tippens, WB CA Crsytal Ball Collaboration TI Measurement of the pi(-)p -> 3 pi(0)n total cross section from threshold to 0.75 GeV/c SO PHYSICAL REVIEW C LA English DT Article ID CHARGE-EXCHANGE SCATTERING AB We report a new measurement of the pi(-)p-->3pi(0)n total cross section from threshold to p(pi)=0.75 GeV/c. The cross section near the N(1535)1/2(-) resonance is only a few mub after subtracting the large eta-->3pi(0) background associated with pi(-)p-->etan. A simple analysis of our data results in the estimated branching fraction B[S-11-->piN(1440)1/2(+)]=(8+/-2)%. This is the first such estimate obtained with a three-pion production reaction. C1 Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Kent State Univ, Kent, OH 44242 USA. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. George Washington Univ, Washington, DC 20052 USA. Arizona State Univ, Tempe, AZ 85287 USA. Valparaiso Univ, Valparaiso, IN 46383 USA. Abilene Christian Univ, Abilene, TX 79699 USA. Univ Regina, Regina, SK S4S 0A2, Canada. Univ Maryland, College Pk, MD 20742 USA. Univ Karlsruhe, D-76128 Karlsruhe, Germany. Rudjer Boskovic Inst, Zagreb 10002, Croatia. RP Starostin, A (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA. NR 13 TC 8 Z9 8 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 068201 DI 10.1103/PhysRevC.67.068201 PG 4 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900072 ER PT J AU Titov, AI Lee, TSH AF Titov, AI Lee, TSH TI Spin effects and baryon resonance dynamics in phi-meson photoproduction at few GeV SO PHYSICAL REVIEW C LA English DT Article ID LARGE MOMENTUM-TRANSFER; QUARK-MODEL; POLARIZATION OBSERVABLES; VECTOR-MESONS; HYPERFINE INTERACTIONS; STRANGENESS CONTENT; ELASTIC-SCATTERING; GAUGE-INVARIANCE; NEAR-THRESHOLD; HIGH-ENERGIES AB The diffractive phi-meson photoproduction amplitude is dominated by the Pomeron-exchange process and contains the terms that govern the spin-spin and spin-orbital interactions. We show that these terms are responsible for the spin-flip transitions at forward photoproduction angles and appear in the angular distributions of phi-->K+K- decay in reactions with unpolarized and polarized photon beams. At large momentum transfers, the main contribution to the phi-meson photoproduction is found to be due to the excitation of nucleon resonances. Combined analysis of omega and phi photoproduction indicates strong Okubo-Zweig-Iizuka-rule violation in phiNN* couplings. We also show that the spin observables are sensitive to the dynamics of phi-meson photoproduction at large angles and could help to distinguish different theoretical models of nucleon resonances. Predictions for spin effects in phi-meson photoproduction are presented for future experimental tests. C1 Japan Atom Energy Res Inst, Adv Sci Res Ctr, Ibaraki 3191195, Japan. Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Russia. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Titov, AI (reprint author), Japan Atom Energy Res Inst, Adv Sci Res Ctr, Ibaraki 3191195, Japan. NR 82 TC 44 Z9 44 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 065205 DI 10.1103/PhysRevC.67.065205 PG 17 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900055 ER PT J AU Tryggestad, E Baumann, T Heckman, P Thoennessen, M Aumann, T Bazin, D Blumenfeld, Y Beene, JR Lewis, TA Radford, DC Shapira, D Varner, RL Chartier, M Halbert, ML Liang, JF AF Tryggestad, E Baumann, T Heckman, P Thoennessen, M Aumann, T Bazin, D Blumenfeld, Y Beene, JR Lewis, TA Radford, DC Shapira, D Varner, RL Chartier, M Halbert, ML Liang, JF TI Low-lying E1 strength in O-20 SO PHYSICAL REVIEW C LA English DT Article ID INELASTIC ELECTRON-SCATTERING; RICH OXYGEN ISOTOPES; NUCLEAR SHELL-MODEL; DIPOLE STRENGTH; ELECTROMAGNETIC-EXCITATION; CROSS-SECTIONS; PARITY STATES; ENERGY-LEVELS; LIGHT-NUCLEI; DRIP-LINE AB Intermediate energy Coulomb excitation at 100 MeV/nucleon was used to probe the low-lying level structure of both O-18 and O-20 in the region between 1 and 8 MeV. Discrete 1(-) states with energies of 5.35(10) and 6.85(5) MeV were observed in O-20. The strong direct excitation and subsequent gamma-ray decay of these states, along with B(Elambda) predictions for O-18,O-20 levels in this energy region, established their dipole character. The extracted B(E1)up arrow values of 0.062(16)e(2) fm(2) and 0.035(9)e(2) fm(2) for the 5.35- and 6.85-MeV states, respectively, are significantly larger than shell model calculations, though modification of the single-particle energies, in particular, the p-sd shell gap, improves the agreement. The summed B(E1)up arrow value for these levels (in Weisskopf units) is consistent with that for other nuclei that have been discussed recently in the literature as potential Pygmy dipole resonance hosts. C1 Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. RP Tryggestad, E (reprint author), Inst Phys Nucl, IN2P3, CNRS, BP 1, F-91406 Orsay, France. EM tryggest@ipno.in2p3.fr RI Aumann, Thomas/B-1455-2012; radford, David/A-3928-2015 NR 50 TC 43 Z9 43 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 064309 DI 10.1103/PhysRevC.67.064309 PG 14 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900023 ER PT J AU van Dalen, ENE Dieperink, AEL Tjon, JA AF van Dalen, ENE Dieperink, AEL Tjon, JA TI Neutrino emission in neutron stars SO PHYSICAL REVIEW C LA English DT Article ID NUCLEON-NUCLEON-SCATTERING; SPECTRAL-FUNCTION; AXIAL-CHARGE; DENSE MATTER; BREMSSTRAHLUNG; EMISSIVITIES; ENHANCEMENT; CORES AB Neutrino emissivities in a neutron star are computed for the neutrino bremsstrahlung process. In the first part, the electroweak nucleon-nucleon bremsstrahlung is calculated in free space in terms of an on-shell T matrix using a generalized low-energy theorem. In the second part, the emissivities are calculated in terms of the hadronic polarization at the two-loop level. Various medium effects, such as finite particle width, Pauli blocking in the T matrix are considered. Compared to the pioneering work of Friman and Maxwell in terms of (antisymmetrized) one-pion exchange, the resulting emissivity is about a factor 4 smaller at saturation density. C1 Univ Groningen, Kernfys Versneller Inst, Theory Grp, NL-9747 AA Groningen, Netherlands. ECT, I-38050 Trento, Italy. Jefferson Lab, Newport News, VA 23606 USA. RP van Dalen, ENE (reprint author), Univ Groningen, Kernfys Versneller Inst, Theory Grp, Zernikelaan 25, NL-9747 AA Groningen, Netherlands. EM vandalen@kvi.nl; dieperink@kvi.nl; tjon@jlab.org NR 28 TC 20 Z9 20 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 EI 1089-490X J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 065807 DI 10.1103/PhysRevC.67.065807 PG 16 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900064 ER PT J AU Zhang, Z Zhu, SJ Hamilton, JH Ramayya, AV Hwang, JK Jiang, Z Xiao, SD Zhang, XQ Kormicki, J Gore, PM Jones, EF Ma, WC Cole, JD Drigert, MW Lee, IY Rasmussen, JO Luo, YX Ginter, TN Folden, C Fallon, P Zielinski, P Gregorich, KE Macchiavelli, AO Donangelo, R Stoyer, MA AF Zhang, Z Zhu, SJ Hamilton, JH Ramayya, AV Hwang, JK Jiang, Z Xiao, SD Zhang, XQ Kormicki, J Gore, PM Jones, EF Ma, WC Cole, JD Drigert, MW Lee, IY Rasmussen, JO Luo, YX Ginter, TN Folden, C Fallon, P Zielinski, P Gregorich, KE Macchiavelli, AO Donangelo, R Stoyer, MA TI Identification of collective bands in neutron-rich Ru-113 SO PHYSICAL REVIEW C LA English DT Article ID NUCLEI AB New levels in the neutron-rich Ru-113 nucleus have been identified by analyzing gamma-gamma-gamma coincidence events following the spontaneous fission of Cf-252 with the Gammasphere detector array. A rotational band going up to 3.6 MeV is identified and is proposed to be built on the intruder nuh(11/2) orbital going up to (31/2)(h) over bar. A few states of a possible signature partner are also observed. C1 Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Mississippi State Univ, Dept Phys, Mississippi State, MS 39762 USA. Idaho Natl Lab, Idaho Falls, ID 83415 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Univ Fed Rio de Janeiro, BR-68528 Rio De Janeiro, Brazil. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. RI Jiang, Zhuo/E-3110-2010; Folden, Charles/F-1033-2015 OI Folden, Charles/0000-0002-2814-3762 NR 10 TC 15 Z9 16 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2003 VL 67 IS 6 AR 064307 DI 10.1103/PhysRevC.67.064307 PG 4 WC Physics, Nuclear SC Physics GA 696GH UT WOS:000183878900021 ER PT J AU Bar, O Rupak, G Shoresh, N AF Bar, O Rupak, G Shoresh, N TI Simulations with different lattice Dirac operators for valence and sea quarks SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PERTURBATION-THEORY; EXACTLY MASSLESS QUARKS; CONTINUUM-LIMIT; QCD; SYMMETRY; FERMIONS AB We discuss simulations with different lattice Dirac operators for sea and valence quarks. A goal of such a "mixed" action approach is to probe deeper the chiral regime of QCD by enabling simulations with light valence quarks. This is achieved by using chiral fermions as valence quarks while computationally inexpensive fermions are used in the sea sector. Specifically, we consider Wilson sea quarks and Ginsparg-Wilson valence quarks. The local Symanzik action for this mixed theory is derived to O(a), and the appropriate low energy chiral effective Lagrangian is constructed, including the leading O(a) contributions. Using this Lagrangian one can calculate expressions for physical observables and determine the Gasser-Leutwyler coefficients by fitting them to the lattice data. C1 MIT, Ctr Theoret Phys, Cambridge, MA 02139 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. RP Bar, O (reprint author), MIT, Ctr Theoret Phys, Cambridge, MA 02139 USA. OI Baer, Oliver/0000-0002-7480-6467 NR 32 TC 57 Z9 58 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 114505 DI 10.1103/PhysRevD.67.114505 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300044 ER PT J AU Betemps, MA Ducati, MBG Machado, MVT Raufeisen, J AF Betemps, MA Ducati, MBG Machado, MVT Raufeisen, J TI Investigating the Drell-Yan transverse momentum distribution in the color dipole approach SO PHYSICAL REVIEW D LA English DT Article ID DYNAMICAL PARTON DISTRIBUTIONS; POMERANCHUK SINGULARITY; AGL EQUATION; PICTURE; PHYSICS; NUCLEUS; PROTON; PAIR AB We study the influence of unitarity corrections on the Drell-Yan transverse momentum distribution within the color dipole approach. These unitarity corrections are implemented through the multiple scattering Glauber-Mueller approach, which is contrasted with a phenomenological saturation model. The process is analyzed for the center of mass energies of the BNL Relativistic Heavy Ion Collider (RHIC, roots=500 GeV) and of the CERN Large Hadron Collider (LHC, roots=14 TeV). In addition, the results are extrapolated down to current energies of proton-proton collisions, where nonasymptotic corrections to the dipole approach are needed. It is also shown that, in the absence of saturation, the dipole approach can be related to the QCD Compton process. C1 Univ Fed Rio Grande do Sul, Inst Fis, BR-91501970 Porto Alegre, RS, Brazil. Univ Fed Pelotas, Inst Fis & Matemat, BR-96010090 Pelotas, RS, Brazil. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Univ Fed Rio Grande do Sul, Inst Fis, Caixa Postal 15051, BR-91501970 Porto Alegre, RS, Brazil. EM mandrebe@if.ufrgs.br; gay@if.ufrgs.br; magnus@if.ufrgs.br; jorgr@lanl.gov RI Machado, Magno/C-2671-2013; Gay Ducati, Maria Beatriz/C-4930-2013 NR 41 TC 18 Z9 18 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 114008 DI 10.1103/PhysRevD.67.114008 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300023 ER PT J AU Carlson, CE Ji, CR AF Carlson, CE Ji, CR TI Angular conditions, relations between the Breit and light-front frames, and subleading power corrections SO PHYSICAL REVIEW D LA English DT Article ID ELECTRON-DEUTERON SCATTERING; PAIR ANNIHILATION PROCESSES; LEPTON-NUCLEON SCATTERING; CURRENT MATRIX-ELEMENTS; INFINITE-MOMENTUM; RELATIVISTIC DYNAMICS; FORM-FACTORS; QUARK-MODEL; PARTICLES; FORMALISM AB We analyze the current matrix elements in the general collinear (Breit) frames and find the relation between the ordinary (or canonical) helicity amplitudes and the light-front helicity amplitudes. Using the conservation of angular momentum, we derive a general angular condition which should be satisfied by the light-front helicity amplitudes for any spin system. In addition, we obtain the light-front parity and time-reversal relations for the light-front helicity amplitudes. Applying these relations to the spin-1 form factor analysis, we note that the general angular condition relating the five helicity amplitudes is reduced to the usual angular condition relating the four helicity amplitudes due to the light-front time-reversal condition. We make some comments on the consequences of the angular condition for the analysis of the high-Q(2) deuteron electromagnetic form factors, and we further apply the general angular condition to the electromagnetic transition between spin-1/2 and spin-3/2 systems and find a relation useful for the analysis of the N-Delta transition form factors. We also discuss the scaling law and the subleading power corrections in the Breit and light-front frames. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Coll William & Mary, Nucl & Particle Theory Grp, Dept Phys, Williamsburg, VA 23187 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. RP Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 USA. EM carlson@physics.wm.edu; crji@unity.ncsu.edu RI Ji, Chueng/J-2623-2013 NR 44 TC 25 Z9 26 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 116002 DI 10.1103/PhysRevD.67.116002 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300063 ER PT J AU Csaki, C Hubisz, J Kribs, GD Meade, P Terning, J AF Csaki, C Hubisz, J Kribs, GD Meade, P Terning, J TI Big corrections from a little Higgs SO PHYSICAL REVIEW D LA English DT Article ID GAUGE-SYMMETRY BREAKING; COMPOSITE HIGGS; STANDARD MODEL; EXTRA DIMENSIONS; SPACE; MASS; UNIFICATION; PHYSICS; LIMITS; SU(2) AB We calculate the tree-level expressions for the electroweak precision observables in the SU(5)/SO(5) littlest Higgs model. The source for these corrections are the exchange of heavy gauge bosons and a triplet Higgs vacuum expectation value (VEV). Weak isospin violating contributions are present because there is no custodial SU(2) global symmetry. The bulk of these weak isospin violating corrections arise from heavy gauge boson exchange while a smaller contribution comes from the triplet Higgs VEV. A global fit is performed to the experimental data and we find that throughout the parameter space the symmetry breaking scale is bounded by f>4 TeV at 95% C.L. Stronger bounds on f are found for generic choices of the high energy gauge couplings. We find that even in the best case scenario one would need fine-tuning of less than a percent to get a Higgs boson mass as light as 200 GeV. C1 Cornell Univ, Newman Lab Elementary Particle Phys, Ithaca, NY 14853 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Los Alamos Natl Lab, Theory Div T8, Los Alamos, NM 87545 USA. RP Cornell Univ, Newman Lab Elementary Particle Phys, Ithaca, NY 14853 USA. EM csaki@mail.lns.cornell.edu; hubisz@mail.lns.cornell.edu; kribs@physics.wisc.edu; meade@mail.lns.cornell.edu; terning@lanl.gov OI Terning, John/0000-0003-1367-0575 NR 52 TC 250 Z9 250 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 115002 DI 10.1103/PhysRevD.67.115002 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300050 ER PT J AU Hashimoto, S Okamoto, M AF Hashimoto, S Okamoto, M TI Perturbative study of anisotropic lattice actions for heavy quarks SO PHYSICAL REVIEW D LA English DT Article ID WILSON FERMIONS; QCD AB Anisotropic lattice fermion actions are investigated with one-loop perturbative calculations aiming at constructing a formulation for a heavy quark with controlled systematic uncertainties. For heavy-light systems at rest an anisotropic lattice with small temporal lattice spacing a(t) suppresses the discretization error by a power of a(t)m(Q) for a heavy quark of mass m(Q). We discuss the issue of large discretization errors, which scale as a(s)m(Q) with a(s) the spatial lattice spacing. By performing one-loop calculations of the speed-of-light renormalization for several possible lattice actions in the limit of a(t)-->0, we show that one can eliminate the large systematic error on the anisotropic lattice. C1 Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. NR 24 TC 12 Z9 12 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 114503 DI 10.1103/PhysRevD.67.114503 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300042 ER PT J AU Lane, K Mrenna, S AF Lane, K Mrenna, S TI Collider phenomenology of technihadrons in the technicolor straw man model SO PHYSICAL REVIEW D LA English DT Article ID TOPCOLOR-ASSISTED TECHNICOLOR; P(P)OVER-BAR COLLISIONS; CHIRAL HIERARCHIES; SYMMETRY-BREAKING; ROOT-S=1.8 TEV; STANDARD MODEL; SEARCH; PHYSICS; BOSONS; CONDENSATE AB We discuss the phenomenology of the lightest SU(3)(C) singlet and nonsinglet technihadrons in the straw man model of low-scale technicolor (TCSM). The technihadrons are assumed to be those arising in top-color-assisted technicolor models in which top-color is broken by technifermion condensates. We improve upon the description of the color-singlet sector presented in our earlier paper introducing the TCSM [K. Lane, Phys. Rev. D 60, 075007 (1999)]. These improvements are most important for subprocess energies well below the masses of the rho(T) and omega(T) vector technihadrons and, therefore, apply especially to e(+)e(-) colliders such as CERN LEP and a low-energy linear collider. In the color-octet sector, we consider mixing of the gluon, the coloron V-8 from top-color breaking, and four isosinglet color-octet technirho mesons rho(T8). We assume, as expected in walking technicolor, that these rho(T8) decay into (q) over barq, gg, and gpi(T) final states, but not into pi(T)pi(T), where pi(T) is a technipion. All the TCSM production and decay processes discussed here are included in the event generator PYTHIA. We present several simulations appropriate for the Fermilab Tevatron collider, and suggest benchmark model lines for further experimental investigation. C1 Boston Univ, Dept Phys, Boston, MA 02215 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. EM lane@physics.bu.edu; mrenna@fnal.gov NR 75 TC 57 Z9 57 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 115011 DI 10.1103/PhysRevD.67.115011 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300059 ER PT J AU Melnitchouk, W Bilson-Thompson, S Bonnet, FDR Hedditch, JN Lee, FX Leinweber, DB Williams, AG Zanotti, JM Zhang, JB AF Melnitchouk, W Bilson-Thompson, S Bonnet, FDR Hedditch, JN Lee, FX Leinweber, DB Williams, AG Zanotti, JM Zhang, JB TI Excited baryons in lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID CLOUDY BAG MODEL; FERMION ACTION; QUARK-MODEL; HYPERFINE INTERACTIONS; NUCLEON SCATTERING; WILSON FERMIONS; CHIRAL ASPECTS; SPECTRUM; HADRONS; MASSES AB We present the first results for the masses of positive and negative parity excited baryons calculated in lattice QCD using an O(a(2))-improved gluon action and a fat-link irrelevant clover (FLIC) fermion action in which only the irrelevant operators are constructed with APE-smeared links. The results are in agreement with earlier calculations of N-* resonances using improved actions and exhibit a clear mass splitting between the nucleon and its chiral partner. A correlation matrix analysis reveals two low-lying J(P)=1/2(-) states with a small mass splitting. The study of different Lambda interpolating fields suggests a similar splitting between the lowest two Lambda1/2(-) octet states. However, the empirical mass suppression of the Lambda(*)(1405) is not evident in these quenched QCD simulations, suggesting a potentially important role for the meson cloud of the Lambda(*)(1405) and/or a need for more exotic interpolating fields. C1 Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia. Univ Adelaide, Special Res Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. Jefferson Lab, Newport News, VA 23606 USA. George Washington Univ, Dept Phys, Ctr Nucl Studies, Washington, DC 20052 USA. RP Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia. RI Zanotti, James/H-8128-2012; Williams, Anthony/I-6698-2012; Leinweber, Derek/J-6705-2013; OI Zanotti, James/0000-0002-3936-1597; Leinweber, Derek/0000-0002-4745-6027; Lee, Frank/0000-0001-8169-3440; Williams, Anthony/0000-0002-1472-1592 NR 62 TC 80 Z9 80 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 114506 DI 10.1103/PhysRevD.67.114506 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300045 ER PT J AU Mukherjee, A Stratmann, M Vogelsang, W AF Mukherjee, A Stratmann, M Vogelsang, W TI Next-to-leading order QCD corrections to A(TT) for prompt photon production SO PHYSICAL REVIEW D LA English DT Article ID HADRON-HADRON SCATTERING; DRELL-YAN-PROCESS; ODD PARTON DISTRIBUTIONS; LEPTON-PAIR PRODUCTION; TRANSVERSITY DISTRIBUTION; MASS SINGULARITIES; PERTURBATIVE QCD; EVOLUTION; FACTORIZATION; COLLISIONS AB We present a next-to-leading order QCD calculation of the cross section for isolated large-p(T) prompt photon production in collisions of transversely polarized protons. We devise a simple method of dealing with the phase space integrals in dimensional regularization in the presence of the cos(2Phi) azimuthal-angular dependence occurring for transverse polarization. Our results allow us to calculate the double-spin asymmetry A(TT)(gamma) for this process at next-to-leading order accuracy, which may be used at BNL RHIC to measure the transversity parton distributions of the proton. C1 Univ Dortmund, Inst Phys, D-44221 Dortmund, Germany. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Mukherjee, A (reprint author), Univ Dortmund, Inst Phys, D-44221 Dortmund, Germany. NR 62 TC 19 Z9 19 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 114006 DI 10.1103/PhysRevD.67.114006 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300021 ER PT J AU Zetocha, V Schafer, T AF Zetocha, V Schafer, T TI Instanton contribution to scalar charmonium and glueball decays SO PHYSICAL REVIEW D LA English DT Article ID DEEP-INELASTIC SCATTERING; PERTURBATIVE QCD VACUUM; ETA-C; WAVE-FUNCTIONS; HEAVY QUARKS; SU(2) VACUUM; LATTICE; ANNIHILATION; ANOMALIES; BEHAVIOR AB We study instanton contributions to hadronic decays of the scalar glueball, the pseudoscalar charmonium state eta(c), and the scalar charmonium state chi(c). Hadronic decays of the eta(c) are of particular interest. The three main decay channels are K (K) over bar pi, etapipi and eta(')pipi, each with an unusually large branching ratio similar to5%. On the quark level, all three decays correspond to an instanton type vertex ((c) over barc)((s) over bars)((d) over bard)((u) over baru). We show that the total decay rate into three pseudoscalar mesons can be reproduced using an instanton size distribution consistent with phenomenology and lattice results. Instantons correctly reproduce the ratio B(pipieta)/B(pipieta(')) but overpredict the ratio B(K (K) over bar pi)/B[pipieta(eta('))]. We consider the role of scalar resonances and suggest that the decay mechanism can be studied by measuring the angular distribution of decay products. C1 SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Riken BNL Res Ctr, Upton, NY 11973 USA. RP SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. OI Schaefer, Thomas/0000-0002-2297-782X NR 55 TC 2 Z9 2 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2003 VL 67 IS 11 AR 114003 DI 10.1103/PhysRevD.67.114003 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 696YN UT WOS:000183915300018 ER PT J AU Bettencourt, LMA Stephens, GJ AF Bettencourt, LMA Stephens, GJ TI Vortex description of the first-order phase transition in the two-dimensional Abelian-Higgs model SO PHYSICAL REVIEW E LA English DT Article ID NEGATIVE SPECIFIC HEAT; SCALAR FIELD-THEORY; COSMIC STRINGS; GAUGE-THEORIES; SYSTEMS; SUPERCONDUCTORS; THERMODYNAMICS; VORTICES; FILMS AB We use both analytical arguments and detailed numerical evidence to show that the first-order transition in the type-I two-dimensional Abelian-Higgs model is commensurate with the statistical behavior of its vortex fluctuations, which behave as an ensemble of attractive particles. The clustering instabilities of such ensembles are shown to be connected to the process of phase nucleation. Calculations of the vortex equation of state show that the temperature for the onset of clustering is in qualitative agreement with the critical temperature. The vortex description provides a general gauge invariant mesoscopic mechanism for the first-order transition and applies for arbitrary type-I couplings. C1 MIT, Ctr Theoret Phys, Cambridge, MA 02139 USA. Los Alamos Natl Lab, Phys Div P21 MS D454, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, TCNLS, Los Alamos, NM 87545 USA. RP MIT, Ctr Theoret Phys, Bldg 6-316, Cambridge, MA 02139 USA. NR 28 TC 1 Z9 1 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD JUN PY 2003 VL 67 IS 6 AR 066105 DI 10.1103/PhysRevE.67.066105 PN 2 PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 699YN UT WOS:000184085000017 PM 16241302 ER PT J AU Frisch, U Mineev-Weinstein, M AF Frisch, U Mineev-Weinstein, M TI Extension of the pole decomposition for the multidimensional Burgers equation SO PHYSICAL REVIEW E LA English DT Article ID COMPLEX SINGULARITIES; FLAME FRONTS; DYNAMICS; INTERMITTENCY; CONDENSATION; TURBULENCE AB It is shown that the generalizations to more than one space dimension of the pole decomposition for the Burgers equation with finite viscosity nu and no force are of the form u=-2nudel ln P, where the P's are explicitly known algebraic (or trigonometric) polynomials in the space variables with polynomial (or exponential) dependence on time. Such solutions have pole singularities on the complex algebraic varieties. C1 Observ Cote Azur, CNRS, F-06304 Nice 4, France. Los Alamos Natl Lab, Div Theoret, CNLS, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Appl Phys, Grp X7, Los Alamos, NM 87545 USA. RP Frisch, U (reprint author), Observ Cote Azur, CNRS, Boite Postale 4229, F-06304 Nice 4, France. NR 29 TC 3 Z9 3 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD JUN PY 2003 VL 67 IS 6 AR 067301 DI 10.1103/PhysRevE.67.067301 PN 2 PG 3 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 699YN UT WOS:000184085000107 ER PT J AU Krommes, JA Rath, S AF Krommes, JA Rath, S TI Monte Carlo sampling of negative-temperature plasma states SO PHYSICAL REVIEW E LA English DT Article ID DRIFT-WAVE TURBULENCE; 2-DIMENSIONAL TURBULENCE; PARTICLE-SIMULATION; GYROKINETIC PLASMA; DELTA-F; DYNAMICS; FLOW AB A Monte Carlo procedure is used to generate N-particle configurations compatible with two-temperature canonical equilibria in two dimensions, with particular attention to nonlinear plasma gyrokinetics. An unusual feature of the problem is the importance of a nontrivial probability density function P(0)(phi), the probability of realizing a set phi of Fourier amplitudes associated with an ensemble of uniformly distributed, independent particles. This quantity arises because the equilibrium distribution is specified in terms of phi, whereas the sampling procedure naturally produces particle states Gamma; phi and Gamma are related via a gyrokinetic Poisson equation, highly nonlinear in its dependence on Gamma. Expansion and asymptotic methods are used to calculate P(0)(phi) analytically; excellent agreement is found between the large-N asymptotic result and a direct numerical calculation. The algorithm is tested by successfully generating a variety of states of both positive and negative temperature, including ones in which either the longest- or shortest-wavelength modes are excited to relatively large amplitudes. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Krommes, JA (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM krommes@princeton.edu NR 48 TC 0 Z9 0 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD JUN PY 2003 VL 67 IS 6 AR 066402 DI 10.1103/PhysRevE.67.066402 PN 2 PG 28 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 699YN UT WOS:000184085000069 ER PT J AU Murokh, A Agustsson, R Babzien, M Ben-Zvi, I Bertolini, L van Bibber, K Carr, R Cornacchia, M Frigola, P Hill, J Johnson, E Klaisner, L Le Sage, G Libkind, M Malone, R Nuhn, HD Pellegrini, C Reiche, S Rakowsky, G Rosenzweig, J Ruland, R Skaritka, J Toor, A Tremaine, A Wang, X Yakimenko, V AF Murokh, A Agustsson, R Babzien, M Ben-Zvi, I Bertolini, L van Bibber, K Carr, R Cornacchia, M Frigola, P Hill, J Johnson, E Klaisner, L Le Sage, G Libkind, M Malone, R Nuhn, HD Pellegrini, C Reiche, S Rakowsky, G Rosenzweig, J Ruland, R Skaritka, J Toor, A Tremaine, A Wang, X Yakimenko, V TI Properties of the ultrashort gain length, self-amplified spontaneous emission free-electron laser in the linear regime and saturation SO PHYSICAL REVIEW E LA English DT Article ID FLUCTUATIONS; RADIATION; NM AB VISA (Visible to Infrared SASE Amplifier) is a high-gain self-amplified spontaneous emission (SASE) free-electron laser (FEL), which achieved saturation at 840 nm within a single-pass 4-m undulator. The experiment was performed at the Accelerator Test Facility at BNL, using a high brightness 70-MeV electron beam. A gain length shorter than 18 cm has been obtained, yielding a total gain of 2x10(8) at saturation. The FEL performance, including the spectral, angular, and statistical properties of SASE radiation, has been characterized for different electron beam conditions. Results are compared to the three-dimensional SASE FEL theory and start-to-end numerical simulations of the entire injector, transport, and FEL systems. An agreement between simulations and experimental results has been obtained at an unprecedented level of detail. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Univ Calif Los Angeles, Dept Phys & Astron, 405 Hilgard Ave, Los Angeles, CA 90095 USA. NR 42 TC 21 Z9 21 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD JUN PY 2003 VL 67 IS 6 AR 066501 DI 10.1103/PhysRevE.67.066501 PN 2 PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 699YN UT WOS:000184085000076 PM 16241361 ER PT J AU Abell, DT McIntosh, E Schmidt, F AF Abell, DT McIntosh, E Schmidt, F TI Fast symplectic map tracking for the CERN Large Hadron Collider SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article AB Tracking simulations remain the essential tool for evaluating how multipolar imperfections in ring magnets restrict the domain of stable phase-space motion. In the Large Hadron Collider (LHC) at CERN, particles circulate at the injection energy, when multipole errors are most significant, for more than 10(7) turns, but systematic tracking studies are limited to a small fraction of this total time - even on modern computers. A considerable speedup is expected by replacing element-by-element tracking with the use of a symplectified one-turn map. We have applied this method to the realistic LHC lattice, version 6, and report here our results for various map orders, with special emphasis on precision and speed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. CERN, CH-1211 Geneva 23, Switzerland. RP Abell, DT (reprint author), Tech X Corp, 5541 Cent Ave,Suite 135, Boulder, CO 80301 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD JUN PY 2003 VL 6 IS 6 AR 064001 DI 10.1103/PhysRevSTAB.6.064001 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 702BH UT WOS:000184204400006 ER PT J AU Fischer, W AF Fischer, W TI Robust linear coupling correction with N-turn maps SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article AB The linear one-turn map of a storage ring contains coupling information on which a correction algorithm can be based. In principal, the one-turn matrix can be fitted from turn-by-turn data of beam position monitors. However, the signal-to-noise ratio of the coupling information can be greatly enhanced by fitting maps for larger turn numbers N. Furthermore, by using a number of beam position monitors in a region with only small coupling sources, the determination of the N-turn map can be made robust against failures of individual beam position monitors, and the signal-to-noise ratio of the coupling information is further enhanced. With the so obtained N-turn maps an automated global coupling correction is possible without the need for a tune change. This is demonstrated for the Brookhaven Relativistic Heavy Ion Collider where the implementation of the algorithm allows a global coupling correction within a few seconds at injection. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Fischer, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 23 TC 9 Z9 9 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD JUN PY 2003 VL 6 IS 6 AR 062801 DI 10.1103/PhysRevSTAB.6.062801 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 702BH UT WOS:000184204400004 ER PT J AU Heifets, S Stupakov, G AF Heifets, S Stupakov, G TI Single-mode coherent synchrotron radiation instability SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID SATURATION AB The microwave instability driven by the coherent synchrotron radiation (CSR) has been previously studied [S. Heifets and G. V. Stupakov, Phys. Rev. ST Accel. Beams 5, 054402 (2002)] neglecting effect of the shielding caused by the finite beam pipe aperture. In practice, the unstable mode can be close to the shielding threshold where the spectrum of the radiation in a toroidal beam pipe is discrete. In this paper, the CSR instability is studied in the case when it is driven by a single synchronous mode. A system of equations for the beam-wave interaction is derived and its similarity to the 1D free-electron laser theory is demonstrated. In the linear regime, the growth rate of the instability is obtained and a transition to the case of continuous spectrum is discussed. The nonlinear evolution of the single-mode instability, both with and without synchrotron damping and quantum diffusion, is also studied. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Heifets, S (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 19 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD JUN PY 2003 VL 6 IS 6 AR 064401 DI 10.1103/PhysRevSTAB.6.064401 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 702BH UT WOS:000184204400007 ER PT J AU Tenenbaum, P Irwin, J Raubenheimer, TO AF Tenenbaum, P Irwin, J Raubenheimer, TO TI Beam dynamics of the interaction region solenoid in a linear collider due to a crossing angle SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article AB Future linear colliders may require a nonzero crossing angle between the two beams at the interaction point (IP). This requirement in turn implies that the beams will pass through the strong interaction region solenoid with an angle, and thus that the component of the solenoidal field perpendicular to the beam trajectory is nonzero. The interaction of the beam and the solenoidal field in the presence of a crossing angle will cause optical effects not observed for beams passing through the solenoid on axis; these effects include dispersion, deflection of the beam, and synchrotron radiation effects. For a purely solenoidal field, the optical effects which are relevant to luminosity exactly cancel at the IP when the influence of the solenoid's fringe field is taken into account. Beam size growth due to synchrotron radiation in the solenoid is proportional to the fifth power of the product of the solenoidal field, the length of the solenoid, and the crossing angle. Examples based on proposed linear collider detector solenoid configurations are presented. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Tenenbaum, P (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD JUN PY 2003 VL 6 IS 6 AR 061001 DI 10.1103/PhysRevSTAB.6.061001 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 702BH UT WOS:000184204400001 ER PT J AU Park, B Bylaska, E Corrales, LR AF Park, B Bylaska, E Corrales, LR TI Energy dependence of vitreous B2O3 on boroxol ring concentration SO PHYSICS AND CHEMISTRY OF GLASSES LA English DT Article; Proceedings Paper CT 4th International Conference on Borates Glasses, Crystals and Melts CY 2002 CL CEDAR RAPIDS, IA ID MOLECULAR-DYNAMICS SIMULATIONS; NUCLEAR-MAGNETIC-RESONANCE; BORATE GLASSES; NEUTRON-DIFFRACTION; OXIDE; PSEUDOPOTENTIALS; SCATTERING; POTENTIALS; TRIOXIDE; MODEL AB Total energy calculations of borate glass samples with fixed fractions of boroxol rings are carried out using density functional theory. In this work, the method of preparation of the samples is described and preliminary results are presented. The calculations suggest that initial distributions of boroxol ring structures may strongly affect results. Additionally, ab initio cluster calculations are used to determine the extent of pi-bonding. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Corrales, LR (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. EM rene.corrales@pnl.gov NR 42 TC 1 Z9 1 U1 0 U2 0 PU SOC GLASS TECHNOLOGY PI SHEFFIELD PA 9 CHURCHILL WAY, SHEFFIELD S35 2PY, CHAPELTOWN, ENGLAND SN 0031-9090 J9 PHYS CHEM GLASSES JI Phys. Chem. Glasses PD JUN PY 2003 VL 44 IS 3 BP 174 EP 177 PG 4 WC Chemistry, Physical; Materials Science, Ceramics SC Chemistry; Materials Science GA 724HV UT WOS:000185482900002 ER PT J AU Gibbs, GV Rosso, KM Cox, DF Boisen, MB AF Gibbs, GV Rosso, KM Cox, DF Boisen, MB TI A physical basis for Pauling's definition of bond strength SO PHYSICS AND CHEMISTRY OF MINERALS LA English DT Article DE bond strength; bond number ID LENGTH; CRYSTALS AB The average strength, s, of the bonded interactions comprising a cation containing oxide anion coordination polyhedron and the value of the electron density, rho(r(c)), at the bond-critical points are inversely correlated with bond length. In each case, the observed bond lengths, R, were modeled with power-law expressions defined in terms of s/r and rho(r(c))/r, respectively, where r is the Periodic Table row number of the cation involved in the bonded interaction. On the basis of the close connection between bond strength and the value of the electron density at the bond-critical point, we conclude that bond strength is a direct measure of bond type; the greater its value, the greater the localization of electron density in the binding region and the greater the shared-electron covalent character of the bonded interaction. C1 Virginia Tech, Dept Geol Sci, Blacksburg, VA 24061 USA. Pacific N W Natl Labs, Environm Mol Sci Lab, Richland, WA USA. Virginia Tech, Dept Chem Engn, Blacksburg, VA 24061 USA. Univ Idaho, Dept Math, Moscow, ID USA. RP Gibbs, GV (reprint author), Care of Spackman M, Univ New England, Dept Chem, Armidale, NSW 2351, Australia. NR 16 TC 18 Z9 20 U1 1 U2 9 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0342-1791 J9 PHYS CHEM MINER JI Phys. Chem. Miner. PD JUN PY 2003 VL 30 IS 5 BP 317 EP 320 DI 10.1007/s00269-003-0316-4 PG 4 WC Materials Science, Multidisciplinary; Mineralogy SC Materials Science; Mineralogy GA 691BF UT WOS:000183584400008 ER PT J AU Itkis, MG Beghini, S Bogatchev, AA Corradi, L Dorvaux, O Gadea, A Giardina, G Goverdovski, AA Hanappe, F Itkis, IM Jandel, M Kliman, J Kniajeva, GN Kondratiev, NA Korzyukov, IV Kozulin, EM Krupa, L Latina, L Materna, T Montagnoli, G Moody, KJ Oganessian, YT Pokrovsky, IV Ponomarenko, VA Prokhorova, EV Rowley, N Rusanov, AY Scarlassara, F Stefanini, AM Stuttge, L Szilner, S Trotta, M Vinodkumar, AM AF Itkis, MG Beghini, S Bogatchev, AA Corradi, L Dorvaux, O Gadea, A Giardina, G Goverdovski, AA Hanappe, F Itkis, IM Jandel, M Kliman, J Kniajeva, GN Kondratiev, NA Korzyukov, IV Kozulin, EM Krupa, L Latina, L Materna, T Montagnoli, G Moody, KJ Oganessian, YT Pokrovsky, IV Ponomarenko, VA Prokhorova, EV Rowley, N Rusanov, AY Scarlassara, F Stefanini, AM Stuttge, L Szilner, S Trotta, M Vinodkumar, AM TI Fusion-fission of heavy and superheavy nuclei SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 7th International School Seminar on Heave-Ion Physics CY MAY 24-JUN 01, 2002 CL DUBNA, RUSSIA SP Flerov Lab Nucl React, Joint Inst Nucl Res AB The process of fusion-fission of heavy and superheavy nuclei (SHE) with Z = 82-122 formed in the reactions with Ca-48 and Fe-58 ions at energies near and below the Coulomb barrier has been studied. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR) and at the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL) using the time-of-flight spectrometer of fission fragments CORSET and the neutron multidetector DEMON. As a result of the experiments, mass and energy distributions (MED) of fission fragments; fission, quasifission, and evaporation residue cross sections; and multiplicities of neutrons and gamma-quanta and their dependences on the mechanism of formation and decay of compound systems have been studied. (C) 2003 MAIK "Nauka/lnterperiodica". C1 Joint Inst Nucl Res, Flerov Lab Nucl React, Dubna 141980, Moscow Oblast, Russia. Univ Padua, Dipartimento Fis, I-35100 Padua, Italy. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. Inst Rech Subatom, Strasbourg, France. Univ Messina, Dipartimento Fis, Messina, Italy. Inst Phys & Power Engn, Obninsk, Russia. Free Univ Brussels, Brussels, Belgium. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Natl Nucl Ctr, Inst Nucl Phys, Almaty, Kazakhstan. RP Itkis, MG (reprint author), Joint Inst Nucl Res, Flerov Lab Nucl React, Dubna 141980, Moscow Oblast, Russia. RI Attukalathil, Vinodkumar/A-7441-2009; Gadea, Andres/L-8529-2014; OI Attukalathil, Vinodkumar/0000-0002-8204-7800; Gadea, Andres/0000-0002-4233-1970; Scarlassara, Fernando/0000-0002-4663-8216 NR 11 TC 6 Z9 6 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD JUN PY 2003 VL 66 IS 6 BP 1118 EP 1124 DI 10.1134/1.1586425 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 705PE UT WOS:000184402800016 ER PT J AU Schmitt, RP Botting, T Chubarian, GG Wolf, KL Hurst, BJ Jabs, H Hamelin, M Bacak, A Oganessian, YT Itkis, MG Kozulin, EM Kondratiev, NA Salamatin, VS Pokrovsky, IV Hanappe, F Brennand, ED Huck, A Stuttge, L Liatard, E Beene, J Varner, R Halbert, M Gan, N AF Schmitt, RP Botting, T Chubarian, GG Wolf, KL Hurst, BJ Jabs, H Hamelin, M Bacak, A Oganessian, YT Itkis, MG Kozulin, EM Kondratiev, NA Salamatin, VS Pokrovsky, IV Hanappe, F Brennand, ED Huck, A Stuttge, L Liatard, E Beene, J Varner, R Halbert, M Gan, N TI Probing fission time scales with neutrons and GDR gamma rays SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 7th International School Seminar on Heave-Ion Physics CY MAY 24-JUN 01, 2002 CL DUBNA, RUSSIA SP Flerov Lab Nucl React, Joint Inst Nucl Res AB The time scales for nuclear fission have been explored using both pre- and postfission neutrons and GDR gamma rays. Four systems were investigated: 133-MeV O-16 + Yb-176 and Pb-208 and 104-MeV He-4 + Os-188 and Bi-209. Fission fragments were measured in coincidence with PPACs. The neutrons were detected using eight detectors from the DEMON array, while gamma rays were measured using the US BaF2 array. The pre- and postfission gamma rays were determined using moving source fits parallel and perpendicular to the fission fragment emission directions. The time scales for fission for the neutrons were determined using the neutron clock technique. The gamma-ray data were fitted using a statistical model calculation based on the code CASCADE. The results of the fits from both data types were used to extract nuclear friction coefficients, gamma, and fission time scales. The gamma values ranged from 7 to 20, while the fission times were (31-105) x 10(-21) s. (C) 2003 MAIK "Nauka/Interperiodica". C1 Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Joint Inst Nucl Res, Flerov Lab Nucl React, Dubna 141980, Moscow Oblast, Russia. Free Univ Brussels, Brussels, Belgium. CRN, Strasbourg, France. ISN, Grenoble, France. ORNL, Oak Ridge, TN USA. RP Schmitt, RP (reprint author), Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. RI Chubarian, Grigor/H-2519-2014 NR 10 TC 5 Z9 5 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD JUN PY 2003 VL 66 IS 6 BP 1163 EP 1167 DI 10.1134/1.1586431 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 705PE UT WOS:000184402800022 ER PT J AU Wunsch, S AF Wunsch, S TI Stochastic simulations of buoyancy-reversal experiments SO PHYSICS OF FLUIDS LA English DT Article ID TOP ENTRAINMENT INSTABILITY; CLOUD; TURBULENCE; DWARFS; MODEL AB Buoyancy reversal occurs when the mixing of two fluids, initially stably stratified, produces a mixture which is more dense than either pure fluid. The resulting instability generates turbulent mixing, and may play an important role in geophysical and astrophysical flows. In this work, a stochastic one- dimensional model is used to simulate these systems. Model validation is accomplished using experimental comparisons. Scalings inferred from the model simulations are used to suggest extrapolations from experimental results to natural systems. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Wunsch, S (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 22 TC 13 Z9 13 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUN PY 2003 VL 15 IS 6 BP 1442 EP 1456 DI 10.1063/1.1572160 PG 15 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 677FB UT WOS:000182795300010 ER PT J AU Brady, V Concus, P Finn, R AF Brady, V Concus, P Finn, R TI Capillary rise in nesting cylinders SO PHYSICS OF FLUIDS LA English DT Article ID SURFACES AB We investigate computationally recent results concerning the question of whether liquid necessarily rises higher in a capillary tube of smaller section, when tubes are placed vertically in an infinite reservoir. The numerical results corroborate for a particular example a striking discontinuous behavior that was predicted mathematically. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Stanford Univ, Dept Math, Stanford, CA 94305 USA. RP Brady, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 10 TC 3 Z9 3 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 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUN PY 2003 VL 15 IS 6 BP 1545 EP 1551 DI 10.1063/1.1566449 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 677FB UT WOS:000182795300018 ER PT J AU Belova, EV Davidson, RC Ji, HT Yamada, M AF Belova, EV Davidson, RC Ji, HT Yamada, M TI Kinetic effects on the stability properties of field-reversed configurations. 1. Linear stability SO PHYSICS OF PLASMAS LA English DT Article ID INTERNAL TILT MODE; GYROVISCOUS STABILITY; PLASMA AB New computational results are presented which advance the understanding of the stability properties of the field-reversed configuration (FRC). The results of hybrid and two-fluid [Hall-MHD (magnetohydrodynamic)] simulations of prolate FRCs are presented. The n=1 tilt instability mechanism and growth rate reduction mechanisms are investigated in detail, including resonant particle effects, finite Larmor radius and Hall stabilization, and profile effects. It is shown that the Hall effect determines the mode rotation and the change in the linear mode structure in the kinetic regime; however, the reduction in the growth rate is mostly due to finite Larmor radius effects. Resonant wave-particle interactions are studied as a function of (a) elongation, (b) the kinetic parameter S*, which is proportional to the ratio of the separatrix radius to the thermal ion Larmor radius, and (c) the separatrix shape. It is demonstrated that, contrary to the usually assumed stochasticity of the ion orbits in the FRC, a large fraction of the orbits are regular in long configurations when S* is small. A stochasticity condition is found, and a scaling with the S* parameter is presented. Resonant particle effects are shown to maintain the instability in the large gyroradius regime regardless of the separatrix shape. (C) 2003 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Belova, EV (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 23 TC 21 Z9 21 U1 4 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2361 EP 2371 DI 10.1063/1.1568118 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500019 ER PT J AU Egedal, J Redi, MH Darrow, DS Kaye, SM AF Egedal, J Redi, MH Darrow, DS Kaye, SM TI Efficient evaluation of beam ion confinement in spherical tokamaks SO PHYSICS OF PLASMAS LA English DT Article ID DIFFUSION; TOPOLOGY; ORBITS; PLASMA AB New efficient methods are developed for the determination of the confined fraction of beam ions in standard and spherical tokamaks. The particle motion is described in the guiding center approximation and finite Larmor radius effects are included in the determination of the prompt orbit losses. A new code, CONBEAM, utilizes these methods and provides rapid evaluation of the beam confinement. Losses due to nonadiabatic changes in the magnetic moment are also evaluated. Due to the conservation of the canonical angular momentum, it is shown that changes in magnetic moment will not lead to a significant reduction in the confinement of co-injected beam ions. (C) 2003 American Institute of Physics. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Egedal, J (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 17 TC 8 Z9 8 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2372 EP 2381 DI 10.1063/1.1569490 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500020 ER PT J AU Furno, I Weisen, H AF Furno, I Weisen, H CA TCV Team TI Observation of inward and outward particle convection in the core of electron cyclotron heated and current driven plasmas in the Tokamak a Configuration Variable SO PHYSICS OF PLASMAS LA English DT Article ID TCV TOKAMAK; CONFINEMENT; TRANSPORT; PINCH; SHAPE; ECCD; ECH AB In the Tokamak a Configuration Variable [F. Hofmann, J.B. Lister, M. Anton et al., Plasma Phys. Controlled Fusion 36, B277 (1994)], inward or outward convection in the core of electron cyclotron heated and current driven plasmas is observed, depending on discharge conditions. In sawtoothing discharges with central electron cyclotron heating, outward convection is observed when a quasicontinuous m=1 kink mode is present, resulting in inverted sawteeth on the central electron density, while in the absence thereof, inward convection between successive sawtooth crashes leads to "normal" sawteeth. The occurrence of a kink mode depends sensitively on plasma triangularity. When sawteeth are stabilized with central co- or counterelectron cyclotron current drive, stationary hollow electron density profiles are observed in the presence of m=1 modes, while peaked or flat profiles are observed in magnetohydrodynamic quiescent discharges. The observation of peaked density profiles in fully electron cyclotron driven plasmas demonstrates that pinch processes other than the Ware pinch must be responsible for these phenomena. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EPFL, Assoc Euratom Confederat Suisse, Ctr Rech Phys Plasmas, CH-1015 Lausanne, Switzerland. RP Furno, I (reprint author), Los Alamos Natl Lab, MS E526, Los Alamos, NM 87545 USA. NR 32 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2422 EP 2428 DI 10.1063/1.1576389 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500025 ER PT J AU Turner, RE Amendt, PA Landen, OL Suter, LJ Wallace, RJ Hammel, BA AF Turner, RE Amendt, PA Landen, OL Suter, LJ Wallace, RJ Hammel, BA TI Role of laser beam geometry in improving implosion symmetry and performance for indirect-drive inertial confinement fusion SO PHYSICS OF PLASMAS LA English DT Article ID NATIONAL IGNITION FACILITY; TARGETS; OMEGA; NOVA; SIMULATIONS; ASYMMETRY; HOHLRAUMS; DENSITY; SYSTEM; CONES AB The role of a high-Z radiation cavity or hohlraum in inertial confinement fusion is to convert laser energy into soft x-ray energy, in a highly spatially symmetric manner, so that a centrally located capsule containing deuterium and tritium can be uniformly imploded. In practice, however, the asymmetry introduced by the small number of high intensity laser beams can introduce significant perturbations in the drive uniformity. Experiments performed on Nova (10 beams) [J.T. Hunt and D.R. Speck, Opt. Eng. 28, 461 (1989)] and Omega (using 40 beams) [J.M. Sources, R. L. McCrory, C.P. Verdon et al., Phys. Plasmas 3, 2108 (1996)] demonstrate a significant improvement in symmetry and target performance from a fourfold increase in the number of laser beams. 0 2003 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Turner, RE (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 20 TC 10 Z9 13 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2429 EP 2432 DI 10.1063/1.1576762 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500026 ER PT J AU Glenzer, SH Gregori, G Rogers, FJ Froula, DH Pollaine, SW Wallace, RS Landen, OL AF Glenzer, SH Gregori, G Rogers, FJ Froula, DH Pollaine, SW Wallace, RS Landen, OL TI X-ray scattering from solid density plasmas SO PHYSICS OF PLASMAS LA English DT Article ID INERTIAL-CONFINEMENT FUSION; THOMSON SCATTERING; DIFFRACTION; ELECTRONS; IGNITION; LIQUIDS AB Measurements of the microscopic properties of dense matter have been demonstrated by applying spectrally resolved multi-keV x-ray scattering. The scattering spectra from solid density beryllium show the inelastic Compton-down shifted feature that is spectrally broadened when heating the solid density plasmas isochorically and homogeneously to temperatures of several times the Fermi energy. The spectral shape of the inelastic scattering component provides an accurate measurement of the temperature, and the intensity ratio of inelastic to elastic scattering measures the ionization balance. These measurements extend the powerful technique of Thomson scattering [S. H. Glenzer et al., Phys. Plasmas 7, 2149 (1999)] to the x-ray regime for independent measurements of the plasma parameters of solid density and super dense laboratory plasmas. This new technique has wide applications to investigate the previously inaccessible regimes of dense matter, from Fermi degenerate, to strongly coupled, to high temperature ideal gas plasmas.; (C) 2003 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Glenzer, SH (reprint author), Lawrence Livermore Natl Lab, L-399,POB 808, Livermore, CA 94550 USA. NR 36 TC 55 Z9 56 U1 1 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2433 EP 2441 DI 10.1063/1.1570420 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500027 ER PT J AU Welch, DR Genoni, TC Rose, DV Oliver, BV Clark, RE Olson, CL Yu, SS AF Welch, DR Genoni, TC Rose, DV Oliver, BV Clark, RE Olson, CL Yu, SS TI Assisted-pinched transport of heavy-ion beams in a fusion chamber SO PHYSICS OF PLASMAS LA English DT Article ID PLASMA-CHANNEL; SIMULATIONS; TARGET; GAS AB In heavy-ion inertial confinement fusion, ion beams are transported several meters through the reactor chamber to the target. This standoff distance mitigates damage to the final focus magnets and chamber walls from the target explosion. A promising transport scheme makes use of a preformed discharge channel to confine and guide the beams. In this assisted-pinched transport scheme, many individual beams are merged into two high-current beams for two-sided illumination of the fusion target. The beams are combined and focused outside the chamber before propagating at small radius in the discharge channel to the target. A large beam divergence can be contained by the strong magnetic field resulting from the roughly 50-kA discharge current. Using a hybrid particle-in-cell simulation code, we examine the dynamics of heavy-ion inertial confinement fusion driver-scale beams in this transport mode. Results from detailed two-dimensional simulations of assisted-pinched transport in roughly 1-Torr Xe suggest that the Xe plasma becomes sufficiently conductive to limit self-field effects and achieve good transport efficiency. Coupling to a published target design is calculated. In addition, results from a semianalytic theory for resistive hose growth are presented that explain three-dimensional simulation results. (C) 2003 American Institute Of Physics. C1 Mission Res Corp, Albuquerque, NM 87110 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Welch, DR (reprint author), Mission Res Corp, 5001 Indian Sch Rd NE, Albuquerque, NM 87110 USA. NR 30 TC 8 Z9 8 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2442 EP 2448 DI 10.1063/1.1570421 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500028 ER PT J AU Sharp, WM Callahan, DA Tabak, M Yu, SS Peterson, PF AF Sharp, WM Callahan, DA Tabak, M Yu, SS Peterson, PF TI Chamber transport of "foot" pulses for heavy-ion fusion SO PHYSICS OF PLASMAS LA English DT Article ID INERTIAL CONFINEMENT FUSION; TARGET; DESIGN; BEAMS AB Indirect-drive targets for heavy-ion fusion must initially be heated by "foot" pulses that precede the main heating pulses by tens of nanoseconds. These pulses typically have a lower energy and perveance than the main pulses, and the fusion-chamber environment is different from that seen by later pulses. The preliminary particle-in-cell simulations of foot pulses here examine the sensitivity of the beam focusing to ion-beam perveance, background-gas density, and pre-neutralization by a plasma near the chamber entry port. (C) 2003 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Sharp, WM (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 20 TC 6 Z9 7 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2457 EP 2467 DI 10.1063/1.1570826 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500030 ER PT J AU Solodov, AA Malkin, VM Fisch, NJ AF Solodov, AA Malkin, VM Fisch, NJ TI Random density inhomogeneities and focusability of the output pulses for plasma-based powerful backward Raman amplifiers SO PHYSICS OF PLASMAS LA English DT Article ID SHORT LASER-PULSES AB Random plasma density inhomogeneities may defocus the output pulses of powerful backward Raman amplifiers (BRA). Because of ultrahigh intensities of even nonfocused BRA outputs, such distortions, if occur, are then difficult to correct. A simple expression is derived for the largest BRA length for which the output pulse focusability is not yet spoiled. Interestingly, this limitation does not depend on the pump laser intensity. A useful effect of plasma inhomogeneities that might help to suppress premature pump backscattering by thermal noise is also pointed out. (C) 2003 American Institute of Physics. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Solodov, AA (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM asolodov@pppl.gov NR 10 TC 26 Z9 26 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2540 EP 2544 DI 10.1063/1.1576761 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500039 ER PT J AU Startsev, EA McKinstrie, CJ AF Startsev, EA McKinstrie, CJ TI Particle-in-cell simulations of ponderomotive particle acceleration in a plasma SO PHYSICS OF PLASMAS LA English DT Article ID LASER-PULSES; INTENSE AB In previous publications [C.J. McKinstrie and E.A. Startsev, Phys. Rev. E 54, R1070 (1996); 56, 2130 (1997)] the ponderomotive acceleration of electrons by an idealized (one-dimensional) circularly polarized laser pulse in a plasma was studied analytically. Acceleration gradients of order 100 GeV/m were predicted. To verify the predictions of the theoretical model, a two-dimensional relativistic particle-in-cell code was developed. Simulations of the interaction of a preaccelerated. electron bunch with a realistic (two-dimensional) laser pulse in a plasma are presented and analyzed. The simulation results validate the theoretical model and show that significant ponderomotive acceleration is possible. (C) 2003 American Institute of Physics. C1 Univ Rochester, Dept Mech Engn, Rochester, NY 14627 USA. Univ Rochester, Laser Energet Lab, Rochester, NY USA. RP Startsev, EA (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI McKinstrie, Colin/L-7879-2013 NR 19 TC 18 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2552 EP 2558 DI 10.1063/1.1576760 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500041 ER PT J AU Dunaevsky, A Raitses, Y Fisch, NJ AF Dunaevsky, A Raitses, Y Fisch, NJ TI Secondary electron emission from dielectric materials of a Hall thruster with segmented electrodes SO PHYSICS OF PLASMAS LA English DT Article ID INSULATORS; YIELD; FLOW AB The discharge parameters in Hall thrusters depend strongly on the yield of secondary electron emission from channel walls. Comparative measurements of the yield of secondary electron emission at low energies of primary electrons were performed for several dielectric materials used in Hall thrusters with segmented electrodes. The measurements showed that at low energies of primary electrons the actual energetic dependencies of the total yield of secondary electron emission could differ from fits, which are usually used in theoretical models. The observed differences might be caused by electron backscattering, which is dominant at lower energies and depends strongly on surface properties. Fits based on power or linear laws are relevant at higher energies of primary electrons, where the bulk material properties play a decisive role. (C) 2003 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Dunaevsky, A (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 29 TC 63 Z9 64 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2574 EP 2577 DI 10.1063/1.1568344 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500044 ER PT J AU Cohen, SA Siefert, NS Stange, S Boivin, RF Scime, EE Levinton, FM AF Cohen, SA Siefert, NS Stange, S Boivin, RF Scime, EE Levinton, FM TI Ion acceleration in plasmas emerging from a helicon-heated magnetic-mirror device SO PHYSICS OF PLASMAS LA English DT Article ID EXPANSION; FIELD AB Using laser-induced fluorescence, measurements have been made of metastable argon-ion, Ar+*(3d(4)F(7/2)), velocity distributions on the major axis of an axisymmetric magnetic-mirror device whose plasma is sustained by helicon wave absorption. Within the mirror, these ions have sub-eV temperature and, at most, a subthermal axial drift. In the region outside the mirror coils, conditions are found where these ions have a field-parallel velocity above the acoustic speed, to an axial energy of similar to30 eV, while the field-parallel ion temperature remains low. The supersonic Ar+*(3d(4)F(7/2)) are accelerated to one-third of their final energy within a short region in the plasma column, less than or equal to1 cm, and continue to accelerate over the next 5 cm. Neutral-gas density strongly affects the supersonic Ar+*(3d(4)F(7/2)) density. (C) 2003 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. W Virginia Univ, Morgantown, WV 26506 USA. NOVA Photon Inc, Princeton, NJ 08540 USA. RP Cohen, SA (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 30 TC 93 Z9 93 U1 2 U2 23 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 2003 VL 10 IS 6 BP 2593 EP 2598 DI 10.1063/1.1568342 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 686HX UT WOS:000183316500047 ER PT J AU Bari, RA AF Bari, RA TI Continuous neutron source needed SO PHYSICS TODAY LA English DT Letter C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bari, RA (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUN PY 2003 VL 56 IS 6 BP 16 EP 16 DI 10.1063/1.1595041 PG 1 WC Physics, Multidisciplinary SC Physics GA 684MA UT WOS:000183210100006 ER PT J AU Trilling, G AF Trilling, G TI Co-authors are responsible too SO PHYSICS WORLD LA English DT Article C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Trilling, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD JUN PY 2003 VL 16 IS 6 BP 16 EP 16 PG 1 WC Physics, Multidisciplinary SC Physics GA 689MN UT WOS:000183497200016 ER PT J AU Crease, RP AF Crease, RP TI Numbers count in all amounts SO PHYSICS WORLD LA English DT Editorial Material C1 SUNY Stony Brook, Dept Philosophy, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Crease, RP (reprint author), SUNY Stony Brook, Dept Philosophy, Stony Brook, NY 11794 USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD JUN PY 2003 VL 16 IS 6 BP 17 EP 17 PG 1 WC Physics, Multidisciplinary SC Physics GA 689MN UT WOS:000183497200017 ER PT J AU Schaefer, T AF Schaefer, T TI The RHIC gold rush SO PHYSICS WORLD LA English DT Article C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Brookhaven Natl Lab, Riken BNL Res Ctr, Upton, NY 11973 USA. RP Schaefer, T (reprint author), N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD JUN PY 2003 VL 16 IS 6 BP 31 EP 35 PG 5 WC Physics, Multidisciplinary SC Physics GA 689MN UT WOS:000183497200030 ER PT J AU Feil, H Feil, WS Detter, JC Purcell, AH Lindow, SE AF Feil, H Feil, WS Detter, JC Purcell, AH Lindow, SE TI Site-directed disruption of the fimA and fimF fimbrial genes of Xylella fastidiosa SO PHYTOPATHOLOGY LA English DT Article ID KLEBSIELLA-PNEUMONIAE; TYPE-3 FIMBRIAE; ELECTROPORATION; TRANSFORMATION; RECOMBINATION; MUTAGENESIS; DEFICIENT; GRAPEVINE; BACTERIUM; SEQUENCE AB Xylella fastidiosa causes Pierce's disease. a serious disease of grape, citrus variegated chlorosis. almond and oleander leaf scorches, and many other similar diseases. Although the complete genome sequences of several strains of this organism are now available, the function of most genes in this organism, especially those conferring virulence, is lacking. attachment of X. fastidiosa to xylem vessels and insect vectors may be required for virulence and transmission: therefore, we disrupted fimA and fimF, genes encoding the major fimbrial protein FimA and a homolog of the fimbrial adhesin MrkD, to determine their role in the attachment process. Disruption of the fimA and fimF genes in Temecula 1 and STL grape strains of X. fastidiosa was obtained by homologous recombination using plasmids pFAK and pFFK, respectively. These vectors contained a kanamycin resistance gene cloned into either the fimA or fimF genes of X. fastidiosa grape strains Temecula1 or STL. Efficiency of transformation was sufficiently high (approximate to600 transformants per mug of pFFK DNA) to enable selection of rare recombination events. Polymerase chain reaction and Southern blot analyses of the mutants indicated that a double crossover event had occurred exclusively within the fimA and fimF genes, replacing the chromosomal gene with the disrupted gene and abolishing production of the corresponding proteins, FimA or FimF Scanning electron microscopy revealed that fimbriae size and number, cell aggregation, and cell size were reduced for the FimA(-) or FimF mutants of X.fastidiosa when compared with the parental strain. FimA- or FimF(-) mutants of X. fastidiosa remained pathogenic to grapevines, with bacterial populations slightly reduced compared with those of the wild-type X.fastidiosa cells. These mutants maintained their resistance to kanamycin in planta for at least 6 months in the greenhouse. C1 Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Dept Energy, Joint Genome Inst, Walnut Creek, CA 94598 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. RP Lindow, SE (reprint author), Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. NR 39 TC 21 Z9 22 U1 1 U2 6 PU AMER PHYTOPATHOLOGICAL SOC PI ST PAUL PA 3340 PILOT KNOB ROAD, ST PAUL, MN 55121 USA SN 0031-949X J9 PHYTOPATHOLOGY JI Phytopathology PD JUN PY 2003 VL 93 IS 6 BP 675 EP 682 DI 10.1094/PHYTO.2003.93.6.675 PG 8 WC Plant Sciences SC Plant Sciences GA 682CA UT WOS:000183071900005 PM 18943053 ER PT J AU Neumann, PM De Souza, MP Pickering, IJ Terry, N AF Neumann, PM De Souza, MP Pickering, IJ Terry, N TI Rapid microalgal metabolism of selenate to volatile dimethylselenide SO PLANT CELL AND ENVIRONMENT LA English DT Article DE detoxification; dimethylselenide; hyper-volatilization; microalgae; selenium accumulation; speciation; sulphate-transporter; wetlands; X-ray-absorption-spectroscopy ID RAY-ABSORPTION SPECTROSCOPY; SELENIUM VOLATILIZATION; INDIAN MUSTARD; SULFATE TRANSPORTERS; ARABIDOPSIS-THALIANA; HIGHER-PLANTS; ASSIMILATION; ACCUMULATION; ALGAE; ROOTS AB An axenically cultured isolate of single-celled freshwater microalgae (Chlorella sp.) metabolized toxic selenate to volatile dimethylselenide at exceptionally high rates when transferred from mineral-nutrient solution to water for 24 h. The Se-volatilization rates were orders of magnitude higher than those similarly measured for wetland macroalgae and higher plants. Ninety percent of 20 muM selenate supplied to the microalgae incubated without nutrients was removed through accumulation and volatilization. Additions of 1 mM sulphate but not nitrate, inhibited Se accumulation and volatilization so that only 1.8% of the supplied selenate was removed. The microalgae cultured in nutrient solution without sulphate showed increased S-35-sulphate-transporter activity. Selenium K-edge X-ray absorption spectroscopy of selenate-treated microalgae cultured with or without mineral nutrients, showed that 87% of the selenate accumulated during 24 h was reductively metabolized to intermediate organic compounds such as selenomethionine and selenocystine. This is in complete contrast to higher plants that show very limited reduction of selenate. It appears that high rates of Se accumulation and volatilization by the sulphate-deprived microalgae resulted from reduced competition with chemically analogous sulphate ions for selenate uptake via up-regulated sulphate/selenate transporters and rapid reductive metabolism of selenate. Hyper-volatilization of selenate by microalgal cells may provide a novel detoxification response. C1 Technion Israel Inst Technol, Fac Civil & Environm Engn, Div Agr Engn, IL-32000 Haifa, Israel. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Neumann, PM (reprint author), Technion Israel Inst Technol, Fac Civil & Environm Engn, Div Agr Engn, IL-32000 Haifa, Israel. RI Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 NR 29 TC 40 Z9 42 U1 1 U2 15 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD JUN PY 2003 VL 26 IS 6 BP 897 EP 905 DI 10.1046/j.1365-3040.2003.01022.x PG 9 WC Plant Sciences SC Plant Sciences GA 687EK UT WOS:000183363000011 ER PT J AU Inoue, K Keegstra, K AF Inoue, K Keegstra, K TI A polyglycine stretch is necessary for proper targeting of the protein translocation channel precursor to the outer envelope membrane of chloroplasts SO PLANT JOURNAL LA English DT Article DE chloroplast targeting; import; envelope membrane; protein translocation channel; Toc75; polyglycine ID IMPORT APPARATUS; TRANSIT PEPTIDES; COMPONENT; MITOCHONDRIAL; ALIGNMENT; EVOLUTION; MACHINERY; INSERTION; ORIGIN; DOMAIN AB Toc75 is a protein translocation channel in the outer envelope membrane of chloroplasts and its presence is essential for the biogenesis of the organelles. Toc75 is the only protein identified so far in the outer membrane of chloroplasts or mitochondria that is synthesized as a larger precursor, preToc75, with a bipartite transit peptide. Its N-terminus targets the protein to the stroma and is removed by the stromal processing peptidase, whereas its C-terminus mediates envelope targeting and is removed by a yet unknown peptidase. Several conserved domains have been identified in the C-terminal portion of the preToc75 transit peptide from six plant species. We evaluated their importance in the biogenesis of Toc75 by means of deletion or site-directed mutagenesis, followed by import experiments using isolated chlroplasts. Among the conserved domains, a polyglycine stretch was found to be necessary for envelope targeting. Substitution of this domain with other stretches of a single amino acid such as alanine caused mistargeting of the protein into the stroma, indicating an important role for this domain. Furthermore, a glutamate at +2 and two alanine residues at -3 and -1 to the second cleavage site were found to be important for processing. A potential mechanism for the biogenesis of Toc75 is discussed. C1 Michigan State Univ, MSU DOE, Plant Res Lab, E Lansing, MI 48824 USA. Univ Calif Davis, Dept Pomol, Davis, CA 95616 USA. Michigan State Univ, Dept Plant Biol, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. RP Inoue, K (reprint author), Michigan State Univ, MSU DOE, Plant Res Lab, E Lansing, MI 48824 USA. NR 38 TC 60 Z9 66 U1 0 U2 5 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0960-7412 J9 PLANT J JI Plant J. PD JUN PY 2003 VL 34 IS 5 BP 661 EP 669 DI 10.1046/j.1365-313X.2003.01755.x PG 9 WC Plant Sciences SC Plant Sciences GA 682BE UT WOS:000183069700009 PM 12787247 ER PT J AU Heidbrink, WW Fredrickson, E Gorelenkov, NN Hyatt, AW Kramer, G Luo, Y AF Heidbrink, WW Fredrickson, E Gorelenkov, NN Hyatt, AW Kramer, G Luo, Y TI An Alfven eigenmode similarity experiment SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID DIII-D TOKAMAK; ENERGETIC PARTICLES; TOROIDAL PLASMAS; TOROIDICITY; DRIVEN; INSTABILITIES; FREQUENCY; EXCITATION; OPERATION; PROFILE AB The major radius dependence of Alfven mode stability is studied by creating plasmas with similar minor radius, shape, magnetic field (0.5 T), density (n(e) similar or equal to 3 x 10(19) m(-3)), electron temperature (1.0 keV) and beam ion population (near-tangential 80 keV deuterium injection) on both NSTX and DIII-D. The major radius of NSTX is half the major radius of DIII-D. The super-Alfvenic beam ions that drive the modes have overlapping values of upsilon(f)/upsilon(A) in the two devices. Observed beam-driven instabilities include toroidicity-induced Alfven eigenmodes (TAE). The stability threshold for the TAE is similar in the two devices. As expected theoretically, the most unstable toroidal mode number n is larger in DIII-D. C1 Univ Calif Irvine, Irvine, CA 92717 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Gen Atom Co, San Diego, CA USA. RP Heidbrink, WW (reprint author), Univ Calif Irvine, Irvine, CA 92717 USA. NR 34 TC 19 Z9 19 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD JUN PY 2003 VL 45 IS 6 BP 983 EP 997 AR PII S0741-3335(03)60441-0 DI 10.1088/0741-3335/45/6/311 PG 15 WC Physics, Fluids & Plasmas SC Physics GA 699NR UT WOS:000184063300012 ER PT J AU Lin, Y Wukitch, SJ Bonoli, PT Marmar, E Mossessian, D Nelson-Melby, E Phillips, P Porkolab, M Schilling, G Wolfe, S Wright, J AF Lin, Y Wukitch, SJ Bonoli, PT Marmar, E Mossessian, D Nelson-Melby, E Phillips, P Porkolab, M Schilling, G Wolfe, S Wright, J TI Ion cyclotron range of frequencies mode conversion electron heating in deuterium-hydrogen plasmas in the Alcator C-Mod tokamak SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID BERNSTEIN WAVES; PROPAGATION; PROFILE; DRIVE; TFTR; JET AB Localized direct electron heating (EH) by mode-converted (MC) ion cyclotron range of frequencies (ICRF) waves in D(H) tokamak plasmas has been clearly observed for the first time in Alcator C-Mod. Both on- and off-axis (high field side) mode conversion EH (MCEH) have been observed. The MCEH profile was obtained from a break-in-slope analysis of electron temperature signals in the presence of radio frequency shut-off. The temperature was measured by a 32-channel high spatial resolution (less than or equal to7 mm) 2nd harmonic heterodyne electron cyclotron emission system. The experimental profiles were compared with the predictions from a toroidal full-wave ICRF code TORIC. Using the hydrogen concentration measured by a high-resolution optical spectrometer, TORIC predictions were shown qualitatively in agreement with the experimental results for both on- and off-axis MC cases. From the simulations, the EH from MC ion cyclotron wave and ion Bernstein wave is examined. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Ecole Polytech Fed Lausanne, Assoc Euratom Confederat Suisse, Ctr Rech Phys Plasmas, CH-1015 Lausanne, Switzerland. Univ Texas, Fus Res Ctr, Austin, TX 78712 USA. Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lin, Y (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Lin, Yijun/B-5711-2009 NR 32 TC 25 Z9 26 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD JUN PY 2003 VL 45 IS 6 BP 1013 EP 1026 AR PII S0741-3335(03)59424-6 DI 10.1088/0741-3335/45/6/313 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 699NR UT WOS:000184063300014 ER PT J AU Runge, JM Pomis, A AF Runge, JM Pomis, A TI Anodic oxide finishes: Relating engineering performance to microstructure & hardness SO PLATING AND SURFACE FINISHING LA English DT Article AB Comparative testing of Type II, Type III and composite anodic finishes by conventional Taber abrasion, pin-on-disk friction and microhardness testing, as well as unconventional Torque and Charpy impact testing, have brought to light the importance of the engineering property of fracture toughness. Test performance differences and comparative microstructural analysis suggest enhanced wear may indeed be a function of higher toughness rather than hardness. Increased cohesive strength within the microstructure of the anodic finish, established through modifications to the anodizing process, appears to yield lower friction and reduced wear in even dissimilar wear couples. C1 Argonne Natl Lab, Nucl Technol Dept, Div Chem Technol, Argonne, IL 60439 USA. RP Runge, JM (reprint author), Argonne Natl Lab, Nucl Technol Dept, Div Chem Technol, Bldg 205,9700 S Cass Ave, Argonne, IL 60439 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 USA SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD JUN PY 2003 VL 90 IS 6 BP 60 EP 64 PG 5 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA 688DL UT WOS:000183417800008 ER PT J AU Fulton, JL Deverman, GS Yonker, CR Grate, JW De Young, J McClain, JB AF Fulton, JL Deverman, GS Yonker, CR Grate, JW De Young, J McClain, JB TI Thin fluoropolymer films and nanoparticle coatings from the rapid expansion of supercritical carbon dioxide solutions with electrostatic collection SO POLYMER LA English DT Article DE polymer science and technology; polymer materials; polymer composite materials ID FLUID SOLUTIONS; FIBERS; CO2 AB Application of nanometer thick fluoropolymer films onto metal and semiconducting substrates is described. In the first step, nanometer-sized polymer particles are generated by a process of homogeneous nucleation during the rapid expansion of supercritical fluid solutions. These gas-phase particles are then charged as they are being formed by application of a high voltage to the expansion nozzle. In this way the charged nanoparticles can be collected on a solid surface forming uniform coatings with thicknesses from tens of nanometers to several micrometers thick. Supercritical carbon dioxide solutions of three different fluoropolymers were used to generate different types of coatings. This represents a 'green' process for film deposition. A further unique aspect of this process is that the small charged nanoparticles can be deposited to electrically conducting microscopic regions with a spatial resolution better than 50 nm. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. Micell Technol, Raleigh, NC 27617 USA. RP Fulton, JL (reprint author), Pacific NW Natl Lab, Fundamental Sci Div, Battelle Blvd POB 999,MS P8-19, Richland, WA 99352 USA. NR 17 TC 20 Z9 20 U1 1 U2 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD JUN PY 2003 VL 44 IS 13 BP 3627 EP 3632 DI 10.1016/S0032-3861(03)00280-5 PG 6 WC Polymer Science SC Polymer Science GA 688LJ UT WOS:000183436200002 ER PT J AU Hathorn, BC Sumpter, BG Noid, DW Tuzun, RE Yang, C AF Hathorn, BC Sumpter, BG Noid, DW Tuzun, RE Yang, C TI Computational simulation of polymer particle structures: vibrational normal modes using the time averaged normal coordinate analysis method SO POLYMER LA English DT Article DE vibrational normal modes; time averaged normal coordinate analysis; dimer ID MOLECULAR-DYNAMICS SIMULATION; NANOPARTICLE COLLISIONS; MACROMOLECULAR SYSTEMS; MECHANICS CALCULATIONS; CRYSTALS AB The structures composed of individual polymer nanoparticles are simulated using a molecular dynamics technique. Structures composed of model polyethylene particles consisting of between 3000 and 24,000 monomer units are paired into dimers in a molecular dynamics simulation. The vibrational motion of the polymer particle structures corresponding to the stretching vibration between particles is studied using the time averaged normal coordinate analysis method. The data are fit to an empirical formula based on the expected scaling of the force constants with the surface contact area, yielding a formula which could be extrapolated to large particle structures which can be experimentally generated. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Comp Sci & Math, Oak Ridge, TN 37831 USA. SUNY Coll Brockport, Dept Computat Sci, Brockport, NY 14420 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. RP Hathorn, BC (reprint author), Oak Ridge Natl Lab, Div Comp Sci & Math, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 26 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD JUN PY 2003 VL 44 IS 13 BP 3761 EP 3767 AR PII S0032-3861(02)00436-6 DI 10.1016/S0032-3861(02)00436-6 PG 7 WC Polymer Science SC Polymer Science GA 688LJ UT WOS:000183436200019 ER PT J AU Maxwell, RS Cohenour, R Sung, W Solyom, D Patel, M AF Maxwell, RS Cohenour, R Sung, W Solyom, D Patel, M TI The effects of gamma-radiation on the thermal, mechanical, and segmental dynamics of a silica filled, room temperature vulcanized polysiloxane rubber SO POLYMER DEGRADATION AND STABILITY LA English DT Article DE siloxanes; radiation; Crosslinking; NMR; DSC; DMA ID POLYDIMETHYLSILOXANE; CROSSLINKING; DENSITY AB RTV-5370 is a filled polydimethylsilxoane-polymethylphenylsiloxane copolymer system originally developed by Dow Coming and now supplied by Rhone Poulenc. There is a desire to develop lifetime assessments of this material for certification programs and as a model system for understanding other filled siloxane polymer systems. We have initiated aging studies on these materials by employing accelerated aging tests with exposure to Co-60 gamma-radiation. The effects of radiation exposure have been investigated by thermal (differential scanning calorimetry), mechanical (dynamic mechanical analysis), chemical (solvent swelling), and segmental dynamics (nuclear magnetic resonance) methods. The data show that RTV-5370 undergoes predominately radiation-induced crosslinking reactions over the dose range investigated. These reactions reduce the molecular weight between crosslinks, thereby hardening the composite and reducing the motional dynamics of segmental motion. DSC studies show dose dependent crystallization phenomena. Published by Elsevier Science Ltd. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Honeywell Fed Mfg & Technol, Kansas City, MO 64141 USA. Atom Weapons Estab, Reading RG7 4PR, Berks, England. RP Maxwell, RS (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,L-091, Livermore, CA 94551 USA. NR 26 TC 67 Z9 71 U1 3 U2 22 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-3910 J9 POLYM DEGRAD STABIL JI Polym. Degrad. Stabil. PD JUN PY 2003 VL 80 IS 3 BP 443 EP 450 DI 10.1016/S0141-3910(03)00028-4 PG 8 WC Polymer Science SC Polymer Science GA 674KK UT WOS:000182635800006 ER PT J AU Tissot, RG AF Tissot, RG TI Microdiffraction applications utilizing a two-dimensional proportional detector SO POWDER DIFFRACTION LA English DT Article; Proceedings Paper CT 52nd Annual Denver X-Ray Conference CY AUG 04-08, 2003 CL DENVER, COLORADO SP Int Ctr Diffract Data DE area detectors; microdiffraction; applications; two-dimensional detectors AB Two-dimensional proportional detectors with their faster data collection, large dynamic range, and more available information than point or linear proportional detectors make them ideal for microdiffraction analysis. The unique capabilities of these detectors coupled with a rotating anode source, capillary optics, and a variety of accessories allow for a wide range of applications. (C) 2003 International Centre for Diffraction Data. C1 Sandia Natl Labs, Mat Characterizat Dept 1822, Albuquerque, NM 87185 USA. RP Tissot, RG (reprint author), Sandia Natl Labs, Mat Characterizat Dept 1822, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 9 Z9 11 U1 0 U2 1 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD JUN PY 2003 VL 18 IS 2 BP 86 EP 90 DI 10.1154/1.1577354 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 688LK UT WOS:000183436300004 ER PT J AU Rodriguez, MA Ingersoll, D Doughty, DH AF Rodriguez, MA Ingersoll, D Doughty, DH TI Quantitative analysis of Li contents in LixCoO2 cathodes via Rietveld refinement SO POWDER DIFFRACTION LA English DT Article; Proceedings Paper CT 52nd Annual Denver X-Ray Conference CY AUG 04-08, 2003 CL DENVER, COLORADO SP Int Ctr Diffract Data DE Rietveld; LixCoO2; lithium; cobalt; oxide; Li-ion battery ID LITHIUM AB Rietveld refinement of LixCoO2-type cathodes (where x=0.59-1.00) has been demonstrated to yield quantitative information about the Li occupancy with an error of about similar to 10%. With careful X-ray diffraction (XRD) data collection, refinement, and proper calibration, accurate values can be obtained. Rietveld refinement tends to under-predict the Li occupancy values in charged (de-lithiated) cathodes as compared to ICP measurements. A Li-gradient model that assumes a decreasing concentration of Li from the particle core to its surface is discussed to explain this observation. The observed lattice parameters for the fully lithiated LiCoO2 standard phase (R-3m symmetry) were a= 2.8155(1) Angstrom, c= 14.052(1) Angstrom. The error convention used in this paper is 3sigma of standard deviations obtained from Rietveld refinement output. (C) 2003 International Centre for Diffraction Data. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rodriguez, MA (reprint author), Sandia Natl Labs, POB 5800,MS 1411, Albuquerque, NM 87185 USA. NR 8 TC 2 Z9 2 U1 1 U2 14 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD JUN PY 2003 VL 18 IS 2 BP 135 EP 139 DI 10.1154/1.1528195 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 688LK UT WOS:000183436300012 ER PT J AU Howe, JY Rawn, CJ Jones, LE Ow, H AF Howe, JY Rawn, CJ Jones, LE Ow, H TI Improved crystallographic data for graphite SO POWDER DIFFRACTION LA English DT Article; Proceedings Paper CT 52nd Annual Denver X-Ray Conference CY AUG 04-08, 2003 CL DENVER, COLORADO SP Int Ctr Diffract Data DE graphite; powder diffraction; synchrotron X-ray AB Powder diffraction pattern of SP-1 graphite has been obtained using synchrotron X-ray diffraction. Unit cell dimensions were calculated using a least-squares analysis that refined to a \Delta2thetadegrees\ of no more than 0.007. A hexagonal cell was determined with a space group of P6(3)/mmc (194), a=2.4617(2) and c=6.7106 (4) Angstrom. The Smith/Synder figure of merit is 167 based upon 11 peaks, which indicates that the quality of this data set is superior to the existing PDF card for graphite, 41-1487. It is also emphasized that the interlayer spacing of graphite should be 3.355(1) Angstrom. Using GAS and EXPGUI codes, a new set of calculated powder diffraction data based upon the interlayer spacing of 3.555 Angstrom is generated. A comparison with the current calculated card, 75-1621, has also been made. (C) 2003 International Centre for Diffraction Data. C1 Oak Ridge Natl Lab, Div Met & Ceram, High Temp Mat Lab, Oak Ridge, TN 37831 USA. Alfred Univ, Sch Ceram Engn & Mat Sci, Alfred, NY 14802 USA. RP Howe, JY (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, High Temp Mat Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Howe, Jane/G-2890-2011 NR 23 TC 22 Z9 23 U1 1 U2 11 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD JUN PY 2003 VL 18 IS 2 BP 150 EP 154 DI 10.1154/1.1536926 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 688LK UT WOS:000183436300016 ER PT J AU Casalnuovo, S Brown, RB AF Casalnuovo, S Brown, RB TI Special issue on chemical and biological microsensors SO PROCEEDINGS OF THE IEEE LA English DT Editorial Material C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. RP Casalnuovo, S (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD JUN PY 2003 VL 91 IS 6 BP 827 EP 829 DI 10.1109/JPROC.2003.813578 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 693AM UT WOS:000183692500001 ER PT J AU Grate, JW Nelson, DA AF Grate, JW Nelson, DA TI Sorptive polymeric materials and photopatterned films for gas phase chemical microsensors SO PROCEEDINGS OF THE IEEE LA English DT Article DE microsensor; acoustic wave; vapor; sorption; polymer; photopattern ID ACOUSTIC-WAVE MICROSENSORS; SENSOR ARRAYS; PATTERN-RECOGNITION; PIEZOELECTRIC-CRYSTALS; CERAMIC PRECURSOR; PHOSPHORUS ESTERS; OPTICAL SENSORS; RESPONSES; DEVICES; SYSTEM AB The selective layer on a gas phase chemical microsensor plays a critical role in the sensitivity and selectivity of the sensor's response. Polymers can rapidly and reversibly absorb vapor molecules. As sorptive layers on chemical sensors, polymers are useful for a variety of chemical microsensor types and transduction mechanisms, either as is or as composites with conductive particles or dyes. The performance requirements for polymers are described in terms of their chemical and physical properties. A versatile synthetic approach for preparing sensing polymers has been developed using hydrosilylation chemistry to prepare carbosiloxane polymers. Polymers with diverse chemical selectivities have been prepared by this method. Furthermore, sorptive polymer materials can be photopatterned into defined areas on surfaces using a photoactivated catalyst and hydrosilylation chemistry. Polymer films with diverse chemical selectivities have been patterned with this new method. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Grate, JW (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 55 TC 18 Z9 19 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD JUN PY 2003 VL 91 IS 6 BP 881 EP 889 DI 10.1109/JPROC.2003.813575 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 693AM UT WOS:000183692500006 ER PT J AU Ramanathan, K Contreras, MA Perkins, CL Asher, S Hasoon, FS Keane, J Young, D Romero, M Metzger, W Noufi, R Ward, J Duda, A AF Ramanathan, K Contreras, MA Perkins, CL Asher, S Hasoon, FS Keane, J Young, D Romero, M Metzger, W Noufi, R Ward, J Duda, A TI Properties of 19.2% efficiency ZnO/CdS/CuInGaSe2 thin-film solar cells SO PROGRESS IN PHOTOVOLTAICS LA English DT Article DE copper indium gallium selenide; Cu(In,Ga)Se-2; ternary chalcopyrite; thin film solar cells; three stage process; photovoltaics; solar conversion efficiency ID CU(IN,GA)SE-2 AB We report the growth and characterization of record-efficiency ZnO/CdS/CuInGaSe2 thin-film solar cells. Conversion efficiencies exceeding 19% have been achieved for the first time, and this result indicates that the 20% goal is within reach. Details of the experimental procedures are provided, and material and device characterization data are presented. Published in 2003 by John Wiley Sons, Ltd. C1 NREL, Golden, CO 80401 USA. RP Ramanathan, K (reprint author), NREL, 1617 Cole Blvd, Golden, CO 80401 USA. NR 6 TC 704 Z9 726 U1 18 U2 149 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JUN PY 2003 VL 11 IS 4 BP 225 EP 230 DI 10.1002/pip.494 PG 6 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 691UQ UT WOS:000183624600001 ER PT J AU Millard, CS Stols, L Quartey, P Kim, Y Dementieva, I Donnelly, MI AF Millard, CS Stols, L Quartey, P Kim, Y Dementieva, I Donnelly, MI TI A less laborious approach to the high-throughput production of recombinant proteins in Escherichia coli using 2-liter plastic bottles SO PROTEIN EXPRESSION AND PURIFICATION LA English DT Article DE structural genomics; functional genomics; high-throughput; heterologous expression ID FREE TRANSLATION SYSTEM; GLYCEROPHOSPHODIESTER PHOSPHODIESTERASE; STRUCTURAL GENOMICS; PURIFICATION; EXPRESSION; PROTEASE; CLEAVAGE; CLONING AB Contemporary approaches to biology often call for the high-throughput production of large amounts of numerous proteins for structural or functional studies. Even with the highly efficient protein expression systems developed in Escherichia coli, production of these proteins is laborious and time-consuming. We have simplified established protocols by the use of disposable culture vessels: common 2-liter polyethylene terephthalate beverage bottles. The bottles are inexpensive, fit conveniently in commonly available flask holders, and, because they are notched, provide sufficient aeration to support the growth of high-density cultures. The use of antibiotics and freshly prepared media alleviates the need for sterilization of media and significantly reduces the labor involved. Uninoculated controls exhibited no growth during the time required for protein expression in experimental cultures. The yield, solubility, activity, and pattern of crystallization of proteins expressed in bottles were comparable to those obtained under conventional culture conditions. After use, the bottles are discarded, reducing the risk of cross-contamination of subsequent cultures. The approach appears to be suitable for high-throughput production of proteins for structural or functional studies. (C) 2003 Elsevier Science (USA). All rights reserved. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Donnelly, MI (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 202-Rm BE111,9700 S Cass Ave, Argonne, IL 60439 USA. FU NIGMS NIH HHS [GM 62414-01] NR 21 TC 24 Z9 29 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1046-5928 J9 PROTEIN EXPRES PURIF JI Protein Expr. Purif. PD JUN PY 2003 VL 29 IS 2 BP 311 EP 320 DI 10.1016/S1046-5928(03)00063-9 PG 10 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 687NA UT WOS:000183382100023 PM 12767824 ER PT J AU Plummer, MA Phillips, FM AF Plummer, MA Phillips, FM TI A 2-D numerical model of snow/ice energy balance and ice flow for paleoclimatic interpretation of glacial geomorphic features SO QUATERNARY SCIENCE REVIEWS LA English DT Article ID CENTRAL SIERRA-NEVADA; COLORADO FRONT RANGE; ALPINE REGION; MASS-BALANCE; COVER ENERGY; CLIMATE; SURFACE; CALIFORNIA; RADIATION; EXCHANGE AB Standard methods of interpreting the paleoclimates recorded in alpine glacial geomorphic features rely on estimates of paleoglacier shape, commonly assume that relationships between mass balance gradient and equilibrium line altitude of modern glaciers apply equally well to glaciers of, in many cases, dramatically different climates, and do not account for the varying influence of topography on glacial extent. While those methods may be adequate for many studies, there are an increasing number of areas in which that level of analysis does not match the level of detail of the glacial chronologies being developed. As an alternative, we present a physically based, 2-D, glacier model that can be used to determine steady-state glacier shapes and distributions for a wide range of climatic conditions. The model requires only a modest amount of data beyond that which would be required for simpler methods, and includes a relatively accurate representation of the effects of topography on the largest component of the surface energy balance-shortwave radiation. It calculates 2-D, in the horizontal-plane, distribution of snow accumulation using a surface mass and energy balance approach and calculates the resultant glacier shapes with a 2-D flow model. In addition to offering a potentially more accurate reconstruction of paleoclimatic conditions, the model provides a means of performing detailed sensitivity analysis, establishing relationships between similar deposits in basins of different shape and aspect, and of predicting glacier shape terminus position in areas not yet explored. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Indaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. New Mexico Inst Min & Technol, Socorro, NM 87801 USA. RP Plummer, MA (reprint author), Indaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 39 TC 54 Z9 54 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PD JUN PY 2003 VL 22 IS 14 BP 1389 EP 1406 DI 10.1016/S0277-3791(03)00081-7 PG 18 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 697FX UT WOS:000183932500002 ER PT J AU Hahto, SK Hahto, ST Kwan, JW Leung, KN Grisham, LR AF Hahto, SK Hahto, ST Kwan, JW Leung, KN Grisham, LR TI Negative chlorine ions from multicusp radio frequency ion source for heavy ion fusion applications SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID BEAM AB Use of high mass atomic neutral beams produced from negative ions as drivers for inertial confinement fusion has been suggested recently. Best candidates for the negative ions would be bromine and iodine with sufficiently high mass and electron affinity. These materials require a heated vapor ion source. Chlorine was selected for initial testing because it has similar electron affinity to those of bromine and iodine, and is available in gaseous form. An experiment was set up by the Plasma and Ion Source Technology Group in Lawrence Berkeley National Laboratory to measure achievable current densities and other beam parameters by using a rf driven multicusp ion source [K. N. Leung, Rev. Sci. Instrum. 65, 1165 (1994); Q. Ji et al., Rev. Sci. Instrum. 73, 822 (2002)]. Current density of 45 mA/cm(2) was achieved with 99.5% of the beam as atomic negative chlorine at 2.2 kW of rf power. An electron to negative ion ratio as low as 7 to 1 was observed, while the ratio of positive and negative chlorine ion currents was 1.3. This in addition to the fact that the front plate biasing had almost no effect to the negative chlorine ion and electron currents indicates that a very high percentage of the negative charge in the extraction area of the ion source was in form of Cl- ions. A comparison of positive and negative chlorine ion temperatures was conducted with the pepper pot emittance measurement technique and very similar transverse temperature values were obtained for positive and negative chlorine ions. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Hahto, SK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 5 TC 11 Z9 11 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2003 VL 74 IS 6 BP 2987 EP 2991 DI 10.1063/1.1571973 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 683AG UT WOS:000183124100005 ER PT J AU Wang, YB Durham, WB Getting, IC Weidner, DJ AF Wang, YB Durham, WB Getting, IC Weidner, DJ TI The deformation-DIA: A new apparatus for high temperature triaxial deformation to pressures up to 15 GPa SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID X-RAY-DIFFRACTION; TRANSITION-ZONE; YIELD STRENGTH; CUBIC-ANVIL; PLASTIC-DEFORMATION; ROOM-TEMPERATURE; LATTICE STRAINS; MANTLE; MGO; RHEOLOGY AB A new deformation apparatus has been developed, based on the widely used cubic-anvil apparatus known as the DIA. Two differential rams, introduced in the upper and lower guide blocks, allow independent control of the differential strain and stress field under high confining pressure. Testing experiments with synchrotron x rays have demonstrated that this deformation DIA (D-DIA) is capable of generating up to 30% axial strain on a 1 - 2 mm long sample under confining pressures up to 15 GPa at simultaneous high temperatures. Various compressional strain rates from 10(-3) to about 5x10(-6) s(-1) have been achieved. Extensional experiments have also been carried out successfully. Strains are measured by x-ray imaging of the sample which has a length measurement precision of similar to0.1 mum; pressures are monitored using standard materials with well established equations of state. X-ray transparent anvils made of sintered polycrystalline cubic boron nitride have been successfully tested, with a two-dimensional x-ray charge coupled device detector. Distortions in the diffraction lines due to differential stress can be measured with a precision of about 20 MPa. (C) 2003 American Institute of Physics. C1 Univ Chicago, GeoSoilEnviroCARS, Chicago, IL 60637 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. SUNY Stony Brook, Dept Earth & Space Sci, Stony Brook, NY 11794 USA. RP Univ Chicago, GeoSoilEnviroCARS, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM wang@cars.uchicago.edu OI Wang, Yanbin/0000-0001-5716-3183 NR 40 TC 139 Z9 146 U1 2 U2 23 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2003 VL 74 IS 6 BP 3002 EP 3011 DI 10.1063/1.1570948 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 683AG UT WOS:000183124100008 ER PT J AU He, DW Zhao, YS Sheng, TD Schwarz, RB Qian, J Lokshin, KA Bobev, S Daemen, LL Mao, HK Hu, JZ Shu, J Xu, J AF He, DW Zhao, YS Sheng, TD Schwarz, RB Qian, J Lokshin, KA Bobev, S Daemen, LL Mao, HK Hu, JZ Shu, J Xu, J TI Bulk metallic glass gasket for high pressure, in situ x-ray diffraction SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID BORON SUBOXIDE; CRYSTALLIZATION; ALLOY; TEMPERATURE; SYSTEM; CELL AB Amorphous metallic alloys lack long-range atomic order and consequently exhibit excellent homogeneity, no microstructure discontinuities, and no sharp x-ray diffraction peaks. Moreover they have higher tensile fracture strength and hardness than those of traditional crystalline metals. These excellent physical properties make bulk metallic glasses good candidates for high pressure gaskets for in situ x-ray/neutron diffraction experiments. We tested the Pd40Ni40P20 amorphous alloy as a gasket material in three experiments. The behavior of the Pd40Ni40P20 amorphous alloy under a hydrostatic/nonhydrostatic pressure of over 100 GPa was investigated by in situ synchrotron x-ray diffraction. The pressure gradient of the amorphous metallic gasket in the diamond anvil cell was measured on the ruby fluorescence scale during compression and decompression. The results show that bulk metallic glasses are good high-pressure gasket materials for in situ x-ray diffraction experiments. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, MST, Los Alamos, NM 87545 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. RP He, DW (reprint author), Los Alamos Natl Lab, Los Alamos Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012 NR 28 TC 4 Z9 5 U1 4 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2003 VL 74 IS 6 BP 3012 EP 3016 DI 10.1063/1.1575926 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 683AG UT WOS:000183124100009 ER PT J AU Zhang, X Friderichsen, AV Nandi, S Ellison, GB David, DE McKinnon, JT Lindeman, TG Dayton, DC Nimlos, MR AF Zhang, X Friderichsen, AV Nandi, S Ellison, GB David, DE McKinnon, JT Lindeman, TG Dayton, DC Nimlos, MR TI Intense, hyperthermal source of organic radicals for matrix-isolation spectroscopy SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CORRESPONDING CARBONIUM-IONS; HELIUM(I) PHOTOELECTRON-SPECTRUM; + OXYGEN MATRICES; ALKYL RADICALS; ULTRAVIOLET PHOTOLYSIS; INFRARED-SPECTRA; MOLECULAR-IONS; SUPERSONIC JET; GAS-PHASE; ALLYL AB We have incorporated a pulsed, hyperthermal nozzle with a cryostat to study the matrix-isolated infrared spectroscopy of organic radicals. The radicals are produced by pyrolysis in a heated, narrow-bore (1-mm-diam) SiC tube and then expanded into the cryostat vacuum chamber. The combination of high nozzle temperature (up to 1800 K) and near-sonic flow velocities (on the order of 10(4) cm s(-1)) through the length of the 2 cm tube allows for high yield of radicals (approximately 10(13) radicals pulse(-1)) and low residence time (on the order of 10 mus) in the nozzle. We have used this hyperthermal nozzle/matrix isolation experiment to observe the IR spectra of complex radicals such as allyl radical (CH2CHCH2), phenyl radical (C6H5), and methylperoxyl radical (CH3OO). IR spectra of samples produced with a hyperthermal nozzle are remarkably clean and relatively free of interfering radical chemistry. By monitoring the unimolecular thermal decomposition of allyl ethyl ether in the nozzle using matrix IR spectroscopy, we have derived the residence time (tau(nozzle)) of the gas pulse in the nozzle to be around 30 mus. (C) 2003 American Institute of Physics. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Integrated Instrument Dev Facil, CIRES, Boulder, CO 80309 USA. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Colorado Coll, Dept Chem, Colorado Springs, CO 80903 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, X (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. NR 75 TC 55 Z9 55 U1 4 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2003 VL 74 IS 6 BP 3077 EP 3086 DI 10.1063/1.1574397 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 683AG UT WOS:000183124100020 ER PT J AU Tselev, A Anlage, SM Christen, HM Moreland, RL Talanov, VV Schwartz, AR AF Tselev, A Anlage, SM Christen, HM Moreland, RL Talanov, VV Schwartz, AR TI Near-field microwave microscope with improved sensitivity and spatial resolution SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID DISTANCE FEEDBACK-CONTROL; THIN-FILMS; RESISTANCE; PROBE AB The near-field scanning microwave microscope has become a popular instrument to quantitatively image high-frequency properties of metals and dielectrics on length scales far shorter than the wavelength of the radiation. We have developed several new ways to operate this microscope to dramatically improve its spatial resolution and material property sensitivity. These include a novel distance-following method that takes advantage of the stability of a synthesized microwave source to improve the signal-to-noise ratio of our earlier frequency-following imaging technique. We also discuss novel height-modulated imaging techniques, culminating in a new tapping-mode method, which makes a 14 dB improvement in sensitivity, a 17.5 dB improvement in signal-to-noise ratio, and a factor of 2.3 improvement in spatial resolution compared to distance-following imaging. (C) 2003 American Institute of Physics. C1 Univ Maryland, Dept Phys, MRSEC, College Pk, MD 20742 USA. Univ Maryland, Dept Phys, Ctr Superconduct Res, College Pk, MD 20742 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Neocera Inc, Beltsville, MD 20705 USA. Russian Acad Sci, Inst Phys Microstruct, Nizhnii Novgorod 603600, Russia. RP Anlage, SM (reprint author), Univ Maryland, Dept Phys, MRSEC, College Pk, MD 20742 USA. EM anlage@squid.umd.edu RI Christen, Hans/H-6551-2013; Tselev, Alexander/L-8579-2015 OI Christen, Hans/0000-0001-8187-7469; Tselev, Alexander/0000-0002-0098-6696 NR 20 TC 16 Z9 16 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2003 VL 74 IS 6 BP 3167 EP 3170 DI 10.1063/1.1571954 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 683AG UT WOS:000183124100037 ER PT J AU Altenberger, I Stach, EA Liu, G Nalla, RK Ritchie, RO AF Altenberger, I Stach, EA Liu, G Nalla, RK Ritchie, RO TI An in situ transmission electron microscope study of the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening SO SCRIPTA MATERIALIA LA English DT Article DE Ti-6Al-4V; AISI 304; fatigue; surface treatment; deep rolling; laser-shock peening ID CYCLIC DEFORMATION AB We investigate the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening in AISI 304 stainless steel (AISI 304) and Ti-6Al-4V using in situ transmission electron microscopy. The improvements in fatigue resistance at elevated temperature are related to the high-temperature stability of the work-hardened near-surface microstructure. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Kassel, Inst Mat Engn, D-3500 Kassel, Germany. Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Ritchie, RO (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RI Stach, Eric/D-8545-2011; Ritchie, Robert/A-8066-2008 OI Stach, Eric/0000-0002-3366-2153; Ritchie, Robert/0000-0002-0501-6998 NR 13 TC 42 Z9 50 U1 2 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUN PY 2003 VL 48 IS 12 BP 1593 EP 1598 DI 10.1016/S1359-6462(03)00143-X PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 676YB UT WOS:000182779200005 ER PT J AU Petkov, V Vogt, T AF Petkov, V Vogt, T TI Positional disorder of Ba in the thermoelectric germanium clathrate Ba6Ge25 SO SOLID STATE COMMUNICATIONS LA English DT Article DE Ba6Ge25; X-ray scattering; local structure ID X-RAY-DIFFRACTION; PAIR DISTRIBUTION FUNCTION; THERMAL-CONDUCTIVITY; PROGRAM AB The local structure of Ba6Ge25 has been studied by X-ray diffraction and the atomic pair distribution function technique at 40 K and room temperature. Unambiguous evidence has been found showing that two out of three types of Ba atoms in Ba6Ge25 move off their positions and become locked in split sites at low temperatures. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Petkov, V (reprint author), Cent Michigan Univ, Dept Phys, Dow 203, Mt Pleasant, MI 48859 USA. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 15 TC 11 Z9 11 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JUN PY 2003 VL 127 IS 1 BP 43 EP 46 DI 10.1016/S0038-1098(03)00372-7 PG 4 WC Physics, Condensed Matter SC Physics GA 700AU UT WOS:000184091100010 ER PT J AU Luo, B Ren, F Allums, KK Gila, BP Onstine, AH Abernathy, CR Pearton, SJ Dwivedi, R Fogarty, TN Wilkins, R Fitch, RC Gillespie, JK Jenkins, TJ Dettmer, R Sewell, J Via, GD Crespo, A Baca, AG Shul, RJ AF Luo, B Ren, F Allums, KK Gila, BP Onstine, AH Abernathy, CR Pearton, SJ Dwivedi, R Fogarty, TN Wilkins, R Fitch, RC Gillespie, JK Jenkins, TJ Dettmer, R Sewell, J Via, GD Crespo, A Baca, AG Shul, RJ TI Proton irradiation of MgO- or SC2O3 passivated AlGaN/GaN high electron mobility transistors SO SOLID-STATE ELECTRONICS LA English DT Article ID FIELD-EFFECT-TRANSISTORS; OXIDE-SEMICONDUCTOR DIODES; SURFACE PASSIVATION; GATE DIELECTRICS; PERFORMANCE; HEMTS; DC; BEHAVIOR; SIGNAL; HFETS AB AlGaN/GaN high electron mobility transistors with either MgO or Sc2O3 surface passivation were irradiated with 40 MeV protons at a dose of 5 x 10(9) cm(-2). While both forward and reverse bias current were decreased in the devices as a result of decreases in channel doping and introduction of generation-recombination centers, there was no significant change observed in gate lag measurements. By sharp contrast, unpassivated devices showed significant decreases in drain current under pulsed conditions for the same proton dose. These results show the effectiveness of the oxide passivation in mitigating the effects of surface states present in the as-grown structures and also of surface traps created by the proton irradiation. (C) 2003 Published by Elsevier Science Ltd. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Prairie View A&M Univ, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. NR 33 TC 21 Z9 21 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JUN PY 2003 VL 47 IS 6 BP 1015 EP 1020 DI 10.1016/S0038-1101(02)00468-9 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 668EM UT WOS:000182277400012 ER PT J AU Yang, ZG Stevenson, JW Meinhardt, KD AF Yang, ZG Stevenson, JW Meinhardt, KD TI Chemical interactions of barium-calcium-aluminosilicate-based sealing glasses with oxidation resistant alloys SO SOLID STATE IONICS LA English DT Article DE SOFC; interconnect; sealing glass; oxidation resistant alloys; corrosion ID OXIDE FUEL-CELL; DEGRADATION AB In most planar solid oxide fuel cells (SOFC) stack designs, the interconnect, which is typically made from an oxidation resistant alloy, potentially including austenitic chromia-forming, ferritic chromia-forming, and alumina-forming alloys, has to be hermitically sealed to its adjacent components, usually by a sealing glass. To maintain the structural stability and minimize the degradation of stack performance, the sealing glass must be chemically compatible with the alloy used for the interconnect. In this work, Nicrofer6025, AISI446 and a Fecralloy were selected as examples of austenitic chromia-forming, ferritic chromia-forming, and alumina-forming alloys, respectively. Their chemical compatibility with a barium-calcium-aluminosilicate (BCAS)-based glass, specifically developed as a sealant in SOFC stacks, was evaluated. It was found that the BCAS sealing glass interacted chemically with both the chromia-forming alloys and the alumina-forming alloys. The extent and nature of the interactions and their final products depended on the matrix alloy compositions, the exposure conditions and/or proximity of the glass/alloy interface to the ambient air. These interactions and their mechanisms will be discussed with the assistance of thermodynamic modeling. (C) 2003 Elsevier Science B.V All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Yang, ZG (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd, Richland, WA 99352 USA. NR 23 TC 121 Z9 126 U1 2 U2 24 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 JUN PY 2003 VL 160 IS 3-4 BP 213 EP 225 DI 10.1016/S0167-2738(03)00160-7 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 710JU UT WOS:000184677700001 ER PT J AU Marchand, AP Hazlewood, A Huang, ZL Vadlakonda, SK Rocha, JDR Power, TD Mlinaric-Majerski, K Klaic, L Kragol, G Bryan, JC AF Marchand, AP Hazlewood, A Huang, ZL Vadlakonda, SK Rocha, JDR Power, TD Mlinaric-Majerski, K Klaic, L Kragol, G Bryan, JC TI Stabilization of a K+-(bis-cage-annulated 20-crown-6) complex by bidentate picrate SO STRUCTURAL CHEMISTRY LA English DT Article DE oxahexacyclic cage compounds; crown ethers; picrate; interaction; energy calculations ID AB-INITIO CALCULATIONS; OF-THE-ART; EXTRACTION CAPABILITIES; CROWN-ETHERS; METAL-CATIONS; ALKALI; SELECTIVITIES; IONOPHORES; ENERGIES; PYRIDINE AB Bis-cage-annulated 18-crown-6 and 20-crown-6 macrocyclic ethers (i.e., 1 and 2, respectively) have been synthesized, and their alkali metal picrate extraction profiles have been determined. Host system 1 proved to be a significantly more avid alkali metal cation complexant than 2 and somewhat more avid than 18-crown-6. Both 1 and 18-crown-6 display modest selectivity toward K+ and Rb+. A stable host-guest complex was prepared by slow evaporation of a CH2Cl2-hexane solution of an equimolar mixture of 2 and potassium picrate. The X-ray crystal structure of this complex reveals that picrate anion functions as a bidentate ligand therein. The gas-phase interaction energy between the 2 . K-\ complex and picrate anion was calculated to be ca. -64.9 kcal mol(1), thereby indicating that participation of picrate anion as an additional bidentate ligand results in significant stabilization of complex 10. C1 Univ N Texas, Dept Chem, Denton, TX 76203 USA. Rudjer Boskovic Inst, Dept Organ Chem & Biochem, Zagreb 10002, Croatia. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Bryan, JC (reprint author), Univ N Texas, Dept Chem, NT Stn,Box 305070, Denton, TX 76203 USA. RI Rocha, John-David/A-3186-2013 OI Rocha, John-David/0000-0001-6394-4349 NR 52 TC 17 Z9 17 U1 2 U2 5 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 JUN PY 2003 VL 14 IS 3 BP 279 EP 288 DI 10.1023/A:1023863813356 PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Crystallography SC Chemistry; Crystallography GA 679MD UT WOS:000182925500006 ER PT J AU Mathews, II Deacon, AM Canaves, JM McMullan, D Lesley, SA Agarwalla, S Kuhn, P AF Mathews, II Deacon, AM Canaves, JM McMullan, D Lesley, SA Agarwalla, S Kuhn, P TI Functional analysis of substrate and cofactor complex structures of a thymidylate synthase-complementing protein SO STRUCTURE LA English DT Article ID CRYSTAL-STRUCTURE; ESCHERICHIA-COLI; THERMOTOGA-MARITIMA; ANGSTROM RESOLUTION; HYDROPHOBIC CORE; DIFFRACTION DATA; ANTICANCER DRUG; BINDING; SPECIFICITY; REDUCTASE AB Like thymidylate synthase (TS) in eukaryotes, the thymidylate synthase-complementing proteins (TSCPs) are mandatory for cell survival of many prokaryotes in the absence of external sources of thymidylate. Details of the mechanism of this novel family of enzymes are unknown. Here, we report the structural and functional analysis of a TSCP from Thermotoga maritima and its complexes with substrate, analogs, and cofactor. The structures presented here provide a basis for rationalizing the TSCP catalysis and reveal the possibility of the design of an inhibitor. We have identified a new helix-loop-strand FAD binding motif characteristic of the enzymes in the TSCP family. The presence of a hydrophobic core with residues conserved among the TSCP family suggests a common overall fold. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Stanford Univ, Joint Ctr Struct Genom, Menlo Pk, CA 94025 USA. San Diego Supercomp Ctr, La Jolla, CA 92093 USA. Novartis Fdn, Genom Inst, San Diego, CA 92121 USA. Univ Calif San Francisco, Dept Biochem & Biophys, San Francisco, CA 94143 USA. RP Mathews, II (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. FU NIGMS NIH HHS [P50-GM62411] NR 33 TC 54 Z9 54 U1 0 U2 4 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0969-2126 J9 STRUCTURE JI Structure PD JUN PY 2003 VL 11 IS 6 BP 677 EP 690 DI 10.1016/S0969-2126(03)00097-2 PG 14 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 689PL UT WOS:000183502100012 PM 12791256 ER PT J AU Eng, CW Halada, GP Francis, AJ Dodge, CJ Gillow, JB AF Eng, CW Halada, GP Francis, AJ Dodge, CJ Gillow, JB TI Uranium association with corroding carbon steel surfaces SO SURFACE AND INTERFACE ANALYSIS LA English DT Article DE steel; corrosion; uranium; contamination; XPS; RBS; FTIR; SIRMS; SEM; EDS ID RAY PHOTOELECTRON-SPECTROSCOPY; ATMOSPHERIC CORROSION; GOETHITE; RUST; LEPIDOCROCITE; PASSIVATION; DIFFRACTION; REDUCTION; MECHANISM; SPECTRA AB We investigated the association of uranium with clean and corroded surfaces of 1010 carbon steel. Studying steel contaminated by uranium species will have an important effect on the development of methods used to clean radioactively contaminated metal waste. X-ray photoelectron spectroscopy, synchrotron infrared microspectroscopy and laboratory-based Fourier transform infrared analysis of steel surfaces exposed to uranyl nitrate showed the presence of crystallized hydrated uranyl oxides, uranyl hydroxides, iron oxyhydroxides and iron oxides. In general, heavily corroded areas physically shield the uranium species, which tended to associate spatially with hydroxyl groups and lepidocrocite. Lightly corroded areas contained uranium species with stronger axial U-O bonding. Infrared spectroscopy, Rutherford backscattering spectroscopy and energy-dispersive spectroscopy mapping analysis revealed that the uranium species are well distributed within the upper micron of the thick corrosion layer and associated more with areas of high hydroxide content. Parameters such as the concentration of uranyl nitrate solution used to expose the carbon steel coupons, the method of contamination (dipped or sprayed with dilute uranyl nitrate solution) and the degree of corrosion (accelerated corrosion before and/or after contamination) played significant roles in the distribution and nature of the urartyl hydroxide/iron oxyhydroxide corrosion products found on the surface of all coupons. These factors must be considered in the development and optimization of decontamination processes for metal waste. Copyright (C) 2003 John Wiley Sons, Ltd. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Halada, GP (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. NR 27 TC 17 Z9 17 U1 2 U2 10 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD JUN PY 2003 VL 35 IS 6 BP 525 EP 535 DI 10.1002/sia.1566 PG 13 WC Chemistry, Physical SC Chemistry GA 696WH UT WOS:000183910200005 ER PT J AU Paul, J Williams, GP Hoffmann, FM AF Paul, J Williams, GP Hoffmann, FM TI Carbon dioxide activation and alkali compound formation. I. Vibrational characterization of oxalate intermediates SO SURFACE SCIENCE LA English DT Article DE ab initio quantum chemical methods and calculations; reflection spectroscopy; compound formation; alkali metals; carbon dioxide ID SYNCHROTRON-RADIATION; INFRARED-SPECTRA; METAL-SURFACES; CO2 ADSORPTION; POTASSIUM; RU(001); PHOTOEMISSION; CHEMISORPTION; SPECTROSCOPY; MATRICES AB The activation of CO2 in thin potassium layers adsorbed on Cu(1 1 1) has been studied with time-evolved Fourier transform-infrared reflection absorption spectroscopy. The growth of thin layers by reactive evaporation of potassium in a CO2 atmosphere permits control of the K:CO2 stoichiometry, which strongly affects the selectivity in the formation of intermediates and the decomposition pathways of the layer. Layers grown in a CO2 rich atmosphere exhibit the preferential growth of stoichiometric potassium oxalate K2C2O4 (D-2h). The molecular identity of oxalate with D-2h symmetry is confirmed by vibrational spectra utilizing isotopic substitution methods ((CO2)-C-13 and (CO2)-O-18) and by the use of isotopic mixtures of CO2/(C1O2)-O-8 and CO2/(CO2)-C-13. A comparison of the isotope data with theoretical calculations gives an estimated OCO bond angle in oxalate of 132degrees. Far-IR spectra obtained with synchrotron radiation indicate the equivalent interaction of all oxygen atoms with the potassium. A comparison of the vibrational data with theoretical ab initio calculations confirms the structural model of an oxalate species that is bulk coordinated with no strong directional bonding and all oxygen atoms equally interacting with potassium. At medium and low CO2:K ratios, very complex vibrational spectra are observed, indicating the formation of an oxalate surface species with C-2v symmetry in addition to D-2h(-) oxalate, CO2- and CO22- species. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lulea Univ Technol, Div Phys, S-97187 Lulea, Sweden. Jefferson Lab, Newport News, VA 23606 USA. SCI MED, New York, NY 10033 USA. RP Paul, J (reprint author), Lulea Univ Technol, Div Phys, S-97187 Lulea, Sweden. NR 43 TC 8 Z9 8 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 1 PY 2003 VL 531 IS 3 BP 244 EP 264 DI 10.1016/S0039-6028(03)00511-9 PG 21 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 685GW UT WOS:000183254900010 ER PT J AU Curtiss, LA AF Curtiss, LA TI Gaussian-3 and related methods for accurate thermochemistry (vol 108, pg 61, 2002) SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Correction C1 Argonne Natl Lab, Chem Technol & Mat Sci Dept, Argonne, IL 60439 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Chem Technol & Mat Sci Dept, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD JUN PY 2003 VL 109 IS 5 BP 239 EP 239 DI 10.1007/s00214-003-0430-x PG 1 WC Chemistry, Physical SC Chemistry GA 688TM UT WOS:000183452300001 ER PT J AU Webb, SW Pruess, K AF Webb, SW Pruess, K TI The use of Fick's law for modeling trace gas diffusion in porous media SO TRANSPORT IN POROUS MEDIA LA English DT Article DE dusty-gas model; advective-diffusive model; Fick's law; Knudsen diffusion; Klinkenberg; trace gas diffusion; gas diffusion; tortuosity ID BEHAVIOR ASSESSMENT MODEL; ORGANIC VAPOR TRANSPORT; SOIL; MIXTURES; COLUMNS; AIR AB Two models for combined gas-phase diffusion and advection in porous media, the advective-diffusive model (ADM) and the dusty-gas model (DGM), are commonly used. The ADM is based on a simple linear addition of advection calculated by Darcy's law and ordinary diffusion using Fick's law with a porosity-tortuosity-gas saturation multiplier to account for the porous medium. The DGM applies the kinetic theory of gases to the gaseous components and the porous media (or 'dust') to develop an approach for combined transport due to diffusion and advection that includes porous medium effect. The ADM and Fick's law are considered to be generally inferior for gas diffusion in porous media, and the more mechanistic DGM is preferred. Under trace gas diffusion conditions, Fick's law overpredicts the gas diffusion flux compared to the DGM. The difference between the two models increases as the permeability decreases. In addition, the difference decreases as the pressure increases. At atmospheric pressure, the differences are minor (<10%) for permeabilities down to about 10(-13) m(2). However, for lower permeabilities, the differences are significant and can approach two orders of magnitude at a permeability of 10(-18) m(2). In contrast, at a pressure of 100 atm, the maximum difference for a permeability of 10(-8) m(2) is only about a factor of 2. A molecule-wall tortuosity coefficient based on the DGM is proposed for trace gas diffusion using Fick's law. Comparison of the Knudsen diffusion fluxes has also been conducted. For trace gases heavier than the bulk gas, the ADM mass flux is higher than the DGM. Conversely, for trace gases lighter than the bulk gas, the ADM mass flux is lower than the DGM. Similar to the ordinary diffusion variation, the differences increase as the permeability decreases, and get smaller as the pressure increases. At atmospheric pressure, the differences are small for higher permeabilities (>10(-13) m(2)) but may increase to about 2.7 for He at lower permeabilities of about 10(-18) m(2). A modified Klinkenberg factor is suggested to account for differences in the models. C1 Sandia Natl Labs, Environm Technol Dept, Albuquerque, NM 87185 USA. Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Webb, SW (reprint author), Sandia Natl Labs, Environm Technol Dept, 6131-MS-0719, Albuquerque, NM 87185 USA. NR 37 TC 55 Z9 56 U1 5 U2 45 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD JUN PY 2003 VL 51 IS 3 BP 327 EP 341 DI 10.1023/A:1022379016613 PG 15 WC Engineering, Chemical SC Engineering GA 646AQ UT WOS:000181013000005 ER PT J AU Bradbury, A Velappan, N Verzillo, V Ovecka, M Chasteen, L Sblattero, D Marzari, O Lou, JL Siegel, R Pavlik, P AF Bradbury, A Velappan, N Verzillo, V Ovecka, M Chasteen, L Sblattero, D Marzari, O Lou, JL Siegel, R Pavlik, P TI Antibodies in proteomics I: generating antibodies SO TRENDS IN BIOTECHNOLOGY LA English DT Review ID PROTEIN-PROTEIN INTERACTIONS; SINGLE-CHAIN FV; YEAST SURFACE DISPLAY; PHAGE DISPLAY; ESCHERICHIA-COLI; AFFINITY MATURATION; SACCHAROMYCES-CEREVISIAE; INTRABODY CONSTRUCTION; MOLECULAR EVOLUTION; DIRECTED EVOLUTION AB The explosion in genome sequencing, and in subsequent DNA array experiments, has provided extensive information on gene sequence, organization and expression. This has resulted in a desire to perform similarly broad experiments on all the proteins encoded by a genome. Panels of specific antibodies, or other binding ligands, will be essential tools in this endeavour. Because traditional immunization will be unlikely to generate antibodies in sufficient quantity, and of the required quality and reproducibility, in vitro selection methods will probably be used. This review - the first of two - examines the strategies available for in vitro antibody selection. The second review discusses the adaptation of these methods to high throughput and the uses to which antibodies, once derived, can be put. C1 Los Alamos Natl Lab, Div B, Los Alamos, NM 87545 USA. Univ Calif San Francisco, Inst Neurodegenerat Dis, San Francisco, CA 94143 USA. Univ Trieste, Dipartimento Biol, Trieste, Italy. Univ Calif San Francisco, Dept Anesthesiol, San Francisco, CA 94110 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Bradbury, A (reprint author), Los Alamos Natl Lab, Div B, POB 1663, Los Alamos, NM 87545 USA. EM amb@lanl.gov OI Siegel, Robert/0000-0002-0833-5580 NR 91 TC 42 Z9 44 U1 4 U2 5 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0167-7799 J9 TRENDS BIOTECHNOL JI Trends Biotechnol. PD JUN PY 2003 VL 21 IS 6 BP 275 EP 281 DI 10.1016/S0167-7799(03)00112-4 PG 7 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 691TK UT WOS:000183621400009 PM 12788548 ER PT J AU Garten, CT Ashwood, TL AF Garten, CT Ashwood, TL TI A landscape level analysis of potential excess nitrogen in East-Central North Carolina, USA SO WATER AIR AND SOIL POLLUTION LA English DT Article DE landscape ecology; mass balance model; eutrophication; environmental health; water pollution; harmful algal blooms ID NEUSE-RIVER ESTUARY; RIPARIAN ZONES; UNITED-STATES; NITRATE; EXPORT; WATERS; DENITRIFICATION; GROUNDWATERS; PHOSPHORUS; DYNAMICS AB The objective of this research was to arrive at an assessment of potential excess nitrogen (N) under different land cover categories in the Neuse River Basin (North Carolina, USA) on a seasonal basis. Data on five processes (atmospheric N deposition, fertilization, net soil N mineralization, plant uptake, and denitrification) that contribute to potential excess N under different land cover categories were obtained from a literature review. Factors were also estimated to apportion annual N fluxes among different seasons of the year. Potential excess N was calculated as the difference between inputs to and outputs from an inorganic N pool. If inputs exceeded outputs, then the difference was assumed to represent N at risk of loss from the landscape to surface receiving waters and groundwaters. Land covers that were classified as potential N sources were influenced by soil N inventories and rates of net soil N mineralization (which is a natural process). The results indicated that there are large land areas in the Neuse River Basin that could be classified as either a N source or a N sink. Such areas are potentially sensitive because future changes in land use, or small alterations in N fluxes, could convert areas that are essentially in balance with respect to N biogeochemistry into the N source or N sink category. In this respect, model predictions indicate that the timing of N inputs and outputs on the landscape can be a critical determinant of potential excess N. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Garten, CT (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 46 TC 9 Z9 10 U1 0 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD JUN PY 2003 VL 146 IS 1-4 BP 3 EP 21 DI 10.1023/A:1023923105942 PG 19 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA 682TL UT WOS:000183108400001 ER PT J AU Salazar, KV Carroll, DW Trkula, M Sandoval, CW AF Salazar, KV Carroll, DW Trkula, M Sandoval, CW TI Hydrogen uptake on film surfaces produced by a unique codeposition process SO APPLIED SURFACE SCIENCE LA English DT Article DE DEB; codeposition; PVD; CVD; hydrogen getter ID PALLADIUM AB Hydrogen uptake on several different film surfaces has been achieved by deposition of a conventional hydrogen gettering system via a novel combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes. We decided to use a conventional hydrogen gettering system, developed by Smith and Schicker [J.R. Schicker, AS/KCD Project No. EPN-047620, May 19941, that uses an acetylenic organic compound mixed with carbon supported palladium metal. The organic material, 1,4-bis-(phenylethynyl) benzene (DEB), is mixed with palladium and carbon by employing conventional solid state ceramic preparative techniques. Our novel codeposition process combines PVD and CVD techniques for fabricating thin-film coatings of the palladium-catalyzed DEB hydrogen gettering system. Hydrogen uptake was confirmed by H-1 NMR and our novel process lends itself well to placing hydrogen getter onto complex shapes and substrates of various compositions. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Engn Sci & Applicat Div, Los Alamos, NM 87545 USA. RP Salazar, KV (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA. NR 6 TC 3 Z9 3 U1 0 U2 3 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 MAY 31 PY 2003 VL 214 IS 1-4 BP 20 EP 26 DI 10.1016/S0169-4332(03)00352-0 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 693RH UT WOS:000183731800004 ER PT J AU Poston, JA Siriwardane, RV Fisher, EP Miltz, AL AF Poston, JA Siriwardane, RV Fisher, EP Miltz, AL TI Thermal decomposition of the rare earth sulfates of cerium(III), cerium(IV), lanthanum(III) and samarium(III) SO APPLIED SURFACE SCIENCE LA English DT Article DE rare earth sulfates; sulfate decomposition; thermal decomposition; oxysulfate; X-ray photoelectron spectroscopy ID GAS-SOLID REACTIONS; STRUCTURAL MODEL; MOVING BOUNDARY; METAL SULFATES; SO2; SULPHATES; CAO(100); NICKEL; ZINC AB Surface and bulk chemical and elemental composition of the rare earth sulfates of cerium(III), cerium(IV), lanthanum(III) and samarium(III) were characterized during various stages of thermal decomposition. Decomposition was conducted under both vacuum and atmospheric conditions. In situ analysis was conducted on samples decomposed in vacuum. As identified by X-ray diffraction, the bulk decomposition of all the rare earth sulfate samples to their corresponding oxide, in atmosphere, proceeded via the formation of an oxysulfate. For the exception of cerium(III) sulfate, similar results were obtained in thermogravimetric analysis. The thermal decomposition profile, as determined by X-ray microanalysis was similar to that observed in thermogravimetric analysis and X-ray diffraction. Elemental maps revealed no observable concentration gradients of sulfur. Surface composition was not necessarily representative of the bulk composition. Thermal decomposition of sulfates to an oxide initiated at a lower temperature in vacuum than that observed at atmospheric pressure. (C) 2003 Elsevier Science B.V All rights reserved. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. EG&G TSWV Inc, Morgantown, WV 26507 USA. RP Poston, JA (reprint author), US DOE, Natl Energy Technol Lab, 3610 Collins Ferry Rd,POB 880, Morgantown, WV 26507 USA. NR 30 TC 40 Z9 40 U1 2 U2 9 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 MAY 31 PY 2003 VL 214 IS 1-4 BP 83 EP 102 DI 10.1016/S0169-4332(03)00358-1 PG 20 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 693RH UT WOS:000183731800011 ER PT J AU Cannon, WR AF Cannon, WR TI Whipple's disease, genomics, and drug therapy SO LANCET LA English DT Letter C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Cannon, WR (reprint author), Pacific NW Natl Lab, 902 Battle Blvd,K1-83,Box 999, Richland, WA 99352 USA. RI Cannon, William/K-8411-2014 OI Cannon, William/0000-0003-3789-7889 NR 4 TC 18 Z9 19 U1 0 U2 0 PU LANCET LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0140-6736 J9 LANCET JI Lancet PD MAY 31 PY 2003 VL 361 IS 9372 BP 1916 EP 1916 DI 10.1016/S0140-6736(03)13533-7 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA 684KL UT WOS:000183205800053 PM 12788617 ER PT J AU van Geen, A Zheng, Y Versteeg, R Stute, M Horneman, A Dhar, R Steckler, M Gelman, A Small, C Ahsan, H Graziano, JH Hussain, I Ahmed, KM AF van Geen, A Zheng, Y Versteeg, R Stute, M Horneman, A Dhar, R Steckler, M Gelman, A Small, C Ahsan, H Graziano, JH Hussain, I Ahmed, KM TI Spatial variability of arsenic in 6000 tube wells in a 25 km(2) area of Bangladesh SO WATER RESOURCES RESEARCH LA English DT Article DE arsenic; groundwater; Bangladesh; tube well ID WEST-BENGAL; GROUNDWATER; CONTAMINATION; WATER; DELTA AB Arsenic concentrations measured by graphite furnace atomic absorption range from <5 to 900 μg/L in groundwater pumped from 6000 wells within a 25 km(2) area of Bangladesh. The proportion of wells that exceed the Bangladesh standard for drinking water of 50 μg/L arsenic increases with depth from 25% between 8 and 10 m to 75% between 15 and 30 m, then declines gradually to less than 10% at 90 m. Some villages within the study area do not have a single well that meets the standard, while others have wells that are nearly all acceptable. In contrast to the distribution of arsenic in the 8-30 m depth range which does not follow any obvious geological feature, the arsenic content of groundwater associated with relatively oxic Pleistocene sand deposits appears to be consistently low. The depth of drilling necessary to reach these low-As aquifers ranges from 30 to 120 m depth within the study area. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. CUNY Queens Coll, Flushing, NY 11367 USA. Idaho Natl Environm & Engn Lab, Idaho Falls, ID USA. CUNY Bernard M Baruch Coll, New York, NY 10010 USA. Columbia Univ, Dept Stat, New York, NY 10027 USA. Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, New York, NY 10032 USA. Columbia Univ, Mailman Sch Publ Hlth, Dept Environm Hlth Sci, New York, NY 10032 USA. Natl Inst Prevent & Social Med, Dhaka 1212, Bangladesh. Univ Dhaka, Dept Geol, Dhaka 1000, Bangladesh. RP van Geen, A (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NR 34 TC 184 Z9 185 U1 3 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAY 31 PY 2003 VL 39 IS 5 AR 1140 DI 10.1029/2002WR001617 PG 16 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 686DG UT WOS:000183304800002 ER PT J AU McGrath, WJ Ding, JZ Didwania, A Sweet, RM Mangel, WF AF McGrath, WJ Ding, JZ Didwania, A Sweet, RM Mangel, WF TI Crystallographic structure at 1.6-angstrom resolution of the human adenovirus proteinase in a covalent complex with its 11-amino-acid peptide cofactor: insights on a new fold SO BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS LA English DT Article DE viral proteinase; peptide cofactor; cysteine proteinase; X-ray crystallographic refinement; active-site nucleophile ID PROTEASE INHIBITORS; CYSTEINE RESIDUES; VIRAL-DNA; SEQUENCE; CATALYSIS; BINDING; GENOME; PAPAIN AB The crystal structure of the human adenovirus proteinase (AVP), a cysteine proteinase covalently bound to its I I-amino-acid peptide cofactor pVIc, has been solved to 1.6-Angstrom resolution with a crystallographic R-factor of 0.136, R-free = 0.179. The fold of AVP-pVIc is new and the structural basis for it is described in detail. The polypeptide chain of AVP folds into two domains. One domain contains a five-strand beta-sheet with two peripheral a-helices; this region represents the hydrophobic core of the protein. A second domain contains the N terminus, several C-terminal a-helices, and a small peripheral anti-parallel beta-sheet. The domains interact through an extended polar interface. pVIc spans the two domains like a strap, its C-terminal portion forming a sixth strand on the beta-sheet. The active site is in a long, deep groove located between the two domains. Portions are structurally similar to the active site of the prototypical cysteine proteinase papain, especially some of the Calpha backbone atoms (r.m.s. deviation of 0.354 Angstrom for 12 Calpha atoms). The active-site nucleophile of AVP, the conserved CYS122, was shown to have a pK(a) of 4.5, close to the pK(a) of 3.0 for the nucleophile of papain, suggesting that a similar ion pair arrangement with His(54) may be present in AVP-pVIc. The interactions between AVP and pVIc include 24 non-beta-strand hydrogen bonds, six p-strand hydrogen bonds and one covalent bond. Of the 204 amino acid residues in AVP, 33 are conserved among the many serotypes of adenovirus, and these aid in forming the active site groove, are involved in substrate specificity or interact between secondary structure elements. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. RP Mangel, WF (reprint author), Brookhaven Natl Lab, Dept Biol, 50 Bell Ave, Upton, NY 11973 USA. FU NIAID NIH HHS [AI41599] NR 43 TC 23 Z9 24 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1570-9639 J9 BBA-PROTEINS PROTEOM JI BBA-Proteins Proteomics PD MAY 30 PY 2003 VL 1648 IS 1-2 BP 1 EP 11 DI 10.1016/S1570-9639(03)00024-4 PG 11 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 684PL UT WOS:000183215700001 PM 12758141 ER PT J AU Zhou, RB Wolk, CP AF Zhou, RB Wolk, CP TI A two-component system mediates developmental regulation of biosynthesis of a heterocyst polysaccharide SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SP-STRAIN PCC-7120; SIGNAL-TRANSDUCTION PROTEIN; ANABAENA SP; CYANOBACTERIUM-ANABAENA; ESCHERICHIA-COLI; PCC 7120; NOSTOC-PUNCTIFORME; MOLECULAR ANALYSIS; NITROGEN-FIXATION; HEPARAN-SULFATE AB Some cyanobacteria couple oxygenic photosynthesis in vegetative cells with O(2)-sensitive N(2) fixation in differentiated cells called heterocysts. Heterocyst differentiation involves extensive biochemical and structural changes that collectively permit heterocysts to assimilate N(2) aerobically and supply the products of N(2) fixation to vegetative cells. HepK and DevR are required for the development of functional heterocysts in Anabaena and Nostoc, respectively. We show that HepK is an autokinase and that Anabaena DevR(A) is its cognate response regulator, together comprising part or all of a two-component system that mediates developmental regulation of biosynthesis of a heterocyst envelope polysaccharide. Recombinant N-hexahistidine-tagged HepK (H(6)HepK), the cytoplasmic portion H(6)'HepK of H(6)HepK, H(6)DevR, and H(6)DevR(A) were overexpressed in Escherichia coli and purified to homogeneity. H(6)'HepK, but not H(6)HepK, autophosphorylates with [gamma-(32)P]ATP. ADP, specifically, elicits dephosphorylation of phosphorylated H(6)'HepK. The phosphoryl group of H(6)'HepK is transferred rapidly and efficiently to both H(6)DevR and H(6)DevRA but not to His-tagged OmpR, whose cognate sensor kinase is EnvZ. Sequence comparisons, the results of site-specific mutagenesis, and tests of chemical stability support identification of HepK-His(348) and DevR-Asp(53) as the phosphorylated residues. The mutation HepK-H348A abolishes both in vitro autokinase activity and in vivo functionality of HepK. Heterocysts of both hepK Anabaena and devR(A) Anabaena lack an envelope polysaccharide layer and are nonfunctional. Consistent with the normal site of deposition of that polysaccharide, a hepK::gfp transcriptional fusion is expressed principally in proheterocysts. HepK/DevR(A) is the first two-component system identified that regulates the biosynthesis of a polysaccharide as part of a patterned differentiation process. C1 Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Plant Biol, E Lansing, MI 48824 USA. Anhui Normal Univ, Coll Life Sci, Wuhu 241000, Anhui, Peoples R China. RP Wolk, CP (reprint author), Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. EM wolk@msu.edu NR 70 TC 26 Z9 28 U1 1 U2 2 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 MAY 30 PY 2003 VL 278 IS 22 BP 19939 EP 19946 DI 10.1074/jbc.M300577200 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 682EH UT WOS:000183078000049 PM 12637541 ER PT J AU Wu, RY Zhang, RG Zagnitko, O Dementieva, I Maltzev, N Watson, JD Laskowski, R Gornicki, P Joachimiak, A AF Wu, RY Zhang, RG Zagnitko, O Dementieva, I Maltzev, N Watson, JD Laskowski, R Gornicki, P Joachimiak, A TI Crystal structure of Enterococcus faecalis SlyA-like transcriptional factor SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ESCHERICHIA-COLI; PROTEINS; EXPRESSION; YERSINIA; ACTIVATION; REGULATORS; FAMILY; CLYA AB The crystal structure of a SlyA transcriptional regulator at 1.6 Angstrom resolution is presented, and structural relationships between members of the MarR/SlyA family are discussed. The SlyA family, which includes SlyA, Rap, Hor, and RovA proteins, is widely distributed in bacterial and archaeal genomes. Current evidence suggests that SlyA-like factors act as repressors, activators, and modulators of gene transcription. These proteins have been shown to up-regulate the expression of molecular chaperones, acid-resistance proteins, and cytolysin, and down-regulate several biosynthetic enzymes. The structure of SlyA from Enterococcus faecalis, determined as a part of an ongoing structural genomics initiative (www.mcsg.anl.gov), revealed the same winged helix DNA-binding motif that was recently found in the MarR repressor from Escherichia coli and the MexR repressor from Pseudomonas aeruginosa, a sequence homologue of MarR. Phylogenetic analysis of the MarR/ SlyA family suggests that Sly is placed between the SlyA and MarR subfamilies and shows significant sequence similarity to members of both subfamilies. C1 Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Mol Genet & Cell Biol, Chicago, IL 60637 USA. Wellcome Trust Genome Campus, European Bioinformat Inst, Cambridge CB10 1SD, England. RP Joachimiak, A (reprint author), Argonne Natl Lab, Biosci Div, Struct Biol Ctr, 9700 S Cass Ave,Bldg 202, Argonne, IL 60439 USA. OI Laskowski, Roman/0000-0001-5528-0087 FU NIGMS NIH HHS [P50 GM062414-02, GM62414, P50 GM062414] NR 23 TC 60 Z9 61 U1 0 U2 1 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 MAY 30 PY 2003 VL 278 IS 22 BP 20240 EP 20244 DI 10.1074/jbc.M300292200 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 682EH UT WOS:000183078000086 PM 12649270 ER PT J AU Lowry, DF Hoyt, DW Khazi, FA Bagu, J Lindsey, AG Wilson, DM AF Lowry, DF Hoyt, DW Khazi, FA Bagu, J Lindsey, AG Wilson, DM TI Investigation of the role of the histidine-aspartate pair in the human exonuclease III-like abasic endonuclease, Ape1 SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE Ape1; His-Asp pair; NMR; DNA repair; abasic ID HUMAN APURINIC/APYRIMIDINIC ENDONUCLEASE; NUCLEAR-MAGNETIC-RESONANCE; BARRIER HYDROGEN-BONDS; ACTIVE-SITE; DNA-REPAIR; MAJOR HUMAN; CRYSTAL-STRUCTURE; CATALYTIC-TRIAD; CHYMOTRYPSIN; RECOGNITION AB Hydrogen bonded histidine-aspartate (His-Asp) pairs are critical constituents in several key enzymatic reactions. To date, the role that these pairs play in catalysis is best understood in serine and trypsin-like proteases, where structural and biochemical NMR studies have revealed important pK(a) values and hydrogen bonding patterns within the catalytic pocket. However, the role of the His-Asp pair in metal-assisted catalysis is less clear. Here, we apply liquid-state NMR to investigate the role of a. critical histidine residue of apurinic endonuclease 1 (Ape1), a human DNA repair enzyme that cleaves adjacent to abasic sites in DNA using one or more divalent cations and an active-site His-Asp pair. The results of these studies suggest that the Ape1 His-Asp pair does not function as either a general base catalyst or a metal ligand. Rather, the pair likely stabilizes the pentavalent transition state necessary for phospho-transfer. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NIA, Lab Mol Gerontol, Baltimore, MD 21224 USA. RP Lowry, DF (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Hoyt, David/H-6295-2013 FU NCI NIH HHS [CA79056] NR 27 TC 22 Z9 24 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 MAY 30 PY 2003 VL 329 IS 2 BP 311 EP 322 DI 10.1016/S0022-2836(03)00382-6 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 684NT UT WOS:000183214000010 PM 12758078 ER PT J AU Blum, SA Tan, KL Bergman, RG AF Blum, SA Tan, KL Bergman, RG TI Application of physical organic methods to the investigation of organometallic reaction mechanisms SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID H OXIDATIVE ADDITION; PARENT AMIDORUTHENIUM COMPLEX; TRANSITION-METAL COMPLEXES; LIQUID RARE-GASES; BOND ACTIVATION; REDUCTIVE ELIMINATION; TRAPPING REACTIONS; ALKANE DEHYDROGENATION; IRIDIUM COMPLEXES; HYDROGEN AB For the past 75 years, physical organic chemistry has been the foundation for the elucidation of mechanisms, and the understanding of structure/activity relationships, in organic chemistry. The rational design of experiments and the critical analysis of data have been the hallmarks of this field. In this Perspective, we revisit some of the studies carried out during the past 30 years in which our group has used the tools of physical organic chemistry to investigate the mechanisms of a variety of organometallic reactions. The Perspective covers a broad spectrum of metal-mediated reactions including organic reductions, alkene, carbon monoxide and nitric oxide migratory insertion reactions, C-H bond activation, and the reactions of metal-heteroatom bonds with organic molecules. These studies, along with similar ones carried out in other groups, have demonstrated that the principles and methods of physical organic chemistry have adapted well to the study of organometallic reaction mechanisms. The understanding obtained in this way has aided the development of useful metal-mediated reactions in a wide range of areas, especially in industrial catalysis and in applications to problems in organic synthesis. C1 Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Bergman, RG (reprint author), Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. NR 73 TC 14 Z9 14 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAY 30 PY 2003 VL 68 IS 11 BP 4127 EP 4137 DI 10.1021/jo034198s PG 11 WC Chemistry, Organic SC Chemistry GA 681ZU UT WOS:000183066100001 PM 12762711 ER PT J AU Blue, BE Clayton, CE O'Connell, CL Decker, FJ Hogan, MJ Huang, C Iverson, R Joshi, C Katsouleas, TC Lu, W Marsh, KA Mori, WB Muggli, P Siemann, R Walz, D AF Blue, BE Clayton, CE O'Connell, CL Decker, FJ Hogan, MJ Huang, C Iverson, R Joshi, C Katsouleas, TC Lu, W Marsh, KA Mori, WB Muggli, P Siemann, R Walz, D TI Plasma-wakefield acceleration of an intense positron beam SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON ACCELERATION; DYNAMICS; WAVES AB Plasma wakefields are both excited and probed by propagating an intense 28.5 GeV positron beam through a 1.4 m long lithium plasma. The main body of the beam loses energy in exciting this wakefield while positrons in the back of the same beam can be accelerated by the same wakefield as it changes sign. The scaling of energy loss with plasma density as well as the energy gain seen at the highest plasma density is in excellent agreement with simulations. C1 Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ So Calif, Los Angeles, CA 90089 USA. RP Blue, BE (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RI Lu, Wei/F-2504-2016 NR 18 TC 71 Z9 71 U1 6 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 MAY 30 PY 2003 VL 90 IS 21 AR 214801 DI 10.1103/PhysRevLett.90.214801 PG 4 WC Physics, Multidisciplinary SC Physics GA 684TV UT WOS:000183223400021 PM 12786559 ER PT J AU Chen, QN Chen, SY Eyink, GL Holm, DD AF Chen, QN Chen, SY Eyink, GL Holm, DD TI Intermittency in the joint cascade of energy and helicity SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSVERSE STRUCTURE FUNCTIONS; REFINED SIMILARITY HYPOTHESIS; ISOTROPIC TURBULENCE; SHELL-MODEL; DISSIPATION; FLUX AB The statistics of the energy and helicity fluxes in isotropic turbulence are studied using high resolution direct numerical simulation. The scaling exponents of the energy flux agree with those of the transverse velocity structure functions through refined similarity hypothesis, consistent with Kraichnan's prediction. The helicity flux is even more intermittent than the energy flux. Consistent with this observation, the spatial helicity-flux structures are finer than those of energy flux and more tubelike in geometry. C1 Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Peking Univ, CCSE, Beijing 100871, Peoples R China. Peking Univ, LTCS, Beijing 100871, Peoples R China. Johns Hopkins Univ, Dept Math Sci, Baltimore, MD 21218 USA. Univ London Imperial Coll Sci Technol & Med, Dept Math, London SW7 2AZ, England. RP Chen, QN (reprint author), Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. RI Chen, Shiyi/A-3234-2010 NR 26 TC 56 Z9 56 U1 2 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 MAY 30 PY 2003 VL 90 IS 21 AR 214503 DI 10.1103/PhysRevLett.90.214503 PG 4 WC Physics, Multidisciplinary SC Physics GA 684TV UT WOS:000183223400020 PM 12786558 ER PT J AU Dobrovitski, VV De Raedt, HA Katsnelson, MI Harmon, BN AF Dobrovitski, VV De Raedt, HA Katsnelson, MI Harmon, BN TI Quantum oscillations without quantum coherence SO PHYSICAL REVIEW LETTERS LA English DT Article ID JOSEPHSON-JUNCTION; DECOHERENCE; STATES; QUBIT AB We study numerically the damping of quantum oscillations and the dynamics of the density matrix in model many-spin systems decohered by a spin bath. We show that oscillations of some density matrix elements can persist with considerable amplitude long after other elements, along with the entropy, have come close to saturation, i.e., when the system has been decohered almost completely. The oscillations exhibit very slow decay, and may be observable in experiments. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Groningen, Dept Appl Phys, NL-9747 AG Groningen, Netherlands. Univ Groningen, Ctr Mat Sci, NL-9747 AG Groningen, Netherlands. Inst Met Phys, Ekaterinburg 620219, Russia. RP Dobrovitski, VV (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Katsnelson, Mikhail/D-4359-2012 NR 21 TC 47 Z9 47 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 MAY 30 PY 2003 VL 90 IS 21 AR 210401 DI 10.1103/PhysRevLett.90.210401 PG 4 WC Physics, Multidisciplinary SC Physics GA 684TV UT WOS:000183223400002 PM 12786540 ER PT J AU Gautam, KS Kumar, S Wermeille, D Robinson, D Dhinojwala, A AF Gautam, KS Kumar, S Wermeille, D Robinson, D Dhinojwala, A TI Observation of novel liquid-crystalline phase above the bulk-melting temperature SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHAIN MOLECULES; NORMAL-ALKANES; SURFACE; DIFFRACTION; INTERFACES AB In this paper, we show that a noncrystalline but ordered smectic-like phase exists above the bulk-melting temperature (T-m) at poly(n-alkyl acrylates)-air interface. The surface ordered phase is one monolayer thick and undergoes a sharp transition from order to disorder 10degreesC above T-m for n=22. The presence of a surface phase that does not exist in the bulk has important implications in the design of thermally responsive adhesives. C1 Univ Akron, Dept Polymer Sci, Akron, OH 44325 USA. Kent State Univ, Dept Phys, Kent, OH 44240 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Argonne Natl Lab, Chicago, IL 60439 USA. RP Univ Akron, Dept Polymer Sci, Akron, OH 44325 USA. EM ali4@uakron.edu NR 16 TC 15 Z9 15 U1 0 U2 9 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 MAY 30 PY 2003 VL 90 IS 21 AR 215501 DI 10.1103/PhysRevLett.90.215501 PG 4 WC Physics, Multidisciplinary SC Physics GA 684TV UT WOS:000183223400025 PM 12786563 ER PT J AU Hsu, SC Bellan, PM AF Hsu, SC Bellan, PM TI Experimental identification of the kink instability as a poloidal flux amplification mechanism for coaxial gun spheromak formation SO PHYSICAL REVIEW LETTERS LA English DT Article ID DRIVEN SPHEROMAK; SPHEX SPHEROMAK; N=1 MODE; PLASMA; RELAXATION; SUSTAINMENT; STABILITY; JETS AB The magnetohydrodynamic kink instability is observed and identified experimentally as a poloidal flux amplification mechanism for coaxial gun spheromak formation. Plasmas in this experiment fall into three distinct regimes which depend on the peak gun current to magnetic flux ratio, with (I) low values resulting in a straight plasma column with helical magnetic field, (II) intermediate values leading to kinking of the column axis, and (III) high values leading immediately to a detached plasma. Onset of column kinking agrees quantitatively with the Kruskal-Shafranov limit, and the kink acts as a dynamo which converts toroidal to poloidal flux. Regime II clearly leads to both poloidal flux amplification and the development of a spheromak configuration. C1 CALTECH, Pasadena, CA 91125 USA. RP Hsu, SC (reprint author), Los Alamos Natl Lab, Plasma Phys Grp P 24, POB 1663, Los Alamos, NM 87545 USA. OI Hsu, Scott/0000-0002-6737-4934 NR 22 TC 80 Z9 82 U1 5 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 MAY 30 PY 2003 VL 90 IS 21 AR 215002 DI 10.1103/PhysRevLett.90.215002 PG 4 WC Physics, Multidisciplinary SC Physics GA 684TV UT WOS:000183223400024 PM 12786562 ER PT J AU Hupalo, M Schmalian, J Tringides, MC AF Hupalo, M Schmalian, J Tringides, MC TI "Devil's staircase" in Pb/Si(111) ordered phases SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMMENSURATE-INCOMMENSURATE TRANSITION; APPLIED MAGNETIC-FIELD; ISING-MODEL; MONOLAYERS; GRAPHITE; KRYPTON; CESB; PB AB With scanning tunneling microscopy we have found that ordered phases in Pb/Si(111) are one of the best examples of the "devil's staircase" phase diagram. Phases within a narrow coverage range (1.2 K(+)K(-)pi(+)pi(+)pi(-), as well as measurements of the decay modes D+ --> K(-)pi(+)pi(+)pi(+)pi(-), D-s(+) --> K(+)K(-)pi(+)pi(+)pi(-), D-s(+) --> phipi(+)pi(+)pi(-) and D+IDs+ --> pi(+)pi(+)pi(+)pi(-)pi(-). An analysis of the resonant substructure for D+ --> K(-)pi(+)pi(+)pi(+)pi(-) and D-s(+) --> K(+)K(-)pi(+)pi(+)pi(-) is included, with an indication that both decays proceed primarily through an a(1) vector resonance. (C) 2003 Published by Elsevier Science B.V. C1 Univ Colorado, Boulder, CO 80309 USA. CINVESTAV, Mexico City 07000, DF, Mexico. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Univ Calif Davis, Davis, CA 95616 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Illinois, Urbana, IL 61801 USA. Indiana Univ, Bloomington, IN 47405 USA. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu 702701, South Korea. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Milan, I-20133 Milan, Italy. Univ N Carolina, Asheville, NC 28804 USA. Dipartimento Fis Teorica & Nucl, Pavia, Italy. Ist Nazl Fis Nucl, Pavia, Italy. Univ Puerto Rico, Mayaguez, PR 00681 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Tennessee, Knoxville, TN 37996 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Segoni, I (reprint author), Univ Colorado, Boulder, CO 80309 USA. EM segoni@pizero.colorado.edu RI Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Anjos, Joao/C-8335-2013; Link, Jonathan/L-2560-2013; Benussi, Luigi/O-9684-2014; Menasce, Dario Livio/A-2168-2016; Gianini, Gabriele/M-5195-2014; OI Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Benussi, Luigi/0000-0002-2363-8889; Kutschke, Robert/0000-0001-9315-2879; Menasce, Dario Livio/0000-0002-9918-1686; Gianini, Gabriele/0000-0001-5186-0199; bianco, stefano/0000-0002-8300-4124; Kryemadhi, Abaz/0000-0002-1240-2803 NR 11 TC 6 Z9 6 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 MAY 29 PY 2003 VL 561 IS 3-4 BP 225 EP 232 DI 10.1016/S0370-2693(03)00494-5 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 680XQ UT WOS:000183005700004 ER PT J AU Benedict, DJ Parulekar, SJ Tsai, SP AF Benedict, DJ Parulekar, SJ Tsai, SP TI Esterification of lactic acid and ethanol with/without pervaporation SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID MEMBRANE REACTOR; SELECTIVE HYDROGENATION; PROPANE DEHYDROGENATION; EQUILIBRIUM SHIFT; KINETIC-MODEL; ACETIC-ACID AB Reactors coupled with membrane separation, such as pervaporation, can help enhance the conversion of reactants for thermodynamically or kinetically limited reactions via selective removal of one or more product species from the reaction mixture. An example of these reactions is esterification of carboxylic acids and alcohols. Esterification of lactic acid (C3H6O3) and ethanol (C2H5OH) is studied in well-mixed reactors with/without a solid catalyst (Amberlyst XN-1010) in this paper. Rate expressions for homogeneous and heterogeneous esterification are obtained from the experimental data using differential and integral methods. Experiments with a closed-loop system of a "batch" catalytic reactor and a pervaporation unit reveal that fractional conversions of the two reactants and yield of ethyl lactate exceeding the corresponding maximum values in a reaction-only operation are obtained by stripping of the byproduct (water). The efficacy of pervaporation-aided esterification is illustrated by the substantial gains in fractional conversion of each reactant. A protocol for recovery of ethyl lactate from pervaporation retentate is proposed. Simulations based on empirical correlations for kinetics of esterification and pervaporation reveal the trends observed in experiments. C1 IIT, Dept Chem & Environm Engn, Chicago, IL 60616 USA. Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. RP Parulekar, SJ (reprint author), IIT, Dept Chem & Environm Engn, Chicago, IL 60616 USA. NR 34 TC 52 Z9 56 U1 3 U2 26 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 MAY 28 PY 2003 VL 42 IS 11 BP 2282 EP 2291 DI 10.1021/ie020850i PG 10 WC Engineering, Chemical SC Engineering GA 681UX UT WOS:000183054900003 ER PT J AU Lu, K Jacob, J Thiyagarajan, P Conticello, VP Lynn, DG AF Lu, K Jacob, J Thiyagarajan, P Conticello, VP Lynn, DG TI Exploiting amyloid fibril lamination for nanotube self-assembly SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SOLID-STATE NMR; BETA-PROTEIN; PEPTIDE; MODEL; RIBBONS C1 Emory Univ, Dept Chem, Ctr Anal Supramol Self Assemblies, Atlanta, GA 30322 USA. Emory Univ, Dept Biol, Ctr Anal Supramol Self Assemblies, Atlanta, GA 30322 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Univ Chicago, Chicago, IL 60637 USA. RP Thiyagarajan, P (reprint author), Emory Univ, Dept Chem, Ctr Anal Supramol Self Assemblies, 1515 Pierce Dr, Atlanta, GA 30322 USA. RI ID, BioCAT/D-2459-2012; OI Conticello, Vincent/0000-0001-6940-6947 NR 24 TC 207 Z9 210 U1 4 U2 58 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 MAY 28 PY 2003 VL 125 IS 21 BP 6391 EP 6393 DI 10.1021/ja0341642 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA 681HY UT WOS:000183031800024 PM 12785778 ER PT J AU Shafirovich, V Lymar, SV AF Shafirovich, V Lymar, SV TI Spin-forbidden deprotonation of aqueous nitroxyl (HNO) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SINGLET MOLECULAR-OXYGEN; PROTON-TRANSFER; NITRIC-OXIDE; SUPEROXIDE-DISMUTASE; SOLVENT MOLECULES; NO; DEACTIVATION; CHEMISTRY; ANION; TEMPERATURE AB The first mechanistic study of a spin-forbidden proton-transfer reaction in aqueous solution is reported. Laser flash photolysis of alkaline trioxodinitrate (N2O32-, Angeli's anion) is used to generate a nitroxyl anion in its excited singlet state ((NO-)-N-1). Through rapid partitioning between protonation by water and electronic relaxation, (NO-)-N-1 produces (HNO)-H-1 (ground state, yield 96%) and (NO-)-N-3 (ground state, yield 4%), which comprise a unique conjugate acid-base couple with different ground-state multiplicities. Using the large difference between reactivities of (HNO)-H-1 and (NO-)-N-3 in the peroxynitrite-forming reaction with 3 02, the kinetics of spin-forbidden deprotonation reaction (HNO)-H-1 + OH- --> (NO-)-N-3 + H2O is investigated in H2O and D2O. Consistent with proton transfer, this reaction exhibits primary kinetic hydrogen isotope effect k(H)/k(D) = 3.1 at 298 K, which is found to be temperature-dependent. Arrhenius pre-exponential factors and activation energies of the second-order rate constant are found to be: log(A, M-1 s(-1)) = 10.0 +/- 0.2 and E-a = 30.0 +/- 1.1 kJ/mol for proton transfer and log(A, M-1 s(-1)) = 10.4 +/- 0.1 and E-a = 35.1 +/- 0.7 kJ/mol for deuteron transfer. Collectively, these data are interpreted to show that the nuclear reorganization requirements arising from the spin prohibition necessitate significant activation before spin change can take place, but the spin change itself must occur extremely rapidly. It is concluded that a synergy between the spin prohibition and the reaction energetics creates an intersystem barrier and is responsible for slowness of the spin-forbidden deprotonation of (HNO)-H-1 by OH-; the spin prohibition alone plays a minor role. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NYU, Dept Chem, New York, NY 10003 USA. NYU, Radiat & Solid State Lab, New York, NY 10003 USA. RP Lymar, SV (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. FU NIEHS NIH HHS [1R01 ES 1189-01] NR 38 TC 44 Z9 45 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 28 PY 2003 VL 125 IS 21 BP 6547 EP 6552 DI 10.1021/ja034378j PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 681HY UT WOS:000183031800040 PM 12785794 ER PT J AU Nichol, H Gakh, O O'Neill, HA Pickering, IJ Isaya, G George, GN AF Nichol, H Gakh, O O'Neill, HA Pickering, IJ Isaya, G George, GN TI Structure of frataxin iron cores: An X-ray absorption spectroscopic study SO BIOCHEMISTRY LA English DT Article ID YEAST FRATAXIN; FRIEDREICHS-ATAXIA; FINE-STRUCTURE; COORDINATION STRUCTURE; ESCHERICHIA-COLI; HORSE SPLEEN; HEME IRON; FERRITIN; HOMOLOG; DEFICIENCY AB X-ray absorption spectroscopy at the iron K-edge indicates that the iron cores of human and yeast frataxin polymers assembled in vitro are identical to each other and are similar but not identical to ferritin cores. Both frataxin polymers contain ferrihydrite, a biomineral composed of ferric oxide/hydroxide octahedra. The ferrihydrite in frataxin is less ordered than iron cores of horse spleen ferritin, having fewer face-sharing Fe-Fe interactions but similar double corner-sharing interactions. The extended X-ray absorption fine structure (EXAFS) analysis agrees with previous electron microscopy data showing that frataxin cores are composed of very small ferrihydrite crystallites. C1 Univ Saskatchewan, Dept Cell Biol & Anat, Coll Med, Saskatoon, SK S7N 5E5, Canada. Mayo Clin & Mayo Fdn, Dept Pediat & Adolescent Med, Rochester, MN 55905 USA. Mayo Clin & Mayo Fdn, Dept Biochem & Mol Biol, Rochester, MN 55905 USA. Stanford Synchrotron Radiat Lab, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Nichol, H (reprint author), Univ Saskatchewan, Dept Cell Biol & Anat, Coll Med, A315 Hlth Sci Bldg,107 Wiggins Rd, Saskatoon, SK S7N 5E5, Canada. RI George, Graham/E-3290-2013; Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 FU NIA NIH HHS [AG15709]; PHS HHS [44748] NR 53 TC 51 Z9 52 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 27 PY 2003 VL 42 IS 20 BP 5971 EP 5976 DI 10.1021/bi0270211 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 681EP UT WOS:000183024200001 PM 12755598 ER PT J AU Shiflett, PR Taylor-McCabe, KJ Michaczyk, R Silks, LA Gupta, G AF Shiflett, PR Taylor-McCabe, KJ Michaczyk, R Silks, LA Gupta, G TI Structural studies on the hairpins at the 3 ' untranslated region of an anthrax toxin gene SO BIOCHEMISTRY LA English DT Article ID TRANSCRIPTION TERMINATION; ESCHERICHIA-COLI; HYDROGEN-EXCHANGE; HIGH-RESOLUTION; INTERNAL GT; NMR-SPECTRA; DNA; MISMATCHES; PREDICTION; SEQUENCE AB Three proteins, namely, protective antigen (PA), edema factor (EF), and lethal factor (LF), encoded by the pX01 plasmid of Bacillus anthracis play a major role in the pathogenesis of target host cells. PA combines with EF and LF to form bipartite PA-EF and PA-LF toxins and facilitates intracellular delivery of EF and LF both of which cause cytotoxicity to the host. Since the level of PA is crucial to pathogenesis by anthrax toxins, it is important to understand how the host environment regulates the expression of the PA (or pagA) gene by utilizing the 5' and 3' untranslated regions (UTR). The 5' UTR sequence determines the initiation of transcription, whereas the 3' UTR sequence determines the efficient termination and stability of the transcript. Although, the role of the 5'UTR sequence of pagA has been investigated, little is known about the role of the 3' UTR. Since hairpin formation at the 3'UTR of a gene is an established mechanism for efficient termination and stability of the transcript, we carried out structural studies, including gel electrophoresis, circular dichroism, and two-dimensional nuclear magnetic resonance spectroscopy, to determine whether the 3' UTR sequences of pagA also form hairpin structures. Our results unequivocally demonstrate that both the coding and the noncoding 3' UTR sequences form stable hairpin structures. It is quite likely that the hairpins at the 3'UTR may contribute to efficient termination and stability of the pagA transcript. C1 Los Alamos Natl Lab, McClintock Resource, Grp B1, Biosci Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, NIH, Natl Stable Isotope Resource, Szilard Resource,Biosci Div,Grp B3, Los Alamos, NM 87545 USA. RP Gupta, G (reprint author), Los Alamos Natl Lab, McClintock Resource, Grp B1, Biosci Div, Mail Stop M888, Los Alamos, NM 87545 USA. OI Michalczyk, Ryszard/0000-0001-8839-6473 FU NCRR NIH HHS [RR02231] NR 43 TC 3 Z9 4 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 27 PY 2003 VL 42 IS 20 BP 6078 EP 6089 DI 10.1021/bi034128f PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 681EP UT WOS:000183024200012 PM 12755609 ER PT J AU Reeves, GD McAdams, KL Friedel, RHW O'Brien, TP AF Reeves, GD McAdams, KL Friedel, RHW O'Brien, TP TI Acceleration and loss of relativistic electrons during geomagnetic storms SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID 1997 MAGNETIC STORM; GEOSYNCHRONOUS ORBIT; INNER MAGNETOSPHERE AB We analyze the response of relativistic electrons to the 276 moderate and intense geomagnetic storms spanning the 11 years from 1989 through 2000. We find that geomagnetic storms can either increase or decrease the fluxes of relativistic electrons in the radiation belts. Surprisingly, only about half of all storms increased the fluxes of relativistic electrons, one quarter decreased the fluxes, and one quarter produced little or no change in the fluxes. We also found that the pre-storm and post-storm fluxes were highly uncorrelated suggesting that storms do not simply "pump up'' the radiation belts. We found that these conclusions were independent of the strength of the storm (minimum Dst) and independent of L-shell. In contrast, we found that higher solar wind velocities increase the probability of a large flux increase. However, for all solar wind velocities both increases and decreases were still observed. Our analysis suggests that the effect of geomagnetic storms on radiation belt fluxes are a delicate and complicated balance between the effects of particle acceleration and loss. C1 Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. Aerosp Corp, Dept Space Sci, Los Angeles, CA 90009 USA. RP Reeves, GD (reprint author), Los Alamos Natl Lab, Space & Atmospher Sci Grp, POB 1663, Los Alamos, NM 87545 USA. RI Friedel, Reiner/D-1410-2012; Reeves, Geoffrey/E-8101-2011 OI Friedel, Reiner/0000-0002-5228-0281; Reeves, Geoffrey/0000-0002-7985-8098 NR 11 TC 226 Z9 226 U1 2 U2 9 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 MAY 27 PY 2003 VL 30 IS 10 AR 1529 DI 10.1029/2002GL016513 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 686CD UT WOS:000183302200003 ER PT J AU Li, WG Hooks, DE Chiarelli, P Jiang, YB Xu, HF Wang, HL AF Li, WG Hooks, DE Chiarelli, P Jiang, YB Xu, HF Wang, HL TI Fabrication and characterization of optically active multilayer thin films based on polyaniline colloids SO LANGMUIR LA English DT Article ID CONDUCTING POLYMERS; DISPERSIONS; POLYELECTROLYTES; NANOPARTICLES; ELECTRODES; PARTICLES AB In this paper, we report the fabrication and characterization of polyaniline colloid (PANIC) multilayer thin films prepared from PANIC aqueous dispersion and a polyelectrolyte solution. Both chiral and achiral PANICs were used to fabricate multilayer thin films of up to 30 bilayers. Transmission electron microscopy, atomic force microscopy (AFM), UV-visible spectroscopy, circular dichroism, and cyclic voltammetry (CV) were used to characterize the PANICs and their multilayer thin films. CV suggests that these PANICs are more stable electrochemically than pure polyaniline (PANI). In the case of the optically active PANIC, we observe a linear increase of both the amount of the PANICs deposited and the optical activity in these thin films. Our results show that the periphery of the PANIC is mainly poly(acrylic acid), PAA, and the inner core is a mixture of PANI and PAA. Spin assembly introduces additional centrifugal forces that allow the alignment of elongated colloids parallel to the substrate surface. The AFM micrographs of a film composed of 20 PANIC/poly(diallyldimethylammonium chloride) bilayers reveal a roughness of 300 nm, equivalent to the depth of three-four colloids. This roughness level suggests that spin assembly is an ideal method for constructing colloid multilayer thin films. C1 Los Alamos Natl Lab, Biosci Div, MSJ 586, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Earth & Planetary Sci, Transmiss Electron Microscopy Lab, Albuquerque, NM 87131 USA. RP Wang, HL (reprint author), Los Alamos Natl Lab, Biosci Div, MSJ 586, Los Alamos, NM 87545 USA. NR 26 TC 25 Z9 25 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 27 PY 2003 VL 19 IS 11 BP 4639 EP 4644 DI 10.1021/la027036k PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 683FE UT WOS:000183136900019 ER PT J AU Lenhart, JL Wu, WL AF Lenhart, JL Wu, WL TI Influence of cross-link density on the thermal properties of thin polymer network films SO LANGMUIR LA English DT Article ID GLASS-TRANSITION TEMPERATURE; EPOXY NETWORKS; THICKNESS; SILICON; CONFINEMENT; EXPANSION; MOBILITY; PROBE; SIZE C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lenhart, JL (reprint author), Sandia Natl Labs, POB 5800,MS 1411, Albuquerque, NM 87185 USA. EM jllenha@sandia.gov NR 28 TC 10 Z9 10 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 27 PY 2003 VL 19 IS 11 BP 4863 EP 4865 DI 10.1021/la030018y PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 683FE UT WOS:000183136900053 ER PT J AU Sato, M Hansen, J Koch, D Lacis, A Ruedy, R Dubovik, O Holben, B Chin, M Novakov, T AF Sato, M Hansen, J Koch, D Lacis, A Ruedy, R Dubovik, O Holben, B Chin, M Novakov, T TI Global atmospheric black carbon inferred from AERONET SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE aerosols; air pollution; climate change ID SINGLE-SCATTERING ALBEDO; OPTICAL-PROPERTIES; SULFATE AEROSOLS; LIGHT-ABSORPTION; VARIABILITY; SATELLITE; MODEL; DUST; SUN AB AERONET, a network of well calibrated sunphotometers, provides data on aerosol optical depth and absorption optical depth at >250 sites around the world. The spectral range of AERONET allows discrimination between constituents that absorb most strongly in the UV region, such as soil dust and organic carbon, and the more ubiquitously absorbing black carbon (BC). AERONET locations, primarily continental, are not representative of the global mean, but they can be used to calibrate global aerosol climatologies produced by tracer transport models. We find that the amount of BC in current climatologies must be increased by a factor of 2-4 to yield best agreement with AERONET, in the approximation in which BC is externally mixed with other aerosols. The inferred climate forcing by BC, regardless of whether it is internally or externally mixed, is approximate to1 W/m(2), most of which is probably anthropogenic. This positive forcing (warming) by BC must substantially counterbalance cooling by anthropogenic reflective aerosols. Thus, especially if reflective aerosols such as sulfates are reduced, it is important to reduce BC to minimize global warming. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Earth Inst, New York, NY 10025 USA. SGT Inc, New York, NY 10025 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hansen, J (reprint author), NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RI Dubovik, Oleg/A-8235-2009; Lacis, Andrew/D-4658-2012; Chin, Mian/J-8354-2012 OI Dubovik, Oleg/0000-0003-3482-6460; NR 29 TC 136 Z9 144 U1 3 U2 23 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 MAY 27 PY 2003 VL 100 IS 11 BP 6319 EP 6324 DI 10.1073/pnas.0731897100 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 684DT UT WOS:000183190700008 PM 12746494 ER PT J AU Pretzler, G Brandl, F Stein, J Fill, E Kuba, J AF Pretzler, G Brandl, F Stein, J Fill, E Kuba, J TI High-intensity regime of x-ray generation from relativistic laser plasmas SO APPLIED PHYSICS LETTERS LA English DT Article ID SHELL IONIZATION; DENSITY PLASMAS; K-SHELL; ELECTRONS; PULSES; DIFFRACTION; DYNAMICS AB We report experiments exhibiting specific features in generating hard x rays with femtosecond laser plasmas as relativistic intensities are approached. Copper foils are irradiated with 1-J/130-fs Ti:sapphire laser pulses, and the x rays are detected with spatial resolution. The results demonstrate a dramatic reduction in the x-ray-emitting spot size at intensities around 10(19) W/cm(2), and a corresponding increase in the x-ray flux density. These findings are explained in terms of forward acceleration of electrons due to relativistic effects. (C) 2003 American Institute of Physics. C1 Max Planck Inst Quantum Opt, D-85748 Garching, Germany. Univ Munich, D-85748 Garching, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Pretzler, G (reprint author), Max Planck Inst Quantum Opt, Hans Kopfermann Str 1, D-85748 Garching, Germany. NR 22 TC 13 Z9 14 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 MAY 26 PY 2003 VL 82 IS 21 BP 3623 EP 3625 DI 10.1063/1.1577832 PG 3 WC Physics, Applied SC Physics GA 680TB UT WOS:000182993700013 ER PT J AU Gerbi, JE Voyles, PM Treacy, MMJ Gibson, JM Abelson, JR AF Gerbi, JE Voyles, PM Treacy, MMJ Gibson, JM Abelson, JR TI Increasing medium-range order in amorphous silicon with low-energy ion bombardment SO APPLIED PHYSICS LETTERS LA English DT Article ID SI; DEPOSITION AB We have observed the existence of medium-range order in amorphous silicon with the fluctuation electron microscopy technique. We hypothesize that this structure is produced during the highly nonequilibrium deposition process, during which nuclei are formed and subsequently buried. We test this hypothesis by altering the deposition kinetics during magnetron sputter deposition by bombarding the growth surface with a variable flux of low-energy (20 eV) Ar+ ions. We observe that medium - range order increases monotonically as the ion/neutral flux ratio increases. We suggest that this low-energy bombardment increases adspecie surface mobility or modifies local structural rearrangements, resulting in enhanced medium - range order via increases in the size, volume fraction, and/or internal order of the nuclei. (C) 2003 American Institute of Physics. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Univ Illinois, Coordinated Sci Lab, Urbana, IL 61801 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. NEC Res Inst, Princeton, NJ 08540 USA. RP Gerbi, JE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Gibson, Murray/E-5855-2013; OI Gibson, Murray/0000-0002-0807-6224; Voyles, Paul/0000-0001-9438-4284 NR 11 TC 30 Z9 34 U1 3 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 26 PY 2003 VL 82 IS 21 BP 3665 EP 3667 DI 10.1063/1.1578164 PG 3 WC Physics, Applied SC Physics GA 680TB UT WOS:000182993700027 ER PT J AU Novosad, V Grimsditch, M Darrouzet, J Pearson, J Bader, SD Metlushko, V Guslienko, K Otani, Y Shima, H Fukamichi, K AF Novosad, V Grimsditch, M Darrouzet, J Pearson, J Bader, SD Metlushko, V Guslienko, K Otani, Y Shima, H Fukamichi, K TI Shape effect on magnetization reversal in chains of interacting ferromagnetic elements SO APPLIED PHYSICS LETTERS LA English DT Article ID DOT ARRAYS; ANNIHILATION; NUCLEATION; VORTICES AB The magnetization reversal in the chains of submicron square- and disk-shaped Permalloy dots with lateral size of 800 nm, thickness of 50 nm and variable inter dot distance was investigated by using the magneto-optical Kerr effect technique, magnetic force microscopy and micromagnetic modeling. We have found that the particle shape strongly affects the characteristic switching fields of well-separated dots, and has almost no influence on strength of inter dot interaction in chains of magnetostatically coupled elements. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA. Seagate Res, Pittsburgh, PA 15222 USA. RIKEN Frontier Res Syst, Wako, Saitama 35610198, Japan. Tohoku Univ, Dept Mat Sci, Sendai, Miyagi 9808579, Japan. RP Novosad, V (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Novosad, Valentyn/C-2018-2014; OTANI, Yoshichika/I-5884-2012; Novosad, V /J-4843-2015 OI OTANI, Yoshichika/0000-0001-8008-1493; NR 18 TC 56 Z9 56 U1 0 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 MAY 26 PY 2003 VL 82 IS 21 BP 3716 EP 3718 DI 10.1063/1.1577808 PG 3 WC Physics, Applied SC Physics GA 680TB UT WOS:000182993700044 ER PT J AU Carena, M Ellis, J Mrenna, S Pilaftsis, A Wagner, CEM AF Carena, M Ellis, J Mrenna, S Pilaftsis, A Wagner, CEM TI Collider probes of the MSSM Higgs sector with explicit CP violation SO NUCLEAR PHYSICS B LA English DT Article ID SUPERSYMMETRIC STANDARD MODEL; ELECTRIC-DIPOLE MOMENTS; WEAK BOSON FUSION; ART. NO. 035009; HADRON COLLIDERS; FERMILAB TEVATRON; PAIR PRODUCTION; CERN LHC; CANCELLATION MECHANISM; MU(+)MU(-) COLLIDERS AB We investigate the hadron collider phenomenology of the Minimal Supersymmetric Standard Model (MSSM) with explicit CP violation for Higgs bosons that can be observed in Standard Model search channels: W/ZH(i)(--> b (b) over bar) at the Tevatron, and gg --> H-i(--> gammagamma), t (t) over barH(i)(--> b (b) over bar) and WW --> H-i(--> tau(+)tau(-)) at the LHC. Our numerical analysis is based on a benchmark scenario proposed earlier called CPX, which has been designed to showcase the effects of CP violation in the MSSM, and on several variant benchmarks. In most of the CPX parameter space, these hadron colliders will find one of the neutral MSSM Higgs bosons. However, there are small regions of parameter space in which none of the neutral Higgs bosons can be detected in the standard channels at the Tevatron and the LHC. This occurs because the neutral Higgs boson with the largest coupling to W and Z bosons decays predominantly into either two lighter Higgs bosons or a Higgs boson and a gauge boson, whilst the lighter Higgs boson has only small couplings to the W and Z bosons and the top quark. For other choices of CP-violating parameters, all three neutral Higgs bosons can have significant couplings to TV and Z bosons, producing overlapping signatures: these may or may not be distinguishable from backgrounds. The existence of these regions of parameters provides a strong motivation for a detailed experimental simulation of these channels. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Manchester, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Michigan, Randall Lab, Michigan Ctr Theoret Phys, Ann Arbor, MI 48109 USA. RP Carena, M (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. OI Mrenna, Stephen/0000-0001-8731-160X NR 82 TC 99 Z9 99 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 MAY 26 PY 2003 VL 659 IS 1-2 BP 145 EP 178 DI 10.1016/S0550-3213(03)00192-5 PG 34 WC Physics, Particles & Fields SC Physics GA 678YJ UT WOS:000182894000004 ER PT J AU Fish, RH Jaouen, G AF Fish, RH Jaouen, G TI Bioorganometallic chemistry: Structural diversity of organometallic complexes with bioligands and molecular recognition studies of several supramolecular hosts with biomolecules, alkali-metal ions, and organometallic pharmaceuticals SO ORGANOMETALLICS LA English DT Review ID (ETA-5-PENTAMETHYLCYCLOPENTADIENYL)RHODIUM AQUA COMPLEX; AQUEOUS COORDINATION CHEMISTRY; METALLOCENE ANTITUMOR AGENTS; CYCLIC TRIMER HOSTS; NONCOVALENT PI-PI; HYDROPHOBIC INTERACTIONS; MECHANISTIC IMPLICATIONS; ACID GUESTS; NUCLEOBASE; DERIVATIVES AB Bioorganometallic chemistry, a nascent area of organometallic chemistry, has recently provided significant advancements in structural diversity and molecular recognition studies. This review shows the various novel structures with bioligands of other colleagues, as well as those from our own studies. In addition, molecular recognition, the cornerstone of how biological systems operate, has now been extended to organometallic, supramolecular host molecules with biologically important guest compounds, including organometallic ionophores for selective recognition of alkali-metal ions. This host-guest molecular recognition chemistry with biologically important compounds occurs by noncovalent interactions, which encompass pi-pi, hydrophobic, and selective hydrogen bonding. The advent of organometallic pharmaceuticals has further provided unique molecular recognition/computer docking studies with hormone receptor sites that clearly delineate novel, noncovalent processes. The future looks extremely promising for bioorganometallic chemistry with regard to structural diversity and host-guest chemistry, including noncovalent interactions of organometallic pharmaceuticals with receptor site proteins to delineate mode of action. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Ecole Natl Super Chim Paris, UMR CNRS 7576, Lab Chim Organomet, F-75213 Paris 05, France. RP Fish, RH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Jaouen, Gerard/O-9927-2016 OI Jaouen, Gerard/0000-0001-5471-113X NR 45 TC 256 Z9 257 U1 3 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD MAY 26 PY 2003 VL 22 IS 11 BP 2166 EP 2177 DI 10.1021/om0300777 PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 679ME UT WOS:000182925600001 ER PT J AU Bergman, RG Cundari, TR Gillespie, AM Gunnoe, TB Harman, WD Klinckman, TR Temple, MD White, DP AF Bergman, RG Cundari, TR Gillespie, AM Gunnoe, TB Harman, WD Klinckman, TR Temple, MD White, DP TI Computational study of methane activation by TpRe(CO)(2) and CpRe(CO)(2) with a stereoelectronic comparison of cyclopentadienyl and scorpionate ligands SO ORGANOMETALLICS LA English DT Article ID H BOND ACTIVATION; TP = HYDRIDOTRIS(PYRAZOLYL)BORATE; ACETONITRILE EXCHANGE KINETICS; IRIDIUM TRIHYDRIDE COMPLEXES; TRANSITION-METAL COMPLEXES; C-H; PHOTOCHEMICAL-REACTIONS; AROMATIC-MOLECULES; DINITROGEN COMPLEX; NMR-SPECTROSCOPY AB A computational investigation of metal-based C-H activation with complexes that possess scorpionate (i.e., tris(pyrazolyl)borate) and cyclopentadienyl ligands was reported. The model tris(azo)borate ligand (Tab; [HB(N=NH)(3)](-) was created as an alternative to the parent tris(pyrazolyl)borate (Tp). The Tab ligand was found to closely reproduce the structure and energetics of Tp in Re-mediated C-H activation of methane. Relative to separated reactants oxidative addition of methane to CpRe(CO)(2) was exothermic, while the same transformations with TpRe(CO)(2) and (Tab)Re(CO)(2) were endothermic. The differences between the Tp and Cp systems were attributed primarily to steric effects. The reactivity differences between Tp and Cp drew attention to how each system would respond, sterically and electronically, to ring substitutions. TpRe(CO)(3) complexes consistently had. a broader upsilon(CO) (a measure of electronic properties) and cone angle (a measure of steric bulk) range in comparison to CpRe(CO)(3) congeners. While Cp was more sensitive to chemical modification on a per substituent basis, Tp was overall more stereoelectronically flexible. Taken together, the results of this research indicated that Tp cannot simply be considered a Cp equivalent and that the reactivity differences for Re(I) are primarily due to steric difierences between Tp and Cp. C1 Univ Memphis, Dept Chem, Memphis, TN 38152 USA. N Carolina State Univ, Dept Chem, Raleigh, NC 27695 USA. Univ N Carolina, Dept Chem, Wilmington, NC 28403 USA. AaiPharma Inc, Wilmington, NC 28405 USA. Univ Virginia, Dept Chem, Charlottesville, VA 22904 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Cundari, TR (reprint author), Univ N Texas, Dept Chem, POB 305070, Denton, TX 76203 USA. NR 92 TC 59 Z9 59 U1 3 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD MAY 26 PY 2003 VL 22 IS 11 BP 2331 EP 2337 DI 10.1021/om021048j PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 679ME UT WOS:000182925600029 ER PT J AU Pal, A Pal, T Stokes, DL Vo-Dinh, T AF Pal, A Pal, T Stokes, DL Vo-Dinh, T TI Photochemically prepared gold nanoparticles: A substrate for surface enhanced Raman scattering SO CURRENT SCIENCE LA English DT Article ID AQUEOUS TRITON X-100; METAL PARTICLES; COLLOIDAL SILVER; SPECTROSCOPY; SIZE; SERS AB Gold nanoparticles have been prepared in aqueous Triton X-100 medium using a new photochemical procedure. The characterization of the particle is made using transmission electron microscopy studies. The effects of analyte molecules such as pyridine and salt such as sodium chloride on the sol are studied. The photochemically prepared gold nanoparticles has been used successfully for surface enhanced Raman scattering studies with various types of compounds. C1 Indian Inst Technol, Dept Civil Engn, Kharagpur 721302, W Bengal, India. Indian Inst Technol, Dept Chem, Kharagpur 721302, W Bengal, India. Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring & Dev Grp, Oak Ridge, TN 37830 USA. RP Pal, A (reprint author), Indian Inst Technol, Dept Civil Engn, Kharagpur 721302, W Bengal, India. NR 28 TC 8 Z9 8 U1 1 U2 4 PU CURRENT SCIENCE ASSN PI BANGALORE PA C V RAMAN AVENUE, PO BOX 8005, BANGALORE 560 080, INDIA SN 0011-3891 J9 CURR SCI INDIA JI Curr. Sci. PD MAY 25 PY 2003 VL 84 IS 10 BP 1342 EP 1346 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 689TT UT WOS:000183509600023 ER PT J AU Boyce, BL Chen, X Peters, JO Hutchinson, JW Ritchie, RO AF Boyce, BL Chen, X Peters, JO Hutchinson, JW Ritchie, RO TI Mechanical relaxation of localized residual stresses associated with foreign object damage SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE titanium; Ti-6Al-4V; foreign-object damage; impact; residual stress; X-ray diffraction; fatigue ID HIGH-CYCLE FATIGUE; AISI-4140 STEEL; TI-6AL-4V; LIFE AB Foreign-object damage associated with the ingestion of debris into aircraft turbine engines can lead to a marked degradation in the high-cycle fatigue (HCF) life of turbine components. This degradation is generally considered to be associated with the premature initiation of fatigue cracks at or near the damage sites-, this is suspected to be due to, at least in part, the impact-induced residual stress state, which can be strongly tensile in these locations. However, recent experimental studies have shown the unexpected propensity for impact-induced fatigue crack formation at locations of compressive residual stress in the vicinity of the impact site. To address this issue, in situ and ex situ spatially-re solved X-ray diffraction and numerical modeling are utilized to show that the initial residual stress state can be strongly relaxed during the fatigue loading process. The magnitude and rate of relaxation is strongly dependent on the applied loads. For a Ti-6Al-4V turbine blade alloy, little relaxation was observed for an applied maximum stress of 325 MPa (0.35sigma(y), where sigma(y) is the yield stress), and cracks tended to form in subsurface zones of tensile residual stress away from the damage sites. In contrast, at an applied maximum stress of 500 MPa (0.54sigma(y)), equal to the smooth-bar 10(7)- cycle endurance strength, cracks tended to form at the damage sites in zones of high stress concentration that had initially been in strong compression, but had relaxed during the fatigue loading. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Div Mat Sci, Lawrence Berkeley Natl Lab, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Boyce, BL (reprint author), Sandia Natl Labs, POB 5800,MS 0889, Albuquerque, NM 87185 USA. RI Hutchinson, John/B-1221-2008; Chen, Xi/B-1539-2008; Boyce, Brad/H-5045-2012; Ritchie, Robert/A-8066-2008 OI Hutchinson, John/0000-0003-2051-3105; Chen, Xi/0000-0002-2428-180X; Boyce, Brad/0000-0001-5994-1743; Ritchie, Robert/0000-0002-0501-6998 NR 21 TC 31 Z9 33 U1 0 U2 8 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 MAY 25 PY 2003 VL 349 IS 1-2 BP 48 EP 58 AR PII S0921-5093(02)00543-9 DI 10.1016/S0921-5093(02)00543-9 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 668HK UT WOS:000182284100006 ER PT J AU Rankin, JE Hill, MR Hackel, LA AF Rankin, JE Hill, MR Hackel, LA TI The effects of process variations on residual stress in laser peened 7049 T73 aluminum alloy SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE laser peening; residual stress; surface treatment; fatigue ID FATIGUE-STRENGTH; BEHAVIOR; STRAINS; STEEL AB This paper reports measurements of the distribution of residual stress with depth from the surface in laser peened coupons made of a high-strength aluminum alloy. Residual stresses were measured using slitting (also known as the crack compliance method). Measurements were made on several coupons to: compare laser peening (LP) and shot peening (SP) residual stresses; ascertain the influence of LP parameters on residual stress; determine whether tensile residual stress existed outside the peened area; assess the variation of residual stress with in-plane position relative to the layout of the laser spots used for peening; and, determine the importance of a uniform spatial distribution of laser energy within the spot. Residual stress 0.1 mm from the surface due to LP and SP were comparable and the depth of the compressive stress for LP was far greater than for SP. Variations of most LP parameters did not significantly alter residual stress at shallow depths, but greater laser energy and larger layer overlap increased residual stress at depths between 0.2 and 0.6 mm from the surface. Residual stresses adjacent to the peened area were found to be compressive. Decreased levels of surface residual stress were found when laser spots had a non-uniform distribution of laser intensity. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Laser Sci & Technol Program, Davis, CA 95616 USA. RP Hill, MR (reprint author), Univ Calif Davis, Dept Mech & Aeronaut Engn, 1 Shields Ave, Davis, CA 95616 USA. EM mrhill@ucdavis.edu RI Hill, Michael/A-2525-2016 OI Hill, Michael/0000-0002-9168-211X NR 28 TC 40 Z9 42 U1 2 U2 16 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 MAY 25 PY 2003 VL 349 IS 1-2 BP 279 EP 291 AR PII S0921-5093(02)00811-0 DI 10.1016/S0921-5093(02)00811-0 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 668HK UT WOS:000182284100033 ER PT J AU Holm, EA Miodownik, MA Rollett, AD AF Holm, EA Miodownik, MA Rollett, AD TI On abnormal subgrain growth and the origin of recrystallization nuclei SO ACTA MATERIALIA LA English DT Article DE recrystallization; nucleation; abnormal subgrain growth; abnormal grain growth; simulation; texture evolution; Monte Carlo Potts model ID GRAIN-GROWTH; CELLULAR MICROSTRUCTURES; SINGLE-CRYSTALS; UNIFIED THEORY; SIMULATION; EVOLUTION; DISTRIBUTIONS; STABILITY; PARTICLES; RECOVERY AB Abnormal subgrain growth has been proposed as the nucleation mechanism for recrystallization. To test this hypothesis, Monte Carlo Potts model simulations of subgrain growth were performed on single-phase, strain-free subgrain structures with experimentally validated microstructure, texture, boundary character, and boundary properties. Results indicate that abnormal growth events emerge spontaneously during evolution in such systems, and abnormal subgrains behave as predicted by mean field theory. An analysis predicts the frequency of abnormal growth events as a function of local neighborhood and the boundary misorientation distribution. A recrystallization model is derived based on the abnormal subgrain growth analysis. Using data for aluminum subgrain structures, the model predicts reasonable recrystallized grain sizes as a function of von Mises strain. The extension of these results to abnormal grain growth is discussed. (C) 2003 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Kings Coll London, Dept Mech Engn, London WC2R 2LS, England. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. RP Holm, EA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM eaholm@sandia.gov RI Rollett, Anthony/A-4096-2012; Holm, Elizabeth/S-2612-2016 OI Rollett, Anthony/0000-0003-4445-2191; Holm, Elizabeth/0000-0003-3064-5769 NR 34 TC 100 Z9 106 U1 4 U2 50 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 MAY 23 PY 2003 VL 51 IS 9 BP 2701 EP 2716 DI 10.1016/S1359-6454(03)00079-X PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 679NM UT WOS:000182928900021 ER PT J AU Louie, M Hogan, C Hurley, A Simon, V Chung, C Padte, N Lamy, P Coakley, D Di Mascio, M Perelson, AS Markowitz, M AF Louie, M Hogan, C Hurley, A Simon, V Chung, C Padte, N Lamy, P Coakley, D Di Mascio, M Perelson, AS Markowitz, M TI Determining the antiviral activity of tenofovir disoproxil fumarate in treatment-naive chronically HIV-1-infected individuals SO AIDS LA English DT Article DE antiviral activity; tenofovir DF ID ANTIRETROVIRAL-EXPERIENCED PATIENTS; IMMUNODEFICIENCY-VIRUS-INFECTION; HIV-1 INFECTION; IN-VIVO; ZIDOVUDINE; ADULTS; LAMIVUDINE; EFFICACY; THERAPY; PHASE AB Objective: To assess the efficacy of tenofovir disoproxil fumarate (TDF) monotherapy by following the initial rate of decline in plasma viral load, which is a measure of the efficacy of therapy in blocking viral replication. Design: An open-label, single-site study of TDF monotherapy in 10 antiretroviral drug-naive chronically HIV-1-infected individuals. Methods: Antiviral responses were assessed at baseline and during 21 days of monotherapy with TDF by measuring plasma HIV-1 RNA levels. The rate of change in HIV-1 RNA from baseline was determined both by linear regression and by fitting to a published model. Slopes were compared with those previously determined for ritonavir monotherapy. Results: Over 21 days, mean plasma HIV-1 RNA levels in the TDF-treated patients fell 1.5 log(10) copies/ml (range, 0.7-2.0). The initial rates of decline in plasma HIV-1 RNA in the 10 TDF-treated patients and in 25 protease inhibitor-naive subjects treated with ritonavir monotherapy were nearly identical. Conclusions: The reduction in plasma HIV-1 RNA with TDF montherapy was comparable with the decline observed in previous studies of protease inhibitor monotherapy. TDF is a potent antiretroviral agent and has comparable inherent antiviral activity with that of ritonavir, a potent protease inhibitor. These data support further study of TDF-based regimens in simplified combinations of antiviral agents as initial treatment for chronic HIV-1 infection. (C) 2003 Lippincott Williams Wilkins. C1 Rockefeller Univ, Aaron Diamond AIDS Res Ctr, New York, NY 10016 USA. Gilead Sci Inc, Foster City, CA 94404 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Markowitz, M (reprint author), Rockefeller Univ, Aaron Diamond AIDS Res Ctr, 455 1st Ave, New York, NY 10016 USA. FU NCRR NIH HHS [M01-RR00102, RR0655]; NIAID NIH HHS [AI47033, AI28433, P30-AI42848] NR 24 TC 59 Z9 60 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0269-9370 J9 AIDS JI Aids PD MAY 23 PY 2003 VL 17 IS 8 BP 1151 EP 1156 DI 10.1097/01.aids.0000060362.78202.97 PG 6 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 687ZT UT WOS:000183408000006 PM 12819516 ER PT J AU Wan, SQ Luo, YQ AF Wan, SQ Luo, YQ TI Substrate regulation of soil respiration in a tallgrass prairie: Results of a clipping and shading experiment SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE carbon substrate; clipping; rhizosphere respiration; shading; tallgrass prairie; temperature sensitivity ID ORGANIC-MATTER DECOMPOSITION; MIXED HARDWOOD FOREST; TEMPERATURE SENSITIVITY; ROOT RESPIRATION; RHIZOSPHERE RESPIRATION; CO2 EFFLUX; CARBON; ECOSYSTEMS; MICROORGANISMS; ALLOCATION AB [1] Changes in soil respiration, one of the major fluxes of global carbon cycling, could significantly slow down or accelerate the increase in atmospheric CO2, with consequent feedbacks to climate change. It is critical to understand how substrate availability regulates soil respiration in projecting the response of carbon cycling to changed climate. We conducted a clipping and shading experiment for 1 year in a tallgrass prairie of the Great Plains, United States, to manipulate substrate supply to soil respiration. Our results showed that reduced substrate supply under clipping and/or shading significantly decreased soil respiration at all the timescales (diurnal, transient, and annual) irrespective of the minor concurrent changes in soil temperature and moisture. Annual mean soil respiration decreased significantly by 33, 23, and 43% for the clipping, shading, and clipping plus shading treatments, respectively. Temperature sensitivity of soil respiration decreased from 1.93 in the control plots to 1.88, 1.75, and 1.83 in the clipped, shaded, and clipped plus shaded plots, respectively. Rhizosphere respiration, respiration from decomposition of aboveground litter, and respiration from oxidation of soil organic matter and dead roots accounted for 30, 14, and 56% of annual mean soil respiration, respectively. Rhizosphere respiration was more sensitive to temperature than the other two components. Our results suggest a critical role of substrate supply in regulating soil respiration and its temperature sensitivity. C1 Univ Oklahoma, Dept Bot & Microbiol, Norman, OK 73019 USA. RP Wan, SQ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Wan, Shiqiang/B-5799-2009 NR 43 TC 122 Z9 135 U1 11 U2 72 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 MAY 23 PY 2003 VL 17 IS 2 AR 1054 DI 10.1029/2002GB001971 PG 12 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 683YH UT WOS:000183178300001 ER PT J AU Kalogeraki, VS Tornaletti, S Hanawalt, PC AF Kalogeraki, VS Tornaletti, S Hanawalt, PC TI Transcription arrest at a lesion in the transcribed DNA strand in vitro is not affected by a nearby lesion in the opposite strand SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID RNA-POLYMERASE-II; CYCLOBUTANE PYRIMIDINE DIMER; ELONGATION-FACTOR-SII; THYMINE DIMER; REPAIR; SITE; COMPLEXES; TEMPLATE; DAMAGE; ADDUCTS AB Cis-syn cyclobutane pyrimidine dimers (CPDs) are the most frequently formed lesions in UV-irradiated DNA. CPDs are repaired by the nucleotide excision repair pathway. Additionally, they are subject to transcription-coupled DNA repair. In the general model for transcription-coupled DNA repair, an RNA polymerase arrested at a lesion on the transcribed DNA strand facilitates repair by recruiting the repair machinery to the site of the lesion. Consistent with this model, transcription experiments in vitro have shown that CPDs in the transcribed DNA strand interfere with the translocation of prokaryotic and eukaryotic RNA polymerases. Here, we study the behavior of RNA polymerase when transcribing a template that contains two closely spaced lesions, one on each DNA strand. Similar DNA templates containing no CPD, or a single CPD on either the transcribed or the nontranscribed strand were used as controls. Using an in vitro transcription system with purified T7 RNA polymerase ( T7 RNAP) or rat liver RNAP II, we characterized transcript length and efficiency of transcription in vitro. We also tested the sensitivity of the arrested RNAP II-DNA-RNA ternary complex, at a CPD in the transcribed strand, to transcription factor TFIIS. The presence of a nearby CPD in the nontranscribed strand did not affect the behavior of either RNA polymerase nor did it affect the reverse translocation ability of the RNAP II-arrested complex. Our results additionally indicate that the sequence context of a CPD affects the efficiency of T7 RNAP arrest more significantly than that of RNAP II. C1 Stanford Univ, Dept Biol Sci, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Hanawalt, PC (reprint author), Stanford Univ, Dept Biol Sci, Stanford, CA 94305 USA. FU NCI NIH HHS [CA-63503, CA-77712] NR 48 TC 13 Z9 14 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 MAY 23 PY 2003 VL 278 IS 21 BP 19558 EP 19564 DI 10.1074/jbc.M301060200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 679PY UT WOS:000182932200107 PM 12646562 ER PT J AU Fries, RJ Muller, B Nonaka, C Bass, SA AF Fries, RJ Muller, B Nonaka, C Bass, SA TI Hadronization in heavy-ion collisions: Recombination and fragmentation of partons SO PHYSICAL REVIEW LETTERS LA English DT Article ID PLUS AU COLLISIONS; ROOT-S(NN)=130 GEV; TRANSVERSE-MOMENTUM; AU+AU COLLISIONS; ENERGY-LOSS; LAMBDA; FLOW AB We argue that the emission of hadrons with transverse momentum up to about 5 GeV/c in central relativistic heavy ion collisions is dominated by recombination, rather than fragmentation of partons. This mechanism provides a natural explanation for the observed constant baryon-to-meson ratio of about one and the apparent lack of a nuclear suppression of the baryon yield in this momentum range. Fragmentation becomes dominant at higher transverse momentum, but the transition point is delayed by the energy loss of fast partons in dense matter. C1 Duke Univ, Dept Phys, Durham, NC 27708 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Duke Univ, Dept Phys, Durham, NC 27708 USA. NR 28 TC 488 Z9 490 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 MAY 23 PY 2003 VL 90 IS 20 AR 202303 DI 10.1103/PhysRevLett.90.202303 PG 4 WC Physics, Multidisciplinary SC Physics GA 682WK UT WOS:000183115200011 PM 12785886 ER PT J AU Hogan, MJ Clayton, CE Huang, C Muggli, P Wang, S Blue, BE Walz, D Marsh, KA O'Connell, CL Lee, S Iverson, R Decker, FJ Raimondi, P Mori, WB Katsouleas, TC Joshi, C Siemann, RH AF Hogan, MJ Clayton, CE Huang, C Muggli, P Wang, S Blue, BE Walz, D Marsh, KA O'Connell, CL Lee, S Iverson, R Decker, FJ Raimondi, P Mori, WB Katsouleas, TC Joshi, C Siemann, RH TI Ultrarelativistic-positron-beam transport through meter-scale plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-BEAM; LENS; ACCELERATION AB We report on the first study of the dynamic transverse forces imparted to an ultrarelativistic positron beam by a long plasma in the underdense regime. Focusing of the 28.5 GeV beam is observed from time-resolved beam profiles after the 1.4 m plasma. The strength of the imparted force varies along the similar to12 ps full length of the bunch as well as with plasma density. Computer simulations substantiate the longitudinal aberration seen in the data and reveal mechanisms for emittance degradation. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ So Calif, Los Angeles, CA 90089 USA. RP Hogan, MJ (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 16 TC 31 Z9 31 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 MAY 23 PY 2003 VL 90 IS 20 AR 205002 DI 10.1103/PhysRevLett.90.205002 PG 4 WC Physics, Multidisciplinary SC Physics GA 682WK UT WOS:000183115200027 PM 12785902 ER PT J AU Kaminski, A Rosenkranz, S Fretwell, HM Li, ZZ Raffy, H Randeria, M Norman, MR Campuzano, JC AF Kaminski, A Rosenkranz, S Fretwell, HM Li, ZZ Raffy, H Randeria, M Norman, MR Campuzano, JC TI Crossover from coherent to incoherent electronic excitations in the normal state of Bi2Sr2CaCu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; OVERDOPED BI2SR2CACU2O8+DELTA; METALS; BANDS AB Angle resolved photoemission spectroscopy (ARPES) and resistivity measurements are used to explore the overdoped region of the high temperature superconductor Bi2Sr2CaCu2O8+delta. We find evidence for a new crossover line in the phase diagram between a coherent metal phase, for lower temperatures and higher doping, and an incoherent metal phase, for higher temperatures and lower doping. The former is characterized by two well-defined spectral peaks in ARPES due to coherent bilayer splitting and superlinear behavior in the resistivity, whereas the latter is characterized by a single broad spectral feature in ARPES and a linear temperature dependence of the resistivity. C1 Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Coll Swansea, Dept Phys, Swansea SA2 8PP, W Glam, Wales. Univ Paris 11, Phys Solides Lab, F-91405 Orsay, France. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. RP Kaminski, A (reprint author), Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RI Rosenkranz, Stephan/E-4672-2011; Norman, Michael/C-3644-2013 OI Rosenkranz, Stephan/0000-0002-5659-0383; NR 18 TC 63 Z9 63 U1 5 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 MAY 23 PY 2003 VL 90 IS 20 AR 207003 DI 10.1103/PhysRevLett.90.207003 PG 4 WC Physics, Multidisciplinary SC Physics GA 682WK UT WOS:000183115200042 PM 12785917 ER PT J AU Zhang, FC AF Zhang, FC TI Gossamer superconductor, Mott insulator, and resonating valence bond state in correlated electron systems SO PHYSICAL REVIEW LETTERS LA English DT Article ID MEAN FIELD-THEORY; OXIDES AB Gutzwiller variational method is applied to an effective two-dimensional Hubbard model to examine the recently proposed gossamer superconductor by Laughlin (LANL cond-mat/0209269). The ground state at half filled electron density is a gossamer superconductor for smaller intrasite Coulomb repulsion U and a Mott insulator for larger U. The gossamer superconducting state is similar to the resonating valence bond superconducting state, except that the chemical potential is approximately pinned at the mid of the two Hubbard bands away from the half filled. C1 Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. NR 24 TC 78 Z9 82 U1 1 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 MAY 23 PY 2003 VL 90 IS 20 AR 207002 DI 10.1103/PhysRevLett.90.207002 PG 4 WC Physics, Multidisciplinary SC Physics GA 682WK UT WOS:000183115200041 PM 12785916 ER PT J AU Lerch, I Wilson, R Winick, H AF Lerch, I Wilson, R Winick, H TI Supporting scientists and research in Iraq SO SCIENCE LA English DT Letter C1 NYU, New York, NY 10003 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Lerch, I (reprint author), NYU, New York, NY 10003 USA. OI Lerch, Irving/0000-0001-9623-3578 NR 0 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 MAY 23 PY 2003 VL 300 IS 5623 BP 1234 EP 1234 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 681NN UT WOS:000183042400018 PM 12764174 ER PT J AU Lucadamo, G Medlin, DL AF Lucadamo, G Medlin, DL TI Geometric origin of hexagonal close packing at a grain boundary in gold SO SCIENCE LA English DT Article ID INCOHERENT TWIN BOUNDARY; ELECTRON-MICROSCOPY; COPPER; DISSOCIATION; ENERGY; METALS; FCC AB Using electron microscopy, we identify local, intergranular regions of hexagonal close-packing at a grain boundary in gold. By analyzing the topological defects that connect this layer to the adjacent face-centered cubic grains, we explain the geometric origin of this interfacial reconstruction. We extend this analysis to predict the stacking arrangements found over a range of intergranular misorientations. These results help to unify our understanding of the defects that control the behavior of polycrystalline materials by showing how line defects that are already well understood in the bulk also can determine the atomic arrangements at grain boundaries. C1 Sandia Natl Labs, Dept Thin Film & Interface Sci, Livermore, CA 94551 USA. RP Medlin, DL (reprint author), Sandia Natl Labs, Dept Thin Film & Interface Sci, POB 969, Livermore, CA 94551 USA. NR 26 TC 29 Z9 29 U1 1 U2 36 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 MAY 23 PY 2003 VL 300 IS 5623 BP 1272 EP 1275 DI 10.1126/science.1083890 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 681NN UT WOS:000183042400043 PM 12764193 ER PT J AU Santer, BD Wigley, TML Meehl, GA Wehner, MF Mears, C Schabel, M Wentz, FJ Ammann, C Arblaster, J Bettge, T Washington, WM Taylor, KE Boyle, JS Bruggemann, W Doutriaux, C AF Santer, BD Wigley, TML Meehl, GA Wehner, MF Mears, C Schabel, M Wentz, FJ Ammann, C Arblaster, J Bettge, T Washington, WM Taylor, KE Boyle, JS Bruggemann, W Doutriaux, C TI Influence of satellite data uncertainties on the detection of externally forced climate change SO SCIENCE LA English DT Article ID TEMPERATURE TRENDS; SIMULATIONS; FINGERPRINT AB Two independent analyses of the same satellite-based radiative emissions data yield tropospheric temperature trends that differ by 0.1degreesC per decade over 1979 to 2001. The troposphere warms appreciably in one satellite data set, while the other data set shows little overall change. These satellite data uncertainties are important in studies seeking to identify human effects on climate. A model-predicted "fingerprint" of combined anthropogenic and natural effects is statistically detectable only in the satellite data set with a warming troposphere. Our findings show that claimed inconsistencies between model predictions and satellite tropospheric temperature data (and between the latter and surface data) may be an artifact of data uncertainties. C1 Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, Livermore, CA 94550 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Remote Sensing Syst, Santa Rosa, CA 95401 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. RP Santer, BD (reprint author), Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, Livermore, CA 94550 USA. RI Santer, Benjamin/F-9781-2011; Arblaster, Julie/C-1342-2010; Wigley, Tom/B-4705-2008; Taylor, Karl/F-7290-2011 OI Arblaster, Julie/0000-0002-4287-2363; Taylor, Karl/0000-0002-6491-2135 NR 30 TC 47 Z9 48 U1 2 U2 8 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 MAY 23 PY 2003 VL 300 IS 5623 BP 1280 EP 1284 DI 10.1126/science.1082393 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 681NN UT WOS:000183042400046 PM 12730497 ER PT J AU Chisholm, MF Wang, YH Lupini, AR Eres, G Puretzky, AA Brinson, B Melechko, AV Geohegan, DB Cui, HT Johnson, MP Pennycook, SJ Lowndes, DH Arepalli, S Kittrell, C Sivaram, S Kim, M Lavin, G Kono, J Hauge, R Smalley, RE AF Chisholm, MF Wang, YH Lupini, AR Eres, G Puretzky, AA Brinson, B Melechko, AV Geohegan, DB Cui, HT Johnson, MP Pennycook, SJ Lowndes, DH Arepalli, S Kittrell, C Sivaram, S Kim, M Lavin, G Kono, J Hauge, R Smalley, RE TI Comment on "Single crystals of single-walled carbon nanotubes formed by self-assembly" SO SCIENCE LA English DT Editorial Material ID ENERGY-LOSS SPECTROSCOPY; TERNARY C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Rice Univ, Ctr Nanoscale Sci & Technol, Houston, TX 77005 USA. NASA, GB Tech, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Geohegan, DB (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Melechko, Anatoli/B-8820-2008; Hauge, Robert/A-7008-2011; Arepalli, Sivaram/A-5372-2010; Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013; Eres, Gyula/C-4656-2017 OI Hauge, Robert/0000-0002-3656-0152; Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139; Eres, Gyula/0000-0003-2690-5214 NR 8 TC 1 Z9 1 U1 1 U2 14 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAY 23 PY 2003 VL 300 IS 5623 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 681NN UT WOS:000183042400024 ER PT J AU Lee, C AF Lee, C TI Generating consensus sequences from partial order multiple sequence alignment graphs SO BIOINFORMATICS LA English DT Article ID GENOME-WIDE DETECTION; HIDDEN MARKOV-MODELS; TIGR GENE INDEXES; EXPRESSED SEQUENCES; VISUALIZATION; INTEGRATION; STRATEGY; NETWORKS; TAGS; DNA AB Motivation: Consensus sequence generation is important in many kinds of sequence analysis ranging from sequence assembly to profile-based iterative search methods. However, how can a consensus be constructed when its inherent assumption-that the aligned sequences form a single linear consensus-is not true? Results: Partial Order Alignment (POA) enables construction and analysis of multiple sequence alignments as directed acyclic graphs containing complex branching structure. Here we present a dynamic programming algorithm (heaviest_bundle) for generating multiple consensus sequences from such complex alignments. The number and relationships of these consensus sequences reveals the degree of structural complexity of the source alignment. This is a powerful and general approach for analyzing and visualizing complex alignment structures, and can be applied to any alignment. We illustrate its value for analyzing expressed sequence alignments to detect alternative splicing, reconstruct full length mRNA isoform sequences from EST fragments, and separate paralog mixtures that can cause incorrect SNP predictions. C1 Univ Calif Los Angeles, DOE Ctr Genom & Proteom, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. RP Lee, C (reprint author), Univ Calif Los Angeles, DOE Ctr Genom & Proteom, Inst Mol Biol, Los Angeles, CA 90095 USA. FU NIMH NIH HHS [MH65166] NR 42 TC 28 Z9 32 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD MAY 22 PY 2003 VL 19 IS 8 BP 999 EP 1008 DI 10.1093/bioinformatics/btg109 PG 10 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 682MG UT WOS:000183095300013 PM 12761063 ER PT J AU McComas, DJ Elliott, HA Schwadron, NA Gosling, JT Skoug, RM Goldstein, BE AF McComas, DJ Elliott, HA Schwadron, NA Gosling, JT Skoug, RM Goldstein, BE TI The three-dimensional solar wind around solar maximum SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CORONAL HOLES; ULYSSES; NORTHERN AB [1] Ulysses is now completing its second solar polar orbit, dropping back down in latitude as the Sun passes through its post-maximum phase of the solar cycle. A mid-sized circumpolar coronal hole that formed around solar maximum in the northern hemisphere has persisted and produced a highly inclined CIR, which was observed from similar to70degreesN down to similar to30degreesN. We find that the speed maxima in the high-speed streams follow the same slow drop in speed with decreasing latitude observed in the large polar coronal holes around solar minimum. These results suggest a solar wind acceleration effect that is related to heliolatitude or solar rotation. We also find that the solar wind dynamic pressure is significantly lower in the post-maximum phase of this solar cycle than during the previous one, indicating that while the heliosphere is larger than near solar minimum, it should be smaller than during or after the previous maximum. C1 SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78228 USA. Los Alamos Natl Lab, Grp NIS1, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP McComas, DJ (reprint author), SW Res Inst, Space Sci & Engn Div, PO Drawer 28510, San Antonio, TX 78228 USA. NR 18 TC 134 Z9 136 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAY 22 PY 2003 VL 30 IS 10 AR 1517 DI 10.1029/2003GL017136 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 683YA UT WOS:000183177600007 ER PT J AU Gan, CK Challacombe, M AF Gan, CK Challacombe, M TI Linear scaling computation of the Fock matrix. VI. Data parallel computation of the exchange-correlation matrix SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISTRIBUTED-MEMORY ARCHITECTURES; ELECTRONIC-STRUCTURE THEORY; DENSITY-FUNCTIONAL-THEORY; INITIO QUANTUM-CHEMISTRY; FAST MULTIPOLE METHOD; NUMERICAL-INTEGRATION; BARNES-HUT; ALGORITHM; ATOMS; SIZE AB Recently, early onset linear scaling computation of the exchange-correlation matrix has been achieved using hierarchical cubature [J. Chem. Phys. 113, 10037 (2000)]. Hierarchical cubature differs from other methods in that the integration grid is adaptive and purely Cartesian, which allows for a straightforward domain decomposition in parallel computations; the volume enclosing the entire grid may be simply divided into a number of nonoverlapping boxes. In our data parallel approach, each box requires only a fraction of the total density to perform the necessary numerical integrations due to the finite extent of Gaussian-orbital basis sets. This inherent data locality may be exploited to reduce communications between processors as well as to avoid memory and copy overheads associated with data replication. Although the hierarchical cubature grid is Cartesian, naive boxing leads to irregular work loads due to strong spatial variations of the grid and the electron density. In this paper we describe equal time partitioning, which employs time measurement of the smallest sub-volumes (corresponding to the primitive cubature rule) to load balance grid-work for the next self-consistent-field iteration. After start-up from a heuristic center of mass partitioning, equal time partitioning exploits smooth variation of the density and grid between iterations to achieve load balance. With the 3-21G basis set and a medium quality grid, equal time partitioning applied to taxol (62 heavy atoms) attained a speedup of 61 out of 64 processors, while for a 110 molecule water cluster at standard density it achieved a speedup of 113 out of 128. The efficiency of equal time partitioning applied to hierarchical cubature improves as the grid work per processor increases. With a fine grid and the 6-311G(df,p) basis set, calculations on the 26 atom molecule alpha-pinene achieved a parallel efficiency better than 99% with 64 processors. For more coarse grained calculations, superlinear speedups are found to result from reduced computational complexity associated with data parallelism. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Grp T12, Los Alamos, NM 87545 USA. RP Gan, CK (reprint author), Los Alamos Natl Lab, Div Theoret, Grp T12, MS B268, Los Alamos, NM 87545 USA. RI Gan, Chee Kwan/D-7857-2011 NR 68 TC 20 Z9 20 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 2003 VL 118 IS 20 BP 9128 EP 9135 DI 10.1063/1.1568734 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 677EQ UT WOS:000182794300009 ER PT J AU Jang, SJ Silbey, RJ AF Jang, SJ Silbey, RJ TI Theory of single molecule line shapes of multichromophoric macromolecules SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MASTER EQUATION; QUANTUM DOTS; SPECTROSCOPY; COMPLEXES; DENDRIMERS; DYNAMICS; TEMPERATURE AB A theoretical framework is developed for the line shapes of the single molecule spectroscopy (SMS) of multichromophoric macromolecules by combining the Hamiltonian-based line shape theory with a kinetic equation formulation of single molecule photon counting processes. The theory allows a consistent treatment of two different line broadening mechanisms, one originating from the fast quantum dynamical degrees of freedom and the other originating from slow stochastic fluctuations that can be substantial within the SMS measurement time scale. A general expression is derived for the photon counting probability, which enables simulation of SMS line shape as an average over a renewal process and makes it possible to study the effects of radiation induced fluctuations. Then conditions are clarified under which the line shape reduces to a simple average over the distribution function of slow fluctuations. Model calculations for a bichromophoric system illustrate the subtle interplay between the fast and slow line broadening mechanisms. (C) 2003 American Institute of Physics. C1 MIT, Dept Chem, Cambridge, MA 02139 USA. RP Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM sjang@bnl.gov; silbey@mit.edu NR 35 TC 31 Z9 31 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 2003 VL 118 IS 20 BP 9312 EP 9323 DI 10.1063/1.1569239 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 677EQ UT WOS:000182794300031 ER PT J AU Jang, SJ Silbey, RJ AF Jang, SJ Silbey, RJ TI Single complex line shapes of the B850 band of LH2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LIGHT-HARVESTING COMPLEX; PHOTOSYNTHETIC PURPLE BACTERIA; RHODOPSEUDOMONAS-ACIDOPHILA STRAIN-10050; PIGMENT-PROTEIN COMPLEXES; ENERGY-TRANSFER; RHODOBACTER-SPHAEROIDES; EXCITON DELOCALIZATION; TEMPERATURE-DEPENDENCE; ANTENNA COMPLEXES; OPTICAL-SPECTRA AB For a model of the B850 band in the light harvesting complex 2 of purple bacteria, the main quantum mechanical characteristics of the single complex line shapes are studied based on the theory of the preceding paper. The model consists of single exciton states coupled to harmonic oscillator bath, with the inclusion of both static and quasistatic disorder within the exciton Hamiltonian. A closed form line shape expression is derived that can account for the non-Markovian nature of the bath for a general spectral density. The calculation of the line shape only requires the inversion of a small matrix with dimension equal to the number of exciton levels, at each frequency. For two examples of site energy modulation with definite symmetries, we examine the dependencies of the line shape on the polarization of the radiation, on the type of exciton-bath coupling, and on temperature. For a plausible example of disorder, we simulate the line shapes of the ensemble and single complex spectroscopies. Simulation of single complex line shapes suggests that the quasistatic disorder is responsible for large spectral jumps (spectral diffusion) of the lowest exciton state and make the widths of the two brightest peaks comparable. (C) 2003 American Institute of Physics. C1 MIT, Dept Chem, Cambridge, MA 02139 USA. RP Jang, SJ (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 45 TC 49 Z9 51 U1 0 U2 19 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 MAY 22 PY 2003 VL 118 IS 20 BP 9324 EP 9336 DI 10.1063/1.1569240 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 677EQ UT WOS:000182794300032 ER PT J AU McGraw, R Wu, DT AF McGraw, R Wu, DT TI Kinetic extensions of the nucleation theorem SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HOMOGENEOUS NUCLEATION; BINARY NUCLEATION; SCALING PROPERTIES; SULFURIC-ACID; RATES; WATER; CLUSTERS; NUCLEUS; MIXTURES; SYSTEMS AB Kinetic extensions of the nucleation theorem (KNT) are derived using the law of mass action and detailed balance. Results are obtained for the first- and higher-order derivatives of the nucleation rate, J, with change in supersaturation, S, in terms of the cumulants, kappa(n), of a molecular distribution of reciprocal equilibrium cluster growth rates. At constant temperature we find d ln J/d ln S=kappa(1)+1, an exact formulation of the nucleation theorem in terms of nucleation rate, and the extension d(n) ln J/d(ln S)(n)=(-1)(n+1)kappa(n) for the higher-order derivatives (ngreater than or equal to2). The case n=2 is related to the Kelvin relation. Analysis of recent water vapor nucleation rates [Wolk and Strey, J. Phys. Chem. B 105, 11683 (2001)] provides molecular-based estimates for kappa(1) and kappa(2) suitable for comparison with the predictions of classical nucleation theory. The KNT is applied to ion-induced nucleation from the gas phase, by a sequence of reversible chemical reactions, and extensions to multistep kinetics and multicomponent nucleation are presented. Nucleation theorems enable one to deduce molecular-level properties directly from macroscopic rate measurements. Here we show these properties are not those of a single cluster, the critical nucleus, as approximate forms of the theorems would suggest, but instead are averages over a weighted distribution of clusters near critical size. (C) 2003 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. RP McGraw, R (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. NR 28 TC 22 Z9 22 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 2003 VL 118 IS 20 BP 9337 EP 9347 DI 10.1063/1.1565098 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 677EQ UT WOS:000182794300033 ER PT J AU Dattelbaum, DM Itokazu, MK Iha, NYM Meyer, TJ AF Dattelbaum, DM Itokazu, MK Iha, NYM Meyer, TJ TI Mechanism of metal-to-ligand charge transfer sensitization of olefin trans-to-cis isomerization in the fac-[Re-I(phen)(CO)(3)(1,2-bpe)](+) cation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRIPLET ENERGY-TRANSFER; PHENYL-VINYL TORSIONS; EXCITATION TRANSFER; SINGLE-BOND; STILBENE; COMPLEXES; PHOTOCHEMISTRY; RHENIUM(I); SPECTROSCOPY; SPECTRA AB Near-UV, largely Re-I --> phen, bpe metal-to-ligand charge transfer (MLCT) excitation of fac-[Re-I(phen)(CO)3(trans-bpe)](+) [where phen is 1,10-phenanthroline and bpe is 1,2-bis(4-pyridyl)ethylene] in CH3CN results in isomerization at the bpe ligand and formation of fac-[Re-I(phen)(CO)(3)(cis-bpe)](+). Time-resolved absorption and infrared (TRIR) measurements reveal the existence of an intermediate with a lifetime of similar to28 ns (k = 3.6 x 10(7) s(-1)). According to the results of the transient IR measurements, the intermediate is ligand-based, presumably the olefin-localized twisted triplet (3)p. TRIR measurements in the nu(C=C) region point to a significant twisting around the C=C bond in (3)p. C1 Univ Sao Paulo, Inst Quim, BR-05508900 Sao Paulo, Brazil. Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Iha, NYM (reprint author), Univ Sao Paulo, Inst Quim, Avenida Prof Lineu Prestes,748, BR-05508900 Sao Paulo, Brazil. RI Murakami Iha, Neyde /E-1506-2012; Institute of Chemistry - USP, Dept. of Chemistry/B-8988-2012 NR 34 TC 41 Z9 41 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAY 22 PY 2003 VL 107 IS 20 BP 4092 EP 4095 DI 10.1021/jp021660o PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 679QN UT WOS:000182933600011 ER PT J AU Zhan, CG Nichols, JA Dixon, DA AF Zhan, CG Nichols, JA Dixon, DA TI Ionization potential, electron affinity, electronegativity, hardness, and electron excitation energy: Molecular properties from density functional theory orbital energies SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID EXCHANGE-CORRELATION POTENTIALS; VACUUM-ULTRAVIOLET REGION; KOHN-SHAM EIGENVALUE; Q-E SCHEME; WAVE-FUNCTIONS; ATOMIC SYSTEMS; HARTREE-FOCK; SOFT ACIDS; REACTIVITY; SPECTRA AB Representative atomic and molecular systems, including various inorganic and organic molecules with covalent and ionic bonds, have been studied by using density functional theory. The calculations were done with the commonly used exchange-correlation functional B3LYP followed by a comprehensive analysis of the calculated highest-occupied and lowest-unoccupied Kohn-Sham orbital (HOMO and LUMO) energies. The basis set dependence of the DFT results shows that the economical 6-31+G* basis set is generally sufficient for calculating the HOMO and LUMO energies (if the calculated LUMO energies are negative) for use in correlating with molecular properties. The directly calculated ionization potential (IP), electron affinity (EA), electronegativity (chi), hardness (eta), and first electron excitation energy (iota) are all in good agreement with the available experimental data. A generally applicable linear correlation relationship exists between the calculated HOMO energies and the experimental/calculated IPs. We have also found satisfactory linear correlation relationships between the calculated LUMO energies and experimental/calculated EAs (for the bound anionic states), between the calculated average HOMO/LUMO energies and chi values, between the calculated HOMO-LUMO energy gaps and eta values, and between the calculated HOMO-LUMO energy gaps and experimental/calculated first excitation energies. By using these linear correlation relationships, the calculated HOMO and LUMO energies can be employed to semiquantitatively estimate ionization potential, electron affinity, electronegativity, hardness, and first excitation energy. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dixon, DA (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, MS K1-83,POB 999, Richland, WA 99352 USA. OI Nichols, Jeffrey/0000-0001-5454-9726 NR 62 TC 409 Z9 409 U1 13 U2 109 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 MAY 22 PY 2003 VL 107 IS 20 BP 4184 EP 4195 DI 10.1021/jp0225774 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 679QN UT WOS:000182933600024 ER PT J AU Gregg, BA AF Gregg, BA TI Excitonic solar cells SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID OPEN-CIRCUIT VOLTAGE; PHOTOVOLTAIC CELLS; PHOTOELECTROCHEMICAL CELLS; POTENTIAL DISTRIBUTION; SEMICONDUCTOR-FILMS; ENERGY CONVERSION; ELECTRON-TRANSFER; PERYLENE DIIMIDE; TIO2 ELECTRODES; ORGANIC SOLIDS AB Existing types of solar cells may be divided into two distinct classes: conventional solar cells, such as silicon p-n junctions, and excitonic solar cells, XSCs. Most organic-based solar cells, including dye-sensitized solar cells, DSSCs, fall into the category of XSCs. In these cells, excitons are generated upon light absorption, and if not created directly at the heterointerface as in DSSCs, they must diffuse to it in order to photogenerate charge carriers. The distinguishing characteristic of XSCs is that charge carriers are generated and simultaneously separated across a heterointerface. In contrast, photogeneration of free electron-hole pairs occurs throughout the bulk semiconductor in conventional cells, and carrier separation upon their arrival at the junction is a subsequent process. This apparently minor mechanistic distinction results in fundamental differences in photovoltaic behavior. For example, the open circuit photovoltage V(oc) in conventional cells is limited to less than the magnitude of the band bending phi(bi); however, V(oc) in XSCs is commonly greater than phi(bi). Early work on solid-state excitonic solar cells is described as are excitonic processes in general and the use of carrier-selective (energy-selective) contacts to enhance V(oc). Then studies of DSSCs, which provide a particularly simple example of XSCs, are described. A general theoretical description applicable to all solar cells is employed to quantify the differences between conventional and excitonic cells. The key difference is the dominant importance, in XSCs, of the photoinduced chemical potential energy gradient delmu(hnu),, which was created by the interfacial exciton dissociation process. Numerical simulations demonstrate the difference in photoconversion mechanism caused solely by changing the spatial distribution of the photogenerated carriers. Finally, the similarities and differences are explored between the three major types of XSCs: organic semiconductor cells with planar interfaces, bulk heterojunction cells, and DSSCs. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Gregg, BA (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 84 TC 535 Z9 536 U1 13 U2 256 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 MAY 22 PY 2003 VL 107 IS 20 BP 4688 EP 4698 DI 10.1021/jp022507x PG 11 WC Chemistry, Physical SC Chemistry GA 679QF UT WOS:000182932900003 ER PT J AU Zhou, XJ Yoshida, T Lanzara, A Bogdanov, PV Kellar, SA Shen, KM Yang, WL Ronning, F Sasagawa, T Kakeshita, T Noda, T Eisaki, H Uchida, S Lin, CT Zhou, F Xiong, JW Ti, WX Zhao, ZX Fujimori, A Hussain, Z Shen, ZX AF Zhou, XJ Yoshida, T Lanzara, A Bogdanov, PV Kellar, SA Shen, KM Yang, WL Ronning, F Sasagawa, T Kakeshita, T Noda, T Eisaki, H Uchida, S Lin, CT Zhou, F Xiong, JW Ti, WX Zhao, ZX Fujimori, A Hussain, Z Shen, ZX TI Universal nodal Fermi velocity SO NATURE LA English DT Article ID ELECTRONIC-STRUCTURE; NORMAL-STATE; SUPERCONDUCTORS; BI2SR2CACU2O8+DELTA; LA2-XSRXCUO4; TEMPERATURE; PSEUDOGAP; PLANE; GAP; TC C1 Stanford Univ, Dept Phys Appl Phys & SSRL, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Univ Tokyo, Dept Superconduct, Bunkyo Ku, Tokyo 113, Japan. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Chinese Acad Sci, Inst Phys, Natl Lab Superconduct, Beijing 100080, Peoples R China. RP Zhou, XJ (reprint author), Stanford Univ, Dept Phys Appl Phys & SSRL, Stanford, CA 94305 USA. EM xjzhou@lbl.gov RI Shen, Kyle/B-3693-2008; Sasagawa, Takao/E-6666-2014; Yang, Wanli/D-7183-2011 OI Sasagawa, Takao/0000-0003-0149-6696; Yang, Wanli/0000-0003-0666-8063 NR 13 TC 222 Z9 225 U1 0 U2 37 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 22 PY 2003 VL 423 IS 6938 BP 398 EP 398 DI 10.1038/423398a PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 681AJ UT WOS:000183012000028 PM 12761537 ER PT J AU Link, JM Reyes, M Yager, PM Anjos, JC Bediaga, I Gobel, C Magnin, J Massafferri, A de Miranda, JM Pepe, IM dos Reis, AC Carrillo, S Casimiro, E Cuautle, E Sanchez-Hernandez, A Uribe, C Vazquez, F Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Ramirez, JE Segoni, I Wahl, M Butler, JN Cheung, HWK Chiodini, G Gaines, I Garbincius, PH Garren, LA Gottschalk, E Kasper, PH Kreymer, AE Kutschke, R Benussi, L Bianco, S Fabbri, FL Zallo, A Cawlfield, C Kim, DY Rahimi, A Wiss, J Gardner, R Kryemadhi, A Chang, CH Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Cho, K Park, H Alimonti, G Barberis, S Boschini, M Cerutti, A D'Angelo, P DiCorato, M Dini, P Edera, L Erba, S Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Moroni, L Pedrini, D Pontoglio, C Prelz, F Rovere, M Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, MM Pantea, D Pegna, DL Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Luiggi, E Mendez, H Paris, A Quinones, J Xiong, W Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M AF Link, JM Reyes, M Yager, PM Anjos, JC Bediaga, I Gobel, C Magnin, J Massafferri, A de Miranda, JM Pepe, IM dos Reis, AC Carrillo, S Casimiro, E Cuautle, E Sanchez-Hernandez, A Uribe, C Vazquez, F Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Ramirez, JE Segoni, I Wahl, M Butler, JN Cheung, HWK Chiodini, G Gaines, I Garbincius, PH Garren, LA Gottschalk, E Kasper, PH Kreymer, AE Kutschke, R Benussi, L Bianco, S Fabbri, FL Zallo, A Cawlfield, C Kim, DY Rahimi, A Wiss, J Gardner, R Kryemadhi, A Chang, CH Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Cho, K Park, H Alimonti, G Barberis, S Boschini, M Cerutti, A D'Angelo, P DiCorato, M Dini, P Edera, L Erba, S Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Moroni, L Pedrini, D Pontoglio, C Prelz, F Rovere, M Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, MM Pantea, D Pegna, DL Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Luiggi, E Mendez, H Paris, A Quinones, J Xiong, W Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M CA FOCUS Collaboration TI Measurement of the Omega(0)(c) lifetime SO PHYSICS LETTERS B LA English DT Article ID SPECTROMETER; BARYON; FOCUS AB The FOCUS experiment (FNAL-E831) has used two channels, Omega(-)pi(+) and Theta(-)K(-)pi(+)pi(+), to measure the lifetime of the Omega(c)(0) charmed baryon. From a sample of 64 +/- 14 signal events at a mass of 2.698 GeV/c(2), we measure an Omega(c)(0) lifetime of 72 +/- 11 (stat.) +/- 11 (sys.) fs, substantially improving upon the current world average. (C) 2003 Published by Elsevier Science B.V. C1 Univ Calif Davis, Davis, CA 95616 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 07000, DF, Mexico. Univ Colorado, Boulder, CO 80309 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Illinois, Urbana, IL 61801 USA. Indiana Univ, Bloomington, IN 47405 USA. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu 702701, South Korea. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Milan, Milan, Italy. Univ N Carolina, Asheville, NC 28804 USA. Dipartimento Fis Teorica & Nucl, Pavia, Italy. Ist Nazl Fis Nucl, Pavia, Italy. Univ Puerto Rico, Mayaguez, PR 00681 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Tennessee, Knoxville, TN 37996 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Link, JM (reprint author), Univ Calif Davis, Davis, CA 95616 USA. RI Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Anjos, Joao/C-8335-2013; Link, Jonathan/L-2560-2013; Benussi, Luigi/O-9684-2014; Gobel Burlamaqui de Mello, Carla /H-4721-2016; OI Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Benussi, Luigi/0000-0002-2363-8889; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Kutschke, Robert/0000-0001-9315-2879; Kryemadhi, Abaz/0000-0002-1240-2803 NR 13 TC 2 Z9 2 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 MAY 22 PY 2003 VL 561 IS 1-2 BP 41 EP 48 DI 10.1016/S0370-2693(03)00388-5 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 676PD UT WOS:000182760200005 ER PT J AU Bai, JZ Ban, Y Bian, JG Cai, X Chang, JF Chen, HF Chen, HS Chen, J Chen, J Chen, JC Chen, YB Chi, SP Chu, YP Cui, XZ Dai, YM Dai, YS Dong, LY Du, SX Du, ZZ Dunwoodie, W Fang, J Fang, SS Fu, CD Fu, HY Fu, LP Gao, CS Gao, ML Gao, YN Gong, MY Gong, WX Gu, SD Guo, YN Guo, YQ Guo, ZJ Han, SW Harris, FA He, J He, KL He, M He, X Heng, YK Hong, T Hu, HM Hu, T Huang, GS Huang, L Huang, XP Izen, JM Ji, XB Jiang, CH Jiang, XS Jin, DP Jin, S Jin, Y Jones, BD Ke, ZJ Kong, D Lai, YF Li, F Li, G Li, HH Li, J Li, JC Li, K Li, QJ Li, RB Li, RY Li, W Li, WG Li, XQ Liu, XS Liu, CF Liu, CX Liu, F Liu, F Liu, HM Liu, JB Liu, JP Liu, RG Liu, Y Liu, ZA Liu, ZX Lou, XC Lu, GR Lu, F Lu, HJ Lu, JG Lu, ZJ Luo, XL Ma, EC Ma, FC Ma, JM Malchow, R Mao, ZP Meng, XC Mo, XH Nie, J Nie, ZD Olsen, SL Paluselli, D Peng, HP Qi, ND Qian, CD Qiu, JF Rong, G Shen, DL Shen, H Shen, XY Sheng, HY Shi, F Song, LW Sun, HS Sun, SS Sun, YZ Sun, ZJ Tang, SQ Tang, X Tian, D Tian, YR Toki, W Tong, GL Varner, GS Wang, J Wang, JZ Wang, L Wang, LS Wang, M Wang, M Wang, P Wang, PL Wang, WF Wang, YF Wang, Z Wang, Z Wang, Z Wang, ZY Wei, CL Wu, N Xia, XM Xie, XX Xu, GF Xu, Y Xue, ST Yan, ML Yan, WB Yang, GA Yang, HX Yang, J Yang, SD Ye, MH Ye, YX Ying, J Yu, CS Yu, GW Yuan, CZ Yuan, JM Yuan, Y Yue, Q Zang, SL Zeng, Y Zhang, BX Zhang, BY Zhang, CC Zhang, DH Zhang, HY Zhang, J Zhang, JM Zhang, JW Zhang, LS Zhang, QJ Zhang, SQ Zhang, XY Zhang, YJ Zhang, YY Zhang, YY Zhang, ZP Zhao, DX Zhao, JW Zhao, JW Zhao, PP Zhao, WR Zhao, YB Zhao, DX Zhao, JW Zhao, JW Zhao, PP Zhao, WR Zhao, YB Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zhong, XC Zhou, BQ Zhou, GM Zhou, L Zhou, NF Zhu, KJ Zhu, QM Zhu, YC Zhu, YC Zhu, YS Zhu, ZA Zhuang, BA Zou, BS AF Bai, JZ Ban, Y Bian, JG Cai, X Chang, JF Chen, HF Chen, HS Chen, J Chen, J Chen, JC Chen, YB Chi, SP Chu, YP Cui, XZ Dai, YM Dai, YS Dong, LY Du, SX Du, ZZ Dunwoodie, W Fang, J Fang, SS Fu, CD Fu, HY Fu, LP Gao, CS Gao, ML Gao, YN Gong, MY Gong, WX Gu, SD Guo, YN Guo, YQ Guo, ZJ Han, SW Harris, FA He, J He, KL He, M He, X Heng, YK Hong, T Hu, HM Hu, T Huang, GS Huang, L Huang, XP Izen, JM Ji, XB Jiang, CH Jiang, XS Jin, DP Jin, S Jin, Y Jones, BD Ke, ZJ Kong, D Lai, YF Li, F Li, G Li, HH Li, J Li, JC Li, K Li, QJ Li, RB Li, RY Li, W Li, WG Li, XQ Liu, XS Liu, CF Liu, CX Liu, F Liu, F Liu, HM Liu, JB Liu, JP Liu, RG Liu, Y Liu, ZA Liu, ZX Lou, XC Lu, GR Lu, F Lu, HJ Lu, JG Lu, ZJ Luo, XL Ma, EC Ma, FC Ma, JM Malchow, R Mao, ZP Meng, XC Mo, XH Nie, J Nie, ZD Olsen, SL Paluselli, D Peng, HP Qi, ND Qian, CD Qiu, JF Rong, G Shen, DL Shen, H Shen, XY Sheng, HY Shi, F Song, LW Sun, HS Sun, SS Sun, YZ Sun, ZJ Tang, SQ Tang, X Tian, D Tian, YR Toki, W Tong, GL Varner, GS Wang, J Wang, JZ Wang, L Wang, LS Wang, M Wang, M Wang, P Wang, PL Wang, WF Wang, YF Wang, Z Wang, Z Wang, Z Wang, ZY Wei, CL Wu, N Xia, XM Xie, XX Xu, GF Xu, Y Xue, ST Yan, ML Yan, WB Yang, GA Yang, HX Yang, J Yang, SD Ye, MH Ye, YX Ying, J Yu, CS Yu, GW Yuan, CZ Yuan, JM Yuan, Y Yue, Q Zang, SL Zeng, Y Zhang, BX Zhang, BY Zhang, CC Zhang, DH Zhang, HY Zhang, J Zhang, JM Zhang, JW Zhang, LS Zhang, QJ Zhang, SQ Zhang, XY Zhang, YJ Zhang, YY Zhang, YY Zhang, ZP Zhao, DX Zhao, JW Zhao, JW Zhao, PP Zhao, WR Zhao, YB Zhao, DX Zhao, JW Zhao, JW Zhao, PP Zhao, WR Zhao, YB Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zhong, XC Zhou, BQ Zhou, GM Zhou, L Zhou, NF Zhu, KJ Zhu, QM Zhu, YC Zhu, YC Zhu, YS Zhu, ZA Zhuang, BA Zou, BS TI Search for lepton flavor violation process J/psi -> e mu SO PHYSICS LETTERS B LA English DT Article ID LEFT-RIGHT SYMMETRY; STANDARD MODEL; PHYSICS; DECAY; LIMIT AB Using a sample of 5.8 x 10(7) J/psi events, the Beijing Spectrometer experiment has searched for the decay J/psi --> emu. Four candidates, consistent with the estimated background, are observed, and an upper limit on the branching fraction of J/psi --> emu of 1.1 X 10(-6) at the 90% C.L. is obtained. (C) 2003 Published by Elsevier Science B.V. C1 Inst High Energy Phys, Beijing 100039, Peoples R China. China Ctr Adv Sci & Technol, Beijing 100080, Peoples R China. Colorado State Univ, Ft Collins, CO 80523 USA. Henan Normal Univ, Xinxiang 453002, Peoples R China. Huazhong Normal Univ, Wuhan 430079, Peoples R China. Hunan Univ, Changsha 410082, Peoples R China. Liaoning Univ, Shenyang 110036, Peoples R China. Nankai Univ, Tianjin 300071, Peoples R China. Peking Univ, Beijing 100871, Peoples R China. Shandong Univ, Jinan 250100, Peoples R China. Shanghai Jiao Tong Univ, Shanghai 200030, Peoples R China. Sichuan Univ, Chengdu 610064, Peoples R China. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Tsinghua Univ, Beijing 100084, Peoples R China. Univ Hawaii, Honolulu, HI 96822 USA. Univ Sci & Technol China, Anhua 230026, Peoples R China. Univ Texas, Richardson, TX 75083 USA. Wuhan Univ, Wuhan 430072, Peoples R China. Zhejiang Univ, Hangzhou 310028, Peoples R China. RP Bai, JZ (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China. EM tonggl@mail.ihep.ac.cn RI Chen, Jie/H-6210-2011; OI Yuan, Chang-Zheng/0000-0002-1652-6686 NR 24 TC 12 Z9 12 U1 0 U2 4 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 MAY 22 PY 2003 VL 561 IS 1-2 BP 49 EP 54 DI 10.1016/S0370-2693(03)00391-5 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 676PD UT WOS:000182760200006 ER PT J AU Adcox, K Adler, SS Ajitanand, NN Akiba, Y Alexander, J Aphecetche, L Arai, Y Aronson, SH Averbeck, R Awes, TC Barish, KN Barnes, PD Barrette, J Bassalleck, B Bathe, S Baublis, V Bazilevsky, A Belikov, S Bellaiche, FG Belyaev, ST Bennett, MJ Berdnikov, Y Botelho, S Brooks, ML Brown, DS Bruner, N Bucher, D Buesching, H Bumazhnov, V Bunce, G Burward-Hoy, J Butsyk, S Carey, TA Chand, P Chang, J Chang, WC Chavez, LL Chernichenko, S Chi, CY Chiba, J Chiu, M Choudhury, RK Christ, T Chujo, T Chung, MS Chung, P Cianciolo, V Cole, BA D'Enterria, DG David, G Delagrange, H Denisov, A Deshpande, A Desmond, EJ Dietzsch, O Dinesh, BV Drees, A Durum, A Dutta, D Ebisu, K Efremenko, YV El Chenawi, K En'yo, H Esumi, S Ewell, L Ferdousi, T Fields, DE Fokin, SL Fraenkel, Z Franz, A Frawley, AD Fung, SY Garpman, S Ghosh, TK Glenn, A Godoi, AL Goto, Y Greene, SV Perdekamp, MG Gupta, SK Guryn, W Gustafsson, HA Haggerty, JS Hamagaki, H Hansen, AG Kara, H Hartouni, EP Hayano, R Hayashi, N He, X Hemmick, TK Heuser, JM Hibino, M Hill, JC Ho, DS Homma, K Hong, B Hoover, A Ichihara, T Imai, K Ippolitov, MS Ishihara, M Jacak, BV Jang, WY Jia, J Johnson, BM Johnson, SC Joo, KS Kametani, S Kang, JH Kann, M Kapoor, SS Kelly, S Khachaturov, B Khanzadeev, A Kikuchi, J Kim, DJ Kim, HJ Kim, SY Kim, YG Kinnison, WW Kistenev, E Kiyomichi, A Klein-Boesing, C Klinksiek, S Kochenda, L Kochetkov, V Koehler, D Kohama, T Kotchetkov, D Kozlov, A Kroon, PJ Kurita, K Kweon, MJ Kwon, Y Kyle, GS Lacey, R Lajoie, JG Lauret, J Lebedev, A Lee, DM Leitch, MJ Li, XH Li, Z Lim, DJ Liu, MX Liu, X Liu, Z Maguire, CF Mahon, J Makdisi, YI Manko, VI Mao, Y Mark, SK Markacs, S Martinez, G Marx, MD Masaike, A Matathias, F Matsumoto, T McGaughey, PL Melnikov, E Merschmeyer, M Messer, F Messer, M Miake, Y Miller, TE Milov, A Mioduszewski, S Mischke, RE Mishra, GC Mitchell, JT Mohanty, AK Morrison, DP Moss, JM Muhlbacher, F Muniruzzaman, M Murata, J Nagamiya, S Nagasaka, Y Nagle, JL Nakada, Y Nandi, BK Newby, J Nikkinen, L Nilsson, P Nishimura, S Nyanin, AS Nystrand, J O'Brien, E Ogilvie, CA Ohnishi, H Ojha, ID Ono, M Onuchin, V Oskarsson, A Osterman, L Otterlund, I Oyama, K Paffrath, L Palounek, APT Pantuev, VS Papavassiliou, V Pate, SF Peitzmann, T Petridis, AN Pinkenburg, C Pisani, RP Pitukhin, P Plasil, F Pollack, M Pope, K Purschke, ML Ravinovich, I Read, KF Reygers, K Riabov, V Riabov, Y Rosati, M Rose, AA Ryu, SS Saito, N Sakaguchi, A Sakaguchi, T Sako, H Sakuma, T Samsonov, V Sangster, TC Santo, R Sato, HD Sato, S Sawada, S Schlei, BR Schutz, Y Semenov, V Seto, R Shea, TK Shein, I Shibata, TA Shigaki, K Shiina, T Shin, YH Sibiriak, IG Silvermyr, D Sim, KS Simon-Gillo, J Ssingh, CP Singh, V Sivertz, M Soldatov, A Soltz, RA Sorensen, S Stankus, PW Starinsky, N Steinberg, P Stenlund, E Ster, A Stoll, SP Sugioka, M Sugitate, T Sullivan, JP Sumi, Y Sun, Z Suzuki, M Takagui, EM Taketani, A Tamai, M Tanaka, KH Tanaka, Y Taniguchi, E Tannenbaum, MJ Thomas, J Thomas, JH Thomas, TL Tian, W Tojo, J Torii, H Towell, RS Tserruya, I Tsuruoka, H Tsvetkov, AA Tuli, SK Tydesjo, H Tyurin, N Ushiroda, T van Hecke, HW Velissaris, C Velkovska, J Velkovsky, M Vinogradov, AA Volkov, AM Vorobyov, A Vznuzdaev, E Wang, H Watanabe, Y White, SN Witzig, C Wohn, FK Woody, CL Xie, W Yagi, K Yokkaichi, S Young, GR Yushmanov, IE Zajc, WA Zhang, Z Zhou, S AF Adcox, K Adler, SS Ajitanand, NN Akiba, Y Alexander, J Aphecetche, L Arai, Y Aronson, SH Averbeck, R Awes, TC Barish, KN Barnes, PD Barrette, J Bassalleck, B Bathe, S Baublis, V Bazilevsky, A Belikov, S Bellaiche, FG Belyaev, ST Bennett, MJ Berdnikov, Y Botelho, S Brooks, ML Brown, DS Bruner, N Bucher, D Buesching, H Bumazhnov, V Bunce, G Burward-Hoy, J Butsyk, S Carey, TA Chand, P Chang, J Chang, WC Chavez, LL Chernichenko, S Chi, CY Chiba, J Chiu, M Choudhury, RK Christ, T Chujo, T Chung, MS Chung, P Cianciolo, V Cole, BA D'Enterria, DG David, G Delagrange, H Denisov, A Deshpande, A Desmond, EJ Dietzsch, O Dinesh, BV Drees, A Durum, A Dutta, D Ebisu, K Efremenko, YV El Chenawi, K En'yo, H Esumi, S Ewell, L Ferdousi, T Fields, DE Fokin, SL Fraenkel, Z Franz, A Frawley, AD Fung, SY Garpman, S Ghosh, TK Glenn, A Godoi, AL Goto, Y Greene, SV Perdekamp, MG Gupta, SK Guryn, W Gustafsson, HA Haggerty, JS Hamagaki, H Hansen, AG Kara, H Hartouni, EP Hayano, R Hayashi, N He, X Hemmick, TK Heuser, JM Hibino, M Hill, JC Ho, DS Homma, K Hong, B Hoover, A Ichihara, T Imai, K Ippolitov, MS Ishihara, M Jacak, BV Jang, WY Jia, J Johnson, BM Johnson, SC Joo, KS Kametani, S Kang, JH Kann, M Kapoor, SS Kelly, S Khachaturov, B Khanzadeev, A Kikuchi, J Kim, DJ Kim, HJ Kim, SY Kim, YG Kinnison, WW Kistenev, E Kiyomichi, A Klein-Boesing, C Klinksiek, S Kochenda, L Kochetkov, V Koehler, D Kohama, T Kotchetkov, D Kozlov, A Kroon, PJ Kurita, K Kweon, MJ Kwon, Y Kyle, GS Lacey, R Lajoie, JG Lauret, J Lebedev, A Lee, DM Leitch, MJ Li, XH Li, Z Lim, DJ Liu, MX Liu, X Liu, Z Maguire, CF Mahon, J Makdisi, YI Manko, VI Mao, Y Mark, SK Markacs, S Martinez, G Marx, MD Masaike, A Matathias, F Matsumoto, T McGaughey, PL Melnikov, E Merschmeyer, M Messer, F Messer, M Miake, Y Miller, TE Milov, A Mioduszewski, S Mischke, RE Mishra, GC Mitchell, JT Mohanty, AK Morrison, DP Moss, JM Muhlbacher, F Muniruzzaman, M Murata, J Nagamiya, S Nagasaka, Y Nagle, JL Nakada, Y Nandi, BK Newby, J Nikkinen, L Nilsson, P Nishimura, S Nyanin, AS Nystrand, J O'Brien, E Ogilvie, CA Ohnishi, H Ojha, ID Ono, M Onuchin, V Oskarsson, A Osterman, L Otterlund, I Oyama, K Paffrath, L Palounek, APT Pantuev, VS Papavassiliou, V Pate, SF Peitzmann, T Petridis, AN Pinkenburg, C Pisani, RP Pitukhin, P Plasil, F Pollack, M Pope, K Purschke, ML Ravinovich, I Read, KF Reygers, K Riabov, V Riabov, Y Rosati, M Rose, AA Ryu, SS Saito, N Sakaguchi, A Sakaguchi, T Sako, H Sakuma, T Samsonov, V Sangster, TC Santo, R Sato, HD Sato, S Sawada, S Schlei, BR Schutz, Y Semenov, V Seto, R Shea, TK Shein, I Shibata, TA Shigaki, K Shiina, T Shin, YH Sibiriak, IG Silvermyr, D Sim, KS Simon-Gillo, J Ssingh, CP Singh, V Sivertz, M Soldatov, A Soltz, RA Sorensen, S Stankus, PW Starinsky, N Steinberg, P Stenlund, E Ster, A Stoll, SP Sugioka, M Sugitate, T Sullivan, JP Sumi, Y Sun, Z Suzuki, M Takagui, EM Taketani, A Tamai, M Tanaka, KH Tanaka, Y Taniguchi, E Tannenbaum, MJ Thomas, J Thomas, JH Thomas, TL Tian, W Tojo, J Torii, H Towell, RS Tserruya, I Tsuruoka, H Tsvetkov, AA Tuli, SK Tydesjo, H Tyurin, N Ushiroda, T van Hecke, HW Velissaris, C Velkovska, J Velkovsky, M Vinogradov, AA Volkov, AM Vorobyov, A Vznuzdaev, E Wang, H Watanabe, Y White, SN Witzig, C Wohn, FK Woody, CL Xie, W Yagi, K Yokkaichi, S Young, GR Yushmanov, IE Zajc, WA Zhang, Z Zhou, S CA PHENIX Collaboration TI Centrality dependence of the high (PT) charged hadron suppression in Au+Au collisions at root s(NN)=130 GeV SO PHYSICS LETTERS B LA English DT Article ID LARGE-TRANSVERSE-MOMENTUM; ENERGY-LOSS; NUCLEUS COLLISIONS; GLUON PRODUCTION; AU COLLISIONS; QCD; MULTIPLICITY; QUARK AB PHENIX has measured the centrality dependence of charged hadron p(T) spectra from Au +An collisions at root(s)NN = 130 GeV The truncated mean p(T) decreases with centrality for p(T) > 2 GeV/c, indicating an apparent reduction of the contribution from hard scattering to high p(T) hadrdn production. For central collisions the yield at high p(T) is shown to be suppressed compared to binary nucleon-nucleon collision scaling of p + p, data. This suppression is monotonically increasing with centrality, but most of the change occurs below 30% centrality, i.e., for collisions with less than similar to140 participating nucleons. The observed p(T) and centrality dependence is consistent with the particle production predicted by models including hard scattering and subsequent energy loss of the scattered partons in the dense matter created in the collisions. (C) 2003 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Bhabha Atom Res Ctr, Bombay 400085, Maharashtra, India. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Banaras Hindu Univ, Dept Phys, Varanasi 221005, Uttar Pradesh, India. Univ Calif Riverside, Riverside, CA 92521 USA. CIAE, Beijing, Peoples R China. Univ Tokyo, Grad Sch Sci, Ctr Nucl Study, Tokyo 1130033, Japan. Nevis Labs, Irvington, NY 10533 USA. Columbia Univ, New York, NY 10027 USA. Florida State Univ, Tallahassee, FL 32306 USA. Georgia State Univ, Atlanta, GA 30303 USA. Hiroshima Univ, Higashihiroshima 7398526, Japan. IHEP, Protvino, Russia. Iowa State Univ, Ames, IA 50011 USA. High Energy Accelerator Res Org, KEK, Tsukuba, Ibaraki 3050801, Japan. Korea Univ, Seoul 136701, South Korea. IV Kurchatov Atom Energy Inst, Russian Res Ctr, Moscow, Russia. Kyoto Univ, Kyoto 606, Japan. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lund Univ, Dept Phys, SE-22100 Lund, Sweden. McGill Univ, Montreal, PQ H3A 2T8, Canada. Univ Munster, Inst Kernphys, D-48149 Munster, Germany. Myongji Univ, Yongin 449728, Kyonggido, South Korea. Nagasaki Inst Appl Phys, Nagasaki 8510193, Japan. Univ New Mexico, Albuquerque, NM 87131 USA. New Mexico State Univ, Las Cruces, NM 88003 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. PNPI, Gatchina, Russia. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil. Univ Nantes, Ecole Mines Nantes, SUBATECH, CNRS,1N2P3, F-44307 Nantes 3, France. St Petersburg State Tech Univ, St Petersburg, Russia. Univ Tennessee, Knoxville, TN 37996 USA. Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan. Univ Tokyo, Tokyo, Japan. Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 305, Japan. Vanderbilt Univ, Nashville, TN 37235 USA. Waseda Univ, Adv Res Inst Sci & Engn, Shinjuku Ku, Tokyo 1620044, Japan. Weizmann Inst Sci, IL-76100 Rehovot, Israel. Yonsei Univ, IPAP, Seoul 120749, South Korea. Res Inst Particle & Nucl Phys, RMKI, KFKI, Budapest, Hungary. RP Adcox, K (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM brant@bnl.gov RI seto, richard/G-8467-2011; Peitzmann, Thomas/K-2206-2012; En'yo, Hideto/B-2440-2015; Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014; Durum, Artur/C-3027-2014; Yokkaichi, Satoshi/C-6215-2017; Taketani, Atsushi/E-1803-2017; Semenov, Vitaliy/E-9584-2017 OI Peitzmann, Thomas/0000-0002-7116-899X; Hayano, Ryugo/0000-0002-1214-7806; Taketani, Atsushi/0000-0002-4776-2315; NR 33 TC 77 Z9 78 U1 6 U2 8 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 MAY 22 PY 2003 VL 561 IS 1-2 BP 82 EP 92 DI 10.1016/S0370-2693(03)00423-4 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 676PD UT WOS:000182760200010 ER PT J AU Kharzeev, D Levin, E McLerran, L AF Kharzeev, D Levin, E McLerran, L TI Parton saturation and N-part scaling of semi-hard processes in QCD SO PHYSICS LETTERS B LA English DT Article ID COLOR GLASS CONDENSATE; GLUON DISTRIBUTION-FUNCTIONS; CENTRAL AU+AU COLLISIONS; HEAVY-ION COLLISIONS; PLUS AU COLLISIONS; HIGH-DENSITY QCD; ART. NO. 022301; HIGH-ENERGY; NUCLEAR COLLISIONS; SMALL-X AB We argue that the suppression of high p(t) hadrons discovered recently in heavy ion collisions at RHIC may be a consequence of saturation in the color glass condensate. We qualitatively and semi-quantitatively describe the data, in particular, the dependence upon the number of nucleon participants. We show that if parton saturation sets in at sufficiently small energy, then in nucleus-nucleus collisions at RHIC and LHC energies the cross sections of semi-hard processes should scale approximately with the number of participants, N-part. Our results provide a possible explanation of both the absence of apparent jet quenching at SPS energies and its presence at RHIC. Under the same assumption we predict that in semi-central and central p(A) (dA) collisions at collider energies the dependence of semi-hard processes on the number of participating nucleons of the nucleus will change to similar to(N-part(A))(1/2). The forthcoming data on dA collisions will provide a crucial test of this description. (C) 2003 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Phys, Nucl Theory Grp, Upton, NY 11973 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, HEP Dept, IL-69978 Tel Aviv, Israel. DESY, Theory Grp, D-22603 Hamburg, Germany. RP Brookhaven Natl Lab, Dept Phys, Nucl Theory Grp, Upton, NY 11973 USA. EM kharzeev@bnl.gov NR 92 TC 273 Z9 273 U1 0 U2 2 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 MAY 22 PY 2003 VL 561 IS 1-2 BP 93 EP 101 DI 10.1016/S0370-2693(03)00420-9 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 676PD UT WOS:000182760200011 ER PT J AU Neuhausler, U Schneider, G Ludwig, W Meyer, MA Zschech, E Hambach, D AF Neuhausler, U Schneider, G Ludwig, W Meyer, MA Zschech, E Hambach, D TI X-ray microscopy in Zernike phase contrast mode at 4 keV photon energy with 60 nm resolution SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article; Proceedings Paper CT X-TOP 2002 Conference CY 2002 CL GRENOBLE, FRANCE ID ELECTROMIGRATION AB We report on x-ray microscopy of advanced microelectronic devices imaged in Zernike-type phase contrast mode at 4 keV photon energy. Fresnel zone plates were used as high resolution x-ray objectives providing 60 nm spatial resolution. Integrated circuit copper interconnect structures were imaged in positive as well as negative phase contrast. In both cases the phase contrast in the x-ray images is about five times higher than the pure absorption contrast. C1 European Synchrotron Radiat Facil, F-38043 Grenoble, France. Lawrence Berkeley Natl Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. AMD Saxony LLC & Co KG, D-01330 Dresden, Germany. Univ Gottingen, Inst Rontgenphys, D-37073 Gottingen, Germany. RP Neuhausler, U (reprint author), European Synchrotron Radiat Facil, BP 220, F-38043 Grenoble, France. RI Ludwig, Wolfgang/G-5823-2012 NR 11 TC 52 Z9 53 U1 2 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD MAY 21 PY 2003 VL 36 IS 10A SI SI BP A79 EP A82 AR PII S0022-3727(03)60188-9 DI 10.1088/0022-3727/36/10A/316 PG 4 WC Physics, Applied SC Physics GA 688QE UT WOS:000183446300017 ER PT J AU Lee, Y Hriljac, JA Kim, SJ Hanson, JC Vogt, T AF Lee, Y Hriljac, JA Kim, SJ Hanson, JC Vogt, T TI Pressure-induced hydration at 0.6 GPa in a synthetic gallosilicate zeolite SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NATROLITE C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Birmingham, Sch Chem Sci, Birmingham B15 2TT, W Midlands, England. Korea Inst Sci & Technol, Nano Mat Res Ctr, Seoul 130650, South Korea. Brookhaven Natl Lab, Chem Dept, Upton, NY 11973 USA. RP Lee, Y (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM yollee@bnl.gov; tvogt@bnl.gov RI Hanson, jonathan/E-3517-2010; Vogt, Thomas /A-1562-2011; Lee, Yongjae/K-6566-2016 OI Vogt, Thomas /0000-0002-4731-2787; NR 9 TC 10 Z9 10 U1 0 U2 2 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 MAY 21 PY 2003 VL 125 IS 20 BP 6036 EP 6037 DI 10.1021/ja034423n PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 680CW UT WOS:000182959600014 PM 12785816 ER PT J AU Pratt, MR Bertozzi, CR AF Pratt, MR Bertozzi, CR TI Chemoselective ligation applied to the synthesis of a biantennary N-linked glycoform of CD52 SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID LIPASE-CATALYZED ACYLATION; SOLID-PHASE SYNTHESIS; HIGH-MANNOSE CORE; CHEMOENZYMATIC SYNTHESIS; ANOMERIC SUBSTITUENTS; LEUKOCYTE CD52; GLYCOPEPTIDE; GLYCANS; UNDECASACCHARIDE; DERIVATIVES AB We report here a strategy for the synthesis of N-linked glycopeptide analogues that replace the glycosidic linkages extending from the core pentasaccharide with thioethers amenable to construction by chemoselective ligation. The key building block, a pentasaccharide-Asn analogue containing two thiol residues, was incorporated into CD52 by 9-fluorenylmethoxycarbonyl (Fmoc)-based solid-phase peptide synthesis. An undecasaccharide mimetic was then readily generated by alkylation of this glycopeptide with an N-bromoacetamido trisaccharide. The rapid assembly of a complex type N-linked glycopeptide mimetic was accomplished using this technique. C1 Univ Calif Berkeley, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Bertozzi, CR (reprint author), Univ Calif Berkeley, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. EM bertozzi@cchem.berkeley.edu NR 42 TC 46 Z9 46 U1 0 U2 2 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 MAY 21 PY 2003 VL 125 IS 20 BP 6149 EP 6159 DI 10.1021/ja029346v PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 680CW UT WOS:000182959600044 PM 12785846 ER PT J AU Nishimura, S Abrams, N Lewis, BA Halaoui, LI Mallouk, TE Benkstein, KD van de Lagemaat, J Frank, AJ AF Nishimura, S Abrams, N Lewis, BA Halaoui, LI Mallouk, TE Benkstein, KD van de Lagemaat, J Frank, AJ TI Standing wave enhancement of red absorbance and photocurrent in dye-sensitized titanium dioxide photoelectrodes coupled to photonic crystals SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SOLAR-CELLS; THIN-FILMS; DIRECT DEPOSITION; AQUEOUS-SOLUTIONS; BRAGG-REFLECTION; AIR SPHERES; TRANSMISSION; FABRICATION; EFFICIENCY; COLLOIDS AB The light harvesting efficiency of dye-sensitized photoelectrodes was enhanced by coupling a TiO2 photonic crystal layer to a conventional film of TiO2 nanoparticles. In addition to acting as a dielectric mirror, the inverse opal photonic crystal caused a significant change in dye absorbance which depended on the position of the stop band. Absorbance was suppressed at wavelengths shorter than the stop band maximum and was enhanced at longer wavelengths. This effect arises from the slow group velocity of light in the vicinity of the stop band, and the consequent localization of light intensity in the voids (to the blue) or in the dye-sensitized TiO2 (to the red) portions of the photonic crystal. By coupling a photonic crystal to a film of TiO2 nanoparticles, the short circuit photocurrent efficiency across the visible spectrum (400-750 nm) could be increased by about 26%, relative to an ordinary dye-sensitized nanocrystalline TiO2 photoelectrode. C1 Penn State Univ, Dept Chem, University Pk, PA 16802 USA. Nippon Oil Corp, Cent Tech Res Lab, Naka Ku, Yokohama, Kanagawa 2310815, Japan. Amer Univ Beirut, Beirut 110236, Lebanon. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mallouk, TE (reprint author), Penn State Univ, Dept Chem, University Pk, PA 16802 USA. RI van de Lagemaat, Jao/J-9431-2012; Mallouk, Thomas/K-7391-2012 OI Mallouk, Thomas/0000-0003-4599-4208 NR 36 TC 407 Z9 411 U1 8 U2 175 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 MAY 21 PY 2003 VL 125 IS 20 BP 6306 EP 6310 DI 10.1021/ja034650p PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 680CW UT WOS:000182959600062 PM 12785864 ER PT J AU Miller, JH Fan-Chiang, CCP Straatsma, TP Kennedy, MA AF Miller, JH Fan-Chiang, CCP Straatsma, TP Kennedy, MA TI 8-Oxoguanine enhances bending of DNA that favors binding to glycosylases SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID BASE EXCISION-REPAIR; MOLECULAR-DYNAMICS; SUBSTRATE RECOGNITION; NUCLEIC-ACIDS; FORCE-FIELD; DAMAGED DNA; URACIL; SPECIFICITY; SIMULATION; LESION AB Molecular dynamics (MD) simulations were carried out on the DNA oligonucleotide GGGAA-CAACTAG:CTAGTT GTTCCC in its native form and with guanine in the central G(19):C-6 base pair replaced by 8-oxoguanine (8oxoG). A box of explicit water molecules was used for solvation, and Na+ counterions were added to neutralize the system. The direction and magnitude of global bending were assessed by a technique used previously to analyze simulations of DNA containing a thymine dimer. The presence of 8oxoG did not greatly affect the magnitude of DNA bending; however, bending into the major groove was significantly more probable when 8oxoG replaced G(19). Crystal structures of glycosylases bound to damaged-DNA substrates consistently show a sharp bend into the major groove at the damage site. We conclude that changes in bending dynamics that assist the formation of this kink are a part of the mechanism by which glycosylases of the base excision repair pathway recognize the presence of 8oxoG in DNA. C1 Washington State Univ Tri Cities, Richland, WA 99352 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Miller, JH (reprint author), Washington State Univ Tri Cities, Richland, WA 99352 USA. NR 47 TC 29 Z9 29 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 21 PY 2003 VL 125 IS 20 BP 6331 EP 6336 DI 10.1021/ja029312n PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 680CW UT WOS:000182959600065 PM 12785867 ER PT J AU Cushman, P Heering, AH Pearson, N Elias, J Freeman, J Green, D Los, S Ronzhin, A AF Cushman, P Heering, AH Pearson, N Elias, J Freeman, J Green, D Los, S Ronzhin, A TI Crosstalk properties of the CMS HCAL hybrid photodiode SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on New Developments in Photodetection CY JUN 17-21, 2002 CL BEAUNE, FRANCE SP CEA DSM, CNRS IN2P3, Int Sci & Technol Ctr, Minist Educ Natl, Rech & Technol DE HPD; crosstalk; backscatter AB The requirements of large dynamic range, 40 MHz readout and 4 T magnetic field of the CMS Hadronic calorimeter have led to the development of a custom Hybrid PhotoDiode (HPD). In the last 5 years many improvements have been made in cooperation with DEP1 and Canberra(2) to the basic HPD concept to improve the performance. A 200-mum thick 19-channel PIN diode array with various surface treatments has been developed to ensure fast pulse behavior and low optical and capacitive crosstalk. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Minnesota, Minneapolis, MN 55455 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Heering, AH (reprint author), Univ Minnesota, Minneapolis, MN 55455 USA. NR 5 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2003 VL 504 IS 1-3 BP 62 EP 69 DI 10.1016/S0168-9002(03)00756-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AG UT WOS:000183238200013 ER PT J AU Halloin, H Von Ballmoos, P Evrard, J Skinner, GK Abrosimov, N Bastie, P Di Cocco, G George, M Hamelin, B Jean, P Knodleseder, J Laporte, P Badenes, C Laurent, P Smither, RK AF Halloin, H Von Ballmoos, P Evrard, J Skinner, GK Abrosimov, N Bastie, P Di Cocco, G George, M Hamelin, B Jean, P Knodleseder, J Laporte, P Badenes, C Laurent, P Smither, RK TI Performance of CLAIRE the first balloon-borne gamma-ray lens telescope SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on New Developments in Photodetection CY JUN 17-21, 2002 CL BEAUNE, FRANCE SP CEA DSM, CNRS IN2P3, Int Sci & Technol Ctr, Minist Educ Natl, Rech & Technol DE stratospheric flights; gamma-ray spectroscopy; instrumentation for nuclear astrophysics; crystal diffraction AB CLAIRE is a balloon-borne telescope dedicated to validating the concept of a crystal diffraction lens for nuclear astrophysics. For the first time, focusing gamma-rays enters into the domain of the high energy astrophysics. This represents a breakthrough in gamma-ray instrumentation, and will allow unprecedent sensitivities. CLAIRE's first flights occurred on June 15 2000 and on June 14 2001. Here we present its performance during the two flights in terms of pointing accuracy, background noise and estimated efficiency of the lens. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Ctr Etud Spatiale Rayonnements, F-31400 Toulouse, France. CNES, F-31401 Toulouse, France. Inst Kristallzuchtung, D-12489 Berlin, Germany. Spectrometrie Phys Lab, F-38402 St Martin Dheres, France. TESRE, I-40129 Bologna, Italy. Observ Geneva, CH-1290 Versoix, Switzerland. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. IEEC, Eidfici Nexus, E-08034 Barcelona, Spain. CEA Saclay, SAP, F-91191 Gif Sur Yvette, France. Argonne Natl Lab, Argonne, IL 60439 USA. RP Halloin, H (reprint author), Ctr Etud Spatiale Rayonnements, 9 Ave Colonel Roche, F-31400 Toulouse, France. RI laurent, philippe/E-6211-2013 NR 4 TC 11 Z9 11 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 MAY 21 PY 2003 VL 504 IS 1-3 BP 120 EP 125 DI 10.1016/S0168-9002(03)00807-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AG UT WOS:000183238200021 ER PT J AU Lopes, JAM Fernandes, LMP dos Santos, JMF Morgado, RE Conde, CAN AF Lopes, JAM Fernandes, LMP dos Santos, JMF Morgado, RE Conde, CAN TI VUV detection in large-area avalanche photodiodes as a function of temperature SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on New Developments in Photodetection CY JUN 17-21, 2002 CL BEAUNE, FRANCE SP CEA DSM, CNRS IN2P3, Int Sci & Technol Ctr, Minist Educ Natl, Rech & Technol DE LAAPD; VUV; photon-detection ID PROPORTIONAL SCINTILLATION-COUNTER; READOUT AB The response of a Peltier-cooled large-area avalanche photodiode to VUV-Iight is investigated as a function of the operation temperature. The reduction of the temperature down to 5degreesC will improve both photodiode light-level detection limit and statistical fluctuations; further temperature reduction will not result in improved performance. Optimum operation characteristics are already achieved for gains around 100 and do not depend significantly on the operation temperature. The relative variation of the gain with temperature increases with the biasing voltage presenting values that are almost a factor of two higher than for visible light detection. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Coimbra, Dept Fis, P-3004516 Coimbra, Portugal. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP dos Santos, JMF (reprint author), Univ Coimbra, Dept Fis, P-3004516 Coimbra, Portugal. RI matias-lopes, jose/H-6074-2012; dos Santos, Joaquim/B-3058-2015; Fernandes, Luis/E-2372-2011; OI matias-lopes, jose/0000-0002-6366-2963; Fernandes, Luis/0000-0002-7061-8768; Conde, Carlos/0000-0002-1387-2161; dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 12 TC 4 Z9 6 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 MAY 21 PY 2003 VL 504 IS 1-3 BP 331 EP 334 DI 10.1016/S0168-9002(03)00763-0 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AG UT WOS:000183238200063 ER PT J AU Langen, KM Binns, PJ Schreuder, AN Lennox, AJ Deluca, PM AF Langen, KM Binns, PJ Schreuder, AN Lennox, AJ Deluca, PM TI Measurement of the tissue to A-150 tissue equivalent plastic kerma ratio at two p(66)Be neutron therapy facilities SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID WATER PHANTOM; SPECTRA; BEAM; DEPTH; UNCERTAINTIES; DISTRIBUTIONS; COEFFICIENTS; IONIZATION; ENERGIES; FLUENCE AB The ICRU tissue to A-150 tissue equivalent plastic kerma ratio is needed for neutron therapy dosimetry. The current ICRU protocol for neutron dosimetry recommends using a common conversion factor of 0.95 at all high-energy neutron therapy facilities. In an effort to determine facility specific ICRU tissue to A-150 plastic kerma ratios, an experimental approach was pursued. Four low pressure proportional counters that differed in wall materials (i.e. A-150, carbon, zirconium and zirconium-oxide) were used as dosimeters and integral kerma ratios were determined directly in the clinical beam. Measurements were performed at two p(66)Be facilities: iThemba LABS near Cape Town and Fermilab near Chicago. At the iThemba facility the clinical neutron beam is routinely filtered by a flattening and hardening filter combination. The influence of beam filtration on the kerma ratio was evaluated. Using two recent gas-to-wall dose conversion factor (r(m,g) value) evaluations a mean ICRU tissue to A-150 plastic kerma ratio of 0.93 +/- 0.05 was determined for the clinical beam at iThemba LABS. The respective value for the Fermilab beam is 0.95 +/- 0.05. The experimentally determined ICRU tissue to A-150 plastic kerma ratios for the two clinical beams are in agreement with theoretical evaluations. Beam filtration reduces the kerma ratio by 3 +/- 2%. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Wisconsin, Dept Med Phys, Madison, WI 53706 USA. IThemba LABS, ZA-7129 Somerset W, South Africa. RP Langen, KM (reprint author), Univ Calif San Francisco, Dept Radiat Oncol, 1600 Divisadero St, San Francisco, CA 94143 USA. NR 29 TC 5 Z9 5 U1 0 U2 1 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 MAY 21 PY 2003 VL 48 IS 10 BP 1345 EP 1359 AR PII S0031-9155(03)56349-7 DI 10.1088/0031-9155/48/10/308 PG 15 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 693AF UT WOS:000183691900008 PM 12812451 ER PT J AU Drake, AJ Cook, KH AF Drake, AJ Cook, KH TI A search for stellar obscuration events due to dark clouds SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; dust, extinction; Galaxy : halo; ISM : clouds ID LARGE-MAGELLANIC-CLOUD; EXTREME SCATTERING EVENTS; OBSERVABLE CONSEQUENCES; SIZE DISTRIBUTION; MOLECULAR CLOUDS; COLD GAS; MATTER; STARS; EXTINCTION; HALO AB The recent detections of a large population of faint submillimeter sources, an excess halo gamma-ray background, and the extreme scattering events observed for extragalactic radio sources have been explained as being due to baryonic dark matter in the form of small, dark gas clouds. In this paper, we present the results of a search for the transient stellar obscurations such clouds are expected to cause. We examine the MACHO project light curves of 48 x 10(6) stars toward the Galactic bulge, Large Magellanic Cloud, and Small Magellanic Cloud for the presence of dark cloud extinction events. We find no evidence for a population of dark gas clouds with A(V) > 0.2 in the masses range from similar to10(-4) to 2 x 10(-2) M-., in either the Galactic disk or halo. However, it is possible that such dark cloud populations could exist if they are clustered in regions away from the observed lines of sight. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Pontificia Univ Catolica Chile, Dept Astron, Santiago 104 22, Chile. RP Drake, AJ (reprint author), Lawrence Livermore Natl Lab, 700 East Ave, Livermore, CA 94550 USA. NR 38 TC 10 Z9 10 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 MAY 20 PY 2003 VL 589 IS 1 BP 281 EP 288 DI 10.1086/374640 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 679VW UT WOS:000182943500023 ER PT J AU Anchordoqui, LA Torres, DF McCauley, TP Romero, GE Aharonian, FA AF Anchordoqui, LA Torres, DF McCauley, TP Romero, GE Aharonian, FA TI Neutrinos from accreting neutron stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; gamma rays : theory; neutrinos; X-rays : binaries; X-rays : individual (A0535+26) ID HIGH-ENERGY NEUTRINOS; GAMMA-RAY EMISSION; ATMOSPHERIC NEUTRINOS; X-RAY; OSCILLATIONS; CYGNUS-X-3; FLUX AB The magnetospheres of accreting neutron stars develop electrostatic gaps with huge potential drops. Protons and ions, accelerated in these gaps along the dipolar magnetic field lines to energies greater than 100 TeV, can impact onto the surrounding accretion disk. A proton-induced cascade develops, and charged pion decays produce nu emission. With extensive disk shower simulations using DPMJET and GEANT4, we have calculated the resulting nu spectrum. We show that the spectrum produced out of the proton beam is a power law. We use this result to propose accretion-powered X-ray binaries (with highly magnetized neutron stars) as a new population of pointlike nu sources for kilometer-scale detectors such as ICECUBE. As a particular example, we discuss the case of A0535+26. We show that ICECUBE should find A0535+26 to be a periodic nu source, one for which the formation and loss of its accretion disk can be fully detected. Finally, we comment briefly on the possibility that smaller telescopes such as AMANDA could also detect A0535+26 by folding observations with the orbital period. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. IAR, Elisa, Argentina. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. RP Anchordoqui, LA (reprint author), Northeastern Univ, Dept Phys, 110 Forsyth St, Boston, MA 02115 USA. RI Torres, Diego/O-9422-2016 OI Torres, Diego/0000-0002-1522-9065 NR 35 TC 24 Z9 24 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 MAY 20 PY 2003 VL 589 IS 1 BP 481 EP 486 DI 10.1086/374551 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 679VW UT WOS:000182943500038 ER PT J AU Hou, SS Schmidt-Rohr, K AF Hou, SS Schmidt-Rohr, K TI Polymer-clay nanocomposites from directly micellized polymer/toluene in water and their characterization by WAXD and solid-state NAM spectroscopy SO CHEMISTRY OF MATERIALS LA English DT Article ID SILICATE NANOCOMPOSITES; EMULSION POLYMERIZATION; POLY(ETHYLENE OXIDE); MELT INTERCALATION; MONTMORILLONITE; HYBRID C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Schmidt-Rohr, K (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 14 TC 15 Z9 15 U1 0 U2 5 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 MAY 20 PY 2003 VL 15 IS 10 BP 1938 EP 1940 DI 10.1021/cm020909b PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 680BJ UT WOS:000182956200004 ER PT J AU Rao, NSV Bang, YC Radhakrishnan, S Wu, QS Iyengar, SS Choo, H AF Rao, NSV Bang, YC Radhakrishnan, S Wu, QS Iyengar, SS Choo, H TI NetLets: measurement-based routing daemons for low end-to-end delays over networks SO COMPUTER COMMUNICATIONS LA English DT Article DE end-to-end delays; network instrumentation and measurements; quality of service; performance evaluation; NetLets ID QUICKEST PATH PROBLEM; ALGORITHMS; INTERNET AB Routing in the Internet is based on the best-effort mechanism, wherein the routers generally forward packets to minimize the number of hops to the destination. Furthermore, all packets of a type are treated the same independent of their size. We propose the framework of NetLets to enable the applications to send data packets to the destination with certain guarantees on the end-to-end delay. NetLets employ in situ instruments to measure the effective bandwidth and propagation delays on the links, and compute the paths with minimum measured end-to-end delay for data packets of various sizes. Based on experiments over local area networks, the paths selected by NetLets indeed achieve the minimum end-to-end delay, and our method outperformed the best-effort mechanism based on the hop count. We also describe an implementation of NetLets over the Internet to illustrate their viability for wide-area networks. (C) 2002 Elsevier Science B.V. All rights reserved. C1 EIRI, Network Technol Lab, Routing Protocol Team, Taejon, South Korea. Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. Univ Oklahoma, Sch Comp Sci, Norman, OK 73019 USA. Louisiana State Univ, Dept Comp Sci, Baton Rouge, LA 70803 USA. Sungkyunkwan Univ, Sch ICE, Suwon, South Korea. RP EIRI, Network Technol Lab, Routing Protocol Team, Taejon, South Korea. EM raons@ornl.gov; ybang@kpu.ac.kr OI Rao, Nageswara/0000-0002-3408-5941 NR 19 TC 4 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 EI 1873-703X J9 COMPUT COMMUN JI Comput. Commun. PD MAY 20 PY 2003 VL 26 IS 8 BP 834 EP 844 AR PII S0140-3664(02)00217-7 DI 10.1016/S0140-3664(02)00217-7 PG 11 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 674JN UT WOS:000182633800005 ER PT J AU Ji, SH Yeo, IW Lee, KK Glass, RJ AF Ji, SH Yeo, IW Lee, KK Glass, RJ TI Influence of ambient groundwater flow on DNAPL migration in a fracture network: Experiments and simulations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INVASION PERCOLATION; GEOLOGIC MEDIA; PHASE LIQUIDS; POROUS-MEDIA; DISSOLUTION; MODEL; ROCK AB [1] We consider the influence of ambient groundwater flow on the migration of DNAPL within a fracture network. In context of a modified invasion percolation (MIP) growth algorithm, we formulate a mechanistic model that includes capillary and gravity forces as well as viscous forces within the DNAPL and the ambient groundwater. The MIP model is verified against laboratory experiments, which show good agreement in DNAPL migration path through a two-dimensional fracture network. The results of both simulations and laboratory experiments suggest that ambient groundwater flow can be a significant factor controlling DNAPL migration path, velocity, and channeling pattern in a fracture network. C1 Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151747, South Korea. Sandia Natl Labs, Flow Visualizat & Proc Lab, Albuquerque, NM 87185 USA. RP Ji, SH (reprint author), Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151747, South Korea. NR 17 TC 5 Z9 5 U1 0 U2 3 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 MAY 20 PY 2003 VL 30 IS 10 AR 1504 DI 10.1029/2003GL017064 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 683XY UT WOS:000183177400004 ER PT J AU Fattebert, JL Gygi, F AF Fattebert, JL Gygi, F TI First-principles molecular dynamics simulations in a continuum solvent SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article DE Car-Parrinello molecular dynamics; density functional theory; continuum solvation model ID GENERALIZED GRADIENT APPROXIMATION; DENSITY-FUNCTIONAL THEORY; MODEL; WATER; COMPUTATION; POTENTIALS; FORCES; ENERGY AB A new continuum solvation model for density functional theory first-principles simulations is presented in the context of plane wave Car-Parrinello molecular dynamics. The Poisson problem-with dielectric function representing the solvent effects-is solved by a compact finite difference method on a regular grid. The smoothness of the solute-solvent transition, and the density-based solute cavity, provide good numerical properties to the model and allow for total energy calculations, reaction barriers calculations, and energy-conserving molecular dynamics. (C) 2003 Wiley Periodicals, Inc. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-561, Livermore, CA 94551 USA. EM fattebert1@llnl.gov NR 36 TC 56 Z9 56 U1 2 U2 16 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0020-7608 EI 1097-461X J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD MAY 20 PY 2003 VL 93 IS 2 BP 139 EP 147 DI 10.1002/qua.10548 PG 9 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 670DJ UT WOS:000182391900009 ER PT J AU Elman, HC Howle, VE Shadid, JN Tuminaro, RS AF Elman, HC Howle, VE Shadid, JN Tuminaro, RS TI A parallel block multi-level preconditioner for the 3D incompressible Navier-Stokes equations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Navier-Stokes; preconditioner; approximate block factorization; approximate schur complement; convention-diffusion operator; multi-level; algebraic multigrid ID SEMIIMPLICIT PROJECTION METHODS; FRACTIONAL STEP METHOD; SMOOTHED AGGREGATION; LINEAR-SYSTEMS; FLUID-FLOW; CONVERGENCE; MASS; PERFORMANCE; ALGORITHMS; STABILITY AB The development of robust and efficient algorithms for both steady-state simulations and fully implicit time integration of the Navier-Stokes equations is an active research topic. To be effective, the linear subproblems generated by these methods require solution techniques that exhibit robust and rapid convergence. In particular, they should be insensitive to parameters in the problem such as mesh size, time step, and Reynolds number. In this context, we explore a parallel preconditioner based on a block factorization of the coefficient matrix generated in an Oseen nonlinear iteration for the primitive variable formulation of the system. The key to this preconditioner is the approximation of a certain Schur complement operator by a technique first proposed by Kay, Loghin, and Wathen [SIAM J. Sci. Comput., 2002] and Silvester, Elman, Kay, and Wathen [J. Comput. Appl. Math. 128 (2001) 26 1]. The resulting operator entails subsidiary computations (solutions of pressure Poisson and convection-diffusion subproblems) that are similar to those required for decoupled solution methods; however, in this case these solutions are applied as preconditioners to the coupled Oseen system. One important aspect of this approach is that the convection-diffusion and Poisson subproblems are significantly easier to solve than the entire coupled system, and a solver can be built using tools developed for the subproblems. In this paper, we apply smoothed aggregation algebraic multigrid to both subproblems. Previous work has focused on demonstrating the optimality of these preconditioners with respect to mesh size on serial, two-dimensional, steady-state computations employing geometric multi-grid methods; we focus on extending these methods to large-scale, parallel, three-dimensional, transient and steady-state simulations employing algebraic multigrid (AMG) methods. Our results display nearly optimal convergence rates for steady-state solutions as well as for transient solutions over a wide range of CFL numbers on the two-dimensional and three-dimensional lid-driven cavity problem. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. Univ Maryland, Inst Adv Comp Studies, College Pk, MD 20742 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Shadid, JN (reprint author), Sandia Natl Labs, POB 5800,MS 1111, Albuquerque, NM 87185 USA. RI Elman, Howard/F-6517-2011 OI Elman, Howard/0000-0002-8886-9901 NR 64 TC 30 Z9 30 U1 0 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD MAY 20 PY 2003 VL 187 IS 2 BP 504 EP 523 DI 10.1016/S0021-9991(03)00121-9 PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 682AH UT WOS:000183067200007 ER PT J AU Chen, J Gu, BH Royer, RA Burgos, WD AF Chen, J Gu, BH Royer, RA Burgos, WD TI The roles of natural organic matter in chemical and microbial reduction of ferric iron SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE humic substances; Fe(III) reduction; Shewanella putrefaciens; NOM oxidation capacity ID HUMIC SUBSTANCES; DISSIMILATORY REDUCTION; IRON(III) REDUCTION; ELECTRON-ACCEPTORS; REDOX PROPERTIES; ACID; BACTERIUM; OXIDE; ENHANCEMENT; ADSORPTION AB Although natural organic matter (NOM) is known to be redox reactive, the roles and effectiveness of specific functional groups of NOM in metal reduction are still a subject of intense investigation. This study entails the investigation of the Fe(III) reduction kinetics and capacity by three fractionated NOM subcomponents in the presence or absence of the dissimilatory metal reducing bacterium Shewanella putrefaciens CN32. Results indicate that NOM was able to reduce Fe(III) abiotically; the reduction was pH-dependent and varied greatly with different fractions of NOM. The polyphenolic-rich NOM-PP fraction exhibited the highest reactivity and oxidation capacity at a low pH (< 4) as compared with the carbohydrate-rich NOM-CH fraction and a soil humic acid (soil HA) in reducing Fe(III). However, at a pH > 4, soil HA showed a relatively high oxidation capacity, probably resulting from its conformational. and solubility changes with an increased solution pH. In the presence of S. putrefaciens CN32, all NOM fractions were found to enhance the microbial reduction of Fe(III) under anaerobic, circumneutral pH conditions. Soil HA was found to be particularly effective in mediating the bioreduction of Fe(III) as compared with the NOM-PP or NOM-CH fractions. NOM-CH was the least effective because it was depleted in both aromatic and polyphenolic organic contents. However, because both soil HA and NOM-PP contain relatively high amounts of aromatic and phenolic compounds, results may indicate that low-molecular-weight polyphenolic organics in NOM-PP were less effective in mediating the bioreduction of Fe(III) at circumneutral pH than the high-molecular-weight polycondensed, conjugated aromatics present in soil HA. These research findings may shed additional light in understanding of the roles and underlying mechanisms of NOM reactions with contaminant metals, radionuclides, and other toxic chemicals in the natural environment. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Penn State Univ, Dept Civil & Environm Engn, University Pk, PA 16802 USA. RP Gu, BH (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Gu, Baohua/B-9511-2012 OI Gu, Baohua/0000-0002-7299-2956 NR 41 TC 98 Z9 116 U1 12 U2 68 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAY 20 PY 2003 VL 307 IS 1-3 BP 167 EP 178 AR PII S0048-9697(02)00538-7 DI 10.1016/S0048-9697(02)00538-7 PG 12 WC Environmental Sciences SC Environmental Sciences & Ecology GA 676DW UT WOS:000182737400012 PM 12711432 ER PT J AU Armitage, R Hong, W Yang, Q Feick, H Gebauer, J Weber, ER Hautakangas, S Saarinen, K AF Armitage, R Hong, W Yang, Q Feick, H Gebauer, J Weber, ER Hautakangas, S Saarinen, K TI Contributions from gallium vacancies and carbon-related defects to the "yellow luminescence" in GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID VAPOR-PHASE EPITAXY; TEMPERATURE; LAYERS; ORIGIN AB Carbon-doped GaN layers grown by molecular-beam epitaxy are studied with photoluminescence and positron annihilation spectroscopy. Semi-insulating layers doped with >10(18) cm(-3) carbon show a strong luminescence band centered at similar to2.2 eV (yellow luminescence). The absolute intensity of the 2.2 eV band is compared with the gallium vacancy concentration determined by positron annihilation spectroscopy. The results indicate that a high concentration of gallium vacancies is not necessary for yellow luminescence and that there is in fact a causal relationship between carbon and the 2.2 eV band. Markedly different deep-level ionization energies are found for the high-temperature quenching of the 2.2 eV photoluminescence in carbon-doped and reference samples. We propose that while the model of Neugebauer and Van de Walle [Appl. Phys. Lett. 69, 503 (1996)] applies for GaN of low carbon concentration, a different yellow luminescence mechanism is involved when the interstitial carbon concentration is comparable to or exceeds the gallium vacancy concentration. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Helsinki Univ Technol, Phys Lab, Helsinki 02015, Finland. RP Armitage, R (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. NR 19 TC 96 Z9 102 U1 4 U2 38 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 MAY 19 PY 2003 VL 82 IS 20 BP 3457 EP 3459 DI 10.1063/1.1578169 PG 3 WC Physics, Applied SC Physics GA 677TH UT WOS:000182823300027 ER PT J AU Liu, JY Wang, J Shan, B Wang, C Chang, ZH AF Liu, JY Wang, J Shan, B Wang, C Chang, ZH TI An accumulative x-ray streak camera with sub-600-fs temporal resolution and 50-fs timing jitter SO APPLIED PHYSICS LETTERS LA English DT Article ID DIFFRACTION; PHONONS AB We demonstrated that the shot-to-shot timing jitter of an x-ray streak camera was reduced to close to 50 fs when it was triggered by a standard kilohertz laser with 1.2% rms pulse energy fluctuation. This was achieved by improving the response time of deflection plates and the rise time of the ramp pulse generated by a photoconductive switch, and by operating the photoconductive switch at optimum conditions. Furthermore, after reducing the angular distribution of electron bunch, the temporal resolution of the x-ray streak camera operating in accumulation mode was measured to be better than 600 fs. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Expt Facil Div, Argonne, IL 60439 USA. Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. Kansas State Univ, JR Macdonald Lab, Manhattan, KS 66506 USA. RP Liu, JY (reprint author), Argonne Natl Lab, Expt Facil Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Chang, Zenghu/K-8143-2012 OI Chang, Zenghu/0000-0001-9015-0747 NR 12 TC 23 Z9 26 U1 1 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 MAY 19 PY 2003 VL 82 IS 20 BP 3553 EP 3555 DI 10.1063/1.1577213 PG 3 WC Physics, Applied SC Physics GA 677TH UT WOS:000182823300059 ER PT J AU Paul, M Valenta, A Ahmad, I Berkovits, D Bordeanu, C Ghelberg, S Hashimoto, Y Hershkowitz, A Jiang, S Nakanishi, T Sakamoto, K AF Paul, M Valenta, A Ahmad, I Berkovits, D Bordeanu, C Ghelberg, S Hashimoto, Y Hershkowitz, A Jiang, S Nakanishi, T Sakamoto, K TI A window on nucleosynthesis through detection of short-lived radionuclides SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 17th International Nuclear Physics Divisional Conference of the European-Physical-Society CY SEP 30-OCT 04, 2002 CL DEBRECEN, HUNGARY SP European Phys Soc ID IN-SITU MEASUREMENTS; INTERSTELLAR DUST; SUPERNOVA; ULYSSES; PLUTONIUM-244; HELIOSPHERE; ELEMENTS; GALILEO; GRAINS; SOLAR AB The detection of cosmic gamma radioactivity of live nuclides from supernovae remnants during the last decade has had an immense impact on our understanding of stellar nucleosynthesis. It is expected that, similarly, nuclides such as (146)sM, Pu-244, Hf-182, Cm-247 with halflives of the order of a few 10(7) years be present in the Interstellar Medium (ISM) as freshly synthesized matter; they are however not detectable by gamma-ray astronomy because of their lower activity. Depending on their steady-state abundance and the ISM influx rate in the solar system, deposition on Earth of these nuclides through cosmic dust and their detection may provide a complementary approach. A search for Pu-244 in a deep-sea sediment sample, acting here as repository archive for cosmic dust, was performed by accelerator mass spectrometry (AMS) and an upper limit for deposition of interstellar Pu-244 of 0.2 atoms/cm(2)/yr obtained. Derived constraints on Pu-244 abundance in the ISM are discussed. Further development of detection techniques for Pu-244 and other nuclides is under way. C1 Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Argonne Natl Lab, Dept Phys, Argonne, IL 60439 USA. Soreq NRC, IL-81800 Yavne, Israel. Weizmann Inst Sci, Particle Phys Dept, IL-76100 Rehovot, Israel. Kanazawa Univ, Fac Sci, Dept Chem, Kanazawa, Ishikawa 9201192, Japan. RP Paul, M (reprint author), Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RI Bordeanu, Cristina/J-3438-2012 OI Bordeanu, Cristina/0000-0003-4641-0630 NR 32 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 19 PY 2003 VL 719 BP 29C EP 36C DI 10.1016/S0375-9474(03)00954-0 PG 8 WC Physics, Nuclear SC Physics GA 672PR UT WOS:000182530000006 ER PT J AU Liebendorfer, M Mezzacappa, A Messer, OEB Martinez-Pinedo, G Hix, WR Thielemann, FK AF Liebendorfer, M Mezzacappa, A Messer, OEB Martinez-Pinedo, G Hix, WR Thielemann, FK TI The neutrino signal in stellar core collapse and postbounce evolution SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 17th International Nuclear Physics Divisional Conference of the European-Physical-Society CY SEP 30-OCT 04, 2002 CL DEBRECEN, HUNGARY SP European Phys Soc ID SUPERNOVA MECHANISM; TRANSPORT; EXPLOSIONS; CONVECTION; SIMULATION; MATTER; STARS C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Dept Phys, Oak Ridge, TN 37831 USA. Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. RP Liebendorfer, M (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. EM liebend@mail.phy.ornl.gov RI Messer, Bronson/G-1848-2012; Hix, William/E-7896-2011; Martinez-Pinedo, Gabriel/A-1915-2013; Mezzacappa, Anthony/B-3163-2017 OI Messer, Bronson/0000-0002-5358-5415; Hix, William/0000-0002-9481-9126; Martinez-Pinedo, Gabriel/0000-0002-3825-0131; Mezzacappa, Anthony/0000-0001-9816-9741 NR 37 TC 35 Z9 35 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 19 PY 2003 VL 719 BP 144C EP 152C DI 10.1016/S0375-9474(03)00984-9 PG 9 WC Physics, Nuclear SC Physics GA 672PR UT WOS:000182530000025 ER PT J AU Lexa, D Kropf, AJ AF Lexa, D Kropf, AJ TI The beam-heating effect in simultaneous differential scanning calorimetry/synchrotron powder X-ray diffraction SO THERMOCHIMICA ACTA LA English DT Article DE differential scanning calorimetry; synchrotron; beam energy; beam-heating AB An instrument for simultaneous differential scanning calorimetry/synchrotron powder X-ray diffraction was used to detect and quantify the beam-heating effect, i.e. the deposition of measurable energy into a sample by a synchrotron X-ray beam. For beam energy of 17 keV, incident beam flux of 4.27 x 10(11) photon/s, and beam size of 1000 mum x 300 mum, the measured power input into the sample is on the order of 1 mW. The ability to deliver the energy in the form of an almost ideal square-wave made it possible to accurately analyze the response of the differential scanning calorimeter to such an input. The beam-heating effect needs to be considered in performing and evaluating differential scanning calorimetry measurements involving synchrotron X-ray sources. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Austrian Res Ctr GmbH ARC, Aufarbeitung Radioaktiver Stoffe, A-2444 Seibersdorf, Austria. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Lexa, D (reprint author), Austrian Res Ctr GmbH ARC, Aufarbeitung Radioaktiver Stoffe, A-2444 Seibersdorf, Austria. RI ID, MRCAT/G-7586-2011 NR 7 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD MAY 19 PY 2003 VL 401 IS 2 BP 239 EP 242 AR PII S0040-6031(02)00504-X DI 10.1016/S0040-6031(02)00504-X PG 4 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 680YH UT WOS:000183007300018 ER PT J AU Jones, JB Stanley, EH Mulholland, PJ AF Jones, JB Stanley, EH Mulholland, PJ TI Long-term decline in carbon dioxide supersaturation in rivers across the contiguous United States SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOIL RESPIRATION; STREAM; PATTERNS; LAKES; QUALITY; STORAGE; TRENDS; WATER; FLUX; CO2 AB [1] The partial pressure CO2 ( pCO(2)) in streams and rivers reflects both internal carbon dynamics and external biogeochemical processes in terrestrial ecosystems. CO2 is typically supersaturated in streams because rates of organic matter decomposition exceed photosynthetic uptake, and because of inflow of CO2 supersaturated ground waters. Using the U. S. Geological Survey's NASQAN database, we calculated pCO(2) and dissolved inorganic carbon (DIC) concentration in 417 streams and rivers distributed across the contiguous United States over a 22-year period. In addition to demonstrating widespread supersaturation and distinct regional variation in pCO(2) across the U. S., our analysis revealed that pCO(2) significantly declined 78.4 ppmv y(-1) from 1973 to 1994. This decline is not attributable to changes in terrestrial weathering or instream processes, but instead suggests large-scale declines in terrestrial CO2 production and import into aquatic ecosystems during this 22-year period. C1 Univ Alaska, Inst Arctic Biol, Fairbanks, AK 99775 USA. Univ Wisconsin, Ctr Limnol, Madison, WI 53706 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Jones, JB (reprint author), Univ Alaska, Inst Arctic Biol, Fairbanks, AK 99775 USA. RI Mulholland, Patrick/C-3142-2012 NR 31 TC 38 Z9 40 U1 0 U2 12 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 MAY 17 PY 2003 VL 30 IS 10 AR 1495 DI 10.1029/2003GL017056 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 682QJ UT WOS:000183102800002 ER PT J AU Wong, WR Hawe, E Li, LK Miller, GJ Nicaud, V Pennacchio, LA Humphries, SE Talmud, PJ AF Wong, WR Hawe, E Li, LK Miller, GJ Nicaud, V Pennacchio, LA Humphries, SE Talmud, PJ TI Apolipoprotein AIV gene variant S347 is associated with increased risk of coronary heart disease and lower plasma apolipoprotein AIV levels SO CIRCULATION RESEARCH LA English DT Article DE apolipoprotein AIV; coronary heart disease risk; genetic polymorphism; haplotype analysis ID MIDDLE-AGED MEN; A-IV GENE; EUROPEAN ATHEROSCLEROSIS RESEARCH; DENSITY-LIPOPROTEIN CHOLESTEROL; ARTERY-DISEASE; TRIGLYCERIDE LEVELS; TRANSGENIC MICE; APOC-III; CLUSTER; POLYMORPHISMS AB The impact of common variants in the apolipoprotein gene cluster (APOC3-A4-A5) on prospective coronary heart disease (CHD) risk was examined in healthy UK men. Of the 2808 men followed over 9 years, 187 had a clinically defined CHD event. Examination of 9 single nucleotide polymorphisms (SNPs) in this group revealed that homozygotes for APOA4 S347 had significantly increased risk of CHD [hazard ratio (HR) of 2.07 (95%CI 1.04 to 4.12)], whereas men homozygous for APOC3 1100T were protected [HR 0.28 (95%CI 0.09 to 0.87)]. In stepwise multiple regression analysis, after entering all the variants and adjusting for established risk factors APOA4 T347S alone remained in the model. Using all nine SNPs, the highest risk-estimate haplotypes carried APOA4 S347 and rare alleles of the two flanking intergenic markers. The protective effect of APOC3 1100T could be explained by negative linkage disequilibrium with these alleles. To determine the association of APOA4 T347S with apoAIV levels, the relationship was examined in 1600 healthy young European men and women. S347 homozygotes had significantly lower apoAIV plasma levels (13.64+/-0.59 mg/dL) compared with carriers of the T347 allele (14.90+/-0.12 mg/dL) (P=0.035). These results demonstrate that genetic variation in and around APOA4, independent of the effects of triglyceride, is associated with risk of CHD and apoAIV levels, supporting an antiatherogenic role for apoAIV. C1 UCL Royal Free & Univ Coll Med Sch, Dept Med, British Heart Fdn Labs, Div Cardiovasc Genet, London WC1E 6JJ, England. Wolfson Inst Prevent Med, MRC, Cardiovasc Res Grp, London, England. Univ Paris 06, Paris, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Talmud, PJ (reprint author), UCL Royal Free & Univ Coll Med Sch, Dept Med, British Heart Fdn Labs, Div Cardiovasc Genet, 5 Univ St, London WC1E 6JJ, England. EM p.talmud@ucl.ac.uk RI Talmud, Philippa/C-4402-2008; Humphries, Stephen/C-5075-2008; OI Talmud, Philippa/0000-0002-5560-1933 FU PHS HHS [33014] NR 39 TC 48 Z9 53 U1 0 U2 10 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7330 J9 CIRC RES JI Circ.Res. PD MAY 16 PY 2003 VL 92 IS 9 BP 969 EP 975 DI 10.1161/01.RES.0000069688.94567.7A PG 7 WC Cardiac & Cardiovascular Systems; Hematology; Peripheral Vascular Disease SC Cardiovascular System & Cardiology; Hematology GA 678UZ UT WOS:000182886200008 PM 12676816 ER PT J AU Vu-Dac, N Gervois, P Jakel, H Nowak, M Bauge, E Dehondt, N Staels, B Pennacchio, LA Rubin, EM Fruchart-Najib, J Fruchart, JC AF Vu-Dac, N Gervois, P Jakel, H Nowak, M Bauge, E Dehondt, N Staels, B Pennacchio, LA Rubin, EM Fruchart-Najib, J Fruchart, JC TI Apolipoprotein A5, a crucial determinant of plasma triglyceride levels, is highly responsive to peroxisome proliferator-activated receptor alpha activators SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID FAMILIAL COMBINED HYPERLIPIDEMIA; CORONARY HEART-DISEASE; C-III EXPRESSION; GENE-CLUSTER; PPAR-ALPHA; HYPERTRIGLYCERIDEMIA; MICE; OVEREXPRESSION; POLYMORPHISMS; SUPERFAMILY AB The recently discovered APOA5 gene has been shown in humans and mice to be important in determining plasma triglyceride levels, a major cardiovascular disease risk factor. apoAV represents the first described apolipoprotein where overexpression lowers triglyceride levels. Since fibrates represent a commonly used therapy for lowering plasma triglycerides in humans, we investigated their ability to modulate APOA5 gene expression and consequently influence plasma triglyceride levels. Human primary hepatocytes treated with Wy 14,643 or fenofibrate displayed a strong induction of APOA5 mRNA. Deletion and mutagenesis analyses of the proximal APOA5 promoter firmly demonstrate the presence of a functional peroxisome proliferator-activated receptor response element. These findings demonstrate that APOA5 is a highly responsive peroxisome proliferator-activated receptor alpha target gene and support its role as a major mediator for how fibrates reduce plasma triglycerides in humans. C1 Inst Pasteur, INSERM, U545, Dept Atherosclerose, F-59019 Lille, France. Fac Pharm Lille 1, F-59019 Lille, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Joint Genome Inst, Berkeley, CA 94720 USA. RP Vu-Dac, N (reprint author), Inst Pasteur, INSERM, U545, Dept Atherosclerose, BP 245, F-59019 Lille, France. NR 31 TC 150 Z9 165 U1 1 U2 3 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 MAY 16 PY 2003 VL 278 IS 20 BP 17982 EP 17985 DI 10.1074/jbc.M212191200 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 677YX UT WOS:000182838300050 PM 12637506 ER PT J AU Gokulan, K Rupp, B Pavelka, MS Jacobs, WR Sacchettini, JC AF Gokulan, K Rupp, B Pavelka, MS Jacobs, WR Sacchettini, JC TI Crystal structure of Mycobacterium tuberculosis diaminopimelate decarboxylase, an essential enzyme in bacterial lysine biosynthesis SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID EUKARYOTIC ORNITHINE DECARBOXYLASE; TRANSFER-RNA-SYNTHETASE; LYSA GENE; DENSITY-MODIFICATION; ANGSTROM RESOLUTION; UPSTREAM REGION; SEQUENCE; BINDING; PROGRAM; REFINEMENT AB The Mycobacterium tuberculosis lysA gene encodes the enzyme meso-diaminopimelate decarboxylase (DAPDC), a pyridoxal-5'-phosphate (PLP)-dependent enzyme. The enzyme catalyzes the final step in the lysine biosynthetic pathway converting meso-diaminopimelic acid (DAP) to L-lysine. The lysA gene of M. tuberculosis H37Rv has been established as essential for bacterial survival in immunocompromised mice, demonstrating that de novo biosynthesis of lysine is essential for in vivo viability. Drugs targeted against DAPDC could be efficient anti-tuberculosis drugs, and the three-dimensional structure of DAPDC from M. tuberculosis complexed with reaction product lysine and the ternary complex with PLP and lysine in the active site has been determined. The first structure of a DAPDC confirms its classification as a fold type III PLP-dependent enzyme. The structure shows a stable 2-fold dimer in head-to-tail arrangement of a triose-phosphate isomerase (TIM) barrel-like alpha/beta domain and a C-terminal beta sheet domain, similar to the ornithine decarboxylase (ODC) fold family. PLP is covalently bound via an internal aldimine, and residues from both domains and both subunits contribute to the binding pocket. Comparison of the structure with eukaryotic ODCs, in particular with a difluoromethyl ornithine (DMFO)-bound ODC from Trypanosoma bruceii, indicates that corresponding DAP-analogues might be potential inhibitors for mycobacterial DAPDCs. C1 Texas A&M Univ, Dept Biochem & Biophys, College Stn, TX 77843 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Albert Einstein Coll Med, Dept Microbiol & Immunol, Bronx, NY 10461 USA. Albert Einstein Coll Med, Howard Hughes Med Inst, Bronx, NY 10461 USA. RP Sacchettini, JC (reprint author), Texas A&M Univ, Dept Biochem & Biophys, College Stn, TX 77843 USA. FU NIGMS NIH HHS [P50 GM62410] NR 45 TC 44 Z9 50 U1 0 U2 12 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 MAY 16 PY 2003 VL 278 IS 20 BP 18588 EP 18596 DI 10.1074/jbc.M301549200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 677YX UT WOS:000182838300131 PM 12637582 ER PT J AU Fritz, JS Yan, Z Haddad, PR AF Fritz, JS Yan, Z Haddad, PR TI Modification of ion chromatographic separations by ionic and nonionic surfactants SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 15th International Ion Chromatography Symposium CY SEP 29-OCT 02, 2002 CL BALTIMORE, MARYLAND DE coated columns; dynamic coating; surfactants; inorganic anions; inorganic cations; organic acids ID DIPOLAR ELUENT COMPONENT; ANION-EXCHANGE; CONDUCTIVITY DETECTION; CATION CHROMATOGRAPHY; LIQUID-CHROMATOGRAPHY; PHOTOMETRIC DETECTION; STATIONARY PHASES; INORGANIC ANIONS; COATED COLUMNS; ORGANIC-ACIDS AB New findings are reported on simple ways to modify an ordinary HPLC column to obtain efficient ion chromatographic (IC) separations. Permanently coating a column with an ionic surfactant is known to produce an effective column for IC. We now show that incorporation of a nonionic surfactant in the coating, or coating in separate layers, results in a dramatic reduction of ion retention times and gives sharper peaks. Dynamic coating by incorporating a small amount of an alcohol, diol or zwitterion in the aqueous mobile phase permits good separations of alkanecarboxylic acids. A mobile phase containing a quaternary ammonium cation and a zwitterion anion provides excellent separations of common anions on a silica C, column. An aqueous eluent containing a mixture of a zwitterion 4-(2-hydroxyethyl) acid and methanesulfonic acid can be used in conjunction with a standard cation exchange column. After passing through a membrane suppressor, the mobile phase has a slightly acidic pH, permitting divalent transition metal ions (as well as others) to be detected by conductivity. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, US Dept Energy, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Tasmania, Sch Chem, Australian Ctr Res Separat Sci, Hobart, Tas 7001, Australia. Zhejiang Univ, Dept Chem, Hangzhou 310028, Peoples R China. RP Fritz, JS (reprint author), Iowa State Univ, US Dept Energy, Ames Lab, 332 Wilhelm Hall, Ames, IA 50011 USA. NR 30 TC 23 Z9 24 U1 2 U2 9 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 MAY 16 PY 2003 VL 997 IS 1-2 BP 21 EP 31 DI 10.1016/S0021-9673(03)00114-6 PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 687HV UT WOS:000183371400004 PM 12830873 ER PT J AU Fritz, JS Arena, MP Steiner, SA Porter, MD AF Fritz, JS Arena, MP Steiner, SA Porter, MD TI Rapid determination of ions by combined solid-phase extraction-diffuse reflectance spectroscopy SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 15th International Ion Chromatography Symposium CY SEP 29-OCT 02, 2002 CL BALTIMORE, MARYLAND DE colorimetric solid-phase extraction; extraction methods; diffuse reflectance spectroscopy; detection, solid-phase extraction; metal cations ID PRECONCENTRATION; WATER AB We introduce colorimetric solid-phase extraction (C-SPE) for the rapid determination of selected ions. This new technique links the exhaustive concentration of an analyte by SPE onto a membrane disk surface for quantitative measurement with a hand-held diffuse reflectance spectrometer. The concentration/measurement procedure is complete in similar to1 min and can be performed almost anywhere. This method has been used to monitor iodine and iodide in spacecraft water in the 0.1-5.0 ppm range and silver(l) in the range of 5.0-1000 mug/l. Applications to the trace analysis of copper(II), nickel(II), iron(III) and chromium(VI) are described. Studies on the mechanism of extraction showed that impregnation of the disk with a surfactant as well as a complexing reagent results in uptake of additional water, which markedly improves the extraction efficiency. (C) 2003 Published by Elsevier Science B.V. C1 Iowa State Univ, US Dept Energy, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Fritz, JS (reprint author), Iowa State Univ, US Dept Energy, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. NR 17 TC 27 Z9 27 U1 0 U2 3 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 MAY 16 PY 2003 VL 997 IS 1-2 BP 41 EP 50 DI 10.1016/S0021-9673(03)00551-X PG 10 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 687HV UT WOS:000183371400006 PM 12830875 ER PT J AU Tanaka, K Mori, M Xu, Q Helaleh, MIH Ikedo, M Taoda, H Hu, WZ Hasebe, K Fritz, JS Haddad, PR AF Tanaka, K Mori, M Xu, Q Helaleh, MIH Ikedo, M Taoda, H Hu, WZ Hasebe, K Fritz, JS Haddad, PR TI Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 15th International Ion Chromatography Symposium CY SEP 29-OCT 02, 2002 CL BALTIMORE, MARYLAND DE mobile phase composition; carboxylic acids; benzoic acid; cyclodextrins ID SEPARATION AB In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pK(a) values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in I mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a I mM benzoic acid-10 mM cyclodextrin solution without chemical suppression. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Natl Inst Adv Ind Sci & Technol, Seto, Aichi 4890884, Japan. Chubu Univ, Grad Sch Engn, Aichi 4878501, Japan. Hokkaido Univ, Sapporo, Hokkaido 0600810, Japan. Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Tasmania, Hobart, Tas 7001, Australia. RP Tanaka, K (reprint author), Natl Inst Adv Ind Sci & Technol, 110 Nishiibara Cho, Seto, Aichi 4890884, Japan. NR 16 TC 15 Z9 17 U1 0 U2 2 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 MAY 16 PY 2003 VL 997 IS 1-2 BP 127 EP 132 DI 10.1016/S0021-9673(03)00545-4 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 687HV UT WOS:000183371400015 PM 12830884 ER PT J AU Hodge, EM AF Hodge, EM TI Trace perchlorates in a radiological liquid-waste treatment facility SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 15th International Ion Chromatography Symposium CY SEP 29-OCT 02, 2002 CL BALTIMORE, MARYLAND DE perchlorates AB Waste management programs at the Radioactive Liquid Waste Treatment Facility (RLWTF) at the Los Alamos National Laboratory (LANL) are concerned with the levels of perchlorates due to the effects it can have on the environment and resultant regulations. The RLWTF treats industrial and radioactive wastes generated at multiple research and production facilities across the LANL. Perchloric acid is the major source of the perchlorate ion in the RLWTF used in the analytical chemistry laboratories and for metal dissolution. Perchlorate is present in the influent to the RLWTF at concentrations up to several thousands mug/l level. Ion chromatography is the method of choice to analyze the concentrations of perchlorate in the wastewater generated at the RLWTF. Perchlorate was separated by elution through a CS16/CG16 with an EG40 eluent generator. To minimize background conductivity and enhance analyte conductance, an anion self-regenerating suppressor was used. The method achieved a perchlorate method detection limit of 1 mug/l. The method is successfully being used to monitor the perchlorate levels at the RLWTF and provide data for the pilot tests to remove perchlorate from the RLWTF effluent. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hodge, EM (reprint author), Los Alamos Natl Lab, E518, Los Alamos, NM 87545 USA. NR 4 TC 2 Z9 3 U1 1 U2 2 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 MAY 16 PY 2003 VL 997 IS 1-2 BP 243 EP 247 DI 10.1016/S0021-9673(03)00629-0 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 687HV UT WOS:000183371400029 PM 12830898 ER PT J AU Gary, SP Saito, S AF Gary, SP Saito, S TI Particle-in-cell simulations of Alfven-cyclotron wave scattering: Proton velocity distributions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE solar corona; plasma; proton heating; simulation ID FAST SOLAR-WIND; OUTWARD PROPAGATING WAVES; KINETIC SHELL-MODEL; CORONAL HOLES; ANISOTROPY CONSTRAINT; COULOMB COLLISIONS; ION DISTRIBUTIONS; ACCELERATION; RESONANCE; TURBULENCE AB [1] Alfven-cyclotron fluctuations propagating parallel or antiparallel to the background magnetic field B-o help shape solar wind ion velocity distributions f(i)(v). Alfven waves may be generated at low, nonresonant frequencies and, by propagation through the inhomogeneous plasma, attain ion cyclotron resonances and thereby scatter the f(i)(v) to anisotropy. Ion anisotropies of sufficient magnitude lead to the growth of ion cyclotron instabilities; the resulting enhanced Alfven-cyclotron fluctuations scatter ions so as to reduce the anisotropy. Here particle-in-cell simulations were carried out in a magnetized, homogeneous, collisionless plasma of electrons and one ion species to study the evolution of the fi( v) in response to both of these scattering processes. A simulation with a spectrum of right-traveling Alfven-cyclotron fluctuations imposed at t = 0 leads to non-Maxwellian ion distributions. The computations show that the pitch angle scattering of left-traveling (nu(parallel to) < 0) ions becomes weaker as nu parallel to becomes less negative but also that this scattering can transport ions across the condition nu parallel to = 0, where the subscript denotes the direction parallel to B-o. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Toyama Univ, Lab Plasma Astrophys, Toyama 9308555, Japan. RP Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. EM pgary@lanl.gov; d023008@ems.toyama-u.ac.jp NR 46 TC 29 Z9 30 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 16 PY 2003 VL 108 IS A5 AR 1194 DI 10.1029/2002JA009824 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 682TN UT WOS:000183108600005 ER PT J AU Black, TC Huffman, PR Jacobson, DL Snow, WM Schoen, K Arif, M Kaiser, H Lamoreaux, SK Werner, SA AF Black, TC Huffman, PR Jacobson, DL Snow, WM Schoen, K Arif, M Kaiser, H Lamoreaux, SK Werner, SA TI Precision neutron interferometric measurement of the nd coherent neutron scattering length and consequences for models of three-nucleon forces SO PHYSICAL REVIEW LETTERS LA English DT Article ID FADDEEV CONTINUUM CALCULATIONS; 3-NUCLEON FORCE; DEUTERON SCATTERING; ANALYZING POWER; SYSTEMS AB We have performed the first high precision measurement of the coherent neutron scattering length of deuterium in a pure sample using neutron interferometry. We find b(nd) = (6.665 +/- 0.004) fm in agreement with the world average of previous measurements using different techniques, b(nd) = (6.6730 +/- 0.0045) fm. We compare the new world average for the nd coherent scattering length b(nd) = (6.669 +/- 0.003) fm to calculations of the doublet and quartet scattering lengths from several modern nucleon-nucleon potential models with three-nucleon force (3NF) additions and show that almost all theories are in serious disagreement with experiment. This comparison is a more stringent test of the models than past comparisons with the less precisely determined doublet scattering length of 2(and) = (0.65 +/- 0.04) fm. C1 Univ N Carolina, Wilmington, NC 28403 USA. NIST, Gaithersburg, MD 20899 USA. Indiana Univ, IUCF, Bloomington, IN 47408 USA. Univ Missouri, Columbia, MO 65211 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Black, TC (reprint author), Univ N Carolina, Wilmington, NC 28403 USA. NR 32 TC 18 Z9 18 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 MAY 16 PY 2003 VL 90 IS 19 AR 192502 DI 10.1103/PhysRevLett.90.192502 PG 4 WC Physics, Multidisciplinary SC Physics GA 679NG UT WOS:000182928300008 PM 12785940 ER PT J AU Jaeger, EF Berry, LA Myra, JR Batchelor, DB D'Azevedo, E Bonoli, PT Phillips, CK Smithe, DN D'Ippolito, DA Carter, MD Dumont, RJ Wright, JC Harvey, RW AF Jaeger, EF Berry, LA Myra, JR Batchelor, DB D'Azevedo, E Bonoli, PT Phillips, CK Smithe, DN D'Ippolito, DA Carter, MD Dumont, RJ Wright, JC Harvey, RW TI Sheared poloidal flow driven by mode conversion in tokamak plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID ION-BERNSTEIN WAVES; TOROIDAL PLASMAS; CYCLOTRON; TFTR; PROPAGATION; FREQUENCY; FORCE AB A two-dimensional integral full-wave model is used to calculate poloidal forces driven by mode conversion in tokamak plasmas. In the presence of a poloidal magnetic field, mode conversion near the ion-ion hybrid resonance is dominated by a transition from the fast magnetosonic wave to the slow ion cyclotron wave. The poloidal field generates strong variations in the parallel wave spectrum that cause wave damping in a narrow layer near the mode conversion surface. The resulting poloidal forces in this layer drive sheared poloidal flows comparable to those in direct launch ion Bernstein wave experiments. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Lodestar Res Corp, Boulder, CO 80301 USA. MIT, Ctr Plasma Fus, Cambridge, MA 02139 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Mission Res Corp, Newington, VA 22122 USA. CompX, Del Mar, CA 92014 USA. RP Jaeger, EF (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dumont, Remi/D-3840-2009 NR 24 TC 60 Z9 60 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 16 PY 2003 VL 90 IS 19 AR 195001 DI 10.1103/PhysRevLett.90.195001 PG 4 WC Physics, Multidisciplinary SC Physics GA 679NG UT WOS:000182928300019 PM 12785951 ER PT J AU Kelton, KF Lee, GW Gangopadhyay, AK Hyers, RW Rathz, TJ Rogers, JR Robinson, MB Robinson, DS AF Kelton, KF Lee, GW Gangopadhyay, AK Hyers, RW Rathz, TJ Rogers, JR Robinson, MB Robinson, DS TI First x-ray scattering studies on electrostatically levitated metallic liquids: Demonstrated influence of local icosahedral order on the nucleation barrier SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTAL-FORMING ALLOYS; SHORT-RANGE ORDER; ORIENTATIONAL ORDER; MELTS; SOLIDIFICATION; SYMMETRY; GLASSES AB To explain the unusual stability of undercooled liquids against crystallization, Frank hypothesized that the local structures of undercooled liquids contain a significant degree of icosahedral short-range order, which is incompatible with long-range periodicity. We present here the first direct experimental demonstration of Frank's complete hypothesis, showing a correlation between the nucleation barrier and a growing icosahedral short-range order with decreasing temperature in a Ti39.5Zr39.5Ni21 liquid. A new experimental facility, BESL (Beamline Electrostatic Levitation), was developed to enable the synchrotron x-ray structural studies on deeply undercooled, reactive liquids. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Massachusetts, Amherst, MA 01003 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Kelton, KF (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. RI Hyers, Robert/G-3755-2010 NR 22 TC 336 Z9 343 U1 9 U2 69 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 MAY 16 PY 2003 VL 90 IS 19 AR 195504 DI 10.1103/PhysRevLett.90.195504 PG 4 WC Physics, Multidisciplinary SC Physics GA 679NG UT WOS:000182928300024 PM 12785956 ER PT J AU Moore, KT Wall, MA Schwartz, AJ Chung, BW Shuh, DK Schulze, RK Tobin, JG AF Moore, KT Wall, MA Schwartz, AJ Chung, BW Shuh, DK Schulze, RK Tobin, JG TI Failure of Russell-Saunders coupling in the 5f states of plutonium SO PHYSICAL REVIEW LETTERS LA English DT Article ID DELTA-PU; RESONANT PHOTOEMISSION; ACTINIDE METALS; LOCALIZATION; ELECTRONS; THRESHOLD; SERIES AB Using high energy-electron energy loss spectroscopy, transmission electron microscopy, and synchrotron-radiation-based x-ray absorption spectroscopy, we provide the first experimental evidence that Russell-Saunders (LS) coupling fails for the 5f states of Pu. These results support the assumption that only the use of jj or intermediate coupling is appropriate for the 5f states of Pu. High energy-electron energy loss spectroscopy experiments were performed by use of a transmission electron microscope and are coupled with image and diffraction data; therefore, the measurements are completely phase specific. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Moore, KT (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Chung, Brandon/G-2929-2012; Tobin, James/O-6953-2015 NR 32 TC 60 Z9 61 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 16 PY 2003 VL 90 IS 19 AR 196404 DI 10.1103/PhysRevLett.90.196404 PG 4 WC Physics, Multidisciplinary SC Physics GA 679NG UT WOS:000182928300032 PM 12785964 ER PT J AU Anderson, TL Charlson, RJ Schwartz, SE Knutti, R Boucher, O Rodhe, H Heintzenberg, J AF Anderson, TL Charlson, RJ Schwartz, SE Knutti, R Boucher, O Rodhe, H Heintzenberg, J TI Climate forcing by aerosols - a hazy picture SO SCIENCE LA English DT Editorial Material ID SENSITIVITY C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Univ Sci & Technol Lille, CNRS, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. Stockholm Univ, Dept Meteorol, SE-10691 Stockholm, Sweden. Inst Tropospher Res, D-04318 Leipzig, Germany. RP Anderson, TL (reprint author), Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RI Boucher, Olivier/J-5810-2012; Boucher, Olivier/K-7483-2012; Schwartz, Stephen/C-2729-2008; Knutti, Reto/B-8763-2008 OI Boucher, Olivier/0000-0003-2328-5769; Boucher, Olivier/0000-0003-2328-5769; Schwartz, Stephen/0000-0001-6288-310X; Knutti, Reto/0000-0001-8303-6700 NR 19 TC 197 Z9 218 U1 3 U2 39 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 MAY 16 PY 2003 VL 300 IS 5622 BP 1103 EP 1104 DI 10.1126/science.1084777 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 678VC UT WOS:000182886500030 PM 12750507 ER PT J AU Rosi, NL Eckert, J Eddaoudi, M Vodak, DT Kim, J O'Keeffe, M Yaghi, OM AF Rosi, NL Eckert, J Eddaoudi, M Vodak, DT Kim, J O'Keeffe, M Yaghi, OM TI Hydrogen storage in microporous metal-organic frameworks SO SCIENCE LA English DT Article ID INELASTIC NEUTRON-SCATTERING; ZEOLITE NA-A; MOLECULAR-HYDROGEN; CARBON NANOTUBES; DESIGN; ADSORPTION; ROTATION AB Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)(3) (BDC = 1,4-benzenedicarboxylate) with a cubic three-dimensional extended porous structure adsorbed hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. Inelastic neutron scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules indicates the presence of two well-defined binding sites (termed I and II), which we associate with hydrogen binding to zinc and the BDC linker, respectively. Preliminary studies on topologically similar isoreticular metal-organic framework-6 and -8 (IRMOF-6 and -8) having cyclobutylbenzene and naphthalene linkers, respectively, gave approximately double and quadruple (2.0 weight percent) the uptake found for MOF-5 at room temperature and 10 bar. C1 Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. Univ S Florida, Dept Chem, Tampa, FL 33620 USA. Arizona State Univ, Dept Chem, Tempe, AZ 85287 USA. RP Yaghi, OM (reprint author), Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. RI Eddaoudi, Mohamed/D-2298-2009; OI Eddaoudi, Mohamed/0000-0003-1916-9837; Yaghi, Omar/0000-0002-5611-3325 NR 21 TC 2918 Z9 2966 U1 207 U2 1729 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 MAY 16 PY 2003 VL 300 IS 5622 BP 1127 EP 1129 DI 10.1126/science.1083440 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 678VC UT WOS:000182886500039 PM 12750515 ER PT J AU Dutta, P Tipple, CA Lavrik, NV Datskos, PG Hofstetter, H Hofstetter, O Sepaniak, MJ AF Dutta, P Tipple, CA Lavrik, NV Datskos, PG Hofstetter, H Hofstetter, O Sepaniak, MJ TI Enantioselective sensors based on antibody-mediated nanomechanics SO ANALYTICAL CHEMISTRY LA English DT Article ID IMMUNOAFFINITY CHROMATOGRAPHY; SURFACE STRESS; FILMS; MICROCANTILEVERS; DISCRIMINATION; ENANTIOMERS; PERFORMANCE; CANTILEVERS; PHASES AB The use of microfabricated cantilevers as bioaffinity sensors was investigated. Since many bioaffinity interactions involve proteins as receptors, we conducted studies of the magnitude, kinetics, and reversibility of surface stresses caused when common proteins interact with microcantilevers (MCs) with nanostructured (roughened) gold surfaces on one side. Exposure of nanostructured, unfunctionalized MCs to the proteins immunoglobulin G and bovine serum albumin (BSA) resulted in reversible large tensile stresses, whereas MCs with smooth gold surfaces on one side produced reversible responses that were considerably smaller and compressive. The response magnitude for nanostructured MCs exposed to BSA is shown to be concentration dependent, and linear calibration over the range of 1-200 mg/L is demonstrated. Stable, reusable protein bioaffinity phases based on unique enantioselective antibodies are created by co-valently linking monoclonal antibodies to nanostructured MC surfaces. The direct (label-free) stereoselective detection of trace amounts of an important class of chiral analytes, the a-amino acids, was achieved based on immunomechanical responses involving nanoscale bending of the cantilever. The temporal response of the cantilever (Delta deflection/Delta time) is linearly proportional to the analyte concentration and allows the quantitative determination of enantiomeric purity up to an enantiomeric excess of 99.8%. To our knowledge, this is the first demonstration of chiral discrimination using highly scalable microelectromechanical systems. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. No Illinois Univ, Dept Chem & Biochem, De Kalb, IL 60115 USA. RP Sepaniak, MJ (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM sepaniak@novell.chem.utk.edu RI Lavrik, Nickolay/B-5268-2011 OI Lavrik, Nickolay/0000-0002-9543-5634 NR 34 TC 76 Z9 80 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 15 PY 2003 VL 75 IS 10 BP 2342 EP 2348 DI 10.1021/ac034031z PG 7 WC Chemistry, Analytical SC Chemistry GA 679WH UT WOS:000182944600020 PM 12918975 ER PT J AU Roca, L Izquierdo, M Tejeda, A Gu, GD Avila, J Asensio, MC AF Roca, L Izquierdo, M Tejeda, A Gu, GD Avila, J Asensio, MC TI Matrix element effects on the Fermi surface mapping by angle resolved photoemission from Bi2Sr2CaCU2O8+x superconductors SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 11th International Conference on Solid Films and Surfaces (ICSFE-11) CY JUL 08-12, 2002 CL MARSEILLE, FRANCE DE angle resolved photoemission; matrix element; fermi surface; superconductivity; Bisco ID T-C SUPERCONDUCTORS; NORMAL-STATE; GAP; DISPERSION AB We report angle resolved photoemission spectra (ARPES) from the Fermi energy (E-F) over a large area of the reciprocal space using polarized and unpolarized synchrotron radiation light, in two particular distinctive geometries of detection from a mono-domain single crystal of Bi2Sr2CaCu2O8+x (Bi-2212) optimally doped. The data display a wide-ranging level of accord with previously reported ARPES results and clarify how many apparently dissimilar Fermi surface (FS) maps emerge in ARPES, under different experimental conditions. The energy and polarization dependences of the ARPES matrix elements help disentangle primary contributions from the main FS bands to the spectrum from those arising from secondary effects. The remarkable influence of the matrix elements on the ARPES intensity allows us to unravel the principal FS bands, from those robust features associated to the incommensurate superstructure modulations, as well as provide us a reliable route for separating closely placed FS sheets in low dimensional materials. (C) 2003 Elsevier Science B.V. All rights reserved. C1 CSIC, Inst Ciencia Mat, E-28049 Madrid, Spain. Univ Paris 11, LURE, F-91898 Orsay, France. Brookhaven Natl Lab, Dept Phys, Brookhaven, NY 11975 USA. RP Asensio, MC (reprint author), CSIC, Inst Ciencia Mat, E-28049 Madrid, Spain. RI Tejeda, Antonio/C-4711-2014 OI Tejeda, Antonio/0000-0003-0125-4603 NR 20 TC 4 Z9 4 U1 1 U2 2 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 MAY 15 PY 2003 VL 212 BP 62 EP 66 DI 10.1016/S0169-4332(03)00027-8 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 697WX UT WOS:000183967200012 ER PT J AU Izquierdo, M Roca, L Gu, DG Avila, J Asensio, MC AF Izquierdo, M Roca, L Gu, DG Avila, J Asensio, MC TI Shadow bands at the Fermi surface of Bi2Sr2CaCu2O8+x superconductors: structural or antiferromagnetic origin? SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 11th International Conference on Solid Films and Surfaces (ICSFE-11) CY JUL 08-12, 2002 CL MARSEILLE, FRANCE DE superconductivity; angle resolved photoemission; Fermi surface; Bisco ID INCOMMENSURATE MODULATION; MAGNETIC FLUCTUATIONS; ELECTRONIC-STRUCTURE; STRIPE-PHASE; COEXISTENCE; CHARGE; PHOTOEMISSION; YBA2CU3O6.6; METALLICITY; BI2SR2CUO6 AB In this paper, we report measurements on the Fermi surface (FS) topology of Bi2Sr2CaCu2O8+x (Bi-2212) superconductors by angle scanning photoemission spectroscopy using polarized synchrotron radiation. Our k-scanning approach allows us to record the full symmetry of the main features of the FS throughout large portions of the reciprocal space, as well as their dependence on the polarization and energy of the incident light. In the recorded two-dimensional images, we have clearly identified in addition to the principal FS and its "umklapps" replicas another bands of much smaller intensity, previously reported as "shadow FS". The k-dependence of these bands is identical that to the principal FS, but displaced by a wave-vector (pi,pi). In the present study, we provide a qualitative analysis of this superstructure as well as its relationship with the structural order and the low-energy magnetic fluctuations of these compounds. (C) 2003 Elsevier Science B.V. All rights reserved. C1 CSIC, Inst Ciencia Mat, Madrid 28049, Spain. Ctr Univ Paris Sud, LURE, F-91898 Orsay, France. Brookhaven Natl Lab, Dept Phys, Long Isl City, NY 11975 USA. RP Asensio, MC (reprint author), CSIC, Inst Ciencia Mat, Madrid 28049, Spain. NR 28 TC 3 Z9 3 U1 0 U2 0 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 MAY 15 PY 2003 VL 212 BP 67 EP 72 DI 10.1016/S0169-4332(03)00028-X PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 697WX UT WOS:000183967200013 ER PT J AU Ashurst, WR de Boer, MP Carraro, C Maboudian, R AF Ashurst, WR de Boer, MP Carraro, C Maboudian, R TI An investigation of sidewall adhesion in MEMS SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 11th International Conference on Solid Films and Surfaces (ICSFE-11) CY JUL 08-12, 2002 CL MARSEILLE, FRANCE DE adhesion; MEMS; sidewall; stiction ID MONOLAYER FILMS; SYSTEMS AB Adhesion or stiction is a key problem in surface micromachining technology, affecting the reliability of most MEMS. To date, the quantitative analysis of the phenomenon has been limited to in-plane adhesion. Since many micromechanisms involve contacts between sidewalls, we have designed a microinstrument to measure sidewall adhesion. Here, we describe the design, modeling, results and problems encountered with this first generation of sidewall adhesion devices. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ashurst, WR (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI de Boer, Maarten/C-1525-2013 OI de Boer, Maarten/0000-0003-1574-9324 NR 13 TC 30 Z9 31 U1 2 U2 6 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 MAY 15 PY 2003 VL 212 BP 735 EP 741 DI 10.1016/S0169-4332(03)00093-X PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 697WX UT WOS:000183967200132 ER PT J AU Parra, MK Gee, SL Koury, MJ Mohandas, N Conboy, JG AF Parra, MK Gee, SL Koury, MJ Mohandas, N Conboy, JG TI Alternative 5 ' exons and differential splicing regulate expression of protein 4.1R isoforms with distinct N-termini SO BLOOD LA English DT Article ID PRE-MESSENGER-RNA; DELTA-AMINOLEVULINATE DEHYDRATASE; ERYTHROID-DIFFERENTIATION; FUNCTIONAL ASSOCIATION; STRUCTURAL PROTEIN-4.1; NONERYTHROID ISOFORM; MEMBRANE STABILITY; MULTIPLE ISOFORMS; POLYMERASE-II; GENE AB Among the alternative pre-mRNA splicing events that characterize protein 4.1 R gene expression, one involving exon 2' plays a critical role in regulating translation initiation and N-terminal protein structure. Exon 2' encompasses translation initiation site AUG1 and is located between alternative splice acceptor sites at the 5' end of exon 2; its inclusion or exclusion from mature 4.1 R mRNA regulates expression of longer or shorter isoforms of 4.1 R protein, respectively. The current study reports unexpected complexity in the 5' region of the 4.1 R gene that directly affects alternative splicing of exon 2'. Identified far upstream of exon 2 in both mouse and human genomes were 3 mutually exclusive alternative 5' exons, designated 1 A, 1 B, and 1 C; all 3 are associated with strong transcriptional promoters in the flanking genomic sequence. Importantly, exons 1A and 1B splice differentially with respect to exon 2', generating transcripts with different 5' ends and distinct N-terminal protein coding capacity. Exon 1A-type transcripts splice so as to exclude exon 2' and therefore utilize the downstream AUG2 for translation of 80-kDa 4.1 R protein, whereas exon 1B transcripts include exon 2' and initiate at AUG1 to synthesize 135-kDa isoforms. RNA blot analyses revealed that 1A transcripts increase in abundance in late erythroblasts, consistent with the previously demonstrated up-regulation of 80-kDa 4.1 R during terminal erythroid differentiation. Together, these results suggest that synthesis of structurally distinct 4.1 R protein isoforms in various cell types is regulated by a novel mechanism requiring coordination between upstream transcription initiation events and downstream alternative splicing events. C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Vanderbilt Univ, Dept Med, Vet Affairs Med Ctr, Nashville, TN USA. New York Blood Ctr, New York, NY 10021 USA. RP Conboy, JG (reprint author), Lawrence Berkeley Natl Lab, Div Life Sci, Mailstop 74-157,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [R01 HL045182, HL45182]; NIDDK NIH HHS [P01 DK032094, DK32094] NR 58 TC 27 Z9 27 U1 0 U2 1 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1900 M STREET. NW SUITE 200, WASHINGTON, DC 20036 USA SN 0006-4971 J9 BLOOD JI Blood PD MAY 15 PY 2003 VL 101 IS 10 BP 4164 EP 4171 DI 10.1182/blood-200-06-1796 PG 8 WC Hematology SC Hematology GA 677EB UT WOS:000182793000065 PM 12522012 ER PT J AU Bruce, LJ Beckmann, R Ribeiro, ML Peters, LL Chasis, JA Delaunay, J Mohandas, N Anstee, DJ Tanner, MJA AF Bruce, LJ Beckmann, R Ribeiro, ML Peters, LL Chasis, JA Delaunay, J Mohandas, N Anstee, DJ Tanner, MJA TI A band 3-based macrocomplex of integral and peripheral proteins in the RBC membrane SO BLOOD LA English DT Article ID HUMAN ERYTHROCYTE-MEMBRANE; BLOOD-GROUP GLYCOPROTEIN; GROUP ANTIGEN EXPRESSION; RENAL TUBULAR-ACIDOSIS; OVARIAN TUMOR-MARKER; MONOCLONAL-ANTIBODIES; HEREDITARY SPHEROCYTOSIS; ANION-EXCHANGER; GLYCOPHORIN-A; CELL MEMBRANE AB We have studied the membrane proteins of band 3 anion exchanger (AE1)-deficient mouse and human red blood cells. It has been shown previously that proteins of the band 3 complex are reduced or absent in these cells. In this study we show that proteins of the Rh complex are also greatly reduced (Rh-associated glycoprotein, Rh polypeptides, CD47, glycophorin B) or absent (LW). These observations suggest that the Rh complex is associated with the band 3 complex in healthy RBCs. Mouse band 3(-/-) RBCs differed from the human band 3-deficient RBCs in that they retained CD47. Aquaporin 1 was reduced, and its glycosylation was altered in mouse and human band 3-deficient RBCs. Proteins of the glycophorin C complex, and other proteins with independent cytoskeletal interactions, were present in normal or increased amounts. To obtain direct evidence for the association of the band 3 and the Rh protein complexes in the RBC, we examined whether Rh complex proteins were coimmunoprecipitated with band 3 from membranes. RhAG and Rh were found to be efficiently coimmunoprecipitated with band 3 from deoxycholate-solubilized membranes. Results suggest that band 3 forms the core of a macrocomplex of integral and peripheral RBC membrane proteins. The presence of these proteins in a single structural macrocomplex makes it likely that they have linked functional or regulatory roles. We speculate that this macrocomplex may function as an integrated CO2/O-2 gas exchange unit (metabolon) in the erythrocyte. C1 Univ Bristol, Dept Biochem, Sch Med Sci, Bristol BS8 1TD, Avon, England. Univ Cambridge, Dept Hematol, Cambridge CB2 1TN, England. Ctr Hosp Coimbra, Unidade Hematol Mol, Serv Hematol, Coimbra, Portugal. Jackson Lab, Bar Harbor, ME 04609 USA. Univ Calif, Life Sci Div, Lawrence Berkeley Natl Lab, Berkeley, CA USA. Hop Bicetre, INSERM, U473, Fac Med Paris Sud, Le Kremlin Bicetre, France. Hop Bicetre, Fac Med Paris Sud, Serv Hematol Immunol & Cytogenet, Le Kremlin Bicetre, France. New York Blood Ctr, New York, NY 10021 USA. RP Tanner, MJA (reprint author), Univ Bristol, Dept Biochem, Sch Med Sci, Bristol BS8 1TD, Avon, England. OI Ribeiro, Maria Leticia/0000-0002-5964-5001; Bruce, Lesley/0000-0001-5922-7072 FU NHLBI NIH HHS [HL64885, HL31579, R01 HL064885]; NIDDK NIH HHS [DK26263, DK32094]; PHS HHS [DL56267] NR 56 TC 210 Z9 216 U1 2 U2 15 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1900 M STREET. NW SUITE 200, WASHINGTON, DC 20036 USA SN 0006-4971 J9 BLOOD JI Blood PD MAY 15 PY 2003 VL 101 IS 10 BP 4180 EP 4188 DI 10.1182/blood-2002-09-2824 PG 9 WC Hematology SC Hematology GA 677EB UT WOS:000182793000067 PM 12531814 ER PT J AU Stampfer, MR Yaswen, P AF Stampfer, MR Yaswen, P TI Human epithelial cell immortalization as a step in carcinogenesis SO CANCER LETTERS LA English DT Article DE telomerase; telomere; p53; epithelial cell; immortalization; senescence; agonescence; conversion; tumor; cancer; oncogenesis; tumorigenesis; tumor suppressor ID TELOMERASE REVERSE-TRANSCRIPTASE; HUMAN BREAST-CANCER; HUMAN PAPILLOMAVIRUS TYPE-16; PRIMARY HUMAN KERATINOCYTES; HUMAN FIBROBLASTS; DOWN-REGULATION; IN-VITRO; P16(INK4A) EXPRESSION; MOUSE TELOMERASE; P53 MUTATIONS AB Human epithelial cells encounter two senescence barriers that enforce a limited proliferative potential. A first barrier is mediated by the retinoblastoma protein, and can be overcome by multiple types of errors, many of which are observed in human cancers. A second, extremely stringent telomere-dependent barrier, is a consequence of repression of telomerase activity. Although relieved by ectopic hTERT expression, the nature of the errors required to overcome this latter barrier during in vivo carcinogenesis have not yet been defined. Attainment of immortality and telomerase reactivation are crucial to human carcinoma development; the derangements responsible for attainment of immortality may be rate-limiting and permissive for further progression to malignancy. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved. C1 Univ Calif Berkeley, Div Life Sci, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Stampfer, MR (reprint author), Univ Calif Berkeley, Div Life Sci, Lawrence Berkeley Lab, 1 Cyclotron Rd,70A1118, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA-24844] NR 83 TC 47 Z9 53 U1 1 U2 2 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3835 J9 CANCER LETT JI Cancer Lett. PD MAY 15 PY 2003 VL 194 IS 2 BP 199 EP 208 DI 10.1016/S0304-3835(02)00707-3 PG 10 WC Oncology SC Oncology GA 687VT UT WOS:000183398200008 PM 12757978 ER PT J AU Baczkowicz, M Wojtowicz, D Anderegg, JW Schilling, CH Tomasik, P AF Baczkowicz, M Wojtowicz, D Anderegg, JW Schilling, CH Tomasik, P TI Starch complexes with bismuth (III) and (V) SO CARBOHYDRATE POLYMERS LA English DT Article DE bismuth; potato starch; starch-metal complexes; thermogravimetric analysis AB Studies are presented on bismuth (III) and bismuth (V) derivatives of starch. Bismuth (III) derivatives of starch were prepared by reaction of either bismuth trichloride or bismuth tri-tert-pentoxide with either granular or activated potato starch. Bismuth (V) starch derivatives were prepared by heating a solid blend of activated starch and NaBiO3 in a microwave oven. Thermal analysis (thermogravimetry-TGA, differential thermogravimetry-DTGA, and differential thermal analysis-DTA) as well as IR- and X-ray photoelectron spectroscopies showed that starch reacted with bismuth (III) alkoxide by substitution of its one alkoxide group with one hydroxyl group of the D-glucose unit. D-Glucose units bound no more than two Bi(O-akyl)(2) groups. D-Glucose units reacted with BiCl3 in benzene with the evolution of hydrochloride which hydrolysed starch to dextrins. Starch was crosslinked on heating with sodium bismuthate. Bismuthated starches were slightly less thermally stable than original starches. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Univ Agr, Dept Chem, Krakow, Poland. Ames Lab, Ames, IA 50011 USA. Saginaw Valley State Univ, Dept Engn Mech, Univ Ctr, MI 48710 USA. RP Tomasik, P (reprint author), Univ Agr, Dept Chem, Krakow, Poland. NR 19 TC 19 Z9 20 U1 0 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0144-8617 J9 CARBOHYD POLYM JI Carbohydr. Polym. PD MAY 15 PY 2003 VL 52 IS 3 BP 263 EP 268 AR PII S0144-8617(02)00294-1 DI 10.1016/S0144-8617(02)00294-1 PG 6 WC Chemistry, Applied; Chemistry, Organic; Polymer Science SC Chemistry; Polymer Science GA 651FT UT WOS:000181310400007 ER PT J AU Roa, F Way, JD McCormick, RL Paglieri, SN AF Roa, F Way, JD McCormick, RL Paglieri, SN TI Preparation and characterization of Pd-Cu composite membranes for hydrogen separation SO CHEMICAL ENGINEERING JOURNAL LA English DT Article; Proceedings Paper CT 17th Meeting of the North-American-Catalysis-Society CY JUL, 2001 CL TORONTO, CANADA SP N Amer Catalysis Soc DE palladium; copper; palladium-copper alloy; composite membrane; electroless plating; hydrogen separation; gas separation; high temperature; asymmetric ceramic supports ID PALLADIUM-SILVER; METALLIC MEMBRANES; GAS SEPARATION; REACTORS; FABRICATION; DEPOSITION; CATALYSIS; ALUMINA; ALLOYS; AG AB Pd-Cu composite membranes were made by successive electroless deposition of Pd and then Cu onto various tubular porous ceramic supports. Ceramic filters used as supports included symmetric alpha-alumina (nominal 200 nm in pore size), asymmetric zirconia on alpha-alumina (nominal 50 nm pore size), and asymmetric gamma-alumina on alpha-alumina (nominal 5 nm pore size). The resulting metal/ceramic composite membranes were heat-treated between 350 and 700degreesC for times ranging from 6 to 25 days to induce intermetallic diffusion and obtain homogeneous metal films. Pure gas permeability tests were conducted using hydrogen and nitrogen. For an 11 mum thick, 10 wt.% Cu film on a nominal 50 nm pore size asymmetric ultrafilter with zirconia top layer, the flux at 450 degreesC and 345 kPa H-2 feed pressure was 0.8 mol/m(2) s. The ideal hydrogen/nitrogen separation factor was 1150 at the same conditions. The thickness of the metallic film was progressively decreased from 28 mum down to 1-2 mum and the alloy concentration was increased to 30 wt.% Cu. Structural factors related to the ceramic support and the metallic film chemical composition are shown to be responsible for the differences in membrane performance. Among the former are the support pore size, which controls the required metal film thickness to insure a leak-free membrane and the internal structure of the support (symmetric or asymmetric) which changes the mass transfer resistance. The support with the 200 nm pores required more Pd to plug the pores than the asymmetric membranes with smaller pore sizes, as was expected. However, leak-free films could not be deposited on the support with the smallest pore size (5 nm gamma-alumina), presumably due to surface defects and/or a lack of adhesion between the metal film and the membrane surface. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Way, JD (reprint author), Colorado Sch Mines, Dept Chem Engn, 1500 Illinois St, Golden, CO 80401 USA. RI McCormick, Robert/B-7928-2011 NR 61 TC 110 Z9 113 U1 5 U2 45 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1385-8947 J9 CHEM ENG J JI Chem. Eng. J. PD MAY 15 PY 2003 VL 93 IS 1 BP 11 EP 22 AR PII S1385-8947(02)00106-7 DI 10.1016/S1385-8947(02)00106-7 PG 12 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA 674LP UT WOS:000182638500003 ER PT J AU Hu, JL Wang, Y VanderWiel, D Chin, C Palo, D Rozmiarek, R Dagle, R Cao, J Holladay, J Baker, E AF Hu, JL Wang, Y VanderWiel, D Chin, C Palo, D Rozmiarek, R Dagle, R Cao, J Holladay, J Baker, E TI Fuel processing for portable power applications SO CHEMICAL ENGINEERING JOURNAL LA English DT Article; Proceedings Paper CT 17th Meeting of the North-American-Catalysis-Society CY JUL, 2001 CL TORONTO, CANADA SP N Amer Catalysis Soc DE fuel processing; portable power applications ID METHANOL AB The present work focuses on fuel processing at a very short contact time (GHSV = 36,000-144,000 h(-1)) and a relatively lower temperature (<500degreesC). More than 95% conversion can be achieved by steam reforming of clean fuels, such as isooctane and synthetic diesel. A unique characteristic of the current catalytic system is the flexibility in steaming reforming of different hydrocarbon fuels under different conditions. High efficiency methanol steam reforming catalyst performance has been demonstrated which implies a feasibility in designing a high performance methanol steam reformer with reduced volume for portable device applications. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hu, JL (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd MSIN K8-93, Richland, WA 99352 USA. RI Wang, Yong/C-2344-2013 NR 22 TC 41 Z9 41 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1385-8947 J9 CHEM ENG J JI Chem. Eng. J. PD MAY 15 PY 2003 VL 93 IS 1 BP 55 EP 60 AR PII S1385-8947(02)00108-0 DI 10.1016/S1385-8947(02)00108-0 PG 6 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA 674LP UT WOS:000182638500007 ER PT J AU Plimpton, SJ Seidel, DB Pasik, MF Coats, RS Montry, GR AF Plimpton, SJ Seidel, DB Pasik, MF Coats, RS Montry, GR TI A load-balancing algorithm for a parallel electromagnetic particle-in-cell code SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE particle-in-cell; electromagnetics; plasma simulation; load-balancing; parallel computing ID SIMULATION CODES; COMPUTERS AB Particle-in-cell simulations often suffer from load-imbalance on parallel machines due to the competing requirements of the field-solve and particle-push computations. We propose a new algorithm that balances the two computations independently. The grid for the field-solve computation is statically partitioned. The particles within a processor's sub-domain(s) are dynamically balanced by migrating spatially-compact groups of particles from heavily loaded processors to lightly loaded ones as needed. The algorithm has been implemented in the QUICKSILVER electromagnetic particle-in-cell code. We provide details of the implementation and present performance results for QUICKSILVER running models with up to a billion grid cells and particles on thousands of processors of a large distributed-memory parallel machine. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. SW Software, Albuquerque, NM 87111 USA. RP Plimpton, SJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 22 TC 17 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD MAY 15 PY 2003 VL 152 IS 3 BP 227 EP 241 DI 10.1016/S0010-4655(02)00795-6 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 672TZ UT WOS:000182540100001 ER PT J AU Gilder, S Rousse, S Farber, D McNulty, B Sempere, T Torres, V Palacios, O AF Gilder, S Rousse, S Farber, D McNulty, B Sempere, T Torres, V Palacios, O TI Post-Middle Oligocene origin of paleomagnetic rotations in Upper Permian to Lower Jurassic rocks from northern and southern Peru SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE palcomagnetism; Andes; Altiplano; tectonics; Permian; Triassic; Jurassic; Peru; South America ID CENTRAL ANDES; TECTONIC ROTATIONS; BOLIVIAN OROCLINE; CORDILLERA; ARGENTINA; EVOLUTION; PATAGONIA; AMERICA; BELT; GEOCHRONOLOGY AB We report paleomagnetic data from 28 sites of Upper Permian to Lower Jurassic strata from northern and southern Peru. In northern Peru (6degreesS), a stable magnetic component from six Permo-Triassic sites passes fold and reversal tests. The overall mean pole agrees well with Late Permian to Triassic poles from cratonal South America, suggesting this part of Peru has experienced neither significant rotation nor * latitudinal transport since the Permo-Triassic. In southern Peru (13 to 16degreesS), thermal demagnetization isolates stable magnetic components in 16 of 22 Upper Permian to Lower Jurassic sites collected along the transition between the Altiplano and the Eastern Cordillera. These 16 sites are rotated 14 to 147degrees counterclockwise and pass an inclinations-only fold test. Within the same structural zone, three other Permo-Triassic sites as well as 10 Paleocene sites also show important counterclockwise rotations [Roperch and Carlier, J. Geophys. Res. 97 (1992) 17233-17249; Butler et al., Geology 23 (1995) 799-802]. The large magnitude and exclusively counterclockwise sense of rotation suggest that the tectonic regime included an important sinistral shear component. No correlation exists between rotation amount and rock age, suggesting the rotations are post-Paleocene in age. Because the rotations occur along the fringe of the Eastern Cordillera, they were likely produced during its structural formation, hence from the Late Oligocene to Present. Sinistral shear acting in the northern part of the Bolivian Orocline appears much more pronounced than that north of the Abancay Deflection, which likely arises from differences in convergence obliquity. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Inst Phys Globe, Lab Paleomagnetisme, F-75252 Paris 05, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Calif State Univ Dominguez Hills, Dept Earth Sci, Carson, CA 90747 USA. IRD, Lima 18, Peru. Inst Geol Minero & Met, INGEMMET, Lima 41, Peru. RP Gilder, S (reprint author), Inst Phys Globe, Lab Paleomagnetisme, 4 Pl Jussieu, F-75252 Paris 05, France. RI Farber, Daniel/F-9237-2011; Sempere, Thierry/B-7211-2014; Gilder, Stuart/B-1871-2016 OI Gilder, Stuart/0000-0001-8724-7812 NR 64 TC 25 Z9 25 U1 0 U2 4 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 MAY 15 PY 2003 VL 210 IS 1-2 BP 233 EP 248 DI 10.1016/S0012-821X(03)00102-X PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 681VL UT WOS:000183056200017 ER PT J AU Xu, CC Fan, JL Riekhof, W Froehlich, JE Benning, C AF Xu, CC Fan, JL Riekhof, W Froehlich, JE Benning, C TI A permease-like protein involved in ER to thylakoid lipid transfer in Arabidopsis SO EMBO JOURNAL LA English DT Article DE chloroplast envelopes; lipid arrays; lipid permease; lipid trafficking; thylakoid lipids ID BIOSYNTHESIS; THALIANA; SYNTHASE; MUTANT; PLANTS; DIGALACTOSYLDIACYLGLYCEROL; METABOLISM; DEFICIENT; DIACYLGLYCEROL; GALACTOLIPIDS AB In eukaryotes, enzymes of different subcellular compartments participate in the assembly of membrane lipids. As a consequence, interorganelle lipid transfer is extensive in growing cells. A prominent example is the transfer of membrane lipid precursors between the endoplasmic reticulum (ER) and the photosynthetic thylakoid membranes in plants. Mono- and digalactolipids are typical photosynthetic membrane lipids. In Arabidopsis, they are derived from one of two pathways, either synthesized de novo in the plastid, or precursors are imported from the ER, giving rise to distinct molecular species. Employing a high-throughput robotic screening procedure generating arrays of spot chromatograms, mutants of Arabidopsis were isolated, which accumulated unusual trigalactolipids. In one allelic mutant subclass, trigalactosyldiacylglycerol1, the primary defect caused a disruption in the biosynthesis of ER-derived thylakoid lipids. Secondarily, a processive galactosyltransferase was activated, leading to the accumulation of oligogalactolipids. Mutations in a permease-like protein of the outer chloroplastic envelope are responsible for the primary biochemical defect. It is proposed that this protein is part of a lipid transfer complex. C1 Michigan State Univ, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. RP Michigan State Univ, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. EM benning@msu.edu NR 35 TC 124 Z9 127 U1 1 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0261-4189 EI 1460-2075 J9 EMBO J JI Embo J. PD MAY 15 PY 2003 VL 22 IS 10 BP 2370 EP 2379 DI 10.1093/emboj/cdg234 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 680BU UT WOS:000182957100007 PM 12743031 ER PT J AU Smith, KP Arnish, JJ Williams, GP Blunt, DL AF Smith, KP Arnish, JJ Williams, GP Blunt, DL TI Assessment of the disposal of radioactive petroleum industry waste in nonhazardous landfills using risk-based modeling SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SCALE AB Certain petroleum production activities cause naturally occurring radioactive materials (NORM) to accumulate in concentrations above natural background levels, making safe and cost-effective management of such technologically enhanced NORM (TENORM) a key issue for the petroleum industry. As a result, both industry and regulators are interested in identifying cost-effective disposal alternatives that provide adequate protection of human health and the environment. One such alternative, currently allowed in Michigan with restrictions, is the disposal of TENORM wastes in nonhazardous waste landfills. The disposal of petroleum industry wastes containing radium-226 (Ra226) in nonhazardous landfills was modeled to evaluate the potential radiological doses and health risks to workers and the public. Multiple scenarios were considered in evaluating the potential risks associated with landfill operations and the future use of the property. The scenarios were defined, in part, to evaluate the Michigan policy; sensitivity analyses were conducted to evaluate the impact of key parameters on potential risks. The results indicate that the disposal of petroleum industry TENORM wastes in nonhazardous landfills in accordance with the Michigan policy and existing landfill regulations presents a negligible risk to most of the potential receptors considered in this study. C1 Argonne Natl Lab, Environm Assessment Div, Argonne, IL 60439 USA. RP Smith, KP (reprint author), Argonne Natl Lab, Environm Assessment Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Williams, Gustavious/P-7252-2014 OI Williams, Gustavious/0000-0002-2781-0738 NR 17 TC 18 Z9 20 U1 4 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY 15 PY 2003 VL 37 IS 10 BP 2060 EP 2066 DI 10.1021/es0261729 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 678KJ UT WOS:000182866000005 PM 12785508 ER PT J AU Fischer, ML Littlejohn, D Lunden, MM Brown, NJ AF Fischer, ML Littlejohn, D Lunden, MM Brown, NJ TI Automated measurements of ammonia and nitric acid in indoor and outdoor air SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID EFFLUENT DIFFUSION DENUDER; ION CHROMATOGRAPHY; AEROSOL; NITRATE; GAS; POLLUTANTS; COLLECTION; ATMOSPHERE; PARTICLES; NO2 AB Simultaneous temporally resolved indoor and outdoor measurements of ammonia and nitric acid are valuable for determining the gas-particle equilibrium conditions governing concentrations of ammonium nitrate aerosol. We report the results of simultaneous automated indoor and outdoor measurements of ammonia and nitric acid concentrations made at an unoccupied, single-story residence in Clovis, CA during three periods from October 2000 to January 2001. The measurements were conducted as part of a controlled study to explore mechanisms governing indoor concentrations of fine aerosols of outdoor origin. The gas-phase measurements were performed using diffusion denuders and ion chromatography with 30 min temporal resolution and detection limits below 1 ppb. The conditions of the field experiment span a wide range of outdoor climate as well as natural and forced indoor conditions. During all periods ammonia concentrations were generally slightly higher indoors than out, with both outdoor and indoor concentrations varying in a range from approximately 5 to 30 ppb. Nitric acid was only detected in outdoor air in October 2000, at concentrations up to 3 ppb. During the October period, the product of outdoor nitric acid and ammonia concentrations sometimes deviated from that expected for equilibrium between gas and ammonium nitrate particulate phases and the degree and direction of disequilibrium were correlated with trends in air temperature. The consistently low indoor concentrations of nitric acid were not consistent with equilibrium between gas and particle phases and suggest that a combination of low penetration into the building and a high loss rate for nitric acid reduce indoor concentrations significantly below those outdoors. C1 Ernest Orlando Lawrence Berkeley Lab, Dept Atmospher Sci, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Fischer, ML (reprint author), Ernest Orlando Lawrence Berkeley Lab, Dept Atmospher Sci, Environm Energy Technol Div, Bldg 51R0208,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM mlfischer@lbl.gov NR 33 TC 7 Z9 7 U1 4 U2 10 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 MAY 15 PY 2003 VL 37 IS 10 BP 2114 EP 2119 DI 10.1021/es026133x PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 678KJ UT WOS:000182866000012 PM 12785515 ER PT J AU Templeton, AS Spormann, AM Brown, GE AF Templeton, AS Spormann, AM Brown, GE TI Speciation of Pb(II) sorbed by Burkholderia cepacia/goethite composites SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHEMICAL-EQUILIBRIUM MODEL; GOETHITE ALPHA-FEOOH; ORGANIC-MATTER; HUMIC SUBSTANCES; WATER INTERFACE; SURFACE COMPLEXATION; BACTERIAL SURFACES; METAL ADSORPTION; IRON-OXIDES; SORPTION AB Bacterial-mineral composites are important in the retention of heavy metals such as Pb due to their large sorption capacity under a wide range of environmental conditions. However, the partitioning of heavy metals between components in such composites is not probed directly. Using Burkholderia cepacia biofilms coated with goethite (alpha-FeOOH) particles, the partitioning of Pb(II) between the biological and iron-(oxyhydr)oxide surfaces has been measured using an X-ray spectroscopic approach. EXAFS spectra were fit to quantitatively determine the fraction of Pb(II) associated with each component as a function of pH and [Pb]. At pH <5.5, at least 50% of the total sorbed Pb(II) is associated with the biofilm component, whereas the total uptake within the composite is dominated by goethite (>70% Pb/goethite) above pH 6. Direct comparison can be made between the amount of Pb(II) bound to each component in the composite vs separate binary systems (i.e., Pb/biofilm or Pb/goethite). At high pH, Pb(II) uptake on the biofilm is dramatically decreased due to competition with the goethite surface. In contrast, Pb uptake on goethite is significantly enhanced at low pH (2-fold increase at pH 5) compared to systems with no complexing ligands. The mode of Pb(II)-binding to the goethite component changes from low to high [Pb]. Structural fitting of the EXAFS spectra collected from 10(-5.6) to 10(-3.6) M [Pb](eq) at pH 6 shows that the Pb-goethite surface complexes at low [Pb] are dominated by inner-sphere bidentate, binuclear complexes bridging two adjacent singly coordinated surface oxygens, giving rise to Pb-Fe distances of similar to3.9 Angstrom. At high [Pb], the dominant Pb(II) inner-sphere complexes on the goethite surface shift to bidentate edge-sharing complexes with Pb-Fe distances of similar to3.3 Angstrom. C1 Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94035 USA. Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, SLAC, Menlo Pk, CA 94025 USA. RP Templeton, AS (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Marine Biol Res Div, 9500 Gilman Dr, La Jolla, CA 92093 USA. OI TEMPLETON, ALEXIS/0000-0002-9670-0647 NR 39 TC 43 Z9 44 U1 3 U2 28 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY 15 PY 2003 VL 37 IS 10 BP 2166 EP 2172 DI 10.1021/es026081b PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 678KJ UT WOS:000182866000020 PM 12785522 ER PT J AU Cantrell, KJ Yabusaki, SB Engelhard, MH Mitroshkov, AV Thornton, EC AF Cantrell, KJ Yabusaki, SB Engelhard, MH Mitroshkov, AV Thornton, EC TI Oxidation of H2S by iron oxides in unsaturated conditions SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MECHANISM; HYDROXIDE AB Previous studies have demonstrated that gas-phase H2S can immobilize certain redox-sensitive contaminants (e.g., Cr, U, Tc) in vadose zone environments. A key issue for effective and efficient delivery of H2S in these environments is the reactivity of the gas with indigenous iron oxides. To elucidate the factors that control the transport of H2S in the vadose zone, laboratory column experiments were conducted to identify reaction mechanisms and measure rates of H2S oxidation by iron oxide-coated sands using several carrier gas compositions (N-2, air, and O-2) and flow rates. Most experiments were conducted using ferrihydrite-coated sand. Additional studies were conducted with goethite- and hematite-coated sand and a natural sediment. Selective extractions were conducted at the end of each column experiment to determine the mass balance of the reaction products. XPS was used to confirm the presence of the reaction products. For column experiments in which ferrihydrite-coated sand was the substrate and N-2 was the carrier gas, the major H2S oxidation products were FeS and elemental sulfur (mostly S-8(0), represented as S-0 for simplicity) at ratios that were consistent with the stoichiometry of the postulated reactions. When air or O-2 were used as the carrier gas, S-0 became the dominant reaction product along with FeS2 and smaller amounts of FeS, sulfate, and thiosulfate. A mathematical model of reactive transport was used to test the hypothesis that S-0 forming on the iron oxide surfaces reduces access of H2S to the reactive surface. Several conceptual models were assessed in the context of the postulated reactions with the final model based on a linear surface poisoning model and fitted reaction rates. These results indicate that carrier gas selection is a critical consideration with significant tradeoffs for remediation objectives. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Cantrell, KJ (reprint author), Pacific NW Natl Lab, POB 999,Mail Stop K6-81, Richland, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; OI Engelhard, Mark/0000-0002-5543-0812 NR 20 TC 31 Z9 32 U1 1 U2 30 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY 15 PY 2003 VL 37 IS 10 BP 2192 EP 2199 DI 10.1021/es020994o PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 678KJ UT WOS:000182866000023 PM 12785525 ER PT J AU Coleman, SJ Coronado, PR Maxwell, RS Reynolds, JG AF Coleman, SJ Coronado, PR Maxwell, RS Reynolds, JG TI Granulated activated carbon modified with hydrophobic silica aerogel-potential composite materials for the removal of uranium from aqueous solutions SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID EXTRACTION CHROMATOGRAPHY; HYDROXYAPATITE; GEL; REMEDIATION; ADSORPTION; SEDIMENTS; SORPTION; SOILS AB Aqueous solutions of 100 parts per billion (ppb) uranium at pH 7 were treated with granulated activated carbon (GAC) that had been modified with various formulations of hydrophobic aerogels. The composite materials were found to be superior in removing uranium from a stock solution compared to GAC alone evaluated by a modified ASTM D 3860-98 method for batch testing. The testing results were evaluated using a Freundlich adsorption model. The best performing material has parameters of n = 2.87 and K-f = 1169 compared to n = 1.00, and K-f = 20 for GAC alone. The composite materials were formed by mixing (CH3O)(4)Si with the hydrophobic sol-gel precursor, (CH3O)(3)SiCH2CH2CF3 and with specified modifiers, such as H3PO4, Ca(NO3)(2), and (C2H5O)(3)SiCH2CH2P(O)(OC2H5)(2), gelation catalysts, and GAC in a supercritical reactor system. After gelation, supercritical extraction, and sieving, the composites were tested. Characterization by FTIR and P-31 NMR indicate the formation of phosphate in the case of the H3PO4 and Ca(NO3)(2) composites and phosphonic acid related compounds in the phosphonate composite. These composite materials have potential application in the clean up of groundwater at DOE and other facilities. C1 Lawrence Livermore Natl Lab, Forens Sci Ctr, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Environm Restorat Div Chem & Mat Sci Directorate, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Chem Engn Div, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Mat Sci Directorate, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Analyt & Nucl Chem Div, Livermore, CA 94551 USA. RP Reynolds, JG (reprint author), Lawrence Livermore Natl Lab, Forens Sci Ctr, POB 808,L-178, Livermore, CA 94551 USA. NR 39 TC 38 Z9 39 U1 2 U2 39 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY 15 PY 2003 VL 37 IS 10 BP 2286 EP 2290 DI 10.1021/es020929e PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 678KJ UT WOS:000182866000036 PM 12785538 ER PT J AU Gu, BH Dong, WJ Brown, GM Cole, DR AF Gu, BH Dong, WJ Brown, GM Cole, DR TI Complete degradation of perchlorate in ferric chloride and hydrochloric acid under controlled temperature and pressure SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID REDUCTION AB Despite favorable thermodynamics, the reduction of perchlorate (ClO4-) is kinetically limited in aqueous media because of its high activation energy. In this paper, a new methodology has been presented for degrading ClO4- in an FeCl3-HCl solution at an elevated temperature (<200 degreesC) and/or pressure (similar to20 atm). Results indicate that the rate constant for the pseudo-first-order reaction between ClO4- and ferrous Fe(II) (in excess) increased nearly 3 orders of magnitude when the temperature was increased from 110 to 195 degreesC, and a complete reduction of ClO4- occurred in <1 h at 195 degreesC in the FeCl3-HCl solution. The activation energy of the reaction was calculated to be about 120 kJ/mol. Additionally, a flow-through reactor was constructed based on the batch kinetic measurements, and a nearly complete degradation of ClO4- was observed under continuous-flow mode. Because the FeCl3-HCl solution has been successfully used in regenerating selective anion-exchange resins sorbed with ClO4- during water treatment, this new methodology offers a cost-effective means to degrade ClO4- while not altering the chemical properties of the FeCl3-HCl regenerant solution so it can be reused, eliminating the production of secondary wastes. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gu, BH (reprint author), Oak Ridge Natl Lab, POB 2008,MS-6036, Oak Ridge, TN 37831 USA. RI Gu, Baohua/B-9511-2012 OI Gu, Baohua/0000-0002-7299-2956 NR 14 TC 56 Z9 58 U1 2 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY 15 PY 2003 VL 37 IS 10 BP 2291 EP 2295 DI 10.1021/es0262378 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 678KJ UT WOS:000182866000037 PM 12785539 ER PT J AU O'Connell, SP Lehman, RM Snoeyenbos-West, O Winston, VD Cummings, DE Watwood, ME Colwell, FS AF O'Connell, SP Lehman, RM Snoeyenbos-West, O Winston, VD Cummings, DE Watwood, ME Colwell, FS TI Detection of Euryarchaeota and Crenarchaeota in an oxic basalt aquifer SO FEMS MICROBIOLOGY ECOLOGY LA English DT Article DE archaeon; oxic; subsurface; aquifer; 16S rDNA; denaturing gradient gel electrophoresis ID GRADIENT GEL-ELECTROPHORESIS; RIBOSOMAL-RNA GENES; PHYLOGENETIC DIVERSITY; PCR AMPLIFICATION; DNA EXTRACTION; ARCHAEA; SOIL; LAKE; BACTERIAL; BACTERIOPLANKTON AB Groundwater from an oxic, fractured basalt aquifer was examined for the presence of Archaea. DNA was extracted from cells concentrated from groundwater collected from five wells penetrating the eastern Snake River Plain Aquifer (Idaho, USA). Polymerase chain reaction (PCR) amplification of 16S rDNA was performed with Archaea-specific primers using both nested (ca. 200-bp product) and direct (ca. 600-bp product) PCR approaches. Estimates of the archaeal diversity were made by separating PCR products from all five wells by denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis of partial 16S rDNA sequences from two wells was performed following cloning procedures. Archaea were detected in all wells and the number of DGGE bands per well ranged from two to nine and varied according to PCR approach. There were 30 unique clonal 16S rDNA partial sequences (ca. 600 bp) within a total of 100 clones that were screened from two wells. Twenty-two of the 16S rDNA fragments recovered from the aquifer were related to the Crenarchaeota and Euryarchaeota kingdoms (one large clade of clones in the former and six smaller clades in the latter), with sequences ranging from 23.7 to 95.4% similar to those found in other investigations. The presence of potentially thermophilic or methanogenic Archaea in this fully oxic aquifer may be related to deep thermal sources or elevated dissolved methane concentrations. Many sequences were similar to those that represent non-thermophilic Crenarchaeota of which there are no known cultured members and therefore no putative function. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. Smith Coll, Dept Biol, Northampton, MA 01063 USA. Idaho State Univ, Dept Biol, Pocatello, ID 83209 USA. RP O'Connell, SP (reprint author), Western Carolina Univ, 132 Nat Sci Bldg, Cullowhee, NC 28723 USA. OI Lehman, Michael/0000-0002-3391-3178; Snoeyenbos-West, Oona/0000-0001-9146-7244 NR 54 TC 21 Z9 22 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD MAY 15 PY 2003 VL 44 IS 2 BP 165 EP 173 DI 10.1016/S0168-6496(02)00465-8 PG 9 WC Microbiology SC Microbiology GA 674PY UT WOS:000182646200003 PM 19719634 ER PT J AU Lang, RF Ju, TD Bryan, JC Kubas, GJ Hoff, CD AF Lang, RF Ju, TD Bryan, JC Kubas, GJ Hoff, CD TI Oxidative addition of thiols, and thiol/thiolate exchange reactions of low valent molybdenum and tungsten complexes. Synthetic, structural and calorimetric study of trigonal prismatic W(CO)(2)(1,10-phenanthroline) (3,4-toluenedithiolate) SO INORGANICA CHIMICA ACTA LA English DT Article DE oxidative addition; molybdenum complexes; tungsten complexes ID MOLECULAR-STRUCTURE; HYDROGEN IODIDE; MONONUCLEAR; DISULFIDES; RADICALS; MO AB Reactions of W(CO)(3)(phen)(EtCN) with butane thiols, thiophenol, 1,2-benzenedithiol, and 3,4-toluenedithiol have been investigated. Reaction of butanethiol results in simple ligand exchange to form the thiol complex W(CO3)(phen)((BuSH)-Bu-0 or 1). Reaction with thiophenol results in oxidative addition to form the W(II) thiolate hydride complex W (CO3)(phen)(SPh)(H). The lower reducing power of Mo compared to W is demonstrated in that simple ligand binding of PhSH to Mo(0) occurs forming Mo(CO)(3)(phen)(PhSH). Reactions of arene dithiols with W(CO3)(phen)(EWN) were found to proceed with initial oxidative addition of one S-H bond of the chelating dithiols to form W(CO)(3)(phen)(H)[S-arene(SH)]. These complexes slowly eliminate H, and CO to form W(CO)(2)(phen)(arenedithiolate) complexes. The same complexes can be formed by thiol/thiolate exchange reactions: W(CO)(2)(phen)(SR)(2) (R = Bu-t, Ph) react quantitatively with arene dithiol to yield W(CO)(2)(phen)(arenedithiolate). The crystal structure of W(CO)(2)(phen)(3,4-toluenedithiolate) has been determined and is trigonal prismatic rather than octahedral. Values for DeltaHdegrees (thiol/thiolate exchange) have been measured by solution calorimetry relative to W(CO)(2)(phen)((SBu)-Bu-t)(2) = 0.0 kcal mol (CO)(2)(phen)(SPh)(2) = - 7.2 +/- 0.4 kcal mol (- 1) and W(CO)(2)(phen)(3.4-toluenedithiolate) - 12.5 +/- 0.6 kcal mol (-1). (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Miami, Dept Chem, Coral Gables, FL 33126 USA. Kos Pharmaceut, Hollywood, FL 33324 USA. Univ Wisconsin, Dept Chem, La Crosse, WI 54601 USA. Los Alamos Natl Lab, CSIC, Los Alamos, NM 87545 USA. RP Kubas, GJ (reprint author), Univ Miami, Dept Chem, Coral Gables, FL 33126 USA. NR 19 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD MAY 15 PY 2003 VL 348 BP 157 EP 164 DI 10.1016/S0020-1693(02)01489-5 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 680XG UT WOS:000183004900022 ER PT J AU Sakakita, H Craig, D Anderson, JK Biewer, TM Terry, SD Chapman, BE Den-Hartog, DJ Prager, SC AF Sakakita, H Craig, D Anderson, JK Biewer, TM Terry, SD Chapman, BE Den-Hartog, DJ Prager, SC TI Behavior of impurity ion velocities during the pulsed poloidal current drive in the Madison symmetric torus reversed-field pinch SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS LA English DT Article DE plasma velocity; ion temperature; impurity emission; equilibrium reconstruction; pulsed poloidal current drive; reversed field pinch ID FLUCTUATIONS; CONFINEMENT; TRANSPORT AB We report on passive measurements of impurity ion velocities during the pulsed poloidal current drive (PPCD) in the Madison Symmetric Torus reversed-field pinch. During PPCD, the electron temperature increased and a sudden reduction of magnetic fluctuations was observed. For this change, we have studied whether plasma velocity is affected. Plasma rotation is observed to decrease during PPCD. From measurements of line intensities for several impurities at 10 poloidal chords, it is found that the impurity line emission shifts outward. The ion temperature of impurities is reasonably connected to that measured by charge exchange recombination spectroscopy from core to edge. C1 Natl Inst Adv Ind Sci & Technol, Energy Elect Inst, Tsukuba, Ibaraki 3058568, Japan. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Sakakita, H (reprint author), Natl Inst Adv Ind Sci & Technol, Energy Elect Inst, 1-1-1 Umezono, Tsukuba, Ibaraki 3058568, Japan. NR 11 TC 0 Z9 0 U1 0 U2 0 PU INST PURE APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG, 4-24-8 SHINBASHI, MINATO-KU TOKYO, 105-004, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. PD MAY 15 PY 2003 VL 42 IS 5B BP L505 EP L507 DI 10.1143/JJAP.42.L505 PG 3 WC Physics, Applied SC Physics GA 693YE UT WOS:000183745300004 ER PT J AU Leung, WY Kang, H Constant, K Cann, D Kim, CH Biswas, R Sigalas, MM Ho, KM AF Leung, WY Kang, H Constant, K Cann, D Kim, CH Biswas, R Sigalas, MM Ho, KM TI Fabrication of photonic band gap crystal using microtransfer molded templates SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB We have proposed and demonstrated an economical technique to fabricate a three-dimensional layer-by-layer photonic band gap structure in the infrared wavelengths. An organic polymer template structure, an inverse layer-by-layer photonic crystal structure, is assembled using the microtransfer molding technique. This template is infiltrated with sol-gel or nanoparticle titanium oxide slurry, then later removed by heat treatment at a temperature range of 550-800 degreesC. This method can be extended to fabricate photonic crystals operating at optical and ultraviolet frequencies. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ctr Microelect Res, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Agilent Lab, Palo Alto, CA 94304 USA. RP Leung, WY (reprint author), Iowa State Univ, Ctr Microelect Res, Ames, IA 50011 USA. RI Constant, Kristen/C-3673-2014 OI Constant, Kristen/0000-0001-7138-9365 NR 9 TC 13 Z9 13 U1 4 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 MAY 15 PY 2003 VL 93 IS 10 BP 5866 EP 5870 DI 10.1063/1.1568548 PN 1 PG 5 WC Physics, Applied SC Physics GA 677CQ UT WOS:000182789700003 ER PT J AU Lin, YS Puthenkovilakam, R Chang, JP Bouldin, C Levin, I Nguyen, NV Ehrstein, J Sun, Y Pianetta, P Conard, T Vandervorst, W Venturo, V Selbrede, S AF Lin, YS Puthenkovilakam, R Chang, JP Bouldin, C Levin, I Nguyen, NV Ehrstein, J Sun, Y Pianetta, P Conard, T Vandervorst, W Venturo, V Selbrede, S TI Interfacial properties of ZrO(2) on silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TA2O5 THIN-FILMS; ZIRCONIUM-OXIDE FILMS; GATE DIELECTRICS; THERMAL-STABILITY; ELECTRICAL-PROPERTIES; SPECTROSCOPIC ELLIPSOMETRY; LEAKAGE CURRENT; REDUCTION; DECOMPOSITION; INTEGRATION AB The interface of zirconium oxide thin films on silicon is analyzed in detail for their potential applications in the microelectronics. The formation of an interfacial layer of ZrSi(x)O(y) with graded Zr concentration is observed by the x-ray photoelectron spectroscopy and secondary ion mass spectrometry analysis. The as-deposited ZrO(2)/ZrSi(x)O(y)/Si sample is thermally stable up to 880 degreesC, but is less stable compared to the ZrO(2)/SiO(2)/Si samples. Post-deposition annealing in oxygen or ammonia improved the thermal stability of as-deposited ZrO(2)/ZrSi(x)O(y)/Si to 925 degreesC, likely due to the oxidation/nitridation of the interface. The as-deposited film had an equivalent oxide thickness of similar to1.3 nm with a dielectric constant of similar to21 and a leakage current of 3.2x10(-3) A/cm(2) at -1.5 V. Upon oxygen or ammonia annealing, the formation of SiO(x) and SiH(x)N(y)O(z) at the interface reduced the overall dielectric constants. (C) 2003 American Institute of Physics. C1 Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. IMEC, B-3001 Louvain, Belgium. Mattson Technol Inc, Fremont, CA 94538 USA. RP Lin, YS (reprint author), Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. RI Levin, Igor/F-8588-2010 NR 59 TC 48 Z9 50 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 5945 EP 5952 DI 10.1063/1.1563844 PN 1 PG 8 WC Physics, Applied SC Physics GA 677CQ UT WOS:000182789700015 ER PT J AU Liao, XZ Serquis, A Zhu, YT Huang, JY Civale, L Peterson, DE Mueller, FM Xu, HF AF Liao, XZ Serquis, A Zhu, YT Huang, JY Civale, L Peterson, DE Mueller, FM Xu, HF TI Mg(B,O)(2) precipitation in MgB2 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CRITICAL-CURRENT DENSITY; SUPERCONDUCTING PROPERTIES; THIN-FILMS; DEFECTS; FIELD; MICROSTRUCTURE AB MgB2 samples prepared by solid-state reaction were investigated using high-resolution transmission electron microscopy (HREM), x-ray energy-dispersive spectroscopy (EDX), electron energy-loss spectroscopy (EELS), and energy-filtered imaging. Large amounts of coherent precipitates with a size range from about 5 nm up to about 100 nm were found in the MgB2 crystallite matrices. The precipitates are of different shapes including sphere, ellipsoid, and faceted polyhedron depending on the size of the precipitates. EDX and EELS analyses confirm that smaller precipitates contain magnesium, boron and oxygen while larger faceted precipitates contain mainly magnesium and oxygen, implying that the oxygen content increases with precipitate size. HREM and electron diffraction investigations found that the precipitates have the same crystal lattice structure as that of MgB2 but with various composition modulations depending on the composition of the precipitates. The precipitates transform to the MgO phase after long exposure to residual oxygen in flowing Ar gas at high temperatures. The effect of the precipitates in different size ranges on flux pinning is discussed. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Supercond Technol Ctr, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. RP Liao, XZ (reprint author), Los Alamos Natl Lab, Supercond Technol Ctr, POB 1663, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Liao, Xiaozhou/B-3168-2009; Huang, Jianyu/C-5183-2008; Serquis, Adriana/L-6554-2015 OI Zhu, Yuntian/0000-0002-5961-7422; Liao, Xiaozhou/0000-0001-8565-1758; Serquis, Adriana/0000-0003-1499-4782 NR 26 TC 65 Z9 68 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6208 EP 6215 DI 10.1063/1.1568528 PN 1 PG 8 WC Physics, Applied SC Physics GA 677CQ UT WOS:000182789700055 ER PT J AU Wang, CM Thevuthasan, S Shutthanandan, V Cavanagh, A Jiang, W Thomas, LE Weber, WJ AF Wang, CM Thevuthasan, S Shutthanandan, V Cavanagh, A Jiang, W Thomas, LE Weber, WJ TI Microstructure of precipitated au nanoclusters in MgO SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; ION-IMPLANTED SILICA; OPTICAL-PROPERTIES; GOLD NANOCLUSTERS; NONLINEAR OPTICS; FUSED-SILICA; COLLOIDAL AU; NANOCRYSTALS; SEMICONDUCTOR; ABSORPTION AB Gold nanoclusters dispersed in single crystal MgO have been prepared by ion implantation at 975 K and subsequent annealing at 1275 K for 10 h. The morphological features, size, and crystallographic orientation of the Au nanoclusters with respect to the MgO matrix, as well as the interface structure between the Au nanoclusters and MgO, have been investigated using transmission electron microscopy. During annealing, the Au clusters nucleate coherently in the MgO lattice, leading to an epitaxial orientation relationship of [010](MgO)//[010](Au) and (200)(MgO)//(200)(Au) that is maintained for all the Au clusters. Above a critical size of similar to5 to 8 nm, a coherent-semicoherent interface transition is observed for the Au clusters in MgO. This critical cluster size is larger than the critical size similar to3 nm based on energetic considerations. This discrepancy is discussed with respect to the point and extended defect structures at the interface between the Au clusters and the MgO matrix. The Au clusters larger than this critical size exhibit faceting on the {001} planes and internal dislocations. It is further suggested that the density of quantum antidots should depend on the size of the Au clusters. (C) 2003 American Institute of Physics. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Wang, CM (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 38 TC 19 Z9 19 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6327 EP 6333 DI 10.1063/1.1569032 PN 1 PG 7 WC Physics, Applied SC Physics GA 677CQ UT WOS:000182789700073 ER PT J AU Satyam, PV Kamila, J Mohapatra, S Satpati, B Goswami, DK Dev, BN Cook, RE Assoufid, L Wang, J Mishra, NC AF Satyam, PV Kamila, J Mohapatra, S Satpati, B Goswami, DK Dev, BN Cook, RE Assoufid, L Wang, J Mishra, NC TI Crater formation in gold nanoislands due to MeV self-ion irradiation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INDUCED GRAIN-GROWTH; HEAVY-IONS; IMPACTS; BOMBARDMENT; AU; SPIKES; DISPLACEMENT; DEFORMATION; DEPENDENCE; CASCADES AB The modification of gold nanoislands, grown on silicon substrates under high-vacuum conditions, by MeV self-ion irradiation has been studied by using scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and x-ray reflectivity. Upon irradiation with 1.5 MeV Au2+, two types of craters are observed on the Au islands: Empty craters and craters with a central hillock. The contribution of plastic flow, pressure spike, and sputtering to the crater formation during the ion impacts on the gold islands is analyzed. Thermal spike confinement within the gold islands is also proposed to be one of the possible reasons for crater formation in nanoislands. (C) 2003 American Institute of Physics. C1 Inst Phys, Bhubaneswar 751005, Orissa, India. Argonne Natl Lab, Argonne, IL 60439 USA. Utkal Univ, Dept Phys, Bhubaneswar 751004, Orissa, India. RP Satyam, PV (reprint author), Inst Phys, Sachivalaya Marg, Bhubaneswar 751005, Orissa, India. RI Mohapatra, Satyabrata/E-4882-2011; Goswami, Dipak/E-8186-2011; Satpati, Biswarup/B-5194-2013 OI Mohapatra, Satyabrata/0000-0002-9090-2774; Goswami, Dipak/0000-0002-5891-6172; Satpati, Biswarup/0000-0003-1175-7562 NR 26 TC 14 Z9 14 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6399 EP 6401 DI 10.1063/1.1569026 PN 1 PG 3 WC Physics, Applied SC Physics GA 677CQ UT WOS:000182789700085 ER PT J AU Dobrovitski, VV Katsnelson, MI Harmon, BN AF Dobrovitski, VV Katsnelson, MI Harmon, BN TI Statistical coarse graining as an approach to multiscale problems in magnetism (invited) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID MAGNETIZATION REVERSAL; THIN-FILMS; FINITE-ELEMENT; LENGTH SCALES; SIMULATIONS; MICROMAGNETICS; PROPAGATION; COERCIVITY AB Multiscale phenomena which include several processes occurring simultaneously at different length scales, and exchanging energy with each other, are widespread in magnetism (e.g., nucleation of magnetization reversal at an atomic-scale defect or grain boundary, a domain wall breaking through an atomic-scale defect, etc.). We demonstrate that in such multiscale processes, a role of short-wavelength excitations dynamically generated near the defects is crucial. As a result, standard micromagnetic theory is not always sufficient for description of these phenomena. We present a novel coarse-graining approach to length scales coupling in dynamical magnetic modeling, which allows accurate treatment of microscopic defects in nanomagnets. The results of simulations performed on simplified model systems, where an atomic-scale variation of anisotropy and exchange represent defects in real systems, show that the coarse-graining approach achieves practically the precision of exact atomic simulations, while describing the system with a much smaller number of degrees of freedom. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Inst Met Phys, Ekaterinburg 620219, Russia. RP Dobrovitski, VV (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Katsnelson, Mikhail/D-4359-2012 NR 27 TC 3 Z9 3 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6432 EP 6437 DI 10.1063/1.1556095 PN 2 PG 6 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300005 ER PT J AU Antropov, VP Belashchenko, KD AF Antropov, VP Belashchenko, KD TI Multiscale modeling of hysteretic phenomena in magnets (invited) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID MICROSTRUCTURE; FERROMAGNETS; ALLOYS; WALLS; FE; CO AB Methodology of multiscale modeling of hysteretic phenomena in magnets is discussed. A practical combination of first-principles, micromagnetic, and microstructural calculations is constructed which allows one to study the hysteretic phenomena in hard magnets. Advantages and shortcomings of this approach are discussed. Multiscale nature of coercivity in CoPt type magnets is elucidated. Two sources of coercivity in polytwinned CoPt type magnets developing at different length scales, domain wall pinning at antiphase boundaries and splitting at twin boundaries, are illustrated for a realistic microstructure. (C) 2003 American Institute of Physics. C1 Ames Lab, Ames, IA 50011 USA. RP Antropov, VP (reprint author), Ames Lab, Ames, IA 50011 USA. RI Belashchenko, Kirill/A-9744-2008 OI Belashchenko, Kirill/0000-0002-8518-1490 NR 23 TC 2 Z9 2 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6438 EP 6443 DI 10.1063/1.1556096 PN 2 PG 6 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300006 ER PT J AU Vlasko-Vlasov, VK Welp, U Guo, ZJ Jiang, JS Pearson, JE Liu, JP Miller, DJ Tang, Y Bader, SD AF Vlasko-Vlasov, VK Welp, U Guo, ZJ Jiang, JS Pearson, JE Liu, JP Miller, DJ Tang, Y Bader, SD TI Remagnetization processes in SmCo/NdCo exchange springs SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID ANISOTROPY; FIELD AB Remagnetization processes in a SmCo/NdCo exchange spring system are studied using superconducting quantum interference device magnetometry and magneto-optical imaging. The magneto-optical images reveal that the reversal of the soft NdCo layer and its return to the polarized state at cycling around the exchange bias field occur due to the asymmetric nucleation and growth of twisted-phase domains. The observed peculiarities of the domain-wall kinetics are discussed and a way of tailoring exchange biased systems by regulating the motion of the twisted-phase domains is suggested. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Louisiana Tech Univ, Ruston, LA 71271 USA. RP Vlasko-Vlasov, VK (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 10 TC 3 Z9 4 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6486 EP 6488 DI 10.1063/1.1541634 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300021 ER PT J AU Haskel, D Choi, Y Lee, DR Lang, JC Srajer, G Jiang, JS Bader, SD AF Haskel, D Choi, Y Lee, DR Lang, JC Srajer, G Jiang, JS Bader, SD TI Hard x-ray magnetic circular dichroism study of a surface-driven twisted state in Gd/Fe multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID SPIN-FLOP TRANSITION; PHASE-TRANSITIONS; SUPERLATTICES; GD; REORIENTATION; DIAGRAM; FIELD; FE AB By tuning the incidence angle of hard, circularly polarized x-rays with respect to the sample surface, we are able to independently probe surface and bulk magnetic states in a Fe(35 Angstrom)[Gd(50 Angstrom)/Fe(35 Angstrom)](15) ferrimagnetic multilayer by magnetic circular dichroism (MCD). We show that a twisted magnetic state nucleates at the surface of the multilayer at Tapproximate to0.7 T-comp, where T-comp is the ferrimagnetic compensation temperature. At nucleation, the twist penetrates approximate to170 Angstrom or two bilayers. Despite its theoretical prediction by LePage and Camley more than 15 years ago [J.G. LePage and R. E. Camley, Phys. Rev. Lett. 65, 1152 (1990); R. E. Camley, Phys. Rev. B 35, 3608 (1987)], this surface-twisted state has eluded direct experimental detection up to now. Its clear observation here demonstrates the power of grazing incidence, hard x-ray, MCD measurements for studies of magnetic phase transitions in layered structures. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Haskel, D (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 17 TC 12 Z9 12 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6507 EP 6509 DI 10.1063/1.1543875 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300028 ER PT J AU Lin, KW Gambino, RJ Lewis, LH AF Lin, KW Gambino, RJ Lewis, LH TI Structural and magnetic characterization of ion-beam deposited NiFe/NixFe1-xO composite films SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID EXCHANGE AB Nanocomposite films of Ni80Fe20/NixFe1-xO were prepared by a dual ion-beam deposition technique. The structural and magnetic properties of nanocomposite films fabricated with oxygen content in the deposition assist beam ranging from 0% to 55% were studied. The dependence of the resistivity on oxygen percent shows that the compositions with exchange-enhanced coercivity are close to a percolation threshold. A strong temperature dependence of coercivity H-c and exchange bias field H-ex is found in these composite films. Films prepared with 46% O-2 in the assist beam exhibit an enhanced H-c relative to Permalloy (Ni80Fe20) and a characteristic shifted hysteresis loop indicative of exchange coupling between the constituent metal and oxide phases. At T=10 K, films prepared with 44% O-2 in the assist beam have an exchange shift H(ex)similar to-225 Oe with a blocking temperature T(B)similar to100 K that reflects the low Neel temperatures of FeO-rich NixFe1-xO solid solutions. (C) 2003 American Institute of Physics. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11793 USA. RP Lin, KW (reprint author), Toyota Technol Inst, Informat Storage Mat Lab, Tempaku Ku, 2-12-1 Hisakata, Nagoya, Aichi 4688511, Japan. NR 7 TC 21 Z9 21 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6590 EP 6592 DI 10.1063/1.1543879 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300055 ER PT J AU Brown, G Novotny, MA Rikvold, PA AF Brown, G Novotny, MA Rikvold, PA TI Transition state in magnetization reversal SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FL SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID DYNAMICS; SYSTEMS AB We consider a magnet with uniaxial anisotropy in an external magnetic field along the anisotropy direction, but with a field magnitude smaller than the coercive field. There are three representative magnetization configurations corresponding to three extrema of the free energy. The equilibrium and metastable configurations, which are magnetized approximately parallel and antiparallel to the applied field, respectively, both correspond to local free-energy minima. The third extremum configuration is the saddle point separating these minima. It is also called the transition state for magnetization reversal. The free-energy difference between the metastable and transition-state configurations determines the thermal stability of the magnet. However, it is difficult to determine the location of the transition state in both experiments and numerical simulations. Here it is shown that the computational Projective Dynamics method, applied to the time dependence of the total magnetization, can be used to determine the transition state. From large-scale micromagnetic simulations of a simple model of magnetic nanowires with no crystalline anisotropy, the magnetization associated with the transition state is found to be linearly dependent on temperature, and the free-energy barrier is found to be dominated by the entropic contribution at reasonable temperatures and external fields. The effect of including crystalline anisotropy is also discussed. Finally, the influence of the spin precession on the transition state is determined by comparison of the micromagnetic simulations to kinetic Monte Carlo simulations of precession-free (overdamped) dynamics. (C) 2003 American Institute of Physics. C1 Oak Ridge Natl Lab, Ctr Comp Sci, Oak Ridge, TN 37831 USA. Florida State Univ, CSIT, Dept Phys, Tallahassee, FL 32306 USA. Mississippi State Univ, Dept Phys & Astron, Mississippi State, MS 39762 USA. Mississippi State Univ, Ctr Computat Sci, ERC, Mississippi State, MS 39762 USA. Florida State Univ, MARTECH, Tallahassee, FL 32306 USA. RP Oak Ridge Natl Lab, Ctr Comp Sci, Oak Ridge, TN 37831 USA. EM 6bg@ornl.gov RI Brown, Gregory/F-7274-2016 OI Brown, Gregory/0000-0002-7524-8962 NR 15 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6817 EP 6819 DI 10.1063/1.1543882 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300131 ER PT J AU Samolyuk, GD Antropov, VP AF Samolyuk, GD Antropov, VP TI Magneto-structural phase transition in Gd-5(Si2Ge2) and MnFe(P1/3As2/3) systems SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID ENERGY AB We study the electronic structure and magnetic properties of Gd-5(Si2Ge2) and MnFe(P1/3As2/3) system of alloys using the density functional approach. The stability of their magnetic structures was investigated. The total energy as a function of structural deformation was calculated. The exchange coupling calculations show that the effective Heisenberg model parameters are decreased with structural deformation. The free energy as a function of temperature and deformation was calculated. The decrease of effective exchange coupling leads to first order magneto-structural phase transition, \partial derivativeH/partial derivativeT\ and giant magneto-caloric effect. (C) 2003 American Institute of Physics. C1 ISU, Ames Lab, Ames, IA 50011 USA. RP Samolyuk, GD (reprint author), ISU, Ames Lab, Ames, IA 50011 USA. NR 15 TC 8 Z9 8 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6882 EP 6884 DI 10.1063/1.1556153 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300152 ER PT J AU Gomes, AM Oliveira, IS Guimaraes, AP Lima, AL von Ranke, PJ AF Gomes, AM Oliveira, IS Guimaraes, AP Lima, AL von Ranke, PJ TI Low temperature magnetocaloric properties of HoNi2 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc AB The magnetocaloric properties of the HoNi2 intermetallic compound are presented. Theoretical results predicted that the crystalline electric field is responsible for the second peak in the magnetic entropy change curve at low temperatures in HoNi2 single crystal oriented in the [100] direction. We present the isothermal magnetization and adiabatic heat capacity data obtained on HoNi2 polycrystalline samples. The experimental data were used to calculate the magnetic entropy change after a field variation of 40 kOe. Independently, we extended the theoretical analysis for a polycrystalline sample in order to compare with the experimental results. (C) 2003 American Institute of Physics. C1 Ctr Brasileiro Pesquisas Fis, BR-22290180 Rio De Janeiro, Brazil. Iowa State Univ, Ames Lab, Ames, IA 50010 USA. Univ Estado Rio de Janeiro, IF DEQ, BR-20550013 Rio De Janeiro, Brazil. RP Gomes, AM (reprint author), Ctr Brasileiro Pesquisas Fis, Rua Dr Xavier Sigaud 150 Urca, BR-22290180 Rio De Janeiro, Brazil. RI Oliveira, Ivan/A-4196-2012; Guimaraes, Alberto/A-5546-2010 OI Guimaraes, Alberto/0000-0001-6024-2691 NR 11 TC 5 Z9 5 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 6939 EP 6941 DI 10.1063/1.1558251 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300171 ER PT J AU Lee, HK Schulthess, TC Brown, G Landau, DP Sorge, KD Thompson, JR AF Lee, HK Schulthess, TC Brown, G Landau, DP Sorge, KD Thompson, JR TI Magnetic properties of Fe nanocubes with magnetostatic interactions SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID SIMULATION AB Recent experiments indicate that the magnetic properties of single domain Fe nanoparticles (dispersed in an insulating matrix) may be dominated by magnetostatic interactions at packing fractions as low as 10%, where the separation between particles is of the same order as the particle size [Sorge , IEEE Trans. Magn. 37, 2197 (2001)]. We use extensive Monte Carlo simulations to calculate the temperature dependence of the remnant magnetization as a direct test of this hypothesis [Sorge , IEEE Trans. Magn. 37, 2197 (2001)]. The particle distribution is constructed with a computer model that imitates the experimental system for which data were obtained from transmission electron microscopy images, and the Fe particles are modeled as point dipoles with cubic anisotropy. Using bulk values for the anisotropy and the Fe magnetization, our simulations reproduce very well the experimental remnant magnetization. Furthermore, we find that the magnetic properties are dominated by the effects of dipole-dipole interactions and that the experimental results cannot be reproduced with noninteracting particles. (C) 2003 American Institute of Physics. C1 Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. Univ Georgia, Ctr Simulat Phys, Athens, GA 30605 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Florida State Univ, CSIT, Tallahassee, FL 32306 USA. RP Lee, HK (reprint author), Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. RI Brown, Gregory/F-7274-2016 OI Brown, Gregory/0000-0002-7524-8962 NR 8 TC 10 Z9 10 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7047 EP 7049 DI 10.1063/1.1557396 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300207 ER PT J AU Welp, U Vlasko-Vlasov, VK Crabtree, GW Hiller, J Zaluzec, N Metlushko, V Ilic, B AF Welp, U Vlasko-Vlasov, VK Crabtree, GW Hiller, J Zaluzec, N Metlushko, V Ilic, B TI Magnetization reversal in arrays of individual and coupled Co-rings SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID DOT ARRAYS; MAGNETS AB The magnetization behavior of arrays on 10 mum Co rings has been studied using magnetometry, magneto-optical imaging, and Lorentz microscopy. Square arrays of individual rings and arrays of chains of interacting, touching rings have been investigated. In fields transverse to the chains the switching of the rings occurs always in pairs. This coupling introduces a broad distribution of switching fields and correspondingly a broad magnetization loop. Lorentz microscopy reveals that the switching for both, the isolated and the coupled rings, occurs through the formation of a buckled state, and the nucleation and propagation of a vortex domain wall. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA. Cornell Univ, Sch Appl & Engn Phys, Cornell Nanofabricat Facil, Ithaca, NY 14853 USA. RP Welp, U (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Hiller, Jon/A-2513-2009; Ilic, Rob/N-1359-2014 OI Hiller, Jon/0000-0001-7207-8008; NR 11 TC 22 Z9 22 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7056 EP 7058 DI 10.1063/1.1557393 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300210 ER PT J AU Boukhvalov, DW Dobrovitski, VV Katsnelson, MI Lichtenstein, AI Harmon, BN Kogerler, P AF Boukhvalov, DW Dobrovitski, VV Katsnelson, MI Lichtenstein, AI Harmon, BN Kogerler, P TI Electronic structure and exchange interactions in V-15 magnetic molecules: LDA+U results SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FL SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID SPIN SYSTEM; CLUSTERS AB Single-molecule magnets V-15 (K-6[V15As6O42(H2O)].8H(2)O) have attracted a great deal of attention recently. These magnets are promising systems for studying such fundamental problems as spin tunneling, spin coherence, and low-temperature spin relaxation. To understand in detail the internal magnetic and electronic structure, and the intramolecular interactions responsible for the formation and low-energy excitations in V-15 molecules, we have performed electronic structure calculations using the local spin density approximation with on-site repulsion paramter U (so-called LSDA+U) approach. The calculated values of magnetic moments and charge states of vanadium ions agree well with experiments confirming the V4+ state of vanadium ions. We found that for Usimilar to4-5 eV, good description of known properties of V-15 molecule can be achieved. Comparing the results of the band-structure calculations with the experiments, we have found that the LDA+U description of the V-15 magnet is in agreement with experimental data. (C) 2003 American Institute of Physics. C1 Forschungszentrum Julich, D-52425 Julich, Germany. Russian Acad Sci, Inst Met Phys, Ural Div, Ekaterinburg 620219, Russia. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Uppsala Univ, Dept Phys, SE-75121 Uppsala, Sweden. Univ Nijmegen, NL-6525 ED Nijmegen, Netherlands. RP Forschungszentrum Julich, Postfach 1913, D-52425 Julich, Germany. EM slava@ameslab.gov RI Katsnelson, Mikhail/D-4359-2012; Kogerler, Paul/H-5866-2013; Lichtenstein, Alexander/K-8730-2012 OI Kogerler, Paul/0000-0001-7831-3953; Lichtenstein, Alexander/0000-0003-0152-7122 NR 19 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7080 EP 7082 DI 10.1063/1.1540035 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300218 ER PT J AU Luban, M Kogerler, P Miller, LL Winpenny, REP AF Luban, M Kogerler, P Miller, LL Winpenny, REP TI Heisenberg model of a {Cr-8}-cubane magnetic molecule SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID CLUSTERS AB A Heisenberg model of eight Cr-III paramagnetic centers (spins s=3/2) at the vertices of a cube with four distinct exchange interactions is found to provide a reasonably accurate description of the magnetic susceptibility of the cubane-type magnetic molecule [Cr8O4(O2CC6H5)(16)]={Cr-8} from 2-290 K for an external field of 0.5 T. We find that two exchange bonds are antiferromagnetic (13, 24 K) and two are ferromagnetic (5, 13.5 K), with an accuracy of approximately 1 K. The determination of the four exchange constants is greatly facilitated using the exact high-temperature expansion of the weak-field susceptibility, effectively reducing the number of unknown parameters to two. We have calculated the thermodynamic properties of the system and these can be compared with the results of future experiments. At temperatures below 0.5 K sharp increases are expected in the magnetization versus external magnetic field at approximately 6 and 12 T and higher fields due to level crossings. Inelastic neutron scattering could check our predictions for the low-lying magnetic energy levels. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England. RP Luban, M (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Kogerler, Paul/H-5866-2013 OI Kogerler, Paul/0000-0001-7831-3953 NR 9 TC 6 Z9 6 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7083 EP 7085 DI 10.1063/1.1558231 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300219 ER PT J AU Suh, BJ Procissi, D Jung, JK Bud'ko, S Jeon, WS Kim, YJ Jung, DY AF Suh, BJ Procissi, D Jung, JK Bud'ko, S Jeon, WS Kim, YJ Jung, DY TI Magnetic properties and spin dynamics in magnetic molecule {Mn3} SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID H-1-NMR; RINGS AB We report dc magnetization and nuclear magnetic resonance (NMR) measurements in a trinuclear manganese compound, {Mn3}, with formula [Mn3O(O2CCH3)(6)(C5H5N)(3)].C5H5N. The magnetic properties are characterized by two antiferromagnetic (AF) coupling constants, J=-7.9 K and J'=-7.6 K. H-1 NMR linewidth strongly depends on both the magnetic field and temperature, and is quantitatively explained by the dipolar interaction between proton nuclei and Mn ion spins. The strong enhancement of T-1(-1) at low temperatures is ascribed to the slowing down of magnetic fluctuations resulting from building up of AF correlations. From the T dependence of T-1(-1) at low T, we obtained the gap Delta(NMR)=19 K, in qualitative agreement with the gap Deltacongruent to12 K obtained from susceptibility chi. (C) 2003 American Institute of Physics. C1 Catholic Univ Korea, Dept Phys, Puchon 420743, South Korea. Iowa State Univ, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. Sungkyunkwan Univ, Dept Chem, Suwon 440746, South Korea. RP Suh, BJ (reprint author), Catholic Univ Korea, Dept Phys, Puchon 420743, South Korea. EM bjsuh@catholic.ac.kr NR 8 TC 3 Z9 3 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7098 EP 7100 DI 10.1063/1.1555875 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300224 ER PT J AU Kogerler, P Muller, A AF Kogerler, P Muller, A TI Ferromagnetic Cu-II-Cu-II exchange interactions in a polyoxomolybdate-based nanocluster SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID CLUSTERS; CENTERS AB We present initial magnetic properties and a simple Heisenberg model for a recently isolated new member of the {Mo57M6}-type family, a nanometer-sized polyoxomolybdate cluster anion comprising a triangular Cu-6(II) prism. The exchange interactions between the six s=1/2 spin centers are weak compared to the exchange found for other members of the {Mo57M6} cluster family with M=Fe-II, Fe-III, and V-IV but display ferromagnetic exchange interactions of Cu-II-O-Mo-VI-O-Cu-II pairs, i.e., within two equilateral Cu-3(II) triangles. The exchange interaction between the two triangles is antiferromagnetic. The observed temperature dependence of chiT is described well by a Heisenberg model that employs a ferromagnetic intratriangle exchange constant J(1)=1.9 K and antiferromagnetic intertriangle coupling of J(2)=-1.4 K that eventually results in an S=0 ground state. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. Univ Bielefeld, Fak Chem, D-33501 Bielefeld, Germany. RP Kogerler, P (reprint author), Iowa State Univ, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. RI Kogerler, Paul/H-5866-2013; OI Kogerler, Paul/0000-0001-7831-3953; Muller, Achim/0000-0003-0117-4021 NR 5 TC 10 Z9 10 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7101 EP 7102 DI 10.1063/1.1555892 PN 2 PG 2 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300225 ER PT J AU Fishman, RS Jarrell, M AF Fishman, RS Jarrell, M TI Electronic susceptibility and Curie temperature of the double-exchange model within dynamical mean-field theory SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID TRANSITION-TEMPERATURE; INFINITE DIMENSIONS; MAGNETORESISTANCE AB Due to its applications to the manganites, the double-exchange (DE) model has been intensively studied over the past ten years. An especially promising approach to investigate the DE model is dynamical mean-field theory (DMFT), which becomes exact in infinite dimension but accurately describes local quantum fluctuations in three dimensions. In this article, we use DMFT to solve the Bethe-Salpeter equation for the electronic susceptibility above T-C. Assuming a semicircular density-of-states, we obtain an analytic relation for T-C in the limit of large Hund's coupling from the condition that the inverse electronic susceptibility vanishes. Our expression for T-C agrees with an earlier result based on the local-moment susceptibility and corrects a mistake in a result based on the self-consistent equation for the magnetization below T-C. (C) 2003 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. RP Fishman, RS (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Fishman, Randy/C-8639-2013 NR 9 TC 10 Z9 10 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7148 EP 7150 DI 10.1063/1.1556201 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300241 ER PT J AU Crew, DC Kim, J Barmak, K Lewis, LH AF Crew, DC Kim, J Barmak, K Lewis, LH TI Robust exchange coupling in bilayer exchange-spring thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FL SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc AB Exchange coupling across the interface in polycrystalline exchange-spring thin films of L1(0) CoPt and hcp Co has been investigated with magnetic measurements and micromagnetic modeling. For thick enough Co films, the reversal in the second quadrant of the hysteresis loop is multiphase, with full reversal of the soft Co phase accomplished before reversal of the hard CoPt phase. Therefore the exchange field acting on the soft phase is determined as the field of maximum susceptibility in the soft-phase reversal portion of the second quadrant. Experimentally, it is found that the exchange field is a linear function of the inverse thickness of the soft phase. This result is in agreement with the exchange field calculated from the associated micromagnetic modeling only under the condition that the magnitude of the exchange coupling constant between spins across the CoPt-Co interface is similar to that characterizing the bulk CoPt. Experimental and modeling-derived results do not agree for decreased interfacial exchange coupling. This result is surprising, because it was expected that the condition of the interface between the exchange-coupled film layers would have a dominant effect on the magnetic reversal of the system; the presence of expected atomic disorder or chemical impurity at the interface should severely degrade the exchange coupling. (C) 2003 American Institute of Physics. C1 Univ Western Australia, Sch Phys, Crawley 6009, Australia. 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 Univ Western Australia, Sch Phys, Crawley 6009, Australia. EM dcrew@physics.uwa.edu.au RI Barmak, Katayun/A-9804-2008 OI Barmak, Katayun/0000-0003-0070-158X NR 10 TC 8 Z9 8 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7235 EP 7237 DI 10.1063/1.1557313 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300270 ER PT J AU Stewart, DA van Schilfgaarde, M AF Stewart, DA van Schilfgaarde, M TI Digitally doped magnetic resonant tunneling devices: High tunneling magnetoresistance systems SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID TRANSPORT; HETEROSTRUCTURES; SUPERLATTICES; (GA,MN)AS AB Magnetic resonant tunneling devices (RTDs) have been recognized as one possible route to developing a near ideal spin valve. With the advent of dilute magnetic semiconductors, the ability to grow these devices using traditional semiconductor techniques provides a distinct advantage over present metal-based giant magnetoresistance devices. We examine the effect of replacing dilute magnetic semiconductor leads (GaMnAs) with Ga0.5Mn0.5As monolayers adjacent to the RTD structure. We examine transmission through a series of GaAs/AlAs RTDs using principal layer Green function technique in the linear muffin-tin orbital framework. Self-consistent calculations using a linear response technique are done for both nonmagnetic RTDs and ones with Mn doped layers outside the AlAs barriers. The Mn dopant layers lead to splitting of the transmission peaks in both the conduction and the valence bands. The transmission peaks shift as the quantum well width increases in accordance with quantum well states. In addition, transmission in the minority spin channel is suppressed as valence quantum well states move closer to the Fermi energy. Preliminary zero bias conductance calculations give tunneling magnetoresistance values in excess of 1000%. While this estimate does not include spin scattering sources such as spin-orbit coupling, the actual tunneling magnetoresistance should still be very high. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Stewart, DA (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. RI Stewart, Derek/B-6115-2008; OI Stewart, Derek/0000-0001-7355-2605 NR 16 TC 3 Z9 3 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7355 EP 7357 DI 10.1063/1.1556934 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300308 ER PT J AU Mitchell, JF Burley, J Short, S AF Mitchell, JF Burley, J Short, S TI Crystal and magnetic structure of NdBaCo2O5+delta: Spin states in a perovskite-derived, mixed-valent cobaltite SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID METAL-INSULATOR-TRANSITION; LACOO3 AB We report results of neutron powder diffraction studies on the crystallographic and magnetic structures of the compounds NdBaCo2O5+delta (delta=0.0, 0.5). Long-range antiferromagnetic order is found for the delta=0.0 compound, but no evidence of long-range charge-ordering is observed. The delta=0.5 compound shows poor long-range magnetic order, and the absence of such magnetic order is speculated to result from the particular ordered defect crystal structure of this material. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Mitchell, JF (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 22 Z9 22 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 MAY 15 PY 2003 VL 93 IS 10 BP 7364 EP 7366 DI 10.1063/1.1543897 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300311 ER PT J AU Demczyk, BG Zhou, JN Choe, G Stach, E Nelson, EC Dahmen, U AF Demczyk, BG Zhou, JN Choe, G Stach, E Nelson, EC Dahmen, U TI Origin of the orientation ratio in sputtered longitudinal media SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FL SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID THIN-FILM MEDIA; MAGNETIC RECORDING MEDIA; X-RAY-DIFFRACTION; CRYSTALLOGRAPHIC TEXTURE; INPLANE ANISOTROPY; STRESS; DISKS AB The surface morphology, thin film microstructure, and crystallography of sputtered longitudinal media were examined by atomic force and transmission electron microscopy. It was found that surface features along the texture lines in addition to the line density affect the measured orientation ratio. In addition, c-axis alignment along the texture line direction was established. These results point to magnetocrystalline anisotropy associated with the c axis as a major contributor to a high orientation ratio in these materials. (C) 2003 American Institute of Physics. C1 MMC Technol, San Jose, CA 95131 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP MMC Technol, 2001 Fortune Dr, San Jose, CA 95131 USA. RI Stach, Eric/D-8545-2011 OI Stach, Eric/0000-0002-3366-2153 NR 22 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7393 EP 7395 DI 10.1063/1.1558236 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300321 ER PT J AU He, W Lee, SJ Jiles, DC Schmidt, DH Porter, MD Shinar, R AF He, W Lee, SJ Jiles, DC Schmidt, DH Porter, MD Shinar, R TI Design of high-magnetic field gradient sources for controlling magnetically induced flow of ferrofluids in microfluidic systems SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 47th Annual Conference on Magnetism and Magnetic Materials CY NOV 11-15, 2002 CL TAMPA, FLORIDA SP Amer Inst Phys, IEEE Magnet Soc, Amer Ceram Soc, US Off Naval Res, Amer Phys Soc, Amer Soc Testing & Mat, Minerals, Met & Mat Soc ID MICROPUMP AB The use of miniature electromagnets for ferrofluid-actuated liquid dispensing into microfluidic channels has been investigated by numerical simulations using the finite element method and measurements of fluid displacement and flow rate. The simulations illustrate the effect of structural and geometrical parameters of single and paired solenoid coils on the magnetic force experienced by the ferrofluid. Dual solenoids were used for extended fluid displacement. Ferrofluid positioning and flow rates were controlled also by using a solenoid with an iron core. The experimental measurements of fluid flow in capillaries were used to validate the modeling calculations. The results can be used as a basis for the development of on-chip ferrofluid-based devices integrated with microfluidic architectures. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Microelect Res Ctr, Ames, IA 50011 USA. Iowa State Univ, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. RP He, W (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 10 TC 5 Z9 5 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7459 EP 7461 DI 10.1063/1.1557361 PN 2 PG 3 WC Physics, Applied SC Physics GA 677RX UT WOS:000182822300343 ER PT J AU Lee, HK Landau, DP Schulthess, TC AF Lee, HK Landau, DP Schulthess, TC TI Monte Carlo simulations of phase transitions in Rb2MnF4 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID 2-DIMENSIONAL ANTIFERROMAGNETS; SPIN FLUCTUATIONS; DYNAMICS AB Rb2MnF4 is believed to consist of very weakly coupled magnetic layers with isotropic superexchange between nearest neighbor Mn2+ ions in the same plane. To test this conjecture, Monte Carlo simulations were performed on a theoretical model consisting of stacked, nearest neighbor Heisenberg square lattices coupled by dipolar interactions. Simulation parameters such as the lattice constants and the superexchange constant were taken from experimental measurements, and periodic boundary conditions were used in all directions. We succeeded in achieving an algorithmic speed up from O(N-2) to O(N ln N) through the combination of fast Fourier transforms for the evaluation of the dipolar interactions and global updates in the Monte Carlo steps. Our simulations reproduced very well the behavior observed in experiments with Rb2MnF4 crystals. (C) 2003 American Institute of Physics. C1 Univ Georgia, Ctr Simulat Phys, Athens, GA 30605 USA. Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Lee, HK (reprint author), Univ Georgia, Ctr Simulat Phys, Athens, GA 30605 USA. NR 14 TC 1 Z9 1 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7643 EP 7645 DI 10.1063/1.1541644 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600003 ER PT J AU Gu, JY You, CY Jiang, JS Bader, SD AF Gu, JY You, CY Jiang, JS Bader, SD TI Magnetization-orientation dependence of the superconducting transition temperature and magnetoresistance in the ferromagnet-superconductor-ferromagnet trilayer system SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MULTILAYERS AB The superconducting transition temperature (T-c) of a ferromagnet-superconductor-ferromagnet film system is predicted to exhibit a dependence of the magnetization orientation of the ferromagnetic layers. We have grown CuNi/Nb/CuNi films via magnetron sputtering and verified experimentally that the T-c is slightly higher in the case that the mutual magnetization direction of the two CuNi layers is antiparallel (AP) compared to the parallel (P). We also find that an similar to25% resistance change occurs near T-c in CuNi(5 nm)/Nb(18 nm)/CuNi(5 nm) when the two CuNi layers change their magnetization directions from P to AP. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Gu, JY (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI You, Chun-Yeol/B-1734-2010; Bader, Samuel/A-2995-2013 OI You, Chun-Yeol/0000-0001-9549-8611; NR 13 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7696 EP 7698 DI 10.1063/1.1540150 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600021 ER PT J AU Charlton, T Lederman, D AF Charlton, T Lederman, D TI Surface spin-flop transition in epitaxial Co/Re superlattices SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ANISOTROPY AB Two hcp [Co/Re](x) superlattices were grown simultaneously on (11 (2) over bar0) Al2O3 single crystal substrates, where the number of bilayers x=20 and 21. The film growth was epitaxial in nature with the [0001] of the substrate aligned with the [0001] of the superlattice. The film interface roughness and thickness were determined by x-ray reflectivity to be sigma=4.4 Angstrom, t(Re)=8 Angstrom, t(Co)=20 Angstrom for x=20 and t(Co)=16 Angstrom for x=21. The Co layers were antiferromagnetically coupled with an easy axis along the [0001]. As expected, the 20-bilayer superlattice exhibited both surface and bulk spin-flop transitions, while in the 21-bilayer superlattice only the bulk spin-flop transition was observed by magneto-optic Kerr effect measurements. The magnetoresistance (MR) with Hparallel to[0001] shows an extended plateau around H=0 with Hperpendicular toI, where H is the applied magnetic field and I the sensing current. The layer-by-layer magnetization profile was found using energy minimization techniques and the MR was calculated using an empirical model. The calculations compare favorably with the MR data allowing the separation of anisotropic magnetoresistance and giant magnetoresistance components to the MR. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Charlton, T (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 0 Z9 0 U1 2 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7705 EP 7707 DI 10.1063/1.1557957 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600024 ER PT J AU Welp, U te Velthuis, SGE Felcher, GP Gredig, T Dahlberg, ED AF Welp, U te Velthuis, SGE Felcher, GP Gredig, T Dahlberg, ED TI Domain formation in exchange biased Co/CoO bilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIZATION REVERSAL; ASYMMETRY AB The magnetic behavior of exchange biased Co/CoO polycrystalline thin films has been investigated using magnetometry and magneto-optical (MO) imaging. For CoO layer thicknesses of about 30 Angstrom, these films exhibit a strong training effect below the blocking temperature of 130 K. A sharp initial reversal of the magnetization of the FM Co layer after field-cooling is followed by S-shaped magnetization loops with reduced coercive fields. The MO images show that during the initial magnetization reversal the remagnetization front moves from the edge of the sample into the homogenously magnetized film, leaving behind an irregular pattern of domains of the order of 10 mum. These domains, once generated during the first reversal, do not expand or move on subsequent magnetization loops and can be erased only by heating above the blocking temperature. This suggests that the domains are related to domains in the antiferromagnetic CoO layer. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM tevelthuis@anl.gov RI Gredig, Thomas/C-3776-2008; te Velthuis, Suzanne/I-6735-2013; OI te Velthuis, Suzanne/0000-0002-1023-8384; Gredig, Thomas/0000-0002-5824-7626 NR 11 TC 32 Z9 33 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7726 EP 7728 DI 10.1063/1.1540152 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600031 ER PT J AU Procissi, D Suh, BJ Jung, JK Kogerler, P Vincent, R Borsa, F AF Procissi, D Suh, BJ Jung, JK Kogerler, P Vincent, R Borsa, F TI Unconventional Heisenberg spin triangle in magnetic molecule {V15}: A proton nuclear magnetic resonance study SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID IONS AB We present results of H-1 nuclear magnetic resonance (NMR) and relaxation in polyoxovanadate cluster {V15} with formula K-6[V15As6O42].9(H2O). The data in {V15} are compared with the published data in {V6} with the formula [CN3H6](4)Na-2[H-4{V3L}(2)P4O4].14H(2)O, which contains two independent spin triangles. Temperature T and field H dependence of the NMR linewidth are well explained by the magnetic dipolar interaction between the proton nuclei and vanadium ion spins in both compounds. T and H dependence of proton relaxation rate T-1(-1) show great differences in the two compounds. The difference indicates a completely different spin dynamics for the two Heisenberg spin-triangle systems whereby in {V15} the fluctuations of the V-IV (s=1/2) in the central triangle are dominated by the interlayer coupling with the V-IV spins in the two upper and lower hexagons. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. Catholic Univ Korea, Dept Phys, Puchon 420743, South Korea. Dipartimento Fis A Volta, I-27100 Pavia, Italy. Unita INFM Pavia, I-27100 Pavia, Italy. RP Procissi, D (reprint author), Iowa State Univ, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. RI Kogerler, Paul/H-5866-2013 OI Kogerler, Paul/0000-0001-7831-3953 NR 8 TC 10 Z9 11 U1 2 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7810 EP 7812 DI 10.1063/1.1540051 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600059 ER PT J AU Furukawa, Y Aizawa, K Kumagai, K Ullu, R Lascialfari, A Borsa, F AF Furukawa, Y Aizawa, K Kumagai, K Ullu, R Lascialfari, A Borsa, F TI Tunneling splitting of magnetic levels in Fe8 detected by H-1 NMR cross relaxation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FE-8 MOLECULAR NANOMAGNETS; QUANTUM COHERENCE; GROUND-STATE; CLUSTERS AB Measurements of proton NMR and the spin lattice relaxation rate 1/T-1 in the octanuclear iron (III) cluster [Fe-8(N3C6H15)(6)O-2(OH)(12)].[Br-8.9H(2)O], in short Fe8, have been performed at 1.5 K in a powder sample aligned along the main anisotropy z axis, as a function of a transverse magnetic field (i.e., perpendicular to the main easy axis z). A big enhancement of 1/T-1 is observed over a wide range of fields (2.5-5 T), which can be attributed to the tunneling dynamics; in fact, when the tunneling splitting of the pairwise degenerate m= +/-10 states of the Fe8 molecule becomes equal to the proton Larmor frequency a very effective spin lattice relaxation channel for the nuclei is opened. The experimental results are explained satisfactorily by considering the distribution of tunneling splitting resulting from the distribution of the angles in the hard xy plane for the aligned powder, and the results of the direct diagonalization of the model Hamiltonian. (C) 2003 American Institute of Physics. C1 Hokkaido Univ, Grad Sch Sci, Div Phys, Sapporo, Hokkaido 0600810, Japan. Dipartimento Fis A Volta, I-27100 Pavia, Italy. Unita INFM Pavia, I-27100 Pavia, Italy. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Ames Lab, Ames, IA 50011 USA. RP Furukawa, Y (reprint author), Hokkaido Univ, Grad Sch Sci, Div Phys, Sapporo, Hokkaido 0600810, Japan. NR 17 TC 4 Z9 4 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7813 EP 7815 DI 10.1063/1.1540052 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600060 ER PT J AU Butler, WH Bandyopadhyay, A Srinivasan, R AF Butler, WH Bandyopadhyay, A Srinivasan, R TI Electronic and magnetic structure of a 1000 K magnetic semiconductor: alpha-hematite (Ti) SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; FERROMAGNETISM; METALS; MODEL; FILMS AB There has been much interest in doping traditional semiconductors such as GaAs with Mn or other transition metals in order to obtain semiconductors that are magnetic at room temperature. Some of the goals of this research have been a Curie temperature that exceeds 400 K and the possibility of both n- and p-type doping. An alternative approach is to investigate nontraditional semiconducting materials that are known to be magnetic at room temperature. An example of such a material is solid solutions of the minerals ilmenite (FeTiO3) and alpha-hematite (Fe2O3). In this article we investigate the electronic and magnetic structure of Ti doped alpha-hematite using density functional theory and find within this model: alpha-hematite is an antiferromagnetic insulator with strong ferromagnetic coupling in the cation planes perpendicular to the c axis and antiferromagnetic coupling between these planes. Substitution of Ti for Fe produces a net moment of 4mu(B) and a negative carrier in one spin channel. The negative carrier resides largely on the second nearest neighbor cation sites. The Ti atoms prefer not to sit on adjacent cation planes. Doping alpha-hematite with Ti atoms on alternate cation layers should lead to a ferrimagnetic semiconductor with a magnetic transition temperature of nearly 1000 K. (C) 2003 American Institute of Physics. C1 Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. Univ Alabama, Dept Phys, Tuscaloosa, AL 35487 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Alabama, Dept Elect & Comp Engn, Tuscaloosa, AL 35487 USA. Univ Alabama, Dept Aerosp Engn, Tuscaloosa, AL 35487 USA. RP Butler, WH (reprint author), Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. NR 22 TC 48 Z9 48 U1 3 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7882 EP 7884 DI 10.1063/1.1556127 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600083 ER PT J AU Vavassori, P Grimsditch, M Novosad, V Metlushko, V Ilic, B AF Vavassori, P Grimsditch, M Novosad, V Metlushko, V Ilic, B TI Magnetization switching in Permalloy square ring magnets SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GRATINGS; DOTS AB We present the results of a study of magnetization switching in Permalloy square rings using the diffraction magneto-optic Kerr effect combined with numerical micromagnetic simulations. Diffracted loops show a two-step switching process as the external field is swept along both the ring edge and the diagonal. The hysteresis loops calculated from micromagnetic simulations show that switching should occur via a single step transition from a one onion to the reversed onion state for both directions of field applied. We have found that in order to reproduce the observed two-step reversal slight asymmetry has to be introduced into the ring shape. In this case a stable intermediate states appear during switching, accounting for the shape of diffracted loops. (C) 2003 American Institute of Physics. C1 Univ Ferrara, INFM, Res Ctr Nanostruct & Biosyst Surfaces S3, Dipartimento Fis, I-44100 Ferrara, Italy. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA. Cornell Univ, Sch Appl & Engn Phys, Cornell Nanofabricat Facil, Ithaca, NY 14853 USA. RP Vavassori, P (reprint author), Univ Ferrara, INFM, Res Ctr Nanostruct & Biosyst Surfaces S3, Dipartimento Fis, I-44100 Ferrara, Italy. RI Novosad, Valentyn/C-2018-2014; Ilic, Rob/N-1359-2014; Vavassori, Paolo/B-4299-2014; Novosad, V /J-4843-2015 OI Vavassori, Paolo/0000-0002-4735-6640; NR 11 TC 10 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7900 EP 7902 DI 10.1063/1.1557760 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600088 ER PT J AU Castano, FJ Hao, Y Haratani, S Ross, CA Vogeli, B Smith, HI Sanchez-Hanke, C Kao, CC Zhu, X Grutter, P AF Castano, FJ Hao, Y Haratani, S Ross, CA Vogeli, B Smith, HI Sanchez-Hanke, C Kao, CC Zhu, X Grutter, P TI Magnetic force microscopy and x-ray scattering study of 70x550 nm(2) pseudo-spin-valve nanomagnets SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RANDOM-ACCESS MEMORY; GIANT MAGNETORESISTANCE; REVERSAL; ARRAYS AB The room-temperature magnetic properties of large area arrays of 70x550 nm(2) nanoelements made from a NiFe 6 nm/ Cu 3 nm/ Co 4 nm multilayer stack have been investigated using magnetic force microscopy (MFM), alternating gradient magnetometry (AGM), and scattering experiments using synchrotron radiation. MFM measurements on individual elements show square major and minor loops, while the collective magnetization reversal, measured from both AGM and elementally specific hysteresis loops obtained from synchrotron scattering experiments, show a wide distribution of switching fields and interaction fields, due to the variability between the elements. (C) 2003 American Institute of Physics. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11073 USA. McGill Univ, Dept Phys, Ctr Phys Mat, Montreal, PQ H3A 2T8, Canada. RP Ross, CA (reprint author), MIT, Dept Mat Sci & Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Hao, Yaowu/E-6851-2010 NR 14 TC 4 Z9 4 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 MAY 15 PY 2003 VL 93 IS 10 BP 7927 EP 7929 DI 10.1063/1.1558076 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600097 ER PT J AU Meacham, BE Branagan, DJ AF Meacham, BE Branagan, DJ TI Developing highly coercive microstructures in Pr-Co magnets by Gd substitution SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPIN-REORIENTATION PHENOMENON; PRCO5 AB While permanent magnets based on Sm1Co5 are technologically important, magnets made from isostructural Pr1Co5 are not commercially significant even though Pr1Co5 has better intrinsic magnetic properties. The biggest problem is the formation of unfavorable phase equilibria which leads to an inability to develop high coercivity in binary Pr-Co alloys. A proposed solution was to make a hyperstoichiometric alloy with Gd as a substitute, in addition to carbon, to inhibit the formation of the deleterious phases leading to a predominantly single magnetic phase composition. An enhancement was observed in the coercivity. This result is perhaps surprising considering that the Gd atom, with a spherical 4f electron shell, is not expected to contribute to the magnetocrystalline anisotropy. Thus, the expectation was that the coercivity increase was caused by the microstructure but no distinguishing feature of microstructure was observed in transmission electron microscopy. It appears that Gd substitution instead affects the intrinsic magnetocrystalline anisotropy by reducing the effect of the small canting of the Pr moment through dilution. (C) 2003 American Institute of Physics. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Meacham, BE (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 6 TC 7 Z9 7 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 MAY 15 PY 2003 VL 93 IS 10 BP 7963 EP 7965 DI 10.1063/1.1541656 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600108 ER PT J AU Branagan, DJ Meacham, BE McCallum, RW Dennis, KW Kramer, MJ AF Branagan, DJ Meacham, BE McCallum, RW Dennis, KW Kramer, MJ TI High hysteresis in a homogeneous metallic glass SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ALLOYS; MAGNETIZATION; COERCIVITY AB In this article, we demonstrate high hysteresis in a well characterized homogeneous Tb-Al glass which contained no crystallites or crystalline embryos as verified using conventional and synchrotron diffraction, neutron diffraction, and direct observation in the transmission electron microscope. At low temperature (2 K), the metallic glass structure exhibited intrinsic coercivities approaching 23 kOe and high isotropic energy products of 12.4 MGOe. After crystallization into a three-phase nanoscale structure, the hard magnetic properties were found to be far inferior to that obtainable in the glass structure. From the well defined intrinsic magnetic properties (M-sat,T-c), it is clear that the glass contains one or more types of well defined associations (i.e., clusters) and that these associations lead to ferromagnetic coupling/ordering. From the large random magnetic anisotropy, it is probable that the domain size is much larger than the structural cluster size. The measured single-phase loop shapes and the development of high coercivity in the glass state can be explained by an "exchange bias" mechanism resulting in a near perfect distribution of "fragile" pinning centers. (C) 2003 American Institute of Physics. C1 Bechtel BWXT Idaho LLC, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83401 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Branagan, DJ (reprint author), Bechtel BWXT Idaho LLC, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83401 USA. NR 8 TC 2 Z9 2 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7969 EP 7971 DI 10.1063/1.1538178 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600110 ER PT J AU Yang, N Dennis, KW McCallum, RW Kramer, MJ Zhang, YG Lee, PL AF Yang, N Dennis, KW McCallum, RW Kramer, MJ Zhang, YG Lee, PL TI Role of the Fe sublattice on the Invar anomaly in R2Fe14B compounds SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPONTANEOUS MAGNETOSTRICTION AB Thermal expansion anomalies of Nd2Fe14B and Y2Fe14B stoichiometric compounds have been studied by x-ray diffraction with high energy synchrotron radiation using a Debye-Scherrer geometry from room temperature to 1000 K. Y2Fe14B and Nd2Fe14B have similar temperature dependence of lattice parameters and bond distances up to their Curie temperatures T-c. The volumetric spontaneous magnetostriction at room temperature for Nd2Fe14B and Y2Fe14B were determined to be 1.49% and 1.45%, respectively. Among the Fe-Fe bonds, those bonds containing Fe(j2), whose projections are dominantly in the basal plane, have the highest contribution to the Invar effect. These bonds have magnetostrictive strain ranging from 0.4% to 0.8% at room temperature. Above the Curie temperature, Y2Fe14B has an isotropic thermal expansion, while Nd2Fe14B exhibits slightly anisotropic thermal expansion. The iron sublattices dominate the spontaneous volumetric magnetostriction of Y2Fe14B and Nd2Fe14B compounds. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Ames, IA 50010 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50010 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kramer, MJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50010 USA. NR 11 TC 1 Z9 2 U1 4 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7990 EP 7992 DI 10.1063/1.1541647 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600117 ER PT J AU Xu, YW Yang, N Dennis, KW McCallum, RW Kramer, MJ Zhang, YG Lee, PL AF Xu, YW Yang, N Dennis, KW McCallum, RW Kramer, MJ Zhang, YG Lee, PL TI Processing induced changes in Curie temperature of Nd2Fe14B melt-spun ribbons SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PRESSURE AB Changes of the Curie temperature T-c in Nd2Fe14B (2-14-1) can arise from changes in crystal chemistry or can be induced by compressive stresses. We have recently observed decreases in the T-c up to 30 K in nanocomposite melt-spun ribbons of 2-14-1 and alpha-Fe. The starting materials contain about 6.5%-15% additional Fe, while some samples had 3 wt % Ti-C added to control grain growth. Spin reorientation temperatures T-s measured on the samples with or without Ti-C are from 120 to 122 K depending on the wheel speed and composition, suggesting that changes in T-c are due to microstructure. X-ray diffraction dilatometry using the alpha-Fe lattice suggests that at 300 K the iron is under tension but switches sign due to differences in coefficients of thermal expansion between the alpha-Fe and 2-14-1. Similar d spacing of the (110) of alpha-Fe and (006) of 2-14-1 suggest that changes in T-c may in part be due to epitaxial stresses affecting the exchange coupling in the nanocomposite alloys. (C) 2003 American Institute of Physics. C1 Ames Lab, Ames, IA 50011 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Xu, YW (reprint author), Minnesota State Univ, Dept Phys, Mankato, MN 56001 USA. NR 16 TC 1 Z9 2 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7993 EP 7995 DI 10.1063/1.1541648 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600118 ER PT J AU Hajndl, R Sanders, J Srikanth, H Dudney, NJ AF Hajndl, R Sanders, J Srikanth, H Dudney, NJ TI Growth and characterization of BSTO/hexaferrite composite thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BARIUM STRONTIUM-TITANATE; MAGNETIC RECORDING MEDIA; HEXAGONAL FERRITES AB Ferroelectric/ferrite composite films are excellent systems in which the electromagnetic material properties can be tuned through changes in composition as well as microstructure. We report on our studies of the structural and magnetic properties of Ba0.5Sr0.5TiO3/BaFe12O19 (BSTO/BaM) composite thin films deposited on Al2O3 substrates using magnetron sputtering. Optimizing the sputtering conditions and postdeposition annealing lead to high-quality films without any impurity phases. Magnetic measurements yield saturation magnetization values in the range of 100 to 200 emu/cm(3). Hysteresis loops exhibit a double transition that is observed only in the composite films and not in pure hexaferrite films grown under identical deposition conditions. The unusual feature in the M-H data is ascribed to the possibility of magnetodielectric effects associated with intergranular magnetic coupling mediated by the BSTO polarization layer. (C) 2003 American Institute of Physics. C1 Univ S Florida, Dept Phys, Tampa, FL 33620 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Srikanth, H (reprint author), Univ S Florida, Dept Phys, Tampa, FL 33620 USA. RI Dudney, Nancy/I-6361-2016 OI Dudney, Nancy/0000-0001-7729-6178 NR 17 TC 8 Z9 8 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 7999 EP 8001 DI 10.1063/1.1543129 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600120 ER PT J AU Guo, ZJ Jiang, JS You, CY Vlasko-Vlasov, VK Welp, U Liu, JP Bader, SD AF Guo, ZJ Jiang, JS You, CY Vlasko-Vlasov, VK Welp, U Liu, JP Bader, SD TI Exchange coupling in epitaxial Sm-Co(1(1)over-bar-00)/Nd-Co exchange-spring bilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PERMANENT-MAGNETS AB We have studied the exchange coupling behavior of the epitaxial Nd-Co(1 (1) over bar 00)/Sm-Co exchange-spring bilayers. A shifted and asymmetric magnetic hysteresis loop of Nd-Co was recorded at room temperature with the exchange field H-ex=-625 Oe. The magnitude of H-ex increases with increasing temperature from 300 to 350 K, which is due to the temperature-dependent magnetic anisotropy of the Nd-Co layer, and decreases with decreasing temperature because of the spin reorientation of the Nd-Co layer around 250 K. The coercive field of the pinned Nd-Co(1000 Angstrom) layer was not varied systematically by exchange coupling, compared with that of the free single layer. The temperature dependence of H-ex above 300 K has been simulated using a one-dimensional model. The result suggests that one can enhance H-ex, hence, the maximum size of the soft phase for the effective exchange-spring coupling, by tailoring the magnetic anisotropy of the soft phase. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Louisiana Tech Univ, Inst Micromfg, Ruston, LA 71272 USA. Louisiana Tech Univ, Inst Mfg, Ruston, LA 71272 USA. RP Guo, ZJ (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI You, Chun-Yeol/B-1734-2010; Bader, Samuel/A-2995-2013 OI You, Chun-Yeol/0000-0001-9549-8611; NR 14 TC 3 Z9 3 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8122 EP 8124 DI 10.1063/1.1538180 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600161 ER PT J AU L'abbe, C Meersschaut, J Rots, M Bader, SD AF L'abbe, C Meersschaut, J Rots, M Bader, SD TI Fluctuating spin density waves revealed by perturbed angular correlation spectroscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BIQUADRATIC EXCHANGE; MAGNETIC MULTILAYERS; COPPER SURFACES; CHROMIUM; ANTIFERROMAGNETISM; MECHANISM; FIELDS; INDIUM; ORIGIN AB We present a theory to analyze pertubed angular correlation spectra in the framework of dynamical processes. It can be applied to study superparamagnetic properties of magnetic nanostructures, and was used recently to identify dynamical fluctuations in spin-density-wave ordered Cr. We showed that the spin fluctuations give rise to the biquadratic coupling in Fe/Cr(100) multilayers [J. Meersschaut, C. L'abbe, M. Rots, and S. D. Bader, Phys. Rev. Lett. 87 107201 (2001)]. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Katholieke Univ Leuven, Inst Kern & Stralingsfys, B-3001 Louvain, Belgium. RP L'abbe, C (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 22 TC 2 Z9 2 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8250 EP 8252 DI 10.1063/1.1558652 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600201 ER PT J AU Tang, H Pecharsky, AO Schlagel, DL Lograsso, TA Pecharsky, VK Gschneidner, KA AF Tang, H Pecharsky, AO Schlagel, DL Lograsso, TA Pecharsky, VK Gschneidner, KA TI Magnetic field induced phase transitions in Gd-5(Si1.95Ge2.05) single crystal and the anisotropic magnetocaloric effect SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRICAL-RESISTANCE; GD-5(SI2GE2); GD-5(SIXGE1-X)(4); GD-5(SI1.5GE2.5); GD-5(SI1.8GE2.2); GD5SI4-GD5GE4; BEHAVIOR; SYSTEM AB Magnetization measurements using a Gd-5(Si1.95Ge2.05) single crystal with the magnetic field applied along three crystallographic directions, [001], [010] and [100], were carried out as a function of the applied field (0-56 kOe) at various temperatures (similar to5-320 K). The magnetic field (H)-temperature (T) phase diagrams were constructed for the Gd-5(Si1.95Ge2.05) single crystal with field along the three directions. A small anisotropy was observed. The magnetocaloric effect was calculated from isothermal magnetization data, and the observed anisotropy correlates with the H-T phase diagrams. The results are discussed in connection with the magnetic field induced martensitic-like structural transition observed in Gd-5(Si2Ge2)-type compounds. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Met & Ceram Sci Program, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Tang, H (reprint author), Iowa State Univ, Ames Lab, Met & Ceram Sci Program, Ames, IA 50011 USA. NR 13 TC 20 Z9 20 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8298 EP 8300 DI 10.1063/1.1556259 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600215 ER PT J AU Alsmadi, AM Nakotte, H Sarrao, JL Jung, MH Lacerda, AH AF Alsmadi, AM Nakotte, H Sarrao, JL Jung, MH Lacerda, AH TI Pressure and magnetic field effects in CeNiGe2 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CE; HEAT AB CeNiGe2 crystallizes in the orthorhombic CeNiSi2-type layered structure and exhibits large magnetic and transport anisotropy. The compound undergoes two antiferromagnetic transitions at T-N=4 K and T-M=3 K. We report measurement of the electrical resistivity on a CeNiGe2 single crystal as a function of the temperature and magnetic field (i parallel to b axis, H perpendicular to b axis) performed under hydrostatic pressure up to 9 kbar. Upon application of magnetic field, antiferromagnetic transitions merge into a single transition and this transition is completely suppressed in fields greater than 5 T. Application of pressure causes a reduction of the ordering temperatures. The results are compared with findings for other Ce compounds and discussed in terms of moment instability and the variation of exchange due to increased 4f-ligand hybridization. (C) 2003 American Institute of Physics. C1 New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Los Alamos Natl Lab, Los Alamos Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Natl High Magnet Field Lab, Pulse Field Facil, Los Alamos, NM 87545 USA. RP New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. EM aalsmadi@nmsu.edu NR 20 TC 4 Z9 4 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8343 EP 8345 DI 10.1063/1.1556277 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600230 ER PT J AU El-Khatib, S Chang, S Nakotte, H Brown, D Bruck, E Schultz, AJ Christianson, A Lacerda, A AF El-Khatib, S Chang, S Nakotte, H Brown, D Bruck, E Schultz, AJ Christianson, A Lacerda, A TI Low-temperature magnetic structure of UPdGe SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB We report on the low-temperature magnetic structure of UPdGe, which crystallizes in the orthorhombic TiNiSi structure. Magnetic space group analysis was employed to determine potential moment configuration allowed by crystal symmetry. By fitting the allowed models to neutron diffraction results, we find that UPdGe orders ferromagnetically below T-C=28 K with collinear uranium moments of about 1.5 mu(B)/U atom pointing along the orthorhombic b axis at 5 K. (C) 2003 American Institute of Physics. C1 New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Los Alamos Natl Lab, LANSCE 12, Los Alamos, NM 87545 USA. Univ Amsterdam, Van Waals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Argonne Natl Lab, IPNS, Argonne, IL 60439 USA. Natl High Magnet Field Lab, Pulse Field Facil, Los Alamos, NM 87545 USA. RP El-Khatib, S (reprint author), New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RI Bruck, Ekkes/E-3365-2014; christianson, andrew/A-3277-2016; OI christianson, andrew/0000-0003-3369-5884; Bruck, Ekkes/0000-0002-5063-3338 NR 15 TC 5 Z9 5 U1 2 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8352 EP 8354 DI 10.1063/1.1556281 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600233 ER PT J AU Kakazei, GN Wigen, PE Guslienko, KY Chantrell, RW Lesnik, NA Metlushko, V Shima, H Fukamichi, K Otani, Y Novosad, V AF Kakazei, GN Wigen, PE Guslienko, KY Chantrell, RW Lesnik, NA Metlushko, V Shima, H Fukamichi, K Otani, Y Novosad, V TI In-plane and out-of-plane uniaxial anisotropies in rectangular arrays of circular dots studied by ferromagnetic resonance SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIC ANISOTROPIES; MULTILAYERS; SINGLE AB Ferromagnetic resonance at 9.2 GHz (X band) was used to characterize the uniaxial magnetic anisotropies in rectangular arrays of submicron circular Ni dots. The in-plane anisotropy, originated from interdot interactions in the rectangular lattice, and the perpendicular anisotropy, due to individual dot shape and magnetostriction, were explored. For in-plane dependencies of the resonance field (H-r), the main resonance mode angular dependence was well described by the standard Kittel formula. As the interdot distances decreased from 800 to 50 nm, the in-plane uniaxial anisotropy field changed from 5 to 130 Oe, in reasonable agreement with calculations. Simultaneously, the position of perpendicular H-r increased from 6.38 to 6.83 kOe, also following Kittel's formula. (C) 2003 American Institute of Physics. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Seagate Res, Pittsburgh, PA 15222 USA. Natl Acad Sci Ukraine, Inst Magnetism, UA-03142 Kiev, Ukraine. Univ Illinois, Dept Elect Engn & Comp Sci, Chicago, IL 60607 USA. Tohoku Univ, Grad Sch Engn, Sendai, Miyagi 9808579, Japan. RIKEN, Saitama 3510198, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. EM kakazey.1@osu.edu RI Kakazei, Gleb/A-5106-2008; Novosad, Valentyn/C-2018-2014; OTANI, Yoshichika/I-5884-2012; Chantrell, Roy/J-9898-2015; Novosad, V /J-4843-2015 OI Kakazei, Gleb/0000-0001-7081-581X; OTANI, Yoshichika/0000-0001-8008-1493; Chantrell, Roy/0000-0001-5410-5615; NR 10 TC 39 Z9 39 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8418 EP 8420 DI 10.1063/1.1556978 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600255 ER PT J AU Melikhov, Y Lee, SJ Jiles, DC Schmidt, DH Porter, MD Shinar, R AF Melikhov, Y Lee, SJ Jiles, DC Schmidt, DH Porter, MD Shinar, R TI Microelectromagnetic ferrofluid-based actuator SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PARTICLES; SYSTEMS; DESIGN AB Computer simulations were used to investigate the performance of a microscale ferrofluid-based magnetic actuator developed for liquid dispensing in microfluidic channels. The actuation was based on the movement of a ferrofluid plug in a magnetic field gradient generated by on-chip effectively infinite parallel conductors. The movement, positioning, and retaining of ferrofluid plugs with different lengths at various locations along a microfluidic channel were investigated for two cases. In case (a), the magnetic field gradient was generated by a single conductor; when the ferrofluid reached its equilibrium position, the current was switched off and the nearest neighbor conductor was energized. A similar, consecutive on/off current switching was performed for case (b), where a set of conductors was energized simultaneously. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Ctr Microelect Res, Ames, IA 50011 USA. Iowa State Univ, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. RP Melikhov, Y (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 6 TC 14 Z9 14 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8438 EP 8440 DI 10.1063/1.1540164 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600262 ER PT J AU Li, L Jiles, DC AF Li, L Jiles, DC TI Modeling of the magnetomechanical effect: Application of the Rayleigh law to the stress domain SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIZATION; COBALT; NICKEL AB Stress is one of the principal external factors affecting the magnetization of materials. The magnetomechanical effect, that is, the change of magnetization of a magnetic material resulting from the application of stress, has attracted attention because of its scientific complexity. An improved model equation for interpreting the magnetomechanical effect has been developed based on extension of the previous equation to include the Rayleigh law. According to the previous theory of the magnetomechanical effect, which is based on the "law of approach," application of stress induces changes in magnetization toward anhysteretic magnetization which itself is stress dependent, and the rate of change of magnetization with the input elastic energy is dependent on the displacement of the prevailing magnetization from the anhysteretic magnetization. The theory has been refined by including a linear term in the model equation in addition to the well-known quadratic term. It was found that the modified theory provides a much better description of the magnetization changes under stress, particularly at small applied stress amplitudes and when the stress changes sign. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Li, L (reprint author), Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 7 TC 16 Z9 20 U1 0 U2 10 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 MAY 15 PY 2003 VL 93 IS 10 BP 8480 EP 8482 DI 10.1063/1.1540059 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600276 ER PT J AU Han, M Jiles, DC Snyder, JE Lo, CCH Leib, JS Paulsen, JA Pecharsky, AO AF Han, M Jiles, DC Snyder, JE Lo, CCH Leib, JS Paulsen, JA Pecharsky, AO TI Thermal expansion studies on the unusual first order transition of Gd5Si2.09Ge1.91: effects of purity of Gd SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHASE-RELATIONSHIPS; GD5SI4-GD5GE4; SYSTEM AB Two polycrystalline samples were made by using high purity Gd and commercial Gd, respectively, but with Si and Ge starting materials of the same purity in both cases. Thermal expansion results showed that both samples exhibited a first order phase transformation, with a discontinuity in thermally-induced strain and with hysteresis in the Curie temperature. Magnetic force microscopy has been used to demonstrate the magnetic phase transformation process from paramagnetic to ferromagnetic upon cooling. It was found that the Curie temperature was lower and the thermally-induced strain higher, in the sample made from lower purity level Gd starting materials compared with the sample made from high purity Gd metal. These results indicate that the impurities (mainly C, O, N, and F) in the Gd starting material can significantly alter the strain and Curie temperature of Gd-5(SixGe1-x)(4) alloys. (C) 2003 American Institute of Physics. C1 US DOE, Met & Ceram Sci Div, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. RP Han, M (reprint author), US DOE, Met & Ceram Sci Div, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 6 TC 4 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8486 EP 8488 DI 10.1063/1.1540060 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600278 ER PT J AU Kellogg, RA Flatau, AB Clark, AE Wun-Fogle, M Lograsso, TA AF Kellogg, RA Flatau, AB Clark, AE Wun-Fogle, M Lograsso, TA TI Texture and grain morphology dependencies of saturation magnetostriction in rolled polycrystalline Fe83Ga17 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AL ALLOYS; FE-GA AB Textured polycrystalline Fe-Ga alloys exhibit magnetostrictive strains of 100 ppm or greater and may function as a mechanically robust actuator/sensing material. Current efforts seek to combine the 300+ ppm magnetostrictive strain performance of [100] oriented single crystals with the mechanical properties of polycrystalline forms. One approach to combining these properties is to control the crystallographic texture through deformation processing such as rolling. To determine the relationship between saturation magnetostriction, degree of texturing, and grain morphology we compare the results of three-dimensional finite element simulations with the analytical solution for a random polycrystal and the experimental responses of rolled polycrystalline Fe83Ga17. Textured specimens were produced through rolling reductions up to 99% of an as-cast ingot and a subsequent 1100 or 590 degreesC anneal. The high temperature anneal produced a recrystallized grain structure having a wide variation in crystal orientation as determined by orientation imaging microscopy. This recrystallized specimen exhibited a net magnetostriction of similar to170 ppm in the rolling direction and was well correlated with the finite element model result. The low temperature annealed specimen possessed fine elongated grains having dispersed {001}[110] and {111}[211] textures. Net magnetostrictions of 30 and 37 ppm were measured in the rolling direction and 45degrees off the rolling direction, respectively. The low magnetostriction value in the 45degrees direction disagrees substantially with the finite element solution of 157 ppm and suggests that unknown factors are dominating the response. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Ames, IA 50011 USA. Clark Associates, Adelphi, MD 20783 USA. Naval Surface Warfare Ctr, Carderock Div, Bethesda, MD 20817 USA. Ames Lab, Ames, IA 50011 USA. RP Kellogg, RA (reprint author), Iowa State Univ, Ames, IA 50011 USA. NR 10 TC 25 Z9 31 U1 0 U2 10 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 MAY 15 PY 2003 VL 93 IS 10 BP 8495 EP 8497 DI 10.1063/1.1540062 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600281 ER PT J AU Leib, J Lo, CCH Snyder, JE Jiles, DC AF Leib, J Lo, CCH Snyder, JE Jiles, DC TI In situ applied field imaging of a magnetic tunnel junction using magnetic force microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Knowledge of domain behavior in magnetic tunnel junctions is an essential component, together with knowledge of the electron band structure, for understanding their magnetoelectronic properties. To this purpose, the magnetization reversal processes of a multilayer tunnel junction of structure substrate/NiFe/AlOx/FeCo/CrPtMn/Al of tapered half-ellipsoid shape have been imaged using a magnetic force microscope (MFM) with in situ applied magnetic fields. Stripe domains through both the stack and free layers observed at zero applied field were erased by a similar to100 Oe field applied to the left followed by applying a small field to the right. Magnetic domain structure did not reappear in the MFM images until a field of similar to400 Oe was applied to the right. This domain pattern then persisted when the magnetic field was reduced to zero. A drastic difference in domain patterns throughout the rotational processes to saturation in each direction was also observed. When the field was applied to the left, domain walls rotated toward the direction perpendicular to the applied field before disappearing. However, in near-saturation fields to the right, domain walls formed nearly parallel to the applied field and rotated away from parallel as the applied field strength was decreased. From these images, therefore, significant insight has been gained into the magnetization processes and physical phenomena behind the magnetoresistive behavior of these junctions. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Leib, J (reprint author), Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 3 TC 0 Z9 0 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8537 EP 8539 DI 10.1063/1.1540128 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600295 ER PT J AU Tsai, SH Landau, DP Schulthess, TC AF Tsai, SH Landau, DP Schulthess, TC TI Effect of interfacial coupling on the magnetic ordering in ferro-antiferromagnetic bilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EXCHANGE BIAS; ANISOTROPY; FILMS AB Monte Carlo simulations have been used to study magnetic ordering in coupled anisotropic ferro/antiferromagnetic (FM/AFM) films of classical Heisenberg spins. We consider films with flat interfaces that are fully uncompensated as well as rough interfaces that are compensated on average. For both types of interfaces above the "Neel temperature" we observed order in the AFM with the AFM spins aligning collinearly with the FM moments. In the case of rough interfaces there is a transition from collinear to perpendicular alignment of the FM and AFM spins at a lower temperature. (C) 2003 American Institute of Physics. C1 Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. Univ Georgia, Enterprise Informat Technol Serv, Athens, GA 30602 USA. Oak Ridge Natl Lab, Ctr Computat Sci & Comp Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math, Oak Ridge, TN 37831 USA. RP Tsai, SH (reprint author), Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. NR 13 TC 28 Z9 28 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8612 EP 8614 DI 10.1063/1.1557794 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600320 ER PT J AU Clark, AE Hathaway, KB Wun-Fogle, M Restorff, JB Lograsso, TA Keppens, VM Petculescu, G Taylor, RA AF Clark, AE Hathaway, KB Wun-Fogle, M Restorff, JB Lograsso, TA Keppens, VM Petculescu, G Taylor, RA TI Extraordinary magnetoelasticity and lattice softening in bcc Fe-Ga alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AL ALLOYS AB Extraordinary magnetostrictive behavior has been observed in Fe-Ga alloys with concentrations of Ga between 4% and 27%. lambda(100) exhibits two peaks as a function of Ga content. At room temperature, lambda(100) reaches a maximum of 265 ppm near 19% Ga and 235 ppm near 27% Ga. For compositions between 19% and 27%, lambda(100) drops sharply to a minimum near 24% Ga and exhibits an anomalous temperature dependence, decreasing by as much as a factor of 2 at low temperatures. This unusual magnetostrictive behavior is interpreted on the basis of a single maximum in the magnetoelastic coupling \b(1)\ of Fe with increasing amounts of nonmagnetic Ga, combined with a strongly temperature dependent elastic shear modulus (c(11)-c(12)) which approaches zero near 27% Ga. lambda(111) is significantly smaller in magnitude than lambda(100) over this composition range, and has an abrupt change in sign from negative for low Ga concentrations to positive for a concentration of Ga near 21%. (C) 2003 American Institute of Physics. C1 Clark Associates, Adelphi, MD 20783 USA. Off Naval Res, Arlington, VA 22217 USA. USN, Ctr Surface Warfare, Bethesda, MD 20817 USA. Ames Lab, Ames, IA 50011 USA. Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. Univ Mississippi, Natl Ctr Phys Acoust, University, MS 38677 USA. RP Clark, AE (reprint author), Clark Associates, Adelphi, MD 20783 USA. OI Taylor, Richard/0000-0002-9082-6644 NR 8 TC 285 Z9 304 U1 3 U2 40 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 MAY 15 PY 2003 VL 93 IS 10 BP 8621 EP 8623 DI 10.1063/1.1540130 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600323 ER PT J AU Dai, LY Cullen, J Wuttig, M Lograsso, T Quandt, E AF Dai, LY Cullen, J Wuttig, M Lograsso, T Quandt, E TI Magnetism, elasticity, and magnetostriction of FeCoGa alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB It is known that the substitution of Co for Fe gives rise to increases in magnetization and Curie temperature, not only in the bcc metals, but also in intermetallic compounds and alloys as well. With the expectation that this is the case in Co-substituted FeGa, we measured magnetization, Curie temperature, magnetostriction and elastic constants of a series of polycrystalline FeCoGa ternary alloys with up to 17% Ga and up to 10% Co. The magnetostriction at saturation for Fe0.93-xCo.07Gax increases to 90 ppm for x=0.17. For larger percentages of Co, the rise in magnetostriction is not as sharp as it is in the 7% case. The shear elastic modulus decreases with Ga, again in keeping with the results for FeGa. The magnetostriction and the elastic constants are sensitive to sample preparation for the high-Ga material. We conclude that the substitution of small (<0.10) percentages of Co for Fe in bcc FeCoGa alloys enhances the magnetic and magnetostrictive properties of the parent FeGa material. (C) 2003 American Institute of Physics. C1 Univ Maryland, Dept Mat Sci, College Pk, MD 20742 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Bonn, Caesar Res Ctr, D-53111 Bonn, Germany. RP Dai, LY (reprint author), Univ Maryland, Dept Mat Sci, College Pk, MD 20742 USA. RI Wuttig, Manfred/A-8763-2012 NR 6 TC 16 Z9 21 U1 2 U2 18 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 MAY 15 PY 2003 VL 93 IS 10 BP 8627 EP 8629 DI 10.1063/1.1555980 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600325 ER PT J AU Mulcahy, TM Hull, JR Rozendaal, E Wise, JH Turner, LR AF Mulcahy, TM Hull, JR Rozendaal, E Wise, JH Turner, LR TI Improving sintered NdFeB permanent magnets by powder compaction in a 9 T superconducting solenoid SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Commercial-grade magnet powder (Magnequench UG) was axial die pressed in the 76.2 mm warm bore of a 9 T superconducting solenoid. Otherwise, processing was performed as part of normal factory operations. This pressing was done to improve the alignment of the anisotropic single-crystal particles of the compact and, thus, the remanent magnetization of the sintered cylindrical permanent magnets (12.7 mm diameter). Although the press was operated in batch mode for this proof-of-concept study, its design enables automated production. Improvements of up to 8% in magnetization and 16% in energy products were obtained, as the alignment field H was increased above the 2 T maximum field of electromagnets used in industry. The greatest improvements were obtained for magnets with the smallest length-to-diameter ratios, L/D<0.5. The production of quality magnets in this near-final-shape size range is currently being pursued by industry to eliminate expensive machining steps. To understand the potential for 2-8 T alignment fields to overcome the distortions created in the otherwise uniform field by the self-field of short compacts, electromagnetic code (Opera) calculations were made. A simple material model was used to predict the distortions. The trends in the predicted field-line inclinations, with L/D and H, compare to trends in the improvement of the magnetic properties. (C) 2003 American Institute of Physics. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Magnequench UG, Valparaiso, IN 46383 USA. Vector Fields, Aurora, CO USA. RP Mulcahy, TM (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 TC 0 Z9 0 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2003 VL 93 IS 10 BP 8680 EP 8682 DI 10.1063/1.1544525 PN 3 PG 3 WC Physics, Applied SC Physics GA 677TA UT WOS:000182822600343 ER PT J AU Fujdala, KL Tilley, TD AF Fujdala, KL Tilley, TD TI Design and synthesis of heterogeneous catalysts: the thermolytic molecular precursor approach SO JOURNAL OF CATALYSIS LA English DT Review DE molecular precursors; oxidative dehydrogenation; selective oxidation; oxide catalysts; epoxidation; site isolation; catalyst synthesis ID MG-O CATALYSTS; PROPANE OXIDATIVE DEHYDROGENATION; RESOLUTION ELECTRON-MICROSCOPY; SILICA EPOXIDATION CATALYSTS; VANADIUM-OXIDE CATALYSTS; IRON PHOSPHATE CATALYSTS; LIQUID-PHASE OXIDATION; SHORT-CHAIN ALKANES; SELECTIVE OXIDATION; TITANIA-SILICA AB The use of the thermolytic molecular precursor (TMP) method for the generation of multicomponent oxide materials is reviewed with emphasis on the generation of catalysts and catalyst support materials. Various adaptations of the TMP method that allow manipulation of catalyst compositions are presented. Further, the generation of isolated catalytic centers via grafting techniques is summarized. The implications for syntheses of new catalysts and catalyst formulations are discussed, and specific examples that involve selective hydrocarbon oxidation catalysts are provided. (C) 2003 Elsevier Science (USA). All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 160 TC 72 Z9 72 U1 2 U2 40 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD MAY 15 PY 2003 VL 216 IS 1-2 BP 265 EP 275 DI 10.1016/S0021-9517(02)00106-9 PG 11 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 684VH UT WOS:000183226900025 ER PT J AU Niklasson, AMN Tymczak, CJ Challacombe, M AF Niklasson, AMN Tymczak, CJ Challacombe, M TI Trace resetting density matrix purification in O/(N) self-consistent-field theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LINEAR SCALING COMPUTATION; ELECTRONIC-STRUCTURE CALCULATIONS; BINDING MOLECULAR-DYNAMICS; POLARIZED ATOMIC ORBITALS; FOCK MATRIX; FUNCTIONAL-THEORY; EXCHANGE MATRIX; CONVERGENCE ACCELERATION; PARALLEL COMPUTERS; COULOMB MATRIX AB A new approach to linear scaling construction of the density matrix is proposed, based on trace resetting purification of an effective Hamiltonian. Trace resetting is related to the trace preserving canonical purification scheme of Palser and Manolopoulos [Phys. Rev. B 58, 12704 (1999)] in that they both work with a predefined occupation number and do not require adjustment or prior knowledge of the chemical potential. In the trace resetting approach, trace conservation is not strictly enforced, allowing greater flexibility in the choice of purification polynomial and improved performance for Hamiltonian systems with high or low filling. However, optimal polynomials may in some cases admit unstable solutions, requiring a resetting mechanism to bring the solution back into the domain of convergent purification. A quartic trace resetting method is developed, along with analysis of stability and error accumulation due to incomplete sparse-matrix methods that employ a threshold tau to achieve sparsity. It is argued that threshold metered purification errors in the density matrix are O(tauDeltag(-1)) at worst, where Deltag is the gap at the chemical potential. In the low filling regime, purification derived total energies are shown to converge smoothly with tau(2) for RPBE/STO-6G C60 and a RPBE0/STO-3G Ti substituted zeolite. For the zeolite, the quartic trace resetting method is found to be both faster and over an order of magnitude more accurate than the Palser-Manolopoulos method. In the low filling limit, true linear scaling is demonstrated for RHF/6-31G** water clusters, and the trace resetting method is found to be both faster and an order of magnitude more accurate than the Palser-Manolopoulos scheme. Basis set progression of RPBE chlorophyll reveals the quartic trace resetting to be up to four orders of magnitude more accurate than the Palser-Manolopoulos algorithm in the limit of low filling. Furthermore, the ability of trace resetting and trace preserving algorithms to deal with degeneracy and fractional occupation is discussed. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Niklasson, AMN (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM amn@lanl.gov; Tymczak@lanl.gov; mchalla@lanl.gov NR 57 TC 66 Z9 66 U1 1 U2 13 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 MAY 15 PY 2003 VL 118 IS 19 BP 8611 EP 8620 DI 10.1063/1.1559913 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 673WJ UT WOS:000182603000010 ER PT J AU Endres, RG LaBute, MX Cox, DL AF Endres, RG LaBute, MX Cox, DL TI Theory of adiabatic hexaamminecobalt self-exchange SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL CALCULATIONS; ELECTRON-TRANSFER REACTIONS; FIRST-PRINCIPLES; LARGE SYSTEMS; SPECTRA; PSEUDOPOTENTIALS; FORMALISM; ENERGIES; CRYSTAL; SERIES AB We have reexamined the thermally induced Co(NH3)(6)(2+/3+) [Co(II/III)] redox reaction using the first-principles density-functional-theory method, semiclassical Marcus theory, and known charge transfer parameters. We find support for a previously suggested mechanism involving the excited state (E-2(g)) of Co(II) which becomes lower than the ground state (T-4(1g)) in the transition state region. This lowers the transition-state barrier considerably by similar to6.9 kcal/mol and leads to a spin-allowed and adiabatic electron exchange process. Our calculations are consistent with previous experimental results regarding the spin-excitation energy (T-3(1g)) of Co(III) and the fact that an optical absorption peak (E-2(g)) of the Co(II) species could not be found experimentally. Our rate is of order 6x10(-3) (M s)(-1) and hence two orders of magnitude faster than determined previously by experiments. (C) 2003 American Institute of Physics. C1 Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Endres, RG (reprint author), Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. NR 51 TC 5 Z9 5 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 2003 VL 118 IS 19 BP 8706 EP 8714 DI 10.1063/1.1567255 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 673WJ UT WOS:000182603000019 ER PT J AU Chang, TM Dang, LX AF Chang, TM Dang, LX TI On rotational dynamics of an NH4+ ion in water SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; AMMONIUM ION; AQUEOUS-SOLUTIONS; HALIDE-IONS; AB-INITIO; SIMULATION; SOLVATION; CLUSTERS; HYDRATION; MOTION AB The structural, thermodynamic, and dynamical properties of a single ammonium ion, NH4+, in liquid water were investigated using molecular dynamic simulation techniques. Many-body polarizable model potentials were employed to describe the molecular interactions. The water molecules were found to form well-defined hydration shells with a preferred orientation around the NH4+ ion as expected. We also found that the average water dipole moment is enhanced in the first hydration shell. The translational and rotational motion of NH4+ was examined via the velocity, angular-momentum, and reorientation-autocorrelation functions. The computed rotational diffusion coefficients of the NH4+ ion in water, which were determined from the angular momentum autocorrelation function and the angular mean-square displacement, are 0.093 and 0.067x10(12) rad(2)/s, respectively. These results are in good agreement with the experimental nuclear magnetic resonance value of 0.075x10(12) rad(2)/s. (C) 2003 American Institute of Physics. C1 Univ Wisconsin Parkside, Dept Chem, Kenosha, WI 53140 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Chang, TM (reprint author), Univ Wisconsin Parkside, Dept Chem, Kenosha, WI 53140 USA. NR 28 TC 17 Z9 17 U1 3 U2 19 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 MAY 15 PY 2003 VL 118 IS 19 BP 8813 EP 8820 DI 10.1063/1.1566435 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 673WJ UT WOS:000182603000030 ER PT J AU Osterbacka, R Wohlgenannt, M Shkunov, M Chinn, D Vardeny, ZV AF Osterbacka, R Wohlgenannt, M Shkunov, M Chinn, D Vardeny, ZV TI Excitons, polarons, and laser action in poly(p-phenylene vinylene) films SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PI-CONJUGATED POLYMERS; LIGHT-EMITTING-DIODES; LADDER-TYPE POLY(PARA-PHENYLENE); NONLINEAR-OPTICAL PROPERTIES; STIMULATED-EMISSION; ELECTROABSORPTION SPECTROSCOPY; SEMICONDUCTING POLYMERS; 3RD-HARMONIC GENERATION; TRANSIENT-ABSORPTION; CONDUCTING POLYMERS AB We have used a multitude of linear and nonlinear cw optical spectroscopies to study the optical properties of water precursor poly(p-phenylene vinylene) (PPV) thin films. These spectroscopies include absorption, photoluminescence, photoinduced absorption and their respective optically detected magnetic resonance, and electroabsorption spectroscopy. We have studied singlet and triplet excitons, polarons, and laser action in PPV films. We found that the lowest-lying absorption band is excitonic in origin. It consists of two absorption components due to a bimodal distribution of the polymer chain conjugation lengths. Electroabsorption spectroscopy unambiguously shows the positions of the lowest-lying odd parity exciton 1B(u) at 2.59 eV and two of the higher-lying even-parity excitons, namely, mA(g) at 3.4 eV and kA(g) at 3.7 eV. From these exciton energies we obtained a lower bound for the exciton binding energy in PPV, E(b)(min)=E(mA(g))-E(1B(u))=0.8 eV. The quantum efficiency spectrum for triplet exciton photogeneration consists of two contributions; the intersystem crossing and, at higher energies, singlet fission. From the onset of the singlet fission process at E(SF)=2E(T), we could estimate the energy of the lowest-lying triplet exciton, 1 (3)B(u), at 1.55 eV, with a singlet-triplet splitting as large as 0.9 eV. From photoinduced absorption spectroscopy we measured the triplet-triplet transition, T-->T(*), to be 1.45 eV. The quantum efficiency spectrum for polaron photogeneration also consists of two contributions: one extrinsic and the other intrinsic. The latter shows a monotonically increasing function of energy with an energy onset at 3.3 eV. The intrinsic photogeneration process is analyzed with a model of free-electron-hole pair photogeneration, which separate more effectively at higher energy. The carrier generation quantum yield at 3.65 eV is estimated to be 0.5%. The quantum efficiency for photoluminescence, on the other hand, shows one single step-function process, with an onset at 2.4 eV. The photoluminescence spectrum is well structured, showing five phonon side bands with 190 meV separation. We have also studied laser action in PPV thin films and microcavities such as microrings and microdisks. The effective gain spectrum is calculated and the estimated threshold excitation intensity for laser action for the 0-1 transition is found to be in good agreement with the data, with an estimated exciton density of 2x10(18) cm(-3). Lasing from microring devices shows several narrow waveguide modes, with intermode spacing of 0.45 nm that corresponds to an effective mode refractive index, n(eff)=1.45. The spectral width of the laser modes is resolution limited and gives a lower estimate of the cavity quality factor, Q. For microrings we found Q>5000, which is limited by self-absorption in the polymer film. (C) 2003 American Institute of Physics. C1 Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. Abo Akad Univ, Dept Phys, FIN-20500 Turku, Finland. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Merck Specialty Chem Ltd, Southampton SO16 7QD, Hants, England. Sandia Natl Labs, Livermore, CA 94551 USA. RP Osterbacka, R (reprint author), Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. EM rosterba@abo.fi RI Osterbacka, Ronald/I-9161-2012 OI Osterbacka, Ronald/0000-0003-0656-2592 NR 89 TC 53 Z9 53 U1 5 U2 36 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 MAY 15 PY 2003 VL 118 IS 19 BP 8905 EP 8916 DI 10.1063/1.1566937 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 673WJ UT WOS:000182603000041 ER PT J AU Cui, ST McCabe, C Cummings, PT Cochran, HD AF Cui, ST McCabe, C Cummings, PT Cochran, HD TI Molecular dynamics study of the nano-rheology of n-dodecane confined between planar surfaces SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHASE-TRANSITIONS; COMPLEX FLUIDS; SIMPLE LIQUIDS; SHEAR; BEHAVIOR; FILMS; TETRACOSANE; ALKANES AB Realistic molecular simulations agree with previously published surface force experiments that n-dodecane confined between mica surfaces displays shear-thinning starting at shear rate orders of magnitude less than in the bulk fluid. We probe the origin of this behavior by studying rotational and diffusional relaxations in the simulated fluid and find a freezing-out of the rotational degrees of freedom and a power-law diffusional relaxation, resulting in over seven orders of magnitude increase in the relaxation time. (C) 2003 American Institute of Physics. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. RP Cui, ST (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI McCabe, Clare/I-8017-2012; Cummings, Peter/B-8762-2013 OI McCabe, Clare/0000-0002-8552-9135; Cummings, Peter/0000-0002-9766-2216 NR 23 TC 49 Z9 49 U1 1 U2 13 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 MAY 15 PY 2003 VL 118 IS 19 BP 8941 EP 8944 DI 10.1063/1.1568084 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 673WJ UT WOS:000182603000044 ER PT J AU Liu, HH Bodvarsson, GS AF Liu, HH Bodvarsson, GS TI Upscaling of constitutive relations in unsaturated heterogeneous tuff matrix SO JOURNAL OF HYDROLOGY LA English DT Article DE unsaturated flow; Yucca Mountain; vadose zone hydrology; relative permeability ID FRACTIONAL GAUSSIAN-NOISE; HYDRAULIC CONDUCTIVITIES; SUBSURFACE HYDROLOGY; PERCOLATION THEORY; FRACTURE NETWORK; POROUS-MEDIA; SCALE; MODEL; PERMEABILITY; FLOW AB When numerical models are used for modeling large-scale flow and transport processes in the subsurface, upscaling is generally needed to determine large-scale hydraulic properties from small-scale measurements. This study is focused on the upscaling of constitutive relations (among relative permeability, capillary pressure, and saturation) for unsaturated tuff matrix (or a porous medium with a large air entry value). Unsaturated flow in tuff matrix is of interest at a number of existing and proposed waste disposal sites, as well as in connection with environmental contamination in and and semiarid regions. Based on the notion that a large air entry value corresponds to a spatially uniform capillary pressure distribution, even at a relatively large scale for steady-state unsaturated flow, we present an upscaling approach for constitutive relations of tuff matrix. Numerical experiments were used to verify and demonstrate the usefulness of the approach. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Liu, HH (reprint author), Lawrence Berkeley Natl Lab, Div Earth Sci, 1 Cyclotron Rd,Mailstop 90-1116, Berkeley, CA 94720 USA. NR 41 TC 7 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD MAY 15 PY 2003 VL 276 IS 1-4 BP 198 EP 209 DI 10.1016/S0022-1694(03)00071-4 PG 12 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 689BF UT WOS:000183471200014 ER PT J AU Nelson, NT Hu, Q Brusseau, ML AF Nelson, NT Hu, Q Brusseau, ML TI Characterizing the contribution of diffusive mass transfer to solute transport in sedimentary aquifer systems at laboratory and field scales SO JOURNAL OF HYDROLOGY LA English DT Article DE diffusion-mediated mass transfer; dispersivity coefficient; heterogeneous aquifer material; undisturbed core ID POROUS-MEDIA; DISPERSION; SIZE; VALIDITY; MODELS AB The multi-tracer test method was used to investigate the impact of diffusion-mediated mass-transfer processes associated with physical heterogeneity on solute transport in sedimentary aquifer systems at different scales. Three systems were examined: (1) a column packed with homogenized aquifer material, (2) undisturbed aquifer cores, and (3) a section of a semi-confined alluvial Tracer experiments were conducted using non-reactive tracers with different aquifer encompassing approximately 2000 m 2 aqueous diffusion coefficients, based on the assumption that the impact of diffusion-mediated mass-transfer processes on solute transport will be dependent upon the magnitude of the diffusion coefficient. For the homogenized packed column, the breakthrough curves for the different tracers were very similar, and the attendant dispersivities were identical. These results indicate. as would be expected, that physical-heterogeneity related diffusive mass transfer did not measurably contribute to solute transport in the homogeneously packed column. Conversely, the results obtained for the undisturbed aquifer cores indicate that diffusive mass transfer, possibly associated with diffusion between zones of lower and higher advection, contributed to solute transport in this system. For the field test, the magnitudes of the dispersivity coefficients were different for the different tracers. Thus, solute transport at the field scale appeared to be influenced by diffusive mass transfer, most likely associated with mass transfer between re-ions of lower and higher permeability. These results illustrate that tracer tests using tracers with different diffusivities can be used to help elucidate the relative contribution of diffusion-mediated mass transfer to solute transport. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Arizona, Dept Soil Water & Environm Sci, Tucson, AZ 85721 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Daniel B Stephens & Associates Inc, Albuquerque, NM 87109 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Brusseau, ML (reprint author), Univ Arizona, Dept Soil Water & Environm Sci, 429 Shantz Bldg 38, Tucson, AZ 85721 USA. RI Hu, Qinhong/C-3096-2009 OI Hu, Qinhong/0000-0002-4782-319X NR 19 TC 9 Z9 9 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD MAY 15 PY 2003 VL 276 IS 1-4 BP 275 EP 286 DI 10.1016/S0022-1694(03)00061-1 PG 12 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 689BF UT WOS:000183471200019 ER PT J AU Reibold, RA Poco, JF Baumann, TF Simpson, RL Satcher, JH AF Reibold, RA Poco, JF Baumann, TF Simpson, RL Satcher, JH TI Synthesis and characterization of a low-density urania (UO3) aerogel SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES; GEL; PELLETIZATION; FABRICATION; PELLETS; OXIDES AB We report the synthesis and characterization for the first example of a low-density urania aerogel. The monolithic aerogels were prepared through the sol-gel polymerization of hydrated uranyl nitrate in ethanol using propylene oxide as a gelation initiator. The dried UO3 aerogel was characterized by high-resolution transmission electron microscopy and nitrogen adsorption/desorption analyses. The aerogel micro-structure was determined to be composed of primary particles with two distinct morphologies (spherical and fibrous) with features in the 5-20 nm range. These particles were also determined to be highly crystalline as evidenced by the higher-magnification TEM examination. The urania aerogel possesses high surface area (236 m(2)/g) and pore diameters in the micro- and mesoporous (2-20 nm) range. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP Satcher, JH (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808 L-092, Livermore, CA 94550 USA. NR 18 TC 19 Z9 20 U1 0 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD MAY 15 PY 2003 VL 319 IS 3 BP 241 EP 246 DI 10.1016/S0022-3093(03)00012-7 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 670WD UT WOS:000182431400004 ER PT J AU Gabriel, TA Haines, JR McManamy, TJ AF Gabriel, TA Haines, JR McManamy, TJ TI Overview of the Spallation Neutron Source (SNS) with emphasis on target systems SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB The status of the Spallation Neutron Source (SNS) is discussed. In addition, a more detailed overview is given of the Target Systems' part of the SNS with emphasis given to the technology issues that present the greatest scientific challenges. At present, SNS is within budget and schedule limits and excellent progress is being made on all fronts design, fabrication, installation, and testing. First beam on the Hg target system is expected in December 2005. The project, as of June 2002, was 42% complete. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Spallat Neutron Doutvr, Oak Ridge, TN 37830 USA. RP Gabriel, TA (reprint author), Spallat Neutron Doutvr, 701 Scarboro Rd,MS-6474, Oak Ridge, TN 37830 USA. NR 5 TC 24 Z9 25 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 1 EP 13 DI 10.1016/S0022-3115(03)00010-2 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900002 ER PT J AU Mansur, LK Hunn, JD Bauer, GS Ullmaier, H Dai, Y Maloy, SA AF Mansur, LK Hunn, JD Bauer, GS Ullmaier, H Dai, Y Maloy, SA TI Proceedings of the 5th International Workshop on Spallation Materials Technology (IWSMT-5) - Charleston, South Carolina, USA - May 19-24, 2002 - Foreword SO JOURNAL OF NUCLEAR MATERIALS LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Forschungszentrum Julich, Karlsruhe, Germany. Paul Scherrer Inst, Villigen, Switzerland. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mansur, LK (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 6 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP VII EP VIII PG 2 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900001 ER PT J AU Mansur, LK AF Mansur, LK TI Materials research and development for the spallation neutron source mercury target SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID STAINLESS-STEEL; MECHANICAL-PROPERTIES; CONTAINER MATERIALS; FATIGUE BEHAVIOR; IRRADIATION; ENVIRONMENT; SNS; ALLOY-718; HELIUM AB In the Spallation Neutron Source target, the structural material will be exposed to intense pulsed fluxes of high-energy protons and neutrons, which produce radiation damage. These pulsed fluxes also lead to pressure pulses created by beam heating. In turn, the pressure pulses give rise to fluctuating stresses in the 316 LN austenitic stainless steel target vessel, and to cavitation in the liquid mercury spallation target. Corrosion reactions and related changes in mechanical properties also may occur through contact with flowing mercury. We describe the materials research and development program for the spallation target. The program covers the areas of cavitation erosion, radiation effects, and compatibility. Cavitation erosion work includes pressure wave tests at the LANSCE proton accelerator, as well as laboratory tests that simulate aspects of the actual in-beam exposures. Materials irradiations are being carried out in spallation environments at high-energy and high-power proton accelerators. Other experiments are conducted at irradiation facilities that simulate aspects of spallation conditions. Extensive radiation damage and transmutation calculations supplement these experiments. Compatibility work includes both thermal convection and pumped flow loop tests to examine temperature gradient mass transfer. as well as fatigue and tensile tests in contact with Hg. Based on the information developed for radiation effects and compatibility with mercury, our analysis indicates that the target will meet its intended service requirements. In the past year and one half the new issue of cavitation erosion has been included in the program. Both in-beam and laboratory experiments indicate that cavitation erosion may occur in the target. The highest priority activity is now to determine whether cavitation erosion will limit target lifetime to a level below the lifetime limit set by radiation effects. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. RP Mansur, LK (reprint author), Oak Ridge Natl Lab, Met & Ceram Div, POB 2008, Oak Ridge, TN 37831 USA. NR 30 TC 18 Z9 19 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 14 EP 25 DI 10.1016/S0022-3115(03)00075-8 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900003 ER PT J AU Chen, J Bauer, GS Broome, T Carsughi, F Dai, Y Maloy, SA Roedig, M Sommer, WF Ullmaier, H AF Chen, J Bauer, GS Broome, T Carsughi, F Dai, Y Maloy, SA Roedig, M Sommer, WF Ullmaier, H TI Summary of the results from post-irradiation examination of spent targets at the FZ-Juelich SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID 800 MEV PROTONS; HIGH-ENERGY PROTON; MECHANICAL-PROPERTIES; STAINLESS-STEEL; SPALLATION ENVIRONMENT; NEUTRON-IRRADIATION; ALLOY-718; MICROSTRUCTURE; INCONEL-718; SPECTRA AB The lifetime of structural components of spallation targets (beam window, liquid metal container, return hull) is determined by the irradiation-induced changes of the mechanical properties of their materials. An extensive test program was initiated using specimens obtained from spent target components from operating spallation facilities (Los Alamos Neutron Science Center, LANSCE and the Spallation Neutron Source at Rutherford-Appleton Laboratory, ISIS). The investigated materials include a nickel-based alloy (IN 718), an austenitic stainless steel (AISI 304L), a martensitic stainless steel (DIN 1.4926) and a refractory metal (tantalum). The materials experienced 800 MeV proton irradiation to maximum fluences of > 10(25) p/m(2). The mechanical property changes were investigated by microhardness measurements, three-point bending tests and tensile tests at temperatures ranging from room temperature (RT) to 250 degreesC. Subsequent scanning electron microscopy was employed to investigate the fracture surfaces. Generally, irradiation hardening and a decrease in ductility with increasing proton fluence was observed. Nevertheless, all materials except IN 718 tested at RT, retained some ductility up to the maximum doses explored. The transmission electron microscopy investigation showed that a high density of 'black dots' and dislocation loops appeared in all materials. No effect of long-range radiation-induced segregation at grain boundaries was detected by energy dispersive X-ray investigation on AISI 304L and IN718 which failed by intergranular fracture. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Forschungszentrum Julich, Inst Festkorperforsch, Projekt ESS, D-52425 Julich, Germany. Rutherford Appleton Lab, Chilton OX11 0QX, Oxon, England. Univ Ancona, DIBIAGA, I-60131 Ancona, Italy. INFM, Unita Ancona, Ancona, Italy. Paul Scherrer Inst, Spallat Source Div, CH-5232 Villigen, Switzerland. Los Alamos Natl Lab, APT TPO, Los Alamos, NM 87545 USA. RP Chen, J (reprint author), Forschungszentrum Julich, Inst Festkorperforsch, Projekt ESS, D-52425 Julich, Germany. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 18 TC 14 Z9 14 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 56 EP 69 DI 10.1016/S0022-3115(03)00007-2 PG 14 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900006 ER PT J AU Riemer, BW Haines, JR Hunn, JD Lousteau, DC McManamy, TJ Tsai, CC AF Riemer, BW Haines, JR Hunn, JD Lousteau, DC McManamy, TJ Tsai, CC TI SNS target tests at the LANSCE-WNR in 2001 - Part I SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB Testing of mercury filled targets in an 800 MeV proton beam was conducted at the Los Alamos Neutron Science Center-Weapons Neutron Research (LANSCE-WNR) facility on two occasions in 2001. The objective for the first test campaign was to investigate if target vessel cavitation damage could occur under transient pressure conditions much like the Spallation Neutron Source (SNS) target. Such an investigation was inspired after mechanical tests conducted by a Japan Atomic Energy Research Institute (JAERI/KEK) team revealed cavitation pitting in a mercury container having comparable pressure wave intensity. The first WNR test confirmed cavitation damage with 200 proton pulses on each of two test targets. As a result, concerns arose that the lifetime of the SNS target could be seriously limited. A second test campaign was then prepared and conducted to investigate if alternate target materials or geometries could reduce or eliminate the damage. Tested materials included Stellite, Nitronic-60 as well as 316LN stainless steel (the baseline SNS target material) that was cold worked and surface hardened. Theories that the original test target geometry caused the damage were checked with tests using thick beam windows and a target with a non-axisymmetric shape. This paper describes the test program and covers target preparation, irradiation conditions, post-test decontamination and an overview of the examinations performed. J.D. Hunn covers the detailed description of the metallurgical examinations in another paper here at IWSMT-5. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37830 USA. RP Riemer, BW (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source, 701 Scarboro Rd, Oak Ridge, TN 37830 USA. OI Riemer, Bernard/0000-0002-6922-3056 NR 3 TC 23 Z9 23 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 92 EP 101 DI 10.1016/S0022-3115(03)00076-X PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900009 ER PT J AU Hunn, JD Riemer, BW Tsai, CC AF Hunn, JD Riemer, BW Tsai, CC TI SNS target tests at the LANSCE-WNR in 2001 - Part II SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB It has been observed that stopping of an 800 MeV proton pulse in liquid mercury, such as in the United States Spallation Neutron Source (SNS), leads to cavitation that can affect the mercury vessel. This paper discusses pitting that was observed on mercury container walls after 100-200 proton pulses obtained at the Los Alamos Neutron Science Center Weapons Neutron Research facility (LANSCE-WNR). It was found that the degree of cavitation-induced pitting was dependent on the geometry and composition of the container. As expected, very hard surfaces were particularly effective for resisting deformation from cavity collapse. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hunn, JD (reprint author), Oak Ridge Natl Lab, POB 2008,MS-6138, Oak Ridge, TN 37831 USA. OI Riemer, Bernard/0000-0002-6922-3056 NR 1 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 102 EP 108 DI 10.1016/S0022-3115(03)00074-6 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900010 ER PT J AU Pawel, SJ Manneschmidt, ET AF Pawel, SJ Manneschmidt, ET TI Preliminary evaluation of cavitation resistance of type 316LN stainless steel in mercury using a vibratory horn SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB Type 316LN stainless steel in a variety of conditions (annealed, cold-worked, surface-modified) was exposed to cavitation conditions in stagnant mercury using a vibratory horn. The test conditions included peak-to-peak displacement of the specimen surface of 25 mum at a frequency of 20 kHz and a mercury temperature in the range -5 to 80 degreesC. Following a brief incubation period in which little or no damage was observed, specimens of annealed 316LN exhibited increasing weight loss and surface roughening with increasing exposure times. Examination of test surfaces with the scanning electron microscope revealed primarily general/uniform wastage in all cases but, for long exposure times, a few randomly oriented 'pits' were also observed. Type 316LN that was 50% cold-worked was considerably more resistant to cavitation erosion damage than annealed material, but the surface modifications (CrN coating, metallic glass coating, laser treatment to form a diamond-like surface) provided little or no protection for the substrate. In addition, the cavitation erosion resistance of other materials - Inconel 718, Nitronic 60, and Stellite 3 - was also compared with that of 316LN for identical screening test conditions. Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. RP Pawel, SJ (reprint author), Oak Ridge Natl Lab, Met & Ceram Div, POB 2008, Oak Ridge, TN 37831 USA. NR 15 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 122 EP 131 DI 10.1016/S0022-3115(03)00020-5 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900013 ER PT J AU Marmy, P Oliver, BM AF Marmy, P Oliver, BM TI High strain fatigue properties of F82H ferritic-martensitic steel under proton irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID HYDROGEN; HELIUM; TARGET; IRON AB During the up and down cycles of a fusion reactor, the first wall is exposed concomitantly to a flux of energetic neutrons that generates radiation defects and to a thermal flux that induces thermal stresses. The resulting strains may exceed the elastic limit and induce plastic deformation in the material. A similar situation occurs in the window of a spallation liquid source target and results in the same type of damage. This particular loading has been simulated in F82H ferritic-martensitic steel, using a device allowing a fatigue test to be carried out during irradiation with 590 MeV protons. All fatigue tests were carried out in a strain controlled test at strain levels around 0.8% and at 300 degreesC. Two different signals have been used: a fully symmetrical triangle wave signal (R = -1) and a triangle ramp with 2 min tension holds. The fatigue was investigated under three different conditions: unirradiated, irradiated and post-irradiation tested, and finally in-beam tested. The main result is that the in-beam tested specimens have the lowest life as compared to the post-irradiation tested specimen and unirradiated specimen. Hydrogen is suspected to be the main contributor to the observed embrittlement. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Ecole Polytech Fed Lausanne, Assoc Euratom Confederat Suisse, Ctr Rech & Phys Plasmas Technol Fus, CH-5232 Villigen, Switzerland. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Marmy, P (reprint author), Ecole Polytech Fed Lausanne, Assoc Euratom Confederat Suisse, Ctr Rech & Phys Plasmas Technol Fus, CH-5232 Villigen, Switzerland. NR 26 TC 15 Z9 15 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 132 EP 142 DI 10.1016/S0022-3115(03)00120-0X PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900014 ER PT J AU Strizak, JP Mansur, LK AF Strizak, JP Mansur, LK TI The effect of mean stress on the fatigue behavior of 316 LN stainless steel in air and mercury SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB Design of the mercury target system components for the spallation neutron source (SNS) requires data on high- and low-cycle fatigue behavior. The research and development program in progress includes determining the effects of mercury on the fatigue behavior of type 316 LN stainless steel, the primary material of choice for the target vessel. Uniaxial, load-controlled, fully reversed tension-compression R = -1 (minimum stress/maximum stress) fatigue tests have been conducted in air and mercury at room temperature employing constant amplitude sinusoidal loading at frequencies from 0.2 to 10 Hz. Stress amplitude versus fatigue life data (S-N curves) for both air and mercury show a sharp knee at approximately I million cycles indicating a fatigue endurance limit in either air or mercury around 240 MPa. Tensile mean stress (R = 0.1) lowers the endurance limit to 160 MPa. Lower frequency and mercury environment had some impact (degradation) on fatigue life of type 316 LN stainless steel at high stress levels (i.e., stresses considerably above the apparent fatigue limit). Test results for high mean stress conditions (R = 0.3, 0.5, and 0.75) at a cyclic frequency of 10 Hz exhibited further reductions in the endurance limit. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Technol Grp, Oak Ridge, TN 37831 USA. RP Strizak, JP (reprint author), Oak Ridge Natl Lab, Technol Grp, Bethal Valley Rd,POB 2008, Oak Ridge, TN 37831 USA. NR 8 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 151 EP 156 DI 10.1016/S0022-3115(03)00121-1 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900016 ER PT J AU Tian, H Liaw, PK Strizak, JP Mansur, LK AF Tian, H Liaw, PK Strizak, JP Mansur, LK TI Effects of mercury on fatigue behavior of Type 316 LN stainless steel: application in the spallation neutron source SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SC ID PRESSURE-VESSEL STEELS; HIGH-CYCLE FATIGUE; TEMPERATURE EVOLUTION; ALLOY; SUPERALLOY; TARGET AB The high-cycle fatigue behavior of Type 316 stainless steel (SS), the prime candidate target-container material for the spallation neutron source (SNS), was investigated in air and mercury at frequencies of 0.2 and 10 Hz with a R ratio of -1. and at 10 and 700 Hz with a R ratio of 0.1. Here R equals the ratio of the applied minimum to maximum loads during fatigue experiments. A decrease in the fatigue life in mercury was observed, relative to that in air, at 0.2 Hz. Correspondingly, intergranular fracture was found on the fracture surfaces of specimens tested in mercury at 0.2 Hz, which is a typical fracture mode caused by liquid metal embrittlement (LME). Heating by mechanical working was observed during fatigue tests at 10 Hz and a R of -1, and at 700 Hz and a R of 0.1, which resulted in great increases in specimen temperatures and shorter fatigue lives for large stress amplitudes ( greater than or equal to 210 MPa), relative to those in mercury. However. in the fatigue tests at 10 and 700 Hz, the fatigue lives in air with cooling and those in mercury seemed to be comparable, indicating little influence of the mercury. Thus, both specimen self-heating and LME need to be considered in understanding fatigue behavior of Type 316 SS in air and mercury. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. RP Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. EM htian@utk.edu NR 21 TC 12 Z9 12 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 157 EP 166 DI 10.1016/S0022-3115(03)00116-8 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900017 ER PT J AU Dai, Y Foucher, Y James, MR Oliver, BM AF Dai, Y Foucher, Y James, MR Oliver, BM TI Neutronics calculation, dosimetry analysis and gas measurements of the first SINQ target irradiation experiment, STIP-I SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID HELIUM; PROTON; LANSCE AB To precisely determine the damage, helium and hydrogen production in the specimens irradiated in Swiss Spallation Neutron Source Target-3, calculations with the MCNPX code, dosimetry analysis and helium/hydrogen measurements have been performed. The MCNPX calculations agree well with the former calculations performed with the LAHET code. The preliminary analysis of dosimetry foils demonstrates that the unfolded proton and neutron spectra at limited positions are close to calculated values. In general the measured He concentrations were consistent with the calculated values. Some discrepancy between the measured and calculated values is believed due to the actual proton beam geometry being different from that used for the calculation. The hydrogen concentration measured in samples irradiated at similar to250 degreesC, only a small amount of hydrogen remains in the samples. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Paul Scherrer Inst, CH-5232 Villigen, Switzerland. EMN, Subatech, F-44307 Nantes, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Dai, Y (reprint author), Paul Scherrer Inst, CH-5232 Villigen, Switzerland. NR 12 TC 43 Z9 44 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 167 EP 175 DI 10.1016/S0022-3115(03)00099-0 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900018 ER PT J AU Gohar, Y AF Gohar, Y TI Characterization of lead-bismuth eutectic target material for accelerator driven transmuters SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB Lead-bismuth eutectic (LBE) is under consideration as a target material with high-energy protons for generating neutrons to drive actinide and fission product transmuters. A characterization has been performed to study the performance of this target material as a function of the main variables and the design selections. The characterization includes the neutron yield, the spatial energy deposition, the neutron spectrum, the beam window performance, and the target buffer requirements. The characterization has also considered high-energy deuteron particles to study the impact on the target neutronic performance. The obtained results quantify the LBE target material performance with proton or deuteron particles as a function of the target variables and selections. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Fus Power Program Technol Dev Div, Argonne, IL 60439 USA. RP Gohar, Y (reprint author), Argonne Natl Lab, Fus Power Program Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 185 EP 191 DI 10.1016/S0022-3115(03)00012-6 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900020 ER PT J AU Dai, Y Jia, XJ Farrell, K AF Dai, Y Jia, XJ Farrell, K TI Mechanical properties of modified 9Cr-1Mo (T91) irradiated at <= 300 degrees C in SINQ Target-3 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID NEUTRON-IRRADIATION; TENSILE PROPERTIES; PROTON IRRADIATION; MICROSTRUCTURE; STEELS; METALS; FUSION; ALLOYS; F82H AB Specimens of martensitic steel T91 were irradiated in the Swiss spallation neutron source (SINQ) Target-3 in a temperature range of 90-300 degreesC to displacement doses between 3 and 9.8 dpa. Tensile tests were performed at 22, 250 and 350 degreesC, and small punch (SP) tests were conducted in a temperature range of - 186 to 22 degreesC to derive the change of the ductile-brittle transition temperature (DeltaDBTT(SP)) of the steel after irradiation. The tensile test results demonstrate that the irradiation hardening increases with dose. The uniform elongation falls to less than 1%, while the total elongation is greater than 5% in all cases. All the tensile samples broke in a ductile fracture mode. In the present dose range the irradiation hardening does not saturate and increases even more rapidly at doses above about 6 dpa. The SP tests indicate that the DBTTSP of 0.25 mm thick T91 discs is about -153 degreesC for the unirradiated condition. After irradiation the DBTTSP increases significantly to -35 degreesC at 9.4 dpa, corresponding to an estimated DBTTCVN shift of 295 degreesC; and meanwhile the upper energies decrease. The DeltaDBTT(SP) has a linear dependence on helium content. Analyses of the data indicate that the radiation hardening and the occurrence of intergranular fracture mode in the higher dose SP tests are dependent on gas content. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Paul Scherrer Inst, Spallat Neutron Source Div, CH-5232 Villigen, Switzerland. Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. RP Dai, Y (reprint author), Paul Scherrer Inst, Spallat Neutron Source Div, CH-5232 Villigen, Switzerland. NR 25 TC 41 Z9 42 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 192 EP 199 DI 10.1016/S0022-3115(03)00100-4 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900021 ER PT J AU Toloczko, MB Hamilton, ML Maloy, SA AF Toloczko, MB Hamilton, ML Maloy, SA TI High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID TARGET CONTAINER MATERIALS; NEUTRON-IRRADIATION; MECHANICAL-PROPERTIES; MARTENSITIC STEELS; MICROSTRUCTURE; ACTIVATION; BEHAVIOR AB This study examines the effect of tensile test temperatures ranging from 50 to 600 degreesC on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 degreesC to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between I and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 degreesC and then increased for tensile test temperatures up to and including 500 degreesC. At 600 degreesC, the UE was observed to be less than the values at 400 and 500 degreesC. UE of the irradiated material tensile tested at 400-600 degreesC was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Toloczko, MB (reprint author), Pacific NW Natl Lab, MS P8-15,POB 999, Richland, WA 99352 USA. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 21 TC 26 Z9 28 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 200 EP 206 DI 10.1012/S0022-3115(03)00023-0 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900022 ER PT J AU Farrell, K Byun, TS AF Farrell, K Byun, TS TI Tensile properties of ferritic/martensitic steels irradiated in HFIR, and comparison with spallation irradiation data SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID NEUTRON-IRRADIATION; MECHANICAL-PROPERTIES; ALPHA-IRON; MICROSTRUCTURE; EMBRITTLEMENT; PROTON; FLUENCE; ALLOYS AB Tensile properties of four ferritic/martensitic steels, 9Cr-1MoVNb, 9Cr-1MoVNb-2Ni, 9Cr-2WV, and 9Cr-2WVTa, and two bainitic steels, 3Cr-3WV and A533B, were measured after irradiation to doses up to 1.2 dpa at temperatures in the range 60-100degreesC in the High Flux Isotope Reactor and compared with two ferritic/martensitic (F/M) steels irradiated with 800 MeV protons and spallation neutrons in the LANSCE facility at 60-164degreesC. Irradiation hardening in the steels was strong, and all of them displayed plastic instability shortly after yield for irradiations of 0.054 dpa and higher. Despite large loses in elongation, all failures occurred in a ductile manner. The dose dependencies of the increases in the yield strength with dpa were similar for all six steels, and contained a pronounced change at about 0.05 dpa. Below 0.05 dpa, the hardening exponent was 0.5-0.6, consistent with a barrier hardening mechanism. Above 0.05 dpa, the exponent was reduced to 0.1-0.2, which is speculated to be due to intervention by dislocation channeling. A trend curve for correlating changes in yield strengths of F/M steels with dose at irradiation temperatures below 160degreesC is offered. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Farrell, K (reprint author), Oak Ridge Natl Lab, Bldg 4500S,MS 6151,POB 2008, Oak Ridge, TN 37831 USA. NR 40 TC 40 Z9 40 U1 4 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 274 EP 282 DI 10.1016/S0022-3115(03)00102k-8 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900031 ER PT J AU Maloy, SA James, MR Johnson, WR Byun, TS Farrell, K Toloczko, MB AF Maloy, SA James, MR Johnson, WR Byun, TS Farrell, K Toloczko, MB TI Comparison of fission neutron and proton/spallation neutron irradiation effects on the tensile behavior of type 316 and 304 stainless steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID TARGET; ACCELERATOR; PROGRAM AB As part of the accelerator production of tritium and the spallation neutron source programs, the tensile properties of annealed 304L 316LN and 316L stainless steel have been measured after proton and spallation neutron irradiation in the target region of the Los Alamos Neutron Science Center (LANSCE) accelerator (800 MeV, 1 mA) to a maximum dose of 12 dpa at temperatures ranging from 30 to 120degreesC. In addition to the displacement damage produced from the irradiation, up to several thousand atomic parts per million (appm) of hydrogen and helium were produced in the irradiated material via spallation reactions. Results of tensile tests at temperatures from room temperature up to 164degreesC show large increases in tensile yield strength, small increases in ultimate tensile strength, reductions in strain hardening capacity and reductions in ductility (uniform elongation and strain-to-necking) with increasing irradiation dose. A comparison of these data with the large database on tensile properties of type 316 stainless steel exposed to fission neutrons and tensile tested over the same temperature range show similar trends with regard to strength changes, but significantly larger reductions in ductility with irradiation dose were observed after irradiation in the spallation environment. The much higher amounts of helium and hydrogen produced through spallation in the LANSCE spectrum, compared to those developed in fission neutron irradiation environments at equivalent doses, may contribute to degradation in ductility. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Maloy, SA (reprint author), Los Alamos Natl Lab, MS H809, Los Alamos, NM 87545 USA. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 22 TC 24 Z9 24 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 283 EP 291 DI 10.1016/S0022-3115(03)00087-4 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900032 ER PT J AU Byun, TS Farrell, K AF Byun, TS Farrell, K TI Tensile properties of Inconel 718 after low temperature neutron irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID 800 MEV PROTONS; MECHANICAL-PROPERTIES; STAINLESS-STEELS; SPALLATION ENVIRONMENT; ALLOY-718; CREEP AB Tensile properties of Inconel 718 (IN718) have been investigated after neutron irradiation to 0.0006-1.2 dpa at 60-100degreesC in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). The alloy was exposed in solution-annealed (SA) and precipitation-hardened (PH) conditions. Before irradiation, the yield strength of PH IN718 was about 1170 MPa, which was 3.7 times higher than that of SA IN718. In the SA condition, an almost threefold increase in yield strength was found at 1.2 dpa, but the alloy retained a positive strain-hardening capability and a uniform ductility of more than 20%. Comparisons showed that the strain-hardening behavior of the SA IN718 is similar to that of a SA 316LN austenitic stainless steel. In the PH condition, the IN718 displayed no radiation-induced hardening in yield strength and significant softening in ultimate tensile strength. The strain-hardening capability of the PH IN718 decreased with dose as the radiation-induced dissolution of precipitates occurred, which resulted in the onset of plastic instability at strains less than 1% after irradiation to 0.16 or 1.2 dpa. An analysis on plastic instability indicated that the loss of uniform ductility in PH IN718 was largely due to the reduction in strain-hardening rate, while in SA IN718 and SA 316LN stainless steel it resulted primarily from the increase of yield stress. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Byun, TS (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,Bldg 5500,MS-6151, Oak Ridge, TN 37831 USA. NR 23 TC 20 Z9 20 U1 1 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 292 EP 299 DI 10.1016/S0022-3115(03)00006-0 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900033 ER PT J AU Hashimoto, N Hunn, JD Byun, TS Mansur, LK AF Hashimoto, N Hunn, JD Byun, TS Mansur, LK TI Microstructural analysis of ion-irradiation-induced hardening in inconel 718 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA ID MEV PROTONS; HELIUM; RATES AB As an assessment for a possible accelerator beam line window material for the US Spallation Neutron Source (SNS) target, performance, radiation-induced hardening and microstructural evolution in Inconel 718 were investigated in both solution annealed (SA) and precipitation hardened (PH) conditions. Irradiations were carried out using 3.5 MeV Fe+, 370 keV He+ and 180 keV H+ either singly or simultaneously at 200degreesC to simulate the damage and He/H production in the SNS target vessel wall. This resulted in systematic hardening in SA Inconel and gradual net softening in the PH material. TEM microstructural analysis showed the hardening was associated with the formation of small loop and faulted loop structures. Helium-irradiated specimens included more loops and cavities than Fe. ion-irradiated specimens. Softening of the PH material was due to dissolution of the gamma'/gamma" precipitates. High doses of helium were implanted in order to study the effect of high retention of gaseous transmutation products. Simultaneous with the hardening and/or softening due to the displacement damage cascade, helium filled cavities produced additional hardening at high concentrations. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hashimoto, N (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,Bldg 4500S,MS 6136, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012 NR 14 TC 18 Z9 19 U1 0 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 300 EP 306 DI 10.1016/S0022-3115(03)00013-8 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900034 ER PT J AU Pawel, SJ Taleyarkhan, RP Felde, DK Manneschmidt, ET AF Pawel, SJ Taleyarkhan, RP Felde, DK Manneschmidt, ET TI Influence of mercury velocity on compatibility with type 316L/316LN stainless steel in a flow loop SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SOUTH CAROLINA AB Previous experiments to examine corrosion resulting from thermal gradient mass transfer of type 316L stainless steel in mercury were conducted in thermal convection loops (TCLs) with an Hg velocity of about I m/min. These tests have now been supplemented with a series of experiments designed to examine the influence of increased flow velocity and possible cavitation conditions on compatibility. In one experiment, the standard TCL design was modified to,include a reduced section in the hot leg that provided a concomitant increase in the local velocity by a factor of five. In addition, a pumped-loop experiment was operated with a flow velocity of about I m/s. Finally, a TCL was modified to include an ultrasonic transducer at the top of the hot leg in an attempt to generate cavitation conditions with corresponding extreme local velocity associated with collapsing bubbles. The results indicate that compatibility of type 316L/316LN stainless steel does not depend significantly on liquid metal velocity in the range of I m/min to I m/s. Benchtop cavitation experiments revealed susceptibility of 316L coupons to significant weight losses and increases in surface roughness as a result of 24 It exposure to 1.5 MPa pressure waves in Hg generated ultrasonically at 20 kHz. However, attempts to generate cavitation conditions on coupons inside the TCL with the ultrasonic transducer proved largely unsuccessful. Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37831 USA. RP Pawel, SJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 313 EP 324 DI 10.1016/S0022-3115(03)00021-7 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900036 ER PT J AU Pawel, SJ Manneschmidt, ET AF Pawel, SJ Manneschmidt, ET TI Corrosion of type 6061-T6 aluminum in mercury and mercury vapor SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Workshop on Spallation Materials Technology CY MAY 19-24, 2002 CL CHARLESTON, SC ID STAINLESS-STEEL AB To examine potential corrosion of aluminum maintenance equipment in environments periodically containing mercury vapor and droplets of liquid mercury, c-rings of 6061-T6 aluminum have been exposed to a series of screening tests. The tests included vapor phase exposures as well as immersion of stressed and unstressed c-rings in the as-received condition and with chemical treatments to modify the passive film. Test conditions included the temperature range 0160degreesC, times of 3-30 days and, in addition to liquid Hg, various Hg vapor environments including residual air, residual helium and condensing conditions. The results indicate 6061-T6 is quite susceptible to pitting and cracking when immersed in Hg for even a brief time, but at least one chemical treatment was shown to improve corrosion resistance under immersion conditions. Type 6061-T6 was found to be essentially immune to vapor phase corrosion for the conditions examined, with only very minor development of pits or pit precursors. Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Pawel, SJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM pawelsj@ornl.gov NR 14 TC 7 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 355 EP 364 DI 10.1016/S0022-3115(03)00022-9 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900041 ER PT J AU DiStefano, JR AF DiStefano, JR TI Discussion session summary: corrosion SO JOURNAL OF NUCLEAR MATERIALS LA English DT Editorial Material C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP DiStefano, JR (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 368 EP 368 DI 10.1016/S0022-3115(03)00124-7 PG 1 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900043 ER PT J AU Maloy, SA AF Maloy, SA TI Discussion session summary: radiation effects SO JOURNAL OF NUCLEAR MATERIALS LA English DT Editorial Material C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Maloy, SA (reprint author), Los Alamos Natl Lab, MST-8,MS-H816, Los Alamos, NM 87545 USA. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 0 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY 15 PY 2003 VL 318 BP 369 EP 370 DI 10.1016/S0022-3115(03)00125-9 PG 2 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 683UQ UT WOS:000183168900044 ER PT J AU Halasinski, TM Weisman, JL Ruiterkamp, R Lee, TJ Salama, F Head-Gordon, M AF Halasinski, TM Weisman, JL Ruiterkamp, R Lee, TJ Salama, F Head-Gordon, M TI Electronic absorption spectra of neutral perylene (C20H12), terrylene (C30H16), and quaterrylene (C40H20) and their positive and negative ions: Ne matrix-isolation spectroscopy and time-dependent density functional theory calculations SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID POLYCYCLIC AROMATIC HYDROCARBON; DIFFUSE INTERSTELLAR BANDS; CATIONS; AR; APPROXIMATION; FLUORESCENCE; NAPHTHALENE AB We present an experimental and theoretical study of an interesting series of polycyclic aromatic hydrocarbons, the oligorylenes. The absorption spectra of perylene, terrylene, and quaterrylene in neutral, cationic, and anionic charge states are obtained by matrix-isolation spectroscopy in Ne. The experimental spectra are dominated by a bright state that red shifts with growing molecular size. Excitation energies and state symmetry assignments for this state are obtained by calculations using time-dependent density functional theory methods. These calculations also provide additional information and insight into the trends in oscillator strength and excitation energy for the bright states: in particular, the oscillator strength per unit mass of carbon increases along the series. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Leiden Observ, Raymond & Beverly Sackler Lab, NL-2300 RA Leiden, Netherlands. NASA, Ames Res Ctr, Adv Supercomp Div, Moffett Field, CA 94035 USA. RP Salama, F (reprint author), NASA, Ames Res Ctr, Div Space Sci, Mail Stop 245-6, Moffett Field, CA 94035 USA. RI Lee, Timothy/K-2838-2012; Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 26 TC 102 Z9 103 U1 1 U2 33 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 MAY 15 PY 2003 VL 107 IS 19 BP 3660 EP 3669 DI 10.1021/jp027394w PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 678YH UT WOS:000182893900011 ER PT J AU Osborn, DL AF Osborn, DL TI The reaction of HCCO+O-2: Experimental evidence of prompt CO2 by time-resolved Fourier transform spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID BRANCHING RATIO; PHOTODISSOCIATION; HYDROCARBONS; INTENSITIES; TRANSITION; C2H2; O-2; OH AB The products CO and CO2 are observed experimentally for the first time in the HCCO + O-2 reaction. Both product molecules have identical appearance times and are formed simultaneously rather than sequentially. Both CO and Co-2 are produced with significant internal excitation. The product channel producing H + CO + CO2 accounts for at least 90% of the reaction products at 298 K. The results explain the observation of "prompt" CO2 in acetylene oxidation chemistry. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Osborn, DL (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9055, Livermore, CA 94551 USA. RI Osborn, David/A-2627-2009 NR 25 TC 33 Z9 33 U1 2 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 MAY 15 PY 2003 VL 107 IS 19 BP 3728 EP 3732 DI 10.1021/jp022571e PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 678YH UT WOS:000182893900020 ER PT J AU Hayes, SE Guidotti, RA Even, WR Hughes, PJ Eckert, H AF Hayes, SE Guidotti, RA Even, WR Hughes, PJ Eckert, H TI Li-7 solid-state nuclear magnetic resonance as a probe of lithium species in microporous carbon anodes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID GRAPHITE-INTERCALATION COMPOUNDS; ELECTROCHEMICAL INTERCALATION; MESOCARBON MICROBEADS; RECHARGEABLE BATTERIES; DISORDERED CARBONS; ION BATTERIES; HARD CARBON; NMR; ELECTRODE; INSERTION AB Electrochemical insertion of lithium into pyrolyzed amorphous carbons prepared from polymeric precursors of methacrylonitrile and divinylbenzene has been investigated by Li-7 variable temperature static and magic angle spinning (MAS) NMR. This method is able to characterize the chemical inventory of lithium, differentiating between reversible species that are truly inserted into the carbon and irreversible species that are lost to traps and parasitic processes. Furthermore, large chemical shift effects indicate that the structural and electronic properties of the inserted reversible lithium species are sensitively dependent on the extent of loading. At loading levels less than or equal to90% relative capacity, the trend is monotonic, whereas in more highly charged samples, two types of electrochemically relevant sites are observed, distinguishable from one another only at lower temperatures. At higher temperatures, dynamic exchange effects between them are evident on the NMR time scale. In the initially prepared state, these highly charged materials contain regular intercalated lithium sites as well as clusters of atomic lithium species dispersed in the amorphous matrix. The cluster sites are depopulated with time, a process that can be accelerated by heating. C1 Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. Sandia Natl Labs, Livermore, CA 94550 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Eveready Battery Co, Westlake, OH 44145 USA. RP Hayes, SE (reprint author), Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RI Hayes, Sophia/C-1075-2008 OI Hayes, Sophia/0000-0002-2809-6193 NR 60 TC 15 Z9 16 U1 1 U2 19 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 MAY 15 PY 2003 VL 107 IS 19 BP 3866 EP 3876 DI 10.1021/jp021772f PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 678YH UT WOS:000182893900038 ER PT J AU Truhlar, DG Garrett, BC AF Truhlar, DG Garrett, BC TI Reduced mass in the one-dimensional treatment of tunneling SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Editorial Material C1 Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Truhlar, DG (reprint author), Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA. RI Garrett, Bruce/F-8516-2011; Truhlar, Donald/G-7076-2015 OI Truhlar, Donald/0000-0002-7742-7294 NR 10 TC 8 Z9 8 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 MAY 15 PY 2003 VL 107 IS 19 BP 4006 EP 4007 DI 10.1021/jp021323f PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 678YH UT WOS:000182893900056 ER PT J AU Hurum, DC Agrios, AG Gray, KA Rajh, T Thurnauer, MC AF Hurum, DC Agrios, AG Gray, KA Rajh, T Thurnauer, MC TI Explaining the enhanced photocatalytic activity of Degussa P25 mixed-phase TiO2 using EPR SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRON-PARAMAGNETIC-RESONANCE; HETEROGENEOUS PHOTOCATALYSIS; NANOCRYSTALLINE TITANIA; SOLAR-CELLS; ANATASE; DEGRADATION; SURFACES; COLLOIDS; PURE AB Charge separation characteristics of a high-activity, mixed-phase titania photocatalyst (Degussa P25) are probed by EPR spectroscopy. While previous proposals consider rutile as a passive electron sink hindering recombination in anatase, this research details the critical and active role of rutile in TiO2 formulations. The inactivity of pure-phase rutile is due in part to rapid rates of recombination. Yet, in mixed-phase TiO2, charges produced on rutile by visible light are stabilized through electron transfer to lower energy anatase lattice trapping sites. These results suggest that within mixed-phase titania (P25) there is a morphology of nanoclusters containing atypically small rutile crystallites interwoven with anatase crystallites. The transition points between these two phases allow for rapid electron transfer from rutile to anatase. Thus, rutile acts as an antenna to extend the photoactivity into visible wavelengths and the structural arrangement of the similarly sized TiO2 crystallites creates catalytic "hot spots" at the rutile-anatase interface. C1 Northwestern Univ, Inst Environm Catalysis, Evanston, IL 60208 USA. Northwestern Univ, Dept Civil Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Gray, KA (reprint author), Northwestern Univ, Inst Environm Catalysis, Evanston, IL 60208 USA. RI Gray, Kimberly/B-6989-2009; OI Agrios, Alexander/0000-0002-6854-1220 NR 38 TC 1063 Z9 1076 U1 55 U2 523 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 MAY 15 PY 2003 VL 107 IS 19 BP 4545 EP 4549 DI 10.1021/jp0273934 PG 5 WC Chemistry, Physical SC Chemistry GA 678YF UT WOS:000182893700010 ER PT J AU Havecker, M Mayer, RW Knop-Gericke, A Bluhm, H Kleimenov, E Liskowski, A Su, D Follath, R Requejo, FG Ogletree, DF Salmeron, M Lopez-Sanchez, JA Bartley, JK Hutchings, GJ Schlogl, R AF Havecker, M Mayer, RW Knop-Gericke, A Bluhm, H Kleimenov, E Liskowski, A Su, D Follath, R Requejo, FG Ogletree, DF Salmeron, M Lopez-Sanchez, JA Bartley, JK Hutchings, GJ Schlogl, R TI In situ investigation of the nature of the active surface of a vanadyl pyrophosphate catalyst during n-butane oxidation to maleic anhydride SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID X-RAY-ABSORPTION; PHOSPHORUS OXIDE CATALYSTS; SELECTIVE OXIDATION; ALKANE OXIDATION; VPO CATALYST; IN-SITU; SPECTROSCOPY; MECHANISM; OXYGEN; TRANSFORMATION AB In situ X-ray absorption spectroscopy (XAS) and in situ X-ray photoelectron spectroscopy (XPS) have been applied to study the active surface of vanadium phosphorus oxide (VPO) catalysts in the course of the oxidation of n-butane to maleic anhydride (MA). The V L-3 near edge X-ray absorption fine structure (NEXAFS) of VPO is related to the details of the bonding between the central vanadium atom and the surrounding oxygen atoms. Reversible changes of the NEXAFS were observed when going from room temperature to the reaction conditions. These changes are interpreted as dynamic rearrangements of the VPO surface, and the structural rearrangements are related to the catalytic activity of the material that was verified by proton-transfer reaction mass spectrometry (PTR-MS). The physical origin of the variation of the NEXAFS is discussed and a tentative assignment to specific V-O bonds in the VPO structure is given. In situ XPS investigations were used to elucidate the surface electronic conductivity and to probe the ground state of the NEXAFS spectra. C1 Max Planck Gesell, Fritz Haber Inst, Dept Inorgan Chem, D-14195 Berlin, Germany. Cardiff Univ, Dept Chem, Cardiff CF10 3TB, S Glam, Wales. BESSY, D-12489 Berlin, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Havecker, M (reprint author), Max Planck Gesell, Fritz Haber Inst, Dept Inorgan Chem, Faradayweg 4-6, D-14195 Berlin, Germany. RI Requejo, Felix/O-2260-2016; lopez-sanchez, jose/E-4689-2011 OI Requejo, Felix/0000-0003-4439-864X; lopez-sanchez, jose/0000-0003-3064-0140 NR 54 TC 44 Z9 47 U1 2 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 MAY 15 PY 2003 VL 107 IS 19 BP 4587 EP 4596 DI 10.1021/jp027259j PG 10 WC Chemistry, Physical SC Chemistry GA 678YF UT WOS:000182893700016 ER PT J AU Ahluwalia, RK Doss, ED Kumar, R AF Ahluwalia, RK Doss, ED Kumar, R TI Performance of high-temperature polymer electrolyte fuel cell systems SO JOURNAL OF POWER SOURCES LA English DT Article DE high temperature membrane; fuel cell system performance; fuel processing; heat rejection; water recovery AB Performance of gasoline reformed, polymer electrolyte fuel cell (PEFC) systems for transportation with a high-temperature solid membrane capable of operating at 150-200 degreesC is discussed. Particular emphasis is placed on system layout, ease of fuel reforming, overall system efficiency, specific weight of the power system, heat rejection and water recovery. These are assessed in terms of the primary system variables, i.e. the operating pressure, reforming temperature, water-to-fuel ratio in the fuel processor, and the stack temperature. It is found that the system efficiency and water recovery are intimately affected by whether the condenser is located to operate at the system operating pressure or at close to ambient pressure. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Doss, ED (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 6 TC 26 Z9 26 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD MAY 15 PY 2003 VL 117 IS 1-2 BP 45 EP 60 DI 10.1016/S0378-7753(03)00028-4 PG 16 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 683NM UT WOS:000183155700008 ER PT J AU Lin, ZJ Stevenson, JW Khaleel, MA AF Lin, ZJ Stevenson, JW Khaleel, MA TI The effect of interconnect rib size on the fuel cell concentration polarization in planar SOFCs SO JOURNAL OF POWER SOURCES LA English DT Article DE fuel cell; concentration polarization; gas transport; rib design; analytical model ID FLOW DISTRIBUTION; TEMPERATURE; ELECTROLYTE; PERFORMANCE; MODEL AB The gas transport in the porous electrode is treated by a phenomenological approach such that the gas concentration at the three-phase boundary (TPB) region is the additive superposition of that transported from the source, i.e. the gas channels. With plausible approximations and elemental algebra, analytical expressions are obtained to estimate the effects of ribs on the concentration polarization of planar fuel cell operations. It is shown that the model can closely reproduce the experimental concentration polarization curve for small and medium current density (up to about 2 A/cm(2)), providing a simple and effective method for engineering application. The concentration polarization caused by the presence of a rib is discussed and the concentration profiles with varying rib widths are illustrated. In connection with the electrical resistance, the determination of the optimal rib width for minimizing the overall polarization is also shown. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Lab Engn Mech Grp, Richland, WA 99352 USA. RP Khaleel, MA (reprint author), Pacific NW Natl Lab, Lab Engn Mech Grp, POB 999,Mail Stop K2-18, Richland, WA 99352 USA. RI Lin, Zijing/D-4050-2009; OI khaleel, mohammad/0000-0001-7048-0749 NR 13 TC 34 Z9 34 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD MAY 15 PY 2003 VL 117 IS 1-2 BP 92 EP 97 DI 10.1016/S0378-7753(02)00726-7 PG 6 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 683NM UT WOS:000183155700012 ER PT J AU Sampath, S Jiang, X Kulkarni, A Matejicek, J Gilmore, DL Neiser, RA AF Sampath, S Jiang, X Kulkarni, A Matejicek, J Gilmore, DL Neiser, RA TI Development of process maps for plasma spray: case study for molybdenum SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE process maps; plasma spray; thermal spray; molybdenum; residual stress ID MICROSTRUCTURE DEVELOPMENT; SPLAT FORMATION; DEPOSITION; COATINGS; SURFACE AB A schematic representation referred to as "process maps" examines the role of process variables on the properties of plasma-sprayed coatings. Process maps have been developed for air plasma spraying of molybdenum. Experimental work was done to investigate the importance of such spray parameters as gun current, primary gas flow, auxiliary gas flow, and powder carrier gas flow. In-flight particle temperatures and velocities were measured and diameters estimated in various areas of the spray plume. Empirical models were developed relating the input parameters to the in-flight particle characteristics. Molybdenum splats and coatings were produced at three distinct process conditions identified from the first-order process map experiments. In addition, substrate surface temperature during deposition was treated as a variable. Within the tested range, modulus, hardness and thermal conductivity increases with particle velocity, while oxygen content and porosity decreases. Increasing substrate deposition temperature resulted in dramatic improvement in coating thermal conductivity and modulus, while simultaneously increasing coating oxide content. Indentation reveals improved fracture resistance for the coatings prepared at higher substrate temperature. Residual stress was significantly affected by substrate temperature, although not to a great extent by particle conditions within the investigated parameter range. Coatings prepared at high substrate temperature with high-energy particles suffered considerably less damage in a wear test. The mechanisms behind these changes are discussed within the context relational maps, which have been proposed. (C) 2002 Elsevier Science B.V. All rights reserved. C1 SUNY Stony Brook, Ctr Thermal Spray Res, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Sandia Natl Labs, Thermal Spray Res Lab, Albuquerque, NM 87185 USA. RP Sampath, S (reprint author), SUNY Stony Brook, Ctr Thermal Spray Res, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RI Matejicek, Jiri/G-2313-2014 OI Matejicek, Jiri/0000-0001-8454-2808 NR 26 TC 63 Z9 66 U1 1 U2 8 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 MAY 15 PY 2003 VL 348 IS 1-2 BP 54 EP 66 AR PII S0921-5093(02)00642-1 DI 10.1016/S0921-5093(02)00642-1 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 654QZ UT WOS:000181508700009 ER PT J AU Mohrenweiser, HW Wilson, DM Jones, IM AF Mohrenweiser, HW Wilson, DM Jones, IM TI Challenges and complexities in estimating both the functional impact and the disease risk associated with the extensive genetic variation in human DNA repair genes SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Review DE challenges and complexities; disease risk; human DNA repair genes ID BASE-EXCISION-REPAIR; SINGLE-NUCLEOTIDE POLYMORPHISMS; PURIFIED HUMAN PROTEINS; DOUBLE-STRAND BREAKS; IONIZING-RADIATION SENSITIVITY; ACID SUBSTITUTION VARIANTS; 41 CANDIDATE GENES; MISMATCH REPAIR; MAMMALIAN-CELLS; CANCER RISK AB Individual risk and the population incidence of disease result from the interaction of genetic susceptibility and exposure. DNA repair is an example of a cellular process where genetic variation in families with extreme predisposition is documented to be associated with high disease likelihood, including syndromes of premature aging and cancer. Although the identification and characterization of new genes or variants in cancer families continues to be important, the focus of this paper is the current status of efforts to define the impact of polymorphic amino acid substitutions in DNA repair genes on individual and population cancer risk. There is increasing evidence that mild reductions in DNA repair capacity, assumed to be the consequence of common genetic variation, affect cancer predisposition. The extensive variation being found in the coding regions of DNA repair genes and the large number of genes in each of the major repair pathways results in complex genotypes with potential to impact cancer risk in the general population. The implications of this complexity for molecular epidemiology studies, as well as concepts that may make these challenges more manageable, are discussed. The concepts include both experimental and computational approaches that could be employed to develop predictors of disease susceptibility based on DNA repair genotype, focusing initially on studies to assess functional impact on individual proteins and pathways and then on molecular epidemiology studies to assess exposure-dependent health risk. In closing, we raise some of the non-technical challenges to the utilization of the full richness of the genetic variation to reduce disease occurrence and ultimately improve health care. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. NIA, Lab Mol Gerontol, GRC, NIH, Baltimore, MD 21224 USA. RP Mohrenweiser, HW (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-448,7000 East Ave, Livermore, CA 94551 USA. EM mohrenweiser1@llnl.gov FU NCI NIH HHS [1 U-1 CA83180-03] NR 149 TC 155 Z9 160 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAY 15 PY 2003 VL 526 IS 1-2 BP 93 EP 125 DI 10.1016/S0027-5107(03)00049-6 PG 33 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 676HX UT WOS:000182746200011 PM 12714187 ER PT J AU Poyneer, LA Troy, M Macintosh, B Gavel, DT AF Poyneer, LA Troy, M Macintosh, B Gavel, DT TI Experimental validation of Fourier-transform wave-front reconstruction at the Palomar Observatory SO OPTICS LETTERS LA English DT Article AB Wave-front reconstruction with use of the Fourier transform has been validated through theory and simulation. This method provides a dramatic reduction in computational costs for large adaptive (AO) systems. Because such a reconstructor can be expressed as a matrix, it can be used as an alternative in a matrix-based AO control system. This was done with the Palomar Observatory AO system on the 200-in. Hale telescope. Results of these tests indicate that Fourier-transform wave-front, reconstruction works in a real system. For both bright and dim stars, a Hudgin-geometry Fourier-transform method produced performance comparable to that of the Palomar Adaptive Optics least squares. The Fried-geometry method had a noticeable Strehl ratio performance degradation of 0.043 in the K band (165-nm rms wave-front error added in quadrature) on a dim star. (C) 2003 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Poyneer, LA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Tippie, Abbie/A-1106-2007 NR 7 TC 21 Z9 21 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD MAY 15 PY 2003 VL 28 IS 10 BP 798 EP 800 DI 10.1364/OL.28.000798 PG 3 WC Optics SC Optics GA 674JW UT WOS:000182634500012 PM 12779150 ER PT J AU Markos, P Soukoulis, CM AF Markos, P Soukoulis, CM TI Absorption losses in periodic arrays of thin metallic wires SO OPTICS LETTERS LA English DT Article ID LOW-FREQUENCY PLASMONS; LEFT-HANDED MATERIALS; EFFECTIVE PERMITTIVITY; METAMATERIALS; TRANSMISSION; PERMEABILITY AB We analyze the transmission and reflection of electromagnetic waves calculated from transfer matrix simulations of periodic arrangements of thin metallic wires. The effective permittivity and the absorption of the arrangements of wires are determined. Their dependence on the wire thickness and the conductance of the metallic wires is studied. The cutoff frequency, or effective plasma frequency, is obtained and compared with analytical predictions. It is shown that the periodic arrangement of wires exhibits a frequency region in which the real part of the permittivity is negative while its imaginary part is very small. This behavior is seen for wires with thickness as small as 17 mum with a lattice constant of 3.33 mm. (C) 2003 Optical Society of America. C1 Res Ctr Crete, Iraklion 71110, Crete, Greece. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Markos, P (reprint author), Res Ctr Crete, Iraklion 71110, Crete, Greece. EM markos@savba.sk RI Soukoulis, Costas/A-5295-2008 NR 16 TC 19 Z9 19 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 EI 1539-4794 J9 OPT LETT JI Opt. Lett. PD MAY 15 PY 2003 VL 28 IS 10 BP 846 EP 848 DI 10.1364/OL.28.000846 PG 3 WC Optics SC Optics GA 674JW UT WOS:000182634500028 PM 12779166 ER PT J AU Chugunov, AI Baiko, DA Yakovlev, DG De Witt, HE Slattery, WL AF Chugunov, AI Baiko, DA Yakovlev, DG De Witt, HE Slattery, WL TI Pair distribution of ions in Coulomb crystals SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article DE Coulomb crystals; correlations ID ONE-COMPONENT PLASMA; WHITE-DWARFS; SIMULATIONS; TRANSPORT; EQUATION; MATTER; RATES; STATE AB The pair distribution function g(r) of ions in body-centered-cubic and face-centered-cubic Coulomb crystals is calculated using the harmonic-lattice (HL) approximation in a wide temperature range, from the high-temperature classical regime (T >> (h) over bar omega(p), omega(p), is the ion plasma frequency) to the low-temperature quantum regime (T<<(h) over bar omega(p),). The radial pair distribution function g(r) is calculated by averaging g(r) over orientations of r. In the classical limit, g(r) is also obtained from extensive Monte Carlo (MC) simulations. MC and HL results are shown to be in good agreement. With decreasing temperature T, the correlation peaks of g(r) and g(r) become narrower and finally freeze at T << (h) over bar omega(p) being solely determined by zero-point ion vibrations. (C) 2003 Elsevier Science B.V. All rights reserved. C1 AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Yakovlev, DG (reprint author), AF Ioffe Phys Tech Inst, Politekhnicheskaya 26, St Petersburg 194021, Russia. EM yak@astro.ioffe.rssi.ru RI Chugunov, Andrey/E-2061-2014 NR 18 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 EI 1873-2119 J9 PHYSICA A JI Physica A PD MAY 15 PY 2003 VL 323 BP 413 EP 427 DI 10.1016/S0378-4371(02)02027-7 PG 15 WC Physics, Multidisciplinary SC Physics GA 684UA UT WOS:000183223900028 ER PT J AU Avdeev, M Jorgensen, JD Ribeiro, RA Bud'ko, SL Canfield, PC AF Avdeev, M Jorgensen, JD Ribeiro, RA Bud'ko, SL Canfield, PC TI Crystal chemistry of carbon-substituted MgB2 SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE MgB2; doping of MgB2; composition; crystal structure ID SUPERCONDUCTIVITY AB Neutron powder diffraction has been used to characterize a sample of C-substituted MgB2 synthesized from Mg and B4C (with isotopically enriched B-11). The sample is multiphase, with the major phase [73.4(l) wt%] being Mg(B1-xCx)(2) with x = 0.10(2). Minor phases include MgB2C2, Mg, and MgO. The major Mg(B1-xCx)(2) phase displays diffraction peak widths as sharp as for pure MgB2, indicating good C homogeneity. There is no evidence for ordering of the substituted C atoms or distortion of the host structure other than contraction of the a axis and slight expansion of the c axis. The observed changes in lattice parameters vs. C concentration provide a means for estimating the C concentration in other Mg(B1-xCx)(2) samples. The reduction in T-c resulting from 10% C substitution is much larger than previously reported, suggesting that previous reports of the C concentration in Mg(B1-xCx)(2) are overestimated. The Mg site occupancy is determined to be 0.990(4) which is consistent with full Mg occupancy. Given these results, the stoichiometry Mg(B0.9C0.1)(2) should be used by future attempts (band structural or otherwise) to explain (i) the dramatic suppression of T-c (T-c approximate to 22 K) and (ii) the persistence of the two-superconducting-gap feature in the specific heat data. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Iowa State Univ Sci & Technol, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. RP Jorgensen, JD (reprint author), Argonne Natl Lab, Div Mat Sci, Bldg 223, Argonne, IL 60439 USA. RI Ribeiro, Raquel/B-9041-2012; Avdeev, Maxim/A-5625-2008; Canfield, Paul/H-2698-2014 OI Ribeiro, Raquel/0000-0001-6075-1701; Avdeev, Maxim/0000-0003-2366-5809; NR 17 TC 159 Z9 163 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAY 15 PY 2003 VL 387 IS 3-4 BP 301 EP 306 DI 10.1016/S0921-4534(03)00722-6 PG 6 WC Physics, Applied SC Physics GA 669AE UT WOS:000182329100001 ER PT J AU Li, M Ma, B Koritala, RE Fisher, BL Venkataraman, K Maroni, VA Vlasko-Vlasov, V Berghuis, P Welp, U Gray, KE Balachandran, U AF Li, M Ma, B Koritala, RE Fisher, BL Venkataraman, K Maroni, VA Vlasko-Vlasov, V Berghuis, P Welp, U Gray, KE Balachandran, U TI Pulsed laser deposition of c-axis untilted YBCO films on c-axis tilted ISD MgO-buffered metallic substrates SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE YBCO-coated conductor; biaxial texture; ISD; pulsed laser deposition ID CRITICAL-CURRENT-DENSITY; COATED CONDUCTORS; YBA2CU3O7-X FILMS; THIN-FILMS; SUPERCONDUCTORS AB Biaxially textured MgO template layer was deposited on nontextured metal substrates by inclined-substrate deposition (ISD) at a deposition rate of 24-600 nm/min. c-axis untilted YBa2Cu3O7-x (YBCO) films were deposited on these MgO-buffered substrates by pulsed laser deposition. The crystalline structures of the YBCO films and MgO layers were examined by X-ray pole figure analysis, X-ray phi-scans, and chi-scans. A tilt angle of 33degrees of the MgO[0 0 1] with respect to the substrate normal and c-axis untilted YBCO films were observed, respectively. Good biaxial texture of these films with full-width-at-half-maximum values of 13.8degrees and 10.6degrees for the phi-scans of YBCO(1 0 3) and MgO(2 2 0), respectively, were obtained. Morphologies were examined by scanning electron microscopy, which revealed a unique roof-tile feature and columnar grain growth for the ISD MgO layer. Raman spectroscopy and magneto-optical image technique were also used to evaluate the quality of the YBCO film. An angular dependence of J(c) on the direction of an applied magnetic field confirmed the c-axis untilted orientation of the YBCO films. T-c = 90 K with sharp transition and J(c) = 3.0 x 10degrees A/cm(2) at 77 K in zero field were obtained on 0.4-mum-thick YBCO films. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Li, M (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Koritala, Rachel/F-1774-2011; Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 17 TC 7 Z9 7 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAY 15 PY 2003 VL 387 IS 3-4 BP 373 EP 381 DI 10.1016/S0921-4534(02)02332-8 PG 9 WC Physics, Applied SC Physics GA 669AE UT WOS:000182329100010 ER PT J AU Tolle, CR McJunkin, TR Rohrbaugh, DT LaViolette, RA AF Tolle, CR McJunkin, TR Rohrbaugh, DT LaViolette, RA TI Lacunarity definition for ramified data sets based on optimal cover SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE fractals; pattern recognition; ramified data; mathematical methods in physics AB Lacunarity is a measure of how data fills space. It complements fractal dimension, which measures how much space is filled. This paper discusses the limitations of the standard gliding box algorithm for calculating lacunarity, which leads to a re-examination of what lacunarity is meant to describe. Two new lacunarity measures for ramified data sets are then presented that more directly measure the gaps in a ramified data set. These measures are rigorously defined. An algorithm for estimating the new lacunarity measure, using Fuzzy-C means clustering algorithm, is developed. The lacunarity estimation algorithm is used to analyze two- and three-dimensional Cantor dusts. Applications for these measures include biological modeling and target detection within ramified data sets. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Dept Ind & Mat Technol, Idaho Falls, ID 83415 USA. RP Tolle, CR (reprint author), Idaho Natl Engn & Environm Lab, Dept Ind & Mat Technol, Idaho Falls, ID 83415 USA. RI McJunkin, Timothy/G-8385-2011 OI McJunkin, Timothy/0000-0002-4987-9170 NR 23 TC 20 Z9 24 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD MAY 15 PY 2003 VL 179 IS 3-4 BP 129 EP 152 DI 10.1016/S0167-2789(03)00029-0 PG 24 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 706LB UT WOS:000184454200001 ER PT J AU Croft, M Caliebe, W Woo, H Tyson, TA Sills, D Hor, YS Cheong, SW Kiryukhin, V Oh, SJ AF Croft, M Caliebe, W Woo, H Tyson, TA Sills, D Hor, YS Cheong, SW Kiryukhin, V Oh, SJ TI Metal-insulator transition in CuIr2S4: XAS results on the electronic structure SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; SPECTROSCOPY; SYSTEM; OXIDES; VO2 AB S K and Ir L-3 x-ray absorption measurements across the temperature-induced metal (M) to insulator (I) transition in CuIr2S4 are presented. Dramatic S K-edge changes reflect the Ir d-electronic state redistribution across this transition. These changes, along with a detailed consideration of the I-phase structure, motivate a model in which the I-phase stabilization involves an interplay of charge and d-orbital orientation ordering along Ir chains, a quadrupling of the Ir-chain repeat unit, and correlated dimer spin-singlet formation. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Seoul Natl Univ, Ctr Strongly Correlated Mat Res, Seoul 151742, South Korea. RP Croft, M (reprint author), Rutgers State Univ, Dept Phys & Astron, POB 849, Piscataway, NJ 08854 USA. NR 22 TC 37 Z9 38 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 MAY 15 PY 2003 VL 67 IS 20 AR 201102 DI 10.1103/PhysRevB.67.201102 PG 4 WC Physics, Condensed Matter SC Physics GA 689GL UT WOS:000183483200002 ER PT J AU Hanbicki, AT Rous, PJ Plummer, EW AF Hanbicki, AT Rous, PJ Plummer, EW TI Static and dynamic lattice changes induced by hydrogen adsorption on NiAl(110) SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-ENERGY-LOSS; METAL-SURFACES; QUANTUM DELOCALIZATION; RELIABILITY FACTORS; PHONON-DISPERSION; SOLID-SURFACES; WORK FUNCTION; CHEMISORPTION; MOTION; LEED AB Static and dynamic changes induced by adsorption of atomic hydrogen on the NiAl(110) lattice at 130 K have been examined as a function of adsorbate coverage. Adsorbed hydrogen exists in three distinct phases. At low coverages the hydrogen is itinerant because of quantum tunneling between sites and exhibits no observable vibrational modes. Between 0.4 and 0.6 ML, substrate mediated interactions produce an ordered superstructure with c(2x2) symmetry, and at higher coverages, hydrogen exists as a disordered lattice gas. This picture of how hydrogen interacts with NiAl(110) is developed from our data and compared to current theoretical predictions. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA. Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hanbicki, AT (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM Hanbicki@anvil.nrl.navy.mil NR 58 TC 5 Z9 5 U1 2 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 2003 VL 67 IS 20 AR 205405 DI 10.1103/PhysRevB.67.205405 PG 13 WC Physics, Condensed Matter SC Physics GA 689GL UT WOS:000183483200078 ER PT J AU Karbowiak, M Mech, A Drozdzynski, J Edelstein, NM AF Karbowiak, M Mech, A Drozdzynski, J Edelstein, NM TI Crystal-field analysis, upconversion, and excited-state dynamics for (U4+,U3+): Ba2YCl7 single crystals SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION-SPECTRUM ANALYSIS; OPTICAL-ABSORPTION; UP-CONVERSION; ACTINIDE TETRAFLUORIDES; PARAMETRIC ANALYSIS; EMISSION-SPECTRA; U3+ IONS; LUMINESCENCE; SPECTROSCOPY; CM3+ AB Single crystals of (U4+,U3+):Ba2YCl7 were grown by the Bridgman-Stockbarger technique. The U4+ and U3+ ions substitute for Y3+ and have C-1 site symmetry in Ba2YCl7. Sixty energy levels of U4+ were assigned to 40 000 cm(-1) from absorption, excitation, and luminescence spectra, which encompasses all but the S-1(0) multiplet. A crystal-field analysis was performed by fitting 8 atomic and 19 crystal-field parameters to the experimental Stark levels. The values obtained from the fit had a standard deviation of 36.6 cm(-1) and agreed with those calculated from the angular overlap model. Efficient luminescence was observed at 7 K from the(4)G(7/2) and F-4(9/2) levels of the U3+ ions and from the D-1(2) and I-1(6) of the U4+ ions with decay times of 0.5, 0.55, 9.2, and 4.3 mus, respectively. For the U4+ ions, a very strong anti-Stokes emission was observed due to energy-transfer processes. The emission of the U3+ ions is strongly quenched by temperature in contrast to that of the U4+ ions for which emission was observed even at room temperature. Energy transfer between the U3+ and U4+ ions has been shown to occur in the (U4+,U3+) doped Ba2YCl7. C1 Univ Wroclaw, Dept Chem, PL-50383 Wroclaw, Poland. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Karbowiak, M (reprint author), Univ Wroclaw, Dept Chem, Ul F Joliot Curie 14, PL-50383 Wroclaw, Poland. NR 60 TC 10 Z9 10 U1 4 U2 10 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 MAY 15 PY 2003 VL 67 IS 19 AR 195108 DI 10.1103/PhysRevB.67.195108 PG 17 WC Physics, Condensed Matter SC Physics GA 687MF UT WOS:000183380000030 ER PT J AU Li, JB Wang, LW AF Li, JB Wang, LW TI First principles calculations of ZnS : Te energy levels SO PHYSICAL REVIEW B LA English DT Article ID ZNSE1-XTEX SOLID-SOLUTIONS; ISOELECTRONIC IMPURITIES; GALLIUM PHOSPHIDE; II-VI; ELECTRONIC-STRUCTURE; PRESSURE BEHAVIOR; BINDING-ENERGIES; QUANTUM DOTS; BAND OFFSETS; THIN-FILMS AB A comprehensive density-functional calculation for the ZnS:Te isoelectronic impurity state is presented. We deploy a charge patching method that enables us to calculate systems containing thousands of atoms. We found that the impurity state is only weakly localized, and previous calculations using 64-atom cells were severely unconverged. Our calculated impurity binding energy agrees with experimental photoluminescence excitation spectrum. We have analyzed the impurity wave function in both real space and the reciprocal space, and in terms of the host bulk valence bands. We have also calculated the Stokes shifts and Jahn-Teller effects. We found small Stokes shift compared to the experimental results, which might indicate the limitations of the current method. We also calculated the Te-n clusters and their impurity states. We found six (counting spin) bound states inside the band gap of ZnS for all 1less than or equal tonless than or equal to4. We obtained pressure coefficients for Te-n, all close to the value of bulk ZnS. This is consistent with the fact that the impurity states of Te-n consist almost entirely of the bulk valence bands of ZnS. Finally, we have calculated the effects of spin-orbit coupling for the impurity state eigenenergies. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Li, JB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 50 TC 14 Z9 14 U1 1 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 MAY 15 PY 2003 VL 67 IS 20 AR 205319 DI 10.1103/PhysRevB.67.205319 PG 11 WC Physics, Condensed Matter SC Physics GA 689GL UT WOS:000183483200060 ER PT J AU Boyda, EK Ganguli, S Horava, P Varadarajan, U AF Boyda, EK Ganguli, S Horava, P Varadarajan, U TI Holographic protection of chronology in universes of the Godel type SO PHYSICAL REVIEW D LA English DT Article ID ROTATING BLACK-HOLES; CAUSALITY VIOLATION; SPACE-TIMES AB We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on the "phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of "microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T dual to pp waves, and use this fact to generate new Godel-like solutions of string and M theory by T dualizing known supersymmetric pp-wave solutions. C1 Univ Calif Berkeley, Berkeley Ctr Theoret Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Boyda, EK (reprint author), Univ Calif Berkeley, Berkeley Ctr Theoret Phys, Berkeley, CA 94720 USA. NR 46 TC 97 Z9 97 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 MAY 15 PY 2003 VL 67 IS 10 AR 106003 DI 10.1103/PhysRevD.67.106003 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 687LB UT WOS:000183377200098 ER PT J AU Fragile, PC Anninos, P AF Fragile, PC Anninos, P TI Hydrodynamic stability of cosmological quark-hadron phase transitions SO PHYSICAL REVIEW D LA English DT Article ID BUBBLE-GROWTH; EARLY UNIVERSE; DROPLET DECAY; ELECTROWEAK; INSTABILITY; QCD AB Recent results from linear perturbation theory suggest that first-order cosmological quark-hadron phase transitions occurring as deflagrations may be "borderline" unstable, and those occurring as detonations may give rise to growing modes behind the interface boundary. However, since nonlinear effects can play important roles in the development of perturbations, unstable behavior cannot be asserted entirely by linear analysis, and the uncertainty of these recent studies is compounded further by nonlinearities in the hydrodynamics and self-interaction fields. In this paper we investigate the growth of perturbations and the stability of quark-hadron phase transitions in the early Universe by solving numerically the fully nonlinear relativistic hydrodynamics equations coupled to a scalar field with a quartic self-interaction potential regulating the transitions. We consider single, perturbed, phase transitions propagating either by detonation or deflagration, as well as multiple phase and shock front interactions in 1 + 2 dimensional spacetimes. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Fragile, PC (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 17 TC 6 Z9 6 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 MAY 15 PY 2003 VL 67 IS 10 AR 103010 DI 10.1103/PhysRevD.67.103010 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 687LB UT WOS:000183377200020 ER PT J AU Camera, F Bracco, A Nanal, V Carpenter, MP Della Vedova, F Leoni, S Million, B Mantovani, S Pignanelli, M Wieland, O Back, BB Heinz, AM Janssens, RVF Jenkins, D Khoo, TL Kondev, FG Lauritsen, T Lister, CJ McClintock, B Mitsuoka, S Moore, EF Seweryniak, D Siemssen, RH Van Swol, RJ Hofman, D Thoennessen, M Eisenman, K Heckman, P Seitz, J Varner, R Halbert, M Dioszegi, I Lopez-Martens, A AF Camera, F Bracco, A Nanal, V Carpenter, MP Della Vedova, F Leoni, S Million, B Mantovani, S Pignanelli, M Wieland, O Back, BB Heinz, AM Janssens, RVF Jenkins, D Khoo, TL Kondev, FG Lauritsen, T Lister, CJ McClintock, B Mitsuoka, S Moore, EF Seweryniak, D Siemssen, RH Van Swol, RJ Hofman, D Thoennessen, M Eisenman, K Heckman, P Seitz, J Varner, R Halbert, M Dioszegi, I Lopez-Martens, A TI Radiative fusion from very symmetric reactions: the giant dipole resonance in the Au-179 nucleus SO PHYSICS LETTERS B LA English DT Article ID HOT NUCLEI; DECAY; WIDTH AB The spectra of high-energy gamma rays emitted by the Giant Dipole Resonance (GDR) built on moderately excited states associated with the evaporation of 0, 1 and 2 nucleons were measured in the Zr-90 + Y-89 symmetric fusion reaction. The radiative fusion data suggest statistical emission from the compound nucleus. In addition, the analysis of the high-energy gamma-ray spectra associated with the different evaporation channels at the present temperature of 0.7 MeV and spin range 15-20 h show a fairly narrow width of 5.0 +/- 0.35 MeV. This value is smaller than what would be expected in a nucleus where shell effects do not play a role. (C) 2003 Published by Elsevier Science B.V. C1 Univ Milan, Milan, Italy. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Argonne Natl Lab, Argonne, IL 60459 USA. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Univ Illinois, Chicago, IL 60607 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys Astron, E Lansing, MI 48824 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. CNRS, IN2P3, CSNSM, F-91405 Orsay, France. RP Camera, F (reprint author), Univ Milan, Milan, Italy. RI Wieland, Oliver/G-1784-2011; Heinz, Andreas/E-3191-2014; Carpenter, Michael/E-4287-2015; OI Carpenter, Michael/0000-0002-3237-5734; Camera, Franco/0000-0003-1731-4834 NR 16 TC 25 Z9 25 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 15 PY 2003 VL 560 IS 3-4 BP 155 EP 160 DI 10.1016/S0370-2693(03)00403-9 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 676AY UT WOS:000182730800002 ER PT J AU Schramm, S AF Schramm, S TI Nuclear and neutron star radii SO PHYSICS LETTERS B LA English DT Article ID CHIRAL SU(3) MODEL; EQUATION; PB-208; MATTER AB We investigate the correlation between nuclear neutron radii and the radius of neutron stars. We use a well-established hadronic SU(3) model based on chiral symmetry that naturally includes nonlinear vector meson and scalar meson-vector meson couplings. The relative strengths of the couplings modify the nuclear isospin-dependent interactions. We study the dependence of nuclear and neutron star radii on the coupling strengths. The relevance of the results for parity-violating electron-nucleus scattering is discussed. (C) 2003 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Schramm, S (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 TC 18 Z9 18 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 MAY 15 PY 2003 VL 560 IS 3-4 BP 164 EP 170 DI 10.1016/S0370-2693(03)00408-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 676AY UT WOS:000182730800004 ER PT J AU Archuleta, RJ Liu, PC Steidl, JH Bonilla, LF Lavallee, D Heuze, F AF Archuleta, RJ Liu, PC Steidl, JH Bonilla, LF Lavallee, D Heuze, F TI Finite-fault site-specific acceleration time histories that include nonlinear soil response SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article; Proceedings Paper CT International Workshop on the Quantitative Prediction of Strong-motion and the Physics of Earthquake Source CY OCT 23-25, 2000 CL TSUKUBA, JAPAN DE earthquake; site response; nonlinearity; accelerogram ID EMPIRICAL GREENS-FUNCTIONS; STRONG-GROUND MOTION; 1979 IMPERIAL-VALLEY; NORTHRIDGE EARTHQUAKE; SOURCE PARAMETERS; WAVE PROPAGATION; MODEL; SEISMOGRAMS; VALIDATION; PREDICTION AB To estimate the broadband strong ground motion one might expect at a given site we develop a method that includes heterogeneous slip on a finite-fault, full wave propagation with high frequencies, and site-specific material properties with nonlinear soil response. The faulting is simulated as a stochastic process with the spatial variation of the key parameters determined by probability distribution functions. The wave propagation from source to site is accounted for by using small earthquake recordings as empirical Green's functions (EGF). This accounts for the regional effects of scattering, attenuation and structure while providing the basis for a broadband (0.5-10 Hz) time history. Because we are interested in sites where the ground motion is expected to be severe, we have included nonlinear wave propagation through the soil. The material properties of the soil column have been determined from laboratory tests, borehole logs and confirmed through seismological modeling of weak motion. We have computed 240 three-component acceleration time histories to represent the range of ground motion one might expect from a M 6.8 earthquake for a site that is located 10 km above the hanging wall of blind thrust (7.1 km closest distance). Based on the suite of time histories we computed a S.D. of 0.45 (natural log units) for the acceleration response spectra in the passband 0.5-10 Hz. The total S.D. (modeling plus parameterization) is 0.6 in natural log units. The mean acceleration response spectrum is near the median 10% in 50-year probabilistic seismic hazard analysis (PSHA) spectrum for the site; the 84% spectrum of the simulations is closer to the 5% in 50 years median spectrum. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Geol Sci, Inst Crustal Studies, Santa Barbara, CA 93106 USA. BERSSIN, IRSN, DPRE, SERGD,Ctr Etudes Nulc, F-92262 Fontenay Aux Roses, France. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Archuleta, RJ (reprint author), Univ Calif Santa Barbara, Dept Geol Sci, Inst Crustal Studies, Santa Barbara, CA 93106 USA. RI Steidl, Jamison/H-6292-2012; Bonilla, Luis Fabian/K-5092-2012 NR 60 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD MAY 15 PY 2003 VL 137 IS 1-4 BP 153 EP 181 DI 10.1016/S0031-9201(03)00013-X PG 29 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 693DN UT WOS:000183700300011 ER PT J AU Burr, TL Gattiker, JR Gerrish, PJ AF Burr, TL Gattiker, JR Gerrish, PJ TI An investigation of error sources and their impact in estimating the time to the most recent ancestor of spatially and temporally distributed HIV sequences SO STATISTICS IN MEDICINE LA English DT Article DE time to ancestor; evolutionary models; confidence interval; error sources ID HUMAN-IMMUNODEFICIENCY-VIRUS; DNA; EVOLUTION; ORIGIN AB This is an investigation of significant error sources and their impact in estimating the time to the most recent common ancestor (MRCA) of spatially and temporally distributed human immunodeficiency virus (HIV) sequences. We simulate an HIV epidemic under a range of assumptions with known time to the MRCA (t(MRCA))- We then apply a range of baseline (known) evolutionary models to generate sequence data. We next estimate or assume one of several misspecified models and use the chosen model to estimate the time to the MRCA. Random effects and the extent of model misspecification determine the magnitude of error sources that could include: neglected heterogeneity in substitution rates across lineages and DNA sites; uncertainty in HIV isolation times; uncertain magnitude and type of population subdivision; uncertain impacts of host/viral transmission dynamics, and unavoidable model estimation errors. Our results suggest that confidence intervals will rarely have the nominal coverage probability for t(MRCA). Neglected effects lead to errors that are unaccounted for in most analyses, resulting in optimistically narrow confidence intervals (CI). Using real HIV sequences having approximately known isolation times and locations, we present possible confidence intervals for several sets of assumptions. In general, we cannot be certain how much to broaden a stated confidence interval for tMRCA. However, we describe the impact of candidate error sources on CI width. We also determine which error sources have the most impact on Cl width and demonstrate that the standard bootstrap method will underestimate the Cl width. Copyright (C) 2003 John Wiley Sons, Ltd. C1 Los Alamos Natl Lab, Safeguards Syst Grp, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Theoret Biol Grp, Los Alamos, NM 87545 USA. RP Burr, TL (reprint author), Los Alamos Natl Lab, Safeguards Syst Grp, Mail Stop E541, Los Alamos, NM 87545 USA. OI Gerrish, Philip/0000-0001-6393-0553 NR 31 TC 1 Z9 1 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0277-6715 J9 STAT MED JI Stat. Med. PD MAY 15 PY 2003 VL 22 IS 9 BP 1495 EP 1516 DI 10.1002/sim.1508 PG 22 WC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Medicine, Research & Experimental; Statistics & Probability SC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Research & Experimental Medicine; Mathematics GA 674UQ UT WOS:000182655100012 PM 12704612 ER PT J AU Gong, XY Nie, ZM Qian, MX Liu, J Pederson, LA Hobbs, DT McDuffie, NG AF Gong, XY Nie, ZM Qian, MX Liu, J Pederson, LA Hobbs, DT McDuffie, NG TI Gibbsite to boehmite transformation in strongly caustic and nitrate environments SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID THERMAL-DECOMPOSITION; KINETICS AB The transformation of gibbsite to boehmite in strongly caustic solutions was studied using quantitative X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy techniques. Under hydrothermal conditions, we identified two transformation mechanisms: (1) dehydration and in situ nucleation and (2) dissolution and nucleation. If the reaction container was not completely sealed, dehydration of gibbsite followed by in situ nucleation of boehmite was the preferred mechanism. Boehmite produced fibrous boehmite particles within the amorphous matrix of the decomposed gibbsite particles, which exhibited a poorly crystalline structure and a smaller size than the initial gibbsite particles. In a closed environment, the preferred mechanism was the dissolution of gibbsite along (001) planes. The final boehmite particles were not morphologically related to the initial gibbsite particles and could be many times larger than the gibbsite particles. C1 Westinghouse Savannah River Co, Columbia, SC 29208 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hobbs, DT (reprint author), Westinghouse Savannah River Co, Columbia, SC 29208 USA. NR 18 TC 18 Z9 18 U1 4 U2 14 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 MAY 14 PY 2003 VL 42 IS 10 BP 2163 EP 2170 DI 10.1021/ie020837y PG 8 WC Engineering, Chemical SC Engineering GA 677ZG UT WOS:000182839400015 ER PT J AU Austin, DE Grimm, RL Manning, HLK Bailey, CL Farnsworth, JE Ahrens, TJ Beauchamp, JL AF Austin, DE Grimm, RL Manning, HLK Bailey, CL Farnsworth, JE Ahrens, TJ Beauchamp, JL TI Hypervelocity microparticle impact studies using a novel cosmic dust mass spectrometer SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID IONIZATION; PARTICLES; ACCELERATOR; IONS AB [1] Micron-sized iron and copper particles accelerated to 2-20 km/s in a 2 MV van de Graaff electrostatic accelerator were used to test the performance of our recently developed cosmic dust mass spectrometer. This compact in situ dust analyzer, known as the Dustbuster, is designed to determine the elemental composition of cosmic dust particles through impact ionization and subsequent time-of-flight mass spectrometry. Results from 750 laboratory impacts show high mass resolution, typically 150-350 (m/Deltam) for projectile components and 300-600 for the target material (tantalum). Peaks corresponding to H, C, O, Na, and K ions are also observed, consistent with previous microparticle impact experiments. Field-induced emission of electrons immediately before impact is a possible cause of ion formation from species with high ionization potentials. The high mass resolution, large sensitive target area, and small size make the Dustbuster an ideal instrument for inclusion on a spacecraft payload. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Concordia Coll, Dept Phys, Moorhead, MN 56562 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. RP Austin, DE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jlbchamp@caltech.edu NR 27 TC 12 Z9 12 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD MAY 14 PY 2003 VL 108 IS E5 AR 5038 DI 10.1029/2002JE001947 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 682RU UT WOS:000183106800002 ER PT J AU Frolov, AM Bailey, DH AF Frolov, AM Bailey, DH TI Highly accurate evaluation of the few-body auxiliary functions and four-body integrals SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID BOUND-STATE CALCULATIONS; ATOMIC INTEGRALS; WAVE-FUNCTIONS; ANALYTIC EVALUATION; SYSTEMS AB Analytical formulae suitable for numerical calculations of the second-and third-order auxiliary functions A(2)(k, m, a, b) and A(3)(k, l, m, a, b, c) are presented. These formulae can directly be used in highly accurate calculations of the A(2)(k, m, a, b) and A(3)(k, F, m, a, b, c) functions. In turn, the highly accurate auxiliary functions of the second and third order are used to compute various four-body integrals, fourth-order auxiliary functions A(4)(k, l, m, n, a, b, c, d) and so-called general four-body integrals. The A(2)(k, m, a, b) and A(3)(k, l, m, a, b, c) functions can be used to solve a large number of four-, five- and many-body problems from atomic, nuclear and molecular physics. C1 Queens Univ, Dept Chem, Kingston, ON K7L 3N6, Canada. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Frolov, AM (reprint author), Queens Univ, Dept Chem, Kingston, ON K7L 3N6, Canada. NR 15 TC 17 Z9 17 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAY 14 PY 2003 VL 36 IS 9 BP 1857 EP 1867 AR PII S0953-4075(03)58918-0 DI 10.1088/0953-4075/36/9/315 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 698RN UT WOS:000184012700016 ER PT J AU Austin, RH Xie, AH van der Meer, L Shinn, M Neil, G AF Austin, RH Xie, AH van der Meer, L Shinn, M Neil, G TI Self-trapped states in proteins? SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Conference on Nanophysics in Life Sciences CY JUN 21-22, 2002 CL COPENHAGEN, DENMARK ID MODES AB We show here that the temperature dependence of the amide I band of myoglobin shows evidence for a low-lying S-elf-trapped state at 6.15 mum. We have conducted a careful set of picosecond pump-probe experiments providing results as a function of temperature. and wavelength and show that this low-lying state has a 30 ps lifetime at 50 K, much longer than the relaxation time of the main amide I band at 50 K. Fits of the temperature dependence of thermal occupation of this state yield the result that it lies 280 K below the main amide I band. Since the gap energy of this state is approximately equal to room temperature, this self-trapped state can act as a transient store of vibrational energy at physiological temperatures in biomolecules and can help to direct the path of energy flow in a biomolecule under biological conditions. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. FOM, Inst Plasma Phys, Nieuwegein, Netherlands. Jefferson Lab, Newport News, VA 23606 USA. RP Austin, RH (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NR 5 TC 14 Z9 15 U1 1 U2 2 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 MAY 14 PY 2003 VL 15 IS 18 BP S1693 EP S1698 AR PII S0953-8984(03)55806-4 DI 10.1088/0953-8984/15/18/303 PG 6 WC Physics, Condensed Matter SC Physics GA 683DU UT WOS:000183133200005 ER PT J AU Garnweitner, G Smarsly, B Assink, R Ruland, W Bond, E Brinker, CJ AF Garnweitner, G Smarsly, B Assink, R Ruland, W Bond, E Brinker, CJ TI Self-assembly of an environmentally responsive polymer/silica nanocomposite SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID N-ISOPROPYLACRYLAMIDE; COPOLYMERS; GELS C1 Univ New Mexico, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Marburg, D-35032 Marburg, Germany. RP Brinker, CJ (reprint author), Univ New Mexico, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. RI Smarsly, Bernd/G-8514-2011; OI Garnweitner, Georg/0000-0002-7499-4947 NR 9 TC 39 Z9 40 U1 2 U2 34 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 MAY 14 PY 2003 VL 125 IS 19 BP 5626 EP 5627 DI 10.1021/ja0342648 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 676TX UT WOS:000182769400022 PM 12733889 ER PT J AU Kemsley, JN Wasinger, EC Datta, S Mitic, N Acharya, T Hedman, B Caradonna, JP Hodgson, KO Solomon, EI AF Kemsley, JN Wasinger, EC Datta, S Mitic, N Acharya, T Hedman, B Caradonna, JP Hodgson, KO Solomon, EI TI Spectroscopic and kinetic studies of PKU-inducing mutants of phenylalanine hydroxylase: Arg158Gln and Glu280Lys SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY-ABSORPTION; AMINO-ACID HYDROXYLASES; NONHEME IRON ENZYMES; SUBSTRATE ACTIVATION; TYROSINE-HYDROXYLASE; CIRCULAR-DICHROISM; CRYSTAL-STRUCTURE; CATALYTIC DOMAIN; ACTIVE-SITE; ELECTRONIC-STRUCTURE AB Phenylalanine hydroxylase (PAH) is a tetrahydrobiopterin-dependent, nonheme iron enzyme that catalyzes the hydroxylation of L-Phe to L-Tyr in the rate-limiting step of phenylalanine catabolism. This reaction is tightly coupled in the wild-type enzyme to oxidation of the tetrahydropterin cofactor. Dysfunction of PAH activity in humans leads to the disease phenylketonuria (PKU). We have investigated two PKU-inducing mutants, Arg158Gln and Glu280Lys, using kinetic methods, magnetic circular dichrosim (MCD) spectroscopy, and X-ray absorption spectroscopy (XAS). Analysis of the products produced by the mutant enzymes shows that although both oxidize pterin at more than twice the rate of wild-type enzyme, these reactions are only similar to20% coupled to production of L-Tyr. Previous MCD and XAS studies had demonstrated that the resting Fe-II site is six-coordinate in the wild-type enzyme and converts to a five-coordinate site when both L-Phe and reduced pterin are present in the active site. Although the Arg158Gln mutant forms the five-coordinate site when both cosubstrates are bound, the Fe-II site of the GIu280Lys mutant remains six-coordinate. These results provide insight into the PAH reaction and disease mechanism at a molecular level, indicating that the first step of the mechanism is formation of a peroxy-pterin species, which subsequently reacts with the Fe-II site if the pterin is properly oriented for formation of an Fe-OO-pterin bridge and an open coordination position is available on the Fe-II. C1 Boston Univ, Dept Chem, Boston, MA 02215 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Yale Univ, Dept Chem, New Haven, CT 06520 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. RP Hedman, B (reprint author), Boston Univ, Dept Chem, 590 Commonwealth Ave, Boston, MA 02215 USA. OI Mitic, Natasa/0000-0003-4595-4150 FU NCRR NIH HHS [RR-01209]; NIGMS NIH HHS [GM61208, GM40392] NR 62 TC 20 Z9 20 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 14 PY 2003 VL 125 IS 19 BP 5677 EP 5686 DI 10.1021/ja029106f PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 676TX UT WOS:000182769400039 PM 12733906 ER PT J AU Toulokhonova, IS Stringfellow, TC Ivanov, SA Masunov, A West, R AF Toulokhonova, IS Stringfellow, TC Ivanov, SA Masunov, A West, R TI A disilapentalene and a stable diradical from the reaction of a dilithiosilole with a dichlorocyclopropene SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SILOLE DIANIONS; PARAMETERS; GERMOLE; ANALOGS; SILICON; ANIONS; SYSTEM AB The reaction of 1,1-dilithio-2,3,4,5-tetraphenylsilole (1) with 1,1-dichloro-2,3-diphenylcyclopropene (2) leads to the novel 1,4-disila-1,4-dihydropentalene (4), as well as an exceptionally stable diradical for which the structure 3 is suggested. The diradical is unreactive toward water, methanol, and chloroform; upon heating it transforms into 4. Structure 3 for the paramagnetic species is proposed on the basis of EPR data and theoretical calculations. The trans-trans isomer of diradical 3 was calculated to be more stable than its cis-cis isomer. The strong and stable EPR signal in the reaction mixture is probably due to the trans-trans isomer of diradical 3 in the triplet state. A reaction scheme describing the formation of 3 and 4 is presented. C1 Univ Wisconsin, Dept Chem, Organosilicon Res Ctr, Madison, WI 53706 USA. Los Alamos Natl Lab, Theoret Div T12, Los Alamos, NM 87544 USA. RP West, R (reprint author), Univ Wisconsin, Dept Chem, Organosilicon Res Ctr, Madison, WI 53706 USA. EM west@chem.wisc.edu RI Ivanov, Sergei/B-5505-2011; Masunov, Artem/A-1745-2011 OI Masunov, Artem/0000-0003-4924-3380 NR 27 TC 11 Z9 11 U1 0 U2 1 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 MAY 14 PY 2003 VL 125 IS 19 BP 5767 EP 5773 DI 10.1021/ja020763h PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 676TX UT WOS:000182769400050 PM 12733917 ER PT J AU Byl, O Kondratyuk, P Forth, ST FitzGerald, SA Chen, L Johnson, JK Yates, JT AF Byl, O Kondratyuk, P Forth, ST FitzGerald, SA Chen, L Johnson, JK Yates, JT TI Adsorption of CF4 on the internal and external surfaces of opened single-walled carbon nanotubes: A vibrational spectroscopy study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR SIMULATION; INFRARED-SPECTRA; ADSORBED ATOMS; RAMAN-SPECTRA; BUNDLES; GASES; ICE; ZEOLITES; SOLIDS; PHASE AB Infrared spectroscopy has been used to make the first experimental discrimination between molecules bound by physisorption on the exterior surface of carbon single-walled nanotubes (SWNTs) and molecules bound in the interior. In addition, the selective displacement of the internally bound molecules has been observed as a second adsorbate is added. SWNTs were opened by oxidative treatment with O-3 at room temperature, followed by heating in a vacuum to 873 K. It was found that, at 133 K and 0.033 Torr, CF4 adsorbs on closed SWNTs, exhibiting its nu(3) asymmetric stretching mode at 1267 cm(-1) (red shift relative to the gas phase, 15 cm(-1)). Adsorption on the nanotube exterior is accompanied by adsorption in the interior in the case of opened SWNTs. Internally bound CF4 exhibits its nu(3) mode at 1247 cm-1 (red shift relative to the gas phase, 35 cm(-1)). It was shown that, at 133 K, Xe preferentially displaces internally bound CF4 species, and this counterintuitive observation was confirmed by molecular simulations. The confinement of CF4 inside (10,10) single-walled carbon nanotubes does not result in the production of lattice modes that are observed in large 3D ensembles of CF4. C1 Univ Pittsburgh, Dept Chem, Ctr Surface Sci, Pittsburgh, PA 15260 USA. Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Oberlin Coll, Dept Phys, Oberlin, OH 44074 USA. RP Yates, JT (reprint author), Univ Pittsburgh, Dept Chem, Ctr Surface Sci, Pittsburgh, PA 15260 USA. RI Chen, Liang/B-3418-2008; Johnson, Karl/E-9733-2013 OI Johnson, Karl/0000-0002-3608-8003 NR 53 TC 90 Z9 91 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 MAY 14 PY 2003 VL 125 IS 19 BP 5889 EP 5896 DI 10.1021/ja020949g PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 676TX UT WOS:000182769400063 PM 12733930 ER PT J AU Marin, TW Jonah, CD Bartels, DM AF Marin, TW Jonah, CD Bartels, DM TI Reaction of OH center dot radicals with H-2 in sub-critical water (vol 371, pg 144, 2002) SO CHEMICAL PHYSICS LETTERS LA English DT Correction C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Bartels, DM (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Marin, Timothy/E-3446-2010 NR 1 TC 4 Z9 4 U1 0 U2 0 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 MAY 13 PY 2003 VL 373 IS 1-2 BP 228 EP 228 DI 10.1016/S0009-2614(03)00561-X PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 679ZN UT WOS:000182952000036 ER PT J AU Nishimura, K Matsumoto, H Kojima, H Gary, SP AF Nishimura, K Matsumoto, H Kojima, H Gary, SP TI Particle simulations of re-formation at collisionless perpendicular shocks: Coherent behavior of reflected ions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE collisionless shocks; shock reformation; shock potential; full particle simulation ID NONSTATIONARITY AB [1] The properties of reformation in perpendicular collisionless shocks are investigated by means of a one-dimensional particle-in-cell simulation. Reformation is associated with ion reflection at the shock ramp and subsequent ion gyromotion in the upstream region. However, if ions are reflected continuously at the ramp, why does the shock reform intermittently at sufficiently high Mach number? The simulations show that the shock potential changes dramatically through the re-formation cycle, so that it is this potential variation which leads to the intermittent response of the shock. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Kyoto Univ, Radio Sci Ctr Space & Atmosphere, Kyoto 6110011, Japan. RP Nishimura, K (reprint author), Los Alamos Natl Lab, NIS-1,MS D466, Los Alamos, NM 87545 USA. NR 10 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 13 PY 2003 VL 108 IS A5 AR 1182 DI 10.1029/2002JA009671 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 682TK UT WOS:000183108300006 ER PT J AU Arleth, L Bauer, R Ogendal, LH Egelhaaf, SU Schurtenberger, P Pedersen, JS AF Arleth, L Bauer, R Ogendal, LH Egelhaaf, SU Schurtenberger, P Pedersen, JS TI Growth behavior of mixed wormlike micelles: a small-angle scattering study of the lecithin-bile salt system SO LANGMUIR LA English DT Article ID BINARY SURFACTANT MIXTURES; DYNAMIC LIGHT-SCATTERING; DODECYL-SULFATE MICELLES; POLYMER-LIKE MICELLES; NEUTRON-SCATTERING; AQUEOUS-SOLUTIONS; REVERSE MICELLES; FLEXIBILITY; VESICLES; PHASE AB Aqueous mixtures of egg-yolk lecithin and the bile salt glycochenodeoxycholic acid sodium salt are studied using small-angle neutron scattering. Upon dilution, the shape and size of the aggregates change dramatically. This is due to very different critical micellar concentrations and spontaneous curvatures of lecithin and bile salt. At high concentrations, cylindrical micelles with a length of a few hundred angstroms are formed. As the samples are diluted, the length of the micelles first decreases and then increases by a factor of 3, their flexibility becomes noticeable, and the micelles can be described as semiflexible cylindrical micelles, also known as wormlike micelles. We have developed a mathematical model for the scattering of the wormlike micelles, which takes into account the intermicellar interaction effects. By the simultaneous fitting of the scattering data from a range of concentrations, the concentration-dependent growth law of the micelles can be parametrized. The obtained growth law of the mixed micelles is compared to the growth laws observed in simple micellar systems. C1 Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Riso Natl Lab, Danish Polymer Ctr, DK-4000 Roskilde, Denmark. Royal Vet & Agr Univ, Dept Math & Phys, DK-1870 Frederiksberg, Denmark. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Fribourg, Dept Phys, CH-1700 Fribourg, Switzerland. Aarhus Univ, Dept Chem, DK-8000 Aarhus C, Denmark. RP Arleth, L (reprint author), Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Mail Stop H805, Los Alamos, NM 87545 USA. RI Pedersen, Jan/A-8346-2008; Schurtenberger, Peter/K-1777-2013; Arleth, Lise/M-4705-2014; Ogendal, Lars/M-4644-2014 OI Pedersen, Jan/0000-0002-7768-0206; Schurtenberger, Peter/0000-0002-2790-8831; Arleth, Lise/0000-0002-4694-4299; Ogendal, Lars/0000-0003-0609-3669 NR 47 TC 35 Z9 35 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 13 PY 2003 VL 19 IS 10 BP 4096 EP 4104 DI 10.1012/la026808+ PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 676ZB UT WOS:000182781500008 ER PT J AU Lee, B Bao, LL Im, HJ Dai, S Hagaman, EW Lin, JS AF Lee, B Bao, LL Im, HJ Dai, S Hagaman, EW Lin, JS TI Synthesis and characterization of organic-inorganic hybrid mesoporous anion-exchange resins for perrhenate (ReO4-) anion adsorption SO LANGMUIR LA English DT Article ID NUCLEAR WASTE TREATMENT; CHANNEL WALLS; AMERICIUM SEPARATIONS; SILICA; ORGANOSILICAS; GEL; POLYSILSESQUIOXANES; FRAMEWORKS; MONOLAYERS; SORPTION AB Organic-inorganic hybrid mesoporous anion-exchange resins based on either pure silica or organosilica support materials were prepared and tested for the adsorption of perrhenate (ReO4-) anions in aqueous solutions. The prepared samples were characterized using nitrogen adsorption-desorption measurements, Fourier transform infrared spectroscopy, Raman spectroscopy, small-angle X-ray scattering, Si-29 cross-polarization/magic-angle-spinning nuclear magnetic resonance, and scanning transmission electron microscopy. Among the prepared samples, the hybrid mesoporous anion-exchange resins functionalized with N-((trimethoxysilyl)propyl)-N,N,N-tri-n-butylammonium ions showed higher affinities for perrhenate ions than did the resins functionalized with N-((trimethoxysilyl)propyl)-N,N,N-trimethylammonium ions. The enhancement by the bulky ammonium functional ligand is consistent with Hofmeister selectivity. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Dai, S (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 37 TC 58 Z9 59 U1 3 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 13 PY 2003 VL 19 IS 10 BP 4246 EP 4252 DI 10.1021/la026960b PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 676ZB UT WOS:000182781500027 ER PT J AU Zhu, J Konya, Z Puntes, VF Kiricsi, I Miao, CX Ager, JW Alivisatos, AP Somorjai, GA AF Zhu, J Konya, Z Puntes, VF Kiricsi, I Miao, CX Ager, JW Alivisatos, AP Somorjai, GA TI Encapsulation of metal (Au, Ag, Pt) nanoparticles into the mesoporous SBA-15 structure SO LANGMUIR LA English DT Article ID MOLECULAR-SIEVES; SILICA; COPOLYMER; TRIBLOCK; SHAPE AB Mesoporous silica was synthesized in the presence of metal (Au, Pt, and Ag) nanoparticles in the 2-20 rim, range. Sample characterization was performed by X-ray diffraction and electron microscopy, The metal nanoparticles in the 2-10 nm range were successfully incorporated into the ordered mesoporous SBA-15 structures; 20 am particles, whose diameter is larger than the SBA-15 pore size, could not be inserted. In the case of 5 and 10 nm diameter nanoparticles, regardless of which metal, the mesopore channels expanded in order to accommodate the metal particles. By using mixtures of metal nanoparticles of two different sizes, it was found that the inclusion and the resultant pore size were controlled by the larger size metal particles. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Szeged, Dept Appl & Environm Chem, H-6720 Szeged, Hungary. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Puntes, Victor/F-8407-2013; Konya, Zoltan/C-2492-2009; Alivisatos , Paul /N-8863-2015; OI Puntes, Victor/0000-0001-8996-9499; Konya, Zoltan/0000-0002-9406-8596; Alivisatos , Paul /0000-0001-6895-9048; Ager, Joel/0000-0001-9334-9751 NR 18 TC 133 Z9 135 U1 3 U2 83 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 13 PY 2003 VL 19 IS 10 BP 4396 EP 4401 DI 10.1021/la0207421 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 676ZB UT WOS:000182781500047 ER PT J AU Mackinnon, AJ Patel, PK Price, DW Hicks, D Romagnani, L Borghesi, M AF Mackinnon, AJ Patel, PK Price, DW Hicks, D Romagnani, L Borghesi, M TI Proton moire fringes for diagnosing electromagnetic fields in opaque materials and plasmas SO APPLIED PHYSICS LETTERS LA English DT Article ID ION-ACCELERATION; ELECTRON-DENSITY; LASER; TRANSPORT; DRIVEN; SOLIDS; BEAMS AB High contrast proton moire fringes have been obtained in a laser-produced proton beam. Moire u fringes with modulation of 20%-30% were observed in protons with energies in the range of 4 - 7 MeV. Monte Carlo simulations with simple test fields showed that shifts in the moire u fringes can be used to give quantitative information on the strength of transient electromagnetic fields inside plasmas and materials that are opaque to conventional probing methods. (C) 2003 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Queens Univ Belfast, Dept Phys, Belfast, Antrim, North Ireland. RP Mackinnon, AJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM e001654@poptop.llnl.gov RI Patel, Pravesh/E-1400-2011; Borghesi, Marco/K-2974-2012; Hicks, Damien/B-5042-2015; MacKinnon, Andrew/P-7239-2014 OI Hicks, Damien/0000-0001-8322-9983; MacKinnon, Andrew/0000-0002-4380-2906 NR 26 TC 14 Z9 15 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 12 PY 2003 VL 82 IS 19 BP 3188 EP 3190 DI 10.1063/1.1569416 PG 3 WC Physics, Applied SC Physics GA 675VV UT WOS:000182717900015 ER PT J AU Kucheyev, SO Demos, SG AF Kucheyev, SO Demos, SG TI Optical defects produced in fused silica during laser-induced breakdown SO APPLIED PHYSICS LETTERS LA English DT Article ID VITREOUS SILICA; FEMTOSECOND LASER; CENTERS; DAMAGE; RAMAN; IRRADIATION; PULSES; GROWTH; SIO2 AB Fused silica irradiated with similar to3-ns 1064-, 355-, and 266-nm laser pulses as well as with similar to120-fs 825-nm pulses is studied by a combination of photoluminescence (PL) and Raman scattering spectroscopies. Results show that, for laser fluences above the laser-induced breakdown threshold, in all the cases studied, irradiation results in the formation of four defect-related PL bands centered on similar to1.9 (655), 2.2 (565), 2.7 (460), and 4.3 eV (290 nm). Bands centered on 1.9, 2.7, and 4.3 eV are attributed to nonbridging oxygen hole centers (1.9 eV) and oxygen-deficiency defects (2.7 and 4.3 eV). However, defects giving rise to a broad band at; 2.2 eV are unknown. For all the laser-modified samples studied, Raman spectroscopy reveals a dramatic increase in the intensity of D-1 and D-2 lines, associated with in-phase breathing motions of oxygen atoms in puckered four- and planar three-membered ring structures, respectively. This indicates laser-induced material densification. Based on these results, we discuss physical processes occurring during the catastrophic laser-induced material breakdown, leading to material densification and the formation of point defects. (C) 2003 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kucheyev, SO (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 17 TC 71 Z9 72 U1 2 U2 23 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 MAY 12 PY 2003 VL 82 IS 19 BP 3230 EP 3232 DI 10.1063/1.1573364 PG 3 WC Physics, Applied SC Physics GA 675VV UT WOS:000182717900029 ER PT J AU Kim, J Ren, F Baca, AG Pearton, SJ AF Kim, J Ren, F Baca, AG Pearton, SJ TI Thermal stability of WSix and W Schottky contacts on n-GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID CURRENT-VOLTAGE CHARACTERISTICS; BARRIER HEIGHT; P-GAN; OHMIC CONTACTS; METAL CONTACTS; DIODES; TEMPERATURES; MECHANISM; TRANSPORT; PD/GAN AB WSix Schottky contacts on GaN are found to exhibit improved thermal stability compared to pure W contacts. While the W contacts degrade for anneal temperatures greater than or equal to500 degreesC through reaction with the GaN to form beta- W2N, the WSix contacts show a stable Schottky barrier height of similar to0.5 eV as obtained from I-V measurements up to temperatures >600 degreesC. The reverse leakage current in both types of diodes is considerably higher than predicted from thermionic emission and image-force-induced barrier height lowering. The reverse current density was found to vary approximately as V-B(0.5) (V-B is the reverse bias) and suggests the presence of additional current transport mechanism in both types of diodes. (C) 2003 American Institute of Physics. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Kim, J (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Kim, Jihyun/F-6940-2013 NR 30 TC 17 Z9 19 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 12 PY 2003 VL 82 IS 19 BP 3263 EP 3265 DI 10.1063/1.1576506 PG 3 WC Physics, Applied SC Physics GA 675VV UT WOS:000182717900040 ER PT J AU Muck, M Welzel, C Clarke, J AF Muck, M Welzel, C Clarke, J TI Superconducting quantum interference device amplifiers at gigahertz frequencies SO APPLIED PHYSICS LETTERS LA English DT Article ID DC SQUID; NOISE AB A series of five dc superconducting quantum interference devices (SQUIDs) have been operated as microstrip amplifiers at frequencies ranging from 2.2 to 7.4 GHz. In these devices, the signal is connected between the SQUID washer and coil, which acts as a microstrip resonator. The gain measured at 4.2 K ranged from 12+/-1 to 6+/-1 dB. The noise temperature of three devices at 4.2 K in the frequency range 2.2-4 GHz was between 1 and 2 K, and the saturation temperature was between 150 and 250 K. Applications of these devices include readout for axion detectors, and intermediate-frequency amplifiers for superconductor-insulator-superconductor and hot-electron bolometer mixers. (C) 2003 American Institute of Physics. C1 Univ Giessen, Inst Appl Phys, D-35392 Giessen, Germany. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Muck, M (reprint author), Univ Giessen, Inst Appl Phys, Heinrich Buff Ring 16, D-35392 Giessen, Germany. NR 14 TC 28 Z9 28 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 12 PY 2003 VL 82 IS 19 BP 3266 EP 3268 DI 10.1063/1.1572970 PG 3 WC Physics, Applied SC Physics GA 675VV UT WOS:000182717900041 ER PT J AU Schroer, CG Kuhlmann, M Gunzler, TF Lengeler, B Richwin, M Griesebock, B Lutzenkirchen-Hecht, D Frahm, R Ziegler, E Mashayekhi, A Haeffner, DR Grunwaldt, JD Baiker, A AF Schroer, CG Kuhlmann, M Gunzler, TF Lengeler, B Richwin, M Griesebock, B Lutzenkirchen-Hecht, D Frahm, R Ziegler, E Mashayekhi, A Haeffner, DR Grunwaldt, JD Baiker, A TI Mapping the chemical states of an element inside a sample using tomographic x-ray absorption spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID FLUORESCENCE XAFS; PIEZO-QEXAFS; SPECIMENS; CATALYSTS; LENSES; RANGE AB Hard x-ray absorption spectroscopy is combined with scanning microtomography to reconstruct full near-edge spectra of an elemental species at each location on an arbitrary virtual section through a sample. These spectra reveal the local concentrations of different chemical compounds of the absorbing element inside the sample and give insight into the oxidation state, the local atomic structure, and the local projected free density of states. The method is implemented by combining a quick scanning monochromator and data acquisition system with a scanning microprobe setup based on refractive x-ray lenses. (C) 2003 American Institute of Physics. C1 Univ Aachen, Inst Phys 2, D-52056 Aachen, Germany. Berg Univ Gesamthsch Wuppertal, Inst Mat Sci, D-42097 Wuppertal, Germany. Berg Univ Gesamthsch Wuppertal, Dept Phys, D-42097 Wuppertal, Germany. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. ETH Honggerberg, Swiss Fed Inst Technol, Inst Chem & Bioengn, CH-8093 Zurich, Switzerland. RP Schroer, CG (reprint author), Univ Aachen, Inst Phys 2, D-52056 Aachen, Germany. RI Grunwaldt, Jan-Dierk /L-9246-2013 OI Grunwaldt, Jan-Dierk /0000-0003-3606-0956 NR 20 TC 74 Z9 74 U1 2 U2 10 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 MAY 12 PY 2003 VL 82 IS 19 BP 3360 EP 3362 DI 10.1063/1.1573352 PG 3 WC Physics, Applied SC Physics GA 675VV UT WOS:000182717900073 ER PT J AU Landa, A Soderlind, P AF Landa, A Soderlind, P TI Stability of delta-Pu alloys from first-principles theory SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE delta-Pu; Pu-alloys; magnetism ID CALCULATED LATTICE-RELAXATION; ELECTRONIC-STRUCTURE; PHASE-TRANSITIONS; ACTINIDE METALS; BRILLOUIN-ZONE; PRESSURE PHASE; SPECIAL POINTS; AIRY GAS; PLUTONIUM; APPROXIMATION AB It has been proposed [Phys. Rev. B 66 (2002) 205109] that delta-Pu is stabilized at higher temperatures by magnetic interactions driving a disordered magnetic state. At lower temperatures, however, the magnetic moments are expected to align in an antiferromagnetic fashion which has been shown to destabilize delta-Pu mechanically. Consequently, delta-Pu is unstable below about 600 K but can be stabilized at lower temperatures when alloyed with a small amount of a suitable 'delta-Pu stabilizer'. Here we explain this stabilizing effect in terms of the balance between ordered and disordered magnetism and how this balance is offset by the addition of an alloying component. For this purpose we have applied density functional theory (DFT), implemented in the Korringa-Kohn-Rostocker (KKR) method within the Green's function formalism. The effect of magnetic moment disorder as well as compositional disorder was treated by means of the coherent potential approximation (CPA) implemented, in the former case, in conjunction with the disordered local moment (DLM) model. These calculations show that an alloy component larger than delta-Pu has a stabilizing effect, whereas a magnetic component that is smaller has a strongly destabilizing effect on delta-Pu. The ordered Pu3Al, Pu3Ga, Pu3In, and Pu3Tl compounds (in the Cu3Au structure) are all found to have negative heat of formation with calculated density close to experimental data. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Landa, A (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 54 TC 16 Z9 16 U1 0 U2 12 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 MAY 12 PY 2003 VL 354 IS 1-2 BP 99 EP 103 DI 10.1016/S0925-8388(03)00050-1 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 678RG UT WOS:000182879800021 ER PT J AU Chekanov, S Krakauer, D Loizides, JH Magill, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Antonioli, P Anzivino, G Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Chiarini, M Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Nemoz, C Palmonari, F Pesci, A Sartorelli, G Garcia, YZ Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Crittenden, J 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 Namsoo, T Robins, S Rodrigues, E Wing, M Ayad, R Capua, M Iannotti, L Mastroberardino, A Schioppa, M Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Ning, Y Paganis, S Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Stopa, P Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Kowal, M Kowalski, T Przybycien, M Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W 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, F 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, ALP Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Raach, H Bell, M Bussey, PJ Doyle, AT Glasman, C Hamilton, J Hanlon, S Lupi, A Saxon, DH Skillicorn, IO Gialas, I Bodmann, B Carli, T Holm, U Klimek, K Krumnack, N Lohrmann, E Milite, M Salehi, S Stonjek, S Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R 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 Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Gliga, S Lainesse, S Padhi, S Stairs, DG Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V 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 Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grzelak, G Patel, S Rigby, M 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 Barberis, E Heusch, C Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC 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 Kaji, H Kitamura, S Matsuzawa, K Nishimura, T Patel, S Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Lamberti, L Maselli, S Monaco, V Peroni, CR Ferrero, MI Sacchi, R Solano, A Staiano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Jones, TW Lightwood, MS 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 Krakauer, D Loizides, JH Magill, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Antonioli, P Anzivino, G Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Chiarini, M Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Nemoz, C Palmonari, F Pesci, A Sartorelli, G Garcia, YZ Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Crittenden, J 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 Namsoo, T Robins, S Rodrigues, E Wing, M Ayad, R Capua, M Iannotti, L Mastroberardino, A Schioppa, M Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Ning, Y Paganis, S Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Stopa, P Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Kowal, M Kowalski, T Przybycien, M Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W 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, F 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, ALP Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Raach, H Bell, M Bussey, PJ Doyle, AT Glasman, C Hamilton, J Hanlon, S Lupi, A Saxon, DH Skillicorn, IO Gialas, I Bodmann, B Carli, T Holm, U Klimek, K Krumnack, N Lohrmann, E Milite, M Salehi, S Stonjek, S Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R 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 Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Gliga, S Lainesse, S Padhi, S Stairs, DG Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V 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 Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grzelak, G Patel, S Rigby, M 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 Barberis, E Heusch, C Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC 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 Kaji, H Kitamura, S Matsuzawa, K Nishimura, T Patel, S Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Lamberti, L Maselli, S Monaco, V Peroni, CR Ferrero, MI Sacchi, R Solano, A Staiano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Jones, TW Lightwood, MS 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 CA ZEUS Collaboration TI Leading proton production in e(+) p collisions at HERA SO NUCLEAR PHYSICS B LA English DT Article ID DEEP-INELASTIC SCATTERING; LEPTON-NUCLEON SCATTERING; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; STRUCTURE-FUNCTION F-2; MONTE-CARLO GENERATOR; DIFFRACTIVE PHOTOPRODUCTION; NEUTRON-PRODUCTION; FRACTURE FUNCTIONS; CROSS-SECTIONS AB Events with a final-state proton carrying a large fraction of the proton beam momentum, x(L) > 0.6, and the square of the transverse momentum p(T)(2) < 0.5 GeV2 T, have been studied in e(+)p collisions with the ZEUS detector at HERA. Data with different photon virtualities were used: Q(2) < 0.02 GeV2, 0.1 < Q(2) < 0.74 GeV2 and 3 < Q(2) < 254 GeV2, corresponding to integrated luminosities of 0.9, 1.85 and 3.38 pb(-1). The cross sections are given as a function of x(L), p(T)(2), Q(2) and the Bjorken scaling variable, x. The ratio of the cross section for leading proton production to the inclusive e(+)p cross section shows only a mild dependence on Q(2) and on x. In the region 0.6 < x(L) < 0.97, the relative yield of protons is only a weak function of x(L). (C) 2003 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, I-87036 Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, Hudson, NY 10027 USA. Inst Nucl Phys, Krakow, Poland. Univ Min & Met Krakow, Fac Phys & Nucl Tech, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, Deutsch Elektronen Synchrotron, Hamburg, Germany. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM b.foster@bristol.ac.uk RI Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; collins-tooth, christopher/A-9201-2012; Ferrando, James/A-9192-2012; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Gliga, Sebastian/K-4019-2015; Suchkov, Sergey/M-6671-2015; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Li, Liang/O-1107-2015; Doyle, Anthony/C-5889-2009; Capua, Marcella/A-8549-2015; OI Gladilin, Leonid/0000-0001-9422-8636; De Pasquale, Salvatore/0000-0001-9236-0748; Ferrando, James/0000-0002-1007-7816; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Gliga, Sebastian/0000-0003-1729-1070; dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Li, Liang/0000-0001-6411-6107; Anzivino, Giuseppina/0000-0002-5967-0952; Doyle, Anthony/0000-0001-6322-6195; Capua, Marcella/0000-0002-2443-6525; Arneodo, Michele/0000-0002-7790-7132; Chwastowski, Janusz/0000-0002-6190-8376; Longhin, Andrea/0000-0001-9103-9936; Gutsche, Oliver/0000-0002-8015-9622 NR 82 TC 21 Z9 21 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 12 PY 2003 VL 658 IS 1-2 BP 3 EP 46 DI 10.1016/S0550-3213(03)00152-4 PG 44 WC Physics, Particles & Fields SC Physics GA 677GU UT WOS:000182799200001 ER PT J AU Weese, RK Maienschein, JL Perrino, CT AF Weese, RK Maienschein, JL Perrino, CT TI Kinetics of the beta -> delta solid-solid phase transition of HMX, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine SO THERMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 3rd International Symposium on the Heat Flow Calorimetry of Energetic Materials CY APR 08-11, 2002 CL FRENCH LICK SPRINGS, INDIANA SP Naval Surface Warfar Ctr, Test & Evaluat Branch DE solid-solid phase; transition; HMX ID THERMAL-ANALYSIS; ACTIVATION; ENERGY AB We apply differential scanning calorimetry (DSC) to measure the kinetics of the beta --> delta solid-solid phase transition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, HMX. Integration of the DSC signal gives a direct measurement of degree of conversion. Data is analyzed by first-order kinetics, the Ozawa method, and isoconversional analysis. The range of activation energies found in this work, centering around 500kJ/mol, is much higher than previously reported values by Brill and co-workers [ALAA J. (1982)], 204 kJ/mol [1], and Henson et al. and Henson and co-workers [B. Henson, L. Smilowitz, B. Asay, P. Dickson, Thermodynamics of the beta to delta phase transition in PBX-9501, in: Proceedings of American Physical Society Topical Group on Shock Compression of Condensed Matter, American Institute of Physics, Atlanta, GA, 2001; L. Smilowitz, B. Henson, J. Robinson, R Dickson, B. Asay, Kinetics of the beta to delta phase transition in PBX-9501, in: Proceedings of American Physical Society Topical Group on Shock Compression of Condensed Matter, American Institute of Physics, Atlanta, GA, 2001; P.M. Dickson, B.W. Asay, B.F. Henson, C.S. Fugard, J. Wong, Measurement of phase change and thermal decomposition kinetics during cookoff of PBX-9501, in: Proceedings of American Physical Society Topical Group on Shock Compression of Condensed Matter, American Institute of Physics, Snowbird, LJT, 1999], 200 kJ/mol [4]. We discuss possible reasons for the higher activation energies measured here but do not identify the cause. (C) 2003 Published by Elsevier Science B.V. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Calif State Univ Hayward, Dept Chem, Hayward, CA 94542 USA. RP Weese, RK (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 26 TC 24 Z9 26 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD MAY 12 PY 2003 VL 401 IS 1 BP 1 EP 7 DI 10.1016/S0040-6031(03)00050-9 PG 7 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 679YJ UT WOS:000182949300002 ER PT J AU Santos, MG Heavens, A Balbi, A Borrill, J Ferreira, PG Hanany, S Jaffe, AH Lee, AT Rabii, B Richards, PL Smoot, GF Stompor, R Winant, CD Wu, JHP AF Santos, MG Heavens, A Balbi, A Borrill, J Ferreira, PG Hanany, S Jaffe, AH Lee, AT Rabii, B Richards, PL Smoot, GF Stompor, R Winant, CD Wu, JHP TI Multiple methods for estimating the bispectrum of the cosmic microwave background with application to the MAXIMA data SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE methods : data analysis; methods : statistical; cosmic microwave background; early Universe ID PRIMORDIAL NON-GAUSSIANITY; ANGULAR POWER SPECTRUM; INFLATIONARY MODELS; PERTURBATIONS; ANISOTROPY; RADIATION; UNIVERSE; MAPS; CMB; CONSTRAINTS AB We describe different methods for estimating the bispectrum of cosmic microwave background data. In particular, we construct a minimum-variance estimator for the flat-sky limit and compare results with previously studied frequentist methods. Application to the MAXIMA data set shows consistency with primordial Gaussianity. Weak quadratic non-Gaussianity is characterized by a tunable parameter f (NL) , corresponding to non-Gaussianity at a level of similar to10(-5) f (NL) (the ratio of non-Gaussian to Gaussian terms), and we find limits of f (NL) = 1500 +/- 950 for the minimum-variance estimator and f (NL) = 2700 +/- 1650 for the usual frequentist estimator. These are the tightest limits on primordial non-Gaussianity, which include the full effects of the radiation transfer function. C1 Univ Oxford, Oxford OX1 3RH, England. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Edinburgh, Astron Inst, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ London Imperial Coll Sci Technol & Med, Astrophys Grp, Blackett Lab, London SW7 2BW, England. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Natl Taiwan Univ, Dept Phys, Taipei 106, Taiwan. RP Santos, MG (reprint author), Univ Oxford, Oxford OX1 3RH, England. EM santos@thphys.ox.ac.uk RI Jaffe, Andrew/D-3526-2009; Santos, Mario/F-2484-2011; OI Santos, Mario/0000-0003-3892-3073; WU, JIUN-HUEI/0000-0001-9608-7662 NR 53 TC 41 Z9 41 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 11 PY 2003 VL 341 IS 2 BP 623 EP 643 DI 10.1046/j.1365-8711.2003.06438.x PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 674TE UT WOS:000182651400022 ER PT J AU Johnstone, C Koscielniak, S AF Johnstone, C Koscielniak, S TI FFAGS for rapid acceleration SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE neutrino factory; nonscaling FFAG; muon acceleration AB When large transverse and longitudinal emittances are to be transported through a circular machine, extremely rapid acceleration holds the advantage that the beam becomes immune to nonlinear resonances because there is insufficient time for amplitudes to build up. Uncooled muon beams exhibit large emittances and require fast acceleration to avoid decay losses and would benefit from this style of acceleration. The approach here employs a fixed-field alternating gradient or FFAG magnet structure and a fixed-frequency acceleration system. Acceptance is enhanced by the use only of linear lattice elements, and fixed-frequency rf enables the use of cavities with large shunt resistance and quality factor. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. RP Johnstone, C (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 28 TC 15 Z9 15 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 MAY 11 PY 2003 VL 503 IS 3 BP 445 EP 457 DI 10.1016/S0168-9002(03)00997-5 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000002 ER PT J AU Semertzidis, YK Bennett, G Efstathiadis, E Krienen, F Larsen, R Lee, YY Morse, WM Orlov, Y Ozben, CS Roberts, BL Snydstrup, LP Warburton, DS AF Semertzidis, YK Bennett, G Efstathiadis, E Krienen, F Larsen, R Lee, YY Morse, WM Orlov, Y Ozben, CS Roberts, BL Snydstrup, LP Warburton, DS TI The Brookhaven muon (g-2) storage ring high voltage quadrupoles SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE storage rings; muon (g-2); electrostatic quadrupoles; detection of axial frequency of trapped electrons ID ANOMALOUS MAGNETIC-MOMENT; FREQUENCY; NMR AB The design, construction, and operation of the electrostatic quadrupoles used in the muon (g - 2) experiment E821 of BNL are described in detail. A new lead design allowed the construction of a very reliable system which could operate for hundreds of thousands pulses with no sparking. The new design also made possible the elimination of systematic errors associated with the E, B fields generated by the low energy trapped electrons present in Penning traps under medium vacuum conditions. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Cornell Univ, Newman Lab, Ithaca, NY 14853 USA. RP Semertzidis, YK (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Semertzidis, Yannis K./N-1002-2013 NR 17 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 11 PY 2003 VL 503 IS 3 BP 458 EP 484 DI 10.1016/S0168-9002(03)00999-9 PG 27 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000003 ER PT J AU Mecking, BA Adams, G Ahmad, S Anciant, E Anghinolfi, M Asavapibhop, B Asryan, G Audit, G Auger, T Avakian, H Ball, JP Barbosa, FJ Barrow, S Battaglieri, M Beard, K Berman, BL Bianchi, N Boiarinov, S Bonneau, P Briscoe, WJ Brooks, WK Burkert, VD Carman, DS Carstens, T Cetina, C Christo, SB Cole, PL Coleman, A Connelly, J Cords, D Corvisiero, P Crabb, D Crannell, H Cuevas, RC Degtyarenko, PV Dennis, L DeSanctis, E DeVita, R Distelbrink, J Dodge, GE Dodge, W Doolittle, G Doughty, D Dugger, M Duncan, WS Dytman, S Egiyan, H Egiyan, KS Elouadrhiri, L Feuerbach, RJ Ficenec, J Frolov, V Funsten, H Gilfoyle, GP Giovanetti, KL Golovatch, E Gram, J Guidal, M Gyurjyan, V Heddle, D Hemler, P Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Insley, D Ito, MM Jacobs, G Jenkins, D Joo, K Joyce, D Kashy, D Khandaker, M Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kramer, L Koubarovski, V Kuhn, SE Lake, A Lawrence, D Longhi, A Lukashin, K Lachniet, J Magahiz, RA Major, W Manak, JJ Marchand, C Martins, C Matthews, SK McMullen, M McNabb, JWC Mestayer, MD Minehart, R Mirazita, M Miskimen, R Muccifora, V Mueller, J Murphy, LY Mutchler, GS Napolitano, J Niculescu, I Niczyporuk, BB Nozar, M O'Brien, JT Opper, AK O'Meara, JE Pasyuk, E Philips, SA Polli, E Price, JW Pozdniakov, S Qin, LM Raue, BA Riccardi, G Ricco, G Riggs, C Ripani, M Ritchie, BG Robb, J Ronchetti, F Rossi, P Roudot, F Salgado, C Sapunenko, V Schumacher, RA Serov, VS Sharabian, YG Smith, ES Smith, LC Smith, T Sober, DI Stavinsky, A Stepanyan, S Stoler, P Taiuti, M Taylor, WM Taylor, S Tedeschi, DJ Thoma, U Thompson, R Tilles, D Todor, L Tung, TY Tuzel, W Vineyard, MF Vlassov, AV Weinstein, LB Welsh, RE Weygand, DP Wilkin, GR Witkowski, M Wolin, E Yegneswaran, A Yergin, P Yun, J AF Mecking, BA Adams, G Ahmad, S Anciant, E Anghinolfi, M Asavapibhop, B Asryan, G Audit, G Auger, T Avakian, H Ball, JP Barbosa, FJ Barrow, S Battaglieri, M Beard, K Berman, BL Bianchi, N Boiarinov, S Bonneau, P Briscoe, WJ Brooks, WK Burkert, VD Carman, DS Carstens, T Cetina, C Christo, SB Cole, PL Coleman, A Connelly, J Cords, D Corvisiero, P Crabb, D Crannell, H Cuevas, RC Degtyarenko, PV Dennis, L DeSanctis, E DeVita, R Distelbrink, J Dodge, GE Dodge, W Doolittle, G Doughty, D Dugger, M Duncan, WS Dytman, S Egiyan, H Egiyan, KS Elouadrhiri, L Feuerbach, RJ Ficenec, J Frolov, V Funsten, H Gilfoyle, GP Giovanetti, KL Golovatch, E Gram, J Guidal, M Gyurjyan, V Heddle, D Hemler, P Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Insley, D Ito, MM Jacobs, G Jenkins, D Joo, K Joyce, D Kashy, D Khandaker, M Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kramer, L Koubarovski, V Kuhn, SE Lake, A Lawrence, D Longhi, A Lukashin, K Lachniet, J Magahiz, RA Major, W Manak, JJ Marchand, C Martins, C Matthews, SK McMullen, M McNabb, JWC Mestayer, MD Minehart, R Mirazita, M Miskimen, R Muccifora, V Mueller, J Murphy, LY Mutchler, GS Napolitano, J Niculescu, I Niczyporuk, BB Nozar, M O'Brien, JT Opper, AK O'Meara, JE Pasyuk, E Philips, SA Polli, E Price, JW Pozdniakov, S Qin, LM Raue, BA Riccardi, G Ricco, G Riggs, C Ripani, M Ritchie, BG Robb, J Ronchetti, F Rossi, P Roudot, F Salgado, C Sapunenko, V Schumacher, RA Serov, VS Sharabian, YG Smith, ES Smith, LC Smith, T Sober, DI Stavinsky, A Stepanyan, S Stoler, P Taiuti, M Taylor, WM Taylor, S Tedeschi, DJ Thoma, U Thompson, R Tilles, D Todor, L Tung, TY Tuzel, W Vineyard, MF Vlassov, AV Weinstein, LB Welsh, RE Weygand, DP Wilkin, GR Witkowski, M Wolin, E Yegneswaran, A Yergin, P Yun, J TI The CEBAF large acceptance spectrometer (CLAS) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE CLAS; magnetic spectrometer; electromagnetic physics; large acceptance; JLab ID ELECTROMAGNETIC SHOWER CALORIMETER; SUPERCONDUCTING TOROIDAL MAGNET; MOLLER POLARIMETER; LEVEL-2 TRIGGER; DRIFT CHAMBERS; DETECTOR; SYSTEM; BREMSSTRAHLUNG; POLARIZATION; DESIGN AB The CEBAF large acceptance spectrometer (CLAS) is used to study photo- and electro-induced nuclear and hadronic reactions by providing efficient detection of neutral and charged particles over a good fraction of the full solid angle. A collaboration of about 30 institutions has designed, assembled, and commissioned CLAS in Hall B at the Thomas Jefferson National Accelerator Facility. The CLAS detector is based on a novel six-coil toroidal magnet which provides a largely azimuthal field distribution. Trajectory reconstruction using drift chambers results in a momentum resolution of 0.5% at forward angles. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 10(34) nucleon cm(-2) s(-1). These capabilities are being used in a broad experimental program to study the structure and interactions of mesons, nucleons, and nuclei using polarized and unpolarized electron and photon beams and targets. This paper is a comprehensive and general description of the design, construction and performance of CLAS. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Thomas Jefferson Natl Accelerator Facil, Jefferson Lab, Newport News, VA 23606 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. Baylor Coll Med, Houston, TX 77030 USA. CEA Saclay, Serv Phys Nucl, F-91191 Gif Sur Yvette, France. Ist Nazl Fis Nucl, Sezione Genova, I-16146 Genoa, Italy. Univ Massachusetts, Amherst, MA 01003 USA. Yerevan Phys Inst, Yerevan 375036, Armenia. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Arizona State Univ, Tempe, AZ 85287 USA. Florida State Univ, Tallahassee, FL 32306 USA. James Madison Univ, Harrisonburg, VA 22807 USA. Coll William & Mary, Williamsburg, VA 23187 USA. George Washington Univ, Washington, DC 20052 USA. Ohio Univ, Athens, OH 45701 USA. Univ Texas, El Paso, TX 79968 USA. Univ Virginia, Charlottesville, VA 22901 USA. Catholic Univ Amer, Washington, DC 20064 USA. Univ New Hampshire, Durham, NH 03824 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Christopher Newport Univ, Newport News, VA 23606 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Univ Richmond, Richmond, VA 23173 USA. Inst Phys Nucl Orsay, F-91406 Orsay, France. Norfolk State Univ, Norfolk, VA 23504 USA. Kyungpook Natl Univ, Taegu 702701, South Korea. Florida Int Univ, Miami, FL 33199 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. Rice Univ, Houston, TX 77005 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Roma 3, I-00146 Rome, Italy. Univ S Carolina, Columbia, SC 29208 USA. RP Smith, ES (reprint author), Thomas Jefferson Natl Accelerator Facil, Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. EM elton@jlab.org RI riccardi, gabriele/A-9269-2012; Brooks, William/C-8636-2013; Schumacher, Reinhard/K-6455-2013; Auger, Thierry/L-1073-2013; OI Brooks, William/0000-0001-6161-3570; Schumacher, Reinhard/0000-0002-3860-1827; Hyde, Charles/0000-0001-7282-8120; Sapunenko, Vladimir/0000-0003-1877-9043 NR 52 TC 395 Z9 399 U1 3 U2 10 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 MAY 11 PY 2003 VL 503 IS 3 BP 513 EP 553 DI 10.1016/S0168-9002(03)01001-5 PG 41 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000007 ER PT J AU Taniguchi, S Nakamura, T Nunomiya, T Iwase, H Yonai, S Sasaki, M Rokni, SH Liu, JC Kase, KR Roesler, S AF Taniguchi, S Nakamura, T Nunomiya, T Iwase, H Yonai, S Sasaki, M Rokni, SH Liu, JC Kase, KR Roesler, S TI Neutron energy and time-of-flight spectra behind the lateral shield of a high energy electron accelerator beam dump. Part I: measurements SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE electron accelerator; neutron spectrum; concrete shielding; deep penetration; organic liquid scintillator; TOF spectrum ID ORGANIC LIQUID SCINTILLATOR; RESPONSE FUNCTION; RANGE AB Neutron energy and time-of-flight spectra were measured behind the lateral shield of the electron beam dump at the Final Focus Test Beam (FFTB) facility at the Stanford Linear Accelerator Center. The neutrons were produced by a 28.7 GeV electron beam hitting the aluminum beam dump of the FFTB which is housed inside a thick steel and concrete shield. The measurements were performed using an NE213 organic liquid scintillator behind different thicknesses of the concrete shield of 274, 335, and 396 cm, respectively. The neutron energy spectra between 6 and 800 MeV were obtained by unfolding the measured pulse height spectrum with the detector response function. The attenuation length of neutrons in concrete was then derived. The spectra of neutron time-of-flight between beam on dump and neutron detection by NE213 were also measured. The corresponding experimental results were simulated with the FLUKA Monte Carlo code. The experimental results show good agreement with the simulated results. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. Japan Synchrotron Radiat Res Inst, Mikazuki, Hyogo 6795198, Japan. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CERN, TIS RP, CH-1211 Geneva 23, Switzerland. Cent Res Inst Elect Power Ind, Komae Lab, Tokyo 201, Japan. RP Nakamura, T (reprint author), Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. NR 16 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 11 PY 2003 VL 503 IS 3 BP 595 EP 605 DI 10.1016/S0168-9002(03)01002-7 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000013 ER PT J AU Roesler, S Liu, JC Rokni, SH Taniguchi, S AF Roesler, S Liu, JC Rokni, SH Taniguchi, S TI Neutron energy and time-of-flight spectra behind the lateral shield of a high energy electron accelerator beam dump. Part II: Monte Carlo simulations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE electron accelerator; neutron spectrum; time-of-flight spectrum; deep penetration; FLUKA AB Energy spectra of high-energy neutrons and neutron time-of-flight spectra were calculated for the setup of experiment T-454 performed with a NE213 liquid scintillator at the Final Focus Test Beam (FFTB) facility at the Stanford Linear Accelerator Center. The neutrons were created by the interaction a 28.7 GeV electron beam in the aluminum beam dump of the FFTB which is housed inside a thick steel and concrete shielding. In order to determine the attenuation length of high-energy neutrons additional concrete shielding of various thicknesses was placed outside the existing shielding. The calculations were performed using the FLUKA interaction and transport code. The energy and time-of-flight spectra were recorded for the location of the detector allowing a detailed comparison with the experimental data. A generally good description of the data is achieved adding confidence to the use of FLUKA for the design of shielding for high-energy electron accelerators. (C) 2003 Elsevier Science B.V. All rights reserved. C1 CERN, CH-1211 Geneva 23, Switzerland. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Japan Synchrotron Radiat Res Inst, Mikazuki, Hyogo 6795198, Japan. RP Roesler, S (reprint author), CERN, CH-1211 Geneva 23, Switzerland. NR 5 TC 7 Z9 7 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 MAY 11 PY 2003 VL 503 IS 3 BP 606 EP 616 DI 10.1016/S0168-9002(03)01003-9 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000014 ER PT J AU Arnold, R Augier, C Baker, J Barabash, AS Bing, O Brudanin, V Caffrey, AJ Caurier, E Errahmane, K Etienvre, AI Guyonnet, JL Hubert, F Hubert, P Jollet, C Jullian, S Kochetov, O Kovalenko, V Lalanne, D Leccia, F Longuemare, C Marquet, C Mauger, F Nicholson, HW Ohsumi, H Piquemal, F Reyss, JL Sarazin, X Shitov, Y Simard, L Stekl, I Suhonen, J Sutton, CS Szklarz, G Timkin, V Tretyak, V Umatov, V Vala, L Vanyushin, I Vasilyev, V Vorobel, V Vylov, T AF Arnold, R Augier, C Baker, J Barabash, AS Bing, O Brudanin, V Caffrey, AJ Caurier, E Errahmane, K Etienvre, AI Guyonnet, JL Hubert, F Hubert, P Jollet, C Jullian, S Kochetov, O Kovalenko, V Lalanne, D Leccia, F Longuemare, C Marquet, C Mauger, F Nicholson, HW Ohsumi, H Piquemal, F Reyss, JL Sarazin, X Shitov, Y Simard, L Stekl, I Suhonen, J Sutton, CS Szklarz, G Timkin, V Tretyak, V Umatov, V Vala, L Vanyushin, I Vasilyev, V Vorobel, V Vylov, T TI Possible background reductions in double beta decay experiments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE double beta decay; neutrino; molybdenum-100 ID NEUTRINO MASS-SPECTRUM; NEMO EXPERIMENT AB The background induced by radioactive impurities of (TI)-T-208 and Bi-214 in the source of the double beta experiment NEMO-3 has been investigated. New methods of data analysis which decrease the background from the above mentioned contamination are identified. The techniques can also be applied to other double beta decay experiments capable of measuring independently the energies of the two electrons. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Inst Theoret & Expt Phys, Moscow 117259, Russia. CNRS, IN2P3, IReS, F-67037 Strasbourg, France. Univ Strasbourg, F-67037 Strasbourg, France. CNRS, IN2P3, LAL, F-91405 Orsay, France. Univ Paris 11, F-91405 Orsay, France. INEEL, Idaho Falls, ID 83415 USA. JINR, Dubna 141980, Russia. CNRS, IN2P3, CENGB, F-33170 Gradignan, France. Univ Bordeaux 1, F-33170 Gradignan, France. CNRS, IN2P3, LPG, F-14032 Caen, France. Univ Caen, F-14032 Caen, France. Mt Holyoke Coll, S Hadley, MA 01075 USA. Saga Univ, Saga 8408502, Japan. CNRS, CFR, F-91190 Gif Sur Yvette, France. Czech Tech Univ, FNSPE, Prague 11519, Czech Republic. Univ Jyvaskyla, SF-40351 Jyvaskyla, Finland. Charles Univ Prague, Prague, Czech Republic. RP Inst Theoret & Expt Phys, B Cheremushkinskaya 25, Moscow 117259, Russia. EM barabash@vxitep.itep.ru RI Caffrey, Augustine/C-2005-2009; Vala, Ladislav/L-4938-2016; Barabash, Alexander/S-8851-2016 NR 13 TC 5 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 11 PY 2003 VL 503 IS 3 BP 649 EP 657 DI 10.1016/S0168-9002(03)00992-6 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000017 ER PT J AU Plum, MA Bravin, E Bosser, J Maccaferri, R AF Plum, MA Bravin, E Bosser, J Maccaferri, R TI N-2 and Xe gas scintillation cross-section, spectrum, and lifetime measurements from 50 MeV to 25 GeV at the CERN PS and Booster (vol 492, pg 74, 2002) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Correction C1 LANL, SNS DO, Los Alamos, NM 87454 USA. CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland. RP Plum, MA (reprint author), LANL, SNS DO, MS H838, Los Alamos, NM 87454 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 11 PY 2003 VL 503 IS 3 BP 659 EP 659 DI 10.1016/S0168-9002(03)00996-3 PG 1 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 685AE UT WOS:000183238000018 ER PT J AU Boehlert, CJ Farr, JD Schulze, RK Pereyra, RA Archuleta, JA AF Boehlert, CJ Farr, JD Schulze, RK Pereyra, RA Archuleta, JA TI Initial electron back-scattered diffraction observations of cerium SO PHILOSOPHICAL MAGAZINE LA English DT Article AB The first electron back-scattered diffraction Kikuchi patterns and grain orientation maps were captured for pure gamma-phase (fcc) Ce. The sample preparation technique used for electron back-scattered diffraction orientation mapping of this surface-reactive metal included ion sputtering the surface using a scanning Auger microprobe followed by vacuum transfer of the sample from the scanning Auger microprobe to the scanning electron microscope. The effect of ion sputtering on the microstructure as well as preliminary electron back-scattered diffraction microstructural characterization is presented. Based on the sputtering data, the room-temperature diffusivity of O in gamma-Ce was estimated. C1 Alfred Univ, Alfred, NY 14802 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Boehlert, CJ (reprint author), Alfred Univ, Alfred, NY 14802 USA. NR 12 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1478-6443 J9 PHILOS MAG JI Philos. Mag. PD MAY 11 PY 2003 VL 83 IS 14 BP 1735 EP 1744 DI 10.1080/1478643031000080708 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 680QM UT WOS:000182988900007 ER PT J AU Chang, C Naulleau, P Attwood, D AF Chang, C Naulleau, P Attwood, D TI Analysis of illumination coherence properties in small-source systems such as synchrotrons SO APPLIED OPTICS LA English DT Article ID SOFT-X-RAY; SPATIAL COHERENCE; RADIATION AB Modern synchrotron beamlines often take the form of critical illumination systems, where an incoherent source of limited spatial extent is re-imaged to an experimental plane of interest. Unique constraints of synchrotron sources and beamlines, however, may preclude the use of the simple Zernike approximation for calculating the object-image coherence relationship. Here, we perform a rigorous analysis of the object-image coherence relationship valid for synchrotron beamlines. The analysis shows that beamline aberrations have an effect on the coherence properties. Effects of various low-order aberrations on the coherence properties are explicitly studied. (C) 2003 Optical Society of America. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr X ray Opt, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Chang, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr X ray Opt, Berkeley, CA 94720 USA. EM cnchang@lbl.gov NR 15 TC 6 Z9 6 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD MAY 10 PY 2003 VL 42 IS 14 BP 2506 EP 2512 DI 10.1364/AO.42.002506 PG 7 WC Optics SC Optics GA 676CT UT WOS:000182734900005 PM 12749562 ER PT J AU Combi, JA Romero, GE Paredes, JM Torres, DF Ribo, M AF Combi, JA Romero, GE Paredes, JM Torres, DF Ribo, M TI Discovery of a new radio galaxy within the error box of the unidentified gamma-ray source 3EG J1735-1500 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; gamma rays : observations; radio continuum : galaxies ID CENTAURUS-A; VARIABILITY; EMISSION; NUCLEUS; STARS; SKY; MHZ AB We report the discovery of a new radio galaxy within the location error box of the gamma-ray source 3EG J1735-1500. The galaxy is a double-sided jet source forming a large angle with the line of sight. Optical observations reveal a Vsimilar to18 mag galaxy at the position of the radio core. Although the association with the EGRET source is not confirmed at present because there is a competing, alternative gamma-ray candidate within the location error contours, which we also study here, the case deserves further attention. The new radio galaxy can be used to test the recently proposed possibility of gamma-ray-emitting radio galaxies beyond the already known case of Centaurus A. C1 Inst Argentino Radioastron, RA-1894 Buenos Aires, DF, Argentina. Univ Barcelona, Dept Astron & Meteorol, E-08028 Barcelona, Spain. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Combi, JA (reprint author), Inst Argentino Radioastron, CC5, RA-1894 Buenos Aires, DF, Argentina. RI Ribo, Marc/B-3579-2015; Torres, Diego/O-9422-2016; OI Torres, Diego/0000-0002-1522-9065; Ribo, Marc/0000-0002-9931-4557; Paredes, Josep M./0000-0002-1566-9044 NR 23 TC 21 Z9 21 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 MAY 10 PY 2003 VL 588 IS 2 BP 731 EP 735 DI 10.1086/374314 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 680RV UT WOS:000182991900008 ER PT J AU Done, C Madejski, GM Zycki, PT Greenhill, LJ AF Done, C Madejski, GM Zycki, PT Greenhill, LJ TI Simultaneous Chandra and Rossi X-Ray Timing Explorer observations of the nearby bright Seyfert 2 galaxy NGC 4945 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 4945); galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; MASER EMISSION; COLD MATTER; XMM-NEWTON; NGC-4945; SPECTROSCOPY; NGC-3079; DISK; GAS; REFLECTION AB We analyze recent simultaneous Chandra/RXTE observations of the Seyfert 2 galaxy NGC 4945. The unprecedented spatial resolution of Chandra means we are able to separate the spectra of the nucleus, starburst, and superwind regions, while the RXTE data extend the spectrum to higher energies. The extreme absorbing column of NHsimilar to4x10(24) cm(-2) means that the nucleus is only directly seen above 8-10 keV, while the lower energy spectrum from the nuclear region in Chandra is dominated by reflection. By contrast, the superwind is dominated by emission from hot plasma, but the starburst region contains both hot plasma and reflection signatures. Forming a reflected spectrum requires that the starburst region contain clumps of cool, optically thick material, perhaps star-forming cores, which are irradiated by 7-10 keV photons from the nucleus. Since photons of this energy are obscured along the line of sight, this confirms the result of Madejski et al. that the extreme absorption material is disklike rather than toroidal. However, the IR/optical limits on the lack of high-excitation emission lines show that, by contrast, the lower energy photons from the nucleus are obscured in all directions. We discuss the complex absorption structure revealed by these observations and propose an overall source geometry in which the nucleus is completely embedded in material with NHsimilar to10(23) cm(-2). C1 Univ Durham, Dept Phys, Durham DH1 3LE, England. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Nicolaus Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Done, C (reprint author), Univ Durham, Dept Phys, South Rd, Durham DH1 3LE, England. RI done, chris/D-4605-2016 OI done, chris/0000-0002-1065-7239 NR 39 TC 35 Z9 35 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 MAY 10 PY 2003 VL 588 IS 2 BP 763 EP 770 DI 10.1086/374332 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 680RV UT WOS:000182991900011 ER PT J AU Yanny, B Newberg, HJ Grebel, EK Kent, S Odenkirchen, M Rockosi, CM Schlegel, D Subbarao, M Brinkmann, J Fukugita, M Ivezic, Z Lamb, DQ Schneider, DP York, DG AF Yanny, B Newberg, HJ Grebel, EK Kent, S Odenkirchen, M Rockosi, CM Schlegel, D Subbarao, M Brinkmann, J Fukugita, M Ivezic, Z Lamb, DQ Schneider, DP York, DG TI A low-latitude halo stream around the Milky Way SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : halo; Galaxy : structure ID DIGITAL SKY SURVEY; GALACTIC HALO; STELLAR POPULATION; GLOBULAR-CLUSTER; STARS; GALAXY; KINEMATICS; DISK AB We present evidence for a ring of stars in the plane of the Milky Way, extending at least from l=180degrees to 227degrees with turnoff magnitude gsimilar to19.5; the ring could encircle the Galaxy. We infer that the low Galactic latitude structure is at a fairly constant distance of R=18+/-2 kpc from the Galactic center above the Galactic plane and has R=20+/-2 kpc in the region sampled below the Galactic plane. The evidence includes 500 Sloan Digital Sky Survey spectroscopic radial velocities of stars within 30degrees of the plane. The velocity dispersion of the stars associated with this structure is found to be 27 km s(-1) at (l,b)=(198degrees, -27degrees), 22 km s(-1) at (l,b)=(225degrees, 28degrees), 30 km s(-1) at (l,b)=(188degrees, 24degrees), and 30 km s(-1) at (l,b)=(182degrees, 27degrees). The structure rotates in the same prograde direction as the Galactic disk stars but with a circular velocity of 110+/-25 km s(-1). The narrow measured velocity dispersion is inconsistent with power-law spheroid or thick-disk populations. We compare the velocity dispersion in this structure with the velocity dispersion of stars in the Sagittarius dwarf galaxy tidal stream, for which we measure a velocity dispersion of 20 km s(-1) at (l,b)=(165degrees, -55degrees). We estimate a preliminary metallicity from the Ca II (K) line and color of the turnoff stars of [Fe/H]= -1.6 with a dispersion of 0.3 dex and note that the turnoff color is consistent with that of the spheroid population. We interpret our measurements as evidence for a tidally disrupted satellite of 2x10(7) to 5x10(8) M-circle dot that rings the Galaxy. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Univ Washington, Seattle, WA 98195 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Apache Point Observ, Sunspot, NM 88349 USA. Univ Tokyo, Inst Cosm Ray Res, Tokyo, Japan. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. RP Yanny, B (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. OI /0000-0002-1891-3794 NR 46 TC 304 Z9 309 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 2003 VL 588 IS 2 BP 824 EP 841 DI 10.1086/374220 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 680RV UT WOS:000182991900016 ER PT J AU Desai, MI Mason, GM Dwyer, JR Mazur, JE Gold, RE Krimigis, SM Smith, CW Skoug, RM AF Desai, MI Mason, GM Dwyer, JR Mazur, JE Gold, RE Krimigis, SM Smith, CW Skoug, RM TI Evidence for a suprathermal seed population of heavy ions accelerated by interplanetary shocks near 1 AU SO ASTROPHYSICAL JOURNAL LA English DT Article DE interplanetary medium; shock waves; solar wind; Sun : activity; Sun : particle emission ID ENERGETIC PARTICLE EVENTS; COROTATING INTERACTION REGIONS; SOLAR-WIND; TRAVELING SHOCKS; ACE SPACECRAFT; CHARGE STATES; HE-3; SPECTROMETER; HELIOSPHERE; ABUNDANCES AB We have surveyed the 0.1-10 MeV nucleon(-1) elemental abundances at 72 interplanetary (IP) shocks observed by the Ultra-Low-Energy Isotope Spectrometer on board the Advanced Composition Explorer from 1997 October through 2002 September. We find the following: (1) The C/O ratios in IP shocks were substantially depleted (by more than similar to40%) relative to solar wind values. (2) The IP shock abundances were poorly correlated with those measured in the slow and fast solar wind. (3) Energetic ions above similar to0.1 MeV nucleon(-1) from impulsive and gradual solar energetic particle events (SEPs) were present upstream of all the IP shocks in our survey. (4) The similar to1 MeV nucleon similar to1 Fe/O ratio in IP shocks was positively correlated with that measured upstream of the shocks. (5) The IP shock abundances were well correlated with the upstream abundances, with a negative dependence on mass/charge. (6) The mean Fe/O ratio in IP shocks exhibited a positive correlation with the level of solar activity, as measured by the occurrence rates of X-ray flares and sunspots. The above results are inconsistent with shock acceleration of ions originating mainly from the bulk solar wind or a suprathermal tail composed predominantly of solar wind ions. Instead, it appears that for the events surveyed here, the IP shocks accelerated a seed population predominantly comprising ions that were previously accelerated in impulsive and gradual SEPs and that the shock acceleration process accelerated higher rigidity ions less efficiently than lower rigidity ions. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Florida Inst Technol, Melbourne, FL 32901 USA. Aerosp Corp, El Segundo, CA 92957 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. RP Univ Maryland, Dept Phys, College Pk, MD 20742 USA. NR 47 TC 100 Z9 100 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 2003 VL 588 IS 2 BP 1149 EP 1162 DI 10.1086/374310 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 680RV UT WOS:000182991900041 ER PT J AU Moon, YJ Choe, GS Wang, HM Park, YD AF Moon, YJ Choe, GS Wang, HM Park, YD TI Sympathetic coronal mass ejections SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : coronal mass ejections (CMEs) ID FLARES; EVENTS; REGION; LASCO; EIT AB We address the question whether there exist sympathetic coronal mass ejections (CMEs), which take place almost simultaneously in different locations with a certain physical connection. For this study, the following three investigations are performed. First, we have examined the waiting-time distribution of the CMEs that were observed by the SOHO Large Angle and Spectrometric Coronagraph (LASCO) from 1999 February to 2001 December. The observed waiting-time distribution is found to be well approximated by a time-dependent Poisson distribution without any noticeable overabundance at short waiting times. Second, we have investigated the angular difference distribution of successive CME pairs to examine their spatial correlations. A remarkable overabundance relative to background levels is found within 10degrees of the position angle difference, which supports the existence of quasi-homologous CMEs that occur sequentially in the same active region. Both of the above results indicate that sympathetic (interdependent) CMEs are far less frequent than independent CMEs. Third, we have examined the EUV Imaging Telescope running difference images and the LASCO images of quasi-simultaneous CME pairs and found a candidate sympathetic CME pair, of which the second CME may be initiated by the eruption of the first CME. Possible mechanisms of the sympathetic CME triggering are discussed. C1 New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. Korea Astron Observ, Taejon 305348, South Korea. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Moon, YJ (reprint author), New Jersey Inst Technol, Big Bear Solar Observ, 40386 N Shore Lane, Big Bear City, CA 92314 USA. RI Moon, Yong-Jae/E-1711-2013; Choe, Gwangson/E-2366-2013 NR 23 TC 20 Z9 20 U1 0 U2 4 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 MAY 10 PY 2003 VL 588 IS 2 BP 1176 EP 1182 DI 10.1086/374270 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 680RV UT WOS:000182991900043 ER PT J AU Mauche, CW Liedahl, DA Fournier, KB AF Mauche, CW Liedahl, DA Fournier, KB TI The Fe XXII I(11.92 angstrom)/I(11.77 angstrom) density diagnostic applied to the Chandra high energy transmission grating spectrum of EX Hydrae SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; binaries : close; stars : individual (EX Hydrae); stars : magnetic fields; X-rays : binaries ID X-RAY-SPECTRA; RATE COEFFICIENTS; SOLAR-FLARES; IONS; IRON; EXCITATION; PLASMAS; RATIOS; ATOMS; NI AB Using the Livermore X-ray Spectral Synthesizer, which calculates spectral models of highly charged ions based primarily on HULLAC atomic data, we investigate the temperature, density, and photoexcitation dependence of the I(11.92 Angstrom)/I(11.77 Angstrom) line ratio of Fe XXII. We find that this line ratio has a critical density n(c) approximate to 5 x 10(13) cm(-3), is approximately 0.3 at low densities and 1.5 at high densities, and is very insensitive to temperature and photoexcitation; therefore, it is a useful density diagnostic for sources like magnetic cataclysmic variables, in which the plasma densities are high and in which the efficacy of the He-like ion density diagnostic is compromised by the presence of a bright ultraviolet continuum. Applying this diagnostic to the Chandra High Energy Transmission Grating spectrum of the intermediate polar EX Hya, we find that the electron density of its T-e approximate to 12 MK plasma is n(e) = 1.0(-0.5)(+2.0) x 10(14) cm(-3), which is orders of magnitude greater than that typically observed in the Sun or other late-type stars. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mauche, CW (reprint author), Lawrence Livermore Natl Lab, L-473,7000 E Ave, Livermore, CA 94550 USA. NR 30 TC 24 Z9 24 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 MAY 10 PY 2003 VL 588 IS 2 BP L101 EP L104 DI 10.1086/375684 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 680RW UT WOS:000182992000009 ER PT J AU de la Figuera, J Carter, CB Bartelt, NC Hwang, RQ AF de la Figuera, J Carter, CB Bartelt, NC Hwang, RQ TI Interplay between gas adsorption and dislocation structure on a metal surface SO SURFACE SCIENCE LA English DT Article DE surface defects; surface stress; corrosion; scanning tunneling microscopy; atomistic dynamics; ruthenium; copper ID SCANNING-TUNNELING-MICROSCOPY; FILMS; RECONSTRUCTION; PT(111); GROWTH AB The influence of oxygen and sulfur on the dislocation patterns of the strained two monolayer Cu film on Ru was observed by scanning tunneling microscopy. Both oxygen and sulfur adsorption lead to the formation of vacancies that aggregate over existing dislocations in the film, thereby modifying the dislocation structure. With increasing adsorbate coverage the overall dislocation structure and pattern are transformed. The atomic mechanisms and general nature of this transformation can be explained in terms of generic dislocation reactions. This interpretation is also supported by atomistic simulations. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. RP de la Figuera, J (reprint author), Univ Autonoma Madrid, Dept Fis Mat Condensada, Cantoblanco, E-28049 Madrid, Spain. RI de la Figuera, Juan/E-7046-2010; Bartelt, Norman/G-2927-2012; Carter, C. Barry/E-6478-2010 OI de la Figuera, Juan/0000-0002-7014-4777; Carter, C. Barry/0000-0003-4251-9102 NR 17 TC 8 Z9 8 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 10 PY 2003 VL 531 IS 1 BP 29 EP 38 DI 10.1016/S0039-6028(03)00401-1 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 676HC UT WOS:000182744400007 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(1 1 1)-(2 x 2) selvedge of alpha-Fe2O3(0 0 0 1) (vol 524, pg 113, 2003) SO SURFACE SCIENCE LA English DT Correction DE molecule-solid reactions; synchrotron radiation photoelectron spectroscopy; thermal desorption spectroscopy; surface chemical reaction; iron oxide; halides C1 Columbia Univ, Ctr Integrated Sci & Engn, Mat Sci Program, Dept Appl Phys & Appl Math, New York, NY 10027 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Columbia Univ, Environm Mol Sci Inst, New York, NY 10027 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Osgood, RM (reprint author), Columbia Univ, Ctr Integrated Sci & Engn, Mat Sci Program, Dept Appl Phys & Appl Math, 530 W 120th St, New York, NY 10027 USA. RI Fitts, Jeffrey/J-3633-2012 NR 1 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 10 PY 2003 VL 531 IS 1 BP 93 EP 93 DI 10.1016/S0039-6028(03)00390-X PG 1 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 676HC UT WOS:000182744400013 ER PT J AU Banerjee, S Kahn, MGC Wong, SS AF Banerjee, S Kahn, MGC Wong, SS TI Rational chemical strategies for carbon nanotube functionalization SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE nanostructures; nanotechnology; nanotubes; ozonolysis; synthesis design ID OPTICAL-PROPERTIES; CHROMATOGRAPHIC PURIFICATION; STRUCTURAL CHARACTERIZATION; SIDEWALL FUNCTIONALIZATION; WATER-SOLUBILIZATION; ELECTRONIC-STRUCTURE; PHASE OZONOLYSIS; CHEMISTRY; DISSOLUTION; IRIDIUM(I) AB Whereas the chemistry of fullerenes is well-established, the chemistry of single-walled carbon nanotubes (SWNTs) is a relatively unexplored field of research. Investigations into the bonding of moieties onto SWNTs are important because they provide fundamental structural insight into how nanoscale interactions occur. Hence, understanding SANT chemistry becomes critical to rational, predictive manipulation of their properties. Among the strategies discussed include molecular metal complexation with SWNTs to control site-selective chemistry in these systems. In particular, work has been performed with Vaska's and Wilkinson's complexes to create functionalized adducts. Functionalization should offer a relatively simple means of tube solubilization and bundle exfoliation, and also allows for tubes to be utilized as recoverable catalyst supports. Solubilization of oxidized SWNTs has also been achieved through derivatization by using a functionalized organic crown ether. The resultant adduct yielded concentrations of dissolved nanotubes on the order of 1 gL(-1) in water and at elevated concentrations in a range of organic solvents, traditionally poor for SWNT manipulation. To further demonstrate chemical processability of SWNTs, we have subjected them to ozonolysis, followed by treatment with various independent reagents, to rationally generate a higher proportion of oxygenated functional groups on the nanotube surface. This protocol has been found to purify nanotubes. More importantly, the reaction sequence has been found to ozonize the sidewalls of these nanotubes. Finally, SWNTs have also been chemically modified with quantum dots and oxide nanocrystals. A composite heterostructure consisting of nanotubes joined to nanocrystals offers a unique opportunity to obtain desired physical, electronic, and chemical properties by adjusting synthetic conditions to tailor the size and structure of the individual sub-components, with implications for self-assembly. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem & Mat Sci, Upton, NY 11973 USA. RP Wong, SS (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. EM sswong@notes.cc.sunysb.edu NR 70 TC 52 Z9 52 U1 5 U2 24 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0947-6539 J9 CHEM-EUR J JI Chem.-Eur. J. PD MAY 9 PY 2003 VL 9 IS 9 BP 1899 EP 1908 DI 10.1002/chem.200204618 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 679KW UT WOS:000182922100001 ER PT J AU Sutton, A Shia, WJ Band, D Kaufman, PD Osada, S Workman, JL Sternglanz, R AF Sutton, A Shia, WJ Band, D Kaufman, PD Osada, S Workman, JL Sternglanz, R TI Sas4 and Sas5 are required for the histone acetyltransferase activity of Sas2 in the SAS complex SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ASSEMBLY FACTOR-I; RNA-POLYMERASE-II; SACCHAROMYCES-CEREVISIAE; SILENCING PROTEIN; DNA-REPLICATION; CHROMATIN; ACETYLATION; ASF1; HETEROCHROMATIN; TRANSCRIPTION AB The SAS2 gene is involved in transcriptional silencing in Saccharomyces cerevisiae. Based on its primary sequence, the Sas2 protein is predicted to be a member of the MYST family of histone acetyltransferases (HATs). Sas2 forms a complex with Sas4 and Sas5, which are required for its silencing function. Here we show that recombinant Sas2 has HAT activity that absolutely requires Sas4 and is stimulated by Sas5. The recombinant SAS complex acetylates H4 lysine 16 and H3 lysine 14. Furthermore, a purified SAS complex from yeast shows similar activity and specificity. In contrast to other MYST HATs, neither the recombinant nor the native SAS complex acetylated nucleosomal histones under conditions that were optimum for acetylating free histones. Finally, although the SAS subunits interact genetically and physically with Asf1, a histone deposition factor, association of H3 and H4 with Asf1 blocks their acetylation by the SAS complex, raising the possibility that the SAS HAT complex may acetylate free histones prior to their deposition onto DNA by Asf1 or CAF-I. C1 SUNY Stony Brook, Dept Biochem & Cell Biol, Stony Brook, NY 11794 USA. Penn State Univ, Dept Biochem & Mol Biol, Howard Hughes Med Inst, University Pk, PA 16802 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cellular Biol, Berkeley, CA 94720 USA. Osaka Univ, Grad Sch Pharmaceut Sci, Lab Environm Biochem, Suita, Osaka 5650871, Japan. RP Sternglanz, R (reprint author), SUNY Stony Brook, Dept Biochem & Cell Biol, Stony Brook, NY 11794 USA. OI Kaufman, Paul/0000-0003-3089-313X NR 36 TC 52 Z9 58 U1 0 U2 2 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 MAY 9 PY 2003 VL 278 IS 19 BP 16887 EP 16892 DI 10.1074/jbc.M210709200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 677QG UT WOS:000182818600060 PM 12626510 ER PT J AU Johnson, KJ Wright, BW Jarman, KH Synovec, RE AF Johnson, KJ Wright, BW Jarman, KH Synovec, RE TI High-speed peak matching algorithm for retention time alignment of gas chromatographic data for chemometric analysis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE peak matching algorithm; retention times; diesel fuel; principal component analysis ID PROFILES; RESOLUTION AB A rapid retention time alignment algorithm was developed as a preprocessing utility to be used prior to chemometric analysis of large datasets of diesel fuel profiles obtained using gas chromatography (GC). Retention time variation from chromatogram-to-chromatogram has been a significant impediment against the use of chemometric techniques in the analysis of chromatographic data due to the inability of current chemometric techniques to correctly model information that shifts from variable to variable within a dataset. The alignment algorithm developed is shown to increase the efficacy of pattern recognition methods applied to diesel fuel chromatograms by retaining chemical selectivity while reducing chromatogram-to-chromatogram retention time variations and to do so on a time scale that makes analysis of large sets of chromatographic data practical. Two sets of diesel fuel gas chromatograms were studied using the novel alignment algorithm followed by principal component analysis (PCA). In the first study, retention times for corresponding chromatographic peaks in 60 chromatograms varied by as much as 300 ms between chromatograms before alignment. In the second study of 42 chromatograms, the retention time shifting exhibited was on the order of 10 s between corresponding chromatographic peaks, and required a coarse retention time correction prior to alignment with the algorithm. In both cases, an increase in retention time precision afforded by the algorithm was clearly visible in plots of overlaid chromatograms before and then after applying the retention time alignment algorithm. Using the alignment algorithm, the standard deviation for corresponding peak retention times following alignment was 17 ms throughout a given chromatogram, corresponding to a relative standard deviation of 0.003% at an average retention time of 8 min. This level of retention time precision is a 5-fold improvement over the retention time precision initially provided by a state-of-the-art GC instrument equipped with electronic pressure control and was critical to the performance of the chemometric analysis. This increase in retention time precision does not come at the expense of chemical selectivity, since the PCA results suggest that essentially all of the chemical selectivity is preserved. Cluster resolution between dissimilar groups of diesel fuel chromatograms in a two-dimensional scores space generated with PCA is shown to substantially increase after alignment. The alignment method is robust against missing or extra peaks relative to a target chromatogram used in the alignment, and operates at high speed, requiring roughly 1 s of computation time per GC chromatogram. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Washington, Dept Chem, Ctr Proc Analyt Chem, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Synovec, RE (reprint author), Univ Washington, Dept Chem, Ctr Proc Analyt Chem, Box 351700, Seattle, WA 98195 USA. NR 9 TC 132 Z9 143 U1 3 U2 25 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 MAY 9 PY 2003 VL 996 IS 1-2 BP 141 EP 155 DI 10.1016/S0021-9673(03)00616-2 PG 15 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 687HU UT WOS:000183371300012 PM 12830915 ER PT J AU Ackerman, TP Flynn, DM Marchand, RT AF Ackerman, TP Flynn, DM Marchand, RT TI Quantifying the magnitude of anomalous solar absorption SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE solar radiation; atmosphere absorption; clouds ID ATMOSPHERIC RADIATION MEASUREMENT; SHORTWAVE EXPERIMENT ARESE; CLOUD ABSORPTION; AIRCRAFT; CLIMATE; SURFACE; IRRADIANCE; PROGRAMS; BUDGET; MODEL AB [1] The data set from ARESE II, sponsored by the Atmospheric Radiation Measurement Program, provides a unique opportunity to understand solar absorption in the atmosphere because of the combination of three sets of broadband solar radiometers mounted on the Twin Otter aircraft and the ground based instruments at the Atmospheric Radiation Measurement (ARM) Southern Great Plains facility. In this study, we analyze the measurements taken on two clear-sky days and three cloudy days and model the solar radiative transfer in each case with two different models. On the two clear days, the calculated and measured column absorptions agree to better than 10 W m(-2), which is about 10% of the total column absorption. Because both the model fluxes and the individual radiometer measurements are accurate to no better than 10 W m(-2), we conclude that the models and measurements are essentially in agreement. For the three cloudy days, the model calculations agree very well with each other and on 2 of the 3 days agree with the measurements to 20 W m(-2) or less out of a total column absorption of more than 200 W m(-2), which is again an agreement at better than 10%. On the third day, the model and measurements agree to either 8 or 14% depending on which value of surface albedo is used. Differences exceeding 10% represent a significant absorption difference between model and observations. In addition to the uncertainty in absorption due to surface albedo, we show that including aerosol with an optical depth similar to that found on clear days can reduce the difference between model and measurement by 5% or more. Thus we conclude that the ARESE II results are incompatible with previous studies reporting extreme anomalous absorption and can be modeled with our current understanding of radiative transfer. C1 US DOE, Atmospher Radiat Measurement Program, Pacific NW Natl Lab, Richland, WA 99352 USA. RP Ackerman, TP (reprint author), US DOE, Atmospher Radiat Measurement Program, Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM ackerman@pnl.gov NR 34 TC 0 Z9 0 U1 0 U2 1 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 MAY 9 PY 2003 VL 109 IS D9 AR 4273 DI 10.1029/2002JD002674 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 678PD UT WOS:000182874900001 ER PT J AU Aubert, B Barate, R Boutigny, D Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Robbe, P Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kral, JF LeClerc, C Levi, ME Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Romosan, A Ronan, MT Shelkov, VG Telnov, AV Wenzel, WA Harrison, TJ Hawkes, CM Knowles, DJ O'Neale, SW Penny, RC Watson, AT Watson, NK Deppermann, T Goetzen, K Koch, H Lewandowski, B Pelizaeus, M Peters, K Schmuecker, H Steinke, M Barlow, NR Bhimji, W Boyd, JT Chevalier, N Clark, PJ Cottingham, WN Mackay, C Wilson, FF Hearty, C Mattison, TS McKenna, JA Thiessen, D Jolly, S Kyberd, P McKemey, AK Blinov, VE Bukin, AD Buzykaev, AR Golubev, VB Ivanchenko, VN Korol, AA Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Yushkov, AN Best, D Chao, M Kirkby, D Lankford, AJ Mandelkern, M McMahon, S Mommsen, RK Stoker, DP Buchanan, C Hadavand, HK Hill, EJ MacFarlane, DB Paar, HP Rahatlou, S Raven, G Schwanke, U Sharma, V Berryhill, JW Campagnari, C Dahmes, B Kuznetsova, N Levy, SL Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beringer, J Eisner, AM Grothe, M Heusch, CA Lockman, WS Pulliam, T Schalk, T Schmitz, RE Schumm, BA Seiden, A Turri, M Walkowiak, W Williams, DC Wilson, MG Albert, J Chen, E Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Narsky, I Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Barillari, T Blanc, F Bloom, P Ford, WT Nauenberg, U Olivas, A Rankin, P Roy, J Smith, JG van Hoek, WC Zhang, L Harton, JL Hu, T Soffer, A Toki, WH Wilson, RJ Zhang, J Altenburg, D Brandt, T Brose, J Colberg, T Dickopp, M Dubitzky, RS Hauke, A Lacker, HM Maly, E Muller-Pfefferkorn, R Nogowski, R Otto, S Schubert, KR Schwierz, R Spaan, B Wilden, L Bernard, D Bonneaud, GR Brochard, F Cohen-Tanugi, J T'Jampens, S Thiebaux, C Vasileiadis, G Verderi, M Anjomshoaa, A Bernet, R Khan, A Lavin, D Muheim, F Playfer, S Swain, JE Tinslay, J Falbo, M Borean, C Bozzi, C Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Falciai, D Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Bagnasco, S Buzzo, A Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Pastore, FC Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Morii, M Grenier, GJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Prell, S Rosenberg, EI Yi, J Davier, M Grosdidier, G Hocker, A Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Wormser, G Bionta, RM Brigljevic, V Lange, DJ van Bibber, K Wright, DM Bevan, AJ Fry, JR Gabathuler, E Gamet, R George, M Kay, M Payne, DJ Sloane, RJ Touramanis, C Aspinwall, ML Bowerman, DA Dauncey, PD Egede, U Eschrich, I Morton, GW Nash, JA Sanders, P Taylor, GP Back, JJ Bellodi, G Dixon, P Harrison, PF Shorthouse, HW Strother, P Vidal, PB Cowan, G Flaecher, HU George, S Green, MG Kurup, A Marker, CE McMahon, TR Ricciardi, S Salvatore, F Vaitsas, G Winter, MA Brown, D Davis, CL Allison, J Barlow, RJ Forti, AC Hart, PA Jackson, F Lafferty, GD Lyon, AJ Savvas, N Weatherall, JH Williams, JC Farbin, A Jawahery, A Lillard, V Roberts, DA Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Staengle, H Willocq, S Cowan, R Sciolla, G Taylor, F Yamamoto, RK Milek, M Patel, PM Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Kroeger, R Reidy, J Sanders, DA Summers, DJ Zhao, H Hast, C Taras, P Nicholson, H Cartaro, C Cavallo, N De Nardo, G Fabozzi, F Gatto, C Lista, L Paolucci, P Piccolo, D Sciacca, C LoSecco, JM Alsmiller, JRG Gabriel, TA Brau, B Brau, J Frey, R Iwasaki, M Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Tiozzo, G Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Del Buono, L Hamon, O Leruste, P Ocariz, J Pivk, M Roos, L Stark, J Manfredi, PF Re, V Speziali, V Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Campagna, E Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Triggiani, G Walsh, J Haire, M Judd, D Paick, K Turnbull, L Wagoner, DE Danielson, N Elmer, P Lu, C Miftakov, V Olsen, J Smith, AJS Tumanov, A Varnes, EW Bellini, F Cavoto, G del Re, D Faccini, R Ferrarotto, F Ferroni, F Gaspero, M Leonardi, E Mazzoni, MA Morganti, S Piredda, G Tehrani, FS Serra, M Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Olaiya, EO Xella, SM Aleksan, R Emery, S Gaidot, A Giraud, PF de Monchenault, GH Kozanecki, W Langer, M London, GW Mayer, B Schott, G Serfass, B Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Yumiceva, FX Abe, K Aston, D Bartoldus, R Berger, N Boyarski, AM Buchmueller, OL Convery, MR Coupal, DP Dong, D Dorfan, J Dunwoodie, W Field, RC Glanzman, T Gowdy, SJ Grauges-Pous, E Hadig, T Halyo, V Himel, T Hryn'ova, T Huffer, ME Innes, WR Jessop, CP Kelsey, MH Kim, P Kocian, ML Langenegger, U Leith, DWGS Luitz, S Luth, V Lynch, HL Marsiske, H Menke, S Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Ratcliff, BN Robertson, SH Roodman, A Salnikov, AA Schietinger, T Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Stelzer, J Su, D Sullivan, MK Tanaka, HA Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wright, DH Young, CC Burchat, PR Cheng, CH Meyer, TI Roat, C Bugg, W Krishnamurthy, M Spanier, SM Izen, JM Kitayama, I Lou, XC Bianchi, F Bona, M Gamba, D Bosisio, L Della Ricca, G Dittongo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Henderson, R Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Band, HR Dasu, S Datta, M Eichenbaum, AM Hu, H Johnson, JR Liu, R Di Lodovico, F Mohapatra, AK Pan, Y Prepost, R Sekula, SJ von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Neal, H AF Aubert, B Barate, R Boutigny, D Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Robbe, P Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kral, JF LeClerc, C Levi, ME Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Romosan, A Ronan, MT Shelkov, VG Telnov, AV Wenzel, WA Harrison, TJ Hawkes, CM Knowles, DJ O'Neale, SW Penny, RC Watson, AT Watson, NK Deppermann, T Goetzen, K Koch, H Lewandowski, B Pelizaeus, M Peters, K Schmuecker, H Steinke, M Barlow, NR Bhimji, W Boyd, JT Chevalier, N Clark, PJ Cottingham, WN Mackay, C Wilson, FF Hearty, C Mattison, TS McKenna, JA Thiessen, D Jolly, S Kyberd, P McKemey, AK Blinov, VE Bukin, AD Buzykaev, AR Golubev, VB Ivanchenko, VN Korol, AA Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Yushkov, AN Best, D Chao, M Kirkby, D Lankford, AJ Mandelkern, M McMahon, S Mommsen, RK Stoker, DP Buchanan, C Hadavand, HK Hill, EJ MacFarlane, DB Paar, HP Rahatlou, S Raven, G Schwanke, U Sharma, V Berryhill, JW Campagnari, C Dahmes, B Kuznetsova, N Levy, SL Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beringer, J Eisner, AM Grothe, M Heusch, CA Lockman, WS Pulliam, T Schalk, T Schmitz, RE Schumm, BA Seiden, A Turri, M Walkowiak, W Williams, DC Wilson, MG Albert, J Chen, E Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Narsky, I Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Barillari, T Blanc, F Bloom, P Ford, WT Nauenberg, U Olivas, A Rankin, P Roy, J Smith, JG van Hoek, WC Zhang, L Harton, JL Hu, T Soffer, A Toki, WH Wilson, RJ Zhang, J Altenburg, D Brandt, T Brose, J Colberg, T Dickopp, M Dubitzky, RS Hauke, A Lacker, HM Maly, E Muller-Pfefferkorn, R Nogowski, R Otto, S Schubert, KR Schwierz, R Spaan, B Wilden, L Bernard, D Bonneaud, GR Brochard, F Cohen-Tanugi, J T'Jampens, S Thiebaux, C Vasileiadis, G Verderi, M Anjomshoaa, A Bernet, R Khan, A Lavin, D Muheim, F Playfer, S Swain, JE Tinslay, J Falbo, M Borean, C Bozzi, C Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Falciai, D Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Bagnasco, S Buzzo, A Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Pastore, FC Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Morii, M Grenier, GJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Prell, S Rosenberg, EI Yi, J Davier, M Grosdidier, G Hocker, A Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Wormser, G Bionta, RM Brigljevic, V Lange, DJ van Bibber, K Wright, DM Bevan, AJ Fry, JR Gabathuler, E Gamet, R George, M Kay, M Payne, DJ Sloane, RJ Touramanis, C Aspinwall, ML Bowerman, DA Dauncey, PD Egede, U Eschrich, I Morton, GW Nash, JA Sanders, P Taylor, GP Back, JJ Bellodi, G Dixon, P Harrison, PF Shorthouse, HW Strother, P Vidal, PB Cowan, G Flaecher, HU George, S Green, MG Kurup, A Marker, CE McMahon, TR Ricciardi, S Salvatore, F Vaitsas, G Winter, MA Brown, D Davis, CL Allison, J Barlow, RJ Forti, AC Hart, PA Jackson, F Lafferty, GD Lyon, AJ Savvas, N Weatherall, JH Williams, JC Farbin, A Jawahery, A Lillard, V Roberts, DA Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Staengle, H Willocq, S Cowan, R Sciolla, G Taylor, F Yamamoto, RK Milek, M Patel, PM Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Kroeger, R Reidy, J Sanders, DA Summers, DJ Zhao, H Hast, C Taras, P Nicholson, H Cartaro, C Cavallo, N De Nardo, G Fabozzi, F Gatto, C Lista, L Paolucci, P Piccolo, D Sciacca, C LoSecco, JM Alsmiller, JRG Gabriel, TA Brau, B Brau, J Frey, R Iwasaki, M Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Tiozzo, G Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Del Buono, L Hamon, O Leruste, P Ocariz, J Pivk, M Roos, L Stark, J Manfredi, PF Re, V Speziali, V Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Campagna, E Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Triggiani, G Walsh, J Haire, M Judd, D Paick, K Turnbull, L Wagoner, DE Danielson, N Elmer, P Lu, C Miftakov, V Olsen, J Smith, AJS Tumanov, A Varnes, EW Bellini, F Cavoto, G del Re, D Faccini, R Ferrarotto, F Ferroni, F Gaspero, M Leonardi, E Mazzoni, MA Morganti, S Piredda, G Tehrani, FS Serra, M Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Olaiya, EO Xella, SM Aleksan, R Emery, S Gaidot, A Giraud, PF de Monchenault, GH Kozanecki, W Langer, M London, GW Mayer, B Schott, G Serfass, B Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Yumiceva, FX Abe, K Aston, D Bartoldus, R Berger, N Boyarski, AM Buchmueller, OL Convery, MR Coupal, DP Dong, D Dorfan, J Dunwoodie, W Field, RC Glanzman, T Gowdy, SJ Grauges-Pous, E Hadig, T Halyo, V Himel, T Hryn'ova, T Huffer, ME Innes, WR Jessop, CP Kelsey, MH Kim, P Kocian, ML Langenegger, U Leith, DWGS Luitz, S Luth, V Lynch, HL Marsiske, H Menke, S Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Ratcliff, BN Robertson, SH Roodman, A Salnikov, AA Schietinger, T Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Stelzer, J Su, D Sullivan, MK Tanaka, HA Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wright, DH Young, CC Burchat, PR Cheng, CH Meyer, TI Roat, C Bugg, W Krishnamurthy, M Spanier, SM Izen, JM Kitayama, I Lou, XC Bianchi, F Bona, M Gamba, D Bosisio, L Della Ricca, G Dittongo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Henderson, R Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Band, HR Dasu, S Datta, M Eichenbaum, AM Hu, H Johnson, JR Liu, R Di Lodovico, F Mohapatra, AK Pan, Y Prepost, R Sekula, SJ von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Neal, H CA BABAR Collaboration TI Measurement of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-ub vertical bar with B -> pe nu decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID B-MESON DECAYS; FORM-FACTORS AB We present a measurement of the branching fraction for the rare decays B-->rhoenu and extract a value for the magnitude of V-ub, one of the smallest elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are given for five different calculations of form factors used to parametrize the hadronic current in semileptonic decays. Using a sample of 55x10(6) B (B) over bar meson pairs recorded with the BABAR detector at the PEP-II e(+)e(-) storage ring, we obtain B(B-0-->rho(-)e(+)nu)=(3.29+/-0.42+/-0.47+/-0.55)x10(-4) and \V-ub\=(3.64+/-0.22+/-0.25(-0.56)(+0.39))x10(-3), where the uncertainties are statistical, systematic, and theoretical, respectively. C1 Phys Particules Lab, F-74941 Annecy Le Vieux, France. Univ Bari, Dipartmento Fis, I-70126 Bari, Italy. Univ Bari, Ist Nazl Fis Nucl, I-70126 Bari, Italy. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Bergen, Inst Phys, N-5007 Bergen, Norway. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Ruhr Univ Bochum, Inst Expt Phys 1, D-44780 Bochum, Germany. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ British Columbia, Vancouver, BC V6T 1Z1, Canada. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. CALTECH, Pasadena, CA 91125 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. Univ Colorado, Boulder, CO 80309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Tech Univ Dresden, Inst Kern & Teilchenphys, D-01062 Dresden, Germany. Ecole Polytech, LLR, F-91128 Palaiseau, France. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Elon Univ, Elon, NC 27244 USA. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. Univ Ferrara, Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Florida A&M Univ, Tallahassee, FL 32307 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Univ Genoa, Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Harvard Univ, Cambridge, MA 02138 USA. Univ Iowa, Iowa City, IA 52242 USA. Iowa State Univ, Ames, IA 50011 USA. Lab Accelerateur Lineaire, F-91898 Orsay, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Univ London Imperial Coll Sci Technol & Med, London SW7 2BW, England. Univ London, Queen Mary, London E1 4NS, England. Univ London Royal Holloway & Bedford New Coll, Egham TW20 0EX, Surrey, England. Univ Louisville, Louisville, KY 40292 USA. Univ Manchester, Manchester M13 9PL, Lancs, England. Univ Maryland, College Pk, MD 20742 USA. Univ Massachusetts, Amherst, MA 01003 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. McGill Univ, Montreal, PQ H3A 2T8, Canada. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Univ Milan, Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Mississippi, University, MS 38677 USA. Univ Montreal, Lab Rene JA Levesque, Montreal, PQ H3C 3J7, Canada. Mt Holyoke Coll, S Hadley, MA 01075 USA. Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy. Univ Naples Federico II, Ist Nazl Fis Nucl, I-80126 Naples, Italy. Univ Notre Dame, Notre Dame, IN 46556 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. Univ Padua, Ist Nazl Fis Nucl, I-35131 Padua, Italy. Univ Paris 06, Lab Phys Nucl HE, F-75252 Paris, France. Univ Paris 07, Lab Phys Nucl HE, F-75252 Paris, France. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. Univ Pavia, Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56010 Pisa, Italy. Scuola Normale Super Pisa, I-56010 Pisa, Italy. Prairie View A&M Univ, Prairie View, TX 77446 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Roma La Sapienza, Ist Nazl Fis Nucl, I-00185 Rome, Italy. Univ Rostock, D-18051 Rostock, Germany. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. Univ S Carolina, Columbia, SC 29208 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Stanford, CA 94305 USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Texas, Richardson, TX 75083 USA. Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, Italy. Univ Turin, Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy. Univ Trieste, Ist Nazl Fis Nucl, I-34127 Trieste, Italy. TRIUMF, Vancouver, BC V6T 2A3, Canada. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Victoria, Victoria, BC V8W 3P6, Canada. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. Univ Perugia, I-06100 Perugia, Italy. Univ Basilicata, I-85100 Potenza, Italy. RP Aubert, B (reprint author), Phys Particules Lab, F-74941 Annecy Le Vieux, France. RI Della Ricca, Giuseppe/B-6826-2013; Di Lodovico, Francesca/L-9109-2016; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016; Peters, Klaus/C-2728-2008; Bellini, Fabio/D-1055-2009; Sarti, Alessio/I-2833-2012; de Groot, Nicolo/A-2675-2009; Rotondo, Marcello/I-6043-2012; Neri, Nicola/G-3991-2012; Lista, Luca/C-5719-2008; Cavallo, Nicola/F-8913-2012; de Sangro, Riccardo/J-2901-2012; Patrignani, Claudia/C-5223-2009; Forti, Francesco/H-3035-2011; Monge, Maria Roberta/G-9127-2012; Kravchenko, Evgeniy/F-5457-2015; Mir, Lluisa-Maria/G-7212-2015; Martinez Vidal, F*/L-7563-2014; Kolomensky, Yury/I-3510-2015; Lo Vetere, Maurizio/J-5049-2012; Grancagnolo, Sergio/J-3957-2015; Lusiani, Alberto/N-2976-2015; Lusiani, Alberto/A-3329-2016; Morandin, Mauro/A-3308-2016; Bagnasco, Stefano/J-4324-2012 OI Della Ricca, Giuseppe/0000-0003-2831-6982; Di Lodovico, Francesca/0000-0003-3952-2175; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636; Peters, Klaus/0000-0001-7133-0662; Bellini, Fabio/0000-0002-2936-660X; Sarti, Alessio/0000-0001-5419-7951; Rotondo, Marcello/0000-0001-5704-6163; Neri, Nicola/0000-0002-6106-3756; de Sangro, Riccardo/0000-0002-3808-5455; Patrignani, Claudia/0000-0002-5882-1747; Forti, Francesco/0000-0001-6535-7965; Monge, Maria Roberta/0000-0003-1633-3195; Mir, Lluisa-Maria/0000-0002-4276-715X; Martinez Vidal, F*/0000-0001-6841-6035; Kolomensky, Yury/0000-0001-8496-9975; Lo Vetere, Maurizio/0000-0002-6520-4480; Grancagnolo, Sergio/0000-0001-8490-8304; Lusiani, Alberto/0000-0002-6876-3288; Lusiani, Alberto/0000-0002-6876-3288; Morandin, Mauro/0000-0003-4708-4240; NR 21 TC 15 Z9 15 U1 0 U2 5 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 MAY 9 PY 2003 VL 90 IS 18 AR 181801 DI 10.1103/PhysRevLett.90.181801 PG 7 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900006 ER PT J AU Aubert, B Boutigny, D Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Robbe, P Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kral, JF LeClerc, C Levi, ME Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Romosan, A Ronan, MT Shelkov, VG Telnov, AV Wenzel, WA Harrison, TJ Hawkes, CM Knowles, DJ O'Neale, SW Penny, RC Watson, AT Watson, NK Deppermann, T Goetzen, K Koch, H Lewandowski, B Peters, K Schmuecker, H Steinke, M Barlow, NR Bhimji, W Boyd, JT Chevalier, N Clark, PJ Cottingham, WN Mackay, C Wilson, FF Abe, K Hearty, C Mattison, TS McKenna, JA Thiessen, D Jolly, S McKemey, AK Blinov, VE Bukin, AD Buzykaev, AR Golubev, VB Ivanchenko, VN Korol, AA Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Yushkov, AN Best, D Chao, M Kirkby, D Lankford, AJ Mandelkern, M McMahon, S Stoker, DP Buchanan, C Chun, S Hadavand, HK Hill, EJ MacFarlane, DB Paar, H Prell, S Rahatlou, S Raven, G Schwanke, U Sharma, V Berryhill, JW Campagnari, C Dahmes, B Hart, PA Kuznetsova, N Levy, SL Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beringer, J Eisner, AM Grothe, M Heusch, CA Lockman, WS Pulliam, T Schalk, T Schmitz, RE Schumm, BA Seiden, A Turri, M Walkowiak, W Williams, DC Wilson, MG Chen, E Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Barillari, T Bloom, P Ford, WT Nauenberg, U Olivas, A Rankin, P Roy, J Smith, JG van Hoek, WC Zhang, L Harton, JL Hu, T Krishnamurthy, M Soffer, A Toki, WH Wilson, RJ Zhang, J Altenburg, D Brandt, T Brose, J Colberg, T Dickopp, M Dubitzky, RS Hauke, A Maly, E Muller-Pfefferkorn, R Otto, S Schubert, KR Schwierz, R Spaan, B Wilden, L Bernard, D Bonneaud, GR Brochard, F Cohen-Tanugi, J Ferrag, S T'Jampens, S Thiebaux, C Vasileiadis, G Verderi, M Anjomshoaa, A Bernet, R Khan, A Lavin, D Muheim, F Playfer, S Swain, JE Tinslay, J Falbo, M Borean, C Bozzi, C Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Falciai, D Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Bagnasco, S Buzzo, A Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Pastore, FC Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Morii, M Bartoldus, R Grenier, GJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Rosenberg, EI Yi, J Davier, M Grosdidier, G Hocker, A Lacker, HM Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Trincaz-Duvoid, S Wormser, G Bionta, RM Brigljevic, V Lange, DJ van Bibber, K Wright, DM Bevan, AJ Fry, JR Gabathuler, E Gamet, R George, M Kay, M Payne, DJ Sloane, RJ Touramanis, C Aspinwall, ML Bowerman, DA Dauncey, PD Egede, U Eschrich, I Morton, GW Nash, JA Sanders, P Smith, D Taylor, GP Back, JJ Bellodi, G Dixon, P Harrison, PF Potter, RJL Shorthouse, HW Strother, P Vidal, PB Cowan, G Flaecher, HU George, S Green, MG Kurup, A Marker, CE McMahon, TR Ricciardi, S Salvatore, F Vaitsas, G Winter, MA Brown, D Davis, CL Allison, J Barlow, RJ Forti, AC Jackson, F Lafferty, GD Lyon, AJ Savvas, N Weatherall, JH Williams, JC Farbin, A Jawahery, A Lillard, V Roberts, DA Schieck, JR Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Staengle, H Willocq, S Brau, B Cowan, R Sciolla, G Taylor, F Yamamoto, RK Milek, M Patel, PM Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Kroeger, R Reidy, J Sanders, DA Summers, DJ Hast, C Taras, P Nicholson, H Cartaro, C Cavallo, N De Nardo, G Fabozzi, F Gatto, C Lista, L Paolucci, P Piccolo, D Sciacca, C LoSecco, JM Alsmiller, JRG Gabriel, TA Brau, J Frey, R Iwasaki, M Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Del Buono, L Hamon, O Leruste, P Ocariz, J Pivk, M Roos, L Stark, J Manfredi, PF Re, V Speziali, V Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Campagna, E Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Triggiani, G Walsh, J Haire, M Judd, D Paick, K Turnbull, L Wagoner, DE Albert, J Danielson, N Elmer, P Lu, C Miftakov, V Olsen, J Schaffner, SF Smith, AJS Tumanov, A Varnes, EW Bellini, F Cavoto, G del Re, D Faccini, R Ferrarotto, F Ferroni, F Leonardi, E Mazzoni, MA Morganti, S Piredda, G Tehrani, FS Serra, M Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Xella, SM Aleksan, R Emery, S Gaidot, A Giraud, PF de Monchenault, GH Kozanecki, W Langer, M London, GW Mayer, B Schott, G Serfass, B Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Yumiceva, FX Adam, I Aston, D Berger, N Boyarski, AM Convery, MR Coupal, DP Dong, D Dorfan, J Dunwoodie, W Field, RC Glanzman, T Gowdy, SJ Grauges, E Haas, T Hadig, T Halyo, V Himel, T Hryn'ova, T Huffer, ME Innes, WR Jessop, CP Kelsey, MH Kim, P Kocian, ML Langenegger, U Leith, DWGS Luitz, S Luth, V Lynch, HL Marsiske, H Menke, S Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Quinn, H Ratcliff, BN Robertson, SH Roodman, A Salnikov, AA Schietinger, T Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Spanier, SM Stelzer, J Su, D Sullivan, MK Tanaka, HA Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wright, DH Young, CC Burchat, PR Cheng, CH Meyer, TI Roat, C Henderson, R Bugg, W Cohn, H Izen, JM Kitayama, I Lou, XC Bianchi, F Bona, M Gamba, D Bosisio, L Della Ricca, G Dittongo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Band, HR Dasu, S Datta, M Eichenbaum, AM Hu, H Johnson, JR Liu, R Di Lodovico, F Mohapatra, A Pan, Y Prepost, R Scott, IJ Sekula, SJ von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Neal, H AF Aubert, B Boutigny, D Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Robbe, P Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kral, JF LeClerc, C Levi, ME Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Romosan, A Ronan, MT Shelkov, VG Telnov, AV Wenzel, WA Harrison, TJ Hawkes, CM Knowles, DJ O'Neale, SW Penny, RC Watson, AT Watson, NK Deppermann, T Goetzen, K Koch, H Lewandowski, B Peters, K Schmuecker, H Steinke, M Barlow, NR Bhimji, W Boyd, JT Chevalier, N Clark, PJ Cottingham, WN Mackay, C Wilson, FF Abe, K Hearty, C Mattison, TS McKenna, JA Thiessen, D Jolly, S McKemey, AK Blinov, VE Bukin, AD Buzykaev, AR Golubev, VB Ivanchenko, VN Korol, AA Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Yushkov, AN Best, D Chao, M Kirkby, D Lankford, AJ Mandelkern, M McMahon, S Stoker, DP Buchanan, C Chun, S Hadavand, HK Hill, EJ MacFarlane, DB Paar, H Prell, S Rahatlou, S Raven, G Schwanke, U Sharma, V Berryhill, JW Campagnari, C Dahmes, B Hart, PA Kuznetsova, N Levy, SL Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beringer, J Eisner, AM Grothe, M Heusch, CA Lockman, WS Pulliam, T Schalk, T Schmitz, RE Schumm, BA Seiden, A Turri, M Walkowiak, W Williams, DC Wilson, MG Chen, E Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Barillari, T Bloom, P Ford, WT Nauenberg, U Olivas, A Rankin, P Roy, J Smith, JG van Hoek, WC Zhang, L Harton, JL Hu, T Krishnamurthy, M Soffer, A Toki, WH Wilson, RJ Zhang, J Altenburg, D Brandt, T Brose, J Colberg, T Dickopp, M Dubitzky, RS Hauke, A Maly, E Muller-Pfefferkorn, R Otto, S Schubert, KR Schwierz, R Spaan, B Wilden, L Bernard, D Bonneaud, GR Brochard, F Cohen-Tanugi, J Ferrag, S T'Jampens, S Thiebaux, C Vasileiadis, G Verderi, M Anjomshoaa, A Bernet, R Khan, A Lavin, D Muheim, F Playfer, S Swain, JE Tinslay, J Falbo, M Borean, C Bozzi, C Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Falciai, D Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Bagnasco, S Buzzo, A Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Pastore, FC Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Morii, M Bartoldus, R Grenier, GJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Rosenberg, EI Yi, J Davier, M Grosdidier, G Hocker, A Lacker, HM Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Trincaz-Duvoid, S Wormser, G Bionta, RM Brigljevic, V Lange, DJ van Bibber, K Wright, DM Bevan, AJ Fry, JR Gabathuler, E Gamet, R George, M Kay, M Payne, DJ Sloane, RJ Touramanis, C Aspinwall, ML Bowerman, DA Dauncey, PD Egede, U Eschrich, I Morton, GW Nash, JA Sanders, P Smith, D Taylor, GP Back, JJ Bellodi, G Dixon, P Harrison, PF Potter, RJL Shorthouse, HW Strother, P Vidal, PB Cowan, G Flaecher, HU George, S Green, MG Kurup, A Marker, CE McMahon, TR Ricciardi, S Salvatore, F Vaitsas, G Winter, MA Brown, D Davis, CL Allison, J Barlow, RJ Forti, AC Jackson, F Lafferty, GD Lyon, AJ Savvas, N Weatherall, JH Williams, JC Farbin, A Jawahery, A Lillard, V Roberts, DA Schieck, JR Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Staengle, H Willocq, S Brau, B Cowan, R Sciolla, G Taylor, F Yamamoto, RK Milek, M Patel, PM Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Kroeger, R Reidy, J Sanders, DA Summers, DJ Hast, C Taras, P Nicholson, H Cartaro, C Cavallo, N De Nardo, G Fabozzi, F Gatto, C Lista, L Paolucci, P Piccolo, D Sciacca, C LoSecco, JM Alsmiller, JRG Gabriel, TA Brau, J Frey, R Iwasaki, M Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Del Buono, L Hamon, O Leruste, P Ocariz, J Pivk, M Roos, L Stark, J Manfredi, PF Re, V Speziali, V Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Campagna, E Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Triggiani, G Walsh, J Haire, M Judd, D Paick, K Turnbull, L Wagoner, DE Albert, J Danielson, N Elmer, P Lu, C Miftakov, V Olsen, J Schaffner, SF Smith, AJS Tumanov, A Varnes, EW Bellini, F Cavoto, G del Re, D Faccini, R Ferrarotto, F Ferroni, F Leonardi, E Mazzoni, MA Morganti, S Piredda, G Tehrani, FS Serra, M Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Xella, SM Aleksan, R Emery, S Gaidot, A Giraud, PF de Monchenault, GH Kozanecki, W Langer, M London, GW Mayer, B Schott, G Serfass, B Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Yumiceva, FX Adam, I Aston, D Berger, N Boyarski, AM Convery, MR Coupal, DP Dong, D Dorfan, J Dunwoodie, W Field, RC Glanzman, T Gowdy, SJ Grauges, E Haas, T Hadig, T Halyo, V Himel, T Hryn'ova, T Huffer, ME Innes, WR Jessop, CP Kelsey, MH Kim, P Kocian, ML Langenegger, U Leith, DWGS Luitz, S Luth, V Lynch, HL Marsiske, H Menke, S Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Quinn, H Ratcliff, BN Robertson, SH Roodman, A Salnikov, AA Schietinger, T Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Spanier, SM Stelzer, J Su, D Sullivan, MK Tanaka, HA Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wright, DH Young, CC Burchat, PR Cheng, CH Meyer, TI Roat, C Henderson, R Bugg, W Cohn, H Izen, JM Kitayama, I Lou, XC Bianchi, F Bona, M Gamba, D Bosisio, L Della Ricca, G Dittongo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Band, HR Dasu, S Datta, M Eichenbaum, AM Hu, H Johnson, JR Liu, R Di Lodovico, F Mohapatra, A Pan, Y Prepost, R Scott, IJ Sekula, SJ von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Neal, H TI Study of the rare decays B-0 -> D-s((*)+)pi(-) and B-0 -> Ds(*)-K+ SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP-VIOLATION; MESON SYSTEM; B-DECAYS; SEARCH AB We report evidence for the decays B-0-->D(s)(+)pi(-) and B-0-->Ds-K+ and the results of a search for B-0-->D*(+)(s)pi(-) and B-0-->D*K--(s)+ in a sample of 84x10(6) Y(4S) decays into B (B) over bar pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage ring. We measure the branching fractions B(B-0-->D(s)(+)pi(-))=[3.2+/-0.9(stat)+/-1.0(syst)]x10(-5) and B(B-0-->Ds-K+)=[3.2+/-1.0(stat)+/-1.0(syst)]x10(-5). We also set 90% C.L. limits B(B-0-->D*(+)(s)pi(-))<4.1x10(-5) and B(B-0-->D*K--(s)+)<2.5x10(-5). C1 Phys Particules Lab, F-74941 Annecy Le Vieux, France. Univ Bari, Dipartmento Fis, I-70126 Bari, Italy. Univ Bari, Ist Nazl Fis Nucl, I-70126 Bari, Italy. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Bergen, Inst Phys, N-5007 Bergen, Norway. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Ruhr Univ Bochum, Inst Expt Phys 1, D-44780 Bochum, Germany. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ British Columbia, Vancouver, BC V6T 1Z1, Canada. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. CALTECH, Pasadena, CA 91125 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. Univ Colorado, Boulder, CO 80309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Tech Univ Dresden, Inst Kern & Teilchenphys, D-01062 Dresden, Germany. Ecole Polytech, LLR, F-91128 Palaiseau, France. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Elon Univ, Elon College, NC 27244 USA. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. Univ Ferrara, Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Florida A&M Univ, Tallahassee, FL 32307 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Univ Genoa, Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Harvard Univ, Cambridge, MA 02138 USA. Univ Iowa, Iowa City, IA 52242 USA. Iowa State Univ, Ames, IA 50011 USA. Lab Accelerateur Lineaire, F-91898 Orsay, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Univ London Imperial Coll Sci Technol & Med, London SW7 2BW, England. Univ London, Queen Mary, London E1 4NS, England. Univ London Royal Holloway & Bedford New Coll, Egham TW20 0EX, Surrey, England. Univ Louisville, Louisville, KY 40292 USA. Univ Manchester, Manchester M13 9PL, Lancs, England. Univ Maryland, College Pk, MD 20742 USA. Univ Massachusetts, Amherst, MA 01003 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. McGill Univ, Montreal, PQ H3A 2T8, Canada. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Univ Milan, Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Mississippi, University, MS 38677 USA. Univ Montreal, Lab Rene JA Levesque, Montreal, PQ H3C 3J7, Canada. Mt Holyoke Coll, S Hadley, MA 01075 USA. Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy. Univ Naples Federico II, Ist Nazl Fis Nucl, I-80126 Naples, Italy. Univ Notre Dame, Notre Dame, IN 46556 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. Univ Padua, Ist Nazl Fis Nucl, I-35131 Padua, Italy. Univ Paris 06, Lab Phys Nucl HE, F-75252 Paris, France. Univ Paris 07, Lab Phys Nucl HE, F-75252 Paris, France. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. Univ Pavia, Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Scuola Normale Super Pisa, I-56010 Pisa, Italy. Univ Pisa, Ist Nazl Fis Nucl, I-56010 Pisa, Italy. Prairie View A&M Univ, Prairie View, TX 77446 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Roma La Sapienza, Ist Nazl Fis Nucl, I-00185 Rome, Italy. Univ Rostock, D-18051 Rostock, Germany. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. Univ S Carolina, Columbia, SC 29208 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Stanford, CA 94305 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. Univ Tennessee, Knoxville, TN 37996 USA. Univ Texas, Richardson, TX 75083 USA. Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, Italy. Univ Turin, Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy. Univ Trieste, Ist Nazl Fis Nucl, I-34127 Trieste, Italy. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Victoria, Victoria, BC V8W 3P6, Canada. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. Univ Perugia, I-06100 Perugia, Italy. RP Aubert, B (reprint author), Phys Particules Lab, F-74941 Annecy Le Vieux, France. RI Peters, Klaus/C-2728-2008; de Groot, Nicolo/A-2675-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; Schaffner, Stephen/D-1189-2011; Roe, Natalie/A-8798-2012; Neri, Nicola/G-3991-2012; Forti, Francesco/H-3035-2011; Rotondo, Marcello/I-6043-2012; de Sangro, Riccardo/J-2901-2012; Bagnasco, Stefano/J-4324-2012; Sarti, Alessio/I-2833-2012; Cavallo, Nicola/F-8913-2012; Patrignani, Claudia/C-5223-2009; Frey, Raymond/E-2830-2016; Monge, Maria Roberta/G-9127-2012; Kravchenko, Evgeniy/F-5457-2015; Mir, Lluisa-Maria/G-7212-2015; Martinez Vidal, F*/L-7563-2014; Kolomensky, Yury/I-3510-2015; Lo Vetere, Maurizio/J-5049-2012; Lusiani, Alberto/N-2976-2015; Lusiani, Alberto/A-3329-2016; Morandin, Mauro/A-3308-2016; Della Ricca, Giuseppe/B-6826-2013; Di Lodovico, Francesca/L-9109-2016; Calcaterra, Alessandro/P-5260-2015 OI Peters, Klaus/0000-0001-7133-0662; Bellini, Fabio/0000-0002-2936-660X; Neri, Nicola/0000-0002-6106-3756; Forti, Francesco/0000-0001-6535-7965; Rotondo, Marcello/0000-0001-5704-6163; de Sangro, Riccardo/0000-0002-3808-5455; Sarti, Alessio/0000-0001-5419-7951; Patrignani, Claudia/0000-0002-5882-1747; Frey, Raymond/0000-0003-0341-2636; Monge, Maria Roberta/0000-0003-1633-3195; Mir, Lluisa-Maria/0000-0002-4276-715X; Martinez Vidal, F*/0000-0001-6841-6035; Kolomensky, Yury/0000-0001-8496-9975; Lo Vetere, Maurizio/0000-0002-6520-4480; Lusiani, Alberto/0000-0002-6876-3288; Lusiani, Alberto/0000-0002-6876-3288; Morandin, Mauro/0000-0003-4708-4240; Della Ricca, Giuseppe/0000-0003-2831-6982; Di Lodovico, Francesca/0000-0003-3952-2175; Calcaterra, Alessandro/0000-0003-2670-4826 NR 17 TC 21 Z9 21 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 9 PY 2003 VL 90 IS 18 AR 181803 DI 10.1103/PhysRevLett.90.181803 PG 7 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900008 PM 12785999 ER PT J AU Beacom, JF Bell, NF Hooper, D Pakvasa, S Weiler, TJ AF Beacom, JF Bell, NF Hooper, D Pakvasa, S Weiler, TJ TI Decay of high-energy astrophysical neutrinos SO PHYSICAL REVIEW LETTERS LA English DT Article ID OSCILLATIONS; CONSTRAINTS; MODEL AB Existing limits on the nonradiative decay of one neutrino to another plus a massless particle (e.g., a singlet Majoron) are very weak. The best limits on the lifetime to mass ratio come from solar neutrino observations and are tau/mgreater than or similar to10(-4) s/eV for the relevant mass eigenstate(s). For lifetimes even several orders of magnitude longer, high-energy neutrinos from distant astrophysical sources would decay. This would strongly alter the flavor ratios from the phi(nu e):phi(nu mu):phi(nu tau)=1:1:1 expected from oscillations alone and should be readily visible in the near future in detectors such as IceCube. C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. KEK, Theory Grp, Tsukuba, Ibaraki 3050801, Japan. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. RP Beacom, JF (reprint author), Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. EM beacom@fnal.gov; nfb@fnal.gov; hooper@pheno.physics.wisc.edu; pakvasa@phys.hawaii.edu; tom.weiler@vanderbilt.edu OI Beacom, John/0000-0002-0005-2631 NR 30 TC 121 Z9 121 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 MAY 9 PY 2003 VL 90 IS 18 AR 181301 DI 10.1103/PhysRevLett.90.181301 PG 4 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900005 PM 12785996 ER PT J AU Eskildsen, MR Dewhurst, CD Hoogenboom, BW Petrovic, C Canfield, PC AF Eskildsen, MR Dewhurst, CD Hoogenboom, BW Petrovic, C Canfield, PC TI Hexagonal and square flux line lattices in CeCoIn5 SO PHYSICAL REVIEW LETTERS LA English DT Article ID D-WAVE SUPERCONDUCTORS; VORTEX LATTICE; FIELD; TRANSITION; YBA2CU3O7; SYMMETRY AB Using small-angle neutron scattering, we have imaged the magnetic flux line lattice (FLL) in the d-wave heavy-fermion superconductor CeCoIn5. At low fields we find a hexagonal FLL. Around 0.6 T this undergoes what is most likely a first-order transition to square symmetry, with the nearest neighbors oriented along the gap node directions. This orientation of the square FLL is consistent with theoretical predictions based on the d-wave order parameter symmetry. C1 Univ Geneva, Dept Phys Mat Condensee, CH-1211 Geneva 4, Switzerland. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Univ Geneva, Dept Phys Mat Condensee, 24 Quai E Ansermet, CH-1211 Geneva 4, Switzerland. EM morten.eskildsen@physics.unige.ch RI Petrovic, Cedomir/A-8789-2009; Eskildsen, Morten/E-7779-2011; Canfield, Paul/H-2698-2014 OI Petrovic, Cedomir/0000-0001-6063-1881; NR 31 TC 47 Z9 47 U1 2 U2 7 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 MAY 9 PY 2003 VL 90 IS 18 AR 187001 DI 10.1103/PhysRevLett.90.187001 PG 4 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900045 PM 12786036 ER PT J AU Feibelman, PJ AF Feibelman, PJ TI Reactive wetting: H2O/Rh(111) SO PHYSICAL REVIEW LETTERS LA English DT Article ID ABINITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; AUGMENTED-WAVE METHOD; ULTRASOFT PSEUDOPOTENTIALS; BASIS-SET; SURFACES; METALS; WATER; ICE; TRANSITION AB First-principles calculations imply that neither H2O bilayers nor half-dissociated, H2O+OH+H monolayers are thermodynamically stable on clean Rh(111). Thus, the experimental observation that Rh(111) supports a periodic 2D water adlayer needs an explanation. Chemistry involving common surface impurities, notably C atoms, may be the answer. Calculations show they provide favorable binding sites for H atoms detached from H2O. The resulting OH fragments can anchor a 2D water layer to the surface. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 31 TC 32 Z9 33 U1 1 U2 7 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 MAY 9 PY 2003 VL 90 IS 18 AR 186103 DI 10.1103/PhysRevLett.90.186103 PG 4 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900037 PM 12786028 ER PT J AU Lee, DR Shin, K Seeck, OH Kim, H Seo, YS Tolan, M Rafailovich, MH Sokolov, J Sinha, SK AF Lee, DR Shin, K Seeck, OH Kim, H Seo, YS Tolan, M Rafailovich, MH Sokolov, J Sinha, SK TI X-ray scattering from freestanding polymer films with geometrically curved surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID SMECTIC-A FILMS; DIFFUSE-SCATTERING; THERMAL FLUCTUATIONS; MULTILAYERS; ROUGHNESS AB We show that the x-ray surface scattering from a freestanding polymer film exhibits features that cannot be explained by the usual stochastic formalism for surfaces with random height fluctuations. Instead, a geometric description of the film morphology assuming two curved surfaces characterized by a radius of curvature and a lateral cutoff length successfully accounts for the phase difference between the Kiessig fringes of the nominal "specular" and "off-specular" components of the scattering. The formalism allows one to distinguish unambiguously between conformal and anticonformal curvature morphologies at long length scales. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Kwangju Inst Sci & Technol, Dept Mat Sci & Engn, Kwangju 500712, South Korea. Forschungszentrum Julich, IFF, D-52425 Julich, Germany. Sogang Univ, Dept Phys, Seoul 121742, South Korea. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Univ Dortmund, D-44221 Dortmund, Germany. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lee, DR (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RI Shin, Kwanwoo /C-4979-2012 NR 13 TC 7 Z9 7 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 9 PY 2003 VL 90 IS 18 AR 185503 DI 10.1103/PhysRevLett.90.185503 PG 4 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900029 PM 12786020 ER PT J AU Mo, SK Denlinger, JD Kim, HD Park, JH Allen, JW Sekiyama, A Yamasaki, A Kadono, K Suga, S Saitoh, Y Muro, T Metcalf, P Keller, G Held, K Eyert, V Anisimov, VI Vollhardt, D AF Mo, SK Denlinger, JD Kim, HD Park, JH Allen, JW Sekiyama, A Yamasaki, A Kadono, K Suga, S Saitoh, Y Muro, T Metcalf, P Keller, G Held, K Eyert, V Anisimov, VI Vollhardt, D TI Prominent quasiparticle peak in the photoemission spectrum of the metallic phase of V2O3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM MONTE-CARLO; INFINITE DIMENSIONS; ORBITAL OCCUPATION; VANADIUM-OXIDES; HUBBARD-MODEL; INSULATOR; SPECTROSCOPY; TRANSITIONS; VALENCE; SYSTEMS AB We present the first observation of a prominent quasiparticle peak in the photoemission spectrum of the metallic phase of V2O3 and report new spectral calculations that combine the local-density approximation with the dynamical mean-field theory (using quantum Monte Carlo simulations) to show the development of such a distinct peak with decreasing temperature. The experimental peak width and weight are significantly larger than in the theory. C1 Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Pohang Accelerator Lab, Pohang 790784, South Korea. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. Osaka Univ, Grad Sch Engn Sci, Dept Phys Mat, Osaka 5608531, Japan. Japan Atom Energy Res Inst, SPring8, Dept Synchrotron Radiat Res, Sayo, Hyogo 6795143, Japan. Japan Synchtrotron Radiat Res Inst, SPring8, Sayo, Hyogo 6795143, Japan. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Univ Augsburg, Ctr Elect Correlat & Magnetism, D-86135 Augsburg, Germany. Max Planck Inst Solid State Res, D-70569 Stuttgart, Germany. Inst Met Phys, Ekaterinburg, Russia. RP Mo, SK (reprint author), Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. RI Eyert, Volker/C-5968-2008; Mo, Sung-Kwan/F-3489-2013; Anisimov, Vladimir/K-1235-2013; Held, Karsten/O-4178-2015; Sekiyama, Akira/G-1851-2016 OI Mo, Sung-Kwan/0000-0003-0711-8514; Anisimov, Vladimir/0000-0002-1087-1956; Held, Karsten/0000-0001-5984-8549; NR 31 TC 117 Z9 117 U1 1 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 MAY 9 PY 2003 VL 90 IS 18 AR 186403 DI 10.1103/PhysRevLett.90.186403 PG 4 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900040 PM 12786031 ER PT J AU Sanchez, R van Milligen, BP Newman, DE Carreras, BA AF Sanchez, R van Milligen, BP Newman, DE Carreras, BA TI Quiet-time statistics of electrostatic turbulent fluxes from the JET tokamak and the W7-AS and TJ-II stellarators SO PHYSICAL REVIEW LETTERS LA English DT Article ID SELF-ORGANIZED-CRITICALITY; REVERSED-FIELD PINCH; PLASMA EDGE; EMPIRICAL SIMILARITY; TRANSPORT; FLUCTUATIONS; DYNAMICS; SYSTEMS; REGION; TORUS AB The statistics of the quiet times between successive turbulent flux bursts measured at the edge of the JET tokamak and the W7-AS and TJ-II stellarators are analyzed in search for evidence of self-organized critical behavior. The results obtained are consistent with what would be expected in the situation where the underlying plasma is indeed in a near critical state. C1 Univ Carlos III Madrid, Dept Fis, Madrid 28911, Spain. CIEMAT, Asociac EURATOM, Lab Nacl Fus, Madrid 28040, Spain. Univ Alaska Fairbanks, Dept Phys, Fairbanks, AK 99775 USA. Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. RP Sanchez, R (reprint author), Univ Carlos III Madrid, Dept Fis, Madrid 28911, Spain. RI Sanchez, Raul/C-2328-2008; van Milligen, Boudewijn/H-5121-2015 OI van Milligen, Boudewijn/0000-0001-5344-6274 NR 25 TC 53 Z9 53 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 MAY 9 PY 2003 VL 90 IS 18 AR 185005 DI 10.1103/PhysRevLett.90.185005 PG 4 WC Physics, Multidisciplinary SC Physics GA 677TP UT WOS:000182823900024 PM 12786015 ER PT J AU DePaolo, DJ Manga, M AF DePaolo, DJ Manga, M TI Deep origin of hotspots - The mantle plume model SO SCIENCE LA English DT Editorial Material ID GENERATION; CORE C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP DePaolo, DJ (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. RI Manga, Michael/D-3847-2013; OI Manga, Michael/0000-0003-3286-4682 NR 16 TC 55 Z9 61 U1 4 U2 9 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 MAY 9 PY 2003 VL 300 IS 5621 BP 920 EP 921 DI 10.1126/science.1083623 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 675WD UT WOS:000182719800036 PM 12738844 ER PT J AU Dai, X Savrasov, SY Kotliar, G Migliori, A Ledbetter, H Abrahams, E AF Dai, X Savrasov, SY Kotliar, G Migliori, A Ledbetter, H Abrahams, E TI Calculated phonon spectra of plutonium at high temperatures SO SCIENCE LA English DT Article ID ELECTRONIC-STRUCTURE; DELTA-PU; METALS; APPROXIMATION; TRANSITION; SYSTEMS AB We constructed computer-based simulations of the lattice dynamical properties of plutonium using an electronic structure method, which incorporates correlation effects among the f-shell electrons and calculates phonon spectra at arbitrary wavelengths. Our predicted spectrum for the face-centered cubic delta phase agrees well with experiments in the elastic limit and explains unusually large shear anisotropy of this material. The spectrum of the body-centered cubic phase shows an instability at zero temperature over a broad region of the wave vectors, indicating that this phase is highly anharmonic and can be stabilized at high temperatures by its phonon entropy. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Rutgers State Univ, Ctr Mat Theory, Piscataway, NJ 08854 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Savrasov, SY (reprint author), New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. EM savrasov@oak.njit.edu RI Dai, Xi/C-4236-2008; Savrasov, Sergey/M-7157-2015 OI Dai, Xi/0000-0003-0538-1829; NR 28 TC 177 Z9 177 U1 4 U2 24 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAY 9 PY 2003 VL 300 IS 5621 BP 953 EP 955 DI 10.1126/science.1083428 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 675WD UT WOS:000182719800048 PM 12738856 ER PT J AU Yu, EW McDermott, G Zgurskaya, HI Nikaido, H Koshland, DE AF Yu, EW McDermott, G Zgurskaya, HI Nikaido, H Koshland, DE TI Structural basis of multiple drug-binding capacity of the AcrB multidrug efflux pump SO SCIENCE LA English DT Article ID LARGE PERIPLASMIC LOOPS; GRAM-NEGATIVE BACTERIA; ESCHERICHIA-COLI; SUBSTRATE-SPECIFICITY; RESISTANCE; TRANSPORTER; RECOGNITION; MECHANISMS AB Multidrug efflux pumps cause serious problems in cancer chemotherapy and treatment of bacterial infections. Yet high-resolution structures of ligand-transporter complexes have previously been unavailable. We obtained x-ray crystallographic structures of the trimeric AcrB pump from Escherichia coli with four structurally diverse ligands. The structures show that three molecules of ligands bind simultaneously to the extremely large central cavity of 5000 cubic angstroms, primarily by hydrophobic, aromatic stacking and van der Waals interactions. Each ligand uses a slightly different subset of AcrB residues for binding. The bound ligand molecules often interact with each other, stabilizing the binding. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Ctr Struct Biol, Berkeley, CA 94720 USA. RP Koshland, DE (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 229 Stanley Hall, Berkeley, CA 94720 USA. FU NIAID NIH HHS [AI 09644] NR 21 TC 274 Z9 289 U1 3 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 MAY 9 PY 2003 VL 300 IS 5621 BP 976 EP 980 DI 10.1126/science.1083137 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 675WD UT WOS:000182719800056 PM 12738864 ER PT J AU Kemeny, AE Francisco, JS Dixon, DA Feller, D AF Kemeny, AE Francisco, JS Dixon, DA Feller, D TI Accurate ab initio study of the energetics of phosphorus nitride: Heat of formation, ionization potential, and electron affinity SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; CONFIGURATION-INTERACTION CALCULATIONS; DIATOMIC DISSOCIATION-ENERGIES; WAVE-FUNCTIONS; BENCHMARK CALCULATIONS; TRIPLE EXCITATIONS; PN MOLECULE; INFRARED-SPECTRUM; HIGH-RESOLUTION AB High level ab initio electronic structure calculations at the coupled cluster CCSD(T) level with augmented correlation-consistent basis sets extrapolated to the complete basis set limit have been performed on PN, PN+, and PN-. The geometries were optimized up through the aug-cc-pV5Z level and vibrational frequencies were calculated with the aug-cc-pVQZ basis set. The heat of formation of PN at 0 K is predicted to be 43.7+/-0.9 kcal/mol and is within the error limits of the revised experimental value at 41.2+/-3.6 kcal/mol. The calculated adiabatic ionization potential is 11.90+/-0.05 eV as compared to the experimental value of 11.88+/-0.01 eV and the calculated adiabatic electron affinity is 0.126+/-0.01 eV as compared to the experimental value of 0.32+/-0.20 eV. (C) 2003 American Institute of Physics. C1 Purdue Univ, Dept Chem, W Lafayette, IN 47906 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47906 USA. Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Kemeny, AE (reprint author), Purdue Univ, Dept Chem, W Lafayette, IN 47906 USA. NR 65 TC 16 Z9 16 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 8 PY 2003 VL 118 IS 18 BP 8290 EP 8295 DI 10.1063/1.1565317 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 671FF UT WOS:000182454100021 ER PT J AU Sigman, ME Read, S Barbas, JT Ivanov, I Hagmann, EW Buchanan, AC Dabestani, R Kidder, MK Britt, PF AF Sigman, ME Read, S Barbas, JT Ivanov, I Hagmann, EW Buchanan, AC Dabestani, R Kidder, MK Britt, PF TI Rapid molecular motion of pyrene and benzene moieties covalently attached to silica surfaces SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MODEL COMPOUNDS; REARRANGEMENT; PYROLYSIS; PATHWAYS; ETHER; NMR AB Remarkably large rotational diffusion rates have been determined for silica-attached 1-pyrene at the solid/air interface through time-dependent fluorescence anisotropy measurements. Diffusion rates D-parallel to and D-perpendicular to were determined to be 4 x 10(6) and 2 x 10(6) s(-1), respectively, by treating the motion of the attached moiety as an oblate ellipsoid of rotation. C-13 NMR measurements on solid, silica-attached benzene-1-C-13, acquired using conventional solution NMR methods, gave remarkable, high-resolution spectra. A lower limit for the rate of phenyl group motion was estimated to be 1.5 x 10(5) s(-1), consistent with the fluorescence anisotropy data measured for silica-attached 1-pyrene. Molecular mechanics models for phenyl attached to representative silanol surfaces predict rotational barriers for phenyl rotations in the 2-5 kcal/mol range. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Hagmann, EW (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. RI ivanov, ilia/D-3402-2015 OI ivanov, ilia/0000-0002-6726-2502 NR 19 TC 6 Z9 7 U1 0 U2 1 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 MAY 8 PY 2003 VL 107 IS 18 BP 3450 EP 3456 DI 10.1021/jp022045n PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 676BV UT WOS:000182732800038 ER PT J AU Zhan, CG Dixon, DA AF Zhan, CG Dixon, DA TI The nature and absolute hydration free energy of the solvated electron in water SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Review ID MOLECULAR-DYNAMICS SIMULATION; REACTION FIELD-THEORY; DIPOLE-BOUND ANIONS; POLARIZABLE CONTINUUM MODEL; INTEGRAL-EQUATION FORMALISM; DENSITY-FUNCTIONAL THEORY; RESONANCE RAMAN-SPECTRA; CARBOXYLIC-ACID ESTERS; GAUSSIAN-BASIS SETS; 2 STRUCTURAL FORMS AB We report the first first-principles solvation-included electronic structure study to energetically compare a variety of candidate structures of the hydrated electron and to determine its absolute hydration free energy DeltaG(hyd)(298)(e(-)). The calculated results show that both the thermal motion and bulk solvent effects can qualitatively change the relative thermodynamic stability of different structures of the hydrated electron on the basis of a cluster of a given size, and that the most stable structure in solution is not necessarily the most stable one in the gas phase. For a given number of explicitly included solvent water molecules, the most stable structure in solution reveals a unique feature of the chemical nature of the solvated electron in water, i.e., the electron forms two strong electron-hydrogen bonds of the e(-)...HO type with the hydrogen-bonded water cluster and two of the hydrogen bonds in the neutral water cluster are broken. On the basis of the most stable structures, the calculated electronic excitation energies are within the observed absorption range of the hydrated electron in water. The absolute hydration free energy of the solvated electron in water has been calculated to be -35.5 kcal/mol by using a reliable computational protocol of first-principles solvation-included electronic structure calculations. This value is in excellent agreement with a recently obtained value of -34.6 kcal/mol. The predicted DeltaG(hyd)(298)(e(-)) value of -35.5 kcal/mol, when combined with our previously predicted DeltaG(hyd)(298)(H+) value of -262.4 kcal/mol and AG(hyd)(298)(HO-) value of -104.5 kcal/mol by using the same computational protocol, gives DeltaG(hyd)(298)(e(-)) + DeltaG(hyd)(298) H+) = -297.9 kcal/mol and DeltaG(hyd)(298)(e(-)) - DeltaG(hyd)(298)(HO-) = 69.0 kcal/mol, in excellent agreement with the corresponding values derived from experimental data. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Zhan, CG (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, MS K1-83,POB 999, Richland, WA 99352 USA. EM chang-guo.zhan@pnl.gov; david.dixon@pnl.gov NR 189 TC 76 Z9 78 U1 2 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 MAY 8 PY 2003 VL 107 IS 18 BP 4403 EP 4417 DI 10.1021/jp022326v PG 15 WC Chemistry, Physical SC Chemistry GA 676BX UT WOS:000182733000026 ER PT J AU Chekanov, S Krakauer, D Loizides, JH 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 Schioppa, M Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Ning, Y Paganis, S Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Stopa, P Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Kowal, M Kowalski, T Przybycien, M Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W 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, F 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, P Doyle, AT Glasman, C Hamilton, J Hanlon, S Lee, SW Lupi, A 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, A 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 Barbi, M Bertolin, A Corriveau, F Gliga, S Lainesse, J Padhi, S Stairs, DG Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V 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 Wiggers, 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, M 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 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 Krakauer, D Loizides, JH 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 Schioppa, M Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Ning, Y Paganis, S Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Stopa, P Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Kowal, M Kowalski, T Przybycien, M Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W 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, F 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, P Doyle, AT Glasman, C Hamilton, J Hanlon, S Lee, SW Lupi, A 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, A 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 Barbi, M Bertolin, A Corriveau, F Gliga, S Lainesse, J Padhi, S Stairs, DG Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V 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 Wiggers, 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, M 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 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 Scaling violations and determination of alpha(s) from jet production in gamma p interactions at HERA SO PHYSICS LETTERS B LA English DT Article ID DEEP-INELASTIC SCATTERING; CENTRAL TRACKING DETECTOR; LUND MONTE-CARLO; EP COLLIDER HERA; CROSS-SECTIONS; PARTON DISTRIBUTIONS; HADRON-COLLISIONS; PROTON COLLISIONS; QCD ANALYSIS; E+E-PHYSICS AB Differential cross sections for jet photoproduction in the reaction ep --> e jet X have been measured with the ZEUS detector at HERA using 82.2 pb(-1) of integrated luminosity. Inclusive jet cross sections are presented as a function of the jet transverse energy, E-T(jet), for jets with E-T(jet) > 17 GeV and pseudorapidity -1 < eta(jet) < 2.5, in the gammap centre-of-mass-energy range 142 < Wgammap < 293 GeV. Scaled jet invariant cross sections are presented as a function of the dimensionless variable x(T) equivalent to 2E(T)(jet)/W-gammap for (W-gammap) = 180 and 255 GeV: Next-to-leading-order QCD calculations give a good description of the measured differential cross sections in both magnitude and shape. The ratio of scaled jet invariant cross sections at the two (Wgammap) values shows clear non-scaling behaviour. A value for the strong coupling constant of alpha(s) (M-Z) = 0.1224 +/- 0.0001(stat.)(-0.0019)(+0.0022)(exp.)(-0.0042)(+0.0054)(th.) has been extracted from a QCD analysis of the measured dsigma/dE(T)(jet). The variation of sigma(s) with E-T(jet) is in good agreement with the running of sigma(s) as predicted by QCD. (C) 2003 Published by Elsevier Science B.V. 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, Irvington, NY 10027 USA. Inst Nucl Phys, Krakow, Poland. Univ Min & Met Krakow, Fac Phys & Nucl Tech, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, Deutsch Elektronen Synchrotron, Hamburg, Germany. DESY Zeuthen, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Freiburg, Fac Phys, Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Aegian, Dept Engn Management & Finance, Mitilini, Greece. Univ Hamburg, Inst Phys Expt, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Forschungszentrum Julich, Inst Kernphys, Julich, Germany. KEK, Inst Nucl & Particle Phys, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Kazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Kyungpook Natl Univ, Taegu 702701, South Korea. Autonomous Univ Madrid, Dept Fis Teor, E-28049 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 H, NL-1009 DB 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, 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. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM rik.yoshida@desy.de RI Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; De Pasquale, Salvatore/B-9165-2008; Gliga, Sebastian/K-4019-2015; 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; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Tassi, Enrico/K-3958-2015; 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; Wiggers, Leo/0000-0003-1060-0520; De Pasquale, Salvatore/0000-0001-9236-0748; Gliga, Sebastian/0000-0003-1729-1070; 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; Capua, Marcella/0000-0002-2443-6525; Arneodo, Michele/0000-0002-7790-7132; Gutsche, Oliver/0000-0002-8015-9622 NR 58 TC 36 Z9 36 U1 1 U2 2 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 MAY 8 PY 2003 VL 560 IS 1-2 BP 7 EP 23 DI 10.1016/S0370-2693(03)00380-0 PG 17 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 675CY UT WOS:000182676500002 ER PT J AU Djongolov, MK Hartley, DJ Riedinger, LL Kondev, FG Janssens, RVF Abu Saleem, K Ahmad, I Balabanski, DL Carpenter, MP Chowdhury, P Cullen, DM Danchev, M Dracoulis, GD El-Masri, H Goon, J Heinz, A Kaye, RA Khoo, TL Lauritsen, T Lister, CJ Moore, EF Riley, MA Seweryniak, D Shestakova, I Sletten, G Walker, PM Wheldon, C Wiedenhover, I Zeidan, O Zhang, JY AF Djongolov, MK Hartley, DJ Riedinger, LL Kondev, FG Janssens, RVF Abu Saleem, K Ahmad, I Balabanski, DL Carpenter, MP Chowdhury, P Cullen, DM Danchev, M Dracoulis, GD El-Masri, H Goon, J Heinz, A Kaye, RA Khoo, TL Lauritsen, T Lister, CJ Moore, EF Riley, MA Seweryniak, D Shestakova, I Sletten, G Walker, PM Wheldon, C Wiedenhover, I Zeidan, O Zhang, JY TI Extending the region of triaxial superdeformation: candidate TSD bands in Hf-174 SO PHYSICS LETTERS B LA English DT Article ID HIGH-SPIN; NUCLEI; EXCITATIONS; DEFORMATION; LU-163 AB Three, possibly four, regularly spaced rotational bands with large dynamic moments of inertia have been identified in Hf-174. Their properties are consistent with known triaxial superdeformed bands of the Lu/Hf region. Calculations predict substantial triaxial deformation (gamma approximate to +/-17) for Hf-174 structures with deformation epsilon(2) approximate to 0.45, despite the fact that Hf-174 is eight neutrons away from the previously established N = 94 triaxial superdeformed gap. Shell gaps at N = 100 and 106 with gamma greater than or equal to 15degrees are predicted for epsilon(2) approximate to 0.45, and are most likely responsible for the calculated TSD minima in Hf-174. (C) 2003 Published by Elsevier Science B.V C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Massachusetts, Dept Phys, Lowell, MA 01854 USA. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Australian Natl Univ, Dept Phys Nucl, Canberra, ACT 0200, Australia. Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. Purdue Univ Calumet, Dept Chem & Phys, Hammond, IN 46323 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. RP Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. EM hartley@usna.edu RI Dracoulis, George/A-8123-2008; Wheldon, Carl/F-9203-2013; Heinz, Andreas/E-3191-2014; Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 27 TC 38 Z9 39 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD MAY 8 PY 2003 VL 560 IS 1-2 BP 24 EP 30 DI 10.1016/S0370-2693(03)00328-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 675CY UT WOS:000182676500003 ER PT J AU Clatterbuck, DM Chrzan, DC Morris, JW AF Clatterbuck, DM Chrzan, DC Morris, JW TI The ideal strength of iron in tension and shear SO ACTA MATERIALIA LA English DT Article DE iron; mechanical properties; ideal strength; ab-initio electron theory; magnetic structure ID GENERALIZED-GRADIENT APPROXIMATION; ELECTRON-GAS; ULTRASOFT PSEUDOPOTENTIALS; GROUND-STATE; GAMMA-FE; WAVE; STABILITY; ENERGY; METALS; ACCURATE AB The ideal strength of a material is the stress at which the lattice itself becomes unstable and, hence, sets a firm upper bound on the mechanical strength the material can have. The present paper includes an ab-initio calculation of the ideal shear strength of Fe. It is, to our knowledge, the first such computation for any ferromagnetic material. The paper also elaborates on our earlier calculation of the ideal tensile strength of Fe by studying the effects of strains which break the tetragonal symmetry. The strengths were calculated using the Projector Augmented Wave Method within the framework of density functional theory and the generalized gradient approximation. In <001> tension the ideal strength is determined by an elastic instability of the ferromagnetic phase along the "Bain" strain path from bcc to fec. An <001> tensile strain also leads to instability with respect to transformation into a face centered orthorhombic structure, and to various magnetic instabilities. However, these are encountered at larger strains and, thus, do not affect the ideal strength. We also investigated the ideal shear strength of bcc iron in two prominent shear systems, <111> {112} and <111> {110}. In both shear systems the ideal strength is determined by the body centered tetragonal structure that defines a nearby saddle point on the energy surface. The ideal shear strengths are thus very similar, though they are not identical since the two shears follow slightly different strain paths from bcc to bct. We investigated the magnetic instabilities encountered during <111> {112} shear. These instabilities do not appear until the strain is significantly greater than the instability strain of the ferromagnetic crystal. Hence while Fe exhibits some novel effects due to magnetism, they do not affect the ideal strength, which is determined by the same elastic instabilities that determine the strengths of most other bee metals. Published by Elsevier Science Ltd on behalf of Acta Materialia Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RP Clatterbuck, DM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. NR 42 TC 125 Z9 129 U1 3 U2 46 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 MAY 7 PY 2003 VL 51 IS 8 BP 2271 EP 2283 DI 10.1016/S1359-6454(03)00033-8 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 669GB UT WOS:000182342600012 ER PT J AU Bordallo, HN Kolesnikov, AI Kolomiets, AV Kalceff, W Nakotte, H Eckert, J AF Bordallo, HN Kolesnikov, AI Kolomiets, AV Kalceff, W Nakotte, H Eckert, J TI Inelastic neutron scattering studies of TbNiALH(1.4) and UNiAlH2.0 hydrides SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID CRYSTAL-STRUCTURE; MAGNETIC-PROPERTIES; TRIPHONONS AB The optical vibrations of hydrogen in TbNiAlH1.4 and UNiAlH2.0 were investigated by means of inelastic neutron scattering. The experimental data were analysed, including multiphonon neutron scattering contributions, calculated in an isotropic harmonic approximation. At least two fundamental H optical peaks were observed in TbNiAlH1.4, and were assigned to the vibrational modes of hydrogen atoms occupying different interstitial sites in the metal sublattice. The high-energy part of the UNiAlH2.0 spectra is characterized by strong anharmonicity, and a broad fundamental band. The latter can be accounted for by a large dispersion of phonon modes due to the strong H-H interactions, and/or different metal-hydrogen force constants, which may originate from different metal atoms surrounding the H atoms in the unit cell. C1 Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Charles Univ, Dept Elect Struct, Prague 12116 2, Czech Republic. Univ Technol Sydney, Dept Appl Phys, Sydney, NSW 2007, Australia. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. RP Bordallo, HN (reprint author), Hahn Meitner Inst Berlin GmbH, SF-1,Glienicker Str,100, D-14109 Berlin, Germany. RI Bordallo, Heloisa/I-6836-2012; Kolesnikov, Alexander/I-9015-2012 OI Bordallo, Heloisa/0000-0003-0750-0553; Kolesnikov, Alexander/0000-0003-1940-4649 NR 27 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAY 7 PY 2003 VL 15 IS 17 BP 2551 EP 2559 AR PII S0953-8984(03)57070-9 DI 10.1088/0953-8984/15/17/310 PG 9 WC Physics, Condensed Matter SC Physics GA 682BW UT WOS:000183071400014 ER PT J AU Babikov, D Kendrick, BK Walker, RB Schinke, R Pack, RT AF Babikov, D Kendrick, BK Walker, RB Schinke, R Pack, RT TI Quantum origin of an anomalous isotope effect in ozone formation SO CHEMICAL PHYSICS LETTERS LA English DT Article ID POTENTIAL-ENERGY SURFACE; RATE COEFFICIENTS; DISSOCIATION THRESHOLD; INTRAMOLECULAR THEORY; O-16-O-18 MIXTURES; HEAVY OZONE; RECOMBINATION; FRACTIONATION; DEPENDENCE; STATE AB Accurate quantum mechanical calculations of the (J = 0) energies and lifetimes of the metastable states of ozone on a new, accurate potential energy surface are reported. These are very relevant to a famous anomalous isotope effect in the reaction that forms ozone because of their role in the energy transfer mechanism, in which metastable ro-vibrational states of ozone are formed and then stabilized by collisions with a third body. The resulting spectrum of metastable states is very dense below the delta zero-point energy threshold and sparse above it. This gives a clear qualitative explanation of why the effect occurs. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Babikov, D (reprint author), Los Alamos Natl Lab, Div Theoret, Mail Stop B268, Los Alamos, NM 87545 USA. NR 28 TC 40 Z9 41 U1 0 U2 8 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 MAY 6 PY 2003 VL 372 IS 5-6 BP 686 EP 691 DI 10.1016/S0009-2614(03)00479-2 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 677EZ UT WOS:000182795100013 ER PT J AU Xu, HW Su, YL Balmer, ML Navrotsky, A AF Xu, HW Su, YL Balmer, ML Navrotsky, A TI A new series of oxygen-deficient perovskites in the NaTi(x)Nb(1-x)O(3-0.5x) system: Synthesis, crystal chemistry, and energetics SO CHEMISTRY OF MATERIALS LA English DT Article ID OCTAHEDRAL MOLECULAR-SIEVES; EFFECTIVE IONIC-RADII; SOFT-PHONON MODES; SODIUM NIOBATE; PHASE-TRANSITIONS; DEGREES-C; PROFILE REFINEMENT; LATTICE-PARAMETERS; ROOM-TEMPERATURE; LITHIUM-NIOBATE AB A series of perovskites with the compositions NaTi(x)Nb(1-x)O(3-0.5x) (0 less than or equal to x less than or equal to 0.2) has been synthesized for the first time using the sol-gel method. Combined Rietveld analysis of powder neutron and X-ray diffraction data reveals that these phases adopt the structure of the end member perovskite NaNbO(3) with the space group Pbrna. However, the substituted structure is deficient in oxygen over its O1 and O3 sites, which compensates the charge imbalance between the substituting Ti(4+) and Nb(5+). Raman spectroscopy indicates that the O(2-) vacancies are locally associated with Ti4+, resulting in [TiO(5)] coordination. There is no evidence for long-range order or superstructure. With increasing Ti content, the orthorhombic structure becomes more like the cubic, as reflected by the smaller differences among its cell parameters (a(p), bp, and cp) and the cell angle beta(p) approaching 90degrees (in terms of the pseudocubic subcell). Enthalpies of formation from the oxides and from the elements have been determined by drop solution calorimetry into molten 3Na(2)O.4MoO(3) solvent at 974 K. As Ti(4+) substitutes for Nb(5+), the formation enthalpies become less exothermic, suggesting a destabilizing effect of the substitution. We attribute this behavior to a number of structural factors, including the occurrence of O(2-) vacancies and of Ti-O-Nb linkages as well as the size mismatch between Ti(4+) and Nb(5+). C1 Univ Calif Davis, Davis, CA 95616 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Xu, HW (reprint author), Univ Calif Davis, Davis, CA 95616 USA. NR 37 TC 22 Z9 22 U1 2 U2 14 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 MAY 6 PY 2003 VL 15 IS 9 BP 1872 EP 1878 DI 10.1021/cm020963s PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 674MZ UT WOS:000182641700016 ER EF