FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Ravikumar, V Dravid, VP Wolf, D AF Ravikumar, V Dravid, VP Wolf, D TI Atomic structure and properties of the (310) symmetrical tilt grain boundary (STGB) in SrTiO3. Part I: Atomistic simulations SO INTERFACE SCIENCE LA English DT Article DE grain boundaries; atomistic simulations; atomic structure; SrTiO3; grain boundary energy ID TRANSMISSION ELECTRON-MICROSCOPY; SPACE-CHARGE DISTRIBUTION; COMPUTER-SIMULATION; INTERNAL INTERFACES; STRONTIUM-TITANATE; NICKEL-OXIDE; SOLUTE SEGREGATION; PLAUSIBLE CONCEPTS; SURFACE-STRUCTURE; TWIST BOUNDARIES AB The relaxed structure and energy of the (310) symmetrical tilt grain boundary (STGB) in SrTiO3 have been calculated using static lattice energy minimization methods. In principle, the (310) GB plane can either be a cation-rich, positively charged "SrTiO" plane or a negatively charged oxygen plane, and both scenarios have been considered in this report. The effect of point-defect reconstruction at the GB core region, manifested either as completely missing columns or as half-filled columns of ions as suggested by experiments, has been analyzed. The results indicate that while Schottky defects are very strongly preferred energetically at the GB core, there is not significant gain in energy by having half-filled columns, as opposed to fully-dense and fully-empty columns, at the GB core. The simulation results have been analyzed in the context of Pauling's rules of crystal chemistry and bicrystallography. The results form the basis for an objective comparison with experimental studies in Part II of the paper. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RI Dravid, Vinayak/B-6688-2009 NR 63 TC 14 Z9 14 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0927-7056 J9 INTERFACE SCI JI Interface Sci. PD AUG PY 2000 VL 8 IS 2-3 BP 157 EP 175 DI 10.1023/A:1008715125452 PG 19 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 360BC UT WOS:000089645700004 ER PT J AU Duscher, G Buban, JP Browning, ND Chisholm, MF Pennycook, SJ AF Duscher, G Buban, JP Browning, ND Chisholm, MF Pennycook, SJ TI The electronic structure of pristine and doped (100) tilt grain boundaries in SrTiO(3) SO INTERFACE SCIENCE LA English DT Article DE SrTiO(3); electronic structure; EELS; Z-contrast imaging ID ENERGY-LOSS SPECTROSCOPY; ATOMIC-STRUCTURE; STRONTIUM-TITANATE; DEFECT CHEMISTRY; OXIDES; INTERFACES; ACCEPTOR; SEGREGATION; SCALE AB To understand the electronic properties of doped grain boundaries, we reviewed the atomic scale techniques currently available to study the electronic structure at pristine SrTiO(3) grain boundaries. The knowledge gained from the pristine boundaries is used to interpret experimental and theoretical results from a Mn doped Sigma 5 SrTiO(3) grain boundaries. Mn atoms are shown to preferentially substitute at specific Ti sites at the grain boundary core. Furthermore, the formal oxidation state of the Mn atoms at the grain boundary core was found to be reduced compared to the Mn atoms substituting for Ti in the bulk. This change of valence did not, however, significantly affect the atomic structure of the grain boundary, as determined by Z-contrast imaging and electron energy-loss spectroscopy, which revealed similar fine-structure features at both the doped and pristine grain boundary. We conclude, therefore, that composition and atomic structure have different effects on the local electronic structure and should be treated separately in any segregation and electrical conductivity models for grain boundaries. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN USA. Univ Illinois, Dept Phys, Chicago, IL 60680 USA. RI Duscher, Gerd/G-1730-2014; Albe, Karsten/F-1139-2011 OI Duscher, Gerd/0000-0002-2039-548X; NR 42 TC 16 Z9 16 U1 0 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0927-7056 J9 INTERFACE SCI JI Interface Sci. PD AUG PY 2000 VL 8 IS 2-3 BP 199 EP 208 DI 10.1023/A:1008750706797 PG 10 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 360BC UT WOS:000089645700007 ER PT J AU Stemmer, S Streiffer, SK Browning, ND Basceri, C Kingon, AI AF Stemmer, S Streiffer, SK Browning, ND Basceri, C Kingon, AI TI Grain boundaries in barium strontium titanate thin films: Structure, chemistry and influence on electronic properties SO INTERFACE SCIENCE LA English DT Article DE barium strontium titanate; electron energy-loss spectroscopy (EELS); metal oxide thin films; dielectric properties ID CHEMICAL-VAPOR-DEPOSITION; X-RAY-ABSORPTION; ENERGY-LOSS SPECTROSCOPY; RANDOM-ACCESS MEMORIES; DIELECTRIC-PROPERTIES; (BA; BA0.7SR0.3TIO3; ACCOMMODATION; SENSITIVITY; CAPACITORS AB In this paper, we investigate the role of grain boundaries in polycrystalline (BaxSr1-x)Ti1+yO3+z films, grown by metal organic vapor deposition, in the accommodation of nonstoichiometry, as well as their role in the strong composition dependence of the electric and dielectric behavior observed in these films. High-spatial resolution electron energy-loss spectroscopy is used for the analysis of composition and structural changes at grain boundaries, as a function of film composition. The existence of amorphous, titanium rich, TiO2-like phases at the grain boundaries of films with large amounts of excess Ti (y greater than or equal to 0.08) may explain the non-monotonic resistance degradation behavior of the films as a function of Ti content. However, we show that a grain boundary phase model fails to explain the strong composition dependence of the dielectric behavior. Electron energy-loss spectra indicate a distortion of the Ti-O octahedra in the grain interiors in samples with increasing Ti excess. The decrease of the dielectric constant with increasing amounts of excess Ti is therefore more likely due to Ti accommodation in the grain interiors. C1 Rice Univ, Dept Mech Engn & Mat Sci, Houston, TX 77005 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. RI Streiffer, Stephen/A-1756-2009; Stemmer, Susanne/H-6555-2011; OI Stemmer, Susanne/0000-0002-3142-4696; Browning, Nigel/0000-0003-0491-251X NR 35 TC 20 Z9 22 U1 0 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0927-7056 J9 INTERFACE SCI JI Interface Sci. PD AUG PY 2000 VL 8 IS 2-3 BP 209 EP 221 DI 10.1023/A:1008794520909 PG 13 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 360BC UT WOS:000089645700008 ER PT J AU Carmody, M Merkle, KL Huang, Y Marks, LD Moeckly, BH AF Carmody, M Merkle, KL Huang, Y Marks, LD Moeckly, BH TI The relation between barrier structure and current uniformity in YBCO Josephson junctions SO INTERFACE SCIENCE LA English DT Article DE Josephson junctions; HREM; current distribution; grain boundaries ID GRAIN-BOUNDARY JUNCTIONS; CRITICAL-CURRENT DENSITY; CURRENT-PHASE RELATION; YBA2CU3O7 THIN-FILMS; T-C BICRYSTAL; ELECTRICAL-PROPERTIES; MAGNETIC-FIELD; MICROSTRUCTURE; SUPERCONDUCTORS; MICROSCOPY AB Electromagnetic transport measurements were combined with high-resolution electron microscopy observations to study the relation between structure and local critical currents in YBa2Cu3O7-x (YBCO) Josephson junctions. The spatial variation of the critical current J(x) along the length of the boundary for interface engineered Josephson junctions and bicrystal grain boundary Josephson junctions was determined using a phase retrieval algorithm. The current distribution solutions were found to be highly uniform along the length of interface engineered junctions in contrast to solutions for grain boundary junctions. The latter showed significant spatial oscillations in the critical current as well as areas along the boundary that carried no current. Microstructural evaluation of interface engineered junctions fabricated using identical processing parameters to the junctions used for transport measurements suggest that the uniform current distribution is controlled by a highly uniform barrier layer formed between the superconducting electrodes. Microstructural evaluation of grain boundary junctions similar to the junctions used for transport measurements show considerable variations of the grain boundary structure within a single junction. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Conductus Inc, Sunnyvale, CA 94086 USA. RI Marks, Laurence/B-7527-2009 NR 48 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 0927-7056 J9 INTERFACE SCI JI Interface Sci. PD AUG PY 2000 VL 8 IS 2-3 BP 231 EP 242 DI 10.1023/A:1008746621818 PG 12 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 360BC UT WOS:000089645700010 ER PT J AU Rosales, I Schneibel, JH AF Rosales, I Schneibel, JH TI Stoichiometry and mechanical properties of Mo3Si SO INTERMETALLICS LA English DT Article DE molybdenum silicides; fracture toughness; yield stress ID MO5SI3; BORON; SILICIDES AB The A15 phase Mo3Si is an important constituent of a new class of silicides based on Mo-Si-B. In this research it will be shown that, contrary to published results, single-phase Mo3Si is slightly off-stoichiometric. In addition, it remains single phase in a small composition range. Its room temperature fracture toughness is on the order of 3 MPa m(1/2). The compressive strength at 1400 degrees C in argon decreases with decreasing strain rate and increasing Si concentration. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Schneibel, JH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 58 Z9 65 U1 0 U2 7 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 AUG PY 2000 VL 8 IS 8 BP 885 EP 889 DI 10.1016/S0966-9795(00)00058-3 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 348LV UT WOS:000088987000007 ER PT J AU Williams, JJ Ye, YY Kramer, MJ Ho, KM Hong, L Fu, CL Malik, SK AF Williams, JJ Ye, YY Kramer, MJ Ho, KM Hong, L Fu, CL Malik, SK TI Theoretical calculations and experimental measurements of the structure of Ti5Si3 with interstitial additions SO INTERMETALLICS LA English DT Article DE titanium silicides; crystal chemistry of intermetallics; electronic structure, calculation; diffraction (electron, neutron and X-ray) ID ELECTRONIC-STRUCTURE; METALS AB The equilibrium structural parameters, enthalpies of formation and partial densities of state for Ti5Si3 and Ti(5)Si(3)Z(0.5) (Z = B, C, N or O) were calculated based on first-principle techniques. Enthalpy of formation calculations suggest that of the known structures for transition metal (TM) silicide compounds containing TM5Si3 (D8(8), D8(1) and D8(m)) the D8(8) structure is the most stable form of Ti5Si3, and the stability of the structure increases as Z atoms are added. The theoretically determined structural trends as a function of interstitial element, Z, agreed well with experimentally determined values. Both indicate bonding between Ti and Z atoms based on contraction of Ti-Z separations. The calculated partial densities of state suggest that p(Si)-d(Ti) and d(Ti)-d(Ti) interactions an responsible for most of the bonding in pure Ti5Si3, which agrees with previous studies. As Z atoms are added, p(Z)-d(Ti) interactions become significant at the expense of weakening some of the d(Ti)-d(Ti) interactions. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Wuhan Univ, Ctr Anal & Testing, Wuhan 430072, Peoples R China. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Univ Missouri Res Reactor, Columbia, MO 65211 USA. RP Kramer, MJ (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 20 TC 35 Z9 35 U1 1 U2 10 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 AUG PY 2000 VL 8 IS 8 BP 937 EP 943 DI 10.1016/S0966-9795(00)00064-9 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 348LV UT WOS:000088987000012 ER PT J AU Freitag, LA Ollivier-Gooch, C AF Freitag, LA Ollivier-Gooch, C TI A cost/benefit analysis of simplicial mesh improvement techniques as measured by solution efficiency SO INTERNATIONAL JOURNAL OF COMPUTATIONAL GEOMETRY & APPLICATIONS LA English DT Article; Proceedings Paper CT 6th International Meshing Roundtable Meeting CY OCT 13-15, 1997 CL PARK CITY, UTAH DE mesh improvement; solution efficiency; mesh smoothing ID CONJUGATE-GRADIENT METHOD; LOCAL TRANSFORMATIONS; CONVERGENCE RATE; FINITE; TRIANGULATIONS; REFINEMENT AB The quality of unstructured meshes has long been known to affect both the efficiency and the accuracy of the numerical solution of application problems. Mesh quality can often be improved through the use of algorithms based on local reconnection schemes, node smoothing, and adaptive refinement or coarsening. These methods typically incur a significant cost, and in this paper, we provide an analysis of the tradeoffs associated with the cost of mesh improvement in terms of solution efficiency. We first consider simple finite element applications and show the effect of increasing the number of poor quality elements in the mesh and decreasing their quality on the solution time of a number of different solvers. These simple application problems are theoretically well-understood, and we show the relationship between the quality of the mesh and the eigenvalue spectrum of the resulting linear system. We then consider realistic finite element and finite volume application problems, and show that the cost of mesh improvement is significantly less than the cost of solving the problem on a poorer quality mesh. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ British Columbia, Dept Mech Engn, Vancouver, BC V6T 1Z4, Canada. RP Freitag, LA (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ollivier-Gooch, Carl/E-8934-2011 OI Ollivier-Gooch, Carl/0000-0001-6514-058X NR 33 TC 21 Z9 25 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 0218-1959 J9 INT J COMPUT GEOM AP JI Int. J. Comput. Geom. Appl. PD AUG PY 2000 VL 10 IS 4 BP 361 EP 382 DI 10.1142/S0218195900000218 PG 22 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA 349XK UT WOS:000089070700002 ER PT J AU Mitchell, SA AF Mitchell, SA TI High fidelity interval assignment SO INTERNATIONAL JOURNAL OF COMPUTATIONAL GEOMETRY & APPLICATIONS LA English DT Article; Proceedings Paper CT 6th International Meshing Roundtable Meeting CY OCT 13-15, 1997 CL PARK CITY, UTAH DE interval assignment; mixed-integer linear programming; conformal meshing; mesh control AB Quadrilateral meshing algorithms impose certain constraints on the number of intervals or mesh edges of the curves bounding a surface. When constructing a conformal mesh of a collection of adjoining surfaces, the constraints for all of the surfaces must be simultaneously satisfied. These constraints can be formulated as an integer linear program. Not all solutions to this problem are equally desirable, however. The user typically indicates a goal (soft-set) or required (hard-set) number of intervals for each curve. The hard-sets constrain the problem further, while the soft-sets influence the objective function. This paper describes an algorithm for solving this interval assignment problem. In a good solution, for each curve the positive or negative difference between its goal and assigned number of intervals is small relative to its number of goal intervals. The algorithm solves a series of linear programs, and comes close to minimizing the maximum lexicographic vector of these weighted differences. Then the algorithm solves a nearby mixed-integer linear program to satisfy certain "sum-even" constraints. The algorithm reliably produces numbers of intervals that are very close to the user's desires and is easily extendible to new constraints. Earlier versions of the algorithm(1) were slower than alternative algorithms, but this is no longer a significant issue; in practice, the running time is a minor fraction of the time to mesh, even in models composed of thousands of curves. C1 Sandia Natl Labs, Parallel Comp Sci Dept, Albuquerque, NM 87185 USA. RP Mitchell, SA (reprint author), Sandia Natl Labs, Parallel Comp Sci Dept, POB 5800,MS 0441, Albuquerque, NM 87185 USA. NR 9 TC 4 Z9 4 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-1959 J9 INT J COMPUT GEOM AP JI Int. J. Comput. Geom. Appl. PD AUG PY 2000 VL 10 IS 4 BP 399 EP 415 DI 10.1142/S0218195900000231 PG 17 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA 349XK UT WOS:000089070700004 ER PT J AU Warren, TL Tabbara, MR AF Warren, TL Tabbara, MR TI Simulations of the penetration of 6041-T6511 aluminum targets by spherical-nosed VAR 4340 steel projectiles SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE penetration; spherical cavity expansion; finite elements ID RODS; PERFORATION AB In certain penetration events it is proposed that the primary mode of deformation of the target can be approximated by known analytical expressions. In the context of an analysis code, this approximation eliminates the need for discretizing the target as well as the need for a contact algorithm. Thus, this method substantially reduces the computer time and memory requirements. In this paper a forcing function which is derived from a spherical-cavity expansion (SCE) analysis has been implemented in a transient dynamic finite element code. This implementation is capable of computing the structural and component responses of a projectile due to a three dimensional penetration event. Simulations are presented for 7.11-mm-diameter, 74.7-mm-long, spherical-nose, vacuum-arc-remelted (VAR) 4340 steel projectiles that penetrate 6061-T6511 aluminum targets. Final projectile configurations obtained from the simulations are compared with post-test radiographs obtained from the corresponding experiments. It is shown that the simulations accurately predict the permanent projectile deformation for three dimensional loadings due to incident pitch and yaw over a wide range of striking velocities. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Warren, TL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 28 TC 24 Z9 32 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD AUG PY 2000 VL 37 IS 32 BP 4419 EP 4435 DI 10.1016/S0020-7683(99)00148-1 PG 17 WC Mechanics SC Mechanics GA 313JK UT WOS:000086996400006 ER PT J AU Das, S AF Das, S TI The life-cycle impacts of aluminum body-in-white automotive material SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB In this study, life-cycle comparisons of energy usage and CO2 emission of aluminum vs, conventional steel and the ultralight steel auto body were made for body-in-white applications at both the vehicle and fleet levels. The analysis considered three major stages of the life cycle: manufacturing, use, and recycling. The analysis also studied how life-cycle energy and emission benefits are affected by changes in input parameter values, such ns manufacturing energy, vehicle-sales growth rate, secondary weight savings, fuel efficiency, and a lower aluminum replacement rate. C1 Oak Ridge Natl Lab, Div Energy, Oak Ridge, TN 37831 USA. RP Das, S (reprint author), Oak Ridge Natl Lab, Div Energy, POB 2008,Bldg 4500N,1Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 13 TC 29 Z9 29 U1 2 U2 9 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD AUG PY 2000 VL 52 IS 8 BP 41 EP 44 DI 10.1007/s11837-000-0173-2 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 342QK UT WOS:000088656500007 ER PT J AU Liu, YG Daum, PH AF Liu, YG Daum, PH TI The effect of refractive index on size distributions and light scattering coefficients derived from optical particle counters SO JOURNAL OF AEROSOL SCIENCE LA English DT Article ID RESPONSE CHARACTERISTICS; ATMOSPHERIC AEROSOLS; NEPHELOMETER AB The effect of refractive index on particle size distributions measured by optical particle counters is examined. Similar to previous investigations, it is found that optical counters undersize ambient particles because the refractive index of these particles is generally lower than that of the latex particles commonly used for the calibration of optical counters. The maximum undersizing is found to occur when particle sizes are comparable to the wavelength of light used in the measurement. A new approach for modeling the effect of refractive index on the sizing of optical counters is presented. Previously derived optical response functions are compared and a generalized formulation is proposed which includes the existing response functions as special cases. Algorithms are presented for correcting size distributions measured by optical counters for the difference between the refractive index of ambient and calibration particles. Data collected by a Passive Cavity Aerosol Spectrometer (PCASP) and by an integrating nephelometer are compared. Light scattering coefficients calculated from the optical probe data uncorrected for the effect of refractive index differ from those measured by the integrating nephelometer by a factor of 2. An iterative procedure that adjusts the PCASP-measured size distribution for the effect of refractive index is used to derive the best agreement between calculated and observed light scattering coefficients. The refractive indices of aerosols at wavelength of 0.45 mu m that best fit the data vary between 1.3 and 1.5, with an average of 1.41. The relative importance of the underestimation of light scattering coefficients calculated from the PCASP-measured size distributions due to the refractive index and the size truncation effect are evaluated. The Former is found to be more important than the latter. Implications of this study for addressing aerosol shortwave radiative forcing and potential uncertainties relevant to this study are discussed. Published by Elsevier Science Ltd. C1 Brookhaven Natl Lab, Environm Chem Div, Upton, NY 11973 USA. RP Liu, YG (reprint author), Brookhaven Natl Lab, Environm Chem Div, Bldg 815E,POB 5000, Upton, NY 11973 USA. RI Liu, Yangang/H-6154-2011 NR 23 TC 73 Z9 75 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0021-8502 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD AUG PY 2000 VL 31 IS 8 BP 945 EP 957 DI 10.1016/S0021-8502(99)00573-X PG 13 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 322KR UT WOS:000087509200006 ER PT J AU Butler, BD Haeffner, DR Lee, PL Welberry, TR AF Butler, BD Haeffner, DR Lee, PL Welberry, TR TI High-energy X-ray diffuse scattering using Weissenberg flat-cone geometry SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID TLSBOGEO4 AB A technique for the measurement of diffuse X-ray scattering on individual reciprocal-space planes using high-energy X-ray photons is described. The method is demonstrated using a disordered crystal of the compound TlSbOGeO4 and compared to data collected with a sealed-tube Cu anode source. Measurements were made on a synchrotron undulator beamline at an energy of 45 keV using Weissenberg flat-cone geometry and a storage phosphor (image) plate to detect the scattered X-rays. Advantages of the method include: extension of the accessible diffraction space to both higher and lower wavevectors, the ability to use crystals of irregular shape without the need for complicated absorption corrections, less need to prepare sample surfaces carefully, and the ability to filter fluorescence simply. C1 Argonne Natl Lab, Adv Photon Source, SRI CAT, Argonne, IL USA. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Haeffner, DR (reprint author), Argonne Natl Lab, Adv Photon Source, SRI CAT, Argonne, IL USA. EM haeffner@aps.anl.gov RI Welberry, Thomas/H-7847-2014 OI Welberry, Thomas/0000-0002-6906-9191 NR 5 TC 9 Z9 9 U1 1 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0021-8898 EI 1600-5767 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 2000 VL 33 BP 1046 EP 1050 DI 10.1107/S0021889800005318 PN 4 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 337LR UT WOS:000088363000007 ER PT J AU Zhong, Z AF Zhong, Z TI Using a prism to reject or select harmonic reflections in an X-ray monochromator SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID ANOMALOUS SCATTERING FACTORS; CRYSTAL MONOCHROMATORS; SYNCHROTRON RADIATION; REFRACTION AB The angle by which an X-ray deviates from its original direction when it passes through a refractive prism is proportional to the square of the X-ray wavelength. This effect was used to discriminate between different harmonic orders of a two-crystal non-dispersive monochromator. Two cases are discussed. In the first case, a refractive prism allows tuning of the silicon 333 reflection to the peak of its double-crystal rocking curve while the higher-order harmonics are suppressed, with much of the harmonic rejection being controllable by the angle of the prism. In the second case, it is demonstrated that slightly tuning the second crystal of the monochromator allows the selection of a specific harmonic order from among reflections 333, 444 and 555. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Zhong, Z (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. NR 17 TC 13 Z9 13 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 2000 VL 33 BP 1082 EP 1087 DI 10.1107/S0021889800005343 PN 4 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 337LR UT WOS:000088363000012 ER PT J AU Lovelac, J Snell, EH Pokross, M Arvai, AS Nielsen, C Xuong, NH Bellamy, HD Borgstahl, GEO AF Lovelac, J Snell, EH Pokross, M Arvai, AS Nielsen, C Xuong, NH Bellamy, HD Borgstahl, GEO TI BEAM-ish: a graphical user interface for the physical characterization of macro-molecular crystals SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Software Review DE graphical user interface; macromolecules; protein crystals; mosaicity; crystal quality; fine phi slicing; X-ray diffraction ID PROTEIN CRYSTAL C1 Univ Toledo, Dept Chem, Toledo, OH 43606 USA. NASA, George C Marshall Space Flight Ctr, Lab Struct Biol, Huntsville, AL 35812 USA. Area Detector Syst Corp, Poway, CA 92064 USA. Univ Calif San Diego, Dept Chem, San Diego, CA 92093 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Borgstahl, GEO (reprint author), Univ Toledo, Dept Chem, 2801 W Bancroft St, Toledo, OH 43606 USA. EM gborgst@uoft02.utoledo.edu FU NASA [NAG8-1380] FX This work was funded by NASA grant NAG8-1380. NR 5 TC 12 Z9 12 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 2000 VL 33 BP 1187 EP 1188 DI 10.1107/S0021889800005732 PN 4 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 337LR UT WOS:000088363000030 ER PT J AU Doran, JC Zhong, S AF Doran, JC Zhong, S TI Thermally driven gap winds into the Mexico City basin SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MODEL AB A southeasterly flow in the form of a low-level jet that enters the Mexico City basin through a mountain gap in the southeast corner of the basin developed consistently in the afternoons or early evenings during a four-week 1997 winter field campaign. Peak wind speeds often exceeded 10 m s(-1). Although these winds have not been studied previously, the observations suggest that they are a regular feature of the basin wind system, at least during the winter months. The jets were found more frequently during the early Dart of the experiment, when conditions in the basin were generally warmer, drier, and less cloudy, than in the later part when conditions were cooler, more humid, and cloudier. The winds usually were stronger during the early period, also. Temperature measurements from radiosondes launched inside and outside the basin showed a dependence of the gap wind strength on the temperature differences between the two regions. A three-dimensional numerical model was used to simulate the characteristics of the gap flows to provide information on the mechanisms responsible for their development. The maximum speed of the jet usually is reached several hours after the occurrence of the maximum temperature gradient between the basin and the region to the south. An analysis of the momentum balance shows that the gap wind is initiated by a north-south pressure gradient across the gap in the lower boundary layer arising from temperature differences between the warmer basin and the cooler exterior air. Penetration of the gap wind into the basin is caused primarily by horizontal advection. The gap wind plays an important role in the formation of a convergence zone, which can have an important effect on surface air pollutant distributions in the basin. C1 Pacific NW Natl Lab, Richland, WA USA. RP Doran, JC (reprint author), POB 999,MSIN K9-30, Richland, WA 99352 USA. NR 20 TC 32 Z9 33 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 2000 VL 39 IS 8 BP 1330 EP 1340 DI 10.1175/1520-0450(2000)039<1330:TDGWIT>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348JE UT WOS:000088981100007 ER PT J AU Raitses, Y Dorf, LA Litvak, AA Fisch, NJ AF Raitses, Y Dorf, LA Litvak, AA Fisch, NJ TI Plume reduction in segmented electrode Hall thruster SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PLASMA AB A segmented electrode, which is placed at the thruster exit, is shown to affect thruster operation in several ways, whether the electrode produces low emission current or no emission current, although there appear to be advantages to the more emissive segmented electrode. Measured by plume divergence, the performance of Hall thruster operation, even with only one power supply, can approach or surpass that of nonsegmented operation over a range of parameter regimes. In particular, the low gas flow rate can exhibit low plume divergence. This allows flexibility in operation of segmented electrode thrusters in variable thrust regimes. (C) 2000 American Institute of Physics. [S0021-8979(00)02615-3]. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Raitses, Y (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 17 TC 51 Z9 51 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 2000 VL 88 IS 3 BP 1263 EP 1270 AR PII [S0021-8979(00)02615-3] DI 10.1063/1.373813 PG 8 WC Physics, Applied SC Physics GA 334CA UT WOS:000088166500010 ER PT J AU Leung, OS Munkholm, A Brennan, S Nix, WD AF Leung, OS Munkholm, A Brennan, S Nix, WD TI A search for strain gradients in gold thin films on substrates using x-ray diffraction SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MECHANICAL-PROPERTIES; STRESS; PLASTICITY; DEPENDENCE AB The high strengths of gold thin films on silicon substrates have been studied with particular reference to the possible effect of strain gradients. Wafer curvature/thermal cycling measurements have been used to study the strengths of unpassivated, oxide-free gold films ranging in thickness from 0.1 to 2.5 mu m. Films thinner than about 1 mu m in thickness appear to be weakened by diffusional relaxation effects near the free surface and are not good candidates for the study of strain gradient plasticity. Our search for plastically induced strain gradients was thus limited to thicker films with correspondingly larger grain sizes. Three related x-ray diffraction techniques have been used to investigate the elastic strains in these films. The standard d(hkl) vs sin(2) Psi technique has been used to find the average strain through the thickness of the films. The results are consistent with wafer curvature measurements. We have also measured a number of d(hkl)'s as a function of penetration depth to construct depth-dependent d(hkl) vs sin(2) Psi plots. These data show that the residual elastic strain is essentially independent of depth in the film. Finally, a new technique for sample rotation has been used to measure the d(hkl)'s for a fixed set of grains in the film as a function of penetration depth. Again, no detectable gradient in strain has been observed. These results show that the high strengths of unpassivated gold films relative to the strength of bulk gold cannot be rationalized on the basis of strain gradients through the film thickness. However, a sharp gradient in strain close to the film substrate interface cannot be ruled out. (C) 2000 American Institute of Physics. [S0021-8979(00)03815-9]. C1 Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Leung, OS (reprint author), Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. NR 26 TC 31 Z9 31 U1 2 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 2000 VL 88 IS 3 BP 1389 EP 1396 AR PII [S0021-8979(00)03815-9] DI 10.1063/1.373828 PG 8 WC Physics, Applied SC Physics GA 334CA UT WOS:000088166500026 ER PT J AU Hakovirta, M He, XM Nastasi, M AF Hakovirta, M He, XM Nastasi, M TI Optical properties of fluorinated diamond-like carbon films produced by pulsed glow discharge plasma immersion ion processing SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Pulsed glow discharge plasma from a 1 Pa gas mixture of acetylene (C2H2) and hexafluoroethane (C2F6) was used to produce fluorinated diamond-like carbon (F-DLC) films on glass and polymethyl-methacrylate (PMMA) substrate. The composition of the F-DLC coatings was measured by using Rutherford backscattering spectroscopy and elastic recoil detection analysis techniques. The transmittance, absorption coefficient, and optical band gap of 100 nm thick F-DLC coatings was measured by using an ultraviolet/visible spectrometer. The friction and wear properties were measured with a conventional pin-on-disk device. In addition, contact angle measurements were taken in order to determine the nonwetting properties of the coatings. The results showed an increase in nonwetting properties, transmittance, and optical band gap with increasing fluorine content in the coatings. The increased fluorine contents suppressed the incorporation of hydrogen and increased the optical band gap energy, which is quite different from the general DLC films whose optical properties are highly improved with increasing amount of hydrogen incorporated in the films. Furthermore, the F-DLC coatings on PMMA and glass substrates proved to have low friction and wear and similar nonwetting properties such as Teflon(R). [S0021-8979(00)02115-0]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. RP Hakovirta, M (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 32 Z9 34 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 2000 VL 88 IS 3 BP 1456 EP 1459 DI 10.1063/1.373838 PG 4 WC Physics, Applied SC Physics GA 334CA UT WOS:000088166500036 ER PT J AU Yoo, JH Jeong, SH Greif, R Russo, RE AF Yoo, JH Jeong, SH Greif, R Russo, RE TI Explosive change in crater properties during high power nanosecond laser ablation of silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; HEAT-TRANSFER; GAS-DYNAMICS; SURFACE; SOLIDIFICATION; INTENSITY; ALUMINUM; SAMPLES; METALS; FILMS AB Mass removed from single crystal silicon samples by high irradiance (1x10(9) to 1x10(11) W/cm(2)) single pulse laser ablation was studied by measuring the resulting crater morphology with a white light interferometric microscope. The craters show a strong nonlinear change in both the volume and depth when the laser irradiance is less than or greater than approximate to 2.2x10(10) W/cm(2). Time-resolved shadowgraph images of the ablated silicon plume were obtained over this irradiance range. The images show that the increase in crater volume and depth at the threshold of 2.2x10(10) W/cm(2) is accompanied by large size droplets leaving the silicon surface, with a time delay similar to 300 ns. A numerical model was used to estimate the thickness of the layer heated to approximately the critical temperature. The model includes transformation of liquid metal into liquid dielectric near the critical state (i.e., induced transparency). In this case, the estimated thickness of the superheated layer at a delay time of 200-300 ns shows a close agreement with measured crater depths. Induced transparency is demonstrated to play an important role in the formation of a deep superheated liquid layer, with subsequent explosive boiling responsible for large-particulate ejection. (C) 2000 American Institute of Physics. [S0021-8979(00)04015-9]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Kwangju Inst Sci & Technol, Kwangju 500712, South Korea. RP Russo, RE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 41 TC 197 Z9 201 U1 4 U2 39 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 2000 VL 88 IS 3 BP 1638 EP 1649 DI 10.1063/1.373865 PG 12 WC Physics, Applied SC Physics GA 334CA UT WOS:000088166500065 ER PT J AU Chechetkin, VR Turygin, AY Proudnikov, DY Prokopenko, DV Kirillov, EV Mirzabekov, AD AF Chechetkin, VR Turygin, AY Proudnikov, DY Prokopenko, DV Kirillov, EV Mirzabekov, AD TI Sequencing by hybridization with the generic 6-mer oligonucleotide microarray: An advanced scheme for data processing SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID QUARTET STRUCTURES; DNA; MICROCHIPS; ARRAYS; EFFICIENCY; DUPLEXES; MATRIX AB DNA sequencing by hybridization was carried out with a microarray pf all 4(6) = 4,096 hexadeoxyribonucleotides (the generic microchip). The oligonucleotides immobilized in 100 x 100 x 20-mu m polyacrylamide gel pads of the generic microchip were hybridized with fluorescently labeled ssDNA, providing perfect and mismatched duplexes. Melting curves were measured in parallel For all microchip duplexes with a fluorescence microscope equipped with CCD camera. This allowed us to discriminate the perfect duplexes formed by the oligonucleotides, which are complementary to the target DNA. The DNA sequence was reconstructed by overlapping the complementary oligonucleotides probes. We developed a data processing scheme to heighten the discrimination of perfect duplexes from mismatched ones. The procedure was united with a reconstruction of the DNA sequence. The scheme includes the proper definition of a discriminant signal, preprocessing, and the variational principle for the sequence indicator function. The effectiveness of the procedure was confirmed by sequencing, proofreading, and nucleotide polymer phism (mutation) analysis of 13 DNA fragments from 31 to 70 nucleotides long. C1 Russian Acad Sci, Engelhardt Inst Mol Biol, Moscow 117984, Russia. Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. RP Chechetkin, VR (reprint author), Russian Acad Sci, Engelhardt Inst Mol Biol, 32 Vavilov Str, Moscow 117984, Russia. NR 38 TC 24 Z9 24 U1 1 U2 1 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 USA SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD AUG PY 2000 VL 18 IS 1 BP 83 EP 101 PG 19 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 358VE UT WOS:000089577200008 PM 11021654 ER PT J AU Shchelkanov, MY Soinov, LA Petrenko, MS Starikov, NS Zalunin, VV Slavsky, AA Denisov, MV Kireev, VB Surovoy, AY AF Shchelkanov, MY Soinov, LA Petrenko, MS Starikov, NS Zalunin, VV Slavsky, AA Denisov, MV Kireev, VB Surovoy, AY TI Basic properties of populations generated in the frame of one-parameter discrete model of genetic diversity SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID GP120 V3 REGION; VARIABILITY ANALYSIS; HIV-1 AB Previously, when discussing the properties of one parameter discrete model of genetic diversity (M.Yu. Shchelkanov et al, J. Biomol. Struct. Dyn. 15, 887-894 (1998)), we took into account Hamming distance: distribution only between precursor and arbitrary descendant. sequences. However, really there are sets of sequence populations produced during amplification process. In the presented work we have investigated Hamming distance distributions between sequences from different descendant sets produced in the frame of one parameter discrete model. Two basic descendant generation operators (so called amplifiers) are introduced: 1) the last generation amplifier,(L) over cap, which produces descendants with precursor elimination; 2) all generations amplifer, (G) over cap, which produces descendants without precursor elimination. Generalization of one-parameter discrete model for the case when precursor sequences do not coincide are carried out. Using this generalization we investigate the distribution of Hamming distances between L - and (G) over cap -generated sequences. Basic properties of (L) over cap and (G) over cap operators, (L) over cap/(G) over cap -choice alternative problem have been discussed. Obtained results have common theoretical significance, but they are more suitable for high level genetic diversity process (for example, HIV diversity). C1 RAMS, DI Ivanovsky Inst Virol, Moscow 123098, Russia. Fac Physicochem Biol, Moscow Inst Phys & Technol, Dept Mol Biophys, Dolgoprudnyi 141700, Moscow Region, Russia. MM Shemyakin & Yu A Ovchinnikov Inst Biorgan Chem, Lab Peptide Chem, Moscow 117871, Russia. Univ Calif Los Alamos Natl Lab, Theoret Biol & Biophys Grp, Los Alamos, NM USA. RP Shchelkanov, MY (reprint author), RAMS, DI Ivanovsky Inst Virol, Gamaley Str 16, Moscow 123098, Russia. RI Kireev, Vjacheslav/D-8447-2014; Shchelkanov, Mikhail/L-6164-2016 OI Shchelkanov, Mikhail/0000-0001-8610-7623 NR 17 TC 0 Z9 0 U1 0 U2 1 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 USA SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD AUG PY 2000 VL 18 IS 1 BP 103 EP 112 PG 10 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 358VE UT WOS:000089577200009 PM 11021655 ER PT J AU Lee, CJ Mizel, A Banin, U Cohen, ML Alivisatos, AP AF Lee, CJ Mizel, A Banin, U Cohen, ML Alivisatos, AP TI Observation of pressure-induced direct-to-indirect band gap transition in InP nanocrystals SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CDSE QUANTUM DOTS; GAMMA-X CROSSOVER; EXCITED ELECTRONIC STATES; ENERGY-LEVELS; GAAS; PHOTOLUMINESCENCE; SPECTROSCOPY; DEPENDENCE; CONFINEMENT; ABSORPTION AB We investigate the quantum size effects in the pressure-induced direct-to-indirect band gap transition in InP nanocrystals. Hydrostatic pressures of up to 13 GPa are applied to two different sizes of InP nanocrystal samples in a diamond anvil cell. The band gap pressure dependence and the nature of the emitting states are studied by photoluminescence (PL) and fluorescence line narrowing (FLN) techniques at 10 K. Pressure-dependent FLN spectra show that the nature of the emitting states at pressures up to 9 GPa is similar to that at ambient pressure, suggesting that no direct-to-indirect transition happens below 9 GPa. For both sizes, the PL peak energy exhibits a strong blueshift with rising pressure until approximately 9 to 10 GPa. Above this pressure, the PL peak position slightly shifts red. Beyond 12 GPa, the band gap emission intensity becomes extremely weak and trap emission dominates the PL spectra. As the pressure is released, both the luminescence intensity and the peak position recover in a fully reversible manner. The change in the sign of the band gap energy pressure dependence and the disappearance of the band edge luminescence indicate the pressure-induced direct-to-indirect band gap transition. Contrary to theoretical calculations, no substantial reduction of the transition pressure is observed in the nanocrystal cases compared to the bulk transition pressure. (C) 2000 American Institute of Physics. [S0021-9606(00)70113-9]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. RP Lee, CJ (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 42 TC 15 Z9 15 U1 3 U2 12 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 2000 VL 113 IS 5 BP 2016 EP 2020 AR PII [S0021-9606(00)70113-9] DI 10.1063/1.482008 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 335XB UT WOS:000088269400046 ER PT J AU Hooper, JB McCoy, JD Curro, JG van Swol, F AF Hooper, JB McCoy, JD Curro, JG van Swol, F TI Density functional theory of simple polymers in a slit pore. III. Surface tension SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NONUNIFORM POLYATOMIC SYSTEMS; INTEGRAL-EQUATION THEORY; POLYETHYLENE; FLUIDS AB In a previous study of tangent hard-site chains near a surface, the inhomogeneous density profiles were found through density functional theory. In the current study, the surface tensions of these systems are found from the results of the previous study through a thermodynamic integration. The calculated surface tensions are then compared to those found directly through computer simulation. Both the surface tension and surface excess for polymeric systems are shown to differ qualitatively from those of atomic systems, although certain similarities are seen at high densities. (C) 2000 American Institute of Physics. [S0021-9606(00)50629-1]. C1 New Mexico Inst Min & Technol, Dept Mat & Met Engn, Socorro, NM 87801 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87106 USA. RP McCoy, JD (reprint author), New Mexico Inst Min & Technol, Dept Mat & Met Engn, Socorro, NM 87801 USA. RI McCoy, John/B-3846-2010 OI McCoy, John/0000-0001-5404-1404 NR 17 TC 31 Z9 32 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 2000 VL 113 IS 5 BP 2021 EP 2024 AR PII [S0021-9606(00)50629-1] DI 10.1063/1.482009 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 335XB UT WOS:000088269400047 ER PT J AU Hodge, EM AF Hodge, EM TI On-line monitoring of wastewater using ion chromatography SO JOURNAL OF CHROMATOGRAPHIC SCIENCE LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hodge, EM (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 1 TC 3 Z9 3 U1 1 U2 3 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0021-9665 J9 J CHROMATOGR SCI JI J. Chromatogr. Sci. PD AUG PY 2000 VL 38 IS 8 BP 353 EP 356 PG 4 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 343PW UT WOS:000088711600005 PM 10955510 ER PT J AU Golovlev, VV Gresalfi, MJ Miller, JC Romer, G Messier, P AF Golovlev, Valerie V. Gresalfi, Michael J. Miller, John C. Romer, Grant Messier, Paul TI Laser characterization and cleaning of nineteenth century daguerreotypes SO JOURNAL OF CULTURAL HERITAGE LA English DT Article DE daguerreotypes; laser ablation; mass spectrometry; SERS; laser cleaning AB Daguerreotypes were the first form of photographs and were popular between 1840 and 1860, after which they were superseded by more modern techniques. The daguerreotype image is composed of silver: mercury microcrystals of varying size and density on a silver-coated copper substrate. Nineteenth century daguerreotypes, over the intervening 140 years, have suffered degradation and oxidation, which has greatly reduced their historic and artistic value. Laser ablation techniques have been previously explored for use in the characterization, dating, and restoration of historic paintings, parchments, stained glasses, and statues. We report here the use of a number of modern surface science techniques (especially those using lasers, mass spectrometry, and microscopy) to characterize and analyze both normal and degraded daguerreotypes. Then, attempts to use laser ablation techniques for cleaning and restoring damaged nineteenth century samples will be described. The optimal wavelength, pulse length, pulse energy, and focussing conditions are critical for effective cleaning while preventing damage to the fragile image. (C) 2000 Editions scientifiques et medicales Elsevier SAS C1 [Golovlev, Valerie V.; Gresalfi, Michael J.; Miller, John C.] Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. [Romer, Grant] Int Museum Photog & Film, Rochester, NY 14607 USA. [Messier, Paul] Boston Art Conservat, Boston, MA 02135 USA. RP Miller, JC (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 2008, Oak Ridge, TN 37831 USA. EM jjm@ornl.gov FU Office of Biological and Environmental Research, US Department of Energy (DOE) [DE-AC05-96OR22464]; Lockheed Martin Energy Research Corporation; Oak Ridge National Laboratory; NATO [CRG 950660] FX Research is sponsored by the Office of Biological and Environmental Research, US Department of Energy (DOE) under contract number DE-AC05-96OR22464 with Lockheed Martin Energy Research Corporation. Funding was provided by the Laboratory Directed Research and Development Program at Oak Ridge National Laboratory. JCM acknowledges the use of a NATO International Collaboration Grant (CRG 950660) during the course of this work and also helpful discussions with J. Asmus, C. Fotakis and V. Zapfiropulos. D. L. Hogan (Coe College) is acknowledged for her collaboration on some of the mass spectrometry. C. S. Feigerle and J. A. Chaney (University of Tennessee) are acknowledged for their assistance with the electron microscopy and SERS studies. T. Vo-Dinh and D. L. Stokes (Oak Ridge National Laboratory) are also acknowledged for their assistance with the SERS studies. NR 13 TC 7 Z9 7 U1 2 U2 5 PU ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 1296-2074 J9 J CULT HERIT JI J. Cult. Herit. PD AUG PY 2000 VL 1 SU 1 BP S139 EP S144 AR PII S1296-2074(00)00185-0/FLA DI 10.1016/S1296-2074(00)00185-0 PG 6 WC Archaeology; Art; Chemistry, Analytical; Geosciences, Multidisciplinary; Materials Science, Multidisciplinary; Spectroscopy SC Archaeology; Art; Chemistry; Geology; Materials Science; Spectroscopy GA V20HY UT WOS:000208132300020 ER PT J AU Petersen, L Hofmann, P Plummer, EW Besenbacher, F AF Petersen, L Hofmann, P Plummer, EW Besenbacher, F TI Fourier transform-STM: determining the surface Fermi contour SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; SCANNING-TUNNELING-MICROSCOPY; 2-DIMENSIONAL ELECTRON-GAS; RECONSTRUCTED AU(111) SURFACE; STANDING-WAVE FORMATION; INVERSE PHOTOEMISSION; FRIEDEL-OSCILLATIONS; DENSITY WAVES; METAL-SURFACE; STATE BAND AB Surface states that cross the Fermi level give rise to a surface Fermi contour, in complete analogy with the notion of a bulk Fermi surface for metals. The shape of the Fermi contour is important when discussing the screening at the surface, Fermi surface nesting, Kohn anomalies, etc. To determine the Fermi contour, the usual technique of choice has been angle-resolved photoemission. Recently, we have introduced a new and simple method for determining surface Fermi contours. It is based on a Fourier Transform of STM images obtained at low bias voltage and low temperature. Here we review the results obtained so far, and discuss the method in comparison to photoemission. Finally, we suggest that Fourier Transform-STM can be a valuable tool for studying periodicities in the electronic structure of materials, e.g. charge density waves and charge ordering. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. Aarhus Univ, Ctr Atom Scale Mat Phys, DK-8000 Aarhus, Denmark. Aarhus Univ, Inst Storage Ring Facil, DK-8000 Aarhus C, Denmark. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Petersen, L (reprint author), Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. RI Besenbacher, Flemming/A-9623-2010; Hofmann, Philip/B-5938-2008 OI Hofmann, Philip/0000-0002-7367-5821 NR 72 TC 40 Z9 40 U1 2 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD AUG PY 2000 VL 109 IS 1-2 BP 97 EP 115 DI 10.1016/S0368-2048(00)00110-9 PG 19 WC Spectroscopy SC Spectroscopy GA 345TY UT WOS:000088832300009 ER PT J AU Song, HG Morris, JW McCormack, MT AF Song, HG Morris, JW McCormack, MT TI The microstructure of ultrafine eutectic Au-Sn solder joints on Cu SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE Au-Sn solder; ternary Au-Cu-Sn compounds; aging treatments AB The present work studies the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder on Cu. The study includes solder bumps 140-145 mu m in diameter and 55-65 mu m tall deposited on Cu-plated Sit and solder joints 60 mu m in diameter and 25 mu m in height that join Cu-plated ceramic and polyimide substrates. The results show that the microstructure is strongly affected by the addition of Ou from the substrate during reflow, which produces a thick intermetallic layer along the interface. In the case of the joints, normal processing produces a coarse microstructure that includes only a few grains between thick intermetallic coatings. Aging at high temperature causes a further monotonic increase in Cu content, which alters the intermetallic structure at the inter faces and call lead to intermetallic bridging across the joint. Thermal fatigue tests suggest that cyclic deformation breaks up the intermetallic structure, increasing the rate of Cu addition to the joint, but refining the apparent grain size. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. Fujitsu Comp Packaging Technol, San Jose, CA 95134 USA. RP Song, HG (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. NR 10 TC 26 Z9 26 U1 3 U2 9 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 AUG PY 2000 VL 29 IS 8 BP 1038 EP 1046 DI 10.1007/s11664-000-0170-9 PG 9 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 349QR UT WOS:000089057600007 ER PT J AU Fir, BA Gerken, M Pointner, BE Mercier, HPA Dixon, DA Schrobilgen, GJ AF Fir, BA Gerken, M Pointner, BE Mercier, HPA Dixon, DA Schrobilgen, GJ TI An X-ray crystallographic study of [Xe2F3][SbF6] and dimorphism in [Xe2F3][AsF6]; and a density functional theory study of the Xe2F3+ cation SO JOURNAL OF FLUORINE CHEMISTRY LA English DT Article DE xenon; X-ray crystallography; dimorphism; density functional theory; vibrational spectroscopy ID EFFECTIVE CORE POTENTIALS; BOND ORDERS; MOLECULAR CALCULATIONS; XENON(II) COMPOUNDS; MAGNETIC-RESONANCE; CRYSTAL-STRUCTURES; SCF THEORY; ABINITIO; VALENCES; RAMAN AB The Xe2F3+ cation has been studied by X-ray crystallography with AsF6- and SbF6- as counter anions. The [Xe2F3][AsF6] Salt was found to be dimorphic with a monoclinic phase: C2/c, a=25.756(3) Angstrom, b=8.556(1) Angstrom, c=15.356(2) Angstrom, beta=126.592(5)degrees, V=2716.9(6) Angstrom(3), Z=12 and R-1=0.0389 at -127 degrees C; and a trigonal phase: P3(2)21, a=8.602(5) Angstrom, c=10.665(9) Angstrom, V=683.4(8) Angstrom(3), 2=3 and R-1=0.0385 at -116 degrees C. The [Xe2F3][SbF6] salt crystallizes in the monoclinic system: Clc, a=14.575(2) Angstrom, b=8.1081(12) Angstrom, c=9.926(14) Angstrom, beta=130.360(3)degrees, V=899.8(2) Angstrom(3), Z=4 and R-1=0.0319 at -127 degrees C. The Xe ... F-b... Xe bridge angle of the V-shaped Xe2F3+ cation was found to vary from 139.8(8) to 160.3(3)degrees in trigonal [Xe2F3][AsF6] and [Xe2F3][SbF6], respectively. The variation in the Xe ... F-b... Xe bridge angle is attributed to crystal packing effects. The geometry and vibrational frequencies of the Xe2F3+ cation were calculated using density functional theory methods, confirming the experimental evidence for the facile deformation of the Xe ... F-b... Xe bridge angle. The vibrational spectrum of Xe2F3+ has been reassigned based on the theoretical calculations. (C) 2000 Elsevier Science S.A. All rights reserved. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP McMaster Univ, Dept Chem, 1280 Main St W, Hamilton, ON L8S 4M1, Canada. EM schrobil@mcmaster.ca NR 36 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-1139 EI 1873-3328 J9 J FLUORINE CHEM JI J. Fluor. Chem. PD AUG PY 2000 VL 105 IS 1 BP 159 EP 167 DI 10.1016/S0022-1139(00)00306-7 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 349QU UT WOS:000089057700026 ER PT J AU Lario, D Marsden, RG Sanderson, TR Maksimovic, M Sanahuja, B Balogh, A Forsyth, RJ Lin, RP Gosling, JT AF Lario, D Marsden, RG Sanderson, TR Maksimovic, M Sanahuja, B Balogh, A Forsyth, RJ Lin, RP Gosling, JT TI Energetic proton observations at 1 and 5 AU 1. January-September 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID COROTATING INTERACTION REGIONS; CORONAL MASS EJECTIONS; SOLAR-WIND; PARTICLE EVENTS; MAGNETIC-FIELD; INTERPLANETARY SHOCKS; ION ENHANCEMENTS; ULYSSES; ACCELERATION; HELIOSPHERE AB We present energetic particle observations by the Ulysses and Wind spacecraft during the years 1997-1998. During this period, Ulysses moved from +19 degrees to -19 degrees in heliographic latitude with heliocentric distances ranging from 4.71 to 5.41 AU. Wind was located near the Earth at 1 AU from the Sun in the ecliptic plane. The proximity of Ulysses to the ecliptic plane allows us to compare proton fluxes at different heliospheric distances and heliolongitudes but at similar latitudes, Enhancements in the energetic (approximately MeV) MeV proton fluxes were observed by both spacecraft in a close temporal association, We quantify this temporal coincidence and we distinguish two time intervals based on the energy range of the proton flux increases and on the solar wind streams observed by the Ulysses spacecraft. Each one of these two periods (period 1, January-September 1997 and period 2, October 1997 to December 1998) corresponds also to a different level of solar activity. We establish a direct correspondence between individual particle flux enhancements observed by both spacecraft throughout period 1, At 1 AU the proton flux enhancements are associated with the occurrence of coronal mass ejections (CMEs) at the Sun. At 5 AU the presence of high-speed solar wind streams, the contribution of energetic particles from CMEs, and the evolution of the magnetic field structures along which energetic particles propagate determine the final shape of the proton flux enhancements and their time delays with respect to 1 AU. When a solar energetic particle (SEP) event is observed at 1 AU, particle flux enhancements associated with recurrent high-speed solar wind streams at similar to 5 AU show a higher particle flux intensity. We suggest that SEPs accelerated by CME-driven shocks act as a background seed particle population available to be reaccelerated by shocks associated with corotating high-speed streams. C1 European Space Agcy, Estec, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. Univ Barcelona, Dept Astron & Meteorol, E-08028 Barcelona, Spain. Inst Estudis Espacials Catalunya, Barcelona, Spain. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lario, D (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. RI Lario, David/D-9318-2016 OI Lario, David/0000-0002-3176-8704 NR 36 TC 12 Z9 12 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 AUG 1 PY 2000 VL 105 IS A8 BP 18235 EP 18250 DI 10.1029/1999JA000373 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600006 ER PT J AU Lario, D Marsden, RG Sanderson, TR Maksimovic, M Sanahuja, B Plunkett, SP Balogh, A Forsyth, RJ Lin, RP Gosling, JT AF Lario, D Marsden, RG Sanderson, TR Maksimovic, M Sanahuja, B Plunkett, SP Balogh, A Forsyth, RJ Lin, RP Gosling, JT TI Energetic proton observations at 1 and 5 AU 2. Rising phase of the solar cycle 23 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTION; PARTICLE EVENTS; INTERPLANETARY SHOCKS; DRIVEN SHOCKS; COSMIC-RAYS; ULYSSES; WIND; FLARES; PROPAGATION; SPACECRAFT AB The increasing level of solar activity at the end of 1997 coincides with the observation of solar energetic particle (SEP) events by the Wind and Ulysses spacecraft. The proximity of Ulysses to the ecliptic plane during this period allows us to study the effects of the solar activity at two different heliolongitudinal and heliocentric distances but at similar heliolatitudes. We identify the main transient proton enhancements seen by Wind and Ulysses from October 1997 to the end of December 1998, We compare their characteristics and suggest an interpretation in terms of their heliospheric location, the activity occurring at the Sun, and the conditions for particle propagation between the Sun and both spacecraft. Whereas at 1 RU different SEP events can be associated with individual coronal mass ejections (CMEs), at 5 AU long-lasting SEP events are observed while a sequence of CMEs takes place at the Sun, Continuous injection of particles from traveling CME-driven shocks, the effects of particle propagation along interplanetary magnetic field lines, acid the corotation of these field lines across the Ulysses location are the main factors responsible for these long-lasting periods of high particle intensity observed by Ulysses. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Barcelona, Dept Astron & Meteorol, Barcelona, Spain. Inst Estudis Espacials Catalunya, Barcelona, Spain. Univ Space Res Assoc, Naval Res Lab, Washington, DC USA. Imperial Coll Sci & Technol, Blackett Lab, London, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. European Space Agcy, Estec, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. RP Lario, D (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. RI Lario, David/D-9318-2016 OI Lario, David/0000-0002-3176-8704 NR 45 TC 18 Z9 17 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 AUG 1 PY 2000 VL 105 IS A8 BP 18251 EP 18274 DI 10.1029/1999JA000374 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600007 ER PT J AU Sanderson, TR Erdos, G Balogh, A Forsyth, RJ Marsden, RG Gosling, JT Phillips, JL Tranquille, C AF Sanderson, TR Erdos, G Balogh, A Forsyth, RJ Marsden, RG Gosling, JT Phillips, JL Tranquille, C TI Effect of magnetic discontinuities on the propagation of energetic particles: Ulysses observations of the onset of the March 1991 solar particle event SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WAVES; HELIOSPHERE AB We present observations of energetic ions from the Cosmic Ray and Solar particle Investigation (COSPIN) and Heliosphere Instrument for Spectra Composition and Anisotropy at Law Energy (HISCALE) instruments on board the Ulysses spacecraft. We examine ill detail the onset of energetic ions observed during the March 1991 series of solar events. Active region 6555, at E28 at 2247 UT on March 22, 1991 (day 81), was most likely responsible for the high-energy protons subsequently seen at Ulysses. A slow increase in the high-energy (similar to 50 MeV) proton intensity, made up of many small but rapid intensity increases, began around 9 hours after the onset of the event, taking 1.5 days to reach maximum intensity. On the flank, and in front of a coronal mass ejection (CME), coming From a previous event, we observed a region with a drop in the magnetic field strength. This region was populated with hot shocked plasma and, owing to the low magnetic field pressure, had an ion plasma beta >1. Mirror mode waves, with discontinuities appearing at the edges of the waves, produced a larger-than-average number of magnetic field discontinuities, a large fraction of the discontinuities being aligned with their normals oriented along the radial direction, suggesting that they were being convected outward by the CME. These discontinuities acted as a series of barriers to the propagation of the energetic solar particles coming from the solar event, delaying substantially the onset of the particle event at Ulysses. C1 Estec, Dept Space Sci, NL-2220 AG Noordwijk, Netherlands. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. KFKI, Res Inst Particle & Nucl Phys, H-1525 Budapest, Hungary. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sanderson, TR (reprint author), Estec, Dept Space Sci, Keplerlaan 1,Postbus 299, NL-2220 AG Noordwijk, Netherlands. NR 15 TC 7 Z9 6 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 AUG 1 PY 2000 VL 105 IS A8 BP 18275 EP 18283 DI 10.1029/1999JA000115 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600008 ER PT J AU Maksimovic, M Gary, SP Skoug, RM AF Maksimovic, M Gary, SP Skoug, RM TI Solar wind electron suprathermal strength and temperature gradients: Ulysses observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID VELOCITY DISTRIBUTION-FUNCTIONS; THERMAL NOISE SPECTROSCOPY; HELIOS PLASMA-EXPERIMENT; GLOBAL PROCESSES; ION-EXOSPHERE; HEAT-FLUX; PARAMETERS; MODEL; 1-AU; DENSITY AB We use observations from the Ulysses electron spectrometer to examine global trends of the electron suprathermal population and to study, for the fi rst time, the electron core, halo, and total temperature gradients in the fast solar wind over the poles. We use a data set covering the period from the beginning of the mission ( 1990, day of year 322) to approximately the first completion of Ulysses out of-ecliptic orbit around the Sun (1998, day 32). This allows us to characterize very welll the two states of the solar wind: the high-speed wind, emanating from polar coronal holes , and the low-speed streams, emanating from equatorial regions. From a classical bi-Maxwellian (core and halo) model of electron velocity distribution functions, we define the electron suprathermal strength S as the ratio of the halo to core kinetic pressures: S = n(h)T(h)/n(c)T(c). The fast wind has larger average values of S than the slow wind. This global correlation between S and the solar wind hulk speed is also observed on a smaller scale in the polar regions. We find that the small-scale variations of the solar wind bulk speed in the polar regions, typically +/-50 kin/s around an average value, of 750 km/s, are correlated with small-scale variations of S. We present also the first observations of the electron core, halo, and total temperature gradients in time-stationary fast solar wind periods over the poles, We examine all the previous observations in the context of simple solar wind exospheric models. We find, for instance, that the total electron temperature can be well fitted by a law of the form T-c = T-0 + T-1 r(-4/3), as predicted by the exospheric approximation. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. DESPA, Observ Paris Meudon, CNRS UMR 8632, F-92195 Meudon, France. RP Maksimovic, M (reprint author), European Space Agcy, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. NR 39 TC 67 Z9 67 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 2000 VL 105 IS A8 BP 18337 EP 18350 DI 10.1029/2000JA900039 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600014 ER PT J AU Korth, A Friedel, RHW Mouikis, CG Fennell, JF Wygant, JR Korth, H AF Korth, A Friedel, RHW Mouikis, CG Fennell, JF Wygant, JR Korth, H TI Comprehensive particle and field observations of magnetic storms at different local times from the CRRES spacecraft SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRIC-FIELD; GEOSYNCHRONOUS ORBIT; GEOMAGNETIC-ACTIVITY; DYNAMICS; ION; INSTRUMENT; REGION; SCALE; BELT AB The response of ring current intensification to three magnetic storms sampled at dawn, midnight, and dusk is investigated. We use a comprehensive set of data from the CRRES satellite, using plasma, energetic particle (ion composition), electric field, and magnetic field data, which is ideal for investigating the interrelationship between the ring current strength as measured by D-st, the particle (current carriers) in the outer radiation belt, their effects on the global magnetic field, and the convection effects caused by large dawn-dusk electric fields. This yields a comprehensive and self-consistent picture of storm time radiation belt formation based entirely on data. At all local times investigated strong, stretching (flattening) of the magnetic field down to L < 4 is observed during the storm main phase, showing that this field line stretching is not limited to midnight. Ring current ions above 100 keV are shown to form a partial ring current during the main phase as they are only sampled at dawn during the recovery phase when the electric field vanishes. Comparing this feature to Kp-dependent models of the proton Alfven layer shows that dawn is only accessible to these ions after the main phase. Ionospheric origin ions (O+) follow dynamics very similar to those of H+, indicating a source in the plasma sheet. Solar wind ions (He++) are controlled by their solar wind source and have immediate access during the main phase. He+, which is generated in the ionosphere as well as by charge exchange, has behavior similar to that of O+ and H+. In contrast to the current view, plasma sheet ions in the energy range from 5 to 28 keV contribute significantly in the energy density of the ring current during the storm main phase. C1 Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Aerospace Corp, Los Angeles, CA 90009 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Korth, A (reprint author), Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. RI Friedel, Reiner/D-1410-2012 OI Friedel, Reiner/0000-0002-5228-0281 NR 28 TC 33 Z9 32 U1 1 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 AUG 1 PY 2000 VL 105 IS A8 BP 18729 EP 18740 DI 10.1029/1999JA000430 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600044 ER PT J AU Zaharia, S Cheng, CZ Johnson, JR AF Zaharia, S Cheng, CZ Johnson, JR TI Particle transport and energization associated with substorms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CURRENT DISRUPTION; DRIFT ECHOES; MARCH 24; 1991 SSC; SIMULATION; INJECTIONS; FIELDS; PLASMA; ONSET; ION AB Energetic particle flux enhancement events observed by satellites during substorms are studied by considering the interaction of particles with earthward propagating electromagnetic pulses of westward electric field and consistent magnetic field of localized radial and azimuthal extent in a background magnetic field. The energetic particle flux enhancement is mainly due to the betatron acceleration process: particles are swept by the earth-ward propagating electric field pulses via the E x B drift toward the Earth to higher magnetic field locations and are energized because of magnetic moment conservation. The most energized particles are those which stay in the pulse for the longest time and are swept the longest radial distance toward the Earth. Assuming a constant propagating velocity of the pulse, we obtain analytical solutions of particle orbits. We closely examine substorm energetic particle injection by computing the particle flux and comparing with geosynchronous satellite observations. Our results show that for pulse parameters leading to consistency with observed flux values, the bulk of the injected particles arrive fi om distances of less than 9 R-E, which is closer to the Earth than the values obtained Ly the previous model (Li et al., 1998). C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Zaharia, S (reprint author), Princeton Univ, Plasma Phys Lab, POB 451,James Forrestal Campus, Princeton, NJ 08543 USA. RI Cheng, Chio/K-1005-2014 NR 20 TC 44 Z9 44 U1 1 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 AUG 1 PY 2000 VL 105 IS A8 BP 18741 EP 18752 DI 10.1029/1999JA000407 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600045 ER PT J AU Jorgensen, AM Kepko, L Henderson, MG Spence, HE Reeves, GD Sigwarth, JB Frank, LA AF Jorgensen, AM Kepko, L Henderson, MG Spence, HE Reeves, GD Sigwarth, JB Frank, LA TI Association of energetic neutral atom bursts and magnetospheric substorms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RING CURRENT; LOW ALTITUDES; POLAR; IMAGES; STORM AB In this paper we present evidence that short-lived bursts of energetic neutral atoms (ENAs) observed with the Comprehensive Energetic Particle and Pitch Angle Distribution/Imaging Proton Spectrometer (CEPPAD/IPS) instrument on the Polar spacecraft are signatures of substorms. The IPS was designed primarily to measure ions in situ, with energies between 17.5 and 1500 keV. However, it has also proven to be a very capable ENA imager in the range 17.5 keV to a couple hundred keV. It was expected that some ENA signatures of the storm time ring current would be observed. Interestingly, IFS also routinely measures weaker, shorter-lived, and more spatially confined bursts of ENAs with duration from a few tens of minutes to a few hours and appearing once or twice a day. One of these bursts tvas quickly associated with magnetospheric and auroral substorm activity and has been reported in the literature [Henderson et al., 1997]. In this paper we characterize ENA bursts observed from Polar and establish statistically their association with classic substorm signatures (global auroral onsets, electron and ion injections, AL drops, and Pi2 onsets). We conclude that similar to 90% of the observed ENA bursts are associated with classic substorms and thus represent a new type of substorm signature. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Jorgensen, AM (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. RI Kepko, Larry/D-7747-2012; Spence, Harlan/A-1942-2011; Reeves, Geoffrey/E-8101-2011; Henderson, Michael/A-3948-2011; OI Kepko, Larry/0000-0002-4911-8208; Reeves, Geoffrey/0000-0002-7985-8098; Henderson, Michael/0000-0003-4975-9029; Spence, Harlan/0000-0002-2526-2205 NR 24 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 2000 VL 105 IS A8 BP 18753 EP 18763 DI 10.1029/1999JA000445 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600046 ER PT J AU Mao, SS Greif, R Mao, XL Russo, RE AF Mao, SS Greif, R Mao, XL Russo, RE TI Plasma development during picosecond laser processing of electronic materials SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 4th Conference on Heat Transfer Photogallery held at the 1999 International Mechanical Engineering Congress and Exhibition CY NOV, 1999 CL NASHVILLE, TEXAS C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Mao, SS (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD AUG PY 2000 VL 122 IS 3 BP 424 EP 424 DI 10.1115/1.1289642 PG 1 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 430PR UT WOS:000168583800004 ER PT J AU Bissig, KD Marti, U Solioz, M Forestier, M Zimmermann, H Luthi, M Reichen, J AF Bissig, KD Marti, U Solioz, M Forestier, M Zimmermann, H Luthi, M Reichen, J TI Epidermal growth factor is decreased in liver of rats with biliary cirrhosis but does not act as paracrine growth factor immediately after hepatectomy SO JOURNAL OF HEPATOLOGY LA English DT Article DE acinus; cholangiocytes; immunohistochemistry; regeneration; reverse transcription polymerase chain reaction ID FACTOR RECEPTOR; MESSENGER-RNA; EPITHELIAL-CELLS; REGENERATION; EXPRESSION; STIMULATION; HEPATOCYTES; INCREASES; MODEL; MASS AB Background/Aims: Epidermal growth factor, a potent mitogen for hepatocytes and cholangiocytes, is thought to act as an immediate-early gene after partial hepatectomy, Since regeneration is impaired in cirrhosis, we explored the expression of epidermal growth factor in cirrhotic rat liver immediately after partial hepatectomy, Methods: Cirrhosis was induced by bile duct ligation (n=21); sham-operated animals served as controls (n=21), Twenty-five days after initial surgery animals were subjected to 70% partial hepatectomy or sham operation; the liver was sampled before surgery and 20, 40 and 90 min thereafter. Epidermal growth factor mRNA levels were assessed by quantitative reverse transcription polymerase chain reaction, Protein expression was estimated by immunohistochemistry using a polyclonal antibody against epidermal growth factor. Results: Before hepatectomy, epidermal growth factor mRNA averaged 70.3+/-39.9 pg/mu g of total RNA in controls; this was markedly decreased to 21.9+/-12.7 pg/mu g RNA in bile duct ligation (p<0.01), Epidermal growth factor mRNA did not increase after partial hepatectomy in either group, with the exception of sham-operated controls. Immunohistochemistry revealed that partial hepatectomy had no effect on epidermal growth factor expression. Hepatocytes showed uniformly cytosolic epidermal growth factor in controls, while in bile duct ligation immunostaining was faint or absent. Cholangiocytes exhibited a strong cytosolic staining in all experimental groups. Conclusions: The present study shows that epidermal growth factor is reduced in the cirrhotic liver, This could contribute to the loss of parenchymal liver tissue observed in cirrhosis. The lack of up-regulation after PH sheds doubt on the role of epidermal growth factor as an immediate-early gene in hepatic regeneration. Further, we demonstrate that epidermal growth factor accumulates in cholangiocytes. This observation is strong evidence for involvement of the mitogen epidermal growth factor in the proliferation of bile ducts during cirrhogenesis. C1 Univ Bern, Dept Clin Pharmacol, CH-3010 Bern, Switzerland. Natl Renewable Energy Lab, Golden, CO USA. RP Reichen, J (reprint author), Univ Bern, Dept Clin Pharmacol, Murtenstr 35, CH-3010 Bern, Switzerland. RI Solioz, Marc/I-3162-2013 OI Solioz, Marc/0000-0002-7989-6721 NR 32 TC 9 Z9 9 U1 2 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0168-8278 J9 J HEPATOL JI J. Hepatol. PD AUG PY 2000 VL 33 IS 2 BP 275 EP 281 DI 10.1016/S0168-8278(00)80368-2 PG 7 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 339BN UT WOS:000088457900012 PM 10952245 ER PT J AU Shiratori, Y Perelson, AS Weinberger, L Imazeki, F Yokosuka, O Nakata, R Ihori, M Hirota, K Ono, N Kuroda, H Motojima, T Nishigaki, M Omata, M AF Shiratori, Y Perelson, AS Weinberger, L Imazeki, F Yokosuka, O Nakata, R Ihori, M Hirota, K Ono, N Kuroda, H Motojima, T Nishigaki, M Omata, M TI Different turnover rate of hepatitis C virus clearance by different treatment regimen using interferon-beta SO JOURNAL OF HEPATOLOGY LA English DT Article DE Amplicor-HCV monitor assay; HCV RNA level; interferon-beta; twice-a-day administration; viral dynamics ID LONG-TERM RESPONSE; DYNAMICS IN-VIVO; HCV-RNA; ALPHA-INTERFERON; THERAPY; SERUM; INFECTION; PREDICTORS; RIBAVIRIN; ALFA AB Background/Aim: Since patients with high viral load and HCV subtype Ib are known to respond poorly to interferon (IFN) therapy, the viral dynamics of HCV RNA after initiation of interferon therapy were examined in the present study with respect to two different administration regimens, once vs. twice a day. Methods: Twenty-two patients with chronic hepatitis C confirmed by liver biopsy and with >1 Meq/ml of HCV RNA and HCV subtype Ib were randomly assigned to two different IFN administration regimens (6 million units of IFN once a day or 3 million units of IFN twice a day), and the serum HCV RNA level was serially measured. Results: Graphs of HCV RNA levels vs treatment time showed an initial rapid fall, followed by a slower clearance phase. Fitting the data to a model for HCV decay proposed by Neumann et al, showed that the treatment efficacy was significantly higher with twice daily administration. Negativity for HCV RNA measured by Amplicor assay in the twice-a-day administration group was 18%, 73% and >89% at 1, 2 and 3 weeks, respectively, in contrast to 0%, 0%, and 18%, respectively, with once-a-day administration. However, a significant reduction of platelet count and albumin level, a marked increase in serum aspartate aminotransferase/alanine aminotransferase, and a high incidence of renal toxicity (proteinuria) were found in patients receiving IFN twice a day in comparison with those receiving it once a day, Conclusion: The twice-a-day administration of IFN accelerated the clearance of HCV RNA from serum, leading to a more efficient virological response for patients with chronic hepatitis C, but with a high rate of renal toxicity. C1 Univ Tokyo, Dept Internal Med, Gastroenterol Unit, Tokyo, Japan. Los Alamos Natl Lab, Los Alamos, NM USA. Chiba Univ, Sch Med, Dept Internal Med 1, Chiba 280, Japan. Japanese Red Cross Med Ctr, Div Gastroenterol, Tokyo, Japan. Mito Saiseikai Gen Hosp, Div Gastroenterol, Ibaraki, Osaka, Japan. Kyoundou Hosp, Sasaki Inst, Tokyo, Japan. Motojima Gen Hosp, Dept Med, Gunma, Japan. Univ Shizuoka, Sch Nursing, Shizuoka, Japan. RP Shiratori, Y (reprint author), Univ Tokyo, Dept Internal Med Gastroenterol, Bunkyo Ku, 7-3-1 Hongo, Tokyo 113, Japan. FU NCRR NIH HHS [RR06555] NR 37 TC 21 Z9 21 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-8278 J9 J HEPATOL JI J. Hepatol. PD AUG PY 2000 VL 33 IS 2 BP 313 EP 322 DI 10.1016/S0168-8278(00)80373-6 PG 10 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 339BN UT WOS:000088457900017 PM 10952250 ER PT J AU de Gouvea, A Murayama, H AF de Gouvea, A Murayama, H TI Determining the flavour content of the low-energy solar neutrino flux SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE solar and atmospheric neutrinos; neutrino physics ID OSCILLATIONS; MASSES; MAJORANA; DIRAC AB We study the sensitivity of the HELLAZ and Borexino solar neutrino experiments on discriminating the neutrino species nu (e), <()over bar>(e), nu (mu,tau), <()over bar>(mu,tau), and nu (s) using the difference in the recoil electron kinetic energy spectra in elastic neutrino-electron scattering. We find that one can observe a non-vanishing nu (mu,tau) component in the solar neutrino flux, especially when the nu (e) survival probability is low. Also, if the data turn out to be consistent with nu (e) <----> nu (mu,tau) oscillations, a <()over bar>(e) component can be excluded effectively. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP CERN, Div Theory, CH-1211 Geneva 23, Switzerland. EM andre.carvalho.de.gouvea@cern.ch; murayama@lbl.gov RI Murayama, Hitoshi/A-4286-2011 NR 42 TC 2 Z9 2 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 AUG PY 2000 IS 8 AR 025 PG 22 WC Physics, Particles & Fields SC Physics GA 423DJ UT WOS:000168159900025 ER PT J AU Kim, J Miller, NL Farrara, JD Hong, SY AF Kim, J Miller, NL Farrara, JD Hong, SY TI A seasonal precipitation and stream flow hindcast and prediction study in the western United States during the 1997/98 winter season using a dynamic downscaling system SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODEL; OROGRAPHIC PRECIPITATION; WEATHER PREDICTION; BOUNDARY-LAYER; SNOW BUDGET; RIVER FLOW; SIMULATION; CALIFORNIA; SCHEME; PARAMETERIZATION AB The authors present a seasonal hindcast and prediction of precipitation in the western United States and stream flow in a northern California coastal basin for December 1997-February 1998 (DJF) using the Regional Climate System Model (RCSM). In the seasonal hindcast simulation, in which the twice-daily National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis was used for the initial conditions and time-dependent boundary forcing, RCSM has simulated realistically the temporal and spatial variations of precipitation in California and stream flow in a northern California coastal basin. For the headwater basin of the Russian River in the northern California Coast Ranges, the Topography-Based Hydrologic Model (TOP-MODEL) forced by observed daily precipitation resulted in a correlation coefficient of 0.88 between observed and simulated DJF stream flow. In the coupled stream flow hindcast, the authors obtained a correlation coefficient of 0.7 between simulated and observed stream flow for the same period. The coupled hindcast has generally overestimated(underestimated) low (high) flow events in the basin. Errors in the simulated stream flow were due mostly to the errors in the simulated precipitation. A seasonal hydroclimate prediction experiment, in which RCSM was nested within the global forecast data from the University of California, Los Angeles, GCM, has predicted well the season-total precipitation in the western United States. Temporal variations of predicted precipitation were affected strongly by the predictability of the general circulation model. The predicted DJF-total snowfall agrees well with the snowfall simulated in the hindcast, especially in the central Cascades and the Sierra Nevada, where snowfall was the heaviest. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90024 USA. Natl Ctr Environm Predict, Environm Modeling Ctr, Camp Springs, MD USA. RP Kim, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS90-1116,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Hong, Song-You/I-3824-2012 NR 55 TC 44 Z9 44 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD AUG PY 2000 VL 1 IS 4 BP 311 EP 329 DI 10.1175/1525-7541(2000)001<0311:ASPASF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357VE UT WOS:000089520800002 ER PT J AU Xu, ZY Leong, KH Sanders, PG AF Xu, ZY Leong, KH Sanders, PG TI Laser surface alloying of silicon into aluminum casting alloys SO JOURNAL OF LASER APPLICATIONS LA English DT Article DE laser surface alloying; aluminum alloys; surface roughness; silicon ID WEAR AB Aluminum alloys that are easily castable tend to have lower silicon content, and hence, lower wear resistance. The use of laser surface alloying to improve the surface wear resistance of 319 and 320 aluminum alloys was examined. A silicon layer was painted onto the surface to be treated. A high power pulsed Nd:yttrium-aluminum-garnet laser with fiber-optic beam delivery was used to carry out the laser surface treatment to enhance the silicon content and produce a very fine silicon-rich phase. One advantage of using a pulsed laser beam to carry out the surface alloying is it provides a vigorous turbulence in the molten pool and enhances the dissolution of the fine silicon into the molten bath and its dispersal in a short process time. Process parameters were varied to obtain smooth single treated tracks and minimize the surface roughness from overlap of the treated tracks. Our goal is to take advantage of the vigorous turbulence characteristic of the pulsed beam to obtain desired microstructure of laser-alloyed layers, and at the same time to employ the pulse parameters that mimic continuous wave operation as closely as possible to produce the smooth surface. The surface-alloyed layer was characterized and the silicon content and microhardness profile were determined. (C) 2000 Laser Institute of America. [S1042-346X(00)00503-9]. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. RP Xu, ZY (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 4 Z9 5 U1 0 U2 3 PU LASER INST AMER PI ORLANDO PA 13501 INGENUITY DR, SUITE 128, ORLANDO, FL 32826 USA SN 1042-346X J9 J LASER APPL JI J. Laser Appl. PD AUG PY 2000 VL 12 IS 4 BP 166 EP 170 PG 5 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA 343JN UT WOS:000088699400006 ER PT J AU Kevrekidis, PG Bishop, AR Rasmussen, KO AF Kevrekidis, PG Bishop, AR Rasmussen, KO TI Parametric quantum resonances for Bose-Einstein condensates SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID COLLECTIVE EXCITATIONS; GAS; TEMPERATURE AB We generalize recent work on parametric resonances of nonlinear Schrodinger (NLS) type equations to the case of three dimensional Bose-Einstein condensates at zero temperatures. We show the possibility of such resonances in the three-dimensional case, using a moment method and numerical simulations. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Rasmussen, KO (reprint author), Rutgers State Univ, Dept Phys & Astron, 136 Frelinghuysen Rd, Piscataway, NJ 08854 USA. RI Rasmussen, Kim/B-5464-2009 OI Rasmussen, Kim/0000-0002-4029-4723 NR 25 TC 9 Z9 9 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD AUG PY 2000 VL 120 IS 3-4 BP 205 EP 212 DI 10.1023/A:1004629510124 PG 8 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 371BV UT WOS:000165158600002 ER PT J AU Woelk, K Zwank, BLJ Trautner, P Lehnhof, E Bargon, J Klingler, RJ Gerald, RE Rathke, JW AF Woelk, K Zwank, BLJ Trautner, P Lehnhof, E Bargon, J Klingler, RJ Gerald, RE Rathke, JW TI Finite-difference approach for the high-precision analysis of rotating-frame diffusion images SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE diffusion; rotating-frame imaging; NMR microscopy; magnetization grating; finite difference; toroid cavity ID RADIOFREQUENCY FIELD GRADIENT; MOLECULAR-DIFFUSION; NMR MICROSCOPY; MAGNETIZATION; DELIVERY; MOTION AB A finite-difference approach has been developed for precisely determining diffusion coefficient and T-1 relaxation time in fluid samples analyzed by magnetization-grating rotating-frame imaging (MAGROFI) with either a surface coil or a toroid cavity detector (TCD). This approach avoids shortcomings of phenomenologically based approximations, such as neglect of sample geometries with singularities at the confines of the sample volume, and accounts for the diffusive edge enhancement observed in fluid imaging. Error limits are discussed. The new method has been applied to the determination of the self-diffusion coefficient for MAGROFI experiments using TCDs filled with acetone. (C) 2000 Academic Press. C1 Univ Bonn, Inst Phys & Theoret Chem, D-53115 Bonn, Germany. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Woelk, K (reprint author), Univ Bonn, Inst Phys & Theoret Chem, Wegelerstr 12, D-53115 Bonn, Germany. NR 40 TC 11 Z9 11 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD AUG PY 2000 VL 145 IS 2 BP 276 EP 290 DI 10.1006/jmre.2000.2106 PG 15 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 346JK UT WOS:000088867100013 ER PT J AU Roy, M Mitchell, JF Potashnik, SJ Schiffer, P AF Roy, M Mitchell, JF Potashnik, SJ Schiffer, P TI Field dependent specific-heat of rare earth manganites SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE colossal magnetoresistance; manganites; specific heat ID METAL-INSULATOR-TRANSITION; TEMPERATURE SPECIFIC-HEAT; PHASE-SEPARATION; COLOSSAL MAGNETORESISTANCE; MN-55 NMR; DOUBLE-EXCHANGE; MAGNETIC-FIELD; DOPED LAMNO3; CHARGE; LA0.5CA0.5MNO3 AB The low-temperature specific heat C(H) of several rare-earth manganites (La0.7Sr0.3MnO3, Nd0.5Sr0.5MnO3, Pr0.5Sr0.5MnO3, La0.67Ca0.33MnO3, La0.5Ca0.5MnO3, La0.33Ca0.67MnO3 and La0.33Ca0.67MnO3) was measured as a function of magnetic field. We observed behavior consistent with thermodynamic expectations, i.e., C(H) decreases with field for ferromagnetic metallic compounds by an amount which is in quantitative agreement with spin-wave theory. We also find that C(H) increases with held in most compounds with a charge-ordered antiferromagnetic ground state. In compounds which show evidence of a coexistence of ferromagnetic metallic and antiferromagnetic charge-ordered states, C(H) displays some unusual non-equilibrium effects presumably associated with the phase-separation of the two states. We also observe a large anomalous low-temperature specific heat at the doping-induced metal-insulator transition (at x = 0.50) in La1-xCaxMnO3. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Schiffer, P (reprint author), Univ Notre Dame, Dept Phys, 225 Nieuwland Sci Hall, Notre Dame, IN 46556 USA. RI Schiffer, Peter/F-3227-2011; OI Schiffer, Peter/0000-0002-6430-6549 NR 45 TC 16 Z9 17 U1 0 U2 3 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 AUG PY 2000 VL 218 IS 2-3 BP 191 EP 197 DI 10.1016/S0304-8853(00)00393-0 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 339QN UT WOS:000088489600009 ER PT J AU Ehrenberg, H Wltschek, G Theissmann, R Weitzel, H Fuess, H Trouw, F AF Ehrenberg, H Wltschek, G Theissmann, R Weitzel, H Fuess, H Trouw, F TI The magnetic structure of FeNbO4 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE spin arrangements; antiferromagnetics AB The antiferromagnetic structure of FeNbO4 was determined by neutron powder diffraction. The magnetic unit cell is doubled with respect to the crystallographic one, k = (1/2 0 0), and the magnetic moments are collinear aligned in the ac-plane with an angle phi a = 75(15)degrees to the a-axis. The Neel temperature of T-N = 38.5(5)K and the extrapolated zero-temperature moment of 1.90(5)mu(B) per Fe-site are fitted to the temperature dependence of the sublattice magnetisation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Tech Univ Darmstadt, Dept Mat Sci, D-64287 Darmstadt, Germany. Univ Cambridge, Interdisciplinary Res Ctr Superconduct, Cambridge CB3 0HE, England. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Ehrenberg, H (reprint author), Tech Univ Darmstadt, Dept Mat Sci, Petersenstr 23, D-64287 Darmstadt, Germany. RI Ehrenberg, Helmut/M-7090-2013 OI Ehrenberg, Helmut/0000-0002-5134-7130 NR 12 TC 10 Z9 10 U1 1 U2 9 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 AUG PY 2000 VL 218 IS 2-3 BP 261 EP 265 DI 10.1016/S0304-8853(00)00395-4 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 339QN UT WOS:000088489600018 ER PT J AU Biggs, JR Bennett, KD Mullen, MA Haarmann, TK Salisbury, M Robinson, RJ Keller, D Torrez-Martinez, N Hjelle, B AF Biggs, JR Bennett, KD Mullen, MA Haarmann, TK Salisbury, M Robinson, RJ Keller, D Torrez-Martinez, N Hjelle, B TI Relationship of ecological variables to Sin Nombre virus antibody seroprevalence in populations of deer mice SO JOURNAL OF MAMMALOGY LA English DT Article DE competition; Peromyscus maniculatus; plant cover; Sin Nombre virus ID MOUSE PEROMYSCUS-MANICULATUS; SOUTHWESTERN UNITED-STATES; HEMORRHAGIC-FEVER; RENAL SYNDROME; HANTAVIRUS; IDENTIFICATION; CALIFORNIA; FOOD AB Because recent studies have not demonstrated a strong relationship between rodent density and Sin Nombre virus (SNV) seroprevalence, there is speculation that seroprevalence may be related to other factors, including habitat quality and food availability. We evaluated densities of deer mice (Peromyscus maniculatus), plant cover and biomass, and terrestrial arthropod biomass at 2 sites in the southwestern United States to identify factors that may affect the seroprevalence rate of SNV within a rodent population. Seroprevalence differed significantly between years. Although interaction of deer-mouse density, plant cover and biomass, and arthropod biomass was not a strong predictor of seroprevalence (R-2 = 0.64, P = 0.04), we observed a significant contribution to a repeated-measures model by deer-mouse density (P = 0.02), Our data suggest that as rodent density increases, so does the seroprevalence rate within that population. Although not significantly correlated, we observed the lowest levels of arthropod biomass when seroprevalence was highest. Based on our results, evaluating changes in habitat quality and incorporating measurement of local ecological variables with studies of fluctuations in rodent density may aid in predicting human outbreaks of hantavirus disease. C1 Univ Calif Los Alamos Natl Lab, Ecol Grp, Los Alamos, NM 87545 USA. Univ New Mexico, Sch Med, Albuquerque, NM 87131 USA. RP Biggs, JR (reprint author), Univ Calif Los Alamos Natl Lab, Ecol Grp, POB 1663, Los Alamos, NM 87545 USA. NR 27 TC 17 Z9 18 U1 0 U2 5 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD AUG PY 2000 VL 81 IS 3 BP 676 EP 682 DI 10.1644/1545-1542(2000)081<0676:ROEVTS>2.3.CO;2 PG 7 WC Zoology SC Zoology GA 347BR UT WOS:000088907500005 ER PT J AU de la Mora, JF Van Berkel, GJ Enke, CG Cole, RB Martinez-Sanchez, M Fenn, JB AF de la Mora, JF Van Berkel, GJ Enke, CG Cole, RB Martinez-Sanchez, M Fenn, JB TI Electrochemical processes in electrospray ionization mass spectrometry - Discussion SO JOURNAL OF MASS SPECTROMETRY LA English DT Article ID CURRENT ELECTROLYTIC PROCESS; CHARGED DROPLETS; ION-SOURCE; GAS-PHASE; CAPILLARY; CELL; OXIDATION; METALLOCENES; DERIVATIVES; MOLECULES C1 Yale Univ, Dept Mech Engn, New Haven, CT 06511 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ New Orleans, Dept Chem, New Orleans, LA 70148 USA. MIT, Dept Aeronaut & Astronaut, Cambridge, MA 02139 USA. Virginia Commonwealth Univ, Dept Chem, Richmond, VA 23284 USA. RP de la Mora, JF (reprint author), Yale Univ, Dept Mech Engn, New Haven, CT 06511 USA. NR 59 TC 168 Z9 172 U1 9 U2 80 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD AUG PY 2000 VL 35 IS 8 BP 939 EP 952 PG 14 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 347MU UT WOS:000088934400002 ER PT J AU Jarausch, KF Kiely, JD Houston, JE Russell, PE AF Jarausch, KF Kiely, JD Houston, JE Russell, PE TI Defect-dependent elasticity: Nanoindentation as a probe of stress state SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MECHANICAL-PROPERTIES; GRAIN-SIZE; NANOCRYSTALLINE MATERIALS; FORCE MICROSCOPY; RESIDUAL-STRESS; COPPER; FILMS; CU; DEFORMATION; INDENTATION AB Using an interfacial force microscope, the measured elastic response of 100-nm-thick Au films was found to be strongly correlated with the films' stress state and thermal history. Large, reversible variations (2x) of indentation modulus were recorded as a function of applied stress. Low-temperature annealing caused permanent changes in the films' measured elastic properties. The measured elastic response was also found to vary in close proximity to grain boundaries in thin films and near surface steps on single-crystal surfaces. These results demonstrate a complex interdependence of stress state, defect structure, and elastic properties in thin metallic films. C1 N Carolina State Univ, Raleigh, NC 27695 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Jarausch, KF (reprint author), Intel Corp, 2200 Mission Coll Blvd, Santa Clara, CA 95052 USA. NR 33 TC 16 Z9 17 U1 2 U2 8 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 AUG PY 2000 VL 15 IS 8 BP 1693 EP 1701 DI 10.1557/JMR.2000.0244 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 341KD UT WOS:000088588800009 ER PT J AU Williams, JJ Kramer, MJ Akinc, M Malik, SK AF Williams, JJ Kramer, MJ Akinc, M Malik, SK TI Effects of interstitial additions on the structure of Ti5Si3 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID TITANIUM SILICIDE; THERMAL-EXPANSION; ANISOTROPY; BEHAVIOR AB Changes in the structure of Ti5Si3 were measured by x-ray and neutron diffraction as carbon, nitrogen, or oxygen atoms were systematically incorporated into the lattice. Additionally, the lattice parameters and variable atomic positions of pure Ti5Si3 were determined to be a = 7.460 Angstrom, c = 5.152 Angstrom, x(Ti) = 0.2509, and x(Si) = 0.6072. The measured trends in lattice parameters as carbon, nitrogen, or oxygen atoms were added to Ti5Si3 showed that most of the previous studies on supposedly pure Ti5Si3 were actually contaminated by these pervasive light elements. Also, oxygen and carbon additions were shown to strongly draw in the surrounding titanium atoms-evidence for bonding between these atoms. The bonding changes that occurred on addition of carbon, nitrogen, or oxygen acted to decrease the measured anisotropic properties of Ti5Si3, such as thermal expansion. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Univ Missouri, Res Reactor, Columbia, MO 65211 USA. RP Williams, JJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 16 TC 16 Z9 16 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 AUG PY 2000 VL 15 IS 8 BP 1773 EP 1779 DI 10.1557/JMR.2000.0256 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 341KD UT WOS:000088588800021 ER PT J AU Williams, JJ Kramer, MJ Akinc, M AF Williams, JJ Kramer, MJ Akinc, M TI Thermal expansion of Ti5Si3 with Ge, B, C, N, or O additions SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID DIFFRACTION; ANISOTROPY AB The crystallographic thermal expansion coefficients of Ti5Si3 from 20 to 1000 degrees C as a function of B, C, N, O, or Ge content were measured by high-temperature x-ray diffraction using synchrotron sources at Cornell University (Cornell High Energy Synchrotron Source; CHESS) and Argonne National Laboratory (Advanced Photon Source; APS). Whereas the ratio of the thermal expansion coefficients along the c and a axes was approximately 3 for pure Ti5Si3, this ratio decreased to about 2 when B, C, or N atoms were added. Additions of O and Ge were less efficient at reducing this thermal expansion anisotropy. The extent by which the thermal expansion was changed when B, C, N, or O atoms were added to Ti5Si3 correlated with their expected effect on bonding In Ti5Si3. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Williams, JJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 15 TC 27 Z9 27 U1 1 U2 2 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 AUG PY 2000 VL 15 IS 8 BP 1780 EP 1785 DI 10.1557/JMR.2000.0257 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 341KD UT WOS:000088588800022 ER PT J AU Larsen, G Lotero, E Marquez, M AF Larsen, G Lotero, E Marquez, M TI Facile sol-gel synthesis of porous silicas using poly(propylene)imine dendrimers as templates SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES; SIZE DISTRIBUTION; PORE-SIZE; ZIRCONIA; TEMPERATURE; PYROLYSIS; CATALYSIS; HYBRID; TIO2 AB Commercially available poly(propylene)imine (DAB-Am-32 and DAB-Am-64) dendrimers were used as single-molecule templates to tailor the porosity of silicas via a nonacidic sol-gel method. X-ray diffraction on both the as-prepared (oven-dried at 373 K) and the calcined (833 K) materials revealed that modest contraction took place on template removal and that the cavities created did not achieve three-dimensional ordering under the current synthesis conditions. Transmission electron microscopy of "Pt-stained" samples supported this picture. A modified Horvath-Kawazoe analysis of the argon adsorption isotherms indicated that DAB-Am-64 is a much more effective template than DAB-Am-32, Pyrolysis and oxidation protocols for template removal are also presented. C1 Univ Nebraska, Dept Chem Engn, Lincoln, NE 68588 USA. Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Kraft Gen Foods Inc, Nanotechnol Lab NanoteK, Res & Dev, Glenview, IL 60025 USA. RP Larsen, G (reprint author), Univ Nebraska, Dept Chem Engn, Lincoln, NE 68588 USA. NR 26 TC 19 Z9 19 U1 1 U2 8 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 AUG PY 2000 VL 15 IS 8 BP 1842 EP 1848 DI 10.1557/JMR.2000.0266 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 341KD UT WOS:000088588800031 ER PT J AU Hoffmann, MM Young, JS Fulton, JL AF Hoffmann, MM Young, JS Fulton, JL TI Unusual dysprosium ceramic nano-fiber growth in a supercritical aqueous solution SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID THROUGH HYDROTHERMAL PROCESS; RAPID EXPANSION; POWDERS; WHISKERS; FILMS AB The formation of nano-size ceramic fibers having diameters as small as 20 nm is described. This material was obtained by a simple precipitation reaction from a supercritical aqueous dysprosium bromide solution at high temperatures (450 degrees C). The nano-structures have unusually high structural stability for extended time periods in this extreme solvent environment. The experimental procedures are described and analysis of the materials by scanning and transition electron microscopy, and x-ray diffraction is presented. The new materials may have useful applications as high-strength, corrosion resistant materials or as stable catalyst supports for extreme conditions. (C) 2000 Kluwer Academic Publishers. C1 Pacific NW Natl Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. RP Fulton, JL (reprint author), Pacific NW Natl Lab, Environm & Hlth Sci Div, POB 999,MS P8-19, Richland, WA 99352 USA. NR 16 TC 6 Z9 7 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD AUG PY 2000 VL 35 IS 16 BP 4177 EP 4183 DI 10.1023/A:1004875413406 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 335DB UT WOS:000088226600030 ER PT J AU Christensen, RM AF Christensen, RM TI A general measure for the ductility of materials - Part II Applications SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Stanford Univ, Stanford, CA 94305 USA. RP Christensen, RM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-355, Livermore, CA 94551 USA. NR 7 TC 1 Z9 1 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 AUG PY 2000 VL 19 IS 16 BP 1465 EP 1468 DI 10.1023/A:1011083725355 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 346ZG UT WOS:000088901300017 ER PT J AU Lytle, CA Gan, YD White, DC AF Lytle, CA Gan, YD White, DC TI Electrospray ionization/mass spectrometry compatible reversed-phase separation of phospholipids: piperidine as a post column modifier for negative ion detection SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE electrospray ionization; phospholipids; phosphatidylglycerol; phospatidylethanolamine; phosphatidylcholine; high-performance liquid chromatography/electrospray ionization/mass spectrometry ID TANDEM MASS-SPECTROMETRY; PERFORMANCE LIQUID-CHROMATOGRAPHY; LIGHT-SCATTERING DETECTION; FAST-ATOM-BOMBARDMENT; BACTERIAL PHOSPHOLIPIDS; QUANTITATIVE-ANALYSIS; MICROBIAL ECOLOGY; FATTY-ACIDS; BIODIVERSITY; SUBSURFACE AB An electrospray ionization (ESI) compatible separation of phospholipids (PL), phosphatidylglycerol (PG), phosphatidyl ethanolamine (PE), and phosphatidylcholine (PC), was performed on a C18 column by reversed phase High Performance Liquid Chromatography (HPLC) with minimal ESI suppression. The mobile phase,used isocratically, consisted of methanol and water. ESI was used to efficiently transfer the ions present in solution to the gas phase for mass spectrometric (MS) detection. Formation of negative ions was reinforced by incorporating piperidine post column. Limits of detection (LOD) and limits of quantitation (LOQ) were experimentally determined to be 20 and 60 fmol/mu l, respectively, when acquiring data in the selected ion monitoring (SIM) mode monitoring three ions with a single quadrupole MS. When acquiring data from m/z 110-900 in the scanning mode, the LOD and LOQ were experimentally determined to be 1 pmol/mu l and 3 pmol/mu l. When acquiring product ion spectra for m/z 747, the LOD and LOQ were experimentally determined to be 446 attomol/mu l and 1.3 fmol/mu l, respectively. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37983 USA. RP White, DC (reprint author), Univ Tennessee, Ctr Environm Biotechnol, 10515 Res Dr,Suite 300, Knoxville, TN 37996 USA. NR 19 TC 30 Z9 30 U1 1 U2 6 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 AUG PY 2000 VL 41 IS 3 BP 227 EP 234 DI 10.1016/S0167-7012(00)00156-1 PG 8 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 351PK UT WOS:000089167200007 PM 10958968 ER PT J AU Hedrick, DB Peacock, A Stephen, JR Macnaughton, SJ Bruggemann, J White, DC AF Hedrick, DB Peacock, A Stephen, JR Macnaughton, SJ Bruggemann, J White, DC TI Measuring soil microbial community diversity using polar lipid fatty acid and denaturing gradient gel electrophoresis data SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE diversity; Shannon's index; Simpson's index; 16s rDNA; denaturing gradient gel electrophoresis; polar lipid fatty acids ID POLYMERASE CHAIN-REACTION; GENETIC DIVERSITY; RIBOSOMAL-RNA; BACTERIA; PCR; DNA; TEMPERATURE; POPULATIONS; SEDIMENTS; PROFILES AB The possibility of calculating useful microbial community diversity indices from environmental polar lipid fatty acid and 16S rDNA PCR-DGGE data was investigated. First, the behavior of the species richness, Shannon's, and Simpson's diversity indices were determined on polar lipid fatty acid profiles of 115 pure cultures, communities constructed from those profiles with different numbers of species, and constructed communities with different distributions of species. Differences in the species richness of these artificial communities was detected by all three diversity indices, but they were insensitive to the evenness of the distribution of species. Second, data from a field experiment with substrate addition to soil was used to compare the methods developed for lipid- and DNA-based diversity indices. Very good agreement was found between indices calculated from environmental polar lipid fatty acid profiles and denaturing gradient gel electrophoresis profiles from matched samples (Pearson's correlation coefficient r=0.95-0.96). A method for data pre-treatment for diversity calculations is described. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Hedrick Serv, Knoxville, TN 37996 USA. Natl Environm Technol Ctr, Culham Sci Ctr E6, Abingdon OX14 3ED, Oxon, England. Hort Res Int, Corp & Weed Sci Dept, Wellesbourne CV35 9EF, Warwick, England. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37851 USA. RP White, DC (reprint author), Univ Tennessee, Ctr Environm Biotechnol, 10515 Res Dr,Ste 300, Knoxville, TN 37932 USA. NR 39 TC 47 Z9 55 U1 1 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 AUG PY 2000 VL 41 IS 3 BP 235 EP 248 DI 10.1016/S0167-7012(00)00157-3 PG 14 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 351PK UT WOS:000089167200008 PM 10958969 ER PT J AU Liu, CP Miller, PD Henstrom, WL Gibson, JM AF Liu, CP Miller, PD Henstrom, WL Gibson, JM TI Transmission electron microscopy of semiconductor quantum dots SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article DE Ge/Si; InAs/GaAs; phase-amplitude diagram; quantum dots; semiconductor heterostructures; shape measurement; size measurement; strain contrast; strain measurement; suppressed-diffraction imaging ID STRESS-RELAXATION; SHAPE TRANSITION; COHERENT ISLANDS; GE; DIFFRACTION; SI(001); STRAIN; CLUSTERS; GROWTH AB We report on plan-view transmission electron microscopy techniques, by which the size, the actual shape and the strain of a coherent quantum dot in semiconductor heterostructures can be measured very accurately. The bright-field suppressed-diffraction imaging condition where no strong diffracted beam is excited in the sample provides reliable size measurement. Using suppressed-diffraction imaging condition, the intensity contour in a coherent island is related to the height, and thus the detailed shape and the aspect ratio can be extracted. The strain contrast of a coherent island imaged using an exact two-beam dynamical diffraction condition is useful for strain measurement and the corresponding features is related to the shape of an island. The physical origins and accuracy of interpretation of the image contrast are discussed, using the simulations and experimental examples. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Argonne Natl Labs, Div Mat Sci, Argonne, IL 60439 USA. RP Liu, CP (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. RI Liu, Chuan-Pu /H-8926-2012; Gibson, Murray/E-5855-2013 OI Gibson, Murray/0000-0002-0807-6224 NR 19 TC 12 Z9 13 U1 1 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD AUG PY 2000 VL 199 BP 130 EP 140 DI 10.1046/j.1365-2818.2000.00729.x PN 2 PG 11 WC Microscopy SC Microscopy GA 345GB UT WOS:000088807300007 ER PT J AU Sever, DM Ryan, TJ Morris, T Patton, D Swafford, S AF Sever, DM Ryan, TJ Morris, T Patton, D Swafford, S TI Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). II. Annual oviducal cycle SO JOURNAL OF MORPHOLOGY LA English DT Article DE reptilia; Serpentes; Seminatrix pygaea; ultrastructure; oviduct ID GARTER SNAKE; NUTRITIONAL PROVISION; THAMNOPHIS-SIRTALIS; HISTOLOGY; REPTILES; PLACENTATION; VIVIPARITY; MORPHOLOGY; EVOLUTION; SERPENTES AB This article is the first ultrastructural study on the annual oviducal cycle in a snake. The ultrastructure of the oviduct was studied in 21 females of the viviparous natricine snake Seminatrix pygaea. Specimens were collected and sacrificed in March, May, June, July, and October from one locale in South Carolina during 1998-1999. The sample included individuals: 1) in an inactive reproductive condition, 2) mated but prior to ovulation, and 3) from early and late periods of gravidity. The oviduct possesses four distinct regions from cranial to caudal: the anterior infundibulum, the posterior infundibulum containing sperm storage tubules (SSTs), the uterus, and the vagina. The epithelium is simple throughout the oviduct and invaginations of the lining form tubular glands in all regions except the anterior infundibulum and the posterior vagina. The tubular glands are not alveolar, as reported in some other snakes, and simply represent a continuation of the oviducal lining with no additional specializations. The anterior infundibulum and vagina show the least amount of variation in relation to season or reproductive condition. In these regions, the epithelium is irregular, varying from squamous to columnar, and cells with elongate cilia alternate with secretory cells. The secretory product of the infundibulum consists largely of lipids, whereas a glycoprotein predominates in the vagina; however, both products are found in these regions and elsewhere in the oviduct. In the SST area and the anterior vagina, tubular glands are compound as well as simple. The epithelium of the SST is most active after mating, and glycoprotein vacuoles and lipid droplets are equally abundant. When present, sperm form tangled masses in the oviducal lumen and glands of the SST area. The glands of the uterus are always simple. During sperm migration, a carrier matrix composed of sloughed epithelial cells, a glycoprotein colloid, lipids, and membranous structures surround sperm in the posterior uterus. During gravidity, tubular glands, cilia, and secretory products diminish with increasing development of the fetus, and numerous capillaries abut the basal lamina of the attenuated epithelial lining of the uterus. (C) 2000 Wiley-Liss, Inc. C1 St Marys Coll, Dept Biol, Notre Dame, IN 46556 USA. Univ Missouri, Div Biol Sci, Columbia, MO 65211 USA. Savannah River Ecol Lab, Aiken, SC USA. RP Sever, DM (reprint author), St Marys Coll, Dept Biol, Notre Dame, IN 46556 USA. NR 27 TC 23 Z9 24 U1 1 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0362-2525 J9 J MORPHOL JI J. Morphol. PD AUG PY 2000 VL 245 IS 2 BP 146 EP 160 DI 10.1002/1097-4687(200008)245:2<146::AID-JMOR5>3.3.CO;2-6 PG 15 WC Anatomy & Morphology SC Anatomy & Morphology GA 340DW UT WOS:000088518700005 PM 10906748 ER PT J AU Hashimoto, N Wakai, E Robertson, JP Sawai, T Hishinuma, A AF Hashimoto, N Wakai, E Robertson, JP Sawai, T Hishinuma, A TI Microstructure of austenitic stainless steels irradiated at 400 degrees C in the ORR and the HFIR spectral tailoring experiment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID EVOLUTION AB Microstructural evolution in solution-annealed Japanese-PCA (JPCA-SPI) and four other austenitic stainless steels, irradiated at 400 degrees C to 17.3 dpa in the ORR and the high flux isotope reactor (HFIR) spectrally tailored experiment, were investigated by transmission electron microscopy (TEM). The mean He/dpa ratio throughout the irradiation fell between 12 and 16 appm He/dpa, which is close to the He/dpa values expected for fusion. In all the specimens, a bimodal size distribution of cavities was observed and the number densities were about 1.0 x 10(22) m(-3). There was no significant difference between the number densities in the different alloys, although the root mean cubes of the cavity radius are quite different for each alloy. Precipitates of the MC type were also observed in the matrix and on grain boundaries in all alloys except a high-purity (HP) ternary alloy. The JPCA-SA (including 0.06% carbon and 0.027% phosphorus) and standard type 316 steel (including 0.06% carbon and 0.028% phosphorus) showed quite low-swelling values of about 0.016 and 0.015%, respectively, while a HP ternary austenitic alloy showed the highest swelling value of 2.9%. This suggests that the existence of impurities affects the cavity growth in austenitic stainless steels even at 400 degrees C. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. RP Hashimoto, N (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Bldg 5500 MS 6376,POB 2008, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012; Wakai, Eiichi/L-1099-2016 NR 16 TC 7 Z9 7 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG PY 2000 VL 280 IS 2 BP 186 EP 195 DI 10.1016/S0022-3115(00)00046-5 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 334ZE UT WOS:000088216100006 ER PT J AU Abraitis, PK McGrail, BP Trivedi, DP Livens, FR Vaughan, DJ AF Abraitis, PK McGrail, BP Trivedi, DP Livens, FR Vaughan, DJ TI Single-pass flow-through experiments on a simulated waste glass in alkaline media at 40 degrees C. I. Experiments conducted at variable solution flow rate to glass surface area ratio SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID SOLUTION SATURATION STATE; R7T7 NUCLEAR GLASS; PRECIPITATION KINETICS; BOROSILICATE GLASS; DISSOLUTION RATE; BASALTIC GLASS; SILICA; TERM; PH; 90-DEGREES-C AB Dissolution of a borosilicate glass containing a complex mixture of simulated fission product oxides has been investigated in single-pass flow-through (SPFT) experiments in moderately alkaline media at 40 degrees C. The experiments were designed such that the ratio of the solution flow rate to the glass surface area varied extensively over the experimental matrix. Dissolution of the glass is surface reaction-controlled under these experimental conditions. In Si-rich, alkaline solutions, the concentration of Al is moderated to very low levels by the development of secondary aluminosilicate gels. Rates of dissolution decrease linearly as the solution activity product a(Al(OH)4)(-) (0.06)((nq))a(H4SiO4)(0.51) increases. A rate law containing a mixed Al/Si affinity term gives good agreement with the experimental data. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Manchester, Dept Earth Sci, Manchester M13 9PL, Lancs, England. Pacific NW Lab, Appl Geol & Geochem Dept, Richland, WA 99352 USA. British Nucl Fuels PLC, Environm Assessments, Warrington WA3 6AS, Cheshire, England. Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England. RP Abraitis, PK (reprint author), Univ Manchester, Dept Earth Sci, Williamson Bldg,Oxford Rd, Manchester M13 9PL, Lancs, England. NR 25 TC 28 Z9 28 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG PY 2000 VL 280 IS 2 BP 196 EP 205 DI 10.1016/S0022-3115(00)00041-6 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 334ZE UT WOS:000088216100007 ER PT J AU Abraitis, PK McGrail, BP Trivedi, DP Livens, FR Vaughan, DJ AF Abraitis, PK McGrail, BP Trivedi, DP Livens, FR Vaughan, DJ TI Single-pass flow-through experiments on a simulated waste glass in alkaline media at 40 degrees C. II. Experiments conducted with buffer solutions containing controlled quantities of Si and Al SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID BOROSILICATE GLASS; AMORPHOUS SILICA; DISSOLUTION; PARAMETERS; CORROSION; ALUMINUM; KINETICS; WATER AB Additional single-pass how-through (SPFT) experiments have been conducted with a complex, simulated waste glass at 40 degrees C in moderately alkaline media. Results are compared to those obtained in the experiments described in Part I, and with published data obtained in long-term, static, batch dissolution experiments with this glass formulation. Dissolution rate laws for the glass must account for the rate influencing effects of both dissolved Si and Al species. These experiments have shown that on a mole per mole basis, dissolved Al has a more significant influence on the glass dissolution rate than dissolved Si under these experimental conditions. The very low 'long-term' dissolution rates reported in static batch dissolution experiments reflect near saturation conditions that are not attained in SPFT tests as a result of solution flow-through. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Manchester, Dept Earth Sci, Manchester M13 9PL, Lancs, England. Pacific NW Lab, Dept Appl Geol & Geochem, Richland, WA 99352 USA. British Nucl Fuels PLC, Environm Assessments, Warrington WA3 6AS, Cheshire, England. Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England. RP Abraitis, PK (reprint author), Univ Manchester, Dept Earth Sci, Williamson Bldg,Oxford Rd, Manchester M13 9PL, Lancs, England. NR 16 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG PY 2000 VL 280 IS 2 BP 206 EP 215 DI 10.1016/S0022-3115(00)00040-4 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 334ZE UT WOS:000088216100008 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Franceschi, D Logan, J Pappas, NR Wong, CT Netusil, N AF Wang, GJ Volkow, ND Fowler, JS Franceschi, D Logan, J Pappas, NR Wong, CT Netusil, N TI PET studies of the effects of aerobic exercise on human striatal dopamine release SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE [C-11]raclopride; aerobic exercise; PET; dopamine release ID C-11 RACLOPRIDE BINDING; HUMAN BRAIN; EXTRACELLULAR DOPAMINE; NUCLEUS-ACCUMBENS; RAT STRIATUM; BLOOD-FLOW; AMPHETAMINE; COCAINE; METHYLPHENIDATE; MICRODIALYSIS AB In vivo microdialysis studies have shown that exercise increases the concentration of dopamine (DA) in the striatum of the rat brain. it has also been shown that PET with [C-11]raclopride can be used to assess changes in brain DA induced by drugs and by performance tasks such as playing a video game. The purpose of this study was to evaluate the effects of exercise (treadmill running) on striatal DA release in the human brain. Methods: Twelve healthy volunteers (5 women, 7 men; mean age, 32 +/- 5 y; age range, 25-40 y) with a history of regular exercise received 2 PET scans with [C-11]raclopride on 2 separate days, 1 at baseline and 1 at 5-10 min after running on a treadmill for 30 min. The speed and inclination of the treadmill were increased gradually to reach a maximal speed of 9.7 km/h (6 mph) and a maximal inclination of 10 degrees. Data were acquired on a Siemens HR+ scanner in 3-dimensional mode for 60 min. Heart rates and electrocardiograms were monitored. DA D-2 receptor availability was measured using the ratio of the distribution Volume in the putamen to that in the cerebellum, which is a function of the number of available binding sites/dissociation constant. Results: The subjects ran at an average speed of 8.7 +/- 0.5 km/h (5.4 +/- 0.3 mph) and at an inclination of 3.3 degrees +/- 2 degrees. The maximum effort of running was maintained for 10-15 min. The heart rates of the subjects were increased by 143% +/- 47%. DA Dg receptor availability in the putamen after treadmill running (4.22 +/- 0.34) was no different from that of baseline (4.17 +/- 0.29; P < 0.6). Conclusion: No significant changes in synaptic DA concentration were detected, although the subjects exercised vigorously for 30 min. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Radiol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. RP Wang, GJ (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. FU NIDA NIH HHS [DA 06891-02] NR 37 TC 62 Z9 65 U1 4 U2 15 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 AUG PY 2000 VL 41 IS 8 BP 1352 EP 1356 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 364JG UT WOS:000089888800018 PM 10945526 ER PT J AU White, AG Lam, PK McClelland, DE Bachor, HA Munro, WJ AF White, AG Lam, PK McClelland, DE Bachor, HA Munro, WJ TI Kerr noise reduction and squeezing SO JOURNAL OF OPTICS B-QUANTUM AND SEMICLASSICAL OPTICS LA English DT Article DE quantum optics; squeezing; noise reduction; Ken effect; second harmonic generation (SHG) ID 2ND-HARMONIC GENERATION; OPTICAL BISTABILITY; STATE GENERATION; QUANTUM OPTICS; LASER-DIODES; COLD ATOMS; LIGHT; SYSTEM; CAVITY; NONLINEARITIES AB We introduce a model of squeezing and noise reduction in the Ken effect that accounts for noise in all quadratures of the driving field. Consequently we show that Ken squeezing is much more sensitive to driving noise than squeezing produced by second harmonic generation (SHG). We experimentally demonstrate this sensitivity using a nonlinear system that tunes between strong classical SHG and Ken behaviours. Whilst the system experiences strong squeezing in the SHG limit, it experiences no squeezing in the Ken limit, although it does experience strong classical noise reduction, or 'classical squeezing'. C1 Univ Queensland, Dept Phys, Brisbane, Qld 4072, Australia. Australian Natl Univ, Dept Phys, Canberra, ACT 0200, Australia. Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP White, AG (reprint author), Univ Queensland, Dept Phys, Brisbane, Qld 4072, Australia. RI Lam, Ping Koy/A-5276-2008; McClelland, David/E-6765-2010; White, Andrew/A-1088-2009; Munro, William/A-8453-2011; OI Lam, Ping Koy/0000-0002-4421-601X; McClelland, David/0000-0001-6210-5842; White, Andrew/0000-0001-9639-5200; Munro, William/0000-0003-1835-2250; Bachor, Hans/0000-0001-8866-9486 NR 37 TC 10 Z9 10 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1464-4266 J9 J OPT B-QUANTUM S O JI J. Opt. B-Quantum Semicl. Opt. PD AUG PY 2000 VL 2 IS 4 BP 553 EP 561 DI 10.1088/1464-4266/2/4/315 PG 9 WC Optics; Physics, Applied SC Optics; Physics GA 364TM UT WOS:000089909100018 ER PT J AU Grimes, RW Chen, SP AF Grimes, RW Chen, SP TI The influence of ion size on the binding of a charge compensating cobalt vacancy to M3+ dopant ions in CoO SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE oxides; ceramics; defects; cobalt oxide ID DEFECT STRUCTURE; ELECTRICAL-PROPERTIES; TRACER DIFFUSION; DOPED COO; OXIDE AB Atomistic simulation calculations are used to predict the lowest energy defect cluster geometries for M3+ dopant cations adjacent to a cobalt vacancy in CoO. Both simple dimers (one dopant ion and one vacancy) and trimers (two dopant ions and one vacancy) are considered. The results suggest that small radius dopant ions prefer a cluster geometry in which they are in a second cation neighbour position with respect to a vacant cobalt site whereas large radius ions prefer a first cation neighbour position. As a consequence of this changing geometry preference, the binding energies associated with small and large dopant cations (e.g. Al and La) are larger than those associated with intermediate sized ions (e.g. Fe and Sc). (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Grimes, RW (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. NR 28 TC 10 Z9 10 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG PY 2000 VL 61 IS 8 BP 1263 EP 1268 DI 10.1016/S0022-3697(99)00408-4 PG 6 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 324NX UT WOS:000087629200010 ER PT J AU Bruls, RJ Hintzen, HT Metselaar, R Loong, CK AF Bruls, RJ Hintzen, HT Metselaar, R Loong, CK TI Anisotropic thermal expansion of MgSiN2 from 10 to 300 K as measured by neutron diffraction SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE ceramics; neutron diffraction; crystal structure; thermal expansion ID CRYSTAL-STRUCTURES; POWDERS; SILICON AB The lattice parameters of orthorhombic MgSiN2 as a function of the temperature have been determined from time-of-flight neutron powder diffraction. The results indicate that MgSiN2, just like several other adamantine-type crystals, exhibits a relatively small thermal expansion coefficient at low temperatures. This is ascribed to a strongly bonded 3D, relatively open, crystal structure which is characteristic of highly covalent bonded materials. The anisotropic linear thermal expansion behaviour could be qualitatively related to the characteristics of the crystal structure. The least dense packed crystallographic direction showed the smallest anisotropic linear expansion coefficient. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Eindhoven Univ Technol, Lab Solid State & Mat Chem, NL-5600 MB Eindhoven, Netherlands. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Bruls, RJ (reprint author), Eindhoven Univ Technol, Lab Solid State & Mat Chem, POB 513, NL-5600 MB Eindhoven, Netherlands. NR 32 TC 22 Z9 22 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG PY 2000 VL 61 IS 8 BP 1285 EP 1293 DI 10.1016/S0022-3697(99)00416-3 PG 9 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 324NX UT WOS:000087629200013 ER PT J AU Heitner, KL AF Heitner, KL TI The search for the better polymer electrolyte SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND C1 US DOE, Washington, DC 20585 USA. RP Heitner, KL (reprint author), US DOE, Washington, DC 20585 USA. NR 15 TC 24 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD AUG PY 2000 VL 89 IS 2 BP 128 EP 131 DI 10.1016/S0378-7753(00)00419-5 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100002 ER PT J AU Thomas, KE Sloop, SE Kerr, JB Newman, J AF Thomas, KE Sloop, SE Kerr, JB Newman, J TI Comparison of lithium-polymer cell performance with unity and nonunity transference numbers SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE lithium-polymer cell; unity transference numbers; nonunity transference numbers AB This work compares the performance of lithium batteries with polymer electrolytes with unity ("ionomer'') and nonunity ("polymer electrolyte") transference numbers. The study is performed with respect to a particular cell chemistry, Li metal \ polymer \ LiV6O13- composite electrode, which is currently a top candidate for use in electric vehicles. Cell performance was modeled to determine the best possible performance of cells containing four different electrolytes: "ideal'' polymer membrane and ionomer with properties defined by USABC goals, and the presently best available polymer electrolyte and ionomer. Positive electrode thickness, porosity, and current density were varied to find the cell geometry with the highest combined energy density and peak power performance for cells with each electrolyte, and concentration and potential profiles are examined to determine the limitations of the electrolytes. The results show that at 40 degrees C, the "ideal" polymer electrolyte can provide 104 W h/kg and 99 W-p/kg, the "ideal" ionomer can provide 94 W h/kg and 58 W-p/kg, and the currently available electrolytes can provide about one-fifth of these values. Published by Elsevier Science S.A. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Newman, J (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Newman, John/B-8650-2008 OI Newman, John/0000-0002-9267-4525 NR 11 TC 79 Z9 80 U1 2 U2 30 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 AUG PY 2000 VL 89 IS 2 BP 132 EP 138 DI 10.1016/S0378-7753(00)00420-1 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100003 ER PT J AU Zhuang, GR Ross, PN AF Zhuang, GR Ross, PN TI Contrasting film formation reactions of ethereal and carbonate solvents on metallic lithium SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE ethereal; carbonate; lithium ID PROPYLENE CARBONATE; PHOTOEMISSION SPECTROSCOPY; TETRAHYDROFURAN; DEPOSITION; ELECTRODE; LI AB A summary of studies by photoelectron spectroscopy of the reactions of prototypical ethereal and alkyl carbonate solvents with lithium metal in ultra-high vacuum (UHV) is presented. The Li/solvent interface is formed by condensing solvent vapor onto the surface of freshly vacuum evaporated Li at 130 K. The reaction is observed by obtaining core-level photoelectron spectra as a function of temperature. The interfacial reactions are distinctly different for the ethereal vs. the carbonate solvents. The ethers, both cyclic (THF and 1,3-dioxolane) and linear (glymes), react initially to form an LiOR or radical anion (1,3-dioxolane) precursor, followed by the formation of a polyether layer. In the carbonates, there is a significant difference between linear and cyclical forms. The linear carbonates (DMC and DEC) are more reactive, reacting even below the melting point, and produce both LiOCO2R and LiR (alkyl lithium). There are no unreacted solvent molecules left on the surface at room temperature. Since alkyl lithium is soluble in the bulk solvent, the lithium surface will not passivate in this solvent until considerable dissolution of lithium has occurred. The cyclic carbonate PC forms only insoluble LiOCO2R, but no unreacted PC (or PC-like molecule) remains at room temperature. Thus, the corrosion of lithium in DMC/DEC is predicted to be significantly greater than in PC. Since the ethers incorporate a significant amount of solvent molecule in the passive layer, e.g. by polymerization, the SEI layer formed in the ethers is predicted to be more highly conducting than in the carbonates. This prediction is based on the chemistry of the pure solvent molecules, absent real life impurities, e.g. water, or an anion, which may react preferentially with lithium. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Ross, PN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 16 TC 8 Z9 8 U1 1 U2 12 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 AUG PY 2000 VL 89 IS 2 BP 143 EP 148 DI 10.1016/S0378-7753(00)00422-5 PG 6 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100005 ER PT J AU Buriez, O Han, YB Hou, J Kerr, JB Qiao, J Sloop, SE Tian, MM Wang, SG AF Buriez, O Han, YB Hou, J Kerr, JB Qiao, J Sloop, SE Tian, MM Wang, SG TI Performance limitations of polymer electrolytes based on ethylene oxide polymers SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE performance limitations; polymer electrolytes; ethylene oxide polymers ID SIDE-CHAIN LENGTH; CROSS-LINKING; SALT MIXTURES; CONDUCTIVITY; LITHIUM; POLYPHOSPHAZENES; ETHER; CELLS AB Studies of polymer electrolyte solutions for lithium-polymer batteries are described. Two different salts, lithium bis(trifluoromethane-sulfonyl)imide (LiTFSI) and lithium trifluoromethanesulfonate (LiTf), were dissolved in a variety of polymers. The structures were all based upon the ethylene oxide unit for lithium ion solvation, and both linear and comb-branch polymer architectures have been examined. Conductivity, salt diffusion coefficient and transference number measurements demonstrate the superior transport properties of the LiTFSI salt over LiTf. Data obtained on all of these polymers combined with LiTFSI salts suggest that there is a limit to the conductivity achievable at room temperature, at least for hosts containing ethylene oxide units. The apparent conductivity limit is 5 X 10(-5) S/cm at 25 degrees C. Providing that the polymer chain segment containing the ethylene oxide units is at least 5-6 units long, there appears to be little influence of the polymer framework to which the solvating groups are attached. To provide adequate separator function, the mechanical properties may be disconnected from the transport properties by selection of an appropriate architecture combined with an adequately long ethylene oxide chain. For both bulk and interfacial, transport of the lithium ions, conductivity data alone is insufficient to understand the processes that occur. Lithium ion transference numbers and salt diffusion coefficients also play a major role in the observed behavior and the transport properties of these polymer electrolyte solutions appear to be quite inadequate for ambient temperature performance. At present, this restricts the use of such systems to high temperature applications. Several suggestions are given to overcome these obstacles. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kerr, JB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 62-203,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 31 TC 43 Z9 43 U1 1 U2 23 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 AUG PY 2000 VL 89 IS 2 BP 149 EP 155 DI 10.1016/S0378-7753(00)00423-7 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100006 ER PT J AU McBreen, J Lee, HS Yang, XQ Sun, X AF McBreen, J Lee, HS Yang, XQ Sun, X TI New approaches to the design of polymer and liquid electrolytes for lithium batteries SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE polymer; liquid electrolytes; lithium batteries ID ION-PAIR DISSOCIATION; X-RAY-ABSORPTION; POLY(ETHYLENE OXIDE); ANION RECEPTORS; TEMPERATURE-DEPENDENCE; NONAQUEOUS SOLUTIONS; POTASSIUM-SALT; CONDUCTIVITY; COMPLEXES; NACF3SO3 AB All non-aqueous lithium battery electrolytes are Lewis bases that interact with cations. Unlike water, they do not interact with anions. The result is a high degree of ion pairing and the formation of triplets and higher aggregates. This decreases the conductivity and the lithium ion transference, and results in polarization losses in batteries. Approaches that have been used to increase ion dissociation in poly(ethylene oxide) (PEO)-based electrolytes are the use of salts with low lattice energy, the addition of polar plasticizers to the polymer, and the addition of cation complexing agents such as crown ethers or cryptands. Complexing of the anions is a more promising approach, since it should increase both ion dissociation and the lithium transference. At Brookhaven National Laboratory (BNL) we have synthesized two new families of neutral anion complexing agents, each based on Lewis acid centers. One is based on electron deficient nitrogen sites on substituted aza-ethers, wherein the hydrogen on the nitrogen is replaced by electron withdrawing groups such as CF3SO3-. The other is based on electron deficient boron sites on borane or berate compounds with various fluorinated aryl or alkyl groups. Some of the borane-based anion receptors can promote the dissolution of LiF in several solvents. Several of these compounds, when added in equivalent amounts, produce 1.2 M LiF solutions in DME, an increase in solubility of LiF by six orders of magnitude. Some of these LiF electrolytes have conductivities as high as 6 X 10(-3) S cm(-1),The LiF electrolytes with borane anion accepters in PC:EC:DEC solvents have excellent electrochemical stability. This has been demonstrated in small Li/LiMn2O4 cells. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Mat & Chem Sci, Upton, NY 11973 USA. RP McBreen, J (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Mat & Chem Sci, Upton, NY 11973 USA. NR 27 TC 70 Z9 77 U1 3 U2 42 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 AUG PY 2000 VL 89 IS 2 BP 163 EP 167 DI 10.1016/S0378-7753(00)00425-0 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100008 ER PT J AU Dudney, NJ AF Dudney, NJ TI Addition of a thin-film inorganic solid electrolyte (Lipon) as a protective film in lithium batteries with a liquid electrolyte SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE lipon; lithium batteries; liquid electrolyte ID STATE AB Three rechargeable lithium cells have been fabricated using thin films of Li and sputter-deposited LixMn2-yO4 as the electrodes, and a LiPF6 organic Liquid electrolyte. Cells were cycled up to 18 times between 4.5 and 7.5 V at 25 degrees C both with and without the addition of the thin-film lithium phosphorus oxynitride solid electrolyte, known as Lipon. Of the cells tested, the Lipon film was most effective in maximizing the capacity and cycling efficiency when deposited in direct contact with the cathode; however, a significant improvement over the Lipon-free cell was also observed with Lipon sandwiched between layers of the liquid electrolyte. In the latter case, the Lipon was deposited onto a microporous polypropylene separator membrane. Published by Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Dudney, NJ (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Dudney, Nancy/I-6361-2016 OI Dudney, Nancy/0000-0001-7729-6178 NR 6 TC 67 Z9 70 U1 12 U2 66 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 AUG PY 2000 VL 89 IS 2 BP 176 EP 179 DI 10.1016/S0378-7753(00)00427-4 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100010 ER PT J AU Kong, FP McLarnon, F AF Kong, FP McLarnon, F TI Spectroscopic ellipsometry of lithium/polymer electrolyte interfaces SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE spectroscopic; ellipsometric; lithium/polymer ID LITHIUM ELECTRODES; IN-SITU; FILMS; IDENTIFICATION; BEHAVIOR; SURFACES; SYSTEMS AB Conventional electrochemical techniques and a fast-scan, self-compensating spectroscopic ellipsometer were used to characterize Li/polymer electrolyte interfaces. An electrochemical-ellipsometric test cell employed a grid counter-electrode to allow illumination of the Li/polymer interface, along with a Li-ring reference electrode, which was co-planar with the Li working electrode. Open-circuit cell potentials, current responses to small potential steps, AC impedance data and in situ ellipsometric spectra were recorded after cell assembly and during cell cycle tests, and the optical properties of bare Li metal and candidate reaction products were measured. The ellipsometric spectra of Li/PEO-LiN(CF3SO2)(2) interfaces were interpreted and were consistent with a compact interfacial structure. The as-formed (before current passage) Li/PEO-LiN(CF3SO2)(2) interfacial layer was similar to 12-nm thick and contained mostly Li and Li2O, with > 60 vol.% Li. After a single-cell discharge of 0.4 mA h/cm(2), the interfacial layer became thicker (37 nm) and accumulated > 60 vol. % Li2O. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP McLarnon, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 24 TC 8 Z9 8 U1 4 U2 14 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 AUG PY 2000 VL 89 IS 2 BP 180 EP 189 DI 10.1016/S0378-7753(00)00428-6 PG 10 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100011 ER PT J AU Marmorstein, D Yu, TH Striebel, KA McLarnon, FR Hou, J Cairns, EJ AF Marmorstein, D Yu, TH Striebel, KA McLarnon, FR Hou, J Cairns, EJ TI Electrochemical performance of lithium/sulfur cells with three different polymer electrolytes SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE rechargeable lithium batteries; lithium; sulfur; polysulfide; capacity fade; charge/discharge ID SULFUR BATTERY; REDUCTION; POLYSULFIDES AB Charge and discharge characteristics of lithium/polymer electrolyte/sulfur cells are presented. Three different electrolytes were studied, and cells were operated at temperatures ranging from ambient to about 100 degrees C. The effects of the sulfur electrode composition and cycling regimen on both the potential profiles and the capacity fade rate were investigated. Cells prepared with poly(ethylene oxide) (PEO) and operated at 90-100 degrees C could be discharged to nearly the full theoretical 1672 mA h/g active material but with a high rate of capacity fade. Reducing the depth of discharge to 30% or less increased the cell lifetime. Room-temperature cells with poly(ethylene glycol) dimethyl ether could be discharged to about 45% utilization of the sulfur and showed a much lower capacity fade rate after the second cycle. Several possible explanations for the high rate of capacity fade and the effect of the depth of discharge on this rate are presented. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Cairns, EJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 14 TC 306 Z9 325 U1 20 U2 267 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 AUG PY 2000 VL 89 IS 2 BP 219 EP 226 DI 10.1016/S0378-7753(00)00432-8 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100015 ER PT J AU Doeff, MM Edman, L Sloop, SE Kerr, J De Jonghe, LC AF Doeff, MM Edman, L Sloop, SE Kerr, J De Jonghe, LC TI Transport properties of binary salt polymer electrolytes SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MD DE transport properties; binary salt; polymer ID SYSTEM AB Transport properties (ionic conductivities (sigma), salt diffusion coefficients (D(s)), and cationic transference numbers (t(+)(0))) as a function of salt concentration (C(s)) are reported and compared for several common binary salt/polymer systems being considered for use as electrolytes in rechargeable lithium batteries for electric vehicle and other applications. The three properties provide a complete description of transport in solid polymer electrolytes (SPEs) or "dry" systems in cells undergoing galvanostatic charge and discharge. The macroscopic approach used obviates the need to know the details of speciation in these non-ideal solutions and allows for a more sophisticated correlation of the characteristics of ion transport with polymer structure, salt type, and concentration than conductivity data alone. Published by Elsevier Science S.A. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Umea Univ, Dept Phys, SE-90187 Umea, Sweden. RP Doeff, MM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM doeff@csa2.lbl.gov OI Doeff, Marca/0000-0002-2148-8047 NR 13 TC 44 Z9 44 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD AUG PY 2000 VL 89 IS 2 BP 227 EP 231 DI 10.1016/S0378-7753(00)00433-X PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100016 ER PT J AU Gerald, RE Klingler, RJ Sandi, G Johnson, CS Scanlon, LG Rathke, JW AF Gerald, RE Klingler, RJ Sandi, G Johnson, CS Scanlon, LG Rathke, JW TI Li-7 NMR study of intercalated lithium in curved carbon lattices SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE Li-7 NMR study; intercalated lithium; curved carbon lattices; coin cell battery ID CHARGE-DISCHARGE CHARACTERISTICS; DISORDERED CARBONS; ION CELLS; INSERTION; ANODE; BATTERIES; GRAPHITE; SPECTROSCOPY; ELECTRODES; FIBERS AB A device was invented that permits nuclear magnetic resonance (NMR) analysis of the internal elements of a coin cell battery. The Coin Cell Battery Imager was used to record wideline Li-7 NMR spectra of the lithium ions that were electrochemically intercalated into three different types of carbon-based materials. The samples included graphite, corannulene, and carbon derived from sepiolite clay. All samples were excised from 2032-size coin cells that were cycled multiple times and left in a discharged state (i.e., fully Lithiated), A comparison of the Li-7 NMR spectra recorded for the three carbons revealed that the curved carbon lattice derived from sepiolite affected the lithium resonances in a manner similar to that observed for the curved molecule corannulene, while both differed from the flat lattice of graphite. In addition, it was possible to observe lithium dendrites on the surface of a hard carbon electrode even in the presence of a large lithium counter electrode using NMR imaging techniques. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. USAF, Res Lab, Battery Branch, Wright Patterson AFB, OH 45433 USA. RP Klingler, RJ (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 46 TC 54 Z9 55 U1 8 U2 46 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 AUG PY 2000 VL 89 IS 2 BP 237 EP 243 DI 10.1016/S0378-7753(00)00435-3 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100018 ER PT J AU Duong, TQ AF Duong, TQ TI USABC and PNGV test procedures SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND C1 US DOE, Off Transportat Technol, Washington, DC 20585 USA. RP Duong, TQ (reprint author), US DOE, Off Transportat Technol, 1000 Independence Ave SW, Washington, DC 20585 USA. NR 0 TC 13 Z9 13 U1 0 U2 5 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 AUG PY 2000 VL 89 IS 2 BP 244 EP 248 DI 10.1016/S0378-7753(00)00439-0 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100019 ER PT J AU Dees, DW Battaglia, VS Redey, L Henriksen, GL Atanasoski, R Belanger, A AF Dees, DW Battaglia, VS Redey, L Henriksen, GL Atanasoski, R Belanger, A TI Toward standardizing the measurement of electrochemical properties of solid-state electrolytes in lithium batteries SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Solid State Lithium Battery Workshop CY JUL, 1999 CL TOWSON, MARYLAND DE lithium; battery; electrolyte; solid-state; transport; properties ID TRANSPORT-PROPERTIES; POLYMER AB A brief discussion on transport measurements for lithium ion conducting polymer electrolytes is given. An engineering approach to obtain a complete set of transport and thermodynamic properties for a binary salt dissolved in a polymer electrolyte solvent is described. The technique is based on concentrated solution theory and requires a minimal amount of experimentation. Results from measurements on a representative polymer electrolyte system are given. The measured transport and thermodynamic properties of the polymer electrolyte are used to simulate the performance of symmetric Li/polymer/Li cells and compare to experimental data. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Electrochem Technol Program, Div Chem Technol, Argonne, IL 60439 USA. 3M Co, St Paul, MN 55133 USA. Inst Rech Hydro Quebec, IREQ, Varennes, PQ J3X 1S1, Canada. RP Dees, DW (reprint author), Argonne Natl Lab, Electrochem Technol Program, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 16 TC 10 Z9 10 U1 2 U2 17 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 AUG PY 2000 VL 89 IS 2 BP 249 EP 255 DI 10.1016/S0378-7753(00)00440-7 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 329ZJ UT WOS:000087938100020 ER PT J AU Weaver, DS Ziada, S Ay-Yang, MK Chen, SS Paidoussis, MP Pettigrew, MJ AF Weaver, DS Ziada, S Ay-Yang, MK Chen, SS Paidoussis, MP Pettigrew, MJ TI Flow-induced vibrations in power and process plant components - Progress and prospects SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID EXCHANGER TUBE BUNDLES; CONVEYING VISCOUS-FLUID; CROSS-FLOW; FLUIDELASTIC INSTABILITY; CYLINDRICAL-SHELLS; ACOUSTIC-RESONANCE; STABILITY; MODEL; DYNAMICS; CYLINDER AB This paper provides a brief overview of progress in our understanding of flow-induced vibration in power and process plant components. The flow excitation mechanisms considered are turbulence, vorticity shedding, fluidelastic instability, axial flows, and two-phase flows. Numerous references are provided along with suggestions for future research on unresolved issues. [S0094-9930(00)01203-8]. C1 McMaster Univ, Dept Mech Engn, Hamilton, ON L8S 4L7, Canada. Framatome Technol, Lynchburg, VA 24503 USA. Argonne Natl Lab, Argonne, IL 60439 USA. McGill Univ, Dept Mech Engn, Montreal, PQ H3A 2K6, Canada. AECL Res, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. RP Weaver, DS (reprint author), McMaster Univ, Dept Mech Engn, Hamilton, ON L8S 4L7, Canada. NR 75 TC 56 Z9 62 U1 2 U2 17 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD AUG PY 2000 VL 122 IS 3 BP 339 EP 348 DI 10.1115/1.556190 PG 10 WC Engineering, Mechanical SC Engineering GA 404PX UT WOS:000167110500016 ER PT J AU Viallet, PM Vo-Dinh, T Ribou, AC Vigo, J Salmon, JM AF Viallet, PM Vo-Dinh, T Ribou, AC Vigo, J Salmon, JM TI Native fluorescence and Mag-indo-1-protein interaction as tools for probing unfolding and refolding sequences of the bovine serum albumin subdomain in the presence of guanidine hydrochloride SO JOURNAL OF PROTEIN CHEMISTRY LA English DT Article DE fluorescence spectra; fluorescence quenching; energy transfer; protein folding; conformational changes; structural biology; tryptophan ID SODIUM DODECYL-SULFATE; CYTOSOLIC FREE MAGNESIUM; CONFORMATIONAL-CHANGES; SURFACTANT SOLUTIONS; TRYPTOPHAN RESIDUES; ALKALINE PH; BINDING; PROTEIN; ACID; VISCOSITY AB Changes in the fluorescence spectrum of tryptophans Trp 134 and Trp 212 in bovine serum albumin (BSA) and of Trp 214 of human serum albumin in the presence of the chaotropic agent guanidine hydrochloride (Gnd) were studied. A detailed analysis of the fluorescence spectrum of native BSA yielded the fluorescence spectrum for each tryptophan of BSA. Modifications in the binding of Mag-indo-1 to BSA, which results in a specific quenching of the fluorescence spectrum of Trp 134 associated with an energy transfer from Trp 134 to the protein-bound Mag-indo-1, were also investigated. Changes occurring when the Gnd concentration is decreased stepwise cover a larger concentration scale of Gnd than the reverse protocol, allowing one to suggest that the resulting conformational changes in the subdomain IA of BSA involve at least three different steps. C1 Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, Oak Ridge, TN 37831 USA. Univ Perpignan, Lab Physicochem Biol Integrated Syst, F-66840 Perpignan, France. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, Oak Ridge, TN 37831 USA. NR 46 TC 22 Z9 23 U1 1 U2 7 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0277-8033 J9 J PROTEIN CHEM JI J. Protein Chem. PD AUG PY 2000 VL 19 IS 6 BP 431 EP 439 DI 10.1023/A:1026589012724 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 385PB UT WOS:000166011900002 PM 11195967 ER PT J AU Simmons, KH Mihalas, D AF Simmons, KH Mihalas, D TI A linearized analysis of the modified P-1 equations SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE time-dependent radiation transport; linear radiation waves; P1/3 approximation AB We analyze the propagation of linear radiation waves using the P-1/3 equations recently suggested by Olson (Olson et al. JQSRT 1999; in press). These equations lead to the correct behavior of the radiation held under a wide variety of conditions and may provide a simple and practical method of solving time-dependent radiation transport problems, even in complex geometries. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Simmons, KH (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 9 Z9 9 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD AUG 1 PY 2000 VL 66 IS 3 BP 263 EP 269 DI 10.1016/S0022-4073(99)00149-1 PG 7 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 310LX UT WOS:000086830600004 ER PT J AU Silver, GL AF Silver, GL TI Proportional equations in plutonium chemistry SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB Modem software has made the method of proportional equations easy to use. The method quickly yields oxidation state distributions for plutonium in aqueous solutions, so it serves as a check on the results obtained by other techniques. It is a versatile tool that incorporates mass and charge conservation without specifically stating those two laws. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Silver, GL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS E502, Los Alamos, NM 87545 USA. NR 9 TC 7 Z9 7 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 2000 VL 245 IS 2 BP 229 EP 232 DI 10.1023/A:1006780126515 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 345MV UT WOS:000088820500001 ER PT J AU Fiskum, SK Riley, RG Thompson, CJ AF Fiskum, SK Riley, RG Thompson, CJ TI Preconcentration and analysis of strontium-90 and technetium-99 from Hanford groundwater using solid phase extraction SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID SAMPLES; DISKS AB Solid-phase extraction disks produced by 3M and Eichrom were evaluated for routine use in supporting the Hanford Groundwater Monitoring Project. Both disk formats contain Sr- or Tc-selective extractants, bound in a filter support, that act to preconcentrate and isolate the isotope of interest. The 3M Empore(TM) Sr Rad Disks and Tc Rad Disks were tested with respect to precision, accuracy, radiochemical yields, interferences, and volume-load variation. The Empore(TM) and Eichrom solid-phase extraction disks were applied to the Sr-90 and/or Tc-99 determination in representative Hanford groundwater samples with varying chemical and isotopic compositions. Results were compared to standard analytical methods. Both the Empore(TM) and Eichrom Tc extraction disks produced consistently higher radiochemical yields, lower detection limits, and greater accuracy than the standard analysis method. The Empore(TM) Sr extraction disks produced comparable radiochemical yields, detection limit, and accuracy relative to the standard method: however, total uncertainties were lower. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Fiskum, SK (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 14 TC 16 Z9 20 U1 3 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 2000 VL 245 IS 2 BP 261 EP 272 DI 10.1023/A:1006789816945 PG 12 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 345MV UT WOS:000088820500007 ER PT J AU Shi, Y Campbell, JA AF Shi, Y Campbell, JA TI Study of cyclization of chelating compounds using electrospray ionization mass spectrometry SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID CAPILLARY ELECTROPHORESIS; COMPLEXING AGENTS; DEGRADATION; WASTES; MECHANISM; ACIDS; EDTA AB Electrospray ionization mass spectrometry (ESI-MS) was used for the study of cyclization of organic chelating compounds (chelators). Four chelating compounds were studed: Symmetrical ethylenediaminediacetic acid (s-EDDA), Unsymmetrical ethylenediaminediacetic acid (u-EDDA), N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA), and N-(2-hydroxyethyl)iminodiacetic acid (HEIDA). The chelators were cyclized with treatments of acids and heating. The open and cyclized form of the chelators were semi-quantified by both positive and negative ion modes ESI-MS. The kinetics of chelator cyclization was studied as a function of reaction temperature and the pH of the matrix. The cyclization of s-EDDA was found to be a pseudo-first order reaction in s-EDDA and overall second order. The cyclizations of HEIDA and HEDTA are reversible reactions. Higher temperature and lower pH favors cyclization. C1 Battelle, Pacific NW Natl Lab, Richland, WA 99352 USA. RP Shi, Y (reprint author), Battelle, Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 27 TC 1 Z9 1 U1 2 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 2000 VL 245 IS 2 BP 293 EP 300 DI 10.1023/A:1006750102833 PG 8 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 345MV UT WOS:000088820500011 ER PT J AU Marek, T Szeles, C Molnar, G Borossay, J Vertes, A Lynn, KG AF Marek, T Szeles, C Molnar, G Borossay, J Vertes, A Lynn, KG TI On the behavior of [Zn(propyltetrazole)(6)](BF4)(2) Single crystal under high-vacuum conditions SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID POSITRON-ANNIHILATION; IRON(II) COMPLEXES; SPIN-CROSSOVER; TRANSITIONS; TETRAZOLES; LIGANDS; STATE AB We studied the long-term (190 hours) behaviour of [Zn(propyltetrazole)(6)](BF4)(2) single crystal under high-vacuum (HV) conditions (10(-8) torr) with a depth-sensitive technique of positron annihilation spectroscopy (PAS). The obtained data indicate the slow formation of a new near-surface structure which is formed by the decomposition of the [Zn(propyltetrazole)(6)](2+) ions. The assumption of such a decomposition process was confirmed by additional mass spectroscopic measurements. C1 Eotvos Lorand Univ, Dept Nucl Chem, H-1518 Budapest, Hungary. Eotvos Lorand Univ, Dept Gen & Inorgan Chem, H-1518 Budapest, Hungary. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Marek, T (reprint author), Eotvos Lorand Univ, Dept Nucl Chem, POB 32, H-1518 Budapest, Hungary. EM marek@para.chem.elte.hu RI Marek, Tamas/A-7606-2012; Molnar, Gabor/Q-6874-2016 OI Marek, Tamas/0000-0001-6076-4289; Molnar, Gabor/0000-0001-6032-6393 NR 15 TC 0 Z9 0 U1 1 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 2000 VL 245 IS 2 BP 329 EP 335 DI 10.1023/A:1006762505559 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 345MV UT WOS:000088820500016 ER PT J AU Marek, T Hanzel, D Szeles, C Suvegh, K Vertes, A Lynn, KG AF Marek, T Hanzel, D Szeles, C Suvegh, K Vertes, A Lynn, KG TI The limits of application of variable-energy slow positron beams for investigating TiN hard coatings prepared by PVD SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID THIN; CORROSION; FILMS; IRON AB Samples of TIN hard coatings prepared by physical vapour deposition (PVD) were investigated by means of depth-sensitive positron annihilation spectroscopy. The results indicate that the samples are at the limits of the applicability of this method presumably due to the high defect concentration. Our findings also show that, though the samples are thoroughly characterized by other independent methods, they might not be sufficient to explain all aspects of positron-solid interactions in these cases. C1 Eotvos Lorand Univ, Dept Nucl Chem, H-1518 Budapest, Hungary. Inst Josef Stefan, SI-1001 Ljubljana, Slovenia. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Marek, T (reprint author), Eotvos Lorand Univ, Dept Nucl Chem, POB 32, H-1518 Budapest, Hungary. EM marek@para.chem.elte.hu RI Hanzel, Darko/C-6211-2011; Marek, Tamas/A-7606-2012 OI Marek, Tamas/0000-0001-6076-4289 NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 2000 VL 245 IS 2 BP 347 EP 352 DI 10.1023/A:1006718724214 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 345MV UT WOS:000088820500019 ER PT J AU VanMiddlesworth, L Handl, J Johns, P AF VanMiddlesworth, L Handl, J Johns, P TI Iodine-129 in thyroid glands: A sensitive biological marker of fission product exposure (vol 243, pg 467, 2000) SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Correction ID I-129; ACCIDENT AB Iodine-129 may be no radiation hazard but it is a useful marker. Animal thyroids concentrate the isotope to 4 orders of magnitude greater than the intake. This results in a potential biological and physical indicator of radioactive contamination. Since 1943, I-129/I-127 ratio in animal thyroids from the Northern Hemisphere has increased 2 to 5 orders of magnitude. Since 1985, thyroids of deer, living near a nuclear reprocessing facility have contained I-129 which is 3 to 7 orders of magnitude greater than pre-nuclear levels. Limited measurements of I-129 in thyroids from the Southern Hemisphere have shown little increase. An appendix is presented to show that I-129 may be helpful to evaluate past radiation hazard from fission products. C1 Univ Tennessee, Memphis, TN 38163 USA. Univ Hannover, Hannover, Germany. Univ Georgia, Savannah River Ecol Lab, Aiken, SC USA. RP VanMiddlesworth, L (reprint author), Univ Tennessee, Memphis, TN 38163 USA. NR 15 TC 8 Z9 8 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 2000 VL 245 IS 2 BP 447 EP 453 DI 10.1023/A:1006720118279 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 345MV UT WOS:000088820500040 ER PT J AU Saito, T Terashima, T Azuma, M Takano, M Goto, T Ohta, H Utsumi, W Bordet, P Johnston, DC AF Saito, T Terashima, T Azuma, M Takano, M Goto, T Ohta, H Utsumi, W Bordet, P Johnston, DC TI Single crystal growth of the high pressure phase of (VO)(2)P2O7 at 3 GPa SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE high-pressure synthesis; single crystal; synchrotron XRD; ESR; magnetic susceptibility; S=1/2 Heisenberg AF alternating-exchange chain ID ALTERNATING-CHAIN COMPOUND; ANTIFERROMAGNETIC CHAINS; VANADYL PYROPHOSPHATE; EXCITATION SPECTRUM; MAGNETIC-PROPERTIES; SPIN GAP; SUPERCONDUCTIVITY; SUSCEPTIBILITY; LADDER; (VO)2P2O7 AB Single crystals of the high-pressure phase of (VO)(2)P2O7 were grown by slowly cooling the melt at 3 GPa, Relevant reactions at high pressure and high temperature were studied in advance by in situ X-ray diffraction (XRD) measurements, The crystal structure of the high-pressure phase was determined by single-crystal XRD, Magnetic susceptibility of the crystal was measured along the three principal axes and analyzed using a S = 1/2 Heisenberg AF alternating-exchange chain model, A good fit was obtained using the g values determined by ESR measurements, J(1)/k(B) = 131.6(1) K, and an alternation parameter of alpha = J(2)/J(1) = 0.8709(5). The spin gap was estimated to be Delta/k(B) = 33.4(2) K. (C) 2000 Academic Press. C1 Kyoto Univ, Inst Chem Res, Uji, Kyoto 6110011, Japan. Japan Sci & Technol Corp, CREST, Kawaguchi, Saitama 3320012, Japan. Kobe Univ, Fac Sci, Dept Phys, Nada Ku, Kobe, Hyogo 6578501, Japan. Kobe Univ, Venture Business Lab, Nada Ku, Kobe, Hyogo 6578501, Japan. Japan Atom Energy Res Inst, Dept Synchrotron Radiat Res, Sayo, Hyougo 6795148, Japan. CNRS, Cristallog Lab, F-38042 Grenoble 9, France. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Saito, T (reprint author), Kyoto Univ, Inst Chem Res, Uji, Kyoto 6110011, Japan. RI Azuma, Masaki/C-2945-2009 OI Azuma, Masaki/0000-0002-8378-321X NR 21 TC 34 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 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD AUG PY 2000 VL 153 IS 1 BP 124 EP 131 DI 10.1006/jssc.2000.8761 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 341QG UT WOS:000088600600016 ER PT J AU Moon, YU Curtis, RA Anderson, CO Blanch, HW Prausnitz, JM AF Moon, YU Curtis, RA Anderson, CO Blanch, HW Prausnitz, JM TI Protein-protein interactions in aqueous ammonium sulfate solutions. Lysozyme and bovine serum albumin (BSA) SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE potential of mean force; proteins; salts; intermolecular interactions; precipitation; crystallization ID CRYSTALLIZATION; FLUIDS; STATE AB Osmotic pressures have been measured to determine lysozyme-lysozyme, BSA-BSA, and lysosyme-BSA interactions for protein concentrations to 100 g-L-1 in an aqueous solution of ammonium sulfate at ambient temperature, as a function of ionic strength and pH. Osmotic second virial coefficients for lysozyme, for BSA, and for a mixture of BSA and lysozyme were calculated from the osmotic-pressure data for protein concentrations to 40 g-L-1. The osmotic second virial coefficient of lysozyme is slightly negative and becomes more negative with rising ionic strength and pH. The osmotic second virial coefficient for BSA is slightly positive, increasing with ionic strength and pH. The osmotic second virial cross coefficient of the mixture lies between the coefficients for lysozyme and BSA, indicating that the attractive forces for a lysozyme-BSA pair are intermediate between those for the lysozyme-lysozyme and BSA-BSA pairs. For protein concentrations less than 100 g-L-1, experimental osmotic-pressure data compare favorably with results from an adhesive hard-sphere model, which has previously been shown to fit osmotic compressibilities of lysozyme solutions. C1 SMIPC, Chungbuk Reg Headquarters, Cheongju City 363290, Chungbuk, South Korea. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Moon, YU (reprint author), SMIPC, Chungbuk Reg Headquarters, Cheongju City 363290, Chungbuk, South Korea. NR 26 TC 73 Z9 74 U1 0 U2 22 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD AUG PY 2000 VL 29 IS 8 BP 699 EP 717 DI 10.1023/A:1005112927213 PG 19 WC Chemistry, Physical SC Chemistry GA 341GN UT WOS:000088582800002 ER PT J AU Vuorinen, JE Schwarz, RB McCullough, C AF Vuorinen, JE Schwarz, RB McCullough, C TI Elastic constants of an aluminum-alumina unidirectional composite SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID FIBER AB The five independent second-order elastic constants of a transversely isotropic aluminum/alumina fiber composite have been measured for the first time using a resonant ultrasound spectroscopy technique. These data were used to deduce the elastic constants and engineering moduli for off-axis loading conditions. (C) 2000 Acoustical Society of America. [S0001-4966(00)01608-8]. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. 3M Co, Met Matrix Composite Program, St Paul, MN 55144 USA. RP Vuorinen, JE (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, MST-8,MS G755, Los Alamos, NM 87545 USA. RI Vuorinen, Jyrki/G-4256-2014; OI Vuorinen, Jyrki/0000-0002-7537-1557 NR 19 TC 9 Z9 9 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD AUG PY 2000 VL 108 IS 2 BP 574 EP 579 DI 10.1121/1.429588 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 342BX UT WOS:000088626300015 ER PT J AU Spoor, PS Swift, GW AF Spoor, PS Swift, GW TI The Huygens entrainment phenomenon and thermoacoustic engines SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The earliest known reference to the mode-locking, or entrainment, of two maintained oscillators is Christiaan Huygens' description of two pendulum clocks "falling into synchrony" when hung on the same wall. We describe an analogous phenomenon in acoustics-the mode-locking of two thermoacoustic engines which have their cases rigidly welded together, but which are otherwise uncoupled. This ''mass-coupling'' might compete with acoustic coupling when the latter is used to enforce antiphase mode-locking in such engines, for vibration cancellation. A simple theory relating the phase difference between the engines in the locked state to the corresponding ratio of their pressure amplitudes is in excellent agreement with theory and numerical simulations. The theory's prediction relating the phase difference to the engines' natural frequency difference is qualitatively confirmed by experiment, despite larger experimental uncertainties. The mass coupling is relatively weak compared to the aforementioned acoustic coupling, and in general occurs in antiphase, so we conclude that mass coupling will not interfere with vibration cancellation by acoustic coupling in most circumstances. (C) 2000 Acoustical Society of America. [S0001-4966(00)01708-2]. C1 Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Spoor, PS (reprint author), Clever Fellows Innovat Consortium, 302 10th St, Troy, NY 12180 USA. NR 13 TC 15 Z9 15 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD AUG PY 2000 VL 108 IS 2 BP 588 EP 599 DI 10.1121/1.429590 PG 12 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 342BX UT WOS:000088626300017 ER PT J AU Minervini, L Grimes, RW Sickafus, KE AF Minervini, L Grimes, RW Sickafus, KE TI Disorder in pyrochlore oxides SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SOLID-SOLUTIONS; FLUORITE; CONDUCTIVITY; STABILITY; ZIRCONATE; DIFFUSION AB Contour plots of disorder reaction energies across a wide variety of A(2)B(2)O(7) pyrochlore oxides have been produced, using atomistic simulation calculations based on energy-minimization techniques. The cations studied range from Lu3+ to La3+ on the A site and from Ti4+ to Ce4+ on the B site. The present results relate the experimentally observed stability range of the pyrochlore structure to A and B cation size and disorder. Disorder enthalpies decrease dramatically with increasing B cation size, while the rate of increase with A cation size depends markedly on the particular B cation. The association of anion Frenkel and cation antisite disorders is found to be of importance. C1 Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87454 USA. RP Minervini, L (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. NR 36 TC 278 Z9 285 U1 14 U2 76 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 2000 VL 83 IS 8 BP 1873 EP 1878 PG 6 WC Materials Science, Ceramics SC Materials Science GA 341ZR UT WOS:000088621300005 ER PT J AU Jones, RH Henager, CH Lewinsohn, CA Windisch, CF AF Jones, RH Henager, CH Lewinsohn, CA Windisch, CF TI Stress-corrosion cracking of silicon carbide fiber/silicon carbide composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMIC-MATRIX COMPOSITES; ELEVATED-TEMPERATURES; CONTINUOUS-FIBER; SIC FIBERS; OXIDATION MECHANISMS; NICALON FIBERS; KINETICS; GROWTH; STRENGTH; BEHAVIOR AB Ceramic-matrix composites are being developed to operate at elevated temperatures and in oxidizing environments, Considerable improvements have been made in the creep resistance of SiC fibers and, hence, in the high-temperature properties of SiC fiber/SiC (SiCf/SiC) composites; however, more must be known about the stability of these materials in oxidizing environments before they are widely accepted. Experimental weight change and crack growth data support the conclusion that the oxygen-enhanced track growth of SiCf/SiC occurs by more than one mechanism, depending on the experimental conditions. These data suggest an oxidation embrittlement mechanism (OEM) at temperatures <1373 K and high oxygen pressures and an interphase removal mechanism (IRM) at temperatures of greater than or similar to 700 K and low oxygen pressures. The OEM results from the reaction of oxygen with SiC to form a glass layer on the fiber or within the fiber-matrix interphase region. The fracture stress of the fiber is decreased if this layer is thicker than a critical value (d > d(c)) and the temperature below a critical value (T < T-g), such that a sharp crack can be sustained in the layer, The IRM results from the oxidation of the interfacial layer and the resulting decrease of stress that is carried by the bridging fibers. Interphase removal contributes to subcritical crack growth by decreasing the fiber-bridging stresses and, hence, increasing the crack-tip stress. The IRM occurs over a wide range of temperatures for d < d(c) and may occur at T > T-g for d > d(c). This paper summarizes the evidence for the existence of these two mechanisms and attempts to define the conditions for their operation. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Jones, RH (reprint author), Pacific NW Lab, Richland, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 44 TC 14 Z9 14 U1 1 U2 9 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 2000 VL 83 IS 8 BP 1999 EP 2005 PG 7 WC Materials Science, Ceramics SC Materials Science GA 341ZR UT WOS:000088621300024 ER PT J AU Chen, D Zhang, XF Ritchie, RO AF Chen, D Zhang, XF Ritchie, RO TI Effects of grain-boundary structure on the strength, toughness, and cyclic-fatigue properties of a monolithic silicon carbide SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID B-C ADDITIONS; CRACK-GROWTH; CERAMICS AB An in situ-toughened silicon carbide (ABC-SiC) has been examined in the as-processed condition, where the grain-boundary films are predominantly amorphous, and Following thermal exposure at a temperature of 1300 degrees C, where the films become fully crystalline. Previous work has shown that, at elevated temperatures (up to 1300 degrees C), after the grain-boundary films crystallize in situ, only a marginal reduction in strength, fracture toughness, and cyclic-fatigue crack-growth properties is observed, in comparison with those of the as processed microstructure at 25 degrees C, In the present study, the effect of such crystallization on the subsequent strength, toughness, and fatigue properties at 25 degrees C is examined. Little or no degradation is observed in the room-temperature properties with the crystallized grain-boundary films/phase; in fact, although the strength shows a small reduction (similar to 3%), the fracture toughness and fatigue-crack-growth threshold both increase by similar to 20%, compared with that of the as-processed structure with amorphons grain-boundary films. C1 Univ Calif Berkeley, Div Mat Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Chen, D (reprint author), Univ Calif Berkeley, Div Mat Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 10 TC 27 Z9 27 U1 0 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 2000 VL 83 IS 8 BP 2079 EP 2081 PG 3 WC Materials Science, Ceramics SC Materials Science GA 341ZR UT WOS:000088621300036 ER PT J AU Gaffney, KJ Liu, SH Miller, AD Szymanski, P Harris, CB AF Gaffney, KJ Liu, SH Miller, AD Szymanski, P Harris, CB TI The adsorbate electron affinity dependence of femtosecond electron dynamics at dielectric/metal interfaces SO JOURNAL OF THE CHINESE CHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT 11th International Symposium on Ultrafast Phenomena in Spectroscopy (ups 99) CY OCT 25-29, 1999 CL TAIPEI, TAIWAN SP Natl Sci Council, Minist Educ, Acad Sinica Taiwan DE Adsorbate electron affinity; interfacial electronic structure; femtosecond two photon photoemission; dielectric/metal interfaces ID RESOLVED 2-PHOTON PHOTOEMISSION; METAL-SURFACES; ENERGY RELAXATION; HOT-ELECTRONS; STATES; LIFETIMES; CO; SPECTROSCOPY; EXCITATION; ADSORPTION AB The two photon photoemission technique has been utilized to investigate the adsorbate electron affinity dependence of interfacial electron transfer dynamics. The comparison of calculated and experimental results highlight a brief discussion of a dielectric continuum model. For the n-heptane/Ag(111) and the benzene/ Ag(111) interfaces, the model effectively reproduces experimental image potential state properties. The model fails to adequately describe the influence of anthracene adsorbates on image potential state lifetimes, as demonstrated by the experimental and theoretical results. The experimental n = 1 lifetime of 1200 femtoseconds and binding energy of -0.53 eV for the anthracene bilayer differ greatly from the calculated values of 40 femtoseconds and -1.4 eV. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Harris, CB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 30 TC 5 Z9 5 U1 0 U2 1 PU CHINESE CHEM SOC PI TAIPEI PA PO BOX 609, TAIPEI 10099, TAIWAN SN 0009-4536 J9 J CHIN CHEM SOC-TAIP JI J. Chin. Chem. Soc. PD AUG PY 2000 VL 47 IS 4A SI SI BP 759 EP 763 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 351EZ UT WOS:000089146000026 ER PT J AU Kavan, L Attia, A Lenzmann, F Elder, SH Gratzel, M AF Kavan, L Attia, A Lenzmann, F Elder, SH Gratzel, M TI Lithium insertion into zirconia-stabilized mesoscopic TiO2 (anatase) SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MESOPOROUS METAL-OXIDES; LI+ ION INSERTION; NANOPOROUS FILMS; ELECTRODES; TITANIA AB Lithium insertion into nanotextured anatase. either pure or stabilized with zirconia, was studied using cyclic voltammetry. The voltammograms were sensitive to various morphologies of the tested electrodes. Special attention was paid to the zirconia-stabilized molecular sieve, PNNL-1 (Pacific Northwest National Laboratory), which was prepared by a surfactant-templated route. The voltammetric peak-to-peak splitting decreases monotonic ally with the electrode specific surface area. The charge-transfer rate constants decrease in the same series. PNNL-1 is more stable against prolonged heat-treatment, as compared to ordinary nanocrystalline anatase. The latter exhibits thermal particle growth and. presumably, partial phase transformation to rutile. PNNL-1 presents a promising model electrode material for Li-ion batteries, although its faradaic capacity is limited by the presence of a nonactive stabilizer (zirconia). (C) 2000 The Electrochemical Society. S0013-4651(00)01-114-9. All rights reserved. C1 J Heyrovsky Inst Phys Chem & Electrochem, CZ-18223 Prague, Czech Republic. Swiss Fed Inst Technol, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland. Pacific NW Lab, Richland, WA 99352 USA. RP Kavan, L (reprint author), J Heyrovsky Inst Phys Chem & Electrochem, CZ-18223 Prague, Czech Republic. RI Attia, Adel/B-9549-2008; Graetzel, Michael/G-4870-2011; Kavan, Ladislav/F-5218-2014 NR 25 TC 70 Z9 71 U1 2 U2 18 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD AUG PY 2000 VL 147 IS 8 BP 2897 EP 2902 DI 10.1149/1.1393623 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 344FH UT WOS:000088748200009 ER PT J AU Balasubramanian, M Sun, X Yang, XQ McBreen, J AF Balasubramanian, M Sun, X Yang, XQ McBreen, J TI In situ x-ray absorption studies of a high-rate LiNi0.85Co0.15O2 cathode material SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID FINE-STRUCTURE ANALYSIS; LINIO2; BATTERY AB We have performed an ill situ X-ray absorption spectroscopy (XAS) study to investigate me evolution of the local electronic and atomic structure of a high-surface-area Li1-xNi0.85Co0.15O2 (0 less than or equal to x less than or equal to 1) cathode material during electrochemical delithiation. We have measured the changes in the oxidation state, bond distance, coordination number, and local disorder of Ni and Co absorbers as a function of the state of charge of the material. The X-ray absorption near edge spectra shows that delithiation of Li1-xNi0.85Co0.15O2 leads to the oxidation of Ni3+ to Ni4+. Ni atoms oxidize during the initial stages of charge and attain a maximum oxidation state of Ni4+ well before the end of charge (x approximate to 0.85). On the other hand, Co atoms do not oxidize during the initial stages of charge but oxidize close to the end of charge. Analysis of the extended X-ray absorption fine structure (EXAFS) shows that the oxidation of Ni3+ to Ni4+ leads to the expected reduction in the Jahn-Teller effect. Also, to within the accuracy of the EXAFS technique, Co absorbers occupy Ni-type sites in the NiO2 slabs. Furthermore, Co doping has a strong effect on the overall structural evolution and leads to a slight expansion of the a and b axes close to the end of charge. (C) 2000 The Electrochemical at Society. S0013-4651(00)01-042-9. All rights reserved. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Chem & Mat Sci, Upton, NY 11973 USA. RP Balasubramanian, M (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Chem & Mat Sci, Upton, NY 11973 USA. NR 17 TC 79 Z9 79 U1 4 U2 34 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD AUG PY 2000 VL 147 IS 8 BP 2903 EP 2909 DI 10.1149/1.1393624 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 344FH UT WOS:000088748200010 ER PT J AU Belanger, D Ren, XM Davey, J Uribe, F Gottesfeld, S AF Belanger, D Ren, XM Davey, J Uribe, F Gottesfeld, S TI Characterization and long-term performance of polyaniline-based electrochemical capacitors SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CHARGE STORAGE APPLICATIONS; CONDUCTING POLYMERS; SUBSTITUTED POLYPHENYLTHIOPHENES; IMPEDANCE SPECTROSCOPY; RUTHENIUM OXIDE; DOUBLE-LAYER; ELECTRODES; SUPERCAPACITORS; FILMS; CELLS AB The performance of polyaniline-based electrochemical capacitors was evaluated under various experimental conditions. The capacitor consisted of two platinized tantalum foils coated with polyaniline as the active material, a separator, and an appropriate aqueous electrolyte solution. The polyaniline coatings were formed galvanostatically 5 mA cm(-2) from a 0.1 M aniline +1.0 M HCl aqueous solution. With a polyaniline lending formed by a deposition charge of 20 C cm(-2) on each electrode and with a 4.0 M HBF4 aqueous solution as the electrolyte for an optimized capacitor, energy and power densities of 2.7 Wh kg(-1) and 1.0 kW kg(-1) (of active polymer) were achieved, respectively. Cyclic voltammograms for both positive and negative polyaniline electrodes of the capacitor before and after 20,000 cycles showed only a 5% loss of polyaniline electroactivity, which was smaller than the observed 33% decrease in the discharge capacity of the capacitor. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the capacitors and to understand their initial performance loss upon constant-current cycling. (C) 2000 The Electrochemical Society. S0013-4651(00)02-077-2. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Belanger, D (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. RI ren, xiaoming/F-3953-2011 NR 41 TC 155 Z9 159 U1 5 U2 50 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD AUG PY 2000 VL 147 IS 8 BP 2923 EP 2929 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 344FH UT WOS:000088748200012 ER PT J AU Hafezi, H Newman, J AF Hafezi, H Newman, J TI Verification and analysis of transference number measurements by the galvanostatic polarization method SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID POLYMER ELECTROLYTES; TRANSPORT-PROPERTIES; NITRATE; SYSTEM; RAMAN AB Measurements of the Ag+ transference numbers in 0.1025 and 1.010 M aqueous silver nitrate solutions were used to verify the accuracy of the galvanostatic polarization method for transference number determinations in concentrated solutions of binary electrolytes. Simulations were performed to analyze the experimental data and sources of error. Experimental results were within 4% of literature values at 0.1025 M and within 9% at 1.010 M, the latter presumably due to a deviation from the method's assumption of a convection-free system. The method should be immune to convection when used in polymer electrolytes (for which it was originally developed) and is expected to be accurate to 4% or better in such systems. Three improvements, i.e., a new extrapolation method, a refined fitting procedure, and a means of identifying problematic runs have also been incorporated into the galvanostatic polarization method and are described. (C) 2000 The Electrochemical Society. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Hafezi, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Newman, John/B-8650-2008 OI Newman, John/0000-0002-9267-4525 NR 41 TC 27 Z9 27 U1 0 U2 14 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD AUG PY 2000 VL 147 IS 8 BP 3036 EP 3042 DI 10.1149/1.1393644 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 344FH UT WOS:000088748200030 ER PT J AU Thrall, KD Vucelick, ME Gies, RA Zangar, RC Weitz, KK Poet, TS Springer, DL Grant, DM Benson, JM AF Thrall, KD Vucelick, ME Gies, RA Zangar, RC Weitz, KK Poet, TS Springer, DL Grant, DM Benson, JM TI Comparative metabolism of carbon tetrachloride in rats, mice, and hamsters using gas uptake and PBPK modeling SO JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH-PART A LA English DT Article ID PHARMACOKINETIC MODEL; METHYLENE-CHLORIDE; IN-VITRO; LIVER; CYTOCHROME-P-450; RADICALS; BLOOD AB No study has comprehensively compared the rate of metabolism of carbon tetrachloride (CCl4) across species. Therefore, the in vivo metabolism of CCl4 was evaluated using groups of male animals (F344 rats, B6C3F(1) mice, and Syrian hamsters) exposed to 40-1800 ppm CCl4 in a closed, recirculating gas-uptake system. For each species, an optimal fit of the family of uptake curves was obtained by adjusting Michaelis-Menten metabolic constants K-m (affinity) and Vmax (capacity) using a physiologically based pharmacokinetic (PBPK) model. The results show that the mouse has a slightly higher capacity and lower affinity for metabolizing CCl4 compared to the rat, while the hamster has a higher capacity and lower affinity than either rat or mouse. A comparison of the V-max to K-m ratio, normalized for milligrams of liver protein (L/h/mg) across species, indicates that hamsters metabolize more CCl4 than either rats or mice, and should be more susceptible to CCl4-induced hepatotoxicity. These species comparisons were evaluated against toxicokinetic studies conducted in animals exposed by nose-only inhalation to 20 ppm C-14-labeled CCl4 for 4 h. The toxicokinetic study results are consistent with the in vivo rates of metabolism, with rats eliminating less radioactivity associated with metabolism ((CO2)-C-14 and urine/feces) and more radioactivity associated with the parent compound (radioactivity trapped on charcoal) compared to either hamsters or mice. The in vivo metabolic constants determined here, together with in vitro constants determined using rat, mouse, hamster, and human liver microsomes, were used to estimate human in vivo metabolic rates of 1.49 mg/h/kg body weight and 0.25 mg/L for V-max and K-m, respectively. Normalizing the rate of metabolism (V-max/K-m) by milligrams liver protein, the rate of metabolism of CCl4 differs across species, with hamster > mouse > rat > human. C1 Pacific NW Lab, Mol Biosci Dept, Richland, WA 99352 USA. Washington State Univ, Associated Western Univ, Richland, WA USA. Lovelace Resp Res Inst, Albuquerque, NM USA. RP Thrall, KD (reprint author), Pacific NW Lab, Mol Biosci Dept, POB 999,Mail Stop P7-59, Richland, WA 99352 USA. NR 30 TC 31 Z9 32 U1 1 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 1528-7394 J9 J TOXICOL ENV HEAL A JI J. TOXICOL. ENV. HEALTH PT A PD AUG PY 2000 VL 60 IS 8 BP 531 EP 548 DI 10.1080/00984100050082085 PG 18 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 341DT UT WOS:000088576300002 PM 10983521 ER PT J AU Holcomb, GR AF Holcomb, GR TI Hot corrosion in a temperature gradient SO MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION LA English DT Article; Proceedings Paper CT CORROSION/99 NACE Annual Conference and Exhibition CY APR 25-30, 1999 CL SAN ANTONIO, TEXAS ID HAFNIUM CARBIDE; FUSED NA2SO4; BASE ALLOYS; OXIDATION; 900-DEGREES-C; MECHANISM; NICKEL AB Hot corrosion is the accelerated attack of materials at elevated temperatures that is induced by a thin film of fused salt. Many materials that experience hot corrosion are exposed to high heat fluxes and temperature gradients. The hot corrosion of metals can be described by the dissolution of a protective metal oxide into the fused salt and the subsequent precipitation of the metal oxide in a nonprotective form. Rapp and Goto have established a criterion for the sustained hot corrosion of a pure metal that the solubility gradient of the protective oxide in the salt film must be negative at the oxide/salt interface. The influence of a temperature gradient on the metal oxide solubility gradient (and the predicted hot corrosion susceptibility) is discussed. Solubility data for NiO in Na2SO4 are used to illustrate the effects of a temperature gradient. The effects of a temperature gradient were determined by examining various combinations of dissolution reactions, oxidants, and transport kinetics. Based on these results, and the thinness of the molten salt films, temperature gradients are not expected to be of importance to hot corrosion fluxing mechanisms. C1 US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. RP Holcomb, GR (reprint author), US Dept Energy, Albany Res Ctr, 1450 Queen Ave SW, Albany, OR 97321 USA. RI Holcomb, Gordon/G-9070-2013 OI Holcomb, Gordon/0000-0003-3542-5319 NR 22 TC 1 Z9 1 U1 2 U2 4 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0947-5117 J9 MATER CORROS JI Mater. Corros. PD AUG PY 2000 VL 51 IS 8 BP 564 EP 569 DI 10.1002/1521-4176(200008)51:8<564::AID-MACO564>3.0.CO;2-4 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 350DV UT WOS:000089086200005 ER PT J AU Lewis, GK Schlienger, E AF Lewis, GK Schlienger, E TI Practical considerations and capabilities for laser assisted direct metal deposition SO MATERIALS & DESIGN LA English DT Article DE laser; deposition; fabrication; layered deposition; rapid prototyping; solid free-form fabrication AB Laser assisted direct metal deposition refers to the additive layered manufacturing technology for building components from a computer-aided design (CAD) model. A motion control program, developed from the CAD model of a desired metal component, is used to control the motion of a laser focal spot to trace all areas of the part, typically a planar layer at a time. Metal powders, injected into the laser focal zone, are melted and then re-solidify into fully dense metal in the wake of the moving molten pool created by the laser beam. Successive layers are then stacked to produce the entire component volume of fused metal representing the desired CAD model. Development of this technology has been pursued at both Los Alamos and Sandia National Laboratories and has resulted in the Directed Light Fabrication (DLF) and Laser Engineered Net Shaping (LENS(TM)) processes. These processes have been proven feasible for fabricating components from nearly any metal system to near-net shape accuracy with mechanical properties approaching and in some cases exceeding the properties found in conventionally processed wrought structures. Single step processing by LENS and DLF produce cost savings realized by elimination of conventional multi-step thermo-mechanical processing. Design features such as internal cavities or over-hanging features can be made without joined assemblies. Hard to process materials such as intermetallics, refractory metals, and high temperature alloys can be processed in a single step. Functionally graded compositions can be created within three-dimensional components to vary the properties to match localized requirements due to the service environment. The technology offers the designer a rapid prototyping capability at the push of a button, without the need to fabricate dyes or use forming equipment or extensive machining and joining processes to produce a part. Future development is still required for these processes to be commercially accepted and used in industry. Parts are deposited with a surface roughness of 10 mu m, arithmetic average, making a secondary finishing operation necessary for some applications to achieve high accuracy and polished surface texture. Residual stress measurement and control is also required to avoid distortion of deposited components. Motion path and control code needs to be optimized to reduce overall process time from the CAD model to the finished part. (C) Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 19 TC 193 Z9 206 U1 27 U2 185 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0261-3069 J9 MATER DESIGN JI Mater. Des. PD AUG PY 2000 VL 21 IS 4 BP 417 EP 423 DI 10.1016/S0261-3069(99)00078-3 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 300DX UT WOS:000086238500023 ER PT J AU Rawn, CJ Barsoum, MW El-Raghy, T Procipio, A Hoffmann, CM Hubbard, CR AF Rawn, CJ Barsoum, MW El-Raghy, T Procipio, A Hoffmann, CM Hubbard, CR TI Structure of Ti4AlN3 - a layered M(n+1)AX(n) nitride SO MATERIALS RESEARCH BULLETIN LA English DT Article DE nitrides; X-ray diffraction (XRD); neutron scattering; crystal structure ID AL-N SYSTEM; TERNARY NITRIDE; TI3SIC2 AB Recent high resolution transmission electron microscopy and electron probe X-ray microanalysis show that the compound originally thought to be Ti3Al2N2 is Ti4AlN3. In this paper we report on the crystal structure determination by Rietveld refinement on neutron and X-ray powder diffraction data. Ti4AlN3 crystallizes with a hexagonal unit cell, space group P6(3)/mmc, and with lattice parameters a = 2.9880(2) and c = 23.372(2) Angstrom. The stacking sequence is such that every four layers of Ti atoms is separated by a layer of Al atoms. The N atoms occupy octahedral sites between the Ti atoms making up a network of corner shared octahedra. This compound is closely related to other layered, ternary, machinable, hexagonal nitrides and carbides, namely, M2AX and M3AX2, where M is an early transition metal, A is a A-group element and X is either C and/or N. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Drexel Univ, Dept Mat Engn, Philadelphia, PA 19104 USA. RP Rawn, CJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 14 TC 73 Z9 78 U1 5 U2 29 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD AUG PY 2000 VL 35 IS 11 BP 1785 EP 1796 DI 10.1016/S0025-5408(00)00383-4 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 394EF UT WOS:000166510600006 ER PT J AU Clatterbuck, DM Chan, JW Morris, JW AF Clatterbuck, DM Chan, JW Morris, JW TI The influence of a magnetic field on the fracture toughness of ferromagnetic steel SO MATERIALS TRANSACTIONS JIM LA English DT Article DE fracture touchness; magnetic field; ferromagnetic steel; mechanical properties; magnetoelastic stress AB The limited data available suggest that the mechanical properties of ferromagnetic alloys are not significantly affected by high magnetic fields. As further evidence, the present paper includes data on the fracture toughness of Incoloy 908, a ferromagnetic austenite, in fields up to 14T at 4.2 K. The field has no significant effect on the toughness. To interpret these results we review the available theoretical work on the fracture of ferromagnetic materials in magnetic fields. The model of Shindo is particularly relevant, and suggests that there is no measurable effect on the toughness of ferromagnetic steel at fields below about 25 T and no significant effect until the field exceeds 75 T. Interestingly, the theory does suggest a possible increase in the toughness of steels with very high magnetic permeability at fields below saturation. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Clatterbuck, DM (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. NR 24 TC 14 Z9 15 U1 0 U2 6 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI, 980, JAPAN SN 0916-1821 J9 MATER T JIM JI Mater. Trans. JIM PD AUG PY 2000 VL 41 IS 8 BP 888 EP 892 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 363LP UT WOS:000089837400003 ER PT J AU Yokoi, H Tozer, SW Kakudate, Y Usuba, S Kim, Y Takeyama, S Wojtowicz, T Karczewski, G Kossut, J AF Yokoi, H Tozer, SW Kakudate, Y Usuba, S Kim, Y Takeyama, S Wojtowicz, T Karczewski, G Kossut, J TI Pressure induced quenching of exciton photoluminescence and its recovery by magnetic field in cadmium telluride/cadmium manganese telluride quantum wells SO MATERIALS TRANSACTIONS JIM LA English DT Article DE cadmium telluride/cadmium manganese telluride single quantum well; photoluminescence; exciton; pressure induced extinction; magnetic field induced luminescence; dissipation of exciton energy ID SEMICONDUCTORS AB We have conducted photoluminescence (PL) measurements under hydrostatic pressures to 1.6 GPa and magnetic fields to 60 T at low temperatures in a 1.0 nm thick CdTe/Cd1-xMnxTe (x = 0.4) single quantum well (SQW). A novel phenomenon in which an exciton PL peak from the well vanishes at 1.6 GPa and is restored by the application of a high magnetic field, was observed. We examine the possibility that the exciton energy might be dissipated to Mn 3d-states. C1 Natl Inst Mat & Chem Res, Tsukuba, Ibaraki 3058565, Japan. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Chiba Univ, Fac Sci, Chiba 2638522, Japan. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. RP Yokoi, H (reprint author), Natl Inst Mat & Chem Res, Tsukuba, Ibaraki 3058565, Japan. RI Kossut, Jacek/K-9481-2016; Wojtowicz, Tomasz/A-2887-2017 OI Kossut, Jacek/0000-0001-6165-3169; NR 6 TC 0 Z9 0 U1 0 U2 1 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI, 980, JAPAN SN 0916-1821 J9 MATER T JIM JI Mater. Trans. JIM PD AUG PY 2000 VL 41 IS 8 BP 1052 EP 1054 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 363LP UT WOS:000089837400031 ER PT J AU Tartakovsky, DM Guadagnini, A Guadagnini, L AF Tartakovsky, DM Guadagnini, A Guadagnini, L TI Effective hydraulic conductivity and transmissivity for heterogeneous aquifers SO MATHEMATICAL GEOLOGY LA English DT Article DE groundwater; upscaling; effective hydraulic conductivity; transmissivity; stochastic ID MEDIA; FLOW AB Regional scale models of groundwater flow and transport often employ domain discretizations with grid blocks larger than typical scales of field data. For heterogeneous formations, this difference in scales is often handled by using effective (upscaled) parameters. We investigate the problem of upscaling hydraulic conductivity and transmissivity from a small scale of measurement to a larger scale of grid blocks. Transmissivity statistics is expressed in terms of statistics of hydraulic conductivity and expressions for the effective (upscaled) hydraulic conductivity K(eff) and transmissivity T(eff) for steady state flow in confined heterogeneous aquifers are derived by means of stochastic averaging and perturbation analysis. These expressions reveal that the commonly used relation T(eff) = BK(eff), where B is the confined aquifer thickness, is not generally valid. C1 Los Alamos Natl Lab, Sci Comp Grp CIC 19, Los Alamos, NM 87545 USA. Politecn Milan, DIIAR, I-20133 Milan, Italy. RP Tartakovsky, DM (reprint author), Los Alamos Natl Lab, Sci Comp Grp CIC 19, POB 1663, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013 NR 12 TC 9 Z9 9 U1 3 U2 5 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0882-8121 J9 MATH GEOL JI Math. Geol. PD AUG PY 2000 VL 32 IS 6 BP 751 EP 759 DI 10.1023/A:1007546607242 PG 9 WC Geosciences, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Geology; Mathematics GA 336FJ UT WOS:000088291000005 ER PT J AU Raylman, RR Majewski, S Wojcik, R Weisenberger, AG Kross, B Popov, V Bishop, HA AF Raylman, RR Majewski, S Wojcik, R Weisenberger, AG Kross, B Popov, V Bishop, HA TI The potential role of positron emission mammography for detection of breast cancer. A phantom study SO MEDICAL PHYSICS LA English DT Article DE breast cancer; positron emission mammography; radiation detectors ID SCINTILLATION CAMERA; COMPUTED-TOMOGRAPHY; PET; MASSES; SCINTIMAMMOGRAPHY; CARCINOMA; PSPMT; TECHNETIUM-99M-SESTAMIBI; TC-99M-SESTAMIBI; QUANTITATION AB Positron emission mammography (PEM) is a new, specialized imaging modality utilizing PET radiopharmaceuticals to detect breast cancer. The capabilities and limitations of PEM in detecting breast tumors were investigated with a series of phantom experiments. The PEM imager was mounted on a standard Lorad biopsy table (separated by 18 cm). In the initial phase of the investigation, basic scanner parameters (resolution, sensitivity, and scatter fraction) were measured. The effects of a number of breast imaging parameters (length of acquisition, breast thickness, and breast density) on detection of breast lesions were then explored utilizing special phantoms. Moderately compressed breasts were simulated with a block of gelatin containing amounts of FDG consistent with 370 MBq injections. Lesions were simulated with four hollow spheres (inner diameters=5 mm, 8 mm, 12 mm, and 15 mm) filled with amounts of FDG representative of uptake in malignant breast tumors (target-to-background concentration ratio=8.5:1). Resolution at the center of the imager was 3.9 mm, sensitivity was 0.059 kcps/kBq/ml and the Compton scatter fraction was similar to 12%. Objects as small as 8 mm in diameter could be detected after 30 s of data acquisition; 5 mm spheres were detectable after 300 s. Object detection capabilities were reduced with increasing breast thickness. In thin compressed breasts (2 cm) even the smallest sphere (5 mm in diameter) could be detected; increasing breast thickness increased the minimum detectable sphere diameter to 8 mm. increased background activity caused by FDG uptake in metabolically active normal tissue more prevalent in radiodense breasts compared to "fatty" breasts was simulated and shown to reduce the minimum detectable lesion size to 12 mm for the densest breasts. These results demonstrate the potential of PEM for the detection of breast lesions. The addition of the system to a standard biopsy apparatus indicates its potential for use to guide some core biopsies of breast cancers. (C) 2000 American Association of Physicists in Medicine. [S0094-2405(00)03008-X]. C1 W Virginia Univ, Hlth Sci Ctr, Dept Radiol, Ctr Adv Imaging, Morgantown, WV 26506 USA. Jefferson Lab, Detector Grp, Newport News, VA 23606 USA. RP Raylman, RR (reprint author), W Virginia Univ, Hlth Sci Ctr, Dept Radiol, Ctr Adv Imaging, Box 9236, Morgantown, WV 26506 USA. FU NCI NIH HHS [1 R21 CA82752-01] NR 42 TC 55 Z9 56 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD AUG PY 2000 VL 27 IS 8 BP 1943 EP 1954 DI 10.1118/1.1287439 PG 12 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 347KM UT WOS:000088928300028 PM 10984240 ER PT J AU Goto, DM Bingert, JF Chen, SR Gray, GT Garrett, RK AF Goto, DM Bingert, JF Chen, SR Gray, GT Garrett, RK TI The mechanical threshold stress constitutive-strength model description of HY-100 steel SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID LARGE-STRAIN DEFORMATION AB A generalized three-term mechanical threshold stress (MTS) strength model description, considering athermal, thermal, and strain-hardening contributions to flow stress, is employed to characterize the constitutive stress-strain response of HY-100 steel. Aspects of the MTS framework pertinent to United States Navy HY steels are discussed, and a calibration methodology is presented for determining MTS strength model parameters. In addition, a linear strain-hardening modification to the existing structure-evolution expression (flow-stress saturation) is proposed to better describe the large-strain strain-hardening behavior. Polycrystalline plasticity calculations suggest that the linear-lice hardening behavior is a consequence of deformation-path-dependent texture evolution. Calculation results are applied to MTS model stress-strain predictions and, in part, help explain the differences between compression and torsion test data. C1 USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Goto, DM (reprint author), USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. NR 23 TC 26 Z9 26 U1 0 U2 7 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 2000 VL 31 IS 8 BP 1985 EP 1996 DI 10.1007/s11661-000-0226-8 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 344HP UT WOS:000088753400010 ER PT J AU Kaschner, GC Gray, GT AF Kaschner, GC Gray, GT TI The influence of crystallographic texture and interstitial impurities on the mechanical behavior of zirconium SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID STRAIN-RATE; TITANIUM; TEMPERATURE; ZR AB Development of physically based constitutive models capable of simultaneously describing slip, twinning, and anisotropy requires knowledge of the coincident influence of each on mechanical response. In this article, the influence of interstitial impurities and texture on twinning in zirconium (Zr), in addition to variations in strain rate and temperature, are examined, to probe their effects on substructure evolution and mechanical behavior. The compressive-yield responses of both high-purity (HP) crystal-bar and lower-purity (LP) zirconium were found to depend on the loading orientation relative to the c-axis of the hcp cell, the applied strain rate, which varied between 0.001 and 3500/s, and the test temperature, which varied between 77 and 298 K. The rate of strain hardening in zirconium was seen to depend on the controlling defect-storage mechanism as a function of texture, strain rate, and temperature. The substructure evolution of HP zirconium was also observed to be a function of the applied strain rate and test temperature. The substructure of HP zirconium was seen to display a greater incidence of deformation twinning when deformed at a high strain rate at 298 K or quasi-statically at 77 K. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kaschner, GC (reprint author), Univ Calif Los Alamos Natl Lab, MST 8, Los Alamos, NM 87545 USA. RI Kaschner, George/H-4445-2013 NR 18 TC 59 Z9 61 U1 1 U2 15 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 2000 VL 31 IS 8 BP 1997 EP 2003 DI 10.1007/s11661-000-0227-7 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 344HP UT WOS:000088753400011 ER PT J AU Tetenbaum, M AF Tetenbaum, M TI Thermodynamic and nonstoichiometric behavior of promising Hi-Tc cuprate systems via electromotive force measurements: A short review SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article; Proceedings Paper CT Milton Blander Symposium on Thermodynamic Predictions and Application at the TMS Annual Meeting CY MAR 01-02, 1999 CL SAN DIEGO, CA SP TMS Extract & Process Div, ASM Thermodynam &v PHase Equilibrium Comm ID OXYGEN PARTIAL-PRESSURE; LEAD-DOPED BI-2223; PHASE-STABILITY; THIN-FILMS; STOICHIOMETRY; SUPERCONDUCTOR AB Electromotive force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made on the YBa(2)Cu(3)O(x), GdBa(2)Cu(3)O(x), NdBa(2)Cu(3)O(x), and bismuth cuprate systems in the temperature range similar to 400 degrees C to 750 degrees C by means of an oxygen titration technique with an yttria-stabilized zirconia electrolyte. The shapes of the 400 degrees C isotherms as a function of oxygen stoichiometry for the Gd and Nd cuprate systems suggest the presence of miscibility gaps at values of x that are higher than those in the YBa(2)Cu(3)O(x) system. For a given oxygen stoichiometry, oxygen partial pressures above GdBa(2)Cu(3)O(x) and NdBa(2)Cu(3)O(x) are higher (above x = 6.5) than that for the promising YBa(2)Cu(3)O(x) system. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Tetenbaum, M (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD AUG PY 2000 VL 31 IS 4 BP 661 EP 666 DI 10.1007/s11663-000-0104-1 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 341YF UT WOS:000088618000013 ER PT J AU Zhu, YT Lowe, TC AF Zhu, YT Lowe, TC TI Application of, and precautions for the use of, the rule of additivity in phase transformation SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article; Proceedings Paper CT Milton Blander Symposium on Thermodynamic Predictions and Application at the TMS Annual Meeting CY MAR 01-02, 1999 CL SAN DIEGO, CA SP TMS Extract & Process Div, ASM Thermodynam &v PHase Equilibrium Comm ID AUSTENITE-PEARLITE TRANSFORMATION; NONCONTINUOUS COOLING CONDITIONS; DIFFERENTIAL THERMAL-ANALYSIS; ISOTHERMAL TRANSFORMATION; CARBON-STEEL; KINETICS; TEMPERATURE; PRECIPITATION; NUCLEATION; PRINCIPLE AB The rule of additivity was first proposed for predicting the incubation time for nucleation of solid phases during continuous-cooling phase transformations, and has since been widely used for both the nucleation incubation and the entire process of phase transformation. While having been successfully used to calculate the transformed volume fraction during continuous cooling in many steel alloy systems, there is experimental evidence which shows that the rule of additivity is not rigorously valid for describing the incubation time for nucleation. We have recently used the classical nucleation theory to demonstrate the limits of validity of the rule of additivity. The general condition for the rule of additivity to be valid for phase transformation is that the kinetics of phase transformation be a state function independent of temperature history. In practice, the relative error caused by using the rule of additivity may be negligibly small in many cases. For better accuracy, the incubation time for nucleation should be excluded when applying the rule of additivity to phase transformation. Applications and precautions, when using the rule of additivity in nucleation incubation, phase transformation, and determination of equilibrium phase-transformation temperature, will be discussed. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008 OI Zhu, Yuntian/0000-0002-5961-7422 NR 40 TC 12 Z9 12 U1 1 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD AUG PY 2000 VL 31 IS 4 BP 675 EP 682 DI 10.1007/s11663-000-0106-z PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 341YF UT WOS:000088618000015 ER PT J AU Dunne, C Moenne-Loccoz, Y de Bruijn, FJ O'Gara, F AF Dunne, C Moenne-Loccoz, Y de Bruijn, FJ O'Gara, F TI Overproduction of an inducible extracellular serine protease improves biological control of Pythium ultimum by Stenotrophomonas maltophilia strain W81 SO MICROBIOLOGY-SGM LA English DT Article DE plant protection; phytopathogenic fungi; bacterial inoculants; serine protease; overproduction ID PSEUDOMONAS-FLUORESCENS F113; PROTEINASE-ENCODING GENE; TRICHODERMA-HARZIANUM; SUGAR-BEET; MOLECULAR MECHANISMS; IMPROVED BIOCONTROL; ECOLOGICAL FITNESS; PLANT-PATHOGENS; DAMPING-OFF; BACTERIA AB Stenotrophomonas maltophilia W81 can protect sugar beet against Pythium-mediated damping-off disease through the production of an extracellular protease, Here, the proteolytic enzyme of W81 was purified by anion-exchangle chromatography and characterized as a serine protease, The purified enzyme was fungicidal against Pythium ultimum in vitro, Its synthesis was inducible by casein in W81, and mutagenesis of this strain using the luciferase (luxAB) reporter transposon Tn5-764cd resulted in the isolation of two mutant derivatives (W81M3 and W81M4) capable of producing significantly increased levels of extracellular protease in the presence of casein, Strain W81M4 also exhibited increased chitinolytic activity. The luxAB fusions in strains W81M3 and W81M4 were highly expressed in the absence of casein but not in its presence, suggesting that the corresponding loci were involved in downregulating extracellular protease production. Extracellular protease production in the W81 wild-type strain and protease overproduction in mutants W81M3 and W81M4 were also induced in the presence of the autoclaved fungal mycelium, In soil microcosms naturally infested by Pythium spp., inoculation of sugar beet seeds with W81M3 or W81M4 resulted in improved biocontrol of Pythium-mediated damping-off disease compared with W81, and the level of protection achieved was equivalent to that conferred by chemical fungicides, The wild-type W81 and its mutant derivatives did not differ in rhizosphere colonization. Therefore, the improved biocontrol ability of W81M3 and W81M4 resulted from their capacity to overproduce extracellular serine protease. C1 Natl Univ Ireland Univ Coll Cork, Dept Microbiol, BIOMERIT Res Ctr, Cork, Ireland. Univ Lyon 1, UMR CNRS, F-69622 Villeurbanne, France. Michigan State Univ, DOE, Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA. RP Natl Univ Ireland Univ Coll Cork, Dept Microbiol, BIOMERIT Res Ctr, Cork, Ireland. EM f.ogara@bureau.ucc.ie NR 54 TC 57 Z9 68 U1 2 U2 4 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND SN 1350-0872 J9 MICROBIOL-SGM JI Microbiology-(UK) PD AUG PY 2000 VL 146 BP 2069 EP 2078 PN 8 PG 10 WC Microbiology SC Microbiology GA 344NC UT WOS:000088764900031 PM 10931911 ER PT J AU Wang, ZL Bentley, J Evans, ND AF Wang, ZL Bentley, J Evans, ND TI Valence state mapping of cobalt and manganese using near-edge fine structures SO MICRON LA English DT Review DE electron energy-loss spectroscopy; transmission electron microscope; transition metal oxides ID ENERGY-LOSS SPECTROSCOPY; TRANSITION-METAL OXIDES; ELECTRON; 3D; NANOCRYSTALS; CONVERSION; FILMS; ELNES AB The properties of transition metal oxides are related to the presence Of elements with mixed valences. The spectroscopy analysis of the valence,states is feasible experimentally, but a spatial mapping of valence states of transition metal elements is a challenge to existing microscopy techniques. In this paper. with the use of valence state information; provided by the white lines and near-edge fine structures observed using the electron energy-loss spectroscopy (EELS) in a transmission electron microscope (TEM), a novel experimental approach is demonstrated to map the valence state distributions of Mn and Co using the ratio of white lines in the energy-filtered TEM. The valence state map is almost independent of specimen thickness in the thickness range adequate for quantitative EELS microanalysis. An optimum spatial resolution of similar to 2 nm has been achieved for a two-phase Co oxides. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Wang, ZL (reprint author), Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. RI Evans, Neal/F-5955-2011; Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 23 TC 42 Z9 43 U1 2 U2 49 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0968-4328 J9 MICRON JI Micron PD AUG PY 2000 VL 31 IS 4 BP 355 EP 362 DI 10.1016/S0968-4328(99)00114-6 PG 8 WC Microscopy SC Microscopy GA 295PJ UT WOS:000085976800005 ER PT J AU Park, CC Bissell, MJ Barcellos-Hoff, MH AF Park, CC Bissell, MJ Barcellos-Hoff, MH TI The influence of the microenvironment on the malignant phenotype SO MOLECULAR MEDICINE TODAY LA English DT Review ID GROWTH-FACTOR-BETA; LEUKEMIA HEMATOPOIETIC PROGENITORS; MARROW STROMA; TRANSGENIC MICE; CELL-GROWTH; MOUSE SKIN; IN-VIVO; CANCER; BREAST; CARCINOGENESIS AB Normal tissue homeostasis is maintained by dynamic interactions between epithelial cells and their microenvironment. As tissue becomes cancerous, there are reciprocal interactions between neoplastic cells, adjacent normal cells such as stroma and endothelium, and their microenvironments. The current dominant paradigm wherein multiple genetic lesions provide bath the impetus for, and the Achilles heel of, cancer might be inadequate to understand cancer as a disease process. In the following brief review, rye will use selected examples to illustrate the influence of the microenvironment in the evolution of the malignant phenotype. We will also discuss recent studies that suggest novel therapeutic interventions might be derived from focusing on microenvironment and tumor cells interactions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Canc & Tissue Biol Life Sci Div, Berkeley, CA 94720 USA. Harvard Univ, Sch Med, Joint Ctr Radiat Therapy, Boston, MA 02115 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Park, CC (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Canc & Tissue Biol Life Sci Div, Bldg 74-174,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI huang, hongqi/N-1473-2014 NR 46 TC 277 Z9 291 U1 2 U2 21 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1357-4310 J9 MOL MED TODAY JI Mol. Med. Today PD AUG PY 2000 VL 6 IS 8 BP 324 EP 329 DI 10.1016/S1357-4310(00)01756-1 PG 8 WC Biochemistry & Molecular Biology; Cell Biology; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; Cell Biology; Research & Experimental Medicine GA 340FY UT WOS:000088523500009 PM 10904250 ER PT J AU Bench, G Corzett, MH Kramer, CE Grant, PG Balhorn, R AF Bench, G Corzett, MH Kramer, CE Grant, PG Balhorn, R TI Zinc is sufficiently abundant within mammalian sperm nuclei to bind stoichiometrically with protamine 2 SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article DE sperm chromatin; single-cell analysis; gel electrophoresis; proton-induced X-ray emission (PIXE) ID MOUSE SPERM; CHROMATIN DECONDENSATION; EJACULATED SPERMATOZOA; PRIMARY SEQUENCE; DNA; PROTEINS; CAPACITY AB Although studies have demonstrated that zinc can bind to sperm nuclear proteins, specifically protamine 2, it has not been shown that the metal is sufficiently abundant inside the sperm nucleus to interact stoichiometrically with these proteins. In this study proton-induced X-ray emission (PIXE) has been used to measure the amount of sulfur and zinc within the nuclei of individual sperm cells to infer the stoichiometry of zinc binding to protamine 2 in six species of mammal: bull, chinchilla, stallion, hamster, human, and mouse (protamine 2 comprises from 0% (bull) to 67% (mouse) of the protamine present in the sperm of these animals). Using the sulfur mass and electrophoretic data on the relative proportion of protamine 1 and protamine 2 in the sperm chromatin of these species, the protamine 1, protamine 2, and total protamine contents within each species sperm nuclei have been determined. The PIXE measurements reveal that the zinc content of the sperm nucleus varies proportionately with the protamine 2 content of sperm chromatin. PIXE analyses of hamster protamines extracted under conditions that appear to at least partially preserve zinc binding also confirm that the majority of the metal is bound to protamine. In five of the species examined, sufficient zinc is present for each protamine 2 molecule to bind one zinc. The results obtained for chinctilla sperm, conversely, indicate the chinchilla protamine 2 molecule may interact differently with zinc. Chinchilla sperm only contain enough zinc for one atom to be bound to two protamine 2 molecules. (C) Published 2000 Wiley-Liss, Inc.(dagger) C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Bench, G (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, L-397, Livermore, CA 94550 USA. NR 37 TC 23 Z9 23 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1040-452X J9 MOL REPROD DEV JI Mol. Reprod. Dev. PD AUG PY 2000 VL 56 IS 4 BP 512 EP 519 DI 10.1002/1098-2795(200008)56:4<512::AID-MRD9>3.0.CO;2-M PG 8 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA 331HQ UT WOS:000088013300009 PM 10911401 ER PT J AU Ginley, DS Bright, C AF Ginley, DS Bright, C TI Transparent conducting oxides SO MRS BULLETIN LA English DT Article ID THIN-FILMS; ELECTRICAL-CONDUCTION; SPINEL; FABRICATION; DEPOSITION; STANNATE; POLYMER; DEVICES; CUALO2; LAYER C1 NREL, Photovoltaics & Elect Mat Div, Golden, CO 80401 USA. RP Ginley, DS (reprint author), NREL, Photovoltaics & Elect Mat Div, SERF W102,15313 Denver W Pkwy, Golden, CO 80401 USA. NR 43 TC 890 Z9 919 U1 14 U2 183 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD AUG PY 2000 VL 25 IS 8 BP 15 EP 18 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 346GH UT WOS:000088862100021 ER PT J AU Coutts, TJ Young, DL Li, XN AF Coutts, TJ Young, DL Li, XN TI Characterization of transparent conducting oxides SO MRS BULLETIN LA English DT Article C1 NREL, Natl Ctr Photovolt, Golden, CO USA. RP Coutts, TJ (reprint author), NREL, Natl Ctr Photovolt, Golden, CO USA. NR 26 TC 270 Z9 282 U1 5 U2 38 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD AUG PY 2000 VL 25 IS 8 BP 58 EP 65 DI 10.1557/mrs2000.152 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 346GH UT WOS:000088862100027 ER PT J AU Huang, X Poy, F Zhang, RG Joachimiak, A Sudol, M Eck, MJ AF Huang, X Poy, F Zhang, RG Joachimiak, A Sudol, M Eck, MJ TI Structure of a WW domain containing fragment of dystrophin in complex with beta-dystroglycan SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID PROLINE-RICH LIGANDS; MAP INTERPRETATION; PROTEIN; BINDING; SH3; RECOGNITION; PEPTIDE AB Dystrophin and beta-dystroglycan are components of the dystrophin-glcoprotein complex (DGC), a multimolecular assembly that spans the cell membrane and links the actin cytoskeleton to the extracellular basal lamina. Defects in the dystrophin gene are the cause of Duchenne and pecker muscular dystrophies. The C-terminal region of dystrophin binds the cytoplasmic tail of beta-dystroglycan, in part through the interaction of its WW domain with a proline-rich moth in the tail of beta-dystroglycan. Here we report the crystal structure of this portion of dystrophin in complex with the proline-rich binding site in beta-dystroglycan. The structure shows that the dystrophin WW domain is embedded in an adjacent helical region that contains two EF-hand-like domains. The beta-dystroglycan peptide binds a composite surface formed by the WW domain and one of these EF-hands. Additionally, the structure reveals striking similarities in the mechanisms of proline recognition employed by WW domains and SH3 domains. C1 Dana Farber Canc Inst, Dept Canc Biol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Boston, MA 02215 USA. Argonne Natl Lab, Struct Biol Ctr, Biosci Div, Argonne, IL 60439 USA. CUNY Mt Sinai Sch Med, Dept Biochem & Mol Biol, New York, NY 10029 USA. RP Eck, MJ (reprint author), Dana Farber Canc Inst, Dept Canc Biol, 44 Binney St, Boston, MA 02115 USA. NR 33 TC 190 Z9 196 U1 2 U2 10 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD AUG PY 2000 VL 7 IS 8 BP 634 EP 638 DI 10.1038/77923 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 340RJ UT WOS:000088548400009 PM 10932245 ER PT J AU Swaminathan, S Eswaramoorthy, S AF Swaminathan, S Eswaramoorthy, S TI Structural analysis of the catalytic and binding sites of Clostridium botulinum neurotoxin B SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID MULTIPLE ISOMORPHOUS REPLACEMENT; BACTERIAL PROTEIN TOXINS; CRYSTAL-STRUCTURE; TETANUS TOXIN; NEUROTRANSMITTER RELEASE; DIPHTHERIA-TOXIN; DIFFRACTION DATA; RESOLUTION; DOMAIN; ZINC AB Clostridium botulinum neurotoxins are among the most potent toxins to humans. The crystal structures of intact C. botulinum neurotoxin type B (BoNT/B) and its complex with sialyllactose, determined at 1.8 and 2.6 Angstrom resolution, respectively, provide insight into its catalytic and binding sites. The position of the belt region in BoNT/B is different from that in BoNT/A; this observation presents interesting possibilities for designing specific inhibitors that could be used to block the activity of this neurotoxin. The structures of BoNT/B and its complex with sialyllactose provide a detailed description of the active site and a model for interactions between the toxin and its cell surface receptor. The latter may provide valuable information for recombinant vaccine development. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Swaminathan, S (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 51 TC 318 Z9 333 U1 3 U2 20 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD AUG PY 2000 VL 7 IS 8 BP 693 EP 699 DI 10.1038/78005 PG 7 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 340RJ UT WOS:000088548400020 PM 10932256 ER PT J AU Letz, R Gerr, F Cragle, D Green, RC Watkins, J Fidler, AT AF Letz, R Gerr, F Cragle, D Green, RC Watkins, J Fidler, AT TI Residual neurologic deficits 30 years after occupational exposure to elemental mercury SO NEUROTOXICOLOGY LA English DT Article DE mercury; epidemiology; neurologic effects; occupational exposures; peripheral neuropathy ID PSYCHOLOGICAL PERFORMANCE; PERIPHERAL NEUROTOXICITY; HAND TREMOR; WORKERS; SENSITIVITY; RELIABILITY; SYSTEM; VAPOR AB A battery of tests of peripheral and central nervous system function was administered to 205 former workers of a large heavy industrial plant, 104 of whom were previously exposed to inorganic mercury. The mean age of those examined was 71 years. Exposed subjects had participated in a urine-mercury exposure monitoring program during the time of operation of a process that required the use of mercury and its subsequent cleanup. Mercury exposure had been high (mean peak urine mercury concentration was >600 mu g/l) and had ended 30 years or more prior to the investigation. Peripheral nerve function outcomes that were statistically significantly associated with cumulative mercury exposure after controlling for covariates included classification as having peripheral neuropathy, peroneal motor nerve conduction velocity, ulnar motor nerve conduction velocity, and peroneal motor nerve F-wave latency. Quantitative assessment of resting tremor was nearly significantly associated with cumulative mercury exposure (p=0.07). Among tests of central nervous system function, results of the Handeye Coordination test were significantly associated with cumulative mercury exposure after controlling for covariates. Cumulative mercury exposure was not observed to be associated with a quantitative measure of dementia or with a number of cognitive neurobehavioral test outcomes. The statistically significant associations with mercury exposure were observed in spite of greater mortality among the exposed group than the unexposed group. These results suggest that substantial occupational mercury exposure can have long-term adverse effects on the peripheral nervous system detectable decades after cessation of exposure. Such long-term adverse effects were not observed for a measure of dementia or other measures of cognitive function. (C) 2000 Intox Press, Inc. C1 Emory Univ, Rollins Sch Publ Hlth, Dept Behav Sci & Hlth Educ, Atlanta, GA 30322 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. Boston Univ, Sch Med, Boston, MA 02215 USA. Boston Univ, Sch Publ Hlth, Boston, MA 02215 USA. US Natl Inst Occupat Safety & Hlth, Cincinnati, OH USA. RP Letz, R (reprint author), Emory Univ, Rollins Sch Publ Hlth, Dept Behav Sci & Hlth Educ, 1518 Clifton Rd NE, Atlanta, GA 30322 USA. FU PHS HHS [200-93-2629] NR 33 TC 36 Z9 38 U1 1 U2 2 PU INTOX PRESS INC PI LITTLE ROCK PA PO BOX 24865, LITTLE ROCK, AR 72221 USA SN 0161-813X J9 NEUROTOXICOLOGY JI Neurotoxicology PD AUG PY 2000 VL 21 IS 4 BP 459 EP 474 PG 16 WC Neurosciences; Pharmacology & Pharmacy; Toxicology SC Neurosciences & Neurology; Pharmacology & Pharmacy; Toxicology GA 358XR UT WOS:000089582900004 PM 11022856 ER PT J AU Middleditch, J Kristian, JA Kunkel, WE Hill, KM Watson, RD Lucinio, R Imamura, JN Steiman-Cameron, TY Shearer, A Butler, R Redfern, M Danks, AC AF Middleditch, J Kristian, JA Kunkel, WE Hill, KM Watson, RD Lucinio, R Imamura, JN Steiman-Cameron, TY Shearer, A Butler, R Redfern, M Danks, AC TI Rapid photometry of supernova 1987A: a 2.14 ms pulsar? SO NEW ASTRONOMY LA English DT Review DE stars : neutron; pulsars : general; pulsars : individual : PSR1987A; supernovae : individual : SN1987A ID LARGE-MAGELLANIC-CLOUD; NEUTRON-STAR SYSTEMS; X-RAY PULSAR; MILLISECOND PULSAR; SN 1987A; OPTICAL PULSATIONS; GLOBULAR-CLUSTERS; GRAVITATIONAL-RADIATION; TELESCOPE OBSERVATIONS; FREE PRECESSION AB We have monitored Supernova 1987A in optical/near-infrared bands using various high-speed photometers from a few weeks following its birth until early 1996 in order to search for a pulsar remnant. While we have found no clear evidence of any pulsar of constant intensity and stable timing, we have found emission with a complex period modulation near the frequency of 467.5 Hz - a 2.14 ms pulsar candidate. We first detected this signal in data taken on the remnant at the Las Campanas Observatory (LCO) 2.5-m Dupont telescope during 14-16 Feb. 1992 UT. We detected further signals near the 2.14 ms period on numerous occasions over the next four years in data taken with a variety of telescopes, data systems and detectors, at a number of ground- and space-based observatories. In particular, an effort during mid-1993 to monitor this signal with the U. of Tasmania 1-m telescope, when SN1987A was inaccessible to nearly all other observing sites due to high airmass, clearly detected the 2.14 ms signal in the first three nights' observations. The sequence of detections of this signal from Feb. '92 through August '93, prior to its apparent subsequent fading, is highly improbable (<10(-10) for any noise source). In addition, the frequency of the signals followed a consistent and predictable spin-down (similar to 2-3 x 10(-10) Hz/s) over the several year timespan ('92-'96). We also find evidence in data, again taken by more than one telescope and recording system, for modulation of the 2.14 ms period with a similar to 1,000 s period which complicates its detection. The 1,000 s modulation was clearly detected in the first two observations with the U. Tas. 1-m during mid-1993. The characteristics of the 2.14 ms signature and its similar to 1,000 s modulation are consistent with precession and spindown via gravitational radiation of a neutron star with an effective non-axisymmetric oblateness of similar to 10(-6). The implied luminosity of the gravitational radiation exceeds the spindown luminosity of the Crab Nebula pulsar by an order of magnitude. Due to the nature of the 2.14 ms signature and its modulation, and the analysis techniques necessary for detection, it is difficult to determine the overall probability that all aspects of the signal are real, though it has remained consistent with an astrophysical origin throughout the several year timespan of our study. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Tasmania, Sch Math & Phys, Hobart, Tas, Australia. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Univ Ireland, Dept Informat Technol, Galway, Ireland. Natl Univ Ireland, Dept Phys, Galway, Ireland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Middleditch, J (reprint author), Univ Calif Los Alamos Natl Lab, CIC-3,MS B256, Los Alamos, NM 87545 USA. RI Butler, Ray/A-6705-2012; Shearer, Andy/N-7609-2014 OI Butler, Ray/0000-0002-8441-7596; Shearer, Andy/0000-0001-7903-0074 NR 117 TC 41 Z9 41 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1092 J9 NEW ASTRON JI New Astron. PD AUG 1 PY 2000 VL 5 IS 5 BP 243 EP 283 DI 10.1016/S1384-1076(00)00024-5 PG 41 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349GA UT WOS:000089034200001 ER PT J AU Gross, CJ Ginter, TN Shapira, D Milner, WT McConnell, JW James, AN Johnson, JW Mas, J Mantica, PF Auble, RL Das, JJ Blankenship, JL Hamilton, JH Robinson, RL Akovali, YA Baktash, C Batchelder, JC Bingham, CR Brinkman, MJ Carter, HK Cunningham, RA Davinson, T Fox, JD Galindo-Uribarri, A Grzywacz, R Liang, JF MacDonald, BD MacKenzie, J Paul, SD Piechaczek, A Radford, DC Ramayya, AV Reviol, W Rudolph, D Rykaczewski, K Toth, KS Weintraub, W Williams, C Woods, PJ Yu, CH Zganjar, EF AF Gross, CJ Ginter, TN Shapira, D Milner, WT McConnell, JW James, AN Johnson, JW Mas, J Mantica, PF Auble, RL Das, JJ Blankenship, JL Hamilton, JH Robinson, RL Akovali, YA Baktash, C Batchelder, JC Bingham, CR Brinkman, MJ Carter, HK Cunningham, RA Davinson, T Fox, JD Galindo-Uribarri, A Grzywacz, R Liang, JF MacDonald, BD MacKenzie, J Paul, SD Piechaczek, A Radford, DC Ramayya, AV Reviol, W Rudolph, D Rykaczewski, K Toth, KS Weintraub, W Williams, C Woods, PJ Yu, CH Zganjar, EF TI Performance of the Recoil Mass Spectrometer and its detector systems at the Holifield Radioactive Ion Beam Facility SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE recoil mass spectrometer; gas detectors; moving tape collector; proton radioactivity; beta decay; gamma spectroscopy ID GAMMA-RAY SPECTROSCOPY; ISOSPIN SYMMETRY; PROTON EMITTERS; EXCITED-STATES; DECAY; IDENTIFICATION; NUCLEI; SEPARATOR; ANALYZER; LU-151 AB The recently commissioned Recoil Mass Spectrometer (RMS) at the Holifield Radioactive Ion Beam Facility (HRIBF) is described. Consisting of a momentum separator followed by an E-D-E Rochester-type mass spectrometer, the RMS is the centerpiece of the nuclear structure endstation at the HRIBF. Designed to transport ions with rigidities near K = 100, the RMS has acceptances of +/- 10% in energy and +/- 4.9% in mass-to-charge ratio. Recent experimental results are used to illustrate the detection capabilities of the RMS, which is compatible with many detectors and devices. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Univ Liverpool, Dept Phys, Liverpool L69 3BX, Merseyside, England. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. CCLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. Univ Edinburgh, Dept Phys, Edinburgh EH9 3JZ, Midlothian, Scotland. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. RP Gross, CJ (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. EM cgross@mail.phy.ornl.gov RI Rudolph, Dirk/D-4259-2009; radford, David/A-3928-2015 OI Rudolph, Dirk/0000-0003-1199-3055; NR 46 TC 124 Z9 124 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 2000 VL 450 IS 1 BP 12 EP 29 DI 10.1016/S0168-9002(00)00159-5 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 341WL UT WOS:000088613900002 ER PT J AU Helmer, RG van der Leun, C AF Helmer, RG van der Leun, C TI Recommended standards for gamma-ray energy calibration (1999) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PRECISION-MEASUREMENTS; AVOGADRO CONSTANT; DECAY; BA-133; REMEASUREMENT; TB-161; EU-152; MASSES AB A consistent set of gamma-ray energies, generally with uncertainties of less than 10 ppm, is recommended for use in the energy calibration of gamma-ray spectra. The energy scale used for the previously recommended standards (1979) has been modified to take into account subsequent adjustments in the fundamental constants ( - 7.71 ppm) and in the gamma-ray wavelengths deduced from a revised estimate of the lattice spacing of Si crystals ( + 1.91 ppm). On this revised energy scale, the strong line from Au-198, the "gold standard", has an energy of 411 802.05 +/- 0.17 eV, which is 2.4 eV (or 5.80 ppm) lower than the 1979 value. A significant improvement has come from the reduction in the uncertainty in the wavelength-to-keV conversion factor from 2.6 to 0.3 ppm. The criteria for the selection of gamma rays to include are described. The list of gamma-ray energies recommended for calibration, especially for Ge semiconductor detectors, has values for about 260 gamma-rays from 50 radionuclides ranging from 24 to 4806 keV. Also, gamma-ray energies are also given for about 70 additional lines, including 5 other radionuclides. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Idaho State Univ, Idaho Accelerator Ctr, Pocatello, ID 83209 USA. RP Helmer, RG (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 54 TC 105 Z9 107 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 2000 VL 450 IS 1 BP 35 EP 70 DI 10.1016/S0168-9002(00)00252-7 PG 36 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 341WL UT WOS:000088613900004 ER PT J AU Sushkov, VV AF Sushkov, VV TI Differential non-linearity compensation in ADCs employing charge redistribution in an array of binary weighted capacitors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE differential non-linearity; charge redistribution technique; analog-to-digital converter AB Differential non-linearity (DNL) compensation in an analog-to-digital converter (ADC) is discussed. The successive approximation ADC under study employs charge redistribution in an array of binary weighted capacitors. The method of DNL compensation is supposed to be implemented in the ADC destined for the tracker readout of the CMS detector at LHC. The parameters of the DNL compensation technique are treated with the constructed simulator built in the Mathematica programming environment. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Sushkov, VV (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 29-100, Berkeley, CA 94720 USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 2000 VL 450 IS 1 BP 119 EP 126 DI 10.1016/S0168-9002(00)00245-X PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 341WL UT WOS:000088613900010 ER PT J AU Selim, FA Hunt, AW Golovchenko, JA Howell, RH Haakenaasen, R Lynn, KG AF Selim, FA Hunt, AW Golovchenko, JA Howell, RH Haakenaasen, R Lynn, KG TI Improved source and transport of monoenergetic MeV positrons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 10th Workshop on Low-Energy Positron and Positronium Physics (Positron Workshop 99) CY JUL 28-31, 1999 CL HIGH ENERGY ACCELERATOR RES ORG, TSUKUBA, JAPAN HO HIGH ENERGY ACCELERATOR RES ORG DE positron beam; beam optics; positron moderator ID SURFACES; ELECTRON; BEAMS AB A new monoenergetic MeV positron beam source was designed and constructed at the Lawrence Livermore National Laboratory (LLNL) positron facility. The positron source provides a low emittance beam with high energy resolution for channeling, scattering, and in-flight annihilation experiments. New beam optics for extracting slow positrons from a moderator mounted in a Pelletron electrostatic accelerator is presented. A beam line was designed and constructed to energy analyze the output of the accelerator and to provide adjustable size and angular divergence beams to a target station. A post target large angle acceptance magnet separates positrons transmitted through the target from forward gamma ray emission. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Rowland Inst Sci Inc, Cambridge, MA 02142 USA. Norwegian Def Res Estab, N-2027 Kjeller, Norway. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. RP Selim, FA (reprint author), Univ Alexandria, Fac Engn, Dept Engn Phys, Alexandria 21544, Egypt. RI Selim, Farida/N-8077-2016 NR 13 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD AUG PY 2000 VL 171 IS 1-2 BP 182 EP 188 DI 10.1016/S0168-583X(00)00082-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 353UQ UT WOS:000089294200021 ER PT J AU Charlton, WS Perry, RT Fearey, BL Parish, TA AF Charlton, WS Perry, RT Fearey, BL Parish, TA TI Calculated actinide and fission product concentration ratios for gaseous effluent monitoring using Monteburns 3.01 SO NUCLEAR TECHNOLOGY LA English DT Article AB Techniques have been developed at Los Alamos National Laboratory for accurately calculating certain spent-fuel isotope concentration ratios for pressurized water reactor assemblies using a linked MCNP/ORIGEN2 code named Monteburns 3.01, without resorting to an assembly or full-core calculation. The effects of various fuel parameters such as the number of radial fuel regions per pin, burnup step size, reactor power, reactivity control mechanisms, and axial profiles have been studied The significance of each factor was determined A method was also proposed for calculating spent-fuel inventories as a function of burnup for a wide range of reactors and fuel types. It was determined that accurate calculations can be obtained using a three-dimensional, modified pin cell with seven radial fuel regions and two (flat-flux) axial fuel regions calculated with 2000 MWd/tonne U burnup steps for burnups ranging from 0 to 50 000 MWd/tonne U. The calculational technique was benchmarked to measured values from the Calvert Cliffs Unit I reactor, and good agreement from the point of view of calibrating a monitoring instrument was found for most cases. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Charlton, WS (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD AUG PY 2000 VL 131 IS 2 BP 210 EP 227 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 335TE UT WOS:000088260200004 ER PT J AU Forsberg, CW AF Forsberg, CW TI Rethinking high-level waste disposal: Separate disposal of high-heat radionuclides (Sr-90 and Cs-137) SO NUCLEAR TECHNOLOGY LA English DT Article ID NUCLEAR AB An alternative approach for disposal of high-level waste (HLW) is proposed. HLW would be separated into two fractions: (a) the high-hear radionuclides (HHRs), e.g., Sr-90 and Cs-137, and (b) the low-heat radionuclides (LHRs), which are all the remaining radionuclides. These two categories of waste would be disposed of separately in different sections of the repository or different facilities. The LHRs in the HLW contain the long-lived radionuclides that control the repository performance requirements that in turn necessitate (a) expensive waste packages (WPs) and (b) limiting the repository temperatures to avoid repository performance degradation. To limit repository temperature, the amount of HLW per WP is limited and the WPs are spread over a large area. If the decay-hear-generating HHRs are removed from HLW the repository design is not controlled by decay heat. The resultant LHR repository size (area, number of WPs, total tunnel length) may be reduced to <20% of the size of a conventional repository. With a waste partitioning and transmutation process that includes removal of the minor actinides (americium and curium) from the LHR wastes, significant further reductions in repository size are possible. The minor actinides are the next largest heat generators in LHR wastes. Separate management of HHRs does require (a) separation of the HHRs from the HLW and (b) a separate HHR disposal facility. The HHRs are disposed of in a separate lower-cost facility made possible by the limited lifetimes (T-1/2 similar to 30 yr) of the HHRs. There are potentially significant gains in economics and repository performance for separate management of HHRs and LHRs in some types of fuel cycles. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Forsberg, CW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 33 TC 19 Z9 19 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD AUG PY 2000 VL 131 IS 2 BP 252 EP 268 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 335TE UT WOS:000088260200007 ER PT J AU Verbeke, JM Chen, AS Vujic, JL Leung, KN AF Verbeke, JM Chen, AS Vujic, JL Leung, KN TI Prediction of in-phantom dose distribution using in-air neutron beam characteristics for boron neutron capture synovectomy SO NUCLEAR TECHNOLOGY LA English DT Article ID RADIATION SYNOVECTOMY AB A monoenergetic neutron beam simulation study was carried out to determine the optimal neutron energy range for treatment of rheumatoid arthritis using radiation synovectomy. The goal of the treatment is the ablation of diseased synovial membranes in joints such as knees and fingers. This study focuses on human knee joints. Two figures of merit are used to measure the neutron beam quality, the ratio of the synovium-absorbed dose to the skin-absorbed dose, and the ratio of the synovium-absorbed dose to the bone-absorbed dose. It was found that (a) thermal neutron beams are optimal for treatment and that (b) similar absorbed dose rates and therapeutic ratios are obtained with monodirectional and isotropic neutron beams. Computation of the dose distribution in a human knee requires the simulation of particle transport from the neutron source to the knee phantom through the moderator. A method was developed to predict the dose distribution in a knee phantom from any neutron and photon beam spectra incident on the knee. This method was revealed to be reasonably accurate and enabled one to reduce the particle transport simulation time by a factor of 10 by modeling the moderator only. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Engn, Berkeley, CA 94720 USA. RP Verbeke, JM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Engn, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD AUG PY 2000 VL 131 IS 2 BP 269 EP 276 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 335TE UT WOS:000088260200008 ER PT J AU Maron, JL Gardner, SN AF Maron, JL Gardner, SN TI Consumer pressure, seed versus safe-site limitation, and plant population dynamics SO OECOLOGIA LA English DT Article DE herbivory; plant population dynamics; seed- versus safe-site-limited recruitment seedbank; simulation model ID INSECT HERBIVORES; FEEDING INSECTS; RECRUITMENT; PREDATION; REPRODUCTION; GRASSLAND; IMPACT; SHRUB; COLONIZATION; DISTURBANCES AB Plants often suffer reductions in fecundity due to insect herbivory. Whether this loss of seeds has population-level consequences is much debated and often unknown. For many plants, particularly those with long-lived seedbanks, it is frequently asserted that herbivores have minimal impacts on plant abundance because safe-site availability rather than absolute seed number determines the magnitude of future plant recruitment and hence population abundance. However, empirical tests of this assertion are generally lacking and the interplay between herbivory, spatio-temporal variability in seed- or safe-site-limited recruitment, and seedbank dynamics is likely to be complex. Here we use a stochastic simulation model to explore how changes in the spatial and temporal frequency of seed-limited recruitment, the strength of density-dependent seedling survival, and longevity of seeds in the soil influence the population response to herbivory. Model output reveals several surprising results. First, given a seedbank, herbivores can have substantial effects on mean population abundance even if recruitment is primarily safe-site-limited in either time or space. Second, increasing seedbank longevity increases the population effects of herbivory, because annual reductions in seed input due to herbivory are accumulated in the seedbank. Third, population impacts of herbivory are robust even in the face of moderately strong density-dependent seedling mortality. These results imply that the conditions under which herbivores influence plant population dynamics may be more widespread than heretofore expected. Experiments are now needed to test these predictions. C1 Univ Washington, Dept Bot, Seattle, WA 98195 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Maron, JL (reprint author), Univ Washington, Dept Bot, Box 355325, Seattle, WA 98195 USA. NR 55 TC 63 Z9 66 U1 1 U2 21 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD AUG PY 2000 VL 124 IS 2 BP 260 EP 269 DI 10.1007/s004420000382 PG 10 WC Ecology SC Environmental Sciences & Ecology GA 345PJ UT WOS:000088824100015 PM 28308187 ER PT J AU Weiss, JD AF Weiss, JD TI Fluorescent optical liquid-level sensor SO OPTICAL ENGINEERING LA English DT Article DE fluorescence radiation; optical liquid-level sensors ID FIBER AB An optical method of detecting a liquid level is presented that uses fluorescence radiation generated in an impurity-doped glass or plastic slab. In operation, the slab is inserted into the liquid and pump light is coupled into it so that the light is guided by the slab-air interface above the liquid and escapes into the liquid just below its surface. Since the fluorescence is generated only in that section of the slab above the liquid, the fluorescence power will monotonically decrease with increasing liquid level. Thus, a relationship can be established between any signal proportional to it and the liquid level. Because optical fibers link the pump source and the detector of fluorescence radiation to the sensor, no electrical connections are needed in or near the liquid. Their absence vastly decreases the hazard associated with placing a liquid-level sensor in a potentially explosive environment. A laboratory prototype, consisting of a methyl styrene slab doped with an organic dye, has been built and successfully tested in water. Its response to liquid level when pumped by a tunable argon-ion laser at 476, 488, and 498 nm, and by a blue LED, is presented and shown to be consistent with theory. The fluorescence spectra, optical efficiency, temperature, and other effects are also presented and discussed. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)02208-X]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Weiss, JD (reprint author), Sandia Natl Labs, Mail Stop 1081,POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 11 Z9 12 U1 0 U2 3 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD AUG PY 2000 VL 39 IS 8 BP 2198 EP 2213 DI 10.1117/1.1305539 PG 16 WC Optics SC Optics GA 344AD UT WOS:000088734700027 ER PT J AU Chang, C Naulleau, P Anderson, E Attwood, D AF Chang, C Naulleau, P Anderson, E Attwood, D TI Spatial coherence characterization of undulator radiation SO OPTICS COMMUNICATIONS LA English DT Article ID SOFT-X-RAY; SYNCHROTRON-RADIATION; LASER AB The coherence properties of undulator radiation at extreme ultraviolet (EW) wavelengths are measured using the Thompson-Wolf two-pinhole method. The effects of asymmetric source size and beamline apertures are observed. High spatial coherence EUV radiation is demonstrated. Projection of these same capabilities to the x-ray region is straightforward. Published by Elsevier Science B.V. C1 Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Chang, C (reprint author), Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. NR 19 TC 39 Z9 39 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD AUG 1 PY 2000 VL 182 IS 1-3 BP 25 EP 34 DI 10.1016/S0030-4018(00)00811-7 PG 10 WC Optics SC Optics GA 343TD UT WOS:000088716900004 ER PT J AU Uran, S Veal, B Grimsditch, M Pearson, J Berger, A AF Uran, S Veal, B Grimsditch, M Pearson, J Berger, A TI Effect of surface roughness on oxidation: Changes in scale thickness, composition, and residual stress SO OXIDATION OF METALS LA English DT Article ID OXIDE SCALES; HIGH-TEMPERATURE; SINGLE-CRYSTALS; ALUMINA; ALLOYS; COATINGS; SAPPHIRE; BEHAVIOR; NICKEL; GROWTH AB The effect of surface roughness on the properties of the oxide scale formed on Fe-Cr-Al alloys during oxidation in air at high temperatures has been investigated Large and systematic differences in scale thickness, in the composition of the oxides forming the scale, and in the residual stess levels are found. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Uran, S (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Berger, Andreas/D-3706-2015 OI Berger, Andreas/0000-0001-5865-6609 NR 34 TC 22 Z9 23 U1 1 U2 5 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD AUG PY 2000 VL 54 IS 1-2 BP 73 EP 85 DI 10.1023/A:1004650612791 PG 13 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 325BG UT WOS:000087656000006 ER PT J AU Cong, G Parvin, B AF Cong, G Parvin, B TI Model-based segmentation of nuclei SO PATTERN RECOGNITION LA English DT Article DE segmentation; grouping; hyperquadric; medical image processing; shape recovery ID 3D AB A new approach for the segmentation of nuclei observed with an epi-fluorescence microscope is presented. The proposed technique is model based and uses local feature activities in the form of step-edge segments, roof-edge segments, and concave corners to construct a set of initial hypotheses. These local feature activities are extracted using either local or global operators and corresponding hypotheses are expressed as hyperquadrics. A neighborhood function is defined over these features to initiate the grouping process. The search space is expressed as an assignment matrix with an appropriate cost function to ensure local and neighborhood consistency. Each possible configuration of nucleus defines a path and the path with least overall error is selected for final segmentation. The system is interactive to allow rapid localization of large numbers of nuclei. The operator then eliminates a small number of false alarms and errors in the segmentation process. (C) 2000 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Informat & Comp Sci Div, Berkeley, CA 94720 USA. RP Cong, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Informat & Comp Sci Div, MS 50B-2239,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM gcong@george.lbl.gov NR 20 TC 25 Z9 27 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0031-3203 EI 1873-5142 J9 PATTERN RECOGN JI Pattern Recognit. PD AUG PY 2000 VL 33 IS 8 BP 1383 EP 1393 DI 10.1016/S0031-3203(99)00119-3 PG 11 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 321WE UT WOS:000087477000009 ER PT J AU Yang, LQ AF Yang, LQ TI Reverse surface segregation in Cu-Pd bimetallic catalysts at low concentrations of Cu SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID CORRECTED EFFECTIVE-MEDIUM; PALLADIUM-COPPER ALLOYS; EMBEDDED-ATOM-METHOD; MOLECULAR-DYNAMICS; SELF-DIFFUSION; FREE-ENERGIES; CLUSTERS; METALS; NI; PREDICTIONS AB This work presents atomic-level simulations that study the surface segregation profiles in Cu-Pd catalysts at various concentrations of Cu. It is found that Cu normally enriches on the surface of 201-atom Cu Pd clusters but depletes from the surface at very low Cu concentrations. This phenomenon was observed in experiments previously and call be reproduced by the molecular dynamics/Monte Carlo-collectcd effective medium theory if the latest modifications, to fit the alloy heats of mixing, are included in the interaction potential. This study also reveals different surface segregation behaviours for clusters having different shapes. It appears that most of the thermally accessible shapes of the cluster exhibit reverse surface segregation. However, these shapes are metastable. The lowest-energy configuration tested, having the cube-octahedral shape, does not show reverse surface segregation; instead, it shows normal surface segregation with Cu enrichment on the surface at all concentrations. Thus, this work suggests that the experimentally observed clusters that demonstrate reverse surface segregation are metastable. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames, IA 50011 USA. RP Yang, LQ (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 36 TC 8 Z9 8 U1 3 U2 9 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD AUG PY 2000 VL 80 IS 8 BP 1879 EP 1888 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 338BE UT WOS:000088397600013 ER PT J AU Frase, HN Fultz, B Roberts, JL Spooner, S AF Frase, HN Fultz, B Roberts, JL Spooner, S TI Structural relaxation within the grain boundaries of nanocrystalline Ni3Fe SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID SMALL-ANGLE SCATTERING; PALLADIUM; SYSTEMS; ALLOYS; LAW AB Results are reported from small-angle neutron scattering (SANS) and Mossbauer spectrometry measurements on four Ni3Fe materials: nanocrystalline material prepared by mechanical attrition, nanocrystalline material after an exposure to 4K, nanocrystalline material after a heat treatment of 100 degrees C for 10 days, and a control sample composed of large crystals. Scattering from the nanocrystalline materials after thermal treatments showed changes in the intensity and the slope of both the nuclear and the magnetic scattering profiles of the SANS measurements. The Mossbauer spectra from the nanocrystalline samples showed changes in the hyperfine fields associated with grain-boundary atoms. The changes induced by cryogenic exposure and annealing at 100 degrees C were somewhat different but were consistent with a sharper density gradient between the crystalline region and the grain-boundary region. Some grain-boundary atoms in mechanically attrited Ni3Fe are in energetically unfavourable positions, and move into new positions during these low-temperature treatments. C1 CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Frase, HN (reprint author), CALTECH, Div Engn & Appl Sci, Mail 138-78, Pasadena, CA 91125 USA. NR 22 TC 5 Z9 5 U1 3 U2 7 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD AUG PY 2000 VL 80 IS 8 BP 1545 EP 1554 DI 10.1080/13642810008208583 PG 10 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 338BF UT WOS:000088397700007 ER PT J AU Manley, ME McQueeney, RJ Robertson, JL Fultz, B Neumann, DA AF Manley, ME McQueeney, RJ Robertson, JL Fultz, B Neumann, DA TI Phonon densities of states of gamma-cerium and delta-cerium measured by time-of-flight inelastic neutron scattering SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID VIBRATIONAL ENTROPY; ELECTRONIC-STRUCTURE; DISORDERED NI3AL; CE; APPROXIMATION; PRESSURE; ALLOYS AB Time-of-flight inelastic neutron scattering spectra were measured on cerium metal at temperatures near. the fee (gamma)-to-bcc (delta) transition temperature. Phonon density-of-slates (DOS) curves were extracted from data acquired over a wide range of momentum transfers. A large softening of the phonon DOS was found in going from gamma-cerium to delta-cerium, and this accounts for an increase in vibrational entropy of (0.71 +/- 0.05)k(B)/atom. To be consistent with the latent heat of the gamma-delta transition, this increase in vibrational entropy must be accompanied by a large decrease in electronic entropy. The results not only confirm the recent discovery of a significant electronic contribution to the gamma-delta transition but also suggest that it may be twice that previously reported. C1 CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Manley, ME (reprint author), CALTECH, MS 138-78, Pasadena, CA 91125 USA. RI Manley, Michael/N-4334-2015; McQueeney, Robert/A-2864-2016 OI McQueeney, Robert/0000-0003-0718-5602 NR 23 TC 12 Z9 13 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD AUG PY 2000 VL 80 IS 8 BP 591 EP 596 DI 10.1080/09500830050110530 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 343HQ UT WOS:000088697300011 ER PT J AU Sonier, JE Heffner, RH MacLaughlin, DE Smith, JL Cooley, J Nieuwenhuys, GJ AF Sonier, JE Heffner, RH MacLaughlin, DE Smith, JL Cooley, J Nieuwenhuys, GJ TI Anomalous Knight shift in the superconducting state of UBe13 SO PHYSICA B LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE heavy-fermion compounds; superconductivity; mu(+) Knight shift AB We report muon spin rotation measurements of the temperature dependence of the mu(+)-Knight shift in single crystals of UBe13. The dipolar fields produced by the uranium Sf-electron moments result in two magnetically inequivalent mu(+) sites. Below T-c, the magnitude of the Knight shift is observed to decrease with decreasing T at one of the sites, whereas it is found to increase at the other site. The data is explained by an effective exchange interaction between the mu(+) and the 5f-electrons which is temperature dependent and anisotropic below T approximate to 6 K. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. RP Sonier, JE (reprint author), Univ Calif Los Alamos Natl Lab, MST-10 MS K764, Los Alamos, NM 87545 USA. RI Cooley, Jason/E-4163-2013 NR 6 TC 6 Z9 6 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 20 EP 23 DI 10.1016/S0921-4526(00)00234-9 PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500008 ER PT J AU Heffner, RH Sonier, J MacLaughlin, DE Nieuwenhuys, GJ Uemura, YJ Luke, GM Cheong, SW AF Heffner, RH Sonier, J MacLaughlin, DE Nieuwenhuys, GJ Uemura, YJ Luke, GM Cheong, SW TI Evidence for a distributed ferromagnetic transition in (La,Ca)MnO3 SO PHYSICA B LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE ferromagnetism; manganites; polarons ID LA1-XCAXMNO3; MAGNETISM; DYNAMICS AB We report new zero-field mu SR measurements in ferromagnetic (FM) (La,Ca)MnO3 which are consistent with two spatially separated regions in close proximity possessing very different Mn-ion spin dynamics. We present a picture in which one region corresponds to an extended spin polaron which displays a peak in the relaxation rate near the Curie temperature T-c and an increasing volume fraction below T-c. The second region possesses slower fluctuating spins and a decreasing volume fraction below T-c. These data suggest a microscopically inhomogeneous FM phase transition resulting From the overlap of spin polarons. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. Columbia Univ, Dept Phys, New York, NY 10027 USA. McMaster Univ, Hamilton, ON L8P 4N1, Canada. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. RP Heffner, RH (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS K764,MST-10, Los Alamos, NM 87545 USA. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 13 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 61 EP 64 DI 10.1016/S0921-4526(00)00256-8 PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500018 ER PT J AU Nieuwenhuys, GJ Patil, NG Noijons, H Tomuta, DG MacLaughlin, DE Heffner, RH Amato, A AF Nieuwenhuys, GJ Patil, NG Noijons, H Tomuta, DG MacLaughlin, DE Heffner, RH Amato, A TI Determination of the muon site in URh2Ge2 SO PHYSICA B LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE magnetism; spin glass; stopping site ID UPT2SI2 AB As-grown single crystals of the compound URh2Ge2 have been shown by tnagnetic and mu SR measurements to exhibit a spin-glass ground state below a temperature of 10 K. The rapid decay of the muon polarization below the freezing temperature was found to be isotropic, whereas anisotropic relaxation may be expected (depending on the muon site) if the U-ion magnetic moment were aligned along the c-axis. We measured the dependence of transverse-field muon shifts and line widths on temperature and magnetic field orientation. Based on our results, the muon site is (1/2,0,0.1). Simulations of the muon decay signal for random and Ising (c-axis aligned) spin-glass states indicate that the Ising case should have led to anisotropic behaviour of the decay. The experimentally observed isotropic polarization decay thus strongly suggests a random anisotropy for U moments in UR2Ge2. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. RP Nieuwenhuys, GJ (reprint author), Leiden Univ, Kamerlingh Onnes Lab, POB 9504, NL-2300 RA Leiden, Netherlands. RI Amato, Alex/H-7674-2013 OI Amato, Alex/0000-0001-9963-7498 NR 13 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 228 EP 231 DI 10.1016/S0921-4526(00)00374-4 PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500058 ER PT J AU Luke, GM Fudamoto, Y Kojima, KM Larkin, MI Nachumi, B Uemura, YJ Sonier, JE Maeno, Y Mao, ZQ Mori, Y Agterberg, DF AF Luke, GM Fudamoto, Y Kojima, KM Larkin, MI Nachumi, B Uemura, YJ Sonier, JE Maeno, Y Mao, ZQ Mori, Y Agterberg, DF TI Unconventional superconductivity in Sr2RuO4 SO PHYSICA B LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE superconductivity; p-wave; Sr2RuO4 ID VORTEX LATTICE AB We have performed ZF-mu SR measurements of Sr2RuO4 and have observed a spontaneous magnetic field below T-c. This observation, combined with other symmetry considerations demonstrates that superconductivity in Sr2RuO4 is of 'p-wave' (odd-parity) type. Our transverse field mu SR measurements in the mixed state with B = 150 G parallel to (c) over cap clearly indicate the presence of a square flux lattice. We have analysed the field distribution in terms of the penetration depth, coherence length and a Fermi surface anisotropy term and found lambda(T = 0) = 1900 Angstrom. lambda(T --> 0) is quite flat, consistent with a superconducting gap with no nodes as expected for the E-u (k(x) +/- ik(y)) state. (C) 2000 Elsevier Science B.V. All rights reserved. C1 McMaster Univ, Brockhouse Inst Mat Res, Hamilton, ON L8S 4M1, Canada. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Columbia Univ, Dept Phys, New York, NY 10027 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. Florida State Univ, NHMFL, Tallahassee, FL 32310 USA. RP Luke, GM (reprint author), McMaster Univ, Brockhouse Inst Mat Res, Hamilton, ON L8S 4M1, Canada. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 10 TC 26 Z9 26 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 373 EP 376 DI 10.1016/S0921-4526(00)00414-2 PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500096 ER PT J AU Ohishi, K Akimitsu, J Higemoto, W Kadono, R Miller, RI Price, A Kiefl, RF Sonier, JE Nohara, M Suzuki, H Takagi, H AF Ohishi, K Akimitsu, J Higemoto, W Kadono, R Miller, RI Price, A Kiefl, RF Sonier, JE Nohara, M Suzuki, H Takagi, H TI Anomalous field dependence of the vortex-core radius and magnetic penetration depth in YNi2B2C probed by mu SR SO PHYSICA B LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE vortex state; penetration depth; coherence length; YNi2B2C ID SPIN ROTATION; SUPERCONDUCTORS; STATE; DENSITY; CERU2 AB Muon spin rotation measurements were performed to deduce the magnetic penetratioin depth lambda and vortex core radius rho(v) in the mixed state of YNi2B2C for H-c1 much less than H less than or equal to 0.7 H-c2. A preliminary analysis based on the modified London model shows that rho(v) decreases steeply with increasing H, while lambda increases linearly in H. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 1578572, Japan. KEK, High Energy Accelerator Res Org, Inst Mat Struct Sci, Tsukuba, Ibaraki 3050801, Japan. Univ British Columbia, TRIUMF, Vancouver, BC V6T 1Z1, Canada. Univ British Columbia, Dept Phys, Vancouver, BC V6T 1Z1, Canada. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Tokyo, Inst Solid State Phys, Minato Ku, Tokyo 1068666, Japan. RP Ohishi, K (reprint author), Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, 6-16-1 Chitosedai, Tokyo 1578572, Japan. RI Takagi, Hidenori/B-2935-2010; Ohishi, Kazuki/E-9592-2010; NOHARA, Minoru/B-1476-2011 OI Ohishi, Kazuki/0000-0003-1494-6502; NR 11 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 377 EP 380 DI 10.1016/S0921-4526(00)00415-4 PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500097 ER PT J AU Uemura, YJ Fudamoto, Y Gat, IM Larkin, MI Luke, GM Merrin, J Kojima, KM Itoh, K Yamanaka, S Heffner, RH MacLaughlin, DE AF Uemura, YJ Fudamoto, Y Gat, IM Larkin, MI Luke, GM Merrin, J Kojima, KM Itoh, K Yamanaka, S Heffner, RH MacLaughlin, DE TI mu SR studies of intercalated HfNCl superconductor SO PHYSICA B LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE superconductivity; penetration depth; HfNCl ID MAGNETIC PENETRATION DEPTH; SPIN-RELAXATION; DENSITY; NITRIDE; CUPRATE; PHASE AB Muon spin relaxation measurements of the magnetic field penetration depth lambda have been performed in a quasi two-dimensional (2-d) superconductor based on HfNCl intercalated with Li and organic molecules. The relaxation rate sigma(T --> 0) similar to 0.5 mu s(-1) was obtained with transverse fields applied perpendicular to the aligned HfN planes. Using the relation sigma proportional to lambda(-2) proportional to n(s2d)/m* (2-d superconducting carrier density/effective mass), we deduced the 2-d Fermi temperature T-F2d. The ratio Tc/T-F2d for the HfNCl-(Li) system is very close to those in two other quasi-2-d superconductors, YBa2Cu3O7 and (BEDT-TTF)(2)-X. Compared to the Kosterlitz-Thouless (KT) transition temperature T-KT = T-F2d/8 for the limit of strong coupling, T-c's of these systems are reduced by a factor of 3-4, indicating the importance of carrier overlapping and/or 3-d coupling. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Hiroshima Univ, Dept Appl Chem, Higashihiroshima 739, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. RP Uemura, YJ (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 18 TC 41 Z9 41 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 389 EP 392 DI 10.1016/S0921-4526(00)00418-X PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500100 ER PT J AU MacLaughlin, DE Heffner, RH Sonier, JE Nieuwenhuys, GJ Chau, R Maple, MB Andraka, B Luke, GM Fudamoto, Y Uemura, YJ Amato, A Baines, C AF MacLaughlin, DE Heffner, RH Sonier, JE Nieuwenhuys, GJ Chau, R Maple, MB Andraka, B Luke, GM Fudamoto, Y Uemura, YJ Amato, A Baines, C TI Muon spill rotation and non-Fermi liquid behavior in UCu4Pd SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE non-Fermi liquid; UCu5-xPdx; Kondo disorder; Griffiths phase ID KONDO DISORDER; UCU5-XPDX; SR; CECU5.9AU0.1; SYSTEMS; NMR AB Muon spin rotation and relaxation (mu SR) experiments have been carried out on the non-Fermi liquid (NFL) heavy-fermion compound UCu4Pd. Transverse-field mu SR line widths indicate that the U-ion susceptibility is inhomogeneous and in good agreement with predictions of disorder-driven NFL mechanisms. The inhomogeneity seems to be remarkably independent of the exact amount of structural disorder. Longitudinal-field experiments yield muon spin-lattice relaxation rates which are two orders of magnitude faster than estimates from a single-ion 'Kondo disorder' model. This suggests a cooperative rather than a single-ion NFL mechanism. No evidence is found for freezing of more than a few percent of U-ion moments in UCu4Pd above 100 mK. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8P 4N1, Canada. Columbia Univ, Dept Phys, New York, NY 10027 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. RP Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. EM macl@citrus.ucr.edu RI Luke, Graeme/A-9094-2010; Amato, Alex/H-7674-2013; OI Amato, Alex/0000-0001-9963-7498; Luke, Graeme/0000-0003-4762-1173 NR 17 TC 6 Z9 6 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 15 EP 18 DI 10.1016/S0921-4526(00)00233-7 PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500006 ER PT J AU Cox, SJF Cottrell, SP Charlton, M Donnelly, PA Blundell, SJ Smith, JL Cooley, JC AF Cox, SJF Cottrell, SP Charlton, M Donnelly, PA Blundell, SJ Smith, JL Cooley, JC TI Muon Korringa relaxation SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 8th International Conference on Muon Spin Rotation, Relaxation and Resonance CY AUG 30-SEP 03, 1999 CL LES DIABLERETS, SWITZERLAND SP European Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG & G Berthold GmbH & Co KG, Prophysik AG, Kroger & Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil & Motoren AG DE semimetals; muonium; Korringa relaxation; molecular radicals AB Significant muon spin-lattice relaxation is found in a number of non-magnetic semimetals and metals. Measured in longitudinal magnetic field, the relaxation rate is independent of field up to several kilogauss and generally increases monotonically with temperature. This suggests a form of Korringa relaxation, originating in the hyperfine interaction between the implanted muons and the conduction electrons. Bearing in mind that NMR data on Korringa relaxation refers chiefly to the host nuclei, the muon offers a probe of conduction-electron encounter at an interstitial site, linking the topic to the nature of defect screening in metals, to relaxation by spin-density fluctuations in magnetic materials and to spin- and charge-exchange on paramagnetic muonium centres in semiconductors. Data are presented for C (graphite), Bi, Pb and Cd and compared with the Korringa predictions using known values of the muon Knight shift. Control experiments are described on Zn and Cu, both pure and deliberately doped with magnetic impurity. For graphite, an interpretation is given in terms of charge-exchange on a molecular radical formed by the chemical reaction of interstitial muonium. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Rutherford Appleton Lab, ISIS Facil, Chilton OX11 0QX, Oxon, England. UCL, Dept Phys & Astron, London WC1E 6BT, England. Univ Oxford, Clarendon Lab, Oxford OX1 2JD, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rutherford Appleton Lab, ISIS Facil, Chilton OX11 0QX, Oxon, England. RI Cooley, Jason/E-4163-2013 NR 12 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD AUG PY 2000 VL 289 BP 594 EP 597 DI 10.1016/S0921-4526(00)00288-X PG 4 WC Physics, Condensed Matter SC Physics GA 330GB UT WOS:000087953500154 ER PT J AU Neill, PA Trabert, E Beiersdorfer, P Brown, GV Harris, CL Utter, SB Wong, KL AF Neill, PA Trabert, E Beiersdorfer, P Brown, GV Harris, CL Utter, SB Wong, KL TI Improved electron-beam ion-trap lifetime measurement of the 1s2s S-3(1) level in N5+ and F7+ SO PHYSICA SCRIPTA LA English DT Article ID DIPOLE TRANSITIONS; N=2 STATES; ENERGY; DECAY; ATOMS AB Earlier measurements using a heavy-ion storage ring and an electron beam ion trap (EBIT) for the determination of the N5+ 1s2s S-3(1) level lifetime are improved upon by new EBIT work. The new result, 3.94 +/- 0.05 ms, agrees with the previous values. but is more precise. A corresponding measurement on F7+ yields a lifetime of 276 +/- 2 mu s The new values corroborate the isoelectronic trend of the most precise data for this isoelectronic sequence and thus help distinguish among theoretical predictions. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94551 USA. RP Neill, PA (reprint author), Univ Nevada, Dept Phys, Reno, NV 89557 USA. NR 20 TC 16 Z9 16 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD AUG-SEP PY 2000 VL 62 IS 2-3 BP 141 EP 144 DI 10.1238/Physica.Regular.062a00141 PG 4 WC Physics, Multidisciplinary SC Physics GA 346ZZ UT WOS:000088902900009 ER PT J AU Cohen, JS AF Cohen, JS TI Multielectron effects in capture of antiprotons and muons by helium and neon SO PHYSICAL REVIEW A LA English DT Article ID EFFECTIVE HAMILTONIAN-STRUCTURE; FERMION MOLECULAR-DYNAMICS; COULOMB-CAPTURE; X-RAYS; SEMICLASSICAL DESCRIPTION; CONCENTRATION-DEPENDENCE; METASTABLE STATES; NOBLE-GASES; ATOMS; HYDROGEN AB Antiproton ((p) over bar) and negative muon (mu(-)) captures by helium and neon atoms are treated using the fermion-molecular-dynamics method, yielding capture cross sections, initial quantum numbers, and ejected-electron energies. The calculated angular-momentum distributions tend to pile up at l = n - 1 and are not well fitted by the form (21 + 1)e(alpha l), which is often assumed in experimental analyses. The residual electrons are generally left in a "shake-up" state. When capture is accompanied by multiple ionization, the second and later electrons escape with increasing kinetic energies, a process that is not well described as quasiadiabatic. In a 50:50 mixture of helium and neon, the calculated Ne:He capture ratios are 3.36 for (p) over bar and 3.69 for mu(-). The mu(-) per-atom capture probability is almost independent of the neon fraction and is in overall agreement with several mu(-) and pi(-) experiments; for (p) over bar then is a rather strong dependence on neon fraction, but there are as yet no experiments. The possible experimental indication of a strong isotope effect on capture of pi(-) in mixtures of He-3 and He-4 is not supported by the present calculation. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM cohen@lanl.gov NR 58 TC 36 Z9 36 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 022512 DI 10.1103/PhysRevA.62.022512 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400050 ER PT J AU Katsnelson, MI Dobrovitski, VV Harmon, BN AF Katsnelson, MI Dobrovitski, VV Harmon, BN TI Propagation of local decohering action in distributed quantum systems SO PHYSICAL REVIEW A LA English DT Article ID INTERFERENCE; HISTORIES; COMPUTER; DYNAMICS; PHASE AB We study propagation of the decohering influence caused by a local measurement performed on a distributed quantum system. As an example, the gas of bosons forming a Bose-Einstein condensate is considered. We demonstrate that the local decohering perturbation exerted on the measured region propagates over the system in the form of a decoherence wave, whose dynamics is governed by elementary excitations of the system. We argue that the post-measurement evolution of the system (determined by elementary excitations) is of importance for transfer of decoherence, while the initial collapse of the wave function has negligible impact on the regions that are not directly affected by the measurement. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Russian Acad Sci, Inst Met Phys, Ekaterinburg 620219, Russia. RP Katsnelson, MI (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Katsnelson, Mikhail/D-4359-2012 NR 30 TC 8 Z9 8 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 022118 DI 10.1103/PhysRevA.62.022118 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400025 ER PT J AU Nortershauser, W Bushaw, BA Blaum, K AF Nortershauser, W Bushaw, BA Blaum, K TI Double-resonance measurements of isotope shifts and hyperfine structure in GdI with hyperfine-state selection in an intermediate level SO PHYSICAL REVIEW A LA English DT Article ID IONIZATION; SPECTROSCOPY; TERM AB Isotope shifts and hyperfine structure have been measured in the 4f(7)5d6s(2) D-9(6)-->X D-9(6) (38 024.792 cm(-1)) transition in atomic gadolinium using high-resolution resonance ionization mass spectroscopy. Excitation was performed as a resonance-enhanced two-photon transition with the 4f(7)5d6s6p F-9(7) State as an intermediate level. Selective population of hyperfine states in the first excitation step allowed assignment of all transitions in the complex hyperfine spectrum of the odd isotopes Gd-155,Gd-157 and evaluation of the magnetic dipole and electric quadrupole hyperfine structure constants for the X D-9(6) state. Measured values for the isotope shifts of all stable Gd isotopes have been used to derive specific mass-shift and field-shift factors. The obtained spectroscopic information leads to the conclusion that the X D-9(6) State is a 4f(7)5d6s8s configuration. C1 Pacific NW Lab, Richland, WA 99352 USA. Univ Mainz, Inst Phys, D-55099 Mainz, Germany. RP Nortershauser, W (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. RI Nortershauser, Wilfried/A-6671-2013 OI Nortershauser, Wilfried/0000-0001-7432-3687 NR 21 TC 11 Z9 11 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 022506 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400044 ER PT J AU Segev, B Milonni, PW Babb, JF Chiao, RY AF Segev, B Milonni, PW Babb, JF Chiao, RY TI Quantum noise and superluminal propagation SO PHYSICAL REVIEW A LA English DT Article ID INFORMATION-TRANSFER; OPTICAL PULSES; SUPERFLUORESCENCE; MEDIA; AMPLIFIERS; LIGHT; DELAY AB Causal "superluminal" effects have recently been observed and discussed in various contexts. The question arises whether such effects could be observed with extremely weak pulses, and what would prevent the observation of an "optical tachyon." Aharonov, Reznik, and Stern (ARS) [Phys. Rev. Lett. 81, 2190 (1998)] have argued that quantum noise will preclude the observation of a superluminal group velocity when the pulse consists of one or a few photons. In this paper we reconsider this question both in a general framework and in the specific example, suggested by Chiao, Kozhekin, and Kurizki (CKK) [Phys. Rev. 77, 1254 (1996)], of off-resonant, short-pulse propagation in an optical amplifier. We derive in the case of the amplifier a signal-to-noise ratio that is consistent with the general ARS conclusions when we impose their criteria for distinguishing between superluminal propagation and propagation at the speed c. However, results consistent with the semiclassical arguments of CKK an obtained if weaker criteria are imposed, in which case the signal can exceed the noise without being "exponentially large." We show that the quantum fluctuations of the field considered by ARS are closely related to superfluorescence noise. More generally, we consider the implications of unitarity for superluminal propagation and quantum noise and study, in addition to the complete and truncated wave packets considered by ARS, the residual wave packet formed by their difference. This leads to the conclusion that the noise is mostly luminal and delayed with respect to the superluminal signal. In the limit of a very weak incident signal pulse, the superluminal signal will be dominated by the noise part, and the signal-to-noise ratio will therefore be very small. C1 Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Univ Calif Los Alamos Natl Lab, Theoret Div T 4, Los Alamos, NM 87545 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Segev, B (reprint author), Ben Gurion Univ Negev, Dept Chem, POB 653, IL-84105 Beer Sheva, Israel. NR 19 TC 15 Z9 15 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 022114 DI 10.1103/PhysRevA.62.022114 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400021 ER PT J AU Yoshida, S Reinhold, CO Kristofel, P Burgdorfer, J AF Yoshida, S Reinhold, CO Kristofel, P Burgdorfer, J TI Exponential and nonexponential localization of the one-dimensional periodically kicked Rydberg atom SO PHYSICAL REVIEW A LA English DT Article ID EXCITED HYDROGEN-ATOMS; HALF-CYCLE PULSES; DYNAMICAL STABILIZATION; IONIZATION; REALIZATION; CHAOS AB We investigate the quantum localization of the one-dimensional Rydberg atom subject to a unidirectional periodic train of impulses. For high frequencies of the train the classical system becomes chaotic and leads to fast ionization. By contrast, the quantum system is found to be remarkably stable. We identify for this system the coexistence of different localization mechanisms associated with resonant and nonresonant diffusion. We find for the suppression of nonresonant diffusion an exponential localization whose localization length can be related to the classical dynamics in terms of the "scars" of the unstable periodic orbits. We show that the localization length is determined by the energy excursion along the periodic orbits. The suppression of resonant diffusion along the sequence of photonic peaks is found to be nonexponential due to the presence of high harmonics in the driving force. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Vienna Univ Technol, Inst Theoret Phys, A-1040 Vienna, Austria. RP Yoshida, S (reprint author), Max Planck Inst Phys Komplexer Syst, D-01187 Dresden, Germany. NR 25 TC 22 Z9 22 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 023408 DI 10.1103/PhysRevA.62.023408 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400082 ER PT J AU Chesnut, GN Vohra, YK AF Chesnut, GN Vohra, YK TI Phase transformations and equation of state of praseodymium metal to 103 GPa SO PHYSICAL REVIEW B LA English DT Article ID HIGH-PRESSURE PHASE; CERIUM; TRANSITION AB Pressure-induced structural phase transformations in a trivalent rare-earth metal praseodymium (Pr) were studied at room temperature in a diamond anvil cell to 103 GPa by energy dispersive x-ray diffraction using a synchrotron source. Our x-ray diffraction studies document the following crystal structure sequence: dhcp-->fcc-->distorted fcc(hR24 type)-->alpha-monoclinic(C2/m)-->alpha-uranium with increasing pressure. We measure a 16.7% volume collapse at the transition to the alpha-uranium phase at 20 GPa. The high-pressure alpha-uranium phase in Pr was found to be stable to the highest pressure of 103 GPa, which corresponds to a volume compression V/V-0=0.407. C1 Univ Alabama, Dept Phys, Birmingham, AL 35294 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Chesnut, GN (reprint author), Univ Alabama, Dept Phys, Birmingham, AL 35294 USA. NR 19 TC 31 Z9 31 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 AUG 1 PY 2000 VL 62 IS 5 BP 2965 EP 2968 DI 10.1103/PhysRevB.62.2965 PG 4 WC Physics, Condensed Matter SC Physics GA 343QZ UT WOS:000088714200001 ER PT J AU Kim, SK Koo, YM Chernov, VA Kortright, JB Shin, SC AF Kim, SK Koo, YM Chernov, VA Kortright, JB Shin, SC TI Comparison of atomic structure anisotropy between Co-Pd alloys and Co/Pd multilayer films SO PHYSICAL REVIEW B LA English DT Article ID PERPENDICULAR MAGNETIC-ANISOTROPY; ABSORPTION FINE-STRUCTURE; EPITAXIAL-GROWTH; MOUND MORPHOLOGY; THIN-FILMS; INTERFACE; SUPERLATTICES; MECHANISM; EVOLUTION AB We have employed Co K-edge extended x-ray absorption fine structure measurements with linear polarization dependence to investigate the chemical short-range order (SRO) and interatomic distance anisotropy in CoxPd1-x alloy (X = 0.16, 0.31) and [Co(2 Angstrom)/Pd(Y Angstrom)](13) multilayer films (Y = 15, 32). The SRO parameters of in-plane first nearest neighbors, 0.063-0.068 in the alloys and 0.012-0.036 in the multilayers, are observed. Surprisingly, these counterintuitive results show clear evidence that the Co atoms at the Co/Pd interfaces in multilayers have more alloylike characteristic than those in alloys with respect to local chemical environment. C1 Korea Adv Inst Sci & Technol, Dept Phys, Taejon 305701, South Korea. Korea Adv Inst Sci & Technol, Ctr Nanospin Spintron Mat, Taejon 305701, South Korea. POSTECH, Dept Mat Sci & Engn, Pohang 790784, South Korea. Budker Inst Nucl Phys, Inst Catalysis, Siberian Synchrotron Radiat Ctr, Novosibirsk 630090, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Kim, SK (reprint author), Korea Adv Inst Sci & Technol, Dept Phys, Taejon 305701, South Korea. RI Shin, Sung-Chul/C-1992-2011; Kim, Sang-Koog/J-4638-2014 NR 32 TC 14 Z9 14 U1 1 U2 8 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 AUG 1 PY 2000 VL 62 IS 5 BP 3025 EP 3028 DI 10.1103/PhysRevB.62.3025 PG 4 WC Physics, Condensed Matter SC Physics GA 343QZ UT WOS:000088714200017 ER PT J AU Lu, G Kioussis, N Bulatov, VV Kaxiras, E AF Lu, G Kioussis, N Bulatov, VV Kaxiras, E TI Generalized-stacking-fault energy surface and dislocation properties of aluminum SO PHYSICAL REVIEW B LA English DT Article ID PEIERLS-NABARRO MODEL; FIRST-PRINCIPLES; CORE; SIMULATIONS; NUCLEATION; BARRIERS; BEHAVIOR; SILICON; METALS; CRACK AB We have employed the semidiscrete variational generalized Peierls-Nabarro model to study the dislocation properties of aluminum. The generalized-stacking-fault (GSF) energy surface entering the model is calculated by using first-principles density functional theory (DFT) and the embedded-atom method (EAM). Various core properties, including the core width, dissociation behavior, energetics, and Peierls stress for different dislocations have been investigated. The correlation between the core energetics and the Peierls stress with the dislocation character has been explored. Our results reveal a simple relationship between the Peierls stress and the ratio between the core width and the atomic spacing. The dependence of the core properties on the two methods for calculating the GSF energy (DFT vs EAM) has been examined. Although the EAM gives the general trend for various dislocation properties, it fails to predict the correct finer core structure, which in turn can affect the Peierls stress significantly (about one order of magnitude). C1 Calif State Univ Northridge, Dept Phys, Northridge, CA 91330 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. RP Calif State Univ Northridge, Dept Phys, Northridge, CA 91330 USA. NR 31 TC 153 Z9 156 U1 8 U2 66 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 AUG 1 PY 2000 VL 62 IS 5 BP 3099 EP 3108 DI 10.1103/PhysRevB.62.3099 PG 10 WC Physics, Condensed Matter SC Physics GA 343QZ UT WOS:000088714200033 ER PT J AU Aligia, AA Batista, CD Essler, FHL AF Aligia, AA Batista, CD Essler, FHL TI Numerical method for detecting incommensurate correlations in the Heisenberg zigzag ladder SO PHYSICAL REVIEW B LA English DT Article ID SPIN CORRELATIONS; CHAIN; SRCUO2 AB We study two Heisenberg spin-1/2 chains coupled by a frustrating ''zigzag'' interaction. We are particularly interested in the regime of weak interchain coupling, which is difficult to analyze by either numerical or analytical methods. Previous density matrix renormalization-group studies of the isotropic model with open boundary conditions and sizable interchain coupling have established the presence of incommensurate correlations and of a spectral gap. By using twisted boundary conditions with an arbitrary twist angle, we are able to determine the incommensurabilities both in the isotropic case and in the presence of an exchange anisotropy by means of exact diagonalization of relatively short finite chains of up to 24 sites. Using twisted boundary conditions results in a very smooth dependence of the incommensurabilities on system size, which makes the extrapolation to infinite systems significantly easier than for open or periodic chains. C1 Ctr Atom Bariloche, Comis Nacl Energia Atom, RA-8400 Bariloche, Rio Negro, Argentina. Inst Balseiro, RA-8400 Bariloche, Rio Negro, Argentina. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RP Aligia, AA (reprint author), Ctr Atom Bariloche, Comis Nacl Energia Atom, RA-8400 Bariloche, Rio Negro, Argentina. RI Batista, Cristian/J-8008-2016 NR 18 TC 50 Z9 50 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 AUG 1 PY 2000 VL 62 IS 5 BP 3259 EP 3263 DI 10.1103/PhysRevB.62.3259 PG 5 WC Physics, Condensed Matter SC Physics GA 343QZ UT WOS:000088714200055 ER PT J AU Cyrille, MC Kim, S Gomez, ME Santamaria, J Krishnan, KM Schuller, IK AF Cyrille, MC Kim, S Gomez, ME Santamaria, J Krishnan, KM Schuller, IK TI Enhancement of perpendicular and parallel giant magnetoresistance with the number of bilayers in Fe/Cr superlattices SO PHYSICAL REVIEW B LA English DT Article ID X-RAY; MAGNETIC MULTILAYERS; SPUTTERING PRESSURE; ROUGHNESS; SCATTERING; NANOWIRES; TRANSPORT; PLANE AB We have correlated a detailed quantitative structural analysis by x-ray diffraction, transmission electron microscopy, and high spatial resolution electron energy-loss spectroscopy imaging, with the magnetization and anisotropic magnetotransport properties in sputtered Fe/Cr superlattices. To accomplish this, we developed a technique for magnetotransport measurements in metallic superlattices with the current perpendicular to the plane of the layers (CPP). Using microfabrication techniques, we have fabricated microstructured Fe/Cr pillars embedded in SiO2 and interconnected with Nb electrodes. Because of the uniform current distribution in the Nh electrodes and the minimization of the superlattice-electrode contact resistance, the method allows a simple and independent measurement of the superlattice resistance and giant magnetoresistance (GMR). Structural and magnetic characterization of [Fe(3 nm)/Cr (1.2 nm)](N) superlattices (where N is the number of repetitions) indicate that the roughness is correlated and increases cumulatively through the superlattice stack with no significant change in the antiferromagnetic coupling. Both the current in-plane and CPP GMR increase with N as the roughness increases. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Div Mat Sci, Berkeley, CA 94720 USA. RP Gomez, ME (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RI Santamaria, Jacobo/N-8783-2016 OI Santamaria, Jacobo/0000-0003-4594-2686 NR 35 TC 32 Z9 32 U1 1 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 AUG 1 PY 2000 VL 62 IS 5 BP 3361 EP 3367 DI 10.1103/PhysRevB.62.3361 PG 7 WC Physics, Condensed Matter SC Physics GA 343QZ UT WOS:000088714200069 ER PT J AU Carlson, EW Orgad, D Kivelson, SA Emery, VJ AF Carlson, EW Orgad, D Kivelson, SA Emery, VJ TI Dimensional crossover in quasi-one-dimensional and high-T-c superconductors SO PHYSICAL REVIEW B LA English DT Review ID HIGH-TEMPERATURE SUPERCONDUCTORS; SPIN-GAP; ELECTRONIC-STRUCTURE; NORMAL-STATE; MAGNETIC CORRELATIONS; PHASE FLUCTUATIONS; NEUTRON-SCATTERING; DOPING DEPENDENCE; CRITICAL-BEHAVIOR; HUBBARD-MODEL AB The one-dimensional electron gas exhibits spin-charge separation and power-law spectral responses to many experimentally relevant probes. Ordering in a quasi-one-dimensional system is necessarily associated with a dimensional crossover, at which sharp quasiparticle peaks, with small spectral weight, emerge from the incoherent background. Using methods of Abelian bosonization, we derive asymptotically correct expressions for the spectral changes induced by this crossover. Comparison is made with experiments on the high-temperature superconductors, which are electronically quasi-one-dimensional on a local scale. C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Carlson, EW (reprint author), Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. NR 108 TC 92 Z9 92 U1 1 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 2000 VL 62 IS 5 BP 3422 EP 3437 DI 10.1103/PhysRevB.62.3422 PG 16 WC Physics, Condensed Matter SC Physics GA 343QZ UT WOS:000088714200076 ER PT J AU Xie, JJ Chen, SP Tse, JS Klug, DD Li, ZQ Uehara, K Wang, LG AF Xie, JJ Chen, SP Tse, JS Klug, DD Li, ZQ Uehara, K Wang, LG TI Phonon instabilities in high-pressure bcc-fcc and the isostructural fcc-fcc phase transitions of Cs SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; LINEAR-RESPONSE; CESIUM; METALS AB The phonon instabilities of cesium related to its pressure-induced bcc:to-fcc((1))-to-fcc((2)) phase transitions are studied using the density-functional perturbation theory. It is found that at low pressure, both the bce and fee Cs are dynamically stable, but fee is thermodynamically metastable. The high-pressure phase transitions of Cs from bcc to fcc((1)) and from fcc((1)) to fcc((2)) are related to the phonon instabilities of the long-wavelength acoustic modes resulted from the negative tetragonal shear elastic constant C'=1/2(C-11-C-12), During the fcc((1))-to-fcc((2)) phase transition, all the phonon modes become soft, making it the most striking feature of this isostructural phase transition. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. RP Xie, JJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 29 TC 20 Z9 21 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 AUG 1 PY 2000 VL 62 IS 6 BP 3624 EP 3629 DI 10.1103/PhysRevB.62.3624 PG 6 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900013 ER PT J AU Widom, M Al-Lehyani, I Moriarty, JA AF Widom, M Al-Lehyani, I Moriarty, JA TI First-principles interatomic potentials for transition-metal aluminides. III. Extension to ternary phase diagrams SO PHYSICAL REVIEW B LA English DT Article ID AL-CU-CO; DECAGONAL QUASI-CRYSTAL; ELECTRONIC-STRUCTURE; SYSTEM; APPROXIMANT; STABILITY; ALLOYS; NI; MODELS AB Modeling structural and mechanical properties of intermetallic compounds and alloys requires detailed knowledge of their interatomic interactions. The first two papers of this series [Phys. Rev. B 56, 7905 (1997); 58, 8967 (1998)] derived first-principles interatomic potentials for transition-metal (TM) aluminides using generalized pseudopotential theory (GPT). Those papers focused on binary alloys of aluminum with first-row transition metals and assessed the ability of GPT potentials to reproduce and elucidate the alloy phase diagrams of Al-Co and Al-Ni. This paper addresses the phase diagrams of the binary alloy Al-Cu and the ternary systems Al-Co-Cu and Al-Co-Ni, using GPT pair potentials calculated in the limit of vanishing transition-metal concentration. Despite this highly simplifying approximation, we find rough agreement with the known low-temperature phase diagrams, up to 50% total TM concentration provided the Co fraction is below 25%. Full composition-dependent potentials and many-body interactions would be required to correct deficiencies at higher Co concentration. Outside this troublesome region, the experimentally determined stable and metastable phases all lie on or near the convex hull of a scatter plot of energy versus composition. We verify, qualitatively, reported solubility ranges extending binary alloys into the ternary diagram in both Al-Co-Cu and Al-Co-Ni. Finally, we reproduce previously conjectured transition-metal positions in the decagonal quasicrystal phase. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Widom, M (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RI Widom, Michael/P-2531-2014 OI Widom, Michael/0000-0001-5972-5696 NR 52 TC 30 Z9 32 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 2000 VL 62 IS 6 BP 3648 EP 3657 DI 10.1103/PhysRevB.62.3648 PG 10 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900016 ER PT J AU Sorensen, MR Mishin, Y Voter, AF AF Sorensen, MR Mishin, Y Voter, AF TI Diffusion mechanisms in Cu grain boundaries SO PHYSICAL REVIEW B LA English DT Article ID 001 TILT BOUNDARIES; MOLECULAR-DYNAMICS; SELF-DIFFUSION; COMPUTER-SIMULATION; POINT-DEFECTS; AU/AG SYSTEM; MIGRATION; SURFACES; KINETICS; MOBILITY AB We investigate atomic mechanisms of grain boundary (GB) diffusion by combining molecular dynamics (MD), molecular statics, the harmonic approximation to atomic vibrations, and kinetic Monte Carlo (KMC) simulations. The most important aspects of this approach are the basin-constrained implementation of MD and an automated location of transition states using the nudged elastic band method. We study two Sigma=5 [001] symmetric tilt GB's in Cu, with atomic interactions described by an embedded-atom potential. Our simulations demonstrate that GB's support both vacancies and interstitials, and that vacancies can show interesting effects such as delocalization and instability at certain GB sites. Besides simple vacancy-atom exchanges, vacancies move by "long jumps" involving a concerted motion of two atoms. Interstitials move through concerted displacements of two or more atoms. More complex mechanisms (such as ring processes) involving larger groups of atoms have also been found. The obtained point defect formation energies and entropies, as well as their migration rate constants calculated within harmonic transition state theory, are used as input to KMC simulations of GB diffusion. The simulations show that GB diffusion can be dominated by either vacancy or interstitial-related mechanisms depending on the GB structure. The KMC simulations also reveal interesting effects such as temperature-dependent correlation factors and the trapping effect. Using the same simulation approach we study mechanisms of point defect generation in GB's and show that such mechanisms also involve collective transitions. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. RP Sorensen, MR (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Mishin, Yuri/P-2020-2015; OI Voter, Arthur/0000-0001-9788-7194 NR 45 TC 138 Z9 143 U1 5 U2 54 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 AUG 1 PY 2000 VL 62 IS 6 BP 3658 EP 3673 DI 10.1103/PhysRevB.62.3658 PG 16 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900017 ER PT J AU Ino, A Kim, C Nakamura, M Yoshida, T Mizokawa, T Shen, ZX Fujimori, A Kakeshita, T Eisaki, H Uchida, S AF Ino, A Kim, C Nakamura, M Yoshida, T Mizokawa, T Shen, ZX Fujimori, A Kakeshita, T Eisaki, H Uchida, S TI Electronic structure of La2-xSrxCuO4 in the vicinity of the superconductor-insulator transition SO PHYSICAL REVIEW B LA English DT Article ID FERMI-SURFACE; DOPING DEPENDENCE; CUO2 PLANE; PHOTOEMISSION; TEMPERATURE; DISPERSION; ANTIFERROMAGNETISM; PHASE; GAP AB We report on the result of angle-resolved photoemission study of La2-xSxCuO4 (LSCO) from an optimally doped superconductor (x=0.15) to an antiferromagnetic insulator (x=0). Near the superconductor insulator transition x similar to 0.05, spectral weight is transferred with hole doping between two coexisting components, suggesting a microscopic inhomogeneity of the doped-hole distribution. For the underdoped LSCO (x less than or equal to 0.12), the dispersive band crossing the Fermi level becomes invisible in the (0,0)-(pi,pi) direction unlike Bi2Sr2CaCu2O8+gamma These observations may be reconciled with the evolution of holes;in the insulator into fluctuating stripes in the superconductor. C1 Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Naruto Univ Educ, Dept Phys, Nara 6308528, Japan. Univ Tokyo, Dept Superconduct, Bunkyo Ku, Tokyo 1138656, Japan. RI Mizokawa, Takashi/E-3302-2015 OI Mizokawa, Takashi/0000-0002-7682-2348 NR 26 TC 146 Z9 147 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 AUG 1 PY 2000 VL 62 IS 6 BP 4137 EP 4141 DI 10.1103/PhysRevB.62.4137 PG 5 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900078 ER PT J AU Fishman, RS AF Fishman, RS TI Spin diffusion in the double-exchange model at T = infinity SO PHYSICAL REVIEW B LA English DT Article ID ANTIFERROMAGNETS; DYNAMICS AB The process of spin diffusion within the double-exchange model is studied on a Bethe lattice in infinite dimension at T=infinity. In the absence of electron hopping, the spin-current correlation function oscillates with a period inversely proportional to the Hund's coupling and the spin-diffusion coefficient D vanishes. Electron hopping causes the correlation function to decay with time and yields a value for D proportional to the electron bandwidth. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Fishman, RS (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Fishman, Randy/C-8639-2013 NR 18 TC 5 Z9 5 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 AUG 1 PY 2000 VL 62 IS 6 BP R3600 EP R3603 DI 10.1103/PhysRevB.62.R3600 PG 4 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900007 ER PT J AU Koshelev, AE AF Koshelev, AE TI Role of in-plane dissipation in dynamics of a Josephson vortex lattice in high-temperature superconductors SO PHYSICAL REVIEW B LA English DT Article ID PARALLEL MAGNETIC-FIELDS; COUPLED LAYERED SUPERCONDUCTORS; COLLECTIVE MODE; QUASI-PARTICLES; SINGLE-CRYSTAL; JUNCTIONS; VORTICES; MOTION; BI2SR2CACU2O8+DELTA AB We calculate the flux-flow resistivity of the Josephson vortex lattice in a layered superconductor taking into account both the interplane and in-plane dissipation channels. We consider the limiting cases of small fields (isolated vortices) and high fields (overlapping vortices). In the case: of the dominating in-plane dissipation, typical for high-temperature superconductors, the field dependence of flux-flow resistivity is characterized by three distinct regions. As usual, at low fields the flux-flow resistivity grows linearly with field. When the Josephson vortices start to overlap the flux-flow resistivity crosses over to the regime of quadratic field dependence. Finally, at very high fields the flux-flow resistivity saturates at the c-axis quasiparticle resistivity. The intermediate quadratic regime indicates the dominant role of the in-plane dissipation mechanism. The shape of the field dependence of the flux-flow resistivity can be used to extract both components of the quasiparticle conductivity. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Koshelev, AE (reprint author), Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 29 TC 22 Z9 22 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 AUG 1 PY 2000 VL 62 IS 6 BP R3616 EP R3619 DI 10.1103/PhysRevB.62.R3616 PG 4 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900011 ER PT J AU Liu, CY Young, AR Lamoreaux, SK AF Liu, CY Young, AR Lamoreaux, SK TI Ultracold neutron upscattering rates in a molecular deuterium crystal SO PHYSICAL REVIEW B LA English DT Article AB A calculation of ultracold neutron (UCN) upscattering rates in molecular deuterium solids has been carried out, taking into account intramolecular excitations and phonons. The different molecular species ortho-D-2 (with even rotational quantum number J) and para-D-2, (with odd J) exhibit significantly different UCN-phonon annihilation cross sections. Para- to ortho-D-2 conversion, furthermore, couples UCN to an energy bath of excited rotational states without mediating phonons. This anomalous upscattering mechanism restricts the UCN lifetime to 4.6 msec in a normal-D-2 solid with 33% para content. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Calif Los Alamos Natl Lab, Phys Div P23, Los Alamos, NM 87545 USA. RP Liu, CY (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NR 10 TC 28 Z9 28 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 2000 VL 62 IS 6 BP R3581 EP R3583 DI 10.1103/PhysRevB.62.R3581 PG 3 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900002 ER PT J AU Olson, CJ Scalettar, RT Zimanyi, GT Gronbech-Jensen, N AF Olson, CJ Scalettar, RT Zimanyi, GT Gronbech-Jensen, N TI Effect of splayed pins on vortex creep and critical currents SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; COLUMNAR DEFECTS; YBA2CU3O7 CRYSTALS; BOSON LOCALIZATION; LINEAR DEFECTS; ANGLES; BI2SR2CACU2O8; CONFIGURATIONS; ENTANGLEMENT; IRRADIATION AB We study the effects of splayed columnar pins on the vortex motion using realistic London-Langevin simulations. At low currents vortex creep is strongly suppressed, whereas the critical current j(c) is enhanced only moderately. Splaying the pins generates an increasing energy barrier against vortex hopping, and leads to the forced entanglement of vortices, both of which suppress creep efficiently. On the other hand splaying enhances kink nucleation and introduces intersecting pins, which cut off the energy barriers. Thus the j(c) enhancement is strongly parameter sensitive. We also characterize the angle dependence of j(c) and the effect of different splaying geometries. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. RP Olson, CJ (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. NR 27 TC 2 Z9 2 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 AUG 1 PY 2000 VL 62 IS 6 BP R3612 EP R3615 DI 10.1103/PhysRevB.62.R3612 PG 4 WC Physics, Condensed Matter SC Physics GA 343XN UT WOS:000088727900010 ER PT J AU Barrette, J Bellwied, R Bennett, S Bersch, R Braun-Munzinger, P Chang, WC Cleland, WE Clemen, M Cole, J Cormier, TM Dai, Y David, G Dee, J Dietzsch, O Drigert, M Filimonov, K Johnson, SC Hall, JR Hemmick, TK Herrmann, N Hong, B Kwon, Y Lacasse, R Li, Q Ludlam, TW Mark, SK Matheus, R McCorkle, S Murgatroyd, JT Miskowiec, D O'Brien, E Panitkin, S Paul, P Piazza, T Pollack, M Pruneau, C Qi, YJ Rao, MN Reber, E Rosati, M daSilva, NC Sedykh, S Sonnadara, U Stachel, J Takagui, EM Pop, VT Voloshin, S Vongpaseuth, TB Wang, G Wessels, JP Woody, CL Xu, N Zhang, Y Zou, C AF Barrette, J Bellwied, R Bennett, S Bersch, R Braun-Munzinger, P Chang, WC Cleland, WE Clemen, M Cole, J Cormier, TM Dai, Y David, G Dee, J Dietzsch, O Drigert, M Filimonov, K Johnson, SC Hall, JR Hemmick, TK Herrmann, N Hong, B Kwon, Y Lacasse, R Li, Q Ludlam, TW Mark, SK Matheus, R McCorkle, S Murgatroyd, JT Miskowiec, D O'Brien, E Panitkin, S Paul, P Piazza, T Pollack, M Pruneau, C Qi, YJ Rao, MN Reber, E Rosati, M daSilva, NC Sedykh, S Sonnadara, U Stachel, J Takagui, EM Pop, VT Voloshin, S Vongpaseuth, TB Wang, G Wessels, JP Woody, CL Xu, N Zhang, Y Zou, C TI Proton and pion production in Au+Au collisions at 10.8A GeV/c SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; AGS ENERGY; CENTRALITY DEPENDENCE; 2-PION CORRELATIONS; 14.6A GEV/C; SPECTRA; DISTRIBUTIONS; AU; DYNAMICS AB We present proton and pion tranverse momentum spectra and rapidity distributions for Au+Au collisions at 10.8A GeV/c. The proton spectra exhibit collective transverse flow effects. Evidence of the influence of the Coulomb interaction from the fireball is found in the pion transverse momentum spectra. The data are compared with the predictions of the RQMD event generator. C1 McGill Univ, Montreal, PQ H3A 2T8, Canada. Brookhaven Natl Lab, Upton, NY 11973 USA. Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Heidelberg, D-69120 Heidelberg, Germany. Idaho Natl Engn Lab, Idaho Falls, ID 83402 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Univ Sao Paulo, Sao Paulo, Brazil. Wayne State Univ, Detroit, MI 48202 USA. RP Barrette, J (reprint author), McGill Univ, Montreal, PQ H3A 2T8, Canada. RI Voloshin, Sergei/I-4122-2013 NR 45 TC 58 Z9 61 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 024901 DI 10.1103/PhysRevC.62.024901 PG 8 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000045 ER PT J AU Bleicher, MJ Bass, SA Bravina, LV Greiner, W Soff, S Stocker, H Xu, N Zabrodin, EE AF Bleicher, MJ Bass, SA Bravina, LV Greiner, W Soff, S Stocker, H Xu, N Zabrodin, EE TI Global observables and secondary interactions in central Au+Au reactions at root s=200A GeV SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; QUARK-GLUON PLASMA; NUCLEUS-NUCLEUS COLLISIONS; ULTRARELATIVISTIC ENERGIES; MOMENTUM CORRELATIONS; HADRONIC-INTERACTIONS; PARTICLE-PRODUCTION; PARTON PRODUCTION; PHASE-TRANSITION; J/PSI PRODUCTION AB The ultrarelativistic quantum molecular dynamics model (UrQMD) is used to study global observables in central reactions of Au+Au at root s=200A GeV at the Relativistic Heavy Ion Collider (RHIC). Strong stopping governed by massive particle production is predicted if secondary interactions are taken into account. The underlying string dynamics and the early hadronic decoupling implies only small transverse expansion rates. However, rescattering with mesons is found to act as a Source of pressure leading to additional flow of baryons and kaons, while cooling down pions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Duke Univ, Dept Phys, Durham, NC 27708 USA. Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. Gesell Schwerionenforsch GmbH, D-6100 Darmstadt, Germany. RP Bleicher, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM bleicher@nta2.lbl.gov RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 65 TC 11 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 024904 DI 10.1103/PhysRevC.62.024904 PG 7 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000048 ER PT J AU Bloch, JCR Ivanov, MA Mizutani, T Roberts, CD Schmidt, SM AF Bloch, JCR Ivanov, MA Mizutani, T Roberts, CD Schmidt, SM TI K ->pi pi and a light scalar meson SO PHYSICAL REVIEW C LA English DT Article ID PION LOOP CONTRIBUTION; DIRECT CP VIOLATION; BETHE-SALPETER; CHARGE-RADIUS; NEUTRAL KAON; FORM-FACTORS; QCD; DECAYS; MODEL; MASS AB We explore the Delta I = 1/2 rule and epsilon'/epsilon in K --> pi pi transitions using a Dyson-Schwinger equation model. Exploiting the feature that quantum chromodynamics penguin operators direct K-S(0) transitions through 0(++). intermediate states, we observe an enhancement of K --> pi pi(I = 0) transitions from the contribution of a putative light sigma-meson. This mechanism also affects epsilon'/epsilon. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Russia. Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. RP Bloch, JCR (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 51 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 025206 DI 10.1103/PhysRevC.62.025206 PG 9 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000056 ER PT J AU Bruce, AM Simpson, J Warner, DD Baktash, C Barton, CJ Bentley, MA Brinkman, MJ Cunningham, RA Dragulescu, E Frankland, L Ginter, TN Gross, CY Lemmon, RC MacDonald, B O'Leary, CD Vincent, SM Wyss, R Yu, CH Zamfir, NV AF Bruce, AM Simpson, J Warner, DD Baktash, C Barton, CJ Bentley, MA Brinkman, MJ Cunningham, RA Dragulescu, E Frankland, L Ginter, TN Gross, CY Lemmon, RC MacDonald, B O'Leary, CD Vincent, SM Wyss, R Yu, CH Zamfir, NV TI Two-neutron alignment and shape changes in As-69 SO PHYSICAL REVIEW C LA English DT Article ID LIFETIME MEASUREMENTS; CLOVER; NUCLEI; REGION; AS-71 AB The nucleus As-69 was Studied using the Ca-40(S-32,3p)As-69 reaction at a beam energy of 105 MeV. An extension of the band built on the g(9/2) orbital was observed to exhibit a band crossing at a rotational frequency of 0.511 MeV with an associated alignment of 7 (h) over bar. This alignment is interpreted as being due to a pair of g(9/2) neutrons. Total Routhian surface calculations have been carried out which confirm that the shape of this nucleus changes from oblate at low spin to a triaxial prolate shape at intermediate spin. C1 Univ Brighton, Sch Engn, Brighton BN2 4GJ, E Sussex, England. SERC, Daresbury Lab, CLRC, Warrington WA4 4AD, Cheshire, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Clark Univ, Worcester, MA 01610 USA. Staffordshire Univ, Sch Sci, Stoke On Trent ST4 2DE, Staffs, England. NIPNE, RO-76900 Bucharest, Romania. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. Royal Inst Technol, Phys Dept Fresacti, S-10405 Stockholm, Sweden. Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06520 USA. RP Univ Brighton, Sch Engn, Brighton BN2 4GJ, E Sussex, England. RI Zamfir, Nicolae Victor/F-2544-2011; OI Bruce, Alison/0000-0003-2871-0517 NR 23 TC 10 Z9 10 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 027303 DI 10.1103/PhysRevC.62.027303 PG 4 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000066 ER PT J AU Christiansen, MB Glendenning, NK Schaffner-Bielich, J AF Christiansen, MB Glendenning, NK Schaffner-Bielich, J TI Surface tension between a kaon condensate and the normal nuclear matter phase SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON-STARS AB We calculate for the first time the surface tension and curvature coefficient of a first-order phase transition between two possible phases of cold nuclear matter, a normal nuclear matter phase in equilibrium with a kaon-condensed phase, at densities. a few times the saturation density. We find the surface tension is proportional to the difference in energy density between the two phases squared. Furthermore, we show the consequences for the geometrical structures of the mixed-phase region in a neutron star. C1 Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Inst Nucl & Particle Astrophys, Berkeley, CA 94720 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Christiansen, MB (reprint author), Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. NR 28 TC 38 Z9 38 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 025804 DI 10.1103/PhysRevC.62.025804 PG 6 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000063 ER PT J AU Hauger, JA Srivastava, BK Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Elliott, JB Gilkes, ML Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, C Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, RP Scott, A Shao, Y Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wienold, T Wolf, K AF Hauger, JA Srivastava, BK Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Elliott, JB Gilkes, ML Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, C Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, RP Scott, A Shao, Y Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wienold, T Wolf, K TI Two-stage multifragmentation of 1A GeV Kr, La, and Au SO PHYSICAL REVIEW C LA English DT Article ID NUCLEAR CALORIC CURVE; HEAVY-ION COLLISIONS; INTRANUCLEAR CASCADE CALCULATION; GAS PHASE-TRANSITION; HOT NUCLEI; FRAGMENT PRODUCTION; ISOTOPE YIELDS; TPC DETECTOR; GOLD NUCLEI; ENERGY AB Multifragmentation in fully reconstructed events from 1A GeV Kr and La collisions with C has been studied. Results are compared with similar data for 1A GeV Au+C. The emitted charged particles and fragments are identified with emission from either a prompt first stage or a second stage in which the remnant resulting from the first stage breaks up. The nuclear charge, mass, and excitation energy distributions of the remnant are determined. The total charged multiplicity, as well as those of the first and second stages are obtained. Freeze-out temperatures and thermal excitation energy permit the determination of the caloric curve. The fragment charge distribution as well as the IMF multiplicity distribution and those of individual Fragments are obtained. The various results are examined as to the extent of universal behavior when scaled for varying system size. Comparisons are made with intranuclear cascade and statistical multifragmentation model calculations. C1 Purdue Univ, W Lafayette, IN 47907 USA. Univ Catania, I-95129 Catania, Italy. Ist Nazl Fis Nucl, Sez Catania, I-95129 Catania, Italy. Univ Calif Davis, Davis, CA 95616 USA. GSI Darmstadt, D-64220 Darmstadt, Germany. Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Augusta State Univ, Augusta, GA 30904 USA. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153 NR 48 TC 43 Z9 44 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 024616 DI 10.1103/PhysRevC.62.024616 PG 14 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000044 ER PT J AU Jenkins, DG Muikku, M Greenlees, PT Hauschild, K Helariutta, K Jones, PM Julin, R Juutinen, S Kankaanpaa, H Kelsall, NS Kettunen, H Kuusiniemi, P Leino, M Moore, CJ Nieminen, P O'Leary, CD Page, RD Rakhila, P Reviol, W Taylor, MJ Uusitalo, J Wadsworth, R AF Jenkins, DG Muikku, M Greenlees, PT Hauschild, K Helariutta, K Jones, PM Julin, R Juutinen, S Kankaanpaa, H Kelsall, NS Kettunen, H Kuusiniemi, P Leino, M Moore, CJ Nieminen, P O'Leary, CD Page, RD Rakhila, P Reviol, W Taylor, MJ Uusitalo, J Wadsworth, R TI First observation of excited states in Pb-182 SO PHYSICAL REVIEW C LA English DT Article ID ESCAPE SUPPRESSED SPECTROMETER; NEUTRON-DEFICIENT; SHAPE COEXISTENCE; ALPHA-DECAY; ISOTOPES; SPECTROSCOPY; IDENTIFICATION; SHELL; HG AB Excited states in the light lead nucleus, Pb-182, have been observed for the first time, by means of the recoil-decay tagging technique. A rotational band has been observed which has features in common with bands attributed to a prolate configuration in the heavier neutron deficient lead nuclei, Pb184-188. A variable moment of inertia fit to the states in this band suggests that the prolate minimum has risen significantly in energy compared to the next even lead nucleus, Pb-184. This constitutes firm evidence for the minimization of this configuration with respect to the spherical ground state around N = 103. C1 Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Univ Jyvaskyla, Accelerator Lab, FIN-40351 Jyvaskyla, Finland. CEA Saclay, DAPNIA, SPhN, F-91191 Gif Sur Yvette, France. Univ Jyvaskyla, Dept Phys, FIN-40351 Jyvaskyla, Finland. Univ Liverpool, Oliver Lodge Lab, Dept Phys, Liverpool L69 7ZE, Merseyside, England. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Jenkins, DG (reprint author), Argonne Natl Lab, Div Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Hauschild, Karl/A-6726-2009; Taylor, Michael/N-1725-2015 OI Taylor, Michael/0000-0002-8718-3684 NR 23 TC 43 Z9 43 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 021302 DI 10.1103/PhysRevC.62.021302 PG 4 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000002 ER PT J AU Paganis, SD Hoffmann, GW Ray, RL Tang, JL Udagawa, T Longacre, RS AF Paganis, SD Hoffmann, GW Ray, RL Tang, JL Udagawa, T Longacre, RS TI Can doubly strange dibaryon resonances be discovered at RHIC? SO PHYSICAL REVIEW C LA English DT Article ID H-DIBARYON; PB+PB COLLISIONS; NEAR-THRESHOLD; K-,K+ REACTION; WEAK DECAY; SEARCH; QUARK; MODEL; MATTER; DIHYPERON AB The baryon-baryon continuum invariant mass spectrum generated from relativistic nucleus + nucleus collision data may reveal the existence of doubly strange dibaryons not stable against strong decay if they lie within a few MeV of threshold. Furthermore, since the dominant component of these states is a superposition of two color-octet clusters which can be produced intermediately in a color-deconfined quark-gluon plasma (QGP), an enhanced production of dibaryon resonances could be a signal of QGP formation. A total of eight, doubly strange dibaryon states are considered for experimental search using the STAR detector (solenoidal tracker at RHIC) at the new Relativistic Heavy Ion Collider (RHIC). These states may decay to Lambda Lambda and/or p Xi(-), depending on the resonance energy. STAR's large acceptance, precision tracking and vertex reconstruction capabilities, and large data volume capacity, make it an ideal instrument to use for such a search. Detector performance and analysis sensitivity are studied as a function of resonance production rate and width for one particular dibaryon which can directly strong decay to p Xi(-), but not Lambda Lambda. Results indicate that such resonances may be discovered using STAR if the resonance production rates are comparable to coalescence model predictions for dibaryon bound states. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Ray, RL (reprint author), Univ Texas, Dept Phys, Austin, TX 78712 USA. EM ray@physics.utexas.edu OI PAGANIS, STATHES/0000-0002-1950-8993 NR 57 TC 4 Z9 4 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 024906 DI 10.1103/PhysRevC.62.024906 PG 12 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000050 ER PT J AU Urban, W Kurcewicz, W Korgul, A Daly, PJ Bhattacharyya, P Zhang, CT Durell, JL Leddy, MJ Jones, MA Phillips, WR Smith, AG Varley, BJ Bentaleb, M Lubkiewicz, E Schulz, N Ahmad, I Morss, LR Blomqvist, J AF Urban, W Kurcewicz, W Korgul, A Daly, PJ Bhattacharyya, P Zhang, CT Durell, JL Leddy, MJ Jones, MA Phillips, WR Smith, AG Varley, BJ Bentaleb, M Lubkiewicz, E Schulz, N Ahmad, I Morss, LR Blomqvist, J TI Medium-spin structure of single valence-proton nucleus Sb-133 SO PHYSICAL REVIEW C LA English DT Article ID GAMMA-RAY; TRANSITION; FISSION AB Excited states in the nucleus Sb-133, populated in spontaneous fission of Cm-248, were studied with EUROGAM2. Medium-spin structure, described as the nu(f(7/2)h(11/2)(-1)) multiplet of the Sn-132 core coupled to the odd proton in the g(7/2) orbital, has been identified in this nucleus. Levels corresponding to the octupole excitations of the Sb-132 core were also identified. Some uncertainities concerning isomeric decays in Sb-133, observed in previous works, have been resolved. C1 Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Univ Manchester, Schuster Lab, Dept Phys, Manchester M13 9PL, Lancs, England. Inst Rech Subatom, CNRS, IN2P3, F-67037 Strasbourg, France. Univ Strasbourg 1, F-67037 Strasbourg, France. Argonne Natl Lab, Argonne, IL 60439 USA. Royal Inst Technol, Dept Phys Frescati, S-10405 Stockholm, Sweden. RP Urban, W (reprint author), Univ Warsaw, Inst Expt Phys, Ul Hoza 69, PL-00681 Warsaw, Poland. NR 8 TC 17 Z9 17 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 027301 DI 10.1103/PhysRevC.62.027301 PG 4 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000064 ER PT J AU Wiedeking, M Kaye, RA Solomon, GZ Tabor, SL Doring, J Johns, GD Cristancho, F Devlin, M Lerma, F Sarantites, DG Lee, IY Macchiavelli, AO AF Wiedeking, M Kaye, RA Solomon, GZ Tabor, SL Doring, J Johns, GD Cristancho, F Devlin, M Lerma, F Sarantites, DG Lee, IY Macchiavelli, AO TI Transition strengths in odd-odd Nb-86 SO PHYSICAL REVIEW C LA English DT Article ID HIGH-SPIN STATES; SIGNATURE INVERSION; QUASIPARTICLE; BEHAVIOR; NUCLEI; RATES; BAND AB High angular momentum states in odd-odd Nb-86 Were populated through the Ni-58(S-32,3pn) reaction at 135 MeV. Recoiling Nb-86 nuclei were stopped in a thick Ta backing. Prompt multi-gamma coincidences with evaporated charged particles were detected using the full array of Gammasphere and thr Microball. Mean lifetimes of 51 levels in Nb-86 were measured using the Doppler-shift attenuation method. Strongly alternating magnetic dipole transition strengths were observed in the yrast positive-parity bands. Most of the transition quadrupole moments inferred from the lifetimes lie in the range of 1 to 2.7 eb, which would correspond to quadrupole deformations beta(2) Of 0.10 to 0.27 in a rotational model. Comparison with Hartree-Fock-Bogoliubov cranking calculations suggests triaxial to oblate shapes. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Nacl Colombia, Dept Fis, Bogota, Colombia. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Wiedeking, M (reprint author), Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 19 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 2000 VL 62 IS 2 AR 024316 DI 10.1103/PhysRevC.62.024316 PG 13 WC Physics, Nuclear SC Physics GA 343QX UT WOS:000088714000021 ER PT J AU Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Akimov, V 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 Bassler, U Bean, A Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buehler, M Buescher, V Burtovoi, VS Butler, JM Canelli, F Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D 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 Doulas, S Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelman, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G 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 Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Juste, A Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McMahon, T Melanson, HL Meng, XC Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Simak, V Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Soustruznik, K Souza, M Stanton, NR Steinbruck, G Stephens, RW Sevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Taylor, W Tentindo-Repond, S Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Van Kooten, R Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Wang, H Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Akimov, V 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 Bassler, U Bean, A Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buehler, M Buescher, V Burtovoi, VS Butler, JM Canelli, F Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D 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 Doulas, S Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelman, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G 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 Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Juste, A Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McMahon, T Melanson, HL Meng, XC Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Simak, V Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Soustruznik, K Souza, M Stanton, NR Steinbruck, G Stephens, RW Sevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Taylor, W Tentindo-Repond, S Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Van Kooten, R Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Wang, H Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A CA DO Collaboration TI Limits on quark compositeness from high energy jets in (p)over-bar-p collisions at 1.8 TeV SO PHYSICAL REVIEW D LA English DT Article ID DIJET ANGULAR-DISTRIBUTIONS; CROSS-SECTION; PARTON DISTRIBUTIONS; GLOBAL ANALYSIS; ROOT-S=1.8TEV; DETECTOR; PHYSICS; SEARCH AB Events in (p) over bar p collisions at root s = 1.8 TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV at 95% confidence on the energy scale Lambda(LL) for compositeness in quarks. assuming a model with a left-left isoscalar contact interaction term. The limits on Lambda(LL) are found to be insensitive to the sign of the interference term in the Lagrangian. 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. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Los Andes, Bogota, Colombia. Charles Univ, Prague, Czech Republic. Acad Sci Czech Republ, Inst Phys, Prague, Czech Republic. Univ San Francisco, Quito, Ecuador. Univ Grenoble 1, CNRS, Inst Sci Nucl, IN2P3, Grenoble, France. Univ Mediterranee, CPPM, CNRS, IN2P3, Marseille, France. Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, IN2P3, CNRS, Paris, France. CEA, DAPNIA, Serv Phys Particules, Saclay, France. Panjab Univ, Chandigarh 160014, India. Univ Delhi, Delhi 110007, India. Tata Inst Fundamental Res, Mumbai, India. 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 MV Lomonosov State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. Univ Lancaster, Lancaster, England. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Calif State Univ Fresno, Fresno, CA 93740 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Florida State Univ, Tallahassee, FL 32306 USA. 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. Iowa State Univ, Ames, IA 50011 USA. Univ Kansas, Lawrence, KS 66045 USA. Kansas State Univ, Manhattan, KS 66506 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Nebraska, Lincoln, NE 68588 USA. Columbia Univ, New York, NY 10027 USA. NYU, New York, NY 10003 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. Univ Washington, Seattle, WA 98195 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; Canelli, Florencia/O-9693-2016; Peters, Michael/B-4973-2009; Shivpuri, R K/A-5848-2010; Santoro, Alberto/E-7932-2014; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013 OI Kim, Sun Kee/0000-0002-0013-0775; Canelli, Florencia/0000-0001-6361-2117; Dudko, Lev/0000-0002-4462-3192; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; NR 22 TC 11 Z9 11 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 031101 DI 10.1103/PhysRevD.62.031101 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300001 ER PT J AU Alexopoulos, T Antoniazzi, L Arenton, M Ballagh, HC Bingham, H Blankman, A Block, M Boden, A Bonomi, G Cao, ZL Chen, TY Clark, K Cline, D Conetti, S Cooper, M Corti, G Cox, B Creti, P Dukes, EC Durandet, C Elia, V Erwin, AR Fortney, L Golovatyuk, V Gorini, E Grancagnolo, F Hagan, K Haire, M Hanlet, P He, M Introzzi, G Jenkins, M Judd, D Kononenko, W Kowald, W Lau, K Ledovskoy, A Liguori, G Lys, J Mazur, PO McManus, AP Misawa, S Mo, GH Murphy, CT Nelson, K Pogosyan, V Ramachandran, S Rhoades, J Selove, W Smith, RP Spiegel, L Sun, JG Tokar, S Torre, P Trischuk, J Turnbull, L Wagoner, DE Wang, CR Wei, C Yang, W Yao, N Zhang, NJ Zou, BT AF Alexopoulos, T Antoniazzi, L Arenton, M Ballagh, HC Bingham, H Blankman, A Block, M Boden, A Bonomi, G Cao, ZL Chen, TY Clark, K Cline, D Conetti, S Cooper, M Corti, G Cox, B Creti, P Dukes, EC Durandet, C Elia, V Erwin, AR Fortney, L Golovatyuk, V Gorini, E Grancagnolo, F Hagan, K Haire, M Hanlet, P He, M Introzzi, G Jenkins, M Judd, D Kononenko, W Kowald, W Lau, K Ledovskoy, A Liguori, G Lys, J Mazur, PO McManus, AP Misawa, S Mo, GH Murphy, CT Nelson, K Pogosyan, V Ramachandran, S Rhoades, J Selove, W Smith, RP Spiegel, L Sun, JG Tokar, S Torre, P Trischuk, J Turnbull, L Wagoner, DE Wang, CR Wei, C Yang, W Yao, N Zhang, NJ Zou, BT CA E771 Collaboration TI Hadroproduction of the chi(1) and chi(2) states of charmonium in 800-GeV/c proton-silicon interactions SO PHYSICAL REVIEW D LA English DT Article ID COLOR-OCTET MODEL; J-PSI; TRANSVERSE-MOMENTUM; HADRONIC COLLISIONS; J/PSI-PRODUCTION; QUARKONIUM; UPSILON; TARGET; GLUON AB The cross sections for the hadroproduction of the chi(1) and chi(2) states of charmonium in proton-silicon collisions at root s = 38.8 GeV have been measured in Fermilab fixed target experiment 771. The chi states were observed via their radiative decay to J/psi gamma, where the photon converted to e(+)e(-) i(n) the material of the spectrometer. The estimated values for the chi(1) and chi(2) cross sections for x(F) > 0 are 263 +/- 69(stat) +/- 32(syst) and 498 +/- 143(stat) +/- 67(syst) nb per nucleon, respectively. The resulting sigma(chi(1))/sigma(chi(2)) ratio of 0.53 +/- 0.20(stat) +/- 0.07( syst), although somewhat larger than most theoretical expectations, can be accommodated by the latest theoretical estimates. C1 Univ Virginia, Charlottesville, VA 22901 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Comenius Univ, Bratislava, Slovakia. Duke Univ, Durham, NC 27706 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Houston, Houston, TX 77204 USA. Univ Lecce, I-73100 Lecce, Italy. Ist Nazl Fis Nucl, I-73100 Lecce, Italy. McGill Univ, Montreal, PQ H3A 2T8, Canada. Nanjing Univ, Nanjing 210008, Peoples R China. Northwestern Univ, Evanston, IL 60208 USA. Univ Pavia, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Penn, Philadelphia, PA 19104 USA. Prairie View A&M, Prairie View, TX 77446 USA. Shandong Univ, Shandong, Peoples R China. Univ S Alabama, Mobile, AL 36688 USA. Vanier Coll, St Laurent, PQ H4L 3X9, Canada. Univ Virginia, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Cox, B (reprint author), Univ Virginia, Charlottesville, VA 22901 USA. EM cox@uvahep.phys.virginia.edu RI Bonomi, Germano/G-4236-2010; Introzzi, Gianluca/K-2497-2015 OI Bonomi, Germano/0000-0003-1618-9648; Introzzi, Gianluca/0000-0002-1314-2580 NR 23 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 032006 DI 10.1103/PhysRevD.62.032006 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300009 ER PT J AU Ambrogiani, M Bagnasco, S Baldini, W Bettoni, D Borreani, G Buzzo, A Calabrese, R Cardarelli, M Cester, R Dalpiaz, P Dobbs-Dixon, I Fan, X Garzoglio, G Gollwitzer, K Hahn, A Jin, S Kasper, J Lasio, G Lo Vetere, M Luppi, E Maas, P Macri, M Mandelkern, M Marchetto, F Marinelli, M Marsh, W Martini, M Menichetti, E Mussa, R Obertino, MM Pallavicini, M Pastrone, N Patrignani, C Pedlar, TK Peoples, J Pordes, S Robutti, E Rosen, J Rumerio, P Santroni, A Savrie, M Schultz, J Seth, KK Stancari, G Stancari, M Streets, J Tomaradze, A Werkema, S Zioulas, G AF Ambrogiani, M Bagnasco, S Baldini, W Bettoni, D Borreani, G Buzzo, A Calabrese, R Cardarelli, M Cester, R Dalpiaz, P Dobbs-Dixon, I Fan, X Garzoglio, G Gollwitzer, K Hahn, A Jin, S Kasper, J Lasio, G Lo Vetere, M Luppi, E Maas, P Macri, M Mandelkern, M Marchetto, F Marinelli, M Marsh, W Martini, M Menichetti, E Mussa, R Obertino, MM Pallavicini, M Pastrone, N Patrignani, C Pedlar, TK Peoples, J Pordes, S Robutti, E Rosen, J Rumerio, P Santroni, A Savrie, M Schultz, J Seth, KK Stancari, G Stancari, M Streets, J Tomaradze, A Werkema, S Zioulas, G CA Fermilab E835 Collaboration TI Measurement of the branching ratios psi ' -> e(+)e(-), psi ' -> J/psi pi(0) pi(0) and psi ' -> J/psi eta SO PHYSICAL REVIEW D LA English DT Article ID PARTICLE PHYSICS; FERMILAB; EXPERIMENT-835; ANNIHILATION; CALORIMETER; E760 AB We have determined the following psi' branching ratios using the large event sample collected by Fermilab experiment E835 in the reaction -->psi': B(psi'--> e(+)e(-)) = (7.4 +/- 0.2 +/- 0.7) x 10(-3), B(psi'--> J/psi pi(0)pi(0)) = (18.7 +/- 0.9 +/- 1.3)% and B(psi'--> J/psi eta) = (4.1 +/- 0.3 +/- 0.5)%. C1 Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Univ Genoa, I-16146 Genoa, Italy. Univ Calif Irvine, Irvine, CA 92697 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Turin, I-10125 Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. RP Ambrogiani, M (reprint author), Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. RI Patrignani, Claudia/C-5223-2009; Luppi, Eleonora/A-4902-2015; Calabrese, Roberto/G-4405-2015; Lo Vetere, Maurizio/J-5049-2012; Pallavicini, Marco/G-5500-2012 OI Patrignani, Claudia/0000-0002-5882-1747; Luppi, Eleonora/0000-0002-1072-5633; Calabrese, Roberto/0000-0002-1354-5400; Lo Vetere, Maurizio/0000-0002-6520-4480; Pallavicini, Marco/0000-0001-7309-3023 NR 15 TC 13 Z9 13 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 032004 DI 10.1103/PhysRevD.62.032004 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300007 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, ZJ Guo, YN Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Heng, YK Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, GS Huang, YZ Izen, JM Jiang, CH Jin, Y Jones, BD Ju, X Ke, ZJ Kelsey, MH Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, JC 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, N 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, HX 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, C Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, L Zhang, LS Zhang, P 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, ZJ Guo, YN Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Heng, YK Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, GS Huang, YZ Izen, JM Jiang, CH Jin, Y Jones, BD Ju, X Ke, ZJ Kelsey, MH Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, JC 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, N 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, HX 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, C Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, L Zhang, LS Zhang, P 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 psi(2S) -> pi(+) pi(-) J/psi decay distributions SO PHYSICAL REVIEW D LA English DT Article ID EXCITED HEAVY QUARKONIA; HADRONIC TRANSITIONS; STATES; ANOMALIES AB Using a sample of 3.8 M psi(2S) events accumulated with the BES detector, the process psi(2S) --> pi(+) pi(r)-J/psi is studied. The angular distributions are compared with the general decay amplitude analysis of Cahn. We find that the dipion system requires some D wave amplitude, as well as S wave. On the other hand, the J/psi-(pi(+)pi(-)) relative angular momentum is consistent with being pure S wave. The decay distributions have been fit to heavy quarkonium models, including the Novikov-Shifman model. This model, which is written in terms of the parameter kappa, predicts that D wave pions should be present. We determine kappa = 0.183 +/- 0.002 +/- 0.003 based on the joint m(pi pi)-cos theta(pi)* distribution. The fraction of D wave amplitude as a function of m(pi pi) is found to decrease with increasing m(pi pi), in agreement with the model. We have also fit the Mannel-Yan model, which is another model that allows D wave pions. 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 Dallas, Richardson, TX 75083 USA. RP Bai, JZ (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China. RI Chen, Yu/E-3788-2012 NR 20 TC 51 Z9 51 U1 2 U2 7 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 AUG 1 PY 2000 VL 62 IS 3 AR 032002 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300005 ER PT J AU Brhlik, M Everett, L Kane, GL Lykken, J AF Brhlik, M Everett, L Kane, GL Lykken, J TI Superstring theory and CP-violating phases: Can they be related? SO PHYSICAL REVIEW D LA English DT Review ID ELECTRIC-DIPOLE MOMENT; SUPERSYMMETRIC STANDARD MODEL; SOFT TERMS; ORBIFOLD COMPACTIFICATIONS; STRING UNIFICATION; EXPERIMENTAL LIMIT; F-THEORY; PHENOMENOLOGICAL VIABILITY; ANOMALY CANCELLATION; GAUGINO CONDENSATION AB We investigate the possibility of large CP-violating phases in the soft breaking terms derived in superstring models. The bounds on the electric dipole moments (EDM's) of the electron and neutron are satisfied through cancellations occurring because of the structure of the string models. Three general classes of four-dimensional string models are considered: (i) orbifold compactifications of perturbative heterotic string theory, (ii) scenarios based on Horava-Witten theory, and (iii) type I string models (type IIB orientifolds). Nonuniversal phases of the gaugino mass parameters greatly facilitate the necessary cancellations among the various contributions to the EDM's; in the overall modulus limit, the gaugino masses are universal at the tree level in both the perturbative heterotic models and the Horava-Witten scenarios, which severely restricts the allowed regions of parameter space. Nonuniversal gaugino masses do arise at one-loop in the heterotic orbifold models, providing for corners of parameter space with O(1) phases consistent with the phenomenological bounds. However, there is a possibility of nonuniversal gaugino masses at the tree level in the type I models, depending on the details of the embedding of the SM into the D-brane sectors. We find that, in a minimal model with a particular embedding of the standard model gauge group into two D-brane sectors, viable large phase solutions can be obtained over a wide range of parameter space. 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 115 TC 75 Z9 76 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 035005 DI 10.1103/PhysRevD.62.035005 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300055 ER PT J AU Demina, R Lykken, JD Matchev, KT Nomerotski, A AF Demina, R Lykken, JD Matchev, KT Nomerotski, A TI Top and bottom squark searches in run II of the Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Review ID MEDIATED SUPERSYMMETRY-BREAKING; LARGE-TAN-BETA; ELECTROWEAK SYMMETRY-BREAKING; MINIMAL SUPERGRAVITY MODEL; LOW-ENERGY SUPERSYMMETRY; JET CROSS-SECTIONS; HADRON COLLIDERS; SCALAR TOP; LIGHT STOP; STANDARD MODEL AB We estimate the Fermilab Tevatron run II potential for top and bottom squark searches. We find an impressive reach in several of the possible discovery channels. We also study some new channels which may arise in nonconventional supersymmetry models. In each case we rely on a detailed Monte Carlo simulation of the collider events and the CDF detector performance in run I. C1 Kansas State Univ, Dept Phys & Astron, Manhattan, KS 66506 USA. Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. RP Kansas State Univ, Dept Phys & Astron, Manhattan, KS 66506 USA. RI Nomerotski, Andrei/A-5169-2010 NR 119 TC 56 Z9 56 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 AUG 1 PY 2000 VL 62 IS 3 AR 035011 DI 10.1103/PhysRevD.62.035011 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300061 ER PT J AU Goto, Y Hayashi, N Hirai, M Horikawa, H Kumano, S Miyama, M Morii, T Saito, N Shibata, TA Taniguchi, E Yamanishi, T AF Goto, Y Hayashi, N Hirai, M Horikawa, H Kumano, S Miyama, M Morii, T Saito, N Shibata, TA Taniguchi, E Yamanishi, T TI Polarized parton distribution functions in the nucleon SO PHYSICAL REVIEW D LA English DT Article ID DEEP-INELASTIC-SCATTERING; NEUTRON SPIN STRUCTURE; STRUCTURE-FUNCTION G(1)(N); Q(2) EVOLUTION-EQUATIONS; GLUON DISTRIBUTIONS; SPLITTING FUNCTIONS; NUMERICAL-SOLUTION; MUON SCATTERING; GLOBAL ANALYSIS; E-P AB Polarized parton distribution functions are determined by using world data from the longitudinally polarized deep inelastic scattering experiments. A new parametrization of the parton distribution functions is adopted by taking into account the positivity and the counting rule. From the fit to the asymmetry data A(1), the polarized distribution functions of u and d valence quarks, sea quarks, and gluons are obtained. The results indicate that the quark spin content is Delta Sigma = 0.20 and 0.05 in the leading order (LO) and the next-to-leading-order (NLO) <(MS)over bar> scheme, respectively. However, if the x dependence of the sea-quark distribution is fixed at small x by ''perturbative QCD'' and Regge theory, it becomes Delta Sigma = 0.24-0.28 in the NLO. The small-x behavior cannot be uniquely determined by the existing data, which indicates the importance of future experiments. From our analysis, we propose one set of LO distributions and two sets of NLO ones as the longitudinally polarized parton distribution functions. C1 Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. RIKEN, Inst Phys & Chem Res, Radiat Lab, Wako, Saitama 3510198, Japan. Saga Univ, Dept Phys, Saga 8408502, Japan. Kobe Univ, Fac Human Dev, Kobe, Hyogo 6578501, Japan. Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan. Fukui Univ Technol, Dept Management Sci, Fukui 9108505, Japan. RP Goto, Y (reprint author), Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. NR 58 TC 158 Z9 158 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 034017 DI 10.1103/PhysRevD.62.034017 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300035 ER PT J AU Kaplan, DE Kribs, GD Schmaltz, M AF Kaplan, DE Kribs, GD Schmaltz, M TI Supersymmetry breaking through transparent extra dimensions SO PHYSICAL REVIEW D LA English DT Article ID KALUZA-KLEIN EXCITATIONS; STANDARD MODEL; ANOMALOUS U(1); FLAVOR PROBLEM; FERMILAB TEVATRON; SCALE; COMPACTIFICATION; RENORMALIZATION; SUPERGRAVITY; CONSTRAINTS AB We propose a new framework for mediating supersymmetry breaking through an extra dimension. It predicts positive scalar masses and solves the supersymmetric flavor problem. Supersymmetry breaks on a "source" brane that is spatially separated from a parallel brane on which the standard model matter fields and their superpartners live. The gauge and gaugino fields propagate in the bulk, the latter receiving a supersymmetry breaking mass from direct couplings to the source brane. Scalar masses are suppressed at the high scale hut are generated via the renormalization group. We briefly discuss the spectrum and collider signals for a range of compactification scales. C1 Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Univ Chicago, Enrico Fermi Inst, Dept Phys, 5640 Ellis Ave, Chicago, IL 60637 USA. EM dkaplan@theory.uchicago.edu; kribs@cmu.edu; schmaltz@slac.stanford.edu NR 74 TC 336 Z9 336 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 035010 DI 10.1103/PhysRevD.62.035010 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300060 ER PT J AU Landsberg, G Matchev, KT AF Landsberg, G Matchev, KT TI Discovering a light Higgs boson with light SO PHYSICAL REVIEW D LA English DT Article ID UPGRADED FERMILAB TEVATRON; STANDARD MODEL; 2 PHOTONS; SEARCH; DECAYS; PARTICLES; REACH; COLLISIONS; TRILEPTON AB We evaluate the prospects for detecting a non-standard light Higgs boson with a significant branching ratio to two photons, in run II of the Fermilab Tevatron. We derive the reach for several channels: 2 gamma inclusive, 2 gamma + 1 jet, and 2 gamma + 2 jets. We present the expected run II limits on the branching ratio of h --> gamma gamma as a function of the Higgs boson mass, for the case of "bosonic," as well as "top-color" Higgs bosons. C1 Brown Univ, Dept Phys, Providence, RI 02912 USA. Fermi Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Landsberg, G (reprint author), Brown Univ, Dept Phys, 182 Hope St, Providence, RI 02912 USA. NR 45 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 035004 DI 10.1103/PhysRevD.62.035004 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300054 ER PT J AU Lee, W Weingarten, D AF Lee, W Weingarten, D TI Coupling constant and quark-loop expansion for corrections to the valence approximation - Reply SO PHYSICAL REVIEW D LA English DT Letter ID LATTICE QCD; SCALAR GLUEBALL AB In a recent article we presented an argument which, we believe, shows to be incorrect an estimate by Boglione and Pennington of corrections to the valence (quenched) approximation predictions for the properties of the lightest scalar glueball. The Boglione-Pennington reply to our article, it appears to us, fails to address the specific technical issues we raised. C1 IBM Corp, Res, Yorktown Hts, NY 10598 USA. RP Los Alamos Natl Lab, Grp T8, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 038502 DI 10.1103/PhysRevD.62.038502 PG 2 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300080 ER PT J AU Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ AF Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ CA CLEO Collaboration TI Study of the decays B-0 -> D(*)+ D(*)- SO PHYSICAL REVIEW D LA English DT Article ID DIRECT CP VIOLATION; NEUTRAL KAON; B-MESON; CONSTANTS; MODEL; ASYMMETRIES; DETECTOR AB The decays B-0--> D*D+*(-), B-0--> D*D-+/-(-/+) and B(-)i --> D+D- are studied in 9.7 x 10(6) Y(4S)-->B(B) over bar $ decays accumulated with the CLEO detector. We determine B(B-0--> D*D+*(-)) = (9.9(-3.3)(divided by 4.2)[stat] +/- 1.2[syst]) x 10(-4) and limit B(B-->D*D+/-*(-/+)) < 6.3 x 10(-4) and B(B-0--> D+D-) < 9.4 x 10(-4) at 90% confidence level (C.L.). We also perform the first angular analysis of the B-0--> D*D+*(-) decay and determine that the CP-even fraction of the Anal state is greater than 0.11 at 90% C.L. Future measurements of the time dependence of these decays may be useful for the investigation of CP violation in neutral B meson decays. C1 CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Texas, Austin, TX 78712 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. RP CALTECH, Pasadena, CA 91125 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014 OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039 NR 33 TC 6 Z9 6 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 032005 DI 10.1103/PhysRevD.62.032005 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300008 ER PT J AU Puglia, SJ Ramsey-Musolf, MJ AF Puglia, SJ Ramsey-Musolf, MJ TI Baryon octet magnetic moments in chiral perturbation theory: More on the importance of the decuplet SO PHYSICAL REVIEW D LA English DT Article ID SIGMA-TERMS; QUARK-MODEL AB We address the impact of treating the decuplet of spin-3/2 baryons as an explicit degree of freedom in the chiral expansion of the magnetic moments of the octet of spin-1/2 baryons. We carry out a complete calculation of the octet moments to O(1/Lambda(chi)(3)), including decuplet contributions to the chiral loops. In contrast with results of previous analyses, we iind that inclusion of the decuplet preserves the convergence behavior of the chiral expansion implied by power counting arguments. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Thomas Jefferson Natl Lab, Theory Grp, Newport News, VA 23606 USA. RP Puglia, SJ (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NR 20 TC 34 Z9 34 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 034010 DI 10.1103/PhysRevD.62.034010 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300028 ER PT J AU Rischke, DH AF Rischke, DH TI Debye screening and the Meissner effect in a two-flavor color superconductor SO PHYSICAL REVIEW D LA English DT Article ID DENSITY QUARK MATTER; FINITE BARYON DENSITY; SUPERFLUIDITY; SYSTEMS; QCD AB I compute the gluon self-energy in a color superconductor with two flavors of massless quarks, where condensation of Cooper pairs breaks SU(3)(c) to SU(2)(c). At zero temperature, there is neither Debye screening nor a Meissner effect for the three gluons of the unbroken SU(2)(c) subgroup. The remaining five gluons attain an electric as well as a magnetic mass. For temperatures approaching the critical temperature for the onset of color superconductivity, or for gluon momenta much larger than the color-superconducting gap, the self-energy assumes the form given by the standard hard-dense loop approximation. The gluon self-energy determines the coefficient of the kinetic term in the effective low-energy theory for the condensate fields. C1 Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. RP Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. EM rischke@bnl.gov NR 34 TC 103 Z9 105 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 AUG 1 PY 2000 VL 62 IS 3 AR 034007 DI 10.1103/PhysRevD.62.034007 PG 22 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300025 ER PT J AU Schafer, T AF Schafer, T TI Gluino condensation in an interacting instanton ensemble SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL-SYMMETRY-BREAKING; SUPERSYMMETRIC GAUGE-THEORIES; YANG-MILLS THEORY; QCD DIRAC OPERATOR; SPECTRAL DENSITY; GLUODYNAMICS; CALCULUS; VACUUM; SU(N) AB We perform a semiclassical study of chiral symmetry breaking and of the spectrum of the Dirac operator in QCD with adjoint fermions. For this purpose we calculate matrix elements of the adjoint Dime operator between instanton zero modes and study their symmetry properties. We present simulations of the instanton ensemble for different numbers of Majorana fermions in the adjoint representation. These simulations provide evidence that instantons lead to gluino condensation in supersymmetric gluodynamics. C1 SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Riken BNL Res Ctr, Upton, NY 11973 USA. RP SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. NR 45 TC 3 Z9 3 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 AUG 1 PY 2000 VL 62 IS 3 AR 035013 DI 10.1103/PhysRevD.62.035013 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300063 ER PT J AU Schnabel, M Wettig, T AF Schnabel, M Wettig, T TI Fake symmetry transitions in lattice Dirac spectra SO PHYSICAL REVIEW D LA English DT Article ID EXACTLY MASSLESS QUARKS; RANDOM-MATRIX THEORY; QCD; OPERATOR; FERMIONS AB In a recent lattice investigation of Ginsparg-Wilson-type Dirac operators in the Schwinger model, it was found that the symmetry class of the random matrix theory describing the small Dirac eigenvalues appeared to change from the unitary to the symplectic case as a function of lattice size and coupling constant. We present a natural explanation for this observation in the framework of a random matrix model, showing that the apparent change is caused by the onset of chiral symmetry restoration in a finite volume. A transition from unitary to symplectic symmetry does not occur. C1 Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Yale Univ, Ctr Theoret Phys, New Haven, CT 06520 USA. Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. RP Schnabel, M (reprint author), Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. NR 16 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 2000 VL 62 IS 3 AR 034501 DI 10.1103/PhysRevD.62.034501 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300041 ER PT J AU Zhu, SL Puglia, SJ Holstein, BR Ramsey-Musolf, MJ AF Zhu, SL Puglia, SJ Holstein, BR Ramsey-Musolf, MJ TI Nucleon anapole moment and parity-violating ep scattering SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PERTURBATION-THEORY; BARYON MAGNETIC-MOMENTS; PROTON-PROTON SCATTERING; PARTICLE PHYSICS; NEUTRAL-CURRENT; FORM-FACTORS; NONCONSERVATION; COUPLINGS; CESIUM; MODEL AB Parity-violating (FV) interactions among quarks in the nucleon induce a PV gamma NN coupling, or anapole moment (AM). We compute electroweak gauge-independent contributions to the AM through O(1/Lambda(chi)(2)) in chiral perturbation theory. We estimate short-distance PV effects using resonance saturation. The AM contributions to PV electron-proton scattering slightly enhance the axial vector radiative corrections, R-A(p),over the scale implied by the standard model when weak quark-quark interactions are neglected. We estimate the theoretical uncertainty associated with the AM contributions to R-A(p) to be large, and discuss the implications for the interpretation PV of ep scattering. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Thomas Jefferson Natl Lab, Theory Grp, Newport News, VA 23606 USA. Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. RP Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NR 46 TC 118 Z9 120 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 AUG 1 PY 2000 VL 62 IS 3 AR 033008 DI 10.1103/PhysRevD.62.033008 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 340CV UT WOS:000088516300018 ER PT J AU Phoenix, SL Beyerlein, IJ AF Phoenix, SL Beyerlein, IJ TI Distributions and size scalings for strength in a one-dimensional random lattice with load redistribution to nearest and next-nearest neighbors SO PHYSICAL REVIEW E LA English DT Article ID DEPENDENT DAMAGE EVOLUTION; BUNDLES PROBABILITY MODEL; NOTCHED COMPOSITE LAMINA; FIBROUS MATERIALS; RANDOM RESISTOR; PERCOLATION MODELS; MATERIAL BREAKDOWN; FIBER COMPOSITES; SOLVABLE MODELS; WEIBULL FIBERS AB Lattice and network models with elements that have random strength are useful tools in explaining various statistical features of failure in heterogeneous materials, including the evolution of failure clusters and overall strength distributions and size effects. Models have included random fuse and spring networks where Monte Carlo simulation coupled to scaling analysis from percolation theory has been a common approach. Unfortunately, severe computational demands have limited the network sizes that can be treated. To gain insight at large size scales, interest has returned to idealized fiber bundle models in one dimension. Many models can be solved exactly or asymptotically in increasing size n, but at the expense of major simplification of the local stress redistribution mechanism. Models have typically assumed either equal load-sharing among nonfailed elements, or nearest-neighbor, local load-sharing (LLS) where a failed element redistributes its load onto its two nearest flanking survivors. The present work considers a one-dimensional fiber bundle model under tapered load sharing (TLS), which assumes load redistribution to both the nearest and next-nearest neighbors in a two-to-one ratio. This rule reflects features found in a discrete mechanics model for load transfer in two-dimensional fiber composites and planar lattices. We assume that elements have strength 1 or 0, with probability p and q = 1 - p, respectively. We determine the structure and probabilities for critical configurations of broken fibers, which lead to bundle failure under a given load. We obtain rigorous asymptotic results for the strength distribution and size effect, as n --> infinity, with precisely determined constants and exponents. The results are a nontrivial extension of those under US in that failure clusters are combinatorially much more complicated and contain many bridging fibers. Consequently, certain probabilities are eigenvalues from recursive equations arising from the structure of TLS. Next-nearest neighbor effects weaken the material beyond what is predicted under LLS keeping only nearest neighbor overloads. Our results question the validity of scaling relationships that are based largely on Monte Carlo simulations on networks of limited size since some failure configurations appear only in extremely large bundles. The dilemma has much in common with the Petersburg paradox. C1 Cornell Univ, Dept Theoret & Appl Mech, Ithaca, NY 14853 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Phoenix, SL (reprint author), Cornell Univ, Dept Theoret & Appl Mech, Ithaca, NY 14853 USA. RI Beyerlein, Irene/A-4676-2011 NR 70 TC 23 Z9 23 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 2000 VL 62 IS 2 BP 1622 EP 1645 DI 10.1103/PhysRevE.62.1622 PN A PG 24 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 348AC UT WOS:000088960600023 ER PT J AU Daw, CS Finney, CEA Kennel, MB AF Daw, CS Finney, CEA Kennel, MB TI Symbolic approach for measuring temporal "irreversibility" SO PHYSICAL REVIEW E LA English DT Article ID TIME-SERIES DATA; SURROGATE DATA; REVERSIBILITY; NONLINEARITY; DYNAMICS; NONSTATIONARITY; CHAOS; TESTS AB We describe a symbolic approach for measuring temporal "irreversibility" in time-series measurements. Temporal irreversibility is important because it excludes Gaussian linear dynamics and static transformations of such dynamics from the set of possible generating processes. A symbolic method for measuring temporal irreversibility is attractive because it is computationally efficient, robust to noise, and simplifies statistical analysis of confidence limits. We propose a specific algorithm, called "false flipped symbols," for establishing the presence of temporal irreversibility without the need for generating surrogate data. Besides characterizing experimental data, our results are relevant to the question of selecting alternative models. We illustrate our points with numerical model output and experimental measurements. C1 Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Coll Engn, Knoxville, TN 37996 USA. Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. RP Daw, CS (reprint author), Oak Ridge Natl Lab, Engn Technol Div, POB 2009, Oak Ridge, TN 37831 USA. NR 31 TC 44 Z9 53 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 2000 VL 62 IS 2 BP 1912 EP 1921 DI 10.1103/PhysRevE.62.1912 PN A PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 348AC UT WOS:000088960600054 ER PT J AU Moraga, FJ Taleyarkhan, RP Lahey, RT Bonetto, FJ AF Moraga, FJ Taleyarkhan, RP Lahey, RT Bonetto, FJ TI Role of very-high-frequency excitation in single-bubble sonoluminescence SO PHYSICAL REVIEW E LA English DT Article AB The fundamental and tenth harmonics were used to produce stable single-bubble sonoluminescence in water; By varying the phase difference between the harmonics, it was possible to enhance the sonoluminescence light emission by as much as a factor of 2.7 compared with single-frequency excitation. Absolute measurements of the bubble radius evolution were carried out using the two-detector technique. Unlike previous observations, these measurements and complementary fits of the Rayleigh-Plesset equation reveal that the maximum bubble radius does not change significantly with phase angle between the harmonics. Therefore, increased sonoluminescence intensity does not have to correlate with increases in maximum bubble radius prior to collapse. We believe that a more violent bubble collapse rate (driven by the very-high-frequency component) is responsible for the enhanced light emission under this type of mixed excitation. It was further found that the presence of the tenth-harmonic frequency component led to significant enhancements in the stability of the bubble undergoing sonoluminescence. This allowed the bubble to be driven at the fundamental frequency at 2.0 bars pressure amplitudes, which are significantly above often-reported thresholds of 1.4 bar itself, thereby leading to increased levels of light emission (by more than 250%). C1 Rensselaer Polytech Inst, Troy, NY 12180 USA. Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. CNEA, CAB, Inst Balseiro, Bariloche, Rio Negro, Argentina. RP Moraga, FJ (reprint author), Rensselaer Polytech Inst, Troy, NY 12180 USA. NR 10 TC 15 Z9 16 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 2000 VL 62 IS 2 BP 2233 EP 2237 DI 10.1103/PhysRevE.62.2233 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 348AC UT WOS:000088960600089 ER PT J AU Glenzer, SH Fournier, KB Decker, C Hammel, BA Lee, RW Lours, L MacGowan, BJ Osterheld, AL AF Glenzer, SH Fournier, KB Decker, C Hammel, BA Lee, RW Lours, L MacGowan, BJ Osterheld, AL TI Accuracy of K-shell spectra modeling in high-density plasmas SO PHYSICAL REVIEW E LA English DT Article ID X-RAY SPECTROSCOPY; DIELECTRONIC SATELLITE SPECTRA; CONFINEMENT-FUSION PLASMAS; LASER-DRIVEN IMPLOSIONS; ION-ACOUSTIC-WAVES; HELIUM-LIKE IONS; INDIRECTLY DRIVEN; ELECTRON-TEMPERATURE; FILLED MICROBALLOONS; THOMSON SCATTERING AB We present spectroscopic measurements of the helium-like and lithium-like argon emission supported by Thomson scattering diagnostics on gas bag targets. These data provide critical tests of plasma spectroscopic K-shell models. In particular, we have measured the line radiation in the wavelength region of the He-like Ar 1s(2)-1s3l transition (He-beta) that is of interest for density and temperature measurements of plasmas from gas-filled targets (n(e)less than or equal to 10(21) cm(-3)), laser ablation targets (n(e)less than or equal to 10(22) cm(-3)), and inertial confinement fusion capsule implosions (n(e)greater than or equal to 10(24) cm(-3)). The spectra show lithium-like dielectronic satellites on the red wing of the He-beta line that are temperature sensitive and are known to influence the shape of the Stark-broadened line profiles observed from implosions. To examine the kinetics modeling of this complex, i.e., the He-beta and its associated satellites, we have performed experiments in gas bag plasmas at densities of (0.6-1.1) x 10(21) cm(-3) where we independently determine the electron temperature with ultraviolet Thomson scattering. The comparison of the satellite intensities with kinetics modeling shows good agreement for satellites whose upper states are populated by dielectronic capture, but shows discrepancies for inner-shell collisional excited transitions. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. CEA, DAM Ile France, F-91680 Bruyeres Le Chatel, France. RP Glenzer, SH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-437, Livermore, CA 94551 USA. NR 83 TC 28 Z9 32 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 2000 VL 62 IS 2 BP 2728 EP 2738 DI 10.1103/PhysRevE.62.2728 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 348AD UT WOS:000088960800039 ER PT J AU Hurricane, OA Burke, E Maples, S Viswanathan, M AF Hurricane, OA Burke, E Maples, S Viswanathan, M TI Saturation of Richtmyer's impulsive model SO PHYSICS OF FLUIDS LA English DT Article ID MESHKOV INSTABILITY; STABILITY; WAVE AB In this Brief Communication, we use results from two-dimensional simulations to calculate for what product of perturbation wave number (k) and initial amplitude (a(0)) the Richtmyer impulsive model will fail in its prediction of shock wave driven instability growth as a function of initial shock Mach number. For "large" ka(0), we suggest a formula which bounds the maximum value of the ratio of the amplitude growth rate over the interface speed by one minus the ratio of the interface speed and the transmitted shock speed. (C) 2000 American Institute of Physics. [S1070-6631(00)00208-7]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. Harvard Univ, Cambridge, MA 02138 USA. RP Hurricane, OA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 10 TC 3 Z9 3 U1 2 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD AUG PY 2000 VL 12 IS 8 BP 2148 EP 2151 DI 10.1063/1.870462 PG 4 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 331ED UT WOS:000088003600026 ER PT J AU Chen, L Lin, ZH White, R AF Chen, L Lin, ZH White, R TI Excitation of zonal flow by drift waves in toroidal plasmas SO PHYSICS OF PLASMAS LA English DT Article ID TURBULENT TRANSPORT; TOKAMAKS; DRIVEN AB An analytical dispersion relation is derived which shows that, in toroidal plasmas, zonal flows can be spontaneously excited via modulations in the radial envelope of a single-n coherent drift wave, with n the toroidal mode number. Predicted instability features are verified by three-dimensional global gyrokinetic simulations of the ion-temperature-gradient mode. Nonlinear equations for mode amplitudes demonstrate saturation of the linearly unstable pump wave and nonlinear oscillations of the drift-wave intensity and zonal flows, with a parameter-dependent period doubling route to chaos. (C) 2000 American Institute of Physics. [S1070-664X(00)01208-8]. C1 Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Chen, L (reprint author), Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RI chen, liu/I-2297-2013; White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 16 TC 194 Z9 196 U1 1 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3129 EP 3132 DI 10.1063/1.874222 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900001 ER PT J AU Park, J Henins, I Herrmann, HW Selwyn, GS AF Park, J Henins, I Herrmann, HW Selwyn, GS TI Neutral bremsstrahlung measurement in an atmospheric-pressure radio frequency discharge SO PHYSICS OF PLASMAS LA English DT Article AB Neutral bremsstrahlung emission spectrum is measured in an atmospheric-pressure radio frequency (rf) capacitive discharge for a gas mixture of helium (99.5%) and oxygen (0.5%) using a high resolution triple monochromator between 450 and 1000 nm. Good agreement is obtained for spectral variation and absolute intensity between the observed neutral bremsstrahlung and theoretical emissivity calculated using electron-neutral momentum cross sections. Based on a theoretical fitting, the discharge is characterized by a time averaged electron density of 2.9x10(11) cm(-3) and an electron temperature of 1.9 eV for an input power density of 28 W/cm(3). (C) 2000 American Institute of Physics. [S1070-664X(00)03808-8]. C1 Univ Calif Los Alamos Natl Lab, Plasma Phys Lab, Los Alamos, NM 87545 USA. RP Park, J (reprint author), Univ Calif Los Alamos Natl Lab, Plasma Phys Lab, POB 1663, Los Alamos, NM 87545 USA. NR 20 TC 38 Z9 38 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3141 EP 3144 DI 10.1063/1.874220 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900004 ER PT J AU Brizard, AJ AF Brizard, AJ TI Nonlinear bounce-gyrocenter Hamiltonian dynamics in general magnetic field geometry SO PHYSICS OF PLASMAS LA English DT Article ID GUIDING CENTER MOTION; EQUATIONS AB Nonlinear bounce-gyrocenter Hamilton equations for full electromagnetic field fluctuations in general magnetic geometry are derived by the phase-space Lagrangian Lie-perturbation method. These reduced dynamical equations can be used to follow the orbits of magnetically trapped charged particles in the presence of low-frequency electromagnetic fluctuations in magnetic-field geometries suitable for applications in fusion and space plasma physics. (C) 2000 American Institute of Physics. [S1070- 664X(00)01308-2]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Brizard, AJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 4-230, Berkeley, CA 94720 USA. OI Brizard, Alain/0000-0002-0192-6273 NR 18 TC 14 Z9 14 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3238 EP 3246 AR PII [S1070-664X(00)01308-2] DI 10.1063/1.874189 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900016 ER PT J AU Velikovich, AL Davis, J Thornhill, JW Giuliani, JL Rudakov, LI Deeney, C AF Velikovich, AL Davis, J Thornhill, JW Giuliani, JL Rudakov, LI Deeney, C TI Model of enhanced energy deposition in a Z-pinch plasma SO PHYSICS OF PLASMAS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; K-SHELL EMISSION; X-RAY-EMISSION; ARRAY IMPLOSIONS; WIRE NUMBER; POWER; LOADS; TEMPERATURE; SIMULATIONS; GENERATORS AB In numerous experiments, magnetic energy coupled to strongly radiating Z-pinch plasmas exceeds the thermalized kinetic energy, sometimes by a factor of 2-3. An analytical model describing this additional energy deposition based on the concept of macroscopic magnetohydrodynamic (MHD) turbulent pinch heating proposed by Rudakov and Sudan [Phys. Reports 283, 253 (1997)] is presented. The pinch plasma is modeled as a foam-like medium saturated with toroidal "magnetic bubbles" produced by the development of surface m=0 Rayleigh-Taylor and MHD instabilities. As the bubbles converge to the pinch axis, their magnetic energy is converted to thermal energy of the plasma through pdV work. Explicit formulas for the average dissipation rate of this process and the corresponding contribution to the resistance of the load, which compare favorably to the experimental data and simulation results, are presented. The possibility of using this enhanced (relative to Ohmic heating) dissipation mechanism to power novel plasma radiation sources and produce high K-shell yields using long current rise time machines is discussed. (C) 2000 American Institute of Physics. [S1070-664X(00)02808-1]. C1 USN, Res Lab, Radiat Hydrodynam Branch, Div Plasma Phys, Washington, DC 20375 USA. Adv Power Technol Inc, Washington, DC 20037 USA. Sandia Natl Labs, Albuquerque, NM 87545 USA. RP Velikovich, AL (reprint author), USN, Res Lab, Radiat Hydrodynam Branch, Div Plasma Phys, Washington, DC 20375 USA. RI Velikovich, Alexander/B-1113-2009 NR 41 TC 47 Z9 47 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3265 EP 3277 DI 10.1063/1.874192 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900019 ER PT J AU Carreras, BA Lynch, VE Newman, DE Balbin, R Bleuel, J Pedrosa, MA Endler, M van Milligen, B Sanchez, E Hidalgo, C AF Carreras, BA Lynch, VE Newman, DE Balbin, R Bleuel, J Pedrosa, MA Endler, M van Milligen, B Sanchez, E Hidalgo, C TI Intermittency of plasma edge fluctuation data: Multifractal analysis SO PHYSICS OF PLASMAS LA English DT Article ID FULLY-DEVELOPED TURBULENCE; SELF-SIMILARITY; LAYER; MODEL AB Plasma edge fluctuations show a degree of intermittency similar to fluid turbulence. Using fluctuation measurements obtained with Langmuir probe data from two confinement devices, it is shown that plasma fluctuations have a multifractal character over the fluctuation range of scales with intermittency levels comparable to the levels measured in neutral fluid turbulence. In the mesoscale range, that is, for time scales between 10 times the turbulence decorrelation time and plasma confinement time, plasma fluctuations have a structure closer to a monofractal with very low intermittency. (C) 2000 American Institute of Physics. [S1070-664X(00)00308-6]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Alaska, Dept Phys, Fairbanks, AK 99775 USA. Asociac Euratom Ciemat, Madrid 28040, Spain. Max Planck Inst Plasma Phys, Euratom Assoc, D-85740 Garching, Germany. RP Carreras, BA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Sanchez, Edilberto/D-4620-2009; Lynch, Vickie/J-4647-2012; van Milligen, Boudewijn/H-5121-2015; Balbin, Rosa/F-8210-2010 OI Sanchez, Edilberto/0000-0003-1062-7870; Lynch, Vickie/0000-0002-5836-7636; van Milligen, Boudewijn/0000-0001-5344-6274; Balbin, Rosa/0000-0001-5231-1300 NR 16 TC 54 Z9 53 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3278 EP 3287 AR PII [S1070-664X(00)00308-6] DI 10.1063/1.874193 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900020 ER PT J AU Jaeger, EF Berry, LA Batchelor, DB AF Jaeger, EF Berry, LA Batchelor, DB TI Full-wave calculation of sheared poloidal flow driven by high-harmonic ion Bernstein waves in tokamak plasmas SO PHYSICS OF PLASMAS LA English DT Article ID ABSORPTION; CONVERSION; TRANSPORT AB A full-wave, one-dimensional spectral model is developed to study sheared poloidal flow driven by high-harmonic ion Bernstein waves (IBWs) in tokamak plasmas. The local plasma conductivity is corrected to lowest order in rho/L where rho is the ion Larmor radius and L is the equilibrium scale length. This correction takes into account gradients in equilibrium quantities and is necessary for conservation of energy. It is equivalent to the "odd-order derivative" terms in finite difference models. No assumption is made regarding the smallness of the ion Larmor radius relative to wavelength, and results are applicable to all orders in k(perpendicular to)rho where k(perpendicular to) is the perpendicular wave number. Previous numerical results for flow drive have relied on expansions in k(perpendicular to)rho, and are thus limited to cyclotron harmonics of two and below. In this article, we consider higher-harmonic cases corresponding to recent IBW flow drive experiments on the Tokamak Fusion Test Reactor [B. P. LeBlanc, R. E. Bell, S. Bernabei , Phys. Rev. Lett. 82, 331 (1999)] and the Frascati Tokamak Upgrade [R. Cesario, C. Castaldo, V. Pericoli-Ridolfini , "Recent Results of the Ion Bernstein Wave Heating Experiment on FTU," in Proceedings of the 13th Topical Conference on Radio Frequency Power in Plasmas, 1999, Annapolis, MD, edited by S. Bernabei and F. Paoletti (American Institute of Physics, New York, 1999), p. 100]. In these cases, a directly launched high-harmonic IBW is used to drive poloidal flow near the fourth- and fifth-harmonic ion cyclotron layers. Other applications include high-harmonic fast wave heating in low aspect ratio tokamaks such as the National Spherical Torus Experiment [S. M. Kaye, M. Ono, Y.-K. M. Peng , Fusion Technol. 36, 16 (1999)]. (C) 2000 American Institute of Physics. [S1070-664X(00)02008-5]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jaeger, EF (reprint author), Oak Ridge Natl Lab, POB 2009, Oak Ridge, TN 37831 USA. NR 22 TC 35 Z9 36 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3319 EP 3329 DI 10.1063/1.874197 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900024 ER PT J AU Lewandowski, JLV AF Lewandowski, JLV TI Drift wave simulations in stellarator geometry SO PHYSICS OF PLASMAS LA English DT Article ID ANOMALOUS TRANSPORT; INSTABILITIES; TOKAMAKS; MODES; EQUILIBRIA; PLASMAS; SHEAR AB A model, based on gyro-kinetic ions and fluid electrons, to study drift waves in low-beta [beta=(kinetic pressure)/(magnetic pressure)] stellarator plasmas is presented. The model equations are written in straight-field-line coordinates and are valid for arbitrary, fully three-dimensional configurations with closed, nested magnetic surfaces. An implicit method, coupled with a subcycling technique for the electrons, is used to solve the time-dependent, along-the-field-line equations. Numerical calculations are carried out for a three-field-period toroidal heliac. The geometrical effects that enter the model equations are calculated and displayed in physical space using advanced visualization techniques. (C) 2000 American Institute of Physics. [S1070- 664X(00)00208-1]. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lewandowski, JLV (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 33 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3360 EP 3368 AR PII [S1070-664X(00)00208-1] DI 10.1063/1.874200 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900027 ER PT J AU Moody, JD MacGowan, BJ Berger, RL Estabrook, KG Glenzer, SH Kirkwood, RK Kruer, WL Stone, GE Montgomery, DS AF Moody, JD MacGowan, BJ Berger, RL Estabrook, KG Glenzer, SH Kirkwood, RK Kruer, WL Stone, GE Montgomery, DS TI Experimental study of laser beam transmission and power accounting in a large scale length laser plasma SO PHYSICS OF PLASMAS LA English DT Article ID X-RAY SPECTROSCOPY; STIMULATED BRILLOUIN; HOHLRAUM PLASMAS; PHASE PLATES; TARGETS; FUSION; LIGHT; NOVA; FLUCTUATIONS; SCATTERING AB It is shown that the measured laser power transmission through a large scale length, high temperature plasma (which emulates an indirect drive ignition-scale plasma) is in approximate agreement with the simulated transmission provided the simulations account for the power loss due to scattering from laser-plasma instabilities. Detailed accounting of the incident, transmitted, scattered, and absorbed powers is used to infer the likely location in the target where most of the scattering occurs along the incident beam trajectory. This location is near the incident laser side of the target at peak electron temperatures for a range of laser intensities. As a result, the backscattered light measurements at peak electron temperature do not require significant adjustment to account for attenuation of the backscattered light as it propagates out through the plasma. (C) 2000 American Institute of Physics. [S1070-664X(00)01507-X]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Moody, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. OI Montgomery, David/0000-0002-2355-6242 NR 25 TC 9 Z9 16 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3388 EP 3398 AR PII [S1070-664X(00)01507-X] DI 10.1063/1.874218 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900030 ER PT J AU Geraci, AA Whittum, DH AF Geraci, AA Whittum, DH TI Transverse dynamics of a relativistic electron beam in an underdense plasma channel SO PHYSICS OF PLASMAS LA English DT Article ID WAKE-FIELD ACCELERATOR; WAKEFIELD ACCELERATOR; HOSE INSTABILITY; WAVE-BREAKING; AMPLITUDE; STABILITY; SHEATH AB The transverse dynamics of a relativistic electron beam in a plasma less dense than the beam is analyzed, with particular attention to the electron-hose instability as it appears in a plasma channel of finite radius. A comparison is made between analytic asymptotic forms, linearized "beam break-up" simulations, and particle-in-cell simulations. The analysis provides a framework for the interpretation of projected and time-resolved diagnostics in such a system. Examples used for illustration correspond to parameters of an experiment in progress, employing a 30 GeV electron beam in a 1.5 m plasma cell, with the amplification of beam-centroid offsets on the order of 10(0)-10(2)x, depending on experimental settings. (C) 2000 American Institute of Physics. [S1070-664X(00)04907-7]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 33 TC 11 Z9 11 U1 4 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3431 EP 3440 AR PII [S1070-664X(00)04907-7] DI 10.1063/1.874207 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900035 ER PT J AU Kitamura, H Murillo, MS Weisheit, JC AF Kitamura, H Murillo, MS Weisheit, JC TI Ionic excitation in dense, two-component plasmas: A nonperturbative approach SO PHYSICS OF PLASMAS LA English DT Article AB A nonperturbative formulation of atomic collisional excitation rates in dense plasmas is developed on the basis of the equations of motion for density matrices in a stochastic potential. This model treats the strong scattering between the atom and plasma particles through the many-body correlation functions describing plasma density fluctuations, which are decomposed into the products of dynamic structure factors within the decorrelation approximation and then are summed to infinite order. A simple analytic solution to the density matrix equation is obtained for two-level atoms. The electron-induced transition of a hydrogen-like ion in dense hydrogen plasma is studied as an example. It is demonstrated that, when the plasma density is sufficiently high, low-frequency ion-density fluctuations influence the electron dynamics and thereby cause coherent excitation between close-lying atomic states. The resultant time evolution of the atomic level population differs considerably from the prediction of one-component plasma collisional rate equations based on first-order perturbation theory (Born approximation). (C) 2000 American Institute of Physics. [S1070-664X(00)02508-8]. C1 Univ Tokyo, Inst Solid State Phys, Chiba 2778581, Japan. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Rice Univ, Dept Space Phys & Astron, Houston, TX 77251 USA. RP Univ Tokyo, Inst Solid State Phys, Chiba 2778581, Japan. EM kitamura@issp.u-tokyo.ac.jp NR 25 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 2000 VL 7 IS 8 BP 3441 EP 3447 AR PII [S1070-664X(00)02508-8] DI 10.1063/1.874208 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 335JG UT WOS:000088239900036 ER PT J AU Qian, YZ Wasserburg, GJ AF Qian, YZ Wasserburg, GJ TI Stellar abundances in the early galaxy and two r-process components SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE r-process nucleosynthesis; abundances in metal-poor stars; galactic chemical evolution ID METAL-POOR STARS; GALACTIC CHEMICAL EVOLUTION; NEUTRINO-DRIVEN WINDS; GIANT BRANCH STARS; DIVERSE SUPERNOVA SOURCES; EARLY SOLAR-SYSTEM; CORE FORMATION; PROCESS NUCLEOSYNTHESIS; PROTONEUTRON STARS; CS-22892-052 AB We present quantitative predictions for the abundances of r-process elements in stars formed very early in the Galactic history using a phenomenological two-component r-process model based on the I-129 and Hf-182 inventory in the early solar system. This model assumes that a standard mass of the ISM dilutes the debris from an individual supernova. High-frequency supernova H events and low-frequency supernova L events are proposed in the model with characteristics determined by the meteoritic data on I-129 and Hf-182. The yields in an H or L event are obtained from these characteristics and the solar r-process abundances under the assumption that the yield template for the high-mass (A > 130) nuclei associated with W-182 Or the low-mass (A less than or equal to 130) nuclei associated with I-127 is the same for both the H and L events and follows the corresponding solar r-pattern in each mass region. This choice of the yield templates is justified by the regular solar-like r-process abundance pattern for Ba and higher atomic numbers observed in very metal-poor stars. The abundance of Eu, not Fe, is proposed as a key guide to the age of very metal-poor stars, We predict that stars with loge(Eu) = -2.98 to -2.22 were formed from an ISM contaminated most likely by a single H event within the first similar to 10(7) yr of the Galactic history and should have an Ag/Eu abundance ratio less than the corresponding solar r-process value by a factor of at least 10. Many of the very metal-poor stars observed so far are considered here to have been formed from an ISM contaminated by many (similar to 10) r-process events. Stars formed from an ISM contaminated only by a pure L event would have an Ag/Eu ratio higher than the corresponding solar r-process value but would be difficult to find due to the low-frequency of the L events. However, variations in the relative abundances of the low- and high-mass regions should be detectable in very metal-poor stars. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. CALTECH, Div Geol & Planetary Sci, Lunat Asylum, Pasadena, CA 91125 USA. RP Qian, YZ (reprint author), Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RI WASSERBURG, GERALD /F-6247-2011 NR 51 TC 51 Z9 52 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD AUG PY 2000 VL 333 IS 1-6 BP 77 EP 108 DI 10.1016/S0370-1573(00)00017-X PG 32 WC Physics, Multidisciplinary SC Physics GA 336AW UT WOS:000088280600008 ER PT J AU Frieman, JA Szalay, AS AF Frieman, JA Szalay, AS TI Large-scale structure: entering the precision era SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review ID COLD DARK-MATTER; COSMOLOGICAL DENSITY PERTURBATIONS; INFLATIONARY UNIVERSE SCENARIO; 3-POINT CORRELATION-FUNCTION; GALAXY CORRELATION-FUNCTIONS; CAMPANAS REDSHIFT SURVEY; LYMAN-BREAK GALAXIES; POWER SPECTRUM; FLUCTUATIONS; STATISTICS AB In recent years, the framework for a plausible theory of large-scale structure formation has emerged: primordial, quasi-scale-invariant perturbations from inflation, which subsequently grow by gravitational instability in a universe with a substantial component of cold dark matter. At the same time, with the development of large galaxy surveys, the precision of statistical measurements of large-scale structure has begun to improve rapidly. In the near future, a new generation of surveys, along with cosmic microwave background missions and other cosmological probes, will probe this structure formation paradigm and ultimately provide clues to the dynamics of inflation itself. This chapter highlights recent progress and expected future developments in our understanding of large-scale structure and in testing the inflationary scenario for its formation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM frieman@fnal.gov NR 85 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD AUG PY 2000 VL 333 IS 1-6 BP 215 EP 232 DI 10.1016/S0370-1573(00)00045-4 PG 18 WC Physics, Multidisciplinary SC Physics GA 336AW UT WOS:000088280600015 ER PT J AU Smoot, GF AF Smoot, GF TI CMB anisotropy experiments SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE cosmic microwave background radiation; cosmology; Schramm ID DIFFERENTIAL MICROWAVE RADIOMETER; COSMIC BACKGROUND-RADIATION; NONCOSMOLOGICAL SIGNAL CONTRIBUTIONS; 2-YEAR SKY MAPS; STAR MU PEGASI; COBE DMR; SCALE ANISOTROPY; ANGULAR SCALES; EXTRAGALACTIC OBJECTS; STATISTICAL-ANALYSIS AB Anisotropies in the cosmic microwave background (CMB) encode information about the evolution and development of the universe. Quality observations of CMB anisotropies can provide a very strong test of cosmological models and provide high precision determination of major cosmological parameters. This paper provides a review of the COBE DMR results, the current status of the measurements of the CMB anisotropy power spectrum and then focuses current and future programs including both suborbital observations and the two selected satellite missions: the NASA MidEX mission MAP and the ESA M3 mission Max Planck Surveyor. This review includes both a description of the experimental programs and the expected quality level of results. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Smoot, GF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM smoot@astro.1bl.gov NR 121 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD AUG PY 2000 VL 333 IS 1-6 BP 269 EP 308 DI 10.1016/S0370-1573(00)00026-0 PG 40 WC Physics, Multidisciplinary SC Physics GA 336AW UT WOS:000088280600018 ER PT J AU Turner, MS AF Turner, MS TI The dark side of the universe: from Zwicky to accelerated expansion SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review ID BIG-BANG NUCLEOSYNTHESIS; STRING-DOMINATED UNIVERSE; COSMOLOGICAL CONSTANT; SUPERNOVAE; ENERGY; DEUTERIUM; COMPONENT; MATTER; LAMBDA; OMEGA AB More than 60 years ago Zwicky made the case that the great clusters of galaxies are held together by the gravitational force of unseen (dark) matter. Today, the case is stronger and more precise: dark, nonbaryonic matter accounts for 30 +/- 7% of the critical mass density, with baryons (most of which are dark) contributing only 4.5 +/- 1% of the critical density. The large-scale structure that exists in the universe indicates that the bulk of the nonbaryonic dark matter must be cold (slowly moving particles). The SuperKamiokande detection of neutrino oscillations shows that particle dark matter, in the form of massive neutrinos, actually exists and accounts for as much mass as bright stars. An important threshold has been crossed; particle dark matter is no longer hypothetical. Over the past few years a case has developed for dark energy. This dark, relativistic component contributes about 80 +/- 20% of the critical density and is characterized by very negative pressure (p(X) < - 0.6 rho(X)). Consistent with this picture of dark energy and dark matter are measurements of CMB anisotropy that indicate that, matter and energy together account for the critical density (within 10%). Fundamental physics beyond the standard model is implicated in both the dark matter and dark energy puzzles: new fundamental particles (e.g., axion or neutralino) and new forms of relativistic energy (e.g., vacuum energy or a light scalar field). Dark matter and dark energy are central issues in both cosmology and particle physics. Over the next two decades a flood of precision cosmological observations and laboratory experiments will shed light on the dark side of the universe. As they do they will advance our understanding of both the universe and the laws of physics that govern it. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Chicago, Dept Astron & Astrophys, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Enrico Fermi Inst, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Turner, MS (reprint author), Univ Chicago, Dept Astron & Astrophys, Enrico Fermi Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 51 TC 60 Z9 60 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD AUG PY 2000 VL 333 IS 1-6 BP 619 EP 635 DI 10.1016/S0370-1573(00)00040-5 PG 17 WC Physics, Multidisciplinary SC Physics GA 336AW UT WOS:000088280600033 ER PT J AU Isgur, N AF Isgur, N TI Feynman brainwashed? SO PHYSICS TODAY LA English DT Letter C1 Jefferson Lab, Newport News, VA USA. RP Isgur, N (reprint author), Jefferson Lab, Newport News, VA USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD AUG PY 2000 VL 53 IS 8 BP 11 EP 11 DI 10.1063/1.1310103 PN 1 PG 1 WC Physics, Multidisciplinary SC Physics GA 339XE UT WOS:000088502500003 ER PT J AU Crease, RP AF Crease, RP TI The dangers of Voodoo Science SO PHYSICS WORLD LA English DT Editorial Material C1 SUNY Stony Brook, Dept Philosophy, Stony Brook, NY USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Crease, RP (reprint author), SUNY Stony Brook, Dept Philosophy, Stony Brook, NY USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD AUG PY 2000 VL 13 IS 8 BP 19 EP 19 PG 1 WC Physics, Multidisciplinary SC Physics GA 342ET UT WOS:000088632800018 ER PT J AU Weiss, S AF Weiss, S TI Shattering the diffraction limit of light: A revolution in fluorescence microscopy? SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Editorial Material ID RESOLUTION; EXCITATION; 2-PHOTON C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Weiss, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI weiss, shimon/B-4164-2009 OI weiss, shimon/0000-0002-0720-5426 NR 18 TC 24 Z9 24 U1 0 U2 6 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 AUG 1 PY 2000 VL 97 IS 16 BP 8747 EP 8749 DI 10.1073/pnas.97.16.8747 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 341UL UT WOS:000088608000001 PM 10922028 ER PT J AU Roeske, F Souers, PC AF Roeske, F Souers, PC TI Corner turning of detonation waves in an HMX-based paste explosive SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article AB Detonation wave profiles have been determined for RX-08-HD (74% HMX paste) loaded in 3 mm square troughs after turning both acute 90 degrees bends and bends with a 1.5 mm inner radius turn and a 4.5 mm outer radius. The explosive troughs were confined with either lucite or copper. We show that the shape of the detonation wavefront can be explained in terms of a Huygens' construction from the leading point to the outer radius. Turbulent behavior occurs between the leading point and the inner edge. The turbulence appears enhanced for the curved samples with copper confinement. The distance the detonation wave has to travel past the turn in order to regain its original symmetry was found to be governed by an exponential time constant of 0.6 mu s. Analysis suggests that the leading point alone stays at the straight-ahead detonation velocity throughout the turn. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Roeske, F (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 0 Z9 0 U1 1 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD AUG PY 2000 VL 25 IS 4 BP 172 EP 178 PG 7 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA 363FQ UT WOS:000089824800003 ER PT J AU Buchko, GW Rozek, A Kanda, P Kennedy, MA Cushley, RJ AF Buchko, GW Rozek, A Kanda, P Kennedy, MA Cushley, RJ TI Structural studies of a baboon (Papio sp.) plasma protein inhibitor of cholesteryl ester transferase SO PROTEIN SCIENCE LA English DT Article DE apolipoproteins; atherosclerosis; CD; fluorescence spectroscopy; lipoproteins; NMR; reverse cholesterol transport ID APOLIPOPROTEIN-A-I; SODIUM DODECYL-SULFATE; MEMBRANE-MIMETIC ENVIRONMENTS; HIGH-DENSITY-LIPOPROTEINS; SECONDARY STRUCTURE; NMR-SPECTROSCOPY; TRANSGENIC MICE; H-1-NMR SPECTRA; LIPID TRANSFER; C-I AB A 38-residue protein associated with cholesteryl ester transfer inhibition has been identified in baboons (Papio sp.). The cholesteryl ester transfer inhibitor protein (CETIP) corresponds to the N-terminus of baboon apoC-I. Relative to CETIP, baboon apoC-I is a weak inhibitor of baboon cholesteryl ester transferase (CET). To study the structural features responsible for CET inhibition, CETIP was synthesized by solid-phase methods. Using sodium dodecyl sulfate (SDS) to model the lipoprotein environment, the solution structure of CETIP was probed by optical and H-1 NMR spectroscopy, Circular dichroism data show that the: protein lacks a well-defined structure in water but, upon the addition of SDS, becomes helical (56%). A small blue shift of 8 nm was observed in the intrinsic tryptophan fluorescence of CETIP in the presence of saturating amounts of SDS, suggesting that tryptophan-23 is not buried deeply in the lipid environment. The helical nature of CETIP in the presence of SDS was confirmed by upfield H-1(alpha) secondary shifts and an average solution structure determined by distance geometry/simulated annealing calculations using 476 NOE-based distance restraints. The backbone (N-C-alpha-C=O) root-mean-square deviation of an ensemble of 17 out of 25 calculated structures superimposed on the average structure was 1.06 +/- 0.30 Angstrom using residues V4-P35 and 0.51 +/- 0.17 Angstrom using residues A7-S32, Although the side-chain orientations fit the basic description of a class A amphipathic helix, both intramolecular salt bridge formation and "snorkeling" of basic side chains toward the polar face play minor, if any, roles in stabilizing the lipid-bound amphipathic structure. Conformational features of the calculated structures for CETIP are discussed relative to models of CETIP inhibition of cholesteryl ester transferase. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Simon Fraser Univ, Inst Mol Biol & Biochem, Burnaby, BC V5A 1S6, Canada. SW Fdn Biomed Res, Dept Virol & Immunol, San Antonio, TX 78228 USA. RP Buchko, GW (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999,MSIN K8-98, Richland, WA 99352 USA. RI Buchko, Garry/G-6173-2015 OI Buchko, Garry/0000-0002-3639-1061 NR 86 TC 3 Z9 4 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD AUG PY 2000 VL 9 IS 8 BP 1548 EP 1558 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 347FR UT WOS:000088917400013 PM 10975576 ER PT J AU Holden, NE Hoffman, DC AF Holden, NE Hoffman, DC TI Spontaneous fission half-lives for ground-state nuclides (Technical Report) SO PURE AND APPLIED CHEMISTRY LA English DT Review ID ENHANCED NUCLEAR-STABILITY; DECAY PROPERTIES; CLUSTER DECAY; ALPHA-DECAY; RADIOACTIVE DECAY; BRANCHING RATIOS; CROSS-SECTIONS; ISOTOPES; IDENTIFICATION; CONSTANT AB Measurements of the spontaneous fission half-lives of nuclides of elements Z = 82 through 109 have been compiled (cutoff date of April 1998) and evaluated. Recommended values are tabulated along with total half-lives. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Holden, NE (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 229 TC 97 Z9 98 U1 0 U2 7 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD AUG PY 2000 VL 72 IS 8 BP 1525 EP 1562 DI 10.1351/pac200072081525 PG 38 WC Chemistry, Multidisciplinary SC Chemistry GA 386RX UT WOS:000166076300008 ER PT J AU McCoy, FW Heiken, G AF McCoy, FW Heiken, G TI Tsunami generated by the Late Bronze Age eruption of Thera (Santorini), Greece SO PURE AND APPLIED GEOPHYSICS LA English DT Review DE tsunami; volcanic eruptions; tephra; pyroclastic surges; pyroclastic flows; debris flows; lahar; calderas; tsunami deposits; pumice; ash; Late Bronze Age ID PYROCLASTIC FLOWS; MINOAN ERUPTION; AEGEAN REGION; 1883 ERUPTION; HELLENIC ARC; NILE DELTA; SEA-LEVEL; TECTONICS; KRAKATAU; TEPHRA AB Tsunami were generated during the Late Bronze Age (LBA) eruption of the island of Thera, in the southern Aegean Sea, by both caldera collapse, and by the entry of pyroclastic surges/flows and lahars/debris flows into the sea. Tsunami generated by caldera collapse propagated to the west producing deep-sea sedimentary deposits in the eastern Mediterranean Sea known as homogenites; open-ocean wave heights of about 1.9-17 m are estimated. Tsunami generated by the entry of pyroclastic flows/surges and lahars/debris flows into the sea propagated in all directions around the island; wave heights along coastal areas were about 7-12 m as estimated from newly identified tsunami deposits on eastern Thera as well as from pumice deposits found at archaeological sites on northern and eastern Crete. C1 Univ Hawaii, Windward Community Coll, Kaneohe, HI 96744 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP McCoy, FW (reprint author), Univ Hawaii, Windward Community Coll, Kaneohe, HI 96744 USA. EM fmccoy@hawaii.edu NR 116 TC 57 Z9 57 U1 0 U2 92 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD AUG PY 2000 VL 157 IS 6-8 BP 1227 EP 1256 DI 10.1007/s000240050024 PG 30 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 347NY UT WOS:000088937100016 ER PT J AU Abdallah, J Skobelev, IY Faenov, AY Magunov, AI Pikuz, TA Flora, F Bollanti, S Di Lazzaro, P Letardi, T Burattini, E Grilli, A Reale, A Palladino, L Tomassetti, G Scafati, A Reale, L AF Abdallah, J Skobelev, IY Faenov, AY Magunov, AI Pikuz, TA Flora, F Bollanti, S Di Lazzaro, P Letardi, T Burattini, E Grilli, A Reale, A Palladino, L Tomassetti, G Scafati, A Reale, L TI Spectra of multiply charged hollow ions the plasma produced by a short-wavelength nanosecond laser SO QUANTUM ELECTRONICS LA English DT Article ID EMISSION; ATOMS AB Complex spectral structures located between the resonance lines of H- and He-like MgXII and MgXI ions were recorded in experiments on plasma heating by the radiation of a low-power short-wavelength excimer XeCl laser (12-ns pulses with an energy of 2 J). The above spectral structures were shown to arise from transitions in the so-called hollow multicharged ions, i.e., in ions with an empty Is-shell, which were previously observed in laser produced plasmas only with ultrahigh-power femto- and picosecond laser facilities having extremely high-contrast laser pulses. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. VNIIFTRI, Ctr Data Multicharged Ions Spectra, Mendeleevo 141570, Moscow Oblast, Russia. ENEA, INN Fis, I-00044 Frascati, RM, Italy. Ist Nazl Fis Nucl, I-00044 Frascati, Rome, Italy. Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy. Univ Aquila, Ist Nazl Fis Nucl, Gc LNGS, I-67100 Laquila, Italy. RP Abdallah, J (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Tomassetti, Giuseppe/F-3211-2010; OI Tomassetti, Giuseppe/0000-0001-8801-7461; PALLADINO, LIBERO/0000-0001-5291-6246 NR 14 TC 15 Z9 15 U1 0 U2 0 PU TURPION LTD PI LETCHWORTH PA TURPIN DISTRIBUTION SERVICES, BLACKHORSE RD, LETCHWORTH SG6 1HN, HERTS, ENGLAND SN 1063-7818 J9 QUANTUM ELECTRON+ JI Quantum Electron. PD AUG PY 2000 VL 30 IS 8 BP 694 EP 702 DI 10.1070/QE2000v030n08ABEH001793 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 373TF UT WOS:000165304500008 ER PT J AU Macek, JH Ovchinnikov, SY Khrebtukov, DB AF Macek, JH Ovchinnikov, SY Khrebtukov, DB TI Harmonic oscillator Green's function SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on High Energy Interactions of Photons and Electrons with Atoms, A Retrospective of the Work of Richard Pratt CY OCT 30, 1999 CL UNIV PITTSBURGH, PITTSBURGH, PENNSYLVANIA HO UNIV PITTSBURGH DE Green's function; harmonic oscillator; collisions ID COLLISIONS; ELECTRONS AB The Green's function for the harmonic oscillator in three dimensions plays an important role in the theory of atomic collisions. One representation of low-energy ion-atom collisions involves harmonic oscillator potentials. A closed-form expression for the harmonic oscillator Green's function, needed to exploit this representation, is derived. This expression is similar to the expression for the Coulomb Green's function obtained by Hostler and Pratt. Calculations of electron distributions for a model system of ion-atom collisions are reported to illustrate the theory. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Macek, JH (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RI Ovchinnikov, Serguei/C-4994-2014 NR 8 TC 3 Z9 4 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD AUG PY 2000 VL 59 IS 2 BP 149 EP 153 DI 10.1016/S0969-806X(00)00285-1 PG 5 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 340HR UT WOS:000088527500006 ER PT J AU Kissel, L AF Kissel, L TI RTAB: the Rayleigh scattering database SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on High Energy Interactions of Photons and Electrons with Atoms, A Retrospective of the Work of Richard Pratt CY OCT 30, 1999 CL UNIV PITTSBURGH, PITTSBURGH, PENNSYLVANIA HO UNIV PITTSBURGH ID ATOMIC FORM-FACTORS; ELASTIC-SCATTERING; CROSS-SECTIONS; GAMMA-RAYS; X-RAYS; APPROXIMATION; ENERGIES; PROGRAM AB Systematic tabulations of differential scattering cross sections for all atoms for photon energies 0.0543-2754.1 keV in various approximations are being made available, with a focus on the S-matrix approach of Kissel and Pratt. New tabulations are also being made available of: anomalous scattering factors for 0-10 MeV; total-atom shell and subshell form factors; bound-bound oscillator strengths; total-atom, shell and subshell photoeffect cross sections; and Dirac-Slater potentials. Accurate interpolation of S-matrix cross sections to intermediate energies is investigated. Selected computer codes that generate or use these data are described. Published by Elsevier Science Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Sci Comp & Commun Dept, Phys Directorate, Div 5, Livermore, CA 94551 USA. RP Kissel, L (reprint author), Univ Calif Lawrence Livermore Natl Lab, Sci Comp & Commun Dept, Phys Directorate, Div 5, Livermore, CA 94551 USA. NR 37 TC 58 Z9 58 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD AUG PY 2000 VL 59 IS 2 BP 185 EP 200 DI 10.1016/S0969-806X(00)00290-5 PG 16 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 340HR UT WOS:000088527500011 ER PT J AU Reilly, CA AF Reilly, CA TI Miriam Dorothy (Posner) Finkel (1916-1999) - In memoriam SO RADIATION RESEARCH LA English DT Biographical-Item C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Reilly, CA (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 2000 VL 154 IS 2 BP 224 EP 226 PG 3 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 340TK UT WOS:000088550900017 ER PT J AU Budker, D Rochester, SM Yashchuk, VV AF Budker, D Rochester, SM Yashchuk, VV TI Obtaining frequency markers of variable separation with a spherical mirror Fabry-Perot interferometer SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A compact (L approximate to 5 cm) spherical Fabry-Perot interferometer with adjustable mirror spacing is used to produce interference fringes with frequency separation (c/2L)/N, N less than or similar to 20. These fringes are used as frequency markers in a Doppler-free saturation spectroscopy experiment. The conditions for observation of the fringes are discussed in terms of the eigenmodes of the cavity with high transverse indices. (C) 2000 American Institute of Physics. [S0034- 6748(00)02508-9]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. BP Konstantinov Nucl Phys Inst, Gatchina 188350, Russia. RP Budker, D (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Budker, Dmitry/F-7580-2016 OI Budker, Dmitry/0000-0002-7356-4814 NR 8 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 2000 VL 71 IS 8 BP 2984 EP 2987 DI 10.1063/1.1304879 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 344XW UT WOS:000088787200003 ER PT J AU Fehl, DL Biggs, F Chandler, GA Stygar, WA AF Fehl, DL Biggs, F Chandler, GA Stygar, WA TI Spectral resolution for a five-element, filtered, x-ray detector array using the method of Backus and Gilbert SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LINEAR INVERSE PROBLEMS; Z-PINCH EXPERIMENTS; DISCRETE-DATA; DIAGNOSTICS; ABSOLUTE; PLASMAS; POWER AB The generalized method of Backus and Gilbert (BG) is described and applied to the inverse problem of obtaining the spectrum from a five-channel, filtered array of x-ray detectors. This diagnostic is routinely fielded on the Z facility at Sandia National Laboratories to study soft x-ray photons (similar to 100-2300 eV), emitted by high density Z-pinch plasmas. The BG method defines spectral resolution limits on the system of response functions that are in good agreement with a classical unfold method, based on a histogram representation of the source spectrum. The resolution so defined is independent of the source spectrum. For noise-free, simulated data the BG approximating function is also in reasonable agreement with the source spectrum (150 eV blackbody) and the unfolded spectrum. This function may be used as an initial trial function for iterative methods or a regularization model. (C) 2000 American Institute of Physics. [S0034-6748(00)01508-2]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Fehl, DL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM dlfehl@sandia.gov NR 31 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 2000 VL 71 IS 8 BP 3072 EP 3079 AR PII [S0034-6748(00)01508-2] DI 10.1063/1.1304869 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 344XW UT WOS:000088787200018 ER PT J AU Hertwich, EG McKone, TE Pease, WS AF Hertwich, EG McKone, TE Pease, WS TI A systematic uncertainty analysis of an evaluative fate and exposure model SO RISK ANALYSIS LA English DT Article DE multimedia modeling; uncertainty; variability; potential dose; toxics release inventory; life-cycle assessment ID CANCER POTENCY FACTORS; FUGACITY MODEL; AIR-POLLUTION; RISK; CHEMICALS; DISTRIBUTIONS; VARIABILITY; INFORMATION; CLASSIFICATION; CHLOROFORM AB Multimedia fate and exposure models are widely used to regulate the release of toxic chemicals, to set cleanup standards for contaminated sites, and to evaluate emissions in life-cycle assessment. CalTOX, one of these models, is used to calculate the potential dose, an outcome that is combined with the toxicity of the chemical to determine the Human Toxicity Potential (HTP), used to aggregate and compare emissions. The comprehensive assessment of the uncertainty in the potential dose calculation in this article serves to provide the information necessary to evaluate the reliability of decisions based on the HTP. A framework for uncertainty analysis in multimedia risk assessment is proposed and evaluated with four types of uncertainty. Parameter uncertainty is assessed through Monte Carlo analysis. The variability in landscape parameters is assessed through a comparison of potential dose calculations for different regions in the United States. Decision rule uncertainty is explored through a comparison of the HTP values under open and closed system boundaries. Model uncertainty is evaluated through two case studies, one using alternative formulations for calculating the plant concentration and the other testing the steady state assumption for wet deposition. This investigation shows that steady state conditions for the removal of chemicals from the atmosphere are not appropriate and result in an underestimate of the potential dose for 25% of the 336 chemicals evaluated. C1 Univ Calif Berkeley, Energy & Resources Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Hertwich, EG (reprint author), Norwegian Univ Sci & Technol, Prod Design & Ind Ecol Programme, Kolbjorn Hejes Vei 2B, N-7491 Trondheim, Norway. OI Hertwich, Edgar/0000-0002-4934-3421 NR 68 TC 50 Z9 52 U1 1 U2 16 PU BLACKWELL PUBL LTD PI OXFORD PA 108 COWLEY RD, OXFORD OX4 1JF, OXON, ENGLAND SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 2000 VL 20 IS 4 BP 439 EP 454 DI 10.1111/0272-4332.204043 PG 16 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA 361VL UT WOS:000089744900004 PM 11051069 ER PT J AU Stark, PC Mullen, KI Banton, K Russotti, R Soran, D Kuske, CR AF Stark, PC Mullen, KI Banton, K Russotti, R Soran, D Kuske, CR TI Pre-PCR DNA quantitation of soil and sediment samples: method development and instrument design SO SOIL BIOLOGY & BIOCHEMISTRY LA English DT Article DE DNA quantitation; fluorescence; UV/Vis absorption; PicoGreen; field-portable; polymerase chain reaction; humic materials ID POLYMERASE CHAIN-REACTION; BACTERIAL-DNA; RAPID METHOD; AMPLIFICATION; SEPARATION; ASSAY; CELLS AB A simple and straightforward method for the quantitation of dsDNA in soil and sediment matrices has been developed to support rapid, in-the-field PCR analysis of environmental samples. This method uses PicoGreen nucleic acid stain, and a combination of UV/Vis and fluorescence spectroscopy, to quantitate dsDNA in the presence of interfering humic materials. The practical utility of this approach is that it compliments a seven-step DNA extraction procedure for environmental samples. The DNA quantitation method is utilized twice during the extraction procedure. Once, prior to a micro-spin column procedure to maximize the amount of DNA extracted, and a second time, just prior to PCR to optimize the PCR reaction conditions, A field-portable, assay-specific instrument has been developed based on this methodology. Software for this instrument steps the analyst through the experimental procedure, and has been designed such that a minimum of technical expertise is required to perform the assay. Initial data obtained from the prototype unit indicates that this instrument compares with commercial instrumentation in terms of detection limit and sensitivity. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Environm Safety & Hlth Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Optisci Inc, Tyngsboro, MA 01879 USA. RP Stark, PC (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 14 TC 9 Z9 9 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-0717 J9 SOIL BIOL BIOCHEM JI Soil Biol. Biochem. PD AUG PY 2000 VL 32 IS 8-9 BP 1101 EP 1110 DI 10.1016/S0038-0717(00)00020-1 PG 10 WC Soil Science SC Agriculture GA 341DE UT WOS:000088575100007 ER PT J AU Tidwell, VC Wilson, JL AF Tidwell, VC Wilson, JL TI Heterogeneity, permeability patterns, and permeability upscaling: Physical characterization of a block of Massillon sandstone exhibiting nested scales of heterogeneity SO SPE RESERVOIR EVALUATION & ENGINEERING LA English DT Article ID HYDRAULIC CONDUCTIVITY; SPATIAL VARIABILITY; VOLCANIC TUFF; FLOW; TRANSPORT; FIELDS AB Over 75,000 permeability measurements were collected from a meter-scale block of Massillon sandstone, characterized by conspicuous crossbedding that forms two distinct nested scales of heterogeneity. With the aid of a gas minipermeameter, spatially exhaustive fields of permeability data were acquired at each of five different sample supports (i.e., sample volumes) from each block face. These data provide a unique opportunity to physically investigate the relationship between the multiscale cross-stratified attributes of the sandstone and the corresponding statistical characteristics of the permeability. These data also provide quantitative physical information concerning the permeability upscaling of a complex heterogeneous medium. Here, a portion of the data taken from a single block face cut normal to stratification is analyzed. The results indicate a strong relationship between the calculated summary statistics and the cross-stratified structural features visibly evident in the sandstone sample. Specifically, the permeability fields and semivariograms are characterized by two nested scales of heterogeneity, including a large-scale structure defined by the cross-stratified sets (delineated by distinct bounding surfaces) and a small-scale structure defined by the low-angle cross-stratification within each set. The permeability data also provide clear evidence of upscaling. That is, each calculated summary statistic exhibits distinct and consistent trends with increasing sample support. Among these trends are an increasing mean, decreasing variance, and an increasing semivariogram range. The results also clearly indicate that the different scales of heterogeneity upscale differently, with the small-scale structure being preferentially filtered from the data while the large-scale structure is preserved. Finally, the statistical and upscaling characteristics of individual cross-stratified sets were found to be very similar because of their shared depositional environment; however, some differences were noted that are likely the result of minor variations in the sediment load and/or flow conditions between depositional events. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA. RP Tidwell, VC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 50 TC 40 Z9 41 U1 2 U2 4 PU SOC PETROLEUM ENG PI RICHARDSON PA 222 PALISADES CREEK DR,, RICHARDSON, TX 75080 USA SN 1094-6470 J9 SPE RESERV EVAL ENG JI SPE Reserv. Eval. Eng. PD AUG PY 2000 VL 3 IS 4 BP 283 EP 291 PG 9 WC Energy & Fuels; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA 345DM UT WOS:000088800200001 ER PT J AU Fredrich, JT Arguello, JG Deitrick, GL de Rouffignac, EP AF Fredrich, JT Arguello, JG Deitrick, GL de Rouffignac, EP TI Geomechanical modeling of reservoir compaction, surface subsidence, and casing damage at the Belridge diatomite field SO SPE RESERVOIR EVALUATION & ENGINEERING LA English DT Article AB Geologic, and historical well failure, production, and injection data were analyzed to guide development of three-dimensional geomechanical models of the Belridge diatomite field, California. The central premise of the numerical simulations is that spatial gradients in pore pressure induced by production and injection in a low permeability reservoir may perturb the local stresses and cause subsurface deformation sufficient to result in well failure. Time-dependent reservoir pressure fields that were calculated from three-dimensional black oil reservoir simulations were coupled unidirectionally to three-dimensional nonlinear finite element geomechanical simulations. The reservoir models included nearly 100,000 gridblocks (100 to 200 wells), and covered nearly 20 years of production and injection. The geomechanical models were meshed from structure maps and contained more than 300,000 nodal points. Shear strain localization along weak bedding planes that causes casing doglegs in the field was accommodated in the model by contact surfaces located immediately above the reservoir and at two locations in the overburden. The geomechanical simulations are validated by comparison of the predicted surface subsidence with field measurements, and by comparison of predicted deformation with observed casing damage. Additionally, simulations performed for two independently developed areas at South Belridge, Sees. 33 and 29, corroborate their different well failure histories. The simulations suggest the three types of casing damage observed, and show that, although water injection has mitigated surface subsidence, it can, under some circumstances, increase the lateral gradients in effective stress that in turn can accelerate subsurface horizontal motions. Geomechanical simulation is an important reservoir management tool that can be used to identify optimal operating policies to mitigate casing damage for existing field developments, and applied to incorporate the effect of well failure potential in economic analyses of alternative infilling and development options. C1 Sandia Natl Labs, Geophys Technol Dept, Albuquerque, NM 87185 USA. Shell Int Explorat & Prod Co, Houston, TX USA. RP Fredrich, JT (reprint author), Sandia Natl Labs, Geophys Technol Dept, POB 5800, Albuquerque, NM 87185 USA. NR 21 TC 36 Z9 38 U1 1 U2 6 PU SOC PETROLEUM ENG PI RICHARDSON PA 222 PALISADES CREEK DR,, RICHARDSON, TX 75080 USA SN 1094-6470 J9 SPE RESERV EVAL ENG JI SPE Reserv. Eval. Eng. PD AUG PY 2000 VL 3 IS 4 BP 348 EP 359 PG 12 WC Energy & Fuels; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA 345DM UT WOS:000088800200009 ER PT J AU Rusak, DA Anderson, JE Kunhardt, EE Wilkerson, CW AF Rusak, DA Anderson, JE Kunhardt, EE Wilkerson, CW TI Optogalvanic and pseudosonic wave spectroscopies in oscillating d.c. discharges SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE optogalvanic spectroscopy; pseudosonic wave spectroscopy; d.c. discharge; oscillating discharge; plasma waves; power spectra ID HOLLOW-CATHODE DISCHARGE; GLOW-DISCHARGE AB The conditions under which spontaneously oscillating d.c. discharges may be formed are described, and two different experimental configurations with distinct operating properties are presented. Using these discharges, optogalvanic and pseudosonic wave frequency spectroscopies are performed in neon. Signal magnitude in both techniques is discussed in terms of the change in the discharge power spectra caused by laser excitation of an atomic neon transition. Both methods are used to observe Il in a binary mixture of H-2 and Ne. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Stevens Inst Technol, Dept Phys & Engn Phys, Hoboken, NJ 07030 USA. RP Wilkerson, CW (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 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 AUG 1 PY 2000 VL 55 IS 8 BP 1249 EP 1256 DI 10.1016/S0584-8547(00)00213-5 PG 8 WC Spectroscopy SC Spectroscopy GA 343VK UT WOS:000088723000003 ER PT J AU Praphairaksit, N Wiederin, DR Houk, RS AF Praphairaksit, N Wiederin, DR Houk, RS TI An externally air-cooled low-flow torch for inductively coupled plasma mass spectrometry SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE inductively coupled plasma mass spectrometry inductively coupled plasma; torch design; low-flow torch ID ATOMIC EMISSION-SPECTROMETRY; POLYATOMIC ION INTERFERENCES; ENLARGED SAMPLING ORIFICE; ICP-MS; POWER; LENS; PERFORMANCE; SIGNAL; MERIT AB A low-flow torch specifically designed for inductively coupled plasma mass spectrometry (ICP-MS) was developed and evaluated. The outside of the torch is cooled externally by pressurized air flowing at similar to 70 1 min(-1) through a fourth tube sealed onto the usual 'outer' tube of a standard minitorch. This external air flow merely cools the outer tube of the torch and does not enter the plasma. Although plasmas can be sustained at operating power as low as 400 W with a 2 1 min(-1) outer Ar flow, somewhat higher power and Rows are advisable. A stable and analytically useful. Under optimum operating conditions, plasma can be obtained at 850 W with an outer. Ar how rate of only 4 1 min(-1) the externally air-cooled plasma produces comparable sensitivities, M2+/M+ signal ratios, matrix effects and other analytical figures of merit as those produced by a conventional torch while using much less argon. MO+/M+ signal ratios are slightly higher with the externally cooled torch. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. RP Houk, RS (reprint author), Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. NR 46 TC 16 Z9 16 U1 0 U2 2 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 AUG 1 PY 2000 VL 55 IS 8 BP 1279 EP 1293 DI 10.1016/S0584-8547(00)00216-0 PG 15 WC Spectroscopy SC Spectroscopy GA 343VK UT WOS:000088723000006 ER PT J AU Heske, C Eich, D Fink, R Umbach, E van Buuren, T Bostedt, C Kakar, S Terminello, LJ Grush, MM Callcott, TA Himpsel, FJ Ederer, DL Perera, RCC Riedl, W Karg, F AF Heske, C Eich, D Fink, R Umbach, E van Buuren, T Bostedt, C Kakar, S Terminello, LJ Grush, MM Callcott, TA Himpsel, FJ Ederer, DL Perera, RCC Riedl, W Karg, F TI Semi-quantitative and non-destructive analysis of impurities at a buried interface: Na and the CdS/Cu(In,Ga)Se-2 heterojunction SO SURFACE AND INTERFACE ANALYSIS LA English DT Article; Proceedings Paper CT 8th European Conference on Applications of Surface and Interface Analysis CY OCT 04-08, 1999 CL SEVILLE, SPAIN DE x-ray emission spectroscopy; photoelectron spectroscopy; buried interface; thin-film solar cell; Na impurities ID FILM SOLAR-CELLS; THIN-FILMS; CU(IN,GA)SE-2; SURFACES; CUINSE2; ENERGY AB We demonstrate how a combination of photoelectron spectroscopy and x-ray emission spectroscopy can be utilized to derive semi-quantitative information about the localization of impurities at buried interfaces. In the case of the CdS/Cu(In,Ga)Se-2 (CIGS) thin-film solar cell heterojunction, segregated Na, which stems from the soda-lime glass substrate or is deliberately added, plays an important role. We find that almost all Na atoms are located at the external CIGS surface or at the CdS/CIGS interface, and that the Na concentration in the bulk of the CIGS film is <1 ppm, Moreover, we show that the Na surface coverage at internal CIGS surfaces is significantly lower than at the external CIGS surface or CdS/CIGS interface, which demonstrates that the internal surfaces may not be regarded merely as a special case of the external surface. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Univ Wurzburg, D-97074 Wurzburg, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Wisconsin, Dept Phys, Madison, WI USA. Tulane Univ, New Orleans, LA 70118 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Siemens AG ZT, D-80807 Munich, Germany. Siemens Solar GmbH, D-80807 Munich, Germany. RP Heske, C (reprint author), Univ Wurzburg, D-97074 Wurzburg, Germany. RI Fink, Rainer/C-5333-2008; Fink, Rainer/F-8365-2010 OI Fink, Rainer/0000-0002-6896-4266; Fink, Rainer/0000-0002-6896-4266 NR 19 TC 8 Z9 8 U1 2 U2 13 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD AUG PY 2000 VL 30 IS 1 BP 459 EP 463 PG 5 WC Chemistry, Physical SC Chemistry GA 352VK UT WOS:000089238400099 ER PT J AU Rouxel, D Cai, TH Jenks, CJ Lograsso, TA Ross, A Thiel, PA AF Rouxel, D Cai, TH Jenks, CJ Lograsso, TA Ross, A Thiel, PA TI Structural aspects of the threefold surface of icosahedral Al-Pd-Mn SO SURFACE SCIENCE LA English DT Letter DE aluminum; alloys; metallic surfaces; scanning tunneling microscopy ID SCANNING-TUNNELING-MICROSCOPY; QUASI-CRYSTALS; AL68PD23MN9; LEED; STM AB We report the first STM study of a threefold surface of an icosahedral quasicrystal. We find that a rough, cluster-dominated structure evolves into a terrace-step morphology, with increasing temperature. The terraces display a fine structure whose long-range order is consistent with threefold symmetry. The fine structure includes small, deep holes. The steps can be very straight, serving to bound equilateral triangles (or portions thereof). These straight steps can cut directly across meandering step edges, superimposing a triangular 'shadow' upon the other terrace-step landscape. The data suggest that the triangles grow outward from a special type of central point. The triangles may represent the initial stages of facetting. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Ecole Mines, F-54042 Nancy, France. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Thiel, PA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 16 TC 12 Z9 12 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 AUG 1 PY 2000 VL 461 IS 1-3 BP L521 EP L527 DI 10.1016/S0039-6028(00)00513-6 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 343EZ UT WOS:000088689900002 ER PT J AU Yang, SH Mun, BS Kay, AW Kim, SK Kortright, JB Underwood, JH Hussain, Z Fadley, CS AF Yang, SH Mun, BS Kay, AW Kim, SK Kortright, JB Underwood, JH Hussain, Z Fadley, CS TI Depth-resolved photoemission spectroscopy from surface and buried layers with soft X-ray standing waves SO SURFACE SCIENCE LA English DT Letter DE boron; carbides; diffusion and migration; soft X-ray photoelectron spectroscopy; tungsten; X-ray standing waves ID HIGH-RESOLUTION; MULTILAYER; DIFFRACTION; REFLECTION; SCATTERING; REGION; FILMS AB A new type of depth-resolved soft X-ray photoemission spectroscopy (SXPS) is carried out in which depth sensitivity is provided by means of a periodic multilayer {[B4C(22.5 Angstrom)-W(17.1 Angstrom)](40)} that possesses sizeable standing wave effects of +/- similar to 50-60% for soft X-rays at hv approximate to 750 eV. The photoelectron intensities of each element in the sample, including impurity overlayers, are sharply altered when the incidence angle is tuned over the Bragg condition, in excellent agreement with theoretical simulations. The angular dependence of photoelectron intensity also shows unique chemical-state-resolved behavior depending on the location of a given species in the multilayer structure. Depth-resolved SXPS with soft X-ray standing wave excitation should thus be a very useful tool for studying surface and interface chemical, electronic, and magnetic properties. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95016 USA. RP Yang, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Mun, Bongjin /G-1701-2013; Kim, Sang-Koog/J-4638-2014 NR 24 TC 21 Z9 21 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 1 PY 2000 VL 461 IS 1-3 BP L557 EP L564 DI 10.1016/S0039-6028(00)00617-8 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 343EZ UT WOS:000088689900007 ER PT J AU Rasch, PJ Feichter, J Law, K Mahowald, N Penner, J Benkovitz, C Genthon, C Giannakopoulos, C Kasibhatla, P Koch, D Levy, H Maki, T Prather, M Roberts, DL Roelofs, GJ Stevenson, D Stockwell, Z Taguchi, S Kritz, M Chipperfield, M Baldocchi, D McMurry, P Barrie, L Balkansi, Y Chatfield, R Kjellstrom, E Lawrence, M Lee, HN Lelieveld, J Noone, KJ Seinfeld, J Stenchikov, G Schwartz, S Walcek, C Williamson, D AF Rasch, PJ Feichter, J Law, K Mahowald, N Penner, J Benkovitz, C Genthon, C Giannakopoulos, C Kasibhatla, P Koch, D Levy, H Maki, T Prather, M Roberts, DL Roelofs, GJ Stevenson, D Stockwell, Z Taguchi, S Kritz, M Chipperfield, M Baldocchi, D McMurry, P Barrie, L Balkansi, Y Chatfield, R Kjellstrom, E Lawrence, M Lee, HN Lelieveld, J Noone, KJ Seinfeld, J Stenchikov, G Schwartz, S Walcek, C Williamson, D TI A comparison of scavenging and deposition processes in global models: results from the WCRP Cambridge Workshop of 1995 SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODELS; TROPOSPHERIC AEROSOLS; VERTICAL TRANSPORT; RESIDENCE TIMES; CLIMATE MODEL; TRACER MODEL; PB-210; RN-222; SIMULATION; ATMOSPHERE AB We report on results from a World Climate Research Program workshop on representations of scavenging and deposition processes in global transport models of the atmosphere. 15 models were evaluated by comparing simulations of radon, lead, sulfur dioxide, and sulfate against each other, and against observations of these constituents. This paper provides a survey on the simulation differences between models. It identifies circumstances where models are consistent with observations or with each other, and where they differ from observations or with each other. The comparison shows that most models are able to simulate seasonal species concentrations near the surface over continental sites to within a factor of 2 over many regions of the globe. Models tend to agree more closely over source (continental) regions than for remote (polar and oceanic) regions. Model simulations differ most strongly in the upper troposphere for species undergoing wet scavenging processes. There are not a sufficient number of observations to characterize the climatology (long-term average) of species undergoing wet scavenging in the upper troposphere. This highlights the need for either a different strategy for model evaluation (e.g., comparisons on an event by event basis) or many more observations of a few carefully chosen constituents. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. Univ Cambridge, Dept Chem, Ctr Atmospher Sci, Cambridge CB2 1EW, England. Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Brookhaven Natl Lab, Environm Chem Div, Upton, NY 11973 USA. CNRS, LGGE, F-38402 St Martin Dheres, France. Duke Univ, Levine Sci Res Ctr, Sch Environm, Durham, NC 27708 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. GFDL, Princeton, NJ 08542 USA. JMA, Chiyoda Ku, Tokyo 100, Japan. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92717 USA. Meteorol Off, Bracknell RG12 2SY, Berks, England. Univ Utrecht, IMAU, NL-3584 CC Utrecht, Netherlands. NIRE, Tsukuba, Ibaraki 305, Japan. SUNY Albany, MSRC, New York, NY USA. NOAA, ATDD, Oak Ridge, TN 37831 USA. Univ Minnesota, Minneapolis, MN 55455 USA. AES Downsview, Downsview, ON M3H 5T4, Canada. CEA, DSM, LMCE, F-91191 Gif Sur Yvette, France. MISU, S-10691 Stockholm, Sweden. MPI Chem, D-55122 Mainz, Germany. US DOE, Environm Measurements Lab, New York, NY 10014 USA. Univ Maryland, College Pk, MD 20742 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12205 USA. RP Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM pjr@ucar.edu RI McMurry, Peter/A-8245-2008; Baldocchi, Dennis/A-1625-2009; Kasibhatla, Prasad/A-2574-2010; Stevenson, David/C-8089-2012; Schwartz, Stephen/C-2729-2008; Mahowald, Natalie/D-8388-2013; Chipperfield, Martyn/H-6359-2013; Penner, Joyce/J-1719-2012; Georgiy, Stenchikov/J-8569-2013; Giannakopoulos, Christos/H-6827-2014; Lelieveld, Johannes/A-1986-2013; OI McMurry, Peter/0000-0003-1609-5131; Baldocchi, Dennis/0000-0003-3496-4919; Stevenson, David/0000-0002-4745-5673; Schwartz, Stephen/0000-0001-6288-310X; Mahowald, Natalie/0000-0002-2873-997X; Chipperfield, Martyn/0000-0002-6803-4149; Kasibhatla, Prasad/0000-0003-3562-3737; Balkanski, Yves/0000-0001-8241-2858; Kjellstrom, Erik/0000-0002-6495-1038 NR 47 TC 122 Z9 123 U1 0 U2 12 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 1600-0889 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD AUG PY 2000 VL 52 IS 4 BP 1025 EP 1056 DI 10.1034/j.1600-0889.2000.00980.x PG 32 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 361KA UT WOS:000089721200001 ER PT J AU Schwegler, E Challacombe, M AF Schwegler, E Challacombe, M TI Linear scaling computation of the Fock matrix. III. Formation of the exchange matrix with permutational symmetry SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE linear scaling; exact exchange; electron repulsion integrals; Gaussian basis functions; permutational symmetry ID ELECTRONIC-STRUCTURE CALCULATIONS; DENSITY-FUNCTIONAL-THEORY; 2-ELECTRON INTEGRALS; LARGE MOLECULES AB A direct comparison is made between two recently proposed methods for linear scaling computation of the Hartree-Fock exchange matrix to investigate the importance of exploiting two-electron integral permutational symmetry. Calculations on three-dimensional water clusters and graphitic sheets with different basis sets and levels of accuracy are presented to identify specific cases where permutational symmetry may or may not be useful. We conclude that a reduction in integrals via permutational symmetry does not necessarily translate into a reduction in computation times. For large insulating systems and weakly contracted basis sets the advantage of permutational symmetry is found to be negligible, while for noninsulating systems and highly contracted basis sets a fourfold speedup is approached. C1 Univ Calif Los Alamos Natl Lab, Theoret Chem Div, Los Alamos, NM 87545 USA. Univ Minnesota, Minnesota Supercomp Inst, Minneapolis, MN 55415 USA. RP Challacombe, M (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Chem Div, POB 1663, Los Alamos, NM 87545 USA. RI Schwegler, Eric/F-7294-2010; Schwegler, Eric/A-2436-2016 OI Schwegler, Eric/0000-0003-3635-7418 NR 35 TC 20 Z9 20 U1 0 U2 13 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD AUG PY 2000 VL 104 IS 5 BP 344 EP 349 DI 10.1007/s002140000127 PG 6 WC Chemistry, Physical SC Chemistry GA 346GW UT WOS:000088863500003 ER PT J AU Ely, JH Ohno, TR Furtak, TE Nelson, AJ AF Ely, JH Ohno, TR Furtak, TE Nelson, AJ TI Raman characterization of epitaxial Cu-In-Se thin films SO THIN SOLID FILMS LA English DT Article DE Raman spectroscopy; Cu-In-Se thin films; epitaxial ID LATTICE-VIBRATIONS; CUINSE2; SPECTRA; CUIN3SE5 AB We have fabricated epitaxial chalcopyrite alloys with varying compositions and thicknesses on GaAs (001) substrates using a simple physical vapor deposition method. Growth of the films was characterized with Raman spectroscopy as well as by other analytical techniques. We identified both CuInSe2 (001) and CuIn3Se5 (001). All of the spectra were dominated by the A(1)(Gamma(1)((1)) [W-1]) non-polar optical made at 172 cm(-1) for CuInSe2 and 152 cm(-1) for the CuIn3Se5 phase. In addition, Raman spectra for the thinner layers indicated that these films are under compressive stress due to the lattice mismatch between the films and the substrate. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Div Chem & Chem Engn, Livermore, CA 94550 USA. Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. RP Nelson, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Chem & Chem Engn, 7000 East Ave L-370, Livermore, CA 94550 USA. RI Ohno, Timothy/J-9384-2014 NR 22 TC 8 Z9 8 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 AUG 1 PY 2000 VL 371 IS 1-2 BP 36 EP 39 DI 10.1016/S0040-6090(00)01002-6 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 335ZB UT WOS:000088276200005 ER PT J AU Donovan, LA West, JB McLeod, KW AF Donovan, LA West, JB McLeod, KW TI Quercus species differ in water and nutrient characteristics in a resource-limited fall-line sandhill habitat SO TREE PHYSIOLOGY LA English DT Article DE nitrogen; oak; photosynthesis; soil-to-leaf hydraulic conductance; water potential ID CARBON-ISOTOPE DISCRIMINATION; USE EFFICIENCY; HYDRAULIC CONDUCTANCE; SOIL-MOISTURE; STOMATAL CONDUCTANCE; CENTRAL PENNSYLVANIA; LEAF MORPHOLOGY; OAK COMMUNITY; GAS-EXCHANGE; CARYA FOREST AB We compared co-occurring mature Quercus laevis Walt. (turkey oak), Q. margaretta Ashe (sand post oak) and Q. incana Bartr. (bluejack oak) trees growing in resource-limited sandhill habitats of the southeastern United States for water and nutrient characteristics. The Quercus spp, differed in their distribution along soil water and nutrient gradients, and in their access to and use of water, even though the study year was wetter than average with no mid-season drought. Quercus laevis had the greatest access to soil water (least negative predawn water potential, Psi(pd)) and the most conservative water-use strategy based on its relatively low stomatal conductance (g(s)), high instantaneous water-use efficiency (WUE), least negative midday water potential (Psi(md)) and high leaf specific hydraulic conductance (K-L) Quercus margaretta had the least conservative water-use characteristics, exhibiting relatively high g(s), low instantaneous WUE, most negative Psi(md), and low K-L Quercus margaretta also had a low photosynthetic nitrogen-use efficiency (PNUE), but a high leaf phosphorus concentration, Quercus incana had the poorest access to soil water, but intermediate water-use characteristics and leaf nutrient characteristics more similar to those of Q. laevis. There were no species differences for photosynthesis (A), leaf nitrogen on an area basis, or seasonally integrated WUE (delta(13)C). Both A and g(s) were positively correlated for each species, but A and g,(s) were generally not correlated with Psi(pd), Psi(md) or Delta Psi(pd-md). Although we found differences in resource use and resource status among these sandhill Qeurcus spp., the results are consistent with the interpretation that they are generally drought avoiders. Quercus laevis may have an advantage on xeric ridges because of its greater ability to access soil water and use it more conservatively compared with the other Quercus spp. C1 Univ Georgia, Dept Bot, Athens, GA 30602 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Donovan, LA (reprint author), Univ Georgia, Dept Bot, Athens, GA 30602 USA. RI West, Jason/G-8833-2012; Donovan, Lisa/H-4754-2016; OI Donovan, Lisa/0000-0001-9814-0666; West, Jason/0000-0002-7811-8020 NR 60 TC 25 Z9 25 U1 1 U2 7 PU HERON PUBLISHING PI VICTORIA PA 202, 3994 SHELBOURNE ST, VICTORIA, BC V8N 3E2, CANADA SN 0829-318X J9 TREE PHYSIOL JI Tree Physiol. PD AUG PY 2000 VL 20 IS 14 BP 929 EP 936 PG 8 WC Forestry SC Forestry GA 340JD UT WOS:000088528600002 PM 11303567 ER PT J AU Blau, PJ Walukas, M AF Blau, PJ Walukas, M TI Sliding friction and wear of magnesium alloy AZ91D produced by two different methods SO TRIBOLOGY INTERNATIONAL LA English DT Article DE adhesive wear; dry friction; sliding friction; magnesium; magnesium alloys; reciprocating sliding wear AB Alloy AZ91D is a leading magnesium alloy used for structural applications. It contains aluminum and zinc as principal alloying elements. This alloy is normally die-cast, but recent developments in semi-solid injection molding (Thixomolding(R)), which offers certain processing advantages, produces a slightly different microstructure than die-casting, and it was of interest to determine whether the two processing routes would measurably affect the friction and wear of AZ91D. The present work involved ambient air, room temperature testing of die-cast (DC) and Thixomolded(R) (ThM) AZ91D, in both unidirectional and reciprocating sliding motion, using stainless steel type 440C as the counterface. After running-in, the average sliding friction coefficients in both types of test full into the range of 0.29-0.35, irrespective of processing method. The formation of a built-up edge raised the friction slightly in unidirectional tests compared with reciprocating tests. The average wear rate of the ThM alloys in reciprocating sliding was approximately 25% lower than that for DC alloys. However, the wear rates of the magnesium specimens in unidirectional sliding were comparable for DC and ThM materials. Owing to the transfer of magnesium, there was no measurable wear on the stainless steel 440C balls. The wear mechanism during sliding involves the formation of thin, narrow shards along the edges of wear grooves which break off to produce loose particles. Published by Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Thixomat Inc, Ann Arbor, MI 48109 USA. RP Blau, PJ (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 5 TC 65 Z9 72 U1 0 U2 7 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 AUG PY 2000 VL 33 IS 8 BP 573 EP 579 DI 10.1016/S0301-679X(00)00108-0 PG 7 WC Engineering, Mechanical SC Engineering GA 368PD UT WOS:000090125800007 ER PT J AU Finsterle, S AF Finsterle, S TI Using the continuum approach to model unsaturated flow in fractured rock SO WATER RESOURCES RESEARCH LA English DT Article ID HETEROGENEOUS POROUS-MEDIA; FIELD DATA; NETWORK; SEEPAGE; CALIBRATION; VALIDATION; TRANSPORT; ZONES AB The appropriateness of using the continuum approach for simulations of unsaturated flow through fractured rock is examined in a numerical study of water seepage into an underground opening. A continuum model is calibrated against data generated with a high-resolution model that created discrete flow and seepage behavior. Probabilistic predictions of injection data and seepage rates are then compared to the values from the discrete model. The study shows that reasonable results can be obtained with a calibrated continuum model even for fractured systems in which the underlying flow processes are discrete. Calibration is a crucial step in this approach because it yields effective, model-related, and process-specific parameters. The impact of discretization on the estimated parameters is discussed. Prediction uncertainty is evaluated by means of Monte Carlo simulations, including both the impact of parameter uncertainties and the effect of local heterogeneity. In this paper, the advantages and limitations of the continuum approach are discussed from a practical perspective, which includes a critical examination of project objectives, data needs, robustness of assumptions, and prediction uncertainty. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Finsterle, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. EM safinsterle@lbl.gov RI Finsterle, Stefan/A-8360-2009 OI Finsterle, Stefan/0000-0002-4446-9906 NR 40 TC 42 Z9 42 U1 0 U2 4 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 AUG PY 2000 VL 36 IS 8 BP 2055 EP 2066 DI 10.1029/2000WR900122 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 340UZ UT WOS:000088554500006 ER PT J AU Zhang, DX Andricevic, R Sun, AY Hu, XL He, GW AF Zhang, DX Andricevic, R Sun, AY Hu, XL He, GW TI Solute flux approach to transport through spatially nonstationary flow in porous media SO WATER RESOURCES RESEARCH LA English DT Article ID KINETICALLY SORBING SOLUTE; HETEROGENEOUS FORMATIONS; VELOCITY-FIELDS; STOCHASTIC-ANALYSIS; 3-DIMENSIONAL FLOW; DISPERSION; AQUIFERS; MACRODISPERSION; CONDUCTIVITY; GROUNDWATER AB A theoretical framework for solute flux through spatially nonstationary flows in porous media is presented. The flow nonstationarity may stem from medium nonstationarity (e.g., the presence of distinct geological layers, zones, or facies), finite domain boundaries, and/or fluid pumping and injecting. This work provides an approach for studying solute transport in multiscale media, where random heterogeneities exist at some small scale while deterministic geological structures and patterns can be prescribed at some larger scale. In such a flow field the solute flux depends on solute travel time and transverse displacement at a fixed control plane. The solute flux statistics (mean and variance) are derived using the Lagrangian framework and are expressed in terms of the probability density functions (PDFs) of the particle travel time and transverse displacement. These PDFs are given with the statistical moments derived based on nonstationary Eulerian velocity moments. The general approach is illustrated with some examples of conservative and reactive solute transport in stationary and nonstationary flow fields. It is found based on these examples that medium nonstationarities (or multiscale structures and heterogeneities) have a strong impact on predicting solute flux across a control plane and on the corresponding prediction uncertainty. In particular, the behavior of solute flux moments strongly depends on the configuration of nonstationary medium features and the source dimension and location. The developed nonstationary approach may result in non-Gaussian (multiple modal) yet realistic behaviors for solute flux moments in the presence of flow nonstationarities, while these non-Gaussian behaviors may not be reproduced with a traditional stationary approach. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Nevada, Desert Res Inst, Water Resources Ctr, Las Vegas, NV 89132 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; Sun, Alexander/A-9959-2011 OI Zhang, Dongxiao/0000-0001-6930-5994; NR 36 TC 36 Z9 38 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 AUG PY 2000 VL 36 IS 8 BP 2107 EP 2120 DI 10.1029/2000WR900085 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 340UZ UT WOS:000088554500010 ER PT J AU Hosking, FM Cadden, CH Yang, NYC Glass, SJ Stephens, JJ Vianco, PT Walker, CA AF Hosking, FM Cadden, CH Yang, NYC Glass, SJ Stephens, JJ Vianco, PT Walker, CA TI Microstructural and mechanical characterization of actively brazed alumina tensile specimens SO WELDING JOURNAL LA English DT Article DE alumina; brazing; gold-based alloys; active brazing; ceramic-to-ceramic; metal-to-ceramic ID BRAZING ALLOYS; CERAMICS; METAL; SYSTEMS AB Alumina (94 and 99.8% grade compositions) was brazed directly to itself with gold-based active brazing alloys (ABAs) containing nominally 1, 2 or 3 wt-% vanadium. The effects of brazing conditions on the joint properties were investigated. Wetting behavior, interfacial reactions, microstructure, hermeticity and tensile strength were determined. Wetting was generally fair to good for the ABA and base-material combinations. Microanalysis identified a discontinuous reaction product at the alumina-braze interface as an Al-V-O spinel-type phase. Tensile strength of the 94%, alumina specimens was generally not sensitive to the vanadium concentration and consistent within an 85-105 MPa range. The tensile data for the 99.8% alumina specimens, however, had significantly greater variability, with values ranging from 25 to 95 MPa. The highest value was obtained for the samples brazed with the filler metal containing 3 wt-% vanadium. Fractures occurred either along the braze-alumina interface for the 99.8% alumina specimens or through the alumina piece with the 94% alumina samples. C1 Sandia Corp, Albuquerque, NM USA. RP Hosking, FM (reprint author), Sandia Corp, Albuquerque, NM USA. NR 29 TC 6 Z9 6 U1 0 U2 4 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 USA SN 0043-2296 J9 WELD J JI Weld. J. PD AUG PY 2000 VL 79 IS 8 BP 222S EP 230S PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 340VA UT WOS:000088554600021 ER PT J AU Follstaedt, DM Reno, JL Jones, ED Lee, SR Norman, AG Moutinho, HR Mascarenhas, A Twesten, RD AF Follstaedt, DM Reno, JL Jones, ED Lee, SR Norman, AG Moutinho, HR Mascarenhas, A Twesten, RD TI Effect of surface steps on the microstructure of lateral composition modulation SO APPLIED PHYSICS LETTERS LA English DT Article ID SHORT-PERIOD SUPERLATTICES; MOLECULAR-BEAM EPITAXY; LAYER ORDERING PROCESS; QUANTUM-WELLS; GROWTH AB Growth of InAs/AlAs short-period superlattices on appropriately miscut (001) InP substrates is shown to alter the microstructure of composition modulation from a two-dimensional organization of short compositionally enriched wires to a single dominant modulation direction with wire lengths up to similar to 1 mu m. The effects of miscut are interpreted in terms of surface step orientation and character. The material is strongly modulated and exhibits intense optical emission. The one-dimensional modulations appear potentially useful for new devices that take advantage of the preferred direction formed in the growth plane. (C) 2000 American Institute of Physics. [S0003-6951(00)04831-2]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Illinois, Urbana, IL 61801 USA. RP Sandia Natl Labs, MS 1056, Albuquerque, NM 87185 USA. EM dmfolls@sandia.gov RI Norman, Andrew/F-1859-2010 OI Norman, Andrew/0000-0001-6368-521X NR 18 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 31 PY 2000 VL 77 IS 5 BP 669 EP 671 DI 10.1063/1.127080 PG 3 WC Physics, Applied SC Physics GA 341FL UT WOS:000088580300021 ER PT J AU Lee, YE Norton, DP Budai, JD Rack, PD Potter, MD AF Lee, YE Norton, DP Budai, JD Rack, PD Potter, MD TI Photo- and cathodoluminescence characteristics of blue-light-emitting epitaxial Sr2CeO4 thin-film phosphors SO APPLIED PHYSICS LETTERS LA English DT Article ID PULSED-LASER DEPOSITION AB Orthorhombic epitaxial Sr2CeO4 thin-film phosphors were grown on (100) SrTiO3 and yttria-stabilized-zirconia (YSZ) single crystal substrates with epitaxial relationships of (100) [010](Sr2CeO4)//(100)[010](SrTi3) and (100)[010](Sr2CeO4)//(100)[011](YSZ), respectively. As-deposited films exhibit a broadband photoluminescence (PL) emission, peaking at about 477-381 nm with a maximum cathodoluminescence (CL) intensity at about 465 nm. Enhanced Pi, intensity was observed for the films deposited on (100) YSZ and SrTiO3 substrates as compared to deposits on c-plane sapphire substrates, correlating with improved intragranular crystallinity and reducing defects via epitaxy. Postannealing in air significantly enhanced both of the PL and CL intensities. Luminous efficiency of 0.14 lm/W at 1 kV and 22 mu A/cm(2) was observed for a 2-mu m-thick film annealed at 1000 degrees C in air. (C) 2000 American Institute of Physics. [S0003-6951(00)02427-X]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Adv Vis Technol Inc, W Henrietta, NY 14586 USA. RP Lee, YE (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Budai, John/R-9276-2016; OI Budai, John/0000-0002-7444-1306; Rack, Philip/0000-0002-9964-3254 NR 8 TC 44 Z9 50 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 31 PY 2000 VL 77 IS 5 BP 678 EP 680 DI 10.1063/1.127083 PG 3 WC Physics, Applied SC Physics GA 341FL UT WOS:000088580300024 ER PT J AU Pangilinan, GI Russell, TP Baer, MR Namkung, J Chambers, P AF Pangilinan, GI Russell, TP Baer, MR Namkung, J Chambers, P TI Underwater shock measurements using a ruby pressure gauge SO APPLIED PHYSICS LETTERS LA English DT Article ID R-LINE SHIFTS AB The measurement of the temporal profile of the pressure in a shock wave propagating underwater and interacting with a nearby metal plate is presented. Pressures are deduced from the time-resolved fluorescence of a submillimeter ruby crystal mounted on an optical fiber tip. The measured pressures agree with finite-element code predictions, which model the production and propagation of the shock wave. These measurements are useful to evaluate shock-induced phenomena that an strongly dependent an the temporal profile of a shock wave, in small-scale testing, and in substantiating finite-element code predictions. (C) 2000 American Institute of Physics. [S0003-6951(00)03331-3]. C1 USN, Div Chem, Res Lab, Washington, DC 20375 USA. Sandia Natl Lab, Dept 9112, Albuquerque, NM 87185 USA. USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. Nova Res Inc, Alexandria, VA 22308 USA. RP Pangilinan, GI (reprint author), USN, Div Chem, Res Lab, Code 6112, Washington, DC 20375 USA. NR 12 TC 3 Z9 3 U1 3 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 31 PY 2000 VL 77 IS 5 BP 684 EP 686 DI 10.1063/1.127085 PG 3 WC Physics, Applied SC Physics GA 341FL UT WOS:000088580300026 ER PT J AU Honda, S Modine, FA Meldrum, A Budai, JD Haynes, TE Boatner, LA AF Honda, S Modine, FA Meldrum, A Budai, JD Haynes, TE Boatner, LA TI Magneto-optical effects from nanophase alpha-Fe and Fe3O4 precipitates formed in yttrium-stabilized ZrO2 by ion implantation and annealing SO APPLIED PHYSICS LETTERS LA English DT Article ID SAPPHIRE AB Magneto-optically active nanocomposite structures have been created by using ion implantation and thermal processing to form precipitated layers of ferromagnetic alpha-Fe or ferrimagnetic Fe3O4 that are embedded in the near-surface region of (100)-oriented yttrium stabilized ZrO2 (YSZ). When Fe-implanted YSZ is annealed at 1100 degrees C in Ar+4%H-2, the redox conditions are sufficiently reducing so that metallic Fe is the stable phase. At lower temperatures the annealing conditions become less reducing and Fe3O4 becomes the stable phase. Transmission electron microscopy and x-ray diffraction studies established that each alpha-Fe or Fe3O4 particle is a single crystal that is cl crystallographically aligned with respect to the YSZ host. Magneto-optical effects due to both the alpha-Fe and Fe3O4 nanophase precipitates were found and characterized using magnetic circular dichroism. These magneto-optical effects have potential applications in integrated-optical devices. (C) 2000 American Institute of Physics. [S0003-6951(00)02031-3]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Honda, S (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Haynes, Tony/P-8932-2015; Boatner, Lynn/I-6428-2013; Budai, John/R-9276-2016 OI Haynes, Tony/0000-0003-2871-4745; Boatner, Lynn/0000-0002-0235-7594; Budai, John/0000-0002-7444-1306 NR 8 TC 27 Z9 28 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 31 PY 2000 VL 77 IS 5 BP 711 EP 713 DI 10.1063/1.127094 PG 3 WC Physics, Applied SC Physics GA 341FL UT WOS:000088580300035 ER PT J AU Belenkiy, R Haefele, A Eisen, MB Wohlrab, H AF Belenkiy, R Haefele, A Eisen, MB Wohlrab, H TI The yeast mitochondrial transport proteins: new sequences and consensus residues, lack of direct relation between consensus residues and transmembrane helices, expression patterns of the transport protein genes, and protein-protein interactions with other proteins SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES LA English DT Article DE mitochondrion; transport; protein; carrier; expression; gene ID AMINO-ACID-SEQUENCE; BEEF-HEART MITOCHONDRIA; ADP ATP CARRIER; SACCHAROMYCES-CEREVISIAE; PHOSPHATE-TRANSPORT; TROPONIN-C; ARGININE-BIOSYNTHESIS; GENOMIC SEQUENCE; IDENTIFICATION; OVEREXPRESSION AB Mitochondrial transport proteins (MTP) typically are homodimeric with a 30-kDa subunit with six transmembrane helices. The subunit possesses a sequence motif highly similar to Pro X Asp/Glu X X Lys/Arg X Arg within each of its three similar 10-kDa segments. Four (YNL083W, YFR045W, YPR021C, YDR470C) of the 35 yeast (S. cerevisiae) MTP genes were resequenced since the masses of their proteins deviate significantly from the typical 30 kDa. We now find these four proteins to have 545, 285, 902, and 502 residues, respectively. Together with only four other MTPs, the sequences of YPR021C and YDR470C show substitutions of some of the five residues that are absolutely conserved among the 12 MTPs with identified transport function and 17 other MTPs. We do now find these five consensus residues also in the new sequences of YNL083W and YFR045W. Additional analyses of the 35 yeast MTPs show that the location of transmembrane helix sequences do not correlate with the general consensus residues of the MTP family; protein segments connecting the six transmembrane helices and facing the intermembrane space are not uniformly short (about 20 residues) or long (about 40 residues) when facing the matrix; most MTPs have at least one transmembrane helix for which the sum of the negative hydropathy values of all residues yields a very small negative value, suggesting a membrane location bordering polar faces of other transmembrane helices or a non-transmembrane location. The extra residues of the three large MTPs are hydrophilic and at the N-terminal. The 200-residue N-terminal segment of YNL083W has four putative Ca2+-binding sites. The 500-residue N-terminal segment of YPR021C shows sequence similarity to enzymes of nucleic acid metabolism. cDNA microarray data show that YNL083W is expressed solely during sporulation, while the expressions of YFR045W, YPR021C, and YDR470C are induced by various stress situations. These results also show that the 35 MTP genes are expressed under a rather diverse set of metabolic conditions that may help identify the function of the proteins. Interestingly, yeast two-hybrid screens, that will also be useful in identifying the function of MTPs, indicate that MIR1, AAC3, YOR100C, and YPR011C do interact with non-MTPs. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Harvard Univ, Sch Med, Boston Biomed Res Inst, Watertown, MA 02472 USA. Harvard Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Watertown, MA 02472 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cellular Biol, Berkeley, CA 94720 USA. RP Wohlrab, H (reprint author), Harvard Univ, Sch Med, Boston Biomed Res Inst, 64 Grove St, Watertown, MA 02472 USA. FU NIGMS NIH HHS [GM 57563] NR 42 TC 39 Z9 44 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2736 J9 BBA-BIOMEMBRANES JI Biochim. Biophys. Acta-Biomembr. PD JUL 31 PY 2000 VL 1467 IS 1 BP 207 EP 218 DI 10.1016/S0005-2736(00)00222-4 PG 12 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 344BR UT WOS:000088738200021 PM 10930523 ER PT J AU Eugenio, P AF Eugenio, P CA Brookhaven E852 Collaboration TI Meson spectroscopy in pi(-)p interactions at 18 GeV/c - recent results from Brookhaven E852 SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscoy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys AB Brookhaven Experiment E852 is an experiment in meson spectroscopy configured to detect final states interactions of pi(-)p collisions in a search for meson states incompatible with the constituent quark model. A description of the experimental apparatus and a general overview of the latest results is given. C1 Rensselaer Polytech Inst, Troy, NY 12181 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Massachusetts, Dartmouth, MA USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Indiana Univ, Bloomington, IN 47405 USA. Northwestern Univ, Evanston, IL 60208 USA. Inst High Energy Phys, Protvino, Russia. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. RP Eugenio, P (reprint author), Rensselaer Polytech Inst, Troy, NY 12181 USA. 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 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUL 31 PY 2000 VL 675 IS 1-2 BP 149C EP 154C PG 6 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600028 ER PT J AU Lou, XC Benninger, T Dunwoodie, WM AF Lou, XC Benninger, T Dunwoodie, WM TI Physics with the initial state radiation events at B-factory experiments SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscoy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys AB Initial state radiation (ISR) events produced in e(+)e(-) collisions at the gamma(4S) energy region can provide access to e(+)e(-) annihilations at lower C. M. energies. At B-factory experiments the data rate is substantial for physics at all energies below the gamma(4S). This paper describes the tagging of the ISR events, and identifies several physics topics that can be studied with the ISR data. C1 Univ Texas, Dallas, TX 75230 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Lou, XC (reprint author), Univ Texas, Dallas, TX 75230 USA. NR 10 TC 1 Z9 1 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 JUL 31 PY 2000 VL 675 IS 1-2 BP 253C EP 256C PG 4 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600050 ER PT J AU Chen, JP AF Chen, JP TI Nucleon structure study at Jefferson Lab SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscoy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys ID PROTON AB With high luminosity 6 GeV electron beam, Jefferson Lab (CEBAF)'s study of the nucleon structure is focussed on the regime of strong interaction QCD. Highlights are shown on the study of the nucleon form factors, the spin structure, and the nucleon resonances. Selected new results are presented. Future upgrade to 12 GeV is briefly discussed. C1 Newport News, Jefferson Lab, Newport News, VA 23606 USA. RP Chen, JP (reprint author), Newport News, Jefferson Lab, Newport News, VA 23606 USA. NR 17 TC 1 Z9 1 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 JUL 31 PY 2000 VL 675 IS 1-2 BP 273C EP 278C DI 10.1016/S0375-9474(00)00265-7 PG 6 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600053 ER PT J AU Liu, TH AF Liu, TH TI Status of the BA(B)over-barAR experiment SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscoy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys AB This is a status report from the BA (B) over bar AR experiment at the Stanford Linear Accelerator Center, It has been designed to measure time-dependent asymmetries in the decays of neutral B masons (CP violation), whose interpretation in the Standard Model is directly related to the parameters of the Cabibbo-Kobayashi-Maskawa mixing matrix. C1 Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. RP Liu, TH (reprint author), Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUL 31 PY 2000 VL 675 IS 1-2 BP 297C EP 302C DI 10.1016/S0375-9474(00)00269-4 PG 6 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600057 ER PT J AU Miao, T AF Miao, T TI CP violation and mixing of B mesons at CDF SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscoy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys ID OSCILLATION AB We report recent studies of CP-violation and mixing in neutral B mesons from the CDF experiment at the Fermilab Tevatron Collider. Results of a direct measurement of the CP-violation parameter sin 2 beta using B-0 --> J/psi K-S(0) with multi flavor tagging algorithms, a search for B(s)0 - B(s)0 mixing using semileptonic decays, and the updated precision measurements of the B-0 - B-0 mixing parameter will be presented. The prospects for B physics with the upgraded CDF detector in the next Tevatron Collider run will also be discussed. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Miao, T (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 9 TC 0 Z9 0 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 JUL 31 PY 2000 VL 675 IS 1-2 BP 398C EP 403C DI 10.1016/S0375-9474(00)00296-7 PG 6 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600079 ER PT J AU Lipkin, HJ AF Lipkin, HJ TI Theoretical summary of the conference SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscopy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys ID MAGNETIC-MOMENTS; H-DIBARYON; PENTAQUARK; MASSES; BARYONS; SEARCH; DECAY; QCD AB The Constituent Quark Model has provided a remarkable description of the experimentally observed hadron spectrum but still has no firm theoretical basis. Attempts to provide a QCD justification discussed at Hadron99 include QCD Sum Rules, instantons, relativistic potential models and the lattice. Phenomenological analyses to clarify outstanding problems like the nature of the scalar and pseudoscalar mesons and the low branching ratio for psi' --> rho - pi were presented. New experimental puzzles include the observation of (p) over bar p --> phi pi. C1 Weizmann Inst Sci, Inst Particle Phys, IL-76100 Rehovot, Israel. Israel Acad Sci & Humanities, Jerusalem, Israel. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Weizmann Inst Sci, Inst Particle Phys, IL-76100 Rehovot, Israel. NR 38 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JUL 31 PY 2000 VL 675 IS 1-2 BP 443C EP 452C PG 10 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600085 ER PT J AU Chung, SU AF Chung, SU TI Selected topics from Hadron 99 - experimental summary SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 8th International Conference on Hadron Spectroscopy (hadron '99) CY AUG 24-28, 1999 CL BEIJING, PEOPLES R CHINA SP Inst High Energy Phys ID FLUX-TUBE MODEL; HYBRID MESONS; EXOTIC MESONS; 18 GEV/C; QCD; LATTICE; SYSTEM; STATE; REST; WAVE AB I gave a summary talk on the experimental part of Hadron 99. However, this writeup is not a summary in its normal sense tut rather a collection of a few topics not fully covered at the Conference. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, POB 5000, Upton, NY 11973 USA. NR 34 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JUL 31 PY 2000 VL 675 IS 1-2 BP 453C EP 465C PG 13 WC Physics, Nuclear SC Physics GA 338NR UT WOS:000088426600086 ER PT J AU Carena, M Haber, HE Heinemeyer, S Hollik, W Wagner, CEM Weiglein, G AF Carena, M Haber, HE Heinemeyer, S Hollik, W Wagner, CEM Weiglein, G TI Reconciling the two-loop diagrammatic and effective field theory computations of the mass of the lightest CP-even Higgs boson in the MSM SO NUCLEAR PHYSICS B LA English DT Article ID SUPERSYMMETRIC STANDARD MODEL; RADIATIVE-CORRECTIONS; DIMENSIONAL REDUCTION; 2-LOOP LEVEL; MSSM; RENORMALIZATION; REGULARIZATION; SECTOR; COUPLINGS; SEARCHES AB The mass of the lightest CP-even Higgs boson of the minimal supersymmetric extension of the standard model (MSSM) has previously been computed including O(alpha alpha(s)) two-loop contributions by an on-shell diagrammatic method, while approximate analytic results have also been obtained via renormalization-group-improved effective potential and effective field theory techniques. Initial comparisons of the corresponding two-loop results revealed an apparent discrepancy between terms that depend logarithmically on the supersymmetry-breaking scale, and different dependences of the nonlogarithmic terms on the squark mixing parameter, XI, In this paper, we determine the origin of these differences as a consequence of different renormalization schemes in which both calculations are performed. By reexpressing the on-shell result in terms of MS parameters, the logarithmic two-loop contributions obtained by the different approaches are shown to coincide. The remaining difference, arising from genuine nonlogarithmic two-loop contributions, is identified, and its effect on the maximal value of the lightest CP-even Higgs boson mass is discussed. Finally, we show that in a simple analytic approximation to the Higgs mass, the leading two-loop radiative corrections can be absorbed to a large extent into an effective one-loop expression by evaluating the running top quark mass at appropriately chosen energy scales. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CERN, Div TH, CH-1211 Geneva 23, Switzerland. FERMILAB, Batavia, IL 60510 USA. Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. DESY Theorie, D-22603 Hamburg, Germany. Univ Karlsruhe, Inst Theoret Phys, D-76128 Karlsruhe, Germany. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Weiglein, G (reprint author), CERN, Div TH, CH-1211 Geneva 23, Switzerland. NR 42 TC 255 Z9 255 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 31 PY 2000 VL 580 IS 1-2 BP 29 EP 57 DI 10.1016/S0550-3213(00)00212-1 PG 29 WC Physics, Particles & Fields SC Physics GA 335KU UT WOS:000088243300002 ER PT J AU Chalmers, G AF Chalmers, G TI S and U-duality constraints on IIBS-matrices SO NUCLEAR PHYSICS B LA English DT Article ID SUPERSTRING THEORY; STRING THEORY; ONE-LOOP; 4-GRAVITON AMPLITUDE; 11 DIMENSIONS; YANG-MILLS; SUPERGRAVITY; INSTANTONS AB S- and U-duality dictate that graviton scattering amplitudes in IIB superstring theory be automorphic functions on the appropriate fundamental domain which describe the inequivalent vacua of (compactified) theories. A constrained functional form of graviton scattering is proposed using Eisenstein series and their generalizations compatible with: (a) two-loop supergravity, (b) genus one superstring theory, (c) the perturbative coupling dependence of the superstring, and (d) with the unitarity structure of the massless modes. The form has a perturbative truncation in the genus expansion at a given order in the derivative expansion. Comparisons between graviton scattering S-matrices and effective actions for the first quantized superstring are made at the quantum level. Possible extended finiteness properties of maximally extended quantum supergravity theories in different dimensions is implied by the perturbative truncation of the functional form of graviton scattering in IIB superstring theory. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Chalmers, G (reprint author), Argonne Natl Lab, Div High Energy Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 39 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 31 PY 2000 VL 580 IS 1-2 BP 193 EP 224 DI 10.1016/S0550-3213(00)00156-5 PG 32 WC Physics, Particles & Fields SC Physics GA 335KU UT WOS:000088243300009 ER PT J AU Friedland, A AF Friedland, A TI Mikheyev-Smirnov-Wolfenstein effects in vacuum oscillations SO PHYSICAL REVIEW LETTERS LA English DT Article ID SOLAR-NEUTRINO PROBLEM; 2-NEUTRINO TRANSITIONS; ANALYTIC DESCRIPTION; MATTER; FLUX; SUN AB We point out that for solar neutrino oscillations with the mass-squared difference of Delta m(2) similar to 10(-10) - 10(-9) eV(2), i.e., in the so-called vacuum oscillation range, the solar matter effects are non-negligible, particularly for the low energy pp neutrinos. One consequence of this is that the values of the mixing angle theta and pi/2 - theta are not equivalent, making it necessary to consider the entire physical range of the mixing angle 0 less than or equal to theta less than or equal to pi/2 when determining the allowed values of the neutrino oscillation parameters. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Theory Grp, Berkeley, CA 94720 USA. RP Friedland, A (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 23 TC 36 Z9 36 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 JUL 31 PY 2000 VL 85 IS 5 BP 936 EP 939 DI 10.1103/PhysRevLett.85.936 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000009 ER PT J AU Chung, P Ajitanand, NN Alexander, JM Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, JL Cole, B Crowe, K Das, A Draper, JE Gilkes, ML Gushue, S Heffner, M Hirsch, AS Hjort, EL Huo, L Justice, M Kaplan, M Keane, D Kintner, JC Klay, J Krofcheck, D Lacey, RA Lauret, J Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, DL Panitkin, SY Pinkenburg, C Porile, NT Rai, G Ritter, HG Romero, JL Scharenberg, R Schroeder, L Srivastava, B Stone, NTB Symons, TJM Wienold, T Witt, R Whitfield, J Wood, L Zhang, WN AF Chung, P Ajitanand, NN Alexander, JM Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, JL Cole, B Crowe, K Das, A Draper, JE Gilkes, ML Gushue, S Heffner, M Hirsch, AS Hjort, EL Huo, L Justice, M Kaplan, M Keane, D Kintner, JC Klay, J Krofcheck, D Lacey, RA Lauret, J Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, DL Panitkin, SY Pinkenburg, C Porile, NT Rai, G Ritter, HG Romero, JL Scharenberg, R Schroeder, L Srivastava, B Stone, NTB Symons, TJM Wienold, T Witt, R Whitfield, J Wood, L Zhang, WN CA E895 Collaboration TI Antiflow of K-s(0) mesons in 6A GeV Au+Au collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; OUT-OF-PLANE; NEUTRON-STARS; KAON CONDENSATION; COLLECTIVE MOTION; DENSE MATTER; FLOW; EMISSION AB We have measured the sideward flow of neutral strange (K-s(0)) mesons in 6A GeV Au + Au collisions. A prominent antiflow signal is observed for an impact parameter range (b less than or equal to 7 fm) which spans central and midcentral events. Since the K-s(0) scattering cross section is relatively small in nuclear matter, this observation suggests that the in-medium kaon vector potential plays an important role in high density nuclear matter. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Kent State Univ, Kent, OH 44242 USA. Univ Calif Davis, Davis, CA 95616 USA. Purdue Univ, W Lafayette, IN 47907 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Auckland, Auckland, New Zealand. Columbia Univ, New York, NY 10027 USA. St Marys Coll, Moraga, CA 94575 USA. Harbin Inst Technol, Harbin 150001, Peoples R China. RP Chung, P (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Witt, Richard/H-3560-2012 NR 31 TC 30 Z9 30 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 JUL 31 PY 2000 VL 85 IS 5 BP 940 EP 943 DI 10.1103/PhysRevLett.85.940 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000010 ER PT J AU Bohn, CL Ng, KY AF Bohn, CL Ng, KY TI Preserving high multibunch luminosity in linear colliders SO PHYSICAL REVIEW LETTERS LA English DT Article AB An analytic theory of cumulative multibunch beam breakup in linear colliders is developed. Included is a linear variation of transverse focusing across the bunch train as might br applied, e.g., by chirping the radio frequency power sources or by using radio frequency quadrupole magnets. The focusing variation saturates the exponential growth sf the beam breakup and establishes an algebraic decay of the transverse bunch displacement versus bunch number. A closed-form expression for the transverse bunch displacement is developed. It is used to quantify the total normalized emittance and thereby isolate the region of parameter space corresponding to high multibunch luminosity. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bohn, CL (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 31 PY 2000 VL 85 IS 5 BP 984 EP 987 DI 10.1103/PhysRevLett.85.984 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000021 ER PT J AU Milton, SV Gluskin, E Biedron, SG Dejus, RJ Den Hartog, PK Galayda, JN Kim, KJ Lewellen, JW Moog, ER Sajaev, V Sereno, NS Travish, G Vinokurov, NA Arnold, ND Benson, C Berg, W Biggs, JA Borland, M Carwardine, JA Chae, YC Decker, G Deriy, BN Erdmann, MJ Friedman, H Gold, C Grelick, AE Hahne, MW Harkay, KC Huang, Z Lessner, ES Lill, RM Lumpkin, AH Makarov, OA Markovich, GM Meyer, D Nassiri, A Noonan, JR Pasky, SJ Pile, G Smith, TL Soliday, R Tieman, BJ Trakhtenberg, EM Trento, GF Vasserman, IB Walters, DR Wang, XJ Wiemerslage, G Xu, S Yang, BX AF Milton, SV Gluskin, E Biedron, SG Dejus, RJ Den Hartog, PK Galayda, JN Kim, KJ Lewellen, JW Moog, ER Sajaev, V Sereno, NS Travish, G Vinokurov, NA Arnold, ND Benson, C Berg, W Biggs, JA Borland, M Carwardine, JA Chae, YC Decker, G Deriy, BN Erdmann, MJ Friedman, H Gold, C Grelick, AE Hahne, MW Harkay, KC Huang, Z Lessner, ES Lill, RM Lumpkin, AH Makarov, OA Markovich, GM Meyer, D Nassiri, A Noonan, JR Pasky, SJ Pile, G Smith, TL Soliday, R Tieman, BJ Trakhtenberg, EM Trento, GF Vasserman, IB Walters, DR Wang, XJ Wiemerslage, G Xu, S Yang, BX TI Observation of self-amplified spontaneous emission and exponential growth at 530 nm SO PHYSICAL REVIEW LETTERS LA English DT Article ID ADVANCED PHOTON SOURCE; FEL AB Experimental evidence for self-amplified spontaneous emission (SASE) Lit 530 nm is reported. The measurements were made at the low-energy undulator test line facility at the Advanced Photon Source, Argonne National Laboratory. The experimental setup and details of the experimental results are presented, as well as preliminary analysis. This experiment extends to shorter wavelengths the operational knowledge of a linac-based SASE free-electron laser and explicitly shows the predicted exponential growth in intensity of the optical pulse as a function of length along the undulator. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Milton, SV (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RI Travish, Gil/H-4937-2011 OI Travish, Gil/0000-0002-4787-0949 NR 20 TC 53 Z9 57 U1 1 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 JUL 31 PY 2000 VL 85 IS 5 BP 988 EP 991 DI 10.1103/PhysRevLett.85.988 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000022 ER PT J AU Foord, ME Glenzer, SH Thoe, RS Wong, KL Fournier, KB Wilson, BG Springer, PT AF Foord, ME Glenzer, SH Thoe, RS Wong, KL Fournier, KB Wilson, BG Springer, PT TI Ionization processes and charge-state distribution in a highly ionized high-Z laser-produced plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID INERTIAL CONFINEMENT FUSION; ABSORPTION-SPECTROSCOPY; PROGRAM; MODEL AB The charge-state distribution in a well-characterized highly ionized An plasma was accurately determined using time-resolved x-ray spectroscopy. Simultaneous measurements of the electron temperature and density allow the first direct comparisons with nonlocal thermodynamic equilibrium model predictions for the charge-state distribution of a highly ionized high-Z plasma in a nonradiative: environment. The importance of two-electron atomic processes is clearly demonstrated. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Foord, ME (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 29 TC 84 Z9 96 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 31 PY 2000 VL 85 IS 5 BP 992 EP 995 DI 10.1103/PhysRevLett.85.992 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000023 ER PT J AU Wong, KL Chu, MS Luce, TC Petty, CC Politzer, PA Prater, R Chen, L Harvey, RW Austin, ME Johnson, LC La Haye, RJ Snider, RT AF Wong, KL Chu, MS Luce, TC Petty, CC Politzer, PA Prater, R Chen, L Harvey, RW Austin, ME Johnson, LC La Haye, RJ Snider, RT TI Internal kink instability during off-axis electron cyclotron current drive in the DIII-D tokamak SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-BETA; PLASMAS; MODES; WAVES AB Experimental evidence is reported of an internal kink instability driven by a new mechanism: barely trapped suprathermal electrons produced by off-axis electron cyclotron heating on the DIII-D tokamak. It occurs in plasmas with an evolving safety factor profile q(r) when q(min) approaches 1. This instability is most active when ECCD is applied on the high field side of the flux surface. It has a bursting behavior with poloidal/toroidal mode number = m/n = 1/1. In positive magnetic shear plasmas, this mode becomes the fishbone instability. This observation can be qualitatively explained by the drift reversal of the barely trapped suprathermal electrons. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Gen Atom Co, San Diego, CA 92186 USA. Univ Calif Irvine, Dept Phys, Irvine, CA 92717 USA. CompX, Del Mar, CA 92014 USA. Univ Texas, Austin, TX 78712 USA. RP Wong, KL (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI chen, liu/I-2297-2013 NR 20 TC 74 Z9 77 U1 2 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 31 PY 2000 VL 85 IS 5 BP 996 EP 999 DI 10.1103/PhysRevLett.85.996 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000024 ER PT J AU TenCate, JA Smith, E Guyer, RA AF TenCate, JA Smith, E Guyer, RA TI Universal slow dynamics in granular solids SO PHYSICAL REVIEW LETTERS LA English DT Article ID PROPAGATION; MEDIA; ROCKS AB Experimental properties of a new form of creep dynamics are reported, as manifest in a variety of sandstones, limestone, and concrete. The creep is a recovery behavior. following the sharp drop in elastic modulus induced either by nonlinear acoustic straining or rapid temperature change. The extent of modulus recovery is universally proportional to the logarithm of the time after source discontinuation in all samples studied, over a scaling regime covering at least 10(3) s. Comparison of acoustically and thermally induced creep suggests a single origin based on internal strain, which breaks the symmetry of the inducing source. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP TenCate, JA (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. NR 20 TC 106 Z9 109 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 31 PY 2000 VL 85 IS 5 BP 1020 EP 1023 DI 10.1103/PhysRevLett.85.1020 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000030 ER PT J AU Chang, CM Wei, CM Chen, SP AF Chang, CM Wei, CM Chen, SP TI Self-diffusion of small clusters on fcc metal (111) surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-DYNAMICS; AL; ADATOMS; NI AB We use ab initio density-functional theory supplemented with the embedded-atom method to study the self-diffusion of small clusters on the (111) surface of eight fee metals. A zigzag motion is found to be important in the dimer and tetramer diffusions. The dimer diffuses by a zigzag and concerted motion. The trimer diffuses by a concerted three-atom motion. The tetramer diffuses through a zigzag motion where only two atoms move simultaneously in each step. Thus, instead of increasing, the migration energy is lowered (or stays constant) for the tetramer as compared to that for the trimer. This novel break of the upwards trend in migration energy is predicted to be a general phenomenon. C1 Natl Ctr High Performance Comp, Hsinchu 30043, Taiwan. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Natl Ctr High Performance Comp, Hsinchu 30043, Taiwan. EM c00jim00@nchc.gov.tw RI Wei, Ching-Ming/F-7931-2012 NR 19 TC 52 Z9 53 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 31 PY 2000 VL 85 IS 5 BP 1044 EP 1047 DI 10.1103/PhysRevLett.85.1044 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000036 ER PT J AU Salluzzo, M Palomba, F Pica, G Andreone, A Maggio-Aprile, I Fischer, O Cantoni, C Norton, DP AF Salluzzo, M Palomba, F Pica, G Andreone, A Maggio-Aprile, I Fischer, O Cantoni, C Norton, DP TI Role of Nd/Ba disorder on the penetration depth of Nd1+xBa2-xCu3O7-delta thin films SO PHYSICAL REVIEW LETTERS LA English DT Article ID MICROWAVE SURFACE IMPEDANCE; TEMPERATURE-DEPENDENCE; SINGLE-CRYSTALS; SUPERCONDUCTORS; YBA2CU3O7-DELTA; YBA2CU3O6.95; STABILITY AB We report on a study on the effect of Nd/Ba disorder on the ab-plane penetration depth of epitaxial Nd1+xBa2-xCu3O7-delta thin films. While in stoichiometric samples lambda(T) at low temperature is linear, Nd-rich films exhibit a quadratic law. For low Nd excess (x < 0.04), a satisfying fit is obtained using the "dirty" d-wave model assuming that Nd ions at Ba sites act as strong scattering centers. At high x (x > 0.15) the data are explained if Nd/Ba disorder becomes less effective as a source of scattering. The effect of localization has been discussed to account for the experimental results. C1 INFM, I-80125 Naples, Italy. Univ Naples Federico II, Dipartimento Sci Fisiche, I-80125 Naples, Italy. Univ Geneva, Dept Phys Mat Condensee, CH-1211 Geneva, Switzerland. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Salluzzo, M (reprint author), INFM, I-80125 Naples, Italy. RI salluzzo, marco/C-5919-2009; Cantoni, Claudia/G-3031-2013 OI salluzzo, marco/0000-0001-8372-6963; Cantoni, Claudia/0000-0002-9731-2021 NR 24 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 31 PY 2000 VL 85 IS 5 BP 1116 EP 1119 DI 10.1103/PhysRevLett.85.1116 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000054 ER PT J AU Fisher, IR Bud'ko, SL Song, C Canfield, PC Ozawa, TC Kauzlarich, SM AF Fisher, IR Bud'ko, SL Song, C Canfield, PC Ozawa, TC Kauzlarich, SM TI Yb14ZnSb11: Charge balance in Zintl compounds as a route to intermediate Yb valence SO PHYSICAL REVIEW LETTERS LA English DT Article ID YB14MNSB11; EU14MNSB11 AB The results of thermodynamic, transport, and x-ray diffraction measurements of single crystals of the new compound Yb14ZnSb11 are presented. These data indicate an intermediate Yb valence scenario, with a spin fluctuation temperature of approximately 85 K. The compound is weakly metallic and is isostructural with the charge-balanced Zintl compound Yb14AlSb11. The intermediate Yb valence can be qualitatively accounted for by considering the charge counting arguments of the nonmetallic parent, and charge balance in Zintl-related materials appears to be a viable route to designing other compounds with intermediate valence constituents. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RP Fisher, IR (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Ozawa, Tadashi C./B-2535-2012; Canfield, Paul/H-2698-2014; Kauzlarich, Susan/H-1439-2011 OI Ozawa, Tadashi C./0000-0003-0118-115X; NR 17 TC 47 Z9 48 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 JUL 31 PY 2000 VL 85 IS 5 BP 1120 EP 1123 DI 10.1103/PhysRevLett.85.1120 PG 4 WC Physics, Multidisciplinary SC Physics GA 339BD UT WOS:000088457000055 ER PT J AU Lin, YH Wu, H Wai, CM Smart, NG AF Lin, YH Wu, H Wai, CM Smart, NG TI Separation of divalent transition metal beta-diketonates and their adducts by supercritical fluid chromatography SO TALANTA LA English DT Article DE supercritical fluid chromatography; beta-diketonate; transitional metal; supercritical fluid extraction ID LANTHANIDE; EXTRACTION AB A method for separation and detection of divalent transition metal beta-diketonates by adduct formation/supercritical fluid chromatography (SFC) with an open-tubular capillary column and a FID detector is described. The crystal structures of copper (Cu)-hexafluoro-acetylacetone (HFA) and Cu bis(2,2,6,6-tetramethyl-3,5-heptanedionato) (THD) complexes have been determined by X-ray crystallography. The SFC behavior of Cu beta-diketonates shows a strong correlation with the structure of the complexes. The hydrated cu beta-diketonate complexes usually exhibit strong intermolecular interactions or decomposition in SFC. Formation of adducts with a neutral donor, such as tributyl phosphine oxide (TBPO), can greatly improve the SPC behavior and detection sensitivity of Cu(IT) and Mn(II) beta-diketonates. The stoichiometry and thermal stability of the adducts Cu(II) and Mn(II) beta-diketonates with TBPO in supercritical CO2 have also been investigated. The implications of utilizing adduct formation for supercritical fluid extraction (SFE) of divalent transition metals and for on-line coupled SFE/SFC analysis of divalent transition metals are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Idaho, Dept Chem, Moscow, ID 83844 USA. BNFL, Co Res Lab, Preston PR4 OXJ, Lancs, England. RP Lin, YH (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-93, Richland, WA 99352 USA. RI Lin, Yuehe/D-9762-2011 OI Lin, Yuehe/0000-0003-3791-7587 NR 21 TC 13 Z9 14 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD JUL 31 PY 2000 VL 52 IS 4 BP 695 EP 701 DI 10.1016/S0039-9140(00)00418-5 PG 7 WC Chemistry, Analytical SC Chemistry GA 342LZ UT WOS:000088647200012 PM 18968028 ER PT J AU Wunderlich, B AF Wunderlich, B TI Temperature-modulated calorimetry in the 21st century SO THERMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT National AC Meeting on Semicrystalline Polymers CY AUG 22-26, 1999 CL NEW ORLEANS, LOUISIANA SP Natl AC DE temperature-modulated calorimetry; microcalorimetry; irreversible processes; nanophases; teaching of thermal analysis ID DIFFERENTIAL SCANNING CALORIMETRY; HEAT-CAPACITY; THERMODYNAMIC PROPERTIES; LINEAR MACROMOLECULES; THERMOSETTING SYSTEMS; VITRIFICATION; CRYSTALS; POLYMERS; DYNAMICS; LIQUID AB It is attempted to extrapolate to future developments in the field of thermal analysis, and, specifically, temperature modulated calorimetry (TMC), the latter being a subject that developed to prominence in the last 10 years. The predictions are made on the basis of the present techniques and on the need for the characterization of materials. Key issues are the advancement of the practice of TMC to quantitative calorimetry. Special topics mentioned are the analysis of nonequilibrium states and the characterization of nanophases. In instrumentation, the extensions of modulation to higher frequencies and the introduction of new techniques for smaller sample masses are discussed. One of the biggest needs is, however, to increase the teaching effort in this field, since many of the quantitative methods already available are not applied to the fullest because of a lack of qualified thermal analysts. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. RP Wunderlich, B (reprint author), Oak Ridge Natl Lab, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. NR 68 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD JUL 31 PY 2000 VL 355 IS 1-2 BP 43 EP 57 DI 10.1016/S0040-6031(00)00436-6 PG 15 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 326MP UT WOS:000087739600004 ER PT J AU Brown, ME Maciejewski, M Vyazovkin, S Nomen, R Sempere, J Burnham, A Opfermann, J Strey, R Anderson, HL Kemmler, A Keuleers, R Janssens, J Desseyn, HO Li, CR Tang, TB Roduit, B Malek, J Mitsuhashi, T AF Brown, ME Maciejewski, M Vyazovkin, S Nomen, R Sempere, J Burnham, A Opfermann, J Strey, R Anderson, HL Kemmler, A Keuleers, R Janssens, J Desseyn, HO Li, CR Tang, TB Roduit, B Malek, J Mitsuhashi, T TI Computational aspects of kinetic analysis Part A: The ICTAC kinetics project-data, methods and results SO THERMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT National AC Meeting on Semicrystalline Polymers CY AUG 22-26, 1999 CL NEW ORLEANS, LOUISIANA SP Natl AC DE kinetics; mechanisms; isothermal; non-isothermal; thermal analysis; solids; decomposition ID SOLID-STATE REACTIONS; THERMAL-ANALYSIS; THERMOANALYTICAL DATA AB Part A of this series of papers (Parts B to E follow) presents the data and methods used, as well as the results obtained by participants in the ICTAC Kinetics Project. The isothermal and non-isothermal data sets provided were based on a hypothetical simulated process as well as on some actual experimental results for the thermal decompositions of ammonium perchlorate and calcium carbonate. The participants applied a variety of computational methods. Isoconversional and multiheating rate methods were particularly successful in correctly describing the multi-step kinetics used in the simulated data. Reasonably consistent kinetic results were obtained for isothermal and non-isothermal data. There is, of course, no 'true' answer for the kinetic parameters of the real data, so the findings of the participants are compared. An attempt has been made to forecast the tendencies for the future development of solid state kinetics. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Rhodes Univ, Dept Chem, ZA-6140 Grahamstown, South Africa. Swiss Fed Inst Technol, ETH Zentrum, Tech Chem Lab, CH-8092 Zurich, Switzerland. Univ Utah, Dept Chem, Ctr Thermal Anal, Salt Lake City, UT 84112 USA. Univ Ramon Llull, Inst Quim Sarria, Dept Chem Engn, E-08017 Barcelona, Spain. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Netzsch Geratebau GMBH, D-95100 Selb Bavaria, Germany. Inst Phys Chem, D-17489 Greifswald, Germany. Univ Antwerp, RUCA, Dept Chem, B-2020 Antwerp, Belgium. Hong Kong Baptist Univ, Dept Phys, Kowloon, Hong Kong, Peoples R China. AKTS Corp, Charlotte, NC 28224 USA. Acad Sci Czech Republ, Joint Lab Solid State Chem, Pardubice 53210, Czech Republic. Univ Pardubice, Pardubice 53210, Czech Republic. Sci & Technol Agcy Japan, Natl Inst Res Inorgan Mat, Tsukuba, Ibaraki 305, Japan. RP Brown, ME (reprint author), Rhodes Univ, Dept Chem, ZA-6140 Grahamstown, South Africa. OI Nomen, Rosa/0000-0002-4529-9697 NR 37 TC 488 Z9 518 U1 5 U2 92 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD JUL 31 PY 2000 VL 355 IS 1-2 BP 125 EP 143 DI 10.1016/S0040-6031(00)00443-3 PG 19 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 326MP UT WOS:000087739600012 ER PT J AU Burnham, AK AF Burnham, AK TI Computational aspects of kinetic analysis. Part D: The ICTAC kinetics project - multi-thermal-history model-fitting methods and their relation to isoconversional methods SO THERMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT National AC Meeting on Semicrystalline Polymers CY AUG 22-26, 1999 CL NEW ORLEANS, LOUISIANA SP Natl AC DE kinetic analysis; nonlinear regression; isoconversional kinetics; ammonium perchlorate; calcium carbonate AB This paper is Part D of a discussion of the computational stage of solid-state reactions as applied to the data sets of the ICTAC Kinetic Analysis Project. This Part critically evaluates the results from the various participants and finds that kinetic analysis programs used by Burnham, Roduit, and Opfermann give very similar results. Isoconversional methods give kinetic parameters that agree qualitatively with those from subsequent nonlinear regression to appropriate models. Single-heating-rate methods work poorly and should not be used or published. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Burnham, AK (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 1 TC 170 Z9 184 U1 0 U2 35 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD JUL 31 PY 2000 VL 355 IS 1-2 BP 165 EP 170 DI 10.1016/S0040-6031(00)00446-9 PG 6 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 326MP UT WOS:000087739600015 ER PT J AU Santos, EC Pinkerton, AB Kinkead, SA Hurlburt, PK Jasper, SA Sellers, CW Huffman, JC Todd, LJ AF Santos, EC Pinkerton, AB Kinkead, SA Hurlburt, PK Jasper, SA Sellers, CW Huffman, JC Todd, LJ TI Syntheses of nido-9,11-X-2-7,8-C2B9H10- anions (X = Cl, Br or I) and the synthesis and structural characterization of N(C2H5)(4)[commo-3,3 '-Co(4,7-Br-2-3,1,2-CoC2B9H9)(2)] SO POLYHEDRON LA English DT Article DE halogenated carborane anions; cobalt bis(dicarbollide); boron; carborane; halogenation ID COBALT DICARBOLLIDE; DERIVATIVES AB Treatment of nido-7,8-C2B9H12- with N-halosuccinimide (halo = chloro, bromo or iodo) formed the corresponding nido-9,11-(halo)(2)-7,8 -C2B9H10- ion in good yield. The nido-9,11-Br-2-7,8-C2B9H10- ion was deprotonated with n-butyllithium and then reacted with cobalt(II) chloride to form the commo-3,3'-Co(4,7-Br-2-3,1,2-CoC2B9H9)(2)(-) ion. A single-crystal X-ray structure determination of this cobalt complex is reported. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Indiana Univ, Ctr Mol Struct, Bloomington, IN 47405 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Todd, LJ (reprint author), Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. OI Pinkerton, Anthony/0000-0003-4571-152X NR 13 TC 25 Z9 25 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-5387 J9 POLYHEDRON JI Polyhedron PD JUL 30 PY 2000 VL 19 IS 15 BP 1777 EP 1781 DI 10.1016/S0277-5387(00)00461-7 PG 5 WC Chemistry, Inorganic & Nuclear; Crystallography SC Chemistry; Crystallography GA 353KB UT WOS:000089272400002 ER PT J AU Anderson, BJ Gatley, SJ Rapp, DN Coburn-Litvak, PS Volkow, ND AF Anderson, BJ Gatley, SJ Rapp, DN Coburn-Litvak, PS Volkow, ND TI The ratio of striatal D1 to muscarinic receptors changes in aging rats housed in an enriched environment SO BRAIN RESEARCH LA English DT Article DE plasticity; dopamine; D-2 receptor; physical activity ID SIZED SPINY NEURONS; DOPAMINE-RECEPTORS; D2 DOPAMINE; CORPUS STRIATUM; BINDING; RELEASE; EXPRESSION; DENSITY; BRAIN; D-2 AB The enriched environment (EC) causes morphological plasticity in striatal cells that express D1 and D2 receptors. We used radioligand binding assays to examine whether EC produces plasticity in striatal receptor density and receptor density ratios. After 30 days of EC, 2-year-old rats had a higher ratio of D1 to muscarinic receptors in striatum relative to singly housed rats. Assays also showed trends for a greater ratio of D1 to cannabinoid receptors and a greater density of D1 receptors in striatum after EC. D2 receptor density was unaffected by the EC condition. (C) 2000 Elsevier Science B.V. All rights reserved. C1 SUNY Stony Brook, Dept Psychol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Program Neurobiol & Behav, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Anderson, BJ (reprint author), SUNY Stony Brook, Dept Psychol, Stony Brook, NY 11794 USA. FU NIMH NIH HHS [MH57845] NR 33 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-8993 J9 BRAIN RES JI Brain Res. PD JUL 28 PY 2000 VL 872 IS 1-2 BP 262 EP 265 DI 10.1016/S0006-8993(00)02507-5 PG 4 WC Neurosciences SC Neurosciences & Neurology GA 341MP UT WOS:000088594400038 PM 10924706 ER PT J AU Axenovich, M AF Axenovich, M TI A generalized Ramsey problem SO DISCRETE MATHEMATICS LA English DT Article AB Let f(n) be the minimum number such that there is a proper edge-coloring of K-n with f(n) colors with no path or cycle of 4 edges using one or two colors. It is shown that [(1 + root 5)/2]n - 3 less than or equal to f(n) less than or equal to 2n(1+cj root log n) for a positive constants c. This improves the existent bounds on the variant of the Ramsey number f(n, 5, 9) studied by Erdos and Gyarfas. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Illinois, Urbana, IL 61801 USA. RP Axenovich, M (reprint author), Iowa State Univ, Ames Lab, 1 Osborn Dr, Ames, IA 50011 USA. NR 4 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-365X J9 DISCRETE MATH JI Discret. Math. PD JUL 28 PY 2000 VL 222 IS 1-3 BP 247 EP 249 DI 10.1016/S0012-365X(00)00052-2 PG 3 WC Mathematics SC Mathematics GA 340DV UT WOS:000088518600019 ER PT J AU Ducros, V Charnock, SJ Derewenda, U Derewenda, ZS Dauter, Z Dupont, C Shareck, F Morosoli, R Kluepfel, D Davies, GJ AF Ducros, V Charnock, SJ Derewenda, U Derewenda, ZS Dauter, Z Dupont, C Shareck, F Morosoli, R Kluepfel, D Davies, GJ TI Substrate specificity in glycoside hydrolase family 10 - Structural and kinetic analysis of the streptomyces lividans xylanase 10A SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID AMINO-ACID-SEQUENCE; CRYSTAL-STRUCTURE; ACTIVE-SITE; ENZYME INTERMEDIATE; ANGSTROM RESOLUTION; MACROMOLECULAR STRUCTURES; THERMOASCUS-AURANTIACUS; BETA-1,4-GLYCANASE CEX; CATALYTIC INTERMEDIATE; MOLECULAR REPLACEMENT AB Endoxylanases are a group of enzymes that hydrolyze the beta-1,4-linked xylose backbone of xylans. They are predominantly found in two discrete sequence families known as glycoside hydrolase families 10 and 11. The Streptomyces lividans xylanase Xyl10A is a family 10 enzyme, the native structure of which has previously been determined by x-ray crystallography at a 2.6 Angstrom resolution (Derewenda, U., Swenson, L., Green, R., Wei, Y., Morosoli, R., Shareck, F., Kluepfel, D., and Derewenda, Z. S. (1994) J. Biol. Chem. 269, 20811-20814). Here, we report the native structure of Xyl10A refined at a resolution of 1.2 Angstrom which reveals many features such as the rare occurrence of a discretely disordered disulfide bond between residues Cys-168 and Cys-201. In order to investigate substrate binding and specificity in glycoside hydrolase family 10, the covalent xylobiosyl enzyme and the covalent cellobiosyl enzyme intermediates of Xyl10A were trapped through the use of appropriate 2-fluoroglycosides. The Lu-linked intermediate with the nucleophile, Glu-236, is in a C-4(1) chair conformation as previously observed in the family 10 enzyme Cex from Cellulomonas fimi (Notenboom, V., Birsan, C., Warren, R. A. J., Withers, S. G., and Rose, D. R. (1998) Biochemistry 37, 4751-4758). The different interactions of Xyl10A with the xylobiosyl and cellobiosyl moieties, notably conformational changes in the -2 and -1 subsites, together with the observed kinetics on a range of aryl glycosides, shed new light on substrate specificity in glycoside hydrolase family 10. C1 Univ York, Dept Chem, Struct Biol Lab, York YO10 5DD, N Yorkshire, England. Univ Virginia, Ctr Hlth Sci, Dept Mol Physiol & Biol Phys, Charlottesville, VA 22906 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Quebec, Inst Armand Frappier, INRS, Inst Microbiol & Biotechnol, Laval, PQ H7V 1B7, Canada. RP Davies, GJ (reprint author), Univ York, Dept Chem, Struct Biol Lab, York YO10 5DD, N Yorkshire, England. RI Davies, Gideon/A-9042-2011 OI Davies, Gideon/0000-0002-7343-776X NR 55 TC 57 Z9 57 U1 0 U2 8 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 JUL 28 PY 2000 VL 275 IS 30 BP 23020 EP 23026 DI 10.1074/jbc.275.30.23020 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 338KV UT WOS:000088419400057 PM 10930426 ER PT J AU Higashimoto, Y Saito, S Tong, XH Hong, A Sakaguchi, K Appella, E Anderson, CW AF Higashimoto, Y Saito, S Tong, XH Hong, A Sakaguchi, K Appella, E Anderson, CW TI Human p53 is phosphorylated on serines 6 and 9 in response to DNA damage-inducing agents SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID CASEIN KINASE-I; PROTEIN; GENE; EXPRESSION; PHOSPHOSERINE; MUTATIONS; ANALOGS; SIGNALS; ISOFORM; GROWTH AB To characterize the sites in human p53 that become phosphorylated in response to DNA damage, we have developed polyclonal antibodies that recognize p53 only when it is phosphorylated at specific sites. Several attempts to generate an antibody to p53 phosphorylated at Ser(6) using a phosphoserine-containing peptide as an immunogen were unsuccessful; however, phosphorylation-specific antibodies were produced by using the phosphoserine mimetic, L-2-amino-4-phosphono-4,4-di-fluorobutanoicacid (F(2)Pab), in place of phosphoserine. Fmoc-F(2)Pab was prepared by an improved synthesis and chemically incorporated using solid phase peptide synthesis, Affinity-purified antibodies elicited by immunizing rabbits with an F(2)Pab peptide coupled to keyhole limpet hemocyanin recognized a p53(1-39) peptide phosphorylated only at Ser(6) but not the unphosphorylated peptide or the same peptide phosphorylated at Ser(9), Ser(15), Ser(20), Ser(33), or Ser(37). Untreated A549 cells exhibited a background of constitutive phosphorylation at Ser(6) that increased approximately 10-fold upon exposure to either ionizing radiation or UV light. Similar results were obtained for Sers using antibodies raised against a conventional phosphopeptide. Ser(9) was phosphorylated by casein kinase 1 in vitro in a phosphoserine 6-dependent manner. Our data identify two additional DNA damage-induced phosphorylations in human p53 and show that F(2)Pab-derivatized peptides can be used to develop phosphorylation site-specific polyclonal antibodies. C1 NCI, NIH, Bethesda, MD 20892 USA. AnaSpec Inc, San Jose, CA 95131 USA. Kyushu Univ, Fac Sci, Dept Chem, Fukuoka 8128581, Japan. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Appella, E (reprint author), NCI, NIH, Bethesda, MD 20892 USA. RI U-ID, Kyushu/C-5291-2016 NR 32 TC 88 Z9 89 U1 0 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 JUL 28 PY 2000 VL 275 IS 30 BP 23199 EP 23203 DI 10.1074/jbc.M002674200 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 338KV UT WOS:000088419400082 PM 10930428 ER PT J AU Cumings, J Zettl, A AF Cumings, J Zettl, A TI Low-friction nanoscale linear bearing realized from multiwall carbon nanotubes SO SCIENCE LA English DT Article ID FORCE MICROSCOPY AB We demonstrate the controlled and reversible telescopic extension of multiwall carbon nanotubes, thus realizing ultralow-friction nanoscale linear bearings and constant-force nanosprings. Measurements performed in situ on individual custom-engineered nanotubes inside a high-resolution transmission electron microscope demonstrated the anticipated van der Waals energy-based retraction force and enabled us to place quantitative limits on the static and dynamic interwall frictional forces between nested nanotubes. Repeated extension and retraction of telescoping nanotube segments revealed no wear or fatigue on the atomic scale. Hence, these nanotubes may constitute near perfect, wear-free surfaces. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Zettl, A (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM azettl@physics.berkeley.edu RI Cumings, John/A-3595-2012; Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 13 TC 915 Z9 936 U1 10 U2 143 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 JUL 28 PY 2000 VL 289 IS 5479 BP 602 EP 604 DI 10.1126/science.289.5479.602 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 338XD UT WOS:000088447800047 ER PT J AU Rosso, KM Rustad, JR AF Rosso, KM Rustad, JR TI Ab initio calculation of homogeneous outer sphere electron transfer rates: Application to M(OH2)(6)(3+/2+) redox couples SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; TRANSFER MATRIX-ELEMENTS; REORGANIZATION ENERGIES; BASIS-SETS; REACTIVE TRANSPORT; EXCHANGE-REACTIONS; SURFACE; WATER; HYDROLYSIS; COMPLEXES AB Ab initio density functional theory calculations are applied to the prediction of homogeneous outer sphere electron transfer rates within the classical Marcus formalism for a series of transition metal hexaquo ions in a background electrolyte. Reorganization energies, frequency factors, electronic transmission coefficients, and the effective electron transfer distances are calculated. Theoretical inner sphere contributions to the reorganization energies correlate very well with total reorganization energies estimated from experimental self-exchange rates. important energy contributions arising from Jahn-Teller distortions are accurately included in the inner sphere term. Effective electron transfer distances are found to be only slightly longer than the sum of the average calculated M-O distances. Calculated adiabatic self-exchange rates agree well with observed self-exchange rates. The driving force for bimolecular electron transfers, calculated from total energy differences, is found to compare well with estimations using experimental reduction potentials to within 4 kJ/mol. The choice of basis set is found to be very important in these calculations, and for this system, the 6-311+G basis set outperforms DZVP. The methods presented provide a convenient means to produce usefully accurate parameters for Marcus theory to predict outer sphere electron transfer rates. C1 Pacific NW Natl Lab, WR WIley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Rosso, KM (reprint author), Pacific NW Natl Lab, WR WIley Environm Mol Sci Lab, POB 999,MSIN K8-96, Richland, WA 99352 USA. NR 55 TC 50 Z9 50 U1 2 U2 18 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 JUL 27 PY 2000 VL 104 IS 29 BP 6718 EP 6725 DI 10.1021/jp994164h PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 339QW UT WOS:000088490300006 ER PT J AU Preses, JM Fockenberg, C Flynn, GW AF Preses, JM Fockenberg, C Flynn, GW TI A measurement of the yield of carbon monoxide from the reaction of methyl radicals and oxygen atoms SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ABSORPTION CROSS-SECTIONS; CH3 RADICALS; KINETICS; O(P-3); SPECTROMETRY; PHOTOLYSIS; PRODUCT; NM AB We have determined the branching fraction for the production of CO from the reaction of methyl radicals and O(P-3) atoms at room temperature to be 0.18 +/- 0.04 at T = 296 K. The measurement was made by determining the concentration of CO using tunable infrared diode laser absorption. Methyl radicals and O atoms were prepared by 193-nm excimer laser photolysis of acetone and SO2. CO produced directly from acetone photolysis was distinguished from that generated by the radical-radical reaction by using acetone labeled with C-13 only on the methyl groups. The result is in excellent agreement with another determination of the CO branching fraction made using time-of-flight mass spectrometry. C1 Brookhaven Natl Lab, Chem Dept 555A, Upton, NY 11973 USA. Columbia Univ, Dept Chem, New York, NY 10027 USA. RP Preses, JM (reprint author), Brookhaven Natl Lab, Chem Dept 555A, POB 5000, Upton, NY 11973 USA. NR 18 TC 23 Z9 23 U1 0 U2 2 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 JUL 27 PY 2000 VL 104 IS 29 BP 6758 EP 6763 DI 10.1021/jp000404d PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 339QW UT WOS:000088490300011 ER PT J AU Engelke, R Sheffield, SA Davis, LL AF Engelke, R Sheffield, SA Davis, LL TI Experimental and predicted detonation parameters for liquid-phase H2O2/H2O mixtures SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article AB We report the measured failure diameter and a detonation speed for the liquid explosive mixture 90.5/9.5 wt % H2O2/H2O confined in thick seamless 304 stainless steel tubing and Fired at ca. 30 degrees C. The detonation speed datum and knowledge of the diameter effect curves of other liquid explosives are used to estimate the infinite-medium (i.e., planewave) detonation speed of this material. Ambient condition sound speed measurements and the universal liquid Hugoniot form are used to obtain the unreacted Hugoniot of the 90.5/9.5 wt % H2O2/H2O mixture. This Hugoniot and the Rayleigh line obtained From the estimated infinite-medium detonation wave speed are used to predict the von Neumann spike pressure of the material. Estimates of the fully reacted (i.e., products) Hugoniot, the Chapman-Jouguet (CJ) detonation pressure, and CJ detonation speed for other H2O2/H2O mixtures are obtained using the CHEETAH equilibrium thermochemical code. Predictions of the infinite-medium detonation speed and the von Neumann spike and CJ pressures of 85.0/15.0, 90.0/10.0, 92.5/7.5, 95.0/5.0, 7.5/2.5, and 100.0/0.0 wt % H2O2/H2O mixtures are also obtained. A general analytical expression is given for the primary shock Hugoniot of any H2O2/H2O mixture at 22.6 degrees C. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Engelke, R (reprint author), Univ Calif Los Alamos Natl Lab, MS P952, Los Alamos, NM 87545 USA. NR 18 TC 11 Z9 11 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUL 27 PY 2000 VL 104 IS 29 BP 6894 EP 6898 DI 10.1021/jp000953j PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 339QW UT WOS:000088490300028 ER PT J AU Retsek, JL Gentemann, S Medforth, CJ Smith, KM Chirvony, VS Fajer, J Holten, D AF Retsek, JL Gentemann, S Medforth, CJ Smith, KM Chirvony, VS Fajer, J Holten, D TI Photoinduced evolution on the conformational landscape of nonplanar dodecaphenylporphyrin: Picosecond relaxation dynamics in the (1)(pi,pi*) excited state SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID PHOTOSYNTHETIC REACTION-CENTER; PHOTOPHYSICAL PROPERTIES; SUBSTITUTED PORPHYRINS; OPTICAL-PROPERTIES; ENERGY-TRANSFER; RESOLUTION; BACTERIOCHLOROPHYLL; METALLOPORPHYRIN; PROTEIN; MODEL AB The early events following photoexcitation of the nonplanar porphyrin 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrin (H2DPP) have been examined using transient absorption spectroscopy. These studies were motivated by previous results indicating that photoinduced conformational changes underlie many of the perturbed photophysical properties of nonplanar porphyrins. It is shown here that H2DPP undergoes conformational/vibrational relaxation and equilibration in the (1)(pi,pi*) excited state that takes similar to 10 ps, and that this process is not observed for the nominally planar 5,10,15,20-tetraphenylporphyrin system. The relaxation dynamics in H2DPP likely involve out-of-plane deformations of the porphyrin macrocycle and motions of the peripheral phenyl rings and solvent molecules. The light-induced behavior of H2DPP can thus be described by the following sequence of events: photoexcitation produces the unrelaxed (1)(pi,pi*) excited state that evolves into the relaxed (1)(pi,pi*) excited state in similar to 10 ps, followed by decay to the (3)(pi,pi*) excited state plus the ground state in similar to 1 ns. C1 Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Natl Acad Sci Belarus, Inst Atom & Mol Phys, Minsk 220072, Byelarus. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Holten, D (reprint author), Washington Univ, Dept Chem, St Louis, MO 63130 USA. RI Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 31 TC 40 Z9 40 U1 1 U2 2 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 JUL 27 PY 2000 VL 104 IS 29 BP 6690 EP 6693 DI 10.1021/jp001586e PG 4 WC Chemistry, Physical SC Chemistry GA 339QY UT WOS:000088490500003 ER PT J AU Afanasiev, SV Anticic, T Bachler, J Barna, D Barnby, LS Bartke, J Barton, RA Betev, L Bialkowska, H Billmeier, A Blume, C Blyth, CO Boimska, B Bracinik, J Brady, FP Brun, R Buncic, P Carr, L Cebra, D Cooper, GE Cramer, JG Csato, P Eckardt, V Eckhardt, F Ferenc, D Fischer, HG Fodor, Z Foka, P Freund, P Friese, V Ftacnik, J Gal, J Ganz, R Gazdzicki, M Gladysz, E Grebieszkow, J Harris, JW Hegyi, S Hlinka, V Hohne, C Igo, G Ivanov, M Jacobs, P Janik, R Jones, PG Kadija, K Kolesnikov, VI Kowalski, M Lasiuk, B Levai, P Malakhov, AI Margetis, S Markert, C Mayes, BW Melkumov, GL Mischke, A Molnar, J Nelson, JM Odyniec, G Oldenburg, MD Palla, G Panagiotou, AD Petridis, A Pikna, M Pinsky, L Poskanzer, AM Prindle, DJ Puhlhofer, F Reid, JG Renfordt, R Retyk, W Ritter, HG Rohrich, D Roland, C Roland, G Rybicki, A Sammer, T Sandoval, A Sann, H Semenov, AY Schafer, E Schmitz, N Seyboth, P Sikler, F Sitar, B Skrzypczak, E Snellings, R Squier, GTA Stock, R Strmen, P Strobele, H Struck, C Susa, T Szarka, I Szentpetery, I Sziklai, J Toy, M Trainor, TA Trentalange, S Ullrich, T Varga, D Vassiliou, M Veres, GI Vesztergombi, G Voloshin, S Vranic, D Wang, F Weerasundara, DD Wenig, S Whitten, C Xu, N Yates, TA Yoo, IK Zimanyi, J AF Afanasiev, SV Anticic, T Bachler, J Barna, D Barnby, LS Bartke, J Barton, RA Betev, L Bialkowska, H Billmeier, A Blume, C Blyth, CO Boimska, B Bracinik, J Brady, FP Brun, R Buncic, P Carr, L Cebra, D Cooper, GE Cramer, JG Csato, P Eckardt, V Eckhardt, F Ferenc, D Fischer, HG Fodor, Z Foka, P Freund, P Friese, V Ftacnik, J Gal, J Ganz, R Gazdzicki, M Gladysz, E Grebieszkow, J Harris, JW Hegyi, S Hlinka, V Hohne, C Igo, G Ivanov, M Jacobs, P Janik, R Jones, PG Kadija, K Kolesnikov, VI Kowalski, M Lasiuk, B Levai, P Malakhov, AI Margetis, S Markert, C Mayes, BW Melkumov, GL Mischke, A Molnar, J Nelson, JM Odyniec, G Oldenburg, MD Palla, G Panagiotou, AD Petridis, A Pikna, M Pinsky, L Poskanzer, AM Prindle, DJ Puhlhofer, F Reid, JG Renfordt, R Retyk, W Ritter, HG Rohrich, D Roland, C Roland, G Rybicki, A Sammer, T Sandoval, A Sann, H Semenov, AY Schafer, E Schmitz, N Seyboth, P Sikler, F Sitar, B Skrzypczak, E Snellings, R Squier, GTA Stock, R Strmen, P Strobele, H Struck, C Susa, T Szarka, I Szentpetery, I Sziklai, J Toy, M Trainor, TA Trentalange, S Ullrich, T Varga, D Vassiliou, M Veres, GI Vesztergombi, G Voloshin, S Vranic, D Wang, F Weerasundara, DD Wenig, S Whitten, C Xu, N Yates, TA Yoo, IK Zimanyi, J TI Deuteron production in central Pb plus Pb collisions at 158A GeV SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; CENTRAL PB+PB COLLISIONS; HADRON DISTRIBUTIONS; COLLECTIVE EXPANSION; PARTICLE-PRODUCTION; EXPERIMENT NA49; COALESCENCE; MOMENTUM; PARAMETERS AB Experimental results on deuteron emission from central Pb + Pb collisions (E-beam = 158A GeV, fixed target), obtained by NA49 at the CERN SPS accelerator, are presented. The transverse mass in, distribution was measured near mid-rapidity (2.0 < y < 2.5) in the range of 0 < m(t) - m(0) < 0.9 GeV/c(2) (0 < p(t) < 2.0 GeV/c) for the 4% most central collisions. An exponential fit gives an inverse slope T-d = (450 +/- 30) MeV and a yield dN(d)/dy = 0.34 +/- 0.03. The coalescence factor B-2 (m(t) = m(0))=(3.5 +/- 1.0) . 10(-4) GeV2 and its m(t)-dependence are deter-mined and discussed in terms of a model that includes the collective expansion of the source created in a collision. The derived Gaussian size parameter R-G Of the emission volume is consistent with earlier HBT results on the source of pion emission. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Joint Inst Nucl Res, Dubna, Russia. Univ Athens, Dept Phys, Athens, Greece. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Birmingham, Birmingham, W Midlands, England. Slovak Acad Sci, Inst Phys, Bratislava, Slovakia. KFKI Res Inst Particle & Nucl Phys, Budapest, Hungary. CERN, Geneva, Switzerland. Inst Nucl Phys, Krakow, Poland. Gesell Schwerionenforsch mbH, Darmstadt, Germany. Univ Calif Davis, Davis, CA 95616 USA. Goethe Univ Frankfurt, Fachbereich Phys, D-6000 Frankfurt, Germany. Univ Houston, Houston, TX USA. Kent State Univ, Kent, OH 44242 USA. Univ Calif Los Angeles, Los Angeles, CA USA. Univ Marburg, Fachbereich Phys, D-3550 Marburg, Germany. Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany. Inst Nucl Studies, PL-00681 Warsaw, Poland. Univ Warsaw, Inst Expt Phys, Warsaw, Poland. Univ Washington, Nucl Phys Lab, Seattle, WA 98195 USA. Yale Univ, New Haven, CT USA. Rudjer Boskovic Inst, Zagreb, Croatia. RP Joint Inst Nucl Res, Dubna, Russia. EM melkumov@moonhe.jinr.ru RI Barnby, Lee/G-2135-2010; Mischke, Andre/D-3614-2011; Voloshin, Sergei/I-4122-2013; Levai, Peter/A-1544-2014; Carr, Lincoln/E-3819-2016 OI Barnby, Lee/0000-0001-7357-9904; Carr, Lincoln/0000-0002-4848-7941 NR 49 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUL 27 PY 2000 VL 486 IS 1-2 BP 22 EP 28 DI 10.1016/S0370-2693(00)00746-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 341LE UT WOS:000088591200004 ER PT J AU Wang, HB Wang, HH Urban, VS Littrell, KC Thiyagarajan, P Yu, LP AF Wang, HB Wang, HH Urban, VS Littrell, KC Thiyagarajan, P Yu, LP TI Syntheses of amphiphilic diblock copolymers containing a conjugated block and their self-assembling properties SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MORPHOLOGIES; POLYMERS; MICELLES; LENGTH AB An efficient approach to the syntheses of amphiphilic rod-coil diblock and coil-rod-coil triblock copolymers was developed. Each diblock copolymer consists of a perfectly monodispersed oligo(phenylene vinylene) covalently bonded to a poly(ethylene glycol) block with a very low polydispersity (<1.05). The structure and basic physical properties of these copolymers were characterized by various spectroscopic techniques such as NMR, MALDI-TOF, GPC, DSC, UV/vis, and the fluorescence study. These diblock copolymers were shown to possess remarkable self-assembling abilities, and long cylindrical micelles ttl mu m) were formed. TEM, SANS, and AFM studies showed that the core of the micelles has a diameter of similar to 8-10 nm and was composed of an OPV block. TEM and SANS studies revealed that these OPV-PEG micelles have a cylindrical OPV core surrounded by a PEG corona. Cryo-TEM and SANS studies indicate that fibers were formed even in very dilute TKF/H2O solutions. Since the conjugated OPV blocks exhibit liquid crystallinity and electric and optical properties, these micelles are interesting for studying the electroactive effect in a nanometer scale. C1 Argonne Natl Lab, Div Chem & Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Yu, LP (reprint author), Argonne Natl Lab, Div Chem & Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Urban, Volker/N-5361-2015; Littrell, Kenneth/D-2106-2013 OI Urban, Volker/0000-0002-7962-3408; Littrell, Kenneth/0000-0003-2308-8618 NR 36 TC 166 Z9 170 U1 5 U2 65 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 JUL 26 PY 2000 VL 122 IS 29 BP 6855 EP 6861 DI 10.1021/ja0010812 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 340FP UT WOS:000088522700007 ER PT J AU Shaw, WJ Long, JR Campbell, AA Stayton, PS Drobny, GP AF Shaw, WJ Long, JR Campbell, AA Stayton, PS Drobny, GP TI A solid state NMR study of dynamics in a hydrated salivary peptide adsorbed to hydroxyapatite SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MAGNETIC-RESONANCE; CALCIUM-PHOSPHATE; MAGIC-ANGLE; PRECIPITATION; CONFORMATION; INHIBITION; STATHERIN C1 Univ Washington, Dept Bioengn, Seattle, WA 98195 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Stayton, PS (reprint author), Univ Washington, Dept Bioengn, Seattle, WA 98195 USA. NR 15 TC 46 Z9 47 U1 2 U2 8 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 JUL 26 PY 2000 VL 122 IS 29 BP 7118 EP 7119 DI 10.1021/ja000878q PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 340FP UT WOS:000088522700037 ER PT J AU Langen, R Oh, KJ Cascio, D Hubbell, WL AF Langen, R Oh, KJ Cascio, D Hubbell, WL TI Crystal structures of spin labeled T4 lysozyme mutants: Implications for the interpretation of EPR spectra in terms of structure SO BIOCHEMISTRY LA English DT Article ID O HYDROGEN-BOND; MEMBRANE-PROTEINS; DYNAMICS; RESOLUTION; RESONANCE; DISULFIDE; MOTION AB High resolution (1.43-1.8 Angstrom) crystal structures and the corresponding electron paramagnetic resonance (EPR) spect-ra were determined for T4 lysozyme derivatives with a disulfide-linked nitroxide side chain [-CH2-S-S-CH2-(3-[2,2,5,5-tetramethyl pyrroline-1-oxyl]) = R1] substituted at solvent-exposed helix surface sites (Lys65, Arg80, Arg119) or a tertiary contact site (Va175). In each case, electron density is clearly resolved for the disulfide group, revealing distinct rotamers of the side chain, defined by the dihedral angles X-1 and X-2. The electron density associated with the nitroxide ring in the different mutants is inversely correlated with its mobility determined from the EPR spectrum. Residue 80R1 assumes a single g(+)g(+) conformation (X-1 = 286, X-2 = 294). Residue 119R1 has two EPR spectral components, apparently corresponding to two rotamers, one similar to that for 80R1 and the other in a tg(-) conformation (X-1 = 175, X-2 = 54). The latter state is apparently stabilized by interaction of the disulfide with a Gin at i + 4, a situation also observed at 65R1. R1 residues at helix surface site 65 and tertiary contact site 75 make intra- as well as intermolecular contacts in the crystal and serve to identify the kind of molecular interactions possible for the R1 side chain. A single conformation of the entire 75R1 side chain is stabilized by a variety of interactions with the nitroxide ring, including hydrophobic contacts and two unconventional C-H ... O hydrogen bonds, one in which the nitroxide acts as a donor (with tyrosine) and the other in which it acts as an acceptor (with phenylalanine). The interactions revealed in these structures provide an important Link between the dynamics of the R1 side chain, reflected in the EPR spectrum, and local protein structure. A Library of such interactions will provide a basis for the quantitative interpretation of EPR spectra in terms of protein structure and dynamics. C1 Univ Calif Los Angeles, Jules Stein Eye Inst, Sch Med, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Biochem & Chem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, US DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. RP Cascio, D (reprint author), Univ Calif Los Angeles, Jules Stein Eye Inst, Sch Med, Los Angeles, CA 90095 USA. FU NEI NIH HHS [EY05216, EY06809] NR 32 TC 206 Z9 208 U1 0 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 25 PY 2000 VL 39 IS 29 BP 8396 EP 8405 DI 10.1021/bi000604f PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 337TC UT WOS:000088376900006 PM 10913245 ER PT J AU Landgraf, R Eisenberg, D AF Landgraf, R Eisenberg, D TI Heregulin reverses the oligomerization of HER3 SO BIOCHEMISTRY LA English DT Article ID GROWTH-FACTOR RECEPTOR; TYROSINE KINASE-ACTIVITY; EGF RECEPTOR; HUMAN-BREAST; DIFFERENTIATION FACTOR; EXTRACELLULAR DOMAIN; ACTIVATION; ERBB3; BINDING; LIGAND AB We analyzed the propensity of the HER3 receptor and its extracellular domain (ECD) to undergo ligand-independent self-association. The HER3-ECD, purified from Drosophila S2 cells, binds the EGF-like domain of heregulin (hrg) with a Kd of 1.9 nM as measured by surface plasmon resonance (SPR) studies. In a gel shift assay, the HER3-ECD self-associates into a uniform, slowly migrating species in a concentration-dependent manner, starting at concentrations of <10 nM. In contrast to the HER3-ECD, the ECD from the related HER2 receptor does not oligomerize under the same conditions. The direct interaction of HER3-ECDs was also demonstrated by pull-down assays and SPR measurements under physiological salt conditions. This self-association of the HER3-ECD was reversed by the addition of hrg but not by EGF. The apparent equilibrium dissociation constant for the HER3-ECD self-association is 15 nM, based on SPR measurements. In this analysis, hrg blocks HER3-ECD self-association, and the addition of hrg during the dissociation phase resulted in an accelerated off rate. This finding suggests that hrg can bind to and disrupt preexisting HER3-ECD oligomers. Full-length HER3 likewise exhibited self-association. Under conditions where co-immunoprecipitation and cross-linking of HER2 and HER3 were stimulated by hrg, HER3 self-association and cross-linking were disrupted by hrg. The implication is that the self-association of HER3-ECD favors the formation of catalytically inactive complexes of the HER3 receptor. Binding of hrg releases HER3 which may then form signaling-competent HER3-HER2 heterodimers. C1 Univ Calif Los Angeles, US DOE, Inst Mol Biol, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. RP Eisenberg, D (reprint author), Univ Calif Los Angeles, US DOE, Inst Mol Biol, Lab Struct Biol & Mol Med, Box 951570, Los Angeles, CA 90095 USA. NR 40 TC 36 Z9 37 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 25 PY 2000 VL 39 IS 29 BP 8503 EP 8511 DI 10.1021/bi000953+ PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 337TC UT WOS:000088376900017 PM 10913256 ER PT J AU Kim, SH Vurens, G Somorjai, GA AF Kim, SH Vurens, G Somorjai, GA TI Direct measurement of polymer growth rate in a model Ziegler-Natta polymerization system using laser reflection interferometry SO JOURNAL OF CATALYSIS LA English DT Article DE Ziegler-Natta; TiCl4; MgCl2; polymerization kinetics; deactivation; laser reflection interferometry ID PARAMETER; CATALYST AB The polymer growth rate for polypropylene and polyethylene was measured, for the first time, during polymerization on a model Ziegler-Natta catalyst film with a surface area of similar to 1 cm(2) by laser reflection interferometry. This technique is based on the difference in the refractive indices of the catalyst and the growing polymer film. A thin film of TiClx/MgCl2 deposited on a polycrystalline gold foil was used as a model catalyst. Polyethylene grew about 30 times faster than polypropylene. The changes in periodicity of the interference fringes indicated a slow decrease in the growth rate with increasing polymer film thickness. This may be due to the monomer diffusion that was controlled by the thickness and morphology of the growing polymer film. (C) 2000 Academic Press. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. HDI Instrumentat, Santa Clara, CA 95050 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 17 TC 12 Z9 12 U1 1 U2 2 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 JUL 25 PY 2000 VL 193 IS 2 BP 171 EP 175 DI 10.1006/jcat.2000.2917 PG 5 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 339QD UT WOS:000088488700001 ER PT J AU Jung, KD Bell, AT AF Jung, KD Bell, AT TI Role of hydrogen spillover in methanol synthesis over Cu/ZrO2 SO JOURNAL OF CATALYSIS LA English DT Article DE hydrogen spill over; methanol synthesis; Cu/ZrO2 ID COPPER-ZIRCONIA CATALYSTS; TEMPERATURE-PROGRAMMED DESORPTION; CARBON-DIOXIDE; AEROGEL CATALYSTS; SYNTHESIS MECHANISM; CU-ZRO2 CATALYSTS; CO2 HYDROGENATION; ADSORPTION; SURFACE; CU/SIO2 AB Recent studies have shown that the synthesis of methanol from both CO and CO2 over Cu/ZrO2 involves the spillover of H atoms formed on Cu to the surface of ZrO2. The atomic H then participates in the hydrogenation of carbon-containing species (i.e., HCOO-Zr and HCO3-Zr) to methanol. The present study examines the dynamics of H/D exchange of HO-Zr, HCOO-Zr, and CH3O-Zr groups present on the surface of ZrO2 and Cu/ZrO2 by means of in situ infrared spectroscopy. The rate of H/D exchange of HO-Zr groups is much more rapid in the presence than in the absence of Cu dispersed on the surface of ZrO2. This effect is attributed to the higher effectiveness of Cu to dissociate H-2(D-2). While adsorbed water significantly inhibits the rate of H/D exchange on ZrO2, the opposite effect is observed for Cu/ZrO2. The reason is that adsorbed water inhibits the dissociation of H-2(D-2) on the surface of ZrO2 but not on the surface of Cu. Adsorbed water facilitates the transport of H(D) atoms formed on the surface of Cu across the surface of ZrO2 as a consequence of hydrogen bonding between adsorbed H2O and HO-Zr groups. Formate groups are formed on the surface of ZrO2 primarily via the process CO(g) + HO-Zr --> HCOO-Zr. Formate groups can also form on the surface of Cu and spill over onto the surface of ZrO2. The presence of formate groups inhibits the rate of H/D exchange of HO-Zr groups. H/D exchange of HCOO-Zr is also observed but occurs at a slower rate than the isotopic exchange of HO-Zr groups. As in the absence of formate groups, adsorbed water inhibits the rate of HID exchange for ZrO2 but enhances it for Cu/ZrO2. The dynamics of H/D exchange are compared with the dynamics of methanol formation as measured by the rate of CH3O-Zr formation on Cu/ZrO2. On the basis of this analysis it is concluded that the rate of hydrogen spillover from Cu is more than an order of magnitude faster than the rate of methanol formation, and, hence, not a rate-limiting step in the synthesis of methanol over Cu/ZrO2. (C) 2000 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 Bell, AT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 44 TC 102 Z9 106 U1 5 U2 85 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 JUL 25 PY 2000 VL 193 IS 2 BP 207 EP 223 DI 10.1006/jcat.2000.2881 PG 17 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 339QD UT WOS:000088488700005 ER PT J AU Coulthard, I Antel, WJ Freeland, JW Sham, TK Naftel, SJ Zhang, P AF Coulthard, I Antel, WJ Freeland, JW Sham, TK Naftel, SJ Zhang, P TI Influence of sample oxidation on the nature of optical luminescence from porous silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID ABSORPTION FINE-STRUCTURE; ROOM-TEMPERATURE; K-EDGE; PHOTOLUMINESCENCE; SI; OXYGEN; DEFECT; SPECTROSCOPY AB Site-selective luminescence experiments were performed upon porous-silicon samples exposed to varying degrees of oxidation. The source of different luminescence bands was determined to be due to either quantum confinement in nanocrystalline silicon or defective silicon oxide. Of particular interest is the defective silicon-oxide luminescence band found at 2.1 eV, which was found to frequently overlap with a luminescence band from nanocrystalline silicon. Some of the historical confusion and debate with regards to the source of luminescence from porous silicon can be attributed to this overlap. (C) 2000 American Institute of Physics. [S0003-6951(00)01330-9]. C1 Argonne Natl Lab, Expt Facilities Div, Argonne, IL 60439 USA. Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. RP Coulthard, I (reprint author), Argonne Natl Lab, Expt Facilities Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zhang, Peng/K-5174-2012 OI Zhang, Peng/0000-0003-3603-0175 NR 24 TC 26 Z9 26 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 24 PY 2000 VL 77 IS 4 BP 498 EP 500 DI 10.1063/1.127023 PG 3 WC Physics, Applied SC Physics GA 335CX UT WOS:000088225400013 ER PT J AU Loffler, JF Bossuyt, S Glade, SC Johnson, WL Wagner, W Thiyagarajan, P AF Loffler, JF Bossuyt, S Glade, SC Johnson, WL Wagner, W Thiyagarajan, P TI Crystallization of bulk amorphous Zr-Ti(Nb)-Cu-Ni-Al SO APPLIED PHYSICS LETTERS LA English DT Article ID SUPERCOOLED LIQUID; DECOMPOSITION; GLASS; ALLOYS; ZR41TI14CU12.5NI10BE22.5; DIFFUSION; MELTS; NI AB Small-angle neutron scattering (SANS) and transmission electron microscopy were used to resolve the crystallization of the bulk amorphous alloys Zr52.5Ti5Cu17.9Ni14.6Al10 (Vit105) and Zr57Nb5Cu15.4Ni12.6Al10 (Vit106). Decomposition and nanocrystallization were observed in both alloy compositions in the temperature regime from the glass transition, T-g, up to at least 90 K above T-g. From in situ SANS measurements on Vit105, chemical diffusion data were obtained whose temperature dependence follows an Arrhenius law. Normalizing the temperature to T-g, the diffusion data of Vit105 are very similar to those of the well-investigated bulk amorphous alloy Zr41.2Ti13.8Cu12.5Ni10Be22.5. (C) 2000 American Institute of Physics. [S0003- 6951(00)04930-5]. C1 CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Argonne Natl Lab, IPNS Div, Argonne, IL 60439 USA. RP CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. EM loeffler@caltech.edu RI Bossuyt, Sven/H-5660-2012 OI Bossuyt, Sven/0000-0002-9223-735X NR 18 TC 45 Z9 46 U1 1 U2 12 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 JUL 24 PY 2000 VL 77 IS 4 BP 525 EP 527 AR PII [S0003-6951(00)04930-5] PG 3 WC Physics, Applied SC Physics GA 335CX UT WOS:000088225400022 ER PT J AU Dulli, H Plummer, EW Dowben, PA Choi, J Liou, SH AF Dulli, H Plummer, EW Dowben, PA Choi, J Liou, SH TI Surface electronic phase transition in colossal magnetoresistive manganese perovskites: La0.65Sr0.35MnO3 SO APPLIED PHYSICS LETTERS LA English DT Article AB We have observed a distinct surface phase transition for an important class of giant magnetoresistance materials [La1-xSrxMnO3(x=0.35)]. The surface phase transition occurs at 240 K compared to 370 K for the bulk and is fundamentally different. In the bulk, a ferromagnetic metal to paramagnetic bad-metal transition occurs, while the lower-temperature surface transition is from an insulator to a semimetal. The surface of this manganese perovskite is electronically and compositionally quite different from the bulk with important implications for the behavior of artificially grown layered transition-metal oxides and for the use of surface sensitive techniques to probe the bulk. (C) 2000 American Institute of Physics. [S0003-6951(00)00630-6]. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. Univ Nebraska, Ctr Mat Res & Anal, Behlen Lab Phys, Lincoln, NE 68588 USA. RP Dulli, H (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. NR 10 TC 45 Z9 46 U1 2 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 24 PY 2000 VL 77 IS 4 BP 570 EP 572 DI 10.1063/1.127047 PG 3 WC Physics, Applied SC Physics GA 335CX UT WOS:000088225400037 ER PT J AU Gao, HJ Duscher, G Kim, M Pennycook, SJ Kumar, D Cho, KG Singh, RK AF Gao, HJ Duscher, G Kim, M Pennycook, SJ Kumar, D Cho, KG Singh, RK TI Cathodoluminescent properties at nanometer resolution through Z-contrast scanning transmission electron microscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; PHOSPHORS; GROWTH; LUMINESCENCE; DEGRADATION; SILICON; Y2O3-EU AB We report the observation of porous structures in laser-ablation-deposited Y2O3:Eu thin films and their correlation with luminescent properties by a combination of transmission electron microscopy and Z-contrast scanning transmission electron microscopy (Z-STEM). Depending on growth conditions, a large density of voids is incorporated into the films, which leads to a much increased surface area. Cathodoluminescence imaging in the STEM directly reveals a 5 nm "dead layer" around each void, which is responsible for the observed reduction in luminescence efficiency. (C) 2000 American Institute of Physics. [S0003- 6951(00)05229-3]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Gao, HJ (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Duscher, Gerd/G-1730-2014; Kim, Miyoung/C-8316-2012 OI Duscher, Gerd/0000-0002-2039-548X; NR 18 TC 7 Z9 8 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 24 PY 2000 VL 77 IS 4 BP 594 EP 596 AR PII [S0003-6951(00)05229-3] DI 10.1063/1.127055 PG 3 WC Physics, Applied SC Physics GA 335CX UT WOS:000088225400045 ER PT J AU Scholz, G Curtiss, LA AF Scholz, G Curtiss, LA TI Ab initio molecular orbital study of Fe2Cl6 and FeAlCl6 SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE ab initio study; Fe2Cl6; FeAlCl6 ID IRON(III) CHLORIDE; BASIS-SETS; POTENTIALS; DYNAMICS; SPECTRA; FECL3 AB Ab initio molecular orbital theory was used to determine the equilibrium structure and vibrational frequencies of Fe2Cl6 and FeAlCl6. The equilibrium structure the Fe2Cl6 dimer has D-2h symmetry with a planar arrangement of the four membered {FeClbrFeClbr} ring, similar to the Al2Cl6 dimer. The calculated bond distances and vibrational frequencies are in good agreement with experiment. The potential energy surface for the puckering of the {FeClbrFeClbr} ring is extremely flat. This prevents an unambiguous assignment of either D-2h or C-2v symmetry to the Fe2Cl6 structure in electron diffraction measurements. The FeAlCl6 molecule is found to have a C-2v structure similar to Fe2Cl6 with vibrational frequencies in good agreement with experiment. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Humboldt Univ, Inst Chem, D-10115 Berlin, Germany. Argonne Natl Lab, Div Mat Sci, Div Chem, Argonne, IL 60439 USA. RP Scholz, G (reprint author), Humboldt Univ, Inst Chem, Hess Str 1-2, D-10115 Berlin, Germany. NR 27 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD JUL 24 PY 2000 VL 507 BP 245 EP 251 DI 10.1016/S0166-1280(99)00402-9 PG 7 WC Chemistry, Physical SC Chemistry GA 336MH UT WOS:000088305800026 ER PT J AU Kim, KJ Wang, CX AF Kim, KJ Wang, CX TI Formulas for transverse ionization cooling in solenoidal focusing channels SO PHYSICAL REVIEW LETTERS LA English DT Article AB Ionization cooling in solenoidal channels, such as that envisioned for the future muon colliders or neutrino factories, is studied. Assuming that the interaction with thr ionization material is weak, the evolution of the transverse emittance and angular momentum can be determined analytically. Simple and practical formulas are derived for a general cooling configuration as well as for periodic channels. The prediction of these formulas agrees well with those obtained from simulation codes. The method developed here should be useful to other areas of beam physics involving solenoidal focusing. C1 Univ Chicago, Chicago, IL 60637 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kim, KJ (reprint author), Univ Chicago, 5270 S Ellis Ave, Chicago, IL 60637 USA. NR 16 TC 24 Z9 24 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 JUL 24 PY 2000 VL 85 IS 4 BP 760 EP 763 DI 10.1103/PhysRevLett.85.760 PG 4 WC Physics, Multidisciplinary SC Physics GA 336PL UT WOS:000088311800020 ER PT J AU Penn, G Wurtele, JS AF Penn, G Wurtele, JS TI Beam envelope equations for cooling of muons in solenoid fields SO PHYSICAL REVIEW LETTERS LA English DT Article AB Muon cooling is a critical component of the proposed muon collider and neutrino factory. Previous studies of cooling channels have tracked single muons through the channel, which requires many particles for good statistics and does not lend itself to an understanding of channel dynamics. In this paper, a system of moment equations are derived which captures the major aspects of cooling: interactions with material and acceleration by radio frequency (rf) cavities. A general analysis of solenoid lattice types compares well with prior simulations and indicates new directions for study. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley Ctr Beam Phys, Dept Phys, Berkeley, CA 94720 USA. RP Penn, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley Ctr Beam Phys, Dept Phys, Berkeley, CA 94720 USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 14 TC 22 Z9 22 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 JUL 24 PY 2000 VL 85 IS 4 BP 764 EP 767 DI 10.1103/PhysRevLett.85.764 PG 4 WC Physics, Multidisciplinary SC Physics GA 336PL UT WOS:000088311800021 ER PT J AU Stoldt, CR Caspersen, KJ Bartelt, MC Jenks, CJ Evans, JW Thiel, PA AF Stoldt, CR Caspersen, KJ Bartelt, MC Jenks, CJ Evans, JW Thiel, PA TI Using temperature to tune film roughness: Nonintuitive behavior in a simple system SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; GROWTH; INSTABILITY; DIFFUSION; HOMOEPITAXY; DYNAMICS; MODELS AB Ag(100) homoepitaxy constitutes one of the simplest systems in which to study thin-film growth. Yet we find that the roughness variation with temperature is extraordinarily complex. Specifically, as the deposition temperature is reduced from 300 to 50 K, the roughness of 35 monolayer films first increases, then decreases, then increases again. A transition from mound formation to self-affine (semifractal) growth occurs at similar to 135 K. The underlying mechanisms are postulated. An atomistic model incorporating these mechanisms reproduces the experimental data quantitatively. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Stoldt, CR (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 19 TC 53 Z9 53 U1 1 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 24 PY 2000 VL 85 IS 4 BP 800 EP 803 DI 10.1103/PhysRevLett.85.800 PG 4 WC Physics, Multidisciplinary SC Physics GA 336PL UT WOS:000088311800030 ER PT J AU Valla, T Fedorov, AV Johnson, PD Li, Q Gu, GD Koshizuka, N AF Valla, T Fedorov, AV Johnson, PD Li, Q Gu, GD Koshizuka, N TI Temperature dependent scattering rates at the Fermi surface of optimally doped Bi2Sr2CaCu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; T-C SUPERCONDUCTORS; GAP ANISOTROPY; NORMAL-STATE AB For optimally doped Bi2Sr2CaCu2O8+delta, scattering rates in the normal state are found to have a linear temperature dependence over most of the Fermi surface. In the immediate vicinity of the (pi, 0) point, thr scattering rates are nearly constant in the normal state, consistent with models in which scattering at this point determines the c-axis transport. In the superconducting stale, the scattering rates away from the nodal direction appear to level off and become temperature independent. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 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 21 TC 139 Z9 139 U1 3 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 24 PY 2000 VL 85 IS 4 BP 828 EP 831 DI 10.1103/PhysRevLett.85.828 PG 4 WC Physics, Multidisciplinary SC Physics GA 336PL UT WOS:000088311800037 ER PT J AU Lake, B Tennant, DA Nagler, SE AF Lake, B Tennant, DA Nagler, SE TI Novel longitudinal mode in the coupled quantum chain compound KCuF3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC EXCITATIONS; ORDERED PHASE; SPIN DYNAMICS; NEUTRON; FIELD AB Inelastic neutron scattering measurements are reported that show a new longitudinal mode in the antiferromagnetically ordered phase of the spin-1/2 quasi-one-dimensional antiferromagnet KCuF3. This mode signals the crossover from one-dimensional to three-dimensional behavior and indicates a reduction in the ordered spin moment of a spin-1/2 antiferromagnet. The measurements an compared with recent quantum field theory calculations and are found to be in excellent agreement. A feature of the data not predicted by theory is a damping of the mode by decay processes to the transverse spin-wave branches. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Tennant, DA (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010; Tennant, David/Q-2497-2015; OI Nagler, Stephen/0000-0002-7234-2339; Tennant, David/0000-0002-9575-3368; Lake, Bella/0000-0003-0034-0964 NR 17 TC 52 Z9 52 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 24 PY 2000 VL 85 IS 4 BP 832 EP 835 DI 10.1103/PhysRevLett.85.832 PG 4 WC Physics, Multidisciplinary SC Physics GA 336PL UT WOS:000088311800038 ER PT J AU Schmalian, J Wolynes, PG AF Schmalian, J Wolynes, PG TI Stripe glasses: Self-generated randomness in a uniformly frustrated system SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE-SEPARATION; SPIN-GLASS; TRANSITION; DYNAMICS; MODEL; SUPERCONDUCTIVITY; LA2-XSRXCUO4; TEMPERATURE; ORDER AB We show that a system with competing interactions on different length scales, relevant to the formation of stripes in doped Mott insulators, undergoes a self-generated glass transition which is caused by the frustrated nature of the interactions and not related to the presence of quenched disorder. An exponentially large number of metastable configurations is found, leading to a slow, landscape dominated lung time relaxation and a breakup of the system into a disordered inhomogeneous state. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Illinois, Dept Chem, Urbana, IL 61801 USA. RP Schmalian, J (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RI Schmalian, Joerg/H-2313-2011 NR 33 TC 147 Z9 147 U1 4 U2 21 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 24 PY 2000 VL 85 IS 4 BP 836 EP 839 DI 10.1103/PhysRevLett.85.836 PG 4 WC Physics, Multidisciplinary SC Physics GA 336PL UT WOS:000088311800039 ER PT J AU Gutsev, GL Rao, BK Jena, P Li, X Wang, LS AF Gutsev, GL Rao, BK Jena, P Li, X Wang, LS TI Experimental and theoretical study of the photoelectron spectra of MnOx-(x=1-3) clusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL CALCULATIONS; ELECTRONIC-STRUCTURE; GAS-PHASE; EXCITATION-ENERGIES; PERMANGANATE ION; MANGANESE OXIDE; NEGATIVE-IONS; MNO CLUSTERS; TRANSITION; SPECTROSCOPY AB We report a combined experimental and theoretical investigation of MnOx- and MnOx(x = 1-3) clusters. Theoretically, geometrical configurations of various isomers of the clusters were optimized and vertical detachment energies for the anions were evaluated. The ground state of MnO- was predicted to be (5)Sigma(+), followed by an excited state ((7)Sigma(+)) 0.14 eV higher in energy. The ground state of MnO2- is B-5(2), with a B-3(1) isomer 0.15 eV higher. MnO3- is predicted to be a singlet D-3h cluster. Vibrationally resolved photoelectron spectra of MnOx- were measured at several photon energies and under various experimental conditions, and were interpreted based on the theoretical results. The electron affinities of MnO, MnO2, and MnO3 were determined to be 1.375 (0.010), 2.06 (0.03), and 3.335 (0.010), respectively. Five excited states of MnO were observed and assigned using the theoretical results. The (7)Sigma(+) excited state of MnO- was found to be significantly populated and was distinguished from the ground state of the anion by temperature dependent studies. We observed two isomers for MnO2- and the detachment features from both isomers were assigned. Only one vibrationally resolved band was observed for MnO3-, which corresponds to transitions from the ground state of MnO3- to that of MnO3. The combined experimental and theoretical studies allow us to elucidate the complicated electronic and geometric structures of the various manganese oxide clusters and their anions. (C) 2000 American Institute of Physics. [S0021-9606(00)00428-1]. C1 Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. NR 74 TC 41 Z9 41 U1 3 U2 18 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 JUL 22 PY 2000 VL 113 IS 4 BP 1473 EP 1483 AR PII [S0021-9606(00)00428-1] DI 10.1063/1.481964 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 333RJ UT WOS:000088144000020 ER PT J AU Pack, RT Walker, RB Kendrick, BK AF Pack, RT Walker, RB Kendrick, BK TI Three-body collision contributions to recombination and collision-induced dissociation. II. Kinetics (vol 109, pg 6714, 1998) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction AB A programming error, which affects many of the numbers, tables, and figures of this paper, is corrected. It does not affect any of the conclusions of the work. (C) 2000 American Institute of Physics. [S0021-9606(00)01728-1]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Pack, RT (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-12,MS B268, Los Alamos, NM 87545 USA. NR 2 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 22 PY 2000 VL 113 IS 4 BP 1668 EP 1669 DI 10.1063/1.481957 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 333RJ UT WOS:000088144000044 ER PT J AU Brooks, PJ Wise, DS Berry, DA Kosmoski, JV Smerdon, MJ Somers, RL Mackie, H Spoonde, AY Ackerman, EJ Coleman, K Tarone, RE Robbins, JH AF Brooks, PJ Wise, DS Berry, DA Kosmoski, JV Smerdon, MJ Somers, RL Mackie, H Spoonde, AY Ackerman, EJ Coleman, K Tarone, RE Robbins, JH TI The oxidative DNA lesion 8,5 '-(S)-cyclo-2 '-deoxyadenosine is repaired by the nucleotide excision repair pathway and blocks gene expression in mammalian cells SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PIGMENTOSUM COMPLEMENTATION GROUP; RADICAL-INDUCED FORMATION; XERODERMA-PIGMENTOSUM; 6-4 PHOTOPRODUCTS; PYRIMIDINE DIMER; RNA-POLYMERASE; FREE-EXTRACTS; PLASMID DNA; BASE DAMAGE; GROUP-F AB Xeroderma pigmentosum (XP) patients with inherited defects in nucleotide excision repair (NER) are unable to excise from their DNA bulky photoproducts induced by UV radiation and therefore develop accelerated actinic damage, including cancer, on sun-exposed tissue. Some XP patients also develop a characteristic neurodegeneration believed to result from their inability to repair neuronal DNA damaged by endogenous metabolites since the harmful UV radiation in sunlight does not reach neurons. Free radicals, which are abundant in neurons, induce DNA lesions that, if unrepaired, might cause the XP neurodegeneration. Searching for such a lesion, we developed a synthesis for 8,5'-(S)-cyclo-2'-deoxyadenosine (cyclo-dA), a free radical-induced bulky lesion, and incorporated it into DNA to test its repair in mammalian cell extracts and living cells. Using extracts of normal and mutant Chinese hamster ovary (CHO) cells to test for NER and adult rat brain extracts to test for base excision repair, we found that cyclo-dA is re paired by NER and not by base excision repair. We measured host cell reactivation, which reflects a cell's capacity for NER, by transfecting CHO and XP cells with DNA constructs containing a single cyclo-dA or a cyclobutane thymine dimer at a specific site on the transcribed strand of a luciferase reporter gene. We found that, like the cyclobutane thymine dimer, cyclo-dA is a strong block to gene expression in CHO and human cells. Cyclo-dA was repaired extremely poorly in NER-deficient CHO cells and in cells from patients in XP complementation group A with neurodegeneration. Based on these findings, we propose that cyclo-dA is a candidate for an endogenous DNA lesion that might contribute to neurodegeneration in XP. C1 NIAAA, Neurogenet Lab, NIH, Bethesda, MD 20892 USA. Berry Associates Inc, Dexter, MI 48130 USA. Washington State Univ, Dept Biochem & Biophys, Pullman, WA 99164 USA. Glen Res Corp, Sterling, VA 20164 USA. Pacific NW Natl Lab, Dept Energy, Richland, WA 99352 USA. NCI, Dermatol Branch, NIH, Bethesda, MD 20892 USA. NCI, Biostat Branch, NIH, Bethesda, MD 20892 USA. RP Brooks, PJ (reprint author), NIAAA, Neurogenet Lab, NIH, 12420 Parklawn Dr, Bethesda, MD 20892 USA. FU NIEHS NIH HHS [ES02614, ESO4106] NR 49 TC 179 Z9 182 U1 0 U2 5 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 JUL 21 PY 2000 VL 275 IS 29 BP 22355 EP 22362 DI 10.1074/jbc.M002259200 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 337LY UT WOS:000088363800082 PM 10801836 ER PT J AU Torres, J Adams, PD Arkin, IT AF Torres, J Adams, PD Arkin, IT TI Use of a new label C-13=O-18 in the determination of a structural model of phospholamban in a lipid bilayer. Spatial restraints resolve the ambiguity arising from interpretations of mutagenesis data SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE phospholamban; ion channel; infrared spectroscopy; molecular dynamics ID SARCOPLASMIC-RETICULUM; ION-CHANNEL; TRANSMEMBRANE DOMAIN; SECONDARY STRUCTURE; PROTEIN-STRUCTURE; CARDIAC-FUNCTION; PHOSPHORYLATION; CA2+-ATPASE; EXPRESSION; FORMS AB A structural model of pentameric phospholamban (Plb) in a lipid bilayer has been derived using a combination of experimental data, obtained from ATR-FTIR site-directed dichroism, and the implementation of the resulting restraints during a molecular dynamics simulation. Plb (residues 24-52) has been synthesised incorporating a new label, 1-C-13=O-18, at residues 42 and 43. We have not only determined the tilt of the helices, 10(+/-6) degrees, but also the relative orientation of the transmembrane segments, with an omega angle of -32(+/-10) degrees for L42. This angle is taken as zero in the direction of the helix tilt. Plb is a simple test case where site-directed dichroism has been applied to resolve the indeterminacy arising from the mutagenesis data available. The results presented point specifically to a single structural model for Plb. (C) 2000 Academic Press. C1 Univ Cambridge, Dept Biochem, Cambridge Ctr Mol Recognit, Cambridge CB2 1GA, England. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Arkin, IT (reprint author), Univ Cambridge, Dept Biochem, Cambridge Ctr Mol Recognit, 80 Tennis Court Rd, Cambridge CB2 1GA, England. RI Adams, Paul/A-1977-2013; OI Adams, Paul/0000-0001-9333-8219; Torres, Jaume/0000-0002-1282-9727 NR 32 TC 83 Z9 83 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 21 PY 2000 VL 300 IS 4 BP 677 EP 685 DI 10.1006/jmbi.2000.3885 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 339ZV UT WOS:000088508500002 PM 10891262 ER PT J AU Connolly, KM Ilangovan, U Wojciak, JM Iwahara, M Clubb, RT AF Connolly, KM Ilangovan, U Wojciak, JM Iwahara, M Clubb, RT TI Major groove recognition by three-stranded beta-sheets: Affinity determinants and conserved structural features SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE protein-DNA complex; binding affinity; mutagenesis; fluorescence spectroscopy; three-stranded beta-sheet; Tn916 transposon ID DNA RECOGNITION; CONJUGATIVE TRANSPOSONS; CRYSTAL-STRUCTURE; OPERATOR RECOGNITION; ESCHERICHIA-COLI; ARC REPRESSOR; ZINC FINGERS; PROTEIN-DNA; COMPLEX; BINDING AB We present the results of a rational mutagenesis and binding-affinity study of the three-stranded beta-sheet-DNA interface in the complex formed by the amino-terminal DNA-binding domain of the Tn916 integrase protein and its cognate binding site. The relative importance of interfacial contacts present in its NMR-derived solution structure have been tested through mutagenesis, fluorescence anisotropy, and intrinsic quenching DNA-binding assays. We find that seven protein-DNA hydrogen bonds (two base-specific and five to phosphate groups) significantly contribute to the level of affinity. These interactions span the entire DNA-binding surface on the protein, but primarily originate from residues in only two strands of the sheet and loop L2. Interestingly, we show that highly populated, precisely defined intermolecular hydrogen bonds in the ensemble of conformers are invariably important for DNA-binding, implying that NMR-derived solution structures provide direct insight into the energetics of recognition. Unusual three-stranded beta-sheet-DNA interfaces have recently been discovered in three unrelated protein-DNA complexes. A comparative analysis of these structures reveals similar sheet positioning, the presence of two invariant interfacial contacts to the phosphodiester backbone, and two semi-conserved base-specific hydrogen bonds. Two of these conserved contacts significantly contribute to the affinity of the integrase-DNA complex, suggesting that the three-stranded beta-sheet DNA-binding motif exhibits conserved principles of recognition. (C) 2000 Academic Press. C1 Univ Calif Los Angeles, Dept Chem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, DOE Lab Struct Biol & Genet, Los Angeles, CA 90095 USA. RP Clubb, RT (reprint author), Univ Calif Los Angeles, Dept Chem, 405 Hilgard Ave, Los Angeles, CA 90095 USA. FU NIGMS NIH HHS [GM57487] NR 34 TC 15 Z9 15 U1 1 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 21 PY 2000 VL 300 IS 4 BP 841 EP 856 DI 10.1006/jmbi.2000.3888 PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 339ZV UT WOS:000088508500013 PM 10891272 ER PT J AU Garcia, M Clague, G AF Garcia, M Clague, G TI The 2D electric field above a planar sequence of independent strip electrodes SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article AB This paper describes an analytical solution for the electrostatic potential and electric field in dielectrophoretic (DEP) microfluidic devices. DEP devices are engineered to be DNA concentrators in automated, Row-through systems of sample preparation for biological assays. DEP devices deflect and trap particles suspended in liquid flows because macromolecular particles polarize in response to an electric field, and the coupling of this polarization with the field alters particle motions. The DEP effect is proportional to del(E.E). The electric field is produced by a sequence of independent strip electrodes and is two dimensional throughout the volume of the flow. As the potentials used in DEP devices are low-frequency sinusoids, the field of interest is the gradient of the squared root-mean-square (rms) of the electric field, del E-rms(2). An example of this field is shown. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Garcia, M (reprint author), Lawrence Livermore Natl Lab, POB 808,L-153, Livermore, CA 94551 USA. NR 9 TC 14 Z9 14 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD JUL 21 PY 2000 VL 33 IS 14 BP 1747 EP 1755 DI 10.1088/0022-3727/33/14/315 PG 9 WC Physics, Applied SC Physics GA 345CB UT WOS:000088796900016 ER PT J AU Akhmadaliev, S Albiol, F Amaral, P Ambrosini, G Amorim, A Anderson, K Andrieux, ML Aubert, B Auge, E Badaud, F Baisin, L Barreiro, F Battistoni, G Bazan, A Bazizi, K Bee, C Belorgey, J Belymam, A Benchekroun, D Berglund, S Berset, JC Blanchot, G Bogush, A Bohm, C Boldea, V Bonivento, W Borgeaud, P Borisov, O Bosman, M Bouhemaid, N Breton, D Brette, P Bromberg, C Budagov, J Burdin, S Caloba, L Camarena, F Camin, DV Canton, B Caprini, M Carvalho, J Casado, P Cases, R Castillo, MV Cavalli, D Cavalli-Sforza, M Cavasinni, V Chadelas, R Chalifour, M Chekhtman, L Chevalley, JL Chirikov-Zorin, I Chlachidze, G Chollet, JC Citterio, M Cleland, WE Clement, C Cobal, M Cogswell, F Colas, J Collot, J Cologna, S Constantinescu, S Costa, G Costanzo, D Coulon, JP Crouau, M Dargent, P Daudon, F David, M Davidek, T Dawson, J De, K Delagnes, E de la Taille, C Del Peso, J Del Prete, T de Saintignon, P Di Girolamo, B Dinkespiller, B Dita, S Djama, F Dodd, J Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Duval, PY Dzahini, D Efthymiopoulos, I Errede, D Errede, S Etienne, F Evans, H Eynard, G Farida, F Fassnacht, P Fedyakin, N De Troconiz, JF Ferrari, A Ferrari, A Ferrer, A Flaminio, V Fournier, D Fumagalli, G Gallas, E Garcia, G Gaspar, M Gianotti, F Gildemeister, O Glagolev, V Glebov, V Gomes, A Gonzalez, V De la Hoz, SG Gordeev, A Gordon, HA Grabsky, V Grauges, E Grenier, P Hakopian, H Haney, M Hebrard, C Henriques, A Henry-Couannier, F Hervas, L Higon, E Holmgren, S Hostachy, JY Hoummada, A Huet, M Huston, J Imbault, D Ivanyushenkov, Y Jacquier, Y Jezequel, S Johansson, E Jon-And, K Jones, R Juste, A Kakurin, S Karst, P Karyukhin, A Khokhlov, Y Khubua, J Klyukhin, V Kolachev, G Kolomoets, V Kopikov, S Kostrikov, M Kovtun, V Kozlov, V Krivkova, P Kukhtin, V Kulagin, M Kulchitsky, Y Kuzmin, M Labarga, L Laborie, G Lacour, D Lami, S Lapin, V Le Dortz, O Lefebvre, M Leflour, T Leitner, R Leltchouk, M Van Suu, AL Li, J Liapis, C Linossier, O Lissauer, D Lobkowicz, F Lokajicek, M Lomakin, Y Lomakina, O Amengual, JML Lottin, JP Lund-Jensen, B Lundquist, J Maio, A Makowiecki, D Malyukov, S Mandelli, L Mansoulie, B Mapelli, L Marin, CP Marrocchesi, P Marroquin, F Martin, L Martin, O Martin, P Maslennikov, A Massol, N Mazzanti, M Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mirea, A Mnatsakanian, E Monnier, E Montarou, G Mornacchi, G Mosidze, M Moynot, M Muanza, GS Nagy, E Nayman, P Nemecek, S Nessi, M Nicod, D Nicoleau, S Niculescu, M Noppe, JM Onofre, A Pallin, D Pantea, D Paoletti, R Park, IC Parrour, G Parsons, J Pascual, J Pereira, A Perini, L Perlas, JA Perrodo, P Petroff, P Pilcher, J Pinhao, J Plothow-Besch, H Poggioli, L Poirot, S Price, L Protopopov, Y Proudfoot, J Pukhov, O Puzo, P Radeka, V Rahm, D Reinmuth, G Renardy, JF Renzoni, G Rescia, S Resconi, S Richards, R Richer, JP Riu, I Roda, C Roldan, J Romance, J Romanov, V Romero, P Russakovich, N Sala, P Sanchis, E Sanders, H Santoni, C Santos, J Sauvage, D Sauvage, G Savoy-Navarro, A Sawyer, L Says, LP Schaffer, A Schwemling, P Schwindling, J Seguin-Moreau, N Seidl, W Seixas, JM Sellden, B Seman, M Semenov, A Senchishin, V Serin, L Shaldaev, E Shchelchkov, A Shochet, M Sidorov, V Silva, J Simaitis, V Simion, S Sissakian, A Soloviev, I Snopkov, R Soderqvist, J Solodkov, A Sonderegger, P Soustruznik, K Spano, F Spiwoks, R Stanek, R Starchenko, E Stavina, P Stephens, R Studenov, S Suk, M Surkov, A Sykora, I Taguet, JP Takai, H Tang, F Tardell, S Tas, P Teiger, J Teubert, F Thaler, J Thion, J Tikhonov, Y Tisserand, V Tisserant, S Tokar, S Topilin, N Trka, Z Turcotte, M Valkar, S Varanda, MJ Vartapetian, A Vazeille, F Vichou, I Vincent, P Vinogradov, V Vorozhtsov, S Vuillemin, V Walter, C White, A Wielers, M Wingerter-Seez, I Wolters, H Yamdagni, N Yarygin, G Yosef, C Zaitsev, A Zitoun, R Zolnierowski, YP AF Akhmadaliev, S Albiol, F Amaral, P Ambrosini, G Amorim, A Anderson, K Andrieux, ML Aubert, B Auge, E Badaud, F Baisin, L Barreiro, F Battistoni, G Bazan, A Bazizi, K Bee, C Belorgey, J Belymam, A Benchekroun, D Berglund, S Berset, JC Blanchot, G Bogush, A Bohm, C Boldea, V Bonivento, W Borgeaud, P Borisov, O Bosman, M Bouhemaid, N Breton, D Brette, P Bromberg, C Budagov, J Burdin, S Caloba, L Camarena, F Camin, DV Canton, B Caprini, M Carvalho, J Casado, P Cases, R Castillo, MV Cavalli, D Cavalli-Sforza, M Cavasinni, V Chadelas, R Chalifour, M Chekhtman, L Chevalley, JL Chirikov-Zorin, I Chlachidze, G Chollet, JC Citterio, M Cleland, WE Clement, C Cobal, M Cogswell, F Colas, J Collot, J Cologna, S Constantinescu, S Costa, G Costanzo, D Coulon, JP Crouau, M Dargent, P Daudon, F David, M Davidek, T Dawson, J De, K Delagnes, E de la Taille, C Del Peso, J Del Prete, T de Saintignon, P Di Girolamo, B Dinkespiller, B Dita, S Djama, F Dodd, J Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Duval, PY Dzahini, D Efthymiopoulos, I Errede, D Errede, S Etienne, F Evans, H Eynard, G Farida, F Fassnacht, P Fedyakin, N De Troconiz, JF Ferrari, A Ferrari, A Ferrer, A Flaminio, V Fournier, D Fumagalli, G Gallas, E Garcia, G Gaspar, M Gianotti, F Gildemeister, O Glagolev, V Glebov, V Gomes, A Gonzalez, V De la Hoz, SG Gordeev, A Gordon, HA Grabsky, V Grauges, E Grenier, P Hakopian, H Haney, M Hebrard, C Henriques, A Henry-Couannier, F Hervas, L Higon, E Holmgren, S Hostachy, JY Hoummada, A Huet, M Huston, J Imbault, D Ivanyushenkov, Y Jacquier, Y Jezequel, S Johansson, E Jon-And, K Jones, R Juste, A Kakurin, S Karst, P Karyukhin, A Khokhlov, Y Khubua, J Klyukhin, V Kolachev, G Kolomoets, V Kopikov, S Kostrikov, M Kovtun, V Kozlov, V Krivkova, P Kukhtin, V Kulagin, M Kulchitsky, Y Kuzmin, M Labarga, L Laborie, G Lacour, D Lami, S Lapin, V Le Dortz, O Lefebvre, M Leflour, T Leitner, R Leltchouk, M Van Suu, AL Li, J Liapis, C Linossier, O Lissauer, D Lobkowicz, F Lokajicek, M Lomakin, Y Lomakina, O Amengual, JML Lottin, JP Lund-Jensen, B Lundquist, J Maio, A Makowiecki, D Malyukov, S Mandelli, L Mansoulie, B Mapelli, L Marin, CP Marrocchesi, P Marroquin, F Martin, L Martin, O Martin, P Maslennikov, A Massol, N Mazzanti, M Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mirea, A Mnatsakanian, E Monnier, E Montarou, G Mornacchi, G Mosidze, M Moynot, M Muanza, GS Nagy, E Nayman, P Nemecek, S Nessi, M Nicod, D Nicoleau, S Niculescu, M Noppe, JM Onofre, A Pallin, D Pantea, D Paoletti, R Park, IC Parrour, G Parsons, J Pascual, J Pereira, A Perini, L Perlas, JA Perrodo, P Petroff, P Pilcher, J Pinhao, J Plothow-Besch, H Poggioli, L Poirot, S Price, L Protopopov, Y Proudfoot, J Pukhov, O Puzo, P Radeka, V Rahm, D Reinmuth, G Renardy, JF Renzoni, G Rescia, S Resconi, S Richards, R Richer, JP Riu, I Roda, C Roldan, J Romance, J Romanov, V Romero, P Russakovich, N Sala, P Sanchis, E Sanders, H Santoni, C Santos, J Sauvage, D Sauvage, G Savoy-Navarro, A Sawyer, L Says, LP Schaffer, A Schwemling, P Schwindling, J Seguin-Moreau, N Seidl, W Seixas, JM Sellden, B Seman, M Semenov, A Senchishin, V Serin, L Shaldaev, E Shchelchkov, A Shochet, M Sidorov, V Silva, J Simaitis, V Simion, S Sissakian, A Soloviev, I Snopkov, R Soderqvist, J Solodkov, A Sonderegger, P Soustruznik, K Spano, F Spiwoks, R Stanek, R Starchenko, E Stavina, P Stephens, R Studenov, S Suk, M Surkov, A Sykora, I Taguet, JP Takai, H Tang, F Tardell, S Tas, P Teiger, J Teubert, F Thaler, J Thion, J Tikhonov, Y Tisserand, V Tisserant, S Tokar, S Topilin, N Trka, Z Turcotte, M Valkar, S Varanda, MJ Vartapetian, A Vazeille, F Vichou, I Vincent, P Vinogradov, V Vorozhtsov, S Vuillemin, V Walter, C White, A Wielers, M Wingerter-Seez, I Wolters, H Yamdagni, N Yarygin, G Yosef, C Zaitsev, A Zitoun, R Zolnierowski, YP CA ATLAS Collaboration Calorimetry Da TI Results from a new combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PERFORMANCE AB A new combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 10 to 300 GeV at an incident angle a of about 12 degrees is well described by the expression sigma/E = ((41.9 +/- 1.6)%/root E + (1.8 +/- 0.1)%)circle plus(1.8 +/- 0.1)/E, where E is in GeV. The response to electrons and muons was evaluated. Shower profiles, shower leakage and the angular resolution of hadronic showers were also studied. Results are compared with those from the previous beam test. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CERN, Div PPE, CH-1211 Geneva 23, Switzerland. Univ Lisbon, FCUL, P-1699 Lisbon, Portugal. LIP Lisbon, Lisbon, Portugal. IFIC, Valencia, Spain. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Univ Chicago, Chicago, IL 60637 USA. Univ Grenoble 1, ISN, CNRS, IN2P3, Grenoble, France. LAPP, Annecy, France. LAL, Orsay, France. Univ Clermont Ferrand, CNRS IN2P3, LPC Clermont Ferrand, Clermont Ferrand, France. Univ Autonoma Madrid, E-28049 Madrid, Spain. Univ Milan, Milan, Italy. Ist Nazl Fis Nucl, Milan, Italy. Univ Rochester, Dept Phys & Astron, New York, NY USA. CPP, Marseille, France. Ctr Etud Saclay, CEA, DAPNIA, DSM,SPP, Gif Sur Yvette, France. Univ Hassan II, Fac Sci Ain Chock, Casablanca, Morocco. Stockholm Univ, Stockholm, Sweden. Horia Hulubei Natl Inst Phys & Nucl Engn, IFIN HH, Bucharest, Romania. Univ Autonoma Barcelona, Inst Fis Altes Energies, Barcelona, Spain. Natl Acad Sci, Minsk, Byelarus. Joint Inst Nucl Res Dubna, Dubna, Russia. Michigan State Univ, E Lansing, MI 48824 USA. Univ Pisa, Pisa, Italy. Ist Nazl Fis Nucl, Pisa, Italy. UFRJ, COPPE, EE, Rio De Janeiro, Brazil. Univ Paris 04, LPNHE, F-75230 Paris 05, France. Univ Paris 07, LPNHE, F-75221 Paris 05, France. Univ Coimbra, FCTUC, P-3000 Coimbra, Portugal. LIP Lisbon, Lisbon, Portugal. Brookhaven Natl Lab, Upton, NY USA. Univ Pittsburgh, Pittsburgh, PA USA. Royal Inst Technol, Stockholm, Sweden. Univ Illinois, Urbana, IL 61801 USA. Charles Univ, Prague, Czech Republic. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Texas, Arlington, TX 76019 USA. Columbia Univ, Nevis Labs, Irvington, NY USA. Univ Pavia, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Yerevan Phys Inst, Yerevan, Armenia. Inst High Energy Phys, Protvino, Russia. Univ Victoria, Victoria, BC V8W 2Y2, Canada. Acad Sci Czech Republ, Prague, Czech Republic. LIP Lisbon, Lisbon, Portugal. PNPI, St Petersburg, Russia. Comenius Univ, Bratislava, Slovakia. RP Cobal, M (reprint author), CERN, Div PPE, CH-1211 Geneva 23, Switzerland. RI Rescia, Sergio/D-8604-2011; David, Mario/C-4664-2012; Takai, Helio/C-3301-2012; Klyukhin, Vyacheslav/D-6850-2012; sala, paola/E-2868-2013; Wolters, Helmut/M-4154-2013; De, Kaushik/N-1953-2013; Nemecek, Stanislav/G-5931-2014; Bosman, Martine/J-9917-2014; Camarena, Francisco/L-9349-2014; Cavalli-Sforza, Matteo/H-7102-2015; Ferrer, Antonio/H-2942-2015; Marrocchesi, Pier Simone/N-9068-2015; Carvalho, Joao/M-4060-2013; Gonzalez de la Hoz, Santiago/E-2494-2016; Pacheco Pages, Andres/C-5353-2011; delagnes, eric/G-8782-2011; Gonzalez Millan, Vicente/J-3023-2012; SANCHIS, ENRIQUE/J-7348-2016; Solodkov, Alexander/B-8623-2017; Zaitsev, Alexandre/B-8989-2017; Karyukhin, Andrey/J-3904-2014; OI Rescia, Sergio/0000-0003-2411-8903; Takai, Helio/0000-0001-9253-8307; Klyukhin, Vyacheslav/0000-0002-8577-6531; sala, paola/0000-0001-9859-5564; Wolters, Helmut/0000-0002-9588-1773; De, Kaushik/0000-0002-5647-4489; Bosman, Martine/0000-0002-7290-643X; Camarena, Francisco/0000-0002-6713-1414; Ferrer, Antonio/0000-0003-0532-711X; Marrocchesi, Pier Simone/0000-0003-1966-140X; Carvalho, Joao/0000-0002-3015-7821; Gonzalez de la Hoz, Santiago/0000-0001-5304-5390; Pacheco Pages, Andres/0000-0001-8210-1734; Gonzalez Millan, Vicente/0000-0001-6014-2586; SANCHIS, ENRIQUE/0000-0002-9689-9131; Solodkov, Alexander/0000-0002-2737-8674; Zaitsev, Alexandre/0000-0002-4961-8368; Gomes, Agostinho/0000-0002-5940-9893; Karyukhin, Andrey/0000-0001-9087-4315; Maio, Amelia/0000-0001-9099-0009; Amorim, Antonio/0000-0003-0638-2321; Colomer, Kiko Albiol/0000-0002-3824-2246 NR 22 TC 14 Z9 14 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 21 PY 2000 VL 449 IS 3 BP 461 EP 477 DI 10.1016/S0168-9002(00)00153-4 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RV UT WOS:000088317500003 ER PT J AU Atkins, R Benbow, W Berley, D Chen, ML Coyne, DG Delay, RS Dingus, BL Dorfan, DE Ellsworth, RW Espinoza, C Evans, D Falcone, A Fleysher, L Fleysher, R Gisler, G Goodman, JA Haines, TJ Hoffman, CM Hugenberger, S Kelley, LA Klein, S Leonor, I Macri, J McConnell, M McCullough, JF McEnery, JE Miller, RS Mincer, AI Morales, MF Murray, MM Nemethy, P Paliaga, G Ryan, JM Schneider, M Shen, B Shoup, A Sinnis, G Smith, AJ Sullivan, GW Thompson, TN Tumer, OT Wang, K Wascko, MO Westerhoff, S Williams, DA Yang, T Yodh, GB AF Atkins, R Benbow, W Berley, D Chen, ML Coyne, DG Delay, RS Dingus, BL Dorfan, DE Ellsworth, RW Espinoza, C Evans, D Falcone, A Fleysher, L Fleysher, R Gisler, G Goodman, JA Haines, TJ Hoffman, CM Hugenberger, S Kelley, LA Klein, S Leonor, I Macri, J McConnell, M McCullough, JF McEnery, JE Miller, RS Mincer, AI Morales, MF Murray, MM Nemethy, P Paliaga, G Ryan, JM Schneider, M Shen, B Shoup, A Sinnis, G Smith, AJ Sullivan, GW Thompson, TN Tumer, OT Wang, K Wascko, MO Westerhoff, S Williams, DA Yang, T Yodh, GB CA Milagro Collaboration TI Milagrito, a TeV air-shower array SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE gamma-ray astronomy; extensive air-shower detectors; cosmic-ray detectors ID GAMMA-RAY ASTRONOMY; COSMIC-RAYS; MARKARIAN-501; SPECTRUM; ENERGIES AB Milagrito, a large, covered water-Cherenkov detector, was the world's first air-shower-particle detector sensitive to cosmic gamma rays below 1 TeV. It served as a prototype for the Milagro detector and operated from February 1997 to May 1998. This paper gives a description of Milagrito, a summary of the operating experience, and early results that demonstrate the capabilities of this technique. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. Univ Utah, Salt Lake City, UT 84112 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Calif Irvine, Irvine, CA 92717 USA. George Mason Univ, Fairfax, VA 22030 USA. Univ New Hampshire, Durham, NH 03824 USA. NYU, New York, NY 10003 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Natl Sci Fdn, Arlington, VA 22230 USA. RP Los Alamos Natl Lab, Div Phys, Mail Stop H803,POB 1663, Los Alamos, NM 87545 USA. EM cy@lanl.gov OI Dingus, Brenda/0000-0001-8451-7450 NR 36 TC 53 Z9 53 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 JUL 21 PY 2000 VL 449 IS 3 BP 478 EP 499 DI 10.1016/S0168-9002(00)00146-7 PG 22 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RV UT WOS:000088317500004 ER PT J AU Vernin, P Le Bars, J Fonvieille, H Quemener, G LeRose, JJ Hogan, J Vlahovic, B Billan, J AF Vernin, P Le Bars, J Fonvieille, H Quemener, G LeRose, JJ Hogan, J Vlahovic, B Billan, J TI Field mapping of the Hall A high-resolution spectrometers of the Thomas Jefferson National Accelerator Facility (Jefferson Lab) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE field mapping; superconducting magnets; dipole; quadrupoles; rotating coils; Hall probes ID Q1 QUADRUPOLES AB This paper reports on the magnetic field mapping performed on the HRS spectrometers of Hall A, which are of QQDQ type. The dipoles were measured with a set of Hall probes in the symmetry mid-plane. The quadrupoles were measured inside their whole volume by a set of axially segmented rotating coils. High accuracy has been reached in both cases, Dipoles and quadrupoles were measured for a set of excitation currents covering the operating momentum range of the HRS: 0.5-4 GeV/c. The main results on field determination are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Clermont Ferrand 2, Phys Corpusculaire Lab, IN2P3, CNRS, F-63170 Clermont Ferrand, France. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. N Carolina Cent Univ, Durham, NC 27707 USA. CERN, AT Div, Geneva 23, Switzerland. CEA Saclay, DAPNIA, SPHN, F-91191 Gif Sur Yvette, France. RP Fonvieille, H (reprint author), Univ Clermont Ferrand 2, Phys Corpusculaire Lab, IN2P3, CNRS, F-63170 Clermont Ferrand, France. OI Quemener, Gilles/0000-0001-6703-6655 NR 20 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 21 PY 2000 VL 449 IS 3 BP 505 EP 527 DI 10.1016/S0168-9002(00)00148-0 PG 23 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RV UT WOS:000088317500006 ER PT J AU Sessler, AM AF Sessler, AM TI Way out there in the blue - Reagan, Star Wars and the end of the Cold War SO SCIENCE LA English DT Book Review C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Sessler, AM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,Mailstop 71-259, Berkeley, CA 94720 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUL 21 PY 2000 VL 289 IS 5478 BP 397 EP 397 DI 10.1126/science.289.5478.397 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 336ME UT WOS:000088305500023 ER PT J AU Genin, FY Feit, MD Kozlowski, MR Rubenchik, AM Salleo, A Yoshiyama, J AF Genin, FY Feit, MD Kozlowski, MR Rubenchik, AM Salleo, A Yoshiyama, J TI Rear-surface laser damage on 355-nm silica optics owing to Fresnel diffraction on front-surface contamination particles SO APPLIED OPTICS LA English DT Article ID FUSED-SILICA; SINGLE-CRYSTALS; GAUSSIAN-BEAM; AMPLIFIER; THRESHOLD; IMAGES; LIGHT; KDP; NM; OBSCURATIONS AB Light intensity modulations caused by opaque obstacles (e.g., dust) on silica lenses in high-power lasers often enhance the potential for laser-induced damage. To study this effect, particles (10-250 mu m) with various shapes were sputter deposited on the input surface and irradiated with a 3-ns laser beam at 355 nm. Although a clean silica surface damages at fluences above 15 J/cm(2) a surface contaminated with particles can damage below 11.5 J/cm(2). A pattern that conforms to the shape of the input surface particle is printed on the output surface. Repetitive illumination resulted in catastrophic drilling of the optic. The damage pattern correlated with an interference image of the particle before irradiation. The image shows that the incident beam undergoes phase land amplitude modulations after it passes around the particle. We modeled the experiments by calculating the light intensity distribution behind an obscuration by use of Fresnel diffraction theory. The comparison between calculated light intensity distribution and the output surface damage pattern showed good agreement. The model was then used to predict the increased damage vulnerability that results from intensity modulations as a function of particle size, shape, and lens thickness. The predictions provide the basis for optics cleanliness specifications on the National Ignition Facility to reduce the likelihood of optical damage. (C) 2000 Optical Society of America OCIS code: 140.3380. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM fgenin@llnl.gov RI Feit, Michael/A-4480-2009 NR 41 TC 48 Z9 56 U1 6 U2 24 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 JUL 20 PY 2000 VL 39 IS 21 BP 3654 EP 3663 DI 10.1364/AO.39.003654 PG 10 WC Optics SC Optics GA 337FC UT WOS:000088345900014 PM 18349939 ER PT J AU Bayramian, AJ Bibeau, C Beach, RJ Marshall, CD Payne, SA AF Bayramian, AJ Bibeau, C Beach, RJ Marshall, CD Payne, SA TI Consideration of stimulated Raman scattering in Yb : Sr-5(PO4)(3)F laser amplifiers SO APPLIED OPTICS LA English DT Article ID S-FAP LASER; PERFORMANCE; ENERGY; GAIN AB The stimulated Raman-scattering (SRS) gain coefficient has been measured quantitatively for the first time to our knowledge in Yb:Sr-5(PO4)(3)F to be 1.23 +/- 0.12 cm/GW at 1053 nm. These data, along with surface and bulk losses, feedback that is due to surface reflections, gain saturation, and bandwidth, have been applied to a quantitative model that predicts the effects of SRS within a laser amplifier system where the laser gain media show SRS gain. Limitations and impact to the laser amplifier performance are discussed, along with possible techniques to reduce SRS loss. (C) 2000 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, 7000 East Ave,L-482, Livermore, CA 94551 USA. EM bayramian1@llnl.gov NR 21 TC 8 Z9 8 U1 1 U2 3 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 JUL 20 PY 2000 VL 39 IS 21 BP 3746 EP 3753 DI 10.1364/AO.39.003746 PG 8 WC Optics SC Optics GA 337FC UT WOS:000088345900025 PM 18349950 ER PT J AU Becker, RH White, RL Gregg, MD Brotherton, MS Laurent-Muehleisen, SA Arav, N AF Becker, RH White, RL Gregg, MD Brotherton, MS Laurent-Muehleisen, SA Arav, N TI Properties of radio-selected broad absorption line quasars from the first Bright Quasar Survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE quasars : absorption lines; quasars : general; radio continuum : general; surveys ID OPTICAL-PROPERTIES; STELLAR OBJECTS; QUIET QUASARS; SKY SURVEY; QSO; LOUD; POLARIZATION; COMPANION; SPECTRUM AB In a spectroscopic follow-up to the VLA FIRST survey, the FIRST Bright Quasar Survey (FBQS) has found 29 radio-selected broad absorption line (BAL) quasars. This sample provides the first opportunity to study the properties of radio-selected BAL quasars. Contrary to most previous studies, we establish that a significant population of radio-loud BAL quasars exists. Radio-selected BAL quasars display compact radio morphologies and possess both steep and flat radio spectra. Quasars with low-ionization BALs have a color distribution redder than that of the FBQS sample as a whole. The frequency of BAL quasars in the FBQS is significantly greater, perhaps by as much as a factor of 2, than that inferred from optically selected samples. The frequency of BAL quasars appears to have a complex dependence on radio loudness. The properties of this sample appear to be inconsistent with simple unified models in which BAL quasars constitute a subset of quasars seen edge-on. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Becker, RH (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. NR 42 TC 198 Z9 198 U1 0 U2 1 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 JUL 20 PY 2000 VL 538 IS 1 BP 72 EP 82 DI 10.1086/309099 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343MK UT WOS:000088706000007 ER PT J AU Knupp, PM AF Knupp, PM TI Achieving finite element mesh quality via optimization of the Jacobian matrix norm and associated quantities. Part II - A framework for volume mesh optimization and the condition number of the Jacobian matrix SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE unstructured grid generation; finite element mesh; mesh optimization; smoothing; condition number ID GENERATION AB Three-dimensional unstructured tetrahedral and hexahedral finite element mesh optimization is studied from a theoretical perspective and by computer experiments to determine what objective functions are most effective in attaining valid, high-quality meshes. The approach uses matrices and matrix norms to extend the work in Part I to build suitable 3D objective functions. Because certain matrix norm identities which hold for 2x2 matrices do not hold for 3x3 matrices, significant differences arise between surface and volume mesh optimization objective functions. It is shown, for example, that the equality in two dimensions of the smoothness and condition number of the Jacobian matrix objective functions does not extend to three dimensions and further, that the equality of the Oddy and condition number of the metric tensor objective functions in two dimensions also fails to extend to three dimensions. Matrix norm identities are used to systematically construct dimensionally homogeneous groups of objective functions. The concept of an ideal minimizing matrix is introduced for both hexahedral and tetrahedral elements. Non-dimensional objective functions having barriers are emphasized as the most logical choice for mesh optimization. The performance of a number of objective functions in improving mesh quality was assessed on a suite of realistic test problems, focusing particularly on all-hexahedral 'whisker-weaved' meshes. Performance is investigated on both structured and unstructured meshes and on both hexahedral and tetrahedral meshes. Although :several objective functions are competitive, the condition number objective function is particularly attractive. The objective functions are closely related to mesh quality measures. To illustrate, it is shown that the condition number metric can be viewed as a new tetrahedral element quality measure. Published in 2000 by John Wiley & Sons, Ltd. C1 Sandia Natl Labs, Parallel Comp Sci Dept, Albuquerque, NM 87185 USA. RP Knupp, PM (reprint author), Sandia Natl Labs, Parallel Comp Sci Dept, M-S 0847,POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 123 Z9 126 U1 2 U2 8 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD JUL 20 PY 2000 VL 48 IS 8 BP 1165 EP 1185 DI 10.1002/(SICI)1097-0207(20000720)48:8<1165::AID-NME940>3.0.CO;2-Y PG 21 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 329KG UT WOS:000087905700004 ER PT J AU Chorin, AJ Kupferman, R Levy, D AF Chorin, AJ Kupferman, R Levy, D TI Optimal prediction for Hamiltonian partial differential equations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE optimal prediction; underresolution; perturbation methods; regression; nonlinear Schrodinger; pseudo-spectral methods ID COMPUTATION AB Optimal prediction methods compensate for a lack of resolution in the numerical solution of time-dependent differential equations through the use of prior statistical information. We present a new derivation of the basic methodology, show that field-theoretical perturbation theory provides a useful device for dealing with quasi-linear problems, and provide a nonlinear example that illuminates the difference between a pseudo-spectral method and an optimal prediction method with Fourier kernels. Along the way, we explain the differences and similarities between optimal prediction, the representer method in data assimilation, and duality methods for finding weak solutions. We also discuss the conditions under which a simple implementation of the optimal prediction method can be expected to perform well. (C) 2000 Academic Press. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Hebrew Univ Jerusalem, Inst Math, IL-91904 Jerusalem, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Chorin, AJ (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. NR 26 TC 14 Z9 14 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 JUL 20 PY 2000 VL 162 IS 1 BP 267 EP 297 DI 10.1006/jcph.2000.6536 PG 31 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 334GD UT WOS:000088177900011 ER PT J AU Gosztola, D Niemczyk, MP Svec, W Lukas, AS Wasielewski, MR AF Gosztola, D Niemczyk, MP Svec, W Lukas, AS Wasielewski, MR TI Excited doublet states of electrochemically generated aromatic imide and diimide radical anions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; NEMATIC LIQUID-CRYSTALS; SPECTROSCOPIC PROPERTIES; PARAMAGNETIC-RESONANCE; FLUORESCENT DYES; LASER EXCITATION; ION-PAIR; MOLECULES; PHOTOCHEMISTRY; PHOTOSYNTHESIS AB The radical anions of aromatic diimides have been implicated recently ill a wide variety of photochemical electron transfer reactions. Photoexcitation of these radical anions produces powerfully reducing species. Yet, the properties of the pi* excited doublet states of these organic radical anions remain obscure. The radical anions of three aromatic imides with increasingly larger pi systems, N-(2,5-di-tert-butylphenyl)phthalimide, 2, N-(2,5-di-tert-butylphenyl)-1,8-naphthalimide, 2, and N-(2,5-di-tert-butylphenyl)perylene-3,4-dicarboximide, 3, as well as the three corresponding aromatic diimides, N,N'-bis(3,5-di-tert-butylphenyl)pyromellitimide, 4a, N,N'-bis(2,5-di-tert-butylphenyl)-naphthalene-1,8:4,5-tetracarboxydiimide, 5a, and N,N'-bis(2,5-di-tert-butylphenyl)perylene-3,4: 9,10-tetracarboxydiimide, 6, were produced by electrochemical reduction of the neutral molecules in an optically transparent thin layer electrochemical cell. The radical anions of these imides and diimides all exhibit intense visible and weaker near-IR absorption bands corresponding to their D-0 --> D-n transitions. Excited states of the radical anions were generated by subpicosecond excitation into these absorption bands. Excitation of 1(.-) and 2(.-) resulted in decomposition of these radical anions, whereas excitation of 3(.-)-6(.-) yielded transient spectra of their D-1 --> D-n transitions and the lifetimes of D-1. The lifetimes of the D-1 excited states of the radical anions of 3(.-)-6(.-) are all less than 600 ps and increase as the Do-DI energy gap increases. These results impose design constraints on the use of these excited radical anions as electron donors in electron-transfer systems targeted toward molecular electronics and solar energy conversion. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Gosztola, D (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wasielew@chem.nwu.edu RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 53 TC 292 Z9 293 U1 15 U2 130 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 JUL 20 PY 2000 VL 104 IS 28 BP 6545 EP 6551 DI 10.1021/jp000706f PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 337NM UT WOS:000088368200004 ER PT J AU Bansal, A Turner, JA AF Bansal, A Turner, JA TI Suppression of band edge migration at the p-GaInP2/H2O interface under illumination via catalysis SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SEMICONDUCTOR LIQUID JUNCTION; IMPEDANCE SPECTROSCOPY; AQUEOUS-ELECTROLYTES; GAAS ELECTRODES; PHOTO-CATHODES; SOLAR-CELLS; HYDROGEN; WATER; SURFACE; METAL AB The band edges of p-GaInP2 are observed to migrate toward negative potentials during current flow under illumination in solutions with pH ranging from 1 to 14.5. The migration is not caused by a change in the pH of the semiconductor microenvironment but is a result of accumulation of photogenerated electrons at the p-GaInP2/water interface due to poor interfacial kinetics. This less than optimal interfacial charge-transfer rate can be catalyzed by treating the surface with transition-metal ions (e.g., Ru-III, Rh-III, Co-III, Os-III) which results in a suppression of band edge migration. As compared to an unmodified p-GaInP2 surface, the metal-ion treatment does not induce any appreciable band edge shift in the dark but effectively suppresses the band edge migration under illumination. Rum and RhIII are found to act as better hydrogen-evolution catalysts than electrodeposited Pt. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Turner, JA (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Schaff, William/B-5839-2009 NR 41 TC 17 Z9 17 U1 1 U2 13 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 JUL 20 PY 2000 VL 104 IS 28 BP 6591 EP 6598 DI 10.1021/jp000387s PG 8 WC Chemistry, Physical SC Chemistry GA 337NP UT WOS:000088368400012 ER PT J AU He, ZF Gosztola, D Deng, Y Gao, GQ Wasielewski, MR Kispert, LD AF He, ZF Gosztola, D Deng, Y Gao, GQ Wasielewski, MR Kispert, LD TI Effect of terminal groups, polyene chain length, and solvent on the first excited singlet states of carotenoids SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENERGY-GAP LAW; TRANS-BETA-CAROTENE; TEMPERATURE-DEPENDENCE; LIFETIME; PHOTOSYNTHESIS; FLUORESCENCE; ABSORPTION; DYNAMICS; SHIFTS AB The effect of terminal groups, polyene chain length, and solvent on the first excited singlet states (SI) of carotenoids was studied by steady-state and transient optical absorption spectroscopy, and AM1 semiempirical molecular orbital calculations. The carotenoids studied were ethyl 8'-apo-beta-caroten-8'-oate (I), ethyl 6'-apo-beta-caroten-6'-oate (II), ethyl 4'-apa-beta-caroten-4'-oate (III), s'-apo-beta-caroten-8'-nitrile (IV), 6'-apo-beta-caroten-6'-nitrile (V), 4'-apo-beta-caroten-4'-nitrile (VI), 8'-apo-beta-caroten-8'-al (VII), and 6'-apo-beta-caroten-6'-al (VIII). Solvents were 3-methylpentane (3-MP) and MeCN. The effect of solvent on the SI absorption maxima is similar to that on the ground state (So) absorption maxima, which suggests that both effects stem from the same type of interaction, i.e., the dispersive interaction between carotenoids and solvents. Carotenoids with terminal CHO groups have S-1 absorption maxima at longer wavelenths than those with terminal CN or CO2-Et groups. The S1 absorption maxima are red-shifted with increasing polyene chain length. In the nonpolar solvent 3-MP, the S1 lifetimes of carotenoids depend mainly on the polyene chain length. With a one C=C bond increase, the SI lifetime decreases by a factor of ca. 2 (ca. 24 ps for I, IV, and VII; 12 ps for II, V, and VIII; and 7 ps for III and VI). Terminal groups have little effect on the Si lifetimes in 3-MP. However, in the polar solvent MeCN, carotenoids with terminal CHO groups have decreased S1 lifetimes (ca. 8 ps for VII and 6 ps for VIII), while carotenoids with terminal CN and CO2Et groups have essentially unchanged Si lifetimes. This observation, along with the data of beta-carotene and 7'-apo-7',7'-dicyano-beta-carotene, suggests that polar solvents could decrease the S-1 lifetimes of carotenoids, when, and only when, there is considerable charge transfer character in their excited states. C1 Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Kispert, LD (reprint author), Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 22 TC 28 Z9 29 U1 0 U2 3 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 JUL 20 PY 2000 VL 104 IS 28 BP 6668 EP 6673 DI 10.1021/jp0008344 PG 6 WC Chemistry, Physical SC Chemistry GA 337NP UT WOS:000088368400021 ER PT J AU Greulich, KM Kreja, L Heinze, B Rhein, AP Weier, HUG Bruckner, M Fuchs, P Molls, M AF Greulich, KM Kreja, L Heinze, B Rhein, AP Weier, HUG Bruckner, M Fuchs, P Molls, M TI Rapid detection of radiation-induced chromosomal aberrations in lymphocytes and hematopoietic progenitor cells by mFISH SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE radiation; chromosome aberrations; hematopoietic system; stem cells; mFISH; Chernobyl accident ID LINE TPC-1; STEM-CELLS; HYBRIDIZATION; EXPOSURE; FISH; TRANSLOCATION; FREQUENCY; DAMAGE AB Structural chromosome aberrations (SCAs) are sensitive indicators of a preceding exposure of the hematopoietic system to ionizing radiation. Cytogenetic investigations have therefore become routine tools for an assessment of absorbed radiation doses and their biological effects after occupational exposure or radiation accidents. Due to its speed and ease of use, fluorescence in situ hybridization (FISH) with whole chromosome painting (WCP) probes has become a method of choice to visualize SCAs. Until recently, this technique was limited to a rather small number of chromosomes, which could be tested simultaneously. As a result, only a fraction of the structural aberrations present in a sample could be detected and the overall dose effect had to be calculated by extrapolation. The recent introduction of two genome-wide screening techniques in tumor research, i.e., Spectral Karyotyping (SKY) and multicolor FISH (mFISH) now allows the detection of translocations involving any two non-homologous chromosomes. The present study was prompted by our desire to bring the power of mFISH to bear for the rapid identification of radiation-induced SCAs. We chose two model systems to investigate the utility of mFISH: lymphocytes that were exposed in vitro to 3 Gy photons and single hematopoietic progenitor cell colonies isolated from a Chernobyl victim 9 years after in vivo exposure to 5.4 Sv. In lymphocytes, we found up to 15 different chromosomes involved in rearrangements indicating complex radiation effects. Stable aberrations detected in hematopoietic cell colonies, on the other hand, showed involvement of up to three different chromosomes. These results demonstrated that mFISH is a rapid and powerful approach to detect and characterize radiation-induced SCAs in the hemopoietic system. The application of mFISH is expected to result in a more detailed and, thus, more informative picture of radiation effects. Eventually, this technique will allow researchers to rapidly delineate chromosomal breakpoints and facilitate the identification of the genes involved in radiation tumorigenesis. (C) 2000 published by Elsevier Science B.V. C1 Tech Univ Munich, Dept Radiat Oncol, D-81675 Munich, Germany. Univ Ulm, Inst Occupat Social & Environm Med, Ulm, Germany. Univ Ulm, Dept Med Genet, Ulm, Germany. E O Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA USA. Vysis GmbH, Bergisch Gladbach, Germany. RP Greulich, KM (reprint author), Tech Univ Munich, Dept Radiat Oncol, Ismaninger Str 22, D-81675 Munich, Germany. NR 28 TC 47 Z9 49 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD JUL 20 PY 2000 VL 452 IS 1 BP 73 EP 81 DI 10.1016/S0027-5107(00)00057-9 PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 344GA UT WOS:000088749800010 PM 10894893 ER PT J AU Barrette, J Bellwied, R Bennett, S Bersch, R Braun-Munzinger, P Chang, WC Cleland, WE Clemen, M Cole, J Cormier, TM Dai, Y David, G Dee, J Dietzsch, O Drigert, M Esumi, S Filimonov, K French, A Johnson, SC Hall, JR Hemmick, TK Herrmann, N Hong, B Kwon, Y Lacasse, R Li, Q Ludlam, TW Mark, SK McCorkle, S Miskowiec, D O'Brien, E Panitkin, S Pantuev, V Paul, P Piazza, T Pollack, M Pruneau, C Qi, YJ Reber, E Rosati, M Sedykh, S Sheen, J Pollack, M Pruneau, C Qi, YJ Reber, E Rosati, M Sedykh, S Sheen, J Sonnadara, U Stachel, J Starinski, N Takagui, EM Pop, VT Trzaska, M Voloshin, S Vongpaseuth, TB Wang, G Wessels, JP Woody, CL Xu, N Zhang, Y Zou, C AF Barrette, J Bellwied, R Bennett, S Bersch, R Braun-Munzinger, P Chang, WC Cleland, WE Clemen, M Cole, J Cormier, TM Dai, Y David, G Dee, J Dietzsch, O Drigert, M Esumi, S Filimonov, K French, A Johnson, SC Hall, JR Hemmick, TK Herrmann, N Hong, B Kwon, Y Lacasse, R Li, Q Ludlam, TW Mark, SK McCorkle, S Miskowiec, D O'Brien, E Panitkin, S Pantuev, V Paul, P Piazza, T Pollack, M Pruneau, C Qi, YJ Reber, E Rosati, M Sedykh, S Sheen, J Pollack, M Pruneau, C Qi, YJ Reber, E Rosati, M Sedykh, S Sheen, J Sonnadara, U Stachel, J Starinski, N Takagui, EM Pop, VT Trzaska, M Voloshin, S Vongpaseuth, TB Wang, G Wessels, JP Woody, CL Xu, N Zhang, Y Zou, C CA E877 Collaborat TI Directed flow of antiprotons in Au plus Au collisions at AGS SO PHYSICS LETTERS B LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; HEAVY-ION COLLISIONS; AU+AU COLLISIONS; PHASE-TRANSITION; ELLIPTIC FLOW; EXPANSION; GEV/C; DISTRIBUTIONS; ANNIHILATION; TEMPERATURES AB Directed flow of antiprotons is studied in Au + An collisions at a beam momentum of 11.5A GeV/c. It is shown that antiproton directed flow is anti-correlated to proton flow. The measured transverse momentum dependence of the antiproton flow is compared with predictions of the RQMD event generator. (C) 2000 Elsevier Science B.V. All rights reserved. C1 McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Brookhaven Natl Lab, Upton, NY 11973 USA. Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Heidelberg, Inst Phys, D-69120 Heidelberg, Germany. Idaho Natl Engn Lab, Idaho Falls, ID 83402 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Sao Paulo, Dept Phys, BR-05508 Sao Paulo, Brazil. Wayne State Univ, Dept Phys, Detroit, MI 48202 USA. RP Barrette, J (reprint author), McGill Univ, Dept Phys, 3600 Univ St, Montreal, PQ H3A 2T8, Canada. RI Reber, Edward/B-4742-2017; Sonnadara, Upul/E-6359-2010; Voloshin, Sergei/I-4122-2013 OI Reber, Edward/0000-0001-8959-5570; Sonnadara, Upul/0000-0001-7862-2537; NR 47 TC 14 Z9 14 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 JUL 20 PY 2000 VL 485 IS 4 BP 319 EP 326 DI 10.1016/S0370-2693(00)00719-X PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 337HD UT WOS:000088350600001 ER PT J AU Barger, V Geer, S Raja, R Whisnant, K AF Barger, V Geer, S Raja, R Whisnant, K TI Determination of the pattern of neutrino masses at a neutrino factory SO PHYSICS LETTERS B LA English DT Article ID GEV ENERGY-RANGE; OSCILLATION EXPERIMENTS; ATMOSPHERIC NEUTRINOS; CP VIOLATION; PARAMETRIC-RESONANCE; SUPER-KAMIOKANDE; MATTER; RATIO; FLUX; PHYSICS AB We study the precision with which the sign of delta m(32)(2) can be determined at a neutrino factory, as a function of stored muon energies and baselines. This is done by simultaneously fitting the channels nu(mu)-->nu(mu), <(nu)over bar>(e) --> <(nu)over bar>(mu) from mu(-) decays and the channels <(nu)over bar>(mu) --> <(nu)over bar>(mu), nu(e) --> nu(mu) from mu(+) decays. For a 20 GeV muon storage ring we investigate as a function of the baseline length and the magnitude of delta m(32)(2), the minimum value of the parameter sin(2)2 theta(13) for which the sign of delta m(32)(2) can be determined to at least 3 standard deviations. We find that for baselines longer than similar to 3000 km, the sign of delta m(32)(2) can be determined for sin(2)2 theta(13) down to the 10(-3) level with 10(20) decays of 20 GeV muons. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. EM barger@pheno.physics.wisc.edu NR 66 TC 66 Z9 66 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUL 20 PY 2000 VL 485 IS 4 BP 379 EP 387 DI 10.1016/S0370-2693(00)00729-2 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 337HD UT WOS:000088350600010 ER PT J AU Shi, FG Nieh, TG Chou, YT AF Shi, FG Nieh, TG Chou, YT TI A free volume approach for self-diffusion in metals SO SCRIPTA MATERIALIA LA English DT Article DE self-diffusion; activation energy; van Limpt-Bugakov rule; free-volume approach C1 Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Shi, FG (reprint author), Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 11 TC 13 Z9 13 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUL 20 PY 2000 VL 43 IS 3 BP 265 EP 267 DI 10.1016/S1359-6462(00)00401-2 PG 3 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 352BP UT WOS:000089194900011 ER PT J AU Detours, V Perelson, AS AF Detours, V Perelson, AS TI The paradox of alloreactivity and self MHC restriction: Quantitative analysis and statistics SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID MAJOR HISTOCOMPATIBILITY COMPLEX; CELL REPERTOIRE SELECTION; T-CELLS; LYMPHOCYTIC CHORIOMENINGITIS; ANTIBODY REPERTOIRE; H-2 ANTIGENS; HELPER CELLS; RECOGNITION; THYMUS; SYSTEM AB Although 1-24% of T cells are alloreactive. i.e.. respond to MHC molecules encoded by a foreign haplotype, it is generally believed that T cells cannot recognize foreign peptides binding foreign MHC molecules. We show using a quantitative model that, if T cell selection and activation are affinity-driven, then an alloreactivity of 1-24% is incompatible with the textbook notion that self MHC restriction is absolute. If an average of 1% of clones are alloreactive, then according to our model, at most 20-fold more clones should, on average, be activated by antigens presented on self MHC than by antigens presented on foreign MHC. This ratio is at best 5 if alloreactivity is 5%. These results describe average properties of the murine immune system, but not the outcome of individual experiments. Using supercomputer technology, we simulated 100,000 MHC restriction experiments. Although the average restriction ratio was 7.1. restriction was absolute in 10% of the simulated experiments, greater than 100. although not absolute, in 29%, and below 6 in 24%. This extreme variability agrees with experimental estimates. Our analysis suggests that alloreactivity and average self MHC restriction both cannot be high, but that a low average restriction level is compatible with high levels in a significant number of experiments. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Perelson, AS (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, MS K710, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI28433] NR 53 TC 16 Z9 18 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 JUL 18 PY 2000 VL 97 IS 15 BP 8479 EP 8483 DI 10.1073/pnas.97.15.8479 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 335YF UT WOS:000088273900054 PM 10900009 ER PT J AU Gabrisch, H Mukherji, D AF Gabrisch, H Mukherji, D TI Character of dislocations at the gamma/gamma ' interfaces and internal stresses in nickel-base superalloys SO ACTA MATERIALIA LA English DT Article DE high temperature; dislocations; interface; microstructure; misfit stresses ID NETWORKS; CREEP AB It is experimentally observed in Ni-based superalloys that the dislocation substructure after deformation at elevated temperatures is different on horizontal and vertical gamma/gamma' interfaces. Edge dislocation networks are predominantly observed at horizontal interfaces while screw dislocation segments are seen mostly on the vertical interfaces. A crystallographic model of the critical shear stress for dipole expansion for screw and 60 degrees dislocation segments in the gamma/gamma' interfaces is used to explain the observations in high gamma' volume fraction (similar to 70%) alloys. However, the same model is found to be inadequate in explaining the substructure observations in those alloys with lower gamma' volume fraction (similar to 40%) which have wider matrix (gamma) channels (approximate to 180 nm). It is shown by superimposition of the dislocation's stress field, the internal coherency stresses and the externally applied stress that between 60 degrees and screw dislocation segments the former increase the internal stresses in vertical interfaces more than the latter. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Div Mat Sci, Berkeley, CA 94720 USA. Tech Univ Braunschweig, Inst Werkstoffe, D-38106 Braunschweig, Germany. RP Gabrisch, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Div Mat Sci, Berkeley, CA 94720 USA. RI Gabrisch, Heike/I-5021-2013 NR 13 TC 12 Z9 13 U1 0 U2 7 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 JUL 17 PY 2000 VL 48 IS 12 BP 3157 EP 3167 DI 10.1016/S1359-6454(00)00111-7 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CK UT WOS:000089196800013 ER PT J AU Hwang, SC Waser, R AF Hwang, SC Waser, R TI Study of electrical and mechanical contribution to switching in ferroelectric/ferroelastic polycrystals SO ACTA MATERIALIA LA English DT Article DE ferroelectricity; ferroelasticity; constitutive equations; nucleation, growth ID CERAMIC MULTILAYER ACTUATORS; MORPHOTROPIC-PHASE-BOUNDARY; FINITE-ELEMENT MODEL; THIN-FILMS; SIMULATION; STRESS; FIELD AB Polarization switching in a polycrystalline ferroelectric/ferroelastic ceramic is simulated with a finite element model. It is assumed that a crystallite switches if the reduction in potential energy of the polycrystal exceeds a critical energy barrier per unit volume of switching material. Each crystallite, represented by a cubic element in a finite element mesh, is a single domain that switches completely without a simulated domain wall motion. The possible dipole directions of each crystallite are assigned randomly subject to crystallographic constraints. The model accounts for electric field induced (i.e. ferroelectric) switching and stress induced (i.e, ferroelastic) switching without piezoelectric interaction. Different weights for the mechanical and electrical contribution to switching are selected phenomenologically to simulate electric displacement vs electric field and strain vs electric field of a ceramic lead lanthanum zirconate titanate (PLZT). Although the critical energy barriers for 90 degrees and 180 degrees switching are assumed to be the same, 90 degrees switching is favored when the electrical contribution to switching (i.e. electrical energy) is dominant, but 180 degrees switching is favored when the mechanical contribution to switching (i.e. elastic strain energy) is dominant. With increasing mechanical contribution and decreasing electrical contribution, the simulated electric displacement deviates from the Rayleigh law under a low applied electric field, and the shape of a switching region (or a process zone) changes from a prolonged ellipsoid to a sphere. (C) 2000 Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. Rhein Westfal TH Aachen, Inst Werkstoffe Elektrotech, D-52056 Aachen, Germany. RP Sandia Natl Labs, POB 5800,MS 0847, Albuquerque, NM 87185 USA. RI Waser, Rainer/J-6103-2013 OI Waser, Rainer/0000-0002-9080-8980 NR 41 TC 39 Z9 40 U1 1 U2 24 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 JUL 17 PY 2000 VL 48 IS 12 BP 3271 EP 3282 DI 10.1016/S1359-6454(00)00092-6 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CK UT WOS:000089196800025 ER PT J AU Li, Y Wong, GCL Case, R Safinya, CR Caine, E Hu, E Fernandez, P AF Li, Y Wong, GCL Case, R Safinya, CR Caine, E Hu, E Fernandez, P TI Characterizing the hard x-ray diffraction properties of a GaAs linear Bragg-Fresnel lens SO APPLIED PHYSICS LETTERS LA English DT Article ID CRYSTAL OPTICS; SCATTERING AB We investigated the diffractive focusing properties of (111) GaAs linear Bragg-Fresnel lenses (BFLs) developed for hard x-ray microscopy and microdiffraction of complex materials in confined geometries. We demonstrated that the use of GaAs yields significant processing advantages due to the reduced zone depth. Focal plane diffraction patterns of linear BFLs measured at the advanced photon source using 8-40 keV x rays were compared to a simple model based on Kirchhoff-Fresnel diffraction theory. Good agreement was obtained between experimental data and model calculations using only zones within an effective aperture defined by the transverse coherence of the source. (C) 2000 American Institute of Physics. [S0003-6951(00)00929-3]. C1 Univ Calif Santa Barbara, Dept Mat, Mat Res Lab, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Phys, Mat Res Lab, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Natl Nanofabricat Users Network, Santa Barbara, CA 93106 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Li, Y (reprint author), Univ Calif Santa Barbara, Dept Mat, Mat Res Lab, Santa Barbara, CA 93106 USA. OI Safinya, Cyrus/0000-0002-3295-7128 NR 15 TC 3 Z9 3 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 17 PY 2000 VL 77 IS 3 BP 313 EP 315 DI 10.1063/1.126961 PG 3 WC Physics, Applied SC Physics GA 332BB UT WOS:000088052200001 ER PT J AU Gungor, MR Maroudas, D Zhou, SJ AF Gungor, MR Maroudas, D Zhou, SJ TI Molecular-dynamics study of the mechanism and kinetics of void growth in ductile metallic thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTROMIGRATION; STRESS AB A molecular-dynamics study is presented of the mechanism and kinetics of void growth and morphological evolution in ductile metallic thin films subject to biaxial tensile strains. The void becomes faceted, grows, and relieves strain by emission from its surface of pairs of screw dislocations with opposite Burgers vectors. Repeated dislocation generation and propagation leads to formation of a step pattern on the film's surfaces. A simple phenomenological kinetic model of void growth is derived. Such kinetic equations can be used to formulate constitutive theories of plastic deformation for continuum-scale modeling of void evolution. (C) 2000 American Institute of Physics. [S0003-6951(00)00729-4]. C1 Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Gungor, MR (reprint author), Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. NR 15 TC 19 Z9 19 U1 0 U2 14 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 17 PY 2000 VL 77 IS 3 BP 343 EP 345 DI 10.1063/1.126971 PG 3 WC Physics, Applied SC Physics GA 332BB UT WOS:000088052200011 ER PT J AU Kim, Y Perry, CH Simmons, JA Klem, JF AF Kim, Y Perry, CH Simmons, JA Klem, JF TI In-plane magnetophotoluminescence studies of modulation-doped GaAs/AlGaAs coupled double quantum wells SO APPLIED PHYSICS LETTERS LA English DT Article ID INTERBAND OPTICAL-TRANSITIONS; ELECTRIC-FIELDS; MAGNETIC-FIELDS; PHOTOLUMINESCENCE AB In-plane magnetic-field photoluminescence spectra from a series of n-type modulation-doped GaAs/Al0.3Ga0.7As coupled double quantum wells show distinctive doublet structures related to the tunnel-split ground sublevel states. The magnetic-field behavior of the upper transition from the antisymmetric state strongly depends on sample mobility. In a lower mobility sample, the transition energy displays an N-type kink with field (namely, a maximum followed by a minimum), whereas higher mobility samples have a linear dependence. The former is attributed to a coupling mechanism due to homogeneous broadening of the electron and hole states. The results are in good agreement with recent theoretical calculations. (C) 2000 American Institute of Physics. [S0003-6951(00)04029-8]. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Dongguk Univ, Quantum Funct Semicond Res Ctr, Seoul, South Korea. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Perry, CH (reprint author), Northeastern Univ, Dept Phys, Boston, MA 02115 USA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 17 PY 2000 VL 77 IS 3 BP 388 EP 390 AR PII [S0003-6951(00)04029-8] DI 10.1063/1.126985 PG 3 WC Physics, Applied SC Physics GA 332BB UT WOS:000088052200026 ER PT J AU Kurtz, SR Allerman, AA Seager, CH Sieg, RM Jones, ED AF Kurtz, SR Allerman, AA Seager, CH Sieg, RM Jones, ED TI Minority carrier diffusion, defects, and localization in InGaAsN, with 2% nitrogen SO APPLIED PHYSICS LETTERS LA English DT Article ID BAND-GAP; ALLOY SCATTERING; SEMICONDUCTORS; GAAS1-XNX; GAINNAS; GAASN AB Electron and hole transport in compensated InGaAsN (approximate to 2% N) are examined through Hall mobility, photoconductivity, and solar cell photoresponse measurements. Short minority carrier diffusion lengths, photoconductive-response spectra, and doping dependent, thermally activated Hall mobilities reveal a broad distribution of localized states. At this stage of development, lateral carrier transport appears to be limited by large scale (much greater than mean free path) material inhomogeneities, not a random alloy-induced mobility edge. (C) 2000 American Institute of Physics. [S0003-6951(00)04629-5]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kurtz, SR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 140 Z9 141 U1 1 U2 28 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 17 PY 2000 VL 77 IS 3 BP 400 EP 402 AR PII [S0003-6951(00)04629-5] DI 10.1063/1.126989 PG 3 WC Physics, Applied SC Physics GA 332BB UT WOS:000088052200030 ER PT J AU Lauer, S VanWye, J Harrison, T McManus, H Samuel, BU Hiller, NL Mohandas, N Haldar, K AF Lauer, S VanWye, J Harrison, T McManus, H Samuel, BU Hiller, NL Mohandas, N Haldar, K TI Vacuolar uptake of host components, and a role for cholesterol and sphingomyelin in malarial infection SO EMBO JOURNAL LA English DT Article DE erythrocytes; microdomains; Plasmodium falciparum; trafficking ID GPI-ANCHORED PROTEINS; PLASMODIUM-FALCIPARUM; CELL-SURFACE; PARASITOPHOROUS VACUOLE; BIOLOGICAL-MEMBRANES; PLASMA-MEMBRANE; ERYTHROCYTES; PARASITES; CAVEOLAE; MICRODOMAINS AB Erythrocytes, which are incapable of endocytosis or phagocytosis, can be infected by the malaria parasite Plasmodium falciparum. We find that a transmembrane protein (Duffy), glycosylphosphatidylinositol (GPI)-anchored and cytoplasmic proteins, associated with detergent-resistant membranes (DRMs) that are characteristic of microdomains in host cell membranes, are internalized by vacuolar parasites, while the major integral membrane and cytoskeletal proteins are not. The internalized host proteins and a plasmodial transmembrane resident parasitophorous vacuolar membrane (PVM) protein are detected in DRMs associated with vacuolar parasites. This is the first report of a host transmembrane protein being recruited into an apicomplexan vacuole and of the presence of vacuolar DRMs; it establishes that integral association does not preclude protein internalization into the P.falciparum vacuole. Rather, as shown for Duffy, intracellular accumulation occurs at the same rate as that seen for a DRM-associated GPI-anchored protein. Furthermore, novel mechanisms regulated by the DRM lipids, sphingomyelin and cholesterol, mediate (i) the uptake of host DRM proteins and (ii) maintenance of the intracellular vacuole in the non-endocytic red cell, which may have implications for intracellular parasitism and pathogenesis. C1 Northwestern Univ, Dept Pathol, Chicago, IL 60611 USA. Northwestern Univ, Dept Microbiol Immunol, Chicago, IL 60611 USA. Stanford Univ, Sch Med, Dept Microbiol & Immunol, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Haldar, K (reprint author), Northwestern Univ, Dept Pathol, 303 E Chicago Ave, Chicago, IL 60611 USA. RI Haldar, Kasturi/C-6685-2014; Hiller, N. Luisa/A-3739-2016 OI Hiller, N. Luisa/0000-0001-6572-1368 FU NIAID NIH HHS [AI39071, R01 AI039071]; NIDDK NIH HHS [DK32094, P01 DK032094] NR 39 TC 156 Z9 158 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0261-4189 J9 EMBO J JI Embo J. PD JUL 17 PY 2000 VL 19 IS 14 BP 3556 EP 3564 DI 10.1093/emboj/19.14.3556 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 338WV UT WOS:000088447000005 PM 10899110 ER PT J AU Valla, T Kralj, M Siber, A Milun, M Pervan, P Johnson, PD Woodruff, DP AF Valla, T Kralj, M Siber, A Milun, M Pervan, P Johnson, PD Woodruff, DP TI Oscillatory electron-phonon coupling in ultra-thin silver films on V(100) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID QUANTUM-WELL STATES; ANGLE-RESOLVED PHOTOEMISSION; SURFACE; SYSTEM; AG AB The temperature dependence of peak widths in high-resolution angle-resolved photoelectron spectroscopy from quantum well states in ultra-thin Ag films on V(100) has been used to determine the electron-phonon coupling constant, lambda, for films of thickness 1-8 layers. A strong oscillatory variation in coupling strength is observed as a function of film thickness, peaking at a two layer film for which lambda similar or equal to 1.0. A simple theory incorporating interaction of the photo-hole with the thermal vibrations of the potential step at the adlayer-vacuum interface is shown to reproduce the main features of these results. C1 Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Inst Phys, Zagreb, Croatia. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Woodruff, DP (reprint author), Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RI Kralj, Marko/A-8232-2008; Pervan, Petar/F-8142-2010; Siber, Antonio/B-8881-2008; Milun, Milorad/A-3420-2010 OI Kralj, Marko/0000-0002-9786-3130; Pervan, Petar/0000-0002-0273-2737; Siber, Antonio/0000-0003-1665-6541; NR 20 TC 40 Z9 40 U1 0 U2 6 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 JUL 17 PY 2000 VL 12 IS 28 BP L477 EP L482 DI 10.1088/0953-8984/12/28/105 PG 6 WC Physics, Condensed Matter SC Physics GA 341GH UT WOS:000088582300005 ER PT J AU Dersch, U Akchurin, N Andreev, VA Atamantchouk, AG Aykac, M Balatz, MY Bondar, NF Bravar, A Cooper, PS Dauwe, LJ Davidenko, GV Dirkes, G Dolgolenko, AG Dreossi, D Dzyubenko, GB Edelstein, R Emediato, L Endler, AMF Engelfried, J Eschrich, I Escobar, CO Evdokimov, AV Filimonov, IS Garcia, FG Gaspero, M Gerzon, S Giller, I Golovtsov, VL Goncharenko, YM Gottschalk, E Gouffon, P Grachov, OA Gulmez, E Kangling, H Iori, M Jun, SY Kamenskii, AD Kaya, M Kilmer, J Kim, VT Kochenda, LM Konigsmann, K Konorov, I Kozhevnikov, AP Krivshich, AG Kruger, H Kubantsev, MA Kubarovsky, VP Kulyavtsev, AI Kuropatkin, NP Kurshetsov, VF Kushnirenko, A Kwan, S Lach, J Lamberto, A Landsberg, LG Larin, I Leikin, EM Li, YS Li, ZG Luksys, M Lungov, T Magarrel, D Maleev, VP Mao, D Mao, CS Mao, ZL Masciocchi, S Mathew, P Mattson, M Matveev, V McCliment, E McKenna, SL Moinester, MA Molchanov, VV Morelos, A Mukhin, VA Nelson, KD Nemitkin, AV Neoustroev, PV Newsom, C Nilov, AP Nurushev, SB Ocherashvili, A Oleynik, G Onel, Y Ozel, E Ozkorucuklu, S Patrichev, S Penzo, A Petrenko, SI Pogodin, P Povh, B Procario, M Prutskoi, VA Ramberg, E Rapazzo, GF Razmyslovich, BV Rud, VI Russ, J Scheglov, Y Schiavon, P Semyatchkin, VK Simon, J Sitnikov, AI Skow, D Smith, VJ Srivastava, M Steiner, V Stepanov, V Skutte, L Svoiski, M Terentyev, NK Thomas, GP Uvarov, LN Vasiliev, AN Vavilov, DV Verebryusov, VS Victorov, VA Vishnyakov, VE Vorobyov, AA Vorwalter, K You, J Zhao, WH Zheng, SC Zukanovich-Funchal, R AF Dersch, U Akchurin, N Andreev, VA Atamantchouk, AG Aykac, M Balatz, MY Bondar, NF Bravar, A Cooper, PS Dauwe, LJ Davidenko, GV Dirkes, G Dolgolenko, AG Dreossi, D Dzyubenko, GB Edelstein, R Emediato, L Endler, AMF Engelfried, J Eschrich, I Escobar, CO Evdokimov, AV Filimonov, IS Garcia, FG Gaspero, M Gerzon, S Giller, I Golovtsov, VL Goncharenko, YM Gottschalk, E Gouffon, P Grachov, OA Gulmez, E Kangling, H Iori, M Jun, SY Kamenskii, AD Kaya, M Kilmer, J Kim, VT Kochenda, LM Konigsmann, K Konorov, I Kozhevnikov, AP Krivshich, AG Kruger, H Kubantsev, MA Kubarovsky, VP Kulyavtsev, AI Kuropatkin, NP Kurshetsov, VF Kushnirenko, A Kwan, S Lach, J Lamberto, A Landsberg, LG Larin, I Leikin, EM Li, YS Li, ZG Luksys, M Lungov, T Magarrel, D Maleev, VP Mao, D Mao, CS Mao, ZL Masciocchi, S Mathew, P Mattson, M Matveev, V McCliment, E McKenna, SL Moinester, MA Molchanov, VV Morelos, A Mukhin, VA Nelson, KD Nemitkin, AV Neoustroev, PV Newsom, C Nilov, AP Nurushev, SB Ocherashvili, A Oleynik, G Onel, Y Ozel, E Ozkorucuklu, S Patrichev, S Penzo, A Petrenko, SI Pogodin, P Povh, B Procario, M Prutskoi, VA Ramberg, E Rapazzo, GF Razmyslovich, BV Rud, VI Russ, J Scheglov, Y Schiavon, P Semyatchkin, VK Simon, J Sitnikov, AI Skow, D Smith, VJ Srivastava, M Steiner, V Stepanov, V Skutte, L Svoiski, M Terentyev, NK Thomas, GP Uvarov, LN Vasiliev, AN Vavilov, DV Verebryusov, VS Victorov, VA Vishnyakov, VE Vorobyov, AA Vorwalter, K You, J Zhao, WH Zheng, SC Zukanovich-Funchal, R CA SELEX Collaboration TI Total cross section measurements with pi(-), Sigma(-) and protons on nuclei and nucleons around 600 GeV/c SO NUCLEAR PHYSICS B LA English DT Article DE total cross sections; glauber model; hyperon reactions ID INTERSECTING STORAGE-RINGS; PP ELASTIC-SCATTERING; ANTIPROTON PROTON; REAL PART; GEV-C; AMPLITUDE AB Total cross sections for Sigma(-) and pi(-) on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600 GeV/c. These measurements were performed with a transmission technique in the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma(tot)(Sigma(-)N) and sigma(tot)(pi(-)N), which were deduced from nuclear cross sections. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Moscow State Univ, Moscow, Russia. Petersburg Nucl Phys Inst, St Petersburg, Russia. Tel Aviv Univ, IL-69978 Ramat Aviv, Israel. Univ Autonoma San Luis Potosi, San Luis Potosi, Mexico. Univ Fed Paraiba, BR-58059900 Joao Pessoa, Paraiba, Brazil. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ Iowa, Iowa City, IA 52242 USA. Univ Michigan, Flint, MI 48502 USA. Univ Rome La Sapienza, Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Univ Sao Paulo, Sao Paulo, Brazil. Univ Trieste, Trieste, Italy. Ist Nazl Fis Nucl, Trieste, Italy. Ball State Univ, Muncie, IN 47306 USA. Bogazici Univ, TR-80815 Bebek, Istanbul, Turkey. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Fermilab, Batavia, IL 60510 USA. Inst High Energy Phys, Protvino, Russia. Inst High Energy Phys, Beijing 100039, Peoples R China. Inst Theoret & Expt Phys, Moscow 117259, Russia. RP Dersch, U (reprint author), Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. RI Zukanovich Funchal, Renata/C-5829-2013; Russ, James/P-3092-2014; Gulmez, Erhan/P-9518-2015; Gouffon, Philippe/I-4549-2012; Maleev, Victor/R-4140-2016; OI Zukanovich Funchal, Renata/0000-0001-6749-0022; Russ, James/0000-0001-9856-9155; Gulmez, Erhan/0000-0002-6353-518X; Gouffon, Philippe/0000-0001-7511-4115; Jun, Soon Yung/0000-0003-3370-6109 NR 39 TC 42 Z9 42 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 17 PY 2000 VL 579 IS 1-2 BP 277 EP 312 DI 10.1016/S0550-3213(00)00204-2 PG 36 WC Physics, Particles & Fields SC Physics GA 331UQ UT WOS:000088037400011 ER PT J AU Barci, DG Fraga, ES Ramos, RO AF Barci, DG Fraga, ES Ramos, RO TI Nonequilibrium field theory description of the Bose-Einstein condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAS; SUPERFLUIDITY; TRAP AB We study the detailed out-of-equilibrium time evolution of a homogeneous Bose-Einstein condensate (BEC). We consider a nonrelativistic quantum theory for a self-interacting complex scalar field, immersed in a thermal bath, as an effective microscopic model for the description of the BEG. The interaction between fluctuations proves to be crucial in the mechanism of instability generation. We show the existence of two regimes in k space, with a crossover for k(2)/2m similar to 2 lambda\phi(0)\(2), where lambda is the coupling constant and \phi(0)\(2) is the condensate density. We deduce and solve a set of coupled equations that completely determines the nonequilibrium dynamics of the condensate density. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Estado Rio De Janeiro, Inst Fis, Dept Fis Teor, BR-20550013 Rio De Janeiro, Brazil. RP Barci, DG (reprint author), Univ Illinois, Dept Phys, 1100 W Green St, Urbana, IL 61801 USA. RI Ramos, Rudnei/C-4492-2008; Barci, Daniel /H-8532-2013; Fraga, Eduardo/H-6010-2016 OI Ramos, Rudnei/0000-0001-8781-4928; Barci, Daniel /0000-0001-5266-8780; Fraga, Eduardo/0000-0001-5340-156X NR 21 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 17 PY 2000 VL 85 IS 3 BP 479 EP 482 DI 10.1103/PhysRevLett.85.479 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900001 PM 10991320 ER PT J AU Shvyd'ko, YV Lerche, M Jaschke, J Lucht, M Gerdau, E Gerken, M Ruter, HD Wille, HC Becker, P Alp, EE Sturhahn, W Sutter, J Toellner, TS AF Shvyd'ko, YV Lerche, M Jaschke, J Lucht, M Gerdau, E Gerken, M Ruter, HD Wille, HC Becker, P Alp, EE Sturhahn, W Sutter, J Toellner, TS TI gamma-ray wavelength standard for atomic scales SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY; SILICON; DIFFRACTION AB The wavelength of the Fe-57 Mossbauer radiation is measured with a relative uncertainty of 0.19 ppm by using almost exact Bragg backscattering from a reference silicon crystal. its value is determined as lambda(M) = 0.86025474(16) x 10(-10) m. The corresponding Mossbauer photon energy is E-M = 14412.397(3) eV. Tho wavelength of the Fe-57 Mossbauer radiation is easily reproducible with an accuracy of at least 10(-11) lambda(M) and could be used as a length standard of atomic dimensions. C1 Univ Hamburg, Inst Expt Phys 2, D-22761 Hamburg, Germany. Phys Tech Bundesanstalt, D-38023 Braunschweig, Germany. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Shvyd'ko, YV (reprint author), Univ Hamburg, Inst Expt Phys 2, D-22761 Hamburg, Germany. RI Wille, Hans-Christian/C-3881-2013 NR 19 TC 29 Z9 29 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 JUL 17 PY 2000 VL 85 IS 3 BP 495 EP 498 DI 10.1103/PhysRevLett.85.495 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900005 PM 10991324 ER PT J AU Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamnov, S Kopp, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kravchenko, I Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Lorenc, J Pedlar, TK Schwarthoff, H von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V AF Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamnov, S Kopp, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kravchenko, I Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Lorenc, J Pedlar, TK Schwarthoff, H von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V TI Observation of B -> K-+/-pi(0) and B -> K-0 pi(0) and evidence for B ->pi(+)pi(-) SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIRECT CP VIOLATION; CKM-ANGLE-GAMMA; PENGUIN CONTRIBUTIONS; NONLEPTONIC DECAYS; PI-PI; MESONS; OBSERVABLES; ASYMMETRIES; ELECTROWEAK; DETECTOR AB We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions and observe three new processes with the following branching fractions: B(B --> pi(+)pi(-)) = (4.3(-1.4)(+1.6) +/- 0.5) X 10(-6), B(B --> K(0)pi(0)) = (14.6(-5.1)(-3.3)(+5.9)(+2.1)) X 10(-6), and B(B --> K(+/-)pi(0)) = (11.6(-2.7)(-1.3)(+3.0)(+1.4)) X 10(-6). We also update our previous measurements for the decays B --> K(+/-)pi(+/-) and B+/- --> K(0)pi(+/-). C1 Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Yonsei Univ, Seoul 120749, South Korea. Univ Cincinnati, Cincinnati, OH 45221 USA. MIT, Cambridge, MA 02139 USA. Univ Texas Pan Amer, Edinburg, TX 78539 USA. RP Cronin-Hennessy, D (reprint author), Univ Rochester, 601 Elmwood Ave, Rochester, NY 14627 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014; OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674; Poling, Ronald/0000-0001-7305-4702 NR 31 TC 99 Z9 99 U1 2 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 JUL 17 PY 2000 VL 85 IS 3 BP 515 EP 519 DI 10.1103/PhysRevLett.85.515 PG 5 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900010 PM 10991329 ER PT J AU Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamnov, S Kopp, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kravchenko, I Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Lorenc, J Pedlar, TK Schwarthoff, H von Toerne, E Zoeller, MM AF Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamnov, S Kopp, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kravchenko, I Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Lorenc, J Pedlar, TK Schwarthoff, H von Toerne, E Zoeller, MM TI Two-body B meson decays to eta and eta ': Observation of B ->eta K SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP-VIOLATION; SEARCH; DETECTOR; MODES AB In a sample of 19 x 10(6) produced B mesons, we have observed the decays B --> eta K* and improved our previous measurements of B --> eta'K. The branching fractions we measure for these decay modes are B(B+ --> eta K*(+)) = (26.4(-8.2)(+9.6) +/- 3.3) X 10(-6), B(B-0 --> eta K*(0)) = (13.8(-4.6)(+5.5) +/- 1.6) X 10(-6) B(B+ --> eta'K+) = (80(-9)(+10) +/- 7) X 10(-6), and B(B-0 --> eta'K-0) = (89(-16)(+18) +/- 9) X 10(-6). We have searched with comparable sensitivity for related decays and report upper limits for these branching fractions. C1 Univ Rochester, Rochester, NY 14627 USA. Purdue Univ, W Lafayette, IN 47907 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Yonsei Univ, Seoul 120749, South Korea. Univ Cincinnati, Cincinnati, OH 45221 USA. MIT, Cambridge, MA 02139 USA. Univ Texas Pan Amer, Edinburg, TX 78539 USA. Univ Oklahoma, Norman, OK 73019 USA. RP Richichi, SJ (reprint author), Univ Rochester, 601 Elmwood Ave, Rochester, NY 14627 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014 OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039 NR 20 TC 111 Z9 111 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 JUL 17 PY 2000 VL 85 IS 3 BP 520 EP 524 DI 10.1103/PhysRevLett.85.520 PG 5 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900011 PM 10991330 ER PT J AU Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamnov, S Kopp, S Majumder, G Moneti, GC Mountain, R Sohuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kravchenko, I Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Lorenc, J Pedlar, TK Schwarthoff, H von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A AF Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamnov, S Kopp, S Majumder, G Moneti, GC Mountain, R Sohuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kravchenko, I Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Lorenc, J Pedlar, TK Schwarthoff, H von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A TI Measurement of charge asymmetries in charmless hadronic B meson decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIRECT CP VIOLATION; B->K-PI DECAYS; DETECTOR; GAMMA AB We search for CP-violating charge asymmetries (A(CP)) in the B meson decays to K+/- pi(+/-), K+/- pi(0), K(S)(0)pi(+/-), K+/- eta', and omega pi(+/-). Using 9.66 million Y(4S) decays collected with the CLEO detector, the statistical precision on A(CP) is in the range of +/-0.12 to +/-0.25 depending on decay mode. While CP-violating asymmetries of up to +/-0.5 are possible within the standard model, the measured asymmetries are consistent with zero in all five decay modes studied. C1 Univ Rochester, Rochester, NY 14627 USA. Purdue Univ, W Lafayette, IN 47907 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Yonsei Univ, Seoul 120749, South Korea. Univ Cincinnati, Cincinnati, OH 45221 USA. MIT, Cambridge, MA 02139 USA. Univ Texas Pan Amer, Edinburg, TX 78539 USA. RP Chen, S (reprint author), Univ Rochester, 601 Elmwood Ave, Rochester, NY 14627 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014; OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674 NR 25 TC 97 Z9 97 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 JUL 17 PY 2000 VL 85 IS 3 BP 525 EP 529 DI 10.1103/PhysRevLett.85.525 PG 5 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900012 PM 10991331 ER PT J AU Robin, D Steier, C Laskar, J Nadolski, L AF Robin, D Steier, C Laskar, J Nadolski, L TI Global dynamics of the advanced light source revealed through experimental frequency map analysis SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYSTEMS AB Frequency map analysis was first used for the dynamical study of numerical simulations of physical systems (solar system, galaxies, particle accelerators). Here it is applied directly to the experimental results obtained at the Advanced Light Source. For the first time, the network of coupling resonances is clearly visible in an experiment, in a similar way as in the numerical simulation. Excellent agreement between numerical and experimental results leads us to propose this technique as a tool for improving numerical models and actual behavior of particle accelerators. Moreover, it provides a model-independent diagnostic for the evaluation of the dynamical properties of the beam. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. IMC, CNRS, F-75014 Paris, France. RP Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Laskar, Jacques/E-1098-2011; OI Laskar, Jacques/0000-0003-2634-789X; Nadolski, Laurent/0000-0003-1174-5940 NR 12 TC 37 Z9 37 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 17 PY 2000 VL 85 IS 3 BP 558 EP 561 DI 10.1103/PhysRevLett.85.558 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900020 PM 10991339 ER PT J AU Mitrinovic, DM Tikhonov, AM Li, M Huang, ZQ Schlossman, ML AF Mitrinovic, DM Tikhonov, AM Li, M Huang, ZQ Schlossman, ML TI Noncapillary-wave structure at the water-alkane interface SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY REFLECTIVITY; MOLECULAR-DYNAMICS; SURFACE-ROUGHNESS; CAPILLARY WAVES; VAPOR INTERFACE; SCATTERING; TENSION AB Synchrotron x-ray reflectivity is used to study the interface between bulk water and bulk n-alkanes with carbon numbers 6 through 10, 12, 16, and 22. For all interfaces, except the water-hexane interface, the interfacial width disagrees with the prediction from capillary-wave theory. The variation of interfacial width with carbon number can be described by combining the capillary-wave prediction for the width with a contribution from intrinsic structure. This intrinsic structure is determined by the gyration radius for the shorter alkanes and by the bulk correlation length for the longer alkanes. C1 Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. RP Schlossman, ML (reprint author), Univ Illinois, Dept Phys, 845 W Taylor St, Chicago, IL 60607 USA. RI Tikhonov, Aleksey/N-1111-2016 NR 26 TC 144 Z9 146 U1 2 U2 23 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 JUL 17 PY 2000 VL 85 IS 3 BP 582 EP 585 DI 10.1103/PhysRevLett.85.582 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900026 PM 10991345 ER PT J AU Hoyt, JJ Asta, M Sadigh, B AF Hoyt, JJ Asta, M Sadigh, B TI Test of the universal scaling law for the diffusion coefficient in liquid metals SO PHYSICAL REVIEW LETTERS LA English DT Article ID EMBEDDED-ATOM-METHOD; COMPUTER-SIMULATION; TRANSITION-METALS; MOLECULAR-DYNAMICS; NI; ALLOYS; MODEL; CU AB The recently proposed scaling law relating the diffusion coefficient and the excess entropy of a liquid [M. Dzugutov, Nature (London) 381, 137 (1996)] is tested for several metals using molecular dynamics simulations. Interatomic potentials derived from the embedded atom method are used to study Ag, Au, Cu, Ni, Pd, Pt, Ni3Al, and AuPt and the angular dependent Stillinger-Weber form is used to investigate Si. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hoyt, JJ (reprint author), Sandia Natl Labs, MS 9161,POB 969, Livermore, CA 94551 USA. NR 23 TC 121 Z9 121 U1 2 U2 32 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 JUL 17 PY 2000 VL 85 IS 3 BP 594 EP 597 DI 10.1103/PhysRevLett.85.594 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900029 PM 10991348 ER PT J AU Feibelman, PJ AF Feibelman, PJ TI Formation and diffusion of S-decorated Cu clusters onc Cu(111) SO PHYSICAL REVIEW LETTERS LA English DT Article ID ABINITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; SURFACE SELF-DIFFUSION; WAVE BASIS-SET; ULTRASOFT PSEUDOPOTENTIALS; METALS; HYDROGEN; GROWTH AB S-decorated Cu trimers are a likely agent of S-enhanced Cu transport between islands on Cu(111). According to nb initio calculations, excellent S bonding to trimer-Cu dangling valence results in an ad-Cu3S3 formation energy of only similar to 0.28 eV, compared to 0.79 eV for a self-adsorbed Cu atom, and a diffusion barrier less than or equal to 0.35 eV. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 25 TC 60 Z9 61 U1 2 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 17 PY 2000 VL 85 IS 3 BP 606 EP 609 DI 10.1103/PhysRevLett.85.606 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900032 PM 10991351 ER PT J AU Ono, S Ando, Y Murayama, T Balakirev, FF Betts, JB Boebinger, GS AF Ono, S Ando, Y Murayama, T Balakirev, FF Betts, JB Boebinger, GS TI Metal-to-insulator crossover in the low-temperature normal state of Bi2Sr2-xLaxCuO6+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID LA2-XSRXCUO4; RESISTIVITY; SUPERCONDUCTIVITY; BEHAVIOR; CUPRATE; INPLANE; POWER; LIMIT AB We measure the normal-state in-plane resistivity of Bi2Sr2-xLaxCuO6+delta single crystals at low temperatures by suppressing superconductivity with 60 T pulsed magnetic fields. With decreasing hole doping, we observe a crossover from a metallic to an insulating behavior in the low-temperature normal state. This crossover is estimated to occur near 1/8 doping, well inside the underdoped regime, and not at optimum doping as reported for other cuprates. The insulating regime is marked by a logarithmic temperature dependence of the resistivity over two decades of temperature, suggesting that a peculiar charge localization is common to the cuprates. C1 Cent Res Inst Elect Power Ind, Komae, Tokyo 2018511, Japan. Sci Univ Tokyo, Dept Phys, Tokyo 1628601, Japan. Univ Calif Los Alamos Natl Lab, NHMFL, Los Alamos, NM 87545 USA. RP Ando, Y (reprint author), Cent Res Inst Elect Power Ind, Komae, Tokyo 2018511, Japan. RI Ando, Yoichi/B-8163-2013 OI Ando, Yoichi/0000-0002-3553-3355 NR 17 TC 168 Z9 168 U1 1 U2 19 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 JUL 17 PY 2000 VL 85 IS 3 BP 638 EP 641 DI 10.1103/PhysRevLett.85.638 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900040 PM 10991359 ER PT J AU Curro, NJ Hammel, PC Suh, BJ Hucker, M Buchner, B Ammerahl, U Revcolevschi, A AF Curro, NJ Hammel, PC Suh, BJ Hucker, M Buchner, B Ammerahl, U Revcolevschi, A TI Inhomogeneous low frequency spin dynamics in La1.65Eu0.2Sr0.15CuO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID TEMPERATURE TETRAGONAL PHASE; DOPED LA2-XSRXCUO4; ORDER; NQR; SUPERCONDUCTIVITY; LA5/3SR1/3NIO4; FLUCTUATIONS; STRIPES; GLASS; HOLES AB We report Cu and La nuclear magnetic resonance measurements in the title compound that reveal an inhomogeneous glassy behavior of the spin dynamics. A low temperature peak in the La spin lattice relaxation rate and the "wipeout" of Cu intensity both arise from these slow electronic spin fluctuations that reveal a distribution of activation energies. Inhomogeneous slowing of spin fluctuations appears to be a general feature of doped lanthanum cuprate. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Catholic Univ Korea, Div Nat Sci, Seoul, South Korea. Univ Cologne, Inst Phys 2, D-5000 Cologne 41, Germany. Univ Paris 11, Chim Solide Lab, F-91405 Orsay, France. RP Curro, NJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Hammel, P Chris/O-4845-2014; Buchner, Bernd/E-2437-2016; Curro, Nicholas/D-3413-2009 OI Hammel, P Chris/0000-0002-4138-4798; Buchner, Bernd/0000-0002-3886-2680; Curro, Nicholas/0000-0001-7829-0237 NR 33 TC 95 Z9 95 U1 3 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 17 PY 2000 VL 85 IS 3 BP 642 EP 645 DI 10.1103/PhysRevLett.85.642 PG 4 WC Physics, Multidisciplinary SC Physics GA 334GZ UT WOS:000088179900041 PM 10991360 ER PT J AU Trabert, E Utter, SB Beiersdorfer, P AF Trabert, E Utter, SB Beiersdorfer, P TI Visible-range spectroscopy and a lifetime measurement on Kr22+ in an electron beam ion trap SO PHYSICS LETTERS A LA English DT Article ID TRANSITION-PROBABILITIES; FORBIDDEN LINES; SPECTRA; LEVEL AB The 3s(2)3p(2) P-3(1)-P-3(2) transition in the Si-like ion Kr22+ has been studied using an electron beam ion trap (EBIT). A new wavelength value, (384.14 +/- 0.02) nm, results from employing a novel spectrometer system that combines high speed and higher spectral resolution than applied before. The spectral resolution is high enough to observe source broadening. A new lifetime measurement [(6.82 +/- 0.1) ms] differs from previous results (including our own) and now corroborates semiempirically scaled calculations. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94551 USA. RP Trabert, E (reprint author), Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany. NR 27 TC 26 Z9 26 U1 0 U2 0 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 JUL 17 PY 2000 VL 272 IS 1-2 BP 86 EP 92 DI 10.1016/S0375-9601(00)00397-2 PG 7 WC Physics, Multidisciplinary SC Physics GA 336VH UT WOS:000088323300013 ER PT J AU Kiselev, SA Phillips, A Gabitov, I AF Kiselev, SA Phillips, A Gabitov, I TI Long scale evolution of a nonlinear stochastic dynamic system for modeling market price bubbles SO PHYSICS LETTERS A LA English DT Article DE complex dynamics; stochastic processes; theory and models of chaotic systems; non-equilibrium phenomena ID STOCK-MARKET; BEHAVIOR AB This Letter investigates the stochastic dynamics of a simplified agent-based microscopic model describing stock market evolution. Our mathematical model includes a stochastic market and a sealed-bid double auction. The dynamics of the model are determined by the game of two types of traders: (i) 'intelligent' traders whose strategy is based on nonlinear technical data analysis' and (ii) 'random' traders that act without a consistent strategy. We demonstrate the effect of time-scale separations on the market dynamics. We study the characteristics of the market relaxation in response to perturbations caused by large cash flows generated between these two groups of traders. We also demonstrate that our model exhibits the formation of a price bubble(2) and the subsequent transition to a bear market(3). (C) 2000 Published by EIsevier Science B.V. C1 CyLogix, Princeton, NJ 08550 USA. Russian Acad Sci, Inst Spect, Troitsk 142092, Moscow Region, Russia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Russian Acad Sci, LD Landau Theoret Phys Inst, Moscow 117940, Russia. RP Kiselev, SA (reprint author), CyLogix, Princeton Junct, Princeton, NJ 08550 USA. NR 18 TC 5 Z9 5 U1 1 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 JUL 17 PY 2000 VL 272 IS 1-2 BP 130 EP 142 DI 10.1016/S0375-9601(00)00415-1 PG 13 WC Physics, Multidisciplinary SC Physics GA 336VH UT WOS:000088323300020 ER PT J AU Dannenberg, R Stach, EA Groza, JR Dresser, BJ AF Dannenberg, R Stach, EA Groza, JR Dresser, BJ TI In-situ TEM observations of abnormal grain growth, coarsening, and substrate de-wetting in nanocrystalline Ag thin films SO THIN SOLID FILMS LA English DT Article DE transmission electron microscopy; substrate de-wetting; nanocrystalline Ag thin films ID COPPER; SILVER AB Abnormal grain growth is studied in nanocrystalline sputtered Ag films. Eighty nanometer thick Ag films are DC sputter deposited onto back-etched amorphous silicon nitride membranes. Specimens are annealed in a heating stage in an in-situ TEM for various temperatures and hold times. With the same specimen, we proceed to higher temperatures after the apparent halt of growth for sufficiently long hold times. The grain size distribution of the as-deposited films is bi-modal, with large abnormal grains with 100 nm diameters, embedded in a matrix of smaller grains of 15 nm diameters. Coarsening begins at temperatures of approximately 100 degrees C, and quickly reaches a plateau. The growth process restarts only after sufficient temperature increases, and plateaus at each succeeding temperature. Using a variation of the Mullins-Von Neumann law, the activation energy for the abnormal growth is found to be 0.274 eV, consistent with the value reported for pore formation during electromigration via surface diffusion in Ag. Grain growth appears to stop above temperatures of 350 degrees C, eventually leading to triple junction pore formation at 350 degrees C and de-wetting of the film from the substrate at 600 degrees C. The de-wetting is the high temperature limit of the thermal grooving which cancels the driving force for grain growth at the lower temperatures. TEM images as evidence of this effect are presented, along with observations on the pore formation that support surface diffusion as the mass transport mechanism for grooving, Fore formation, and as the limiting mass transport mechanism for the grain growth. (C) 2000 Elsevier Science S.A. All rights reserved. C1 BOC Coating Technol, Fairfield, CA 94533 USA. Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Chem Engn Mat Sci, Davis, CA 95616 USA. RP Dannenberg, R (reprint author), BOC Coating Technol, 2700 Maxwell Way, Fairfield, CA 94533 USA. RI Stach, Eric/D-8545-2011 OI Stach, Eric/0000-0002-3366-2153 NR 19 TC 50 Z9 51 U1 2 U2 51 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 JUL 17 PY 2000 VL 370 IS 1-2 BP 54 EP 62 DI 10.1016/S0040-6090(99)00947-5 PG 9 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 330BD UT WOS:000087942200010 ER PT J AU Hofmann, DM Meyer, BK Alves, H Leiter, F Burkhard, W Romanov, N Kim, Y Kruger, J Weber, ER AF Hofmann, DM Meyer, BK Alves, H Leiter, F Burkhard, W Romanov, N Kim, Y Kruger, J Weber, ER TI The red (1.8 eV) luminescence in epitaxially grown GaN SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED 2000) CY MAR 06-10, 2000 CL BERLIN, GERMANY ID SEMICONDUCTORS; RESONANCE; COMPLEXES; ORIGIN; FILMS AB The 1.8 eV luminescence band in GaN grown by molecular beam epitaxy is studied by photo-luminescence (PL) and magnetic resonance. Optically detected magnetic resonance (ODMR) shows that deep centres with g = 1.98 and g = 2.01 are involved in the recombination. The results of the PL experiments indicate that the 1.8 eV recombination can be further fed by shallow centres like shallow donors or excitons. C1 Univ Giessen, Inst Phys 1, D-35392 Giessen, Germany. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Hofmann, DM (reprint author), Univ Giessen, Inst Phys 1, Heinrich Buff Ring 16, D-35392 Giessen, Germany. NR 11 TC 33 Z9 33 U1 0 U2 6 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 JUL 16 PY 2000 VL 180 IS 1 BP 261 EP 265 DI 10.1002/1521-396X(200007)180:1<261::AID-PSSA261>3.0.CO;2-2 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 341TP UT WOS:000088605900044 ER PT J AU Kang, SH Gong, XY Yeung, ES AF Kang, SH Gong, XY Yeung, ES TI High-throughput comprehensive peptide mapping of proteins by multiplexed capillary electrophoresis SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; ZONE-ELECTROPHORESIS; ARRAY ELECTROPHORESIS; GEL-ELECTROPHORESIS; FRAGMENTS; BIOTECHNOLOGY; DIGESTION; TRYPSIN; SYSTEM AB A novel multimodal method for peptide mapping of proteins by multiplexed capillary electrophoresis (CE) is presented. By combining charge to size separations in four different channels and micellar electrokinetic chromatography for hydrophobicity-based separations in two different channels in a 96-capillary array, peptide fragments of digested proteins were readily resolved and showed unique fingerprints. Each capillary spanned several diodes in a photodiode array (PDA) for absorption measurement. The 96 capillaries were monitored simultaneously at 214 nm by a single PDA element with 1024 diodes, and analysis was completed within 45 min. This demonstrates that it is possible to rapidly screen biotechnological products as well as to efficiently optimize separation conditions in CE by a combinatorial approach. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 37 TC 47 Z9 49 U1 1 U2 2 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 JUL 15 PY 2000 VL 72 IS 14 BP 3014 EP 3021 DI 10.1021/ac0000832 PG 8 WC Chemistry, Analytical SC Chemistry GA 337FQ UT WOS:000088347100002 PM 10939361 ER PT J AU Conrads, TP Anderson, GA Veenstra, TD Pasa-Tolic, L Smith, RD AF Conrads, TP Anderson, GA Veenstra, TD Pasa-Tolic, L Smith, RD TI Utility of accurate mass tags for proteome-wide protein identification SO ANALYTICAL CHEMISTRY LA English DT Article ID COMPLETE GENOME SEQUENCE; SPECTROMETRY; DATABASES; PAGE AB An enabling capability for proteomics would be the ability to study protein expression on a global scale. While several different: separation and analysis options are being investigated to advance the practice of proteomics, mass spectrometry (MS) is rapidly becoming the core instrumental technology used to characterize the large number of proteins that constitute a proteome. To be most effective, proteomic measurements must be high-throughput, ideally allowing thousands of proteins to be identified on a time scale of hours. Most strategies of identification by MS rely on the analysis of enzymatically produced peptides originating from an isolated protein followed by either peptide mapping or tandem MS (MS/MS) to obtain sequence information for a single peptide, In the case of peptide mapping, several peptide masses are needed to unambiguously identify a protein with the typically achieved mass measurement accuracies (MMA). The ability to identify proteins based on the mass of a single peptide (i,e., an accurate mass tag; AMT) is proposed and is largely dependent on the MMA that can be achieved. To determine the MMA necessary to enable the use of AMTs for proteome-wide protein identification, we analyzed the predicted proteins and their tryptic fragments from Saccharomyces cerevisiae and Caenorhabditis elegans, The results show that low ppm (i,e,, similar to 1 ppm) level measurements have practical utility for analysis of small proteomes, Additionally, up to 85% of the peptides predicted from these organisms can function as AMTs at sub-ppm MMA levels attainable using Fourier transform ion cyclotron resonance MS. Additional information, such as sequence constraints, should enable even more complex proteomes to be studied at more modest mass measurement accuracies. Once AMTs are established, subsequent high-throughput measurements of proteomes (e,g,, after perturbations) will be greatly facilitated. C1 Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA81654] NR 25 TC 218 Z9 225 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUL 15 PY 2000 VL 72 IS 14 BP 3349 EP 3354 DI 10.1021/ac0002386 PG 6 WC Chemistry, Analytical SC Chemistry GA 337FQ UT WOS:000088347100051 PM 10939410 ER PT J AU Ma, LJ Gong, XY Yeung, ES AF Ma, LJ Gong, XY Yeung, ES TI Combinatorial screening of enzyme activity by using multiplexed capillary electrophoresis SO ANALYTICAL CHEMISTRY LA English DT Article ID LACTATE-DEHYDROGENASE ISOENZYMES; ZONE-ELECTROPHORESIS; ARRAYS AB Efficient and comprehensive screening of enzyme activity was accomplished in a combinatorial away of 96 reaction microvials. Quantitation of the extent of the reaction at web-defined time intervals was achieved by using 96-capillary array electrophoresis coupled with a multiplexed absorption detector. Capillary electrophoresis provides high separation resolution to isolate the product from the reactants. Absorption detection provides universal applicability to combinatorial screening. For the conversion of NADH to NAD(+), the catalytic activity of LDH was confirmed to be the highest at pH 7. This scheme should be useful for high-throughput drug discovery, clinical diagnosis, substrate binding, as well as combinatorial synthesis. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 17 TC 48 Z9 49 U1 0 U2 2 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 JUL 15 PY 2000 VL 72 IS 14 BP 3383 EP 3387 DI 10.1021/ac000145o PG 5 WC Chemistry, Analytical SC Chemistry GA 337FQ UT WOS:000088347100058 PM 10939417 ER PT J AU Merdink, JL Bull, RJ Schultz, IR AF Merdink, JL Bull, RJ Schultz, IR TI Trapping and identification of the dichloroacetate radical from the reductive dehalogenation of trichloroacetate by mouse and rat liver microsomes SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Article DE trichloroethylene; dichloroacetate; trichloroacetate; microsomes; free radical ID MALE B6C3F1 MOUSE; MASS-SPECTROSCOPY; CHLORAL HYDRATE; SPIN ADDUCTS; LIPID-PEROXIDATION; GC MS; TRICHLOROETHYLENE; METABOLISM; ACID; MICE AB A key question in the risk assessment of trichloroethylene (TRI) is the extent to which its carcinogenic effects might depend on the formation of dichloroacetate (DCA) as a metabolite. One of the metabolic pathways proposed for the formation of DCA from TRI is by the reductive dehalogenation of trichloroacetate (TCA), via a free radical intermediate. Although proof of this radical has been elusive, the detection of fully dechlorinated metabolites in the urine and the formation of lipid peroxidation by-products in microsomal incubations with TCA argue for its existence. We report here the trapping of the dichloroacetate radical with the spin-trapping agent PBN, and its identification by GC/MS. The PBN/dichloroacetate radical adduct was found to undergo an intramolecular rearrangement during its extraction into organic solvent. An internal condensation reaction between the acetate and the nitroxide radical moieties is hypothesized to form a cyclic adduct with the elimination of an OH radical. The PBN/dichloroacetate radical adduct has been identified by GC/MS in both a chemical Fenton system and in rodent microsomal incubations with TCA as substrate. (C) 2000 Elsevier Science Inc. C1 Washington State Univ, Grad Program Pharmacol & Toxicol, Pullman, WA 99164 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Merdink, JL (reprint author), POB 1441, Sherwood, OR 97140 USA. NR 27 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PD JUL 15 PY 2000 VL 29 IS 2 BP 125 EP 130 DI 10.1016/S0891-5849(00)00330-0 PG 6 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 353BX UT WOS:000089254800004 PM 10980401 ER PT J AU Wu, M Rinchik, EM Johnson, DK AF Wu, M Rinchik, EM Johnson, DK TI An integrated deletion and physical map encompassing l71Rl, a chromosome 7 locus required for peri-implantation survival in the mouse SO GENOMICS LA English DT Article ID DILUTION P LOCUS; GERM LINE; MUTATIONS; MICE; EMBRYO; GENE AB l71Rl, a locus that maps just proximal to the pink-eyed dilution (p) locus in mouse chromosome 7, was initially identified as being required for early post-implantation survival. We define further the null phenotype of l71Rl as peri-implantation lethal, with homozygous mutant embryos degenerating between embryonic day 4.5 (E4.5) and E5.5. We constructed an integrated deletion/physical map covering a 1.82-Mb chromosomal segment extending proximally from p. This map defines the minimum critical interval for l71Rl as an 80- to 300-kb region. This sequence-ready deletion/physical map should enable the cloning and characterization of the l71Rl gene(s). (C) 2000 Academic Press. C1 Univ Tennessee, Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Oak Ridge Natl Lab, Grad Sch Biomed Sci, Oak Ridge, TN 37831 USA. RP Johnson, DK (reprint author), Univ Tennessee, Oak Ridge Natl Lab, Div Life Sci, POB 2009, Oak Ridge, TN 37831 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD JUL 15 PY 2000 VL 67 IS 2 BP 228 EP 231 DI 10.1006/geno.2000.6236 PG 4 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 339JQ UT WOS:000088474300013 PM 10903848 ER PT J AU Govindasamy, B Caldeira, K AF Govindasamy, B Caldeira, K TI Geoengineering Earth's radiation balance to mitigate CO2-induced climate change SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC CO2 AB To counteract anthropogenic climate change, several schemes have been proposed to diminish solar radiation incident on Earth's surface. These geo-engineering schemes could reverse global annual mean warming; however, it is unclear to what extent they would mitigate regional and seasonal climate change, because radiative forcing from greenhouse gases such as CO2 differs from that of sunlight. No previous study has directly addressed this issue. In the NCAR CCM3 atmospheric general circulation model, we reduced the solar luminosity to balance the increased radiative forcing from doubling atmospheric CO2. Our results indicate that geo-engineering schemes could markedly diminish regional and seasonal climate change from increased atmospheric CO2, despite differences in radiative forcing patterns. Nevertheless, geo-engineering schemes could prove environmentally risky. C1 Univ Calif Lawrence Livermore Natl Lab, Climate & Carbon Cycle Grp, Livermore, CA 94550 USA. RP Govindasamy, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Climate & Carbon Cycle Grp, 700 East Ave,L-103, Livermore, CA 94550 USA. RI Caldeira, Ken/E-7914-2011 NR 19 TC 118 Z9 120 U1 6 U2 53 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 JUL 15 PY 2000 VL 27 IS 14 BP 2141 EP 2144 DI 10.1029/1999GL006086 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 337AQ UT WOS:000088335500032 ER PT J AU Le, G Chi, PJ Goedecke, W Russell, CT Szabo, A Petrinec, SM Angelopoulos, V Reeves, GD Chun, FK AF Le, G Chi, PJ Goedecke, W Russell, CT Szabo, A Petrinec, SM Angelopoulos, V Reeves, GD Chun, FK TI Magnetosphere on May 11, 1999, the day the solar wind almost disappeared: II. Magnetic pulsations in space and on the ground SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTHS FORESHOCK; ORIENTATION; WAVES AB Simultaneous observation's by Wind and IMP-8 in the upstream region on May 11, 1999, when the solar wind density was well below its usual values and the IMF was generally weakly northward, indicate there were upstream waves present in the foreshock, but wave power was an order of magnitude weaker than usual due to an extremely weak bow shock and tenuous solar wind plasma. Magnetic pulsations in the magnetosphere have been observed in the magnetic field data from Polar and at mid-latitude ground stations. By comparing May 11 with a control day under normal solar wind conditions and with a similar foreshock geometry, we find that the magnetosphere was much quieter than usual. The Pc 3-4 waves were nearly absent in the dayside magnetosphere both at Polar and as seen at midlatitude ground stations even through the foreshock geometry was favorable for the generation of these waves. Since the solar wind speed was not unusual on this day, these observations suggest that it is the Mach number of the solar wind flow relative to the magnetosphere that controls the amplitude of Pc 3-4 waves in the magnetosphere. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. Lockheed Martin Adv Ctr, Space Phys Lab, Palo Alto, CA 94304 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Le, G (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RI Le, Guan/C-9524-2012; Reeves, Geoffrey/E-8101-2011; OI Le, Guan/0000-0002-9504-5214; Reeves, Geoffrey/0000-0002-7985-8098; Russell, Christopher/0000-0003-1639-8298 NR 17 TC 12 Z9 13 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 JUL 15 PY 2000 VL 27 IS 14 BP 2165 EP 2168 DI 10.1029/1999GL000012 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 337AQ UT WOS:000088335500038 ER PT J AU Viecelli, JA Ree, FH AF Viecelli, JA Ree, FH TI Carbon particle phase transformation kinetics in detonation waves SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SOLID-LIQUID TRANSITION; STATISTICAL THERMODYNAMICS; MELTING TEMPERATURE; ORIENTED GRAPHITE; ELEMENTAL CARBON; CLUSTER; DIAMOND; DIAGRAM AB A much simplified model of nonequilibrium soot phase mixture kinetics is derived for use in hydrodynamic computation. This model is based on a review of existing shock and detonation soot recovery experiments as well as the available data on the carbon phase diagram. It yields a time and pressure-temperature path dependent value for the nonequilibrium diamond fraction of the soot mixture. Approximate methods for computing the detonation products pressure for the kinetics derived mixture of diamond and graphite are discussed. The proposed model increase in hydrodynamic computation cost is negligible. (C) 2000 American Institute of Physics. [S0021-8979(00)06914-0]. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM viecelli1@llnl.gov NR 37 TC 35 Z9 37 U1 0 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 2000 VL 88 IS 2 BP 683 EP 690 AR PII [S0021-8979(00)06914-0] DI 10.1063/1.373721 PG 8 WC Physics, Applied SC Physics GA 329DA UT WOS:000087889800013 ER PT J AU Liu, R Tonjes, WC Olson, CG Joyce, JJ Arko, AJ Neumeier, JJ Mitchell, JF Zheng, H AF Liu, R Tonjes, WC Olson, CG Joyce, JJ Arko, AJ Neumeier, JJ Mitchell, JF Zheng, H TI The electronic structure of La0.66Ca0.33MnO3 and La1.2Sr1.8Mn2O7 studied by angle resolved photoemission SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID VALENCE-BAND STRUCTURE; COLOSSAL-MAGNETORESISTANCE; LAYERED LA1.2SR1.8MN2O7; T-C; LA1-XCAXMNO3; LA1-XSRXMNO3; TRANSITION; PHASE; RESISTIVITY; PEROVSKITES AB We report angle resolved photoemission studies of La0.66Ca0.33MnO3 and La1.2Sr1.8Mn2O7 using single crystal samples. The Mn 3p-3d resonance photoemission data of La0.66Ca0.33MnO3 show that the states at 2.5 eV binding energy have predominantly Mn 3d character, qualitatively consistent with the predictions of local spin density approximation calculations except for a 1 eV shift toward higher binding energy. Band dispersions are observed in the normal emission data. The spectra of La1.2Sr1.8Mn2O7 show well defined features and strong matrix element effects, indicating excellent surface quality. (C) 2000 American Institute of Physics. [S0021-8979(00)01114-2]. C1 Michigan State Univ, Dept Phys, E Lansing, MI 48824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ames Lab, Ames, IA 50011 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Liu, R (reprint author), Michigan State Univ, Dept Phys, E Lansing, MI 48824 USA. NR 31 TC 7 Z9 7 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 2000 VL 88 IS 2 BP 786 EP 789 DI 10.1063/1.373737 PG 4 WC Physics, Applied SC Physics GA 329DA UT WOS:000087889800031 ER PT J AU Vavassori, P Donzelli, O Metlushko, V Grimsditch, M Ilic, B Neuzil, P Kumar, R AF Vavassori, P Donzelli, O Metlushko, V Grimsditch, M Ilic, B Neuzil, P Kumar, R TI Magnetic switching in submicron-scale periodic magnetic arrays SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERFEROMETRIC LITHOGRAPHY; INTERFERENCE LITHOGRAPHY; FLUX PENETRATION; PARTICLE ARRAY; REGULAR ARRAY; SUPERCONDUCTOR; PHOTORESIST; VALVE; DOTS AB The influence of the element shape on the switching of the magnetization in dot arrays has been investigated using a joint in-field magnetic force microscopy analysis and magneto-optical Kerr measurements. The single- or multiple-domain nature of the magnetization at remanence is shown to depend strongly on the aspect ratio of the elements and on how rounded or pointed each element is. (C) 2000 American Institute of Physics. [S0021-8979(00)07514-9]. C1 Univ Ferrara, Dipartmento Fis, INFM, I-44100 Ferrara, Italy. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Cornell Univ, Sch Appl & Engn Phys, Ithaca, NY 14853 USA. Inst Microelect, Singapore 117685, Singapore. RP Vavassori, P (reprint author), Univ Ferrara, Dipartmento Fis, INFM, Via Paradiso 12, I-44100 Ferrara, Italy. RI Neuzil, Pavel/B-9981-2012; Ilic, Rob/N-1359-2014; Vavassori, Paolo/B-4299-2014 OI Vavassori, Paolo/0000-0002-4735-6640 NR 26 TC 20 Z9 20 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 15 PY 2000 VL 88 IS 2 BP 999 EP 1003 AR PII [S0021-8979(00)07514-9] DI 10.1063/1.373768 PG 5 WC Physics, Applied SC Physics GA 329DA UT WOS:000087889800063 ER PT J AU Jerschow, A AF Jerschow, A TI Nonideal rotations in nuclear magnetic resonance: Estimation of coherence transfer leakage SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PULSED-FIELD GRADIENTS; INTEGER QUADRUPOLAR NUCLEI; SIDE-BAND SEPARATION; HIGH-RESOLUTION NMR; ANGLE-SPINNING NMR; TRANSFER SELECTION; TRANSFER PATHWAYS; SIGNAL SELECTION; SEQUENCE; SPECTROSCOPY AB When spherical tensors are rotated by certain angles, coherence transfer selection rules may apply. For example, a pi rotation cleanly inverts the coherence order. A pi/2 rotation of a T-0(1) tensor creates only T-+/- 1(1) tensors. In this work estimations are given for the coherence transfer leakage under the action of rotations with small errors in the rotation angle or axis. Although the theory is stated with particular applications to NMR (nuclear magnetic resonance) in mind it is equally applicable wherever nonideal rotations of spherical tensors are considered (e.g., quantum computing and relaxation theory). In NMR it is useful for the estimation of coherence transfer leakage, especially in pulse sequences with many n pi pulses. The results are also applicable to spinors and half-integer representations of the rotation group. (C) 2000 American Institute of Physics. [S0021-9606(00)00227-0]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Jerschow, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 11-D62, Berkeley, CA 94720 USA. OI Jerschow, Alexej/0000-0003-1521-9219 NR 24 TC 7 Z9 7 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 15 PY 2000 VL 113 IS 3 BP 979 EP 986 DI 10.1063/1.481878 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 331MH UT WOS:000088022500011 ER PT J AU Carr, A Biggin, MD AF Carr, A Biggin, MD TI Accessibility of transcriptionally inactive genes is specifically reduced at homeoprotein-DNA binding sites in Drosophila SO NUCLEIC ACIDS RESEARCH LA English DT Article ID CHROMATIN-REMODELING FACTOR; HOMEODOMAIN PROTEINS; IN-VIVO; PAIRED DOMAIN; EMBRYOS; HOX; SEGMENTATION; RECOGNITION; REPRESSION; EVOLUTION AB We showed previously that homeoproteins bind to multiple DNA sites throughout the length of most genes in Drosophila embryos. Based on a comparison of in vivo and in vitro DNA binding specificities, we suggested that homeoprotein binding sites on actively transcribed genes are largely accessible, whereas the binding of homeoproteins to inactive and poorly transcribed genes may be significantly inhibited at most sites, perhaps by chromatin structure. To test this model, we have measured the accessibility of restriction enzyme sites in a number of genes in isolated nuclei. Surprisingly, our data indicate that there is no difference in the overall accessibility of sites for several restriction enzymes on active versus inactive genes. However, consistent with our model, restriction enzyme recognition sequences that overlap with homeoprotein binding sites are less accessible on inactive genes than they are on active genes. We propose that transcriptional activation in all animals may involve a localized increase in accessibility at the AT-rich regions bound by homeoproteins and perhaps at a few other regions, rather than a generalized effect on all sites throughout a gene. C1 Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. RP Biggin, MD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd,Mailstop 84-171, Berkeley, CA 94720 USA. NR 45 TC 11 Z9 11 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUL 15 PY 2000 VL 28 IS 14 BP 2839 EP + DI 10.1093/nar/28.14.2839 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 338PB UT WOS:000088427500028 PM 10908343 ER PT J AU Phuoc, TX White, CM AF Phuoc, TX White, CM TI Experimental studies of the absorption and emissions from laser-induced spark in combustible gases SO OPTICS COMMUNICATIONS LA English DT Article ID IGNITION; MIXTURES AB This paper reports preliminary results of experimental measurements of the emission and absorption of laser-induced spark in air, O-2, N-2, H-2, and CH4 using a Q-switched Nd-Yag laser operating at 532 nm and 1064 nm, with a pulse duration of 5.5 ns. Line radiation spectra observed for spark in air consist of N and O lines that are distinctly observed in the region from 399.49 to 870.2 nm. The spectra of spark created in CH4 show strong H Lines centered at 656.46 nm. Some rather weak emission lines are also observed at 460.4, 497.0, 497.3, and 503.7 nm. Laser wavelength has a strong effect on the absorption data obtained as a function of total laser energy E-o. However, in case of variable pressure, its effect is considered to be within experimental fluctuations. Published by Elsevier Science B.V. C1 Natl Energy Technol Labs, Pittsburgh, PA 15236 USA. RP Phuoc, TX (reprint author), Natl Energy Technol Labs, POB 10940,MS 84-340, Pittsburgh, PA 15236 USA. NR 7 TC 24 Z9 24 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JUL 15 PY 2000 VL 181 IS 4-6 BP 353 EP 359 DI 10.1016/S0030-4018(00)00770-7 PG 7 WC Optics SC Optics GA 336CK UT WOS:000088284200017 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Theory of the negative isotope effect on copper in underdoped YBCO SO PHYSICA C LA English DT Article DE negative isotope; copper; YBCO ID HIGH-TEMPERATURE SUPERCONDUCTORS; SADDLE-POINT SINGULARITY; ORDER-PARAMETER; YBA2CU3O7; PHONONS; IMPURITIES; PARITY; OXYGEN; STATE AB An explanation is proposed of the negative isotope effect observed on copper in underdoped YBa2Cu3O7-delta. Calculations show that such an effect can be due to scattering of electrons from low-frequency phonons, which are not associated with oscillations of the total ionic charge density. The negative isotope effect is specific for superconducting layered curates with a d-wave order parameter and is absent in s-type superconductors of the same kind. Although the theory does not reproduce all observed features of the dependence of the isotope effect on oxygen concentration, it agrees qualitatively with the general trend of enhancement with decreasing T-c. A discussion is presented, and several possible experiments are proposed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Abrikosov, AA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 16 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUL 15 PY 2000 VL 336 IS 3-4 BP 163 EP 169 DI 10.1016/S0921-4534(00)00280-X PG 7 WC Physics, Applied SC Physics GA 336AR UT WOS:000088280200001 ER PT J AU Schnitzer, HJ Mertens, FG Bishop, AR AF Schnitzer, HJ Mertens, FG Bishop, AR TI A collective-variable theory for nonlinear coherent excitations in classical Hamiltonian systems SO PHYSICA D LA English DT Article DE collective variable; coherent excitation; constrained Hamiltonian system; Dirac bracket; canonical transformation ID SINE-GORDON SOLITONS; MAGNETIC VORTICES; STATISTICAL-MECHANICS; DILUTE GAS; DYNAMICS; KINK; MOTION; EQUATIONS; LATTICE; MODEL AB We derive a collective-variable theory for nonlinear coherent excitations that is based on Dirac's formalism of constrained Hamiltonian systems. No approximations are involved in this theory in the sense that we are able to formulate equations of motion for a new set of variables, including the collective variables themselves, which are equivalent to the original set of Hamilton's equation of motion. We show that the dynamics of collective excitations has to be classified according to the rank of the so-called gyromatrix. Two extreme cases are particularly important: in the first case (zero gyromatrix) collective excitations behave very much like Newtonian particles of classical mechanics, while in the second case (regular gyromatrix) collective excitations are similar to charged, massless particles in an external magnetic field. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Bayreuth, Inst Phys, D-95440 Bayreuth, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mertens, FG (reprint author), Univ Bayreuth, Inst Phys, POB 101251, D-95440 Bayreuth, Germany. NR 40 TC 14 Z9 14 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 JUL 15 PY 2000 VL 141 IS 3-4 BP 261 EP 280 DI 10.1016/S0167-2789(00)00041-5 PG 20 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 320QE UT WOS:000087411200007 ER PT J AU Cheong, HM Mascarenhas, A Geisz, JF Olson, JM AF Cheong, HM Mascarenhas, A Geisz, JF Olson, JM TI Resonant Raman scattering in spontaneously ordered GaInP2 SO PHYSICAL REVIEW B LA English DT Article ID LONG-RANGE-ORDER; SEMICONDUCTOR ALLOYS; PHONON MODES; GA0.52IN0.48P; GAXIN1-XP; PHOTOLUMINESCENCE; SUPERLATTICES; SPECTRA; GAAS AB We present resonant Raman scattering (RRS) studies on single-variant, spontaneously ordered GaInP2 alloys in backscattering geometries on the (001) growth surface and on a (110) cleaved surface. A systematic study of RRS in the (110) backscattering geometry enables us to resolve the controversy regarding the assignment of the ordering-induced phonon mode at 205 cm(-1) in this scattering geometry, and shows that this phonon mode is a forbidden longitudinal mode in this geometry but appears in the Raman spectra due to Frohlich scattering. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Cheong, HM (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 NR 24 TC 4 Z9 5 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 JUL 15 PY 2000 VL 62 IS 3 BP 1536 EP 1539 DI 10.1103/PhysRevB.62.1536 PG 4 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600017 ER PT J AU Teo, KL Kwok, SH Yu, PY Guha, S AF Teo, KL Kwok, SH Yu, PY Guha, S TI Quantum confinement of quasi-two-dimensional E-1 excitons in Ge nanocrystals studied by resonant Raman scattering SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-PHONON INTERACTIONS; SI NANOCRYSTALS; VISIBLE PHOTOLUMINESCENCE; OPTICAL GAPS; DOTS; LUMINESCENCE; SILICON AB Ge nanocrystals of diameters ranging from 4 to 10 nm were synthesized by ion implantation of Ge+ ions into SiO2 films followed by annealing. Confinement of its optical phonon and of the quasi-two-dimensional E-1 exciton have been observed at room temperature by resonant Raman scattering. The observed size-dependent blueshifts of the E-1 excitons energy (which can be larger than 0.7 eV) are found to be in good agreement with a theoretical calculation based on the effective mass approximation. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. USN, Res Lab, Div Mat Sci & Technol, Washington, DC 20375 USA. RP Teo, KL (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM PYYU@lbl.gov RI Teo, Kie Leong/B-1921-2008; OI Teo, Kie Leong/0000-0001-5073-4510 NR 30 TC 61 Z9 61 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 JUL 15 PY 2000 VL 62 IS 3 BP 1584 EP 1587 DI 10.1103/PhysRevB.62.1584 PG 4 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600029 ER PT J AU Nabighian, E Bartelt, MC Zhu, XD AF Nabighian, E Bartelt, MC Zhu, XD TI Kinetic roughening during rare-gas homoepitaxy SO PHYSICAL REVIEW B LA English DT Article ID LAYER GROWTH; ADSORPTION; AG(111); XE; XENON; TRANSITION; PT(111); INCOMMENSURATE; COMMENSURATE; DIFFRACTION AB Using an optical-reflectivity-difference technique, we monitored the growth of multilayer Xe films on a commensurate monolayer of Xe on Ni(111) from 35 to 60 K. A transition occurs near 40 K from rough growth at low temperature to quasi-layer-by-layer growth characterized by persistent oscillations in the reflectivity difference. We discuss this transition in terms of changes in the island formation process and the onset of second-layer nucleation. The Xe sticking coefficient at 40 K is obtained from the period of the oscillations in the reflectivity difference. We find that the sticking coefficient decreases with increasing film thickness at fixed Xe pressure. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Zhu, XD (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. EM xdzhu@physics.ucdavis.edu NR 24 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 JUL 15 PY 2000 VL 62 IS 3 BP 1619 EP 1622 DI 10.1103/PhysRevB.62.1619 PG 4 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600038 ER PT J AU Lee, G Plummer, EW AF Lee, G Plummer, EW TI Covalent interaction of H with the d electrons at the (111) surface of Ag SO PHYSICAL REVIEW B LA English DT Article ID METAL-SURFACES; ATOMIC-HYDROGEN; AG(111) SURFACE; CHEMISORPTION; PHOTOEMISSION; ADSORPTION; PD(111) AB The interaction of H with the Ag(111) surface has been investigated using angle-resolved-photoemission spectroscopy with synchrotron radiation. The bonding and antibonding states of a covalent interaction of Ag 4d bands with the H 1s level are clearly observed. The occupation of the antibonding state accounts for the low chemisorption energy of H on the Ag(111) surface. C1 Korea Res Inst Stand & Sci, Mat Evaluat Ctr, Taejon 305600, South Korea. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Lee, G (reprint author), Korea Res Inst Stand & Sci, Mat Evaluat Ctr, Taejon 305600, South Korea. NR 26 TC 12 Z9 12 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 2000 VL 62 IS 3 BP 1651 EP 1654 DI 10.1103/PhysRevB.62.1651 PG 4 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600046 ER PT J AU Jaffe, JE Snyder, JA Lin, ZJ Hess, AC AF Jaffe, JE Snyder, JA Lin, ZJ Hess, AC TI LDA and GGA calculations for high-pressure phase transitions in ZnO and MgO SO PHYSICAL REVIEW B LA English DT Article ID LOCAL-SPIN-DENSITY; GENERALIZED-GRADIENT-APPROXIMATION; ELECTRONIC-STRUCTURE CALCULATIONS; SEMICONDUCTORS; STABILITY; STATE; EQUATIONS; SYSTEMS; ENERGY; FE AB We report total energy and electronic structure calculations for ZnO in the B4 (wurtzite), B3 (zinc blende), B1 (rocksalt), and B2 (CsCl) crystal structures over a range of unit cell volumes. We employed both the local-density approximation (LDA) and the PBE96 form of the generalized gradient approximation (GGA) together with optimized Gaussian basis sets to expand the crystal orbitals and periodic electron density. In agreement with earlier ab initio calculations and with experiment, we find that the B4 phase of ZnO is slightly lower in energy than the B3 phase, and that it transforms first to the B1 structure under applied pressure. The equilibrium transition pressure p(T1) is 6.6 GPa at the LDA level of theory and 9.3 GPa in the GGA, compared to experimental values around 9 GPa. This confirms a trend seen by other workers in which the LDA underestimates structural transition pressures which are more accurately predicted by the GGA. At much higher compression, we predict that the B1 phase of ZnO will transform to the B2 (cesium chloride) structure at p(T2)=260 GPa (LDA) or 256 GPa (GGA) indicating that gradient corrections are small for this material at megabar pressures. This is the first quantitative prediction of this transition in ZnO, and should be testable with diamond-anvil techniques. We predict that ZnO remains a semiconductor up to p(T2). For comparison we find that the B1 to B2 transition in MgO occurs at 515 GPa with either LDA or GGA, in excellent agreement with other ab initio predictions. C1 Pacific NW Lab, Dept Mat Sci, Richland, WA 99352 USA. RP Jaffe, JE (reprint author), Pacific NW Lab, Dept Mat Sci, Richland, WA 99352 USA. RI Lin, Zijing/D-4050-2009 NR 36 TC 279 Z9 297 U1 8 U2 63 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 JUL 15 PY 2000 VL 62 IS 3 BP 1660 EP 1665 DI 10.1103/PhysRevB.62.1660 PG 6 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600048 ER PT J AU Fattebert, JL Bernholc, J AF Fattebert, JL Bernholc, J TI Towards grid-based O(N) density-functional theory methods: Optimized nonorthogonal orbitals and multigrid acceleration SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; MOLECULAR-DYNAMICS SIMULATIONS; FINITE-ELEMENT APPROACH; SYSTEM-SIZE; LOCALIZED ORBITALS; SCALING ALGORITHM; CARBON NANOTUBES; MATRIX METHOD; DIFFERENCE; COMPUTATIONS AB We have formulated and implemented a real-space ab initio method for electronic structure calculations in terms of nonorthogonal orbitals defined on a grid. A multigrid preconditioner is used to improve the steepest descent directions used in the iterative minimization of the energy functional. Unoccupied or partially occupied states are included using a density matrix formalism in the subspace spanned by the nonorthogonal orbitals. The freedom introduced by the nonorthogonal real-space description of the orbitals allows for localization constraints that linearize the cost of the most expensive parts of the calculations, while keeping a fast convergence rate for the iterative minimization with multigrid acceleration. Numerical tests for carbon nanotubes show that very accurate results can be obtained for localization regions with radii of 8 bohr. This approach, which substantially reduces the computational cost for very large systems, has been implemented on the massively parallel Gray T3E computer and tested on carbon nanotubes containing more than 1000 atoms. C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. RP CASC, Univ Calif Lawrence Livermore Natl Lab, L-551, Livermore, CA 94551 USA. NR 62 TC 128 Z9 129 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 2000 VL 62 IS 3 BP 1713 EP 1722 DI 10.1103/PhysRevB.62.1713 PG 10 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600054 ER PT J AU Arko, AJ Joyce, JJ Morales, L Wills, J Lashley, J Wastin, F Rebizant, J AF Arko, AJ Joyce, JJ Morales, L Wills, J Lashley, J Wastin, F Rebizant, J TI Electronic structure of alpha- and delta-Pu from photoelectron spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; PERIODIC ANDERSON MODEL; HEAVY FERMIONS; 5F ELECTRONS; A-PU; LOCALIZATION; SYSTEMS; SURFACE AB We report photoemission results on alpha- and delta-Pu using a laser plasma light source (LPLS) as well as He light as the exciting radiation. The LPLS isa pseudocontinuum tunable Light source with intensities rivaling some second-generation synchrotrons. Both phases of Pu display a narrow, temperature-independent, 5f-related feature at the Fermi energy, which is narrower in delta-Pu than in alpha-Pu, suggestive of possible heavy-fermion-like behavior. In both alpha-Pu and delta-Pu the photon-energy dependence of this feature suggests some 6d admixture, albeit somewhat smaller in delta-Pu. In this respect it differs qualitatively from Ce and U heavy fermions. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. European Commiss, Joint Res Ctr, Inst Transuran Elements, D-76175 Karlsruhe, Germany. RP Arko, AJ (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 40 TC 119 Z9 119 U1 2 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 JUL 15 PY 2000 VL 62 IS 3 BP 1773 EP 1779 DI 10.1103/PhysRevB.62.1773 PG 7 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600061 ER PT J AU Wang, LG Kratzer, P Moll, N Scheffler, M AF Wang, LG Kratzer, P Moll, N Scheffler, M TI Size, shape, and stability of InAs quantum dots on the GaAs(001) substrate SO PHYSICAL REVIEW B LA English DT Article ID HIGHLY MISMATCHED HETEROEPITAXY; ENERGY ELECTRON-DIFFRACTION; STRAINED ISLANDS; MOLECULAR-DYNAMICS; LATTICE-MISMATCH; COHERENT ISLANDS; FIRST PRINCIPLES; GAAS-SURFACES; GROWTH; TRANSITION AB We study the energetics of island formation in Stranski-Krastanow growth of highly mismatched heteroepitaxy within a parameter-free approach. It is shown that the (frequently found) rather narrow size distribution of the self-assembled coherent islands can be understood as the result of the system being trapped in a constrained equilibrium state with a fixed island density. If allowing for variations of the island density, we find that larger islands combined with a lower island density are more stable; this implies that Ostwald ripening will take place on time scales sufficiently long for exchange of atoms between different islands to occur. Moreover, we show how to select the island size by controlling the growth conditions and the amount of deposited material. Our study also indicates that the island shape depends on the island size, i.e., an island with larger volume has a higher value of the height-to-base ratio. C1 Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. RP Wang, LG (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Moll, Nikolaj/C-5674-2013; Kratzer, Peter/M-6132-2014; Scheffler, Matthias/O-4649-2016 OI Moll, Nikolaj/0000-0001-5645-4667; NR 65 TC 77 Z9 79 U1 1 U2 14 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 JUL 15 PY 2000 VL 62 IS 3 BP 1897 EP 1904 DI 10.1103/PhysRevB.62.1897 PG 8 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600079 ER PT J AU Smith, BA Zhang, JZ Joly, A Liu, J AF Smith, BA Zhang, JZ Joly, A Liu, J TI Luminescence decay kinetics of Mn2+-doped ZnS nanoclusters grown in reverse micelles SO PHYSICAL REVIEW B LA English DT Article ID EXCITED ELECTRONIC STATES; SEMICONDUCTOR CLUSTERS; PHOTOPHYSICAL PROPERTIES; OPTICAL-PROPERTIES; CDS CLUSTERS; NANOSIZED PARTICLES; PHOTO-LUMINESCENCE; DOPED NANOCRYSTALS; SOLID-SOLUTION; SIZE AB We report the synthesis and luminescence decay kinetics of 1.2-nm Mn2+-doped ZnS nanoclusters grown in reverse micelles. The preparation method produces small particles with narrow-size distribution and fluorescence bands near 400-450 nm and 585 nm. Time-dependent fluorescence decay measurements using picosecond, nanosecond, and millisecond techniques reveal relaxation processes on all three time scales. In the doped sample, the red emission detected at 600 nm exhibits a 1-2 ms decay in addition to faster decays with time constants on the order of hundreds of ps, a few ns and tens of mu s. While the slow decay is the same as that of bulk Mn2+-doped ZnS, the fast decays are present for both doped and undoped samples and are unique to nanocluster ZnS, which are attributed to deep trap-state emission. The blue luminescence near 400-450 nm is attributed to shallow trap-state emission of ZnS. These results help to resolve the controversy in the literature regarding the lifetime of the Mn2+ emission in Mn-doped ZnS nanoparticles. C1 Univ Calif Santa Cruz, Dept Chem, Santa Cruz, CA 95060 USA. Pacific NW Natl Lab, PNNL, Richland, WA 99352 USA. RP Smith, BA (reprint author), Univ Calif Santa Cruz, Dept Chem, Santa Cruz, CA 95060 USA. NR 48 TC 85 Z9 85 U1 3 U2 17 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 JUL 15 PY 2000 VL 62 IS 3 BP 2021 EP 2028 DI 10.1103/PhysRevB.62.2021 PG 8 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600094 ER PT J AU Liu, DJ Evans, JW AF Liu, DJ Evans, JW TI Ordering and percolation transitions for hard squares: Equilibrium versus nonequilibrium models for adsorbed layers with c(2x2) superlattice ordering SO PHYSICAL REVIEW B LA English DT Article ID RENORMALIZATION GROUP-APPROACH; MONTE-CARLO SIMULATIONS; LATTICE-GAS; SCALING PROPERTIES; PHASE-TRANSITIONS; SPIN SYSTEMS; ISING-MODELS; ALGORITHM; DIFFUSION; CLUSTERS AB We study the critical behavior of models for adsorbed layers in which particles reside on a square lattice and have infinite nearest-neighbor repulsions. Such particles are often described as "hard squares." We consider both the equilibrium hard-square model and a nonequilibrium model. The latter involves dimer adsorption onto diagonally adjacent sites, and the desorption and possible hopping of adsorbed monomer particles (where neither adsorption nor hopping can create adjacent pairs of occupied sites). In the limit or high monomer mobility, one recovers the equilibrium model. Both models exhibit a continuous symmetry breaking transition in the Ising universality class, and also a percolation transition for c(2x2) clusters of particles connected with diagonal bonds. For the equilibrium model, extensive Monte Carlo simulations show that the two transitions coincide, supporting the claim of Hu and Mak. We also determine percolation exponents for c(2x2) clusters and vacancy clusters, and consider a correlated site-bond percolation problem which elucidates conditions for coincidence of symmetry-breaking and percolation. In contrast, for the nonequilibrium model with immobile adsorbed monomers, there is a gap between the symmetry-breaking and percolation transitions, and the random percolation universality class applies. Finally, we examine the crossover behavior with increasing mobility of adsorbed monomers. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. RP Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 43 TC 11 Z9 11 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 2000 VL 62 IS 3 BP 2134 EP 2145 DI 10.1103/PhysRevB.62.2134 PG 12 WC Physics, Condensed Matter SC Physics GA 337AR UT WOS:000088335600109 ER PT J AU Fromer, NA Kner, P Chemla, DS Lovenich, R Schafer, W AF Fromer, NA Kner, P Chemla, DS Lovenich, R Schafer, W TI Correlation effects beyond Hartree-Fock theory and polarization dependence of four-wave mixing in bulk GaAs at high magnetic field SO PHYSICAL REVIEW B LA English DT Article ID EXCITON-EXCITON CORRELATIONS; NONLINEAR-OPTICAL REGIME; HEAVY-HOLE EXCITONS; QUANTUM-WELLS; 4-WAVE-MIXING SIGNALS; LIGHT-HOLE; COHERENT EMISSION; SEMICONDUCTORS; BEATS; OSCILLATIONS AB Combining Linear polarization excitation and magnetic-field breaking of chiral symmetry of optical transitions in Group-III-V semiconductors, we use resonant degenerate four-wave mixing to observe effects beyond the time-dependent Hartree-Fock theory that are not seen by other techniques. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Forschungszentrum, John von Neumann Inst Comp, D-52425 Julich, Germany. RP Fromer, NA (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 28 TC 7 Z9 7 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 JUL 15 PY 2000 VL 62 IS 4 BP 2516 EP 2521 DI 10.1103/PhysRevB.62.2516 PG 6 WC Physics, Condensed Matter SC Physics GA 341VT UT WOS:000088612200041 ER PT J AU Franceschetti, A Zunger, A AF Franceschetti, A Zunger, A TI Pseudopotential calculations of electron and hole addition spectra of InAs, InP, and Si quantum dots SO PHYSICAL REVIEW B LA English DT Article ID SMALL SEMICONDUCTOR CRYSTALLITES; MAGNETIC-FIELD; CAPACITANCE SPECTROSCOPY; DIELECTRIC CONFINEMENT; ARTIFICIAL ATOMS; COULOMB ISLAND; OPTICAL GAPS; HALL REGIME; NANOCRYSTALS; SILICON AB The electron and hole addition energies, the quasiparticle gap, and the optical gap of InAs, InP, and Si quantum dots an calculated using microscopic pseudopotential wave functions. The effects of the dielectric mismatch between the quantum dot and the surrounding material are included using a realistic profile for the dielectric constant epsilon(r). We find that the addition energies and the quasiparticle gap depend strongly on the dielectric constant of the environment epsilon(out), while the optical gap is rather insensitive to epsilon(out). We compare our results with recent tunneling spectroscopy measurements for InAs nanocrystals, finding excellent agreement. Our calculations for the addition energies and the quasiparticle gap of InP and Si nanocrystals serve as predictions for future experiments. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Franceschetti, A (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 46 TC 108 Z9 108 U1 2 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 2000 VL 62 IS 4 BP 2614 EP 2623 DI 10.1103/PhysRevB.62.2614 PG 10 WC Physics, Condensed Matter SC Physics GA 341VT UT WOS:000088612200052 ER PT J AU Sofo, JO Mahan, GD AF Sofo, JO Mahan, GD TI Diffusion and transport coefficients in synthetic opals SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-WELL SUPERLATTICES; THERMOELECTRIC FIGURE; MERIT; CONDUCTIVITY AB Opals are structures composed of close-packed spheres in the size range of nano to micrometers. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the thermal and electrical conductivity is used to estimate the transport coefficients of opal structures as a function of the neck size and the mean free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures. C1 Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 Bariloche, Rio Negro, Argentina. Comis Nacl Energia Atom, Inst Balseiro, RA-8400 Bariloche, Rio Negro, Argentina. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Sofo, JO (reprint author), Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 Bariloche, Rio Negro, Argentina. RI Sofo, Jorge/J-4415-2012; Sofo, Jorge/B-4344-2014 OI Sofo, Jorge/0000-0003-4513-3694; Sofo, Jorge/0000-0003-4513-3694 NR 21 TC 11 Z9 11 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 15 PY 2000 VL 62 IS 4 BP 2780 EP 2785 DI 10.1103/PhysRevB.62.2780 PG 6 WC Physics, Condensed Matter SC Physics GA 341VT UT WOS:000088612200070 ER PT J AU Lin, SY Fleming, JG Chow, E Bur, J Choi, KK Goldberg, A AF Lin, SY Fleming, JG Chow, E Bur, J Choi, KK Goldberg, A TI Enhancement and suppression of thermal emission by a three-dimensional photonic crystal SO PHYSICAL REVIEW B LA English DT Article ID INHIBITED SPONTANEOUS EMISSION; BAND-GAP STRUCTURES; PERIODIC STRUCTURES; OPAL AB The emission and detection of electromagnetic radiation are essential optical processes that govern performance of lasers, detectors and solar cells. Through light-photonic crystal interaction, a three-dimensional (3D) photonic crystal offers a way to alter such optical processes. Experimental realization is done by building a thin slab of 3D photonic crystal onto a silicon material. The 3D crystal structure is found to be highly effective in suppressing silicon thermal radiation in the photonic band gap spectral regime. Emission is also enhanced in the photonic passbands. At passband resonant frequencies, a thin slab of 3D photonic crystal actually acts like a planar blackbody. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. USA, Res Labs, Adelphi, MD 20783 USA. RP Lin, SY (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 22 TC 66 Z9 68 U1 2 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 JUL 15 PY 2000 VL 62 IS 4 BP R2243 EP R2246 DI 10.1103/PhysRevB.62.R2243 PG 4 WC Physics, Condensed Matter SC Physics GA 341VT UT WOS:000088612200001 ER PT J AU Reboredo, FA Zunger, A AF Reboredo, FA Zunger, A TI L-to-X crossover in the conduction-band minimum of Ge quantum dots SO PHYSICAL REVIEW B LA English DT Article ID OPTICAL-PROPERTIES; CONFINEMENT; NANOCRYSTALS AB Screened-pseudopotential calculations of large (less than or similar to 3000 atoms) surface-passivated Ce quantum dots show that below a critical dot diameter that depends on the passivant, the character of the lowest conduction state changes from an L-derived to an X-derived state. Thus, in this size regime, Ge dots are Si-like. This explains the absence, in a pseudopotential description, of a crossing between the band gaps of Si and Ge dots as a function of size, predicted earlier in single-valley effective-mass calculations. The predicted L-->X crossing suggests that small Ge dots will have an X-like, red shift of the band gap with applied pressure, as opposed to an L-like blue shift of large dots. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Reboredo, FA (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Reboredo, Fernando/B-8391-2009; Zunger, Alex/A-6733-2013 NR 11 TC 45 Z9 45 U1 2 U2 8 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 JUL 15 PY 2000 VL 62 IS 4 BP R2275 EP R2278 DI 10.1103/PhysRevB.62.R2275 PG 4 WC Physics, Condensed Matter SC Physics GA 341VT UT WOS:000088612200009 ER PT J AU Watanabe, M Itoh, KM Ootuka, Y Haller, EE AF Watanabe, M Itoh, KM Ootuka, Y Haller, EE TI Localization length and impurity dielectric susceptibility in the critical regime of the metal-insulator transition in homogeneously doped p-type Ge SO PHYSICAL REVIEW B LA English DT Article ID UNIAXIAL-STRESS; CONDUCTIVITY; GE-70-GA; TEMPERATURE; BEHAVIOR; SYSTEMS AB We have determined the localization length xi and the impunity dielectric susceptibility X-imp as a function of Ga acceptor concentrations (N) in nominally uncompensated Ge-70:Ga just below the critical concentration (N-c) for the metal-insulator transition. Both xi and X-imp diverge at N-c according to the functions xi proportional to(1 -N/N-c)(-v) and X(imp)proportional to(N-c/N-1)(-zeta) respectively, with v=1.2+/-0.3 and zeta=2.3+/-0.6 for 0.99N(c) 0) considerations. If p = 3, superpotentials for massless modes are forbidden to all orders in alpha' and may only be generated by open string instantons. For this latter case we find that such instanton effects are generically present. Mirror symmetry relates even and odd p and thus perturbative and nonperturbative superpotentials; we provide a preliminary discussion of a class of examples of such mirror pairs. C1 Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford, CA 94305 USA. Oklahoma State Univ, Dept Math, Stillwater, OK 74078 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. RP Inst Adv Study, Sch Nat Sci, Olden Lane, Princeton, NJ 08540 USA. OI Lawrence, Albion/0000-0003-4116-045X NR 49 TC 123 Z9 123 U1 2 U2 3 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 JUL 15 PY 2000 VL 62 IS 2 AR 026001 DI 10.1103/PhysRevD.62.026001 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 336WN UT WOS:000088326100080 ER PT J AU Balema, VP Pecharsky, AO Pecharsky, VK AF Balema, VP Pecharsky, AO Pecharsky, VK TI Concerning the transformations of Ti3Ir alloy during high-energy ball-milling SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE intermetallic compounds; mechanical alloying; phase transformations; hydrogen storage; superconductivity ID PHASE-TRANSFORMATION; COMPOUND TI3IR; HYDROGEN; V3GA AB Thermodynamically stable Ti3Ir with the Cr3Si (A15)-type crystal structure can gradually be transformed into a metastable Ti3Ir alloy with a bce crystal structure by high-energy ball-milling for 12.5 h. The long-term ball-milling for up to 112 h, however, is accompanied by a solid-state reaction between Ti3Ir and the vial material leading to the formation of a nano-crystalline or amorphous MgZn2-type phase with the Ti(Fe1.85Ir0.15) stoichiometry and a micro-crystalline thermodynamically stable CsCl-type phase. Both the CsCl- and MgZn2-type phases were obtained in the crystalline form after annealing ball-milled Ti3Ir. Properties of the A15 Ti3Ir alloy changed considerably after ball-milling. The superconducting transition observed in the original A15 alloy at similar to 4.3 K no longer exists in the ball-milled material. The electrochemically determined hydrogen storage capacity of the ball-milled alloy also decreases in comparison to the A15 material from 269 to 104 mAh/g. On the contrary, the electrochemical discharge capacity of Ti3Ir increases From 45 to 104 mAh/g after ball-milling. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Pecharsky, VK (reprint author), Iowa State Univ, Ames Lab, 242 Spedding Hall, Ames, IA 50011 USA. NR 17 TC 9 Z9 9 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUL 14 PY 2000 VL 307 BP 184 EP 190 DI 10.1016/S0925-8388(00)00886-0 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 341LB UT WOS:000088590900030 ER PT J AU Bada, M Walther, D Arcangioli, B Doniach, S Delarue, M AF Bada, M Walther, D Arcangioli, B Doniach, S Delarue, M TI Solution structural studies and low-resolution model of the Schizosaccharomyces pombe sap1 protein SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE DNA-protein interactions; low-resolution modelling; ultracentrifugation analysis; dynamic light-scattering; small angle X-ray scattering ID DYNAMIC LIGHT-SCATTERING; SMALL-ANGLE SCATTERING; X-RAY-SCATTERING; ANALYTICAL ULTRACENTRIFUGATION; MACROMOLECULAR ASSEMBLIES; BIOLOGICAL MACROMOLECULES; FISSION YEAST; DNA; PROGRAM; BINDING AB Sap1 is a DNA-binding protein involved in controlling the mating type switch in fission yeast Schizosaccharomyces pombe. In the absence of any significant sequence similarity with any structurally known protein, a variety of biophysical techniques has been used to probe the solution low-resolution structure of the sap1 protein. First, sap1 is demonstrated to be an unusually elongated dimer in solution by measuring the translational diffusion coefficient with two independent techniques: dynamic light-scattering and ultracentrifugation. Second, sequence analysis revealed the existence of a long coiled-coil region, which is responsible for dimerization. The length of the predicted coiled-coil matches estimates drawn from theh hydrodynamic experimental behavior of the molecule. In addition, the same measurements done on a shorter construct with a coiled-coil region shortened by roughly one-half confirmed the localization of the long coiled-coil region. A crude T-shape model incorporating all these information was built. Third, small-angle X-ray scattering (SAXS) of the fr molecule provided additional evidence for the model. In particular, the P(r) curve strikingly demonstrates the existence of long intramolecular distances. Using a novel 3D reconstruction algorithm, a low resolution 3D model of the protein has been independently constructed that matches the SAXS experimental data. It also fits the translation diffusion coefficients measurements and agrees with the first T-shaped model. This low-resolution model has clearly biologically relevant new functional implications, suggesting that sap1 is a bifunctional protein, with the two active sites being separated by as much as 120 Angstrom; a tetrapeptide repeated four times at the C terminus of the molecule is postulated to be of utmost functional importance. (C) 2000 Academic Press. C1 Inst Pasteur, Unite Biochim Struct, F-75015 Paris, France. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, SSRL, Stanford, CA 94305 USA. Incyte Pharmaceut, Palo Alto, CA 94306 USA. Inst Pasteur, Unite Virus Oncogenes, F-75015 Paris, France. RP Delarue, M (reprint author), Inst Pasteur, Unite Biochim Struct, 25 Rue Dr Roux, F-75015 Paris, France. OI Walther, Dirk/0000-0002-5755-9265 NR 35 TC 23 Z9 24 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 14 PY 2000 VL 300 IS 3 BP 563 EP 574 DI 10.1006/jmbi.2000.3854 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 335CC UT WOS:000088223600012 PM 10884352 ER PT J AU Yeh, AP Chatelet, C Soltis, SM Kuhn, P Meyer, J Rees, DC AF Yeh, AP Chatelet, C Soltis, SM Kuhn, P Meyer, J Rees, DC TI Structure of a thioredoxin-like [2Fe-2S] ferredoxin from Aquifex aeolicus SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE crystal structure; [2Fe-2S] ferredoxin; thioredoxin; respiratory chain; iron-sulfur clusters ID IRON-SULFUR CLUSTER; NADH-QUINONE OXIDOREDUCTASE; GLUTATHIONE-S-TRANSFERASE; RATIONAL PROTEIN DESIGN; 1.8 ANGSTROM RESOLUTION; AMINO-ACID-SEQUENCE; CLOSTRIDIUM-PASTEURIANUM; CRYSTAL-STRUCTURE; HYPERTHERMOPHILIC BACTERIUM; 3-DIMENSIONAL STRUCTURE AB The 2.3 Angstrom resolution crystal structure of a [2Fe-2S] cluster containing ferredoxin from Aquifex aeolicus reveals a thioredoxin-like fold that is novel among iron-sulfur proteins. The [2Fe-2S] cluster is located near the surface of the protein, at a site corresponding to that of the active-site disulfide bridge in thioredoxin. The four cysteine ligands are located near the ends of two surface loops. Two of these ligands can be substituted by non-native cysteine residues introduced throughout a stretch of the polypeptide chain that forms a protruding loop extending away from the cluster. The presence of homologs of this ferredoxin as components of more complex anaerobic and aerobic electron transfer systems indicates that this is a versatile fold for biological redox processes. (C) 2000 Academic Press. C1 CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CEA, Dept Biol Mol & Struct, F-38054 Grenoble, France. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. CALTECH, Howard Hughes Med Inst, Pasadena, CA 91125 USA. RP Meyer, J (reprint author), CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. NR 59 TC 41 Z9 43 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUL 14 PY 2000 VL 300 IS 3 BP 587 EP 595 DI 10.1006/jmbi.2000.3871 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 335CC UT WOS:000088223600014 PM 10884354 ER PT J AU LaGattuta, KJ AF LaGattuta, KJ TI Multiple ionization of argon atoms by long-wavelength laser radiation: a fermion molecular dynamics simulation SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID NONSEQUENTIAL DOUBLE-IONIZATION; HELIUM; FIELD AB We applied the method known as fermion molecular dynamics to the description of an isolated argon atom interacting with a shea pulse of intense, long-wavelength laser radiation, for both linear and circular polarization. We discuss the results of these calculations, insofar as they bear on the mechanisms leading to the production of high-ionic-charge states during laser-atom interaction. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP LaGattuta, KJ (reprint author), Univ Calif Los Alamos Natl Lab, MS-B259, Los Alamos, NM 87545 USA. NR 14 TC 5 Z9 5 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 JUL 14 PY 2000 VL 33 IS 13 BP 2489 EP 2494 DI 10.1088/0953-4075/33/13/309 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 340NJ UT WOS:000088540400013 ER PT J AU Diehl, S Cubaynes, D Zhou, HS VoKy, L Wuilleumier, FJ Kennedy, ET Bizau, JM Manson, ST Blancard, C Berrah, N Bozek, J AF Diehl, S Cubaynes, D Zhou, HS VoKy, L Wuilleumier, FJ Kennedy, ET Bizau, JM Manson, ST Blancard, C Berrah, N Bozek, J TI The 2p(3) triply excited hollow resonance of lithium: measurement and calculation of partial cross sections and angular behaviour SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID THEORETICAL CALCULATIONS; RYDBERG SERIES; ATOMIC LITHIUM; STATES; RESOLUTION; SPECTROSCOPY; COLLISIONS; HELIUM AB We have measured the partial cross sections and angle-resolved energy dependence of the electrons emitted over the energy range of the triply-excited 2p(3) P-2 hollow lithium resonance. We have also calculated the beta-behaviour using the R-matrix methodology. Experimental and theoretical results are in good agreement and show deep minima in the 1s2p(1,3)P ionic channels. C1 Univ Paris 11, Lab Spect Atom & Ion, CNRS, UMR 8624, F-91405 Orsay, France. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Observ Cote Azur, F-06304 Nice, France. Dublin City Univ, Sch Phys Sci, Natl Ctr Plasma Sci & Technol, Dublin 9, Ireland. Ctr CEA DAM, DPTA, F-91680 Bruyeres Le Chatel, France. Western Michigan Univ, Dept Phys, Kalamazoo, MI USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Diehl, S (reprint author), Univ Paris 06, Lab DIAM, 4 Pl Jussieu, F-75231 Paris, France. RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 24 TC 12 Z9 12 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JUL 14 PY 2000 VL 33 IS 13 BP L487 EP L494 DI 10.1088/0953-4075/33/13/103 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 340NJ UT WOS:000088540400003 ER PT J AU Moxom, J AF Moxom, J TI Multiple ionization of xenon by positron impact SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID NOBLE-GASES; SINGLE IONIZATION; KRYPTON; HELIUM; NEON AB New data for double, triple and quadruple ionization of Xe at impact energies up to 400 eV are presented. The contribution to the total triple ionization cross section from ionization with positronium formation, below the threshold for direct ionization, is Small (less than 1.6 +/- 0.2% of the triple ionization cross section maximum). By interpolating the present data for quadruple ionization, the relative contribution from quadruple ionization with positronium formation below the threshold for direct quadruple ionization, is indistinguishable from zero. These findings are in qualitative agreement with the model recently proposed by Humberston and Van Reeth. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Marquette Univ, Dept Chem, Milwaukee, WI 53201 USA. RP Moxom, J (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 13 TC 7 Z9 7 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JUL 14 PY 2000 VL 33 IS 13 BP L481 EP L485 DI 10.1088/0953-4075/33/13/102 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 340NJ UT WOS:000088540400002 ER PT J AU Chaudhuri, J Ignatiev, K Edgar, JH Xie, ZY Gao, Y Rek, Z AF Chaudhuri, J Ignatiev, K Edgar, JH Xie, ZY Gao, Y Rek, Z TI Low temperature chemical vapor deposition of 3C-SiC on 6H-SiC - high resolution X-ray diffractometry and synchrotron X-ray topography study SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE X-ray diffraction; synchrotron grazing incidence topography; synchrotron white beam X-ray topography; 3C-SiC; chemical vapour deposition; cellular dislocation structure; low angle grain boundary; micropores ID BETA-SIC FILMS AB Highly perfect 3C-SiC thin films, deposited on GH-SIC by the chemical vapor deposition at low temperature with various Cl/Si, H/Si and C/Si ratios, were characterized by X-ray high resolution triple crystal diffractometry, synchrotron white beam X-ray topography (SWBXT) and synchrotron grazing incidence topography (SGIT) methods. The films were epitaxial with a low defect density (mostly in the range of 10(7) cm(-2)). The best films were produced with optimum C/Si ratio in the gas phase while the poorest quality films were produced at lower H-2/Si ratio. Synchrotron topography revealed defects like cellular dislocation structure, super screw dislocations, pens, low angle grain boundaries and double positioning boundaries. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Wichita State Univ, Dept Mech Engn, Wichita, KS 67260 USA. Kansas State Univ, Dept Chem Engn, Manhattan, KS 66506 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94035 USA. RP Chaudhuri, J (reprint author), Wichita State Univ, Dept Mech Engn, Wichita, KS 67260 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 11 TC 7 Z9 8 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD JUL 14 PY 2000 VL 76 IS 3 BP 217 EP 224 DI 10.1016/S0921-5107(00)00451-7 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 326DX UT WOS:000087718400007 ER PT J AU Feng, DL Lu, DH Shen, KM Kim, C Eisaki, H Damascelli, A Yoshizaki, R Shimoyama, J Kishio, K Gu, GD Oh, S Andrus, A O'Donnell, J Eckstein, JN Shen, ZX AF Feng, DL Lu, DH Shen, KM Kim, C Eisaki, H Damascelli, A Yoshizaki, R Shimoyama, J Kishio, K Gu, GD Oh, S Andrus, A O'Donnell, J Eckstein, JN Shen, ZX TI Signature of superfluid density in the single-particle excitation spectrum of Bi2Sr2CaCu2O8+delta SO SCIENCE LA English DT Article ID T-C SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; PENETRATION-DEPTH; DOPING DEPENDENCE; TEMPERATURE; PHASE; STATE; YBA2CU3O6.95; FLUCTUATIONS; SUPPRESSION AB We report that the doping and temperature dependence of photoemission spectra near the Brillouin zone boundary of Bi2Sr2CaCu2O8+delta exhibit unexpected sensitivity to the superfluid density. In the superconducting state, the photoemission peak intensity as a function of doping scales with the superfluid density and the condensation energy. As a function of temperature, the peak intensity shows an abrupt behavior near the superconducting phase transition temperature where phase coherence sets in, rather than near the temperature where the gap opens. This anomalous manifestation of collective effects in single-particle spectroscopy raises important questions concerning the mechanism of high-temperature superconductivity. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Tsukuba, Inst Appl Phys, Tsukuba, Ibaraki 305, Japan. Univ Tokyo, Dept Appl Chem, Tokyo 1138656, Japan. Univ New S Wales, Sch Phys, Kensington, NSW 2033, Australia. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Feng, DL (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RI Shen, Kyle/B-3693-2008; damascelli, andrea/P-6329-2014 OI damascelli, andrea/0000-0001-9895-2226 NR 33 TC 192 Z9 194 U1 2 U2 24 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUL 14 PY 2000 VL 289 IS 5477 BP 277 EP 281 DI 10.1126/science.289.5477.277 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 334DB UT WOS:000088169400035 ER PT J AU Wu, CJ Fried, LE AF Wu, CJ Fried, LE TI Ring closure mediated by intramolecular hydrogen transfer in the decomposition of a push-pull nitroaromatic: TATB SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID THERMAL-DECOMPOSITION; AB-INITIO; 1,3,5-TRIAMINO-2,4,6-TRINITROBENZENE; TRIAMINOTRINITROBENZENE; ENERGY; SHOCK AB Using gradient-corrected density functional theory, we have investigated various competing mechanisms involved in the early stages of the decomposition of a "push-pull" (containing both electron-donating and withdrawing groups) aromatic (1,3,5-triamino-2,4,6-trinitrobeznene, TATE), and particularly how hydrogen transfer affects the competition between ring closure and single bond scission. On the basis of the obtained energetics, we found several previously suggested mechanisms to be energetically disfavored. These mechanisms include direct N-H, N-O, C-NH(2) bond dissociation, carbon ring cleavage, and the production of NO(2)(-1) anion. Our results indicate that the rate-limiting step is ring closure mediated by intramolecular hydrogen transfer. This mechanism is predicted to have a barrier height of 47.5 kcal/mol. The hydrogen motion forms a biradical state which we suggest is the precursor to further decomposition products, such as benzofurazans. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wu, CJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Fried, Laurence/L-8714-2014 OI Fried, Laurence/0000-0002-9437-7700 NR 32 TC 53 Z9 57 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUL 13 PY 2000 VL 104 IS 27 BP 6447 EP 6452 DI 10.1021/jp001019r PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 333XL UT WOS:000088156000016 ER PT J AU Tikhonov, AM Mitrinovic, DM Li, M Huang, ZQ Schlossman, ML AF Tikhonov, AM Mitrinovic, DM Li, M Huang, ZQ Schlossman, ML TI An X-ray reflectivity study of the water-docosane interface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID CAPILLARY WAVES; CHAIN MOLECULES; VAPOR INTERFACE; NORMAL-ALKANES; SURFACE; SCATTERING; THERMODYNAMICS; DIFFRACTION AB Synchrotron X-ray reflectivity is used to study the electron density profile normal to the interface between bulk water and bulk n-docosane (C22H46), These measurements are interpreted in terms of an error function electron density profile to yield an interfacial width of 5.7 +/- 0.2 Angstrom. In contrast with an earlier measurement on the water-hexane interface, this interfacial width disagrees sharply with the prediction from capillary wave theory, sigma(cap) = 3.5 Angstrom. This width can be accounted for by combining the capillary wave prediction with a contribution from intrinsic structure due to the bulk correlation length of docosane, We also discuss the absence of interfacial freezing at this interface, a phenomenon observed fur n-alkanes of a similar chain length at the alkane-vapor and alkane-silicon oxide interfaces. C1 Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Schlossman, ML (reprint author), Univ Illinois, Dept Phys, 845 W Taylor St, Chicago, IL 60607 USA. RI Tikhonov, Aleksey/N-1111-2016 NR 24 TC 39 Z9 39 U1 1 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 JUL 13 PY 2000 VL 104 IS 27 BP 6336 EP 6339 DI 10.1021/jp001377u PG 4 WC Chemistry, Physical SC Chemistry GA 333XR UT WOS:000088156500003 ER PT J AU Collar, JI Puibasset, J Girard, TA Limagne, D Miley, HS Waysand, G AF Collar, JI Puibasset, J Girard, TA Limagne, D Miley, HS Waysand, G TI Prospects for SIMPLE 2000: a large-mass, low-background superheated droplet detector for WIMP searches SO NEW JOURNAL OF PHYSICS LA English DT Article ID RADIATION-INDUCED NUCLEATION; PULSE-SHAPE DISCRIMINATION; DARK-MATTER SEARCH; LIQUIDS AB The Superheated Instrument for Massive Particle searches (SIMPLE 2000) will consist of an array of 8-16 large active mass (similar or equal to 15 g) superheated droplet detectors (SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make the use of SDDs an attractive approach for the detection of weakly interacting massive particles (WIMPs), namely their intrinsic insensitivity to minimally ionizing particles, high fluorine content, low cost and operation at near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from prototype SDDs for SIMPLE, as well as on the expected immediate increase in sensitivity of the programme, which aims at an exposure of >25 kg day during 2000. The ability of modest-mass fluorine-rich detectors to investigate regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out. C1 Univ Paris 07, Phys Solides Grp, CNRS, UMR 7588, F-75251 Paris 05, France. Univ Paris 06, Phys Solides Grp, CNRS, UMR 7588, F-75251 Paris 05, France. CERN, EP Div, CH-1211 Geneva 23, Switzerland. Univ Lisbon, Ctr Fis Nucl, P-1649003 Lisbon, Portugal. Pacific NW Natl Lab, Richland, WA 99352 USA. Lab Souterrain Bas Bruit de Rustrel Pays Dapt, F-84400 Rustrel, France. RP Collar, JI (reprint author), Univ Paris 07, Phys Solides Grp, CNRS, UMR 7588, F-75251 Paris 05, France. EM juan.colar@cern.ch OI Girard, Thomas/0000-0003-4113-880X NR 34 TC 41 Z9 41 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1367-2630 J9 NEW J PHYS JI New J. Phys. PD JUL 13 PY 2000 VL 2 BP 151 EP 157 AR 14 DI 10.1088/1367-2630/2/1/14 PG 7 WC Physics, Multidisciplinary SC Physics GA 417NV UT WOS:000167841800001 ER PT J AU Mann, G John, KD Baker, RT AF Mann, G John, KD Baker, RT TI Platinum catalyzed diboration using a commercially available catalyst: Diboration of aldimines to alpha-aminoboronate esters SO ORGANIC LETTERS LA English DT Article ID BORONIC ACID INHIBITORS; DIPEPTIDYL PEPTIDASE-IV; PLATINUM(0)-CATALYZED DIBORATION; COMPLEXES; EFFICIENT; ALKYNES; ALKENES; BIS(PINACOLATO)DIBORON; IDENTIFICATION AB [GRAPHICS] Commercially available Pt(cod)Cl-2 catalyzes the diboration of alkenes, alkynes, and aldimines using bis(catecholato)diboron (cod = 1,5-cyclooctadiene). Catalyzed aldimine diboration provides the first direct route to alpha-aminoboronate esters. The diboration product from N-benzylidene-2,6-dimethylanilline is structurally characterized. C1 Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Baker, RT (reprint author), Univ Calif Los Alamos Natl Lab, Div Chem, MS J514, Los Alamos, NM 87545 USA. OI John, Kevin/0000-0002-6181-9330 NR 26 TC 73 Z9 73 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1523-7060 J9 ORG LETT JI Org. Lett. PD JUL 13 PY 2000 VL 2 IS 14 BP 2105 EP 2108 DI 10.1021/ol006008v PG 4 WC Chemistry, Organic SC Chemistry GA 331VR UT WOS:000088039800032 ER PT J AU Link, JM Paolone, VS Reyes, M Yager, PM Anjos, JC Bediaga, I Gobel, C Magnin, J de Miranda, JM Pepe, IM dos Reis, AC Simao, FRA Vale, MA Carrillo, S Casimiro, E Mendez, H Sanchez-Hernandez, A Uribe, C Vazquez, F Cinquini, L Cumalat, JP Ramirez, JE O'Reilly, B Vaandering, EW Butler, JN Cheung, HWK Gaines, I Garbincius, PH Garren, LA Gottschalk, E Gourlay, SA Kasper, PH Kreymer, AE Kutschke, R Bianco, S Fabbri, FL Sarwar, S Zallo, A Cawlfield, C Kim, DY Park, KS Rahimi, A Wiss, J Gardner, R Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Myung, SS Park, H Alimonti, G Boschini, M Brambilla, D Caccianiga, B Calandrino, A D'Angelo, P DiCorato, M Dini, P Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Milazzo, L Moroni, L Pedrini, D Prelz, F Revere, M Sala, A Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, M Pantea, D Ratti, SP Riccardi, C Torre, P Viola, L Vitulo, P Hernandez, H Lopez, AM Mendez, L Mirles, A Montiel, E Olaya, D Quinones, J Rivera, C Zhang, Y Copty, N Purohit, M Wilson, JR Cho, K Handler, T Engh, D Johns, WE Hosack, M Nehring, MS Sales, M Sheldon, PD Stenson, K Webster, MS Sheaff, M Kwon, YJ AF Link, JM Paolone, VS Reyes, M Yager, PM Anjos, JC Bediaga, I Gobel, C Magnin, J de Miranda, JM Pepe, IM dos Reis, AC Simao, FRA Vale, MA Carrillo, S Casimiro, E Mendez, H Sanchez-Hernandez, A Uribe, C Vazquez, F Cinquini, L Cumalat, JP Ramirez, JE O'Reilly, B Vaandering, EW Butler, JN Cheung, HWK Gaines, I Garbincius, PH Garren, LA Gottschalk, E Gourlay, SA Kasper, PH Kreymer, AE Kutschke, R Bianco, S Fabbri, FL Sarwar, S Zallo, A Cawlfield, C Kim, DY Park, KS Rahimi, A Wiss, J Gardner, R Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Myung, SS Park, H Alimonti, G Boschini, M Brambilla, D Caccianiga, B Calandrino, A D'Angelo, P DiCorato, M Dini, P Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Milazzo, L Moroni, L Pedrini, D Prelz, F Revere, M Sala, A Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, M Pantea, D Ratti, SP Riccardi, C Torre, P Viola, L Vitulo, P Hernandez, H Lopez, AM Mendez, L Mirles, A Montiel, E Olaya, D Quinones, J Rivera, C Zhang, Y Copty, N Purohit, M Wilson, JR Cho, K Handler, T Engh, D Johns, WE Hosack, M Nehring, MS Sales, M Sheldon, PD Stenson, K Webster, MS Sheaff, M Kwon, YJ CA FOCUS Collaboration TI A measurement of lifetime differences in the neutral D-meson system SO PHYSICS LETTERS B LA English DT Article AB Using a high statistics sample of photoproduced charm particles from the FOCUS experiment at Fermilab, we compare the lifetimes of neutral D mesons decaying via D-0 --> K- pi(+) and K-K+ to measure the lifetime differences between CP even and CP odd final states. These measurements bear on the phenomenology of D-0 - (D) over bar(0) mixing. If the D-0 --> K- pi(+) is an equal mixture of CP even and CP odd eigenstates, we measure y(CP) = (Gamma(CP even) - Gamma(CP odd))/(Gamma(CP even) + Gamma(CP odd)) = 0.0342 +/- 0.0139 +/- 0.0074. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Davis, CA 95616 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 07000, DF, Mexico. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Illinois, Urbana, IL 61801 USA. Indiana Univ, Bloomington, IN 47405 USA. Korea Univ, Seoul 136701, South Korea. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Milan, Milan, Italy. Univ N Carolina, Asheville, NC 28804 USA. Univ Pavia, Dipartimento Fis Nucl & Teor, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Puerto Rico, Mayaguez, PR 00681 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Tennessee, Knoxville, TN 37996 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Wisconsin, Madison, WI 53706 USA. Yonsei Univ, Seoul 120749, South Korea. Univ Colorado, Boulder, CO 80309 USA. RP Link, JM (reprint author), Univ Calif Davis, Davis, CA 95616 USA. RI Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Anjos, Joao/C-8335-2013; Link, Jonathan/L-2560-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016; Menasce, Dario Livio/A-2168-2016; Gianini, Gabriele/M-5195-2014; OI Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Menasce, Dario Livio/0000-0002-9918-1686; Gianini, Gabriele/0000-0001-5186-0199; Kutschke, Robert/0000-0001-9315-2879; bianco, stefano/0000-0002-8300-4124 NR 15 TC 101 Z9 102 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 JUL 13 PY 2000 VL 485 IS 1-3 BP 62 EP 70 DI 10.1016/S0370-2693(00)00694-8 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 335JF UT WOS:000088239800009 ER PT J AU Bleicher, M Belkacem, M Bass, SA Soff, S Stocker, H AF Bleicher, M Belkacem, M Bass, SA Soff, S Stocker, H TI Enhanced antiproton production in Pb(160 A GeV)+Pb reactions: evidence for quark gluon matter? SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; QUARK-GLUON PLASMA; HADRONIC MATTER; BARYON PRODUCTION; PHASE-TRANSITION; MODEL; EQUATION; STATE; MULTIPLICITIES AB The centrality dependence of the antiproton per participant ratio is studied in Pb(160 A GeV)+ Pb reactions. Antiproton production in collisions of heavy nuclei at the CERN/SPS seems considerably enhanced as compared to conventional hadronic physics, given by the antiproton production rates in pp and antiproton annihilation in (p) over bar p reactions. This enhancement is consistent with the observation of strong in-medium effects in other hadronic observables and may be an indication of partial restoration of chiral symmetry. (C) 2000 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. RP Bleicher, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. 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 38 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 13 PY 2000 VL 485 IS 1-3 BP 133 EP 138 DI 10.1016/S0370-2693(00)00643-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 335JF UT WOS:000088239800017 ER PT J AU Wang, XN AF Wang, XN TI Dynamical screening and radiative parton energy loss in a quark-gluon plasma SO PHYSICS LETTERS B LA English DT Article ID HOT QED PLASMAS; FINITE-TEMPERATURE; QUASI-PARTICLES; QCD; COLLISIONS; NUCLEI AB Dynamical screening in the magnetic part of the one-gluon exchange interaction is included in the study of radiative energy loss of a fast parton propagating inside a quark-gluon plasma. As a result the final radiative energy loss is about twice as large as when only the electric part of one-gluon exchange interaction is considered. A non-perturbative magnetic screening mass is also used in the estimate of the mean-free-path of parton scattering in a hot QCD matter. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Wang, XN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Mailstop 70-319, Berkeley, CA 94720 USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 19 TC 18 Z9 18 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 JUL 13 PY 2000 VL 485 IS 1-3 BP 157 EP 161 DI 10.1016/S0370-2693(00)00642-0 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 335JF UT WOS:000088239800021 ER PT J AU Lykken, J Nandi, S AF Lykken, J Nandi, S TI Asymmetrical large extra dimensions SO PHYSICS LETTERS B LA English DT Article ID KALUZA-KLEIN EXCITATIONS; COUPLING UNIFICATION; TEV; CONSTRAINTS; COMPACTIFICATION; MILLIMETER; MODELS; FERMI AB We study scenarios in which there is a hierarchy of two sets of large compactified extra dimensions. One particularly interesting case has a single millimeter size extra dimension and five TeV-1 size dimensions. The Standard Model gauge bosons have Kaluza-Klein excitations with respect to one of the TeV scale dimensions. We discuss astrophysical constraints on this scenario, as well as prospects for signals at future high energy calliders. (C) 2000 Published by Elsevier Science B.V. C1 Fermi Natl Accelerator Lab, Theory Dept, Batavia, IL 60510 USA. Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. RP Lykken, J (reprint author), Fermi Natl Accelerator Lab, Theory Dept, POB 500, Batavia, IL 60510 USA. NR 39 TC 32 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 13 PY 2000 VL 485 IS 1-3 BP 224 EP 230 DI 10.1016/S0370-2693(00)00667-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 335JF UT WOS:000088239800030 ER PT J AU Sutherland, BM Bennett, PV Sidorkina, O Laval, J AF Sutherland, BM Bennett, PV Sidorkina, O Laval, J TI Clustered damages and total lesions induced in DNA by ionizing radiation: Oxidized bases and strand breaks SO BIOCHEMISTRY LA English DT Article ID COLI ENDONUCLEASE-III; INDUCED SINGLE-STRAND; SUBSTRATE-SPECIFICITY; IRRADIATED DNA; GEL-ELECTROPHORESIS; PYRIMIDINE DIMERS; SENSITIVE SITES; ABASIC SITES; FPG PROTEIN; GLYCOSYLASE AB Ionizing radiation induces both isolated DNA lesions and clustered damages-multiple closely spaced lesions (strand breaks, oxidized purines, oxidized pyrimidines, or abasic sites within a few helical turns). Such clusters are postulated to be difficult to repair and thus potentially lethal or mutagenic lesions. Using highly purified enzymes that cleave DNA at specific classes of damage and electrophoretic assays developed for quantifying isolated and clustered damages in high molecular length genomic DNAs, we determined the relative frequencies of total lesions and of clustered damages involving both strands, and the composition and origin of such clusters. The relative frequency of isolated vs clustered damages depends on the identity of the lesion, with similar to 15-18% of oxidized purines, pyrimidines, or abasic sites in clusters recognized by Fpg, Nth, or Nfo proteins, respectively, but only about half that level of frank single strand breaks in double strand breaks. Oxidized base clusters and abasic site clusters constitute about 80% of complex damages, while double strand breaks comprise only similar to 20% of the total. The data also show that each cluster results from a single radiation (track) event, and thus clusters will be formed at low as well as high radiation doses. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Inst Gustave Roussy, CNRS, UMR 1772, Grp Reparat ADN, F-94805 Villejuif, France. RP Sutherland, BM (reprint author), Brookhaven Natl Lab, Dept Biol, Bldg 463, Upton, NY 11973 USA. RI Bell, Tiffany/F-4403-2010 NR 36 TC 139 Z9 144 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 JUL 11 PY 2000 VL 39 IS 27 BP 8026 EP 8031 DI 10.1021/bi9927989 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 333KA UT WOS:000088128400023 PM 10891084 ER PT J AU Mestayer, MD Carman, DS Asavapibhop, B Barbosa, FJ Bonneau, P Christo, SB Dodge, GE Dooling, T Duncan, WS Dytman, SA Feuerbach, R Gilfoyle, GP Gyurjyan, V Hicks, KH Hicks, RS Hyde-Wright, CE Jacobs, G Klein, A Klein, FJ Kossov, MV Kuhn, SE Magahiz, RA Major, RW Martin, C McGuckin, T McNabb, J Miskimen, RA Mueller, JA Niczyporuk, BB O'Meara, J Qin, LM Raue, BA Robb, J Roudot, F Schumacher, RA Tedeschi, DJ Thompson, RA Tilles, D Tuzel, W VanSyoc, K Vineyard, MF Weinstein, LB Wilkin, GR Yegneswaran, A Yun, J AF Mestayer, MD Carman, DS Asavapibhop, B Barbosa, FJ Bonneau, P Christo, SB Dodge, GE Dooling, T Duncan, WS Dytman, SA Feuerbach, R Gilfoyle, GP Gyurjyan, V Hicks, KH Hicks, RS Hyde-Wright, CE Jacobs, G Klein, A Klein, FJ Kossov, MV Kuhn, SE Magahiz, RA Major, RW Martin, C McGuckin, T McNabb, J Miskimen, RA Mueller, JA Niczyporuk, BB O'Meara, J Qin, LM Raue, BA Robb, J Roudot, F Schumacher, RA Tedeschi, DJ Thompson, RA Tilles, D Tuzel, W VanSyoc, K Vineyard, MF Weinstein, LB Wilkin, GR Yegneswaran, A Yun, J TI The CLAS drift chamber system SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE CLAS; drift chambers; tracking system ID DESIGN AB Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on the toroidal axis. Within the 18 drift chambers are a total of 35,148 individually instrumented hexagonal drift cells. The novel geometry of these chambers provides for good tracking resolution and efficiency, along with large acceptance. The design and construction challenges posed by these large-scale detectors are described, and detailed results are presented from in-beam measurements. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Ohio Univ, Dept Phys, Athens, OH 45701 USA. Jefferson Lab, Newport News, VA 23606 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Massachusetts, Amherst, MA 01003 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Univ Richmond, Richmond, VA 23173 USA. Florida Int Univ, Miami, FL 33199 USA. Univ S Carolina, Columbia, SC 29208 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. CEA Saclay, DAPNIA, SPhN, F-91191 Gif Sur Yvette, France. RP Carman, DS (reprint author), Ohio Univ, Dept Phys, Athens, OH 45701 USA. RI Schumacher, Reinhard/K-6455-2013 OI Schumacher, Reinhard/0000-0002-3860-1827 NR 25 TC 64 Z9 64 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 JUL 11 PY 2000 VL 449 IS 1-2 BP 81 EP 111 DI 10.1016/S0168-9002(00)00151-0 PG 31 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RU UT WOS:000088317400008 ER PT J AU Boger, J Hahn, RL Rowley, JK Carter, AL Hollebone, B Kessler, D Blevis, I Dalnoki-Veress, F DeKok, A Farine, J Grant, DR Hargrove, CK Laberge, G Levine, I McFarlane, K Mes, H Noble, AT Novikov, VM O'Neill, M Shatkay, M Shewchuk, C Sinclair, D Clifford, ETH Deal, R Earle, ED Gaudette, E Milton, G Sur, B Bigu, J Cowan, JHM Cluff, DL Hallman, ED Haq, RU Hewett, J Hykawy, JG Jonkmans, G Michaud, R Roberge, A Roberts, J Saettler, E Schwendener, MH Seifert, H Sweezey, D Tafirout, R Virtue, CJ Beck, DN Chan, YD Chen, X Dragowsky, MR Dycus, FW Gonzalez, J Isaac, MCP Kajiyama, Y Koehler, GW Lesko, KT Moebus, MC Norman, EB Okada, CE Poon, AWP Purgalis, P Schuelke, A Smith, AR Stokstad, RG Turner, S Zlimen, I Anaya, JM Bowles, TJ Brice, SJ Esch, EI Fowler, MM Goldschmidt, A Hime, A McGirt, AF Miller, GG Teasdale, WA Wilhelmy, JB Wouters, JM Anglin, JD Bercovitch, M Davidson, WF Storey, RS Biller, S Black, RA Boardman, RJ Bowler, MG Cameron, J Cleveland, B Ferraris, AP Doucas, G Heron, H Howard, C Jelley, NA Knox, AB Lay, M Locke, W Lyon, J Majerus, S Moorhead, M Omori, M Tanner, NW Taplin, RK Thorman, M Wark, DL West, N Barton, JC Trent, PT Kouzes, R Lowry, MM Bell, AL Bonvin, E Boulay, M Dayon, M Duncan, F Erhardt, LS Evans, HC Ewan, GT Ford, R Hallin, A Hamer, A Hart, PM Harvey, PJ Haslip, D Hearns, CAW Heaton, R Hepburn, JD Jillings, CJ Korpach, EP Lee, HW Leslie, JR Liu, MQ Mak, HB McDonald, AB MacArthur, JD McLatchie, W Moffat, BA Noel, S Radcliffe, TJ Robertson, BC Skensved, P Stevenson, RL Zhu, X Gil, S Heise, J Helmer, RL Komar, RJ Nally, CW Ng, HS Waltham, CE Allen, RC Buhler, G Chen, HH Aardsma, G Andersen, T Cameron, K Chon, MC Hanson, RH Jagam, P Karn, J Law, J Ollerhead, RW Simpson, JJ Tagg, N Wang, JX Alexander, C Beier, EW Cook, JC Cowen, DF Frank, ED Frati, W Keener, PT Klein, JR Mayers, G McDonald, DS Neubauer, MS Newcomer, FM Pearce, RJ Van de Water, RG Van Berg, R Wittich, P Ahmad, QR Beck, JM Browne, MC Burritt, TH Doe, PJ Duba, CA Elliott, SR Franklin, JE Germani, JV Green, P Hamian, AA Heeger, KM Howe, M Drees, RM Myers, A Robertson, RGH Smith, MWE Steiger, TD Van Wechel, T Wilkerson, JF AF Boger, J Hahn, RL Rowley, JK Carter, AL Hollebone, B Kessler, D Blevis, I Dalnoki-Veress, F DeKok, A Farine, J Grant, DR Hargrove, CK Laberge, G Levine, I McFarlane, K Mes, H Noble, AT Novikov, VM O'Neill, M Shatkay, M Shewchuk, C Sinclair, D Clifford, ETH Deal, R Earle, ED Gaudette, E Milton, G Sur, B Bigu, J Cowan, JHM Cluff, DL Hallman, ED Haq, RU Hewett, J Hykawy, JG Jonkmans, G Michaud, R Roberge, A Roberts, J Saettler, E Schwendener, MH Seifert, H Sweezey, D Tafirout, R Virtue, CJ Beck, DN Chan, YD Chen, X Dragowsky, MR Dycus, FW Gonzalez, J Isaac, MCP Kajiyama, Y Koehler, GW Lesko, KT Moebus, MC Norman, EB Okada, CE Poon, AWP Purgalis, P Schuelke, A Smith, AR Stokstad, RG Turner, S Zlimen, I Anaya, JM Bowles, TJ Brice, SJ Esch, EI Fowler, MM Goldschmidt, A Hime, A McGirt, AF Miller, GG Teasdale, WA Wilhelmy, JB Wouters, JM Anglin, JD Bercovitch, M Davidson, WF Storey, RS Biller, S Black, RA Boardman, RJ Bowler, MG Cameron, J Cleveland, B Ferraris, AP Doucas, G Heron, H Howard, C Jelley, NA Knox, AB Lay, M Locke, W Lyon, J Majerus, S Moorhead, M Omori, M Tanner, NW Taplin, RK Thorman, M Wark, DL West, N Barton, JC Trent, PT Kouzes, R Lowry, MM Bell, AL Bonvin, E Boulay, M Dayon, M Duncan, F Erhardt, LS Evans, HC Ewan, GT Ford, R Hallin, A Hamer, A Hart, PM Harvey, PJ Haslip, D Hearns, CAW Heaton, R Hepburn, JD Jillings, CJ Korpach, EP Lee, HW Leslie, JR Liu, MQ Mak, HB McDonald, AB MacArthur, JD McLatchie, W Moffat, BA Noel, S Radcliffe, TJ Robertson, BC Skensved, P Stevenson, RL Zhu, X Gil, S Heise, J Helmer, RL Komar, RJ Nally, CW Ng, HS Waltham, CE Allen, RC Buhler, G Chen, HH Aardsma, G Andersen, T Cameron, K Chon, MC Hanson, RH Jagam, P Karn, J Law, J Ollerhead, RW Simpson, JJ Tagg, N Wang, JX Alexander, C Beier, EW Cook, JC Cowen, DF Frank, ED Frati, W Keener, PT Klein, JR Mayers, G McDonald, DS Neubauer, MS Newcomer, FM Pearce, RJ Van de Water, RG Van Berg, R Wittich, P Ahmad, QR Beck, JM Browne, MC Burritt, TH Doe, PJ Duba, CA Elliott, SR Franklin, JE Germani, JV Green, P Hamian, AA Heeger, KM Howe, M Drees, RM Myers, A Robertson, RGH Smith, MWE Steiger, TD Van Wechel, T Wilkerson, JF CA SNO Collaboration TI The Sudbury Neutrino Observatory SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE solar neutrinos; Cherenkov detector; heavy water; He-3-proportional counters; water purification ID KAMIOKANDE-II DETECTOR; CHERENKOV LIGHT; SOLAR NEUTRINOS; REAL-TIME; WATER; FLUX; OSCILLATIONS; SPECTROSCOPY; CONSTRAINTS; SCATTERING AB The Sudbury Neutrino Observatory is a second-generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Oxford, Nucl & Astrophys Lab, Oxford OX1 3RH, England. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Carleton Univ, Herzberg Lab, Ctr Res Particle Phys, Ottawa, ON K1S 5B6, Canada. AECL Res, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. Laurentian Univ, Dept Phys & Astron, Sudbury, ON P3E 2C6, Canada. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. Univ British Columbia, Dept Elect Engn, Dept Phys & Astron, Vancouver, BC V6T 2A6, Canada. Univ Calif Irvine, Dept Phys, Irvine, CA 92717 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Univ Washington, Nucl Phys Lab, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Boger, J (reprint author), Univ Oxford, Nucl & Astrophys Lab, Keble Rd, Oxford OX1 3RH, England. RI Frank, Edward/A-8865-2012 NR 84 TC 281 Z9 283 U1 3 U2 20 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 JUL 11 PY 2000 VL 449 IS 1-2 BP 172 EP 207 PG 36 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RU UT WOS:000088317400014 ER PT J AU Rehm, KE Borasi, F Jiang, CL Ackermann, D Ahmad, I Brumwell, F Davids, CN Decrock, P Fischer, SM Gorres, J Greene, JP Hackmann, G Harss, B Henderson, D Henning, W Janssens, RVF McMichael, G Nanal, V Nisius, D Nolen, J Pardo, RC Paul, M Reiter, P Schiffer, JP Seweryniak, D Segel, RE Wiedenhover, I Wiescher, M Wuosmaa, AH AF Rehm, KE Borasi, F Jiang, CL Ackermann, D Ahmad, I Brumwell, F Davids, CN Decrock, P Fischer, SM Gorres, J Greene, JP Hackmann, G Harss, B Henderson, D Henning, W Janssens, RVF McMichael, G Nanal, V Nisius, D Nolen, J Pardo, RC Paul, M Reiter, P Schiffer, JP Seweryniak, D Segel, RE Wiedenhover, I Wiescher, M Wuosmaa, AH TI Experiments with a radioactive Ni-56 beam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ION-BEAMS AB A technique for producing a high-quality radioactive Ni-56 (T-1/2 = 6.1 d) beam via the two-accelerator method has been developed. Beam intensities of 2 x 10(-7) Ni-56/s were extracted from the ion source and 2 x 10(4) Ni-56/s were delivered to the target. For a study of neutron transfer reactions in inverse kinematics, a high-efficiency detection system was built consisting of a large solid angle (2.8 sr) high-granularity Si detector array for measuring the outgoing protons in coincidence with the heavy reaction products identified with respect to mass A and nuclear charge Z in the focal plane of a recoil mass separator. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Notre Dame, South Bend, IN 46556 USA. Hebrew Univ Jerusalem, Jerusalem, Israel. RP Rehm, KE (reprint author), Argonne Natl Lab, Div Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 11 PY 2000 VL 449 IS 1-2 BP 208 EP 216 DI 10.1016/S0168-9002(99)01439-4 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RU UT WOS:000088317400015 ER PT J AU Shapira, D Lewis, TA Hulett, LD Ciao, Z AF Shapira, D Lewis, TA Hulett, LD Ciao, Z TI Factors affecting the performance of detectors that use secondary electron emission from a thin foil to determine ion impact position SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE timing and position measurement; ions and nuclei; electron emission from surfaces; electron acceleration and detection; limits to time and position resolution; micro channel plate detectors ID PLATE DETECTOR; COMPACT AB The factors affecting the performance of a Position-Sensitive Timing Detector (PSTD), based on the detection of secondary electrons ejected from a thin foil by the passing ion, were investigated. Different contributions to the observed (generally poor) position resolution were investigated. The effects of multiple scattering in the foil were determined first. We then measured the contribution of the position-sensitive detector and signal-handling electronics. Finally, the effect of electron transport, from the point of emission at the foil surface to the micro-channel plate detector (MCP) surface, was measured and evaluated. Our measurements, as well as a simulation of the electron transport, lead us to conclude that for detectors with foil-to-MCP distance greater than or equal to 5 cm, electron transport limits the devices currently in use to resolution worse than 2 mm (FWHM). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37830 USA. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mech Engn, Knoxville, TN USA. RP Shapira, D (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37830 USA. NR 15 TC 21 Z9 21 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 JUL 11 PY 2000 VL 449 IS 1-2 BP 396 EP 407 DI 10.1016/S0168-9002(99)01444-8 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336RU UT WOS:000088317400036 ER PT J AU Garcia, L French, R Czernik, S Chornet, E AF Garcia, L French, R Czernik, S Chornet, E TI Catalytic steam reforming of bio-oils for the production of hydrogen: effects of catalyst composition SO APPLIED CATALYSIS A-GENERAL LA English DT Article DE nickel catalyst; hydrogen production; steam reforming; biomass pyrolysis; molecular beam mass spectrometry; cobalt; chromium; magnesium; lanthanum; catalyst deactivation ID CARBON-DIOXIDE; FAST PYROLYSIS; OXIDATIVE CONVERSION; BIOMASS GASIFICATION; NI/AL2O3 CATALYSTS; FLUIDIZED-BED; NI CATALYSTS; METHANE; CO2; SYNGAS AB Catalytic steam reforming of condensable vapors (i.e. bio-oils) derived from pyrolysis of biomass is a technically viable process for hydrogen production. In this study the aqueous fraction of bio-oil, generated from fast pyrolysis, was catalytically steam reformed at 825 and 875 degrees C, high space velocity (up to 126,000 h(-1)) and low residence time (26 ms). Using a fixed-bed micro-reactor interfaced with a molecular beam mass spectrometer (MBMS), a variety of research and commercial nickel-based catalysts were tested. The catalysts were prepared by impregnation of an alpha-Al2O3 support with nickel and additives. Since the main constraint in reforming bio-oils is catalyst deactivation caused by carbon deposition, two strategies were applied to improve the performance of the catalysts. The first approach aimed at enhancing steam adsorption to facilitate the partial oxidation, i.e. gasification of coke precursors. The second one attempted to slow down the surface reactions leading to the formation of the coke precursors due to cracking, deoxygenation, and dehydration of adsorbed intermediates. Magnesium and lanthanum were used as support modifiers to enhance steam adsorption while cobalt and chromium additives were applied to reduce coke formation reactions. The cobalt-promoted nickel and chromium-promoted nickel supported on MgO-La2O3-alpha-Al2O3 catalysts showed the best results in the laboratory tests. At the reaction conditions progressive catalyst deactivation was observed leading to a decrease in the yields of hydrogen and carbon dioxide and an increase in carbon monoxide. The loss of activity also resulted in the formation of higher amounts of methane, benzene and other aromatic compounds. Commercial catalysts that were developed for steam reforming of natural gas and crude oil fractions proved to be more efficient for hydrogen production from bio-oil than most of the research catalysts mainly due to the higher water-gas shift activity. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Czernik, S (reprint author), Natl Renewable Energy Lab, 1617 Cole BLvd, Golden, CO 80401 USA. RI Garcia, Lucia/M-7077-2013; OI Garcia Nieto, Lucia/0000-0001-7115-9025 NR 52 TC 319 Z9 348 U1 14 U2 163 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-860X J9 APPL CATAL A-GEN JI Appl. Catal. A-Gen. PD JUL 10 PY 2000 VL 201 IS 2 BP 225 EP 239 DI 10.1016/S0926-860X(00)00440-3 PG 15 WC Chemistry, Physical; Environmental Sciences SC Chemistry; Environmental Sciences & Ecology GA 322JF UT WOS:000087505900008 ER PT J AU Ferrer, JC Liliental-Weber, Z Reese, H Chiu, YJ Hu, E AF Ferrer, JC Liliental-Weber, Z Reese, H Chiu, YJ Hu, E TI Improvement of the interface quality during thermal oxidation of Al0.98Ga0.02As layers due to the presence of low-temperature-grown GaAs SO APPLIED PHYSICS LETTERS LA English DT Article ID SELECTIVE WET OXIDATION; GALLIUM VACANCIES; ALGAAS; HETEROSTRUCTURES; MICROSTRUCTURE AB The role of a low-temperature-grown GaAs (LT GaAs) layer on the lateral oxidation of an Al0.98Ga0.02As/GaAs layer structure has been studied by transmission electron microscopy. Results show that structures incorporating LT GaAs develop better quality oxide/GaAs interfaces compared to reference samples without LT GaAs. While the latter have As accumulation in the vicinity of these interfaces, the structures with LT layers display sharper oxide-GaAs interfaces with a reduced concentration of As. These results are explained in terms of the high Ga vacancy concentration in the LT GaAs and the possible influence of those vacancies in enhancing As diffusion away from the oxide-semiconductor interface. (C) 2000 American Institute of Physics. [S0003-6951(00)01328-0]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. RP Ferrer, JC (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 21 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 10 PY 2000 VL 77 IS 2 BP 205 EP 207 DI 10.1063/1.126925 PG 3 WC Physics, Applied SC Physics GA 329NW UT WOS:000087914100017 ER PT J AU Breese, MBH Alves, LC Hoechbauer, T Nastasi, M AF Breese, MBH Alves, LC Hoechbauer, T Nastasi, M TI Study of the crystalline quality of exfoliated surfaces in hydrogen-implanted silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID INSULATOR MATERIAL TECHNOLOGY; MEV PROTONS AB Hydrogen-implanted "Smart-Cut(R)" silicon is attracting considerable interest for silicon on insulator applications in high-speed, low-power microelectronics. To optimize the fabrication process the mechanisms of bubble growth, defect formation and the origin of the residual surface roughness and damage must be studied under a variety of implantation and annealing conditions. This letter describes the analysis of the crystalline quality of the surfaces of exfoliated bubbles and delaminated layers in hydrogen-implanted silicon. Transmission and backscattering ion channeling are used to observe the separate contributions of lattice damage and internal gas pressure to the exfoliation process. Significant additional damage occurs during the exfoliation/delamination process, which is attributed to mechanically induced plastic deformation of the surface. (C) 2000 American Institute of Physics. [S0003-6951(00)04228-5]. C1 Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. ITN, Dept Fis, P-2686953 Sacavem, Portugal. Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Univ Lisbon, CFNUL, P-1699 Lisbon, Portugal. RP Breese, MBH (reprint author), Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. EM m.breese@surrey.ac.uk RI Breese, Mark/G-2068-2012; Alves, Luis/J-9505-2013 OI Alves, Luis/0000-0001-5369-5019 NR 14 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 10 PY 2000 VL 77 IS 2 BP 268 EP 270 AR PII [S0003-6951(00)04228-5] DI 10.1063/1.126946 PG 3 WC Physics, Applied SC Physics GA 329NW UT WOS:000087914100038 ER PT J AU Toet, D Smith, PM Sigmon, TW Thompson, MO AF Toet, D Smith, PM Sigmon, TW Thompson, MO TI Spatially selective materials deposition by hydrogen-assisted laser-induced transfer SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON AB Si and Al lines were deposited on glass substrates using a transfer technique based on the explosive release of hydrogen from a hydrogenated amorphous Si film melted by a laser pulse. The Si lines have a minimum width of 4.5 mu m and are well defined, while the Al lines are wider and less uniform. Analysis of time-resolved infrared transmission signals reveals that the lines do not break into droplets upon ejection, in contrast to the behavior of unpatterned films. This difference is attributed to the escape of hydrogen through the sides of the molten lines into the adjacent material. (C) 2000 American Institute of Physics. [S0003-6951(00)02828-X]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. RP Toet, D (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-395,7000 East Ave, Livermore, CA 94550 USA. OI Thompson, Michael/0000-0002-4933-009X NR 8 TC 2 Z9 2 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 10 PY 2000 VL 77 IS 2 BP 307 EP 309 DI 10.1063/1.126959 PG 3 WC Physics, Applied SC Physics GA 329NW UT WOS:000087914100051 ER PT J AU Boger, J Hahn, RL Cumming, JB AF Boger, J Hahn, RL Cumming, JB TI Do statistically significant correlations exist between the homestake solar neutrino data and sunspots? SO ASTROPHYSICAL JOURNAL LA English DT Article DE elementary particles; methods : statistical; nuclear reactions, nucleosynthesis, abundances; sunspots ID CAPTURE RATE; NUMBER; FLUX AB It has been suggested by various authors that a significant anticorrelation exists between the Home-stake solar neutrino data and the sunspot cycle. Some of these claims rest on smoothing the data by taking running averages, a method that has recently undergone criticism. We demonstrate that no significant anticorrelation can be found in the Homestake data, or in standard averages of that data. However, when running averages are taken, an anticorrelation seems to emerge whose significance grows as the number of points in the average increases. Our analysis indicates that the apparently high significance of these anticorrelations is an artifact of the failure to consider the loss of independence introduced in the running average process. When this is considered, the significance is reduced to that of the unaveraged data. Furthermore, when evaluated via parametric subsampling, no statistically significant anticorrelation is found. We conclude that the Homestake data cannot be used to substantiate any claim of an anticorrelation with the sunspot cycle. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Boger, J (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Cumming, James/I-3358-2013 OI Cumming, James/0000-0001-6930-0958 NR 17 TC 4 Z9 5 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 JUL 10 PY 2000 VL 537 IS 2 BP 1080 EP 1085 DI 10.1086/309069 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338YP UT WOS:000088451100049 ER PT J AU Piccoli, PMB Abney, KD Schoonover, JR Dorhout, PK AF Piccoli, PMB Abney, KD Schoonover, JR Dorhout, PK TI Synthesis and structural characterization of quaternary thorium selenophosphates: A(2)ThP(3)Se(9) (A = K, Rb) and Cs4Th2P5Se17 SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; STABILIZATION; CHALCOGENIDES; CHEMISTRY; COMPOUND; URANIUM AB Single crystals of A(2)ThP(3)Se(9) (A = K (I), Rb (II)) and Cs(4)Th(2)PsSe(17) (III) form from the reaction of Th and P in a molten A(2)Se(3)/Se (A K, Rb, Cs) flux at 750 degrees C for 100 h. Compound II crystallizes in the triclinic space group P (1) over bar (No. 2) with unit cell parameters a = 10.4582(5) Angstrom, b = 16.5384(8) Angstrom, c = 10.2245(5) Angstrom, alpha = 107.637(1); beta = 91.652(1); gamma = 90.343(1)degrees, and Z = 2. Compound II crystallizes in the triclinic space group P (1) over bar (No. 2) with the unit cell parameters a = 10.5369(5) Angstrom, b = 16.6914(8) Angstrom, 10.2864(5) Angstrom, alpha = 107.614(1)degrees, beta = 92.059(1)degrees, gamma = 90.409(1)degrees and Z = 2. These structures consist of infinite chains of corner-sharing [Th2Se14] units linked by (P2Se6)(4-) anions in two directions to form a ribbonlike structure along the [100] direction. Compounds I and II are isostructural with the previously reported K2UP3Se9. Compound III crystallizes in the monoclinic space group P2(1)/c (No. 14) with unit cell parameters a = 10.238(1) Angstrom, b = 32.182(2) Angstrom, c = 10.749(2) Angstrom; beta = 95.832(1)degrees and Z = 4. Cs4Th2P5Se17 consists of infinite chains of corner-sharing, polyhedral [Th2Se13] units that are also linked by (P2Se6)(4-) anions in the [100] and [010] directions to form a layered structure. The structure of LII features an (Se-2)(2-) anion that is bound eta(2) to Th(2) and eta(1) to Th(1). This anion influences the coordination sphere of the 9-coordinate Th(2) atom such that it is best described as bicapped trigonal prismatic where the eta(2)-bound anion occupies one coordination site. The composition of III may be formulated as Cs4Th2(P2Se6)(5/2)(Se-2) due to the presence of the (Se-2)(2-) unit. Raman spectra for these compounds and their interpretation are reported. C1 Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. Los Alamos Natl Lab, Div Nucl Mat Technol, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Dorhout, PK (reprint author), Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. EM pkd@LAMAR.colostate.edu NR 29 TC 15 Z9 15 U1 0 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 JUL 10 PY 2000 VL 39 IS 14 BP 2970 EP 2976 DI 10.1021/ic990767w PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 333XG UT WOS:000088155600005 PM 11196891 ER PT J AU Kaskel, S Corbett, JD AF Kaskel, S Corbett, JD TI Synthesis, structure, and bonding of A(5)Cd(2)Tl(11), A = Cs, Rb. Naked pentagonal antiprismatic columns centered by cadmium SO INORGANIC CHEMISTRY LA English DT Article ID METALLIC ZINTL PHASE; CRYSTAL-STRUCTURE; INDIUM CLUSTER; NANOTUBES AB A new anionic thallium cluster chain (1)(infinity)[Cd2TI115-] has been discovered in the A-Cd-Tl systems for A = Cs, Rb. The compounds are synthesized by direct fusion of the elements at 700 degrees C and equilibration of the quenched product at 200 degrees C for 1 month. The thallides crystallize in the orthorhombic space group Amm2, Z = 2, a = 5.6107(7) and 5.5999(6) Angstrom, b = 18.090(3) and 17.603(3) Angstrom, c = 13.203(3) and 12.896(2) A for A = Cs and Rb, respectively, and contain chains of fate-sharing pentagonal Tl-10 antiprisms embedded in a matrix of alkali metal cations. Cadmium atoms occupy the center of the antiprisms and donate electrons to the anionic chain. Additional four-bonded Tl atoms on one side of the chain make the structure acentric. The compounds are diamagnetic (chi(296) = -0.8, -4.0 (x 10(-4)) emu/mol, respectively) and metallic (10-20 mu Omega cm at 275 K), and the indirect band gap energy of both compounds is close to zero according to extended Huckel calculations on the isolated chain. C1 Iowa State Univ, Ames Lab, DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, Ames Lab, DOE, Ames, IA 50011 USA. RI Kaskel, Stefan/B-4200-2010; OI Kaskel, Stefan/0000-0003-4572-0303 NR 29 TC 21 Z9 21 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUL 10 PY 2000 VL 39 IS 14 BP 3086 EP 3091 DI 10.1021/ic000061y PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 333XG UT WOS:000088155600019 PM 11196905 ER PT J AU Massick, SM Rabor, JG Elbers, S Marhenke, J Bernhard, S Schoonover, JR Ford, PC AF Massick, SM Rabor, JG Elbers, S Marhenke, J Bernhard, S Schoonover, JR Ford, PC TI Time-resolved infrared spectroscopic study of reactive acyl intermediates relevant to cobalt-catalyzed carbonylations SO INORGANIC CHEMISTRY LA English DT Article ID LASER FLASH-PHOTOLYSIS; MIGRATORY INSERTION; EXCITED-STATES; COMPLEXES; HYDROFORMYLATION; HYDROGEN; ACETALDEHYDE; EQUILIBRIUM; ELIMINATION; ETA-2-ACYL AB Time-resolved infrared spectroscopic studies have been used to characterize the reactive intermediate CH3C(O)Co(CO)(2)-PPh3 (I-Co), which is relevant to the mechanism of the catalysis of alkene hydroformylation by the phosphine-modified cobalt carbonyls. Step-scan FTIR and (variable) single-frequency time-resolved infrared detection on the microsecond time scale were used to record the spectrum of I-Co and to demonstrate that the principal photoproduct of the subsequent reaction of this species at P-CO = 1 atm is the methyl cobalt complex CH3Co-(CO)(3)PPh3 (M-Co). At higher P-CO the trapping of I-Co with CO to re-form CH3C(O)Co(CO)(3)PPh3 (A(Co)) (rate = k(CO)[CO][I-Co]) was shown to become competitive with the rate of acetyl-to-cobalt methyl migration to give M-Co (rate = k(M)[I-Co]) Activation parameters for the competing pathways in benzene were determined to be Delta H-CO(double dagger) = 5.7 +/- 0.4 kJ mol(-1), Delta S-CO(double dagger) = -91 +/- 12 J mol(-1) K-1 and Delta H-M(double dagger) = 40 +/- 2 kJ mol(-1), Delta S-M(double dagger) = -19 +/- 5 J mol(-1) K-1. The effects of varying the solvent on the competitive reactions of I-Co were also explored, and the mechanistic implications of these results are discussed. C1 Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. Univ Calif Los Alamos Natl Lab, Div Chem Sci & Technol, Biosci Biotechnol Grp CST4, Los Alamos, NM 87545 USA. RP Ford, PC (reprint author), Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RI Bernhard, Stefan/A-9389-2008; Ford, Peter/D-1826-2011 OI Ford, Peter/0000-0002-5509-9912 NR 47 TC 17 Z9 17 U1 1 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 JUL 10 PY 2000 VL 39 IS 14 BP 3098 EP 3106 DI 10.1021/ic000378y PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 333XG UT WOS:000088155600021 PM 11196907 ER PT J AU Bernhard, S Omberg, KM Strouse, GF Schoonover, JR AF Bernhard, S Omberg, KM Strouse, GF Schoonover, JR TI Time-resolved IR studies of [Re(LL)(CO)(4)](+) SO INORGANIC CHEMISTRY LA English DT Article ID LOWEST EXCITED-STATE; PHOTOPHYSICAL PROPERTIES; TETRACARBONYL COMPLEXES; INFRARED-SPECTROSCOPY; POLYPYRIDYL COMPLEXES; ELECTRONIC-STRUCTURE; CHARGE-TRANSFER; RHENIUM(I); PHOTOCHEMISTRY; DNA AB Ground-state and time-resolved infrared data are resented in the v(CO) region for [Re(LL)(CO)(4)](+) (LL is 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (dmb), or 1,10-phenanthroline (phen)) in 1,2-dichloroethane at 298 K following 354.7 nm excitation. The data demonstrate formation of a unique excited state for the [Re(LL)(CO)(4)](+) species followed by loss of a single carbonyl ligand to form a fac-Re(CO)(3) solvento complex. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RP Schoonover, JR (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop E549, Los Alamos, NM 87545 USA. RI Bernhard, Stefan/A-9389-2008; Omberg, Kristin/I-5972-2013 NR 35 TC 11 Z9 11 U1 2 U2 11 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 JUL 10 PY 2000 VL 39 IS 14 BP 3107 EP + DI 10.1021/ic991175g PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 333XG UT WOS:000088155600022 PM 11196908 ER PT J AU Dodelson, S Parker, S Thaler, J AF Dodelson, S Parker, S Thaler, J TI Cosmic microwave background: Past, future and present SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 19th International Symposium on Lepton and Photon Interactions CY AUG 09-14, 1999 CL STANFORD UNIV, STANFORD, CALIFORNIA SP Stanford Univ HO STANFORD UNIV ID COLD DARK-MATTER; X-RAY-CLUSTERS; COSMOLOGICAL PARAMETERS; GALAXY CLUSTERS; INFLATIONARY PERTURBATIONS; ANISOTROPY EXPERIMENTS; EIGENMODE ANALYSIS; UNIVERSE; POLARIZATION; RADIATION C1 NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Chicago, IL 60680 USA. RP Dodelson, S (reprint author), NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. NR 85 TC 4 Z9 4 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL 10 PY 2000 VL 15 IS 17 BP 2629 EP 2644 DI 10.1142/S0217751X00001152 PG 16 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 342WG UT WOS:000088667900001 ER PT J AU Fadeev, AG Meagher, MM Kelley, SS Volkov, VV AF Fadeev, AG Meagher, MM Kelley, SS Volkov, VV TI Fouling of poly[-1-(trimethylsilyl)-1-propyne] membranes in pervaporative recovery of butanol from aqueous solutions and ABE fermentation broth SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE pervaporation; fouling; n-butanol; PTMSP ID SUBSTITUTED-POLYACETYLENE MEMBRANES; WATER MIXTURES; POSITRON-ANNIHILATION; GAS-PERMEABILITY; PTMSP MEMBRANES; FREE-VOLUME; ETHANOL; SEPARATION; POLY<1-(TRIMETHYLSILYL)-1-PROPYNE>; POLY(1-TRIMETHYLSILYL-1-PROPYNE) AB Poly[1-(trimethylsilyl)-1-propyne] (PTMSP) dense films were evaluated for n-butanol recovery from aqueous solutions and acetone-butanol-ethanol (ABE) fermentation broth. Flux decline through PTMSP dense films due to polymer compaction under vacuum conditions, relaxation in alcohol and alcohol/water mixtures, and membrane contamination are discussed. Flux decline of a PTMSP film during pervaporation of 20 g/l BuOH/water mixture was fitted to the following function, y=At-b. PTMSP films change their geometry when exposed to alcohol and alcohol/water mixtures and then dried. As a result of the relaxation process, polymer film becomes thicker and denser, effecting membrane performance. PTMSP films that were treated with 70% iso-propanol/water show linear Aux decline versus pervaporation time. Strong lipid adsorption seems to occur on the membrane surface when fermentation broth is used as a feed causing flux decline within short period of time. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nebraska, Biol Proc Dev Facil, Lincoln, NE 68583 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RAS, AV Topchiev Petrochem Synth Inst, Moscow 117912, Russia. RP Meagher, MM (reprint author), Univ Nebraska, Biol Proc Dev Facil, 143 Filley Hall, Lincoln, NE 68583 USA. RI Volkov, Vladimir/J-3757-2013 NR 35 TC 64 Z9 66 U1 0 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 JUL 10 PY 2000 VL 173 IS 1 BP 133 EP 144 DI 10.1016/S0376-7388(00)00359-8 PG 12 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 321YX UT WOS:000087483900011 ER PT J AU Joyce, M AF Joyce, M TI US alternative transportation fuels industry maturing along market-niche lines SO OIL & GAS JOURNAL LA English DT Article C1 US Energy Informat Adm, US DOE, Alternat Fuels Program, Washington, DC 20585 USA. RP Joyce, M (reprint author), US Energy Informat Adm, US DOE, Alternat Fuels Program, Washington, DC 20585 USA. NR 19 TC 1 Z9 1 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 JUL 10 PY 2000 VL 98 IS 28 BP 64 EP + PG 10 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA 333MH UT WOS:000088133500014 ER PT J AU Giesbrecht, GR Whitener, GD Arnold, J AF Giesbrecht, GR Whitener, GD Arnold, J TI Crystal packing forces dictate eta(1)- versus eta(2)-coordination of benzyl groups in [guanidinate]Zr(CH2Ph)(3) SO ORGANOMETALLICS LA English DT Article ID MOLECULAR-STRUCTURE; ZIRCONIUM; COMPLEXES; CHEMISTRY; LIGANDS; DERIVATIVES; REACTIVITY; TRIALKYLS; TITANIUM; METALS AB An X-ray structure determination of {CyNC[N(SiMe3)(2)]NCy}Zr(CH2Ph)(3), crystallized from pentane, differs from the solid-state structure previously reported for the same compound crystallized from toluene. In contrast to the earlier report, we find no evidence for the presence of an eta(2) interaction in the solid state by X-ray crystallography or in, solution by means of H-1 or C-13 NMR spectroscopy. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Arnold, J (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Arnold, John/F-3963-2012 OI Arnold, John/0000-0001-9671-227X NR 19 TC 41 Z9 41 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JUL 10 PY 2000 VL 19 IS 14 BP 2809 EP 2812 DI 10.1021/om000123s PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 333MJ UT WOS:000088133600025 ER PT J AU Albright, CH Barr, SM AF Albright, CH Barr, SM TI Explicit SO(10) supersymmetric grand unified model for the Higgs and Yukawa sectors SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRINO OSCILLATIONS; FERMION MASSES; MATTER AB A complete set of fermion and Higgs superfields is introduced with well-defined SO(10) properties and U(1) X Z(2) X Z(2) family charges from which the Higgs and Yukawa superpotentials are constructed. The structures derived for the four Dirac fermion and right-handed Majorana neutrino mass matrices coincide with those previously obtained from an effective operator approach. Ten mass matrix input parameters accurately yield the twenty masses and mixings of the quarks and leptons with the bimaximal atmospheric and solar neutrino vacuum solutions favored in this simplest version. C1 No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Albright, CH (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. OI Albright, Carl/0000-0002-2252-6359 NR 27 TC 61 Z9 61 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 JUL 10 PY 2000 VL 85 IS 2 BP 244 EP 247 DI 10.1103/PhysRevLett.85.244 PG 4 WC Physics, Multidisciplinary SC Physics GA 331ZN UT WOS:000088048700005 ER PT J AU Abbott, B Abramov, MAV Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Akimov, V 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 Bassler, U Bean, A Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Bueschre, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D 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 Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G 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 Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Juste, A Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Souza, M Stanton, NR Steinbruck, G Stephens, RW Stevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Tarazi, J Taylor, W Tentindo-Repond, S Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Wang, H Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A AF Abbott, B Abramov, MAV Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Akimov, V 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 Bassler, U Bean, A Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Bueschre, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D 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 Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G 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 Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Juste, A Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Souza, M Stanton, NR Steinbruck, G Stephens, RW Stevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Tarazi, J Taylor, W Tentindo-Repond, S Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Wang, H Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A CA D0 Collaboration TI Spin correlation in t(t)over-bar production from p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOP-QUARK PAIR; PRODUCTION CROSS-SECTION; ART. NO. 052001; COLLIDER DETECTOR; E(+)E(-) COLLIDERS; HADRON COLLIDERS; DILEPTON EVENTS; DECAY; MASS; FERMILAB AB The D0 collaboration has performed a study of spin correlation in t (t) over tilde production for the process t (t) over bar --> bW(+)(b) over bar W-, where the W bosons decay to e nu or mu nu. A sample of six events was collected during an exposure of the DO detector to an integrated luminosity of approximately 125 pb(-1) of root s = 1.8 TeV p (p) over bar collisions. The standard model (SM) predicts that the short lifetime of the top quark ensures the transmission of any spin information at production to the t (t) over bar decay products. The degree of spin correlation is characterized by a correlation coefficient kappa. We find that kappa > -0.25 at the 68% confidence level. in agreement with the SM prediction of kappa = 0.88. 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 Ri de Janeiro, Rio De Janeiro, Brazil. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Los Andes, Bogota, Colombia. Univ San Francisco Quito, Quito, Ecuador. Univ Grenoble 1, CNRS, IN2P3, Inst Nucl Sci, Grenoble, France. Univ Aix Marseille 2, CNRS, IN2P3, CPPM, Marseille, France. Univ Paris 06, LPHNE, Paris, France. Univ Paris 07, CNRS, IN2P3, Paris, France. CEA, Serv Phys Particules, DAPNIA, Saclay, France. Panjab Univ, Chandigarh 160014, India. Univ Delhi, Delhi 110007, India. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. 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 MV Lomonosov State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. Univ Lancaster, Lancaster, England. Univ Arizona, Tucson, AZ 85721 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Calif State Univ Fresno, Fresno, CA 93740 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Chicago, IL 60607 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Indiana Univ, Bloomington, IN 47405 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Kansas, Lawrence, KS 66045 USA. Kansas State Univ, Manhattan, KS 66506 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Nebraska, Lincoln, NE 68588 USA. Columbia Univ, New York, NY 10027 USA. Univ Rochester, Rochester, NY 14627 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Langston Univ, Langston, OK 73050 USA. Univ Oklahoma, Norman, OK 73019 USA. Brown Univ, Providence, RI 02912 USA. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. Rice Univ, Houston, TX 77005 USA. Univ Washington, Seattle, WA 98195 USA. RP NYU, New York, NY 10003 USA. RI Sznajder, Andre/L-1621-2016; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Chekulaev, Sergey/O-1145-2015 OI Sznajder, Andre/0000-0001-6998-1108; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Dudko, Lev/0000-0002-4462-3192; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; NR 37 TC 35 Z9 35 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 10 PY 2000 VL 85 IS 2 BP 256 EP 261 DI 10.1103/PhysRevLett.85.256 PG 6 WC Physics, Multidisciplinary SC Physics GA 331ZN UT WOS:000088048700008 ER PT J AU Navin, A Anthony, DW Aumann, T Baumann, T Bazin, D Blumenfeld, Y Brown, BA Glasmacher, T Hansen, PG Ibbotson, RW Lofy, PA Maddalena, V Miller, K Nakamura, T Pritychenko, BV Sherrill, BM Spears, E Steiner, M Tostevin, JA Yurkon, J Wagner, A AF Navin, A Anthony, DW Aumann, T Baumann, T Bazin, D Blumenfeld, Y Brown, BA Glasmacher, T Hansen, PG Ibbotson, RW Lofy, PA Maddalena, V Miller, K Nakamura, T Pritychenko, BV Sherrill, BM Spears, E Steiner, M Tostevin, JA Yurkon, J Wagner, A TI Direct evidence for the breakdown of the N=8 shell closure in Be-12 SO PHYSICAL REVIEW LETTERS LA English DT Article ID CORE EXCITATION; STATES; TRANSITIONS; BEAMS; LI-11 AB Partial cross sections and corresponding momentum distributions have been studied in the: one-neutron knockout reaction (Be-12. Be-11 + gamma) on a Be-9 target at 78 MeV/nucleon. The resulting spectroscopic factors for the only two bound starts of Be-11 an 0.42 +/- 0.06 (1/2(+)) and 0.37 +/- 0.06 (1/2(-)), where the errors an experimental only. This result shows that N = 8 is not a good closed shell in the neutron-rich Be-12 and that the last neutron pair is two-thirds in the (1s(2) + 0d(2)) intruder configuration. C1 Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Bhabha Atom Res Ctr, Div Nucl Phys, Bombay 400085, Maharashtra, India. Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. RP Navin, A (reprint author), Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. RI Glasmacher, Thomas/C-4462-2008; Sherrill, Bradley/B-4098-2009; Sherrill, Bradley/B-3378-2011; Aumann, Thomas/B-1455-2012; Glasmacher, Thomas/H-9673-2014; Nakamura, Takashi/N-5390-2015; Wagner, Andreas/G-3127-2013 OI Glasmacher, Thomas/0000-0001-9436-2448; Nakamura, Takashi/0000-0002-1838-9363; Wagner, Andreas/0000-0001-7575-3961 NR 24 TC 242 Z9 245 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 10 PY 2000 VL 85 IS 2 BP 266 EP 269 DI 10.1103/PhysRevLett.85.266 PG 4 WC Physics, Multidisciplinary SC Physics GA 331ZN UT WOS:000088048700010 ER PT J AU Abdallah, MA Vane, CR Havener, CC Schultz, DR Krause, HF Jones, N Datz, S AF Abdallah, MA Vane, CR Havener, CC Schultz, DR Krause, HF Jones, N Datz, S TI Multiple ionization in fast ion-atom collisions: Simultaneous measurement of recoil momentum and projectile energy loss SO PHYSICAL REVIEW LETTERS LA English DT Article ID IONIZING COLLISIONS; ELECTRON CAPTURE; SPECTROSCOPY; DYNAMICS; SINGLE; NEON; HE; IMPACT AB We report on the fil st experiment that measures simultaneously the full momentum vector of recoil ions and projectile energy loss and scattering angle in ion-atom collisions. We studied multiple: ionization in the collisions of 0.83-MeV/u O7+ with Ne. Recoil ions (Neq+, q = 1-8) were detected in coincidence with single capture to O6+. The results give the first experimental evidence for the increase of the average electron energy with increasing recoil charge state q. The average ejection angle shows a dramatic decrease with q. Results are compared with n-electron classical trajectory Monte Carlo calculations. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Abdallah, MA (reprint author), Oak Ridge Natl Lab, Div Phys, Bldg 5500,POB 2008, Oak Ridge, TN 37831 USA. NR 23 TC 4 Z9 4 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 JUL 10 PY 2000 VL 85 IS 2 BP 278 EP 281 DI 10.1103/PhysRevLett.85.278 PG 4 WC Physics, Multidisciplinary SC Physics GA 331ZN UT WOS:000088048700013 ER PT J AU Held, K Huscroft, C Scalettar, RT McMahan, AK AF Held, K Huscroft, C Scalettar, RT McMahan, AK TI Similarities between the Hubbard and periodic Anderson models at finite temperatures SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL-INSULATOR-TRANSITION; SPIN-DENSITY APPROXIMATION; ALPHA-GAMMA-TRANSITION; KONDO VOLUME-COLLAPSE; MEAN-FIELD THEORY; INFINITE DIMENSIONS; ELECTRONIC-STRUCTURE; FERMION SYSTEMS; GAMMA->ALPHA TRANSITION; SPECTRAL WEIGHT AB The single band Hubbard and the two band periodic Anderson Hamiltonians have traditionally been applied to rather different physical problems-the Mott transition and itinerant magnetism, and Kondo singlet formation and scattering off localized magnetic states, respectively. In this paper, we compare the magnetic and charge correlations, and spectral functions, of the two systems. We show quantitatively that they exhibit remarkably similar behavior, including a nearly identical topology of the finite temperature phase diagrams at half filling. We address potential implications of this for theories of the rare earth "volume collapse" transition. C1 Univ Augsburg, D-86135 Augsburg, Germany. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Held, K (reprint author), Univ Augsburg, D-86135 Augsburg, Germany. RI Held, Karsten/O-4178-2015 OI Held, Karsten/0000-0001-5984-8549 NR 37 TC 45 Z9 45 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 10 PY 2000 VL 85 IS 2 BP 373 EP 376 DI 10.1103/PhysRevLett.85.373 PG 4 WC Physics, Multidisciplinary SC Physics GA 331ZN UT WOS:000088048700037 ER PT J AU Avignone, FT Aalseth, CE Brodzinski, RL AF Avignone, FT Aalseth, CE Brodzinski, RL TI Comment on "Limits on the Majorana neutrino mass in the 0.1 eV range" SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOUBLE-BETA DECAY C1 Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Avignone, FT (reprint author), Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. NR 4 TC 11 Z9 11 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 JUL 10 PY 2000 VL 85 IS 2 BP 465 EP 465 DI 10.1103/PhysRevLett.85.465 PG 1 WC Physics, Multidisciplinary SC Physics GA 331ZN UT WOS:000088048700060 ER PT J AU Gan, S Liang, Y Baer, DR AF Gan, S Liang, Y Baer, DR TI Atomic control of TiO2 (110) surface by oxygen plasma treatment SO SURFACE SCIENCE LA English DT Letter DE alkaline earth metals; plasma processing; surface structure, morphology, roughness, and topography; titanium oxide ID SCANNING-TUNNELING-MICROSCOPY; TIO2(110); VISUALIZATION; DEFECTS; GROWTH; OXIDE; STM AB Segregation of impurities in TiO2 substrates impacts the local atomic structure and stoichiometry of the native TiO2 surfaces. We investigated the effects of oxygen plasma on the TiO2 surfaces. It was found that annealing TiO2 crystals in oxygen plasma at above 500 degrees C effectively removed calcium and carbon contaminants, and dramatically improved the surface morphology and stoichiometry. Scanning tunneling micrographs revealed atomically smooth surfaces with well-defined step-terrace morphology after the plasma treatment, while X-ray photoelectron spectra showed that all the Ti cations on the resulting surfaces were fully coordinated. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Liang, Y (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 24 TC 15 Z9 15 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUL 10 PY 2000 VL 459 IS 3 BP L498 EP L502 DI 10.1016/S0039-6028(00)00415-5 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 334JU UT WOS:000088184000005 ER PT J AU Feller, D Sordo, JA AF Feller, D Sordo, JA TI Performance of CCSDT for diatomic dissociation energies SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BASIS-SET CONVERGENCE; TOTAL ATOMIZATION ENERGIES; GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; DENSITY-FUNCTIONAL THEORIES; INITIO BINDING-ENERGIES; COUPLED-CLUSTER METHODS; WAVE-FUNCTIONS; SYSTEMATIC SEQUENCES; CONFIGURATION-INTERACTION AB Calculations of 11 diatomic dissociation energies with coupled cluster theory through iterative triple excitations highlight both the strength and limitations of this method. By combining very large basis sets (through septuple zeta in some cases) and complete basis set extrapolations with corrections for core/valence correlation, scalar relativistic and atomic/molecular spin-orbit effects, it was possible to achieve excellent agreement with experiment in most cases. However, for C-2 and CN the extent of the multiconfigurational nature of the molecules caused problems for the single configuration-based couple cluster methods. In the worse case, the inclusion of iterative triples resulted in a change with respect to the perturbative triples result which was of the opposite sign to the full configuration interaction change. This work emphasizes the difficulties in achieving uniform chemical accuracy even for ground state, first and second row diatomics. (C) 2000 American Institute of Physics. [S0021-9606(00)30626-2]. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Oviedo, Fac Quim, Dept Quim Fis & Analit, Lab Quim Computac, E-33006 Oviedo, Principado De A, Spain. RP Pacific NW Natl Lab, Environm Mol Sci Lab, MS K8-91,POB 999, Richland, WA 99352 USA. NR 83 TC 159 Z9 160 U1 0 U2 6 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 JUL 8 PY 2000 VL 113 IS 2 BP 485 EP 493 AR PII [S0021-9606(00)30626-2] DI 10.1063/1.481827 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 329DB UT WOS:000087889900006 ER PT J AU Rickes, T Yatsenko, LP Steuerwald, S Halfmann, T Shore, BW Vitanov, NV Bergmann, K AF Rickes, T Yatsenko, LP Steuerwald, S Halfmann, T Shore, BW Vitanov, NV Bergmann, K TI Efficient adiabatic population transfer by two-photon excitation assisted by a laser-induced Stark shift SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STIMULATED RAMAN-SCATTERING; QUANTUM LADDER SYSTEM; RAPID-PASSAGE; MULTILEVEL SYSTEMS; RABI OSCILLATIONS; COHERENT EXCITATION; PULSES; INVERSION; STATES; ORIENTATION AB We demonstrate and analyze a novel scheme for complete transfer of atomic or molecular population between two bound states, by means of Stark-chirped rapid adiabatic passage (SCRAP). In this two-laser technique a delayed-pulse laser-induced Stark shift sweeps the transition frequency between two coupled states twice through resonance with the frequency of the population-transferring coupling laser. The delay of the Stark-shifting pulse with respect to the pulse of the coupling-laser Rabi frequency guarantees adiabatic passage of population at one of the two resonances while the evolution is diabatic at the other. The SCRAP method can give a population-transfer efficiency approaching unity. We discuss the general requirements on the intensity and timing of the pulses that produce the Rabi frequency and, independently, the Stark shift. We particularly stress extension to a double-SCRAP technique, a coherent variant of stimulated emission pumping in the limit of strong saturation. We demonstrate the success of the SCRAP method with experiments in metastable helium, where a two-photon transition provides the Rabi frequency. (C) 2000 American Institute of Physics. [S0021-9606(00)00426-8]. C1 Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. Ukrainian Acad Sci, Inst Phys, UA-03650 Kiev 39, Ukraine. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rickes, T (reprint author), Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. RI Vitanov, Nikolay/A-1248-2013; Halfmann, Thomas/O-4588-2014; BERGMANN, KLAAS/D-5543-2011; OI Halfmann, Thomas/0000-0002-1222-2669; Vitanov, Nikolay/0000-0002-8599-4766 NR 52 TC 114 Z9 120 U1 5 U2 26 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 8 PY 2000 VL 113 IS 2 BP 534 EP 546 DI 10.1063/1.481829 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 329DB UT WOS:000087889900011 ER PT J AU Wang, XB Nicholas, JB Wang, LS AF Wang, XB Nicholas, JB Wang, LS TI Intramolecular Coulomb repulsion and anisotropies of the repulsive Coulomb barrier in multiply charged anions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHOTODETACHMENT PHOTOELECTRON-SPECTROSCOPY; NEGATIVE MOLECULAR-IONS; GAS-PHASE; CONSTRUCTION PRINCIPLE; CLOSED-SHELL; SYSTEMS; CLUSTERS; IONIZATION; CHEMISTRY; STABILITY AB Photoelectron spectra of the three isomers of the benzene dicarboxylate dianion (o-, m-, and p-BDC2-) were measured in the gas phase at five photon energies. Detachment features from the carboxylate groups and the pi electrons of the ring were clearly observed and distinguished. The electron binding energies were found to increase from the very small value of similar to 0.2 eV in o-BDC2- to about 1.0 eV in p-BDC2-, due to the reduced Coulomb repulsion as the two excess charges become farther apart. We found that the repulsive Coulomb barrier (RCB) for detaching electrons from the carboxylates decreases from o-BDC2- to p-BDC2-. However, the RCB for detaching the ring pi electrons was found to be significantly higher and remain constant for the three isomers. This distinct anisotropy in the RCB involving different detachment channels is related to the different intramolecular Coulomb repulsions experienced by electrons localized on the carboxylates and the ring. Theoretical calculations were performed to obtain the equilibrium structures of both the dianions and the monoanions and to gain insight into the intramolecular electrostatic interactions. The two carboxylates in m- and p-BDC2- were shown to be in-plane with the ring whereas the strong Coulomb repulsion in o-BDC2- forces the carboxylate groups out of the plane of the ring. The theoretical results clearly show the localized nature of the excess charges on the carboxylates and help us understand the intramolecular Coulomb repulsions within the three dianions. (C) 2000 American Institute of Physics. [S0021-9606(00)01426-4]. 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, 2710 Univ Dr, Richland, WA 99352 USA. NR 51 TC 41 Z9 41 U1 2 U2 12 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 8 PY 2000 VL 113 IS 2 BP 653 EP 661 DI 10.1063/1.481842 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 329DB UT WOS:000087889900025 ER PT J AU Blake, TA Sharpe, SW Xantheas, SS AF Blake, TA Sharpe, SW Xantheas, SS TI Rotationally resolved spectroscopy of a librational fundamental band of hydrogen fluoride tetramer SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL FREQUENCY-SHIFTS; TRANSFORM INFRARED-SPECTRA; DIODE-LASER SPECTROSCOPY; AB-INITIO CALCULATIONS; IN-IONIC-SYSTEMS; SOLID ARGON; HF DIMER; FTIR SPECTROSCOPY; POTENTIAL-ENERGY; WATER CLUSTERS AB The rotationally resolved spectrum of a fundamental band of hydrogen fluoride tetramer has been recorded using a pulsed slit-jet, diode laser spectrometer. The band has a parallel rotational structure and is assigned as the H-F out-of-plane libration fundamental with A(u) symmetry. Ninety-five ground state combination differences were fit to a symmetric top Hamiltonian to give the following ground state rotational constants: B " = 0.132 081(7) cm(-1), D(J)' = 7.1(7) x 10(-7) cm(-1), D(JK)' = -9(2) x 10(-7) cm(-1), H(JJJ)' = 6(2) x 10(-10) cm(-1), H(JJK)' = 9(7) x 10(-10) cm(-1), H(JKK)' = -1.3(8) x 10(-10) cm(-1). A total of 190 transitions were fit to determine the upper state spectroscopic constants: v(4) = 714.7849(1) cm(-1), B " = 0.129 634(5) cm(-1), Delta(C-B) = 0.001 344 cm(-1), D(J)' = 6.4(5) x 10(-7) cm(-1), D(JK)' = -4.5(6) x 10(-7) cm(-1), Delta D(K) = 2.92(8) x 10(-6) cm(-1), H(JJJ)' = 3(1) x 10(-10) cm(-1), H(JKK)' = -1.55(6) x 10(-8) cm(-1); Delta H(KKK) = -4.65(6)x10(-8) cm(-1). Furthermore, a perpendicular band centered at 752.7 cm(-1) was observed. The band has a rotational line spacing that gives an approximate B " value of 0.132 cm(-1); it has been assigned as the E(u) symmetry, H-F in-plane libration fundamental of the HF tetramer. Finally, a parallel band was observed at 741.0 cm(-1) with B " = 0.076 cm(-1) and has been assigned as the A " symmetry, H-F out-of-plane libration fundamental of the HF pentamer. Structural parameters and harmonic vibrational frequencies are estimated from first-principles, correlated MP2 and CCSD(T) calculations. These are the largest calculations performed to date for this system with respect to both orbital basis set and level of electron correlation. The CCSD(T) harmonic frequencies are, in particular, the first reported for the tetramer at this level of theory. Based on our results, we suggest "best estimates" of R(FF) = 2.51 Angstrom, r(HF) = 0.947 Angstrom, and theta(HFF) = 9.7 degrees for the structural parameters and a range for D(e) of 27.4 to 28.1 kcal/mol (D(0) = 19.7 to 20.4 kcal/mol) for the parameters and for the energy of the tetramer dissociating into four monomers. (C) 2000 American Institute of Physics. [S0021-9606(00)01326-X]. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Blake, TA (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,Battelle Blvd, Richland, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015 NR 83 TC 20 Z9 20 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 8 PY 2000 VL 113 IS 2 BP 707 EP 718 AR PII [S0021-9606(00)01326-X] DI 10.1063/1.481846 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 329DB UT WOS:000087889900031 ER PT J AU Blank, DA Kaufman, LJ Fleming, GR AF Blank, DA Kaufman, LJ Fleming, GR TI Direct fifth-order electronically nonresonant Raman scattering from CS2 at room temperature SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FEMTOSECOND 2-DIMENSIONAL SPECTROSCOPY; TIME-RESOLVED 4-WAVE; LIQUID CS2; 5TH ORDER; INTERMOLECULAR SPECTROSCOPY; POLARIZATION SELECTIVITY; NONLINEAR SPECTROSCOPY; VIBRATIONAL COHERENCE; PLACZEK APPROXIMATION; ISOTROPIC MEDIA AB In this paper we report the measurement of the direct fifth-order electronically nonresonant intermolecular response from liquid CS2 at room temperature. We recently demonstrated that all previous attempts to measure the direct fifth-order response were dominated by third-order cascaded signals [J. Chem Phys. 111, 3105 (1999)]. Here we show that phase matching considerations can be used to provide substantial discrimination against the cascaded third-order signals, and the direct fifth-order response can be measured. The measured responses indicate that the intermolecular spectrum of liquid CS2 at room temperature is well described as homogenous. Comparisons of the data to simulations are discussed. (C) 2000 American Institute of Physics. [S0021-9606(00)00625-5]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Blank, DA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 39 TC 95 Z9 95 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 8 PY 2000 VL 113 IS 2 BP 771 EP 778 DI 10.1063/1.481851 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 329DB UT WOS:000087889900038 ER PT J AU Ueda, Y Gong, E Royer, L Cooper, PN Francone, OL Rubin, EM AF Ueda, Y Gong, E Royer, L Cooper, PN Francone, OL Rubin, EM TI Relationship between expression levels and atherogenesis in scavenger receptor class B, type I transgenics SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID HIGH-DENSITY-LIPOPROTEIN; REVERSE CHOLESTEROL TRANSPORT; CORONARY HEART-DISEASE; HUMAN APOLIPOPROTEIN-B; SR-BI; SELECTIVE UPTAKE; HDL CHOLESTEROL; TARGETED MUTATION; MICE; ATHEROSCLEROSIS AB Both in vitro and in vivo studies of scavenger receptor class B type I (SR-BT) have implicated it as a likely participant in the metabolism of HDL cholesterol, To investigate the effect of SR-BI on atherogenesis, we examined two lines of SR-BI transgenic mice with high (10-fold increases) and low (2-fold increases) SR-BI expression in an inbred mouse background hemizygous for a human apolipoprotein (apo) B transgene, Unlike non-HDL cholesterol levels that minimally differed in the various groups of animals, HDL cholesterol levels were inversely related to SR-BI expression. Mice with the low expression SR-BI transgene had a 50% reduction in HDL cholesterol, whereas the high expression SR-BI transgene was associated with 2-fold decreases in HDL cholesterol as well as dramatic alterations in HDL composition and size including the near absence of alpha-migrating particles as determined by two-dimensional electrophoresis. The low expression SR-BI/apo B transgenics had more than a 2-fold decrease in the development of diet-induced fatty streak lesions compared with the apo B transgenics (4448 +/- 1908 mu m(2)/aorta to 10133 +/- 4035 mu m(2)/aorta; p < 0.001), whereas the high expression SR-BI/apo B transgenics had an atherogenic response similar to that of the apo B transgenics (14692 +/- 7238 mu m(2)/aorta) but 3-fold greater than the low SR-BI/apo E mice (p < 0.001), The prominent anti-atherogenic effect of moderate SR-BI expression provides in vivo support for the hypothesis that HDL functions to inhibit atherogenesis through its interactions with SR-BI in facilitating reverse cholesterol transport. The failure of the high SR-BI/apo B transgenics to have similar or even greater reductions in atherogenesis suggests that the changes resulting from extremely high SR-BI expression including dramatic changes in lipoproteins may have both pro- and anti-atherogenic consequences, illustrating the complexity of the relationship between SR-BI and atherogenesis. C1 Lawrence Berkeley Natl Lab, Genome Sci Dept, Berkeley, CA 94720 USA. Pfizer Inc, Dept Cardiovasc & Metab Dis, Groton, CT 06340 USA. RP Rubin, EM (reprint author), Lawrence Berkeley Natl Lab, Genome Sci Dept, 1 Cyclotron Rd,MS-84-171, Berkeley, CA 94720 USA. NR 32 TC 144 Z9 147 U1 1 U2 3 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 JUL 7 PY 2000 VL 275 IS 27 BP 20368 EP 20373 DI 10.1074/jbc.M000730200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 332QG UT WOS:000088084500022 PM 10751392 ER PT J AU Atienza, JM Suh, M Xenarios, I Landgraf, R Colicelli, J AF Atienza, JM Suh, M Xenarios, I Landgraf, R Colicelli, J TI Human ERK1 induces filamentous growth and cell wall remodeling pathways in Saccharomyces cerevisiae SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PROTEIN-KINASE-C; MAP-KINASE; SIGNAL-TRANSDUCTION; PSEUDOHYPHAL DIFFERENTIATION; RESPONSE PATHWAY; CANDIDA-ALBICANS; MAMMALIAN-CELLS; FISSION YEAST; BUDDING YEAST; KSS1 AB Expression of an activated extracellular signal-regulated kinase 1 (ERK1) construct in yeast cells was used to examine the conservation of function among mitogen-activated protein (MAP) kinases, Sequence alignment of the human MAP kinase ERK1 with all Saccharomyces cerevisiae kinases reveals a particularly strong kinship with Kss1p (invasive growth promoting MAP kinase), Fus3p (pheromone response MAP/ERK kinase), and Mpk1p (cell wall remodeling MAP kinase), A fusion protein of constitutively active human MAP/ERK kinase 1 (MEK) and human ERK1 was introduced under regulated expression into yeast cells. The fusion protein (MEK/ERK) induced a filamentation response element promoter and led to a growth retardation effect concomitant with a morphological change resulting in elongated cells, bipolar budding, and multicell chains. Induction of filamentous growth was also observed for diploid cells following MEK/ERK expression in liquid culture. Neither haploids nor diploids, however, showed marked penetration of agar medium. These effects could be triggered by either moderate MER/ERK expression at 37 degrees C or by high level MEK/ERK expression at 30 degrees C. The combination of high level MEK/ERK expression and 37 degrees C resulted in cell death. The deleterious effects of MEK/ERK expression and high temperature were significantly mitigated by 1 M sorbitol, which also enhanced the filamentous phenotype. MEK/ERK was able to constitutively activate a cell wall maintenance reporter gene, suggesting misregulation of this pathway. In contrast, MEK/ERK effectively blocked expression from a pheromone-responsive element promoter and inhibited mating. These results are consistent with MEK/ERK promoting filamentous growth and altering the cell wall through its ability to partially mimic Kss1p and stimulate a pathway normally controlled by Mpk1p, while appearing to inhibit the normal functioning of the structurally related yeast MAP kinase Fus3p. C1 Univ Calif Los Angeles, DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Inst Mol Biol, Los Angeles, CA 90095 USA. RP Colicelli, J (reprint author), Univ Calif Los Angeles, DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. OI Xenarios, Ioannis/0000-0002-3413-6841 FU NINDS NIH HHS [NS31911] NR 66 TC 17 Z9 20 U1 0 U2 1 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 JUL 7 PY 2000 VL 275 IS 27 BP 20638 EP 20646 DI 10.1074/jbc.M910024199 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 332QG UT WOS:000088084500060 PM 10787425 ER PT J AU Hodge, EM Martinez, P Sweetin, D AF Hodge, EM Martinez, P Sweetin, D TI Determination of inorganic cations in brine solutions by ion chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 12th International Ion Chromatography Symposium (IICS 99) CY SEP 12-15, 1999 CL SAN JOSE, CALIFORNIA DE brine; inorganic cations AB The method for analysis of inorganic cations in brine solutions was developed. Ion chromatography is a well-established and accepted technique in the determination of a variety of inorganic ions. However, there are significant complications when ion chromatography is used to determine trace concentrations of inorganic ions in brine matrices. The brine solution in our study was made to simulate the solution from the Waste Isolation Pilot Plant. Instrumental parameters such as eluent composition, flow-rates, and sample loop volumes were investigated to arrive at the optimum condition for the determination of the cations with minimal dilution. Separation was carried out in a Dionex CG12A/CS12A with 8.25 mM H2SO4 as eluent at 1.2 ml/min flow-rate. Our results indicated that ion chromatography is an accurate acid a good alternative method for the analysis of cations in brine solution. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hodge, EM (reprint author), Univ Calif Los Alamos Natl Lab, E518, Los Alamos, NM 87545 USA. NR 3 TC 9 Z9 10 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUL 7 PY 2000 VL 884 IS 1-2 BP 223 EP 227 DI 10.1016/S0021-9673(00)00203-X PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 330AJ UT WOS:000087940400025 PM 10917441 ER PT J AU Fritz, JS AF Fritz, JS TI Recent developments in the separation of inorganic and small organic ions by capillary electrophoresis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 12th International Ion Chromatography Symposium (IICS 99) CY SEP 12-15, 1999 CL SAN JOSE, CALIFORNIA DE capillary electrophoresis; ion chromatography-capillary electrophoresis; reviews; conductivity detection; detection, electrophoresis; inorganic cations; isotopes; inorganic anions; organic acids ID ZONE ELECTROPHORESIS; CONDUCTIVITY DETECTION; ACIDIC SOLUTION; METAL-CATIONS; ANIONS; CHROMATOGRAPHY; ELECTROLYTES; SELECTIVITY; SYSTEMS; SALT AB Which method should I use for ion analysis, ion chromatography (IC) or capillary electrophoresis (CE)? In terms of actual theoretical plates CE has a clear-cut advantage. The separation ability of IC is adequate for many sample types, and many separation scientists feel that IC offers greater reliability and confidence than CE. However, IC is a more mature technique and there has been more time to solve problems such as peak tailing and to improve reproducibility. The two techniques should be viewed as complementary. A number of recent developments in ion analysis by CE are discussed. These include some simple ways to control electroosmotic flow and improve reproducibility, separation of isotopes, improved methods of indirect photometric detection, a new contactless conductivity detector, separation of ions at low pH, and in solutions of high salt content. Progress in a new technique called IC-CE will be described in which a soluble ion-exchange polymer is added to the capillary electrolyte to separate anions based on differences in both electrophoretic mobility and ion-exchange interactions. (C) 2000 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 Fritz, JS (reprint author), Iowa State Univ, Dept Chem, Gilman Hall, Ames, IA 50011 USA. NR 35 TC 59 Z9 64 U1 1 U2 6 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 JUL 7 PY 2000 VL 884 IS 1-2 BP 261 EP 275 DI 10.1016/S0021-9673(00)00186-2 PG 15 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 330AJ UT WOS:000087940400029 PM 10917445 ER PT J AU Kang, SH Wei, W Yeung, ES AF Kang, SH Wei, W Yeung, ES TI On-column derivatization for the analysis of homocysteine and other thiols by capillary electrophoresis with laser-induced fluorescence detection SO JOURNAL OF CHROMATOGRAPHY B LA English DT Article DE laser induced flourescence detection; homocysteine; thiols ID PERFORMANCE LIQUID-CHROMATOGRAPHY; MICELLAR ELECTROKINETIC CHROMATOGRAPHY; POSSIBLE RISK FACTOR; HUMAN-PLASMA; VASCULAR-DISEASE; AMINO-ACIDS; ZONE-ELECTROPHORESIS; METHIONINE METABOLISM; COBALAMIN DEFICIENCY; CEREBROSPINAL-FLUID AB On-column derivatization and capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection has been developed for the fully automated assay of homocysteine and other thiols. The unique feature of this CE technique comes from the direct injection of a sample including homocysteine, enabling the derivatization with 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadizole (ABD-F) to be accomplished in the capillary. After the derivatization for 10 min at 50 degrees C, the homocysteine was analyzed within 7 min under an applied electric field of 333 V cm(-1). The detection limit obtained for homocysteine with on-column LIF detection was 5.0 nM, as compared to 2.5 nM with pre-column LIF detection. The method is a very simple, fast, and practical approach for the fully automated assay of homocysteine and other thiols contained in low-volume and low-concentration samples. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 50 TC 43 Z9 44 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B PD JUL 7 PY 2000 VL 744 IS 1 BP 149 EP 156 DI 10.1016/S0378-4347(00)00241-3 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 343AV UT WOS:000088680300017 PM 10985576 ER PT J AU Shvartsburg, AA Liu, B Siu, KWM Ho, KM AF Shvartsburg, AA Liu, B Siu, KWM Ho, KM TI Evaluation of ionic mobilities by coupling the scattering on atoms and on electron density SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SODIUM-CHLORIDE NANOCRYSTALS; CARBON CLUSTER ANIONS; STRUCTURAL TRANSITIONS; DRIFT-TUBE; ISOMERS; CATIONS; DISSOCIATION; GEOMETRIES; FULLERENES; MECHANISM AB A recently developed method to calculate gas-phase mobilities by scattering on electron density isosurfaces (SEDI) has been applied to carbon cluster ions. The investigation has covered species belonging to all major structural families identified in drift tube studies (chains, monocyclic and bicyclic rings, graphite sheets, and fullerenes). Relative cross sections of C-n(-) and C-n(+) predicted by SEDI are in excellent agreement with the measurements across a wide range of cluster sizes and shapes. However, absolute values could not be fit for either charge state. This happens because SEDI ignores the long-range ion-buffer gas interaction known to be important for many systems including carbon clusters. To overcome this problem, we propose a new technique to evaluate mobilities by coupling SEDI with trajectory calculations. This approach allows one to introduce the repulsive interaction accurately and still account for the attractive part of the potential. This hybrid SEDI-TC treatment has been found substantially superior to all models previously described in reproducing both absolute and relative mobilities of C-n anions and cations. C1 York Univ, Dept Chem, N York, ON M3J 1P3, Canada. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Siu, KWM (reprint author), York Univ, Dept Chem, 4700 Keele St, N York, ON M3J 1P3, Canada. NR 44 TC 38 Z9 39 U1 0 U2 11 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 JUL 6 PY 2000 VL 104 IS 26 BP 6152 EP 6157 DI 10.1021/jp0004765 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 332CY UT WOS:000088057000007 ER PT J AU Dixon, DA Peterson, KA Francisco, JS AF Dixon, DA Peterson, KA Francisco, JS TI The molecular structures and energetics of Cl2CO, ClCO, Br2CO, and BrCO SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; ATOMIZATION ENERGIES; CHEMISTRY; HEATS; BORON; NEON; AFFINITIES; LIMIT AB The heats of formation of ClCO, Cl2CO, BrCO, and Br2CO have been calculated at high levels of ab initio molecular orbital theory. Geometries and frequencies for the two closed shell molecules were calculated at the MP2 level. The geometries of the two radicals were calculated at the level of coupled cluster theory with single and double excitations including a perturbative treatment of the connected triple excitations (CCSD(T)) with the augmented correlation consistent triple-xi basis set (aug-cc-pVTZ). Extrapolation of the total energies (aug-double, aug-triple, aug-quadruple) to the complete 1-particle basis set limit was performed to further reduce the basis set truncation error. Additional improvements in the atomization energy were achieved by applying corrections for core/valence correlation, scalar relativistic effects, and spin-orbit coupling. Zero point energies were based on MP2 calculated values. Using restricted open shell treatments for the atoms, we find the following heats of formation (kcal/mol) at 0 K: Delta H-f[C(O)Cl-2] = -51.6 +/- 0.5 (calc.) vs -52.2 +/- 0.8 (expt.); Delta H-f(ClCO) -4.6 +/- 0.5 (calc.) vs -5.6 +/- 0.7 (expt.); and Delta H-f[C(O)Br-2] = -22.7 +/- 1.0 (calc.) vs -23.3 +/- 0.1 (expt.), and Delta H-f[BrCO] = 0.7 +/- 1.5 (calc). The radical BrCO is predicted to be only weakly bound with a long quasi-linear Br-C bond length of 3.09 Angstrom, and a Br-CO binding energy (Delta E-elec) of only 1.6 kcal/mol calculated at the CCSD(T) estimated basis set limit. Inclusion of both molecular and atomic spin-orbit coupling effects reduces this to just 0.3 kcal/mol. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Dept Chem, Richland, WA 99352 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. RP Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 58 TC 16 Z9 16 U1 0 U2 2 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 JUL 6 PY 2000 VL 104 IS 26 BP 6227 EP 6232 DI 10.1021/jp000557l PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 332CY UT WOS:000088057000015 ER PT J AU Hay, PJ Martin, RL Schreckenbach, G AF Hay, PJ Martin, RL Schreckenbach, G TI Theoretical studies of the properties and solution chemistry of AnO(2)(2+) and AnO(2)(+) aquo complexes for An = U, Np, and Pu SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; FINE-STRUCTURE SPECTROSCOPY; EXCITATION-ENERGIES; ACTINIDE COMPOUNDS; MULTIPLET STATES; AQUEOUS-SOLUTION; PUO22+; UO22+; ABSORPTION; HYDRATION AB The structures and vibrational frequencies of UO2(H2O)(5)(2+), NPO2(H2O)(5)(2+), and PuO2(H2O)(5)(2+) corresponding to An(VI) oxidation states and UO2(H2O)(5)(+), Np(H2O)(5)(+), and Pu(H2O)(5)(+) corresponding to An(V) have been calculated using density functional theory (DFT) and relativistic effective core potentials (RECPs). The resulting structures are compared to EXAFS solution studies, and the Raman and IR vibrational frequencies of the actinyl unit are compared to experimental studies in solution. Free energies for reactions in solution are computed by combining thermodynamic free energies in the gas phase with a dielectric continuum model to treat solvent effects. The hydrolysis reaction of UO2(H2O)(5)(2+) to form UO2(H2O)(4)(OH)(+) and the reactions for removing or adding a water to the first shell in UO2(H2O)(5)(2+) are examined using this approach. Multiplet and spin-orbit effects not included in a single-configuration DFT wave function are incorporated by model spinorbit CI calculations. PuO2q+ is used as a model for the aquo complexes in a weak ligand field for the cases q = 3 (5f(1) configuration), q = 2 (5f(2)) and q = 1 (5f(3)). The inclusion of these effects results in a different ground state for NpO2(H2O)(5)(2+) and PuO2(H2O)(5)(2+) than that obtained in the original DFT calculations. The reduction potentials for all three AnO(2)(H2O)(5)(2+) complexes in solution is compared with electrochemical experimental data. The trend for the reduction potentials NpO2(H2O)(5)(2+) > PuO2(H2O)(5)(2+) > UO2(H2O)(5)(2+) is found in agreement with experiment, when multiplet and spin-orbit corrections are included, although the absolute reduction potentials are overestimated in all three cases. The possible reasons for this overestimate are examined using all-electron calculations using the ADF method. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. EM pjhay@lanl.gov NR 59 TC 200 Z9 201 U1 9 U2 55 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 JUL 6 PY 2000 VL 104 IS 26 BP 6259 EP 6270 DI 10.1021/jp000519h PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 332CY UT WOS:000088057000020 ER PT J AU Barnes, MD Mehta, A Thundat, T Bhargava, RN Chhabra, V Kulkarni, B AF Barnes, MD Mehta, A Thundat, T Bhargava, RN Chhabra, V Kulkarni, B TI On-off blinking and multiple bright states of single europium ions in Eu3+: Y2O3 nanocrystals SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID FLUORESCENCE; MOLECULES; SPECTROSCOPY AB We show that continuously illuminated single europium ions incorporated in yttrium oxide (Eu3+:Y2O3) nanocrystals (5-15 nm diameter) undergo on-off blinking on a variable time scale ranging from hundreds of milliseconds to several seconds. We observe both a pump-intensity dependent "duty factor" (on-time as a percentage of total measurement time), and quantum jumps between at least three well-defined luminescence intensity levels (bright states) from individual nanoparticles. Interesting switching or oscillation between different bright levels was also observed with a modulation rate that is dependent on pump-laser intensity. These features of single-ion luminescence are not observed for larger particles with multiple chromophores. We propose that these effects derive from pump laser-induced fluctuations between different quasi-stable Eu3+ symmetry sites that effectively modulate the electric dipole transition moment. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Nanocrystals Technol, Briarcliff Manor, NY 10510 USA. RP Barnes, MD (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 15 TC 53 Z9 53 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUL 6 PY 2000 VL 104 IS 26 BP 6099 EP 6102 DI 10.1021/jp001288h PG 4 WC Chemistry, Physical SC Chemistry GA 332CZ UT WOS:000088057100003 ER PT J AU Klimov, VI AF Klimov, VI TI Optical nonlinearities and ultrafast carrier dynamics in semiconductor nanocrystals SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CDSE QUANTUM DOTS; ELECTRON RELAXATION; ENERGY-RELAXATION; DOPED GLASSES; LUMINESCENCE PROPERTIES; DIELECTRIC CONFINEMENT; INTRABAND TRANSITIONS; CHARGE SEPARATION; EXCITONIC STATES; ABSORPTION AB Femtosecond transient absorption in the visible and infrared spectral ranges has been applied to study carrier dynamics and mechanisms for resonant optical nonlinearities in CdSe nanocrystals (NCs) with a variety of surface passivations. Sequential filling of the 1S, 1P, and 1D atomic-like electron orbitals, governed by Fermi statistics, is clearly observed in the NC bleaching spectra recorded at progressively higher pump intensities. We observe that electron-hole (e-h) spatial separation strongly affects electron intraband dynamics. Such dependence indicates a nonphonon energy relaxation mechanism involving e-h interactions. A strong difference in electron and hole relaxation behavior in the stage following initial intraband relaxation is observed. In contrast to electron relaxation, which is sensitive to the quality of surface passivation (i.e., is affected by trapping at surface defects), depopulation dynamics of the initially-excited hole states are identical in NCs with different surface properties, suggesting that these dynamics are due to relaxation into intrinsic NC states. In the regime of multiparticle excitation, a quantization of relaxation rates corresponding to different multiple e-h pair states is observed. This effect is explained in terms of quantum-confined Auger recombination. C1 Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Klimov, VI (reprint author), Los Alamos Natl Lab, Chem Sci & Technol Div, CST-6,MS-J585, Los Alamos, NM 87545 USA. EM klimov@lanl.gov NR 64 TC 566 Z9 571 U1 20 U2 195 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 JUL 6 PY 2000 VL 104 IS 26 BP 6112 EP 6123 DI 10.1021/jp9944132 PG 12 WC Chemistry, Physical SC Chemistry GA 332CZ UT WOS:000088057100006 ER PT J AU He, ZF Kispert, LD Metzger, RM Gosztola, D Wasielewski, MR AF He, ZF Kispert, LD Metzger, RM Gosztola, D Wasielewski, MR TI Carotenoids in liposomes: Photodegradation, excited state lifetimes, and energy transfer SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PHOTOSYNTHETIC REACTION CENTERS; BETA-CAROTENE; LONG POLYENES; RHODOPSEUDOMONAS-VIRIDIS; TEMPERATURE-DEPENDENCE; ELECTRONIC EXCITATIONS; LIGHT ENERGY; FLUORESCENCE; ABSORPTION; SOLVENT AB DMPC (dimyristoyl-L-alpha-phosphatidylcholine) liposomes are used as artificial photosynthetic media to study the behavior of carotenoids. 8'-Apo-beta-caroten-8'-al (I) and beta-carotene (II) degrade faster under irradiation in DMPC liposomes than in organic solvents, which is possibly because vibrational deactivation of carotenoid excited states is less efficient in rigid lipid membranes. The lifetime of the first excited singlet state (SI) of I in DMPC liposomes is 27.2 ps, very close to that in 3-methylpentane (26.4 ps), but longer than its lifetime in EtOH (17.1 ps) or CH2Cl2 (14.1 ps). The lifetime of the S-1 state of I in DMPC liposomes is as expected for an alkane environment. The lifetime of the S-1 state of II in DMPC liposomes is 10.3 ps, very close to its lifetimes in 3-methylpentane (8.1 ps), EtOH (9.2 ps), and CH2Cl2 (8.5 ps). This independence of the S-1 state lifetime of II from the matrix agrees with earlier conclusions. Carotenoid I can suppress the photodegradation of chlorophyll a (Chl a) in liposomes, which shows the protection role of I on Chl cr under strong irradiation. In liposomes, Chi a fluorescence quenching by I is observed when using either the Q(y) band or the Soret band of Chi a as the excitation line. C1 Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Kispert, LD (reprint author), Univ Alabama, Dept Chem, Box 870336, Tuscaloosa, AL 35487 USA. RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 48 TC 27 Z9 27 U1 1 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 JUL 6 PY 2000 VL 104 IS 26 BP 6302 EP 6307 DI 10.1021/jp000064w PG 6 WC Chemistry, Physical SC Chemistry GA 332CZ UT WOS:000088057100030 ER PT J AU Moretto, LG Beaulieu, L Phair, L Wozniak, GJ AF Moretto, LG Beaulieu, L Phair, L Wozniak, GJ TI Statistical exploration of fragmentation phase space and source sizes in nuclear multi-fragmentation SO PHYSICS LETTERS B LA English DT Article ID AR-36+AU-197 COLLISIONS; MULTIFRAGMENT EMISSION; REDUCIBILITY; INSTABILITIES; DYNAMICS AB The multiplicity distributions for individual fragment Z values in nuclear multifragmentation are characterized by their maximum value m(2) A strong indication of statistical coverage of fragmentation phase space is inferred from the dependence m(z) = Z(0)/Z, where Z(0) is the source size. The source sizes coincide with those extracted from the analysis of fixed multiplicity charge distributions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Phair, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RI Beaulieu, Luc/A-6803-2009 OI Beaulieu, Luc/0000-0003-0429-6366 NR 27 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 6 PY 2000 VL 484 IS 3-4 BP 192 EP 197 DI 10.1016/S0370-2693(00)00683-3 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 333PW UT WOS:000088139300003 ER PT J AU Clerac, R Cotton, FA Daniels, LM Dunbar, KR Kirschbaum, K Murillo, CA Pinkerton, AA Schultz, AJ Wang, XP AF Clerac, R Cotton, FA Daniels, LM Dunbar, KR Kirschbaum, K Murillo, CA Pinkerton, AA Schultz, AJ Wang, XP TI Linear tricobalt compounds with Di(2-pyridyl)amide (dpa) ligands: Temperature dependence of the structural and magnetic properties of symmetrical and unsymmetrical forms of Co-3(dpa)(4)Cl-2 in the solid state SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID BOND-STRETCH ISOMERISM; MOLECULAR-STRUCTURE; PHOSPHORUS-DONOR; COMPLEXES; COBALT(II); CRYSTAL; 5-COORDINATE; NITROGEN; HYDROGEN; DETECTOR AB The linear trinuclear compound Co-3(dpa)(4)Cl-2 (1; dpa = di(2-pyridyl)amide anion) crystallizes from CH2Cl2 solution in two forms simultaneously, namely, an orthorhombic form 1 . CH2Cl2 and a tetragonal form 1 . 2CH(2)Cl(2). The three linearly arranged cobalt atoms in 1 are supported by four dpa ligands in a spiral configuration. The chain of cobalt atoms is symmetrical in 1 . CH2Cl2, but unsymmetrical in 1 . 2CH(2)Cl(2). Both crystal structures have been studied at various temperatures. A reversible second-order phase transition (165 K) from orhorhombic (Pnn2) to monoclinic (Pn) symmetry for the crystal of 1 . CH2Cl2 has been documented by X-ray studies at 296, 168, and 109 K as well as a neutron diffraction study at 20 K. The linear tricobalt unit in 1 . CH2Cl2 becomes slightly unsymmetrical at low temperature although the two Co-Co bonds remain statistically equivalent (Co-Co approximate to 2.32 Angstrom) throughout the experimental temperature range. No phase transition was observed for the tetragonal form 1 . 2CH(2)Cl(2) at low temperature, but the Co-Co distances in 1 changed from 2.299(1) and 2.471(1) Angstrom at 298 K to 2.3035(7) and 2.3847(8) Angstrom at 20 K. Magnetic susceptibility measurements indicate that the two compounds are in an S = 1/2 ground state at low temperature and exhibit gradual spin-crossover at higher temperature. C1 Texas A&M Univ, Dept Chem, Mol Struct & Bonding Lab, College Stn, TX 77842 USA. Univ Toledo, Dept Chem, Toledo, OH 43606 USA. Univ Costa Rica, Dept Chem, San Jose, Costa Rica. Argonne Natl Lab, Argonne, IL 60439 USA. RP Cotton, FA (reprint author), Texas A&M Univ, Dept Chem, Mol Struct & Bonding Lab, POB 30012, College Stn, TX 77842 USA. RI Clerac, Rodolphe/C-2800-2008; Wang, Xiaoping/E-8050-2012; Dunbar, Kim/B-6488-2015; OI Wang, Xiaoping/0000-0001-7143-8112; Dunbar, Kim/0000-0001-5728-7805; pinkerton, alan/0000-0002-2239-1992 NR 45 TC 121 Z9 121 U1 1 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 5 PY 2000 VL 122 IS 26 BP 6226 EP 6236 DI 10.1021/ja000515q PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 333JF UT WOS:000088126600012 ER PT J AU Sygula, A Rabideau, PW AF Sygula, A Rabideau, PW TI A practical, large scale synthesis of the corannulene system SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SEMIBUCKMINSTERFULLERENE; BUCKYBOWLS C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Sygula, A (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 29 TC 100 Z9 100 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 5 PY 2000 VL 122 IS 26 BP 6323 EP 6324 DI 10.1021/ja0011461 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 333JF UT WOS:000088126600038 ER PT J AU Sykora, M Maxwell, KA DeSimone, JM Meyer, TJ AF Sykora, M Maxwell, KA DeSimone, JM Meyer, TJ TI Mimicking the antenna-electron transfer properties of photosynthesis SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID PHOTOINDUCED CHARGE SEPARATION; ENERGY-TRANSFER; SOLUBLE POLYMER; ARTIFICIAL PHOTOSYNTHESIS; PHOTOPHYSICAL PROPERTIES; LIGHT ENERGY; THIN-FILMS; COMPLEXES; DENDRIMERS; STORAGE AB A molecular assembly based on derivatized polystyrene is described, which mimics both the light-harvesting and energy-conversion steps of photosynthesis, The system is unique in that the two key parts of a photosynthetic system are incorporated in a functional assembly constructed from polypyridine complexes of Ru-II. This system is truly artificial, as none of the components used in construction of the assembly are present in a natural photosynthetic system. Quantitative evaluation of the energy and electron transfer dynamics after transient irradiation by visible light offers important insights into the mechanisms of energy transport and electron transfer that lead to photosynthetic light-to-chemical energy conversion. C1 Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. RP Meyer, TJ (reprint author), Univ Calif Los Alamos Natl Lab, MS A127 ALDSSR, Los Alamos, NM 87545 USA. NR 59 TC 70 Z9 70 U1 1 U2 6 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 JUL 5 PY 2000 VL 97 IS 14 BP 7687 EP 7691 DI 10.1073/pnas.97.14.7687 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 331ZK UT WOS:000088048400007 PM 10884400 ER PT J AU Zhang, ZT Zhang, RG Joachimiak, A Schlessinger, J Kong, XP AF Zhang, ZT Zhang, RG Joachimiak, A Schlessinger, J Kong, XP TI Crystal structure of human stem cell factor: Implication for stem cell factor receptor dimerization and activation SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TYROSINE KINASE RECEPTOR; C-KIT LIGAND; INTERLEUKIN-5 MONOMER; SIGNAL-TRANSDUCTION; PROTEIN STRUCTURES; DIFFRACTION DATA; FACTOR DIMER; SI-LOCUS; BINDING; GROWTH AB Stem cell factor (SCF) plays important roles in hematopoiesis and the survival, proliferation, and differentiation of mast cells, melanocytes, and germ cells. SCF mediates its biological effects by binding to and activating a receptor tyrosine kinase designated c-kit or SCF receptor. In this report we describe the 2,3-Angstrom crystal structure of the functional core of recombinant human SCF, SCF is a noncovalent homodimer composed of two slightly wedged protomers. Each SCF protomer exhibits an antiparallel four-helix bundle fold. Dimerization is mediated by extensive polar and nonpolar interactions between the two protomers with a large buried surface area. Finally, we have identified a hydrophobic crevice and a charged region at the tail of each protomer that functions as a potential receptor-binding site. On the basis of these observations, a model for SCFc-kit complex formation and dimerization is proposed. C1 NYU, Med Ctr, Dept Pharmacol, New York, NY 10016 USA. NYU, Med Ctr, Dept Biochem, New York, NY 10016 USA. NYU, Med Ctr, Skirball Inst, New York, NY 10016 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kong, XP (reprint author), NYU, Med Ctr, Dept Pharmacol, 550 1st Ave, New York, NY 10016 USA. NR 47 TC 84 Z9 91 U1 0 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUL 5 PY 2000 VL 97 IS 14 BP 7732 EP 7737 DI 10.1073/pnas.97.14.7732 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 331ZK UT WOS:000088048400016 PM 10884405 ER PT J AU Wilson, SM Yip, R Swing, DA O'Sullivan, TN Zhang, Y Novak, EK Swank, RT Russell, LB Copeland, NG Jenkins, NA AF Wilson, SM Yip, R Swing, DA O'Sullivan, TN Zhang, Y Novak, EK Swank, RT Russell, LB Copeland, NG Jenkins, NA TI A mutation in Rab27a causes the vesicle transport defects observed in ashen mice SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HERMANSKY-PUDLAK-SYNDROME; COAT-COLOR PHENOTYPE; PALE EAR EP; MYOSIN-V; MELANOSOME DISTRIBUTION; PURKINJE-CELLS; GENE ENCODES; MUTANT MICE; MOUSE; PROTEIN AB The dilute (d), leaden (ln), and ashen (ash) mutations provide a unique model system for studying vesicle transport in mammals. All three mutations produce a lightened coat color because of defects in pigment granule transport. In addition, all three mutations are suppressed by the semidominant dilute-suppressor (dsu), providing genetic evidence that these mutations function in the same or overlapping transport pathways, Previous studies showed that d encodes a major vesicle transport motor, myosin-VA, which is mutated in Griscelli syndrome patients. Here, using positional cloning and bacterial artificial chromosome rescue, we show that ash encodes Rab27a, Rab GTPases represent the largest branch of the p21 Ras superfamily and are recognized as key players in vesicular transport and organelle dynamics in eukaryotic cells. We also show that ash mice have platelet defects resulting in increased bleeding times and a reduction in the number of platelet dense granules. These defects have not been reported for d and In mice. Collectively, our studies identify Rab27a as a critical gene for organelle-specific protein trafficking in melanocytes and platelets and suggest that Rab27a functions in both MyoVa dependent and independent pathways. C1 NCI, Mouse Canc Genet Program, Frederick Canc Res & Dev Ctr, Frederick, MD 21702 USA. Roswell Pk Canc Inst, Dept Mol & Cell Biol, Buffalo, NY 14263 USA. Oak Ridge Natl Lab, Div Biol, Oak Ridge, TN 37831 USA. RP Jenkins, NA (reprint author), NCI, Mouse Canc Genet Program, Frederick Canc Res & Dev Ctr, Frederick, MD 21702 USA. RI Yip, Richard/J-5289-2012 FU NCI NIH HHS [CA16056, P30 CA016056]; NEI NIH HHS [EY12104, R01 EY012104]; NHLBI NIH HHS [HL31698, R01 HL031698] NR 50 TC 282 Z9 287 U1 2 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUL 5 PY 2000 VL 97 IS 14 BP 7933 EP 7938 DI 10.1073/pnas.140212797 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 331ZK UT WOS:000088048400051 PM 10859366 ER PT J AU Santamarina-Fojo, S Peterson, K Knapper, C Qiu, Y Freeman, L Cheng, JF Osorio, J Remaley, A Yang, XP Haudenschild, C Prades, C Chimini, G Blackmon, E Francois, T Duverger, N Rubin, EM Rosier, M Denefle, P Fredrickson, DS Brewer, HB AF Santamarina-Fojo, S Peterson, K Knapper, C Qiu, Y Freeman, L Cheng, JF Osorio, J Remaley, A Yang, XP Haudenschild, C Prades, C Chimini, G Blackmon, E Francois, T Duverger, N Rubin, EM Rosier, M Denefle, P Fredrickson, DS Brewer, HB TI Complete genomic sequence of the human ABCA1 gene: Analysis of the human and mouse ATP-binding cassette A promoter SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE high density lipoproteins; atherosclerosis; cholesterol efflux ID APOLIPOPROTEIN-A-I; DENSITY-LIPOPROTEIN DEFICIENCY; REVERSE CHOLESTEROL TRANSPORT; TRANSFER PROTEIN GENE; TANGIER-DISEASE; TRANSCRIPTION FACTORS; MOLECULAR MECHANISMS; CELLULAR CHOLESTEROL; NUCLEAR FACTOR-3; RESPONSE ELEMENT AB The ABCA1 gene, a member of the ATP-binding cassette A (ABCA1) transporter superfamily, encodes a membrane protein that facilitates the cellular efflux of cholesterol and phospholipids. Mutations in ABCA1 lead to familiar high density lipoprotein deficiency and Tangier disease. We report the complete human ABCA1 gene sequence, including 1,453 bp of the promoter, 146,581 bp of introns and exons, and 1 kb of the 3' flanking region. The ABCA1 gene spans 149 kb and comprises 50 exons. Sixty-two repetitive Alu sequences were identified in introns 1-49. The transcription start site is 315 bp upstream of a newly identified initiation methionine codon and encodes an ORF of 6,783 bp. Thus, the ABCA1 protein is comprised of 2,261 aa. Analysis of the 1,453 bp 5' upstream of the transcriptional start site reveals multiple binding sites for transcription factors with roles in lipid metabolism. Comparative analysis of the mouse and human ABCA1 promoter sequences identified specific regulatory elements, which are evolutionarily conserved. The human ABCA1 promoter fragment -200 to -80 bp that contains binding motifs for SP1, SP3, E-box, and AP1 modulates cellular cholesterol and cAMP regulation of ABCA1 gene expression. These combined findings provide insights into ABCA1-mediated regulation of cellular cholesterol metabolism and will facilitate the identification of new pharmacologic agents for the treatment of atherosclerosis in humans. C1 NHLBI, NIH, Mol Dis Branch, Bethesda, MD 20892 USA. NIH, Dept Clin Pathol, Bethesda, MD 20892 USA. Ctr Immunol Marseille Luminy, F-13288 Marseille, France. Aventis Pharma, Evry Genom Ctr, F-91047 Evry, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Santamarina-Fojo, S (reprint author), NHLBI, NIH, Mol Dis Branch, 10-7N115,10 Ctr Dr, Bethesda, MD 20892 USA. NR 54 TC 147 Z9 161 U1 0 U2 3 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 JUL 5 PY 2000 VL 97 IS 14 BP 7987 EP 7992 DI 10.1073/pnas.97.14.7987 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 331ZK UT WOS:000088048400060 PM 10884428 ER PT J AU Bookchin, RM Etzion, Z Sorette, M Mohandas, N Skepper, JN Lew, VL AF Bookchin, RM Etzion, Z Sorette, M Mohandas, N Skepper, JN Lew, VL TI Identification and characterization of a newly recognized population of high-Na+, low-K+ low-density sickle and normal red cells SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HEMOGLOBIN CONCENTRATION; LIGHT-SCATTERING; VOLUME; RETICULOCYTES; ACCURATE; BLOOD AB We describe a population of sickle cell anemia red cells (SS RBCs) (approximate to 4%) and a smaller fraction of normal RBCs (<0.03%) that fail to dehydrate when permeabilized to K+ with either valinomycin or elevated internal Ca2+. The nonshrinking, valinomycin-resistant (val-res) fractions, first detected by flow cytometry of density-fractionated SS RBCs, constituted up to 60% of the lightest, reticulocyte-rich (R1) cell fraction, and progressively smaller portions of the slightly denser R2 cells and discocytes. R1 val-res RBCs had a mean cell hemoglobin concentration of approximate to 21 g of Hb per dl, and many had an elongated shape like "irreversibly sickled cells," suggesting a dense SS cell origin. Of three possible explanations for val-res cells, failure of valinomycin to K+-permeabilize the cells, low co-ion permeability, or reduced driving K+ gradient, the latter proved responsible: Both SS and normal val-res RBCs were consistently high-Na+ and low-K+, even when processed entirely in Na-free media. Ca2+ + A23187-induced K+-permeabilization of SS R1 fractions revealed a similar fraction of cal-res cells, whose Rb-86 uptake showed both high Na/K pump and leak fluxes, val-res/calres RBCs might represent either a distinct erythroid genealogy, or an "end-stage" of normal and SS RBCs, This paper focuses on the discovery, basic characterization, and exclusion of artifactual origin of this RBC fraction. Many future studies will be needed to clarify their mechanism of generation and full pathophysiological significance. C1 Yeshiva Univ Albert Einstein Coll Med, Dept Med, Bronx, NY 10461 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Cambridge, Sch Biol Sci, MultiImaging Ctr, Cambridge CB2 3DY, England. Univ Cambridge, Physiol Lab, Cambridge CB2 3EG, England. RP Bookchin, RM (reprint author), Yeshiva Univ Albert Einstein Coll Med, Dept Med, 1300 Morris Pk Ave,Rm 913U, Bronx, NY 10461 USA. FU NHLBI NIH HHS [HL20985, HL28018, HL58512, P01 HL058512, R01 HL028018, R01 HL031579] NR 12 TC 30 Z9 31 U1 2 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 JUL 5 PY 2000 VL 97 IS 14 BP 8045 EP 8050 DI 10.1073/pnas.130198797 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 331ZK UT WOS:000088048400070 PM 10859357 ER PT J AU Chi, YI Huang, LS Zhang, ZL Fernandez-Velasco, JG Berry, EA AF Chi, YI Huang, LS Zhang, ZL Fernandez-Velasco, JG Berry, EA TI X-ray structure of a truncated form of cytochrome f from Chlamydomonas reinhardtii SO BIOCHEMISTRY LA English DT Article ID ELECTRON-TRANSFER REACTION; IRON-SULFUR PROTEIN; LUMEN-SIDE DOMAIN; CRYSTAL-STRUCTURE; B(6)F COMPLEX; RHODOBACTER-SPHAEROIDES; ANGSTROM RESOLUTION; REDOX REACTIONS; B6F COMPLEX; WATER CHAIN AB A truncated form of cytochrome f from Chlamydomonas reinhardtii (an important eukaryotic model organism for photosynthetic electron transfer studies) has been crystallized (space group P2(1)2(1)2(1); three molecules/asymmetric unit) and its structure determined to 2.0 Angstrom resolution by molecular replacement using the coordinates of a truncated turnip cytochrome f as a model. The structure displays the same folding and detailed features as turnip cytochrome f, including (a) an unusual heme Fe ligation by the alpha-amino group of tyrosine 1, (b) a cluster of lysine residues (proposed docking site of plastocyanin), and (c) the presence of a chain of seven water molecules bound to conserved residues and extending between the heme pocket and K58 and K66 at the lysine cluster. For this array of waters, we propose a structural role. Two cytochrome f molecules are related by a noncrystallographic symmetry operator which is a distorted proper 2-fold rotation. This may represent the dimeric relation of the monomers in situ; however, the heme orientation suggested by this model is not consistent with previous EPR measurements on oriented membranes. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Grad Grp Biophys, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. RP Fernandez-Velasco, JG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 81 TC 44 Z9 45 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUL 4 PY 2000 VL 39 IS 26 BP 7689 EP 7701 DI 10.1021/bi000090k PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 329TR UT WOS:000087924800005 PM 10869174 ER PT J AU Skidmore, JA Freitas, BL Crawford, J Satariano, J Utterback, E DiMercurio, L Cutter, K Sutton, S AF Skidmore, JA Freitas, BL Crawford, J Satariano, J Utterback, E DiMercurio, L Cutter, K Sutton, S TI Silicon monolithic microchannel-cooled laser diode array SO APPLIED PHYSICS LETTERS LA English DT Article AB A monolithic microchannel-cooled laser diode array is demonstrated that allows multiple diode-bar mounting with negligible thermal cross talk. The heat sink comprises two main components: a wet-etched Si layer that is anodically bonded to a machined glass block. The continuous wave (cw) thermal resistance of the 10 bar diode array is 0.032 degrees C/W, which matches the performance of discrete microchannel-cooled arrays. Up to 1.5 kW/cm(2) is achieved cw at an emission wavelength of similar to 808 nm. Collimation of a diode array using a monolithic lens frame produced a 7.5 mrad divergence angle by a single active alignment. This diode array offers high average power/brightness in a simple, rugged, scalable architecture that is suitable for large two-dimensional areas. (C) 2000 American Institute of Physics. [S0003-6951(00)00827-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Skidmore, JA (reprint author), SDL Inc, 3530 Bassett St, Santa Cruz, CA 95064 USA. NR 6 TC 29 Z9 34 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 3 PY 2000 VL 77 IS 1 BP 10 EP 12 DI 10.1063/1.126860 PG 3 WC Physics, Applied SC Physics GA 329CZ UT WOS:000087889700004 ER PT J AU Serkland, DK Hadley, GR Choquette, KD Geib, KM Allerman, AA AF Serkland, DK Hadley, GR Choquette, KD Geib, KM Allerman, AA TI Modal frequencies of vertical-cavity lasers determined by an effective-index model SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACE-EMITTING LASERS AB Previously, an effective-index optical model was introduced for the analysis of lateral waveguiding effects in vertical-cavity surface-emitting lasers. We show that the resultant transverse equation obtained in that model is almost identical to the one typically obtained in the analysis of dielectric waveguide problems, such as a step-index optical fiber. In this letter, we extend the effective-index model to obtain predictions of the discrete frequencies of the microcavity modes. As an example, we apply the analysis to vertical-cavity lasers that contain thin-oxide apertures. The model intuitively explains our experimental data and makes quantitative predictions in good agreement with a highly accurate numerical model. (C) 2000 American Institute of Physics. [S0003-6951(00)01627-2]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Serkland, DK (reprint author), Sandia Natl Labs, POB 5800,MS 0603, Albuquerque, NM 87185 USA. NR 13 TC 14 Z9 14 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 3 PY 2000 VL 77 IS 1 BP 22 EP 24 DI 10.1063/1.126864 PG 3 WC Physics, Applied SC Physics GA 329CZ UT WOS:000087889700008 ER PT J AU Herndon, MK Bradford, WC Collins, RT Hawkins, BE Kuech, TF Friedman, DJ Kurtz, SR AF Herndon, MK Bradford, WC Collins, RT Hawkins, BE Kuech, TF Friedman, DJ Kurtz, SR TI Near-field scanning optical microscopy cross-sectional measurements of crystalline GaAs solar cells SO APPLIED PHYSICS LETTERS LA English DT Article ID P-TYPE GAAS AB Near-field scanning optical microscopy (NSOM) was used to study cleaved edges of GaAs solar cell devices. Using visible light for excitation, the NSOM acquired spatially resolved traces of the photocurrent response across the various layers in the device. For excitation energies well above the band gap, carrier recombination at the cleaved surface had a strong influence on the photocurrent signal. Decreasing the excitation energy, which increased the optical penetration depth, allowed the effects of surface recombination to be separated from collection by the pn junction. Using this approach, the NSOM measurements directly observed the effects of a buried minority carrier reflector/passivation layer. (C) 2000 American Institute of Physics. [S0003-6951(00)02227-0]. C1 Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. Univ Wisconsin, Dept Chem Engn, Madison, WI 53706 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Herndon, MK (reprint author), Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. RI Collins, Reuben/O-2545-2014 OI Collins, Reuben/0000-0001-7910-3819 NR 12 TC 4 Z9 4 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 3 PY 2000 VL 77 IS 1 BP 100 EP 102 DI 10.1063/1.126890 PG 3 WC Physics, Applied SC Physics GA 329CZ UT WOS:000087889700034 ER PT J AU Friessnegg, T Aggarwal, S Ramesh, R Nielsen, B Poindexter, EH Keeble, DJ AF Friessnegg, T Aggarwal, S Ramesh, R Nielsen, B Poindexter, EH Keeble, DJ TI Vacancy formation in (Pb,La)(Zr,Ti)O(3) capacitors with oxygen deficiency and the effect on voltage offset SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILM CAPACITORS; POSITRON-ANNIHILATION; IMPRINT; ELECTRODES; DEFECTS AB Vacancy-related defect profiles have been measured for La(0.5)Sr(0.5)CoO(3)/(Pb(0.9)La(0.1))(Zr(0.2)Ti(0.8))O(3)/La(0.5)Sr(0.5)CoO(3) ferroelectric capacitors using a variable-energy positron beam. By varying the layer thickness and the postgrowth processing in a reducing ambient, a capacitor showing oxygen deficiency dominantly in the top electrode and one with deficiency in both electrodes were produced. The capacitor with an asymmetric defect profile showed a voltage offset polarization-voltage hysteresis loop, that with a symmetric distribution of vacancy-related defects showed no offset. These results are discussed in the context of current models for imprint. (C) 2000 American Institute of Physics. [S0003-6951(00)03227-7]. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. USA, Res Lab, Adelphi, MD 20783 USA. Univ Dundee, Ctr Mat Res, Dundee DD1 4HN, Scotland. RP Friessnegg, T (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. EM d.j.keeble@dundee.ac.uk RI Nielsen, Bent/B-7353-2009; Keeble, David /C-6633-2012 OI Nielsen, Bent/0000-0001-7016-0040; Keeble, David /0000-0002-5378-799X NR 16 TC 104 Z9 107 U1 1 U2 23 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 3 PY 2000 VL 77 IS 1 BP 127 EP 129 AR PII [S0003-6951(00)03227-7] DI 10.1063/1.126898 PG 3 WC Physics, Applied SC Physics GA 329CZ UT WOS:000087889700043 ER PT J AU Venezia, VC Brown, RA Kalyanaraman, R Haynes, TE Holland, OW Williams, JS AF Venezia, VC Brown, RA Kalyanaraman, R Haynes, TE Holland, OW Williams, JS TI Comment on "Interstitial-type defects away from the projected ion range in high energy ion implanted and annealed silicon" [Appl. Phys. Lett. 75, 1279 (1999)] SO APPLIED PHYSICS LETTERS LA English DT Letter ID METALS C1 Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. New Jersey Inst Technol, Microelect Res Ctr, Newark, NJ 07102 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN USA. Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT 0200, Australia. RP Venezia, VC (reprint author), Lucent Technol, Bell Labs, 600 Mt Ave, Murray Hill, NJ 07974 USA. RI Haynes, Tony/P-8932-2015; OI Haynes, Tony/0000-0003-2871-4745; kalyanaraman, ramki/0000-0002-5340-029X NR 9 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 3 PY 2000 VL 77 IS 1 BP 151 EP 152 AR PII [S0003-6951(00)00127-3] DI 10.1063/1.126906 PG 2 WC Physics, Applied SC Physics GA 329CZ UT WOS:000087889700051 ER PT J AU Domansky, K Rose, A Grover, WH Exarhos, GJ AF Domansky, K Rose, A Grover, WH Exarhos, GJ TI Localized deposition of zinc oxide films by automated fluid dispensing method SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE localized film deposition; automated fluid dispensing; zinc oxide; chemical sensor; CHEMFET ID ZNO THIN-FILMS; GAS SENSORS; SPRAY PYROLYSIS; TRANSPARENT; PROPERTY AB Optically clear Au- and Ga-doped zinc oxide films have been locally deposited from solution precursors on silicon and silica substrates as micrometer size dots using an automated fluid dispensing method. Dot dimensions have been shown to be strongly dependent on the solution composition and substrate temperature. Solution-dispensed films have been characterized by means of optical transmission and reflectance spectroscopy, spectroscopic ellipsometry, and profilometry measurements. Trivalent Au- and Ga-doped zinc oxide features about 500 mu m in diameter were deposited on chemically-sensitive field-effect transistors (CHEM-FET). Contrasting behavior in measured work function and film resistance was found for Au and Ga doped films upon exposure to hydrogen and ammonia. (C) 2000 Published by Elsevier Science S.A. All rights reserved. C1 Pacific NW Lab, Richland, WA 99352 USA. MIT, Dept Chem, Cambridge, MA 02139 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Domansky, K (reprint author), MIT, Dept Bioengn & Environm Hlth, Room 16-451A, Cambridge, MA 02139 USA. RI Grover, William/E-6995-2011; OI Grover, William/0000-0001-6854-8951 NR 25 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD JUL 3 PY 2000 VL 76 IS 2 BP 116 EP 121 DI 10.1016/S0921-5107(00)00425-6 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 320NR UT WOS:000087407700006 ER PT J AU Kmiecik, M Maj, A Bracco, A Camera, F Casanova, M Leoni, S Million, B Herskind, B Bark, RA Ormand, WE AF Kmiecik, M Maj, A Bracco, A Camera, F Casanova, M Leoni, S Million, B Herskind, B Bark, RA Ormand, WE TI The GDR width in the excited Eu-147 compound nucleus at high angular momentum SO NUCLEAR PHYSICS A LA English DT Article DE Pd-110(Cl-37,xn); E=160, 165, 170 MeV; measured E gamma, l gamma of high and low-energy gamma-rays; gamma-multiplicity; Eu-147 compound nucleus; gamma-decay of GDR; GDR width; deformation parameters; CASCADE calculations; thermal shape fluctuations ID GIANT-DIPOLE-RESONANCE; HOT ROTATING NUCLEI; DECAY; STATES; SHAPE AB High-energy gamma-rays emitted in the decay of the hot compound nucleus Eu-147 have been measured in coincidence with low-energy gamma-rays, The gamma transitions from the different residual nuclei were detected by a multiplicity filter and by Ge detectors. The employed reaction was Cl-37 + (110)pd at bombarding energies of 160, 165 and 170 MeV. The measured high-energy gamma-ray spectra were analysed within the framework of the statistical model using the CASCADE code. The GDR width in the angular momentum interval between 35 and 50 h was found to increase weakly and to be rather well predicted by the thermal shape fluctuation model. Also the deformation parameter beta as a function of the average angular momentum extracted from the data was found to be in general agreement with the model. (C) 2000 Elsevier Science B.V. All rights reserved. C1 H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy. Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Univ Calif Lawrence Livermore Natl Lab, Phys Directorate, Livermore, CA 94551 USA. RP Maj, A (reprint author), H Niewodniczanski Inst Nucl Phys, Ul Radzikowskiego 152, PL-31342 Krakow, Poland. NR 25 TC 33 Z9 33 U1 0 U2 3 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 JUL 3 PY 2000 VL 674 IS 1-2 BP 29 EP 46 DI 10.1016/S0375-9474(00)00166-4 PG 18 WC Physics, Nuclear SC Physics GA 326XH UT WOS:000087762200003 ER PT J AU Grojean, C Cline, J Servant, G AF Grojean, C Cline, J Servant, G TI Supergravity inspired warped compactifications and effective cosmological constants SO NUCLEAR PHYSICS B LA English DT Article DE brane universe; cosmological constant; gauge hierarchy ID EXTRA DIMENSION; BULK FIELDS; DOMAIN-WALL; SOLITONS; STABILIZATION; SUPERSTRINGS; EXPANSION; MONOPOLES; UNIVERSE; TEV AB We propose a supergravity inspired derivation of a Randall-Sundnrm's type action as an effective description of the dynamics of a brane coupled to the bulk through gravity only. The cosmological constants in the bulk and on the brane appear at the classical level when solving the equations of motion describing the bosonic sector of supergravities in ten and eleven dimensions coupled to the brane. They are related to physical quantities like the brane electric charge and thus inherit some of their physical properties. The most appealing property is their quantization: in d(perpendicular to) extra dimensions, Delta(brane) goes like N and Delta(bulk) like N2/(2-d perpendicular to). This dynamical origin also explains the apparent fine-tuning required in the Randall-Sundrum scenario. In our approach, the cosmological constants are derived parameters and cannot be chosen arbitrarily; instead they are determined by the underlying Lagrangian. Some of the branes we construct that support cosmological constant in the bulk have supersymmetric properties: D3-branes of type IIB superstring theory provide an explicit example. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. CEA Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM grojean@thsrv.lbl.gov OI grojean, christophe/0000-0002-7196-7361 NR 89 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 3 PY 2000 VL 578 IS 1-2 BP 259 EP 276 DI 10.1016/S0550-3213(00)00157-7 PG 18 WC Physics, Particles & Fields SC Physics GA 328PY UT WOS:000087860300012 ER PT J AU Kharzeev, D Levin, E AF Kharzeev, D Levin, E TI Scale anomaly and "soft" pomeron in QCD SO NUCLEAR PHYSICS B LA English DT Article ID LOW-ENERGY THEOREMS; BFKL POMERON; QUANTUM CHROMODYNAMICS; DIFFRACTION SCATTERING; GLUON DISTRIBUTION; RESONANCE PHYSICS; VACUUM; APPROXIMATION; QUARK; MASS AB We propose a new non-perturbative approach to hadronic interactions at high energies and small momentum transfer, which is based on the scale anomaly of QCD and emphasizes the role of semiclassical vacuum fields. We find that the hadron scattering amplitudes exhibit Regge behavior and evaluate the intercept alpha(0) of the corresponding trajectory. Both the intercept and the scale for the slope of the trajectory appear to be determined by the energy density of non-perturbative QCD vacuum (the gluon condensate). Numerically, we find Delta = alpha(0) - 1 = 0.08 divided by 0.1, consistent with the values ascribed phenomenologically to the "soft" pomeron. For arbitrary numbers of colors N-c and flavors N-f, Delta is found to be proportional to (N-f/N-c)(2); however, in the large N-c (N-f fixed) limit, Delta similar to N-c(0). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, RIKEN, BNL, Res Ctr, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, HEP Dept, IL-69978 Tel Aviv, Israel. RP Brookhaven Natl Lab, RIKEN, BNL, Res Ctr, Upton, NY 11973 USA. EM kharzeev@bnl.gov; leving@post.tau.ac.il NR 64 TC 48 Z9 48 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL 3 PY 2000 VL 578 IS 1-2 BP 351 EP 363 DI 10.1016/S0550-3213(00)00158-9 PG 13 WC Physics, Particles & Fields SC Physics GA 328PY UT WOS:000087860300016 ER PT J AU Feng, HXC Mendez, AJ Heritage, JP Lennon, WJ AF Feng, HXC Mendez, AJ Heritage, JP Lennon, WJ TI Effects of optical layer impairments on 2.5 Gb/s optical CDMA transmission SO OPTICS EXPRESS LA English DT Article ID NETWORKS AB We conducted a computer simulation study to assess the effects of optical layer impairments on optical CDMA (O-CDMA) transmission of 8 asynchronous users at 2.5 Gb/s each user over a 214-km link. It was found that with group velocity dispersion compensation, two other residual effects, namely, the nonzero chromatic dispersion slope of the single mode fiber (which causes skew) and the non-uniform EDFA gain (which causes interference power level to exceed signal power level of some codes) degrade the signal to multi-access interference (MAI) ratio. In contrast, four wave mixing and modulation due to the Kerr and Raman contributions to the fiber nonlinear refractive index are less important. Current wavelength-division multiplexing (WDM) technologies, including dispersion management, EDFA gain flattening, and 3(rd) order dispersion compensation, are sufficient to overcome the impairments to the O-CDMA transmission system that we considered. (C) 2000 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Davis, CA 95616 USA. Mendez R&D Associates, El Segundo, CA 90245 USA. RP Feng, HXC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 16 TC 12 Z9 12 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD JUL 3 PY 2000 VL 7 IS 1 BP 2 EP 9 PG 8 WC Optics SC Optics GA 331CP UT WOS:000088000000001 PM 19404363 ER PT J AU Demos, SG Radousky, HB Alfano, RR AF Demos, SG Radousky, HB Alfano, RR TI Deep subsurface imaging in tissues using spectral and polarization filtering SO OPTICS EXPRESS LA English DT Article ID SCATTERING MEDIA; FLUORESCENCE MICROSCOPY; OPTICAL POLARIZATION; TURBID MEDIA; LIGHT; BACKSCATTERING; SPECTROSCOPY; PHOTOGRAPHY; TOMOGRAPHY; COHERENCE AB Deep subsurface imaging in tissues is demonstrated by employing both spectral and polarization discrimination of the backscattered photons. This technique provides enhancement in the visibility of subsurface structures via processing of the depolarized images obtained using polarized illumination at different wavelengths. The experimental results demonstrate detection and imaging of a high-scattering object located up to 1.5-cm beneath the surface of a host chicken tissue used as the model medium. (C) 2000 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94580 USA. CUNY City Coll, Inst Ultrafast Spect & Laser, New York, NY 10031 USA. RP Demos, SG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94580 USA. NR 22 TC 112 Z9 113 U1 2 U2 15 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD JUL 3 PY 2000 VL 7 IS 1 BP 23 EP 28 PG 6 WC Optics SC Optics GA 331CP UT WOS:000088000000003 PM 19404365 ER PT J AU Moehs, DP Church, DA Bhatti, MI Perger, WF AF Moehs, DP Church, DA Bhatti, MI Perger, WF TI Excited-configuration metastable level lifetimes of Cl-like MnIX and Fe X SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRECISION-MEASUREMENT; ION-TRAP AB Forbidden transitions from levels with P-3 and D-1 cores in excited configurations of Cl-like Mn IX and Fe X have been isolated using interference filters. The fluorescence decay lifetimes of ions orbiting in a Kingdon ion trap were measured. New relativistic configuration interaction calculations of relevant level lifetimes, to aid the analysis, based on B-spline basis sets, are also presented. Line identifications and experimental lifetimes are Mn IX (D-4(7/2)-F-4(9/2)):363(-3/ + 7) nm; tau(Mn IX 3p(4)((3)p)3d(4)F(9/2)) = 210 +/- 42 ms: tau(Fe X, 3p(4)(P-3)3d(4)F(9/2)) = 85.7 +/- 9.2 ms; tau(Fe X, 3p(4)(P-3)3d(4)F(7/2)) = 93 +/- 30 ms; and tau(Fe X, 3p(4)(D-1)3d(2)G(9/2)) = 17.8 +/- 3.1 ms. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Univ Texas Pan Amer, Phys & Geol Dept, Edinburg, TX 78539 USA. Michigan Technol Univ, Dept Elect Engn & Phys, Houghton, MI 49931 USA. RP Moehs, DP (reprint author), Argonne Natl Lab, Div Phys, Bldg 203, Argonne, IL 60439 USA. NR 17 TC 15 Z9 15 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 JUL 3 PY 2000 VL 85 IS 1 BP 38 EP 41 DI 10.1103/PhysRevLett.85.38 PG 4 WC Physics, Multidisciplinary SC Physics GA 330JR UT WOS:000087959400010 ER PT J AU Jiang, XY Soukoulis, CM AF Jiang, XY Soukoulis, CM TI Time dependent theory for random lasers SO PHYSICAL REVIEW LETTERS LA English DT Article ID AMPLIFYING RANDOM-MEDIA; LIGHT; AMPLIFICATION; LOCALIZATION; GAIN; TRANSMISSION; ABSORPTION; SYMMETRY AB A model to simulate the phenomenon of random lasing is presented. It couples Maxwell's equations with the rate equations of electronic population in a disordered system. Finite difference time domain methods are used to obtain the field pattern and the spectra of localized lasing modes inside the system. A critical pumping rate P-r(c) exists for the appearance of the lasing peaks. The number of lasing modes increases with the pumping rate and the length of the system. There is a lasing mode repulsion. This property leads to a saturation of the number of modes for a given size system and a relation between the localization length xi and average mode length L-m. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Jiang, XY (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. RI Soukoulis, Costas/A-5295-2008 NR 17 TC 253 Z9 266 U1 8 U2 53 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 JUL 3 PY 2000 VL 85 IS 1 BP 70 EP 73 DI 10.1103/PhysRevLett.85.70 PG 4 WC Physics, Multidisciplinary SC Physics GA 330JR UT WOS:000087959400018 ER PT J AU Bermejo, FJ Saboungi, ML Price, DL Alvarez, M Roessli, B Cabrillo, C Ivanov, A AF Bermejo, FJ Saboungi, ML Price, DL Alvarez, M Roessli, B Cabrillo, C Ivanov, A TI Persistence of well-defined collective excitations in a molten transition metal SO PHYSICAL REVIEW LETTERS LA English DT Article ID DYNAMIC STRUCTURE FACTOR; NEUTRON-SCATTERING; SIMULATION; LIQUIDS; MODEL AB Well-defined microscopic collective excitations are found in liquid Ni at 1763 K by means of inelastic neutron scattering. Such excitations are supported by the liquid despite an anharmonic character of its thermodynamic functions. Consideration of the detailed shape of the interionic pair potential provides a way to understand why atomic motions at microscopic scales behave in a way much closer to the alkali metals than to the liquefied rare gases. C1 CSIC, E-28006 Madrid, Spain. Argonne Natl Lab, Argonne, IL 60439 USA. ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. RP Bermejo, FJ (reprint author), CSIC, Serrano 119-123, E-28006 Madrid, Spain. RI Price, David Long/A-8468-2013; Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 26 TC 32 Z9 32 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 JUL 3 PY 2000 VL 85 IS 1 BP 106 EP 109 DI 10.1103/PhysRevLett.85.106 PG 4 WC Physics, Multidisciplinary SC Physics GA 330JR UT WOS:000087959400027 ER PT J AU Aranson, IS Kalatsky, VA Vinokur, VM AF Aranson, IS Kalatsky, VA Vinokur, VM TI Continuum field description of crack propagation SO PHYSICAL REVIEW LETTERS LA English DT Article ID BRITTLE-FRACTURE; DYNAMIC FRACTURE; INSTABILITY; SILICON; STABILITY; MECHANISM; SURFACE; TIP AB We develop continuum field model for crack propagation in brittle amorphous solids. The model is represented by equations for elastic displacements combined with the order parameter equation which accounts for the dynamics of defects. This model captures ail important phenomenology of crack propagation: crack initiation, propagation, dynamic fracture instability, sound emission, crack branching, and fragmentation. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Aranson, IS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Aranson, Igor/I-4060-2013 NR 33 TC 118 Z9 120 U1 5 U2 23 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 JUL 3 PY 2000 VL 85 IS 1 BP 118 EP 121 DI 10.1103/PhysRevLett.85.118 PG 4 WC Physics, Multidisciplinary SC Physics GA 330JR UT WOS:000087959400030 ER PT J AU Morita, K Itoh, KM Muto, J Mizoguchi, K Usami, N Shiraki, Y Haller, EE AF Morita, K Itoh, KM Muto, J Mizoguchi, K Usami, N Shiraki, Y Haller, EE TI Growth and characterization of Ge-70(n)/Ge-74(n) isotope superlattices SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st Joint Conference on Silicon Epitaxy and Heterostructures (UC-Si) CY SEP 12-17, 1999 CL ZAO, JAPAN SP Japan Soc Promot Sci, Tokyo Univ, Res Inst Elect Commun DE isotope superlattices; molecular beam epitaxy; Raman scattering; LO phonons; linear-chain model; interface mixing ID GE; PHONONS AB We report on the molecular beam epitaxial (MBE) growth of Ge-70(n)/Ge-74(n) isotope superlattices composed of alternating layers of the stable isotopes Ge-70 and Ge-74. Samples prepared in this work have atomic layers n = 4, 8, 16, and 32. All superlattices are p-type having a net-impurity concentration of similar to 10(16) cm(-3). Zone-folding of optical phonons due to the mass periodicity in the growth direction has been observed clearly for all samples using high resolution Raman spectroscopy. The corresponding phonon mode of each Raman peak has been indexed according to theoretical calculations using the linear-chain model and the planar bond-charge model. The frequency of the Raman peaks found by the experiment agree very well with those of the phonon modes calculated for each superlattice structure. A detailed analysis of the Raman spectra concludes that the degree of interface mixing between Ge-70 and Ge-74 layers for our typical growth condition is less than two monolayers. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Keio Univ, Dept Appl Phys & Physicoinformat, Yokohama, Kanagawa 2238522, Japan. JST, PRESTO, Yokohama, Kanagawa 2238522, Japan. Osaka City Univ, Dept Appl Phys, Osaka 5588585, Japan. Univ Tokyo, RCAST, Tokyo 1538904, Japan. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Labs, Berkeley, CA 94720 USA. RP Morita, K (reprint author), Keio Univ, Dept Appl Phys & Physicoinformat, Yokohama, Kanagawa 2238522, Japan. RI Usami, Noritaka/C-1720-2009; Itoh, Kohei/C-5738-2014 NR 6 TC 20 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL 3 PY 2000 VL 369 IS 1-2 BP 405 EP 408 DI 10.1016/S0040-6090(00)00901-9 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 330BC UT WOS:000087942100091 ER PT J AU Choi, MG Angelici, RJ AF Choi, MG Angelici, RJ TI Pyridine-pyridine pi-pi stacking interactions in pentacarbonyl[pyridine4(1H)-thione]tungsten(0) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID REACTIVITY; COMPLEXES AB In the title compound, [W(C5H5NS)(CO)(5)], the pyridine-4-thiol ligand coordinates through the sulfur in the thione mode. The coordination sphere around the W atom is distorted from octahedral geometry by intermolecular hydrogen bonding and steric interactions between the pyridine ring and two CO ligands. An intermolecular pyridine-pyridine ring distance of 3.47 (1) Angstrom indicates pi-pi stacking interactions between these ligand units. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Yonsei Univ, Dept Chem, Seoul 120749, South Korea. RP Angelici, RJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 16 TC 6 Z9 6 U1 1 U2 3 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 JUL PY 2000 VL 56 BP 808 EP 810 DI 10.1107/S0108270100006168 PN 7 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 333RQ UT WOS:000088144900028 PM 10935088 ER PT J AU Lin, DW Manning, NO Jiang, JS Abola, EE Stampf, D Prilusky, J Sussman, JL AF Lin, DW Manning, NO Jiang, JS Abola, EE Stampf, D Prilusky, J Sussman, JL TI AutoDep: a web-based system for deposition and validation of macromolecular structural information SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID PROTEIN-DATA-BANK; CRYSTALLOGRAPHY; REFINEMENT; PROGRAM; ERRORS; FILE; NMR AB This paper describes the design and full implementation of a new concept in data deposition and validation: AutoDep (copyright Brookhaven Science Associates LLC). AutoDep changes the traditional procedure for data acceptance and validation of the primary databases into an interactive depositor-driven operation which almost eliminates the delay between the acceptance of the data and its public release. The system takes full advantage of the knowledge and expertise of the experimenters, rather than relying on the database curators for the complete and accurate description of the structural experiment and its results. AutoDep, developed by the Protein Data Bank at Brookhaven National Laboratory (BNL) as a flexible and portable system, has already been adopted by other primary databases and implemented on different platforms/operating systems. AutoDep was introduced at BNL in 1996 [see Manning (1996), Protein Data Bank Quart. Newslett. 77, 2 (ftp://ftp.rcsb.org/pub/pdb/doc/newsletters/bnl/newsletter96jul/newslttr.txt); Manning (1996), Protein Data Bank Quart. Newslett. 78, 2 (ftp://ftp.rcsb.org/pub/pdb/doc/newsletters/bnl/newsletter96oct/newslttr.txt)]. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Brookhaven Natl Lab, Div Informat Technol, Upton, NY 11973 USA. Weizmann Inst Sci, Bioinformat Unit, IL-76100 Rehovot, Israel. Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. RP Sussman, JL (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 25 TC 13 Z9 13 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUL PY 2000 VL 56 BP 828 EP 841 DI 10.1107/S0907444900005655 PN 7 PG 14 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 327FY UT WOS:000087784500007 PM 10930830 ER PT J AU Boggon, TJ Helliwell, JR Judge, RA Olczak, A Siddons, DP Snell, EH Stojanoff, V AF Boggon, TJ Helliwell, JR Judge, RA Olczak, A Siddons, DP Snell, EH Stojanoff, V TI Synchrotron X-ray reciprocal-space mapping, topography and diffraction resolution studies of macromolecular crystal quality SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID EGG-WHITE LYSOZYME; BRAGG REFLECTION PROFILES; CCD VIDEO OBSERVATION; TETRAGONAL LYSOZYME; PROTEIN CRYSTALLIZATION; GROWTH-KINETICS; MICROGRAVITY CRYSTALLIZATION; PERFECTION; IMPURITIES; CONVECTION AB A comprehensive study of microgravity and ground-grown chicken egg-white lysozyme crystals is presented using synchrotron X-ray reciprocal-space mapping, topography techniques and diffraction resolution. Microgravity crystals displayed reduced intrinsic mosaicities on average, but no differences in terms of strain over their ground-grown counterparts. Topographic analysis revealed that in the microgravity case the majority of the crystal was contributing to the peak of the reflection at the appropriate Bragg angle. In the ground-control case only a small volume of the crystal contributed to the intensity at the diffraction peak. The techniques prove to be highly complementary, with the reciprocal-space mapping providing a quantitative measure of the crystal mosaicity and strain (or variation in lattice spacing) and the topography providing a qualitative overall assessment of the crystal in terms of its X-ray diffraction properties. Structural data collection was also carried out at the synchrotron. C1 Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. ESRF, Grenoble, France. NASA, Struct Biol Lab, Huntsville, AL 35812 USA. Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England. RP Siddons, DP (reprint author), Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. EM siddons@bnl.gov RI stojanoff, vivian /I-7290-2012; Helliwell, John /C-4587-2014; OI stojanoff, vivian /0000-0002-6650-512X; Helliwell, John /0000-0002-0520-7540; Olczak, Andrzej/0000-0002-5433-1767 NR 67 TC 47 Z9 47 U1 0 U2 11 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUL PY 2000 VL 56 BP 868 EP 880 DI 10.1107/S0907444900005837 PN 7 PG 13 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 327FY UT WOS:000087784500010 PM 10930833 ER PT J AU Myers, WD Swiatecki, WJ AF Myers, WD Swiatecki, WJ TI The dragon guarding the island of superheavy nuclei has dropped his shield SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT Kazimierz Grotowski 70th Birthday Symposium on Phases of Nuclear Matter CY JAN 27-28, 2000 CL JAGELLONIAN UNIV, KRAKOW, POLAND SP Jagellonian Univ, M Smoluchowski Inst Phys, H Niewodniczanski Inst Nuclear Phys HO JAGELLONIAN UNIV AB The unexpectedly large cross-section reported for the reaction Kr-86 + (208)pb = (293)118 + n may be due to the lowering of the Coulomb barrier (measured with reference to the energy of the compound nucleus). Some consequences of this "unshielding" phenomenon are discussed. C1 Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Myers, WD (reprint author), Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD JUL PY 2000 VL 31 IS 7 BP 1471 EP 1478 PG 8 WC Physics, Multidisciplinary SC Physics GA 338TL UT WOS:000088435300004 ER PT J AU Torney, DC AF Torney, DC TI Binary cumulants SO ADVANCES IN APPLIED MATHEMATICS LA English DT Article AB The binary cumulant is defined fur joint probability distributions on binary sequences of finite length. Tnt: binary cumulant is bounded, in magnitude, by unity, and is shown to vanish if there exists any bipartition of the letter positions into statistically independent blocks. Probability distributions on binary n-sequences are shown to map injectively into their binary cumulants for all subsets of the set of letter positions. An inversion algorithm is established, recovering the joint distribution from its collection of binary cumulants. (C) 2000 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Torney, DC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Mail Stop K710, Los Alamos, NM 87545 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0196-8858 J9 ADV APPL MATH JI Adv. Appl. Math. PD JUL PY 2000 VL 25 IS 1 BP 34 EP 40 DI 10.1006/aama.2000.0692 PG 7 WC Mathematics, Applied SC Mathematics GA 343CK UT WOS:000088684000003 ER PT J AU Hahn, DW Lunden, MM AF Hahn, DW Lunden, MM TI Detection and analysis of aerosol particles by laser-induced breakdown spectroscopy SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID INDUCED PLASMA SPECTROSCOPY; MASS-SPECTROMETRY; ONLINE AB Laser-induced breakdown spectroscopy (LIBS) was evaluated as a means for quantitative analysis of the size, mass, and composition of individual micron-to submicron-sized aerosol particles over a range of well-characterized experimental conditions. Conditional data analysis ass used to identify LIES spectra that correspond to discrete aerosol particles under low aerosol particle loadings. The size distributions of monodisperse particle source flows were measured using the LIES technique for calcium- and magnesium-based aerosols. The resulting size distributions were in good agreement with independently measured size distribution data. A lower size detection limit of 175 nm was determined for the calcium- and magnesium-based particles, which corresponds to a detectable mass of approximately. 3 femtograms. In addition, the accuracy of the LIES technique for the interference-free analysis of different particle types was verified using a binary aerosol system of calcium-based and chromium particles. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Livermore, CA USA. RP Hahn, DW (reprint author), Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. NR 31 TC 117 Z9 122 U1 4 U2 16 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD JUL-AUG PY 2000 VL 33 IS 1-2 BP 30 EP 48 DI 10.1080/027868200410831 PG 19 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 330HM UT WOS:000087956800004 ER PT J AU Reilly, PTA Lazar, AC Gieray, RA Whitten, WB Ramsey, JM AF Reilly, PTA Lazar, AC Gieray, RA Whitten, WB Ramsey, JM TI The elucidation of charge-transfer-induced matrix effects in environmental aerosols via real-time aerosol mass spectral analysis of individual airborne particles SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID LASER-DESORPTION IONIZATION; CHEMICAL-ANALYSIS; SPECTROMETRY; DESORPTION/IONIZATION; SIZE; MICROPARTICLES; SPECIATION AB Matrix effects in real-time aerosol mass spectrometry (RTAMS) were investigated using Standard Reference Materials (SRMs) obtained from the National Institute of Standards and Technology (NIST). Suppression of major component ions by much less concentrated species was observed. Attempts were made to mimic the ion suppression using binary systems but were unsuccessful. Data are presented that suggest the origin of the matrix effect is charge transfer induced neutralization in the ablation plume. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Reilly, PTA (reprint author), Oak Ridge Natl Lab, POB 2008,M-S 6142, Oak Ridge, TN 37831 USA. NR 27 TC 70 Z9 72 U1 0 U2 8 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD JUL-AUG PY 2000 VL 33 IS 1-2 BP 135 EP 152 DI 10.1080/027868200410895 PG 18 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 330HM UT WOS:000087956800010 ER PT J AU Pinter, PJ Kimball, BA Wall, GW LaMorte, RL Hunsaker, DJ Adamsen, FJ Frumau, KFA Vugts, HF Hendrey, GR Lewin, KF Nagy, J Johnson, HB Wechsunge, F Leavitt, SW Thompson, TL Matthias, AD Brooks, TJ AF Pinter, PJ Kimball, BA Wall, GW LaMorte, RL Hunsaker, DJ Adamsen, FJ Frumau, KFA Vugts, HF Hendrey, GR Lewin, KF Nagy, J Johnson, HB Wechsunge, F Leavitt, SW Thompson, TL Matthias, AD Brooks, TJ TI Free-air CO2 enrichment (FACE): blower effects on wheat canopy microclimate and plant development SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE wheat; Triticum aestivum; carbon dioxide; climate change; microclimate; canopy temperatures; canopy reflectance; leaf wetness ID CARBON-DIOXIDE ENRICHMENT; WATER-USE; GROWTH; RESPIRATION; SYSTEM; PHOTOSYNTHESIS; EVAPOTRANSPIRATION; CONDUCTANCE; ENVIRONMENT; MOISTURE AB Free-air carbon dioxide enrichment (FACE) provides a realistic, cost-effective method for evaluating the effects of supra-ambient CO2 concentrations on growth, development, yield, and water use of agricultural crops and natural ecosystems with very few of the problems normally associated with glasshouse or chamber type research. There are no walls interfering with incident radiation and no artificial constraints on rooting depth. With current FACE technology, CO2 enriched air is injected around the perimeter of circular plots and natural wind disperses the CO2 across the experimental area. Under stable, night-time wind conditions found in FACE wheat experiments at Maricopa, Arizona, the blowers used to inject CO2 exerted subtle effects on the microclimate in a manner analogous to wind machines used for orchard frost protection. Plots equipped with blowers had nighttime foliage and air temperatures that averaged 0.6-1.0 degrees C warmer than controls without blowers. A secondary effect of these elevated temperatures was that plots equipped with blowers displayed differences in dew duration (time that leaves were wet was reduced 30%), plant development (anthesis occurred 4 days earlier), and senescence [as measured with the normalized difference vegetation index (NDVI)]. Natural wind and turbulence appear to overcome the blower effect during daytime treatments and on some nights. Aerial thermal imagery (8-12 mu m) acquired during the 1998 FACE experiment with grain sorghum provided additional evidence of the blower effect on canopy temperatures. Since increased plant tissue temperatures also occur when elevated CO2 induces partial stomatal closure and reduces transpiration, not all instances of canopy temperature elevation in CO2 enriched plots can be ascribed solely to the presence of blowers. It is concluded that proper controls for FACE facilities should have similar air hows to those used in the FACE plots. Advantages and disadvantages to nighttime CO2 enrichment are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 USDA ARS, US Water Conservat Lab, Phoenix, AZ 85040 USA. Vrije Univ Amsterdam, NL-1081 HV Amsterdam, Netherlands. Brookhaven Natl Lab, Long Isl, NY USA. USDA ARS, Grassland Soil & Water Res Lab, Temple, TX 76502 USA. Potsdam Inst Climate Impact Res, Potsdam, Germany. Univ Arizona, Tree Ring Res Lab, Tucson, AZ USA. Univ Arizona, Dept Soil Water & Environm Sci, Tucson, AZ USA. Univ Arizona, Maricopa Agr Ctr, Maricopa, AZ USA. RP Pinter, PJ (reprint author), USDA ARS, US Water Conservat Lab, 4331 E Broadway Rd, Phoenix, AZ 85040 USA. NR 38 TC 64 Z9 71 U1 5 U2 29 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD JUL 1 PY 2000 VL 103 IS 4 BP 319 EP 333 DI 10.1016/S0168-1923(00)00150-7 PG 15 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 323EX UT WOS:000087553100001 ER PT J AU Novitsky, VA Gaolekwe, S McLane, MF Ndung'u, TP Foley, BT Vannberg, F Marlink, R Essex, M AF Novitsky, VA Gaolekwe, S McLane, MF Ndung'u, TP Foley, BT Vannberg, F Marlink, R Essex, M TI HIV type 1 A/J recombinant with a pronounced pol gene mosaicism SO AIDS RESEARCH AND HUMAN RETROVIRUSES LA English DT Article ID IMMUNODEFICIENCY-VIRUS; SUBTYPE-C; IDENTIFICATION; CLONES; REGION AB A nearly full-length genome sequence of a novel HIV-1 A/J recombinant with a complex structure of the pol gene has been analyzed. This virus was isolated in 1998 from a 35-year-old female from Botswana. The virus demonstrated a dual pattern for CXCR4/CCR5 coreceptor utilization. Using short-term enrichment of the donor's PBMCs, the 98BW21 isolate was long-range amplified, cloned, and sequenced. The sequence of the clone 98BW21.17 spanned 9103 bp from the PBS site to the U5 region of the 3' LTR. The phylogenetic relationship of the 98BW21.17 clone to HIV-1 sequences represented by M, N, and O groups and A-K subtypes of the M group was examined across the entire viral genome. The 98BW21.17 clone demonstrated a unique phylogenetic topology clustering within subtype A or subtype J reference sequences. However, the subtype origin of two regions within the pol gene (p51 RT and integrase) could not be identified. Recombination patterns of the 98BW21.17 clone were different from known AGJ/AGIJ-type viruses such as isolates BFP90 and 95ML84. This study demonstrated the existence and replication competence of a new dual-tropic X4/R5 recombinant form of HIV-1 on the subtype J backbone. The nucleotide sequence of the 98BW21.17 clone was submitted to GenBank under accession number AF192135. C1 Harvard Univ, Sch Publ Hlth, Dept Immunol & Infect Dis, Boston, MA 02115 USA. Princess Marina Hosp, Blood Bank Unit, Gaborone, Botswana. Univ Calif Los Alamos Natl Lab, Grp T10, Los Alamos, NM 87545 USA. RP Novitsky, VA (reprint author), Harvard Univ, Sch Publ Hlth, Dept Immunol & Infect Dis, FXB-310,651 Huntington Ave, Boston, MA 02115 USA. OI Foley, Brian/0000-0002-1086-0296 FU FIC NIH HHS [D43TW00004]; NCI NIH HHS [R35CA39805] NR 18 TC 17 Z9 17 U1 0 U2 0 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 0889-2229 J9 AIDS RES HUM RETROV JI Aids Res. Hum. Retrovir. PD JUL PY 2000 VL 16 IS 10 BP 1015 EP 1020 DI 10.1089/08892220050058434 PG 6 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 331FH UT WOS:000088006300010 PM 10890363 ER PT J AU Dupree-Ellis, E Watkins, J Ingle, JN Phillips, J AF Dupree-Ellis, E Watkins, J Ingle, JN Phillips, J TI External radiation exposure and mortality in a cohort of uranium processing workers SO AMERICAN JOURNAL OF EPIDEMIOLOGY LA English DT Article DE kidney; mortality; neoplasms, radiation-induced; occupational exposure; radiation, ionizing; risk ID CANCER MORTALITY; GOLD MINERS; NUCLEAR; EMPLOYEES; MORBIDITY; SILICA; PLANT AB In a study of 2,514 White male workers employed between 1942 and 1966 at a US uranium processing plant, mortality was compared with overall US mortality, and the relation between external ionizing radiation and cancer was evaluated. Through 1993, 1,013 deaths occurred. The mean cumulative dose was 47.8 mSv. The standardized mortality ratio (SMR) was 0.90 for all causes of death and 1.05 for all cancers. Many cancer sites had elevated SMRs, Among nonmalignant outcomes, the SMR for chronic nephritis was 1.88 (six deaths observed). An excess relative risk estimate of 10.5 per Sv (10 cases) was observed for kidney cancer; this may have resulted from chance, internal radiation, or chemical exposures not considered. C1 Oak Ridge Associated Univ, Ctr Epidemiol Res, Oak Ridge, TN 37830 USA. Delta 21 Resources Inc, Oak Ridge, TN USA. RP Dupree-Ellis, E (reprint author), Oak Ridge Associated Univ, Ctr Epidemiol Res, POB 117,MS 45, Oak Ridge, TN 37830 USA. FU PHS HHS [200-93-2695] NR 23 TC 29 Z9 30 U1 0 U2 2 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0002-9262 J9 AM J EPIDEMIOL JI Am. J. Epidemiol. PD JUL 1 PY 2000 VL 152 IS 1 BP 91 EP 95 DI 10.1093/aje/152.1.91 PG 5 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 331TV UT WOS:000088035500013 PM 10901334 ER PT J AU Zolotorev, MS McDonald, KT AF Zolotorev, MS McDonald, KT TI Diffraction as a consequence of Faraday's law SO AMERICAN JOURNAL OF PHYSICS LA English DT Article C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08544 USA. RP Zolotorev, MS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD JUL PY 2000 VL 68 IS 7 BP 674 EP 675 DI 10.1119/1.19511 PG 2 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 326VF UT WOS:000087757100013 ER PT J AU Kalinichev, AG Kirkpatrick, RJ Cygan, RT AF Kalinichev, AG Kirkpatrick, RJ Cygan, RT TI Molecular modeling of the structure and dynamics of the interlayer and surface species of mixed-metal layered hydroxides: Chloride and water in hydrocalumite (Friedel's salt) SO AMERICAN MINERALOGIST LA English DT Article ID ELECTROSTATIC POTENTIALS; ATOMIC CHARGES; MONTE-CARLO; SIMULATIONS; MONTMORILLONITE; HYDROTALCITE; TRANSITIONS; HYDRATION; BINDING; ANIONS AB The dynamical behavior of Cl(-) and H(2)O molecules in the interlayer and on the (001) surface of the Ca-aluminate hydrate hydrocalumite (Friedel's salt) over a range of temperatures from -100 to 300 degrees C was studied using isothermal-isobaric molecular dynamics computer simulations. This phase is currently the best available model compound for other, typically more disordered, mixed-metal layered hydroxides. The computed crystallographic parameters and density are in good agreement with available X-ray diffraction data and the force field developed for these simulations preserves the structure and density to within less than 2% of their measured values. In contrast to the highly ordered arrangement of the interlayer water molecules interpreted from the X-ray data, the simulations reveal significant dynamic disorder in water orientations. At all simulated temperatures, the interlayer water molecules undergo rapid librations (hindered hopping rotations) around an axis essentially perpendicular to the layers. This results in breaking and reformation of hydrogen bonds with the neighboring Cl(-) anions and in a time-averaged nearly uniaxial symmetry at Cl(-), in good agreement with recent (35)Cl NMR measurements. Power spectra of translational, librational, and vibrational motions of interlayer and surface Cl(-) and H(2)O were calculated as Fourier transforms of the atomic velocity autocorrelation functions and compared with the corresponding spectra and dynamics for a bulk aqueous solution. The ordered interlayer space has significant effects on the motions. Strong electrostatic attraction between interlayer water molecules and Ca atoms in the principal layer makes the Ca ... OH(2) bond direction the preferred axis for interlayer water librations. The calculated diffusion coefficient of Cl(-) as an outer-sphere surface complex is almost three times that of inner-sphere Cl(-), but is still about an order of magnitude less than that of Cl(-) in bulk aqueous solution at the same temperature. C1 Univ Illinois, Dept Geol, Urbana, IL 61801 USA. Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. RP Kalinichev, AG (reprint author), Univ Illinois, Dept Geol, 1301 W Green St, Urbana, IL 61801 USA. EM audreyk@hercules.geology.uiuc.edu RI Kalinichev, Andrey/B-4519-2008; Chen, Wei/A-5694-2010 OI Kalinichev, Andrey/0000-0003-0743-4242; NR 37 TC 66 Z9 67 U1 3 U2 18 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JUL-AUG PY 2000 VL 85 IS 7-8 BP 1046 EP 1052 PG 7 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 330MH UT WOS:000087965500020 ER PT J AU Sanderson, JG AF Sanderson, JG TI Testing ecological patterns SO AMERICAN SCIENTIST LA English DT Article ID DARWIN FINCHES; PHYLOGENY C1 Univ Calif Los Alamos Natl Lab, Comp Applicat Grp, Los Alamos, NM 87545 USA. RP Sanderson, JG (reprint author), Univ Calif Los Alamos Natl Lab, Comp Applicat Grp, Mail Stop B-256, Los Alamos, NM 87545 USA. NR 16 TC 33 Z9 34 U1 0 U2 3 PU SIGMA XI-SCI RES SOC PI RES TRIANGLE PK PA PO BOX 13975, RES TRIANGLE PK, NC 27709 USA SN 0003-0996 J9 AM SCI JI Am. Scientist PD JUL-AUG PY 2000 VL 88 IS 4 BP 332 EP 339 DI 10.1511/2000.29.883 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 323JY UT WOS:000087563300017 ER PT J AU Thomas, EV AF Thomas, EV TI Adaptable multivariate calibration models for spectral applications SO ANALYTICAL CHEMISTRY LA English DT Article AB Multivariate calibration techniques have been used in a wide variety of spectroscopic situations. In many of these situations, spectral variation can be partitioned into separate classes, For example, suppose that multiple spectra are obtained from each of a number of different objects wherein the level of the analyte of interest varies within each object over time. In such situations, the total spectral variation observed across all measurements has two distinct general sources of variation: intraobject and interobject. One might want to develop a global multivariate calibration model that predicts the analyte of interest accurately both within and across objects, including new objects not involved in developing the calibration model. However, this goal might be hard to realize if the interobject spectral variation is complex and difficult to model. If the intraobject spectral variation is consistent across objects, an effective alternative approach might be to develop a generic intraobject model that can be adapted to each object separately. This paper contains recommendations for experimental protocols and data analysis in such situations. The approach is illustrated with an example involving the noninvasive measurement of glucose using near-infrared reflectance spectroscopy. Extensions to calibration maintenance and calibration transfer are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Thomas, EV (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 18 Z9 18 U1 1 U2 3 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 JUL 1 PY 2000 VL 72 IS 13 BP 2821 EP 2827 DI 10.1021/ac000009j PG 7 WC Chemistry, Analytical SC Chemistry GA 329YW UT WOS:000087936900036 ER PT J AU Grate, JW Zellers, ET AF Grate, JW Zellers, ET TI The fractional free volume of the sorbed vapor in modeling the viscoelastic contribution to polymer-coated surface acoustic wave vapor sensor responses SO ANALYTICAL CHEMISTRY LA English DT Article ID THICKNESS-SHEAR-MODE; PARTITION-COEFFICIENTS; CHEMICAL MEASUREMENTS; MASS; DEVICES; RESONATORS; COATINGS; DESIGN; FILMS AB Surface acoustic wave (SAW) vapor sensors with polymeric sorbent layers can respond to vapors on the basis of mass loading and modulus decreases of the polymer film. The modulus changes are associated with volume changes that occur as vapor is sorbed by the film. A factor based on the fractional free volume of the vapor as a liquid has been incorporated into a model for the contribution of swelling-induced modulus changes to observed SAW vapor sensor responses. In this model, it is not the entire volume added to the film by the vapor that contributes to the modulus effect; it is the fractional free volume associated with the vapor molecules that causes the modulus to decrease in a manner that is equivalent to free volume changes from thermal expansion. The amplification of the SAW vapor sensor response due to modulus effects that are predicted by this model has been compared to amplification factors determined by comparing the responses of polymer-coated SAW vapor sensors with the responses of similarly coated thickness shear mode (TSM) vapor sensors, the latter being gravimetric. Results for six to eight vapors on each of two polymers, poly(isobutylene) and poly(epichlorohydrin), were examined. The model predicts amplification factors of the order of about 1.5-3, and vapor-dependent variations in the amplification factors are related to the specific volume of the vapor as a liquid. The fractional free volume factor provides a physically meaningful addition to the model and is consistent with conventional polymer physics treatments of the effects of temperature and plasticization on polymer modulus. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Michigan, Dept Environm Hlth Sci, Ann Arbor, MI 48109 USA. RP Grate, JW (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. FU NIOSH CDC HHS [R01-OH03692] NR 46 TC 47 Z9 49 U1 1 U2 6 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 JUL 1 PY 2000 VL 72 IS 13 BP 2861 EP 2868 DI 10.1021/ac991192n PG 8 WC Chemistry, Analytical SC Chemistry GA 329YW UT WOS:000087936900042 PM 10905319 ER PT J AU Shortreed, MR Li, HL Huang, WH Yeung, ES AF Shortreed, MR Li, HL Huang, WH Yeung, ES TI High throughput single-molecule DNA screening based be electrophoresis SO ANALYTICAL CHEMISTRY LA English DT Article ID FLUORESCENCE CORRELATION SPECTROSCOPY; CAPILLARY-ELECTROPHORESIS; PCR; RNA AB In electrophoresis, the migration velocity is used for sizing DNA and proteins or for distinguishing molecules based on charge and hydrodynamic radius. Many protein and DNA assays relevant to disease diagnosis are based on such separations. However, standard protocols are not only slow (minutes to hours) but also insensitive (many molecules in a detectable band). We successfully demonstrated a high-throughput imaging approach that allows determination of the individual electrophoretic mobilities of many molecules at a time. Each measurement only requires a few milliseconds to complete. This opens up the possibility of screening single copies of DNA or proteins within single biological cells for disease markers without performing polymerase chain reaction or other biological amplification. The purpose is not to separate the DNA molecules but to identify each one on the basis of the measured electrophoretic mobility. We developed three different procedures to measure the individual molecular mobilities. The results correlate well with capillary electrophoresis (CE) experiments for the same samples (2-49 kb dsDNA) under identical separation conditions. The implication is that any electrophoresis protocols from slab gels to CE should be adaptable to single-molecule screening for disease diagnosis. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 22 TC 69 Z9 69 U1 0 U2 7 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 JUL 1 PY 2000 VL 72 IS 13 BP 2879 EP 2885 DI 10.1021/ac991428n PG 7 WC Chemistry, Analytical SC Chemistry GA 329YW UT WOS:000087936900045 PM 10905322 ER PT J AU Khandurina, J McKnight, TE Jacobson, SC Waters, LC Foote, RS Ramsey, JM AF Khandurina, J McKnight, TE Jacobson, SC Waters, LC Foote, RS Ramsey, JM TI Integrated system for rapid PCR-based DNA analysis in microfluidic devices SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYMERASE-CHAIN-REACTION; X-RAY-LITHOGRAPHY; CAPILLARY-ELECTROPHORESIS; MICROCHIP PCR; AMPLIFICATION; SEPARATIONS; FABRICATION; PERFORMANCE; INSTRUMENT; MOLECULES AB An integrated system for rapid PCR-based analysis on a microchip has been demonstrated. The system couples a compact thermal cycling assembly based on dual Peltier thermoelectric elements with a microchip gel electrophoresis platform. This configuration allows fast(similar to 1 min/cycle) and efficient DNA amplification on-chip followed by electrophoretic sizing and detection on the same chip. An on-chip DNA concentration technique has been incorporated into the system to further reduce analysis time by decreasing the number of thermal cycles required. The concentration injection scheme enables detection of PCR products after performing as few as 10 thermal cycles, with a total analysis time of less than 20 min. The starting template copy number was less than 15 per injection volume. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Ramsey, JM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. RI McKnight, Tim/H-3087-2011 OI McKnight, Tim/0000-0003-4326-9117 NR 31 TC 404 Z9 422 U1 8 U2 107 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 JUL 1 PY 2000 VL 72 IS 13 BP 2995 EP 3000 DI 10.1021/ac991471a PG 6 WC Chemistry, Analytical SC Chemistry GA 329YW UT WOS:000087936900063 PM 10905340 ER PT J AU Miyabe, K Guiochon, G AF Miyabe, K Guiochon, G TI Kinetic study of the concentration dependence of the mass transfer rate coefficient in enantiomeric separation on a polymeric imprinted stationary phase SO ANALYTICAL SCIENCES LA English DT Article ID BOVINE SERUM-ALBUMIN; SURFACE-DIFFUSION; LATERAL DIFFUSION; CELLULOSE TRIACETATE; LIGHT-SCATTERING; PORE DIFFUSION; TROGERS BASE; CHROMATOGRAPHY; INTERFACE; ADSORPTION AB Kinetic data previously acquired on the enantiomeric separation of L- and D-phenylalanine anilide (PA) on a polymeric stationary phase imprinted with L-PA were reinterpreted. The parameters characterizing the mass transport processes active in the column, i.e., axial dispersion, fluid-to-particle mass transfer, intraparticle diffusion, and adsorption/desorption were calculated. Intraparticle diffusion was shown to have a dominant contribution to band broadening. The surface diffusion coefficient (D-s) showed a positive concentration dependence which could explain the dependence of the lumped mass transfer rate coefficient on the enantiomer concentration. It is likely that the positive concentration dependence of D-s could be explained by the heterogeneity of the surface of the stationary phase and that the distribution of adsorption energy on the surface of the imprinted polymer has an exponential decay profile. 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 44 TC 17 Z9 17 U1 0 U2 3 PU JAPAN SOC ANALYTICAL CHEMISTRY PI TOKYO PA 26-2 NISHIGOTANDA 1 CHOME SHINAGAWA-KU, TOKYO, 141, JAPAN SN 0910-6340 J9 ANAL SCI JI Anal. Sci. PD JUL PY 2000 VL 16 IS 7 BP 719 EP 730 DI 10.2116/analsci.16.719 PG 12 WC Chemistry, Analytical SC Chemistry GA 339CT UT WOS:000088460600007 ER PT J AU Amthor, JS AF Amthor, JS TI The McCree-de Wit-Penning de Vries-Thornley respiration paradigms: 30 years later SO ANNALS OF BOTANY LA English DT Review DE review; growth; history; maintenance; model; paradigm; respiration ID LEAF DARK RESPIRATION; NORWAY SPRUCE TREES; MAINTENANCE RESPIRATION; ROOT RESPIRATION; CARBON BALANCE; NITROGEN-CONTENT; ELEVATED CO2; WHITE CLOVER; ENERGY-REQUIREMENTS; ONTOGENETIC CHANGES AB To grow, an organism must respire substrates to produce C-skeleton intermediates, usable energy (i.e. ATP), and reducing power [i.e. NAD(P)H] to support biosynthesis and related processes such as active transport of substrates. Respiration is also needed-mainly as a supplier of ATP-to maintain existing biomass in a functional state. As a result, quantifying links between respiration. growth, and maintenance are needed to assess potential plant productivity, to understand plant responses to environmental factors, and as the basis of cost-benefit analyses of alternative uses of photosynthate. Beginning 30 pears ago, and continuing for about 5 years, rapid advances were made in understanding and quantifying relationships between respiration and the processes it supports. Progress has continued since then. though often as refinements rather than novel advances. The simplest framework (i.e. paradigm) for relating respiration to other processes divides respiration into growth and maintenance fractions. This often involves a combination of empiricism and mechanism. A three-component framework (growth, maintenance and wastage) has also been considered, although quantifying wastage (theoretically or empirically) remains problematic. The more general and flexible framework, called the general paradigm (GP, herein), relates respiration to any number of individual processes that it supports. The most important processes (from C and energy balance perspectives) identified to date that require respiration are: biosynthesis of new structural biomass, translocation of photosynthate from sources to sinks, uptake of ions from the soil solution, assimilation of N (including N-2) and S into organic compounds, protein turnover, and cellular ion-gradient maintenance. In addition, some part of respiration may be associated with wastage (e.g. futile cycles and mitochondrial electron transport uncoupled from oxidative phosphorylation). Most importantly, the GP can (semi-)mechanistically relate respiration to underlying physiology and biochemistry. The GP is more complicated than other approaches to describing or modelling respiration because it is more realistic, complete and mechanistic. This review describes a history of the GP and its present state. Future research questions are suggested. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Amthor, JS (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Mail Stop 6422,POB 2008, Oak Ridge, TN 37831 USA. RI Amthor, Jeffrey/F-2696-2016 OI Amthor, Jeffrey/0000-0002-1410-6100 NR 161 TC 378 Z9 417 U1 6 U2 86 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-7364 J9 ANN BOT-LONDON JI Ann. Bot. PD JUL PY 2000 VL 86 IS 1 BP 1 EP 20 DI 10.1006/anbo.2000.1175 PG 20 WC Plant Sciences SC Plant Sciences GA 332AF UT WOS:000088050300001 ER PT J AU Lyness, JN AF Lyness, JN TI A brief survey of extrapolation quadrature SO ANZIAM JOURNAL LA English DT Article AB This is a short precis of a presentation on some of the recent advances in the area of extrapolation quadrature; given at David Elliott's 65th birthday conference in Hobart in February 1997. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ New S Wales, Sch Math, Kensington, NSW 2033, Australia. RP Lyness, JN (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AUSTRALIAN MATHEMATICS PUBL ASSOC INC PI CANBERRA PA MATHEMATICS DEPT AUSTRALIAN NATIONAL UNIV, CANBERRA, ACT 0200, AUSTRALIA SN 1442-4436 J9 ANZIAM J JI Anziam J. PD JUL PY 2000 VL 42 BP 181 EP 184 PN 1 PG 4 WC Mathematics, Applied SC Mathematics GA 357HN UT WOS:000089492600018 ER PT J AU Dunbar, J Ticknor, LO Kuske, CR AF Dunbar, J Ticknor, LO Kuske, CR TI Assessment of microbial diversity in four southwestern United States soils by 16S rRNA gene terminal restriction fragment analysis SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID GRADIENT GEL-ELECTROPHORESIS; POLYMERASE CHAIN-REACTION; RIBOSOMAL-RNA SEQUENCES; ENRICHMENT CULTURES; DNA FRAGMENTS; COMMUNITIES; AMPLIFICATION; BACTERIOPLANKTON; POPULATIONS; BACTERIA AB The ability of terminal restriction fragment (T-RFLP or TRF) profiles of 165 rRNA genes to provide useful information about the relative diversity of complex microbial communities was investigated by comparison with other methods. Four soil communities representing two pinyon rhizosphere and two between-tree (interspace) soil environments were compared by analysis of 16S rRNA gene clone libraries and culture collections (Dunbar et al., Appl. Environ. Microbiol. 65:1662-1669, 1998) and by analysis of 16S rDNA TRF profiles of community DNA. The TRF method was able to differentiate the four communities in a manner consistent with previous comparisons of the communities by analysis of 16S rDNA clone libraries. TRF profiles were not useful for calculating and comparing traditional community richness or evenness values among the four soil environments. Statistics calculated from RsaI, NhaI, HaeIII, and MspI profiles of each community were inconsistent, and the combined data were not significantly different between samples. The detection sensitivity of the method was tested. In standard PCRs, a seeded population comprising 0.1 to 1% of the total community could be detected. The combined results demonstrate that TRF analysis is an excellent method for rapidly comparing the relationships between bacterial communities in environmental samples. However, for highly complex communities, the method appears unable to provide classical measures of relative community diversity. C1 Univ Calif Los Alamos Natl Lab, Environm Mol Biol Grp, Biosci Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Technol & Safety Assessment Div, Los Alamos, NM 87545 USA. RP Kuske, CR (reprint author), Univ Calif Los Alamos Natl Lab, Environm Mol Biol Grp, Biosci Div, M888, Los Alamos, NM 87545 USA. RI Ducey, Thomas/A-6493-2011 NR 29 TC 287 Z9 331 U1 3 U2 46 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUL PY 2000 VL 66 IS 7 BP 2943 EP 2950 DI 10.1128/AEM.66.7.2943-2950.2000 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 332DE UT WOS:000088057600034 PM 10877790 ER PT J AU Sharma, PK Balkwill, DL Frenkel, A Vairavamurthy, MA AF Sharma, PK Balkwill, DL Frenkel, A Vairavamurthy, MA TI A new Klebsiella planticola strain (Cd-1) grows anaerobically at high cadmium concentrations and precipitates cadmium sulfide SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID X-RAY-ABSORPTION; ESCHERICHIA-COLI; RESISTANT; BACTERIA; CULTURE AB Heavy metal resistance by bacteria is a topic of much importance to the bioremediation of contaminated soils and sediments. We report here the isolation of a highly cadmium-resistant Klebsiella planticola strain, Cd-1, from reducing salt marsh sediments. The strain grows in up to 15 mM CdCl2 under a wide range of NaCl concentrations and at acidic or neutral pH. In growth medium amended with thiosulfate, it precipitated significant amounts of cadmium sulfide (CdS), as confirmed by x-absorption spectroscopy. In comparison with various other strains tested, Cd-1 is superior for precipitating CdS in cultures containing thiosulfate. Thus, our results suggest that Cd-1 is a good candidate for the accelerated bioremediation of systems contaminated by high levels of cadmium. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA. RP Vairavamurthy, MA (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Bldg 815, Upton, NY 11973 USA. RI Frenkel, Anatoly/D-3311-2011 OI Frenkel, Anatoly/0000-0002-5451-1207 NR 23 TC 42 Z9 46 U1 1 U2 12 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUL PY 2000 VL 66 IS 7 BP 3083 EP 3087 DI 10.1128/AEM.66.7.3083-3087.2000 PG 5 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 332DE UT WOS:000088057600054 PM 10877810 ER PT J AU Carrado, KA AF Carrado, KA TI Synthetic organo- and polymer-clays: preparation, characterization, and materials applications SO APPLIED CLAY SCIENCE LA English DT Review DE hectorite; crystallization; polymer-clays; mesoporosity; nanocomposites; catalysis ID NYLON 6-CLAY HYBRID; LAYERED SILICATES; MESOPOROUS SILICA; HYDROTHERMAL CRYSTALLIZATION; INORGANIC NANOCOMPOSITES; COMPOSITES; HYDRODESULFURIZATION; INTERCALATION; COMPLEXES; MECHANISM AB We have over the years developed and patented a general technique for the hydrothermal synthesis of clay minerals in the presence of organic, organometallic, and polymeric intercalants. This review will summarize the details for crystallization of modified hectorites along with their characterization and materials applications. Among the several potential uses of these synthetic materials, there are two important applications concerning catalysis and composites. The fate of the template dictates which of these applications is pertinent. First, if the organic molecule or polymer is used with the intention of acting as templates of pore structure, then the organic template is removed after the modified clay has been crystallized Upon template removal, the now porous materials are examined for their use as potential catalysts and catalyst supports. We have recently proven a correlation between catalyst pore size in the mesoporous range and the size and concentration of a polymeric template that is used. Preliminary hydrodesulfurization catalytic results have been obtained using these materials. If, on the other hand, intercalants are allowed to remain as a part of the structure, then a distinctive class of organic-inorganic composites becomes possible. When polymeric intercalants are used, especially at high concentrations, the materials have relevance to nanocomposite applications. Work in this area has focused on incorporating polymers at higher than 85 wt.% of the nanocomposite. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. EM kcarrado@anl.gov NR 79 TC 249 Z9 270 U1 10 U2 86 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-1317 EI 1872-9053 J9 APPL CLAY SCI JI Appl. Clay Sci. PD JUL PY 2000 VL 17 IS 1-2 BP 1 EP 23 DI 10.1016/S0169-1317(00)00005-3 PG 23 WC Chemistry, Physical; Materials Science, Multidisciplinary; Mineralogy SC Chemistry; Materials Science; Mineralogy GA 334CU UT WOS:000088168500001 ER PT J AU Celliers, PM Conia, J AF Celliers, PM Conia, J TI Measurement of localized heating in the focus of an optical trap SO APPLIED OPTICS LA English DT Article ID WAVELENGTH; TWEEZERS; TEMPERATURE; DEPENDENCE; PARTICLES; CELLS; WATER AB Localized heating in the focus of an optical trap operating in water can result in a temperature rise of several kelvins. We present spatially resolved measurements of the refractive-index distribution induced by the localized heating produced in an optical trap and infer the temperature distribution. We have determined a peak temperature rise in water of 4 K in the focus of a 985-nm-wavelength 55-mW laser beam. The localized heating is directly proportional to power and the absorption coefficient. The temperature distribution is in excellent agreement with a model based on the heat equation. (C) 2000 Optical Society of America OCIS codes: 170.4520, 120.3180. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Cell Robot Inc, Albuquerque, NM 87107 USA. RP Celliers, PM (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. EM celliers1@llnl.gov NR 20 TC 25 Z9 25 U1 0 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUL 1 PY 2000 VL 39 IS 19 BP 3396 EP 3407 DI 10.1364/AO.39.003396 PG 12 WC Optics SC Optics GA 331YE UT WOS:000088045600028 PM 18349909 ER PT J AU Schoenlein, RW Chattopadhyay, S Chong, HHW Glover, TE Heimann, PA Leemans, WP Shank, CV Zholents, A Zolotorev, M AF Schoenlein, RW Chattopadhyay, S Chong, HHW Glover, TE Heimann, PA Leemans, WP Shank, CV Zholents, A Zolotorev, M TI Generation of femtosecond X-ray pulses via laser-electron beam interaction SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID 90-DEGREES THOMSON SCATTERING; DIFFRACTION; DYNAMICS; PLASMAS; DRIVEN AB The generation of femtosecond X-ray pulses will have important scientific applications by enabling the direct measurement of atomic motion and structural dynamics in condensed matter on the fundamental time scale of a vibrational period. Interaction of femtosecond laser pulses with relativistic electron beams is an effective approach to generating femtosecond pulses of X-rays. In this paper we present recent results from proof-of-principle experiments in which 300 fs pulses are generated from a synchrotron storage ring by using an ultrashort optical pulse to create femtosecond time structure on the stored electron bunch. A previously demonstrated approach for generating femtosecond X-rays via Thomson scattering between terawatt laser pulses and relativistic electrons is reviewed and compared with storage-ring based schemes. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Accelerator & Fus Res, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Berkeley, Appl Sci & Technol Grad Grp, Berkeley, CA 94720 USA. RP Schoenlein, RW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Schoenlein, Robert/D-1301-2014 OI Schoenlein, Robert/0000-0002-6066-7566 NR 30 TC 60 Z9 61 U1 1 U2 5 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD JUL PY 2000 VL 71 IS 1 BP 1 EP 10 PG 10 WC Optics; Physics, Applied SC Optics; Physics GA 379LC UT WOS:000165642700001 ER PT J AU Nooren, PA Versluis, M van der Meer, TH Barlow, RS Frank, JH AF Nooren, PA Versluis, M van der Meer, TH Barlow, RS Frank, JH TI Raman-Rayleigh-LIF measurements of temperature and species concentrations in the Delft piloted turbulent jet diffusion flame SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID NONPREMIXED FLAMES; METHANE; OH; NO AB We report a series of Raman-Rayleigh-LIF measurements in two turbulent natural-gas jet diffusion flames produced by the Delft piloted jet diffusion flame burner. The main objective of the Raman-Rayleigh-LIF measurements was to obtain detailed information on the major species concentrations in the flames. The measurements provide simultaneous data on temperature, the concentrations of the major species and the radicals OH and NO and mixture fraction. The application of the Raman technique in the undiluted natural-gas flames proves to be very challenging because of the high fluorescence interference levels. The interference contributions to the recorded Raman signals are identified and subtracted using empirical correlations between the:Raman signals and the signals on fluorescence interference monitor channels. The calibration and data reduction of the Raman-Rayleigh and LIF signals are discussed in detail. The resulting dataset compares excellently with data from previous experiments. Because the Raman-Rayleigh-LIF data provide quantitative concentrations and accordingly quantitative mixture fractions, they form a valuable and useful extension of the existing database for the Delft piloted jet diffusion flame burner. C1 Delft Univ Technol, Dept Appl Phys, Fac Sci Appl, NL-2600 GA Delft, Netherlands. Sandia Natl Labs, Combust Res Facil, Reacting Flow Res Dept, Livermore, CA 94550 USA. RP Versluis, M (reprint author), Univ Twente, POB 217, NL-7500 AE Enschede, Netherlands. RI Versluis, Michel/F-3541-2011 OI Versluis, Michel/0000-0002-2296-1860 NR 29 TC 57 Z9 57 U1 1 U2 12 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD JUL PY 2000 VL 71 IS 1 BP 95 EP 111 DI 10.1007/s003400000278 PG 17 WC Optics; Physics, Applied SC Optics; Physics GA 379LC UT WOS:000165642700013 ER PT J AU Tagami, K Uchida, S Hamilton, T Robison, W AF Tagami, K Uchida, S Hamilton, T Robison, W TI Measurement of technetium-99 in Marshall Islands soil samples by ICP-MS SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT ICRM Low-Level Radioactivity Measurement Techniques Conference CY OCT, 1999 CL MOL, BELGIUM SP Int Comm Radionuclide Metrol DE technetium-99; Marshall islands; ICP-MS; soil samples ID PLASMA-MASS-SPECTROMETRY; ENVIRONMENTAL-SAMPLES; TC-99; SEPARATION AB Extraction techniques for recovery of technetium-99 (Tc-99) for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (M1) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc From raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for 99Tc, Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the Te-99 content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The Tc-99 activity concentration in the soil samples ranged between 0.1 and 1.1 mBq g(-1) dry weight (dw). The limit of detection for Tc-99 by ICP-MS was 0.17 mBq per sample or 0.014 mBq g(-1) dw under standard operating conditions. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Radiol Sci Hosp, Environm & Toxicol Sci Res Grp, Inage Ku, Chiba 2638555, Japan. Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div, Livermore, CA 94550 USA. RP Tagami, K (reprint author), Natl Inst Radiol Sci Hosp, Environm & Toxicol Sci Res Grp, Inage Ku, Anagawa 4-9-1, Chiba 2638555, Japan. NR 14 TC 19 Z9 20 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD JUL-AUG PY 2000 VL 53 IS 1-2 BP 75 EP 79 DI 10.1016/S0969-8043(00)00115-9 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 322NC UT WOS:000087514800013 ER PT J AU Kim, SH Somorjai, GA AF Kim, SH Somorjai, GA TI TPD characterization of surface adsorption sites of model Ziegler-Natta polymerization catalysts SO APPLIED SURFACE SCIENCE LA English DT Article DE Ziegler-Natta catalyst; adsorption site; temperature-programmed desorption; chemical vapor deposition; TiCl4; MgCl2 ID TITANIUM TETRACHLORIDE; THIN-FILMS; TICL4; SPECTROSCOPY; COMPLEXES; MONOLAYER; DISORDER; SCIENCE; MGCL2 AB The surface adsorption sites of titanium chloride films that can be used as model Ziegler-Natta polymerization catalysts have been investigated with temperature-programmed desorption (TPD) of various probe molecules. The adsorption sites can be differentiated depending on the heat of desorption of the molecule. Two titanium chloride films were produced by electron-induced chemical vapor deposition of TiCl4 and co-deposition of Mg and TiCl4 on gold substrates. The surfaces of both films were chlorine-terminated. 1,3,5-Trimethylbenzene (mesitylene) was found to be an effective and non-destructive molecule for TPD characterization of adsorption sites on the model catalysts. The film produced by the electron-induced chemical vapor deposition had a distribution of adsorption sites that were not thermodynamically stable and subject to high-temperature annealing, while the film prepared by the co-deposition had a stable surface structure that was composed of domains of the MgCl2(001) basal plane structure. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 20 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD JUL PY 2000 VL 161 IS 3-4 BP 333 EP 339 DI 10.1016/S0169-4332(00)00131-8 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 343KL UT WOS:000088701500005 ER PT J AU Holden, BP Adami, C Nichol, RC Castander, FJ Lubin, LM Romer, AK Mazure, A Postman, M Ulmer, MP AF Holden, BP Adami, C Nichol, RC Castander, FJ Lubin, LM Romer, AK Mazure, A Postman, M Ulmer, MP TI The Canada-France-Hawaii telescope optical PDCS survey. II. Evolution in the space density of clusters of galaxies SO ASTRONOMICAL JOURNAL LA English DT Article DE catalogs; cosmology : observations; galaxies : clusters : general ID REDSHIFT SURVEY CATALOGS; MEDIUM-SENSITIVITY SURVEY; X-RAY DATA; LUMINOSITY FUNCTION; ASTRONOMICAL DATA; DISTANT CLUSTERS; ABELL CLUSTERS; RICH CLUSTERS; OMEGA; VELOCITIES AB We present the first dynamical study of the optically selected Palomar Distant Cluster Survey (PDCS). We have measured redshifts for 17 clusters of galaxies in the PDCS and velocity dispersions for a subset of ii. Using our new cluster redshifts, we redetermine the X-ray luminosities and upper limits. We show that 11 of 12 PDCS clusters we observed are real overdensities of galaxies. Most clusters have velocity dispersions appropriate for clusters of galaxies. However, we find a fraction (about one-third) of objects in the PDCS that have velocity dispersions in the range of groups of galaxies (200 +/- 100 km s(-1)) but have richnesses appropriate for clusters of galaxies. Within our survey volume of 31.7(-0.8)(+0.5) x 10(4) h(-3) Mpc(3) (q(0) = 0.1) for richness class 2 and greater clusters, we measure the richness function, X-ray luminosity function (using both the detections and upper limits), and the mass function derived from our velocity dispersions. We confirm that the space density, as a function of richness, of clusters of galaxies in the PDCS is similar to 5 times that of the Abell catalog. Excluding the above fraction of one-third of objects with low velocity dispersions, we measure a space density similar to 3 times that of the Abell catalog for equivalent mass clusters of galaxies, raising the possibility that the Abell catalog is incomplete. However, our space density estimates are in agreement with other low-redshift, optically selected cluster surveys such as the EDCC, APM, and EDCC2. Our X-ray luminosity function agrees with other measurements based on both X-ray and optically selected samples, so we find that the PDCS does not miss clusters of galaxies that would be found in an X-ray selected survey. Our resulting mass function, centered on 10(14) M(.) h(-1), agrees with the expectations from such surveys as the Canadian Network for Observational Cosmology cluster survey, though errors on our mass measurements are too large to constrain cosmological parameters. We do show that future machine-based, optically selected surveys can be used to constrain cosmological parameters. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. CNRS, Astron Spatiale Lab, F-13012 Marseille, France. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. CALTECH, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RP Holden, BP (reprint author), Univ Calif Davis, IGPP, LLNL, L-413,PO 808, Livermore, CA 94551 USA. EM holden@oddjob.uchicago.edu; christophe.adami@astrsp-mrs.fr; nichol@andrew.cmu.edu; fjc@ast.obs-mip.fr; lml@astro.caltech.edu; romer@andrew.cmu.edu; alain.mazure@astrsp-mrs.fr; postman@stsci.edu; m-ulmer2@nwu.edu NR 68 TC 10 Z9 10 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 2000 VL 120 IS 1 BP 23 EP 40 DI 10.1086/301446 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341HX UT WOS:000088585900002 ER PT J AU Lacy, M Bunker, AJ Ridgway, SE AF Lacy, M Bunker, AJ Ridgway, SE TI The evolution of the stellar hosts of radio galaxies SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : evolution; galaxies : formation ID NORTH-ECLIPTIC-CAP; 7C REDSHIFT SURVEY; LUMINOSITY FUNCTION; COMPLETE SAMPLE; LOUD QUASARS; IDENTIFICATIONS; Z-SIMILAR-TO-1; SPECTROSCOPY; HST AB We present new near-infrared images of z > 0.8 radio galaxies from the flux-limited 7C-III sample of radio sources for which we have recently obtained almost complete spectroscopic redshifts. The 7C objects have radio luminosities approximate to 20 times fainter than 3C radio galaxies at a given redshift. The absolute magnitudes of the underlying host galaxies and their scale sizes are only weakly dependent on radio luminosity. Radio galaxy hosts at z similar to 2 are significantly brighter than the hosts of radio-quiet quasars at similar redshifts and the recent model AGN hosts of Kauffmann & Haehnelt. There is no evidence for strong evolution in scale size, which shows a large scatter at all redshifts. The hosts brighten significantly with redshift, consistent with the passive evolution of a stellar population that formed at z greater than or similar to 3. This scenario is consistent with studies of host galaxy morphology and submillimeter continuum emission, both of which show strong evolution at z greater than or similar to 2.5. The lack of a strong "redshift cutoff" in the radio luminosity function to z > 4 suggests that the formation epoch of the radio galaxy host population lasts greater than or similar to 1 Gyr, from z greater than or similar to 5 to z similar to 3. We suggest these facts are best explained by models in which the most massive galaxies and their associated AGN form early because of high baryon densities in the centers of their dark matter haloes. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Johns Hopkins Univ, Bloomberg Ctr Phys & Astron, Baltimore, MD 21218 USA. RP Lacy, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, L-413, Livermore, CA 94550 USA. NR 53 TC 34 Z9 34 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 JUL PY 2000 VL 120 IS 1 BP 68 EP 79 DI 10.1086/301424 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341HX UT WOS:000088585900005 ER PT J AU Winters, JM Keady, JJ Gauger, A Sada, PV AF Winters, JM Keady, JJ Gauger, A Sada, PV TI Circumstellar dust shells around long-period variables VIII. CO infrared line profiles from dynamical models for C-stars SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE hydrodynamics; line : profiles; stars : circumstellar matter; stars : individual : IRC+10216; stars : AGB and post-AGB; stars : winds, outflows ID GIANT BRANCH STARS; MASS-LOSS RATES; KAPPA-MECHANISM; MIRA VARIABLES; CARBON STARS; RICH STARS; IRC+10216; ENVELOPE; IRC; ATMOSPHERES AB We present simplified non-LTE radiative transfer calculations for CO (v 0-1) fundamental and (v 0-2) overtone lines, using the structure of dynamical models for dust shells around carbon-rich long-period variables, which result from a consistent treatment of hydro- and thermodynamics, radiative transfer, chemistry and carbon grain formation. Owing to the saturation of the fundamental band absorption cores the most useful information is provided by the P-Cygni emission component, which can be used to constrain the dust optical depth in the 5 mu m region. The first overtone lines clearly reflect the shocked, layered structure of the inner shell region by showing a multi-component structure of the profiles. At least the lines of higher rotational excitation (J(l) > 10) are not saturated even for mass loss rates of the order of 10(-5) M.yr(-1) and thus can be used to constrain the mass loss rate. Furthermore, the dynamics of the dust formation process is reflected in the temporal evolution of the synthetic CO first overtone line profiles resulting from the models. The formation of a new dust layer in the inner shell region leads to a secondary (low velocity) absorption component which evolves on the time scale of a dust formation event, usually longer than the pulsation period of the star. The synthetic overtone line profiles calculated on the basis of one dust shell model resemble the time variations of corresponding lines in the observed high resolution CO line spectra of the carbon-Mira IRC +102161 which thereby are interpreted as result of a dust formation event taking place on a time scale of approximate to 10 yr corresponding to 6 pulsation periods of the star. However, the calculated fundamental line absorption cores are broader than observed and the first overtone line strengths are too high, indicating that the density and thus probably the mass loss rate of the model is too high by a factor of about 3 and should be closer to the value of 1 10(-5) M.yr(-1) given for IRC +10216 in the literature. C1 Max Planck Inst Radioastron, D-53121 Bonn, Germany. Tech Univ Berlin, Inst Astron & Astrophys, D-10623 Berlin, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Fachhsch Fulda, D-36039 Fulda, Germany. Univ Monterrey, Dept Fis & Matemat, Garza Garcia 66238, NL, Mexico. RP Winters, JM (reprint author), Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany. EM jwinters@mpifr-bonn.mpg.de NR 55 TC 36 Z9 36 U1 0 U2 0 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 JUL PY 2000 VL 359 IS 2 BP 651 EP 662 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341JJ UT WOS:000088587000030 ER PT J AU Ruffini, R Salmonson, JD Wilson, JR Xue, SS AF Ruffini, R Salmonson, JD Wilson, JR Xue, SS TI On the pair-electromagnetic pulse from an electromagnetic black hole surrounded by a baryonic remnant SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE black hole physics; gamma rays : theory; gamma rays : bursts; gamma rays : observations AB The interaction of an expanding Pair-Electromagnetic pulse (PEM pulse) with a shell of baryonic matter surrounding a Black Hole with electromagnetic structure (EMBH) is analyzed for selected values of the baryonic mass at selected distances well outside the dyadosphere of an EMBH. The dyadosphere, the region in which a super critical field exists for the creation of e(+)e(-) pairs, is here considered in the special case of a Reissner-Nordstrom geometry. The interaction of the PEM pulse with the baryonic matter is described using a simplified model of a slab of constant thickness in the laboratory frame (constant-thickness approximation) as well as pet-forming the integration of the general relativistic hydrodynamical equations. Te validation of the constant-thickness approximation, already presented in a previous paper Ruffini et al. (1999) for a PEM pulse in vacuum, is here generalized to the presence of baryonic matter. It is found that for a baryonic shell of mass-energy less than 1% of the total energy of the dyadosphere, the constant-thickness approximation is in excellent agreement with full general relativistic computations. The approximation breaks down for larger values of the baryonic shell mass, however such cases are of less interest for observed Gamma Ray Bursts (GRBs). On the basis of numerical computations of the slab model for PEM pulses, we describe (i) the properties of relativistic evolution of a PEM pulse colliding with a baryonic shell; (ii) the details of the expected emission energy and observed temperature of the associated GRBs for a given value of the EMBH mass; 10(3)M(circle dot), and for baryonic mass-energies in the range 10(-8) to 10(-2) the total energy of the dyadosphere. C1 Univ Rome La Sapienza, ICRA, Int Ctr Relativist Astrophys, 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, Int Ctr Relativist Astrophys, Piazzale Aldo Moro 5, I-00185 Rome, Italy. EM ruffini@icra.it NR 13 TC 108 Z9 108 U1 0 U2 0 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 JUL PY 2000 VL 359 IS 3 BP 855 EP 864 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341JZ UT WOS:000088588400005 ER PT J AU Hui, L Kofman, L Shandarin, SF AF Hui, L Kofman, L Shandarin, SF TI Multiple streaming and the probability distribution of density in redshift space SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : distances and redshifts; gravitation; large-scale structure of universe ID LARGE-SCALE STRUCTURE; GRAVITATIONAL-INSTABILITY; POWER SPECTRUM; COSMOLOGICAL CONSTANT; GALAXY REDSHIFTS; COLD MATTER; UNIVERSE; APPROXIMATIONS; DISTORTIONS; OMEGA AB We examine several aspects of redshift distortions by expressing the redshift-space density in terms of the eigenvalues and orientation of the local Lagrangian deformation tensor. We explore the importance of multiple streaming using the Zeldovich approximation (ZA), and compute the average number of streams in both real and redshift space. We find that multiple streaming can be significant in redshift space but negligible in real space, even at moderate values of the linear fluctuation amplitude (sigma(l) less than or similar to 1). Moreover, unlike their real-space counterparts, redshift-space multiple streams can how past each other with minimal interactions. Such nonlinear redshift-space effects, which are physically distinct from the fingers-of-God due to small-scale virialized motions, might in part explain the well-known departure of redshift distortions from the classic linear prediction by Kaiser, even at relatively large scales where the corresponding density held in real space is well described by linear perturbation theory. We also compute, using the ZA, the probability distribution function (PDF) of the density, as well as S-3, in real and redshift space, and compare it with the PDF measured from N-body simulations. The role of caustics in defining the character of the high-density tail is examined. We find that (non-Lagrangian) smoothing, due to both finite resolution or discreteness and small-scale velocity dispersions, is very effective in erasing caustic structures, unless the initial power spectrum is sufficiently truncated. C1 NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. CITA, Toronto, ON M5S 3H8, Canada. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. RP Hui, L (reprint author), NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 43 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 JUL 1 PY 2000 VL 537 IS 1 BP 12 EP 20 DI 10.1086/308991 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000002 ER PT J AU Walker, KC Schaefer, BE Fenimore, EE AF Walker, KC Schaefer, BE Fenimore, EE TI Gamma-ray bursts have millisecond variability SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; methods : statistical ID 28 FEBRUARY 1997; TRANSIENT; AFTERGLOW AB We have performed searches for isolated flares and for steady flickering in the initial similar to 1 s of gamma-ray burst light curves on the microsecond to millisecond timescales. Two bursts among our sample of 20 revealed four isolated flares with timescales from 256 to 2048 mu s. A wavelet analysis for our sample showed low-level flickering for all bursts on timescales from 256 mu s to 33 ms, with the majority of bursts containing rise times faster than 4 ms and 30% having rise times faster than 1 ms. These results show that millisecond variability is common in classical bursts and not some exceptional activity by a possibly separate class of bursts. These fast rise times can be used to place the following severe limits on burst models. (1) The characteristic thickness of the energy generation region must be less than 1200 km along the line of sight. (2) The angular size of the gamma-ray emission region as subtended from the central source must be less than 42 ". (3) The expanding ejecta must have a range of Lorentz factors along a radius line with a dispersion of less than roughly 2%. (4) Within the external shock scenario, the characteristic dimension of the impacted cloud must be smaller than 16 AU on average. (5) Within the collimated jet scenario, the collimation angle must be smaller than 42 ". C1 Yale Univ, New Haven, CT 06520 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Walker, KC (reprint author), Yale Univ, POB 208121, New Haven, CT 06520 USA. NR 25 TC 31 Z9 32 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 JUL 1 PY 2000 VL 537 IS 1 BP 264 EP 269 DI 10.1086/308995 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000024 ER PT J AU Lisewski, AM Hillebrandt, W Woosley, SE Niemeyer, JC Kerstein, AR AF Lisewski, AM Hillebrandt, W Woosley, SE Niemeyer, JC Kerstein, AR TI Distributed burning in Type Ia supernovae: A statistical approach SO ASTROPHYSICAL JOURNAL LA English DT Article DE methods : statistical; nuclear reactions, nucleosynthesis, abundances supernovae : general; turbulence ID DELAYED DETONATION MODELS; PREMIXED FLAMES; NUCLEAR FLAMES; LIGHT CURVES; WHITE-DWARFS; PROPAGATION; EXPLOSION AB We present a statistical model which shows the influence of turbulence on a thermonuclear flame propagating in C+O white dwarf matter. Based on a Monte Carlo description of turbulence, it provides a method for investigating the physics in the so-called distributed burning regime. Using this method, we perform numerical simulations of turbulent flames and show that in this particular regime the flamelet model for the turbulent flame velocity loses its validity. In fact, at high turbulent intensities, burning in the distributed regime can lead to a deceleration of the turbulent flame and thus induce a competing process to turbulent effects that cause a higher flame speed. It is also shown that in dense C+O matter turbulent heat transport is described adequately by the Peclet number rather than by the Reynolds number, which means that flame propagation is decoupled from small-scale turbulence. Finally, at the onset of our results we argue that the available turbulent energy in an exploding C+O white dwarf is probably too low to make a deflagration-to-detonation transition possible. C1 Max Planck Inst Astrophys, D-85740 Garching, Germany. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Max Planck Inst Astrophys, Karl Schwarzschild Str 1, D-85740 Garching, Germany. OI Niemeyer, Jens/0000-0002-3063-4325 NR 29 TC 21 Z9 21 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP 405 EP 413 DI 10.1086/309015 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000038 ER PT J AU Griffiths, NW Fisher, GH Woods, DT Acton, LW Siegmund, OHW AF Griffiths, NW Fisher, GH Woods, DT Acton, LW Siegmund, OHW TI Simultaneous SOHO and Yohkoh observations of a small solar active region SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : activity; Sun : transition region; Sun : UV radiation ID CORONA TRANSITION REGION; UNRESOLVED FINE-STRUCTURES; EXTREME-ULTRAVIOLET; QUIET-SUN; THERMAL CONDUCTION; TEMPERATURE REGION; MAGNETIC-FIELD; ENERGY-BALANCE; CHROMOSPHERE; SPECTROGRAPH AB We present new results from observations of a small active region taken with the SUMER spectrograph and Extreme Ultraviolet Imaging Telescope (EIT) on SOHO and with the Soft X-Ray Telescope (SXT) on Yohkoh. The SUMER study features line and continuum emission covering a wide range of temperatures and includes the density-sensitive O IV] lambda 1400 multiplet. A more extensive analysis of quiet Sun data presented in a previous paper is also included. The presence of a power-law relationship between emission-line power and electron density is confirmed, although the exponents in the active region are slightly higher than those found in the quiet Sun. These power-law relationships suggest that the volume filling factor decreases with increasing density and indicate possible differences between emitting material in active regions and the quiet Sun. We study active-region emission measures from both the SUMER and SXT data sets. For the active region as a whole, SXT temperatures and emission measures appear to fit smoothly onto the emission-measure distribution determined from cooler transition region and coronal lines in the SUMER spectra. We find no significant variation in the shape of the lower transition region emission-measure distribution for different subregions of the data set. This reinforces the conclusion from the original quiet Sun paper that ensembles of "cool loops" are unlikely to be the source of this emission unless the structures are considerably smaller than the 1 " spatial resolution of SUMER. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RP Griffiths, NW (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Fisher, George/G-1380-2015 OI Fisher, George/0000-0002-6912-5704 NR 48 TC 7 Z9 7 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 JUL 1 PY 2000 VL 537 IS 1 BP 481 EP 494 DI 10.1086/309005 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000046 ER PT J AU Timmes, FX Hoffman, RD Woosley, SE AF Timmes, FX Hoffman, RD Woosley, SE TI An inexpensive nuclear energy generation network for stellar hydrodynamics SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE hydrodynamics; methods : numerical; nuclear reactions, nucleosynthesis, abundances; stars : general ID THERMONUCLEAR REACTION-RATES AB We compare the nuclear energy generation rate and abundance levels given by an alpha -chain nuclear reaction network that contains only seven isotopes with a standard 13 isotope alpha -chain reaction network. The energy generation rate of these two small networks are also compared to the energy generation rate given by a 489 isotope reaction network with weak reactions turned on and off. The comparison between the seven isotope and ct-chain reaction networks indicate the extent to which one can be replaced by the other, and the comparison with the 489 isotope reaction network roughly indicates under what physical conditions it is safe to use the seven isotope and ct-chain reaction networks. The seven isotope reaction network reproduces the nuclear energy generation rate of the standard alpha -chain reaction network to within 30%, but often much better, during hydrostatic and explosive helium, carbon, and oxygen burning. It will also provide energy generation rates within 30% of an alpha -chain reaction network for silicon burning at densities less than 10(7) g cm(-3). Provided there remains an equal number of protons and neutrons (Y-e = 0.5) over the course of the evolution, and that flows through alpha -particle channels dominate, then both of the small reaction networks return energy generation rates that are compatible with the energy generation rate returned by the 489 reaction network. If Y-e is significantly different from 0.5, or if there are substantial hows through neutron and protons channels, then it is not generally safe to employ any alpha -chain based reaction network. The relative accuracy of the seven isotope reaction network, combined with its reduction in the computational cost, suggest that it is a suitable replacement for alpha -chain reaction networks for parameter space surveys of a wide class of multidimensional stellar models. C1 Univ Chicago, Ctr Astrophys Thermonuclear Flashes, Chicago, IL 60637 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Timmes, FX (reprint author), Univ Chicago, Ctr Astrophys Thermonuclear Flashes, 933 E 56th St, Chicago, IL 60637 USA. NR 18 TC 53 Z9 53 U1 0 U2 0 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 JUL PY 2000 VL 129 IS 1 BP 377 EP 398 DI 10.1086/313407 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MC UT WOS:000089954200017 ER PT J AU Chin, G Carroll, JM AF Chin, G Carroll, JM TI Articulating collaboration in a learning community SO BEHAVIOUR & INFORMATION TECHNOLOGY LA English DT Article AB A common computer-based collaborative learning approach is to simply introduce contemporary computer-mediated communication technology into the classroom to support prescribed learning activities. This approach assumes that all students collaborate in similar ways and that present-day technology is sufficient to accommodate all collaboration forms. This view is superficial and limiting. Students collaborate in different ways at different levels on different learning activities. A more detailed articulation of collaboration in learning is crucial to understanding and extending the pedagogical capabilities and usefulness of collaborative technologies. A model is presented for a more finely articulated form of analysis that enumerates types of collaborative learning activities and evaluates how these activities may be supported through different design opt ions. The analysis is based on actual classroom scenarios and the collaboration requirements that emerge from them. The authors have successfully applied this analysis model in the design of a computer-based collaborative learning environment for science education. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Virginia Polytech Inst & State Univ, Dept Comp Sci, Blacksburg, VA 24061 USA. RP Chin, G (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Carroll, John/A-8718-2009 OI Carroll, John/0000-0001-5189-337X NR 17 TC 6 Z9 6 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0144-929X J9 BEHAV INFORM TECHNOL JI Behav. Inf. Technol. PD JUL-AUG PY 2000 VL 19 IS 4 BP 233 EP 245 DI 10.1080/01449290050086354 PG 13 WC Computer Science, Cybernetics; Ergonomics SC Computer Science; Engineering GA 344UR UT WOS:000088778000001 ER PT J AU Patterton, HG Graves, S AF Patterton, HG Graves, S TI DNAssist: the integrated editing and analysis of molecular biology sequences in Windows SO BIOINFORMATICS LA English DT Article AB Motivation: The programs currently available for the analysis of nucleic acid and protein sequences suffer from a variety of problems: Web-based programs often require inconvenient reformatting of sequences when proceeding from one analysis to the next, and commercial-console-based programs are cost prohibitive. Here, we report the development of DNAssist, an inexpensive multiple-document, interface program for the fully integrated editing and analysis of nucleic acid and protein sequences in the familiar environment of Microsoft Windows. C1 Univ Cape Town, Dept Biochem, ZA-7700 Rondebosch, South Africa. Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Graves, S (reprint author), POB 1024, Los Alamos, NM 87544 USA. OI Patterton, Hugh-George/0000-0003-2550-0493 NR 3 TC 33 Z9 36 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD JUL PY 2000 VL 16 IS 7 BP 652 EP 653 DI 10.1093/bioinformatics/16.7.652 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 368DF UT WOS:000090101900010 PM 11038336 ER PT J AU Miyabe, K Guiochon, G AF Miyabe, K Guiochon, G TI A study of mass transfer kinetics in an enantiomeric separation system using a polymeric imprinted stationary phase SO BIOTECHNOLOGY PROGRESS LA English DT Article ID TRANSFER RATE COEFFICIENT; BOVINE SERUM-ALBUMIN; CONCENTRATION-DEPENDENCE; LATERAL DIFFUSION; SURFACE-DIFFUSION; CELLULOSE TRIACETATE; LIGHT-SCATTERING; PORE DIFFUSION; TROGERS BASE; CHROMATOGRAPHY AB Chromatographic data pertaining to the enantioseparation of L- and D-phenylalanine anilide (PA) on a polymeric stationary phase imprinted with L-PA were studied from the viewpoints of phase equilibrium, mass transfer kinetics, and the thermodynamic properties of this enantiomeric separation system. The concentration dependence of the lumped mass transfer rate coefficient (k(m,L)) previously published was analyzed to obtain new information concerning the mass transfer characteristics in this chiral separation system. It was shown that intraparticle diffusion contributed much more to k(m,L) than adsorption/desorption. The positive concentration dependence of k(m,L) seemed to be interpreted by considering that of the surface diffusion coefficient, itself explained by the heterogeneous surface model. The characteristic features of the phase equilibrium, the mass transfer kinetics, and the thermodynamics of the enantiomeric separation system probably result from the adsorption energy distribution on the surface of the imprinted phase having an exponential decay. 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 39 TC 30 Z9 31 U1 0 U2 1 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 JUL-AUG PY 2000 VL 16 IS 4 BP 617 EP 629 DI 10.1021/bp000046w PG 13 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 343PF UT WOS:000088710200015 PM 10933837 ER PT J AU Brady, MJ Risch, TS Dobson, FS AF Brady, MJ Risch, TS Dobson, FS TI Availability of nest sites does not limit population size of southern flying squirrels SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID COLUMBIAN GROUND-SQUIRRELS; GLAUCOMYS-VOLANS; HOME-RANGE AB Among factors that may limit population size, nest site is generally considered important for cavity-nesting species. We tested the hypothesis that nest-site availability limits population size in the southern flying squirrel (Glaucomys volans) by examining the effect of experimentally increasing the number of nest sites. We compared population sizes before and after adding 100 nest boxes (high-quality nests, increasing overall nest density by at least about 65%) on each of three experimental sites on the Savannah River Site in South Carolina. We also compared the experimental populations with three reference (unmanipulated) sites in a paired-block experimental design. All six populations were similarly monitored with livetrapping grids, and flying squirrels readily nested in the supplemental boxes. We predicted that population size would increase where nest sites were added. No increases in population size were observed after nest boxes were added to the three experimental sites, however, nor were populations higher on the experimental sites than on the reference sites. The lack of increase in population size after nest boxes were added demonstrates that the availability of nest sites was not limiting the size of these populations. C1 Auburn Univ, Dept Biol Sci, Auburn, AL 36849 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Brady, MJ (reprint author), Univ Kansas, Museum Nat Hist, Lawrence, KS 66045 USA. NR 23 TC 19 Z9 20 U1 2 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD JUL PY 2000 VL 78 IS 7 BP 1144 EP 1149 DI 10.1139/cjz-78-7-1144 PG 6 WC Zoology SC Zoology GA 335XY UT WOS:000088272900005 ER PT J AU Izumi, T Hazra, TK Boldogh, I Tomkinson, AE Park, MS Ikeda, S Mitra, S AF Izumi, T Hazra, TK Boldogh, I Tomkinson, AE Park, MS Ikeda, S Mitra, S TI Requirement for human AP endonuclease 1 for repair of 3 '-blocking damage at DNA single-strand breaks induced by reactive oxygen species SO CARCINOGENESIS LA English DT Article ID BASE-EXCISION-REPAIR; HUMAN APURINIC/APYRIMIDINIC ENDONUCLEASE; POLYMERASE-BETA; PURIFIED PROTEINS; MAMMALIAN-CELLS; EXONUCLEASE-III; BOVINE TESTIS; LIGASE-I; IDENTIFICATION; RECONSTITUTION AB The major mammalian apurinic/apyrimidinic (AP) endonuclease (APE1) plays a central role in the DNA base excision repair pathway (BER) in two distinct ways, As an AP endonuclease, it initiates repair of Ar sites in DNA produced either spontaneously or after removal of uracil and alkylated bases in DNA by monofunctional DNA glycosylases, Alternatively, by acting as a 3'-phosphoesterase, it initiates repair of DNA strand breaks with 3'-blocking damage, which are produced either directly by reactive oxygen species (ROS) or indirectly through the AP lyase reaction of damage-specific DNA glycosylases. The endonuclease activity of APE1, however, is much more efficient than its DNA 3'-phosphoesterase activity. Using whole extracts from human HeLa and lymphoblastoid TK6 cells, we have investigated whether these two activities differentially affect BER efficiency. The repair of ROS-induced DNA strand breaks was significantly stimulated by supplementing the reaction with purified APE1, This enhancement was linearly dependent on the amount of APE1 added, while addition of other BER enzymes, such as DNA ligase I and FEN1, had no effect. Moreover, depletion of endogenous APE1 from the extract significantly reduced the repair activity, suggesting that APE1 is essential for repairing such DNA damage and is limiting in extracts of human cells. In contrast, when uracil-containing DNA was used as the substrate, the efficiency of repair was not affected by exogenous APE1, presumably because the AP endonuclease activity was not limiting. These results indicate that the cellular level of APE1 may differentially affect repair efficiency for DNA strand breaks but not for uracil and AP sites in DNA. C1 Univ Texas, Med Branch, Sealy Ctr Mol Sci, Galveston, TX 77555 USA. Univ Texas, Med Branch, Dept Human Biol Chem & Genet, Galveston, TX 77555 USA. Univ Texas, Med Branch, Dept Microbiol, Galveston, TX 77555 USA. Inst Biotechnol, Dept Mol Med, San Antonio, TX 78245 USA. Univ Calif Los Alamos Natl Lab, Dept Biol Sci, Los Alamos, NM 87545 USA. Okayama Univ Sci, Fac Sci, Dept Biochem, Okayama 700, Japan. RP Izumi, T (reprint author), Univ Texas, Med Branch, Sealy Ctr Mol Sci, Galveston, TX 77555 USA. FU NCI NIH HHS [CA53791]; NIA NIH HHS [AG10514]; NIEHS NIH HHS [ES08457] NR 47 TC 144 Z9 147 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD JUL PY 2000 VL 21 IS 7 BP 1329 EP 1334 DI 10.1093/carcin/21.7.1329 PG 6 WC Oncology SC Oncology GA 336QD UT WOS:000088313700008 PM 10874010 ER PT J AU Lane, PA Mellor, H Martin, SJ Hagler, TW Bleyer, A Bradley, DDC AF Lane, PA Mellor, H Martin, SJ Hagler, TW Bleyer, A Bradley, DDC TI Electroabsorption spectroscopy of distyrylbenzene derivatives SO CHEMICAL PHYSICS LA English DT Article DE distyrylbenzene; electroabsorption; electronic structure; symmetry; substitution ID CONJUGATED POLYMERS; 2-PHOTON ABSORPTION; OPTICAL-ABSORPTION; MEH-PPV; FLUORESCENCE; PHENYLENE AB We have studied the linear and nonlinear optical properties of model oligomers based on trans, trans'-distyrylbenzene to investigate the effects of chemical modification on the electronic structure of stilbenoid oligomers and polymers. Replacing the central para-phenylene ring with a meta-phenylene ring reduces the conjugation of the molecule and introduces disorder into the film, which significantly reduces Davydov splitting of the main absorption band. Alkoxy substitution of any of the phenylene rings red shifts the lowest energy absorption band and enhances the oscillator strength of a high-energy sideband. Absorption by aggregates, which is obscured by effects of scattering on the absorption spectrum, is clearly revealed by electroabsorption spectroscopy. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Sheffield, Dept Phys & Astron, Sheffield S3 7RH, S Yorkshire, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lane, PA (reprint author), Hicks Bldg,Hounsfield Rd, Sheffield S3 7RH, S Yorkshire, England. RI Bradley, Donal/F-6068-2011; Martin, Simon Martin/H-1431-2011 OI Bradley, Donal/0000-0001-8713-5060; NR 25 TC 16 Z9 16 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD JUL 1 PY 2000 VL 257 IS 1 BP 41 EP 49 DI 10.1016/S0301-0104(00)00146-4 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 330PL UT WOS:000087970400004 ER PT J AU Grate, JW AF Grate, JW TI Acoustic wave microsensor arrays for vapor sensing SO CHEMICAL REVIEWS LA English DT Review ID NETWORK PATTERN-RECOGNITION; THICKNESS-SHEAR-MODE; CHEMICAL SENSOR ARRAYS; SOLVATION ENERGY RELATIONSHIPS; PIEZOELECTRIC CRYSTAL SENSORS; ASSEMBLED COMPOSITE MONOLAYER; SENSITIVE DENDRIMER SURFACES; VOLATILE ORGANIC-COMPOUNDS; PHASE PROBE MOLECULES; PLASMA-POLYMER-FILMS C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 205 TC 289 Z9 292 U1 7 U2 54 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 EI 1520-6890 J9 CHEM REV JI Chem. Rev. PD JUL PY 2000 VL 100 IS 7 BP 2627 EP 2647 DI 10.1021/cr980094j PG 21 WC Chemistry, Multidisciplinary SC Chemistry GA 337MY UT WOS:000088366500008 ER PT J AU Nolas, GS Chakoumakos, BC Mahieu, B Long, GJ Weakley, TJR AF Nolas, GS Chakoumakos, BC Mahieu, B Long, GJ Weakley, TJR TI Structural characterization and thermal conductivity of type-I tin clathrates SO CHEMISTRY OF MATERIALS LA English DT Article ID ATOMIC DISPLACEMENT PARAMETERS; THERMOELECTRIC APPLICATIONS; COMPOUND; SILICON; PHASES AB Three tin compounds, Cs8Sn44, Cs8Ga8Sn38, and Cs8Zn4Sn42, representative of the type-I clathrate hydrate crystal structure are structurally characterized by temperature-dependent neutron powder diffraction, 87 K Sn-119 Mossbauer spectroscopy, and room-temperature single-crystal X-ray diffraction. These compounds form in cubic space group Pm (3) over bar n with alkalimetal atoms residing in the polyhedral cavities formed by the tetrahedrally bonded network of Sn atoms. Of particular interest are the atomic displacement parameters (ADPs) exhibited by the alkali-metal atom inside the polyhedral "cages" formed by the framework Sn atoms. The "guest" Cs atoms inside the larger tetrakaidecahedra show a relatively large room-temperature ADP for Cs8Ga8Sn38 and Cs8Zn4Sn42; however, in the defect Cs8Sn44 compound this is not the case. This is due to two Sn vacancies in Cs8Sn44 which affect the local symmetry and Sn-Sn bonding. Temperature-dependent ADPs for the defect Cs8Sn44 compound are compared to those for Cs8Zn8Sn42. These data help elucidate the cause of the different lattice thermal conductivities of these two compounds. C1 Marlow Ind Inc, R&D Div, Dallas, TX 75238 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Catholique Louvain, Dept Chem, B-1348 Louvain, Belgium. Univ Missouri, Dept Chem, Rolla, MO 65401 USA. Univ Oregon, Dept Chem, Eugene, OR 97403 USA. RP Nolas, GS (reprint author), Marlow Ind Inc, R&D Div, 10451 Vista Pk Rd, Dallas, TX 75238 USA. EM gnolas@marlow.com RI Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 22 TC 66 Z9 67 U1 1 U2 23 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 JUL PY 2000 VL 12 IS 7 BP 1947 EP 1953 DI 10.1021/cm990686y PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 336CT UT WOS:000088284900024 ER PT J AU Reilly, PTA Gieray, RA Whitten, WB Ramsey, JM AF Reilly, PTA Gieray, RA Whitten, WB Ramsey, JM TI Direct observation of the evolution of the soot carbonization process in an acetylene diffusion flame via real-time aerosol mass spectrometry SO COMBUSTION AND FLAME LA English DT Article ID MORPHOLOGICAL CONTROL; PRECURSOR PARTICLES; SOLUTION DROPLETS; HYDROCARBONS; EVAPORATION; SIZE AB Real-time aerosol mass spectrometry was used to measure the size and composition of individual soot particles in an acetylene diffusion flame. This on-line data analysis technique permits for the first time direct observation of the evolution of the carbonization process, determination of the degree of carbonization of each measured particle, and measurement of the size distribution of both polycyclic aromatic hydrocarbon (PAH)-containing and mature soot particles. The carbonization process is characterized by rapid exchange of hydrogen between the PAH and pyrolytic addition of small hydrocarbons to form larger PAH molecules. The hydrogen exchange rare builds until carbon-carbon bond rearrangement becomes facile. The structural rearrangement/dehydrogenation process is very rapid once started. Rapid carbonization permits unambiguous size measurement of both PAH-containing and mature soot particles. Rapid hydrogen exchange yields a low activation energy path for making radicals in the particle phase and permits the PAH-containing media to act as a hydrogen sink. The presence of substantial amounts of labile hydrogen in the PAH-containing particle is demonstrated by the presence of preferentially hydrogenated PAHs. The absence of ethynylated PAHs and the presence of the hydrogenated PAI-Is are the result of flame pyrolysis of the PAH-containing particles. Optical images of flame particles collected by an independent sampling method conclusively confirm the presence of the micron sized PAH-containing particles in the flame and strongly suggest that mature soot aggregates are formed directly from the micron-sized PAH-containing particles. The optical images and the size distribution data cast doubt on the currently accepted mechanisms for mature soot aggregate formation. A new mature soot aggregate formation mechanism found in the aerosol literature is presented. This mechanism readily explains our results and many of the universal characteristics of soot. The implications of these measurements are discussed. Published by Elsevier Science Inc. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Reilly, PTA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 29 TC 40 Z9 40 U1 0 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD JUL PY 2000 VL 122 IS 1-2 BP 90 EP 104 DI 10.1016/S0010-2180(00)00105-X PG 15 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 322QM UT WOS:000087520300007 ER EF