FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Kahn, JR O'Neill, RV AF Kahn, JR O'Neill, RV TI Ecological interaction as a source of economic irreversibility SO SOUTHERN ECONOMIC JOURNAL LA English DT Article ID BENEFIT-COST-ANALYSIS; PRESERVATION; VALUATION AB Irreversibility can be either physical or economic in origin. For example, the extinction of a species is physically irreversible. On the other hand, contamination of lake-bottom sediments by mercury is not physically irreversible (the mercury and/or sediments can be physically removed), but the cost is so high that it can be said to be economically irreversible. This paper argues that economic irreversibility associated with environmental change is much more common than typically discussed in the economics literature. The source of the problem is the inherent complexity of ecological relationships. The paper discusses the origin and policy importance of these indirect irreversibilities. C1 Univ Tennessee, Dept Econ, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Kahn, JR (reprint author), Univ Tennessee, Dept Econ, 534 Stokely Management Ctr, Knoxville, TN 37996 USA. NR 42 TC 12 Z9 12 U1 0 U2 1 PU UNIV NORTH CAROLINA PI CHAPEL HILL PA SOUTHERN ECONOMIC JOURNAL, CHAPEL HILL, NC 27514 USA SN 0038-4038 J9 SOUTHERN ECON J JI South. Econ. J. PD OCT PY 1999 VL 66 IS 2 BP 391 EP 402 DI 10.2307/1061150 PG 12 WC Economics SC Business & Economics GA 247AA UT WOS:000083197400011 ER PT J AU Bastasz, R Whaley, JA Ellis, WP AF Bastasz, R Whaley, JA Ellis, WP TI The energy and angular distributions of low-energy He+ scattered from Al(111) SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 6th International Conference on the Structure of Surfaces (ICSOS-6) CY JUL 26-30, 1999 CL UNIV BRITISH COLUMBIA, VANCOUVER, CANADA SP Univ British Columbia HO UNIV BRITISH COLUMBIA ID AUGER NEUTRALIZATION; TRIPLET CONVERSION; METAL-SURFACES; IONS; DEEXCITATION; COLLISIONS; SINGLET AB Measurements of 500 eV(4)He(+) scattered from Al(111) surfaces provide detailed information about the scattering process and surface crystallography. We report various observations concerning collision inelasticity, multiple scattering, and shadow-cone focusing effects. A large inelastic energy loss of the scattered He+ is observed, which causes multiple-scattering events at oblique incidence angles to have energies below the elastic single-scattering energy. Inelastic He+ scattering from clean, ordered Al(111) shows interesting intensity variations as a function of azimuthal orientation and incidence angle. At a critical incidence angle, where the top edge of a shadow cone intersects a nearest-neighbor Al surface atom, the scattered ion intensity exhibits 60 degrees azimuthal periodicity. At a more glancing angle of incidence, a double-peaked structure appears. The scattered He+ intensity varies as a function of incidence angle, as expected from classical shadow cone calculations. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bastasz, R (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD OCT PY 1999 VL 6 IS 5 BP 605 EP 611 DI 10.1142/S0218625X99000561 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 300LQ UT WOS:000086254800006 ER PT J AU Nascimento, VB de Carvalho, VE de Castilho, CMC Soares, EA Bittencourt, C Woodruff, DP AF Nascimento, VB de Carvalho, VE de Castilho, CMC Soares, EA Bittencourt, C Woodruff, DP TI The simulated annealing global search algorithm applied to the crystallography of surfaces by LEED SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 6th International Conference on the Structure of Surfaces (ICSOS-6) CY JUL 26-30, 1999 CL UNIV BRITISH COLUMBIA, VANCOUVER, CANADA SP Univ British Columbia HO UNIV BRITISH COLUMBIA ID ENERGY-ELECTRON-DIFFRACTION; STRUCTURAL-ANALYSIS; TENSOR LEED; OPTIMIZATION AB Surface structure determination by Low Energy Electron Diffraction (LEED) is based on a comparison between experimentally measured and theoretically calculated intensity versus energy I(V) curves for the diffracted beams. The level of agreement between these, for different structural models, is quantified using a correlation function, the so-called R factor. Minimizing this factor allows one to choose the best structure for which the theoretical simulations are computed. Surface structure determination thus requires an exhaustive search of structural parameter space in order to minimize the R factor. This minimization is usually performed by the use of directed search methods, although they have serious limitations, most notably their inability to distinguish between false and real structures corresponding to local and global R factor minima. In this work we present the implementation of a global search method based on the simulated annealing algorithm, as suggested earlier by Rous, using the Van Hove and Tong standard LEED code and the results of its application to the determination of the structure of the Ag(lll) and CdTe(110) surfaces. Two different R factors, R-P and R-1, have been employed in the structural searches, and the statistical topographies of these two factors were studied. We have also implemented a variation of the simulated annealing algorithm (Fast Simulated Annealing) and applied it to these same two systems. Some preliminary results obtained with this algorithm were used to compare its performance with the original algorithm proposed by Rous. C1 Univ Fed Minas Gerais, Dept Fis, Inst Ciencias Exatas, BR-30123970 Belo Horizonte, MG, Brazil. UFBA, Inst Fis, BR-40210340 Salvador, BA, Brazil. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RP Nascimento, VB (reprint author), Univ Fed Minas Gerais, Dept Fis, Inst Ciencias Exatas, CP 702, BR-30123970 Belo Horizonte, MG, Brazil. RI de Castilho, Caio/B-9839-2013; Soares, Edmar/C-2303-2013; de Carvalho, Vagner/A-4583-2008; OI Bittencourt, Carla/0000-0002-3330-6693 NR 25 TC 5 Z9 5 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD OCT PY 1999 VL 6 IS 5 BP 651 EP 661 DI 10.1142/S0218625X99000639 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 300LQ UT WOS:000086254800013 ER PT J AU Pelhos, K Madey, TE Hannon, JB Kellogg, GL AF Pelhos, K Madey, TE Hannon, JB Kellogg, GL TI Nucleation and growth during faceting of the platinum-covered W(111) surface SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 6th International Conference on the Structure of Surfaces (ICSOS-6) CY JUL 26-30, 1999 CL UNIV BRITISH COLUMBIA, VANCOUVER, CANADA SP Univ British Columbia, Amer Vacuum Soc, Pacific NW Chapter, US DOE, Canadian Soc Chem, Div Surfaces Sci, Canadian Assoc Phys, Div Surfaces Sci, ELMITEC, Elsevier Sci, Int Union Pure & Appl Phys, Leybold, NRC, Natl Vacuum Technol, OCI, Vacuum Microengn, OMICRON, Phys Electr, SPECS, VG Sci HO UNIV BRITISH COLUMBIA ID ULTRATHIN METAL-FILMS; PD; ISLANDS; MICROSCOPY; REACTIVITY; ADSORPTION; OVERLAYERS; MONOLAYER; AU(111); PT(111) AB Low energy electron microscopy (LEEM) and scanning tunneling microscopy (STM) have been used to investigate the faceting of W(111) as induced by Pt. The atomically rough W(111) surface, when fully covered with a monolayer film of Pt and annealed to temperatures higher than similar to 750 K, experiences a significant morphological restructuring: the initially planar surface undergoes a faceting transition and forms three-sided pyramids with {211} faces. When Pt is dosed onto the heated surface, the transition from planar to faceted structure proceeds through the nucleation and growth of spatially separated faceted region, as shown by LEEM. STM reveals the atomic structure of the partially faceted surface, with large planar regions, dotted by clusters of pyramids of various sizes. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Rutgers State Univ, Surface Modificat Lab, Piscataway, NJ 08855 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Madey, TE (reprint author), Rutgers State Univ, Dept Phys & Astron, POB 849, Piscataway, NJ 08855 USA. EM madey@physics.rutgers.edu NR 33 TC 22 Z9 22 U1 0 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD OCT PY 1999 VL 6 IS 5 BP 767 EP 774 DI 10.1142/S0218625X99000779 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 300LQ UT WOS:000086254800027 ER PT J AU Van Hove, MA Hermann, K Watson, PR Rumble, J AF Van Hove, MA Hermann, K Watson, PR Rumble, J TI Greatly improved surface structure database - SSD version 3 SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 6th International Conference on the Structure of Surfaces (ICSOS-6) CY JUL 26-30, 1999 CL UNIV BRITISH COLUMBIA, VANCOUVER, CANADA SP Univ British Columbia HO UNIV BRITISH COLUMBIA AB SSD-3, the third version of the NIST Surface Structure Database, appeared in 1999 as a major update. A complete revision of the database and graphics software upgrades SSD to a Windows environment (MS Windows 95, 98 and NT). SSD-3 includes over 1100 structures published through the end of 1997. SSD is an interactive PC-based database of critically selected surface structures determined with a variety of experimental techniques. The data include not only atomic coordinates, bond lengths and bond angles, but also information about experimental preparation, measurement and analysis methods. The software provides advanced search and display facilities, as well as interactive three-dimensional color visualization and, analysis tools of great flexibility. In addition, the program can generate publication-quality color or gray-scale prints of any structure, with a host of user-selectable options (such as view angle, perspective, colors, ball and bond styles, and labels). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Fritz Haber Inst, Abt Theorie, D-14195 Berlin, Germany. Oregon State Univ, Dept Chem, Corvallis, OR 97330 USA. Natl Inst Stand & Technol, Stand Reference Data Program, Gaithersburg, MD 20899 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Mailstop 66-200, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 3 TC 3 Z9 3 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD OCT PY 1999 VL 6 IS 5 BP 805 EP 811 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 300LQ UT WOS:000086254800033 ER PT J AU Lucas, CA Markovic, NM Ross, PN AF Lucas, CA Markovic, NM Ross, PN TI Structural effects induced by CO adsorption on Pt-bimetallic surfaces SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 6th International Conference on the Structure of Surfaces (ICSOS-6) CY JUL 26-30, 1999 CL UNIV BRITISH COLUMBIA, VANCOUVER, CANADA SP Univ British Columbia HO UNIV BRITISH COLUMBIA ID SCANNING-TUNNELING-MICROSCOPY; X-RAY-SCATTERING; UNDERPOTENTIAL DEPOSITION; INFRARED-SPECTROSCOPY; ADSORBED BROMIDE; PT(111); CU; ELECTRODEPOSITION; COPPER; UPD AB Synchrotron surface X-ray scattering (SXS) studies have been performed during the coadsorption of metal adatoms and carbon monoxide on single crystal Pt surfaces in an electrochemical environment. As the applied electrode potential is the driving force behind adsorption, the electrochemical system is in chemical equilibrium, which results in a range of structural phenomena, such as mixing, segregation, compression and displacement. The mechanisms behind these effects are studied by monitoring the diffraction signals from ordered adsorbed metal and CO adlayers that occur on the Pt(111) and Pt(100) surfaces. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Lucas, CA (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. OI Lucas, Christopher/0000-0001-5743-3868 NR 20 TC 3 Z9 3 U1 0 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD OCT PY 1999 VL 6 IS 5 BP 917 EP 922 DI 10.1142/S0218625X99000986 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 300LQ UT WOS:000086254800048 ER PT J AU Wang, LQ Ferris, KF Skiba, PX Shultz, AN Baer, DR Engelhard, MH AF Wang, LQ Ferris, KF Skiba, PX Shultz, AN Baer, DR Engelhard, MH TI Interactions of liquid and vapor water with stoichiometric and defective TiO2(100) surfaces SO SURFACE SCIENCE LA English DT Article DE surface defects; titanium oxide; UPS; water; XPS ID HYDROXYLATED OXIDE SURFACES; CRYSTAL-SURFACES; ELECTRON-SPECTROSCOPY; ADSORPTION; H2O; TIO2; TIO2(001); RUTILE; DESORPTION; 250-K AB Interactions of both liquid and vapor water with stoichiometric (nearly defect-free) and defective TiO2(100) surfaces have been studied using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS). For an almost defect-free (100) 1 x 1 surface, water coverage was similar to 0.08 ML (1 ML = 7.36 x 10(14)/cm(2)) at 10(4) L exposure to low-vapor-pressure water, similar to 0.32 ML at 10(8) L exposure to higher-vapor-pressure water, and similar to 0.50 ML with liquid-water exposure, respectively. Defect intensities were greatly reduced after exposing defective surfaces to similar to 10(2) L low-vapor-pressure water. More significantly, electron-beam-induced defects were completely removed upon higher exposure (>10(4) L), while defects created by Ar+ bombardment were partially removed. The surface structural influence on defect reactivity has been examined by comparing the results obtained from both (100) and (110) surfaces. Defects on (100) surfaces were removed more readily than those on (110) surfaces. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Dept Mat, Richland, WA 99352 USA. Austin Peay State Univ, Clarksville, TN 37040 USA. Ft Lewis State Univ, Durango, CO 81301 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Wang, LQ (reprint author), Pacific NW Lab, Dept Mat, POB 999, Richland, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; Baer, Donald/J-6191-2013; OI Baer, Donald/0000-0003-0875-5961; Engelhard, Mark/0000-0002-5543-0812 NR 34 TC 31 Z9 31 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 1 PY 1999 VL 440 IS 1-2 BP 60 EP 68 DI 10.1016/S0039-6028(99)00677-9 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 243ZD UT WOS:000083026600012 ER PT J AU Gerasimov, MR Ashby, CR Gardner, EL Mills, MJ Brodie, JD Dewey, SL AF Gerasimov, MR Ashby, CR Gardner, EL Mills, MJ Brodie, JD Dewey, SL TI Gamma-vinyl GABA inhibits methamphetamine, heroin, or ethanol-induced increases in nucleus accumbens dopamine SO SYNAPSE LA English DT Article DE gamma vinyl-GABA; Vigabatrin; Sabril; addiction; methamphetamine; ethanol; heroin; microdialysis; positron emission tomography; dopamine ID VENTRAL TEGMENTAL AREA; IN-VIVO MICRODIALYSIS; POSITRON EMISSION TOMOGRAPHY; CONDITIONED PLACE PREFERENCE; FREELY MOVING RATS; EXTRACELLULAR DOPAMINE; OPIOID RECEPTORS; SUBSTANTIA-NIGRA; C-11 RACLOPRIDE; RELEASE AB We examined the acute effect of the irreversible GABA-transaminase inhibitor, gamma-vinyl GABA (GVG, Sabril(R), Vigabatrin(R)) on increases in nucleus accumbens (NAc) dopamine (DA) folio-wing acute administration of methamphetamine, heroin, or ethanol. Methamphetamine (2.5 mg/kg) produced a dose-dependent increase (2,700%) in NAc DA. GVG preadministration (300 or 600 mg/kg), however, inhibited this response by approximately 39 and 61%, respectively. The lower dose of methamphetamine (1.25 mg/kg), increased DA by 1,700%. This response was inhibited to a similar extent (44%) regardless of the GVG dose preadministered (300 or 600 mg/kg). in addition, heroin-induced increases in NAc DA (0.5 mg/kg, 170%) were inhibited or completely abolished by GVG (150 or 300 mg/kg, 65 and 100%, respectively). Finally, at half the dose necessary for heroin, GVG (150 mg/kg) also completely abolished ethanol-induced increases in NAc DA following a 0.25 g/kg challenge dose (140%). Taken with our previous findings using nicotine or cocaine as the challenge drug, these results indicate that GVG attenuates increases in NAc DA by a mechanism common to many drugs of abuse. However, it appears unlikely that an acute dose of GVG can completely inhibit increases in NAc DA following challenges with a drug whose mechanism of action is mediated primarily through the DA reuptake site. (C) 1999 Wiley-Liss, Inc. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. St Johns Univ, Dept Pharmaceut Hlth Sci, Jamaica, NY 11439 USA. Albert Einstein Coll Med, Dept Psychiat, Bronx, NY 10467 USA. Albert Einstein Coll Med, Dept Neurosci, Bronx, NY 10467 USA. Georgetown Univ, Sch Med, Dept Psychiat, Washington, DC USA. NYU, Sch Med, Dept Psychiat, New York, NY USA. RP Dewey, SL (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. FU NIDA NIH HHS [Y1-DA7047-01]; NIMH NIH HHS [MH49165]; PHS HHS [R2955155] NR 79 TC 68 Z9 68 U1 1 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-4476 J9 SYNAPSE JI Synapse PD OCT PY 1999 VL 34 IS 1 BP 11 EP 19 DI 10.1002/(SICI)1098-2396(199910)34:1<11::AID-SYN2>3.0.CO;2-5 PG 9 WC Neurosciences SC Neurosciences & Neurology GA 230TR UT WOS:000082266900002 PM 10459167 ER PT J AU Sousa, LJ AF Sousa, LJ TI Forest product industry partners with government on R&D projects (vol 82, pg 88, 1999) SO TAPPI JOURNAL LA English DT Correction C1 US DOE, Off Ind Technol, Washington, DC 20585 USA. RP Sousa, LJ (reprint author), US DOE, Off Ind Technol, Washington, DC 20585 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU TECH ASSN PULP PAPER IND INC PI NORCROSS PA 15 TECHNOLOGY PARK SOUTH, NORCROSS, GA 30092 USA SN 0734-1415 J9 TAPPI J JI TAPPI J. PD OCT PY 1999 VL 82 IS 10 BP 10 EP 10 PG 1 WC Materials Science, Paper & Wood SC Materials Science GA 244HE UT WOS:000083045100002 ER PT J AU Crease, RP AF Crease, RP TI Image and logic: A material culture of microphysics. SO TECHNOLOGY AND CULTURE LA English DT Book Review C1 SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Crease, RP (reprint author), SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD OCT PY 1999 VL 40 IS 4 BP 924 EP 925 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 250TT UT WOS:000083404800037 ER PT J AU Blau, PJ AF Blau, PJ TI In memory of Ralph Burton - teacher, scientist, engineer, entrepreneur SO TRIBOLOGY INTERNATIONAL LA English DT Biographical-Item C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Blau, PJ (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0301-679X J9 TRIBOL INT JI Tribol. Int. PD OCT PY 1999 VL 32 IS 10 BP 535 EP 535 PG 1 WC Engineering, Mechanical SC Engineering GA 295TD UT WOS:000085983200001 ER PT J AU Di Federico, V Neuman, SP Tartakovsky, DM AF Di Federico, V Neuman, SP Tartakovsky, DM TI Anisotropy, lacunarity, and upscaled conductivity and its autocovariance in multiscale random fields with truncated power variograms SO WATER RESOURCES RESEARCH LA English DT Article ID FRACTIONAL GAUSSIAN-NOISE; HYDRAULIC CONDUCTIVITY; STOCHASTIC INTERPOLATION; SUBSURFACE HYDROLOGY; SPATIAL VARIABILITY; SOLUTE TRANSPORT; AQUIFER; SCALE; HETEROGENEITY; DISTRIBUTIONS AB It has been shown by Di Federico and Neuman [1997, 1998a, b] that observed multiscale behaviors of subsurface fluid flow and transport variables can be explained within the context of a unified stochastic framework, which views hydraulic conductivity as a random fractal characterized by a power variogram. Such a random field is statistically nonhomogeneous but possesses homogeneous spatial increments. Di Federico and Neuman [1997] have demonstrated that the power variogram and associated spectra of a statistically isotropic fractal field can be constructed as a weighted integral from zero to infinity (an infinite hierarchy) of exponential or Gaussian variograms and spectra of mutually uncorrelated fields (modes) that are homogeneous and isotropic. We show in this paper that the same holds true when the field and its constituent modes are statistically anisotropic, provided the ratios between principal integral (spatial correlation) scales are the same for all modes. We then analyze the effect of filtering out (truncating) modes of low, high, and intermediate spatial frequency from this infinite hierarchy in the real and spectral domains. A low-frequency cutoff renders the truncated hierarchy homogeneous. The integral scales of the lowest- and highest-frequency cutoff modes are related to length scales of the sampling window (domain) and data support (sample volume), respectively. Taking the former to be proportional to the latter renders expressions for the integral scale and variance of the truncated field dependent on window and support scale (in a manner previously shown to be consistent with observations in the isotropic case). It also allows (in principle) bridging across scales at a specific locale, as well as among locales, by adopting either site-specific or generalized variogram parameters. The introduction of intermediate cutoffs allows us to account, in a straightforward manner, for lacunarity due to gaps in the multiscale hierarchy created by the absence of modes associated with discrete ranges of scales (for example, where textural and structural features are associated with distinct ranges of scale, such as fractures having discrete ranges of trace length and density, which dissect the rock into matrix blocks having corresponding ranges of sizes). We explore mathematically and graphically the effects that anisotropy and lacunarity have on the integral scale, variance, covariance, and spectra of a truncated fractal field. We then develop an expression for the equivalent hydraulic conductivity of a box-shaped porous block, embedded within a multiscale log hydraulic conductivity field, under mean-uniform flow. The block is larger than the support scale of the field but is smaller than a surrounding sampling window. Consequently, its equivalent hydraulic conductivity is a random variable whose variance and spatial autocorrelation function, conditioned on a known mean value of support-scale conductivity across the window, are given explicitly by our multiscale theory. C1 Univ Bologna, DISTART, I-40136 Bologna, Italy. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Univ Calif Los Alamos Natl Lab, Grp CIC19, Los Alamos, NM 87545 USA. RP Di Federico, V (reprint author), Univ Bologna, DISTART, I-40136 Bologna, Italy. RI Di Federico, Vittorio/D-1970-2012; Tartakovsky, Daniel/E-7694-2013 OI Di Federico, Vittorio/0000-0001-9554-0373; NR 39 TC 42 Z9 42 U1 1 U2 8 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 OCT PY 1999 VL 35 IS 10 BP 2891 EP 2908 PG 18 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 240NQ UT WOS:000082832400001 ER PT J AU Moridis, GJ Finsterle, S Heiser, J AF Moridis, GJ Finsterle, S Heiser, J TI Evaluation of alternative designs for an injectable subsurface barrier at the Brookhaven National Laboratory site, Long Island, New York SO WATER RESOURCES RESEARCH LA English DT Article ID MODEL AB Two alternative designs for the demonstration emplacement of a viscous liquid barrier (VLB) at the Brookhaven National Laboratory (BNL), Long Island, New York, are investigated by means of numerical simulation. The application of the VLB technology at the BNL site involved a surface-modified colloidal silica (CS), which gels upon addition of an appropriate electrolyte. Lance injection was used for the CS barrier emplacement. The lance injections occur in three stages: primary, secondary, and tertiary. The geometry of the barrier is based on the wedge model. The first design is based on optimization principles and determines the parameters that maximize uniformity and minimize permeability by minimizing an appropriate objective function while meeting the design criteria. These include a maximum hydraulic conductivity of 10(-7) cm/s and a minimum thickness of 1 m. The second design aims to meet the same criteria and reflects standard chemical grouting practices. The combined effects of the key design parameters (i.e., lance spacing, injection location and spacing, gel time, injection rate, and volume) on the barrier permeability are studied. The optimization-based design is shown to have a significantly better performance than the standard engineering design. The interpenetration of adjacent CS bulbs appears to be of critical importance in meeting the barrier specifications. The three-dimensional simulations show that the barrier performance depends heavily on the path by which the final state is achieved. The in situ field measurements of the barrier permeability are consistent with, and appear to validate, the model predictions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Brookhaven Natl Lab, Adv Technol Dept, Upton, NY 11973 USA. RP Moridis, GJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. RI Finsterle, Stefan/A-8360-2009 OI Finsterle, Stefan/0000-0002-4446-9906 NR 25 TC 11 Z9 11 U1 0 U2 2 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 OCT PY 1999 VL 35 IS 10 BP 2937 EP 2953 DI 10.1029/1999WR900184 PG 17 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 240NQ UT WOS:000082832400004 ER PT J AU Tompson, AFB Carle, SF Rosenberg, ND Maxwell, RM AF Tompson, AFB Carle, SF Rosenberg, ND Maxwell, RM TI Analysis of groundwater migration from artificial recharge in a large urban aquifer: A simulation perspective SO WATER RESOURCES RESEARCH LA English DT Article ID IMPLEMENTATION; CALIFORNIA AB The increased use of reclaimed water for artificial groundwater recharge purposes has led to concerns about future groundwater quality, particularly as it relates to the introduction of new organic and inorganic contaminants into the subsurface. Here we review the development and initial application of a detailed numerical model of groundwater flow and migration in a region encompassing a large groundwater recharge operation in Orange County, California. The model is based upon a novel representation of geologic heterogeneity, which has long been known to influence local flow and transport behavior in the subsurface. The model and complementary series of isotopic analyses provide an improved scientific basis to understand flow paths, migration rates, and residence times of recharged groundwater, as well as to identify the source composition of water produced in wells near the recharge operation. From a management perspective these issues need to be confronted in order to respond to proposed regulatory constraints that would govern the operation of recharge facilities and nearby production wells. While model calibration is greatly aided by isotopic source and residence time analyses, the model also provides unique insights on the interpretation of isotopic data themselves. Isotopic estimates of groundwater age help discriminate between several equally acceptable simulations calibrated to head data only. However, the results also suggest that groundwater reaching a well spans a wide-ranging distribution of age, demonstrating the importance of geologic heterogeneity in affecting flow paths, mixing, and residence times in the vicinity of recharge basins and wells. C1 Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div L204, Livermore, CA 94551 USA. RP Tompson, AFB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div L204, POB 808, Livermore, CA 94551 USA. RI Maxwell, Reed/D-7980-2013 OI Maxwell, Reed/0000-0002-1364-4441 NR 26 TC 42 Z9 42 U1 1 U2 19 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 OCT PY 1999 VL 35 IS 10 BP 2981 EP 2998 DI 10.1029/1999WR900175 PG 18 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 240NQ UT WOS:000082832400007 ER PT J AU Vianco, PT AF Vianco, PT TI Corrosion issues in solder joint design and service SO WELDING JOURNAL LA English DT Article C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Vianco, PT (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 USA SN 0043-2296 J9 WELD J JI Weld. J. PD OCT PY 1999 VL 78 IS 10 BP 39 EP 46 PG 8 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 240WM UT WOS:000082850100007 ER PT J AU Havstad, MA Vadasz, P AF Havstad, MA Vadasz, P TI Numerical solution of the three-dimensional fluid flow in a rotating heterogeneous porous channel SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE rotating flow; heterogeneous porous media; Coriolis acceleration; secondary circulation AB A numerical solution to the problem of the three-dimensional fluid flow in a long rotating heterogeneous porous channel is presented. A co-ordinate transformation technique is employed to obtain accurate solutions over a wide range of porous media Ekman number values and consequent boundary layer thicknesses. Comparisons with an approximate asymptotic solution (for large values of Ekman number) and with theoretical predictions on the validity of Taylor-Proudman theorem in porous media for small values of Ekman number show good qualitative agreement. An evaluation of the boundary layer thickness is presented and a power-law correlation to Ekman number is shown to well-represent the results for small values of Ekman number. The different three-dimensional fluid flow regimes are presented graphically, demonstrating the distinct variation of the flow field over the wide range of Ekman numbers used. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Univ Durban Westville, Dept Mech Engn, ZA-4000 Durban, South Africa. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Vadasz, P (reprint author), Univ Durban Westville, Dept Mech Engn, Private Bag X54001, ZA-4000 Durban, South Africa. NR 15 TC 5 Z9 5 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD SEP 30 PY 1999 VL 31 IS 2 BP 411 EP 429 PG 19 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 243KN UT WOS:000082996600001 ER PT J AU Klein, RI AF Klein, RI TI Star formation with 3-D adaptive mesh refinement: the collapse and fragmentation of molecular clouds SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article DE gravitation; hydrodynamics; ISM : clouds; stars : formation ID SMOOTHED PARTICLE HYDRODYNAMICS; INTERSTELLAR CLOUDS; CORES; SYSTEMS; ACCRETION; MECHANISM; CODES AB We describe a powerful methodology for numerical solution of 3-D self-gravitational hydrodynamics problems with unprecendented resolution. This code utilizes the technique of local adaptive mesh refinement (AMR), employing multiple grids at multiple levels of resolution. These grids are automatically and dynamically added and removed as necessary to maintain adequate resolution. This technology allows solution of problems that would be prohibitively expensive with methods using fixed resolution, and it is more versatile and efficient than competing methods of achieving variable resolution. The application of this technique to simulate the collapse and fragmentation of a molecular cloud, a key step in star formation is discussed. The simulation involves many orders of magnitude of variation in length scale as fragments form. In this paper we describe the methodology and present illustrative applications for both isothermal and nonisothermal cloud collapse. We describe the numerical Jeans condition, a new criterion for stability of self-gravitational gas dynamic problems. We find that the uniformly rotating, spherical clouds treated here first collapse to disks in the equatorial plane and then, in the presence of applied perturbations, form filamentary singularities that do not fragment while isothermal. As the collapse enters the non-isothermal phase, we show the evolutionary sequence that leads to the formation of a binary system consisting of protostellar cores surrounded by distinct protostellar disks. The scale of the disks, of order 100 AU, is consistent with observations of gaseous disks surrounding single T-Tauri stars and debris disks surrounding systems such as Beta Pictoris. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Berkeley Dept Astron, Livermore, CA 94550 USA. EM klein@radhydro.berkeley.edu NR 39 TC 60 Z9 60 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD SEP 30 PY 1999 VL 109 IS 1-2 BP 123 EP 152 DI 10.1016/S0377-0427(99)00156-9 PG 30 WC Mathematics, Applied SC Mathematics GA 245CJ UT WOS:000083088400006 ER PT J AU Mezzacappa, A Messer, OEB AF Mezzacappa, A Messer, OEB TI Neutrino transport in core collapse supernovae SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article DE radiation transport; neutrinos; supernovae; Boltzmann equation; implicit methods ID II SUPERNOVAE; INFALL EPOCH; EXPLOSIONS; EQUATION; STARS; STATE; CONVECTION; MECHANISM; MODEL; FLOWS AB Core collapse supernovae occupy a special place in the cosmic hierarchy for their role in disseminating and producing most elements in the Universe heavier than hydrogen and helium, without which life as we know it would not be possible. These catastrophic events mark the end of a massive star's life and the birth of a neutron star or a black hole, and are the most energetic explosions in the Cosmos. Core collapse supernovae result when the iron core of a massive star becomes unstable at the end of the star's evolution, collapses on itself, rebounds at ultra-high densities, and produces a shock wave that will ultimately be responsible for disrupting the star. As infalling core material passes through the shock, it is compressed and heated, and the core nuclei are dissociated (broken up) at the expense of thermal, pressure-producing energy behind the shock, thereby weakening it. Ln addition to this energy loss, energy is carried away from the shocked region by massless particles know as "neutninos". The shock stalls, and is later thought to be revived by a "neutrino heating" mechanism. At the time the shock stalls, the core consists of an inner "neutrinosphere" radiating neutrinos and "antineutrinos" of three "flavors": "electron", "muon", and "tau" neutrinos and their antineutrinos. This inner core will ultimately radiate away its thermal energy, cool, and go on to form a neutron star or a black hole. Revival of the stalled shock above the neutrinosphere is mediated by the absorption of electron neutrinos and antineutrinos emerging from the radiating proto-neutron star. This heating depends sensitively on the neutrino luminosities, spectra, and distribution of neutrino direction cosines in the region behind the shock. In turn, this depends on the neutrino transport through three regions: the "neutrino-thick", diffusion region deep within the core below the neutrinosphere, the "semitransparent" region encompassing the neutrinosphere, and the "neutrino-thin", streaming region at larger radii. Sufficient accuracy for a definitive simulation of the supernova outcome can be obtained only via a solution of the neutrino Boltzmann transport equations and their coupling to the hydrodynamics equations governing the evolution of the core material. In this article we present a numerical method to solve the neutrino Boltzmann equations coupled to the core hydrodynamics. Spherical symmetry is assumed, but our methods extend to multidimensional Boltzmann transport simulations. (With the assumption of spherical symmetry, radius is the only spatial variable, rendering the simulation, at least as far as the spatial dimensions are concerned, one-dimensional. However, as we will discuss, the Boltzmann equation is a "phase space" equation in radius and neutrino direction cosine and energy, and therefore, inherently multidimensional even when spherical symmetry is assumed.) We also present the results of comparisons of "multigroup flux-limited diffusion" (approximate) neutrino transport and Boltzmann (exact) neutrino transport in post-core bounce supernova environments, with an eye toward the quantities central to the neutrino-heating, shock-revival mechanism. Multigroup flux-limited diffusion is the most sophisticated transport approximation implemented thus far in core collapse supernova simulations, and will be described in some detail in this article. Our results demonstrate that differences significant to shock revival are obtained with the two transport schemes, supporting the claim that accurate neutrino transport is paramount in simulations of these important cosmic events. We discuss the ramifications our results have for our ongoing simulations of core collapse supernovae with exact Boltzmann neutrino transport. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RI Messer, Bronson/G-1848-2012; Mezzacappa, Anthony/B-3163-2017 OI Messer, Bronson/0000-0002-5358-5415; Mezzacappa, Anthony/0000-0001-9816-9741 NR 51 TC 43 Z9 43 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD SEP 30 PY 1999 VL 109 IS 1-2 BP 281 EP 319 DI 10.1016/S0377-0427(99)00162-4 PG 39 WC Mathematics, Applied SC Mathematics GA 245CJ UT WOS:000083088400013 ER PT J AU Hix, WR Thielemann, FK AF Hix, WR Thielemann, FK TI Computational methods for nucleosynthesis and nuclear energy generation SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Review DE nuclear astrophysics; nucleosynthesis ID INELASTIC NEUTRINO SCATTERING; S-PROCESS NUCLEOSYNTHESIS; CAPTURE CROSS-SECTIONS; WEAK-INTERACTION RATES; MASS WHITE-DWARFS; DECAY HALF-LIVES; R-PROCESS; HYDROSTATIC NUCLEOSYNTHESIS; PRIMORDIAL NUCLEOSYNTHESIS; EXPLOSIVE NUCLEOSYNTHESIS AB This review concentrates on the two principle methods used to evolve nuclear abundances within astrophysical simulations, evolution via rate equations and via equilibria. Because in general the rate equations in nucleosynthetic applications form an extraordinarily stiff system, implicit methods have proven mandatory, leading to the need to solve moderately sized matrix equations. Efforts to improve the performance of such rate equation methods are focused on efficient solution of these matrix equations, by making best use of the sparseness of these matrices. Recent work to produce hybrid schemes which use local equilibria to reduce the computational cost of the rate equations is also discussed. Such schemes offer significant improvements in the speed of reaction networks and are accurate under circumstances where calculations with complete equilibrium fail. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. EM raph@phy.ornl.gov RI Hix, William/E-7896-2011 OI Hix, William/0000-0002-9481-9126 NR 135 TC 70 Z9 70 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD SEP 30 PY 1999 VL 109 IS 1-2 BP 321 EP 351 DI 10.1016/S0377-0427(99)00163-6 PG 31 WC Mathematics, Applied SC Mathematics GA 245CJ UT WOS:000083088400014 ER PT J AU Chien, SH Lau, KC Li, WK Ng, CY AF Chien, SH Lau, KC Li, WK Ng, CY TI Energetics and structures of the carbonyl chloride radical, oxalyl chloride, and their cations SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AB-INITIO; CONFORMATIONAL-ANALYSIS; ELECTRON-DIFFRACTION; ENTROPY DIFFERENCES; ENERGY AB An ab initio study on the structures and energetics of the carbonyl chloride radical and its dimer, oxalyl chloride, along with their cations, was carried out using the Gaussian-2 (G2) and Gaussian-3 (G3) models of theory. The structural results obtained include optimized geometries of ClCO, ClCO+, the anti, syn, and gauche conformers of (ClCO)(2) and the transition structure (TS) connecting the anti and gauche conformers, and (ClCO)(2)(+). The energetic results reported include the heats of formation for ClCO, various (ClCO)(2) conformers and transition structures, ClCO+, and (ClCO)(2+), as well as the adiabatic and Vertical ionization energies of ClCO and (ClCO)(2). The G3 results obtained are in very good agreement with the available experimental data. In some cases, where the experimental data are unavailable or imprecise, the G3 results should be reliable estimates. Among the three experimental Delta H degrees(f298) values for ClCO found in the literature, the one most recently reported (-21.8 +/- 2.5 kJ mol(-1)) has the best agreement with the G3 result (-19.4 kJ mol(-1)). For oxalyl chloride, we located a gauche conformer and a TS linking the anti and gauche conformers at the MP2(Full)/6-311 +G(3df.2p) level, in qualitative agreement with the experimental findings. Also, both experimental and computational results agree that both the anti and gauche conformers lie in very flat potential minima. Based on the limited number of systems studied in this work, the G3 model yields results which are in better agreement with the experimental data than the G2 method. C1 Chinese Univ Hong Kong, Dept Chem, Shatin, NT, Hong Kong. US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Li, WK (reprint author), Chinese Univ Hong Kong, Dept Chem, Shatin, NT, Hong Kong. OI LAU, Kai Chung /0000-0003-2125-6841 NR 25 TC 15 Z9 16 U1 1 U2 5 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 SEP 30 PY 1999 VL 103 IS 39 BP 7918 EP 7922 DI 10.1021/jp992123f PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 243RW UT WOS:000083011900025 ER PT J AU Dang, LX AF Dang, LX TI Computer simulation studies of ion transport across a liquid/liquid interface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID MOLECULAR-DYNAMICS SIMULATIONS; LIQUID-LIQUID INTERFACE; POLARIZABLE WATER; CARBON-TETRACHLORIDE; CLUSTERS; CHLOROFORM; SOLVATION AB The mechanism for transporting a chloride ion or a cesium ion across a water-carbon tetrachloride liquid/liquid interface is characterized using molecular dynamicss techniques. The results obtained in these studies provided new physical insight into both the free energies and solvent structures as the ion moved across the interface. The computed free-energy profiles of ion transfer for both ions increased monotonically from water to carbon tetrachloride. No free-energy minima were observed at the liquid/liquid interface. The first hydration shells of the ions were significantly reduced as the ions moved from the aqueous phase to the nonaqueous phase. A so-called "fingering" was created by the chloride ion in the nonaqueous phase, which has a similar characteristic found in the aqueous ionic cluster studies. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dang, LX (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 26 TC 60 Z9 60 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 30 PY 1999 VL 103 IS 39 BP 8195 EP 8200 DI 10.1021/jp991824+ PG 6 WC Chemistry, Physical SC Chemistry GA 243RR UT WOS:000083011500001 ER PT J AU Rodriguez, JA Dvorak, J Jirsak, T Li, SY Hrbek, J Capitano, AT Gabelnick, AM Gland, JL AF Rodriguez, JA Dvorak, J Jirsak, T Li, SY Hrbek, J Capitano, AT Gabelnick, AM Gland, JL TI Chemistry of thiophene, pyridine, and cyclohexylamine on Ni/MoSx and Ni/S/Mo(110) surfaces: Role of nickel in hydrodesulfurization and hydrodenitrogenation processes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID TRANSITION-METAL SULFIDES; HYDROGEN-SULFIDE; MO CATALYSTS; ADSORPTION; DECOMPOSITION; HDS; CO; NI; CHEMISORPTION; SPECTROSCOPY AB Synchrotron-based high-resolution photoemission has been used to study the interaction of thiophene, pyridine, and cyclohexylamine (CHA) with pure and Ni-promoted MoSx films and S/Mo(110) surfaces. The MoSx films exhibit Mo 3d and valence spectra that are very similar to those of MoS2. On the MoSx systems, the behavior of thiophene closely resembles that seen on MoS2(0002). The molecules are weakly chemisorbed, and most of them desorb at temperatures around 200 K. A small fraction of the adsorbed thiophene is bonded to Mo sites that have S vacancies and desorbs between 250 and 300 K. A similar behavior is observed for adsorbed pyridine. In contrast, CHA displays a rich chemistry on these surfaces. Mo centers that have a limited number of S vacancies and do not do chemistry with thiophene, pyridine, or H-2 are able to cleave the C-N bond in a nonaromatic H-rich molecule like CHA. The addition of Ni enhances the chemical activity of MoSx. On the NiMoSx systems, the adsorption energies of thiophene and pyridine are 5-10 kcal/mol larger than those on pure MoSx. But no dissociation of these molecules is observed on the NiMoSx surfaces. The Ni <-> S interactions reduce the reactivity of nickel, and the presence of this metal alone is not enough to promote or facilitate the cleavage of aromatic C-S or C-N bonds. Hydrogen seems to play an important role in this aspect. Extensive decomposition of thiophene is observed after creating S vacancies in MoSx, and Ni/S/Mo(110) surfaces by reaction with atomic hydrogen (2H(gas) + S-surface --> H2Sgas + vacancy(surface)). The role of Ni in NiMoSx, catalysts for hydrodesulfurization and hydrodenitrogenation processes is discussed in light of these results. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Hrbek, Jan/I-1020-2013 NR 61 TC 10 Z9 11 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 30 PY 1999 VL 103 IS 39 BP 8310 EP 8318 DI 10.1021/jp991683b PG 9 WC Chemistry, Physical SC Chemistry GA 243RR UT WOS:000083011500018 ER PT J AU Greenfield, SR Seibert, M Wasielewski, MR AF Greenfield, SR Seibert, M Wasielewski, MR TI Time-resolved absorption changes of the pheophytin Q(x) band in isolated photosystem II reaction centers at 7 K: Energy transfer and charge separation SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID REACTION-CENTER COMPLEX; FEMTOSECOND TRANSIENT ABSORPTION; RADICAL PAIR FORMATION; RHODOBACTER-SPHAEROIDES; EXCITATION-ENERGY; ELECTRON-TRANSFER; CHLOROPHYLL-A; SUBPICOSECOND EQUILIBRATION; FLUORESCENCE KINETICS; PLANT PHOTOSYNTHESIS AB The pheophytin a Q(x) spectral region of the isolated photosystem II reaction center was investigated at 7 K using femtosecond transient absorption spectroscopy. At this temperature, uphill energy transfer, which greatly complicates the interpretation of the kinetics at or near room temperature, should be essentially shut off. Low-energy (similar to 100 nJ) pulses at 661 and 683 nm were used to excite the short-wavelength and long-wavelength sides of the composite Q(y), band, providing preferential excitation of the accessory pigment pool and P680, respectively. The data analysis uses a background subtraction technique developed earlier (Greenfield et al. J. Phys. Chem. B 1997, 101, 2251-2255) to remove the kinetic components of the data that are due to the large time-dependent changes in the background that are present in this spectral legion. The instantaneous amplitude of the bleach of the pheophytin a Q(x), band with 683 nm excitation is roughly two-thirds of its final amplitude, providing strong evidence of a multimer description of the reaction center core. The subsequent growth of the bleach shows biphasic kinetics, similar to our earlier results at 278 K. The rate constant of the faster component is (5 ps)(-1) for 683 nm excitation (a factor of almost two faster than at 278 K), and represents the intrinsic rate constant for charge separation. The bleach growth with 661 nm excitation is also biphasic; however, the faster component appears to be a composite of a (5 ps)(-1) component corresponding to charge separation following subpicosecond energy transfer to the long-wavelength pigments and a roughly (22 ps)(-1) component corresponding to charge separation limited by slow energy transfer, The combined quantum yield for these two energy transfer processes is near unity. For both excitation wavelengths, there is also a roughly ( 100 ps)(-1) component to the bleach growth. Exposure to high excitation energies (greater than or equal to 1 mu J) at 683 nm results in a substantial permanent loss of ground-state absorption at 680 nm. The transient behavior of these degraded samples is also examined and is consistent with the (5 ps)(-1) rate constant for charge separation. Our results are compared to other low-temperature transient absorption and hole burning studies, as well as to our 278 K results. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Natl Renewable Energy Lab, Basic Sci Ctr, Golden, CO 80401 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Greenfield, SR (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 50 TC 40 Z9 41 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 30 PY 1999 VL 103 IS 39 BP 8364 EP 8374 DI 10.1021/jp990962w PG 11 WC Chemistry, Physical SC Chemistry GA 243RR UT WOS:000083011500024 ER PT J AU Margevicius, RW Riedle, J Gumbsch, P AF Margevicius, RW Riedle, J Gumbsch, P TI Fracture toughness of polycrystalline tungsten under mode I and mixed mode I/II loading SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE mixed mode; fracture toughness; anisotropy; tungsten ID HOT-PRESSED SI3N4; SINGLE-CRYSTALS; SURFACE FLAWS; BEHAVIOR; STEEL; TEMPERATURE; ENERGY AB The fracture toughness of swaged polycrystalline tungsten was tested parallel and perpendicular to the swaging direction and under mixed mode I/mode II loading. The fracture mode is dominated by the microstructure and changed from all-transgranular cleavage in mode I to almost all-intergranular fracture in mode IT. The mixed mode results can be related to two common failure criteria, the maximum tensile stress criterion (Maximum sigma) and the maximum energy release rate criterion (Maximum G), but the large scatter in the data prohibits a clear distinction between the two criteria. Tests at 77 K show that the polycrystal is significantly tougher than the single crystal at this temperature. This is a consequence of the deflection of the crack into the grain boundaries and the imperfect texture (as compared to a single crystal) of the polycrystalline material. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Max Planck Inst Met Forsch, D-70174 Stuttgart, Germany. RP Margevicius, RW (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS G770, Los Alamos, NM 87545 USA. RI Gumbsch, Peter/E-5879-2012 OI Gumbsch, Peter/0000-0001-7995-228X NR 37 TC 35 Z9 36 U1 0 U2 5 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 SEP 30 PY 1999 VL 270 IS 2 BP 197 EP 209 DI 10.1016/S0921-5093(99)00252-X PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 244HV UT WOS:000083046500012 ER PT J AU Anderson, KR Groza, JR Fendorf, M Echer, CJ AF Anderson, KR Groza, JR Fendorf, M Echer, CJ TI Surface oxide debonding in field assisted powder sintering SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE field activation; sintering; HREM; clean grain boundaries AB Field activated sintering techniques (FAST) have been applied to two high-temperature powder materials: tungsten and NiAl. High and atomic resolution electron microscopy (HREM/ARM) of tungsten powder sintered via FAST showed essentially clean boundaries. Analytical transmission electron microscopy (TEM) of FAST sintered NiAl also showed boundaries free of surface oxide layer(s). However, small alumina precipitates were found at and near prior particle (grain) boundaries. The boundary cleaning and precipitation phenomena are manifestations of an applied pulsed electric field. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Groza, JR (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, 1 Shields Ave, Davis, CA 95616 USA. NR 7 TC 34 Z9 40 U1 4 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 30 PY 1999 VL 270 IS 2 BP 278 EP 282 DI 10.1016/S0921-5093(99)00197-5 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 244HV UT WOS:000083046500024 ER PT J AU Peralta, P Czapka, A Obergfell, K Llanes, L Laird, C Mitchell, TE AF Peralta, P Czapka, A Obergfell, K Llanes, L Laird, C Mitchell, TE TI Effect of texture and testing conditions on strain localization during cyclic deformation of copper polycrystals SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Letter DE copper polycrystals; stress-strain curve; fatigue tests ID GRAIN-SIZE; SUBSTRUCTURE EVOLUTION; SINGLE-CRYSTALS; BEHAVIOR; FATIGUE; NICKEL; RAMP AB Fatigue tests were performed on pure copper polycrystals with a crystallographic texture different from that produced by 'standard' thermomechanical treatments, which emphasize multi-slip < 111 >-< 100 > textures. The texture along the loading axis deviated by 10-15 degrees from these two poles for the samples used here. The experiments were initiated by ramp loading as a mechanical pretreatment and the cyclic stress-strain curve (CSSC) was established by step tests using enough cycles at each step to insure saturation. Under these conditions, a plateau was observed in the CSSC at an appropriate stress level and in a reproducible fashion. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. Univ Politecn Cataluna, ETSIIB, Dept Ciencia Mat & Ingn Met, E-08028 Barcelona, Spain. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Peralta, P (reprint author), Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. RI Llanes, Luis/H-9761-2015 OI Llanes, Luis/0000-0003-1054-1073 NR 18 TC 6 Z9 7 U1 0 U2 4 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 SEP 30 PY 1999 VL 270 IS 2 BP 349 EP 353 DI 10.1016/S0921-5093(99)00200-2 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 244HV UT WOS:000083046500033 ER PT J AU Bloom, JS Kulkarni, SR Djorgovski, SG Eichelberger, AC Cote, P Blakeslee, JP Odewahn, SC Harrison, FA Frail, DA Filippenko, AV Leonard, DC Riess, AG Spinrad, H Stern, D Bunker, R Dey, A Grossan, B Perlmutter, S Knop, RA Hook, IM Feroci, M AF Bloom, JS Kulkarni, SR Djorgovski, SG Eichelberger, AC Cote, P Blakeslee, JP Odewahn, SC Harrison, FA Frail, DA Filippenko, AV Leonard, DC Riess, AG Spinrad, H Stern, D Bunker, R Dey, A Grossan, B Perlmutter, S Knop, RA Hook, IM Feroci, M TI The unusual afterglow of the gamma-ray burst of 26 March 1998 as evidence for a supernova connection SO NATURE LA English DT Article ID 25 APRIL 1998; STANDARD STARS; EMISSION AB Cosmic gamma-ray bursts have now been firmly established as one of the most powerful phenomena in the Universe, releasing almost the rest-mass energy of a neutron star within the space of a few seconds (ref. 1). The two most popular models to explain gamma-ray bursts are the coalescence of two compact objects such as neutron stars or black holes, or the catastrophic collapse of a massive star in a very energetic supernova-like explosion(2,3). Here we show that, about three weeks after the gamma-ray burst of 26 March 1998, the transient optical source associated with the burst brightened to about 60 times the expected flux, based upon an extrapolation of the initial light curve. Moreover, the spectrum changed dramatically, with the colour becoming extremely red. We argue that the new source is an underlying supernova. If our hypothesis is true then this provides evidence linking cosmologically located gamma-ray bursts with deaths of massive stars. C1 CALTECH, Palomar Observ, Pasadena, CA 91125 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. European So Observ, D-85748 Garching, Germany. CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. RP Bloom, JS (reprint author), CALTECH, Palomar Observ, Pasadena, CA 91125 USA. RI Perlmutter, Saul/I-3505-2015; OI Perlmutter, Saul/0000-0002-4436-4661; Feroci, Marco/0000-0002-7617-3421 NR 32 TC 413 Z9 418 U1 1 U2 6 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 30 PY 1999 VL 401 IS 6752 BP 453 EP 456 DI 10.1038/46744 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 243DF UT WOS:000082981200048 ER PT J AU Beaulieu, L Kwiatkowski, K Hsi, WC Lefort, T Pienkowski, L Korteling, RG Wang, G Back, B Bracken, DS Breuer, H Cornell, E Gimeno-Nogues, F Ginger, DS Gushue, S Huang, MJ Laforest, R Lynch, WG Martin, E Morley, KB Remsberg, LP Rowland, D Ramakrishnan, E Ruangma, A Tsang, MB Viola, VE Winchester, E Xi, H Yennello, SJ AF Beaulieu, L Kwiatkowski, K Hsi, WC Lefort, T Pienkowski, L Korteling, RG Wang, G Back, B Bracken, DS Breuer, H Cornell, E Gimeno-Nogues, F Ginger, DS Gushue, S Huang, MJ Laforest, R Lynch, WG Martin, E Morley, KB Remsberg, LP Rowland, D Ramakrishnan, E Ruangma, A Tsang, MB Viola, VE Winchester, E Xi, H Yennello, SJ TI Thermal excitation of heavy nuclei with 5-15 GeV/c antiproton, proton and pion beams SO PHYSICS LETTERS B LA English DT Article ID AU-197 REACTIONS; HOT NUCLEI; COLLISIONS; MULTIFRAGMENTATION; FRAGMENTATION; MATTER; DECAY; 4-PI AB Excitation-energy distributions have been derived from measurements of 5.0-14.6 GeV/e antiproton, proton and pion reactions with (197)AU target nuclei, using the ISiS 4 pi detector array. The maximum probability for producing high excitation-energy events is found for the 8 GeV/e antiproton beam relative to other hadrons, He-3 and (p) over bar beams from LEAR. For protons and pions, the excitation-energy distributions are nearly independent of hadron type and beam momentum above about 8 GeV/c. The excitation energy enhancement for (p) over bar beams and the saturation effect are qualitatively consistent with intranuclear cascade code predictions. For all systems studied, maximum cluster sizes are observed for residues with E*/A similar to 6 MeV. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Indiana Univ, IUCF, Bloomington, IN 47405 USA. Warsaw Univ, Heavy Ion Lab, Warsaw, Poland. Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Maryland, Dept Phys, College Pk, MD 20740 USA. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Texas A&M Univ, Cyclotron Lab, College Stn, TX 77843 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Michigan State Univ, Dept Phys, E Lansing, MI 48824 USA. Michigan State Univ, NSCL, E Lansing, MI 48824 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RI Ginger, David/C-4866-2011; Lynch, William/I-1447-2013; Beaulieu, Luc/A-6803-2009; Rowland, Douglas/F-3104-2014; Yennello, Sherry/B-5803-2015 OI Ginger, David/0000-0002-9759-5447; Lynch, William/0000-0003-4503-176X; Beaulieu, Luc/0000-0003-0429-6366; Rowland, Douglas/0000-0001-8059-6905; Yennello, Sherry/0000-0003-3963-5217 NR 25 TC 38 Z9 38 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 SEP 30 PY 1999 VL 463 IS 2-4 BP 159 EP 167 DI 10.1016/S0370-2693(99)01016-3 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 246ZC UT WOS:000083195200005 ER PT J AU Hall, LJ Murayama, H AF Hall, LJ Murayama, H TI Tau appearance in atmospheric neutrino interactions SO PHYSICS LETTERS B LA English DT Article AB If the correct interpretation of the Super-Kamiokande atmospheric neutrino data is nu(mu) --> nu(T), oscillation, the contained data sample should already have more than 10 tau appearance events. We study the challenging task of detecting the tau, focussing on the decay chain tau (+/-) --> rho (+/-) --> pi (+/-) pi(0) in events with quasi-elastic tau production. The background level, which is currently quite uncertain because of a lack of relevant neutral current data, can be measured by the near detector in the K2K experiment. Our estimates of the background suggest that it may be possible to detect r appearance in Super-Kamiokande with 5-10 years of running. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Hall, LJ (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 5 TC 8 Z9 8 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 SEP 30 PY 1999 VL 463 IS 2-4 BP 241 EP 247 DI 10.1016/S0370-2693(99)00951-X PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 246ZC UT WOS:000083195200017 ER PT J AU Anthony, PL Arnold, RG Averett, T Band, HR Berisso, MC Borel, H Bosted, PE Bultmann, SL Buenerd, M Chupp, T Churchwell, S Court, GR Crabb, D Day, D Decowski, P DePietro, P Erbacher, R Erickson, R Feltham, A Fonvieille, H Frlez, E Gearhart, R Ghazikhanian, V Gomez, J Griffioen, KA Harris, C Houlden, MA Hughes, EW Hyde-Wright, CE Igo, G Incerti, S Jensen, J Johnson, JR King, PM Kolomensky, YG Kuhn, SE Lindgren, R Lombard-Nelsen, RM Marroncle, J McCarthy, J McKee, P Meyer, W Mitchell, G Mitchell, J Olson, M Penttila, S Peterson, G Petratos, GG Pitthan, R Pocanic, D Prepost, R Prescott, C Qin, LM Raue, BA Reyna, D Rochester, LS Rock, S Rondon-Aramayo, OA Sabatie, F Sick, I Smith, T Sorrell, L Staley, F St Lorant, S Stuart, LM Szalata, Z Terrien, Y Tobias, A Todor, L Toole, T Trentalange, S Walz, D Welsh, RC Wesselmann, FR Wright, TR Young, CC Zeier, M Zhu, H Zihlmann, B AF Anthony, PL Arnold, RG Averett, T Band, HR Berisso, MC Borel, H Bosted, PE Bultmann, SL Buenerd, M Chupp, T Churchwell, S Court, GR Crabb, D Day, D Decowski, P DePietro, P Erbacher, R Erickson, R Feltham, A Fonvieille, H Frlez, E Gearhart, R Ghazikhanian, V Gomez, J Griffioen, KA Harris, C Houlden, MA Hughes, EW Hyde-Wright, CE Igo, G Incerti, S Jensen, J Johnson, JR King, PM Kolomensky, YG Kuhn, SE Lindgren, R Lombard-Nelsen, RM Marroncle, J McCarthy, J McKee, P Meyer, W Mitchell, G Mitchell, J Olson, M Penttila, S Peterson, G Petratos, GG Pitthan, R Pocanic, D Prepost, R Prescott, C Qin, LM Raue, BA Reyna, D Rochester, LS Rock, S Rondon-Aramayo, OA Sabatie, F Sick, I Smith, T Sorrell, L Staley, F St Lorant, S Stuart, LM Szalata, Z Terrien, Y Tobias, A Todor, L Toole, T Trentalange, S Walz, D Welsh, RC Wesselmann, FR Wright, TR Young, CC Zeier, M Zhu, H Zihlmann, B TI Measurement of the deuteron spin structure function g(1)(d)(x) for 1 (GeV/c)(2) < Q(2) < 40 (GeV/c)(2) SO PHYSICS LETTERS B LA English DT Article ID DEEP-INELASTIC-SCATTERING; STRUCTURE-FUNCTION G(1)(N); POLARIZED PROTONS; ASYMMETRIES; ELECTRONS; LEPTONS; TARGET; HE-3; QCD AB New measurements are reported on the deuteron spin structure function g(1)(d), These results were obtained from deep inelastic scattering of 48.3 GeV electrons on polarized deuterons in the kinematic range 0.01 < x < 0.9 and 1 < Q(2) < 40 (GeV/c)(2). These are the first high dose electron scattering data obtained using lithium deuteride ((LiH)-Li-6-H-2) as the target material. Extrapolations of the data were performed to obtain moments of Delta Sigma. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Stanford, CA 94305 USA. American Univ, Washington, DC 20016 USA. Univ Basel, Inst Phys, CH-4056 Basel, Switzerland. Univ Blaise Pascal, LPC IN2P3 CNRS, F-63170 Aubiere, France. Ruhr Univ Bochum, D-4630 Bochum, Germany. CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. CEA Saclay, DAPNIA, Serv Phys Nucl, F-91191 Gif Sur Yvette, France. Florida Int Univ, Miami, FL 33199 USA. Kent State Univ, Kent, OH 44242 USA. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Smith Coll, Northampton, MA 01063 USA. RP Anthony, PL (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Averett, Todd/A-2969-2011; Rondon Aramayo, Oscar/B-5880-2013; Frlez, Emil/B-6487-2013; Kolomensky, Yury/I-3510-2015; Sabatie, Franck/K-9066-2015; OI Kolomensky, Yury/0000-0001-8496-9975; Sabatie, Franck/0000-0001-7031-3975; Wesselmann, Frank/0000-0001-7834-7977; Hyde, Charles/0000-0001-7282-8120; King, Paul/0000-0002-3448-2306; Incerti, Sebastien/0000-0002-0619-2053 NR 30 TC 182 Z9 183 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 30 PY 1999 VL 463 IS 2-4 BP 339 EP 345 DI 10.1016/S0370-2693(99)00940-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 246ZC UT WOS:000083195200032 ER PT J AU Schlosser, P Bayer, R Bonisch, G Cooper, LW Ekwurzel, B Jenkins, WJ Khatiwala, S Pfirman, S Smethie, WM AF Schlosser, P Bayer, R Bonisch, G Cooper, LW Ekwurzel, B Jenkins, WJ Khatiwala, S Pfirman, S Smethie, WM TI Pathways and mean residence times of dissolved pollutants in the ocean derived from transient tracers and stable isotopes SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution (IAEAs) CY OCT 05-09, 1998 CL MONACO, MONACO SP Intergovt Oceanographic Comm,UNESCO, United Nations Environm Program, Int Maritime Org, Comm Int Explorat Sci Mer Mediterranee DE pathways; residence times; pollutants; oceanic waters; tracers ID DEEP-WATER FORMATION; GREENLAND NORWEGIAN SEAS; SOUTHERN CANADIAN BASIN; ARCTIC-OCEAN; NORTH-ATLANTIC; NANSEN BASIN; FRESH-WATER; WEDDELL SEA; RATES; TRITIUM AB During the past decades, a variety of transient tracers have been used to derive information on pathways and mean residence times of oceanic water masses. Here, we discuss how information obtained in such studies can be applied to studying the spreading of dissolved pollutants in the ocean. The discussion focuses on the transient tracers tritium/He-3 and the (H2O)-O-18/(H2O)-O-16 ratio of water. These tracers are used in combination with CFCs and C-14 in a case study of Arctic Ocean contaminant transport to: (1) separate the freshwater components contained in the near-surface waters; (2) infer mean pathways of freshwater and associated contaminants from the (H2O)-O-18/(H2O)-O-16 distribution in the surface waters; and (3) determine mean residence times of the surface, intermediate, deep and bottom waters. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Columbia Univ, Dept Earth & Environm Sci, New York, NY USA. Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Columbia Univ Barnard Coll, Dept Environm Sci, New York, NY 10027 USA. RP Schlosser, P (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RI Schlosser, Peter/C-6416-2012; Cooper, Lee/E-5251-2012 OI Schlosser, Peter/0000-0002-6514-4203; Cooper, Lee/0000-0001-7734-8388 NR 52 TC 3 Z9 3 U1 0 U2 4 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 SEP 30 PY 1999 VL 238 SI SI BP 15 EP 30 PG 16 WC Environmental Sciences SC Environmental Sciences & Ecology GA 248JW UT WOS:000083272200003 ER PT J AU Sjoblom, KL Salo, A Bewers, JM Cooper, J Dyer, RS Lynn, NM Mount, ME Povinec, PP Sazykina, TG Schwarz, J Scott, EM Sivintsev, YV Tanner, JE Warden, JM Woodhead, D AF Sjoblom, KL Salo, A Bewers, JM Cooper, J Dyer, RS Lynn, NM Mount, ME Povinec, PP Sazykina, TG Schwarz, J Scott, EM Sivintsev, YV Tanner, JE Warden, JM Woodhead, D TI International Arctic Seas Assessment Project SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution (IAEAs) CY OCT 05-09, 1998 CL MONACO, MONACO SP Intergovt Oceanographic Comm,UNESCO, United Nations Environm Program, Int Maritime Org, Comm Int Explorat Sci Mer Mediterranee DE Arctic seas; radioactive waste; radiation dose; remedial actions AB The International Atomic Energy Agency responded to the news that the former Soviet Union had dumped radioactive wastes in the shallow waters of the Arctic Seas, by launching the International Arctic Seas Assessment Project in 1993. The project had two objectives: to assess the risks to human health and to the environment associated with the radioactive wastes dumped in the Kara and Parents Seas; and to examine possible remedial actions related to the dumped wastes and to advise on whether they are necessary and justified. The current radiological situation in the Arctic waters was examined to assess whether there is any evidence for releases from the dumped waste. Potential future releases from the dumped wastes were predicted, concentrating on the high-level waste objects containing the major part of the radionuclide inventory of the wastes. Environmental transport of released radionuclides was modelled and the associated radiological impact on humans and the biota was assessed. The feasibility, costs and benefits of possible remedial measures applied to a selected high-level waste object were examined. Releases from identified dumped objects were found to be small and localised to the immediate vicinity of the dumping sites. Projected future annual doses to members of the public in typical local population groups were very small, less than 1 mSv - corresponding to a trivial risk. Projected future doses to a hypothetical group of military personnel patrolling the foreshore of the fjords in which wastes have been dumped were higher, up to 4 mSv/year, which still is of the same order as the average annual natural background dose. Moreover, since any of the proposed remedial actions were estimated to cost several million US$ to implement, remediation was not considered justified on the basis of potentially removing a collective dose of 10 man Sv. Doses calculated to marine fauna were insignificant, orders of magnitude below these at which detrimental effects on fauna populations might be expected to occur. Remediation was thus concluded not to be warranted on radiological grounds. (C) 1999 Elsevier Science B.V. All rights reserved. C1 IAEA, Marine Radiol Div, A-1400 Vienna, Austria. IAEA, Helsinki, Finland. Bedford Inst Oceanog, Dartmouth, NS, Canada. Natl Radiol Protect Board, Didcot OX11 0RQ, Oxon, England. US EPA, Washington, DC 20460 USA. Royal Naval Coll, London, England. Lawrence Livermore Natl Lab, Livermore, CA USA. Marine Environm Lab, IAEA, Monaco, Monaco. SPA Typhoon, Obninsk, Russia. Hamburg Schiffsbau & Versuchsanstalt GMBH, Hamburg, Germany. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. IV Kurchatov Atom Energy Inst, RRC, Moscow 123182, Russia. Pacific NW Lab, Richland, WA 99352 USA. Ctr Environm Fisheries & Agr Sci, Lowestoft, Suffolk, England. RP Sjoblom, KL (reprint author), IAEA, Marine Radiol Div, POB 100, A-1400 Vienna, Austria. OI Povinec, Pavel/0000-0003-0275-794X NR 18 TC 2 Z9 2 U1 0 U2 0 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 SEP 30 PY 1999 VL 238 SI SI BP 153 EP 166 PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA 248JW UT WOS:000083272200014 ER PT J AU Povinec, PP Woodhead, D Blowers, P Bonfield, R Cooper, M Chen, QJ Dahlgaard, H Dovlete, C Fox, V Froehlich, K Gastaud, J Groning, M Hamilton, T Ikeuchi, Y Kanisch, G Kruger, A Kwong, LLW Matthews, M Morgenstern, U Mulsow, S Pettersson, H Smedley, P Taylor, B Taylor, C Tinker, R AF Povinec, PP Woodhead, D Blowers, P Bonfield, R Cooper, M Chen, QJ Dahlgaard, H Dovlete, C Fox, V Froehlich, K Gastaud, J Groning, M Hamilton, T Ikeuchi, Y Kanisch, G Kruger, A Kwong, LLW Matthews, M Morgenstern, U Mulsow, S Pettersson, H Smedley, P Taylor, B Taylor, C Tinker, R TI Marine radioactivity assessment of Mururoa and Fangataufa atolls SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution (IAEAs) CY OCT 05-09, 1998 CL MONACO, MONACO SP Intergovt Oceanographic Comm,UNESCO, United Nations Environm Program, Int Maritime Org, Comm Int Explorat Sci Mer Mediterranee DE marine radioactivity; radionuclides; atoll; nuclear sites; nuclear weapons AB The International Atomic Energy Agency (IAEA) carried out an international project 'The Study of the Radiological Situation at the Atolls of Mururoa and Fangataufa' with the aim of assessing the present and future radiological situation at the atolls and making recommendations for either monitoring or remedial actions if they are deemed necessary. The paper concentrates on marine radioactivity aspects and gives an estimation of present radionuclide concentrations in water, sediment and biota of the Mururoa and Fangataufa lagoons and the surrounding ocean. The dominant radionuclide in both lagoons is Pu in sediments (the total inventory is approximately 30 TBq). A decline in radionuclide concentrations has been observed in recent years in lagoon water, with the exception of H-3 and Sr-90, for which a contribution from underground sources is to be expected. Radionuclide concentrations in biota from the lagoons and the surrounding ocean are low and consistent with previous measurements. The observed radionuclide concentrations in both lagoons imply that no radiological risk exists for hypothetical inhabitants of Mururoa and Fangataufa Atolls. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved. C1 Int Atom Energy Agcy, Marine Environm Lab, MC-98000 Monaco, Monaco. Lowestoft Lab, CEFAS, Lowestoft NR33 0HT, Suffolk, England. Australian Radiat Labs, Yallambie, Vic 3085, Australia. Riso Natl Lab, Dept Hlth Phys, DK-4000 Roskilde, Denmark. Int Atom Energy Agcy, Isotope Hydrol Sect, A-1400 Vienna, Austria. Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div, Livermore, CA 94551 USA. Inst Fisheries Ecol, Fed Fisheries Res Ctr, D-22589 Hamburg, Germany. Natl Radiat Lab, Christchurch, New Zealand. Inst Geol & Nucl Sci, Lower Hutt, New Zealand. RP Povinec, PP (reprint author), Int Atom Energy Agcy, Marine Environm Lab, 4 Quai Antoine 1er, MC-98000 Monaco, Monaco. RI DOVLETE, CONSTANTIN/F-2892-2011; OI DOVLETE, CONSTANTIN/0000-0002-3951-9534; Povinec, Pavel/0000-0003-0275-794X NR 7 TC 2 Z9 2 U1 0 U2 2 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 SEP 30 PY 1999 VL 238 SI SI BP 249 EP 267 PG 19 WC Environmental Sciences SC Environmental Sciences & Ecology GA 248JW UT WOS:000083272200022 ER PT J AU Robison, WL Noshkin, VE AF Robison, WL Noshkin, VE TI Radionuclide characterization and associated dose from long-lived radionuclides in close-in fallout delivered to the marine environment at Bikini and Enewetak Atolls SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution (IAEAs) CY OCT 05-09, 1998 CL MONACO, MONACO SP Intergovt Oceanographic Comm,UNESCO, United Nations Environm Program, Int Maritime Org, Comm Int Explorat Sci Mer Mediterranee DE Marshall Islands; radioactivity; dose assessment; marine environment ID LAGOON AB Between June 1946 and October 1958, Enewetak and Bikini Atolls were used by the US as testing grounds for 66 nuclear devices. The combined explosive yield from these tests was 107 million t (million t TNT equivalents). This testing produced close-in fallout debris that was contaminated with quantities of radioactive fission and particle activated products, and unspent radioactive nuclear fuel that entered the aquatic environment of the atolls. Today, the sediments in the lagoons are reservoirs for tens of TBq of the transuranics and some long-lived fission and activation products. The larger amounts of contamination are associated with fine and coarse sediment material adjacent to the locations of the high yield explosions. Radionuclides are also distributed vertically in the sediment column to various depths in all regions of the lagoons. Concentrations greater than fallout background levels are found in filtered water sampled over several decades from all locations and depths in the lagoons. This is a direct indication that the radionuclides are continuously mobilized to solution from the solid phases. Of particular importance is the fact that the long-lived radionuclides are accumulated to different levels by indigenous aquatic plants and organisms that are used as food by resident people. One might anticipate finding continuous high contamination levels in many of the edible marine organisms from the lagoons, since the radionuclides associated with the sediments are not contained and are available to the different organisms in a relatively shallow water environment. This is not the case. We estimate that the radiological dose from consumption of the edible parts of marine foods at Enewetak and Bikini is presently approximately 0.05% of the total 50-year integral effective dose from all other exposure pathways that include ingestion of terrestrial foods and drinking water, external exposure and inhalation. The total radiological dose from the marine pathway is dominated by the natural radionuclides, (210)po and (210)pb. Man-made radionuclides presently contribute < 0.3% of the dose from these natural radionuclides in the marine food chain and within approximately 90 years only 0.15%. Published by Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Noshkin, VE (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 38 TC 3 Z9 3 U1 2 U2 4 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 SEP 30 PY 1999 VL 238 SI SI BP 311 EP 327 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA 248JW UT WOS:000083272200027 ER PT J AU Bloom, NS Lasorsa, BK AF Bloom, NS Lasorsa, BK TI Changes in mercury speciation and the release of methyl mercury as a result of marine sediment dredging activities SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution (IAEAs) CY OCT 05-09, 1998 CL MONACO, MONACO SP Intergovt Oceanographic Comm,UNESCO, United Nations Environm Program, Int Maritime Org, Comm Int Explorat Sci Mer Mediterranee DE marine dredging; mercury; methyl mercury; sediment; porewater ID AQUEOUS-PHASE ETHYLATION; ENVIRONMENTAL-SAMPLES; DISTILLATION; WATER AB During the dredging of a moderately contaminated marine waterway (Lavaca Bay, Texas, USA), high concentrations of total mercury (THg, 75-1533 ng/l) and methyl mercury (MHg, 5-70 ng/l) were observed in the decant water from an upland dredge spoils settling basin. By comparison, the water column of the bay contains 7-200 ng/l THg and 0.05-0.8 ng/l MHg. The Hg concentrations observed in the decant water were higher than could be accounted for by the release of sediment pore water, which contained elevated MHg (2-200 ng/l) in the surface 3 cm of the sediments, but diminished exponentially with depth. Laboratory mixing experiments showed that approximately 5% of the sediment bound MHg, and less than 1% of the total mercury was released upon shaking with seawater. Although significant MHg releases could occur from the upper 0-5 cm of the sediments, when integrated over the entire dredged volume, this source is insufficient to account for the levels found in the settling basin decant water. The settling basin became very biologically active, containing algal blooms and releasing hydrogen sulfide to the air, suggesting that increased methylation in the disturbed sediment was responsible for the releases. A laboratory mesocosm study was performed to simulate the findings in the settling pond, but no obvious increase in biological activity occurred, and MHg concentrations increased only to 0.6 ng/l. The implications of these observations may be significant for the local region approximately a dredging site, although crude mass balance considerations show that the MHg flux from this source is trivial compared to bay-wide processes. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved. C1 Frontier Geosci Inc, Seattle, WA 98109 USA. Battelle NW Marine Sci Lab, Sequim, WA 98382 USA. RP Bloom, NS (reprint author), Frontier Geosci Inc, 414 Pontius N, Seattle, WA 98109 USA. NR 13 TC 20 Z9 20 U1 0 U2 6 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 SEP 30 PY 1999 VL 238 SI SI BP 379 EP 385 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA 248JW UT WOS:000083272200032 ER PT J AU Kelley, JM Bond, LA Beasley, TM AF Kelley, JM Bond, LA Beasley, TM TI Global distribution of Pu isotopes and Np-237 SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT International Symposium on Marine Pollution (IAEAs) CY OCT 05-09, 1998 CL MONACO, MONACO SP Intergovt Oceanographic Comm,UNESCO, United Nations Environm Program, Int Maritime Org, Comm Int Explorat Sci Mer Mediterranee DE plutonium isotopes; Np-237; distribution of radionuclides ID FALLOUT AB Inventories and compositions of Pu isotopes and Np-237 in archived soil samples collected in the 1970s from 54 locations around the world were determined to provide regional baselines for recognizing possible future environmental inputs of non-fallout Pu and Np. As sample sizes used in this work were small (typically 1 g), inhomogeneities in Pu and Np concentrations were easily recognizable and, as a result, we were able to determine that atypical debris in South America, from French testing in the South Pacific, is more widely and uniformly distributed than previously supposed. From our results we conclude that fallout Np-237/ (239)pU atom ratios are generally lower in the Southern Hemisphere (similar to 0.35) than in the Northern Hemisphere (similar to 0.47.) Moreover, Np-237/(PU)-P-239 atom ratios are more device-dependent, hence more variable, than counterpart Pu-240/ Pu-239 atom ratios. Given predictable trends caused by sample inhomogeneities, with only two exceptions, the Pu results of this work are entirely consistent with (and in several instances improve on) results previously reported for these same samples. However, unlike earlier interpretations used to explain these results, we recommend that fallout isotopic signatures be represented by mixing lines, rather than averages, to better reflect regional variations of stratospheric fallout inventories relative to tropospheric fallout inventories, and provide the theoretical basis for doing so. Finally, the Np results of this work constitute one of the largest single compilations of such data reported to date. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kelley, JM (reprint author), Pacific NW Natl Lab, Battelle Blvd,MS P7-07, Richland, WA 99352 USA. NR 16 TC 111 Z9 111 U1 0 U2 8 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 SEP 30 PY 1999 VL 238 SI SI BP 483 EP 500 PG 18 WC Environmental Sciences SC Environmental Sciences & Ecology GA 248JW UT WOS:000083272200041 ER PT J AU Vaidyanathan, R Bourke, MAM Dunand, DC AF Vaidyanathan, R Bourke, MAM Dunand, DC TI Phase fraction, texture and strain evolution in superelastic NiTi and NiTi-TiC composites investigated by neutron diffraction SO ACTA MATERIALIA LA English DT Article DE composites; neutron scattering; phase transformations; shape memory; superelasticity ID SHAPE-MEMORY RECOVERY; MARTENSITIC-TRANSFORMATION; MECHANICAL-PROPERTIES; RIETVELD REFINEMENT; BEHAVIOR; DEFORMATION; MATRIX; ALLOYS AB Samples of superelastic NiTi and superelastic NiTi reinforced with 10 vol.% TiC particles were deformed under uniaxial compression to 975 MPa while neutron diffraction spectra were simultaneously collected. Despite the presence of stiff TiC particles, a macroscopic strain of 3% was obtained in the composite on loading and was fully recovered on unloading. The diffraction spectra were analyzed by Rietveld refinement that included a spherical harmonic description of the texture and a lattice plane (hkl) dependent formulation of the elastic strain. The experiments provided bulk, phase-specific measurements of the evolution of phase fractions, texture and strains during the reversible stress-induced austenite to martensite transformation responsible for the large recoverable strains. For the composite, Eshelby elastic theory is used to predict the discrete phase strains measured by neutron diffraction. The observed behavior suggests that the martensite accommodates the mismatch with the transforming austenite (while they co-exist) and the TIC particles (in the case of the composite). (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Los Alamos Natl Lab, MST, LANSCE, Los Alamos, NM 87545 USA. RP Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RI Dunand, David/B-7515-2009; OI Dunand, David/0000-0001-5476-7379 NR 48 TC 71 Z9 72 U1 3 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD SEP 29 PY 1999 VL 47 IS 12 BP 3353 EP 3366 DI 10.1016/S1359-6454(99)00214-1 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 245CF UT WOS:000083088100004 ER PT J AU Clot, E Eckert, J AF Clot, E Eckert, J TI From inelastic neutron scattering to structural information. A two-dimensional parametrized model to study metal-(H-2) interaction SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; MOLECULAR-HYDROGEN COMPLEXES; EXTREMELY LOW BARRIER; DIHYDROGEN COMPLEXES; TRIATOMIC-MOLECULES; METAL-COMPLEXES; H-2 BINDING; SOLID-STATE; X-RAY; DIFFRACTION AB A two-dimensional dynamical parametrized model is derived to study the M-(H-2) interaction in transition-metal molecular hydrogen complexes. The parameters have been adjusted to reproduce the observed inelastic neutron scattering transitions through a least-squares fit procedure. The vibrational levels are obtained by solving the nuclear Schrodinger equation in a discrete variable representation. From this procedure, structural information such as the barrier to rotation of the Hz ligand and the H-H distance have been obtained. The accuracy of the model is tested on four systems with M-(H2) interactions of different nature. The resulting H-H bond distances are in very good agreement with neutron diffraction structures where available. C1 Univ Montpellier 2, LSDSMS, UMR 5636, CC 014, F-34095 Montpellier 05, France. Univ Calif Los Alamos Natl Lab, LANSCE MS H805, Los Alamos, NM 87545 USA. RP Clot, E (reprint author), Univ Montpellier 2, LSDSMS, UMR 5636, CC 014, F-34095 Montpellier 05, France. RI Clot, Eric/P-9585-2015 OI Clot, Eric/0000-0001-8332-5545 NR 45 TC 15 Z9 15 U1 0 U2 3 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 SEP 29 PY 1999 VL 121 IS 38 BP 8855 EP 8863 DI 10.1021/ja9836141 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 244BT UT WOS:000083032500021 ER PT J AU Schaaff, TG Stephenson, JL McLuckey, SA AF Schaaff, TG Stephenson, JL McLuckey, SA TI The reactivity of gaseous ions of bradykinin and its analogues with hydro- and deuteroiodic acid SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID TANDEM MASS-SPECTROMETRY; SURFACE-INDUCED DISSOCIATION; GAS-PHASE BASICITIES; INFRARED RADIATIVE DISSOCIATION; CHARGE-SEPARATION REACTIONS; PROTON-TRANSFER REACTIVITY; CYTOCHROME-C IONS; ELECTROSPRAY-IONIZATION; HIGH-RESOLUTION; DIELECTRIC POLARIZABILITY AB The kinetics of attachment of hydroiodic acid to gaseous protonated bradykinin, des-Arg(1)-bradykinin, des-Arg(9)-bradykinin, and their respective methyl esters are reported. Rate constants range from 9.3 x 10(-11) cm(3)-s(-1) for attachment of hydroiodic acid to the (M + H)(+) ion of bradykinin to much less than 3 x 10(-12) cm(3)-s(-1) for a slow-reacting component of a population of (M + H)(+) ions derived from des-Arg(9)-bradykinin. In the cases of the (M + 2H)(2+) ions from bradyErinin and the (M + H)(+) ions from des-Arg(9)-bradykinin, the rate data could not be fit with a single rate constant, indicating the presence of at least two non-interconverting ion populations. For the (M + 2H)(2+) ions, it was demonstrated that the two reacting structures could be induced to interconvert upon gentle activation. The attachment sites are the most basic neutral sites of the molecule, viz., arginine and the N-terminus in the case of bradykinin and its analogues. A simple picture is proposed to estimate the rate constant for hydroiodic acid attachment to a fully exposed neutral basic site. The picture is based upon the assumption that a significant degree of proton transfer from hydroiodic acid to the attachment site occurs and therefore estimates that the capture radius is the distance at which the endoergicity of the proton-transfer reaction is just compensated for by the Coulomb attraction of the ion pair. Storage of the ions in the presence of deuterioiodic acid (DI) showed evidence for hydrogen/deuterium exchange. Two competing mechanisms can lead to H/D exchange, one of which involves initial DI attachment to a neutral basic site. However, experimental evidence suggests that the gas phase H/D exchange reactions result primarily from a "relay-type" mechanism proposed for similar systems reacting with D2O. These results provide important new information to facilitate the use of hydroiodic acid attachment kinetics and H/D exchange kinetics using DI as chemical probes of three-dimensional gaseous polypeptide ion structure. C1 Oak Ridge Natl Lab, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. RP McLuckey, SA (reprint author), Oak Ridge Natl Lab, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 100 TC 41 Z9 41 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 SEP 29 PY 1999 VL 121 IS 38 BP 8907 EP 8919 DI 10.1021/ja991553g PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 244BT UT WOS:000083032500027 ER PT J AU Feng, BB Wunschel, DS Masselon, CD Pasa-Tolic, L Smith, RD AF Feng, BB Wunschel, DS Masselon, CD Pasa-Tolic, L Smith, RD TI Retrieval of DNA using soft-landing after mass analysis by ESI-FTICR for enzymatic manipulation SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ASSEMBLED MONOLAYER SURFACES; SICKLE-CELL-ANEMIA; POLYATOMIC IONS; NUCLEIC-ACIDS; SPECTROMETRY; PCR; OLIGONUCLEOTIDE; AMPLIFICATION; EXCITATION; MOLECULE C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Wunschel, David/F-3820-2010; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 29 TC 32 Z9 32 U1 0 U2 3 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 SEP 29 PY 1999 VL 121 IS 38 BP 8961 EP 8962 DI 10.1021/ja9923888 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 244BT UT WOS:000083032500040 ER PT J AU Gokce, OH Amin, S Ravindra, NM Szostak, DJ Paff, RJ Fleming, JG Galewski, CJ Shallenberger, J Eby, R AF Gokce, OH Amin, S Ravindra, NM Szostak, DJ Paff, RJ Fleming, JG Galewski, CJ Shallenberger, J Eby, R TI Effects of annealing on X-ray-amorphous CVD W-Si-N barrier layer materials SO THIN SOLID FILMS LA English DT Article DE crystallization; metallization; nitrides; tungsten ID W)-SI-N DIFFUSION-BARRIERS; CHEMICAL-VAPOR-DEPOSITION; NITRIDE SCHOTTKY CONTACTS; TUNGSTEN NITRIDE; GAAS; METALLIZATIONS; AL; TA; STABILITY; SILICON AB The influence of furnace and rapid thermal annealing (RTA) on X-ray-amorphous, chemically vapor deposited (CVD) W-Si-N barrier layers on SiO2/Si structures have been investigated. Enhanced amount of nitrogen loss from the barrier films with increased annealing temperatures has been observed. Spectral emissometry has been employed as a novel tool to study the changes in the optical properties of the W-Si-N films in the infrared region. Annealing the structures at 800 degrees C has resulted in a significant increase in surface reflectance along with a decrease in transmittance, while that at 450 degrees C has resulted in a relatively small decrease in both reflectance and transmittance. All of the annealing conditions have led to reduced film resistivity. It is postulated that nitrogen occupies two different interstitial sites in the micro/nanocrystallites of as-deposited W-Si-N structure and leaves these sites upon annealing at high temperatures. Majority of the N atoms or molecules in the annealed W-Si-N films are assigned to the grain boundaries. (C) 1999 Elsevier Science S.A. All rights reserved. C1 New Jersey Inst Technol, Newark, NJ 07102 USA. Sarnoff Corp, Princeton, NJ USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Evans E Inc, Plainsboro, NJ 08536 USA. Focal Point Instruments, Glen Gardner, NJ USA. RP Gokce, OH (reprint author), Stevens Inst Technol, Dept Chem Biochem & Mat Engn, Hoboken, NJ 07030 USA. NR 42 TC 14 Z9 16 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 29 PY 1999 VL 353 IS 1-2 BP 149 EP 156 DI 10.1016/S0040-6090(99)00424-1 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 243ND UT WOS:000083003400026 ER PT J AU Mammana, VP Silva, S Mansano, RD Verdonck, P Pavani, A Salvadori, MC Brown, IG AF Mammana, VP Silva, S Mansano, RD Verdonck, P Pavani, A Salvadori, MC Brown, IG TI Porous freestanding diamond membranes with reduced pore diameter SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 25th International Conference on Metallurgical Coatings and Thin Films CY APR 25-MAY 01, 1998 CL SAN DIEGO, CALIFORNIA SP Vacuum Met, Thin Film Div, AVS DE diamond; chemical vapor deposition (CVD); plasma processing and deposition; surface morphology ID CHEMICAL-VAPOR-DEPOSITION; X-RAY-LITHOGRAPHY; POROSITY; MASK AB We have shown previously that porous diamond membranes can be fabricated using a method based on growing diamond on a patterned silicon substrate. The technique used to pattern the silicon is conventional lithography. In this work we present a method for reducing the pore size using diamond post-deposition over the membrane. An important concern in this work was to determine the pore-shutting rate, considering the time post-deposition and the pore morphology. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Sao Paulo, BR-05315970 Sao Paulo, Brazil. Ctr Tecnol Informat, Inst Microelect, Campinas, SP, Brazil. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Salvadori, MC (reprint author), Univ Sao Paulo, CP 66318, BR-05315970 Sao Paulo, Brazil. RI Mansano, Ronaldo/A-3888-2008; Salvadori, Maria Cecilia/A-9379-2013; OI Mansano, Ronaldo/0000-0002-9567-1813; Silva, S. Ravi P./0000-0002-0356-1319 NR 11 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 29 PY 1999 VL 353 IS 1-2 BP 239 EP 243 DI 10.1016/S0040-6090(99)00296-5 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 243ND UT WOS:000083003400040 ER PT J AU Vitanov, NV Suominen, KA Shore, BW AF Vitanov, NV Suominen, KA Shore, BW TI Creation of coherent atomic superpositions by fractional stimulated Raman adiabatic passage SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; DELAYED LASER-PULSES; POPULATION TRANSFER; MOMENTUM-TRANSFER; 3-LEVEL; SYSTEMS; AMPLIFICATION; TRANSITIONS; GENERATION; STATES AB We discuss the properties of a simple and robust scheme for preparing atoms and molecules in an arbitrary preselected coherent superposition of quantum states-fractional stimulated Raman adiabatic passage (fractional STIRAP)-first proposed by Marte el al (1991 Phys. Rev. A 44 R4118). As in STIRAP, the Stokes pulse arrives before the pump purse, but unlike STIRAP, here the two pulses terminate simultaneously, while maintaining a constant ratio of amplitudes. We extend earlier research and suggest a realization of this scheme with two smoothly varying delayed laser pulses (which can be derived from a single laser), the parameters of the created superposition being controlled by the polarization of the delayed pulse. Furthermore, we provide simple analytic estimates of the robustness of this process against Variations in the laser intensity, laser frequency and pulse delay. Finally, we discuss an extension to multistate systems which provides a possibility for creating coherent superpositions of more than two states. C1 Helsinki Inst Phys, FIN-00014 Helsinki, Finland. Univ Kaiserslautern, Dept Phys, D-67653 Kaiserslautern, Germany. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Helsinki Inst Phys, PL 9, FIN-00014 Helsinki, Finland. RI Suominen, Kalle-Antti/H-9076-2012; Vitanov, Nikolay/A-1248-2013; OI Suominen, Kalle-Antti/0000-0002-1091-2893; Vitanov, Nikolay/0000-0002-8599-4766 NR 42 TC 148 Z9 152 U1 1 U2 20 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 28 PY 1999 VL 32 IS 18 BP 4535 EP 4546 DI 10.1088/0953-4075/32/18/312 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 241BH UT WOS:000082861800014 ER PT J AU Tannian, BE Stokely, CL Dunning, FB Reinhold, CO Burgdorfer, J AF Tannian, BE Stokely, CL Dunning, FB Reinhold, CO Burgdorfer, J TI Manipulation of atomic l-state distributions using pulsed electric fields SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID HALF-CYCLE PULSES; RYDBERG STATES AB A technique to manipulate the l-state distribution of high-n high-n Rydberg atoms is described that is based on the application of a large-amplitude rectangular electric field pulse whose rise and fall times are short compared to the classical electron orbital period and whose duration is comparable to the Stark period in the field. It is shown that by varying the duration (and/or amplitude) of this pulse, the final l-state distribution can be controlled and that this distribution can be calculated reliably using classical trajectory Monte Carlo techniques. C1 Rice Univ, Dept Phys, Houston, TX 77005 USA. Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Vienna Univ Technol, Inst Theoret Phys, A-1040 Vienna, Austria. RP Burgdorfer, J (reprint author), Rice Univ, Dept Phys, 6100 Main St, Houston, TX 77005 USA. NR 13 TC 9 Z9 9 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 28 PY 1999 VL 32 IS 18 BP L517 EP L524 DI 10.1088/0953-4075/32/18/101 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 241BH UT WOS:000082861800001 ER PT J AU Weng, XC Ding, YS Volkow, ND AF Weng, XC Ding, YS Volkow, ND TI Imaging the functioning human brain SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Editorial Material ID DOPAMINE TRANSPORTER OCCUPANCY; BABOON BRAIN; MEMORIES AB One of the most exciting methodological advances for brain research field arises in functional brain imaging, which enables us to localize and characterize neural activity and biochemical events in the living human brain. Recently developed event-related functional MRI makes it possible to visualize the brain activity associated with cognitive processes with the temporal resolution of the hemodynamic response. In addition, the high sensitivity and selectivity of positron-emission tomography allow us to probe the neurochemical processes at the molecular level. Positron-emission tomography also has been applied to investigate the effects of therapeutic drugs as well as the effects of drugs of abuse. C1 Chinese Acad Sci, Inst Psychol, Lab Higher Brain Funct, Beijing 100101, Peoples R China. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. RP Weng, XC (reprint author), Chinese Acad Sci, Inst Psychol, Lab Higher Brain Funct, Beijing 100101, Peoples R China. NR 11 TC 13 Z9 25 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 28 PY 1999 VL 96 IS 20 BP 11073 EP 11074 DI 10.1073/pnas.96.20.11073 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 241DY UT WOS:000082868500028 PM 10500129 ER PT J AU Smith, GCM Cary, RB Lakin, ND Hann, BC Teo, SH Chen, DJ Jackson, SP AF Smith, GCM Cary, RB Lakin, ND Hann, BC Teo, SH Chen, DJ Jackson, SP TI Purification and DNA binding properties of the ataxia-telangiectasia gene product ATM SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID DEPENDENT PROTEIN-KINASE; CATALYTIC SUBUNIT; FORCE MICROSCOPY; P53; KU; DAMAGE; PHOSPHORYLATION; LOCALIZATION; ACTIVATION; 3-KINASE AB The human neurodegenerative and cancer predisposition condition ataxia-telangiectasia is characterized at the cellular level by radiosensitivity, chromosomal instability, and impaired induction of ionizing radiation-induced cell cycle checkpoint controls. Recent work has revealed that the gene defective in ataxia-telangiectasia, termed ATM, encodes an approximate to 350-kDa polypeptide, ATM, that is a member of the phosphatidylinositol 3-kinase family. We show that ATM binds DNA and exploit this to purify ATM to near homogeneity. Atomic force microscopy reveals that ATM exists in two populations, with sizes consistent with monomeric and tetrameric states. Atomic force microscopy analyses also show that ATR I binds preferentially to DNA ends. This property is similar to that displayed by the DNA-dependent protein kinase catalytic subunit, a phosphatidylinositol 3-kinase family member that functions in DNA damage detection in conjunction with the DNA end binding protein Ku. Furthermore, purified ATM contains a kinase activity that phosphorylates serine-15 of p53 in a DNA-stimulated manner. These results provide a biochemical assay system for ATM, support genetic data indicating distinct roles for DNA-dependent protein kinase and ATM, and suggest how ATM may signal the presence of DNA damage to p53 and other downstream effectors. C1 Univ Cambridge, Wellcome Trust, Cambridge CB2 1QR, England. Univ Cambridge, Dept Zool, Cambridge CB2 1QR, England. Univ Calif Los Alamos Natl Lab, Div Life Sci, DNA Damage & Repair Grp, Los Alamos, NM 87545 USA. Univ Dundee, Dept Biochem, Canc Res Campaign Labs, Dundee DD1 4HN, Scotland. Univ Cambridge, Canc Res Campaign, Inst Canc & Dev Biol, Cambridge CB2 1QR, England. RP Jackson, SP (reprint author), Univ Cambridge, Wellcome Trust, Tennis Court Rd, Cambridge CB2 1QR, England. RI Teo, Soo-hwang/H-2353-2014; Dry, Kate/I-2328-2014 FU NCI NIH HHS [CA50519, R01 CA050519, R37 CA050519] NR 38 TC 128 Z9 132 U1 0 U2 1 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 SEP 28 PY 1999 VL 96 IS 20 BP 11134 EP 11139 DI 10.1073/pnas.96.20.11134 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 241DY UT WOS:000082868500041 PM 10500142 ER PT J AU Armitage, R Rubin, M Richardson, T O'Brien, N Chen, Y AF Armitage, R Rubin, M Richardson, T O'Brien, N Chen, Y TI Solid-state gadolinium-magnesium hydride optical switch SO APPLIED PHYSICS LETTERS LA English DT Article AB The optical switching properties of gadolinium-magnesium hydride have been demonstrated in a solid-state electrochromic device. With positive polarization of the hydride electrode, the visible reflectance approaches 35% with virtually zero transmission, while with negative polarization, the visible transmission exceeds 25% at 650 nm. The switching is reversible, with intermediate optical properties between the transparent and reflecting states. (C) 1999 American Institute of Physics. [S0003-6951(99)03239-8]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Opt Coating Lab Inc, Santa Rosa, CA 95407 USA. Hewlett Packard Labs, Palo Alto, CA 94304 USA. RP Armitage, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Mahalingam, Arjun/G-8586-2011 NR 6 TC 58 Z9 60 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 27 PY 1999 VL 75 IS 13 BP 1863 EP 1865 DI 10.1063/1.124853 PG 3 WC Physics, Applied SC Physics GA 237PY UT WOS:000082666300015 ER PT J AU Wong, WS Cho, Y Weber, ER Sands, T Yu, KM Kruger, J Wengrow, AB Cheung, NW AF Wong, WS Cho, Y Weber, ER Sands, T Yu, KM Kruger, J Wengrow, AB Cheung, NW TI Structural and optical quality of GaN/metal/Si heterostructures fabricated by excimer laser lift-off SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; GAN THIN-FILMS; GAAS; SILICON; GROWTH AB Gallium nitride (GaN) thin films grown on sapphire substrates were successfully bonded and transferred onto Si substrates using a Pd-In metallic bond. After bonding, a single 600 mJ/cm(2), 38 ns KrF (248 nm) excimer laser pulse was directed through the transparent sapphire followed by a low-temperature heat treatment to remove the substrate. Channeling-Rutherford backscattering measurements revealed the thickness of the defective interfacial region to be approximately 350 nm. The full width at half maximum, low-temperature (4 K), donor-bound exciton photoluminescence (PL) peak was larger by 25% on the exposed interfacial layer compared to the original GaN surface. Ion milling of the exposed interface to a depth of 400 nm was found to remove the interfacial layer and associated defects. The minimum channeling yield and PL linewidths from the exposed interface were found to be comparable to those obtained from the original GaN surface after ion milling. (C) 1999 American Institute of Physics. [S0003-6951(99)04539-8]. C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Appl Sci & Technol Grad Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Wong, WS (reprint author), Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. EM wsw@vivante.eecs.berkeley.edu RI Sands, Timothy/D-2133-2009; Yu, Kin Man/J-1399-2012 OI Sands, Timothy/0000-0001-9718-6515; Yu, Kin Man/0000-0003-1350-9642 NR 20 TC 47 Z9 55 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 27 PY 1999 VL 75 IS 13 BP 1887 EP 1889 DI 10.1063/1.124861 PG 3 WC Physics, Applied SC Physics GA 237PY UT WOS:000082666300023 ER PT J AU Li, JZ Lin, JY Jiang, HX Geisz, JF Kurtz, SR AF Li, JZ Lin, JY Jiang, HX Geisz, JF Kurtz, SR TI Persistent photoconductivity in Ga1-xInxNyAs1-y SO APPLIED PHYSICS LETTERS LA English DT Article ID GAN; RELAXATION; MODEL AB Electrical properties of unintentionally doped p-type Ga0.95In0.05N0.013As0.987 quaternary alloys grown by metal-organic vapor-phase epitaxy have been investigated by Hall-effect and photoconductivity measurements. Persistent photoconductivity (PPC) has been observed in this material at temperatures T < 320 K. The PPC buildup and decay kinetics have been systematically measured at different temperatures and photoexcitation energies and formulated in the context of lattice-relaxed deep levels (or AX-like centers). The parameters which characterize the AX centers in GaInNAs, namely, the thermal and optical ionization energies, hole capture barrier, and the Stokes shift, have been determined. Our results indicate that AX-like deep levels strongly influence the electronic properties of the GaInNAs quaternary system. (C) 1999 American Institute of Physics. [S0003-6951(99)01039-6]. C1 Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Li, JZ (reprint author), Kansas State Univ, Dept Phys, Cardwell Hall, Manhattan, KS 66506 USA. RI Lin, Jingyu/A-7276-2011; Jiang, Hongxing/F-3635-2011 OI Lin, Jingyu/0000-0003-1705-2635; Jiang, Hongxing/0000-0001-9892-4292 NR 19 TC 45 Z9 45 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 27 PY 1999 VL 75 IS 13 BP 1899 EP 1901 DI 10.1063/1.124865 PG 3 WC Physics, Applied SC Physics GA 237PY UT WOS:000082666300027 ER PT J AU Yan, Y Al-Jassim, MM Xu, Z Lu, X Viehland, D Payne, M Pennycook, SJ AF Yan, Y Al-Jassim, MM Xu, Z Lu, X Viehland, D Payne, M Pennycook, SJ TI Structure determination of a planar defect in SrBi2Ta2O9 SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; BEHAVIOR; CRYSTALS; MEMORIES AB The atomic structure of a planar defect with a (001) habit plane in single crystal layered perovskite SrBi2Ta2O9 is determined by high-resolution Z-contrast imaging. We found that the defect forms a structure, with two Sr-Ta-O perovskite blocks connected by a metallic Sr-2 plane, rather than a Bi2O2 layer as in the perfect crystal. This defect is expected to be an efficient hole trap and may have important implications for the electronic properties and the ferroelectric response of the SrBi2Ta2O9 material. (C) 1999 American Institute of Physics. [S0003-6951(99)03039-9]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Yan, Y (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. OI XU, Zhengkui/0000-0002-7465-8513 NR 16 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 27 PY 1999 VL 75 IS 13 BP 1961 EP 1963 DI 10.1063/1.124885 PG 3 WC Physics, Applied SC Physics GA 237PY UT WOS:000082666300048 ER PT J AU Kouznetsov, KA Borgmann, J Clarke, J AF Kouznetsov, KA Borgmann, J Clarke, J TI High-T-c second-order gradiometer for magnetocardiography in an unshielded environment SO APPLIED PHYSICS LETTERS LA English DT Article ID SQUID GRADIOMETER; JUNCTIONS; LAYER AB We have fabricated planar first-derivative gradiometers in which an asymmetric flux transformer patterned in a single-layer YBa2Cu3O7-x film is permanently bonded to a directly coupled magnetometer based on a dc superconducting quantum interference device (SQUID). The gradiometer base line is 48 mm. The common mode rejection of uniform magnetic fields is typically one part in a few hundred. The outputs of two such gradiometers are subtracted digitally to form a second-derivative gradiometer. Additionally, three orthogonal SQUID magnetometers are used to reduce the residual response to uniform magnetic fields to better than 100 ppm. The system is able to detect magnetic signals from a human heart in an unshielded environment. (C) 1999 American Institute of Physics. [S0003-6951(99)01339-X]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Kouznetsov, KA (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 16 TC 29 Z9 29 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 27 PY 1999 VL 75 IS 13 BP 1979 EP 1981 DI 10.1063/1.124891 PG 3 WC Physics, Applied SC Physics GA 237PY UT WOS:000082666300054 ER PT J AU Bannister, ME Djuric, N Woitke, O Dunn, GH Chung, YS Smith, ACH Wallbank, B Berrington, KA AF Bannister, ME Djuric, N Woitke, O Dunn, GH Chung, YS Smith, ACH Wallbank, B Berrington, KA TI Absolute cross sections for near-threshold electron-impact excitation of Be-like C(2+), N(3+), and O(4+) ions SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE excitation; collisions; merged beams; close coupling ID ENERGY-LOSS TECHNIQUE; 3S(2) S-1->3S3P P-3; COLLISIONAL EXCITATION; RESONANCE STRUCTURE; N=3 LEVELS; TRANSITIONS; BEAMS; RATES; IONIZATION; KR6+ AB Absolute total cross sections for electron-impact excitation of the Be-like C(2+), N(3+), and O(4+) ions have been measured near threshold using the merged electron-ion beams energy-loss (MEIBEL) technique and calculated using a close-coupling R-matrix (CCR) approach. The 2s(2) (1)S --> 2s2p (1)P(0) dipole-allowed. transition from the ground state was investigated for all three ions and satisfactory agreement between experiment and theory is found. In addition, calculations and measurements for the 2s2p (3)P(0) --> 2p(2) (3)P allowed transition from the metastable level of C(2+) are in excellent agreement. The sum of the cross sections for the 2s(2) (1)S --> 2s2p (3)P(0) and 2s2p (3)P(0) --> 2s2p (1)P(0) spin-forbidden transitions, not completely resolved by the MEIBEL technique, are measured for C(2+) and O(4+) and compared to CCR calculations scaled to account for the ground state and metastable fractions of the target ion beams. The results for these unresolved transitions are in reasonable agreement except for a resonance feature measured in the 2s2p (3)P(0) --> 2s2p (1)P(0) transition in C(2+) that is not predicted by theory. (C) 1999 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. Chungnam Natl Univ, Taejon 305764, South Korea. UCL, Dept Phys & Astron, London WC1E 6BT, England. St Francis Xavier Univ, Antigonish, NS B2G 2W5, Canada. Sheffield Hallam Univ, Sch Sci & Math, Sheffield S1 1WB, S Yorkshire, England. RP Bannister, ME (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. EM bannister@mail.phy.ornl.gov NR 27 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD SEP 27 PY 1999 VL 192 SI SI BP 39 EP 48 DI 10.1016/S1387-3806(99)00083-4 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 243EZ UT WOS:000082985200006 ER PT J AU McGuire, JH Godunov, AL Tolmanov, SG Schmidt-Bocking, H Dorner, R Mergel, V Dreizler, R Shore, BW AF McGuire, JH Godunov, AL Tolmanov, SG Schmidt-Bocking, H Dorner, R Mergel, V Dreizler, R Shore, BW TI Time ordering in fast double ionization SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE time ordering; electron correlation; few-electron transitions ID HIGH-ENERGY PHOTONS; SINGLE IONIZATION; CHARGED-PARTICLES; DOUBLE-EXCITATION; CROSS-SECTIONS; HELIUM; SCATTERING; COLLISIONS; PROTONS; HE AB We consider the role of time ordering in the production of multiply charged ions by examining the role of time ordering in two-electron transitions such as double ionization of atoms in fast ion-atom and photon-atom collisions. If two or more electrons are uncorrelated in space, then transitions of these electrons evolve independently in time. If the electrons are correlated, then the transition of one electron can affect the time evolution of the other electron. In the interaction picture correlation in time is carried by the part of the time-ordering operator T which is antisymmetric in time. It is this part of T that gives nonequal weight to the time ordering of the interactions causing the electron transitions. The antisymmetric part of T is nonzero only if electron correlation is present. Thus, correlation in time between transitions of different electrons is connected to spatial electron correlation due to the electron-electron interaction. We also note an invariance in the product of the time and charge symmetry of the projectile in fast ion-atom collisions. Consequently, effects of the antisymmetric part of T may be found in regions where there are substantial contributions antisymmetric in the projectile charge, Z (e.g. Z(3) contributions) to transition probabilities and cross sections, as evident in double ionization of atoms and molecules. (C) 1999 Elsevier Science B.V. C1 Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Frankfurt, Inst Kernphys, D-60486 Frankfurt, Germany. Univ Frankfurt, D-60054 Frankfurt, Germany. Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP McGuire, JH (reprint author), Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. RI Godunov, Alexander/G-4266-2011; Doerner, Reinhard/A-5340-2008 OI Doerner, Reinhard/0000-0002-3728-4268 NR 26 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD SEP 27 PY 1999 VL 192 SI SI BP 65 EP 73 DI 10.1016/S1387-3806(99)00055-X PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 243EZ UT WOS:000082985200008 ER PT J AU Church, DA Moehs, DP Bhatti, MI AF Church, DA Moehs, DP Bhatti, MI TI Precision and accuracy of lifetimes of metastable levels using the Kingdon trap technique SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE lifetimes; metastable levels; ion trap ID BEAM ION-TRAP; BERYLLIUM ISOELECTRONIC SEQUENCE; ARGON IONS; C-III; TRANSITIONS; LINES AB The accuracy of measurements of the lifetimes of metastable levels using a Kingdon ion trap technique is discussed with reference to the recent measurement of the transition rate from the excited 2s2p P-3(2) level of AR XV. Particular attention focused on the aspects of the Kingdon trap technique, which differed from competing alternatives and might apply differently to ground and excited terms. These differences are related to the corrections for quenching of the metastable level by ion-atom collisions, to the possible quenching by Stark mixing due to the higher electric field of the Kingdon trap, and to optical effects associated with the charging of a lens in the light collection system. No significant systematic corrections to present excited level measurements were identified. (C) 1999 Elsevier Science B.V. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Texas Pan Amer, Dept Phys & Geol, Edinburg, TX 78539 USA. RP Church, DA (reprint author), Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. NR 24 TC 8 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD SEP 27 PY 1999 VL 192 SI SI BP 149 EP 155 DI 10.1016/S1387-3806(99)00118-9 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 243EZ UT WOS:000082985200015 ER PT J AU Stolterfoht, N Bremer, JH Muino, RD AF Stolterfoht, N Bremer, JH Muino, RD TI Formation and cascading decay of hollow Ar atoms at a Si surface SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE hollow atoms; Auger transitions; electron spectroscopy ID HIGHLY-CHARGED IONS; AUGER-ELECTRON EMISSION; SLOW MULTICHARGED IONS; H-LIKE IONS; METAL-SURFACES; AL SURFACE; NE ATOMS; AU(111) SURFACE; ABOVE-SURFACE; MODEL AB Theoretical work was performed to investigate the formation and cascading decay of hollow Ar atoms during the interaction near a surface of Si. To exhibit the static aspect of hollow atom formation below the surface, the density functional theory was applied to evaluate results for electron charge density plots of atomic orbitals. To study the dynamic properties of hollow Ar atoms, a complex cascade model was developed treating the successive filling of the K, L, and M shells via Auger transitions and collisional charge transfer above the surface and in the bulk. Information is provided for the above- and below-surface contributions in previous experiments of Ar17+ impact on SiH using high-resolution x-ray spectroscopy. Clear evidence is given that the velocity-dependent filling of the M shell plays a significant role. (C) 1999 Elsevier Science B.V. C1 Hahn Meitner Inst Kernforsch Berlin GmbH, Bereich Festkorperphys, D-14109 Berlin, Germany. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Stolterfoht, N (reprint author), Hahn Meitner Inst Kernforsch Berlin GmbH, Bereich Festkorperphys, Glienicker Str 100, D-14109 Berlin, Germany. RI Diez Muino, Ricardo/C-9203-2009 OI Diez Muino, Ricardo/0000-0001-8593-0327 NR 38 TC 13 Z9 13 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD SEP 27 PY 1999 VL 192 SI SI BP 425 EP 436 DI 10.1016/S1387-3806(99)00106-2 PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 243EZ UT WOS:000082985200039 ER PT J AU Xie, JJ Chen, SP AF Xie, JJ Chen, SP TI Interaction potentials for vacancy-assisted As diffusion in silicon SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID ARSENIC-DOPED SILICON; ELECTRICAL DEACTIVATION; MOLECULAR-DYNAMICS; IMPURITY DIFFUSION; DOPANT DIFFUSION; COMPLEX; SYSTEMS; ENERGY AB A set of interaction potentials for vacancy-assisted As diffusion in silicon have been provided via first-principles pseudopotential calculations. Some important reactions such as As + V reversible arrow AsV, AsV + As reversible arrow As2V, AsV + V reversible arrow AsV2, As + As = As-2 as well as V+V reversible arrow Vt are considered. The results demonstrate that an AsV pair can attract another As due to the binding between the As and the vacancy. It is found that the existence of another As atom nearby greatly reduces the migration barrier for a vacancy moving between the two As atoms. The AsV can also attract another vacancy. The binding force mainly comes from the binding of two vacancies, rather than from that of the AsV pair. The potential energy diagrams obtained provide insight into the dynamical process of As-dopant redistribution in Si and the input for future atomistic diffusion simulations. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 29 TC 10 Z9 10 U1 0 U2 0 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 SEP 27 PY 1999 VL 11 IS 38 BP 7219 EP 7226 DI 10.1088/0953-8984/11/38/303 PG 8 WC Physics, Condensed Matter SC Physics GA 241BJ UT WOS:000082861900004 ER PT J AU Harrison, N Rzepniewski, E Singleton, J Gee, PJ Honold, MM Day, P Kurmoo, M AF Harrison, N Rzepniewski, E Singleton, J Gee, PJ Honold, MM Day, P Kurmoo, M TI The use of experimental data in constraining the tight-binding band parameters of quasi-two-dimensional organic molecular metals: application to alpha-(BEDT-TTF)(2)KHg(SCN)(4) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID DEPENDENT MAGNETORESISTANCE OSCILLATIONS; FERMI-SURFACE TOPOLOGY; QUANTUM INTERFERENCE; ELECTRONIC-STRUCTURE; MAGNETIC BREAKDOWN; SUPERCONDUCTOR KAPPA-(BEDT-TTF)(2)CU(NCS)(2); TEMPERATURE-DEPENDENCE; CRYSTAL-STRUCTURE; DENSITY WAVES; BEDT-TTF AB Whilst tight-binding bandstructure calculations are very successful in describing the Fermi-surface configuration in many quasi-two-dimensional organic molecular metals, the detailed topology of the predicted Fermi surface often differs from that measured in experiments. This is very significant when, for example, the formation of a density-wave state depends critically on details of the nesting of Fermi-surface sheets. These differences between theory and experiment probably result from the limited accuracy to which the pi-orbitals of the component molecules (which give rise to the transfer integrals of the tight-binding bandstructure) are known. In order to surmount this problem, we have derived a method whereby the transfer integrals within a tight-binding bandstructure model are adjusted until the detailed Fermi-surface topology is in good agreement with a wide variety of experimental data. The method is applied to the charge-transfer salt alpha-(BEDT-TTF)(2)KHg(SCN)(4), the Fermi surface of which has been the source of much speculation in recent years. The Fermi surface obtained differs in detail from previous bandstructure calculation findings. In particular, the quasi-one-dimensional component of the Fermi surface is more strongly warped; This implies that upon nesting of these sheets, significant pacts of the quasi-one-dimensional sheets remain, leading to a complicated Fermi-surface topology within the low-temperature, low-magnetic-field phase. In contrast to previous models of this phase, the model for the reconstructed Fermi surface in this work can explain virtually all of the current experimental observations in a consistent manner. C1 Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. UCL Royal Inst Great Britain, London W1X 4BS, England. RP Harrison, N (reprint author), Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. NR 40 TC 34 Z9 34 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 27 PY 1999 VL 11 IS 38 BP 7227 EP 7242 DI 10.1088/0953-8984/11/38/304 PG 16 WC Physics, Condensed Matter SC Physics GA 241BJ UT WOS:000082861900005 ER PT J AU Reynolds, MA Guzei, IA Logsdon, BC Thomas, LM Jacobson, RA Angelici, RJ AF Reynolds, MA Guzei, IA Logsdon, BC Thomas, LM Jacobson, RA Angelici, RJ TI Transition metal complexes of chromium, molybdenum, tungsten, and manganese containing eta(1)(S)-2,5-dimethylthiophene, benzothiophene, and dibenzothiophene ligands SO ORGANOMETALLICS LA English DT Article ID HYDRODESULFURIZATION CATALYSTS; CRYSTAL-STRUCTURE; THIOPHENE; REACTIVITY; MODELS; ADSORPTION; COORDINATION; MECHANISM; HDS; TH AB Ultraviolet photolysis of hexanes solutions containing the complexes M(CO)(6) (M = Cr, Mo, W) or CpMn(CO)(3) (Cp = eta(5)-C5H5) and excess thiophene (T*) (T* = 2,5-dimethylthiophene (2,5-Me2T), benzothiophene (BT), or dibenzothiophene (DBT)) produces the eta(1)(S)-T* complexes (CO)(5)M(eta(1)(S)-T*) 1-8 or Cp(CO)(2)Mn(eta(1)(S)-T*) 9-11, respectively. However, when T* = DBT and M = Mo, a mixture of two products results, which includes (CO)(5)Mo(eta(1)(S)-DBT), 4a, and the pi-complex (CO)(3)Mo(eta(6)-DBT), 4b, as detected by H-1 NMR spectroscopy. Only the complexes (CO)(5)W(eta(1)(S)-DBT) (1), (CO)(5)Cr(eta(1)(S)-DBT) (5), and Cp(CO)(2)Mn(eta(1)(S)-DBT) (9) were sufficiently stable (several days) to be isolated and characterized by elemental analyses. Rates of DBT ligand displacement by CO (1 atm) at room temperature decreased in the order 5 > 1 > 9. Single-crystal, X-ray structural determinations are reported for 1, 5, and 9. The tilt angle (theta) of the DBT ligand in these and related complexes is discussed in terms of pi-back-bonding to the DBT ligand. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Angelici, RJ (reprint author), Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. NR 48 TC 21 Z9 21 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP 27 PY 1999 VL 18 IS 20 BP 4075 EP 4081 DI 10.1021/om990322f PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 244CD UT WOS:000083033500021 ER PT J AU Klug, DD Tulk, CA Svensson, EC Loong, CK AF Klug, DD Tulk, CA Svensson, EC Loong, CK TI Dynamics and structural details of amorphous phases of ice determined by incoherent inelastic neutron scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID HYPERQUENCHED GLASSY WATER; UNCOUPLED O-H; SUPERCOOLED WATER; LIQUID WATER; X-RAY; DENSITY; STATES; SPECTROSCOPY; TRANSITION; PRESSURE AB incoherent-inelastic neutron scattering data are obtained over the energy range of lattice and internal vibrations of water molecules in phases of ice prepared by pressure-induced amorphization (high-density amorphous ice, hda), by thermal annealing of hda (low-density amorphous ice, Ida), and by rapidly cooling water, as well as in ice Ih and Ic. Hydrogen bonding interactions in Ida differ significantly from those in the glass obtained by rapid quenching, which has hydrogen-bond interactions characteristic of highly supercooled water. Hydrogen-bond interactions in hda are weaker than in the low-density phases. C1 Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Klug, DD (reprint author), Natl Res Council Canada, Steacie Inst Mol Sci, 100 Sussex Dr, Ottawa, ON K1A 0R6, Canada. RI Tulk, Chris/R-6088-2016 OI Tulk, Chris/0000-0003-3400-3878 NR 24 TC 56 Z9 57 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 27 PY 1999 VL 83 IS 13 BP 2584 EP 2587 DI 10.1103/PhysRevLett.83.2584 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600027 ER PT J AU Mao, GM Chen, D Karasz, FE Winokur, MJ AF Mao, GM Chen, D Karasz, FE Winokur, MJ TI Generalized anisotropic planar rotor model and its application to polymer intercalation compounds SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL-DOPED POLYACETYLENE; MEAN-FIELD THEORY; PHASE-TRANSITION; TRANSFORMATIONS; PHENYLENE; VINYLENE AB A diverse structural phase progression is observed in diffraction studies of an alkali-metal intercalated conducting polymer, poly(p-phenylene vinylene), as functions of both temperature and chemical potential. Despite the presence of translational displacements, extensive disorder, and other experimental host limitations, an equivalent heuristic structural counterpart appears in a phase diagram derived using a modified anisotropic planar rotor Hamiltonian (introduced and studied by Choi, Harris, and Mele). This model includes only rotational motions and therefore demonstrates that much of the underlying structural evolution is governed by only a few key degrees of freedom. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. RP Mao, GM (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Mao, Guomin/G-3933-2010 NR 21 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 27 PY 1999 VL 83 IS 13 BP 2588 EP 2591 DI 10.1103/PhysRevLett.83.2588 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600028 ER PT J AU Baskes, MI AF Baskes, MI TI Many-body effects in fcc metals: A Lennard-Jones embedded-atom potential SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-DYNAMICS; LIQUID; CRYSTALS; IMPURITIES; INTERFACE AB A simple analytic model that extends the Lennard-Jones potential into the many-body regime is proposed. The two parameter model draws on the embedded-atom method formalism. The model is used to calculate properties of an fee material, e.g., elastic constants, Bain transformation, and defect properties, as a function of many-body parameters. It is shown that the ground state structure of the model includes all of the common phases. The melting point of an fee material is shown to decrease significantly as the many-body interactions are increased. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Baskes, MI (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 32 TC 57 Z9 62 U1 0 U2 16 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 SEP 27 PY 1999 VL 83 IS 13 BP 2592 EP 2595 DI 10.1103/PhysRevLett.83.2592 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600029 ER PT J AU Aranson, IS Kopnin, NB Vinokur, VM AF Aranson, IS Kopnin, NB Vinokur, VM TI Nucleation of vortices by rapid thermal quench SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEFECT FORMATION; TRANSITION AB By numerical and analytical study of the time-dependent Ginzburg-Landau equation we show that vortex nucleation in superfluid He-3 by rapid thermal quench in the presence of superflow is dominated by a transverse instability of the moving normal-superfluid interface. Exact expressions for the instability threshold as a function of supercurrent density and the front velocity are found. C1 Argonne Natl Lab, Argonne, IL 60439 USA. LD Landau Theoret Phys Inst, Moscow 117334, Russia. RP Aranson, IS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Aranson, Igor/I-4060-2013 NR 9 TC 27 Z9 27 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 SEP 27 PY 1999 VL 83 IS 13 BP 2600 EP 2603 DI 10.1103/PhysRevLett.83.2600 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600031 ER PT J AU Ovesson, S Bogicevic, A Lundqvist, BI AF Ovesson, S Bogicevic, A Lundqvist, BI TI Origin of compact triangular islands in metal-on-metal growth SO PHYSICAL REVIEW LETTERS LA English DT Article ID HOMOEPITAXIAL GROWTH; DENDRITIC GROWTH; DIFFUSION; TEMPERATURE; AL(111); MECHANISM; DYNAMICS AB The microscopic origin of compact triangular islands on close-packed surfaces is identified using kinetic Monte Carlo simulations with energy barriers obtained from density-functional calculations. In contrast to earlier accounts, corner diffusion anisotropy is found to control the shape of compact islands at intermediate temperatures. We rationalize the correlation between the orientation of dendrites grown at low temperatures and triangular islands grown at higher temperatures, and explain why in some systems dendrites grow fat before turning compact. C1 Chalmers Univ Technol, Dept Appl Phys, S-41296 Gothenburg, Sweden. Univ Gothenburg, S-41296 Gothenburg, Sweden. Sandia Natl Labs, Dept Surface & Interface Sci, Albuquerque, NM 87185 USA. RP Ovesson, S (reprint author), Chalmers Univ Technol, Dept Appl Phys, S-41296 Gothenburg, Sweden. RI Lundqvist, Bengt/A-9013-2011 NR 21 TC 79 Z9 80 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 27 PY 1999 VL 83 IS 13 BP 2608 EP 2611 DI 10.1103/PhysRevLett.83.2608 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600033 ER PT J AU Creutz, M AF Creutz, M TI End states, ladder compounds, and domain-wall fermions SO PHYSICAL REVIEW LETTERS LA English DT Article ID EDGE STATES; LATTICE; QUARKS; QCD AB A magnetic field applied to a cross-linked ladder compound can generate isolated electronic states bound to the ends of the chain. After exploring the interference phenomena responsible, I discuss a connection co the domain-wall approach to chiral fermions in lattice gauge theory. The robust nature of the states under small variations of the bond strengths is tied to chiral symmetry and the multiplicative renormalization of fermion masses. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Creutz, M (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 12 TC 31 Z9 31 U1 6 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 27 PY 1999 VL 83 IS 13 BP 2636 EP 2639 DI 10.1103/PhysRevLett.83.2636 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600040 ER PT J AU Bar, M Hagberg, A Meron, E Thiele, U AF Bar, M Hagberg, A Meron, E Thiele, U TI Stratified spatiotemporal chaos in anisotropic reaction-diffusion systems SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEMATIC LIQUID-CRYSTALS; PATTERN-FORMATION; CHEMICAL WAVES; MEDIA AB Numerical simulations of two-dimensional pattern formation in an anisotropic bistable reaction-diffusion medium reveal a new dynamical state, stratified spatiotemporal chaos, characterized by strong correlations along one of the principal axes. Equations that describe the dependence of front motion on the angle illustrate the mechanism leading to stratified chaos. C1 Max Planck Inst Phys Komplexer Syst, D-01187 Dresden, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Ben Gurion Univ Negev, Jacob Blaustein Inst Desert Res, IL-84990 Sede Boqer, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84990 Sede Boqer, Israel. Univ Complutense Madrid, Inst Pluridisciplinar, E-28040 Madrid, Spain. RP Bar, M (reprint author), Max Planck Inst Phys Komplexer Syst, Nothnitzer Str 38, D-01187 Dresden, Germany. RI MERON, EHUD/F-1810-2012; Bar, Markus/B-8396-2011; thiele, uwe/B-6236-2008 OI Bar, Markus/0000-0002-6935-7759; thiele, uwe/0000-0001-7989-9271 NR 18 TC 10 Z9 10 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 SEP 27 PY 1999 VL 83 IS 13 BP 2664 EP 2667 DI 10.1103/PhysRevLett.83.2664 PG 4 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600047 ER PT J AU Ecke, RE AF Ecke, RE TI Comment on "Two scaling regimes for rotating Rayleigh-Benard convection" SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUMBER C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ecke, RE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 2 Z9 2 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 27 PY 1999 VL 83 IS 13 BP 2678 EP 2678 DI 10.1103/PhysRevLett.83.2678 PG 1 WC Physics, Multidisciplinary SC Physics GA 238HV UT WOS:000082705600052 ER PT J AU Schaffer, HW Mokler, PH Dunford, RW Kozhuharov, C Kramer, A Livingston, AE Ludziejewski, T Prinz, HT Rymuza, P Sarkadi, L Stachura, Z Stohlker, T Swiat, P Warczak, A AF Schaffer, HW Mokler, PH Dunford, RW Kozhuharov, C Kramer, A Livingston, AE Ludziejewski, T Prinz, HT Rymuza, P Sarkadi, L Stachura, Z Stohlker, T Swiat, P Warczak, A TI Two-photon decay in strong central fields observed for the case of He-like gold SO PHYSICS LETTERS A LA English DT Article ID ONE-ELECTRON ATOMS; 2-PHOTON DECAY; RATES; IONS; HYDROGENLIKE AB The photon energy differential shape of the second order matrix element for the two-photon (2E1) decay of the 1s2s(1)S(0) level in He-like gold has been measured. The results are in agreement with a recent fully relativistic calculation. The corresponding 2E1 matrix element deviates from those in lighter He-like systems due to the strong central field in a heavy two-electron ion. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Giessen, Inst Phys 1, D-35392 Giessen, Germany. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Frankfurt, Inst Kernphys, D-60486 Frankfurt, Germany. Univ Notre Dame, Notre Dame, IN 46556 USA. Inst Nucl Studies, PL-05400 Swierk, Poland. Inst Nucl Res, H-4001 Debrecen, Hungary. Inst Nucl Phys, PL-31342 Krakow, Poland. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. RP Mokler, PH (reprint author), Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. NR 16 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD SEP 27 PY 1999 VL 260 IS 6 BP 489 EP 494 DI 10.1016/S0375-9601(99)00540-X PG 6 WC Physics, Multidisciplinary SC Physics GA 245GG UT WOS:000083097400009 ER PT J AU Rubin, Y Sun, A Maxwell, R Bellin, A AF Rubin, Y Sun, A Maxwell, R Bellin, A TI The concept of block-effective macrodispersivity and a unified approach for grid-scale- and plume-scale-dependent transport SO JOURNAL OF FLUID MECHANICS LA English DT Article ID HETEROGENEOUS POROUS-MEDIA; CONDITIONAL PROBABILITIES; GROUNDWATER-FLOW; SOLUTE TRANSPORT; VELOCITY-FIELDS; DISPERSION; AQUIFERS; SIMULATION; PREDICTION; TIME AB We present a new approach for modelling macrodispersivity in spatially variable velocity fields, such as exist in geologically heterogeneous formations. Considering a spectral representation of the velocity, it is recognized that numerical models usually capture low-wavenumber effects, while the large-wavenumber effects, associated with subgrid block variability, are suppressed. While this suppression is avoidable if the heterogeneity is captured at minute detail, that goal is impossible to achieve in all but the most trivial cases. Representing the effects of the suppressed variability in the models is made possible using the proposed concept of block-effective macrodispersivity. A tensor is developed, which we refer to as the block-effective macrodispersivity tensor, whose terms are functions of the characteristic length scales of heterogeneity, as well as the length scales of the model's homogenized areas, or numerical grid blocks. Closed-form expressions are developed for small variability in the log-conductivity and unidirectional mean flow, and are tested numerically. The use of the block-effective macrodispersivities allows conditioning of the velocity field on the measurements on the one hand, while accounting for the effects of unmodelled heterogeneity on the other, in a numerically reasonable set-up. It is shown that the effects of the grid scale are similar to those of the plume scale in terms of filtering out the effects of portions of the velocity spectrum. Hence it is easy to expand the concept of the block-effective dispersivity to account for the scale of the solute body and the pore-scale dispersion. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Trent, Dept Civil & Environm Engn, I-38100 Trent, Italy. RP Rubin, Y (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RI Sun, Alexander/A-9959-2011; Maxwell, Reed/D-7980-2013; Bellin, Alberto/F-8955-2013 OI Maxwell, Reed/0000-0002-1364-4441; Bellin, Alberto/0000-0002-7348-8313 NR 34 TC 68 Z9 67 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD SEP 25 PY 1999 VL 395 BP 161 EP 180 DI 10.1017/S0022112099005868 PG 20 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 241HA UT WOS:000082875500006 ER PT J AU Cate, JH Yusupov, MM Yusupova, GZ Earnest, TN Noller, HF AF Cate, JH Yusupov, MM Yusupova, GZ Earnest, TN Noller, HF TI X-ray crystal structures of 70S ribosome functional complexes SO SCIENCE LA English DT Review ID ESCHERICHIA-COLI RIBOSOME; TRANSFER-RNA BINDING; NUCLEAR MAGNETIC-RESONANCE; P-SITE; THERMUS-THERMOPHILUS; A-SITE; BACILLUS-STEAROTHERMOPHILUS; CRYOELECTRON MICROSCOPY; 3-DIMENSIONAL STRUCTURE; PROMOTES TRANSLOCATION AB Structures of 70S ribosome complexes containing messenger RNA and transfer RNA (tRNA), or tRNA analogs, have been solved by x-ray crystallography at up to 7.8 angstrom resolution. Many details of the interactions between tRNA and the ribosome, and of the packing arrangements of ribosomal RNA (rRNA) helices in and between the ribosomal subunits, can be seen. Numerous contacts are made between the 30S subunit and the P-tRNA anticodon stem-loop; in contrast, the anticodon region of A-tRNA is much more exposed. A complex network of molecular interactions suggestive of a functional relay is centered around the Long penultimate stem of 16S rRNA at the subunit interface, including interactions involving the "switch" helix and decoding site of 16S rRNA, and RNA bridges from the 50S subunit. C1 Univ Calif Santa Cruz, Sinsheimer Labs, Ctr Mol Biol RNA, Santa Cruz, CA 95064 USA. Lawrence Berkeley Lab, Phys Biosci Div, Macromol Crystallog Facil, Berkeley, CA 94720 USA. RP Cate, JH (reprint author), MIT, Whitehead Inst Biomed Res, Cambridge, MA 02142 USA. RI Yusupov, Marat/I-6126-2013; Yusupova , Gulnara/E-1877-2014 OI Yusupov, Marat/0000-0001-5544-0597; FU NIGMS NIH HHS [GM-17129, GM-59140] NR 125 TC 474 Z9 492 U1 2 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 SEP 24 PY 1999 VL 285 IS 5436 BP 2095 EP 2104 DI 10.1126/science.285.5436.2095 PG 10 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 238VF UT WOS:000082734300034 PM 10497122 ER PT J AU Weitering, HH Carpinelli, JM Melechko, AP Zhang, JD Bartkowiak, M Plummer, EW AF Weitering, HH Carpinelli, JM Melechko, AP Zhang, JD Bartkowiak, M Plummer, EW TI Defect-mediated condensation of a charge density wave SO SCIENCE LA English DT Article ID SCANNING TUNNELING MICROSCOPY; TRANSITION; PHASE; SURFACE; INTERFACE; DISORDER; SYSTEMS AB Symmetry, dimensionality, and disorder play a pivotal role in critical phenomena. The atomic imaging capabilities of the scanning tunneling microscope were used to directly visualize the interaction between charge density oscillations and Lattice defects in a two-dimensional charge density wave (CDW) system, point defects act as nucleation centers of the CDW, which, as the temperature is Lowered, results in the formation of pinned CDW domains that are separated by atomically abrupt charge boundaries. Incomplete freezing of substitutional disorder at low temperature indicates a novel CDW-mediated hopping of pinning centers. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Florida Int Univ, Dept Phys, Miami, FL 33199 USA. RP Weitering, HH (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RI Melechko, Anatoli/B-8820-2008 NR 22 TC 89 Z9 90 U1 2 U2 23 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 24 PY 1999 VL 285 IS 5436 BP 2107 EP 2110 DI 10.1126/science.285.5436.2107 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 238VF UT WOS:000082734300036 ER PT J AU Valla, T Fedorov, AV Johnson, PD Wells, BO Hulbert, SL Li, Q Gu, GD Koshizuka, N AF Valla, T Fedorov, AV Johnson, PD Wells, BO Hulbert, SL Li, Q Gu, GD Koshizuka, N TI Evidence for quantum critical behavior in the optimally doped cuprate Bi2Sr2CaCu2O8+delta SO SCIENCE LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; T-C SUPERCONDUCTORS; NORMAL-STATE; ELECTRONIC-STRUCTURE; GAP ANISOTROPY; PSEUDOGAP AB The photoemission Line shapes of the optimally doped cuprate Bi2Sr2CaCu2O8+delta were studied in the direction of a node in the superconducting order parameter by means of very high resolution photoemission spectroscopy. The peak width or inverse lifetime of the excitation displays a Linear temperature dependence, independent of: binding energy, for small energies, and a Linear energy dependence, independent of temperature, for Large binding energies. This behavior is unaffected by the superconducting transition, which is an indication that the nodal states play no role in the superconductivity. Temperature-dependent scaling suggests that the system displays quantum critical behavior. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Univ New S Wales, Sch Phys, Kensington, NSW 2033, Australia. ISTEC, Superconduct Res Lab, Koto Ku, Tokyo 135, Japan. RP Valla, T (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 28 TC 407 Z9 409 U1 5 U2 46 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 SEP 24 PY 1999 VL 285 IS 5436 BP 2110 EP 2113 DI 10.1126/science.285.5436.2110 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 238VF UT WOS:000082734300037 ER PT J AU Caffee, MW Hudson, GU Velsko, C Huss, GR Alexander, EC Chivas, AR AF Caffee, MW Hudson, GU Velsko, C Huss, GR Alexander, EC Chivas, AR TI Primordial noble cases from Earth's mantle: Identification of a primitive volatile component SO SCIENCE LA English DT Article ID STATE UPPER-MANTLE; CO2 WELL GAS; MASS FRACTIONATION; EXCESS XE-129; EARLY HISTORY; XENON; NEON; EVOLUTION; ORIGIN; CONSTRAINTS AB Carbon dioxide well gases in Colorado, New Mexico, and South Australia show excesses of Xe124-128 correlated with I-129-derived Xe-129 and Ne-20/Ne-22 ratios that are higher than the atmospheric Ne-20/Ne-22 ratio. The xenon isotopic data indicate the presence of a solarlike component deep within Earth. The presence of this component in crustal and upper mantle reservoirs may be explained by a steady-state transport of noble gases from the Lower mantle, which still retains much of its juvenile volatile inventory. These measurements also indicate that the mantle source of these noble gases in the carbon dioxide well gases cannot be the source of Earth's present atmosphere. The variations observed in Xe-129/Xe-130 between solar wind xenon, Earth's atmosphere, and mantle samples may be generated by variations of iodine/xenon in terrestrial reservoirs, as opposed to rapid early degassing. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA. Univ Wollongong, Sch Geosci, Wollongong, NSW 2522, Australia. RP Caffee, MW (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. RI Chivas, Allan/B-4242-2013; Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 59 TC 56 Z9 56 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 SEP 24 PY 1999 VL 285 IS 5436 BP 2115 EP 2118 DI 10.1126/science.285.5436.2115 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 238VF UT WOS:000082734300039 ER PT J AU Feller, D AF Feller, D TI Strength of the benzene-water hydrogen bond SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID CONFIGURATION-INTERACTION CALCULATIONS; CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; BENCHMARK CALCULATIONS; DIATOMIC HYDRIDES; ENERGIES; COMPLEXES; CLUSTERS; SPECTRA AB Very large basis set, correlated calculations of the benzene-water complex predict a geometry in which the water molecule sits above the aromatic ring with oxygen pointed away from the benzene center of mass. The purely electronic binding energy, in the complete basis set limit, was found to be -3.9 +/- 0.2 kcal/mol, or only 20% weaker than the water-water interaction. When zero-point energies are included, the Delta E-0(0 K) values are identical within their estimated uncertainties. Core/valence and higher-order correlation recovery via coupled cluster calculations were found to play a minor role. The present Delta E-0(0 K) value of -2.9 +/- 0.2 kcal/mol is in good agreement with a recent threshold photoionization experiment that yielded -2.4 +/- 0.1 kcal/mol. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Feller, D (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-91, Richland, WA 99352 USA. NR 36 TC 119 Z9 119 U1 0 U2 9 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 SEP 23 PY 1999 VL 103 IS 38 BP 7558 EP 7561 DI 10.1021/jp991932w PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 239RF UT WOS:000082782900002 ER PT J AU Dhanasekaran, T Grodkowski, J Neta, P Hambright, P Fujita, E AF Dhanasekaran, T Grodkowski, J Neta, P Hambright, P Fujita, E TI p-terphenyl-sensitized photoreduction of CO2 with cobalt and iron porphyrins. Interaction between CO and reduced metalloporphyrins SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-METAL COMPLEXES; CARBON-DIOXIDE ACTIVATION; ELECTROCATALYTIC REDUCTION; ELECTROCHEMICAL REDUCTION; PHOTOCHEMICAL REDUCTION; HOMOGENEOUS CATALYSIS; FREE-RADICALS; ONE-ELECTRON; MACROCYCLES; POTENTIALS AB Iron and cobalt porphyrins (FeP and CoP) are utilized as electron-transfer mediators to effect photochemical reduction of CO2 in homogeneous solutions. The species that activate and reduce CO2 are the (FeP)-P-0 and (CoP)-P-0 formed by reduction of the starting materials. Reduction of the metalloporphyrins (MP) is achieved by photolysis in dimethylformamide or acetonitrile solutions containing triethylamine (TEA) as a reductive quencher. The photoreduction is efficient for the (MP)-P-III --> (MP)-P-II stage and probably occurs by an intramolecular electron transfer from an axially bound TEA. However, TEA does not bind to the reduced metal complexes, and the quantum efficiency is much lower for the subsequent reduction steps. Considerably higher quantum yields are obtained by adding p-terphenyl (TP) as a sensitizer. TP is very effectively photoreduced by TEA to form the radical anion, TP.-, which has a sufficiently negative reduction potential to reduce (CoP)-P-I and (FeP)-P-I rapidly to their MOP state. The rate constants for these reactions, determined by pulse radiolysis, are found to be nearly diffusion-controlled. The quantum yield for the reduction of (MP)-P-II to (MP)-P-I and for reduction of CO2 to CO are increased by more than an order of magnitude in the presence of TP. Side reactions involve hydrogenation of the porphyrin ring and production of Hz. The hydrogenated porphyrins also catalyze reduction of CO2, but the photochemical production of CO eventually stops. This limit on catalytic activity is due to destruction of the porphyrin macrocycle and accumulation of CO. CO can bind strongly to (FeP)-P-II and to (FeP)-P-I but not to (FeP)-P-0, as demonstrated by electrochemical measurements and by optical spectra of the species produced by sodium reduction in tetrahydrofuran in the presence and absence of CO. Although binding of CO to (FeP)-P-II and FeIP should not interfere with the formation of (FeP)-P-0, the active catalyst, the potential for reduction of (FeP)-P-I to (FeP)-P-0 becomes more negative. However, CO probably binds to the hydrogenated products thereby inhibiting the catalytic process. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Neta, P (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Fujita, Etsuko/D-8814-2013 NR 40 TC 65 Z9 65 U1 4 U2 37 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 SEP 23 PY 1999 VL 103 IS 38 BP 7742 EP 7748 DI 10.1021/jp991423u PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 239RF UT WOS:000082782900027 ER PT J AU Cowin, JP Iedema, MJ AF Cowin, JP Iedema, MJ TI Reply to comment on "Ferroelectricity in water ice" SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PHASE-TRANSITION; DIFFRACTION; XI C1 Pacific NW Lab, Richland, WA 99352 USA. RP Cowin, JP (reprint author), Pacific NW Lab, Box 999,M-S K8-88, Richland, WA 99352 USA. NR 14 TC 7 Z9 7 U1 3 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 23 PY 1999 VL 103 IS 38 BP 8194 EP 8194 DI 10.1021/jp9911144 PG 1 WC Chemistry, Physical SC Chemistry GA 239RH UT WOS:000082783100024 ER PT J AU Orenstein, J AF Orenstein, J TI High-temperature superconductivity - Electrons pair themselves SO NATURE LA English DT Editorial Material ID NEUTRON-SCATTERING; FLUX-QUANTIZATION; YBA2CU3O7 C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Orenstein, J (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM joeo@ux5.lbl.gov RI Orenstein, Joseph/I-3451-2015 NR 11 TC 10 Z9 10 U1 0 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 23 PY 1999 VL 401 IS 6751 BP 333 EP + DI 10.1038/43801 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 240JJ UT WOS:000082822600032 PM 16862101 ER PT J AU Zhang, JZ Harbottle, G Wang, CS Kong, ZC AF Zhang, JZ Harbottle, G Wang, CS Kong, ZC TI Oldest playable musical instruments found at Jiahu early Neolithic site in China SO NATURE LA English DT Article AB Excavations at the early Neolithic site of Jiahu(1,2) in Henan Province, China have produced what may be the earliest complete, playable, tightly-dated multinote musical instruments. Jiahu was occupied from 7000 BC to 5700 BC, considerably antedating the well known Peiligang culture(3-5). Here we describe six exquisitely made complete flutes which were found in radiocarbon-dated excavation layers, along with fragments of perhaps 30 more. The flutes are made from the ulnae of the red-crowned crane (Grus japonensis Millen) and have 5, 6, 7 and 8 holes. The best preserved flute has been played and tonally analysed. In addition to early musical artefacts, the archaeological record at Jiahu(1,2) contains important information on the very foundations of Chinese society. We describe the archaeological characteristics of the Jiahu site, details concerning its dating, its place in the prehistory of the Chinese Neolithic, the ethnicity of its population and the results of a tonal analysis of a nearly 9,000-year-old musical instrument found there. C1 Univ Sci & Technol China, Archaeometry Lab, Hefei 230026, Anhui, Peoples R China. Inst Cultural Rel & Archaeol Henan Province, Zhengzhou 450000, Henan, Peoples R China. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Acad Sinica, Inst Bot, Paleobot Lab, Beijing 100080, Peoples R China. RP Harbottle, G (reprint author), Univ Sci & Technol China, Archaeometry Lab, Hefei 230026, Anhui, Peoples R China. NR 14 TC 33 Z9 36 U1 2 U2 23 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 23 PY 1999 VL 401 IS 6751 BP 366 EP 368 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 240JJ UT WOS:000082822600048 PM 16862110 ER PT J AU Johnson, RD Liu, N Jasin, M AF Johnson, RD Liu, N Jasin, M TI Mammalian XRCC2 promotes the repair of DNA double-strand breaks by homologous recombination SO NATURE LA English DT Article ID EMBRYONIC STEM-CELLS; IONIZING-RADIATION; RAD57 PROTEINS; GENE; RESISTANCE; ENDONUCLEASE; DISRUPTION; EXPRESSION; MEMBER; FAMILY AB The repair of DNA double-strand breaks is essential for cells to maintain their genomic integrity. Two major mechanisms are responsible for repairing these breaks in mammalian cells, nonhomologous end-joining (NHEJ) and homologous recombination (HR)(1,2): the importance of the former in mammalian cells is well established(3), whereas the role of the latter is just emerging, Homologous recombination is presumably promoted by an evolutionarily conserved group of genes termed the Rad52 epistasis (4-11). An essential component of the HR pathway is the group strand-exchange protein, known as RecA in bacteria(8) or Rad51 in yeast(6). Several mammalian genes have been implicated in repair by homologous recombination on the basis of their sequence homology to yeast Rad51 (ref. 11): one of these is human XRCC2 (refs 12, 13). Here we show that XRCC2 is essential for the efficient repair of DNA double-strand breaks by homologous recombination between sister chromatids, We find that hamster cells deficient in XRCC2 show more than a 100-fold decrease in HR induced by double-strand breaks compared with the parental cell line. This defect is corrected to almost wild-type levels by transient transfection with a plasmid expressing XRCC2. The repair defect in XRCC2 mutant cells appears to be restricted to recombinational repair because NHEJ is normal. We conclude that XRCC2 is involved in the repair of DNA double-strand breaks by homologous recombination. C1 Mem Sloan Kettering Canc Ctr, Cell Biol Program, New York, NY 10021 USA. Cornell Univ, Grad Sch Med Sci, New York, NY 10021 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Jasin, M (reprint author), Mem Sloan Kettering Canc Ctr, Cell Biol Program, 1275 York Ave, New York, NY 10021 USA. NR 29 TC 238 Z9 244 U1 2 U2 8 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 23 PY 1999 VL 401 IS 6751 BP 397 EP 399 DI 10.1038/43935 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 240JJ UT WOS:000082822600057 PM 10517641 ER PT J AU Bonet, M Phillips, C Warnow, T Yooseph, S AF Bonet, M Phillips, C Warnow, T Yooseph, S TI Constructing evolutionary trees in the presence of polymorphic characters SO SIAM JOURNAL ON COMPUTING LA English DT Article DE algorithms; graphs; evolutionary trees ID TRIANGULATING 3-COLORED GRAPHS; COMPUTATIONAL-COMPLEXITY; PHYLOGENETIC SYSTEMATICS; COMPATIBILITY; ALGORITHM; PARSIMONY; SPACE; TIME AB Most phylogenetics literature and construction methods based upon characters presume monomorphism (one state per character per species), yet polymorphism (multiple states per character per species) is well documented in both biology and historical linguistics. In this paper we consider the problem of inferring evolutionary trees for polymorphic characters. We show efficient algorithms for the construction of perfect phylogenies from polymorphic data. These methods have been used to help construct the evolutionary tree proposed by Warnow, Ringe, and Taylor for the Indo-European family of languages and presented by invitation at the National Academy of Sciences in November 1995. C1 Univ Politecn Cataluna, Dept Comp Sci, E-08028 Barcelona, Spain. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Penn, Dept Comp & Informat Sci, Philadelphia, PA 19104 USA. RP Univ Politecn Cataluna, Dept Comp Sci, E-08028 Barcelona, Spain. EM bonet@goliat.upc.es; caphill@cs.sandia.gov; tandy@central.cis.upenn.edu; yooseph@gradient.cis.upenn.edu OI Bonet, Maria Luisa/0000-0003-1646-7177 NR 40 TC 3 Z9 3 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0097-5397 EI 1095-7111 J9 SIAM J COMPUT JI SIAM J. Comput. PD SEP 22 PY 1999 VL 29 IS 1 BP 103 EP 131 DI 10.1137/S0097539796324636 PG 29 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA 242PD UT WOS:000082948700005 ER PT J AU Lin, CJ More, JJ AF Lin, CJ More, JJ TI Incomplete Cholesky factorizations with limited memory SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE preconditioners; conjugate gradients; sparsity; memory constraints; trust region; optimization ID PRECONDITIONED CONJUGATE GRADIENTS; LINEAR ELASTICITY; MATRIX; OPTIMIZATION; MINIMIZATION; EQUATIONS; SYSTEMS; SETS AB We propose an incomplete Cholesky factorization for the solution of large-scale trust region subproblems and positive definite systems of linear equations. This factorization depends on a parameter p that specifies the amount of additional memory (in multiples of n, the dimension of the problem) that is available; there is no need to specify a drop tolerance. Our numerical results show that the number of conjugate gradient iterations and the computing time are reduced dramatically for small values of p. We also show that in contrast with drop tolerance strategies, the new approach is more stable in terms of number of iterations and memory requirements. C1 Natl Taiwan Univ, Dept Comp Sci & Informat Engn, Taipei 106, Taiwan. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Lin, CJ (reprint author), Natl Taiwan Univ, Dept Comp Sci & Informat Engn, Taipei 106, Taiwan. EM cjlin@sie.ntu.tw; more@mcs.anl.gov OI Lin, Chih-Jen/0000-0003-4684-8747 NR 45 TC 71 Z9 71 U1 1 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD SEP 22 PY 1999 VL 21 IS 1 BP 24 EP 45 DI 10.1137/S1064827597327334 PG 22 WC Mathematics, Applied SC Mathematics GA 240MY UT WOS:000082830800002 ER PT J AU Torres, DJ Coutsias, EA AF Torres, DJ Coutsias, EA TI Pseudospectral solution of the two-dimensional Navier-Stokes equations in a disk SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE spectral methods; coordinate singularity; parallel ID ORDINARY DIFFERENTIAL-EQUATIONS; INCOMPRESSIBLE FLUID-FLOW; COORDINATE SINGULARITIES; SPECTRAL METHOD; CIRCULAR BASIN; POLAR; APPROXIMATION; GEOMETRIES; MODEL AB An efficient and accurate algorithm for solving the two-dimensional(2D) incompressible Navier-Stokes equations on a disk with no-slip boundary conditions is described. The vorticity-stream function formulation of these equations is used, and spatially the vorticity and stream functions are expressed as Fourier-Chebyshev expansions. The Poisson and Helmholtz equations which arise from the implicit-explicit time marching scheme are solved as banded systems using a post-conditioned spectral tau-method. The polar coordinate singularity is handled by expanding fields radially over the entire diameter using a parity modified Chebyshev series and building partial regularity into the vorticity. The no-slip boundary condition is enforced by transferring one of the two boundary conditions imposed on the stream function onto the vorticity via a solvability constraint. Significant gains in run times were realized by parallelizing the code in message passage interface (MPI). C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Math & Stat, Albuquerque, NM 87131 USA. RP Torres, DJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. OI Coutsias, Evangelos/0000-0003-2910-9125 NR 24 TC 14 Z9 14 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD SEP 22 PY 1999 VL 21 IS 1 BP 378 EP 403 DI 10.1137/S1064827597330157 PG 26 WC Mathematics, Applied SC Mathematics GA 240MY UT WOS:000082830800018 ER PT J AU Konze, WV Scott, BL Kubas, GJ AF Konze, WV Scott, BL Kubas, GJ TI First example of B-C bond cleavage in the BArF (B[C6H3(CF3)(2)-3,5](4)) anion mediated by a transition metal species, trans-[(Ph3P)(2)Pt(Me)(OEt2)](+) SO CHEMICAL COMMUNICATIONS LA English DT Article ID COMPLEXES; ACTIVATION; ALKYL AB The first example of transition metal-mediated decomposition of the widely used BArF anion (BArF = B[C6H3(CF3)(2)-3,5](4)) has been accomplished by mild heating of the cationic platinum complex trans-[(Ph3P)(2)Pt(Me)(OEt2)](+)(BArF)(-) in low-coordinating solvents to form the diarylated product trans-(Ph3P)(2)Pt(Ar-F)(2) in good yield, thus demonstrating that such non-interacting anions can react with electrophilic transition metal complexes. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Kubas, GJ (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, MS J514, Los Alamos, NM 87545 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 10 TC 41 Z9 41 U1 1 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD SEP 21 PY 1999 IS 18 BP 1807 EP 1808 DI 10.1039/a902274k PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 236EJ UT WOS:000082585000014 ER PT J AU Matzger, AJ Shim, M Vollhardt, KPC AF Matzger, AJ Shim, M Vollhardt, KPC TI The crystal structure of 5,6,11,12,17,18-hexadehydro-1,4,7,10,13,16-hexaethynyltribenzo[a,e,i]cyc lododecene tetrahydrofuran solvate: a case of high organization enforced by chelating alkyne C-H center dot center dot center dot O hydrogen bonding SO CHEMICAL COMMUNICATIONS LA English DT Article AB The crystal structure of the novel title dehydrobenzoannulene reveals supramolecular organization of the hydrocarbon around the occluded solvent molecules induced by novel multiple chelating alkyne C-H ... O hydrogen bonds. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Vollhardt, KPC (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Shim, Moonsub/A-7875-2009; Matzger, Adam/G-7497-2016 OI Shim, Moonsub/0000-0001-7781-1029; Matzger, Adam/0000-0002-4926-2752 NR 18 TC 18 Z9 19 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD SEP 21 PY 1999 IS 18 BP 1871 EP 1872 DI 10.1039/a905312c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 236EJ UT WOS:000082585000046 ER PT J AU Catanesi, G Contalbrigo, M Cervera-Villanueva, A De Santo, A Silva, EDE Gibin, D Gomez-Cadenas, JJ Huta, W Kokkonen, J LaCaprara, S Lisowski, B Litmaath, M Radicioni, E Ricciardi, S Runolfsson, O Simone, S Stiegler, U AF Catanesi, G Contalbrigo, M Cervera-Villanueva, A De Santo, A Silva, EDE Gibin, D Gomez-Cadenas, JJ Huta, W Kokkonen, J LaCaprara, S Lisowski, B Litmaath, M Radicioni, E Ricciardi, S Runolfsson, O Simone, S Stiegler, U TI A silicon tracker for track extrapolation into nuclear emulsions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE silicon; tracker; emulsion ID MICROSTRIP DETECTORS; SEARCH; TARGET AB This paper describes the construction of a silicon tracker built to investigate how well silicon detectors can predict the position of particles in nuclear emulsions over a large area. The tracker consists of 72 single-sided silicon microstrip detectors with a total surface of 0.13 m(2) distributed over four layers, providing two x and two y coordinate measurements. The set-up was installed in a CERN PS pion beam in September 1997. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Bari, Bari, Italy. Ist Nazl Fis Nucl, I-70126 Bari, Italy. Univ Padua, Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. CERN, Div PPE, CH-1211 Geneva 23, Switzerland. Univ Dortmund, Dortmund, Germany. RP Silva, EDE (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM eduardo.do.couto.e.silva@cenr.ch RI Gomez Cadenas, Juan Jose/L-2003-2014 OI Gomez Cadenas, Juan Jose/0000-0002-8224-7714 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 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 21 PY 1999 VL 434 IS 2-3 BP 218 EP 226 DI 10.1016/S0168-9002(99)00494-5 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 237HY UT WOS:000082650900003 ER PT J AU Arena, V Boca, G Bonomi, G Cheung, HWK Chung, YS Gianini, G Gourlay, SA Gray, K Hansen, S Lee, KB Liguori, G Malvezzi, S Marchesotti, M Merlo, M Pantea, D Ratti, SP Riccardi, C Sala, A Viola, L Vitulo, P AF Arena, V Boca, G Bonomi, G Cheung, HWK Chung, YS Gianini, G Gourlay, SA Gray, K Hansen, S Lee, KB Liguori, G Malvezzi, S Marchesotti, M Merlo, M Pantea, D Ratti, SP Riccardi, C Sala, A Viola, L Vitulo, P TI Description and performance of the FOCUS (E831) hadron calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID E687 AB An iron-scintillator tile calorimeter with tower readout geometry was constructed for the photoproduction experiment FOCUS (E831) at Fermilab. This experiment ran in the 1996-1997 Fermilab-fixed target program using a wide band photon beam with an average energy of 170 GeV. The hadron calorimeter was used in an online trigger. A description of this tile sampling calorimeter is given and its performance described. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Pavia, Dip Fis Nucl & Teor, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Fermilab, Batavia, IL 60510 USA. Korea Univ, Seoul 136701, South Korea. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Natl Inst Phys & Nucl Engn, Bucharest, Romania. RP Bonomi, G (reprint author), Univ Brescia, Dip Chim & Fis Ingn & Mat, I-25123 Brescia, Italy. RI Bonomi, Germano/G-4236-2010; Gianini, Gabriele/M-5195-2014 OI Bonomi, Germano/0000-0003-1618-9648; Gianini, Gabriele/0000-0001-5186-0199 NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 21 PY 1999 VL 434 IS 2-3 BP 271 EP 278 DI 10.1016/S0168-9002(99)00501-X PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 237HY UT WOS:000082650900008 ER PT J AU Parker, B Smirnov, NL Tkachenko, LM AF Parker, B Smirnov, NL Tkachenko, LM TI Development of septum quadrupole prototype for DESY upgrading luminosity SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB In the frames of collaboration between IHEP and DESY the prototype of the septum quadrupole based on existing in DESY QC quadrupole has been developed, manufactured and tested in IHEP. The main goal of this R&D was to choose a magnet configuration including a septum plate, a septum notch for the electron beam and trim-coils matching to specify and further apply in a full-scale magnet. The ingenious magnetic correcting system allowing one to get a high field quality of a few units 10(-4) inside the operating range of the proton beam has been suggested. A chosen optimal geometry of the reflecting iron plate provides a required field magnitude along the electron beam path as well. The computer simulation of various geometric distortions influencing on the field quality has been performed and, as a result, the tolerances to the production accuracy have been formulated. These analyses displayed very strict requirements to both the manufacturing accuracy and magnetic properties of the septum plate steel. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Protvino High Energy Phys Inst, Protvino 142284, Moscow Region, Russia. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Tkachenko, LM (reprint author), Protvino High Energy Phys Inst, Protvino 142284, Moscow Region, Russia. NR 3 TC 1 Z9 1 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 SEP 21 PY 1999 VL 434 IS 2-3 BP 297 EP 302 DI 10.1016/S0168-9002(99)00515-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 237HY UT WOS:000082650900010 ER PT J AU Schmid, GJ Deleplanque, MA Lee, IY Stephens, FS Vetter, K Clark, RM Diamond, RM Fallon, P Macchiavelli, AO MacLeod, RW AF Schmid, GJ Deleplanque, MA Lee, IY Stephens, FS Vetter, K Clark, RM Diamond, RM Fallon, P Macchiavelli, AO MacLeod, RW TI A gamma-ray tracking algorithm for the GRETA spectrometer (vol 430, pg 69, 1999) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Correction C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Schmid, GJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 21 PY 1999 VL 434 IS 2-3 BP 481 EP 481 DI 10.1016/S0168-9002(99)00754-8 PG 1 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 237HY UT WOS:000082650900029 ER PT J AU Schlamp, S Cummings, EB Hornung, HG AF Schlamp, S Cummings, EB Hornung, HG TI Beam misalignments and fluid velocities in laser-induced thermal acoustics SO APPLIED OPTICS LA English DT Article AB Beam misalignments and bulk fluid velocities can influence the time history and intensity of laser-induced thermal acoustics (LITA) signals. A closed-form analytic expression for LITA signals incorporating these effects is derived, allowing the magnitude of beam misalignment and velocity to he inferred from the signal shape. It is demonstrated how instantaneous, nonintrusive, and remote measurement of sound speed and velocity (Mach number) can be inferred simultaneously from homodyne-detected LITA signals. The effects of different forms of beam misalignment are explored experimentally and compared with theory, with good agreement, allowing the amount of misalignment to be measured li om the LITA signal. This capability could be used to correct experimental misalignments and account for the effects of misalignment in other LITA measurements. It is shown that small beam misalignments have no influence on the accuracy or repeatability of sound speed measurements with LITA. (C) 1999 Optical Society of America OCIS codes: 000.2170, 050.2770, 120.6780, 120.7280, 190.4380. C1 CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Schlamp, S (reprint author), CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. EM stefan@galcit.caltech.edu RI Schlamp, Stefan/A-9143-2008 OI Schlamp, Stefan/0000-0002-9933-3096 NR 10 TC 13 Z9 13 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 1999 VL 38 IS 27 BP 5724 EP 5733 DI 10.1364/AO.38.005724 PG 10 WC Optics SC Optics GA 239PX UT WOS:000082779600005 PM 18324083 ER PT J AU Smith, CA Lee, HWH Leppert, VJ Risbud, SH AF Smith, CA Lee, HWH Leppert, VJ Risbud, SH TI Ultraviolet-blue emission and electron-hole states in ZnSe quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article ID LASER-DIODES; CDSE; PSEUDOPOTENTIALS; CRYSTALLITES; CLUSTERS; WELLS AB We observed the quantum-confined band edge emission from ZnSe quantum dots and the size dependence of the energy states, spin-orbit interaction, and Stokes shift. The band edge emission occurs in the ultraviolet blue. The energy gap=E-g+C/d(n) where d is the diameter and n is 1.19 +/- 0.13 and 1.21 +/- 0.13 for the first and second electron-hole transitions, respectively. The separation between these transitions approaches the bulk spin-orbit splitting, while the Stokes shift decreases with particle size. Effective mass theories cannot explain these results. Trap emission is observed in some samples in the green and red, resulting from Se-related traps. (C) 1999 American Institute of Physics. [S0003-6951(99)03437-3]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. RP Lee, HWH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 23 TC 73 Z9 77 U1 1 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 20 PY 1999 VL 75 IS 12 BP 1688 EP 1690 DI 10.1063/1.124834 PG 3 WC Physics, Applied SC Physics GA 235NE UT WOS:000082547100012 ER PT J AU Haerle, R Galli, G Baldereschi, A AF Haerle, R Galli, G Baldereschi, A TI Structural models of amorphous carbon surfaces SO APPLIED PHYSICS LETTERS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; DIAMOND-LIKE CARBON; ELECTRONIC-PROPERTIES; NEUTRON-SCATTERING; MOLECULAR-DYNAMICS; FILMS; SUBPLANTATION; ENERGY; GROWTH AB Using tight-binding molecular dynamics, we have constructed structural models of amorphous carbon surfaces, by imposing tensile strain on computer generated networks containing 512 carbon atoms until fracture is produced and two surfaces are formed. Different tensile strains are applied along different directions, in order to mimic the effect of preparation conditions. The surfaces generated with different strains from networks with a given bulk atomic density, exhibit similar structures and formation energies differ by a few 0.01 eV/Angstrom(2). Surface roughness increases with the amount of the graphitic component in the bulk sample. The calculated surface thicknesses are consistent with recent experimental data. (C) 1999 American Institute of Physics. [S0003-6951(99)03038-7]. C1 Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Haerle, R (reprint author), Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. NR 19 TC 21 Z9 21 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 20 PY 1999 VL 75 IS 12 BP 1718 EP 1720 DI 10.1063/1.124836 PG 3 WC Physics, Applied SC Physics GA 235NE UT WOS:000082547100022 ER PT J AU Freudling, W Zehavi, I da Costa, LN Dekel, A Eldar, A Giovanelli, R Haynes, MP Salzer, JJ Wegner, G Zaroubi, S AF Freudling, W Zehavi, I da Costa, LN Dekel, A Eldar, A Giovanelli, R Haynes, MP Salzer, JJ Wegner, G Zaroubi, S TI Large-scale power spectrum and cosmological parameters from SFI peculiar velocities SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; cosmology : theory; dark matter; galaxies : clusters : general; galaxies : distances and redshifts; large-scale structure of universe ID TULLY-FISHER RELATION; SPIRAL GALAXIES; DENSITY FIELDS; HUBBLE FLOW; JY SURVEY; EVOLUTION; IRAS; FLUCTUATIONS; CLUSTERS; SAMPLES AB We estimate the power spectrum of mass density fluctuations from peculiar velocities of galaxies by applying an improved maximum likelihood technique to the new all-sky SFI catalog. Parametric models are used for the power spectrum and the errors, and the free parameters are determined by assuming Gaussian velocity fields and errors and maximizing the probability of the data given the model. It has been applied to generalized cold dark matter (CDM) models with and without COBE normalization. The method has been carefully tested using artificial SFI catalogs. The most likely distance errors are found to be similar to the original error estimates in the SFI data. The general result that is not very sensitive to the prior model used is a relatively high amplitude of the power spectrum. For example, at k = 0.1 h Mpc(-1) we find P(k)Omega(1.2) = (4.4 +/- 1.7) x 10(3)(h(-1) Mpc)(3). An integral over the power spectrum yields sigma(8)Omega(0.6) = 0.82 +/- 0.12. Model-dependent constraints on the cosmological parameters are obtained for families of CDM models. For example, for COBE-normalized ACDM models (scalar fluctuations only), the maximum likelihood result can be approximated by Omega n(2)h(60)(1.3) = 0.58 +/- 0.11. The formal random errors quoted correspond to the 90% confidence level. The total uncertainty, including systematic errors associated with nonlinear effects, may be larger by a factor of similar to 2. These results are in agreement with an application of a similar method to other data (Mark III). C1 European So Observ, Space Telescope European Coordinating Facil, D-85748 Garching, Germany. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Fermi Natl Accelerator Lab, NASA, Fermilab Astrophys Grp, Batavia, IL 60510 USA. Observ Nacl, Rio De Janeiro, Brazil. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14953 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Ithaca, NY 14953 USA. Wesleyan Univ, Dept Astron, Middletown, CT 06457 USA. Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. Max Planck Inst Astrophys, D-85740 Garching, Germany. RP Freudling, W (reprint author), European So Observ, Space Telescope European Coordinating Facil, Karl Schwarzschild Str 2, D-85748 Garching, Germany. NR 52 TC 44 Z9 44 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 1999 VL 523 IS 1 BP 1 EP 15 DI 10.1086/307707 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 237TZ UT WOS:000082673300001 ER PT J AU Wood, BD Whitaker, S AF Wood, BD Whitaker, S TI Cellular growth in biofilms SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE biofilms; cell growth; volume averaging; structured models ID ESCHERICHIA-COLI; POROUS-MEDIA; STRUCTURED MODEL; SATURATED SOILS; ION-TRANSPORT; SINGLE CELL; DIFFUSION; PERMEABILITY; SYSTEMS AB In this paper we develop a macroscopic evolutionary equation for the growth of the cellular phase starting from a microscopic description of mass transport: and a simple structured model for product formation. The methods of continuum mechanics and volume averaging are used to develop the macroscopic representation by carefully considering the fluxes of chemical species that pertain to cell growth. The concept of structured models is extended to include the transport of reacting chemical species at: the microscopic scale. The resulting macroscopic growth model is similar in form to previously published models for the transport of a single substrate and electron donor and for the production of cellular mass and exopolymer. The method of volume averaging indicates under what conditions the developed growth model is valid and provides an explicit connection between the relevant microscopic model parameters and their corresponding macroscopic counterparts. (C) 1999 John Wiley & Sons, Inc. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. RP Wood, BD (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Wood, Brian/K-4025-2012; Wood, Brian/J-8362-2013 OI Wood, Brian/0000-0003-3152-7852; Wood, Brian/0000-0003-3152-7852 NR 44 TC 31 Z9 33 U1 1 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD SEP 20 PY 1999 VL 64 IS 6 BP 656 EP 670 DI 10.1002/(SICI)1097-0290(19990920)64:6<656::AID-BIT4>3.0.CO;2-N PG 15 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 226JH UT WOS:000082016500004 PM 10417214 ER PT J AU Gerasimov, OV Lymar, SV AF Gerasimov, OV Lymar, SV TI The yield of hydroxyl radical from the decomposition of peroxynitrous acid SO INORGANIC CHEMISTRY LA English DT Article ID ELECTRON-TRANSFER-REACTIONS; NITRIC-OXIDE; HYDROGEN-PEROXIDE; AQUEOUS-SOLUTION; BIOLOGICAL-ACTIVITY; INDIRECT OXIDATIONS; PULSE-RADIOLYSIS; CARBON-DIOXIDE; SPIN TRAP; SUPEROXIDE AB Mechanistic predictions, based upon the assumption that free (OH)-O-. and (NO2)-N-. radicals are formed as intermediates during the ONOOH decay, were tested using inorganic radical scavengers. Both the rates and the yields of Fe(CN)(6)(4-) and IrCl63- oxidation by ONOOH were independent of their concentrations in submillimolar range. A 55 +/- 7% Fe(CN)(6)(3-) yield and 25 +/- 3% IrCl62- were measured at pH 5.7, 22 degrees C. A yields ratio close to 2 is expected, because, of the two radicals produced, only (OH)-O-. can rapidly oxidize IrCl63-. The competition kinetic studies demonstrated that the relative reactivities of the oxidizing intermediate generated by ONOOH toward IrCl63- and NO2- were identical with the reactivities of the "authentic" (OH)-O-. radical generated by pulse radiolysis. It is concluded that ONOOH decomposes via its peroxo bond homolysis producing a pair of discrete (OH)-O-. and . NO2 radicals with 28 +/- 4% yield. A bimolecular reaction between ONOOH and Fe(CN)64- with the rate constant (8.2 +/- 0.4) M-1 s(-1) significantly increases both oxidation yield and rate at high [Fe(CN)(6)(4-)]. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM lymar@bnl.gov NR 52 TC 79 Z9 82 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD SEP 20 PY 1999 VL 38 IS 19 BP 4317 EP 4321 DI 10.1021/ic990384y PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 238MG UT WOS:000082713600022 ER PT J AU Fedkiw, RP Aslam, T Xu, SJ AF Fedkiw, RP Aslam, T Xu, SJ TI The ghost fluid method for deflagration and detonation discontinuities SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID HYPERBOLIC SYSTEMS; TRACKING METHOD; FLOW; CURVATURE; SCHEMES; FRONTS AB The level set method for multiphase compressible flows is simple to implement, especially in the presence of topological changes. However, this method was shown to suffer from large spurious oscillations. A new Ghost Fluid Method (GFM) was developed to remove these spurious oscillations by minimizing the numerical smearing in the entropy field with the help of an Isobaric Fix technique. The GFM was designed for traditional contact discontinuities where the interface moves with the fluid velocity only. In this paper, the GFM is extended to treat multimaterial interfaces where the interface velocity includes a regression rate due to the presence of chemical reactions converting one material into another. Specifically, interface models for deflagration and detonation discontinuities are considered. The resulting numerical method is robust and easy to implement. (C) 1999 Academic Press. C1 Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Urbana, IL 61807 USA. RP Fedkiw, RP (reprint author), Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA. NR 30 TC 92 Z9 104 U1 0 U2 11 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 20 PY 1999 VL 154 IS 2 BP 393 EP 427 DI 10.1006/jcph.1999.6320 PG 35 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 238KE UT WOS:000082708800007 ER PT J AU Knio, OM Najm, HN Wyckoff, PS AF Knio, OM Najm, HN Wyckoff, PS TI A semi-implicit numerical scheme for reacting flow II. Stiff, operator-split formulation SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE implicit; stiff; operator splitting; chemistry; reacting; flow; projection ID RUNGE-KUTTA METHODS; PARTIAL-DIFFERENTIAL EQUATIONS; NAVIER-STOKES EQUATIONS; ATMOSPHERIC CHEMISTRY; CHEMICAL-KINETICS; TURBULENT COMBUSTION; PROJECTION METHOD; EXPLICIT METHODS; PREMIXED FLAME; ODE SOLVER AB A stiff,(1) operator-split projection scheme is constructed for the simulation of unsteady two-dimensional reacting flow with detailed kinetics. The scheme is based on the compressible conservation equations for an ideal gas mixture in the zero-Mach- number limit. The equations of motion are spatially discretized using second-order centered differences and are advanced in time using a new stiff predictor-corrector approach. The new scheme is a modified version of the additive, stiff scheme introduced in a previous effort by H. N. Najm, P. S. Wyckoff, and O. M. Knio (1998, J. Comput. Phys. 143, 381). The predictor updates the scalar fields using a Strang-type operator-split integration step which combines several explicit diffusion sub-steps with a single stiff step for the reaction terms, such that the global time step may significantly exceed the critical diffusion stability limit. Convection terms are explicitly handled using a second-order multi-step scheme. The velocity field is advanced using a projection scheme which consists of a partial convection-diffusion update followed by a pressure correction step. A split approach is also adopted for the convection-diffusion step in the momentum update. This splitting combines an explicit treatment of the convective terms at the global time step with several explicit fractional steps for diffusion. Finally, a corrector step is implemented in order to couple the evolution of the density and velocity fields and to stabilize the computations. The corrector acts only on the convective terms and the pressure field, while the predicted updates due to diffusion and reaction are left unchanged. The correction of the scalar fields is implemented using a single-step non-split, non-stiff, second-order rime integration. A similar procedure is used for the velocity field, which is followed by a pressure projection step. The performance and behavior of the operator-split scheme are first analyzed based on tests for a nonlinear reaction-diffusion equation in one space dimension, followed by computations with a detailed C1C2 methane-air mechanism in one and two dimensions. The tests are used to verify that the scheme is effectively second order in time, and to suggest guidelines for selecting integration parameters, including the number of fractional diffusion steps and tolerance levels in the stiff integration. For two-dimensional simulations with the present reaction mechanism, flame conditions, and resolution parameters, speedup factors of about 5 are achieved over the previous additive scheme, and about 25 over the original explicit scheme. (C) 1999 Academic Press. C1 Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Knio, OM (reprint author), Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. EM knio@jhu.edu; hnnajm@ca.sandia.gov RI Knio, Omar/A-3318-2010 NR 88 TC 89 Z9 90 U1 2 U2 11 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 20 PY 1999 VL 154 IS 2 BP 428 EP 467 DI 10.1006/jcph.1999.6322 PG 40 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 238KE UT WOS:000082708800008 ER PT J AU Doskey, PV Gao, WG AF Doskey, PV Gao, WG TI Vertical mixing and chemistry of isoprene in the atmospheric boundary layer: Aircraft-based measurements and numerical modeling SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ORGANIC-COMPOUND EMISSIONS; REACTIVE TRACE GASES; METHYL VINYL KETONE; SATELLITE-OBSERVATIONS; OXIDATION-PRODUCTS; NORTH-ATLANTIC; UNITED-STATES; FLUXES; ENCLOSURE; SURFACE AB Vertical profiles of isoprene, methanol, and ozone (O-3) concentrations were measured between the middle and upper atmospheric boundary layer (ABL) from a research aircraft and were numerically simulated for the ABL and a deciduous forest canopy with a one-dimensional model coupling turbulence diffusion and atmospheric chemistry. Isoprene emissions from the deciduous forest canopy were estimated by coupling an existing biogenic emission algorithm with estimates of canopy leaf density inferred from satellite remote sensing observations. Numerical simulations predicted low isoprene concentrations in the middle and upper ABL; however, the agreement between the simulations and the measured values was poor for two of the three profiles, indicating that a three-dimensional transport model might be necessary in future simulations. Chemical oxidation of isoprene by O-3 and hydroxyl radical (OH), particularly in the middle and upper ABL, tends to reduce the isoprene concentrations and influences the vertical fluxes in that layer; however, chemical reactions have little effect on fluxes of isoprene near the emission source, where turbulent mixing is much faster than chemical reactions and where the emission process controls the vertical flux. The isoprene flux decreases rapidly with increasing height, with little isoprene escaping from the ABL. Vertical profiles of methanol concentrations were simulated with the biogenic emission algorithm used for isoprene; these vertical profiles were similar to the measured values for the well-mixed ABL but were much lower than the measured concentrations in the lower layers of the growing ABL because of weaker calculated mixing in the upper ABL during the morning. The results of this investigation indicate that chemical oxidation of isoprene is rapid enough to allow O-3 and other oxidants to accumulate in the ABL on a regional scale if sufficient levels of nitrogen oxides are present; however, methanol is much more stable, and biogenic emissions of this compound have the potential to form O-3 and other oxidants in areas distant from the emission source. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Doskey, PV (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave,Bldg 203,Room J183, Argonne, IL 60439 USA. EM pvdoskey@anl.gov; wgao345620@aol.com NR 31 TC 11 Z9 11 U1 1 U2 6 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 SEP 20 PY 1999 VL 104 IS D17 BP 21263 EP 21274 DI 10.1029/1999JD900018 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200004 ER PT J AU Onasch, TB Siefert, RL Brooks, SD Prenni, AJ Murray, B Wilson, MA Tolbert, MA AF Onasch, TB Siefert, RL Brooks, SD Prenni, AJ Murray, B Wilson, MA Tolbert, MA TI Infrared spectroscopic study of the deliquescence and efflorescence of ammonium sulfate aerosol as a function of temperature SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CIRRUS CLOUD NUCLEATION; TROPOSPHERIC AEROSOLS; PHASE-TRANSFORMATION; AQUEOUS (NH4)(2)SO4; RELATIVE-HUMIDITY; SOLUTION DROPLETS; ICE NUCLEATION; MODEL; METASTABILITY; N2O5 AB The deliquescence and efflorescence phase transitions of ammonium sulfate aerosols have been studied as a function of relative humidity (RH) over the temperature range from 234 K to 295 K. Polydisperse submicrometer ammonium sulfate particles produced by atomization were monitored in a temperature-controlled flow tube system using Fourier transform infrared spectroscopy. The relative humidity in the aerosol flow was controlled using a sulfuric acid bath conditioner and the addition of a known flow of dry nitrogen. The relative humidity was measured using a dew point hygrometer and infrared absorption features. The deliquescence transition was observed to be nearly independent of temperature, changing from 80% RH at 294.8 K to 82% RH at 258.0 K near the ice saturation line, in good agreement with previous results. The relative humidity at the efflorescence transition also increased slightly (32% to 39%) with decreasing temperature (294.8 K to 234.3 K). These results suggest that once a crystalline ammonium sulfate particle deliquesces, the droplet can exist as a metastable solution droplet over a broad region of temperature and water pressures under the conditions in the upper troposphere. The persistence of metastable ammonium sulfate solution droplets may have important implications for cirrus cloud formation and heterogeneous reaction rates in the upper troposphere. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. Univ Colorado, Dept Biochem & Chem, Boulder, CO 80309 USA. RP Onasch, TB (reprint author), Brookhaven Natl Lab, 75 Rutherford Dr, Upton, NY 11973 USA. EM onasch@bnl.gov; siefert@cbl.umces.edu; brookssd@colorado.edu; prenni@colorado.edu; tolbert@spot.colorado.edu RI Murray, Benjamin/C-1219-2010; Prenni, Anthony/A-6820-2011; Brooks, Sarah/H-1176-2012 OI Murray, Benjamin/0000-0002-8198-8131; NR 38 TC 101 Z9 101 U1 3 U2 40 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 SEP 20 PY 1999 VL 104 IS D17 BP 21317 EP 21326 DI 10.1029/1999JD900384 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200008 ER PT J AU Kotamarthi, VR Wuebbles, DJ Reck, RA AF Kotamarthi, VR Wuebbles, DJ Reck, RA TI Effects of nonmethane hydrocarbons on lower stratospheric and upper tropospheric chemical climatology in a two-dimensional zonal average model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATMOSPHERIC CHEMISTRY; GLOBAL TROPOSPHERE; OZONE PRODUCTION; TRANSPORT MODEL; PHOTOCHEMISTRY; EMISSIONS; TRACERS; NOX; AEROSOLS; ACETONE AB The effect on the modeled chemical climatology of the upper troposphere and lower stratosphere of including a limited set of nonmethane hydrocarbons in a two-dimensional (2-D) zonal average model is presented. Recent measurements of nitrogenated and oxygenated hydrocarbons in the upper troposphere and lower stratosphere have revealed the possibility of significant perturbation of this region. A zonally averaged 2-D chemical transport model enhanced to represent tropospheric processes was used to explore the extent of this perturbation on global and regional spatial scales and on seasonal and annual average timescales. Acetone was shown to cause a significant increase in the HOx budgets of the upper troposphere in the midlatitude Northern Hemisphere during the winter and early spring months, with acetone photolysis providing the most significant source of HOx radicals. The tropical upper troposphere has a uniform increase in HOx of up to 20% throughout the year because of acetone photolysis. Including the hydrocarbons caused a net increase in ozone of 5 ppbv in the lower and middle troposphere and 5-10 ppbv in the upper troposphere for global and annual averages. The effect of including the hydrocarbons on the calculated model ozone response for the case of doubled surface mixing ratios of atmospheric CH4 is also discussed. It is shown that including hydrocarbons in the model has a significant effect on the modeled ozone response to the methane increase. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Univ Calif Davis, Natl Inst Global Environm Change, Davis, CA 95616 USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. RP Kotamarthi, VR (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. EM vrkotamarthi@anl.gov OI Kotamarthi, Veerabhadra Rao/0000-0002-2612-7590 NR 53 TC 8 Z9 8 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 SEP 20 PY 1999 VL 104 IS D17 BP 21537 EP 21547 DI 10.1029/1999JD900334 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200022 ER PT J AU Weber, RJ McMurry, PH Bates, TS Clarke, AD Covert, DS Brechtel, FJ Kok, GL AF Weber, RJ McMurry, PH Bates, TS Clarke, AD Covert, DS Brechtel, FJ Kok, GL TI Intercomparison of airborne and surface-based measurements of condensation nuclei in the remote marine troposphere during ACE 1 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PASSING EFFICIENCY; AEROSOL; AIRCRAFT; DIAMETER; FLOW AB Intercomparisons of aerosol particle number concentrations measured with various condensation particle counters (CPCs) during the first Aerosol Characterization Experiment (ACE 1) are made to assess the accuracy of the airborne measurements. When no ambient 3-10 nm diameter particles (nanoparticles) were present, median concentrations' from four CPCs on the National Center for Atmospheric Research (NCAR) C-130 aircraft agreed to within similar to 6% and were highly correlated (r > 0.9). These instruments sampled from several different inlets and used various arrangements (e.g., tubing size and length, flow rates) to transport sampled air to the detectors. When the ambient aerosol contained significant numbers of nanoparticles, agreement between the CPCs deteriorated, Likely from differences in nanoparticle transmission and detection efficiencies. During these periods, average total number concentrations measured by two ultrafine CPCs varied on average by 60% with a correlation coefficient of 0.85. Intercomparisons of airborne and surface-based measurements were made during low-altitude flybys of surface measurement sites. During flybys, few nanoparticles were detected, and measured total condensation nuclei (CN) concentrations differed by roughly +5 to -20% (CNsurface/CNairborne-1) suggesting that the airborne measurements of fine aerosols agreed with ambient surface values to within 20%. Overall, we found that ambient fine particles (similar to 20-100 nm diameter) are fairly insensitive to airborne sampling techniques and thus are likely to be measured accurately. Sampling losses of smaller particles, however, may lead to a significant undermeasurement of ambient CN concentrations in rare instances when the number spectra are dominated by the smallest particles. This intercomparison involves measurements made in regions absent of liquid water to avoid artifact particles produced by fragmenting water droplets. C1 Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. Univ Minnesota, Dept Mech Engn, Particle Technol Lab, Minneapolis, MN 55455 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Natl Ctr Atmospher Res, Res Aviat Facil, Boulder, CO 80307 USA. RP Weber, RJ (reprint author), Georgia Inst Technol, Georgia Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. EM rweber@eas.gatech.edu RI McMurry, Peter/A-8245-2008; Bates, Timothy/L-6080-2016 OI McMurry, Peter/0000-0003-1609-5131; NR 20 TC 9 Z9 9 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1999 VL 104 IS D17 BP 21673 EP 21683 DI 10.1029/1998JD100103 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200034 ER PT J AU Gustin, MS Lindberg, SE Allan, MA AF Gustin, MS Lindberg, SE Allan, MA TI Special Section: Constraining mercury emissions from naturally enriched surfaces: Assessment of methods and controlling parameters (Mercury Flux) - Preface SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID ELEMENTAL MERCURY; TRACE-METALS; DEPOSITION; SOILS; CONTAMINATION; SCANDINAVIA; EXCHANGE; NEVADA; TESTS; RATES C1 Univ Nevada, Dept Environm & Resource Sci, Reno, NV 89557 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Elect Power Res Inst, Palo Alto, CA USA. RP Gustin, MS (reprint author), Univ Nevada, Dept Environm & Resource Sci, Reno, NV 89557 USA. NR 23 TC 7 Z9 8 U1 2 U2 3 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 SEP 20 PY 1999 VL 104 IS D17 BP 21829 EP 21830 DI 10.1029/1999JD900396 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200045 ER PT J AU Gustin, MS Lindberg, S Marsik, F Casimir, A Ebinghaus, R Edwards, G Hubble-Fitzgerald, C Kemp, R Kock, H Leonard, T London, J Majewski, M Montecinos, C Owens, J Pilote, M Poissant, L Rasmussen, P Schaedlich, F Schneeberger, D Schroeder, W Sommar, J Turner, R Vette, A Wallschlaeger, D Xiao, Z Zhang, H AF Gustin, MS Lindberg, S Marsik, F Casimir, A Ebinghaus, R Edwards, G Hubble-Fitzgerald, C Kemp, R Kock, H Leonard, T London, J Majewski, M Montecinos, C Owens, J Pilote, M Poissant, L Rasmussen, P Schaedlich, F Schneeberger, D Schroeder, W Sommar, J Turner, R Vette, A Wallschlaeger, D Xiao, Z Zhang, H TI Nevada STORMS project: Measurement of mercury emissions from naturally enriched surfaces SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MODIFIED BOWEN-RATIO; EDDY-CORRELATION; DRY DEPOSITION; ELEMENTAL MERCURY; VOLATILE MERCURY; DECIDUOUS FOREST; GASEOUS MERCURY; FLUX CHAMBER; TRACE-METALS; SHORT-TERM AB Diffuse anthropogenic and naturally mercury-enriched areas represent long-lived sources of elemental mercury to the atmosphere. The Nevada Study and Tests of the Release of Mercury From Soils (STORMS) project focused on the measurement of mercury emissions from a naturally enriched area. During the project, concurrent measurements of mercury fluxes from naturally mercury-enriched substrate were made September 1-4, 1997, using four micrometeorological methods and seven field flux chambers. Ambient air mercury concentrations ranged from 2 to nearly 200 ng m(-3) indicating that the field site is a source of atmospheric mercury. The mean daytime mercury fluxes,during conditions of no precipitation, measured with field chambers were 50 to 360 ng m(-2) h(-1) and with the micrometeorological methods were 230 to 600 ng m(-2) h(-1). This wide range in mercury emission rates reflects differences in method experimental designs and local source strengths. Mercury fluxes measured by many field chambers were significantly different (p < 0.05) but linearly correlated. This indicates that field chambers responded similarly to environmental conditions, but differences in experimental design and site heterogeneity had a significant influence on the magnitude of mercury fluxes. Data developed during the :field study demonstrated that field flux chambers are ideal for assessment of the physicochemical processes driving mercury flux and development of an understanding of the magnitude of the influence of individual factors on flux. In general, mean mercury fluxes measured with micrometeorological methods during daytime periods were nearly 3 times higher than mean fluxes measured with field flux chambers. Micrometeorological methods allow for derivation of a representative mercury flux occurring from an unconstrained system and provide an assessment of the actual magnitude and variability of fluxes occurring from an area. C1 Univ Nevada, Dept Environm & Resource Sci, Reno, NV 89557 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Michigan, Sch Publ Hlth, Ann Arbor, MI 48109 USA. Environm Canada, St Laurent, PQ H4M 2N8, Canada. GKSS Forschungszentrum Geesthacht GmbH, Res Ctr, Inst Phys & Chem Anal, D-21502 Geesthacht, Germany. Univ Guelph, Dept Environm Engn, Guelph, ON N1G 2W1, Canada. Frontier Geosci, Seattle, WA 98109 USA. US Geol Survey, Sacramento, CA 94925 USA. Geol Survey Canada, Ottawa, ON K2A 0E8, Canada. Tekran Inc, Toronto, ON M3A 1A3, Canada. Gothenburg Univ, Dept Inorgan Chem, S-41296 Gothenburg, Sweden. RP Gustin, MS (reprint author), Univ Nevada, Dept Environm & Resource Sci, Reno, NV 89557 USA. EM msg@scs.unr.edu RI Vette, Alan/A-7330-2012; Pilote, Martin/G-2581-2016; OI Vette, Alan/0000-0001-6749-1252; Pilote, Martin/0000-0002-6874-5135; Rasmussen, Pat/0000-0001-6748-4255 NR 78 TC 135 Z9 147 U1 7 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1999 VL 104 IS D17 BP 21831 EP 21844 DI 10.1029/1999JD900351 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200046 ER PT J AU Lindberg, SE Zhang, H Gustin, M Vette, A Marsik, F Owens, J Casimir, A Ebinghaus, R Edwards, G Fitzgerald, C Kemp, J Kock, HH London, J Majewski, M Poissant, L Pilote, M Rasmussen, P Schaedlich, F Schneeberger, D Sommar, J Turner, R Wallschlager, D Xiao, Z AF Lindberg, SE Zhang, H Gustin, M Vette, A Marsik, F Owens, J Casimir, A Ebinghaus, R Edwards, G Fitzgerald, C Kemp, J Kock, HH London, J Majewski, M Poissant, L Pilote, M Rasmussen, P Schaedlich, F Schneeberger, D Sommar, J Turner, R Wallschlager, D Xiao, Z TI Increases in mercury emissions from desert soils in response to rainfall and irrigation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VAPOR; EXCHANGE; NEVADA; TESTS; SORPTION; BEHAVIOR; CHAMBER; FORESTS; FLUXES; SITES AB As part of an international Hg flux intercomparison at the Steamboat Springs, Nevada, geothermal area, several dynamic soil flux chambers and micrometeorological gradient systems were operated over desert soils in early September 1997. A series of unanticipated convective rain cells impacted the site with the first rainfall in similar to 90 days, and the initial 4-cm rainfall increased soil moisture from similar to 0.01 to 0.06% (vol/vol). Several chambers were operating prior to the events, and two were deployed over wet soils following rainfall. Rainfall resulted in an immediate and steep rise in ambient air Hg concentrations and soil Hg emissions which persisted for 12-24 hours. Fluxes increased most quickly and to a greater degree over the wettest soils, and the rate of increase was related to chamber design and flushing rate. The flux response was also apparent in the micrometeorological data. In general, soil emissions increased by an order of magnitude following the rain, and reached levels similar to 6 times above those at the same time the previous day. These fluxes were significantly correlated with temperature, radiation, humidity, wind speed, and soil moisture. After drying for similar to 40 hours, selected soil plots were manually irrigated with low-Hg-distilled water. Mercury emissions responded similarly across the three treated sites, uniformly increasing from similar to 60 ng m(-2) h(-1) pretreatment to similar to 650 ng m(-2) h(-1) posttreatment, which was a factor of similar to 6 higher than adjacent control soils. Possible causes of the increases in flux include soil gas displacement, desorption of Hg degrees by water molecules, and desorption of Hg(II) and subsequent reduction in solution. The kinetics of the flux response, combined with local soil and climatic conditions, suggest that Hg emissions were responding primarily to soil moisture and solar radiation. These data have interesting implications for the role of changing regional climates on biogeochemical cycling of Hg. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Lindberg, SE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM sll@ornl.gov RI Vette, Alan/A-7330-2012; Pilote, Martin/G-2581-2016; OI Vette, Alan/0000-0001-6749-1252; Pilote, Martin/0000-0002-6874-5135; Rasmussen, Pat/0000-0001-6748-4255 NR 26 TC 99 Z9 105 U1 0 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1999 VL 104 IS D17 BP 21879 EP 21888 DI 10.1029/1999JD900202 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200050 ER PT J AU Zhang, H Lindberg, SE AF Zhang, H Lindberg, SE TI Processes influencing the emission of mercury from soils: A conceptual model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DISSOLVED GASEOUS MERCURY; ELEMENTAL MERCURY; HUMIC SUBSTANCES; CHLORIDE CONCENTRATION; ATMOSPHERIC MERCURY; AQUEOUS-SOLUTIONS; SURFACE EXCHANGE; NATURAL-WATERS; VAPOR; AIR AB In contrast to recent rapid growth in the field data on mercury flux over soils, our knowledge and understanding of the emission processes and controlling mechanisms still remains limited. Many processes could control emission of mercury from soils. The emission processes may involve both Hg(0) and Hg(II) pools, both homogeneous and heterogeneous distributions and reactions, and both dark and light processes. The physical and chemical controlling processes mainly involve (1) distribution of different mercury species among different soil phases, largely associated with adsorption and desorption of Hg(0) and Hg(II) species, and (2) mercury redox reactions in soils, some of which could be induced by sunlight, especially in the UV. The distribution (sorption versus desorption) of Hg(0) in soils could be the rate-limiting process in the case where Hg(0) is the dominant mercury pool, and the redox reactions could be rate-limiting in the case where Hg(II) is the major pool. Various hypothetical scenarios of Hg(0) and Hg(II) transformation in soils are discussed here. However, the specific processes that actually occur in soils under natural conditions are far from clear and need to be identified and quantified in future research. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Zhang, H (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM 2hz@ornl.gov RI Mason, Robert/A-6829-2011 NR 93 TC 91 Z9 97 U1 3 U2 29 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 SEP 20 PY 1999 VL 104 IS D17 BP 21889 EP 21896 DI 10.1029/1999JD900194 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 238BC UT WOS:000082690200051 ER PT J AU Benmore, CJ Sweeney, S Robinson, RA Egelstaff, PA Suck, JB AF Benmore, CJ Sweeney, S Robinson, RA Egelstaff, PA Suck, JB TI Longitudinal excitations in Mg70Zn30 glass SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID NEUTRON BRILLOUIN-SCATTERING; METALLIC-GLASS; COLLECTIVE EXCITATIONS; DISPERSION AB The Neutron Brillouin Scattering technique has been used to measure longitudinal excitations in a magnesium-zinc glass at momentum transfers, Q, within the first pseudo-Brillouin zone. The measurements were performed at room temperature and at constant momentum transfer, down to Q = 6.2 nm(-1), and an energy transfer of E = 16 meV. The experimental one-phonon spectral functions for the glass have been extracted and compared directly to theoretical predictions. At the first Brillouin zone boundary (Q(P)/2 = 13 nm(-1)) experiment and theory show some agreement, but at lower momentum transfers there is a shift of several meV in the peak position of the neutron intensity, towards lower energies. Evidence for the two observed modes is presented and the possibility of mode mixing is discussed. In conclusion, the need for new simulations is highlighted. C1 Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Rutherford Appleton Lab, ISIS Facil, Chilton OX11 OHR, Oxon, England. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. TU Chemnitz, Inst Phys Mat Res & Lipids, D-09107 Chemnitz, Germany. RP Benmore, CJ (reprint author), Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. OI Benmore, Chris/0000-0001-7007-7749 NR 13 TC 9 Z9 9 U1 1 U2 5 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 SEP 20 PY 1999 VL 11 IS 37 BP 7079 EP 7088 DI 10.1088/0953-8984/11/37/305 PG 10 WC Physics, Condensed Matter SC Physics GA 239YU UT WOS:000082799000007 ER PT J AU Vitkalov, SA Bowers, CR Simmons, JA Reno, JL AF Vitkalov, SA Bowers, CR Simmons, JA Reno, JL TI Nuclear spin-orientation dependence of magnetoconductance: a new method for measuring the spin of charged excitations in the quantum Hall effect SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID 2-DIMENSIONAL ELECTRON-GAS; SKYRMIONS; GAAS; INTEGER; NU=1 AB A new method for measuring the spin of the electrically charged ground-state excitations in the quantum Hall effect is proposed and demonstrated for the first time for GaAs/AlGaAs multiquantum wells. The method is based on the nuclear spin-orientation dependence of the two-dimensional direct-current conductivity in the quantum Hall regime due to the nuclear hyperfine interaction. We use this method to determine the spin of the electrically charged excitations of the ground state at filling factor nu = 1. C1 Univ Florida, Dept Chem, Gainesville, FL 32611 USA. Univ Florida, Natl High Magnet Field Lab, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bowers, CR (reprint author), Univ Florida, Dept Chem, Gainesville, FL 32611 USA. RI Schaff, William/B-5839-2009 NR 17 TC 5 Z9 5 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 SEP 20 PY 1999 VL 11 IS 37 BP L407 EP L414 DI 10.1088/0953-8984/11/37/101 PG 8 WC Physics, Condensed Matter SC Physics GA 239YU UT WOS:000082799000001 ER PT J AU Wong-Ng, W Melamud, M Bennett, LH Watson, RE AF Wong-Ng, W Melamud, M Bennett, LH Watson, RE TI Local environments of three forms of Ba2YCu3O6+x SO PHYSICA C LA English DT Article DE Wigner-Seitz cells; bonding; superconductor ID HARD MAGNETS; SUPERCONDUCTOR; TC; YBA2CU3O7-DELTA; DISCLINATIONS; ANISOTROPIES; PRESSURE; PACKING; PHASES AB The Wigner-Seitz local atomic cell construction procedure, provides a topological means for comparing series of related structures in terms of the number and type of nearest neighbors. We used this construction to further our understanding of the chemical bonding environment (and hence, the superconducting properties) in three structurally related materials, Ba2YCu3O6+x (x = 1, 1/2, and 0). These are high-T-c superconductors of T-c approximate to 92 K, 56 K, and a nonsuperconductor, respectively. The local environment around Y is found to be similar in all three compounds, and the topology around Ba is generally similar to that in the ideal perovskite. The Cu sites in the Cu-O plane in all three materials show similar anisotropic bonding behavior. Significant results are: (i) that Ba contributes to the bonding with Cu sites, and (ii) the most noticeable difference in the local environment in these compounds is around the Cu sites in the Cu-O "chains". We propose a modified charge-transfer model, involving the Cu-O "chains", "planes" and Ba as an electronic unit, to correlate structure with the observed superconducting properties. The bonding behavior of these oxides also appears to be different from the conventional metal alloy superconductors. (C) 1999 Elsevier Science B.V, All rights reserved. C1 US Dept Commerce, Mat Sci & Engn Lab, Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. RP Wong-Ng, W (reprint author), US Dept Commerce, Mat Sci & Engn Lab, Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 34 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD SEP 20 PY 1999 VL 322 IS 3-4 BP 177 EP 185 DI 10.1016/S0921-4534(99)00399-8 PG 9 WC Physics, Applied SC Physics GA 247FL UT WOS:000083210400006 ER PT J AU Vasiliev, MA Beddo, ME Brown, CN Carey, TA Chang, TH Cooper, WE Gagliardi, CA Garvey, GT Geesaman, DF Hawker, EA He, XC Isenhower, LD Kaplan, DM Kaufman, SB Koetke, DD Lee, WM Leitch, MJ McGaughey, PL Moss, JM Mueller, BA Papavassiliou, V Peng, JC Petitt, G Reimer, PE Sadler, ME Sondheim, WE Stankus, PW Towell, RS Tribble, RE Webb, JC Willis, JL Young, GR AF Vasiliev, MA Beddo, ME Brown, CN Carey, TA Chang, TH Cooper, WE Gagliardi, CA Garvey, GT Geesaman, DF Hawker, EA He, XC Isenhower, LD Kaplan, DM Kaufman, SB Koetke, DD Lee, WM Leitch, MJ McGaughey, PL Moss, JM Mueller, BA Papavassiliou, V Peng, JC Petitt, G Reimer, PE Sadler, ME Sondheim, WE Stankus, PW Towell, RS Tribble, RE Webb, JC Willis, JL Young, GR CA FNAL E866 NuSea Collaboration TI Parton energy loss limits and shadowing in Drell-Yan dimuon production SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEPENDENCE; NUCLEI; DISTRIBUTIONS; COLLISIONS AB A precise measurement of the ratios of the Drell-Yan cross section per nucleon for an 800 GeV/c proton beam incident on Be, Fe, and W targets is reported. The behavior of the Drell-Yan ratios at small target-parton momentum Fraction is well described by an existing fit to the shadowing observed in deep-inelastic scattering. The cross-section ratios as a function of the incident-parton momentum fraction set tight limits on the energy loss of quarks passing through a cold nucleus. C1 Texas A&M Univ, College Stn, TX 77843 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. New Mexico State Univ, Las Cruces, NM 88003 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. IIT, Chicago, IL 60616 USA. Georgia State Univ, Atlanta, GA 30303 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Abilene Christian Univ, Abilene, TX 79699 USA. Valparaiso Univ, Valparaiso, IN 46383 USA. RP Vasiliev, MA (reprint author), Texas A&M Univ, College Stn, TX 77843 USA. RI Reimer, Paul/E-2223-2013 NR 20 TC 106 Z9 109 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 SEP 20 PY 1999 VL 83 IS 12 BP 2304 EP 2307 DI 10.1103/PhysRevLett.83.2304 PG 4 WC Physics, Multidisciplinary SC Physics GA 237MX UT WOS:000082661100006 ER PT J AU Liliental-Weber, Z Benamara, M Washburn, J Grzegory, I Porowski, S AF Liliental-Weber, Z Benamara, M Washburn, J Grzegory, I Porowski, S TI Spontaneous ordering in bulk GaN : Mg samples SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALUMINUM NITRIDE; OXYGEN; POLYTYPOIDS; PRESSURE; CRYSTALS AB Transmission electron microscopy evidence of spontaneous ordering in Mg-doped, bulk GaN crystals grown by a high pressure, high temperature process is reported for the first time. The ordering consists of ME-rich planar defects formed on basal planes separated by 10 nm and occurs only for growth with (000 (1) over bar) N polarity. The ordering leads to the formation of satellite diffraction spots dividing the (0001) reciprocal lattice distance into 20 parts. This "microsuperlattice'' can be described as polytypoids comprised of planar defects with some characteristics of inversion domain boundaries. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Polish Acad Sci, High Pressure Res Ctr Unipress, Warsaw, Poland. RP Liliental-Weber, Z (reprint author), Lawrence Berkeley Lab, M-S 62-203, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 18 TC 47 Z9 47 U1 5 U2 18 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 SEP 20 PY 1999 VL 83 IS 12 BP 2370 EP 2373 DI 10.1103/PhysRevLett.83.2370 PG 4 WC Physics, Multidisciplinary SC Physics GA 237MX UT WOS:000082661100023 ER PT J AU Maslov, S Tang, C Zhang, YC AF Maslov, S Tang, C Zhang, YC TI 1/f noise in Bak-Tang-Wiesenfeld models on narrow stripes SO PHYSICAL REVIEW LETTERS LA English DT Article ID SELF-ORGANIZED CRITICALITY; DIFFUSION AB We report our findings of a 1/f power spectrum for the total amount of sand in directed and undirected Bak-Tang-Wiesenfeld models confined to narrow stripes and driven locally. The underlying mechanism for the 1/f noise in these systems is an exponentially long configuration memory giving rise to a very broad distribution of time scales. Both models are solved analytically with the help of an operator algebra to explicitly show the appearance of the long configuration memory. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NEC Res Inst, Princeton, NJ 08540 USA. Univ Fribourg, Inst Phys Theor, CH-1700 Fribourg, Switzerland. RP Maslov, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 15 TC 24 Z9 24 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 SEP 20 PY 1999 VL 83 IS 12 BP 2449 EP 2452 DI 10.1103/PhysRevLett.83.2449 PG 4 WC Physics, Multidisciplinary SC Physics GA 237MX UT WOS:000082661100043 ER PT J AU Hoffman, CM AF Hoffman, CM TI Comment on "Correlation between compact radio quasars and ultrahigh energy cosmic rays" SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Hoffman, CM (reprint author), Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. NR 10 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 20 PY 1999 VL 83 IS 12 BP 2471 EP 2471 DI 10.1103/PhysRevLett.83.2471 PG 1 WC Physics, Multidisciplinary SC Physics GA 237MX UT WOS:000082661100050 ER PT J AU Buttler, WT Hughes, RJ Kwiat, PG Lamoreaux, SK Morgan, GL Nordholt, JE Peterson, CG AF Buttler, WT Hughes, RJ Kwiat, PG Lamoreaux, SK Morgan, GL Nordholt, JE Peterson, CG TI Comment on "Practical free-space quantum key distribution over 1 km" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYPTOGRAPHY C1 Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Buttler, WT (reprint author), Univ Calif Los Alamos Natl Lab, Div Phys, MS H803, Los Alamos, NM 87545 USA. NR 5 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 20 PY 1999 VL 83 IS 12 BP 2477 EP 2477 DI 10.1103/PhysRevLett.83.2477 PG 1 WC Physics, Multidisciplinary SC Physics GA 237MX UT WOS:000082661100056 ER PT J AU Chambers, SA Yi, SI AF Chambers, SA Yi, SI TI Fe termination for alpha-Fe2O3(0001) as grown by oxygen-plasma-assisted molecular beam epitaxy SO SURFACE SCIENCE LA English DT Letter DE iron oxide; low index single crystal surfaces; photoelectron diffraction; scanning tunneling microscopy; surface structure, morphology, roughness; and topography ID OXIDE; SURFACES; FILMS AB We have investigated the termination of epitaxial alpha-Fe2O3(0001) prepared by oxygen-plasma-assisted molecular beam epitaxy as grown. The sample was stabilized down to near room temperature in the oxygen plasma after growth. The resulting surface is Fe-terminated, despite the highly oxidizing conditions used to end the growth. This result shows that the Fe termination is the most stable surface structure to form, consistent with the predictions of the surface autocompensation model. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Chambers, SA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 14 TC 60 Z9 60 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 20 PY 1999 VL 439 IS 1-3 BP L785 EP L791 DI 10.1016/S0039-6028(99)00766-9 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 238PJ UT WOS:000082718400003 ER PT J AU Ibrahimi, A Bonen, A Blinn, WD Hajri, T Li, X Zhong, K Cameron, R Abumrad, NA AF Ibrahimi, A Bonen, A Blinn, WD Hajri, T Li, X Zhong, K Cameron, R Abumrad, NA TI Muscle-specific overexpression of FAT/CD36 enhances fatty acid oxidation by contracting muscle, reduces plasma triglycerides and fatty acids, and increases plasma glucose and insulin SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID TRANSGENIC MICE; CD36 DEFICIENCY; GENE-EXPRESSION; OXIDIZED LDL; PPAR-GAMMA; TRANSPORT; PROTEIN; BINDING; ADIPOCYTE; RAT AB Increasing evidence has implicated the membrane protein CD36 (FAT) in binding and transport of long chain fatty acids (FA). To determine the physiological role of CD36, we examined effects of its overexpression in muscle, a tissue that depends on FA for its energy needs and is responsible for clearing a major fraction of circulating FA. Mice with CD36 overexpression in muscle were generated using the promoter of the muscle creatine kinase gene (MCK). Transgenic (MCK-CD36) mice had a slightly lower body weight than control litter mates. This reflected a leaner body mass with less overall adipose tissue, as evidenced by magnetic resonance spectroscopy. Soleus muscles from transgenic animals exhibited a greatly enhanced ability to oxidize fatty acids in response to stimulation/contraction; This increased oxidative ability was not associated with significant alterations in histological appearance of muscle fibers. Transgenic mice had lower blood levels of triglycerides and fatty acids and a reduced triglyceride content of very low density lipoproteins. Blood cholesterol levels were slightly lower, but no significant decrease in the cholesterol content of major lipoprotein fractions was measured. Blood glucose was significantly increased, while insulin levels were similar in the fed state and higher in the fasted state. However, glucose tolerance curves, determined at 20 weeks of age, were similar in control and transgenic mice. In summary, the study documented, in vivo, the role of CD36 to facilitate cellular FA uptake. It also illustrated importance of the uptake process in muscle to overall FA metabolism and glucose utilization. C1 SUNY Stony Brook, Dept Physiol & Biophys, Stony Brook, NY 11794 USA. Univ Waterloo, Dept Kinesiol, Waterloo, ON N2L 3G1, Canada. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Abumrad, NA (reprint author), SUNY Stony Brook, Dept Physiol & Biophys, Stony Brook, NY 11794 USA. FU NIDDK NIH HHS [DK33301] NR 39 TC 228 Z9 234 U1 1 U2 12 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 17 PY 1999 VL 274 IS 38 BP 26761 EP 26766 DI 10.1074/jbc.274.38.26761 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 235YD UT WOS:000082570700019 PM 10480880 ER PT J AU Doniach, S AF Doniach, S TI NIH study-section scoring SO SCIENCE LA English DT Letter C1 Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Doniach, S (reprint author), Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 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 SEP 17 PY 1999 VL 285 IS 5435 BP 1850 EP 1850 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 237CT UT WOS:000082638300019 PM 10515787 ER PT J AU Shreve, AP Franzen, S Simpson, MC Dyer, RB AF Shreve, AP Franzen, S Simpson, MC Dyer, RB TI Dependence of NO recombination dynamics in horse myoglobin on solution glycerol content SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SITE-SPECIFIC MUTANTS; GEMINATE RECOMBINATION; CARBON-MONOXIDE; HEME-PROTEINS; RELAXATION; PHOTOLYSIS; HEMOGLOBIN; POCKET; CO; PHOTODISSOCIATION AB The recombination dynamics of NO with horse heart myoglobin (Mb) following photolysis with a 570 nm excitation pulse were measured by time-resolved absorption with 250 fs temporal resolution. These measurements were carried out in room-temperature solutions in which the glycerol concentration was varied from 0 to 90% (w/v). The recombination of NO is nonsingle exponential in all cases, but becomes faster as the glycerol concentration is increased. The interpretation of these results is aided by a maximum entropy analysis to determine a distribution of rate processes consistent with the data. This analysis suggests that in buffer there are two dominant rate processes for NO recombination on the subnanosecond time scale, one at approximate to 10 ps and one at approximate to 200 ps. The dominant effect of increasing glycerol content is to increase the amplitude of the fast process, with no corresponding significant change in rate, and to decrease the amplitude of the slow process, but with a corresponding increase in rate. These results are consistent with a photodissociation process in which photolyzed NO partitions immediately between two distinct populations, one of which has a rapid and the other of which has a slower recombination. The rate of the rapid recombination is independent of glycerol concentration, and therefore decoupled from any protein relaxation process influenced by glycerol, while that of the slower recombination increases at higher glycerol concentration. Further, the partitioning between these two populations also depends on glycerol content, with the relative amplitude of the faster recombination process increasing as the glycerol content is increased. Interpretation of these observations in terms of ligand trajectories following photodissociation, and possible connections of these results with both infrared and crystallographic studies of photodissociated MbCO are discussed. C1 Univ Calif Los Alamos Natl Lab, Biosci & Biotechnol Grp, Los Alamos, NM 87545 USA. RP Shreve, AP (reprint author), Univ Calif Los Alamos Natl Lab, Biosci & Biotechnol Grp, CST-4,MS G755, Los Alamos, NM 87545 USA. RI Simpson, Miriam/C-4237-2011; Simpson, M. Cather/C-7326-2011 NR 24 TC 31 Z9 31 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 16 PY 1999 VL 103 IS 37 BP 7969 EP 7975 DI 10.1021/jp991163g PG 7 WC Chemistry, Physical SC Chemistry GA 238JJ UT WOS:000082706900029 ER PT J AU Jordanides, XJ Lang, MJ Song, XY Fleming, GR AF Jordanides, XJ Lang, MJ Song, XY Fleming, GR TI Solvation dynamics in protein environments studied by photon echo spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID RHODOBACTER-SPHAEROIDES; DIELECTRIC-RELAXATION; MOLECULAR-DYNAMICS; ELECTRON-TRANSFER; SOLVENT DYNAMICS; LYSOZYME; WATER; FEMTOSECOND; HYDRATION; MICELLES AB Photon echo spectroscopy is used to study the mechanisms of solvation dynamics in protein environments at room temperature. Ultrafast and additional multi-exponential long time scales are observed in the three-pulse photon echo peak shift data of the fluorescein dye eosin bound to lysozyme in aqueous solution. The dynamics of the solvated lysozyme are characterized with dielectric continuum models that integrate dielectric data for water with that for lysozyme. By comparing our data with previous results for eosin in water [Lang, M. J.; Jordanides, X. J.; Song, X.; Fleming, G. R. J. Chem. Phys. 1999, 110, 5584], we find that the total coupling of the electronic transition frequency of eosin to the nuclear motions of the aqueous lysozyme solution is smaller than in the aqueous solution. On an ultrafast time scale, solvation appears to be dominated by the surrounding water and not by the ultrafast internal motions of lysozyme. However, over long time scales, lysozyme does contribute significantly, either directly through motions of polar side chains or indirectly through reorientation of the water "bound" to the surface of the protein. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Princeton Univ, Dept Mol Biol, Princeton, NJ 08544 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08544 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Fleming, GR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 61 TC 252 Z9 252 U1 1 U2 37 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 16 PY 1999 VL 103 IS 37 BP 7995 EP 8005 DI 10.1021/jp9910993 PG 11 WC Chemistry, Physical SC Chemistry GA 238JJ UT WOS:000082706900031 ER PT J AU Zehavi, I Dekel, A AF Zehavi, I Dekel, A TI Evidence for a positive cosmological constant from flows of galaxies and distant supernovae SO NATURE LA English DT Article ID DENSITY FIELDS; OMEGA; VELOCITY; LIGHT AB Recent observations(1,2) of high-redshift supernovae seem to suggest that the global geometry of the Universe may be affected by a 'cosmological constant: which acts to accelerate the expansion rate with time. But these data by themselves still permit an open universe of low mass density and no cosmological constant. Here we derive an independent constraint on the lower bound to the mass density, based on deviations of galaxy velocities from a smooth universal expansion(3-7). This constraint rules out a low-density open universe with a vanishing cosmological constant, and together the two favour a nearly flat universe in which the contributions from mass density and the cosmological constant are comparable. This type of universe, however, seems to require a degree of fine tuning of the initial conditions that is in apparent conflict with 'common wisdom'. C1 Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Zehavi, I (reprint author), Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. NR 34 TC 63 Z9 63 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 16 PY 1999 VL 401 IS 6750 BP 252 EP 254 DI 10.1038/45748 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 237VZ UT WOS:000082678400045 ER PT J AU Rohlfing, M Louie, SG AF Rohlfing, M Louie, SG TI Optical reflectivity of the Si(111)-(2x1) surface - The role of the electron-hole interaction SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Surface and Interface Optics 99 (SIO 99) CY MAY 04-09, 1999 CL ST MAXIME, FRANCE SP CNRS, French Minist Affaires Etrangeres, European Phys Soc, ISA Jobin Yvon, Omicron, SOPRA Corp ID AB-INITIO CALCULATION; PARTICLE BAND-STRUCTURE; SI(111)2X1 SURFACE; DIFFERENTIAL REFLECTIVITY; SEMICONDUCTOR SURFACES; STATE BAND; ABSORPTION; SPECTROSCOPY; INSULATORS; SI AB We calculate the optical reflectivity of the Si(111)-(2 x 1) surface from first principles. To this end, we first calculate the quasiparticle band structure of the surface within the CW approximation for the electronic self energy. The band structure exhibits two surface bands inside the fundamental bulk band gap. Thereafter the electron-hole interaction is computed for transitions between the relevant bands, the Bethe-Salpeter equation for coupled electron-hole excitations is solved and the optical response is evaluated. In the energy range below the fundamental bulk band gap, the reflectivity spectrum is dominated by a surface exciton at 0.43 eV with an excitonic binding energy of 0.26 eV. Our calculated spectrum is in very good agreement with experimental data from differential reflectivity spectroscopy. C1 Univ Munster, Inst Theoret Phys Festkorperphys 2, D-48149 Munster, Germany. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Rohlfing, M (reprint author), Univ Munster, Inst Theoret Phys Festkorperphys 2, Wilhelm Klemm Str 10, D-48149 Munster, Germany. EM rohlfin@uni-muenster.de NR 26 TC 13 Z9 13 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD SEP 16 PY 1999 VL 175 IS 1 BP 17 EP 22 DI 10.1002/(SICI)1521-396X(199909)175:1<17::AID-PSSA17>3.0.CO;2-R PG 6 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 244NZ UT WOS:000083058800005 ER PT J AU Akushevich, IV Chekanov, SV AF Akushevich, IV Chekanov, SV TI Current-target correlations as a probe of Delta G/G in polarized deep inelastic scattering SO PHYSICS LETTERS B LA English DT Article ID STRUCTURE FUNCTIONS G(1); MONTE-CARLO GENERATOR; PARTON DISTRIBUTIONS; DEUTERON; NUCLEON; PROTON AB The measurement of the polarized gluon distribution function Delta G/G using current-target correlations in the Breit frame of deep inelastic scattering is proposed. The approach is illustrated using a Monte Carlo simulation of polarized ep-collisions for HERA energies. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Natl Ctr Particle & High Energy Phys, Minsk 220040, Byelarus. Argonne Natl Lab, Argonne, IL 60439 USA. RP Akushevich, IV (reprint author), Natl Ctr Particle & High Energy Phys, Bogdanovich Str 153, Minsk 220040, Byelarus. NR 21 TC 0 Z9 0 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 SEP 16 PY 1999 VL 462 IS 3-4 BP 329 EP 334 DI 10.1016/S0370-2693(99)00933-8 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 245WM UT WOS:000083131100014 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Devmal, S Fernandez, A Fox, GF Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B Magnin, J MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Devmal, S Fernandez, A Fox, GF Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B Magnin, J MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C CA Fermilab E791 Collaboration TI Search for rare and forbidden dilepton decays of the D+, D-s(+), and D-0 charmed mesons SO PHYSICS LETTERS B LA English DT Article DE charm; rare; forbidden; decay; dilepton ID PHYSICS AB We report the results of a search for flavor-changing neutral current, lepton-flavor violating, and lepton-number violating decays of D+, D-s(+), and D-0 mesons (and their antiparticles) into modes containing muons and electrons. Using data from Fermilab charm hadroproduction experiment E791, we examine the pi ll and Kll decay modes of D+ and D-s(+) and the l(+)l(-) decay modes of D-0. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 24 decay modes examined. Eight of these modes have no previously reported limits, and fourteen are reported with significant improvements over previously published results. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Mississippi, University, MS 38677 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. CINVESTAV, Mexico City 07000, DF, Mexico. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. IIT, Chicago, IL 60616 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Massachusetts, Amherst, MA 01003 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Autonoma Puebla, Puebla, Mexico. Univ S Carolina, Columbia, SC 29208 USA. Stanford Univ, Stanford, CA 94305 USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. Tufts Univ, Medford, MA 02155 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Amato, S (reprint author), Univ Mississippi, University, MS 38677 USA. RI Anjos, Joao/C-8335-2013; Santoro, Alberto/E-7932-2014; Gobel Burlamaqui de Mello, Carla /H-4721-2016; de Mello Neto, Joao/C-5822-2013 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; de Mello Neto, Joao/0000-0002-3234-6634 NR 19 TC 41 Z9 42 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 SEP 16 PY 1999 VL 462 IS 3-4 BP 401 EP 409 DI 10.1016/S0370-2693(99)00902-8 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 245WM UT WOS:000083131100022 ER PT J AU Peters, RG Scott, BL Burns, CJ AF Peters, RG Scott, BL Burns, CJ TI Chloro(p-chloroanilido-N)bis(eta(5)-pentamethylcyclopentadienyl)uranium( IV) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID SOLUTION DYNAMICS; COMPLEXES AB The title complex, [UCl(C10H15)(2)(C6H5ClN)], adopts the pseudo-tetrahedral geometry typical for bis(pentamethylcyclopentadienyl)uranium complexes, with a chloride and a para-substituted amide ligand occupying the plane bisecting the metallocene unit. Some important bond lengths include U-N 2.237(3) and U-Cl 2.613 (1) Angstrom. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Peters, RG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 10 TC 14 Z9 14 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD SEP 15 PY 1999 VL 55 BP 1482 EP 1483 DI 10.1107/S0108270199007143 PN 9 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 242XZ UT WOS:000082969100042 ER PT J AU Painter, S Mahinthakumar, G AF Painter, S Mahinthakumar, G TI Prediction uncertainty for tracer migration in random heterogeneities with multifractal character SO ADVANCES IN WATER RESOURCES LA English DT Article ID GAUSSIAN SCALING BEHAVIOR; FRACTIONAL LEVY MOTION; SEDIMENTARY FORMATIONS; POROUS FORMATIONS; EVOLVING SCALES; DISTRIBUTIONS; VARIABILITY; TRANSPORT; AQUIFER; FIELDS AB Travel-time statistics for non-reacting tracers in fractal and multifractal media are addressed through numerical simulations. The logarithm of hydraulic conductivity is modeled using fractional Brownian motion (fBm) and more recently developed multifractal model based on bounded fractional Levy motion (bfLm). These models have been shown previously to accurately reproduce statistical properties of large conductivity datasets. The ensemble-mean travel time increases nearly linearly with travel distance and the variance in the travel time increases nearly parabolically with travel distance. This is consistent with near-field analytical approximations developed for non-fractal media and suggests that these analytical results may have some degree of robustness to non-ideal features in the random-held models. The magnitudes of the travel-time moments are dependent on the system size. For fBm media, this size dependence can be explained using an effective variance that increases with increasing size of the flow system. However, the magnitudes of the travel-time moments are also sensitive to other non-ideal effects such as deviations from Gaussian behavior. This sensitivity illustrates the need for careful aquifer characterization and conditional numerical simulation in practical situations requiring accurate estimates of uncertainty in the plume position. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 CSIRO, Australian Petr Cooperat Res Ctr, Glen Waverley, Vic 3150, Australia. Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. RP Painter, S (reprint author), SW Res Inst, Ctr Nucl Waste Regulatory Anal, 6220 Culebra Rd, San Antonio, TX 78238 USA. RI Painter, Scott/C-2586-2016 OI Painter, Scott/0000-0002-0901-6987 NR 28 TC 12 Z9 14 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD SEP 15 PY 1999 VL 23 IS 1 BP 49 EP 57 DI 10.1016/S0309-1708(99)00004-4 PG 9 WC Water Resources SC Water Resources GA 239DA UT WOS:000082752500004 ER PT J AU Taranenko, NI Potter, NT Allman, SL Golovlev, VV Chen, CH AF Taranenko, NI Potter, NT Allman, SL Golovlev, VV Chen, CH TI Gender identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID HOMOLOGOUS GENE AMELOGENIN; DNA SEX TEST; DESORPTION IONIZATION; SEQUENCING REACTIONS; STRANDED-DNA; OLIGONUCLEOTIDES; AMPLIFICATION; MUTATION AB A rapid, simple, and reliable gender determination of human DNA samples was successfully obtained using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Detection sensitivity reached 0.01 ng or less for DNA samples. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Chen, CH (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Allman, Steve/A-9121-2011 OI Allman, Steve/0000-0001-6538-7048 NR 26 TC 4 Z9 4 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1999 VL 71 IS 18 BP 3974 EP 3976 DI 10.1021/ac990150w PG 3 WC Chemistry, Analytical SC Chemistry GA 235ZD UT WOS:000082573000009 PM 10500484 ER PT J AU Wang, DJ Shin, JY Cheney, MA Sposito, G Spiro, TG AF Wang, DJ Shin, JY Cheney, MA Sposito, G Spiro, TG TI Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID UNITED-STATES; HERBICIDES; PESTICIDES; SOILS AB The herbicide atrazine is widely distributed in the environment, and its reactivity with soil minerals is an important issue. We have studied atrazine degradation on the surface of synthetic hydrous (10% H(2)O) delta-MnO(2) (birnessite) using UV resonance Raman spectroscopy and gas chromatography. The products are mainly mono- and didealkyl atrazine. Atrazine disappearance is rapid (tau(1/2) similar to 5 h at 30 degrees C), independent of whether O(2) is present or not. MnO(2) reduction is a minor reaction, and the alkyl chains are converted mainly to the alkenes, in a nonredox process. A novel dealkylation mechanism is proposed involving proton transfer to Mn(IV)-stablized oxo and imido hands. When O(2) is present, olefin oxidation and ring mineralization are also observed as secondary reactions in addition to those discussed above. Thus delta-MnO(2), a common soil constituent, is found to promote efficient N-dealkylation of the herbicide atrazine at 30 degrees C, via a nonoxidative mechanism. C1 Rutgers State Univ, Cook Coll, Dept Environm Sci, New Brunswick, NJ 08901 USA. Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Cheney, MA (reprint author), Rutgers State Univ, Cook Coll, Dept Environm Sci, New Brunswick, NJ 08901 USA. EM cheney@AESOP.Rutgers.edu; spiro@chemvax.princeton.edu NR 26 TC 28 Z9 31 U1 4 U2 31 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 SEP 15 PY 1999 VL 33 IS 18 BP 3160 EP 3165 DI 10.1021/es990419t PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 236RX UT WOS:000082613300016 ER PT J AU Yano, H Wang, BE Ahmad, I Zhang, JZ Abo, T Nakayama, J Krempen, K Kohwi, Y AF Yano, H Wang, BE Ahmad, I Zhang, JZ Abo, T Nakayama, J Krempen, K Kohwi, Y TI Identification of (CAG)(n) and (CGG)(n) repeat-binding proteins, CAGERs expressed in mature neurons of the mouse brain SO EXPERIMENTAL CELL RESEARCH LA English DT Article DE CAGERs; Pur alpha/beta; (CAG) and (CGG) repeats; neurons; triplet-repeat diseases ID SINGLE-STRANDED-DNA; PUR-ALPHA; TRINUCLEOTIDE REPEATS; GENE; REPLICATION; RECEPTOR; RNA; TRANSCRIPTION; DISORDERS; SEQUENCE AB The trinucleotide repeats (CAG)(n) and (GGG)(n) have been shown to be expanded in responsible genes of several human hereditary neurological disorders. In studies of mice, we previously identified two homologous single-stranded (ss)(CAG) and ss(CGG) repeat-binding proteins, CAGER-1 (44 kDa) and CAGER-2 (40 kDa) (CAG-element-recognizing proteins). The specific binding activities of these proteins were predominantly detected in the mouse brain. We have isolated the cDNAs encoding CAGER-1 and CAGER-2 and found that they were identical to previously reported cDNAs for Pur alpha and Pur beta, respectively. Pur alpha of 28 kDa was previously identified as a replication-origin-binding protein that is ubiquitously expressed in proliferating cells. We show that the transcripts of CAGERs increase after birth and are detected at high levels in the adult mouse brain but at very low or virtually undetectable levels in other mouse tissues. Biochemical properties and molecular weights are different between CAGERs and Pur alpha/beta. Immunostaining with specific antibodies against CAGERs indicates that CAGERs in the mouse brain reside in nonproliferating neurons but not in proliferating glia. We conclude that CAGERs and Pur alpha/beta are unrelated proteins, and CAGERs are neuronal single-stranded sequence-binding proteins in the mouse brain. Misassignment of cDNAs is described. (C) 1999 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kohwi, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 70A-1118, Berkeley, CA 94720 USA. RI ABO, Tatsuhiko/B-1496-2011 FU NCI NIH HHS [R01CA51377] NR 28 TC 6 Z9 7 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0014-4827 J9 EXP CELL RES JI Exp. Cell Res. PD SEP 15 PY 1999 VL 251 IS 2 BP 388 EP 400 DI 10.1006/excr.1999.4603 PG 13 WC Oncology; Cell Biology SC Oncology; Cell Biology GA 238GF UT WOS:000082702000014 PM 10471324 ER PT J AU Liemohn, MW Kozyra, JU Jordanova, VK Khazanov, GV Thomsen, MF Cayton, TE AF Liemohn, MW Kozyra, JU Jordanova, VK Khazanov, GV Thomsen, MF Cayton, TE TI Analysis of early phase ring current recovery mechanisms during geomagnetic storms SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOSYNCHRONOUS ORBIT; FEBRUARY 1986; LOSSES AB A time-dependent kinetic model is used to investigate the relative importance of various mechanisms in the early phase decay rate of the ring current. It is found that, for both the solar maximum storm of June 4-7, 1991 and especially the solar minimum storm of September 24-27, 1998, convective drift loss out the dayside magnetopause is the dominant process in removing ring current particles during the initial recovery. During the 1998 storm, dayside outflow losses outpaced charge exchange losses by a factor of ten. C1 Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Liemohn, MW (reprint author), Univ Michigan, Space Phys Res Lab, 2455 Hayward St, Ann Arbor, MI 48109 USA. RI Liemohn, Michael/H-8703-2012; OI Liemohn, Michael/0000-0002-7039-2631; Jordanova, Vania/0000-0003-0475-8743 NR 17 TC 119 Z9 119 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1999 VL 26 IS 18 BP 2845 EP 2848 DI 10.1029/1999GL900611 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 237WV UT WOS:000082680300017 ER PT J AU Vaidyanathan, R Bourke, MAM Dunand, DC AF Vaidyanathan, R Bourke, MAM Dunand, DC TI Analysis of neutron diffraction spectra acquired in situ during stress-induced transformations in superelastic NiTi SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RIETVELD REFINEMENT; DEFORMATION; BEHAVIOR; ALLOYS AB Neutron diffraction spectra were obtained during various stages of a reversible stress-induced austenite to martensite phase transformation in superelastic NiTi. This was accomplished by neutron diffraction measurements on bulk polycrystalline NiTi samples simultaneously subjected to mechanical loading. Analysis of the data was carried out using individual lattice plane (hkl) reflections as well as by Rietveld refinement. In the Rietveld procedure, strains in austenite were described in terms of an isotropic (hkl independent) and an anisotropic (hkl dependent) component. At higher stresses, austenite lattice plane reflections exhibited nonlinear and dissimilar elastic responses which may be attributed to the transformation. The texture evolution is significant in both austenite and martensite phases during the transformation and two approaches were used to describe this evolving texture, i.e., an ellipsoidal model due to March-Dollase and a generalized spherical-harmonic approach. The respective predictions of the phase fraction evolution as a function of applied stress were compared. A methodology is thus established to quantify the discrete phase strains, phase volume fractions, and texture during such transformations. (C) 1999 American Institute of Physics. [S0021-8979(99)09118-5]. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Calif Los Alamos Natl Lab, LANSCE MST, Los Alamos, NM 87545 USA. RP Vaidyanathan, R (reprint author), MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RI Dunand, David/B-7515-2009; OI Dunand, David/0000-0001-5476-7379 NR 29 TC 35 Z9 37 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1999 VL 86 IS 6 BP 3020 EP 3029 DI 10.1063/1.371163 PG 10 WC Physics, Applied SC Physics GA 230BU UT WOS:000082232400014 ER PT J AU Myers, SM Follstaedt, DM AF Myers, SM Follstaedt, DM TI Forces between cavities and dislocations and their influence on semiconductor microstructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAS-BUBBLE SUPERLATTICE; STAINLESS-STEEL; SURFACE STRESS; SILICON; HELIUM; METALS; SI; COPPER; IMPLANTATION; IRRADIATION AB An approximate continuum method for computing the energy of interaction between cavities and strain fields in complex configurations is described and tested by comparison with results for simple, exactly solvable cases. The method is then used to examine semiquantitatively the effective forces between cavities and screw and edge dislocations, taking into account the effects of surface tension and pressurized gas within the cavity. The discussion encompasses not only local interactions involving individual cavities, but also the combined forces acting upon dislocations in the vicinity of multiple cavities and simultaneously within range of external-surface image forces. The results are used to interpret a range of observed microstructures in semiconductors and to assess the possible exploitation of cavity-dislocation binding for dislocation control in Si-Ge heteroepitaxial structures. (C) 1999 American Institute of Physics. [S0021-8979(99)05518-8]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Myers, SM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 48 TC 15 Z9 15 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1999 VL 86 IS 6 BP 3048 EP 3063 DI 10.1063/1.371167 PG 16 WC Physics, Applied SC Physics GA 230BU UT WOS:000082232400018 ER PT J AU Crew, DC McCormick, PG Street, R AF Crew, DC McCormick, PG Street, R TI An investigation of reversible magnetization in NdFeB SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PERMANENT-MAGNETS; VISCOSITY; FIELDS AB Magnetization reversal processes in sintered and melt-quenched NdFeB materials have been investigated by measurements of reversible magnetization. For isotropic and anisotropic sintered NdFeB and anisotropic hot pressed die upset NdFeB (MQIII) reversible magnetization is the result of bowing of pinned domain boundary walls. In contrast in isotropic melt quenched NdFeB (MQI) reversible magnetization appears to be the result of the rotation of domain magnetization vectors and not domain wall bowing. The differences in the reversible magnetization processes of the four materials investigated are determined. (C) 1999 American Institute of Physics. [S0021-8979(99)08418-2]. C1 Univ Western Australia, Special Res Ctr Adv Mineral & Mat Proc, Perth, WA 6907, Australia. RP Crew, DC (reprint author), Brookhaven Natl Lab, Bldg 480, Upton, NY 11973 USA. NR 15 TC 49 Z9 49 U1 2 U2 17 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1999 VL 86 IS 6 BP 3278 EP 3284 DI 10.1063/1.371202 PG 7 WC Physics, Applied SC Physics GA 230BU UT WOS:000082232400054 ER PT J AU Poles, E Huppert, D Hanna, MC Rosenwaks, Y AF Poles, E Huppert, D Hanna, MC Rosenwaks, Y TI Measuring hot electron temperatures in semiconductors under high injection levels SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CARRIERS; GAAS AB One of the most widely used methods to measure the excess carrier temperature in semiconductors is super band gap time-resolved photoluminescence. We find that under high carrier injection levels the formalism commonly used to extract the electron temperature using this method is erroneous due to the neglect of the role of the quasi-Fermi levels. A method that can be used to obtain accurate carrier temperatures while taking into account the important factors affecting the excess carrier concentration is proposed. The method is used to analyze time-resolved photoluminescence measurements performed on thin GaAs epilayers. It is found that the proposed method accurately corrects the apparent slow electron cooling frequently found in bulk semiconductors. (C) 1999 American Institute of Physics. [S0021-8979(99)05918-6]. C1 Tel Aviv Univ, Sch Chem, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. Natl Renewable Energy Lab, Golden, CO 80401 USA. Tel Aviv Univ, Fac Engn, Dept Phys Elect, IL-69978 Tel Aviv, Israel. RP Poles, E (reprint author), Tel Aviv Univ, Sch Chem, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. NR 9 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1999 VL 86 IS 6 BP 3481 EP 3483 DI 10.1063/1.371235 PG 3 WC Physics, Applied SC Physics GA 230BU UT WOS:000082232400088 ER PT J AU Gomez-Vega, JM Saiz, E Tomsia, AP AF Gomez-Vega, JM Saiz, E Tomsia, AP TI Glass-based coatings for titanium implant alloys SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE glass coatings; Ti6Al4V; silicate; bioactivity; hydroxyapatite ID HYDROXYAPATITE COATINGS; IN-VITRO; METAL; INTERFACES; TI; SAPPHIRE; BEHAVIOR; SILICA AB Glass coatings on Ti6Al4V were prepared using a simple enameling technique. The composition of the glasses was tailored to match the thermal expansion of Ti6Al4V. By controlling the firing atmosphere, time, and temperature, it was possible to control the reactivity between the glass and the alloy and to fabricate coatings (25-150 mu m thick) with excellent adhesion to the substrate. The optimum firing temperatures ranged between 800 and 840 degrees C at times up to 1 min in air or 15 min in N-2. The same basic technique was used to prepare multilayered coatings with graded composition or with hydroxyapatite (HA) particles embedded in the outer layer. Some of these coatings presented excellent adhesion to the substrate and were able to form HA during in vitro tests in simulated body fluid. (C) 1999 John Wiley & Sons, Inc. C1 Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Tomsia, AP (reprint author), Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. FU NIDCR NIH HHS [1R01DE11289] NR 33 TC 100 Z9 104 U1 1 U2 8 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD SEP 15 PY 1999 VL 46 IS 4 BP 549 EP 559 DI 10.1002/(SICI)1097-4636(19990915)46:4<549::AID-JBM13>3.0.CO;2-M PG 11 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 213WE UT WOS:000081295600013 PM 10398016 ER PT J AU Bise, RT Choi, H Neumark, DM AF Bise, RT Choi, H Neumark, DM TI Photodissociation dynamics of the singlet and triplet states of the NCN radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER EXCITATION SPECTROSCOPY; FLIGHT MASS-SPECTROMETER; AB-INITIO; HOT-BAND; ION BEAM; OZONE; TIME; CNN; SCATTERING; MOLECULES AB The spectroscopy and photodissociation dynamics of the NCN radical have been investigated by fast beam photofragment translational spectroscopy. The (B) over tilde (3)Sigma(u)(-)<-- (X) over tilde (3)Sigma(g)(-), (c) over tilde (1)Pi(u)<--(a) over tilde (1)Delta(g), and (d) over tilde (1)Delta(u)<--(a) over tilde (1)Delta(g) transitions were examined. The major dissociation products for the (B) over tilde (3)Sigma(u)(-) and (c) over tilde (1)Pi(u) states are N-2((X) over tilde (1)Sigma(g)(+))+C(P-3), while the (d) over tilde (1)Delta(u) state dissociates to N-2((X) over tilde (1)Sigma(g)(+))+C(D-1). The dissociation channel, N(S-4)+CN((X) over tilde (2)Sigma(+)) is observed for the (B) over tilde (3)Sigma(u)(-) state at photon energies greater than 4.9 eV, where it comprises approximate to 25 +/- 10% of the total signal. At all photon energies, the photofragment translational energy distributions show a resolved progression corresponding to the vibrational excitation of the N-2 photofragment. The rotational distributions of the molecular fragments suggest that the dissociation pathway for the N-2 loss channel involves a bent transition state while the N+CN photofragments are produced via a linear dissociation mechanism. The P(E-T) distributions provide bond dissociation energies of 2.54 +/- 0.030 and 4.56 +/- 0.040 eV for the N-2 and CN loss channels, respectively, yielding Delta H-f,H-0 K(NCN)=4.83 +/- 0.030 eV. (C) 1999 American Institute of Physics. [S0021-9606(99)00535-8]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 56 TC 28 Z9 28 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1999 VL 111 IS 11 BP 4923 EP 4932 DI 10.1063/1.479751 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 233AB UT WOS:000082402400009 ER PT J AU Boldyrev, AI Simons, J Li, X Wang, LS AF Boldyrev, AI Simons, J Li, X Wang, LS TI The electronic structure and chemical bonding of hypermetallic Al5C by ab initio calculations and anion photoelectron spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-ORBITAL METHODS; GAUSSIAN-BASIS SETS; GREEN-FUNCTION; ALUMINUM CLUSTERS; ATOMS; OXIDATION; EXCHANGE; SURFACES AB The chemical structure and bonding of the hypermetallic Al5C and Al5C- species have been studied by photoelectron spectroscopy and ab initio calculations. Both Al5C (C-2v, (2)A(1)) and Al5C- (C-2v, (1)A(1)) are found to have planar structures that can be related to that of the planar square Al4C- by adding one Al+ ion or one Al atom to an edge of the square. The planarity of Al5C and Al5C- can be explained in terms of the structure of their highest occupied molecular orbitals which are ligand five-center one- or two-electron bonding MO, respectively, similar to the orbital responsible for the planarity of Al4C-. Four peaks were observed in the photoelectron spectra of Al5C- with vertical binding energies of 2.67, 2.91, 3.19, and 4.14 eV which compare well with the 2.68, 2.96, 3.27, and 4.35 eV calculated by the Green function method [OVGF/6-311+G(2df )]. The excellent agreement between the calculated and experimental electron affinity and excitation energies allow us to completely elucidate the geometrical and electronic structures of Al5C- and suggest the most likely structure for the Al5C molecule. (C) 1999 American Institute of Physics. [S0021-9606(99)01035-1]. C1 Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Boldyrev, AI (reprint author), Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. RI Boldyrev, Alexander/C-5940-2009 OI Boldyrev, Alexander/0000-0002-8277-3669 NR 41 TC 26 Z9 27 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1999 VL 111 IS 11 BP 4993 EP 4998 DI 10.1063/1.479744 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 233AB UT WOS:000082402400017 ER PT J AU Shkrob, IA Tadjikov, BM Chemerisov, SD Trifunac, AD AF Shkrob, IA Tadjikov, BM Chemerisov, SD Trifunac, AD TI Electron trapping and hydrogen atoms in oxide glasses SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RESONANCE SPECTROSCOPY; THERMO-LUMINESCENCE; RADIATION-CHEMISTRY; DISORDERED SOLIDS; SILICATE-GLASSES; AMORPHOUS SILICA; GATE OXIDES; BORIC-ACID; H-ATOM; DIFFUSION AB Trapped hydrogen atoms generated in 3 MeV beta-radiolysis of B2O3:OH glass below 140 K were studied using electron paramagnetic resonance (EPR). Two types of trapped H atoms were present in this glass; one was an interstitial atom located in a void between several BOB fragments, another was the atom trapped in a cage between two B3O6 (boroxol) rings connected by hydrogen bonds. The geometry of the trapping site was determined using electron spin echo envelope modulation (ESEEM) spectroscopy. Time-resolved pulsed EPR was used to observe mobile H atoms at 300-500 K. The lifetimes (10-100 mu s) of the H atoms were controlled by similar to 10(18) cm(-3) of metastable spin centers. The H atoms migrated with diffusion constant of 1.5x10(7) cm(2)/s (activation energy of 0.13-0.16 eV), mean residence time at the site of 4-5 ns, and mean jump length of 0.56 nm (at 300 K). This site-to-site migration causes rapid spin relaxation due to modulation of magnetic interactions, such as dipole-dipole interaction of the unpaired electron of the H atom with B-10 and B-11 nuclei. Though there was no observed H/D kinetic isotope effect on the decay/diffusion of the hydrogen atoms, there was a significant isotope effect on their radiolytic yield (alpha approximate to 1.5-1.6). This effect is comparable to the one observed in SiO2:OH and aqueous acid glasses. This similarity suggests that in the room-temperature "wet" SiO2 and B2O3 glasses, mobile H atoms are generated via electron trapping at the proton(s) associated with threefold coordinated oxygen (-OH2+ and/or > OH+ centers). Semiempirical MNDO simulations were used to estimate energetics of such electron trapping reactions. [S0021-9606(99)52335-0]. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 94 TC 9 Z9 9 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1999 VL 111 IS 11 BP 5124 EP 5140 DI 10.1063/1.479740 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 233AB UT WOS:000082402400031 ER PT J AU Stoldt, CR Jenks, CJ Thiel, PA Cadilhe, AM Evans, JW AF Stoldt, CR Jenks, CJ Thiel, PA Cadilhe, AM Evans, JW TI Smoluchowski ripening of Ag islands on Ag(100) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO SIMULATION; SIZE DISTRIBUTIONS; CLUSTER DIFFUSION; AG/AG(100) HOMOEPITAXY; VACANCY CLUSTERS; BROWNIAN-MOTION; SOLID-SURFACES; GROWTH; COALESCENCE; KINETICS AB Using scanning tunneling microscopy, we study the post-deposition coarsening of distributions of large, two-dimensional Ag islands on a perfect Ag(100) surface at 295 K. The coarsening process is dominated by diffusion, and subsequent collision and coalescence of these islands. To obtain a comprehensive characterization of the coarsening kinetics, we perform tailored families of experiments, systematically varying the initial value of the average island size by adjusting the amount of Ag deposited (up to 0.25 ML). Results unambiguously indicate a strong decrease in island diffusivity with increasing island size. An estimate of the size scaling exponent follows from a mean-field Smoluchowski rate equation analysis of experimental data. These rate equations also predict a rapid depletion in the initial population of smaller islands. This leads to narrowing of the size distribution scaling function from its initial form, which is determined by the process of island nucleation and growth during deposition. However, for later times, a steady increase in the width of this scaling function is predicted, consistent with observed behavior. Finally, we examine the evolution of Ag adlayers on a strained Ag(100) surface, and find significantly enhanced rates for island diffusion and coarsening. (C) 1999 American Institute of Physics. [S0021-9606(99)70135-2]. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, IPRT, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. RP Stoldt, CR (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RI Cadilhe, Antonio/G-1479-2016 OI Cadilhe, Antonio/0000-0002-0252-6992 NR 54 TC 41 Z9 41 U1 1 U2 14 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1999 VL 111 IS 11 BP 5157 EP 5166 DI 10.1063/1.479770 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 233AB UT WOS:000082402400034 ER PT J AU Peterka, DS Ahmed, M Suits, AG Wilson, KJ Korkin, A Nooijen, M Bartlett, RJ AF Peterka, DS Ahmed, M Suits, AG Wilson, KJ Korkin, A Nooijen, M Bartlett, RJ TI Unraveling the mysteries of metastable O-4* (vol 110, pg 6095, 1999) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction C1 Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Florida, Quantum Theory Project, Gainesville, FL 32611 USA. RP Suits, AG (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Ahmed, Musahid/A-8733-2009 NR 7 TC 6 Z9 6 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1999 VL 111 IS 11 BP 5279 EP 5279 DI 10.1063/1.479742 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 233AB UT WOS:000082402400048 ER PT J AU Towle, SN Brown, GE Parks, GA AF Towle, SN Brown, GE Parks, GA TI Sorption of Co(II) on metal oxide surfaces I. Identification of specific binding sites of Co(II) on (110) and (001) surfaces of TiO2 (rutile) by grazing-incidence XAFS spectroscopy SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE Co(II); TiO2; rutile surface; surfaces; sorption; XAFS; XAFS spectroscopy; grazing-incidence XAFS; oxide-water interface ID RAY-ABSORPTION-SPECTROSCOPY; MULTIPLE-SCATTERING; WATER INTERFACE; FINE-STRUCTURE; MODEL SYSTEMS; ADSORPTION; IONS; COMPLEXES; ALUMINA; EXAFS AB We have examined the molecular-scale details of aqueous Co(II) surface complexes and the types of surface sites to which these complexes bind on the (110) and (001) surfaces of single-crystal TiO2 (rutile) using polarization-dependent grazing-incidence Xray absorption fine structure (GI-XAFS) spectroscopy under ambient conditions in a humid atmosphere. On both surfaces, Co(II) adsorbs at sites corresponding to Ti-equivalent positions in an extension of the rutile structure. This result suggests that even if different crystallographic surfaces of metal oxides have strongly differing adsorption properties for gaseous species in ultra-high vacuum, they can have similar properties for adsorption of metal ions in aqueous solution, probably due to the tendency of liquid water to heal defects and satisfy the bonding requirements of coordinatively unsaturated surface atoms. Using a bond valence approach in combination with the XAFS results, we have proposed specific surface reactions for sorption of Co(II) on the (110) and (001) rutile surfaces as a function of pH and Co surface concentration. No evidence was found for well-ordered Co(II)-hydroxide-like precipitates that would show Co-Co pair correlations, or for Co-Ti pair correlations similar to those in anatase, as have been observed in other studies. These results demonstrate the utility of GI-XAFS spectroscopy on adsorbed metal ions at submonolayer surface coverages for determining the types of reactive sorption sites on metal oxide surfaces. (C) 1999 Academic Press. C1 Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Brown, GE (reprint author), Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. NR 43 TC 70 Z9 70 U1 1 U2 11 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 EI 1095-7103 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD SEP 15 PY 1999 VL 217 IS 2 BP 299 EP 311 DI 10.1006/jcis.1999.6264 PG 13 WC Chemistry, Physical SC Chemistry GA 239VG UT WOS:000082789900008 ER PT J AU Towle, SN Bargar, JR Brown, GE Parks, GA AF Towle, SN Bargar, JR Brown, GE Parks, GA TI Sorption of Co(II) on metal oxide surfaces II. Identification of Co(II)(aq) adsorption sites on the (0001) and (1(1)over-bar02) surfaces of alpha-Al2O3 by grazing-incidence XAFS spectroscopy SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE Co(II); Al2O3; surfaces; sorption; XAFS; grazing-incidence XAFS; oxide-water interface ID RAY-ABSORPTION-SPECTROSCOPY; WATER INTERFACE; ALPHA-ALUMINA; MULTIPLE-SCATTERING; FINE-STRUCTURE; GAMMA-ALUMINA; IONS; COMPLEXATION; PRECIPITATION; AL2O3 AB We have characterized the adsorption of Co(II) on the (0001) and (<1(1)over bar 02>) surfaces of alpha-Al2O3 single crystals under ambient conditions using polarization-dependent grazing-incidence X-ray absorption fine structure spectroscopy, in combination with bond valence modeling. Co(II) ions were found to be adsorbed on both surfaces in an inner-sphere fashion. Adions were found to adsorb dominantly in a tridentate fashion (i.e., bonded to three surface oxygens) on the (0001) surface and dominantly in a tetradentate fashion on the (<1(1)over bar 02>) surface. Based on EXAFS results and bond valence analysis, plausible surface complexation reactions for Co(II) sorption on these two surfaces can be written as [GRAPHICS] where (Al-OH2), [GRAPHICS] and [GRAPHICS] represent surface water molecules, hydroxyl groups, and oxygens bonded to one, two, and three Al cations, respectively. (C) 1999 Academic Press. C1 Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Brown, GE (reprint author), Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. NR 46 TC 60 Z9 62 U1 1 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD SEP 15 PY 1999 VL 217 IS 2 BP 312 EP 321 DI 10.1006/jcis.1999.6351 PG 10 WC Chemistry, Physical SC Chemistry GA 239VG UT WOS:000082789900009 ER PT J AU Rector, DM Rogers, RF George, JS AF Rector, DM Rogers, RF George, JS TI A focusing image probe for assessing neural activity in vivo SO JOURNAL OF NEUROSCIENCE METHODS LA English DT Article DE blood flow; depth viewing; optical imaging; light scattering ID FREELY BEHAVING ANIMALS; NEURONAL-ACTIVITY; VOLUME CHANGES; BLOOD-FLOW; STIMULATION; OXYGENATION; SIGNALS AB We describe a compact, focusing image probe to record rapid optical changes from neural tissue. A gradient index (GRIN) lens served as a relay lens from tissue to a microscope objective which projected an image onto a CCD camera. The microscope objective and camera assembly was adjusted independently from the GRIN lens, allowing focus changes without disturbing the probe/tissue interface; firm contact minimized movement and specular reflectance. Fiber optics around the probe perimeter provided diffuse illumination from a 780 nn laser, or 660 and 560 nm light emitting diodes. To characterize depth-of-field, we imaged a black suture through increasing tissue thicknesses. Light modulation by the suture remained detectable down to 900 mu m using 780 nm illumination. We acquired images from cardiorespiratory areas of the rat dorsal medulla, at different depths and illumination wavelengths. Images illuminated at 560 nm were dominated by vasculature flow patterns, while 660 nm illumination revealed different spatial patterns which preceded vascular flow by 40 ms and may represent cardiac-related neural activity. Using 780 nm light, image sequences triggered by the cardiac R-wave showed vascular perfusion changes with delayed and broader responses at deeper levels. Electrical stimulation within the vagal bundle caused fast optical changes which track the electrical response, with a different spatial distribution from hemodynamic signals. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Biophys Grp, Los Alamos, NM 87545 USA. DuPont Co Inc, Cent Res & Dev, Wilmington, DE 19880 USA. RP George, JS (reprint author), Los Alamos Natl Lab, Biophys Grp, POB 1663,P-21,MS-D454, Los Alamos, NM 87545 USA. EM jsg@lanl.gov FU NHLBI NIH HHS [1-R01-HL-54194] NR 18 TC 34 Z9 35 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-0270 J9 J NEUROSCI METH JI J. Neurosci. Methods PD SEP 15 PY 1999 VL 91 IS 1-2 BP 135 EP 145 DI 10.1016/S0165-0270(99)00088-6 PG 11 WC Biochemical Research Methods; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA 241ZB UT WOS:000082912800014 PM 10522832 ER PT J AU Riise, BL Mikler, N Denn, MM AF Riise, BL Mikler, N Denn, MM TI Rheology of a liquid crystalline polymer dispersed in a flexible polymer matrix SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article; Proceedings Paper CT Conference on Mechanics of Non-Linear Materials CY MAY 13-16, 1998 CL BANFF, CANADA SP Tulane Univ, Sch Engn, Univ Calgary, Fac Engn & Bituminous Mat Chair, NJ Inst Technol DE blend; liquid crystalline polymer; Palierne model; emulsion model; Doi-Ohta model ID SHEAR FLOWS; BLENDS; MORPHOLOGY; STEADY; HYDROXYPROPYLCELLULOSE; BEHAVIOR; MODEL; PHASE AB The addition of 10% of an aqueous lyotropic liquid crystalline dispersed phase to an isotropic polydimethylsiloxane melt increases the steady shear and normal stresses and the dynamic moduli, but the increase caused by the liquid crystalline dispersed phase is much less than expected from the Palierne and Doi-Ohta theories of blends. In contrast, the Palierne theory does an adequate job of predicting the linear viscoelastic behavior of a blend with a 20% LCP dispersed phase. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Denn, MM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 21 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD SEP 15 PY 1999 VL 86 IS 1-2 BP 3 EP 14 DI 10.1016/S0377-0257(98)00199-2 PG 12 WC Mechanics SC Mechanics GA 235ZA UT WOS:000082572700002 ER PT J AU Lu, LD Lachicotte, RJ Penner, TL Perlstein, J Whitten, DG AF Lu, LD Lachicotte, RJ Penner, TL Perlstein, J Whitten, DG TI Exciton and charge-transfer interactions in nonconjugated merocyanine dye dimers: Novel solvatochromic behavior for tethered bichromophores and excimers SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MICROHETEROGENEOUS MEDIA; PHOTOPHYSICS; ASSEMBLIES; MOLECULES; DYNAMICS AB A series of merocyanine dye dimers tethered at different sites with spacers ranging from 0 to 5 methylene groups and the corresponding monomer have been synthesized. The formation, structure, and excited-state properties of the consequent merocyanine dye "aggregates" in solutions and in rigid glass have been studied by UV/visible absorption spectra, steady-state fluorescence, and fluorescence lifetime measurements. The dimers with 0 and 1 methylene spacers must exist in more-or-less extended conformations; consequently, they show a very weak and distance-dependent "J"-type exciton coupling, evident in both absorption and fluorescence spectra. For the dimers with 2, 3, and 5 methylene spacers, absorption spectra in nonpolar solvents are consistent with a largely extended configuration and little or no evident exciton coupling. However, for more polar solvents, a blue shifted absorption spectrum is observed, suggesting a folded configuration resulting in an "H" dimer. For the latter dimers, fluorescence spectra in a variety of solvents show a pronounced redshift, which is attributed to a folded "excimer". As anticipated from its structure, the merocyanine monomer shows a weak positive solvatochromic effect that may be correlated using the Taft-Kamlet pi* parameter. Remarkably, both the "J" coupled dimer (n = 0) and the dimers having 2-5 methylene groups show a much stronger solvatochromic behavior than the monomer. The strong solvatochromic effects in these tethered dimers may be attributed to interchromophoric charge-transfer interactions in both ground and excited states. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Rochester, Ctr Photoinduced Charge Transfer, Dept Chem, Rochester, NY 14627 USA. RP Whitten, DG (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 57 Z9 57 U1 4 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 15 PY 1999 VL 121 IS 36 BP 8146 EP 8156 DI 10.1021/ja983778h PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 239KY UT WOS:000082768300003 ER PT J AU Tuinman, AA Gakh, AA Hinde, RJ Compton, RN AF Tuinman, AA Gakh, AA Hinde, RJ Compton, RN TI The first direct observation of the trifluoride anion (F-3(-)) in the gas phase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID AB-INITIO; ION; STABILITY; THERMOCHEMISTRY; FLUORINE; SPECTRA; X=F; F2; CL C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tuinman, AA (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. OI Hinde, Robert/0000-0003-3499-9222 NR 31 TC 26 Z9 26 U1 1 U2 7 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 SEP 15 PY 1999 VL 121 IS 36 BP 8397 EP 8398 DI 10.1021/ja991757x PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 239KY UT WOS:000082768300038 ER PT J AU Larson, DJ Liu, CT Miller, MK AF Larson, DJ Liu, CT Miller, MK TI The alloying effects of tantalum on the microstructure of an alpha(2)+gamma titanium aluminide SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 45th International Field Emission Symposium - Field Emission 98 CY SEP 12-18, 1998 CL IRBID, JORDAN SP Int Field Emiss Soc DE titanium aluminides based on TiAl; alloying effects; tantalum; titanium boride; precipitates; phase composition; atom probe field ion microscopy ID TI-AL; PHASE; ADDITIONS; STABILITY; BETA; TA; SOLUBILITY; SYSTEM; BINARY AB Atom probe field ion microscopy has been used to investigate the alloying effects of tantalum in a hot extruded two-phase (alpha(2) + gamma) Ti-47 at.% Al-2% Cr-1% Nb-0.80% Ta-0.20% W-0.15% B alloy in both stress-relieved (2 h at 900 degrees C) and aged (2160 h at 800 degrees C) conditions. Slightly over half of the tantalum additions were found to be in solution in the main matrix phases. The concentration of tantalum in the aged alloy was determined to be 0.43 +/- 0.14% Ta and 0.47 +/- 0.04% Ta in the alpha(2) and gamma phases, respectively, indicating that tantalum does not partition strongly to either phase. The presence of tantalum does not reduce the strong oxygen partitioning to the alpha(2) phase, or modify the low boron concentrations measured in the alpha(2) and gamma phases. However, the addition of tantalum does appear to change the most prevalent boride phase from MB2 to MB and possibly to increase the rate at which near-equilibrium levels of Al and Ti are achieved in the alpha(2) and gamma phases. In addition, tantalum appears be responsible for the precipitation of a Ti(Cr, Al)(2) phase which contains significant amounts of Ti, Al, Cr, Ta and W. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Larson, DJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM larsondj@ornl.gov NR 26 TC 13 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 1999 VL 270 IS 1 BP 1 EP 8 DI 10.1016/S0921-5093(99)00233-6 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 239KL UT WOS:000082767200002 ER PT J AU Miller, MK Babu, SS Burke, MG AF Miller, MK Babu, SS Burke, MG TI Intragranular precipitation in alloy 718 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 45th International Field Emission Symposium - Field Emission 98 CY SEP 12-18, 1998 CL IRBID, JORDAN SP Int Field Emiss Soc DE alloy 718; precipitates; superalloys AB A combined energy-compensated 3-dimensional atom probe and transmission electron microscope characterization has been performed to determine the nature of the intragranular precipitates that form in Alloy 718 after various stages of a multistage heat treatment. Primary gamma " precipitates were found to form after the 870 degrees C stage. The secondary precipitates formed at lower temperatures were not found to be uniform throughout their volume, but to be divided into two distinct regions enriched in either niobium, or in aluminum and titanium, that are characteristic of the gamma " and gamma' phases, respectively. The experimentally determined partitioning data of the solute elements between the gamma matrix and the gamma " and gamma' phases was found to agree with the trends in the thermodynamic predictions. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Microscopy & Microanalyt Sci Grp, Oak Ridge, TN 37831 USA. Westinghouse Elect Corp, Pittsburgh, PA 15122 USA. RP Miller, MK (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Microscopy & Microanalyt Sci Grp, POB 2008, Oak Ridge, TN 37831 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 6 TC 28 Z9 31 U1 3 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 1999 VL 270 IS 1 BP 14 EP 18 DI 10.1016/S0921-5093(99)00235-X PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 239KL UT WOS:000082767200004 ER PT J AU Kelly, TF Larson, DJ Miller, MK Flinn, JE AF Kelly, TF Larson, DJ Miller, MK Flinn, JE TI Three dimensional atom probe investigation of vanadium nitride precipitates and the role of oxygen and boron in rapidly solidified 316 stainless steel SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 45th International Field Emission Symposium - Field Emission 98 CY SEP 12-18, 1998 CL IRBID, JORDAN SP Int Field Emiss Soc DE three dimensional atom probe; rapid solidification processing; stainless steel 316; precipitation in stainless steel AB A 316 stainless steel that was rapid solidification processed (RSP) by gas atomization and hot extrusion of the powder has been studied previously by conventional atom probe held ion microscopy (APFIM). Vanadium, nitrogen, and oxygen have been introduced intentionally as alloying elements for the purpose of improving the mechanical properties through fine-scale precipitation. Previous efforts to locate the oxygen in the structure using APFIM were inconclusive, largely due to poor counting statistics. An energy-compensated three-dimensional position-sensitive atom probe (3DAP) has been used in the present study to search for oxygen in cavities, precipitates, and grain boundaries in this alloy. As a direct result of the much greater number of atoms detected and the three-dimensional imaging, oxygen concentrations on the order of 1 atomic% have been found both inside nitride precipitates and in the vicinity of grain boundaries. Boron was also found unexpectedly in concentrations of up to 2 atomic% inside nitride precipitates and in the vicinity of grain boundaries. These findings are important to developing an understanding of the grain growth resistance and precipitate stability both in this alloy and in this processing method in general. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Kelly, TF (reprint author), Univ Wisconsin, Dept Mat Sci & Engn, 272 Mat Sci & Engn Bldg,1509 Univ Ave, Madison, WI 53706 USA. NR 15 TC 4 Z9 6 U1 1 U2 6 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 SEP 15 PY 1999 VL 270 IS 1 BP 19 EP 26 DI 10.1016/S0921-5093(99)00239-7 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 239KL UT WOS:000082767200005 ER PT J AU Thuvander, M Miller, MK Stiller, K AF Thuvander, M Miller, MK Stiller, K TI Grain boundary segregation during heat treatment at 600 degrees C in a model Alloy 600 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 45th International Field Emission Symposium - Field Emission 98 CY SEP 12-18, 1998 CL IRBID, JORDAN SP Int Field Emiss Soc DE carbides; Ni-base alloy; grain boundary segregation ID STRESS-CORROSION CRACKING; INCONEL 600; CHEMISTRY; BEHAVIOR AB The carbon distribution in the vicinity of grain boundaries, in solution in the matrix, and in carbides has been studied by the atom probe at various stages of the intergranular carbide precipitation process in an austenitic nickel-base model alloy similar to commercial Alloy 600. The grain boundary precipitation evolved from small discrete carbides after 4 h at 600 degrees C to a semi-continuous carbide film after 16 h, and finally to large discrete carbides after 213 h. Enrichments of carbon, boron, nitrogen and phosphorus were found at the grain boundaries in all ageing conditions. Large variations were observed between different grain boundaries and at different positions of an individual grain boundary in the same ageing condition. The highest carbon concentration was accompanied by chromium enrichment, indicating the nucleation of chromium-carbides. After ageing for 213 h, the amount of carbon segregation to the boundary was very low, which suggests that the driving force for carbon segregation is less than that for carbide precipitation. Phosphorus was only detected at the grain boundaries when the carbon concentration was low. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Chalmers Univ Technol, Dept Expt Phys, SE-41296 Gothenburg, Sweden. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Stiller, K (reprint author), Chalmers Univ Technol, Dept Expt Phys, SE-41296 Gothenburg, Sweden. RI Thuvander, Mattias/N-5329-2014; OI Thuvander, Mattias/0000-0002-6097-6895 NR 13 TC 17 Z9 17 U1 2 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 1999 VL 270 IS 1 BP 38 EP 43 DI 10.1016/S0921-5093(99)00236-1 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 239KL UT WOS:000082767200008 ER PT J AU Ringhofer, S Schreiber, H Steinhauser, O AF Ringhofer, S Schreiber, H Steinhauser, O TI A molecular dynamics simulation study of the unfolding of barnase induced by reaction field perturbation SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID MOLTEN GLOBULE STATE; NUCLEATION-CONDENSATION MECHANISM; PROTEIN ENGINEERING PROCEDURE; PARTICLE MESH EWALD; FOLDING PATHWAY; TRANSITION-STATE; CHYMOTRYPSIN INHIBITOR-2; SECONDARY STRUCTURE; MAGNETIC-RESONANCE; HYDROPHOBIC CORES AB We present a novel method to study protein unfolding by molecular dynamics (MD) simulations. A term resembling a reaction field is added as a perturbation to the Ewald sum, the most commonly used method to calculate electrostatic interactions in MD simulations. This reaction field perturbation (RFP) mimics qualitatively on the level of molecular interactions the changes in a protein solvent system when denaturants (e.g., urea or guadinium chloride) are added. The method is tunable by two parameters that control strength and "type'' (i.e., different regions of the electrostatic interactions can be weakened selectively) of the perturbations. The approach is tested by a detailed unfolding study of barnase based on several simulations, starting from two initial structures and with varying strength of the RFP. Unfolding is studied by following the changes in the radius of gyration, in the root mean square deviation and in the solvent accessible surface area of the protein. On the local level, the loss of secondary structure is monitored. In addition, the calculation of Voronoi volumes of individual side chains and the number of intruding waters as a function of simulation time are used to analyze the hydrophobic cores. We find an unfolding pathway and folding intermediates which agree well with the experimental data available and which are consistent with earlier simulation studies. Since under one set of RFP conditions the intermediate states are stable for approximately 100 ps, it is possible to characterize these states resembling the experimentally observed transition state and folding intermediate in great detail. C1 Univ Vienna, Inst Theoret Phys, A-1090 Vienna, Austria. RP Ringhofer, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94551 USA. NR 77 TC 1 Z9 1 U1 2 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI PCCP Phys. Chem. Chem. Phys. PD SEP 15 PY 1999 VL 1 IS 18 BP 4355 EP 4370 DI 10.1039/a903413g PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 236LL UT WOS:000082601000031 ER PT J AU Alatalo, M Weinert, M Watson, RE AF Alatalo, M Weinert, M Watson, RE TI Truncated pseudopotentials for alloy calculations SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS AB In first-principles plane-wave pseudopotential calculations, there is a subtle interplay between the convergence of the wave function and the pseudopotential expansions. Changing the cutoff of the plane-wave expansion often causes a change in the calculated physical quantities. We discuss the origin of this problem and how to ameliorate it by introducing a simple truncation of the pseudopotential in the reciprocal space. By exploiting the arbitrariness inherent in pseudopotentials, the method also provides an extra handle to "tune" the pseudopotentials to yield the best possible agreement with the all-electron results for bulk systems. We demonstrate the benefits of this truncation using Pd as an example and illustrate the results by calculations for some Pd-Al alloys. [S0163-1829(99)00836-X]. C1 Univ Helsinki, Helsinki Inst Phys, FIN-00014 Helsinki, Finland. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Alatalo, M (reprint author), Univ Helsinki, Helsinki Inst Phys, POB 9, FIN-00014 Helsinki, Finland. NR 17 TC 6 Z9 6 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 11 BP 7680 EP 7683 DI 10.1103/PhysRevB.60.7680 PG 4 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600003 ER PT J AU Higuchi, T Tsukamoto, T Watanabe, M Grush, MM Callcott, TA Perera, RC Ederer, DL Tokura, Y Harada, Y Tezuka, Y Shin, S AF Higuchi, T Tsukamoto, T Watanabe, M Grush, MM Callcott, TA Perera, RC Ederer, DL Tokura, Y Harada, Y Tezuka, Y Shin, S TI Crystal-field splitting and the on-site Coulomb energy of LaxSr1-xTiO3 from resonant soft-x-ray emission spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL OXIDES; FLUORESCENCE SPECTROSCOPY; ELECTRONIC-STRUCTURE; SPECTRAL FUNCTIONS; SR1-XLAXTIO3; EXCITATIONS; BAND; SCATTERING; EVOLUTION; SYSTEMS AB Resonant soft-x-ray emission spectroscopy was measured on LaxSr1-xTiO3 (x = 0, 0.05, 0.10) in the Ti 2p energy region. At the Raman scattering of the e(g) resonance, the d-d transition whose Raman shift has an energy value of about 2.3 eV corresponds to the crystal-field splitting. On the other hand, at the t(2g) resonance, the d-d transition whose Raman shift is about 2.2 eV is thought to be the transition reflecting half intra-atomic Coulomb energy. [S0163-1829(99)01232-1]. C1 Univ Tokyo, Dept Appl Phys, Tokyo 1620825, Japan. KEK, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. Univ Tennessee, Knoxville, TN 37996 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Tokyo, Inst Solid State Phys, Tokyo 1068666, Japan. RP Higuchi, T (reprint author), Univ Tokyo, Dept Appl Phys, Tokyo 1620825, Japan. RI Higuchi, Tohru/C-6544-2012; Tokura, Yoshinori/C-7352-2009 NR 25 TC 44 Z9 45 U1 0 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 11 BP 7711 EP 7714 DI 10.1103/PhysRevB.60.7711 PG 4 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600011 ER PT J AU Branz, HM AF Branz, HM TI Hydrogen diffusion and mobile hydrogen in amorphous silicon SO PHYSICAL REVIEW B LA English DT Article ID A-SI-H; CRYSTALLINE SILICON; MECHANISM; MOTION AB Diffusion phenomena in hydrogenated amorphous silicon (a-Si:H) are modeled assuming that mobile H excited from Si-H bonds normally annihilates at dangling-bond defects, as in the "H collision" model of light-induced metastability. This diffusion model explains the long-standing puzzle of the doping dependence of the hydrogen diffusion coefficient DH It also yields the magnitudes of the DH Arrhenius prefactors in doped and undoped a-Si:H. Mobile H diffuses over an energy barrier of about 0.3 eV; at room temperature, its diffusion rate is slightly greater than that of H in crystalline Si. [S0163-1829(99)02536-9]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Branz, HM (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 27 TC 36 Z9 36 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 11 BP 7725 EP 7727 DI 10.1103/PhysRevB.60.7725 PG 3 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600015 ER PT J AU Lyo, SK AF Lyo, SK TI Magnetic-field-induced V-shaped quantized conductance staircase in a double-layer quantum point contact SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL ELECTRON GASES; FERMI SURFACES; WELLS; MASS AB We show that the low-temperature conductance (G) of a quantum point contact consisting of ballistic tunnel-coupled double-layer quantum-well wires is modulated by an in-layer magnetic field B due to the anticrossing. B creates a V-shaped quantum staircase for G, causing it to decrease in steps of 2e(2)/h to a minimum and then increase to a maximum, where G may saturate or decrease again at higher B's. Relevance of the result to recent data is discussed. [S0163-1829(99)14935-X]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lyo, SK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 8 Z9 8 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 11 BP 7732 EP 7735 DI 10.1103/PhysRevB.60.7732 PG 4 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600017 ER PT J AU Levin, EM Pecharsky, VK Gschneidner, KA AF Levin, EM Pecharsky, VK Gschneidner, KA TI Magnetic-field and temperature dependencies of the electrical resistance near the magnetic and crystallographic first-order phase transition of Gd-5(Si2Ge2) SO PHYSICAL REVIEW B LA English DT Article ID GIANT MAGNETORESISTANCE; GD-5(SI1.8GE2.2) AB The magnetic field (0 to 4 T) and temperature (5 to 320 K) dependencies of the electrical resistance of Gd-5(Si2Ge2) have been measured. Upon heating in zero-magnetic field Gd-5(Si2Ge2) undergoes a simultaneous magnetic and crystallographic phase transition at about 276 K. The electrical resistance of Gd-5(Si2Ge2) changes drastically and has significant temperature and magnetic-field hystereses. The magnetoresistance has a negative peak of -26% between 274 and 295 K in a 4 T magnetic field, which is associated with the transition from the low-temperature, low-resistance ferromagnetic orthorhombic to the high-temperature, high-resistance paramagnetic monoclinic phase. The increase of the total resistance upon transformation from the magnetically ordered orthorhombic to magnetically disordered monoclinic phase correlates with the differences between the two crystallographic modifications of Gd-5(Si2Ge2) The behavior of the electrical resistance as a function of magnetic field between 262 and 282 K shows the presence of temperature-dependent critical magnetic fields, which can reversibly transform both the magnetic and crystal structures of the material. The magnetic phase diagram obtained from the magnetic-field and temperature dependencies of the electrical resistance of Gd-5(Si2Ge2) is proposed. [S0163-1829(99)06835-6]. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Pecharsky, VK (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. EM vitkp@ameslab.gov NR 10 TC 128 Z9 130 U1 5 U2 16 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 SEP 15 PY 1999 VL 60 IS 11 BP 7993 EP 7997 DI 10.1103/PhysRevB.60.7993 PG 5 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600060 ER PT J AU Yatskar, A Mielke, CH Canfield, PC Lacerda, AH Beyermann, WP AF Yatskar, A Mielke, CH Canfield, PC Lacerda, AH Beyermann, WP TI Magnetotransport in the heavy-fermion system YbNi2B2C SO PHYSICAL REVIEW B LA English DT Article ID MAGNETORESISTANCE; SUPERCONDUCTIVITY; BEHAVIOR AB We have measured the high field transverse magnetoresistance and magnetization on single crystalline samples of YbNi2B2C with the applied magnetic field both parallel and perpendicular to the c axis of the tetragonal crystal structure. At high temperatures, the magnetoresistance is negative with a magnitude that increases as the temperature is lowered. A scaling analysis of the data for H perpendicular to c finds a characteristic energy that is similar to 20 K at low temperatures, which is a factor of 2 larger than the Kondo temperature determined from thermodynamic measurements, and it increases linearly with the temperature. Even though the magnetoresistance for H parallel to c is also negative, the data do not scale. At low temperatures, the magnetoresistance is very anisotropic. In the Fermi-liquid regime below similar to 1.6 K, the resistivity has a temperature-independent contribution due to ligand and/or Kondo-hole disorder and a term from electron-electron scattering that goes like T-2. For H perpendicular to c, the residual resistivity and the T-2 coefficient are field dependent. Both the high- and low-temperature data are compared to various theoretical calculations. [S0163-1829(99)14631-9]. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Iowa State Univ, Ames, IA 50011 USA. Ames Lab, Ames, IA 50011 USA. RP Yatskar, A (reprint author), Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. RI Canfield, Paul/H-2698-2014; Mielke, Charles/S-6827-2016 OI Mielke, Charles/0000-0002-2096-5411 NR 16 TC 10 Z9 10 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 11 BP 8012 EP 8018 DI 10.1103/PhysRevB.60.8012 PG 7 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600062 ER PT J AU Chen, KR King, TC Hes, JH Leboeuf, JN Geohegan, DB Wood, RF Puretzky, AA Donato, JM AF Chen, KR King, TC Hes, JH Leboeuf, JN Geohegan, DB Wood, RF Puretzky, AA Donato, JM TI Theory and numerical modeling of the accelerated expansion of laser-ablated materials near a solid surface SO PHYSICAL REVIEW B LA English DT Article ID KNUDSEN-LAYER FORMATION; PLUME PROPAGATION; DYNAMICS; VAPORIZATION; MECHANISMS; DEPOSITION; SI AB A self-similar theory and numerical hydrodynamic modeling is developed to investigate the effects of dynamic source and partial ionization on the acceleration of the unsteady expansion of laser-ablated material near a solid target surface. The dynamic source effect accelerates the expansion in the direction perpendicular to the target surface, while the dynamic partial ionization effect accelerates the expansion in all directions. The vaporized material during laser ablation provides a nonadiabatic dynamic source at the target surface into the unsteady expanding fluid. For studying the dynamic source effect, the self-similar theory begins with an assumed profile of plume velocity, u = v/v(m) = alpha + (1 - alpha)xi, where v(m) is the maximum expansion velocity, alpha is a constant, and xi = x/v(m)t. The resultant profiles of plume density and plume temperature are derived. The relations obtained from the conservations of mass, momentum, and energy, respectively, all show that the maximum expansion Velocity is inversely proportional to alpha, where 1 - alpha is the slope of plume velocity profile. The numerical hydrodynamic simulation is performed with the Rusanov method and the Newton Raphson method. The profiles and scalings obtained from numerical hydrodynamic modeling are in good agreement with the theory. The dynamic partial ionization requires ionization energy from the heat at the expansion front, and thus reduces the increase of front temperature. The reduction of thermal motion would increase the flow velocity to conserve the momentum. This dynamic partial ionization effect is studied with the numerical hydrodynamic simulation including the Saha equation. With these effects, alpha is reduced from its value of conventional free expansion. This reduction on alpha increases the flow velocity slope, decreases the flow velocity near the surface, and reduces the thermal motion of plume, such that the maximum expansion velocity is significantly increased over that found from conventional models. The result may provide an explanation for experimental observations of high-expansion front velocities even at low-laser fluence. [S0163-1829(99)08835-9]. C1 Natl Cheng Kung Univ, Dept Phys, Tainan 701, Taiwan. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Sci Applicat Int Corp, Oak Ridge, TN 37831 USA. RP Chen, KR (reprint author), Natl Cheng Kung Univ, Dept Phys, Tainan 701, Taiwan. RI Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013 OI Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139 NR 35 TC 37 Z9 38 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 11 BP 8373 EP 8382 DI 10.1103/PhysRevB.60.8373 PG 10 WC Physics, Condensed Matter SC Physics GA 244VC UT WOS:000083070600108 ER PT J AU Lyman, PF Marasco, DL Walko, DA Bedzyk, MJ AF Lyman, PF Marasco, DL Walko, DA Bedzyk, MJ TI Multiple bonding configurations for Te adsorbed on the Ge(001) surface SO PHYSICAL REVIEW B LA English DT Article ID TERMINATED SI(100) SURFACE; X-RAY-DIFFRACTION; SI(001) SURFACE; MEDIATED EPITAXY; FINE-STRUCTURE; CORE-LEVEL; ADSORPTION; GROWTH; GE; RESTORATION AB Using high-resolution x-ray standing waves and low-energy electron diffraction, the structure of Te adsorbed on Ge(001) was studied. A coverage-dependent structural rearrangement was observed between Te coverages of 1 and 0.5 monolayer (ML). At Te coverages near 1 ML, Te was found to adsorb in a bridge site, as expected. However, at Te coverages near 0.5 ML, a structure unanticipated for Group VI/Group N adsorption was discovered. Te-Ge heterodimers were formed with an average valency of 5, allowing them to satisfy all surface dangling bonds. The results help explain the efficacy of Te as a surfactant in epitaxial growth of Ge/Si(001). C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA. RP Bedzyk, MJ (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. EM bedzyk@nwu.edu RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 42 TC 15 Z9 15 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 12 BP 8704 EP 8712 DI 10.1103/PhysRevB.60.8704 PG 9 WC Physics, Condensed Matter SC Physics GA 241EB UT WOS:000082868800052 ER PT J AU Zhang, B Brooks, J Wang, Z Simmons, J Reno, J Lumpkin, N O'Brien, JL Clark, R AF Zhang, B Brooks, J Wang, Z Simmons, J Reno, J Lumpkin, N O'Brien, JL Clark, R TI In-plane magnetic-field effect on transport properties of the chiral edge state in a quasi-three-dimensional quantum well structure SO PHYSICAL REVIEW B LA English DT Article ID SURFACE-STATES; HALL AB The transport properties of a quasi-three-dimensional, 200-layer quantum-well structure are investigated at integer filling in the quantum Hall state, concomitant with the chiral edge state condition. We find that the transverse magnetoresistance R-xx, the Hall resistance R-xy, and the vertical resistance R-zz all follow a similar behavior with both temperature and in-plane magnetic field. A general characteristic of the influence of increasing in-plane held B-in is that the quantization condition first improves, but above a critical value B-in(C), the quantization is systematically removed. We consider the interplay of the chiral edge state transport and the bulk (quantum Hall) transport properties. This mechanism may arise from the competition of the cyclotron energy with the superlattice band-structure energies. A comparison of the results with existing theories of the chiral edge state transport with in-plane field is also discussed. C1 Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New S Wales, Natl Pulsed Magnet Lab, Sydney, NSW 2052, Australia. Univ New S Wales, SemiConductor Nanofabricat Facil Sch Phys, Sydney, NSW 2052, Australia. RP Zhang, B (reprint author), Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. RI O'Brien, Jeremy/A-6290-2008; OI O'Brien, Jeremy/0000-0002-3576-8285 NR 13 TC 11 Z9 11 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 12 BP 8743 EP 8747 DI 10.1103/PhysRevB.60.8743 PG 5 WC Physics, Condensed Matter SC Physics GA 241EB UT WOS:000082868800057 ER PT J AU Kim, K Ozolins, V Zunger, A AF Kim, K Ozolins, V Zunger, A TI Instability of the high-pressure CsCl structure in most III-V semiconductors SO PHYSICAL REVIEW B LA English DT Article ID ZINCBLENDE SEMICONDUCTORS; PHASE-TRANSITIONS; SOLIDS; SYSTEMATICS; STABILITY; GAAS; INSB; GAP AB Using the density-functional linear response method, we study dynamical instabilities of the high-pressure CsCl phase in III-V semiconductors. For InSb, we find no phonon instability that could prevent the CsCl phase from forming, consistent with the experimental observation. In contrast, for the more ionic GaP, GaAs, InP, and InAs, we find that, while statically stable, the CsCl phase is dynamically unstable at high pressures with respect to transverse-acoustic [xi xi 0] phonons. Analysis of the soft normal modes via "isotropy subgroup" suggests two candidate structures that will replace CsCl structure at high pressure: the tP4 (B10) InBi type and the oP4 (B19) AuCd type. Experimental examination of these predictions is called for. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kim, K (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Ozolins, Vidvuds/D-4578-2009; Zunger, Alex/A-6733-2013 NR 30 TC 19 Z9 19 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 12 BP R8449 EP R8452 DI 10.1103/PhysRevB.60.R8449 PG 4 WC Physics, Condensed Matter SC Physics GA 241EB UT WOS:000082868800009 ER PT J AU Melik-Alaverdian, V Bonesteel, NE Ortiz, G AF Melik-Alaverdian, V Bonesteel, NE Ortiz, G TI Skyrmion physics beyond the lowest Landau-level approximation SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM HALL FERROMAGNETS; MONTE-CARLO; NU=1; EXCITATIONS; INTEGER; LIQUID; FIELD; WELLS; GAP AB The effects of Landau-level mixing and finite thickness of the two-dimensional electron gas on the relative stability of Skyrmion and single spin-flip excitations at Landau-level filling factor nu = I have been investigated. Landau-level mixing: is studied by fixed-phase diffusion Monte Carlo, and finite thickness is included by modifying the effective Coulomb interaction. Both Landau-level mixing and finite thickness lower Skyrmion excitation energies and favor Skyrmions with fewer spin flips. However, the two effects do not work "coherently." When finite thickness is included, the effect of Landau-level mixing is strongly suppressed. C1 Univ Rhode Isl, Dept Phys, Kingston, RI 02881 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32310 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Melik-Alaverdian, V (reprint author), Univ Rhode Isl, Dept Phys, Kingston, RI 02881 USA. NR 16 TC 14 Z9 14 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1999 VL 60 IS 12 BP R8501 EP R8504 DI 10.1103/PhysRevB.60.R8501 PG 4 WC Physics, Condensed Matter SC Physics GA 241EB UT WOS:000082868800022 ER PT J AU Vobornik, I Perfetti, L Zacchigna, M Grioni, M Margaritondo, G Mesot, J Medarde, M Lacorre, P AF Vobornik, I Perfetti, L Zacchigna, M Grioni, M Margaritondo, G Mesot, J Medarde, M Lacorre, P TI Electronic-structure evolution through the metal-insulator transition in RNiO3 SO PHYSICAL REVIEW B LA English DT Article ID PEROVSKITES; PRNIO3; PHOTOEMISSION; SPECTROSCOPY; NDNIO3; STATE; GAP; ND AB We performed a photoemission investigation of the electronic structure of PrNiO3 and NdNiO3 through the first order (paramagnetic) metal to (antiferromagnetic) insulator transition. Surprisingly, the data reveal a temperature-dependent loss of spectral weight near the chemical potential, which extends well below the coincident metal-insulator (T-MI) and magnetic (T-Neel) transition temperatures. This is in contrast with the behavior in SmNiO3 and EuNiO3, where the two transitions are separate. The spectral properties clearly indicate two distinct regimes for RNiO3 with T-MI = T-Neel and T-MI > T-Neel. C1 Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Maine, UPRES A CNRS 6010, Lab Fluorures, F-72017 Le Mans 9, France. RP Vobornik, I (reprint author), Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. RI Margaritondo, Giorgio/B-1367-2008; Vobornik, Ivana/B-9463-2015 NR 24 TC 34 Z9 34 U1 3 U2 35 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 SEP 15 PY 1999 VL 60 IS 12 BP R8426 EP R8429 DI 10.1103/PhysRevB.60.R8426 PG 4 WC Physics, Condensed Matter SC Physics GA 241EB UT WOS:000082868800003 ER PT J AU Anninos, P McKinney, J AF Anninos, P McKinney, J TI Relativistic hydrodynamics of cosmological sheets SO PHYSICAL REVIEW D LA English DT Article ID FRIEDMAN-LEMAITRE COSMOLOGIES; GRAVITATIONAL-INSTABILITY; ZELDOVICH APPROXIMATION; LAGRANGIAN THEORY; GENERAL-RELATIVITY; UNIVERSE; FRAGMENTATION; PERTURBATIONS; PANCAKES; GALAXIES AB We have extended previous numerical calculations of Newtonian cosmological sheets to include self-consistent interactions with the background metric by solving the complete Einstein field equations together with the relativistic perfect fluid hydrodynamics equations. The initial data are parametrized and constructed using the gauge invariant perturbation formalism to specify the free conformal variables for the constraints. Numerical evolutions of initially horizon scale fluctuations are compared with results from perturbation theory and the Zel'dovich solution for a range of gravitational field strengths, and we discuss the nonlinear hydrodynamic, optical, and geometric characteristics of the sheet structures. [S0556-2821(99)00218-0]. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Illinois, Dept Phys, Champaign, IL 61801 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 25 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 SEP 15 PY 1999 VL 60 IS 6 AR 064011 DI 10.1103/PhysRevD.60.064011 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 238VK UT WOS:000082734800035 ER PT J AU Chung, DJH Kolb, DW Riotto, A AF Chung, DJH Kolb, DW Riotto, A TI Production of massive particles during reheating SO PHYSICAL REVIEW D LA English DT Article ID ENERGY COSMIC-RAYS; BARYOGENESIS; UNIVERSE; MATTER; DECAY AB What is commonly called the reheat temperature, T-RH, is not the maximum temperature obtained after inflation. The maximum temperature is, in fact, much larger than T-RH. As an application of this we consider the production of massive stable dark-matter particles of mass M-X during reheating, and show that their abundance is suppressed as a power of T-RH/M-X rather than exp(-M-X/T-RH). We find that particles of mass as large as 2x10(3) times the reheat temperature may be produced in interesting abundance. In addition to dark matter, our analysis is relevant for baryogenesis if the baryon asymmetry is produced by the baryon (or lepton) number violating decays of superheavy bosons, and also for relic ultra-high energy cosmic rays if decays of superheavy particles are responsible for the highest energy cosmic rays. [S0556-2821(99)07918-7]. C1 Fermi Natl Accelerator Lab, NASA Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Chung, DJH (reprint author), Fermi Natl Accelerator Lab, NASA Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. EM djchung@theory.uchicago.edu; rocky@rigoletto.fnal.gov; riotto@nxth03.cern.ch NR 18 TC 169 Z9 169 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1999 VL 60 IS 6 AR 063504 DI 10.1103/PhysRevD.60.063504 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 238VK UT WOS:000082734800012 ER PT J AU Timm, DE Mueller, HA Bhanumoorthy, P Harp, JM Bunick, GJ AF Timm, DE Mueller, HA Bhanumoorthy, P Harp, JM Bunick, GJ TI Crystal structure and mechanism of a carbon-carbon bond hydrolase SO STRUCTURE WITH FOLDING & DESIGN LA English DT Article DE amino acid metabolism; catalytic triad; hereditary tyrosinemia; hydrolase; metalloenzyme; X-ray crystallography ID TRANSITION-STATE ANALOG; TYROSINEMIA TYPE-I; HEREDITARY TYROSINEMIA; ISOMORPHOUS REPLACEMENT; VENOM PHOSPHOLIPASE-A2; CATALYTIC MECHANISM; DIFFRACTION DATA; FUMARYLACETOACETATE; FOLD; GENE AB Background: Fumarylacetoacetate hydrolase (FAH) catalyzes the final step of tyrosine and phenylalanine catabolism, the hydrolytic cleavage of a carbon-carbon bond in fumarylacetoacetate, to yield fumarate and acetoacetate, FAH has no known sequence homologs and functions by an unknown mechanism, Carbon-carbon hydrolysis reactions are essential for the human metabolism of aromatic amino acids. FAH deficiency causes the fatal metabolic disease hereditary tyrosinemia type I. Carbon-carbon bond hydrolysis is also important in the microbial metabolism of aromatic compounds as part of the global carbon cycle. Results: The FAH crystal structure has been determined by rapid, automated analysis of multiwavelength anomalous diffraction data. The FAH polypeptide folds into a 120-residue N-terminal domain and a 300-residue C-terminal domain. The C-terminal domain defines an unusual beta-strand topology and a novel 'mixed beta-sandwich roll' structure. The structure of FAH complexed with its physiological products was also determined, This structure reveals fumarate binding near the entrance to the active site and acetoacetate binding to an octahedrally coordinated calcium ion located in close proximity to a Glu-His dyad. Conclusions: FAH represents the first structure of a hydrolase that acts specifically on carbon-carbon bonds. FAH also defines a new class of metalloenzymes characterized by a unique alpha/beta fold. A mechanism involving a Glu-His-water catalytic triad is suggested based on structural observations, sequence conservation and mutational analysis. The histidine imidazole group is proposed to function as a general base. The Ca2+ is proposed to function in binding substrate, activating the nucleophile and stabilizing a carbanion leaving group. An oxyanion hole formed from sidechains is proposed to stabilize a tetrahedral alkoxide transition state. The proton transferred to the carbanion leaving group is proposed to originate from a lysine sidechain, The results also reveal the molecular basis for mutations causing the hereditary tyrosinemia type I. C1 Indiana Univ, Sch Med, Dept Biochem & Mol Biol, Indianapolis, IN 46202 USA. Univ Tennessee, Oak Ridge Grad Sch Biomed Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Timm, DE (reprint author), Indiana Univ, Sch Med, Dept Biochem & Mol Biol, 635 Barnhill Dr, Indianapolis, IN 46202 USA. FU NIDDK NIH HHS [DK54738]; NIGMS NIH HHS [GM29818] NR 40 TC 49 Z9 51 U1 1 U2 4 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0969-2126 J9 STRUCT FOLD DES JI Struct. Fold. Des. PD SEP 15 PY 1999 VL 7 IS 9 BP 1023 EP 1033 DI 10.1016/S0969-2126(99)80170-1 PG 11 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 238BL UT WOS:000082691000005 PM 10508789 ER PT J AU Abdallah, MA Wolff, W Wolf, HE Cocke, CL Stockli, M AF Abdallah, MA Wolff, W Wolf, HE Cocke, CL Stockli, M TI Low-velocity ionization in asymmetric systems: a comparative study of the He+-Ne and Ne+-He cases SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ION-ATOM COLLISIONS; LOW-KEV ENERGIES; RARE-GAS ATOMS; AR; KR; XE AB Single target ionization was investigated in the asymmetric collision systems He+-Ne and Ne+-He at projectile velocities of 0.25, 0.35 and 0.5 au employing electron and recoil momentum imaging techniques. At the two lower velocities the recoil transverse momentum distributions were found to be donut shaped. In addition, a concentric double-donut was observed in the He+-Ne system at 0.25 au. At 0.35 and 0.5 au the electron distributions are characterized by a pronounced asymmetry with respect to the beam axis, an asymmetry which is almost completely reversed by exchanging projectile and target. This latter finding is interpreted as confirmation of the molecular nature of the ionization process at these velocities. C1 Univ Fed Rio de Janeiro, Inst Fis, Rio De Janeiro, Brazil. Kansas State Univ, JR Macdonald Lab, Manhattan, KS 66506 USA. RP Abdallah, MA (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Wolff, Wania/O-5556-2015 NR 8 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 1999 VL 32 IS 17 BP 4237 EP 4247 DI 10.1088/0953-4075/32/17/308 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 238WC UT WOS:000082736600013 ER PT J AU Jimenez-Mier, J Schaphorst, S Caldwell, CD Krause, MO AF Jimenez-Mier, J Schaphorst, S Caldwell, CD Krause, MO TI Auger decay of the 1s -> np (n=2-6) resonances in beryllium SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID IONS; AUTOIONIZATION; ENHANCEMENT; MAGNESIUM; SPECTRA AB We studied the decay channels of the photon-excited 1s2s(2)np(P-1) (n = 2-6) resonances in Be. We confirmed the predominant decay modes for n = 2, 3 found previously by Caldwell et al (1990 Phys. Rev. A 41 542). The decay modes of the higher resonances are admixtures of np' ionic states, with n > 2. Evidence for strong shake up and shake down was found. Very good agreement was found with the 'shake' model, which predicts the relative intensities of the exit channels in terms of the projections of the excited electron wavefunctions onto the ionic electron wavefunctions. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jimenez-Mier, J (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. RI Jimenez-Mier, Jose/A-5081-2009 OI Jimenez-Mier, Jose/0000-0002-5939-9568 NR 11 TC 8 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 1999 VL 32 IS 17 BP 4301 EP 4307 DI 10.1088/0953-4075/32/17/313 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 238WC UT WOS:000082736600018 ER PT J AU Huang, WX Helvenston, M Casson, JL Wang, R Bardeau, JF Lee, YW Johal, MS Swanson, BI Robinson, JM Li, DQ AF Huang, WX Helvenston, M Casson, JL Wang, R Bardeau, JF Lee, YW Johal, MS Swanson, BI Robinson, JM Li, DQ TI Synthesis, characterization, and NLO properties of a phenothiazine-stilbazole monolayer SO LANGMUIR LA English DT Article ID ION-EXCHANGE PROCESSES; 2ND-HARMONIC GENERATION; ELECTRON-TRANSFER; MOLECULAR-ORIENTATION; THIN-FILMS; SURFACES; MULTILAYERS; SEPARATION; ASSEMBLIES; SYSTEMS AB 4-(trans-4-(4-(10-phenothiazinyl)butyramido)styryl)pyridine (PBSP) has been synthesized and covalently bound to a coupling layer of (p-(chloromethyl)phenyl)trichlorosilane (CPTS) on a quartz substrate to produce a polar-ordered thin film. The addition of the PBSP molecules on the coupling layer was monitored by FTIR spectroscopy, UV-visible spectroscopy, AFM, and second harmonic generation (SHG). The observation of an amine band and strong methylene bands in the infrared spectra indicates the presence of the PBSP layer. The UV-visible spectrum shows a red shift in the charge-transfer band, consistent with the addition of the PBSP and quaternization of the pyridyl group. AFM shows that there is an incomplete coverage of the PBSP layer on the coupling layer. The nonlinear optical properties of the PBSP monolayers were measured by SHG. The second harmonic (SH) signal increased by 1 order of magnitude after the addition of the PBSP chromophore layer. The dependence of the SH intensity on incident angle and input polarization was modeled. The average molecular orientation angle of the choromophore was determined to be 55 degrees, and a value of chi(zzz) = chi(zxx) = 2.8 x 10(-8) esu was calculated. C1 New Mexico Highlands Univ, Dept Chem, Las Vegas, NM 87701 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Helvenston, M (reprint author), New Mexico Highlands Univ, Dept Chem, Las Vegas, NM 87701 USA. NR 36 TC 20 Z9 20 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 14 PY 1999 VL 15 IS 19 BP 6510 EP 6514 DI 10.1021/la990237c PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 236RY UT WOS:000082618800052 ER PT J AU Gilligan, DM Lozovatsky, L Gwynn, B Brugnara, C Mohandas, N Peters, LL AF Gilligan, DM Lozovatsky, L Gwynn, B Brugnara, C Mohandas, N Peters, LL TI Targeted disruption of the beta adducin gene (Add2) causes red blood cell spherocytosis in mice SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID PROTEIN-KINASE-C; HUMAN ALPHA-ADDUCIN; ERYTHROCYTE ADDUCIN; ACTIN-FILAMENTS; ORGANIZATION; BINDING; PHOSPHORYLATION; MEMBRANE; DOMAIN AB Adducins are a family of cytoskeleton proteins encoded by three genes (alpha, beta, gamma), In a comprehensive assay of gene expression, we show the ubiquitous expression of alpha- and gamma-adducins in contrast to the restricted expression of beta-adducin, beta-adducin is expressed at high levels in brain and hematopoietic tissues (bone marrow in humans, spleen in mice). To elucidate adducin's role in vivo, we created beta-adducin null mice by gene targeting, deleting exons 9-13, A 55-kDa chimeric polypeptide is produced from the first eight exons of beta-adducin and part of the neo cassette in spleen but is not detected in peripheral RBCs or brain. beta-adducin null RBCs are osmotically fragile, spherocytic, and dehydrated compared with the wild type, resembling RBCs from patients with hereditary spherocytosis, The lack of beta-adducin in RBCs leads to decreased membrane incorporation of alpha-adducin (30% of normal) and unexpectedly promotes a 5-fold increase in gamma-adducin incorporation into the RBC membrane skeleton. This study demonstrates adducin's importance to RBC membrane stability in vivo. C1 Yale Univ, Sch Med, Dept Internal Med Hematol, New Haven, CT 06510 USA. Jackson Lab, Bar Harbor, ME 04609 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Childrens Hosp, Dept Lab Med, Boston, MA 02115 USA. RP Gilligan, DM (reprint author), Yale Univ, Sch Med, Dept Internal Med Hematol, WWW 403,333 Cedar St, New Haven, CT 06510 USA. RI Brugnara, Carlo/A-8041-2010 OI Brugnara, Carlo/0000-0001-8192-8713 FU NHLBI NIH HHS [R01 HL055321, HL55321]; NIDDK NIH HHS [DK02070, DK26263, R01 DK026263, R37 DK026263] NR 23 TC 82 Z9 83 U1 1 U2 5 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 14 PY 1999 VL 96 IS 19 BP 10717 EP 10722 DI 10.1073/pnas.96.19.10717 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 235ZQ UT WOS:000082574100038 PM 10485892 ER PT J AU Leitner, T Albert, J AF Leitner, T Albert, J TI The molecular clock of HIV-1 unveiled through analysis of a known transmission history SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID VIRUS TYPE-1 EVOLUTION; NUCLEOTIDE SUBSTITUTIONS; IN-VIVO; GENE; POPULATIONS; DNA; SEQUENCES; INFECTION; THERAPY; NUMBER AB Detailed knowledge about the rate and mode of the genetic variation is vital for understanding how HIV-1 induces disease and develops resistance as well as for studies on the molecular epidemiology and origin of the virus. To unveil the molecular clock of HIV-1 we analyzed a unique set of viruses from a known transmission history with separation times between samples of up to 25 years. The env V3 and p17gag regions of the genome were sequenced, and genetic distances were estimated by using the true tree and a nucleotide substitution model based on a general reversible Markov process with a gamma distribution to account for differences in substitution rates among sites. Linear regression analysis showed that separation times were significantly correlated with synonymous as well as nonsynonymous nucleotide distances in both V3 and p17, giving strong support for the existence of a molecular clock. The estimated rate of nucleotide substitution was 6.7 +/- 2.1 x 10(-3) substitutions/site per year in V3 and 2.7 +/- 0.5 x 10(-3) in p17, Importantly, the regression analyses showed that there was a significant genetic distance at zero divergence times, This pretransmission interval exists because the ramifications in the phylogenetic trees do not correspond to time of transmission, but rather to the coalescence time of the most recent common ancestor of the viruses carried by the transmitter and the recipient. Simulation experiments showed that neither the V3 nor the p17 clocks were overdispersed, which indicates that the introduction of nucleotide substitutions can be described adequately by a simple stochastic Poisson process. C1 Univ Calif Los Alamos Natl Lab, Grp T10, Los Alamos, NM 87545 USA. Swedish Inst Infect Dis Control, Dept Clin Virol, SE-17182 Solna, Sweden. RP Leitner, T (reprint author), Univ Calif Los Alamos Natl Lab, Grp T10, MS K7103, Los Alamos, NM 87545 USA. FU NIAID NIH HHS [K01 AI070001] NR 32 TC 104 Z9 104 U1 2 U2 9 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 SEP 14 PY 1999 VL 96 IS 19 BP 10752 EP 10757 DI 10.1073/pnas.96.19.10752 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 235ZQ UT WOS:000082574100044 PM 10485898 ER PT J AU Stevens, KT Garces, NY Halliburton, LE Yan, M Zaitseva, NP DeYoreo, JJ Catella, GC Luken, JR AF Stevens, KT Garces, NY Halliburton, LE Yan, M Zaitseva, NP DeYoreo, JJ Catella, GC Luken, JR TI Identification of the intrinsic self-trapped hole center in KD2PO4 SO APPLIED PHYSICS LETTERS LA English DT Article ID POTASSIUM DIHYDROGEN PHOSPHATE; ELECTRON-SPIN-RESONANCE; FREQUENCY-CONVERSION; ABSORPTION; CRYSTALS; KH2PO4; DKDP; KDP AB The intrinsic "self-trapped" hole center in KD2PO4 crystals has been identified using electron paramagnetic resonance and electron-nuclear double resonance. These defects, labeled [D2PO4](o) centers, can be formed at 77 K by irradiating with either 60 kV x rays or the fourth harmonic (266 nm) of a pulsed Nd:YAG laser. The hole is equally shared by two adjacent oxygen ions, and hyperfine interactions with one phosphorus and two equivalent deuterons are observed. The sample used in this investigation was approximately 80% deuterated, thus both [D2PO4](o) and [HDPO4](o) centers were detected, with the former being dominant. These intrinsic self-trapped hole centers are of interest because of their potential role in the transient optical absorption produced in KD2PO4 crystals at room temperature by intense 266 nm laser pulses. (C) 1999 American Institute of Physics. [S0003-6951(99)01837-9]. C1 W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Cleveland Crystals Inc, Highland Hts, OH 44143 USA. RP Stevens, KT (reprint author), W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. NR 12 TC 28 Z9 29 U1 2 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 1999 VL 75 IS 11 BP 1503 EP 1505 DI 10.1063/1.124736 PG 3 WC Physics, Applied SC Physics GA 233RU UT WOS:000082441000005 ER PT J AU Ajgaonkar, M Zhang, Y Grebel, H White, CW AF Ajgaonkar, M Zhang, Y Grebel, H White, CW TI Nonlinear optical properties of a coherent array of submicron SiO2 spheres (opal) embedded with Si nanoparticles SO APPLIED PHYSICS LETTERS LA English DT Article AB The optical properties of a coherent array of 300 nm SiO2 spheres implanted with Si ions were shown to change nonlinearly with light intensity. These changes have been attributed to transverse confinement of the optical beam within the opal structure. (C) 1999 American Institute of Physics. [S0003-6951(99)03237-4]. C1 New Jersey Inst Technol, Dept Elect & Comp Engn, Nonlinear Nanostruct Lab, Newark, NJ 07102 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ajgaonkar, M (reprint author), New Jersey Inst Technol, Dept Elect & Comp Engn, Nonlinear Nanostruct Lab, Newark, NJ 07102 USA. NR 6 TC 29 Z9 30 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 1999 VL 75 IS 11 BP 1532 EP 1534 DI 10.1063/1.124746 PG 3 WC Physics, Applied SC Physics GA 233RU UT WOS:000082441000015 ER PT J AU Lee, SH Cheong, HM Tracy, CE Mascarenhas, A Czanderna, AW Deb, SK AF Lee, SH Cheong, HM Tracy, CE Mascarenhas, A Czanderna, AW Deb, SK TI Electrochromic coloration efficiency of a-WO3-y thin films as a function of oxygen deficiency SO APPLIED PHYSICS LETTERS LA English DT Article ID TUNGSTEN-OXIDE; WO3 FILMS; CENTERS AB We report on how electrochromic coloration is affected by oxygen deficient stoichiometries in sputtered amorphous tungsten oxide (a-WO3-y) films. The electrochromic coloration efficiency increases with increasing oxygen deficiency in (a-WO3-y) films. No coloration is observed in nearly stoichiometric WO3 films. Raman spectroscopic studies reveal that the number of W5+ states generated with lithium insertion increases with the oxygen deficiency. Furthermore, there are no Raman peaks resulting from W5+ states in lithiated a-WO3-y films with near perfect stoichiometry, which is consistent with the absence of electrochromic coloration in those films. We conclude that the coloration efficiency of a-WO3-y films depends on the number of the W5+ states generated by lithium insertion and that the oxygen deficiency plays an important role in generating the W5+ states with lithium insertion. (C) 1999 American Institute of Physics. [S0003-6951(99)04637-9]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Lee, SH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Lee, Sehee/A-5989-2011; Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 NR 16 TC 129 Z9 132 U1 5 U2 40 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 1999 VL 75 IS 11 BP 1541 EP 1543 DI 10.1063/1.124782 PG 3 WC Physics, Applied SC Physics GA 233RU UT WOS:000082441000018 ER PT J AU Shan, C AF Shan, C TI An analytical solution for the capture zone of two arbitrarily located wells SO JOURNAL OF HYDROLOGY LA English DT Article DE analytical solution; capture zone; groundwater containment and remediation ID AQUIFER; DESIGN; FLOW AB A capture zone of pumping well(s) in an aquifer with regional groundwater flow has been widely used to help design a pump-and-treat system for groundwater containment and remediation. Based on the theorem of potential and the principle of superposition, an analytical solution is derived in this study to calculate the capture zone for two arbitrarily located wells that pump water from a confined aquifer at an equal flow rate. The general two-well capture zone is composed of two sub-capture zones, one for each well. The shapes of the two sub-capture zones and their relative locations change with variations of the orientation and the separation of the two wells. The solution can be useful in verifying available numerical codes, as well as in solving practical field problems. Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Shan, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. NR 17 TC 34 Z9 34 U1 4 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD SEP 13 PY 1999 VL 222 IS 1-4 BP 123 EP 128 DI 10.1016/S0022-1694(99)00101-8 PG 6 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 238DM UT WOS:000082695700009 ER PT J AU Ping, JL Wang, F Goldman, T AF Ping, JL Wang, F Goldman, T TI Effective baryon-baryon potentials in the quark delocalization and color screening model SO NUCLEAR PHYSICS A LA English DT Article DE hyperon; baryon; potential; scattering; quark ID HYPERON-NUCLEON-INTERACTION; INTERMEDIATE RANGE ATTRACTION; MESON-EXCHANGE MODEL; CLUSTER MODEL; DIBARYON AB The quark delocalization and color screening model is used for a systematic study of the effective potential between baryons in the u, d and s sector. The model is constrained by the properties of baryons and N-N scattering. The effective potentials for the N-N (IJ = 01, 10, 11,00) channels and the N-Lambda and N-Sigma (IJ = 1/2 1, 1/2 0, 3/2 1, 3/2 0) channels fit the N-N, N-Lambda and N-Sigma scattering data reasonably well. This model predicts: there are rather strong effective attractions between some decuplet-baryons; the effective attractions between octet-baryons are usually weak; and the attractions between decuplet- and octet-baryons lie in between. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Nanjing Normal Univ, Dept Phys, Nanjing 210097, Peoples R China. Nanjing Univ, Ctr Theoret Phys, Nanjing 210008, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210008, Peoples R China. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ping, JL (reprint author), Nanjing Normal Univ, Dept Phys, Nanjing 210097, Peoples R China. NR 30 TC 41 Z9 51 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 13 PY 1999 VL 657 IS 1 BP 95 EP 109 DI 10.1016/S0375-9474(99)00321-8 PG 15 WC Physics, Nuclear SC Physics GA 238MB UT WOS:000082713100005 ER PT J AU Veil, JA Daly, JM Johnson, N AF Veil, JA Daly, JM Johnson, N TI EPA speeds regs for offshore synthetic-based mud SO OIL & GAS JOURNAL LA English DT Article C1 Argonne Natl Lab, Water Policy Program, Washington, DC USA. US EPA, Boston, MA USA. US DOE, Off Fossil Energy, Washington, DC USA. RP Veil, JA (reprint author), Argonne Natl Lab, Water Policy Program, Washington, DC USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 USA SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD SEP 13 PY 1999 VL 97 IS 37 BP 78 EP + PG 5 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA 236RR UT WOS:000082612800019 ER PT J AU Bundens, JW Yudenfreund, J Francl, MM AF Bundens, JW Yudenfreund, J Francl, MM TI Transition states for the carboalumination of alkenes and alkynes SO ORGANOMETALLICS LA English DT Article ID MOLECULAR-ORBITAL METHODS; ELECTRON CORRELATION-ENERGY; VALENCE BASIS-SETS; PERTURBATION-THEORY; 2ND-ROW ELEMENTS; ABINITIO MO; MECHANISM; INSERTION; ETHYLENE; HYDROBORATIONS AB Ab initio molecular orbital theory was used to characterize stationary points on the potential energy surface for the carboalumination of alkenes and alkynes. Activation energies and entropies of activation were calculated and found to be in good agreement with experimental values. A pi-complex between the alkyl aluminum and the substrate is a stable precursor to the transition structure. The transition structures are four-centered. Substituent effects on the transition structure geometries are small and predictable, suggesting that standard values for geometrical parameters for this and related reactions are reasonable. The anomalous relative reactivities of substrates can be explained by considering the reaction to essentially be a nucleophilic attack, rather than an electrophilic one. C1 Bryn Mawr Coll, Dept Chem, Bryn Mawr, PA 19010 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Bryn Mawr Coll, Dept Chem, 101 N Merion Ave, Bryn Mawr, PA 19010 USA. NR 60 TC 19 Z9 19 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 EI 1520-6041 J9 ORGANOMETALLICS JI Organometallics PD SEP 13 PY 1999 VL 18 IS 19 BP 3913 EP 3920 DI 10.1021/om990350y PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 239BC UT WOS:000082748100021 ER PT J AU Gaspar, PP Beatty, AM Chen, TQ Haile, T Lei, DQ Winchester, WR Braddock-Wilking, J Rath, NP Klooster, WT Koetzle, TF Mason, SA Albinati, A AF Gaspar, PP Beatty, AM Chen, TQ Haile, T Lei, DQ Winchester, WR Braddock-Wilking, J Rath, NP Klooster, WT Koetzle, TF Mason, SA Albinati, A TI Tris(triisopropylsilyl)silane and the generation of bis (triisopropylsilyl)silylene SO ORGANOMETALLICS LA English DT Article ID ELECTRON-SPIN RESONANCE; TRIPLET SILYLENES; INTERNAL-ROTATION; ALKYL RADICALS; SILICON; DIMETHYLSILYLENE; GERMANIUM; OLEFINS; TIN; ORGANOPOLYSILANES AB Tris(triisopropylsilyl)silane (iPr(3)Si)(3)SiH has been synthesized and studied by X-ray and neutron diffraction. It possesses an unusual structure in which the four silicon atoms are nearly coplanar, angle Si-Si-Si = 118.41(5)degrees. The Si-H distance is found to have a normal value of 1.506(2) Angstrom. Thermal and room-temperature photochemical decomposition of (iPr(3)-Si)(3)SiH leads to the elimination of iPr(3)SiH and the generation of bis(triisopropylsilyl)silylene, [(iPr(3)Si)(2)Si:]. Reactions of(iPr(3)Si)(2)Si: include precedented insertions into H-Si bonds and addition to the pi-bonds of olefins, alkynes, and dienes. Despite theoretical predictions of a triplet ground state for [(iPr(3)Si)(2)Si:], stereospecific addition to cis- and trans-2-butene was observed. C1 Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Missouri, Dept Chem, St Louis, MO 63121 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Univ Milan, Ist Chim Farmaceut, I-20131 Milan, Italy. RP Gaspar, PP (reprint author), Washington Univ, Dept Chem, St Louis, MO 63130 USA. RI mason, sax /E-6738-2011; Albinati, Alberto/I-1262-2015 OI Albinati, Alberto/0000-0002-8779-3327 NR 59 TC 48 Z9 48 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP 13 PY 1999 VL 18 IS 19 BP 3921 EP 3932 DI 10.1021/om990418+ PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 239BC UT WOS:000082748100022 ER PT J AU Brhlik, M Everett, L Kane, GL Lykken, J AF Brhlik, M Everett, L Kane, GL Lykken, J TI Resolution to the supersymmetric CP problem with large soft phases via D-branes SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRIC-DIPOLE MOMENT; STANDARD MODEL; ORBIFOLD COMPACTIFICATIONS; EXPERIMENTAL LIMIT; VIOLATING PHASES; N=1 SUPERGRAVITY; STRING THEORY; BREAKING; NEUTRON; TERMS AB We examine the soft supersymmetry breaking parameters that result from various ways of embedding the standard model (SM) on D-branes within the type I string picture, allowing the parameters to have large CP-violating phases. One embedding naturally provides the relations among soft parameters to satisfy the electron and neutron electric dipole moment constraints even with large phases, while with other embeddings large phases an not allowed. The results generally suggest how low energy data might teach us about Planck scale physics. C1 Univ Michigan, Dept Phys, Randall Lab, Ann Arbor, MI 48109 USA. Fermi Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Brhlik, M (reprint author), Univ Michigan, Dept Phys, Randall Lab, Ann Arbor, MI 48109 USA. NR 46 TC 118 Z9 118 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 13 PY 1999 VL 83 IS 11 BP 2124 EP 2127 DI 10.1103/PhysRevLett.83.2124 PG 4 WC Physics, Multidisciplinary SC Physics GA 234LC UT WOS:000082485300008 ER PT J AU Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bricker, JD Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nauenberg, U Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, AK Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Wu, JY Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bricker, JD Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nauenberg, U Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, AK Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Wu, JY Yamanaka, T Zimmerman, ED CA KTeV Collaboration TI Search for light gluinos via decays containing pi(+) pi(-) or pi(0) from a neutral hadron beam at fermilab SO PHYSICAL REVIEW LETTERS LA English DT Article ID MEDIATED SUPERSYMMETRY-BREAKING; PHOTINOS AB We report on two null searches, one for the spontaneous appearance of pi(+)pi(-) pails, another for a single pi(0), consistent with the decay of a long-lived neutral particle into hadrons and an unseen neutral particle. For the lowest level gluon-gluino bound state, known as the R-0, we exclude the decays R-0 --> pi(+) pi(-) <(gamma)over tilde> and R-0 --> pi(0)<(gamma)over tilde> for the masses of R-0 and <(gamma)over tilde> in the theoretically allowed range. In the most interesting R-0 mass range, less than or equal to 3 GeV/c(2), we exclude R-0 lifetimes from 3 x 10(-10) sec to as high as 10(-3) sec, assuming perturbative QCD production for the R-0. C1 Rutgers State Univ, Piscataway, NJ 08855 USA. Univ Virginia, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. Rice Univ, Houston, TX 77005 USA. Osaka Univ, Toyonaka, Osaka 560, Japan. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Arizona, Tucson, AZ 85721 USA. RP Lath, A (reprint author), Rutgers State Univ, Piscataway, NJ 08855 USA. RI Albuquerque, Ivone/H-4645-2012 OI Albuquerque, Ivone/0000-0001-7328-0136 NR 14 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 13 PY 1999 VL 83 IS 11 BP 2128 EP 2132 DI 10.1103/PhysRevLett.83.2128 PG 5 WC Physics, Multidisciplinary SC Physics GA 234LC UT WOS:000082485300009 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Cropp, R Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Gianetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Heiss, A Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martignon, G Martin, A Matthews, JAJ Mazzanti, P McFarland, K McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Musy, M Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pompos, A Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Volobouev, I Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, F Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zuccelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Cropp, R Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Gianetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Heiss, A Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martignon, G Martin, A Matthews, JAJ Mazzanti, P McFarland, K McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Musy, M Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pompos, A Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Volobouev, I Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, F Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zuccelli, S TI Search for R-parity violating supersymmetry using like-sign dielectrons in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMILAB TEVATRON; (P)OVER-BAR-P COLLISIONS; ORDINARY ENERGIES; PAIR PRODUCTION; TOP-QUARK; HERA; LIGHT; PHENOMENOLOGY; COLLIDERS; EVENTS AB We present a search for like-sign dielectron plus multijet events using 107 pb(-1) of data in p (p) over bar collisions at root s = 1.8 TeV collected in 1992-1995 by the CDF experiment. Finding no events that pass our selection, we set sigma x BR limits on two supersymmetric processes that can produce this experimental signature: gluino-gluino or squark-antisquark production with R-parity violating decays of the charm squark or lightest neutralino via a nonzero lambda'(121) coupling. We compare our results to the next-to-leading order calculations for gluino and squark production cross sections and set lower limits on M((g) over tilde), M((t) over tilde(1)), and M((q) over tilde). C1 KEK, Natl Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Toronto, Toronto, ON M5S 1A7, Canada. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Illinois, Urbana, IL 61801 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Harvard Univ, Cambridge, MA 02138 USA. Univ Geneva, CH-1211 Geneva 4, Switzerland. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Florida, Gainesville, FL 32611 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Duke Univ, Durham, NC 27708 USA. Univ Chicago, Chicago, IL 60637 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Brandeis Univ, Waltham, MA 02254 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Argonne Natl Lab, Argonne, IL 60439 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Acad Sinica, Taipei 11530, Taiwan. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 315, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Abe, F (reprint author), KEK, Natl Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. RI Introzzi, Gianluca/K-2497-2015; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Peters, Michael/B-4973-2009; Nomerotski, Andrei/A-5169-2010; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Paulini, Manfred/N-7794-2014 OI Introzzi, Gianluca/0000-0002-1314-2580; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787 NR 37 TC 39 Z9 39 U1 0 U2 0 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 SEP 13 PY 1999 VL 83 IS 11 BP 2133 EP 2138 DI 10.1103/PhysRevLett.83.2133 PG 6 WC Physics, Multidisciplinary SC Physics GA 234LC UT WOS:000082485300010 ER PT J AU Wiedenhover, I Janssens, RVF Hackman, G Ahmad, I Greene, JP Amro, H Bhattacharyya, PK Carpenter, MP Chowdhury, P Cizewski, J Cline, D Khoo, TL Lauritsen, T Lister, CJ Macchiavelli, AO Nisius, DT Reiter, P Seabury, EH Seweryniak, D Siem, S Sonzogni, A Uusitalo, J Wu, CY AF Wiedenhover, I Janssens, RVF Hackman, G Ahmad, I Greene, JP Amro, H Bhattacharyya, PK Carpenter, MP Chowdhury, P Cizewski, J Cline, D Khoo, TL Lauritsen, T Lister, CJ Macchiavelli, AO Nisius, DT Reiter, P Seabury, EH Seweryniak, D Siem, S Sonzogni, A Uusitalo, J Wu, CY TI Octupole correlations in the Pu isotopes: From vibration to static deformation? SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-SPIN; CONTRASTING BEHAVIOR; NUCLEI; BANDS AB In a series of measurements with Gammasphere, striking differences were found between the yrast and negative parity bands in Pu238-240 and those in Pu241-244. These differences can be linked to variations with mass of the strength of octupole correlations. At the highest spins, Pu238-240,, found to exhibit properties associated with stable octupole deformation, suggesting that a transition with spin from a vibration to stable deformation may have occurred. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Kansas, Lawrence, KS 66045 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Massachusetts, Lowell, MA 01854 USA. Rutgers State Univ, New Brunswick, NJ 08903 USA. Univ Rochester, Rochester, NY 14627 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Oslo, Oslo, Norway. RP Wiedenhover, I (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 19 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 SEP 13 PY 1999 VL 83 IS 11 BP 2143 EP 2146 DI 10.1103/PhysRevLett.83.2143 PG 4 WC Physics, Multidisciplinary SC Physics GA 234LC UT WOS:000082485300012 ER PT J AU Shvartsburg, AA Liu, B Lu, ZY Wang, CZ Jarrold, MF Ho, KM AF Shvartsburg, AA Liu, B Lu, ZY Wang, CZ Jarrold, MF Ho, KM TI Structures of germanium clusters: Where the growth patterns of silicon and germanium clusters diverge SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; PHOTOELECTRON-SPECTROSCOPY; SEMICONDUCTOR CLUSTERS; ENERGY SEPARATIONS; IONS; GE; GEOMETRIES; STATES; SI AB We have performed a systematic ground state geometry search for Ge, neutrals and cations in the n less than or equal to 16 size range using density functional theory-local density approximation and gradient-corrected methods. Like their silicon analogs, medium-sized Ge clusters are stacks of tricapped trigonal prism subunits. However, the structures of Ge-n and Si-n for n = 13 and n greater than or equal to 15 differ in details. The onset of the structural divergence between the growth patterns of Si and Ge clusters is confirmed by the measurements of gas phase ion mobilities, fragmentation pathways, and dissociation energies. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Shvartsburg, AA (reprint author), Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI 上官, 敏慧/E-8964-2012 NR 31 TC 109 Z9 110 U1 2 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 SEP 13 PY 1999 VL 83 IS 11 BP 2167 EP 2170 DI 10.1103/PhysRevLett.83.2167 PG 4 WC Physics, Multidisciplinary SC Physics GA 234LC UT WOS:000082485300018 ER PT J AU Gurevich, AV Sergeichev, KF Sychov, IA Roussel-Dupre, R Zybin, KP AF Gurevich, AV Sergeichev, KF Sychov, IA Roussel-Dupre, R Zybin, KP TI First observations of runaway breakdown phenomenon in laboratory experiments SO PHYSICS LETTERS A LA English DT Article ID AIR BREAKDOWN; THUNDERSTORM; DISCHARGES; FIELDS AB Microwave electron cyclotron resonance discharge in air is studied in a time-varying magnetic mirror trap. The obtained experimental data demonstrate a rapid increase in the number of fast electrons with wide energy spectrum (1-300 keV). It is followed by strong flashes of gamma photons and associated secondary optic emission. The experimental results are interpreted as the first observation in a laboratory of the runaway breakdown phenomenon, which plays a significant role in a thunderstorm atmosphere. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 PN Lebedev Phys Inst, Moscow 117924, Russia. Russian Acad Sci, Inst Gen Phys, Moscow, Russia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gurevich, AV (reprint author), PN Lebedev Phys Inst, Leninsky Prospect 53, Moscow 117924, Russia. RI Zybin, Kirill/K-8619-2015; Gurevich, Aleksandr/K-8668-2015 OI Gurevich, Aleksandr/0000-0003-1125-9774 NR 13 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD SEP 13 PY 1999 VL 260 IS 3-4 BP 269 EP 278 DI 10.1016/S0375-9601(99)00435-1 PG 10 WC Physics, Multidisciplinary SC Physics GA 241ET UT WOS:000082870300015 ER PT J AU Borisov, OV Mao, XL Fernandez, A Caetano, M Russo, RE AF Borisov, OV Mao, XL Fernandez, A Caetano, M Russo, RE TI Inductively coupled plasma mass spectrometric study of non-linear calibration behavior during laser ablation of binary Cu-Zn Alloys SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE laser ablation; inductively coupled plasma; mass spectrometry; cu and zn binary alloys; brass materials; calibration ID ATOMIC EMISSION-SPECTROMETRY; LAM-ICP-MS; GEOLOGICAL-MATERIALS; ELEMENTAL ANALYSIS; SULFIDE MINERALS; TRACE-ELEMENTS; EXCIMER-LASER; MICROPROBE; METALS; ENVIRONMENT AB Laser ablation behavior of a suite of 10 Cu-Zn binary alloys was studied using inductively coupled plasma mass spectrometry. Three laser systems (20 ns KrF excimer, 6 ns and 35 ps Nd:YAG) were used for ablation. Non-linear calibration plots for both Cu and Zn were observed using all three lasers, despite significant differences in laser ablation mechanisms and good stoichiometry of ablated mass. Crater volume measurements were used to determine the amount of mass removed during repetitive laser ablation from each sample. A change in mass ablation rate for samples with different composition explains observed phenomena. Despite the differences in ablation behavior of these alloys, linear calibration curves were obtained when Zn signal intensity was normalized to signal intensity of Cu or to crater volume. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Cent Univ Venezuela, Escuela Quim, Caracas 1020A, Venezuela. RP Russo, RE (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 32 TC 72 Z9 72 U1 3 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD SEP 13 PY 1999 VL 54 IS 9 BP 1351 EP 1365 DI 10.1016/S0584-8547(99)00083-X PG 15 WC Spectroscopy SC Spectroscopy GA 235JE UT WOS:000082537900008 ER PT J AU Servidei, S Capon, F Spinazzola, A Mirabella, M Semprini, S de Rosa, G Gennarelli, M Sangiuolo, F Ricci, E Mohrenweiser, HW Dallapiccola, B Tonali, P Novelli, G AF Servidei, S Capon, F Spinazzola, A Mirabella, M Semprini, S de Rosa, G Gennarelli, M Sangiuolo, F Ricci, E Mohrenweiser, HW Dallapiccola, B Tonali, P Novelli, G TI A distinctive autosomal dominant vacuolar neuromyopathy linked to 19p13 SO NEUROLOGY LA English DT Article DE autosomal dominant vacuolar neuromyopathy; rimmed vacuoles; linkage ID GIRDLE MUSCULAR-DYSTROPHY; INCLUSION-BODY MYOSITIS; DISTAL MYOPATHY; LOCUS HETEROGENEITY; LINKAGE ANALYSIS; RIMMED VACUOLES; PHYSICAL MAP; CARDIOMYOPATHY; INHERITANCE; BLOCK AB Objective: To characterize a kindred with a distinctive autosomal dominant neuromuscular disorder. Background: The authors studied a large Italian family affected by a progressive neuromyopathy. Ten individuals over three generations were affected. The disease was characterized by onset from the late teens-to early 50s with distal leg weakness and atrophy, development of generalized muscle weakness with distal-to-proximal progression sparing facial and ocular muscles, dysphonia and dysphagia, pes cavus and areflexia, variable clinical expression ranging from subclinical myopathy to severely disabling weakness, and mixed neurogenic and myopathic abnormalities on electromyography. Methods: Morphologic, immunocytochemical, and ultrastructural studies were performed in muscle biopsies from three affected patients. A genomewide linkage analysis through the genotyping of 292 microsatellite markers spanning the 22 autosomes was undertaken to map the disorder segregating in this family. Results: All muscle biopsies showed variation of fiber size, panesterase-positive angular fibers, mild to severe fibrosis, and numerous "rimmed vacuoles." Electron microscopy failed to demonstrate the nuclear or cytoplasmic filamentous inclusions specific of inclusion-body myopathies and, accordingly, immunohistochemistry did not show any positivity with SMI-31 antibodies detecting hyperphosphorylated tau. Preliminary analysis of 292 microsatellite markers provided evidence for Linkage to chromosome 19p13. Conclusions: This distinctive autosomal dominant disorder is characterized by a vacuolar neuromyopathy. Localization to chromosome 19p13 will allow the genetic relationship between this disease and inherited myopathies with rimmed vacuoles, in particular autosomal dominant inclusion-body myopathies, to be defined. C1 Catholic Univ Rome, Policlin Gemelli, Inst Neurol, I-00168 Rome, Italy. UILDM, Rome, Italy. Univ Roma Tor Vergata, Cattedra Genet Umana, Dipartimento Biopatol & Diagnost Immagini, Rome, Italy. IRCCS, Osped CSS, San Giovanni Rotondo, Italy. Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA USA. RP Servidei, S (reprint author), Catholic Univ Rome, Policlin Gemelli, Inst Neurol, Largo A Gemelli 8, I-00168 Rome, Italy. RI Capon, Francesca/F-4763-2011; Gennarelli, Massimo/B-1377-2010; Dallapiccola, Bruno/K-8692-2016; OI Capon, Francesca/0000-0003-2432-5793; Dallapiccola, Bruno/0000-0002-5031-1013; sangiuolo, federica/0000-0002-6227-4248; RICCI, Enzo/0000-0003-3092-3597; Novelli, Giuseppe/0000-0002-7781-602X FU Telethon [1076] NR 38 TC 20 Z9 21 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0028-3878 J9 NEUROLOGY JI Neurology PD SEP 11 PY 1999 VL 53 IS 4 BP 830 EP 837 PG 8 WC Clinical Neurology SC Neurosciences & Neurology GA 235BF UT WOS:000082518300030 PM 10489050 ER PT J AU Adam, W Bauer, C Berdermann, E Bergonzo, P Bogani, F Borchi, E Brambilla, A Bruzzi, M Colledani, C Conway, J Dabrowski, W Delpierre, P Deneuville, A Dulinski, W van Eijk, B Fallou, A Fizzotti, F Foulon, F Friedl, M Gan, KK Gheeraert, E Grigoriev, E Hallewell, G Hall-Wilton, R Han, S Hartjes, F Hrubec, J Husson, D Kagan, H Kania, D Kaplon, J Karl, C Kass, R Knopfle, KT Krammer, M Logiudice, A Lu, R Manfredi, PF Manfredotti, C Marshall, RD Meier, D Mishina, M Oh, A Pan, LS Palmieri, VG Pernicka, M Peitz, A Pirollo, S Polesello, P Pretzl, K Re, V Riester, JL Roe, S Roff, D Rudge, A Schnetzer, S Sciortino, S Speziali, V Stelzer, H Stone, R Tapper, RJ Tesarek, R Thomson, GB Trawick, M Trischuk, W Vittone, E Walsh, AM Wedenig, R Weilhammer, P Ziock, H Zoeller, M AF Adam, W Bauer, C Berdermann, E Bergonzo, P Bogani, F Borchi, E Brambilla, A Bruzzi, M Colledani, C Conway, J Dabrowski, W Delpierre, P Deneuville, A Dulinski, W van Eijk, B Fallou, A Fizzotti, F Foulon, F Friedl, M Gan, KK Gheeraert, E Grigoriev, E Hallewell, G Hall-Wilton, R Han, S Hartjes, F Hrubec, J Husson, D Kagan, H Kania, D Kaplon, J Karl, C Kass, R Knopfle, KT Krammer, M Logiudice, A Lu, R Manfredi, PF Manfredotti, C Marshall, RD Meier, D Mishina, M Oh, A Pan, LS Palmieri, VG Pernicka, M Peitz, A Pirollo, S Polesello, P Pretzl, K Re, V Riester, JL Roe, S Roff, D Rudge, A Schnetzer, S Sciortino, S Speziali, V Stelzer, H Stone, R Tapper, RJ Tesarek, R Thomson, GB Trawick, M Trischuk, W Vittone, E Walsh, AM Wedenig, R Weilhammer, P Ziock, H Zoeller, M CA RD42 Collaboration TI Review of the development of diamond radiation sensors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Gallium Arsenide and Related Compounds CY JUN 22-26, 1998 CL PRAGUE, CZECH REPUBLIC SP Czech Tech Univ, Charles Univ ID READOUT AB Diamond radiation sensors produced by chemical vapour deposition are studied for the application as tracking detectors in high luminosity experiments. Sensors with a charge collection distance up to 250 mu m have been manufactured. Their radiation hardness has been studied with pions, proton and neutrons up to fluences of 1.9 x 10(15) pi cm(-2), 5 x 10(15) p cm(-2) and 1.35 x 10(15) n cm(-2), respectively. Diamond micro-strip detectors with 50 mu m pitch have been exposed in a high-energy test beam in order to investigate their charge collection properties. The measured spatial resolution using a centre-of-gravity position finding algorithm corresponds to the digital resolution for this strip pitch. First results from a strip tracker with a 2 x 4 cm(2) surface area are reported as well as the performance of a diamond tracker read out by radiation-hard electronics with 25 ns shaping time. Diamond pixel sensors have been prepared to match the geometries of the recently available read-out chip prototypes for ATLAS and CMS. Beam test results an shown from a diamond detector bump-bonded to an ATLAS prototype read-out. They demonstrate a 98% bump-bonding efficiency and a digital resolution in both dimensions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Osterr Akad Wissensch, Inst Hochenergiephys, A-1050 Vienna, Austria. MPI Kernphys, D-69029 Heidelberg, Germany. GSI Darmstadt, D-6100 Darmstadt, Germany. CEA Saclay, SPE, DEIN, LETI,CEA Technol Avancees, F-91191 Gif Sur Yvette, France. LENS, Florence, Italy. Univ Florence, Florence, Italy. Univ Strasbourg 1, CNRS, IN2P3, LEPSI, F-67037 Strasbourg, France. Rutgers State Univ, Piscataway, NJ 08855 USA. CERN, CH-1211 Geneva 23, Switzerland. CPPM, F-13288 Marseille, France. LEPES, Grenoble, France. NIKHEF, Amsterdam, Netherlands. Univ Turin, Turin, Italy. Ohio State Univ, Columbus, OH 43210 USA. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ Hamburg, Inst Expt Phys 2, D-2000 Hamburg, Germany. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. FNAL, Batavia, IL USA. Lab Hochenergiephys, CH-3012 Bern, Switzerland. Univ Toronto, Toronto, ON M5S 1A7, Canada. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hrubec, J (reprint author), Osterr Akad Wissensch, Inst Hochenergiephys, A-1050 Vienna, Austria. RI Krammer, Manfred/A-6508-2010; Lo Giudice, Alessandro/J-4567-2012; Grigoriev, Eugene/K-6650-2013; Bruzzi, Mara/K-1326-2015; Bergonzo, Philippe/A-6567-2015; Gheeraert, Etienne/E-8071-2015; OI Krammer, Manfred/0000-0003-2257-7751; Re, Valerio/0000-0003-0697-3420; Sciortino, Silvio/0000-0003-0570-7489; Lo Giudice, Alessandro/0000-0003-4753-3165; Grigoriev, Eugene/0000-0001-7235-9715; Bruzzi, Mara/0000-0001-7344-8365; Bergonzo, Philippe/0000-0002-0647-9134; Gheeraert, Etienne/0000-0002-9952-5805; vittone, ettore/0000-0003-3133-3687 NR 16 TC 47 Z9 49 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 11 PY 1999 VL 434 IS 1 BP 131 EP 145 DI 10.1016/S0168-9002(99)00447-7 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 232XJ UT WOS:000082395000020 ER PT J AU Cisale, HO Fischman, ML Campi, S Blasi, CD Fernandez, HA Gledhill, BL AF Cisale, HO Fischman, ML Campi, S Blasi, CD Fernandez, HA Gledhill, BL TI Reduction of bacterial contamination of bovine semen by filtration SO VETERINARY RECORD LA English DT Article ID ARTIFICIAL-INSEMINATION C1 Univ Buenos Aires, Fac Ciencias Vet, Area Fis Biol, Lab Espermatol, RA-1427 Buenos Aires, DF, Argentina. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Cisale, HO (reprint author), Univ Buenos Aires, Fac Ciencias Vet, Area Fis Biol, Lab Espermatol, Chorroarin 280, RA-1427 Buenos Aires, DF, Argentina. NR 9 TC 0 Z9 0 U1 0 U2 0 PU BRITISH VETERINARY ASSOC PI LONDON PA 7 MANSFIELD ST, LONDON, ENGLAND W1M 0AT SN 0042-4900 J9 VET REC JI Vet. Rec. PD SEP 11 PY 1999 VL 145 IS 11 BP 314 EP 315 PG 6 WC Veterinary Sciences SC Veterinary Sciences GA 240NR UT WOS:000082832500009 PM 10515619 ER PT J AU Allam, SS Tucker, DL Lin, HA Hashimoto, Y AF Allam, SS Tucker, DL Lin, HA Hashimoto, Y TI Star formation in Las Campanas compact groups SO ASTROPHYSICAL JOURNAL LA English DT Article DE catalogs; galaxies : clusters : general; galaxies : interactions; galaxies : starburst ID REDSHIFT SURVEY; FORMATION RATES; GALAXIES AB Compact groups (CGs) of galaxies offer an exceptional laboratory for the study of dense galactic environments, where interactions, tidally induced activity, and mergers are expected to be at their highest rate of occurrence. Here we present first results from a new catalog of compact groups, one based on the Las Campanas Redshift Survey (LCRS). Using the equivalent width of [O II] lambda 3727, we have studied the star formation activity in LCRS CGs: we find strong evidence of depressed star formation in CGs relative to that in loose groups or the field. Although much of this effect can be ascribed to a morphological mix (CGs contain a high fraction of early-type galaxies), there is some evidence that the star formation rate in late-type galaxies is particularly deficient-perhaps only one-half to one-third that of field spiral galaxies. We conclude that gas-stripping mechanisms may play a role in CG environments. C1 Helwan Observ, Natl Res Inst Astron & Geophys, Cairo 11421, Egypt. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. RP Allam, SS (reprint author), Helwan Observ, Natl Res Inst Astron & Geophys, Cairo 11421, Egypt. NR 19 TC 17 Z9 17 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1999 VL 522 IS 2 BP L89 EP L92 DI 10.1086/312224 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232FN UT WOS:000082360400003 ER PT J AU Nielsen, IMB Janssen, CL AF Nielsen, IMB Janssen, CL TI Double-substitution-based diagnostics for coupled-cluster and Moller-Plesset perturbation theory SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; WAVE-FUNCTIONS; HARMONIC FREQUENCIES; ORBITAL METHODS AB New diagnostics are proposed for coupled-cluster and M phi ller-Plesset perturbation theory. The diagnostics, designated D-2(CCSD) and D-2(MP1), are computed from the double-substitution amplitudes in the CCSD and MP1 wavefunctions, and their definitions are analogous to those of the single-substitution-based D-1(CCSD) and D-1(MP2) diagnostics. The correlation between the magnitude of the new diagnostics and the performance of the CCSD and MP2 methods is demonstrated for prediction of structures and harmonic vibrational frequencies for 34 molecules, and the application of D-1, and D2 to diradicals and bond dissociation is also discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Nielsen, IMB (reprint author), Sandia Natl Labs, MS 9214, Livermore, CA 94551 USA. EM ibniels@idap2.ca.sandia.gov; cljanss@sandia.gov NR 27 TC 33 Z9 33 U1 2 U2 15 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 SEP 10 PY 1999 VL 310 IS 5-6 BP 568 EP 576 DI 10.1016/S0009-2614(99)00770-8 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 238JL UT WOS:000082707100026 ER PT J AU Lobree, LJ Hwang, IC Reimer, JA Bell, AT AF Lobree, LJ Hwang, IC Reimer, JA Bell, AT TI Investigations of the state of Fe in H-ZSM-5 SO JOURNAL OF CATALYSIS LA English DT Article ID TEMPERATURE-PROGRAMMED DESORPTION; ION-EXCHANGED ZSM-5; FE/ZSM-5 CATALYSTS; NITRIC-OXIDE; Y ZEOLITE; ADSORPTION; NO; IR; SPECTROSCOPY; DURABILITY AB The state of Fe dispersion in Fe-H-ZSM-5 was investigated by means of infrared spectroscopy of adsorbed NO, temperature-programmed desorption (TPD) of NO, TPD of NH3, and H-2 temperature-programmed reduction (TPR). For samples with a low loading of Fe [e.g., Fe/Al ratio less than or equal to 0.56], Fe cations exchange with Bronsted acid protons on a one-to-one basis, while at Fe/Al ratios above this level small particles of FeOx are formed, Results of H-2 TPR and NO uptake experiments on Fe-ZSM-5 samples following a He pretreatment suggest that the primary form of Fe present on samples with an Fe/Al ratio less than or equal to 0.19 is Fe3+ [i.e., Fe3+(OH-)(2)]. An increase in the Fe loading above this level results in an increase in the concentration of Fe2+ cations formed via the autoreduction of Fe3+(OH-)(2) which is present at highly reducible alpha sites in ZSM-5. Three types of Fe2+ sites are observed on Fe-ZSM-5 during the room temperature adsorption of NO. They are defined as type I, II, and III sites. Type I sites adsorb NO as mononitrosyls (1767 cm(-1)) and dinitrosyls (1917 and 1806 cm(-1)). Types II and III sites adsorb NO solely as mononitrosyl species (1876 and 1856 cm(-1), respectively). While types II and III sites are found to be relatively resistant to oxidation and reduction, type I sites are significantly affected by these pretreatments. The most notable change occurs for the high-weight-loaded Fe-ZSM-5 sample in which CO reduction results in the redispersion of FeOx to type I sites, (C) 1999 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Lobree, LJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. OI Bell, Alexis/0000-0002-5738-4645 NR 26 TC 286 Z9 294 U1 6 U2 77 PU ACADEMIC PRESS INC 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 SEP 10 PY 1999 VL 186 IS 2 BP 242 EP 253 DI 10.1006/jcat.1999.2548 PG 12 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 239VF UT WOS:000082789800002 ER PT J AU Overbury, SH Mullins, DR Huntley, DR Kundakovic, L AF Overbury, SH Mullins, DR Huntley, DR Kundakovic, L TI Chemisorption and reaction of NO and N2O on oxidized and reduced ceria surfaces studied by soft X-ray photoemission spectroscopy and desorption spectroscopy SO JOURNAL OF CATALYSIS LA English DT Article DE NO reduction; NO, nitric oxide; N2O, nitrous oxide; ceria, CeO2; X-ray photoelectron spectroscopy; near edge x-ray absorption spectroscopy; thermal desorption spectroscopy ID SELECTIVE CATALYTIC REDUCTION; CO OXIDATION-KINETICS; NITRIC-OXIDE; SUPPORTED RHODIUM; ADSORPTION; XPS; RU(001); EXHAUST; TIO2; RH AB We have examined the chemisorption and reaction of NO and N2O on ceria surfaces by soft X-ray photoelectron spectroscopy (SXPS), X-ray absorption spectroscopy, and isothermal and temperature programmed desorption (TPD) spectroscopy. Samples include highly oriented CeO2(100) and CeO2(111) thin films with surfaces of variable oxidation states. CeO2(111) thin films were grown in situ allowing control over the initial oxidation state of the ceria surface, quantitatively determined by valence band, Ce 4d, and Ce 3d photoemission. Following NO exposure, various N-containing surface species were observed by N 1s photoemission, and the distribution of these species depended upon surface oxidation state, exposure, and adsorption temperature. These species included N2O, nitrite, NO-, and three states believed to be associated with atomic or anionic forms of N, Nitrite and N2O are seen on a fully oxidized surface while NO-, N2O, and dissociation products are observed on a reduced surface. The primary reaction of NO with reduced ceria is reoxidation of the ceria by the NO, both by NO- formation and by NO dissociation, leading to immediate and thermally induced N-2 desorption. Adsorption of NO at 150 K is predominantly molecular while exposure to NO at 400 K leads to a thermally activated nitride which desorbs at temperatures above 500 K. Dissociative adsorption of NO leads to the displacement of N3- at high exposures. (C) 1999 Academic Press. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Overbury, SH (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 4500 N,MS 6201, Oak Ridge, TN 37831 USA. RI Overbury, Steven/C-5108-2016 OI Overbury, Steven/0000-0002-5137-3961 NR 46 TC 95 Z9 95 U1 4 U2 28 PU ACADEMIC PRESS INC 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 SEP 10 PY 1999 VL 186 IS 2 BP 296 EP 309 DI 10.1006/jcat.1999.2577 PG 14 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 239VF UT WOS:000082789800006 ER PT J AU Chen, KD Khodakov, A Yang, J Bell, AT Iglesia, E AF Chen, KD Khodakov, A Yang, J Bell, AT Iglesia, E TI Isotopic tracer and kinetic studies of oxidative dehydrogenation pathways on vanadium oxide catalysts SO JOURNAL OF CATALYSIS LA English DT Article ID ALKANE REACTIONS; REACTION NETWORK; PROPANE; OXYDEHYDROGENATION; MOLYBDATE; ZIRCONIA; H-ZSM5; STATE AB Kinetic analysis and isotopic tracer studies mere used to identify elementary steps and their reversibility in the oxidative dehydrogenation of propane on VOx/ZrO2 catalysts with VOx surface densities between 1.6 and 6 VOx/nm(2). Competitive reactions of C3H6 and (CH3CH2CH3)-C-13 showed that CO forms via secondary combustion of propene intermediates. CO2 formed via this reaction and also via the direct combustion of propane. Reactions of O-18(2)/C3H8 mixtures on supported (V2O5)-O-16 led to the preferential initial appearance of lattice O-16 atoms in all oxygen-containing products, as expected if lattice oxygens were required for the activation of C-H bonds. Isotopically mixed Oz species were not detected during reactions of C3H8-O-18(2)-O-16(2) reactant mixtures. Therefore, dissociative Oz chemisorption steps are irreversible. Similarly, C3H8-C3D8-O-2 reactants undergo oxidative dehydrogenation without forming C3H8-xDx mixed isotopomers, suggesting that C-H bond activation steps are also irreversible. Normal kinetic isotopic effects (k(C-H)/k(C-D) = 2.5) were measured for primary oxidative dehydrogenation reactions. Kinetic isotope effects were slightly lower for propane and propene combustion steps (1.7 and 2.2, respectively). These data are consistent with kinetically relevant steps involving the dissociation of C-H bonds in propane and propene. C3H6-D2O and C3D6-H2O cross exchange reactions occur readily during reaction; therefore, OH recombination steps are reversible and nearly equilibrated. These isotopic tracer results are consistent with a Mars-van Krevelen redox mechanism involving two lattice oxygens in irreversible C-H bond activation steps. The resulting alkyl species desorb as propene and the remaining O-H group recombines with neighboring OH groups to form water and reduced V centers. These reduced V centers reoxidize by irreversible dissociative chemisorption of O-2. The application of pseudo-steady-state and reversibility assumptions leads to a complex kinetic rate expression that describes accurately the observed water inhibition effects and the kinetic orders in propane and oxygen when surface oxygen and OH groups are assumed to be the most abundant surface intermediates. (C) 1999 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Bell, AT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Khodakov, Andrei/I-3379-2014; Iglesia, Enrique/D-9551-2017; OI Khodakov, Andrei/0000-0003-4599-3969; Iglesia, Enrique/0000-0003-4109-1001; Bell, Alexis/0000-0002-5738-4645 NR 23 TC 196 Z9 198 U1 8 U2 57 PU ACADEMIC PRESS INC 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 SEP 10 PY 1999 VL 186 IS 2 BP 325 EP 333 DI 10.1006/jcat.1999.2510 PG 9 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 239VF UT WOS:000082789800009 ER PT J AU Broyles, BS Shalliker, RA Guiochon, G AF Broyles, BS Shalliker, RA Guiochon, G TI Visualization of sample introduction in liquid chromatography columns - The effect of the frit diameter SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE frit diameter; visualization of sample introduction; sample introduction AB A previously developed on-column detection technique using 35 mm SLR cameras [J. Chromatogr. A 826 (1998) 1] was employed to visualize colored sample bands as they elute through frits of differing diameter. Head fittings containing a 4.0 mm frit and a 15.9 mm frit were mounted in a 17 mm I.D. glass column packed with C-18 silica with an average particle size of 21 mu m. A carbon tetrachloride mobile phase of matching refractive index to that of the silica provides clarity along the column diameter during band migration. The photographs of the migrating sample zones were scanned and analyzed with appropriate imaging software. The smallest diameter frit induced severely parabolic sample distributions at the column inlet compared to the larger frit. Local axial dispersion coefficient values, expressed as local reduced plate height, were calculated as well as local zone velocities at the column inlet. The results demonstrate clearly the need to match the diameter of the inlet frit to the I.D. of the column so as to avoid the initial onset of zone broadening due to the frit. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 8 TC 30 Z9 32 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 SEP 10 PY 1999 VL 855 IS 2 BP 367 EP 382 DI 10.1016/S0021-9673(99)00737-2 PG 16 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 238YK UT WOS:000082742200002 PM 10519081 ER PT J AU Kele, M Guiochon, G AF Kele, M Guiochon, G TI Repeatability and reproducibility of retention data and band profiles on reversed-phase liquid chromatography columns III. Results obtained with Kromasil C-18 columns SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE band profiles; Kromasil C-18; stationary phases; LC; retention data ID STRONGLY BASIC COMPOUNDS; STATIONARY-PHASE; HOMOLOGOUS SERIES; BONDING DENSITY; BONDED PHASES; HPLC COLUMNS; PERFORMANCE; SELECTIVITY; PH; PHARMACEUTICALS AB The reproducibility of the retention data and the band profiles was investigated with Kromasil C-18 columns (silica-based monomeric type reversed-phase packing material). High precision data were obtained and statistically compared among five columns from the same batch (column-to-column reproducibility) and six columns, one from each of six different batches (batch-to-batch reproducibility). These data were acquired under five different sets of chromatographic conditions, for a group of 30 neutral, acidic and basic compounds selected as probes following an experimental protocol previously described. Data characterizing the retention time, the retention factor, the separation factor, the column efficiency and the peak asymmetry for the different probe compounds are reported. Factors describing the silica surface interaction with the selected probe compounds, such as the hydrophobic interaction selectivity, the steric selectivity, and the separation factors of basic compounds at different pH values were also determined. The influence of the underlying silica on these data and correlations between the chromatographic and physico-chemical properties of the different batches are discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, 611 Buehler Hall, Knoxville, TN 37996 USA. NR 54 TC 74 Z9 75 U1 1 U2 8 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 SEP 10 PY 1999 VL 855 IS 2 BP 423 EP 453 DI 10.1016/S0021-9673(99)00746-3 PG 31 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 238YK UT WOS:000082742200006 PM 10519085 ER PT J AU Concus, P Finn, R Weislogel, M AF Concus, P Finn, R Weislogel, M TI Capillary surfaces in an exotic container: results from Space experiments SO JOURNAL OF FLUID MECHANICS LA English DT Article AB Experimental results from the Interface Configuration Experiment (ICE) performed aboard the Space Shuttle and the Mir Space Station are reported. The experiment concerns fluid interfaces in certain 'exotic' containers in a low-gravity environment. These containers are rotationally symmetric and have the property that for given contact angle and liquid volume, a continuum of distinct rotationally symmetric equilibrium configurations can appear, all of which have the same mechanical energy. These symmetric equilibrium configurations are unstable, in that deformations that are not rotationally symmetric can be shown mathematically to yield configurations with lower energy. It is found experimentally, in confirmation of mathematical results and of numerical computations, that distinct locally stable configurations can form that are not rotationally symmetric and have differing dynamic characteristics. It is found that this intriguing phenomenon of asymmetric local energy minimizers can occur even if conditions for an exotic container are not entirely met. 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. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Concus, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 14 TC 9 Z9 9 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD SEP 10 PY 1999 VL 394 BP 119 EP 135 DI 10.1017/S0022112099005789 PG 17 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 238AW UT WOS:000082689600006 ER PT J AU Kaufman, AN Morehead, JJ Brizard, AJ Tracy, ER AF Kaufman, AN Morehead, JJ Brizard, AJ Tracy, ER TI Mode conversion in the Gulf of Guinea SO JOURNAL OF FLUID MECHANICS LA English DT Article ID EQUATORIAL ATLANTIC; FORMULATION; OCEAN; WAVES AB Linear mode conversion is the partial transfer of wave energy from one wave type (a) to another (b) in a weakly non-uniform background state. For propagation in one dimension (x), the local wavenumber k(x)(j) of each wave (j = a, b) varies with x; if these are equal at some x(R), the waves are locally in phase, and resonant energy transfer can occur. We model wave propagation in the Gulf of Guinea, where wave a is an equatorially trapped Rossby-gravity (Yanai) wave, and wave b is a coastal Kelvin wave along the (zonal) north coast of the Gulf both propagating in zonal coordinate x. The coupling of the waves is due to the overlap of their eigenfunctions (normal modes in y, the meridional coordinate). We derive coupled mode equations from a variational principle, and obtain an analytic expression for the wave-energy conversion coefficient, in terms of the wave frequency and the scale length of the thermocline depth. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. RP Kaufman, AN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. OI Brizard, Alain/0000-0002-0192-6273 NR 21 TC 12 Z9 12 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD SEP 10 PY 1999 VL 394 BP 175 EP 192 DI 10.1017/S0022112099005649 PG 18 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 238AW UT WOS:000082689600008 ER PT J AU Hollerman, W Holland, L Ila, D Hensley, J Southworth, G Klasson, T Taylor, P Johnston, J Turner, R AF Hollerman, W Holland, L Ila, D Hensley, J Southworth, G Klasson, T Taylor, P Johnston, J Turner, R TI Results from the low level mercury sorbent test at the Oak Ridge Y-12 Plant in Tennessee SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE sorbent; mercury; mercury contamination; mercury pollution; method 1631 ID WASTE-WATER; REMOVAL AB A mercury sorbent test was performed near the headwaters of the Upper East Fork Poplar Creek at the Oak Ridge Y-12 Plant in Tennessee. The sorbents SIR-200 (ResinTech), Keyle:X (SolmeteX), and GT-73 (Rohm and Haas) were the best materials tested for low level mercury removal. Each of these sorbents has a thiol-based active site. None of the tested sorbents reduced the mercury concentration to less than the existing 12 ng/l NPDES limit. For this small scale test, SIR-200, Keyle:X, and GT-73 reduced the mercury concentration to less than 51 ng/l, which is a regulatory treatment goal. The other sorbents tested, including granular activated carbon (Filtrasorb 300), did not reduce the mercury concentration below 51 ng/l at any tested flow up to 5 bed volumes per minute. Because of the cost and large volume of sorbent, a wastewater treatment plant for this stream would be prohibitively expensive to construct and maintain. Published by Elsevier Science B.V. C1 Univ SW Louisiana, Acadiana Res Lab, Lafayette, LA 70504 USA. Alabama A&M Univ, Ctr Irradiat Mat, Normal, AL 35762 USA. Y12 Plant Environm Restorat Program, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. TN & Associates, Oak Ridge, TN 37830 USA. Frontier Geosci, Seattle, WA 98109 USA. RP Hollerman, W (reprint author), 309 Timothy Dr, Lafayette, LA 70503 USA. RI Hollerman, William/F-5943-2011; OI Klasson, K. Thomas/0000-0003-3358-3081 NR 11 TC 19 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD SEP 10 PY 1999 VL 68 IS 3 BP 193 EP 203 DI 10.1016/S0304-3894(99)00027-8 PG 11 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 245RY UT WOS:000083123000003 PM 10550710 ER PT J AU Ciftja, O AF Ciftja, O TI A simple derivation of the exact wavefunction of a harmonic oscillator with time-dependent mass and frequency SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID EXACT WAVE-FUNCTIONS; VARIABLE MASS AB We present a very simple and efficient method to obtain the exact wavefunction corresponding to the harmonic oscillator with time-dependent mass and frequency. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Ciftja, O (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 13 TC 14 Z9 14 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD SEP 10 PY 1999 VL 32 IS 36 BP 6385 EP 6389 DI 10.1088/0305-4470/32/36/303 PG 5 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 237CX UT WOS:000082638700006 ER PT J AU Lenhart, S Liang, M Protopopescu, V AF Lenhart, S Liang, M Protopopescu, V TI Optimal control of boundary habitat hostility for interacting species SO MATHEMATICAL METHODS IN THE APPLIED SCIENCES LA English DT Article ID SYSTEMS AB We consider boundary control for a parabolic system describing the evolution of two interacting species in a bounded habitat. The control models the hostility of the boundary environment to the maintenance of the species. The objective functional represents the balance between the ecological benefit (modelled by the size of the two populations) and the economic cost of maintaining an ecologically favorable boundary environment (modelled b the boundary friendliness). The unique optimal control is characterized in terms of the solution of the optimality system, which consists of the state system coupled with an adjoint system. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Univ Tennessee, Dept Math, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Lenhart, S (reprint author), Univ Tennessee, Dept Math, Knoxville, TN 37996 USA. NR 22 TC 29 Z9 33 U1 2 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0170-4214 J9 MATH METHOD APPL SCI JI Math. Meth. Appl. Sci. PD SEP 10 PY 1999 VL 22 IS 13 BP 1061 EP 1077 DI 10.1002/(SICI)1099-1476(19990910)22:13<1061::AID-MMA70>3.0.CO;2-I PG 17 WC Mathematics, Applied SC Mathematics GA 228HZ UT WOS:000082132200001 ER PT J AU Berman, GP Doolen, GD Nagaev, KE Rehacek, J AF Berman, GP Doolen, GD Nagaev, KE Rehacek, J TI Predictability of minimum noise in electron transport through a disordered semiconductor SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE electron transport; semiconductor; conductance; mesoscopic; shot noise ID MATRIX AB We present an inverse method for electron transport which allows one to minimize the value of shut noise for a given value of the conductance by optimizing the spatial structure of a disordered semiconductor region. The method is based on the Green's function approach which is usually applied to the direct transport problem. A specific experimentally realizable example of a two-dimensional disordered semiconductor is presented which demonstrates the method of minimization of shot noise for insulator, metallic, and transitional conductance regions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Russian Acad Sci, Inst Radio Engn & Elect, Moscow 103907, Russia. RP Berman, GP (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Nagaev, Kirill/H-6802-2016 OI Nagaev, Kirill/0000-0002-1659-6115 NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 18 EP 22 DI 10.1016/S0167-2789(99)00095-0 PG 5 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500003 ER PT J AU Chen, S Foias, C Holm, DD Olson, E Titi, ES Wynne, S AF Chen, S Foias, C Holm, DD Olson, E Titi, ES Wynne, S TI The Camassa-Holm equations and turbulence SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE Camassa-Holm equations; turbulent channel and pipe flows ID REYNOLDS-NUMBER; CHANNEL FLOW; FLUIDS AB In this paper we will survey our results on the Camassa-Holm equations and their relation to turbulence as discussed in S. Chen, C. Foias, D.D. Helm, E. Olson, E.S. Titi, S. Wynne, The Camassa-Holm equations as a closure model for turbulent channel and pipe flow, Phys. Rev. Lett 81 (1998) 5338. S. Chen, C. Foias, D.D. Helm, E. Olson, E.S. Titi, S. Wynne, A connection between the Camassa-Holm equations and turbulent flows in channels and pipes, Phys. Fluids, in press. In particular we will provide a more detailed mathematical treatment of those equations for pipe flows which yield accurate predictions of turbulent flow profiles for very large Reynolds numbers. There are many facts connecting the Camassa-Holm equations to turbulent fluid flows. The dimension of the attractor agrees with the heuristic argument based on the Kolmogorov statistical theory of turbulence. The statistical properties of the energy spectrum agree in numerical simulation with the Kolmogorov power law. Furthermore, comparison of mean flow profiles for turbulent flow in channels and pipes given by experimental and numerical data show acceptable agreement with the profile of the corresponding solution of the Camassa-Holm equations. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Indiana Univ, Dept Math, Bloomington, IN 47405 USA. Univ Calif Irvine, Dept Math, Irvine, CA 92697 USA. Univ Calif Irvine, Dept Mech Engn, Irvine, CA 92697 USA. Univ Calif Irvine, Dept Aerosp Engn, Irvine, CA 92697 USA. Univ Calif Los Alamos Natl Lab, Inst Geophys & Planetary Phys, Los Alamos, NM 87545 USA. RP Chen, S (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Chen, Shiyi/A-3234-2010; OI Holm, Darryl D/0000-0001-6362-9912 NR 20 TC 124 Z9 128 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 49 EP 65 DI 10.1016/S0167-2789(99)00098-6 PG 17 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500006 ER PT J AU Chen, SY Holm, DD Margolin, LG Zhang, RY AF Chen, SY Holm, DD Margolin, LG Zhang, RY TI Direct numerical simulations of the Navier-Stokes alpha model SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE direct numerical simulation; Navier-Stokes alpha model ID CLASSICAL-SOLUTIONS; REYNOLDS STRESS; TURBULENCE; FLUIDS; EQUATIONS; FAMILY; GRADE; FLOW AB We explore the utility of the recently proposed alpha equations in providing a subgrid model for fluid turbulence, Our principal results are comparisons of direct numerical simulations of fluid turbulence using several values of the parameter alpha, including the Limiting case where the Navier-Stokes equations are recovered. Our studies show that the large scale features, including statistics and structures, are preserved by the alpha models, even at coarser resolutions where the fine scales are nor fully resolved. We also describe the differences that appear in simulations. We provide a summary of the principal features of the alpha equations, and offer some explanation of the effectiveness of these equations used as a subgrid model for three-dimensional fluid turbulence, (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. IBM Corp, Div Res, TJ Watson Res Ctr, Yorktown Heights, NY 10598 USA. Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. Univ Delaware, Dept Mech Engn, Spencer Lab 126, Newark, DE 19716 USA. RP Chen, SY (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RI Chen, Shiyi/A-3234-2010; OI Holm, Darryl D/0000-0001-6362-9912 NR 34 TC 115 Z9 117 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 66 EP 83 DI 10.1016/S0167-2789(99)00099-8 PG 18 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500007 ER PT J AU Cheng, BL Glimm, J Saltz, D Sharp, DH AF Cheng, BL Glimm, J Saltz, D Sharp, DH TI Boundary conditions for a two pressure two-phase flow model SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE unstable fluid mixing; two-phase flow; Rayleigh-Taylor instabilities; Richtmyer-Meshkov instabilities ID RAYLEIGH-TAYLOR INSTABILITY; GROUP FIXED-POINT; 2-PHASE FLOW; NUMERICAL-SIMULATION AB New closures for two pressure two-phase flow in the context of unstable fluid mixing have been proposed recently by the authors. Here we examine the physical basis for the models, the nature of the boundary conditions at the edges of the mixing layer, and an algorithm for the numerical solution of the two-phase flow equations. Physically, the closures describe chunk mix, in which the flow is dominated by coherent structures of size comparable to the mixing zone thickness. The closed form solution previously introduced for the incompressible limit is reviewed and extended. Sufficient boundary conditions for the compressible equations are found from drag and buoyancy laws proposed by others, with coefficients fit to two sets of independent experiments. These laws complete the closure of the two-phase flow equations. A postulate of stationary center of mass, previously introduced at a numerical level, is here related to a weak notion of self similarity and is solved analytically for the ratio of the growth rates of the two sides of the mixing zone in the self similar case. (C) 1999 Elsevier Science B.V. Ail rights reserved. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Cheng, BL (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. NR 28 TC 24 Z9 25 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 84 EP 105 DI 10.1016/S0167-2789(99)00100-1 PG 22 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500008 ER PT J AU Ghanem, R Red-Horse, J AF Ghanem, R Red-Horse, J TI Propagation of probabilistic uncertainty in complex physical systems using a stochastic finite element approach SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE stochastic processes; random media; finite elements; computational mechanics; Karhunen-Loeve; polynomial chaos AB This paper presents an efficient procedure for characterizing the solution of evolution equations with stochastic coefficients. These typically model the behavior of physical systems whose properties are modeled as spatially or temporally varying stochastic processes described within the framework of probability, theory. The concepts of projection, orthogonality and weak convergence are exploited in a manner which directly mimics deterministic finite element solutions except that, in the stochastic case, inner products refer to expectation operations. Specifically, the Karhunen-Loeve expansion is used to discretize these processes into a denumerable set of random variables, thus providing a denumerable function space in which the problem is cast. The polynomial chaos expansion is then used to represent the solution in this space, and the coefficients in the expansion are evaluated as generalized Fourier coefficients via a Galerkin procedure in the Hilbert space of random variables. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Johns Hopkins Univ, Dept Civil Engn, Baltimore, MD 21218 USA. Sandia Natl Labs, Dept 9234, Albuquerque, NM 87185 USA. RP Ghanem, R (reprint author), Johns Hopkins Univ, Dept Civil Engn, Baltimore, MD 21218 USA. RI Ghanem, Roger/B-8570-2008 OI Ghanem, Roger/0000-0002-1890-920X NR 8 TC 90 Z9 90 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 137 EP 144 DI 10.1016/S0167-2789(99)00102-5 PG 8 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500010 ER PT J AU Glimm, J Sharp, DH AF Glimm, J Sharp, DH TI Prediction and the quantification of uncertainty SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE Bayesian inference; Markov chain Monte Carlo; multiphase flow ID RAYLEIGH-TAYLOR INSTABILITY; 2-PHASE FLOW; NUMERICAL-SIMULATION; TURBULENT; MODELS AB Prediction is based on the comparison of results from the statistical analysis of observational data and from the scientific modeling of the system being observed. Effective prediction imposes new as well as familiar requirements on observation and scientific modeling, as will be reviewed here. We emphasize issues specific to prediction in the context of technology. Recent results of the authors, colleagues, and others which address these requirements will be presented. (C) 1999 Elsevier Science B.V. All rights reserved. C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Glimm, J (reprint author), SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. NR 45 TC 32 Z9 32 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 152 EP 170 DI 10.1016/S0167-2789(99)00103-7 PG 19 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500012 ER PT J AU Hills, JG Goda, MP AF Hills, JG Goda, MP TI Damage from comet-asteroid impacts with earth SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE asteroid; comet; impact; tsunami ID OBJECTS AB Only a small fraction of the Earth-crossing asteroids, ECAs, have been found and cataloged. Uncataloged ECAs can hit the atmosphere of Earth without warning. Long-period comets may give as little as two months warning before impact. The damage ranges from fires and blastwaves from energy dissipation in the atmosphere to craters, earthquakes, and tsunami from ground impact. Tsunami damage is particularly severe. An asteroid 5-6km in diameter impacting in the mid Atlantic would cause substantial tsunami damage to both Europe and North America: the tsunami would run all the way to the Appalachians in the upper two-thirds of the United States and to the mountains of the Iberian Peninsula in Europe. Tsunami heights along the Iberian Peninsula can reach several hundred meters. The tsunami heights would be less in Northern Europe due to the shallow continental shelf in this region. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Theoret Astrophys Grp, Los Alamos, NM 87545 USA. RP Hills, JG (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Theoret Astrophys Grp, T-6,MS B288, Los Alamos, NM 87545 USA. NR 10 TC 5 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 189 EP 198 DI 10.1016/S0167-2789(99)00091-3 PG 10 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500015 ER PT J AU Holm, DD AF Holm, DD TI Fluctuation effects on 3D Lagrangian mean and Eulerian mean fluid motion SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies ID REYNOLDS STRESS; EQUATIONS; FLOW; TURBULENCE; MODELS AB We formulate equations for the slow time dynamics of fluid motion that self consistently account for the effects of the variability upon the mean. The time-average effects of the fluctuations introduce nonlinear dispersion that acts to spatially smooth the transport velocity of the mean flow relative to its circulation or momentum velocity, by the inversion of a Helmholtz operator whose length scale corresponds to the covariance of the fluctuations. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Holm, DD (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B284, Los Alamos, NM 87545 USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 44 TC 81 Z9 82 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 215 EP 269 DI 10.1016/S0167-2789(99)00093-7 PG 55 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500017 ER PT J AU Keller, CF AF Keller, CF TI Climate, modeling, and predictability SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE predictability; climate change; nonlinear; ocean-atmosphere interactions; climate variability ID TEMPERATURE; PACIFIC; OSCILLATIONS; VARIABILITY; EQUATORIAL AB Among the most interesting and fascinating phenomena that are predicted are the chaotic ocean/atmosphere/and system called weather and its longtime average climate. While weather is not predictable beyond a few days, aspects of the climate may be predictable for years, decades, and perhaps longer. A major reason for this is the presence within this chaotic system of discernible periodic cycles varying from very low frequency of a hundred thousand years or so to interannual variations such as El Nino and the Quasi biennial Oscillation. This paper is meant as a broad introduction and survey to those interested in predictability, but not familiar with climate variability. No attempt is made to give an exhaustive treatment; rather examples of variability across the temporal spectrum will be given to illustrate behavior and suggest causes. There is also a short treatment of secular and sporadic forcings that complicate attempts to pin down variability of the same time scale. And finally the problem of attribution of anthropogenic forcings is looked at as one that must have major periodic and quasi-periodic phenomena shipped away before it can be isolated quantitatively. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Inst Geophys & Planetary Sci, Los Alamos, NM 87545 USA. RP Keller, CF (reprint author), Univ Calif Los Alamos Natl Lab, Inst Geophys & Planetary Sci, MS C305, Los Alamos, NM 87545 USA. NR 20 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 296 EP 308 DI 10.1016/S0167-2789(99)00086-X PG 13 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500019 ER PT J AU Lythe, GD Proctor, MRE AF Lythe, GD Proctor, MRE TI Predictability of noise-controlled dynamics SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE stochastic PDEs; nonequilibrium dynamics; bifurcations; noisy periodicity; shear instability ID INSTABILITY; CONVECTION; PARAMETER; MODEL; MAGNETOCONVECTION; CHAOS; ORDER AB Noise-controlled dynamics runs counter to usual intuition: the larger the noise the more regular the solutions. We present numerical and analytical results for a set of three stochastic partial differential equations in one space dimension, motivated by the intermittent destabilization of tall thin convection cells by horizontal shear. Time-series are predictable in the sense that they follow Limit cycles with a small variation in amplitude from cycle to cycle. Closer inspection reveals that the amplitude is determined by very small amounts of noise. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB3 9EW, England. RP Lythe, GD (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, B258, Los Alamos, NM 87545 USA. OI Lythe, Grant/0000-0001-7966-5571 NR 23 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 362 EP 370 DI 10.1016/S0167-2789(99)00081-0 PG 9 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500023 ER PT J AU Mahesh, S Beyerlein, IJ Phoenix, SL AF Mahesh, S Beyerlein, IJ Phoenix, SL TI Size and heterogeneity effects on the strength of fibrous composites SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE composite materials; computational mechanics; probability; tensile strength; hexagonal packing ID FIBER-REINFORCED COMPOSITES; BUNDLES PROBABILITY MODEL; MONTE-CARLO SIMULATION; UNIDIRECTIONAL COMPOSITE; TENSILE-STRENGTH; WEIBULL FIBERS; STATISTICS; FRACTURE; FAILURE; RELIABILITY AB Probabilistic fiber composite strength distributions and size scalings depend heavily on both the stress redistribution mechanism around broken fibers and properties of the fiber strength distribution. In this study we perform large scale Monte Carlo simulations to study the fracture process in a fiber composite material in which fibers are arranged in parallel in a hexagonal array and their strengths are given by a two-parameter Weibull distribution function. To calculate the stress redistribution due to several broken fibers, a realistic 3D shear-lag theory is applied to rhombus-shaped domains with periodic boundary conditions. Empirical composite strength distributions are generated from several hundred Monte Carlo replications, particularly for much lower values of fiber Weibull modulus gamma, and larger composite sizes than studied previously. Despite the localized stress enhancements due to fiber failures, predicted by the shear-lag model, composite response displays a transition to equal load sharing like behavior for approximately gamma less than or equal to 1. Accordingly, the results reveal distinct alterations in size effect, failure mode, and weak-link scaling behavior, associated with a transition from stress-driven to fiber strength-driven breakdown. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Cornell Univ, Dept Theoret & Appl Mech, Ithaca, NY 14853 USA. RP Mahesh, S (reprint author), Univ Calif Los Alamos Natl Lab, MST CMS, MS K765, Los Alamos, NM 87545 USA. RI Beyerlein, Irene/A-4676-2011 NR 40 TC 33 Z9 33 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 371 EP 389 DI 10.1016/S0167-2789(99)00082-2 PG 19 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500024 ER PT J AU Margolin, LG Smolarkiewicz, PK Sorbjan, Z AF Margolin, LG Smolarkiewicz, PK Sorbjan, Z TI Large-eddy simulations of convective boundary layers using nonoscillatory differencing SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE advection; nonoscillatory approximations; computational fluid dynamics; large-eddy simulations; boundary layers ID ADVECTION TRANSPORT ALGORITHM; TURBULENCE; EQUATIONS; MODEL; FLOWS AB We explore the ability of nonoscillatory advection schemes to represent the effects of the unresolved scales of motion in numerical simulation of turbulent flows. We demonstrate that a nonoscillatory fluid solver can accurately reproduce the dynamics of an atmospheric convective boundary layer When an explicit turbulence model is implemented, the solver does not add any significant numerical diffusion. Of greater interest, when no explicit turbulence is employed the solver itself appears to include an effective subgrid scale model. Other researchers have reported similar success, simulating turbulent flows in a variety of regimes while using only nonoscillatory advection schemes to model subgrid effects. At this point there is no theory justifying this success, but we offer some speculations. (C)1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Marquette Univ, Milwaukee, WI 53233 USA. RP Margolin, LG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 81 Z9 81 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 390 EP 397 DI 10.1016/S0167-2789(99)00083-4 PG 8 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500025 ER PT J AU Mitkov, I AF Mitkov, I TI One- and two-dimensional wave fronts in diffusive systems with discrete sets of nonlinear sources SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE discrete source; burst waves; front propagation; bistable system ID CHARGE-DENSITY WAVES; EXCITABLE MEDIA; MODEL; DYNAMICS AB We study the dynamics of one-and two-dimensional diffusion systems with sets of discrete nonlinear sources. We show that wave fronts propagating in such systems are pinned if the diffusion constant is below a critical value which corresponds to a saddle-node bifurcation of the dynamics. In two dimensions we find that the dissipation is enhanced and moving plain and circular fronts are stable with respect to any perturbations. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Mitkov, I (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 15 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 398 EP 403 DI 10.1016/S0167-2789(99)00084-6 PG 6 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500026 ER PT J AU Saxena, A Lookman, T AF Saxena, A Lookman, T TI Kinetics of phase separation on curved manifolds: soft matter SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE Laplace-Beltrami operator; curved geometries; phase separation; time-dependent Ginzburg-Landau simulations; vesicles and lipid membranes ID VESICLES AB We study kinetics of phase separation in soft condensed matter systems (e.g. vesicles, tubules, membranes, etc.) for both non-conserved (Model A) and conserved (Model B) dynamics. We first consider phase separation on one-dimensional planar curves for illustrative purposes. We then classify curved manifolds in terms of the presence of either an axis of translation or rotation and derive expressions for the Laplace-Beltrami operator Numerical results are presented for a circular cylinder, an elliptic cylinder and a torus. We find that, in general, local curvature affects the kinetics and shape of the domains. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Western Ontario, Dept Math Appl, London, ON N6A 5B7, Canada. RP Saxena, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 17 TC 5 Z9 5 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 416 EP 426 DI 10.1016/S0167-2789(99)00075-5 PG 11 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500028 ER PT J AU Tartakovsky, DM AF Tartakovsky, DM TI Prediction of steady-state flow of real gases in randomly heterogeneous porous media SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE gas flow; porous media; stochastic ID CONDUCTIVITIES AB We consider steady-state flow of real gases through bounded, randomly heterogeneous porous media. Such how is described by a nonlinear partial differential equation with the random coefficient (medium's permeability) and source terms subject to randomly prescribed boundary conditions. Prior to applying stochastic analysis, the problem is linearized by means of the Kirchhoff transformation which allows us to obtain the exact expressions for an effective (upscaled) gas permeability. In particular, for one-, two-, and three-dimensional mean uniform flows in infinite, statistically homogeneous and isotropic domains the resulting effective permeability is given by harmonic, geometric, and arithmetic averages, respectively. The influence of statistical anisotropy of the random permeability field and domain' s boundaries on the effective gas permeability is also investigated. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Geoanal Grp, Los Alamos, NM 87545 USA. RP Tartakovsky, DM (reprint author), Univ Calif Los Alamos Natl Lab, Geoanal Grp, EES-5,MS C306, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013 NR 13 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 463 EP 468 DI 10.1016/S0167-2789(99)00078-0 PG 6 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500031 ER PT J AU Vorobieff, P Rightley, PM Benjamin, RF AF Vorobieff, P Rightley, PM Benjamin, RF TI Shock-driven gas curtain: fractal dimension evolution in transition to turbulence SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE fractals; turbulence; transition; Richtmyer-Meshkov instability; experiment ID THIN FLUID LAYER; RICHTMYER-MESHKOV INSTABILITY; PLANE; INTERFACE; PATTERNS; GROWTH AB We present estimates of the Hausdorff fractal dimension of a planar section of the interfaces on the sides of a thin curtain of heavy gas (SF6) embedded in air and accelerated with a planar shock wave at Mach 1.2. As the Richtmyer-Meshkov instability develops, eventually leading to a transition to turbulence in the curtain, the fractal dimension of the interfaces increases from an initial value not exceeding 1.10 to a maximum value 1.36 +/- 0.07. This value is close to that experimentally measured for fully developed turbulence. The growth of the fractal dimension is closely related to mixing in the how It represents an important and previously unmeasured property in the transition to turbulence due to Richtmyer-Meshkov instability. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Vorobieff, P (reprint author), Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. RI Vorobieff, Peter/B-3376-2011; OI Vorobieff, Peter/0000-0003-0631-7263 NR 21 TC 17 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 469 EP 476 DI 10.1016/S0167-2789(99)00079-2 PG 8 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500032 ER PT J AU Xie, GQ Li, JH AF Xie, GQ Li, JH TI New parallel stochastic global integral and local differential equation modeling and inversion SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE SGILD; stochastic; modeling and inversion; moments integral and differential equation; posterior probability optimization AB In this paper, a new parallel modeling and inversion algorithm using a Stochastic Global Integral and Local Differential equation (SGILD) decomposition is presented. We derived new acoustic integral equations and differential equations for statistical moments of the parameters and field. The:new statistical moment integral equations on the boundary and local differential equations in domain will be used together to obtain mean wave field and its moments in the modeling. The new moment global Jacobian volume integral equations and the local Jacobian differential equations in domain will be used together to update the mean parameters and their moments in the inversion. A new parallel multiple hierarchy substructure direct algorithm or direct-iteration hybrid algorithm will be used to solve the sparse matrices and one smaller full matrix from domain to the boundary, in parallel. The SGILD modeling and imaging algorithm has many advantages over the conventional imaging approaches. The SGILD algorithm can be used for the stochastic acoustic, electromagnetic, and flow modeling and inversion. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Xie, GQ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, MS 90-1116, Berkeley, CA 94720 USA. NR 10 TC 19 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 477 EP 487 DI 10.1016/S0167-2789(99)00080-9 PG 11 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500033 ER PT J AU Zhang, DX AF Zhang, DX TI Quantification of uncertainty for fluid flow in heterogeneous petroleum reservoirs SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE porous flow; uncertainty; stochastic analysis; moment equation approach; petroleum reservoirs ID ANISOTROPIC POROUS-MEDIA; STEADY-STATE FLOW; VELOCITY COVARIANCES; CONDITIONAL MOMENTS; STOCHASTIC-ANALYSIS; 3-DIMENSIONAL FLOW; GROUNDWATER-FLOW; TRANSPORT; HEAD; NONSTATIONARY AB Detailed description of the heterogeneity of oil/gas reservoirs is needed to make performance predictions of oil/gas recovery. However, only limited measurements at a few locations are usually available, This combination of significant spatial heterogeneity with incomplete information about it leads to uncertainty about the values of reservoir properties and thus, to uncertainty in estimates of production potential. The theory of stochastic processes provides a natural method for evaluating these uncertainties. In this study, we present a stochastic analysis of transient, single phase flow in heterogeneous reservoirs. We derive general equations governing the statistical moments of flow quantities by perturbation expansions. These moments can be used to construct confidence intervals for the flow quantities (e.g., pressure and flow rate). The moment equations are deterministic and can be solved numerically with existing solvers. The proposed moment equation approach has certain advantages over the commonly used Monte Carlo approach. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zhang, DX (reprint author), Univ Calif Los Alamos Natl Lab, EES-5,MS C306, Los Alamos, NM 87545 USA. RI Zhang, Dongxiao/D-5289-2009 OI Zhang, Dongxiao/0000-0001-6930-5994 NR 18 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 488 EP 497 DI 10.1016/S0167-2789(99)00073-1 PG 10 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500034 ER PT J AU Zhou, SJ Preston, DL AF Zhou, SJ Preston, DL TI Short-range dislocation interactions SO PHYSICA D LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NEW MEXICO SP Ctr Nonlinear Studies DE dislocation; jog; junction; intersection; atomistic simulation ID MOLECULAR-DYNAMICS SIMULATIONS; EMBEDDED-ATOM METHOD; DUCTILE AB Short-range dislocation interactions are inherently atomistic and can only be investigated at present by means of atomistic simulations. Large-scale molecular-dynamics (MD) simulations can provide a great deal of quantitative information about the generation, motion, and interaction of dislocations, which are processes not easily accessible at present to experiments. In this paper, we will show the necessity of atomistic simulations in investigating short-range dislocation interactions by analyzing junction formation and jog formation in the: process of dislocation intersection. (C)1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Zhou, SJ (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 10 PY 1999 VL 133 IS 1-4 BP 498 EP 504 DI 10.1016/S0167-2789(99)00074-3 PG 7 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500035 ER PT J AU Hanson, KM AF Hanson, KM TI A framework for assessing uncertainties in simulation predictions SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article; Proceedings Paper CT 18th Annual International Conference of the Center-for-Nonlinear-Studies CY MAY 11-15, 1998 CL LOS ALAMOS, NM SP Ctr Nonlinear Studies DE uncertainty analysis; error analysis; simulation code; validation; probabilistic network; model checking; adjoint differentiation ID RECONSTRUCTIONS AB A probabilistic framework is presented for assessing the uncertainties in simulation predictions that arise from model parameters derived from uncertain measurements. A probabilistic network facilitates both conceptualizing and computationally implementing an analysis of a large number of experiments in terms of many intrinsic models in a logically consistent manner. This approach permits one to improve one's knowledge about the underlying models at every level of the hierarchy of validation experiments. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hanson, KM (reprint author), Los Alamos Natl Lab, MS P940, Los Alamos, NM 87545 USA. EM kmh@lanl.gov NR 36 TC 19 Z9 21 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 SEP 10 PY 1999 VL 133 IS 1-4 BP 179 EP 188 DI 10.1016/S0167-2789(99)00090-1 PG 10 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 236JM UT WOS:000082596500014 ER PT J AU Dabiran, AM Seutter, SM Stoyanov, S Bartelt, MC Evans, JW Cohen, PI AF Dabiran, AM Seutter, SM Stoyanov, S Bartelt, MC Evans, JW Cohen, PI TI Step edge barriers versus step edge relaxation in GaAs : Sn molecular beam epitaxy SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Surface and Interface - Properties of Different Symmetry Crossing 98 (ISSI PDSC-98) CY NOV 19-21, 1998 CL TOKYO INST TECHNOL, TOKYO, JAPAN SP Minist Educ Sci Sports & Culture HO TOKYO INST TECHNOL DE doping; GaAs : Sn; molecular beam epitaxy; segregation; tin ID GROWTH; SI AB Sn strongly segregates to the surface during MBE growth. We have previously proposed a microscopic mechanism for this process in which Sn can incorporate into either a substitutional site or into a surface interstitial site. These two sites compete with each other resulting in two main effects: (1) strain causes an initial surface roughening that has a characteristic length of 1000 nm and a corrugation height of about 5 ML and (2) a subsequent enhanced layer growth mode due to the strain driven formation of small islands. As growth proceeds, 2D islands nucleate on terraces, grow in size, and then coalesce at layer completions. In situ STM and ex situ AFM on quenched GaAs:Sn surfaces show that above descending step edges during growth there are zones denuded of islands. The focus of this paper is to consider the implications and causes of these denuded zones. We examine whether these denuded zones could be due to (1) the removal of step edge barriers or (2) an inhibition of nucleation due to strain. During growth on vicinal surfaces in the presence of Sn, the specular reflection high-energy electron diffraction (RHEED) intensity oscillates at a frequency which can be up to 15% faster than the monolayer growth rate. We propose that the relative change in the apparent growth rate is proportional to the ratio of the denuded length to the terrace length. We further demonstrate that the incoherent addition of oscillations in the diffracted intensity with different frequencies gives rise to the very strong beats observed during growth. The results are compared to Monte Carlo calculations. Of the mechanisms considered we conclude that only nucleation inhibited by strain can explain the data. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. Bulgarian Acad Sci, Inst Phys Chem, BU-1113 Sofia, Bulgaria. Sandia Natl Labs, Computat Mat Sci Dept, Livermore, CA 94550 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Dabiran, AM (reprint author), Univ Minnesota, Dept Elect & Comp Engn, 200 Union St SE, Minneapolis, MN 55455 USA. NR 14 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1999 VL 438 IS 1-3 BP 131 EP 141 DI 10.1016/S0039-6028(99)00562-2 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 236ZV UT WOS:000082629900021 ER PT J AU Shimomura, M Yeom, HW Mun, BS Fadley, CS Hara, S Yoshida, S Kono, S AF Shimomura, M Yeom, HW Mun, BS Fadley, CS Hara, S Yoshida, S Kono, S TI Surface core-level shift photoelectron diffraction study of beta-SiC(001)-c(2 x 2) surface SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Surface and Interface - Properties of Different Symmetry Crossing 98 (ISSI PDSC-98) CY NOV 19-21, 1998 CL TOKYO INST TECHNOL, TOKYO, JAPAN SP Minist Educ Sci Sports & Culture HO TOKYO INST TECHNOL DE photoelectron diffraction; silicon carbide; surface relaxation and reconstruction ID BETA-SIC(100) SURFACE; RECONSTRUCTION AB Surface core-level shift energy scan photoelectron diffraction (PED) was used to distinguish the two structural models of the C-terminated beta-SiC(001)-c(2 x 2) surface under debate. An experimental FED curve of the surface C Is component is in good agreement only with the simulated curve of the unusual bridge dimer model denying the conventional dimer model. The optimized structural parameters of this bridge dimer model are 1.22, 1.84 and 2.7 Angstrom for the C-C, C-Si and Si-Si bond lengths, respectively, in agreement with recent theoretical calculations. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Sci Measurements Res Inst, Sendai, Miyagi 9808577, Japan. Univ Tokyo, Res Ctr Spectrochem, Tokyo 1130033, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Electrotech Lab, Tsukuba, Ibaraki 3058568, Japan. RP Shimomura, M (reprint author), Tohoku Univ, Sci Measurements Res Inst, Sendai, Miyagi 9808577, Japan. RI Mun, Bongjin /G-1701-2013 NR 14 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1999 VL 438 IS 1-3 BP 237 EP 241 DI 10.1016/S0039-6028(99)00575-0 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 236ZV UT WOS:000082629900034 ER PT J AU Qiu, ZQ Bader, SD AF Qiu, ZQ Bader, SD TI Symmetry breaking at magnetic surfaces and interfaces SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Surface and Interface - Properties of Different Symmetry Crossing 98 (ISSI PDSC-98) CY NOV 19-21, 1998 CL TOKYO INST TECHNOL, TOKYO, JAPAN SP Minist Educ Sci Sports & Culture HO TOKYO INST TECHNOL DE copper; iron; magnetism; symmetry breaking; two-dimensional ID EPITAXIAL FE FILMS; SPIN-POLARIZED PHOTOEMISSION; STRIPE DOMAIN-STRUCTURES; THIN FERROMAGNETIC FILM; PHASE-TRANSITION; ULTRATHIN FILMS; ANISOTROPY; AG(001); BEHAVIOR; SUPERLATTICES AB Examples are presented of how symmetry breaking enters into consideration of the physical properties of magnetic surfaces and ultrathin films. The role of magnetic anisotropy is discussed with a view to understanding: (i) the existence of two-dimensional magnetic long-ranged order at finite temperature; (ii) magnetization scaling behavior at the Curie transition; (iii) the two-dimensional spin reorientation transition; and (iv) step-induced magnetic behavior. Experimental examples cited include ultrathin magnetic Fe and Co overlayer and wedge structures grown onto single crystal substrates that are either flat or curved to produce vicinal surfaces with a continuous gradient in the step density. Also included is an example of an atomically flat manganite intergrowth that appears as a stacking fault in a bulk single crystal of a naturally layered structure. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Bader, SD (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Qiu, Zi Qiang/O-4421-2016 OI Qiu, Zi Qiang/0000-0003-0680-0714 NR 45 TC 14 Z9 14 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1999 VL 438 IS 1-3 BP 319 EP 328 DI 10.1016/S0039-6028(99)00597-X PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 236ZV UT WOS:000082629900045 ER PT J AU Mook, HA Dogan, F AF Mook, HA Dogan, F TI Charge fluctuations in YBa2Cu3O7-x high-temperature superconductors SO NATURE LA English DT Article ID INCOMMENSURATE MAGNETIC FLUCTUATIONS; INELASTIC NEUTRON-SCATTERING; SPIN FLUCTUATIONS; FERMI-LIQUID; APPROXIMATION; OXIDES; ORDER; HOLES; NMR AB Understanding the behaviour of the electrons in the high-temperature copper oxide superconductors remains a challenging problem. An important class of models(1-5) argues that the distribution of electronic charge and spin is not homogeneous: rather, spin and charge adopt a dynamic arrangement in which the spins on the copper form antiferromagnetic stripes, separated by domain walls containing the charge(1-5). The dynamic behaviour of the spins has been extensively studied by neutron scattering, and recent results(6) have shown that the low-frequency fluctuations for different classes of materials display a universal spatial behaviour that is consistent with the stripe picture. But arguments for the existence of the stripe phases are difficult to sustain without a demonstration that charge is distributed in the domain walls. Here we report phonon measurements for the YBa2Cu3O7-x, high-temperature superconductors, which reveal the presence of charge fluctuations. The inferred periodicity is that expected if the charge is located in the domain walls separating the spin stripes. Our results therefore provide strong support for the existence of a dynamic stripe phase in the high-temperature superconductors. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. RP Mook, HA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 29 TC 103 Z9 104 U1 0 U2 8 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 9 PY 1999 VL 401 IS 6749 BP 145 EP 147 DI 10.1038/43629 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 234AF UT WOS:000082458800047 ER PT J AU Csaki, C Graesser, M Kolda, C Terning, J AF Csaki, C Graesser, M Kolda, C Terning, J TI Cosmology of one extra dimension with localized gravity SO PHYSICS LETTERS B LA English DT Article ID TEV; MILLIMETER; CONSTANT AB We examine the cosmology of the two recently proposed scenarios for a five dimensional universe with localized gravity. We find that the scenario with a non-compact fifth dimension is potentially viable, while the scenario which might solve the hierarchy problem predicts a contracting universe, leading to a variety of cosmological problems. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Theoret Phys Grp, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Csaki, C (reprint author), Univ Calif Berkeley, Theoret Phys Grp, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. OI Terning, John/0000-0003-1367-0575 NR 45 TC 449 Z9 451 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 SEP 9 PY 1999 VL 462 IS 1-2 BP 34 EP 40 DI 10.1016/S0370-2693(99)00896-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 241EM UT WOS:000082869800006 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Devmal, S Fernandez, A Fox, GF Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B Magnin, J MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Devmal, S Fernandez, A Fox, GF Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B Magnin, J MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C CA E791 Collaboration TI Total forward and differential cross sections of neutral D mesons produced in 500 GeV/c pi(-)-nucleon interactions SO PHYSICS LETTERS B LA English DT Article ID TRANSVERSE-MOMENTUM DEPENDENCE; HIGH-ENERGY PHOTOPRODUCTION; PARTON DISTRIBUTIONS; P-INTERACTIONS; D(0),(D)OVER-BAR(0) PRODUCTION; NUCLEON-INTERACTIONS; FEYNMAN-X; DRELL-YAN; CHARM; ASYMMETRIES AB We measure the neutral D total forward cross section and the differential cross sections as functions of Feynman-x (x(F)) and transverse momentum squared for 500 GeV/c pi(+)-nucleon interactions. The results are obtained from 88990 +/- 460 reconstructed neutral D mesons from Fermilab experiment E791 using the decay channels D-0-->K(-)pi(+) and D-0-->K(-)pi(+)pi(-)pi(+) (and charge conjugates). We extract fit parameters from the differential cross sections and provide the first direct measurement of the turnover point in the x(F) distribution, 0.0131 +/- 0.0038. We measure an absolute D-0 + (D) over bar(0) (x(F) > 0) cross section of 15.4(-2.3)(+1.8) mu barn/nucleon (assuming a linear A dependence). The differential and total forward cross sections are compared to theoretical predictions and to results of previous experiments. (C) 1999 Published by EIsevier Science B.V. All rights reserved. C1 Univ Mississippi, University, MS 38677 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. CINVESTAV, Mexico City 07000, DF, Mexico. Fermilab Astrophys Ctr, Batavia, IL 60510 USA. IIT, Chicago, IL 60616 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Massachusetts, Amherst, MA 01003 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Autonoma Puebla, Mexico City, DF, Mexico. Univ S Carolina, Columbia, SC 29208 USA. Stanford Univ, Stanford, CA 94305 USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. Tufts Univ, Medford, MA 02155 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Aitala, EM (reprint author), Univ Mississippi, University, MS 38677 USA. RI Anjos, Joao/C-8335-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X NR 39 TC 13 Z9 13 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 SEP 9 PY 1999 VL 462 IS 1-2 BP 225 EP 236 DI 10.1016/S0370-2693(99)00900-4 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 241EM UT WOS:000082869800033 ER PT J AU Hoyt, JJ Sadigh, B Asta, M Foiles, SM AF Hoyt, JJ Sadigh, B Asta, M Foiles, SM TI Kinetic phase field parameters for the Cu-Ni system derived from atomistic computations SO ACTA MATERIALIA LA English DT Article DE solidification; copper; nickel; theory and modeling (kinetics, transport, diffusion) ID EMBEDDED-ATOM-METHOD; LIQUID TRANSITION-METALS; COMPUTER-SIMULATION; MODEL; GROWTH; ALLOYS; TRANSPORT; EVOLUTION AB In the phase field model of binary solidification the mobility terms which appear in the governing rate equations can be estimated from the liquid diffusion coefficients of the pure elements and the velocity of the solid-liquid interface as a function of undercooling. Molecular dynamics simulations utilizing embedded atom potentials have been employed to compute the liquid diffusivities for pure Cu and Ni in the vicinity of their melting points. In both cases the diffusion coefficient is found to vary linearly with temperature and the results are in good agreement with experimental values which are available for Cu. The simulations were also employed to obtain the boundary velocities in three different low index growth directions. The results for Cu and Ni were found to be very similar, with the slope of the velocity-undercooling curve at small undercoolings varying in the range 45-18 cm/s/K. Anisotropy in the growth behavior was observed with V-100 > V-110 > V-111. The solid-liquid interface velocities were found to be a factor of 4-5 less than the theoretical upper limit derived previously. Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Sandia Natl Labs, Computat Mat Sci Dept, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hoyt, JJ (reprint author), Sandia Natl Labs, Computat Mat Sci Dept, Livermore, CA 94550 USA. OI Foiles, Stephen/0000-0002-1907-454X NR 32 TC 68 Z9 68 U1 0 U2 15 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 SEP 8 PY 1999 VL 47 IS 11 BP 3181 EP 3187 DI 10.1016/S1359-6454(99)00189-5 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 237ZQ UT WOS:000082686800006 ER PT J AU Feller, D AF Feller, D TI A comparison of techniques for predicting higher order correlation effects: Diatomic dissociation energies SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FULL CONFIGURATION-INTERACTION; MOLECULAR WAVE-FUNCTIONS; BASIS-SET CONVERGENCE; BENCHMARK CALCULATIONS; ELECTRONIC-STRUCTURE; SYSTEMATIC SEQUENCES; PERTURBATION-THEORY; 2ND-ROW COMPOUNDS; GAUSSIAN-1 THEORY; INTERACTION LIMIT AB The impact of higher-order correlation effects on dissociation energies was measured for three diatomic molecules (HF, N-2, and CO) using standard coupled cluster theory, including a perturbative treatment of triple excitations, as the baseline for comparison. Among the higher-order methods examined were two variations of coupled cluster theory [CCSDT and CCSD(TQ)] and two approximations to full configuration interaction. Basis sets were chosen from the correlation-consistent family of basis sets, with the largest being the aug-cc-pVQZ set. Polarized valence double zeta quality basis sets were found to yield corrections that differed substantially from larger basis set results. At the double zeta level, higher order corrections increased the binding energies, whereas calculations with triple and quadruple zeta basis sets gave the opposite effect. Although the absolute magnitude of the higher-order corrections was small for these diatomics, they were nonetheless significant in light of a target accuracy of +/- 1 kcal/mol. Among molecules composed of first-through-third period elements, such as those in the G2 and G2/97 collections, the contribution to D-0 from higher order correlation effects could easily exceed 1 kcal/mol. If further studies corroborate the present findings, CCSDT should provide an effective method of determining the magnitude of the higher-order correction, at least when basis sets of triple zeta or better quality can be used. CCSD(TQ) often overestimated the higher order correction, sometimes exceeding the estimated full configuration interaction result by a factor of three. (C) 1999 American Institute of Physics. [S0021-9606(99)30134-3]. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Environm Mol Sci Lab, MS K8-91,POB 999, Richland, WA 99352 USA. NR 66 TC 79 Z9 80 U1 0 U2 1 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 SEP 8 PY 1999 VL 111 IS 10 BP 4373 EP 4382 DI 10.1063/1.479202 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500003 ER PT J AU Borve, KJ Saethre, LJ Bozek, JD True, J Thomas, TD AF Borve, KJ Saethre, LJ Bozek, JD True, J Thomas, TD TI Molecular-field splitting and vibrational structure in the phosphorus 2p photoelectron spectrum of PF3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EQUIVALENT-CORES APPROXIMATION; ANO BASIS-SETS; WAVE-FUNCTIONS; SPECTROSCOPY; FREQUENCIES; ENERGIES; ATOMS; H2S AB The experimental phosphorus 2p spectrum of PF3 shows vibrational structure corresponding to the symmetric phosphorus-fluorine stretching mode, with a fundamental frequency of 121.7 meV. In addition, the spectrum shows that the 2p(3/2) peak is a doublet split by 146 meV. This molecular-field splitting arises because the anisotropic molecular environment lifts the threefold degeneracy of the 2p orbitals. The observed vibrational structure is compared with that predicted by theory, either treating the core hole explicitly or using the equivalent-cores approximation to simulate the effects of the core hole. Ab initio calculations of the molecular-field splitting that include core-valence electron correlation predict a value in good agreement with the experimental value. (C) 1999 American Institute of Physics. [S0021-9606(99)00634-0]. C1 Univ Bergen, Dept Chem, N-5007 Bergen, Norway. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. RP Borve, KJ (reprint author), Univ Bergen, Dept Chem, Allegt 41, N-5007 Bergen, Norway. RI Bozek, John/E-4689-2010; Borve, Knut/I-5934-2012; Bozek, John/E-9260-2010 OI Borve, Knut/0000-0002-5782-8963; Bozek, John/0000-0001-7486-7238 NR 28 TC 15 Z9 15 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1999 VL 111 IS 10 BP 4472 EP 4477 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500014 ER PT J AU Wang, XB Wang, LS AF Wang, XB Wang, LS TI Photodetachment of free hexahalogenometallate doubly charged anions in the gas phase: [ML6](2-), (M=Re, Os, Ir, Pt; L=Cl and Br) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTROSPRAY MASS-SPECTROMETRY; VIBRATIONAL SPECTROSCOPY; CONSTRUCTION PRINCIPLE; CARBON CLUSTERS; NEGATIVE-IONS; PHOTOELECTRON-SPECTROSCOPY; MOLECULAR-SYSTEMS; COULOMBIC ENERGY; CLOSED-SHELL; COMPLEXES AB We report the first observation and photodetachment photoelectron spectroscopic study of a series of hexahalogenometallates dianions MCl62- (M=Re, Os, Ir, and Pt) and MBr62- (M=Re, Ir, and Pt) in the gas phase. All of these species were found to be stable as free gaseous doubly charged anions. Photoelectron spectra of all the dianions were obtained at several detachment photon energies. The photon-energy-dependent spectra clearly revealed the dianion nature of these species and allowed the repulsive Coulomb barriers to be estimated. The binding energies of the second excess electron in MCl62- (M=Re, Os, Ir, Pt) were determined to be 0.46 (5), 0.46 (5), 0.82 (5), and 1.58 (5) eV, respectively, and those in MBr62- (M=Re, Ir, Pt) to be 0.76 (6), 0.96 (6), and 1.52 (6) eV, respectively. A wealth of electronic structure information about these metal complexes were obtained and low-lying and highly-excited electronic states of the corresponding singly charged anions were observed. Detachment from metal d orbitals or ligand orbitals were observed and could be clearly distinguished; detachments from the metal d-orbitals all occur at low binding energies whereas those from the ligand-dominated orbitals all take place at rather high binding energies. We also found a remarkable correlation between electron affinities measured in vacuo and the redox potentials obtained in the solution phase of these species. (C) 1999 American Institute of Physics. [S0021-9606(99)00234-2]. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Wang, XB (reprint author), Washington State Univ, Dept Phys, Richland, WA 99352 USA. NR 83 TC 72 Z9 72 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1999 VL 111 IS 10 BP 4497 EP 4509 DI 10.1063/1.479213 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500017 ER PT J AU Desfrancois, C Periquet, V Lyapustina, SA Lippa, TP Robinson, DW Bowen, KH Nonaka, H Compton, RN AF Desfrancois, C Periquet, V Lyapustina, SA Lippa, TP Robinson, DW Bowen, KH Nonaka, H Compton, RN TI Electron binding to valence and multipole states of molecules: Nitrobenzene, para- and meta-dinitrobenzenes SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ION PHOTOELECTRON-SPECTROSCOPY; EXCITED RYDBERG ATOMS; GROUND-STATE; POLYATOMIC-MOLECULES; RATE CONSTANTS; BOUND ANIONS; DIPOLE; QUADRUPOLE; AFFINITIES; CS2 AB Nitrobenzene anions (NB-) in both valence and dipole bound states are examined using laser (photodetachment) photoelectron and Rydberg electron transfer (RET) spectroscopies. Photoelectron spectroscopy of the valence NB- anion yields a valence (adiabatic) electron affinity of 1.00 +/- 0.01 eV. The reaction rates for charge transfer between atoms of cesium and xenon in high Rydberg states [Cs(ns,nd) and Xe(nf )] and NB exhibit a prominent peak in their n-dependencies consistent with the formation of a dipole bound anion having an electron affinity of 28 meV. Para-dinitrobenzene (pDNB) has a zero dipole moment and a large quadrupole moment. RET studies with pDNB show a complex n-dependence. The rate of formation of pDNB(-) ions exhibits a broad peak at low n-values and a second very broad feature extending to large n-values. The peak at low n is tentatively attributed to charge exchange into a quadrupole bound state (EA(qb)=25 meV). The absence of field-detachment for these ions suggests that if these are in a quadrupole bound state they are strongly coupled to the valence state. Meta-dinitrobenzene (mDNB) has a large dipole moment and a small quadrupole moment. The observation of a weak but narrow peak at a low n-value in the RET measurement is consistent with electron attachment into a primarily dipole bound state (EA(db)=68 meV) which is also strongly coupled to the valence state. (C) 1999 American Institute of Physics. [S0021-9606(99)30534-1]. C1 Univ Paris 13, Inst Galilee, Phys Lasers Lab, F-93430 Villetaneuse, France. Johns Hopkins Univ, Dept Chem, Baltimore, MD 21218 USA. Electrotech Lab, Div Mat Sci, Tsukuba, Ibaraki 305, Japan. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Chem Phys Sect, Oak Ridge, TN 37830 USA. RP Desfrancois, C (reprint author), Univ Paris 13, Inst Galilee, Phys Lasers Lab, F-93430 Villetaneuse, France. RI Desfrancois, Charles/M-6741-2015 OI Desfrancois, Charles/0000-0003-2512-4387 NR 47 TC 63 Z9 63 U1 2 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1999 VL 111 IS 10 BP 4569 EP 4576 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500023 ER PT J AU Kathmann, SM Schenter, GK Garrett, BC AF Kathmann, SM Schenter, GK Garrett, BC TI Dynamical nucleation theory: Calculation of condensation rate constants for small water clusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VAPOR-PHASE NUCLEATION; MONTE-CARLO SIMULATION; TRANSITION-STATE THEORY; MOLECULAR THEORY; PHYSICAL CLUSTERS; HOMOGENEOUS NUCLEATION; DROP; LIQUID; MODEL AB In previous work we began the description of a molecular theory of homogeneous vapor-to-liquid nucleation based on the kinetics of cluster formation and decomposition. In this work we focused on a new theoretical approach to calculating rate constants for evaporation of molecules from clusters. In the present work, we present a molecular theory for calculating condensation rate constants that are consistent with the evaporation rate constants. The new method, which uses variational transition state theory (VTST), provides an expression for the evaporation rate constant that is proportional to the derivative of the Helmholtz free energy for cluster formation with respect to the radius of the spherical volume constraining the cluster. Furthermore, the theory provides a physically justified procedure for selecting a unique value of the radius of the spherical volume for each i-molecule cluster. Since VTST obeys detailed balance, condensation rate constants can be obtained from the evaporation rate constants and the corresponding equilibrium constants. In the present work, we provide a theoretical approach to obtain the equilibrium constants that are consistent with the evaporation rate constants. Monte Carlo methods are presented for calculating the dependence of the Helmholtz free energy of cluster formation on the radius of the constraining volume, which are needed for the evaporation rate constants. In addition, Monte Carlo methods are presented for calculating the relative differences in Helmholtz free energies for clusters of different sizes, which are needed for the equilibrium constants and condensation rate constants. The volume dependent Helmholtz free energies for the water dimer up to the decamer are calculated at 243 K. (C) 1999 American Institute of Physics. [S0021-9606(99)51434-7]. C1 Pacific NW Lab, Environm Mol Sci lab, Richland, WA 99352 USA. RP Kathmann, SM (reprint author), Pacific NW Lab, Environm Mol Sci lab, POB 999, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 42 TC 45 Z9 45 U1 1 U2 21 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1999 VL 111 IS 10 BP 4688 EP 4697 DI 10.1063/1.479230 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500036 ER PT J AU Melnichenko, YB Wignall, GD Compton, RN Bakale, G AF Melnichenko, YB Wignall, GD Compton, RN Bakale, G TI Characterization of fullerenes and fullerene derivatives by small-angle neutron scattering and transmission measurements SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID C-60; CS2 AB Small-angle neutron scattering (SANS) has been shown to be an appropriate technique for the structural characterization of fullerenes in solvents with strong SANS contrast (e.g., CS2). The dimensions of C-60, C-70, and C-84 moieties derived from neutron scattering via standard Guinier analysis are typically similar to 8% higher than calculated from the atomic coordinates. However, when the SANS data are fitted to an appropriate model form factor, there is good agreement between the measured and calculated values and the results are independent of the fullerene concentration within the experimental errors. Deuterated solvents (e.g., toluene-d(8)) have a high scattering length density (SLD), which is close to that of C-60, C-70, and C-84, so there is virtually no SANS contrast with the solvent and these particles are practically "invisible" in such media. Conversely, the negative scattering length of hydrogen lowers the SLD, giving strong contrast with toluene-d(8) and SANS may therefore be used to study the size and shapes of buckyballs modified with H-1-containing materials. These may also be studied via neutron transmission measurements and this paper describes complementary studies of cyclohexane-substituted fullerenes. (C) 1999 American Institute of Physics. [S0021-9606(99)70234-5]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Case Western Reserve Univ, Div Radiat Biol, Cleveland, OH 44106 USA. RP Melnichenko, YB (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. OI Wignall, George/0000-0002-3876-3244 NR 19 TC 21 Z9 21 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1999 VL 111 IS 10 BP 4724 EP 4728 DI 10.1063/1.479234 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500040 ER PT J AU Silbert, LE Farr, RS Melrose, JR Ball, RC AF Silbert, LE Farr, RS Melrose, JR Ball, RC TI Stress distributions in flowing aggregated colloidal suspensions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DYNAMIC SIMULATION; FORCE FLUCTUATIONS; ELASTIC PROPERTIES; GRANULAR SYSTEMS; BEAD PACKS; PAIR-DRAG; MODEL; RHEOLOGY; PARTICLES; DISPERSIONS AB Simulations of the flow of concentrated aggregated colloidal systems, at the particulate level, are used to investigate the distribution of stresses in the shear-thinning regime. It is found that the distribution of shear stress carried by interparticle bonds decays approximately exponentially at large stresses, but with a double-exponential distribution for values of positive stress. The microstructural mechanisms associated with large stresses are manifested in clusters which dominate the positive contribution to the stress in the system. Towards the end of shear thinning the highest forces occur along bonds defining rods of particles aligned approximately along the flow-compression direction. We propose that the rheology of such systems is determined by a rupture-reformation process of these clusters of stress concentration during the flow. The aggregation forces play the role of enhancing such stress concentration by stabilizing clusters against buckling. (C) 1999 American Institute of Physics. [S0021-9606(99)51934-X]. C1 Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87185 USA. Unilever Res, Bedford MK44 11Q, England. Univ Cambridge, Cavendish Lab, Polymers & Colloids Grp, Cambridge CB3 0HE, England. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RP Silbert, LE (reprint author), Sandia Natl Labs, Adv Mat Lab, POB 5800, Albuquerque, NM 87185 USA. RI Farr, Robert/C-8116-2009; OI Farr, Robert/0000-0002-0105-6976 NR 50 TC 19 Z9 19 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1999 VL 111 IS 10 BP 4780 EP 4789 DI 10.1063/1.479241 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 229YC UT WOS:000082222500047 ER PT J AU Gao, HR Angelici, RJ AF Gao, HR Angelici, RJ TI Combined homogeneous and heterogeneous catalysts. Rhodium carbonyl thiolate complexes tethered on silica-supported metal heterogeneous catalysts: olefin hydroformylation and arene hydrogenation SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE rhodium carbonyl thiolate complexes; supported metal catalysts; TCSM; tethered complex catalysts; silica; palladium; nickel; gold; hydroformylation; toluene hydrogenation ID ASYMMETRIC HYDROGENATION; CRYSTAL-STRUCTURE; LIGANDS; SPILLOVER; ZEOLITES; RH AB The rhodium carbonyl thiolate complex, Rh-2[mu-S(CH2)(3)Si(OCH3)(3)](2)(CO)(4) (Rh-S) was tethered to phosphine-modified Pd-SiO2 (P-(Pd-SiO2)), which was prepared by tethering the phosphine ligand Ph2P(CH2),Si(OC2H5)(3) to Pd-SiO2, to give the tethered complex catalyst Rh-S/P-(Pd-SiO2). Also, the phosphine-substituted Rh-2[mu-S(CH2)(3)-Si(OCH3)(3)](2)[Ph2P(CH2)(3)Si(OC2 H-5)(3)](2)(CO)(2) (Rh-S-P) was tethered to several silica-supported metal heterogeneous catalysts M-SiO2 (M = Pd, Pt, Ru, Ir) to give Rh-S-P /M-SiO2. These complex catalysts, consisting of a tethered complex on a supported-metal (TCSM), were used to catalyze the hydroformylation of olefins and the hydrogenation of toluene under atmospheric pressure. In the presence of phosphorus donor-ligands, all the TCSM catalysts are active for the hydroformylation of olefins under the mild conditions of 60 degrees C and 1 atm of H-2 and CO (1:1). The most active catalysts, Rh-S/P-(Pd-SiO2) and Rh-S-P/Pd-SiO2, give maximum ToF values of 1.04 and 0.88 (mol aldehyde/mol Rh min), respectively, and TO values of 905 and 703 (mol aldehyde/mol Rh) during 22.5 h and 23.5 h in the hydroformylation of 1-octene. The Rh-S-P/Pd-SiO2 similar to PPh3 catalyst system maintains its activity through three cycles and 68 h to give a total turnover of 2118 mol aldehyde/mol Ph. These activities are higher than those of the homogeneous rhodium thiolate complex catalyst (Rh-S-P) and the rhodium thiolate complex catalysts tethered on just SiO2(Rh-S/P-SiO2 and Rh-S-P/SiO2). The effects of the phosphorus ligand and PR3/Rh mole ratio on the hydroformylation rates, conversions, and chemo- and regioselectivities for aldehyde were also investigated. The Rh-S/P-(Pd-SiO2) and Rh-S-P(Pd-SiO2) catalysts are also active for the hydrogenation of toluene under dhe mild conditions of 40 degrees C and 1 atm of H-2; they are much more active than the homogeneous rhodium thiolate complex catalyst Rh-S-P, the simple silica-supported heterogeneous palladium catalyst (Pd-SiO2) and the rhodium thiolate complex catalysts tethered on just SiO2(Rh-S/P-SiO2 and Rh-S-P/SiO2). The synergistic advantages of the two components (tethered complex and supported metal) of the TCSM catalysts are greater for the hydrogenation of toluene than for the hydroformylation of 1-octene. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Iowa State Univ, Dept Chem, Gilman Hall, Ames, IA 50011 USA. EM angelici@iastate.edu NR 40 TC 31 Z9 33 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 EI 1873-314X J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD SEP 8 PY 1999 VL 145 IS 1-2 BP 83 EP 94 DI 10.1016/S1381-1169(99)00096-5 PG 12 WC Chemistry, Physical SC Chemistry GA 253EN UT WOS:000083543800007 ER PT J AU Gibbons, BJ Trolier-McKinstry, S AF Gibbons, BJ Trolier-McKinstry, S TI The sensitivity limits of spectroscopic ellipsometry to oxygen content in YBa2Cu3O7-delta thin films SO THIN SOLID FILMS LA English DT Article DE spectroscopic ellipsometry; YBa2Cu3O7-delta; oxygen content ID JOSEPHSON-JUNCTIONS; EDGE JUNCTIONS; HIGH-TC; ALXGA1-XAS; DEFICIENCY; SUBSTRATE; GROWTH AB The limits for the sensitivity of spectroscopic ellipsometry (SE) to the presence of near-surface gradations of the oxygen content in YBa2Cu3O7-delta (YBCO) thin films have been investigated. Using an ellipsometric data modelling program, SE spectra were generated for films with fixed geometries and varying concentration gradients of oxygen. By comparing these spectra, the sensitivity limits of SE to small changes in the diffused depth and/or the surface concentration of oxygen (c(s)) were determined. For c-axis oriented films, it was found that the oxygen content can, in principle, be determined to within one unit cell of YBCO, even when the profile is graded. Also, the minimum detectable change in the surface oxygen concentration (c(s)) was calculated to be 2-3%, depending on the starting c(s). Similar calculations for YBCO layers buried under a 4 nm layer of metallic SrRuO3 (i.e. in a superconductor normal metal junction) showed small changes in these sensitivities. Calculations for a-axis oriented films showed that changes as small as 10 Angstrom in the diffused depth were detectable for both buried and surface layers. The minimum detectable change in c(s) for a-axis films was found to be 2-8%. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Penn State Univ, University Pk, PA 16802 USA. RP Gibbons, BJ (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 32 TC 5 Z9 5 U1 1 U2 12 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 8 PY 1999 VL 352 IS 1-2 BP 205 EP 212 DI 10.1016/S0040-6090(99)00279-5 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 238KN UT WOS:000082709600033 ER PT J AU Cabelli, DE Guan, Y Leveque, V Hearn, AS Tainer, JA Nick, HS Silverman, DN AF Cabelli, DE Guan, Y Leveque, V Hearn, AS Tainer, JA Nick, HS Silverman, DN TI Role of tryptophan 161 in catalysis by human manganese superoxide dismutase SO BIOCHEMISTRY LA English DT Article ID ESCHERICHIA-COLI; BACILLUS-STEAROTHERMOPHILUS; THERMUS-THERMOPHILUS; PULSE-RADIOLYSIS; ACTIVE-SITE; TYROSINE-34; ENZYME; MUTANTS AB Tryptophan 161 is a highly conserved residue that forms a hydrophobic side of the active site cavity of manganese superoxide dismutase (MnSOD), with its indole ring adjacent to and about 5 Angstrom from the manganese. We have made a mutant containing the conservative replacement Trp 161 --> Phe in human MnSOD (W161F MnSOD), determined its crystal structure, and measured the catalysis of the resulting mutant using pulse radiolysis to produce O-2(.-). In the structure of W161F MnSOD the phenyl side chain of Phe 161 superimposes on the indole ring of Trp 161 in the wild type. However, in the mutant, the hydroxyl side chain of Tyr 34 is 3.9 iq from the manganese, closer by 1.2 Angstrom than in the wild type. The tryptophan in MnSOD is not essential for the half-cycle of catalytic activity involving reduction of the manganese: the mutant W161F MnSOD had k(cat)/K-m at 2.5 x 10(8) M-1 s(-1), reduced only 3-fold compared with wild type. However, this mutant exhibited a strong product inhibition with a zero-order region of superoxide decay slower by 10-fold compared with wild type. The visible absorption spectrum of W161F MnSOD in the inhibited state was very similar to that observed for the inhibited wild-type enzyme. The appearance of the inhibited form required reaction of 2 molar equiv of O-2(.-) with W161F Mn(III)SOD, one to form the reduced state of the metal and the second to form the inhibited complex, confirming that the inhibited complex requires reaction of O-2(.-) With the reduced form of the enzyme. This work suggests that a significant role of Trp 161 in the active site is to promote the dissociation of product peroxide, perhaps in part through its effect on the orientation of Tyr 34. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Univ Florida, Dept Pharmacol, Gainesville, FL 32610 USA. Univ Florida, Dept Biochem, Gainesville, FL 32610 USA. Univ Florida, Dept Neurosci, Gainesville, FL 32610 USA. RP Silverman, DN (reprint author), Univ Florida, Ctr Hlth, Box 100267, Gainesville, FL 32610 USA. FU NIGMS NIH HHS [GM 48495, GM 54903] NR 27 TC 31 Z9 32 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 7 PY 1999 VL 38 IS 36 BP 11686 EP 11692 DI 10.1021/bi9909142 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 239FC UT WOS:000082757300013 PM 10512624 ER PT J AU Cheng, TY Szalda, DJ Bullock, RM AF Cheng, TY Szalda, DJ Bullock, RM TI An uncommon bonding mode of a familiar ligand: a molybdenum complex with a four-electron donor chelating eta(3)-PPh3 ligand, and its structural determination using synchrotron radiation SO CHEMICAL COMMUNICATIONS LA English DT Article ID WEAKLY COORDINATING ANIONS; ORGANOMETALLIC LEWIS-ACIDS; X-RAY STRUCTURE; MEO-BIPHEP; NMR; CRYSTAL AB A crystallographic study using synchrotron radiation shows that a C=C bond of one phenyl group of a PPh3 ligand bonds to Mo in [Cp(CO)(2)(PPh3)Mo](+), resulting in an unusual bonding mode in which PPh3 functions as a chelating four-electron donor ligand. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM bullock@bnl.gov RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 24 TC 19 Z9 19 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 EI 1364-548X J9 CHEM COMMUN JI Chem. Commun. PD SEP 7 PY 1999 IS 17 BP 1629 EP 1630 DI 10.1039/a905092b PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 228HN UT WOS:000082131200008 ER PT J AU Sachleben, RA Urvoas, A Bryan, JC Haverlock, TJ Hay, BP Moyer, BA AF Sachleben, RA Urvoas, A Bryan, JC Haverlock, TJ Hay, BP Moyer, BA TI Dideoxygenated calix[4]arene crown-6 ethers enhanced selectivity for caesium over potassium and rubidium SO CHEMICAL COMMUNICATIONS LA English DT Article ID SUPPORTED LIQUID MEMBRANES; CONFORMATION; COMPLEXATION; CESIUM; CALIXCROWNS; CONFORMERS; IONOPHORES; CATIONS; WASTE AB Calix[4]arene crown-6 ethers derived from dideoxygenated calix[4]arene exhibit enhanced extraction selectivity for caesium over potassium; the crystal stucture of the uncomplexed calix[4]arene monobenzocrown-6 ether exists in the 1,3-alt conformation in the solid state. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sachleben, RA (reprint author), Oak Ridge Natl Lab, POB 2008,MS-6119-4500S, Oak Ridge, TN 37831 USA. RI Solominow, Sonia/A-4021-2008; Moyer, Bruce/L-2744-2016 OI Moyer, Bruce/0000-0001-7484-6277 NR 25 TC 43 Z9 44 U1 0 U2 8 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD SEP 7 PY 1999 IS 17 BP 1751 EP 1752 DI 10.1039/a905682c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 228HN UT WOS:000082131200069 ER PT J AU Cao, H Yuan, JP Zhang, R Huang, CM He, Y Sandreczki, TC Jean, YC Nielsen, B Suzuki, R Ohdaira, T AF Cao, H Yuan, JP Zhang, R Huang, CM He, Y Sandreczki, TC Jean, YC Nielsen, B Suzuki, R Ohdaira, T TI Degradation of polymer coating systems studied by positron annihilation spectroscopy. 3. Wavelength dependence of UV irradiation effect SO MACROMOLECULES LA English DT Article ID FREE-VOLUME; THIN-FILMS; TRANSITION; SURFACES; BEAMS AB Photodegradation of a polyurethane coating induced by accelerated UV irradiation is studied using three different light sources: 340 nm UVA, 313 nm UVB, and Xe lamps. Doppler-broadened energy spectra (DBES) and positron annihilation lifetime (PAL) are measured as a function of incident positron energy (0-30 keV) and of irradiation time (0-800 h). The photodegradation of the coating is characterized in terms of subnanometer defect changes. Significant variations of S parameter, orthopositronium lifetime, intensity, and lifetime distribution are observed as a function of depth and of exposure time. These results indicate a decrease of free volume and holes at the atomic level during the degradation process. The UV irradiation at 313 nm shows a significant effect compared with that at 340 nm on the photodegradation: (1) the magnitude of S reduction increases a factor of 2 near the surface; (2) the photodegradation rate increases similar to 25 times near the surface; (3) the irradiation effect attenuates with depth, and a larger extinction coefficient is observed with shorter wavelength UV irradiation. The observed effect by Xe light irradiation is the strongest among these three light sources. Enhanced degradation at shorter wavelengths is also indicated by increased free radical production, as observed by electron spin resonance spectroscopy. C1 Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. RP Sandreczki, TC (reprint author), Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 17 TC 30 Z9 32 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 7 PY 1999 VL 32 IS 18 BP 5925 EP 5933 DI 10.1021/ma990513u PG 9 WC Polymer Science SC Polymer Science GA 235AF UT WOS:000082516000030 ER PT J AU Fair, JM Hansen, ES Ricklefs, RE AF Fair, JM Hansen, ES Ricklefs, RE TI Growth, developmental stability and immune response in juvenile Japanese quails (Coturnix coturnix japonica) SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE Japanese quail; developmental stability; ELISA; fluctuating asymmetry; immunocompetence; phytohaemagglutinin ID FLUCTUATING ASYMMETRY; AMERICAN KESTRELS; INDICATOR; CHICKENS; DEPRESSION; PATTERNS; PROTEIN; PLASMA; LIFE; CELL AB Stresses are environmental factors which restrict growth or cause a potentially adverse change in an organism. The exposure of developing organisms to environmental stresses may have several physiological consequences including a decrease in immunocompetence. However, mounting an immune response against a foreign antigen may in itself constitute a cost for developing organisms. This cost has potentially long-term consequences for adult function and fitness. This study examines the growth and developmental stability of Japanese quail chicks challenged by three non-pathogenic antigens: sheep red blood cells, which assess T-cell-dependent immune responses, and Mycoplasma synoviae and Newcastle disease virus, which assess T-cell-independent responses. Increases in both body mass and wing length were significantly reduced in antigen-challenged birds compared to control birds. Fluctuating asymmetry (FA) in the masses of primary feathers increased from the innermost (1) to the outermost (10) position on the wing. In addition, antigen challenge by M. synoviae and sheep red blood cells was associated with an increase in FA. The cell-mediated response measured by reaction to phytohaemagglutinin was significantly depressed in hi. synoviae-challenged birds. White blood cell counts, except for monocytes, were elevated in response to all three antigen treatments. Total plasma protein and haematocrit also differed between treatments but exhibited no clear relationship to antigen challenge. Immune responses clearly impose a stress on developing chicks. Additional research will be required to determine the long-term consequences of developmental stress and assess the selective forces that influence the strength of the immune responses of chicks. C1 Univ Missouri, Dept Biol, St Louis, MO 63121 USA. Univ Calif Los Alamos Natl Lab, Environm Sci Grp, Los Alamos, NM 87545 USA. RP Fair, JM (reprint author), Univ Missouri, Dept Biol, 8001 Nat Bridge Rd, St Louis, MO 63121 USA. EM jmfair@lanl.gov NR 33 TC 94 Z9 98 U1 1 U2 18 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD SEP 7 PY 1999 VL 266 IS 1430 BP 1735 EP 1742 PG 8 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 241DJ UT WOS:000082866800004 PM 10518322 ER PT J AU Vogelgesang, R Liang, JJ Wagner, V Lugauer, HJ Geurts, J Waag, A Landwehr, G AF Vogelgesang, R Liang, JJ Wagner, V Lugauer, HJ Geurts, J Waag, A Landwehr, G TI Wavelength-dependent optical degradation of green II-VI laser diodes SO APPLIED PHYSICS LETTERS LA English DT Article ID ZNSE AB In this letter we report on optical degradation studies on BeMgZnSe separate confinement quantum well laser structures for the blue-green spectral region. The wavelength of the incident light has been tuned from 3.81 down to 2.10 eV, corresponding to an energy range from above the band gap of the cladding layers down to below the band gap of the quantum well. The dominant degradation mechanism is initiated when electron hole pairs are created in the quantum well. Absorption of light in deep defect bands, e.g., of the p-type cladding material is negligible in these structures. The strain state of the quantum well is one possible driving force for the degradation. In this context, point defect propagation as well as a structural phase transition of the ZnCdSe quantum well are discussed. (C) 1999 American Institute of Physics. [S0003-6951(99)00736-6]. C1 Univ Wurzburg, Inst Phys, D-97074 Wurzburg, Germany. RP Vogelgesang, R (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Vogelgesang, Ralf/B-4460-2009; Geurts, Jean/N-1828-2015 OI Vogelgesang, Ralf/0000-0002-1026-3205; NR 13 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 1999 VL 75 IS 10 BP 1351 EP 1353 DI 10.1063/1.124690 PG 3 WC Physics, Applied SC Physics GA 230BT UT WOS:000082231800003 ER PT J AU Ishimaru, M Sickafus, KE AF Ishimaru, M Sickafus, KE TI Dose dependence of microstructural evolution in oxygen-ion-implanted silicon carbide SO APPLIED PHYSICS LETTERS LA English DT Article AB Transmission electron microscopy (TEM) and Rutherford backscattering spectroscopy and ion channeling (RBS/C) have been used to characterize the microstructures and damage distributions in oxygen-ion-implanted silicon carbide (SiC). 6H-SiC single crystals with [0001] orientation were irradiated with 180 keV O+ ions at 650 degrees C to fluences ranging from 0.2x10(18) to 1.4x10(18)/cm(2). No continuous buried amorphous layer was formed in the specimen with 0.2x10(18) O+/cm(2), although there were striated regions consisting of amorphous and crystalline structures at depth between 200 and 300 nm. A continuous buried amorphous layer appeared above 0.4x10(18) O+/cm(2), and the amorphous regions grew in size with increasing fluence. TEM and RBS/C results indicated that microstructures and elemental distributions change drastically between 0.7x10(18) and 1.4x10(18) O+/cm(2). (C) 1999 American Institute of Physics. [S0003-6951(99)03236-2]. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Kyushu Univ, Dept Mat Sci & Engn, Fukuoka 8128581, Japan. RP Ishimaru, M (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 14 TC 10 Z9 12 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 1999 VL 75 IS 10 BP 1392 EP 1394 DI 10.1063/1.124704 PG 3 WC Physics, Applied SC Physics GA 230BT UT WOS:000082231800017 ER PT J AU Shan, W Yu, KM Walukiewicz, W Ager, JW Haller, EE Ridgway, MC AF Shan, W Yu, KM Walukiewicz, W Ager, JW Haller, EE Ridgway, MC TI Reduction of band-gap energy in GaNAs and AlGaNAs synthesized by N+ implantation SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; OPTICAL-PROPERTIES; NITROGEN; GAAS; GAINNAS; LAYERS; ALLOY AB We have studied the optical properties of nitrogen implanted GaAs and AlGaAs samples. The fundamental band-gap energy has been found to decrease with the increasing N+ implantation dose in a manner similar to that commonly observed in GaNAs and GaInNAs alloys grown by molecular beam epitaxy or metal organic chemical vapor deposition. Our results indicate that GaNxAs1-x and AlxGa1-xNyAs1-y alloys can be formed by implantation of nitrogen followed by appropriate postimplantation annealing treatments. As inferred from the magnitude of the band gap shift, the percentage of the implanted N atoms incorporated on the substitutional As sites is estimated to be around 12%. (C) 1999 American Institute of Physics. [S0003-6951(99)00336-8]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT 2601, Australia. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM weishan@ux8.lbl.gov RI Yu, Kin Man/J-1399-2012; Ridgway, Mark/D-9626-2011; OI Yu, Kin Man/0000-0003-1350-9642; Ridgway, Mark/0000-0002-0642-0108; Ager, Joel/0000-0001-9334-9751 NR 22 TC 72 Z9 72 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 1999 VL 75 IS 10 BP 1410 EP 1412 DI 10.1063/1.124951 PG 3 WC Physics, Applied SC Physics GA 230BT UT WOS:000082231800023 ER PT J AU Bhattacharya, RN Batchelor, W Hiltner, JF Sites, JR AF Bhattacharya, RN Batchelor, W Hiltner, JF Sites, JR TI Thin-film CuIn1-xGaxSe2 photovoltaic cells from solution-based precursor layers SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLAR-CELLS; DEVICE AB We have fabricated 15.4% and 12.4% efficient thin-film CuIn1-xGaxSe2 (CIGS)-based photovoltaic devices from solution-based electrodeposited (ED) and electroless-deposited (EL) precursors. As-deposited precursors are Cu-rich CIGS. Additional In, Ga, and Se are added to the ED and EL precursor films by physical vapor deposition (PVD) to adjust the final semiconductor film composition to CuIn1-xGaxSe2. The ED and EL device parameters are compared with those of a 17.7% PVD device. The tools used for comparison are current voltage, capacitance voltage, and spectral response characteristics. (C) 1999 American Institute of Physics. [S0003-6951(99)03736-5]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. RP Bhattacharya, RN (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 8 TC 45 Z9 49 U1 2 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 1999 VL 75 IS 10 BP 1431 EP 1433 DI 10.1063/1.124716 PG 3 WC Physics, Applied SC Physics GA 230BT UT WOS:000082231800030 ER PT J AU Thapper, A Donahue, JP Musgrave, KB Willer, MW Nordlander, E Hedman, B Hodgson, KO Holm, RH AF Thapper, A Donahue, JP Musgrave, KB Willer, MW Nordlander, E Hedman, B Hodgson, KO Holm, RH TI The unperturberd oxo-sulfido functional group cis-Mo(VI)OS related to that in the xanthine oxidase family of molybdoenzyme: Synthesis, structural characterization, and reactivity aspects SO INORGANIC CHEMISTRY LA English DT Article ID X-RAY-ABSORPTION; OXYGEN-ATOM TRANSFER; NUCLEOPHILE TRANSFER-REACTIONS; MOLYBDENUM ENZYMES; SULFUR ATOM; THERMOCHEMICAL STABILITY; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; EXAFS ANALYSIS; ACTIVE-SITES AB The oxo-sulfido functional group Cis-(MoOS)-O-VI is essential to the activity of the xanthine oxidase family of enzymes but has proven elusive to synthesis in molecules containing no other four-electron ligands. A direct route to molecules containing this group has been achieved. The reaction system [MoO2(OSiPh3)(2)]/L in dichloromethane yields the complexes [(MoO2)-O-VI(OSiPh3)(2)L] (L = phen (1), Me(4)phen (2), 4,4'-Me(2)bpy (3), 5,5'-Me(2)bpy (4), 2 py (5)) (74-96%), which are shown to have a distorted octahedral structure of crystallographically imposed C-2 symmetry (1, 5) with cis oxo and trans silyloxy ligands. The related reaction system [MoO3S](2-)/2Ph(3)SiCl/L in acetonitrile affords the complexes [(MoOS)-O-VI(OSiPh3)(2)L] (L = phen (6), Me(4)phen (7), 4,4'-Me(2)bpy (8), 5,5'-Me(2)bpy (9)) (36-69%). From the collective results of elemental analysis, mass spectrometry, H-1 NMR, and X-ray structure determinations (6, 7), complexes 6-9 are shown to contain the cis-(MoOS)-O-VI group in molecules with the same overall stereochemistry as dioxo complexes 1-5. The crystal structures of 6 and 7 exhibit O/S disorder, which was modeled in refinements with 50% site occupancies. The Mo=O (1.607(5) (6), 1.645(5) (7) Angstrom) and Mo=S (2.257(3) (6), 2.203(2) (7) Angstrom) bond distances obtained in this way are somewhat shorter and longer, respectively, than expected. Distances obtained 6-9 (Mo=O 1.71-1.72 Angstrom; Mo=S 2.18-2.19 Angstrom) are considered more satisfactory and are in good agreement with EXAFS values for xanthine oxidase. Molybdenum K-edge data for 1 and 6-9 are reported. Reaction of 7 with Ph3P in dichloromethane results in sulfur abstraction and formation of [(MoOCl)-O-V(OSiPh3)(2)(Me(4)phen)] (10), which has a distorted octahedral structure with cis O/Cl and cis silyloxy ligands. Sulfur rather than oxygen abstraction is favored by relative Mo=O/Mo=S bond strengths. Complexes 6-9 should allow exploration of the biologically significant Cis-(MoOS)-O-VI group. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Lund, Ctr Chem, S-22100 Lund, Sweden. Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. RP Hedman, B (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Thapper, Anders/A-6728-2010 NR 59 TC 46 Z9 46 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 6 PY 1999 VL 38 IS 18 BP 4104 EP 4114 DI 10.1021/ic990440v PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 235DP UT WOS:000082525000023 ER PT J AU Revel, R Den Auwer, C Madic, C David, F Fourest, B Hubert, S Le Du, JF Morss, LR AF Revel, R Den Auwer, C Madic, C David, F Fourest, B Hubert, S Le Du, JF Morss, LR TI First investigation on the L edges of the Cf-249 aquo ion by X-ray absorption spectroscopy SO INORGANIC CHEMISTRY LA English DT Article ID OXIDATION-STATE; FINE-STRUCTURE C1 CEA Marcoule, DCC, DRRV, SEMP,Lab Chim Theor & Struct, Bagnols Sur Ceze, France. Univ Paris Sud, LURE, F-91898 Orsay, France. CEA, DCC, DIR, F-91191 Gif Sur Yvette, France. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Revel, R (reprint author), IFP, 1-4 Ave Bois Preau, F-92852 Rueil Malmaison, France. NR 18 TC 36 Z9 36 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 6 PY 1999 VL 38 IS 18 BP 4139 EP + DI 10.1021/ic990214l PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 235DP UT WOS:000082525000029 ER PT J AU Wilkerson, MP Burns, CJ Paine, RT Scott, BL AF Wilkerson, MP Burns, CJ Paine, RT Scott, BL TI Synthesis and crystal structure of UO2Cl2(THF)(3): A simple preparation of an anhydrous uranyl reagent SO INORGANIC CHEMISTRY LA English DT Article ID COMPLEXES C1 Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Burns, CJ (reprint author), Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 23 TC 85 Z9 85 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 6 PY 1999 VL 38 IS 18 BP 4156 EP + DI 10.1021/ic990159g PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 235DP UT WOS:000082525000034 ER PT J AU Brnicevic, N Sirac, S Basic, I Zhang, ZH McCarley, RE Guzei, IA AF Brnicevic, N Sirac, S Basic, I Zhang, ZH McCarley, RE Guzei, IA TI [Ta6Cl12(PrCn)(6)][(Ta6Cl12)Cl-6]center dot 2PrCn, a compound with homonuclear mixed-charge cluster units [Ta6Cl12](2+) and [Ta6Cl12](4+) SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURES; TANTALUM; NIOBIUM; COMPLEXES; TA; BR C1 Rudjer Boskovic Inst, Zagreb 10001, Croatia. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Brnicevic, N (reprint author), Rudjer Boskovic Inst, Bijenicka 54, Zagreb 10001, Croatia. NR 13 TC 11 Z9 11 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 6 PY 1999 VL 38 IS 18 BP 4159 EP + PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 235DP UT WOS:000082525000035 ER PT J AU Abe, K Abe, K Abe, T Adam, I Akagi, T Allen, NJ Arodzero, A Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Bardon, O Barklow, TL Bashindzhagyan, GL Bauer, JM Bellodi, G Ben-David, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Byrne, RM Calcaterra, A Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A Cavalli-Sforza, M Chou, A Church, E Cohn, HO Coller, JA Convery, MR Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G Damerell, CJS Danielson, MN Daoudi, M de Groot, N Dell'Orso, R Dervan, PJ de Sangro, R Dima, M D'Oliveira, A Dong, DN Doser, M Dubois, R Eisenstein, BI Eschenburg, V Etzion, E Fahey, S Falciai, D Fan, C Fernandez, JP Fero, MJ Flood, K Frey, R Gillman, T Gladding, G Gonzalez, S Goodman, ER Hart, EL Harton, JL Hasan, A Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Huynh, X Hwang, H Iwasaki, M Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kamyshkov, Y Kang, HJ Karliner, I Kawahara, H Kim, YD King, R King, ME Kofler, RR Krishna, NM Kroeger, RS Langston, M Lath, A Leith, DWG Lia, V Lin, CJS Liu, X Liu, MX Loreti, M Lu, A Lynch, HL Ma, J Mahjouri, M Mancinelli, G Manley, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Menegatti, G Messner, R Mockett, PM Moffeit, KC Moore, TB Morii, M Muller, D Murzin, V Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Oishi, N Onoprienko, D Osborne, LS Panvini, RS Park, H Park, CH Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Schwiening, J Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Staengle, H Stahl, A Stamer, P Steiner, R Steiner, H Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Thom, J Torrence, E Toumbas, NK Usher, T Vannini, C Va'vra, J Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, SR Wagner, DL Waite, AP Walston, S Wang, J Ward, C Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, B Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Wittlin, JL Woods, M Word, GB Wright, TR Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yashima, J Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J AF Abe, K Abe, K Abe, T Adam, I Akagi, T Allen, NJ Arodzero, A Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Bardon, O Barklow, TL Bashindzhagyan, GL Bauer, JM Bellodi, G Ben-David, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Byrne, RM Calcaterra, A Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A Cavalli-Sforza, M Chou, A Church, E Cohn, HO Coller, JA Convery, MR Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G Damerell, CJS Danielson, MN Daoudi, M de Groot, N Dell'Orso, R Dervan, PJ de Sangro, R Dima, M D'Oliveira, A Dong, DN Doser, M Dubois, R Eisenstein, BI Eschenburg, V Etzion, E Fahey, S Falciai, D Fan, C Fernandez, JP Fero, MJ Flood, K Frey, R Gillman, T Gladding, G Gonzalez, S Goodman, ER Hart, EL Harton, JL Hasan, A Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Huynh, X Hwang, H Iwasaki, M Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kamyshkov, Y Kang, HJ Karliner, I Kawahara, H Kim, YD King, R King, ME Kofler, RR Krishna, NM Kroeger, RS Langston, M Lath, A Leith, DWG Lia, V Lin, CJS Liu, X Liu, MX Loreti, M Lu, A Lynch, HL Ma, J Mahjouri, M Mancinelli, G Manley, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Menegatti, G Messner, R Mockett, PM Moffeit, KC Moore, TB Morii, M Muller, D Murzin, V Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Oishi, N Onoprienko, D Osborne, LS Panvini, RS Park, H Park, CH Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Schwiening, J Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Staengle, H Stahl, A Stamer, P Steiner, R Steiner, H Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Thom, J Torrence, E Toumbas, NK Usher, T Vannini, C Va'vra, J Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, SR Wagner, DL Waite, AP Walston, S Wang, J Ward, C Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, B Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Wittlin, JL Woods, M Word, GB Wright, TR Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yashima, J Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J CA SLD Collaboration TI Direct measurement of A(b) in Z(0) decays using charged kaon tagging SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARITY-VIOLATION; MASS TAG; RESONANCE; PHYSICS; PARAMETERS; ASYMMETRY AB We present a direct measurement of the parity-violating asymmetry A(b) in the Z(0) to coupling using a new technique to distinguish the b and b quarks using charged kaons from B decays. The Z(0) bosons are produced in e(+)e(-) collisions at the SLC with longitudinally polarized electrons. events are selected using a secondary vertex mass tag and Ab is determined from the left-right forward-backward asymmetry. From the 1994-1995 data sample, selected from 100 000 hadronic Z(0) decays, we obtain A(b) = 0.855 +/- 0.088(stat) +/- 0.102(syst). C1 Nagoya Univ, Chikusa Ku, Nagoya, Aichi 464, Japan. Adelphi Univ, Garden City, NY 11530 USA. Aomori Univ, Aomori 030, Japan. Ist Nazl Fis Nucl, Sez Bologna, I-40126 Bologna, Italy. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Boston Univ, Boston, MA 02215 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. Univ Colorado, Boulder, CO 80309 USA. Columbia Univ, New York, NY 10533 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Univ Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Illinois, Urbana, IL 61801 USA. Johns Hopkins Univ, Baltimore, MD 21153 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Mississippi, University, MS 38677 USA. MIT, Cambridge, MA 02139 USA. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Univ Oregon, Eugene, OR 97403 USA. Univ Oxford, Oxford OX1 3RH, England. Ist Nazl Fis Nucl, Sez Padova, I-35100 Padua, Italy. Univ Padua, I-35100 Padua, Italy. Ist Nazl Fis Nucl, Sez Perugia, I-06100 Perugia, Italy. Univ Perugia, I-06100 Perugia, Italy. Ist Nazl Fis Nucl, Sez Pisa, I-56010 Pisa, Italy. Univ Pisa, I-56010 Pisa, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Rutgers State Univ, Piscataway, NJ 08855 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Sogang Univ, Seoul, South Korea. Soongsil Univ, Seoul 156743, South Korea. Univ Tennessee, Knoxville, TN 37996 USA. Tohoku Univ, Sendai, Miyagi 980, Japan. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Washington, Seattle, WA 98105 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Abe, K (reprint author), Nagoya Univ, Chikusa Ku, Nagoya, Aichi 464, Japan. RI de Groot, Nicolo/A-2675-2009; Stahl, Achim/E-8846-2011; de Sangro, Riccardo/J-2901-2012; Cavalli-Sforza, Matteo/H-7102-2015; Kamyshkov, Yuri/J-7999-2016; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016; OI Stahl, Achim/0000-0002-8369-7506; de Sangro, Riccardo/0000-0002-3808-5455; Kamyshkov, Yuri/0000-0002-3789-7152; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636; pieroni, enrico/0000-0002-4246-6963; Toumbas, Nicolaos/0000-0001-8879-7330; Wyss, Jeffery/0000-0002-8277-4012 NR 23 TC 5 Z9 5 U1 0 U2 4 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 SEP 6 PY 1999 VL 83 IS 10 BP 1902 EP 1907 DI 10.1103/PhysRevLett.83.1902 PG 6 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800002 ER PT J AU Abbott, B Abolins, M Abramov, V Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Breedon, R Briskin, G Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chekulaev, SV Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Cooper, WE Coppage, D Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, MK Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Geld, TL Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gobbi, B Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Greenlee, H Griastein, S Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hebert, C Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Ito, AS Jaques, J Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, T Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Ko, W Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kuleshov, S Kulik, Y Kunori, S Landry, F Landsberg, G Lauer, B Leflat, A Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lobkowicz, F Lucotte, A Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mincer, A Mishra, CS Mokhov, N Moromisato, J Mondal, NK Montgomery, HE Mooney, P Mostafa, M da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oshima, N Owen, D Padley, P Para, A Parashar, N Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, E Piegaia, R Piekarz, H Pischalnikov, Y Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shpakov, D Shupe, R Singh, H Singh, JB Sirotenko, V Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sosebee, M Sotnikova, N Souza, M Steinbruck, G Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Vaniev, V Varelas, N Varnes, EW Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Wu, Z Yamada, R Yamin, P Yasuda, T Yepes, P Yip, K Yoshikawa, C Youssef, S Yu, J Yu, Y Zhang, B Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Abramov, V Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Breedon, R Briskin, G Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chekulaev, SV Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Cooper, WE Coppage, D Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, MK Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Geld, TL Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gobbi, B Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Greenlee, H Griastein, S Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hebert, C Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Ito, AS Jaques, J Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, T Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Ko, W Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kuleshov, S Kulik, Y Kunori, S Landry, F Landsberg, G Lauer, B Leflat, A Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lobkowicz, F Lucotte, A Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mincer, A Mishra, CS Mokhov, N Moromisato, J Mondal, NK Montgomery, HE Mooney, P Mostafa, M da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oshima, N Owen, D Padley, P Para, A Parashar, N Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, E Piegaia, R Piekarz, H Pischalnikov, Y Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shpakov, D Shupe, R Singh, H Singh, JB Sirotenko, V Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sosebee, M Sotnikova, N Souza, M Steinbruck, G Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Vaniev, V Varelas, N Varnes, EW Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Wu, Z Yamada, R Yamin, P Yasuda, T Yepes, P Yip, K Yoshikawa, C Youssef, S Yu, J Yu, Y Zhang, B Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A CA D0 Collaboration TI Measurement of the top quark pair production cross section in the all-jets decay channel SO PHYSICAL REVIEW LETTERS LA English DT Article AB We present a measurement of production in collisions at root s = 1.8 TeV from 110 pb(-1) of data collected in the all-jets decay channel with the D0 detector at Fermilab. A neural network analysis yields a cross section of 7.1 +/- 2.8(stat) +/- 1.5(syst) pb at a top quark mass (m(t)) of 172.1 GeV/c(2). Using previous D0 measurements from dilepton and single lepton channels, the combined D0 result for the production cross section is 5.9 +/- 1.2(stat) +/- 1.1(syst) pb for m(t) = 172.1 GeV/c(2). C1 NYU, New York, NY 10003 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Univ Los Andes, Bogota, Colombia. CEA, Serv Phys Particules, DAPNIA, Saclay, France. Panjab Univ, Chandigarh 160014, India. Univ Delhi, Delhi 110007, India. Tata Inst Fundamental Res, Mumbai, India. Kyungsung Univ, Pusan 608736, South Korea. Seoul Natl Univ, Seoul, South Korea. CINVESTAV, Mexico City 14000, DF, Mexico. Inst Nucl Phys, Krakow, Poland. Inst Theoret & Expt Phys, Moscow 117259, Russia. Moscow State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Chicago, IL 60607 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Indiana Univ, Bloomington, IN 47405 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Purdue Univ, W Lafayette, IN 47907 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Kansas, Lawrence, KS 66045 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Nebraska, Lincoln, NE 68588 USA. Columbia Univ, New York, NY 10027 USA. Univ Rochester, Rochester, NY 14627 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Langston Univ, Langston, OK 73050 USA. Univ Oklahoma, Norman, OK 73019 USA. Brown Univ, Providence, RI 02912 USA. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. Rice Univ, Houston, TX 77005 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Won, Eunil/G-9657-2011; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015 OI Sznajder, Andre/0000-0001-6998-1108; Baarmand, Marc/0000-0002-9792-8619; Dudko, Lev/0000-0002-4462-3192; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775 NR 11 TC 35 Z9 35 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 SEP 6 PY 1999 VL 83 IS 10 BP 1908 EP 1913 DI 10.1103/PhysRevLett.83.1908 PG 6 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800003 ER PT J AU Beneke, M Buchalla, G Neubert, M Sachrajda, CT AF Beneke, M Buchalla, G Neubert, M Sachrajda, CT TI QCD factorization for B -> pi pi decays: Strong phases and CP violation in the heavy quark SO PHYSICAL REVIEW LETTERS LA English DT Article ID WEAK AB We show that, in the heavy quark limit, the hadronic matrix elements that enter B meson decays into two light mesons can be computed from first principles, including "nonfactorizable" strong interaction corrections, and expressed in terms of form factors and meson light-cone distribution amplitudes. The conventional factorization result follows in the limit when both power corrections in 1/m(b) and radiative corrections in alpha(s) are neglected. We compute the order-alpha(s) corrections to the decays B-d --> pi(+)pi(-), B-d --> pi(0) pi(0), and B+ --> pi(+) pi(0) in the heavy quark limit and briefly discuss the phenomenological implications for the branching ratios, strong phases and CP violation. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. RP Beneke, M (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. NR 6 TC 896 Z9 905 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 SEP 6 PY 1999 VL 83 IS 10 BP 1914 EP 1917 DI 10.1103/PhysRevLett.83.1914 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800004 ER PT J AU Bai, JZ Ban, Y Bian, JG Blum, I Chen, GP Chen, HF Chen, J Chen, JC Chen, Y Chen, YB Chen, YQ Cheng, BS Cui, XZ Ding, HL Dong, LY Du, ZZ Dunwoodie, W Gao, CS Gao, ML Gao, SQ Gratton, P Gu, JH Gu, SD Gu, WX Gu, YF Guo, YN Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, YZ Izen, JM Jiang, CH Jin, Y Jones, BD Ke, ZJ Kelsey, MK Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, PQ Li, RB Li, W Li, WG Li, XH Li, XN Liu, HM Liu, J Liu, RG Liu, Y Lou, XC Lowery, B Lu, F Lu, JG Luo, XL Ma, EC Ma, JM Malchow, R Mao, HS Mao, ZP Meng, XC Nie, J Olsen, SL Oyang, J Paluselli, D Pan, LJ Panetta, J Porter, F Qi, ND Qi, XR Qian, CD Qiu, JF Qu, YH Que, YK Rong, G Schernau, M Shao, YY Shen, BW Shen, DL Shen, H Shen, XY Sheng, HY Shi, HZ Song, XF Standifird, J Sun, F Sun, HS Sun, Y Sun, YZ Tang, SQ Toki, W Tong, GL Varner, GS Wang, F Wang, LS Wang, LZ Wang, M Wang, P Wang, PL Wang, SM Wang, TJ Wang, YY Weaver, M Wei, CL Wu, YG Xi, DM Xia, XM Xie, PP Xie, Y Xie, YH Xu, GF Xue, ST Yan, J Yan, WG Yang, CM Yang, CY Yang, J Yang, W Yang, XF Ye, MH Ye, SW Ye, YX Yu, CS Yu, CX Yu, GW Yu, YH Yu, ZQ Yuan, CZ Yuan, Y Zhang, BY Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, LS Zhang, QJ Zhang, SQ Zhang, XY Zhang, YY Zhao, DX Zhao, HW Zhao, JW Zhao, JW Zhao, M Zhao, WR Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zhou, BQ Zhou, GP Zhou, HS Zhou, L Zhu, KJ Zhu, QM Zhu, YC Zhu, YS Zhuang, BA AF Bai, JZ Ban, Y Bian, JG Blum, I Chen, GP Chen, HF Chen, J Chen, JC Chen, Y Chen, YB Chen, YQ Cheng, BS Cui, XZ Ding, HL Dong, LY Du, ZZ Dunwoodie, W Gao, CS Gao, ML Gao, SQ Gratton, P Gu, JH Gu, SD Gu, WX Gu, YF Guo, YN Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, YZ Izen, JM Jiang, CH Jin, Y Jones, BD Ke, ZJ Kelsey, MK Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, PQ Li, RB Li, W Li, WG Li, XH Li, XN Liu, HM Liu, J Liu, RG Liu, Y Lou, XC Lowery, B Lu, F Lu, JG Luo, XL Ma, EC Ma, JM Malchow, R Mao, HS Mao, ZP Meng, XC Nie, J Olsen, SL Oyang, J Paluselli, D Pan, LJ Panetta, J Porter, F Qi, ND Qi, XR Qian, CD Qiu, JF Qu, YH Que, YK Rong, G Schernau, M Shao, YY Shen, BW Shen, DL Shen, H Shen, XY Sheng, HY Shi, HZ Song, XF Standifird, J Sun, F Sun, HS Sun, Y Sun, YZ Tang, SQ Toki, W Tong, GL Varner, GS Wang, F Wang, LS Wang, LZ Wang, M Wang, P Wang, PL Wang, SM Wang, TJ Wang, YY Weaver, M Wei, CL Wu, YG Xi, DM Xia, XM Xie, PP Xie, Y Xie, YH Xu, GF Xue, ST Yan, J Yan, WG Yang, CM Yang, CY Yang, J Yang, W Yang, XF Ye, MH Ye, SW Ye, YX Yu, CS Yu, CX Yu, GW Yu, YH Yu, ZQ Yuan, CZ Yuan, Y Zhang, BY Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, LS Zhang, QJ Zhang, SQ Zhang, XY Zhang, YY Zhao, DX Zhao, HW Zhao, JW Zhao, JW Zhao, M Zhao, WR Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zhou, BQ Zhou, GP Zhou, HS Zhou, L Zhu, KJ Zhu, QM Zhu, YC Zhu, YS Zhuang, BA CA BES Collaboration TI Charmonium decays to axial-vector plus pseudoscalar mesons SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTICLE PHYSICS; J/PSI AB A sample of 3.79 X 10(6) psi(2S) events is used to study the decays of charmonium to axial-vector plus pseudoscalar mesons. The branching fraction for the decay psi(2S) --> b(1)(+/-) (1235)pi(-/+) agrees with expectations based on scaling the corresponding J/psi branching fraction. Flavor-SU(3)-violating K-1(1270)-K-1(1400) asymmetries with opposite character for psi(2S) and J/psi decays are observed. This contrasting behavior cannot be accommodated by adjustments of the singlet-triplet mixing angle. C1 Inst High Energy Phys, Beijing 100039, Peoples R China. CALTECH, Pasadena, CA 91125 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Hangzhou Univ, Hangzhou 310028, 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. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Calif Irvine, Irvine, CA 92717 USA. Univ Sci & Technol China, Hefei 230026, Peoples R China. Univ Texas, Richardson, TX 75083 USA. RP Bai, JZ (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China. RI Chen, Yu/E-3788-2012; dong, liaoyuan/A-5093-2015; OI dong, liaoyuan/0000-0002-4773-5050; Li, Xiaonan/0000-0003-2857-0219 NR 14 TC 16 Z9 19 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 SEP 6 PY 1999 VL 83 IS 10 BP 1918 EP 1921 DI 10.1103/PhysRevLett.83.1918 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800005 ER PT J AU Farley, DR Estabrook, KG Glendinning, SG Glenzer, SH Remington, BA Shigemori, K Stone, JM Wallace, RJ Zimmerman, GB Harte, JA AF Farley, DR Estabrook, KG Glendinning, SG Glenzer, SH Remington, BA Shigemori, K Stone, JM Wallace, RJ Zimmerman, GB Harte, JA TI Radiative jet experiments of astrophysical interest using intense lasers SO PHYSICAL REVIEW LETTERS LA English DT Article ID DYNAMICS AB A high Mach number, radiatively cooled jet of astrophysical interest has been produced using intense laser irradiation of a gold cone. The evolution of the jet was imaged in emission and in radiography, and the temperature was measured with Thomson scattering. Comparison with numerical simulations shows that radiative cooling is a dominant mechanism in the collapse of the Au plasma jet on axis, with temperatures plummeting and peak densities increasing, each by an order of magnitude in similar to 1/2 ns. In dimensionless terms, aspects of this jet are similar to radiative astrophysical jets. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Osaka Univ, Inst Laser Engn, Osaka, Japan. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Farley, DR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Shigemori, Keisuke/B-3262-2013 OI Shigemori, Keisuke/0000-0002-3978-8427 NR 18 TC 118 Z9 119 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 SEP 6 PY 1999 VL 83 IS 10 BP 1982 EP 1985 DI 10.1103/PhysRevLett.83.1982 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800021 ER PT J AU Galli, G Catellani, A Gygi, F AF Galli, G Catellani, A Gygi, F TI Wetting silicon carbide with nitrogen: A theoretical study SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIGHT-EMITTING DEVICES; SURFACE RECONSTRUCTION; EPITAXIAL-GROWTH; CUBIC GAN; NITRIDE; LAYERS; SEMICONDUCTORS; NUCLEATION; FILMS AB In order to model the early stages of nitride growth on cubic silicon carbide, we have studied the deposition of atomic nitrogen on the Si-terminated SiC(001) surface, using first-principles molecular dynamics. For many configurations with coverages less than 1/2 monolayer, N is preferably adsorbed at zinc blende sites and forms nitridized Si pairs. At one monolayer, N forms instead hydrazinelike N2Si4 complexes, yielding a fully coated, inert substrate which inhibits growth. In this configuration, full nitridization of the surface is energetically favored. Interface mixing and formation of C-N bonds are observed when mimicking the deposition of positively charged nitrogen ions. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. CNR, MASPEC, I-43100 Parma, Italy. RP Galli, G (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. OI Catellani, Alessandra/0000-0001-5197-7186 NR 27 TC 9 Z9 9 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 SEP 6 PY 1999 VL 83 IS 10 BP 2006 EP 2009 DI 10.1103/PhysRevLett.83.2006 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800027 ER PT J AU Mattila, T Wei, SH Zunger, A AF Mattila, T Wei, SH Zunger, A TI Electronic structure of "sequence mutations" in ordered GaInP2 alloys SO PHYSICAL REVIEW LETTERS LA English DT Article ID SEMICONDUCTOR ALLOYS; QUANTUM DOTS; PHOTOLUMINESCENCE; SUPERLATTICES; GA0.5IN0.5P; DEPENDENCE AB The electronic consequences of layer thickness fluctuations in CuPt-ordered GaInP2 (layer sequence Ga-In-Ga-In...) are investigated. We show that the formation of a "sequence mutated" Ga-In-In-Ga...region creates a hole state h1 localized in the In-in double layer, while the electron state e1 is localized in the CuPt-ordered region. Thus, the system exhibits electron-hole charge separation in addition to spatial localization. This physical picture is preserved when the dimension of the mutated segment is reduced from 2D to 0D, resulting in disklike dot structures. Our theory explains the longstanding puzzle of the origin of the peculiar luminescence properties of ordered GaInP2. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mattila, T (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 22 TC 35 Z9 35 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 SEP 6 PY 1999 VL 83 IS 10 BP 2010 EP 2013 DI 10.1103/PhysRevLett.83.2010 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800028 ER PT J AU Movshovich, R Jaime, M Mentink, S Menovsky, AA Mydosh, JA AF Movshovich, R Jaime, M Mentink, S Menovsky, AA Mydosh, JA TI Second low-temperature phase transition in frustrated UNi4B SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANTIFERROMAGNETS; CSCOBR3; MAGNETS AB Hexagonal UNi4B is magnetically frustrated, yet it orders antiferromagnetically at T-N = 20 K. However, one-third of the U spins remains paramagnetic below this temperature. In order to track these spins to lower temperature, we measured the specific heat C of UNi4B between 100 mK and 2 K, in applied fields up to 9 T. A sharp kink in C at T* approximate to 330 mK is observed at zero field, which we interpret as an indication of a second phase transition involving paramagnetic U. We attribute the rise in gamma = C/T between 7 K and 330 mK and the absence of a large entropy liberated at T* to a combination of Kondo screening effects and frustration that strongly modifies the low T transition. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. RP Movshovich, R (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Jaime, Marcelo/F-3791-2015 OI Jaime, Marcelo/0000-0001-5360-5220 NR 22 TC 13 Z9 13 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 6 PY 1999 VL 83 IS 10 BP 2065 EP 2068 DI 10.1103/PhysRevLett.83.2065 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800042 ER PT J AU Schafer, J Rotenberg, E Meigs, G Kevan, SD Blaha, P Hufner, S AF Schafer, J Rotenberg, E Meigs, G Kevan, SD Blaha, P Hufner, S TI Direct spectroscopic observation of the energy gap formation in the spin density wave phase transition at the Cr(110) surface SO PHYSICAL REVIEW LETTERS LA English DT Article ID GENERALIZED-GRADIENT-APPROXIMATION; ELECTRONIC-STRUCTURE; CHROMIUM; PHOTOEMISSION AB The spin density wave phase transition in chromium has been studied by angle-resolved photoemission on a (110) surface. The electronic band structure is shown to exhibit backfolding in the antiferromagnetic state. Direct spectroscopic evidence is obtained on the gradual opening of an energy gap at the Fermi level. The gap extends almost isotropically around the Gamma point, its magnitude reaching similar to 200 meV at room temperature. Density-functional band structure calculations confirm the location of the energy gap in reciprocal space and yield enhanced magnetic moments towards the surface. The transition probed in the near-surface layers exhibits a critical temperature of similar to 440 K. C1 Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Tech Univ Vienna, Inst Phys & Theoret Chem, A-1060 Vienna, Austria. Univ Saarlandes, Fachbereich Phys, D-66041 Saarbrucken, Germany. RP Schafer, J (reprint author), Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RI Blaha, Peter/F-2847-2010; Rotenberg, Eli/B-3700-2009; Kevan, Stephen/F-6415-2010 OI Rotenberg, Eli/0000-0002-3979-8844; Kevan, Stephen/0000-0002-4621-9142 NR 19 TC 39 Z9 39 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 6 PY 1999 VL 83 IS 10 BP 2069 EP 2072 DI 10.1103/PhysRevLett.83.2069 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800043 ER PT J AU Valla, T Fedorov, AV Johnson, PD Hulbert, SL AF Valla, T Fedorov, AV Johnson, PD Hulbert, SL TI Many-body effects in angle-resolved photoemission: Quasiparticle energy and lifetime of a Mo(110) surface state SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-SURFACE; SPECTROSCOPY AB In a high-resolution photoemission study of a Mo(110) surface state various contributions to the measured width and energy of the quasiparticle peak are investigated. Electron-phonon coupling, electron-electron interactions, and scattering from defects are all identified mechanisms responsible for the finite lifetime of a valence photohole. The electron-phonon induced mass enhancement and rapid change of the photohole lifetime near the Fermi level are observed for the first time. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Valla, T (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 19 TC 225 Z9 226 U1 4 U2 28 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 SEP 6 PY 1999 VL 83 IS 10 BP 2085 EP 2088 DI 10.1103/PhysRevLett.83.2085 PG 4 WC Physics, Multidisciplinary SC Physics GA 232WK UT WOS:000082392800047 ER PT J AU Blaudeau, JP Zygmunt, SA Curtiss, LA Reed, DT Bursten, BE AF Blaudeau, JP Zygmunt, SA Curtiss, LA Reed, DT Bursten, BE TI Relativistic density functional investigation of Pu(H2O)(n)(3+) clusters SO CHEMICAL PHYSICS LETTERS LA English DT Article ID AQUO IONS; WATER; NONADDITIVITY; SPECTROSCOPY; HYDROLYSIS; COMPLEXES; CHEMISTRY; MOLECULES; DYNAMICS AB The solvation of the Pu3+ ion in water was investigated using relativistic density functional theory including generalized gradient corrections. Binding energies and optimized geometries for different coordination numbers of water molecules [Pu(H-2,O)(n)(3+) , n = 6, 8, 9, 10, 12] around the ion were calculated. The results indicate that the Fast solvation shell of PU3+ is likely to contain eight or possibly nine waters with a Pu-O bond length of 2.51-2.55 Angstrom. The theoretical results are compared with two recent EXAFS experiments on the Pu3+ aqueous system. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM jblaudea@chemistry.ohio-state.edu; curtiss@anlchm.chm.anl.gov NR 26 TC 23 Z9 23 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 3 PY 1999 VL 310 IS 3-4 BP 347 EP 354 DI 10.1016/S0009-2614(99)00784-8 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 233XN UT WOS:000082452600016 ER PT J AU Gerasimov, MR Dewey, SL AF Gerasimov, MR Dewey, SL TI Gamma-vinyl gamma-aminobutyric acid attenuates the synergistic elevations of nucleus accumbens dopamine produced by a cocaine/heroin (speedball) challenge SO EUROPEAN JOURNAL OF PHARMACOLOGY LA English DT Article DE speedball; cocaine; heroin; dopamine; microdialysis; addiction AB In the present study, we examined the effect of an acute administration of the selective suicide inhibitor of gamma-aminobutyric acid (GABA)-transaminase, gamma-vinyl GABA on increases in nucleus accumbens dopamine produced by a cocaine/heroin challenge in freely moving animals. Cocaine (20 mg/kg, i.p.) produced an elevation in extracellular nucleus accumbens dopamine of approximately 380% above baseline, while heroin produced only a moderate increase of 70%. Coadministration of these two drugs, however, produced a synergistic elevation in nucleus accumbens dopamine of 1000%. This response was reduced by 50% in animals pretreated with gamma-vinyl GABA (300 mg/kg, i.p.) 2.5 h prior to challenge. This same dose of gamma-vinyl GABA inhibited cocaine-induced increases in nucleus accumbens dopamine by 25% and completely abolished heroin-induced increase. These findings indicate that gamma-vinyl GABA can interfere with the synergistic effects produced by the combination of an indirect dopamine releaser (heroin) and a dopamine reuptake blocker (cocaine). (C) 1999 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Dewey, SL (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. FU NIADDK NIH HHS [Y1-DOPAMINE7047-01]; NIMH NIH HHS [MH49165]; PHS HHS [R2955155] NR 7 TC 26 Z9 27 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-2999 J9 EUR J PHARMACOL JI Eur. J. Pharmacol. PD SEP 3 PY 1999 VL 380 IS 1 BP 1 EP 4 DI 10.1016/S0014-2999(99)00526-9 PG 4 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 241NV UT WOS:000082890200001 PM 10513553 ER PT J AU De Fazio, F Neubert, M AF De Fazio, F Neubert, M TI B -> X(u)l(nu)over-bar(l) decay distributions to order alpha(s) SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE heavy quark physics; NLO computations; weak decays ID SEMILEPTONIC B-DECAYS; 2-LOOP QCD CORRECTIONS; HEAVY-QUARK DECAY; V-UB; NONPERTURBATIVE CORRECTIONS; B->C TRANSITIONS; LEPTON SPECTRUM; HADRON SPECTRA; MASS-SPECTRUM; MESON DECAYS AB An analytic result for the O(alpha(s)) corrections to the triple differential B --> X-u l <(nu)over bar>(l) decay rate is presented, to leading order in the heavy-quark expansion. This is relevant for computing partially integrated decay distributions with arbitrary cuts on kinematic variables. Several double and single differential distributions are derived, most of which generalize known results. In particular, an analytic result for the O(alpha(s)) corrections to the hadronic invariant mass spectrum is presented. The effects of Fermi motion, which are important for the description of decay spectra close to infrared sensitive regions, are included. The behaviour of perturbation theory in the region of time-like momenta is also investigated. C1 Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP De Fazio, F (reprint author), Ist Nazl Fis Nucl, Sez Bari, Via Amendola N173, I-70126 Bari, Italy. EM Fulvia.Defazio@ba.infn.it; neubert@slac.stanford.edu OI De Fazio, Fulvia/0000-0003-0695-2566 NR 38 TC 99 Z9 99 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP 3 PY 1999 IS 6 AR 017 PG 24 WC Physics, Particles & Fields SC Physics GA 237JF UT WOS:000082651800017 ER PT J AU Dorey, N Hollowood, TJ Khoze, VV Mattis, MP Vandoren, S AF Dorey, N Hollowood, TJ Khoze, VV Mattis, MP Vandoren, S TI Multi-instantons and Maldacena's conjecture SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE solitons monopoles and instantons; 1/N expansion; duality in gauge field theories; supersymmetry and duality ID MULTIINSTANTON MEASURE; SUPERSYMMETRY; BRANES; TERMS; N=4 AB We examine certain n-point functions G(n) in N = 4 supersymmetric SU(N) gauge theory at the conformal point. In the large-N limit, we are able to sum all leading-order multi-instanton contributions exactly. We find compelling evidence for Maldacena's conjecture: (1) The large-N k-instanton collective coordinate space has the geometry of AdS(5) x S-5. (2) In exact agreement with type IIB superstring calculations, at the k-instanton level, G(n) = root N g(8) k(n-7)/(2)e(-8 pi 2k/g2) Sigma(d/k) d(-2) . F-n(x(1),..., x(n)), where F-n is identical to a convolution of n bulk-to-boundary SUGRA propagators. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Los Alamos Natl Lab, Theoret Div T8, Los Alamos, NM 87545 USA. Univ Coll Swansea, Dept Phys, Swansea SA2 8PP, W Glam, Wales. Univ Durham, Dept Phys, Durham DH1 3LE, England. RP Dorey, N (reprint author), Univ Washington, Dept Phys, Seattle, WA 98195 USA. EM dorey@phys.washington.edu; pyth@schwinger.lanl.gov; valya.khoze@durham.ac.uk; mattis@lanl.gov; pysv@swan.ac.uk NR 27 TC 35 Z9 35 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP 3 PY 1999 IS 6 AR 023 PG 13 WC Physics, Particles & Fields SC Physics GA 237JF UT WOS:000082651800023 ER PT J AU El-Kabbani, O Old, SE Ginell, SL Carper, DA AF El-Kabbani, O Old, SE Ginell, SL Carper, DA TI Aldose and aldehyde reductases: Structure-function studies on the coenzyme and inhibitor-binding sites SO MOLECULAR VISION LA English DT Article ID DIABETIC COMPLICATIONS; DIRECTED MUTAGENESIS; X-RAY; HOLOENZYME; MECHANISM; SPECIFICITY; SUBSTRATE; POCKET AB PURPOSE: To identify the structural features responsible for the differences in coenzyme and inhibitor specificities of aldose and aldehyde reductases. METHODS: The crystal structure of porcine aldehyde reductase in complex with NADPH and the aldose reductase inhibitor sorbinil was determined. The contribution of each amino acid lining the coenzyme-binding site to the binding of NADPH was calculated using the Discover package. In human aldose reductase, the role of the non-conserved Pro 216 (Ser in aldehyde reductase) in the binding of coenzyme was examined by site-directed mutagenesis. RESULTS: Sorbinil binds to the active site of aldehyde reductase and is hydrogen-bonded to Trp 22, Tyr 50, His 113, and the non-conserved Arg 312. Unlike tolrestat, the binding of sorbinil does not induce a change in the side chain conformation of Arg 312. Mutation of Pro 216 to Ser in aldose reductase makes the binding of coenzyme more similar to that of aldehyde reductase. CONCLUSIONS: The participation of non-conserved active site residues in the binding of inhibitors and the differences in the structural changes required for the binding to occur are responsible for the differences in the potency of inhibition of aldose and aldehyde reductases. We report that the non-conserved Pro 216 in aldose reductase contributes to the tight binding of NADPH. C1 Monash Univ, Victorian Coll Pharm, Dept Med Chem, Parkville, Vic 3052, Australia. NEI, NIH, Bethesda, MD USA. Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. RP El-Kabbani, O (reprint author), Monash Univ, Victorian Coll Pharm, Dept Med Chem, Parkville Campus,381 Royal Parade, Parkville, Vic 3052, Australia. NR 25 TC 4 Z9 4 U1 0 U2 1 PU MOLECULAR VISION PI ATLANTA PA C/O JEFF BOATRIGHT, LAB B, 5500 EMORY EYE CENTER, 1327 CLIFTON RD, N E, ATLANTA, GA 30322 USA SN 1090-0535 J9 MOL VIS JI Mol. Vis. PD SEP 3 PY 1999 VL 5 IS 20 BP U1 EP U6 PG 6 WC Biochemistry & Molecular Biology; Ophthalmology SC Biochemistry & Molecular Biology; Ophthalmology GA 240KG UT WOS:000082824700001 ER PT J AU Shearer, PM Flanagan, MP AF Shearer, PM Flanagan, MP TI Seismic velocity and density jumps across the 410- and 660-kilometer discontinuities SO SCIENCE LA English DT Article ID ENDOTHERMIC PHASE-CHANGE; UPPER-MANTLE; LAYERED CONVECTION; EARTHS MANTLE; SPINEL; MODEL; FORM; FORSTERITE; TRANSITION; OLIVINE AB The average seismic velocity and density jumps across the 410- and 660-kilometer discontinuities in the upper mantle were determined by modeling the observed range dependence in Long-period seismic wave arrivals that reflect off of these interfaces. The preliminary reference Earth model (PREM) is within the computed 95 percent confidence ellipse for the 410-km discontinuity but outside the allowed jumps across the 660-kilometer discontinuity. Current pyrolite mantle models appear consistent with the constraints for the 410-kilometer discontinuity but overpredict amplitudes for the 660-kilometer reflections. The density jump across the 660-kilometer discontinuity is between 4 and 6 percent, below the PREM value of 9.3 percent commonly used in mantle convection calculations. C1 Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Shearer, PM (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. RI Shearer, Peter/K-5247-2012 OI Shearer, Peter/0000-0002-2992-7630 NR 34 TC 78 Z9 88 U1 1 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 3 PY 1999 VL 285 IS 5433 BP 1545 EP 1548 DI 10.1126/science.285.5433.1545 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 232FD UT WOS:000082359500059 ER PT J AU Moriarty, NW Brown, NJ Frenklach, M AF Moriarty, NW Brown, NJ Frenklach, M TI Hydrogen migration in the phenylethen-2-yl radical SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SEMIEMPIRICAL METHODS; PERTURBATION-THEORY; INTERNAL-ROTATION; GAUSSIAN-2 THEORY; MOLLER-PLESSET; BASIS-SET; OPTIMIZATION; FREQUENCIES; PARAMETERS; ENERGIES AB The migration of hydrogen in the phenylethen-2-yl radical is investigated by determining optimal geometries and barrier and reaction energies using several quantum mechanical methods. Rate coefficients and equilibrium constants are obtained using the calculated data and RRKM theory. Theoretical methods compared include PM3, MP2, B3-LYP, CASPT2, and G2MP2. The applicability of these methods and comparisons with two others, G2M and CBS-RAD proposed to improve treatment of radicals, are discussed. The results obtained at the most reliable level of theory produce reaction rates sufficiently fast for these reactions to play a role in high-temperature aromatic chemistry. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Energy & Environm Technol Div, Berkeley, CA 94720 USA. RP Frenklach, M (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. NR 43 TC 33 Z9 33 U1 2 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 SEP 2 PY 1999 VL 103 IS 35 BP 7127 EP 7135 DI 10.1021/jp991481f PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 239UL UT WOS:000082788000028 ER PT J AU Brock, SL Sanabria, M Suib, SL Urban, V Thiyagarajan, P Potter, DI AF Brock, SL Sanabria, M Suib, SL Urban, V Thiyagarajan, P Potter, DI TI Particle size control and self-assembly processes in novel colloids of nanocrystalline manganese oxide SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Review ID SOL-GEL SYNTHESIS; RAY-ABSORPTION-SPECTROSCOPY; VANADIUM PENTOXIDE GELS; HYDROTHERMAL SYNTHESIS; THIN-FILMS; THERMAL-DECOMPOSITION; ELECTRON-DIFFRACTION; TEMPLATE SYNTHESIS; CRYSTAL-STRUCTURE; MOLECULAR-SIEVE AB The synthesis of semiconducting nanocrystals of manganese oxide of controlled sizes and their manipulation to form ordered arrays is described. Nanocrystalline mixed-valent manganese oxides have been prepared as colloidal solutions via reduction of tetraalkylammonium (methyl, ethyl, propyl, and butyl) permanganate salts in aqueous solutions with 2-butanol and ethanol. Reduction with the poorly water miscible 2-butanol produces aqueous colloids for the methyl, ethyl, and propyl systems, whereas 2-butanol colloids are produced for the butyl system. The colloids are reddish-brown, have an average manganese oxidation state of 3.70-3.79, and have been prepared in manganese concentrations up to 0.57 M. The sols will gel upon aging, and the gel time depends on the cation, the amount of alcohol. the temperature, and the concentration of manganese. Small angle neutron scattering (SANS) data indicate that the particles are disklike in shape with radii in the range 20-80 Angstrom and are largely unassociated in solution. Thin films produced from evaporation of the colloid or spreading of the gel onto glass slides demonstrate long-range order, yielding an X-ray diffraction (XRD) pattern consistent with a structure of CdI(2)-type layers of manganese oxide with tetraalkylammonium cations and water molecules interspersed between the layers. The SANS and XRD evidence are consistent with a mechanism of self-assembly of unassociated layers upon concentration and evaporation. Consistent with a mechanism of quantum confinement, UV/visible spectroscopy of the colloids reveals two absorbances, one near 220 nm and the other in the range 290-310 nm, blue-shifted from the maxima observed for bulk manganese oxide (400 nm). When the samples are aged, these bands shift to the red. The growth of particles in solution with a,aging, indicated by the shifts in absorbance, has been confirmed by SANS experiments. C1 Univ Connecticut, Dept Chem, Storrs, CT 06269 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Univ Connecticut, Dept Met & Mat Engn, Storrs, CT 06269 USA. RP Suib, SL (reprint author), Univ Connecticut, Dept Chem, U-60,55 N Eagleville Rd, Storrs, CT 06269 USA. RI Urban, Volker/N-5361-2015; OI Urban, Volker/0000-0002-7962-3408; Brock, Stephanie/0000-0002-0439-302X NR 109 TC 115 Z9 115 U1 4 U2 69 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 SEP 2 PY 1999 VL 103 IS 35 BP 7416 EP 7428 DI 10.1021/jp991009u PG 13 WC Chemistry, Physical SC Chemistry GA 239UH UT WOS:000082787700006 ER PT J AU Rodriguez, JA Hrbek, J AF Rodriguez, JA Hrbek, J TI Interaction of sulfur with well-defined metal and oxide surfaces: Unraveling the mysteries behind catalyst poisoning and desulfurization SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID REPULSIVE INTERACTIONS; ADSORPTION; S-2; CO; HYDRODESULFURIZATION; CHEMISORPTION; REACTIVITY; MECHANISM; PT(111); SO2 C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Texas A&M Univ, College Stn, TX 77843 USA. RI Hrbek, Jan/I-1020-2013 NR 53 TC 181 Z9 182 U1 4 U2 53 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD SEP PY 1999 VL 32 IS 9 BP 719 EP 728 DI 10.1021/ar9801191 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 240LH UT WOS:000082827100001 ER PT J AU Hasegawa, Y Ueji, Y Okitsu, K Ablett, JM Siddons, DP Amemiya, Y AF Hasegawa, Y Ueji, Y Okitsu, K Ablett, JM Siddons, DP Amemiya, Y TI Tunable X-ray polarization reflector with perfect crystals SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID PHASE RETARDERS; DIFFRACTION; SCATTERING; ABSORPTION; COBALT; ION AB The possibility of a transmission-type X-ray linear polarizer is investigated using a thin Bragg reflector as a polarizing filter. In this device, the transmitted beam (rather than the Bragg-reflected beam) is the useful output of the device. Consequently, the position and the direction of the transmitted beam are unchanged as the energy is changed, or even when the polarization direction to be filtered out is changed. Theoretical considerations as well as preliminary transmissivity measurements are presented. The use of perfect crystals of silicon and diamond is examined. A polarization ratio, defined as I-H/I-V, higher than 10(5) was observed in experiments to measure the performance characteristics of the proposed X-ray polarizing reflector. The transmission-type X-ray linear polarizer is well suited for spectroscopic measurements with polarized X-rays. C1 Univ Tokyo, Engn Res Inst, Tokyo 113, Japan. Grad Univ Adv Studies, Tsukuba, Ibaraki 305, Japan. Natl Res Lab Metrol, Tsukuba, Ibaraki 305, Japan. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Hasegawa, Y (reprint author), Univ Tokyo, Dept Appl Phys, 7-3-1 Hongo, Tokyo 1138656, Japan. NR 21 TC 2 Z9 2 U1 1 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD SEP 1 PY 1999 VL 55 BP 955 EP 962 DI 10.1107/S0108767399007138 PN 5 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 238TG UT WOS:000082727000019 ER PT J AU Deevi, S Liu, CT Yamaguchi, M AF Deevi, S Liu, CT Yamaguchi, M TI Intermetallics define the future SO ADVANCED MATERIALS & PROCESSES LA English DT Editorial Material C1 Philip Morris Inc, Richmond, VA 23261 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Kyoto Univ, Kyoto, Japan. RP Deevi, S (reprint author), Philip Morris Inc, Richmond, VA 23261 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD SEP PY 1999 VL 156 IS 3 BP 6 EP 6 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA 233JZ UT WOS:000082424900002 ER PT J AU Brooke, JN Stairmand, JW AF Brooke, JN Stairmand, JW TI Agitation combined with solid-liquid separation: Reengineering nuclear waste processing operations SO ADVANCES IN ENVIRONMENTAL RESEARCH LA English DT Article DE agitation; solid-liquid separation; settling; mixing; blending; fluidic pump; nuclear waste; computational fluid dynamics; flowsheet simplification; process reengineering AB The U.S. Department of Energy (DOE) is processing the high level waste that resulted from nuclear weapons production into stable forms for permanent storage. The variation in waste composition between tanks mandates either blending or segregation in preparation for the succeeding treatment processes. Insoluble solids must be removed prior to the salt solution treatment process. Bench-scale demonstration and computational fluid dynamic analysis suggest that a 1.2 million gallon (4,500 m(3)) waste storage tank can be modified to accomplish the combined functions of solid-liquid separation, mixing to stabilize solid and liquid compositions and blending-in solids added to create the target glass composition. Only four tank modifications would be required: 1. Eleven Power Fluidic PulseJet(TM) mixers each combined with a Power Fluidic Reverse Flow Diverter(TM) pump 2. Two Power Fluidic Diode(TM) transfer pumps each combined with a Power Fluidic(TM) sampler 3. One flocculant addition system 4. One tank inlet downcomer to below the sludge-liquid interface. This note describes the proposed equipment and its operation. Preliminary equipment sizing calculations are given together with a CFD analysis of flow profiles in the vessel to assess the viability of the proposed system. The analysis suggests that this system could achieve the required mixing and phase separations simultaneously using Power Fluidic(TM) technology. C1 Westinghouse Savannah River Co, Aiken, SC 29808 USA. AEA Technol, Power Fluid Grp, Risley WA3 6AT, Cheshire, England. RP Brooke, JN (reprint author), Westinghouse Savannah River Co, Bldg 773 A,Savannah River Site, Aiken, SC 29808 USA. NR 1 TC 0 Z9 0 U1 1 U2 3 PU NELSON & COMMONS COMMUNICATIONS PI BERKELEY PA 1620 ACTON STREET, BERKELEY, CA 94702 USA SN 1093-0191 J9 ADV ENVIRON RES JI Adv. Environ. Res. PD FAL PY 1999 VL 3 IS 3 BP 269 EP 276 PG 8 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA 253MZ UT WOS:000083561500004 ER PT J AU Shor, JT Frazier, GC AF Shor, JT Frazier, GC TI Descriptive theoretical treatment of the gas-solid reaction and mass transfer of hydrogen chloride and lead oxide SO ADVANCES IN ENVIRONMENTAL RESEARCH LA English DT Article DE incineration; hazardous waste; kinetics; mass transfer; lead oxide; hydrogen chloride AB Theoretical models are developed to describe and explain experimental observations of the kinetics of mass transfer and reaction between solid PbO porous pellets and HCl gas at 2000-4000 ppm molar concentration in air, principally between 500-700 degrees C. The experiments were designed to simulate a hazardous waste incinerator operation, and the experimental results were reported in a previous work (Shor and Frazier, 1997). The primary models assume a series of two chemical reactions proceeding at different rates as the temperature is changed. Coupled partial differential equations with mass transfer and reaction terms were solved with best-available data for diffusion coefficients and reaction rate constants. Original data were available on solid and gaseous concentrations of reactants and products. The equations were solved using finite-difference calculations with moving boundary value conditions. The data were compared with results predicted by the model. The Henry's Law constant and diffusion coefficients of HCl were important in a sensitivity analysis as was the reaction rate constant of the initial reaction in the series. Less significant were the diffusion rate of the PbCl2 final product, the solid state concentration of HCl, and the secondary reaction rate constant. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37916 USA. RP Shor, JT (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. NR 12 TC 0 Z9 0 U1 0 U2 1 PU NELSON & COMMONS COMMUNICATIONS PI BERKELEY PA 1620 ACTON STREET, BERKELEY, CA 94702 USA SN 1093-0191 J9 ADV ENVIRON RES JI Adv. Environ. Res. PD FAL PY 1999 VL 3 IS 3 BP 277 EP 292 PG 16 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA 253MZ UT WOS:000083561500005 ER PT J AU Keane, B Pelikan, S Toth, GP Smith, MK Rogstad, SH AF Keane, B Pelikan, S Toth, GP Smith, MK Rogstad, SH TI Genetic diversity of Typha latifolia (Typhaceae) and the impact of pollutants examined with tandem-repetitive DNA probes SO AMERICAN JOURNAL OF BOTANY LA English DT Article DE asexual reproduction; cattails; clonal growth; DNA fingerprinting; population genetics; Typhaceae; variable-number-randem-repeat (VNTR) analysis ID VARIABLE NUMBER; CLONAL GROWTH; UNITED-STATES; POPULATION; FINGERPRINTS; PATTERNS; RUBUS; HETEROZYGOSITY; ROSACEAE; ALLELES AB Genetic diversity at variable-number-tandem-repeat (VNTR) loci was examined in the common cattail, Typha latifolia (Typhaceae), using three synthetic DNA probes composed of tandemly repeated "core" sequences (GACA, GATA, and GCAC). The principal objectives of this investigation were to determine whether: (1) the previously reported almost complete lack of polymorphism at allozyme loci in this species was indicative of a reduced amount of genetic diversity at VNTR loci as well; (2) VNTR markers were informative about possible clonal propagation; and (3) significant differences in genetic structure of sampling sites were associated with differences in environmental levels of pollutants at these sites. Previously, widespread sampling across the eastern United States, surveying across ten allozyme loci, has detected only two genotypes, involving a difference at a single locus, among 104 populations. In this study, the amount of genetic diversity detected at VNTR loci: (1) among ramets (N = 40; 40 genotypes detected) collected at similar to 8-km intervals along a 320-km transect; (2) among ramets (N = 220; 117 genotypes detected) from five study sites separated by 50-3000 m; and (3) even among ramets within each study site [N = 44 per site; from 13 to 34 genotypes detected per site (270 m(2))] exceeds that previously found in those more geographically widespread allozyme surveys. Among the 260 ramets analyzed here, the mean number of bands scored per individual was 48.61 (SD = 2.80). Mean genetic similarity among ramets collected along the 320-km transect was 0.91, which was within the range of mean genetic similarity within the five study sites (range: 0.89-0.95). Among the five study sites, 61% of the samples analyzed appeared to be clonal ramets, with up to 12 clones detected for 44 ramets sampled within a site. Clones grew intermingled and ranged up to 39 m in extent. Permutation tests of genetic similarity revealed significant genetic differentiation between each of the five study sites. Consistent with the previous allozyme studies, T. latifolia was characterized by extremely low genetic variation relative to levels of polymorphism detected at VNTR loci in other plant species. Estimated heterozygosity among ramets along the 320-km transect lan,oed from 0.11 to 0.13, while that within the five study sites ranged from 0.05 to 0.12. Estimates of F(st) (0.32-0.41) also indicated considerable genetic subdivision among these stands. Significantly higher genetic diversity was detected at the two study sites that chemistry and toxicity data indicate to be the most severely impacted by pollutants. Although this correlation does not establish cause and effect, the results of this study indicate that the analysis of genetic diversity at VNTR loci may be a useful tool for monitoring anthropogenic-induced changes in the genetic structure of natural populations of plants. C1 Univ Cincinnati, Dept Biol Sci ML6, Cincinnati, OH 45221 USA. Oak Ridge Inst Sci & Educ, Sci Engn Educ Div, Oak Ridge, TN 37831 USA. US EPA, Ecol Exposure Res Div, Natl Exposure Res Lab, Cincinnati, OH 45268 USA. RP Rogstad, SH (reprint author), Univ Cincinnati, Dept Biol Sci ML6, Cincinnati, OH 45221 USA. EM steven.rogstad@uc.edu NR 61 TC 25 Z9 29 U1 0 U2 3 PU BOTANICAL SOC AMER INC PI ST LOUIS PA PO BOX 299, ST LOUIS, MO 63166-0299 USA SN 0002-9122 J9 AM J BOT JI Am. J. Bot. PD SEP PY 1999 VL 86 IS 9 BP 1226 EP 1238 DI 10.2307/2656770 PG 13 WC Plant Sciences SC Plant Sciences GA 239PU UT WOS:000082779300003 PM 10487810 ER PT J AU Dreon, DM Fernstrom, HA Williams, PT Krauss, RM AF Dreon, DM Fernstrom, HA Williams, PT Krauss, RM TI Very-low-fat diets do not necessarily promote small, dense LDL particles - Reply to JJ Kenney et al SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Letter ID HEART-DISEASE; MEN C1 Univ Calif Berkeley, Dept Mol Med, Lawrence Berkeley Lab, Donner Lab, Berkeley, CA 94720 USA. RP Dreon, DM (reprint author), Univ Calif Berkeley, Dept Mol Med, Lawrence Berkeley Lab, Donner Lab, Room 459, Berkeley, CA 94720 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CLINICAL NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, SUBSCRIPTIONS, RM L-3300, BETHESDA, MD 20814-3998 USA SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD SEP PY 1999 VL 70 IS 3 BP 424 EP 425 PG 2 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 231WM UT WOS:000082334500021 ER PT J AU Mendell, MJ Fisk, WJ Dong, MX Petersen, M Hines, CJ Faulkner, D Deddens, JA Ruder, AM Sullivan, D Boeniger, MF AF Mendell, MJ Fisk, WJ Dong, MX Petersen, M Hines, CJ Faulkner, D Deddens, JA Ruder, AM Sullivan, D Boeniger, MF TI Enhanced particle filtration in a non-problem office environment: Preliminary results from a double-blind crossover intervention study SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article; Proceedings Paper CT 7th Joint Science Symposium on Occupational Safety and Health CY OCT 26-29, 1998 CL HIDDEN VALLEY, PENNSYLVANIA SP Natl Inst Occupat Safety & Hlth, USA, Inst Occupat Hlth, Finland, Natl Inst Working Life, Sweden DE indoor air quality; sick building syndrome; intervention; filtration; ventilation; occupational health and safety; work environment C1 NIOSH, Div Surveillance Hazard Evaluat & Field Studies, Cincinnati, OH 45226 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Mendell, MJ (reprint author), NIOSH, Div Surveillance Hazard Evaluat & Field Studies, 4676 Columbia Pkwy,R-16, Cincinnati, OH 45226 USA. RI Ruder, Avima/I-4155-2012 OI Ruder, Avima/0000-0003-0419-6664 NR 3 TC 2 Z9 2 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD SEP PY 1999 SU 1 BP 55 EP 57 PG 3 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 244TE UT WOS:000083066200020 ER PT J AU Johanson, G Jonsson, F Bois, F AF Johanson, G Jonsson, F Bois, F TI Development of new technique for risk assessment using physiologically based toxicokinetic models SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article; Proceedings Paper CT 7th Joint Science Symposium on Occupational Safety and Health CY OCT 26-29, 1998 CL HIDDEN VALLEY, PENNSYLVANIA SP Natl Inst Occupat Safety & Hlth, USA, Inst Occupat Hlth, Finland, Natl Inst Working Life, Sweden DE methyl chloride; organic solvents; physiologically based toxicokinetic models; population models; risk assessment; occupational health and safety; work environment ID POPULATION C1 Natl Inst Working Life, Dept Toxicol & Risk Assessment, S-17184 Solna, Sweden. Univ Hosp, Dept Med Sci, Uppsala, Sweden. Lawrence Berkeley Lab, Berkeley, CA USA. RP Johanson, G (reprint author), Natl Inst Working Life, Dept Toxicol & Risk Assessment, S-17184 Solna, Sweden. RI Bois, Frederic/E-9241-2012 OI Bois, Frederic/0000-0002-4154-0391 NR 5 TC 6 Z9 6 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD SEP PY 1999 SU 1 BP 101 EP 103 PG 3 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 244TE UT WOS:000083066200036 ER PT J AU Bissell, MJ AF Bissell, MJ TI Tumor plasticity allows vasculogenic mimicry, a novel form of angiogenic switch - A rose by any other name? SO AMERICAN JOURNAL OF PATHOLOGY LA English DT Editorial Material ID KERATIN INTERMEDIATE FILAMENTS; UVEAL MALIGNANT-MELANOMA; CILIARY BODY MELANOMAS; 10 LARGEST NUCLEOLI; MICROCIRCULATION ARCHITECTURE; EXTRACELLULAR-MATRIX; CHOROIDAL MELANOMAS; EXPERIMENTAL COEXPRESSION; RECIPROCAL INTERACTIONS; VASCULAR PATTERNS C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Bissell, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NCI NIH HHS [R01 CA057621, CA57621, R37 CA064786, R01 CA064786, CA64786] NR 50 TC 67 Z9 86 U1 2 U2 5 PU AMER SOC INVESTIGATIVE PATHOLOGY, INC PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202-3993 USA SN 0002-9440 J9 AM J PATHOL JI Am. J. Pathol. PD SEP PY 1999 VL 155 IS 3 BP 675 EP 679 DI 10.1016/S0002-9440(10)65164-4 PG 5 WC Pathology SC Pathology GA 235JD UT WOS:000082537800002 PM 10487823 ER PT J AU Kobuchi, H Roy, S Sen, CK Nguyen, HG Packer, L AF Kobuchi, H Roy, S Sen, CK Nguyen, HG Packer, L TI Quercetin inhibits inducible ICAM-1 expression in human endothelial cells through the JNK pathway SO AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY LA English DT Article DE flavonoids; intercellular adhesion molecule-1; activator protein-1; kinases; inflammation; c-Jun amino-terminal kinase ID INTERCELLULAR-ADHESION MOLECULE-1; TUMOR-NECROSIS-FACTOR; ACTIVATED PROTEIN-KINASE; C-JUN KINASE; NF-KAPPA-B; PHORBOL-ESTER; FACTOR-ALPHA; GENE-TRANSCRIPTION; SIGNAL-TRANSDUCTION; DOWN-REGULATION AB Quercetin inhibits inducible ICAM-1 expression in human endothelial cells through the JNK pathway. Am. J. Physiol. 277 (Cell Physiol. 46): C403-C411, 1999.-The cell adhesion molecule intercellular adhesion molecule-1 (ICAM-1) plays a pivotal role in inflammatory responses. Quercetin (3,3',4',5,7-pentahydroxyflavone), a naturally occurring dietary flavonol, has potent anti-inflammatory properties. The effect of quercetin on ICAM-1 expression induced by agonists phorbol 12-myristate 13-acetate (PMA) and tumor necrosis factor-alpha (TNF-alpha) in human endothelial cell line ECV304 (ECV) was investigated. Quercetin treatment downregulated both PMA- and TNF-alpha-induced surface expression, as well as the ICAM-1 mRNA levels, in ECV cells in a dose-dependent (10-50 l-IM) manner. Quercetin had no effect on PMA- or TNF-alpha-induced nuclear factor-KB (NF-KB) activation. However, under similar conditions a remarkable dose-dependent downregulation of activator protein-1 (AP-1) activation was observed. This decrease in AP-1 activation was observed to be associated with the inhibitory effects of quercetin on the c-Jun NH2-terminal kinase (JNK) pathway. These results suggest that quercetin downregulates both PMA- and TNF-alpha-induced ICAM-1 expression via inhibiting both AP-1 activation and the JNK pathway. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energies Technol Div, Berkeley, CA 94720 USA. Univ Kuopio, Dept Physiol, FIN-70211 Kuopio, Finland. RP Roy, S (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 251 Life Sci Addit, Berkeley, CA 94720 USA. EM sashwati@socrates.berkeley.edu RI Sen, Chandan/A-8762-2013; Roy, sashwati/E-3990-2011 FU NIGMS NIH HHS [GM-27345] NR 59 TC 110 Z9 118 U1 0 U2 2 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0363-6143 J9 AM J PHYSIOL-CELL PH JI Am. J. Physiol.-Cell Physiol. PD SEP PY 1999 VL 277 IS 3 BP C403 EP C411 PG 9 WC Cell Biology; Physiology SC Cell Biology; Physiology GA 232UR UT WOS:000082388800007 PM 10484327 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Logan, J Gatley, SJ Gifford, A Hitzemann, R Ding, YS Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Logan, J Gatley, SJ Gifford, A Hitzemann, R Ding, YS Pappas, N TI Prediction of reinforcing responses to psychostimulants in humans by brain dopamine D-2 receptor levels SO AMERICAN JOURNAL OF PSYCHIATRY LA English DT Article ID COCAINE; METHYLPHENIDATE; HALOPERIDOL; ANTAGONISM; BLOCKERS; BINDING; ABUSE; RATS AB Objective: This study assessed whether brain dopamine De receptor levels, which show significant intersubject variability, predict reinforcing responses to psychostimulants in humans. Method: [C-11]Raclopride and positron emission tomography were used to measure D-2 receptor levels in 23 healthy men (mean age=34 years, SD=7) who had no drug abuse histories in order to assess if there were differences between the subjects who liked and those who disliked the effects of intravenous methylphenidate (0.5 mg/kg). Results: Subjects who liked the effects of methylphenidate had significantly lower De receptor levels (mean=2.72 Bmax/Kd, SD=0.3) than subjects who disliked its effects (mean=3.16, SD=0.3). Moreover, the higher the D-2 levels found, the more intense were methylphenidate's unpleasant effects. Conclusions: These results provide preliminary evidence that D-2 receptor levels predict response to psychostimulants in humans and that low D-2 receptors may contribute to psychostimulant abuse by favoring pleasant response. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. RP Volkow, ND (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490, Upton, NY 11973 USA. FU NIDA NIH HHS [DA-06891] NR 21 TC 247 Z9 252 U1 2 U2 5 PU AMER PSYCHIATRIC PRESS, INC PI WASHINGTON PA 1400 K ST, N W, STE 1101, WASHINGTON, DC 20005 USA SN 0002-953X J9 AM J PSYCHIAT JI Am. J. Psychiat. PD SEP PY 1999 VL 156 IS 9 BP 1440 EP 1443 PG 4 WC Psychiatry SC Psychiatry GA 232FF UT WOS:000082359700023 PM 10484959 ER PT J AU Fisler, DK Cygan, RT AF Fisler, DK Cygan, RT TI Diffusion of Ca and Mg in calcite SO AMERICAN MINERALOGIST LA English DT Article ID OXYGEN DIFFUSION; SELF-DIFFUSION; METAMORPHISM; CONSTRAINTS; EQUILIBRIA; METEORITE AB The self-diffusion of Ca and the tracer diffusion of Mg in calcite have been measured experimentally using isotopic tracers of Mg-25 and Ca-44. Natural single crystals of calcite were coated with a thermally sputtered oxide thin film and then annealed in a CO2 gas at 1 atm total pressure and temperatures from 550 to 800 degrees C. Diffusion coefficient values were derived from the depth profiles obtained by ion microprobe analysis. The resultant activation energies for Mg tracer diffusion and Ca. self-diffusion are, respectively: E-a(Mg) = 284 +/- 74 kJ/mol and E-a(Ca) = 271 +/- 80 kJ/mol. For the temperature ranges in these experiments, the diffusion of Mg is faster than Ca. The results are generally consistent in magnitude with divalent cation diffusion rates obtained in previous studies, and provide a means of interpreting the thermal histories of carbonate minerals, the mechanism of dolomitization, and other diffusion-controlled processes. The results indicate that cation diffusion in calcite is relatively slow and cations are the rate-limiting diffusing species for the deformation of calcite and carbonate rucks. Application of the calcite-dolomite geothermometer to metamorphic assemblages will be constrained by cation diffusion and cooling rates. The direct measurement of Mg tracer diffusion in calcite indicates that dolomitization is unlikely to be accomplished by Mg diffusion in the solid state but by a recrystallization process. C1 Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. RP Fisler, DK (reprint author), Johns Manville Tech Ctr, 10100 W Ute Ave,POB 625005, Littleton, CO 80121 USA. NR 28 TC 46 Z9 46 U1 2 U2 18 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP PY 1999 VL 84 IS 9 BP 1392 EP 1399 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 232DD UT WOS:000082349700017 ER PT J AU Tagg, SL Cho, H Dyar, MD Grew, ES AF Tagg, SL Cho, H Dyar, MD Grew, ES TI Tetrahedral boron in naturally occurring tourmaline SO AMERICAN MINERALOGIST LA English DT Article ID CRYSTAL-CHEMISTRY; NMR; ENVIRONMENTS; PEGMATITE; MINERALS AB Evidence for boron in both trigonal and tetrahedral coordination ha, been found in B-11 magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) spectra of natural, inclusion-free specimens of aluminum-rich lithian tourmaline from granitic pegmatites. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Mt Holyoke Coll, Dept Geol & Geog, S Hadley, MA 01075 USA. Univ Maine, Dept Geol Sci, Orono, ME 04469 USA. RP Tagg, SL (reprint author), Micron Technol Inc, 8000 S Fed Way,MS 306,POB 6, Boise, ID 83707 USA. NR 31 TC 38 Z9 39 U1 0 U2 1 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP PY 1999 VL 84 IS 9 BP 1451 EP 1455 PG 5 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 232DD UT WOS:000082349700025 ER PT J AU Burns, PC Finch, RJ AF Burns, PC Finch, RJ TI Wyartite: Crystallographic evidence for the first pentavalent-uranium mineral SO AMERICAN MINERALOGIST LA English DT Article ID POWDER NEUTRON-DIFFRACTION; BOND-VALENCE PARAMETERS; SPENT NUCLEAR-FUEL; CORROSION; CHEMISTRY AB Determination of the structure of wyartite provides the first evidence for a pentavalent-U mineral. The structure of wyartite, CaU5+(UO2)(2)(CO3)O-4(OH)(H2O)(7), Z = 4, orthorhombic, a = 11.2706(8), b = 7.1055(5), c = 20.807(1) Angstrom, V = 1666.3(3) Angstrom(3), space group P2(1)2(1)2(1), was solved by direct methods and refined to an agreement index (R) of 4.9% for 2309 unique reflections collected using MoK alpha X-radiation and a CCD-based detector. The structure contains three unique U positions: two contain U6+ and involve uranyl ions with typical pentagonal-bipyramidal coordination. Seven anions coordinate the other U position, but there is no uranyl ion present. The polyhedral geometry, the bond-valence sum incident at this U site, and electroneutrality requirements, all indicate that this site contains U5+. The U phi(7) (phi: O, OH, H2O) polyhedra share edges and corners to form a unique sheet in which a CO3 group shares an edge with the U(5+)phi(7) polyhedron. The structure contains one Ca site coordinated by seven anions. The Ca atom and its associated H2O groups occupy interlayer sites, along with two H2O groups that are held in the structure by H bonds only. The Ca phi(7) polyhedron is linked to one adjacent sheet by sharing an edge with the CO3 group and an O atom with a U(6+)phi(7) polyhedron. Structural units are linked together through hydrogen bonds only. C1 Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Burns, PC (reprint author), Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. RI Finch, Robert/D-9553-2013; Burns, Peter/J-3359-2013; OI Finch, Robert/0000-0001-9342-5574; Burns, Peter/0000-0002-2319-9628 NR 26 TC 65 Z9 65 U1 5 U2 15 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP PY 1999 VL 84 IS 9 BP 1456 EP 1460 PG 5 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 232DD UT WOS:000082349700026 ER PT J AU Pokkuluri, PR Solomon, A Weiss, DT Stevens, FJ Schiffer, M AF Pokkuluri, PR Solomon, A Weiss, DT Stevens, FJ Schiffer, M TI Tertiary structure of human lambda 6 light chains SO AMYLOID-INTERNATIONAL JOURNAL OF EXPERIMENTAL AND CLINICAL INVESTIGATION LA English DT Article DE amyloid; x-ray crystallography; recombinant protein ID VARIABLE-REGION SUBGROUPS; MOLECULAR REPLACEMENT; GERMLINE GENE; AMYLOIDOSIS; PROTEIN; CRYSTALLOGRAPHY AB AL amyloidosis is a disease process characterized by the pathologic deposition of monoclonal light chains in tissue. To date, only limited information has been obtained on the molecular features that render such light chains amyloidogenic. Although protein products of the major human V-kappa and V-lambda gene families have been identified in AL deposits, one particular subgroup - lambda 6 - has been found to be preferentially associated with this disease. Notably, the variable region of lambda 6 proteins (V(lambda)6) has distinctive primary structural features including the presence in the third framework region (FR3) of two additional amino acid residues that distinguish members of this subgroup from other types of light chains. However, the structural consequences of these alterations have not been elucidated. To determine if lambda 6 proteins possess unique tertiary structural features, as compared to light chains of other V-lambda subgroups, we have obtained x-ray diffraction data on crystals prepared from two recombinant V(lambda)6 molecules. These components, isolated from a bacterial expression system, were generated from lambda 6-related cDNAs cloned from bone marrow-derived plasma cells from a patient (Wil) who had documented AL amyloidosis and another (Jto) with multiple myeloma and tubular cast nephropathy, but no evident fibrillar deposits. The xray crystallographic analyses revealed that the two-residue insertion located between positions 68 and 69 (not between 66 and 67 as previously surmised) extended an existing loop region that effectively increased the surface area adjacent to the first complementarity determining region (CDR1). Further, an unusual interaction between the Arg 25 and Phe 2 residues commonly found in lambda 6 molecules was noted. However, the structures of V(lambda)6 Wil and Jto also differed from each other, as evidenced by the presence in the latter of certain ionic and hydrophobic interactions that we posit increased protein stability and thus prevented amyloid formation. C1 Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. Univ Tennessee, Med Ctr, Human Immunol & Canc Program, Grad Sch Med, Knoxville, TN 37920 USA. RP Schiffer, M (reprint author), Argonne Natl Lab, Biosci Div, 9700 S Cass Ave,BIO-202, Argonne, IL 60439 USA. FU NCI NIH HHS [CA10056]; NIDDK NIH HHS [DK43757] NR 24 TC 38 Z9 39 U1 0 U2 7 PU PARTHENON PUBLISHING GROUP PI CARNFORTH LANCASHIRE PA CASTERTON HALL, CARNFORTH LANCASHIRE LA6 2LA, ENGLAND SN 1350-6129 J9 AMYLOID JI Amyloid-Int. J. Exp. Clin. Investig. PD SEP PY 1999 VL 6 IS 3 BP 165 EP 171 DI 10.3109/13506129909007322 PG 7 WC Biochemistry & Molecular Biology; Medicine, General & Internal; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; General & Internal Medicine; Research & Experimental Medicine GA 243CC UT WOS:000082978700002 PM 10524280 ER PT J AU Lazar, IM Ramsey, RS Sundberg, S Ramsey, JM AF Lazar, IM Ramsey, RS Sundberg, S Ramsey, JM TI Subattomole-sensitivity microchip nanoelectrospray source with time-of-flight mass spectrometry detection SO ANALYTICAL CHEMISTRY LA English DT Article ID MICROFABRICATED DEVICE; CAPILLARY ELECTROPHORESIS; PROTEIN IDENTIFICATIONS; ELECTROSPRAY; ATTOMOLE; SYSTEM AB A microfabricated microfluidic device coupled with a nanospray tip for electrospray ionization of dilute solutions is-described. The device has been interfaced with a time-of-flight mass spectrometer and evaluated for sensitive, high-speed detection of peptides and proteins. The electrospray: voltage was applied through the microchip to the nanospray capillary that was attached at the end of a microfabricated channel. Fluid delivery rates were 20-39 nL min(-1) through the hybridized structure without any pressure assistance. On-line microchip electrophoresis has been demonstrated and the effect of the capillary-chip junction on band broadening examined. Full mass spectra are acquired within 10-20 ms at 50-100 spectra s(-1) storage rates. Detection of subattomole levels of sample from a 100 nM solution is demonstrated for infusion experiments. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Caliper Technol Corp, Mt View, CA 94043 USA. RP Ramsey, JM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. OI Lazar, Iulia/0000-0001-7746-7889 NR 21 TC 128 Z9 129 U1 3 U2 24 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 SEP 1 PY 1999 VL 71 IS 17 BP 3627 EP 3631 DI 10.1021/ac990373m PG 5 WC Chemistry, Analytical SC Chemistry GA 232NY UT WOS:000082377900020 PM 21662870 ER PT J AU Dobson, JE Trimble, SW Dobson, JR Friend, DA AF Dobson, JE Trimble, SW Dobson, JR Friend, DA TI Kirk H. Stone, 1914-1997 - In memoriam SO ANNALS OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS LA English DT Biographical-Item C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Texas, Austin, TX 78712 USA. Princeton Univ, Woodrow Wilson Sch, Princeton, NJ 08544 USA. Univ Georgia, Athens, GA 30602 USA. RP Dobson, JE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU BLACKWELL PUBLISHERS PI MALDEN PA 350 MAIN STREET, STE 6, MALDEN, MA 02148 USA SN 0004-5608 J9 ANN ASSOC AM GEOGR JI Ann. Assoc. Am. Geogr. PD SEP PY 1999 VL 89 IS 3 BP 535 EP 548 DI 10.1111/0004-5608.00161 PG 14 WC Geography SC Geography GA 230JX UT WOS:000082249000008 ER PT J AU Maness, PC Smolinski, S Blake, DM Huang, Z Wolfrum, EJ Jacoby, WA AF Maness, PC Smolinski, S Blake, DM Huang, Z Wolfrum, EJ Jacoby, WA TI Bactericidal activity of photocatalytic TiO2 reaction: Toward an understanding of its killing mechanism SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID LIPID-PEROXIDATION PRODUCTS; ESCHERICHIA-COLI; SEMICONDUCTOR PHOTOCATALYSIS; MALONDIALDEHYDE; WATER; CELLS; STERILIZATION; SUPEROXIDE; ADDUCTS; POWDERS AB When titanium dioxide (TiO2) is irradiated with near-UV light, this semiconductor exhibits strong bactericidal activity. In this paper, we present the first evidence that the lipid peroxidation reaction is the underlying mechanism of death of Escherichia call K-12 cells that are irradiated in the presence of the TiO2 photocatalyst, Using production of malondialdehyde (MDA) as an index to assess cell membrane damage by lipid peroxidation, we observed that there was an exponential increase in the, production of MDA, whose concentration reached 1.1 to 2.4 nmol - mg (dry weight) of cells(-1) after 30 min of illumination, and that the kinetics of this process paralleled cell death. Under these conditions, concomitant losses of 77 to 93% of the cell respiratory activity were also detected, as measured by both oxygen uptake and reduction of 2,3,5-triphenyltetrazolium chloride from succinate as the electron donor. The occurrence of lipid peroxidation and the simultaneous losses of both membrane-dependent respiratory activity and cell viability depended strictly on the presence of both light and TiO2. We concluded that TiO2 photocatalysis promoted peroxidation of the polyunsaturated phospholipid component of the lipid membrane initially and induced major disorder in the E. call cell membrane, Subsequently, essential functions that rely on intact cell membrane architecture, such as respiratory activity, were lost, and cell death was inevitable. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Missouri, Dept Chem Engn, Columbia, MO 65211 USA. RP Maness, PC (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 36 TC 747 Z9 780 U1 32 U2 261 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD SEP PY 1999 VL 65 IS 9 BP 4094 EP 4098 PG 5 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 233HL UT WOS:000082421400050 PM 10473421 ER PT J AU Takacs, PZ Church, EL Bresloff, CJ Assoufid, L AF Takacs, PZ Church, EL Bresloff, CJ Assoufid, L TI Improvements in the accuracy and the repeatability of long trace profiler measurements SO APPLIED OPTICS LA English DT Article ID COMPENSATION; SURFACES; FLATNESS AB Modifications of the long trace profiler at the Advanced Photon Source at Argonne National Laboratory have significantly improved its accuracy and repeatability for measuring the figure of large flat and long-radius mirrors. Use of a Dove prism in the reference beam path corrects phasing problems between mechanical errors and thermally induced system errors. A single reference correction now completely removes both of these error signals from the measured surface profile. The addition of a precision air conditioner keeps the temperature in the metrology enclosure constant to within +/-0.1 degrees C over a 24-h period and has significantly improved the stability and the repeatability of the measurements. Long-radius surface curvatures can now be measured absolutely with a high degree of confidence. These improved capabilities are illustrated with a series of measurements of a 500-mm-long mirror with a 5-km radius of curvature. The standard deviation in the average of ten slope profile scans is 0.3 mu rad, and the corresponding standard deviation in the height error is 4.6 nm. (C) 1999 Optical Society of America. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Takacs, PZ (reprint author), Brookhaven Natl Lab, POB 5000, Upton, NY 11973 USA. EM takacs@bnl.gov NR 29 TC 41 Z9 43 U1 2 U2 5 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 SEP 1 PY 1999 VL 38 IS 25 BP 5468 EP 5479 DI 10.1364/AO.38.005468 PG 12 WC Optics SC Optics GA 232JQ UT WOS:000082367900030 PM 18324056 ER PT J AU Nygard, J Cobden, DH Bockrath, M McEuen, PL Lindelof, PE AF Nygard, J Cobden, DH Bockrath, M McEuen, PL Lindelof, PE TI Electrical transport measurements on single-walled carbon nanotubes SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID ELECTRONIC-STRUCTURE; QUANTUM TRANSPORT; CRYSTALLINE ROPES; ATOMIC-STRUCTURE; RESISTIVITY; CONDUCTIVITY AB We review transport measurements on single-walled carbon nanotubes contacted by metal electrodes. At room temperature some devices show transistor action similar to that of p-channel field effect transistors, while others behave as gate-voltage independent wires. At low temperatures transport is usually dominated by Coulomb blockade. In this regime the quantum eigenstates of the finite-length tubes can be studied. At higher temperatures power law behaviour is observed for the temperature and bias dependence of the conductance. This is consistent with tunneling into a one-dimensional Luttinger liquid in a nanotube. We also discuss recent developments in contacting nanotubes which should soon allow study of their intrinsic transport properties. C1 Niels Bohr Inst, Orsted Lab, DK-2100 Copenhagen, Denmark. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Niels Bohr Inst, Orsted Lab, Univ Parken 5, DK-2100 Copenhagen, Denmark. EM nygard@nbi.dk RI 李, 府中/H-4357-2011; Nygard, Jesper/F-5113-2014 OI Nygard, Jesper/0000-0002-4639-5314 NR 42 TC 149 Z9 151 U1 0 U2 38 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0947-8396 EI 1432-0630 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD SEP PY 1999 VL 69 IS 3 BP 297 EP 304 DI 10.1007/s003390051004 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 231JE UT WOS:000082304200007 ER PT J AU Pierce, WM Janczewski, JN Roethlisberger, B Janczewski, MG AF Pierce, WM Janczewski, JN Roethlisberger, B Janczewski, MG TI Air quality on commercial aircraft SO ASHRAE JOURNAL LA English DT Article C1 Consolidated Safety Serv, Ind Hyg & Safety Div, Fairfax, VA USA. Idaho Natl Environm & Engn Lab, Lockheed Martin Idaho Technol, Idaho Falls, ID 83401 USA. USAF, Aeromed Serv, Washington, DC 20330 USA. RP Pierce, WM (reprint author), Consolidated Safety Serv, Ind Hyg & Safety Div, Fairfax, VA USA. NR 3 TC 29 Z9 29 U1 1 U2 1 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD SEP PY 1999 VL 41 IS 9 BP 26 EP + PG 8 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 237UL UT WOS:000082674400008 ER PT J AU Vidaver, AK Doyle, MP Gerone, PJ Gonzalez, CF Hall, P Hunter-Cevera, JC Loria, R Newsome, RL Shore, SH Wilkins, T AF Vidaver, AK Doyle, MP Gerone, PJ Gonzalez, CF Hall, P Hunter-Cevera, JC Loria, R Newsome, RL Shore, SH Wilkins, T TI Burkholderia cepacia - Friend or foe? SO ASM NEWS LA English DT Letter C1 Univ Nebraska, Lincoln, NE USA. Univ Georgia, Ctr Food Safety & Qual Enhancement, Athens, GA 30602 USA. Tulane Univ, Reg Primate Ctr, Covington, LA 70433 USA. Texas A&M Univ, College Stn, TX USA. Kraft Gen Foods Inc, Glenview, IL 60025 USA. Lawrence Berkeley Lab, Ctr Environm Biotechnol, El Cerrito, CA USA. Cornell Univ, Ithaca, NY USA. Inst Food Technol, Chicago, IL USA. Novo Nordisk Biochem N Amer Inc, Franklinton, NC USA. Virginia Polytech Inst & State Univ, Fralin Biotechnol Ctr, Blacksburg, VA 24061 USA. NR 3 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0044-7897 J9 ASM NEWS JI ASM News PD SEP PY 1999 VL 65 IS 9 BP 587 EP 587 PG 1 WC Microbiology SC Microbiology GA 235TD UT WOS:000082557900006 ER PT J AU Verschuur, GL Peratt, AL AF Verschuur, GL Peratt, AL TI Galactic neutral hydrogen emission profile structure SO ASTRONOMICAL JOURNAL LA English DT Article DE ISM : atoms; ISM : general-ISM : HI; physical data and processes ID FILAMENTS; LATITUDES; HALO; ERIDANUS; CLOUDS; SPACE; GAS; HI AB Analysis of Galactic neutral hydrogen emission profiles that have been corrected for sidelobe radiation confirm the existence of three distinct component line width regimes identified by Verschuur & Magnani in 1994. In addition, a fourth becomes recognizable in the data in directions of low total column density. The line width regimes are around 50 km s(-1) (component la), 31 km s(-1) (component 1b), 13 km s(-1) (component 2), and 5.2 km s(-1) for the narrow lines arising from cool H I (component 3). In this paper, the new data are presented and compared with previously published results. The possible origin of the distinct line width regimes is briefly examined, and it is concluded that a new interpretation is needed, one that involves a plasma phenomenon known as the critical ionization velocity, which will be fully discussed in a subsequent paper. C1 Univ Memphis, Dept Phys, Memphis, TN 38152 USA. US DOE, Washington, DC 20585 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Verschuur, GL (reprint author), Univ Memphis, Dept Phys, Memphis, TN 38152 USA. NR 33 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 1999 VL 118 IS 3 BP 1252 EP 1267 DI 10.1086/300998 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241ZR UT WOS:000082914200013 ER PT J AU Breger, M Handler, G Garrido, R Audard, N Zima, W Paparo, M Beichbuchner, F Li, ZP Jiang, SY Liu, ZI Zhou, AY Pikall, H Stankov, A Guzik, JA Sperl, M Krzesinski, J Ogloza, W Pajdosz, G Zola, S Thomassen, T Solheim, JE Serkowitsch, E Reegen, P Rumpf, T Schmalwieser, A Montgomery, MH AF Breger, M Handler, G Garrido, R Audard, N Zima, W Paparo, M Beichbuchner, F Li, ZP Jiang, SY Liu, ZI Zhou, AY Pikall, H Stankov, A Guzik, JA Sperl, M Krzesinski, J Ogloza, W Pajdosz, G Zola, S Thomassen, T Solheim, JE Serkowitsch, E Reegen, P Rumpf, T Schmalwieser, A Montgomery, MH TI 30+frequencies for the delta Scuti variable 4 Canum Venaticorum: results of the 1996 multisite campaign SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : variables : delta Sct; stars : oscillations; stars : individual : AI CVn; stars : individual : 4 CVn ID PULSATING STARS; MICROVARIABILITY AB The evolved delta Scuti variable 4 CVn was observed photometrically for 53 nights on three continents. We found a total of 34 significant and 1 probable simultaneously excited frequencies. Of these, 16 can be identified as linear combinations of other frequencies. All significant frequencies outside the 4.5 to 10 cd(-1) (52 to 116 mu Hz) range can be identified with frequency combinations, f(i) +/- f(j), of other modes with generally high amplitudes. There exists a number of closely spaced frequencies with separations of similar to 0.06 cd(-1). This cannot be explained in terms of amplitude variability. The results show that even for stars on and above the main sequence other than the Sun, a very large number of simultaneously excited nonradial oscillations can be detected by conventional means. Since all pulsation modes with photometric amplitudes of 1 mmag or larger have now been detected for this star, a presently unknown mode selection mechanism must exist to select between the 1000+ of low-degree modes predicted to be excited for this (and many other) stars. Phase differences and amplitude ratios between the y and v colors are determined for the ten main modes. The phase differences indicate p(1) to p(4) modes of l = 1 for four of these modes. The formulae to determine the uncertainties in the amplitudes and phases of sinusoidal fits to observational data are derived in the Appendix. C1 Univ Vienna, Inst Astron, A-1180 Vienna, Austria. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. Konkoly Observ Budapest, H-1525 Budapest, Hungary. Chinese Acad Sci, Beijing Astron Observ, Beijing 100080, Peoples R China. Univ Calif Los Alamos Natl Lab, XTA, Los Alamos, NM 87545 USA. Cracow Pedagog Univ, Mt Suhora Observ, PL-30083 Krakow, Poland. Jagiellonian Univ, PL-30244 Krakow, Poland. Univ Tromso, Dept Phys, N-9037 Tromso, Norway. RP Breger, M (reprint author), Univ Vienna, Inst Astron, Turkenschanzstr 17, A-1180 Vienna, Austria. EM breger@astro.univie.ac.at RI Schmalwieser, Alois/B-3748-2011 OI Schmalwieser, Alois/0000-0003-0719-391X NR 21 TC 95 Z9 96 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 1999 VL 349 IS 1 BP 225 EP 235 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 241YY UT WOS:000082912500030 ER PT J AU Ruffini, R Salmonson, JD Wilson, JR Xue, SS AF Ruffini, R Salmonson, JD Wilson, JR Xue, SS TI On evolution of the pair-electromagnetic pulse of a charged black hole SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article; Proceedings Paper CT Workshop on Gamma-Ray Bursts in the Afterglow Era CY NOV 03-06, 1998 CL CNR HEADQUARTERS, ROME, ITALY HO CNR HEADQUARTERS DE black hole physics; gamma-ray bursts, theory, observations AB Using hydrodynamic computer codes, we study the possible patterns of relativistic expansion of an enormous pair-electromagnetic-pulse (P.E.M. pulse); a hot, high density plasma composed of photons, electron-positron pairs and baryons deposited near a charged black hole (EMBH). On the bases of baryon-loading and energy conservation, we study the bulk Lorentz factor of expansion of the P.E.M. pulse by both numerical and analytical methods. C1 Univ Rome La Sapienza, ICRA, I-00185 Rome, Italy. Univ Rome La Sapienza, Dept Phys, I-00185 Rome, Italy. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Ruffini, R (reprint author), Univ Rome La Sapienza, ICRA, Piazzale Aldo Moro 5, I-00185 Rome, Italy. NR 7 TC 17 Z9 17 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD SEP PY 1999 VL 138 IS 3 BP 511 EP 512 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246GM UT WOS:000083156100052 ER PT J AU Ramirez-Ruiz, E Fenimore, EE AF Ramirez-Ruiz, E Fenimore, EE TI Temporal evolution of the pulse width in GRBs SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article; Proceedings Paper CT Workshop on Gamma-Ray Bursts in the Afterglow Era CY NOV 03-06, 1998 CL CNR HEADQUARTERS, ROME, ITALY HO CNR HEADQUARTERS DE gamma-ray : bursts ID GAMMA-RAY BURSTS AB Many cosmological models of GRBs envision the energy source to be a cataclysmic stellar event leading to a relativistically expanding fireball. Particles are thought to be accelerated at shocks and produce nonthermal radiation. The highly variable temporal structure observed in most GRBs has significantly constrained models. By using different methods of statistical analysis in the time domain we show that the width of the pulses in GRBs time histories remain remarkably constant throughout the classic GRB phase. If the emission sites lie on a relativistically expanding shell, we determine both the amount of deceleration and the angular spread of the emitting region from the time dependency of the pulse width. We find no deceleration over at least 2/3 of the burst duration and angular spreads of the complete emitting shell that are substancially smaller than Gamma(-1). The lack of temporal evolution of the pulse width should be explained by any fireball shock scenario. C1 Natl Autonomous Univ Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ramirez-Ruiz, E (reprint author), Natl Autonomous Univ Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. NR 6 TC 21 Z9 21 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD SEP PY 1999 VL 138 IS 3 BP 521 EP 522 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246GM UT WOS:000083156100057 ER PT J AU Kawai, N Matsuoka, M Yoshida, A Shirasaki, Y Namiki, M Takagishi, K Yamauchi, M Hatsukade, I Fenimore, EE Galassi, M AF Kawai, N Matsuoka, M Yoshida, A Shirasaki, Y Namiki, M Takagishi, K Yamauchi, M Hatsukade, I Fenimore, EE Galassi, M TI Wide-field X-ray monitor on HETE-2 SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article; Proceedings Paper CT Workshop on Gamma-Ray Bursts in the Afterglow Era CY NOV 03-06, 1998 CL CNR HEADQUARTERS, ROME, ITALY HO CNR HEADQUARTERS DE instrumentation : detectors; gamma-rays : bursts; X-rays : general AB The Wide-field X-ray Monitor on HETE-2 consists of four Xe-filled 1-D position-sensitive proportional counters. It is sensitive to X-rays between 2 keV and 25 keV, and is designed to localize gamma-ray bursts in real time with similar to 10' accuracy. The design and basic characteristics of the detectors are presented. C1 Inst Phys & Chem Res, RIKEN, Wako, Saitama 3510198, Japan. Miyazaki Univ, Fac Engn, Miyazaki 8802155, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kawai, N (reprint author), Inst Phys & Chem Res, RIKEN, 2-1 Hirosawa, Wako, Saitama 3510198, Japan. NR 2 TC 5 Z9 5 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD SEP PY 1999 VL 138 IS 3 BP 563 EP 564 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246GM UT WOS:000083156100076 ER PT J AU Park, HS Porrata, RA Williams, GG Ables, E Band, DL Barthelmy, SD Bionta, RM Cline, TL Fishman, GJ Gehrels, N Hartmann, D Hurley, K Kouveliotou, C Meegan, CA AF Park, HS Porrata, RA Williams, GG Ables, E Band, DL Barthelmy, SD Bionta, RM Cline, TL Fishman, GJ Gehrels, N Hartmann, D Hurley, K Kouveliotou, C Meegan, CA TI LOTIS: GRB follow-up observations at early times SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article; Proceedings Paper CT Workshop on Gamma-Ray Bursts in the Afterglow Era CY NOV 03-06, 1998 CL CNR HEADQUARTERS, ROME, ITALY HO CNR HEADQUARTERS DE gamma-rays : bursts ID GAMMA-RAY BURST; 28 FEBRUARY 1997; OPTICAL-EMISSION; AFTERGLOW AB LOTIS is an automated wide field-of-view telescope system capable of responding to GRB events as early as 10 s after a trigger from the GCN which rapidly distributes coordinates from the BeppoSAX, BATSE and RXTE instruments. Measurements of optical activity at these early times will provide important clues to the GRB production mechanism. In over two year's of operation, LOTIS has responded to 40 GCN triggers including GRB 971227 within 10 s and GRB 980703 within 5 hours. We report results from these events and constraints on simultaneous optical signals during these GRBs. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Space Res Assoc, Washington, DC USA. RP Park, HS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Barthelmy, Scott/D-2943-2012 NR 10 TC 13 Z9 13 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD SEP PY 1999 VL 138 IS 3 BP 577 EP 578 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246GM UT WOS:000083156100083 ER PT J AU Strauss, MA Fan, XH Gunn, JE Leggett, SK Geballe, TR Pier, JR Lupton, RH Knapp, GR Annis, J Brinkmann, J Crocker, JH Csabai, I Fukugita, M Golimowski, DA Harris, FH Hennessy, GS Hindsley, RB Ivezic, Z Kent, S Lamb, DQ Munn, JA Newberg, HJ Rechenmacher, R Schneider, DP Smith, JA Stoughton, C Tucker, DL Waddell, P York, DG AF Strauss, MA Fan, XH Gunn, JE Leggett, SK Geballe, TR Pier, JR Lupton, RH Knapp, GR Annis, J Brinkmann, J Crocker, JH Csabai, I Fukugita, M Golimowski, DA Harris, FH Hennessy, GS Hindsley, RB Ivezic, Z Kent, S Lamb, DQ Munn, JA Newberg, HJ Rechenmacher, R Schneider, DP Smith, JA Stoughton, C Tucker, DL Waddell, P York, DG TI The discovery of a field methane dwarf from Sloan Digital Sky Survey commissioning data SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : low-mass, brown dwarfs; surveys ID EXTRASOLAR GIANT PLANETS; COOL BROWN DWARF; GLIESE 229B; INFRARED SPECTRUM; SEARCH; DENIS; STARS AB We report the discovery of the coolest field dwarf yet known, selected as an unresolved object with extremely red colors from commissioning imaging data of the Sloan Digital Sky Survey. Its spectrum from 0.8 to 2.5 mu m is dominated by strong bands of H(2)O and CH(4). Its spectrum and colors over this range are very similar to those of Gl 229B, the only other known example of a methane dwarf. It is roughly 1.2 mag fainter than Gl 229B, suggesting that it lies at a distance of similar to 10 pc. Such a cool object must have a mass well below the hydrogen-burning limit of 0.08 M. and therefore is a genuine brown dwarf, with a probable mass in the range 0.015-0.06 M. for an age range of 0.3-5 Gyr. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Joint Astron Ctr, United Kingdom Infrares Telescope, Hilo, HI 96720 USA. Gemini N Observ, Hilo, HI 96720 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Apache Point Observ, Sunspot, NM 88349 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. Univ Tokyo, Inst Cosm Ray Res, Tanashi, Tokyo 1888502, Japan. USN Observ, Washington, DC 20392 USA. Univ Chicago, Ctr Astron & Astrophys, Chicago, IL 60637 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. RP Strauss, MA (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. RI Csabai, Istvan/F-2455-2012; OI Smith, J. Allyn/0000-0002-6261-4601; Tucker, Douglas/0000-0001-7211-5729 NR 43 TC 166 Z9 166 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 1999 VL 522 IS 1 BP L61 EP L64 DI 10.1086/312218 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228HL UT WOS:000082131000015 ER PT J AU Lehnert, MD van Breugel, WJM Heckman, TM Miley, GK AF Lehnert, MD van Breugel, WJM Heckman, TM Miley, GK TI Hubble Space Telescope imaging of the host galaxies of high-redshift radio-loud quasars SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : evolution; galaxies : structure; quasars : general; ultraviolet : galaxies ID NEARBY LUMINOUS QUASARS; STAR-FORMING GALAXIES; STELLAR OBJECTS; SPECTROSCOPY; EMISSION; ULTRAVIOLET; ABSORPTION; JET; EVOLUTION; ALIGNMENT AB We present rest-frame UV and Ly alpha images of spatially resolved structures ("hosts") around five high-redshift radio-loud quasars obtained with the WFPC2 camera on the Hubble Space Telescope (HST). The quasars were imaged with the PC1 through the F555W ("V"-band) filter, which at the redshifts of the quasars (2.1 < z < 2.6) have central wavelengths of lambda(rest) approximate to 1500-1800 Angstrom and at rest-frame Ly alpha using appropriately chosen narrowband filters with the WFC2 The objects were selected from ground-based imaging surveys. Those had shown that many radio-loud quasars at high redshift have prominent host galaxies that appeared to have properties similar to those of high-redshift radio galaxies. Our HST observations allow a more detailed investigation of quasar host morphologies and a comparison with similar HST studies of radio galaxies by others. Using several methods to measure and quantify the host properties we find that all five quasars are extended and that this "fuzz" contains approximate to 5%-40% of the total continuum flux and 15%-65% of the Ly alpha flux within a radius of about 1." 5. The rest-frame UV luminosities of the hosts are log lambda P(lambda) approximate to 11.9-12.5 L. (assuming no internal dust extinction), comparable to the luminous radio galaxies at similar redshifts and a factor 10 higher than both radio-quiet field galaxies at z similar to 2-3 and the most UV-luminous low-redshift starburst galaxies. The Ly alpha luminosities of the hosts are log L(Ly alpha) approximate to 44.3-44.9 ergs s(-1), which are also similar to the those of luminous high-redshift radio galaxies and considerably larger than the Ly alpha luminosities of high-redshift held galaxies. To generate the Ly alpha luminosities of the hosts would require roughly a few percent of the total observed ionizing luminosity of the quasar. The UV continuum morphologies of the hosts appear complex and knotty at the relatively high surface brightness levels of our exposures (about 24 V mag arcsec(-2)). In two quasars we find evidence for foreground galaxies that confuse the host galaxy morphologies and that are responsible for some of the perceived radio/optical misalignments observed in ground-based imaging data. We do find good alignment between the extended Ly alpha and the radio sources, strong evidence for jet-cloud interactions in two cases, again resembling radio galaxies, and what is possibly the most luminous radio-UV synchrotron jet in one of the hosts at z = 2.110. We discuss the significance of jet-cloud collisions in radio-loud quasars and their influence on radio morphologies in the framework of simple orientation-based quasar/radio galaxy unification schemes. Our observations suggest that the host galaxies of radio-loud steep-spectrum quasars are similar to those of radio galaxies and strengthen previous conclusions based on ground-based data that both types of objects are probably members of the same parent population. C1 Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Lehnert, MD (reprint author), Max Planck Inst Extraterr Phys, Postfach 1603, D-85740 Garching, Germany. EM mlehnert@mpe.mpg.de NR 80 TC 25 Z9 25 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 1999 VL 124 IS 1 BP 11 EP 31 DI 10.1086/313252 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 243BQ UT WOS:000082977600002 ER PT J AU Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Griest, K Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, A Vandehei, T Welch, DL AF Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Griest, K Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, A Vandehei, T Welch, DL CA MACHO Collaboration TI Difference image analysis of galactic microlensing. II. Microlensing events SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atmospheric effects; Galaxy : stellar content; gravitational lensing; techniques : image processing ID MACHO PROJECT; BULGE; STARS AB The MACHO collaboration has been carrying out difference image analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing. This is a preliminary report on the application of DIA to galactic bulge images in one field. We show how the DIA technique significantly increases the number of detected lensing events, by removing the positional dependence of traditional photometry schemes and lowering the microlensing event detection threshold. This technique, unlike PSF photometry, gives the unblended colors and positions of the microlensing source stars. We present a set of criteria for selecting microlensing events from objects discovered with this technique. The 16 pixel and classical microlensing events discovered with the DIA technique are presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Univ Calif Berkeley, Dept Phys, Berkeley, CA 95616 USA. Mt Stromlo & Siding Spring Observ, Canberra, ACT 2611, Australia. Univ Washington, Dept Phys & Astron, Seattle, WA 98195 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. MIT, Ctr Space Res, Cambridge, MA 02139 USA. European So Observ, D-85748 Garching, Germany. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 18 TC 26 Z9 26 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 1999 VL 124 IS 1 BP 171 EP 179 DI 10.1086/313258 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 243BQ UT WOS:000082977600006 ER PT J AU Xu, YW Carmichael, GR AF Xu, YW Carmichael, GR TI An assessment of sulfur deposition pathways in Asia SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 214th National Meeting of the American-Chemical-Society CY SEP 07-11, 1997 CL LAS VEGAS, NEVADA SP Amer Chem Soc, Div Geochem DE deposition modeling; wet deposition; dry deposition; sulfur deposition in Asia ID MODEL; SULFATE; PRECIPITATION; DIOXIDE; SO2 AB The acid deposition model is developed and applied to assess the sulfur deposition pathways in Asia. Simulations for four seasons are conducted: February, April, August, and October. The predicted results of summer and winter are compared to measured concentration of SO,, sulfate, and sulfate wet deposition in Japan. Further comparison of sulfate wet deposition to observations in China is made to assess the general performance of the model. The study shows that wet deposition is more important than dry deposition. It is the predominant factor in each of these four months. It is also found that rainout process, compared to washout process, make a larger contribution to sulfate wet deposition in summer and spring than in the dry months, such as October. The total sulfur wet to dry deposition ratio is 1.6 in February, 1.2 in April, 2.9 in August, and 1.9 in October. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Iowa, Ctr Global & Reg Environm Res, Dept Biochem & Chem Egnn, Iowa City, IA 52242 USA. RP Xu, YW (reprint author), Argonne Natl Lab, 203ER, Argonne, IL 60437 USA. NR 33 TC 17 Z9 19 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 1999 VL 33 IS 21 BP 3473 EP 3486 DI 10.1016/S1352-2310(98)00356-2 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 207GJ UT WOS:000080927500005 ER PT J AU Han, XL Wu, CL AF Han, XL Wu, CL TI Nuclear superdeformation data tables SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID MEAN-FIELD-THEORY; ROTATIONAL BANDS; IDENTICAL BANDS; MASS REGION; DECAY; SPIN; SEARCH; HG-192; PB-194; STATES AB This paper updates the earlier compilation of Nuclear superdeformation data tables (data cutoff at July 1995) published in ATOMIC DATA AND NUCLEAR DATA TABLES 63, 117 (1996). The present tables list the measured gamma-transition energies E-gamma of 248 nuclear superdeformed bands for 90 nuclei found in the mass-60, -80, -130, -140, -150, -160, and -190 regions. Data were collected up to July 1998. The corresponding rotational frequencies omega, dynamic moments of inertia J((2)), measured or suggested spin assignments I and associated static moments of inertia J((1)), available transition quadrupole moments Q(t) or average moments Q(0), M1 or E1 interband transition energies and parities, and g-factors are also tabulated. For the user's convenience, a plot of J((1)) and J((2)) versus rotational frequency omega is given with the data table for each superdeformed band. C1 Chung Yuan Christian Univ, Dept Phys, Chungli 32023, Taiwan. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RP Han, XL (reprint author), Chung Yuan Christian Univ, Dept Phys, Chungli 32023, Taiwan. NR 27 TC 53 Z9 53 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD SEP PY 1999 VL 73 IS 1 BP 43 EP 150 DI 10.1006/adnd.1999.0817 PG 108 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 246FD UT WOS:000083153000002 ER PT J AU van Holde, K Zlatanova, J AF van Holde, K Zlatanova, J TI The nucleosome core particle: does it have structural and physiologic relevance? SO BIOESSAYS LA English DT Article ID MICROCOCCAL NUCLEASE; CHROMATIN; DNA; RESOLUTION; DIGESTION; HISTONES AB Although the nucleosomal core particle has been extensively studied as the basic building block of chromatin, the biological significance of a unit carrying exactly 146 bp of DNA remains unclear. Herein, we present data to show that the histone octamer can stably accommodate anywhere from:about 100 to 170 bp of DNA. The unfolded structures containing less than 146 bp may well be of greater biological importance than the canonical core particle. (C) 1999 John Wiley & Sons, Inc. C1 Oregon State Univ, Dept Biochem & Biophys, Corvallis, OR 97331 USA. RP Zlatanova, J (reprint author), Argonne Natl Lab, Biochip Technol Ctr, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zlatanova, Jordanka/B-3273-2009 NR 21 TC 32 Z9 32 U1 0 U2 2 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE CB4 4DL, CAMBS, ENGLAND SN 0265-9247 J9 BIOESSAYS JI Bioessays PD SEP PY 1999 VL 21 IS 9 BP 776 EP 780 DI 10.1002/(SICI)1521-1878(199909)21:9<776::AID-BIES9>3.3.CO;2-Q PG 5 WC Biochemistry & Molecular Biology; Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics GA 232PJ UT WOS:000082378900009 PM 10462418 ER PT J AU Goryanin, I Hodgman, TC Selkov, E AF Goryanin, I Hodgman, TC Selkov, E TI Mathematical simulation and analysis of cellular metabolism and regulation SO BIOINFORMATICS LA English DT Article ID PATHWAY COLLECTION; SOFTWARE; BIOCHEMISTRY; PROGRAM; SYSTEMS AB Motivation: A better understanding of the biological phenomena observed in cells requires the creation and analysis of mathematical models of cellular metabolism and physiology. The formulation and study of such models must also be simplified as far as possible to cope with the increasing complexity demanded and exponential accumulation of the metabolic reconstructions computed front sequenced genomes. Results: A mathematical simulation workbench, DBsolve, has been developed to simplify the derivation and analysis of mathematical models. It combines: (i) derivation of large-scale mathematical models from metabolic reconstructions and other data sources; (ii) solving and parameter continuation of non-linear algebraic equations (NAEs), including metabolic control analysis; (iii) solving the non-linear stiff systems of ordinary differential equations (ODEs); (iv) bifurcation analysis of ODEs; (v) parameter fitting to experimental data or functional criteria based on constrained optimization. The workbench has been successfully used for dynamic metabolic modeling of some typical biochemical networks (Dolgacheva et nl., Biochemistry (Moscow), 6 1063-1068, 1996; Goklstein and Goryanin, Mol. Biol, (Moscow), 30, 976-983, 1996), including microbial glycolytic pathways, signal transduction pathways and receptor-ligand interactions. C1 Russian Acad Sci, Lab Metab Modeling & Bioinformat, Pushchino 142292, Moscow Region, Russia. GlaxoWellcome Med Res Ctr, Adv Technol & Informat Unit, Stevenage SG1 2NY, Herts, England. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Goryanin, I (reprint author), Russian Acad Sci, Lab Metab Modeling & Bioinformat, Pushchino 142292, Moscow Region, Russia. OI Hodgman, Charlie/0000-0001-5862-8296 NR 27 TC 91 Z9 95 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP PY 1999 VL 15 IS 9 BP 749 EP 758 DI 10.1093/bioinformatics/15.9.749 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 247DJ UT WOS:000083205100006 PM 10498775 ER PT J AU Fischer, D Eisenberg, D AF Fischer, D Eisenberg, D TI Finding families for genomic ORFans SO BIOINFORMATICS LA English DT Article ID PROTEINS; FOLDS C1 Ben Gurion Univ Negev, Dept Math & Comp Sci, Fac Nat Sci, IL-84015 Beer Sheva, Israel. Univ Calif Los Angeles, Inst Mol Biol, UCLA DOE Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. RP Fischer, D (reprint author), Ben Gurion Univ Negev, Dept Math & Comp Sci, Fac Nat Sci, IL-84015 Beer Sheva, Israel. NR 13 TC 144 Z9 145 U1 1 U2 5 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP PY 1999 VL 15 IS 9 BP 759 EP 762 DI 10.1093/bioinformatics/15.9.759 PG 4 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 247DJ UT WOS:000083205100007 PM 10498776 ER PT J AU Kyrpides, NC AF Kyrpides, NC TI Genomes OnLine Database (GOLD 1.0): a monitor of complete and ongoing genome projects world-wide SO BIOINFORMATICS LA English DT Article ID DNA AB GOLD (Genomes On Line Database) is a World Wide Web resource for comprehensive access to information regarding complete and ongoing genome projects around the world. C1 Univ Illinois, Dept Microbiol, Urbana, IL 61801 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Kyrpides, NC (reprint author), Univ Illinois, Dept Microbiol, B103 Chem & Life Sci,MC 110,407 S Goodwin, Urbana, IL 61801 USA. RI Kyrpides, Nikos/A-6305-2014 OI Kyrpides, Nikos/0000-0002-6131-0462 NR 4 TC 52 Z9 58 U1 1 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP PY 1999 VL 15 IS 9 BP 773 EP 774 DI 10.1093/bioinformatics/15.9.773 PG 2 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 247DJ UT WOS:000083205100013 PM 10498782 ER PT J AU Wong, JY Majewski, J Seitz, M Park, CK Israelachvili, JN Smith, GS AF Wong, JY Majewski, J Seitz, M Park, CK Israelachvili, JN Smith, GS TI Polymer-cushioned bilayers. I. A structural study of various preparation methods using neutron reflectometry SO BIOPHYSICAL JOURNAL LA English DT Article ID PHOSPHOLIPID MONOLAYERS; SUPPORTED MONOLAYERS; LIPID-MONOLAYER; X-RAY; FUSION; REFLECTION; MEMBRANES; INTERFACES; MICROSCOPY; VESICLES AB This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine (DMPC) bilayer onto a polyethylenimine (PEI)-coated quartz substrate were examined: 1) vesicle adsorption onto a previously dried polymer layer; 2) vesicle adsorption onto a bare substrate, followed by polymer adsorption; and 3, 4) Langmuir-Blodgett vertical deposition of a lipid monolayer spread over a polymer-containing subphase to form a polymer-supported lipid monolayer, followed by formation of the outer lipid monolayer by either 3) horizontal deposition of the lipid monolayer or 4) vesicle adsorption. We show that the initial conditions of the polymer layer are a critical factor for the successful formation of our desired structure, i.e., a continuous bilayer atop a hydrated PEI layer. Our desired structure was found for all methods investigated except the horizontal deposition. The interaction forces between these polymer-supported bilayers are investigated in a separate paper (Wong, J. Y., C. K. Park, M. Seitz, and J. Israelachvili. 1999. Biophys. J. 77:1458-1463), which indicate that the presence of the polymer cushion significantly alters the interaction potential. These polymer-supported bilayers could serve as model systems for the study of transmembrane proteins under conditions more closely mimicking real cellular membrane environments. C1 Univ Calif Los Alamos Natl Lab, Los Alamos Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. RP Smith, GS (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos Neutron Scattering Ctr, H805, Los Alamos, NM 87545 USA. RI Wong, Joyce/F-3732-2011; Lujan Center, LANL/G-4896-2012 OI Wong, Joyce/0000-0002-3526-6381; FU NIGMS NIH HHS [GM17876] NR 32 TC 149 Z9 152 U1 3 U2 35 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD SEP PY 1999 VL 77 IS 3 BP 1445 EP 1457 DI 10.1016/S0006-3495(99)76992-4 PG 13 WC Biophysics SC Biophysics GA 232AL UT WOS:000082343500023 PM 10465755 ER PT J AU Vasiliskov, AV Timofeev, EN Surzhikov, SA Drobyshev, AL Shick, VV Mirzabekov, AD AF Vasiliskov, AV Timofeev, EN Surzhikov, SA Drobyshev, AL Shick, VV Mirzabekov, AD TI Fabrication of microarray of gel-immobilized compounds on a chip by copolymerization SO BIOTECHNIQUES LA English DT Article ID DENSITY OLIGONUCLEOTIDE ARRAYS; DNA ARRAYS; HYBRIDIZATION; MICROCHIPS; IDENTIFICATION; GENOME; ELECTROPHORESIS; MUTATIONS AB The manufacturing of microchips containing oligonucleotides and proteins immobilized within gel pads, ranging in size from 10 x 10 to 100 X 100 mu m, is described. The microchips are produced by photo- or persulfate-induced copolymerization of unsaturated derivatives of biomolecules with acrylamide-bisacrylamide mixture. Oligonucleotides containing 5'-allyl or 5'-butene-diol units were synthesized using standard phosphoramidite chemistry. Acryloyl residues were attached to a protein by a two-step procedure. Photopolymerization was induced by illumination of the monomer solution containing initiator with UV light through the mask. The mask was applied directly over the monomer solution or projected through a microscope. Alternatively copolymerization was carried out in drops of aqueous solution of monomers containing ammonium persulfate. Drops with different allyl-oligonucleotides were distributed on a glass slide, and the polymerization was induced by diffusion of N,N,N',N'-tetramethylethylenediamine (TEMED) from a hexane solution that covered the aqueous drops. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Russian Acad Sci, VA Engelhardt Mol Biol Inst, Moscow, Russia. Moscow Inst Phys & Technol, Dolgoprudny, Russia. RP Mirzabekov, AD (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 21 TC 64 Z9 73 U1 2 U2 9 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD SEP PY 1999 VL 27 IS 3 BP 592 EP + PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 233VR UT WOS:000082448300026 PM 10489618 ER PT J AU Wooley, R Ruth, M Glassner, D Sheehan, J AF Wooley, R Ruth, M Glassner, D Sheehan, J TI Process design and costing of bioethanol technology: A tool for determining the status and direction of research and development SO BIOTECHNOLOGY PROGRESS LA English DT Article ID ZYMOMONAS-MOBILIS; ETHANOL AB Bioethanol is a fuel-grade ethanol made from trees, grasses, and waste materials. It represents a sustainable substitute for gasoline in today's passenger cars. Modeling and design of processes for making bioethanol are critical tools used in the U.S. Department of Energy's bioethanol research and development program. We use such analysis to guide new directions for research and to help us understand the level at which and the time when bioethanol will achieve commercial success. This paper provides an update on our latest estimates for current and projected costs of bioethanol. These estimates are the result of very sophisticated modeling and costing efforts undertaken in the program over the past few years. Bioethanol could cost anywhere from $1.16 to $1.44 per gallon, depending on the technology and the availability of low cost feedstocks for conversion: to ethanol. While this cost range opens the door to fuel blending opportunities, in which ethanol can be used, for example, to improve the octane rating of gasoline, it is not currently competitive with gasoline as a bulk fuel. Research strategies and goals described in this paper have been translated into cost savings for ethanol. Our analysis of these goals shows that the cost of ethanol could drop by 40 cents per gallon over the next ten years by taking advantage of exciting new tools in biotechnology that will improve yield and performance in the conversion process. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Wooley, R (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 47 TC 213 Z9 225 U1 2 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD SEP-OCT PY 1999 VL 15 IS 5 BP 794 EP 803 DI 10.1021/bp990107u PG 10 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 242JF UT WOS:000082936200003 ER PT J AU Sheehan, J Himmel, M AF Sheehan, J Himmel, M TI Enzymes, energy, and the environment: A strategic perspective on the US Department of Energy's Research and Development Activities for Bioethanol SO BIOTECHNOLOGY PROGRESS LA English DT Review ID REESEI CELLOBIOHYDROLASE-I; CELLULOSE-BINDING DOMAIN; TRICHODERMA-REESEI; TALAROMYCES-EMERSONII; MOLECULAR EVOLUTION; CRYSTALLINE CELLULOSE; VITRO RECOMBINATION; COMPONENTS; SYNERGISM; SYSTEMS AB For well over one hundred years, researchers around the world have pursued ways to make ethanol from biomass such as wood, grasses, and waste materials. To distinguish it from ethanol made from starch and sugars in traditional agricultural crops, we refer to ethanol made from biomass as "bioethanol." The effort to develop bioethanol technology gained significant momentum in the late 1970s as a result of the energy crises that occurred in that decade. This article briefly reviews the broader history of bioethanol technology development. With this as a background, we focus our attention on the strategic thinking behind the U.S. Department of Energy's Bioethanol Program, which envisions remarkable advances in cellulase enzyme research and as the basis for significant future process cost reductions. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Himmel, M (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 108 TC 134 Z9 153 U1 2 U2 35 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD SEP-OCT PY 1999 VL 15 IS 5 BP 817 EP 827 DI 10.1021/bp990110d PG 11 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 242JF UT WOS:000082936200005 ER PT J AU Godbole, S Decker, SR Nieves, RA Adney, WS Vinzant, TB Baker, JO Thomas, SR Himmel, ME AF Godbole, S Decker, SR Nieves, RA Adney, WS Vinzant, TB Baker, JO Thomas, SR Himmel, ME TI Cloning and expression of Trichoderma reesei cellobiohydrolase I in Pichia pastoris SO BIOTECHNOLOGY PROGRESS LA English DT Article ID SACCHAROMYCES-CEREVISIAE; EFFICIENT SECRETION; CELLULASE AB Pichia pastoris was transformed with the Trichoderma reesei cbh1 gene, and the recombinant enzyme was purified and analyzed kinetically and by circular dichroism. The P. pastoris rCBH I was recognized by MoAb raised to T. reesei CBH I but was found in multiple molecular weight species on SDS-PAGE gels. Carbohydrate content determination and SDS-PAGE western analysis indicated that the recombinant protein was hyperglycosylated, although a species very similar in molecular weight to the T. reesei enzyme could be isolated chromatographically. The P. pastoris rCBH I also demonstrated activity toward soluble and insoluble substrates (i.e., pNPL and Sigmacell), although at a level significantly lower than the wild-type enzyme. More seriously, the yeast-expressed enzyme showed non-wild-type secondary structure by circular dichroism. We conclude that P. pastoris may not serve as an adequate host for the site-directed mutagenesis of T. reesei CBH I. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Himmel, ME (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 22 TC 37 Z9 41 U1 3 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD SEP-OCT PY 1999 VL 15 IS 5 BP 828 EP 833 DI 10.1021/bp9901116 PG 6 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 242JF UT WOS:000082936200006 PM 10514252 ER PT J AU Benzi, M Golub, GH AF Benzi, M Golub, GH TI Bounds for the entries of matrix functions with applications to preconditioning SO BIT LA English DT Article DE matrix functions; quadrature rules; Lanczos process; band matrices; exponential decay; preconditioned conjugate gradients ID CONJUGATE-GRADIENT METHOD; BAND MATRICES; INVERSE; QUADRATURE; MOMENTS; ERROR AB Let A be a symmetric matrix and let f be a smooth function defined on an interval containing the spectrum of A. Generalizing a well-known result of Demko, Moss and Smith on the decay of the inverse we show that when A is banded, the entries of f(A) are bounded in an exponentially decaying manner away from the main diagonal. Bounds obtained by representing the entries of f(A) in terms of Riemann-Stieltjes integrals and by approximating such integrals by Gaussian quadrature rules are also considered. Applications of these bounds to preconditioning are suggested and illustrated by a few numerical examples. C1 Univ Calif Los Alamos Natl Lab, Sci Comp Grp, Los Alamos, NM 87545 USA. Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA. NR 40 TC 56 Z9 57 U1 0 U2 4 PU SWETS ZEITLINGER PUBLISHERS PI LISSE PA P O BOX 825, 2160 SZ LISSE, NETHERLANDS SN 0006-3835 J9 BIT JI Bit PD SEP PY 1999 VL 39 IS 3 BP 417 EP 438 DI 10.1023/A:1022362401426 PG 22 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 231KV UT WOS:000082308900003 ER PT J AU Rho, JY Zioupos, P Currey, JD Pharr, GM AF Rho, JY Zioupos, P Currey, JD Pharr, GM TI Variations in the individual thick lamellar properties within osteons by nanoindentation SO BONE LA English DT Article DE elastic modulus; hardness; nanoindentation; osteons; lamellae of bone ID SENSING INDENTATION EXPERIMENTS; MECHANICAL-PROPERTIES; ELASTIC PROPERTIES; BONE; HARDNESS AB The nanoindentation method was used to examine variations in the individual thick lamellar properties within completed secondary osteons as a function of distance from the osteonal center (haversian canal). In general, there is a decline in both elastic modulus and hardness from the center of the osteon outward. Because some of the osteons may have a different general trend than others, an analysis of covariance was also carried out. The overall analysis was highly significant for both elastic modulus and hardness. Also, osteon number was significant as a factor, indicating that there was some difference in the overall thick lamellar properties of the different osteons, An unpaired t-test showed statistically significant differences (p = 0.0005 and 0.0004, respectively) between thick lamellar properties obtained from most of the inner two osteonal lamellae (E = 20.8 +/- 1.3 GPa and H = 0.65 +/- 0.06 GPa) and those from outermost two osteonal lamellae (E = 18.8 +/- 1.0 GPa and H = 0.55 +/- 0.05 GPa). In general, lamellar properties from near to the center of the osteon were greater than those from the outermost osteonal lamella. The mechanical properties of osteons are also significantly lower than those of the interstitial bone (p < 0.0001), The ratio (E-1/E-2) of the elastic moduli of the outermost osteonal lamella (E-1) (considered to be the soft part of the osteons) and that of interstitial bone (E-2) was approximately 0.7. These results may have important implications for the mechanical contribution of individual osteons to bone biomechanics. (C) 1999 by Elsevier Science Inc. All rights reserved. C1 Memphis State Univ, Dept Biomed Engn, Memphis, TN 38152 USA. Cranfield Univ, Dept Mat & Med Sci, Shrivenham, England. Univ York, Dept Biol, York, N Yorkshire, England. Univ Tennessee, Dept Mat Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Rho, JY (reprint author), Memphis State Univ, Dept Biomed Engn, Memphis, TN 38152 USA. OI ZIOUPOS, PETER/0000-0002-0123-2706 FU NIAMS NIH HHS [AR45297]; Wellcome Trust NR 29 TC 148 Z9 158 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 8756-3282 J9 BONE JI Bone PD SEP PY 1999 VL 25 IS 3 BP 295 EP 300 DI 10.1016/S8756-3282(99)00163-5 PG 6 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 234GR UT WOS:000082476600006 PM 10495133 ER PT J AU Nasstrom, DL Ermak, JS AF Nasstrom, DL Ermak, JS TI A homogeneous langevin equation model, part I: Simulation of particle trajectories in turbulence with a skewed velocity distribution SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE Langevin equation; Lagrangian stochastic model; convective boundary layer ID CONVECTIVE BOUNDARY-LAYER; RANDOM-WALK MODELS; DISPERSION MODELS; STOCHASTIC-MODELS; FLOWS; DIFFUSION; PDF AB A Lagrangian stochastic model for the time evolution of the velocity of a fluid particle is presented. This model is based on a one-dimensional generalized Langevin equation, and assumes the velocity probability distribution of the turbulent fluid is skewed and spatially homogeneous. This has been shown to be an effective approach to simulating vertical dispersion in the convective boundary layer. We use a form of the Langevin equation that has a linear (in velocity) deterministic acceleration and a random acceleration that is a non-Gaussian, skewed process. For the case of homogeneous fluid velocity statistics, this 'linear-skewed' Langevin equation can be integrated explicitly, resulting in an efficient numerical simulation method. Model simulations were tested using cases for which exact, analytic statistical properties of particle velocity are known. Results of these tests show that, for homogeneous turbulence, a linear-skewed Langevin equation model can overcome the difficulties encountered in applying a Langevin equation with a skewed random acceleration. The linear-skewed Langevin equation model results are compared to results of a 'nonlinear-Gaussian' Langevin equation model, and show that the linear-skewed model is significantly more efficient. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Nasstrom, DL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mail Stop L-103,POB 808, Livermore, CA 94551 USA. NR 35 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD SEP PY 1999 VL 92 IS 3 BP 343 EP 369 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 239NV UT WOS:000082776200001 ER PT J AU Nasstrom, JS Ermak, DL AF Nasstrom, JS Ermak, DL TI A homogeneous Langevin equation model, part II: Simulation of dispersion in the convective boundary layer SO BOUNDARY-LAYER METEOROLOGY LA English DT Article DE Lagrangian stochastic dispersion model; convective boundary layer; Langevin equation; reflection boundary conditions ID STOCHASTIC-MODELS; LABORATORY MODEL; COHERENT EDDIES; MIXED-LAYER; TURBULENCE; DIFFUSION; VELOCITY; TRAJECTORIES AB We present a Lagrangian stochastic model of vertical dispersion in the convective boundary layer (CBL). This model is based on a generalized Langevin equation that uses the simplifying assumption that the skewed vertical velocity probability distribution is spatially homogeneous. This approach has been shown to account for two key properties of CBL turbulence associated with large-scale coherent turbulent structures: skewed vertical velocity distributions and long velocity correlation time. A 'linear-skewed' form of the generalized Langevin equation is used, which has a linear (in velocity) deterministic acceleration and a skewed random acceleration. 'Reflection' boundary conditions for selecting a new velocity for a particle that encounters a boundary were investigated, including alternatives to the standard assumption that the magnitudes of the particle incident and reflected velocities are positively correlated. Model simulations were tested using cases for which exact, analytic statistical properties of particle velocity and position are known, i.e., well-mixed spatial and velocity distributions. Simulations of laboratory experiments of CBL dispersion show that (1) the homogeneous linear-skewed Langevin equation model (as well as an alternative 'nonlinear-Gaussian' Langevin equation model) can simulate the important aspects of dispersion in the CBL, and (2) a negatively-correlated-speed reflection boundary condition simulates the observed dispersion of material near the surface in the CBL significantly better than alternative reflection boundary conditions. The homogeneous linear-skewed Langevin equation model has the advantage that it is computationally more efficient than the homogeneous nonlinear-Gaussian Langevin equation model, and considerably more efficient than inhomogeneous Langevin equation models. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Nasstrom, JS (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,Mail Stop L-103, Livermore, CA 94551 USA. NR 36 TC 3 Z9 3 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD SEP PY 1999 VL 92 IS 3 BP 371 EP 405 DI 10.1023/A:1002084729558 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 239NV UT WOS:000082776200002 ER PT J AU Felton, JS Knize, MG Hatch, FT Tanga, MJ Colvin, ME AF Felton, JS Knize, MG Hatch, FT Tanga, MJ Colvin, ME TI Heterocyclic amine formation and the impact of structure on their mutagenicity SO CANCER LETTERS LA English DT Article; Proceedings Paper CT 7th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-06, 1998 CL NAGOYA, JAPAN DE heterocyclic amines; QSAR; model systems; imidazopyridine ID QUANTITATIVE STRUCTURE; AROMATIC-AMINES; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE PHIP; FOOD MUTAGENS; COOKED FOODS; CARCINOGENICITY; BEEF; 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE; COMPOUND; RATS AB The occurrence and formation of heterocyclic amines in foods is discussed in light of the consistent finding of a new class of imidazopyridines. In addition, a quantitative structure-activity relationship will be presented correlating the potency of these imidazopyridines to predicted chemical properties. Although no strong linear correlation is found between the potency and the chemical properties, a low dipole moment is found to be a qualitative predictor of high mutagenic potency. (C) 1999 Published by Elsevier Science Ireland Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. SRI Int, Menlo Park, CA 94025 USA. RP Felton, JS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Mailstop L-452, Livermore, CA 94551 USA. FU NCI NIH HHS [CA55861] NR 27 TC 27 Z9 29 U1 0 U2 9 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 SEP 1 PY 1999 VL 143 IS 2 BP 127 EP 134 DI 10.1016/S0304-3835(99)00141-X PG 8 WC Oncology SC Oncology GA 234QH UT WOS:000082495500007 PM 10503891 ER PT J AU Lang, NP Nowell, S Malfatti, MA Kulp, KS Knize, MG Davis, C Massengill, J Williams, S MacLeod, S Dingley, KH Felton, JS Turteltaub, KW AF Lang, NP Nowell, S Malfatti, MA Kulp, KS Knize, MG Davis, C Massengill, J Williams, S MacLeod, S Dingley, KH Felton, JS Turteltaub, KW TI In vivo human metabolism of [2-C-14]2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine (PhIP) SO CANCER LETTERS LA English DT Article; Proceedings Paper CT 7th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-06, 1998 CL NAGOYA, JAPAN DE 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine; metabolism; phenotype; CYP1A2; SULT1A1 ID HETEROCYCLIC AMINES; COLORECTAL-CANCER; AROMATIC-AMINES; ACTIVATION; COLON; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE; ACETYLTRANSFERASE; ARYLAMINES; CARCINOGEN; FOOD AB To better understand the interactions of the pathways of activation and detoxification on the metabolism of the putative carcinogen, PhIP, we administered a dose of 70-84 mu g [2-C-14] PhIP (17.5 mu Ci C-14) 48-72 h before scheduled colon surgery. Blood and urine collected for the next 48-72 h was evaluated by linear accelerator mass spectroscopy (AMS) and scintillation counting LC-MS to identify specific PhIP metabolites. The thermostable phenol sulfotransferase (SULT1A1) phenotype was correlated with the 4'-PhIP-SO4 levels in the urine at 0-4 h (R = 0.86, P = 0.059). The CYP1A2 activity had a negative correlation with PhIP serum levels at 1 h (R = 0.94, P = 0.06) and a positive correlation with urine N-OH-PhIP levels at 0-4 h (R = 0.85, P = 0.15). This low level radioisotope method of determining the influence of phenotype on metabolism will significantly improve our understanding of the interrelationships of these pathways and provide a critical foundation for the development of individual risk assessment. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved. C1 Little Rock VA Hosp, Surg Serv 112LR, Little Rock, AR 72205 USA. Univ Arkansas Med Sci, Arkansas Canc Res Ctr, Little Rock, AR 72205 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Lang, NP (reprint author), Little Rock VA Hosp, Surg Serv 112LR, 4300 W 7th, Little Rock, AR 72205 USA. FU NCI NIH HHS [CA55861, CA55751, CA58697] NR 13 TC 25 Z9 25 U1 0 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 SEP 1 PY 1999 VL 143 IS 2 BP 135 EP 138 DI 10.1016/S0304-3835(99)00142-1 PG 4 WC Oncology SC Oncology GA 234QH UT WOS:000082495500008 PM 10503892 ER PT J AU Turteltaub, KW Dingley, KH Curtis, KD Malfatti, MA Turesky, RJ Garner, RC Felton, JS Lang, NP AF Turteltaub, KW Dingley, KH Curtis, KD Malfatti, MA Turesky, RJ Garner, RC Felton, JS Lang, NP TI Macromolecular adduct formation and metabolism of heterocyclic amines in humans and rodents at low doses SO CANCER LETTERS LA English DT Article; Proceedings Paper CT 7th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-06, 1998 CL NAGOYA, JAPAN DE 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine; 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline; accelerator mass spectrometry; human; rodent; dosimetry ID BREAST-CANCER; MUTAGEN 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE PHIP; COLORECTAL-CANCER; COVALENT BINDING; FOOD MUTAGEN; RAT-LIVER; RISK; DNA; MEAT AB 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) are heterocyclic amines formed during the cooking of meat and fish. Both are genotoxic in a number of test systems and are carcinogenic in rats and mice. Human exposure to these compounds via dietary sources has been estimated to be under 1 mu g/kg body wt. per day, although most laboratory animal studies have been conducted at doses in excess of 10 mg/kg body wt. per day. We are using accelerator mass spectrometry (AMS), a tool for measuring isotopes with attomole sensitivity, to study the dosimetry of protein and DNA adduct formation by low doses of MeIQx and PhIP in rodents and comparing the adduct levels to those formed in humans. The results of these studies show: 1, protein and DNA adduct levels in rodents are dose-dependent; 2, adduct levels in human tissues and blood are generally greater than ill rodents administered equivalent doses; and 3, metabolite profiles differ substantially between humans and rodents for both MeIQx and PhIP, with more N-hydroxylation (bioactivation) and less ring oxidation (detoxification) in humans. These data suggest that rodent models do not accurately represent the human response to heterocyclic amine exposure. (C) 1999 Published by Elsevier Science Ireland Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Nestec Ltd, Nestle Res Ctr, CH-1000 Lausanne 26, Switzerland. Univ York, Jack Birch Unit Environm Carcinogenesis, York YO1 5DD, N Yorkshire, England. Univ Arkansas Med Sci, Little Rock, AR 72205 USA. RP Turteltaub, KW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. FU NCI NIH HHS [CA55861] NR 36 TC 63 Z9 64 U1 0 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 SEP 1 PY 1999 VL 143 IS 2 BP 149 EP 155 DI 10.1016/S0304-3835(99)00116-0 PG 7 WC Oncology SC Oncology GA 234QH UT WOS:000082495500011 PM 10503895 ER PT J AU Garner, RC Lightfoot, TJ Cupid, BC Russell, D Coxhead, JM Kutschera, W Priller, A Rom, W Steier, P Alexander, DJ Leveson, SH Dingley, KH Mauthe, RJ Turteltaub, KW AF Garner, RC Lightfoot, TJ Cupid, BC Russell, D Coxhead, JM Kutschera, W Priller, A Rom, W Steier, P Alexander, DJ Leveson, SH Dingley, KH Mauthe, RJ Turteltaub, KW TI Comparative biotransformation studies of MeIQx and PhIP in animal models and humans SO CANCER LETTERS LA English DT Article; Proceedings Paper CT 7th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-06, 1998 CL NAGOYA, JAPAN DE colorectal cancer; heterocyclic amine; DNA adduct; accelerator mass spectrometry ID 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE PHIP; FOOD; 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE; ACTIVATION; CARCINOGEN; CANCER; COLON; RISK; DNA; IDENTIFICATION AB MeIQx and PhIP are putative carcinogenic heterocyclic amines formed during the cooking of meat and fish. Using accelerator mass spectrometry, we have investigated the metabolism and macromolecule binding of C-14-labelled MeIQx and PhIP in human cancer patients compared to the rat. Following oral administration of MeIQx and PhIP, more DNA adducts were formed in human colon tissue compared with rats. Differences were also observed between rats and humans in the metabolite profile and urine excretion for these compounds. These results suggest humans metabolise heterocyclic amines differently to laboratory rodents and question their use as models of human risk. (C) 1999 Published by Elsevier Science Ireland Ltd. C1 Univ York, Dept Biol, JBUEC, York YO1 5YW, N Yorkshire, England. Univ Vienna, Inst Radiumforsch & Kernphys, Vienna Environm Res Accelerator, A-1090 Vienna, Austria. York Dist Hosp, York YO3 7HE, N Yorkshire, England. Univ Calif Lawrence Livermore Natl Lab, Mol Toxicol Grp, Livermore, CA 94550 USA. RP Garner, RC (reprint author), Univ York, Dept Biol, JBUEC, POB 373, York YO1 5YW, N Yorkshire, England. OI Priller, Alfred/0000-0002-5008-2089 FU PHS HHS [55861] NR 21 TC 32 Z9 34 U1 0 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 SEP 1 PY 1999 VL 143 IS 2 BP 161 EP 165 DI 10.1016/S0304-3835(99)00118-4 PG 5 WC Oncology SC Oncology GA 234QH UT WOS:000082495500013 PM 10503897 ER PT J AU Fornasiero, F Ulrich, J Prausnitz, JM AF Fornasiero, F Ulrich, J Prausnitz, JM TI Molecular thermodynamics of precipitation SO CHEMICAL ENGINEERING AND PROCESSING LA English DT Article DE van der Waals theory; phase diagram; protein precipitation ID LIQUID PHASE-SEPARATION; LENS PROTEIN SOLUTIONS; WATER SOLUTION; CRYSTALLIZATION; BEHAVIOR; SYSTEM; MODEL AB Using a simple theory for fluids and a simple theory for a solid, it is possible to construct a semi-quantitative corresponding-states phase diagram where a reduced temperature is plotted as a function of a reduced density. The reducing parameters are molecular size (sigma(3)) and molecular potential energy (epsilon/k(B)); the phase diagram includes both low-density and high-density fluid regions and the solid region. These calculations apply to a pure substance or, of more interest, to a solute dissolved in a continuous solvent. The qualitative nature of the phase diagram depends strongly on the range of attractive intermolecular forces as indicated by an exponential parameter n; when coordination number z = 8 and n is about 6, we obtain the usual phase diagram where the fluid-solid region lies to the right of the fluid-fluid coexistence curve. But when n is about 7 or 8, the fluid-solid region lies above the fluid-fluid coexistence curve. Applications are discussed for aqueous solutions of a colloid or a globular protein that may also contain a salt or a polymer to induce precipitation. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Prausnitz, JM (reprint author), Univ Calif Berkeley, Dept Chem Engn, Gilman Hall, Berkeley, CA 94720 USA. RI Fornasiero, Francesco/I-3802-2012 NR 30 TC 12 Z9 12 U1 1 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0255-2701 J9 CHEM ENG PROCESS JI Chem. Eng. Process. PD SEP PY 1999 VL 38 IS 4-6 BP 463 EP 475 DI 10.1016/S0255-2701(99)00043-4 PG 13 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 242AX UT WOS:000082917000018 ER PT J AU Li, KM Byun, J Gross, ML Zamzow, D Jankowiak, R Rogan, EG Cavalieri, EL AF Li, KM Byun, J Gross, ML Zamzow, D Jankowiak, R Rogan, EG Cavalieri, EL TI Synthesis and structure determination of the adducts formed by electrochemical oxidation of dibenzo[a,l]pyrene in the presence of adenine SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID TUMOR-INITIATING ACTIVITY; ONE-ELECTRON OXIDATION; RAT-LIVER MICROSOMES; MOUSE SKIN; AROMATIC HYDROCARBON; MAMMARY-GLAND; DNA-ADDUCTS; IN-VITRO; BENZOPYRENE; 7,12-DIMETHYLBENZANTHRACENE AB Because the radical cations of polycyclic aromatic hydrocarbons (PAH) are involved in tumor initiation, determination of the structures of biologically formed PAH-DNA adducts is important and relies on comparison of their properties with those of synthesized adducts. One of the possible sites of adduct formation is the N-3 position of Ade, but this depurinating adduct is not obtained by one-electron oxidation of dibenzo[a,l]pyrene (DB[a,l]P) in the presence of deoxyadenosine. Therefore, we turned to electrochemical oxidation of DB [a,l]P in the presence of Ade in dimethylformamide and produced the following adducts: DB [a,l]P-10-N1Ade (47%), DB[a,l]P-10-N3Ade (5%), DB[a,l]P-10-N7Ade (2%), and DB[a,l]P-10-N(6)Ade (6%). In Me2SO, this reaction afforded the same four adducts, but in slightly different yields: DB[a,l]P-10-N1Ade (44%), DB[a,l]P-10-N3Ade (9%), DB[a,l]P-10-N7Ade( 1%), and DB[a,l]P-10-N(6)Ade (3%). These adducts were purified by reverse-phase HPLC, and the subtle differences between the isomers were revealed by NMR, tandem mass spectrometry, and fluorescence line-narrowing spectroscopy. The relative yields of the N1Ade, N3Ade, and N7Ade adducts reflect the nucleophilicity and steric accessibility of these three nitrogen atoms in Ade. C1 Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. RP Cavalieri, EL (reprint author), Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. FU NCI NIH HHS [P01-CA49210, R01-CA49917, CA367271] NR 26 TC 28 Z9 28 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 1999 VL 12 IS 9 BP 749 EP 757 DI 10.1021/tx9801965 PG 9 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 237WB UT WOS:000082678600002 PM 10490495 ER PT J AU Jankowiak, R Lin, CH Zamzow, D Roberts, KP Li, KM Small, GJ AF Jankowiak, R Lin, CH Zamzow, D Roberts, KP Li, KM Small, GJ TI Spectral and conformational analysis of deoxyadenosine adducts derived from syn- and anti-dibenzo[a,l]pyrene diol epoxides: Fluorescence studies SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; POLYACRYLAMIDE-GEL ELECTROPHORESIS; BENZOPYRENE DNA-ADDUCTS; MOUSE SKIN; DIBENZOPYRENE; IDENTIFICATION; LINE; QUANTITATION; SPECTROSCOPY; DIOLEPOXIDE AB Low-temperature fluorescence spectra and results of conformational studies with trans-syn-, cis-syn-, trans-anti-, and cis-anti-dibenzo[a,l]pyrene diol epoxide (DB [a,l]PDE)-derived deoxyadenosine (dA) adducts are presented and compared with those previously obtained for the stereoisomeric DB[a,l]P tetrols [Jankowiak, R., et al. (1997) Chem. Res. Toxicol. 10, 677-686]. In contrast to DB[a,l]P tetrols, for which only tl ans isomers exhibited two conformers, all stereoisomeric dA adducts adopt two different conformations with either half-chair or half-boat structures for the cyclohexenyl ring, and an "open"- or "folded"-type configuration between dA and the DB[a,l]P moiety. The major conformations observed for trans-syn-, cis-syn-, and cis-anti-DB [a,l]PDE-14-N(6)dA could be assigned on the basis of the previous calculations for the DB[a,l]P tetrols. The major conformers of the trans-syn- and cis-syn-DB[a,l]PDE-14-N(6)dA adducts exist in conformations I and II, with their fluorescence origin bands at similar to 382 and similar to 389 nm, respectively. In conformation I, the cyclohexenyl ring adopts a half-boat structure with dA in a pseudoaxial position (an open configuration), whereas the cyclohexenyl ring in conformation II adopts a half-chair structure with dA in pseudoequatorial position (a folded configuration). The major conformation of cis-anti-DB [a,l] PDE-14-N(6)dA, with its origin band at similar to 389 nm, was also assigned as a folded-type configuration with a half-chair structure in the cyclohexenyl ring. Molecular mechanics and dynamical simulations were performed for interpretation of the low-temperature fluorescence spectra and H-1 NMR coupling constants observed for the trans-anti-DB [a,l] PDE-14-N(6)dA adduct. The major conformer of this adduct has a half-chair structure in the cyclohexenyl ring, but a deviation from planarity in the fjord region different from that of conformer II of cis-anti-DB [a,l] PDE -N(6)dA. This new structure is labeled as conformer II'. Its (0,0) fluorescence band is at 388.1 and 388.3 nm in ethanol and glyceror/water glasses, respectively, consistent with the folded-type configuration revealed by the calculations. The fluorescence line-narrowed spectra reveal that the trans-syn-, cis-syn-, trans-anti-, and cis-anti-DB [a,l] PDE-14-N(6)dA adducts can be distinguished. Thus, their spectra should prove useful for identification of DB [a,l] P-DNA adducts formed at low levels in biological samples. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Omaha, NE 68198 USA. RP Jankowiak, R (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. FU NCI NIH HHS [P0I CA49210-0] NR 33 TC 16 Z9 17 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 1999 VL 12 IS 9 BP 768 EP 777 DI 10.1021/tx980233s PG 10 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 237WB UT WOS:000082678600004 PM 10490497 ER PT J AU Li, KM George, M Gross, ML Lin, CH Jankowiak, R Small, GJ Seidel, A Kroth, H Rogan, EG Cavalieri, EL AF Li, KM George, M Gross, ML Lin, CH Jankowiak, R Small, GJ Seidel, A Kroth, H Rogan, EG Cavalieri, EL TI Structure elucidation of the adducts formed by fjord resell dibenzo[a,l]pyrene-11,12-dihydrodiol 13,14-epoxides with deoxyguanosine SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID POLYACRYLAMIDE-GEL ELECTROPHORESIS; DIOL EPOXIDE; DNA-ADDUCTS; MOUSE SKIN; IDENTIFICATION; BENZOPYRENE; QUANTITATION; DIOLEPOXIDE; LINE; OLIGONUCLEOTIDES AB (+/-)-anti-Dibenzo[a,l]pyrene-11, 12-dihydrodiol 13,14-epoxide ((+/-)-anti-DB[a,l]PDE) was reacted with deoxyguanosine (dG) in dimethylformamide at 100 degrees C for 30 min, and two sets of adducts were isolated: a mixture of(+/-)-anti-cis- & -trans-N(2)dG (43%) and a mixture of (+/-)-anti-cis- & -trans-N7Gua (45%). Both are mixtures of four stereoisomers that cannot be separated by HPLC. Similarly, (+/-)-syn-DB[a,l]PDE was reacted with dG under the same conditions, and (+/-)-syn-cis- & -trans-N(2)dG (38%) and (+/-)-syn-cis- & -trans-N7Gua (59%) were obtained. The structures of the adducts were determined by a combination of NMR and fast atom bombardment mass spectrometry. By reacting (-)-anti-DB[a,l]PDE or (+)-syn-DB[a,l]PDE with dG under the same conditions, however, optically pure N(2)dG and N7Gua isomers were obtained: (-)-anti-cis-N(2)dG (12%), (-)-anti-trans-N(2)dG (17%), (-)-anfi-trans-N7Gua (43%), (+)-syn-cis-N(2)dG (7%), (+)-syn-trans-N(2)dG (3%), (+)-syn-cis-N7Gua (36%), and (+)-syn-trans-N7Gua (22%). The structures of the optically pure adducts were assigned by NMR. syn- and anti-DB[a,l]PDE -N(2)dG adducts can be distinguished by fluorescence line-narrowing spectroscopy (FLNS). Moreover, distinction between cis- and trans-stereochemistry of the adducts is also straightforward by FLNS, because the FLN spectra for the four DB[a,l]PDE-N(2)dG adducts, anti-cis, anti-trans, syn-cis, and syn-trans, are spectroscopically unique. C1 Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Univ Mainz, Inst Toxicol, D-6500 Mainz, Germany. RP Cavalieri, EL (reprint author), Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. FU NCI NIH HHS [R01 CA49917, P01 CA49210, P30-CA36727] NR 23 TC 15 Z9 15 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 1999 VL 12 IS 9 BP 778 EP 788 DI 10.1021/tx980234k PG 11 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 237WB UT WOS:000082678600005 PM 10490498 ER PT J AU Devanesan, P Ariese, F Jankowiak, R Small, GJ Rogan, EG Cavalieri, EL AF Devanesan, P Ariese, F Jankowiak, R Small, GJ Rogan, EG Cavalieri, EL TI Preparation, isolation, and characterization of dibenzo [a,l] pyrene diol epoxide-deoxyribonucleoside monophosphate adducts by HPLC and fluorescence line-narrowing spectroscopy SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID TUMOR-INITIATING ACTIVITY; RAT MAMMARY-GLAND; MOUSE SKIN; AROMATIC-HYDROCARBONS; DIBENZOPYRENE; 7,12-DIMETHYLBENZANTHRACENE; IDENTIFICATION; BENZOPYRENE; DNA; CARCINOGENICITY AB Dibenzo[a,l]pyrene (DB[a,l]P) is the most potent carcinogenic polycyclic aromatic hydrocarbon that has been identified in the environment. Earlier studies in our laboratory indicated that more than 80% of the DB[a,l]P-DNA adducts formed in vitro were depurinating adducts and that most of the stable adducts were formed from diol epoxide intermediates. To complete the profile of both stable and depurinating adducts of DB[a,l]P, we have synthesized standard adducts by reacting 3'-dAMP or 3'-dGMP with either (+/-)-anti- or (+/-)-syn-dibenzo[a,l]pyrene 11,12-dihydrodiol 13,14-epoxide (DB[a,l]PDE). The adducts were separated by HPLC with an ion-pair column and were identified by fluorescence line-narrowing spectroscopy (FLNS), A total of six pairs of stereoisomers along with another stable DB[a,l]PDE-DNA adduct were successfully isolated and identified. Pairs of (+/-)-trans and (+/-)-cis isomers were expected to be formed from the reaction of anti-DB[a,l]PDE with either dAMP or dGMP. While we were able to identify two pairs of stereoisomeric (+/-)-syn-DB[a,l]PDE-dAMP (cis and trans) and two pairs of stereoisomeric (+/-)-anti-DB [a,l]PDE-dAMP (cis and tl ans) adducts, identification of all the stereoisomers of dGMP adducts proved to be impossible. A pair of (+/-)-syn-trans-DB[a,l]PDE-dGMP adducts, a pair of(+/-)-anti-cis-DB[a,l]PDE-dGMP adducts, and one syn-cis-DB[a,l]PDE-dGMP adduct were conclusively identified by FLNS. These standard adducts will be used to identify the stable DNA adducts formed by DB[a,l]P and DB[a,l]PDE in vitro and in vivo. C1 Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Cavalieri, EL (reprint author), Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. FU NCI NIH HHS [R01 CA49917, P01 CA49210, CA36727] NR 22 TC 21 Z9 21 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 1999 VL 12 IS 9 BP 789 EP 795 DI 10.1021/tx980202x PG 7 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 237WB UT WOS:000082678600006 PM 10490499 ER PT J AU Devanesan, P Ariese, F Jankowiak, R Small, GJ Rogan, EG Cavalieri, EL AF Devanesan, P Ariese, F Jankowiak, R Small, GJ Rogan, EG Cavalieri, EL TI A novel method for the isolation and identification of stable DNA adducts formed by dibenzo[a,l]pyrene and dibenzo[a,l]pyrene 11,12-dihydrodiol 13,14-epoxides in vitro SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID P-32 POSTLABELING ASSAY; IN-VITRO; FLUORESCENCE; HPLC; CARCINOGENESIS; SPECTROSCOPY; DIOLEPOXIDE; ACTIVATION AB Our laboratory previously reported the identification and quantification of depurinating DNA adducts of dibenzo[a,l]pyrene (DB[a,l]P) in vitro, which comprise about 84% of all the DNA adducts that are formed [Li, K.-M., et al. (1995) Biochemistry 34, 8043-8049]. To determine a complete adduct profile and identify both stable and depurinating DNA adducts, we have developed a relatively simple, nonradioactive method for the identification of stable DNA adducts by combining enzymatic digestion, HPLC, and fluorescence line-narrowing spectroscopy (FLNS) techniques. Calf thymus DNA, bound to either (+/-)-anti- or (+/-)-syn-DB[a,l]PDE or rat liver microsome-activated DB[a,l]P, was first digested to 3'-mononucleotides with micrococcal nuclease and spleen phosphodiesterase. The adducts were then separated by HPLC with an ion-pair column and identified by FLNS by using the spectra of standards for comparison. In reactions with (+/-)-anti-DB[a,l]PDE, three adducts, an anti-cis-DB[a,l]PDE-dGMP, an anti-trans-DB[a,l]PDE-dAMP, and an anti-cis-DB[a,l]PDE-dAMP, were identified by HPLC and FLNS. In reactions with (+/-)-syn-DB[a,l]PDE, a pair of syn-trans-DB[a,l]PDE-dGMP adducts as well as a syn-cis-DB[a,l]PDE-dGMP, a syn-cis-DB[a,l]PDE-dAMP, and a pair of syn-trans-DB[a,l]PDE-dAMP adducts were identified. From the digest of microsome-activated DB[a,l]P-bound DNA, a syn-tl ans-DB[a,l]PDE-dGMP, an anti-cis-DB[a,l]PDE-dGMP, a syn-trans-DB[a,l]PDE-dAMP, and a syn-cis-DB[a,l]PDE-dAMP adduct were identified. An anti-cis-DB[a,l]PDE-dAMP adduct was identified only by P-32-postlabeling. A total of five of the stable adducts formed by DB[a,l]P and nine of the stable adducts formed by DB[a,l]PDE in vitro have been identified. These adducts were also correlated to adduct spots in the P-32-postlabeling method by cochromatography with standards. Approximately 93% of the stable adducts formed in reactions with (+/-)-anti-DB[a,l]PDE, 90% of adducts with (+/-)-syn-DB[a,l]PDE, and 85% of adducts formed with microsome-activated DB[a,l]P have been identified as Gua or Ade adducts. Equal amounts of stable Gua and Ade adducts were observed in the microsome-catalyzed binding of DB[a,l]P to calf thymus DNA, while 1.4 times more Gua adducts than Ade adducts were obtained in reactions with (+/-)-anti- or (+/-)-syn-DB[a,l]PDE. C1 Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Cavalieri, EL (reprint author), Univ Nebraska, Med Ctr, Eppley Inst Res Canc & Allied Dis, Nebraska Med Ctr 986805, Omaha, NE 68198 USA. FU NCI NIH HHS [CA36727, P01 CA49210, R01 CA49917] NR 21 TC 15 Z9 17 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD SEP PY 1999 VL 12 IS 9 BP 796 EP 801 DI 10.1021/tx980203p PG 6 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 237WB UT WOS:000082678600007 PM 10490500 ER PT J AU Taylor, BR Kauzlarich, SM Delgado, GR Lee, HWH AF Taylor, BR Kauzlarich, SM Delgado, GR Lee, HWH TI Solution synthesis and characterization of quantum confined Ge nanoparticles SO CHEMISTRY OF MATERIALS LA English DT Article ID SIZED SEMICONDUCTOR CLUSTERS; CHEMICAL-VAPOR-DEPOSITION; POROUS SILICON; VISIBLE PHOTOLUMINESCENCE; OPTICAL-PROPERTIES; LOW-TEMPERATURE; SIO2 MATRICES; NANOCRYSTALS; GERMANIUM; LUMINESCENCE AB A solution synthesis of crystalline Ge nanoparticles (nc-Ge) is reported. The metathesis reaction of NaGe with excess GeCl4 in glyme solvents produces nc-Ge. Metathesis reactions between KGe and excess GeCl4 or GeCl2:(dioxane) in glyme and Mg2Ge and excess GeCl4 in diglyme and triglyme were also investigated. The surface of these nanoparticles is terminated with alkyl groups by reaction with alkyl Li and Grignard reagents. The alkyl-terminated crystalline Ge nanoparticles ((R) over cap-nc-Ge) were characterized by Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy, powder X-ray diffraction, UV-vis absorption spectroscopy, photoluminescence, and photoluminescence excitation spectroscopy. The optical properties of (R) over cap-nc-Ge made by this method agree with predictions from quantum confinement models. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kauzlarich, SM (reprint author), Univ Calif Davis, Dept Chem, 1 Shields Ave, Davis, CA 95616 USA. NR 57 TC 98 Z9 99 U1 2 U2 35 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 SEP PY 1999 VL 11 IS 9 BP 2493 EP 2500 DI 10.1021/cm990203q PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 238JG UT WOS:000082706700035 ER PT J AU Harlow, RL Herron, N Li, ZG Vogt, T Solovyov, L Kirik, S AF Harlow, RL Herron, N Li, ZG Vogt, T Solovyov, L Kirik, S TI The DuPont powder challenge: The crystal structure of [C5NH6][Al3F10] - A cautionary tale SO CHEMISTRY OF MATERIALS LA English DT Article AB A compound previously reported as HAlF4 has been shown to be [pyridinium][Al3F10]. The structure of this phase was solved and refined using a combination of synchrotron X-ray and neutron powder diffraction techniques in association with a number of other analytical techniques. The structure consists of [Al3F10](n)(-) sheets containing both corner-sharing (common) and edge-sharing (unusual) AlF6 octahedra. The sheets are separated by pyridinium cations oriented perpendicular to the sheets. The final crystallographic data are as follows: monoclinic, space group C2/m, a = 8.2706(3), b = 6.1.998(3), c = 10.525(1) Angstrom, beta = 100.38(1)degrees, V = 525.0(1) Angstrom(3), and Z =2,This compound appears to be another example of a layered "clay-like" aluminum fluoride. C1 Dupont Co, Dept Cent Res & Dev, Wilmington, DE 19880 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Russian Acad Sci, Inst Chem & Chem Engn, Krasnoyarsk, Russia. RP Herron, N (reprint author), Dupont Co, Dept Cent Res & Dev, Wilmington, DE 19880 USA. RI Vogt, Thomas /A-1562-2011; Solovyov, Leonid/B-7246-2008 OI Vogt, Thomas /0000-0002-4731-2787; Solovyov, Leonid/0000-0002-3905-3252 NR 7 TC 22 Z9 22 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP PY 1999 VL 11 IS 9 BP 2562 EP 2567 DI 10.1021/cm990273x PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 238JG UT WOS:000082706700045 ER PT J AU Telengator, AM Margolis, SB Williams, FA AF Telengator, AM Margolis, SB Williams, FA TI Ignition analysis of a porous energetic material: II. Ignition at a closed heated end SO COMBUSTION THEORY AND MODELLING LA English DT Article ID CONSTANT TEMPERATURE BOUNDARY; 2-PHASE FLOW; DEFLAGRATION; FLUX AB A continuation of an ignition analysis for porous energetic materials subjected to a constant energy flux is presented. In the first part (I), the analysis was developed for the case of an open-end, semi-infinite material such that gas flow, generated by thermal expansion, was directed out of the porous solid, thereby removing energy from the system. In the present study, the case of a closed end is considered, and thus the thermally induced gas flow is now directed into the solid. In these studies, an asymptotic perturbation analysis, based on the smallness of the gas-to-solid density ratio and the largeness of the activation energy, is utilized to describe the inert and transition stages leading to thermal runaway. In both cases it is found that the effects of porosity provide a leading-order reduction in the time to ignition relative to that for the non-porous problem, arising from the reduced amount of solid material that must be heated and the difference in thermal conductivities of the solid and gaseous phases. A correction to the leading-order ignition-delay time, however, is provided by the convective flow of gas through the solid, and the sign of this correction is shown to depend on the direction of the gas flow. Thus, gas flowing out of an open-end solid was shown previously to give a positive correction to the leading-order time to ignition. Here, however, it is demonstrated that when the flow of gas is directed into the porous solid, the relative transport effects associated with the gas flow serve to preheat the material, resulting in a negative correction and hence a decrease in the ignition-delay time. C1 Univ Calif San Diego, Dept Appl Mech & Engn Sci, La Jolla, CA 92093 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Telengator, AM (reprint author), Univ Calif San Diego, Dept Appl Mech & Engn Sci, La Jolla, CA 92093 USA. NR 14 TC 3 Z9 3 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD SEP PY 1999 VL 3 IS 3 BP 433 EP 445 DI 10.1088/1364-7830/3/3/301 PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 242RD UT WOS:000082954700001 ER PT J AU Bastea, S Burkov, A Moukarzel, C Duxbury, PM AF Bastea, S Burkov, A Moukarzel, C Duxbury, PM TI Combinatorial optimization methods in disordered systems SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT Europhysics Conference on Computational Physics (CCP 98) CY SEP 02-05, 1998 CL GRANADA, SPAIN SP European Phys Soc, Computat Phys Grp, Univ Granada, Inst Carlos Theoret & Computat Phys, Int Union PUre & Appl Phys, Amer Phys Soc, EPS, E W Task Force, Consejeria Educ Ciencia, Granada Mayor Off, Spanish Minist Educ & Culture, UK Inst Phys, Apple Comp Inc ID GENERIC RIGIDITY PERCOLATION; RANDOM-FIELD SYSTEMS; GROUND-STATE; ZERO-TEMPERATURE; ISING SYSTEMS; MODEL; NETWORKS AB We give an overview of the applications of methods from combinatorial optimization to problems in disordered systems. The optimization methods are efficient, for example it is possible to find the ground stare of a random field Ising magnet containing one million sites in a couple of minutes on a high end workstation. Combinatorial algorithms for rigidity percolation and minimal energy domain walls in random exchange magnets are even more efficient, (C) 1999 Elsevier Science B.V. All rights reserved. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Michigan State Univ, Ctr Fundamental Mat Res, E Lansing, MI 48824 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Fed Fluminense, Inst Fis, BR-24210340 Niteroi, RJ, Brazil. RP Bastea, S (reprint author), Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. NR 32 TC 2 Z9 2 U1 0 U2 0 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 SEP-OCT PY 1999 VL 121 SI SI BP 199 EP 205 DI 10.1016/S0010-4655(99)00313-6 PG 7 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 263LP UT WOS:000084126400049 ER PT J AU Bastea, S AF Bastea, S TI Phase segregation via Vlasov-Boltzmann particle dynamics SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT Europhysics Conference on Computational Physics (CCP 98) CY SEP 02-05, 1998 CL GRANADA, SPAIN SP European Phys Soc, Computat Phys Grp, Univ Granada, Inst Carlos Theoret & Computat Phys, Int Union PUre & Appl Phys, Amer Phys Soc, EPS, E W Task Force, Consejeria Educ Ciencia, Granada Mayor Off, Spanish Minist Educ & Culture, UK Inst Phys, Apple Comp Inc ID SPINODAL DECOMPOSITION; BINARY-MIXTURES AB We introduce a mesoscopic model of phase segregation in binary fluids based on the Vlasov-Boltzmann equations and a particle dynamics computational scheme that is consistent with these equations. The numerical method is a combination of DSMC stochastic dynamics for the short range collisions and PIC deterministic evolution for the smooth long range interactions which allows the simulation of systems with millions of particles. This approach allows a detailed study of phase segregation kinetics in binary fluids and is very efficient even in the presence of externally imposed fields or hydrodynamical Rows. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bastea, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-415,7000 E Ave, Livermore, CA 94550 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 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 SEP-OCT PY 1999 VL 121 SI SI BP 270 EP 273 DI 10.1016/S0010-4655(99)00329-X PG 4 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 263LP UT WOS:000084126400065 ER PT J AU Pederiva, F Kalos, MH AF Pederiva, F Kalos, MH TI Fermion Monte Carlo SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT Europhysics Conference on Computational Physics (CCP 98) CY SEP 02-05, 1998 CL GRANADA, SPAIN SP European Phys Soc, Computat Phys Grp, Univ Granada, Inst Carlos Theoret & Computat Phys, Int Union PUre & Appl Phys, Amer Phys Soc, EPS, E W Task Force, Consejeria Educ Ciencia, Granada Mayor Off, Spanish Minist Educ & Culture, UK Inst Phys, Apple Comp Inc AB We review the fundamental challenge of fermion Monte Carlo for continuous systems, the "sign problem". We seek that eigenfunction of the many-body Schrodinger equation that is antisymmetric under interchange of the coordinates of pairs of particles. We describe methods that depend upon the use of correlated dynamics for pairs of correlated walkers that carry opposite signs. There is an algorithmic symmetry between such walkers that must be broken to create a method that is both exact and as effective as for symmetric functions. In our new method, it is broken by using different "guiding" functions for walkers of opposite signs, and a geometric correlation between steps of their walks. With a specific process of cancellation of the walkers. overlaps with antisymmetric test functions are preserved. Finally, we describe the progress in treating free-fermion systems and a fermion fluid with 14 He-3 atoms. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Cornell Univ, Ctr Theory & Simulat Sci & Engn, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Pederiva, F (reprint author), Cornell Univ, Ctr Theory & Simulat Sci & Engn, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA. NR 8 TC 3 Z9 3 U1 0 U2 1 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 SEP-OCT PY 1999 VL 121 SI SI BP 440 EP 445 DI 10.1016/S0010-4655(99)00378-1 PG 6 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 263LP UT WOS:000084126400109 ER PT J AU Trebin, HR Mikulla, R Stadler, J Schaaf, G Gumbsch, P AF Trebin, HR Mikulla, R Stadler, J Schaaf, G Gumbsch, P TI Molecular dynamics simulations of crack propagation in quasicrystals SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT Europhysics Conference on Computational Physics (CCP 98) CY SEP 02-05, 1998 CL GRANADA, SPAIN SP European Phys Soc, Computat Phys Grp, Univ Granada, Inst Carlos Theoret & Computat Phys, Int Union PUre & Appl Phys, Amer Phys Soc, EPS, E W Task Force, Consejeria Educ Ciencia, Granada Mayor Off, Spanish Minist Educ & Culture, UK Inst Phys, Apple Comp Inc AB The mechanism of plastic deformation in quasicrystals is dislocation motion, Dislocations leave in their wake a phason wall where the structure is weakened. Cracks emit dislocations and follow the phason wall. These processes are revealed by large scale molecular dynamics simulations employing the package IMD. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Stuttgart, Inst Theoret & Angew Phys, D-70550 Stuttgart, Germany. Univ Calif Los Alamos Natl Lab, Div Appl Theoret & Computat Phys, Los Alamos, NM 87544 USA. Max Planck Inst Met Forsch, D-70174 Stuttgart, Germany. RP Trebin, HR (reprint author), Univ Stuttgart, Inst Theoret & Angew Phys, D-70550 Stuttgart, Germany. RI Gumbsch, Peter/E-5879-2012 OI Gumbsch, Peter/0000-0001-7995-228X NR 3 TC 3 Z9 3 U1 1 U2 3 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 SEP-OCT PY 1999 VL 121 SI SI BP 536 EP 539 DI 10.1016/S0010-4655(99)00400-2 PG 4 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 263LP UT WOS:000084126400131 ER PT J AU Wilson, LJ Cagle, DW Thrash, TP Kennel, SJ Mirzadeh, S Alford, JM Ehrhardt, GJ AF Wilson, LJ Cagle, DW Thrash, TP Kennel, SJ Mirzadeh, S Alford, JM Ehrhardt, GJ TI Metallofullerene drug design SO COORDINATION CHEMISTRY REVIEWS LA English DT Article; Proceedings Paper CT 33rd International Conference on Coordination Chemistry CY AUG 30-SEP 04, 1998 CL FLORENCE, ITALY DE contrast agents; endohedral metallofullerenes; fullerene biodistribution; metallofullerols; nuclear medicine ID BONE TARGETED DRUGS; HYDROXYAPATITE AFFINITY; CONTRAST AGENTS; FULLERENE; C-60; RATS; ACTIVATION; TOXICITY; MODEL; ACID AB Endohedral lanthanide metallofullerenes are new molecules that may have useful medicinal properties. In particular, endohedral holmium metallofullerenes have been utilized in a model metallofullerene radiotracer study. The Ho-165 metallofullerenes were chemically functionalized to impart water solubility and then neutron activated to Ho-166 in order to determine their biodistribution and metabolism properties. The results have been evaluated for potential applications of lanthanide metallofullerenes as new diagnostic or therapeutic radiopharmaceuticals, Use of metallofullerenes in conventional diagnostic radiology (MRI contrast and X-ray imaging agents) has also been considered. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Rice Univ, Dept Chem, Houston, TX 77251 USA. Rice Univ, Ctr Nanoscale Sci & Technol, Houston, TX 77251 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. TDA Res Inc, Wheat Ridge, CO 80033 USA. Univ Missouri, Res Reactor Facil, Columbia, MO 65211 USA. RP Rice Univ, Dept Chem, POB 1892,MS-60, Houston, TX 77251 USA. EM durango@ruf.rice.edu NR 36 TC 108 Z9 109 U1 0 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0010-8545 EI 1873-3840 J9 COORDIN CHEM REV JI Coord. Chem. Rev. PD SEP PY 1999 VL 190 BP 199 EP 207 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 245ZH UT WOS:000083138300013 ER PT J AU Schlueter, JA Geiser, U Kini, AM Wang, HH Williams, JM Naumann, D Roy, T Hoge, B Eujen, R AF Schlueter, JA Geiser, U Kini, AM Wang, HH Williams, JM Naumann, D Roy, T Hoge, B Eujen, R TI Trifluoromethylmetallate anions as components of molecular charge transfer salts and superconductors SO COORDINATION CHEMISTRY REVIEWS LA English DT Article; Proceedings Paper CT 33rd International Conference on Coordination Chemistry CY AUG 30-SEP 04, 1998 CL FLORENCE, ITALY DE organic superconductor; tetrakis(trifluoromethyl)metallate anions ID PRESSURE ORGANIC SUPERCONDUCTOR; ELECTRON-DONOR MOLECULE; AMBIENT-PRESSURE; BEDT-TTF; ORGANOMETALLIC ANION; PHYSICAL-PROPERTIES; DI<3,4-3',4'-BIS(ETHYLENEDITHIO)-2,2',5,5'-TETRATHIAFULVALENIUM> DICHLOROCUPRATE; ESR CHARACTERIZATION; SOLVENT REPLACEMENT; CRYSTAL-STRUCTURES AB Whereas polymeric and common inorganic anions frequently deprive the synthetic chemist of a chance to modify a charge transfer salt"s structure through anion alterations, discrete organometallic anions provide a vast opportunity to probe the structure/property correlations of a material through rational synthetic methods. We have recently undertaken a research effort aimed at the crystallization of conducting charge transfer salts which possess modifiable, organometallic anions as the charge compensating entities. This research has been richly rewarded with the discovery of a new family of bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF or ET) based molecular superconductors. Herein is presented a summary of over 20 kappa(ET)(2)M(CF3)(4)(1,1,2-trihaloethane) (M = Cu, Ag, Au) superconducting salts. Three new related salts are also reported: (ET)(2)[trans-Ag(CF3)(2)(CN)(2)], kappa(L)(BEDT-TSF)(2)Ag(CF3)(4)(TCE), and kappa(L)(ET)(2)Ag(CF3)(3)Cl(TCE). (C) 1999 Elsevier Science S.A. AU rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Cologne, Inst Anorgan Chem, D-50939 Cologne, Germany. Berg Univ Gesamthsch Wuppertal, Fachbereich 9, D-42097 Wuppertal, Germany. RP Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM jaschlueter@anl.gov RI Hoge, Berthold/A-4051-2015; Kini, Aravinda/F-4467-2012 NR 80 TC 26 Z9 27 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0010-8545 EI 1873-3840 J9 COORDIN CHEM REV JI Coord. Chem. Rev. PD SEP PY 1999 VL 190 BP 781 EP 810 DI 10.1016/S0010-8545(99)00121-6 PG 30 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 245ZH UT WOS:000083138300042 ER PT J AU Buranda, T Lopez, GP Keij, J Harris, R Sklar, LA AF Buranda, T Lopez, GP Keij, J Harris, R Sklar, LA TI Peptides, antibodies, and. FRET on beads in flow cytometry: A model system using fluoresceinated and biotinylated beta-endorphin SO CYTOMETRY LA English DT Article DE flow cytometry; fluorescence; energy transfer; quenching; biosensors ID ISOTHERMAL TITRATION CALORIMETRY; RESONANCE ENERGY-TRANSFER; REAL-TIME ANALYSIS; FLOWMETRIX(TM) SYSTEM; LIGAND-BINDING; AVIDIN; STREPTAVIDIN; LIFETIME; LIBRARY; PROTEIN AB Background: Particulate surfaces such as beds are routinely used as platforms for molecular assembly for fundamental and practical applications in flow cytometry. Molecular assembly is transduced as the direct analysis of fluorescence, or as a result of fluorescence resonance energy transfer. Binding of fluorescent ligands to beads sometimes alters their emission yield relative to the unbound ligands. Characterizing the physical basis of factors that regulate the fluorescence yield of bound fluorophores (on beads) is a necessary step toward their rational use as mediators of numerous fluorescence based applications. Methods: We have examined the binding between two biotinylated and fluoresceinated beta-endorphin peptides and commercial streptavidin beads using flow cytometric analysis. We have analyzed the assembly between a specific monoclonal antibody and an endorphin. peptide in solution using resonance energy transfer and compared the results on beads in flow cytometry using steady-state and time-resolved fluorescence. Results;: We have defined conditions for binding biotinylated and fluoresceinated endorphin peptides to beads. These measurements suggest that the peptide structure can influence both the intensity of fluorescence and the mode of peptide binding on the bead surface. We have defined conditions for binding antibody to the bead using biotinylated protein A. We compared and contrasted the interactions between the fluoresceinated endorphin peptide and the rhodamine- labeled antibody. In solution rye measure a K-d of <38 nM by resonance energy transfer and on beads 22 nM. Discussion: Some issues important to the modular assembly of a fluorescence resonance energy transfer (FRET) based sensing scheme have been resolved. The affinity of peptides used herein is a function of their solubility in water, and the emission intensity of the bound species depends on the separation distance between the fluorescein and the biotin moiety. This is due to the quasi-specific quenching interaction between the fluorescein and a proximal binding pocket of streptavidin. Detection of antibodies in solution and on beads either by FRET or capture of fluorescent ligands by dark antibodies subsequently enables the determination of K-d values, which indicate agreement between solution and flow cytometric determinations. (C) 1999 Wiley-Liss, Inc. C1 Univ New Mexico, Ctr Canc, Sch Med, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Cytometry, Sch Med, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM USA. Commonwealth Biotechnol Inc, Richmond, VA USA. RP Buranda, T (reprint author), Univ New Mexico, Ctr Canc, Sch Med, Albuquerque, NM 87131 USA. FU NCRR NIH HHS [RR-01315] NR 37 TC 19 Z9 20 U1 0 U2 8 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-4763 J9 CYTOMETRY JI Cytometry PD SEP 1 PY 1999 VL 37 IS 1 BP 21 EP 31 DI 10.1002/(SICI)1097-0320(19990901)37:1<21::AID-CYTO3>3.0.CO;2-G PG 11 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 229CD UT WOS:000082175200003 PM 10451503 ER PT J AU Lebed, RF AF Lebed, RF TI Phenomenology of large N-c QCD SO CZECHOSLOVAK JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 11th Indian-Summer School on Intermediate Energy Physics - Mesons and Light Nuclei CY SEP 07-11, 1998 CL PRAGUE, CZECH REPUBLIC ID BARYON MAGNETIC-MOMENTS; 1/N-C EXPANSION; QUARK-MODEL; SYMMETRY-BREAKING; 1/N(C) EXPANSION; MASS SPLITTINGS; CURRENT-ALGEBRA; SKYRME MODEL; L=1 BARYONS; DECAYS AB These lectures are designed to introduce the methods and results of large N-c QCD in a presentation intended for nuclear and particle physicists alike. Beginning with definitions and motivations of the approach, we demonstrate that all quark and gluon Feynman diagrams are organized into classes based on powers of 1/N-c. We then show that this result can be translated into definite statements about mesons and baryons containing arbitrary numbers of constituents. In the mesons, numerous well-known phenomenological properties follow as immediate consequences of simply counting powers of N-c, while for the baryons, quantitative large N-c analyses of masses and other properties are seen to agree with experiment, even when "large" N-c is see equal to its observed value of 3. Large N-c reasoning is also used to explain some simple features of nuclear interactions. C1 Jefferson Lab, Newport News, VA 23606 USA. RP Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. EM lebed@jlab.org NR 53 TC 41 Z9 41 U1 0 U2 0 PU INST PHYSICS ACAD SCI CZECH REPUBLIC PI PRAGUE PA NA SLOVANCE 2, PRAGUE 182 21, CZECH REPUBLIC SN 0011-4626 J9 CZECH J PHYS JI Czech. J. Phys. PD SEP PY 1999 VL 49 IS 9 BP 1273 EP 1306 DI 10.1023/A:1022820227262 PG 34 WC Physics, Multidisciplinary SC Physics GA 239GN UT WOS:000082760600003 ER PT J AU Simpson, EH Johnson, DK Hunsicker, P Suffolk, R Jordan, SA Jackson, IJ AF Simpson, EH Johnson, DK Hunsicker, P Suffolk, R Jordan, SA Jackson, IJ TI The mouse Cer1 (Cerberus related or homologue) gene is not required for anterior pattern formation SO DEVELOPMENTAL BIOLOGY LA English DT Article ID BROWN (B)-LOCUS REGION; MOLECULAR-GENETICS; SECRETED FACTOR; LOCUS TEST; EXPRESSION; CHROMOSOME-4; DEFECTS; OTX2; GASTRULATION; ORGANIZER AB Cer1 is the mouse homologue of the Xenopus Cerberus gene whose product is able to induce development of head structures during embryonic development. The Cer1 protein is a member of the cysteine knot superfamily and is expressed in anterior regions of the mouse gastrula. A segmental pattern of expression with nascent and newly formed somites is also seen. This suggests an additional role in development of the axial skeleton, musculature,: or -peripheral nervous system. Xenopus animal cap assays and mouse germ-layer explant recombination experiments indicate that the mouse protein can act as a patterning molecule for anterior development in Xenopus, including induction of Otx2 expression, and suggest it may have a similar role in mouse development. However, we present here genetic data that demonstrate that Cer1 is not necessary for anterior patterning, Otx2 expression, somite formation, or even normal mouse morphogenesis. (C) 1999 Academic Press. C1 Western Gen Hosp, Human Genet Unit, MRC, Edinburgh EH4 2XU, Midlothian, Scotland. Oak Ridge Natl Lab, Div Biol, Oak Ridge, TN 37831 USA. RP Jackson, IJ (reprint author), Western Gen Hosp, Human Genet Unit, MRC, Crewe Rd, Edinburgh EH4 2XU, Midlothian, Scotland. NR 28 TC 45 Z9 46 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0012-1606 J9 DEV BIOL JI Dev. Biol. PD SEP 1 PY 1999 VL 213 IS 1 BP 202 EP 206 DI 10.1006/dbio.1999.9372 PG 5 WC Developmental Biology SC Developmental Biology GA 233HR UT WOS:000082421900015 PM 10452857 ER PT J AU Kahn, JR Farmer, A AF Kahn, JR Farmer, A TI The double dividend, second-best worlds, and real-world environmental policy SO ECOLOGICAL ECONOMICS LA English DT Article ID TAXATION; TAXES; COST AB The recent series of papers by Bovemberg, Goulder, Parry and others argue that the double dividend is unlikely to exist because of second-best problems. They argue that the imposition of environmental tax in an economy already distorted by income taxes will further distort the economy by reducing incentives to supply labor. Our paper argues that this is not likely to be the case because of the restrictive assumptions made by these models, and because of the role of the environment as a factor of production. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Econ, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Kahn, JR (reprint author), Univ Tennessee, Dept Econ, 534 Stokely Management Ctr, Knoxville, TN 37996 USA. NR 18 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8009 J9 ECOL ECON JI Ecol. Econ. PD SEP PY 1999 VL 30 IS 3 BP 433 EP 439 DI 10.1016/S0921-8009(99)00005-1 PG 7 WC Ecology; Economics; Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology; Business & Economics GA 256TK UT WOS:000083741500007 ER PT J AU Reich, PB Ellsworth, DS Walters, MB Vose, JM Gresham, C Volin, JC Bowman, WD AF Reich, PB Ellsworth, DS Walters, MB Vose, JM Gresham, C Volin, JC Bowman, WD TI Generality of leaf trait relationships: A test across six biomes SO ECOLOGY LA English DT Article DE alpine; desert; leaf life span; leaf diffusive conductance; nitrogen; photosynthesis; scaling; specific leaf area; temperate forest; tropical forest ID PHOTOSYNTHESIS-NITROGEN RELATIONS; LIFE-SPAN; PLANT; LEAVES; MASS; ECOPHYSIOLOGY; DIFFUSION; DEFENSE; PIPER; AREA AB Convergence in interspecific leaf trait relationships across diverse taxonomic groups and biomes would have important evolutionary and ecological implications. Such convergence has been hypothesized to result from trade-offs that limit the combination of plant traits for any species. Here we address this issue by testing for biome differences in the slope and intercept of interspecific relationships among leaf traits: longevity, net photosynthetic capacity (A(max)), leaf diffusive conductance (G(s)), specific leaf area (SLA), and nitrogen (N) status, for more than 100 species in six distinct biomes of the Americas. The six biomes were: alpine tundra-subalpine forest ecotone, cold temperate forest-prairie ecotone, montane cool temperate forest, desert shrubland, subtropical forest, and tropical rain forest. Despite large differences in climate and evolutionary history, in all biomes mass-based leaf N (N-mass), SLA, G(s), and A(max) were positively related to one another and decreased with increasing leaf life span. The relationships between pairs of leaf traits exhibited similar slopes among biomes, suggesting a predictable set of scaling relationships key leaf morphological, chemical, and metabolic traits that are replicated globally among terrestrial ecosystems regardless of biome or vegetation type. However, the intercept (i.e., the overall elevation of regression lines) of relationships between pairs of leaf traits usually differed among biomes. With increasing aridity across sites, species had greater A(max) for a given level of G(s) and lower SLA for any given leaf life span. Using principal components analysis, most variation among species was explained by an axis related to mass-based leaf traits (A(max) N, and SLA) while a second axis reflected climate, G(s), and other area-based leaf traits. C1 Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Michigan State Univ, Dept Forestry, E Lansing, MI 48824 USA. US Forest Serv, Coweeta Hydrol Lab, Otto, NC 28763 USA. Clemson Univ, Baruch Forest Inst, Georgetown, SC 29442 USA. Florida Atlantic Univ, Div Sci, Davie, FL 33314 USA. Univ Colorado, Mt Res Stn, Inst Arctic & Alpine Res, Boulder, CO 80309 USA. Univ Colorado, Dept Evolutionary Populat & Organism Biol, Boulder, CO 80309 USA. RP Reich, PB (reprint author), Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA. OI Ellsworth, David/0000-0002-9699-2272 NR 31 TC 703 Z9 797 U1 20 U2 246 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD SEP PY 1999 VL 80 IS 6 BP 1955 EP 1969 DI 10.1890/0012-9658(1999)080[1955:GOLTRA]2.0.CO;2 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 233CQ UT WOS:000082408300014 ER PT J AU Popovic, ND Johnson, DC AF Popovic, ND Johnson, DC TI Amperometric detection of biologically significant sulfur-containing compounds at Bi(V)-doped PbO2 film electrodes SO ELECTROANALYSIS LA English DT Article DE Bi-PbO2 film electrodes; cysteine; cystine; glutathione; methionine; HPLC; nonsurface fouling ID ANODIC OXYGEN-TRANSFER; LIQUID-CHROMATOGRAPHY; COBALT PHTHALOCYANINE; PBO2-FILM ELECTRODES; LEAD DIOXIDE; PLASMA AB Electrocatalytic oxidation of sulfur-containing amino acids and peptides at B(V)-doped beta-PbO2 film electrodes Bi-PbO2 was investigated in acidic media and tested for amperometric detection of representatives of these compounds following their separation as cationic species in a chromatographic column that exhibits both cation-exchange and reversed-phase properties. The Bi-PbO2 film electrodes permit detection with similar sensitivities for compounds that contain sulfhydryl, disulfide, thioether, and sulfoxide moieties. More specifically, detection limits at the pmol level were obtained for all analytes of interest The Bi-PbO2 electrodes were characterized by cyclic voltammetry, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). For the acidic media used in this study, only the nonsulfur containing amino acids tryptophane and tyrosine produced an anodic response; however, this occurred only at concentrations > 50 mu M. The linear dynamic range of response for methionine is demonstrated to be a sensitive function of applied potential. This observation is concluded to be consistent with a response mechanism by which a prerequisite is the anodic discharge of H2O to produce adsorbed OH radicals that are the immediate source of O-atoms transferred to the oxidation products. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Johnson, DC (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 14 TC 12 Z9 13 U1 1 U2 5 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD SEP PY 1999 VL 11 IS 13 BP 934 EP 939 DI 10.1002/(SICI)1521-4109(199909)11:13<934::AID-ELAN934>3.0.CO;2-F PG 6 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 236TC UT WOS:000082613700002 ER PT J AU Lee, SH Liu, P Tracy, CE Benson, DK AF Lee, SH Liu, P Tracy, CE Benson, DK TI All-solid-state rocking chair lithium battery on a flexible Al substrate SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID FILM AB All-solid-state thin film rocking chair lithium batteries were fabricated on 80 mu m thick, flexible aluminum foil substrates with the cell configuration of V2O5/Lipon/Li8V2O5 using sequential thin film deposition techniques. The total thickness of the device was 1.41 mu m. The battery cells incorporated thin film electrodes of highly lithiated vanadium oxide as an anode and vanadium oxide as a cathode. By controlling the lithium concentration in the lithiated vanadium oxide anode, an operating voltage ranging from 3 to 1 V was obtained. These cells with a 15 cm(2) active area delivered a discharge capacity of 50 mu Ah at room temperature and showed negligible capacity fade from the second cycle to more than 5800 cycles at a current density of 10 mu A/cm(2). (C) 1999 The Electrochemical Society. S1099-0062(99)04-024-9. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Lee, SH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Lee, Sehee/A-5989-2011; Liu, Ping/I-5615-2012 NR 7 TC 55 Z9 57 U1 4 U2 46 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD SEP PY 1999 VL 2 IS 9 BP 425 EP 427 DI 10.1149/1.1390859 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 216TX UT WOS:000081460900002 ER PT J AU Kostecki, R Song, X Kinoshita, K AF Kostecki, R Song, X Kinoshita, K TI Electrochemical analysis of carbon interdigitated microelectrodes SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID SITU CONDUCTIVITY MEASUREMENTS; MICROARRAY ELECTRODES; DIFFUSION LAYER; ARRAY; TITRATIONS; FILMS AB A procedure to fabricate carbon microelectrodes consisting of a patterned arrangement of interdigitated electrodes is described. Conventional semiconductor processing techniques involving photolithography to pattern photoresist layers on a Si wafer permit a convenient method to form the interdigitated structure. The photoresist is then converted to carbon by pyrolysis. The iodine-iodide redox reaction was used to demonstrate the performance of the carbon interdigitated electrode. (C) 1999 The Electrochemical Society. S1099-0062(99)04-071-7. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Kostecki, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 14 TC 27 Z9 28 U1 0 U2 10 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD SEP PY 1999 VL 2 IS 9 BP 465 EP 467 DI 10.1149/1.1390872 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 216TX UT WOS:000081460900015 ER PT J AU Dang, G Zhang, AP Cao, XA Ren, F Cho, H Pearton, SJ Shul, RJ Zhang, L Hickman, R Van Hove, JM AF Dang, G Zhang, AP Cao, XA Ren, F Cho, H Pearton, SJ Shul, RJ Zhang, L Hickman, R Van Hove, JM TI Electrical effects of Ar plasma damage on GaN diode rectifiers SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID GALLIUM NITRIDE; SILICON-CARBIDE; POWER DEVICES; TRANSISTORS AB Relatively small (less than or equal to 15%) decreases in reverse breakdown voltage of GaN diodes are observed after exposure to Ar inductively coupled plasmas over a wide range of conditions. However, the low-bias forward currents are increased by up to two orders of magnitude. Both ion energy and ion flux are important in determining the changes in electrical properties of the diodes. (C) 1999 The Electrochemical Society. S1099-0062(99)04-016-X. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. SVT Associates, Eden Prairie, MN 55344 USA. RP Dang, G (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. NR 19 TC 5 Z9 5 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD SEP PY 1999 VL 2 IS 9 BP 472 EP 474 DI 10.1149/1.1390874 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 216TX UT WOS:000081460900017 ER PT J AU Hagaman, EW Lee, SK AF Hagaman, EW Lee, SK TI Acid-catalyzed cross-linking reactions at benzylic sites in fluorene monomers, polymers, and lignin SO ENERGY & FUELS LA English DT Article ID SYNTHETIC METHODS; C-13 NMR; FLUORINATION; FLUORIDE AB The acid-catalyzed polymerization of benzylic alcohol and fluoride functionality in monomeric and polymeric fluorenes was investigated in both organic and aqueous reaction media. Polymeric products are consistent with the generation of benzylic cations that participate in electrophilic aromatic substitution reactions. Similar reactions occurred in a water-insoluble Kraft pine lignin, by treatment with aqueous acid. The acid treatment produced 1-2 cross-links/100 carbons in the biopolymer and markedly decreased its solubility in organic solvents. The nature of the reactions which produced the insoluble biopolymer are inferred from solid-state (CP/MAS) C-13 NMR spectra. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Hagaman, EW (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 14 TC 4 Z9 4 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1999 VL 13 IS 5 BP 1006 EP 1014 DI 10.1021/ef980269s PG 9 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 239EA UT WOS:000082754800008 ER PT J AU Cook, LL Gostomski, PA Apel, WA AF Cook, LL Gostomski, PA Apel, WA TI Biofiltration of asphalt emissions: Full-scale operation treating off-gases from polymer-modified asphalt production SO ENVIRONMENTAL PROGRESS LA English DT Article ID HYDROGEN-SULFIDE; BIOFILTER; REMOVAL; OXIDATION; KINETICS; AIR; H2S; BACTERIA; DESIGN; CH11 AB In response to complaints from nearby residents, a biofilter was designed installed, and tested for treating odors in one of three odorous emission streams from an asphalt plant pl producing polymer-modified asphalt. Hydrogen sulfide (H2S) was determined to be the most prevalent gaseous reduced sulfur compound and was detected in the emission stream only when polymer material war being added to raw asphalt. Emission scream H2S concentrations were quite variable, ranging from 16 to approximately 30, 000 ppm (v/v) and considered the likely compound contributing most to the plant's odor complaints. The biofilter was effective in controlling odor from the production process and removed an overall average of 65% of the H2S during polymer addition, and for H2S concentrations less than 400 ppmv, removal averaged 98%. These removal efficiencies reflect data from the biofilter operating at 2.5-minute empty bed residence time in 1996 and a 6.1-minute empty bed residence time in 1997. The biofilters bed became increasingly acidified during the plant's 1997 operating season producing a pH gradient through the bed ranging from a high of 6.6 to a low of 3.1. The bed medium moisture content remained constant at about 60% (wet weight basis), but changes were observed in the water potential: no correlation to performance was determined Changes in the microbial community reflected the bed acidification trend with acidophiles becoming generally more numerous in the bed's deeper portions and in the mid to late season when the bed was most acidified. Bed acidification did not impart the biofilter's H2S removal efficiency. Nearby residents were surveyed and roughly half of the respondents indicated that the odor conditions had improved, one-third felt odor conditions were unchanged ana the remaining 15% felt odor conditions were worse despite the fact that only one of three of the plant's odorous emission streams were treated by the biofilter. Plans are to implement biofiltration for odor control at all of the facility's emission points. C1 Dept Biotechnol, Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. Univ Canterbury, Dept Chem & Proc Engn, Christchurch 1, New Zealand. RP Cook, LL (reprint author), Dept Biotechnol, Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. NR 44 TC 6 Z9 6 U1 3 U2 5 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD FAL PY 1999 VL 18 IS 3 BP 178 EP 187 DI 10.1002/ep.670180314 PG 10 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 253PW UT WOS:000083565800008 ER PT J AU Jardine, PM Fendorf, SE Mayes, MA Larsen, IL Brooks, SC Bailey, WB AF Jardine, PM Fendorf, SE Mayes, MA Larsen, IL Brooks, SC Bailey, WB TI Fate and transport of hexavalent chromium in undisturbed heterogeneous soil SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID 2 CONTRASTING WATERSHEDS; NATURAL ORGANIC-MATTER; CHROMATE REDUCTION; FORESTED WATERSHEDS; GRAVEL AQUIFER; POROUS-MEDIA; ADSORPTION; IRON; SUBSURFACE; MECHANISMS AB The disposal of toxic metals [e.g., Cr(VI)] generated by the Department of Energy during the cold war era has historically involved shallow land burial in unconfined pits and trenches. The objectives of this study were to investigate the impact of coupled hydrologic and geochemical processes on the fate and transport of Cr(VI) in undisturbed soil cores obtained from a fractured, acidic inceptisol that are commonly used in the disposal of waste at the Oak Ridge National Laboratory. The mobility of Cr(VI) was significantly retarded relative to a nonreactive Br- tracer, and the mobility decreased with increased loading of the solid phase with natural organic matter (NOM). A significant portion of added Cr(VI) did not elute from the columns, and X-ray absorption near-edge structure (XANES) revealed that both Cr(VI) and Cr(III) resided on the sail mineral surfaces. The reduction of Cr(VI) to Cr(III) was dramatically more significant on soils with higher levels of surface-bound NOM. This indicated that NOM was serving as a suitable reductant during Cr(VI) transport even in the presence of potentially competing geochemical oxidation reactions involving Cr. The redox reaction was catalyzed by the presence of soil mineral surfaces, and the reduced product Cr(III) was immobilized as a tightly bound moiety. The effectiveness of surface-bound NOM to reduce toxic Cr(VI) to Cr(III) under acidic conditions has important implications regarding the design and implementation of in situ remedial strategies. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Stanford Univ, Dept Geog & Environm Sci, Stanford, CA 94305 USA. RP Jardine, PM (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Brooks, Scott/B-9439-2012 OI Brooks, Scott/0000-0002-8437-9788 NR 36 TC 137 Z9 142 U1 5 U2 65 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 SEP 1 PY 1999 VL 33 IS 17 BP 2939 EP 2944 DI 10.1021/es981211v PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 232JK UT WOS:000082367400035 ER PT J AU Brooks, SC Carroll, SL Jardine, PM AF Brooks, SC Carroll, SL Jardine, PM TI Sustained bacterial reduction of Co(III)EDTA(-) in the presence of competing geochemical oxidation during dynamic flow SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID METAL-NITRILOTRIACETATE COMPLEXES; IRON-REDUCING BACTERIA; CHELATOBACTER-HEINTZII; RADIONUCLIDE MIGRATION; SUBSURFACE MATERIALS; MICROBIAL REDUCTION; REACTIVE TRANSPORT; GRAIN COATINGS; ORGANIC-CARBON; ADSORPTION AB Radionuclides and metals can be mobilized by chelating agents typically present in low-level radioactive liquid wastes. [Co-60]EDTA in the form (60)Co(III)EDTA(-) represents a;highly stable [log K-Co(III)EDTA = 43.9] and mobile form of this radionuclide. By contrast, the reduced form of this metal-ligand complex, (60)Co(II)EDTA(2-), is much less stable [log K-Co(II)EDTA = 18.3] and less mobile. There is an increasing awareness that dissimilatory metal-reducing bacteria (DMRB) can be used to mediate redox transformations of metals and radionuclides whose stability and mobility are governed by their oxidation state. We conducted a series of column experiments to provide an improved understanding of Co(III)EDTA(-) reduction by the facultative anaerobe Shewanella alga BrY (BrY). Experiments were conducted under growth conditions using lactate as a carbon and energy source. We were able to demonstrate the sustained reduction of Co(III)EDTA- in column flow experiments with the desired result that a less stable, less mobile product was formed. The amount of reduction varied directly with the fluid residence time in the columns. In the presence of a suitable mineral sorbent [Fe(OH)(3)], Co-EDTA transport was delayed as a direct consequence of the bacterial reduction reaction. Even in the presence of a strong mineral oxidant (beta-MnO2) the net reduction of Co(III)EDTA- dominated the fate and transport of this species. The system was stable after flow interrupts, and metal-reducing activity could be revived after flushing the columns for 5 days with nutrient-free solution. Furthermore, we demonstrated that BrY could grow and carry out sustained reduction using geochemically derived Co(III)EDTA(-) as terminal electron acceptor. These results demonstrate that DMRB can he effective in the manipulation of redox-sensitive metals and radionuclides in a system characterized by the advective transport of solutes. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Brooks, SC (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,MS 6038, Oak Ridge, TN 37831 USA. RI Brooks, Scott/B-9439-2012 OI Brooks, Scott/0000-0002-8437-9788 NR 45 TC 18 Z9 19 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP 1 PY 1999 VL 33 IS 17 BP 3002 EP 3011 DI 10.1021/es990245f PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 232JK UT WOS:000082367400044 ER PT J AU Sample, BE Suter, GW Beauchamp, JJ Efroymson, RA AF Sample, BE Suter, GW Beauchamp, JJ Efroymson, RA TI Literature-derived bioaccumulation models for earthworms: Development and validation SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE ecological risk assessment; soil contamination; bioaccumulation; earthworms ID LUMBRICUS-TERRESTRIS; HEAVY-METALS; PB; ACCUMULATION; RUBELLUS; SOILS; CD AB Estimation of contaminant concentrations in earthworms is a critical component in many ecological risk assessments. Without site-specific data, literature-derived uptake factors or models are frequently used. Although considerable research has been conducted on contaminant transfer from soil to earthworms, most studies focus on only a single location. External validation of transfer models has not been performed. We developed a database of soil and tissue concentrations for nine inorganic and two organic chemicals. Only studies that presented total concentrations in depurated earthworms were included. Uptake factors and simple and multiple regression models of natural-log-transformed concentrations of each analyte in soil and earthworms were developed using data from 26 studies. These models were then applied to data from six additional studies. Estimated and observed earthworm concentrations were compared using nonparametric Wilcoxon signed-rank tests. Relative accuracy and quality of different estimation methods were evaluated by calculating the proportional deviation ([measured - estimate]/measured) of the estimate from the measured value. With the exception of Cr, significant, single-variable (e.g., soil concentration) regression models were fit for each analyte. Inclusion of soil Ca improved model fits for Cd and Pb. Soil pH only marginally improved model fits. The best general estimates of chemical concentrations in earthworms were generated by simple In-in regression models for As, Cd, Cu, Hg, Mn, Pb, Zn, and polychlorinated biphenyls. No method accurately estimated Cr or Ni in earthworms. Although multiple regression models including pH generated better estimates for a few analytes, in general, the predictive utility gained by incorporating environmental variables was marginal. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Sample, BE (reprint author), CH2M Hill, 2485 Natomas Pk Dr,Suite 600, Sacramento, CA 95833 USA. OI Efroymson, Rebecca/0000-0002-3190-880X NR 22 TC 57 Z9 59 U1 0 U2 13 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD SEP PY 1999 VL 18 IS 9 BP 2110 EP 2120 DI 10.1897/1551-5028(1999)018<2110:LDBMFE>2.3.CO;2 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 229NY UT WOS:000082201700032 ER PT J AU Sauerwein, W Hideghey, K Moss, R Busse, P Harling, O Zamenhoff, R Coderre, J Nakagawa, Y Pignol, JP AF Sauerwein, W Hideghey, K Moss, R Busse, P Harling, O Zamenhoff, R Coderre, J Nakagawa, Y Pignol, JP TI Past, present and future trends of boron neutron capture therapy (BNCT) SO EUROPEAN JOURNAL OF CANCER LA English DT Meeting Abstract C1 Univ Essen Gesamthsch, Essen, Germany. Harvard Univ, Cambridge, MA 02138 USA. MIT, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Natl Kagawa Childrens Hosp, Kagawa, Japan. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0959-8049 J9 EUR J CANCER JI Eur. J. Cancer PD SEP PY 1999 VL 35 SU 4 MA 339 BP S99 EP S99 DI 10.1016/S0959-8049(99)80773-4 PG 1 WC Oncology SC Oncology GA 244UC UT WOS:000083068300338 ER PT J AU Behr, TM Behe, M Stabin, MG Wehrmann, B Apostolidis, C Molinet, R Koch, L Goldenberg, DM Becker, W AF Behr, TM Behe, M Stabin, MG Wehrmann, B Apostolidis, C Molinet, R Koch, L Goldenberg, DM Becker, W TI Experimental studies on the toxicity and efficacy of alpha- as compared to beta-emitters in radioimmunotherapy SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Gottingen, Dept Nucl Med, D-3400 Gottingen, Germany. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. Inst Transuranium Elements, Karlsruhe, Germany. Garden State Canc Ctr, Belleville, NJ USA. RI Behe, Martin/E-2941-2013 NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA OS35 BP 969 EP 969 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100037 ER PT J AU Nobuhara, K Halldin, C Hall, H Karlsson, P Hiltunen, J McPherson, D Savonen, A Bergstrom, KA Swahn, CG Larsson, S Schnell, PO Farde, L Sedvall, G AF Nobuhara, K Halldin, C Hall, H Karlsson, P Hiltunen, J McPherson, D Savonen, A Bergstrom, KA Swahn, CG Larsson, S Schnell, PO Farde, L Sedvall, G TI Z-IQNP: A potential radioligand for the SPECT study of muscarinic acetylcholine receptors in Alzheimer's disease SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Karolinska Inst, S-10401 Stockholm, Sweden. Univ Kuopio, FIN-70211 Kuopio, Finland. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA OS50 BP 973 EP 973 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100052 ER PT J AU Beets, AL Guhlke, S Biersack, HJ Knapp, FF AF Beets, AL Guhlke, S Biersack, HJ Knapp, FF TI Availability of very high radiopurity rhenium-188 from a clinical-scale generator using a "tandem" concentration system SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. Univ Bonn, Clin Nucl Med, D-5300 Bonn, Germany. NR 0 TC 2 Z9 2 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA OS199 BP 1010 EP 1010 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100201 ER PT J AU Behr, TM Sgouros, G Stabin, MG Behe, M Angerstein, C Apostolidis, C Molinet, R Koch, L Becker, W AF Behr, TM Sgouros, G Stabin, MG Behe, M Angerstein, C Apostolidis, C Molinet, R Koch, L Becker, W TI Studies on the red marrow dosimetry in radioimmunotherapy: Factors influencing the radiation-induced myelotoxicity of beta-, Auger/conversion electron- or alpha-emitters SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Gottingen, Dept Nucl Med, Mem Sloan Kettering Canc Ctr, D-3400 Gottingen, Germany. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. Inst Transuranium Elements, Karlsruhe, Germany. RI Behe, Martin/E-2941-2013 NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA OS351 BP 1048 EP 1048 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100353 ER PT J AU Bishayee, A Howell, RW Srivastava, SC Bouchet, LG Bolch, WE Rao, DV AF Bishayee, A Howell, RW Srivastava, SC Bouchet, LG Bolch, WE Rao, DV TI Marrow sparing advantage of Sn-117m DTDA in the treatment of metastatic bone pain SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Med & Dent New Jersey, New Jersey Med Sch, Dept Radiol, Newark, NJ 07103 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Univ Florida, Dept Nucl & Radiol Engn, Gainesville, FL USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA OS352 BP 1048 EP 1048 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100354 ER PT J AU Liepe, K Hliscs, R Runge, R Kropp, J Knapp, FJ Franke, WG AF Liepe, K Hliscs, R Runge, R Kropp, J Knapp, FJ Franke, WG TI Dose calculation and clinical efficiency of rhenium-188-HEDP in bone metastases SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Hosp Dresden, Dept Nucl Med, Dresden, Germany. Oak Ridge Natl Lab, Dept Nucl Med, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN 37830 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA OS366 BP 1052 EP 1052 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100368 ER PT J AU Sloof, GW Visser, FC Bax, JJ Comans, EFI Knapp, FF AF Sloof, GW Visser, FC Bax, JJ Comans, EFI Knapp, FF TI Differences of DMIPP uptake in myocardial sublayers during experimental ischemia. SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Amsterdam, Acad Med Ctr, NL-1105 AZ Amsterdam, Netherlands. Free Univ Amsterdam Hosp, Amsterdam, Netherlands. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS80 BP 1072 EP 1072 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100450 ER PT J AU Sloof, GW Visser, FC Comans, EFI Teerlink, T Knapp, FF AF Sloof, GW Visser, FC Comans, EFI Teerlink, T Knapp, FF TI Kinetics of a dimethyl-branched fatty acid analog (DMIPP) in experimental myocardial ischemia. SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Amsterdam, Acad Med Ctr, NL-1105 AZ Amsterdam, Netherlands. Free Univ Amsterdam Hosp, Amsterdam, Netherlands. Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS82 BP 1073 EP 1073 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100452 ER PT J AU Coburn, C Beets, AL Wang, F Abumrad, N Febbraio, M Kropp, J Knapp, FF AF Coburn, C Beets, AL Wang, F Abumrad, N Febbraio, M Kropp, J Knapp, FF TI Use of BMIPP to probe CD36 glycoprotein activity in normal and CD36 knockout mice - Demonstration of significant differences in target organ uptake and lipid pool distribution SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Cornell Univ, Coll Med, Ithaca, NY 14853 USA. Univ Dresden, Dresden, Germany. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS121 BP 1083 EP 1083 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100491 ER PT J AU Srivastava, SC Kolsky, KL Joshi, V Sweet, MP Meinken, GE Mausner, LF AF Srivastava, SC Kolsky, KL Joshi, V Sweet, MP Meinken, GE Mausner, LF TI Scandium-47 as a replacement for Cu-67 for radionuclide therapy SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS584 BP 1198 EP 1198 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100954 ER PT J AU Limouris, GS Pirmettis, I Frantzis, AP Shukla, SK Gouliamos, A Voliotopoulos, V Lyra, M Chiotelis, E Knapp, FF Stavraka, A Vlahos, L AF Limouris, GS Pirmettis, I Frantzis, AP Shukla, SK Gouliamos, A Voliotopoulos, V Lyra, M Chiotelis, E Knapp, FF Stavraka, A Vlahos, L TI Re-188 (Sn) labelled-HEDP and -(V) DMSA in the treatment of painful osseous and disseminated soft tissue metastases SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Arete Univ Hosp, Div Nucl Med, Athens Med Fac, Hellas, Greece. NCSR Demokritos, IRRP, Athens, Hellas, Greece. CNR, Rome, Italy. St Eugenio Hosp, Collab Nucl Med Dept, Rome, Italy. Lockheed Martin Energy Res Co, Oak Ridge Natl Lab, Oak Ridge, TN USA. RI Lyra, Maria/A-7958-2012 NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS624 BP 1208 EP 1208 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614100994 ER PT J AU Palmedo, H Bender, H Risse, J Guhlke, S Schoeneich, G Grunwald, F Knapp, FF Biersack, HJ AF Palmedo, H Bender, H Risse, J Guhlke, S Schoeneich, G Grunwald, F Knapp, FF Biersack, HJ TI Pain palliation with rhenium-188 HEDP in prostate cancer patients with osseous metastases. SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Bonn, Dept Nucl Med, D-5300 Bonn, Germany. Univ Bonn, Dept Urol, D-5300 Bonn, Germany. ORNL, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS634 BP 1211 EP 1211 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614101004 ER PT J AU Behr, TM Behe, M Stabin, MG Angerstein, C Mech, R Hagemann, L Apostolidis, C Molinet, R Koch, L Rosch, F Becker, W AF Behr, TM Behe, M Stabin, MG Angerstein, C Mech, R Hagemann, L Apostolidis, C Molinet, R Koch, L Rosch, F Becker, W TI Radiopeptide therapy with cholecystokinin-B gastrin receptor ligands: Dose-limiting toxicity and therapeutic efficacy of Auger/conversion electron (In-111, Nd-140) versus alpha (Bi-213) or conventional beta (Y-90, Sm-153) emitters SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Gottingen, Dept Nucl Med, D-3400 Gottingen, Germany. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, D-7500 Karlsruhe, Germany. Univ Mainz, Inst Nucl Chem, D-6500 Mainz, Germany. RI Behe, Martin/E-2941-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS637 BP 1212 EP 1212 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614101007 ER PT J AU Srivastava, SC Meinken, GE Atkins, HL Mausner, LF James, JL AF Srivastava, SC Meinken, GE Atkins, HL Mausner, LF James, JL TI New formulations of tin-117m stannic chelates for therapy of cancer in bone SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Diatide Inc, Londonderry, NH USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD SEP PY 1999 VL 26 IS 9 MA PS638 BP 1212 EP 1212 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 236TF UT WOS:000082614101008 ER PT J AU Nowak, A Urban, W Kurcewicz, W Rzaca-Urban, T Mach, H Fogelberg, B Durell, JL Leddy, MJ Jones, MA Phillips, WR Smith, AG Varley, BJ Bentaleb, M Lubkiewicz, E Schulz, N Ahmad, I Morss, LR AF Nowak, A Urban, W Kurcewicz, W Rzaca-Urban, T Mach, H Fogelberg, B Durell, JL Leddy, MJ Jones, MA Phillips, WR Smith, AG Varley, BJ Bentaleb, M Lubkiewicz, E Schulz, N Ahmad, I Morss, LR TI New excitation scheme of Cs-139 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID FISSION; NUCLEI; BANDS AB Excited levels in Cs-139: populated in spontaneous fission of Cm-248, have been studied by means of prompt gamma spectroscopy, using the EUROGAMM 2 array. New level scheme of Cs-139, different from the one proposed recently, has been established. To confirm the new scheme, additional study of Cs-139 has been performed; where gamma-rays following beta-decay of Xe-139 to Cs-139 have been measured at the mass separator OSIRIS. C1 Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Uppsala Univ, Dept Neutron Res, S-61182 Nykoping, Sweden. Univ Manchester, Dept Phys & Astron, Schuster Lab, Manchester M13 9PL, Lancs, England. Univ Strasbourg 1, CNRS, IN2P3, Ctr Rech Nucl, F-67037 Strasbourg, France. Argonne Natl Lab, Argonne, IL 60439 USA. RP Nowak, A (reprint author), Univ Warsaw, Inst Expt Phys, Ul Hoza 69, PL-00681 Warsaw, Poland. NR 6 TC 50 Z9 53 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 1999 VL 6 IS 1 BP 1 EP 3 PG 3 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 240WB UT WOS:000082849100001 ER PT J AU Andersson, T Rudolph, D Baktash, C Eberth, J Fahlander, C Haslip, D LaFosse, DR Paul, SD Sarantites, DG Svensson, CE Thomas, HG Waddington, JC Weintraub, W Wilson, JN Brown, BA AF Andersson, T Rudolph, D Baktash, C Eberth, J Fahlander, C Haslip, D LaFosse, DR Paul, SD Sarantites, DG Svensson, CE Thomas, HG Waddington, JC Weintraub, W Wilson, JN Brown, BA TI High-spin states in the A=39 mirror nuclei Ca-39 and K-39 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID GAMMASPHERE AB High-spin states of the mass A = 39 mirror pair K-39 and Ca-39 were investigated via the fusion-evaporation reaction Si-28+O-16 at 125 MeV beam energy. The GAMMASPHERE array in conjunction with the 4 pi charged-particle detector array MICROBALL and neutron detectors was used to detect gamma rays in coincidence with evaporated light particles. The results of the first high-spin study of the T-z = -1/2 nucleus Ca-39 are discussed in terms of mirror symmetry and compared to spherical shell-model calculations in the 1d(3/2)-1f(7/2) configuration space. C1 Univ Lund, Dept Phys, S-22100 Lund, Sweden. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RP Andersson, T (reprint author), Univ Lund, Dept Phys, S-22100 Lund, Sweden. RI Rudolph, Dirk/D-4259-2009 OI Rudolph, Dirk/0000-0003-1199-3055 NR 12 TC 15 Z9 15 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 1999 VL 6 IS 1 BP 5 EP 8 DI 10.1007/s100500050310 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 240WB UT WOS:000082849100002 ER PT J AU Leino, M Kankaanpaa, H Herzberg, RD Chewter, AJ Hessberger, FP Le Coz, Y Becker, F Butler, PA Cocks, JFC Dorvaux, O Eskola, K Gerl, J Greenlees, PT Helariutta, K Houry, M Jones, GD Jones, P Julin, R Juutinen, S Kettunen, H Khoo, TL Kleinbohl, A Korten, W Kuusiniemi, P Lucas, R Muikku, M Nieminen, P Page, RD Rahkila, P Reiter, P Savelius, A Schlegel, C Theisen, C Trzaska, WH Wollersheim, HJ AF Leino, M Kankaanpaa, H Herzberg, RD Chewter, AJ Hessberger, FP Le Coz, Y Becker, F Butler, PA Cocks, JFC Dorvaux, O Eskola, K Gerl, J Greenlees, PT Helariutta, K Houry, M Jones, GD Jones, P Julin, R Juutinen, S Kettunen, H Khoo, TL Kleinbohl, A Korten, W Kuusiniemi, P Lucas, R Muikku, M Nieminen, P Page, RD Rahkila, P Reiter, P Savelius, A Schlegel, C Theisen, C Trzaska, WH Wollersheim, HJ TI In-beam study of No-254 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID HEAVIEST NUCLEI; SHELL STRUCTURE; SEPARATOR; ELEMENTS; SPECTROSCOPY; PARAMETERS; PRODUCTS; SPECTRA; REGION AB Excited states of the Z = 102 nuclide No-254 hale been studied in the reaction Pb-208(Ca-48,2n) by means of in-beam gamma-ray spectroscopy in combination with recoil gating and recoil decay tagging. A Ge detector array, consisting of four clover detectors: and a gas-filled separator were used. Six gamma-ray lines were observed and associated with E2 transitions in the ground state band of No-254, the highest-lying of these being the 16(+) --> 14(+) transition. Based on global systematics and the extrapolated 2(1)(+) excitation energy, the value beta(2) = 0.27+/-0.03 was extracted for the quadrupole deformation. An improved value for the half-life of No-254, T-1/2 = (48+/-3) s; was determined. C1 Univ Jyvaskyla, Dept Phys, FIN-40351 Jyvaskyla, Finland. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Gesell Schwerionenforsch GmbH, D-6100 Darmstadt, Germany. CEA Saclay, DAPNIA, SPhN, Gif Sur Yvette, France. Univ Helsinki, Dept Phys, Helsinki, Finland. Argonne Natl Lab, Argonne, IL USA. LMU Univ, Munich, Germany. RP Leino, M (reprint author), Univ Jyvaskyla, Dept Phys, POB 35, FIN-40351 Jyvaskyla, Finland. RI Gerl, Juergen/A-3255-2011; Houry, Michael/G-8021-2011; Herzberg, Rolf-Dietmar/E-1558-2011; KORTEN, Wolfram/H-3043-2013; THEISEN, Christophe/A-9343-2015; OI THEISEN, Christophe/0000-0002-8509-1022; KORTEN, Wolfram/0000-0002-3940-0816; Butler, Peter/0000-0001-6080-9205 NR 36 TC 121 Z9 123 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 1999 VL 6 IS 1 BP 63 EP 69 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 240WB UT WOS:000082849100010 ER PT J AU Mankiewicz, L Piller, G Radyushkin, A AF Mankiewicz, L Piller, G Radyushkin, A TI Hard exclusive electroproduction of pions SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID PARTON DISTRIBUTIONS; FORM-FACTOR; ASYMPTOTIC-BEHAVIOR; MESONS; QCD; FACTORIZATION; NUCLEON; Q2 AB We investigate the exclusive electroproduction of pi(+) mesons from nucleons. To leading-twist, leading-order cu, accuracy, the corresponding production amplitude can be decomposed into pseudovector and pseudoscalar parts. Both can be expressed in terms of quark double distribution functions of the nucleon. While the pseudovector contribution is connected to ordinary polarized quark distributions, the pseudoscalar Dart can be related to one-pion t-channel exchange. We observe that the pseudovector part of the production amplitude is important at x(Bj) < 0.1. On the other hand, for 0.1 < x(Bj) < 0.4, contributions from one-pion exchange dominate. C1 Tech Univ Munich, Dept Phys, D-85747 Garching, Germany. Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Jefferson Lab, Newport News, VA 23606 USA. Joint Inst Nucl Res Dubna, Theoret Phys Lab, Dubna, Russia. RP Mankiewicz, L (reprint author), Tech Univ Munich, Dept Phys, D-85747 Garching, Germany. RI Mankiewicz, Lech/G-4171-2011 NR 31 TC 79 Z9 79 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD SEP PY 1999 VL 10 IS 2 BP 307 EP 312 DI 10.1007/s100529900045 PG 6 WC Physics, Particles & Fields SC Physics GA 241WM UT WOS:000082906900010 ER PT J AU Lawrence, CM Nelson, DV Udd, E Bennett, T AF Lawrence, CM Nelson, DV Udd, E Bennett, T TI A fiber optic sensor for transverse strain measurement SO EXPERIMENTAL MECHANICS LA English DT Article DE Bragg grating; fiber optic sensor; transverse strain; polarization-maintaining filter ID GRATING SENSORS; TEMPERATURE MODELS; UNIFIED APPROACH; BRAGG GRATINGS; ALIGNMENT AB A fiber optic sensor capable of measuring two independent components of transverse strain is described. The sensor consists of a single Bragg grating written into high-birefringent, polarization-maintaining optical fiber. When light from a broadband source is used to illuminate the sensor, the spectra of light reflected from the Bragg grating contain two peaks corresponding to the two orthogonal polarization modes of the fiber. Two independent components of transverse strain in the core of the fiber can be computed from the changes in wavelength of the two peaks if axial strain and temperature changes in the fiber are zero or known. Experiments were performed to determine the response of the sensor by loading an uncoated sensor in diametral compression over a range of fiber orientations relative to the loading. The results of these experiments were used with a finite element model to determine a calibration matrix relating the transverse strain in the sensor to the wavelength shifts of the Bragg peaks. The performance of the sensor was then verified by measuring the transverse strains produced by loading the fiber in a V-groove fixture. C1 Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. Blue Rd Res, Fairview, OR 97024 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Lawrence, CM (reprint author), Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. NR 19 TC 81 Z9 86 U1 3 U2 22 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD SEP PY 1999 VL 39 IS 3 BP 202 EP 209 DI 10.1007/BF02323553 PG 8 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 228ZD UT WOS:000082166700006 ER PT J AU Guo, Y Ifju, P Boeman, R Dai, F AF Guo, Y Ifju, P Boeman, R Dai, F TI Formation of specimen gratings for moire interferometry applications SO EXPERIMENTAL TECHNIQUES LA English DT Article C1 Motorola Inc, Semicond Prod Sector, Tempe, AZ 85282 USA. Univ Florida, Gainesville, FL USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Tginghua Univ, Beijing, Peoples R China. RP Guo, Y (reprint author), Motorola Inc, Semicond Prod Sector, Tempe, AZ 85282 USA. NR 10 TC 7 Z9 7 U1 0 U2 3 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 USA SN 0732-8818 J9 EXP TECHNIQUES JI Exp. Tech. PD SEP-OCT PY 1999 VL 23 IS 5 BP 28 EP 32 DI 10.1111/j.1747-1567.1999.tb01302.x PG 5 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA 243UZ UT WOS:000083016800007 ER PT J AU Miller, JE Evans, L Littlewolf, A Trudell, DE AF Miller, JE Evans, L Littlewolf, A Trudell, DE TI Batch microreactor studies of lignin and lignin model compound depolymerization by bases in alcohol solvents SO FUEL LA English DT Article DE lignin depolymerization; solvolysis; model compounds ID PROMOTED H-DONATION; COAL CONVERSION; DONOR MEDIA AB The depolymerization of Kraft- and organosolv-derived lignins by KOH in supercritical methanol or ethanol was studied in rapidly heated batch microreactors. High conversions were realized, with only 78 ether insoluble material remaining after treating organosolv lignin in KOH/ethanol at 290 degrees C. The conversion was rapid, reaching the maximum value within 10-15 min. Further studies with KOH, NaOH, CsOH, LiOH, Ca(OH)(2), and Na2CO3 indicate that strong bases give superior conversion, and that combinations of bases can give both positive and negative synergistic effects. An excess of base relative to lignin monomer units was required for maximum conversion. Model compound studies confirm the dominant depolymerization route is the solvolysis of ether linkages. Ethanol solvent is also partially converted to acetic acid, higher alcohols, and other products in addition to alkylating phenolic rings. The formation of acidic products may account for the excess base requirement. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Miller, JE (reprint author), Sandia Natl Labs, POB 5800,MS 0710, Albuquerque, NM 87185 USA. RI Miller, James/C-1128-2011 OI Miller, James/0000-0001-6811-6948 NR 14 TC 125 Z9 141 U1 5 U2 72 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0016-2361 J9 FUEL JI Fuel PD SEP PY 1999 VL 78 IS 11 BP 1363 EP 1366 DI 10.1016/S0016-2361(99)00072-1 PG 4 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 226FU UT WOS:000082010300012 ER PT J AU Raffray, AR Schlosser, J Akiba, M Araki, M Chiocchio, S Driemeyer, D Escourbiac, F Grigoriev, S Merola, M Tivey, R Vieider, G Youchison, D AF Raffray, AR Schlosser, J Akiba, M Araki, M Chiocchio, S Driemeyer, D Escourbiac, F Grigoriev, S Merola, M Tivey, R Vieider, G Youchison, D TI Critical heat flux analysis and RED for the design of the ITER divertor SO FUSION ENGINEERING AND DESIGN LA English DT Article DE ITER; divertor; critical heat flux; mock-up testing ID TUBE AB The vertical target and dump target of the ITER divertor have to be designed for high heat fluxes (up to 20 MW/m(2) over approximate to 10 s). Accommodation of such high heat fluxes gives rise to several issues, including the critical beat flux (CHF) margin which is a key requirement influencing the choice of cooling channel geometry and coolant conditions. An R&D programme was evolved to address the overall CHF issue and to help focus the design. It involved participation of the four ITER home teams and has been very successful in substantially expanding the CHF data base for one-sided heating and in providing more accurate experimental measurements of pressure drop (and derived correlations) for these geometries. This paper describes the major R&D results and the design analysis performed in converging on a choice of reference configuration and parameters which resulted in a CHF margin of approximate to 1.4 or more for all divertor components. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved. C1 EURATOM, Max Planck Inst Plasmaphys, ITER Garching JWS, D-85748 Garching, Germany. CEA Cadarache, Dept Rech Fus Controlee, EURATOM Assoc, F-13108 St Paul Durance, France. JAERI, Naka, Ibaraki 3110193, Japan. Boeing, St Louis, MO 63166 USA. ATEM, F-13009 Marseille, France. Efremov Inst, STC SINTEZ, St Petersburg 189631, Russia. EURATOM, Max Planck Inst Plasmaphys, Net Team, D-85748 Garching, Germany. Sandia Natl Labs, Fus Technol Dept, Albuquerque, NM 87185 USA. RP Raffray, AR (reprint author), EURATOM, Max Planck Inst Plasmaphys, ITER Garching JWS, D-85748 Garching, Germany. NR 35 TC 57 Z9 58 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 1999 VL 45 IS 4 BP 377 EP 407 DI 10.1016/S0920-3796(99)00053-8 PG 31 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 236ET UT WOS:000082586200003 ER PT J AU Lee, DY Chang, CS Manickam, J Pomphrey, N Chance, MS Jardin, SC AF Lee, DY Chang, CS Manickam, J Pomphrey, N Chance, MS Jardin, SC TI Numerical study for design of the passive stabilizer and its impact on MHD stability in the proposed KSTAR plasma SO FUSION ENGINEERING AND DESIGN LA English DT Article DE stabilizer; magnetohydrodynamic stability; parametric study ID RESISTIVE WALL MODE; ADVANCED TOKAMAK; EXTERNAL-MODES; SHELL; SHEAR; BETA AB The effect of the passive plate stabilizer on the ideal magnetohydrodynamic (MHD) stability is numerically studied in order to guide its design in the proposed Korea Superconducting Tokamak Advanced Research (KSTAR). The parametric study is systematically performed by taking into account the two major variables: the plate's distance from the plasma surface, and the poloidal (toroidally continuous) vacuum gap required for the access of neutral beam ports and other diagnostics near the outboard mid-plane. Extensive calculations are carried out on the plasma beta limits for low-n (Iz being toroidal mode number) MHD modes in several major operating regimes. The results lead to a practical and optimistic design point: plasma-wall separation approximate to 10 cm, and the outboard gap having a vertical separation of about 80 cm between the upper and lower plates. This is one of the choices that will make it feasible to achieve the advanced operation with bootstrap current fraction of over 80% at beta(n) = 5 in the reversed shear mode in KSTAR. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Korea Adv Inst Sci & Technol, Ctr Plasma & Fus Studies, Yuseong Ku, Taejon 305701, South Korea. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lee, DY (reprint author), Korea Adv Inst Sci & Technol, Ctr Plasma & Fus Studies, Yuseong Ku, 373-1 Kuseong Dong, Taejon 305701, South Korea. RI Jardin, Stephen/E-9392-2010; pomphrey, neil/G-4405-2010 NR 20 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 1999 VL 45 IS 4 BP 465 EP 474 DI 10.1016/S0920-3796(99)00060-5 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 236ET UT WOS:000082586200008 ER PT J AU Perkins, LJ AF Perkins, LJ TI Antiproton fast ignition for inertial confinement fusion SO FUSION TECHNOLOGY LA English DT Article ID MICROFISSION EXPERIMENTS; GAIN; PHYSICS AB With 180 MJ/mu g, antiprotons offer the highest stored energy per unit mass of any known entity. The use of antiprotons to promote fast ignition in an inertial confinement fusion (ICF) capsule andproduce high target gains with only modest compression of the main fuel is investigated. Unlike standard fast ignition where the ignition energy is supplied by an energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. This can be considered in-situ fast ignition as it obviates the need for the external injection of the ignition energy. In the first of two candidate schemes, the antiproton package is delivered by a low-energy ion beam, In the second, autocatalytic scheme, the antiprotons are preemplaced at the center of the capsule prior to compression. In both schemes, we estimate that similar to 10(12) antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition within the ignitor zone. In addition to eliminating the need for a second, energetic fast laser and vulnerable final optics, this scheme would achieve central ignition without reliance on laser channeling through halo plasma or Hohlraum debris. However, in addition to the practical difficulties of storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a speculative scheme is the ultimate efficiency of antiproton production in an external, optimized facility. Estimates suggest that the electrical wall plug energy per pulse required for the separate production of the antiprotons is of the same order as that required for the conventional slow compression driver. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Perkins, LJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808 L-637, Livermore, CA 94551 USA. NR 37 TC 4 Z9 4 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD SEP PY 1999 VL 36 IS 2 BP 219 EP 233 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 228QJ UT WOS:000082146900009 ER PT J AU Luo, KX Stroschein, SL Wang, W Chen, D Martens, E Zhou, S Zhou, Q AF Luo, KX Stroschein, SL Wang, W Chen, D Martens, E Zhou, S Zhou, Q TI The Ski oncoprotein interacts with the Smad proteins to repress TGF beta signaling SO GENES & DEVELOPMENT LA English DT Article DE Ski; TGF beta; Smad proteins; growth inhibition; signal transduction transcriptional activation ID GROWTH-FACTOR-BETA; TUMOR-SUPPRESSOR SMAD4; DNA-BINDING PROTEIN; C-SKI; TRANSCRIPTIONAL REPRESSION; V-SKI; HISTONE DEACETYLASE; SKELETAL-MUSCLE; N-COR; PROTOONCOGENE AB Smad proteins are critical signal transducers downstream of the receptors of the transforming growth factor-beta (TGF beta) superfamily. On phosphorylation and activation by the active TGF beta receptor complex, Smad2 and Smad3 form hetero-oligomers with Smad4 and translocate into the nucleus, where they interact with different cellular partners, bind to DNA, regulate transcription of various downstream response genes, and cross-talk with other signaling pathways. Here we show that a nuclear oncoprotein, Ski, can interact directly with Smad2, Smad3, and Smad4 on a TGF beta-responsive promoter element and repress their abilities to activate transcription through recruitment of the nuclear transcriptional corepressor N-CoR and possibly its associated histone deacetylase complex. Overexpression of Ski in a TGF beta-responsive cell Line renders it resistant to TGF beta-induced growth inhibition and defective in activation of JunB expression. This ability to overcome TGF beta-induced growth arrest may be responsible for the transforming activity of Ski in human and avian canter cells. Our studies suggest a new paradigm for inactivation of the Smad proteins by an oncoprotein through transcriptional repression. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Sci & Technol China, Dept Biol, Hefei 230026, Anhui, Peoples R China. RP Luo, KX (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 60 TC 327 Z9 350 U1 0 U2 3 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 0890-9369 J9 GENE DEV JI Genes Dev. PD SEP 1 PY 1999 VL 13 IS 17 BP 2196 EP 2206 DI 10.1101/gad.13.17.2196 PG 11 WC Cell Biology; Developmental Biology; Genetics & Heredity SC Cell Biology; Developmental Biology; Genetics & Heredity GA 237GK UT WOS:000082647200002 PM 10485843 ER PT J AU Ashburner, M Misra, S Roote, J Lewis, SE Blazej, R Davis, T Doyle, C Galle, R George, R Harris, N Hartzell, G Harvey, D Hong, L Houston, K Hoskins, R Johnson, G Martin, C Moshrefi, A Palazzolo, M Reese, MG Spradling, A Tsang, G Wan, K Whitelaw, K Kimmel, B Celniker, S Rubin, GM AF Ashburner, M Misra, S Roote, J Lewis, SE Blazej, R Davis, T Doyle, C Galle, R George, R Harris, N Hartzell, G Harvey, D Hong, L Houston, K Hoskins, R Johnson, G Martin, C Moshrefi, A Palazzolo, M Reese, MG Spradling, A Tsang, G Wan, K Whitelaw, K Kimmel, B Celniker, S Rubin, GM TI An exploration of the sequence of a 2.9-Mb region of the genome of Drosophila melanogaster: The Adh region SO GENETICS LA English DT Review ID SMALL AUTOSOMAL REGION; MITOCHONDRIAL-DNA POLYMERASE; MATERNAL-EFFECT MUTATIONS; ARTIFICIAL-CHROMOSOME LIBRARIES; ANGIOTENSIN-CONVERTING ENZYME; PERIPHERAL NERVOUS-SYSTEM; LARGE TRANSPOSING ELEMENT; PROTEIN-KINASE ACTIVITY; REPEATED GENE FAMILIES; YEAST GOLGI-APPARATUS AB A contiguous sequence of nearly 3 Mb from the genome of Drosophila melanogaster has been sequenced from a series of overlapping P1 and BAC clones. This region covers 69 chromosome polytene bands on chromosome arm 2L, including the genetically well-characterized "Adh region." A computational analysis of the sequence predicts 218 protein-coding genes, 11 tRNAs, and iii transposable element sequences. At least 38 of the protein-coding genes are arranged in clusters of from 2 to 6 closely related genes, suggesting extensive tandem duplication. The gene density is one protein-coding gene every 13 kb; the transposable element density is one element every 171 kb. Of 73 genes in this region identified by genetic analysis, 49 have been located on the sequence; P-element insertions have been mapped to 43 genes. Ninety-five (44%) of the known and predicted genes match a Drosophila EST, and 144 (66%) have clear similarities to proteins in other organisms. Genes known to have mutant phenotypes are more likely to be represented in cDNA libraries, and far more likely to have products similar to proteins of other organisms, than are genes with no known mutant phenotype. Over 650 chromosome aberration breakpoints map to this chromosome region, and their nonrandom distribution on the genetic map reflects variation in gene spacing on the DNA. This is the first large-scale analysis of the genome of D. melanogaster at the sequence level. In addition to the direct results obtained, this analysis has allowed us to develop and test methods that will be needed to interpret the complete sequence of the genome of this species. C1 Univ Cambridge, Dept Genet, Cambridge CB2 3EH, England. EMBL, European Bioinformat Inst, Cambridge CB10 1SD, England. Cardiff Univ, Dept Pathol, Cardiff CF4 4XN, S Glam, Wales. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Carnegie Inst Sci, Howard Hughes Med Inst, Baltimore, MD USA. Lawrence Berkeley Lab, Berkeley Drosophila Genome Project, Berkeley, CA 94720 USA. RP Univ Cambridge, Dept Genet, Downing St, Cambridge CB2 3EH, England. EM m.ashburner@gen.cam.ac.uk OI Lewis, Suzanna/0000-0002-8343-612X; Rubin, Gerald/0000-0001-8762-8703 FU Howard Hughes Medical Institute; NHGRI NIH HHS [P50 HG00750]; Wellcome Trust NR 261 TC 193 Z9 232 U1 0 U2 11 PU GENETICS SOCIETY AMERICA PI BETHESDA PA 9650 ROCKVILLE AVE, BETHESDA, MD 20814 USA SN 0016-6731 EI 1943-2631 J9 GENETICS JI Genetics PD SEP PY 1999 VL 153 IS 1 BP 179 EP 219 PG 41 WC Genetics & Heredity SC Genetics & Heredity GA 233HN UT WOS:000082421600014 PM 10471707 ER PT J AU Feng, H Cochran, JK Hirschberg, DJ AF Feng, H Cochran, JK Hirschberg, DJ TI Th-234 and Be-7 as tracers for the transport and dynamics of suspended particles in a partially mixed estuary SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID LONG-ISLAND SOUND; AMAZON SHELF; URANIUM GEOCHEMISTRY; RIVER-ESTUARINE; COASTAL WATERS; CHESAPEAKE BAY; SEDIMENTS; BERYLLIUM-7; ISOTOPES; COLLOIDS AB The sources of the natural radionuclides Th-234 (half-life = 24 d) and Be-7 (half-life = 53 d) to the partially mixed Hudson River estuary are distinctly different: Th-234 is produced from decay of dissolved U-238 that varies conservatively as a function of salinity, and Be-7 is added directly from the atmosphere. Th-234 and Be-7 activities were measured in suspended and bottom sediments under varying conditions of river flow to evaluate the relative importance of local sediment resuspension and advection of suspended sediments through the estuary. Both radionuclides are removed from the estuarine water column on time scales of from <1 to 13 d. The Th-234(xs)/Be-7 activity ratio is used to eliminate variations in the specific activities caused by grain size or sediment compositional changes. A simple steady-state model is used to set limits on the activity ratios expected if local processes tin situ production of Th-234, atmospheric supply of Be-7, scavenging, particle settling, and resuspension) dominate the activity ratio. During low river discharge, observed Th-234(xs)/Be-7 ratios exceed the model upper limits in the higher salinity portions of the estuary. suggesting that particles labeled with Th and Be in higher salinities are transported to lower salinities with the estuarine circulation. Distance scales of particle transport are estimated to be from 10 to 20 km, comparable to the tidal excursion. Sampling during a high-flow event of short duration shows that the activity ratios tend toward the lower limit. Such a pattern could be produced by down-river transport of particles or by enhanced resuspension. Similarities between the Th-234(xs)/Be-7 activity ratios of suspended and bottom sediments suggest that increases in resuspension during high flow events dominate the activity ratio in the suspended sediment reservoir. Copyright (C) 1999 Elsevier Science Ltd. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. RP Feng, H (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 44 TC 50 Z9 55 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1999 VL 63 IS 17 BP 2487 EP 2505 DI 10.1016/S0016-7037(99)00060-5 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 242NX UT WOS:000082948100002 ER PT J AU Teng, HH Dove, PM DeYoreo, JJ AF Teng, HH Dove, PM DeYoreo, JJ TI Reversed calcite morphologies induced by microscopic growth kinetics: Insight into biomineralization SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID FORCE MICROSCOPY; CRYSTAL-GROWTH; SPIRAL GROWTH; SURFACE; CRYSTALLIZATION; PROTEINS; MACROMOLECULES; DISSOLUTION; MECHANISM; IMAGES AB This experimental investigation of calcite growth quantifies relationships between solution supersaturation and the rates of step advancement. Using in situ fluid cell atomic force microscopy (AFM), we show that the movement of monomolecular steps comprising growth hillocks on {10(1) over bar 4} faces during the growth of this anisotropic material is specific to crystallographic direction. By quantifying the sensitivity of step growth kinetics to supersaturation, we can produce spiral hillocks with unique geometries. These forms are caused by a complex dependence of step migration rates, nu(s+) and nu(s-), upon small differences in solution chemistry as they grow normal to the conventional fast ([(4) over bar 41](+) and [481](+)) and slow ([(4) over bar 41](-_) and [48(1) over bar](-)) crystallographic directions. As solute activity, a, decreases, nu(s+) and nu(s-) converge and growth hillocks express a pseudoisotropic form. At still lower supersaturations where a approaches its equilibrium value, a(e), an inversion in the rates of step advancement produces hillocks with unusual reversed geometries. Comparisons of the kinetic data with classical theoretical models suggest that the observed behavior may be due to minute impurities that impact the kinetics of growth through blocking and incorporation mechanisms. These findings demonstrate the control of crystallographic structure on the local-scale kinetics of growth to stabilize the formation of unusual hillock morphologies at the near-equilibrium conditions found in natural environments. Copyright (C) 1999 Elsevier Science Ltd. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Dove, PM (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RI Dove, Patricia/A-7911-2010 NR 32 TC 98 Z9 99 U1 10 U2 43 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1999 VL 63 IS 17 BP 2507 EP 2512 DI 10.1016/S0016-7037(99)00103-9 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 242NX UT WOS:000082948100003 ER PT J AU Kohn, MJ Schoeninger, MJ Barker, WW AF Kohn, MJ Schoeninger, MJ Barker, WW TI Altered states: Effects of diagenesis on fossil tooth chemistry SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID OXYGEN-ISOTOPE COMPOSITIONS; RARE-EARTH ELEMENTS; BONE PHOSPHATE; ENAMEL PHOSPHATE; ARCHAEOLOGICAL BONE; HAYONIM CAVE; STRONTIUM; DIET; CARBONATE; TEETH AB Investigation of modern and fossil teeth from northern and central Kenya, using the ion microprobe, electron microprobe, and transmission electron microscope, confirms that fossil tooth chemistry is controlled not only by the diagenetic precipitation of secondary minerals but also by the chemical alteration of the biogenic apatite. Increases in the concentrations of Fe, Mn, Si, Al, Ba, and possibly Cu in fossil vs. modern teeth reflect mixtures of apatite and secondary minerals. These secondary minerals occur in concentrations ranging from similar to 0.3% in enamel to similar to 5% in dentine and include sub-mu m, interstitial Fe-bearing manganite [(Fe3+ Mn3+)O(OH)], and smectite. The pervasive distribution and fine grain size of the secondary minerals indicate that mixed analyses of primary and secondary material are unavoidable in in situ methods, even in ion microprobe spots only 10 mu m in diameter, and that bulk chemical analyses are severely biased. Increases in other elements, including the rare earth elements, U, F, and possibly Sr apparently reflect additional alteration of apatite in both dentine and enamel. Extreme care will be required to separate secondary minerals from original biogenic apatite for paleobiological or paleoclimate studies, and nonetheless bulk analyses of purified apatite may be suspect. Although the PO4 component of teeth seems resistant to chemical alteration, the OH component is extensively altered. This OH alteration implies that bulk analyses of fossil tooth enamel for oxygen isotope composition may be systematically biased by +/- 1 parts per thousand, and seasonal records of oxygen isotope composition may be spuriously shifted, enhanced, or diminished. Copyright (C) 1999 Elsevier Scieizce Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Wisconsin, Dept Anthropol, Madison, WI 53706 USA. Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. RP Kohn, MJ (reprint author), Univ S Carolina, Dept Geol Sci, Columbia, SC 29208 USA. RI Kohn, Matthew/A-2562-2012 NR 68 TC 213 Z9 214 U1 9 U2 48 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1999 VL 63 IS 18 BP 2737 EP 2747 DI 10.1016/S0016-7037(99)00208-2 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 243TN UT WOS:000083013500004 ER PT J AU Kent, AJR Clague, DA Honda, M Stolper, EM Hutcheon, ID Norman, MD AF Kent, AJR Clague, DA Honda, M Stolper, EM Hutcheon, ID Norman, MD TI Widespread assimilation of a seawater-derived component at Loihi Seamount, Hawaii SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID DIVERSE BASALT TYPES; EAST PACIFIC RISE; NOBLE-GASES; ISOTOPIC COMPOSITION; HYDROTHERMAL SYSTEM; SUBMARINE BASALTS; PHASE-SEPARATION; MAJOR-ELEMENT; RIDGE; GLASSES AB Many tholeiitic and transitional pillow-rim and fragmental glasses from Loihi seamount, Hawaii, have high Cl contents and Cl/K2O ratios land ratios of Cl to other incompatible components, such as P2O5, H2O, etc.) relative to other Hawaiian subaerial volcanoes (e.g., Mauna Loa, Mauna Kea, and Kilauea). We suggest that this results from widespread contamination of Loihi magmas by a Cl-rich, seawater-derived component. Assimilation of high-Cl phases such as saline brine or Cl-rich minerals (halite or iron- hydroxychlorides) with high Cl/H2O ratios can explain the range and magnitude of Cl contents in Loihi glasses, as well as the variations in the ratios of Cl to other incompatible elements. Brines and Cl-rich minerals are thought to form from seawater within the hydrothermal systems associated with submarine volcanoes, and Loihi magmas could plausibly have assimilated such materials from the hydrothermal envelope adjacent to the magma chamber. Our model can also explain semiquantitatively the observed contamination of Loihi glasses with atmospheric-derived noble gases, provided the assimilant has concentrations of Ne and Ar comparable to or slightly less than seawater. This is more likely for brines than for Cl-rich minerals, leading us to favor brines as the major assimilant. Cl/Br ratios for a limited number of Loihi samples are also seawater-like, and show no indication of the higher values expected to be associated with the assimilation of Cl-rich hydrothermal minerals. Although Cl enrichment is a common feature of lavas from Loihi, submarine glasses from other Hawaiian volcanoes show little (Kilauea) or no (Mauna Loa, Mauna Kea) evidence of this process, suggesting that assimilation of seawater-derived components is more likely to occur in the early stages of growth of oceanic volcanoes. Summit collapse events such as the one observed at Loihi in October 1996 provide a ready mechanism for depositing brine-bearing rocks from the volcanic edifice into the top of a submarine summit magma chamber. Copyright (C) 1999 Elsevier Science Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia. Univ Tasmania, Sch Earth Sci, Ctr Ore Deposit Res, Hobart, Tas 7001, Australia. RP Kent, AJR (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-202, Livermore, CA 94551 USA. OI Honda, Masahiko/0000-0002-9545-9855 NR 60 TC 72 Z9 73 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1999 VL 63 IS 18 BP 2749 EP 2761 DI 10.1016/S0016-7037(99)00215-X PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 243TN UT WOS:000083013500005 ER PT J AU Johnson, TM Herbel, MJ Bullen, TD Zawislanski, PT AF Johnson, TM Herbel, MJ Bullen, TD Zawislanski, PT TI Selenium isotope ratios as indicators of selenium sources and oxyanion reduction SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ELEMENTAL SELENIUM; MASS-SPECTROMETRY; SULFATE; FRACTIONATION; SULFUR; SYSTEM; SOILS; WATER; GEOCHEMISTRY; SEDIMENTS AB Selenium stable isotope ratio measurements should serve as indicators of sources and biogeochemical transformations of Se. We report measurements of Se isotope fractionation during selenate reduction, selenite sorption, oxidation of reduced Se in soils, and Se volatilization by algae and soil samples. These results, combined with previous work with Se isotopes, indicate that reduction of soluble oxyanions is the dominant cause of Se isotope fractionation. Accordingly, Se isotope ratios should be useful as indicators of oxyanion reduction, which can transform mobile species to forms that are less mobile and less bioavailable. Additional investigations of Se isotope fractionation are needed to confirm this preliminary assessment. We have developed a new method for measurement of natural Se isotope ratio variation which requires less than 500 ng Se per analysis and yields +/-0.2 parts per thousand precision on Se-80/Se-76. A double isotope spike technique corrects for isotopic fractionation during sample preparation and mass spectrometry. The small minimum sample size is important, as Se concentrations are often below 1 ppm in solids and 1 mu g/L in fluids. The Se purification process is rapid and compatible with various sample matrices, including acidic rock or sediment digests. Copyright (C) 1999 Elsevier Science Ltd. C1 Univ Illinois, Dept Geol, Champaign, IL 61820 USA. US Geol Survey, Div Water Resources, Menlo Park, CA 94025 USA. EO Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Johnson, TM (reprint author), Univ Illinois, Dept Geol, 245 Nat Hist Bldg,MC-102, Champaign, IL 61820 USA. RI Johnson, Thomas/A-2740-2008 OI Johnson, Thomas/0000-0003-1620-1408 NR 62 TC 89 Z9 98 U1 2 U2 28 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1999 VL 63 IS 18 BP 2775 EP 2783 DI 10.1016/S0016-7037(99)00279-3 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 243TN UT WOS:000083013500007 ER PT J AU James, ER Manga, M Rose, TP AF James, ER Manga, M Rose, TP TI CO2 degassing in the Oregon cascades SO GEOLOGY LA English DT Article ID CARBON-DIOXIDE EMISSIONS; MAMMOTH MOUNTAIN; KILAUEA VOLCANO; HEAT-FLOW; RANGE; FLUXES; CALIFORNIA; DISCHARGE; VOLATILES; ISOTOPES AB The carbon isotope content of dissolved inorganic carbon was measured for large cold springs in the central Oregon Cascades. Low C-14 activities in some of the springs are interpreted to result from the dissolution of diffuse emissions of magmatic CO2, even though volcanic activity has not occurred in this area for more than 1300 yr. On the basis of dissolved magmatic carbon concentrations in the springs, we infer a diffuse magmatic CO2 degassing rate of 3.4 x 10(5) kg/yr per kilometer of are for the central Oregon Cascades. The CO2 flux calculated from estimates of the mean magmatic intrusion rate and experimentally determined values of CO2 content in melts is consistent with that determined from our measurements of the dissolved CO2 flux at springs. C1 Univ Oregon, Dept Geol Sci, Eugene, OR 97403 USA. Univ Calif Lawrence Livermore Natl Lab, Isotope Sci Div, Livermore, CA 94550 USA. RP James, ER (reprint author), Univ Oregon, Dept Geol Sci, Eugene, OR 97403 USA. RI Manga, Michael/D-3847-2013; OI Manga, Michael/0000-0003-3286-4682 NR 38 TC 35 Z9 36 U1 0 U2 8 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 1999 VL 27 IS 9 BP 823 EP 826 DI 10.1130/0091-7613(1999)027<0823:CDITOC>2.3.CO;2 PG 4 WC Geology SC Geology GA 235DE UT WOS:000082524100014 ER PT J AU Oraevskii, VN Choueri, E Dokukin, VS Volokitin, AS Pulinets, SA Ruzhin, YY Afonin, VV AF Oraevskii, VN Choueri, E Dokukin, VS Volokitin, AS Pulinets, SA Ruzhin, YY Afonin, VV TI APEKS: Experiments with the release of neutral xenon SO GEOMAGNETIZM I AERONOMIYA LA Russian DT Article C1 Russian Acad Sci, Inst Earth Magnet Ionosphere & Radiowave Dispers, Troitsk, Russia. Russian Acad Sci, Inst Space Study, Moscow, Russia. Princeton Univ, Elect Propuls & Plasma Dynam Lab, Princeton, NJ 08544 USA. RP Oraevskii, VN (reprint author), Russian Acad Sci, Inst Earth Magnet Ionosphere & Radiowave Dispers, Troitsk, Russia. RI Pulinets, Sergey/F-7462-2011 OI Pulinets, Sergey/0000-0003-3944-6686 NR 9 TC 0 Z9 0 U1 0 U2 0 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0016-7940 J9 GEOMAGN AERON+ JI Geomagn. Aeron. PD SEP-OCT PY 1999 VL 39 IS 5 BP 46 EP 56 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 255RY UT WOS:000083685000007 ER PT J AU Rodgers, AJ Walter, WR Mellors, RJ Al-Amri, AMS Zhang, YS AF Rodgers, AJ Walter, WR Mellors, RJ Al-Amri, AMS Zhang, YS TI Lithospheric structure of the Arabian Shield and Platform from complete regional waveform modelling and surface wave group velocities SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE crustal structure; lithosphere; surface waves; waveform analysis ID CRUSTAL STRUCTURE; PENINSULA; BENEATH AB Regional seismic waveforms reveal significant differences in the structure of the Arabian Shield and the Arabian Platform. We estimate lithospheric velocity structure by modelling regional waveforms recorded by the 1995-1997 Saudi Arabian Temporary Broadband Deployment using a grid search scheme. We employ a new method whereby we narrow the waveform modelling grid search by first fitting the fundamental mode Love and Rayleigh wave group velocities. The group velocities constrain the average crustal thickness and velocities as well as the crustal velocity gradients. Because the group velocity fitting is computationally much faster than the synthetic seismogram calculation this method allows us to determine good average starting models quickly. Waveform fits of the Pn and Sn body wave arrivals constrain the mantle velocities. The resulting lithospheric structures indicate that the Arabian Platform has an average crustal thickness of 40 km, with relatively low crustal velocities (average crustal P- and S-wave velocities of 6.07 and 3.50 km s(-1), respectively) without a strong velocity gradient. The Moho is shallower (36 km) and crustal velocities are 6 per cent higher (with a velocity increase with depth) for the Arabian Shield. Fast crustal velocities of the Arabian Shield result from a predominantly mafic composition in the lower crust. Lower velocities in the Arabian Platform crust indicate a bulk felsic composition, consistent with orogenesis of this former active margin. P- and S-wave velocities immediately below the Moho are slower in the Arabian Shield than in the Arabian Platform (7.9 and 4.30 km s(-1), and 8.10 and 4.55 km s(-1), respectively). This indicates that the Poisson's ratios for the uppermost mantle of the Arabian Shield and Platform are 0.29 and 0.27, respectively. The lower mantle velocities and higher Poisson's ratio beneath the Arabian Shield probably arise from a partially molten mantle associated with Red Sea spreading and continental volcanism, although we cannot constrain the lateral extent of a zone of partially molten mantle. C1 Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, Livermore, CA 94551 USA. San Diego State Univ, Dept Geol Sci, San Diego, CA 92182 USA. King Saud Univ, Geophys Observ, Riyadh, Saudi Arabia. Univ Calif Santa Cruz, Inst Tecton, Santa Cruz, CA 95064 USA. RP Rodgers, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, POB 808, Livermore, CA 94551 USA. RI Rodgers, Arthur/E-2443-2011; Walter, William/C-2351-2013; Mellors, Robert/K-7479-2014 OI Walter, William/0000-0002-0331-0616; Mellors, Robert/0000-0002-2723-5163 NR 18 TC 53 Z9 54 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD SEP PY 1999 VL 138 IS 3 BP 871 EP 878 DI 10.1046/j.1365-246x.1999.00918.x PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 235KY UT WOS:000082541900021 ER PT J AU Xu, YS Shankland, TJ AF Xu, YS Shankland, TJ TI Electrical conductivity of orthopyroxene and its high pressure phases SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER-MANTLE; SILICATE PEROVSKITE; OLIVINE; TRANSITION; PYROXENE AB Electrical conductivity of orthopyroxene, clinopyroxene and ilmenite + garnet with the same starting material San Carlos orthopyroxene (Mg0.92Fe0.08)SiO3 containing 2.89 % Al2O3 by weight were measured within their respective stability fields in a multi-anvil press. In the formula for conductivity sigma = sigma(0) exp(-Delta H/kT), pre-exponential factors sigma(0) of orthopyroxene, clinopyroxene, and ilmenite + garnet are 5248, 1778, 2239 S/m, respectively, and the activation enthalpies are 1.80, 1.87 and 1.66 eV, respectively. These results are required for defining a laboratory-based conductivity-depth profile of the upper mantle. C1 Univ Bayreuth, Bayer Geoinst, D-95440 Bayreuth, Germany. Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Xu, YS (reprint author), Univ Bayreuth, Bayer Geoinst, Postfach 101251, D-95440 Bayreuth, Germany. NR 22 TC 44 Z9 50 U1 3 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 SEP 1 PY 1999 VL 26 IS 17 BP 2645 EP 2648 DI 10.1029/1999GL008378 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 232VR UT WOS:000082391100002 ER PT J AU Lowman, JP Gable, CW AF Lowman, JP Gable, CW TI Thermal evolution of the mantle following continental aggregation in 3D convection models SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID FLOW; SUPERCONTINENTS; PLATES AB The claim that supercontinents insulate the mantle is largely based on recognition that seismically slow mantle below the Atlantic-African geoid high coincides with the former location of Pangea. We investigate the viability of continental insulation by varying both plate geometries and mantle properties in six three-dimensional (3D) mantle convection models. The efficiency of continental insulation is quantified by calculating the rate of change of the average temperature in the subcontinental mantle. Our findings generally agree with two-dimensional (2D) modeling results. However, we conclude that 2D convection models may exaggerate subcontinental heating, particularly in largely bottom heated cases, and that subcontinental heating results from an absence of subduction in the subcontinental mantle rather than the insulation of active upwellings. Correspondingly, we find that when large degrees of internal heating are present in the mantle, hotter-than-average regions evolve below large oceanic plates. C1 Univ Calif Los Alamos Natl Lab, Inst Geophys & Planetary Phys, Los Alamos, NM 87545 USA. RP Lowman, JP (reprint author), Univ Calif Los Alamos Natl Lab, Inst Geophys & Planetary Phys, MS C305, Los Alamos, NM 87545 USA. RI Gable, Carl/B-4689-2011; OI Gable, Carl/0000-0001-7063-0815 NR 13 TC 31 Z9 32 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1999 VL 26 IS 17 BP 2649 EP 2652 DI 10.1029/1999GL008332 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 232VR UT WOS:000082391100003 ER PT J AU Lawrence, DJ Feldman, WC Barraclough, BL Binder, AB Elphic, RC Maurice, S Miller, MC Prettyman, TH AF Lawrence, DJ Feldman, WC Barraclough, BL Binder, AB Elphic, RC Maurice, S Miller, MC Prettyman, TH TI High resolution measurements of absolute thorium abundances on the lunar surface SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ORIGIN; MOON AB The Lunar Prospector (LP) Gamma-Ray Spectrometer (GRS) has been used to map the global abundance of thorium on the lunar surface. A global map of absolute thorium abundances on a 2 degrees by 2 degrees equal-area pixel scale is presented using new detector modeling results and low altitude LP data. Because thorium is relatively abundant in KREEP-rich material, these data provide fundamental information regarding the locations and importance of terranes that are rich in KREEP bearing materials. C1 Univ Calif Los Alamos Natl Lab, Grp NIS1, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Lunar Res Inst, Tucson, AZ USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Los Alamos Natl Lab, Grp NIS5, Los Alamos, NM 87545 USA. RP Lawrence, DJ (reprint author), Univ Calif Los Alamos Natl Lab, Grp NIS1, MS D466, Los Alamos, NM 87545 USA. RI Lawrence, David/E-7463-2015; OI Lawrence, David/0000-0002-7696-6667; Prettyman, Thomas/0000-0003-0072-2831 NR 23 TC 64 Z9 70 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1999 VL 26 IS 17 BP 2681 EP 2684 DI 10.1029/1999GL008361 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 232VR UT WOS:000082391100011 ER PT J AU McComas, DJ Funsten, HO Gosling, JT Pryor, WR AF McComas, DJ Funsten, HO Gosling, JT Pryor, WR TI Ulysses measurements of variations in the solar wind-interstellar hydrogen charge exchange rate SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOSPHERE; IONS; ORIGIN AB Charge exchange with solar wind protons is the primary ionization process for interstellar hydrogen traveling through the heliosphere. In this study we use Ulysses solar wind observations to examine and quantify variations in charge exchange. We find that these variations are largest within stream interaction regions where the charge exchange rate is tens of times larger in compressional, corotating interaction regions (CIRs) than in rarefactions. Similarly, we find enhanced charge exchange in compression regions ahead of fast CMEs. As a consequence, much of the interstellar hydrogen at low latitudes is picked up in pulses as CIRs and fast CMEs sweep past. Observations over Ulysses' first full polar orbit indicate that the charge exchange rate is higher at low than at high latitudes, and that this rate drops off more slowly than the inverse square of heliocentric distance. We believe that this is due to the growth of CIRs as they propagate out through the inner heliosphere. The variability of hydrogen charge exchange has implications for the analysis of scattered Lyman-a observations and produces variations in the pickup rates of newly ionized interstellar hydrogen, which is a seed population for anomalous cosmic rays. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Colorado, Boulder, CO 80303 USA. RP McComas, DJ (reprint author), Univ Calif Los Alamos Natl Lab, D466, Los Alamos, NM 87545 USA. RI Funsten, Herbert/A-5702-2015 OI Funsten, Herbert/0000-0002-6817-1039 NR 17 TC 19 Z9 19 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1999 VL 26 IS 17 BP 2701 EP 2704 DI 10.1029/1999GL900519 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 232VR UT WOS:000082391100016 ER PT J AU Schmid, B Michalsky, J Halthore, R Beauharnois, M Harrison, L Livingston, J Russell, P Holben, B Eck, T Smirnov, A AF Schmid, B Michalsky, J Halthore, R Beauharnois, M Harrison, L Livingston, J Russell, P Holben, B Eck, T Smirnov, A TI Comparison of aerosol optical depth from four solar radiometers during the Fall 1997 ARM Intensive Observation Period SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SCATTERING; INSTRUMENT AB In the Fall of 1997 the Atmospheric Radiation Measurement (ARM) program conducted an Intensive Observation Period (IOP) to study aerosols. Five sun-tracking radiometers were present to measure the total column aerosol optical depth. This comparison performed on the Southern Great Plains (SGP) demonstrates the capabilities and limitations of modern tracking sunphotometers at a location typical of where aerosol measurements are required. The key result was agreement in aerosol optical depth measured by 4 of the 5 instruments within 0.015 (rms). The key to this level of agreement was meticulous care in the calibrations of the instruments. C1 Bay Area Environm Res Inst, San Francisco, CA 94122 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12203 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. SRI Int, Menlo Park, CA 94025 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Raytheon ITSS Corp, Lanham, MD USA. Sci Syst & Applicat Inc, Lanham, MD USA. RP Schmid, B (reprint author), Bay Area Environm Res Inst, 3430 Noriega St, San Francisco, CA 94122 USA. RI Smirnov, Alexander/C-2121-2009; ECK, THOMAS/D-7407-2012 OI Smirnov, Alexander/0000-0002-8208-1304; NR 12 TC 83 Z9 84 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1999 VL 26 IS 17 BP 2725 EP 2728 DI 10.1029/1999GL900513 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 232VR UT WOS:000082391100022 ER PT J AU Huang, LJ Fehler, MC Wu, RS AF Huang, LJ Fehler, MC Wu, RS TI Extended local Born Fourier migration method SO GEOPHYSICS LA English DT Article ID MEDIA AB A migration approach based on a local application of the Born approximation within each extrapolation interval contains a singularity that can make direct application unstable. Previous authors have suggested adding an imaginary part to the vertical wavenumber to eliminate the singularity. However, their method requires that the reference slowness must be the maximum slowness of a given layer; consequently, the slowness perturbations are larger than those when the average slowness is selected as a reference slowness. Therefore, its applicability is limited. We develop an extended local Born Fourier migration method that circumvents the singularity problem of the local Born solution and makes it possible to choose the average slowness as a reference slowness. It is computationally efficient because of the use of a fast Fourier transform algorithm. It can handle wider angles (or steeper interfaces) and scattering effects of heterogeneities more accurately than the split-step Fourier (SSF) method, which accounts for only the phase change as a result of the slowness perturbations but not amplitude change. To handle large lateral slowness variations, we introduce different reference slownesses in different regions of a medium to ensure the condition of small perturbation. The migration result obtained using the extended local Born Fourier method with multiple reference slownesses demonstrates that the method can produce high-quality images of complex structures with large lateral slowness variations. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Inst Tecton, Santa Cruz, CA 95064 USA. RP Huang, LJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Mail Stop D443, Los Alamos, NM 87545 USA. NR 25 TC 52 Z9 83 U1 0 U2 3 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 1999 VL 64 IS 5 BP 1524 EP 1534 DI 10.1190/1.1444656 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 245QR UT WOS:000083120100019 ER PT J AU Huang, LJ Fehler, MC Roberts, PM Burch, CC AF Huang, LJ Fehler, MC Roberts, PM Burch, CC TI Extended local Rytov Fourier migration method SO GEOPHYSICS LA English DT Article ID FINITE-DIFFERENCE MIGRATION; RAY-KIRCHHOFF MIGRATION; REVERSE-TIME MIGRATION; DEPTH MIGRATION; DIFFRACTION TOMOGRAPHY; SEISMIC DATA; INTERPOLATION; MEDIA AB We develop a novel depth-migration method termed the extended local Rytov Fourier (ELRF) migration method. It is based on the scalar wave equation and a local application of the Rytov approximation within each extrapolation interval. Wavefields are Fourier transformed back and forth between the frequency-space and frequency-wavenumber domains during wavefield extrapolation. The lateral slowness variations are taken into account in the frequency-space domain. The method is efficient due to the use of a fast Fourier transform algorithm. Under the small angle approximation, the ELRF method leads to the split-step Fourier (SSF) method that is unconditionally stable. The ELRF method and the extended local Born Fourier (ELBF) method that we previously developed can handle wider propagation angles than the SSF method and account for the phase and amplitude changes due to the lateral variations of slowness, whereas the SSF method only accounts for the phase changes. The stability of the ELRF method is controlled more easily than that of the ELBF method. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Conoco Inc, Ponca City, OK 74602 USA. RP Huang, LJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Mail Stop D443, Los Alamos, NM 87545 USA. NR 44 TC 30 Z9 47 U1 0 U2 1 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 1999 VL 64 IS 5 BP 1535 EP 1545 DI 10.1190/1.1444657 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 245QR UT WOS:000083120100020 ER PT J AU Berryman, JG AF Berryman, JG TI Origin of gassmann's equations SO GEOPHYSICS LA English DT Article C1 Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, POB 808,L-200, Livermore, CA 94551 USA. EM berryman1@llnl.gov RI Berryman, James/A-9712-2008 NR 6 TC 72 Z9 82 U1 2 U2 13 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 EI 1942-2156 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 1999 VL 64 IS 5 BP 1627 EP 1629 DI 10.1190/1.1444667 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 245QR UT WOS:000083120100030 ER PT J AU Paglieroni, DW AF Paglieroni, DW TI A complexity analysis for directional parametric height field ray tracing SO GRAPHICAL MODELS AND IMAGE PROCESSING LA English DT Article DE directional parameter plane transform; incremental methods; hierarchical methods; directional parametric methods; ray coherence ID TRANSFORM AB It has been shown that height field ray tracing efficiency can be improved by traversing rays in steps across evenly spaced inverted cones of empty space centered above height field cells. This approach, referred to as linear parametric height field ray tracing, has previously been extended by directionalizing the inverted cones, i.e., by allowing the opening angles of the inverted cones to vary between sectors. This paper provides a mathematical analysis of parametric ray tracing complexity as a function of cone sector width and height field resolution. Empirical data on ray tracing run-times and mean lengths of traversal steps along rays during ray tracing is presented. It is shown that parametric height field ray tracing can be substantially more efficient than other popular height field ray tracing methods when cones with narrow sectors are used. (C) 1999 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Paglieroni, DW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 20 TC 2 Z9 3 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3169 J9 GRAPH MODEL IM PROC JI Graph. Models Image Process. PD SEP PY 1999 VL 61 IS 5 BP 299 EP 321 DI 10.1006/gmip.1999.0503 PG 23 WC Computer Science, Software Engineering SC Computer Science GA 243RU UT WOS:000083011700004 ER PT J AU Lu, GP Clement, TP Zheng, CM Wiedemeier, TH AF Lu, GP Clement, TP Zheng, CM Wiedemeier, TH TI Natural attenuation of BTEX compounds: Model development and field-scale application SO GROUND WATER LA English DT Article ID OXYGEN-LIMITED BIODEGRADATION; IN-GROUND WATER; POROUS-MEDIA; CHLORINATED ALIPHATICS; INSITU BIORESTORATION; MICROBIAL-GROWTH; SANDY AQUIFER; SPILL SITE; TRANSPORT; SIMULATIONS AB Benzene, toluene, ethyl benzene and xylene (BTEX) dissolved into ground water and migrated from a light nonaqueous phase liquid (LNAPL) source in a sandy aquifer near a petroleum, oil, and lubricants (POL) facility at Hill Air Force Base (AFB), Utah. Field observations indicated that microbially mediated BTEX degradation using multiple terminal electron-accepting processes including aerobic respiration, denitrification, Fe(III) reduction, sulfate reduction, and methanogenesis has occurred in the aquifer. To study the transport and transformation of dissolved BTEX compounds under natural conditions, a reactive flow and transport model incorporating biochemical multispecies interactions and BTEX was developed. The BTEX, oxygen, nitrate, Fe(II), sulfate, and methane plumes calculated by the model agree reasonably well with field observations. The first-order biodegradation rate constants, estimated based on model calibration are 0.051, 0.031, 0.005, 0.004, and 0.002 day(-1) for aerobic respiration, denitrification, Fe(III), sulfate reduction, and methanogenesis, respectively. The results of a sensitivity analysis show that the saturated aquifer thickness, hydraulic conductivity, and reaction rate constants are the most critical parameters controlling the natural attenuation of BTEX at this site. The hydraulic conductivity and aquifer thickness were found to be the key factors affecting the restoration of oxygen, nitrate, and sulfate after their interaction with the BTEX plume. The multispecies reactive transport modeling effort, describing BTEX degradation mediated by multiple electron-accepting processes, represents one of the few attempts to date to quantify a complete sequence of natural attenuation processes with a detailed field data set. Because the case study is representative of many petroleum-product contaminated sites, the results and insights obtained from this study are of general interest and relevance to other fuel-hydrocarbon natural attenuation sites. C1 Univ Alabama, Dept Geol, Tuscaloosa, AL 35487 USA. Pacific NW Lab, Richland, WA 99352 USA. Parsons Engn Sci Inc, Denver, CO 80290 USA. RP Lu, GP (reprint author), Div Earth & Environm Sci, Geoanal Grp, EES-5,C306, Los Alamos, NM 87545 USA. RI Zheng, Chunmiao/I-5257-2014 OI Zheng, Chunmiao/0000-0001-5839-1305 NR 37 TC 78 Z9 82 U1 2 U2 38 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1999 VL 37 IS 5 BP 707 EP 717 DI 10.1111/j.1745-6584.1999.tb01163.x PG 11 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 231HX UT WOS:000082303500012 PM 19125924 ER PT J AU Nakao, S Najita, J Karasaki, K AF Nakao, S Najita, J Karasaki, K TI Sensitivity study on hydraulic well testing inversion using simulated annealing SO GROUND WATER LA English DT Article ID SYSTEMS; MODELS AB Cluster variable aperture (CVA) simulated annealing has been used as an inversion technique to construct fluid flow models of fractured formations based on transient pressure data from hydraulic tests. A two-dimensional fracture network system is represented as a filled regular lattice of fracture elements. The algorithm iteratively changes element apertures for a cluster of fracture elements in order to improve the match to observed pressure transients. Aperture size is chosen randomly from a list of discrete apertures. The cluster size is held constant throughout the iterations. Since hydraulic inversion is inherently nonunique, it is important to use additional information. We investigated the relationship between the scale of heterogeneity and the optimal cluster size and shape to enhance convergence of the inversion and improve the results. In a spatially correlated transmissivity field, a cluster size corresponding to about 20% to 40% of the practical range of the spatial correlation is optimal. Inversion results of the Raymond test site data are also presented and based on an optimal cluster size; the practical range of the spatial correlation is estimated to be 5 to 10 m. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Nakao, S (reprint author), Geol Survey Japan, Tsukuba, Ibaraki 3058567, Japan. NR 25 TC 3 Z9 3 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1999 VL 37 IS 5 BP 736 EP 747 DI 10.1111/j.1745-6584.1999.tb01166.x PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 231HX UT WOS:000082303500015 PM 19125927 ER PT J AU Wolbarst, AB Blom, PF Chan, D Cherry, RN Doehnert, M Fauver, D Hull, HB MacKinney, JA Mauro, J Richardson, ACB Zaragoza, L AF Wolbarst, AB Blom, PF Chan, D Cherry, RN Doehnert, M Fauver, D Hull, HB MacKinney, JA Mauro, J Richardson, ACB Zaragoza, L TI Sites in the United States contaminated with radioactivity SO HEALTH PHYSICS LA English DT Review DE contamination, environmental; environmental assessment; radiation, ionizing; radioactivity, removal of AB Over the century that radioactive materials have been mined, processed, produced, and utilized, many sites across the United States have become contaminated, Such sites include bases and installations of the Department of Defense, weapons production and research facilities of the Department of Energy, properties under the authority of other Federal agencies, privately-owned and governmental facilities that are licensed by the Nuclear Regulatory Commission and its Agreement States, and sites licensed by or the responsibility of states. This review reports on aspects of work by the Environmental Protection Agency, the Department of Defense, the Department of Energy, the Nuclear Regulatory Commission, and others to identify sites contaminated with radioactive materials, It also describes the principal programs that have been instituted to deal with them. C1 US EPA, Off Radiat & Indoor Air, Washington, DC 20460 USA. US Dept Energy, Eastern Area Program, Germantown, MD 20874 USA. Cohen & Associates Inc, Mclean, VA 22101 USA. DACS SF, Dept Army, Washington, DC 20310 USA. US Nucl Regulatory Commiss, Washington, DC 20555 USA. US EPA, Off Emergency & Remedial Response, Washington, DC 20460 USA. NR 38 TC 6 Z9 7 U1 0 U2 5 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1999 VL 77 IS 3 BP 247 EP 260 DI 10.1097/00004032-199909000-00002 PG 14 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 226FN UT WOS:000082009800002 PM 10456495 ER PT J AU Whicker, JJ Rodgers, JC Lopez, RC AF Whicker, JJ Rodgers, JC Lopez, RC TI Assessment of need for transport tubes when continuously monitoring for radioactive aerosols SO HEALTH PHYSICS LA English DT Article DE aerosols; sampling; monitors; radiation; ventilation ID PENETRATION AB Aerosol transport tubes are often used to draw aerosol from desirable sampling locations to nearby air sampling equipment that cannot be placed at that location. In many plutonium laboratories at Los Alamos National Laboratory, aerosol transport tubes are used to transport aerosol from the front of room ventilation exhaust registers to continuous air monitors (CAMs) that are mounted on nearby walls. Transport tubes are used because past guidance suggests that extraction of aerosol samples from exhaust locations provides the most sensitive and reliable detection under conditions where the rooms have unpredictable release locations and significant spatial variability in aerosol concentrations after releases, and where CAMs cannot be located in front of exhaust registers without blocking worker walkways. Despite designs to minimize particle loss in tubes, aerosol transport model predictions suggest losses occur lowering the sensitivity of CAMs to accidentally released plutonium aerosol. The goal of this study was to test the hypotheses that the reliability, speed, and sensitivity of aerosol detection would be equal whether the sample was extracted from the front of the exhaust register or from the wall location of CAMs. Polydisperse oil aerosols were released from multiple locations in two plutonium laboratories to simulate plutonium aerosol releases. Networked laser particle counters (LPCs) mere positioned to simultaneously measure time-resolved aerosol concentrations at each exhaust register (representative of sampling with transport tubes) and at each wall-mounted CAM location (representative of sampling without transport tubes). Results showed no significant differences in detection reliability, speed, or sensitivity for LPCs positioned at exhaust locations when compared to LPCs positioned at the CAM: wall location. Therefore, elimination of transport tubes would likely improve CAM performance. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 13 TC 2 Z9 2 U1 4 U2 5 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1999 VL 77 IS 3 BP 322 EP 327 DI 10.1097/00004032-199909000-00012 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 226FN UT WOS:000082009800012 PM 10456505 ER PT J AU McCormick, PS Qiang, J Ryne, RD AF McCormick, PS Qiang, J Ryne, RD TI Visualizing high-resolution accelerator physics SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87544 USA. RP McCormick, PS (reprint author), Univ Calif Los Alamos Natl Lab, Adv Comp Lab, MS B287, Los Alamos, NM 87544 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD SEP-OCT PY 1999 VL 19 IS 5 BP 11 EP 13 DI 10.1109/38.788792 PG 3 WC Computer Science, Software Engineering SC Computer Science GA 230AB UT WOS:000082227700003 ER PT J AU Wong, PC AF Wong, PC TI Visual data mining SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Editorial Material C1 Pacific NW Lab, Richland, WA 99352 USA. RP Wong, PC (reprint author), Pacific NW Lab, POB 999,902 Battelle Blvd,MSIN-K7-28, Richland, WA 99352 USA. NR 0 TC 34 Z9 35 U1 0 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD SEP-OCT PY 1999 VL 19 IS 5 BP 20 EP 21 PG 2 WC Computer Science, Software Engineering SC Computer Science GA 230AB UT WOS:000082227700005 ER PT J AU Heermann, PD AF Heermann, PD TI First-generation ASCI production visualization environment SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Heermann, PD (reprint author), Sandia Natl Labs, Dept 9215 MS 0318,Box 5800, Albuquerque, NM 87185 USA. NR 4 TC 2 Z9 2 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD SEP-OCT PY 1999 VL 19 IS 5 BP 66 EP 71 DI 10.1109/38.788802 PG 6 WC Computer Science, Software Engineering SC Computer Science GA 230AB UT WOS:000082227700013 ER PT J AU Ivezic, N Potok, TE Pouchard, L AF Ivezic, N Potok, TE Pouchard, L TI Multiagent framework for lean manufacturing SO IEEE INTERNET COMPUTING LA English DT Article C1 Oak Ridge Natl Lab, Collaborat Technol Res Ctr, Oak Ridge, TN USA. RP Ivezic, N (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. OI Potok, Thomas/0000-0001-6687-3435 NR 0 TC 9 Z9 10 U1 1 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1089-7801 J9 IEEE INTERNET COMPUT JI IEEE Internet Comput. PD SEP-OCT PY 1999 VL 3 IS 5 BP 58 EP 59 DI 10.1109/4236.793459 PG 2 WC Computer Science, Software Engineering SC Computer Science GA 239FM UT WOS:000082758200013 ER PT J AU Baca, AG Heller, EJ Hietala, VM Casalnuovo, SA Frye-Mason, GC Klem, JF Drummond, TJ AF Baca, AG Heller, EJ Hietala, VM Casalnuovo, SA Frye-Mason, GC Klem, JF Drummond, TJ TI Development of a GaAs monolithic surface acoustic wave integrated circuit SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Article; Proceedings Paper CT 20th Annual IEEE GaAs IC Symposium CY NOV 01-04, 1998 CL ATLANTA, GEORGIA SP IEEE AB An oscillator technology using surface acoustic wave (SAW) delay lines integrated with GaAs MESFET electronics has been del eloped for GaAs-based integrated microsensor applications, The oscillator consists of a two-port SAW delay line in a feedback loop with a four-stage GaAs MESFET amplifier, Oscillators with frequencies of 470, 350, and 200 MHz have been designed and fabricated. This oscillator technology is most suitable for sensor applications but can logically be extended to radio-frequency oscillator and filter applications by methods well known for other piezoelectric substrates. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Baca, AG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 5 TC 7 Z9 7 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD SEP PY 1999 VL 34 IS 9 BP 1254 EP 1258 DI 10.1109/4.782084 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA 228ZQ UT WOS:000082167800012 ER PT J AU Willerton, D AF Willerton, D TI After the curtain was pulled away SO IEEE SOFTWARE LA English DT Article AB The elements and people essential to project success have changed over the last few years. Not every project is perfect, with clearly defined requirements and goals. The author describes how Wizards, the new team leaders, work with the chaos of real life to pull together a success. C1 Univ Calif Los Alamos Natl Lab, Comp Informat & Commun Div, Customer Ser Grp, Los Alamos, NM 87545 USA. RP Willerton, D (reprint author), Univ Calif Los Alamos Natl Lab, Comp Informat & Commun Div, Customer Ser Grp, POB 1663,MS B251, Los Alamos, NM 87545 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0740-7459 J9 IEEE SOFTWARE JI IEEE Softw. PD SEP-OCT PY 1999 VL 16 IS 5 BP 114 EP 117 DI 10.1109/52.795110 PG 4 WC Computer Science, Software Engineering SC Computer Science GA 240WX UT WOS:000082851000024 ER PT J AU Benner, JP Kazmerski, L AF Benner, JP Kazmerski, L TI Photovoltaics gaining greater visibility SO IEEE SPECTRUM LA English DT Article C1 Natl Ctr Photovolta, Natl Renewable Energy Lab, Golden, CO USA. RP Benner, JP (reprint author), Natl Ctr Photovolta, Natl Renewable Energy Lab, Golden, CO USA. NR 2 TC 56 Z9 60 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD SEP PY 1999 VL 36 IS 9 BP 34 EP 42 DI 10.1109/6.789597 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 231JY UT WOS:000082306000015 ER PT J AU Portnoff, MR AF Portnoff, MR TI An efficient parallel-processing method for transposing large matrices in place SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article DE corner turn; fast algorithms; image formation; image processing; matrix transpose; parallel processing; seismic migration; synthetic aperture radar AB We have developed an efficient algorithm for transposing large matrices in place. The algorithm is efficient because data are accessed either sequentially in blocks or randomly within blocks small enough to fit in cache, and because the same indexing calculations are shared among identical procedures operating on independent subsets of the data. This inherent parallelism makes the method well suited for a multiprocessor computing environment. The algorithm is easy to implement because the same two procedures are applied to the data in various groupings to carry out the complete transpose operation. Using only a single processor, we have demonstrated nearly an order of magnitude increase in speed over the previously published algorithm by Gate and Twigg for transposing a large rectangular matrix in place. With multiple processors operating in parallel, the processing speed increases almost linearly with the number of processors. A simplified version of the algorithm for square matrices is presented as well as an extension for matrices large enough to require virtual memory. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Portnoff, MR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 11 Z9 13 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7149 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD SEP PY 1999 VL 8 IS 9 BP 1265 EP 1275 DI 10.1109/83.784438 PG 11 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 231AB UT WOS:000082282900010 PM 18267543 ER PT J AU Tolbert, LM Habetler, TG AF Tolbert, LM Habetler, TG TI Novel multilevel inverter carrier-based PWM method SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT Annual Meeting of the Industry-Applications-Society CY OCT 12-16, 1998 CL ST LOUIS, MO SP Ind Applicat Soc DE carrier-based pulsewidth modulation; diodeclamped inverter; multilevel converter; multilevel inverter; multilevel pulsewidth modulation AB The advent of the transformerless multilevel inverter topology has brought forth various pulsewidth modulation (PWM) schemes as a means to control the switching of the active devices in each of the multiple voltage levels in the inverter, An analysis of how existing multilevel carrier-based PWM affects switch utilization for the different levels of a diode-clamped inverter is conducted. Two novel carrier-based multilevel PWM schemes are presented which help to optimize or balance the switch utilization in multilevel inverters. A 10-kW prototype six-level diode-clamped inverter has been built and controlled with the novel PWM strategies proposed in this paper to act as a voltage-source inverter for a motor drive. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. RP Tolbert, LM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM tolbertlm@oml.gov; tom.habetler@ece.gatech.edu OI Tolbert, Leon/0000-0002-7285-609X NR 18 TC 189 Z9 206 U1 1 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-9994 EI 1939-9367 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 1999 VL 35 IS 5 BP 1098 EP 1107 DI 10.1109/28.793371 PG 10 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA 242MD UT WOS:000082944100015 ER PT J AU Ashikhmin, AE Honkala, IS Laihonen, TK Litsyn, SN AF Ashikhmin, AE Honkala, IS Laihonen, TK Litsyn, SN TI On relations between covering radius and dual distance SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Article DE constant weight codes; covering radius; dual distance; Krawtchouk polynomial ID BINARY-CODES; UPPER-BOUNDS AB The covering radius of a code tells us how far in the sense of Hamming distance an arbitrary word of the ambient space can be from the code. For a few decades this parameter has been widely studied. In this paper we estimate the covering radius of a code when the dual distance is known. We derive a new bound on covering radii of linear codes. It improves essentially on the previously known estimates in a certain wide range. We also study asymptotic bounds on the cardinality of constant weight codes. C1 Univ Calif Los Alamos Natl Lab, Grp CIC 3, Los Alamos, NM 87545 USA. Univ Turku, Dept Math, FIN-20014 Turku, Finland. RP Ashikhmin, AE (reprint author), Univ Calif Los Alamos Natl Lab, Grp CIC 3, POB 1663, Los Alamos, NM 87545 USA. NR 30 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9448 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD SEP PY 1999 VL 45 IS 6 BP 1808 EP 1816 DI 10.1109/18.782101 PG 9 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 227XP UT WOS:000082105500005 ER PT J AU You, CY Bader, SD AF You, CY Bader, SD TI Bias-voltage-controlled interlayer exchange coupling SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE bias voltage; controllable interlayer exchange coupling; magnetization direction; quantum well; tunneling AB We propose a new system whose magnetization direction can be controlled by an applied bias voltage without an external magnetic field. The system consists of a four layered structure F-1/S/I/F-2 (F-1, F-2: ferromagnets, S: spacer, I: insulator), An analytic expression for bias-voltage-controlled interlayer exchange coupling in this system is developed within a simple free-electron-like, one-dimensional approximation, According to the approach, the magnetic configurations of the two magnetic layers oscillate from antiferromagnetic to ferromagnetic with applied bias voltage. This implies that we can switch/rotate the magnetization direction without an external magnetic field. Possible applications of such a system are also discussed. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP You, CY (reprint author), Argonne Natl Lab, Div Sci Mat, 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 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 2967 EP 2969 DI 10.1109/20.801049 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EH UT WOS:000083151100238 ER PT J AU Jiang, JS Fullerton, EE Sowers, CH Inomata, A Bader, SD Shapiro, AJ Shull, RD Gornakov, VS Nikitenko, VI AF Jiang, JS Fullerton, EE Sowers, CH Inomata, A Bader, SD Shapiro, AJ Shull, RD Gornakov, VS Nikitenko, VI TI Spring magnet films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE permanent magnet; exchange spring; magnetic reversal; epitaxy; sputter; thin film; superlattice; SmCo ID PERMANENT-MAGNETS; ANISOTROPY; REMANENCE; BILAYERS; FE AB The properties of exchange-spring-coupled bilayer and superlattice films are highlighted for Sm-Co hard magnet (nominally Sm2Co7) and Fe or Co soft magnet layers. The hexagonal Sm-Co is grown via magnetron sputtering in a- and b-axis epitaxial orientations. In both cases the c-axis, in the film plane, is the easy axis of magnetization. Trends in coercivity with film thickness are established and related to the respective microstructures of the two orientations. The magnetization reversal process for the bilayers is examined by magnetometry and magneto-optical imaging, as well as by simulations that utilize a one-dimensional model to provide the spin configuration for each atomic layer. The Fe magnetization is pinned to that of the Sm-Co at the interface, and reversal proceeds via a progressive twisting of the Fe magnetization, The Fe demagnetization curves are reversible as expected for a spring magnet. Comparison of experiment and simulations indicates that the spring magnet behavior can be understood from the intrinsic properties of the hard and soft layers. Estimates are made of the ultimate gain in performance that can potentially be realized in this system. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. NIST, Gaithersburg, MD 20899 USA. Fujitsu Ltd, Atsugi, Kanagawa, Japan. Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. RP Jiang, JS (reprint author), Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Shull, Robert/F-5971-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 21 TC 32 Z9 35 U1 1 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 3229 EP 3234 DI 10.1109/20.800484 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EM UT WOS:000083151500002 ER PT J AU Bi, Y Jiles, DC AF Bi, Y Jiles, DC TI Finite element modeling of an electrically variable inductor SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE nonlinear finite element modeling; variable inductor AB A new type of electrically variable inductor has been investigated. This uses an sc excitation field with an orthogonal de bias field to control the properties of the device. Measurements showed that the effective inductance can be decreased by increasing the orthogonal de bias field. With an appropriate current in the orthogonal bias coils, an inductance plateau can be reached in which the inductance remains stable over a range of excitation currents. The inductance value can be adjusted by controlling the orthogonal current. Based on an existing anhysteretic magnetization model, nonlinear 3D finite element modeling was successfully used to model the distribution of flux density and to identify the region of saturation which is believed to result in the decrease in effective inductance of the inductor. The effective inductance of the device was also modeled using numerical finite element calculations. The modeled inductance showed broad agreement with experimental results and predicted the observed trend in inductance. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Bi, Y (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 3 TC 6 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 3517 EP 3519 DI 10.1109/20.800575 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EM UT WOS:000083151500093 ER PT J AU Chen, Y Snyder, JE Schwichtenberg, CR Dennis, KW McCallum, RW Jiles, DC AF Chen, Y Snyder, JE Schwichtenberg, CR Dennis, KW McCallum, RW Jiles, DC TI Metal-bonded Co-ferrite composites for magnetostrictive torque sensor applications SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE ferrite; torque sensor; magnetostriction; magnetomechanical effect ID RING AB A new class of magnetomechanical sensor materials, Co-ferrite (CoO . Fe2O3) and metal-bonded (Ag, Ni, Co) Co-ferrite composites, has been investigated. These materials exhibited magnetostriction in excess of 200 ppm and high d(33) (partial derivative lambda/partial derivative H)(sigma) coefficient, 1.3X10(-9) A(-1)m, at low applied field (<100kA/m). Selected compositions were formed into test samples in the form of rings brazed to stainless steel through-shafts. Changes of surface axial magnetic field in response to applied torque as high as 64 AN(-1)m(-2) were observed for a demonstration sample of dimensions 25 mm OD, 12.5 mm ID, and 8 mm high, A hysteresis of +/- 0.5 N.m was observed. These materials appear to be promising candidates for torque sensors, and other magnetostrictive sensor and actuator applications. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Chen, Y (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 11 TC 84 Z9 85 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 3652 EP 3654 DI 10.1109/20.800620 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EM UT WOS:000083151500138 ER PT J AU Bi, Y Jiles, DC AF Bi, Y Jiles, DC TI Measurements and modeling of hysteresis in magnetic materials under the action of an orthogonal bias field SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE domain processes; hysteresis; orthogonal field ID TRANSVERSE SUSCEPTIBILITY AB The effect of an orthogonal de bias field on hysteresis in isotropic magnetic materials under the action of an sc exciting field was investigated The experimental results indicated that the orthogonal field rotated the hysteresis loops on the BH plane and reduced the enclosed area. As a result, the effective permeability, hysteresis loss, coercivity and remanence decreased with increasing orthogonal bias field. By including the orthogonal field in the anhysteretic model equation and incorporating a variable reversibility coefficient, the Jiles-Atherton hysteresis model was extended to describe the behavior of magnetic materials under the action of an orthogonal bias field. Using finite element modeling for evaluating the effective internal orthogonal field, the modeled hysteresis curve showed quantitative agreement with experimental results. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Bi, Y (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 10 TC 6 Z9 7 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 3787 EP 3789 DI 10.1109/20.800665 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EM UT WOS:000083151500183 ER PT J AU Johnson, MJ Chen, R Jiles, DC Ramanan, VR AF Johnson, MJ Chen, R Jiles, DC Ramanan, VR TI Reducing core losses in amorphous Fe80B12Si8 ribbons by laser-induced domain refinement SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE amorphous metals; core loss; laser scribing; transformer efficiency AB In transformer cores amorphous metallic ribbons are competitive substitutes for silicon-iron laminates due to their low values of core loss. Research has been conducted to further improve performance by using techniques that can reduce core losses in the metallic ribbons. One way of reducing core loss is to anneal the samples in a magnetic field. However, further reductions in core loss are possible by scribing the surface of the ribbons using a laser beam. The scribing pattern can lead to a refined domain structure and reduced excess loss. It has been found that under suitable processing conditions, core loss can be further reduced by as much as 20% by laser scribing. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. ABB Power T&D Co, Raleigh, NC 27606 USA. RP Johnson, MJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 11 TC 0 Z9 0 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 3865 EP 3867 DI 10.1109/20.800690 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EM UT WOS:000083151500208 ER PT J AU Lo, CCH Tang, F Jiles, DC Biner, SB AF Lo, CCH Tang, F Jiles, DC Biner, SB TI Evaluation of fatigue damage using a magnetic measurement technique SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1999 International Magnetics Conference (INTERMAG 99) CY MAY 18-21, 1999 CL KYONGJU, SOUTH KOREA SP IEEE Magnet Soc DE strain-controlled fatigue; magnetic hysteresis AB A series of strain-controlled fatigue tests were performed on 0.1 wt% C Fe-C alloy samples under different strain amplitudes. The measured coercivity of these samples was found to behave differently in the initial and final stages of fatigue. In the intermediate stage of fatigue it was found that coercivity tended to increase, while initial and maximum permeabilities tended to decrease. This could be related to the changes in the surface structure which were observed by SEM, The present results indicate that hysteresis parameters are related to the accumulation of fatigue damage, and therefore it is possible to develop a magnetic measurement technique for monitoring fatigue damage in steel. components. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Lo, CCH (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 6 TC 9 Z9 10 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1999 VL 35 IS 5 BP 3977 EP 3979 DI 10.1109/20.800727 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 246EM UT WOS:000083151500245 ER PT J AU Zhu, JH Liu, CT Liaw, PK AF Zhu, JH Liu, CT Liaw, PK TI Phase stability and mechanical behavior of NbCr2-based Laves phases SO INTERMETALLICS LA English DT Article DE Laves phases; fracture toughness; phase diagram; phase stability, prediction ID FRACTURE-TOUGHNESS; ALLOYS AB The phase relations in pseudo-binary Nb(Cr,X)(2) systems, where X-Fe or Co, were determined experimentally to verify the ela correlation with phase stability. The substitution of Fe or Co for Cr in NbCr2 increases the average electron concentration of the alloy, thus leading to a systematic change of the crystal structures from C15 to C14 and C14 to C15. The experimental critical ela values corresponding to the C15/C14/C15 phase transitions are consistent with those from the phase diagram survey: the C15 structure is stabilized at ela < 5.77; the C14 structure is stable at 5.85 < ela <7.50; the C15 structure is stabilized again at e/a > 7.56. As the Fe or Co content increases in the Nb(Cr,X)2 phase, the volume of a 24-atom unit cell, decreases linearly, while the Vickers hardness increases over the whole C15 and C14 ranges. The fracture toughness values are low for all. the alloys; nevertheless, the fracture toughness of the C15 structure is greater than that of the C14 structure for the two pseudo-binary systems. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RP Liu, CT (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 25 TC 31 Z9 31 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD SEP PY 1999 VL 7 IS 9 BP 1011 EP 1016 DI 10.1016/S0966-9795(99)00010-2 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 223GM UT WOS:000081832600005 ER PT J AU Anderson, IM Duncan, AJ Bentley, J AF Anderson, IM Duncan, AJ Bentley, J TI Site-distributions of Fe alloying additions to B2-ordered NiAl SO INTERMETALLICS LA English DT Article DE nickel aluminides, based on NiAl; microalloying; site occupancy; electron microscopy, transmission; spectroscopic methods, various ID SECONDARY FLUORESCENCE CORRECTION; X-RAY-MICROANALYSIS; INTERMETALLIC COMPOUNDS; SINGLE-CRYSTALS; ALCHEMI; IRON; OCCUPANCIES; TEMPERATURE; FORMULATION; PREFERENCE AB The site-distributions of Fe alloying additions to BZ-ordered NiAl alloys have been measured by ALCHEMI (atom location by channeling-enhanced microanalysis). Twelve alloy compositions were examined, of stoichiometries Ni50-xAl50Fex (Ni-deficient), Ni50Al50-xFex (Al-deficient), and Ni50-x/2Al50-x/2Fex (intermediate), with four different alloying levels, x=0.25, 2, 5, and 10. The data indicate that Fe tends to act as a buffer between the two sublattices, preferentially occupying the site of the stoichiometrically deficient host element. However, the Fe alloying addition was found to partition between the two sublattices to some extent in all alloys, so that 'Ni'-site vacancies or Ni anti-site defects are required to maintain the site balance. The observed trends in the site-distributions suggest that the range of compositions reported by Darolia et al. (Darolia R, Lahrman DF, Field RD. Scripta Metall Mater 1992;26:1007). to exhibit enhanced ductility may coincide with an inversion in the site-substitution behavior, where more Ni than Fe occupies the aluminum sublattice. Published by Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Anderson, IM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS-6376, Oak Ridge, TN 37831 USA. NR 40 TC 41 Z9 42 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP PY 1999 VL 7 IS 9 BP 1017 EP 1024 DI 10.1016/S0966-9795(99)00013-8 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 223GM UT WOS:000081832600006 ER PT J AU Morris, DG Liu, CT George, EP AF Morris, DG Liu, CT George, EP TI Pinning of dislocations and the origin of the stress anomaly in FeAl alloys SO INTERMETALLICS LA English DT Article DE iron aluminides (based on FeAl); mechanical properties at high temperatures; mechanical properties at ambient temperature; defects : point defects; defects : dislocation geometry and arrangement ID IRON-ALUMINUM ALLOYS; VACANCY CONCENTRATION; SINGLE-CRYSTALS; BEHAVIOR; AL; FRACTURE; HARDNESS; MODEL; FLOW AB The anomalous stress rise found at intermediate temperatures in FeAl alloys may be caused by the presence of thermal vacancies produced as the temperature rises. Strong support for this hypothesis is provided by the demonstration that the same absolute values of stresses as well as stress increases are found both when testing at high temperatures and when testing at room temperature samples quenched from the same high temperatures. Examination of the superdislocations present after deformation shows strong pinning only at jogs produced by intersection with forest dislocations. Such sessile jogs on screw superdislocations lead to dipole and loop formation as the dislocations continue moving, hence producing the debris observed after deformation. In addition, edge superdislocations show a stepped morphology caused by line instabilities over a certain range of directions. There is no evidence of strong pinning and associated dislocation bowing by vacancy-aggregate type obstacles, and it is, therefore, deduced that the pinning obstacles responsible for the anomalous stress increase are probably relatively weak single vacancies, rather like solute atoms, and not stronger multi-vacancy defects. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Morris, DG (reprint author), CSIC, Dept Met Phys, CENIM, Ave Gregorio del Amo 8, E-28040 Madrid, Spain. RI Morris, David/B-2742-2014; George, Easo/L-5434-2014; OI Morris, David/0000-0002-3124-1988; Liu, Chain Tsuan/0000-0001-7888-9725 NR 27 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD SEP PY 1999 VL 7 IS 9 BP 1059 EP 1068 DI 10.1016/S0966-9795(99)00015-1 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 223GM UT WOS:000081832600011 ER PT J AU Glarborg, P Bendtsen, AB Miller, JA AF Glarborg, P Bendtsen, AB Miller, JA TI Nitromethane dissociation: Implications for the CH3+NO2 reaction SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID THERMAL-DECOMPOSITION; GROUND-STATE; NITRIC-OXIDE; NO2; PRESSURE; KINETICS; DEPENDENCE; OXIDATION; RADICALS; HYDROGEN AB The thermal decomposition of nitromethane under highly diluted conditions in shock tubes has been analyzed in terms of a detailed chemical kinetic model. The experimental data were adopted from Glanzer and Tree, Hsu and Lin, and Zhang and Bauer, respectively; they cover the temperature range 1000-1400 K and pressures from 0.5 to 6.0 bar. Based on these results, rate constants for the reactions CH3NO2(+M)half arrow right over half arrow left CH3 + NO2(+M) (R1) and CH3 + NO2 half arrow right over half arrow left CH3O + NO (R14) have been re-examined. The high and low pressure limits for reaction (R1) determined by Glanzer and Tree have been shown to be consistent with more recent shock tube data, provided a center broadening parameter is introduced to describe the fall-off behavior. Our reinterpretation of the shock tube results of Glanzer and Tree together with room temperature measurements indicate that the rate constant for (R14) decreases slightly with temperature, as k(14) = 4.0.10(13)T(-0.2) cm(3)mol(-1)s(-1). At high temperatures and atmospheric pressure this reaction is more than an order of magnitude faster than recombination of CH, and NO, to form nitromethane. Based on the available data for the forward and reverse rate of reaction (R1) a value of 66.7 +/- 2.0 cal/(mol K) for the entropy S-0.298 of CH3NO2 is estimated. (C) 1999 lohn Wiley G Sons, Inc. Int J Chem Kinet 31: 591-602, 1999. C1 Tech Univ Denmark, Dept Chem Engn, DK-2800 Lyngby, Denmark. Sandia Natl Labs, Livermore, CA 94551 USA. RP Glarborg, P (reprint author), Tech Univ Denmark, Dept Chem Engn, DK-2800 Lyngby, Denmark. NR 64 TC 35 Z9 38 U1 3 U2 13 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD SEP PY 1999 VL 31 IS 9 BP 591 EP 602 DI 10.1002/(SICI)1097-4601(1999)31:9<591::AID-KIN1>3.0.CO;2-E PG 12 WC Chemistry, Physical SC Chemistry GA 227FV UT WOS:000082069100001 ER PT J AU Dongarra, JJ Tourancheau, B AF Dongarra, JJ Tourancheau, B TI Clusters and computational grids for scientific computing SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Lyon 1, F-69365 Lyon, France. RP Dongarra, JJ (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD FAL PY 1999 VL 13 IS 3 BP 179 EP 179 DI 10.1177/109434209901300301 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 219JF UT WOS:000081603600001 ER PT J AU Casanova, H Kim, M Plank, JS Dongarra, JJ AF Casanova, H Kim, M Plank, JS Dongarra, JJ TI Adaptive scheduling for task farming with grid middleware SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article; Proceedings Paper CT Workshop on Clusters and Computational Grids for Scientific Computing CY SEP 02-04, 1998 CL KNOXVILLE, TENNESSEE SP Natl Inst Res Comp Sci, US Natl Sci Fdn, CNRS, INRIA, Lab Comp Sci Paarallelism, Ecole Normale Super Lyon, Oak Ridge Natl Lab, Univ Tennessee Knoxville, Comp Sci Dept, NSF Sci & Technol Ctr Res Parallel Computat AB Scheduling in metacomputing environments is an active field of research as the vision of a Computational Grid becomes more concrete. An important class of Grid applications are long-running parallel computations with large numbers of somewhat independent tasks (Monte Carlo simulations, parameter-space searches, etc.). A number of Grid middleware projects are available to implement such applications, but scheduling strategies are still open research issues. This is mainly due to the diversity of both Grid resource types and their availability patterns. The purpose of this work is to develop and validate a general adaptive scheduling algorithm for task farming applications along with a user interface that makes the algorithm accessible to domain scientists. The authors' algorithm is general in that it is not tailored to a particular Grid middleware and it requires very few assumptions concerning the nature of the resources. Their first testbed is NetSolve as it allows quick and easy development of the algorithm by isolating the developer from issues such as process control, I/O, remote software access, or fault-tolerance. C1 Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Univ Calif San Diego, Dept Comp Sci & Engn, La Jolla, CA 92093 USA. Soongsil Univ, Sch Comp, Seoul, South Korea. Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. RP Dongarra, JJ (reprint author), Univ Tennessee, Dept Comp Sci, 104 Ayres Hall, Knoxville, TN 37996 USA. RI Dongarra, Jack/E-3987-2014 NR 26 TC 21 Z9 25 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD FAL PY 1999 VL 13 IS 3 BP 231 EP 240 DI 10.1177/109434209901300306 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 219JF UT WOS:000081603600006 ER PT J AU Zaki, O Lusk, E Gropp, W Swider, D AF Zaki, O Lusk, E Gropp, W Swider, D TI Toward scalable performance visualization with Jumpshot SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article; Proceedings Paper CT Workshop on Clusters and Computational Grids for Scientific Computing CY SEP 02-04, 1998 CL KNOXVILLE, TENNESSEE SP Natl Inst Res Comp Sci, US Natl Sci Fdn, CNRS, INRIA, Lab Comp Sci Paarallelism, Ecole Normale Super Lyon, Oak Ridge Natl Lab, Univ Tennessee Knoxville, Comp Sci Dept, NSF Sci & Technol Ctr Res Parallel Computat AB Jumpshot is a graphical tool for understanding the performance of parallel programs. It is in the tradition of the upshot tool but contains a number of extensions and enhancements that make it suitable for large-scale parallel computations. Jumpshot takes as input a new, more flexible logfile format and comes with a library for generating such logfiles. An MPI profiling library is also included, enabling the automatic generation of such logfiles from MPI programs. Jumpshot is written in Java and can easily be integrated as an applet into browser-based computing environments. The most novel feature of Jumpshot is its automatic detection of anomalous durations, drawing the user's attention to problem areas in a parallel execution. This capability is particularly useful in large-scale parallel computations containing many events. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Lusk, E (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Gropp, William/0000-0003-2905-3029 NR 18 TC 89 Z9 91 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD FAL PY 1999 VL 13 IS 3 BP 277 EP 288 DI 10.1177/109434209901300310 PG 12 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 219JF UT WOS:000081603600010 ER PT J AU Venkateshwaran, B Yao, MW Guo, RY Bhalla, A Balachandran, U AF Venkateshwaran, B Yao, MW Guo, RY Bhalla, A Balachandran, U TI Low temperature dielectric properties of magnetoplumbite family of materials SO INTERNATIONAL JOURNAL OF INORGANIC MATERIALS LA English DT Article DE superconductors; oxides; magnetic materials; dielectric properties ID LASER AB The magnetoplumbite family of materials exhibit properties that make them suitable to be used as substrates materials for microwave application. Four members of the family studied in this work are LaMgAI(11)O(19), NdGaMgAl10O19, CaGa6Al6O19 and CaGa12O19. Dielectric studies have been carried out over a temperature range of 4-300 K and a wide frequency range. All four exhibit a low dielectric constant with good temperature stability, low dielectric loss and favorable frequency dependence characteristics. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Argonne Natl Lab, Ceram Sect, Argonne, IL 60439 USA. RP Bhalla, A (reprint author), Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. RI Yao, Manwen/P-3156-2014 NR 5 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1466-6049 J9 INT J INORG MATER JI Int. J. Inorg. Mater. PD SEP-OCT PY 1999 VL 1 IS 3-4 BP 213 EP 217 DI 10.1016/S1466-6049(99)00033-1 PG 5 WC Chemistry, Inorganic & Nuclear; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 298GW UT WOS:000086131800004 ER PT J AU Moraga, FJ Bonetto, FJ Lahey, RT AF Moraga, FJ Bonetto, FJ Lahey, RT TI Lateral forces on spheres in turbulent uniform shear flow SO INTERNATIONAL JOURNAL OF MULTIPHASE FLOW LA English DT Article DE lift force; vortex shedding; wake; sphere; shear; two-fluid model ID SYMMETRICAL SUDDEN EXPANSION; FINITE REYNOLDS-NUMBER; 2-PHASE BUBBLY FLOW; LIFT FORCE; ROTATIONAL FLOW; PHASE DISTRIBUTION; VIRTUAL MASS; VORTEX; DRAG; PARTICLE AB The lateral force on a tethered rigid sphere submerged in a turbulent, uniform shear flow of water was measured. Periodic and non-periodic motions of the sphere were observed depending on flowrate, shear and sphere density. The direction of the observed lateral force was opposite to that predicted by inviscid theory and increased in magnitude as the sphere's Reynolds numbers based on relative velocity, Re, and average shear, Re-del, increased. The lateral force was found to correlate with the product Re Re-del. The data suggests that a sign reversal occurs at relatively small values of the product Re Re-del where the lateral force is dominated by inviscid effects. The results are explained assuming that the lateral forces on rigid spheres are a consequence of two competing factors: namely, inviscid lift forces and the vortex shedding-induced lateral forces which are dominant for higher Reynolds numbers. An estimate of the kinetic energy in the wake was used to show that the Vortex shedding-induced lateral forces correlate with the product Re Re-del and are in a direction opposite to the inviscid lift force. Combining the experimental data of this study with similar data a correlation for the lift coefficient of spheres in turbulent shear flows was developed. This correlation is applicable to turbulent multiphase flows having a spherical dispersed phase. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Rensselaer Polytech Inst, Ctr Multiphase Res, Troy, NY 12180 USA. RP Lahey, RT (reprint author), Oak Ridge Associated Univ, Oak Ridge, TN 37830 USA. NR 69 TC 46 Z9 50 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0301-9322 J9 INT J MULTIPHAS FLOW JI Int. J. Multiph. Flow PD SEP-NOV PY 1999 VL 25 IS 6-7 BP 1321 EP 1372 DI 10.1016/S0301-9322(99)00045-2 PG 52 WC Mechanics SC Mechanics GA 254GF UT WOS:000083603000019 ER PT J AU Deng, W Lucas, JN AF Deng, W Lucas, JN TI Combined FISH with pan-telomeric PNA and whole chromosome-specific DNA probes to detect complete and incomplete chromosomal exchanges in human lymphocytes SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID IN-SITU HYBRIDIZATION; BIOLOGICAL DOSIMETRY; IONIZING-RADIATION; TRANSLOCATIONS; ABERRATIONS; BREAKAGE; CAPTURE AB Purpose: To combine FISH with pan-telomeric peptide nucleic acid (PNA) and whole chromosome-specific DNA probes to detect complete and incomplete chromosome exchanges in human lymphocytes. Materials and methods: Human lymphocytes were irradiated in vitro with 0.9 Gy low dose-rate (0.019 Gy/h) tritium beta-rays. Metaphase spreads were treated with RNase, fixed in 1:3 acetic acid:methanol, and then further treated with KCl, proteinase K and fixed in 4% paraformaldehyde. Slides were denatured, hybridized for 1.5 h with an FITC-labelled telomeric PNA probe, and rehybridized overnight with a spectrum-orange whole-chromosome probe specific for chromosomes 1, 2 and 4. Hybridized spreads were washed with 70% formamide/20 x SSC and counterstained with DAPI. Results: All three pairs of labelled chromosomes together with 92 telomeres were readily visible after hybridization. The whole chromosomes 1, 2 and 4 were painted orange, and all telomeres were stained green. Unpainted chromosomes were counterstained blue. In the observed 680 chromosome aberrations induced by tritium beta-rays in human lymphocytes after 52 h of culture, no evidence of telomere addition was detected. Incomplete and hidden complete exchanges and deletions were definitively discriminated. Conclusion: The simultaneous detection of telomeres and specific Whole chromosomes allows for the first time accurate analysis of complete and incomplete chromosome exchanges involving painted chromosomes in human lymphocytes. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Sichuan Inst Occupat Hlth, Sichuan Inst Radiat Hlth & Protect, Chengdu 610041, Peoples R China. RP Lucas, JN (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 18 TC 18 Z9 20 U1 1 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD SEP PY 1999 VL 75 IS 9 BP 1107 EP 1112 PG 6 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 237YT UT WOS:000082684700005 PM 10528918 ER PT J AU Povodyrev, AA Anisimov, MA Sengers, JV Marshall, WL Sengers, JMHL AF Povodyrev, AA Anisimov, MA Sengers, JV Marshall, WL Sengers, JMHL TI Critical locus of aqueous solutions of sodium chloride SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE aqueous salt solutions; critical locus; critical temperatures; ionic fluids; sodium chloride solutions ID SYSTEM NACL-H2O; PHASE-EQUILIBRIA; CRITICAL REGION; CRITICAL LINES; VAPOR-LIQUID; BEHAVIOR; 500-DEGREES-C; ELECTROLYTES; TEMPERATURES; CROSSOVER AB Experimental data reported in the literature indicate a strong dependence of the critical temperature of aqueous solutions of sodium chloride on salt concentration, especially in the limit of pure water. Critical pressures and densities also show strong dependences on salt concentration. We propose a new set of equations for the critical locus and compare the results with evaluations reported previously by a number of investigators. The new equations yield a better description of the experimental data from the limit of pure water to the highest salt concentration for which data are available (0.3 mass fraction of sodium chloride). C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Anisimov, MA (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NR 27 TC 15 Z9 15 U1 1 U2 5 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 1999 VL 20 IS 5 BP 1529 EP 1545 DI 10.1023/A:1021449323833 PG 17 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 266YN UT WOS:000084328000013 ER PT J AU Herzenberg, CL AF Herzenberg, CL TI Contributions of twentieth-century women to physics. SO ISIS LA English DT Book Review C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Herzenberg, CL (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0021-1753 J9 ISIS JI Isis PD SEP PY 1999 VL 90 IS 3 BP 642 EP 643 DI 10.1086/384502 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 247JJ UT WOS:000083217400093 ER PT J AU Kidder, RE AF Kidder, RE TI Stockpile stewardship SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kidder, RE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 1999 VL 16 IS 1 BP 20 EP 21 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 316KW UT WOS:000087167000019 ER PT J AU Muramatsu, Y Tani, Y Aoi, Y Kamijo, E Kaneyoshi, T Motoyama, M Delaunay, JJ Hayashi, T Grush, MM Callcott, TA Ederer, DL Heske, C Underwood, JH Perera, RCC AF Muramatsu, Y Tani, Y Aoi, Y Kamijo, E Kaneyoshi, T Motoyama, M Delaunay, JJ Hayashi, T Grush, MM Callcott, TA Ederer, DL Heske, C Underwood, JH Perera, RCC TI High-resolution soft X-ray emission spectra of crystalline carbon nitride films deposited by electron cyclotron resonance sputtering SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS LA English DT Article DE X-ray emission spectra; synchrotron radiation. carbon nitride; molecular-orbital calculation; electronic structure ID ALPHA-CLUSTER CALCULATIONS AB The X-ray emission spectra of crystalline carbon nitride films deposited by electron-cyclotron-resonance (ECR) plasma sputtering were observed using a high-resolution soft X-ray spectrometer at the Advanced Light Source to investigate the electronic structure of carbon nitride crystals. The spectral features in C K and N K X-ray emissions from the ECR-deposited carbon nitride films represent the highly degenerated valence orbitals and their highly pure crystalline form. The C K and NK X-ray emission spectra were approximately explained based on the C2p and N2p density of states in the hybridized C-N bonds. The absence of significant peak shifting in selectively excited C K and N K X-ray emission spectra showed that there is a fairly nondispersive structure between valence and conduction bands in ECR-deposited carbon nitride films. C1 NTT Corp, Lifestyle & Environm Technol Labs, Musashino, Tokyo 1808585, Japan. Ryukoku Univ, Otsu, Shiga 5202194, Japan. Hyogo Prefectural Inst Ind Res, Kobe, Hyogo 6540037, Japan. Univ Tennessee, Knoxville, TN 37996 USA. Tulane Univ, New Orleans, LA 70118 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP NTT Corp, Lifestyle & Environm Technol Labs, Musashino, Tokyo 1808585, Japan. RI Delaunay, Jean-Jacques/A-2841-2010 NR 16 TC 12 Z9 12 U1 1 U2 5 PU JAPAN SOC APPLIED PHYSICS PI TOKYO PA KUDAN-KITA BUILDING 5TH FLOOR, 1-12-3 KUDAN-KITA, CHIYODA-KU, TOKYO, 102-0073, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Brief Commun. Rev. Pap. PD SEP PY 1999 VL 38 IS 9A BP 5143 EP 5147 DI 10.1143/JJAP.38.5143 PG 5 WC Physics, Applied SC Physics GA 246TZ UT WOS:000083181800045 ER PT J AU Maiwa, H Christman, JA Kim, SH Kim, DJ Maria, JP Chen, B Streiffer, SK Kingon, AI AF Maiwa, H Christman, JA Kim, SH Kim, DJ Maria, JP Chen, B Streiffer, SK Kingon, AI TI Measurement of piezoelectric displacements of Pb(Zr, Ti)O-3 thin films using a double-beam interferometer SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article; Proceedings Paper CT 16th Meeting on Ferroelectric Materials and Their Applications (FMA-16) CY MAY 26-29, 1999 CL KYOTO, JAPAN DE piezoelectric properties; double-beam interferometry; PZT; MEMS; AFM ID SCANNING FORCE MICROSCOPY; COEFFICIENTS; CONSTANT; FATIGUE AB The double-beam interferometric method is applied to measure the field-induced displacement of Pb(Zr, Ti)O-3 thin films. The dc electric field dependence of the longitudinal piezoelectric coefficient (d(33)) response of Pb(Zr, Ti)O-3 thin films deposited by metal organic chemical vapor deposition (MOCVD) was measured. Experimental d(33) values were compared with coefficients calculated using a phenomenological approach and bulk parameters. Qualitative agreement was obtained between measured and calculated coefficients. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. ATMI Inc, Danbury, CT 06810 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Maiwa, H (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA. RI KIM, DONG-JOO/C-2277-2008; Streiffer, Stephen/A-1756-2009 NR 25 TC 20 Z9 20 U1 0 U2 2 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO, 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD SEP PY 1999 VL 38 IS 9B BP 5402 EP 5405 DI 10.1143/JJAP.38.5402 PG 4 WC Physics, Applied SC Physics GA 248MC UT WOS:000083277900024 ER PT J AU Allendorf, MD Melius, CF Bauschlicher, CW AF Allendorf, MD Melius, CF Bauschlicher, CW TI Heats of formation and bond energies in group III compounds SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 12th European Conference on Chemical Vapour Deposition CY SEP 05-10, 1999 CL BARCELONA, SPAIN SP Elect Soc, Gen Catalunya Dept Presidencia Comm Univ Recerca, ICMAB, CSIC, ISCAR New Line, INORGTECH, CND ID GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; VAPOR-PHASE EPITAXY; THERMAL-DECOMPOSITION; WAVE-FUNCTIONS; THERMOCHEMISTRY; APPROXIMATION; PREDICTIONS; EXCHANGE; GALLIUM AB We present heats of formation and bond energies for Group-III compounds obtained from calculations of molecular ground-state electronic energies. Data for compounds of the form MXn are presented, where M = B, Al, Ga, and In, X = H, CI, and CH3, and n = 1-3. Energies for the B, Al, and Ga compounds are obtained from G2 predictions, while those for the In compounds are obtained from CCSD(T)/CBS calculations; these are the most accurate calculations for indium-containing compounds published to date. In most cases, the calculated thermochemistry is in good agreement with published values derived from experiments for those species that have well-established heats of formation. Bond energies obtained from the heats of formation follow the expected trend (C1 >> CH3 similar to H). However. the CH3M-(CH3)(2) bond energies obtained for trimethylgallium and trimethylindium are considerably stronger (> 15 kcal mol(-1)) than currently accepted values. C1 Sandia Natl Labs, Livermore, CA 94551 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Allendorf, MD (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 63 TC 13 Z9 13 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1999 VL 9 IS P8 BP 23 EP 31 DI 10.1051/jp4:1999803 PN 1 PG 9 WC Physics, Multidisciplinary SC Physics GA 235DM UT WOS:000082524800004 ER PT J AU Raffy, C Blanquet, E Pons, M Bernard, C Melius, CF Allendorf, MD AF Raffy, C Blanquet, E Pons, M Bernard, C Melius, CF Allendorf, MD TI Contribution to the modeling of CVD silicon carbide growth SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 12th European Conference on Chemical Vapour Deposition CY SEP 05-10, 1999 CL BARCELONA, SPAIN SP Elect Soc, Gen Catalunya Dept Presidencia Comm Univ Recerca, ICMAB, CSIC, ISCAR New Line, INORGTECH, CND ID CHEMICAL VAPOR-DEPOSITION; GAS-PHASE; PYROLYSIS; METHYLSILANE; MECHANISM; KINETICS; PROPANE; 298-K AB The modeling of the growth of silicon carbide from the vapor phase in the Si-C-H system requires a good understanding of the gas-phase chemistry. The object of this paper is to complement the previous studies on the kinetic modeling of the gas-phase in the system SiH4 / C3H8. To date, kinetic approaches to modeling the gas-phase chemistry have not been fully developed Previous kinetic models have only dealt with the pyrolysis of individual precursors (silane and propane) without allowing for the formation of organosilicon species. This study provides a progress report on our efforts to develop a full gas-phase mechanism that includes organosilicon compounds. Rate constants for this mechanism are determined where possible from experimental data available in the literature. However, for several important reactions, experimental data are not available. Consequently, we are performing ab initio calculations to determine activation energies and are using RRKM calculations to estimate pressure fall-off effects for unimolecular reactions. In this contribution, we focus on the formation of methylsilane H3SiCH3 and discuss the importance ol: such species in the gas-phase chemistry of SiC deposition. C1 ENSEEG, LTPCM, F-38402 St Martin Dheres, France. Sandia Natl Labs, Livermore, CA USA. RP Raffy, C (reprint author), ENSEEG, LTPCM, 1130 Rue Piscine,Domaine Univ,BP 75, F-38402 St Martin Dheres, France. NR 23 TC 22 Z9 23 U1 0 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1999 VL 9 IS P8 BP 205 EP 212 DI 10.1051/jp4:1999825 PN 1 PG 8 WC Physics, Multidisciplinary SC Physics GA 235DM UT WOS:000082524800026 ER PT J AU Fivel, MC El-Azab, AA AF Fivel, MC El-Azab, AA TI Linking continuum mechanics and 3D discrete dislocation simulations SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 3rd European Mechanics of Materials Coference on Mechanics and Multi-Physics Processes in Solid - Experiments, Modelling, Applications (EUROMECH-MECAMAT 98) CY NOV 23-25, 1998 CL OXFORD, ENGLAND SP European Mech Soc, French Soc Mech Math, Imperial Coll, Ecoles Mines Paris ID CRYSTALS AB A technique is developed for linking the methods of discrete dislocation dynamics simulation and finite element to treat elasto-plasticity problems. The overall formulation views the plastically deforming crystal as an elastic crystal with continuously changing dislocation microstructure which is tracked by the numerical dynamics simulation. The FEM code needed in this regard is based an linear elasticity only. This formulation presented here is focused on a continuous updating of the outer shape of the crystal, for possible regeneration of the FEM mesh, and adjustment of the surface geometry, in particular the surface normal. The method is expected to be potentially applicable to the nano-indentation experiments, where the zone around the indenter-crystal contact undergoes significant permanent deformation, the rigorous determination of which is very important to the calculation of the indentation print area and in turn, the surface hardness. Furthermore, the technique is expected to account for the plastic history of the surface displacement under the indenter. Other potential applications are mentioned in the text. C1 ENSPG, CNRS, GPM2, F-38402 St Martin Dheres, France. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Fivel, MC (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-415, Livermore, CA 94550 USA. NR 15 TC 5 Z9 5 U1 1 U2 8 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1999 VL 9 IS P9 BP 261 EP 270 DI 10.1051/jp4:1999926 PG 10 WC Physics, Multidisciplinary SC Physics GA 278WV UT WOS:000085012700027 ER PT J AU Hang, W Yan, XM Wayne, DM Olivares, JA Harrison, WW Majidi, V AF Hang, W Yan, XM Wayne, DM Olivares, JA Harrison, WW Majidi, V TI Selective removal of matrix ion peaks in plasma source time-of-flight mass spectrometry: ion deflection and detector gating SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT European Winter Conference on Plasma Spectrochemistry CY JAN 10-15, 1999 CL PAU, FRANCE AB A significant problem in plasma source time-of-flight mass spectrometry (TOFMS) is the saturation of detectors due to plasma gas and matrix ions. This paper outlines two experimental procedures to minimize the detector response to large ion currents in a glow discharge time-of-flight mass spectrometer. One novel solution is a deflection device that includes two parallel plates for ion ejection and two sleeve plates (after the deflection plates) to reduce ion and neutral scattering. Another approach is to gate the detector, by lowering the voltage on the microchannel plates, when an intense ion pack is expected. Both approaches are efficient in eliminating the plasma gas peaks and matrix ions in plasma source time-of-flight mass spectrometry. The matrix ion intensity can be reduced by several orders of magnitude, with minimal influence on the analyte ions. The detector gating technique requires a high peak current pulse with a flexible rise time. However, this approach will cause an electrical ringing to be superimposed on the analytical signal. Therefore, ion deflection is the method of choice for plasma TOFMS. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST 9, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div NMT 1, Los Alamos, NM 87545 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. RP Majidi, V (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST 9, MS K484, Los Alamos, NM 87545 USA. NR 10 TC 7 Z9 7 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD SEP PY 1999 VL 14 IS 9 BP 1523 EP 1526 DI 10.1039/a902211b PG 4 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 244YG UT WOS:000083077900037 ER PT J AU Steiner, RE Lewis, CL Majidi, V AF Steiner, RE Lewis, CL Majidi, V TI Consideration of a millisecond pulsed glow discharge time-of-flight mass spectrometer for concurrent elemental and molecular analysis SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT European Winter Conference on Plasma Spectrochemistry CY JAN 10-15, 1999 CL PAU, FRANCE ID STICHOCOCCUS-BACILLARIS; SIGNAL PROFILES AB The glow discharge ionization source operated in the pulsed (or modulated) power mode offers unique characteristics not available from its steady state counterpart. It has been well established that higher instantaneous power densities are obtainable without compromising the sample integrity when pulsed plasmas are implemented. This operating parameter affords higher sputter yields and lower limits of detection relative to the steady state plasmas. Of special interest are the discrete temporal regions associated with the modulated plasma. The presence of these time regimes offers temporal selectivity, allowing the collection of analytical data in a region where the contribution from background and contaminant species is minimized. These regions are characterized by strikingly different ionization mechanisms. Acquisition of data during each of these temporal regimes provides both molecular and elemental information. In this work the potential use of the pulsed glow discharge for collecting concurrent molecular and elemental information was explored. This task was accomplished using time-of-flight mass spectrometry (TOFMS). TOFMS has a significantly high throughput and duty cycle, making it ideally suited for rapid acquisition of spectra. This characteristic allows data acquisition during each of these temporal regions for each discharge pulse power cycle, affording concurrent elemental and molecular detection. p-Xylene was used as a test molecule for these studies. C1 Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div NMT 1, Los Alamos, NM 87545 USA. W Virginia Univ, Dept Chem, Morgantown, WV 26506 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST 9, Los Alamos, NM 87545 USA. RP Majidi, V (reprint author), Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div NMT 1, MS K484, Los Alamos, NM 87545 USA. NR 23 TC 40 Z9 40 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD SEP PY 1999 VL 14 IS 9 BP 1537 EP 1541 DI 10.1039/a902210d PG 5 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 244YG UT WOS:000083077900040 ER PT J AU Warren, TL AF Warren, TL TI The effect of strain rate on the dynamic expansion of cylindrical cavities SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article ID ALUMINUM C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Warren, TL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 5 Z9 7 U1 2 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD SEP PY 1999 VL 66 IS 3 BP 818 EP 821 DI 10.1115/1.2791764 PG 4 WC Mechanics SC Mechanics GA 246LP UT WOS:000083165500037 ER PT J AU Tang, XM Nichols, CA Manos, DM AF Tang, XM Nichols, CA Manos, DM TI Stripping and cleaning of photoresist using low energy neutrals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OXIDES AB Experimental studies of a broad-area hyperthermal neutral stream source for photoresist cleaning are reported. Low energy neutrals are generated from a high-density inductively coupled plasma by the surface reflection neutralization method. Rates of removal of photoresist polymers such as polymethyl methacrylate as functions of the hyperthermal translational energy and background neutral pressure are reported. The results demonstrate this low energy neutral source provides controllable fast neutrals for cleaning applications. Ex situ and in situ measurements yield typical removal rates of about 10 Angstrom/s without stream collimation. The removal rates at increasing pressures show a trade-off between creating higher density plasma, leading to a greater initial neutral flux and attenuation of neutrals due to collisions. These observations are in good agreement with previous Monte Carlo simulations. The removal rate increases linearly with rf power and is nearly constant as the neutral energy is varied by varying the reflector bias. One consequence of neutral directionality in collimated stream applications is the presence of unremoved carbon compounds on the sidewalls as indicated by angle-resolved x-ray photoelectron spectroscopy. (C) 1999 American Institute of Physics. [S0021-8979(99)07117-0]. C1 Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA. Sandia Natl Labs, Albuquerque, NM 87110 USA. RP Tang, XM (reprint author), Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA. NR 18 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1999 VL 86 IS 5 BP 2419 EP 2424 DI 10.1063/1.371070 PG 6 WC Physics, Applied SC Physics GA 227GV UT WOS:000082073000009 ER PT J AU Iwahara, J Clubb, RT AF Iwahara, J Clubb, RT TI Letter to the Editor: H-1, C-13 and N-15 resonance assignments of the AT-rich interaction domain from the Dead Ringer protein SO JOURNAL OF BIOMOLECULAR NMR LA English DT Letter DE ARID; Dead Ringer protein; DNA-binding domain; NMR assignment ID FAMILY C1 Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, UCLA DOE Lab Struct Biol & Genet, Los Angeles, CA 90095 USA. RP Clubb, RT (reprint author), Univ Calif Los Angeles, Dept Chem & Biochem, 405 Hilgard Ave, Los Angeles, CA 90095 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD SEP PY 1999 VL 15 IS 1 BP 85 EP 86 DI 10.1023/A:1008395719491 PG 2 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 237HT UT WOS:000082650300010 PM 20703964 ER PT J AU Kinney, JH Balooch, M Lane, NE Ryaby, JT AF Kinney, JH Balooch, M Lane, NE Ryaby, JT TI AFM study of the elastic properties of individual lamellae in cortical and trabecular bone. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI DURHAM PA PO BOX 2759, DURHAM, NC 27715-2759 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 1999 VL 14 SU 1 MA SA022 BP S314 EP S314 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 232CA UT WOS:000082347100724 ER PT J AU Knight, JB Kinney, JH Ryaby, JT AF Knight, JB Kinney, JH Ryaby, JT TI Application of the structure model index to the OVX rat model of osteoporosis. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Arizona State Univ, Dept Chem Bio & Mat Engn, Tempe, AZ USA. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. OrthoLog Inc, Res & Dev, Tempe, AZ USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI DURHAM PA PO BOX 2759, DURHAM, NC 27715-2759 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 1999 VL 14 SU 1 MA T321 BP S207 EP S207 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 232CA UT WOS:000082347100299 ER PT J AU Lane, NE Haupt, D Lotz, J Kinney, JH AF Lane, NE Haupt, D Lotz, J Kinney, JH TI Long term estrogen replacement therapy maintains trabecular bone strength by altering trabecular bone architecture. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 LLNL, Livermore, CA USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI DURHAM PA PO BOX 2759, DURHAM, NC 27715-2759 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 1999 VL 14 SU 1 MA SA398 BP S409 EP S409 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 232CA UT WOS:000082347101099 ER PT J AU Rajan, SS Wilson, AK Bhattacharyya, MH AF Rajan, SS Wilson, AK Bhattacharyya, MH TI Cadmium-induced changes in bone cell gene expression in an in vivo mouse model. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Argonne Natl Lab, Argonne, IL 60439 USA. Benedictine Univ, Lisle, IL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI DURHAM PA PO BOX 2759, DURHAM, NC 27715-2759 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 1999 VL 14 SU 1 MA SU028 BP S438 EP S438 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 232CA UT WOS:000082347101218 ER PT J AU Schriesheim, A AF Schriesheim, A TI ACS presidential election - Statement on education - Education in action SO JOURNAL OF CHEMICAL EDUCATION LA English DT Editorial Material C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Schriesheim, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD SEP PY 1999 VL 76 IS 9 BP 1175 EP 1175 PG 1 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA 228RK UT WOS:000082149300005 ER PT J AU Mielke, SL Garrett, BC Peterson, KA AF Mielke, SL Garrett, BC Peterson, KA TI The utility of many-body decompositions for the accurate basis set extrapolation of ab initio data SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; POTENTIAL-ENERGY SURFACE; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; BENCHMARK CALCULATIONS; BARRIER HEIGHT; CONVERGENCE; HYDROGEN; BORON; RATES AB We present a powerful new technique for the extrapolation of ab initio data based on many-body decompositions. Using the new methodology and subtle modifications of the standard correlation consistent basis sets, the H+H-2 barrier height is estimated at 9.603 kcal/mol with a precision of about 0.003 kcal/mol; this extremely accurate result is all the more striking as it can be obtained using basis sets no larger than aug-cc-pVQZ. The method is also used to yield highly accurate energies for the H+H-2 system on a grid of points previously calculated by quantum Monte Carlo. The three-body energy, summed with exact one- and two-body energies, is observed to yield a useful approximate lower bound for the total energy. The highly accurate energies afforded by this method can also be used to assess the accuracy of previously calculated data that has been used to construct potential energy surfaces. As an example, we make a detailed comparison between the new results and the quantum Monte Carlo results for H+H-2. (C) 1999 American Institute of Physics. [S0021-9606(99)30633-4]. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Dept Chem, Richland, WA 99352 USA. RP Mielke, SL (reprint author), Pacific NW Lab, Environm Mol Sci Lab, Mail Stop K8-91, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Mielke, Steven/B-7533-2008 OI Mielke, Steven/0000-0002-1938-7503 NR 30 TC 24 Z9 24 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1999 VL 111 IS 9 BP 3806 EP 3811 DI 10.1063/1.479683 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 228BM UT WOS:000082116000006 ER PT J AU Hessler, JP AF Hessler, JP TI New empirical rate expression for reactions without a barrier: Analysis of the reaction of CN with O-2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-RELAXATION; RADICAL REACTION; ATOM COLLISIONS; RATE CONSTANTS; O2; TEMPERATURES; DYNAMICS; KINETICS; STATES AB The rate coefficients of reactions that occur on potential energy surfaces without a barrier often exhibit a negative temperature dependence at low temperatures. Generally, this behavior is modeled with either the Harcourt-Essen equation, k(T)=AT(-m), or a "negative" activation energy, k(T)=AT(m) exp{Delta E/k(B)T}. Neither of these expressions is consistent with the Wigner threshold law. The general expression k(T)=(1+T/T-W)(-m)Sigma(l=0)(infinity)A(l)(1+T/T-W)(-l)(T/T-W)(l) is proposed where the relative angular momentum of the reacting species is l, T-W and m are independent parameters to be extracted from the data, and the amplitude of each partial wave is A(l). This expression may be approximated by k(T)=A(0)(1+T/T-W)(-m) exp[(T/T-W)/(1+T/T-W)]. For CN+O-2--> NCO+O and CO+NO the above expression reproduces the rate data, the branching ratio to the CO+NO channel, and the reactive cross section for the NCO+O channel. The rate coefficient for the NCO+O channel is given by k(cm(3) s(-1))=1.79x10(-10)(+T/21.7)(-1.38){exp[(T/21.7)/(1+T/21.7)]-1}+4.62x10(-12) exp[(T/21.7)/(1+T/21.7)] while for CO+NO we obtain k(cm(3) s(-1))=1.79x10(-10)(1+T/21.7)(-1.38). An analytic form of the C-O bonding potential and the electric dipole-quadrupole interaction is used to show that the quantum threshold region extends up to 7 K. These results demonstrate the need of a complete quantum treatment for reactions that proceed on potential surfaces without a barrier. (C) 1999 American Institute of Physics. [S0021-9606(99)01129-0]. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Hessler, JP (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 41 TC 8 Z9 8 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1999 VL 111 IS 9 BP 4068 EP 4076 DI 10.1063/1.479183 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 228BM UT WOS:000082116000036 ER PT J AU Martin, JE Anderson, RA AF Martin, JE Anderson, RA TI Electrostriction in field-structured composites: Basis for a fast artificial muscle? SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRORHEOLOGICAL FLUIDS; SIMULATION; FORCES; GELS AB The electrostriction of composites consisting of dielectric particles embedded in a gel or elastomer is discussed. It is shown that when these particles are organized by a uniaxial field before gelation, the resulting field-structured composites are expected to exhibit enhanced electrostriction in a uniform field applied along the same axis as the structuring field. The associated stresses might be large enough to form the basis of a polymer-based fast artificial muscle. (C) 1999 American Institute of Physics. [S0021-9606(99)70131-5]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Martin, JE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 21 TC 42 Z9 42 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1999 VL 111 IS 9 BP 4273 EP 4280 DI 10.1063/1.479725 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 228BM UT WOS:000082116000057 ER PT J AU Nilson, RH Griffiths, SK AF Nilson, RH Griffiths, SK TI Condensation pressures in small pores: An analytical model based on density functional theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SIZE DISTRIBUTION; ADSORPTION; CARBON; MICROPORES; NITROGEN; FLUIDS AB Integral methods are used to derive an analytical expression describing fluid condensation pressures in slit pores bounded by parallel plane walls. To obtain this result, the governing equations of density functional theory (DFT) are integrated across the pore width assuming that fluid densities within adsorbed layers are spatially uniform. The thickness, density, and free energy of these layers are expressed as composite functions constructed from asymptotic limits applicable to small and large pores. By equating the total free energy of the adsorbed layers to that of a liquid-full pore, we arrive at a closed-form expression for the condensation pressure in terms of the pore size, surface tension, and Lennard-Jones parameters of the adsorbent and adsorbate molecules. The resulting equation reduces to the Kelvin equation in the large-pore limit. It further reproduces the condensation pressures computed by means of the full DFT equations for all pore sizes in which phase transitions are abrupt. Finally, in the limit of extremely small pores, for which phase transitions may be smooth and continuous, this simple analytical expression provides a good approximation to the apparent condensation pressure indicated by the steepest portion of the adsorption isotherm computed via DFT. (C) 1999 American Institute of Physics. [S0021-9606(99)70133-9]. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Nilson, RH (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 17 TC 29 Z9 29 U1 4 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 1999 VL 111 IS 9 BP 4281 EP 4290 DI 10.1063/1.479726 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 228BM UT WOS:000082116000058 ER PT J AU Battaile, CC Srolovitz, DJ Oleinik, II Pettifor, DG Sutton, AP Harris, SJ Butler, JE AF Battaile, CC Srolovitz, DJ Oleinik, II Pettifor, DG Sutton, AP Harris, SJ Butler, JE TI Etching effects during the chemical vapor deposition of (100) diamond SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELEMENTARY REACTION-MECHANISM; ATOMIC-SCALE SIMULATIONS; MONTE-CARLO SIMULATIONS; CVD-GROWN DIAMOND; HOMOEPITAXIAL DIAMOND; TIGHT-BINDING; METHYL RADICALS; 113 FACETS; ACETYLENE; SURFACE AB Current theories of CVD growth on (100) diamond are unable to account for the numerous experimental observations of slow-growing, locally smooth (100)(2x1) films. In this paper we use quantum mechanical calculations of diamond surface thermochemistry and atomic-scale kinetic Monte Carlo simulations of deposition to investigate the efficacy of preferential etching as a mechanism that can help to reconcile this discrepancy. This etching mechanism allows for the removal of undercoordinated carbon atoms from the diamond surface. In the absence of etching, simulated growth on the (100)(2x1) surface is faster than growth on the (110) and (111) surfaces, and the (100) surface is atomically rough. When etching is included in the simulations, the (100) growth rates decrease to values near those observed experimentally, while the rates of growth on the other surfaces remain largely unaffected and similar to those observed experimentally. In addition, the etching mechanism promotes the growth of smooth (100) surface regions in agreement with numerous scanning probe studies. (C) 1999 American Institute of Physics. [S0021-9606(99)70531-3]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. Univ Oxford, Dept Mat, Oxford OX1 3PH, England. GM Corp, Ctr Res & Dev, Dept Phys & Phys Chem, Warren, MI 48090 USA. USN, Res Lab, Div Chem, Gas Surface Dynam Sect, Washington, DC 20375 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM ccbatta@sandia.gov RI Butler, James/B-7965-2008; Harris, Stephen/B-9584-2010; Oleynik, Ivan/R-5004-2016 OI Butler, James/0000-0002-4794-7176; Oleynik, Ivan/0000-0002-5348-6484 NR 66 TC 60 Z9 61 U1 3 U2 21 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 SEP 1 PY 1999 VL 111 IS 9 BP 4291 EP 4299 DI 10.1063/1.479727 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 228BM UT WOS:000082116000059 ER PT J AU Eddy, WF Fitzgerald, M Genovese, C Lazar, N Mockus, A Welling, J AF Eddy, WF Fitzgerald, M Genovese, C Lazar, N Mockus, A Welling, J TI The challenge of functional magnetic resonance imaging SO JOURNAL OF COMPUTATIONAL AND GRAPHICAL STATISTICS LA English DT Article DE experimental design; massive dataset; neuropsychology ID TEST-RETEST RELIABILITY; SENSORY STIMULATION; INTERPOLATION; ACTIVATION AB Functional magnetic resonance imaging of the human brain in action presents large statistical and computational challenges. Here we describe those challenges and provide references to a number of other papers where detailed methods developed to meet them are reported. The first seven sections of this paper were written in 1995 when our work was in its infancy. The last four sections were written more recently, to update the earlier sections and to show the directions we have gone and the directions we intend to go. C1 Carnegie Mellon Univ, Dept Stat, Pittsburgh, PA 15213 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. AT&T Bell Labs, Software Prod Res Dept, Lucent Technol, Tech Staff, Naperville, IL 60566 USA. Carnegie Mellon Univ, Pittsburgh Supercomp Ctr, Pittsburgh, PA 15213 USA. RP Eddy, WF (reprint author), Carnegie Mellon Univ, Dept Stat, Pittsburgh, PA 15213 USA. NR 17 TC 9 Z9 9 U1 0 U2 1 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 USA SN 1061-8600 J9 J COMPUT GRAPH STAT JI J. Comput. Graph. Stat. PD SEP PY 1999 VL 8 IS 3 BP 545 EP 558 DI 10.2307/1390875 PG 14 WC Statistics & Probability SC Mathematics GA 245XQ UT WOS:000083134100013 ER PT J AU Baldwin, C Brown, PN Falgout, R Graziani, F Jones, J AF Baldwin, C Brown, PN Falgout, R Graziani, F Jones, J TI Iterative linear solvers in a 2D radiation-hydrodynamics code: Methods and performance SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE radiation diffusion; iterative methods; multigrid; incomplete factorization AB Computer codes containing both hydrodynamics and radiation play a central role in simulating both astrophysical and inertial confinement fusion (ICF) phenomena. A crucial aspect of these codes is that they require an implicit solution of the radiation diffusion equations. We present in this paper the results of a comparison of five different linear solvers on a range of complex radiation and radiation-hydrodynamics problems. The linear solvers used are diagonally scaled conjugate gradient, GMRES with incomplete LU preconditioning, conjugate gradient with incomplete Cholesky preconditioning, multigrid, and multigrid-preconditioned conjugate gradient. These problems involve shock propagation, opacities varying over 5-6 orders of magnitude, tabular equations of state, and dynamic ALE (Arbitrary Lagrangian Eulerian) meshes. We perform a problem size scalability study by comparing linear solver performance over a wide range of problem sizes from 1000 to 100,000 zones. The fundamental question we address in this paper is: is it more efficient to invert the matrix in many inexpensive steps (like diagonally scaled conjugate gradient) or in fewer expensive steps (like multigrid)? In addition, what is the answer to this question as a function of problem size and is the answer problem dependent? We find that the diagonally scaled conjugate gradient method performs poorly with the growth of problem size, increasing in both iteration count and overall CPU time with the size of the problem and also increasing for larger time steps. For all problems considered, the multigrid algorithms scale almost perfectly (i.e., the iteration count is approximately independent of problem size and problem time step). For pure radiation flow problems (i.e., no hydrodynamics), we see speedups in CPU time of factors of approximate to 15-30 for the largest problems, when comparing the multigrid solvers relative to diagonal scaled conjugate gradient. For the incomplete factorization preconditioners, we see a weak dependence of iteration count on problem size. The speedups observed for pure radiation flow are typically on the order of 10 relative to diagonal scaled conjugate gradient. For radiation-hydrodynamics problems, we again see multigrid scaling perfectly. However, for the problems considered, we see speedups relative to diagonal scaled conjugate gradient of no more than approximate to 10, with incomplete Cholesky in fact either equaling or outperforming multigrid. We trace these observations to the time step control and the feature of ALE to relax distorted zones. (C) 1999 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. RP Baldwin, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, L-561, Livermore, CA 94550 USA. OI Jones, Jim/0000-0002-0144-6130 NR 19 TC 24 Z9 28 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 1999 VL 154 IS 1 BP 1 EP 40 DI 10.1006/jcph.1999.6290 PG 40 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 233MG UT WOS:000082430200001 ER PT J AU Cook, AR AF Cook, AR TI A consistent approach to large eddy simulation using adaptive mesh refinement SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE turbulence; large eddy simulation; adaptive mesh refinement ID EQUATIONS AB The large eddy simulation of turbulent flows is discussed with particular attention paid to the issue of commutation of differentiation and filtering. Multi-level adaptive mesh refinement is proposed as a means of mostly avoiding commutation errors where increased grid resolution is required to capture key flow features. The strategy is to employ multiple uniform grids in a nested hierarchy using a constant-width filter for each grid. It is shown that commutivity of fine and coarse grid filters must be enforced in order to consistently relate variables at different refinement levels. Methods for treating fine grid boundaries and walls are also discussed. It is shown that errors associated with boundary treatments are small and localized. (C) 1999 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Cook, AR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 7 Z9 7 U1 1 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 1999 VL 154 IS 1 BP 117 EP 133 DI 10.1006/jcph.1999.6304 PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 233MG UT WOS:000082430200005 ER PT J AU Garcia, AL Bell, JB Crutchfield, WY Alder, BJ AF Garcia, AL Bell, JB Crutchfield, WY Alder, BJ TI Adaptive mesh and algorithm refinement using direct simulation Monte Carlo SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID NAVIER-STOKES EQUATIONS; CONSISTENT BOLTZMANN ALGORITHM; HYPERBOLIC CONSERVATION-LAWS; RAREFIED-GAS DYNAMICS; COUPLING BOLTZMANN; SLIP LENGTH; DILUTE GAS; HYDRODYNAMICS; FLOWS; BEARINGS AB Adaptive mesh and algorithm refinement (AMAR) embeds a particle method within a continuum method at the lineal level of an adaptive mesh refinement (AMR) hierarchy. The coupling between the particle region and the overlaying continuum grid is algorithmically equivalent to that between the fine and coarse levels of AMR. Direct simulation Monte Carlo (DSMC) is used as the particle algorithm embedded within a Godunov-type compressible Navier-Stokes solver. Several examples are presented and compared with purely continuum calculations. (C) 1999 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. RP Garcia, AL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. EM garcia@mothra.lbl.gov; jbb@mothra.lbl.gov; wyc@mothra.lbl.gov; alder1@llnl.gov NR 48 TC 152 Z9 157 U1 0 U2 13 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 SEP 1 PY 1999 VL 154 IS 1 BP 134 EP 155 DI 10.1006/jcph.1999.6305 PG 22 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 233MG UT WOS:000082430200006 ER PT J AU Wu, K Canning, A Simon, HD Wang, LW AF Wu, K Canning, A Simon, HD Wang, LW TI Thick-restart Lanczos method for electronic structure calculations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Lanczos method; thick-restart scheme; electronic structure calculation; empirical pseudopotential method ID SEMICONDUCTOR QUANTUM DOTS; MOLECULAR-DYNAMICS; ARNOLDI METHOD; ENERGY; MINIMIZATION; ALGORITHM AB This paper describes two recent innovations related to the restarted Lanczos method for eigenvalue problems, namely the thick-restart technique and dynamic restarting schemes. Previous restarted versions of the Lanczos method use considerably more iterations than the non-restarted versions, largely because too much information is discarded during restarting. The thick-restart technique provides a mechanism to preserve a large portion of the existing basis and dynamic restarting schemes decide exactly how many vectors to save. Combining these two new techniques we are able to implement an efficient eigenvalue problem solver. This paper will demonstrate its effectiveness on one particular class of problems for which this method is well suited: linear eigenvalue problems generated from non-selfconsistent electronic structure calculations. (C) 1999 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wu, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. NR 31 TC 33 Z9 34 U1 1 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 1999 VL 154 IS 1 BP 156 EP 173 DI 10.1006/jcph.1999.6306 PG 18 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 233MG UT WOS:000082430200007 ER PT J AU Swartz, B AF Swartz, B TI Good neighborhoods for multidimensional Van Leer limiting SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Van Leer limiting; finite volume; flux corrected transport ID CONSERVATIVE DIFFERENCE SCHEME; ADAPTIVE STENCILS; LAWS C1 Los Alamos Natl Lab, Grp T7, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Grp T7, MS B284, Los Alamos, NM 87545 USA. EM bks@lanl.gov NR 6 TC 7 Z9 7 U1 2 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 1999 VL 154 IS 1 BP 237 EP 241 DI 10.1006/jcph.1999.6308 PG 5 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 233MG UT WOS:000082430200011 ER PT J AU Garrett, JD Peralta, P Michael, JR Chu, F McClellan, KJ Mitchell, TE AF Garrett, JD Peralta, P Michael, JR Chu, F McClellan, KJ Mitchell, TE TI Growth of oriented C11(b)MoSi(2) bicrystals using a modified Czochralski technique SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE silicide; bicrystal; crystal growth; grain boundary ID MOSI2 SINGLE-CRYSTALS AB Oriented bicrystals of pure C11(b) MoSi2 have been grown in a tri-arc furnace using the Czochralski technique. Two single-crystal seeds were used to initiate the growth. Each seed had the orientation intended for one of the grains of the bicrystals, which resulted in a 60 degrees twist boundary on the (1 1 0) plane. Seeds were attached to a water-cooled seed rod, which was pulled at 120 mm/h with the seed rod rotating at 45 rpm. The water-cooled copper hearth was counter-rotated at 160 rpm. Asymmetric growth ridges associated with each seed crystal were observed during growth and confirmed the existence of a bicrystal. It was also found that careful alignment of the seeds was needed to keep the grain boundary from growing out of the boule. The resulting boundary was characterized by imaging and crystallographic techniques in a scanning electron microscope. The boundary was found to be fairly sharp and the misorientation between the grains remained within 2 degrees from the misorientation between the seeds. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. McMaster Univ, Brockhouse Inst Mat Res, Hamilton, ON L8S 4M1, Canada. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Peralta, P (reprint author), Arizona State Univ, Dept Mech & Aerosp Engn, POB 876106, Tempe, AZ 85287 USA. NR 9 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1999 VL 205 IS 4 BP 515 EP 522 DI 10.1016/S0022-0248(99)00332-2 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 238CG UT WOS:000082692900009 ER PT J AU Agnew, SR Vinogradov, AY Hashimoto, S Weertman, JR AF Agnew, SR Vinogradov, AY Hashimoto, S Weertman, JR TI Overview of fatigue performance of Cu processed by severe plastic deformation SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Fatigue and Internal Friction in Miniature Structures and Components, at the 1999 TMS Annual Meeting CY MAR 02-03, 1999 CL SAN DIEGO, CALIFORNIA SP Minerals Met & Mat Soc, IEEE, TMS, Struct Mat Div, Non Ferrous Met Comm, TMS, Magnet & Photon Mat Div, Electr Packaging & Interconnect Mat Comm, ASM Int, Mat Sci Crit Technol Sector, Flow & Fracture Comm DE fatigue; copper; ultrafine grain; cyclic softening; shear bands; persistent slip bands; severe plastic deformation ID STRESS-STRAIN RESPONSE; POLYCRYSTALLINE COPPER; SINGLE-CRYSTALS; GRAINED COPPER; CYCLE FATIGUE; BEHAVIOR; ALLOYS; AMPLITUDES; FAILURE; SHEAR AB This study investigates discrepancies regarding cyclic softening of Cu processed by severe plastic deformation (SPD). All samples softened if the microhardnesses before and after fatiguing are compared. However, the effect decreases if the strain amplitude is small, Delta epsilon(p) <1 x 10(-3). Samples with equiaxed subgrains were more resistant to softening and thermal recovery. All samples had "persistent" shear bands except those tested at the highest amplitudes, Delta epsilon(p) >1 x 10(-2). Cu processed by SPD exhibits an enhanced fatigue life at low amplitudes. However, low thermal stability, potential for softening, and poor low-cycle properties discredit this advantage. C1 Kyoto Univ, Kyoto 6068501, Japan. Kanazawa Univ, Kanazawa, Ishikawa 9205667, Japan. Northwestern Univ, Evanston, IL 60208 USA. RP Agnew, SR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Weertman, Julia/B-7540-2009; VINOGRADOV, ALEXEI/A-7175-2009 OI VINOGRADOV, ALEXEI/0000-0001-9585-2801 NR 39 TC 123 Z9 123 U1 6 U2 44 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD SEP PY 1999 VL 28 IS 9 BP 1038 EP 1044 DI 10.1007/s11664-999-0181-0 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 234FG UT WOS:000082473400007 ER PT J AU Boyd, GA McClelland, JD AF Boyd, GA McClelland, JD TI The impact of environmental constraints on productivity improvement in integrated paper plants SO JOURNAL OF ENVIRONMENTAL ECONOMICS AND MANAGEMENT LA English DT Article ID DISTANCE FUNCTION-APPROACH; UNDESIRABLE OUTPUTS; NONPARAMETRIC APPROACH AB This paper utilizes a flexible measure of productivity that includes environmental performance. We characterize the loss of potential productive output due to environmental constraints, decomposing losses into those resulting from the commitment of capital to pollution abatement and those losses that arise from other sources. We also assess the potential for improvements that increase productivity and reduce pollution. Results from the paper industry show a "win-win" potential for inputs and pollution to be simultaneously reduced by 2% to 8%, without reducing productivity. We also find that environmental constraints reduce production by 9%, a quarter of which results from pollution abatement capital constraints. (C) 1999 Academic Press. C1 US Dept Treasury, Off Tax Anal, Chilung 20220, Taiwan. Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA. RP McClelland, JD (reprint author), US Dept Treasury, Off Tax Anal, 1500 Penn Ave NW, Chilung 20220, Taiwan. NR 25 TC 84 Z9 89 U1 1 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0095-0696 J9 J ENVIRON ECON MANAG JI J.Environ.Econ.Manage. PD SEP PY 1999 VL 38 IS 2 BP 121 EP 142 DI 10.1006/jeem.1999.1082 PG 22 WC Business; Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA 238GL UT WOS:000082702500001 ER PT J AU Vadasz, P Havstad, MA AF Vadasz, P Havstad, MA TI The effect of permeability variations on the flow in a heterogeneous porous channel subject to rotation SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB A significant effect of permeability variations on the three-dimensional fluid pow in a heterogeneous porous channel subject to rotation is presented. The results of a numerical solution to the governing equations confirm for the more general case the conclusions from earlier analytical investigations, which suggest that permeability functions be classified corresponding to whether their variation is monotonic or not, and to whether their vertical gradient is positive or not. Unicellular and multiple vortex solutions are obtained for the secondary, flow in the plane perpendicular to the imposed axial flow while their direction is dictated by the corresponding class of permeability function as applicable. The impact of rotation on the imposed axial flow is shown to be significant as well, leading to different axial flow fields depending again on the class of permeability function used. In particular the rotation impacts significantly in creating axial flow deficiencies in some regions on the cross section. C1 Univ Durban Westville, ZA-4000 Durban, South Africa. Univ Calif Lawrence Livermore Natl Lab, Atom Vapor Laser Isotope Separat Program, Livermore, CA 94550 USA. RP Vadasz, P (reprint author), Univ Durban Westville, Private Bag X54001, ZA-4000 Durban, South Africa. NR 8 TC 3 Z9 3 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD SEP PY 1999 VL 121 IS 3 BP 568 EP 573 DI 10.1115/1.2823506 PG 6 WC Engineering, Mechanical SC Engineering GA 238JY UT WOS:000082708200008 ER PT J AU Viallet, PM Vo-Dinh, V Bunde, T Ribou, AC Vigo, J Salmon, JM AF Viallet, PM Vo-Dinh, V Bunde, T Ribou, AC Vigo, J Salmon, JM TI Flourescent molecular reporter for the 3-D conformation of protein subdomains: The Mag-Indo system SO JOURNAL OF FLUORESCENCE LA English DT Article DE Mag-Indo-1; calcium; energy transfer; fluorescence quenching; synchronous fluorescence; protein conformation; molecular probe; protein folding ID CYTOSOLIC FREE MAGNESIUM; SYNCHRONOUS LUMINESCENCE; FLUORESCENT-PROBES; MAG-INDO-1; RESOLUTION; CELLS AB In this study we investigate the use of the fluorescent probe Mag-Indo-1 as a molecular reporter for the three-dimensional (3-D) conformation of protein subdomains. Magnesium complexation with this probe results in a shift of the emission fluorescence spectrum from 480 to 417 nm with an intensity proportional to the magnesium concentration in the range 0.6 to 30 mM. Although designed as a specific magnesium chelator, Mag-Indo-1 is also able to bind calcium and zinc, the dissociation constants of the reactions being dependent of the nature of the cation. Furthermore, Mag-Indo-1 can also bind proteins through a specific interaction with some histidine residues. That interaction induces a characteristic spectral shift of the emission fluorescence spectra from 480 to 457 nm. All these properties suggest that Mag-Indo-1 could be used to study protein-cation binding. Emission and synchronous fluorescence techniques have been used to monitor the interaction of Mag-Indo-1 with proteins such as bovine serum albumin, human serum albumin, and turkey egg white lysozyme. A method of resolution of complex fluorescence spectra was used to calculate the number of interaction sites and the correlative dissociation constants. Depending on the nature of the protein, a quenching of the natural fluorescence of the protein was observed, a process associated with energy transfer from some tryptophan(s) to Mag-Indo-1. These data were tentatively correlated with the available information on the 3-D conformation of the proteins investigated. The results of this study indicate that Mag-Indo-1 can be used as an intramolecular fluorescent ruler to monitor changes in the 3-D conformation of specific subdomains of proteins. C1 Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, Oak Ridge, TN 37831 USA. Univ Perpignan, Phys Chem Lab, Grp Quantitat Microfluorometry, F-66860 Perpignan, France. RP Vo-Dinh, V (reprint author), Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 6 Z9 6 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1053-0509 J9 J FLUORESC JI J. Fluoresc. PD SEP PY 1999 VL 9 IS 3 BP 153 EP 161 PG 9 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical SC Biochemistry & Molecular Biology; Chemistry GA 242DR UT WOS:000082923400001 ER PT J AU Yeardley, RB Scarpino, PV Haines, JR AF Yeardley, RB Scarpino, PV Haines, JR TI Effects of acidity on the exo-enzyme and recycling capabilities of a sediment microbial community SO JOURNAL OF FRESHWATER ECOLOGY LA English DT Article ID PLANT LITTER DECOMPOSITION; MINE DRAINAGE; LAKE; PRECIPITATION AB We determined effects of acidification on sediment aerobic heterotrophic exo-amylase and exo-protease producing microbial populations in addition to effects on the total microbial population. Acidification of microcosms to sediment pHs of 6, 5, 4, and 3 followed by plate counts showed that numbers of total aerobic heterotrophic microbes, as well as numbers exo-amylase producers and exo-protease producers, decreased at pH 3. It appears that pH 3 may represent a critical level of damage. Numbers of total aerobic heterotrophs also decreased at pH 4. Numbers of all groups increased at pH 6. An accompanying change in species composition was observed with acidification, in which a type of microbe with little production of exo-amylase or exo-protease became dominant in the microbial. community as pH decreased. Analysis of three metals (Al, Pb, Cu) indicated an increased mobilization of metals from the sediments at low pHs. C1 US EPA, ORISE, Cincinnati, OH 45268 USA. Univ Cincinnati, Dept Civil & Environm Engn, Cincinnati, OH 45219 USA. RP Yeardley, RB (reprint author), US EPA, ORISE, 26 W Martin Luther King Dr, Cincinnati, OH 45268 USA. NR 25 TC 0 Z9 0 U1 0 U2 5 PU OIKOS PUBL INC PI LA CROSSE PA PO BOX 2558, LA CROSSE, WI 54601 USA SN 0270-5060 J9 J FRESHWATER ECOL JI J. Freshw. Ecol. PD SEP PY 1999 VL 14 IS 3 BP 301 EP 312 DI 10.1080/02705060.1999.9663685 PG 12 WC Ecology; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 235GN UT WOS:000082534100005 ER PT J AU Neilson, GH Carreras, BA D'Ippolito, DA Gruber, O Kikuchi, M McGuire, K Post, DE Callen, JD Diamond, PH Gentle, KW Hooper, EB Marmar, ES Phillips, CK Taylor, TS AF Neilson, GH Carreras, BA D'Ippolito, DA Gruber, O Kikuchi, M McGuire, K Post, DE Callen, JD Diamond, PH Gentle, KW Hooper, EB Marmar, ES Phillips, CK Taylor, TS TI The Fusion Science Research Plan for the major US Tokamaks SO JOURNAL OF FUSION ENERGY LA English DT Article DE fusion science; fusion major facilities; tokamaks AB This is the May 1996 report of a subpanel of the US Department of Energy Fusion Energy Sciences Advisory Committee (FESAC), charged with conducting a review of the progress, priorities and potential near-term contributions of TFTR, DIII-D and Alcator C-MOD (and other facilities as appropriate) as part of the transition to a Fusion Energy Sciences Program and produce an optimum plan for obtaining the most scientific benefit from them. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Texas, Austin, TX 78712 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. MIT, Cambridge, MA 02139 USA. Gen Atom Co, San Diego, CA 92138 USA. RP Neilson, GH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Post, Douglass/L-3773-2014; Kikuchi, Mitsuru/O-1036-2015 OI Post, Douglass/0000-0001-9271-0023; Kikuchi, Mitsuru/0000-0002-5485-8737 NR 0 TC 1 Z9 1 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1999 VL 18 IS 3 BP 117 EP 160 PG 44 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 463BJ UT WOS:000170456700001 ER PT J AU Najmabadi, F Drake, J Freidberg, J Hill, D Mauel, M Navratil, G Nevins, W Ono, M Prager, S Rosenbluth, M Stambaugh, R Schoenberg, K Takase, Y Wilson, K AF Najmabadi, F Drake, J Freidberg, J Hill, D Mauel, M Navratil, G Nevins, W Ono, M Prager, S Rosenbluth, M Stambaugh, R Schoenberg, K Takase, Y Wilson, K TI The report of the subpanel to FESAC concerning alternative concepts SO JOURNAL OF FUSION ENERGY LA English DT Article DE fusion science; fusion energy; fusion alternative concepts ID REVERSED-FIELD PINCH; CONFIGURATION; STABILITY; PLASMA; STABILIZATION; TURBULENCE; EQUILIBRIA; RELAXATION; REACTOR; MODE AB This is the July 1996 report of a subpanel of the US Department of Energy Fusion Energy Sciences Advisory Committee (FESAC), charged with reviewing the present status of fusion alternative concept development and the prospects for alternative concepts not only as fusion power systems but also the scientific contributions of alternative concept research to the fusion energy sciences program and to plasma science in general. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Maryland, College Pk, MD 20742 USA. MIT, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Columbia Univ, New York, NY 10027 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Wisconsin, Madison, WI 53706 USA. Gen Atom Co, San Diego, CA 92138 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Najmabadi, F (reprint author), Univ Calif San Diego, La Jolla, CA 92093 USA. NR 72 TC 1 Z9 1 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 1999 VL 18 IS 3 BP 161 EP 193 DI 10.1023/A:1019284124748 PG 33 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 463BJ UT WOS:000170456700002 ER PT J AU Gary, SP Cairns, IH AF Gary, SP Cairns, IH TI Electron temperature anisotropy instabilities: Whistler, electrostatic and z mode SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID AURORAL KILOMETRIC RADIATION; RADIO EMISSIONS; SOURCE REGIONS; THETA-AURORA; PLASMA-WAVES; POLAR-CAP; CYCLOTRON; MAGNETOSPHERE; GENERATION; SIMULATIONS AB An electron temperature anisotropy T-perpendicular to e/T parallel to e > 1 leads to excitation of three distinct instabilities in collisionless plasmas at frequencies below the electron cyclotron frequency \Omega(e)\ (Here perpendicular to and parallel to denote directions relative to the background magnetic field B-o.). Linear Vlasov theory is used to study these growing modes, with emphasis on the scaling of the temperature anisotropy at instability threshold. If the electron plasma frequency omega(e) is greater than \Omega(e)\ and electrons are sufficiently hot, the whistler is the unstable mode with smallest anisotropy threshold; this electromagnetic mode has maximum growth rate at propagation parallel to B-o. At omega(e) > 0.5\Omega(e)\, an electrostatic electron anisotropy instability can arise at propagation oblique to B-o; this mode may have the smallest threshold for sufficiently cool electrons and omega(e) similar to \Omega(e)\. And T-perpendicular to e/T parallel to(e) > 1 drives the z mode unstable at omega(e) < \Omega(e)\; this electromagnetic mode also has maximum growth rate at parallel propagation and is the persistent instability at omega(e) less than or similar to 0.5\Omega(e)\ The results are discussed in connection with observations from the polar and auroral regions of the terrestrial magnetosphere. C1 Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. RP Gary, SP (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. NR 34 TC 22 Z9 24 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1999 VL 104 IS A9 BP 19835 EP 19842 DI 10.1029/1999JA900296 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232FK UT WOS:000082360100008 ER PT J AU Gary, SP Neagu, E Skoug, RM Goldstein, BE AF Gary, SP Neagu, E Skoug, RM Goldstein, BE TI Solar wind electrons: Parametric constraints SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ULYSSES OBSERVATIONS; HEAT-FLUX; INSTABILITY; TEMPERATURE; ANISOTROPY; SPACECRAFT; WAVES; 1-AU AB Solar wind electrons are often observed to consist of two distinguishable components, a thermal, more dense core and a suprathermal, less dense halo. In this core/halo model linear Vlasov theory for the whistler heat flux instability predicts dimensionless heat flux thresholds which decrease as the electron core beta, <(beta)over tilde>parallel to(c), increases. It has been proposed that this theoretical threshold corresponds to an observable upper bound on the electron heat flux. Linear theory also predicts that there is a critical value of <(beta)over tilde>parallel to c below which the whistler heat flux instability does not have appreciable growth in the solar wind; there is another suggestion that this corresponds to an observable lower bound on <(beta)over tilde>parallel to(c). These two proposals are examined by comparison of linear theory and data from the initial in-ecliptic phase of the Ulysses mission. The instability threshold does provide a statistical constraint on observed solar wind heat fluxes, and the critical <(beta)over tilde>parallel to(c) Of theory is not inconsistent with a statistical lower bound on the observations of that parameter. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gary, SP (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. NR 28 TC 14 Z9 14 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1999 VL 104 IS A9 BP 19843 EP 19849 DI 10.1029/1999JA900244 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232FK UT WOS:000082360100009 ER PT J AU Gosling, JT AF Gosling, JT TI On the determination of electron polytrope indices within coronal mass ejections in the solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC CLOUDS; ULYSSES OBSERVATIONS; THERMAL ELECTRONS; VOYAGER 2; PLASMA; PARAMETERS; SHOCK; EVOLUTION; INDEX; AU AB Electron temperature and density often appear to be negatively correlated with one another as a coronal mass ejection, CME, in the solar wind passes over a spacecraft at 1 AU and beyond. It has been suggested that this negative correlation within magnetic clouds, which form a subset of all CMEs, implies that the electron polytropic index for the plasma within the clouds is significantly less than 1.0. We argue that single-point measurements of density and temperature within clouds do not speak to the issue of the coupled evolution of density and temperature that occurs as the clouds expand out into the heliosphere, and thus do not provide a measure of the polytropic index within them. Moreover, we show that observed electron temperatures within magnetic clouds and CMEs close to the Sun, at 1 AU, and at large heliocentric distances do not agree with predictions based upon electron polytropic indices significantly less than 1.0. We suggest that the negative correlation between electron temperature and density often observed within CMEs and magnetic clouds at 1 AU and beyond simply reflects the presence of structure within the CMEs and the plasma's tendency to achieve local pressure balance as it evolves outward from the Sun. Our results indicate that self-similar models that require the electron polytrope index to be less than 1.0 in order for a magnetic cloud to expand are physically unrealistic. C1 Univ Calif Los Alamos Natl Lab, Grp NIS1, Los Alamos, NM 87545 USA. RP Gosling, JT (reprint author), Univ Calif Los Alamos Natl Lab, Grp NIS1, MS D466, Los Alamos, NM 87545 USA. NR 50 TC 16 Z9 16 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 SEP 1 PY 1999 VL 104 IS A9 BP 19851 EP 19857 DI 10.1029/1999JA900254 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232FK UT WOS:000082360100010 ER PT J AU Birn, J Hesse, M Haerendel, G Baumjohann, W Shiokawa, K AF Birn, J Hesse, M Haerendel, G Baumjohann, W Shiokawa, K TI Flow braking and the substorm current wedge SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FIELD-ALIGNED CURRENTS; MAGNETOTAIL RECONNECTION; MAGNETOSPHERIC SUBSTORMS; CURRENT DISRUPTION; CURRENT SHEET; SIMULATIONS; DIVERSION; PHASE; TAIL AB Recent models of magnetotail activity have associated the braking of earthward flow with dipolarization and the reduction and diversion of cross-tail current, that is, the signatures of the substorm current wedge. Estimates of the magnitude of the diverted current by Haerendel [1992] and Shiokawa et al. [1997, 1998] tend to be lower than results from computer simulations of magnetotail reconnection and tail collapse [Birn and Hesse, 1996], despite similar underlying models. An analysis of the differences between these estimates on the basis of the simulations gives a more refined picture of the diversion of perpendicular into parallel currents. The inertial currents considered by Haerendel [1992] and Shiokawa et al. [1997] contribute to the initial current reduction and diversion, but the dominant and more permanent contribution stems from the pressure gradient terms, which change in connection with the field collapse and distortion. The major effect results form pressure gradients in the z direction, rather than from the azimuthal gradients [Shiokawa et al., 1998], combined with changes in B-y and B-x. The reduction of the current density near the equatorial plane is associated with a reduction of the curvature drift which overcompensates changes of the magnetization current and of the gradient B drift current. In contrast to the inertial current effects, the pressure gradient effects persist even after the burst of earthward flow ends. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Electrodynam Branch, Greenbelt, MD 20771 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi, Japan. RP Los Alamos Natl Lab, NIS-1,POB 1663,MS D466, Los Alamos, NM 87545 USA. EM jbirn@lanl.gov; hesse@gsfc.nasa.gov; hae@mpe-garching.mpg.de; bj@mpe.mpg.de; shiokawa@stelab.nagoya-u.ac.jp RI Hesse, Michael/D-2031-2012; Baumjohann, Wolfgang/A-1012-2010 OI Baumjohann, Wolfgang/0000-0001-6271-0110 NR 22 TC 145 Z9 146 U1 0 U2 4 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 SEP 1 PY 1999 VL 104 IS A9 BP 19895 EP 19903 DI 10.1029/1999JA900173 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232FK UT WOS:000082360100015 ER PT J AU Longmire, JL Hahn, DC Roach, JL AF Longmire, JL Hahn, DC Roach, JL TI Low abundance of microsatellite repeats in the genome of the brown-headed cowbird (Molothrus ater) SO JOURNAL OF HEREDITY LA English DT Article ID DNA LIBRARIES; REPETITIVE ELEMENTS; EUKARYOTIC GENOMES; SEQUENCES; ORGANIZATION; IDENTIFICATION; POLYMORPHISMS; CONSTRUCTION; EVOLUTION; FREQUENCY AB A cosmid library made from brown-headed cowbird (Molothrus ater) DNA was examined for representation of 17 distinct microsatellite motifs including all possible mono-, di-, and trinucleotide microsatellites, and the tetranucleotide repeat (GATA)(n). The overall density of microsatellites within cowbird DNA was found to be one repeat per 89 kb and the frequency of the most abundant motif, (AGC), was once every 382 kb, The abundance of microsatellites within the cowbird genome is estimated to be reduced approximately 15-fold compared to humans, The reduced frequency of microsatellites seen in this study is consistent with previous observations indicating reduced numbers of microsatellites and other interspersed repeats in avian DNA. In addition to providing new information concerning the abundance of microsatellites within an avian genome, these results provide useful insights for selecting cloning strategies that might be used in the development of locus-specific microsatellite markers for avian studies. C1 Los Alamos Natl Lab, Genom Grp, Los Alamos, NM 87545 USA. US Geol Survey, Patuxent Wildlife Res Ctr, Laurel, MD USA. RP Longmire, JL (reprint author), Los Alamos Natl Lab, Genom Grp, MS-M880, Los Alamos, NM 87545 USA. EM longmire@telomere.lanl.gov NR 28 TC 7 Z9 9 U1 0 U2 2 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD SEP-OCT PY 1999 VL 90 IS 5 BP 574 EP 578 DI 10.1093/jhered/90.5.574 PG 5 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 248AX UT WOS:000083254100016 PM 10544500 ER PT J AU de Boer, J AF de Boer, J TI Large N elliptic genus and AdS/CFT correspondence SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE string duality; conformal field models in string theory; black holes in string theory ID FIELD-THEORY; GENERA; SYMMETRIES; ANOMALIES; SURFACES; STRINGS AB According to one of Maldacena's dualities, type IIB string theory on AdS(3) X S-3 X K3 is equivalent to a certain N = (4, 4) superconformal field theory. In this note we compute the elliptic genus of the boundary theory in the supergravity approximation. A finite quantity is obtained once we introduce a particular exclusion principle. In the regime where the supergravity approximation is reliable, we find exact agreement with the elliptic genus of a sigma model with target space K3(N) / SN. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP de Boer, J (reprint author), Univ Calif Berkeley, Dept Phys, 366 Le Conte Hall, Berkeley, CA 94720 USA. EM deboer@thsrv.lbl.gov NR 25 TC 41 Z9 41 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP 1 PY 1999 IS 5 AR 017 PG 14 WC Physics, Particles & Fields SC Physics GA 231NW UT WOS:000082317500017 ER PT J AU Dorey, N Hollowood, TJ Tong, D AF Dorey, N Hollowood, TJ Tong, D TI The BPS spectra of gauge theories in two and four dimensions SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE solitons monopoles and instantons; supersymmetry and duality ID SUPERSYMMETRIC CPN-1 MODEL; 2 DIMENSIONS; CHARGES; DUALITY; INSTANTONS; STATES AB We study N = (2, 2) supersymmetric abelian gauge theories in two dimensions. The exact BPS spectrum of these models is shown to coincide with the spectrum of massive hypermultiplets of certain N = 2 supersymmetric gauge theories in four dimensions. A special case of these results involves a surprising connection between four-dimensional N = 2 SQCD with N colours and N-f > N flavours at the root of the baryonic Higgs branch and the supersymmetric C P2N-Nf-1 sigma-model in two dimensions. This correspondence implies a new prediction for the strong-coupling spectrum of the four-dimensional theory. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Los Alamos Natl Lab, Theoret Div T8, Los Alamos, NM 87545 USA. Univ Coll Swansea, Dept Phys, Swansea SA2 8PP, W Glam, Wales. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. RP Dorey, N (reprint author), Univ Washington, Dept Phys, Box 351560, Seattle, WA 98195 USA. EM dorey@phys.washington.edu; pyth@schwinger.lanl.gov; tong@theory.tifr.res.in NR 38 TC 54 Z9 54 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP 1 PY 1999 IS 5 AR 006 DI 10.1088/1126-6708/1999/05/006 PG 46 WC Physics, Particles & Fields SC Physics GA 231NW UT WOS:000082317500006 ER PT J AU Driessen, BJ Feddema, JT Kwok, KS AF Driessen, BJ Feddema, JT Kwok, KS TI Decentralized fuzzy control of multiple nonholonomic vehicles SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE fuzzy logic; mobile robots; decentralized; linear quadratic; group behavior; cooperative robotics; Kalman estimation ID MOBILE ROBOTS; COOPERATION AB This work considers the problem of controlling multiple nonholonomic vehicles so that they converge to a scent source without colliding with each other. Since the control is to be implemented on a simple 8-bit microcontroller, fuzzy control rules are used to simplify a linear quadratic regulator control design. The inputs to the fuzzy controllers for each vehicle are the noisy direction to the source, the distance to the closest neighbor vehicle, and the direction to the closest vehicle. These directions are discretized into four values: forward, behind, left, and right; and the distance into three values: near, far, and gone. The values of the control at these discrete values are obtained based on the collision-avoidance repulsive forces and an attractive force towards the goal. A fuzzy inference system is used to obtain control values from a small number of discrete input values. Simulation results are provided which demonstrate that the fuzzy control law performs well compared to the exact controller. In fact, the fuzzy controller demonstrates improved robustness to noise. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Driessen, BJ (reprint author), Sandia Natl Labs, POB MS 0439, Albuquerque, NM 87185 USA. NR 18 TC 7 Z9 7 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD SEP PY 1999 VL 26 IS 1 BP 65 EP 78 DI 10.1023/A:1008178504755 PG 14 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA 239YB UT WOS:000082797000004 ER PT J AU Setlow, RB AF Setlow, RB TI Spectral regions contributing to melanoma: A personal view SO JOURNAL OF INVESTIGATIVE DERMATOLOGY SYMPOSIUM PROCEEDINGS LA English DT Article; Proceedings Paper CT 47th Montagna Annual Symposium on the Biology of Skin CY AUG 19-23, 1998 CL SNOWMASS, COLORADO SP Orentrich Fdn, Natl Psoriasis Fdn DE albinos; latitude dependence; photoreactivation; fish model ID PYRIMIDINE DIMER FORMATION; HUMAN-SKIN; ULTRAVIOLET-RADIATION; MONODELPHIS-DOMESTICA; MALIGNANT-MELANOMA; WAVELENGTH DEPENDENCE; CANCER INCIDENCE; DNA; INDUCTION; CELLS AB Although human cutaneous melanoma is a complicated disease, the principal etiologic agent for its incidence in fair skin individuals is exposure to sunlight. In order to understand the epidemiology of melanoma - temporal effects, latitude effects, sunscreen effects, albino susceptibility, and differences from nonmelanoma skin cancer one must approach the problem by obtaining clues indicating which wavelengths in sunlight are effective in inducing melanomas, One way is to use an animal model. At present, the only suitable model is a backcross hybrid of small tropical fish of the genus Xiphophorus, bred to have only one tumor suppressor gene, Single UV exposures to 7-d-old fish induce melanomas readily observable by 4 mo. The initial slopes of dose-response curves for exposures at 302, 313, 365, 405, 436, and 547 nm yield sensitivity as a function of wavelength. This action spectrum does not look like the spectrum for light absorption by DNA (mostly in the UVB), but has appreciable sensitivities in the WA and visible regions, and looks like a direct effect of light on DNA plus a large indirect effect on DNA by absorption of light by the intracellular melanin. Because the UVB is only a fraction of solar irradiance, one may calculate that 90% of melanoma induction in humans arises from UVA and visible, assuming the human spectrum is similar to the fish spectrum. The implications of this calculation are that (i) depletion of stratospheric ozone will not affect melanoma incidence, (ii) an increase in sun exposure time as a result of using UVB sunscreens could increase the risk of melanoma, and (iii) the use of high UVA sun tanning devices could increase the risk of melanoma. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Setlow, RB (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 37 TC 42 Z9 42 U1 0 U2 1 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1087-0024 J9 J INVEST DERM SYMP P JI J. Invest. Dermatol. Symp. Proc. PD SEP PY 1999 VL 4 IS 1 BP 46 EP 49 DI 10.1038/sj.jidsp.5640180 PG 4 WC Dermatology SC Dermatology GA 267GA UT WOS:000084348400010 PM 10537007 ER PT J AU Fthenakis, VM Rohatgi, US AF Fthenakis, VM Rohatgi, US TI A model of liquid releases from a submerged vessel SO JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES LA English DT Article DE leakage; fluid mechanics; submerged vessels AB This paper presents an application of fluid mechanics in calculating the leakage of a fluid from a vessel submerged in a river, lake or the ocean. A model is developed to determine leakage due to changes of gravity and pressure forces caused by movements of the vessel or waves at the surface. The equations in the model are solved analytically, and the solution is tested for the sensitivity of its predictions to the variation of input data. The model's predictions of discharges due to differences in hydrostatic pressure are verified with experimental data. Finally, the model is applied to a known case of gasoline leakage from an overturned barge in a river. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Adv Technol, Upton, NY 11973 USA. RP Fthenakis, VM (reprint author), Brookhaven Natl Lab, Dept Adv Technol, Upton, NY 11973 USA. NR 4 TC 3 Z9 5 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0950-4230 J9 J LOSS PREVENT PROC JI J. Loss Prev. Process Ind. PD SEP PY 1999 VL 12 IS 5 BP 437 EP 449 DI 10.1016/S0950-4230(99)00014-5 PG 13 WC Engineering, Chemical SC Engineering GA 221MP UT WOS:000081731100008 ER PT J AU Spichkin, YI Tishin, AM Gschneidner, KA AF Spichkin, YI Tishin, AM Gschneidner, KA TI Elastic properties of a high purity gadolinium single crystal SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE Young's modulus; internal friction; Curie temperature; spin-reorientation temperature; single crystals ID HYDROSTATIC PRESSURE; PHASE-TRANSITIONS; REGION; GD; DY AB The temperature dependence of Young's modulus (E-c and E-b) and the internal friction have been measured in a high-purity gadolinium single crystal along the c- and b- axis in the-temperature range of 4.2-350 K at the frequencies of 800-1200 Hz. At 4.2 K the values of E-c and E-b are equal to 7.25 x 10(11) and 6.14 x 10(11) dyn/cm(2), respectively. The lattice part of Young's modulus has been calculated. The origin of Young's modulus anomalies at the Curie temperature and in the temperature region near 140 K are discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Moscow MV Lomonosov State Univ, Fac Phys, Moscow 119899, Russia. RP Gschneidner, KA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Tishin, Alexander/E-8705-2014; OI Tishin, Alexander/0000-0003-2252-7279; Spichkin, Yury/0000-0002-6088-5395 NR 30 TC 7 Z9 7 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD SEP PY 1999 VL 204 IS 1-2 BP 5 EP 10 DI 10.1016/S0304-8853(99)00435-7 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 224XF UT WOS:000081924700002 ER PT J AU Cooper, LW Beasley, T Aagaard, K Kelley, JM Larsen, IL Grebmeier, JM AF Cooper, LW Beasley, T Aagaard, K Kelley, JM Larsen, IL Grebmeier, JM TI Distributions of nuclear fuel-reprocessing tracers in the Arctic Ocean: Indications of Russian river influence SO JOURNAL OF MARINE RESEARCH LA English DT Article ID I-129; CIRCULATION; SEDIMENTS; PLUTONIUM; SEA; RADIOCESIUM; FACILITIES; TRANSPORT; ISOTOPES; SECTION AB Radionuclide sampling in 1986 and 1993 in the Canada Basin, and in 1993 in the Amundsen Basin and on the adjacent Laptev shelf, provides new insights into the origin, timing, pathways, and mechanisms for dispersal of non-fallout radioactive tracers in the Arctic Ocean. First, samples from the Beaufort Sea shelf, slope, and adjacent basin show a four-fold increase in I-129 concentrations from 1986 to 1993. Second, anthropogenic non-fallout radionuclide concentrations in the Beaufort Sea increase with proximity to slope boundary currents. Third, there is evidence for riverine contributions of anthropogenic radionuclides to surface waters of the Amundsen Basin and the Laptev continental shelf. This evidence includes high surface water burdens of Np-237 and I-129, with the maximum in anthropogenic I-129 found in the least saline and most O-18-depleted waters, consistent with an origin in high-latitude runoff. Additionally, the Np-237/I-129 atom ratios in the Laptev Sea and Amundsen Basin in 1993 were significantly lower than observed elsewhere in the Arctic Ocean and can be reasonably explained by I-129 added during transit of the Russian shelves. The Pu-240/Pu-239 ratios in the water column were mostly near 0.18, consistent both with stratospheric bomb fallout and with the discharged-weighted mean Sellafield ratio during 1966-1985. In the least saline water samples collected at the most shallow Laptev shelf station, however, the Pu ratios were lower, consistent with a non-European nuclear fuel reprocessing source. There are clear secondary maxima in Np-237 and I-129 near 1000 m in the Amundsen Basin, likely associated with the Barents Sea branch of Atlantic water. Finally, the I-129/salinity and I-129/delta(18)O relationships in the Amundsen and Canada Basins at mid-depths are indistinguishable, suggesting effective horizontal dispersion. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. US DOE, New York, NY 10014 USA. Univ Washington, Polar Sci Ctr, Appl Phys Lab, Seattle, WA 98195 USA. Pacific NW Lab, Richland, WA 99352 USA. Univ Tennessee, Dept Ecol & Evolutionary Biol, Knoxville, TN 37996 USA. RP Cooper, LW (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Cooper, Lee/E-5251-2012; Grebmeier, Jacqueline/L-9805-2013 OI Cooper, Lee/0000-0001-7734-8388; Grebmeier, Jacqueline/0000-0001-7624-3568 NR 52 TC 17 Z9 17 U1 0 U2 5 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD SEP PY 1999 VL 57 IS 5 BP 715 EP 738 DI 10.1357/002224099321560546 PG 24 WC Oceanography SC Oceanography GA 273LX UT WOS:000084710100001 ER PT J AU Lu, P Du, TB Loehman, RE Ewsuk, KG Fahrenholtz, WG AF Lu, P Du, TB Loehman, RE Ewsuk, KG Fahrenholtz, WG TI Interfacial microstructure formed by reactive metal penetration of Al into mullite SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID COMPOSITE FORMATION; DIRECTED OXIDATION; MOLTEN ALUMINUM; KINETICS; ALLOYS AB Microstructures in the reaction interface between molten Al and dense mullite have been studied by transmission electron microscopy to provide insight into mechanisms for forming ceramic-metal composites by reactive metal penetration. The reactions, which have the overall stoichiometry 3Al(6)Si(2)O(13) + (8 + x)Al --> 13Al(2)O(3) + xAl + 6Si, were carried out at temperatures of 900, 1100, and 1200 degrees C for 5 and 60 min and 1400 degrees C for 15 min. Observed phases generally were those given in the above reaction; their proportions and interfacial microstructures, however, were strongly dependent on the reaction temperature. Using previously measured reaction kinetics data, the observed temperature dependence of the interfacial microstructure has been modeled as three sequential steps, each of which is rate limiting in a different temperature range. C1 New Mexico Inst Min & Technol, Dept Mat Sci & Engn, Socorro, NM 87801 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Lu, P (reprint author), New Mexico Inst Min & Technol, Dept Mat Sci & Engn, Socorro, NM 87801 USA. OI Fahrenholtz, William/0000-0002-8497-0092 NR 14 TC 8 Z9 8 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1999 VL 14 IS 9 BP 3530 EP 3537 DI 10.1557/JMR.1999.0478 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 304RX UT WOS:000086498900008 ER PT J AU Yashar, PC Barnett, SA Hultman, L Sproul, WD AF Yashar, PC Barnett, SA Hultman, L Sproul, WD TI Deposition and mechanical properties of polycrystalline Y2O3/ZrO2 superlattices SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MULTILAYER STRUCTURES; HARDNESS; STABILIZATION; DEFORMATION; FILM; FRACTURE; CRYSTALS; STRESS; GROWTH; LOAD AB Polycrystalline Y2O3/ZrO2 superlattice thin films were deposited using opposed-cathode reactive magnetron sputtering. Pulsed direct-current power was used to eliminate arcing on the metallic targets. Radio-frequency power was applied to the substrates to achieve ion bombardment of the growing film. In order to reproducibly deposit at high rates in Ar-O-2 mixtures, the Y target voltage was used to indirectly feedback-control the O-2 partial pressure. Deposition rates as high as similar to 70% of the pure metal rates were achieved, typically 3.5 mu m/h. Superlattices with periods ranging from 2.6 to 95 nm were deposited. Y2O3 layer thicknesses were either 75% or 50% of the superlattice period. X-ray diffraction and transmission electron microscopy studies showed well-defined superlattice layers. The ZrO2 layers exhibited the high-temperature cubic-fluorite structure, which was epitaxially stabilized by the cubic Y2O3 layers, for thicknesses less than or equal to 7 nm. The equilibrium monoclinic structure was observed for thicker ZrO2 layers. Nanoindentation hardnesses ranged from 11.1 to 14.5 GPa with little dependence on period. The hardness results are discussed in terms of current superlattice hardening theories. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Linkoping Univ, Dept Phys, Thin Film Phys Div, S-58183 Linkoping, Sweden. Northwestern Univ, Adv Coatings Technol Grp, Evanston, IL 60201 USA. RP Yashar, PC (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Barnett, Scott/B-7502-2009 NR 35 TC 24 Z9 25 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1999 VL 14 IS 9 BP 3614 EP 3622 DI 10.1557/JMR.1999.0488 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 304RX UT WOS:000086498900019 ER PT J AU Stein, DJ Cecchi, JL Hetherington, DL AF Stein, DJ Cecchi, JL Hetherington, DL TI Atomic force microscopy, lateral force microscopy, and transmission electron microscopy investigations and adhesion force measurements for elucidation of tungsten removal mechanisms SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID FRICTION; SCALE AB We investigated various interactions between alumina and tungsten films that occur during chemical mechanical polishing (CMP). Atomic force microscopy surface topography measurements of post-CMP tungsten indicate that the roughness of the tungsten is independent of polish pressure and rotation rate. Pure mechanical abrasion is therefore an unlikely mechanism of material removal during CMP. Transmission electron microscopy images corroborate these results. The adhesion force between alumina and tungsten was measured in solution. The adhesive force increased with KIO3 concentration. Friction forces were measured in solution using lateral force microscopy, The friction force in buffered solutions was independent of KIO3 concentration. These results indicate that interactions other than purely mechanical interactions exist during CMP. C1 Sandia Natl Labs, Microelecet Dev Lab, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RP Stein, DJ (reprint author), Sandia Natl Labs, Microelecet Dev Lab, POB 5800,MS 1084, Albuquerque, NM 87185 USA. NR 22 TC 17 Z9 21 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1999 VL 14 IS 9 BP 3695 EP 3706 DI 10.1557/JMR.1999.0499 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 304RX UT WOS:000086498900030 ER PT J AU Christensen, RM AF Christensen, RM TI A general measure for the ductility of materials SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Stanford Univ, Stanford, CA 94305 USA. RP Christensen, RM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 5 TC 3 Z9 5 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD SEP PY 1999 VL 18 IS 17 BP 1371 EP 1373 DI 10.1023/A:1006698702402 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 228EC UT WOS:000082123300003 ER PT J AU Pal, T Thundat, T Pal, A AF Pal, T Thundat, T Pal, A TI Nanostrings of silver SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID RAMAN-SCATTERING; SURFACE; SPECTROSCOPY; AGGREGATION; ELECTRODE; CHEMISTRY; CLUSTERS; SPECTRA; GELATIN; METAL C1 Indian Inst Technol, Dept Chem, Kharagpur 721302, W Bengal, India. Indian Inst Technol, Dept Civil Engn, Kharagpur 721302, W Bengal, India. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Pal, T (reprint author), Indian Inst Technol, Dept Chem, Kharagpur 721302, W Bengal, India. NR 26 TC 4 Z9 4 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD SEP PY 1999 VL 18 IS 17 BP 1391 EP 1394 DI 10.1023/A:1006659021058 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 228EC UT WOS:000082123300008 ER PT J AU Rawers, J Uggoweitzer, P AF Rawers, J Uggoweitzer, P TI Nitrogen addition to an O-1 tool steel SO JOURNAL OF MATERIALS SYNTHESIS AND PROCESSING LA English DT Article DE iron; carbon; nitrogen; microstructure; characterization; HLP-drip ID FE; ALLOYS AB A new processing technique makes nitrogen alloying possible by adding nitrogen under elevated nitrogen pressure to prealloyed Fe-C ingots during continuous casting, producing a whole new class of precipitation-free, iron-carbon-nitrogen alloys. When both carbon and nitrogen bulk concentration levels exceeded 0.5 wt%, a duplex fcc-/(bcc-bct-) Fe microstructure resulted that is iron carbide- and nitride-free. With increasing carbon and nitrogen concentrations, there was an increase in the retained fcc-Fe phase. In cooling rate studies, increasing carbon and nitrogen concentrations shifted the knee of the fcc-Fe-to-bcc-Fe phase time-temperature-transformation (T-T-T) curve to longer times. Hardness, compression strength, and wear resistance increased with increasing carbon and nitrogen concentrations and were superior to iron-carbon alloys without the nitrogen addition. C1 US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. Swiss Fed Inst Technol, Inst Met, Zurich, Switzerland. RP Rawers, J (reprint author), US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. NR 28 TC 2 Z9 2 U1 0 U2 1 PU CONSULTANTS BUREAU PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1064-7562 J9 J MATER SYNTH PROCES JI J. Mater. Synth. Process PD SEP PY 1999 VL 7 IS 5 BP 311 EP 319 DI 10.1023/A:1021877121902 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 401GM UT WOS:000166919900007 ER PT J AU Percus, OE Percus, JK AF Percus, OE Percus, JK TI Island length distribution in genome sequencing SO JOURNAL OF MATHEMATICAL BIOLOGY LA English DT Article DE genome; sequencing; island; ocean; distribution ID MATHEMATICAL-ANALYSIS; RANDOM CLONES AB We consider the general problem of constructing a physical map of a genome by welding islands of overlapping clones. Both distribution of clone length and non-uniform probability of overlap detection are taken into account, the latter restricted to the Markov case in which only the location of the end of the developing island is required. Exact results for the distribution of island length are obtained in the special cases of fixed clone length or rigid overlap criterion, and mean and variance for the general situation. Determination of ocean length distribution permits island number and contig number distributions to be found as well. C1 Santa Fe Inst, Santa Fe, NM 87501 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Sci, Los Alamos, NM USA. NYU, Courant Inst Math Sci, New York, NY 10012 USA. RP Percus, OE (reprint author), Santa Fe Inst, Santa Fe, NM 87501 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0303-6812 J9 J MATH BIOL JI J. Math. Biol. PD SEP PY 1999 VL 39 IS 3 BP 244 EP 268 DI 10.1007/s002850050170 PG 25 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 242DP UT WOS:000082923200003 PM 10501922 ER PT J AU Liang, L Feng, XD Peurrung, L Viswanathan, V AF Liang, L Feng, XD Peurrung, L Viswanathan, V TI Temperature-sensitive membranes prepared by UV photopolymerization of N-isopropylacrylamide on a surface of porous hydrophilic polypropylene membranes SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE temperature-sensitive membrane; polyN-isopropylacrylamide; microfiltration; ultrafiltration; membrane preparation and structure ID GELS; SEPARATION; MACHINES; PH AB Novel multifunctional membranes were prepared by ultraviolet photopolymerization of N-isopropylacrylamide (NIPAAm) on the surface of porous hydrophilic polypropylene microfiltration membranes. The polyN-isopropylacrylamide PNIPAAm gels were generated on the surface of the membrane through a covalent bond in the presence of a crosslinking agent, N,N'-methylenebisacrylamide. The crosslinked PNIPAAm gels are temperature-responsive hydrogels that can swell and deswell reversibly in aqueous solution around the vicinity of the lower critical solution temperature (LCST) of PNIPAAm. With a change of temperature, the effective pore size of the membrane surface can be enlarged or shrunk as the PNIPAAm gels swell or deswell. Above the LCST of PNIPAAm, the fluxes of water and solution containing 500 ppm of dextran (molecular weight: 1.67 x 10(5) g/mol) through the temperature-sensitive membranes are about 6 and 85 times higher than those below the LCST of PNIPAAm, respectively. The changeable flux makes it possible to employ the temperature-sensitive membranes as a sensor or valve that regulates filtration properties by responding to temperature. Solutions of dextran with a molecular weight from 6300 to 2,000,000 were used to evaluate the separation performance of the temperature-sensitive membranes as the ultrafiltration membrane. The ranges of rejection of dextran and the flux of solution are from 0 to 90 and 8 to 32 l/m(2) h, respectively, depending on the temperature, pressure, and molecular weight of dextran. It is clear that the temperature-sensitive membrane exhibits multifunctional characteristics; that is, the microfiltration membrane is above the LCST of PNIPAAm, and the ultrafiltration membrane is below the LCST of PNIPAAm. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Liang, L (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999,Mail Stop K6-24, Richland, WA 99352 USA. NR 34 TC 84 Z9 97 U1 1 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD SEP 1 PY 1999 VL 162 IS 1-2 BP 235 EP 246 DI 10.1016/S0376-7388(99)00145-3 PG 12 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 233UK UT WOS:000082445500023 ER PT J AU Tobin, KJ Onstott, TC DeFlaun, MF Colwell, FS Fredrickson, J AF Tobin, KJ Onstott, TC DeFlaun, MF Colwell, FS Fredrickson, J TI In situ imaging of microorganisms in geologic material SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE propidium iodide; phosphor imaging; petrographic thin section ID COASTAL-PLAIN; BACTERIA; SEDIMENTS; ENUMERATION; DENSITY; SAMPLES AB In order to fully delineate the interactions of microorganisms with geological substrates, unequivocal identification of intact microbial cells within geologic samples is required without the disruption of either the rock texture or the relationship of the microorganisms to the mineral fabric. To achieve this objective we developed a protocol that enables the visualization of intact microbial cells in petrographic thin sections, avoids detaching the cells from their host mineral surfaces and avoids microbial contamination during the lapidary process. Propidium iodide and POPO-3, nucleic acid stains that specifically target double-stranded DNA and RNA were utilized for in situ visualization of cells in surface and subsurface basalts from northeastern Idaho. Additionally, examination of samples incubated with acetic acid-UL-C-14 via phosphor imagining facilitated the in situ visualization of C-14 labeled biomass. Biomass observed was low(<10(7) cells/g). These observations indicate that the microbial distribution in these rocks exhibits a high degree of spatial heterogeneity at the sub-centimeter scale. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Envirogen Inc, Princeton Res Ctr, Lawrenceville, NJ 08648 USA. Idaho Natl Engn & Environm Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Tobin, KJ (reprint author), Univ Illinois, Dept Earth & Environm Sci, M-C 186,845 W Taylor St, Chicago, IL 60607 USA. NR 23 TC 17 Z9 19 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD SEP PY 1999 VL 37 IS 3 BP 201 EP 213 DI 10.1016/S0167-7012(99)00044-5 PG 13 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 229KT UT WOS:000082194300001 PM 10480264 ER PT J AU Mazumder, R Phelps, TJ Krieg, NR Benoit, RE AF Mazumder, R Phelps, TJ Krieg, NR Benoit, RE TI Determining chemotactic responses by two subsurface microaerophiles using a simplified capillary assay method SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE microaerophilic; simplified capillary chemotaxis assay; subsurface; swarm plate assay ID ESCHERICHIA-COLI; PSEUDOMONAS-AERUGINOSA; BACTERIAL CHEMOTAXIS; AROMATIC-COMPOUNDS; MOTILITY; ACIDS AB A simplified capillary chemotaxis assay utilizing a hypodermic needle, syringe, and disposable pipette tip was developed to measure bacterial tactic responses. The method was applied to two strains of subsurface microaerophilic bacteria. This method was more convenient than the Adler method and required less practice. Isolate VT10 was a strain of Pseudomonas syringae, which was isolated from the shallow subsurface. It was chemotactically attracted toward dextrose, glycerol, and phenol, which could be used as sole carbon sources, and toward maltose, which could not be used. Isolate MR100 was phylogenetically related to Pseudomonas mendocina and was isolated from the deep subsurface. It showed no tactic response to these compounds, although, it could use dextrose, maltose, and glycerol as carbon sources. The chemotaxis results obtained by the new method were verified by using the swarm plate assay technique. The simplified technique may be useful for routine chemotactic testing. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Biol, Blacksburg, VA 24061 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Benoit, RE (reprint author), Virginia Polytech Inst & State Univ, Dept Biol, Blacksburg, VA 24061 USA. RI phelps, tommy/A-5244-2011 NR 37 TC 27 Z9 33 U1 3 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD SEP PY 1999 VL 37 IS 3 BP 255 EP 263 DI 10.1016/S0167-7012(99)00072-X PG 9 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 229KT UT WOS:000082194300006 PM 10480269 ER PT J AU Schepkin, VD Choy, IO Budinger, TF Young, JN DeCampli, WM AF Schepkin, VD Choy, IO Budinger, TF Young, JN DeCampli, WM TI Multi-dose crystalloid cardioplegia preserves intracellular sodium homeostasis in myocardium SO JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY LA English DT Article DE intracellular sodium; cardioplegia; NMR; triple-quantum filtering ID ISOLATED RAT-HEART; NUCLEAR-MAGNETIC-RESONANCE; VENTRICULAR-FIBRILLATION; SHIFT-REAGENT; P-31 NMR; NA+; ISCHEMIA; NA-23; EXCHANGE; ARREST AB The goal of this study was to assess the effect of multi-dose St Thomas cardioplegia on intracellular sodium homeostasis in a rat heart model. A new magnetic resonance method was applied which enable us to detect intracellular Na changes without chemical shift reagents. Three groups of isolated rat hearts were subjected to 51 min of ischemia and 51 min of reperfusion at 37 degrees C: Group 1-three infusions of St Thomas cardioplegia every 17 min for 2 min (n = 7); Group 2-single-dose infusion of cardioplegia at the beginning of stop-flow ischemia (n = 8); and Group 3-clamp ischemia (n = 3) without cardioplegia administration. Performance of the heart was assessed by rate-pressure product relative to the pre-ischemic level (RPP). An NMR method was applied which continuously detects the Na-i concentration in the heart, using the ability of bound sodium to exhibit triple-quantum transitions and the growth of the corresponding signal when sodium ions pass from extracellular to intracellular space. Clamp ischemia without cardioplegia and 50 min of reperfusion left the heart dysfunctional. with Na-i growth from the pre-ischemic level of 13.9 +/- 1.2 mM to 34.9 +/- 1.3 mM and 73,9 +/- 1.9 mM at the end of ischemia and reperfusion. respectively. During single-dose cardioplegia the corresponding values for Na-i were 30.2 +/- 1 mM and 48.5 +/- 1.7 mM (RPP = 29%). Multiple infusions of cardioplegic solution resulted in a remarkable preservation of the heart's intracellular Na concentration with a non-significant increase in Na-i during ischemia and only 16.7 +/- 1 mM, (P = 0.01), after subsequent reperfusion (RPP = 85%). The time course of Na-i changes in the rat heart model demonstrates a prominent potential of multi-dose St Thomas' cardioplegia in preserving intracellular sodium homeostasis at 37 degrees C. The growth of Na-i concentration during ischemia, as an indicator of the viability of the myocytes, can reperfusion. have a prognostic value for the heart's performance during (C) 1999 Academic Press. C1 Univ Illinois, Biomed Magnet Resonance Lab, Urbana, IL 61801 USA. Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA USA. Childrens Hosp Oakland, Div Cardiothorac Surg, Oakland, CA 94609 USA. Beth Israel Med Ctr, Dept Pediat Cardiac Surg, Newark, NJ USA. RP Schepkin, VD (reprint author), Univ Illinois, Biomed Magnet Resonance Lab, Urbana, IL 61801 USA. RI Schepkin, Victor/A-1245-2007 FU NCRR NIH HHS [P41-RR05964] NR 38 TC 5 Z9 5 U1 1 U2 1 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2828 EI 1095-8584 J9 J MOL CELL CARDIOL JI J. Mol. Cell. Cardiol. PD SEP PY 1999 VL 31 IS 9 BP 1643 EP 1651 DI 10.1006/jmcc.1999.1002 PG 9 WC Cardiac & Cardiovascular Systems; Cell Biology SC Cardiovascular System & Cardiology; Cell Biology GA 231XG UT WOS:000082336200006 PM 10471348 ER PT J AU Goldstein, B Coombs, D He, XY Pineda, AR Wofsy, C AF Goldstein, B Coombs, D He, XY Pineda, AR Wofsy, C TI The influence of transport on the kinetics of binding to surface receptors: application to cells and BIAcore SO JOURNAL OF MOLECULAR RECOGNITION LA English DT Article DE biosensor; BIAcore; effective rates; reaction-diffusion-convection; dextran layer; soluble receptors ID MASS-TRANSPORT; LIGAND-BINDING; RATE CONSTANTS; DIFFUSION; DISSOCIATION; BIOSENSOR; ANTIBODY AB Accurate estimation of biomolecular reaction rates from binding data, when ligands in solution bind to receptors on the surfaces of cells or biosensors, requires an understanding of the contributions of both molecular transport and reaction. Efficient estimation of parameters requires relatively simple models. In this review, we give conditions under which various transport effects are negligible and identify simple binding models that incorporate the effects of transport, when transport cannot be neglected. We consider effects of diffusion of ligands to cell or biosensor surfaces, flow in a BIAcore biosensor, and distribution of receptors in a dextran layer above the sensor surface. We also give conditions under which soluble receptors can be expected to compete effectively with surface-bound receptors, Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Univ Calif Los Alamos Natl Lab, Theoret Biol & Biophys Grp, Div Theoret, Los Alamos, NM 87545 USA. Univ Arizona, Program Appl Math, Tucson, AZ 85721 USA. Univ Calif Los Alamos Natl Lab, Complex Syst Grp, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Math & Stat, Albuquerque, NM 87131 USA. OI Coombs, Daniel/0000-0002-8038-6278 FU NIGMS NIH HHS [GM35556] NR 23 TC 61 Z9 62 U1 0 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0952-3499 J9 J MOL RECOGNIT JI J. Mol. Recognit. PD SEP-OCT PY 1999 VL 12 IS 5 BP 293 EP 299 DI 10.1002/(SICI)1099-1352(199909/10)12:5<293::AID-JMR472>3.0.CO;2-M PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 263DV UT WOS:000084108400004 PM 10556877 ER PT J AU Vanheusden, K Warren, WL Devine, RAB Fleetwood, DM Draper, BL Schwank, JR AF Vanheusden, K Warren, WL Devine, RAB Fleetwood, DM Draper, BL Schwank, JR TI A non-volatile MOSFET memory device based on mobile protons in SiO2 thin films SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT Conference on Amorphous and Crystalline Insulating Thin Films II CY OCT 12-14, 1998 CL SHAW COLL CHINESE UNIV HONG KONG, SHAW, HONG KONG SP Shaw Coll Chinese Univ Hong Kong, Hong Kong Chapter Mat Res Soc, Croucher Fdn Hong Kong, Asian Off USAF HO SHAW COLL CHINESE UNIV HONG KONG ID INTERFACE STATES; DEFECTS; MECHANISM; KINETICS; HYDROGEN; BUILDUP AB It is shown how mobile H+ ions can be generated thermally inside the oxide layer of Si/SiO2/Si structures. The technique involves only standard silicon processing steps: the non-volatile field effect transistor (NVFET) is based on a standard MOSFET with thermally grown SiO2 capped with a poly-silicon layer. The capped thermal oxide receives an anneal at similar to 1100 degrees C that enables the incorporation of the mobile protons into the gate oxide. The introduction of the protons is achieved by a subsequent 500-800 degrees C anneal in a hydrogen-containing ambient, such as forming-gas (N-2 : H-2 95:5). The mobile protons are stable and entrapped inside the oxide layer, and unlike alkali ions, their space-charge distribution can be controlled and rearranged at room temperature by an applied electric field. Using this principle, a standard metal-oxide-semiconductor (MOS) transistor can be converted into a non-volatile memory transistor that can be switched between 'normally on' and 'normally off'. Switching speed, retention, endurance, and radiation tolerance data are presented showing that this non-volatile memory technology can be competitive with existing Si-based nonvolatile memory technologies such as the floating gate technologies (e.g. Flash memory). (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. France Telecom, Ctr Natl Etud Telecommun, F-38243 Meylan, France. RP Vanheusden, K (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 23 TC 5 Z9 5 U1 1 U2 4 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 SEP 1 PY 1999 VL 254 BP 1 EP 10 DI 10.1016/S0022-3093(99)00366-X PG 10 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 234ZH UT WOS:000082513900002 ER PT J AU Pantelides, ST Ramamoorthy, M AF Pantelides, ST Ramamoorthy, M TI Atomic-scale dynamics during silicon oxidation and the properties of defects at the Si-SiO2 interface SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT Conference on Amorphous and Crystalline Insulating Thin Films II CY OCT 12-14, 1998 CL SHAW COLL CHINESE UNIV HONG KONG, SHAW, HONG KONG SP Shaw Coll Chinese Univ Hong Kong, Hong Kong Chapter Mat Res Soc, Croucher Fdn Hong Kong, Asian Off USAF HO SHAW COLL CHINESE UNIV HONG KONG ID THERMAL DONOR FORMATION; OXYGEN DIFFUSION; MOLECULAR-DYNAMICS; POINT-DEFECTS; SI; ENERGY; MODEL AB We describe first-principles calculations in terms of which we arrive at a unified description of the atomic dynamics that underlie the nucleation and growth of SiO2 precipitates in Si and the oxidation of Si films. We identify the mechanism for the observed emission of Si interstitials and show that it eliminates electrically-active defects without introducing dangling bonds. The results provide an explanation for the low defect density at the Si-SiO2 interface and suggest a novel family of electrically-active interface defects that are akin to the 'thermal donors' in Si. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. EM pantelides@vanderbilt.edu NR 44 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP 1 PY 1999 VL 254 BP 38 EP 46 DI 10.1016/S0022-3093(99)00444-5 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 234ZH UT WOS:000082513900006 ER PT J AU Sagaradze, VV Lapin, SS Kirk, MA Goshchitskii, BN AF Sagaradze, VV Lapin, SS Kirk, MA Goshchitskii, BN TI Influence of high-dose Kr+ irradiation on structural evolution and swelling of 16Cr-15Ni-3Mo-1Ti aging steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID ALLOYS AB Austenitic (16Cr-15Ni-3Mo-1Ti, 16Cr-15Ni-3Mo) stainless steels have been exposed to Kr+ irradiation (E = 1.5 MeV, T-irr = 500-700 degrees C, dose - up to 200 dpa) to compare with fast neutron irradiation (E > 0.1 MeV, T-irr = 480-500 degrees C, dose - up to 60 dpa). Structural evolution, concentration changes and void formation were investigated. It was found that structural transformations in these steels are in qualitative agreement under Kr+ and fast neutron irradiation. High resistance to swelling of aging stainless steel with 1% Ti is explained by the presence of both indirect point-defect sinks (gamma' precipitates) and thermally stable direct dislocation sinks pinned by dispersed particles under irradiation. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Russian Acad Sci, Inst Met Phys, Ural Div, Ekaterinburg 620219, Russia. RP Kirk, MA (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Goshchitskii, Boris/K-4210-2013; Sagaradze, Victor/J-5570-2013 OI Goshchitskii, Boris/0000-0002-5292-1683; Sagaradze, Victor/0000-0002-6426-3382 NR 31 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1999 VL 274 IS 3 BP 287 EP 298 DI 10.1016/S0022-3115(99)00090-2 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 233UJ UT WOS:000082445400004 ER PT J AU Bruemmer, SM Simonen, EP Scott, PM Andresen, PL Was, GS Nelson, JL AF Bruemmer, SM Simonen, EP Scott, PM Andresen, PL Was, GS Nelson, JL TI Radiation-induced material changes and susceptibility to intergranular failure of light-water-reactor core internals SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID STRESS-CORROSION CRACKING; AUSTENITIC STAINLESS-STEEL; CR-NI ALLOYS; MICROSTRUCTURAL EVOLUTION; NEUTRON-IRRADIATION; DISPLACEMENT CASCADES; INDUCED SEGREGATION; MOLECULAR-DYNAMICS; SOLUTE SEGREGATION; TEMPERATURE AB Current understanding of radiation-induced material changes that occur in light-water-reactor (LWR) core components is critically reviewed and linked to intergranular failure processes. Although the basic science of radiation damage processes in metals is reasonably well established, accurate prediction of microstructures, microchemistries and mechanical property changes in complex stainless alloys during irradiation at LWR temperatures is not possible at present. Mechanistic understanding of these radiation-induced changes in commercial alloys is considered to be of paramount importance for the mitigation of the intergranular environmental cracking that occurs in service. Fundamental research is needed to define defect-solute interactions and microstructural evolution at intermediate temperatures and dose rates pertinent to LWRs where transient effects often dominate behavior. In addition, it is essential that radiation effects on matrix microstructure and microchemistry and grain boundary microchemistry be understood. Finally, a stronger emphasis on accurately quantifying radiation effects on environmental cracking mechanisms and kinetics is needed. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Framatome, F-92084 Paris La Def, France. GE, Corp Res & Dev, Schenectady, NY 12309 USA. Univ Michigan, Dept Nucl Engn, Ann Arbor, MI 48109 USA. Elect Power Res Inst, Palo Alto, CA 94303 USA. RP Bruemmer, SM (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 71 TC 144 Z9 145 U1 2 U2 49 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 SEP PY 1999 VL 274 IS 3 BP 299 EP 314 DI 10.1016/S0022-3115(99)00075-6 PG 16 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 233UJ UT WOS:000082445400005 ER PT J AU Lashley, JC Blau, MS Staudhammer, KP Pereyra, RA AF Lashley, JC Blau, MS Staudhammer, KP Pereyra, RA TI In situ purification, alloying and casting methodology for metallic plutonium SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Plutonium metal that has been double ER (electrorefined/electrorefining) was further purified via zone refining, using a floating molten zone to minimize the introduction of impurities. The temperature of the molten zone was 750 degrees C, and the atmosphere was 10(-5) Pa. A total of ten zone refining passes were made at a travel rate of 1.5 cm/h. There were 19 elements reduced to quantities below the minimum detectable limits (MDL) by zone refining, while P, K, and W were significantly reduced. The zone-refined metal was then used in an in situ distillation, alloying, and casting step to prepare tapered specimens for single-crystal growth experiments. Specifically, Am-241 was distilled from Pu metal by levitating Pu metal with 1 wt% Ga in the melt in a Crystallox vertical electromagnetic levitation crucible at 10(-5) Pa. The Pu is alloyed with Ga to stabilize the delta phase (fcc symmetry) upon solidification. The Pu was chill-cast directly from the electromagnetic levitation field into 1- cm tapered specimens. A water-cooled ceramic mold was used, and the Pu metal was cooled at a rate of 100 degrees C/min. A microstructure examination of the specimen showed 10 x 25 mu m acicular grains with a density of 15.938 g/cm(3) (+/- 0.002 g/cm(3)). (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lashley, JC (reprint author), Univ Calif Los Alamos Natl Lab, TA-3 SM 29 Mail Stop G 730, Los Alamos, NM 87545 USA. NR 13 TC 17 Z9 17 U1 4 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 SEP PY 1999 VL 274 IS 3 BP 315 EP 319 DI 10.1016/S0022-3115(99)00074-4 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 233UJ UT WOS:000082445400006 ER PT J AU Hirooka, Y Ashida, K Kugel, H Walsh, D Wampler, W Bell, M Conn, R Hara, M Luckhardt, S Matsuyama, M Mansfield, D Mueller, D Skinner, C Walters, T Watanabe, K AF Hirooka, Y Ashida, K Kugel, H Walsh, D Wampler, W Bell, M Conn, R Hara, M Luckhardt, S Matsuyama, M Mansfield, D Mueller, D Skinner, C Walters, T Watanabe, K TI Deposition of lithium on a plasma edge probe in TFTR. Behavior of lithium-painted walls interacting with edge plasmas SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 13th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 18-22, 1998 CL SAN DIEGO, CALIFORNIA SP Gen Atomics Co, US DOE ID DISCHARGES; GRAPHITE; TEMPERATURES; SURFACES; TOKAMAK AB Recent observations have indicated that lithium pellet injection wall conditioning plays an important role in achieving the enhanced supershot regime in TFTR (the tokamak test fusion reactor). However, little is understood about the behavior of lithium-coated limiter walls, interacting with edge plasmas. In the final campaign of TFTR, a cylindrical carbon fiber composite probe was inserted into the boundary plasma region and exposed to ohmically heated deuterium discharges with lithium pellet injection. The ion-drift side probe surface exhibits a sign of codeposition of lithium, carbon, oxygen, and deuterium, whereas the electron side essentially indicates high-temperature erosion. It is found that lithium is incorporated in these codeposits in the form of oxide at the concentration of a few percent. In the electron side, lithium has been found to penetrate deeply into the probe material, presumably via rapid diffusion through interplane spaces in the graphite crystalline. Though it is not conclusive, materials mixing in the carbon and lithium system appears to be a key process to successful lithium wall conditioning. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Toyama Univ, Toyama 930, Japan. Princeton Univ, Princeton, NJ 08543 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hirooka, Y (reprint author), Natl Inst Fus Sci, 322-6 Oroshi Cho, Toki, Japan. NR 28 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1999 VL 274 IS 3 BP 320 EP 328 DI 10.1016/S0022-3115(99)00053-7 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 233UJ UT WOS:000082445400007 ER PT J AU Onchi, T Hide, K Chung, HM AF Onchi, T Hide, K Chung, HM TI An Auger electron spectroscope analysis of thermally-sensitized type 304 stainless steels irradiated to low neutron fluences SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter ID STRESS-CORROSION CRACKING; MECHANICAL RESPONSE; WATER AB An Auger electron spectroscopy was used to examine grain boundary chromium depletion of the thermally-sensitized type 304 stainless steel (SS) irradiated to low neutron fluences. The chromium depletion was greater for 3 x 10(23) n/m(2) (E > 1 MeV) and moreover for 1 x 10(24) n/m(2) than that of the unirradiated SS, It is suggested that the thermally-sensitized SS is prone to be more sensitive to radiation induced segregation than the non-sensitized austenitic SS. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Cent Res Inst Elect Power Ind, Komae, Tokyo 2018511, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Onchi, T (reprint author), Cent Res Inst Elect Power Ind, 2-11-1 Iwado Kita, Komae, Tokyo 2018511, Japan. NR 11 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1999 VL 274 IS 3 BP 341 EP 344 DI 10.1016/S0022-3115(99)00118-X PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 233UJ UT WOS:000082445400010 ER PT J AU Kropp, J Eisenhut, M Ambrose, KR Knapp, FF Franke, WG AF Kropp, J Eisenhut, M Ambrose, KR Knapp, FF Franke, WG TI Pharmacokinetics and metabolism of the methyl-branched fatty acid (BMIPP) in animals and humans SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE BMIPP; fatty acid metabolism; mass spectrometry; Langendorff hearts ID SUBACUTE MYOCARDIAL-INFARCTION; RAT HEARTS; EMISSION TOMOGRAPHY; CANINE MYOCARDIUM; PENTADECANOIC ACID; WALL-MOTION; IODINE-123-BMIPP; KINETICS AB The aim of this study was to further characterize the major metabolite of 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP). Methods: Radioactive components of I-131-BMIPP were evaluated in Langendorff-perfused rat hearts, as well as in blood samples from 20 patients after injection of I-123-BMIPP. Rat hearts were perfused with pH 7.4 Krebs-Henseleit buffer with or without 0.4 mmol/L bovine serum albumin (BSA) or 0.4 mmol/L palmitate. Lipids were Folch extracted and hydrolyzed from samples of the outflow, as well as from homogenized hearts. Radioactive components were determined by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses. The major metabolite of BMIPP was then further characterized by electrospray mass spectrometry. Results: The rat heart perfusate showed one major polar metabolite observed by TLC (R-f = 0.35; solvent = benzene-dioxane-acetic acid 80:18:2). The addition of BSA/palmitate to the perfusate buffer significantly increased backdiffusion of BMIPP (R-f = 0.55), as well as reduced BMIPP uptake and metabolism. The major metabolite was identified by mass spectral analysis as 2-(p-iodophenyl)acetic acid (IPC2). From TLC and HPLC analyses of the serum lipids obtained from patients, the same metabolite could be identified with levels increasing over time (0%, 5.2% and 11.8% of the injected dose; 3 min, 20 min and 3 h postinjection, respectively). In addition to the identification of unmetabolized BMIPP (53.9%), the rat heart lipid hydrolysate also contained alpha-methyl-14-(p-iodophenyl)tetradecanoic acid (20.8%), 12-(p-iodophenyl)-substituted-dodecanoic (17.1%), -hexanoic acid (5.2%) and IPC2 (1.1%). Conclusion: The animal results show the complexity of uptake, metabolism and release of BMIPP from which a part is metabolized through alpha- and subsequent beta-oxidation to the final IPC2 metabolite as confirmed by mass spectral analysis. The results from patient studies suggest that the slow myocardial washout observed in vivo after intravenous administration of BMIPP may represent a similar process, because both unmetabolized BMIPP and the final metabolite were also identified in serum samples. C1 Univ Dresden, Dept Nucl Med, Dresden, Germany. Univ Heidelberg, Dept Nucl Med, Heidelberg, Germany. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. RP Kropp, J (reprint author), Klin Nukl Med, Fetscherstr 74, D-01307 Dresden, Germany. NR 39 TC 8 Z9 9 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1999 VL 40 IS 9 BP 1484 EP 1491 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 234ZU UT WOS:000082514900016 PM 10492369 ER PT J AU Zimmerman, BE Cessna, JT Unterweger, MP Li, AN Whiting, JS Knapp, FFR AF Zimmerman, BE Cessna, JT Unterweger, MP Li, AN Whiting, JS Knapp, FFR TI A new experimental determination of the dose calibrator setting for Re-188 SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE dose calibrators; Re-188 ID HALF-LIFE AB Accurate activity measurements of radionuclides using commercial dose calibrators requires that the correct dial setting (or calibration factor) be applied. The dose calibrator setting for the medical radionuclide Re-188 (as (ReO4-)-Re-188) has been determined experimentally using solution sources prepared and calibrated at the National Institute of Standards and Technology (NIST). Methods: The specific activity of two sources (in units of MBq/g) in the standard 5-mL NIST ampoule and in a 5-mL SoloPak dose vial were calibrated using 4 pi beta liquid scintillation counting with H-3-standard efficiency tracing and gamma-ray/bremmstrahlung counting in the NIST "4 pi" gamma ionization chamber on gravimetrically related sources. Results: The newly determined settings for the NIST Capintec CRC-12 dose calibrator are (631 +/- 4) x 10 and (621 +/- 3) x 10 for the respective ampoule and dose vial geometries with an expanded (at a presumed 95% confidence level) uncertainty of 0.4%-0.5% in the activity determination. The setting for the dose vial geometry was independently confirmed using a Capintec CRC-15R at Cedars-Sinai Medical Center using sources calibrated against a NIST standard. Conclusion: These new settings result in activity readings 28%-30% lower than those obtained using the previously recommended setting of 496 x 10. This discrepancy most likely results from underestimating the total radiation yield from Re-188 decay when calculating the dose calibrator response. This study emphasizes the need for experimental determinations of dose calibrator settings in the geometry in which the measurements will be performed. C1 Natl Inst Stand & Technol, Phys Lab, Gaithersburg, MD 20899 USA. Cedars Sinai Med Ctr, Dept Med Phys & Imaging, Los Angeles, CA 90048 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN USA. RP Zimmerman, BE (reprint author), Natl Inst Stand & Technol, Phys Lab, Bldg 245,Rm C114, Gaithersburg, MD 20899 USA. NR 23 TC 14 Z9 15 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1999 VL 40 IS 9 BP 1508 EP 1516 PG 9 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 234ZU UT WOS:000082514900020 PM 10492373 ER PT J AU Mardirossian, G Tagesson, M Blanco, P Bouchet, LG Stabin, M Yoriyaz, H Baza, S Ljungberg, M Strand, SE Brill, AB AF Mardirossian, G Tagesson, M Blanco, P Bouchet, LG Stabin, M Yoriyaz, H Baza, S Ljungberg, M Strand, SE Brill, AB TI A new rectal model for dosimetry applications SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE reference man; human phantom; modeling; Monte Carlo simulation; S values ID PROSTATE; CARCINOMA; IRRADIATION AB A revised geometric representative model of the lower part of the colon, including the rectum, the urinary bladder and prostate, is proposed for use in the calculation of absorbed dose from injected radiopharmaceuticals. The lower segment of the sigmoid colon as described in the 1987 Oak Ridge National Laboratory mathematical phantoms does not accurately represent the combined urinary bladder/rectal/prostate geometry. In the revised model in this study, the lower part of the abdomen includes an explicitly defined rectum. The shape of sigmoid colon is more anatomically structured, and the diameters of the descending colon are modified to better approximate their true anatomic dimensions. To avoid organ overlap and for more accurate representation of the urinary bladder and the prostate gland tin the male), these organs are shifted from their originally defined positions. The insertion of the rectum and the shifting of the urinary bladder will not overlap with or displace the female phantom's ovaries or the uterus. In the adult male phantom, the prostatic urethra and seminal duct are also included explicitly in the model. The relevant structures are defined for the newborn and 1-, 5-, 10- and 15-y-old (adult female) and adult male phantoms. Methods: Values of the specific absorbed fractions and radionuclide S values were calculated with the SIMDOS dosimetry package. Results for (99m)Tc and other radionuclides are compared with previously reported values. Results: The new model was used to calculate S values that may be crucial to calculations of the effective dose equivalent. For (131)I, the S (prostate <-- urinary bladder contents) and S (lower large intestine [LLI] wall <-- urinary bladder contents) are 6.7 x 10(-6) and 3.41 x 10(-6) mGy/MBq x s, respectively. Corresponding values given by the MIRDOSE3 computer program are 6.23 x 10(-6) and 1.53 x 10-6 mGy/MBq x s, respectively. The value of S (rectum wall <-- urinary bladder contents) is 4.84 x 10(-5) mGy/MBq x s. For 99mTc, we report S (testes <-- prostate) and S (LLI wall <-- prostate) of 9.41 x 10(-7) and 1.53 x 10-7 mGy/MBq x s versus 1.33 x 10(-6) and 7.57 x 10(-6) mGy/MBq x s given by MIRDOSE3, respectively. The value of S (rectum wall <-- prostate) for 99mTc is given as 4.05 X 10(-6) mGy/MBq x s in the present model, Conclusion: The new revised rectal model describes an anatomically realistic lower abdomen region, thus giving improved estimates of absorbed dose. Due to shifting the prostate gland, a 30%-45% reduction in the testes dose and the insertion of the rectum leads to 48%-55% increase in the LLI wall dose when the prostate is the source organ. C1 Univ Massachusetts, Med Ctr, Dept Nucl Med, Worcester, MA 01655 USA. Lund Univ, Dept Radiat Phys, S-22101 Lund, Sweden. Univ Florida, Dept Nucl & Radiobiol Engn, Gainesville, FL USA. Oak Ridge Inst Sci & Educ, Div Med Sci, Oak Ridge, TN USA. Aleppo Univ, Fac Sci, Aleppo, Syria. IPEN, Sao Paulo, Brazil. RP Mardirossian, G (reprint author), Univ Massachusetts, Med Ctr, Dept Nucl Med, 55 Lake Ave N, Worcester, MA 01655 USA. RI Yoriyaz, Helio/K-1874-2012 OI Yoriyaz, Helio/0000-0003-4023-236X NR 15 TC 22 Z9 22 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1999 VL 40 IS 9 BP 1524 EP 1531 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 234ZU UT WOS:000082514900022 PM 10492375 ER PT J AU Zangar, RC Okita, JR Kim, H Thomas, PE Anderson, A Edwards, RJ Springer, DL Okita, RT AF Zangar, RC Okita, JR Kim, H Thomas, PE Anderson, A Edwards, RJ Springer, DL Okita, RT TI Effect of calcium channel antagonists nifedipine and nicardipine on rat cytochrome P-4502B and 3A forms SO JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS LA English DT Article ID IN-VITRO; DRUG-INTERACTIONS; LIVER-MICROSOMES; 2E1 EXPRESSION; MESSENGER-RNA; IDENTIFICATION; METABOLISM; HEPATOCYTES; OXIDATION; DILTIAZEM AB Calcium channel antagonists am widely prescribed for treatment of hypertension. In this study, we examined whether treatment with the calcium channel antagonists, nicardipine, nifedipine or diltiazem, alters cytochrome P-450 2B or 3A (CYP2B or CYP3A, respectively) expression in rat liver. Western blot analyses were undertaken using antibodies specific for one or several members of these cytochrome P-450 subfamilies. Nicardipine was found to be an effective inducer of CYP3A; in particular, CYP3A23 was increased similar to 36-fold following treatment with 100 mg of nicardipine/kg/day. Nicardipine induced CYP2B forms up to similar to 3.1-fold. Nifedipine did not alter CYP3A expression but did increase CYP2B expression such that total CYP2B, CYP2B1, and CYP2B2v (a splice variant of CYP2B2) were increased similar to 5- to 15-fold after treatment with 100 mg of nifedipine/kg/day, with increases in benzyloxyresorufin O-dealkylase and erythromycin N-demethylase activities, respectively. The distinct differences in cytochrome P-450 induction profile induced by nicardipine and nifedipine suggest that they may enhance cytochrome P-450 expression by different mechanisms unrelated to their effects on calcium channels. C1 Washington State Univ, Coll Pharm, Pullman, WA 99164 USA. Pacific NW Natl Lab, Richland, WA USA. Wayne State Univ, Detroit, MI USA. Rutgers State Univ, Piscataway, NJ USA. Hotel Dieu, Ctr Rech, Quebec City, PQ, Canada. Univ London Imperial Coll Sci Technol & Med, Sch Med, London, England. RP Okita, RT (reprint author), Washington State Univ, Coll Pharm, 105 Wegner Hall,POB 646510, Pullman, WA 99164 USA. FU NIEHS NIH HHS [ES 03771] NR 36 TC 13 Z9 15 U1 0 U2 1 PU AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0022-3565 J9 J PHARMACOL EXP THER JI J. Pharmacol. Exp. Ther. PD SEP PY 1999 VL 290 IS 3 BP 1436 EP 1441 PG 6 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 228GM UT WOS:000082128800062 PM 10454523 ER PT J AU Munchow, A Weingartner, TJ Cooper, LW AF Munchow, A Weingartner, TJ Cooper, LW TI The summer hydrography and surface circulation of the east Siberian shelf Sea SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID DENSE WATER FORMATION; ARCTIC-OCEAN; CHUKCHI SEAS; COASTAL CURRENT; FRESH-WATER; EDDY FIELDS; ICE; SALINITY; HALOCLINE; DRIFTERS AB During the ice-free summer season in 1995 the authors deployed and subsequently tracked 39 surface drifters to test the hypothesis that the discharge from the Kolyma River forces a buoyancy-driven coastal current from the East Siberian Sea toward Bering Strait. The observed mean flow is statistically significant at the 95% level of confidence, but ifs direction contradicts their initial hypothesis. Instead of a coastally trapped eastward how, the authors find a laterally sheared westward flow with maximum velocities offshore that correlate only weakly with the local winds. At a daily, wind-dominated timescale the drifter data reveal spatially coherent flows of up to 0.5 m s(-1). The Lagrangian autocorrelation scale is about 3 days and the Lagrangian eddy length scale reaches 40 km. This spatial scale exceeds the nearshore internal deformation radius by a factor of 3; however, it more closely corresponds to the internal deformation radius associated with the offshore ice edge. Bulk estimates of the horizontal mixing coefficient resemble typical values of isotropic open ocean dispersion at midlatitudes. Hydrographic observations and oxygen isotope ratios of seawater indicate a low proportion of riverine freshwater relative to sea ice melt in most areas of the East Siberian Sea except close to the Kolyma Delta. The observations require a reevaluation of the conceptual view of the summer surface circulation of the East Siberian Sea. Eastward buoyancy-driven coastal currents do not always form on this shelf despite large river discharge. Instead, ice melt waters of a retreating ice edge act as a line source of buoyancy that in 1995 forced a westward surface flow in the East Siberian Sea. C1 Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Munchow, A (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, 71 Dudley Rd, New Brunswick, NJ 08901 USA. RI Cooper, Lee/E-5251-2012; Muenchow, Andreas/J-8257-2012; OI Cooper, Lee/0000-0001-7734-8388; Muenchow, Andreas/0000-0001-8360-5686 NR 55 TC 33 Z9 35 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1999 VL 29 IS 9 BP 2167 EP 2182 DI 10.1175/1520-0485(1999)029<2167:TSHASC>2.0.CO;2 PG 16 WC Oceanography SC Oceanography GA 246EC UT WOS:000083150600004 ER PT J AU Dukowicz, JK Greatbatch, RJ AF Dukowicz, JK Greatbatch, RJ TI The bolus velocity in the stochastic theory of ocean turbulent tracer transport SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CIRCULATION MODELS; EDDY; PARAMETERIZATION AB A stochastic theory of tracer transport in compressible turbulence has recently been developed and then applied to the ocean case because stratified flow in isopycnal coordinates is analogous to compressible now with the isopycnal layer thickness playing the role of density. The results generalize the parameterization of cent and McWilliams in the sense that the eddy-induced transport velocity (i.e., the bolus velocity, which is directly related to the thickness-velocity correlation) is given by downgradient Fickian diffusion of thickness with a general mixing tensor K. This result is however dependent on an imprecise postulate relating the Lagrangian to the Eulerian mean velocities. In this paper the authors show that this postulate is unnecessary in a certain flow regime. This regime exists whenever the effect of thickness-velocity correlations dominates over the effect of relative vorticity-velocity correlations. The primary example is planetary geostrophic turbulence, but it may also exist in homogeneous quasigeostrophic turbulence. The bolus velocity is modified and becomes equivalent to upgradient diffusion of potential vorticity along isopycnals with the same mixing tensor K. This changes the conceptual basis of the bolus velocity parameterization of Gent and McWilliams at least in this regime, but practically, the effective change is of rather small magnitude. C1 Los Alamos Natl Lab, Div Theoret, Grp T3, Los Alamos, NM 87545 USA. Dalhousie Univ, Dept Oceanog, Halifax, NS, Canada. RP Dukowicz, JK (reprint author), Los Alamos Natl Lab, Div Theoret, Grp T3, Mail Stop B216, Los Alamos, NM 87545 USA. EM duk@lanl.gov NR 19 TC 11 Z9 11 U1 3 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1999 VL 29 IS 9 BP 2232 EP 2239 DI 10.1175/1520-0485(1999)029<2232:TBVITS>2.0.CO;2 PG 8 WC Oceanography SC Oceanography GA 246EC UT WOS:000083150600008 ER PT J AU Bryan, K Dukowicz, JK Smith, RD AF Bryan, K Dukowicz, JK Smith, RD TI On the mixing coefficient in the parameterization of bolus velocity SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GLOBAL OCEAN CIRCULATION; MESOSCALE TRACER TRANSPORTS; HEAT-TRANSPORT; BETA-PLANE; EDDIES; MODELS; ATLANTIC; FLOW AB Mesoscale eddies in the ocean play an important role in the ocean circulation. In order to simulate the ocean circulation, mesoscale eddies must be included explicitly or parameterized. The eddy permitting calculations of the Los Alamos ocean circulation model offer a special opportunity to test aspects of parameterizations that have recently been proposed. Although the calculations are for a model in level coordinates, averages over a five-year period have been carried out by interpolating to instantaneous isopycnal surfaces. The magnitude of "thickness mixing" or bolus velocity is found to coincide with areas of intense mesoscale activity in the western boundary currents of the Northern Hemisphere and the Antarctic Circumpolar Current. The model also predicts relatively large bolus fluxes in the equatorial region. The analysis does show that the rotational component of the bolus velocity is significant. Predictions of the magnitude of the bolus velocity, assuming downgradient mixing of thickness with various mixing coefficients, have been compared directly with the model. The coefficient proposed by Held and Larichev provides a rather poor fit to the model results because it predicts large bolus velocity magnitudes at high latitudes and in other areas in which there is only a small amount of mesoscale activity. A much better fit is obtained using a constant mixing coefficient or a mixing coefficient originally proposed by Stone in a somewhat different context. The best fit to the model is obtained with a coefficient proportional to lambda(2)/T, where lambda is the radius of deformation, and T is the Eady timescale for the growth of unstable baroclinic waves. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Bryan, K (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. NR 28 TC 54 Z9 54 U1 3 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1999 VL 29 IS 9 BP 2442 EP 2456 DI 10.1175/1520-0485(1999)029<2442:OTMCIT>2.0.CO;2 PG 15 WC Oceanography SC Oceanography GA 246EC UT WOS:000083150600021 ER PT J AU Bleicher, M Zabrodin, E Spieles, C Bass, SA Ernst, C Soff, S Bravina, L Belkacem, M Weber, H Stocker, H Greiner, W AF Bleicher, M Zabrodin, E Spieles, C Bass, SA Ernst, C Soff, S Bravina, L Belkacem, M Weber, H Stocker, H Greiner, W TI Relativistic hadron-hadron collisions in the ultra-relativistic quantum molecular dynamics model SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID HEAVY-ION COLLISIONS; STRANGE-PARTICLE-PRODUCTION; NONEQUILIBRIUM PROCESSES; NUCLEAR COLLISIONS; CHARGED-PARTICLES; TRANSPORT-THEORY; PP INTERACTIONS; GEV-C; ENERGIES; FRAGMENTATION AB Hadron-hadron (h-h) collisions at high energies are investigated in the ultra-relativistic quantum molecular dynamics (UrQMD) approach. This microscopic transport model describes the phenomenology of hadronic interactions at low and intermediate energies (root s < 5 GeV) in terms of interactions between known hadrons and their resonances. At higher energies, root s > 5 GeV, the excitation of colour strings and their subsequent fragmentation into hadrons dominates the multi pie production of particles in the UrQMD model. The model shows a fair overall agreement with a large body of experimental h-h data over a wide range of h-h centre-of-mass energies. Hadronic reaction data with higher precision would be useful to support the use of the UrQMD model for relativistic heavy-ion collisions. C1 Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Duke Univ, Dept Phys, Durham, NC 27708 USA. Moscow State Univ, Inst Nucl Phys, Moscow 119899, Russia. Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. RP Bleicher, M (reprint author), Univ Frankfurt, Inst Theoret Phys, Robert Mayer Str 8, D-60054 Frankfurt, Germany. RI Bleicher, Marcus/A-2758-2010; Stoecker, Horst/D-6173-2013; OI Stoecker, Horst/0000-0002-3282-3664; Bass, Steffen/0000-0002-9451-0954 NR 81 TC 644 Z9 654 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 1999 VL 25 IS 9 BP 1859 EP 1896 DI 10.1088/0954-3899/25/9/308 PG 38 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 241BL UT WOS:000082862100012 ER PT J AU Weber, F AF Weber, F TI Quark matter in neutron stars SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Review ID HEAVY-ION COLLISIONS; SUPER-HYPERNUCLEI; PHASE-TRANSITION; NUCLEAR-MATTER; SHELL MODEL; FINITE TEMPERATURES; HADRONIC MATTER; KAON PRODUCTION; STRANGE STARS; BARYON AB Neutron stars, spotted as pulsars by radio telescopes and x-ray satellites, contain matter up to ten times denser than atomic nuclei, thus providing a high-pressure environment in which numerous subatomic particle processes are expected to compete with each other and novel phases of matter-like the quark-gluon plasma being sought at the most powerful terrestrial particle colliders-could exist. This article aims at exploring the possible existence of quark matter inside neutron stars and pointing out the fingerprints by means of which this novel phase of matter could register itself in the observed pulsar data. The detection of such matter in neutron stars would help to clarify how quark matter behaves, and give a boost to theories about the early universe as well as laboratory searches for the production of quark matter in heavy-ion colliders. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Weber, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Nucl Sci, MS-70A-3307, Berkeley, CA 94720 USA. NR 95 TC 22 Z9 22 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 1999 VL 25 IS 9 BP R195 EP R229 DI 10.1088/0954-3899/25/9/201 PG 35 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 241BL UT WOS:000082862100004 ER PT J AU Patterson, CW Hanson, D Redondo, A Scott, SL Henson, N AF Patterson, CW Hanson, D Redondo, A Scott, SL Henson, N TI Conformational analysis of the crystal structure for MDI/BDO hard segments of polyurethane elastomers SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE atomistic modeling; conformational analysis; hard segments; polyurethane elastomer; X-ray diffraction ID X-RAY-DIFFRACTION; MICRODOMAIN STRUCTURE; MDI; SCATTERING AB From conformational analysis, we have determined the two lowest energy crystal structures for the hard segments of 4,4'-diphenylmethane diisocyanate/1,4-butanediol (MDI/BDO)-based polyurethane elastomer. Both crystal form, (1), there is strong hydrogen bonding between linear chains with a density of 1.30 g/cm(3), while in the other form (2), van der Waals bonding gives rise to a double helix structure with a density of 1.22 g/cm(3) and a formation energy 1.6 kJ/mol higher than form (1). The double helix crystal has a unit cell length of 18.8 Angstrom which is about half the 34.7 Angstrom unit cell length of the hydrogen-bonded crystal. The X-ray diffraction predicted for each crystal is presented and compared with experiment. (C) 1999 John Wiley & Sons, Inc. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RP Redondo, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RI He, Yong/F-8752-2012 NR 21 TC 12 Z9 12 U1 1 U2 8 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 1 PY 1999 VL 37 IS 17 BP 2303 EP 2313 DI 10.1002/(SICI)1099-0488(19990901)37:17<2303::AID-POLB2>3.3.CO;2-F PG 11 WC Polymer Science SC Polymer Science GA 228NW UT WOS:000082143400002 ER PT J AU Neudecker, BJ Zuhr, RA Bates, JB AF Neudecker, BJ Zuhr, RA Bates, JB TI Lithium silicon tin oxynitride (LiySiTON): high-performance anode in thin-film lithium-ion batteries for microelectronics SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 9th International Meeting on Lithium Batteries CY JUL 12-17, 1998 CL EDINBURGH, SCOTLAND SP Electrochem Soc, Battery Div, Electrochem Soc Japan, Comm Battery Technol, Int Soc Electrochem, Danion, Eveready Battery Co Inc, LIBES, Lothian & Edinburgh Enterprise Ltd, OSTEC, SAFT, Solartron, Univ St Andrews DE silicon tin oxynitride (SiTON); lithium-ion battery; solder reflow; microelectronics; heat treatment; hysteresis ID SYSTEM AB A lithium-ion thin-film battery, consisting of the amorphous silicon tin oxynitride anode ('SiTON'), the amorphous lithium phosphorus oxynitride electrolyte ('Lipon'), and a crystalline LiCoO2 cathode, can be heated at 250 degrees C in air for 1 h which exceeds by far the required solder reflow conditions for electronic circuit assembly. Moreover, the performance of such a battery was found to even improve after the heat treatment. The LiySiTON profile between 0 and 1.2 V vs. Li was determined in SiTON/Lipon/LiCoO2 lithium-ion thin-film cells equipped with a Li metal reference electrode. By comparison with a Sn3N4/Lipon/LiCoO2 three-electrode lithium-ion thin-film cell, a model for the electrochemical insertion/extraction process of LiySiTON was suggested. The SiTON/Lipon/LiCoO2 cells sustained 5 mA/cm(2) between 4.2 and 2.7 V while the anode supplied a reversible discharge capacity of about 340 mu A h/mg or even 450 CLA h/mg after heating at 250 degrees C in air for 1 h. A long-termcycling stability test of a SiTON/Lipon/LiCoO2 battery between 3.93 and 2.7 V demonstrated that the LiySiTON capacity faded only by 0.001% per cycle when charging was stopped as soon as the LiySiTON potential reached 0 V vs. Li. When this cathode-heavy cell was charged to 4.1 V (LiySiTON at 0 V vs. Li), a significantly higher reversible discharge capacity was obtained over similar to 5000 cycles. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Neudecker, BJ (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 11 TC 99 Z9 110 U1 6 U2 70 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD SEP PY 1999 VL 81 BP 27 EP 32 DI 10.1016/S0378-7753(98)00202-X PG 6 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 262WE UT WOS:000084090300006 ER PT J AU Thackeray, MM Johnson, CS Kahaian, AJ Kepler, KD Vaughey, JT Shao-Horn, Y Hackney, SA AF Thackeray, MM Johnson, CS Kahaian, AJ Kepler, KD Vaughey, JT Shao-Horn, Y Hackney, SA TI Stabilization of insertion electrodes for lithium batteries SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 9th International Meeting on Lithium Batteries CY JUL 12-17, 1998 CL EDINBURGH, SCOTLAND SP Electrochem Soc, Battery Div, Electrochem Soc Japan, Comm Battery Technol, Int Soc Electrochem, Danion, Eveready Battery Co Inc, LIBES, Lothian & Edinburgh Enterprise Ltd, OSTEC, SAFT, Solartron, Univ St Andrews DE lithium battery; electrodes; structure; stability ID LI-ION CELLS; ORTHORHOMBIC LIMNO2; TEMPERATURE PERFORMANCE; MANGANESE-DIOXIDE; LAYERED LIMNO2; CATHODE; SPINELS; LIMN2O4; OXIDES AB This paper discusses the techniques that are being employed to stabilize LiMn2O4 spinel and composite LixMnO2 positive electrodes. The critical role that spinel domains play in stabilizing these electrodes for operation at both 4 V and 3 V is highlighted. The concept of using an intermetallic electrode MM' where M is an active alloying element and M' is an inactive element (or elements) is proposed as an alternative negative electrode (to carbon) for lithium-ion cells. An analogy to metal oxide insertion electrodes, such as MnO2, in which Mn is the electrochemically active ion and O is the inactive ion, is made. performance data are given for the copper-tin electrode system, which includes the intermetallic phases eta-Cu6Sn5 and Li2CuSn. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Div Chem Technol, Electrochem Technol Program, Argonne, IL 60439 USA. Michigan Technol Univ, Houghton, MI 49931 USA. RP Thackeray, MM (reprint author), Argonne Natl Lab, Div Chem Technol, Electrochem Technol Program, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Vaughey, John/0000-0002-2556-6129 NR 31 TC 19 Z9 22 U1 2 U2 16 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD SEP PY 1999 VL 81 BP 60 EP 66 DI 10.1016/S0378-7753(98)00203-1 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 262WE UT WOS:000084090300012 ER PT J AU Kinoshita, K Song, X Kim, J Inaba, M AF Kinoshita, K Song, X Kim, J Inaba, M TI Development of a carbon-based lithium microbattery SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 9th International Meeting on Lithium Batteries CY JUL 12-17, 1998 CL EDINBURGH, SCOTLAND SP Electrochem Soc, Battery Div, Electrochem Soc Japan, Comm Battery Technol, Int Soc Electrochem, Danion, Eveready Battery Co Inc, LIBES, Lothian & Edinburgh Enterprise Ltd, OSTEC, SAFT, Solartron, Univ St Andrews DE lithium microbattery; carbon electrode; carbon film; polypyrrole ID PHOTORESIST; FILMS; MEMS AB A conceptual design for a carbon-based rechargeable Li microbattery and the progress in fabricating the electrode microstructures are described in this paper. The microstructures are produced from photoresists that are typically used by the semiconductor industry. The photoresist is spin coated on a silicon wafer, "patterned' by photolithography and then heated in an inert environment to form carbon microstructures(< 50-micron dimension) which serve as the electrodes. Progress in fabricating the electrode microstructures, lithiation of the carbon negative electrode and electropolymerization of the polypyrrole positive electrode will be discussed. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Kyoto Univ, Dept Energy & Hydrocarbon, Grad Sch Engn, Kyoto 60601, Japan. RP Kinoshita, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 10 TC 26 Z9 26 U1 2 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD SEP PY 1999 VL 81 BP 170 EP 175 DI 10.1016/S0378-7753(99)00189-5 PG 6 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 262WE UT WOS:000084090300029 ER EF