FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Muzzy, LE Avdeev, M Lawes, G Haas, MK Zandbergen, HW Ramirez, AP Jorgensen, JD Cava, RJ AF Muzzy, LE Avdeev, M Lawes, G Haas, MK Zandbergen, HW Ramirez, AP Jorgensen, JD Cava, RJ TI Structure and superconductivity in Zr-stabilized, nonstoichiometric molybdenum diboride SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE intermetallic superconductor; isotope effect; crystal structure; specific heat; electronic structure; neutron diffraction; electron microscopy ID ELECTRONIC-STRUCTURE; MGB2 AB The structure and physical properties of the Zr-stabilized, nonstoichiometric molybdenum diboride superconductor are reported. Good quality material of the diboride structure type can only be obtained by partial substitution of Zr for Mo, and quenching of melts. The diboride phase is best made with boron in excess of the ideal 2:1 boron to metal ratio. Powder neutron diffraction measurements show that the nonstoichiometry is accommodated by atom deficiency in the metal layers. The diboride structure type exists for (Mo0.96Zr0.04)(x)B-2 for 1.0 greater than or equal to x greater than or equal to 0.85. Electron diffraction shows that the stoichiometric material, x = 1, has a significant number of stacking faults. T-c increases from 5.9 to 8.2 K with the introduction of metal vacancies. Resistivity measurements indicate that (Mo0.96Zr0.04)(0.88)B-2 is a bad metal, and specific heat measurements show its electronic density of states (DOS) is gamma = 4.4 mJ/mol K-2, and that DeltaC/gammaT(c) = 1.19. Preliminary boron isotope effect measurements indicate an exponent alpha = 0.11 +/- 0.05. Analysis of the data in terms of the electronic structure is reported, allowing an estimate of the electron-phonon coupling constant, lambda approximate to 0.1-0.3, making these weak-coupling superconductors. Preliminary characterizations of the superconductivity in the related phases NbxB2 and (Mo0.96X0.04)(0.85)B-2 for X = Ti and Hf are reported. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Princeton Mat Inst, Dept Chem, Princeton, NJ 08544 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Delft Univ Technol, Natl Ctr HREM, Mat Sci Lab, NL-2628 AL Delft, Netherlands. RP Cava, RJ (reprint author), Princeton Univ, Princeton Mat Inst, Dept Chem, Princeton, NJ 08544 USA. RI Avdeev, Maxim/A-5625-2008 OI Avdeev, Maxim/0000-0003-2366-5809 NR 22 TC 16 Z9 16 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 1 PY 2002 VL 382 IS 2-3 BP 153 EP 165 AR PII S0921-4534(02)01861-0 DI 10.1016/S0921-4534(02)01861-0 PG 13 WC Physics, Applied SC Physics GA 617HB UT WOS:000179355300001 ER PT J AU Hinks, DG Jorgensen, JD Zheng, H Short, S AF Hinks, DG Jorgensen, JD Zheng, H Short, S TI Synthesis and stoichiometry of MgB2 SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE MgB2; stoichiometry; synthesis ID PULSED-LASER DEPOSITION; T-C; STRUCTURAL TRANSITION; THIN-FILMS; SUPERCONDUCTOR; SUBSTITUTION; TEMPERATURE; PHASE; LI AB The system MgxB2 has been studied to investigate possible nonstoichiometry in MgB2. When synthesized at 850 degreesC, MgB2 is a line compound with a possible Mg vacancy content of about 1%. Small changes in lattice constants as a function of starting composition result from grain-interaction stresses, whose character is different in the Mg-rich, near-stoichiometric, and Mg-deficient regimes. A small linear decrease of the superconducting transition temperature, T-c, in the Mg-rich regime results from accidental impurity doping. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave,Bldg 223, Argonne, IL 60439 USA. EM hinks@anl.gov NR 31 TC 74 Z9 74 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 EI 1873-2143 J9 PHYSICA C JI Physica C PD NOV 1 PY 2002 VL 382 IS 2-3 BP 166 EP 176 AR PII S0921-4534(02)01842-7 DI 10.1016/S0921-4534(02)01842-7 PG 11 WC Physics, Applied SC Physics GA 617HB UT WOS:000179355300002 ER PT J AU Ribeiro, RA Bud'ko, SL Petrovic, C Canfield, PC AF Ribeiro, RA Bud'ko, SL Petrovic, C Canfield, PC TI Effects of stoichiometry, purity, etching and distilling on resistance of MgB2 pellets and wire segments SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE MgB2; stoichiometry; transport properties ID SUPERCONDUCTIVITY; TRANSPORT AB We present a study of the effects of non-stoichiometry, boron purity, wire diameter and post-synthesis treatment (etching and Mg distilling) on the temperature dependent resistance and resistivity of sintered MgB2 pellets and wire segments. Whereas the residual resistivity ratio (RRR) varies between RRR approximate to 4 to RRR greater than or equal to 20 for different boron purity, it is only moderately affected by non-stoichiometry (from 20% Mg deficiency to 20% Mg excess) and is apparently independent of wire diameter and presence of Mg metal traces on the wire surface. The obtained set of data indicates that RRR values in excess of 20 and residual resistivities as low as rho(0) approximate to 0.4 muOmega cm are intrinsic material properties of high purity MgB2. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Ribeiro, RA (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RI Petrovic, Cedomir/A-8789-2009; Ribeiro, Raquel/B-9041-2012; Canfield, Paul/H-2698-2014 OI Petrovic, Cedomir/0000-0001-6063-1881; Ribeiro, Raquel/0000-0001-6075-1701; NR 11 TC 36 Z9 37 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 1 PY 2002 VL 382 IS 2-3 BP 194 EP 202 AR PII S0921-4534(02)01840-3 DI 10.1016/S0921-4534(02)01840-3 PG 9 WC Physics, Applied SC Physics GA 617HB UT WOS:000179355300005 ER PT J AU Goyal, A Feenstra, R Paranthaman, M Thompson, JR Kang, BY Cantoni, C Lee, DF List, FA Martin, PM Lara-Curzio, E Stevens, C Kroeger, DM Kowalewski, M Specht, ED Aytug, T Sathyamurthy, S Williams, RK Ericson, RE AF Goyal, A Feenstra, R Paranthaman, M Thompson, JR Kang, BY Cantoni, C Lee, DF List, FA Martin, PM Lara-Curzio, E Stevens, C Kroeger, DM Kowalewski, M Specht, ED Aytug, T Sathyamurthy, S Williams, RK Ericson, RE TI Strengthened, biaxially textured Ni substrate with small alloying additions for coated conductor applications SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID BUFFER LAYERS; THICK-FILMS; YBCO FILMS; GROWTH; OXIDE; EVAPORATION AB Fabrication of a biaxially textured, strengthened Ni substrate with small alloying additions of W and Fe is reported. The substrates have significantly improved mechanical properties compared to 99.99% Ni and surface characteristics which are similar to that of 99.99% Ni substrates. High quality oxide buffer layers can be deposited on these substrates without the need for any additional surface modification steps. Grain boundary misorientation distributions obtained from the substrate show a predominant fraction of low-angle grain boundaries. A high critical current density, J(c) of 1.9 MA/cm(2) at 77 K, self-field is demonstrated on this substrate using a multilayer configuration of YBCO/CeO2/YSZ/Y2O3/Ni-3at.%W-1.7at.%Fe. This translates to a I-c/width of 59 A/cm at 77 K and self-field. J(c) at 0.5 T is reduced by only 21% indicating strongly-linked grain boundaries in the YBCO film on this substrate. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Goyal, A (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Cantoni, Claudia/G-3031-2013 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Cantoni, Claudia/0000-0002-9731-2021 NR 24 TC 63 Z9 66 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 1 PY 2002 VL 382 IS 2-3 BP 251 EP 262 AR PII S0921-4534(02)00626-3 DI 10.1016/S0921-4534(02)00626-3 PG 12 WC Physics, Applied SC Physics GA 617HB UT WOS:000179355300014 ER PT J AU Specht, ED List, FA Lee, DF More, KL Goyal, A Robbins, WB O'Neill, D AF Specht, ED List, FA Lee, DF More, KL Goyal, A Robbins, WB O'Neill, D TI Uniform texture in meter-long YBa2Cu3O7 tape SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE coated conductor; texture; YBCO; long length; RABiTS ID COATED CONDUCTORS; LENGTHS AB A reel-to-reel tape handler mounted on a four-circle diffractometer is used to provide a characterization by X-ray diffraction of the entire 1 m length of a YBa2Cu3O7/CeO2/YxZr1-xO2/CeO2/Pd/Ni (YBCO/CeO2/YSZ/CeO2/Pd/Ni) tape. Cube-textured Ni was formed by rolling and annealing; epitaxial CeO2/YSZ/CeO2/Pd buffer layers were deposited by reactive sputtering; YBCO was converted ex situ from Y, BaF2, and Cu codeposited by e-beam evaporation. Rocking curve FWHM (mean +/- standard deviation) for 95 segments of 1 cm length are: YBCO(005) = 6.2 +/- 0.5degrees, YSZ(002) = 10.4 +/- 0.4degrees, and Ni(002) = 7.6 +/- 0.30. phi scan FWHM are: YBCO(113) = 9.6 +/- 0.4degrees, YSZ(111) = 13.0 +/- 0.4degrees, and Ni(111) = 10.6 +/- 0.4degrees. Greater than 95% of the tape at each point is cube textured from Ni to YBCO. The critical current density J(c) is 0.36 +/- 0.04 MA/cm(2) at 77 K and is inversely correlated with the rocking curve FWHM. Calculations suggest that J(c) might be increased by a factor of 2.1 by producing a sharper texture and that the uniformity of the texture will support scaling to kilometer lengths. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. 3M Co, St Paul, MN 55144 USA. RP Specht, ED (reprint author), Oak Ridge Natl Lab, POB 2008,MS 6118, Oak Ridge, TN 37831 USA. RI Specht, Eliot/A-5654-2009; More, Karren/A-8097-2016 OI Specht, Eliot/0000-0002-3191-2163; More, Karren/0000-0001-5223-9097 NR 13 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 1 PY 2002 VL 382 IS 2-3 BP 342 EP 348 AR PII S0921-4534(02)01248-0 DI 10.1016/S0921-4534(02)01248-0 PG 7 WC Physics, Applied SC Physics GA 617HB UT WOS:000179355300025 ER PT J AU Chen, MH AF Chen, MH TI Dielectronic recombination for oxygenlike ions relevant to astrophysical applications SO PHYSICAL REVIEW A LA English DT Article ID IONIZATION EQUILIBRIUM; ISOELECTRONIC SEQUENCE; RATES; EXCITATION; IRON AB In the modeling of the astrophysical plasmas, the relative elemental abundance inferred from solar and stellar upper atmosphere can be affected by as much as a factor of 5 due to the uncertainties in the current dielectronic recombination (DR) rate coefficients used to analyze the spectra [Savin and Laming, Astrophys. J. 566, 1166 (2002)]. DR rate coefficients for oxygenlike ions have been identified as the most urgent needs for the astrophysical applications. In this work, we report on the calculations of DR rate coefficients for Mg V, Si VII, S IX, and Fe XIX ions which are important for the modeling of the astrophysical plasmas. The calculations are carried out in isolated resonance and distorted-wave approximations. The relevant atomic data are calculated using the multiconfigurational Dirac-Fock method. We include 2s-2p, 2p(1/2)-2p(3/2), 2l-3l('), and 1s-2p excitations and cover temperatures ranging from 0.001 eV to 10 000 eV. For low temperatures, it is essential to have accurate DR resonance energies and to include fine-structure excitations in order to obtain reliable DR rate coefficients. Good agreement with experiment has been found for Fe XIX. For Mg V, Si VII, and S IX, significant discrepancies are noted between this work and recommended rate coefficients. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chen, MH (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 24 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2002 VL 66 IS 5 AR 052715 DI 10.1103/PhysRevA.66.052715 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900073 ER PT J AU Handy, CR Tymczak, CJ Msezane, AZ AF Handy, CR Tymczak, CJ Msezane, AZ TI Regge poles and residues for singular scattering potentials SO PHYSICAL REVIEW A LA English DT Article ID ANGULAR-MOMENTUM ANALYSIS; MOLECULAR-COLLISIONS; QUANTIZATION; TRAJECTORIES; BOUNDS; ENERGY; MATRIX AB A very efficient, wave-function independent method is presented for calculating Regge-pole positions and residues, as required in the analysis of heavy-particle collisions. The generation of high-precision residues is generally regarded as a very difficult problem; however, the present approach easily solves this. Our formalism exploits the existence of a linear moments equation representation for Psi(2), after analytic continuation into the complex r plane. Indeed, for rational fraction, singular (non-Fuchsian) scattering potentials, a moments' representation proves indispensable in this regard. We illustrate our methodology using the polarization potential, V(r)=alpha(2)/r(a)+beta/r(b), a=4, beta=0. C1 Clark Atlanta Univ, Dept Phys, Atlanta, GA 30314 USA. Clark Atlanta Univ, Ctr Theoret Studies Phys Syst, Atlanta, GA 30314 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Handy, CR (reprint author), Clark Atlanta Univ, Dept Phys, Atlanta, GA 30314 USA. NR 34 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2002 VL 66 IS 5 AR 050701 DI 10.1103/PhysRevA.66.050701 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900003 ER PT J AU Knill, E AF Knill, E TI Quantum gates using linear optics and postselection SO PHYSICAL REVIEW A LA English DT Article ID COMPUTATION AB Recently it was realized that linear optics and photodetectors with feedback can be used for theoretically efficient quantum information processing. The first of three steps toward efficient linear optics quantum computation is to design a simple postselected gate that implements a nonlinear phase shift on one mode. Here a computational strategy is given for finding postselected gates for bosonic qubits with helper photons. A more efficient conditional sign flip gate is obtained. What is the maximum efficiency for such gates? This question is posed and it is shown that the probability of success cannot be 1. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Knill, E (reprint author), Los Alamos Natl Lab, MS B256, Los Alamos, NM 87545 USA. NR 12 TC 54 Z9 54 U1 0 U2 5 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 NOV PY 2002 VL 66 IS 5 AR 052306 DI 10.1103/PhysRevA.66.052306 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900029 ER PT J AU Lushnikov, PM AF Lushnikov, PM TI Collapse of Bose-Einstein condensates with dipole-dipole interactions SO PHYSICAL REVIEW A LA English DT Article ID DYNAMICS; MOLECULES; FORCES; GASES; ATOMS AB The dynamics of Bose-Einstein condensates of a gas of bosonic particles with long-range dipole-dipole interactions in a harmonic trap is studied. Sufficient analytical criteria are found both for catastrophic collapse of Bose-Einstein condensates and for long-time condensate existence. Analytical criteria are compared with variational analysis. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. LD Landau Theoret Phys Inst, Moscow 117334, Russia. RP Lushnikov, PM (reprint author), Los Alamos Natl Lab, Div Theoret, MS-B284, Los Alamos, NM 87545 USA. RI Lushnikov, Pavel/I-2304-2013 NR 27 TC 48 Z9 48 U1 0 U2 2 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 NOV PY 2002 VL 66 IS 5 AR 051601 DI 10.1103/PhysRevA.66.051601 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900008 ER PT J AU Safronova, UI Johnson, WR Safronova, MS Albritton, JR AF Safronova, UI Johnson, WR Safronova, MS Albritton, JR TI Relativistic many-body calculations of transition rates from core-excited states in sodiumlike ions SO PHYSICAL REVIEW A LA English DT Article ID DOUBLE-ELECTRON CAPTURE; INNER-SHELL EXCITATION; NA-LIKE IONS; ISOELECTRONIC SEQUENCE; OSCILLATOR-STRENGTHS; THEORETICAL-ANALYSIS; SATELLITE SPECTRA; ATOM COLLISIONS; 3LNL' STATES; FE-XVII AB Rates and line strengths are calculated for the 2s(2)2p(5)3l3l(')-2s(2)2p(6)3l(') and 2s2p(6)3l3l(')-2s(2)2p(6)3l(') electric-dipole (E1) transitions in Na-like ions with nuclear charges ranging from Z=14 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded E1 matrix elements in length and velocity forms. The calculations start from a 1s(2)2s(2)2p(6) Dirac-Fock potential. First-order RMBPT is used to obtain intermediate coupling coefficients and second-order RMBPT is used to calculate transition matrix elements. A detailed discussion of the various contributions to dipole matrix elements is given for sodiumlike copper (Z=29). Transition energies used in the calculation of transition rates are from second-order RMBPT. Trends of transition rates as functions of Z are shown graphically for selected transitions. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46566 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Safronova, UI (reprint author), Univ Notre Dame, Dept Phys, 225 Nieuwland Sci Hall, Notre Dame, IN 46566 USA. NR 31 TC 10 Z9 10 U1 0 U2 0 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 NOV PY 2002 VL 66 IS 5 AR 052511 DI 10.1103/PhysRevA.66.052511 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900058 ER PT J AU Trabert, E Beiersdorfer, P Gwinner, G Pinnington, EH Wolf , A AF Trabert, E Beiersdorfer, P Gwinner, G Pinnington, EH Wolf , A TI M1 transition rate in Cl12+ from an electron-beam ion trap and heavy-ion storage ring SO PHYSICAL REVIEW A LA English DT Article ID BORON ISOELECTRONIC SEQUENCE; CHARGE STATES; B-LIKE; INTERCOMBINATION; CONFIGURATIONS; BERYLLIUM; EMISSION; LIFETIME; LINES; EBIT AB The transition probability of the magnetic dipole (M1) transition 2s(2)2p P-2(o) J=1/2 to J(')=3/2 (lambda=574.19 nm) in the B-like ion Cl12+ has been measured using two different light sources, the Heidelberg heavy-ion storage ring TSR and the Livermore electron-beam ion trap EBIT-I. Our results for the atomic level lifetime are 21.2+/-0.6 ms from the heavy-ion storage ring and 21.0+/-0.5 ms from the Livermore electron-beam ion trap. Particular attention has been paid to systematic errors, making this experiment a common reference for atomic level lifetime measurements in the visible spectrum. C1 Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany. Lawrence Livermore Natl Lab, Div Phys & Adv Technol, Livermore, CA 94550 USA. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. RP Trabert, E (reprint author), Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany. NR 32 TC 31 Z9 31 U1 0 U2 2 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 NOV PY 2002 VL 66 IS 5 AR 052507 DI 10.1103/PhysRevA.66.052507 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900054 ER PT J AU Vetter, PA Freedman, SJ AF Vetter, PA Freedman, SJ TI Branching-ratio measurements of multiphoton decays of positronium SO PHYSICAL REVIEW A LA English DT Article ID CHARGE-CONJUGATION INVARIANCE; 4 PHOTONS; ORTHOPOSITRONIUM; GAMMASPHERE; SEARCH; REST AB Positronium (Ps) decay to four- and five-photon final states has been measured. From a sample of 3.73x10(9) detected events of Ps annihilation, the QED-allowed branching ratios of para-Ps to four photons R-4=1.14(33)(21)x10(-6) (stat., sys., 68% C.L.), and ortho-Ps to five photons R-5=1.67(99)(37)x10(-6) (68% C.L.) were measured. No charge-conjugation symmetry violating events were observed, establishing a branching ratio limit for (o-Ps-->4gamma) of R-4(C)<3.7x10(-6) (90% C.L.) and a new limit for (p-Ps-->5gamma) of R-5(C)<2.7x10(-7) (90% C.L.). The experiment was performed using the Gammasphere array of Compton-suppressed high-purity germanium detectors. Gammasphere's segmentation, high efficiency, and excellent energy resolution allowed event discrimination sufficient to observe the rare decay modes in the presence of substantial backgrounds. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Vetter, PA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. NR 24 TC 8 Z9 8 U1 2 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 NOV PY 2002 VL 66 IS 5 AR 052505 DI 10.1103/PhysRevA.66.052505 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 622DU UT WOS:000179631900052 ER PT J AU Alamoudi, SM Boyanovsky, D Wang, SY AF Alamoudi, SM Boyanovsky, D Wang, SY TI Nonequilibrium relaxation in neutral BCS superconductors: Ginzburg-Landau approach with Landau damping in real time SO PHYSICAL REVIEW B LA English DT Article ID DEPENDENT EFFECTIVE THEORY; D-WAVE SUPERCONDUCTORS; FINITE-TEMPERATURE; PHASE FLUCTUATIONS; ORDER-PARAMETER; FERMI GAS; FIELD; SUPERFLUID; DYNAMICS; EQUILIBRIUM AB We present a field-theoretical method to obtain consistently the equations of motion for small amplitude fluctuations of the order parameter directly in real time for a homogeneous, neutral BCS superconductor. This method allows to study the nonequilibrium relaxation of the order parameter as an initial value problem. We obtain the Ward identities and the effective actions for small phase the amplitude fluctuations to one-loop order. Focusing on the long wavelength, low-frequency limit near the critical point, we obtain the time-dependent Ginzburg-Landau effective action to one-loop order, which is nonlocal as a consequence of Landau damping. The nonequilibrium relaxation of the phase and amplitude fluctuations is studied directly in real time. The long-wavelength phase fluctuation (Bogoliubov-Anderson-Goldstone mode) is overdamped by Landau damping and the relaxation time scale diverges at the critical point, revealing critical slowing down. C1 King Fahd Univ Petr & Minerals, Dept Phys, Dhahran 31261, Saudi Arabia. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Boyanovsky, D (reprint author), King Fahd Univ Petr & Minerals, Dept Phys, Dhahran 31261, Saudi Arabia. EM alamoudi@kfupm.edu.sa; boyan@pitt.edu; swang@lanl.gov NR 55 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 NOV 1 PY 2002 VL 66 IS 18 AR 184502 DI 10.1103/PhysRevB.66.184502 PG 23 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100074 ER PT J AU Beleggia, M Pozzi, G Masuko, J Osakabe, N Harada, K Yoshida, T Kamimura, O Kasai, H Matsuda, T Tonomura, A AF Beleggia, M Pozzi, G Masuko, J Osakabe, N Harada, K Yoshida, T Kamimura, O Kasai, H Matsuda, T Tonomura, A TI Interpretation of Lorentz microscopy observations of vortices in high-temperature superconductors with columnar defects SO PHYSICAL REVIEW B LA English DT Article ID VORTEX LATTICES; FLUXONS; IMAGES AB In order to interpret recent experimental observations of superconducting vortices interacting with tilted columnar defects in high-temperature superconducting materials, we have extended to the case of anisotropic materials our Fourier space approach for the calculation of the electron optical phase shift experienced by the high-energy electrons in a transmission electron microscope. The case of a London vortex having its core not perpendicular to the specimen surfaces is considered. The same configuration is also analyzed in the framework of a simplified pancake model and the influence of the number of stacks on the phase shift and images is investigated. The results obtained by the two models are compared between them and with the experimental results. The agreement between theory and experiment confirms that anisotropy plays a major role in affecting the electron microscopy images. C1 Univ Bologna, Dept Phys, I-40127 Bologna, Italy. Univ Bologna, Ist Nazl Fis Mat, I-40127 Bologna, Italy. Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. Hitachi Ltd, Adv Res Lab, Hatoyama, Saitama 3500395, Japan. RIKEN, Inst Phys & Chem Res, Frontier Res Syst, Wako, Saitama 3510198, Japan. Japan Sci & Technol Corp, SORST, Chuo Ku, Tokyo 1030027, Japan. RP Beleggia, M (reprint author), Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. NR 17 TC 17 Z9 17 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174518 DI 10.1103/PhysRevB.66.174518 PG 10 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700102 ER PT J AU Bulaevskii, LN Helm, C AF Bulaevskii, LN Helm, C TI Field dependence of the Josephson plasma resonance in layered superconductors with alternating junctions SO PHYSICAL REVIEW B LA English DT Article ID CUPRATE SUPERCONDUCTORS; VORTEX LATTICE; SMLA0.8SR0.2CUO4-DELTA; OSCILLATIONS; PHASE; MODE AB The Josephson plasma resonance in layered superconductors with alternating critical current densities is investigated in a low perpendicular magnetic field. In the vortex solid phase the current densities and the squared bare plasma frequencies decrease linearly with the magnetic field. Taking into account the coupling due to charge fluctuations on the layers, we extract from recent optical data for SmLa1-xSrxCuO4-delta the Josephson penetration length lambda(ab)approximate to1100 A parallel to the layers at T=10 K. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. ETH Honggerberg, Inst Theoret Phys, CH-8093 Zurich, Switzerland. RP Bulaevskii, LN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 26 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 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174505 DI 10.1103/PhysRevB.66.174505 PG 5 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700089 ER PT J AU Crew, DC Girt, E Suess, D Schrefl, T Krishnan, KM Thomas, G Guilot, M AF Crew, DC Girt, E Suess, D Schrefl, T Krishnan, KM Thomas, G Guilot, M TI Magnetic interactions and reversal behavior of Nd2Fe14B particles diluted in a Nd matrix SO PHYSICAL REVIEW B LA English DT Article ID FE-B ALLOYS; TIME-DEPENDENCE; COERCIVITY; MECHANISM; VISCOSITY; FIELDS; NDFEB AB Reversible magnetization measurements, micromagnetic modeling, the temperature dependence of coercivity, and magnetic viscosity measurements have been used to clarify the magnetic reversal mechanism of Nd2Fe14B particles contained in a Nd matrix. The coercivity was observed to increase markedly as the dilution of the Nd2Fe14B phase was increased. The increase in coercivity was accompanied by a change in the reversal mechanism. In the least dilute samples, domain wall motion involving several grains governed by intergrain interactions was active. In the most dilute samples nonuniform reversal of individual grains was dominant, reversal occurring particle by particle and resembling the behavior of isolated Stoner-Wohlfarth particles. The value of the coercivity in the most dilute sample was in excellent agreement with micromagnetic modeling results for isolated particles when the effect of thermal activation of magnetization reversal was accounted for. Despite the single particle reversal mechanism of the most dilute samples, a linear dependence of coercivity on packing fraction was not observed. This is attributed to a clustering of the grains in the samples and changes in grain shape with composition. In all samples, regardless of dilution, the initial magnetic state after thermal demagnetization was found to be one in which a substantial proportion of grains were in a multidomain state. However, micromagnetic simulations for isolated particles of similar shape to those in the most dilute sample showed that the single domain state is the lowest energy state. It is concluded that thermal demagnetization can result in the system remaining in a local metastable state and not the global energy minimum. Micromagnetic calculations showed that one or more domain walls can arise in a grain during thermal demagnetization and that magnetostatic effects provide a significant energy barrier in zero field to the removal of a domain wall once it is formed. C1 Brookhaven Natl Lab, Dept Energy Sci & Technol, Mat & Chem Sci Div, Upton, NY 11973 USA. Univ Western Australia, Dept Phys, Nedlands, WA 6009, Australia. Seagate Technol, Fremont, CA USA. Vienna Univ Technol, Inst Appl & Tech Phys, A-1040 Vienna, Austria. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. CNRS, MPI, Lab Champs Magnet Intenses, F-38042 Grenoble, France. RP Crew, DC (reprint author), Brookhaven Natl Lab, Dept Energy Sci & Technol, Mat & Chem Sci Div, Upton, NY 11973 USA. RI Suess, Dieter/H-7475-2012 OI Suess, Dieter/0000-0001-5453-9974 NR 32 TC 14 Z9 14 U1 0 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 18 AR 184418 DI 10.1103/PhysRevB.66.184418 PG 13 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100054 ER PT J AU Gaulin, BD Mao, M Wiebe, CR Qiu, Y Shapiro, SM Broholm, C Lee, SH Garrett, JD AF Gaulin, BD Mao, M Wiebe, CR Qiu, Y Shapiro, SM Broholm, C Lee, SH Garrett, JD TI Spin and lattice excitations in the heavy-fermion superconductor UNi2Al3 SO PHYSICAL REVIEW B LA English DT Article ID INCOMMENSURATE MAGNETIC ORDER; NEUTRON-SCATTERING; ANTIFERROMAGNETIC ORDER; SYSTEM URU2SI2; SI-29 NMR; UPD2AL3; FLUCTUATIONS; PRESSURE; UPT3; TRANSITIONS AB Inelastic neutron scattering measurements have been carried out on the heavy fermion superconductor UNi2Al3. This hexagonal material orders magnetically into an incommensurate structure, characterized by the ordering wave vector Q(ord)=(1/2+/-tau, 0, 1/2) with tausimilar to0.11, below T-N=4.6 K and then superconducts below T-C=1.2 K. For energies above 2 meV, we observe quasielastic magnetic neutron scattering both near (0, 0, n/2) and in ridges along H of the form (H, 0, n/2), with n odd. This scattering has a characteristic energy width of similar to6 meV, and evolves on a temperature scale of similar to80 K, which is close to the coherence temperature of this heavy fermion metal. High energy resolution measurements, below 2 meV, show the spectral weight of these fluctuations to evolve from the commensurate wavevector (0, 0, n/2), with n odd, to the material's incommensurate ordering wave vector as the energy of the fluctuations decreases. This observation is particularly interesting in light of the fact that UNi2Al3's isostructural sister heavy fermion superconductor, UPd2Al3, orders into a commensurate antiferromagnetic structure with this same (0, 0, n/2) wave vector. A search for inelastic magnetic scattering associated with the superconducting phase transition, as has been observed in UPd2Al3, revealed no additional scattering at the incommensurate ordering wavevector and energies above 0.10 meV. Measurements of the low-lying acoustic phonons were also performed, and show zone boundary energies lying in the range 10-13 meV. C1 McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Canadian Inst Adv Res, Toronto, ON M5G 1Z8, Canada. RP McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. RI Broholm, Collin/E-8228-2011; Piper, Walter/B-7908-2009 OI Broholm, Collin/0000-0002-1569-9892; NR 33 TC 5 Z9 5 U1 0 U2 7 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 NOV 1 PY 2002 VL 66 IS 17 AR 174520 DI 10.1103/PhysRevB.66.174520 PG 9 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700104 ER PT J AU Jung, CU Kim, JY Chowdhury, P Kim, KHP Lee, SI Koh, DS Tamura, N Caldwell, WA Patel, JR AF Jung, CU Kim, JY Chowdhury, P Kim, KHP Lee, SI Koh, DS Tamura, N Caldwell, WA Patel, JR TI Microstructure and pinning properties of hexagonal-disc shaped single crystalline MgB2 SO PHYSICAL REVIEW B LA English DT Article ID ANISOTROPIC SUPERCONDUCTING PROPERTIES; MAGNESIUM DIBORIDE; TEMPERATURE; TRANSPORT AB We synthesized hexagonal-disc-shaped MgB2 single crystals under high-pressure conditions and analyzed the microstructure and pinning properties. The lattice constants and the Laue pattern of the crystals from x-ray micro-diffraction showed the crystal symmetry of MgB2. A thorough crystallographic mapping within a single crystal showed that the edge and c axis of hexagonal-disc shape exactly matched the [10 (1) over bar0] and the [0001] directions of the MgB2 phase. Thus, these well-shaped single crystals may be the best candidates for studying the direction dependences of the physical properties. The magnetization curve and the magnetic hysteresis curve for these single crystals showed the existence of a wide reversible region and weak pinning properties, which supported our single crystals being very clean. C1 Pohang Univ Sci & Technol, Natl Creat Res Initiat Ctr Superconduct, Pohang 790784, South Korea. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Stanford Univ, Stanford Linear Accelerator Ctr, SSRL, Stanford, CA 94309 USA. RP Jung, CU (reprint author), ERATO, JST, AIST, Tokura Spin Superstruct Project, Tsukuba Cent 4, Tsukuba, Ibaraki 3058562, Japan. NR 26 TC 20 Z9 20 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 18 AR 184519 DI 10.1103/PhysRevB.66.184519 PG 5 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100091 ER PT J AU Kenzelmann, M Cowley, RA Buyers, WJL Coldea, R Enderle, M McMorrow, DF AF Kenzelmann, M Cowley, RA Buyers, WJL Coldea, R Enderle, M McMorrow, DF TI Evolution of spin excitations in a gapped antiferromagnet from the quantum to the high-temperature limit SO PHYSICAL REVIEW B LA English DT Article ID DIMENSIONAL HEISENBERG-ANTIFERROMAGNET; HALDANE-GAP; NEUTRON-SCATTERING; MONTE-CARLO; S=1 CHAIN; CSNICL3; DYNAMICS; STATE; PHASE; TRANSITIONS AB We have mapped from the quantum to the classical limit the spin excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain system CsNiCl3 in its paramagnetic phase from T=5 to 200 K. Neutron scattering shows that the excitations are resonant and dispersive up to at least T=70 Ksimilar or equal to2.7J, but broaden considerably with increasing temperature. The dispersion flattens out with increasing temperature as the resonance energy Delta at the antiferromagnetic wave vector increases and the maximum in the dispersion decreases. The correlation length xi between T=12 and 50 K is in agreement with quantum Monte Carlo calculations for the spin-1 chain. xi is also consistent with the single mode approximation, suggesting that the excitations are short-lived single particle excitations. Below T=12 K where three-dimensional spin correlations are important, xi is shorter than predicted and the experiment is not consistent with the random phase approximation for coupled quantum chains. At T=200 K, the structure factor and second energy moment of the excitation spectrum are in excellent agreement with the high-temperature series expansion. C1 Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Natl Res Council Canada, Neutron Program Mat Res, Chalk River, ON K0J 1J0, Canada. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Univ Saarland, D-66123 Saarbrucken, Germany. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Riso Natl Lab, Condensed Matter Phys & Chem Dept, DK-4000 Roskilde, Denmark. RP Kenzelmann, M (reprint author), Univ Oxford, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. RI McMorrow, Desmond/C-2655-2008; Enderle, Mechthild/E-8832-2014; Kenzelmann, Michel/A-8438-2008 OI McMorrow, Desmond/0000-0002-4947-7788; Enderle, Mechthild/0000-0001-7304-2162; Kenzelmann, Michel/0000-0001-7913-4826 NR 44 TC 9 Z9 9 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174412 DI 10.1103/PhysRevB.66.174412 PG 14 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700056 ER PT J AU Langer, J Dunn, JH Hahlin, A Karis, O Sellmann, R Arvanitis, D Maletta, H AF Langer, J Dunn, JH Hahlin, A Karis, O Sellmann, R Arvanitis, D Maletta, H TI Cap layer influence on the spin reorientation transition in Au/Co/Au SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC CIRCULAR-DICHROISM; ULTRATHIN COBALT FILMS; X-RAY; MICROSCOPIC ORIGIN; PERPENDICULAR ANISOTROPY; CO FILMS; CO/AU(111); CU AB X-ray magnetic circular dichroism vector magnetometry provides evidence that the spin reorientation transition in epitaxially grown Au/Co/Au films depends on the thickness of the Au capping layer. Whereas a 1.9-nm-thick Co film with a 2-nm Au cap exhibits the expected pure in-plane orientation of the magnetization in the remanent state at room temperature, the same film with thinner Au cap shows a significant out-of-plane component. These findings are linked with the observation of a cap-induced enhancement of the orbital moment of about 0.05mu(B) per Co atom. C1 Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Uppsala, S-75121 Uppsala, Sweden. RP Maletta, H (reprint author), Hahn Meitner Inst Berlin GmbH, Glienicker Str 100, D-14109 Berlin, Germany. NR 22 TC 16 Z9 16 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 172401 DI 10.1103/PhysRevB.66.172401 PG 4 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700002 ER PT J AU Lopatin, AV Ioffe, LB AF Lopatin, AV Ioffe, LB TI Structural glass on a lattice in the limit of infinite dimensions SO PHYSICAL REVIEW B LA English DT Article ID RANGE JOSEPHSON ARRAY; SPIN-GLASS; MEAN-FIELD; MODEL; THERMODYNAMICS; SYSTEMS AB We construct a mean-field theory for the lattice model of a structural glass and solve it using the replica method and one-step replica symmetry breaking ansatz; this theory becomes exact in the limit of infinite dimensions. Analyzing the stability of this solution we conclude that the metastable states remain uncorrelated in a finite temperature range below the transition, but become correlated at a certain low temperature; below this temperature metastable states bifurcate and the one step replica symmetry breaking solution fails. We find dynamic and thermodynamic transition temperatures as functions of the density, and construct a full thermodynamic description of a typical physical process in which the system is trapped in one metastable state when cooled below the vitrification temperature. We find that for such physical process the entropy and pressure at the glass transition are continuous across the transition, while their temperature derivatives have jumps. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Rutgers State Univ, Dept Phys & Astron, Ctr Mat Theory, Piscataway, NJ 08854 USA. RP Lopatin, AV (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 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 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174202 DI 10.1103/PhysRevB.66.174202 PG 5 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700034 ER PT J AU Lyard, L Samuely, P Szabo, P Klein, T Marcenat, C Paulius, L Kim, KHP Jung, CU Lee, HS Kang, B Choi, S Lee, SI Marcus, J Blanchard, S Jansen, AGM Welp, U Karapetrov, G Kwok, WK AF Lyard, L Samuely, P Szabo, P Klein, T Marcenat, C Paulius, L Kim, KHP Jung, CU Lee, HS Kang, B Choi, S Lee, SI Marcus, J Blanchard, S Jansen, AGM Welp, U Karapetrov, G Kwok, WK TI Anisotropy of the upper critical field and critical current in single crystal MgB2 SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTIVITY; GAPS AB We report on specific-heat, high-magnetic-field transport, and ac-susceptibility measurements on MgB2 single crystals. The upper critical field for magnetic fields perpendicular and parallel to the basal planes is presented in the entire temperature range. A very different temperature dependence has been observed in the two directions, which yields a temperature-dependent anisotropy with Gammasimilar to5 at low temperatures and similar to2 near T-c. A peak effect is observed for mu(0)Hsimilar to2 T parallel to the c axis, and the critical current density presents a sharp maximum for H parallel to the ab plane. C1 CNRS, Etud Proprietes Elect Solides Lab, F-38042 Grenoble 9, France. CEA Grenoble, DRFMC SPSMS, F-38054 Grenoble, France. Univ Grenoble 1, F-38041 Grenoble 9, France. Slovak Acad Sci, Inst Expt Phys, SK-04353 Kosice, Slovakia. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. Pohang Univ Sci & Technol, NVCRICS, Pohang 790784, South Korea. CNRS, MPI, Grenoble High Magnet Field Lab, F-38042 Grenoble 9, France. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lyard, L (reprint author), CNRS, Etud Proprietes Elect Solides Lab, Boite Postale 166, F-38042 Grenoble 9, France. RI Karapetrov, Goran/C-2840-2008 OI Karapetrov, Goran/0000-0003-1113-0137 NR 30 TC 147 Z9 149 U1 0 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 18 AR 180502 DI 10.1103/PhysRevB.66.180502 PG 4 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100008 ER PT J AU Matsuda, M Fujita, M Yamada, K Birgeneau, RJ Endoh, Y Shirane, G AF Matsuda, M Fujita, M Yamada, K Birgeneau, RJ Endoh, Y Shirane, G TI Magnetic field effects and magnetic anisotropy in lightly doped La2-xSrxCuO4 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; T-J(Z) MODEL; SPIN; LA2CUO4; ORDER; TRANSITION; EXCHANGE AB The effects of the application of a magnetic field on the diagonal stripe spin-glass phase is studied in lightly doped La2-xSrxCuO4 (x=0.014 and 0.024). With increasing magnetic field, the magnetic elastic intensity at the diagonal incommensurate (DIC) positions (1,+/-epsilon,0) decreases as opposed to the increase seen in superconducting samples. This diminution in intensity with increasing magnetic field originates from a spin reorientation transition, which is driven by the antisymmetric exchange term in the spin Hamiltonian. On the other hand, the transition temperature, the incommensurability, and the peak width of the diagonal incommensurate correlations are not changed with magnetic field. This result suggests that the magnetic correlations are determined primarily by the charge disproportionation and that the geometry of the diagonal incommensurate magnetism is also determined by effects-that is, stripe formation-which are not purely magnetic in origin. The Dzyaloshinskii-Moriya antisymmetric exchange is nevertheless important in determining the local spin structure in the DIC stripe phase. C1 Japan Atom Energy Res Inst, Adv Ctr Res Ctr, Ibaraki 3191195, Japan. Kyoto Univ, Inst Chem Res, Uji 6100011, Japan. Univ Toronto, Dept Phys, Toronto, ON M5S 1A1, Canada. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Matsuda, M (reprint author), Japan Atom Energy Res Inst, Adv Ctr Res Ctr, Ibaraki 3191195, Japan. RI Yamada, Kazuyoshi/C-2728-2009; Fujita, Masaki/D-8430-2013; Matsuda, Masaaki/A-6902-2016 OI Matsuda, Masaaki/0000-0003-2209-9526 NR 21 TC 11 Z9 11 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174508 DI 10.1103/PhysRevB.66.174508 PG 6 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700092 ER PT J AU Millis, AJ Morr, DK Schmalian, J AF Millis, AJ Morr, DK Schmalian, J TI Quantum Griffiths effects in metallic systems SO PHYSICAL REVIEW B LA English DT Article ID FERMI-LIQUID BEHAVIOR; ISING SPIN-GLASS; PHASE; SINGULARITIES; ELECTRON; INSTABILITY; DISORDER; CHAINS AB Elementary analytical extremal statistics arguments are used to analyze the possibility of quantum Griffiths effects in nearly critical systems with overdamped dynamics, such as arise in conventional theories of metallic quantum criticality. The overdamping is found to strongly suppress quantum tunneling of rare regions, leading to superparamagnetic rather than quantum Griffiths behavior. Implications for theories of non-Fermi-liquid behavior in heavy-fermion materials are discussed. C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Millis, AJ (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. RI Schmalian, Joerg/H-2313-2011 NR 26 TC 52 Z9 52 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 NOV 1 PY 2002 VL 66 IS 17 AR 174433 DI 10.1103/PhysRevB.66.174433 PG 10 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700077 ER PT J AU Mittal, R Chaplot, SL Kolesnikov, AI Loong, CK Jayakumar, OD Kulshreshtha, SK AF Mittal, R Chaplot, SL Kolesnikov, AI Loong, CK Jayakumar, OD Kulshreshtha, SK TI Inelastic neutron scattering, lattice dynamics, and synchrotron x-ray diffraction study of FePO4 SO PHYSICAL REVIEW B LA English DT Article ID NEGATIVE THERMAL-EXPANSION; INDUCED PHASE-TRANSITION; HIGH-PRESSURE BEHAVIOR; CRYSTAL-STRUCTURE; QUARTZ; ALPHA-ALPO4; ZRW2O8; BERLINITE; GLASS; GAPO4 AB The quartz structure compounds MPO4 (M=Al, Fe, and Ga) are of interest to understand the nature of bonding in the tetrahedral coordinated phosphates. We report detailed lattice dynamical studies involving experimental inelastic neutron scattering measurements and theoretical shell model calculations of vibrational and thermodynamic properties of FePO4. X-ray diffraction measurements are also carried out for FePO4 from 100 to 300 K using an Elettra synchrotron radiation source. The measured phonon density of states and thermal expansion for FePO4 have been interpreted based on the shell model calculations. The lattice dynamical model is used for calculating various thermodynamic properties like specific heat, thermal expansion, bulk modulus, and thermal amplitudes. The calculations are in good agreement with numerous experimental data including our phonon density of states and thermal expansion measurements. Our calculated pressure variation of phonon frequencies shows that a zone boundary mode at (1/3, 1/3, 0) becomes soft at 4 GPa, which may be associated with the mechanical instability of the quartz structure of FePO4 at high pressure. C1 Bhabha Atom Res Ctr, Div Solid State Phys, Mumbai 400085, India. Argonne Natl Lab, Intense Pulsed Neutron Source Div, Argonne, IL 60439 USA. Bhabha Atom Res Ctr, Novel Mat & Struct Chem Div, Mumbai 400085, India. RP Mittal, R (reprint author), Bhabha Atom Res Ctr, Div Solid State Phys, Mumbai 400085, India. RI Kolesnikov, Alexander/I-9015-2012 OI Kolesnikov, Alexander/0000-0003-1940-4649 NR 36 TC 14 Z9 14 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174304 DI 10.1103/PhysRevB.66.174304 PG 7 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700041 ER PT J AU Nakao, H Wakabayashi, Y Kiyama, T Murakami, Y von Zimmermann, M Hill, JP Gibbs, D Ishihara, S Taguchi, Y Tokura, Y AF Nakao, H Wakabayashi, Y Kiyama, T Murakami, Y von Zimmermann, M Hill, JP Gibbs, D Ishihara, S Taguchi, Y Tokura, Y TI Quantitative determination of the atomic scattering tensor in orbitally ordered YTiO3 by using a resonant x-ray scattering technique SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL OXIDES; CHARGE; LAMNO3; MANGANITES; LA0.5SR1.5MNO4; INTERPLAY; PHASE AB The orbitally ordered state of YTiO3 has been investigated utilizing resonant x-ray scattering (RXS) near the Ti K-edge. The RXS intensities have been observed at the 1s-->4p dipole transition energy (the main edge). The atomic scattering tensor of the Ti ion has quantitatively been determined by measurements of the azimuthal angle and polarization dependence of the signal at several scattering vectors. On the basis of the tensor, we discuss not only the scattering mechanism but also the wave function of the orbitally ordered state, finding it to be a linear combination of two t(2g) orbitals. In addition, RXS at the 1s-->3d transition energy (the pre-edge) was also observed. This signal was found to have the same azimuthal angle and polarization dependence as that at the main edge. C1 KEK, High Energy Accelerator Res Org, Inst Mat Struct Sci, Photon Factory, Tsukuba, Ibaraki 3050801, Japan. Japan Sci & Technol Corp, CREST, Tsukuba, Ibaraki 3050045, Japan. Keio Univ, Dept Phys, Yokohama, Kanagawa 2238522, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Tokyo 1138656, Japan. JRCAT, Tsukuba, Ibaraki 305, Japan. RP Nakao, H (reprint author), Tohoku Univ, Grad Sch Sci, Sendai, Miyagi 9808578, Japan. RI Taguchi, Yasujiro/A-3048-2010; Wakabayashi, Yusuke/F-1621-2010; Tokura, Yoshinori/C-7352-2009 OI Wakabayashi, Yusuke/0000-0003-3107-0338; NR 33 TC 54 Z9 54 U1 1 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 18 AR 184419 DI 10.1103/PhysRevB.66.184419 PG 7 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100055 ER PT J AU Papadopolos, Z Kasner, G Ledieu, J Cox, EJ Richardson, NV Chen, Q Diehl, RD Lograsso, TA Ross, AR McGrath, R AF Papadopolos, Z Kasner, G Ledieu, J Cox, EJ Richardson, NV Chen, Q Diehl, RD Lograsso, TA Ross, AR McGrath, R TI Bulk termination of the quasicrystalline fivefold surface of Al70Pd21Mn9 SO PHYSICAL REVIEW B LA English DT Article ID ENERGY-ELECTRON DIFFRACTION; ALPDMN ICOSAHEDRAL PHASE; AL-PD-MN; AL68PD23MN9; MICROSCOPY; LATTICES; LEED; STM AB The structure of the Al70Pd21Mn9 surface has been investigated using high-resolution scanning tunneling microscopy. From two large fivefold terraces on the surface in a short decorated Fibonacci sequence, atomically resolved surface images have been obtained. One of these terraces carries a rare local configuration in the form of a ring. The location of the corresponding sequence of terminations in the bulk model M of icosahedral i-AlPdMn based on the three-dimensional tiling T-*(2F) of an F phase has been estimated using this ring configuration and the requirement from low-energy electron diffraction work of Gierer that the average atomic density of the terminations is 0.136 atoms per Angstrom(2). A termination contains two atomic plane layers separated by a vertical distance of 0.48 Angstrom. The position of the bulk terminations is fixed within the layers of Bergman polytopes in the model M: they are 4.08 Angstrom in the direction of the bulk from a surface of the most dense Bergman layers. From the coding windows of the top planes in terminations in M we conclude that a Penrose (P1) tiling is possible on almost all fivefold terraces. The shortest edge of the tiling P1 is either 4.8 or 7.8 Angstrom. The experimentally derived tiling of the surface with the ring configuration has an edge length of 8.0+/-0.3 Angstrom and hence matches the minimal edge length expected from the model. C1 Univ Magdeburg, Inst Theoret Phys, D-39016 Magdeburg, Germany. Univ Liverpool, Surface Sci Res Ctr, Liverpool L69 3BX, Merseyside, England. Univ St Andrews, Dept Chem, St Andrews KY16 9AJ, Fife, Scotland. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Liverpool, Dept Phys, Liverpool L69 3BX, Merseyside, England. RP Univ Magdeburg, Inst Theoret Phys, PSF 4120, D-39016 Magdeburg, Germany. EM zorka.papadopolos@uni-tuebingen.de RI McGrath, Ronan/A-1568-2009; Ledieu, Julian/F-1430-2010 OI McGrath, Ronan/0000-0002-9880-5741; NR 43 TC 91 Z9 91 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 NOV 1 PY 2002 VL 66 IS 18 AR 184207 DI 10.1103/PhysRevB.66.184207 PG 13 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100029 ER PT J AU Reichhardt, C Reichhardt, CJO AF Reichhardt, C Reichhardt, CJO TI Dynamical behaviors of quasi-one-dimensional vortex states: Possible applications to the vortex chain state SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-FLUX PENETRATION; SUPERCONDUCTING FILMS; TWIN BOUNDARIES; PERIODIC MEDIA; LATTICES; FLOW; YBA2CU3O7-DELTA; VORTICES; ARRAY; CHANNELS AB We examine the motion of one-dimensional (1D) vortex matter embedded in a 2D vortex system with weak pinning using numerical simulations. We confirm the conjecture of Matsuda [Science 294, 2136 (2001)] that the onset of the temperature induced motion of the chain is due to an incommensuration effect of the chain with the periodic potential created by the bulk vortices. In addition, under an applied driving force we find a two stage depinning transition, where the initial depinning of the vortex chain occurs through solitonlike pulses. When an ac drive is added to the dc drive, we observe phase locking of the moving vortex chain. C1 Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Reichhardt, C (reprint author), Los Alamos Natl Lab, CNLS, POB 1663, Los Alamos, NM 87545 USA. OI Reichhardt, Cynthia/0000-0002-3487-5089 NR 33 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 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 172504 DI 10.1103/PhysRevB.66.172504 PG 4 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700016 ER PT J AU Sasagawa, T Mang, PK Vajk, OP Kapitulnik, A Greven, M AF Sasagawa, T Mang, PK Vajk, OP Kapitulnik, A Greven, M TI Bulk magnetic properties and phase diagram of Li-doped La2CuO4: Common magnetic response of hole-doped CuO2 planes SO PHYSICAL REVIEW B LA English DT Article ID MUON-SPIN-ROTATION; HIGH-TEMPERATURE SUPERCONDUCTORS; SELF-GENERATED RANDOMNESS; SINGLE-CRYSTALS; LA-139 NQR; ANTIFERROMAGNETIC ORDER; STRIPE GLASSES; LA2-XSRXCUO4; SR; SYSTEM AB Although La2Cu1-xLixO4 (Li-LCO) differs from La2-xSrxCuO4 (Sr-LCO) in many ways (e.g., the absence of metallic transport, high-T-c superconductivity, and incommensurate antiferromagnetic correlations), it has been known that certain magnetic properties are remarkably similar. The present work establishes the detailed bulk magnetic phase diagram of Li-LCO (0less than or equal toxless than or equal to0.07), which is found to be nearly identical to that of lightly-doped Sr-LCO, and therefore extends the universality of the phase diagram to hole-doped but nonsuperconducting cuprates. C1 Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, Tokyo 1130033, Japan. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan. RI Sasagawa, Takao/E-6666-2014 OI Sasagawa, Takao/0000-0003-0149-6696 NR 37 TC 14 Z9 14 U1 0 U2 0 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 NOV 1 PY 2002 VL 66 IS 18 AR 184512 DI 10.1103/PhysRevB.66.184512 PG 5 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100084 ER PT J AU Soderlind, P AF Soderlind, P TI Comment on "Theoretical prediction of phase transition in gold" SO PHYSICAL REVIEW B LA English DT Editorial Material ID BAND; SYSTEMS AB The structural properties of compressed gold are studied from first-principles theory. A new bcc phase is predicted to be stable as the ultimate high-pressure phase and not the hcp phase that was suggested by Ahuja [Phys. Rev. B 63, 212101 (2001)]. Semicore 5p states are broadened under high pressures and begin to hybridize with the 5d band and this modification of the electronic structure favors the bcc over the fcc and hcp structures at megabar pressures. C1 Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. RP Soderlind, P (reprint author), Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. NR 8 TC 0 Z9 0 U1 2 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 176201 DI 10.1103/PhysRevB.66.176201 PG 2 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700106 ER PT J AU Swenson, CA Lograsso, TA Ross, AR Anderson, NE AF Swenson, CA Lograsso, TA Ross, AR Anderson, NE TI Linear thermal expansivity (1-300 K), specific heat (1-108 K), and electrical resistivity of the icosahedral quasicrystal i-Al61.4Cu25.4Fe13.2 SO PHYSICAL REVIEW B LA English DT Article ID AL-CU-FE; DENSITY-OF-STATES; INELASTIC NEUTRON-SCATTERING; ALCUFE QUASI-CRYSTALS; METAL-INSULATOR-TRANSITION; TEMPERATURE SPECIFIC-HEAT; HIGH STRUCTURAL QUALITY; ELECTRONIC-PROPERTIES; SINGLE GRAINS; LI-CU AB Linear thermal expansivity (alpha, 1-300 K), heat capacity (C-p, 1-108 K), and electrical resistivity (rho, 1-300 K) measurements are reported for single grain i-Al61.4Cu25.4Fe13.2 quasicrystals as a function of sample processing. While rho(T) is sensitive to sample treatment, both C-p and alpha are relatively insensitive (to a few percent) except at the lowest temperatures (below 4 K), where an inverse correlation between rho and the electronic C-p coefficient gamma appears to exist. Dispersion effects (deviations from Debye-like behavior) in both C-p and the lattice Gruneisen parameter Gamma are large and comparable with those for single grain i-Al71Pd21Mn08 quasicrystal and its Al72Pd25Mn03 approximant [Phys. Rev. B 65, 184206 (2002)]. Since the 0-K Debye temperature [Theta(0)=536(2) K] is in reasonable agreement with that from 4-K elastic constants [548(8) K], a previous postulate for AlPdMn that these large dispersion effects are associated with high dispersion lattice modes in off-symmetry directions also appears to apply to i-Al-Cu-Fe. A comparison with other C-p data suggests that the major effects of sample treatment (and composition) are reflected, with a few exceptions, in the values of gamma, with remarkably similar lattice contributions. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Swenson, CA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 55 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 18 AR 184206 DI 10.1103/PhysRevB.66.184206 PG 11 WC Physics, Condensed Matter SC Physics GA 622EG UT WOS:000179633100028 ER PT J AU Varela, M Grogger, W Arias, D Sefrioui, Z Leon, C Vazquez, L Ballesteros, C Krishnan, KM Santamaria, J AF Varela, M Grogger, W Arias, D Sefrioui, Z Leon, C Vazquez, L Ballesteros, C Krishnan, KM Santamaria, J TI Effects of epitaxial strain on the growth mechanism in YBa2Cu3O7-x thin films in YBa2Cu3O7-x/PrBa2Cu3O7 superlattices SO PHYSICAL REVIEW B LA English DT Article ID CRITICAL CURRENTS; RESOLUTION; TEMPERATURE; LAYERS; IMAGES AB We report on the growth mechanism of YBa2Cu3O7-x. Our study is based on an analysis of ultrathin YBa2Cu3O7-x (YBCO) layers in c-axis-oriented YBa2Cu3O7-x/PrBa2Cu3O7 superlattices. We have found that the release of epitaxial strain in very thin YBCO layers triggers a change in the dimensionality of the growth mode. Ultrathin epitaxially strained YBCO layers with thickness below 3 unit cells grow in a block-by-block two-dimensional mode that is coherent over large lateral distances. Meanwhile, when the thickness increases and the strain relaxes, layer growth turns three-dimensional, resulting in rougher layers and interfaces. C1 Univ Complutense, Dept Fis Aplicada 3, GFMC, E-28040 Madrid, Spain. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Carlos III Madrid, Dept Fis, Madrid 28911, Spain. CSIC, Inst Ciencia Mat, ICMM, E-28049 Madrid, Spain. RP Varela, M (reprint author), Univ Complutense, Dept Fis Aplicada 3, GFMC, E-28040 Madrid, Spain. RI VAZQUEZ, LUIS/A-1272-2009; Leon, Carlos/A-5587-2008; Varela, Maria/H-2648-2012; Varela, Maria/E-2472-2014; Santamaria, Jacobo/N-8783-2016; Sefrioui, Zouhair/C-2728-2017 OI VAZQUEZ, LUIS/0000-0001-6220-2810; Leon, Carlos/0000-0002-3262-1843; Varela, Maria/0000-0002-6582-7004; Santamaria, Jacobo/0000-0003-4594-2686; Sefrioui, Zouhair/0000-0002-6703-3339 NR 23 TC 12 Z9 12 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 2002 VL 66 IS 17 AR 174514 DI 10.1103/PhysRevB.66.174514 PG 6 WC Physics, Condensed Matter SC Physics GA 621VL UT WOS:000179611700098 ER PT J AU Ahle, L Akiba, Y Ashktorab, K Baker, MD Beavis, D Beery, P Britt, HC Budick, B Chang, J Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Costales, JB Crawford, HJ Cumming, JB Debbe, R Dunlop, JC Eldredge, W Engelage, J Fung, SY Garcia, E Gonin, M Gushue, S Hamagaki, H Hansen, LF Hayano, RS Hayashi, S Heintzelman, G Homma, S Judd, E Kaneko, H Kang, J Kaufman, S Kehoe, WL Kim, EJ Kumagai, A Kurita, K Ledoux, RJ Lee, JH LeVine, MJ Luke, J Miake, Y Mignerey, A Morrison, DP Morse, RJ Moskowitz, B Moulson, M Muntz, C Nagamiya, S Namboodiri, MN Nayak, TK Ogilvie, CA Olness, J Parsons, CG Remsberg, LP Roehrich, D Rothschild, P Sako, H Sakurai, H Sangster, TC Seto, R Shea, J Shigaki, K Soltz, RA Stankus, P Steadman, SG Stephans, GSF Sung, TW Tanaka, Y Tannenbaum, MJ Thomas, JH Tonse, SR Ueno-Hayashi, S van Dijk, JH Videbaek, F Vossnack, O Vutsadakis, V Wang, F Wang, Y Wegner, HE Woodruff, D Wu, Y Xiang, H Xu, GH Yagi, K Yang, X Yao, H Zachary, D Zajc, WA Zhu, F AF Ahle, L Akiba, Y Ashktorab, K Baker, MD Beavis, D Beery, P Britt, HC Budick, B Chang, J Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Costales, JB Crawford, HJ Cumming, JB Debbe, R Dunlop, JC Eldredge, W Engelage, J Fung, SY Garcia, E Gonin, M Gushue, S Hamagaki, H Hansen, LF Hayano, RS Hayashi, S Heintzelman, G Homma, S Judd, E Kaneko, H Kang, J Kaufman, S Kehoe, WL Kim, EJ Kumagai, A Kurita, K Ledoux, RJ Lee, JH LeVine, MJ Luke, J Miake, Y Mignerey, A Morrison, DP Morse, RJ Moskowitz, B Moulson, M Muntz, C Nagamiya, S Namboodiri, MN Nayak, TK Ogilvie, CA Olness, J Parsons, CG Remsberg, LP Roehrich, D Rothschild, P Sako, H Sakurai, H Sangster, TC Seto, R Shea, J Shigaki, K Soltz, RA Stankus, P Steadman, SG Stephans, GSF Sung, TW Tanaka, Y Tannenbaum, MJ Thomas, JH Tonse, SR Ueno-Hayashi, S van Dijk, JH Videbaek, F Vossnack, O Vutsadakis, V Wang, F Wang, Y Wegner, HE Woodruff, D Wu, Y Xiang, H Xu, GH Yagi, K Yang, X Yao, H Zachary, D Zajc, WA Zhu, F CA E-802 Collaboration TI System, centrality, and transverse mass dependence of two-pion correlation radii in heavy ion collisions at 11.6A and 14.6A GeV/c SO PHYSICAL REVIEW C LA English DT Article ID RELATIVISTIC NUCLEAR COLLISIONS; BOSE-EINSTEIN CORRELATION; TWISS CORRELATION RADII; QUARK-GLUON PLASMA; 2-PARTICLE CORRELATIONS; 2-PION CORRELATIONS; SOURCE PARAMETERS; INTERFEROMETRY; AGS AB Two-pion correlation functions are analyzed at midrapidity for three systems (14.6A GeV/c Si+Al, Si+Au, and 11.6A GeV/c Au+Au), seven distinct centrality conditions, and different k(T) bins in the range 0.1-0.5 GeV/c. Source reference frames are determined from fits to the Yano-Koonin source parametrization. Bertsch-Pratt radius parameters are shown to scale linearly with both number of projectile and total participants as obtained from a Glauber model calculation. A finite lifetime parameter that increases linearly with system/centrality is also reported. The m(T) dependences of the Bertsch-Pratt radii for the central Si+Au and central Au+Au systems differ only by an overall normalization factor given by the measured system/centrality dependence. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Columbia Univ, New York, NY 10027 USA. Nevis Labs, Irvington, NY USA. Univ Calif Riverside, Riverside, CA 92507 USA. High Energy Accelerator Res Org KEK, Tanashi Branch, Tokyo 188, Japan. Kyushu Univ, Fukuoka 812, Japan. Kyoto Univ, Sakyo Ku, Kyoto 606, Japan. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Maryland, College Pk, MD 20742 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. NYU, New York, NY 10003 USA. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Univ Tokyo, Sch Sci, Ctr Nucl Study, Tokyo 188, Japan. RP Ahle, L (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Mignerey, Alice/D-6623-2011; seto, richard/G-8467-2011; Cumming, James/I-3358-2013; SAKURAI, HIROYOSHI/G-5085-2014; Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014 OI Cumming, James/0000-0001-6930-0958; Hayano, Ryugo/0000-0002-1214-7806; NR 46 TC 34 Z9 35 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD NOV PY 2002 VL 66 IS 5 AR 054906 DI 10.1103/PhysRevC.66.054906 PG 15 WC Physics, Nuclear SC Physics GA 624LB UT WOS:000179760200041 ER PT J AU Back, BB Betts, RR Chang, J Chang, WC Chi, CY Chu, YY Cumming, JB Dunlop, JC Eldredge, W Fung, SY Ganz, R Garcia, E Gillitzer, A Heintzelman, G Henning, WF Hofman, DJ Holzman, B Kang, JH Kim, EJ Kim, SY Kwon, Y McLeod, D Mignerey, AC Moulson, M Nanal, V Ogilvie, CA Pak, R Ruangma, A Russ, DE Seto, RK Stanskas, PJ Stephans, GSF Wang, HQ Wolfs, FLH Wuosmaa, AH Xiang, H Xu, GH Yao, HB Zou, CM AF Back, BB Betts, RR Chang, J Chang, WC Chi, CY Chu, YY Cumming, JB Dunlop, JC Eldredge, W Fung, SY Ganz, R Garcia, E Gillitzer, A Heintzelman, G Henning, WF Hofman, DJ Holzman, B Kang, JH Kim, EJ Kim, SY Kwon, Y McLeod, D Mignerey, AC Moulson, M Nanal, V Ogilvie, CA Pak, R Ruangma, A Russ, DE Seto, RK Stanskas, PJ Stephans, GSF Wang, HQ Wolfs, FLH Wuosmaa, AH Xiang, H Xu, GH Yao, HB Zou, CM TI Proton emission in Au+Au collisions at 6, 8, and 10.8 GeV/nucleon SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION EXPERIMENTS; BARYON RAPIDITY LOSS; 11.6A GEV/C; MULTIPLICITY AB Transverse mass spectra of protons emitted in Au+Au collisions at beam energies of 6, 8, and 10.8 GeV/nucleon have been measured as a function of collision centrality over a rapidity range 0.52(+)) strengths, and g factors for the lowest 2(+) states near Sn-132 (Zgreater than or equal to50). We trace the anomalous behavior in the Te isotopes to a reduced neutron pairing above the N=82 magic gap. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, BU-1784 Sofia, Bulgaria. RP Terasaki, J (reprint author), Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. NR 32 TC 107 Z9 108 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 NOV PY 2002 VL 66 IS 5 AR 054313 DI 10.1103/PhysRevC.66.054313 PG 8 WC Physics, Nuclear SC Physics GA 624LB UT WOS:000179760200028 ER PT J AU Acosta, D Affolder, T Akimoto, H Albrow, MG Ambrose, D Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Artikov, A Asakawa, T Ashmanskas, W Azfar, F Azzi-Bacchetta, P Bacchetta, N Bachacou, H Badgett, W Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Behari, S Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berryhill, J Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bolla, G Bolshov, A Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A Bromberg, C Brozovic, M Brubaker, E Bruner, N Budagov, J Budd, HS Burkett, K Busetto, G Byrum, KL Cabrera, S Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W Castro, A Cauz, D Cerri, A Cerrito, L Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, JY Chung, WH Chung, YS Ciobanu, CI Clark, AG Coca, M Colijn, AP Connolly, A Convery, M Conway, J Cordelli, M Cranshaw, J Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demers, S Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Dominguez, A Donati, S D'Onofrio, M Dorigo, T Dunietz, I Eddy, N Einsweiler, K Engels, E Erbacher, R Errede, D Errede, S Fan, Q Fang, HC Farrington, S Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Flores-Castillo, LR Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallas, A Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Gerstein, E Giannetti, P Giolo, K Giordani, M Giromini, P Glagolev, V Glenzinski, D Gold, M Goldstein, J Gomez, G Goncharov, M Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Gresele, A Grim, G Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM Haber, C Hahn, SR Halkiadakis, E Hall, C Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Hennecke, M Herndon, M Hill, C Hocker, A Hoffman, KD Hollebeek, R Holloway, L Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Ivanov, A Iwai, J Iwata, Y Iyutin, B James, E Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Unel, MK Karr, K Kartal, S Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SB Kim, SH Kim, TH Kim, YK Kirby, M Kirk, M Kirsch, L Klimenko, S Koehn, P Kondo, K Konigsberg, J Korn, A Korytov, A Kotelnikov, K Kovacs, E Kroll, J Kruse, M Krutelyov, V Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lancaster, J Lannon, K Lancaster, M Lander, R Lath, A Latino, G LeCompte, T Le, Y Lee, K Lee, SW Leonardo, N Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, T Liu, YC Litvintsev, DO Lobban, O Lockyer, NS Loginov, A Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Manca, G Mariotti, M Martignon, G Martin, M Martin, A Martin, V Matthews, JAJ Mazzanti, P McFarland, KS McIntyre, P Menguzzato, M Menzione, A Merkel, P Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Miyazaki, Y Moggi, N Moore, E Moore, R Morita, Y Moulik, T Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nagaslaev, V Nahn, S Nakada, H Nakano, I Napora, R Nelson, C Nelson, T Neu, C Neubauer, MS Neuberger, D Newman-Holmes, C Ngan, CYP Nigmanov, T Niu, H Nodulman, L Nomerotski, A Oh, SH Oh, YD Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Partos, D Patrick, J Pauletta, G Paulini, M Pauly, T Paus, C Pellett, D Penzo, A Pescara, L Phillips, TJ Piacentino, G Piedra, J Pitts, KT Pompos, A Pondrom, L Pope, G Pratt, T Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Rademacker, J Rakitine, A Ratnikov, F Reher, D Reichold, A Renton, P Ribon, A Riegler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Rott, C Roy, A Ruiz, A Ryan, D Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C Sansoni, A Santi, L Sato, H Savard, P Savoy-Navarro, A Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Sedov, A Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Sidoti, A Siegrist, J Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Snider, FD Snihur, R Solodsky, A Spalding, J Speer, T Spezziga, M Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sukhanov, A Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Tecchio, M Tesarek, RJ Teng, PK Terashi, K Tether, S Thompson, AS Thomson, E Thurman-Keup, R Tipton, P Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonelli, D Tonnesmann, M Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Tsybychev, D Turini, N Ukegawa, F Unverhau, T Vaiciulis, T Valls, J Vataga, E Vejcik, S Velev, G Veramendi, G Vidal, R Vila, I Vilar, R Volobouev, I von der Mey, M Vucinic, D Wagner, RG Wagner, RL Wagner, W Wallace, NB Wan, Z Wang, C Wang, MJ Wang, SM Ward, B Waschke, S Watanabe, T Waters, D Watts, T Weber, M Wenzel, H Wester, WC Whitehouse, B Wicklund, AB Wicklund, E Wilkes, T Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Wolter, M Worm, S Wu, X Wurthwein, F Wyss, J Yang, UK Yao, W Yeh, GP Yeh, P Yi, K Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Yun, JC Zanetti, A Zetti, F Zucchelli, S AF Acosta, D Affolder, T Akimoto, H Albrow, MG Ambrose, D Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Artikov, A Asakawa, T Ashmanskas, W Azfar, F Azzi-Bacchetta, P Bacchetta, N Bachacou, H Badgett, W Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Behari, S Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berryhill, J Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bolla, G Bolshov, A Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A Bromberg, C Brozovic, M Brubaker, E Bruner, N Budagov, J Budd, HS Burkett, K Busetto, G Byrum, KL Cabrera, S Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W Castro, A Cauz, D Cerri, A Cerrito, L Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, JY Chung, WH Chung, YS Ciobanu, CI Clark, AG Coca, M Colijn, AP Connolly, A Convery, M Conway, J Cordelli, M Cranshaw, J Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demers, S Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Dominguez, A Donati, S D'Onofrio, M Dorigo, T Dunietz, I Eddy, N Einsweiler, K Engels, E Erbacher, R Errede, D Errede, S Fan, Q Fang, HC Farrington, S Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Flores-Castillo, LR Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallas, A Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Gerstein, E Giannetti, P Giolo, K Giordani, M Giromini, P Glagolev, V Glenzinski, D Gold, M Goldstein, J Gomez, G Goncharov, M Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Gresele, A Grim, G Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM Haber, C Hahn, SR Halkiadakis, E Hall, C Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Hennecke, M Herndon, M Hill, C Hocker, A Hoffman, KD Hollebeek, R Holloway, L Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Ivanov, A Iwai, J Iwata, Y Iyutin, B James, E Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Unel, MK Karr, K Kartal, S Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SB Kim, SH Kim, TH Kim, YK Kirby, M Kirk, M Kirsch, L Klimenko, S Koehn, P Kondo, K Konigsberg, J Korn, A Korytov, A Kotelnikov, K Kovacs, E Kroll, J Kruse, M Krutelyov, V Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lancaster, J Lannon, K Lancaster, M Lander, R Lath, A Latino, G LeCompte, T Le, Y Lee, K Lee, SW Leonardo, N Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, T Liu, YC Litvintsev, DO Lobban, O Lockyer, NS Loginov, A Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Manca, G Mariotti, M Martignon, G Martin, M Martin, A Martin, V Matthews, JAJ Mazzanti, P McFarland, KS McIntyre, P Menguzzato, M Menzione, A Merkel, P Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Miyazaki, Y Moggi, N Moore, E Moore, R Morita, Y Moulik, T Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nagaslaev, V Nahn, S Nakada, H Nakano, I Napora, R Nelson, C Nelson, T Neu, C Neubauer, MS Neuberger, D Newman-Holmes, C Ngan, CYP Nigmanov, T Niu, H Nodulman, L Nomerotski, A Oh, SH Oh, YD Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Partos, D Patrick, J Pauletta, G Paulini, M Pauly, T Paus, C Pellett, D Penzo, A Pescara, L Phillips, TJ Piacentino, G Piedra, J Pitts, KT Pompos, A Pondrom, L Pope, G Pratt, T Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Rademacker, J Rakitine, A Ratnikov, F Reher, D Reichold, A Renton, P Ribon, A Riegler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Rott, C Roy, A Ruiz, A Ryan, D Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C Sansoni, A Santi, L Sato, H Savard, P Savoy-Navarro, A Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Sedov, A Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Sidoti, A Siegrist, J Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Snider, FD Snihur, R Solodsky, A Spalding, J Speer, T Spezziga, M Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sukhanov, A Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Tecchio, M Tesarek, RJ Teng, PK Terashi, K Tether, S Thompson, AS Thomson, E Thurman-Keup, R Tipton, P Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonelli, D Tonnesmann, M Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Tsybychev, D Turini, N Ukegawa, F Unverhau, T Vaiciulis, T Valls, J Vataga, E Vejcik, S Velev, G Veramendi, G Vidal, R Vila, I Vilar, R Volobouev, I von der Mey, M Vucinic, D Wagner, RG Wagner, RL Wagner, W Wallace, NB Wan, Z Wang, C Wang, MJ Wang, SM Ward, B Waschke, S Watanabe, T Waters, D Watts, T Weber, M Wenzel, H Wester, WC Whitehouse, B Wicklund, AB Wicklund, E Wilkes, T Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Wolter, M Worm, S Wu, X Wurthwein, F Wyss, J Yang, UK Yao, W Yeh, GP Yeh, P Yi, K Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Yun, JC Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Cross section for forward J/psi production in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW D LA English DT Article ID ROOT S=1.8 TEV; OCTET QUARKONIA PRODUCTION; CDF; MESONS; SYSTEM; DECAYS AB The inclusive cross section for J/psi production times the branching ratio B(J/psi-->mu(+)mu(-)) has been measured in the forward pseudorapidity region: Bxdsigma[(p) over bar +p-->J/psi(p(T)>10 GeV/c,2.1<\eta\<2.6)+X]/deta=192+/-9(stat)+/-29(syst) pb. The results are based on 74.1+/-5.2 pb(-1) of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher p(T)(J/psi). In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements. C1 Univ Florida, Gainesville, FL 32611 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Waseda Univ, Tokyo 169, Japan. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Penn, Philadelphia, PA 19104 USA. Univ Michigan, Ann Arbor, MI 48109 USA. MIT, Cambridge, MA 02139 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Joint Inst Nucl Res, RU-141980 Dubna, Russia. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Harvard Univ, Cambridge, MA 02138 USA. Univ Rochester, Rochester, NY 14627 USA. Purdue Univ, W Lafayette, IN 47907 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Calif Davis, Davis, CA 95616 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Trieste Udine, Ist Nazl Fis Nucl, Trieste, Italy. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Wisconsin, Madison, WI 53706 USA. Duke Univ, Durham, NC 27708 USA. Brandeis Univ, Waltham, MA 02254 USA. Rockefeller Univ, New York, NY 10021 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Univ Illinois, Urbana, IL 61801 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Geneva, CH-1211 Geneva 4, Switzerland. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Yale Univ, New Haven, CT 06520 USA. High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 305, Japan. Northwestern Univ, Evanston, IL 60208 USA. Carnegie Mellon Univ, Pittsburgh, PA 15218 USA. Univ Cantabria, CSIC, Inst Fis Cantabria, E-39005 Santander, Spain. Texas A&M Univ, College Stn, TX 77843 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Tufts Univ, Medford, MA 02155 USA. Osaka City Univ, Osaka 588, Japan. Kyungpook Natl Univ, Ctr High Energy Phys, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Suwon 440746, South Korea. Inst Theoret & Expt Phys, Moscow 117259, Russia. UCL, London WC1E 6BT, England. Univ Toronto, Inst Particle Phys, Toronto, ON M5S 1A7, Canada. RP Univ Florida, Gainesville, FL 32611 USA. RI Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; Cabrera Urban, Susana/H-1376-2015; Introzzi, Gianluca/K-2497-2015; Gorelov, Igor/J-9010-2015; Prokoshin, Fedor/E-2795-2012; Leonardo, Nuno/M-6940-2016; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Ruiz, Alberto/E-4473-2011; Wolter, Marcin/A-7412-2012; St.Denis, Richard/C-8997-2012; Azzi, Patrizia/H-5404-2012; manca, giulia/I-9264-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Ivanov, Andrew/A-7982-2013; Kim, Soo-Bong/B-7061-2014; Gallas Torreira, Abraham Antonio/K-6508-2014 OI Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; Gorelov, Igor/0000-0001-5570-0133; Prokoshin, Fedor/0000-0001-6389-5399; Leonardo, Nuno/0000-0002-9746-4594; Ruiz, Alberto/0000-0002-3639-0368; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Ivanov, Andrew/0000-0002-9270-5643; Gallas Torreira, Abraham Antonio/0000-0002-2745-7954 NR 21 TC 1 Z9 1 U1 1 U2 6 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 NOV 1 PY 2002 VL 66 IS 9 AR 092001 DI 10.1103/PhysRevD.66.092001 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400004 ER PT J AU Arbuzov, A Melnikov, K AF Arbuzov, A Melnikov, K TI O(alpha(2)ln(m(mu)/m(e))) corrections to the electron energy spectrum in muon decay SO PHYSICAL REVIEW D LA English DT Article ID PARTON DENSITIES; LEADING ORDER; HEAVY QUARKS; FRAGMENTATION; MODEL; QCD AB The O(alpha(2)ln(m(mu)/m(e))) corrections to the electron energy spectrum in muon decay are computed using the perturbative fragmentation function approach. The magnitude of these corrections is comparable to the anticipated precision of the TWIST experiment where the Michel parameters will be extracted from the measurement of the electron energy spectrum in muon decay. C1 Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Arbuzov, A (reprint author), Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. RI Arbuzov, Andrej/J-6073-2013 OI Arbuzov, Andrej/0000-0001-9326-6905 NR 24 TC 31 Z9 31 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 NOV 1 PY 2002 VL 66 IS 9 AR 093003 DI 10.1103/PhysRevD.66.093003 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400008 ER PT J AU Atwood, D Bar-Shalom, S Eilam, G Soni, A AF Atwood, D Bar-Shalom, S Eilam, G Soni, A TI Flavor changing Zeta decays from scalar interactions at a giga-Zeta linear collider SO PHYSICAL REVIEW D LA English DT Article ID R-PARITY VIOLATION; RADIATIVE B-DECAYS; 2-HIGGS DOUBLET MODEL; STANDARD MODEL; TOP-QUARK; QCD CORRECTIONS; CP VIOLATION; NEUTRINO OSCILLATIONS; HIGGS-BOSON; Z0 DECAYS AB The flavor changing decay Z-->d(I)(d) over bar (J) is investigated with special emphasis on the b (s) over bar final state. Various models for flavor violation are considered: two Higgs doublet models (2HDM's), supersymmetry (SUSY) with flavor violation in the up- and down-type squark mass matrices and SUSY with flavor violation mediated by R-parity-violating interaction. We find that, within the SUSY scenarios for flavor violation, the branching ratio for the decay Z-->b (s) over bar can reach 10(-6) for large tan beta values, while the typical size for this branching ratio in the 2HDM's considered is about two orders of magnitude smaller at best. Thus, flavor changing SUSY signatures in radiative Z decays such as Z-->b (s) over bar may be accessible to future "Z factories" such as a giga-Z version of the DESY TESLA design. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RAFAEL, Theoret Phys Grp, IL-31021 Haifa, Israel. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Brookhaven Natl Lab, Theory Grp, Upton, NY 11973 USA. RP Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM atwood@iastate.edu; shaouly@physics.technion.ac.il; eilam@physics.technion.ac.il; soni@bnl.gov NR 79 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 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 2002 VL 66 IS 9 AR 093005 DI 10.1103/PhysRevD.66.093005 PG 23 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400010 ER PT J AU Berger, EL Chiang, CW Jiang, J Tait, TMP Wagner, CEM AF Berger, EL Chiang, CW Jiang, J Tait, TMP Wagner, CEM TI Higgs boson decay into hadronic jets SO PHYSICAL REVIEW D LA English DT Review ID SUPERSYMMETRIC STANDARD MODEL; GAMMA-GAMMA COLLISIONS; ELECTROWEAK SYMMETRY-BREAKING; HEAVY-QUARK PRODUCTION; TO-LEADING ORDER; SUPERCONDUCTING SUPER COLLIDER; LARGE TRANSVERSE-MOMENTUM; EFFECTIVE-FIELD-THEORY; SCALAR BOTTOM QUARK; QCD CORRECTIONS AB The remarkable agreement of electroweak data with standard model (SM) predictions motivates the study of extensions of the SM in which the Higgs boson is light and couples in a standard way to the weak gauge bosons. Postulated new light particles should have small couplings to the gauge bosons. Within this context it is natural to assume that the branching fractions of the light SM-like Higgs boson mimic those in the standard model. This assumption may be unwarranted, however, if there are nonstandard light particles coupled weakly to the gauge bosons but strongly to the Higgs field. In particular, the Higgs boson may effectively decay into hadronic jets, possibly without important bottom or charm flavor content. As an example, we present a simple extension of the SM, in which the predominant decay of the Higgs boson occurs into a pair of light bottom squarks that, in turn, manifest themselves as hadronic jets. Discovery of the Higgs boson remains possible at an electron-positron linear collider, but prospects at hadron colliders are diminished substantially. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. RP Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. EM berger@anl.gov; chengwei@hep.uchicago.edu; jiangj@hep.anl.gov; tait@anl.gov; cwagner@hep.anl.gov OI Chiang, Cheng-Wei/0000-0003-1716-0169 NR 123 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 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 2002 VL 66 IS 9 AR 095001 DI 10.1103/PhysRevD.66.095001 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400049 ER PT J AU Bodwin, GT Petrelli, A AF Bodwin, GT Petrelli, A TI Order-v(4) corrections to S-wave quarkonium decay SO PHYSICAL REVIEW D LA English DT Article ID LEPTONIC DECAYS; MATRIX-ELEMENTS; ANNIHILATION; QCD; MESON AB We compute corrections of relative order v(4) to the rates for the decays of S-1(0) heavy quarkonium into two photons and into light hadrons and for the decays of S-3(1) heavy quarkonium into a lepton pair and into light hadrons. In particular, we compute the coefficients of the decay operators that have the same quantum numbers as the heavy quarkonium. We also confirm previous calculations of the order-v(2) corrections to these rates. We find that the v expansion converges well for the decays of S-1(0) heavy quarkonium and for the decay of S-3(1) heavy quarkonium into a lepton pair. Large higher-order-in-v corrections appear in the decay of S-3(1) heavy quarkonium into light hadrons. However, we find that the series of coefficients of operators with S-3(1) quantum numbers, which yields a large correction in order v(2), yields a smaller correction in order v(4). C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Bodwin, GT (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. NR 22 TC 100 Z9 100 U1 0 U2 3 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 NOV 1 PY 2002 VL 66 IS 9 AR 094011 DI 10.1103/PhysRevD.66.094011 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400028 ER PT J AU Chacko, Z Katz, E Perazzi, E AF Chacko, Z Katz, E Perazzi, E TI Yukawa deflected gauge mediation in four dimensions SO PHYSICAL REVIEW D LA English DT Article ID DYNAMICAL SUPERSYMMETRY BREAKING; (DE)CONSTRUCTING DIMENSIONS AB We construct a four dimensional realization of a higher dimensional model, Yukawa deflected gauge mediation, in which supersymmetry breaking is communicated to the visible sector through both gauge and Yukawa interactions. The reduction to four dimensions is achieved by "deconstructing" or "latticizing" the extra dimension. Three sites (gauge groups) are sufficient to reproduce the spectrum of the higher dimensional model. The characteristic features of Yukawa deflected gauge mediation, in particular, alignment of squarks and quarks, and a natural solution to the mu problem, carry over to the deconstructed version of the model. We comment on the implications of our results for a solution of the mu problem in the context of deconstructed gaugino mediation. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM zchacko@thsrv.lbl.gov; amikatz@phys.washington.edu; EPerazzi@lbl.gov NR 34 TC 20 Z9 20 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD NOV 1 PY 2002 VL 66 IS 9 AR 095012 DI 10.1103/PhysRevD.66.095012 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400060 ER PT J AU Chamblin, A Nayak, GC AF Chamblin, A Nayak, GC TI Black hole production at the CERN LHC: String balls and black holes from pp and lead-lead collisions SO PHYSICAL REVIEW D LA English DT Article ID ULTRARELATIVISTIC NUCLEAR COLLISIONS; GLUON DISTRIBUTION-FUNCTIONS; PARTON DISTRIBUTIONS; MINIJET PLASMA; ENERGY; EQUILIBRATION; BRANE; DIMENSIONS; MILLIMETER; HIERARCHY AB If the fundamental Planck scale is near a TeV, then parton collisions with high enough center-of-mass energy should produce black holes. The production rate for such black holes at the CERN LHC has been extensively studied for the case of a proton-proton collision. In this paper, we extend this analysis to a lead-lead collision at LHC. We find that the cross section for small black holes which may in principle be produced in such a collision is either enhanced or suppressed, depending upon the black hole mass. For example, for black holes with a mass around 3 TeV we find that the differential black hole production cross section, dsigma/dM, in a typical lead-lead collision is up to 90 times larger than that for black holes produced in a typical proton-proton collision. We also discuss the cross sections for "string ball" production in these collisions. For string balls of mass about 1 (2) TeV, we find that the differential production cross section in a typical lead-lead collision may be enhanced by a factor up to 3300 (850) times that of a proton-proton collision at LHC. C1 Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. Univ London, Queen Mary, Dept Phys, London E1 4NS, England. RP Los Alamos Natl Lab, Div Theory, T-8, Los Alamos, NM 87545 USA. NR 50 TC 64 Z9 64 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 NOV 1 PY 2002 VL 66 IS 9 AR 091901 DI 10.1103/PhysRevD.66.091901 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400003 ER PT J AU Dumitru, A Pisarski, RD AF Dumitru, A Pisarski, RD TI Two-point functions for SU(3) Polyakov loops near T-c SO PHYSICAL REVIEW D LA English DT Article ID DECONFINING PHASE-TRANSITION; LATTICE GAUGE-THEORY; DIMENSIONAL REDUCTION; FINITE-TEMPERATURE; SCREENING MASSES; GLUON PLASMA; QCD; WILSON; THERMODYNAMICS; CONDENSATE AB We discuss the behavior of two point functions for Polyakov loops in an SU(3) gauge theory about the critical temperature T-c. From a Z(3) model, in mean field theory we obtain a prediction for the ratio of masses at T-c, extracted from correlation functions for the imaginary and real parts of the Polyakov loop. This ratio is m(i)/m(r)=3 if the potential only includes terms up to quartic order in the Polyakov loop; its value changes as pentic and hexatic interactions become important. The Polyakov loop model then predicts how m(i)/m(r) changes above T-c. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM dumitru@quark.phy.bnl.gov; pisarski@quark.phy.bnl.gov NR 37 TC 77 Z9 78 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 NOV 1 PY 2002 VL 66 IS 9 AR 096003 DI 10.1103/PhysRevD.66.096003 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400067 ER PT J AU Gelis, F Jalilian-Marian, J AF Gelis, F Jalilian-Marian, J TI Dilepton production from the color glass condensate SO PHYSICAL REVIEW D LA English DT Article ID WILSON RENORMALIZATION-GROUP; GLUON DISTRIBUTION-FUNCTIONS; WEIZSACKER-WILLIAMS FIELDS; NUCLEUS-NUCLEUS COLLISIONS; HIGH-DENSITY QCD; LOW X PHYSICS; PARTON DISTRIBUTIONS; TRANSVERSE-MOMENTUM; CHARGE-DENSITY; EVOLUTION AB We consider dilepton production in high energy proton-nucleus (and very forward nucleus-nucleus) collisions. Treating the target nucleus as a color glass condensate and describing the projectile proton (nucleus) as a collection of quarks and gluons as in the parton model, we calculate the differential cross section for dilepton production in quark-nucleus scattering and show that it is very sensitive to the saturation scale characterizing the target nucleus. C1 Univ Paris 11, Phys Theor Lab, F-91405 Orsay, France. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Gelis, F (reprint author), Univ Paris 11, Phys Theor Lab, Batiment 210, F-91405 Orsay, France. NR 47 TC 60 Z9 60 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 NOV 1 PY 2002 VL 66 IS 9 AR 094014 DI 10.1103/PhysRevD.66.094014 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400031 ER PT J AU Kiers, K Kolb, J Lee, J Soni, A Wu, GH AF Kiers, K Kolb, J Lee, J Soni, A Wu, GH TI Ubiquitous CP violation in a top-inspired left-right model SO PHYSICAL REVIEW D LA English DT Article ID RIGHT-SYMMETRIC MODELS; KS MASS DIFFERENCE; GAUGE-THEORIES; MESON SYSTEM; DECAYS; CONSTRAINTS; PARITY; SCALE AB We explore CP violation in a left-right-model that reproduces the quark mass and CKM rotation angle hierarchies in a relatively natural way by fixing the bidoublet Higgs VEVs to be in the ratio m(b):m(t). Our model is quite general and allows for CP to be broken by both the Higgs VEVs and the Yukawa couplings. Despite this generality, CP violation may be parametrized in terms of two basic phases. A very interesting feature of the model is that the mixing angles in the right-handed sector are found to be equal to their left-handed counterparts to a very good approximation. Furthermore, the right-handed analogue of the usual CKM phase delta(L) is found to satisfy the relation delta(R)approximate todelta(L). The parameter space of the model is explored by using an adaptive Monte Carlo algorithm and the allowed regions in parameter space are determined by enforcing experimental constraints from the K and B systems. This method of solution allows us to evaluate the left-and right-handed CKM matrices numerically for various combinations of the two fundamental CP-odd phases in the model. We find that all experimental constraints may be satisfied with right-handed W and flavor changing neutral Higgs boson masses as low as about 2 TeV and 7 TeV, respectively. C1 Taylor Univ, Dept Phys, Upland, IN 46989 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. RP Kiers, K (reprint author), Taylor Univ, Dept Phys, 236 W Reade Ave, Upland, IN 46989 USA. NR 43 TC 30 Z9 30 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 NOV 1 PY 2002 VL 66 IS 9 AR 095002 DI 10.1103/PhysRevD.66.095002 PG 23 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400050 ER PT J AU Martin, SP AF Martin, SP TI Two-loop effective potential for the minimal supersymmetric standard model SO PHYSICAL REVIEW D LA English DT Article ID HIGGS-BOSON MASS; DIFFERENTIAL-EQUATIONS METHOD; SELF-ENERGY DIAGRAMS; RENORMALIZATION-GROUP IMPROVEMENT; RADIATIVE-CORRECTIONS; DIMENSIONAL REDUCTION; MOMENTUM EXPANSION; PHI(4) THEORY; BREAKING; MSSM AB I compute the complete two-loop effective potential for the minimal supersymmetric standard model in the Landau gauge. This enables an accurate determination of the minimization conditions for the vacuum expectation values of the Higgs fields. Checks on the result follow from supersymmetric limits and from renormalization-scale invariance. The renormalization group equations for the field-independent vacuum energy and the vacuum expectation values are also presented. I provide numerical examples showing the improved accuracy and scale dependence obtained with the full two-loop effective potential. C1 No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Martin, SP (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. NR 63 TC 90 Z9 90 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 NOV 1 PY 2002 VL 66 IS 9 AR 096001 DI 10.1103/PhysRevD.66.096001 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400065 ER PT J AU Minakata, H Nunokawa, H Parke, S AF Minakata, H Nunokawa, H Parke, S TI Parameter degeneracies in neutrino oscillation measurement of leptonic CP and T violation SO PHYSICAL REVIEW D LA English DT Article ID BASE-LINE EXPERIMENTS; MATTER; KAMLAND; B-8 AB The measurement of the mixing angle theta(13), sign of Deltam(13)(2), and the CP or T violating phase delta is fraught with ambiguities in neutrino oscillation. In this paper we give an analytic treatment of the paramater degeneracies associated with measuring the nu(mu)-->nu(e) probability and its CP and/or T conjugates. For CP violation, we give explicit solutions to allow us to obtain the regions where there exist twofold and fourfold degeneracies. We calculate the fractional differences, (Deltatheta/(theta) over bar), between the allowed solutions which may be used to compare with the expected sensitivities of the experiments. For T violation we show that there is always a complete degeneracy between solutions with positive and negative Deltam(13)(2) which arises due to a symmetry and cannot be removed by observing one neutrino oscillation probability and its T conjugate. Thus there is always a fourfold parameter degeneracy apart from exceptional points. Explicit solutions are also given and the fractional differences are computed. The biprobability CP/T trajectory diagrams are extensively used to illuminate the nature of the degeneracies. C1 Tokyo Metropolitan Univ, Dept Phys, Tokyo 1920397, Japan. Univ Estadual Paulista, Inst Fis Teor, BR-01405900 Sao Paulo, Brazil. Fermilab Natl Accelerator Lab, Dept Phys Theor, Batavia, IL 60510 USA. RP Tokyo Metropolitan Univ, Dept Phys, 1-1 Minami Osawa, Tokyo 1920397, Japan. EM minakata@phys.metro-u.ac.jp; nunokawa@ift.unesp.br; parke@fnal.gov OI Parke, Stephen/0000-0003-2028-6782 NR 66 TC 86 Z9 86 U1 0 U2 5 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 NOV 1 PY 2002 VL 66 IS 9 AR 093012 DI 10.1103/PhysRevD.66.093012 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 622ZY UT WOS:000179679400017 ER PT J AU Balsara, NP Marques, CM Garetz, BA Newstein, MC Gido, SP AF Balsara, NP Marques, CM Garetz, BA Newstein, MC Gido, SP TI Anisotropy of lamellar block copolymer grains SO PHYSICAL REVIEW E LA English DT Article ID MICROPHASE SEPARATION; GROWTH; MELT; MICRODOMAINS; NUCLEATION AB The Wulff construction and the theory of Milner and Morse [Phys. Rev. E 54, 3793 (1996)] were used to calculate the shape of grains formed when a lamellar block copolymer phase is formed by a shallow quench into the ordered state. The calculations show that the grains are ellipsoids of revolution, with an aspect ratio rho=2.37. This value is in reasonable agreement with results of transmission electron microscopy and depolarized light scattering experiments, which indicate that the average value of rho of grains formed during the early stages of the disorder-to-order transition is about 2.0. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Inst Phys, F-67084 Strasbourg, France. Polytech Univ, Dept Chem & Chem Engn, Brooklyn, NY 11201 USA. Polytech Univ, Dept Elect Engn, Brooklyn, NY 11201 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. RP Balsara, NP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem Engn, Berkeley, CA 94720 USA. RI Marques, Carlos/B-2322-2010 OI Marques, Carlos/0000-0002-3952-0498 NR 21 TC 17 Z9 17 U1 0 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 052802 DI 10.1103/PhysRevE.66.052802 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800087 PM 12513539 ER PT J AU Berman, GP Borgonovi, F Celardo, G Izrailev, FM Kamenev, DI AF Berman, GP Borgonovi, F Celardo, G Izrailev, FM Kamenev, DI TI Dynamical fidelity of a solid-state quantum computation SO PHYSICAL REVIEW E LA English DT Article ID CHAOS; SYSTEMS; COMPUTER; DECOHERENCE; BORDER; MODEL AB In this paper we analyze the dynamics in a spin model of quantum computer. Main attention is paid to the dynamical fidelity (associated with dynamical errors) of an algorithm that allows to create an entangled state for remote qubits. We show that in the regime of selective resonant excitations of qubits there is no danger of quantum chaos. Moreover, in this regime a modified perturbation theory gives an adequate description of the dynamics of the system. Our approach allows us to explicitly describe all peculiarities of the evolution of the system under time-dependent pulses corresponding to a quantum protocol. Specifically, we analyze, both analytically and numerically, how the fidelity decreases in dependence on the model parameters. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Univ Cattolica, Dipartimento Matemat & Fis, I-25121 Brescia, Italy. Ist Nazl Fis Nucl, Sez Pavia, Pavia, Italy. Ist Nazl Fis Nucl, Unita Brescia, Brescia, Italy. INFM, Unita Milano, Milan, Italy. Univ Autonoma Puebla, Inst Fis, Puebla 72570, Mexico. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI celardo, giuseppe/J-3629-2015; OI celardo, giuseppe/0000-0002-3679-1954; borgonovi, fausto/0000-0002-9730-1189 NR 25 TC 14 Z9 14 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 056206 DI 10.1103/PhysRevE.66.056206 PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800133 PM 12513585 ER PT J AU Christodoulou, A Lampiris, D Polykandriotis, K Colson, WB Crooker, PP Benson, S Gubeli, J Neil, GR AF Christodoulou, A Lampiris, D Polykandriotis, K Colson, WB Crooker, PP Benson, S Gubeli, J Neil, GR TI Free-electron-laser oscillator with a linear taper SO PHYSICAL REVIEW E LA English DT Article ID FEL OSCILLATOR; UNDULATOR; FEATURES AB We present experiments and simulations showing the behavior of a free-electron laser (FEL) with both positive and negative linear tapers along the wiggler. We show the power desynchronism curve widths, efficiency, exhaust electron energy spread, and wavelength dependence as a function of taper for 3- and 6-mum optical wavelengths and for resonators with 10% and 2% loss/pass. Simulations of the experiments, using a multimode analysis, are seen to be in general agreement with the experimental results, carried out at the IR Demo FEL at Thomas Jefferson National Accelerator Facility. We find that short-pulse effects are more effective than tapers in producing high efficiency with low exhaust energy spread, and the expected performance enhancement of FEL tapering is not achieved. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Christodoulou, A (reprint author), USN, Postgrad Sch, Monterey, CA 93943 USA. NR 14 TC 5 Z9 5 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 056502 DI 10.1103/PhysRevE.66.056502 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800162 PM 12513614 ER PT J AU Kang, QJ Zhang, DX Chen, SY AF Kang, QJ Zhang, DX Chen, SY TI Unified lattice Boltzmann method for flow in multiscale porous media SO PHYSICAL REVIEW E LA English DT Article ID 3-DIMENSIONAL NETWORKS; CIRCULAR-CYLINDER; CONTINUUM MODELS; CURVED BOUNDARY; LENGTH SCALES; FLUID-FLOW; EQUATION; PERMEABILITY; SIMULATION; DERIVATION AB In this paper, we develop a unified lattice Boltzmann method for flow in multiscale porous media. This model not only can simulate flow in porous systems of various length scales but also can simulate flow in porous systems where multiple length scales coexist. Simulations of unidirectional steady flow through homogeneous and heterogeneous porous media both recover Darcy's law when the effects of inertial forces and Brinkman correction may be negligible. Direct use of this model on the usual computational nodes, with zero resistance on void spaces and infinite resistance on solid walls, gives results that agree well with analytical solutions. Simulations performed on a fractured porous system show that the method presented here gives very good overall permeability values for the whole fractured system. A series of simulations is performed on a simplified fractured system. The results indicate that, when the ratio of the permeability of the rock matrix to the fracture permeability calculated by the cubic law is less than 10(-4), the effects of the rock matrix flow are negligible, and the discrete-fracture models that ignore such flow are plausible. When the ratio is larger than 10(-4), the matrix flow has significant effects on the fractured system, and the assumption that the matrix is impermeable does not hold. Therefore, the use of the cubic law to calculate the fracture permeability may cause a significant error. It is also indicated that the larger the ratio of the width of the porous matrix to that of the fracture, the more significant is the error caused by using the cubic law. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Peking Univ, Beijing 100871, Peoples R China. RP Kang, QJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Zhang, Dongxiao/D-5289-2009; Chen, Shiyi/A-3234-2010 OI Zhang, Dongxiao/0000-0001-6930-5994; NR 53 TC 83 Z9 84 U1 2 U2 30 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 056307 DI 10.1103/PhysRevE.66.056307 PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800144 PM 12513596 ER PT J AU Rai, BK Durbin, SM Prohofsky, EW Sage, JT Ellison, MK Scheidt, WR Sturhahn, W Alp, EE AF Rai, BK Durbin, SM Prohofsky, EW Sage, JT Ellison, MK Scheidt, WR Sturhahn, W Alp, EE TI Iron normal mode dynamics in a porphyrin-imidazole model for deoxyheme proteins SO PHYSICAL REVIEW E LA English DT Article ID RESONANCE RAMAN-SPECTRA; HISTIDINE STRETCHING MODE; SYNCHROTRON-RADIATION; SCATTERING; MYOGLOBIN; DERIVATIVES; SPECTROSCOPY; VIBRATIONS; HEMOGLOBIN; LINKAGE AB Iron vibrational modes of a deoxyheme protein model (2-methylimidazole)(tetraphenylporphinato)iron(II), [Fe(TPP)(2-MeImH)], have been studied by refining normal mode calculations to nuclear resonance vibrational spectroscopy (NRVS) data. The NRVS measurements give quantitative frequencies and iron amplitudes of all modes with significant Fe vibrational motion. Modes with in-plane displacement of iron are distinguished from those involving out-of-plane motion by measurements on oriented single-crystal samples. Normal modes having large overlaps with in-plane nu(42), nu(50), and nu(53) modes of the porphyrin core are identified, as well as several modes with large iron-imidazole stretch components. An out-of-plane mode at 78 cm(-1) shows significant doming of the porphyrin core, but the largest Fe doming motion arises from the coupling of phenyls and imidazole at 25 cm(-1). C1 Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Univ Notre Dame, Dept Chem & Biochem, Notre Dame, IN 46556 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Rai, BK (reprint author), Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. FU NIGMS NIH HHS [GM-28401, GM-52002] NR 38 TC 24 Z9 24 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 051904 DI 10.1103/PhysRevE.66.051904 PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800068 PM 12513520 ER PT J AU Rosmej, FB Griem, HR Elton, RC Jacobs, VL Cobble, JA Faenov, AY Pikuz, TA Geissel, M Hoffmann, DHH Suss, W Uskov, DB Shevelko, VP Mancini, RC AF Rosmej, FB Griem, HR Elton, RC Jacobs, VL Cobble, JA Faenov, AY Pikuz, TA Geissel, M Hoffmann, DHH Suss, W Uskov, DB Shevelko, VP Mancini, RC TI Charge-exchange-induced two-electron satellite transitions from autoionizing levels in dense plasmas SO PHYSICAL REVIEW E LA English DT Article ID HE-BETA; DIELECTRONIC SATELLITES; CROSS-SECTIONS; IONS; COLLISIONS; SPECTRA; SPECTROSCOPY; POPULATIONS; DIAGNOSTICS; EMISSION AB Order-of-magnitude anomalously high intensities for two-electron (dielectronic) satellite transitions, originating from the He-like 2s(2) (1)S(0) and Li-like 1s2s(2) (2)S(1/2) autoionizing states of silicon, have been observed in dense laser-produced plasmas at different laboratories. Spatially resolved, high-resolution spectra and plasma images show that these effects are correlated with an intense emission of the He-like 1s3p (1)P-1s(2) (1)S lines, as well as the K(alpha) lines. A time-dependent, collisional-radiative model, allowing for non-Maxwellian electron-energy distributions, has been developed for the determination of the relevant nonequilibrium level populations of the silicon ions, and a detailed analysis of the experimental data has been carried out. Taking into account electron density and temperature variations, plasma optical-depth effects, and hot-electron distributions, the spectral simulations are found to be not in agreement with the observations. We propose that highly stripped target ions (e.g., bare nuclei or H-like 1s ground-state ions) are transported into the dense, cold plasma (predominantly consisting of L- and M-shell ions) near the target surface and undergo single- and double-electron charge-transfer processes. The spectral simulations indicate that, in dense and optically thick plasmas, these charge-transfer processes may lead to an enhancement of the intensities of the two-electron transitions by up to a factor of 10 relative to those of the other emission lines, in agreement with the spectral observations. C1 GSI Darmstadt, Plasmaphys, D-64291 Darmstadt, Germany. Univ Maryland, Inst Res Elect & Appl Phys, College Pk, MD 20742 USA. USN, Res Lab, Ctr Computat Mat Sci, Div Mat Sci & Technol, Washington, DC 20375 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Russian Comm Stand, VNIIFRI, Multicharged Ions Spectra Data Ctr, Mendeleyevsk 141570, Moscow Region, Russia. PN Lebedev Phys Inst, Moscow 117924, Russia. Univ Nevada, Dept Phys, Reno, NV 89557 USA. RP Rosmej, FB (reprint author), GSI Darmstadt, Plasmaphys, Planckstr 1, D-64291 Darmstadt, Germany. EM rosmej@yahoo.de RI Hoffmann, Dieter H.H./A-5265-2008; Shevelko, Viacheslav/M-7527-2015 NR 37 TC 29 Z9 29 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 056402 DI 10.1103/PhysRevE.66.056402 PG 16 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800150 PM 12513602 ER PT J AU Zhang, DZ Liu, C Harlow, FH AF Zhang, DZ Liu, C Harlow, FH TI Effects of nonuniform segment deformation on the constitutive relation of polymeric solids SO PHYSICAL REVIEW E LA English DT Article ID GRANULAR FLOWS; RELAXATION; EQUATIONS; NETWORKS; DYNAMICS; LIQUIDS; MODEL; DENSE AB A polymeric solid is modeled as a network of beads and strings. Beads in the polymer are divided into bead groups represented by the segment end points. Based on the equation of motion for each bead in the system, a macroscopic equation of motion for the polymer is derived. Velocity fluctuations of beads result in a pressure, the isotropic component of the stress, in the polymer. Interaction forces transmitted through segments connected to bead groups are the major source of the stress in the polymer. The tendency of segments to achieve their minima in Helmholtz free energy results in thermal elasticity of the polymer. Compared to the time scale of these segment interactions, other interactions among beads groups are short in time, therefore, result in a viscous stress. The motion of an average segment is modeled as an elastic spring immersed in a viscous fluid. The inertia of the segment is neglected because the viscous force is much larger than the inertial force. The governing equation for the deformation of the average segment is found to be a diffusion equation representing the balance between the viscous force and the elastic force in the segment. If the time scale of the macroscopic deformation is short compared to that of the deformation diffusion, the application of forces at both ends results in nonuniform deformation of the segment, which diffuses from the ends toward the center. This diffusion leads to relaxation of the macroscopic stress which we represent by a history integral. The kernel in the integral is asymptotic to 1/roott for a short time t, and is asymptotic to an exponentially decaying function for a long time t, in which t is the elapsed time from initiation of the deformation. This theoretically predicted kernel is observed in experiments conducted at constant temperature. C1 Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp T3, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Struct Property Relat Grp, Los Alamos, NM 87545 USA. RP Zhang, DZ (reprint author), Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp T3, B216, Los Alamos, NM 87545 USA. NR 17 TC 9 Z9 9 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 2002 VL 66 IS 5 AR 051806 DI 10.1103/PhysRevE.66.051806 PG 15 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 622DG UT WOS:000179630800063 PM 12513515 ER PT J AU Channell, PJ AF Channell, PJ TI Phenomenological two-stream instability model in the nonlinear electron regime SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID PROTON INSTABILITY AB We consider the e-p instability for long proton bunches in storage rings. We give a simplified treatment of the centroid model for the linear instability for both unbunched and bunched beams. We point out the very large resulting electron oscillation amplitudes which mean that the electrons very quickly become nonlinear. We then propose a phenomenological theory of the instability in the nonlinear electron regime and show that the resulting model gives a slower growth and different form of the proton oscillations than in the linear theory. We then propose a technique that might eliminate the long term secular growth of the proton oscillations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Channell, PJ (reprint author), Los Alamos Natl Lab, MS-H817, Los Alamos, NM 87545 USA. NR 34 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD NOV PY 2002 VL 5 IS 11 AR 114401 DI 10.1103/PhysRevSTAB.5.114401 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 622CX UT WOS:000179629900004 ER PT J AU Kramer, SL AF Kramer, SL TI Direct observation of beam impedance above cutoff SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID COHERENT SYNCHROTRON-RADIATION; NSLS VUV RING AB Measurements of microwave emission from an electron beam have shown signals below the shielding cutoff frequency of the beam pipe for coherent synchrotron radiation. The frequency spectrum of the signal below this cutoff frequency agrees with calculations and bench measurements of the impedance of a vacuum component in the ring. The wake fields produced in this impedance are above the waveguide cutoff frequency of the beam chamber, allowing the fields to propagate around the ring and out a photon beam port. Data are presented that rule out the possibility that this signal is coherent synchrotron radiation. This unique method of measuring propagating fields is discussed along with its application to measuring high frequency impedances and their impact on beam properties. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Natl Synchrotron Light Source, Bldb 725C, Upton, NY 11973 USA. EM skramer@bnl.gov NR 16 TC 2 Z9 2 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD NOV PY 2002 VL 5 IS 11 AR 112001 DI 10.1103/PhysRevSTAB.5.112001 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 622CX UT WOS:000179629900002 ER PT J AU Pritzkau, DP Siemann, RH AF Pritzkau, DP Siemann, RH TI Experimental study of rf pulsed heating on oxygen free electronic copper SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article AB When the thermal stresses induced by rf pulsed heating are larger than the elastic limit, microcracks and surface roughening will occur due to cyclic fatigue. Therefore, pulsed heating limits the maximum surface magnetic field and through it the maximum achievable accelerating gradient. An experiment using circularly cylindrical cavities operating in the TE011 mode at a resonant frequency of 11.424 GHz was designed to study pulsed heating on oxygen free electronic (OFE) copper. An X-band klystron delivered up to 10 MW to the cavities in 1.5 mus pulses at 60 Hz repetition rate. One run was executed at a temperature rise of 120 K for 56 x 10(6) pulses. Cracks at grain boundaries, slip bands, and cracks associated with these slip bands were observed. The second run consisted of 86 x 10(6) pulses with a temperature rise of 82 K, and cracks at grain boundaries and slip bands were seen. Additional information can be derived from the power-coupling iris, and we conclude that a pulsed temperature rise of 250 K for several million pulses leads to destruction of copper. These results can be applied to any mode of any OFE copper cavity. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Pritzkau, DP (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 20 TC 40 Z9 40 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD NOV PY 2002 VL 5 IS 11 AR 112002 DI 10.1103/PhysRevSTAB.5.112002 PG 22 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 622CX UT WOS:000179629900003 ER PT J AU Zank, GP Zhou, Y Matthaeus, WH Rice, WKM AF Zank, GP Zhou, Y Matthaeus, WH Rice, WKM TI The interaction of turbulence with shock waves: A basic model SO PHYSICS OF FLUIDS LA English DT Article ID NOISE AB The interaction of turbulence and shock waves is considered self-consistently so that the back-reaction of the turbulence and its associated reaction on the turbulence is addressed. This approach differs from previous studies which considered the interaction of linear modes with a shock. The most basic model of hypersonic flow, described by the inviscid form of Burgers' equation, is used. An energy-containing model which couples the turbulent energy density and correlation length of the flow with the mean flow is developed. Upstream turbulence interacting with a shock wave is found to mediate the shock by (1) increasing the mean shock speed, and (2) decreasing the efficiency of turbulence amplification at the shock as the upstream turbulence energy density is increased. The implication of these results is that the energy in upstream turbulent fluctuations, while being amplified at the shock, is also being converted into mean flow energy downstream. The variance in both the shock speed and position is computed, leading to the suggestion that, in an ensemble-averaged sense, the turbulence mediated shock will acquire a characteristic thickness given by the standard deviation of the shock position. Lax's geometric entropy condition is used to show that as the upstream turbulent energy density increases, the shock is eventually destabilized, and may emit one or more shocks to produce a system of multiple shock waves. Finally, turbulence downstream of the shock is shown to decay in time t according to t(-2/3). (C) 2002 American Institute of Physics. C1 Univ Calif Riverside, IGPP, Riverside, CA 92521 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. RP Zank, GP (reprint author), Univ Calif Riverside, IGPP, Riverside, CA 92521 USA. RI Rice, Ken/H-5084-2011 OI Rice, Ken/0000-0002-6379-9185 NR 21 TC 18 Z9 18 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 2002 VL 14 IS 11 BP 3766 EP 3774 DI 10.1063/1.1507772 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 603AQ UT WOS:000178537000006 ER PT J AU White, JM Muller, SJ AF White, JM Muller, SJ TI The role of thermal sensitivity of fluid properties, centrifugal destabilization, and nonlinear disturbances on the viscous heating instability in Newtonian Taylor-Couette flow SO PHYSICS OF FLUIDS LA English DT Article ID STABILITY AB A number of questions regarding the effects of viscous dissipation on the stability of Newtonian Taylor-Couette flows are addressed through flow visualization experiments. Studies with three types of fluids of varying thermal sensitivity reveal that the instability is caused by a coupling of centrifugal destabilization and thermally induced gradients in viscosity. These tests also demonstrate that the Nahme number is the appropriate variable with which to describe dissipative effects on the hydrodynamic stability. Additional tests are performed to elucidate the effects of centrifugal destabilization by varying the amount of outer and inner cylinder co-rotation with the Reynolds number and Nahme number fixed. Lastly, a small hysteresis loop in the critical conditions is revealed by performing ramp tests in which the instability is approached from either above or below the critical condition; this indicates that the instability is weakly subcritical. (C) 2002 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP White, JM (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 15 TC 14 Z9 14 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 2002 VL 14 IS 11 BP 3880 EP 3890 DI 10.1063/1.1509067 PG 11 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 603AQ UT WOS:000178537000016 ER PT J AU Girgis, IG Brown, GL Miles, RB Lipinski, RJ AF Girgis, IG Brown, GL Miles, RB Lipinski, RJ TI Fluid mechanics of a Mach 7-12, electron-beam driven, missile-scale hypersonic wind tunnel: Modeling and predictions SO PHYSICS OF FLUIDS LA English DT Article AB Models of increasing complexity have been developed for the design and simulation of the axisymmetric inviscid fluid mechanics and energy addition of an electron-beam driven hypersonic wind tunnel for missile-scale testing and development. The principal target has been a Mach-12 capability at altitudes of approximately 25 km and above with a test section of 1.3 m. Also, results for lower Mach numbers at lower altitudes down to Mach-7 at 2 km have been obtained. The fully coupled e-beam and Euler flow simulation shows that with a magnetically guided, 3 MeV e-beam and a nozzle geometry determined from the solution to an optimization problem, shock waves can be eliminated notwithstanding the very high radiative power (200 MW) that is deposited into the core flow (away from the boundary layer). While there remain many issues to be resolved, we have not yet found an intrinsic problem with either the concept or its application to such long run time, missile-scale, facilities. (C) 2002 American Institute of Physics. C1 Princeton Univ, Princeton, NJ 08544 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Brown, GL (reprint author), Princeton Univ, Princeton, NJ 08544 USA. NR 12 TC 2 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 2002 VL 14 IS 11 BP 4026 EP 4039 DI 10.1063/1.1501826 PG 14 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 603AQ UT WOS:000178537000028 ER PT J AU Barnes, CW Batha, SH Dunne, AM Magelssen, GR Rothman, S Day, RD Elliott, NE Haynes, DA Holmes, RL Scott, JM Tubbs, DL Youngs, DL Boehly, TR Jaanimagi, P AF Barnes, CW Batha, SH Dunne, AM Magelssen, GR Rothman, S Day, RD Elliott, NE Haynes, DA Holmes, RL Scott, JM Tubbs, DL Youngs, DL Boehly, TR Jaanimagi, P TI Observation of mix in a compressible plasma in a convergent cylindrical geometry SO PHYSICS OF PLASMAS LA English DT Article ID RICHTMYER-MESHKOV INSTABILITY; RAYLEIGH-TAYLOR INSTABILITY; DIRECT-DRIVE; IMPLOSION EXPERIMENTS; NUMERICAL-SIMULATION; OMEGA LASER; EVOLUTION AB Laser beams that directly drive a cylindrical implosion are used to create a measurable region of mixed material in a compressible plasma state, for the first time in a convergent geometry. The turbulence driven by the Richtmyer-Meshkov instability by shock passage across a density discontinuity mixes marker material that is radiographically opaque. The width of the mix layer is compared between a system with large surface roughness and an initially smooth system. The experiment is described and results are compared to multi-dimensional numerical simulation, including three-dimensional turbulence calculations. The calculations adequately match the observations provided the measured initial conditions are used. (C) 2002 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Madison, WI USA. RP Barnes, CW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Dunne, Mike/B-4318-2014 OI Dunne, Mike/0000-0001-8740-3870 NR 22 TC 30 Z9 30 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4431 EP 4434 DI 10.1063/1.1511730 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900002 ER PT J AU Barnes, DC Chacon, L Finn, JM AF Barnes, DC Chacon, L Finn, JM TI Equilibrium and low-frequency stability of a uniform density, collisionless, spherical Vlasov system SO PHYSICS OF PLASMAS LA English DT Article ID OSCILLATING PLASMA SPHERE; PENNING FUSION SYSTEMS; CONFINEMENT; FOCUS; TRAP AB Equilibrium and stability of a collisionless, spherical Vlasov system with uniform density are considered. Such an electron system is useful for the Periodically Oscillating Plasma Sphere (POPS) fusion system. In POPS the space charge of a uniform-density spherical electron cloud provides a harmonic well for an under-dense thermal ion population. Previous special solutions [D. C. Barnes, Phys. Plasmas 6, 4472 (1999)] are extended to arbitrary energy dependence. These equilibrium distribution functions and their first derivatives may be made nonsingular, in contrast to the previous solutions. Linear stability of general spherical equilibria is considered, and reduced to a one-dimensional calculation by the introduction of a spherical harmonic decomposition. All azimuthal mode numbers are degenerate. Using this formalism, the low-frequency stability of a collisionless, spherical Vlasov electron system coupled to a minority ion cloud is studied for the class of uniform-density electron equilibria found. In the low-frequency (adiabatic) limit, the general kinetic stability formalism can be integrated to find a closed form for the response of electron number density. The adiabatic response operator is shown to be self-adjoint. Computation of its eigenvalues proves the constant-density electrons/thermal ions system in POPS to be mostly stable to ion-electron electrostatic modes. Unstable modes are avoided unless central electrons have an extremely small energy spread. These results may also be useful for the consideration of gravitational and beam systems. (C) 2002 American Institute of Physics. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Barnes, DC (reprint author), Los Alamos Natl Lab, Div Appl Phys, B-259, Los Alamos, NM 87545 USA. NR 18 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4448 EP 4464 DI 10.1063/1.1510667 PG 17 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900005 ER PT J AU Rosenberg, AL Gates, DA Pletzer, A Menard, JE Kruger, SE Hegna, CC Paoletti, F Sabbagh, S AF Rosenberg, AL Gates, DA Pletzer, A Menard, JE Kruger, SE Hegna, CC Paoletti, F Sabbagh, S TI Modeling of neoclassical tearing mode stability for generalized toroidal geometry SO PHYSICS OF PLASMAS LA English DT Article ID REGION MATCHING DATA; NONLINEAR DYNAMICS; MAGNETIC ISLANDS; PRESSURE; CURVATURE; TOKAMAKS; SYSTEMS; PHYSICS AB Neoclassical tearing modes (NTMs) can lead to disruption and loss of confinement. Previous analysis of these modes used large aspect ratio, low beta (plasma pressure/magnetic pressure) approximations to determine the effect of NTMs on tokamak plasmas. A more accurate tool is needed to predict the onset of these instabilities. As a follow-up to recent theoretical work, a code has been written which computes the tearing mode island growth rate for arbitrary tokamak geometry. It calls PEST-3 [A. Pletzer , J. Comput. Phys. 115, 530 (1994)] to compute Delta('), the resistive magnetohydrodynamic (MHD) matching parameter. The code also calls the FLUXGRID routines in NIMROD [A. H. Glasser , Plasma Phys. Controlled Fusion 41, A747 (1999)] for D-nc, D-I, and D-R [C. C. Hegna, Phys. Plasmas 6, 3980 (1999); A. H. Glasser , Phys. Fluids 18, 875 (1975)], which are the bootstrap current driven term and the ideal and resistive interchange mode criterion, respectively. In addition to these components, the NIMROD routines calculate alpha(s)-H, a new correction to the Pfirsch-Schluter term. Finite parallel transport effects were added and a National Spherical Torus Experiment (NSTX) [M. Ono , Nucl. Fusion 40, 557 (2000)] equilibrium was analyzed. Another program takes the output of PEST-3 and allows the user to specify the rational surface, island width, and amount of detail near the perturbed surface to visualize the total helical flux. The results of this work will determine the stability of NTMs in a spherical torus (ST) [Y.-K. M. Peng , Nucl. Fusion 26, 769 (1986)] plasma with greater accuracy than previously achieved. (C) 2002 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Sci Applicat Int Corp, San Diego, CA 92121 USA. Dept Engn Phys, Madison, WI 53706 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. RP Rosenberg, AL (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Sabbagh, Steven/C-7142-2011; OI Menard, Jonathan/0000-0003-1292-3286 NR 18 TC 6 Z9 6 U1 1 U2 13 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4567 EP 4572 DI 10.1063/1.1512285 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900020 ER PT J AU Chu, MS La Haye, RJ Austin, ME Lao, LL Lazarus, EA Pletzer, A Ren, C Strait, EJ Taylor, TS Waelbroeck, FL AF Chu, MS La Haye, RJ Austin, ME Lao, LL Lazarus, EA Pletzer, A Ren, C Strait, EJ Taylor, TS Waelbroeck, FL TI Study of a low beta classical tearing mode in DIII-D SO PHYSICS OF PLASMAS LA English DT Article ID MAGNETIC ISLAND EVOLUTION; FUSION TEST REACTOR; MHD MODES; STABILIZATION; STABILITY; TOKAMAKS; DELTA'; TFTR AB The tearing mode stability of low beta plasmas is studied experimentally in the DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] tokamak. The linear and nonlinear characteristics of the plasma are measured and compared with theoretical predictions. In contrast to the neoclassical tearing mode, which occurs at high beta and is dominated by the bootstrap current effect, in the low beta regime the neoclassical bootstrap current effect is minimal. Thus the stability properties are more amenable to comparison with presently available theoretical codes. In the linear phase, the onset of the instability has been found to be predictable from equilibrium reconstruction to agree with the availability of the tearing mode free energy. In the nonlinear phase, the temperature and its fluctuation amplitude and phase have been fitted to the prediction of achieving a perturbed three-dimensional equilibrium with an assumed perturbation eigenfunction. (C) 2002 American Institute of Physics. C1 Gen Atom Co, San Diego, CA 92186 USA. Univ Texas, Dept Phys, Austin, TX 78712 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Chu, MS (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. RI Waelbroeck, Francois/B-6988-2008 OI Waelbroeck, Francois/0000-0001-9324-3690 NR 19 TC 19 Z9 20 U1 2 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4584 EP 4590 DI 10.1063/1.1510666 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900022 ER PT J AU Zakharov, LE AF Zakharov, LE TI Stabilization of tokamak plasma by lithium streams SO PHYSICS OF PLASMAS LA English DT Article ID RESISTIVE WALL MODE; ROTATION; STABILITY; GEOMETRY; IDEAL AB The theory of stabilizing free-boundary magnetohydrodynamic instabilities in tokamaks by liquid lithium streams driven by magnetic propulsion is formulated. It is shown that even for uniform current distribution lithium streams open stability windows. Also, it was found that while the conventional, wall-locked, resistive wall mode can be well suppressed by the flow, a new, stream-locked mode determines the limits of the flow stabilization. (C) 2002 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Zakharov, LE (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4591 EP 4595 DI 10.1063/1.1512655 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900023 ER PT J AU Yamada, H Katano, T Kanai, K Ishida, A Steinhauer, LC AF Yamada, H Katano, T Kanai, K Ishida, A Steinhauer, LC TI Equilibrium analysis of a flowing two-fluid plasma SO PHYSICS OF PLASMAS LA English DT Article ID FIELD-REVERSED CONFIGURATIONS; STABILITY; MAGNETOFLUID; RELAXATION; VELOCITY; SHEAR AB An improved formalism for a flowing two-fluid equilibrium with constant density is developed. This extends the usual single-fluid model. In this generalization, the magnetic field is replaced by two quantities, the generalized vorticities of each species. Criteria are found for when the single-fluid model is adequate and when the more general two-fluid model is necessary. The two-dimensional equilibria with purely azimuthal ion flow are studied analytically and numerically. Spherical torus and compact toroid equilibria are found that are relevant to the current experiment. The ion flow and plasma beta as well as the size parameter are found to play a major role in the question of whether two-fluid corrections are needed. (C) 2002 American Institute of Physics. C1 Niigata Univ, Grad Sch Sci & Technol, Niigata 9502181, Japan. Niigata Univ, Fac Sci, Dept Environm Sci, Niigata 9502181, Japan. Univ Washington, Redmond Plasma Phys Lab, Redmond, WA 98052 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08544 USA. RP Yamada, H (reprint author), Kyoto Univ, Grad Sch Energy Sci, Kyoto 6110011, Japan. NR 21 TC 16 Z9 16 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4605 EP 4614 DI 10.1063/1.1510125 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900025 ER PT J AU Froula, DH Divol, L Baldis, HA Berger, RL Braun, DG Cohen, BI Johnson, RP Montgomery, DS Williams, EA Glenzer, SH AF Froula, DH Divol, L Baldis, HA Berger, RL Braun, DG Cohen, BI Johnson, RP Montgomery, DS Williams, EA Glenzer, SH TI Observation of ion heating by stimulated-Brillouin-scattering-driven ion-acoustic waves using Thomson scattering SO PHYSICS OF PLASMAS LA English DT Article ID DEFINED INTERACTION CONDITIONS; LASER-LIGHT; PLASMAS; INSTABILITY; SIMULATIONS; FREQUENCY AB Thomson-scattering measurements of the growth of ion-acoustic waves are obtained from well-characterized multi-ion-species plasmas consisting of gold and beryllium. Simultaneously, the ion temperature is accurately measured by comparing the relative amplitude of thermal ion-acoustic modes. A twofold increase in ion temperature was measured when ion-acoustic waves are excited to large amplitudes by stimulated Brillouin scattering (SBS). This increase in ion temperature is a strong indication of hot ions due to trapping. The measured SBS reflectivity is explained by nonlinear detuning of the SBS instability due to these trapping effects. (C) 2002 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Davis, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Inst Laser Sci Applicat, Livermore, CA 94551 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Froula, DH (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. OI Montgomery, David/0000-0002-2355-6242 NR 28 TC 16 Z9 16 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4709 EP 4718 DI 10.1063/1.1508776 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900035 ER PT J AU Kaganovich, ID AF Kaganovich, ID TI How to patch active plasma and collisionless sheath: A practical guide SO PHYSICS OF PLASMAS LA English DT Article ID DISCHARGE AB Most plasmas have a very thin sheath compared with the plasma dimension. This necessitates separate calculations of the plasma and sheath. The Bohm criterion provides the boundary condition for calculation of plasma profiles. To calculate sheath properties a value of the electric field at the plasma-sheath interface has to be specified in addition to the Bohm criterion. The value of the boundary electric field and a robust procedure to approximately patch plasma and collisionless sheath with a very good accuracy are reported. (C) 2002 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kaganovich, ID (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 17 TC 39 Z9 39 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2002 VL 9 IS 11 BP 4788 EP 4793 DI 10.1063/1.1515274 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 607KC UT WOS:000178789900044 ER PT J AU Bigi, I Bolton, T Formaggio, J Harris, DA Kayser, B King, BJ McFarland, KS Morfin, J Petrov, AA Schellman, H Shrock, R Spentzouris, PG Velasco, M Yu, J AF Bigi, I Bolton, T Formaggio, J Harris, DA Kayser, B King, BJ McFarland, KS Morfin, J Petrov, AA Schellman, H Shrock, R Spentzouris, PG Velasco, M Yu, J TI The potential for neutrino physics at muon colliders and dedicated high current muon storage rings SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE muon colliders; muon storage rings; neutrino factories ID MOLLER SCATTERING ASYMMETRIES; NUCLEAR-STRUCTURE FUNCTIONS; DEEP-INELASTIC SCATTERING; BASE-LINE EXPERIMENTS; SMITH SUM-RULE; CP-VIOLATION; SUPER-KAMIOKANDE; OSCILLATION EXPERIMENTS; ATMOSPHERIC NEUTRINOS; PRECISION-MEASUREMENT AB Conceptual design studies are underway for muon colliders and other high-current muon storage rings that have the potential to become the first true "neutrino factories". Muon decays in long straight sections of the storage rings would produce precisely characterized beams of electron and muon type neutrinos of unprecedented intensity. This article reviews the prospects for these facilities to greatly extend our capabilities for neutrino experiments, largely emphasizing the physics of neutrino interactions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Notre Dame, South Bend, IN USA. Kansas State Univ, Manhattan, KS 66506 USA. Columbia Univ, New York, NY 10032 USA. Fermilab Natl Accelerator Lab, Batavia, IL USA. Natl Sci Fdn, Washington, DC 20550 USA. Univ Rochester, Rochester, NY 14642 USA. Cornell Univ, LNS, Ithaca, NY 14853 USA. Northwestern Univ, Evanston, IL 60208 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. EM king@lotus.phys.nwu.edu RI Petrov, Alexey/F-2882-2010 NR 206 TC 4 Z9 4 U1 0 U2 1 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 NOV PY 2002 VL 371 IS 3 BP 151 EP 230 AR PII S0370-1573(02)00011-X DI 10.1016/S0370-1573(02)00011-X PG 80 WC Physics, Multidisciplinary SC Physics GA 613PQ UT WOS:000179141000001 ER PT J AU Martinez, J Krause, H Bederson, B AF Martinez, J Krause, H Bederson, B TI Sheldon Datz - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 US DOE, Washington, DC USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NYU, New York, NY 10012 USA. RP Martinez, J (reprint author), US DOE, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 2002 VL 55 IS 11 BP 88 EP 90 PG 3 WC Physics, Multidisciplinary SC Physics GA 610HN UT WOS:000178954800020 ER PT J AU Dreicer, H Montgomery, DC Symon, KR Turner, L AF Dreicer, H Montgomery, DC Symon, KR Turner, L TI Harold Ralph Lewis - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Dartmouth Coll, Hanover, NH 03755 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Dreicer, H (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 2002 VL 55 IS 11 BP 90 EP 91 DI 10.1063/1.1535021 PG 2 WC Physics, Multidisciplinary SC Physics GA 610HN UT WOS:000178954800021 ER PT J AU Ianniello, LC Gottschall, RJ AF Ianniello, LC Gottschall, RJ TI Donald Keith Stevens - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 US DOE, Germantown, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 2002 VL 55 IS 11 BP 92 EP 93 DI 10.1063/1.1535024 PG 2 WC Physics, Multidisciplinary SC Physics GA 610HN UT WOS:000178954800024 ER PT J AU Crease, RP AF Crease, RP TI Much more than pretty pictures SO PHYSICS WORLD LA English DT Editorial Material C1 SUNY Stony Brook, Dept Philosophy, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Crease, RP (reprint author), SUNY Stony Brook, Dept Philosophy, Stony Brook, NY 11794 USA. NR 0 TC 17 Z9 18 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD NOV PY 2002 VL 15 IS 11 BP 19 EP 19 PG 1 WC Physics, Multidisciplinary SC Physics GA 620JW UT WOS:000179531100016 ER PT J AU Hale, KL Tufan, HA Pickering, IJ George, GN Terry, N Pilon, M Pilon-Smits, EAH AF Hale, KL Tufan, HA Pickering, IJ George, GN Terry, N Pilon, M Pilon-Smits, EAH TI Anthocyanins facilitate tungsten accumulation in Brassica SO PHYSIOLOGIA PLANTARUM LA English DT Article ID GLUTATHIONE S-TRANSFERASES; LEAVES; COLOR; SEQUESTRATION; SENSITIVITY; MONTANUM; NICKEL; GENE AB Accumulation of molybdenum in Brassica was recently found to be correlated with anthocyanin content, involving the formation of a blue complex. Here the role of anthocyanins in tungsten sequestration was investigated using three species of Brassica : B. rapa (cv. Fast plants), B. juncea (Indian mustard) and B. oleracea (red cabbage). Seedlings of B. rapa and B. juncea turned blue when supplied with colourless tungstate. The blue compound co-localized with anthocyanins in the peripheral cell layers, and the degree of blueness was correlated with anthocyanin content. The direct involvement of anthocyanins in the blue coloration was evident when purified anthocyanins showed a colour change from pink to blue in vitro upon addition of tungstate, over a wide pH range. Anthocyanin production was upregulated 3-fold by W in B. juncea , possibly reflecting a function for anthocyanins in W tolerance or sequestration. The presence of anthocyanins facilitated W accumulation in B. rapa : anthocyanin-containing seedlings accumulated 3-fold more W than an anthocyaninless mutant. There was no correlation between anthocyanin content and W tolerance under these conditions. The nature of the interaction between anthocyanins and tungstate was investigated. X-ray absorption spectroscopy showed no change in the local chemical environment of W upon uptake of tungstate by the plant; HPLC analysis of purified anthocyanin with or without tungstate showed no peak shift after metal treatment. C1 Colorado State Univ, Dept Biol, Ft Collins, CO 80523 USA. SLAC, Stanford Synchrotron Res Lab, Stanford, CA 94309 USA. Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. RP Pilon-Smits, EAH (reprint author), Colorado State Univ, Dept Biol, Anat Zool Bldg, Ft Collins, CO 80523 USA. RI George, Graham/E-3290-2013; Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 NR 29 TC 33 Z9 39 U1 4 U2 41 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0031-9317 J9 PHYSIOL PLANTARUM JI Physiol. Plant. PD NOV PY 2002 VL 116 IS 3 BP 351 EP 358 DI 10.1034/j.1399-3054.2002.1160310.x PG 8 WC Plant Sciences SC Plant Sciences GA 604WW UT WOS:000178644900010 ER PT J AU Wullschleger, SD Jansson, S Taylor, G AF Wullschleger, SD Jansson, S Taylor, G TI Genomics and forest biology: Populus emerges as the perennial favorite SO PLANT CELL LA English DT Editorial Material ID POPLAR; TREE C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Umea Univ, Dept Plant Physiol, Umea Plant Sci Ctr, SE-90187 Umea, Sweden. Univ Southampton, Sch Biol Sci, Southampton SO16 7PX, Hants, England. RP Wullschleger, SD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Wullschleger, Stan/B-8297-2012; Jansson, Stefan/A-1119-2009 OI Wullschleger, Stan/0000-0002-9869-0446; Jansson, Stefan/0000-0002-7906-6891 NR 6 TC 107 Z9 122 U1 0 U2 5 PU AMER SOC PLANT BIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 1040-4651 J9 PLANT CELL JI Plant Cell PD NOV PY 2002 VL 14 IS 11 BP 2651 EP 2655 DI 10.1105/tpc.141120 PG 5 WC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology SC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology GA 615UF UT WOS:000179264700002 PM 12417692 ER PT J AU Hoffmann-Benning, S Gage, DA McIntosh, L Kende, H Zeevaart, JAD AF Hoffmann-Benning, S Gage, DA McIntosh, L Kende, H Zeevaart, JAD TI Comparison of peptides in the phloem sap of flowering and non-flowering Perilla and lupine plants using microbore HPLC followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry SO PLANTA LA English DT Article DE MALDI-TOF-MS; peptide; Perilla ocymoides; phloem sap; proteomics ID POLYACRYLAMIDE-GEL-ELECTROPHORESIS; COMMUNIS L SEEDLINGS; SIEVE-TUBE EXUDATE; MESSENGER-RNA; MAXIMA DUCH.; PROTEINS; PHOSPHORYLATION; IDENTIFICATION; TRANSPORTERS; TRAFFICKING AB Physiological evidence indicates that flower formation is hormonally controlled. The floral stimulus, or florigen, is formed in the leaves as a response to an inductive photoperiod and translocated through the phloem to the apical meristem. However, because of difficulties in obtaining and analyzing phloem sap and the lack of a bioassay, the chemical nature of this stimulus is one of the major unsolved problems in plant biology. A combination of microbore high-performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to compare the contents of the phloem sap from flowering and nonflowering plants. Instead of using one- or two-dimensional gel electrophoresis, microbore HPLC separations allowed us to detect proteins/peptides that were very small and present at very low levels. We detected more than 100 components in the phloem sap of Perilla ocymoides L. and Lupinus albus L. Sequences for 16 peptides in a mass range from 1 to 9 kDa were obtained. Two of these could be identified, 11 showed similarity to known or deduced protein sequences, and three showed no similarity to any known protein or translated gene sequence. Four of these peptides were specific to, modified, or increased in plants that were flowering, indicating their possible role in flower induction. The sequences of these peptides showed similarities to two purine permeases, a protein with similarity to protein kinases, and a protein with no similarities to any known protein. C1 Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Plant Biol, E Lansing, MI 48824 USA. Michigan State Univ, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. RP Kende, H (reprint author), Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. NR 25 TC 31 Z9 33 U1 1 U2 8 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0032-0935 J9 PLANTA JI Planta PD NOV PY 2002 VL 216 IS 1 BP 140 EP 147 DI 10.1007/s00425-002-0916-0 PG 8 WC Plant Sciences SC Plant Sciences GA 624VD UT WOS:000179781700015 PM 12430023 ER PT J AU Soukhanovskii, A Finkenthal, M Moos, HW Stutman, D Munsat, T Jones, B Hoffman, D Kaita, R Majeski, R AF Soukhanovskii, A Finkenthal, M Moos, HW Stutman, D Munsat, T Jones, B Hoffman, D Kaita, R Majeski, R TI Observation of neoclassical impurity transport in ohmically heated plasmas of CDX-U low aspect ratio tokamak SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID SPHERICAL TORUS; INTERNAL DISRUPTIONS; ANOMALOUS TRANSPORT; BOOTSTRAP CURRENT; PELLET INJECTION; ATOMIC DATABASE; EMISSION-LINES; CURRENT DRIVE; DIAGNOSTICS; DENSITY AB High beta, good confinement and stability properties of the low aspect ratio tokamaks, or spherical tori (ST), have been predicted theoretically and preliminarily confirmed in several large experiments recently. This paper reports on impurity transport experiments carried out in ohmically heated plasmas of the small spherical torus CDX-U with the aspect ratio of A similar or equal to 1.5. Vacuum ultraviolet and soft x-ray multichannel spectroscopic diagnostics are used to measure intrinsic carbon, oxygen and radiated power radial brightness profiles in plasmas with T(e) (0) similar or equal to 60-80 eV and n(e) (0) similar or equal to 2 x 10(13) cm(-3): The measurements are performed in both magnetohydrodynamically dorminated and quiescent phase of the plasmas. The properties of the observed low m / n modes, sawtooth oscillations, and ST-specific reconnection events are discussed in the context of particle transport. The, measured impurity profiles are modelled using one-dimensional impurity transport code MIST and a collisional-radiative package CRMLIN. Impurity diffusion of 0.2 m(2) s(-1) less than or equal to D less than or equal to 0.6 m(2)s(-1) and convection velocity of nu similar or equal to 4-16 m s(-1) are inferred from the modelling. These transport coefficients are very close to the neoclassical theory predictions obtained with the FORCEBAL code,. which uses analytical plasma viscosity expressions valid for an arbitrary aspect ratio geometry. Neoclassical analysis indicates that both carbon and- oxygen are in the collisional regime, and the Pfirsch-Schluter flux is the major fraction of the impurity flux. The causes of the observed strong non-diffusive transport are discussed, and it is concluded that the deln(i)/n(i) term, resulting from highly peaked ion density profile, makes the largest contribution to the inward pinch. Present analysis suggests that drift wave turbulence is reduced in CDX-U ohmically heated discharges within at least r/a less than or equal to 0.4, however more refined measurements are needed to interpret the results in the framework of ST ion transport. C1 Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Johns Hopkins Univ, Dept Phys & Astron, Plasma Spect Grp, Baltimore, MD 21218 USA. RP Soukhanovskii, A (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM vlad@pppl.gov RI Stutman, Dan/P-4048-2015 NR 73 TC 2 Z9 2 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD NOV PY 2002 VL 44 IS 11 BP 2339 EP 2355 AR PII S0741-3335(02)38339-8 DI 10.1088/0741-3335/44/11/304 PG 17 WC Physics, Fluids & Plasmas SC Physics GA 622RK UT WOS:000179660600005 ER PT J AU Fitch, JP Gardner, SN Kuczmarski, TA Kurtz, S Myers, R Ott, LL Slezak, TR Vitalis, EA Zemla, AT McCready, PM AF Fitch, JP Gardner, SN Kuczmarski, TA Kurtz, S Myers, R Ott, LL Slezak, TR Vitalis, EA Zemla, AT McCready, PM TI Rapid development of nucleic acid diagnostics SO PROCEEDINGS OF THE IEEE LA English DT Article DE deoxyribonucleic acid (DNA); diagnostics; genomics; nucleic acid; ribonucleic acid (RNA); suffix tree ID MULTIPLE SEQUENCE ALIGNMENT; POLYMERASE CHAIN-REACTION; MOUTH-DISEASE; DNA-SEQUENCE; HUMAN-GENOME AB There has been a significant increase, fueled by technologies from the human genome project, in the availability of nucleic acid sequence information for viruses and bacteria. This paper presents a computer-assisted process that begins with nucleic acid sequence information and produces highly specific pathogen signatures. When combined with instrumentation using the polymerase chain reaction, the resulting diagnostics are both specific and sensitive. The computational and engineering aspects of converting raw sequence data into pathogen-specific and instrument-ready assays are presented. Examples and data are presented for specific pathogens, including foot-and-mouth disease virus and the human immunodeficiency virus. C1 Lawrence Livermore Natl Lab, Chem & Biol Natl Secur Program, Livermore, CA 94550 USA. Ctr Dis Control & Prevent, Atlanta, GA 30303 USA. Univ Hamburg, Ctr Bioinformat, Hamburg, Germany. RP Fitch, JP (reprint author), Lawrence Livermore Natl Lab, Chem & Biol Natl Secur Program, Livermore, CA 94550 USA. EM jpfitch@llnl.gov NR 37 TC 26 Z9 28 U1 2 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD NOV PY 2002 VL 90 IS 11 BP 1708 EP 1721 DI 10.1109/JPROC.2002.804680 PG 14 WC Engineering, Electrical & Electronic SC Engineering GA 614RQ UT WOS:000179204700003 ER PT J AU Romero, MJ Al-Jassim, MM Dhere, RG Hasoon, FS Contreras, MA Gessert, TA Moutinho, HR AF Romero, MJ Al-Jassim, MM Dhere, RG Hasoon, FS Contreras, MA Gessert, TA Moutinho, HR TI Beam injection methods for characterizing thin-film solar cells SO PROGRESS IN PHOTOVOLTAICS LA English DT Article ID PHOTOLUMINESCENCE; TEMPERATURE; DIFFUSION; CUINSE2; CDTE; CU AB II-VI and I-III-VI solar cells are promising for future thin-film photovoltaics. In this paper, the roles of electron-beam-induced current (EBIC) and cathodoluminescence in evaluating the influence of interfaces on those solar cells are reviewed. CdTe and Cu(In,Ga)Se-2 (CIGS) are the absorbers of the cells investigated. For CdTe/CdS solar cells, a detailed study has been conducted of the effects of grain boundaries and the Te/CdTe or ZnTe:Cu/CdTe interfaces for back-contacting. For CIGS solar cells, we have investigated different buffer layer schemes, showing that these interfaces are critical in the definition of the mechanisms for carrier collection. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Romero, MJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 15 TC 20 Z9 20 U1 0 U2 22 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD NOV PY 2002 VL 10 IS 7 BP 445 EP 455 DI 10.1002/pip.437 PG 11 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 607NQ UT WOS:000178798000001 ER PT J AU Chaparro, AM Gutierrez, MT Herrero, J Klaer, J Romero, MJ Al-Jassim, MM AF Chaparro, AM Gutierrez, MT Herrero, J Klaer, J Romero, MJ Al-Jassim, MM TI Characterisation of CuInS2/Zn(Se,O)/ZnO solar cells as a function of Zn(Se,O) buffer deposition kinetics in a chemical bath SO PROGRESS IN PHOTOVOLTAICS LA English DT Article ID ZNSE THIN-FILMS; PHOTOLUMINESCENCE; CU(IN,GA)SE-2; SODIUM; XPS AB Thin-film solar cells of CuInS2/Zn(Se,O)/ZnO configuration have been studied from the point of view of their dependence on the Zn(Se,O) chemical bath deposition (CBD) conditions. The kinetics of deposition of the Zn(Se,O) buffer is followed during cell processing with a quartz crystal microbalance (QCM). Two different CBD growth mechanisms yield buffer layers with different properties. Under a predominant electroless deposition reaction, the resulting buffer layer has mixed ZnSe-ZnO composition. The solar cells with this buffer type show higher fill factor (FF) and lower open-circuit voltage (V-oc). Under a chemical growth regime, the buffer layer has higher ZnSe proportion, giving rise to cells with higher V-OC, but lower FF and stability. The parameters of this second type of cell also show major dependence on illumination effects (light-soaking effects). Electron-beam-induced current (EBIC) and cathodoluminescence (CL) measurements are carried out to characterise the CuInS2/Zn(Se,O) junctions formed under the two buffer growth regimes. Cross-sectional EBIC shows a wider space charge region (SCR) than expected for p-CuInS2 in contact with Zn(Se,O), and the p-n junction is driven within the CuInS2 phase. These results reflect a chemical modification of CuInS2, most probably caused by the ammonia of the bath solution. CL shows more defective interfaces when Zn(Se,O) is deposited under the chemical mechanism (slower deposition rate, hence longer contact time of the CuInS2 with the bath solution) than under the electroless kinetics (faster deposition rate). Copyright (C) 2002 John Wiley Sons, Ltd. C1 CIEMAT, Dept Renewable Energy, E-28040 Madrid, Spain. Hahn Meitner Inst SE3, D-14109 Berlin, Germany. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Chaparro, AM (reprint author), CIEMAT, Dept Renewable Energy, Ave Complutense 22, E-28040 Madrid, Spain. RI Chaparro, Antonio/J-8775-2014; Herrero, Jose/K-2711-2014 OI Chaparro, Antonio/0000-0001-6822-4797; Herrero, Jose/0000-0002-2680-7019 NR 28 TC 14 Z9 14 U1 1 U2 8 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD NOV PY 2002 VL 10 IS 7 BP 465 EP 480 DI 10.1002/pip.441 PG 16 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 607NQ UT WOS:000178798000003 ER PT J AU Kitazawa, M Koide, T Kunihiro, T Nemoto, Y AF Kitazawa, M Koide, T Kunihiro, T Nemoto, Y TI Chiral and color-superconducting phase transitions with vector interaction in a simple model SO PROGRESS OF THEORETICAL PHYSICS LA English DT Article ID JONA-LASINIO MODEL; DENSITY QUARK MATTER; FINITE BARYON DENSITY; SYMMETRY-BREAKING; RANDOM-MATRIX; 2-COLOR QCD; TEMPERATURE; NAMBU; FLAVOR; RESTORATION AB We investigate effects of the vector interaction on chiral and color superconducting (CSC) phase transitions at finite density and temperature in a simple Nambu-Jona-Lasinio model. It is shown that the repulsive density-density interaction coming from the vector term, which is present in the effective chiral models but has been omitted, enhances the competition between the chiral symmerty breaking (chiSB) and CSC phase transition, and thereby makes the thermodynamic potential have a shallow minimum over a wide range of values of the correlated chiral and CSC order parameters. We find that when the vector coupling is increased, the first order transition between the chiSB and CSC phases becomes weaker,and the coexisting phase in which both the chiral and color-gauge symmetry are dynamically broken comes to exisit over a wider range of the density and temperature. We also show that there can exist two endpoints, which are tricritical points in the chiral limit, along the critical line of the first order transition in some range of values of the vector coupling. Although our analysis is based on a simple model, the nontrivial interplay between the chiSB and CSC phases induced by the vector interaction is expected to be a universal phenomenon and might give a clue to understanding results obtained with two-color QCD on the lattice. C1 Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan. RIKEN, BNL, Res Ctr, Upton, NY 11973 USA. RP Kitazawa, M (reprint author), Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. NR 79 TC 105 Z9 105 U1 0 U2 1 PU PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE PI KYOTO PA C/O KYOTO UNIV, YUKAWA HALL, KYOTO, 606-8502, JAPAN SN 0033-068X J9 PROG THEOR PHYS JI Prog. Theor. Phys. PD NOV PY 2002 VL 108 IS 5 BP 929 EP 951 DI 10.1143/PTP.108.929 PG 23 WC Physics, Multidisciplinary SC Physics GA 625NU UT WOS:000179823200008 ER PT J AU Ortiz, AR Strauss, CEM Olmea, O AF Ortiz, AR Strauss, CEM Olmea, O TI MAMMOTH (Matching molecular models obtained from theory): An automated method for model comparison SO PROTEIN SCIENCE LA English DT Article DE protein structural alignment; model evaluation; protein structure prediction; structural genomics ID PROTEIN-STRUCTURE PREDICTION; MULTIPLE STRUCTURE ALIGNMENT; TO-FUNCTION PARADIGM; STRUCTURAL GENOMICS; SECONDARY STRUCTURE; SEQUENCE; DATABASE; COMMON; FOLD; CLASSIFICATION AB Advances in structural genomics and protein structure prediction require the design of automatic, fast, objective, and well benchmarked methods capable of comparing and assessing the similarity of low-resolution three-dimensional structures, via experimental or theoretical approaches. Here, a new method for sequence-independent structural alignment is presented that allows comparison of an experimental protein structure with an arbitrary low-resolution protein tertiary model. The heuristic algorithm is given and then used to show that it can describe random structural alignments of proteins with different folds with good accuracy by an extreme value distribution. From this observation, a structural similarity score between two proteins or two different conformations of the same protein is derived from the likelihood of obtaining a given structural alignment by chance. The performance of the derived score is then compared with well established, consensus manual-based scores and data sets. We found that the new approach correlates better than other tools with the gold standard provided by a human evaluator. Timings indicate that the algorithm is fast enough for routine use with large databases of protein models. Overall. our results indicate that the new program (MAMMOTH) will be a good tool for protein structure comparisons in structural genomics applications. MAMMOTH is available from our web site at http://physbio.mssni.edu/similar toortizg/. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. NYU, Mt Sinai Sch Med, Dept Physiol & Biophys, New York, NY 10029 USA. RP Ortiz, AR (reprint author), 1 Gustave Levy Pl,Box 1218, New York, NY 10029 USA. EM ortiz@inka.mssm.edu NR 69 TC 286 Z9 296 U1 0 U2 11 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD NOV PY 2002 VL 11 IS 11 BP 2606 EP 2621 DI 10.1110/ps.0215902 PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 606NG UT WOS:000178739600009 PM 12381844 ER PT J AU Ramelot, TA Cort, JR Yee, AA Semesi, A Edwards, AM Arrowsmith, CH Kennedy, MA AF Ramelot, TA Cort, JR Yee, AA Semesi, A Edwards, AM Arrowsmith, CH Kennedy, MA TI NMR structure of the Escherichia coli protein YacG: a novel sequence motif in the zinc-finger family of proteins SO PROTEINS-STRUCTURE FUNCTION AND GENETICS LA English DT Article ID ISOTOPICALLY-ENRICHED PROTEINS; RESONANCE ASSIGNMENTS; IMPROVED SENSITIVITY; SPECTRA; DOMAIN; RUBREDOXIN; GATA-1; H-1; H2O C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Toronto, Dept Med Biophys, Toronto, ON, Canada. Univ Toronto, Ontario Canc Inst, Toronto, ON, Canada. RP Kennedy, MA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999-MS K8-98, Richland, WA 99352 USA. FU NIGMS NIH HHS [P50-GM62413] NR 22 TC 10 Z9 13 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-3585 J9 PROTEINS JI Proteins PD NOV 1 PY 2002 VL 49 IS 2 BP 289 EP 293 DI 10.1002/prot.10214 PG 5 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 598HC UT WOS:000178269300013 PM 12211008 ER PT J AU Steinbring, E Faber, SM Hinkley, S Macintosh, BA Gavel, D Gates, EL Christou, JC Le Louarn, M Raschke, LM Severson, SA Rigaut, F Crampton, D Lloyd, JP Graham, JR AF Steinbring, E Faber, SM Hinkley, S Macintosh, BA Gavel, D Gates, EL Christou, JC Le Louarn, M Raschke, LM Severson, SA Rigaut, F Crampton, D Lloyd, JP Graham, JR TI Characterizing the adaptive optics off-axis point-spread function. I. A semiempirical method for use in natural guide star observations SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID FRANCE-HAWAII TELESCOPE; INFRARED CAMERA; TURBULENCE; ISOPLANATISM; PERFORMANCE; RESOLUTION; BONNETTE; QSO AB Even though the technology of adaptive optics (AO) is rapidly maturing, calibration of the resulting images remains a major challenge. The AO point-spread function (PSF) changes quickly in both time and position on the sky. In a typical observation, the star used for guiding will be separated from the scientific target by 10"-30". This is sufficient separation to render images of the guide star by themselves nearly useless in characterizing the PSF at the off-axis target position. A semiempirical technique is described that improves the determination of the AO off-axis PSF. The method uses calibration images of dense star fields to determine the change in PSF with field position. It then uses this information to correct contemporaneous images of the guide star to produce a PSF that is more accurate for both the target position and the time of a scientific observation. We report on tests of the method using natural guide star AO systems on the Canada-France-Hawaii Telescope and Lick Observatory Shane Telescope, augmented by simple atmospheric computer simulations. At 25" off-axis, predicting the PSF FWHM using only information about the guide star results in an error of 60%. Using an image of a dense star field lowers this error to 33%, and our method, which also folds in information about the on-axis PSF, further decreases the error to 19%. C1 Univ Calif Santa Cruz, Ctr Adapt Opt, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, UCO, Lick Observ, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Santa Cruz, Lick Observ, Mt Hamilton, CA 95140 USA. Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA. Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Steinbring, E (reprint author), Univ Calif Santa Cruz, Ctr Adapt Opt, Santa Cruz, CA 95064 USA. OI Steinbring, Eric/0000-0003-1259-0813 NR 23 TC 17 Z9 17 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD NOV PY 2002 VL 114 IS 801 BP 1267 EP 1280 DI 10.1086/343217 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 610QP UT WOS:000178972200011 ER PT J AU Balco, G Stone, JOH Porter, SC Caffee, MW AF Balco, G Stone, JOH Porter, SC Caffee, MW TI Cosmogenic-nuclide ages for New England coastal moraines, Martha's Vineyard and Cape Cod, Massachusetts, USA SO QUATERNARY SCIENCE REVIEWS LA English DT Article ID ICE-MARGIN AB Cosmogenic-nuclide exposure ages for 13 glacially transported boulders atop the Martha's Vineyard moraine, MA, USA, indicate that the southeastern margin of the Laurentide ice sheet reached its maximum extent during the last glaciation 23,200+/-500 yr ago. Another 10 age determinations from the younger Buzzards Bay moraine near Woods Hole, MA, indicate that this moraine complex was formed 18,800+/-400yr ago. These ages correlate approximately with the terminations of cooling cycles recorded in Greenland ice cores and coeval ice-rafting events, suggesting that the marginal position of this sector of the ice sheet was tightly coupled to North Atlantic climate during the last glacial maximum. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Washington, Quaternary Res Ctr, Seattle, WA 98195 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Balco, G (reprint author), Univ Washington, Quaternary Res Ctr, Mail Stop 351310, Seattle, WA 98195 USA. RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 29 TC 48 Z9 49 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PD NOV PY 2002 VL 21 IS 20-22 BP 2127 EP 2135 AR PII S0277-3791(02)00085-9 DI 10.1016/S0277-3791(02)00085-9 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 623TY UT WOS:000179720000001 ER PT J AU Hardison, DR Cooper, WJ Mezyk, SP Bartels, DM AF Hardison, DR Cooper, WJ Mezyk, SP Bartels, DM TI The free radical chemistry of tert-butyl formate: rate constants for hydroxyl radical, hydrated electron and hydrogen atom reaction in aqueous solution SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Pacifichem 2000 Meeting CY DEC 14-19, 2000 CL HONOLULU, HAWAII DE tert-butyl formate (TBF); methyl tert-butylether (MTBE); advanced oxidation technology (AOT); rate constraints; free radicals; aqueous electron pulse radiolysis ID PULSE-RADIOLYSIS; ETHER AB Transients generated in situ by advanced oxidation technologies (AOTs) to destroy organic contaminants in ground and drinking water often give large concentrations of chemical by-products. These by-products may have adverse health effects, and can also interfere with the desired chemical removal by competing for the generated transients, thus lowering the overall efficiency of the remediation process. To allow for a quantitative evaluation of the influence of tertbutyl formate (TBF), a major by-product formed in the AOT destruction of methyl tert-butyl ether, rate constants for TBF reaction with the hydroxyl radical, the hydrated electron and the hydrogen atom in aqueous solution were measured in this study. Absolute values of (5.23+/-0.07) x 10(8), (5.48+/-0.09) x 10(8) and (3.58+/-0.07) x 10(6) M(-1)s(-1), were determined at 22degreesC, respectively. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA. Univ N Carolina, Dept Chem, Wilmington, NC 28403 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Mezyk, SP (reprint author), Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA. NR 22 TC 18 Z9 19 U1 3 U2 11 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 NOV PY 2002 VL 65 IS 4-5 BP 309 EP 315 AR PII S0969-806X(02)00333-X DI 10.1016/S0969-806X(02)00333-X PG 7 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 618NB UT WOS:000179423200003 ER PT J AU Johnson, HD Cooper, WJ Mezyk, SP Bartels, DM AF Johnson, HD Cooper, WJ Mezyk, SP Bartels, DM TI Free radical reactions of monochloramine and hydroxylamine in aqueous solution SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Pacifichem 2000 Meeting CY DEC 14-19, 2000 CL HONOLULU, HAWAII DE monochloramine; hydroxylamine; advanced oxidation technology (AOT); rate constants; free radicals; aqueous electron pulse radiolysis ID DRINKING-WATER; ELECTRON RADIOLYSIS; HYDRATED ELECTRONS; PULSE-RADIOLYSIS; REEVALUATION; OXIDATION; HYDROGEN; PRODUCTS; AMINO; ACID AB The use of Advanced Oxidation Technologies to destroy organic contaminants in drinking water may be impacted by the presence of disinfection chemicals such as monochloramine (NH2Cl). To allow a quantitative evaluation of the effect of NH2Cl on the destruction of organics in water rate constants for its reaction with the hydrated electron, the hydroxyl radical and the hydrogen atom were determined in this study. The corresponding values of (2.2+/-0.2) x 10(10), (2.8+/-0.2) x 10(9), and (1.2+/-0.1) x 10(9) M(-1)s(-1), respectively, were incorporated into a kinetic computer model whose predictions were in good agreement with experimental chloramine removal under large scale, steady-state electron-beam irradiation conditions. Rate constants were also determined for the reaction of the hydroxyl radical and hydrogen atom with the chloramine hydration product hydroxylamine to supplement established literature data. Hydroxyl radical rate constants for the basic (NH2OH) and acidic (NH3OH+) forms were determined as (8.5+/-0.4) x 10(9) and less than or equal to5 x 10(7) M(-1)s(-1), respectively, while for hydrogen atom reaction, corresponding rate constants of (4.5+/-0.1) x 10(7) and (3.6+/-1.5) x 10(5) M(-1)s(-1) were found. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA. Univ N Carolina, Dept Chem, Wilmington, NC 28403 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Mezyk, SP (reprint author), Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA. NR 43 TC 24 Z9 25 U1 3 U2 13 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 NOV PY 2002 VL 65 IS 4-5 BP 317 EP 326 AR PII S0969-806X(02)00332-8 DI 10.1016/S0969-806X(02)00332-8 PG 10 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 618NB UT WOS:000179423200004 ER PT J AU Williams, JA Cooper, WJ Mezyk, SP Bartels, DM AF Williams, JA Cooper, WJ Mezyk, SP Bartels, DM TI Absolute rate constants for the reaction of the hydrated electron, hydroxyl radical and hydrogen atom with chloroacetones in water SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Pacifichem 2000 Meeting CY DEC 14-19, 2000 CL HONOLULU, HI SP Amer Chem Soc DE chloroacetones; disinfection by products (DBP); advanced oxidation technology (AOT); rate constants; free radicals; aqueous electron pulse radiolysis ID DISINFECTION BY-PRODUCTS; AQUEOUS-SOLUTION; PULSE-RADIOLYSIS; DRINKING-WATER; IDENTIFICATION; REEVALUATION; DEGRADATION AB Bimolecular rate constants for chloroacetone (CAce), 1,1-dichloroacetone (1,1-1DCAce) and 1,1,1-trichloroacetone (1,1,1-TCAce) reaction with the aqueous electron (e(aq)(-)), the hydroxyl radical ((OH)-O-.), and the hydrogen atom (H-.) have been measured using electron pulse radiolysis in Combination with transient absorption spectroscopy (e(aq)(-), (OH)-O-.), and electron paramagnetic resonance detection (H-.). The measured rate constants with each substrate, in M(-1)s(-1) for e(aq)(-), (OH)-O-. and H-. reaction, are: CAce: (1.34+/-0.15) x 10(10), (1.69+/-0.05) x 10(8), (2.63+/-0.07) x 10(7); 1,1-DCAce: (1.22+/-0.12) x 10(10), (8.8+/-0.4) x 10(7), (2.9+/-0.3) x 10(7); and 1,1,1-TCAce: (1.56+/-0.17) x 10(10), (3.3+/-0.1) x 10(7), (2.8+/-0.2) x 10(7), respectively. The trends observed in these rate constants are discussed in terms of the initial reaction mechanisms of the three reactive species with these chloroacetones. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA. Univ N Carolina, Dept Chem, Wilmington, NC 28403 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA. EM smezyk@csulb.edu NR 34 TC 11 Z9 12 U1 3 U2 9 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 NOV PY 2002 VL 65 IS 4-5 BP 327 EP 334 AR PII S0969-806X(02)00351-1 DI 10.1016/S0969-806X(02)00351-1 PG 8 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 618NB UT WOS:000179423200005 ER PT J AU Mincher, BJ Brey, RR Rodriguez, RG Pristupa, S Ruhter, A AF Mincher, BJ Brey, RR Rodriguez, RG Pristupa, S Ruhter, A TI Increasing PCB radiolysis rates in transformer oil SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Pacifichem 2000 Meeting CY DEC 14-19, 2000 CL HONOLULU, HAWAII DE polychlorinated biphenyls; electron beam; radiolysis; dose constant ID GAMMA-RAY DESTRUCTION; POLYCHLORINATED-BIPHENYLS; INDUCED DEGRADATION; IONIZING-RADIATION; DECHLORINATION; 2-PROPANOL AB The kinetics of Aroclor 1242 radiolysis in transformer oil, using high-energy electrons, was found to be analogous to that previously measured for individual polychlorinated biphenyl (PCB) congeners irradiated with gamma-rays. The plot of the pseudo-first-order rate constant for PCB decomposition versus initial PCB concentration is a power function, with high rate constants for low concentrations. The addition of alkaline isopropanol to transformer oil was found to increase the pseudo-first-order rate constant for PCB decomposition. The rate constant under these conditions is independent of concentration. This may be explained by the establishment of chain reaction dechlorination in the oil. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Idaho State Univ, Idaho Accelerator Ctr, Pocatello, ID 83209 USA. RP Mincher, BJ (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. RI Mincher, Bruce/C-7758-2017 NR 12 TC 24 Z9 25 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 NOV PY 2002 VL 65 IS 4-5 BP 461 EP 465 AR PII S0969-806X(02)00361-4 DI 10.1016/S0969-806X(02)00361-4 PG 5 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 618NB UT WOS:000179423200021 ER PT J AU Nickelsen, MG Cooper, WJ Secker, DA Rosocha, LA Kurucz, CN Waite, TD AF Nickelsen, MG Cooper, WJ Secker, DA Rosocha, LA Kurucz, CN Waite, TD TI Kinetic modeling and simulation of PCE and TCE removal in aqueous solutions by electron-beam irradiation SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Pacifichem 2000 Meeting CY DEC 14-19, 2000 CL HONOLULU, HAWAII DE trichloroethylene; tetrachloroethylene; electron beam; steady state and computer-based kinetic modeling ID RADIATION-INDUCED DECOMPOSITION; DRINKING-WATER; TRICHLOROETHYLENE; TETRACHLOROETHYLENE; PERCHLOROETHYLENE; DEGRADATION AB The irradiation of aqueous solutions of TCE and PCE using a high-energy electron-beam results in the rapid decomposition of both chemicals. It is known that both TCE and PCE react with the aqueous electron and the hydroxyl radical with bimolecular rate constants greater than 10(9) M-1 s(-1) for each reaction. The fact that high-energy electrons produce significant concentrations of both e(aq)(-) and .OH radicals in water makes it an effective process for the removal of TCE and PCE from aqueous solution. We have employed steady state and computer-based chemical kinetic models to simulate and better understand the chemistry and kinetics of e-beam irradiation when applied to natural water systems. Model results were benchmarked to experimental data, allowing for the optimization of the reaction of DOC with the .OH radical. Values for the associated second-order reaction rate constant were found to be 2.5 x 10(8) and 4.0 x 10(8) M-1 s(-1), consistent with reported values for k(OH,DOC). The models were also used to investigate the possibility of incomplete irradiation during treatment and the presence of proposed chemical reactions of by-products. The reactions involve radicals and radical-adduct species formed by the reaction of TCE and PCE with the hydroxyl radical. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ N Carolina, Dept Chem, Wilmington, NC 28403 USA. Los Alamos Natl Lab, Grp CST18, Los Alamos, NM 87545 USA. Univ Miami, Dept Management Sci & Ind Engn, Coral Gables, FL 33124 USA. Univ Miami, Dept Civil & Architectural Engn, Coral Gables, FL 33124 USA. RP Nickelsen, MG (reprint author), Univ N Carolina, Dept Chem, 601 S Coll Rd, Wilmington, NC 28403 USA. NR 22 TC 16 Z9 17 U1 1 U2 5 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 NOV PY 2002 VL 65 IS 4-5 BP 579 EP 587 AR PII S0969-806X(02)00362-6 DI 10.1016/S0969-806X(02)00362-6 PG 9 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 618NB UT WOS:000179423200037 ER PT J AU Holley, WR Mian, IS Park, SJ Rydberg, B Chatterjee, A AF Holley, WR Mian, IS Park, SJ Rydberg, B Chatterjee, A TI A model for interphase chromosomes and evaluation of radiation-induced aberrations SO RADIATION RESEARCH LA English DT Article ID DOUBLE-STRAND BREAKS; HEAVY-PARTICLE TRACKS; IN-SITU HYBRIDIZATION; IONIZING-RADIATION; HUMAN-LYMPHOCYTES; GAMMA-RADIATION; X-RAYS; DNA; CELLS; CHROMATIN AB We have developed a theoretical model for evaluating radiation-induced chromosomal exchanges by explicitly taking into account interphase (G(0)/G(1)) chromosome structure, nuclear organization of chromosomes, the production of double-strand breaks (DSBs), and the subsequent rejoinings in a faithful or unfaithful manner. Each of the 46 chromosomes for human lymphocytes (40 chromosomes for mouse lymphocytes) is modeled as a random polymer inside a spherical volume. The chromosome spheres are packed randomly inside a spherical nucleus with an allowed overlap controlled by a parameter Omega. The rejoining of DSBs is determined by a Monte Carlo procedure using a Gaussian proximity function with an interaction range parameter sigma. Values of Omega and sigma have been found which yield calculated results of interchromosomal aberration frequencies that agree with a wide range of experimental data. Our preferred solution is one with an interaction range of 0.5 mum coupled with a relatively small overlap parameter of 0.675 mum, which more or less confirms previous estimates. We have used our model with these parameter values and with resolution or detectability limits to calculate yields of translocations and dicentrics for human lymphocytes exposed to low-LET radiation that agree with experiments in the dose range 0.09 to 4 Gy. Five different experimental data sets have been compared with the theoretical results. Essentially all of the experimental data fall between theoretical curves corresponding to resolution limits of 1 Mbp and 20 Mbp, which may reflect the fact that different investigators use different limits for sensitivity or detectability. Translocation yields for mouse lymphocytes have also been calculated and are in good agreement with experimental data from I cGy to 10 cGy. There is also good agreement with recent data on complex aberrations. Our model is expected to be applicable to both low- and high-LET radiation, and we include a sample prediction of the yield of interchromosomal rejoining in the dose range 0.22 Gy to 2 Gy of 1000 MeV/nucleon iron particles. This dose range corresponds to average particle traversals per nucleus ranging from 1.0 to 9.12. (C) 2002 by Radiation Research Society. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Chatterjee, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Bldg 74,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 58 TC 37 Z9 38 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 820 JORIE BOULEVARD, OAK BROOK, IL 60523 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD NOV PY 2002 VL 158 IS 5 BP 568 EP 580 DI 10.1667/0033-7587(2002)158[0568:AMFICA]2.0.CO;2 PG 13 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 612RR UT WOS:000179089700003 PM 12385634 ER PT J AU Morris, DG Humpherson, PG Leese, HJ Sreenan, JM AF Morris, DG Humpherson, PG Leese, HJ Sreenan, JM TI Amino acid turnover by elongating cattle blastocysts recovered on days 14-16 after insemination SO REPRODUCTION LA English DT Article ID PREIMPLANTATION EMBRYO DEVELOPMENT; STAGE BOVINE EMBRYOS; IN-VITRO; PROTEIN-SYNTHESIS; NITRIC-OXIDE; CULTURE; METABOLISM; REQUIREMENTS; REGULATOR; GLUTAMINE AB Blastocyst elongation from day 14 to day 16 after insemination coincides with a major phase of embryo loss in cattle. Protein synthesis, reflected in protein content, increases markedly over this period but little is known about the amino acid requirement of elongating blastocysts at this time. Cattle blastocysts produced in vivo were recovered on days 14-16 after insemination and cultured individually for up to 8 h in synthetic oviduct fluid containing a physiological mixture of amino acids plus 1 mmol glutamine l(-1) and 0.1 % (w/v) polyvinyl alcohol (SOFaaPVA). After 1, 4 and 8 h in culture, an aliquot of culture medium was removed and the rate of amino acid depletion or production was calculated per unit of protein and per hour of cultured Amino acids were depleted or produced at different rates. Arginine was depleted from the medium at a significant rate (P < 0.05) during all culture periods. Alanine and glutamate were produced at a significant rate (P < 0.05) during all culture periods. The rate of alanine production was significantly greater (P < 0.05) in blastocysts recovered on day 14 compared with days 15 or 16 after insemination. Alanine production and arginine depletion tended to be greater in smaller embryos recovered on day 14 compared with larger and later stage embryos, indicating that earlier stage embryos may have higher metabolic activity than later stage embryos. Qualitatively, the pattern of amino acid consumption and production during elongation was similar to that shown from the zygote to early blastocyst stage. C1 TEAGASC, Agr & Food Dev Author, Anim Reprod Dept, Athenry, Co Galway, Ireland. Univ York, Dept Biol, York YO10 5YW, N Yorkshire, England. RP Morris, DG (reprint author), TEAGASC, Agr & Food Dev Author, Anim Reprod Dept, Athenry, Co Galway, Ireland. EM dmorris@athenry.teagasc.ie RI MORRIS, DERMOT/J-8646-2013 NR 38 TC 8 Z9 8 U1 0 U2 0 PU BIOSCIENTIFICA LTD PI BRISTOL PA EURO HOUSE, 22 APEX COURT WOODLANDS, BRADLEY STOKE, BRISTOL BS32 4JT, ENGLAND SN 1470-1626 J9 REPRODUCTION JI Reproduction PD NOV PY 2002 VL 124 IS 5 BP 667 EP 673 PG 7 WC Developmental Biology; Reproductive Biology SC Developmental Biology; Reproductive Biology GA 617YY UT WOS:000179389700009 PM 12417005 ER PT J AU Utter, SB Lopez-Urrutia, JRC Beiersdorfer, P Trabert, E AF Utter, SB Lopez-Urrutia, JRC Beiersdorfer, P Trabert, E TI Design and implementation of a high-resolution, high-efficiency optical spectrometer SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID BEAM ION-TRAP; X-RAY SPECTROMETER; MAGNETIC DIPOLE TRANSITIONS; ELECTRON-BEAM; ISOELECTRONIC SEQUENCE; FORBIDDEN LINES; CHARGED IONS; SPECTROSCOPY; SPECTRA; BARIUM AB We present the design, implementation and testing of a high-efficiency, high-resolution transmission grating spectrometer for measurements of near-ultraviolet to visible-range spectra of light from an electron beam ion trap, where geometry is constrained. The system consists of two 5 in. diameter f/4.6 achromatic lenses, a 6 in. diameter transmission grating ion-beam etched in fused silica, and a thinned, backilluminated CCD detector. The simple design minimizes the number of optical components, each with optimal throughput and high efficiency. Using a 30 mum wide entrance slit, a resolving power (lambda/Deltalambda) of 15 400 at lambdaapproximate to3850 Angstrom has been demonstrated. The features and limitations of the instrument have been explored and an in situ calibration technique for use on the Livermore EBIT-II and SuperEBIT electron beam ion traps has been developed. (C) 2002 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Utter, SB (reprint author), Spectra Phys, Mountain View, CA 94039 USA. RI Crespo Lopez-Urrutia, Jose R./F-7069-2011 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037 NR 36 TC 19 Z9 21 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2002 VL 73 IS 11 BP 3737 EP 3741 DI 10.1063/1.1510574 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 607YK UT WOS:000178818200002 ER PT J AU Durakiewicz, T Arko, A Joyce, JJ Moore, DP Graham, K AF Durakiewicz, T Arko, A Joyce, JJ Moore, DP Graham, K TI He discharge lamp for photoemission experiments with radioactive materials SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID PLASMA LIGHT-SOURCE; PHOTOELECTRON-SPECTROSCOPY AB A simple He discharge lamp is described. The lamp is designed specially for photoemission measurements performed on radioactive materials, mainly Pu and Pu compounds. The lamp construction allows easy single-use assembly/disassembly of the discharge tube with minimum risk of radiological contamination, minimum amount of waste generated, air cooling capability, very good He II/He I ratio at low He pressures, and stable operation for at least 200 h. Thanks to the high brightness in the He II range we were able to observe the He IIbeta, He IIgamma, and even He IIepsilon features in the PuIn3 photoemission spectrum. Total cost of parts used to produce the discharge tube is less than $300, so that the cost of operation is less than $1.5/h. (C) 2002 American Institute of Physics. C1 Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. Marie Curie Sklodowska Univ, Inst Phys, PL-20031 Lublin, Poland. RP Durakiewicz, T (reprint author), Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Mailstop K764, Los Alamos, NM 87545 USA. OI Durakiewicz, Tomasz/0000-0002-1980-1874 NR 7 TC 7 Z9 7 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2002 VL 73 IS 11 BP 3750 EP 3753 DI 10.1063/1.1510551 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 607YK UT WOS:000178818200005 ER PT J AU Carlsten, BE AF Carlsten, BE TI Deconvolving long-pulse electron-beam centroid data from resistive wall-current monitors SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ACCELERATOR AB A technique is described to deconvolve long-pulse electron-beam centroid data from resistive wall-current monitors. These monitors are typically capable of accurately measuring total current for tens of microseconds, but, due to magnetic diffusion, tend to give direct centroid measurements only up to hundreds of nanoseconds. As a result, resistive wall-current monitors are usually not considered reliable for long-pulse operation. However, the voltage signals azimuthally around the monitor still contains that information, and the information can be easily deconvolved by differentiating the signals. In this article, the diffusive part of Maxwell's equations is used to find an expression for the time response of a resistive wall-current monitor for a beam of arbitrary current and centroid evolution. A simple way of inverting this response is shown to find the beam centroid as a function of time within the electron pulse. (C) 2002 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Carlsten, BE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2002 VL 73 IS 11 BP 3772 EP 3777 DI 10.1063/1.1515763 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 607YK UT WOS:000178818200010 ER PT J AU Huang, DJ Wu, WP Chen, J Chang, CF Chung, SC Yuri, M Lin, HJ Johnson, PD Chen, CT AF Huang, DJ Wu, WP Chen, J Chang, CF Chung, SC Yuri, M Lin, HJ Johnson, PD Chen, CT TI Performance of a Mott detector for undulator-based spin-resolved spectroscopy SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID POLARIZED ELECTRON-SPECTROSCOPY; ZHANG-RICE SINGLETS; PHOTOEMISSION; COMPACT; POLARIMETER; ANALYZER; SPECTROMETER; FERROMAGNETS AB To measure spin-polarized core-level electron spectra, a spectrometer equipped with a highly efficient retarding-potential Mott spin polarimeter using undulator-based soft-x-ray beamlines has been set up. With a thin film of Au as a target this polarimeter has an efficiency estimated to be similar to2x10(-4). The performance of this system for spin-polarized spectroscopy has been tested using core-level spin-polarized photoemission of magnetic and nonmagnetic thin films excited with linearly and circularly polarized light, respectively. Measurements using a new spin-resolved absorption technique are also discussed. (C) 2002 American Institute of Physics. C1 Synchrotron Radiat Res Ctr, Hsinchu 300, Taiwan. Natl Chiao Tung Univ, Dept Electrophys, Hsinchu 300, Taiwan. Natl Chung Cheng Univ, Dept Phys, Chiayi 621, Taiwan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Huang, DJ (reprint author), Synchrotron Radiat Res Ctr, Hsinchu 300, Taiwan. RI Chang, Chun-Fu/B-7805-2012 OI Chang, Chun-Fu/0000-0003-1803-2468 NR 37 TC 12 Z9 13 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2002 VL 73 IS 11 BP 3778 EP 3783 DI 10.1063/1.1510552 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 607YK UT WOS:000178818200011 ER PT J AU Baker, KL Brase, J Kartz, M Olivier, SS Sawvel, B Tucker, J AF Baker, KL Brase, J Kartz, M Olivier, SS Sawvel, B Tucker, J TI The use of a Shack-Hartmann wave front sensor for electron density characterization of high density plasmas SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ADAPTIVE OPTICS; LASER AB This article examines the use of a Shack-Hartmann wave front sensor to accurately measure the line-integrated electron density gradient formed in laser-produced and Z-pinch plasma experiments. The minimum discernable line-integrated density gradient is derived for the Shack-Hartmann wave front sensor, as well as its range of applicability. A laboratory comparison between a Shack-Hartmann wave front sensor and a Twyman-Green interferometer is also presented. For this comparison, a liquid-crystal spatial-light modulator is used to introduce a spatially varying phase onto both of the wave front sensors, simulating a phase profile that could occur when a probe passes through a plasma. The phase change measured by the Shack-Hartmann sensor is then compared directly with the Twyman-Green interferometer. In this article, the merits associated with the use of a Shack-Hartmann sensor are discussed. These include a wide dynamic range, high optical efficiency, broadband or low coherence length light capability, experimental simplicity, two-dimensional gradient determination, and multiplexing capability. (C) 2002 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Baker, KL (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 15 TC 11 Z9 11 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2002 VL 73 IS 11 BP 3784 EP 3788 DI 10.1063/1.1510546 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 607YK UT WOS:000178818200012 ER PT J AU Stoeckl, C Glebov, VY Zuegel, JD Meyerhofer, DD Lerche, RA AF Stoeckl, C Glebov, VY Zuegel, JD Meyerhofer, DD Lerche, RA TI Wide-dynamic-range "neutron bang time" detector on OMEGA SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A simple, low-cost "neutron bang time" detector has been implemented on the OMEGA laser system to measure the average time of neutron emission from inertial confinement fusion targets. This detector uses fast plastic scintillators coupled to photomultiplier tubes. A fast digital real-time oscilloscope records the signals. Absolute timing accuracies of better than 100 ps are achieved over a wide dynamic range (10(7) 2(+)) using novel CoulombExcitation techniques are presented for even-even isotopes of Ge and Se. The difficulties and challenges that represent the determination of the B(E2) values for the exotic neutron-rich nuclei Ge-78 and Ge-80 are discussed. The measurement of these radioactive isotopes was possible thanks to the recent availability of radioactive ion beams at the Holifield Radioactive Ion Beam Facility. A comparison between the measured B(E2) values and theoretical predictions obtained with the IBA2 model is also presented. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Padilla, E (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI radford, David/A-3928-2015 NR 29 TC 2 Z9 2 U1 0 U2 1 PU SOC MEXICANA FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD NOV PY 2002 VL 48 SU 2 BP 93 EP 97 PG 5 WC Physics, Multidisciplinary SC Physics GA 621DT UT WOS:000179573800016 ER PT J AU Chavez, E Barron, L Beene, JR Uribarri, AG del Campo, JG Gross, CJ Halbert, ML de la P, LH Huerta, A Ibanes, A Liang, JF Macias, R Moreno, E Murillo, G Ortiz, ME Paul, SD Policroniades, R Stracener, DW Shapira, D Varela, A Varner, RL AF Chavez, E Barron, L Beene, JR Uribarri, AG del Campo, JG Gross, CJ Halbert, ML de la P, LH Huerta, A Ibanes, A Liang, JF Macias, R Moreno, E Murillo, G Ortiz, ME Paul, SD Policroniades, R Stracener, DW Shapira, D Varela, A Varner, RL TI The simultaneous emission of two nucleons, an understanding and new predictions SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 25th Symposium on Nuclear Physics CY JAN 02-07, 2002 CL TAXCO, MEXICO SP Div Fis Nucl Soc Mexicana Fis, Inst Ciencias Nucl, Inst Fis, Ctr Latinoamer Fis DE two proton emission; simultaneity ID 2-PROTON EMISSION; RESONANCE; DECAY; STATE; NE-18 AB After a long standing search of over 40 years [1], the simultaneous emission of two protons was discovered [2, 3]. An excited state. in a light nuclei (Ne-18), not a ground state, was identified as the first state to have such decay property. In this work, we review that discovery, discuss the concept of simultaneity and propose a simple analysis in terms of the shell structure of the nuclei involved. The analysis is generalized to all closed shells up to Ca-48. It is predicted that no other nuclear state near closed shells, can decay by a pure simultaneous emission of two protons. The same analysis applied to the case of the simultaneous emission of two neutrons yielded the prediction of two sets of states in C-14 and O-18 with such property. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Inst Nacl Invest Nucl, Dept Acelerador, Salazar 52045, Edo Mexico, Mexico. RP Chavez, E (reprint author), Univ Nacl Autonoma Mexico, Inst Fis, POB 20-364,Del A Obregon, Mexico City 01000, DF, Mexico. NR 15 TC 3 Z9 3 U1 0 U2 1 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD NOV PY 2002 VL 48 SU 2 BP 98 EP 102 PG 5 WC Physics, Multidisciplinary SC Physics GA 621DT UT WOS:000179573800017 ER PT J AU Sanchez, MCD AF Sanchez, MCD TI Hadron spectra from Au plus Au collisions at RHIC SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 25th Symposium on Nuclear Physics CY JAN 02-07, 2002 CL TAXCO, MEXICO SP Div Fis Nucl Soc Mexicana Fis, Inst Ciencias Nucl, Inst Fis, Ctr Latinoamer Fis DE momentum distributions; relativistic heavy-ion collisions ID NUCLEUS-NUCLEUS COLLISIONS; DISTRIBUTIONS; ENERGIES; QUARK AB The STAR detector at RHIC allows the study of transverse momentum and rapidity distribution of charged particles produced in high energy heavy ion collisions. Results on charged hadrons and identified pions in Au+Au collisions will be presented. These observables help to map the global characteristics of heavy ion collisions. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Sanchez, MCD (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD NOV PY 2002 VL 48 SU 2 BP 117 EP 122 PG 6 WC Physics, Multidisciplinary SC Physics GA 621DT UT WOS:000179573800020 ER PT J AU Bentley, MA Williams, SJ Joss, DT O'Leary, CD Bruce, AM Frankland, L Cameron, JA Svensson, CE Carpenter, MP Lister, CJ Reiter, R Seweryniak, D Fallon, P Gelletly, W Regan, PH Martinez-Pinedo, G Poves, A Solano, JS Rubio, B Warner, DD AF Bentley, MA Williams, SJ Joss, DT O'Leary, CD Bruce, AM Frankland, L Cameron, JA Svensson, CE Carpenter, MP Lister, CJ Reiter, R Seweryniak, D Fallon, P Gelletly, W Regan, PH Martinez-Pinedo, G Poves, A Solano, JS Rubio, B Warner, DD TI Mirror symmetry and coulomb energies at high angular momentum SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 25th Symposium on Nuclear Physics CY JAN 02-07, 2002 CL TAXCO, MEXICO SP Div Fis Nucl Soc Mexicana Fis, Inst Ciencias Nucl, Inst Fis, Ctr Latinoamer Fis DE isobaric multiplets; shell model; Coulomb energies ID HIGH-SPIN; NUCLEI; SHELL; CR-49; MN-49 AB In this presentation, some latest results from gamma-ray spectroscopic studies of high spin states of isobaric multiplets will be presented. An experimental programme is underway to examine exited states of isobaric multiplets of total isospin T = 1/2 and T = 1 and the comparison of energies of excited states can be interpreted in terms of Coulomb effects. Through a systematic study of these Coulomb effects, and through examination of the calculated Coulomb energies from full p f-shell model calculations, it is now becoming clear that measurement of Coulomb energies can yield very detailed information on the evolution of nuclear structure phenomena as a function of energy and angular momentum. In this contribution, latest results of studies of isobaric analogue states at high spin in the A = 50, 51 and 53 systems will be presented. C1 Univ Keele, Sch Chem & Phys, Keele ST5 5BG, Staffs, England. Univ York, Dept Phys, York YO10 5DD, N Yorkshire, England. Univ Brighton, Sch Engn, Brighton BN2 4GJ, E Sussex, England. McMaster Univ, Hamilton, ON L8S 4K1, Canada. Argonne Natl Lab, Argonne, IL 60439 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Surrey, Sch Phys & Chem, Guildford GU2 7XH, Surrey, England. Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain. Univ Valencia, CSIC, E-46071 Valencia, Spain. CLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. RP Univ Keele, Sch Chem & Phys, Keele ST5 5BG, Staffs, England. RI Martinez-Pinedo, Gabriel/A-1915-2013; Rubio, Berta/M-1060-2014; Carpenter, Michael/E-4287-2015 OI Bruce, Alison/0000-0003-2871-0517; Martinez-Pinedo, Gabriel/0000-0002-3825-0131; Rubio, Berta/0000-0002-9149-4151; Carpenter, Michael/0000-0002-3237-5734 NR 17 TC 0 Z9 0 U1 0 U2 1 PU SOC MEXICANA FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD NOV PY 2002 VL 48 SU 2 BP 123 EP 128 PG 6 WC Physics, Multidisciplinary SC Physics GA 621DT UT WOS:000179573800021 ER PT J AU Hoffert, MI Caldeira, K Benford, G Criswell, DR Green, C Herzog, H Jain, AK Kheshgi, HS Lackner, KS Lewis, JS Lightfoot, HD Manheimer, W Mankins, JC Mauel, ME Perkins, LJ Schlesinger, ME Volk, T Wigley, TML AF Hoffert, MI Caldeira, K Benford, G Criswell, DR Green, C Herzog, H Jain, AK Kheshgi, HS Lackner, KS Lewis, JS Lightfoot, HD Manheimer, W Mankins, JC Mauel, ME Perkins, LJ Schlesinger, ME Volk, T Wigley, TML TI Advanced technology paths to global climate stability: Energy for a greenhouse planet SO SCIENCE LA English DT Review ID SPACE SOLAR POWER; CARBON-DIOXIDE; DISPOSAL; FUTURE; FUSION; STABILIZATION; EMISSIONS; SYSTEMS; FUELS AB Stabilizing the carbon dioxide induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (similar to10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development. C1 NYU, Dept Phys, New York, NY 10003 USA. NYU, Dept Biol, New York, NY 10003 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Univ Houston, Inst Space Syst Operat, Houston, TX 77204 USA. McGill Univ, Dept Econ, Montreal, PQ H3A 2T7, Canada. MIT, Lab Energy & Environm, Cambridge, MA 02139 USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. Exxon Mobil Res & Engn Co, Annandale, NJ 08801 USA. Columbia Univ, Dept Earth & Environm Engn, New York, NY 10027 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. McGill Univ, Ctr Climate & Global Change Res, Montreal, PQ H3A 2K6, Canada. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA Headquarters, Washington, DC 20546 USA. RP Hoffert, MI (reprint author), NYU, Dept Phys, 4 Washington Pl, New York, NY 10003 USA. RI Wigley, Tom/B-4705-2008; Caldeira, Ken/E-7914-2011; Jain, Atul/D-2851-2016 OI Jain, Atul/0000-0002-4051-3228 NR 80 TC 592 Z9 607 U1 53 U2 356 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 NOV 1 PY 2002 VL 298 IS 5595 BP 981 EP 987 DI 10.1126/science.1072357 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 609XQ UT WOS:000178932000044 PM 12411695 ER PT J AU Dinsmore, AD Hsu, MF Nikolaides, MG Marquez, M Bausch, AR Weitz, DA AF Dinsmore, AD Hsu, MF Nikolaides, MG Marquez, M Bausch, AR Weitz, DA TI Colloidosomes: Selectively permeable capsules composed of colloidal particles SO SCIENCE LA English DT Article ID EMULSION DROPLETS; LATEX-PARTICLES; HOLLOW SPHERES; CELLS; ENCAPSULATION; INTERFACES; TEMPLATES; MICROENCAPSULATION; ENDOSTATIN AB We present an approach to fabricate solid capsules with precise control of size, permeability, mechanical strength, and compatibility. The capsules are fabricated by the self-assembly of colloidal particles onto the interface of emulsion droplets. After the particles are locked together to form elastic shells, the emulsion droplets are transferred to a fresh continuous-phase fluid that is the same as that inside the droplets. The resultant structures, which we call "colloidosomes", are hollow, elastic shells whose permeability and elasticity can be precisely controlled. The generality and robustness of these structures and their potential for cellular immunoisolation are demonstrated by the use of a variety of solvents, particles, and contents. C1 Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Harvard Univ, DEAS, Cambridge, MA 02138 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Kraft Foods R&D, Nanotechnol Lab, Glenview, IL 60025 USA. RP Dinsmore, AD (reprint author), Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. NR 38 TC 1310 Z9 1326 U1 53 U2 506 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 NOV 1 PY 2002 VL 298 IS 5595 BP 1006 EP 1009 DI 10.1126/science.1074868 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 609XQ UT WOS:000178932000050 PM 12411700 ER PT J AU Kaibyshev, R Musin, F Gromov, D Nieh, TG Lesuer, DR AF Kaibyshev, R Musin, F Gromov, D Nieh, TG Lesuer, DR TI Effect of liquid phase on superplastic behavior of a modified 6061 aluminum alloy SO SCRIPTA MATERIALIA LA English DT Article DE aluminium alloys; high temperature mechanical properties; differential thermal analysis; incipient melting ID TENSILE ELONGATION; COMPOSITES AB It is shown that a 0.15%Zr + 0.7%Cu-modified 6061 aluminum alloy with an initial grain size of about 11 mum exhibits a maximum elongation-to-failure of 1300% at 590 degreesC and an initial strain rate of 2.8 x 10(-4) s(-1) in a partially melted state. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Inst Met Superplast Problems, Ufa 450001, Russia. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kaibyshev, R (reprint author), Inst Met Superplast Problems, Khalturina 39, Ufa 450001, Russia. RI Nieh, Tai-Gang/G-5912-2011; Kaibyshev, Rustam/G-8804-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746; NR 10 TC 13 Z9 17 U1 1 U2 2 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 NOV 1 PY 2002 VL 47 IS 9 BP 569 EP 575 AR PII S1359-6462(02)00169-0 DI 10.1016/S1359-6462(02)00169-0 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 613QC UT WOS:000179142100001 ER PT J AU Smith, JL Halvorson, JJ Bolton, H AF Smith, JL Halvorson, JJ Bolton, H TI Soil properties and microbial activity across a 500 m elevation gradient in a semi-arid environment SO SOIL BIOLOGY & BIOCHEMISTRY LA English DT Article DE microbial activity; soil nutrients; biomass; global change ID SHRUB-STEPPE ECOSYSTEM; CLIMATIC-CHANGE; MINERALIZATION; NITROGEN; BIOMASS; FORESTS; WASHINGTON; HISTORIES; TRANSECT; DESERT AB If climate change causes the semi-arid shrub-steppe to become hotter and,drier it may affect soil C and N cycling and precipitate changes in soil processes and microbial and plant community structure. This study was conducted, using an elevation gradient as an analog of climate change, to analyze climatic influence on soil microbial activity and soil properties. We collected soil from under cryptogamic crust and bunchgrass plants at 25 sites over a 500 m elevation transect in a shrub-steppe ecosystem located in eastern Washington State of the US. The samples were analyzed for several chemical and microbiological attributes including pH, microbial biomass and nitrification potential and the data grouped into five climate sites for statistical analysis. Soil pH decreased over the transect with higher pH values in the grass soil than the crust. In contrast soil electrical conductivity (EC) increased with increasing elevation as did both ammonium and nitrate. Ammonium and EC were greater in the crust soil than the grass soil but nitrate concentration was the same under both plant covers. Both total C and N amounts increased with elevation as did nitrification potential. Due to high sample spatial variability microbial biomass, respiration and N mineralization showed non-significant trends over the 500 m elevation transect. Using these measured gradient relationships the increase in temperature and decrease in precipitation that is expected in this shrub-steppe ecosystem over the next 100 years would eventually cause the pH to increase and the EC to decrease. Plants would become more sparse, nitrification potential would decrease and ammonium would increase. Total C, N and microbial biomass concentrations would begin decreasing and may shift the controlling factors of the ecosystem to abiotic factors. The changes in the cycling of N and to some extent C due to climate change could alter the microbial and plant community structure and function of this ecosystem and cause it to move in the direction of desertification. Published by Elsevier Science Ltd. C1 Washington State Univ, USDA ARS, Pullman, WA 99164 USA. USDA ARS, Beaver, WV 25813 USA. Pacific NW Natl Lab, Environm Microbiol Grp, Richland, WA 99352 USA. RP Smith, JL (reprint author), Washington State Univ, USDA ARS, 215 Johnson Hall, Pullman, WA 99164 USA. RI Bolton, Harvey/E-5583-2011 NR 39 TC 61 Z9 76 U1 4 U2 42 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 NOV PY 2002 VL 34 IS 11 BP 1749 EP 1757 AR PII S0038-0717(02)00162-1 DI 10.1016/S0038-0717(02)00162-1 PG 9 WC Soil Science SC Agriculture GA 628LP UT WOS:000179996900024 ER PT J AU West, TO Post, WM AF West, TO Post, WM TI Soil organic carbon sequestration rates by tillage and crop rotation: A global data analysis SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Review ID LONG-TERM TILLAGE; NORTHERN GREAT-PLAINS; THIN BLACK CHERNOZEM; NORFOLK LOAMY SAND; NITROGEN-FERTILIZATION; CONSERVATION TILLAGE; MICROBIAL BIOMASS; NO-TILLAGE; SILT LOAM; SOUTHWESTERN SASKATCHEWAN AB Changes agricultural management can potentially increase the accumulation rate of soil organic C (SOC), thereby sequestering CO2 from the atmosphere. This study was conducted to quantify potential soil C sequestration rates for different crops in response to decreasing tillage intensity or enhancing rotation complexity, and to estimate the duration of time over which sequestration may occur. Analyses of C sequestration rates were completed using a global database of 67 long-term agricultural experiments, consisting of 276 paired treatments. Results indicate, on average, that a change from conventional tillage (CT) to no-till (NT) can sequester 57 +/- 14 g C m(-2) yr(-1), excluding wheat (Triticum aestivum L.)-fallow systems which may not result in SOC accumulation with a change from CT to NT. Enhancing rotation complexity can sequester an average 20 +/- 12 g C m(-2) yr(-1), excluding a change from continuous corn (Zea mays L.) to corn-soybean (Glycine mar L.) which may not result in a significant accumulation of SOC. Carbon sequestration rates, with a change from CT to NT, can be expected to peak in 5 to 10 yr with SOC reaching a new equilibrium in 15 to 20 yr. Following initiation of an enhancement in rotation complexity, SOC may reach a new equilibrium in approximately 40 to 60 yr. Carbon sequestration rates, estimated for a number of individual crops and crop rotations in this study, can be used in spatial modeling analyses to more accurately predict regional, national, and global C sequestration potentials. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP West, TO (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Post, Wilfred/B-8959-2012; West, Tristram/C-5699-2013 OI West, Tristram/0000-0001-7859-0125 NR 116 TC 915 Z9 1002 U1 65 U2 513 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD NOV-DEC PY 2002 VL 66 IS 6 BP 1930 EP 1946 PG 17 WC Soil Science SC Agriculture GA 712JK UT WOS:000184794400025 ER PT J AU Lin, RP Dennis, BR Hurford, GJ Smith, DM Zehnder, A Harvey, PR Curtis, DW Pankow, D Turin, P Bester, M Csillaghy, A Lewis, M Madden, N Van Beek, HF Appleby, M Raudorf, T McTiernan, J Ramaty, R Schmahl, E Schwartz, R Krucker, S Abiad, R Quinn, T Berg, P Hashii, M Sterling, R Jackson, R Pratt, R Campbell, RD Malone, D Landis, D Barrington-Leigh, CP Slassi-Sennou, S Cork, C Clark, D Amato, D Orwig, L Boyle, R Banks, IS Shirey, K Tolbert, AK Zarro, D Snow, F Thomsen, K Henneck, R Mchedlishvili, A Ming, P Fivian, M Jordan, J Wanner, R Crubb, J Preble, J Matranga, M Benz, A Hudson, H Canfield, RC Holman, GD Crannell, C Kosugi, T Emslie, AG Vilmer, N Brown, JC Johns-Krull, C Aschwanden, M Metcalf, T Conway, A AF Lin, RP Dennis, BR Hurford, GJ Smith, DM Zehnder, A Harvey, PR Curtis, DW Pankow, D Turin, P Bester, M Csillaghy, A Lewis, M Madden, N Van Beek, HF Appleby, M Raudorf, T McTiernan, J Ramaty, R Schmahl, E Schwartz, R Krucker, S Abiad, R Quinn, T Berg, P Hashii, M Sterling, R Jackson, R Pratt, R Campbell, RD Malone, D Landis, D Barrington-Leigh, CP Slassi-Sennou, S Cork, C Clark, D Amato, D Orwig, L Boyle, R Banks, IS Shirey, K Tolbert, AK Zarro, D Snow, F Thomsen, K Henneck, R Mchedlishvili, A Ming, P Fivian, M Jordan, J Wanner, R Crubb, J Preble, J Matranga, M Benz, A Hudson, H Canfield, RC Holman, GD Crannell, C Kosugi, T Emslie, AG Vilmer, N Brown, JC Johns-Krull, C Aschwanden, M Metcalf, T Conway, A TI The Reuven Ramaty high-energy solar spectroscopic imager (RHESSI) SO SOLAR PHYSICS LA English DT Article ID WIND SPACECRAFT; ABUNDANCES; PARTICLES; PLASMA; FLARES AB RHESSI is the sixth in the NASA line of Small Explorer (SMEX) missions and the first managed in the Principal Investigator mode, where the PI is responsible for all aspects of the mission except the launch vehicle. RHESSI is designed to investigate particle acceleration and energy release in solar flares, through imaging and spectroscopy of hard X-ray/gamma-ray continua emitted by energetic electrons, and of gamma-ray lines produced by energetic ions. The single instrument consists of an imager, made up of nine bi-grid rotating modulation collimators (RMCs), in front of a spectrometer with nine cryogenically-cooled germanium detectors (GeDs), one behind each RMC. It provides the first high-resolution hard X-ray imaging spectroscopy, the first high-resolution gamma-ray line spectroscopy, and the first imaging above 100 keV including the first imaging of gamma-ray lines. The spatial resolution is as fine as similar to 2.3 are see with a full-Sun (greater than or similar to1degrees) field of view, and the spectral resolution is similar to 1 - 10 keV FWHM over the energy range from soft X-rays (3 keV) to gamma-rays (17 MeV). An automated shutter system allows a wide dynamic range (> 10(7)) of flare intensities to be handled without instrument saturation. Data for every photon is stored in a solid-state memory and telemetered to the ground, thus allowing for versatile data analysis keyed to specific science objectives. The spin-stabilized (similar to 15 rpm) spacecraft is Sun-pointing to within similar to 0.2degrees and operates autonomously. RHESSI was launched on 5 February 2002, into a nearly circular, 38degrees inclination, 600-km altitude orbit and began observations a week later. The mission is operated from Berkeley using a dedicated 11-m antenna for telemetry reception and command uplinks. All data and analysis software are made freely and immediately available to the scientific community. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. HF van Beek Onsultancy, NL-3971 LB Driebergen, Netherlands. Tecomet, Woburn, MA 01801 USA. Ortec, Oak Ridge, TN 37831 USA. Univ Appl Sci, CH-5210 Windisch, Switzerland. Spectrum Astro, Gilbert, AZ 85233 USA. SpaceWorks Inc, Carefree, AZ 85377 USA. Charles Stark Draper Lab Inc, Cambridge, MA 02139 USA. Univ Maryland, College Pk, MD 20742 USA. Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Swiss Fed Inst Technol, CH-8092 Zurich, Switzerland. Montana State Univ, Bozeman, MT 59717 USA. ISAS, Sagamihara, Kanagawa, Japan. Univ Alabama, Huntsville, AL 35899 USA. Observ Paris, Meudon, France. Univ Glasgow, Glasgow G12 8QW, Lanark, Scotland. Rice Univ, Houston, TX 77005 USA. Lockheed Martin, Palo Alto, CA 94304 USA. Open Univ, Milton Keynes MK7 6AA, Bucks, England. L3 Commun, New York, NY 10016 USA. RP Lin, RP (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Holman, Gordon/C-9548-2012; Dennis, Brian/C-9511-2012; OI Barrington-Leigh, Christopher/0000-0002-3929-5390 NR 16 TC 999 Z9 1010 U1 2 U2 24 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2002 VL 210 IS 1-2 BP 3 EP 32 DI 10.1023/A:1022428818870 PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 644YE UT WOS:000180948200001 ER PT J AU Smith, DM Lin, RP Turin, P Curtis, DW Primbsch, JH Campbell, RD Abiad, R Schroeder, P Cork, CP Hull, EL Landis, DA Madden, NW Malone, D Pehl, RH Raudorf, T Sangsingkeow, P Boyle, R Banks, IS Shirey, K Schwartz, R AF Smith, DM Lin, RP Turin, P Curtis, DW Primbsch, JH Campbell, RD Abiad, R Schroeder, P Cork, CP Hull, EL Landis, DA Madden, NW Malone, D Pehl, RH Raudorf, T Sangsingkeow, P Boyle, R Banks, IS Shirey, K Schwartz, R TI The RHESSI spectrometer SO SOLAR PHYSICS LA English DT Article ID DETECTORS; SPECTRA AB RHESSI observes solar photons over three orders of magnitude in energy (3 keV to 17 MeV) with a single instrument: a set of nine cryogenically cooled coaxial germanium detectors. With their extremely high energy resolution, RHESSI can resolve the line shape of every known solar gamma-ray line except the neutron capture line at 2.223 MeV. High resolution also allows clean separation of thermal and non-thermal hard X-rays and the accurate measurement of even extremely steep power-law spectra. Detector segmentation, fast signal processing, and two sets of movable attenuators allow RHESSI to make high-quality spectra and images of flares across seven orders of magnitude in intensity. Here we describe the configuration and operation of the RHESSI spectrometer, show early results on in-flight performance, and discuss the principles of spectroscopic data analysis used by the RHESSI software. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. ORTEC, Oak Ridge, TN USA. NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD USA. RP Smith, DM (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NR 14 TC 263 Z9 267 U1 1 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2002 VL 210 IS 1-2 BP 33 EP 60 DI 10.1023/A:1022400716414 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 644YE UT WOS:000180948200002 ER PT J AU Chevrel, SD Pinet, PC Daydou, Y Feldman, WC AF Chevrel, SD Pinet, PC Daydou, Y Feldman, WC TI Integration and comparison of Clementine and Lunar Prospector data: Global scale multielement analysis (Fe, Ti, and Th) of the lunar surface SO SOLAR SYSTEM RESEARCH LA English DT Article ID POLE AITKEN-BASIN; THORIUM ABUNDANCES; GAMMA-RAY; MOON; MANTLE; IRON; VOLCANISM; NEUTRONS; IMAGES AB In this paper, we present (1) a statistical analysis, based on a systematic clustering method, of a dataset integrating the global abundance maps of the three elements iron, titanium, and thorium derived from Clementine and Lunar Prospector and (2) a comparison of iron abundances between Clementine and Lunar Prospector. Homogeneous geologic units are compositionally characterized and spatially defined in relation to the major rock types sampled on the Moon. With the lowest abundances of Fe, Ti, and Th found on the Moon, the lunar highland terrains are quite homogeneous with two major large feldspathic units, one being slightly more mafic than the other. Two distinct regions with unique compositions are unambiguously identified: the Procellarum KREEP Terrane (PKT) and the South Pole-Aitken (SPA). The PKT, which includes an the units with Th abundances higher than 3-5 ppm, (KREEP-rich materials), is delimited by an almost continuous ringlike unit. In particulars it includes the western nearside maria, except for Mare Humorum. With concentrations in Fe, Ti, and Th enhanced relative to the surrounding highlands, the South Pole-Aitken basin floor represents a large mafic anomaly on the far side, suggesting wide deposits of lower crust and possible mantle materials. However, due to indirect residual latitude effects in the CSR (Clementine spectral reflectance) measurements, iron abundances might have been overestimated in SPA, thus implying that crustal materials. rather than mantle materials, might represent the dominant contributor to the mafic component exposed on the basin floor. C1 Observ Midi Pyrenees, UMR5562, GRGS, F-31400 Toulouse, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chevrel, SD (reprint author), Observ Midi Pyrenees, UMR5562, GRGS, F-31400 Toulouse, France. NR 40 TC 2 Z9 2 U1 1 U2 2 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD NOV-DEC PY 2002 VL 36 IS 6 BP 458 EP 465 DI 10.1023/A:1022196818051 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 630JX UT WOS:000180104700002 ER PT J AU Tang, Y Liu, Y Sampathkumaran, U Hu, MZ Wang, R De Guire, MR AF Tang, Y Liu, Y Sampathkumaran, U Hu, MZ Wang, R De Guire, MR TI Particle growth and particle-surface interactions during low-temperature deposition of ceramic thin films SO SOLID STATE IONICS LA English DT Article DE thin films : deposition methods; thin films : growth, structure, and epitaxy; thin films : dielectric; thin films : optical properties; thermodynamics : nucleation ID SELF-ASSEMBLED MONOLAYERS; ATOMIC-FORCE MICROSCOPY; AQUEOUS-SOLUTIONS; OXIDE; TIO2; MECHANISM; ZIRCONIA AB The forces between substrates and ceramic particles in aqueous solution were measured using an atomic force microscope (AFM). The dependence of the measured forces on the pH and ionic strength of the solution are presented. The trends are consistent with expectations based on the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The kinetics of the nucleation and growth of tin oxide particles in aqueous solutions of tin(IV) chloride and hydrochloric acid were studied using dynamic laser scattering. The rate of formation of particles as a function of solution temperature, concentration, and pH agrees with thermodynamic calculations and with previous observations. Antimony-doped tin oxide films on SAM-coated glass have been found to be several orders of magnitude more conductive than identical coatings on bare glass. Apatite thin films have been deposited from simulated body fluid (SBF) on titanium metal. The porous topography of the metal, produced by prior etching in hydrochloric acid, was preserved in the deposited apatite films. The adhesion of these films to the substrate appears to have been greatly increased by the etching step, compared to films deposited on unetched titanium. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Case Western Reserve Univ, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Case Western Reserve Univ, Sch Dent, Dept Restorat Dent, Cleveland, OH 44106 USA. RP Case Western Reserve Univ, Dept Mat Sci & Engn, 10900 Euclid Ave, Cleveland, OH 44106 USA. EM usampathkumaran@optinetries.com; mrd2@po.cwru.edu OI Hu, Michael/0000-0001-8461-9684 NR 20 TC 21 Z9 22 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 EI 1872-7689 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV PY 2002 VL 151 IS 1-4 BP 69 EP 78 AR PII S0167-2738(02)00584-2 DI 10.1016/S0167-2738(02)00584-2 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 623AT UT WOS:000179681400011 ER PT J AU Suzuki, T Kosacki, I Anderson, HU AF Suzuki, T Kosacki, I Anderson, HU TI Microstructure-electrical conductivity relationships in nanocrystalline ceria thin films SO SOLID STATE IONICS LA English DT Article DE ceria; nanocrystals; thin films; nonstoichiometry; impedance spectroscopy; electrical conductivity; defect model ID GD-DOPED CERIA; TRANSPORT-PROPERTIES; IONIC-CONDUCTIVITY; ZIRCONIA; DEFECT; OXIDE AB A study of nanocrystalline oxide thin film processing and influence of microstructure on the electrical properties of nanocrystalline Gd3+-doped CeO2 thin films was reported. Nanocrystalline films on sapphire substrate were prepared using a polymeric precursor spin coating technique. The grain size of these films depends upon the annealing temperatures and the dopant content, where higher content of dopant realized smaller grain size. The electrical conductivity of nanocrystalline Gd3+- doped CeO2 thin films was studied as a function of temperature and oxygen activity, and correlated with the grain size. The results show that the electronic conductivity of CeO2 increases, whereas the ionic conductivity increases in doped samples as the grain size decreases. From these results, the enthalpy of oxygen vacancy formation was determined as a function of grain size. For CeO2 sample, an enhancement of electronic conductivity was observed with decreasing grain size below 100 rim. In the case of Gd3+-doped CeO2, the electrical conductivity results show that an increase of the ionic conductivity was observed as the grain size decreased, which is related to a decrease in the activation energy for the ion mobility. (C) 2002 Elsevier Science B.V All rights reserved. C1 Univ Missouri, Elect Mat Appl Res Ctr, Rolla, MO 65401 USA. RP Oak Ridge Natl Lab, Stuct Ceram Grp, Div Met & Ceram, POB 2008,Rm 259,Bldg 4515,MS 6068, Oak Ridge, TN 37831 USA. EM kosackiip@ornl.gov NR 19 TC 188 Z9 192 U1 7 U2 54 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 EI 1872-7689 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV PY 2002 VL 151 IS 1-4 BP 111 EP 121 AR PII S0167-2738(02)00589-1 DI 10.1016/S0167-2738(02)00589-1 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 623AT UT WOS:000179681400016 ER PT J AU Pechersky, MJ AF Pechersky, M. J. TI Determination of Residual Stresses by Thermal Relaxation and Speckle Correlation Interferometry SO STRAIN LA English DT Article DE residual stress; electronic speckle pattern interferometry; laser heating; thermal stress relief AB A new technique for the measurement of residual stresses is presented. The technique is based on strain measurements following thermal stress relaxation. The heat input is supplied by a low power infrared laser and the strain is measured with speckle pattern correlation interferometry. This paper presents a comprehensive overview of the technique and an example of how it has been applied in a practical situation. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Pechersky, MJ (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. FU United States Department of Energy [DE-AC09-963R18500] FX This work was sponsored by the United States Department of Energy, Contract Number DE-AC09-963R18500. NR 22 TC 7 Z9 7 U1 0 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0039-2103 J9 STRAIN JI Strain PD NOV PY 2002 VL 38 IS 4 BP 141 EP 149 DI 10.1111/j.1475-1305.2002.00030.x PG 9 WC Materials Science, Characterization & Testing SC Materials Science GA V22DW UT WOS:000208256900003 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Thanos, P Logan, J Gatley, SJ Gifford, A Ding, YS Wong, C Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Thanos, P Logan, J Gatley, SJ Gifford, A Ding, YS Wong, C Pappas, N TI Brain DA D2 receptors predict reinforcing effects of stimulants in humans: Replication study SO SYNAPSE LA English DT Article DE raclopride; addiction; vulnerability; PET; methylphenidate; reinforcement; striatum ID DOPAMINE TRANSPORTERS; C-11 RACLOPRIDE; BINDING; METABOLISM; COCAINE; METHYLPHENIDATE; AVAILABILITY; ASSOCIATION; ALCOHOLISM; RESPONSES AB We had shown that striatal DA D2 receptors levels predicted the reinforcing responses to the psychostimulant drug methylphenidate in nondrug-abusing subjects. Here, we assessed the replicability of this finding. We measured D2 receptors with PET and [C-11]raclopride (twice to determine stability) in seven nondrug-abusing subjects to assess if they predicted the self-reports of "drug-liking" to intravenous methylphenidate (0.5 mg/kg). DA D2 measures were significantly correlated with "drug-liking" in both evaluations (r = 0.82 and r = 0.78); subjects with the lowest levels reported the higher ratings of "drug-liking" and vice versa. These results replicate our previous findings and provide further evidence that striatal DA D2 receptors modulate reinforcing responses to stimulants in humans and may underlie predisposition for drug self-administration. (C) 2002 Wiley-Liss, Inc. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Volkow, ND (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. OI Logan, Jean/0000-0002-6993-9994 FU NIDCR NIH HHS [DE-AC02-798CH10886] NR 22 TC 140 Z9 141 U1 7 U2 11 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-4476 J9 SYNAPSE JI Synapse PD NOV PY 2002 VL 46 IS 2 BP 79 EP 82 DI 10.1002/syn.10137 PG 4 WC Neurosciences SC Neurosciences & Neurology GA 600WA UT WOS:000178413700005 PM 12211085 ER PT J AU Marcinow, Z Sygula, A Rabideau, PW AF Marcinow, Z Sygula, A Rabideau, PW TI Improved synthesis of benz[a]acephenanthrene SO SYNLETT LA English DT Article DE Wittig reaction; photocyclization; benz[a]acephenantrene AB A convenient, three-step synthesis of benz[a]acephenanthrene (6) from commercially available materials is described. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Marcinow, Z (reprint author), Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. EM Rabideau@iastate.edu NR 8 TC 1 Z9 1 U1 0 U2 0 PU GEORG THIEME VERLAG KG PI STUTTGART PA RUDIGERSTR 14, D-70469 STUTTGART, GERMANY SN 0936-5214 J9 SYNLETT JI Synlett PD NOV PY 2002 IS 11 BP 1839 EP 1840 PG 2 WC Chemistry, Organic SC Chemistry GA 612VV UT WOS:000179096900018 ER PT J AU Degasperis, A Holm, DD Hone, ANW AF Degasperis, A Holm, DD Hone, ANW TI A new integrable equation with peakon solutions SO THEORETICAL AND MATHEMATICAL PHYSICS LA English DT Article; Proceedings Paper CT 15th International Conference on Nonlinear Evolution Equations and Dynamical Systems CY JUL 23-31, 2001 CL CAMBRIDGE, ENGLAND SP Isaac Newton Inst Math Sci DE peakons; reciprocal transformations; weak solutions ID PARTIAL-DIFFERENTIAL EQUATIONS; CAMASSA-HOLM EQUATION; SOLITONS AB We consider a new partial differential equation recently obtained by Degasperis and Procesi using the method of asymptotic integrability; this equation has a form similar to the Camassa-Holm shallow water wave equation. We prove the exact integrability of the new equation by constructing its Lax pair and explain its relation to a negative flow in the Kaup-Kupershmidt hierarchy via a reciprocal transformation. The infinite sequence of conserved quantities is derived together with a proposed bi-Hamiltonian structure, The equation admits exact solutions as a superposition of multipeakons, and we describe the integrable finite-dimensional peakon dynamics and compare it with the analogous results for Camassa-Holm peakons. C1 Univ Roma La Sapienza, Dipartimento Fis, Sez Roma, Ist Nazl Fis Nucl, Rome, Italy. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Kent, Inst Math & Stat, Canterbury, Kent, England. RP Degasperis, A (reprint author), Univ Roma La Sapienza, Dipartimento Fis, Sez Roma, Ist Nazl Fis Nucl, Rome, Italy. RI Hone, Andrew/K-2989-2012; OI Hone, Andrew/0000-0001-9780-7369; Holm, Darryl D/0000-0001-6362-9912 NR 21 TC 274 Z9 281 U1 1 U2 13 PU CONSULTANTS BUREAU PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0040-5779 J9 THEOR MATH PHYS+ JI Theor. Math. Phys. PD NOV PY 2002 VL 133 IS 2 BP 1463 EP 1474 DI 10.1023/A:1021186408422 PG 12 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 629QY UT WOS:000180061400004 ER PT J AU Visser, R Dauble, DD Geist, DR AF Visser, R Dauble, DD Geist, DR TI Use of aerial photography to monitor fall chinook salmon spawning in the Columbia River SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article AB This paper compares two methods of enumerating the redds of chinook salmon Oncorhynchus tshawytscha and their application to the monitoring of spawning activity. In 1994 and 1995, aerial photographs of fall chinook salmon spawning areas in the Hanford Reach of the Columbia River were digitized and mapped by means of geographical information systems techniques as part of annual population assessments. The numbers of redds visible in these photographs were compared with the counts obtained from visual surveys made from fixed-wing aircraft. The proportions of the total redds in each of five general survey areas were similar for the two enumeration techniques. However, the total number of redds based on aerial photographs was 2.2 times as high as that observed visually in 1994 and 3.0 times as high in 1995. The divergence in redd counts was most evident near the time of peak spawning activity, when the number of redds in individual spawning clusters exceeded 500. Aerial photography thus improved our ability to determine the number of visible salmon redds and to quantify habitat use. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Washington Dept Fish & Wildlife, Grandview, WA 98930 USA. RP Dauble, DD (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 12 TC 6 Z9 6 U1 0 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD NOV PY 2002 VL 131 IS 6 BP 1173 EP 1179 DI 10.1577/1548-8659(2002)131<1173:UOAPTM>2.0.CO;2 PG 7 WC Fisheries SC Fisheries GA 643VE UT WOS:000180881100015 ER PT J AU Yang, W Sokhansanj, S Siebenmorgen, TJ Howard, L AF Yang, W Sokhansanj, S Siebenmorgen, TJ Howard, L TI Development of a method for determining moisture diffusivity of alfalfa grind under surface condensation SO TRANSACTIONS OF THE ASAE LA English DT Article DE moisture diffusivity; surface condensation; alfalfa processing; thin-layer drying or rewetting; parameter estimation ID MICROWAVE AB A method, referred to as the "ring stack" method, based on one-dimensional diffusion in a semi-infinite cylinder has been developed to measure the moisture diffusivity of a powder material like ground alfalfa when exposed to steam. This method and the diffusion model associated with it have been evaluated using regression statistics. Through the lack-of-fit test, it was found statistically (a = 0.05) that the diffusion model associated with the "ring stack" method represented very well the experimental data on ground alfalfa under steam condensation. Moisture diffusivity of ground alfalfa measured by the "ring stack" method was 5.90 X 10(-8) 4.72 X 10(-9) m(2)/s, which compared favorably with published data. C1 Univ Arkansas, Dept Food Sci, Fayetteville, AR 72704 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Yang, W (reprint author), Univ Arkansas, Dept Food Sci, 2650 N Young Ave, Fayetteville, AR 72704 USA. NR 20 TC 1 Z9 1 U1 1 U2 1 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 USA SN 0001-2351 J9 T ASAE JI Trans. ASAE PD NOV-DEC PY 2002 VL 45 IS 6 BP 1919 EP 1924 PG 6 WC Agricultural Engineering SC Agriculture GA 648AE UT WOS:000181125600022 ER PT J AU Sun, Y Petersen, JN Buscheck, TA Nitao, JJ AF Sun, Y Petersen, JN Buscheck, TA Nitao, JJ TI Analytical solutions for reactive transport of multiple volatile contaminants in the vadose zone SO TRANSPORT IN POROUS MEDIA LA English DT Article DE analytical solution; vadose zone; multi-species transport; VOC; first-order reaction ID SUBSURFACE TRANSPORT; ORGANIC-COMPOUNDS; POROUS-MEDIA; MODEL; BIODEGRADATION; SORPTION; DECAY; GROUNDWATER; KINETICS; IMPACT AB Groundwater contamination usually originates from surface contamination. Contaminants then move downward through the vadose zone and finally reach the groundwater table. To date, however, analytical solutions of multi-species reactive transport are limited to transport only in the saturated zone. The motivation of this work is to utilize analytical solutions, which were previously derived for single-phase transport, to describe the reactive transport of multiple volatile contaminants in the unsaturated zone. A mathematical model is derived for describing transport with phase partitioning of sequentially reactive species in the vadose zone with constant flow velocity. Linear reaction kinetics and linear equilibrium partitioning between vapor, liquid, and solid phases are assumed in this model. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Washington State Univ, WSU NSF IGERT Ctr Multiphase Environm Res, Pullman, WA 99164 USA. RP Sun, Y (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Petersen, James/B-8924-2008; Sun, Yunwei/C-9751-2010 NR 30 TC 3 Z9 3 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD NOV PY 2002 VL 49 IS 2 BP 175 EP 190 DI 10.1023/A:1016023526537 PG 16 WC Engineering, Chemical SC Engineering GA 567VY UT WOS:000176507400003 ER PT J AU Wu, YS AF Wu, YS TI Numerical simulation of single-phase and multiphase non-darcy flow in porous and fractured reservoirs SO TRANSPORT IN POROUS MEDIA LA English DT Article DE non-Darcy flow; numerical reservoir simulation; well tests; multiphase flow; porous and fractured reservoirs ID MEDIA AB A numerical method as well as a theoretical study of non-Darcy fluid flow through porous and fractured reservoirs is described. The non-Darcy behavior is handled in a three-dimensional, multiphase flow reservoir simulator, while the model formulation incorporates the Forchheimer equation for describing single-phase or multiphase non-Darcy flow and displacement. The non-Darcy flow through a fractured reservoir is handled using a general dual-continuum approach. The numerical scheme has been verified by comparing its results against those of analytical methods. Numerical solutions are used to obtain some insight into the physics of non-Darcy flow and displacement in reservoirs. In addition, several type curves are provided for well-test analyses of non-Darcy flow to demonstrate a methodology for modeling this type of flow in porous and fractured rocks, including flow in petroleum and geothermal reservoirs. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Wu, YS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Wu, Yu-Shu/A-5800-2011 NR 30 TC 49 Z9 56 U1 5 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD NOV PY 2002 VL 49 IS 2 BP 209 EP 240 DI 10.1023/A:1016018020180 PG 32 WC Engineering, Chemical SC Engineering GA 567VY UT WOS:000176507400005 ER PT J AU Tissue, DT Lewis, JD Wullschleger, SD Amthor, JS Griffin, KL Anderson, R AF Tissue, DT Lewis, JD Wullschleger, SD Amthor, JS Griffin, KL Anderson, R TI Leaf respiration at different canopy positions in sweetgum (Liquidambar styraciflua) grown in ambient and elevated concentrations of carbon dioxide in the field SO TREE PHYSIOLOGY LA English DT Article; Proceedings Paper CT Workshop on Linking the Complexity of Forest Canopies to Ecosystem and Landscape Function CY JUL 11-19, 2001 CL OREGON STATE UNIV, CORVALLIS, OREGON SP Int Union Forest Res Org, Canopy Processes Working Grp, USDA Forest Serv, Rocky Mt Res Stn, NASA HO OREGON STATE UNIV DE carbohydrates; cytochrome c oxidase; daytime respiration; forest trees; Free-Air CO2 Enrichment (FACE); nighttime respiration; number of mitochondria ID ATMOSPHERIC CO2 CONCENTRATION; DARK RESPIRATION; DIRECT INHIBITION; MITOCHONDRIAL RESPIRATION; NITROGEN ALLOCATION; PARTIAL-PRESSURE; GAS-EXCHANGE; O-2 UPTAKE; PLANT; TREE AB Trees exposed to elevated CO2 partial pressure ([CO2]) generally show increased rates of photosynthesis and growth, but effects on leaf respiration are more variable. The causes of this variable response are unresolved. We grew 12-year-old sweetgum trees (Liquidambar styraciflua L.) in a Free-Air CO2 Enrichment (FACE) facility in ambient [CO2] (37/44 Pa daytime/nighttime) and elevated [CO2] (57/65 Pa daytime/nighttime) in native soil at Oak Ridge National Environmental Research Park. Nighttime respiration (R-N) was measured on leaves in the upper and lower canopy in the second (1999) and third (2000) growing seasons of CO2 fumigation. Leaf respiration in the light (R-L) was estimated by the technique of Brooks and Farquhar (1985) in the upper canopy during the third growing season. There were no significant short-term effects of elevated [CO2] on R-N or long-term effects on R-N or R-L, when expressed on an area, mass or nitrogen (N) basis. Upper-canopy leaves had 54% higher R-N (area basis) than lower-canopy leaves, but this relationship was unaffected by CO2 growth treatment. In August 2000, R-L was about 40% of R-N in the upper canopy. Elevated [CO2] significantly increased the number of leaf mitochondria (62%), leaf mass per unit area (LMA; 9%), and leaf starch (31%) compared with leaves in ambient [CO2]. Upper-canopy leaves had a significantly higher number of mitochondria (73%), N (53%), LMA (38%), sugar (117%) and starch (23%) than lower-canopy leaves. Growth in elevated [CO2] did not affect the relationships (i.e., intercept and slope) between R-N and the measured leaf characteristics. Although no factor explained more than 45% of the variation in R-N, leaf N and LMA were the best predictors for R-N. Therefore, the response of R-N to CO2 treatment and canopy position was largely dependent on the magnitude of the effect of elevated [CO2] or canopy position on these characteristics. Because elevated [CO2] had little or no effect on N or LMA, there was no effect on R-N. Canopy position had large effects on these leaf characteristics, however, such that upper-canopy leaves exhibited higher RN than lower-canopy leaves. We conclude that elevated [CO2] does not directly impact leaf respiration in sweetgum and that barring changes in leaf nitrogen or leaf chemical composition, long-term effects of elevated [CO2] on respiration in this species will be minimal. C1 Texas Tech Univ, Dept Biol, Lubbock, TX 79409 USA. Fordham Univ, Louis Calder Ctr, Biol Stn, Armonk, NY 10504 USA. Fordham Univ, Dept Biol Sci, Armonk, NY 10504 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Tissue, DT (reprint author), Texas Tech Univ, Dept Biol, Lubbock, TX 79409 USA. RI Wullschleger, Stan/B-8297-2012; Griffin, Kevin/B-2629-2013; Tissue, David/H-6596-2015 OI Wullschleger, Stan/0000-0002-9869-0446; Griffin, Kevin/0000-0003-4124-3757; Tissue, David/0000-0002-8497-2047 NR 50 TC 48 Z9 50 U1 2 U2 17 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 NOV PY 2002 VL 22 IS 15-16 BP 1157 EP 1166 PG 10 WC Forestry SC Forestry GA 615HE UT WOS:000179239100012 PM 12414375 ER PT J AU Bair, S McCabe, C Cummings, PT AF Bair, S McCabe, C Cummings, PT TI Calculation of viscous EHL traction for squalane using molecular simulation and rheometry SO TRIBOLOGY LETTERS LA English DT Article DE EHL traction; high-pressure rheology; shear-thinning; nonequilibrium molecular dynamics simulation; elastohydrodynamics ID SHEAR; TEMPERATURE; VISCOSITY; PRESSURE; FLOW AB Recently, remarkable agreement was reported between nonequilibrium molecular dynamics simulation and high-pressure Couette rheometry on squalane. We have utilized the viscosity-strain rate relationship obtained from this unique combination of experimental and simulation data along with high-pressure viscometer measurements to calculate the viscous traction curve in the elastohydrodynamic lubrication (EHL) regime. A comparison with measured traction at 0.57 and 1.29 GPa shows excellent agreement, confirming the validity of the measurements and simulations. Thus, we present for the first time, a successful calculation of EHL traction from the liquid shear response obtained from both molecular dynamics and rheometry. C1 Georgia Inst Technol, George W Woodruff Sch Mech Engn, Ctr High Pressure Rheol, Atlanta, GA 30332 USA. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Univ Tennessee, Dept Chem Engn Chem & Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Bair, S (reprint author), Georgia Inst Technol, George W Woodruff Sch Mech Engn, Ctr High Pressure Rheol, Atlanta, GA 30332 USA. RI McCabe, Clare/I-8017-2012; Cummings, Peter/B-8762-2013 OI McCabe, Clare/0000-0002-8552-9135; Cummings, Peter/0000-0002-9766-2216 NR 21 TC 31 Z9 36 U1 2 U2 15 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD NOV PY 2002 VL 13 IS 4 BP 251 EP 254 DI 10.1023/A:1021011225316 PG 4 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 614HU UT WOS:000179183000004 ER PT J AU Hunt, AG Gee, GW AF Hunt, Allen G. Gee, Glendon W. TI Water-Retention of Fractal Soil Models Using Continuum Percolation Theory: Tests of Hanford Site Soils SO VADOSE ZONE JOURNAL LA English DT Article AB For 43 Hanford site soils, we use fractal analysis and assume proportionality of pore radii to particle radii to generate water-retention curves, h(theta), from particle-size distributions. The air-entry head is used as an adjustable parameter to optimize the fit to experimental data for h(theta). At a low moisture content, theta(d), the predicted and observed water-retention curves deviate. It is shown here that the moisture content at which this deviation occurs is in most cases probably the same value, at which previous experiments found a vanishing of solute diffusion. Where this correlation is indicated, we interpret theta(d) as a critical moisture content for percolation of capillary flow paths, and the relevance of other mechanisms of water transport, such as film flow, to equilibration at lower moisture contents. In other individual cases, however, the deviation is correlated with very low values of the hydraulic conductivity associated with capillary flow. In either case, we infer that the deviation from fractal predictions is due to the lack of equilibration of the medium. Our work thus exploits theoretical and analytical gains from percolation theory and fractal analysis to define the equilibrium limits on water retention curves. C1 [Hunt, Allen G.] Univ Colorado, CIRES, Boulder, CO 80309 USA. [Gee, Glendon W.] Pacific NW Natl Lab, Hydrol Grp, Richland, WA 99352 USA. RP Hunt, AG (reprint author), Univ Colorado, CIRES, Box 216, Boulder, CO 80309 USA. EM ahunt@nsf.gov FU Department of Energy's Richland Operations Office [DE-AC06-76RL01830] FX The authors are grateful to Eugene Freeman for directing us to key Hanford soil data, including his Master's Thesis, and for helping us complete Table 1. This study was funded by the Vadose-Zone Transport Field Study, which is part of the Hanford Science and Technology Program of the Department of Energy's Richland Operations Office under Contract DE-AC06-76RL01830. NR 36 TC 47 Z9 47 U1 1 U2 10 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 1539-1663 J9 VADOSE ZONE J JI Vadose Zone J. PD NOV PY 2002 VL 1 IS 2 BP 252 EP 260 PG 9 WC Environmental Sciences; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA V11UX UT WOS:000207557600004 ER PT J AU Sisson, JB Gee, GW Hubbell, JM Bratton, WL Ritter, JC Ward, AL Caldwell, TG AF Sisson, J. B. Gee, G. W. Hubbell, J. M. Bratton, W. L. Ritter, J. C. Ward, A. L. Caldwell, T. G. TI ADVANCES IN TENSIOMETRY FOR LONG-TERM MONITORING OF SOIL WATER PRESSURES SO VADOSE ZONE JOURNAL LA English DT Article AB Soil water pressures, measured over space and time, are needed to predict the direction of water flow and chemical transport in the vadose zone. Advanced tensiometers (ATs), which utilize a waterfilled porous cup connected directly to a pressure transducer, can be installed at almost any location and depth using standard drilling techniques such as auger drilling, but these methods can significantly disturb the site. For sites where minimal disturbance is desired, alternate approaches for tensiometer placement have been sought. To test installation techniques and performance longevity, advanced tensiometers were placed into the ground at a test site near Richland, WA using two different installation methods, auger drilling and a drive-cone push technique. The tensiometers were subsequently monitored for nearly 2 yr without refilling or recalibration. The data indicated that tensiometers placed by the auger technique took several months to equilibrate, while the cone push units came to equilibrium within 24 h following their installation. Soil water pressures always remained above -90 cm pressure head (-90 mbar) at depths >90 cm. At the greatest depth (730 cm), positive then negative pressures were observed as the water table was lowered and the soil drained. The results suggest that for our test conditions (coarse sandy soil, no vegetation), soil water pressures stay well within the tensiometer range and unit gradient conditions persist, indicating a draining profile. Advanced tensiometers, placed either by auger or cone penetrometer, provide a robust and reliable method for long-term monitoring of soil water pressure profiles. C1 [Gee, G. W.; Ritter, J. C.; Ward, A. L.] Pacific NW Natl Lab, Environm Technol Div, Hydrol Grp, Richland, WA 99352 USA. [Sisson, J. B.; Hubbell, J. M.] Bechtel Idaho Inc, Idaho Natl Engn & Environm Lab, Geosci Res Dept, Idaho Falls, ID 83415 USA. [Bratton, W. L.] Appl Res Associates Inc, Richland, WA 99352 USA. [Caldwell, T. G.] Desert Res Inst, Reno, NV 89512 USA. RP Gee, GW (reprint author), Pacific NW Natl Lab, Environm Technol Div, Hydrol Grp, Richland, WA 99352 USA. EM glendon.gee@pnl.gov RI Caldwell, Todd/H-5129-2011 OI Caldwell, Todd/0000-0003-4068-0648 FU U.S. Department of Energy's Hanford Science and Technology [DE-AC06-76RL01830]; Ground Water/Vadose Zone Integration FX This work was conducted under the direction of the Pacific Northwest National Laboratory with funding from the U.S. Department of Energy's Hanford Science and Technology Initiative and the Ground Water/Vadose Zone Integration Project. Battelle under Contract DE-AC06-76RL01830 operates Pacific Northwest National Laboratory for the U.S. Department of Energy. NR 13 TC 13 Z9 14 U1 4 U2 9 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 1539-1663 J9 VADOSE ZONE J JI Vadose Zone J. PD NOV PY 2002 VL 1 IS 2 BP 310 EP 315 PG 6 WC Environmental Sciences; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA V11UX UT WOS:000207557600010 ER PT J AU Eliassi, M Glass, RJ AF Eliassi, M Glass, RJ TI On the porous-continuum modeling of gravity-driven fingers in unsaturated materials: Extension of standard theory with a hold-back-pile-up effect SO WATER RESOURCES RESEARCH LA English DT Article DE wetting front instability; gravity-driven fingers; nonmonotonicity; extended porous media theory; hypodiffusive and hyperbolic flux relations; dynamic capillary pressure ID WETTING FRONT INSTABILITY; STABILITY ANALYSIS; WATER-MOVEMENT; LAYERED SOILS; RICHARDS EQUATION; 2-PHASE FLOW; IMMISCIBLE DISPLACEMENT; HYDRAULIC CONDUCTIVITY; MACROSCOPIC EQUATIONS; PREFERENTIAL FLOW AB The traditional Richards equation (RE) in combination with standard monotonic properties (constitutive relations and hysteretic equations of state) has been shown to lack critical physics required to model gravity-driven fingering (GDF). We extend the RE with an experimentally observed hold-back-pile-up (HBPU) effect not captured in the standard porous-continuum RE formulation. We postulate the HBPU effect is tied to wetting front sharpness and can be mathematically formulated in a variety of ways to include hypodiffusive, hyperbolic, and mixed spatial-temporal forms involving respectively a Laplacian, a second-order derivative in time, and a Laplacian of a first-order derivative in time of the state variables. For each, we can infer an extended flux relation comprised of the Darcy-Buckingham flux plus an additional component due to the HBPU effect. Extended flux relations that are mathematically similar to each can be found in the single-phase and multiphase flow literature, however, all with very different underlying conceptualizations of the possible physics. C1 Sandia Natl Labs, Flow Visualizat & Proc Lab, Albuquerque, NM 87185 USA. RP Eliassi, M (reprint author), Sandia Natl Labs, Flow Visualizat & Proc Lab, POB 5800, Albuquerque, NM 87185 USA. NR 79 TC 36 Z9 36 U1 0 U2 3 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 NOV PY 2002 VL 38 IS 11 AR 1234 DI 10.1029/2001WR001131 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 637RX UT WOS:000180527800016 ER PT J AU Liu, HH Bodvarsson, GS Pan, L AF Liu, HH Bodvarsson, GS Pan, L TI Comment on "Determination of particle transfer in random walk particle methods for fractured porous media" by H.H. Liu et al. Reply SO WATER RESOURCES RESEARCH LA English DT Editorial Material DE particle tracking; solute transport; fractured porous media C1 Ernest Orlando Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Liu, HH (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Pan, Lehua/G-2439-2015 NR 3 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 2002 VL 38 IS 11 AR 1222 DI 10.1029/2002WR001568 PG 2 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 637RX UT WOS:000180527800004 ER PT J AU Tidwell, VC Wilson, JL AF Tidwell, VC Wilson, JL TI Visual attributes of a rock and their relationship to permeability: A comparison of digital image and minipermeameter data SO WATER RESOURCES RESEARCH LA English DT Article DE permeability; digital images; heterogeneity; minipermeameter; permeability surrogates; image analysis ID HYDRAULIC CONDUCTIVITY; HETEROGENEITY; SANDSTONE; SCALE; BLOCK; SEGMENTATION; GENERATION; TRANSPORT; DEPOSITS; MIXTURES AB [1] What is the relationship between the visual attributes of a rock sample and its permeability, and how might such information be used in aquifer/reservoir characterization? We investigated these questions by way of three meter-scale blocks of rock, two sandstones, and one volcanic tuff. Each rock exhibits visual and permeability patterns that differ in geometry, intensity, and scale. Using a gas minipermeameter, hundreds to thousands of permeability values were collected on grids at centimeter-scale resolution from each block face and compared to the digital visual image of the same face. We found no significant direct correlation between the permeability measurements and any objective textural measure drawn from the corresponding digital images, despite the obvious resemblance of the permeability maps and visual images. Hypothesizing that the human eye relies on spatial correlation to synthesize information, we calculated and compared semivariograms for both the maps and the images. Semivariogram shape, anisotropy ratio, and principal axes orientation were consistent for the maps and images of each rock but different between rocks. To explore this similarity further, we compared discrete features appearing in map/image pairs, using a difference of Gaussian edge filter to segment (i.e., delineate) the spatial features. The filter consistently colocated visually sharp features, such as sedimentological bounding surfaces, in both the map and the image. Additionally, cumulative distribution functions characterizing the size, shape, and orientation of the segmented features were statistically indistinguishable between a permeability map and its corresponding visual image but statistically different between rocks. These results suggest that it may not always be possible to use visual images (photographs or scans) of outcrops to directly map permeability, even with a training set of punctual permeability data. In particular, defining such relations may be difficult where the scales of analysis and/or intensity of heterogeneity are limited (e. g., within a given facies) as is the case here. Where direct mapping is not possible, these results suggest that visual images can still be used to delineate spatial permeability patterns, especially to locate boundaries where sharp permeability contrasts occur. Other surrogate measurements of permeability, in particular the various geophysical methods, may exhibit similar behavior. C1 Sandia Natl Labs, Geohydrol Dept, 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, Geohydrol Dept, Mail Stop 0735, Albuquerque, NM 87185 USA. NR 49 TC 8 Z9 8 U1 1 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 NOV PY 2002 VL 38 IS 11 AR 1261 DI 10.1029/2001WR000932 PG 13 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 637RX UT WOS:000180527800043 ER PT J AU Vasquez, DA Smith, DH Edwards, BF AF Vasquez, DA Smith, DH Edwards, BF TI Influence of terrain on scaling laws for river networks SO WATER RESOURCES RESEARCH LA English DT Article DE river networks; river basins; self-organization; power laws ID MASS AB [1] The upper Cheat River network departs from scaling laws describing a large number of river networks in North America. This departure is traced to its corrugated terrain. The more typical random terrain of the lower Cheat River network obeys the standard scaling laws. We modify the random network model of Scheidegger to include the effects of topography, reproducing the behavior observed in the Cheat River basin. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Vasquez, DA (reprint author), US DOE, Natl Energy Technol Lab, POB 880, Morgantown, WV 26507 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 2002 VL 38 IS 11 AR 1260 DI 10.1029/2000WR000152 PG 5 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 637RX UT WOS:000180527800042 ER PT J AU Wu, YS Zhang, W Pan, LH Hinds, J Bodvarsson, GS AF Wu, YS Zhang, W Pan, LH Hinds, J Bodvarsson, GS TI Modeling capillary barriers in unsaturated fractured rock SO WATER RESOURCES RESEARCH LA English DT Article DE capillary barriers; unsaturated zone; fractured porous media; Richards' equation; dual-continuum model ID DOWNWARD WATER-FLOW; SLOPING LAYERS; VADOSE ZONE; DRIVE AB [1] This work presents a series of numerical modeling studies that investigate the hydrogeologic conditions required to form capillary barriers and the effect that capillary barriers have on fluid flow and tracer transport processes in the unsaturated fractured rock of Yucca Mountain, Nevada, a potential site for storing high-level radioactive waste. The modeling approach is based on a dual-continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. The numerical modeling results showed that effective capillary barriers can develop where both matrix and fracture capillary gradients tend to move water upward. Under the current hydrogeologic conceptualization of Yucca Mountain, strong capillary barrier effects exist for diverting a significant amount of moisture flow through the relatively shallow Paintbrush nonwelded unit, with major faults observed at the site serving as major downward pathways for laterally diverted percolation fluxes. In addition, we used observed field liquid saturation and goechemical isotopic data to check model results and found consistent agreement. C1 Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Wu, YS (reprint author), Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Wu, Yu-Shu/A-5800-2011; Pan, Lehua/G-2439-2015 NR 30 TC 15 Z9 16 U1 2 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 NOV PY 2002 VL 38 IS 11 AR 1253 DI 10.1029/2001WR000852 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 637RX UT WOS:000180527800035 ER PT J AU Vianco, PT Hosking, FM Stephens, JJ Walker, CA Neilsen, MK Glass, SJ Monroe, SL AF Vianco, PT Hosking, FM Stephens, JJ Walker, CA Neilsen, MK Glass, SJ Monroe, SL TI Aging of braze joints: Interface reactions in base metal/filler metal couples, part II: High-temperature Au-Ni-Ti braze alloy SO WELDING JOURNAL LA English DT Article DE brazing; brazement; ceramic; Inconel (R); Thermo-Span (TM); aging; precipitation strengthening AB The effects of aging were examined in brazed joints made with 81Au-17.5Ni-1.5Ti filler metal and ThermoSpan(TM) or AISI Type 347 stainless steel base metals. Excellent wetting and spreading were observed with both base metals. The Thermo-Span/Au-Ni-Ti and AISI Type 347 stainless steel/Au-Ni-Ti joints exhibited an interdiffusion zone at the base metal/filler metal interfaces. Aging caused the interfacial diffusion zone to grow. Four-point bend strength tests and microstructural analysis identified a phase precipitation mechanism that maximized the joint strength when aged at 460degreesC. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Vianco, PT (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD NOV PY 2002 VL 81 IS 11 BP 256S EP 264S PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 746VC UT WOS:000186767500015 ER PT J AU Henning, RW Corbett, JD AF Henning, RW Corbett, JD TI Na30.5AgxGa60-x: A three-dimensional network composed of Ga-3, Ga-12, and Ga-18 clusters SO ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE LA English DT Article DE cluster compounds; electron-deficient bonding; gallides; solid state chemistry; Zintl anions ID INTERMETALLIC PHASE; CRYSTAL-STRUCTURE; GALLIUM; SODIUM; METALS AB Single crystal X-ray structural determinations for Na30.5Ag2.6(2)Ga57.4(2) and Na30.5Ag6.4(2)Ga53.6(2) (P6lmmin, Z = 1) reveal Ga-3 triangles, Ga-12 icosahedra, and Ga-18 hexacapped hexagonal prisms that are interconnected into a three-dimensional network. Silver substitutes on the outer gallium sites of the Gals unit and presumably stabilizes the structure by reduction of the overall electron count. The two compositions are close to the limits of a nonstoichiometry region in Ga-Ag content, whereas the sodium content does not vary significantly. Stacking of the (Ga,Ag)(18) "drums" along creates a channel in which some typically less well localized sodium atoms reside; other sodium cations lie between the clusters and bond to gallium atoms in typical roles. Apparently isotypic analogues of this structure that are more or less well ordered are also known for other combinations of elements. Extended Huckel MO and band calculations were performed in order to gain a better understanding of the silver compound. The variable electron count observed falls in a region of relatively nonbonding states with only a small dependence on energy. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 26 TC 3 Z9 3 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0044-2313 J9 Z ANORG ALLG CHEM JI Z. Anorg. Allg. Chem. PD NOV PY 2002 VL 628 IS 12 BP 2715 EP 2723 DI 10.1002/1521-3749(200212)628:12<2715::AID-ZAAC2715>3.0.CO;2-A PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 615MQ UT WOS:000179250200025 ER PT J AU Mundy, CJ Colvin, ME Quong, AA AF Mundy, CJ Colvin, ME Quong, AA TI Irradiated guanine: A Car-Parrinello molecular dynamics study of dehydrogenation in the presence of an OH radical SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; CRYSTALLINE CYTOSINE MONOHYDRATE; LOCALIZED WANNIER FUNCTIONS; COUPLED ELECTRON-TRANSFER; DNA-BASE PAIRS; IONIZING-RADIATION; PARAMAGNETIC-RESONANCE; AQUEOUS-SOLUTION; AB-INITIO; 10 K AB Understanding the basic chemistry of the interaction of radicals with DNA bases is imperative when trying to elucidate the potential effects of radiation on DNA. Experimental evidence points to guanine as having the highest affinity of all the DNA bases for undergoing damage. In this study we use Car-Parrinello molecular dynamics (CPMD) in conjunction with traditional quantum chemical methods to research the possible mechanisms for the gas-phase damage of guanine in the presence of an OH radical. Our findings indicate that, for most of the sampled starting configurations, dehydrogenation of guanine (to yield guanine radical and water) is spontaneous and free energetically most favored at all hydrogen sites except at C8. Furthermore, through state-of-the-art analysis, we are able to separately track the nuclear and electronic rearrangement during the dehydrogenation reactions, and find examples of both concerted and stepwise abstraction of the proton and electron. We also find spontaneous hydroxylation at C8 and C4 in accordance with experimental findings. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Mundy, CJ (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. NR 46 TC 50 Z9 51 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 OCT 31 PY 2002 VL 106 IS 43 BP 10063 EP 10071 DI 10.1021/jp0212904 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608XW UT WOS:000178873900002 ER PT J AU McGrath, TE Diebold, GJ Bartels, DM Crowell, RA AF McGrath, TE Diebold, GJ Bartels, DM Crowell, RA TI Laser-initiated chemical reactions in carbon suspensions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID COLLOIDAL SUSPENSIONS; GENERATION; IRRADIATION; CAVITATION; PARTICLES AB We report on laser-initiated chemical reactions in colloidal carbon suspensions. Irradiation of carbon particles ranging in size from 13 to 75 nm in diameter suspended in water, toluene, and benzene with high power nanosecond, picosecond, and feratosecond laser pulses leads to the formation of a number of gaseous hydrocarbons as well as a series of liquid-phase products. In the product gas above irradiated carbon suspensions in water, H-2 and CO, the main reaction products of the carbon-steam reaction, and numerous hydrocarbons ranging from C-1-C-4 were detected. Irradiation of particulate carbon in toluene and benzene gave H-2 as the main gas product with small amounts Of C-1-C-3 hydrocarbons. Bibenzyl and biphenyl were found as the main liquid products produced in toluene and benzene suspensions, respectively, but with numerous polycyclic aromatic hydrocarbons in smaller concentrations. The amount of products generated by pulsed laser irradiation is shown to depend on particle size and concentration, as well as the laser fluence and pulse width. The chemical reactions reported take place under conditions characterized by extremely high temperatures and pressures of short duration. C1 Brown Univ, Dept Chem, Providence, RI 02912 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Diebold, GJ (reprint author), Brown Univ, Dept Chem, Providence, RI 02912 USA. NR 25 TC 15 Z9 15 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 OCT 31 PY 2002 VL 106 IS 43 BP 10072 EP 10078 DI 10.1021/jp0208135 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608XW UT WOS:000178873900003 ER PT J AU Samoilov, M Arkin, A Ross, J AF Samoilov, M Arkin, A Ross, J TI Signal processing by simple chemical systems SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PROTEIN-BASED MODEL; DICTYOSTELIUM-DISCOIDEUM; NETWORK THERMODYNAMICS; TIME-SERIES; OSCILLATIONS; CONSTRUCTION; KINETICS AB Signal processing is one of the most important system control mechanisms across a wide variety of functional devices and mechanisms from electronics to biology. The chemical reaction networks underlying the response of a cell to both externally and internally generated signals comprise an extraordinary real-time multivariate control problem. There: are two phenomena that exemplify the biological importance of chemical systems' response to oscillatory signals. One includes a number of important cases of differential cellular response to particular frequencies of periodic chemical signals. The most widespread example of this is the encoding of an external agonist concentration in the frequency of calcium ion concentration spiking inside certain eukaryotic cells. The second is based on the fact that, owing to the low concentrations and slow reaction rates often associated with, for example, the mechanisms of gene expression, a significant amount of fluctuation in protein production rates is to be expected. Thus, mechanisms that are essential for the life of the cell must be robust to these and other types of random noise in the environment as well as be able to filter relevant signals from the background successfully. We analyze a number of commonly occurring chemical reaction networks, "motifs" or "modules", for their response to periodic single- and multifrequency signals. We find that even very simple chemical reaction networks can be selectively responsive to specific frequency ranges of the input signals. The main results are that first, a general system of linear reactions with a single external oscillatory input signal always acts as a low-pass frequency filter. With more than one input at the same frequency, the system can also be made to, behave as a band-pass filter in a selected range but never as a high-pass one. Second, a class of bimolecular reaction mechanisms can behave as a band-pass filter, but the behavior is very sensitive to the kinetic parameters. Third, a class of excitable chemical systems can act as a robust band-pass filter. These results also suggest methods for controlling system behavior through its response to oscillatory inputs, for deducing chemical reaction mechanisms, and for estimating the associated rate constants from measurements of system responses to frequency-variable perturbations. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Howard Hughes Med Inst, Phys Biosci Div,Dept Bioengn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Howard Hughes Med Inst, Phys Biosci Div,Dept Chem, Berkeley, CA 94720 USA. RP Samoilov, M (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Arkin, Adam/A-6751-2008; OI Arkin, Adam/0000-0002-4999-2931; Samoilov, Michael/0000-0003-3559-5326 NR 37 TC 52 Z9 52 U1 1 U2 6 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 OCT 31 PY 2002 VL 106 IS 43 BP 10205 EP 10221 DI 10.1021/jp025846z PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608XW UT WOS:000178873900019 ER PT J AU Nguyen, KA Day, PN Pachter, R Tretiak, S Chernyak, V Mukamel, S AF Nguyen, KA Day, PN Pachter, R Tretiak, S Chernyak, V Mukamel, S TI Analysis of absorption spectra of zinc porphyrin, zinc meso-tetraphenylporphyrin, and halogenated derivatives SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; COMPACT EFFECTIVE POTENTIALS; MOLECULAR-ORBITAL THEORY; REAL-SPACE ANALYSIS; EXPONENT BASIS-SETS; ELECTRONIC EXCITATIONS; FREE-BASE; DIFFERENTIAL OVERLAP; PURPLE BACTERIA; INTERMEDIATE NEGLECT AB The absorption spectra of zinc porphyrin, zinc meso-tetraphenylporphyrin, and their beta-halogenated derivatives are calculated and analyzed using time-dependent density functional theory (TDDFT) and time-dependent Hartree-Fock theory based on the intermediate neglect differential overlap/spectroscopic approximation (TDHF-INDO/S) to obtain the origin of the spectral shifts in color and intensity. Analysis of the spectral shifts is carried out to account for the effects of phenyl, fluoro, chloro, and bromo substituents on the spectra. The spectroscopic trends predicted by TDHF-INDO/S compare well with the more accurate time-dependent density functional theory results and with available experimental data. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Rochester, Dept Chem, Rochester, NY 14627 USA. RP Nguyen, KA (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLPJ, Wright Patterson AFB, OH 45433 USA. RI Tretiak, Sergei/B-5556-2009; Chernyak, Vladimir/F-5842-2016 OI Tretiak, Sergei/0000-0001-5547-3647; Chernyak, Vladimir/0000-0003-4389-4238 NR 54 TC 54 Z9 54 U1 0 U2 17 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 OCT 31 PY 2002 VL 106 IS 43 BP 10285 EP 10293 DI 10.1021/jp020053y PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608XW UT WOS:000178873900027 ER PT J AU Zhan, CG Dixon, DA AF Zhan, CG Dixon, DA TI A density functional theory approach to the development of Q-e parameters for the prediction of reactivity in free-radical copolymerizations SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID Q-E SCHEME; VACUUM-ULTRAVIOLET REGION; CARBOXYLIC-ACID ESTERS; ALKALINE-HYDROLYSIS; REACTION PATHWAYS; ENERGY BARRIERS; WAVE-FUNCTIONS; PHOTOABSORPTION; MOLECULES; EXCHANGE AB The Q-e scheme was developed for the interpretation of the reactivity of a monomer containing a double bond in free-radical copolymerizations. This empirical scheme has proven to be remarkably useful and continues to be the only general reactivity scheme in use today. To develop a reliable computational approach for the theoretical prediction of the Q and e values of molecules whose experimental Q and e values have not been established, we have analyzed the Q-e approach to develop a computational approach to their prediction. We then performed density-functional theory (DFT) calculations on molecules whose experimental Q and e values are available to develop a set of correlation parameters for monomers without experimental values. It has been demonstrated that for a general choice of the Q and e values of the reference monomer that both parameters Q arid e should be dependent on the energetic properties of the free-radical reaction and the polar properties of the monomer and radical. To correlate the Q and e parameters with these properties, the overall quality of the calibrated correlation relationships should not be affected by the choice of the reference Q and e values. Satisfactory relationships have been found for the correlations of the Q-e parameters with DFT-calculated electronegativities and reaction free energies, suggesting that the electronegativity and reaction free energy determined by the DFT calculations reasonably reflect the polar and energetic properties, respectively, needed for Q-e parameter development. With the particular choice of the popularly used reference values of Q = 1.0 and e = -0.8 for styrene, the parameter e is dependent only on the calculated electronegativity, and the parameter Q is dominated by the calculated reaction free energy of the process of adding a radical to a C=C double bond. The explicit relationships obtained in this work can be used to predict unknown Q and e parameters based on DFT calculations. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dixon, DA (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, MS K1-83,POB 999, Richland, WA 99352 USA. NR 56 TC 25 Z9 26 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 31 PY 2002 VL 106 IS 43 BP 10311 EP 10325 DI 10.1021/jp020497u PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608XW UT WOS:000178873900030 ER PT J AU Kupka, T Ruscic, B Botto, RE AF Kupka, T Ruscic, B Botto, RE TI Toward Hartree-Fock- and density functional complete basis-set-predicted NMR parameters SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MAGNETIC SHIELDING TENSORS; INCLUDING ATOMIC ORBITALS; CORRELATED MOLECULAR CALCULATIONS; AB-INITIO CALCULATIONS; C-13 CHEMICAL-SHIFTS; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; GAS-PHASE; BENCHMARK CALCULATIONS; PERTURBATION-THEORY AB The molecular and spectroscopic parameters calculated using the hybrid density functional B3PW91 are reported for a model set of compounds composed of H-2, N-2, NH3, CH4, C2H4, HCN, CH3CN, and H2O. An estimation of the DFT and Hartree-Fock complete basis-set limit (CBS) energy and NMR parameters from the 2- (3-) point exact fit versus least-squares fit (NLLSQ) was obtained with the cc-pVxZ and aug-cc-pVxZ basis sets (x = D, T, Q, 5, 6). A marginally faster convergence of the fitted parameters obtained with core-valence basis sets cc-pCVxZ and aug-cc-pCVxZ was noticed. The Hartree-Fock-predicted CBS heavy-atom isotropic shieldings of the model molecules, as compared with those of DFT, were closer to experiment. It was also shown that GIAO MP2-predicted NMR parameters yield the best agreement with those obtained from experiment and benchmark calculations. As. support for experimental studies, the CBS approach of calculating accurate nuclear shieldings of larger molecules is proposed. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM rbotto@anl.gov RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 92 TC 49 Z9 49 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 31 PY 2002 VL 106 IS 43 BP 10396 EP 10407 DI 10.1021/jp020987m PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608XW UT WOS:000178873900039 ER PT J AU Meziani, MJ Rollins, HW Allard, LF Sun, YP AF Meziani, MJ Rollins, HW Allard, LF Sun, YP TI Protein-protected nanoparticles from rapid expansion of supercritical solution into aqueous solution SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CARBON-DIOXIDE MICROEMULSION; BOVINE SERUM-ALBUMIN; SILVER NANOPARTICLES; MACROSCOPIC MATERIALS; REVERSE MICELLES; FLUID SOLUTIONS; NANOCRYSTALS; DNA; COPPER; WATER AB Nanocrystalline silver particles were prepared via a supercritical fluid processing technique RESOLV (Rapid Expansion of a Supercritical Solution into a Liquid SOLVent) coupled with chemical reduction. The preparation involved the rapid expansion of a supercritical ammonia solution of silver nitrate into an ambient solution that contained sodium borohydride or hydrazine as reducing agent and poly(N-vinyl-2-pyrrolidone) (PVP) or bovine serum albumin (BSA) protein as the protection agent for the resulting nanoparticle suspension. The nanoparticles were characterized using UV/vis absorption, X-ray powder diffraction, and transmission electron microscopy methods. The results show that the BSA protein-protected Ag nanoparticles are much larger than those obtained with,PVP as protection agent under otherwise the same experimental conditions but still maintain relatively narrow size distributions. Mechanistic implications of the results are discussed. C1 Clemson Univ, Dept Chem, Clemson, SC 29634 USA. Clemson Univ, Howard L Hunter Chem Lab, Ctr Adv Engn Fibers & Films, Clemson, SC 29634 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Sun, YP (reprint author), Clemson Univ, Dept Chem, Clemson, SC 29634 USA. RI Rollins, Harry/B-6327-2017 OI Rollins, Harry/0000-0002-3926-7445 NR 46 TC 53 Z9 56 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 31 PY 2002 VL 106 IS 43 BP 11178 EP 11182 DI 10.1021/jp0212747 PG 5 WC Chemistry, Physical SC Chemistry GA 608XY UT WOS:000178874100017 ER PT J AU Cho, H Shepson, PB Barrie, LA Cowin, JP Zaveri, R AF Cho, H Shepson, PB Barrie, LA Cowin, JP Zaveri, R TI NMR investigation of the quasi-brine layer in ice/brine mixtures SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; SALT-WATER ICE; POLAR SUNRISE; OZONE DESTRUCTION; BOUNDARY-LAYER; SURFACE; CHEMISTRY; BROMINE AB We report the study of a liquidlike phase that is found in dilute NaCl aqueous solutions frozen at temperatures below the liquid-to-solid-phase transition temperatures of H2O and NaCl.2H(2)O. There is strong evidence that heterogeneous reactions of gases with halides in liquid layers on ice are the source of halogen radicals that destroy the lower tropospheric ozone, and a subeutectic brine phase is thus of particular relevance to discussions of atmospheric composition and its dependence on the chemistry of polar marine ice and snow. The fractions and concentrations of water and NaCl in this subeutectic quasi-liquid phase were measured by H-1 and Na-23 NMR spectroscopy, and the experimental results compared to predictions derived from an equilibrium thermodynamic analysis. The temperature dependence of the salt concentration is well-described by the equilibrium theory for temperature ranges where ideal solution behavior holds; for lower temperatures, where the observed salt concentration increases and deviations from ideality emerge, the predicted concentrations are generally higher than experimental measurements. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. RP Cho, H (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Shepson, Paul/E-9955-2012; OI Zaveri, Rahul/0000-0001-9874-8807 NR 38 TC 126 Z9 128 U1 2 U2 25 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 OCT 31 PY 2002 VL 106 IS 43 BP 11226 EP 11232 DI 10.1021/jp020449+ PG 7 WC Chemistry, Physical SC Chemistry GA 608XY UT WOS:000178874100024 ER PT J AU Genson, KL Vaknin, D Villacencio, O McGrath, DV Tsukruk, VV AF Genson, KL Vaknin, D Villacencio, O McGrath, DV Tsukruk, VV TI Microstructure of amphiphilic monodendrons at the air-water interface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID X-RAY-DIFFRACTION; SPHERICAL SUPRAMOLECULAR DENDRIMERS; LANGMUIR MONOLAYERS; OCTADECANOL MONOLAYERS; STRUCTURAL-ANALYSIS; PHASE-TRANSITIONS; MOLECULAR-MODEL; LIQUID-CRYSTALS; FILMS; ACID AB Grazing incident X-ray diffraction and X-ray reflectivity have been performed on Langmuir monolayers of low generation monodendrons containing a crown-ether polar group, azobenzene spacer, and varying number of peripheral alkyl chains of 1, 2, 4, and 8. We observe that the cross-sectional mismatch between the bulky polar head and the alkyl tails has a profound effect on the local ordering of the alkyl tails. It is found that the alkyl chains in a single-tail molecule are significantly tilted away from the surface normal. The tilt is eliminated in molecules with two or more alkyl chains where the cross-sectional mismatch is in favor of the peripheral tails. The molecule with one fail possesses a supercell orthorhombic packing caused by structural nonequivalency on the neighboring tails. The two- and four-tail molecules form a mixed structure best described by a quasi-hexagonal unit cell, and the eight-tail molecule forms a more stable hexagonal unit cell. Peripheral tails for these molecules are in standing-off orientation. We suggest that the steric constraints cause lower correlations and a staggered packing structure of monolayers from the eight-tail molecule. We suggest that branching alkyl tails off the same phenyl ring and the presence of the phenyl rings in the vicinity of the branching are limiting factors on the chain packing at the air-water interface in monodendrons with multiple peripheral tails. We conclude that a significant portion of the molecules is submerged in the water subphase and possesses a "kink" shape. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. RP Tsukruk, VV (reprint author), Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RI McGrath, Dominic/A-7675-2012; Vaknin, David/B-3302-2009 OI Vaknin, David/0000-0002-0899-9248 NR 39 TC 26 Z9 26 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 31 PY 2002 VL 106 IS 43 BP 11277 EP 11284 DI 10.1021/jp026244i PG 8 WC Chemistry, Physical SC Chemistry GA 608XY UT WOS:000178874100031 ER PT J AU Zschiesche, D Schramm, S Schaffner-Bielich, J Stocker, H Greiner, W AF Zschiesche, D Schramm, S Schaffner-Bielich, J Stocker, H Greiner, W TI Particle ratios at RHIC: Effective hadron masses and chemical freeze-out SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; QUARK-GLUON PLASMA; PHASE-TRANSITION; NUCLEAR COLLISIONS; STRANGE HADRONS; DYNAMICS; MULTIPLICITIES; HADRONIZATION; PARAMETERS; DEPENDENCE AB dThe measured particle ratios in central heavy-ion collisions at RHIC-BNL are investigated within a chemical and thermal equilibrium chiral SU(3) sigma-omega approach. The commonly adopted noninteracting gas calculations yield temperatures close to or above the critical temperature for the chiral phase transition, but without taking into account any interactions. Contrary, the chiral SU(3) model predicts temperature and density dependent effective hadron masses and effective chemical potentials in the medium and a transition to a chirally restored phase at high temperatures or chemical potentials. Three different parametrizations of the model, which show different types of phase transition behaviour, are investigated. We show that if a chiral phase transition occured in those collisions, "freezing" of the relative hadron abundances in the symmetric phase is excluded by the data. Therefore, either very rapid chemical equilibration must occur in the broken phase, or the measured hadron ratios are the outcome of the dynamical symmetry breaking. Furthermore, the extracted chemical freeze-out parameters differ considerably from those obtained in simple noninteracting gas calculations. In particular, the three models yield up to 35 MeV lower temperatures than the free gas approximation. The in-medium masses turn out to differ up to 150 MeV from their vacuum values. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Inst Theoret Phys, D-60054 Frankfurt, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Nantes, CNRS, Ecole Mines Nantes, Lab Phys Subatom & Technol Associees,IN2P3, F-44072 Nantes 03, France. RP Zschiesche, D (reprint author), Inst Theoret Phys, Robert Mayer Str 8-10, D-60054 Frankfurt, Germany. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 44 TC 62 Z9 63 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 OCT 31 PY 2002 VL 547 IS 1-2 BP 7 EP 14 AR PII S0370-2693(02)02736-3 DI 10.1016/S0370-2693(02)02736-3 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 612XN UT WOS:000179100900002 ER PT J AU Dumitru, A Jalilian-Marian, J AF Dumitru, A Jalilian-Marian, J TI Scattering of gluons from the color glass condensate SO PHYSICS LETTERS B LA English DT Article ID WILSON RENORMALIZATION-GROUP; WEIZSACKER-WILLIAMS FIELDS; NUCLEUS-NUCLEUS COLLISIONS; DEEP-INELASTIC-SCATTERING; LOW X PHYSICS; TRANSVERSE-MOMENTUM; HIGH-DENSITY; SATURATION; RADIATION; EVOLUTION AB We prove that the inclusive single-gluon production cross section for a hadron colliding with a high-density target factorizes into the gluon distribution function of the projectile, defined as usual within the DGLAP collinear approximation, times the cross section for scattering of a single gluon on the strong classical color field of the target. We then derive the gluon-proton (nucleus) inelastic cross section and show that it is (up to logarithms) infrared safe and that it grows slowly with center of mass energy. Furthermore, we discuss jet transverse momentum broadening for the case of nuclear targets. We show that in the saturation regime, in contrast to the perturbative regime, the width of the transverse momentum distribution is infrared finite and grows rapidly with energy and rapidity. In both regimes, however, transverse momentum broadening exhibits the same A dependence. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Nucl Theory Grp, Upton, NY 11973 USA. RP Dumitru, A (reprint author), Brookhaven Natl Lab, Dept Phys, Nucl Theory Grp, Upton, NY 11973 USA. NR 36 TC 67 Z9 67 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 OCT 31 PY 2002 VL 547 IS 1-2 BP 15 EP 20 AR PII S0370-2693(02)02709-0 DI 10.1016/S0370-2693(02)02709-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 612XN UT WOS:000179100900003 ER PT J AU Kharzeev, D Levin, E Tuchin, K AF Kharzeev, D Levin, E Tuchin, K TI Classical gluodynamics in curved space-time and the soft pomeron SO PHYSICS LETTERS B LA English DT Article ID HOLE HORIZON FLUCTUATIONS; COMPACT DIMENSIONS; SMALL-X; QCD; SCATTERING; COLLISIONS; ANOMALIES; INTERCEPT; ADS/CFT; QUARK AB QCD at the classical level possesses scale invariance which is broken by quantum effects. This "dimensional transmutation" phenomenon can be mathematically described by formulating classical gluodynamics in a curved, conformally flat, space-time with non-vanishing cosmological constant. We study QCD high-energy scattering in this theory. We find that the properties of the scattering amplitude at small momentum transfer are determined by the energy density of vacuum fluctuations. The approach gives rise to the power growth of the total hadron-hadron cross section with energy, i.e., the pomeron. The intercept of the pomeron and the multiplicity of produced particles are evaluated. We also speculate about a possible link between conformal anomaly and TeV scale quantum gravity. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. Tel Aviv Univ, Sch Phys & Astron, HEP Dept, IL-69978 Ramat Aviv, Israel. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. RP Kharzeev, D (reprint author), Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. NR 52 TC 16 Z9 16 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 OCT 31 PY 2002 VL 547 IS 1-2 BP 21 EP 30 AR PII S0370-2693(02)02729-6 DI 10.1016/S0370-2693(02)02729-6 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 612XN UT WOS:000179100900004 ER PT J AU Castillo, P AF Castillo, P TI Performance of discontinuous Galerkin methods for elliptic PDEs SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE finite element; discontinuous Galerkin methods; conditioning of stiffness matrix ID FINITE-ELEMENT METHOD; DIFFUSION-PROBLEMS; EQUATIONS AB In this paper, we compare the performance of several discontinuous Galerkin (DG) methods for elliptic partial differential equations (PDEs) on a model problem. Theoretical estimates of the condition number of the stiffness matrix are given for DG methods whose bilinear form is symmetric and which are shown to be numerically sharp. Then the efficiency of the methods in the computation of both the potential and its gradient is tested on unstructured triangular meshes. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Castillo, P (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, 7000 East Ave,POB 808, Livermore, CA 94551 USA. NR 24 TC 65 Z9 71 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD OCT 31 PY 2002 VL 24 IS 2 BP 524 EP 547 AR PII S1064827501388339 DI 10.1137/S1064827501388339 PG 24 WC Mathematics, Applied SC Mathematics GA 612FM UT WOS:000179063900009 ER PT J AU Gordon, SJ Brady, PV AF Gordon, SJ Brady, PV TI In situ determination of long-term basaltic glass dissolution in the unsaturated zone SO CHEMICAL GEOLOGY LA English DT Article DE weathering; basaltic glass; El Malpais; porosity ID NUCLEAR WASTE-GLASS; ORGANIC-ACIDS; ATMOSPHERIC CO2; SILICATE DISSOLUTION; SURFACE-CHEMISTRY; LOW-TEMPERATURE; VOLCANIC GLASS; RATES; MINERALS; 25-DEGREES-C AB Maximum in situ weathering rates of basaltic glass measured at the El Malpais National Monument in New Mexico are on the order of 2-5 X 10(-19) mol/cm(2)/s. Rates were calculated from backscattered electron (BSE) imaging of weathered porosity and are equivalent to 1.7-5% of the surface per 1000 years. Weathering is independent of glass composition but appears to increase with flow elevation at El Malpais. Measured rates represent weathering over 3000 years and are substantially lower than glass dissolution rates measured in the laboratory over much shorter time spans. Basaltic glass is a close chemical analogue to glass hosts proposed for encapsulation of high-level nuclear wastes. Radionuclide release rates predicted from the basis of in situ field rates are substantially less than those predicted from short-term laboratory experiments. (C) 2002 Elsevier Science B.V. All rights reserved. C1 USAF Acad, DFEG, Dept Econ & Geog, HQ, Colorado Springs, CO 80840 USA. Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. RP Gordon, SJ (reprint author), USAF Acad, DFEG, Dept Econ & Geog, HQ, 2354 Fairchild Dr,Suite 6K110, Colorado Springs, CO 80840 USA. NR 52 TC 9 Z9 9 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD OCT 30 PY 2002 VL 190 IS 1-4 BP 113 EP 122 AR PII S0009-2541(02)00113-4 DI 10.1016/S0009-2541(02)00113-4 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 617FB UT WOS:000179349900007 ER PT J AU Minissale, A Kerrick, DM Magro, G Murrell, MT Paladini, M Rihs, S Sturchio, NC Tassi, F Vaselli, O AF Minissale, A Kerrick, DM Magro, G Murrell, MT Paladini, M Rihs, S Sturchio, NC Tassi, F Vaselli, O TI Geochemistry of Quaternary travertines in the region north of Rome (Italy): structural, hydrologic and paleoclimatic implications SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE travertine; Italy; paleoclimatology; paleohydrology ID AQUEOUS-SOLID GEOCHEMISTRY; YELLOWSTONE-NATIONAL-PARK; HOT-SPRING TRAVERTINES; CHEMICAL-COMPOSITION; DEPOSITIONAL FACIES; CARBON-DIOXIDE; RAPOLANO TERME; ANGEL TERRACE; CO2 EMISSION; GAS AB In the Tyrrhenian region of central Italy, late Quaternary fossil travertines are widespread along two major regional structures: the Tiber Valley and the Ancona-Anzio line. The origin and transport of spring waters from which travertines precipitate are elucidated by chemical and isotopic studies of the travertines and associated thermal springs and gas vents. There are consistent differences in the geochemical and isotopic signatures of thermal spring waters, gas vents and present and fossil travertines between east and west of the Tiber Valley. West of the Tiber Valley, delta(13)C of CO2 discharged from gas vents and delta(13)C of fossil travertines are higher than those to the east. To the west the travertines have higher strontium contents, and gases emitted from vents have higher He-3/He-4 ratios and lower N-2 contents, than to the east. Fossil travertines to the west have characteristics typical of thermogene (thermal spring) origin, whereas those to the east have meteogene (low-temperature) characteristics (including abundant plant casts and organic impurities). The regional geochemical differences in travertines and fluid compositions across the Tiber Valley are interpreted with a model of regional fluid flow. The regional Mesozoic limestone aquifer is recharged in the main axis of the Apennine chain, and the groundwater flows westward and is discharged at springs. The travertine-precipitating waters east of the Tiber Valley have shallower flow paths than those to the west. Because of the comparatively short fluid flow paths and low (normal) heat flow, the groundwaters to the east of the Tiber Valley are cold and have CO2 isotopic signatures, indicating a significant biogenic contribution acquired from soils in the recharge area and limited deeply derived CO2. In contrast, spring waters west of the Tiber Valley have been conductively heated during transit in these high heat-flow areas and have incorporated a comparatively large quantity of CO2 derived from decarbonation of limestone. The elevated strontium content of the thermal spring water west of the Tiber Valley is attributed to deep circulation and dissolution of a Triassic evaporite unit that is stratigraphically beneath the Mesozoic limestone. U-series age dates of fossil travertines indicate three main periods of travertine formation (ka): 220-240, 120-140 and 60-70. Based on the regional flow model correlating travertine deposition at thermal springs and precipitation in the recharge area, we suggest that pluvial activity was enhanced during these periods. Our study suggests that travertines preserve a valuable record of paleofluid composition and paleoprecipitation and are thus useful for reconstructing paleohydrology and paleoclimate. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CNR, Italian Council Res, Inst Geosci & Earth Resources, Sect Florence, I-50121 Florence, Italy. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. CNR, Italian Council res, Inst Geosci & Earth Resources, I-56127 Pisa, Italy. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ Florence, Dept Earth Sci, I-50121 Florence, Italy. Univ Strasbourg 1, Ctr Geochim Surface, F-67084 Strasbourg, France. Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. RP Minissale, A (reprint author), CNR, Italian Council Res, Inst Geosci & Earth Resources, Sect Florence, Via Pira 4, I-50121 Florence, Italy. RI Tassi, Franco/G-7857-2012; magro, gabriella/J-6327-2012 OI Tassi, Franco/0000-0002-3319-4257; magro, gabriella/0000-0002-5525-0176 NR 73 TC 82 Z9 83 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT 30 PY 2002 VL 203 IS 2 BP 709 EP 728 AR PII S0012-821X(02)00875-0 DI 10.1016/S0012-821X(02)00875-0 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 612CU UT WOS:000179057600009 ER PT J AU Campbell, CG Ghodrati, M Garrido, F AF Campbell, CG Ghodrati, M Garrido, F TI Using time-domain reflectometry to characterize shallow solute transport in an oak woodland hillslope in northern California, USA SO HYDROLOGICAL PROCESSES LA English DT Article DE soil solute transport; hillslope runoff; hydrological pathways; measurement technology; time-domain reflectometry; tracers; electrical conductivity ID PREFERENTIAL FLOW; UNDISTURBED SOIL; FORESTED CATCHMENT; WATER-CONTENT; POROUS-MEDIA; FIELD SOIL; MACROPORES; INFILTRATION; CALIBRATION; PATHWAYS AB The natural heterogeneity of water and solute movement in hillslope soils makes it difficult to accurately characterize the transport of surface-applied pollutants without first gathering spatially distributed hydrological data. This study examined the application of time-domain reflectometry (TDR) to measure solute transport in hillslopes. Three different plot designs were used to examine the transport of a conservative tracer in the first 50 cm of a moderately sloping soil. In the first plot, which was designed to examine spatial variability in vertical transport in a 1.2 m(2) plot, a single probe per meter was found to adequately characterize vertical solute travel times. In addition, a dye and excavation study in this plot revealed lateral preferential flow in small macropores and a transport pattern where solute is focused vertically into preferential flow pathways. The bypass flow delivers solute deeper in the soil, where lateral flow occurs. The second plot, designed to capture both vertical and lateral flow, provided additional evidence confirming the flow patterns identified in the excavation of the first plot. The third plot was designed to examine lateral flow and once again preferential flow of the tracer was observed. In one instance rapid solute transport in this plot was estimated to occur in as little as 3% of the available pore space. Finally, it was demonstrated that the soil anisotropy, although partially responsible for lateral subsurface transport, may also homogenize the transport response across the hillslope by decreasing vertical solute spreading. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, Berkeley, CA 94720 USA. RP Campbell, CG (reprint author), Lawrence Livermore Natl Lab, Water Guidance & Monitoring Grp, POB 808,L-627, Livermore, CA 94551 USA. RI Garrido, Fernando/H-9868-2012; Garrido, Fernando/J-5602-2014 NR 45 TC 5 Z9 5 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD OCT 30 PY 2002 VL 16 IS 15 BP 2921 EP 2940 DI 10.1002/hyp.1047 PG 20 WC Water Resources SC Water Resources GA 607GU UT WOS:000178784400001 ER PT J AU Granite, EJ Pennline, HW AF Granite, EJ Pennline, HW TI Photochemical removal of mercury from flue gas SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SORBENTS AB Photochemical reactions of mercury with various constituents in flue gas produced by burning coal could be an attractive alternative to dry sorbent- or wet scrubber-based processes for mercury control. The sensitized oxidation of elemental mercury using 253.7-nm ultraviolet radiation has been extensively studied. The photochemistry of elemental mercury in simulated flue gases was examined using quartz flow reactors. Mercury-containing simulated flue gases at temperatures between 80 and 350 degreesF were irradiated with 253.7-nm ultraviolet light. Results are presented for the photochemical removal of elemental mercury from simulated flue gases, as well as from nitrogen mixtures that contain oxygen, water vapor, or nitrogen oxide. Optimization of the process parameters, including light intensity, is discussed. The implications of photochemical oxidation of mercury with respect to direct ultraviolet irradiation of flue gas for mercury control, analysis of gases for mercury content, and atmospheric reactions are discussed. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Granite, EJ (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 60 TC 171 Z9 175 U1 6 U2 41 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD OCT 30 PY 2002 VL 41 IS 22 BP 5470 EP 5476 DI 10.1021/ie020251b PG 7 WC Engineering, Chemical SC Engineering GA 608NU UT WOS:000178853400019 ER PT J AU Halpern, MB Obers, NA AF Halpern, MB Obers, NA TI Two large examples in orbifold theory: Abelian orbifolds and the charge conjugation orbifold on su(n) SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article DE conformal field theory; string theory; affine Lie algebra; orbifolds ID GENERAL VIRASORO CONSTRUCTION; PION-QUARK MODEL; VERTEX OPERATORS; 2 FACES; ALGEBRA; DUALITY AB Recently the operator algebra and twisted vertex operator equations were given for each sector of all WZW orbifolds, and a set of twisted KZ equations for the WZW permutation orbifolds were worked out as a large example. In this companion paper we report two further large examples of this development. In the first example we solve the twisted vertex operator equations in an Abelian limit to obtain the twisted vertex operators and correlators of a large class of Abelian orbifolds. In the second example, the twisted vertex operator equations are applied to obtain a set of twisted KZ equations for the (outer-automorphic) charge conjugation orbifold on su(n greater than or equal to 3). C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Utrecht, Spinoza Inst, NL-3584 CE Utrecht, Netherlands. Univ Utrecht, Inst Theoret Phys, NL-3584 CE Utrecht, Netherlands. Univ Amsterdam, Inst Theoret Phys, NL-1018 XE Amsterdam, Netherlands. Niels Bohr Inst, DK-2100 Copenhagen 0, Denmark. RP Halpern, MB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Phys, Berkeley, CA 94720 USA. RI Obers, Niels/D-1377-2014 OI Obers, Niels/0000-0003-4947-8526 NR 24 TC 21 Z9 21 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 OCT 30 PY 2002 VL 17 IS 27 BP 3897 EP 3961 DI 10.1142/S0217751X02010832 PG 65 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 606WQ UT WOS:000178758000004 ER PT J AU Morgan, DM Dong, JJ Jacob, J Lu, K Apkarian, RP Thiyagarajan, P Lynn, DG AF Morgan, DM Dong, JJ Jacob, J Lu, K Apkarian, RP Thiyagarajan, P Lynn, DG TI Metal switch for amyloid formation: Insight into the structure of the nucleus SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ALZHEIMER A-BETA; PEPTIDE; ZINC; BETA-AMYLOID(10-35); DISEASE; BINDING; FIBRILLOGENESIS; CONFORMATION; AGGREGATION; PROTEIN C1 Argonne Natl Lab, Argonne, IL 60439 USA. Emory Univ, Ctr Anal SupraMol Self Assemblies, Dept Chem, Atlanta, GA 30322 USA. Emory Univ, Ctr Anal SupraMol Self Assemblies, Dept Biol, Atlanta, GA 30322 USA. Univ Chicago, Chicago, IL 60637 USA. RP Thiyagarajan, P (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. FU NCRR NIH HHS [RR12723] NR 22 TC 52 Z9 56 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 30 PY 2002 VL 124 IS 43 BP 12644 EP 12645 DI 10.1021/ja0273086 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 607LE UT WOS:000178792400005 PM 12392395 ER PT J AU Blas, JR Marquez, M Sessler, JL Luque, FJ Orozco, M AF Blas, JR Marquez, M Sessler, JL Luque, FJ Orozco, M TI Theoretical study of anion binding to calix[4]pyrrole: the effects of solvent, fluorine substitution, cosolute, and water traces SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY STRUCTURE; INTERACTION POTENTIALS; MOLECULAR-DYNAMICS; RECOGNITION; SENSORS; CALIXPYRROLE; COMPLEXATION; SIMULATIONS; PROTEINS; SYSTEMS AB The binding of different anions to calix[4]pyrrole has been studied by means of molecular dynamics coupled to thermodynamic integration calculations. The effect of different apolar solvents, octafluoro substitution, and the change in binding free energy derived from the presence of cosolute and water traces (the hydrated salt used to introduce the anion in the solution) were examined. Calculations allow us to rationalize the differential binding of ions to calix[4]pyrrole and octafluorocalix[4]pyrrole as well as to predict the behavior in new solvents for which experimental data are not available yet. It is found that both calix[4]pyrrole and octafluorocalix[4]pyrrole have a dramatic preference for F- in the gas phase and pure aprotic solvents, but the situation can change dramatically in protic solvents or in the presence of the hydrated cation which is used as cosolute of the anion. Overall, our results provide interesting clues for a better understanding of the process detected experimentally as "binding". C1 Univ Barcelona, Dept Bioquim & Biol Mol, Fac Quim, E-08028 Barcelona, Spain. Los Alamos Natl Lab, Dept Chem Sci & Technol, Los Alamos, NM 87545 USA. Kraft Gen Foods Inc, Res & Dev, Nanotechnol Lab, Glenview, IL 60025 USA. Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. Univ Texas, Inst Cell & Mol Biol, Austin, TX 78712 USA. Univ Barcelona, Fac Farm, Dept Fisicoquim, E-08028 Barcelona, Spain. RP Luque, FJ (reprint author), Univ Barcelona, Dept Bioquim & Biol Mol, Fac Quim, Marti & Franques 1, E-08028 Barcelona, Spain. RI Luque, F. Javier/L-9652-2014; OI Luque, F. Javier/0000-0002-8049-3567; Orozco Lopez, Modesto/0000-0002-8608-3278 FU NIGMS NIH HHS [GM 58906] NR 52 TC 59 Z9 59 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 30 PY 2002 VL 124 IS 43 BP 12796 EP 12805 DI 10.1021/ja020318m PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 607LE UT WOS:000178792400036 PM 12392426 ER PT J AU Schekochihin, AA Cowley, SC Hammett, GW Maron, JL McWilliams, JC AF Schekochihin, AA Cowley, SC Hammett, GW Maron, JL McWilliams, JC TI A model of nonlinear evolution and saturation of the turbulent MHD dynamo SO NEW JOURNAL OF PHYSICS LA English DT Article ID TANGLED MAGNETIC-FIELDS; MAGNETOHYDRODYNAMIC TURBULENCE; INVERSE CASCADE; THERMAL CONDUCTION; SIMULATIONS; GALAXIES; FLOWS; CONSEQUENCES; ISOTROPY; CLUSTERS AB The growth and saturation of magnetic field in conducting turbulent media with large magnetic Prandtl numbers are investigated. This regime is very common in low-density hot astrophysical plasmas. During the early (kinematic) stage, weak magnetic fluctuations grow exponentially and concentrate at the resistive scale, which lies far below the hydrodynamic viscous scale. The evolution becomes nonlinear when the magnetic energy is comparable to the kinetic energy of the viscous-scale eddies. A physical picture of the ensuing nonlinear evolution of the MHD dynamo is proposed. Phenomenological considerations are supplemented with a simple Fokker-Planck model of the nonlinear evolution of the magnetic-energy spectrum. It is found that, while the shift of the bulk of the magnetic energy from the subviscous scales to the velocity scales may be possible, it occurs very slowly-at the resistive, rather than dynamical, timescale (for galaxies, this means that the generation of large-scale magnetic fields cannot be explained by this mechanism). The role of Alfvenic motions and the implications for the fully developed isotropic MHD turbulence are discussed. C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Plasma Phys Grp, London SW7 2BW, England. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90095 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Plasma Phys Grp, Prince Consort Rd, London SW7 2BW, England. EM a.schekochihin@ic.ac.uk; steve.cowley@ic.ac.uk; hammett@princeton.edu; maron@tapir.caltech.edu; jcm@atmos.ucla.edu RI Schekochihin, Alexander/C-2399-2009; Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 60 TC 62 Z9 62 U1 0 U2 3 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 OCT 30 PY 2002 VL 4 AR 84 DI 10.1088/1367-2630/4/1/384 PG 22 WC Physics, Multidisciplinary SC Physics GA 610PW UT WOS:000178970200001 ER PT J AU Cinco, RM Holman, KLM Robblee, JH Yano, J Pizarro, SA Bellacchio, E Sauer, K Yachandra, VK AF Cinco, RM Holman, KLM Robblee, JH Yano, J Pizarro, SA Bellacchio, E Sauer, K Yachandra, VK TI Calcium EXAFS establishes the Mn-Ca cluster in the oxygen-evolving complex of photosystem II SO BIOCHEMISTRY LA English DT Article ID X-RAY-ABSORPTION; PHOTOSYNTHETIC WATER OXIDATION; MANGANESE CLUSTER; EVOLUTION ACTIVITY; HIGHER-PLANTS; SPECTROSCOPY; SPINACH; MEMBRANES; SITE; BINDING AB The proximity of Ca to the Mn cluster of the photosynthetic water-oxidation complex is, demonstrated by X-ray absorption spectroscopy. We have collected EXAFS data at the Ca K-edge using active PS 11 membrane samples that contain approximately 2 Ca per 4 Mn. These samples are much less perturbed than previously investigated Sr-substituted samples, which were prepared after Ca depletion. The new Ca EXAFS clearly shows backscattering from Mn at 3.4 Angstrom, a distance that agrees with that surmised from previously recorded Mn EXAFS. This result is also consistent with earlier related experiments at the Sr K-edge, using samples that contained functional Sr, that show Mn is similar to3.5 Angstrom distant from Sr. The totality of the evidence clearly advances the notion that the catalytic center of oxygen evolution is a Mn-Ca heteronuclear cluster. C1 Lawrence Berkeley Natl Lab, Melvin Calvin Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Yachandra, VK (reprint author), Lawrence Berkeley Natl Lab, Melvin Calvin Lab, Phys Biosci Div, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM 55302, R01 GM055302, R56 GM055302] NR 62 TC 108 Z9 108 U1 0 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 29 PY 2002 VL 41 IS 43 BP 12928 EP 12933 DI 10.1021/bi026569p PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 607LM UT WOS:000178793100005 PM 12390018 ER PT J AU Hao, B Isaza, C Arndt, J Soltis, M Chan, MK AF Hao, B Isaza, C Arndt, J Soltis, M Chan, MK TI Structure-based mechanism of O-2 sensing and ligand discrimination by the FixL heme domain of Bradyrhizobium japonicum SO BIOCHEMISTRY LA English DT Article ID OXYGEN SENSOR FIXL; RHIZOBIUM-MELILOTI; KINASE-ACTIVITY; CRYSTAL-STRUCTURE; PAS DOMAINS; PROTEIN; IRON; MYOGLOBIN; BINDING; PORPHYRINS AB Structures of the Bradyrhizobium japonicum FixL heme domain have been determined in the absence and presence of specific ligands to elucidate the detailed features of its O-2 sensing mechanism. The putative roles of spin-state and steric hindrance were evaluated by the structure determination of, ferrous CO-bound BjFixLH and correlating its features with other ligand-bound structures. As found for NO-BjFixLH, no protein conformational change was observed in CO-BjFixLH, suggesting a more complicated mechanism than solely spin state or ligand sterics. To evaluate the role of oxidation state, the structure of the ferrous deoxy-BjFixLH was determined. The structure of deoxy-BjFixLH was found to be virtually identical to the structure of the ferric met-BjFixLH. The role of hydrogen bonding of substrates to a heme-pocket water was evaluated by determining the structure of BjFixLH bound to 1-methyl-imidazole that cannot form a hydrogen bond with this water. In this case, the heme-mediated conformational change was observed, limiting the potential importance of this interaction. Finally, the structure of cyanomet-BjFixLH was revisited to rule out concerns regarding the partial occupancy of the cyanide ligand in a previous structure. In the revised structure, Arg 220 was found to move into the heme pocket to form a hydrogen bond to the bound cyanide ligand. The implications of these results on FixL's sensing mechanism are discussed. C1 Ohio State Univ, Dept Biochem, Columbus, OH 43210 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Ohio State Univ, Ohio State Biophys Program, Columbus, OH 43210 USA. Stanford Univ, Stanford Synchrotron Res Lab, SLAC, Stanford, CA 94309 USA. RP Chan, MK (reprint author), Ohio State Univ, Dept Biochem, 484 W 12th Ave, Columbus, OH 43210 USA. FU NCRR NIH HHS [RR07707] NR 35 TC 95 Z9 95 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 29 PY 2002 VL 41 IS 43 BP 12952 EP 12958 DI 10.1021/bi020144l PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 607LM UT WOS:000178793100008 PM 12390021 ER PT J AU Barrera, A Fang, XW Jacob, J Casey, E Thiyagarajan, P Pan, T AF Barrera, A Fang, XW Jacob, J Casey, E Thiyagarajan, P Pan, T TI Dimeric and monomeric Bacillus subtilis RNase P holoenzyme in the absence and presence of pre-tRNA substrates SO BIOCHEMISTRY LA English DT Article ID RIBONUCLEASE-P; ESCHERICHIA-COLI; PROTEIN-COMPONENT; RIBONUCLEOPROTEIN ENZYME; CATALYTIC EFFICIENCY; SEQUENCE; RIBOZYME; DOMAIN; RECOGNITION; SUBUNIT AB Ribonuclease P (RNase P) is a ribonucleoprotein enzyme that catalyzes the 5' maturation of tRNA precursors. The bacterial RNase P holoenzyme is composed of a large, catalytic RNA and a small protein. Our previous work showed that Bacillus subtilis RNase P forms a specific "dimer" that contains two RNase P RNA and two RNase P protein subunits in the absence of substrate. We investigated the equilibrium and the structure of the dimeric and the monomeric holoenzyme in the absence and presence of substrates by synchrotron small-angle X-ray scattering, 3' autolytic processing, and hydroxyl, radical protection. In the absence of substrate, the dimer-monomer equilibrium is sensitive to monovalent ions and the total holoenzyme concentration. At 0.1 M NH4Cl, formation of the dimer is strongly favored, whereas at 0.8 M NH4Cl, the holoenzyme is a monomer. Primary hydroxyl radical protection in the dimer is located in the specificity domain, or domain 1, of the RNase P RNA. The ES complex with a substrate containing a single tRNA is always monomeric. In contrast, the dominant ES complex with a substrate containing two tRNAs is dimeric at 0.1 M NH4Cl and monomeric at 0.8 M NH4Cl. Our results show that the B. subtilis holoenzyme can be a dimer and a monomer, and the fraction of the dimer is very sensitive to the environment. Under a variety of conditions, both the holoenzyme dimer and monomer can be present in significant amounts. Because the majority of tRNA genes are organized in large operons and because of the lack of RNase E in B. subtilis, a dimeric holoenzyme may be necessary to facilitate the processing of large precursor tRNA transcripts. Alternatively, the presence of two forms of the RNase P holoenzyme may be required for other yet unknown functions. C1 Univ Chicago, Dept Biochem & Mol Biol, Chicago, IL 60637 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Pan, T (reprint author), Univ Chicago, Dept Biochem & Mol Biol, 920 E 58th St, Chicago, IL 60637 USA. FU NIGMS NIH HHS [GM52993] NR 32 TC 20 Z9 20 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 29 PY 2002 VL 41 IS 43 BP 12986 EP 12994 DI 10.1021/bi020416k PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 607LM UT WOS:000178793100012 PM 12390025 ER PT J AU Strickland, J Porter, V Homicz, G Gossler, A AF Strickland, J Porter, V Homicz, G Gossler, A TI A vortex code for flow over rigid or flexible bluff bodies SO JOURNAL OF TURBULENCE LA English DT Article AB In this paper we discuss version 1.0 of the computer code ( CURL) that we have developed to simulate unsteady, 3D, incompressible flows around rigid and flexible bluff bodies whose geometries are made up from thin membrane or ribbon elements. The motivation for this work comes from Sandia National Laboratories need to perform complete numerical simulations of parachute deployment, inflation, and steady descent. First-generation serial and parallel versions of the uncoupled fluids code have been developed. In addition, a fluid-structure coupling scheme has been developed. Preliminary results for both a rigid and a flexible cross parachute are presented herein. C1 Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. RP Strickland, J (reprint author), Sandia Natl Labs, Engn Sci Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1468-5248 J9 J TURBUL JI J. Turbul. PD OCT 29 PY 2002 VL 3 AR 042 PG 6 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 609FE UT WOS:000178892300002 ER PT J AU Chandross, M Grest, GS Stevens, MJ AF Chandross, M Grest, GS Stevens, MJ TI Friction between alkylsilane monolayers: Molecular simulation of ordered monolayers SO LANGMUIR LA English DT Article ID ATOMIC-FORCE MICROSCOPY; SELF-ASSEMBLED MONOLAYERS; ORGANIC MONOLAYERS; LEVEL FRICTION; DYNAMICS; SURFACE; ALKANETHIOLS; INDENTATION; COMPRESSION; PRESSURE AB The adhesion and friction between two ordered self-assembled monolayers of alkylsilane chains on a silicon dioxide surface are studied using molecular dynamics simulations. These simulations focus on the alkylsilanes, which are a surface coating commonly used in microelectromechanical systems. We have investigated chain lengths of 6-18 carbon atoms for systems with 100-1600 molecules on each surface. The adhesion force between monolayers at a given tail atom separation is found to increase monotonically with decreasing chain length. For each chain length the friction simulations were performed for a range of shear velocities at separation distances corresponding to pressures of 0.2 and 2 GPa. Stick-slip motion is observed at all velocities, chain lengths, and separations for the fully packed and well-ordered systems studied here. At high pressures the average friction force is independent of chain length and velocity, while at low pressures there is a weak dependence of the friction force on shear velocity. We have investigated possible system size effects in our simulations and find that larger system sizes result only in decreased noise. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chandross, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 31 TC 71 Z9 71 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 29 PY 2002 VL 18 IS 22 BP 8392 EP 8399 DI 10.1021/la025598y PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 608HC UT WOS:000178839300022 ER PT J AU Advincula, R Zhou, QG Park, M Wang, SG Mays, J Sakellariou, G Pispas, S Hadjichristidis, N AF Advincula, R Zhou, QG Park, M Wang, SG Mays, J Sakellariou, G Pispas, S Hadjichristidis, N TI Polymer brushes by living anionic surface initiated polymerization on flat silicon (SiO(x)) and gold surfaces: Homopolymers and block copolymers SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; TRANSFER RADICAL POLYMERIZATION; HETEROGENEOUS SURFACES; GRAFT-POLYMERIZATION; PHASE-BEHAVIOR; POOR SOLVENT; POLYSTYRENE; FILMS; SUBSTRATE; STYRENE AB The formation of homopolymer and block copolymer brushes grafted from Au and (SiO(x)) surfaces via living anionic surface-initiated polymerization (LASIP) is described. The initiator precursor 1,1diphenylethylene (DPE) was functionalized with alkylsilane or alkylthiol and grafted onto planar Si wafer and Au surfaces, respectively, by self-assembled monolayer techniques. n-BuLi was used to activate the DPE initiator for anionic polymerization of monomers at the interface. A high-vacuum reactor was used for polymerization at surfaces under anhydrous solution conditions. By a careful sequence of monomer introduction, reaction, and termination, homopolymer and block copolymer tethered polymer brushes were obtained. The grafted polymer chains were investigated using surface sensitive techniques such as ellipsometry, contact angle measurements, atomic force microscopy, Fourier transform infrared spectroscopy, surface plasmon spectroscopy, and X-ray photoelectron spectroscopy. The importance of activation of the grafted initiator, control of polymerization conditions, and removal of excess BuLi is emphasized. Interesting differences in morphology, thickness, grafting density, and polymerization conditions contrast LASIP from solution and other surface-initiated polymerization mechanisms. The formation of block copolymer sequences highlights the unique utility of a living anionic polymerization technique on surfaces. C1 Univ Alabama, Dept Chem, Birmingham, AL 35294 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Athens, Dept Chem, Athens 15701, Greece. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Advincula, R (reprint author), Univ Alabama, Dept Chem, Birmingham, AL 35294 USA. RI Sakellariou, Georgios/B-1752-2014 NR 66 TC 71 Z9 72 U1 2 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 29 PY 2002 VL 18 IS 22 BP 8672 EP 8684 DI 10.1021/la025962t PG 13 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 608HC UT WOS:000178839300059 ER PT J AU Curtright, TL Zachos, CK AF Curtright, TL Zachos, CK TI Deformation quantization of superintegrable systems and Nambu mechanics SO NEW JOURNAL OF PHYSICS LA English DT Article ID DYNAMICAL SYMMETRIES; SPHERICAL GEOMETRY; SIGMA-MODELS; PHASE-SPACE AB Phase space is the framework best suited for quantizing superintegrable systems, naturally preserving the symmetry algebras of the respective Hamiltonian invariants. The power and simplicity of the method is fully illustrated through new applications to nonlinear sigma-models, specifically for de Sitter N-spheres and chiral models, where the symmetric quantum Hamiltonians amount to compact and elegant expressions. Additional power and elegance is provided by the use of Nambu brackets to incorporate the extra invariants of superintegrable models. Some new classical results are given for these brackets, and their quantization is successfully compared to that of Moyal, validating Nambu's original proposal. C1 Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Curtright, TL (reprint author), Univ Miami, Dept Phys, Box 248046, Coral Gables, FL 33124 USA. RI zachos, cosmas/C-4366-2014; Curtright, Thomas/B-6840-2015 OI zachos, cosmas/0000-0003-4379-3875; NR 42 TC 27 Z9 27 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1367-2630 J9 NEW J PHYS JI New J. Phys. PD OCT 29 PY 2002 VL 4 AR 83 DI 10.1088/1367-2630/4/1/383 PG 16 WC Physics, Multidisciplinary SC Physics GA 609FH UT WOS:000178892600002 ER PT J AU Yachandra, VK AF Yachandra, VK TI Structure of the manganese complex in photosystem II: insights from X-ray spectroscopy SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES LA English DT Article; Proceedings Paper CT Discussion Meeting of the Royal-Society CY MAR 13-14, 2002 CL ROYAL SOC, LONDON, ENGLAND HO ROYAL SOC DE extended X-ray absorption fine structure; oxygen-evolving complex; photosystem II; X-ray absorption near-edge structure; X-ray absorption spectroscopy; X-ray emission spectroscopy ID OXYGEN-EVOLVING COMPLEX; PHOTOSYNTHETIC WATER OXIDATION; ABSORPTION-SPECTROSCOPY; CENTERED OXIDATION; S-0 STATE; CLUSTER; CALCIUM; MECHANISM; EVOLUTION; PARTICLES AB We have used Mn K-edge absorption and Kbeta emission spectroscopy to determine the oxidation states of the Mn complex in the various S states. We have started exploring the new technique of resonant inelastic X-ray scattering spectroscopy; this technique can be characterized as a Raman process that uses K-edge energies (1s to 4p, ca. 6550 eV) to obtain L-edge-like spectra (2p to 3d, ca. 650 eV). The relevance of these data to the oxidation states and structure of the Mn complex is presented. We have obtained extended Xray absorption fine structure data from the S-0 and S-3 states and observed heterogeneity in the Mn-Mn distances leading us to conclude that there may be three rather than two di-mu-oxo-bridged units present per tetranuclear Mn cluster. In addition, we have obtained data using Ca and Sr X-ray spectroscopy that provide evidence for a heteronuclear Mn-Ca cluster. The possibility of three di-mu-oxo-bridged Mn-Mn moieties and the proximity of Ca is incorporated into developing structural models for the Mn cluster. The involvement of bridging and terminal O ligands of Mn in the mechanism of oxygen evolution is discussed in the context of our X-ray spectroscopy results. C1 Lawrence Berkeley Lab, Phys Biosci Div, Melvin Calvin Lab, Berkeley, CA 94720 USA. RP Yachandra, VK (reprint author), Lawrence Berkeley Lab, Phys Biosci Div, Melvin Calvin Lab, Berkeley, CA 94720 USA. RI ID, BioCAT/D-2459-2012 FU NIGMS NIH HHS [GM 55302, R01 GM055302] NR 61 TC 61 Z9 62 U1 0 U2 4 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8436 J9 PHILOS T ROY SOC B JI Philos. Trans. R. Soc. Lond. Ser. B-Biol. Sci. PD OCT 29 PY 2002 VL 357 IS 1426 BP 1347 EP 1357 DI 10.1098/rstb.2002.1133 PG 11 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 612YQ UT WOS:000179103400006 PM 12437873 ER PT J AU Mryasov, ON Gornostyrev, YN van Schilfgaarde, A Freeman, AJ AF Mryasov, ON Gornostyrev, YN van Schilfgaarde, A Freeman, AJ TI Superdislocation core structure in L1(2)Ni(3)Al, Ni3Ge and Fe3Ge: Peierls-Nabarro analysis starting from ab-initio GSF energetics calculations SO ACTA MATERIALIA LA English DT Article ID NEGATIVE TEMPERATURE-DEPENDENCE; ANOMALOUS YIELD BEHAVIOR; LL2 ORDERED ALLOYS; PLANAR DISSOCIATIONS; ELECTRON THEORY; PLASTIC-FLOW; STRENGTH; ENERGY; NI3AL; MODEL AB Superdislocation core structures in L1(2) Ni3Ge, Fe3Ge and Ni3Al were determined on the basis of ab-initio generalized stacking fault (GSF) energetics calculations. Superdislocation dissociation schemes, partials separation and core widths were calculated within the modified Peierls-Nabarro (PN) model with ab-initio GSF parameterization. Calculated superdislocation core structure parameters were found to be in agreement with available experimental data. The superdislocation core with type I (fourfold) dissociation was found to be unstable in Fe3Ge but stable and energetically preferred in Ni3Ge and Ni3Al. These results allows us to suggest a mechanism for the octahedral glide being inactive in Fe3Ge which is found to be different in several aspects with those discussed so far in the literature. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Sandia Natl Labs, Livermore, CA USA. Inst Met Phys, Ekaterinburg, Russia. RP Freeman, AJ (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RI Gornostyrev, Yuri/K-5100-2013 OI Gornostyrev, Yuri/0000-0001-7765-9805 NR 30 TC 32 Z9 34 U1 0 U2 10 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 OCT 28 PY 2002 VL 50 IS 18 BP 4545 EP 4554 AR PII S1359-6454(02)00282-3 DI 10.1016/S1359-6454(02)00282-3 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 609YW UT WOS:000178934800009 ER PT J AU Kucheyev, SO Deenapanray, PNK Jagadish, C Williams, JS Yano, M Koike, K Sasa, S Inoue, M Ogata, K AF Kucheyev, SO Deenapanray, PNK Jagadish, C Williams, JS Yano, M Koike, K Sasa, S Inoue, M Ogata, K TI Electrical isolation of ZnO by ion bombardment SO APPLIED PHYSICS LETTERS LA English DT Article ID IRRADIATION; ENERGY AB The evolution of sheet resistance of n-type single-crystal wurtzite ZnO epilayers exposed to bombardment with MeV H-1, Li-7, 160, and Si-28 ions at room temperature is studied in situ. We demonstrate that sheet resistance of ZnO can be increased by about 7 orders of magnitude as a result of ion irradiation. Due to extremely efficient dynamic annealing in ZnO, the ion doses needed for isolation of this material are about 2 orders of magnitude larger than corresponding doses in the case of another wide-bandgap semiconductor, GaN. Results also show that the ion doses necessary for electrical isolation close-to-inversely depend on the number of ion-beam-generated atomic displacements. However, in all the cases studied, defect-induced electrical isolation of ZnO is unstable to rapid thermal annealing at temperatures above similar to300degreesC. (C) 2002 American Institute of Physics. C1 Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT 0200, Australia. Osaka Inst Technol, New Mat Res Ctr, Asahi Ku, Osaka 5358585, Japan. Osaka Inst Technol, Bioventure Ctr, Asahi Ku, Osaka 5358585, Japan. RP Kucheyev, SO (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 19 TC 58 Z9 59 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 2002 VL 81 IS 18 BP 3350 EP 3352 DI 10.1063/1.1518560 PG 3 WC Physics, Applied SC Physics GA 609BB UT WOS:000178881800014 ER PT J AU Branz, HM Xu, YQ Heck, S Gao, W AF Branz, HM Xu, YQ Heck, S Gao, W TI Improved stability of hydrogenated amorphous-silicon photosensitivity by ultraviolet illumination SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLAR-CELLS; DIFFUSION; DEFECTS; MOTION; FILMS; SI AB Postdeposition ultraviolet (UV) illumination, followed by etching, improves the stability of hydrogenated amorphous-silicon thin films against subsequent light-induced degradation of photosensitivity. The etch removes a heavily damaged layer extending about 100 nm below the surface, but beneath the damage, the UV has improved the stability of 200 to 300 nm of bulk film. The open-circuit voltage of Schottky solar cells is also stabilized by UV-etch treatment. Possible mechanisms are discussed. (C) 2002 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Branz, HM (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 20 TC 6 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 2002 VL 81 IS 18 BP 3353 EP 3355 DI 10.1063/1.1518566 PG 3 WC Physics, Applied SC Physics GA 609BB UT WOS:000178881800015 ER PT J AU Yu, HG AF Yu, HG TI Accelerating the calculation of the rovibrational energies of tetraatomic molecules using a two-layer Lanczos algorithm SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; FILTER-DIAGONALIZATION METHOD; QUANTUM SCATTERING; VARIATIONAL CALCULATIONS; VECTOR PARAMETRIZATION; POLYATOMIC-MOLECULES; MECHANICS; ITERATION; CH4; ISOTOPOMERS AB The two-layer Lanczos algorithm has been extended to study the rovibrational spectrum of four-atom molecules in a mixed grid/finite basis representation basis. This algorithm exploits the partitioning structure of the Hamiltonian in polyspherical coordinates, and calculates the eigenstates in a reduced-dimension (RD) way but exactly. It consists of the standard Lanczos method for the outer layer iteration and the guided spectral transform (GST) Lanczos for the inner layer. For H2CO, numerical results show that the two-layer Lanczos method is substantially efficient. Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Yu, HG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Yu, Hua-Gen/N-7339-2015 NR 35 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 28 PY 2002 VL 365 IS 1-2 BP 189 EP 196 AR PII S0009-2614(02)01453-7 DI 10.1016/S0009-2614(02)01453-7 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 608FU UT WOS:000178835800028 ER PT J AU Mozharivskyj, Y Pecharsky, VK Franzen, HF AF Mozharivskyj, Y Pecharsky, VK Franzen, HF TI Testing thermal stability of orthorhombic GdCuP2.16 structure SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE gadolinium copper phosphide; crystal structure and symmetry; thermal expansion AB Thermal stability with respect to a structural transformation and the crystal structure of the orthorhombic gadolinium copper phosphide GdCuP2.16 was investigated using powder diffraction techniques. The structure was refined from the data collected at room temperature to yield Pmm2 space group, a = 5.3284(1), b = 5.3868(1) and c = 9.7486(2) Angstrom. The refinement results agree well with the single crystal results [J. Solid State Chem. 155 (2000) 259]. Although the phosphide preserves the orthorhombic crystal structure up to 700degreesC, the thermal expansion along the a axis becomes larger than those along b and c axes above 500 degreesC, indicating that a structural transformation is likely to occur at higher temperatures. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci, Ames, IA 50011 USA. RP Franzen, HF (reprint author), Iowa State Univ, Dept Chem, 342 Spedding Hall, Ames, IA 50011 USA. NR 9 TC 4 Z9 4 U1 1 U2 2 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 OCT 28 PY 2002 VL 345 IS 1-2 BP 100 EP 104 AR PII S0925-8388(02)00288-8 DI 10.1016/S0925-8388(02)00288-8 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 609EZ UT WOS:000178891800018 ER PT J AU Tan, KM Duquette, M Liu, JH Dong, YC Zhang, RG Joachimiak, A Lawler, J Wang, JH AF Tan, KM Duquette, M Liu, JH Dong, YC Zhang, RG Joachimiak, A Lawler, J Wang, JH TI Crystal structure of the TSP-1 type 1 repeats: a novel layered fold and its biological implication SO JOURNAL OF CELL BIOLOGY LA English DT Article DE thrombospondin; TSR domain; X-ray structure; angiogenesis; GAG binding ID HEPARIN-BINDING; GROWTH-FACTOR; RECEPTOR COMPLEX; CELL-ADHESION; F-SPONDIN; IN-VITRO; THROMBOSPONDIN-1; PROTEIN; PEPTIDES; DOMAIN AB Thrombospondin-1 (TSP-1) contains three type 1 repeats (TSRs), which mediate cell attachment, glycosaminoglycan binding, inhibition of angiogenesis, activation of TGFbeta, and inhibition of matrix metalloproteinases. The crystal structure of the TSRs reported in this article reveals a novel, antiparallel, three-stranded fold that consists of alternating stacked layers of tryptophan and arginine residues from respective strands, capped by disulfide bonds on each end. The front face of the TSR contains a right-handed spiral, positively charged groove that might be the "recognition" face, mediating interactions with various ligands. This is the first high-resolution crystal structure of a TSR domain that provides a prototypic architecture for structural and functional exploration of the diverse members of the TSR superfamily. C1 Harvard Univ, Sch Med, Dana Farber Canc Inst, Boston, MA 02115 USA. Beth Israel Deaconess Med Ctr, Boston, MA 02215 USA. Harvard Univ, Sch Med, Dept Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Pathol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Pediat, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Boston, MA 02115 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Wang, JH (reprint author), Harvard Univ, Sch Med, Dana Farber Canc Inst, 44 Binney St,Room SM-1036, Boston, MA 02115 USA. FU NCI NIH HHS [P01 CA092644, CA 92644]; NHLBI NIH HHS [HL 49081, HL 68003, R01 HL049081, R01 HL068003]; NIGMS NIH HHS [GM 56008] NR 49 TC 135 Z9 139 U1 0 U2 2 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9525 J9 J CELL BIOL JI J. Cell Biol. PD OCT 28 PY 2002 VL 159 IS 2 BP 373 EP 382 DI 10.1083/jcb.200206062 PG 10 WC Cell Biology SC Cell Biology GA 612AQ UT WOS:000179051500017 PM 12391027 ER PT J AU Bailey, DH Frolov, AM AF Bailey, DH Frolov, AM TI Universal variational expansion for high-precision bound-state calculations in three-body systems. Applications to weakly bound, adiabatic and two-shell cluster systems SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID HELIUM-MUONIC ATOMS; HYPERFINE-STRUCTURE; 3-BODY SYSTEMS; EXCITED-STATES; FUSION; IONS; H2+ AB The results of high-precision variational calculations are reported for a number of bound states in various Coulomb three-body systems, including helium and helium-muonic atoms, some adiabatic systems (H-2(+), D-2(+) and DT+ ions) and muonic molecular ions ppmu, ddmu, ttmu and dtmu. The hyperfine splittings for the double electron-excited states in the helium-muonic (3)He(2+)mu(-)e(-) and (4)He(2+)mu(-)e(-) atoms have also been determined. The results of this study are significantly more accurate than results known from earlier calculations for all considered systems and states. The approach can be used to determine the bound-state spectra in various three-body systems to arbitrary high accuracy. We also discuss a number of complications which are usually detected in high-precision bound-state calculations of few-body systems. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Queens Univ, Dept Chem, Kingston, ON K7L 3N6, Canada. RP Bailey, DH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Mail Stop 50B-2239, Berkeley, CA 94720 USA. NR 49 TC 57 Z9 57 U1 8 U2 12 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 OCT 28 PY 2002 VL 35 IS 20 BP 4287 EP 4298 AR PII S0953-4075(02)39861-4 DI 10.1088/0953-4075/35/20/314 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 620UV UT WOS:000179551600017 ER PT J AU Berg, DJ Boncella, JM Andersen, RA AF Berg, DJ Boncella, JM Andersen, RA TI Preparation of coordination compounds of Cp*Yb-2 with heterocyclic nitrogen bases: Examples of antiferromagnetic exchange coupling across bridging ligands SO ORGANOMETALLICS LA English DT Article ID CRYSTAL-STRUCTURE; REDUCTION; ACETONITRILE; REACTIVITY; COMPLEXES; AZOBENZENE; SERIES; ANION AB Several adducts are isolated between heterocyclic nitrogen bases and Cp*Yb-2. The adducts fall into several general classes. The membership within the class is related to the reduction potential of the given heterocyclic base relative to that of Cp*Yb-2. Analytically pure 1:1 adducts of the type Cp*Yb-2(L) are formed with pyrazine, quinoxaline, 1,5- and 1,8-naphthyridine, and 4,4'-bipyridine as toluene-insoluble solids. The 1:1 adducts with phthalazine and azobenzene and the 1:2 adduct with pyridazine are soluble in toluene, from which they may be isolated by crystallization. All of the adducts in this class are paramagnetic, and their effective magnetic moments are consistent with the formulation Cp*Yb-2(III)(L.-) (L.- = radical anion), in which spins on the individual units are uncoupled to 5 K. Adducts between Cp*Yb-2 and phenazine, 2,2'-azopyridine, 2,2'-bipyrimidine, 2,2'-azobenzene, and 2,3-bis(2-pyridino)quinoxaline are of 2:1 stoichiometry: (Cp*Yb-2)(2)(mu-L). The crystal structure of (Cp*Yb-2)(2)(mu-bipyrimidine) shows that the two metallocenes are bridged by a planar bipyrimidine ligand, and the other 2:1 adducts are assumed to have a similar structure. The effective magnetic moment of these 2:1 adducts shows that each Cp*Yb-2(III) fragment behaves as an isolated paramagnetic, and the bridging ligand is a diamagnetic dianion at high temperature. At low temperature the last three adducts undergo antiferromagnetic coupling with a Neel temperature of about 20 K. A spin polarization model is advanced to account for the electronic exchange coupling. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Andersen, RA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. NR 40 TC 77 Z9 77 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD OCT 28 PY 2002 VL 21 IS 22 BP 4622 EP 4631 DI 10.1021/om020477e PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 607EF UT WOS:000178778100010 ER PT J AU Klei, SR Tilley, TD Bergman, RG AF Klei, SR Tilley, TD Bergman, RG TI Stoichiometric and catalytic behavior of cationic silyl and silylene complexes SO ORGANOMETALLICS LA English DT Article ID H BOND ACTIVATION; REDUCTIVE ELIMINATION; MECHANISM; INSERTION; IRIDIUM; HYDROSILATION; CHEMISTRY; HYDROGEN; DIHYDRIDE; EXCHANGE AB Reactions of Ir(III) silyl and silylene complexes with a variety of unsaturated substrates were investigated. The reactivity of these complexes toward small molecules was also examined, and this led to the discovery of a nitrile carbon-carbon bond cleavage under mild conditions. Both silyl and silylene complexes of Ir(III) are precatalysts for catalytic hydrosilylation of ketones, and the mechanism of this reaction is discussed. In the course of studying the catalytic reaction mechanism, analogous new ruthenium silylene complexes of the form [Cp*(PMe3)(2)Ru(SiR2)][B(C6F5)(4)] (Cp* = eta(5)-C5Me5, R = Pr-i, SPh) were prepared. A comparison of [Cp*(PMe3)Ir(SiPh2)(H)][B(C6F5)(4)] and the known Lewis acid hydrosilylation catalyst B(C6F5)(3) is also made. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 56 TC 75 Z9 75 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD OCT 28 PY 2002 VL 21 IS 22 BP 4648 EP 4661 DI 10.1021/om0203173 PG 14 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 607EF UT WOS:000178778100013 ER PT J AU Gordon, JC Giesbrecht, GR Clark, DL Hay, PJ Keogh, DW Poli, R Scott, BL Watkin, JG AF Gordon, JC Giesbrecht, GR Clark, DL Hay, PJ Keogh, DW Poli, R Scott, BL Watkin, JG TI The first example of a mu(2)-imido functionality bound to a lanthanide metal center: X-ray crystal structure and DFT study of [(mu-ArN)Sm(mu-NHAr)(mu-Me)AlMe2](2) (Ar = 2,6-(Pr2C6H3)-Pr-i) SO ORGANOMETALLICS LA English DT Article ID CARBON BOND FORMATION; C-H ACTIVATION; IMIDO COMPLEXES; ORGANOIMIDO COMPLEXES; LIGAND; REACTIVITY; METATHESIS; COORDINATION; CHEMISTRY; YTTRIUM AB Reaction of 3 equiv of 2,6-diisopropylaniline with Sm[N(SiMe3)(2)](3) affords the dimeric species [Sm(NHAr)(3)](2) (1). X-ray crystallography illustrates that each metal center in 1 engages in an eta(6)-arene interaction with the aryl ring of an amide ligand attached to an adjacent samarium. IR spectroscopy indicates that the pi-arene interactions are maintained in solution. Reaction of 1 with 4 equiv of trimethylaluminum leads to formation of the bis(mu(2)-imido) complex [(mu-ArN)Sm(mu-NHAr)(mu-Me)AlMe2](2) (2). The molecular structure of 2 contains a unique central Sm2N2 core which displays extremely short bridging Sm-N distances of 2.152(8) and 2.271(7) Angstrom, characteristic of an imido complex. Density functional theory (DFT) calculations have been carried out in order to gain a better understanding of the nature of the bonding interactions within complex 2 and indicate that the 5d metal acceptor orbitals play a significant role in stabilizing pi-donation from the imido groups to the samarium centers within the Sm2N2 core. C1 Los Alamos Natl Lab, Div Chem, C SIC, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Nucl Mat Technol, NMT DO, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, NMT DO, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Glenn T Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. Univ Bourgogne 1, Fac Sci Gabriel, LSEO, UMR 5632, F-21000 Dijon, France. RP Gordon, JC (reprint author), Los Alamos Natl Lab, Div Chem, C SIC, Mail Stop J514, Los Alamos, NM 87545 USA. RI Clark, David/A-9729-2011; Poli, Rinaldo/C-7483-2017; Scott, Brian/D-8995-2017 OI Poli, Rinaldo/0000-0002-5220-2515; Scott, Brian/0000-0003-0468-5396 NR 62 TC 65 Z9 66 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD OCT 28 PY 2002 VL 21 IS 22 BP 4726 EP 4734 DI 10.1021/om0206960 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 607EF UT WOS:000178778100021 ER PT J AU Price, AJ Ciancanelli, R Noll, BC Curtis, CJ DuBois, DL DuBois, MR AF Price, AJ Ciancanelli, R Noll, BC Curtis, CJ DuBois, DL DuBois, MR TI HRh(dppb)(2), a powerful hydride donor SO ORGANOMETALLICS LA English DT Article ID TRANSITION-METAL COMPLEXES; THERMODYNAMIC ACIDITY; CARBON-MONOXIDE; CO2 REDUCTION; HYDROGEN; CHEMISTRY; DIPHOSPHINE; POTENTIALS; RHODIUM(I); ABILITIES AB The Rh(I) and Rh(III) hydrides HRh(dppb)(2) and [HRh(dppb)(2)(NCCH3)](BF4)(2) (where dppb is 1,2-(bis(diphenylphosphino)benzene) have been prepared, and a structural study of [HRh(dppb)2(NCCH3)](BF4)2 has been completed. The latter complex is an octahedral complex with a trans arrangement of the hydride and acetonitrile ligands. A pK(a) value of 9.4 was measured for this complex by equilibration of [Rh(dppb)(2)](BF4) with 4-bromoanilinium tetrafluoroborate in acetonitrile. [Rh(dppb)21(BF4) reacts with H-2 in the presence of Pt(dmpp)(2), which acts as a base, to form HRh(dppb)(2) and [HPt(dmpp)(2)](BF4) (where dmpp = 1,2-bis-(dimethylphosphino)propane). An equilibrium constant of 0.42 +/- 0.2 was measured for this reaction. Using this equilibrium measurement and a thermodynamic cycle, the hydride donor ability (DeltaGdegrees(H-)) of HRh(dppb)2 was determined to be 34 kcal/mol. This value indicates that HRh(diphosphine)(2) complexes are powerful hydride donors. Similarly the pKa value of HRh(dppb)2 was calculated to be 35 from a thermodynamic cycle that included the potential of the Rh(I/-I) couple (E-1/2 = -2.02 V vs ferrocene). These results combined with results from the literature suggest the following order of hydricity for five-coordinate, 18-electron hydrides: second row > third row > first row. Similarly an acidity order of second row first row > third row is deduced. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP DuBois, DL (reprint author), Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. NR 43 TC 54 Z9 54 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD OCT 28 PY 2002 VL 21 IS 22 BP 4833 EP 4839 DI 10.1021/om020421k PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 607EF UT WOS:000178778100035 ER PT J AU Crooker, SA Hollingsworth, JA Tretiak, S Klimov, VI AF Crooker, SA Hollingsworth, JA Tretiak, S Klimov, VI TI Spectrally resolved dynamics of energy transfer in quantum-dot assemblies: Towards engineered energy flows in artificial materials SO PHYSICAL REVIEW LETTERS LA English DT Article AB We report on the dynamics of resonant energy transfer in monodisperse, mixed-size, and energy-gradient (layered) assemblies of CdSe nanocrystal quantum dots. Time-resolved and spectrally resolved photoluminescence directly reveals the energy-dependent transfer rate of excitons from smaller to larger dots via electrostatic coupling. The data show a rapid (0.7-1.9 ns) energy transfer directly across a large tens-of-meV energy gap (i.e., between dots of disparate size), and suggest that interdot energy transfer can approach picosecond time scales in structurally optimized systems. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Crooker, SA (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Tretiak, Sergei/B-5556-2009 OI Tretiak, Sergei/0000-0001-5547-3647 NR 14 TC 464 Z9 466 U1 13 U2 87 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 OCT 28 PY 2002 VL 89 IS 18 AR 186802 DI 10.1103/PhysRevLett.89.186802 PG 4 WC Physics, Multidisciplinary SC Physics GA 604LH UT WOS:000178622000043 PM 12398626 ER PT J AU Iavarone, M Karapetrov, G Koshelev, AE Kwok, WK Crabtree, GW Hinks, DG Kang, WN Choi, EM Kim, HJ Kim, HJ Lee, SI AF Iavarone, M Karapetrov, G Koshelev, AE Kwok, WK Crabtree, GW Hinks, DG Kang, WN Choi, EM Kim, HJ Kim, HJ Lee, SI TI Two-band superconductivity in MgB2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID TUNNELING SPECTROSCOPY; GAPS; TEMPERATURE AB The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta(1)=2.3 meV and Delta(2)=7.1 meV at 4.2 K. Different spectral weights of the partial superconducting density of states are a reflection of different tunneling directions in this multiband system. Temperature evolution of the tunneling spectra follows the BCS scenario [Phys. Rev. Lett. 3, 552 (1959)] with both gaps vanishing at the bulk T-c. The data confirm the importance of Fermi-surface sheet dependent superconductivity in MgB2 proposed in the multigap modelLiu et al. [Phys. Rev. Lett. 87, 087005 (2001)]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Iavarone, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Iavarone, Maria/C-3628-2008; Koshelev, Alexei/K-3971-2013; Karapetrov, Goran/C-2840-2008 OI Koshelev, Alexei/0000-0002-1167-5906; Karapetrov, Goran/0000-0003-1113-0137 NR 20 TC 241 Z9 243 U1 2 U2 52 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 OCT 28 PY 2002 VL 89 IS 18 AR 187002 DI 10.1103/PhysRevLett.89.187002 PG 4 WC Physics, Multidisciplinary SC Physics GA 604LH UT WOS:000178622000045 PM 12398628 ER PT J AU James, DFV Kwiat, PG AF James, DFV Kwiat, PG TI Atomic-vapor-based high efficiency optical detectors with photon number resolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID BELLS-INEQUALITY; LIGHT; ENTANGLEMENT; VIOLATION; STORAGE AB The ability to detect very weak optical fields with high efficiency (>99%) and to distinguish the number of photons in a given time interval is a very challenging technical problem with enormous potential payoffs in quantum communications and information processing. We propose to employ an atomic vapor as the active medium, prepared in a specific quantum state using laser radiation. The absorption of a photon will be aided by a dressing laser, and the presence or absence of an excited atom will be detected using the "cycling transition" approach perfected for ion traps. By incorporating an appropriate up-conversion scheme, our method can be applied to a wide variety of optical wavelengths. C1 Los Alamos Natl Lab, Theoret Div T4, Los Alamos, NM 87545 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP James, DFV (reprint author), Los Alamos Natl Lab, Theoret Div T4, MS B-283,POB 1663, Los Alamos, NM 87545 USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 21 TC 72 Z9 72 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 OCT 28 PY 2002 VL 89 IS 18 AR 183601 DI 10.1103/PhysRevLett.89.183601 PG 4 WC Physics, Multidisciplinary SC Physics GA 604LH UT WOS:000178622000017 PM 12398600 ER PT J AU Skoulidas, AI Ackerman, DM Johnson, JK Sholl, DS AF Skoulidas, AI Ackerman, DM Johnson, JK Sholl, DS TI Rapid transport of gases in carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID PATH-INTEGRAL SIMULATIONS; MOLECULAR-DIFFUSION; MEMBRANES; ADSORPTION; EQUILIBRIUM; SILICALITE; SEPARATION; MIXTURES; GRAPHITE; DYNAMICS AB We report atomistic simulations for both self- and transport diffusivities of light gases in carbon nanotubes and in two zeolites with comparable pore sizes. We find that transport rates in nanotubes are orders of magnitude faster than in the zeolites we have studied or in any microporous material for which experimental data are available. The exceptionally high transport rates in nanotubes are shown to be a result of the inherent smoothness of the nanotubes. We predict that carbon nanotube membranes will have fluxes that are orders of magnitude greater than crystalline zeolite membranes. C1 Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Sholl, DS (reprint author), Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. RI Johnson, Karl/E-9733-2013 OI Johnson, Karl/0000-0002-3608-8003 NR 28 TC 393 Z9 396 U1 12 U2 93 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 OCT 28 PY 2002 VL 89 IS 18 AR 185901 DI 10.1103/PhysRevLett.89.185901 PG 4 WC Physics, Multidisciplinary SC Physics GA 604LH UT WOS:000178622000035 PM 12398618 ER PT J AU Wiringa, RB Pieper, SC AF Wiringa, RB Pieper, SC TI Evolution of nuclear spectra with nuclear forces SO PHYSICAL REVIEW LETTERS LA English DT Article ID MONTE-CARLO CALCULATIONS; MODELS; STATE AB We first define a series of NN interaction models ranging from very simple to fully realistic. We then present Green's function Monte Carlo calculations of light nuclei to show how nuclear spectra evolve as the nuclear forces are made increasingly sophisticated. We find that the absence of stable five- and eight-body nuclei depends crucially on the spin, isospin, and tensor components of the nuclear force. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. EM wiringa@anl.gov; spieper@anl.gov RI Wiringa, Robert/M-4970-2015 NR 20 TC 193 Z9 196 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 2002 VL 89 IS 18 AR 182501 DI 10.1103/PhysRevLett.89.182501 PG 4 WC Physics, Multidisciplinary SC Physics GA 604LH UT WOS:000178622000008 PM 12398591 ER PT J AU Kevrekidis, PG Malomed, BA AF Kevrekidis, PG Malomed, BA TI Solitons in coupled Toda lattices SO PHYSICS LETTERS A LA English DT Article ID NONLINEAR SCHRODINGER-EQUATION; TRANSMISSION-LINES; FIBER COUPLERS; WAVE-GUIDES; SYSTEMS; TRAINS AB We introduce a natural model of two Toda lattices (TLs) with an attractive linear coupling between them. By means of systematic simulations, we study interactions between solitons in the two chains. Two new long-lived states are found, which have no counterparts in the usual single-component TL equation: a steadily moving double-humped pulse (with unequal humps, but identical field distributions in the two components), and a large nearly-static immobile pulse, with small internal vibrations. Collisions between solitons are also studied. Such collisions generate conspicuous emission of radiation, but do not result in merger of solitons into a bound state. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Massachusetts, Dept Math & Stat, Amherst, MA 01003 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Tel Aviv Univ, Fac Engn, Dept Interdisciplinary Studies, IL-69978 Tel Aviv, Israel. RP Kevrekidis, PG (reprint author), Univ Massachusetts, Dept Math & Stat, Amherst, MA 01003 USA. NR 18 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 28 PY 2002 VL 303 IS 5-6 BP 328 EP 336 AR PII S0375-9601(02)01309-9 DI 10.1016/S0375-9601(02)01309-9 PG 9 WC Physics, Multidisciplinary SC Physics GA 611YJ UT WOS:000179045400005 ER PT J AU Boles, JO Henderson, J Hatch, D Silks, LA AF Boles, JO Henderson, J Hatch, D Silks, LA TI Synthesis and incorporation of [6,7]-selenatryptophan into dihydrofolate reductase SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article DE beta-seleno[3,2-b]pyrrolyl-L-alanine; [4,5]selenatryptophan; beta-selenolo[2,3-b]pyrrolyl-L-alanine; [6,7]selenatryptophan; selenolo[2,3-b]pyrrole; selenomethionine; telluromethionine; [4,5]SeTrp; [6,7]SeTrp ID ESCHERICHIA-COLI; AMINO-ACIDS; CRYSTAL-STRUCTURE; PROTEINS; BINDING; RESIDUES AB Until recently, the only selenium containing amino acid which could be used to completely substitute for a-wild type amino acid was selenomethionine (SeMet). In the last decade the preparation of SeMet containing proteins has proved to be valuable tools in the determination of three-dimensional structure by multiwavelength anomalous diffraction (MAD) techniques. The potential utility of a selenium containing tryptophan analog, beta-seleno[3,2-b]pyrrolyl-L-alanine ([4,5]selenatryptophan), has recently been demonstrated in the literature. This finding shows promise for the bioincorporation of its positional isomer, beta-selenolo[2,3-b]pyrrolyl-L-alanine ([6,7]selenatryptophan), thereby adding to the essential arsenal of selenium-containing amino acids for use in the characterization of proteins. The synthesis of [6,7]selenatryptophan by enzymatic biotransformation with tryptophan synthase from selenolo [2,3-b]pyrrole was carried out as well as its characterization by NMR spectroscopy and thin layer chromatography. Selenatryptophyl dihydrofolate reductase ([6,7]SeTrp-DHFR) was then synthesized in vivo, purified, and found to exhibit no perturbations to enzymatic activity. (C) 2002 Elsevier Science (USA). All rights reserved. C1 Tennessee Technol Univ, Dept Chem, Cookeville, TN 38505 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Boles, JO (reprint author), Tennessee Technol Univ, Dept Chem, Cookeville, TN 38505 USA. NR 21 TC 13 Z9 13 U1 1 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD OCT 25 PY 2002 VL 298 IS 2 BP 257 EP 261 AR PII S0006-291X(02)02438-5 DI 10.1016/S0006-291X(02)02438-5 PG 5 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 610AM UT WOS:000178938600013 PM 12387825 ER PT J AU Poirier, MA Li, HL Macosko, J Cai, SW Amzel, M Ross, CA AF Poirier, MA Li, HL Macosko, J Cai, SW Amzel, M Ross, CA TI Huntingtin spheroids and protofibrils as precursors in polyglutamine fibrilization SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NEURONAL INTRANUCLEAR INCLUSIONS; IN-VITRO; PALLIDOLUYSIAN ATROPHY; ALZHEIMERS-DISEASE; ALPHA-SYNUCLEIN; REPEAT LENGTH; NEURODEGENERATION; AGGREGATION; INHIBITION; OLIGOMERS AB The pathology of Huntington's disease is characterized by neuronal degeneration and inclusions containing N-terminal fragments of mutant huntingtin (htt). To study htt aggregation, we examined purified htt fragments in vitro, finding globular and protofibrillar intermediates participating in the genesis of mature fibrils. These intermediates were high in beta-structure. Furthermore, Congo Red, a dye that stains amyloid fibrils, prevented the assembly of mutant htt into mature fibrils, but not the formation of protofibrils. Other proteins capable of forming ordered aggregates, such as amyloid beta and alpha-synuclein, form similar intermediates, suggesting that the mechanisms of mutant htt aggregation and possibly htt toxicity may overlap with other neurodegenerative disorders. C1 Johns Hopkins Univ, Sch Med, Dept Psychiat, Div Neurobiol, Baltimore, MD 21205 USA. Johns Hopkins Univ, Sch Med, Dept Biochem & Biophys, Baltimore, MD 21205 USA. Lawrence Berkeley Natl Lab, Donner Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Massachusetts, Dept Chem, N Dartmouth, MA 02747 USA. RP Ross, CA (reprint author), Johns Hopkins Univ, Sch Med, Dept Psychiat, Div Neurobiol, 615 Ross Res Bldg,720 Rutland Ave, Baltimore, MD 21205 USA. RI Ross, Christopher/H-8395-2013; OI Amzel, L. Mario/0000-0002-0129-9572 FU NIGMS NIH HHS [GM 40633] NR 35 TC 237 Z9 244 U1 0 U2 8 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 25 PY 2002 VL 277 IS 43 BP 41032 EP 41037 DI 10.1074/jbc.M205809200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 607KU UT WOS:000178791400112 PM 12171927 ER PT J AU Paskach, TJ Schrader, GL McCarley, RE AF Paskach, TJ Schrader, GL McCarley, RE TI Synthesis of methanethiol from methanol over reduced molybdenum sulfide catalysts based on the Mo6S8 cluster SO JOURNAL OF CATALYSIS LA English DT Article DE methanethiol synthesis; organosulfur catalysis; molybdenum sulfide cluster catalysts ID CHEVREL PHASES; HYDRODESULFURIZATION; PRECURSORS; COMPLEXES; RAMAN; EXAFS; MOS2 AB Catalysts having structures containing the Mo6S8 cluster (crystalline Chevrel phases, amorphous ternary molybdenum sulfides, and ligated molecular clusters) have been discovered to be active for thiol synthesis from methanol and hydrogen sulfide at 250 degreesC and 1 atm. An amorphous lanthanum molybdenum sulfide material was found to be the most selective catalyst (>80% methanethiol) at low conversions. CO2, CO, CS2, and CH4 were the major by-products in these studies. (C) 2002 Elsevier Science (USA). C1 Iowa State Univ, US DOE, Dept Chem Engn, Ames, IA 50011 USA. Iowa State Univ, US DOE, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Schrader, GL (reprint author), Iowa State Univ, US DOE, Dept Chem Engn, Ames, IA 50011 USA. NR 26 TC 19 Z9 19 U1 3 U2 23 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD OCT 25 PY 2002 VL 211 IS 2 BP 285 EP 295 DI 10.1006/jcat.2002.3684 PG 11 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 607LQ UT WOS:000178793400001 ER PT J AU D'Helon, C Protopopeseu, V AF D'Helon, C Protopopeseu, V TI New summing algorithm using ensemble computing SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID SPIN LIOUVILLE SPACE; QUANTUM COMPUTATION; RESONANCE AB We propose an ensemble algorithm, which provides a new approach for evaluating and summing up a set of function samples. The proposed algorithm is not a quantum algorithm, insofar as it does not involve quantum entanglement. The query complexity of the algorithm depends only on the scaling of the measurement sensitivity with the number of distinct spin subensembles. From a practical point of view, the proposed algorithm may result in an exponential speedup, compared to known quantum and classical summing algorithms. However, in general, this advantage exists only if the total number of function samples is below a threshold value which depends on the measurement sensitivity. C1 Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. RP D'Helon, C (reprint author), Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. NR 22 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD OCT 25 PY 2002 VL 35 IS 42 BP L597 EP L604 AR PII S0305-4470(02)38689-X DI 10.1088/0305-4470/35/42/102 PG 8 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 617DX UT WOS:000179346800002 ER PT J AU Kaschner, GC Gibeling, JC AF Kaschner, GC Gibeling, JC TI A study of the mechanisms of cyclic deformation in f.c.c. metals using strain rate change tests SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE low cycle fatigue; strain rate change; dislocation glide; thermal activation; Cottrell-Stokes law ID AISI-304L STAINLESS-STEEL; FATIGUE; ALLOYS; PLASTICITY; KINETICS; BEHAVIOR; COPPER AB Plastic strain rate change tests were performed during low cycle fatigue (LCF) of 7075-T6 aluminum and Type 304 stainless steel using plastic strain as the control variable. The evolution of dislocation interactions was observed by evaluating the activation area and true stress as a function of cumulative plastic strain. Activation areas for 7075-T6 aluminum at each of three plastic strain amplitudes, 0.2, 0.4, and 0.6%, have initial values of approximately 250-450 b(2) which decrease to 70-115 b(2), respectively, during cyclic loading to saturation. Activation areas for 304 stainless steel at both amplitudes tested, 0.4 and 0.6%, exhibit initial values of 90 b(2) which increase slightly to 130 b(2) at large cumulative strains. Both materials show a deviation from the Cottrell-Stokes law during cyclic hardening and softening. Tests performed at saturation reveal a mild dependence of activation area on plastic strain amplitude for aluminum but no such relationship for stainless steel. These results reflect a contrast between wavy slip for pure copper and 7075 aluminum versus planar slip for 304 stainless steel tested at room temperature. In addition, the Cottrell-Stokes law holds in both alloys at saturation. Dislocation motion in 7075 aluminum and 304 stainless steel is controlled by obstacles that are characteristically more thermal than forest dislocations; obstacles in 7075-T6 aluminum are identified as solutes from re-desolved particles; for 304 stainless steel, the obstacles are also in the form of solutes. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Div Engn & Mat Sci, Davis, CA 95616 USA. Los Alamos Natl Lab, MST8, Los Alamos, NM 87545 USA. RP Gibeling, JC (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, Div Engn & Mat Sci, 1 Shields Ave, Davis, CA 95616 USA. RI Kaschner, George/H-4445-2013 NR 31 TC 5 Z9 7 U1 2 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 25 PY 2002 VL 336 IS 1-2 BP 170 EP 176 AR PII S0921-5093(01)01972-4 DI 10.1016/S0921-5093(01)01972-4 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 606MN UT WOS:000178737900022 ER PT J AU Schilling, CH Tomasik, P Li, CP Sikora, M AF Schilling, CH Tomasik, P Li, CP Sikora, M TI Protein plasticizers for aqueous suspensions of micrometric- and nanometric-alumina powder SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE albumin; albumin hydrolysate; ceramics; gelcasting; nanomaterials; rheology ID METHYLCELLULOSE POLYMERS; CERAMIC POWDERS; SLURRIES AB Ovoalbumin and its hydrolysate were developed as economical and environmental friendly plasticizers for the production of engineering ceramics from micrometric- and nanometric-sized powders. These proteins are feasible as replacements for commonly used petrochemicals that suffer from problems of toxicity, volatility, flammability, and high cost. A key advantage to protein-based additives is that they are available from inexpensive plant and animal sources (e.g. waste products such as slaughterhouse blood, by-products from meat and plant production). Aqueous alumina suspensions and high-density aqueous alumina pastes were blended with such proteins to form green bodies that were easily moldable and could be sintered to full density without cracking. The application of proteins provides thermally induced gelation of aqueous alumina suspensions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Univ Agr, PL-31120 Krakow, Poland. RP Schilling, CH (reprint author), Saginaw Valley State Univ, Univ Ctr, MI 48710 USA. NR 27 TC 5 Z9 5 U1 0 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 25 PY 2002 VL 336 IS 1-2 BP 219 EP 224 AR PII S0921-5093(01)01959-1 DI 10.1016/S0921-5093(01)01959-1 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 606MN UT WOS:000178737900029 ER PT J AU Mattsson, AE AF Mattsson, AE TI In pursuit of the "divine" functional SO SCIENCE LA English DT Editorial Material ID EXCHANGE-ENERGY; ELECTRON-GAS; DENSITY; APPROXIMATIONS; STATE C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM aematts@sandia.gov NR 14 TC 92 Z9 92 U1 2 U2 12 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD OCT 25 PY 2002 VL 298 IS 5594 BP 759 EP 760 DI 10.1126/science.1077710 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 607KR UT WOS:000178791200037 PM 12399569 ER PT J AU Bishop, JKB Davis, RE Sherman, JT AF Bishop, JKB Davis, RE Sherman, JT TI Robotic observations of dust storm enhancement of carbon biomass in the North Pacific SO SCIENCE LA English DT Article ID SUB-ARCTIC PACIFIC; IRON FERTILIZATION; SOUTH-PACIFIC; SARGASSO SEA; UPPER OCEAN; PHYTOPLANKTON; VARIABILITY; SENSORS AB Two autonomous robotic pro ling oats deployed in the subarctic North Pacific on 10 April 2001 provided direct records of carbon biomass variability from surface to 1000 meters below surface at daily and diurnal time scales. Eight months of real-time data documented the marine biological response to natural events, including hydrographic changes, multiple storms, and the April 2001 dust event. High-frequency observations of upper ocean particulate organic carbon variability show a near doubling of biomass in the mixed layer over a 2-week period after the passage of a cloud of Gobi desert dust. The temporal evolution of particulate organic carbon enhancement and an increase in chlorophyll use efficiency after the dust storm suggest a biotic response to a natural iron fertilization by the dust. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP Bishop, JKB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. OI Davis, Russ/0000-0003-1903-6313 NR 35 TC 216 Z9 254 U1 4 U2 35 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 OCT 25 PY 2002 VL 298 IS 5594 BP 817 EP 821 DI 10.1126/science.1074961 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 607KR UT WOS:000178791200056 PM 12399588 ER PT J AU Chen, YJ Fenn, PT Lau, KC Ng, CY Law, CK Li, WK AF Chen, YJ Fenn, PT Lau, KC Ng, CY Law, CK Li, WK TI Study of the dissociation of CH3SCH3+ by collisional activation: Evidence of nonstatistical behavior SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PULSED-FIELD IONIZATION; TOTAL CROSS-SECTIONS; MASS-SPECTROMETRY; CHARGE-TRANSFER; PHOTOIONIZATION; CH3SH; CH3CH2SH+; PHOTODISSOCIATION; DYNAMICS; CH2S AB The collision-induced dissociation (CID) reaction of CH3SCH3+ + Ar was studied in a triple-quadrupole, double-octopole ion-molecule reaction apparatus. The absolute total cross sections for the product ions CH2SH+/CH3S+, CH2S+, CHS+, and CH3+ formed in the CID reaction have been measured in the center-of-mass kinetic energy (E-cm) range of 1-19 eV. Using the charge-transfer probing technique, we found that mass-47 product ions are formed in both the CH2SH+ and CH3S+ structures: The onsets for CH2SH+, CH3S+, CH2S+, CHS+, and CH3+ are consistent with their thermochemical thresholds. The formation of the higher-energy product channel CH3S+ + CH3, which involves C-S bond scission, is found to dominate in the E-cm range immediately above its onset. The lower-energy channel corresponding to the formation CH3SCH2+ + H is not found. The strong preference observed for the higher-energy channel is in accordance with the conclusions obtained from the CID studies of CH3SH+ and CH3CH2SH+, providing further evidence that the CID of CH3SCH3+ is also nonstatistical. The high yield of CH3S+ + CH3 is attributed to the more efficient translational-to-vibrational energy transfer for the C-S stretching modes with lower frequencies than to those for the C-H stretching modes with higher frequencies, along with weak coupling between these vibrational modes with significantly different frequencies of CH3SCH3+. In addition, the dissociation pathways deduced are consistent with the results of ab initio calculations at the G3 level. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. Chinese Univ Hong Kong, Dept Chem, Shatin, Hong Kong, Peoples R China. RP Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. EM cyng@chem.ucdavis.edu; wkLi@cuhk.edu.hk RI Chen, Yu-Ju/E-9481-2015; OI LAU, Kai Chung /0000-0003-2125-6841 NR 29 TC 11 Z9 11 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 24 PY 2002 VL 106 IS 42 BP 9729 EP 9736 DI 10.1021/jp014496y PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 607LA UT WOS:000178792000012 ER PT J AU Zhan, CG Dixon, DA AF Zhan, CG Dixon, DA TI First-principles determination of the absolute hydration free energy of the hydroxide ion SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; REACTION FIELD TREATMENT; CARBOXYLIC-ACID ESTERS; FIRST SOLVATION SHELL; GAUSSIAN-BASIS SETS; CHARGE PENETRATION; AB-INITIO; WATER-MOLECULES; WAVE-FUNCTIONS; ALKALINE-HYDROLYSIS AB The absolute hydration free energy of the hydroxide ion, DeltaG(hyd)(298)(HO-), a fundamental quantity in solution chemistry, has "experimental" values ranging from -90.6 to -110.0 kcal/mol. We report a first-principles determination of DeltaG(hyd)(298)(HO-) by using a reliable computational protocol of high-level first-principles supermolecule-continuum calculations, the same approach recently used to determine the absolute hydration free energy of the proton. In the supermolecule-continuum approach, part of the solvent surrounding the solute is treated quantum mechanically, and the remaining bulk solvent is approximated by a dielectric continuum medium accounted for by a recently developed self-consistent reaction field model known as surface and volume polarization for electrostatic interaction (SVPE) or the. fully polarizable continuum model (FPCM). With this approach, the calculated results can systematically be improved by increasing the number of quantum mechanically treated solvent molecules, and DeltaG(hyd)(298)(HO-) is accurately predicted to be -104.5 kcal/mol. The DeltaG(hyd)(298)(HO-) value of -104.5 kcal/mol, combined with our previously determined DeltaG(hyd)(298)(H+) value of -262.4 kcal/mol, allows the prediction of the sum of absolute hydration free energies of the proton and hydroxide to be -366.9 kcal/mol, in excellent agreement with the well-established experimental thermodynamic value of -366.6 +/- 0.1 kcal/mol. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dixon, DA (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, MS K1-83,POB 999, Richland, WA 99352 USA. NR 82 TC 88 Z9 89 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 24 PY 2002 VL 106 IS 42 BP 9737 EP 9744 DI 10.1021/jp014533l PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 607LA UT WOS:000178792000013 ER PT J AU Laskin, J Bailey, TH Denisov, EV Futrell, JH AF Laskin, J Bailey, TH Denisov, EV Futrell, JH TI On the relative stability of singly protonated des-Arg(1)- and des-Arg(9)-bradykinins SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID INFRARED RADIATIVE DISSOCIATION; MASS-SPECTROMETRY; GAS-PHASE; IONS; COLLISIONS; PEPTIDES; SURFACES; ENERGIES AB Normal-incidence surface-induced dissociation of singly protonated des-Arg(1)-bradykinin (PPGFSPFR) and des-Arg(9)-bradykinin (RPPGFSPF) has been studied using a specially designed Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). We found that, with a reaction time of 1 s, the collision-energy-resolved fragmentation efficiency curve (FEC) for des-Arg(9)-bradykinin is shifted to lower energies by about 4 eV relative to the FEC for des-Arg(1)-bradykinin. Because the Arrhenius activation energies found by Williams and co-workers in BIRD experiments are 0.82 and 1.2 eV for des-Arg(1)- and des-Arg(9)-bradykinin, respectively, we expected to find the reverse order in our long-reaction-time FTICR-SID experiments. We rationalize the difference between our data and the thermal kinetics using Tolman's theorem to calculate threshold energies from the Arrhenius activation parameters. We found that, when the preexponential factor for reaction is very high (>10(17) s(-1)) or very low (<10(10) s(-1)), Tolman's correction becomes fairly large. In this case, the Arrhenius parameters are strongly correlated, and the activation energy depends on the reaction dynamics and temperature. This can result in the reversal of the order of the Arrhenius activation energies for different systems relative to the order of the threshold energies, meaning that conclusions about relative stabilities of large molecules should be based not on the thermal activation energies but rather on actual threshold energies, which can be calculated using Tolman's correction. The threshold energies extracted from the Arrhenius activation parameters are 1.15 and 1.24 eV for des-Arg(1)- and des-Arg(9)-bradykinin, respectively, assuming a temperature of 450 K. However, des-Arg(1)-bradykinin dissociates via a very tight transition state. Consequently, microcanonical rate-energy dependencies for these two peptides cross at very low internal energies and des-Arg(9)-bradykinin has a larger rate constant at internal energies sampled experimentally. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. RP Laskin, J (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, POB 999,K8-96, Richland, WA 99352 USA. RI Laskin, Julia/H-9974-2012 OI Laskin, Julia/0000-0002-4533-9644 NR 20 TC 22 Z9 22 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 OCT 24 PY 2002 VL 106 IS 42 BP 9832 EP 9836 DI 10.1021/jp025604z PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 607LA UT WOS:000178792000024 ER PT J AU Kang, SH Kim, J Stoll, ME Abraham, D Sun, YK Amine, K AF Kang, SH Kim, J Stoll, ME Abraham, D Sun, YK Amine, K TI Layered Li(Ni0.5-xMn0.5-xM '(2x))O-2 (M ' = Co, Al, Ti; x = 0, 0.025) cathode materials for Li-ion rechargeable batteries SO JOURNAL OF POWER SOURCES LA English DT Article DE lithium-ion rechargeable battery; cathode materials; lithium manganese nickel oxides; layered structure ID LITHIUM BATTERIES; O2 STRUCTURE; LIMNO2; R(3)OVER-BAR-M; DIFFRACTION; ELECTRODE; CHEMISTRY; SPINEL; OXIDE; CELLS AB Layered Li(Ni0.5-xMn0.5-xM'(2x))O-2 materials (M' = Co, Al, Ti; x = 0, 0.025) were synthesized using a manganese-nickel hydroxide precursor, and the effect of dopants on the electrochemical properties was investigated. Li(Ni0.5Mn0.5)02 exhibited a discharge capacity of 120 mAh/g in the voltage range of 2.8-4.3 V with a slight capacity fade up to 40 cycles (0.09% per cycle); by doping of 5 mol% Co, Al, and Ti, the discharge capacities increased to 140, 142, and 132 mAh/g, respectively, and almost no capacity fading was observed. The cathode material containing 5 mol% Co had the lowest impedance, 47 Q cm 2, while undoped, Ti-doped, and Al-doped materials had impedance of 64, 62, and 99 Omega cm(2), respectively. Unlike the other dopants, cobalt was found to improve the electronic conductivity of the material. Further improvement in the impedance of these materials is needed to meet the requirement for powering hybrid electric vehicle (HEV, <35 Omega cm(2)). In all materials, structural transformation from a layered to a spinel structure was not observed during electrochemical cycling. Cyclic voltammetry and X-ray photoelectron spectroscopy (XPS) data suggested that Ni and Mn exist as Ni2+ and Mn4+ in the layered structure. Differential scanning calorimetry (DSC) data showed that exothermic peaks of fully charged Li1-y(Ni0.5-xMn0.5-xM'(2x))O-2 appeared at higher temperature (270-290 degreesC) than LiNiO2-based cathode materials, which indicates that the thermal stability of Li(Ni0.5-xMn0.5-xM'(2x))O-2 is better than those of LiNiO2-based cathode materials. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem Technol, Electrochem Technol Program, Argonne, IL 60439 USA. Hanyang Univ, Div Chem Technol, Seoul 133791, South Korea. RP Amine, K (reprint author), Argonne Natl Lab, Div Chem Technol, Electrochem Technol Program, 9700 S Cass Ave,Bldg 203-C110, Argonne, IL 60439 USA. RI Kang, Sun-Ho/E-7570-2010; Sun, Yang-Kook/B-9157-2013; Amine, Khalil/K-9344-2013 OI Sun, Yang-Kook/0000-0002-0117-0170; NR 25 TC 177 Z9 211 U1 12 U2 180 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 OCT 24 PY 2002 VL 112 IS 1 BP 41 EP 48 AR PII S0378-7753(02)00360-9 DI 10.1016/S0378-7753(02)00360-9 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 611LJ UT WOS:000179018400006 ER PT J AU Chou, YS Stevenson, JW Chick, LA AF Chou, YS Stevenson, JW Chick, LA TI Ultra-low leak rate of hybrid compressive mica seals for solid oxide fuel cells SO JOURNAL OF POWER SOURCES LA English DT Article DE solid oxide fuel cells; scanning electron microscopy; coefficient of thermal expansion ID GLASS-CERAMICS; SOFC; PROGRESS AB A novel hybrid compressive mica seal was developed that showed a reduction of leak rate by about 4300 times (compared to simple mica seals) at 800 degreesC. The hybrid compressive mica seal is composed of 2 compliant glass layers and a mica layer. Three commercially available micas were tested in hybrid compressive seals for solid oxide fuel cell applications. The best results were obtained using Muscovite single crystal mica. The normalized leak rate for this seal at 800 degreesC was only 1.55 x 10(-4) sccm/cm at a stress of 100 psi and a pressure gradient of 2 psi. Seals based on the other commercial micas (Muscovite and Phlogopite mica papers), also exhibited superior leak rates (similar to0.011 sccm/cm) compared to simple mica seals without the compliant glass layer (about 6-9 sccm/cm). The microstructure of the mica was examined before and after the 800 degreesC leak tests using scanning electron microscopy. The cause for the substantial reduction of the leak rate was discussed. In addition, the effect of the compressive stresses was also investigated. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Mat Resource Dept, Richland, WA 99352 USA. RP Chou, YS (reprint author), Pacific NW Natl Lab, Mat Resource Dept, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 10 TC 74 Z9 81 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD OCT 24 PY 2002 VL 112 IS 1 BP 130 EP 136 AR PII S0378-7753(02)00356-7 DI 10.1016/S0378-7753(02)00356-7 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 611LJ UT WOS:000179018400019 ER PT J AU Shim, J Kostecki, R Richardson, T Song, X Striebel, KA AF Shim, J Kostecki, R Richardson, T Song, X Striebel, KA TI Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature SO JOURNAL OF POWER SOURCES LA English DT Article DE Li-ion battery; cycle-life; LiNi0.8Co0.15Al0.05O2 ID SURFACE-CHEMISTRY; LI; ELECTRODES; STABILITY; INSERTION; IMPEDANCE; POWER; CELLS AB Laboratory-size LiNi0.8Co0.15Al0.05O2/graphite lithium-ion pouch cells were cycled over 100% DOD at room temperature and 60 degreesC in order to investigate high-temperature degradation mechanisms of this important technology. Capacity fade for the cell was correlated with that for the individual components, using electrochemical analysis of the electrodes and other diagnostic techniques. The high-temperature cell lost 65% of its initial capacity after 140 cycles at 60 degreesC compared to only a 4% loss for the cell cycled at room temperature. Cell ohmic impedance increased significantly with a elevated temperature cycling, resulting in some of loss of capacity at the C/2 rate. However, as determined with slow rate testing of the individual electrodes, the anode retained most of its original capacity, while the cathode lost 65%, even when cycled with a fresh source of lithium. Diagnostic evaluation of cell components including X-ray diffraction (XRD), Raman, CSAFM and suggest capacity loss occurs primarily due to a rise in the impedance of the cathode, especially at the end-of-charge. The impedance rise may be caused in part by a loss of the conductive carbon at the surface of the cathode and/or by an organic film on the surface of the cathode that becomes non-ionically conductive at low lithium content. Published by Elsevier Science B.V. C1 Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Striebel, KA (reprint author), Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 21 TC 203 Z9 213 U1 14 U2 163 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 OCT 24 PY 2002 VL 112 IS 1 BP 222 EP 230 AR PII S0378-7753(02)00363-4 DI 10.1016/S0378-7753(02)00363-4 PG 9 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 611LJ UT WOS:000179018400029 ER PT J AU Braun, A Wang, HX Bergmann, U Tucker, MC Gu, WW Cramer, SP Cairns, EJ AF Braun, A Wang, HX Bergmann, U Tucker, MC Gu, WW Cramer, SP Cairns, EJ TI Origin of chemical shift of manganese in lithium battery electrode materials - a comparison of hard and soft X-ray techniques SO JOURNAL OF POWER SOURCES LA English DT Article DE soft X-ray; hard X-ray; battery electrodes; surface; manganese; reduction ID ABSORPTION; CELLS AB L-edge X-ray absorption near edge spectroscopy and K-beta emission spectroscopy were applied to monitor ex situ chemical valence changes of manganese in battery electrode materials as they appear during electrode processing and battery operation. We found that significant chemical shifts of the spectra occur already during electrode fabrication, prior to any electrochemical treatment. Employment of these two different techniques allows for the qualitative separation of contributions originating from the surface and from the bulk of the electrode particles. Published by Elsevier Science B.V. C1 Ernst Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Braun, A (reprint author), Ernst Orlando Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI BRAUN, Artur/A-1154-2009; Cairns, Elton/E-8873-2012 OI BRAUN, Artur/0000-0002-6992-7774; Cairns, Elton/0000-0002-1179-7591 NR 7 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD OCT 24 PY 2002 VL 112 IS 1 BP 231 EP 235 AR PII S0378-7753(02)00367-1 DI 10.1016/S0378-7753(02)00367-1 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 611LJ UT WOS:000179018400030 ER PT J AU Doeff, MM Richardson, TJ Hollingsworth, J Yuan, CW Gonzales, M AF Doeff, MM Richardson, TJ Hollingsworth, J Yuan, CW Gonzales, M TI Synthesis and characterization of a copper-substituted manganese oxide with the Na0.44MnO2 structure SO JOURNAL OF POWER SOURCES LA English DT Article DE rechargeable lithium battery; manganese oxides ID ELECTRODE MATERIALS; LITHIUM; BATTERIES AB NaxCu0.11Mn0.89O2 (X = 0.4-0.5) with the Na0.44MnO2 structure was prepared by sol-gel, glycine-nitrate combustion synthesis and solid-state routes. Li0.45-xCu0.11Mn0.89O2 was prepared by ion exchange from the glycine-nitrate sodium-containing precursor. Rietveld refinement of X-ray diffraction power patterns indicates that Cu substitutes in the MO-position. The electrochemical characteristics of LixCu0.11Mn0.89O2 are changed by Cu-substitution, resulting in a somewhat lower capacity between fixed voltage limits compared to the unsubstituted material. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Div Sci Mat, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Doeff, MM (reprint author), Univ Calif Berkeley, Div Sci Mat, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. OI Doeff, Marca/0000-0002-2148-8047 NR 9 TC 29 Z9 31 U1 6 U2 34 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 OCT 24 PY 2002 VL 112 IS 1 BP 294 EP 297 AR PII S0378-7753(02)00449-4 DI 10.1016/S0378-7753(02)00449-4 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 611LJ UT WOS:000179018400037 ER PT J AU Wang, M AF Wang, M TI Fuel choices for fuel-cell vehicles: well-to-wheels energy and emission impacts SO JOURNAL OF POWER SOURCES LA English DT Article DE well-to-wheels analysis; fuel-cell vehicles; fuels; energy use; greenhouse gas emissions; hydrogen AB Because of their high energy efficiencies and low emissions, fuel-cell vehicles (FCVs) are undergoing extensive research and development. While hydrogen will likely be the ultimate fuel to power fuel-cell vehicles, because of current infrastructure constraints, hydrogen-carrying fuels are being investigated as transitional fuel-cell fuels. A complete well-to-wheels (WTW) evaluation of fuel-cell vehicle energy and emission effects that examines (1) energy feedstock recovery and transportation; (2) fuel production, transportation, and distribution; and (3) vehicle operation must be conducted to assist decision makers in selecting the fuel-cell fuels that achieve the greatest energy and emission benefits. A fuel-cycle model developed at Argonne National Laboratory-called the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model-was used to evaluate well-to-wheels energy and emission impacts of various fuel-cell fuels. The results show that different fuel-cell fuels can have significantly different energy and greenhouse gas emission effects. Therefore, if fuel-cell vehicles are to achieve the envisioned energy and emission reduction benefits, pathways for producing the fuels that power them must be carefully examined. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Ctr Transportat Res, Argonne, IL 60439 USA. RP Wang, M (reprint author), Argonne Natl Lab, Ctr Transportat Res, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 TC 82 Z9 84 U1 2 U2 16 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 OCT 24 PY 2002 VL 112 IS 1 BP 307 EP 321 AR PII S0378-7753(02)00447-0 DI 10.1016/S0378-7753(02)00447-0 PG 15 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 611LJ UT WOS:000179018400039 ER PT J AU DiMauro, LF AF DiMauro, LF TI Attophysics: Atomic photography SO NATURE LA English DT Editorial Material ID ATTOSECOND C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP DiMauro, LF (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 3 TC 3 Z9 3 U1 0 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 24 PY 2002 VL 419 IS 6909 BP 789 EP 790 DI 10.1038/419789a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 607BD UT WOS:000178769800024 PM 12397335 ER PT J AU Noren, AJ Bierman, PR Steig, EJ Lini, A Southon, J AF Noren, AJ Bierman, PR Steig, EJ Lini, A Southon, J TI Millennial-scale storminess variability in the northeastern United States during the Holocene epoch SO NATURE LA English DT Article ID NORTH-ATLANTIC; YR RECORD; CLIMATE; ICE; CIRCULATION; SEDIMENTS; EROSION; EVENTS; NORWAY; CORES C1 Univ Vermont, Dept Geol, Burlington, VT 05405 USA. Univ Washington, Quaternary Res Ctr, Seattle, WA 98195 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Noren, AJ (reprint author), Univ Vermont, Dept Geol, Burlington, VT 05405 USA. RI Steig, Eric/G-9088-2015; OI Steig, Eric/0000-0002-8191-5549; Lini, Andrea/0000-0002-2920-570X NR 30 TC 104 Z9 113 U1 4 U2 28 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 24 PY 2002 VL 419 IS 6909 BP 821 EP 824 DI 10.1038/nature01132 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 607BD UT WOS:000178769800041 PM 12397353 ER PT J AU Macesanu, C McMullen, CD Nandi, S AF Macesanu, C McMullen, CD Nandi, S TI New signal for universal extra dimensions SO PHYSICS LETTERS B LA English DT Article ID COLLIDER; COMPACTIFICATION; GRAVITY; MODELS; TEV; TOP AB In the universal extra dimensions (UED) scenario, the tree level masses of the first level Kaluza-Klein (KK) excitations of Standard Model particles are essentially degenerate. Radiative corrections will, however, lift this degeneracy, allowing the first level excitations to decay to the lightest KK particle (LKP), which is the gamma*. KK number conservation implies that the LKP is stable. Then, since the SM particles radiated during these decays are rather soft, the observation of KK excitations production and decay in collider experiments will be quite difficult. We propose to add to this model KK number violating interactions mediated by gravity, which allow the gamma* to decay to a photon and a KK graviton. For a variety a models and a large range of parameters, these decays will occur within the detector. Thus, pair production of KK excitations will give rise to a striking collider signal, consisting of two hard photons plus large missing energy (due to escaping gravitons). We evaluate the cross-section for these signals at the Tevatron and LHC, and derive the reach of these colliders in the search for universal extra dimensions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. EM mcos@pas.rochester.edu; mcmulle@okstate.edu; shaown@okstate.edu NR 28 TC 73 Z9 74 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 OCT 24 PY 2002 VL 546 IS 3-4 BP 253 EP 260 AR PII S0370-2693(02)02694-1 DI 10.1016/S0370-2693(02)02694-1 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 608LT UT WOS:000178848400009 ER PT J AU Maslov, S Sneppen, K AF Maslov, S Sneppen, K TI Protein interaction networks beyond artifacts SO FEBS LETTERS LA English DT Letter C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Norwegian Univ Sci & Technol, Dept Phys, N-7491 Trondheim, Norway. RP Maslov, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 5 TC 17 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD OCT 23 PY 2002 VL 530 IS 1-3 BP 255 EP 256 AR PII S0014-5793(02)03428-2 DI 10.1016/S0014-5793(02)03428-2 PG 2 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 608PZ UT WOS:000178856900048 PM 12387903 ER PT J AU Murthy, N Thng, YX Schuck, S Xu, MC Frechet, JMJ AF Murthy, N Thng, YX Schuck, S Xu, MC Frechet, JMJ TI A novel strategy for encapsulation and release of proteins: Hydrogels and microgels with acid-labile acetal cross-linkers SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article C1 Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Frechet, JMJ (reprint author), Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. OI Frechet, Jean /0000-0001-6419-0163 NR 13 TC 270 Z9 278 U1 8 U2 78 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 OCT 23 PY 2002 VL 124 IS 42 BP 12398 EP 12399 DI 10.1021/ja026925r PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 605HU UT WOS:000178672900003 PM 12381166 ER PT J AU Konze, WV Scott, BL Kubas, GJ AF Konze, WV Scott, BL Kubas, GJ TI C-H activation and C-C coupling of arenes by cationic Pt(II) complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY STRUCTURE; CARBON BOND FORMATION; DIIMINE AQUA COMPLEX; TRANSITION-METALS; HETEROBINUCLEAR COMPLEXES; HYDROCARBON ACTIVATION; HYDROXYLIC SOLVENT; NICKEL-COMPLEXES; BIARYL SYNTHESIS; MILD CONDITIONS AB The synthesis and characterization of cationic platinum complexes of the type [(R2PC2H4PR2)-PtMe(OEt2)]BArF (R = Cy, Et) are reported. These electrophilic platinum cations are found to react quantitatively with arenes (benzene, toluene) at room temperature by undergoing intermolecular C-H activation with concomitant C-C coupling to generate complexes of the type [{Pt(R2PC2H4PR2)}(2)(mu-eta(3): eta(3)-biaryl)][BArF](2). The dianionic biaryl ligands in these compounds exhibit a rare mu-eta(3):eta(3)-bis-allyl bonding mode and can be removed from the complex with stoichiometric oxidants to generate the free biaryl and [(R2PC2H4PR2)Pt(mu-X)](2)[BArF](2) (R = Cy, Et; X = Cl, I). The cationic platinum complexes [(R2PC2H4PR2)-PtMe(OEt2)](3)BArF (R = Cy, Et) are also quite reactive with water, forming the bridging hydroxide complexes [(R2PC2H4PR2)Pt(mu-OH)](2)[BArF](2) (R = Cy, Et). A possible mechanism is proposed for the C-C coupling reaction based upon the structures of these bridging biphenyl complexes, which provides a new perspective for the related palladium-catalyzed oxidative coupling of arenes to form biaryls. C1 Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Kubas, GJ (reprint author), Los Alamos Natl Lab, Chem Sci & Technol Div, MS J514, Los Alamos, NM 87545 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 69 TC 56 Z9 56 U1 0 U2 9 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 OCT 23 PY 2002 VL 124 IS 42 BP 12550 EP 12556 DI 10.1021/ja020798h PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 605HU UT WOS:000178672900036 PM 12381199 ER PT J AU Brown, CM Manson, JL AF Brown, CM Manson, JL TI Solid-state ligand dynamics in interpenetrating Mn[N(CN)(2)](2)(pyrazine): A neutron spectroscopy study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DICYANAMIDE N(CN)(2)(-); STRUCTURAL ISOMERISM; MAGNETIC-PROPERTIES; 3-D NETWORK; SCATTERING; CO; PYRAZINE; DENSITY; MOTION; PYZ AB We have used quasielastic neutron scattering to probe the solid-state ligand dynamics in the coordination polymer Mn[N(CN)(2)](2)(pyz) {pyz = pyrazine} which has double-interpenetrating 3D lattices. A reversible structural phase transition occurs at 410 K as shown by neutron spectroscopy and differential scanning calorimetry. The origin of this transition is linked to rotational dynamics associated with the bridging pyz ligands. At 425 K, the pyrazine ring motion can be solely regarded as a 180degrees reorientational jump about the axis defined by the Mn-N coordinative bonds, occurring with a correlation time of similar to70 ps. This model can be extended to the 200-410 K temperature region using high-resolution backscattering spectroscopy to measure an identical motion on the time scale of nanoseconds with an activation energy of 24 +/- 2 kJ mol(-1). In contrast, no quasielastic scattering is seen for the 2D layered variant beta-Cu[N(CN)(2)](2)-(pyz), owing to its more compact layer packing motif. Importantly, this work represents the very first study of solid-state rotational dynamics in an interpenetrating lattice structure. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, BIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Manson, JL (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave,Bldg 200,Room A193, Argonne, IL 60439 USA. EM jlmanson@anl.gov RI Brown, Craig/B-5430-2009 OI Brown, Craig/0000-0002-9637-9355 NR 33 TC 16 Z9 17 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 23 PY 2002 VL 124 IS 42 BP 12600 EP 12605 DI 10.1021/ja017124b PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 605HU UT WOS:000178672900042 PM 12381205 ER PT J AU Balasubramanian, K AF Balasubramanian, K TI Breakdown of the singlet and triplet nature of electronic states of the superheavy element 114 dihydride (114H(2)) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; LASER PHOTOELECTRON SPECTROMETRY; MOLECULES; HYDRIDES; HEAVY; CONFIGURATION; RELATIVITY; SEPARATION; METHYLENE; CHEMISTRY AB It is demonstrated that the superheavy element (114) forms a dihydride with electronic features that exhibit breakdown of the conventional singlet (X(1)A(1)) and triplet (B-3(1)) states due to large relativistic effects including spin-orbit effects. The (1)A(1) state is shown to undergo avoided crossing with the B-3(1)(A(1)) state and other states in the C-2v(2) double group. We have carried out relativistic complete active-space multiconfiguration interaction followed by multireference configuration interaction computations including spin-orbit effects that included several million configurations including 6d electron correlations for the electronic states of the superheavy element (114)H-2. The potential energy curves of both ground and excited states are computed including electron correlation and spin-orbit effects simultaneously. The curves exhibit unusual features from their traditional nonrelativistic counterparts: namely, (1)A(1), B-3(1), and B-1(1) states due to spin-orbit coupling. The spin-orbit effects are shown to destabilize (114)H-2 by almost 2.6 eV. (C) 2002 American Institute of Physics. C1 Univ Calif Davis, Dept Appl Sci, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Glenn T Seaborg Ctr, Berkeley, CA 94720 USA. RP Univ Calif Davis, Dept Appl Sci, Livermore, CA 94550 USA. EM kbala@ucdavis.edu NR 45 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 2002 VL 117 IS 16 BP 7426 EP 7432 DI 10.1063/1.1508371 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602AW UT WOS:000178483400004 ER PT J AU Bergeman, T Julienne, PS Williams, CJ Tiesinga, E Manaa, MR Wang, H Gould, PL Stwalley, WC AF Bergeman, T Julienne, PS Williams, CJ Tiesinga, E Manaa, MR Wang, H Gould, PL Stwalley, WC TI Predissociations in 0(u)(+) and 1(g) states of K-2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; ALKALI-METAL DIMERS; SCATTERING LENGTHS; PHOTOASSOCIATIVE SPECTROSCOPY; ELECTRONIC-STATE; POTENTIAL CURVES; BOUND-STATES; LINE-SHAPES; ATOMS; COLLISIONS AB Recently Wang, Gould, and Stwalley [Phys. Rev. Lett. 80, 476 (1998)] showed by exciting atomic fragments that predissociation occurs in the 1(g) and 0(u)(+) states of K-2. In this study, we supplement the interpretation given in the original report with a more detailed discussion. The calculations presented here use discrete variable representation, close coupling, and semiclassical methods, and incorporate an ab initio calculation of diagonal and off-diagonal spin-orbit elements. The predicted predissociation widths for the 1(g) state are too narrow to be observed directly, but may be correlated with the strength of the spectral lines observed by exciting atomic fragments. The missing v=90 level of the 1(g) state in the observed fragmentation spectrum, where the predissociation rate is calculated to be nearly maximum, is attributed to a node in the absorption line strength close to this vibrational level. Since the available information on K-2 electronic states (despite recent progress) gives inadequate information on the inner walls of the A state and especially of the b state, calculations of predissociation in the 0(u)(+) state can give only a range of possible widths. We fit widths to 0(u)(+) spectral lines observed by monitoring trap loss. The fitted experimental widths are significantly larger than the maximum calculated predissociation widths, suggesting that there was line broadening associated with the laser power required for the observation. (C) 2002 American Institute of Physics. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94551 USA. Aerosp Corp, Elect & Photon Lab, Los Angeles, CA 90009 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Bergeman, T (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RI Williams, Carl/B-5877-2009; Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 58 TC 14 Z9 14 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 2002 VL 117 IS 16 BP 7491 EP 7505 DI 10.1063/1.1508375 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602AW UT WOS:000178483400010 ER PT J AU Zhao, XC Kwon, S Vidic, RD Borguet, E Johnson, JK AF Zhao, XC Kwon, S Vidic, RD Borguet, E Johnson, JK TI Layering and orientational ordering of propane on graphite: An experimental and simulation study SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CANONICAL MONTE-CARLO; MOLECULAR-DYNAMICS SIMULATION; LENNARD-JONES MIXTURES; SLIT PORES; N-ALKANES; MULTILAYER ADSORPTION; COMPUTER-SIMULATIONS; MICROPOROUS CARBONS; PHYSICAL ADSORPTION; ZEOLITE CAVITIES AB We report the results of an experimental and theoretical study of propane adsorption on highly oriented pyrolytic graphite. Simulations and experiments were carried out for temperatures from 90 to 110 K and pressures from ultrahigh vacuum up to about 0.5 mTorr. Both simulations and experiments show that propane adsorbs in a layer-by-layer fashion and exhibits continuous growth beyond the second layer at the higher temperatures studied. Experimental adsorption data were obtained by optical differential reflectance (ODR) and temperature programmed desorption (TPD). The ODR method is able to dynamically follow the adsorption and desorption process as a function of time over a wide pressures range, while TPD probes only the desorption events at ultrahigh vacuum conditions. The influence of the fluid-fluid potential on the adsorption isotherms has been investigated by comparing simulations using five different propane potentials. The pressure at which the second layer forms was found to vary by more than 1 order of magnitude among the potentials tested, whereas the isosteric heat of adsorption is less sensitive to the potential. We find that the propane potential that best describes the liquid phase energetics is in the best agreement with experimental adsorption isotherms and isosteric heats. The binding energy of propane in the monolayer measured from TPD experiments is in excellent agreement with that computed from simulations, both giving values of about 30 kJ mol(-1). The isosteric heat of adsorption at incipient second layer formation is 23+/-2 kJ mol(-1) as measured from ODR isotherms and 24+/-1 kJ mol(-1) computed from simulations. The isosteric heat as a function of coverage computed from molecular simulations is roughly constant over the 1-2 and the 2-3 layering transitions at 91 K. We show that this unusual behavior is due to a rotational transition, whereby molecules in the first layer rotate from a parallel (all CHx groups in contact with the graphite plane) to a perpendicular (one CH3 group pointing up) orientation. This rotational transition has two effects: it allows more molecules to adsorb in the monolayer and increases the isosteric heat of adsorption in the second layer over that for adsorption onto an atomically smooth surface. (C) 2002 American Institute of Physics. C1 Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15261 USA. Univ Pittsburgh, Ctr Surface Sci, Pittsburgh, PA 15261 USA. Univ Pittsburgh, Dept Civil & Environm Engn, Pittsburgh, PA 15261 USA. Univ Pittsburgh, Ctr Surface Sci, Pittsburgh, PA 15260 USA. Univ Pittsburgh, Dept Civil & Environm Engn, Pittsburgh, PA 15260 USA. RP Johnson, JK (reprint author), Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. RI Johnson, Karl/E-9733-2013; OI Johnson, Karl/0000-0002-3608-8003; Vidic, Radisav/0000-0001-7969-6845 NR 89 TC 23 Z9 23 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 2002 VL 117 IS 16 BP 7719 EP 7731 DI 10.1063/1.1508363 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602AW UT WOS:000178483400035 ER PT J AU Wilson, KR Schaller, RD Co, DT Saykally, RJ Rude, BS Catalano, T Bozek, JD AF Wilson, KR Schaller, RD Co, DT Saykally, RJ Rude, BS Catalano, T Bozek, JD TI Surface relaxation in liquid water and methanol studied by x-ray absorption spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VAPOR INTERFACE; MOLECULAR-DYNAMICS; FINE-STRUCTURE; VIBRATIONAL SPECTROSCOPY; AMBIENT CONDITIONS; DIFFRACTION; CLUSTERS; SCATTERING; TENSION; EXAFS AB X-ray absorption spectroscopy is a powerful probe of local electronic structure in disordered media. By employing extended x-ray absorption fine structure spectroscopy of liquid microjets, the intermolecular O-O distance has been observed to undergo a 5.9% expansion at the liquid water interface, in contrast to liquid methanol for which there is a 4.6% surface contraction. Despite the similar properties of liquid water and methanol (e.g., abnormal heats of vaporization, boiling points, dipole moments, etc.), this result implies dramatic differences in the surface hydrogen bond structure, which is evidenced by the difference in surface tension of these liquids. This result is consistent with surface vibrational spectroscopy, which indicates both stronger hydrogen bonding and polar ordering at the methanol surface as a consequence of "hydrophobic packing" of the methyl group. (C) 2002 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Saykally, RJ (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010; OI Bozek, John/0000-0001-7486-7238; Co, Dick/0000-0003-0698-3004 NR 38 TC 98 Z9 98 U1 2 U2 18 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 2002 VL 117 IS 16 BP 7738 EP 7744 DI 10.1063/1.1508364 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602AW UT WOS:000178483400037 ER PT J AU Wiyatno, W Pople, JA Gast, AP Waymouth, RM Fuller, GG AF Wiyatno, W Pople, JA Gast, AP Waymouth, RM Fuller, GG TI Dynamic response of stereoblock elastomeric polypropylene studied by rheooptics and X-ray scattering. 1. Influence of isotacticity SO MACROMOLECULES LA English DT Article ID GROUP-IVB CATALYSTS; METALLOCENE CATALYSTS; PROPYLENE POLYMERIZATION; ZIRCONOCENE CATALYSTS; PROPENE POLYMERIZATION; POLY(PROPYLENE); PROPAGATION; COMPLEXES; POLYMERS; STRATEGY AB The dynamic response of elastomeric polypropylene (ePP) prepared by metallocene 2-arylindene hafnium catalyst was investigated by rheooptical birefringence as well as wide- and small-angle X-ray scattering (WAXS and SAXS). Solvent extraction of ePP ([mmmm] = 34%) results in three fractions with increasing tacticity, crystallinity, and molecular weight in the following order: ether soluble ([mmmm] = 21%), heptane soluble (44%), and heptane insoluble (76%). Unstretched ePP reveals a crystalline phase of the a-form isotactic polypropylene (i-PP). Tensile stretching of ePP yields three sets of scatterings (equatorial, off-axis diagonal, and meridional are). High-tacticity fractions contribute to the equatorial and off-axis diagonal scatterings, revealing molecular-scale orientation parallel to the strain axis and crystalline phase transformation from the a-form to the mesomorphic form. The meridional arc is contributed by the low-tacticity ether-soluble fraction with crystalline chains oriented with a preferred direction orthogonal relative to the strain direction. SAXS, which probes long-range ordering, exhibits a broad and diffuse meridional peak for the intermediate-tacticity fraction. This implies that lamellae are oriented orthogonal to the strain direction upon stretching. Permanent deformation of ePP after stretching, as measured by the residual strain (tensile set), originates from permanently oriented crystallites and chains pinned within crystalline networks. C1 Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. MIT, Dept Chem Engn, Cambridge, MA 02139 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Waymouth, RM (reprint author), Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. OI Waymouth, Robert/0000-0001-9862-9509 NR 56 TC 17 Z9 17 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 22 PY 2002 VL 35 IS 22 BP 8488 EP 8497 DI 10.1021/ma020261o PG 10 WC Polymer Science SC Polymer Science GA 606MP UT WOS:000178738000033 ER PT J AU Wiyatno, W Pople, JA Gast, AP Waymouth, RM Fuller, GG AF Wiyatno, W Pople, JA Gast, AP Waymouth, RM Fuller, GG TI Dynamic response of stereoblock elastomeric polypropylene studied by rheooptics and X-ray scattering. 2. Orthogonally oriented crystalline chains SO MACROMOLECULES LA English DT Article ID SHEAR-ENHANCED CRYSTALLIZATION; ISOTACTIC POLYPROPYLENE; SMALL-ANGLE; ZIRCONOCENE CATALYSTS; POLYMERIZATION; POLYMERS; FLOW; POLY(PROPYLENE); MORPHOLOGY; SKIN AB A combination of tensile stress, rheooptical birefringence, and wide-angle X-ray scattering (WAXS) Was used to probe the dynamic response of the low-tacticity ether-soluble (ES) fraction of elastomeric polypropylene (ePP) derived from metallocene 2-arylindene hafnium. catalyst. The ES fraction has isotactic pentad distribution [mmmm] = 21% and a very low amount of crystallinity (less than or equal to2% by differential scanning calorimetry and WAXS). In tensile stretching and step-strain shearing, ES exhibits unusual deformation behavior of crystalline chains preferentially oriented orthogonal relative to the deformation axis. Under deformation, WAXS; shows arcing along the meridian axis at a scattering angle 2theta = 16.0degrees (d = 0.551 +/- 0.002 nm) which coincides with one of the characteristic reflections of the beta-form, but the higher order reflection for the beta-form at 2theta = 21.3degrees is not observed. The meridional arcing, which signifies crystallization of the low-tacticity fraction of ePP, is also observed when ES is blended with higher-tacticity fractions of ePP. The meridional arcing, however, is observed at 2theta = 14.0degrees, corresponding to (110) reflection of the alpha-form, instead of at 2theta = 16.0degrees for the neat ES. The crystallization in the alpha-form offers evidence of cocrystallization of the ES fraction with the higher-tacticity components in the same crystalline form as the host matrix. We believe that the cocrystallization occurs through an epitaxial growth in the ac-faces of the alpha-form. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. MIT, Dept Chem Engn, Cambridge, MA 02139 USA. RP Waymouth, RM (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. OI Waymouth, Robert/0000-0001-9862-9509 NR 58 TC 14 Z9 14 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 22 PY 2002 VL 35 IS 22 BP 8498 EP 8508 DI 10.1021/ma020262g PG 11 WC Polymer Science SC Polymer Science GA 606MP UT WOS:000178738000034 ER PT J AU Scrymgeour, DA Sharan, A Gopalan, V Gahagan, KT Casson, JL Sander, R Robinson, JM Muhammad, F Chandramani, P Kiamilev, F AF Scrymgeour, DA Sharan, A Gopalan, V Gahagan, KT Casson, JL Sander, R Robinson, JM Muhammad, F Chandramani, P Kiamilev, F TI Cascaded electro-optic scanning of laser light over large angles using domain microengineered ferroelectrics SO APPLIED PHYSICS LETTERS LA English DT Article ID DEPENDENT PROPAGATION; SINGLE-CRYSTAL; BEAM SCANNERS AB We present a device concept based on cascaded electro-optic deflection in a domain microengineered ferroelectric chip. In our design, large deflection angles are achieved by cascading several smaller scanners in a single ferroelectric chip, such that each successive scanner stage builds upon the deflection of the previous stage. We demonstrate the basic concept using a two-stage device fabricated in a single crystal wafer of ferroelectric LiTaO3. By operating the device using a specially designed programmable multichannel driver that provides +/-1.1 kV per stage, a total scan angle of 25.4degrees at 5 kHz was demonstrated. Even larger angles of deflection are possible with additional scanner stages. (C) 2002 American Institute of Physics. C1 Penn State Univ, Mat Res Inst, University Pk, PA 16802 USA. Corning Inc, Corning, NY 14831 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Delaware, Dept Elect & Comp Engn, Newark, DE 19716 USA. RP Scrymgeour, DA (reprint author), Penn State Univ, Mat Res Inst, University Pk, PA 16802 USA. RI Scrymgeour, David/C-1981-2008 NR 17 TC 41 Z9 47 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3140 EP 3142 DI 10.1063/1.1516232 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900008 ER PT J AU Jiang, H McNary, J Tom, HWK Yan, M Radousky, HB Demos, SG AF Jiang, H McNary, J Tom, HWK Yan, M Radousky, HB Demos, SG TI Nanosecond time-resolved multiprobe imaging of laser damage in transparent solids SO APPLIED PHYSICS LETTERS LA English DT Article ID DYNAMIC FRACTURE; HIGH-PRESSURE; SILICON; CRYSTALS; KH2PO4 AB We report the nanosecond time-scale and micron length-scale dynamics of elastic wave, plastic deformation, melt-front and crack propagation during laser-induced damage in the bulk of an optically transparent crystalline solid. Time-delayed probe pulses with wavelengths corresponding to RGB-color filters are used to obtain multiple images during a single damage event. This technique enables "real-time" dynamical studies of complex transient phenomena. (C) 2002 American Institute of Physics. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Jiang, H (reprint author), Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. NR 14 TC 14 Z9 14 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3149 EP 3151 DI 10.1063/1.1511536 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900011 ER PT J AU Jasinski, J Liliental-Weber, Z Estrada, S Hu, E AF Jasinski, J Liliental-Weber, Z Estrada, S Hu, E TI Microstructure of GaAs/GaN interfaces produced by direct wafer fusion SO APPLIED PHYSICS LETTERS LA English DT Article ID DIRECTLY BONDED GAAS; SAPPHIRE; LASERS; INP AB Results of a transmission electron microscopy (TEM) study of directly bonded GaAs/GaN structures obtained by wafer fusion are presented. A large fraction of the interface area was found to be well bonded, with the presence of a thin (1-2 nm) amorphous layer of a native oxide at the bonded interface. The dominant defects found in nonbonded areas were cavities elongated along the [110](GaAs) direction. Plan-view TEM study of well-bonded regions showed the presence of two dislocation networks. The first, formed at the interface to accommodate an unintentional tilt between the fused crystals, consists of a one-dimensional array of wavy dislocations located at interface steps. The second dislocation network, formed to relieve additional strain from the thermal processing of the samples, consists of a two-dimensional, irregularly spaced grid of dislocations formed on the GaAs side that runs parallel to either the [110](GaAs) or [11_0](GaAs) directions. (C) 2002 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RP Jasinski, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 16 TC 21 Z9 25 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3152 EP 3154 DI 10.1063/1.1515116 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900012 ER PT J AU Romero, MJ Gessert, TA Al-Jassim, MM AF Romero, MJ Gessert, TA Al-Jassim, MM TI Carrier diffusion and radiative recombination in CdTe thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLAR-CELLS; CDS/CDTE AB We employed cathodoluminescence spectroscopy and imaging to investigate the carrier diffusion and radiative recombination in CdTe thin films. We observed that carriers excited by the electron beam diffuse by excitons or by free electrons via donor states at low temperatures. The distribution and concentration of these states in the CdTe films were estimated from the dependence on the excitation level of the donor-to-acceptor radiative recombination. (C) 2002 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Romero, MJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 11 TC 15 Z9 15 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3161 EP 3163 DI 10.1063/1.1515882 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900015 ER PT J AU Luebbert, D Arthur, J Sztucki, M Metzger, TH Griffin, PB Patel, JR AF Luebbert, D Arthur, J Sztucki, M Metzger, TH Griffin, PB Patel, JR TI X-ray diffuse scattering study of the kinetics of stacking fault growth and annihilation in boron-implanted silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID TRANSIENT ENHANCED DIFFUSION; THERMAL-OXIDATION; EXTENDED DEFECTS; SI AB Stacking faults in boron-implanted silicon give rise to streaks or rods of scattered x-ray intensity normal to the stacking fault plane. We have used the diffuse scattering rods to follow the growth of faults as a function of time when boron-implanted silicon is annealed in the range of 925 to 1025 degreesC. From the growth kinetics we obtain an activation energy for interstitial migration in silicon: E-I=1.98+/-0.06 eV. Fault intensity and size versus time results indicate that faults do not shrink and disappear, but rather are annihilated by a dislocation reaction mechanism. (C) 2002 American Institute of Physics. C1 Stanford Univ, Stanford Linear Accelerator Ctr, SSRL, Stanford, CA 94309 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Stanford Univ, Integrated Circuits Lab, Stanford, CA 94305 USA. LBL, ALS, Berkeley, CA 94720 USA. RP Luebbert, D (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, SSRL, Stanford, CA 94309 USA. NR 11 TC 6 Z9 6 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3167 EP 3169 DI 10.1063/1.1516239 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900017 ER PT J AU Viehland, D Li, JF Lograsso, TA Ross, A Wuttig, M AF Viehland, D Li, JF Lograsso, TA Ross, A Wuttig, M TI Structural studies of Fe0.81Ga0.19 by reciprocal space mapping SO APPLIED PHYSICS LETTERS LA English DT Article AB Reciprocal lattice mapping has been performed on Fe0.81Ga0.19 crystals by omega-omega/2theta, Psi-phi, and omega-phi scans. A strong elongation of the <001>(c) peak was found along the <110>(c) direction. omega scans revealed short lateral correlation lengths xi along <110>(c) and strong diffuse scattering along the <001>(c). Multiple domains with monoclinic symmetry (angle similar to190degrees) were observed by Psi-phi and omega-phi scans on the (001)(c) face, and were also tilted with respect to each other. The results show an average cubic structure with orthorhombic structural modulations, and two structural domain states that result in a limiting monoclinic symmetry. (C) 2002 American Institute of Physics. C1 Virginia Tech, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. Ames Lab, Ames, IA 50011 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RP Viehland, D (reprint author), Virginia Tech, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. NR 7 TC 9 Z9 9 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3185 EP 3187 DI 10.1063/1.1516231 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900023 ER PT J AU Lee, JS Joo, SK AF Lee, JS Joo, SK TI Role of grain boundaries on hydrogen-induced degradation in lead zirconate titanate thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID FERROELECTRIC PB(ZR,TI)O-3; CAPACITORS; ELECTRODE; PB(ZR AB It is well known that exposing lead zirconate titanate (PZT) thin films to hydrogen severely degrades the electrical properties. This phenomenon has been the subject of intensive study; however, there is no electrical evidence relating the hydrogen-induced degradation with the grain boundaries in the films. In this work, using large-grained PZT thin films (average grain size: 40 mum), we could measure the effects of grain boundary on the hydrogen-induced degradation in PZT thin films by locating the upper Pt electrode (8x8 mum(2)) sequentially from the center of the grain to the grain boundary in a controlled manner. It was found that the grain boundary was mainly responsible for the electrical degradation caused by exposure to the hydrogen. Little degradation with hydrogen exposure was observed when the Pt top electrode was located in the center of the grain. (C) 2002 American Institute of Physics. C1 Seoul Natl Univ, Coll Engn, Sch Mat Sci & Engn, Seoul 151744, South Korea. RP Los Alamos Natl Lab, MST STC, Los Alamos, NM 87545 USA. EM cleancut@snu.ac.kr RI Lee, Jang-Sik/A-6629-2008 OI Lee, Jang-Sik/0000-0002-1096-1783 NR 16 TC 11 Z9 11 U1 0 U2 0 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 OCT 21 PY 2002 VL 81 IS 17 BP 3230 EP 3232 DI 10.1063/1.1516233 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900038 ER PT J AU Smowton, PM Pearce, EJ Schneider, HC Chow, WW Hopkinson, M AF Smowton, PM Pearce, EJ Schneider, HC Chow, WW Hopkinson, M TI Filamentation and linewidth enhancement factor in InGaAs quantum dot lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID POWER; GAIN; NM AB We report measurements of the near-field of broad-area lasers with quantum dot and quantum well active regions designed to emit at 1 mum. The quantum dot devices exhibit less filamentation than comparable quantum well devices, and exhibit a reduction in filamentation as the injection level is increased. This is consistent with a theory that includes the Coulomb coupling between dot and wetting-layer states on a microscopic level. The theory predicts a linewidth enhancement factor from -3 to 1, depending on carrier density and inhomogeneous broadening. (C) 2002 American Institute of Physics. C1 Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Sandia Natl Labs, Semicond Mat & Device Sci Dept, Albuquerque, NM 87185 USA. Univ Sheffield, EPSRC Cent Facil Semicond 3 5, Sheffield S1 3JD, S Yorkshire, England. RP Smowton, PM (reprint author), Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. RI Schneider, Hans Christian/B-9450-2009; Hopkinson, Mark/H-8239-2012; OI Schneider, Hans Christian/0000-0001-7656-4919; Hopkinson, Mark/0000-0002-8097-6913; Smowton, Peter/0000-0002-9105-4842 NR 10 TC 53 Z9 53 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 21 PY 2002 VL 81 IS 17 BP 3251 EP 3253 DI 10.1063/1.1516236 PG 3 WC Physics, Applied SC Physics GA 604MH UT WOS:000178624900045 ER PT J AU Gailer, J George, GN Harris, HH Pickering, IJ Prince, RC Somogyi, A Buttigieg, GA Glass, RS Denton, MB AF Gailer, J George, GN Harris, HH Pickering, IJ Prince, RC Somogyi, A Buttigieg, GA Glass, RS Denton, MB TI Synthesis, purification, and structural characterization of the dimethyldiselenoarsinate anion SO INORGANIC CHEMISTRY LA English DT Article ID SIZE-EXCLUSION CHROMATOGRAPHY; DENSITY-FUNCTIONAL THEORY; ENZYMATIC METHYLATION; POLYATOMIC-MOLECULES; DIMETHYLARSINIC ACID; MAGNETIC-RESONANCE; ARSENIC COMPOUNDS; SELENIUM; GLUTATHIONE; ION AB A novel arsenic-selenium solution species was synthesized by reacting equimolar sodium selenite and sodium dimethylarsinate with 10 mol equiv of glutathione (pH 7.5) in aqueous solution. The solution species showed a single Se-77 NMR resonance at 112.8 ppm. Size-exclusion chromatography (SEC) using an inductively coupled plasma atomic emission spectrometer (ICP-AES) as the simultaneous arsenic-, selenium-, sulfur-, and carbon-specific detector revealed an arsenic-selenium moiety with an As:Se molar ratio of 1:2. Electrospray ionization mass spectrometry (ESI-MS) of the chromatographically purified compound showed a molecular mass peak at m/z 263 in the negative ion mode. Fragmentation of the parent ion (ESI-MS-MS) produced (CH3)(2)As- and Se-2(-) fragments. Arsenic and selenium extended X-ray absorption fine structure spectroscopy (EXAFS) of the purified species revealed two As-C interactions at 1.943 Angstrom and two As-Se interactions at 2.279 Angstrom. On the basis of these results this novel solution species is identified as the dimethyldiselenoarsinate anion. C1 Natl Res Ctr Environm & Hlth, GSF, Inst Ecol Chem, D-85764 Neuherberg, Germany. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Exxon Res & Engn Co, Annandale, NJ 08801 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. RP Gailer, J (reprint author), Natl Res Ctr Environm & Hlth, GSF, Inst Ecol Chem, Ingolstadter Landstr 1, D-85764 Neuherberg, Germany. RI Harris, Hugh/A-4983-2008; George, Graham/E-3290-2013; Pickering, Ingrid/A-4547-2013; OI Prince, Roger/0000-0002-5174-4216; Pickering, Ingrid/0000-0002-0936-2994; Harris, Hugh/0000-0002-3472-8628 NR 51 TC 17 Z9 17 U1 0 U2 5 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 OCT 21 PY 2002 VL 41 IS 21 BP 5426 EP 5432 DI 10.1021/ic0113146 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 605KH UT WOS:000178676700017 PM 12377037 ER PT J AU Bluhm, ME Hay, BP Kim, SS Dertz, EA Raymond, KN AF Bluhm, ME Hay, BP Kim, SS Dertz, EA Raymond, KN TI Corynebactin and a serine trilactone based analogue: Chirality and molecular modeling of ferric complexes SO INORGANIC CHEMISTRY LA English DT Article ID MICROBIAL IRON TRANSPORT; ESCHERICHIA-COLI; COORDINATION CHEMISTRY; ENTEROBACTIN; SIDEROPHORE AB Because the hydrolysis of ferric ion makes it very insoluble in aerobic, near neutral pH environments, most species of bacteria produce siderophores to acquire iron, an essential nutrient. The chirality of the ferric siderophore complex plays an important role in cell recognition, uptake, and utilization. Corynebactin, isolated from Gram-positive bacteria, is structurally similar to enterobactin, a well-known siderophore first isolated from Gram-negative bacteria, but contains L-threonine instead Of L-serine in the trilactone backbone. Corynebactin also contains a glycine spacer unit in each of the chelating arms. A hybrid analogue (serine-corynebactin) has been prepared which has the trilactone ring of enterobactin and the glycine spacer of corynebactin. The chirality and relative conformational stability of the three ferric complexes of enterobactin, corynebactin, and the hybrid have been investigated by molecular modeling (including MM3 and pBP86/DN* density functional theory calculations) and circular dichroism spectra. While enterobactin forms a Lambda-ferric complex, corynebactin is Lambda. The hybrid serine-corynebactin forms a nearly racemic mixture, with the Lambda-conformer in slight excess. Each ferric complex has four possible isomers depending on the metal chirality and the conformation of the trilactone ring. For corynebactin, the energy difference between the two possible Lambda conformations is 2.3 kcal/mol. In contrast, only 1.5 kcal/mol separates the inverted Lambda-and normal Delta-configuration for serine-corynebactin. The small energy difference of the two lowest energy configurations is the likely cause for the racemic mixture found in the CD spectra. Both the addition of a glycine spacer and methylation of the trilactone ring (serine to threonine) favor the Lambda-conformation. These structural changes suffice to change the chirality from all Delta (enterobactin) to all Lambda (corynebactin). The single change (glycine spacer) of the hybrid ferric serine-corynebactin gives a mixture of Delta and Lambda, with the Lambda in slight excess. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Raymond, KN (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIAID NIH HHS [AI 11744] NR 23 TC 19 Z9 19 U1 2 U2 7 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 OCT 21 PY 2002 VL 41 IS 21 BP 5475 EP 5478 DI 10.1021/ic025531y PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 605KH UT WOS:000178676700022 PM 12377042 ER PT J AU Hay, BP Firman, TK AF Hay, BP Firman, TK TI HostDesigner: A program for the de novo structure-based design of molecular receptors with binding sites that complement metal ion guests SO INORGANIC CHEMISTRY LA English DT Article ID MM3 FORCE-FIELD; ALKALINE-EARTH CATIONS; DENOVO DRUG DESIGN; MACROCYCLE INTERACTION; SELECTIVE LIGANDS; RATIONAL DESIGN; KINETIC DATA; MECHANICS CALCULATIONS; TETRAAZA MACROCYCLES; CANDIDATE STRUCTURES AB This paper describes a novel approach to the discovery of host structures with binding sites that complement targeted metal ion guests. This approach uses a de novo structure-based design strategy that couples molecular building algorithms with scoring functions to prioritize candidate structures. The algorithms described herein have been implemented in a program called HostDesigner, the first structure-based design software specifically created for the discovery of metal ion receptors. HostDesigner generates and evaluates millions of candidate structures within minutes, rapidly identifying three-dimensional architectures that position binding sites to provide an optimal interaction with the metal ion. C1 Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Hay, BP (reprint author), Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. NR 71 TC 55 Z9 55 U1 0 U2 13 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 OCT 21 PY 2002 VL 41 IS 21 BP 5502 EP 5512 DI 10.1021/ic0202920 PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 605KH UT WOS:000178676700026 PM 12377046 ER PT J AU Smith, MC Mao, S Wozniak, P Udalski, A Szymanski, M Kubiak, M Pietrzynski, G Soszynski, I Zebrun, K AF Smith, MC Mao, S Wozniak, P Udalski, A Szymanski, M Kubiak, M Pietrzynski, G Soszynski, I Zebrun, K TI Optical gravitational lensing experiment: OGLE-1999-BUL-19 - the first multipeak parallax event SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE gravitational lensing; binaries : general; Galaxy : bulge; Galaxy : centre; Galaxy : kinematics and dynamics ID DIFFERENCE IMAGE-ANALYSIS; GALACTIC MICROLENSING EVENTS; II BULGE DATA; BINARY-SOURCE; BAADES WINDOW; MASS-SPECTRUM; STELLAR MASS; MACHO MASS; PHOTOMETRY; STARS AB We describe a highly unusual microlensing event, OGLE-1999-BUL-19. Unlike most standard microlensing events, this event exhibits multiple peaks in its light curve. The Einstein radius crossing time for this event is approximately 1 yr, which is unusually long. We show that the additional peaks in the light curve can be caused by the very small value for the relative transverse velocity of the lens projected on to the observer plane ((nu) over tilde approximate to 12.5 +/- 1.1 km s(-1)). Since this value is significantly less than the speed of the orbit of the Earth around the Sun (v (+) similar to 30km s (-1)), the motion of the Earth induces these multiple peaks in the light curve. This value for (nu) over tilde is the lowest velocity so far published and we believe that this is the first multiple-peak parallax event ever observed. We also found that the event can be somewhat better fitted by a rotating binary-source model, although this is to be expected since every parallax microlensing event can be exactly reproduced by a suitable binary-source model. A face-on rotating binary-lens model was also identified, but this provides a significantly worse fit. We conclude that the most likely cause for this multipeak behaviour is parallax microlensing rather than microlensing by a binary source. However, this event may be exhibiting a slight binary-source signature in addition to these parallax-induced multiple peaks. With spectroscopic observations it is possible to test this 'parallax plus binary-source' hypothesis and (in the instance that the hypothesis turns out to be correct) to simultaneously fit both models and obtain a measurement of the lens mass. Furthermore, spectroscopic observations could also supply information regarding the lens properties, possibly providing another avenue for determining the lens mass. We also investigated the nature of the blending for this event, and found that the majority of the I-band blending is contributed by a source roughly aligned with the lensed source. This implies that most of the I-band blending is caused by light from the lens or a binary companion to the source. However, in the V band, there appears to be a second blended source 0.35 arcsec away from the lensed source. Hubble Space Telescope observations will be very useful for understanding the nature of the blends. We also suggest that a radial velocity survey of all parallax events will be very useful for further constraining the lensing kinematics and understanding the origins of these events and the excess of long events toward the bulge. C1 Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Warsaw Observ, PL-00478 Warsaw, Poland. Univ Concepcion, Dept Fis, Concepcion, Chile. RP Smith, MC (reprint author), Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England. EM msmith@jb.man.ac.uk; smao@jb.man.ac.uk; wozniak@lanl.gov; udalski@astrouw.edu.pl; msz@astrouw.edu.pl; mk@astrouw.edu.pl; pietrzyn@astrouw.edu.pl; soszynsk@astrouw.edu.pl; zebrun@astrouw.edu.pl NR 58 TC 19 Z9 19 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT 21 PY 2002 VL 336 IS 2 BP 670 EP 684 DI 10.1046/j.1365-8711.2002.05811.x PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 604FK UT WOS:000178605800036 ER PT J AU Kogut, JB Toublan, D Sinclair, DK AF Kogut, JB Toublan, D Sinclair, DK TI The phase diagram of four flavor SU(2) lattice gauge theory at nonzero chemical potential and temperature SO NUCLEAR PHYSICS B LA English DT Article ID CHIRAL PERTURBATION-THEORY; FINITE BARYON DENSITY; QCD-LIKE THEORIES; 2-COLOR QCD; 2 COLORS; QUANTUM CHROMODYNAMICS; ISOSPIN DENSITY; QUARK; SUPERCONDUCTIVITY; CONDENSATION AB SU(2) lattice gauge theory with four flavors of quarks is simulated at nonzero chemical potential mu and temperature T and the results are compared. to the predictions of effective Lagrangians. Simulations on 16(4) lattices indicate that at zero T the theory experiences a second order phase transition to a diquark condensate state. Several methods of analysis, including equation of state fits suggested by Chiral Perturbation Theory, suggest that mean-field scaling describes this critical point. Nonzero T and mu are studied on 12(3) x 6 lattices. For low T, increasing mu takes the system through a line of second order phase transitions to a diquark condensed phase. Increasing T at high mu, the system passes through a line of first order transitions from the diquark phase to the quark-gluon plasma phase. Metastability is found near the first order line. Presumably, there is a tricritical point along this line of transitions. We estimate its position to be consistent with theoretical predictions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. RP Kogut, JB (reprint author), Univ Illinois, Dept Phys, Urbana, IL 61801 USA. NR 42 TC 50 Z9 50 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 OCT 21 PY 2002 VL 642 IS 1-2 BP 181 EP 209 AR PII S0550-3213(02)00678-8 DI 10.1016/S0550-3213(02)00678-8 PG 29 WC Physics, Particles & Fields SC Physics GA 609TJ UT WOS:000178920400008 ER PT J AU Brodsky, SJ Hwang, DS Schmidt, I AF Brodsky, SJ Hwang, DS Schmidt, I TI Initial-state interactions and single-spin asymmetries in Drell-Yan processes SO NUCLEAR PHYSICS B LA English DT Article ID DEEP-INELASTIC SCATTERING; PION-PRODUCTION; DISTRIBUTIONS; REPRESENTATION; ELECTROPRODUCTION; LEPTONS; QCD AB We show that the initial-state interactions from gluon exchange between the incoming quark and the target spectator system lead to leading-twist single-spin asymmetries in the Drell-Yan process H1H2up arrow --> l(+)l(-)X. The QCD initial-state interactions produce a T-odd spin-correlation (S) over right arrowH(2) . (P) over right arrowH(1) x (Q) over right arrow between the target spin and the virtual photon production plane which is not power-law suppressed in the Drell-Yan scaling limit at large photon virtuality Q(2) at fixed x(F). The single-spin asymmetry which arises from the initial-state interactions is not related to the target or projectile transversity distribution deltaq(H)(x, Q). The origin of the single-spin asymmetry in pipup arrow --> l(+)l(-)X is a phase difference between two amplitudes coupling the proton target with J(p)(z) = +/-1/2 to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. The calculation requires the overlap of target light-front wavefunctions with different orbital angular momentum: DeltaL(z) = 1; thus the SSA in the Drell-Yan reaction provides a direct measure of orbital angular momentum in the QCD bound state. The single-spin asymmetry predicted for the Drell-Yan process pip(up arrow) --> l(+)l(-)X is similar to the single-spin asymmetries in deep inelastic semi-inclusive leptoproduction lp(up arrow) --> l'piX which arises from the final-state rescattering of the outgoing quark. The Bjorken-scaling single-spin asymmetries predicted for the Drell-Yan and leptoproduction processes highlight the importance of initial- and final-state interactions for QCD observables. (C) 2002 Published by Elsevier Science B.V. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Sejong Univ, Dept Phys, Seoul 143747, South Korea. Univ Tecn Federico Santa Maria, Dept Fis, Valparaiso, Chile. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM sjbth@slac.stanford.edu; dshwang@sejong.ac.kr; ischmidt@fis.utfsm.cl RI Schmidt, Ivan/J-5920-2012 NR 32 TC 242 Z9 242 U1 0 U2 2 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 OCT 21 PY 2002 VL 642 IS 1-2 BP 344 EP 356 AR PII S0550-3213(02)00617-X DI 10.1016/S0550-3213(02)00617-X PG 13 WC Physics, Particles & Fields SC Physics GA 609TJ UT WOS:000178920400014 ER PT J AU Abanov, A Chubukov, AV Eschrig, M Norman, MR Schmalian, J AF Abanov, A Chubukov, AV Eschrig, M Norman, MR Schmalian, J TI Neutron resonance in the cuprates and its effect on fermionic excitations SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; CONDENSATION ENERGY; LINE-SHAPE; T-C; BI2SR2CACU2O8+DELTA; STATE; PHOTOEMISSION; DISPERSION; SCATTERING AB We argue that the exciton scenario for the magnetic resonance in the cuprate superconductors yields a small spectral weight of the resonance, in agreement with experiment. We show that the small weight is related to its concentration in a small region of momentum and energy. Despite this, we find that a large fermionic self-energy can indeed be generated by a resonance with such properties, i.e., the scattering from the resonance substantially affects the electronic properties of the cuprates below T-c. C1 Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Karlsruhe, Inst Theoret Festkorperphys, D-76128 Karlsruhe, Germany. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Abanov, A (reprint author), Los Alamos Natl Lab, Div Theory, MS B262, Los Alamos, NM 87545 USA. RI Eschrig, Matthias/B-4786-2009; Schmalian, Joerg/H-2313-2011; Norman, Michael/C-3644-2013 NR 51 TC 80 Z9 80 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 2002 VL 89 IS 17 AR 177002 DI 10.1103/PhysRevLett.89.177002 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500050 PM 12398698 ER PT J AU Abazov, VM Abbott, B Abdesselam, A Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Ahmed, SN Alexeev, GD Alton, A Alves, GA Amos, N Anderson, EW Arnoud, Y Avila, C Baarmand, MM Babintsev, VV Babukhadia, L Bacon, TC Baden, A Baldin, B Balm, PW Banerjee, S Barberis, E Baringer, P Barreto, J Bartlett, JF Bassler, U Bauer, D Bean, A Beaudette, F Begel, M Belyaev, A Beri, SB Bernardi, G Bertram, I Besson, A Beuselinck, R Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blekman, F Blessing, S Boehnlein, A Bojko, NI Borcherding, F Bos, K Bose, T 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 Christenson, JH Chung, M Claes, D Clark, AR Coney, L Connolly, B Cooper, WE Coppage, D Crepe-Renaudin, S Cummings, MAC Cutts, D Davis, GA Davis, K De, K de Jong, SJ Del Signore, K Demarteau, M Demina, R Demine, P Denisov, D Denisov, SP Desai, S Diehl, HT Diesburg, M Doulas, S Ducros, Y Dudko, LV Duensing, S Duflot, L Dugad, SR Duperrin, A Dyshkant, A Edmunds, D Ellison, J Eltzroth, JT 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 Filthaut, F Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Fox, H Frame, KC Fu, S Fuess, S Gallas, E Galyaev, AN Gao, M Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gilmartin, R Ginther, G Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Graham, G Grannis, PD Green, JA Greenlee, H Greenwood, ZD Grinstein, S Groer, L Grunendahl, S Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinmiller, JM Heinson, AP Heintz, U Hildreth, MD Hirosky, R Hobbs, JD Hoeneisen, B Huang, Y Iashvili, I Illingworth, R Ito, AS Jaffre, M Jain, S Jesik, R Johns, K Johnson, M Jonckheere, A Jostlein, H Juste, A Kahl, W Kahn, S Kajfasz, E Kalinin, AM Karmanov, D Karmgard, D Kehoe, R Khanov, A Kharchilava, A Kim, SK Klima, B Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kothari, B Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krivkova, P Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Kupco, A Kuznetsov, VE Landsberg, G Lee, WM Leflat, A Leggett, C Lehner, F Leonidopoulos, C Li, J Li, QZ Li, X Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lucotte, A Lueking, L Lundstedt, C Luo, C Maciel, AKA Madaras, RJ Malyshev, VL Manankov, V Mao, HS Marshall, T Martin, MI Mauritz, KM Mayorov, AA McCarthy, R McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Moore, RW Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Naumann, NA Neal, HA Negret, JP Negroni, S Nunnemann, T O'Neil, D Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Papageorgiou, K Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, O Petroff, P Piegaia, R Pope, BG Popkov, E Prosper, HB Protopopescu, S Przybycien, MB Qian, J Raja, R Rajagopalan, S Ramberg, E Rapidis, PA Reay, NW Reucroft, S Ridel, M Rijssenbeek, M Rizatdinova, F Rockwell, T Roco, M Royon, C Rubinov, P Ruchti, R Rutherfoord, J Sabirov, BM Sajot, G Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sen, N Shabalina, E 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, Y Sorin, V Sosebee, M Sotnikova, N Soustruznik, K Souza, M Stanton, NR Steinbruck, G Stephens, RW Stichelbaut, F Stoker, D Stolin, V Stone, A Stoyanova, DA Strang, MA Strauss, M Strovink, M Stutte, L Sznajder, A Talby, M Taylor, W Tentindo-Repond, S Tripathi, SM Trippe, TG Turcot, AS Tuts, PM Vaniev, V Van Kooten, R Varelas, N Vertogradov, LS Villeneuve-Seguier, F Volkov, AA Vorobiev, AP Wahl, HD Wang, H Wang, ZM Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wijngaarden, DA Willis, S Wimpenny, SJ Womersley, J Wood, DR Xu, Q Yamada, R Yamin, P Yasuda, T Yatsunenko, YA Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zhang, X Zheng, H Zhou, B Zhou, Z Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A AF Abazov, VM Abbott, B Abdesselam, A Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Ahmed, SN Alexeev, GD Alton, A Alves, GA Amos, N Anderson, EW Arnoud, Y Avila, C Baarmand, MM Babintsev, VV Babukhadia, L Bacon, TC Baden, A Baldin, B Balm, PW Banerjee, S Barberis, E Baringer, P Barreto, J Bartlett, JF Bassler, U Bauer, D Bean, A Beaudette, F Begel, M Belyaev, A Beri, SB Bernardi, G Bertram, I Besson, A Beuselinck, R Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blekman, F Blessing, S Boehnlein, A Bojko, NI Borcherding, F Bos, K Bose, T 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 Christenson, JH Chung, M Claes, D Clark, AR Coney, L Connolly, B Cooper, WE Coppage, D Crepe-Renaudin, S Cummings, MAC Cutts, D Davis, GA Davis, K De, K de Jong, SJ Del Signore, K Demarteau, M Demina, R Demine, P Denisov, D Denisov, SP Desai, S Diehl, HT Diesburg, M Doulas, S Ducros, Y Dudko, LV Duensing, S Duflot, L Dugad, SR Duperrin, A Dyshkant, A Edmunds, D Ellison, J Eltzroth, JT 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 Filthaut, F Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Fox, H Frame, KC Fu, S Fuess, S Gallas, E Galyaev, AN Gao, M Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gilmartin, R Ginther, G Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Graham, G Grannis, PD Green, JA Greenlee, H Greenwood, ZD Grinstein, S Groer, L Grunendahl, S Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinmiller, JM Heinson, AP Heintz, U Hildreth, MD Hirosky, R Hobbs, JD Hoeneisen, B Huang, Y Iashvili, I Illingworth, R Ito, AS Jaffre, M Jain, S Jesik, R Johns, K Johnson, M Jonckheere, A Jostlein, H Juste, A Kahl, W Kahn, S Kajfasz, E Kalinin, AM Karmanov, D Karmgard, D Kehoe, R Khanov, A Kharchilava, A Kim, SK Klima, B Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kothari, B Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krivkova, P Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Kupco, A Kuznetsov, VE Landsberg, G Lee, WM Leflat, A Leggett, C Lehner, F Leonidopoulos, C Li, J Li, QZ Li, X Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lucotte, A Lueking, L Lundstedt, C Luo, C Maciel, AKA Madaras, RJ Malyshev, VL Manankov, V Mao, HS Marshall, T Martin, MI Mauritz, KM Mayorov, AA McCarthy, R McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Moore, RW Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Naumann, NA Neal, HA Negret, JP Negroni, S Nunnemann, T O'Neil, D Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Papageorgiou, K Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, O Petroff, P Piegaia, R Pope, BG Popkov, E Prosper, HB Protopopescu, S Przybycien, MB Qian, J Raja, R Rajagopalan, S Ramberg, E Rapidis, PA Reay, NW Reucroft, S Ridel, M Rijssenbeek, M Rizatdinova, F Rockwell, T Roco, M Royon, C Rubinov, P Ruchti, R Rutherfoord, J Sabirov, BM Sajot, G Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sen, N Shabalina, E 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, Y Sorin, V Sosebee, M Sotnikova, N Soustruznik, K Souza, M Stanton, NR Steinbruck, G Stephens, RW Stichelbaut, F Stoker, D Stolin, V Stone, A Stoyanova, DA Strang, MA Strauss, M Strovink, M Stutte, L Sznajder, A Talby, M Taylor, W Tentindo-Repond, S Tripathi, SM Trippe, TG Turcot, AS Tuts, PM Vaniev, V Van Kooten, R Varelas, N Vertogradov, LS Villeneuve-Seguier, F Volkov, AA Vorobiev, AP Wahl, HD Wang, H Wang, ZM Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wijngaarden, DA Willis, S Wimpenny, SJ Womersley, J Wood, DR Xu, Q Yamada, R Yamin, P Yasuda, T Yatsunenko, YA Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zhang, X Zheng, H Zhou, B Zhou, Z Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A CA D0 Collaboration TI Search for R-parity violating supersymmetry in two-muon and four-jet topologies SO PHYSICAL REVIEW LETTERS LA English DT Article ID SIGN DILEPTON SIGNATURE; P(P)OVER-BAR COLLISIONS; SUPERGRAVITY; CHANNEL; PHYSICS; STATES; WEAK AB We present results of a search for R-parity-violating decay of the neutralino (χ) over tilde (0)(1), taken as the lightest supersymmetric particle, to a muon and two jets. The decay proceeds through a lepton-number violating coupling lambda(2jk)' (j = 1,2; k = 1,2,3), with R-parity conservation in all other production and decay processes. In the absence of candidate events from 77.5 +/- 3.9 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron in p (p) over bar collisions at roots = 1.8 TeV, and with an expected background of 0.18 +/- 0.03 +/- 0.02 events, we set limits on squark and gluino masses within the framework of the minimal low-energy supergravity-supersymmetry model. C1 Joint Inst Nucl Res, Dubna, Russia. Univ Buenos Aires, Buenos Aires, DF, Argentina. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Los Andes, Bogota, Colombia. Charles Univ, Ctr Particle Phys, Prague, Czech Republic. Acad Sci Czech Republ, Inst Phys, Ctr Particle Phys, Prague, Czech Republic. Univ San Francisco Quito, Quito, Ecuador. Univ Grenoble 1, CNRS, IN2P3, Inst Sci Nucl, Grenoble, France. Univ Mediterranee, CNRS, IN2P3, CPPM, Marseille, France. CNRS, IN2P3, Lab Accelerateur Lineaire, Orsay, France. Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, CNRS, IN2P3, Paris, France. CEA, Serv Phys Particule, DAPNIA, Saclay, France. Univ Mainz, Inst Phys, D-6500 Mainz, Germany. 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. FOM, Inst NIKHEF, NL-1098 SJ Amsterdam, Netherlands. Univ Amsterdam, NIKHEF, Amsterdam, Netherlands. Univ Nijmegen, NIKHEF, Nijmegen, Netherlands. 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 London Imperial Coll Sci Technol & Med, London, England. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, 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. Fermilab Natl Accelerator Lab, Batavia, IL 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 Virginia, Charlottesville, VA 22901 USA. Univ Washington, Seattle, WA 98195 USA. RP Abazov, VM (reprint author), Joint Inst Nucl Res, Dubna, Russia. RI Canelli, Florencia/O-9693-2016; Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; Shivpuri, R K/A-5848-2010; 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; Santoro, Alberto/E-7932-2014 OI Canelli, Florencia/0000-0001-6361-2117; 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 28 TC 0 Z9 0 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 OCT 21 PY 2002 VL 89 IS 17 AR 171801 DI 10.1103/PhysRevLett.89.171801 PG 6 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500010 ER PT J AU Aubin, H Greene, LH Jian, S Hinks, DG AF Aubin, H Greene, LH Jian, S Hinks, DG TI Andreev bound states at the onset of phase coherence in Bi2Sr2CaCu2O8 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-T-C; HIGH-TEMPERATURE SUPERCONDUCTORS; YBA2CU3O7 TUNNEL-JUNCTIONS; TIME-REVERSAL SYMMETRY; SURFACE-STATES; OVERDOPED BI2SR2CACU2O8+DELTA; SPECTROSCOPY; DEPENDENCE; GAP AB A new technique of planar tunneling spectroscopy has been developed to access the in-plane density of states of optimally doped Bi2Sr2CaCu2O8 single crystals. The low energy spectrum is observed to depend on crystallographic orientation. When tunnel current is injected nominally along the Cu-Cu bond direction, a zero-bias conductance peak is observed to appear simultaneously with the onset of bulk superconductivity. These data demonstrate the existence of surface-induced states in this system and confirm the d-wave symmetry of the superconducting order parameter. C1 Univ Illinois, Loomis Lab Phys, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Aubin, H (reprint author), Ecole Super Phys & Chim Ind Ville Paris, LPQ, 10 Rue Vauquelin, F-75231 Paris, France. NR 26 TC 37 Z9 37 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 OCT 21 PY 2002 VL 89 IS 17 AR 177001 DI 10.1103/PhysRevLett.89.177001 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500049 PM 12398697 ER PT J AU Karkuszewski, ZP Jarzynski, C Zurek, WH AF Karkuszewski, ZP Jarzynski, C Zurek, WH TI Quantum chaotic environments, the butterfly effect, and decoherence SO PHYSICAL REVIEW LETTERS LA English DT Article AB We investigate the sensitivity of quantum systems that are chaotic in a classical limit to small perturbations of their equations of motion. This sensitivity, originally studied in the context of defining quantum chaos, is relevant to decoherence when the environment has a chaotic classical counterpart. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Karkuszewski, ZP (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Jarzynski, Christopher/B-4490-2009 OI Jarzynski, Christopher/0000-0002-3464-2920 NR 17 TC 74 Z9 74 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 OCT 21 PY 2002 VL 89 IS 17 AR 170405 DI 10.1103/PhysRevLett.89.170405 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500005 PM 12398653 ER PT J AU Kim, YJ Hill, JP Burns, CA Wakimoto, S Birgeneau, RJ Casa, D Gog, T Venkataraman, CT AF Kim, YJ Hill, JP Burns, CA Wakimoto, S Birgeneau, RJ Casa, D Gog, T Venkataraman, CT TI Resonant inelastic X-ray scattering study of charge excitations in La2CuO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID TEMPERATURE-DEPENDENCE; ELECTRONIC-STRUCTURE; CUO2 PLANE; SR2CUO2CL2; EXCITONS; SPECTRUM; ND2CUO4; OXIDES; MODEL AB We report a resonant inelastic x-ray scattering study of the dispersion relations of charge-transfer excitations in insulating La2CuO4. These data reveal two peaks, both of which show two-dimensional characteristics. The lowest energy excitation has a gap energy of similar to2.2 eV at the zone enter, and a dispersion of similar to1 eV. The spectral weight of this mode becomes dramatically smaller around (pi, pi). The second peak shows a smaller dispersion (similar to0.5 eV) with a zone-center energy of similar to3.9 eV. We argue that these are both highly dispersive exciton modes damped by the presence of the electron-hole continuum. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Argonne Natl Lab, Adv Photon Source, CMC CAT, Argonne, IL 60439 USA. RP Kim, YJ (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Kim, Young-June /G-7196-2011; Casa, Diego/F-9060-2016 OI Kim, Young-June /0000-0002-1172-8895; NR 22 TC 100 Z9 101 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 2002 VL 89 IS 17 AR 177003 DI 10.1103/PhysRevLett.89.177003 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500051 PM 12398699 ER PT J AU Leemans, WP Catravas, P Esarey, E Geddes, CGR Toth, C Trines, R Schroeder, CB Shadwick, BA van Tilborg, J Faure, J AF Leemans, WP Catravas, P Esarey, E Geddes, CGR Toth, C Trines, R Schroeder, CB Shadwick, BA van Tilborg, J Faure, J TI Electron-yield enhancement in a laser-wakefield accelerator driven by asymmetric laser pulses SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAMAN-SCATTERING; NONLINEAR OPTICS; PLASMAS; INSTABILITIES; GENERATION; DYNAMICS; GASES AB The effect of asymmetric laser pulses on electron yield from a laser wakefield accelerator has been experimentally studied using >10(19) cm(-3) plasmas and a 10 TW, >45 fs, Ti:Al2O3 laser. The laser pulse shape was controlled through nonlinear chirp with a grating pair compressor. Pulses (76 fs FWHM) with a steep rise and positive chirp were found to significantly enhance the electron yield compared to pulses with a gentle rise and negative chirp. Theory and simulation show that fast rising pulses can generate larger amplitude wakes that seed the growth of the self-modulation instability, and that frequency chirp is of minimal importance for the experimental parameters. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Tech Univ Eindhoven, NL-5600 MB Eindhoven, Netherlands. RP Leemans, WP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 23 TC 118 Z9 120 U1 3 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 OCT 21 PY 2002 VL 89 IS 17 AR 174802 DI 10.1103/PhysRevLett.89.174802 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500027 PM 12398675 ER PT J AU Seka, W Baldis, HA Fuchs, J Regan, SP Meyerhofer, DD Stoeckl, C Yaakobi, B Craxton, RS Short, RW AF Seka, W Baldis, HA Fuchs, J Regan, SP Meyerhofer, DD Stoeckl, C Yaakobi, B Craxton, RS Short, RW TI Multibeam stimulated Brillouin scattering from hot, solid-target plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID CROSSED LASER-BEAMS; INHOMOGENEOUS COLLISIONAL PLASMAS; SCALE-LENGTH PLASMAS; RAMAN-SCATTERING; RELEVANT; FUSION AB We report on multibeam, laser-plasma interaction experiments in plasmas relevant to future direct-drive-ignition experiments. Six interaction beams are incident on preformed plasmas containing critical density. Stimulated Brillouin scattering (SBS) shows strong evidence of electromagnetic wave seeding of side- and backscattering. The data are also consistent with shared ion waves driven by the six symmetrically arranged interaction beams. Early SBS quenching is observed and attributed to the hydrodynamics of the plasma. C1 Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. Lawrence Livermore Natl Lab, ILSA, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 94550 USA. Ecole Polytech, LULI, F-91128 Palaiseau, France. RP Seka, W (reprint author), Univ Rochester, Laser Energet Lab, 250 E River Rd, Rochester, NY 14623 USA. NR 25 TC 34 Z9 34 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 OCT 21 PY 2002 VL 89 IS 17 AR 175002 DI 10.1103/PhysRevLett.89.175002 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500029 PM 12398677 ER PT J AU Smerzi, A Trombettoni, A Kevrekidis, PG Bishop, AR AF Smerzi, A Trombettoni, A Kevrekidis, PG Bishop, AR TI Dynamical superfluid-insulator transition in a chain of weakly coupled Bose-Einstein condensates SO PHYSICAL REVIEW LETTERS LA English DT Article ID DISCRETE SOLITONS; OPTICAL LATTICES; TUNNEL ARRAYS; INSTABILITIES; ATOMS AB We predict a dynamical classical superfluid-insulator transition in a Bose-Einstein condensate trapped in an optical and a magnetic potential. In the tight-binding limit, this system realizes an array of weakly coupled condensates driven by an external harmonic field. For small displacements of the parabolic trap about the equilibrium position, the condensates coherently oscillate in the array. For large displacements, the condensates remain localized on the side of the harmonic trap with a randomization of the relative phases. The superfluid-insulator transition is due to a discrete modulational instability, occurring when the condensate center of mass velocity is larger than a critical value. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Ist Nazl Fis Mat, I-34014 Trieste, Italy. Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. Univ Massachusetts, Dept Math & Stat, Amherst, MA 01003 USA. RP Smerzi, A (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 26 TC 251 Z9 254 U1 1 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 2002 VL 89 IS 17 AR 170402 DI 10.1103/PhysRevLett.89.170402 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500002 PM 12398650 ER PT J AU Vajk, OP Greven, M AF Vajk, OP Greven, M TI Quantum versus geometric disorder in a two-dimensional Heisenberg antiferromagnet SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-LIQUID BEHAVIOR; ISING SPIN CHAINS; PHASE-TRANSITION; MONTE-CARLO; GRIFFITHS SINGULARITIES; NONMAGNETIC IMPURITIES; NEUTRON-SCATTERING; SQUARE-LATTICE; MODEL; GLASS AB We present a numerical study of the spin-1/2 bilayer Heisenberg antiferromagnet with random interlayer dimer dilution. From the temperature dependence of the uniform susceptibility and a scaling analysis of the spin correlation length we deduce the ground state phase diagram as a function of nonmagnetic impurity concentration p and bilayer coupling g. At the site percolation threshold, there exists a multicritical point at small but nonzero bilayer coupling g(m) = 0.15(3). The magnetic properties of the single-layer material La2Cu1-p(Zn,Mg)(p)O-4 near the percolation threshold appear to be controlled by the proximity to this new quantum critical point. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Vajk, OP (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NR 41 TC 27 Z9 27 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 2002 VL 89 IS 17 AR 177202 DI 10.1103/PhysRevLett.89.177202 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500054 PM 12398702 ER PT J AU Zhou, F Wu, JH Babzien, M Ben-Zvi, I Malone, R Murphy, JB Wang, XJ Woodle, MH Yakimenko, V AF Zhou, F Wu, JH Babzien, M Ben-Zvi, I Malone, R Murphy, JB Wang, XJ Woodle, MH Yakimenko, V TI Surface-roughness wakefield measurements at Brookhaven Accelerator Test Facility SO PHYSICAL REVIEW LETTERS LA English DT Article AB An experiment has been carried out at the Brookhaven Accelerator Test Facility to investigate the effect of a surface-roughness wakefield in narrow beam tubes with artificially created bumps. The measurements show that the synchronous modes decay significantly due to the randomization of the roughness pattern. It is pointed out that this decay mechanism has not been investigated in the previous experiment at DESY and the investigators' conclusion does not apply for surface-roughness wakefields in real surfaces. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RP Zhou, F (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 18 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 2002 VL 89 IS 17 AR 174801 DI 10.1103/PhysRevLett.89.174801 PG 4 WC Physics, Multidisciplinary SC Physics GA 602AX UT WOS:000178483500026 PM 12398674 ER PT J AU Casson, JL Wang, L Libatique, NJC Jain, RK Scrymgeour, DA Gopalan, V Gahagan, KT Sander, RK Robinson, JM AF Casson, JL Wang, L Libatique, NJC Jain, RK Scrymgeour, DA Gopalan, V Gahagan, KT Sander, RK Robinson, JM TI Near-IR tunable laser with an integrated LiTaO3 electro-optic deflector SO APPLIED OPTICS LA English DT Article ID NARROW-LINEWIDTH; FIBER LASER AB We report the successful demonstration of a near-IR tunable laser (1525.4-1558.2 nm) that uses an integrated LiTaO3 deflector in combination with a reflection grating as an electronically tunable filter. The electro-optic deflector is a unique integrated optical device and consists of a horn-shaped array of electro-optic prisms in series. The almost 33 nm of tuning covers a wavelength region of high interest to the communications industry (1527-1550 nm). (C) 2002 Optical Society of America. C1 Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. Penn State Univ, University Pk, PA 16802 USA. Corning Inc, Corning, NY 14831 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. EM casson@lanl.gov RI Scrymgeour, David/C-1981-2008 NR 15 TC 9 Z9 10 U1 1 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 2002 VL 41 IS 30 BP 6416 EP 6419 DI 10.1364/AO.41.006416 PG 4 WC Optics SC Optics GA 605GF UT WOS:000178668700019 PM 12396194 ER PT J AU Adams, M AF Adams, M TI Evaluation of three unstructured multigrid methods on 3D finite element problems in solid mechanics SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE unstructured multigrid; algebraic multigrid; parallel sparse solvers; finite element solvers ID BOUNDARY-VALUE-PROBLEMS; QUASI-UNIFORM MESHES; AGGREGATION; EQUATIONS; ALGORITHMS; SOLVER AB Multigrid has been a popular solver method for finite element and finite difference problems with regular grids for over 20 years. The application of multigrid to unstructured grid problems, in which it is often difficult or impossible for the application to provide coarse grids, is not as well understood. In particular, methods that are designed to require only data that are easily available in most finite element applications (i.e. fine grid data), constructing the grid transfer operators and coarse grid operators internally, are of practical interest. We investigate three unstructured multigrid methods that show promise for challenging problems in 3D elasticity: (1) non-nested geometric multigrid, (2) smoothed aggregation, and (3) plain aggregation algebraic multigrid. This paper evaluates the effectiveness of these three methods on several unstructured grid problems in 3D elasticity with up to 76 million degrees of freedom. Published in 2002 by John Wiley Sons, Ltd. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Adams, M (reprint author), Sandia Natl Labs, MS 9417, Livermore, CA 94551 USA. NR 38 TC 37 Z9 37 U1 1 U2 1 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 OCT 20 PY 2002 VL 55 IS 5 BP 519 EP 534 DI 10.1002/nme.506 PG 22 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 595QY UT WOS:000178121300002 ER PT J AU Jia, JF Liu, X Li, SC Wang, JZ Li, JL Liu, H Pan, MH Dou, RF Xue, QK Li, ZQ Zhang, SB AF Jia, JF Liu, X Li, SC Wang, JZ Li, JL Liu, H Pan, MH Dou, RF Xue, QK Li, ZQ Zhang, SB TI Artificial metal nanocluster crystals SO MODERN PHYSICS LETTERS B LA English DT Review ID NANOCRYSTAL SUPERLATTICES; NANOSTRUCTURE; COBALT; GOLD AB Artificial metal nano-cluster crystals, (i.e. periodic lattices consisting of identical metal nanoclusters) were fabricated using a novel technique in which surface mediated magic clustering was used to achieve identical cluster size, while the Si(111)-7 x 7 surface was used as a template for ordering the clusters. The universality of this strategy was demonstrated by fabricating more than 10 different nanocluster arrays with different metals and alloys. The atomic structures, formation mechanism and stability of the nanoclusters were studied with in situ scanning tunneling microscopy combined with first-principles total energy calculations. Our study shows that delicate control of growth kinetics is extremely important for cluster crystal fabrication. C1 Chinese Acad Sci, Inst Phys, State Key Lab Surface Phys, Beijing 100080, Peoples R China. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Chinese Acad Sci, Inst Phys, State Key Lab Surface Phys, POB 603, Beijing 100080, Peoples R China. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 21 TC 3 Z9 4 U1 3 U2 19 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-9849 EI 1793-6640 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD OCT 20 PY 2002 VL 16 IS 23-24 BP 889 EP 894 DI 10.1142/S0217984902004408 PG 6 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 618MZ UT WOS:000179423000003 ER PT J AU Ball, MJ Lucas, CA Markovic, NM Stamenkovic, V Ross, PN AF Ball, MJ Lucas, CA Markovic, NM Stamenkovic, V Ross, PN TI From sub-monolayer to multilayer - an in situ X-ray diffraction study of the growth of Pd films on Pt(111) SO SURFACE SCIENCE LA English DT Article DE surface structure, morphology, roughness, and topography; surface relaxation and reconstruction; platinum; palladium; X-ray scattering, diffraction and reflection; solid-liquid interfaces; electrochemical methods ID IRREVERSIBLY ADSORBED PALLADIUM; AU(111) ELECTRODE SURFACE; ACID-SOLUTIONS; ADSORPTION; BEHAVIOR; AU(HKL); ELECTROCHEMISTRY; DEPOSITION; OXIDATION; KINETICS AB The structure of electrochemically deposited Pd thin films on the Pt(111) electrode surface has been studied by a combination of cyclic voltammetry (CV) and in situ synchrotron surface X-ray scattering. The films were examined at successively higher levels of thickness, ranging from the sub-monolayer regime to the n ML (n > 2) regime. We found that on top of a pseudomorphic monolayer film, Pd forms three-dimensional islands which, in the n ML (n > 2) regime are described using a half-Lorentzian distribution of layer occupation. These islands provide the large number of Pd step sites that give rise to the peak in the CV at 0.3 V. The deposition of Pd onto Pt(1 11), therefore, proceeds via a pseudomorphic Stranski-Krastanov growth mode. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Lucas, CA (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. OI Lucas, Christopher/0000-0001-5743-3868 NR 26 TC 42 Z9 45 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 20 PY 2002 VL 518 IS 3 BP 201 EP 209 AR PII S0039-6028(02)02122-2 DI 10.1016/S0039-6028(02)02122-2 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 604ZY UT WOS:000178652000005 ER PT J AU Dernburg, AF Karpen, GH AF Dernburg, AF Karpen, GH TI A chromosome RNAissance SO CELL LA English DT Review ID PROTEIN AB In RNA-mediated interference (RNAI), double-stranded RNAs (dsRNAs) target complementary mRNAs for degradation. New work demonstrates that essential chromosomal functions are mediated through RNAi protein components and short RNAs, which alter chromosome function at specific DNA loci via histone modification. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Salk Inst Biol Studies, MCBL, La Jolla, CA 92037 USA. RP Dernburg, AF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Dernburg, Abby/0000-0001-8037-1079 FU NIGMS NIH HHS [R01 GM054549, R01 GM054549-04] NR 17 TC 40 Z9 47 U1 0 U2 0 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD OCT 18 PY 2002 VL 111 IS 2 BP 159 EP 162 DI 10.1016/S0092-8674(02)01039-5 PG 4 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 606UX UT WOS:000178753500005 PM 12408860 ER PT J AU Ramachander, R Kim, CA Phillips, ML Mackereth, CD Thanos, CD McIntosh, LP Bowie, JU AF Ramachander, R Kim, CA Phillips, ML Mackereth, CD Thanos, CD McIntosh, LP Bowie, JU TI Oligomerization-dependent association of the SAM domains from Schizosaccharomyces pombe Byr2 and Ste4 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PROTEIN-KINASE; TRANSCRIPTION FACTOR; CRYSTAL-STRUCTURE; TYROSINE KINASE; HUMAN LEUKEMIA; LAC REPRESSOR; TEL; RECEPTOR; IDENTIFICATION; YEAST AB SAM (sterile alpha motif) domains are protein-protein interaction modules found in a large number of regulatory proteins. Byr2 and Ste4 are two SAM domain-containing proteins in the mating pheromone response pathway of the fission yeast, Schizosaccharomyces pombe. Byr2 is a mitogen-activated protein kinase kinase kinase that is regulated by Ste4. Tu et al (Tu, H., Barr, M., Dong, D. L., and Wigler, M. (1997) Mol. Cell. Biol. 17, 5876-5887) showed that the isolated SAM domain of Byr2 binds a fragment of Ste4 that contains both a leucine zipper (Ste4-LZ) domain as well as a SAM domain, suggesting that Byr2-SAM and Ste4-SAM may form a hetero-oligomer. Here, we show that the individual SAM domains of Ste4 and Byr2 are monomeric at low concentrations and bind to each other in a 1:1 stoichiometry with a relatively weak dissociation constant of 56 +/- 3 mum. Inclusion of the Ste4-LZ domain, which determines the oligomeric state of Ste4, has a dramatic effect on binding affinity, however. We find that the Ste4-LZ domain is trimeric and, when included with the Ste4-SAM domain, yields a 3:1 Ste4-LZ-SAM:Byr2-SAM complex with a tight dissociation constant of 19 +/- 4 nm. These results suggest that the Ste4-LZ-SAM protein may recognize multiple binding sites on Byr2-SAM, indicating a new mode of oligomeric organization for SAM domains. The fact that high affinity binding occurs only with the addition of an oligomerization domain suggests that it may be necessary to include ancillary oligomerization modules when searching for binding partners of SAM domains. C1 Univ Calif Los Angeles, Dept Chem & Biochem, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, US DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Univ British Columbia, Dept Biochem, Vancouver, BC V6T 1Z3, Canada. Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z3, Canada. Univ British Columbia, Biotechnol Lab, Vancouver, BC V6T 1Z3, Canada. Sunesis Pharmaceut, San Francisco, CA 94080 USA. RP Bowie, JU (reprint author), Univ Calif Los Angeles, Dept Chem & Biochem, Inst Mol Biol, Boyer Hall,611 Charles E Young Dr E, Los Angeles, CA 90095 USA. RI Mackereth, Cameron/F-7946-2013 OI Mackereth, Cameron/0000-0002-0776-7947 FU NCI NIH HHS [R01CA81000] NR 46 TC 31 Z9 31 U1 0 U2 3 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 18 PY 2002 VL 277 IS 42 BP 39585 EP 39593 DI 10.1074/jcb.M207273200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 605EA UT WOS:000178662500069 PM 12171939 ER PT J AU Ben-Naim, E Krapivsky, PL AF Ben-Naim, E Krapivsky, PL TI Growth and structure of stochastic sequences SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID RANDOM FIBONACCI SEQUENCES AB We introduce a class of stochastic integer sequences. In these sequences, every element is a sum of two previous elements, at least one of which is chosen randomly. The interplay between randomness and memory underlying these sequences leads to a wide variety of behaviours ranging from stretched exponential to log-normal to algebraic growth. Interestingly, the set of all possible sequence values has an intricate structure. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. RP Ben-Naim, E (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Ben-Naim, Eli/C-7542-2009; Krapivsky, Pavel/A-4612-2014 OI Ben-Naim, Eli/0000-0002-2444-7304; NR 12 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD OCT 18 PY 2002 VL 35 IS 41 BP L557 EP L563 AR PII S0305-4470(02)52442-2 DI 10.1088/0305-4470/35/41/101 PG 7 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 613WN UT WOS:000179154600001 ER PT J AU Tuzun, RE Noid, DW Sumpter, BG Yang, C AF Tuzun, RE Noid, DW Sumpter, BG Yang, C TI Normal coordinate analysis for polymer systems: Capabilities and new opportunities SO MACROMOLECULAR THEORY AND SIMULATIONS LA English DT Review DE Hessian matrix; molecular dynamics; normal coordinate analysis; polyethylene; sparse matrix diagonalization ID MOLECULAR MECHANICS CALCULATIONS; POTENTIAL-ENERGY SURFACES; NORMAL-MODE; ISOTACTIC POLYSTYRENE; P-BENZOQUINONE; VIBRATIONAL POLARIZABILITIES; MACROMOLECULAR SYSTEMS; PROJECTION ANALYSIS; LINEAR-POLYMERS; IONIC MELTS AB Feature Article: Normal coordinate analysis is an important tool in studying the structure, dynamics, and physical properties of polymer systems. IN this article the capabilities of normal coordinate analysis (NCA) are explored in some detail. The use of the eigenvalues and eigenvectors from NCA is catalogued for a wide variety of purposes for assigning or interpreting polymer spectra, for structural determination, for constructing force fields, for computing heat capacity and other thermodynamic properties, and for computing other physical properties. Examples are given for crystals, melts, and amorphous systems. Also described are methods for characterizing the normal mode vectors that are especially useful for larger systems, in which a large amount of data must be analyzed or where visualization or animation fails. Finally, a recently developed method for eliminating negative eigenvalues in systems with tens of thousands of atoms, trajectory averaging, is presented. Also described are several advances in numerical linear algebra for speeding up the diagonalization phase and for computing physical properties without requiring full diagonalization of the Hessian matrix. C1 SUNY Coll Brockport, Dept Computat Sci, Brockport, NY 14420 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. RP Tuzun, RE (reprint author), SUNY Coll Brockport, Dept Computat Sci, Brockport, NY 14420 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 125 TC 3 Z9 3 U1 0 U2 4 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1022-1344 J9 MACROMOL THEOR SIMUL JI Macromol. Theory Simul. PD OCT 18 PY 2002 VL 11 IS 7 BP 711 EP 728 DI 10.1002/1521-3919(20020901)11:7<711::AID-MATS711>3.0.CO;2-L PG 18 WC Polymer Science SC Polymer Science GA 613GQ UT WOS:000179124900001 ER PT J AU Khalil, HSA Levon, K AF Khalil, HSA Levon, K TI Novel chemical methods for the infiltration of opal particles with electrically conductive polyaniline polymers SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE opal; photonic; polyaniline; infiltration ID PHOTONIC CRYSTALS; COLLOIDAL CRYSTALS; OPTICAL-PROPERTIES; BANDS AB Chemical methods for successfully coating opal particles with electrically conducting polyaniline (PANi) polymers were studied. Two different routes were proven successful. First was the in situ chemical doping reaction of PANi with dodecylbenzenesulfonic acid (DBSA) and camphorsulfonic acid dopants. The other method was placement of opal particles in a low concentration of a conducting PANi/DBSA solution in chloroform. Ultraviolet analyses of opal samples showed typical spectra for doped PANi with delocalized polarons. The electrical resistance of coated opal was measured to be 0.75 x 10(3) Omega. Morphological studies of the fractured surface by scanning electron microscopy indicated successful coating. Cyclic voltammetry studies confirmed the percolating behavior of infiltrated PANi. Also, a selective electroactive behavior toward the type of dopant was observed. (C) 2002 Wiley Periodicals, Inc. C1 Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. Polytech Univ, Dept Chem Mat, Brooklyn, NY 11201 USA. RP Khalil, HSA (reprint author), Natl Res Ctr, Dept Polymer Sci, Cairo, Egypt. RI Levon, Kalle/H-7990-2016 OI Levon, Kalle/0000-0001-6833-6254 NR 26 TC 1 Z9 1 U1 0 U2 3 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD OCT 17 PY 2002 VL 86 IS 3 BP 788 EP 793 DI 10.1002/app.11143 PG 6 WC Polymer Science SC Polymer Science GA 584EZ UT WOS:000177455400032 ER PT J AU Vollmer, JM Kandalam, AK Curtiss, LA AF Vollmer, JM Kandalam, AK Curtiss, LA TI Lithium-benzene sandwich compounds: A quantum chemical study SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AB-INITIO; GAS-PHASE; ORGANOMETALLIC CLUSTERS; IONIZATION ENERGIES; MOLLER-PLESSET; COMPLEXES; BINDING; CATIONS; SCALE; LI+ AB The structures and dissociation energies of Li-n.(C6H6)(n+1) sandwich complexes (n = 1-6) have been investigated using quantum chemical techniques. At the G3(MP2) level of theory, the Li.(C6H6)(2) complex exhibits a JahnTeller distortion, forming a D-2h charge-separated species [C6H6-1/2-Li+-C6H6-1/2] with a surprisingly large dissociation energy of 0.85 eV, and a short benzene-benzene distance of 3.54 Angstrom. Comparisons are made with the Li.C6H6, Li+.C6H6, and Li+.(C6H6)(2) complexes. The larger (n > 1) complexes were studied at the B3LYP/6-31G(d) level and were also found to have large dissociation energies, ca. 0.85 eV per Li atom, and short benzene-benzene distances (3.70 Angstrom). C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Kandalam, Anil/M-9590-2014 NR 26 TC 35 Z9 36 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 17 PY 2002 VL 106 IS 41 BP 9533 EP 9537 DI 10.1021/jp020822d PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 603FQ UT WOS:000178548500024 ER PT J AU Koput, J Peterson, KA AF Koput, J Peterson, KA TI Ab initio potential energy surface and vibrational-rotational energy levels of X-2 Sigma(+) CaOH SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID OPTICAL DOUBLE-RESONANCE; LASER SPECTROSCOPY; ALKALINE-EARTH; FERMI RESONANCE; RENNER-TELLER; SPIN-ORBIT; STATE; MOLECULES; MONOHYDROXIDES; DEPERTURBATION AB The equilibrium structure and potential energy surface of calcium monohydroxide in its ground doublet state, X(2)Sigma(+) CaOH, have been determined from large-scale ab initio calculations using the spin-restricted coupled-cluster method, RCCSD(T), with basis sets of quadruple- and quintuple-zeta quality. The vibrational-rotational energy levels of the CaOH and CaOD isotopomers were calculated using the variational method. The spectroscopic constants determined are found to be in remarkably good agreement with experimental data. C1 Adam Mickiewicz Univ Poznan, Dept Chem, PL-60780 Poznan, Poland. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Dept Chem, Richland, WA 99352 USA. RP Koput, J (reprint author), Adam Mickiewicz Univ Poznan, Dept Chem, PL-60780 Poznan, Poland. NR 39 TC 122 Z9 122 U1 3 U2 25 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 OCT 17 PY 2002 VL 106 IS 41 BP 9595 EP 9599 DI 10.1021/jp026283u PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 603FQ UT WOS:000178548500033 ER PT J AU Rajh, T Chen, LX Lukas, K Liu, T Thurnauer, MC Tiede, DM AF Rajh, T Chen, LX Lukas, K Liu, T Thurnauer, MC Tiede, DM TI Surface restructuring of nanoparticles: An efficient route for ligand-metal oxide crosstalk SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRON-SPIN-RESONANCE; SEMICONDUCTOR PARTICLES; NANOCRYSTALLINE TIO2; CHARGE SEPARATION; SENSITIZING DYE; QUANTUM DOTS; ENERGY-CONVERSION; SIZE QUANTIZATION; TITANIUM-DIOXIDE; COLLOIDAL TIO2 AB Surface modification of nanocrystalline, metal oxide particles with enediol ligands was found to result in altered optical properties of nanoparticles. The surface modification results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites. The optical shift is correlated to the dipole moment of the Ti-ligand complexes at the particle surface and decreases with the ligand size. The binding was found to be exclusively characteristic of colloids in the nanocrystalline domain(<20 nm). X-ray near-edge structure measurements at Ti K edge indicate that in this size domain the surface Ti atoms adjust,their coordination environment to form undercoordinated sites. These five-coordinated defect sites are the source of novel enhanced and selective reactivity of the nanoparticle toward bidentate ligand binding as observed using IR spectroscopy. Enediol ligands have the optimal geometry for chelating surface Ti atoms, resulting in a five-membered ring coordination complex and restored six-coordinated octahedral geometry of surface Ti atoms. The binding of enediol ligands is enhanced because of the stability gained from adsorption-induced restructuring of the nanoparticle surface. Consistent behavior was found, for the three different nanocrystalline metal oxide systems: TiO2, Fe2O3, and ZrO2. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Rajh, T (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 58 TC 439 Z9 442 U1 20 U2 176 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 OCT 17 PY 2002 VL 106 IS 41 BP 10543 EP 10552 DI 10.1021/jp021235v PG 10 WC Chemistry, Physical SC Chemistry GA 603FR UT WOS:000178548600006 ER PT J AU Merkulov, VI Hensley, DK Melechko, AV Guillorn, MA Lowndes, DH Simpson, ML AF Merkulov, VI Hensley, DK Melechko, AV Guillorn, MA Lowndes, DH Simpson, ML TI Control mechanisms for the growth of isolated vertically aligned carbon nanofibers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; PATTERNED GROWTH; NANOTUBES; ALIGNMENT AB Isolated vertically aligned carbon nanofibers (VACNFs) have been grown using do plasma-enhanced chemical vapor deposition, and the effects of the growth conditions on VACNF morphology and composition have been determined in substantial detail. The dependence of the growth rate, tip and base diameters, and chemical composition, of isolated VACNFs on the growth parameters is described, including the effects of plasma power and gas mixture. Phenomenological models explaining the observed growth behavior are presented. The results indicate the importance of plasma control for the deterministic growth of isolated VACNFs, which are promising elements for the fabrication of practical nanoscale devices. C1 Oak Ridge Natl Lab, Mol Scale Engn & Nanoscale Technol Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Thin Film & Nanostruct Mat Phys Grp, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. RP Merkulov, VI (reprint author), Oak Ridge Natl Lab, Mol Scale Engn & Nanoscale Technol Grp, Oak Ridge, TN 37831 USA. RI Melechko, Anatoli/B-8820-2008; Simpson, Michael/A-8410-2011; Hensley, Dale/A-6282-2016 OI Simpson, Michael/0000-0002-3933-3457; Hensley, Dale/0000-0001-8763-7765 NR 23 TC 64 Z9 64 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 OCT 17 PY 2002 VL 106 IS 41 BP 10570 EP 10577 DI 10.1021/jp025647f PG 8 WC Chemistry, Physical SC Chemistry GA 603FR UT WOS:000178548600009 ER PT J AU Brand, HV Rabie, RL Funk, DJ Diaz-Acosta, I Pulay, P Lippert, TK AF Brand, HV Rabie, RL Funk, DJ Diaz-Acosta, I Pulay, P Lippert, TK TI Theoretical and experimental study of the vibrational spectra of the alpha, beta, and delta phases of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; HOT-SPOT FORMATION; FORCE-FIELDS; DECOMPOSITION; STATE; BOND AB The vibrational spectra of the alpha, beta, and delta phases of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) have been investigated by complimentary theoretical and experimental approaches. Density functional theory and the scaled quantum mechanical force-field method have been used to calculate the vibrational spectra of the H8C4N8O8 molecule in C-i and C-2v symmetry conformations in the gas phase. By comparing the calculated molecular vibrational frequencies of the H8C4N8O8 molecule with the experimental infrared and Raman spectra of HMX crystalline samples, we attempt to assign the intramolecular motions that correspond to the measured bands in the experimental spectra of HMX in alpha-, beta-, and delta-phase crystal lattices. Our analysis of the vibrational spectra verifies that the particular conformation of the H8C4N8O8 molecule in each crystal lattice of HMX determines, to a great extent, the general pattern of the vibrational spectrum of the crystal lattice. We also compare our detailed motion assignments with the general assignments proposed in previous experimental work. Good agreement is found between the calculated geometry of the H8C4N8O8 molecule in the Ci symmetry conformation and the experimental geometry of molecules in the beta-phase lattice of HMX and between the calculated geometry of the H8C4N8O8 molecule in the C-2v symmetry conformation and the experimental geometry of molecules in the alpha- and delta-phase lattices of HMX. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Dynam Experimentat Div, Los Alamos, NM 87545 USA. Univ Arkansas, Dept Chem & Biochem, Fayetteville, AR 72701 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. RP Brand, HV (reprint author), Los Alamos Natl Lab, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. RI Lippert, Thomas/N-2423-2016 NR 27 TC 52 Z9 53 U1 0 U2 11 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 OCT 17 PY 2002 VL 106 IS 41 BP 10594 EP 10604 DI 10.1021/jp020909z PG 11 WC Chemistry, Physical SC Chemistry GA 603FR UT WOS:000178548600012 ER PT J AU Janssens, RVF Fornal, B Mantica, PF Brown, BA Broda, R Bhattacharyya, P Carpenter, MP Cinausero, M Daly, PJ Davies, AD Glasmacher, T Grabowski, ZW Groh, DE Honma, M Kondev, FG Krolas, W Lauritsen, T Liddick, SN Lunardi, S Marginean, N Mizusaki, T Morrissey, DJ Morton, AC Mueller, WF Otsuka, T Pawlat, T Seweryniak, D Schatz, H Stolz, A Tabor, SL Ur, CA Viesti, G Wiedenhover, I Wrzesinski, J AF Janssens, RVF Fornal, B Mantica, PF Brown, BA Broda, R Bhattacharyya, P Carpenter, MP Cinausero, M Daly, PJ Davies, AD Glasmacher, T Grabowski, ZW Groh, DE Honma, M Kondev, FG Krolas, W Lauritsen, T Liddick, SN Lunardi, S Marginean, N Mizusaki, T Morrissey, DJ Morton, AC Mueller, WF Otsuka, T Pawlat, T Seweryniak, D Schatz, H Stolz, A Tabor, SL Ur, CA Viesti, G Wiedenhover, I Wrzesinski, J TI Structure of Ti-52,Ti-54 and shell closures in neutron-rich nuclei above Ca-48 SO PHYSICS LETTERS B LA English DT Article ID BEAMS AB The level structure of Ti-54(22)32 has been explored for the first time by combining P-decay measurements from fragmentation 22 products with prompt gamma-ray spectroscopy following deep inelastic reactions. The latter technique was also instrumental in tracing Ti-52(30) to higher spin. The data provide new tests of effective interactions for full pf-shell calculations in neutron-rich nuclei above Ca-48. The data indicate the presence of a significant subshell gap at N = 32 and comparisons between theory and experiment suggest an additional shell closure at N = 34 in Ca and Ti isotopes.. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Michigan State Univ, Natl Supercond Cyclotron Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. Univ Aizu, Ctr Math Sci, Fukushima 9658580, Japan. Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Senshu Univ, Inst Nat Sci, Kawasaki, Kanagawa 2148580, Japan. RIKEN, Wako, Saitama 3510198, Japan. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. RP Janssens, RVF (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Glasmacher, Thomas/C-4462-2008; Krolas, Wojciech/N-9391-2013; Glasmacher, Thomas/H-9673-2014; Cinausero, Marco/K-2752-2014; OTSUKA, TAKAHARU/G-5072-2014; Carpenter, Michael/E-4287-2015; Morton, Colin/K-1561-2015; Marginean, Nicolae Marius/C-4732-2011 OI Glasmacher, Thomas/0000-0001-9436-2448; Carpenter, Michael/0000-0002-3237-5734; Morton, Colin/0000-0003-0214-7551; NR 26 TC 139 Z9 140 U1 0 U2 10 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 OCT 17 PY 2002 VL 546 IS 1-2 BP 55 EP 62 AR PII S0370-2693(02)02682-5 DI 10.1016/S0370-2693(02)02682-5 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 609UR UT WOS:000178923400007 ER PT J AU Grigsby, JJ Blanch, HW Prausnitz, JM AF Grigsby, JJ Blanch, HW Prausnitz, JM TI Effect of secondary structure on the potential of mean force for poly-L-lysine in the alpha-helix and beta-sheet conformations SO BIOPHYSICAL CHEMISTRY LA English DT Article DE poly-L-lysine; potential of mean force; alpha helix; beta sheet; specific interactions ID PROTEIN; DISEASE; MIXTURES AB Because poly-L-lysine (PLL) can exist in the alpha-helix or beta-sheet conformation depending on solution preparation and solution conditions, PLL is a suitable candidate to probe the dependence of protein interactions on secondary structure. The osmotic second virial coefficient and weight-average molecular weight are reported from low-angle laser-light scattering measurements for PLL as a function of NaCl concentration, pH, and alpha-helix or beta-sheet content. Interactions between PLL molecules become more attractive as salt concentration increases due to screening of PLL charge by salt ions and at low salt concentration become more attractive as pH increases due to decreased net charge on PLL. The experimental results show that interactions are stronger for the beta-sheet conformation than for the alpha-helix conformation. A spherically-symmetric model for the potential of mean force is used to account for specific interactions not described by DLVO theory and to show how differences in secondary structure affect PLL interactions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Blanch, HW (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 25 TC 26 Z9 26 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD OCT 16 PY 2002 VL 99 IS 2 BP 107 EP 116 AR PII S0301-4622(02)00138-2 DI 10.1016/S0301-4622(02)00138-2 PG 10 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA 605TN UT WOS:000178693300001 PM 12377362 ER PT J AU Klei, SR Golden, JT Burger, P Bergman, RG AF Klei, SR Golden, JT Burger, P Bergman, RG TI Cationic Ir(III) alkyl and hydride complexes: stoichiometric and catalytic C-H activation by Cp*(PMe3)Ir(R)(X) in homogeneous solution SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE C-H activation; cationic Ir(III) complexes; H-D exchange; lr(V) complexes; methyl abstraction ID HYDROGEN BOND ACTIVATION; DENSITY-FUNCTIONAL THEORY; TRANSITION-METAL; OXIDATIVE ADDITION; HYDROCARBON ACTIVATION; PLATINUM(II) COMPLEXES; REDUCTIVE ELIMINATION; CARBENE COMPLEXES; CARBON-MONOXIDE; IRIDIUM AB This report details our work in the area of C-H activation by cationic Ir(III) complexes. We highlight the previously reported chemistry of transition metal complexes of the type Cp-*(PMe3)Ir(R)(X) (Cp-* is pentamethylcyclopentadienyl or eta(5) -C5Me5; R = alkyl, hydrido; X = OSO2CF3, B(3,5-(CF3)(2)C6H3)(4))), and disclose new results concerning the production of these complexes using Lewis acids (LAs). Additionally, new work aimed at examining the mechanism of C-H activation by these complexes is presented. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, CNDOS, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ctr New Direct Organ Synth, CNDOS, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Bergman, RG (reprint author), Univ Calif Berkeley, Dept Chem, CNDOS, Berkeley, CA 94720 USA. NR 65 TC 55 Z9 55 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD OCT 16 PY 2002 VL 189 IS 1 BP 79 EP 94 AR PII S1381-1169(02)00192-9 DI 10.1016/S1381-1169(02)00192-9 PG 16 WC Chemistry, Physical SC Chemistry GA 642ZA UT WOS:000180836200008 ER PT J AU Dreuw, A Dunietz, BD Head-Gordon, M AF Dreuw, A Dunietz, BD Head-Gordon, M TI Characterization of the relevant excited states in the photodissociation of CO-ligated hemoglobin and myoglobin SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DENSITY-FUNCTIONAL THEORY; CARBON-MONOXIDE BINDING; ELECTRONIC-STRUCTURE; FE-57 MOSSBAUER; SINGLE-CRYSTAL; HEME-PROTEINS; MODEL; RECOMBINATION; MUTANTS C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Head-Gordon, M (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 23 TC 68 Z9 68 U1 1 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 OCT 16 PY 2002 VL 124 IS 41 BP 12070 EP 12071 DI 10.1021/ja026916i PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 602PY UT WOS:000178514700006 PM 12371827 ER PT J AU Barnes, JH Sperline, R Denton, MB Barinaga, CJ Koppenaal, D Young, ET Hieftje, GM AF Barnes, JH Sperline, R Denton, MB Barinaga, CJ Koppenaal, D Young, ET Hieftje, GM TI Characterization of a focal plane camera fitted to a Mattauch-Herzog geometry mass spectrograph. 1. Use with a glow-discharge source SO ANALYTICAL CHEMISTRY LA English DT Article ID SPECTROMETRY AB A Mattauch-Herzog geometry mass spectrograph (MHMS) has been equipped with a novel array detector, the focal plane camera (FPC). The FPC consists of an array of gold Faraday cups, each coupled to its own integrator, with interrogation of the integrators performed by a multiplexer. The initial coupling of this instrument with a pin-type glow discharge source has provided limits of detection in the single to hundreds of nanograms per gram regime; isotope ratio accuracy and precision better than 5% error and 0.2% RSD, respectively; and a linear dynamic range of at least 6 orders of magnitude. A current weakness of the FPC is its pixel size, which limits both sensitivity and baseline resolution (to R =. 130). The minimum data acquisition time for multiple images at present is 1 ms/image, with a dead time of 3.2 ms between images, which will limit the ability of the FPC to monitor extremely short transient signals. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Hieftje, GM (reprint author), Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. NR 27 TC 41 Z9 42 U1 0 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 OCT 15 PY 2002 VL 74 IS 20 BP 5327 EP 5332 DI 10.1021/ac020304z PG 6 WC Chemistry, Analytical SC Chemistry GA 604UP UT WOS:000178639700023 PM 12403588 ER PT J AU Christodoulou, M Yeung, ES AF Christodoulou, M Yeung, ES TI Chemical imaging of surface reactions by multiplexed capillary electrophoresis SO ANALYTICAL CHEMISTRY LA English DT Article ID HETEROGENEOUS CATALYSTS; COMBINATORIAL LIBRARIES; DISCOVERY AB A new technique for in situ imaging of surface reactions and screening heterogeneous catalysts by using multiplexed capillary electrophoresis was developed. By bundling together the inlets of a large number of capillaries, an aligned imaging probe can be created that can be used to sample directly products formed at a surface with spatial resolution determined by the outer diameter of the capillaries. In this work, we used surfaces made of platinum, iron, or gold wires to generate electrochemical products for imaging. Various shapes were recorded including crosses, squares, and triangles. A model multifunctional catalytic surface consisting of both iron and platinum electrodes in the shape of a cross was also imaged successfully. Each of the two wires produced a different electrochemical product that could be subjected to capillary electrophoresis to provide chemical selectivity. On the basis of the collected data, we were able to distinguish the products from each wire in the reconstructed image. 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 19 TC 0 Z9 0 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 OCT 15 PY 2002 VL 74 IS 20 BP 5414 EP 5419 DI 10.1021/ac025894f PG 6 WC Chemistry, Analytical SC Chemistry GA 604UP UT WOS:000178639700036 PM 12403601 ER PT J AU Tang, KQ Tolmachev, AV Nikolaev, E Zhang, R Belov, ME Udseth, HR Smith, RD AF Tang, KQ Tolmachev, AV Nikolaev, E Zhang, R Belov, ME Udseth, HR Smith, RD TI Independent control of ion transmission in a jet disrupter dual-channel ion funnel electrospray ionization MS interface SO ANALYTICAL CHEMISTRY LA English DT Article ID TRANSFORM MASS-SPECTROMETRY; ATMOSPHERIC-PRESSURE; MULTICAPILLARY INLET; HIGH-THROUGHPUT; ACCURACY AB A new atmospheric pressure ionization mass spectrometer (API-MS) interface has been developed to allow the control of ion transmission through the first vacuum stage of the mass spectrometer. The described interface uses a dual-heated capillary and a dual-inlet ion funnel design. Two electrosprays, aligned with the dual-capillary inlet, are used to introduce ions from different solutions independently into the MS. The initial design was specifically aimed at developing a method for the controlled introduction of calibrant ions in highly accurate mass measurements using Fourier transform ion cyclotron resonance mass spectrometer (FTICR). The dual-channel ion funnel has different inlet diameters that are aligned with the dual capillaries. The large diameter main channel of the ion funnel is used for analyte introduction to provide optimum ion transmission. The second, smaller diameter channel inlet includes a jet disrupter in the ion funnel to modulate the ion transmission through the channel. The two inlet channels converge into a single-channel ion funnel where ions from both channels are mixed, focused, and transmitted to the mass analyzer. Both theoretical simulations and experimental results show that the transmission of different m/z species in the small diameter channel of the ion funnel can be effectively modulated by varying the bias voltage on the jet disrupter. Both static and dynamic modulations of ion transmission are demonstrated experimentally by applying either a constant DC or a square waveform voltage to the jet disrupter. High ion transmission efficiency, similar to the standard single-channel ion funnel, is maintained in the main analyte channel inlet of the ion funnel over a broad m/z range with negligible "cross talk" between the two ion funnel inlet channels. Several possible applications of the new interface (e.g., for high-accuracy MS analysis of complex biological samples) are described. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. EM rd-smith@pnl.gov RI Smith, Richard/J-3664-2012; Nikolaev, Eugene/N-4498-2013 OI Smith, Richard/0000-0002-2381-2349; Nikolaev, Eugene/0000-0001-6209-2068 FU NCI NIH HHS [CA93306] NR 20 TC 46 Z9 47 U1 2 U2 33 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 EI 1520-6882 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 2002 VL 74 IS 20 BP 5431 EP 5437 DI 10.1021/ac0202583 PG 7 WC Chemistry, Analytical SC Chemistry GA 604UP UT WOS:000178639700039 PM 12403604 ER PT J AU Ewan, KB Henshall-Powell, RL Ravani, SA Pajares, MJ Arteaga, C Warters, R Akhurst, RJ Barcellos-Hoff, MH AF Ewan, KB Henshall-Powell, RL Ravani, SA Pajares, MJ Arteaga, C Warters, R Akhurst, RJ Barcellos-Hoff, MH TI Transforming growth factor-beta 1 mediates cellular response to DNA damage in situ SO CANCER RESEARCH LA English DT Article ID BREAST-CARCINOMA CELLS; FACTOR-BETA; TUMOR-SUPPRESSOR; CANCER-THERAPY; P53; ACTIVATION; GROWTH-FACTOR-BETA-1; APOPTOSIS; PROGRESSION; RADIATION AB Transforming growth factor (TGF)-beta1 is rapidly activated after ionizing radiation, but its specific role in cellular responses to DNA damage is not known. Here we use Tgfbeta1 knockout mice to show that radiation-induced apoptotic response is TGF-beta1 dependent in the mammary epithelium, and that both apoptosis and inhibition of proliferation in response to DNA damage decrease as a function of TGF-beta1 gene dose in embryonic epithelial tissues. Because apoptosis in these tissues has been shown previously to be p53 dependent, we then examined p53 protein activation. TGF-beta1 depletion, by either gene knockout or by using TGF-beta neutralizing antibodies, resulted in decreased p53 Ser-18 phosphorylation in irradiated mammary gland. These data indicate that TGF-beta1 is essential for rapid p53-mediated cellular responses that mediate cell fate decisions in situ. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Vanderbilt Univ, Div Med Oncol, Nashville, TN 37235 USA. Univ Utah, Med Ctr, Dept Radiol, Salt Lake City, UT 84112 USA. Univ Calif San Francisco, Mt Zion Canc Res Inst, San Francisco, CA 94143 USA. RP Barcellos-Hoff, MH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Bldg 74-174,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Ewan, Kenneth/N-3554-2015 OI Ewan, Kenneth/0000-0001-6622-9009 FU NCI NIH HHS [R01 CA62212] NR 27 TC 105 Z9 114 U1 0 U2 1 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD OCT 15 PY 2002 VL 62 IS 20 BP 5627 EP 5631 PG 5 WC Oncology SC Oncology GA 605TP UT WOS:000178693400002 PM 12384514 ER PT J AU DeWitt, A Iida, T Lam, HY Hill, V Wiley, HS Lauffenburger, DA AF DeWitt, A Iida, T Lam, HY Hill, V Wiley, HS Lauffenburger, DA TI Affinity regulates spatial range of EGF receptor autocrine ligand binding SO DEVELOPMENTAL BIOLOGY LA English DT Article ID EPIDERMAL GROWTH-FACTOR; MOUSE MAMMARY-GLAND; SECRETED PROTEIN ARGOS; FACTOR-ALPHA; CAENORHABDITIS-ELEGANS; FACTOR FAMILY; HEPATOCELLULAR-CARCINOMA; MORPHOGEN GRADIENTS; HEPARIN-BINDING; DROSOPHILA EYE AB Proper spatial localization of EGFR signaling activated by autocrine ligands represents a critical factor in embryonic development as well as tissue organization and function, and ligand/receptor binding affinity is among the molecular and cellular properties suggested to play a role in governing this localization. We employ a computational model to predict how receptor-binding affinity affects local capture of autocrine ligand vis-a-vis escape to distal regions, and provide experimental test by constructing cell lines expressing EGFR along with either wild-type EGF or a low-affinity mutant, EGF(L47M). The model predicts local capture of a lower affinity autocrine ligand to be less efficient when the ligand production rate is small relative to receptor appearance rate. Our experimental data confirm this prediction, demonstrating that cells can use ligand/receptor binding affinity to regulate ligand spatial distribution when autocrine ligand production is limiting for receptor signaling. (C) 2002 Elsevier Science (USA). C1 MIT, Dept Chem Engn, Cambridge, MA 02139 USA. MIT, Dept Biol, Biol Engn Div, Cambridge, MA 02139 USA. MIT, Ctr Canc Res, Cambridge, MA 02139 USA. Univ Utah, Sch Med, Dept Pathol, Div Cell Biol & Immunol, Salt Lake City, UT USA. Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Lauffenburger, DA (reprint author), MIT, Dept Chem Engn, Cambridge, MA 02139 USA. OI Wiley, Steven/0000-0003-0232-6867 FU NICHD NIH HHS [HD28528]; NIGMS NIH HHS [GM62575] NR 61 TC 29 Z9 29 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0012-1606 J9 DEV BIOL JI Dev. Biol. PD OCT 15 PY 2002 VL 250 IS 2 BP 305 EP 316 DI 10.1006/dbio.2002.0807 PG 12 WC Developmental Biology SC Developmental Biology GA 605KZ UT WOS:000178678200006 PM 12376105 ER PT J AU Chien, A Foster, I Goddette, D AF Chien, A Foster, I Goddette, D TI Grid technologies empowering drug discovery SO DRUG DISCOVERY TODAY LA English DT Review AB Grid technologies enable flexible coupling and sharing of computers, instruments and storage. Grids can provide technical solutions to the volume of data and computational demands associated with drug discovery by delivering larger computing capability (flexible resource sharing), providing coordinated access to large data resources and enabling novel online exploration (coupling computing, data and instruments online). Here, we illustrate this potential by describing two applications: the use of desktop PC grid technologies for virtual screening, and distributed X-ray structure reconstruction and online visualization. C1 Entropia, San Diego, CA 92121 USA. Univ Calif San Diego, Dept Comp Sci & Engn, San Diego, CA 92039 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. RP Chien, A (reprint author), Entropia, 10145 Pacific Hts,Suite 800, San Diego, CA 92121 USA. RI Foster, Ian/A-1357-2007 OI Foster, Ian/0000-0003-2129-5269 NR 29 TC 12 Z9 13 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-6446 J9 DRUG DISCOV TODAY JI Drug Discov. Today PD OCT 15 PY 2002 VL 7 IS 20 SU S BP S176 EP S180 AR PII S1359-6446(02)02369-3 DI 10.1016/S1359-6446(02)02369-3 PG 5 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 605WT UT WOS:000178700600005 PM 12546902 ER PT J AU King, SD Lowman, JP Gable, CW AF King, SD Lowman, JP Gable, CW TI Episodic tectonic plate reorganizations driven by mantle convection SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE mantle; convection; plate tectonics; movement; Emperor Seamounts ID SPHERICAL-SHELL MODELS; CONTINENTAL COLLISIONS; DEPENDENT VISCOSITY; THERMAL-CONVECTION; DRIVING FORCES; SURFACE PLATES; GENERATION; NUMBER; FLOW; MOTION AB Periods of relatively uniform plate motion were interrupted several times throughout the Cenozoic and Mesozoic by rapid plate reorganization events [R. Hey, Geol. Soc. Am. Bull. 88 (1977) 1404-1420; P.A. Rona, E.S. Richardson, Earth Planet. Sci. Lett. 40 (1978) 1-11; D.C. Engebretson, A. Cox, R.G. Gordon, Geol. Soc. Am. Spec. Pap. 206 (1985); R.G. Gordon, D.M. Jurdy, J. Geophys. Res. 91 (1986) 12389-12406; D.A. Clague, G.B. Dalrymple, US Geol. Surv. Prof. Pap. 1350 (1987) 5-54; J.M. Stock, P. Molnar, Nature 325 (1987) 495-499; C. Lithgow-Bertelloni, M.A. Richards, Geophys. Res. Lett. 22 (1995) 1317-1320; MA, Richards, C. Lithgow-Bertelloni, Earth Planet. Sci. Lett. 137 (1996) 19-27; C. Lithgow-Bertelloni, M.A. Richards, Rev. Geophys. 36 (1998) 27-78]. It has been proposed that changes in plate boundary forces are responsible for these events [M.A. Richards, C. Lithgow-Bertelloni, Earth Planet. Sci. Lett. 137 (1996) 19-27; C. Lithgow-Bertelloni, M.A. Richards, Rev. Geophys. 36 (1998) 27-78]. We present an alternative hypothesis: convection-driven plate motions are intrinsically unstable due to a buoyant instability that develops as a result of the influence of plates on an internally heated mantle. This instability, which has not been described before, is responsible for episodic reorganizations of plate motion. Numerical mantle convection experiments demonstrate that high-Rayleigh number convection with internal heating and surface plates is sufficient to induce plate reorganization events, changes in plate boundary forces, or plate geometry, are not required. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Univ Leeds, Sch Earth Sci, Leeds LS2 9JT, W Yorkshire, England. Los Alamos Natl Lab, Hydrol Geochem & Geol EES6, Los Alamos, NM 87545 USA. RP King, SD (reprint author), Purdue Univ, Dept Earth & Atmospher Sci, 1397 CIVL, W Lafayette, IN 47907 USA. RI King, Scott/B-1220-2008; Gable, Carl/B-4689-2011; OI King, Scott/0000-0002-9564-5164; Gable, Carl/0000-0001-7063-0815 NR 43 TC 47 Z9 47 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT 15 PY 2002 VL 203 IS 1 BP 83 EP 91 AR PII S0012-821X(02)00852-X DI 10.1016/S0012-821X(02)00852-X PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 612MA UT WOS:000179078800007 ER PT J AU Scott, HP Williams, Q Ryerson, FJ AF Scott, HP Williams, Q Ryerson, FJ TI Experimental constraints on the chemical evolution of large icy satellites SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Ganymede satellite; Callisto; icy satellites; hydrothermal; astrobiology ID OPTIMIZED STANDARD STATE; INTERNAL STRUCTURE; THERMAL EVOLUTION; SOLAR-SYSTEM; GANYMEDE; MINERALS; EUROPA; CALLISTO; SURFACE; ORGANICS AB We derive experimental constraints on the interior structure and mineralogy of large icy satellites by reacting material of chondritic chemistry with water at a pressure of 1.5 GPa, temperatures between 300degreesC and 800degreesC and a range of oxygen fugacities. Our results document the existence of three chemical processes that probably occur in large icy satellites as a result of high pressure hydrothermal processing: (1) the formation of low-density hydrated silicates, (2) the alloying of iron and sulfur to form FeS-dominated cores, and (3) the instability of organic material relative to carbonates. We construct new internal models of the thermal and structural state of Ganymede, and infer that the magnetic field of this body arises from convection within a mostly iron sulfide core. Simple thermochemical calculations are conducted to further explore the likely effects of composition and oxygen fugacity on the high pressure chemistry undergone by organic material within icy satellites. Both experimental and calculated results show that primordial organics are likely to have been largely oxidized to carbonates through hydrothermal processing early in Ganymede's history, potentially sterilizing Ganymede's H2O layer. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Sci, Livermore, CA 94550 USA. RP Scott, HP (reprint author), Carnegie Inst Washington, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. NR 47 TC 34 Z9 37 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT 15 PY 2002 VL 203 IS 1 BP 399 EP 412 AR PII S0012-821X(02)00850-6 DI 10.1016/S0012-821X(02)00850-6 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 612MA UT WOS:000179078800030 ER PT J AU Wang, RL Scarpitta, SC Zhang, SC Zheng, MP AF Wang, RL Scarpitta, SC Zhang, SC Zheng, MP TI Later Pleistocene/Holocene climate conditions of Qinghai-Xizhang Plateau (Tibet) based on carbon and oxygen stable isotopes of Zabuye Lake sediments SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE stable isotopes; C-13/C-12; O-18/O-16; Pleistocene; Holocene; paleoclimatology; lakes; Xizang China ID BASIN WESTERN TIBET; ICE-CORE; RECORD; TEMPERATURE; TRANSITION; RATIOS; PCO(2); PAST AB We present a time series of carbon and oxygen stable isotope records of the last 30000 C-14 years throughout the last glacial-postglacial cycle from western Qinghai-Xizhang (Tibet) Plateau. A 20-m core drilled in the south basin of Zabuye Salt Lake was analyzed for inorganic and organic carbon and total sulfur contents, delta(13)C and delta(18)O values of carbonates. Our results indicate that climatic changes have led to a drastic negative shift of stable isotope ratios at the transition between the Last Full Glacial and the postglacial phase during Later Pleistocene times (similar to16.2 kyr BP), and a rapid positive shift at the transition from Pleistocene to Holocene (similar to10.6 kyr BP). The first shift is marked by the drop of delta(18)O(carb) values of about 10parts per thousand (from +2 to -8parts per thousand) and delta(13)C(carb) values of about 3parts per thousand (from 5 to 2parts per thousand). The second shift which occurred at the transition from Pleistocene to Holocene was of similar magnitude but in the opposite direction. Isotope data, combined with total organic and inorganic carbon contents and the lithological composition of the core, suggest this lake was an alluvial pre-lake environment prior to ca. 28 C-14 kyr BP. During ca. 28-16.2 C-14 kyr BP, Zabuye Lake was likely a moderately deep lake with limited outflow. The cool and and glacial climate led the lake level to drop drastically. Extended residence time overwhelmed the lower temperature and caused a steady increase of delta(13)C(carb) and delta(18)C(carb) values and total inorganic carbon content in the sediments. During ca. 16.2-10.6 C-14 kyr BP, this lake probably overflowed and received abundant recharge from melting glaciers when the deglaciation was in its full speed. A spike of markedly enhanced delta(13)C(carb) and delta(18)O(carb) is seen at similar to11.5 kyr BP, probably due to the isotopic effects left behind by the short but severe Younger Dryas (YD) event. After ca. 10.6 C-14 kyr BP, Zabuye Lake probably closed its surface outflow, due to strong desiccation and drastic climate warming. The Early and Middle Holocene were characterized by unstable climatic conditions with alternating warmer/cooler episodes as indicated by the severe fluctuations of total organic carbon, delta(13)C and delta(18)O values. A hypersaline salt lake environment was finally formed at Zabuye after similar to5 C-14 kyr BP when the mirabilite and halite concentrations steadily increased and became the dominant minerals in the sediments. Severe imbalance of inflow/outflow resulted in the drastic increase of total sulfur, delta(13)C(carb) and delta(18)O(carb) values and dominance of halite in the lake since ca. 3.8 kyr BP to present. Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Analyt Chem Lab, ASL RCD, Upton, NY 11973 USA. China Natl Petr Co, Key Lab Petr Geochem, Beijing 100083, Peoples R China. Chinese Acad Geol Sci, Res & Dev Ctr Saline Lake & Epithermal Deposits, Beijing 100037, Peoples R China. RP Wang, RL (reprint author), Brookhaven Natl Lab, Analyt Chem Lab, ASL RCD, Bldg 703, Upton, NY 11973 USA. NR 41 TC 91 Z9 115 U1 2 U2 27 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT 15 PY 2002 VL 203 IS 1 BP 461 EP 477 AR PII S0012-821X(02)00829-4 DI 10.1016/S0012-821X(02)00829-4 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 612MA UT WOS:000179078800034 ER PT J AU Buzorius, G Zelenyuk, A Brechtel, F Imre, D AF Buzorius, G Zelenyuk, A Brechtel, F Imre, D TI Simultaneous determination of individual ambient particle size, hygroscopicity and composition SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GROWTH; AEROSOL; TDMA AB [1] A new system for simultaneous determination of individual particle size, hygroscopicity, and composition of internally and externally mixed aerosols is presented. An HTDMA is used to select particles according to their size and hygroscopicity for compositional analysis by a single particle mass spectrometer. The capability of the system is demonstrated on a laboratory generated aerosol consisting of polystyrene latex spheres coated with a layer of ammonium nitrate to represent an internally mixed aerosol with controllable hygroscopicity that is externally mixed with pure ammonium nitrate particles. Results are presented from an ambient study illustrating the sensitivity of the system and the capability to provide detailed information on individual atmospheric particles within a short sampling time. C1 Brookhaven Natl Lab, Dept Environm Sci, Div Atmospher Sci, Upton, NY 11973 USA. RP Buzorius, G (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Div Atmospher Sci, Upton, NY 11973 USA. NR 8 TC 41 Z9 42 U1 3 U2 18 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 OCT 15 PY 2002 VL 29 IS 20 AR 1974 DI 10.1029/2001GL014221 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 639BL UT WOS:000180607700035 ER PT J AU Jackson, GP Gibson, JK Duckworth, DC AF Jackson, GP Gibson, JK Duckworth, DC TI Gas-phase reactions of bare and oxo-ligated actinide and lanthanide cations with pentamethylcyclopentadiene studied in a quadrupole ion trap mass spectrometer SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE gas-phase metal ion-molecule chemistry; actinide; bath gas effect; quadrupole ion trap; lanthanide ID HYDROCARBON ACTIVATION; IONIZATION-POTENTIALS; REACTIVITY; CHEMISTRY; METAL; PHOTODISSOCIATION; DISSOCIATION; ALKANES AB Reactions of bare and oxo-ligated monopositive ions of uranium and thorium with 1,2,3,4,5-pentamethylcyclopentadiene, C10H16, (HCp*) were examined in a quadrupole ion trap (QIT) mass spectrometer. Representative lanthanide ions, Ln(+) and LnO(+), and tantalum ions, Ta+ and TaO+, were studied for comparison. The product branching ratios for both primary and secondary reactions of the actinide ions demonstrated gas-phase organoactinide chemistry that is quite disparate from organolanthanide chemistry under comparable conditions for this neutral reactant. Particularly revealing were product distributions for ThO+ and UO+, which indicated chemical behavior similar to that of bare Sm+. We conclude that at least one valence electron at the metal center of the actinide oxide ions must remain chemically active. In the case of UO+, this provides evidence for the chemical engagement of the quasi-valence 5f electrons, which is in distinct contrast to the inert character of the 4f electrons of the lanthanides in both Ln(+) and LnO(+). Mass-selective chemistry of two primary products, UC10H10+ and UC9H8+, also showed behavior similar to that of Sm+ and UO+, implying that there are two covalent organouranium bonds in these complex ions. In comparing the QIT results for the lanthanides with those from a low-pressure ion cyclotron resonance (ICR) mass spectrometry study [Organometallics 16 (1997) 3845], qualitative agreement was found, but significant quantitative differences were apparent. Based on results from collision-induced dissociation and effects of variations in bath gas pressure in the QIT, we conclude that the discrepancies arise from the very different pressure regimes in the ICR and QIT. Evidently, the QIT can be operated over a range of pressures that manifest effects of collisional cooling for some reactions. For the lowest pressure QIT experiments, the high degree of fragmentation is reminiscent of the ICR results. We propose that the QIT bath gas can essentially act as an inert "solvent," which serves to mediate high-energy processes due to energy transfer from nascent hot intermediate products via energy-dissipating collisions. (Int J Mass Spectrom 220 (2002) 419-441) (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Gibson, JK (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Jackson, Glen/D-3518-2014; Duckworth, Douglas/B-7171-2015 OI Jackson, Glen/0000-0003-0803-6254; Duckworth, Douglas/0000-0002-8161-5685 NR 50 TC 25 Z9 25 U1 0 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD OCT 15 PY 2002 VL 220 IS 3 BP 419 EP 441 AR PII S1387-3806(02)00839-4 DI 10.1016/S1387-3806(02)00839-4 PG 23 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 599MG UT WOS:000178338100005 ER PT J AU Ritchie, B Riley, ME AF Ritchie, B Riley, ME TI Use of fast Fourier transform computational methods in electron scattering SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article DE fast Fourier transform; electron scattering; Schrodinger equation ID TIME-DEPENDENT APPROACH; WAVE-PACKET THEORY; IMPACT IONIZATION; SCHRODINGER-EQUATION; HYDROGEN SCATTERING; COUPLING METHOD; MODEL AB Two methods are studied for elastic electron-atom and electron-molecule elastic scattering. The first is a numerical solution of the time-dependent Schrodinger equation suitable for continuum states; the second is a convergent modified Born series of the time-independent integral Schrodinger (Lippmann-Schwinger) equation. Both methods make use of fast Fourier transform (FFT) computational methods in order to bring the free-electron Green's function into diagonal form. A large advantage of this methodology is the ability to describe scattering from targets of any geometry and at any collision energy by using 3D FFTs to accomplish the labor of evaluating spatially complex collision kernels. (C) 2002 Wiley Periodicals, Inc. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ritchie, B (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD OCT 15 PY 2002 VL 90 IS 2 BP 792 EP 798 DI 10.1002/qua.938 PG 7 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 595UE UT WOS:000178126500033 ER PT J AU Qian, Q Tyson, TA Dubourdieu, C Bossak, A Senateur, JP Deleon, M Bai, J Bonfait, G Maria, J AF Qian, Q Tyson, TA Dubourdieu, C Bossak, A Senateur, JP Deleon, M Bai, J Bonfait, G Maria, J TI Structural, magnetic, and transport studies of La0.8MnO3 films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; EPITAXIAL THIN-FILMS; MANGANITE FILMS; STRAIN; MAGNETORESISTANCE; ANISOTROPY; MAGNETOTRANSPORT; TRANSITION; DEPENDENCE; DISORDER AB A study of the properties of La0.8MnO3 films of varying thickness was performed. Transport and magnetization measurements show that the ferromagnetic (metallic) volume fraction of the film varies from similar to 1/4 for ultrathin 60 Angstrom films to similar to 1/2 for 1600 Angstrom films. Multilength scale structural measurements reveal that near 300 Angstrom, a transition from highly strained ultrathin films to relaxed bulk-like films occurs. The transition region is characterized by low surface roughness, high crystallite orientation, and broad d-spacing distributions. (C) 2002 American Institute of Physics. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Ecole Natl Super Electrochim & Electrome Grenoble, Mat & Genie Phys Lab, CNRS, UMR 5628, F-38402 St Martin Dheres, France. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Nucl & Technol Inst, Dept Chem, P-2686 Sacavem, Portugal. RP Qian, Q (reprint author), New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. EM tyson@adm.njit.edu RI BOSAK, Alexei/J-7895-2013; Bai, Jianming/O-5005-2015; OI Bonfait, Gregoire/0000-0003-3090-2884 NR 32 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 2002 VL 92 IS 8 BP 4518 EP 4523 DI 10.1063/1.1505667 PG 6 WC Physics, Applied SC Physics GA 599DC UT WOS:000178318000050 ER PT J AU Tchebotareva, A Brebner, JL Roorda, S Desjardins, P White, CW AF Tchebotareva, A Brebner, JL Roorda, S Desjardins, P White, CW TI Structural properties of InAs nanocrystals formed by sequential implantation of In and As ions in the Si (100) matrix SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GE NANOCRYSTALS; VISIBLE LUMINESCENCE; ROOM-TEMPERATURE; BEAM SYNTHESIS; SILICON; PHOTOLUMINESCENCE; LAYERS; GLASS AB The structural properties of InAs nanocrystals formed in Si by sequential implantation of In and As ions are studied in detail. We use a combination of x-ray diffraction, Rutherford backscattering spectroscopy, channeling, and transmission electron microscopy analyses to demonstrate that, regardless of the order in which ion species are implanted, InAs nanocrystals can be produced in Si (100) by means of sequential ion implantation complemented by subsequent thermal annealing. Whichever the order of implantation is, the nanocrystals are facetted and terminated by (111) planes, the epitaxial relationship being cube-on-cube, (100)(InAs)parallel to(100)(Si) with [001](InAs)parallel to[001](Si), for most InAs nanocrystals. The size distribution of nanocrystals is much affected by the sequence of implantation. With As ions implanted first, nanocrystals of different sizes are concentrated within one and the same layer under the sample's surface. In contrast, when In ions are implanted first, nanocrystals of different sizes are produced separately in space, forming a three-layer structure. As a consequence, inverting the order of implantation entails considerable changes in the morphology of the InAs nanocrystals obtained, affecting both their concentration profile and their size distribution. The result has a significant impact on the optical properties of the resulting samples. (C) 2002 American Institute of Physics. C1 Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Montreal, Grp Rech Phys & Technol Couches Minces, Montreal, PQ H3C 3J7, Canada. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Roorda, S (reprint author), Univ Montreal, Dept Phys, POB 6128,Stn Ctr Ville, Montreal, PQ H3C 3J7, Canada. RI Roorda, Sjoerd/N-2604-2014 NR 23 TC 6 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 2002 VL 92 IS 8 BP 4664 EP 4671 DI 10.1063/1.1507822 PG 8 WC Physics, Applied SC Physics GA 599DC UT WOS:000178318000072 ER PT J AU Wi, S Logan, JW Sakellariou, D Walls, JD Pines, A AF Wi, S Logan, JW Sakellariou, D Walls, JD Pines, A TI Rotary resonance recoupling for half-integer quadrupolar nuclei in solid-state nuclear magnetic resonance spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANGLE-SPINNING NMR; MAGIC-ANGLE; ROTATING SOLIDS; MAS NMR; DIPOLAR INTERACTIONS; PULSE SEQUENCE; QUANTUM NMR; SPINS; ECHO; POLARIZATION AB Investigations were made of rotary resonance recouplings (R-3) of chemical shift anisotropy (CSA), heteronuclear dipolar (HTD), and homonuclear dipolar (HMD) couplings involving half-integer quadrupolar nuclei under magic-angle sample spinning condition. Under rotary resonance conditions provided by a low amplitude rf field and a high spinning speed, the spectrum of the central transition coherence of half-integer quadrupolar nuclei shows recouplings of CSA, HTD, and HMD interactions that depend on the ratio of the rf field to the spinning speed. These new properties can be used to extract electronic and structural information about the sample that are otherwise difficult to extract in the presence of a dominant quadrupolar interaction. An average Hamiltonian theory is used to explain the recoupling properties of various interactions. Experimental implementations of the R-3 are demonstrated on model compounds with spin-3/2 systems. (C) 2002 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Pines, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM pines@cchem.berkeley.edu RI Sakellariou, Dimitrios/F-2846-2010 OI Sakellariou, Dimitrios/0000-0001-7424-5543 NR 53 TC 30 Z9 31 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 15 PY 2002 VL 117 IS 15 BP 7024 EP 7033 DI 10.1063/1.1506907 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 599CV UT WOS:000178317300016 ER PT J AU Liu, DJ Evans, JW AF Liu, DJ Evans, JW TI Fluctuations and bistability in a "hybrid" atomistic model for CO oxidation on nanofacets: An effective potential analysis SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SURFACE-REACTION MODEL; PERCOLATION TRANSITIONS; PHASE-TRANSITIONS; FIELD-EMISSION; KINETICS; EQUILIBRIUM; ADSORBATES; DYNAMICS; SYSTEMS; EMITTER AB We analyze fluctuations in a "hybrid" atomistic model mimicking CO oxidation on nanoscale facets of metal(100) catalyst surfaces. The model incorporates a mean-field-like treatment of infinitely mobile CO, and a lattice-gas treatment of the superlattice ordering of immobile O. For an infinite system, it exhibits an Ising-type order-disorder transition for O, together with mean-field-like bistability disappearing at a cusp bifurcation. For finite systems, we use kinetic Monte Carlo simulation to study the probability distribution for the population of adsorbed species, from which bistability can be observed, together with fluctuation-induced transitions between the two stable states. An effective potential picture emerges from our analyses that can be used to quantify both the system size dependence of fluctuations and the transition rates. Thus, our hybrid atomistic model displays fluctuation behavior analogous to traditional mean-field models. This qualitative behavior can be understood by approximate treatments of population dynamics using master equations and Fokker-Planck equations. A generalized model with finite mobility of CO is also analyzed for comparison with the hybrid model. In contrast, it exhibits fluctuation behavior akin to equilibrium systems with Ising-type first-order transitions. (C) 2002 American Institute of Physics. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. RP Liu, DJ (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 35 TC 30 Z9 30 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 15 PY 2002 VL 117 IS 15 BP 7319 EP 7328 DI 10.1063/1.1507105 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 599CV UT WOS:000178317300048 ER PT J AU Wildenschild, D Hopmans, JW Vaz, CMP Rivers, ML Rikard, D Christensen, BSB AF Wildenschild, D Hopmans, JW Vaz, CMP Rivers, ML Rikard, D Christensen, BSB TI Using X-ray computed tomography in hydrology: systems, resolutions, and limitations SO JOURNAL OF HYDROLOGY LA English DT Article DE porous media; multi-phase flow; X-ray tomography; synchrotron radiation; pore structure; visualization ID CAPILLARY-PRESSURE; POROUS-MEDIA; PLANT-ROOTS; MICROTOMOGRAPHY; FLOW; SANDSTONE; NETWORKS; IMAGES; ROCKS AB A combination of advances in experimental techniques and mathematical analysis has made it possible to characterize phase distribution and pore geometry in porous media using non-destructive X-ray computed tomography (CT). We present qualitative and quantitative CT results for partially saturated media, obtained with different scanning systems and sample sizes, to illustrate advantages and limitations of these various systems, including topics of spatial resolution and contrast. In addition, we present examples of our most recent three-dimensional high-resolution images, for which it was possible to resolve individual pores and to delineate air-water interfacial contacts. This kind of resolution provides a novel opportunity to follow the dynamic flow behavior on the pore scale and to verify new theoretical and numerical modeling approaches. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Tech Univ Denmark, DK-2800 Lyngby, Denmark. Lawrence Livermore Natl Lab, Expt Geophys Grp, Earth & Environm Sci Directorate, Livermore, CA 94551 USA. Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA. CNPDIA, Embrapa Agr Instrumentat, BR-13560970 Sao Carlos, SP, Brazil. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Lawrence Livermore Natl Lab, Nondestruct Evaluat Sect, Livermore, CA 94551 USA. RP Wildenschild, D (reprint author), Tech Univ Denmark, DK-2800 Lyngby, Denmark. EM dw@er.dtu.dk; jwhopmans@ucdavis.edu; vaz@cnpdia.embrapa.br; rivers@cars.uchicago.edu; rikard1@llnl.gov; brc@er.dtu.dk RI Vaz, Carlos/F-6030-2012; Vaz, Carlos/A-6941-2013; OI Wildenschild, Dorthe/0000-0002-6504-7817; Manoel Pedro Vaz, Carlos/0000-0003-1336-8958 NR 31 TC 249 Z9 253 U1 6 U2 76 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD OCT 15 PY 2002 VL 267 IS 3-4 BP 285 EP 297 AR PII S0022-1694(02)00157-9 DI 10.1016/S0022-1694(02)00157-9 PG 13 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 602KR UT WOS:000178504900013 ER PT J AU Lewin, SR Ribeiro, RM Kaufmann, GR Smith, D Zaunders, J Law, M Solomon, A Cameron, PU Cooper, D Perelson, AS AF Lewin, SR Ribeiro, RM Kaufmann, GR Smith, D Zaunders, J Law, M Solomon, A Cameron, PU Cooper, D Perelson, AS TI Dynamics of T cells and TCR excision circles differ after treatment of acute and chronic HIV Infection SO JOURNAL OF IMMUNOLOGY LA English DT Article; Proceedings Paper CT 8th Conference on Retroviruses and Opportunistic Infections CY FEB 04-08, 2001 CL CHICAGO, ILLINOIS ID ACTIVE ANTIRETROVIRAL THERAPY; RECENT THYMIC EMIGRANTS; IMMUNODEFICIENCY-VIRUS-INFECTION; LYMPHOID-TISSUES; CD4(+); LYMPHOCYTES; TURNOVER; BLOOD; NAIVE; HOMEOSTASIS AB We quantified T cell proliferation and thymic function in primary HIV infection (PHI; n.= 19) and chronic HIV infection (CHI; n = 14) by measuring Ki67 staining and TCR excision circle (TREC) number. After antiretroviral therapy of PHI there is a profound decrease in the number and percentage of Ki67(+) T cells (<6% Ki67(+)) with no significant increase in TREC per million cells and a transient increase in TREC per milliliter. In contrast, after antiretroviral therapy of CHI there is a reduction in the percentage but little change in the total number of Ki67(+)CD4(+) T cells associated with increases in both TREC per million cells and TREC per milliliter. Using a mathematical model that accounts for proliferation, death, and redistribution of T cells, we find that redistribution is consistent with the TREC changes observed during treatment of PHI and that an increase in thymic output is needed to explain the increase in TREC during treatment of CHI. Consideration of TREC per milliliter shows that changes in proliferation alone cannot explain the changes in TREC. In addition, although increased proliferation of memory cells in HIV infection has been established, we find no difference in TREC per million CD45RA(-) "memory" T cells between healthy and infected individuals (P = 0.154 for CD4(+); p = 0.383 for CD8(+)). Finally, although the number of TREC per million cells is always much lower in memory T cells than in naive T cells, in the setting of HIV infection, given that memory cells make up a larger proportion of total T cells, we find that 50% of TREC per milliliter in CD4(+) T cells is harbored in the CD45RA(-) "memory" subset. of our infected subjects. C1 Univ Melbourne, Dept Microbiol & Immunol, Parkville, Vic 3052, Australia. St Vincents Hosp, Ctr Immunol, Sydney, NSW 2010, Australia. Univ New S Wales, Natl Ctr HIV Epidemiol & Clin Res, Sydney, NSW, Australia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Royal Melbourne Hosp, Victorian Infect Dis Serv, Parkville, Vic 3050, Australia. RP Lewin, SR (reprint author), Univ Melbourne, Dept Microbiol & Immunol, Royal Parade, Parkville, Vic 3052, Australia. RI Zaunders, John/J-6553-2012; OI Zaunders, John/0000-0002-5912-5989; Cameron , Paul Urquhart/0000-0002-1906-6945; Lewin, Sharon Ruth/0000-0002-0330-8241 FU NCRR NIH HHS [RR 06555]; NIAID NIH HHS [AI 28433] NR 37 TC 41 Z9 41 U1 0 U2 0 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD OCT 15 PY 2002 VL 169 IS 8 BP 4657 EP 4666 PG 10 WC Immunology SC Immunology GA 602NU UT WOS:000178512000076 PM 12370406 ER PT J AU Wheelock, PB Wongpreedee, K Russell, AM Chumbley, LS AF Wheelock, PB Wongpreedee, K Russell, AM Chumbley, LS TI A deformation processed beta-Ti+Y metal-metal composite SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID STRENGTH; ALLOYS; MICROSTRUCTURE; TITANIUM; YTTRIUM; WIRES AB A Ti-20V-20Y deformation processed metal-metal composite was deformed axisymmetrically by extrusion and swaging to a true strain of 5.9. Tensile strength, ductility, Y phase thickness and spacing, and preferred crystallographic orientation were examined at several levels of true strain as the deformation progressed. The Ti-V metastable BCC solid solution matrix developed a [10 (1) over bar0] fiber texture. The Y second phase developed a [110] fiber texture that constrained the Y phase to deform in plane strain. Relatively high tensile ductility was observed at all levels of deformation processing strain. (C) 2002 Kluwer Academic Publishers. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Wheelock, PB (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 15 TC 0 Z9 0 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD OCT 15 PY 2002 VL 37 IS 20 BP 4307 EP 4313 DI 10.1023/A:1020644317324 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 604BP UT WOS:000178596000006 ER PT J AU Lee, M Xiao, YN Wittmer, DE Graber, TJ Mini, SM AF Lee, M Xiao, YN Wittmer, DE Graber, TJ Mini, SM TI Residual stresses in particle-reinforced ceramic composites using synchrotron radiation SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB Residual stresses were determined in particle-reinforced ceramic composites using synchrotron based x-ray diffraction. The baseline Si3N4 and the Si3N4-TiN composites were processed by turbomilling, pressure casting, and isopressing. They were then continuously sintered to full density, under a pressureless, flowing nitrogen atmosphere. The flexural strength, fracture toughness, and residual stress were measured for as-machined samples and following quenching in water from 1000degreesC, 1100degreesC, and 1200degreesC. The residual stresses for both the baseline Si3N4 and the Si3N4-TiN composites were determined from the (441) and (531) reflections, by applying the 2theta-sin(2)psi method. The measured residual stresses were compared with the flexural strength and fracture toughness results to determine the effects of residual stress and thermal shocking on the mechanical properties of each material. In both the baseline Si3N4 and Si3N4-TiN composites, after thermal shocking, the compressive residual stresses were developed in directions both parallel and perpendicular to the sample surface. The residual compressive stresses for the Si3N4-TiN composites were much higher than the baseline Si3N4. As a result, both fracture toughness and flexural strength of the Si3N4-TiN composites were improved. In addition, the addition of the TiN appears to improve both the strength and toughness of the baseline Si3N4. (C) 2002 Kluwer Academic Publishers. C1 So Illinois Univ, Dept Mech Engn & Energy Proc, Carbondale, IL 62901 USA. Univ Chicago, Ctr Adv Radiat Sources, Chicago, IL 60637 USA. No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lee, M (reprint author), So Illinois Univ, Dept Mech Engn & Energy Proc, Carbondale, IL 62901 USA. NR 23 TC 4 Z9 4 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD OCT 15 PY 2002 VL 37 IS 20 BP 4437 EP 4443 DI 10.1023/A:1020637527319 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 604BP UT WOS:000178596000024 ER PT J AU Ritter, C Heyde, M Schwarz, UD Rademann, K AF Ritter, C Heyde, M Schwarz, UD Rademann, K TI Controlled translational manipulation of small latex spheres by dynamic force microscopy SO LANGMUIR LA English DT Article ID PLOWING NANOLITHOGRAPHY; CONTACT DEFORMATIONS; SURFACE FORCES; PARTICLES; ADHESION; NANOPARTICLES; FABRICATION; CLUSTERS; FRICTION; TOOL AB We report on the application of a home-built scanning force microscope for translation and in-plane rotation of nanometer-sized latex spheres by dynamic surface modification (DSM). This technique is based on the increment of the amplitude of the oscillating voltage applied at the dither piezo that drives the cantilever vibrations in the dynamic mode of scanning force microscopy. Thus, it is easily possible to switch between the imaging mode and DSM mode, enabling the direct manipulation of nanostructures under ambient conditions with high precision. The main advantage of our technique compared to earlier methods is that it operates with an active feedback loop, allowing a steady manipulation of nanostructures independent of the surface corrugation or sample tilt. Such controlled translations of latex spheres enable us in addition to study their properties regarding friction, adhesion, and cohesion. By translating latex spheres of different sizes (radii between 50 and 110 nm), it was found that the force needed to move a particle depends on its dimensions. Finally, the lateral translation of an intentionally marked sphere gives evidence that sliding is preferred over rolling. C1 Humboldt Univ, Inst Chem, D-12489 Berlin, Germany. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. RP Ritter, C (reprint author), Humboldt Univ, Inst Chem, Brook Taylor Str 2, D-12489 Berlin, Germany. EM claudia.ritter@epost.de RI Heyde, Markus/F-9150-2013; OI Heyde, Markus/0000-0002-7049-0485; Rademann, Klaus/0000-0003-3084-3917 NR 40 TC 50 Z9 51 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 15 PY 2002 VL 18 IS 21 BP 7798 EP 7803 DI 10.1021/la011318n PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 603YW UT WOS:000178589700010 ER PT J AU Vance, AL Willey, TM Nelson, AJ van Buuren, T Bostedt, C Terminello, LJ Fox, GA Engelhard, M Baer, D AF Vance, AL Willey, TM Nelson, AJ van Buuren, T Bostedt, C Terminello, LJ Fox, GA Engelhard, M Baer, D TI XAS and XPS characterization of monolayers derived from a dithiol and structurally related disulfide-containing polyamides SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; ENHANCED RAMAN-SCATTERING; X-RAY; GOLD SURFACES; MULTILAYER FORMATION; ORIENTATIONAL ORDER; CDS-NANOPARTICLE; FILMS; ADSORPTION; AU(111) AB X-ray absorption spectroscopy and X-ray photoemission spectroscopy have been used to examine sulfur-gold bond formation in monolayers derived from a dithiol monomer and related disulfide-containing polyamides. These compounds were designed to allow the molecules to adsorb to gold through two terminal sulfurs, forming surface-attached loops. Element and site-specific density of unoccupied electronic states were probed by X-ray absorption spectroscopy at the C 1s, N 1s, O 1s (K-edge), and S 2p (L-2,L-3-edge) absorption edges. Photoemission measurements of the C 1s, N 1s, O 1s, and S 2p core lines were also used to estimate relative coverage, to confirm layer formation, and to evaluate chemical bonding of the monomer and polyamide to the gold-coated substrates. In the case of the dithiol monomer, the spectroscopic evidence clearly shows that most of the molecules adsorb through a single thiol end. The disulfide-containing precursors, in contrast to the monomer, attach to the surface through both sulfurs to form the anticipated surface - attached loop. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Vance, AL (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 5508, Livermore, CA 94550 USA. RI Engelhard, Mark/F-1317-2010; Willey, Trevor/A-8778-2011; Baer, Donald/J-6191-2013; OI Willey, Trevor/0000-0002-9667-8830; Baer, Donald/0000-0003-0875-5961; Engelhard, Mark/0000-0002-5543-0812 NR 45 TC 43 Z9 43 U1 0 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 15 PY 2002 VL 18 IS 21 BP 8123 EP 8128 DI 10.1021/la025631g PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 603YW UT WOS:000178589700054 ER PT J AU De Solorzano, CO Costes, S Callahan, DE Parvin, B Barcellos-Hoff, MH AF De Solorzano, CO Costes, S Callahan, DE Parvin, B Barcellos-Hoff, MH TI Applications of quantitative digital image analysis to breast cancer research SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Article DE mammary gland; carcinogenesis; genomic instability; transforming growth factor-beta; ionizing radiation ID GROWTH-FACTOR-BETA; GENE-EXPRESSION; BASEMENT-MEMBRANE; MAMMARY-GLAND; NUCLEAR-ORGANIZATION; EXTRACELLULAR-MATRIX; RADIATION-THERAPY; MALIGNANT BREAST; EPITHELIAL-CELLS; TISSUE STRUCTURE AB Our studies of radiogenic carcinogenesis in mouse and human models of breast cancer are based on the view that cell phenotype, microenvironment composition, communication between cells and within the microenvironment are important factors in the development of breast cancer. This is complicated in the mammary gland by its postnatal development, cyclic evolution via pregnancy and involution, and dynamic remodeling of epithelial-stromal interactions, all of which contribute to breast cancer susceptibility. Microscopy is the tool of choice to examine cells in context. Specific features can be defined using probes, antibodies, immunofluorescence, and image analysis to measure protein distribution, cell composition, and genomic instability in human and mouse models of breast cancer. We discuss the integration of image acquisition, analysis, and annotation to efficiently analyze large amounts of image data. In the future, cell and tissue image-based studies will be facilitated by a bioinformatics strategy that generates multidimensional databases of quantitative information derived from molecular, immunological, and morphological probes at multiple resolutions. This approach will facilitate the construction of an in vivo phenotype database necessary for understanding when, where, and how normal cells become cancer. C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Comp Sci, Berkeley, CA 94720 USA. RP Barcellos-Hoff, MH (reprint author), Lawrence Berkeley Natl Lab, Div Life Sci, Bldg 74-174,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM NIHBarcelIos-Hoff@lbl.gov RI Ortiz de Solorzano, Carlos/G-3278-2010; Costes, Sylvain/D-2522-2013 OI Ortiz de Solorzano, Carlos/0000-0001-8720-0205; Costes, Sylvain/0000-0002-8542-2389 NR 38 TC 9 Z9 9 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1059-910X EI 1097-0029 J9 MICROSC RES TECHNIQ JI Microsc. Res. Tech. PD OCT 15 PY 2002 VL 59 IS 2 BP 119 EP 127 DI 10.1002/jemt.10183 PG 9 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA 604EF UT WOS:000178602700005 ER PT J AU Zheng, X Ravatn, R Lin, Y Shih, WC Rabson, A Strair, R Huberman, E Conney, A Chin, KV AF Zheng, X Ravatn, R Lin, Y Shih, WC Rabson, A Strair, R Huberman, E Conney, A Chin, KV TI Gene expression of TPA induced differentiation in HL-60 cells by DNA microarray analysis SO NUCLEIC ACIDS RESEARCH LA English DT Article ID PROTEIN-KINASE-C; MYELOID-LEUKEMIA CELLS; ESTER-INDUCED DIFFERENTIATION; FINGER TRANSCRIPTION FACTOR; NECROSIS-FACTOR-ALPHA; TRANS-RETINOIC ACID; MACROPHAGE DIFFERENTIATION; MONOCYTIC DIFFERENTIATION; HL60 CELLS; GROWTH AB The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) is a potent inducer of differentiation in human promyelocytic leukemia cells. Recently, TPA has been successfully administered to patients with myelocytic leukemia and has produced therapeutic effects that led to temporary remission. These studies demonstrated the potential efficacy of TPA in cancer chemotherapy. We now seek to understand the biological effects and molecular mechanisms of differentiation in response to TPA treatment in leukemia cells by expression profiling using DNA microarray. Our results show distinct temporal and coordinated gene changes that are consistent with differentiation and activation of multiple biochemical pathways in HL-60 cells exposed to TPA. Alterations of gene expression in HL-60 cells include various transcription factors, cytokines and protein markers that are consistent with the induction of differentiation elicited by TPA. These temporal patterns of gene expression were abolished or greatly diminished in an HL-60 derived TPA- resistant variant cell line (HL-525), thus revealing transcriptional and consequential biochemical changes that may be required for TPA-induced differentiation. In addition, certain genes were upregulated by TPA in TPA-resistant HL-525 cells but not in TPA-sensitive HL-60 cells suggesting that these genes may play a role in the resistant pheno type. These patterns of gene expression may be important for predicting response to TPA. C1 Rutgers State Univ, Coll Pharm, Dept Biol Chem, Canc Res Lab, Piscataway, NJ 08854 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Canc Inst New Jersey, New Brunswick, NJ 08901 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Mol Genet & Microbiol, Piscataway, NJ 08854 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Ctr Adv Biotechnol & Med, Piscataway, NJ 08854 USA. Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. RP Chin, KV (reprint author), Rutgers State Univ, Coll Pharm, Dept Biol Chem, Canc Res Lab, 164 Frelinghuysen Rd, Piscataway, NJ 08854 USA. RI Chin, Khew-Voon/F-2670-2013 FU NCI NIH HHS [R01 CA080826, CA 80826] NR 66 TC 43 Z9 49 U1 1 U2 1 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 OCT 15 PY 2002 VL 30 IS 20 BP 4489 EP 4499 DI 10.1093/nar/gkf580 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 608CC UT WOS:000178826700027 PM 12384596 ER PT J AU Peele, AG McMahon, PJ Paterson, D Tran, CQ Mancuso, AP Nugent, KA Hayes, JP Harvey, E Lai, B McNulty, I AF Peele, AG McMahon, PJ Paterson, D Tran, CQ Mancuso, AP Nugent, KA Hayes, JP Harvey, E Lai, B McNulty, I TI Observation of an x-ray vortex SO OPTICS LETTERS LA English DT Article ID OPTICAL VORTICES; LASER-BEAMS AB Phase singularities are a ubiquitous feature of waves of all forms and represent a fundamental aspect of wave topology. An optical vortex phase singularity occurs when there is a spiral phase ramp about a point phase singularity. We report an experimental observation of an optical vortex in a field consisting of 9-keV x-ray photons. The vortex is created with an x-ray optical structure that imparts a spiral phase distribution to the incident wave field and is observed by use of diffraction about a wire to create a division-of-wave-front interferometer. (C) 2002 Optical Society of America. C1 Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. Swinburne Univ Technol, Ind Res Inst, Hawthorn, Vic 3122, Australia. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Peele, AG (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. RI Nugent, Keith/J-2699-2012; Tran, Chanh/M-7868-2015; Nugent, Keith/I-4154-2016 OI Nugent, Keith/0000-0003-1522-8991; Nugent, Keith/0000-0002-4281-3478 NR 16 TC 74 Z9 76 U1 0 U2 13 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD OCT 15 PY 2002 VL 27 IS 20 BP 1752 EP 1754 DI 10.1364/OL.27.001752 PG 3 WC Optics SC Optics GA 603LP UT WOS:000178561300002 PM 18033352 ER PT J AU Qiao, ZJ Strampp, W AF Qiao, ZJ Strampp, W TI Negative order MKdV hierarchy and a new integrable Neumann-like system SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article DE negative order; positive order; MKdV hierarchy; lax representation; Neumann-like system; parametric solution ID PEAKED SOLITONS; EQUATION; FLOWS; PDES AB The purpose of this paper is to develop the negative order MKdV hierarchy and to present a new related integrable Neumann-like Hamiltonian flow from the view point of inverse recursion operator and constraint method. The whole MKdV hierarchy both positive and negative is generated by the kernel elements of Lenard's operators pair and recursion operator. Through solving a key operator equation, the whole NMdV hierarchy is shown to have the Lax representation. In particular, some new integrable equation together with the Liouville equations, the sine-Gordon equation, and the sinh-Gordon equation are derived from the negative order MKdV hierarchy. It is very interesting that the restricted flow, corresponding to the negative order MKdV hierarchy, is just a new kind of Neumann-like system. This new Neumann-like system is obtained through restricting the NMdV spectral problem onto a symplectic submanifold and is proven to be completely integrable under the Dirac-Poisson bracket, which we define on the symplectic submanifold. Finally, with the help of the constraint between the Neumann-like system and the negative order MKdV hierarchy, all equations in the hierarchy are proven to have the parametric representations of solutions. In particular, we obtain the parametric solutions of the sine-Gordon equation and the sinh-Gordon equation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CNLS, Los Alamos, NM 87545 USA. Fudan Univ, Inst Math, Shanghai 200433, Peoples R China. Univ Gesamthsch Kassel, Fachbereich 17, D-34109 Kassel, Germany. RP Qiao, ZJ (reprint author), Los Alamos Natl Lab, MS B-284,T-7, Los Alamos, NM 87545 USA. NR 35 TC 26 Z9 28 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD OCT 15 PY 2002 VL 313 IS 3-4 BP 365 EP 380 AR PII S0378-4371(02)00995-0 DI 10.1016/S0378-4371(02)00995-0 PG 16 WC Physics, Multidisciplinary SC Physics GA 617JF UT WOS:000179358000007 ER PT J AU Schwenterly, SW Mehta, SP Walker, MS Jones, RH AF Schwenterly, SW Mehta, SP Walker, MS Jones, RH TI Development of HTS power transformers for the 21st century: Waukesha Electric Systems/IGC-SuperPower/RG&E/ORNL SPI collaboration SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE HTS transformers; electric power applications AB The collaboration among Waukesha Electric Systems (WES), IGC-SuperPower (IGC-SP), Rochester Gas & Electric (RG&E), and Oak Ridge National Laboratory (ORNL) is now in Phase II. This is a US DoE cost-shared Superconductivity Partnership Initiative (SPI) Project, with the objective of developing a conceptual design for a commercial 30-MVA superconducting utility power transformer, and furthermore designing and building a prototype 5/10-MVA transformer that will be operated on the utility power grid at the main WES plant in Waukesha, WL The design approach for both of these transformers is to place both the core and cold mass inside the vacuum tank. Commercial cryocoolers are used to cool the superconducting windings below 40 K. This approach avoids the use of expensive non-conducting cryostats. It allows a flexible tradeoff between operating temperature and length of conductor to produce a cost-optimized design with the best currently available conductor. Activities in the participant organizations will be summarized as follows: WES-core cooling and conventional component design, IGC-SP-superconducting coil, coil cooling and lead development and cryogenic suspension, ORNL-AC loss measurements, cryogenic dielectric tests, and cryogenic cooling module design, and RG&E-operational needs and utility perspectives. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Waukesha Elect Syst, Waukesha, WI 53186 USA. IGC SuperPower, Schenectady, NY 12304 USA. Rochester Gas & Elect Corp, Rochester, NY 14649 USA. RP Schwenterly, SW (reprint author), Oak Ridge Natl Lab, POB 2009,Bldg 9201-2,MS 8071, Oak Ridge, TN 37831 USA. NR 8 TC 16 Z9 18 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 1 EP 6 AR PII S0921-4534(02)01168-1 DI 10.1016/S0921-4534(02)01168-1 PG 6 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700002 ER PT J AU Willis, JO AF Willis, JO TI Proceedings of the 10th US-Japan Workshop on High-T-c Superconductors - Santa Fe, NM, USA - December 2-5, 2001 - Preface SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Editorial Material C1 Los Alamos Natl Lab, Supercond Technol Ctr, Los Alamos, NM 87545 USA. RP Willis, JO (reprint author), Los Alamos Natl Lab, Supercond Technol Ctr, Mail Stop T004, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP VII EP VII AR PII S0921-4534(02)01164-4 DI 10.1016/S0921-4534(02)01164-4 PG 1 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700001 ER PT J AU Maroni, VA Venkataraman, K Kropf, AJ Segre, CU Huang, Y Riley, GN AF Maroni, VA Venkataraman, K Kropf, AJ Segre, CU Huang, Y Riley, GN TI Nondestructive analysis of phase evolution and microstructure development in Ag/(Bi,Pb)(2)Sr2Ca2Cu3Ox composite superconductor by 25 keV transmission X-ray diffraction SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE Bi-2223/Ag tape; X-ray diffraction; fiber texture ID IN-SITU; TEXTURE; TAPES AB X-ray diffraction (XRD) measurements were made on silver-sheathed (Bi,Pb)(2)Sr2Ca2Cu3Ox (Ag/Bi-2223) composite superconductor using 25 keV X-rays produced by an insertion device beamline at a third generation synchrotron. These measurements, performed on fully sheathed multifilament-type Ag/Bi-2223 wire specimens, provided. high resolution diffraction patterns that revealed (1) the phases present in the cores of the superconducting filaments and (2) the nature and quality of the Bi-2223 grain colony texture. In addition to the Bi-2223 phase, we were able to detect and to monitor specimen-to-specimen variations in the relative amounts of Bi-2212, Bi-2201, and the "3221" phase. The scattering geometry used (X-ray beam perpendicular to the Ag/Bi-2223 conductor rolling direction) resulted in the detection of several remarkably intense diffraction lines of Bi-2223, most notably the (200)/(020) pair, that were highly useful for recording pole figure maps evidencing the contiguous fiber texture microstructure of the Bi-2223 grain colonies. The nondestructive nature of the 25 keV transmission XRD method offers many advantages for the comprehensive study of phase evolution and microstructure development in Ag/Bi-2223 composite conductors. (C) 2002 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. IIT, Chicago, IL 60616 USA. Amer Supercond, Westborough, MA 01581 USA. RP Maroni, VA (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave,Bldg 205, Argonne, IL 60439 USA. RI Segre, Carlo/B-1548-2009; ID, MRCAT/G-7586-2011 OI Segre, Carlo/0000-0001-7664-1574; NR 11 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 21 EP 26 AR PII S0921-4534(02)01198-X DI 10.1016/S0921-4534(02)01198-X PG 6 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700006 ER PT J AU Ma, B Li, M Fisher, BL Koritala, RE Balachandran, U AF Ma, B Li, M Fisher, BL Koritala, RE Balachandran, U TI Inclined-substrate deposition of biaxially aligned template films for YBCO-coated conductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE YBCO-coated conductor; inclined-substrate deposition ID THIN-FILMS; MGO AB Inclined-substrate deposition (ISD) of magnesium oxide (MgO) produces biaxially textured template films at high deposition rates. This process is promising for the fabrication of the second-generation superconducting wires. Biaxially aligned MgO films (approximate to1.5 mum thick) were deposited on polished Hastelloy C276 (HC) substrates by ISD at deposition rates of 20-100 Angstrom/s. Buffer films were subsequently deposited on these template films, and YBCO films were deposited epitaxially on the substrates by pulsed laser deposition. X-ray pole figure analysis and phi- and omega-scans were used for texture characterization. Good in- and out-of-plane textures were observed, with MgO(002) phi-scan full-width at half maximum (FWHM) of 9.2degrees and omega-scan FWHM of 5.4degrees, respectively. T, of 90 K with a sharp transition, and J(c) approximate to 2 x 10(5) A/cm(2), were obtained on a 0.5 mum thick, 0.5 cm wide, and 1 cm long YBa2Cu3O7-delta (YBCO) film at 77 K in self-field. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Ma, B (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Koritala, Rachel/F-1774-2011; Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 12 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 38 EP 42 AR PII S0921-4534(02)01193-0 DI 10.1016/S0921-4534(02)01193-0 PG 5 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700009 ER PT J AU Groves, JR Arendt, PN Foltyn, SR Jia, QX Holesinger, TG Kung, H DePaula, RF Dowden, PC Peterson, EJ Stan, L Emmert, LA AF Groves, JR Arendt, PN Foltyn, SR Jia, QX Holesinger, TG Kung, H DePaula, RF Dowden, PC Peterson, EJ Stan, L Emmert, LA TI Recent progress in continuously processed IBAD MgO template meters for HTS applications SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE YBCO coated conductor; ion beam assisted deposition; reflected high-energy electron diffraction; biaxial texture; magnesium oxide ID BEAM-ASSISTED DEPOSITION; YTTRIA-STABILIZED-ZIRCONIA; COATED CONDUCTORS; THIN-FILMS; LAYERS AB We discuss our recent progress using IBAD MgO as a template for subsequent deposition of YBa2Cu3O7-delta (YBCO) high-temperature superconductors on metallic substrate tapes. We have refined the process by improving substrate preparation and by using reflected high-energy electron diffraction to monitor and improve IBAD MgO films. High quality, continuously processed IBAD MgO (c-IBAD) has been deposited on moving meter-length metal tape. By incorporating these optimized processing parameters, we have been able to deposit biaxially textured MgO on metallic substrates continuously with the best in-plane mosaic spreads near 9degrees. The subsequent pulsed laser deposition of 1-2 mum thick YBCO films on c-IBAD has resulted in superconducting transport critical current densities > 1 MA/cm(2) (75 K, SF) on small area samples. Longer 4.5 cm samples of c-IBAD tape have also been coated with a I cm wide sample carrying 93 A (75 K, SF) for a 1.5 mum thick YBCO. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Groves, JR (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Mailstop K763, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 11 TC 25 Z9 26 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 43 EP 47 AR PII S0921-4534(02)01194-2 DI 10.1016/S0921-4534(02)01194-2 PG 5 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700010 ER PT J AU Blaugher, RD Bhattacharya, RN Chen, J Padmanabhan, R AF Blaugher, RD Bhattacharya, RN Chen, J Padmanabhan, R TI Alternative HTS coated conductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE Hg-based cuprates; Tl-based cuprates; Bi-2212 coated conductor; electrodeposition; electric power applications ID CRITICAL-CURRENT DENSITY; THALLIUM OXIDE-FILMS; THICK-FILMS; PRECURSORS; SPRAY; TAPES; WIRES AB The availability of Bi-2223 high-temperature-superconductor (HTS) powder-in-tube (PIT) tape, with acceptable performance for long lengths, has provided the ability to construct a wide range of HTS electric power components. As a result, there are major worldwide projects in developing FITS electric power components for demonstration in a utility environment. Utility acceptance for superconducting power equipment will depend on several key factors: improved system performance, lower life-cycle costs, higher efficiency versus conventional technology, reliability and maintenance comparable to conventional power equipment, and a competitive installed cost. The latter is impacted by the current high cost of HTS conductors, which must be lowered to costs comparable to conventional Nb-Ti wire, i.e., $2-5/kAm. The present performance and cost of state-of-the-art Bi-2223 HTS tape, although acceptable for prototype construction, is viewed as a major deterrent that may compromise eventual commercialization for most of these electric power devices. The so-called second-generation coated conductor development, with emphasis on conductors employing HTS YBCO films, is viewed as the solution to this performance and cost issue. The potential for the TI, Hg, and Bi-oxide superconductors for producing an HTS tape as alternatives to Bi-2223 PIT (and YBCO) will be discussed with some recent results on Bi-2212 "coated conductor" development. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Blaugher, RD (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 24 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 72 EP 79 AR PII S0921-4534(02)01201-7 DI 10.1016/S0921-4534(02)01201-7 PG 8 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700016 ER PT J AU Bud'ko, SL Canfield, PC Kogan, VG AF Bud'ko, SL Canfield, PC Kogan, VG TI Magnesium, diboride: basic physical properties and high upper critical field anisotropy SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE magnesium diboride; synthesis; upper critical field; anisotropy ID MGB2 SINGLE-CRYSTALS; SUPERCONDUCTING PROPERTIES; MAGNETIZATION DATA; THIN-FILMS; TRANSPORT AB We will briefly outline recent work done by the Ames Laboratory group and collaborators on synthesis and physical properties of newly discovered intermetallic superconductor, MgB2 (T-c approximate to 40 K), produced in the form of sintered powder and wire segments with the emphasis to be on recent results that indicate that MgB2 may well have significant anisotropies associated with the superconducting state. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. RP Bud'ko, SL (reprint author), Iowa State Univ, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 29 TC 15 Z9 15 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 85 EP 92 AR PII S0921-4534(02)01203-0 DI 10.1016/S0921-4534(02)01203-0 PG 8 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700018 ER PT J AU Meng, RL Lorenz, B Wang, YS Cmaidalka, J Sun, YY Xue, YY Meen, JK Chu, CW AF Meng, RL Lorenz, B Wang, YS Cmaidalka, J Sun, YY Xue, YY Meen, JK Chu, CW TI Study of binary and pseudo-binary intermetallic compounds with AlB2 structure SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE AlB2 structure; intermetallic compounds; valence electron number; lattice parameter ID MGB2; SUPERCONDUCTIVITY; BORON AB We have synthesized and studied the binary intermetallic compounds, AGa(2) and A[GaxSi2-x] (A= Sr, Ba, Ca), which are isostructural to the newly discovered 40 K superconductor MgB2. The binary compounds AGa(2) were found to be non-superconducting above 2 K, even though they have the same valence electron number per formula as MgB2 and greater lattice parameters than MgB2. However, by varying the valence electron number, they become superconducting. This result suggests that the electronic structures of this class of compounds depend on more than just the valence electron density and the lattice parameters. The theoretical prediction that the T-c of MgB2 could be enhanced with the proper dopant to increase its carrier density or to expand the lattice could not be verified. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Houston, Dept Phys, Houston Sci Ctr 202, Houston, TX 77204 USA. Univ Houston, Texas Ctr Superconduct, Houston Sci Ctr 202, Houston, TX 77204 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Hong Kong Univ Sci & Technol, Hong Kong, Hong Kong, Peoples R China. RP Meng, RL (reprint author), Univ Houston, Dept Phys, Houston Sci Ctr 202, Houston, TX 77204 USA. NR 7 TC 26 Z9 26 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 113 EP 116 AR PII S0921-4534(02)01208-X DI 10.1016/S0921-4534(02)01208-X PG 4 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700023 ER PT J AU Maple, MB Taylor, BJ Frederick, NA Li, S Nesterenko, VF Indrakanti, SS Maley, MP AF Maple, MB Taylor, BJ Frederick, NA Li, S Nesterenko, VF Indrakanti, SS Maley, MP TI Critical scaling and flux dynamics in bulk MgB2 and high-purity YBa2Cu3O7-delta single crystals SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE MgB2; YBa2Cu3O7-delta; vortex dynamics; critical scaling ID BA-CU-O; SUPERCONDUCTING PROPERTIES; FLUCTUATIONS; TRANSPORT; PHASE AB A dense sample of MgB2 (T-c = 38.5 K) was synthesized under 200 MPa pressure using a novel hot isostatic pressing (HIPing) technique, and a high-purity single crystal of YBa2Cu3O7-delta (T-c = 93.5 K) was grown in a home-made BaZrO3 crucible. Electric field vs current density (E-J) isotherms of the MgB2 and YBa2Cu3O7-delta high-temperature superconductors were measured and analyzed in terms of the critical scaling model. E-J isotherm sets were taken at fields ranging from 2 to 90 kOe. Scaling and resistivity data reveal a smooth transition from a vortex glass to a vortex liquid state for the bulk MgB2 sample and the existence of both a vortex lattice melting line and a vortex glass to vortex liquid line in the YBa2Cu3O7-delta single crystal. The critical scaling exponents for both systems are presented. A more complete (H-T) phase diagram, containing the upper critical field H-c2(T), the vortex-glass transition line H-g(T), and the magnetic irreversibility line H-irr(T) was established for bulk MgB2. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif San Diego, Inst Pure & Appl Phys Sci, La Jolla, CA 92093 USA. 4D Neuro Imaging, San Diego, CA 92121 USA. Univ Calif San Diego, Dept Mech & Aerosp Engn, La Jolla, CA 92093 USA. Los Alamos Natl Lab, MST, STC, Los Alamos, NM 87545 USA. RP Maple, MB (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. NR 9 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 132 EP 136 AR PII S0921-4534(02)01212-1 DI 10.1016/S0921-4534(02)01212-1 PG 5 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700027 ER PT J AU Kwok, WK Olsson, RJ Karapetrov, G Welp, U Vlasko-Vlasov, V Kadowaki, K Crabtree, GW AF Kwok, WK Olsson, RJ Karapetrov, G Welp, U Vlasko-Vlasov, V Kadowaki, K Crabtree, GW TI Modification of vortex behavior through heavy ion lithography SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 10th US-Japan Workshop on High T(c) Superonductors CY DEC 02-05, 2001 CL SANTA FE, NEW MEXICO SP Los Alamos Lab, Superconductiv Technol Ctr DE YBCO; Bi-2212; columnar defects; vortex pinning ID CRYSTALS; YBA2CU3O7-DELTA AB Columnar defects induced by high-energy heavy ion irradiation constitute one of the most effective vortex pinning sites in high temperature superconductors. We demonstrate a novel method of effectively patterning vortex pinning sites in single crystals of the high temperature superconductors YBa2Cu3O7-d and Bi2Sr2CaCu2Ox using heavy ion irradiation. These patterns include linear channels, a lattice of squares, and asymmetric pinning gradient sites where vortices can either flow unimpeded or are trapped in spatially periodic arrangements. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Tsukuba, Inst Mat Sci, Tsukuba, Ibaraki 3058573, Japan. RP Kwok, WK (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Karapetrov, Goran/C-2840-2008 OI Karapetrov, Goran/0000-0003-1113-0137 NR 10 TC 53 Z9 53 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 2002 VL 382 IS 1 BP 137 EP 141 AR PII S0921-4534(02)01213-2 DI 10.1016/S0921-4534(02)01213-3 PG 5 WC Physics, Applied SC Physics GA 617HR UT WOS:000179356700028 ER PT J AU Antonov, VN Harmon, BN Yaresko, AN AF Antonov, VN Harmon, BN Yaresko, AN TI Electronic structure of mixed-valence semiconductors in the LSDA+U approximation. II. SmB6 and YbB12 SO PHYSICAL REVIEW B LA English DT Article ID RARE-EARTH HEXABORIDES; KONDO INSULATOR YBB12; NEUTRON-SCATTERING; PHYSICAL-PROPERTIES; SINGLE-CRYSTAL; GAP-STATE; SPECTROSCOPY; EXCITATION; SPECTRA; METALS AB The electronic structure and optical spectra of SmB6 and YbB12 are investigated theoretically from first principles, using the fully relativistic Dirac LMTO band structure method. The electronic structure is obtained with the local spin-density approximation (LSDA), as well as with the so-called LSDA+U approach. The energy band structures of SmB6 and YbB12 are related to their measured XPS and UPS spectra as well as optical spectra. The LSDA+U band structure calculations produce a small hybridization energy gap in SmB6 and YbB12 for samarium and ytterbium ions in the divalent state. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Max Planck Inst CPFS, D-01187 Dresden, Germany. Kiev Met Phys Inst, UA-252142 Kiev, Ukraine. RP Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 55 TC 55 Z9 57 U1 1 U2 17 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 OCT 15 PY 2002 VL 66 IS 16 AR 165209 DI 10.1103/PhysRevB.66.165209 PG 9 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400064 ER PT J AU Antonov, VN Harmon, BN Yaresko, AN AF Antonov, VN Harmon, BN Yaresko, AN TI Electronic structure of mixed-valence semiconductors in the LSDA+U approximation. I. Sm monochalcogenides SO PHYSICAL REVIEW B LA English DT Article ID METAL-INSULATOR-TRANSITION; INTERMEDIATE-VALENCE; SAMARIUM SULFIDE; HIGH-PRESSURE; BAND THEORY; HYBRIDIZATION GAP; GOLDEN SMS; DENSITY; STATE; SYSTEMS AB The electronic structure and optical spectra of Sm monochalcogenides are investigated theoretically from first principles, using the fully relativistic Dirac LMTO band structure method. The electronic structure is obtained with the local spin-density approximation (LSDA), as well as with the so-called LSDA+U approach. In contrast to LSDA, where the stable solution in SmS is a metal, the LSDA+U gave an insulating ground state. The energy band structure of samarium monochalcogenides describes well their measured x-ray photoemission spectra (XPS) as well as their optical spectra. The electronic structure of SmS high-pressure golden phase calculated in the LSDA+U approximation is characterized by five fully occupied 4f levels situated around 6 eV below the Fermi level and a sixth 4f level partly occupied due to pinning at the Fermi level. The occupation number is equal to 0.45 (valence 2.55+). C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Max Planck Inst CPFS, D-01187 Dresden, Germany. Kiev Met Phys Inst, UA-252142 Kiev, Ukraine. RP Antonov, VN (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 74 TC 63 Z9 63 U1 3 U2 20 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 OCT 15 PY 2002 VL 66 IS 16 AR 165208 DI 10.1103/PhysRevB.66.165208 PG 10 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400063 ER PT J AU Armiento, R Mattsson, AE AF Armiento, R Mattsson, AE TI Subsystem functionals in density-functional theory: Investigating the exchange energy per particle SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; ELECTRON-GAS; POTENTIAL APPROXIMATION; METALLIC SURFACE; EXPANSION; MOLECULES; FORMALISM; ACCURATE; SOLIDS; STATE AB A viable way of extending the successful use of density-functional theory into studies of even more complex systems than are addressed today has been suggested by Kohn and Mattsson [W. Kohn and A. E. Mattsson, Phys. Rev. Lett. 81, 3487 (1998); A. E. Mattsson and W. Kohn, J. Chem. Phys. 115, 3441 (2001)], and is further developed in this work. The scheme consists of dividing a system into subsystems and applying different approximations for the unknown (but general) exchange-correlation energy functional to the different subsystems. We discuss a basic requirement on approximative functionals used in this scheme; they must all adhere to a single explicit choice of the exchange-correlation energy per particle. From a numerical study of a model system with a cosine effective potential, the Mathieu gas, and one of its limiting cases, the harmonic oscillator model, we show that the conventional definition of the exchange energy per particle cannot be described by an analytical series expansion in the limit of slowly varying densities. This indicates that the conventional definition is not suitable in the context of subsystem functionals. We suggest alternative definitions and approaches to subsystem functionals for slowly varying densities and discuss the implications of our findings on the future of functional development. C1 Stockholm Ctr Phys Astron & Biotechnol, Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden. Sandia Natl Labs, Surface & Interface Sci Dept MS 1415, Albuquerque, NM 87185 USA. RP Stockholm Ctr Phys Astron & Biotechnol, Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden. EM rar@theophys.kth.se; aematts@sandia.gov RI Armiento, Rickard/E-1413-2011 OI Armiento, Rickard/0000-0002-5571-0814 NR 41 TC 43 Z9 43 U1 0 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 OCT 15 PY 2002 VL 66 IS 16 AR 165117 DI 10.1103/PhysRevB.66.165117 PG 17 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400053 ER PT J AU Controzzi, D Essler, FHL AF Controzzi, D Essler, FHL TI Dynamical density correlation function of one-dimensional Mott insulators in a magnetic field SO PHYSICAL REVIEW B LA English DT Article ID ATTRACTIVE HUBBARD-MODEL; PEIERLS-DISTORTED CHAIN; EXACT FORM-FACTORS; OPTICAL-ABSORPTION; SCATTERING MATRIX; SCALING LIMIT; GORDON MODEL; CONDUCTIVITY; SEPARATION; ELECTRONS AB We consider the one-dimensional extended Hubbard model at half filling in the presence of a magnetic field. Using field theory techniques we calculate the dynamical density-density correlation function chi(nn)(omega,q) in the low-energy limit. When excitons are formed, a singularity appears in chi(nn)(omega,q) at a particular energy and momentum transfer. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NR 49 TC 11 Z9 11 U1 1 U2 5 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 OCT 15 PY 2002 VL 66 IS 16 AR 165112 DI 10.1103/PhysRevB.66.165112 PG 7 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400048 ER PT J AU Fournee, V Ross, AR Lograsso, TA Anderegg, JW Dong, C Kramer, M Fisher, IR Canfield, PC Thiel, PA AF Fournee, V Ross, AR Lograsso, TA Anderegg, JW Dong, C Kramer, M Fisher, IR Canfield, PC Thiel, PA TI Surface structures of approximant phases in the Al-Pd-Mn system SO PHYSICAL REVIEW B LA English DT Article ID QUASI-CRYSTALLINE APPROXIMANT; TEMPERATURE; AL70PD21MN9; DEFECTS; ORDER AB We present a study of the surface of the xi'-Al-Pd-Mn approximant phase based upon scanning tunneling microscopy and low-energy electron diffraction. Several structures are observed on two different samples grown either by the Bridgman technique or by a self-flux method, and which contain various degrees of disorder. We also describe some other complex crystalline phases that are sometimes observed on the fivefold surface of Al-Pd-Mn quasicrystalline samples after the sputter-annealing cleaning process under ultrahigh vacuum conditions. This includes the T approximant phase resulting from surface decomposition after a high-temperature annealing. C1 Iowa State Univ, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Dept Chem, Ames, IA 50011 USA. RP Iowa State Univ, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. EM thiel@ameslab.gov RI Canfield, Paul/H-2698-2014 NR 25 TC 27 Z9 27 U1 0 U2 0 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 OCT 15 PY 2002 VL 66 IS 16 AR 165423 DI 10.1103/PhysRevB.66.165423 PG 10 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400133 ER PT J AU Frank, S Wedler, H Behm, RJ Rottler, J Maass, P Caspersen, KJ Stoldt, CR Thiel, PA Evans, JW AF Frank, S Wedler, H Behm, RJ Rottler, J Maass, P Caspersen, KJ Stoldt, CR Thiel, PA Evans, JW TI Approaching the low-temperature limit in nucleation and two-dimensional growth of fcc (100) metal films Ag/Ag(100) SO PHYSICAL REVIEW B LA English DT Article ID SUBMONOLAYER EPITAXIAL-GROWTH; ISLAND-SIZE DISTRIBUTIONS; HOMOEPITAXIAL GROWTH; DIFFUSION; DEPOSITION; SURFACES; AG(100); COALESCENCE; MORPHOLOGY; DENSITIES AB We analyze the formation of two-dimensional Ag islands following deposition of about 0.1 ML of Ag on Ag(100) over a temperature regime ranging from classical nucleation and growth behavior to almost immobile adatoms, from 300 to 125 K. Particular emphasis is placed on the post-deposition dynamics at the lower end of the temperature range, where the saturation island density is not reached at the end of the deposition, and nucleation and aggregation processes continue with adatoms from the remaining adatom gas. Our analysis combines VT scanning tunneling microscopy experiments with kinetic Monte Carlo simulation of appropriate atomistic models. The only adjustable parameters in the model are the terrace diffusion barrier and prefactor, which can be determined from island density behavior near room temperature. Other processes such as rapid edge diffusion, and "easy" nucleation and aggregation of diagonally adjacent adatoms, are treated as instantaneous. The model excellently reproduces all aspects of behavior at low temperatures, demonstrating that nucleation and growth processes can be described in one consistent scheme, down to the regime of almost immobile adatoms. C1 Univ Ulm, Abt Oberflachenchem & Katalyse, D-89069 Ulm, Germany. Univ Konstanz, Fachbereich Phys, D-78457 Constance, Germany. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Frank, S (reprint author), Univ Ulm, Abt Elektrochem, D-89069 Ulm, Germany. RI Maass, Philipp/H-1477-2011; Rottler, Joerg/L-5539-2013 OI Rottler, Joerg/0000-0002-5273-7480 NR 35 TC 16 Z9 17 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 155435 DI 10.1103/PhysRevB.66.155435 PG 7 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800154 ER PT J AU Grobis, M Lu, X Crommie, MF AF Grobis, M Lu, X Crommie, MF TI Local electronic properties of a molecular monolayer: C-60 on Ag(001) SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; THIN-FILMS; SURFACE; RECONSTRUCTION; TEMPERATURE; ADSORPTION; TRANSITION; GROWTH; C60 AB We have spatially resolved the local electronic structure of a C-60 monolayer on Ag(001) using scanning tunneling spectroscopy at T=7 K. Our measurements resolve four band states derived from C-60 highest occupied molecular orbital, lowest unoccupied molecular orbital (LUMO), and LUMO+1. We observe spatial inhomogeneity in the energy-resolved local density of states, which reflects C-60 internal structure. In addition, we are able to resolve the molecular orientation of coexisting bright and dim C-60 molecules in the monolayer. This combination of topographic and spectroscopic measurements provides further evidence that the appearance of bright and dim molecules originates from a Ag surface reconstruction. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Grobis, M (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Lu, Xinghua/F-2655-2010 NR 26 TC 77 Z9 78 U1 1 U2 21 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 16 AR 161408 DI 10.1103/PhysRevB.66.161408 PG 4 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400034 ER PT J AU Han, SH Ji, N Belkin, MA Shen, YR AF Han, SH Ji, N Belkin, MA Shen, YR TI Sum-frequency spectroscopy of electronic resonances on a chiral surface monolayer of bi-naphthol SO PHYSICAL REVIEW B LA English DT Article ID CIRCULAR-DICHROISM SPECTROSCOPY; 2ND-HARMONIC GENERATION; NONLINEAR OPTICS; INTERFACES; LIQUIDS AB We study chiral response in optical sum-frequency generation near electronic resonances from a 1,1'-bi-2-naphthol (BN) monolayer adsorbed on water. The polarization dependence of the spectra indicates that the molecules are well oriented at the surface with their symmetry axis along the surface normal. Orientational ordering effectively enhances the chiral response per BN molecule. The results can be quantitatively understood with a simple coupled-oscillator model for BN. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Han, SH (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Belkin, Mikhail/E-9041-2013 OI Belkin, Mikhail/0000-0003-3172-9462 NR 15 TC 31 Z9 31 U1 2 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 16 AR 165415 DI 10.1103/PhysRevB.66.165415 PG 6 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400125 ER PT J AU Hurley, DH Telschow, KL AF Hurley, DH Telschow, KL TI Picosecond surface acoustic waves using a suboptical wavelength absorption grating SO PHYSICAL REVIEW B LA English DT Article ID GRID POLARIZER; ULTRASONICS; GENERATION; ELECTRON; PULSES; METALS; GOLD AB We have demonstrated laser generation and detection of Rayleigh surface acoustic waves (SAW's) with acoustic wavelengths that are smaller than the optical wavelength of both the excitation and the detection beams. SAW generation was achieved using electron beam lithography to modulate the surface reflectivity and hence the lateral thermal gradients on a suboptical wavelength scale. The generation and detection characteristics of two material systems were investigated (aluminum absorption gratings on Si and GaAs substrates). The polarization sensitive absorption characteristics of the suboptical wavelength lithographic grating were exploited in order to explore various acoustic generation and detection schemes. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Hurley, DH (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 18 TC 32 Z9 32 U1 1 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 153301 DI 10.1103/PhysRevB.66.153301 PG 4 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800010 ER PT J AU Jia, JF Liu, X Wang, JZ Li, JL Wang, XS Xue, QK Li, ZQ Zhang, ZY Zhang, SB AF Jia, JF Liu, X Wang, JZ Li, JL Wang, XS Xue, QK Li, ZQ Zhang, ZY Zhang, SB TI Fabrication and structural analysis of Al, Ga, and In nanocluster crystals SO PHYSICAL REVIEW B LA English DT Article ID SCANNING TUNNELING MICROSCOPE; NANOCRYSTAL SUPERLATTICES; MAGIC CLUSTERS; SURFACE; SI(111); ARRAYS; ATOMS; RECONSTRUCTIONS; NANOSTRUCTURE; SILICON AB Artificial nanocluster crystals of In, Ga, and Al were fabricated using a technique in which surface mediated magic clustering is used to achieve identical cluster size while the Si(111)-7x7 surface is used as a template for ordering the clusters. The atomic structures, formation mechanism and stability of the nanoclusters were studied with in situ scanning tunneling microscopy combined with first-principles total energy calculations. Our study shows that delicate control of growth kinetics is extremely important for cluster crystal fabrication, and there is essentially no limitation to this method. The high thermal stability and unique structure make these artificial nanocluster crystals promising for various applications. C1 Chinese Acad Sci, Inst Phys, State Key Lab Surface Phys, Beijing 100080, Peoples R China. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Chinese Acad Sci, Inst Phys, State Key Lab Surface Phys, POB 603, Beijing 100080, Peoples R China. RI Krausnick, Jennifer/D-6291-2013; Wang, Xue-sen/G-2749-2012; Zhang, Shengbai/D-4885-2013 OI Wang, Xue-sen/0000-0002-5510-3002; Zhang, Shengbai/0000-0003-0833-5860 NR 46 TC 97 Z9 99 U1 2 U2 23 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 OCT 15 PY 2002 VL 66 IS 16 AR 165412 DI 10.1103/PhysRevB.66.165412 PG 10 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400122 ER PT J AU Liu, DJ Evans, JW AF Liu, DJ Evans, JW TI Sintering of two-dimensional nanoclusters in metal(100) homoepitaxial systems: Deviations from predictions of Mullins continuum theory SO PHYSICAL REVIEW B LA English DT Article ID FROM-EQUILIBRIUM NANOSTRUCTURES; 2-DIMENSIONAL ISLANDS; EPITAXIAL-GROWTH; SELF-DIFFUSION; EDGE DIFFUSION; SURFACES; RELAXATION; EVOLUTION; SHAPE; TEMPERATURE AB We present a comparison of the predictions of atomistic and continuum models for the sintering of pairs of near-square two-dimensional nanoclusters adsorbed on the (100) surface in fcc metal homoepitaxial systems. Mass transport underlying these processes is dominated by periphery diffusion (PD) of adatoms along the edge of the clusters. A Mullins-type continuum model for cluster evolution incorporates anisotropy in the step edge stiffness (reflecting the energetics and adsorption site lattice structure in the atomistic model), and can also account for anisotropy in the step edge mobility (reflecting details of the kinetics). In such continuum treatments, the characteristic time tau(eq) for relaxation of clusters with linear size of order L satisfies tau(eq)similar toL(4). Deviations may generally be expected for small sizes L or low temperatures T. However, for the relaxation of dumbbell-shaped clusters (formed by corner-to-corner coalescence of square clusters), atomistic simulations for PD with no kink rounding barrier (delta=0) reveal that tau(eq)similar toL(4) always applies. In contrast, atomistic simulations with a large kink rounding barrier (delta>0) reveal distinct scaling with tau(eq)similar toL(3), for low T or small L, thus providing an effective way to test for delta>0. For the relaxation of faceted rectangular clusters (formed by side-to-side coalescence of square clusters), atomistic simulations for PD with delta=0 reveal that tau(eq)similar toL(2), for low T or small L. This is consistent with a recent proposal by Combe and Larralde. For large delta>0, tau(eq) has an even weaker dependence on L. We elucidate scaling behavior and the effective activation barrier for relaxation in terms of the individual atomistic PD processes and their barriers. C1 Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. RP Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. NR 44 TC 35 Z9 35 U1 1 U2 5 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 OCT 15 PY 2002 VL 66 IS 16 AR 165407 DI 10.1103/PhysRevB.66.165407 PG 12 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400117 ER PT J AU Lyo, SK Huang, DH AF Lyo, SK Huang, DH TI Magnetoquantum oscillations of thermoelectric power in multisublevel quantum wires SO PHYSICAL REVIEW B LA English DT Article ID QUANTIZING MAGNETIC-FIELD; DIMENSIONAL ELECTRON-GAS; PHONON-DRAG THERMOPOWER; HETEROJUNCTIONS; MOBILITY; SEMICONDUCTOR; SCATTERING AB The electron-diffusion and phonon-drag thermoelectric power (TEP) is investigated in a quantum wire as a function of the temperature, perpendicular magnetic field, and the electron density in the regime, where the conductivity is limited by elastic scattering. The wire is narrow in the growth direction with only the ground sublevel populated but is wide in the other confinement direction providing several occupied sublevels at zero field. Magnetic field causes depopulation of these sublevels, yielding quantum oscillations of the TEP and the conductance. An anomalous, large positive electron-diffusion TEP is obtained when the Fermi level lies slightly above a sublevel other than the ground sublevel due to the van Hove singularity at the subband edge. In contrast to the power-law temperature (T) dependence in higher dimensions, the phonon-drag TEP is proportional to exp(-(h) over bar omega(F)/k(B)T) at low temperatures, where (h) over bar omega(F) is the threshold phonon energy with a wave number q(F) corresponding to the minimum momentum transfer for back scattering. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. AFRL, VSSS, Kirtland AFB, NM 87117 USA. RP Lyo, SK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 21 Z9 21 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 155307 DI 10.1103/PhysRevB.66.155307 PG 11 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800086 ER PT J AU Montano, PA Price, DL Macrander, AT Cooper, BR AF Montano, PA Price, DL Macrander, AT Cooper, BR TI Inelastic x-ray scattering from 6H-SiC SO PHYSICAL REVIEW B LA English DT Article ID AB-INITIO CALCULATIONS; BAND-STRUCTURE; BRILLOUIN-ZONE; DYNAMIC STRUCTURE; SILICON-CARBIDE; SPECIAL POINTS; METAL; SEMICONDUCTORS; PERFORMANCE; INSULATORS AB We performed theoretical calculations of the dynamical structure factor S(q,omega), using a linearized combination of muffin-tin orbitals in the self-consistent expression of Ehrenreich and Cohen, equivalent to the random-phase approximation. We compare the calculations to our previously reported inelastic x-ray scattering (IXS) spectra. IXS spectra were obtained at momentum transfers q ranging from 0.47 to 2.00 Angstrom(-1) along the c axis and from 0.67 to 2.00 Angstrom(-1) along the a axes of the hexagonal structure. At small q, a clear peak corresponding to a plasmon for the valence band was observed. At large q the spectra broaden severely and there was a strong crystal lattice orientation dependence of the spectra. The basic calculations reproduce many features of all the observed spectra, but are not in complete agreement. The influence of a correction to the calculated Im epsilon(-1)(q,omega) to incorporate a "local-field factor" was investigated. The need for such a correction was first addressed by Hubbard. This factor is used to correct the exchange-correlation potential for screening and should increase with q. We applied a functional form consistent with the local-density approximation. The effect of this correction at large q is to broadly raise and lower-energy portions of S(q,omega), in worse agreement with the data. At low q it has almost no effect. We also explored the effect of including the off-diagonal elements of the dynamical dielectric matrix (albeit for 3C-SiC). This manner of correcting for local-field effects, i.e., screening corrections for crystal orientation, has been reported to be quite important for semiconductors, and we confirm this finding. The inclusion of the off-diagonal terms had a substantial effect upon the detailed nature of the structure factor so as to improve agreement. In general, our conclusions are in keeping with reports for metals, in that the two types of screening corrections have opposite effects and somewhat cancel. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. US DOE, Germantown, MD 20974 USA. Univ Illinois, Dept Phys, Chicago, IL 60680 USA. Univ Memphis, Dept Phys, Memphis, TN 38152 USA. RP Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. EM atm@aps.anl.gov RI Price, David Long/A-8468-2013 NR 41 TC 4 Z9 4 U1 0 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 OCT 15 PY 2002 VL 66 IS 16 AR 165218 DI 10.1103/PhysRevB.66.165218 PG 6 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400073 ER PT J AU Mozyrsky, D Fedichkin, L Gurvitz, SA Berman, GP AF Mozyrsky, D Fedichkin, L Gurvitz, SA Berman, GP TI Interference effects in resonant magnetotransport SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; MAGNETIC-RESONANCE; QUANTUM TRANSPORT; RATE-EQUATIONS; SILICON; HETEROSTRUCTURES; JUNCTIONS; MECHANISM; COMPUTER; SURFACES AB We study nonequilibrium magnetotransport through a single-electron transistor or an impurity. We find that due to spin-flip transitions, generated by the spin-orbit interaction, the spectral density of the tunneling current fluctuations develops a distinct peak at the frequency of Zeeman splitting. This mechanism explains modulation in the tunneling current at the Larmor frequency observed in scanning tunneling microscope experiments and can be utilized as a detector for single spin measurement. C1 Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Clarkson Univ, Dept Phys, Potsdam, NY 13699 USA. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. RP Mozyrsky, D (reprint author), Los Alamos Natl Lab, CNLS, T-13, Los Alamos, NM 87545 USA. NR 28 TC 54 Z9 54 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 16 AR 161313 DI 10.1103/PhysRevB.66.161313 PG 4 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400019 ER PT J AU Niklasson, AMN AF Niklasson, AMN TI Expansion algorithm for the density matrix SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; LINEAR SCALING COMPUTATION; FUNCTIONAL-THEORY; FOCK MATRIX; DIAGONALIZATION; MINIMIZATION; PURIFICATION; TRANSFORMS; PRINCIPLES; ATOMS AB A purification algorithm for expanding the single-particle density matrix in terms of the Hamiltonian operator is proposed. The scheme works with a predefined occupation and requires less than half the number of matrix-matrix multiplications compared to existing methods at low (<10%) and high (>90%) occupancies. The expansion can be used with a fixed chemical potential, in which case it is an asymmetric generalization of and a substantial improvement over grand canonical McWeeny purification. It is shown that the computational complexity, measured as the number of matrix multiplications, essentially is independent of system size even for metallic materials with a vanishing band gap. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Niklasson, AMN (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 31 TC 77 Z9 77 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 155115 DI 10.1103/PhysRevB.66.155115 PG 6 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800054 ER PT J AU Niklasson, AMN Tymczak, CJ Roder, H AF Niklasson, AMN Tymczak, CJ Roder, H TI Multiresolution density-matrix approach to electronic structure calculations SO PHYSICAL REVIEW B LA English DT Article ID WAVELET BASES; PURIFICATION; TRANSFORMS; ALGORITHMS AB A multiresolution density-matrix wavelet approach to electronic-structure calculations is proposed. A separable multidimensional biorthogonal interpolating multiwavelet and scaling representation of the Hamiltonian operator is introduced in which individual operator elements can be calculated locally at any scale. Issues regarding this representation are discussed, such as its low complexity in higher dimensions and its direct relation to finite-difference schemes. The density matrix is calculated via polynomial expansions in terms of the Hamiltonian. The expansions are improvements of the McWeeny purification within a grand canonical ensemble and are shown to be up to 20% more efficient in the number of matrix-matrix multiplications. The efficiency of the multiresolution representation of the density matrix compared to a real-space representation is analyzed. Within the multiresolution wavelet representation it is shown how the sparsity of the density matrix is preserved for localized insulating systems as well as for itinerant metallic systems. This is not possible within a real-space representation of the density matrix which has a very slow decay of its elements in the metallic phase. This makes the multiresolution approach very attractable for linear- or close to linear-scaling electronic-structure calculations. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 29 TC 16 Z9 16 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 155120 DI 10.1103/PhysRevB.66.155120 PG 15 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800059 ER PT J AU Papa, E Tsvelik, AM AF Papa, E Tsvelik, AM TI Thermodynamics of double-layer quantum Hall systems SO PHYSICAL REVIEW B LA English DT Article ID SPONTANEOUS INTERLAYER COHERENCE; PHASE-TRANSITIONS; SINE-GORDON AB In this paper we apply the exact solution of the sine-Gordon model to describe thermodynamic properties of the soliton liquid in the incommensurate phase of the double-layer quantum Hall systems. In this way we include thermal fluctuations and extend to finite temperatures the results obtained by C. B. Hanna, A. H. MacDonald, and S. M. Girvin [Phys. Rev. B 63, 125305 (2001)]. In addition we calculate the specific heat of the system. While the results obtained for the sine-Gordon model are available in a temperature interval (0,T-c), where T-c=8pirho(s), rho(s) the pseudospin stiffness, they can be applied in the bilayer system up to temperatures 3 T-BKT, where T-BKT=pirho(s)/2 is the vortex-mediated Berezinskii-Kosterlitz-Thouless transition temperature. Above this temperature the operators cos betaPhi and cos(2piTheta/beta) are both relevant and the system is in a phase with coexisting order parameters. Theta is the dual field of Phi and beta is the sine-Gordon coupling constant. We provide numerical estimates for thermodynamic quantities for the range of parameters relevant for GaAs. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Papa, E (reprint author), Univ Texas, Dept Phys, Austin, TX 78712 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 155304 DI 10.1103/PhysRevB.66.155304 PG 6 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800083 ER PT J AU Rhee, JY Harmon, BN AF Rhee, JY Harmon, BN TI Optical properties of RNi2B2C (R =Y and Lu) SO PHYSICAL REVIEW B LA English DT Article ID NICKEL BORIDE CARBIDES; SUPERCONDUCTING LUNI2B2C; YNI2B2C AB The electronic structures and optical conductivity spectra of RNi2B2C (R=Y and Lu) were calculated using a tight-binding linear-muffin-tin-orbital method within the atomic-sphere approximation. The calculated optical conductivity spectra agree reasonably well with the experimental ones. Unlike suggestions based on earlier experimental results, a strong optical anisotropy is obtained. Detailed information on the observed interband-absorption features is presented. C1 Hoseo Univ, Dept Phys, Asan 336795, Choongnam, South Korea. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Rhee, JY (reprint author), Hoseo Univ, Dept Phys, Asan 336795, Choongnam, South Korea. RI Rhee, Joo/D-2987-2011 NR 21 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 15 AR 153102 DI 10.1103/PhysRevB.66.153102 PG 4 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800002 ER PT J AU Wang, LG Zunger, A AF Wang, LG Zunger, A TI Phosphorus and sulphur doping of diamond SO PHYSICAL REVIEW B LA English DT Article ID N-TYPE DIAMOND; COHERENT PHASE-DIAGRAMS; III-V SEMICONDUCTORS; AB-INITIO; TOTAL-ENERGY; THIN-FILMS; SULFUR; SOLIDS; DONOR; IMPURITIES AB Previous calculations on n-type doping of diamond by P and S predicted that S has a shallower level and a higher solubility than P. Our first-principles calculations show that the opposite is true: Phosphorus impurity in diamond gives rise to a shallower donor level, and has a higher bulk solid solubility than sulphur. This agrees with the trends expected from the strength of the atomic pseudopotentials. We predict that coherent epitaxial expansion would substantially increase the solubility of P, and that complex formation of P with H is exothermic, also leading to passivation of the P donor action; removal of H then is needed to achieve good n-type characteristicy. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wang, LG (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 37 TC 59 Z9 59 U1 3 U2 23 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 16 AR 161202 DI 10.1103/PhysRevB.66.161202 PG 4 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400006 ER PT J AU Wei, SH Zhang, SB AF Wei, SH Zhang, SB TI Chemical trends of defect formation and doping limit in II-VI semiconductors: The case of CdTe SO PHYSICAL REVIEW B LA English DT Article ID BAND-GAP SEMICONDUCTORS; MOLECULAR-BEAM EPITAXY; FILM SOLAR-CELLS; ELECTRONIC-STRUCTURE; ALXGA1-XAS ALLOYS; INTERSTITIAL ZINC; NATIVE DEFECTS; DX CENTERS; N-TYPE; GAAS AB Using first-principles band structure methods we studied the general chemical trends of defect formation in II-VI semiconductors. We systematically calculated the formation energies and transition energy levels of intrinsic and extrinsic defects and defect complexes in the prototype CdTe and investigated the limiting factors for p-type and n-type doping in this material. Possible approaches to significantly increase the doping limits are discussed. Our general understanding of the chemical trends of defect formation energies and transition energy levels in CdTe is expected to be applicable also to other II-VI semiconductors. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 50 TC 296 Z9 300 U1 9 U2 107 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 OCT 15 PY 2002 VL 66 IS 15 AR 155211 DI 10.1103/PhysRevB.66.155211 PG 10 WC Physics, Condensed Matter SC Physics GA 612MV UT WOS:000179080800076 ER PT J AU Yang, YX VanMil, B Muratov, L Cooper, BR Myers, TH Wills, JM AF Yang, YX VanMil, B Muratov, L Cooper, BR Myers, TH Wills, JM TI Effect on chlorine incorporation as Mg is alloyed into ZnSe SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-BEAM EPITAXY; SURFACE ELECTRONIC-STRUCTURE; NATIVE-DEFECT COMPLEXES; CL-DOPED ZNSE; SEMICONDUCTORS; COMPENSATION; SYSTEMS; ZNMGSE; BAND AB We have investigated chlorine incorporation in ZnSe and Zn(x)Mg(1-x)Se through both modeling and experiment. Solubility issues, native defects and chlorine-impurity-related defects have been studied using the ab initio full potential linear muffin-tin-orbital method. Our calculations indicate that the addition of Mg reduces the formation energy for chlorine on the Se site, thereby predicting increased solubility. Subsequent chlorine doping experiments in Zn(x)Mg(1-x)Se using molecular beam epitaxy indicated significantly higher chlorine incorporation in the presence of magnesium, directly supporting the prediction of the calculations. Calculations support the strong tendency for the formation of a defect complex between a chlorine impurity at the Se site and a vacancy at the neighboring Zn site for heavy n-type doping. The formation of this defect serves to compensate, i.e., negate, the chlorine as an n-type dopant. Experimental observations indicated that significant compensation occurs for heavy Cl doping. There are competing mechanisms that contribute to the effect of magnesium on chlorine when used as an n-type dopant in ZnSe. First, the formation energies for chlorine substituting for selenium decrease in the presence of magnesium. Second, the formation energies of the Cl(Se)-V(Zn) complex also decrease. Finally, the band gap increases in the presence of magnesium, decreasing the net electron concentration at room temperature. Thus, the net effect of adding magnesium is to decrease the maximum achievable carrier concentration through the use of chlorine as an n-type dopant. C1 W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. RP Yang, YX (reprint author), W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RI Myers, Thomas/C-3769-2013 NR 35 TC 2 Z9 2 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2002 VL 66 IS 16 AR 165222 DI 10.1103/PhysRevB.66.165222 PG 9 WC Physics, Condensed Matter SC Physics GA 616DL UT WOS:000179286400077 ER PT J AU Bern, Z De Freitas, A Dixon, L Wong, HL AF Bern, Z De Freitas, A Dixon, L Wong, HL TI Supersymmetric regularization, two-loop QCD amplitudes, and coupling shifts SO PHYSICAL REVIEW D LA English DT Review ID 2-LOOP MASTER INTEGRALS; BACKGROUND FIELD METHOD; ABELIAN GAUGE-THEORIES; YANG-MILLS THEORY; LIGHT-LIKE LEGS; HELICITY AMPLITUDES; BETA-FUNCTION; DIMENSIONAL REDUCTION; GLUON SCATTERING; GAMMA-ASTERISK->3 JETS AB We present a definition of the four-dimensional helicity (FDH) regularization scheme valid for two or more loops. This scheme was previously defined and utilized at one loop. It amounts to a variation on the standard 't Hooft-Veltman scheme and is designed to be compatible with the use of helicity states for "observed" particles. It is similar to dimensional reduction in that it maintains an equal number of bosonic and fermionic states, as required for preserving supersymmetry. Supersymmetry Ward identities relate different helicity amplitudes in supersymmetric theories. As a check that the FDH scheme preserves supersymmetry, at least through two loops, we explicitly verify a number of these identities for gluon-gluon scattering (gg-->gg) in supersymmetric QCD. These results also cross-check recent nontrivial two-loop calculations in ordinary QCD. Finally, we compute the two-loop shift between the FDH coupling and the standard modified minimal subtraction ((MS) over bar) scheme coupling, alpha(s). The FDH shift is identical to the one for dimensional reduction. The two-loop coupling shifts are then used to obtain the three-loop QCD beta function in the FDH and dimensional reduction schemes. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Bern, Z (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NR 107 TC 131 Z9 131 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 OCT 15 PY 2002 VL 66 IS 8 AR 085002 DI 10.1103/PhysRevD.66.085002 PG 25 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 612NC UT WOS:000179081500054 ER PT J AU Giudice, GF Kolb, EW Lesgourgues, J Riotto, A AF Giudice, GF Kolb, EW Lesgourgues, J Riotto, A TI Transdimensional physics and inflation SO PHYSICAL REVIEW D LA English DT Article ID COSMOLOGICAL PERTURBATIONS; BRANE-WORLD; GRAVITATIONAL-WAVES; PLANCKIAN PHYSICS; EVOLUTION; SPECTRUM; MODELS; STABILIZATION; DIMENSIONS; MILLIMETER AB Within the framework of a five-dimensional brane world with a stabilized radion, we compute the cosmological perturbations generated during inflation and show that the perturbations are a powerful tool to probe the physics of extra dimensions. While we find that the power spectrum of scalar perturbations is unchanged, we show that the existence of the fifth dimension is imprinted on the spectrum of gravitational waves generated during inflation. In particular, we find that the tensor perturbations receive a correction proportional to (HR)(2), where H is the Hubble expansion rate during inflation and R is the size of the extra dimension. We also generalize our findings to the case of several extra dimensions as well as to warped geometries. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Fermilab Natl Accelerator Lab, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. LAPTH, F-74941 Annecy Le Vieux, France. RP CERN, Div Theory, CH-1211 Geneva 23, Switzerland. NR 55 TC 26 Z9 26 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 2002 VL 66 IS 8 AR 083512 DI 10.1103/PhysRevD.66.083512 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 612NC UT WOS:000179081500022 ER PT J AU Wilson, JR AF Wilson, JR TI Precompression of colliding neutron stars SO PHYSICAL REVIEW D LA English DT Article ID HEAD-ON COLLISION; COLLAPSE AB Numerical calculations of the head-on collision of two neutron stars are made using the full Einstein equations. The density of the stars is found to rise well before the stars collide. For comparision, calculations are also made with the spatial part of the metric constrained to be conformally flat. This calculation gives rise to nearly the same compression as the calculation made with the full proper metric. Previously the same type of stellar compression was obtained in neutron star binary hydrodynamic calculations which assumed conformally flat space. As such, this effect is not dependent upon the rotational motion of the stars and is more general. These results lend credence to the compression observed in the simulations of binary neutron stars for which a conformally flat spatial metric was assumed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wilson, JR (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM jimwilson@llnl.gov NR 8 TC 4 Z9 4 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 EI 1550-2368 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 2002 VL 66 IS 8 AR 084015 DI 10.1103/PhysRevD.66.084015 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 612NC UT WOS:000179081500041 ER PT J AU Boyle, TJ Andrews, NL Alam, TM Rodriguez, MA Santana, JM Scott, BL AF Boyle, TJ Andrews, NL Alam, TM Rodriguez, MA Santana, JM Scott, BL TI Crystallographic characterization of the esterification pathway of Group V alkoxides SO POLYHEDRON LA English DT Article DE metal alkoxides; esterification; single-crystal X-ray; Group V; tantalum; niobium ID X-RAY STRUCTURES; TITANIUM(IV) NEOPENTOXIDES; CARBOXYLIC-ACID; METAL ALKOXIDES; PRECURSORS; CLUSTER AB The products isolated from the stoichiometric reaction mixtures of [M(mu-OEt)(ONeP)(4)](2) where M = Nb (1) or Ta (2) and ONep = OCH2CMe3, and a series of sterically demanding carboxylic acids (HORc where ORc = O2CCMe3 (OBc) or O2CCH2CMe3 (ONc)) led to the isolation and characterization of a new family of compounds at varied degrees of esterification. The number of oxo ligands formed from the esterification pathway was found to be dictated by the temperature of the reaction mixture, as well as the steric bulk of the carboxylate ligand. For the Nb systems, independent of the temperature of the reaction, [Nb(mu-OBc)(ONeP)(3)](2)(mu-O) (3) and [Nb-2(mu-O)(2)(mu-ONc)(2)(ONeP)(4)](2) (4) were isolated. For the room temperature reactions of the Ta systems, [Ta(mu-OBc)(ONeP)(3)](2)(mu-O) (5) and [Ta(mu-ONc)(ONep)(4)](2) (6) were formed but upon heating, [Ta-2(mu-O)(2)(mu-OBc)(2)(ONeP)(4)](2) (7) and [Ta(mu-ONc)(ONeP)(3)](2)(mu-O) (8) were isolated. [Ta-2(mu-O)(2)(mu-ONc)(2)(ONeP)(4)](2) (9) was also identified from a concentrated heated reaction mixture of 2 and HONc. The arrangements observed for 3, 5, 6, and 8 were dinuclear symmetric structures, wherein each metal was isolated in an octahedral (Oh) geometry with bridging ORc ligands. For 3, 5, and 8, an oxo ligand bridges the two metal centers which was not observed for 6. For 4, 7, and 9 the general structure consists of two "M-2(mu-O)(2)(mu-ORc)(2)(ONep)(4)" moieties that are linked by oxo ligands forming an [M-O](4) eight-member ring as the central core. Each Oh bound metal center possesses two bridging ORc and two terminal ONep ligands. Compounds 3-8 were further characterized by solid-state MAS NMR wherein the bulk powders are in agreement with the single crystal structures. Solution NMR studies indicated that the solid-state arrangements are retained in solution. Combined, the structural information garnered from these compounds define the step-wise esterification mechanism of Group V metal alkoxides. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. Los Alamos Natl Lab, Chem Sci & Technol Div, Xray Diffract Lab, Los Alamos, NM 87545 USA. RP Boyle, TJ (reprint author), Sandia Natl Labs, Adv Mat Lab, Suite 100,1001 Univ Blvd SE, Albuquerque, NM 87106 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 24 TC 12 Z9 12 U1 1 U2 7 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 OCT 15 PY 2002 VL 21 IS 23 BP 2333 EP 2345 AR PII S0277-5387(02)01186-5 DI 10.1016/S0277-5387(02)01186-5 PG 13 WC Chemistry, Inorganic & Nuclear; Crystallography SC Chemistry; Crystallography GA 606NF UT WOS:000178739500002 ER PT J AU Ritort, F Bustamante, C Tinoco, I AF Ritort, F Bustamante, C Tinoco, I TI A two-state kinetic model for the unfolding of single molecules by mechanical force SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID FREE-ENERGY DIFFERENCES; DNA-MOLECULES; ADHESION; STRENGTH; SYSTEMS AB We investigate the work dissipated during the irreversible unfolding of single molecules by mechanical force, using the simplest model necessary to represent experimental data. The model consists of two levels (folded and unfolded states) separated by an intermediate barrier. We compute the probability distribution for the dissipated work and give analytical expressions for the average and variance of the distribution. To first order, the amount of dissipated work is directly proportional to the rate of application of force (the loading rate) and to the relaxation time of the molecule. The model yields estimates for parameters that characterize the unfolding kinetics under force in agreement with those obtained in recent experimental results. We obtain a general equation for the minimum number of repeated experiments needed to obtain an equilibrium free energy, to within k(B)T, from nonequilibrium experiments by using the Jarzynski formula. The number of irreversible experiments grows exponentially with the ratio of the average dissipated work, (W-dis) over bar to k(B)T. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Barcelona, Dept Phys, E-08028 Barcelona, Spain. Univ Calif Berkeley, Howard Hughes Med Inst, Dept Phys & Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Tinoco, I (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM 10840, GM 32543, R01 GM010840, R01 GM010840-43, R01 GM010840-44, R01 GM032543, R37 GM010840, R37 GM032543] NR 21 TC 90 Z9 90 U1 0 U2 9 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 15 PY 2002 VL 99 IS 21 BP 13544 EP 13548 DI 10.1073/pnas.172525099 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 604RW UT WOS:000178635700038 PM 12374867 ER PT J AU Tian, Y Womack, M Molian, P Lo, CCH Anderegg, JW Russell, AM AF Tian, Y Womack, M Molian, P Lo, CCH Anderegg, JW Russell, AM TI Microstructure and nanomechanical properties of Al-Mg-B-Ti films synthesized by pulsed laser deposition SO THIN SOLID FILMS LA English DT Article DE Al-Mg-B-Ti film; pulsed laser deposition; structural properties; hardness ID ELECTRONIC-PROPERTIES; BORON AB Thin films were deposited from an ultra-hard, nanocomposite AlMgB14/TiB2 target on Si (1 0 0) by nanosecond (ns) and femtosecond (fs) pulsed laser deposition (PLD) techniques. X-ray diffraction and transmission electron microscopy were used to determine the film structure; scanning electron microscopy was employed to characterize the film surface topography; and X-ray photoelectron spectroscopy was performed to examine the film compositions and chemical bonding states of constituents. The mechanical properties of thin films such as hardness and elastic modulus were determined by nanoindentation tests. Results showed that the as-deposited films were amorphous, possessing a complex oxide glass structure, and this structure was stable up to 1223 K. The preferential reaction of Al, Mg and B with O inhibits the formation of crystalline AlMgB14. The absence of B-B bonds and nanocrystalline structure leads to nanohardness values for as-deposited films as low as approximately 10 GPa. The intrinsic hardness of the film could not be evaluated exactly because of surface roughness and substrate effects. It was found that the density of particulates in the films was drastically reduced by the use of a fs-pulsed laser source, suggesting that fs-PLD is a potential method for decreasing surface roughness. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Tian, Y (reprint author), Iowa State Univ, Dept Mat Sci & Engn, 3053 Gilman Hall, Ames, IA 50011 USA. OI Russell, Alan/0000-0001-5264-0104 NR 17 TC 25 Z9 26 U1 0 U2 13 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 OCT 15 PY 2002 VL 418 IS 2 BP 129 EP 135 AR PII S0040-6090(02)00766-6 DI 10.1016/S0040-6090(02)00766-6 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 611BY UT WOS:000178997600009 ER PT J AU Hsueh, CH AF Hsueh, CH TI Thermal stresses in elastic multilayer systems SO THIN SOLID FILMS LA English DT Article DE multilayers; stress; elastic properties; gallium arsenide ID RESIDUAL-STRESSES; THIN-FILMS; LAYERS; SUBSTRATE; SILICON; GAAS; ALAS AB Thermal stresses in elastic multilayer systems have been previously modelled. However, because the displacement compatibility condition at interfaces between layers must be satisfied, the complexity in obtaining a closed-form solution increases with the number of layers in the system. As a result, existing analyses often adopt simplifications (e.g. assuming a constant elastic modulus throughout the system) to obtain closed-form solutions or are solved numerically by computer. The present study develops an analytical model, in which the complexity in obtaining a closed-form solution is independent of the number of layers and an exact closed-form solution can be concisely formulated. Specific results are calculated for elastic thermal stresses in (AlGa)As laser diodes, which consist of five layers. Also, the zero-order and the first-order approximations are formulated based on the exact closed-form solution, and their accuracy is examined. The acceptability of assuming a constant elastic modulus in the system in existing analyses is also discussed. (C) 2002 Elsevier Science B.V All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hsueh, CH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 27 TC 132 Z9 146 U1 5 U2 37 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 OCT 15 PY 2002 VL 418 IS 2 BP 182 EP 188 AR PII S0040-6090(02)00699-5 DI 10.1016/S0040-6090(02)00699-5 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 611BY UT WOS:000178997600017 ER PT J AU Chambers, SA Wang, CM Thevuthasan, S Droubay, T McCready, DE Lea, AS Shutthanandan, V Windisch, CF AF Chambers, SA Wang, CM Thevuthasan, S Droubay, T McCready, DE Lea, AS Shutthanandan, V Windisch, CF TI Epitaxial growth and properties of MBE-grown ferromagnetic Co-doped TiO2 anatase films on SrTiO3(001) and LaAlO3(001) SO THIN SOLID FILMS LA English DT Article DE magnetic properties and measurements; molecular beam epitaxy (MBE); semiconductors; titanium oxide ID MOLECULAR-BEAM EPITAXY; ELECTRICAL SPIN INJECTION; PHASE-TRANSFORMATION; RUTILE FILMS; SEMICONDUCTORS; SPECTROSCOPY; SPINTRONICS; NBXTI1-XO2; TIO2(110); INTERFACE AB We have investigated the heteroepitaxial growth and materials properties of pure and Co-doped TiO2 anatase on SrTiO3(001) and LaAlO3(001), grown by oxygen plasma assisted molecular beam epitaxy. This material is a promising new diluted magnetic semiconductor that shows large magnetization and a Curie temperature well above room temperature. We have found that epitaxial films with the highest crystalline quality and most uniform distribution of Co result when a rather slow growth rate ( similar to 0.01 nm/s) is used over a substrate temperature range of 550-600 degreesC on LaAlO3(001). These conditions result in layer-by-layer growth of single-crystal films and a very low density of extremely small nanocrystalline inclusions. In contrast, growth at a higher rate (similar to0.04 nm/s) leads to extensive formation of secondary-phase rutile nanocrystals to which Co diffuses and segregates. The rutile nanocrystals nucleate on the evolving anatase film surface in such a way that lattice strain between the two phases is ntinimized. Cobalt appears to substitute for Ti in the lattice and exhibits a +2 formal oxidation state. Both pure and Co-doped films can be grown as n-type semiconductors by controlled incorporation of oxygen atom vacancies. Free electrons are required to couple the Co(II) spin to a ferromagnetic state. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. EM sa.chambers@pnl.gov RI Droubay, Tim/D-5395-2016; OI Droubay, Tim/0000-0002-8821-0322; Lea, Alan/0000-0002-4232-1553 NR 35 TC 117 Z9 119 U1 2 U2 50 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 OCT 15 PY 2002 VL 418 IS 2 BP 197 EP 210 AR PII S0040-6090(02)00709-5 DI 10.1016/S0040-6090(02)00709-5 PG 14 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 611BY UT WOS:000178997600019 ER PT J AU Gorbunov, NV Morris, JE Greenberger, JS Thrall, BD AF Gorbunov, NV Morris, JE Greenberger, JS Thrall, BD TI Establishment of a novel clonal murine bone marrow stromal cell line for assessment of p53 responses to genotoxic stress SO TOXICOLOGY LA English DT Article DE p53; reporter vector; bone marrow stromal cells; hydrogen peroxide; UVC light; nitric oxide ID NITRIC-OXIDE; DNA-DAMAGE; GENE-EXPRESSION; MAMMALIAN-CELLS; ACCUMULATION; INDUCTION; TOXICITY; PROTEIN; IRRADIATION; RADIATION AB The p53 protein is widely regarded as an important sensor of genotoxic damage in cells, and mutations in p53 are the most frequent observed in human cancers. Rapid assays for evaluating the potential of a chemical or physical agent to alter the transcriptional regulatory role of p53 may therefore serve as useful tools in toxicological research. In this study, the use of enhanced green fluorescent protein (EGFP) as a live cell reporter to assess the transactivation response of p53 to chemical and physical agents was evaluated. A stable murine bone marrow stromal cell line (D2XRIIGFP24) expressing, EGFP under control of p53 response elements was established. D2XRIIGFP24 cells displayed low constitutive background fluorescence which was significantly enhanced in response to exposure to agents that induced p53 protein levels. Increases in EGFP fluorescence in response to oxidative and nitrosative stress as well as UVC irradiation were dose-dependent, detectable within 3 h of exposure and correlated closely with the amount of p53 protein accumulated within the cell. The results demonstrate the potential for rapid and early detection of p53 transactivation using the EGFP reporter approach and indicate this approach is adaptable to a variety of fluorescent assay techniques and a useful cell model for molecular toxicology research. (C) 2002 Published by Elsevier Science Ireland Ltd. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Pittsburgh, Inst Canc, Pittsburgh, PA USA. RP Gorbunov, NV (reprint author), Walter Reed Army Inst Res, Robert Grant Ave,Bldg 503,Room 1A14, Silver Spring, MD 20910 USA. NR 28 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0300-483X J9 TOXICOLOGY JI Toxicology PD OCT 15 PY 2002 VL 179 IS 3 BP 257 EP 266 AR PII S0300-483X(02)00356-6 DI 10.1016/S0300-483X(02)00356-6 PG 10 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 612HQ UT WOS:000179068700006 PM 12270597 ER PT J AU Weaver, MS Michalski, LA Rajan, K Rothman, MA Silvernail, JA Brown, JJ Burrows, PE Graff, GL Gross, ME Martin, PM Hall, M Mast, E Bonham, C Bennett, W Zumhoff, M AF Weaver, MS Michalski, LA Rajan, K Rothman, MA Silvernail, JA Brown, JJ Burrows, PE Graff, GL Gross, ME Martin, PM Hall, M Mast, E Bonham, C Bennett, W Zumhoff, M TI Organic light-emitting devices with extended operating lifetimes on plastic substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID DIODES; STABILITY; COATINGS; POLYMERS AB We fabricate long-lived organic light-emitting devices using a 175 mum thick polyethylene terephthalate substrate coated with an organic-inorganic multilayered barrier film and compare the rate of degradation to glass-based devices. The observed permeation rate of water vapor through the plastic substrate was estimated to be 2x10(-6) g/m(2)/day. Driven at 2.5 mA/cm(2), we measure a device lifetime of 3800 h from an initial luminance of 425 cd/m(2). (C) 2002 American Institute of Physics. C1 Universal Display Corp, Ewing, NJ 08618 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Weaver, MS (reprint author), Universal Display Corp, 375 Phillips Blvd, Ewing, NJ 08618 USA. NR 19 TC 199 Z9 206 U1 7 U2 48 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 OCT 14 PY 2002 VL 81 IS 16 BP 2929 EP 2931 DI 10.1063/1.1514831 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500005 ER PT J AU Schlichenmaier, C Koch, SW Chow, WW AF Schlichenmaier, C Koch, SW Chow, WW TI Linewidth enhancement factor in 1.3 mu m GaAsSb type-II quantum-well lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID GAIN AB The antiguiding or linewidth enhancement factor alpha is computed microscopically for a series of type-II GaAsSb/GaInAs/GaAs quantum-well structures. The results predict alpha values below unity at peak gain suggesting highly stable laser operation with excellent linewidth properties. (C) 2002 American Institute of Physics. C1 Univ Marburg, Fachbereich Phys, D-35032 Marburg, Germany. Univ Marburg, Wissensch Zentrum Mat Wissensch, D-35032 Marburg, Germany. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Schlichenmaier, C (reprint author), Univ Marburg, Fachbereich Phys, Renthof 5, D-35032 Marburg, Germany. NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 2002 VL 81 IS 16 BP 2944 EP 2946 DI 10.1063/1.1514392 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500010 ER PT J AU Romero, MJ Albin, DS Al-Jassim, MM Wu, XZ Moutinho, HR Dhere, RG AF Romero, MJ Albin, DS Al-Jassim, MM Wu, XZ Moutinho, HR Dhere, RG TI Cathodoluminescence of Cu diffusion in CdTe thin films for CdTe/CdS solar cells SO APPLIED PHYSICS LETTERS LA English DT Article ID DOPED CDTE; PHOTOLUMINESCENCE AB We investigate the distribution of Cu acceptor states in CdTe thin films used in high-efficiency solar cells. These states are Cu-Cd and Cu-i(+)-V-Cd(-) complexes, which are relatively deep and shallow acceptors, respectively. Cathodoluminescence spectroscopy and imaging show that, first, Cu-Cd and Cu-i(+)-V-Cd(-) do not coexist and, second, the primary diffuser is represented by Cu-i(+)-V-Cd(-) complexes. Our results are used to discuss the effect of grain boundaries on Cu diffusion. (C) 2002 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Romero, MJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 15 TC 28 Z9 28 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 2002 VL 81 IS 16 BP 2962 EP 2964 DI 10.1063/1.1515119 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500016 ER PT J AU Dawley, JT Clem, PG AF Dawley, JT Clem, PG TI Dielectric properties of random and < 100 > oriented SrTiO3 and (Ba,Sr)TiO3 thin films fabricated on < 100 > nickel tapes SO APPLIED PHYSICS LETTERS LA English DT Article ID METAL FOILS; ELECTRICAL-PROPERTIES AB Properties are presented for random and enhanced <100> orientation SrTiO3 and BaxSr1-xTiO3 (x=0.33, 0.50, and 0.67) films fabricated on base-metal <100> Ni tapes using a chemical solution deposition approach. Films were crystallized in a reducing atmosphere, which prevented Ni oxidation, but permitted growth of SrTiO3 and BaxSr1-xTiO3 films with dielectric loss tan delta between 0.003 and 0.015. For randomly oriented BaxSr1-xTiO3 (x=0, 0.33, 0.5, and 0.67) films, zero-field 100 kHz dielectric constants ranged from 250 to 420. Films with enhanced <100> orientation exhibited zero-field dielectric constants of 980 to 1500, three times higher than random films. Development of such high dielectric constants on Ni suggests a future method for inexpensive, high performance base-metal electrode capacitor fabrication. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dawley, JT (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 97 Z9 102 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 2002 VL 81 IS 16 BP 3028 EP 3030 DI 10.1063/1.1516630 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500038 ER PT J AU Heo, YW Varadarajan, V Kaufman, M Kim, K Norton, DP Ren, F Fleming, PH AF Heo, YW Varadarajan, V Kaufman, M Kim, K Norton, DP Ren, F Fleming, PH TI Site-specific growth of Zno nanorods using catalysis-driven molecular-beam epitaxy SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOLUMINESCENCE PROPERTIES; SEMICONDUCTOR NANOWIRES; VAPOR TRANSPORT; DEPOSITION; OXIDE; MICROSTRUCTURE; ARRAYS; AG AB We report on catalyst-driven molecular beam epitaxy of ZnO nanorods. The process is site specific, as single crystal ZnO nanorod growth is realized via nucleation on Ag films or islands that are deposited on a SiO2-terminated Si substrate surface. Growth occurs at substrate temperatures on the order of 300-500 degreesC. The nanorods are uniform cylinders, exhibiting diameters of 15-40 nm and lengths in excess of 1 mum. With this approach, nanorod placement can be predefined via location of metal catalyst islands or particles. This, coupled with the relatively low growth temperatures needed, suggests that ZnO nanorods could be integrated on device platforms for numerous applications, including chemical sensors and nanoelectronics. (C) 2002 American Institute of Physics. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32606 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32606 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Norton, DP (reprint author), Univ Florida, Dept Mat Sci & Engn, POB 116400,Rhines Hall, Gainesville, FL 32606 USA. RI Kaufman, Michael/A-7737-2012 NR 31 TC 271 Z9 274 U1 5 U2 48 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 OCT 14 PY 2002 VL 81 IS 16 BP 3046 EP 3048 DI 10.1063/1.1512829 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500044 ER PT J AU Breeze, AJ Salomon, A Ginley, DS Gregg, BA Tillmann, H Horhold, HH AF Breeze, AJ Salomon, A Ginley, DS Gregg, BA Tillmann, H Horhold, HH TI Polymer-perylene diimide heterojunction solar cells SO APPLIED PHYSICS LETTERS LA English DT Article ID DONOR-ACCEPTOR HETEROJUNCTIONS; PHOTOVOLTAIC PROPERTIES; CHARGE SEPARATION; PHOTODIODES; DEVICES; DIODES; CONVERSION; COMPOSITES; FILM AB Thin-film small molecule/polymer hybrid bilayer photovoltaic cells have been constructed, exhibiting power conversion efficiencies of 0.71% under 80 mW/cm(2) white light illumination. The parameters influencing the photovoltage of these devices are explored by reversing the order of the photoactive layers while maintaining the same electrode configuration. It has been found that the properties of the organic photoactive layers play an important role in determining the direction of current flow and the photovoltage of the device. Comparison is made to analogous pure small molecule bilayer devices, and conclusions about some of the factors influencing device efficiency are drawn. It has been shown that ordering of the band offsets of the two organic materials plays an important role in determining the polarity of the photocurrent and the photovoltage of the device. (C) 2002 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Jena, D-6900 Jena, Germany. RP Breeze, AJ (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 31 TC 123 Z9 124 U1 2 U2 19 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 2002 VL 81 IS 16 BP 3085 EP 3087 DI 10.1063/1.1515362 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500057 ER PT J AU Lee, S Myers, WR Grossman, HL Cho, HM Chemla, YR Clarke, J AF Lee, S Myers, WR Grossman, HL Cho, HM Chemla, YR Clarke, J TI Magnetic gradiometer based on a high-transition temperature superconducting quantum interference device for improved sensitivity of a biosensor SO APPLIED PHYSICS LETTERS LA English DT Article ID 1/F NOISE; IMMUNOASSAYS; MICROSCOPY; SQUIDS; 77-K AB We describe a gradiometer based on a high-transition temperature superconducting quantum interference device (SQUID) that improves the sensitivity of a SQUID-based biosensor. The first-derivative gradiometer, fabricated from a single layer of YBa2Cu3O7-x, has a baseline of 480 mum and a balance against uniform fields of 1 part in 150. Used in our SQUID "microscope," it reduces the response to parasitic magnetic fields generated by the measurement process to the level of the SQUID noise. The gradiometer-based microscope is two orders of magnitude more sensitive to superparamagnetic nanoparticles bound to biological targets than our earlier magnetometer-based microscope. (C) 2002 American Institute of Physics. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Lee, S (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM jclarke@physics.berkeley.edu RI Lee, Seung-Kyun/A-3464-2008 OI Lee, Seung-Kyun/0000-0001-7625-3141 NR 21 TC 67 Z9 67 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 14 PY 2002 VL 81 IS 16 BP 3094 EP 3096 DI 10.1063/1.1515122 PG 3 WC Physics, Applied SC Physics GA 601RB UT WOS:000178460500060 ER PT J AU Kiplinger, JL John, KD Morris, DE Scott, BL Burns, CJ AF Kiplinger, JL John, KD Morris, DE Scott, BL Burns, CJ TI [(C5Me5)(2)U(Me)(OTf)](2): A new reagent for uranium metallocene chemistry. Preparation of the first actinide hydrazonato complexes SO ORGANOMETALLICS LA English DT Article ID LEWIS-ACID CATALYSTS; STRUCTURAL CHARACTERIZATION; CRYSTAL-STRUCTURE; MOLECULAR-STRUCTURES; HYDROGEN-BONDS; METAL-CARBON; X-RAY; INSERTION; LIGAND; TRIFLUOROMETHANESULFONATE AB The synthesis and characterization of the first actinide hydrazonato, complex, (C5Me5)(2)U(eta(2)(N,N')-CH3-NN=CPh2)(OTf) (3), has been made possible by use of the organouranium (IV) trifluoromethanesulfonate (triflate) Complex [(C5Me5)(2)U(CH3)(OTf)](2) (2; OTf = OSO2-CF3) which is derived from the reaction between (C5Me5)(2)U(CH3)(2) and Ph3COTf The related chemistry for (C5Me5)(2)U(CH3)(Cl) is also reported. All new complexes have been structurally characterized. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Kiplinger, JL (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663, Los Alamos, NM 87545 USA. RI Morris, David/A-8577-2012; Kiplinger, Jaqueline/B-9158-2011; Scott, Brian/D-8995-2017 OI Kiplinger, Jaqueline/0000-0003-0512-7062; Scott, Brian/0000-0003-0468-5396 NR 49 TC 48 Z9 48 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD OCT 14 PY 2002 VL 21 IS 21 BP 4306 EP 4308 DI 10.1021/om0205804 PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 602UE UT WOS:000178522200004 ER PT J AU Amendt, P Turner, RE Landen, OL AF Amendt, P Turner, RE Landen, OL TI Hohlraum-driven high-convergence implosion experiments with multiple beam cones on the Omega laser facility SO PHYSICAL REVIEW LETTERS LA English DT Article ID INERTIAL CONFINEMENT FUSION; NATIONAL IGNITION FACILITY; TETRAHEDRAL HOHLRAUMS; TARGETS; PLASMAS; GROWTH; RAYS AB High-convergence implosion experiments have been performed on the Omega laser facility [T.R. Boehly et al., Opt. Commun. 133, 495 (1997)] using cylindrical gold hohlraums with 40 drive beams arranged into multiple cones. These experiments make use of improved hohlraum radiation symmetry conditions [T.J. Murphy et al., Phys. Rev. Lett. 81, 108 (1998)] to demonstrate near predicted primary (2.45 MeV) neutron production from single-shell implosions with measured deuterium fuel convergence ratios exceeding 20 at an ignition-relevant hohlraum case-to-capsule ratio approximate to3. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Amendt, P (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 24 TC 25 Z9 25 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 165001 DI 10.1103/PhysRevLett.89.165001 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300020 PM 12398728 ER PT J AU Batista, CD AF Batista, CD TI Electronic ferroelectricity in the Falicov-Kimball model SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-DIELECTRIC-CONSTANT; STATE AB I show that a spontaneous electric polarization exists in the solution of the Falicov-Kimball model by mapping the strong coupling limit of this Hamiltonian into an xxz spin 1/2 model with a magnetic field. In this way, I determine the phase diagram of the strongly interacting model and show the existence of a transition to a mixed-valence regime containing two phases: an orbitally ordered state and a Bose-Einstein condensation of excitons with a built-in electric polarization. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Batista, Cristian/J-8008-2016 NR 20 TC 84 Z9 85 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 166403 DI 10.1103/PhysRevLett.89.166403 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300033 PM 12398741 ER PT J AU Benczik, IJ Toroczkai, Z Tel, T AF Benczik, IJ Toroczkai, Z Tel, T TI Selective sensitivity of open chaotic flows on inertial tracer advection: Catching particles with a stick SO PHYSICAL REVIEW LETTERS LA English DT Article ID FREEMAN SCHOLAR LECTURE; EQUATION-OF-MOTION; POISEUILLE FLOW; DYNAMICS; SPHERE; FLUID AB We investigate the effects of finite size and inertia of a small spherical particle immersed in an open unsteady flow which, for ideal tracers, generates transiently chaotic trajectories. The inertia effects may strongly modify the chaotic motion to the point that attractors may appear in the configuration space. These studies are performed in a model of the two-dimensional flow past a cylindrical obstacle. The relevance to modeling efforts of biological pathogen transport in large-scale flows is discussed. Since the tracer dynamics is sensitive to the particle inertia and size, simple geometric setups in such flows could be used as a particle mixture segregator separating and trapping particles. C1 Eotvos Lorand Univ, Inst Theoret Phys, H-1518 Budapest, Hungary. Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. RP Eotvos Lorand Univ, Inst Theoret Phys, POB 32, H-1518 Budapest, Hungary. RI Toroczkai, Zoltan/A-3421-2008 OI Toroczkai, Zoltan/0000-0002-6602-2849 NR 21 TC 50 Z9 50 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 164501 DI 10.1103/PhysRevLett.89.164501 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300018 PM 12398726 ER PT J AU Bogdanov, PV Lanzara, A Zhou, XJ Yang, WL Eisaki, H Hussain, Z Shen, ZX AF Bogdanov, PV Lanzara, A Zhou, XJ Yang, WL Eisaki, H Hussain, Z Shen, ZX TI Anomalous momentum dependence of the quasiparticle scattering rate in overdoped Bi2Sr2CaCu2O8 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; DOPED BI2SR2CACU2O8; NEUTRON-SCATTERING; FERMI-SURFACE; PHOTOEMISSION; PHONON AB The question of the anisotropy of the electron scattering in high temperature superconductors is investigated using high resolution angle-resolved photoemission data from Pb-doped Bi2Sr2CaCu2O8 (Bi2212) with suppressed superstructure. The scattering rate of low energy electrons along two bilayer-split pieces of the Fermi surface is measured (via the quasiparticle peak width), and no increase of scattering towards the antinode (pi,0) region is observed, contradicting the expectation from Q=(pi,pi) scattering. The results put a limit on the effects of Q=(pi,pi) scattering on the electronic structure of this overdoped superconductor with still very high T-c. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Bogdanov, PV (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RI Yang, Wanli/D-7183-2011 OI Yang, Wanli/0000-0003-0666-8063 NR 25 TC 28 Z9 28 U1 1 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 OCT 14 PY 2002 VL 89 IS 16 AR 167002 DI 10.1103/PhysRevLett.89.167002 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300039 PM 12398747 ER PT J AU Chen, PS Tajima, T Takahashi, Y AF Chen, PS Tajima, T Takahashi, Y TI Plasma wakefield acceleration for ultrahigh-energy cosmic rays SO PHYSICAL REVIEW LETTERS LA English DT Article ID ZATSEPIN-KUZMIN CUTOFF; SPECTRUM; NEUTRINOS AB A cosmic acceleration mechanism is introduced which is based on the wakefields excited by the Alfven shocks in a relativistically flowing plasma. We show that there exists a threshold condition for transparency below which the accelerating particle is collision-free and suffers little energy loss in the plasma medium. The stochastic encounters of the random accelerating-decelerating phases results in a power-law energy spectrum: f(epsilon)proportional to1/epsilon(2). As an example, we discuss the possible production in the atmosphere of gamma ray bursts of ultrahigh-energy cosmic rays (UHECR) exceeding the Greisen-Zatsepin-Kuzmin cutoff. The estimated event rate in our model agrees with that from UHECR observations. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Adv Photon Res Ctr, Japan Atom Energy Res Inst, Kyoto 6190215, Japan. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Chen, PS (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 35 TC 70 Z9 71 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 OCT 14 PY 2002 VL 89 IS 16 AR 161101 DI 10.1103/PhysRevLett.89.161101 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300003 PM 12398711 ER PT J AU Eichten, EJ Lane, K Quigg, C AF Eichten, EJ Lane, K Quigg, C TI B-meson gateways to missing charmonium levels SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANTIQUARK BOUND-STATES; D-WAVE QUARKONIUM; HADRONIC TRANSITIONS; HEAVY QUARKS; ANNIHILATION; DECAYS; PRODUCTIONS; SEARCH AB We outline a coherent strategy for exploring the four remaining narrow charmonium states [eta(c)'(2S(0)), h(c)(1P(1)), eta(c2)(1(1)D(2)), and psi(2)(1(3)D(2))] expected to lie below charm threshold. Produced in B-meson decays, these levels should be identifiable now via striking radiative transitions among charmonium levels and in exclusive final states of kaons and pions. Their production and decay rates will provide much needed new tests for theoretical descriptions of heavy quarkonia. C1 Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. RP Fermilab Natl Accelerator Lab, Dept Theoret Phys, POB 500, Batavia, IL 60510 USA. EM eichten@fnal.gov; lane@physics.bu.edu; quigg@fnal.gov NR 36 TC 79 Z9 82 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 162002 DI 10.1103/PhysRevLett.89.162002 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300008 PM 12398716 ER PT J AU Keiter, PA Drake, RP Perry, TS Robey, HF Remington, BA Iglesias, CA Wallace, RJ Knauer, J AF Keiter, PA Drake, RP Perry, TS Robey, HF Remington, BA Iglesias, CA Wallace, RJ Knauer, J TI Observation of a hydrodynamically driven, radiative-precursor shock SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY FOAM TARGETS; PLASMA; FLOWS AB Observations of a radiative-precursor shock that evolves from a purely hydrodynamic system are presented. The radiative precursor is observed in low-density SiO2 aerogel foam using x-ray absorption spectroscopy. A plastic slab, shocked and accelerated by high-intensity laser irradiation, drives the shock which then produces the radiative precursor. The length and temperature profile of the radiative precursor are examined as the intensity of the laser is varied. C1 Univ Michigan, Ann Arbor, MI 48109 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Rochester, Laser Energet Lab, Rochester, NY USA. RP Keiter, PA (reprint author), Univ Michigan, Ann Arbor, MI 48109 USA. RI Drake, R Paul/I-9218-2012; Keiter, Paul/J-3037-2013; Perry, Theodore/K-3333-2014 OI Drake, R Paul/0000-0002-5450-9844; Perry, Theodore/0000-0002-8832-2033 NR 18 TC 48 Z9 50 U1 2 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 OCT 14 PY 2002 VL 89 IS 16 AR 165003 DI 10.1103/PhysRevLett.89.165003 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300022 PM 12398730 ER PT J AU Liuti, S Ent, R Keppel, CE Niculescu, I AF Liuti, S Ent, R Keppel, CE Niculescu, I TI Perturbative QCD analysis of local duality in a fixed W-2 framework SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEEP-INELASTIC-SCATTERING; PARTON DISTRIBUTIONS; HIGHER TWIST; NUCLEON SCATTERING; LEADING ORDER; L/SIGMA-T; LOW Q(2); F-2; RESONANCES; EXTRACTION AB We study the Q(2) dependence of large x F-2 nucleon structure function data, with the aim of providing a perturbative QCD based, quantitative analysis of parton-hadron duality. As opposed to previous analyses at fixed x, we use a framework in fixed W-2. We uncover a breakdown of the twist-4 approximation with a renormalon type improvement at O(1/Q(4)) which affects the initial evolution of parton distributions. C1 Univ Virginia, Charlottesville, VA 22901 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Hampton Univ, Hampton, VA 23668 USA. RP Liuti, S (reprint author), Univ Virginia, Charlottesville, VA 22901 USA. NR 35 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 162001 DI 10.1103/PhysRevLett.89.162001 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300007 PM 12398715 ER PT J AU Mounaix, P Divol, L AF Mounaix, P Divol, L TI Near-threshold reflectivity fluctuations in the independent-convective-hot-spot-model limit of a spatially smoothed laser beam SO PHYSICAL REVIEW LETTERS LA English DT Article ID STIMULATED BRILLOUIN-SCATTERING; BACKSCATTERING INSTABILITIES; STATISTICS; BEHAVIOR; PLASMA AB In the framework of the independent-hot-spot model, it is shown that the reflectivity resulting from scattering instabilities when a spatially smoothed laser beam interacts with a plasma exhibits large statistical fluctuations near threshold. The importance of the fluctuations is discussed in terms of a confidence interval for the reflectivity, which is more relevant to experimental measurements than the average reflectivity. An analytical model for the fluctuating reflectivity is developed and shown to be in good agreement with numerical simulations. The influence of the transverse size of the interaction region is studied. C1 Ecole Polytech, CNRS, Ctr Phys Theor, UMR 7644, F-91128 Palaiseau, France. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Mounaix, P (reprint author), Ecole Polytech, CNRS, Ctr Phys Theor, UMR 7644, F-91128 Palaiseau, France. NR 10 TC 9 Z9 9 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 OCT 14 PY 2002 VL 89 IS 16 AR 165005 DI 10.1103/PhysRevLett.89.165005 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300024 PM 12398732 ER PT J AU Nellis, WJ AF Nellis, WJ TI Shock compression of deuterium near 100 GPa pressures SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUID MOLECULAR-HYDROGEN; EQUATION-OF-STATE; LIQUID DEUTERIUM; DENSE HYDROGEN; 900 KBAR; 1.4 MBAR; HUGONIOT; NITROGEN; CONDUCTIVITY; TRANSITION AB The shock-compression curve (Hugoniot) of D-2 near 100 GPa pressures (1 Mbar) has been contro-versial because the two published measurements have limiting compressions of fourfold and sixfold. Our purpose is to examine published experimental results to decide which, if either, is probably correct. The published Hugoniot data of low-Z diatomic molecules have a universal behavior. The deuterium data of Knudson et al. (fourfold limiting compression) have this universal behavior, which suggests that Knudson et al. are correct and shows that deuterium behaves as other low-Z elements at high tem-peratures. In D-2, H-2, N-2, CO, and O-2, dissociation completes and average kinetic energy dominates average potential energy above similar to60 GPa. Below similar to30 GPa, D-2, H-2, N-2, CO, and O-2 are diatomic. D-2 dissociation is accompanied by a temperature-driven nonmetal-metal transition at similar to50 GPa. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nellis, WJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 27 TC 41 Z9 44 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 OCT 14 PY 2002 VL 89 IS 16 AR 165502 DI 10.1103/PhysRevLett.89.165502 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300026 PM 12398734 ER PT J AU Porcar, L Hamilton, WA Butler, PD Warr, GG AF Porcar, L Hamilton, WA Butler, PD Warr, GG TI Scaling of shear-induced transformations in membrane phases SO PHYSICAL REVIEW LETTERS LA English DT Article ID TO-LAMELLAR TRANSITION; SYSTEM; MICROEMULSIONS; SCATTERING; RHEOLOGY AB Surfactant sponges are complex-fluid phases made up of convolutions of bilayer sheets. Although isotropic and free flowing they exhibit transient birefringence when stirred, reminiscent of the birefringence of lamellar phases. Previous attempts to understand this effect have led to confusing and often conflicting results. We have used a novel approach to designing the chemical system that gives us control over the relevant parameters needed to study microstructural and macroscopic responses of these phases to shear. We find a remarkable universal scaling behavior for both sponge and shear-induced lamellar states, which resolves a number of long-standing questions about these systems. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia. RP Hamilton, WA (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Butler, Paul/D-7368-2011 NR 29 TC 18 Z9 18 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 168301 DI 10.1103/PhysRevLett.89.168301 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300052 PM 12398760 ER PT J AU Wang, EK Wang, XN AF Wang, EK Wang, XN TI Jet tomography of hot and cold nuclear matter SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATIVE ENERGY-LOSS; HEAVY-ION COLLISIONS; AA COLLISIONS; P(T) SPECTRA; SCATTERING; QCD; ENVIRONMENT; PARTONS; OPACITY; PLASMA AB Modification of parton fragmentation functions by multiple scattering and gluon bremsstrahlung in nuclear media is shown to describe very well the recent HERMES data in deeply inelastic scattering, giving the first evidence of the A(2/3) dependence of the modification. The energy loss is found to be approximate to0.5 GeV/fm for a 10-GeV quark in an Au nucleus. Including the effect of expansion, analysis of the pi(0) spectra in central Au+Au collisions at roots=130 GeV yields an averaged energy loss equivalent to approximate to7.3 GeV/fm in a static medium. Predictions for central Au+Au collisions at roots=200 GeV are also given. C1 Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Wang, EK (reprint author), Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China. NR 29 TC 230 Z9 232 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 OCT 14 PY 2002 VL 89 IS 16 AR 162301 DI 10.1103/PhysRevLett.89.162301 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300009 PM 12398717 ER PT J AU Yang, X Wang, XB Niu, SQ Pickett, CJ Ichiye, T Wang, LS AF Yang, X Wang, XB Niu, SQ Pickett, CJ Ichiye, T Wang, LS TI Coulomb- and antiferromagnetic-induced fission in doubly charged cubelike Fe-S clusters SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTODETACHMENT PHOTOELECTRON-SPECTROSCOPY; IRON-SULFUR CLUSTERS; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; GAS-PHASE; ANIONS; PROTEIN; MODELS; CENTERS; SITES AB We report the observation of symmetric fission in doubly charged Fe-S cluster anions, [Fe4S4X4](2-)-->2[Fe2S2X2](-) (X=Cl,Br), owing to both Coulomb repulsion and antiferromagnetic coupling. Photoelectron spectroscopy shows that both the parent and the fission fragments have similar electronic structures and confirms the inverted energy schemes due to the strong spin polarization of the Fe 3d levels. The current observation provides direct confirmation for the unusual spin couplings in the [Fe4S4X4](2-) clusters, which contain two valent-delocalized and ferromagnetically coupled Fe2S2 subunits. C1 Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Sch Mol Biosci, Pullman, WA 99164 USA. John Innes Ctr, Dept Biol Chem, Norwich NR4 7UH, Norfolk, England. RP Washington State Univ, Dept Phys, Richland, WA 99352 USA. EM ls.wang@pnl.gov RI PICKETT, CHRISTOPHER/F-3896-2010 OI PICKETT, CHRISTOPHER/0000-0003-3142-0780 NR 27 TC 18 Z9 18 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 2002 VL 89 IS 16 AR 163401 DI 10.1103/PhysRevLett.89.163401 PG 4 WC Physics, Multidisciplinary SC Physics GA 600HJ UT WOS:000178384300012 PM 12398720 ER PT J AU Siino, JS Nazarov, IB Svetlova, MP Solovjeva, LV Adamson, RH Zalenskaya, IA Yau, PM Bradbury, EM Tomilin, NV AF Siino, JS Nazarov, IB Svetlova, MP Solovjeva, LV Adamson, RH Zalenskaya, IA Yau, PM Bradbury, EM Tomilin, NV TI Photobleaching of GFP-labeled H2AX in chromatin: H2AX has low diffusional mobility in the nucleus SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article DE chromatin; histone variant; H2AX; phosphatase PP1 alpha; GFP ID DOUBLE-STRAND BREAKS; LIVING HUMAN-CELLS; RAPID EXCHANGE; HISTONE MODIFICATIONS; DNA; PHOSPHORYLATION; PROTEIN; DYNAMICS; BINDING; SITES AB The Ser-139 phosphorylated form of replacement histone H2AX (gamma-MAX) is induced within large chromatin domains by double-strand DNA breaks (DSBs) in mammalian chromosomes. This modification is known to be important for the maintenance of chromosome stability. However, the mechanism of gamma-H2AX formation at DSBs and its subsequent elimination during DSB repair remains unknown. gamma-H2AX formation and elimination could occur by direct phosphorylation and dephosphorylation of H2AX in situ in the chromatin. Alternatively, H2AX molecules could be phosphorylated freely in the nucleus, diffuse into chromatin regions containing DSBs and then diffuse out after DNA repair. In this study we show that free histone H2AX can be efficiently phosphorylated in vitro by nuclear extracts and that free gamma-H2AX can be dephosphorylated in vitro by the mammalian protein phosphatase 1-alpha. We made N-terminal fusion constructs of H2AX with green fluorescent protein (GFP) and studied their diffusional mobility in transient and stable cell transfections. In the absence or presence of DSBs, only a small fraction of GFP-H2AX is redistributed after photobleaching, indicating that in vivo this histone is essentially immobile in chromatin. This suggests that, gamma-H2AX formation in chromatin is unlikely to occur by diffusion of free histone and 7-H2AX dephosphorylation may involve the mammalian protein phosphatase lot. (C) 2002 Elsevier Science (USA). All rights reserved. C1 Univ Calif Davis, Sch Med, Dept Biol Chem, Davis, CA 95616 USA. Russian Acad Sci, Inst Cytol, Dept Chromosome Stabil, St Petersburg 194064, Russia. Univ Calif Davis, Sch Med, Dept Human Physiol, Davis, CA 95616 USA. Los Alamos Natl Lab, Biosci Div, MSM 888, Los Alamos, NM 87545 USA. RP Tomilin, NV (reprint author), Univ Calif Davis, Sch Med, Dept Biol Chem, Davis, CA 95616 USA. NR 34 TC 44 Z9 50 U1 1 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD OCT 11 PY 2002 VL 297 IS 5 BP 1318 EP 1323 AR PII S0006-291X(02)02383-5 DI 10.1016/S0006-291X(02)02383-5 PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 605TH UT WOS:000178692800039 PM 12372432 ER PT J AU Brewer, L Corzett, M Balhorn, R AF Brewer, L Corzett, M Balhorn, R TI Condensation of DNA by spermatid basic nuclear proteins SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID MOUSE TRANSITION PROTEIN-1; NUCLEOTIDE-SEQUENCE; SECONDARY STRUCTURE; PROTAMINE; ZINC; TP2; CHROMATIN; SPERMIOGENESIS; STABILITY; INVITRO AB Two transition proteins, TP1 and TP2, participate in the repackaging of the spermatid genome early in mammalian spermiogenesis, coincident with the first detectable changes in chromatin condensation. Using an optical trap and a two-channel flow cell to move single DNA molecules into buffer containing protein, we have measured the rates of DNA condensation and decondensation induced by the binding of Syrian hamster transition proteins TP1 and TP2 and protamines P1 and P2. The results show that both transition proteins condense free DNA, with rates similar to those of protamine 1 and 2. DNA molecules condensed with TP1 were significantly less stable than DNA condensed by protamine or by TP2. Experiments conducted with a peptide corresponding to the C-terminal 25 residues of TP2 showed that this domain is responsible for condensing DNA. Experiments conducted with two fragments of TP1 containing arginine and lysine residues demonstrated that DNA binding by TP1 must involve more than these basic sequences. Zinc facilitated the condensation of DNA by P2 but not by TP2. The dissociation rates of TP2 and P2 from DNA were not affected by the addition of zinc. C1 Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Brewer, L (reprint author), Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. RI Brewer, Laurence/G-4056-2012 FU NICHD NIH HHS [1 K25 HD01387-02] NR 45 TC 74 Z9 77 U1 0 U2 3 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 11 PY 2002 VL 277 IS 41 BP 38895 EP 38900 DI 10.1074/jbc.M204755200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 602XK UT WOS:000178529600112 PM 12140285 ER PT J AU Kleiger, G Eisenberg, D AF Kleiger, G Eisenberg, D TI GXXXG and GXXXA motifs stabilize FAD and NAD(P)-binding Rossmann folds through C-alpha-H center dot center dot center dot O hydrogen bonds and van der Waals interactions SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE sequence motif; Rossmann fold; hydrogen bond; FAD-binding; NAD(P)-binding ID CRYSTAL-STRUCTURE; HELIX INTERACTIONS; PROTEIN; BINDING; DIMERIZATION; SPECIFICITY; PREDICTION; RESIDUES; DOMAIN AB Here we present evidence that domains in soluble proteins containing either the GXXXG or GXXXA motif are stabilized by the interaction of a beta-strand with the following alpha-helix. As an example, we characterized a beta-strand-helix interaction from the FAD or NAD(P)-binding Rossmann fold. The Rossmann fold is one of the three most highly represented folds in the Protein Data Bank (PDB). A subset of the proteins that adopt the Rossmann fold also bind to nucleotide cofactors such as FAD and NAD(P) and function as oxidoreductases. These Rossmann folds can often be identified by the short amino acid sequence motif, GX(1-2)GXXG. Here, we present evidence that in addition to this sequence motif, Rossmann folds that bind FAD and NAD(P) also typically contain either GXXXG or GXXXA motifs, where the first glycyl residue of these motifs and the third glycyl residue of the GX(1-2)GXXG motif are the same residue. These two motifs appear to stabilize the Rossmann fold: the first glycyl residue of either the GXXXG or GXXXA motif contacts the carbonyl oxygen atom from the first glycyl residue of the GX(1-2)GXXG motif consistent with the formation of a C-alpha-H...O hydrogen bond. In addition, both the glycyl and alanyl residues of the GXXXG or GXXXA motifs form van der Waals interactions with either a valine or isoleucine residue located either seven or eight residues further back along the polypeptide chain from the first glycine of the GXXXG or GXXXA motifs. Therefore, we combine both the GX(1-2)GXXG and GXXXG/A motifs into an extended motif, V/IXGX(1-2)GXXGXXXG/A, that is more strongly indicative than previously described motifs of Rossmann folds that bind FAD or NAD(P). The V/IXGX(1-2)GXXGXXXG/A motif can be used to search genomic sequence data and to annotate the function of proteins containing the motif as oxidoreductases, including proteins of previously unknown function. (C) 2002 Published by Elsevier Science Ltd. C1 Univ Calif Los Angeles, Howard Hughes Med Inst, DOE Ctr Genom & Proteom, Inst Mol Biol, Los Angeles, CA 90095 USA. RP Eisenberg, D (reprint author), Univ Calif Los Angeles, Howard Hughes Med Inst, DOE Ctr Genom & Proteom, Inst Mol Biol, Box 951570, Los Angeles, CA 90095 USA. NR 27 TC 115 Z9 117 U1 1 U2 12 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 11 PY 2002 VL 323 IS 1 BP 69 EP 76 DI 10.1016/S0022-2836(02)00885-9 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 606MF UT WOS:000178737200007 PM 12368099 ER PT J AU Kim, SH Doleans, M Jeon, DO Sundelin, R AF Kim, SH Doleans, M Jeon, DO Sundelin, R TI Higher-order-mode (HOM) power in elliptical superconducting cavities for intense pulsed proton accelerators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE linac; higher-order-mode (HOM); superconducting cavity; beam time-structure resonance AB In linacs for intense pulsed proton accelerators, the beam has a multiple time-structure, and each beam time-structure generates resonance. When a higher-order mode (HOM) is near these resonance frequencies, the induced voltage could be large and accordingly the resulting HOM power, too. In order to understand the effects of a complex beam time-structure on the mode excitations and the resulting HOM powers in elliptical superconducting cavities, analytic expressions are developed, with which the beam-induced voltage and corresponding power are explored, taking into account the properties of HOM frequency behavior in elliptical superconducting cavities. The results and understandings from this analysis are presented with the beam parameters of the Spallation Neutron Source (SNS) superconducting linac. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Spallat Neutron Source Project, Oak Ridge, TN 37830 USA. Jlab, Newport News, VA 23606 USA. RP Kim, SH (reprint author), Spallat Neutron Source Project, 701 Scarboro Rd MS 6473, Oak Ridge, TN 37831 USA. RI Jeon, Dong-O/S-2137-2016; OI Jeon, Dong-O/0000-0001-6482-5878; KIM, SANG-HO/0000-0001-5190-9909; doleans, marc/0000-0003-4542-8724 NR 4 TC 9 Z9 9 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 2002 VL 492 IS 1-2 BP 1 EP 10 AR PII S0168-9002(02)01286-X DI 10.1016/S0168-9002(02)01286-X PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 608BM UT WOS:000178825300001 ER PT J AU Jiang, CL Back, BB Gomes, I Heinz, AM Nolen, J Rehm, KE Savard, G Schiffer, JP AF Jiang, CL Back, BB Gomes, I Heinz, AM Nolen, J Rehm, KE Savard, G Schiffer, JP TI Yield calculations for a facility for short-lived nuclear beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE isotope production; radioactive beams; beam fragmentation; in-flight fission; isotope separation on-line; thick target effects ID FRAGMENTATION; SYSTEMATICS; COLLISIONS; RELEASE; FISSION; IONS AB Yields for a broad range of radioactive nuclei produced by spallation reactions, neutron-induced fission, in-flight projectile fragmentation and in-flight fission have been calculated for beams of stable nuclei at energies of 100-1000 MeV/u. Calculations of cross-sections and yields, attenuation effects due to absorption, production from secondary reactions, and transport efficiencies for mass selection are discussed. Rare isotope yields as functions of bombarding energies for both reaccelerated and directly produced fast-fragmentation beams are presented. This information provides a foundation for a cost-effective design of a next generation rare isotope accelerator. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Jiang, CL (reprint author), Argonne Natl Lab, Div Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Heinz, Andreas/E-3191-2014 NR 39 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 2002 VL 492 IS 1-2 BP 57 EP 73 AR PII S0168-9002(02)01352-9 DI 10.1016/S0168-9002(02)01352-9 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 608BM UT WOS:000178825300008 ER PT J AU Plum, MA Bravin, E Bosser, J Maccaferri, R AF Plum, MA Bravin, E Bosser, J Maccaferri, R TI N-2 and Xe gas scintillation cross-section, spectrum, and lifetime measurements from 50 MeV to 25 GeV at the CERN PS and Booster SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE scintillation; accelerator; diagnostic; cross-section; nitrogen; xenon AB Beam parameters in CERN's Proton Synchrotron (PS) accelerator must be controlled (and measured) with tighter precision than ever before to meet the stringent requirements of the Large Hadron Collider (LHC) program. A nondestructive beam profile measurement system would be a valuable diagnostic tool. To this end, we measured N-2 and Xe gas scintillation absolute cross-sections and lifetimes for proton beam energies from 1.4 to 25 GeV kinetic energy, which should prove valuable in the design and construction of a gas scintillation profile measurement system. We also measured relative cross-sections for proton beam energies between 0.05 and 1.4 GeV kinetic energy. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87454 USA. CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland. RP Plum, MA (reprint author), Los Alamos Natl Lab, MS H838,SNS-DO, Los Alamos, NM 87454 USA. NR 17 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 2002 VL 492 IS 1-2 BP 74 EP 90 AR PII S0168-9002(02)01287-1 DI 10.1016/S0168-9002(02)01287-1 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 608BM UT WOS:000178825300009 ER PT J AU Beccherle, R Darbo, G Gagliardi, G Gemme, C Morettini, P Musico, P Osculati, B Oppizzi, P Pratolongo, F Ruscino, E Schiavi, C Vernocchi, F Blanquart, L Einsweiler, K Meddeler, G Richardson, J Comes, G Fischer, P Calvet, D Boyd, R Sicho, P AF Beccherle, R Darbo, G Gagliardi, G Gemme, C Morettini, P Musico, P Osculati, B Oppizzi, P Pratolongo, F Ruscino, E Schiavi, C Vernocchi, F Blanquart, L Einsweiler, K Meddeler, G Richardson, J Comes, G Fischer, P Calvet, D Boyd, R Sicho, P TI MCC: the Module Controller Chip for the ATLAS Pixel Detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE ASIC; radiation hardness; silicon pixel detectors; ATLAS; LHC ID ELECTRONICS AB In this article we describe the architecture of the Module Controller Chip for the ATLAS Pixel Detector. The project started in 1997 with the definition of the system specifications. A first fully-working rad-soft prototype was designed in 1998, while a radiation hard version was submitted in 2000. The 1998 version was used to build pixel detector modules. Results from those modules and from the simulated performance in ATLAS are reported. In the article we also describe the hardware/software tools developed to test the MCC performance at the LHC event rate. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Genoa, Dipartimento Fis, Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy. Lawrence Berkeley Natl Lab, Berkeley, CA USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Phys Corpusculaire Lab, Clermont Ferrand, France. Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Acad Sci Czech Republic, Inst Phys, Prague, Czech Republic. RP Darbo, G (reprint author), Univ Genoa, Dipartimento Fis, Ist Nazl Fis Nucl, Sez Genova, Via Dodecaneso 33, I-16146 Genoa, Italy. EM giovanni.darbo@ge.infn.it OI Osculati, Bianca Maria/0000-0002-7246-060X NR 15 TC 28 Z9 28 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 OCT 11 PY 2002 VL 492 IS 1-2 BP 117 EP 133 AR PII S0168-9002(02)01279-2 DI 10.1016/S0168-9002(02)01279-2 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 608BM UT WOS:000178825300013 ER PT J AU Maruyama, T Brachmann, A Clendenin, JE Desikan, T Garwin, EL Kirby, RE Luh, DA Turner, J Prepost, R AF Maruyama, T Brachmann, A Clendenin, JE Desikan, T Garwin, EL Kirby, RE Luh, DA Turner, J Prepost, R TI A very high charge, high polarization gradient-doped strained GaAs photocathode SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE polarized electron source; GaAs photocathode ID ELECTRON SOURCE; SUPERLATTICE; LIMIT; PHOTOEMISSION; SURFACE AB A high-gradient-doping technique is applied to strained polarized photocathodes. A 5.0-7.5 nm p-type surface layer doped to 5 x 10(19) cm(-3) is found sufficient to overcome the surface charge limit while maintaining high beam polarization. This technique can be employed to meet the charge requirements of the Next Linear Collider with a polarization approaching 80%. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. RP Maruyama, T (reprint author), Stanford Linear Accelerator Ctr, MS 78,2572 Sand Hill Rd, Menlo Pk, CA 94025 USA. RI LUH, DAH-AN/B-3921-2008 NR 20 TC 54 Z9 55 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 2002 VL 492 IS 1-2 BP 199 EP 211 AR PII S0168-9002(02)01290-1 DI 10.1016/S0168-9002(02)01290-1 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 608BM UT WOS:000178825300019 ER PT J AU Hasnah, M Oltulu, O Zhong, Z Chapman, D AF Hasnah, M Oltulu, O Zhong, Z Chapman, D TI Single-exposure simultaneous diffraction-enhanced imaging SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A new method of acquiring and analyzing diffraction-enhanced images (DEI) is presented. This method has been performed at the National Synchrotron Light Source and is based on using a novel two-crystal analyzer (Lane and Bragg analyzer). This system delivers simultaneously a pair of images with differing refraction sensitivity that is necessary for extracting absorption and refraction information using the DEI method. Although the system is not as flux efficient as a DEL system using a Bragg analyzer, it eliminates problems associated with object motion in between exposures. The system, method of interpreting the results and illustrative examples of experiments are presented and discussed. (C) 2002 Elsevier Science B.V. All rights reserved. C1 IIT, CSRRI, Chicago, IL 60616 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Hasnah, M (reprint author), IIT, CSRRI, 3101 S Dearborn, Chicago, IL 60616 USA. RI Chapman, Dean/I-6168-2013 OI Chapman, Dean/0000-0001-6590-4156 NR 4 TC 4 Z9 4 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 OCT 11 PY 2002 VL 492 IS 1-2 BP 236 EP 240 AR PII S0168-9002(02)01288-3 DI 10.1016/S0168-9002(02)01288-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 608BM UT WOS:000178825300021 ER PT J AU Meyers, JS Chumbley, LS Laabs, F Pecharsky, AO AF Meyers, JS Chumbley, LS Laabs, F Pecharsky, AO TI Determination of phases in as prepared Gd-5(SixGe1-x)(4), where x congruent to 1/2 SO SCRIPTA MATERIALIA LA English DT Article DE scanning electron microscopy; rare earth; intermetallic; microstructure; Gd5Si2Ge2 AB Phase identification of Gd-5(Si1.95Ge2.05), produced using commercial grade Gd and induction melting, showed that various contaminant and second phases were produced along with the desired Gd-5(Si1.95Ge2.05) matrix. These phases included Gd-1(Si,Ge)(1), Ta2Si crystals that are a result of reaction with the crucible, and a Widmanstatten structure of Gd-5(Si,Ge)(3) rods. Published by Elsevier Science Ltd. on behalf of Acta Materialia Inc. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Iowa State Univ, Ames Lab, 206 Wilhelm, Ames, IA 50011 USA. EM jmeyers@iastate.edu NR 7 TC 26 Z9 28 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD OCT 11 PY 2002 VL 47 IS 8 BP 509 EP 514 AR PII S1359-6462(02)00166-5 DI 10.1016/S1359-6462(02)00166-5 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 603DD UT WOS:000178542800003 ER PT J AU Bader, SD AF Bader, SD TI Preface to the viewpoint set on: nanostructured permanent magnets SO SCRIPTA MATERIALIA LA English DT Article DE nanocrystalline materials; magnetic properties; coercivity; hard magnets; giant magnetoresistance AB The present viewpoint set is on development of nanocomposite permanent magnets. A persistent theme is that such materials are inherently multiphase and interdispersed on the nanoscale, and that major improvements are indeed possible and accessible. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Bader, SD (reprint author), Argonne Natl Lab, Div Mat Sci, Bldg 223, Argonne, IL 60439 USA. NR 2 TC 2 Z9 2 U1 0 U2 1 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 OCT 11 PY 2002 VL 47 IS 8 BP 527 EP 529 AR PII S1359-6462(02)00180-X DI 10.1016/S1359-6462(02)00180-X PG 3 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 603DD UT WOS:000178542800006 ER PT J AU Branagan, DJ Kramer, MJ Dennis, KW McCallum, RW AF Branagan, DJ Kramer, MJ Dennis, KW McCallum, RW TI Low temperature hysteresis in high anisotropy systems SO SCRIPTA MATERIALIA LA English DT Article DE magnetic properties; coercivity; hard magnets; melt spinning; rare earth ID EXCHANGE AB This paper is focused on understanding hysteresis in Dy3Al2, which is a member of a class of high anisotropy compounds containing high fractions of rare earth elements with no 3-d transition metals. Analysis of the data suggests that the principal domain wall pinning mechanism does not involve the grain boundaries but instead arises from interactions between either the ferromagnetic glass or the ferromagnetic Dy3Al2 phase with the antiferromagnetic DyAl second phase through an exchange bias mechanism. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Idaho Natl Engn & Envirom Lab, Bechtel BWXT Idaho LLC, Idaho Falls, ID 83415 USA. Iowa State Univ, Ames Lab, Ames, IA USA. RP Branagan, DJ (reprint author), Idaho Natl Engn & Envirom Lab, Bechtel BWXT Idaho LLC, Idaho Falls, ID 83415 USA. NR 14 TC 3 Z9 3 U1 0 U2 8 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 OCT 11 PY 2002 VL 47 IS 8 BP 537 EP 543 AR PII S1359-6462(02)00175-6 DI 10.1016/S1359-6462(02)00175-6 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 603DD UT WOS:000178542800008 ER PT J AU Kramer, MJ Lewis, LH Tang, Y Dennis, KW McCallum, RW AF Kramer, MJ Lewis, LH Tang, Y Dennis, KW McCallum, RW TI Microstructural refinement in melt-spun Nd2Fe14B SO SCRIPTA MATERIALIA LA English DT Article DE permanent magnets; solidification; Nd-Fe-B; recalescence ID ND-FE-B; UNDERCOOLED MELTS; PERMANENT-MAGNETS; SOLIDIFICATION AB The phase selection process during solidification of Nd2Fe14B melt-spun alloys is highly dependent on a few processing parameters. The processing variables that determine the three typical microstructures of melt-spun ribbons are described and a general peritectic rapid solidification model incorporating recalescence is presented. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Brookhaven Natl Lab, Energy Sci & Technol Dept, Upton, NY 11973 USA. RP Kramer, MJ (reprint author), Iowa State Univ, Ames Lab, US DOE, 37 Wilhelm Hall, Ames, IA 50011 USA. NR 20 TC 5 Z9 6 U1 1 U2 3 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 OCT 11 PY 2002 VL 47 IS 8 BP 557 EP 562 AR PII S1359-6462(02)00178-1 DI 10.1016/S1359-6462(02)00178-1 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 603DD UT WOS:000178542800011 ER PT J AU Jiang, JS Bader, SD AF Jiang, JS Bader, SD TI Magnetic reversal in thin film exchange-spring magnets SO SCRIPTA MATERIALIA LA English DT Article DE nanocrystalline materials; magnetic properties; soft magnets; hard magnets; nanocomposite ID PERMANENT-MAGNETS; ANISOTROPY; BEHAVIOR; BILAYERS AB Exchange-spring magnets based on the interfacial coupling of soft and hard ferromagnetic nanocomposites have the potential to outperform existing commercial permanent magnets. We present investigations of the magnetic reversal behavior in epitaxial thin film exchange-spring structures that consist of sputtered hard (Sm-Co) and soft (Fe, Co) magnetic layers. The results illustrate close correlations between the magnetic behavior and the microstructure and spin configuration of the hard layers. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Mat Sci Div 223, Argonne, IL 60439 USA. RP Bader, SD (reprint author), Argonne Natl Lab, Mat Sci Div 223, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 20 TC 9 Z9 11 U1 0 U2 7 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 OCT 11 PY 2002 VL 47 IS 8 BP 563 EP 568 AR PII S1359-6462(02)00179-3 DI 10.1016/S1359-6462(02)00179-3 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 603DD UT WOS:000178542800012 ER PT J AU Keller, SC Wood, PR AF Keller, SC Wood, PR TI Large magellanic cloud bump Cepheids: Probing the stellar mass-luminosity relation SO ASTROPHYSICAL JOURNAL LA English DT Article DE Cepheids; distance scale; magellanic clouds; stars : evolution; stars : oscillations ID OPAL OPACITIES; MODELS; STARS; ABUNDANCES; SUPERGIANTS; PHOTOMETRY; EVOLUTION; CLUSTERS; COLORS; DUST AB We present the results of nonlinear pulsation modeling of 20 bump Cepheids in the LMC. By obtaining an optimal fit to the observed V, R MACHO light curves, we have placed tight constraints on stellar parameters of M, L, and T-eff as well as quantities of distance modulus and reddening. We describe the mass-luminosity relation for core He burning for intermediate-mass stars. The mass-luminosity relation depends critically on the level of mixing within the stellar interior over the course of the main-sequence lifetime. Our sample is significantly more luminous than predicted by classical stellar evolutionary models that do not incorporate extension to the convective core. Under the paradigm of convective core overshoot, our data imply Lambda(c) of 0.65 +/- 0.03l/H-p. We derive a LMC distance modulus of 18.5+/-0.02. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2600, Australia. RP Keller, SC (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, L-413,POB 505, Livermore, CA 94550 USA. NR 46 TC 38 Z9 38 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2002 VL 578 IS 1 BP 144 EP 150 DI 10.1086/342315 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598XH UT WOS:000178301500014 ER PT J AU Salmonson, JD Wilson, JR AF Salmonson, JD Wilson, JR TI A model of short gamma-ray bursts: Heated neutron stars in close binary systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; gamma rays : bursts; gamma rays : theory; stars : neutron ID ANNIHILATION; FIREBALLS AB In this paper we present a model for the short (<1 s) population of gamma-ray bursts. In this model heated neutron stars in a close binary system near its last stable orbit emit a large amount of neutrinos (similar to 10(53) ergs). A fraction of these neutrinos will annihilate to form an e(+)e(-) pair plasma wind that will, in turn, expand and recombine to photons that make the gamma-ray burst. We study neutrino annihilation and show that a substantial fraction (similar to 1/2) of the energy deposited into e(+)e(-) pairs comes from interstar neutrinos, where each member of the neutrino pair originates from each neutron star. Thus, in addition to the annihilation of neutrinos blowing off of a single star, there is a new source of baryon-free plasma that is deposited between the stars. To model the e(+)e(-) pair plasma wind between stars, we do three-dimensional relativistic numerical hydrodynamic calculations. We find that the timescale for these bursts, deriving from the baryon-free plasma, is less than 1 s and that they will have a hot spectrum similar to 5 MeV. The energy in bursts is of the order of 10(52) ergs. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Salmonson, JD (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 16 TC 10 Z9 10 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2002 VL 578 IS 1 BP 310 EP 316 DI 10.1086/342311 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598XH UT WOS:000178301500026 ER PT J AU Fukuda, S Fukuda, Y Ishitsuka, M Itow, Y Kajita, T Kameda, J Kaneyuki, K Kobayashi, K Koshio, Y Miura, M Moriyama, S Nakahata, M Nakayama, S Okada, A Sakurai, N Shiozawa, M Suzuki, Y Takeuchi, H Takeuchi, Y Toshito, T Totsuka, Y Yamada, S Desai, S Kearns, E Messier, MD Stone, JL Sulak, LR Walter, CW Wang, W Goldhaber, M Casper, D Gajewski, W Kropp, WR Mine, S Liu, DW Smy, MB Sobel, HW Vagins, MR Ganezer, KS Keig, WE Ellsworth, RW Tasaka, S Kibayashi, A Learned, JG Matsuno, S Hayato, Y Ichikawa, A Ishii, T Kobayashi, T Maruyama, T Nakamura, K Obayashi, Y Oyama, Y Sakuda, M Yoshida, M Iwashita, T Kohama, M Suzuki, AT Inagaki, T Kato, I Nakaya, T Nishikawa, K Haines, TJ Dazeley, S Svoboda, R Blaufuss, E Goodman, JA Guillian, G Sullivan, GW Turcan, D Scholberg, K Habig, A Hill, J Jung, CK Martens, K Malek, M Mauger, C McGrew, C Sharkey, E Viren, B Yanagisawa, C Mitsuda, C Miyano, K Saji, C Shibata, T Kajiyama, Y Nagashima, Y Nitta, K Takita, M Kim, HI Kim, SB Yoo, J Okazawa, H Ishizuka, T Etoh, M Gando, Y Hasegawa, T Inoue, K Ishihara, K Nishiyama, I Shirai, J Suzuki, A Koshiba, M Ichikawa, Y Nishijima, K Fujiyasu, H Ishino, H Morii, M Watanabe, Y Kielczewska, D Stachyra, AL Wilkes, RJ AF Fukuda, S Fukuda, Y Ishitsuka, M Itow, Y Kajita, T Kameda, J Kaneyuki, K Kobayashi, K Koshio, Y Miura, M Moriyama, S Nakahata, M Nakayama, S Okada, A Sakurai, N Shiozawa, M Suzuki, Y Takeuchi, H Takeuchi, Y Toshito, T Totsuka, Y Yamada, S Desai, S Kearns, E Messier, MD Stone, JL Sulak, LR Walter, CW Wang, W Goldhaber, M Casper, D Gajewski, W Kropp, WR Mine, S Liu, DW Smy, MB Sobel, HW Vagins, MR Ganezer, KS Keig, WE Ellsworth, RW Tasaka, S Kibayashi, A Learned, JG Matsuno, S Hayato, Y Ichikawa, A Ishii, T Kobayashi, T Maruyama, T Nakamura, K Obayashi, Y Oyama, Y Sakuda, M Yoshida, M Iwashita, T Kohama, M Suzuki, AT Inagaki, T Kato, I Nakaya, T Nishikawa, K Haines, TJ Dazeley, S Svoboda, R Blaufuss, E Goodman, JA Guillian, G Sullivan, GW Turcan, D Scholberg, K Habig, A Hill, J Jung, CK Martens, K Malek, M Mauger, C McGrew, C Sharkey, E Viren, B Yanagisawa, C Mitsuda, C Miyano, K Saji, C Shibata, T Kajiyama, Y Nagashima, Y Nitta, K Takita, M Kim, HI Kim, SB Yoo, J Okazawa, H Ishizuka, T Etoh, M Gando, Y Hasegawa, T Inoue, K Ishihara, K Nishiyama, I Shirai, J Suzuki, A Koshiba, M Ichikawa, Y Nishijima, K Fujiyasu, H Ishino, H Morii, M Watanabe, Y Kielczewska, D Stachyra, AL Wilkes, RJ CA Super-Kamiokande Collaboration TI Search for neutrinos from gamma-ray bursts using Super-Kamiokande SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; neutrinos ID HIGH-ENERGY NEUTRINOS; FLUX; FIREBALLS; MUONS; AFTERGLOW AB Using the Super-Kamiokande neutrino observatory, a search was conducted for neutrinos produced in coincidence with gamma-ray bursts observed by the Burst and Transient Source Experiment detector. Super-Kamiokande data in the neutrino energy range of 7 MeV similar to100 TeV were analyzed. For gamma-ray bursts that occurred between 1996 April and 2000 May, no statistically significant signal in excess of the background levels was detected. Implied upper limits on associated gamma-ray burst neutrino production are presented. C1 Univ Tokyo, Inst Cosm Ray Res, Chiba 2778582, Japan. Boston Univ, Dept Phys, Boston, MA 02215 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Calif State Univ Dominguez Hills, Dept Phys, Carson, CA 90747 USA. George Mason Univ, Dept Phys, Fairfax, VA 22030 USA. Gifu Univ, Dept Phys, Gifu 5011193, Japan. Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. KEK, High Energy Accelerator Res Org, Inst Particle & Nucl Studies, Tsukuba, Ibaraki 3050801, Japan. Osaka Univ, Dept Phys, Osaka 5600043, Japan. Kobe Univ, Dept Phys, Kobe, Hyogo 6578501, Japan. Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87544 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Univ Minnesota, Dept Phys, Duluth, MN 55812 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Niigata Univ, Dept Phys, Niigata 9502181, Japan. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Shizuoka Seika Coll, Shizuoka 4258611, Japan. Shizuoka Univ, Dept Syst Engn, Shizuoka 4328561, Japan. Tohoku Univ, Res Ctr Neutrino Sci, Sendai, Miyagi 9808578, Japan. Univ Tokyo, Tokyo 1130033, Japan. Tokai Univ, Dept Phys, Kanagawa 2591292, Japan. Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Univ Tokyo, Inst Cosm Ray Res, Chiba 2778582, Japan. RI Takeuchi, Yasuo/A-4310-2011; Obayashi, Yoshihisa/A-4472-2011; Yoo, Jonghee/K-8394-2016; Nakamura, Kenzo/F-7174-2010; Sobel, Henry/A-4369-2011; Suzuki, Yoichiro/F-7542-2010; Martens, Kai/A-4323-2011; Wilkes, R.Jeffrey/E-6011-2013; Kim, Soo-Bong/B-7061-2014; Sakurai, Nobuyuki/M-5009-2014; Ishino, Hirokazu/C-1994-2015; Koshio, Yusuke/C-2847-2015; Kibayashi, Atsuko/K-7327-2015 OI Sakurai, Nobuyuki/0000-0002-1002-217X; Ishino, Hirokazu/0000-0002-8623-4080; Koshio, Yusuke/0000-0003-0437-8505; NR 29 TC 29 Z9 29 U1 0 U2 3 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 OCT 10 PY 2002 VL 578 IS 1 BP 317 EP 324 DI 10.1086/342405 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598XH UT WOS:000178301500027 ER PT J AU Fryer, CL Heger, A Langer, N Wellstein, S AF Fryer, CL Heger, A Langer, N Wellstein, S TI The limiting stellar initial mass for black hole formation in close binary systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; nuclear reactions, nucleosynthesis, abundances; supernovae : general; X-rays : binaries ID WOLF-RAYET STARS; CORE-COLLAPSE SUPERNOVAE; PRESUPERNOVA EVOLUTION; LOSS RATES; EXPLOSION; MODELS; PARAMETERS; BURSTS AB We present models for the complete life and death of a 60 M. star evolving in a close binary system, from the main-sequence phase to the formation of a compact remnant and fallback of supernova debris. After core hydrogen exhaustion, the star expands, loses most of its envelope by Roche lobe overflow, and becomes a Wolf-Rayet star. We study its post-mass transfer evolution as a function of the Wolf-Rayet wind mass-loss rate (which is currently not well constrained and will probably vary with the initial metallicity of the star). Varying this mass-loss rate by a factor of 6 leads to stellar masses at collapse that range from 3.1 up to 10.7 M.. Because of different carbon abundances left by core helium burning and nonmonotonic effects of the late shell-burning stages as function of the stellar mass, we find that, although the iron core masses at collapse are generally larger for stars with larger final masses, they do not depend monotonically on the final stellar mass or even the C/O core mass. We then compute the evolution of all models through collapse and bounce. The results range from strong supernova explosions (E-kin > 10(51) ergs) for the lower final masses to the direct collapse of the star into a black hole for the largest final mass. Correspondingly, the final remnant masses, which were computed by following the supernova evolution and fallback of material for a timescale of about one year, are between 1.2 and 10 M.. We discuss the remaining uncertainties of this result and outline the consequences of our results for the understanding of the progenitor evolution of X-ray binaries and X-ray burst models. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Astron Inst, NL-3508 TA Utrecht, Netherlands. Univ Potsdam, Inst Phys, D-14415 Potsdam, Germany. RP Fryer, CL (reprint author), Los Alamos Natl Lab, MS B288, Los Alamos, NM 87545 USA. EM fryer@lanl.gov NR 40 TC 29 Z9 29 U1 0 U2 6 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 OCT 10 PY 2002 VL 578 IS 1 BP 335 EP 347 DI 10.1086/342307 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598XH UT WOS:000178301500030 ER PT J AU Mauche, CW AF Mauche, CW TI Extreme Ultraviolet Explorer phase-resolved spectroscopy of V834 Centauri SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : individual (V834 Centauri); stars : magnetic fields; ultraviolet : stars; white dwarfs ID MAGNETIC CATACLYSMIC VARIABLES; AM-HERCULIS; X-RAY; RESONANCE SCATTERING; ACCRETION STREAM; SYSTEM E1405-451; WHITE-DWARF; LOW-STATE; CEN; POLARIMETRY AB The Extreme Ultraviolet Explorer (EUVE) satellite was employed for 5.46 days, beginning on 1999 February 9.03 UT, to acquire phase-resolved EUV photometric and spectroscopic observations of the AM Her type cataclysmic variable V834 Centauri. The resulting data are superior to those obtained by EUVE beginning on 1993 May 28.14 UT, because the source was approximately 3 times brighter, the observation was 4 times longer and dithered, and ASCA observed the source simultaneously. Although we do not understand the EUV light curves in detail, they are explained qualitatively by a simple model of accretion from a ballistic stream along the field lines of a tilted ([beta, psi] approximate to [10degrees, 40degrees]) magnetic dipole centered on the white dwarf. In 1993, when the EUV flux was lower, accretion was primarily along the phi approximate to psi approximate to 40degrees field line, whereas in 1999, when the EUV flux was higher, accretion took place over a broad range of azimuths extending from phi approximate to psi approximate to 40degrees to phi approximate to 76degrees. These changes in the accretion geometry could be caused by an increase in the mass accretion rate and/or the clumpiness of the flow. The 75-140 Angstrom EUVE spectra are well described by either a blackbody or a pure H stellar atmosphere absorbed by a neutral hydrogen column density, but constraints on the size of the EUV emission region and its UV brightness favor the blackbody interpretation. The mean 1999 EUV spectrum is best fitted by an absorbed blackbody with temperature kT approximate to 17.6 eV, hydrogen column density N-H approximate to 7.4 x 10(19) cm(-2), fractional emitting area f approximate to 10(-3), 70-140 Angstrom flux approximate to 3.0 x 10(-11) ergs cm(-2) s(-1), and luminosity L-soft approximate to 7.2 x 10(32) (d/100 pc)(2) ergs s(-1). The ratio of the EUV to X-ray luminosities is L-soft/Lw(hard) approximate to 40, signaling that some mechanism other than irradiation (e. g., blob heating) dominates energy input into the accretion spot. The 1999 short-wavelength (SW) hardness ratio variation can be explained by minor variations in kT and/or N-H, but instead of tracking the SW count rate variation, the hardness ratio variation was sinusoidal, with a minimum (maximum) when the accretion spot was on the near (far) side of the white dwarf, consistent with the trend expected for an atmosphere with an inverted temperature distribution. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mauche, CW (reprint author), Lawrence Livermore Natl Lab, L-43,7000 East Ave, Livermore, CA 94550 USA. NR 30 TC 5 Z9 5 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2002 VL 578 IS 1 BP 439 EP 449 DI 10.1086/342364 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598XH UT WOS:000178301500039 ER PT J AU Lepson, JK Beiersdorfer, P Brown, GV Liedahl, DA Utter, SB Brickhouse, NS Dupree, AK Kaastra, JS Mewe, R Kahn, SM AF Lepson, JK Beiersdorfer, P Brown, GV Liedahl, DA Utter, SB Brickhouse, NS Dupree, AK Kaastra, JS Mewe, R Kahn, SM TI Emission lines of Fe VII-Fe X in the extreme ultraviolet region, 60-140 angstrom SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : identification; methods : analytical; methods : laboratory; stars : coronae; ultraviolet : stars ID STELLAR CORONAL ABUNDANCES; COOL STARS; EUV SPECTROSCOPY; ALPHA-CENTAURI; SPECTRUM; PLASMAS AB We report on emission spectra of iron in the extreme ultraviolet recorded at an electron density of similar to5 x 10(11) cm(-3) at the Lawrence Livermore electron beam ion trap EBIT-II. We present a summary of observed emission lines, including wavelengths and emission intensities. We also illustrate our technique for isolating pure charge states of the desired ion and present spectra of pure Fe VII-Fe X. Our measurements add a large number of newly identified lines to existing line lists in the extreme-ultraviolet region, 60-140 Angstrom. While many of these lines are quite weak, they add up to a significant flux that can seriously affect interpretations of global fitting models, especially when applied to stars with material at the appropriate temperatures, such as Procyon, alpha Cen, and the Sun. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Div High Temp Phys, Livermore, CA 94550 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. RP Lepson, JK (reprint author), Univ Calif Berkeley, Space Sci Lab, Grizzly Peak & Centennial Dr, Berkeley, CA 94720 USA. NR 22 TC 48 Z9 48 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2002 VL 578 IS 1 BP 648 EP 656 DI 10.1086/342274 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598XH UT WOS:000178301500054 ER PT J AU Garimella, RV AF Garimella, RV TI Mesh data structure selection for mesh generation and FEA applications SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE mesh generation; data structures; tetrahedral and hexahedral meshes; grids; triangulation ID DELAUNAY TRIANGULATION AB The data structure representing a mesh and the operators to create and query such a database play a crucial role in the performance of mesh generation and FE analysis applications. The design of such a database must balance the conflicting requirements of compactness and computational efficiency. In this article, 10 different mesh representations are reviewed for linear tetrahedral and hexahedral meshes. A methodology for calculating the storage and computational costs of mesh representations is presented and the 10 data structures are analysed. Also, a system for ranking different data structures based on their computational and storage costs is devised and the various mesh representations are ranked according to this measure. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Garimella, RV (reprint author), Los Alamos Natl Lab, Div Theoret, T-7,POB 1663, Los Alamos, NM 87545 USA. NR 15 TC 17 Z9 18 U1 1 U2 2 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 OCT 10 PY 2002 VL 55 IS 4 BP 451 EP 478 DI 10.1002/nme.509 PG 28 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 591CF UT WOS:000177861600005 ER PT J AU Jackson, HE AF Jackson, HE TI Hermes and the spin of the proton SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Review DE lepton-nucleon scattering; spin asymmetries; polarized parton distributions ID VIRTUAL COMPTON-SCATTERING; DEEP-INELASTIC-SCATTERING; POLARIZED QUARK DISTRIBUTIONS; PARTON DISTRIBUTIONS; AZIMUTHAL ASYMMETRIES; NUCLEON SPIN; QCD ANALYSIS; BJORKEN-SUM; LEPTOPRODUCTION; DECOMPOSITION AB HERMES is a second generation experiment to study the spin structure of the nucleon, in which measurements of the spin dependent properties of semi-inclusive deep-inelastic lepton scattering are emphasized. Data have been accumulated for semi-inclusive pion, kaon, and proton double-spin asymmetries,. as well as for high-P-T hadron pairs, and single-spin azimuthal asymmetries for pion electroproduction and deep virtual Compton scattering. These results provide information on the flavor decomposition of the polarized quark distributions in the nucleon and a first glimpse of the gluon polarization, while the observation of the azimuthal asymmetries show,promise for probing the tensor spin of the nucleon and isolating the total angular momentum carried by the quarks. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Jackson, HE (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 51 TC 9 Z9 9 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD OCT 10 PY 2002 VL 17 IS 25 BP 3551 EP 3570 DI 10.1142/S0217751X02010923 PG 20 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 605EU UT WOS:000178665100001 ER PT J AU Alexander, FJ Garcia, AL Tartakovsky, DM AF Alexander, FJ Garcia, AL Tartakovsky, DM TI Algorithm refinement for stochastic partial differential equations. I. Linear diffusion SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID NAVIER-STOKES EQUATIONS; NONEQUILIBRIUM FLUIDS; COUPLING BOLTZMANN; LENGTH SCALES; SYSTEMS; SIMULATION; DYNAMICS AB A hybrid particle/continuum algorithm is formulated for Fickian diffusion in the fluctuating hydrodynamic limit. The particles are taken as independent random walkers; the fluctuating diffusion equation is solved by finite differences with deterministic and white-noise fluxes. At the interface between the particle and continuum computations the coupling is by flux matching, giving exact mass conservation. This methodology is an extension of Adaptive Mesh and Algorithm Refinement to stochastic partial differential equations. Results from a variety of numerical experiments are presented for both steady and time-dependent scenarios. In all cases the mean and variance of density are captured correctly by the stochastic hybrid algorithm. For a nonstochastic version (i.e., using only deterministic continuum fluxes) the mean density is correct, but the variance is reduced except in particle regions away from the interface. Extensions of the methodology to fluid mechanics applications are discussed. (C) 2002 Elsevier Science (USA). C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Alexander, FJ (reprint author), Los Alamos Natl Lab, CCS-3, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013 NR 22 TC 38 Z9 38 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT 10 PY 2002 VL 182 IS 1 BP 47 EP 66 DI 10.1006/jcph.2002.7149 PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 614HV UT WOS:000179183200003 ER PT J AU Azmy, YY AF Azmy, YY TI Unconditionally stable and robust adjacent-cell diffusive preconditioning of weighted-difference particle transport methods is impossible SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE iterative acceleration; diffusive preconditioners; neutral particle transport; unconditional; stability; robustness ID SYNTHETIC ACCELERATION METHODS; DISCRETE-ORDINATES EQUATIONS AB We construct a particle transport problem for which there exists no preconditioner with a cell-centered diffusion coupling stencil that is unconditionally stable and robust. In particular we consider an asymptotic limit of the periodic horizontal interface (PHI) configuration wherein the cell height in both layers approaches zero like sigma(2) while the total cross section vanishes like sigma in one layer and diverges like sigma(-1) as sigma --> 0 in the other layer. In such cases we show that the conditions for stability and robustness of the flat eigenmodes of the iteration residual imply instability of the modes flat in the y-dimension and rapidly varying in the x-dimension. Two assumptions are made in the proof. (i) Only cell-centered adjacent-cell preconditioners (AP) are considered; nevertheless numerical experiments with face-centered preconditioners of the diffusion synthetic acceleration (DSA) type on problem configurations with sharp material discontinuities suffer similar deterioration in spectral properties. (ii) The spatial weights of the arbitrarily high-order transport method of the nodal type and zeroth order (AHOT-N0) are used in the analysis; nevertheless similar results are expected for alternative spatial approximation methods as long as their spatial weights continuously approach the correct asymptotic limits: 0 and 1 for thin and thick cells, respectively. The result of the proof is verified by solving a finite approximation of PHI with three existing codes, two of which are not constrained by these assumptions. The spectral radii reported by the three codes behave as predicted by our analysis, i.e., reaching values that far exceed the maximum spectral radii determined via homogeneous model configuration analysis. This constitutes preliminary evidence that our conclusions might extend to a wider class of transport methods and acceleration schemes than is considered in the analysis. (C) 2002 Elsevier Science (USA). C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, POB 2008,MS 6363, Oak Ridge, TN 37831 USA. EM yya3@psu.edu NR 13 TC 12 Z9 12 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT 10 PY 2002 VL 182 IS 1 BP 213 EP 233 DI 10.1006/jcph.2002.7162 PG 21 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 614HV UT WOS:000179183200009 ER PT J AU Jamet, D Torres, D Brackbill, JU AF Jamet, D Torres, D Brackbill, JU TI On the theory and computation of surface tension: The elimination of parasitic currents through energy conservation in the second-gradient method SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID FRONT-TRACKING; INTERFACES; FLOWS; CAPILLARITY AB Errors in the computation of fluid flows with surface tension are examined. These errors cause large parasitic flows when the capillary number is large and have often been attributed to truncation error in underresolved interfacial regions. A study using the second-gradient method reveals that when truncation error is eliminated in the computation of energy exchanges between surface and kinetic energies so that energy is strictly conserved, the parasitic currents are reduced to round-off. The results are based on general thermodynamic arguments and can be used to guide improvements in other methods, such a the continuum-surface-force (CSF) method, which is commonly used with the volume-of-fluid (VOF) method. (C) 2002 Elsevier Science (USA). C1 Comis Nacl Energia Atom, Grenoble, France. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Jamet, D (reprint author), Comis Nacl Energia Atom, Grenoble, France. NR 18 TC 94 Z9 94 U1 3 U2 21 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT 10 PY 2002 VL 182 IS 1 BP 262 EP 276 DI 10.1006/jcph.2002.7165 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 614HV UT WOS:000179183200011 ER PT J AU Fischer, PF Leaf, GK Restrepo, JM AF Fischer, PF Leaf, GK Restrepo, JM TI Forces on particles in oscillatory boundary layers SO JOURNAL OF FLUID MECHANICS LA English DT Article ID LINEAR SHEAR-FLOW; FINITE REYNOLDS-NUMBER; CONTINENTAL-SHELF; INERTIAL LIFT; SPHERE; TRANSPORT; DRAG; WALL AB The lift and drag forces on an isolated particle resulting from an oscillating wall-bounded flow, are approximated using direct numerical simulation and extrapolation techniques. We also confirm the existence of anomalies in the lift force, which arise from the interaction of the vortical field with the particle. Anomalies can also occur for computational reasons and these are discussed as well. This study was motivated by a long-standing question about the importance of lift forces in the dynamics of sediments in oceanic settings. To answer this question we use the numerically generated data as well as extrapolations to compute the ratio of the lift to buoyancy forces on a particle. This analysis suggests that for particles and oceanic conditions typical of the nearshore, the lift force can play a role in the dynamics of sedimentary beds. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Arizona, Dept Math, Tucson, AZ 85721 USA. Univ Arizona, Program Appl Math, Tucson, AZ 85721 USA. RP Fischer, PF (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Restrepo, Juan/0000-0003-2609-2882 NR 34 TC 14 Z9 15 U1 0 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD OCT 10 PY 2002 VL 468 BP 327 EP 347 DI 10.1017/S0022112002001234 PG 21 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 606JT UT WOS:000178731400013 ER PT J AU Grabowski, P Riccardi, D Gomez, MA Asthagiri, D Pratt, LR AF Grabowski, P Riccardi, D Gomez, MA Asthagiri, D Pratt, LR TI Quasi-chemical theory and the standard free energy of H+(aq) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID INITIO MOLECULAR-DYNAMICS; VALENCE-BOND MODEL; SOLVATION FREE-ENERGY; LIQUID WATER; AQUEOUS-SOLUTION; PROTON MOTION; EXCESS PROTON; THERMODYNAMICS; EQUILIBRIUM; SIMULATIONS AB Quasi-chemical theory and electronic structure results on inner-sphere H(H2O)(n)(+) clusters are used to discuss the absolute hydration free energy of H+(aq). It is noted that this quantity is not thermodynamically measurable, and this leads to some relative misalignment of available tables of absolute hydration free energies of ions in water. The simplest quasi-chemical model produces a reasonable quantitative result in the range of -256 to -251 kcal/mol. The primitive concepts on which the model is based naturally identify the Zundel cation H5O2+ as the principal chemical structure contributing to this hydration free energy. The specific participation of an Eigen cation H9O4+ is not required in this model because the definition of that structure depends on outer-sphere arrangements, and a crude dielectric continuum model is here used for outer-sphere contributions. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Vassar Coll, Dept Chem, Poughkeepsie, NY 12601 USA. RP Pratt, LR (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Asthagiri, Dilipkumar/A-3383-2010; Pratt, Lawrence/H-7955-2012; Asthagiri, Dilipkumar/P-9450-2016 OI Pratt, Lawrence/0000-0003-2351-7451; Asthagiri, Dilipkumar/0000-0001-5869-0807 NR 40 TC 42 Z9 42 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 OCT 10 PY 2002 VL 106 IS 40 BP 9145 EP 9148 DI 10.1021/jp026291a PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602LL UT WOS:000178506700001 ER PT J AU Hathorn, BC Sumpter, BG Noid, DW Tuzun, RE Yang, C AF Hathorn, BC Sumpter, BG Noid, DW Tuzun, RE Yang, C TI Vibrational normal modes of polymer nanoparticle dimers using the time-averaged normal coordinate analysis method SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MOLECULAR MECHANICS CALCULATIONS; COMPOSITE MICROPARTICLES; MACROMOLECULAR SYSTEMS; BLEND MICROPARTICLES; DYNAMICS SIMULATIONS; OPTICAL DIFFRACTION; THERMAL-PROPERTIES; REFRACTIVE-INDEX; NANO-PARTICLES; SIZE AB The recently developed time-averaged normal coordinate analysis method is employed to investigate the normal modes of polymer nanoparticle dimers. In addition to providing the first accurate calculation of vibrational frequencies and vibrational displacements in dimerized nanoparticles, the normal mode corresponding to the particle dimer vibration is observed for the first time. It is observed that the nanoparticle dimer vibration is only minimally coupled to the other internal motions of the particle, showing a true correspondence to the vibrational motion in diatomic species. Several other characteristic vibrations of the dimerized species are observed, which cot-respond to coupled indifferent modes of the monomer particles. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. SUNY Coll Brockport, Dept Computat Sci, Brockport, NY 14420 USA. Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. RP Hathorn, BC (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 41 TC 4 Z9 4 U1 0 U2 0 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 OCT 10 PY 2002 VL 106 IS 40 BP 9174 EP 9180 DI 10.1021/jp013584f PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602LL UT WOS:000178506700004 ER PT J AU Barrow, JA Sordelet, DJ Besser, MF Jenks, CJ Thiel, PA Rexer, EF Riley, SJ AF Barrow, JA Sordelet, DJ Besser, MF Jenks, CJ Thiel, PA Rexer, EF Riley, SJ TI Analysis of gas-phase clusters made from laser-vaporized icosahedral Al-Pd-Mn SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ELECTRONIC SHELL STRUCTURE; QUASI-CRYSTALS; NICKEL CLUSTERS AB An icosahedral Al-Pd-Mn quasicrystal sample is laser vaporized to form metal clusters by gas aggregation. The clusters are subsequently laser ionized and mass analyzed in a time-of-flight mass spectrometer. The mass spectra show cluster compositions which are qualitatively similar to that of the sample. This is consistent with a kinetically controlled cluster growth process. Cluster thermodynamic stability is probed by multiphoton ionization/fragmentation, which induces primarily Al and Mn loss. The resulting spectra are composed of a series of Pd-rich Al-Pd clusters. The average cluster composition is 60 (+/-1)% Pd. This composition is close to a known eutectic in the Al-Pd system. When manganese is seen on these clusters, it is always in units of Mn(3). These results are discussed in terms of relative binding strengths in the Al-Pd-Mn alloy system. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Thiel, PA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. EM thiel@ameslab.gov NR 21 TC 7 Z9 7 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 10 PY 2002 VL 106 IS 40 BP 9204 EP 9208 DI 10.1021/jp025662k PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602LL UT WOS:000178506700008 ER PT J AU Klippenstein, SJ Miller, JA AF Klippenstein, SJ Miller, JA TI From the time-dependent, multiple-well master equation to phenomenological rate coefficients SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID REVERSIBLE ISOMERIZATION; ELEMENTARY REACTIONS; THEORETICAL-ANALYSIS; MOLECULAR-OXYGEN; DECOMPOSITION; RECOMBINATION; ACTIVATION; COMBUSTION; PROPARGYL; MECHANISM AB We discuss at some length the relationship between solutions to the time-dependent, multiple-well master equation and a macroscopic description of the chemistry in terms of phenomenological rate coefficients. In so doing, we derive two different methods of obtaining the rate coefficients from the eigenvalues and eigenvectors of G, the transition matrix of the master equation. We apply the first of the two methods to the C2H3 + C2H2 and C3H3 + C3H3 reactions, problems we have treated previously using the "experimental" (or exponential-decay) approach, and obtain considerably more and somewhat different results than we obtained in our earlier work. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Miller, JA (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. OI Klippenstein, Stephen/0000-0001-6297-9187 NR 28 TC 94 Z9 95 U1 0 U2 26 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 OCT 10 PY 2002 VL 106 IS 40 BP 9267 EP 9277 DI 10.1021/jp021175t PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 602LL UT WOS:000178506700017 ER PT J AU Dang, LX AF Dang, LX TI Computational study of ion binding to the liquid interface of water SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR-DYNAMICS; VAPOR INTERFACE; SIMULATIONS; MEMBRANES; CHEMISTRY; CLUSTERS AB We have performed extensive classical molecular dynamics simulations to examine the molecular transport mechanisms of I-, Br-, Cl-, and Na+ ions across the liquid/vapor interface of water. The potentials of mean force were calculated using the constrained mean force approach and polarizable potential models were used to describe the interactions among the species. The simulated potentials of mean force were found to be different,. depending on the type of anion. The larger I- and Br- anions bind more strongly to the liquid/ vapor interface of water than that of the smaller Cl- ion. It is important to note that most of the gas phase and solution phase properties of the Br- anion are quite similar to that of the Cl- ion. At the interface, however, the interactions of the Br- and Cl- anions with the water interface appeared to be significantly different. We found that the anions approach the interface more closely than cations. We have also studied the transport mechanism of an I- across the water/dichloromethane interface. The computed potential of mean force showed no Well-defined minimum as in the liquid/vapor case, but a stabilization free energy of about -1 kcal/mol near the interface with respect to the bulk liquid was observed. The I- anion carried a water molecule with it as it crossed the interface. This result is in agreement with a recent experimental study on a similar system. Our work differs from earlier contributions in that our potential models have taken many-body effects into account, and in some cases, these effects cannot be neglected. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dang, LX (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 24 TC 175 Z9 176 U1 2 U2 30 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 OCT 10 PY 2002 VL 106 IS 40 BP 10388 EP 10394 DI 10.1021/jp021871t PG 7 WC Chemistry, Physical SC Chemistry GA 602LN UT WOS:000178506900017 ER PT J AU Wang, J Feldberg, SW Bard, AJ AF Wang, J Feldberg, SW Bard, AJ TI Measurement of double-layer forces at the polymer film/electrolyte interfaces using atomic force microscopy: Concentration and potential-dependent interactions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; DIFFUSE DOUBLE-LAYER; ELECTRODE/ELECTROLYTE INTERFACE; SURFACE FORCES; DNA IMMOBILIZATION; CHARGE; FILMS; ELECTRODES; MICA; ACID AB The forces between colloidal probes and several polymer films were measured by atomic force microscopy in the presence of a series of electrolyte solutions. For Nafion films using a negatively charged silica tip, a repulsive force was obtained at different concentrations of NaClO4. A similar result was obtained for an anion exchange membrane with a positively charged probe. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory was employed to calculate the surface potential and hence, the surface charge. The surface charge density (similar to0.3muC/cm(2)) was independent of electrolyte concentration. The slope for plot of potential drop vs ln[c(5)] was similar to0.020 V. A theoretical treatment based on GCS theory was employed to account for the above results. For a poly,(vinylferrocene), (PVF) film, potenial-dependent force curves were obtained, which were qualitatively different from that previously reported for an electronically conducting polymer film electrode.(1). C1 Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bard, AJ (reprint author), Boston Univ, Dept Chem, 590 Commonwealth Ave, Boston, MA 02215 USA. NR 41 TC 15 Z9 15 U1 4 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 10 PY 2002 VL 106 IS 40 BP 10440 EP 10446 DI 10.1021/jp026350k PG 7 WC Chemistry, Physical SC Chemistry GA 602LN UT WOS:000178506900024 ER PT J AU Liu, YG Daum, PH AF Liu, YG Daum, PH TI Anthropogenica erosols - Indirect warming effect from dispersion forcing SO NATURE LA English DT Article ID CLOUD SUSCEPTIBILITY; EFFECTIVE RADIUS; MARINE STRATUS; PARAMETERIZATION; AEROSOLS; CONTRASTS; CLIMATE; ALBEDO; TRACKS C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Liu, YG (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Liu, Yangang/H-6154-2011 NR 15 TC 108 Z9 112 U1 2 U2 18 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 10 PY 2002 VL 419 IS 6907 BP 580 EP 581 DI 10.1038/419580a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 602AT UT WOS:000178483100033 PM 12374969 ER PT J AU Yasui, D Miyano, M Cai, ST Varga-WEisz, P Kohwi-Shigematsu, T AF Yasui, D Miyano, M Cai, ST Varga-WEisz, P Kohwi-Shigematsu, T TI SATB1 targets chromatin remodelling to regulate genes over long distances SO NATURE LA English DT Article ID CELL-SPECIFIC DEMETHYLATION; MATRIX ATTACHMENT REGIONS; DNA-BINDING PROTEIN; NUCLEAR MATRIX; HISTONE DEACETYLASE; CHAIN ENHANCER; IN-VIVO; COMPLEX; SEQUENCES; ACETYLATION AB Eukaryotic chromosomes are organized inside the nucleus in such a way that only a subset of the genome is expressed in any given cell type, but the details of this organization are largely unknown(1-3). SATB1 ('special AT-rich sequence binding 1'), a protein found predominantly in thymocytes(4), regulates genes by folding chromatin into loop domains, tethering specialized DNA elements to an SATB1 network structure(5). Ablation of SATB1 by gene targeting results in temporal and spatial mis-expression of numerous genes and arrested T-cell development, suggesting that SATB1 is a cell-type specific global gene regulator(6). Here we show that SATB1 targets chromatin remodelling to the IL-2Ralpha ('interleukin-2 receptor alpha') gene, which is ectopically transcribed in SATB1 null thymocytes. SATB1 recruits the histone deacetylase contained in the NURD chromatin remodelling complex to a SATB1-bound site in the IL-2Ralpha locus, and mediates the specific deacetylation of histones in a large domain within the locus. SATB1 also targets ACF1 and ISWI, subunits of CHRAC and ACF nucleosome mobilizing complexes, to this specific site and regulates nucleosome positioning over seven kilobases. SATB1 defines a class of transcriptional regulators that function as a 'landing platform' for several chromatin remodelling enzymes and hence regulate large chromatin domains. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Marie Curie Res Inst, Surrey RH8 OTL, England. RP Kohwi-Shigematsu, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RI MIYANO, MASARU/I-1353-2015 FU NIA NIH HHS [AG00266] NR 30 TC 289 Z9 307 U1 0 U2 11 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 10 PY 2002 VL 419 IS 6907 BP 641 EP 645 DI 10.1038/nature01084 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 602AT UT WOS:000178483100051 PM 12374985 ER PT J AU Kusenko, A Postma, M AF Kusenko, A Postma, M TI Neutrino production in matter with time-dependent density or velocity SO PHYSICS LETTERS B LA English DT Article ID GAMMA-RAY BURSTS; HIGH-ENERGY NEUTRINOS; FIREBALLS; FERMIONS AB We show that neutrinos can be produced through standard electroweak interactions in matter with time-dependent density. (C) 2002 Published by Elsevier Science B.V. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Kusenko, A (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NR 19 TC 11 Z9 12 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 OCT 10 PY 2002 VL 545 IS 3-4 BP 238 EP 243 AR PII S0370-2693(02)02619-9 DI 10.1016/S0370-2693(02)02619-9 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606UG UT WOS:000178751800006 ER PT J AU Chekanov, S Krakauer, D Magill, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Margotti, A Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Crittenden, J Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Renner, R Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Topper, RJ Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Paganis, S Schmidke, W Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Poitrzkowski, K Przybycien, MB Stopa, P Zawiejski, L Adamczyk, L Bednarek, B Grabowska-Bold, I Jelen, K Kisielewska, D Kowal, AM Kowal, M Kowalski, T Mindur, B Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W Bauerdick, LAT Behrens, U Borras, K Chiochia, V Dannheim, D Derrick, M Drews, G Fourletova, J Fox-Murphy, A Fricke, U Geiser, A Goebel, F Gottlicher, P Gutsche, O Haas, T Hain, W Hartner, GF Hillert, S Kotz, U Kowalski, H Labes, H Lelas, D Lohr, B Mankel, R Martinez, M Moritz, M Notz, D Pellmann, IA Petrucci, MC Polini, A Raval, A Schneekloth, U Selonke, F Surrow, B Wessoleck, H Wichmann, R Wolf, G Youngman, C Zeuner, W Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Raach, H Bell, M Bussey, PJ Doyle, AT Glasman, C Hanlon, S Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Gialas, I Bodmann, B Carli, T Holm, U Klimek, K Krumnack, N Lohrmann, E Milite, M Salehi, H Stonjek, S Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Kuze, M Nagano, K Tokushuka, K Yamada, S Yamazaki, Y Barakbaev, A Boos, EG Pokrovskiy, NS Zhautykov, BO Lim, H Son, D Barreiro, F Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Ochs, A Padhi, S Stairs, DG St-Laurent, M Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, R Golubkov, YA Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Koffeman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Bruummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grzelak, G Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Heaphy, EA Oh, BY Sau, PRB Whitmore, JJ Iga, Y D'Agostini, GD Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, SS Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Jones, TW Lane, JB Lightwood, MS Loizides, JH West, BJ Ciborowski, J Ciesielski, R Nowak, RJ Pawlak, JM Smalska, B Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zakrzewski, JA Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Kcira, D Lammers, S Li, L Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, V Straub, P Bhadra, S Catterall, CD Fourletov, S Menary, S Soares, M Standage, J AF Chekanov, S Krakauer, D Magill, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Margotti, A Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Crittenden, J Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Renner, R Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Topper, RJ Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Kim, JY Kim, YK Lee, JH Lim, IT Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Paganis, S Schmidke, W Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Poitrzkowski, K Przybycien, MB Stopa, P Zawiejski, L Adamczyk, L Bednarek, B Grabowska-Bold, I Jelen, K Kisielewska, D Kowal, AM Kowal, M Kowalski, T Mindur, B Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W Bauerdick, LAT Behrens, U Borras, K Chiochia, V Dannheim, D Derrick, M Drews, G Fourletova, J Fox-Murphy, A Fricke, U Geiser, A Goebel, F Gottlicher, P Gutsche, O Haas, T Hain, W Hartner, GF Hillert, S Kotz, U Kowalski, H Labes, H Lelas, D Lohr, B Mankel, R Martinez, M Moritz, M Notz, D Pellmann, IA Petrucci, MC Polini, A Raval, A Schneekloth, U Selonke, F Surrow, B Wessoleck, H Wichmann, R Wolf, G Youngman, C Zeuner, W Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Raach, H Bell, M Bussey, PJ Doyle, AT Glasman, C Hanlon, S Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Gialas, I Bodmann, B Carli, T Holm, U Klimek, K Krumnack, N Lohrmann, E Milite, M Salehi, H Stonjek, S Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Kuze, M Nagano, K Tokushuka, K Yamada, S Yamazaki, Y Barakbaev, A Boos, EG Pokrovskiy, NS Zhautykov, BO Lim, H Son, D Barreiro, F Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Ochs, A Padhi, S Stairs, DG St-Laurent, M Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, R Golubkov, YA Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Koffeman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Bruummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grzelak, G Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Heaphy, EA Oh, BY Sau, PRB Whitmore, JJ Iga, Y D'Agostini, GD Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, SS Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Jones, TW Lane, JB Lightwood, MS Loizides, JH West, BJ Ciborowski, J Ciesielski, R Nowak, RJ Pawlak, JM Smalska, B Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zakrzewski, JA Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Kcira, D Lammers, S Li, L Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, V Straub, P Bhadra, S Catterall, CD Fourletov, S Menary, S Soares, M Standage, J CA ZEUS Collaboration TI Measurement of diffractive production of D(*+/-) (2010) mesons in deep-inelastic scattering at HERA SO PHYSICS LETTERS B LA English DT Article ID CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; OPEN CHARM PRODUCTION; LARGE RAPIDITY GAP; REAR CALORIMETER; CROSS-SECTIONS; EP SCATTERING; DISSOCIATION; DIS; CONSTRUCTION AB Diffractive production of D(*+/-)(2010) mesons in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 44.3 pb(-1). Diffractive charm production is identified by the presence of a large rapidity gap in the final state of events in which a D(*+/-) (2010) meson is reconstructed in the decay channel D(*+/-) --> (D(0) --> K(-)pi(+))pi(s)(+) (+ charge conjugate). Differential cross sections when compared with theoretical predictions indicate the importance of gluons in such diffractive interactions. (C) 2002 Elsevier Science B.V All rights reserved. C1 Andrews Univ, Berrien Springs, MI 49104 USA. Univ Bologna, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, New York, NY 10027 USA. Inst Nucl Phys, Krakow, Poland. Univ Min & Met Krakow, Fac Phys & Nucl Tech, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. Deutsch Elektron Synchrotron, DESY, Hamburg, Germany. DESY Zeuthen, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Freiburg, Fac Phys, Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Aegean, Dept Engn Management & Finance, Aegean, Greece. Univ Hamburg, Inst Expt Phys, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, Hign Energy Nucl Phys Grp, London, England. Forschungszentrum Julich, Inst Kernphys, Julich, Germany. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Kazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Kyungpook Natl Univ, Taegu 702701, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Engn Phys Inst, Moscow 115409, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. NIKHEF H, Amsterdam, Netherlands. Univ Amsterdam, Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, I-35100 Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Seoul Natl Univ, Seoul, South Korea. Univ Siegen, Fachbereich Phys, D-5900 Siegen, Germany. Tel Aviv Univ, Sch Phys, Raymond & Beverly Sackler Fac Exact Sci, Tel Aviv, Israel. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Univ Turin, Dipartimento Fis Sperimentale, Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. UCL, Dept Phys & Astron, London, ON, Canada. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. York Univ, Dept Phys, N York, ON M3J 1P3, Canada. Univ Piemonte Orientale, Novara, Italy. Univ Lodz, PL-90131 Lodz, Poland. RP Chekanov, S (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; Suchkov, Sergey/M-6671-2015; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Li, Liang/O-1107-2015; Capua, Marcella/A-8549-2015; Ferrando, James/A-9192-2012; Golubkov, Yury/E-1643-2012; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Levchenko, B./D-9752-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; collins-tooth, christopher/A-9201-2012 OI Gladilin, Leonid/0000-0001-9422-8636; dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Li, Liang/0000-0001-6411-6107; Capua, Marcella/0000-0002-2443-6525; Longhin, Andrea/0000-0001-9103-9936; Gutsche, Oliver/0000-0002-8015-9622; Ferrando, James/0000-0002-1007-7816; De Pasquale, Salvatore/0000-0001-9236-0748; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Doyle, Anthony/0000-0001-6322-6195; NR 71 TC 9 Z9 9 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 OCT 10 PY 2002 VL 545 IS 3-4 BP 244 EP 260 AR PII S0370-2693(02)02595-9 DI 10.1016/S0370-2693(02)02595-9 PG 17 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606UG UT WOS:000178751800007 ER PT J AU Stevenson, PD Stone, JR Strayer, MR AF Stevenson, PD Stone, JR Strayer, MR TI Mean field calculation of Ne, Mg and Si nuclei at N=20 with the separable monopole interaction SO PHYSICS LETTERS B LA English DT Article DE shell closures; separable interaction; mean-field ID NEUTRON-RICH NUCLEI; SHELL-MODEL; PROJECTILE FRAGMENTATION; QUADRUPOLE COLLECTIVITY; ANGULAR-MOMENTUM; SODIUM ISOTOPES; MONTE-CARLO; DRIP-LINE; DEFORMATION; SI-32,SI-34,SI-36,SI-38 AB A new model has been developed to study nuclei using many-body perturbation theory with a density dependent separable monopole nucleon-nucleon interaction (SMO) [Phys. Rev. C 63 (2001) 054309; P.D. Stevenson, D.Ph. Thesis, Oxford 1999; Phys. Rev. C 65 (2002) 064312]. The model is in the zeroth order an alternative to mean-field models based on more conventional effective nucleon-nucleon interactions (e.g., Skyrme, Gogny). Results on shapes and related ground state observables are reported for even-even Ne, Mg, and Si nuclei with N similar to 20. The model predicts the weakening of the expected N = 20 shell closure in Ne isotopes and its disappearance in Mg nuclei in full agreement with experimental results. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Stevenson, PD (reprint author), Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England. RI Stevenson, Paul/B-9016-2012 OI Stevenson, Paul/0000-0003-2645-2569 NR 38 TC 21 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 10 PY 2002 VL 545 IS 3-4 BP 291 EP 297 AR PII S0370-2693(02)02634-5 DI 10.1016/S0370-2693(02)02634-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606UG UT WOS:000178751800011 ER PT J AU Kharzeev, D Krasnitz, A Venugopalan, R AF Kharzeev, D Krasnitz, A Venugopalan, R TI Anomalous chirality fluctuations in the initial stage of heavy ion collisions and parity odd bubbles SO PHYSICS LETTERS B LA English DT Article DE anomaly; lattice simulations; sphalerons ID NUCLEUS-NUCLEUS COLLISIONS; SPHALERON TRANSITION RATE; QUASI-CLASSICAL APPROXIMATION; WILSON RENORMALIZATION-GROUP; GLUON DISTRIBUTION-FUNCTIONS; ABELIAN GAUGE-FIELDS; FINITE-TEMPERATURE; SMALL-X; TRANSVERSE-MOMENTUM; EFFECTIVE DYNAMICS AB We compute numerically the topological charge distribution in the initial stage of a high energy heavy ion collision. This charge distribution is generated by Chem-Simons number fluctuations associated with the dynamics of strong classical fields in the initial state. The distribution is found to be quite narrow at RHIC and LHC energies; we argue that this is a consequence of the strict boost invariance of the initial field configurations. A substantial generation of topological charge, as required in the P-odd bubble scenario [D. Kharzeev, et al., Phys. Rev. Lett. 81 (1998) 512], can only occur if strict boost invariance is lost in the later stages of the collision. This could be naturally achieved if the system approaches thermalization. (C) 2002 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Algarve, CENTRA, P-8000 Faro, Portugal. Univ Algarve, Fac Ciencias & Tecnol, P-8000 Faro, Portugal. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM kharzeev@bnl.gov; krasnitz@ualg.pt; raju@bnl.gov NR 81 TC 74 Z9 74 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 OCT 10 PY 2002 VL 545 IS 3-4 BP 298 EP 306 AR PII s0370-2693(02)02630-8 DI 10.1016/S0370-2693(02)02630-8 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606UG UT WOS:000178751800012 ER PT J AU Cooper, F Savage, VM AF Cooper, F Savage, VM TI Dynamics of the chiral phase transition in the (2+1)-dimensional Gross-Neveu model SO PHYSICS LETTERS B LA English DT Article ID 4-FERMION INTERACTION; SYMMETRY-BREAKING; DENSITY AB The phase diagram of the Gross-Neveu (GN) model in 2 + 1 dimensions as a function of chemical potential and temperature has a simple curve separating the broken symmetry and unbroken symmetry phases, with chiral symmetry being restored both at high temperature and high density. We study, in leading order in the 1/N expansion, the dynamics of the chiral phase transition for an expanding plasma of quarks in the Gross-Neveu model in 2 + 1 dimensions assuming boost invariant kinematics. We compare the time evolution of the order parameter (mass of the fermion) for evolutions starting in the unbroken and broken phases. The proper time evolution of the order parameter resembles previous results in the (1 + 1)-dimensional GN model in the same approximation. The time needed to traverse the transition is insensitive to mu. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Cooper, F (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663,T-8, Los Alamos, NM 87545 USA. NR 12 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 10 PY 2002 VL 545 IS 3-4 BP 307 EP 314 AR PII S0370-2693(02)02597-2 DI 10.1016/S0370-2693(02)02597-2 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606UG UT WOS:000178751800013 ER PT J AU Roberts, JG Van Hove, MA Somorjai, GA AF Roberts, JG Van Hove, MA Somorjai, GA TI Surface structural analysis of LiF(100) thin films grown on Pt(111) SO SURFACE SCIENCE LA English DT Article DE low energy electron diffraction (LEED); alkali halides; single crystal surfaces; low index single crystal surfaces; insulating films ID ENERGY-ELECTRON-DIFFRACTION; LEED; CRYSTALLOGRAPHY; MONOLAYER AB The surface structure of a multilayer LiF(1 0 0) thin film grown on Pt(1 1 1) from the vapor has been determined by the automated tensor low energy electron diffraction method. The final structure, which refined to a Pendry R-factor (R-p) of 0.24, had a surface corrugation (Delta(1)) of 0.24 +/- 0.04 Angstrom due to the Li+ being displaced towards the bulk, leaving the initially coplanar F- unshifted. A similar intralayer corrugation due to the movement of the Li+ was also observed in the layer immediately under the surface layer, although to a lesser degree: Delta(2) = 0.07 +/- 0.04 Angstrom. This asymmetric relaxation resulted in the reduction of the first interlayer spacing, d(F-2-Li-1), to 1.77 +/- 0.06 Angstrom from the ideal value of 2.01 Angstrom. The second interlayer spacing, d(Li-3-F-2) was within error bars of the bulk value, 2.01 Angstrom. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd,Mailstop 2-100, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 20 TC 16 Z9 16 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 10 PY 2002 VL 518 IS 1-2 BP 49 EP 56 AR PII S0039-6028(02)02091-5 DI 10.1016/S0039-6028(02)02091-5 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 604WC UT WOS:000178643200007 ER PT J AU Gomez-Balderas, R Oviedo-Roa, R Martinez-Magadan, JM Amador, C Dixon, DA AF Gomez-Balderas, R Oviedo-Roa, R Martinez-Magadan, JM Amador, C Dixon, DA TI A comparative DFT study of the catalytic activity of the 3d transition metal sulphides surfaces SO SURFACE SCIENCE LA English DT Article DE catalysis; sulphides ID HYDRODESULFURIZATION CATALYSTS; ELECTRONIC-STRUCTURE; DENSITY; MOS2; THIOPHENE; HYDROGEN; SULFUR; CARBON; HDS; NI AB The catalytic activity of the first transition metal series sulphides for hydrodesulfurization (HDS) reactions exhibits a particular behaviour when analysed as a function of the metal position in the Periodic Table. This work reports a comparative study of the electronic structure of the bulk and of the (0 0 1) metal surface (assumed to be the reactive surface) for the Sc-Zn monosulphides. The systems Were modelled using the NiAs prototype crystal structure for the bulk and by applying the supercell model with seven atomic layers for the (0 0 1) surfaces. The electronic structure of closed-packed solids code based on the density-functional theory and adopting the muffin-tin approximation to the potential was employed in the calculations of the electronic properties. For the Co and Ni sulphides, the density of states (DOS) variations between the metal atom present in the bulk and the ones exposed at the surface show that at the surface, there exists a higher DOS in the occupied states region just below the Fermi level. This feature might indicate a good performance of these two metal sulphides as substrates in the HDS reactions favouring a donation, back-donation mechanism. In contrast, the DOS at the surface of Mn is increased in the unoccupied states region, just above the Fermi level. This suggests the possibility of a strong interaction with charge donating sulphur adsorbate atoms poisoning the active substrate surface. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Inst Mexicano Petr, Programa Ingn Mol, Mexico City 07730, DF, Mexico. Univ Nacl Autonoma Mexico, Dept Fis & Quim Teor, Mexico City 04510, DF, Mexico. Fac Estudios Super Cuautitlan, Dept Ciencias Quim Fisicoquim, Cuautitlan 54740, Mexico. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Inst Mexicano Petr, Programa Ingn Mol, Eje Cent Lazaro Cardenas 152, Mexico City 07730, DF, Mexico. EM mmartine@www.imp.mx RI Amador-Bedolla, Carlos/E-7448-2010; Martinez-Magadan, Jose-Manuel/M-1973-2015 OI Amador-Bedolla, Carlos/0000-0001-9590-2645; Martinez-Magadan, Jose-Manuel/0000-0003-1152-6924 NR 35 TC 9 Z9 9 U1 6 U2 34 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD OCT 10 PY 2002 VL 518 IS 1-2 BP 163 EP 173 AR PII S0039-6028(02)02123-4 DI 10.1016/S0039-6028(02)02123-4 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 604WC UT WOS:000178643200018 ER PT J AU de Arellano-Lopez, AR Melendez-Martinez, JJ Cruse, TA Koritala, RE Routbort, JL Goretta, KC AF de Arellano-Lopez, AR Melendez-Martinez, JJ Cruse, TA Koritala, RE Routbort, JL Goretta, KC TI Compressive creep of mullite containing Y2O3 SO ACTA MATERIALIA LA English DT Article DE creep; microstructure; structural ceramics ID SOLUTION-PRECIPITATION CREEP; BOUNDARY GLASS PHASE; SILICON-NITRIDE; POLYCRYSTALLINE MULLITE; MECHANICAL-PROPERTIES; SELF-DIFFUSION; LIQUID-PHASE; CERAMICS; DEFORMATION; BEHAVIOR AB Compressive creep of mullite and mullite containing 5 and 9 wt% Y2O3 has been investigated in the temperature range of 1300-1400 degreesC over stresses between approximate to0.6 and 40 MPa in air. The nominally single-phase mullite deforms by diffusional flow with a stress exponent of 1 (for higher stresses) and an activation energy of 385 200/mol. It is likely that the rate-controlling diffusing species is oxygen. Creep of the Y2O3-containingspecimens was similar to that of the pure mullite at 1300 degreesC. Near and above the temperature at which melting was observed in DTA, the Y2O3-containing specimens crept significantly faster than the pure mullite. Models of creep of materials that contain a glass phase can explain most, but not all, of the observed behavior. Creep rates were not significantly affected by partial crystallization of the glass to Y2Si2O7, but the crystallized specimens exhibited cavitation at larger strains. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Seville, Dept Fis Mat Condensada, E-41080 Seville, Spain. Argonne Natl Lab, Energy Technol Div, Argonne, IL 60439 USA. RP Univ Seville, Dept Fis Mat Condensada, POB 1065, E-41080 Seville, Spain. EM aral@us.es RI Koritala, Rachel/F-1774-2011; Melendez, Juan Jose/A-6524-2013; OI Melendez, Juan Jose/0000-0003-1036-6666; R. de Arellano Lopez, Antonio/0000-0002-7443-0244 NR 57 TC 12 Z9 12 U1 0 U2 1 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 OCT 9 PY 2002 VL 50 IS 17 BP 4325 EP 4338 AR PII S1359-6454(02)00264-1 DI 10.1016/S1359-6454(02)00264-1 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 604GV UT WOS:000178609500010 ER PT J AU Smirnov, IV Kotch, FW Pickering, IJ Davis, JT Shafer, RH AF Smirnov, IV Kotch, FW Pickering, IJ Davis, JT Shafer, RH TI Pb EXAFS studies on DNA quadruplexes: Identification of metal ion binding site SO BIOCHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; LEAD; SEQUENCE; RNA; RECOGNITION; RESOLUTION; TETRAPLEX; PARALLEL; APTAMER; NMR AB Nucleic acid quadruplexes are composed of guanine quartets stabilized by specific metal ions. X-ray diffraction can provide high-resolution information on the structure and metal binding properties of quadruplexes, but only if they can be crystallized. NMR can provide detailed information on the solution structure of such quadruplexes but little quantitative data concerning the metal binding site. Here we apply extended X-ray absorption fine structure (EXAFS) measurements to characterize the metal ion binding site, in frozen solution, of the unimolecular quadruplex formed by the thrombin binding aptamer, d(G(2)T(2)G(2)TGTG(2)T(2)G(2)) (TBA), in the presence of Pb2+ ions. The Pb L-III -edge X-ray absorption spectrum of this metal-DNA complex is very similar to that we obtain for a Pb2+-stabilized quartet system of known structure constructed from a modified guanine nucleoside (G1). The Fourier transforms of the Pb2+ complexes with both TBA and G1 show a first-shell interaction at about 2.6 Angstrom, and a weaker, broader shell at 3.5-4.0 Angstrom. Quantitative analysis of the EXAFS data reveals the following: (i) very close agreement between interatomic distances at the metal coordination site for the Pb2+-G1 complex determined by EXAFS and by X-ray crystallography; (ii) similarly close agreement between interatomic distances measured by EXAFS for the Pb2+-G1 and Pb2+-TBA complexes. These results provide strong evidence for binding of the Pb2+ ion in the region between the two quartets in the Pb2+-TBA complex, coordinated to the eight surrounding guanine O-6 atoms. The specific binding of Pb2+ to DNA examined here may be relevant to the genotoxic effects of this environmentally important heavy metal. Furthermore, these results demonstrate the utility of EXAFS as a method for quantitative characterization of specific metal binding sites in nucleic acids in solution. C1 Univ Calif San Francisco, Sch Pharm, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. SLAC, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Shafer, RH (reprint author), Univ Calif San Francisco, Sch Pharm, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. RI Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 FU NIAID NIH HHS [AI 39152] NR 31 TC 71 Z9 78 U1 1 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 8 PY 2002 VL 41 IS 40 BP 12133 EP 12139 DI 10.1021/bi020310p PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 601XF UT WOS:000178473600022 PM 12356314 ER PT J AU Elioff, MS Chandler, DW AF Elioff, MS Chandler, DW TI State-to-state differential cross sections for spin-multiplet-changing collisions of NO(X (2)Pi(1/2)) with argon SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROTATIONALLY INELASTIC-COLLISIONS; MOLECULAR-OXYGEN; AR; SCATTERING; PHOTOELECTRON; EXCITATION; SYSTEM AB Rotational state-resolved differential cross sections (DCS) for spin-multiplet-changing collisions of NO(X (2)Pi(1/2)-->X (2)Pi(3/2)) with Ar are presented and compared to results from previous experimental and theoretical studies performed on the NO/Ar system. A crossed molecular beam apparatus coupled with velocity-mapped ion imaging was used to measure complete (theta=0degrees-180degrees) DCS for scattering of NO(X (2)Pi(1/2),j=0.5) into NO(X (2)Pi(3/2),j(')) rotational states ranging from j(')=1.5 to j(')=12.5. Scattered products were detected by state-selective ionization using (1+1') resonance-enhanced multiphoton ionization via the A (2)Sigma(+) state. State-to-state DCS were extracted in the center-of-mass frame of reference for energy transfer at a center-of-mass collision energy of similar to530 cm(-1). Studies performed using horizontally and vertically polarized excitation laser beams yielded DCS which were remarkably similar, indicating that state-to-state scattering for this system is insensitive to probe beam polarization. Experimentally determined angular scattering distributions show primarily forward scattering for low-energy rotational states (j<7.5), with side- and back-scattering increasing with product angular momentum. The scattering results are compared and contrasted to results from earlier experimental investigations and to theoretical results from quantum close-coupling calculations based on ab initio coupled cluster CCSD(T) potential energy surfaces. (C) 2002 American Institute of Physics. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. RP Elioff, MS (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. NR 25 TC 27 Z9 28 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 2002 VL 117 IS 14 BP 6455 EP 6462 DI 10.1063/1.1505440 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598BW UT WOS:000178256100009 ER PT J AU Pivonka, NL Kaposta, C von Helden, G Meijer, G Woste, L Neumark, DM Asmis, KR AF Pivonka, NL Kaposta, C von Helden, G Meijer, G Woste, L Neumark, DM Asmis, KR TI Gas phase infrared spectroscopy of cluster anions as a function of size: The effect of solvation on hydrogen-bonding in Br-center dot(HBr)(1,2,3) clusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LEWIS-ACID ADDUCTS; CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; THERMODYNAMIC CALCULATIONS; HALIDE POLYMERS; BIFLUORIDE ANION; DIODE-LASER; IONS; SPECTRUM; CATIONS AB The gas phase vibrational spectroscopy of Br-.(HBr)(1,2,3) clusters has been studied between 6 and 16 mum (625 and 1700 cm(-1)) by multiphoton infrared photodissociation spectroscopy using the output of the free electron laser for infrared experiments. Infrared (IR) spectra were recorded by monitoring the mass-selected ion yield. In all three systems neutral HBr loss is found to be the dominant photofragmentation channel. BrHBr- exhibits a weak absorption band at 1558 cm(-1) which is assigned to the overtone of the antisymmetric stretching mode nu(3). A series of strong absorption bands was observed for Br-.(HBr)(2) at energies in the 950-1450 cm(-1) range. The Br-.(HBr)(3) spectra reveal two absorption bands at 884 and 979 cm(-1), which are assigned to two H-atom stretching modes. Evidence for the localization of the H atom and destruction of the symmetric BrHBr- hydrogen bond in the larger clusters is presented. Standard electronic structure calculations fail to reproduce the experimental IR spectra, indicating a breakdown of the harmonic approximation. (C) 2002 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Free Univ Berlin, Inst Phys Expt, D-14195 Berlin, Germany. Inst Plasmaphys Rijnhuizen, FOM, NL-3439 MN Nieuwegein, Netherlands. Univ Nijmegen, Dept Mol & Laser Phys, NL-6525 ED Nijmegen, Netherlands. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Meijer, Gerard/D-2141-2009; Neumark, Daniel/B-9551-2009; Asmis, Knut/N-5408-2014; von Helden, Gert/H-9357-2012 OI Neumark, Daniel/0000-0002-3762-9473; Asmis, Knut/0000-0001-6297-5856; von Helden, Gert/0000-0001-7611-8740 NR 48 TC 29 Z9 29 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 2002 VL 117 IS 14 BP 6493 EP 6499 DI 10.1063/1.1506308 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598BW UT WOS:000178256100014 ER PT J AU Schenter, GK AF Schenter, GK TI The development of effective classical potentials and the quantum statistical mechanical second virial coefficient of water SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO; LIQUID; SIMULATION; SYSTEMS; DIMER; CLUSTERS; LIGHT AB The second virial coefficient of water is calculated at low temperature by considering full quantum statistical mechanical effects. At low enough temperatures experimental results are limited and molecular models can be used for accurate extrapolation. In doing so, one must separate deficiencies of the intermolecular potential from limitations of the simulation methodology such as the neglect of higher-order quantum corrections. Effective classical potentials may be used to understand the limitations of classical simulation. In this work we calculate the exact quantum statistical mechanical second virial coefficient and find that using a semiclassical form for the effective classical potential we are able to nearly reproduce the exact quantum statistical results. This approach provides a significant improvement to conventional first order expansions of the second virial coefficient. (C) 2002 American Institute of Physics. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 50 TC 37 Z9 37 U1 0 U2 2 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 OCT 8 PY 2002 VL 117 IS 14 BP 6573 EP 6581 DI 10.1063/1.1505441 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598BW UT WOS:000178256100024 ER PT J AU Puzder, A Williamson, AJ Grossman, JC Galli, G AF Puzder, A Williamson, AJ Grossman, JC Galli, G TI Surface control of optical properties in silicon nanoclusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUANTUM MONTE-CARLO; ELECTRONIC-STRUCTURE; POROUS SILICON; SI NANOCRYSTALS; WAVE-FUNCTIONS; DOTS; LUMINESCENCE; PHOTOLUMINESCENCE; NANOPARTICLES; CLUSTERS AB Density functional and quantum Monte Carlo calculations are employed to determine the effect of surface passivants on the optical gap of silicon nanoclusters. Our results show that quantum confinement is only one mechanism responsible for visible photoluminescence and that the specific surface chemistry must be taken into account in order to interpret experimental results. Significant changes occur in the optical gap of fully hydrogenated silicon nanoclusters when the surface contains passivants that change the bonding network at the surface. In the case of just one double-bonded oxygen atom, the gap reduction computed as a function of the nanocluster size demonstrates that one contaminant can greatly alter the optical gap. A further significant reduction of the gap occurs with multiple double-bonded oxygen contamination, providing a consistent interpretation of several recent experiments. We predict that other passivants that distort the tetrahedral bonding network at the surface, including other double-bonded groups and in some cases bridged oxygen, will also significantly affect the optical gap. Conversely, single-bonded passivants will have a minimal influence on the optical gap. A discussion of the difference in the strength of the optical transitions for clusters with different passivants is presented. (C) 2002 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Puzder, A (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 41 TC 109 Z9 110 U1 1 U2 17 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 2002 VL 117 IS 14 BP 6721 EP 6729 DI 10.1063/1.1504707 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598BW UT WOS:000178256100042 ER PT J AU Tsoukatos, T Avgeropoulos, A Hadjichristidis, N Hong, KL Mays, JW AF Tsoukatos, T Avgeropoulos, A Hadjichristidis, N Hong, KL Mays, JW TI Model linear block co-, ter-, and quaterpolymers of 1,3-cyclohexadiene with styrene, isoprene, and butadiene SO MACROMOLECULES LA English DT Article ID LIVING ANIONIC-POLYMERIZATION; N-BUTYLLITHIUM/N,N,N',N'-TETRAMETHYLETHYLENEDIAMINE SYSTEM; MAIN-CHAIN; HYDROCARBON POLYMERS; 6-MEMBERED RINGS; POLY(1,3-CYCLOHEXADIENE); STAR; STEREOCHEMISTRY AB The following linear block co-, ter-, and quaterpolymers of 1,3-cyclohexadiene (CHD) with styrene (S), isoprene (1), and butadiene (B) were synthesized by sequential anionic polymerization: PS-b-PCHD, PI-b-PCHD, PB-b-PCHD, PS-b-PB-b-PCHD, PB-b-PS-b-PCHD, PB-b-PI-b-PCHD, and PS-bPB-b-PI-b-PCHD. sec-Butyllithium with either N,N,N',N'-tetramethylethylonediamine (TMEDA) or 1,4-diazobicyclo[2.2.2]octane (DABCO) was used as the initiating system. In all cases CHD was the last monomer added. The polar additive (TMEDA or DABCO) was always introduced to the polymerization solution prior to the addition of CHD and isoprene. The microstructures of the polydicnes obtained in the different environments were determined by NMR spectroscopy. Thorough characterization by size exclusion chromatography coupled with multiangle laser light scattering, laser differential refractometry, osmometry, and NMR spectroscopy revealed that the synthesized polymeric materials exhibit high molecular and compositional homogeneity. C1 Univ Athens, Dept Chem, Athens 15771, Greece. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Hadjichristidis, N (reprint author), Univ Athens, Dept Chem, Athens 15771, Greece. RI Avgeropoulos, Apostolos/I-5772-2012; Hong, Kunlun/E-9787-2015 OI Hong, Kunlun/0000-0002-2852-5111 NR 36 TC 20 Z9 22 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 8 PY 2002 VL 35 IS 21 BP 7928 EP 7935 DI 10.1021/ma020513l PG 8 WC Polymer Science SC Polymer Science GA 601KG UT WOS:000178444400013 ER PT J AU Lopatin, S Pennycook, SJ Narayan, J Duscher, G AF Lopatin, S Pennycook, SJ Narayan, J Duscher, G TI Z-contrast imaging of dislocation cores at the GaAs/Si interface SO APPLIED PHYSICS LETTERS LA English DT Article ID MISFIT DISLOCATIONS; SEMICONDUCTOR HETEROSTRUCTURES; CRYSTALS; EPITAXY; SI AB The interface between silicon and epitaxial GaAs thin film grown by metalorganic chemical vapor deposition was studied using atomic-resolution Z-contrast imaging. Z-contrast imaging provides chemical composition information and allows direct interpretation of micrographs without simulation. Three different types of dislocations were identified. As expected, a dangling bond was found in the atomic structure of the 60degrees dislocation. One of the observed 90degrees dislocations had the reconstructed atomic core structure (with no dangling bonds). The core structure of the other 90degrees dislocation exhibited a dangling bond. (C) 2002 American Institute of Physics. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Lopatin, S (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA. RI Narayan, Jagdish/D-1874-2009; Duscher, Gerd/G-1730-2014 OI Duscher, Gerd/0000-0002-2039-548X NR 20 TC 33 Z9 33 U1 2 U2 15 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 2002 VL 81 IS 15 BP 2728 EP 2730 DI 10.1063/1.1511808 PG 3 WC Physics, Applied SC Physics GA 599DG UT WOS:000178318400018 ER PT J AU Follstaedt, DM Provencio, PP Missert, NA Mitchell, CC Koleske, DD Allerman, AA Ashby, CIH AF Follstaedt, DM Provencio, PP Missert, NA Mitchell, CC Koleske, DD Allerman, AA Ashby, CIH TI Minimizing threading dislocations by redirection during cantilever epitaxial growth of GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID LATERAL OVERGROWTH; DENSITY GAN; FILMS AB A 40-fold reduction in density of vertical threading dislocations (VTDs) at the surface of GaN is obtained with cantilever epitaxy by using narrow (<1 mum) mesas etched into a sapphire substrate and conditions producing angled {11-22} facets to initiate growth by metalorganic chemical vapor deposition. These two techniques redirect VTDs over the mesas to the horizontal and away from device areas above. Further reductions appear possible if the facets uniformly cover all mesas prior to cantilever growth. (C) 2002 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Follstaedt, DM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 32 Z9 33 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 2002 VL 81 IS 15 BP 2758 EP 2760 DI 10.1063/1.1511286 PG 3 WC Physics, Applied SC Physics GA 599DG UT WOS:000178318400028 ER PT J AU Agassi, D Christen, DK Pennycook, SJ AF Agassi, D Christen, DK Pennycook, SJ TI Flux pinning and critical currents at low-angle grain boundaries in high-temperature superconductors SO APPLIED PHYSICS LETTERS LA English DT Article ID REDUCED CRITICAL CURRENTS; CRITICAL-CURRENT DENSITY; NORMAL-STATE PROPERTIES; THIN-FILMS; TWIN BOUNDARY; YBA2CU3O7-DELTA; TRANSPORT; ORIGIN AB Calculations of the pinning potential at low-angle grain boundaries in high-temperature superconductors are presented which fully incorporate the periodic nature of the low-angle boundary. A nonlocal kernel provides a smooth transition from an Abrikosov vortex far from the boundary to a Josephson vortex near the dislocations. We examine the angular dependence of critical current in the two idealized limits of pure strain and pure band bending. Recent data appear limited by band bending with significant potential for improvement through doping. (C) 2002 American Institute of Physics. C1 USN, Ctr Surface Warfare, Carderock Div, Funct Mat Dept, Bethesda, MD 20817 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Agassi, D (reprint author), USN, Ctr Surface Warfare, Carderock Div, Funct Mat Dept, 9500 MacArthur Blvd, Bethesda, MD 20817 USA. NR 28 TC 13 Z9 13 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 2002 VL 81 IS 15 BP 2803 EP 2805 DI 10.1063/1.1502907 PG 3 WC Physics, Applied SC Physics GA 599DG UT WOS:000178318400043 ER PT J AU Guillorn, MA Hale, MD Merkulov, VI Simpson, ML Eres, GY Cui, H Puretzky, AA Geohegan, DB AF Guillorn, MA Hale, MD Merkulov, VI Simpson, ML Eres, GY Cui, H Puretzky, AA Geohegan, DB TI Operation of individual integrally gated carbon nanotube field emitter cells SO APPLIED PHYSICS LETTERS LA English DT Article ID CATHODE AB In this work, we examine the operation of individual field emitter cells contained in a field emitter array composed of integrally gated multiwalled carbon nanotube (MWNT)-based field emission cathodes. These devices were found to behave in a manner consistent with a multiple emission site model of Fowler-Nordheim field emission. These results show considerable variation in the operational characteristics of cells contained within the same array and indicate that data obtained from arrays of cells are not necessarily indicative of individual cell performance. (C) 2002 American Institute of Physics. C1 Oak Ridge Natl Lab, Mol Scale Engn & Nanoscale Technol Res Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Thin Film & Nanostruct Mat Phys Res Grp, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. RP Guillorn, MA (reprint author), Oak Ridge Natl Lab, Mol Scale Engn & Nanoscale Technol Res Grp, Oak Ridge, TN 37831 USA. RI Simpson, Michael/A-8410-2011; Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013; Eres, Gyula/C-4656-2017 OI Simpson, Michael/0000-0002-3933-3457; Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139; Eres, Gyula/0000-0003-2690-5214 NR 7 TC 25 Z9 25 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 2002 VL 81 IS 15 BP 2860 EP 2862 DI 10.1063/1.1512955 PG 3 WC Physics, Applied SC Physics GA 599DG UT WOS:000178318400062 ER PT J AU Xiao, ZL Han, CY Welp, U Wang, HH Vlasko-Vlasov, VK Kwok, WK Miller, DJ Hiller, JM Cook, RE Willing, GA Crabtree, GW AF Xiao, ZL Han, CY Welp, U Wang, HH Vlasko-Vlasov, VK Kwok, WK Miller, DJ Hiller, JM Cook, RE Willing, GA Crabtree, GW TI Nickel antidot arrays on anodic alumina substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID MAGNETIC DOMAIN FORMATION; NANOWIRE ARRAYS; ANISOTROPIC MAGNETORESISTANCE; GIANT MAGNETORESISTANCE; THIN-FILMS; CO; MULTILAYERS; FABRICATION; WIRES; HOLES AB Large-area nickel antidot arrays with a density up to 10(10)/cm(2) have been fabricated by depositing nickel onto anodic aluminum oxide membranes that contain lattices of nanopores. Electron microscopy images show a high degree of order of the antidot arrays. Various sizes and shapes of the antidots were observed with increasing thickness of the deposited nickel. New features appear in the antidot arrays in both magnetization and transport measurements when the external magnetic field is parallel to the current direction, including an enhancement and a nonmonotonous field dependence of the magnetoresistance, larger values of the coercive field and remanence moment, and smaller saturation field. (C) 2002 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Xiao, ZL (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM xiao@anl.gov RI Hiller, Jon/A-2513-2009 OI Hiller, Jon/0000-0001-7207-8008 NR 31 TC 107 Z9 109 U1 1 U2 16 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 7 PY 2002 VL 81 IS 15 BP 2869 EP 2871 DI 10.1063/1.1512993 PG 3 WC Physics, Applied SC Physics GA 599DG UT WOS:000178318400065 ER PT J AU Gschneidner, KA AF Gschneidner, KA TI The fruition of 4f discovery, the interplay of basic and applied research SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Rare Earths 2001 Conference CY SEP 22-26, 2001 CL SAO PAULO, BRAZIL DE magnetic refrigeration; supercooling; superheating; regenerator materials; magnetocaloric effect; erbium; dysprosium; Gd-5(SixGe1-x)(4); Pr-doped Er alloys ID TEMPERATURE MAGNETIC REFRIGERATION; ORDER PHASE-TRANSITION; ELECTRICAL-RESISTANCE; FIELD; GD-5(SI2GE2); GD-5(SIXGE1-X)(4); GD-5(SI1.8GE2.2); ERBIUM AB A broad base of knowledge is necessary for the successful solution to applied problems, but on the other hand, developing such practical solutions can open the door to new and exciting adventures in basic research. Several such synergistic events are briefly described. These include the design and development of magnetic refrigerant materials (1) for the liquefaction of H, gas, and (2) for near-room temperature cooling and refrigeration; and (3) the design and development of cryocooler regenerator materials. The first led to the discovery of both supercooling and superheating in the same substance (Dy and Er); the second to the discovery of the giant magnetocaloric effect, the colossal magnetostriction, and the giant magnetoresistance in the same substance [Gd-5(SixGe1-x)(4)]; and the third the disappearance of three of the four magnetically ordered phases in Er by Pr additions in both high purity Er and commercial grade Er. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Gschneidner, KA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 27 TC 6 Z9 6 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 OCT 7 PY 2002 VL 344 IS 1-2 BP 356 EP 361 AR PII S0925-8388(02)00385-7 DI 10.1016/S0925-8388(02)00385-7 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 608NJ UT WOS:000178852200079 ER PT J AU Pecharsky, VK Pecharsky, AO Gschneidner, KA AF Pecharsky, VK Pecharsky, AO Gschneidner, KA TI Uncovering the structure-property relationships in R-5(SixGe4-x) intermetallic phases SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Rare Earths 2001 Conference CY SEP 22-26, 2001 CL SAO PAULO, BRAZIL DE gadolinium-germanium-silicide; structure-property relationships; first order phase transformations ID ADIABATIC TEMPERATURE-CHANGE; MAGNETIC-FIELD; ELECTRICAL-RESISTANCE; TRANSITION; GD-5(SI2GE2); GD-5(SIXGE1-X)(4); GD-5(SI1.5GE2.5); GD-5(SI1.8GE2.2); GD5SI2GE2; BEHAVIOR AB A family of intermetallic compounds, R-5(SixGe4-x), where R=rare earth metal has opened up a unique opportunity to a solution of a century-old problem of the intrinsic relationships between the composition, atomic structure and properties of metallic materials. To date the largest body of knowledge has been accumulated in the system with R=Gd. The known crystal structures of the Gd-5(SixGe4-x) phases are closely related to one another and consist of 36 atoms per unit cell distributed among six or nine independent crystallographic sites in orthorhombic or monoclinic crystal systems, respectively. We show that in a certain range of compositions (i.e. when 2 vd(5/2), g(7/2) one-particle-one-hole excitation across the N = 50 shell closure. (C) 2002 Elsevier Science B.V All rights reserved. C1 Inst Nucl Res, H-4001 Debrecen, Hungary. Warsaw Univ, Heavy Ion Lab, Warsaw, Poland. Royal Inst Technol, Stockholm, Sweden. Lund Univ, Dept Phys, Lund, Sweden. Svedberg Lab, S-75121 Uppsala, Sweden. Ist Nazl Fis Nucl, Lab Nazl Legnaro, Padua, Italy. Uppsala Univ, Dept Radiat Sci, Uppsala, Sweden. Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Sez Padova, Padua, Italy. Univ Helsinki, Dept Phys, Helsinki, Finland. Univ Valencia, Valencia, Spain. GSI Darmstadt, D-6100 Darmstadt, Germany. Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Jozef Stefan Inst, Ljubljana, Slovenia. Soltan Inst Nucl Studies, Otwock, Poland. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. Argonne Natl Lab, Chicago, IL USA. RP Dombradi, Z (reprint author), Inst Nucl Res, H-4001 Debrecen, Hungary. RI Rudolph, Dirk/D-4259-2009; Dombradi, Zsolt/B-3743-2012; Lenzi, Silvia/I-6750-2012; Cederwall, Bo/M-3337-2014; Gadea, Andres/L-8529-2014; Algora, Alejandro/E-2960-2015; Palacz, Marcin/H-3713-2012; Napoli, Daniel R./D-9863-2012; OI Rudolph, Dirk/0000-0003-1199-3055; Cederwall, Bo/0000-0003-1771-2656; Gadea, Andres/0000-0002-4233-1970; Algora, Alejandro/0000-0002-5199-1794; Napoli, Daniel R./0000-0002-8154-6958; Back, Torbjorn/0000-0003-1996-0805 NR 24 TC 7 Z9 7 U1 0 U2 1 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 OCT 7 PY 2002 VL 708 IS 3-4 BP 181 EP 189 AR PII S0375-9474(02)01014-X DI 10.1016/S0375-9474(02)01014-X PG 9 WC Physics, Nuclear SC Physics GA 590TW UT WOS:000177840100002 ER PT J AU Bennaceur, K Berger, JF Ducomet, B AF Bennaceur, K Berger, JF Ducomet, B TI Coupling to the continuous spectrum and HFB approximation SO NUCLEAR PHYSICS A LA English DT Article DE Hartree-Fock calculation; unstable nuclei; finite-range interaction ID D-1 EFFECTIVE INTERACTION; MEAN-FIELD; DRIP-LINE; NUCLEI; STATES AB We propose a new method to solve the Hartree-Fock-Bogoliubov equations for weakly bound nuclei whose purpose is to improve the treatment of the continuum when a finite range two-body interaction is used. We replace the traditional expansion on a discrete harmonic oscillator basis by a mixed eigenfunction expansion associated with a potential that explicitly includes a continuous spectrum. We overcome the problem of continuous spectrum discretization by using a resonance expansion. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Lyon 1, CNRS, IN2P3, IPN Lyon, F-69622 Villeurbanne, France. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. CEA, Dept Phys Theor & Appl, F-91680 Bruyeres Le Chatel, France. RP Bennaceur, K (reprint author), Univ Lyon 1, CNRS, IN2P3, IPN Lyon, 43 Bd 11 Novembre 1918, F-69622 Villeurbanne, France. RI Bennaceur, Karim/O-1680-2016 OI Bennaceur, Karim/0000-0002-6722-491X NR 27 TC 3 Z9 3 U1 0 U2 1 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 OCT 7 PY 2002 VL 708 IS 3-4 BP 205 EP 225 AR PII S0375-9474(02)01012-6 DI 10.1016/S0375-9474(02)01012-6 PG 21 WC Physics, Nuclear SC Physics GA 590TW UT WOS:000177840100004 ER PT J AU Iancu, E Itakura, K McLerran, L AF Iancu, E Itakura, K McLerran, L TI Geometric scaling above the saturation scale SO NUCLEAR PHYSICS A LA English DT Article ID WILSON RENORMALIZATION-GROUP; GLUON DISTRIBUTION-FUNCTIONS; DEEP-INELASTIC SCATTERING; WEIZSACKER-WILLIAMS FIELD; COLOR GLASS CONDENSATE; SMALL-X BEHAVIOR; HIGH-DENSITY QCD; HIGH-ENERGY DIS; BFKL POMERON; LARGE NUCLEI AB We show that the evolution equations in QCD predict geometric scaling for quark and gluon distribution functions in a large kinematical window, which extends above the saturation scale up to momenta Q(2) of order 100 GeV2. For Q(2) < Q(s)(2), with Qs the saturation momentum, this is the scaling predicted by the Colour Glass Condensate and by phenomenological saturation models. For 1 less than or similar to ln(Q(2)/Qs(2)) much less than ln(Q(s)(2)/A(QCD)(2)), we show that the solution to the BFKL equation shows approximate scaling, with the scale set by Qs. At larger Q2, this solution does not scale any longer. We argue that for the intermediate values of Q2 where we find scaling, the BFKL rather than the double logarithmic approximation to the DGLAP equation properly describes the dynamics. We consider both fixed and running couplings, with the scale for running set by the saturation momentum. The anomalous dimension which characterizes the approach of the gluon distribution function towards saturation is found to be close to, but lower than, one half. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CE Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. Brookhaven Natl Lab, Res Ctr, RIKEN, Upton, NY 11973 USA. Brookhaven Natl Lab, Nucl Theory Grp, Upton, NY 11973 USA. RP Iancu, E (reprint author), CE Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. NR 65 TC 295 Z9 295 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 OCT 7 PY 2002 VL 708 IS 3-4 BP 327 EP 352 AR PII S0375-9474(02)01010-2 DI 10.1016/S0375-9474(02)01010-2 PG 26 WC Physics, Nuclear SC Physics GA 590TW UT WOS:000177840100010 ER PT J AU Baur, U Plehn, T Rainwater, D AF Baur, U Plehn, T Rainwater, D TI Measuring the Higgs boson self-coupling at the Large Hadron Collider SO PHYSICAL REVIEW LETTERS LA English DT Article ID LINEAR COLLIDERS; PAIR PRODUCTION; GLUON FUSION; LHC; SECTOR AB Inclusive standard model Higgs boson pair production and subsequent decay to same-sign dileptons via weak gauge W+/- bosons at the CERN Large Hadron Collider (LHC) has the capability to determine the Higgs boson self-coupling, lambda. The large top quark mass limit is found not to be a good approximation for the signal if one wishes to utilize differential distributions in the analysis. We find that it should be possible at the LHC with design luminosity to establish that the standard model Higgs boson has a nonzero self-coupling and that lambda/lambda(SM) can be restricted to a range of 0-3.7 at 95% confidence level if its mass is between 150 and 200 GeV. C1 SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Fermilab Natl Accelerator Lab, Theory Grp, Batavia, IL 60510 USA. RP SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. NR 40 TC 101 Z9 101 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 7 PY 2002 VL 89 IS 15 AR 151801 DI 10.1103/PhysRevLett.89.151801 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500008 PM 12365980 ER PT J AU Denlinger, JD Clack, JA Allen, JW Gweon, GH Poirier, DM Olson, CG Sarrao, JL Bianchi, AD Fisk, Z AF Denlinger, JD Clack, JA Allen, JW Gweon, GH Poirier, DM Olson, CG Sarrao, JL Bianchi, AD Fisk, Z TI Bulk band gaps in divalent hexaborides SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-SURFACE; ELECTRON-GAS; FERROMAGNETISM; EUB6; CAB6; INSULATORS; CA1-XLAXB6; SCATTERING; TRANSPORT AB Complementary angle-resolved photoemission and bulk-sensitive k-resolved resonant inelastic x-ray scattering of divalent hexaborides reveal a >1 eV X-point gap between the valence and conduction bands, in contradiction to the band overlap assumed in several models of their novel ferromagnetism. This semiconducting gap implies that carriers detected in transport measurements arise from defects, and the measured location of the bulk Fermi level at the bottom of the conduction band implicates boron vacancies as the origin of the excess electrons. The measured band structure and X-point gap in CaB6 additionally provide a stringent test case for many-body quasiparticle band calculations. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Michigan, Randall Lab, Ann Arbor, MI 48109 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. RP Denlinger, JD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RI Bianchi, Andrea/E-9779-2010 OI Bianchi, Andrea/0000-0001-9340-6971 NR 33 TC 71 Z9 71 U1 1 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 OCT 7 PY 2002 VL 89 IS 15 AR 157601 DI 10.1103/PhysRevLett.89.157601 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500050 PM 12366022 ER PT J AU MacLaughlin, DE Sonier, JE Heffner, RH Bernal, OO Young, BL Rose, MS Morris, GD Bauer, ED Do, TD Maple, MB AF MacLaughlin, DE Sonier, JE Heffner, RH Bernal, OO Young, BL Rose, MS Morris, GD Bauer, ED Do, TD Maple, MB TI Muon spin relaxation and isotropic pairing in superconducting PrOs4Sb12 SO PHYSICAL REVIEW LETTERS LA English DT Article ID PENETRATION-DEPTH; ROTATION; MAGNETISM; FIELD; PHASE; SR AB Transverse-field muon-spin rotation measurements in the vortex-lattice of the heavy-fermion (HF) superconductor PrOs4Sb12 yield a temperature dependence of the magnetic penetration depth lambda indicative of an isotropic or nearly isotropic energy gap. This is not seen to date in any other HF superconductor and is a signature of isotropic pairing symmetry, possibly related to a novel nonmagnetic "quadrupolar Kondo" HF mechanism in PrOs4Sb12. The T=0 relaxation rate sigma(s)(0)=0.91(1) mus(-1) yields an estimated magnetic penetration depth lambda(0)=3440(20) Angstrom, which is considerably shorter than in other HF superconductors. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Canadian Inst Adv Res, Toronto, ON M5G 1Z8, Canada. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Calif State Univ Los Angeles, Dept Phys & Astron, Los Angeles, CA 90032 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP MacLaughlin, DE (reprint author), Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. RI Bauer, Eric/D-7212-2011 NR 24 TC 88 Z9 88 U1 1 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 OCT 7 PY 2002 VL 89 IS 15 AR 157001 DI 10.1103/PhysRevLett.89.157001 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500041 PM 12366013 ER PT J AU Miao, J Ohsuna, T Terasaki, O Hodgson, KO O'Keefe, MA AF Miao, J Ohsuna, T Terasaki, O Hodgson, KO O'Keefe, MA TI Atomic resolution three-dimensional electron diffraction microscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY CRYSTALLOGRAPHY; PHASE RETRIEVAL; RECONSTRUCTION; HOLOGRAPHY AB We report the development of a novel form of diffraction-based 3D microscopy to overcome resolution barriers inherent in high-resolution electron microscopy and tomography. By combining coherent electron diffraction with the oversampling phasing method, we show that the 3D structure of a nanocrystal can be determined ab initio at a resolution of 1 angle from 29 simulated noisy diffraction patterns. This new form of microscopy can be used to image the 3D structures of nanocrystals and noncrystalline samples, with resolution limited only by the quality of sample diffraction. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 9808577, Japan. Tohoku Univ, CIR, Sendai, Miyagi 9808577, Japan. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Lawrence Berkeley Natl Lab, Div Sci Mat, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Miao, J (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. NR 20 TC 42 Z9 43 U1 2 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 OCT 7 PY 2002 VL 89 IS 15 AR 155502 DI 10.1103/PhysRevLett.89.155502 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500027 PM 12365999 ER PT J AU Roberts, CD Schmidt, SM Vinnik, DV AF Roberts, CD Schmidt, SM Vinnik, DV TI Quantum effects with an x-ray free-electron laser SO PHYSICAL REVIEW LETTERS LA English DT Article ID PAIR PRODUCTION; FIELD; CREATION; EQUATION; VACUUM AB A quantum kinetic equation coupled with Maxwell's equation is used to estimate the laser power required at an x-ray free-electron laser (XFEL) facility to expose intrinsically quantum effects in the process of QED vacuum decay via spontaneous pair production. A 9 -TW-peak XFEL laser with photon energy of 8.3 keV could be sufficient to initiate particle accumulation and the consequent formation of a plasma of spontaneously produced pairs. The evolution of the particle number in the plasma will exhibit non-Markovian aspects of the strong-field pair production process, and the plasma's internal currents will generate an electric field whose interference with that of the laser leads to plasma oscillations. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. Helmholtz Gemeinschaft, D-53175 Bonn, Germany. RP Roberts, CD (reprint author), Argonne Natl Lab, Div Phys, Bldg 203, Argonne, IL 60439 USA. NR 22 TC 73 Z9 74 U1 1 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 OCT 7 PY 2002 VL 89 IS 15 AR 153901 DI 10.1103/PhysRevLett.89.153901 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500015 PM 12365987 ER PT J AU Sidorov, VA Nicklas, M Pagliuso, PG Sarrao, JL Bang, Y Balatsky, AV Thompson, JD AF Sidorov, VA Nicklas, M Pagliuso, PG Sarrao, JL Bang, Y Balatsky, AV Thompson, JD TI Superconductivity and quantum criticality in CeCoIn5 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTIVITY; HEAVY-FERMION COMPOUNDS; CRITICAL-POINT; UNCONVENTIONAL SUPERCONDUCTIVITY; PRESSURE; RESISTIVITY; FLUCTUATIONS; PSEUDOGAP; CERHIN5; CEIRIN5 AB Electrical resistivity measurements on a single crystal of the heavy-fermion superconductor CeCoIn5 at pressures to 4.2 GPa reveal a strong crossover in transport properties near P(*)approximate to1.6 GPa, where T-c is a maximum. The temperature-pressure phase diagram constructed from these data provides a natural connection to cuprate physics, including the possible existence of a pseudogap. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Russian Acad Sci, Inst High Pressure Phys, Troitsk 142092, Russia. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Pagliuso, Pascoal/C-9169-2012; Nicklas, Michael/B-6344-2008 OI Nicklas, Michael/0000-0001-6272-2162 NR 33 TC 203 Z9 207 U1 5 U2 43 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 OCT 7 PY 2002 VL 89 IS 15 AR 157004 DI 10.1103/PhysRevLett.89.157004 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500044 PM 12366016 ER PT J AU Ye, F Zhou, L Larochelle, S Lu, L Belanger, DP Greven, M Lederman, D AF Ye, F Zhou, L Larochelle, S Lu, L Belanger, DP Greven, M Lederman, D TI Order parameter criticality of the d=3 random-field ising antiferromagnet Fe0.85Zn0.15F2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRITICAL-BEHAVIOR; MODEL; FE0.93ZN0.07F2; SCATTERING; EXPONENT; SYSTEMS AB The critical exponent beta=0.16+/-0.02 for the random-field Ising model order parameter is determined using extinction-free magnetic x-ray scattering for Fe0.85Zn0.15F2 in magnetic fields of 10 and 11 T. The observed value is consistent with other experimental random-field critical exponents, but disagrees sharply with Monte Carlo and exact ground state calculations on finite-sized systems. C1 Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Stanford Univ, TH Geballe Lab Adv Mat, Stanford, CA 94305 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Ye, F (reprint author), Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. RI Ye, Feng/B-3210-2010 OI Ye, Feng/0000-0001-7477-4648 NR 25 TC 31 Z9 31 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 OCT 7 PY 2002 VL 89 IS 15 AR 157202 DI 10.1103/PhysRevLEtt.89.157202 PG 4 WC Physics, Multidisciplinary SC Physics GA 596ZC UT WOS:000178195500046 PM 12366018 ER PT J AU Huber, JS Moses, WW Jones, WF Watson, CC AF Huber, JS Moses, WW Jones, WF Watson, CC TI Effect of Lu-176 background on singles transmission for LSO-based PET cameras SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID NOISE EQUIVALENT COUNTS; HIGH-RESOLUTION; LUTETIUM OXYORTHOSILICATE; ATTENUATION CORRECTION; SMALL ANIMALS; SCANNER; DESIGN; SENSITIVITY; SCINTILLATOR; MICROPET AB We explore how the radioactive background from naturally occurring Lu-176 affects single photon transmission imaging for lutetium orthosilicate (LSO) scintillator-based PET cameras by estimating the transmission noise equivalent count rate (NECR) including this background. Assuming a typical PET camera geometry (80 cm detector ring diameter), we use a combination of measurement and analytic computation to estimate the counting rates due to transmission, scatter and background events as a function of singles transmission source strength. We then compute a NECR for singles transmission. We find that the presence of radiation from the naturally occurring Lu-176 reduces the NECR by 60% or higher for source strengths less than 10 mCi, and that a 25% reduction of the NECR can occur even with a source strength of 40 mCi. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. CPS Innovat, Knoxville, TN 37932 USA. RP Huber, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. FU NCI NIH HHS [R01-CA67911]; NHLBI NIH HHS [P01-HL25840] NR 23 TC 26 Z9 26 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD OCT 7 PY 2002 VL 47 IS 19 BP 3535 EP 3541 AR PII S0031-9155(02)37737-6 DI 10.1088/0031-9155/47/19/307 PG 7 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 608LF UT WOS:000178847300007 PM 12408480 ER PT J AU Davies, RW Vetrano, JS Smith, MT Pitman, SG AF Davies, RW Vetrano, JS Smith, MT Pitman, SG TI Mechanical properties of aluminum tailor welded blanks at superplastic temperatures SO JOURNAL OF MATERIALS PROCESSING TECHNOLOGY LA English DT Article DE superplastic; automotive; aluminum; weld ID ALLOY AB This paper describes an investigation of the mechanical properties of weld material in aluminum tailor welded blanks (TWBs) at superplastic temperatures and discusses the potential application of TWBs in superplastic forming operations. Aluminum TWBs consist of multiple sheet materials of different thicknesses or alloys that are butt-welded together into a single, variable thickness blank. To evaluate the performance of the weld material in TWBs, a series of tensile tests were conducted at superplastic temperatures with specimens that contained weld material in the gage area. The sheet material used in the study was SKY 5083 aluminum alloy, which was joined to produce the TWBs by gas tungsten arc welding using an AA5356 filler wire. The experimental results show that, in the temperature range of 500-550 degreesC and at strain rates ranging from 10(-4) to 10(-2) s(-1), the weld material has a higher flow stress and lower ductility than the monolithic sheet material. The weld material exhibited elongations of 40-60% under these conditions, whereas the monolithic sheet achieved 220-360% elongation. At the same temperatures and strain rates, the weld material exhibited flow stresses 1.3-4 times greater than the flow stress in the monolithic sheet. However, the weld material did show a substantial increase in the strain rate sensitivity when compared to the same material formed at room temperature. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Battelle Pacific NW Natl Lab, Richland, WA 99352 USA. RP Davies, RW (reprint author), Battelle Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 13 TC 29 Z9 29 U1 2 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-0136 J9 J MATER PROCESS TECH JI J. Mater. Process. Technol. PD OCT 6 PY 2002 VL 128 IS 1-3 BP 38 EP 47 AR PII S0924-0136(02)00162-0 DI 10.1016/S0924-0136(02)00162-0 PG 10 WC Engineering, Industrial; Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 606AX UT WOS:000178711000006 ER PT J AU Yeates, TO AF Yeates, TO TI Structures of SET domain proteins: Protein lysine methyltransferases make their mark SO CELL LA English DT Review ID CHROMATIN AB Proteins bearing the widely distributed SET domain have been shown to methylate lysine residues in histones and other proteins. In this issue, three-dimensional structures are reported for three very different SET domain-containing proteins. The structures reveal novel folds for several new domains, including SET, and provide early insights into mechanisms of catalysis and molecular recognition in this family of enzymes. C1 Univ Calif Los Angeles, DOE Ctr genom & Proteom, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Mol Biol, Los Angeles, CA 90095 USA. RP Yeates, TO (reprint author), Univ Calif Los Angeles, Inst Mol Biol, 611 Charles Young Dr E,Box 951570, Los Angeles, CA 90095 USA. OI Yeates, Todd/0000-0001-5709-9839 NR 21 TC 36 Z9 40 U1 1 U2 3 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD OCT 4 PY 2002 VL 111 IS 1 BP 5 EP 7 DI 10.1016/S0092-8674(02)01010-3 PG 3 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 601RQ UT WOS:000178461900002 PM 12372294 ER PT J AU Zhang, X Tamaru, H Khan, SI Horton, JR Keefe, LJ Selker, EU Cheng, XD AF Zhang, X Tamaru, H Khan, SI Horton, JR Keefe, LJ Selker, EU Cheng, XD TI Structure of the neurospora SET domain protein DIM-5, a histone H3 lysine methyltransferase SO CELL LA English DT Article ID HP1 CHROMO DOMAIN; CRYSTAL-STRUCTURE; METHYLATION; DNA; INSIGHTS; SITE AB AdoMet-dependent methylation of histones is part of the "histone code" that can profoundly influence gene expression. We describe the crystal structure of Neurospora DIM-5, a histone H3 lysine 9 methyltranferase (HKMT), determined at 1.98 Angstrom resolution, as well as results of biochemical characterization and site-directed mutagenesis of key residues. This SET domain protein bears no structural similarity to previously characterized AdoMet-dependent methyltransferases but includes notable features such as a triangular Zn(3)Cys(9) zinc cluster in the pre-SET domain and a AdoMet binding site in the SET domain essential for methyl transfer. The structure suggests a mechanism for the methylation reaction and provides the structural basis for functional characterization of the HKMT family and the SET domain. C1 Emory Univ, Sch Med, Dept Biochem, Atlanta, GA 30322 USA. Univ Oregon, Inst Mol Biol, Eugene, OR 97403 USA. Argonne Natl Lab, Adv Photon Source IMCA CAT, Argonne, IL 60439 USA. RP Cheng, XD (reprint author), Emory Univ, Sch Med, Dept Biochem, 1510 Clifton Rd, Atlanta, GA 30322 USA. RI Horton, John/F-2375-2010; ID, IMCACAT/D-5867-2014 FU NIGMS NIH HHS [R01 GM035690, GM35690, GM49245, GM61355, R01 GM049245, R01 GM061355, R01 GM061355-03, R37 GM035690] NR 54 TC 152 Z9 157 U1 2 U2 20 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD OCT 4 PY 2002 VL 111 IS 1 BP 117 EP 127 DI 10.1016/S0092-8674(02)00999-6 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 601RQ UT WOS:000178461900013 PM 12372305 ER PT J AU Xu, J Moxom, J Yang, S Suzuki, R Ohdaira, T AF Xu, J Moxom, J Yang, S Suzuki, R Ohdaira, T TI Dependence of porosity in methyl-silsesquioxane thin films on molecular weight of sacrificial triblock copolymer SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ANNIHILATION LIFETIME SPECTROSCOPY; POSITRON AB Positron annihilation spectroscopy is used to characterize pore sizes and their interconnectivity for porous low dielectric constant methyl-silsequioxane thin films, which are templated by triblock copolymers. More than 1 mum of ortho-positroniurn (o-Ps) diffusion length has been observed for certain films, indicating high interconnectivity of pores. S parameters from Doppler broadening of annihilation photons (DBAP) show homogeneous depth profiles of these films. o-Ps 3gamma emission and lifetimes show that the pore interconnectivity depends on the characteristics of the triblock copolymers. Pores generated from polymers with higher molecular mass are smaller and more closed, while pores generated by polymers with lower molecular mass and smaller ethylene oxide fraction are more interconnected. (C) 2002 Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058568, Japan. RP Xu, J (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Yang, Shu/D-9758-2011 NR 16 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 4 PY 2002 VL 364 IS 3-4 BP 309 EP 313 AR PII S0009-2614(02)01369-6 DI 10.1016/S0009-2614(02)01369-6 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 603JB UT WOS:000178554900017 ER PT J AU Cavalleri, M Ogasawara, H Pettersson, LGM Nilsson, A AF Cavalleri, M Ogasawara, H Pettersson, LGM Nilsson, A TI The interpretation of X-ray absorption spectra of water and ice SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LIQUID WATER; SPECTROSCOPY; EDGE AB The changes in the X-ray Absorption Spectrum (XAS) of water upon formation of hydrogen bonds (H-bonds) are analyzed with the aid of Density Functional Theory (DFT) calculations. The tetrahedral symmetry of the ice structure removes the p-character from the 4a(1) level, leading to very weak intensity in the pre-edge region. Breaking an accepting H-bond has very little effect on the absorption spectrum. A broken donating H-bond, however, is identified through a strong pre-edge feature in XAS. The asymmetry on the hydrogen side causes a(1) and b(2) orbital mixing and the orbitals localize along the internal O-H bonds. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Stockholm Univ, FYSIKUM, SCFAB, S-10691 Stockholm, Sweden. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Nilsson, A (reprint author), Stockholm Univ, FYSIKUM, SCFAB, S-10691 Stockholm, Sweden. RI Cavalleri, Matteo/A-7689-2008; Nilsson, Anders/E-1943-2011; Pettersson, Lars/F-8428-2011; Pettersson, Lars/J-4925-2013; Ogasawara, Hirohito/D-2105-2009 OI Nilsson, Anders/0000-0003-1968-8696; Pettersson, Lars/0000-0003-1133-9934; Ogasawara, Hirohito/0000-0001-5338-1079 NR 18 TC 135 Z9 135 U1 1 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 4 PY 2002 VL 364 IS 3-4 BP 363 EP 370 AR PII S0009-2614(02)00890-4 DI 10.1016/S0009-2614(02)00890-4 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 603JB UT WOS:000178554900026 ER PT J AU Tomkins, BA Ilgner, RH AF Tomkins, BA Ilgner, RH TI Determination of atrazine and four organophosphorus pesticides in ground water using solid phase microextraction (SPME) followed by gas chromatography with selected-ion monitoring SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE water analysis; solid-phase microextraction; organophosphorus compounds; atrazine; pesticides; vapona; supona; malathion; parathion ID INSECTICIDES; SAMPLES AB A rapid, sensitive, and convenient method is presented for the determination of atrazine and four organophosphorus pesticides (OPP) in small (10 ml) samples of ground water. Samples are initially fortified with ethion (internal standard), then extracted without organic solvent using a 65-mum thickness polydimethylsiloxane/divinylbenzene (PDMS-DVB) solid-phase microextraction (SPME) fiber. The analytes collected are thermally desorbed in a heated gas chromatographic inlet, separated using a fused-silica capillary column, and detected using a mass selective detector in its selected-ion monitoring (SIM) mode. Two independent statistical procedures were used to evaluate the detection limits, which typically range between 2 and 8 mug l(-1) for these analytes. Method performance was also evaluated using "performance evaluation" samples, in which clean authentic ground waters were fortified to known concentrations with at least two of the analytes of interest. Sample-to-sample analysis time is approximately 30 min, making the new method ideal for "quick turn" determinations. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem Sci, Environm Chem & Mass Spectrometry Grp, Oak Ridge, TN 37831 USA. RP Tomkins, BA (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Environm Chem & Mass Spectrometry Grp, POB 2008, Oak Ridge, TN 37831 USA. OI Tomkins, Bruce/0000-0001-8520-1415 NR 26 TC 60 Z9 66 U1 4 U2 23 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 OCT 4 PY 2002 VL 972 IS 2 BP 183 EP 194 AR PII S0021-9673(02)01121-4 DI 10.1016/S0021-9673(02)01121-4 PG 12 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 600AD UT WOS:000178367700004 PM 12416876 ER PT J AU Ramelot, TA Cort, JR Yee, AA Liu, FR Goshe, MB Edwards, AM Smith, RD Arrowsmith, CH Dever, TE Kennedy, MA AF Ramelot, TA Cort, JR Yee, AA Liu, FR Goshe, MB Edwards, AM Smith, RD Arrowsmith, CH Dever, TE Kennedy, MA TI Myxoma virus immunomodulatory protein M156R is a structural mimic of eukaryotic translation initiation factor eIF2 alpha SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE eIF2 alpha; K3L; myxoma virus M156R; nuclear magnetic resonance; PKR ID SIDE-CHAIN RESONANCES; KINASE PKR; ALPHA-SUBUNIT; GENE-PRODUCT; RIBOSOMAL PROTEIN-S1; BACKBONE AMIDE; DNA-SEQUENCE; K3L PROTEIN; FACTOR-II; RNA AB Phosphorylation of the translation initiation factor eIF2 on Ser51 of its alpha subunit is a key event for regulation of protein synthesis in all eukaryotes. M156R, the product of the myxoma virus M156R open reading frame, has sequence similarity to eIF2alpha as well as to a family of viral proteins that bind to the interferon-induced protein kinase PKR and inhibit phosphorylation of eIF2alpha. In this study, we demonstrate that, like eIF2alpha. M156R is an efficient substrate for phosphorylation by PKR and can compete with eIF2alpha. To gain insights into the substrate specificity of the eIF2alpha kinases, we have determined the nuclear magnetic resonance (NMR) structure of M156R, the first structure of a myxoma virus protein. The fold consists of a five-stranded antiparallel beta-barrel with two of the strands connected by a loop and an a-helix. The similarity between M156R and the beta-barrel structure in the N terminus of eIF2alpha suggests that the viral homologs mimic eIF2alpha structure in order to compete for binding to PKR. A homology-modeled structure of the well-studied vaccinia virus K3L was generated on the basis of alignment with M156R. Comparison of the structures of the K3L model, M156R, and human eIF2a indicated that residues important for binding to PKR are located at conserved positions on the surface of the beta-barrel and in the mobile loop, identifying the putative PKR recognition motif. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Ontario Canc Inst, Div Mol & Struct Biol, Toronto, ON M4X 1K9, Canada. Univ Toronto, Dept Med Biophys, Toronto, ON M5G 1L7, Canada. NIH, Lab Gene Regulat & Dev, Bethesda, MD 20892 USA. RP Kennedy, MA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, K8-98, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012; OI Smith, Richard/0000-0002-2381-2349; Dever, Thomas/0000-0001-7120-9678 FU NIGMS NIH HHS [P50-GM62413] NR 60 TC 26 Z9 26 U1 0 U2 0 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 4 PY 2002 VL 322 IS 5 BP 943 EP 954 DI 10.1016/S0022-2836(02)00858-6 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 605EQ UT WOS:000178664400004 PM 12367520 ER PT J AU Rodi, DJ Soares, AS Makowski, L AF Rodi, DJ Soares, AS Makowski, L TI Quantitative assessment of peptide sequence diversity in M13 combinatorial peptide phage display libraries SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE sequence diversity; filamentous phage; phage display; viral assembly; combinatorial peptide ID AMINO-ACID-RESIDUES; MAJOR COAT PROTEIN; ESCHERICHIA-COLI; SIGNAL PEPTIDE; FILAMENTOUS PHAGE; CYTOPLASMIC MEMBRANE; LEADER PEPTIDASE; CLEAVAGE SITES; MATURE REGION; EPITOPE AB Novel statistical methods have been developed and used to quantitate and annotate the sequence diversity within combinatorial peptide libraries on the basis of small numbers (1-200) of sequences selected at random from commercially available M13 p3-based phage display libraries. These libraries behave statistically as though they correspond to populations containing roughly 4.0 +/- 1.6% of the random dodecapeptides and 7.9 +/- 2.6% of the random constrained heptapeptides that are theoretically possible within the phage populations. Analysis of amino acid residue occurrence patterns shows no demonstrable influence on sequence censorship by Escherichia coli tRNA isoacceptor profiles or either overall codon or Class II codon usage patterns, suggesting no metabolic constraints on recombinant p3 synthesis. There is an overall depression in the occurrence of cysteine, arginine and glycine residues and an overabundance of proline, threonine and histidine residues. The majority of position-dependent amino acid sequence bias is clustered at three positions within the inserted peptides of the dodecapeptide library, +1, + 3 and + 12 downstream from the signal peptidase cleavage site. Conformational tendency measures of the peptides indicate a significant preference for inserts favoring a beta-turn conformation. The observed protein sequence limitations can primarily be attributed to genetic codon degeneracy and signal peptidase cleavage preferences. These data suggest that for applications in which maximal sequence diversity is essential, such as epitope mapping or novel receptor identification, combinatorial peptide libraries should be constructed using codon-corrected trinucleotide cassettes within vector-host systems designed to minimize morphogenesis-related censorship. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Combinatorial Biol Unit, Biosci Div, Argonne, IL 60439 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Makowski, L (reprint author), Argonne Natl Lab, Combinatorial Biol Unit, Biosci Div, Bldg 202,9700 S Cass Ave, Argonne, IL 60439 USA. RI Soares, Alexei/F-4800-2014 OI Soares, Alexei/0000-0002-6565-8503 NR 52 TC 78 Z9 81 U1 1 U2 21 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 4 PY 2002 VL 322 IS 5 BP 1039 EP 1052 DI 10.1016/S0022-2836(02)00844-6 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 605EQ UT WOS:000178664400011 PM 12367527 ER PT J AU Lashuel, HA Petre, BM Wall, J Simon, M Nowak, RJ Walz, T Lansbury, PT AF Lashuel, HA Petre, BM Wall, J Simon, M Nowak, RJ Walz, T Lansbury, PT TI alpha-synuclein, especially the Parkinson's disease-associated mutants, forms pore-like annular and tubular protofibrils SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE alpha-synuclein; Parkinson's disease; protofibrils; transmission electron microscopy; scanning transmission electron microscopy ID APOPTOTIC CELL-DEATH; NEURODEGENERATIVE DISORDERS; FIBRIL FORMATION; LEWY-BODY; IN-VITRO; PROTEIN; FIBRILLIZATION; PATHOGENESIS; MECHANISM; FRAGMENT AB Two mutations in the alpha-synuclein gene (A30P and A53T) have been linked to autosomal dominant early-onset Parkinson's disease (PD). Both mutations promote the formation of transient protofibrils (prefibrillar oligomers), suggesting that protofibrils are linked to cytotoxicity. In this work, the effect of these mutations on the structure of alpha-synuclein oligomers was investigated using electron microscopy and digital image processing. The PD-linked mutations (A30P and A53T) were observed to affect both the morphology and the size distribution of alpha-synuclein protofibrils (measured by analytical ultracentrifugation and scanning transmission electron microscopy). The A30P variant was observed to promote the formation of annular, pore-like protofibrils, whereas A53T promotes formation of annular and tubular protofibrillar structures. Wild-type alpha-synuclein also formed annular protofibrils, but only after extended incubation. The formation of pore-like oligomeric structures may explain the membrane permeabilization activity of alpha-Synuclein protofibrils. These structures may contribute to the pathogenesis of PD. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Harvard Univ, Sch Med, Brigham & Womens Hosp, Ctr Neurol Dis, Cambridge, MA 02139 USA. Harvard Univ, Sch Med, Dept Neurol, Cambridge, MA 02139 USA. Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Lansbury, PT (reprint author), Harvard Univ, Sch Med, Brigham & Womens Hosp, Ctr Neurol Dis, Partners Res Bldg,65 Landsdowne St,Room 451, Cambridge, MA 02139 USA. FU NCRR NIH HHS [P41-RR01777]; NIGMS NIH HHS [GM62580]; NINDS NIH HHS [NS38375] NR 47 TC 472 Z9 488 U1 9 U2 45 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD OCT 4 PY 2002 VL 322 IS 5 BP 1089 EP 1102 DI 10.1016/S0022-2836(02)00735-0 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 605EQ UT WOS:000178664400014 PM 12367530 ER PT J AU Merkle, PB AF Merkle, PB TI Smallpox and public health: a reality check SO SCIENCE LA English DT Letter C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Merkle, PB (reprint author), Sandia Natl Labs, POB 5800,MS0127, Albuquerque, NM 87185 USA. NR 5 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 OCT 4 PY 2002 VL 298 IS 5591 BP 57 EP 57 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 600BJ UT WOS:000178370500018 PM 12365436 ER PT J AU Manaa, MR Fried, LE Melius, CF Elstner, M Frauenheim, T AF Manaa, MR Fried, LE Melius, CF Elstner, M Frauenheim, T TI Decomposition of HMX at extreme conditions: A molecular dynamics simulation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CONDENSED-PHASE DECOMPOSITION; DENSITY-FUNCTIONAL-THEORY; TIGHT-BINDING METHOD; THERMAL-DECOMPOSITION; ENERGETIC MATERIALS; PYROLYSIS PRODUCTS; SHOCK-WAVES; AB-INITIO; OCTAHYDRO-1,3,5,7-TETRANITRO-1,3,5,7-TETRAZOCINE; CHEMISTRY AB We present the results of a quantum molecular dynamics simulation of the chemistry of HMX, a high performance explosive, at a density of 1.9 g/cm(3) and temperature of 3500 K, conditions roughly similar to the Chapman-Jouget detonation state. The molecular forces are determined using the self-consistent-charge density-functional-based tight-binding method. Following the dynamics for a time scale of up to 55 ps allows the construction of effective rate laws for typical products such as H2O, N-2, CO2, and CO. We estimate reaction rates for these products of 0.48, 0.08, 0.05, and 0.11 ps(-1), respectively. We also find reasonable agreement for the concentrations of dominant species with those obtained from thermodynamic calculations, despite the vastly different theoretical underpinning of these methodologies. C1 Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94551 USA. Univ Gesamthsch Paderborn, Fachbereich Phys, D-33098 Paderborn, Germany. RP Manaa, MR (reprint author), Lawrence Livermore Natl Lab, Energet Mat Ctr, POB 808,L-282, Livermore, CA 94551 USA. RI Elstner, Marcus/H-3463-2013; Fried, Laurence/L-8714-2014; Frauenheim, Thomas/C-5653-2015 OI Fried, Laurence/0000-0002-9437-7700; Frauenheim, Thomas/0000-0002-3073-0616 NR 38 TC 86 Z9 91 U1 6 U2 24 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 OCT 3 PY 2002 VL 106 IS 39 BP 9024 EP 9029 DI 10.1021/jp025668+ PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598JU UT WOS:000178273400006 ER PT J AU Shkrob, IA Sauer, MC AF Shkrob, IA Sauer, MC TI Electron localization in liquid acetonitrile SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID QUANTUM MOLECULAR-DYNAMICS; SUPERCRITICAL CARBON-DIOXIDE; CYCLOALKANE SOLVENT HOLES; AQUEOUS CHLORIDE-ION; NON-POLAR LIQUIDS; EXCESS ELECTRON; COMPUTER-SIMULATION; SOLVATED ELECTRONS; NONPOLAR-SOLVENTS; PHOTO-IONIZATION AB Time-resolved one- and two-pulse laser dc photoconductivity has been used to observe two kinds of reducing species, anion-1 and anion-2, in liquid acetonitrile. At 25 degreesC, the standard enthalpy of conversion from anion-1 to anion-2 is -44.3 +/- 3.6 kJ/mol and the conversion time is similar to3 ns, The high-temperature form, anion-1, absorbs in the IR and migrates >3.3 times faster than any other ion in acetonitrile, This rapid migration has a low activation energy of 3.2 kJ/mol (vs similar to7.6 kJ/mol for other ions). Anion-1 rapidly transfers the electron to acceptors with high electron affinity, with rate constant up to 10(11) M-1 s(-1). The low-temperature form, anion-2, absorbs in the visible and exhibits normal mobility and electron-transfer rate, ca. 1.5 x 10(10) M-1 s(-1). It reacts. by proton transfer, with two hydrogen-bonded molecules of water and/or aliphatic alcohols. Laser photoexcitation of these two solvent anions in their respective absorption bands leads to the formation of CH3 and CN-. We present arguments indicating that anion-2 is a dimer radical anion of acetonitrile, whereas anion-1 is a multimer radical anion that may be regarded as a "solvated electron". C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 127 TC 47 Z9 47 U1 3 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 OCT 3 PY 2002 VL 106 IS 39 BP 9120 EP 9131 DI 10.1021/jp0207580 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598JU UT WOS:000178273400019 ER PT J AU Shkrob, IA Takeda, K Williams, F AF Shkrob, IA Takeda, K Williams, F TI Electron localization in solid acetonitrile SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID EXCITED RYDBERG ATOMS; CLUSTER ANIONS; WATER CLUSTERS; EXCESS ELECTRONS; NEGATIVE-IONS; STATES; SPECTRA; ENERGY; CH3CN; ABSTRACTION AB Electron localization in the bulk condensed phases of acetonitrile differs drastically from the corresponding processes that take place in water and aliphatic alcohols. In particular, electron capture following the ionization of liquid and solid acetonitrile yields well-defined radical anions in place of the largely structureless solvated and trapped electrons characteristic of irradiated solutions and rigid glasses. This is remarkable given the many similarities that exist not only between the intrinsic properties of these individual solvent molecules, such as polarity, but also in their cooperative capacity to function as solvents. Here, with the aid of detailed experimental and computational studies, we examine on a fundamental level what gives rise to such a sharp contrast in the behavior of these alkyl cyanides as compared to water and alcohols, EPR and optical spectra, and ab initio calculations on the radical anions are used together with diffraction data for the crystal Structures to demonstrate that electron attachment to nitrile molecules in the crystalline state results in a significant bending of the linear CCN moiety. Moreover, in the formation of the dimer anions, which only takes place in certain crystalline phases, it is determined that the intermolecular bonding occurs between the cyanide carbons in an antiparallel arrangement, A staggered structure Cor the dimer anion in alpha-acetonitrile is then suggested, in which there is a nearly coplanar arrangement with the two bent CCN fragments. The resulting structure accounts for the observed EPR parameters, the position of the UV-vis absorption band, and the trends observed in the vibronic progressions for the four H/D isotopomers. The dimer radical anion in a-acetonitrile retains the same orientation and symmetry as that of the preexisting neutral {CH3CN}(2) pairs in this crystal despite the resulting changes in molecular geometry and in the translational coordinates for the cyanide carbons as the two acetonitrile molecules come together, We suggest that dimer anions of nitriles can form only in the phases where such "anti parallel" pairs occur, including liquid systems, otherwise, the electron remains attached to a single molecule, as in beta-acetonitrile. Because electron capture by water or alcohol molecules in the condensed phase appears to require larger molecular clusters, the contrast between the behavior of these solvents and acetonitrile is attributable to the relative case with which acetonitrile molecules in the crystal or solvent can undergo valence-electron attachment via their accessible low-lying pi* orbitals. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Williams, Ffrancon/E-4893-2011 NR 74 TC 23 Z9 23 U1 0 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 OCT 3 PY 2002 VL 106 IS 39 BP 9132 EP 9144 DI 10.1021/jp020759s PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 598JU UT WOS:000178273400020 ER PT J AU Hagan, MF Majumdar, A Chakraborty, AK AF Hagan, MF Majumdar, A Chakraborty, AK TI Nanomechanical forces generated by surface grafted DNA SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SINGLE-STRANDED-DNA; LIQUID-CRYSTALS; NUCLEIC-ACIDS; HYDRATION FORCES; MOLECULES; MODEL; LAYER; POLYELECTROLYTES; HYBRIDIZATION; SPECTROSCOPY AB Recent experiments show that the adsorption of biomolecules on one surface of a microcantilever generates surface stresses that cause the cantilever to deflect. If a second species binds to the adsorbed molecules, the stresses change, resulting in a different deflection. By choosing adsorbed probe molecules that recognize specific molecules, it may be possible to detect pathogens and biohazards. In particular, Fritz et al. (Fritz, J.; Baller, M. K.; Lang, H. P.; Rothuizen, H.; Vettiger, P.; Meyer, E.; Guntherodt, H.-J.; Gerber, Ch.; Gimzewski, J. K. Science 2000, 288, 316) and Wu et al. (Wu, G.; Haifeng, J.; Hansen, K.; Thundat, T.; Datar, R.; Cote, R.; Hagan, M. F.; Chakraborty, A. K.; Majumdar, A. Proc. Natl. Acad. Sci. U.S.A. 2001, 98, 1560) show that the presence of an individual sequence of DNA may be identified by observing the change in deflection as hybridization occurs. Also, it has been shown that this platform can detect prostate specific antigen (PSA). However, to exploit this phenomenon for the development of reliable microdevices, it is necessary to understand the origin of the nanomechanical forces that lead to cantilever deflection upon molecular recognition, as well as the dependence of such deflections on the identity and concentration of the target molecule. In this paper, we present a model with which we examine cantilever deflections resulting from adsorption and subsequent hybridization of DNA molecules. Using an empirical potential, we predict deflections upon hybridization that are consistent with experimental results. We find that the dominant contribution to these deflections arises from hydration forces, not conformational entropy or electrostatics. Cantilever deflections upon adsorption of single stranded DNA are smaller that those predicted after hybridization for reasonable interaction strengths. This is consistent with results in Fritz et al., but not those in Wit et al. The deflections predicted for DNA before and after hybridization are strongly dependent on surface coverage, as well as the degree of disorder on the surface. We argue that self-assembly of probe molecules on the cantilever surface must be carefully controlled and characterized for the realization of microdevices for pathogen detection that rely on nanomechanical forces generated by molecular recognition. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Chakraborty, AK (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Hagan, Michael/N-2177-2014 OI Hagan, Michael/0000-0002-9211-2434 NR 50 TC 106 Z9 116 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 3 PY 2002 VL 106 IS 39 BP 10163 EP 10173 DI 10.1021/jp020972o PG 11 WC Chemistry, Physical SC Chemistry GA 598JV UT WOS:000178273500027 ER PT J AU Damjanovic, A Vaswani, HM Fromme, P Fleming, GR AF Damjanovic, A Vaswani, HM Fromme, P Fleming, GR TI Chlorophyll excitations in photosystem I of Synechococcus elongatus SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LIGHT-HARVESTING COMPLEX; DIFFERENTIAL-OVERLAP TECHNIQUE; ENERGY-TRANSFER; PURPLE BACTERIA; ELECTRONIC-STRUCTURE; CHARGE SEPARATION; RHODOPSEUDOMONAS-VIRIDIS; RHODOBACTER-SPHAEROIDES; THEORETICAL-EXAMINATION; INTERMEDIATE NEGLECT AB The Q(y) excitation energies of the 96 chlorophyll molecules in photosystem I of Synechococcus elongatus, both in and out of their protein environments, were obtained by using the semiempirical INDO/S method and the crystal structure geometries. The dipole-dipole approximation was used to calculate the coupling between the Q(y) states of chlorophylls; in the case of closely separated chlorophylls INDO/S dimer calculations were used to determine the couplings. The effective Hamiltonian for chlorophyll Q(y) excitations was constructed, enabling tentative assignment of red chlorophylls and calculation of the absorption spectrum of PSI. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Tech Univ Berlin, Max Volmer Lab Biophys Chem & Biochem, Berlin, Germany. Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. RP Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 52 TC 106 Z9 114 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 3 PY 2002 VL 106 IS 39 BP 10251 EP 10262 DI 10.1021/jp020963f PG 12 WC Chemistry, Physical SC Chemistry GA 598JV UT WOS:000178273500039 ER PT J AU Link, JM Reyes, M Yager, PM Anjos, JC Bediaga, I Gobel, C Magnin, J Massafferri, A de Miranda, JM Pepe, IM dos Reis, AC Carrillo, S Casimiro, E Cuautle, E Sanchez-Hernandez, A Uribe, C Vazquez, F Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Ramirez, JE Segoni, I Butler, JN Cheung, HWK Chiodini, G Gaines, I Garbincius, PH Garren, LA Gottschalk, E Kasper, PH Kreymer, AE Kutschke, R Benussi, L Bianco, S Fabbri, FL Zallo, A Cawlfield, C Kim, DY Park, KS Rahimi, A Wiss, J Gardner, R Kryemadhi, A Chang, CH Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Cho, K Park, H Alimonti, G Barberis, S Cerutti, A Boschini, M D'Angelo, P DiCorato, M Dini, P Edera, L Erba, S Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Moroni, L Pedrini, D Pontoglio, C Prelz, F Rovere, M Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, MM Pantea, D Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Mendez, H Mendez, L Montiel, E Olaya, D Paris, A Quinones, J Rivera, C Xiong, W Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M AF Link, JM Reyes, M Yager, PM Anjos, JC Bediaga, I Gobel, C Magnin, J Massafferri, A de Miranda, JM Pepe, IM dos Reis, AC Carrillo, S Casimiro, E Cuautle, E Sanchez-Hernandez, A Uribe, C Vazquez, F Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Ramirez, JE Segoni, I Butler, JN Cheung, HWK Chiodini, G Gaines, I Garbincius, PH Garren, LA Gottschalk, E Kasper, PH Kreymer, AE Kutschke, R Benussi, L Bianco, S Fabbri, FL Zallo, A Cawlfield, C Kim, DY Park, KS Rahimi, A Wiss, J Gardner, R Kryemadhi, A Chang, CH Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Cho, K Park, H Alimonti, G Barberis, S Cerutti, A Boschini, M D'Angelo, P DiCorato, M Dini, P Edera, L Erba, S Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Moroni, L Pedrini, D Pontoglio, C Prelz, F Rovere, M Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, MM Pantea, D Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Mendez, H Mendez, L Montiel, E Olaya, D Paris, A Quinones, J Rivera, C Xiong, W Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M CA FOCUS Collaboration TI Observation of a 1750 MeV/c(2) enhancement in the diffractive photoproduction of K+K- SO PHYSICS LETTERS B LA English DT Article ID RELATIVIZED QUARK-MODEL; VECTOR-MESON; ANNIHILATION; DECAYS; STATES AB Using the FOCUS spectrometer with photon beam energies between 20 and 160 GeV, we confirm the existence of a diffractively photoproduced enhancement in K+K- at 1750 MeV/c(2) with nearly 100 times the statistics of previous experiments. Assuming this enhancement to be a single resonance with a Breit-Wigner mass shape, we determine its mass to be 1753.5 +/- 1.5 +/- 2.3 MeV/c(2) and its width to be 122.2 +/- 6.2 +/- 8.0 MeV/c(2). We find no corresponding enhancement at 1750 MeV/c(2) in K*K, and again neglecting any possible interference effects we place limits on the ratio Gamma(X(1750) --> K*K)/Gamma(X(1750) --> K+K-). Our results are consistent with previous photoproduction experiments, but, because of the much greater statistics, challenge the common interpretation of this enhancement as the phi(1680) seen in e(+)e(-) annihilation experiments. (C) 2002 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. Univ Colorado, Boulder, CO 80309 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Illinois, Urbana, IL 61801 USA. Indiana Univ, Bloomington, IN 47405 USA. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu 702701, South Korea. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Milan, Milan, Italy. Univ N Carolina, Asheville, NC 28804 USA. 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. RP Link, JM (reprint author), Univ Calif Davis, Davis, CA 95616 USA. RI Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Anjos, Joao/C-8335-2013; Link, Jonathan/L-2560-2013; Benussi, Luigi/O-9684-2014; Gobel Burlamaqui de Mello, Carla /H-4721-2016; Menasce, Dario Livio/A-2168-2016; OI Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Benussi, Luigi/0000-0002-2363-8889; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Menasce, Dario Livio/0000-0002-9918-1686; bianco, stefano/0000-0002-8300-4124; Kryemadhi, Abaz/0000-0002-1240-2803 NR 16 TC 13 Z9 13 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 OCT 3 PY 2002 VL 545 IS 1-2 BP 50 EP 56 AR PII S0370-2693(02)02561-3 DI 10.1016/S0370-2693(02)02561-3 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606WN UT WOS:000178757800007 ER PT J AU Dawson, S Dicus, D Kao, C AF Dawson, S Dicus, D Kao, C TI Searching for the Higgs bosons of minimal supersymmetry with muon pairs and bottom quarks SO PHYSICS LETTERS B LA English DT Article ID QCD CORRECTIONS; HADRON SUPERCOLLIDERS; STANDARD MODEL; PROTON COLLIDERS; FINAL-STATES; LHC; SUPERGRAVITY; DECAYS; FUSION; BREAKING AB The prospects for the discovery of neutral Higgs bosons (phi(0) = H(0), h(0), A(0)) produced with bottom quarks via Higgs decays into muon pairs (pp --> b (b) over bar phi(0) --> b (b) over bar mu(mu) over bar + X) at the CERN LHC are investigated in the minimal supersymmetric model. The complete physics background from the production of b (b) over bar mu(mu) over bar, b (b) over barW(+)W(-) (including t (t) over bar) and jjmu(mu) over bar, j = g, u, d, s, c in the Standard Model is calculated with realistic acceptance cuts. This discovery mode has a simple production mechanism from gg --> b (b) over bar phi(0) with its cross section proportional to 1/cos(2) beta and could provide an opportunity to measure tan beta and the b (b) over bar phi(0) couplings. In addition, we compare the associated discovery mode above with the inclusive discovery channel pp --> phi(0) --> mu(mu) over bar + X. Promising results are found for the CP-odd pseudoscalar (A(0)) and the heavier CP-even scalar (H(0)) Higgs bosons for tan beta equivalent to nu(2)/nu(1) greater than or similar to 14 m(A), m(H) less than or similar to 325 GeV. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Texas, Ctr Particle Phys, Austin, TX 78712 USA. Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. RP Dawson, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM kao@nhn.ou.edu NR 45 TC 26 Z9 26 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 OCT 3 PY 2002 VL 545 IS 1-2 BP 132 EP 138 AR PII S0370-2693(02)02580-7 DI 10.1016/S0370-2693(02)02580-7 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 606WN UT WOS:000178757800018 ER PT J AU Kuznetsov, AE Boldyrev, AI Zhai, HJ Li, X Wang, LS AF Kuznetsov, AE Boldyrev, AI Zhai, HJ Li, X Wang, LS TI Al-6(2-) - Fusion of two aromatic Al-3(-) units. A combined photoelectron spectroscopy and ab initio study of M+[Al-6 (2-)] (M = Li, Na, K, Cu, and Au) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL CLUSTERS; TETRACOORDINATE PLANAR CARBON; DOPED ALUMINUM CLUSTERS; GAUSSIAN-BASIS SETS; ELECTRONIC-STRUCTURE; MAGIC CLUSTERS; IONIZATION-POTENTIALS; CONTAINING MOLECULES; BIMETALLIC CLUSTERS; GREEN-FUNCTION AB Photoelectron spectroscopy is combined with ab initio calculations to elucidate the structure and chemical bonding of a series of MAl6- (M = Li, Na, K, Cu, and Au) bimetallic clusters. Well-resolved photoelectron spectra were obtained for MAl6- (M = Li, Na, Cu, and Au) at several photon energies. The ab initio calculations showed that all of the MAl6- clusters can be viewed as an M+ cation interacting with an Al-6(2-) dianion. Al-6(2-) was found to possess an O-h ground-state structure, and all of the MAl6- clusters possess a C-3v ground-state structure derived from the O-h Al-6(2-). Careful comparison between the photoelectron spectral features and the ab initio one-electron detachment energies allows us to establish firmly the C3v ground-state structures for the MAl6- clusters. A detailed molecular orbital (MO) analysis is conducted for Al-6(2-) and compared with Al-3(-) It Was shown that Al-6(2-) can be considered as the fusion of two Al-3(-) units. We further found that the preferred occupation of those MOs derived from the sums of the empty 2e' MOs of Al-3(-), rather than those derived from the differences between the occupied 2a(1)' and 2a(2)" MOs of Al-3(-), provides the key bonding interactions for the fusion of the two Al-3(-) into Al-6(2-). Because there are only four bonding MOs (one pi and three sigma MOs), an analysis of resonance structures was performed for the OhAl62-. It is shown that every face of the Al-6(2-) octahedron still possesses both pi- and sigma-aromaticity, analogous to Al-3(-), and that in fact Al-6(2-) can be viewed to possess three-dimensional pi- and sigma-aromaticity with a large resonance stabilization. C1 Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 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 Boldyrev, AI (reprint author), Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. EM boldyrev@cc.usu.edu; ls.wang@pnl.gov RI Kuznetsov, Aleksey/F-1345-2010; Boldyrev, Alexander/C-5940-2009; Kuznetsov, Aleksey/E-5099-2015 OI Boldyrev, Alexander/0000-0002-8277-3669; NR 59 TC 112 Z9 114 U1 2 U2 19 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 OCT 2 PY 2002 VL 124 IS 39 BP 11791 EP 11801 DI 10.1021/ja027423g PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 599CT UT WOS:000178317100050 PM 12296747 ER PT J AU Wang, F Hansen, RK Radisky, D Yoneda, T Barcellos-Hoff, MH Petersen, OW Turley, EA Bissell, MJ AF Wang, F Hansen, RK Radisky, D Yoneda, T Barcellos-Hoff, MH Petersen, OW Turley, EA Bissell, MJ TI Phenotypic reversion or death of cancer cells by altering signaling pathways in three-dimensional contexts SO JOURNAL OF THE NATIONAL CANCER INSTITUTE LA English DT Article ID GROWTH-FACTOR RECEPTOR; BREAST EPITHELIAL-CELLS; E-CADHERIN EXPRESSION; MALIGNANT PHENOTYPE; GENE-EXPRESSION; CARCINOMA CELLS; DOWN-REGULATION; KINASE PATHWAY; MAP KINASE; IN-VIVO AB Background: We previously used a three-dimensional (313) reconstituted basement membrane (rBM) assay to demonstrate that tumorigenic HMT-3522 T4-2 human breast cells can be induced to form morphologically normal structures ("reversion") by treatment with inhibitors of 01 integrin, the epidermal growth factor receptor (EGFR), or mitogen-activated protein kinase (MAPK). We have now used this assay to identify reversion and/or death requirements of several more aggressive human breast cancer cell lines. Methods: Breast tumor cell lines MCF7, Hs578T, and MDA-MB-231 were cultured in 3D rBM and treated with inhibitors of beta1 integrin, MAPK, or phosphatidylinositol 3-kinase (PI3K). MDA-MB-231 cells, which lack E-cadherin, were transfected with an E-cadherin cDNA. The extent of reversion was assessed by changes in morphology and polarity, growth in 3D rBM or soft agar, level of invasiveness, and tumor formation in nude mice. Results: All three cell lines showed partial reversion (MCF7 the greatest and Hs578T the least) of tumorigenic properties treated with a single beta1 integrin, MAPK, or PI3K inhibitor. Combined inhibition of 01 integrin and either PI3K or MAPK resulted in nearly complete phenotypic reversion (MDA-MB-231, MCF7) or in cell death (Hs578T). E-cadherin-transfected MDA-MB-231 cells showed partial reversion, but exposure of the transfectants to an inhibitor of beta1 integrin, PI3K, or MAPK led to nearly complete reversion. Conclusion: The 3D rBM assay can be used to identify signaling pathways that, when manipulated in concert, can lead to the restoration of morphologically normal breast structures or to death of the tumor cells, even highly metastatic cells. This approach may be useful to design therapeutic intervention strategies for aggressive breast cancers. C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Texas, Hlth Sci Ctr, Dept Med, San Antonio, TX 78284 USA. Univ Copenhagen, Panum Inst, Inst Med Anat, Struct Cell Biol Unit, DK-2200 Copenhagen, Denmark. London Reg Canc Ctr, London, ON N6A 4L6, Canada. RP Bissell, MJ (reprint author), Lawrence Berkeley Natl Lab, Div Life Sci, 1 Cyclotron Rd 83-101, Berkeley, CA 94720 USA. RI Wang, Fei/A-7968-2013 FU NCI NIH HHS [CA64786, CA63528, R01 CA057621, R01 CA057621-11, R01 CA064786, R01 CA064786-05, R37 CA064786, U01 CA143233, U01 CA143233-02, U54 CA112970, U54 CA112970-02, U54 CA126552, U54 CA126552-02, U54 CA143836, U54 CA143836-02] NR 50 TC 178 Z9 185 U1 0 U2 6 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0027-8874 J9 J NATL CANCER I JI J. Natl. Cancer Inst. PD OCT 2 PY 2002 VL 94 IS 19 BP 1494 EP 1503 PG 10 WC Oncology SC Oncology GA 598RA UT WOS:000178289300015 PM 12359858 ER PT J AU Howard, SK Gaba, DM Rosekind, MR Zarcone, VP AF Howard, SK Gaba, DM Rosekind, MR Zarcone, VP TI The risks and implications of excessive daytime sleepiness in resident physicians SO ACADEMIC MEDICINE LA English DT Article ID DEPRIVATION; PERFORMANCE; DISORDERS AB Purpose. To assess the levels of physiologic and subjective sleepiness in residents in three conditions: (1) during a normal (baseline) work schedule, (2) after an in-hospital 24-hour on-call period, and (3) following a period of extended sleep. Method. In 1996, a within-subjects, repeated-measures study was performed with a volunteer sample of 11 anesthesia residents from the Stanford University School of Medicine using three separate experimental conditions. Sixteen residents were recruited and 11 of the 16 completed the three separate experimental conditions. Daytime sleepiness was assessed using the Multiple Sleep Latency Test (MSLT). Results. MSLT scores were shorter in the baseline (6-7 min) and post-call (4.9 min) conditions, compared with the extended-sleep condition (12 min, p = .0001) and there was no significant difference between the baseline and post-call conditions (p = .07). There was a significant main effect for both condition (p = .0001) and time of day (p = .0003). Subjects were inaccurate in subjectively identifying sleep onset compared with EEG measures (incorrect on 49% of EEG-determined sleep episodes). Conclusion. Residents' daytime sleepiness in both baseline and post-call conditions was near or below levels associated with clinical sleep disorders. Extending sleep time resulted in normal levels of daytime sleepiness. The residents were subjectively inaccurate determining EEG-defined sleep onset. Based on the findings from this and other studies, reforms of residents' work and duty hours are justified. C1 VA Palo Alto Hlth Care Syst, Patient Safety Ctr Inquiry, Palo Alto, CA 94304 USA. Stanford Univ, Sch Med, Dept Anesthesia, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Fatigue Countermeasures Program, Ames, IA USA. RP Howard, SK (reprint author), VA Palo Alto Hlth Care Syst, Patient Safety Ctr Inquiry, 112A,3801 Miranda Ave, Palo Alto, CA 94304 USA. OI Howard, Steven/0000-0001-6475-1792 NR 29 TC 91 Z9 100 U1 0 U2 1 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1040-2446 J9 ACAD MED JI Acad. Med. PD OCT PY 2002 VL 77 IS 10 BP 1019 EP 1025 DI 10.1097/00001888-200210000-00015 PG 7 WC Education, Scientific Disciplines; Health Care Sciences & Services SC Education & Educational Research; Health Care Sciences & Services GA 617MP UT WOS:000179365700013 PM 12377678 ER PT J AU Rupp, B Segelke, BW Krupka, HI Lekin, TP Schafer, J Zemla, A Toppani, D Snell, G Earnest, T AF Rupp, B Segelke, BW Krupka, HI Lekin, TP Schafer, J Zemla, A Toppani, D Snell, G Earnest, T TI The TB structural genomics consortium crystallization facility: towards automation from protein to electron density SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 9th International Conference on the Crystallization of Biological Macromolecules CY MAR 23-28, 2002 CL JENA, GERMANY DE high throughput crystallization; structural genomics; crystallization screening; molecular replacement; phase bias removal ID MOLECULAR REPLACEMENT; MAXIMUM-LIKELIHOOD; REFINEMENT; MODELS; SEARCH AB The crystallization facility of the TB (Tuberculosis) structural genomics consortium, one of nine NIH sponsored P50 structural genomic centres, provides TB consortium members with automated crystallization, data collection and basic molecular replacement (MR) structure solution up to bias minimized electron density maps. Crystallization setup of up to ten proteins per day follows the CRYSTOOL combinatorial screen protocol using a modular and affordable robotic design with an open architecture. Components include screen preparation, plate setup, automated image acquisition and analysis, and optimisation design. A new 96 well crystallization plate has been designed for optimal robotic handling while maintaining ease of manual crystal harvesting. Robotic crystal mounting, screening, and data collection are conducted in-house and at the Advanced Light Source (ALS) in Berkeley. A simple automated protocol based on MR and homology based structure prediction automatically solves modestly difficult problems. Multiple search models are evaluated in parallel MR and the best multi-segment rigid body refined MR solution is subjected to simulated annealing torsion angle molecular dynamics using CNS, bringing even marginal MR solutions within the convergence radius of the subsequent highly effective bias removal and map reconstruction protocol, Shake& wARP, used to generate electron density for initial rebuilding. Real space correlation plots allow rapid assessment of local structure quality. Modular design of robotics and automated scripts using publicly available programs for structure solution allow for efficient high throughput crystallography - at a reasonable cost. C1 Lawrence Livermore Natl Lab, Macromol Crystallog & TB Struct Genom Consortium, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Ctr Struct Biol, Berkeley, CA 94720 USA. RP Rupp, B (reprint author), Lawrence Livermore Natl Lab, Macromol Crystallog & TB Struct Genom Consortium, Livermore, CA 94551 USA. FU NIGMS NIH HHS [P50 GM62410] NR 23 TC 57 Z9 62 U1 1 U2 4 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD OCT PY 2002 VL 58 SI 1 BP 1514 EP 1518 DI 10.1107/S0907444902014282 PN 10 PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 597YH UT WOS:000178248000002 PM 12351851 ER PT J AU Krupka, HI Rupp, B Segelke, BW Lekin, TP Wright, D Wu, HC Todd, P Azarani, A AF Krupka, HI Rupp, B Segelke, BW Lekin, TP Wright, D Wu, HC Todd, P Azarani, A TI The high-speed Hydra-Plus-One system for automated high-throughput protein crystallography SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 9th International Conference on the Crystallization of Biological Macromolecules CY MAR 23-28, 2002 CL JENA, GERMANY DE automation; crystallization; high-throughput; Hydra (R); liquid-handling system ID CRYSTALLIZATION AB An automated high-throughput dispenser has been developed for the setup of protein crystallization trials by vapor diffusion or Microbatch methods. The Hydra(R)-Plus-One is composed of a Hydra(R)-PP system equipped with a motorized XYZ-platform, 96 precision glass syringes and a single-channel microsolenoid dispenser, which transfers 100nl-50mul of protein solution with an accuracy of > 90% at a speed of 60s per 96 wells. Up to 300mul of premixed cocktails can be aspirated with the 96-syringe-assembly and dispensed into reservoir and droplet wells within 60s. The Hydra(R)-Plus-One combines high precision, reliability and speed in a cost- effective high-throughput system ideally suited for protein crystallization. C1 Lawrence Livermore Natl Lab, Macromol Crystallog & TB Struct Genom Consortium, Livermore, CA 94551 USA. Robbins Sci Corp, Sunnyvale, CA 94089 USA. RP Rupp, B (reprint author), Lawrence Livermore Natl Lab, Macromol Crystallog & TB Struct Genom Consortium, Livermore, CA 94551 USA. FU NIGMS NIH HHS [P50 GM62410] NR 6 TC 44 Z9 48 U1 0 U2 4 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD OCT PY 2002 VL 58 SI 1 BP 1523 EP 1526 DI 10.1107/S090744490201435X PN 10 PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 597YH UT WOS:000178248000004 PM 12351853 ER PT J AU McLerran, L AF McLerran, L TI The color glass condensate RHIC and HERA SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 10th International Workshop on Deep Inelastic Scattering (DIS2002) CY APR 30-MAY 04, 2002 CL KRAKOW, POLAND SP Deutsch Electronen-Synchrotron DESY, Polish Acad Atrs & Sci ID DEEP-INELASTIC SCATTERING; NUCLEAR COLLISIONS; GLUON PRODUCTION; SATURATION AB In this talk, I discuss a universal form of matter, the Color Glass Condensate. It is this matter which composes the low x part of all hadronic wavefunctions. The experimental programs at RHIC and HERA, and future programs at LHC and eRHIC may allow us to probe and study the properties of this matter. C1 Brookhaven Natl Lab, Nucl Theory Grp, Upton, NY 11793 USA. RP McLerran, L (reprint author), Brookhaven Natl Lab, Nucl Theory Grp, Upton, NY 11793 USA. NR 18 TC 4 Z9 4 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 OCT PY 2002 VL 33 IS 10 BP 2859 EP 2865 PG 7 WC Physics, Multidisciplinary SC Physics GA 608TE UT WOS:000178862100011 ER PT J AU Albino, S Klasen, M AF Albino, S Klasen, M TI Strong coupling constant from the photon structure function SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 10th International Workshop on Deep Inelastic Scattering (DIS2002) CY APR 30-MAY 04, 2002 CL KRAKOW, POLAND SP Deutsch Electronen-Synchrotron DESY, Polish Acad Atrs & Sci ID STRUCTURE-FUNCTION F-2(GAMMA); PARTON DISTRIBUTIONS; Q2; GEV2 AB We extract the value of the strong coupling constant a from a single-parameter pointlike fit to the photon structure function F-2(gamma) at large x and Q(2) and from a first five-parameter full (pointlike and hadronic) fit to the complete F-2(gamma) data set taken at PETRA, TRISTAN, and LEP. In next-to-leading order and the (MS) over bar renormalization and factorization schemes, we obtain alpha(s)(m(Z)) = 0.1183 +/- 0.0050(exp.)(-0.0028)(+0.0029)(theor.) [pointlike] and alpha(s)(m(Z)) = 0.1198 +/- 0.0028(exp.)(-0.0046)(+0.0034) (theor.) [pointlike and hadronic]. We demonstrate that the data taken at LEP have reduced the experimental error by about a factor of two, so that a competitive determination of a, from F-2(gamma) is now possible. C1 Univ Hamburg, Inst Theoret Phys 2, D-22761 Hamburg, Germany. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Albino, S (reprint author), Univ Hamburg, Inst Theoret Phys 2, Luruper Chaussee 149, D-22761 Hamburg, Germany. NR 25 TC 1 Z9 1 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 OCT PY 2002 VL 33 IS 10 BP 2939 EP 2945 PG 7 WC Physics, Multidisciplinary SC Physics GA 608TE UT WOS:000178862100024 ER PT J AU Lee, J AF Lee, J TI Polarization of prompt J/psi and Upsilon(nS) SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 10th International Workshop on Deep Inelastic Scattering (DIS2002) CY APR 30-MAY 04, 2002 CL KRAKOW, POLAND SP Deutsch Electronen-Synchrotron DESY, Polish Acad Atrs & Sci ID WAVE CHARMONIUM PRODUCTIONS; OCTET QUARKONIUM PRODUCTION; FERMILAB-TEVATRON; HEAVY QUARKONIUM; PSI' POLARIZATION; QCD ANALYSIS; B-DECAY; COLOR; LEP; PHOTOPRODUCTION AB We review predictions, based on the nonrelativistic QCD factorization framework, for the polarizations of prompt J/psi's and r(nS)'s produced at the Fermilab Tevatron. We also discuss the effect of relativistic corrections on the theoretical prediction for the polarization of prompt J/psi's at the Tevatron. C1 Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. RP Lee, J (reprint author), Argonne Natl Lab, HEP Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 36 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 OCT PY 2002 VL 33 IS 10 BP 3237 EP 3241 PG 5 WC Physics, Multidisciplinary SC Physics GA 608TE UT WOS:000178862100070 ER PT J AU Lonnblad, L Repond, J Zielinski, M AF Lonnblad, L Repond, J Zielinski, M TI Multi-hadron final states SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 10th International Workshop on Deep Inelastic Scattering (DIS2002) CY APR 30-MAY 04, 2002 CL KRAKOW, POLAND SP Deutsch Electronen-Synchrotron DESY, Polish Acad Atrs & Sci ID DEEP-INELASTIC SCATTERING; COLOR DIPOLE MODEL; CROSS-SECTIONS; QCD; HERA; DISTRIBUTIONS; SIMULATION; ALGORITHM; COHERENCE; CASCADE AB This summary aims to highlight major results and insights gained from recent studies of hadronic final states in ep, p (p) over bar, e(+)e(-), as well as relevant theoretical developments, presented in the Multi-Hadron Final States parallel sessions of the DIS2002 workshop held in Krakow, Poland in May 2002. C1 Lund Univ, Dept Theoret Phys, S-22362 Lund, Sweden. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. RP Lonnblad, L (reprint author), Lund Univ, Dept Theoret Phys, Solvegatan 14A, S-22362 Lund, Sweden. OI Lonnblad, Leif/0000-0003-1269-1649 NR 90 TC 1 Z9 1 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 OCT PY 2002 VL 33 IS 10 BP 3329 EP 3347 PG 19 WC Physics, Multidisciplinary SC Physics GA 608TE UT WOS:000178862100085 ER PT J AU Zhang, W Wilder, JW Smith, DH AF Zhang, W Wilder, JW Smith, DH TI Interpretation of ethane hydrate equilibrium data for porous media involving hydrate-ice equilibria SO AICHE JOURNAL LA English DT Article ID PORE-SIZE DISTRIBUTIONS; THERMODYNAMIC PROPERTIES; METHANE AB Equilibrium pressures for the dissociation of ethane hydrate confined in silica gel pores of nominal radii 7.5, 5.0 or 3.0 nm were measured over a range of temperatures. Each of these porous media contained a broad distribution of pore radii. At higher temperatures, the pressures were larger than previously reported for bulk hydrates, and generally increased with a decrease in nominal pore radius for those data where the equilibria involved liquid water. However, at the lowest temperatures (where the equilibria involved ice), the pressures were identical (within expected experimental uncertainties) for all three silica gels and the same as reported by various authors for the bulk hydrate. The lack of any dependence of the equilibrium pressure on pore size at the lowest temperatures (where the equilibrium involves ethane hydrate, ethane gas, and ice) indicates that, below the quadruple point temperature of the smallest pore in which hydrate formed, there is no detectable effects on the equilibrium pressure due to the restricted geometries of the porous media. It suggests that the interface relevant to the formation of hydrate in silica gel pores is that between the hydrate and aqueous phase (Henry et al., 1999) and that within experimental error the surface energy between the hydrate and aqueous phase can be approximated by that between ice and the appropriate aqueous phase. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. W Virginia Univ, Dept Chem Engn, Morgantown, WV 26506 USA. W Virginia Univ, Dept Math, Morgantown, WV 26506 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Wilder, JW (reprint author), US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. NR 19 TC 36 Z9 39 U1 5 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0001-1541 EI 1547-5905 J9 AICHE J JI AICHE J. PD OCT PY 2002 VL 48 IS 10 BP 2324 EP 2331 DI 10.1002/aic.690481022 PG 8 WC Engineering, Chemical SC Engineering GA 604QU UT WOS:000178633200020 ER PT J AU Richter, HE Walch, A Smida, J Hieber, L Lengfelder, E Demidchik, EP Weier, HU Zitzelsberger, H AF Richter, HE Walch, A Smida, J Hieber, L Lengfelder, E Demidchik, EP Weier, HU Zitzelsberger, H TI Chromosomal imbalances and RET rearrangements in radiation-induced thyroid tumors. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract CT 52nd Annual Meeting of the American-Society-of-Human-Genetics CY OCT 15-19, 2002 CL BALTIMORE, MARYLAND SP Amer Soc Human Genet, NICHHD, NCI, NIMH, Affymetrix Inc, Gentra Syst, NIDCD C1 GSF, Natl Res Ctr Environm & Hlth, Inst Mol Radiobiol, Neuherberg, Germany. Tech Univ Munich, Inst Pathol, D-8000 Munich, Germany. Univ Munich, Radiobiol Inst, Munich, Germany. Ctr Thyroid Tumours, Minsk, Byelarus. Univ Calif Berkeley, Dept Subcellular Struct, Div Life Sci, EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Walch, Axel/B-4554-2012; Smida, Jan/P-2486-2014 OI Walch, Axel/0000-0001-5578-4023; NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2002 VL 71 IS 4 SU S MA 320 BP 226 EP 226 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 594AC UT WOS:000178025800319 ER PT J AU Gakh, O Park, S Mooney, SM O'Neill, HA Nichol, HK Pickering, IJ George, GN Mangravita, A Ferreira, GC Isaya, G AF Gakh, O Park, S Mooney, SM O'Neill, HA Nichol, HK Pickering, IJ George, GN Mangravita, A Ferreira, GC Isaya, G TI Ferroxidase activity of frataxin, the protein deficient in Friedreich ataxia SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract CT 52nd Annual Meeting of the American-Society-of-Human-Genetics CY OCT 15-19, 2002 CL BALTIMORE, MARYLAND SP Amer Soc Human Genet, NICHHD, NCI, NIMH, Affymetrix Inc, Gentra Syst, NIDCD C1 Mayo Clin, Dept Pediat & Adolescent Med, Rochester, MN USA. SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA USA. Univ S Florida, Dept Biochem & Mol Biol, Tampa, FL USA. RI Ferreira, Gloria/A-4709-2012; George, Graham/E-3290-2013; Pickering, Ingrid/A-4547-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2002 VL 71 IS 4 SU S MA 931 BP 331 EP 331 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 594AC UT WOS:000178025800931 ER PT J AU Yu, A Chen, J Rusch, T Fieweger, K Chudyk, J Doktycz, M Hicks, S Dickinson, W Ghebranious, N Weber, JL AF Yu, A Chen, J Rusch, T Fieweger, K Chudyk, J Doktycz, M Hicks, S Dickinson, W Ghebranious, N Weber, JL TI Submicroliter genotyping of diallelic polymorphisms in microtope. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract CT 52nd Annual Meeting of the American-Society-of-Human-Genetics CY OCT 15-19, 2002 CL BALTIMORE, MARYLAND SP Amer Soc Human Genet, NICHHD, NCI, NIMH, Affymetrix Inc, Gentra Syst, NIDCD C1 Marshfield Med Res Fdn, Ctr Med Genet, Marshfield, WI 54449 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2002 VL 71 IS 4 SU S MA 1716 BP 463 EP 463 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 594AC UT WOS:000178025801718 ER PT J AU Altherr, MR Wachocki, S Brettin, T Gottardo, R Iyer, R Robison, RA Ettinger, JM AF Altherr, MR Wachocki, S Brettin, T Gottardo, R Iyer, R Robison, RA Ettinger, JM TI Human genetic response to Bacillus anthracis spores. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract CT 52nd Annual Meeting of the American-Society-of-Human-Genetics CY OCT 15-19, 2002 CL BALTIMORE, MARYLAND SP Amer Soc Human Genet, NICHHD, NCI, NIMH, Affymetrix Inc, Gentra Syst, NIDCD C1 BYU, Dept Micro, Provo, UT USA. Los Alamos Natl Lab, NIS Div, Los Alamos, NM USA. Los Alamos Natl Lab, B Div, Los Alamos, NM USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2002 VL 71 IS 4 SU S MA 1944 BP 501 EP 501 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 594AC UT WOS:000178025801944 ER PT J AU Kunz-Schughart, LA Freyer, JP AF Kunz-Schughart, LA Freyer, JP TI Phosphorous metabolites and steady-state energetics of transformed fibroblasts during three-dimensional growth SO AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY LA English DT Article DE energy metabolism; tumor biology; nuclear magnetic resonance spectroscopy; phospholipids; quiescence ID MAGNETIC-RESONANCE SPECTROSCOPY; P-31 NMR-SPECTROSCOPY; MULTICELLULAR TUMOR SPHEROIDS; BREAST-CANCER CELLS; IN-VIVO; PHOSPHOLIPID-METABOLISM; MR SPECTROSCOPY; PHOSPHOGLYCERIDE METABOLISM; RADIOBIOLOGICAL HYPOXIA; MITOCHONDRIAL-FUNCTION AB Rat1-T1 and MR1 spheroids represent separate transformed phenotypes originated from the same rat fibroblasts that differ in three-dimensional (3D) growth kinetics, histological structure, and oxygenation status. In the present study, P-31-NMR spectroscopy of perfused spheroid suspensions was used to investigate cellular energetics relative to 3D growth, development of necrosis, and cell cycle distribution. Both spheroid types were characterized by a remarkably low amount of free (inorganic) phosphate (Pi) and a low phosphocreatine peak. The ratio of nucleoside triphosphate (NTP) to P-i ranged between 1.5 and 2.0. Intracellular pH, NTP-to-P-i ratio, and NTP/cell remained constant throughout spheroid growth, being unaffected by the emergence of oxygen deficiency, cell quiescence, and necrosis. However, a 50% decrease in the ratio of the lipid precursors phosphorylcholine and phosphorylethanolamine (PC/PE) was observed with increasing spheroid size and was correlated with an increased G(1)/G(0) phase cell fraction. In addition, the ratio of the phospholipid degradation products glycerophosphorylcholine and glycerophosphorylethanolamine (GPC/GPE) increased with spheroid diameter in Rat1-T1 aggregates. We conclude that changes in phospholipid metabolism, rather than alterations in energy-rich phosphates, reflect cell quiescence in spheroid cultures, because cells in the inner oxygen-deficient zones seem to adapt their energy metabolism to the environmental conditions before necrotic cell destruction. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Regensburg, Inst Pathol, D-93042 Regensburg, Germany. RP Freyer, JP (reprint author), Los Alamos Natl Lab, Biosci Div, POB 1663, Los Alamos, NM 87545 USA. FU NCI NIH HHS [CA 51150] NR 87 TC 5 Z9 5 U1 0 U2 2 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0363-6143 J9 AM J PHYSIOL-CELL PH JI Am. J. Physiol.-Cell Physiol. PD OCT PY 2002 VL 283 IS 4 BP C1287 EP C1297 DI 10.1152/ajpcell.00097.2002 PG 11 WC Cell Biology; Physiology SC Cell Biology; Physiology GA 592UE UT WOS:000177954600027 PM 12225991 ER PT J AU Goldstein, RZ Volkow, ND AF Goldstein, RZ Volkow, ND TI Drug addiction and its underlying neurobiological basis: Neuroimaging evidence for the involvement of the frontal cortex SO AMERICAN JOURNAL OF PSYCHIATRY LA English DT Review ID CEREBRAL BLOOD-FLOW; BRAIN GLUCOSE-METABOLISM; FUNCTIONAL MAGNETIC-RESONANCE; POSITRON EMISSION TOMOGRAPHY; PROGRESSIVE RATIO SCHEDULE; ANTERIOR CINGULATE CORTEX; PREFRONTAL CORTEX; ORBITOFRONTAL CORTEX; NUCLEUS-ACCUMBENS; COCAINE ABUSERS AB Objective: Studies of the neurobiological processes underlying drug addiction primarily have focused on limbic subcortical structures. Here the authors evaluated the role of frontal cortical structures in drug addiction. Method: An integrated model of drug addiction that encompasses intoxication, bingeing, withdrawal, and craving is proposed. This model and findings from neuroirnaging studies on the behavioral, cognitive, and emotional processes that are at the core of drug addiction were used to analyze the involvement of frontal structures in drug addiction. Results: The orbitofrontal cortex and the anterior cingulate gyrus, which are regions neuroanatomically connected with limbic structures, are the frontal cortical areas most frequently implicated in drug addiction. They are activated in addicted subjects during intoxication, craving, and bingeing, and they are deactivated during withdrawal. These regions are also involved in higher-order cognitive and motivational functions, such as the ability to track, update, and modulate the salience of a reinforcer as a function of context and expectation and the ability to control and inhibit prepotent responses. Conclusions: These results imply that addiction connotes cortically regulated cognitive and emotional processes, which result in the overvaluing of drug reinforcers, the undervaluing of alternative reinforcers, and deficits in inhibitory control for drug responses. These changes in addiction, which the authors call I-RISA (impaired response inhibition and salience attribution), expand the traditional concepts of drug dependence that emphasize limbic-regulated responses to pleasure and reward. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Goldstein, RZ (reprint author), Brookhaven Natl Lab, Bldg 490,30 Bell Ave, Upton, NY 11973 USA. FU NIAAA NIH HHS [AA 09481, R01 AA009481]; NIDA NIH HHS [DA 06891, K23 DA015517, R01 DA006891] NR 103 TC 1220 Z9 1256 U1 25 U2 171 PU AMER PSYCHIATRIC PRESS, INC PI WASHINGTON PA 1400 K ST, N W, STE 1101, WASHINGTON, DC 20005 USA SN 0002-953X J9 AM J PSYCHIAT JI Am. J. Psychiat. PD OCT PY 2002 VL 159 IS 10 BP 1642 EP 1652 DI 10.1176/appi.ajp.159.10.1642 PG 11 WC Psychiatry SC Psychiatry GA 600GR UT WOS:000178382700005 PM 12359667 ER PT J AU Volpe, A AF Volpe, A TI Dynamic ocean assay of trace elements with ICP-MS SO AMERICAN LABORATORY LA English DT Article ID PLASMA-MASS-SPECTROMETRY; ONLINE PRECONCENTRATION; FLOW-INJECTION; SEA-WATER; METALS AB The, sensitivity achieved by the ICP-MS permits a more detailed study of trace elements in the world's oceans. This paper describes a study of the relationships between the oceanic distribution and concentration of trace elements and variations in biological productivity, geological activity, weather and climate, and other significant environmental effects. C1 Lawrence Livermore Natl Lab, Strateg Syst Support Program, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, ICP MS Facil, Isotope Sci Div, Livermore, CA 94550 USA. RP Volpe, A (reprint author), Lawrence Livermore Natl Lab, Strateg Syst Support Program, POB 808,L-016, Livermore, CA 94550 USA. NR 10 TC 0 Z9 0 U1 0 U2 2 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 USA SN 0044-7749 J9 AM LAB JI Am. Lab. PD OCT PY 2002 VL 34 IS 20 BP 30 EP + PG 5 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 610ZG UT WOS:000178991500005 ER PT J AU Manceau, A Tamura, N Marcus, MA MacDowell, AA Celestre, RS Sublett, RE Sposito, G Padmore, HA AF Manceau, A Tamura, N Marcus, MA MacDowell, AA Celestre, RS Sublett, RE Sposito, G Padmore, HA TI Deciphering Ni sequestration in soil ferromanganese nodules by combining X-ray fluorescence, absorption, and diffraction at micrometer scales of resolution SO AMERICAN MINERALOGIST LA English DT Article ID SEQUENTIAL EXTRACTION; CRYSTAL-CHEMISTRY; HEAVY-METALS; IRON; CONCRETIONS; SPECIATION; NICKEL; MINERALS AB X-ray microprobes are among the most important new analytical techniques to emerge from third generation synchrotron facilities. Here we show how X-ray fluorescence, diffraction, and absorption can be used in parallel to determine the structural form of trace elements in heterogeneous matrices at the micrometer-scale of resolution. Scanning X-ray microfluorescence (muSXRF) and microdiffraction (muSXRD) first are used to identify the host solid phase by mapping the distributions of elements and solid species, respectively. Micro-extended X-ray absorption fine structure (muEXAFS) spectroscopy is then used to determine the mechanism of trace element binding by the host phase at the molecular scale. To illustrate the complementary application of these three techniques, we studied how nickel is sequestered in soil ferromanganese nodules, an overwhelmingly complex natural matrix consisting of submicrometer to nanometer sized particles with varying structures and chemical compositions. We show that nickel substitutes for Mn(3+) in the manganese layer of the MnO(2)-Al(OH)(3) mixed-layer oxide lithiophorite. The affinity of Ni for lithiophorite was characteristic of micronodules sampled from soils across the U.S.A. and Europe. Since many natural and synthetic materials are heterogeneous at nanometer to micrometer scales, the synergistic use of muSXRF, muSXRD, and muEXAFS is expected to have broad applications to earth and materials science. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Grenoble 1, Environm Geochem Grp, LGIT, F-38041 Grenoble 9, France. CNRS, F-38041 Grenoble 9, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Geochem, Div Earth Sci, Berkeley, CA 94720 USA. RP Manceau, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM Alain.Manceau@ujf-grenoble.fr RI MacDowell, Alastair/K-4211-2012 NR 35 TC 78 Z9 80 U1 0 U2 12 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 OCT PY 2002 VL 87 IS 10 BP 1494 EP 1499 PG 6 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 604QE UT WOS:000178631900028 ER PT J AU Hasselbrink, EF Shepodd, TJ Rehm, JE AF Hasselbrink, EF Shepodd, TJ Rehm, JE TI High-pressure microfluidic control in lab-on-a-chip devices using mobile polymer monoliths SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY ELECTROCHROMATOGRAPHY; SOFT LITHOGRAPHY; ANALYSIS SYSTEMS; FLOW-CONTROL; MICROVALVE; SEPARATION; VALVE AB We have developed a nonstick polymer formulation for creating moving parts inside of microfluidic channels and have applied the technique to create piston-based devices that overcome several microfluidic flow control challenges. The parts were created by completely filling the channels of a glass microfluidic chip with the monomer/ solvent/initiator components of a nonstick photopolymer and then selectively exposing the chip to UV light in order to define mobile pistons (or other quasi-two-dimensional shapes) inside the channels. Stops defined in the substrate prevent the part from flushing out of the device but also provide sealing surfaces so that valves and other flow control devices are possible. Sealing against pressures greater than 30 MPa (4500 psi) and actuation times less than 33 ms are observed. An on-chip check valve, a diverter valve, and a 10-nL pipet are demonstrated. This valving technology, coupled with high-pressure electrokinetic pumps, should make it possible to create a completely integrated HPLC system on a chip. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Hasselbrink, EF (reprint author), Univ Michigan, Dept Mech Engn, 2250 GG Brown Bldg,2350 Hayward Ave, Ann Arbor, MI 48109 USA. NR 22 TC 66 Z9 68 U1 1 U2 20 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 OCT 1 PY 2002 VL 74 IS 19 BP 4913 EP 4918 DI 10.1021/ac025761u PG 6 WC Chemistry, Analytical SC Chemistry GA 600XY UT WOS:000178418100018 PM 12380812 ER PT J AU Berger, SJ Lee, SW Anderson, GA Pasa-Tolic, L Tolic, N Shen, YF Zhao, R Smith, RD AF Berger, SJ Lee, SW Anderson, GA Pasa-Tolic, L Tolic, N Shen, YF Zhao, R Smith, RD TI High-throughput global peptide proteomic analysis by combining stable isotope amino acid labeling and data-dependent multiplexed-MS/MS SO ANALYTICAL CHEMISTRY LA English DT Article ID FTICR MASS-SPECTROMETRY; CAPILLARY LIQUID-CHROMATOGRAPHY; PROTEIN IDENTIFICATION; QUANTITATIVE-ANALYSIS; AFFINITY TAGS; ELECTROSPRAY; MIXTURES; O-18; COMBINATION; MODEL AB In this work, we describe the application of a stable isotope amino acid (lysine) labeling in conjunction with data-dependent multiplexed tandem mass spectrometry (MS/MS) to facilitate the characterization and identification of peptides from proteomic (global protein) digests. Lysine auxotrophic yeast was grown in the presence of C-13-labeled or unlabeled lysine and combined after harvesting in equal proportions. Endoproteinase LysC digestion of the cytosolic fraction produced a global proteomic sample, consisting of heavy/light labeled peptide pairs. Then data-dependent multiplexed-MS/MS was applied to simultaneously select and dissociate only labeled peptide ion pairs. The approach allows differentiation between N-terminal (e.g., b-type ions) and C-terminal fragment ions (e.g., y-type ions) in resulting tandem mass spectra, as well as the capability of differentiation between near-isobaric glutamine and lysine residues. We also describe the utility of peptide composition and fragment information to support peptide identifications and examine the potential application of lysine labeling for differential quantitative protein analysis. 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, 902 Battelle Blvd,Mail Stop K8-98, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012; Lee, Sang-Won/H-6760-2013 OI Smith, Richard/0000-0002-2381-2349; Lee, Sang-Won/0000-0002-5042-0084 FU NCI NIH HHS [CA 93306] NR 26 TC 54 Z9 56 U1 1 U2 12 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 OCT 1 PY 2002 VL 74 IS 19 BP 4994 EP 5000 DI 10.1021/ac020105f PG 7 WC Chemistry, Analytical SC Chemistry GA 600XY UT WOS:000178418100028 PM 12380822 ER PT J AU Anazawa, T Matsunaga, H Yeung, ES AF Anazawa, T Matsunaga, H Yeung, ES TI Electrophoretic quantitation of nucleic acids without amplification by single-molecule imaging SO ANALYTICAL CHEMISTRY LA English DT Article ID RIBONUCLEASE PROTECTION ASSAY; MESSENGER-RNA QUANTITATION; FLUORESCENCE SPECTROSCOPY; DNA AMPLIFICATION; STRANDED-DNA; PCR; BIOMOLECULES; HYBRIDIZATION; DYNAMICS; PROBES AB We have developed a novel high-performance quantitative assay for unamplified nucleic acids that is based on single-molecule imaging. The apparatus is a simple but highly sensitive single-molecule detection system that uses a normal CCD camera instead of an image-intensified CCD camera. After the DNA molecules in a sample were labeled with YOYO-1, they were induced to migrate electrophoretically in a polymer solution and imaged. No chemical or biochemical amplification was required. Direct quantitation of the sample by counting molecules was possible, because the number counted over the measurement period was directly proportional to the concentration of DNA molecules in the sample. Nonspecifically labeled impurities that would degrade the sensitivity of the assay were successfully reduced and discriminated from the DNA molecules by differences in electrophoretic mobility. By using beta-actin DNA (838 bp) as a model sample, we demonstrate that this protocol was fast (10-min measurement period), highly sensitive (limit of quantitation: similar to10(3) copies/sample, or 3x10(-16) M), quantitative, and covered a wide linear dynamic range (similar to10(4)). This high-performance assay promises to be a powerful technology for the quantitation of specific varieties of mRNA in the study of gene functions and diseases and in the clinical detection of mutant cells. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Hitachi Ltd, Cent Res Lab, Kokubunji, Tokyo 1858601, Japan. RP Yeung, ES (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 31 TC 43 Z9 45 U1 0 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 OCT 1 PY 2002 VL 74 IS 19 BP 5033 EP 5038 DI 10.1021/ac025801u PG 6 WC Chemistry, Analytical SC Chemistry GA 600XY UT WOS:000178418100033 PM 12380827 ER PT J AU Van Berkel, GJ Asano, KG Kertesz, V AF Van Berkel, GJ Asano, KG Kertesz, V TI Enhanced study and control of analyte oxidation in electrospray using a thin-channel, planar electrode emitter SO ANALYTICAL CHEMISTRY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; ION-SOURCE; REDOX REACTIONS; CELL AB A thin-channel, planar electrode emitter device is described and utilized for the study and control of electrochemical oxidation of analytes at the emitter electrode in an electrospray ion source. For analytes that are not particularly susceptible to oxidation, the planar electrode device functions analytically in a manner similar to emitter systems that utilize the more common stainless steel tubular electrodes. For more easily oxidized analytes, the device provides the means to achieve near 100% oxidation efficiency or to completely eliminate analyte oxidation through simple and rapid changes in electrode material, electrode area, electrode covering, channel height above the electrode, or solution flow rate. Compared to the use of tubular electrodes, the planar electrode emitter system provides improved flexibility in altering the nature of the electrode area and material, as well as altering analyte mass transport to the electrode surface. Each of these parameters is critical in the control of electrochemical reactions and can be easily studied or exploited with this emitter electrode configuration. C1 Oak Ridge Natl Lab, Div Chem Sci, Org & Biol Mass Spectrometry Grp, Oak Ridge, TN 37831 USA. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Org & Biol Mass Spectrometry Grp, Oak Ridge, TN 37831 USA. RI Asano, Keiji/L-3164-2016; Kertesz, Vilmos/M-8357-2016 OI Asano, Keiji/0000-0003-2254-3586; Kertesz, Vilmos/0000-0003-0186-5797 NR 21 TC 30 Z9 30 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 2002 VL 74 IS 19 BP 5047 EP 5056 DI 10.1021/ac020267b PG 10 WC Chemistry, Analytical SC Chemistry GA 600XY UT WOS:000178418100035 PM 12380829 ER PT J AU Sani, RK Peyton, BM Smith, WA Apel, WA Petersen, JN AF Sani, RK Peyton, BM Smith, WA Apel, WA Petersen, JN TI Dissimilatory reduction of Cr(VI), Fe(III), and U(VI) by Cellulomonas isolates SO APPLIED MICROBIOLOGY AND BIOTECHNOLOGY LA English DT Article ID HEXAVALENT CHROMIUM REDUCTION; IRON-REDUCING BACTERIA; DESULFOVIBRIO-DESULFURICANS; CHROMATE REDUCTION; ENTEROBACTER-CLOACAE; URANIUM; REMOVAL; METALS; BIOREMEDIATION; CONTAMINATION AB The reduction of Cr(VI), Fe(III), and U(VI) was studied using three recently isolated environmental Cellulomonas sp. (WS01, WS18, and ES5) and a known Cellulomonas strain (Cellulomonas flavigena ATCC 482) under anaerobic, non-growth conditions. In all cases, these cultures were observed to reduce Cr(VI), Fe(III), and U(VI). In 100 h, with lactate as electron donor, the Cellulomonas isolates (500 mg/l total cell protein) reduced nitrilotriacetic acid chelated Fe(III) [Fe(III)-NTA] from 5 mM to less than 2.2 mM, Cr(VI) from 0.2 mM to less than 0.001 mM, and U(VI) from 0.2 mM to less than 0.12 mM. All Cellulomonas isolates also reduced Cr(VI), Fe(III), and U(VI) in the absence of lactate, while no metal reduction was observed in either the cell-free or heat-killed cell controls. This is the first report of Cellulomonas sp. reducing Fe(III) and U(VI). Further, this is the first report of Cellulomonas spp. coupling the oxidation of lactate, or other unknown electron donors in the absence of lactate, to the reduction of Cr(VI), Fe(III), and U(VI). C1 Washington State Univ, Ctr Multiphase Environm Res, Pullman, WA 99164 USA. Washington State Univ, Dept Chem Engn, Pullman, WA 99164 USA. Idaho Natl Engn & Enivornm Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. RP Peyton, BM (reprint author), Washington State Univ, Ctr Multiphase Environm Res, POB 642719, Pullman, WA 99164 USA. RI Petersen, James/B-8924-2008; Peyton, Brent/G-5247-2015 OI Peyton, Brent/0000-0003-0033-0651 NR 57 TC 73 Z9 76 U1 1 U2 14 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0175-7598 J9 APPL MICROBIOL BIOT JI Appl. Microbiol. Biotechnol. PD OCT PY 2002 VL 60 IS 1-2 BP 192 EP 199 DI 10.1007/s00253-002-1069-6 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 620ZX UT WOS:000179565000026 PM 12382063 ER PT J AU Kozheurov, VP Zalyapin, VI Shagina, NB Tokareva, EE Degteva, MO Tolstykh, EI Anspaugh, LR Napier, BA AF Kozheurov, VP Zalyapin, VI Shagina, NB Tokareva, EE Degteva, MO Tolstykh, EI Anspaugh, LR Napier, BA TI Evaluation of uncertainties in Sr-90-body-burdens obtained by whole-body count: application of Bayes' rule to derive detection limits by analysis of a posteriori data SO APPLIED RADIATION AND ISOTOPES LA English DT Article DE strontium-90; Bayes' rule; whole body counter; dose reconstruction ID RIVER DOSIMETRY SYSTEM; TECHA RIVER; RECONSTRUCTION; POPULATION; PHANTOM AB A whole body counter (WBC) designed to measure bremsstrahlung from Y-90, the short-lived daughter of Sr-90, has been used since 1974 to measure Sr-90-body burdens in residents along the Techa River, which was contaminated by releases from the Mayak Production Association. Bayes' rule has been applied to the a posteriori WBC data in order to derive the uncertainties associated with the data: The lower limit of reliable detection is 2.0 kBq and the uncertainty of routine measurements is 1.6 kBq. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Urals Res Ctr Radiat Med, Chelyabinsk 454076, Russia. So Urals State Univ, Chelyabinsk 454080, Russia. Univ Utah, Dept Radiol, Div Radiobiol, Salt Lake City, UT 84108 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Shagina, NB (reprint author), Urals Res Ctr Radiat Med, Chelyabinsk 454076, Russia. NR 18 TC 14 Z9 16 U1 0 U2 1 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 OCT PY 2002 VL 57 IS 4 BP 525 EP 535 AR PII S0969-8043(02)00129-X DI 10.1016/S0969-8043(02)00129-X PG 11 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 598DU UT WOS:000178260800011 PM 12361332 ER PT J AU Lord, CG Gaines, KF Boring, CS Brisbin, LL Gochfeld, M Burger, J AF Lord, CG Gaines, KF Boring, CS Brisbin, LL Gochfeld, M Burger, J TI Raccoon (Procyon lotor) as a bioindicator of mercury contamination at the US Department of Energy's Savannah River Site SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID SOUTHEASTERN UNITED-STATES; METHYL MERCURY; FISH AB Raccoons (n = 95) were collected from the U.S. Department of Energy's Savannah River Site (SRS) and from public hunting areas. Raccoons were collected near a stream drainage system (Steel Creek delta) and a former reactor-cooling reservoir (pond 13) that received inputs of mercury-contaminated Savannah River water. Mercury concentrations were determined for hair, liver, kidney, muscle, and spleen tissues. Samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS) and cold vapor atomic absorption spectroscopy (CVAAS). Raccoons were also collected from a natural stream floodplain system (Upper Three Runs/Tinker Creek) located upstream of Hg use and storage areas and near coal ash basins. These samples were compared to samples collected from off-site hunting areas near the SRS. Hg concentrations between internal tissues were significantly correlated. Hair did not correlate well with internal tissue and was a weak indicator of raccoon exposure to Hg. Nonetheless, raccoons are potentially good indicators of Hg contamination because tissue concentrations were higher in raccoons from areas with known Hg input than in those from reference areas, and muscle biopsies can be used as biomarkers for contaminant exposure. Muscle Hg concentrations ranged from 0-0.14 ppm from nearby hunting grounds, indicating that people hunting in designated areas near the SRS are at negligible risk for Hg consumption from raccoon meat. Several raccoons collected from the SRS had muscle Hg concentrations at or near the FDA action level for seizing commercial fish due to mercury contamination of 1.0 ppm. Though Hg action levels for wild game have not been proposed, it is clear that some SRS raccoons had Hg levels that warrant concern if these areas would be open to public hunting. Last, 64 raccoons from this study had Hg concentrations that were considered elevated by the U.S. FWS standard (> 1.1 ppm) of ecosystem health for one or two tissues (hair, liver, or kidney), and 17 had high concentrations for most or all tissues. C1 Consortium Risk Evaluat Stakeholder Participat, Environm & Occupat Hlth Sci Inst, Piscataway, NJ 08854 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Piscataway, NJ 08854 USA. Rutgers State Univ, Div Life Sci, Piscataway, NJ 08854 USA. RP Lord, CG (reprint author), Consortium Risk Evaluat Stakeholder Participat, Environm & Occupat Hlth Sci Inst, Piscataway, NJ 08854 USA. NR 37 TC 16 Z9 17 U1 1 U2 11 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD OCT PY 2002 VL 43 IS 3 BP 356 EP 363 DI 10.1007/s00244-002-1227-y PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 591GR UT WOS:000177871800015 PM 12202933 ER PT J AU Brotherton, MS Ly, C Wills, BJ Laurent-Muehleisen, SA van Breugel, W Antonucci, RRJ AF Brotherton, MS Ly, C Wills, BJ Laurent-Muehleisen, SA van Breugel, W Antonucci, RRJ TI Multiband VLA observations of the faint radio core of 3CR 68.1 SO ASTRONOMICAL JOURNAL LA English DT Article DE quasars : general; quasars : individual (3CR 68.1); radio continuum ID ACTIVE GALACTIC NUCLEI; FREE-FREE ABSORPTION; QUASARS; EMISSION; GALAXIES AB The large, powerful Fanaro-Riley class II radio source 3CR 68.1 is an optically red quasar with strong evidence of dust reddening, intrinsic ultraviolet line absorption, and X-ray absorption. In the context of its large, extended radio structure and the evidence for intrinsic material along the line of sight, it is a good candidate for a quasar seen through the edge of an obscuring torus, as proposed by unified schemes. The compact radio core coincident with the optical position of the quasar is extremely weak compared with the very bright and luminous radio lobes, suggesting that the radio core might also suffer absorption. We observed 3CR 68.1 at six frequencies and show that the radio core has a at spectrum with no evidence of free-free absorption or other strong absorption mechanisms. This result helps establish an empirical intrinsic lower range for core-to-lobe radio flux in the most powerful radio sources. C1 Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Texas, McDonald Observ, Austin, TX 78712 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Brotherton, MS (reprint author), Univ Wyoming, Dept Phys & Astron, POB 3905, Laramie, WY 82071 USA. NR 16 TC 0 Z9 0 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2002 VL 124 IS 4 BP 1943 EP 1947 DI 10.1086/342450 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 596BF UT WOS:000178143400007 ER PT J AU Keller, SC Bessell, MS Cook, KH Geha, M Syphers, D AF Keller, SC Bessell, MS Cook, KH Geha, M Syphers, D TI Blue variable stars from the MACHO database. I. Photometry and spectroscopy of the Large Magellanic Cloud sample SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (Large Magellanic Cloud); stars : emission-line, Be; stars : variables : other ID HERBIG AE/BE STARS; CALIBRATION; VARIABILITY; CONFINEMENT; LMC AB We present the photometric properties of 1279 blue variable stars within the Large Megallanic Cloud. Photometry is derived from the MACHO database. The light curves of the sample exhibit a variety of quasi-periodic and aperiodic outburst behavior. A characteristic feature of the photometric variation is that the objects are reddest when at maximum outburst. A subset of 102 objects were examined spectroscopically. Within this subset, 91% exhibited Balmer emission in at least one epoch, in some cases with spectacular spectral variability. The variability observed in the sample is consistent with the establishment and maintenance of the Be phenomenon. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. RP Keller, SC (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, 7000 E Ave, Livermore, CA 94550 USA. NR 21 TC 36 Z9 36 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2002 VL 124 IS 4 BP 2039 EP 2044 DI 10.1086/342548 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 596BF UT WOS:000178143400016 ER PT J AU Andersson, BG Idzi, R Uomoto, A Wannier, PG Chen, B Jorgensen, AM AF Andersson, BG Idzi, R Uomoto, A Wannier, PG Chen, B Jorgensen, AM TI A spectroscopic and photometric survey of stars in the field of L1457: A new distance determination SO ASTRONOMICAL JOURNAL LA English DT Article DE ISM : individual (L1457) ID MOLECULAR CLOUD MBM-12; INTERSTELLAR-MEDIUM; EXTINCTION; VICINITY; PERSEUS; TAURUS AB We present a spectroscopic and photometric survey of a sample of field stars in the region of the molecular cloud L1457. High-quality coude feed spectra, together with five-band photometry in the Sloan Digital Sky Survey system and near-infrared archival data from the Two Micron All Sky Survey, are used to derive color excesses and distances for the stars. Based on these data, a new distance estimate of 360 +/- 30 pc is derived for the cloud, supporting recent results by K. L. Luhman. The data further indicate that the north-south velocity gradient seen in the millimeter-wave CO data is mirrored in a distance gradient, with the northern part of the cloud being closer to us. A second, less opaque, layer of extinction is detected at similar to80 pc. This distance is consistent with the earlier distance estimates to the cloud, based on Na I absorption. We identify this layer with the wall of the hot Local Bubble. Hence, the dense cloud is not, as previously thought, associated with the Local Bubble. C1 Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Andersson, BG (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, 3400 N Charles St, Baltimore, MD 21218 USA. NR 29 TC 23 Z9 23 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2002 VL 124 IS 4 BP 2164 EP 2177 DI 10.1086/342541 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 596BF UT WOS:000178143400027 ER PT J AU Goobar, A Mortsell, E Amanullah, R Nugent, P AF Goobar, A Mortsell, E Amanullah, R Nugent, P TI Cosmological parameters from lensed supernovae SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gravitational lensing; cosmology : cosmological parameters ID GRAVITATIONAL LENSES; CONSTANT; STATISTICS; REDSHIFT; GALAXIES; DISTRIBUTIONS; SEPARATIONS; EXTINCTION; UNIVERSE AB We investigate the possibility of measuring the Hubble constant, the fractional energy density components and the equation of state parameter of the "dark energy" using lensed multiple images of high-redshift supernovae. With future instruments, such as the SNAP and NGST satellites, it will become possible to observe several hundred lensed core-collapse supernovae with multiple images. Accurate measurements of the image separation, flux-ratio, time-delay and lensing foreground galaxy will provide complementary information to the cosmological tests based on, e.g., the magnitude-redshift relation of type Ia supernovae, especially with regards to the Hubble parameter that could be measured with a statistical uncertainty at the one percent level. Assuming a flat universe, the statistical uncertainty on the mass density is found to be sigma(OmegaM)(stat) less than or similar to 0.05. However, systematic effects from the uncertainty of the lens modeling are likely to dominate. E.g., if the lensing galaxies are extremely compact but are (erroneously) modeled as singular isothermal spheres, the mass density is biased by sigma(OmegaM)(syst) similar to 0.1. We argue that wide-field near-IR instruments such as the one proposed for the SNAP mission are critical for collecting large statistics of lensed supernovae. C1 SCFAB, Dept Phys, S-10691 Stockholm, Sweden. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Goobar, A (reprint author), SCFAB, Dept Phys, S-10691 Stockholm, Sweden. NR 35 TC 29 Z9 29 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2002 VL 393 IS 1 BP 25 EP 32 DI 10.1051/0004-6361:20020987 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 596YC UT WOS:000178193200008 ER PT J AU Ceron, JMC Castro-Tirado, AJ Gorosabel, J Hjorth, J Fynbo, JU Jensen, BL Pedersen, H Andersen, MI Lopez-Corredoira, M Suarez, O Grosdidier, Y Casares, J Perez-Ramirez, DP Milvang-Jensen, B Mallen-Ornelas, G Fruchter, A Greiner, J Pian, E Vreeswijk, PM Barthelmy, SD Cline, T Frontera, F Kaper, L Klose, S Kouveliotou, C Hartmann, DH Hurley, K Masetti, N Mazets, E Palazzi, E Park, HS Rol, E Salamanca, I Tanvir, N Trombka, JI Wijers, RAMJ Williams, GG van den Heuvel, E AF Ceron, JMC Castro-Tirado, AJ Gorosabel, J Hjorth, J Fynbo, JU Jensen, BL Pedersen, H Andersen, MI Lopez-Corredoira, M Suarez, O Grosdidier, Y Casares, J Perez-Ramirez, DP Milvang-Jensen, B Mallen-Ornelas, G Fruchter, A Greiner, J Pian, E Vreeswijk, PM Barthelmy, SD Cline, T Frontera, F Kaper, L Klose, S Kouveliotou, C Hartmann, DH Hurley, K Masetti, N Mazets, E Palazzi, E Park, HS Rol, E Salamanca, I Tanvir, N Trombka, JI Wijers, RAMJ Williams, GG van den Heuvel, E TI The bright optical afterglow of the long GRB 001007 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; techniques : photometric; cosmology : observations ID GAMMA-RAY BURSTS; LIGHT CURVES AB We present optical follow up observations of the long GRB 001007 between 6.14 hours and similar to468 days after the event. An unusually bright optical afterglow (OA) was seen to decline following a steep power law decay with index alpha = -2.03 +/- 0.11, possibly indicating a break in the light curve at t - t(0) < 3.5 days, as found in other bursts. Upper limits imposed by the LOTIS alerting system 6.14 hours after the gamma ray event provide tentative (1.2σ) evidence for a break in the optical light curve. The spectral index β of the OA yields -1.24 +/- 0.57. These values may be explained both by several fireball jet models and by the cannonball model. Fireball spherical expansion models are not favoured. Late epoch deep imaging revealed the presence of a complex host galaxy system, composed of at least two objects located 1.2" (1.7σ) and 1.9" (2.7σ) from the afterglow position. C1 Real Inst, Cadiz 11110, Spain. Observ Armada, Secc Astron, Cadiz 11110, Spain. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. Danish Space Res Inst, DK-2100 Copenhagen O, Denmark. INTA, Lab Astrofis Espacial & Fis Fundamental, Madrid 28080, Spain. Univ Copenhagen, Astron Observ, DK-2100 Copenhagen O, Denmark. European So Observ, D-85748 Garching, Germany. Univ Oulu, Div Astron, Oulu 90014, Finland. Inst Astrofis Canarias, Tenerife 38200, Spain. Univ de la Coruna, Dept Ciencias Nevegac & Tierra, La Coruna 15011, Spain. Michigan Technol Univ, Dept Phys, Houghton, MI 49931 USA. Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. Univ Toronto, Dept Astron, Toronto, ON M5S 3H8, Canada. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Inst Astrophys, D-14482 Potsdam, Germany. Osserv Astron Trieste, I-34131 Trieste, Italy. Univ Amsterdam, NL-1098 SJ Amsterdam, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CNR, Ist Astrofis Spaziale & Fis Cosm, Sez Bologna, I-40129 Bologna, Italy. Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Clemson Univ, Clemson, SC 29634 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Hertfordshire, Dept Phys Sci, Hatfield AL10 9AB, Herts, England. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Ceron, JMC (reprint author), Real Inst, Cadiz 11110, Spain. RI Barthelmy, Scott/D-2943-2012; Hjorth, Jens/M-5787-2014; Jensen, Brian Lindgren/E-1275-2015; Palazzi, Eliana/N-4746-2015; OI Hjorth, Jens/0000-0002-4571-2306; Jensen, Brian Lindgren/0000-0002-0906-9771; Wijers, Ralph/0000-0002-3101-1808; Palazzi, Eliana/0000-0002-8691-7666; Castro-Tirado, A. J./0000-0003-2999-3563; Masetti, Nicola/0000-0001-9487-7740; Pian, Elena/0000-0001-8646-4858 NR 27 TC 6 Z9 6 U1 1 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2002 VL 393 IS 2 BP 445 EP 451 DI 10.1051/0004-6361:20021010 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 597YB UT WOS:000178247400011 ER PT J AU Kehoe, R Akerlof, C Balsano, R Bloch, J Casperson, D Fletcher, S Gisler, G Lee, B Marshall, S McKay, T Rykoff, E Smith, D Vestrand, T Wren, J AF Kehoe, R Akerlof, C Balsano, R Bloch, J Casperson, D Fletcher, S Gisler, G Lee, B Marshall, S McKay, T Rykoff, E Smith, D Vestrand, T Wren, J TI An untriggered search for optical bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; gamma rays : observations; ISM : jets and outflows; methods : data analysis; stars : variables : other ID GAMMA-RAY BURSTS; FOLLOW-UP; AFTERGLOW AB We present an untriggered search for optical bursts with the Robotic Optical Transient Search Experiment (ROTSE-I) telephoto array. Observations were taken that monitor an effective 256 deg(2) field continuously over 125 hr to m(ROTSE) = 15.7. The uniquely large field, moderate limiting magnitude, and fast cadence of 10 minutes permit transient searches in a new region of sensitivity. Our search reveals no candidate events. To quantify this result, we simulate potential optical bursts with peak magnitude m(p) at t = 10 s, which fade as f = (t/t(0))(alphat), where alpha(t) < 0. Simple estimates based on observational evidence indicate that a search of this sensitivity begins to probe the possible region occupied by gamma-ray burst ( GRB) orphan afterglows. Our observing protocol and image sensitivity result in a broad region of high detection efficiency for light curves to the bright and slowly varying side of a boundary running from [alpha(t), m(p)] = [-2.0, 6.0] to [-0.3, 13.2]. Within this region, the integrated rate of brief optical bursts is less than 1.1 x10(-8) s(-1) deg(-2). At similar to 22 times the observed GRB rate from BATSE, this suggests a limit on theta(opt)/theta(gamma)less than or similar to 5, where theta(opt) and theta(gamma) are the optical and gamma-ray collimation angles, respectively. Several effects might explain the absence of optical bursts, and a search of the kind described here but more sensitive by about 4 mag should offer a more definitive probe. C1 Univ Michigan, Dept Phys, Randall Lab, Ann Arbor, MI 48109 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Los Alamos Natl Lab, Div NIS2, Los Alamos, NM 87545 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Lawrence Livermore Natl Lab, IGPP Div, Livermore, CA 94550 USA. RP Kehoe, R (reprint author), Univ Michigan, Dept Phys, Randall Lab, 500 E Univ, Ann Arbor, MI 48109 USA. RI McKay, Timothy/C-1501-2009 OI McKay, Timothy/0000-0001-9036-6150 NR 24 TC 9 Z9 9 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2002 VL 577 IS 2 BP 845 EP 852 DI 10.1086/342231 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 598WT UT WOS:000178300000024 ER PT J AU Stanford, SA Eisenhardt, PR Dickinson, M Holden, BP De Propris, R AF Stanford, SA Eisenhardt, PR Dickinson, M Holden, BP De Propris, R TI Optical and near-infrared photometry of distant galaxy clusters SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : clusters : general; galaxies : evolution; galaxies : formation; galaxies : high-redshift; galaxies : photometry ID HUBBLE-SPACE-TELESCOPE; HIGH-REDSHIFT CLUSTERS; MEDIUM-SENSITIVITY SURVEY; COLOR-MAGNITUDE RELATION; X-RAY DATA; LUMINOSITY EVOLUTION; POPULATIONS; MORPHOLOGY; Z=1.27; Z=0.83 AB We present optical and near-infrared photometry of 45 clusters of galaxies at 0.1 < z < 1.3. Galaxy catalogs in each cluster were defined at the longest wavelength available, generally the K band, down to approximately 2 mag below M*. We include finding chart images of the band used for catalog definition. The photometry has been used in previously published papers to examine the origin and evolution of galaxies in distant clusters. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. RP Stanford, SA (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. NR 39 TC 37 Z9 38 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 2002 VL 142 IS 2 BP 153 EP 160 DI 10.1086/340972 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 596YM UT WOS:000178194100001 ER PT J AU Creim, JA Lovely, RH Miller, DL Anderson, LE AF Creim, JA Lovely, RH Miller, DL Anderson, LE TI Rats can discriminate illuminance, but not magnetic fields, as a stimulus for learning a two-choice discrimination SO BIOELECTROMAGNETICS LA English DT Article DE 60 Hz magnetic fields; static magnetic fields; illuminance; discrimination learning ID BEHAVIORAL SENSITIVITY; EXPOSURE; PERFORMANCE; MEMORY; MICE AB In each of the two experiments, nine rats were trained for 64 trials (eight trials per day) to determine if they could acquire a two-choice discrimination based on a specified discriminative stimulus (S-D). In one experiment, the S-D was a change in ambient illumination, while in the second experiment the S-D was a change in the combination of sinusoidal 60 Hz and static magnetic field (MF) and any cues attendant to energizing the coils that produced the MF exposure. The rats that had a change in illuminance as the S-D learned the two-choice task easily, P < .001, whereas the rats having a change in MFs as the S-D did not. Bioelectromagnetics 23:545-549, 2002. (C) 2002 Wiley-Liss, Inc. C1 Pacific NW Natl Lab, Bioelectromagnet Grp, Dept Biol Mol, Richland, WA 99352 USA. Univ Michigan, Med Ctr, Dept Radiol, Ann Arbor, MI 48109 USA. RP Anderson, LE (reprint author), Pacific NW Natl Lab, Bioelectromagnet Grp, Dept Biol Mol, POB 999, Richland, WA 99352 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0197-8462 J9 BIOELECTROMAGNETICS JI Bioelectromagnetics PD OCT PY 2002 VL 23 IS 7 BP 545 EP 549 DI 10.1002/bem.10052 PG 5 WC Biology; Biophysics SC Life Sciences & Biomedicine - Other Topics; Biophysics GA 597LC UT WOS:000178222200009 PM 12224059 ER PT J AU Ellrott, K Yang, CH Sladek, FM Jiang, T AF Ellrott, K Yang, CH Sladek, FM Jiang, T TI Identifying transcription factor binding sites through Markov chain optimization SO BIOINFORMATICS LA English DT Article; Proceedings Paper CT European Conference on Computational Biology (ECCB 2002) CY OCT 06-09, 2002 CL SAARBRUCKEN, GERMANY ID HEPATOCYTE NUCLEAR FACTOR; FACTOR 4-ALPHA; B GENE; EXPRESSION; PROMOTER; RECEPTOR; DNA; INVOLVEMENT; REPRESSION; PREDICTION AB Even though every cell in an organism contains the same genetic material, each cell does not express the same cohort of genes. Therefore, one of the major problems facing genomic research today is to determine not only which genes are differentially expressed and under what conditions, but also how the expression of those genes is regulated. The first step in determining differential gene expression is the binding of sequence-specific DNA binding proteins (i.e. transcription factors) to regulatory regions of the genes (i.e. promoters and enhancers). An important aspect to understanding how a given transcription factor functions is to know the entire gamut of binding sites and subsequently potential target genes that the factor may bind/regulate. In this study, we have developed a computer algorithm to scan genomic databases for transcription factor binding sites, based on a novel Markov chain optimization method, and used it to scan the human genome for sites that bind to hepatocyte nuclear factor 4 alpha (HNF4alpha). A list of 71 known HNF4alpha binding sites from the literature were used to train our Markov chain model. By looking at the window of 600 nucleotides around the transcription start site of each confirmed gene on the human genome, we identified 849 sites with varying binding potential and experimentally tested 109 of those sites for binding to HNF4alpha. Our results show that the program was very successful in identifying 77 new HNF4alpha binding sites with varying binding affinities (i.e. a 71% success rate). Therefore, this computational method for searching genomic databases for potential transcription factor binding sites is a powerful tool for investigating mechanisms of differential gene regulation. C1 Univ Calif Riverside, Dept Comp Sci, Riverside, CA 92521 USA. Univ Calif Riverside, Genet Bioinformat Program, Riverside, CA 92521 USA. Univ Calif Riverside, Dept Cell Biol & Neurosci, Riverside, CA 92521 USA. Oak Ridge Natl Lab, Div Life Sci, Prot Informat Grp, Oak Ridge, TN 37831 USA. RP Ellrott, K (reprint author), Univ Calif Riverside, Dept Comp Sci, Riverside, CA 92521 USA. EM jiang@cs.ucr.edu OI Ellrott, Kyle/0000-0002-6573-5900 FU NIDDK NIH HHS [DK53892] NR 34 TC 48 Z9 52 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 OCT PY 2002 VL 18 SU S BP S100 EP S109 PG 10 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 608GC UT WOS:000178836800016 PM 12385991 ER PT J AU Silver, RB Bartman, M AF Silver, RB Bartman, M TI A metronome-like control of the calcium signal leading to nuclear envelope breakdown and mitosis in sand dollar (Echinaracnius parma) cells SO BIOLOGICAL BULLETIN LA English DT Article; Proceedings Paper CT General Scientific Meeting of the Marine-Biological-Laboratory CY AUG 12-14, 2002 CL WOODS HOLE, MA SP Marine Biol Lab ID PHOSPHOLIPASE A(2); MICRODOMAINS; PHOSPHOFRUCTOKINASE; ASSOCIATION; MEMBRANES; DIVISION; EMBRYOS; ENZYME; QEDS; ATP C1 Wayne State Univ, Sch Med, Coll Engn, Dept Biomed Engn,Dept Pharmacol, Detroit, MI 48202 USA. Wayne State Univ, Sch Med, Coll Engn, Dept Biomed Engn,Dept Physiol, Detroit, MI 48202 USA. Wayne State Univ, Sch Med, Coll Engn, Dept Biomed Engn,Dept Radiol, Detroit, MI 48202 USA. Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA. Marine Biol Lab, Woods Hole, MA 02543 USA. RP Wayne State Univ, Sch Med, Coll Engn, Dept Biomed Engn,Dept Pharmacol, Detroit, MI 48202 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU MARINE BIOLOGICAL LABORATORY PI WOODS HOLE PA 7 MBL ST, WOODS HOLE, MA 02543 USA SN 0006-3185 EI 1939-8697 J9 BIOL BULL-US JI Biol. Bull. PD OCT PY 2002 VL 203 IS 2 BP 213 EP 215 DI 10.2307/1543403 PG 3 WC Biology; Marine & Freshwater Biology SC Life Sciences & Biomedicine - Other Topics; Marine & Freshwater Biology GA 613AQ UT WOS:000179108500023 PM 12414584 ER PT J AU Chou, CF Tegenfeldt, JO Bakajin, O Chan, SS Cox, EC Darnton, N Duke, T Austin, RH AF Chou, CF Tegenfeldt, JO Bakajin, O Chan, SS Cox, EC Darnton, N Duke, T Austin, RH TI Electrodeless dielectrophoresis of single- and double-stranded DNA SO BIOPHYSICAL JOURNAL LA English DT Article ID COLLOIDAL PARTICLES; CELLS; SEPARATION; ELECTROPHORESIS; MOLECULES; FIELDS AB Dielectrophoretic trapping of molecules is typically carried out using metal electrodes to provide high field gradients. In this paper we demonstrate dielectrophoretic trapping using insulating constrictions at far lower frequencies than are feasible with metallic trapping structures because of water electrolysis. We demonstrate that electrodeless dielectrophoresis (EDEP) can be used for concentration and patterning of both single-strand and double-strand DNA. A possible mechanism for DNA polarization in ionic solution is discussed based on the frequency, viscosity, and field dependence of the observed trapping force. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Princeton Univ, Dept Mol Biol, Princeton, NJ 08544 USA. Lawrence Livermore Natl Lab, Biosecur Support Lab, Livermore, CA USA. Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. RP Austin, RH (reprint author), Princeton Univ, Dept Phys, Jadwin Hall, Princeton, NJ 08544 USA. RI Bakajin, Olgica/A-9745-2008; Tegenfeldt, Jonas/B-9506-2008; Chou, Chia-Fu/H-4084-2013 OI Tegenfeldt, Jonas/0000-0002-3695-6886; Chou, Chia-Fu/0000-0003-0070-5556 FU NHGRI NIH HHS [HG01506]; NIGMS NIH HHS [GM55453] NR 28 TC 275 Z9 277 U1 5 U2 56 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 2002 VL 83 IS 4 BP 2170 EP 2179 PG 10 WC Biophysics SC Biophysics GA 603RA UT WOS:000178572500038 PM 12324434 ER PT J AU Walton, J AF Walton, J TI Coming clean with plant disease suppression SO BIOSCIENCE LA English DT Editorial Material C1 Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. RP Walton, J (reprint author), Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD OCT PY 2002 VL 52 IS 10 BP 873 EP 874 DI 10.1641/0006-3568(2002)052[0873:CCWPDS]2.0.CO;2 PG 2 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 603RJ UT WOS:000178573400006 ER PT J AU Rodriguez, M Sanders, CA Greenbaum, E AF Rodriguez, M Sanders, CA Greenbaum, E TI Biosensors for rapid monitoring of primary-source drinking water using naturally occurring photosynthesis SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE biosensor; fluorescence; drinking water; chemical warfare; photosynthesis; pesticides; DCMU; methyl parathion; potassium cyanide; paraquat; freshwater ID CHEMICAL WARFARE AGENTS; SOLID-PHASE MICROEXTRACTION; CHLOROPHYLL FLUORESCENCE; NERVE AGENTS; ORGANOPHOSPHATE; HERBICIDES; PESTICIDES; SAMPLES AB Working with primary-source freshwater drinking samples from the Clinch and Tennessee Rivers, we have developed a tissue-based biosensor detection system that uses naturally occurring aquatic photosynthetic tissue as the sensing material for detection of chemical antagonists in the water. Sensor readout is based on well-known principles of fluorescence induction by living photosynthetic tissue. The Clinch River is the main source of drinking water for Oak Ridge, Tennessee, while the Tennessee River is a major source for the city of Knoxville. We have successfully detected algae in every sample that we examined and readily monitored changes in the characteristic fluorescence induction curves when the samples were exposed to potassium cyanide (KCN), methyl parathion (MPt), N'(3,4-dichlorophenyl)-N,N-dimethylurea (DCMU), and paraquat. The percentage decreases in photochemical yields observed in Tennessee River samples after a 24-min exposure to KCN, MPt, and DCMU were, respectively, 21.89+/-0.76, 3.28+/-0.18, and 14.77+/-1.81. For a site at the Clinch River, the percentage decreases were 22.78+/-1.63, 8.32+/-0.21, and 17.71+/-1.32 (Table 1). The unique aspect of this approach to real-time water quality monitoring is that unlike conventional sensing devices, this sensor material is external to the detecting instrument and is continuously refreshed. These biosensors may be used as continuous rapid-warning sentinels for detection of chemical warfare agents in sunlight-exposed drinking water supplies. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. Univ Tennessee, Grad Sch Genome Sci & Technol, Knoxville, TN 37996 USA. RP Greenbaum, E (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. NR 25 TC 40 Z9 42 U1 0 U2 34 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD OCT PY 2002 VL 17 IS 10 BP 843 EP 849 AR PII S0956-5663(02)00059-3 DI 10.1016/S0956-5663(02)00059-3 PG 7 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 598GH UT WOS:000178267200002 PM 12243902 ER PT J AU Toh, CH Samis, J Downey, C Walker, J Becker, L Brufatto, N Tejidor, L Jones, G Houdijk, W Giles, A Koschinsky, M Ticknor, LO Paton, R Wenstone, R Nesheim, M AF Toh, CH Samis, J Downey, C Walker, J Becker, L Brufatto, N Tejidor, L Jones, G Houdijk, W Giles, A Koschinsky, M Ticknor, LO Paton, R Wenstone, R Nesheim, M TI Biphasic transmittance waveform in the APTT coagulation assay is due to the formation of a Ca++-dependent complex of C-reactive protein with very-low-density lipoprotein and is a novel marker of impending disseminated intravascular coagulation SO BLOOD LA English DT Article ID AMYLOID-P COMPONENT; ACUTE-PHASE PROTEINS; APOLIPOPROTEIN B-100; A-PROTEIN; PROTHROMBINASE; INFLAMMATION; ASSOCIATION; PENTRAXINS; SEQUENCE; DISEASE AB A decrease In light transmittance before clot formation, manifesting as a biphasic waveform (BPW) pattern In coagulation assays, was previously correlated with the onset of disseminated Intravascular coagulation (DIC), In this study of 1187 consecutive admissions to the Intensive care unit, the degree of this change on admission predicts DIC better than D-dimer measurements. Additionally, the BPW preceded the time of DIC diagnosis by IS hours, on average, In 56% (203 of 362) of DIC patients. The BPW is due to the rapid formation of a precipitate and coincident turbidity change on recalcification of plasma. The Isolated precipitate contains very-low-density lipoprotein (VLDL) and C-reactive protein (CRP). The addition of CRIP and Ca++ to normal plasma also causes the precipitation of VLDL and IDL, but not LDL or HDL. The K-d of the CRP/VLDL Interaction Is 340 nM, and the IC50 for Ca++ is 5.0 mM. In 15 plasmas with the BPW, CRP was highly elevated (77-398 mug/mL), and the concentration of isolated VLDL ranged from 0.082 to 1.32 mM (cholesterol). The turbidity change on recalcification correlates well with the calculated level of the CRP-VLDL complex. Clinically, the BPW better predicts for DIC than either CRP or triglyceride alone. The complex may have pathophysiological Implications because CRP can be detected in the VLDL fraction from sera of patients with the BPW, and the VLDL fraction has enhanced prothrombinase surface activity. The complex has been designated lipoprotein complexed C-reactive protein. (C) 2002 by The American Society of Hematology. C1 Queens Univ, Dept Biochem, Kingston, ON K7L 3N6, Canada. Queens Univ, Dept Pathol, Kingston, ON K7L 3N6, Canada. Organon Teknika, Durham, NC USA. Los Alamos Natl Lab, Stat Sci Grp, Decis Applicat Div, Los Alamos, NM 87545 USA. Univ Liverpool, Dept Hematol, Liverpool L69 3BX, Merseyside, England. Univ Liverpool, Dept Intens Care, Liverpool L69 3BX, Merseyside, England. Univ Liverpool, Dept Comp Sci, Liverpool L69 3BX, Merseyside, England. RP Nesheim, M (reprint author), Queens Univ, Dept Biochem, Botterell Hall,Room A210, Kingston, ON K7L 3N6, Canada. FU NHLBI NIH HHS [HL 46703] NR 35 TC 67 Z9 68 U1 0 U2 1 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1900 M STREET. NW SUITE 200, WASHINGTON, DC 20036 USA SN 0006-4971 J9 BLOOD JI Blood PD OCT 1 PY 2002 VL 100 IS 7 BP 2522 EP 2529 DI 10.1182/blood.V100.7.2522 PG 8 WC Hematology SC Hematology GA 598FV UT WOS:000178266000032 PM 12239165 ER PT J AU Lienkaemper, JJ Dawson, TE Personius, SF Seitz, GG Reidy, LM Schwartz, DP AF Lienkaemper, JJ Dawson, TE Personius, SF Seitz, GG Reidy, LM Schwartz, DP TI A record of large earthquakes on the southern Hayward fault for the past 500 years SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID CALIFORNIA; MAGNITUDE; SLIP AB The Hayward fault, a major branch of the right-lateral San Andreas fault system, traverses the densely populated eastern San Francisco Bay region, California. We conducted a paleoseismic investigation to better understand the Hayward fault's past earthquake behavior. The site is near the south end of Tyson's Lagoon, a sag pond formed in a right step of the fault in Fremont. Because the Hayward fault creeps at the surface, we identified paleoseismic events using features that we judge to be unique to ground ruptures or the result of strong ground motion, such as the presence of fault-scarp colluvial deposits and liquefaction. We correlate the most recent event evidence (E1) to the historical 1868 M 6.9 earthquake that caused liquefaction in the pond and recognize three additional paleoruptures since A.D. 1470 +/- 110 yr. Event ages were estimated by chronological modeling, which incorporated historical and stratigraphic information and radiocarbon and pollen data. Modeled, mean age and 95-percentile ranges of the three earlier events are A.D. 1730 (1650-1790) yr (E2), A.D. 1630 (1530-1740) yr (E3), and A.D. 1470 (1360-1580) (E4). The ages of these paleoearthquakes yield a mean recurrence of 130 +/- 40 yr. Although the mean recurrence is well determined for the period A.D. 1470-1868, individual intervals are less well determined: E1-E2, 140 + 80/ - 70 yr; E2-E3, 100 + 90/ - 100 yr; and E3-E4, 150 + 130/ - 110 yr. C1 US Geol Survey, Menlo Pk, CA 94025 USA. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Dept Geog, Berkeley, CA 94720 USA. RP US Geol Survey, 977 Menlo Pk, Menlo Pk, CA 94025 USA. EM jlienk@usgs.gov NR 27 TC 28 Z9 30 U1 0 U2 7 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 2002 VL 92 IS 7 BP 2637 EP 2658 DI 10.1785/0120000611 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 628ZW UT WOS:000180026800005 ER PT J AU Fumal, TE Weldon, RJ Biasi, GP Dawson, TE Seitz, GG Frost, WT Schwartz, DP AF Fumal, TE Weldon, RJ Biasi, GP Dawson, TE Seitz, GG Frost, WT Schwartz, DP TI Evidence for large earthquakes on the San Andreas fault at the Wrightwood, California, paleoseismic site: AD 500 to present SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LATE-GLACIAL EVENTS; SOUTHERN-CALIFORNIA; PALLETT CREEK; RECURRENCE INTERVAL; RADIOCARBON AGES; CAJON-PASS; PEAT; SLIP; PRETREATMENT; MACROFOSSILS AB We present structural and stratigraphic evidence from a paleoseismic site near Wrightwood, California, for 14 large earthquakes that occurred on the southern San Andreas fault during the past 1500 years. In a network of 38 trenches and creek-bank exposures, we have exposed a composite section of interbedded debris flow deposits and thin peat layers more than 24 m thick; fluvial deposits occur along the northern margin of the site. The site is a 150-m-wide zone of deformation bounded on the surface by a main fault zone along the northwest margin and a secondary fault zone to the southwest. Evidence for most of the 14 earthquakes occurs along structures within both zones. We identify paleoearthquake horizons using infilled fissures, scarps, multiple rupture terminations, and widespread folding and tilting of beds. Ages of stratigraphic units and earthquakes are constrained by historic data and 72 C-14 ages, mostly from samples of peat and some from plant fibers, wood, pine cones, and charcoal. Comparison of the long, well-resolved paleoseimic record at Wrightwood with records at other sites along the fault indicates that rupture lengths of past earthquakes were at least 100 kin long. Paleoseismic records at sites in the Coachella Valley suggest that each of the past five large earthquakes recorded there ruptured the fault suggest at least as far northwest as Wrightwood. Comparisons with event chronologies at Pallett Creek and sites to the northwest suggests that approximately the same part of the fault that ruptured in 1857 may also have failed in the early to mid-sixteenth century and several other times during the past 1200 years. Records at Pallett Creek and Pitman Canyon suggest that, in addition to the 14 earthquakes we documents one and possibly two other large earthquakes ruptured the part of the fault including Wrightwood since about A.D. 500. These observations and elapsed times that are significantly longer than mean recurrence intervals at Wrightwood and sites to the southeast suggest that at least the southermost 200 km of the San Andreas fault is near failure. C1 US Geol Survey, Menlo Pk, CA 94025 USA. Univ Oregon, Dept Geol Sci, Eugene, OR 97403 USA. Univ Nevada, Seismol Lab, Reno, NV 89557 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP US Geol Survey, 345 Middlefield Rd,MS 377, Menlo Pk, CA 94025 USA. NR 56 TC 66 Z9 72 U1 2 U2 3 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 2002 VL 92 IS 7 BP 2726 EP 2760 DI 10.1785/0120000608 PG 35 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 628ZW UT WOS:000180026800010 ER PT J AU Biasi, GP Weldon, RJ Fumal, TE Seitz, GG AF Biasi, GP Weldon, RJ Fumal, TE Seitz, GG TI Paleoseismic event dating and the conditional probability of large earthquakes on the southern San Andreas fault, California SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID IRREGULAR RECURRENCE; PALLETT CREEK; INTERVAL AB We introduce a quantitative approach to paleoearthquake dating and apply it to paleoseismic data from the Wrightwood and Pallett Creek sites on the southern San Andreas fault. We illustrate how stratigraphic ordering, sedimentological, and historical data can be used quantitatively in the process of estimating earthquake ages. Calibrated radiocarbon age distributions are used directly from layer dating through recurrence intervals and recurrence probability estimation. The method does not eliminate subjective judgements in event dating, but it does provide a means of systematically and objectively approaching the dating process. Date distributions for the most recent 14 events at Wrightwood are based on sample and contextual evidence in Fumal et al. (2002) and site context and slip history in Weldon et al. (2002). Pallett Creek event and dating descriptions are from published sources. For the five most recent events at Wrightwood, our results are consistent with previously published estimates, with generally comparable or narrower uncertainties. For Pallett Creek, our earthquake date estimates generally overlap with previous results but typically have broader uncertainties. Some event date estimates are very sensitive to details of data interpretation. The historical earthquake in 1857 ruptured the ground at both sites but is not constrained by radiocarbon data. Radiocarbon ages, peat accumulation rates, and historical constraints at Pallett Creek for event X yield a date estimate in the earliest 1800s and preclude a date in the late 1600s. This event is almost certainly the historical 1812 earthquake, as previously concluded by Sieh et al. (1989). This earthquake also produced ground deformation at Wrightwood. All events at Pallett Creek, except for event T, about A.D. 1360, and possibly event I, about A.D. 960, have corresponding events at Wrightwood with some overlap in age ranges. Event T falls during a period of low sedimentation at Wrightwood when conditions were not favorable for recording earthquake evidence. Previously proposed correlations of Pallett Creek X with Wrightwood W3 in the 1690s and Pallett Creek event V with W5 around 1480 (Fumal et al., 1993) appear unlikely after our dating reevaluation. Apparent internal inconsistencies among event, layer, and dating relationships around events R and V identify them as candidates for further investigation at the site. Conditional probabilities of earthquake recurrence were estimated using Poisson, lognormal, and empirical models. The presence of 12 or 13 events at Wrightwood during the same interval that 10 events are reported at Pallett Creek is reflected in mean recurrence intervals of 105 and 135 years, respectively. Average Poisson model 30-year conditional probabilities are about 20% at Pallett Creek and 25% at Wrightwood. The lognormal model conditional probabilities are somewhat higher, about 25% for Pallett Creek and 34% for Wrightwood. Lognormal variance sigma(1n) estimates of 0.76 and 0.70, respectively, imply only weak time predictability. Conditional probabilities of 29% and 46%, respectively, were estimated for an empirical distribution derived from the data alone. Conditional probability uncertainties are dominated by the brevity of the event series; dating uncertainty contributes only secondarily. Wrightwood and Pallett Creek event chronologies both suggest variations in recurrence interval with time, hinting that some form of recurrence rate modulation may be at work, but formal testing shows that neither series is more ordered than might be produced by a Poisson process. C1 Univ Nevada, Seismol Lab, Reno, NV 89557 USA. Univ Oregon, Dept Geol Sci, Eugene, OR 97403 USA. US Geol Survey, Earthquake Hazards Team, Menlo Pk, CA 94025 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Univ Nevada, Seismol Lab, MS 174, Reno, NV 89557 USA. NR 30 TC 67 Z9 67 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 2002 VL 92 IS 7 BP 2761 EP 2781 DI 10.1785/0120000605 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 628ZW UT WOS:000180026800011 ER PT J AU Fumal, TE Rymer, MJ Seitz, GG AF Fumal, TE Rymer, MJ Seitz, GG TI Timing of large earthquakes since AD 800 on the Mission Creek strand of the San Andreas fault zone at Thousand Palms Oasis, near Palm Springs, California SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOUTHERN-CALIFORNIA; COACHELLA VALLEY; SLIP; CALIBRATION; TRANSPRESSION; AREA AB Paleoseismic investigations across the Mission Creek strand of the San Andreas fault at Thousand Palms Oasis indicate that four and probably five surface-rupturing earthquakes occurred during the past 1200 years. Calendar age estimates for these earthquakes are based on a chronological model that incorporates radiocarbon dates from 18 in situ burn layers and stratigraphic ordering constraints. These five earthquakes occurred in about A.D. 825 (770-890) (mean, 95% range), A.D. 982 (840-1150), A.D. 1231 (1170-1290), A.D. 1502 (1450-1555), and after a date in the range of A.D. 1520-1680. The most recent surface-rupturing earthquake at Thousand Palms is likely the same as the A.D. 1676 +/- 35 event at Indio reported by Sieh and Williams (1990). Each of the past five earthquakes recorded on the San Andreas fault in the Coachella Valley strongly overlaps in time with an event at the Wrightwood paleoseismic site, about 120 km northwest of Thousand Palms Oasis. Correlation of events between these two sites suggests that at least the southernmost 200 km of the San Andreas fault zone may have ruptured in each earthquake. The average repeat time for surface-rupturing earthquakes on the San Andreas fault in the Coachella Valley is 215 +/- 25 years, whereas the elapsed time since the most recent event is 326 +/- 35 years. This suggests the southernmost San Andreas fault zone likely is very near failure. The Thousand Palms Oasis site is underlain by a series of six channels cut and filled since about A.D. 800 that cross the fault at high angles. A channel margin about 900 years old is offset right laterally 2.0 +/- 0.5 m, indicating a slip rate of 4 +/- 2 mm/yr. This slip rate is low relative to geodetic and other geologic slip rate estimates (26 +/- 2 mm/yr and about 23-35 nun/yr, respectively) on the southernmost San Andreas fault zone, possibly because (1) the site is located in a small step-over in the fault trace and so the rate is not be representative of the Mission Creek fault, (2) slip is partitioned northward from the San Andreas fault and into the eastern California shear zone, and/or (3) slip is partitioned onto the Banning strand of the San Andreas fault zone. C1 US Geol Survey, Menlo Pk, CA 94025 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Fumal, TE (reprint author), US Geol Survey, MS 977,345 Middlefield Rd, Menlo Pk, CA 94025 USA. NR 40 TC 39 Z9 40 U1 0 U2 6 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 2002 VL 92 IS 7 BP 2841 EP 2860 DI 10.1785/0120000609 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 628ZW UT WOS:000180026800014 ER PT J AU Mohrenweiser, HW Xi, T Vazquez-Matias, J Jones, IM AF Mohrenweiser, HW Xi, T Vazquez-Matias, J Jones, IM TI Identification of 127 amino acid substitution variants in screening 37 DNA repair genes in humans SO CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION LA English DT Article ID SINGLE-NUCLEOTIDE POLYMORPHISMS; BASE EXCISION-REPAIR; XERODERMA-PIGMENTOSUM; CANDIDATE GENES; BREAST-CANCER; SEQUENCE DIVERSITY; MISMATCH REPAIR; SUSCEPTIBILITY; DAMAGE; XRCC1 AB The repair of damaged DNA requires the function of multiple proteins in generally damage-specific, nonredundant pathways. The relationship of DNA repair to cancer susceptibility is obvious in "cancer families," in which low frequency, high penetrance, loss-of-function variant allelles of genes with roles in the repair of damaged DNA have been associated with a high risk of disease. More important for the cancer incidence in the general population, many individuals exhibit reduced (60-75% of normal) repair capacity phenotypes that have been associated with several-fold increases in individual cancer risk. In a program to identify the molecular basis for the variation in repair capacity and the elevated cancer susceptibility, we have identified 127 amino acid substitution variants in resequencing 37 DNA repair genes in 36-164 unrelated individuals. Over 50% of the substitutions are exchanges of amino acid residues with dissimilar physical or chemical properties, at sites at which the common residue is identical in the human and mouse proteins. Five additional sequence changes resulting in proteins with altered termination of translation and one amino acid insertion variant were detected. The variant allele frequencies average 0.047, with individual variant allele frequencies ranging from <0.01 to 0.43. Homozygous variant individuals and individuals with multiple amino acid substitutions in a gene were observed. Most individuals exhibited variation in multiple genes in a repair pathway. Ten variant alleles accounted for 52% of the genetic variation among individuals, but a striking 23% of the total variation is associated with 108 variants with allele frequencies of less than 5%. Screening generally healthy individuals generates a catalogue of common variants that is a resource for molecular epidemiology studies endeavoring to use a genotype to phenotype paradigm to estimate the role of genetic variation and individual susceptibility in disease risk from environmental and lifestyle exposures in the general population of the United States. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Mohrenweiser, HW (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-448,POB 0808,7000 E Ave, Livermore, CA 94550 USA. EM mohrenweiser1@llnl.gov FU NCI NIH HHS [1 U-1 CA 83180-03]; NIEHS NIH HHS [Y1-ES-8054-05] NR 64 TC 125 Z9 131 U1 1 U2 3 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 1055-9965 J9 CANCER EPIDEM BIOMAR JI Cancer Epidemiol. Biomarkers Prev. PD OCT PY 2002 VL 11 IS 10 BP 1054 EP 1064 PN 1 PG 11 WC Oncology; Public, Environmental & Occupational Health SC Oncology; Public, Environmental & Occupational Health GA 604RD UT WOS:000178634100015 PM 12376507 ER PT J AU Knize, MG Kulp, KS Felton, JS AF Knize, MG Kulp, KS Felton, JS TI The effect of dietary soy protein on the metabolism of PhIP in humans. SO CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION LA English DT Meeting Abstract CT Conference on Frontiers in Cancer Prevention Research CY OCT 14-18, 2002 CL BOSTON, MASSACHUSETTS SP Amer Assoc Canc Res C1 Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 1055-9965 J9 CANCER EPIDEM BIOMAR JI Cancer Epidemiol. Biomarkers Prev. PD OCT PY 2002 VL 11 IS 10 MA B326 BP 1189S EP 1189S PN 2 PG 1 WC Oncology; Public, Environmental & Occupational Health SC Oncology; Public, Environmental & Occupational Health GA 604RE UT WOS:000178634200192 ER PT J AU Liu, Z Li, L Iglesia, E AF Liu, Z Li, L Iglesia, E TI Catalytic pyrolysis of methane on Mo/H-ZSM5 with continuous hydrogen removal by permeation through dense oxide films SO CATALYSIS LETTERS LA English DT Article DE methane pyrolysis; membrane reactors; Mo/H-ZSM5 ID ION ZSM-5 ZEOLITES; EXCHANGED H-ZSM5; CONVERSION; BENZENE; NAPHTHALENE; MO AB A dense SrCe0.95Yb0.05O3-alpha thin film (similar to2 mum) was used to remove H-2 during non-oxidative conversion of methane to higher hydrocarbons on Mo/H-ZSM5 in order to overcome kinetic and thermodynamic constraints. At 950 K, these films removed only a small fraction of the H-2 produced and hydrocarbon synthesis rates were unaffected by H-2 removal. Higher temperatures led to a modest increase in CH4 conversion rates, but also to slightly lower C-2-C-12 hydrocarbon selectivities and to higher catalyst deactivation rates. These undesired effects were eliminated by the addition of small amounts of CO2 to the CH4 reactants. The combination of dense SrCe0.95Yb0.05O3-alpha thin films, chain-limiting catalytic pyrolysis reactions on Mo/H-ZSM5, and CO2 co-reactants led to stable catalyst performance and modestly higher hydrocarbon synthesis rates than in conventional reactors. The improvements achieved by continuous H-2 removal are in agreement with prediction of kinetic-transport model simulations in tubular reactors with permeable walls. C1 Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Iglesia, E (reprint author), Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Iglesia, Enrique/D-9551-2017 OI Iglesia, Enrique/0000-0003-4109-1001 NR 27 TC 15 Z9 15 U1 4 U2 20 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1011-372X J9 CATAL LETT JI Catal. Lett. PD OCT PY 2002 VL 82 IS 3-4 BP 175 EP 180 DI 10.1023/A:1020510810548 PG 6 WC Chemistry, Physical SC Chemistry GA 601EK UT WOS:000178433400004 ER PT J AU Chapline, G AF Chapline, G TI Entangled states, holography, and quantum surfaces SO CHAOS SOLITONS & FRACTALS LA English DT Article ID SQUEEZED-LIGHT; UNIVERSAL; COMPUTATION; SYSTEMS; MODEL AB Starting with an elementary discussion of quantum holography, we show that entangled quantum states of qubits provide a "local" representation of the global geometry and topology of quantum Riemann surfaces. This representation may play an important role in both mathematics and physics. Indeed, the simplest way to represent the fundamental objects in a "theory of everything" may be as multi-qubit entangled states. (C) 2002 Published by Elsevier Science Ltd. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Chapline, G (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 24 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD OCT PY 2002 VL 14 IS 6 BP 809 EP 816 AR PII S0960-0779(02)00025-5 DI 10.1016/S0960-0779(02)00025-5 PG 8 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 569BD UT WOS:000176578700002 ER PT J AU Blanchfield, D AF Blanchfield, D TI Objective merit review: Democracy in action SO CHEMICAL ENGINEERING PROGRESS LA English DT Article C1 US DOE, Golden Field Off, Golden, CO 80401 USA. RP Blanchfield, D (reprint author), US DOE, Golden Field Off, 1617 Cole Blvd, Golden, CO 80401 USA. NR 3 TC 0 Z9 0 U1 1 U2 3 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0360-7275 J9 CHEM ENG PROG JI Chem. Eng. Prog. PD OCT PY 2002 VL 98 IS 10 BP 68 EP 73 PG 6 WC Engineering, Chemical SC Engineering GA 604FP UT WOS:000178606200055 ER PT J AU Gauglitz, PA Friedmann, F Kam, SI Rossen, WR AF Gauglitz, PA Friedmann, F Kam, SI Rossen, WR TI Foam generation in homogeneous porous media SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE foam; porous media; packed bed; surfactant; hysteresis; foam generation ID MOBILIZATION PRESSURE-GRADIENT; FLOWING FOAMS AB In steady gas-liquid flow in homogeneous porous media with surfactant present, there is often observed a critical injection velocity or pressure gradient delp(min) at which "weak" or "coarse" foam is abruptly converted into "strong foam", with a reduction of one to two orders of magnitude in total mobility: i.e., "foam generation". Earlier research on foam generation is extended here with extensive data for a variety of porous media, permeabilities, gases (N-2 and CO2), and surfactants. For bead and sandpacks, delp(min) scales like (1/k), where k is permeability, over 2 1/2 orders of magnitude in k; for consolidated media, the relation is more complex. For dense-CO2 foam, delp(min) exists but can be less than 23 KPa/m (1 psi/ft). If pressure drop, rather than flow rates, is fixed, one observes an unstable regime between stable "strong" and "coarse" foam regimes; in the unstable regime delp is nonuniform in space or variable in time. Results are interpreted in terms of the theory of foam mobilization at a critical pressure gradient. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. ChevronTexaco Petr Technol Co, San Ramon, CA 94583 USA. Univ Adelaide, Sch Petr Engn & Management, Adelaide, SA 5005, Australia. RP Rossen, WR (reprint author), Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. NR 37 TC 67 Z9 73 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD OCT PY 2002 VL 57 IS 19 BP 4037 EP 4052 AR PII S0009-2509(02)00340-8 PG 16 WC Engineering, Chemical SC Engineering GA 608GE UT WOS:000178837100002 ER PT J AU Redington, RL Sams, RL AF Redington, RL Sams, RL TI N-2 pressure broadened Q branch spikes and vibration-contortion-rotation effects in the high resolution FTIR spectrum of tropolone SO CHEMICAL PHYSICS LA English DT Article ID JET-COOLED TROPOLONE; ELECTRONIC-SPECTRA; VAPOR; SPECTROSCOPY; EXCITATION; DYNAMICS; BAND; C2H2 AB Nitrogen pressure broadening effects are observed on the high resolution (0.0025 cm(-1)) FTIR spectrum of gaseous tropolone at 298 K and 32 m of path length. Broadening observations on narrow absorption spikes contribute to understanding of the spectroscopy and dynamics of tropolone in several ways. First, they help to establish a remarkable progression of sharp peaks near 752 cm(-1) as a part of the Q branch of the anharmonic v(22) (COH torsion) fundamental. The subband spacings of about 0.005-0.010 cm(-1) are too large to be determined by harmonic vibrational differences in the rotational constants alone and are attributed to vibration-contortion-rotation perturbations of the upper state (v(22)) energy levels of this anharmonic and relatively large amplitude vibration. Second, the isolated and sharp Q branch spikes near 915 cm(-1) allow first estimates to be made for effective composite pressure broadening coefficients of tropolone-N-2 collisions. The coefficients for transitions within the N-con = 0 and N-con = 1 contortion states differ from each other. They are relatively small due to the preponderance of high rotational states in their composition. Third N-2 broadening effects on substructure in the Q branch doublet near 754 cm(-1) help support the assignment of this doublet to tunneling structure of the v(37) fundamental (contortion or incipient skeletal tunneling). The observed doublet components appear as perturbatively IR enhanced three and five peak fragments of weak longer progressions. The parallel spectroscopic behaviors of the perturbed anharmonic v(22) and v(37) vibrations differ markedly from behavior observed for the quasiharmonic vibrations. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Redington, RL (reprint author), Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. NR 20 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD OCT 1 PY 2002 VL 283 IS 1-2 SI SI BP 135 EP 151 AR PII S0301-0104(02)00614-6 DI 10.1016/S0301-0104(02)00614-6 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 599WY UT WOS:000178359200011 ER PT J AU Cosman, M Lightstone, FC Krishnan, VV Zeller, L Prieto, MC Roe, DC Balhorn, R AF Cosman, M Lightstone, FC Krishnan, VV Zeller, L Prieto, MC Roe, DC Balhorn, R TI Identification of novel small molecules that bind to two different sites on the surface of tetanus toxin C fragment SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; LIGAND-RECEPTOR INTERACTIONS; BOTULINUM NEUROTOXIN-B; HIGH-AFFINITY LIGANDS; DIFFUSION-EDITED NMR; NEUROTRANSMITTER RELEASE; GANGLIOSIDE BINDING; MATRIX ANALYSIS; DRUG DESIGN; STD-NMR AB A combination of computational methods, electrospray ionization mass spectroscopy (ESI-MS), and NMR spectroscopy has been used to identify novel small molecules that bind to two adjacent sites on the surface of the C fragment of tetanus toxin (TetC). One of these sites, Site-1, binds gangliosides present on the surface of motor neurons, while Site-2 is a highly conserved deep cleft in the structures of the tetanus (TeNT) and botulinum (BoNT) neurotoxins. ESI-MS was used to experimentally determine which of the top 11 computationally predicted Site-2 candidates bind to TetC. Each of the six molecules that tested positive was further screened, individually and as mixtures, for binding to TetC in aqueous solutions by NMR. A trNOESY competition assay was developed that used doxorubicin as a marker for Site-1 to provide insight into whether the predicted Site-2 ligands bound to a different site. Of the six predicted Site-2 ligands tested, only four were observed to bind. Naphthofluorescein-di-beta-galactopyranoside was insoluble under conditions compatible with TetC. Sarcosine-Arg-Gly-Asp-Ser-Pro did not appear to bind, but its binding affinity may have been outside the range detectable by the trNOESY experiment. Of the remaining four, three [3-(N-maleimidopropionyl)-biocytin, lavendustin A, and Try-Glu-Try] bind in the same site, presumably the predicted Site-2. The fourth ligand, Ser-Gln-Asn-Tyr-Pro-Ile-Val, binds in a third site that differs from Site-1 or predicted Site-2. The results provide a rational, cost- and time-effective strategy for the selection of an optimal set of Site-1 binders and predicted Site-2 binders for use in synthesizing novel bidendate antidotes or detection reagents for clostridial neurotoxins, such as TeNT and BoNT. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Lumicyte Inc, Fremont, CA 94536 USA. Sandia Natl Labs, Biosyst Res Dept, Livermore, CA 94551 USA. RP Cosman, M (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RI Krishnan, Krish/A-6859-2010 NR 57 TC 13 Z9 13 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD OCT PY 2002 VL 15 IS 10 BP 1218 EP 1228 DI 10.1021/tx025570m PG 11 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 607TX UT WOS:000178807800002 PM 12387617 ER PT J AU Kuang, XJ Jing, XP Loong, CK Lachowski, EE Skakle, JMS West, AR AF Kuang, XJ Jing, XP Loong, CK Lachowski, EE Skakle, JMS West, AR TI A new hexagonal 12-layer perovskite-related structure: Ba6R2Ti4O17 (R = Nd and Y) SO CHEMISTRY OF MATERIALS LA English DT Article ID CRYSTAL-STRUCTURE; OXIDE; SYSTEM AB The crystal structure of Ba6R2Ti4O17 (R = Nd and Y) was determined by combined analysis of X-ray and neutron powder diffraction data. Both materials crystallize in hexagonal symmetry with space group P6(3)/mmc, Z = 2. The unit cell parameters at room temperature are a = 5.99283(9) Angstrom and c = 29.9289(8) Angstrom for Nd and a = 5.93055(4) Angstrom and c = 29.5239(3) Angstrom for Y. The structure can be described as stacking of cubic (c) and hexagonal (h) [BaO3] layers as well as ordered, oxygen-deficient, pseudo-cubic (c') [BaO2] layers in the sequence of (c'cchcc)(2) along the c-axis and belongs to the 12-layer hexagonal perovskite-related family. The structural framework exhibits face-sharing TiO6 octahedral layers (Ti2O9), RO6 octahedral layers, and TiO4 tetrahedral layers. The TiO4 subunits form around the c' layers. C1 Peking Univ, Coll Chem & Mol Engn, State Key Lab Rare Earth Mat Chem & Appicat, Beijing 100871, Peoples R China. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Univ Aberdeen, Dept Chem, Aberdeen AB24 3UE, Scotland. Univ Sheffield, Dept Mat Engn, Sheffield S1 3JD, S Yorkshire, England. RP Jing, XP (reprint author), Peking Univ, Coll Chem & Mol Engn, State Key Lab Rare Earth Mat Chem & Appicat, Beijing 100871, Peoples R China. RI Skakle, Jan/B-2187-2010; Kuang, Xiaojun/K-4129-2013; OI West, Anthony/0000-0002-5492-2102 NR 30 TC 15 Z9 15 U1 1 U2 10 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 OCT PY 2002 VL 14 IS 10 BP 4359 EP 4363 DI 10.1021/cm020374m PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 607GC UT WOS:000178782900053 ER PT J AU Hart, RT Anspach, MA Kraft, BJ Zaleski, JM Zwanziger, JW DeSanto, PJ Stein, B Jacob, J Thiyagarajan, P AF Hart, RT Anspach, MA Kraft, BJ Zaleski, JM Zwanziger, JW DeSanto, PJ Stein, B Jacob, J Thiyagarajan, P TI Optical implications of crystallite symmetry and structure in potassium niobate tellurite glass ceramics SO CHEMISTRY OF MATERIALS LA English DT Article ID NONLINEAR ELECTRONIC RESPONSE; BOND-ORBITAL THEORY; 2ND-HARMONIC GENERATION; K2O-NB2O5-TEO2 GLASSES; IONIC-CRYSTALS; OXIDES AB We present combined results of optical, scattering, and spectroscopic studies of (K2O)(15)(Nb2O5)(15)(TeO2)(70) glass and glass ceramic and comment on possible mechanisms of the optical behavior in terms of existing theory. The glass ceramic is confirmed to generate second-harmonic light. Combined neutron and X-ray diffraction data have been indexed to an orthorhombic unit cell (a = 3.39 Angstrom, b = 4.78 Angstrom, c= 6.38 Angstrom). Additionally, we show that the previously proposed fluorite-based model is insufficient for the crystal phase using real-space analysis. The orthorhombic unit cell allows the possibility of a conventional explanation for the second-harmonic generation (SHG). Peak broadening and scattering length difference analyses are combined to formulate a model of anion disorder in the crystal phase. TEM and SAXS reveal domains of approximate to 15 nm in both the glass and glass ceramic. The role of liquid-liquid phase separation in the crystallization behavior of this material is discussed. Solid-state Nb-93 MAS NMR and Raman spectroscopy offer insight into Te valence and polyhedral distribution as well as Nb site symmetry and chemical connectivity. The effects of these geometries and anion disorder on optical response are discussed. C1 Univ Delaware, WM Keck Electron Microscopy Facil, Spencer Lab, Newark, DE 19716 USA. Indiana Univ, Indiana Mol Biol Inst, Bloomington, IN 47405 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Zwanziger, JW (reprint author), Univ Delaware, WM Keck Electron Microscopy Facil, Spencer Lab, Newark, DE 19716 USA. OI Stein, Barry/0000-0003-2762-9434 NR 33 TC 17 Z9 17 U1 1 U2 11 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 OCT PY 2002 VL 14 IS 10 BP 4422 EP 4429 DI 10.1021/cm020615q PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 607GC UT WOS:000178782900063 ER PT J AU Kurbanov, EA Post, WM AF Kurbanov, EA Post, WM TI Changes in area and carbon in forests of the Middle Zavolgie: A regional case study of Russian forests SO CLIMATIC CHANGE LA English DT Article; Proceedings Paper CT International Conference on Role of Boreal Forests and Forestry in the Global Carbon Budget CY MAY 08-12, 2000 CL EDMONTON, CANADA SP Int Boreal Forest Res Assoc ID SEQUESTRATION; ECOSYSTEMS; STORAGE; CYCLE; POOLS AB We studied forest land-use and carbon storage over a 40-year period in the Middle Zavolgie region of Russia, an area of approximately 287,000 km(2). Data were obtained from state forest inventories for 1958 and 1995. In spite of the effects of disturbances and uncontrolled harvesting between 1958 and 1990, the forests of the Middle Zavolgie Region remained a considerable pool of ecosystem carbon (C). Over the study period the total area of forest lands decreased by approximately 2%, while the growing stock increased by 8%. There were significant changes in the age class structure of these forest ecosystems toward a larger proportion of young and middle aged stands. The total amount of carbon in the stem biomass of forests in all regions of Middle Zavolgie increased over the 40-year period and was equal to about 307 TgC in 1995. A regional approach for estimating the C dynamics of forest ecosystems in response to land use in the Middle Zavolgie region can contribute to understanding the potential role of Russian forests in C sequestration. This information is important for implementation of international conventions concerning national carbon budgets and reducing the potential negative impacts of climate change. C1 Mari State Tech Univ, Dept Forest Inventory & Measurements, Yoshkar Ola 424024, OMC, Russia. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Kurbanov, EA (reprint author), Mari State Tech Univ, Dept Forest Inventory & Measurements, Pl Lenina 3, Yoshkar Ola 424024, OMC, Russia. RI Post, Wilfred/B-8959-2012 NR 36 TC 1 Z9 5 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD OCT PY 2002 VL 55 IS 1-2 BP 157 EP 173 DI 10.1023/A:1020275713889 PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 593FJ UT WOS:000177980100009 ER PT J AU Kerstein, AR AF Kerstein, AR TI One-Dimensional Turbulence: A new approach to high-fidelity subgrid closure of turbulent flow simulations SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE turbulence; computer simulation; fluid dynamics; stochastic processes ID LARGE-EDDY SIMULATION; HOMOGENEOUS TURBULENCE; MODEL FORMULATION; PASSIVE SCALARS; SHEAR FLOWS; INTERMITTENCY; STATISTICS; TRANSPORT; ISOTROPY; FLAMES AB Consideration of the requirements for robust, high-fidelity subgrid closure of large-eddy simulations of multiphysics turbulent flows indicates the need for a spatially and temporally resolved representation of fine-scale physical and chemical processes that are coupled to fluid motion. One-Dimensional Turbulence (ODT), a potentially cost-effective approach for this purpose, captures these couplings by means of a stochastic simulation implemented on a one-dimensional domain. A subgrid implementation of ODT is formulated and its potential advantages and limitations are assessed. (C) 2002 Elsevier Science B.V All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Kerstein, AR (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 45 TC 14 Z9 15 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD OCT 1 PY 2002 VL 148 IS 1 BP 1 EP 16 AR PII S0010-4655(02)00552-0 DI 10.1016/S0010-4655(02)00552-0 PG 16 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 604FG UT WOS:000178605500001 ER PT J AU Kuhn, P Wilson, K Patch, MG Stevens, RC AF Kuhn, P Wilson, K Patch, MG Stevens, RC TI The genesis of high-throughput structure-based drug discovery using protein crystallography SO CURRENT OPINION IN CHEMICAL BIOLOGY LA English DT Review ID STRUCTURE-BASED DESIGN; ORALLY BIOAVAILABLE INHIBITOR; BIOLOGICAL EVALUATION; HIV-1 PROTEASE; BINDING MODE; SELECTIVE INHIBITORS; CRYSTAL-STRUCTURES; KINASE INHIBITORS; LEAD GENERATION; RATIONAL DESIGN AB Over the past 12 years, drugs have been developed using structure-based drug design relying upon traditional crystallographic methods. Established successes, such as the drugs designed against HIV-1 protease and neuraminidase, demonstrate the utility of a structure-based approach in the drug-discovery process. However, the approach has historically lacked throughput and reliability capabilities; these bottlenecks are being overcome by breakthroughs in high-throughput structural biology. Recent technological innovations such as submicroliter high-throughput crystallization, high-performance synchrotron beamlines and rapid binding-site analysis of de novo targets using virtual ligand screening and small molecule co-crystallization have resulted in a significant advance in structure-based drug discovery. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Syrrx Inc, San Diego, CA 92121 USA. Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Joint Ctr Struct Genom, La Jolla, CA USA. RP Kuhn, P (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 NR 73 TC 83 Z9 85 U1 2 U2 21 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1367-5931 J9 CURR OPIN CHEM BIOL JI Curr. Opin. Chem. Biol. PD OCT PY 2002 VL 6 IS 5 BP 704 EP 710 DI 10.1016/S1367-5931(02)00361-7 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 601WD UT WOS:000178470900021 PM 12413557 ER PT J AU Callender, R Dyer, RB AF Callender, R Dyer, RB TI Probing protein dynamics using temperature jump relaxation spectroscopy SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Review ID FAST EVENTS; TRIOSEPHOSPHATE ISOMERASE; LACTATE-DEHYDROGENASE; LIGAND-BINDING; LOOP MOTION; PEPTIDE AB There have been recent advances in initiating and perturbing chemical reactions on very fast timescales, as short as picoseconds, thus making it feasible to study a vast range of chemical kinetics problems that heretofore could not be studied. One such approach is the rapid heating of water solutions using laser excitation. Laser-induced temperature jump relaxation spectroscopy can be used to determine the dynamics of protein motion, an area largely unstudied for want of suitable experimental and theoretical probes, despite the obvious importance of dynamics to protein function. Coupled with suitable spectroscopic probes of structure, relaxation spectroscopy can follow the motion of protein atoms over an enormous time range, from picoseconds to minutes (or longer), and with substantial structural specificity. C1 Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Callender, R (reprint author), Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. FU NIGMS NIH HHS [GM 35183, GM 53640, P01 GM068036] NR 19 TC 61 Z9 62 U1 1 U2 14 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD OCT PY 2002 VL 12 IS 5 BP 628 EP 633 DI 10.1016/S0959-440X(02)00370-6 PG 6 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 604PP UT WOS:000178630500010 PM 12464315 ER PT J AU Dauter, Z AF Dauter, Z TI New approaches to high-throughput phasing SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Review ID PROTEIN-STRUCTURE DETERMINATION; HEAVY-ATOM DERIVATIVES; QUICK-SOAK METHOD; SOFT X-RAYS; ANOMALOUS-SCATTERING; MOLECULAR REPLACEMENT; MAXIMUM-LIKELIHOOD; S-ATOMS; MACROMOLECULAR CRYSTALLOGRAPHY; DENSITY MODIFICATION AB Recent progress in macromolecular phasing, in part stimulated by the high-throughput structural biology initiatives, has made this crucial stage of the elucidation of crystal structures easier and more automatic. A quick soak in various salts leads to the rapid incorporation of the anomalously scattering ions, suitable for phasing by MAD (multiwavelength anomalous dispersion), SAD (single-wavelength anomalous dispersion) or MIR (multiple isomorphous replacement) methods. The availability of stable synchrotron beam lines equipped with elaborate hardware control and sophisticated data processing programs makes it possible to collect very accurate diffraction data and to solve structures from the very weak anomalous signal of such atoms as sulfur or phosphorus, inherently present in macromolecules. The current progress in phasing, coupled with the parallel advances in protein crystallization, diffraction data collection and so on, suggests that, in the near future, the process of macromolecular crystal structure elucidation may become fully automatic. C1 NCI, Brookhaven Natl Lab, Synchrotron Radiat Res Sect, Upton, NY 11973 USA. RP Dauter, Z (reprint author), NCI, Brookhaven Natl Lab, Synchrotron Radiat Res Sect, Bldg 725A-X9, Upton, NY 11973 USA. EM dauter@bnl.gov NR 47 TC 35 Z9 36 U1 1 U2 5 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD OCT PY 2002 VL 12 IS 5 BP 674 EP 678 DI 10.1016/S0959-440X(02)00372-X PG 5 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 604PP UT WOS:000178630500017 PM 12464322 ER PT J AU Krtolica, A de Solorzano, CO Lockett, S Campisi, J AF Krtolica, A de Solorzano, CO Lockett, S Campisi, J TI Quantification of epithelial cells in coculture with fibroblasts by fluorescence image analysis SO CYTOMETRY LA English DT Article DE cell quantification; coculture; image analysis; epithelial-stromal interactions; cell proliferation; green fluorescent protein; 4,6-diamidino-2-phenylindole; fluorescence microscopy ID TUMOR-STROMAL INTERACTIONS; CYTOMETRY AB Background: To demonstrate that senescent fibroblasts stimulate the proliferation and neoplastic transformation of premalignant epithelial cells (Krtolica et al.: Proc Natl Acad Sci USA 98:12072-12077, 2001), we developed methods to quantify the proliferation of epithelial cells cocultured with fibroblasts. Methods: We stained epithelial-fibroblast cocultures with the fluorescent DNA-intercalating dye 4,6-diamidino2-phenyhndole (DAPI), or expressed green fluorescent protein (GFP) in the epithelial cells, and then cultured them with fibroblasts. The cocultures were photographed under an inverted microscope with appropriate filters, and the fluorescent images were captured with a digital camera. We modified an image analysis program to selectively recognize the smaller, more intensely fluorescent epithelial cell nuclei in DAPI-stained cultures and used the program to quantify areas with DAPI fluorescence generated by epithelial nuclei or GFP fluorescence generated by epithelial cells in each field. Results: Analysis of the image areas with DAPI and GFP fluorescences produced nearly identical quantification of epithelial cells in coculture with fibroblasts. We confinned these results by manual counting. In addition, GFP labeling permitted kinetic studies of the same coculture over multiple time points. Conclusions: The image analysis-based quantification method we describe here is an easy and reliable way to monitor cells in coculture and should be useful for a variety of cell biological studies. (C) 2002 Wiley-Liss, Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. NCI, Frederick, MD 21701 USA. RP Campisi, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd,MS 84-171, Berkeley, CA 94720 USA. RI Ortiz de Solorzano, Carlos/G-3278-2010 OI Ortiz de Solorzano, Carlos/0000-0001-8720-0205 FU NIA NIH HHS [AG09909]; PHS HHS [N01-C0-56000] NR 21 TC 18 Z9 18 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 0196-4763 J9 CYTOMETRY JI Cytometry PD OCT 1 PY 2002 VL 49 IS 2 BP 73 EP 82 DI 10.1002/cyto.10149 PG 10 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 601MY UT WOS:000178451400005 PM 12357463 ER PT J AU Yoo, B Kim, YH AF Yoo, B Kim, YH TI Study on effects of damping in laminated rubber bearings on seismic responses for a 1/8 scale isolated test structure SO EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS LA English DT Article DE damping in various LRB; seismic base isolation with high damping; shaking table tests; time-history analyses; 1/8-scale isolated test structure AB The effects of damping in various laminated rubber bearings (LRB) on the seismic response of a 1/8-scale isolated test structure are investigated by shaking table tests and seismic response analyses. A series of shaking table tests of the structure were performed for a fixed base design and for a base isolation design. Two different types of LRB were used: natural rubber bearings (NRB) and lead rubber bearings (LLRB). Three different designs for the LLRB were tested; each design had a different diameter of lead plug, and thus, different damping values. Artificial time histories of peak ground acceleration 0.4g were used in both the tests and the analyses. In both shaking table tests and analyses, as expected, the acceleration responses of the seismically isolated test structure were considerably reduced. However, the shear displacement at the isolators was increased. To reduce the shear displacement in the isolators, the diameter of the lead plug in the LLRB had to be enlarged to increase isolator damping by more than 24%. This caused the isolator stiffness to increase, and resulted in amplifying the floor acceleration response spectra of the isolated test structure in the higher frequency ranges with a monotonic reduction of isolator shear displacement. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Argonne Natl Lab, Reactor Anal & Engn Div, Argonne, IL 60439 USA. Korea Atom Energy Res Inst, Taejon, South Korea. Korea Adv Inst Sci & Technol, Dept Mech Engn, Taejon 305701, South Korea. RP Yoo, B (reprint author), Argonne Natl Lab, Reactor Anal & Engn Div, Bldg 208,9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 7 Z9 7 U1 1 U2 8 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0098-8847 J9 EARTHQUAKE ENG STRUC JI Earthq. Eng. Struct. Dyn. PD OCT PY 2002 VL 31 IS 10 BP 1777 EP 1792 DI 10.1002/eqe.186 PG 16 WC Engineering, Civil; Engineering, Geological SC Engineering GA 593PW UT WOS:000178002200002 ER PT J AU Norby, RJ Hanson, PJ O'Neill, EG Tschaplinski, TJ Weltzin, JF Hansen, RA Cheng, WX Wullschleger, SD Gunderson, CA Edwards, NT Johnson, DW AF Norby, RJ Hanson, PJ O'Neill, EG Tschaplinski, TJ Weltzin, JF Hansen, RA Cheng, WX Wullschleger, SD Gunderson, CA Edwards, NT Johnson, DW TI Net primary productivity of a CO2-enriched deciduous forest and the implications for carbon storage SO ECOLOGICAL APPLICATIONS LA English DT Article DE carbon allocation; carbon sequestration; CO2 enrichment; FACE (free-air CO2-enrichment) experiment; fine-root productivity; forest productivity; global change; heterotrophic respiration; Liquidambar styraciflua (sweetgum); net primary productivity ID CO2 ENRICHMENT; ATMOSPHERIC CO2; ELEVATED CO2; FUTURE FOREST; TREE GROWTH; RESPONSES; SOIL; ECOSYSTEMS; SEQUESTRATION; DIOXIDE AB A central question concerning the. response of terrestrial ecosystems to a changing atmosphere is whether increased uptake of carbon in response to increasing atmospheric carbon dioxide concentration results in greater plant biomass and carbon storage or, alternatively, faster cycling of C through the ecosystem. Net primary productivity (NPP) of a closed-canopy Liquidambar styraciflua (sweetgum) forest stand was assessed. for three years in a free-air CO2-enrichment (FACE) experiment. NPP increased 21 % in. stands exposed to elevated CO2, and there was no loss of response over time. Wood increment increased significantly during the first year of exposure, but subsequently most of the extra C was allocated to production of leaves and fine roots. These pools turn over more rapidly than wood, thereby reducing the potential of the forest stand to sequester additional C in response to atmospheric CO2 enrichment. Hence, while this experiment provides the first evidence that CO2 enrichment can increase productivity in a closed-canopy deciduous forest, the implications of this result must be tempered because the increase in productivity resulted, in faster cycling of C through the system rather than increased C storage in wood. The fate of the additional C entering the soil system and the environmental interactions that influence allocation need further investigation. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Ecol & Evolutionary Biol, Knoxville, TN 37996 USA. Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. Univ Calif Santa Cruz, Dept Environm Studies, Santa Cruz, CA 95064 USA. Univ Nevada, Dept Environm & Resource Sci, Reno, NV 89557 USA. RP Norby, RJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Norby, Richard/C-1773-2012; Cheng, Weixin/F-4968-2011; Hanson, Paul J./D-8069-2011; Wullschleger, Stan/B-8297-2012 OI Norby, Richard/0000-0002-0238-9828; Cheng, Weixin/0000-0003-2964-2376; Tschaplinski, Timothy/0000-0002-9540-6622; Hanson, Paul J./0000-0001-7293-3561; Wullschleger, Stan/0000-0002-9869-0446 NR 26 TC 146 Z9 160 U1 5 U2 45 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD OCT PY 2002 VL 12 IS 5 BP 1261 EP 1266 DI 10.2307/3099969 PG 6 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 614PM UT WOS:000179198600002 ER PT J AU Adams, SM Hill, WR Peterson, MJ Ryon, MG Smith, JG Stewart, AJ AF Adams, SM Hill, WR Peterson, MJ Ryon, MG Smith, JG Stewart, AJ TI Assessing recovery in a stream ecosystem: Applying multiple chemical and biological endpoints SO ECOLOGICAL APPLICATIONS LA English DT Article DE bioindicators; chemical and biological endpoints; disturbance; ecological significance; environmental stressors; mechanistic understanding; stream recovery ID CONTAMINANT EXPOSURE; CAUSAL INFERENCE; AMBIENT TOXICITY; FISH; DISTURBANCE; RESPONSES; PHOTOSYNTHESIS; VARIABILITY; TEMPERATURE; MANAGEMENT AB Recovery dynamics in a previously disturbed stream undergoing remediation was assessed by measuring several chemical and biological endpoints. Three major trophic levels (periphyton, benthic macroinvertebrates, and fish communities) were analyzed along with various biological indicators of fish health including sub-organismal (biochemical and physiological) and individual-level responses. Ambient toxicity testing, water quality measurements, and fish bioaccumulation studies were also conducted to provide additional indicators of stream recovery. Information on chemical loading, biological exposure (bioaccumulation), and bioassays help identify the underlying or mechanistic basis of recovery, while endpoints measured on instream biota, and particularly those at higher levels of biological organization, are key responses for understanding the dynamics and ecological significance of recovery. When assessing recovery in aquatic ecosystems, it is important to conduct long-term field studies incorporating a variety of response variables that represent a wide range of sensitivities and response time scales. The value of different endpoints for assessing recovery depends on the inherent characteristics that are related to response variability and sensitivity, specificity and causal relationships to stressors, and ecological relevance. Long-term data sets incorporating a variety and range of these endpoints are needed to improve our understanding of natural variability in streams and provide a baseline against which effects of disturbance and subsequent recovery processes can be evaluated. The complexity of aquatic systems and their variable recovery dynamics suggest that no single measure is adequate for assessing aquatic ecosystem recovery and that a suite of chemical and biological endpoints is required for a more complete understanding of ecosystem dynamics and status during both the recovery and the post-disturbance periods. Such information should be valuable to environmental managers and regulators in helping to make more informed decisions regarding effective management and mitigation practices in disturbed systems. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Adams, SM (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM Adamssm@ornl.gov OI stewart, arthur/0000-0003-1968-5997 NR 66 TC 31 Z9 33 U1 1 U2 26 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 EI 1939-5582 J9 ECOL APPL JI Ecol. Appl. PD OCT PY 2002 VL 12 IS 5 BP 1510 EP 1527 DI 10.2307/3099988 PG 18 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 614PM UT WOS:000179198600021 ER PT J AU Musameh, M Wang, J Merkoci, A Lin, YH AF Musameh, M Wang, J Merkoci, A Lin, YH TI Low-potential stable NADH detection at carbon-nanotube-modified glassy carbon electrodes SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE NADH; carbon nanotubes; fouling; electrocatalysis; biosensors ID NICOTINAMIDE ADENINE-DINUCLEOTIDE; OXIDATION AB Carbon-nanotube (CNT)-modified glassy carbon electrodes exhibiting strong and stable electrocatalytic response toward NADH are described. A substantial (490 mV) decrease in the overvoltage of the NADH oxidation reaction (compared to ordinary carbon electrodes) is observed using single-wall and multi-wall carbon-nanotube coatings, with oxidation starting at ca. -0.05 V (vs. Ag/AgCl; pH 7.4). Furthermore, the NADH amperometric response of the coated electrodes is extremely stable, with 96% and 90% of the initial activity remaining after 60 min stirring of 2 x 10(-4) and 5 x 10(-3) M NADH solutions, respectively (compared to 20% and 14% at the bare surface). The CNT-coated electrodes thus allow highly sensitive, low-potential, stable amperometric sensing. Such ability of carbon nanotubes to promote the NADH electron-transfer reaction suggests great promise for dehydrogenase-based amperometric biosensors. (C) 2002 Elsevier Science B.V. All rights reserved. C1 New Mexico State Univ, Dept Chem & Biochem, Las Cruces, NM 88003 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Wang, J (reprint author), New Mexico State Univ, Dept Chem & Biochem, Las Cruces, NM 88003 USA. RI Wang, Joseph/C-6175-2011; Lin, Yuehe/D-9762-2011; Merkoci, Arben/C-7211-2008 OI Lin, Yuehe/0000-0003-3791-7587; NR 11 TC 879 Z9 905 U1 23 U2 151 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1388-2481 J9 ELECTROCHEM COMMUN JI Electrochem. Commun. PD OCT PY 2002 VL 4 IS 10 BP 743 EP 746 AR PII S1388-2481(02)00451-4 DI 10.1016/S1388-2481(02)00451-4 PG 4 WC Electrochemistry SC Electrochemistry GA 605WB UT WOS:000178699100003 ER PT J AU Takai, H Naka, K Okada, Y Watanabe, M Harada, N Saito, S Anderson, CW Appella, E Nakanishi, M Suzuki, H Nagashima, K Sawa, H Ikeda, K Motoyama, N AF Takai, H Naka, K Okada, Y Watanabe, M Harada, N Saito, S Anderson, CW Appella, E Nakanishi, M Suzuki, H Nagashima, K Sawa, H Ikeda, K Motoyama, N TI Chk2-deficient mice exhibit radioresistance and defective p53-mediated transcription SO EMBO JOURNAL LA English DT Article DE ataxia-telangiectasia mutated (ATM); cell cycle checkpoint; DNA damage; phosphorylation; transcriptional activation ID ATM-DEPENDENT PHOSPHORYLATION; CELL-CYCLE CHECKPOINT; DNA-DAMAGE CHECKPOINT; ATAXIA-TELANGIECTASIA; IONIZING-RADIATION; GENOTOXIC STRESS; DEFICIENT MICE; NERVOUS-SYSTEM; HUMAN P53; KINASE AB The mammalian Chk2 kinase is thought to mediate ATM-dependent signaling in response to DNA damage. The physiological role of mammalian Chk2 has now been investigated by the generation of Chk2-deficient mice. Although Chk2(-/-) mice appeared normal, they were resistant to ionizing radiation (IR) as a result of the preservation of splenic lymphocytes. Thymocytes and neurons of the developing brain were also resistant to IR-induced apoptosis. The IR-induced G(1)/S cell cycle checkpoint, but not the G(2)/M or S phase checkpoints, was impaired in embryonic fibroblasts derived from Chk2(-/-) mice. IR-induced stabilization of p53 in Chk2(-/-) cells was 50-70% of that in wild-type cells. Caffeine further reduced p53 accumulation, suggesting the existence of an ATM/ ATR-dependent but Chk2-independent pathway for p53 stabilization. In spite of p53 protein stabilization and phosphorylation of Ser23, p53-dependent transcriptional induction of target genes, such as p21 and Noxa, was not observed in Chk2(-/-) cells. Our results show that Chk2 plays a critical role in p53 function in response to IR by regulating its transcriptional activity as well as its stability. C1 Natl Inst Longev Sci, Dept Geriatr Res, Aichi 4748522, Japan. Hokkaido Univ, Grad SchMed, Lab Mol & Cellular Pathol, Sapporo, Hokkaido 0608638, Japan. JST, CREST, Sapporo, Hokkaido 0608638, Japan. Chugai Pharmaceut Co Ltd, Res Labs, Shizuoka 4128513, Japan. Nagoya City Univ, Sch Med, Dept Biochem, Nagoya, Aichi 4678601, Japan. NCI, Cell Biol Lab, NIH, Bethesda, MD 20892 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Motoyama, N (reprint author), Natl Inst Longev Sci, Dept Geriatr Res, Aichi 4748522, Japan. RI Takai, Hiroyuki/B-8352-2011; Sawa, Hirofumi/F-6954-2012 NR 53 TC 300 Z9 303 U1 0 U2 10 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0261-4189 J9 EMBO J JI Embo J. PD OCT 1 PY 2002 VL 21 IS 19 BP 5195 EP 5205 DI 10.1093/emboj/cdf506 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 602JR UT WOS:000178502600019 PM 12356735 ER EF