FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Du Frane, WL Roberts, JJ Toffelmier, DA Tyburczy, JA AF Du Frane, WL Roberts, JJ Toffelmier, DA Tyburczy, JA TI Anisotropy of electrical conductivity in dry olivine SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SAN CARLOS OLIVINE; MANTLE; PRESSURE; HYDROGEN AB The electrical conductivity (sigma) was measured for a single crystal of San Carlos olivine (Fo(89.1)) for all three principal orientations over oxygen fugacities 10(-7) < f(O2) < 10(1) Pa at 1100, 1200, and 1300 degrees C. Fe-doped Pt electrodes were used in conjunction with a conservative range of f(O2), T, and time to reduce Fe loss resulting in data that is similar to 0.15 log units higher in conductivity than previous studies. At 1200 degrees C and f(O2) = 10(-1) Pa, sigma([100]) = 10(-2.27) S/m, sigma([010]) = 10(-2.49) S/m, sigma([001]) = 10(-2.40) S/m. The dependences of sigma on T and f(O2) have been simultaneously modeled with undifferentiated mixed conduction of small polarons and Mg vacancies to obtain steady-state f(O2)-independent activation energies: Ea([100]) = 0.32 eV, Ea([010]) = 0.56 eV, Ea([001]) = 0.71 eV. A single crystal of dry olivine would provide a maximum of similar to 10(0.4) S/m azimuthal s contrast for T < 1500 degrees C. The anisotropic results are combined to create an isotropic model with Ea = 0.53 eV. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Lawrence Livermore Natl Lab, Expt Geophys Grp, Livermore, CA 94550 USA. RP Du Frane, WL (reprint author), Arizona State Univ, Dept Geol Sci, Box 871404, Tempe, AZ 85287 USA. EM wyatt.dufrane@asu.edu RI Du Frane, Wyatt/D-6879-2013 NR 23 TC 37 Z9 37 U1 3 U2 16 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 DEC 31 PY 2005 VL 32 IS 24 AR L24315 DI 10.1029/2005GL023879 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 001AZ UT WOS:000234506100001 ER PT J AU Kollias, P Albrecht, B AF Kollias, P Albrecht, B TI Why the melting layer radar reflectivity is not bright at 94 GHz SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PRECIPITATION; MODEL AB At 94 GHz, the highest radar frequency used for atmospheric research, no radar bright band is observed at the melting layer. In this study, simulations of a vertical profile of melting particles and their scattering properties for a variety of melting particle models are used to capture the basic features of the radar reflectivity structure at 94 GHz in the melting layer. Observations of stratiform precipitation from vertically pointing 3 GHz and 94 GHz radars are used for comparison with the model results. The simulations show good agreement with the observations. The melting of precipitating particles results in an abrupt increase in the radar reflectivity at 94 GHz without a subsequent decrease at the base of the melting layer. The simulations also captured a small decrease in the radar reflectivity at 94 GHz ( dark band) often observed at the top of the melting layer. C1 Brookhaven Natl Lab, Dept Atmospher Sci, Upton, NY 11973 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Kollias, P (reprint author), Brookhaven Natl Lab, Dept Atmospher Sci, Upton, NY 11973 USA. EM pkollias@bnl.gov NR 19 TC 13 Z9 14 U1 2 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 31 PY 2005 VL 32 IS 24 AR L24818 DI 10.1029/2005GL024074 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 001AZ UT WOS:000234506100002 ER PT J AU Bao, RY Lykken, J AF Bao, RY Lykken, J TI Randall-sundrum brane model with 7D anti-de Sitter space SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIERARCHY; COMPACTIFICATION; DIMENSIONS AB In the same sense that 5D anti-de Sitter space (AdS(5)) warped geometries arise naturally from type IIB string theory with stacks of D3 branes, AdS(7) warped geometries arise naturally from M theory with stacks of M5 branes. We compactify two spatial dimensions of AdS(7) to get AdS(5)x Sigma(2), where the metric for Sigma(2) inherits the same warp factor as appears in the AdS(5). We analyze the 5D spectrum in detail for the case of a bulk scalar or a graviton in AdS(5)xT(2), in a setup which mimics the first Randall-Sundrum model. The results display novel features which might be observed in experiments at the CERN Large Hadron Collider. For example, we obtain TeV scale string winding states without lowering the string scale. This is due to the double warping which is a generic feature of winding states along compactified AdS directions. Experimental verification of these signatures of AdS(7) could be interpreted as direct evidence for M theory. C1 Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Bao, RY (reprint author), Univ Chicago, Enrico Fermi Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 17 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 261601 DI 10.1103/PhysRevLett.95.261601 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900021 PM 16486337 ER PT J AU Booth, CH Walter, MD Daniel, M Lukens, WW Andersen, RA AF Booth, CH Walter, MD Daniel, M Lukens, WW Andersen, RA TI Self-contained Kondo effect in single molecules SO PHYSICAL REVIEW LETTERS LA English DT Article ID STATE; CEROCENE; CERIUM; TRANSISTOR; COMPLEXES AB Kondo coupling of f and conduction electrons is a common feature of f-electron intermetallics. Similar effects should occur in carbon ring systems (metallocenes). Evidence for Kondo coupling in Ce(C8H8)(2) (cerocene) and the ytterbocene (Cp2Yb)-Yb-*(bipy) is reported from magnetic susceptibility and L-III-edge x-ray absorption spectroscopy. These well-defined systems provide a new way to study the Kondo effect on the nanoscale, should generate insight into the Anderson Lattice problem, and indicate the importance of this often-ignored contribution to bonding in organometallics. C1 Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Booth, CH (reprint author), Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Booth, Corwin/A-7877-2008; Walter, Marc/E-4479-2012 NR 25 TC 65 Z9 65 U1 2 U2 19 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 267202 DI 10.1103/PhysRevLett.95.267202 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900077 PM 16486392 ER PT J AU Bouhelier, A Bachelot, R Lerondel, G Kostcheev, S Royer, P Wiederrecht, GP AF Bouhelier, A Bachelot, R Lerondel, G Kostcheev, S Royer, P Wiederrecht, GP TI Surface plasmon characteristics of tunable photoluminescence in single gold nanorods SO PHYSICAL REVIEW LETTERS LA English DT Article ID NANOPARTICLES; LUMINESCENCE; FEMTOSECOND; ENHANCEMENT; METALS; MELT AB Light emission resulting from two-photon excited gold nanoparticles has been proposed to originate from the radiative decay of surface plasmon resonances. In this vein, we investigated luminescence from individual gold nanorods and found that their emission characteristics closely resemble surface plasmon behavior. In particular, we observed spectral similarities between the scattering spectra of individual nanorods and their photoluminescence emission. We also measured a blueshift of the photoluminescence peak wavelength with decreasing aspect ratio of the nanorods as well as an optically tunable shape-dependent spectrum of the photoluminescence. The emission yield of single nanorods strongly depends on the orientation of the incident polarization consistent with the properties of surface plasmons. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. Univ Technol Troyes, Lab Nanotechnol & Instrumentat Opt, CNRS, FRE 2671, F-10010 Troyes, France. RP Bouhelier, A (reprint author), Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RI Bouhelier, Alexandre/A-1960-2010; Lerondel, Gilles/D-1559-2011; Bachelot, Renaud/M-6888-2015 NR 21 TC 256 Z9 258 U1 9 U2 104 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 DEC 31 PY 2005 VL 95 IS 26 AR 267405 DI 10.1103/PhysRevLett.95.267405 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900090 PM 16486405 ER PT J AU Buras, AJ Gorbahn, M Haisch, U Nierste, U AF Buras, AJ Gorbahn, M Haisch, U Nierste, U TI Rare decay K+ -> pi(+)nu(nu)over-bar at the next-to-next-to-leading order in QCD SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUARK MASSES; KAON DECAYS; CKM MATRIX; B-DECAYS; 3 LOOPS; K->PI-NU(NU)OVER-BAR; (MS)OVER-BAR; VIOLATION AB We calculate the charm quark contribution to the rare decay K+->pi(+)nu(nu) over bar in the next-to-next-to-leading order of QCD. This new contribution reduces the theoretical uncertainty in the relevant parameter P-c from +/- 10.1% down to +/- 2.4%, corresponding to scale uncertainties of +/- 1.3%, +/- 1.0%, +/- 0.006, and +/- 1.2 degrees in B(K+->pi(+)nu(nu) over bar) and in vertical bar V-td vertical bar, sin2 beta, and gamma extracted from the K ->pi nu(nu) over bar system. The error in P-c = 0.37 +/- 0.04 is now fully dominated by the current uncertainty of +/- 3.8% in the charm quark mass m(c). We find B(K+->pi(+)nu(nu) over bar) = (8.0 +/- 1.1)x10(-11), where the quoted error stems almost entirely from the present uncertainties in m(c) and the Cabibbo-Kobayashi-Maskawa elements. C1 Tech Univ Munich, Dept Phys, D-85748 Garching, Germany. Univ Durham, Dept Phys, IPPP, Durham DH1 3LE, England. Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Tech Univ Munich, Dept Phys, D-85748 Garching, Germany. NR 45 TC 72 Z9 72 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 DEC 31 PY 2005 VL 95 IS 26 AR 261805 DI 10.1103/PhysRevLett.95.261805 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900028 PM 16486344 ER PT J AU Chasman, RR AF Chasman, RR TI Variational approach to configuration interaction SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY; O-16 AB A variational method is developed to determine configuration interaction wave functions. The method is straightforward and is applied to a pairing Hamiltonian with constant matrix elements, for which exact eigenvalues are available. Comparisons are made with the exact results. Calculations can be carried out to any desired degree of accuracy. The method is also applied to a Hamiltonian that has neutron-neutron, proton-proton, and neutron-proton pairing. No difficulties are found in extending the method to this Hamiltonian that has many collective modes. In practice, the method scales linearly with N, where N is the number of variational basis states. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Chasman, RR (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 14 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 262501 DI 10.1103/PhysRevLett.95.262501 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900030 ER PT J AU Cooley, LD Zambano, AJ Moodenbaugh, AR Klie, RF Zheng, JC Zhu, YM AF Cooley, LD Zambano, AJ Moodenbaugh, AR Klie, RF Zheng, JC Zhu, YM TI Inversion of two-band superconductivity at the critical electron doping of (Mg,Al)B-2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-LEVEL; T-C; MGB2; AL; POLYCRYSTALLINE; MG1-XALXB2; DIBORIDE; HEAT AB Electron energy-loss spectroscopy (EELS) was combined with heat capacity measurements to probe changes of electronic structure and superconductivity in Mg(1-x)AlxB2. A simultaneous decrease of EELS intensity from sigma-band hole states and the magnitude of the sigma gap was observed with increasing x, thus verifying that band filling results in the loss of strong superconductivity. These quantities extrapolated to zero at x approximate to 0.33 as inferred from the unit cell volume. However, superconductivity was not quenched completely, but persisted with T-c< 7 K up to about x approximate to 55. Only the pi band had detectable density of states for 0.33 less than or similar to x less than or similar to 0.55, implying an inversion of the two-band hierarchy of MgB2 in that regime. Since pi-band superconductivity is active in other materials such as intercalated graphite, implications for new materials with high T-c are discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Cooley, LD (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Zheng, JC/G-3383-2010; Cooley, Lance/E-7377-2015 OI Zheng, JC/0000-0002-6292-3236; Cooley, Lance/0000-0003-3488-2980 NR 33 TC 30 Z9 30 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 DEC 31 PY 2005 VL 95 IS 26 AR 267002 DI 10.1103/PhysRevLett.95.267002 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900075 PM 16486390 ER PT J AU Erlich, J Katz, E Son, DT Stephanov, MA AF Erlich, J Katz, E Son, DT Stephanov, MA TI QCD and a holographic model of hadrons SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYMMETRY-BREAKING; PHYSICS AB We propose a five-dimensional framework for modeling low-energy properties of QCD. In the simplest three parameter model we compute masses, decay rates and couplings of the lightest mesons. The model fits experimental data to within 10%. The framework is a holographic version of the QCD sum rules, motivated by the anti-de Sitter/conformal field theory correspondence. The model naturally incorporates properties of QCD dictated by chiral symmetry, which we demonstrate by deriving the Gell-Mann-Oakes-Renner relationship for the pion mass. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NR 23 TC 617 Z9 620 U1 2 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 261602 DI 10.1103/PhysRevLett.95.261602 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900022 PM 16486338 ER PT J AU Gorelenkov, NN AF Gorelenkov, NN TI Double-gap Alfven eigenmodes: Revisiting eigenmode interaction with the Alfven continuum SO PHYSICAL REVIEW LETTERS LA English DT Article ID AXISYMMETRICAL TOROIDAL PLASMAS; RESONANCE; WAVES; MODE AB A new type of global shear Alfven eigenmode is found in tokamak plasmas where the mode localization is in the region intersecting the Alfven continuum. The eigenmode is formed by the coupling of two solutions from two adjacent gaps (akin to potential wells) in the shear Alfven continuum. For tokamak plasmas with reversed magnetic shear, it is shown that the toroidicity-induced solution tunnels through the continuum to match the ellipticity-induced Alfven eigenmode so that the resulting solution is continuous at the point of resonance with the continuum. The existence of these double-gap Alfven eigenmodes allows for potentially new ways of coupling edge fields to the plasma core in conditions where the core region is conventionally considered inaccessible. Implications include new approaches to heating and current drive in fusion plasmas as well as its possible use as a core diagnostic in burning plasmas. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Gorelenkov, NN (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 12 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 265003 DI 10.1103/PhysRevLett.95.265003 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900051 PM 16486366 ER PT J AU Hewett, JL Lillie, B Rizzo, TG AF Hewett, JL Lillie, B Rizzo, TG TI Black holes in many dimensions at the CERN Large Hadron Collider: Testing critical string theory SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXTRA DIMENSIONS; GRAVITY; BRANES AB We consider black hole production at the CERN Large Hadron Collider (LHC) in a generic scenario with many extra dimensions where the standard model fields are confined to a brane. With similar to 20 dimensions the hierarchy problem is shown to be naturally solved without the need for large compactification radii. We find that in such a scenario the properties of black holes can be used to determine the number of extra dimensions, n. In particular, we demonstrate that measurements of the decay distributions of such black holes at the LHC can determine if n is significantly larger than 6 or 7 with high confidence and thus can probe one of the critical properties of string theory compactifications. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Hewett, JL (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. EM hewett@slac.stanford.edu; lillieb@slac.stanford.edu; rizzo@slac.stanford.edu NR 31 TC 15 Z9 15 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 261603 DI 10.1103/PhysRevLett.95.261603 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900023 PM 16486339 ER PT J AU Prasankumar, RP Okamura, H Imai, H Shimakawa, Y Kubo, Y Trugman, SA Taylor, AJ Averitt, RD AF Prasankumar, RP Okamura, H Imai, H Shimakawa, Y Kubo, Y Trugman, SA Taylor, AJ Averitt, RD TI Coupled charge-spin dynamics of the magnetoresistive pyrochlore Tl2Mn2O7 probed using ultrafast midinfrared spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID CARRIER DENSITY; COLOSSAL-MAGNETORESISTANCE; GIANT MAGNETORESISTANCE; DEPENDENCE; TRANSPORT; EXCHANGE; TL AB Optical-pump midinfrared probe spectroscopy is used to investigate coupled charge-spin dynamics in the magnetoresistive pyrochlore Tl2Mn2O7. We find that the temporal persistence of the photoexcited carrier density is strongly influenced by spin disorder above and below the ferromagnetic Curie temperature. Our results are consistent with a picture whereby spin disorder leads to spatial segregation of the initially excited Tl 6s-O 2p electron-hole pairs, effectively reducing the probability for recombination. This further implies that colossal magnetoresistance in these materials may be driven primarily by Mn t(2g) spin disorder. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Kobe Univ, Grad Sch Sci & Technol, Kobe, Hyogo 6578501, Japan. NEC Corp Ltd, Fundamental Res Labs, Tsukuba, Ibaraki 3058501, Japan. RP Prasankumar, RP (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM rpprasan@lanl.gov RI KUBO, Yoshimi/H-2851-2011 NR 25 TC 9 Z9 9 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 31 PY 2005 VL 95 IS 26 AR 267404 DI 10.1103/PhysRevLett.95.267404 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900089 PM 16486404 ER PT J AU Seidel, A Fu, H Lee, DH Leinaas, JM Moore, J AF Seidel, A Fu, H Lee, DH Leinaas, JM Moore, J TI Incompressible quantum liquids and new conservation laws SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRIANGULAR LATTICE; EXCITATIONS; STATE; SUPERCONDUCTIVITY; SYSTEMS; PHASE AB In this Letter, we investigate a class of Hamiltonians which, in addition to the usual center-of-mass momentum conservation, also have center-of-mass position conservation. We find that, regardless of the particle statistics, the energy spectrum is at least q-fold degenerate when the filling factor is p/q, where p and q are coprime integers. Interestingly, the simplest Hamiltonian respecting this type of symmetry encapsulates two prominent examples of novel states of matter, namely, the fractional quantum Hall liquid and the quantum dimer liquid. We discuss the relevance of this class of Hamiltonian to the search for featureless Mott insulators. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Tsinghua Univ, Ctr Adv Study, Beijing 100084, Peoples R China. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Fu, Henry/F-2861-2014; Moore, Joel/O-4959-2016 OI Moore, Joel/0000-0002-4294-5761 NR 31 TC 73 Z9 73 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 DEC 31 PY 2005 VL 95 IS 26 AR 266405 DI 10.1103/PhysRevLett.95.266405 PG 4 WC Physics, Multidisciplinary SC Physics GA 998RV UT WOS:000234337900066 PM 16486381 ER PT J AU Weronski, P AF Weronski, P TI Application of the extended RSA models in studies of particle deposition at partially covered surfaces SO ADVANCES IN COLLOID AND INTERFACE SCIENCE LA English DT Article DE adsorption of colloid particles; particle electrostatic interaction; colloid deposition; Monte Carlo simulation; random sequential adsorption; RSA model ID RANDOM-SEQUENTIAL ADSORPTION; SITE HETEROGENEOUS SURFACES; ASYMPTOTIC-BEHAVIOR; JAMMING LIMIT; HARD-SPHERES; IRREVERSIBLE ADSORPTION; ANISOTROPIC PARTICLES; STATISTICAL MECHANICS; SPHEROIDAL PARTICLES; LOCALIZED ADSORPTION AB This paper reviews the application of the extended random sequential adsorption (RSA) approaches to the modeling of colloid-particle deposition (irreversible adsorption) on surfaces precovered with smaller particles. Hard (noninteracting) particle systems are discussed first. We report on the numerical simulations we performed to determine the available surface function, jamming coverage, and pair-correlation function of the larger particles. We demonstrate the effect of the particle size ratio and the small particle surface coverage. We found that the numerical results were in reasonable agreement with the formula stemming from the scaled-particle theory in 2D with a modification for the sphere geometry. Next, we discuss three approximate models of adsorption allowing electrostatic interaction of colloid particles at a charged interface, employing a many-body superposition approximation. We describe two approaches of the effective hard-particle approximation next. We demonstrate the application of the effective hard-particle concept to the bimodal systems and present the effect of electrolyte concentration on the effective particle size ratio. We present the numerical results obtained from the theoretical models of soft-particle adsorption at precovered surfaces. We used the effective hard-particle approximation to determine the corresponding simpler systems of particles, namely the system of hard spheres and the system of hard discs at equilibrium. We performed numerical computations to determine the effective minimum particle surface-to-surface distance, available surface function, jamming coverage, and pair-correlation function of the larger particles at various electrolyte ionic strengths and particle size ratios. The numerical results obtained in the low-surface coverage limit were in good agreement with the formula stemming from the scaled-particle theory with a modification for the sphere geometry and electrostatic interaction. We compared the results of numerical computations of the effective minimum particle surface-to-surface distance obtained using the 2D, 3D, and curvilinear trajectory model. The results obtained with the 3D and curvilinear trajectory models indicate that large-particle/substrate attractive interaction significantly reduces the kinetic barrier to large, charged-particle adsorption at a surface precovered with small, like-charged particles. The available surface function and jamming-coverage values predicted using the simplified 3D and the more sophisticated curvilinear trajectory models are similar, while the results obtained with the 2D model differ significantly. The pair-correlation function suggests different structures of monolayers obtained with the three models. Unlike the three models of the electrostatic interaction, both effective hard-particle approximations give almost identical results. Results of this research clearly suggest that the extended RSA approaches can fruitfully be exploited for numerical simulations of colloid-particle adsorption at precovered surfaces, allowing the investigation of both hard and soft-particle systems. Published by Elsevier B.V. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Polish Acad Sci, Inst Catalysis & Surface Chem, PL-30239 Krakow, Poland. RP Weronski, P (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM pawel@cnls.lanl.gov NR 57 TC 20 Z9 20 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0001-8686 J9 ADV COLLOID INTERFAC JI Adv. Colloid Interface Sci. PD DEC 30 PY 2005 VL 118 IS 1-3 BP 1 EP 24 DI 10.1016/j.cis.2005.03.002 PG 24 WC Chemistry, Physical SC Chemistry GA 000QJ UT WOS:000234476800001 PM 16084783 ER PT J AU Danilov, IG Parham, JF AF Danilov, IG Parham, JF TI A reassessment of the referral of an isolated skull from the Late Cretaceous of Uzbekistan to the stem-testudinoid turtle genus Lindholmemys SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article ID PHYLOGENY AB A fossil turtle skull (ZISP PH 1/17) from the Late Cretaceous (upper Turonian, Bissekty Formation) of Dzharakuduk (Uzbekistan, Asia) was used to score the skull characters for the genus Lindholmemys (a stem testudinoid) in a recent phylogenetic analysis. A description of ZISP PH 1/17 and a new cladistic analysis reveals no characters to support its referral to Lindholmemys elegans or to the stem-testudinoid lineage. ZISP PH 1/17 is very similar to North American Adocus, differing mainly in characters of the upper jaw. Therefore, we hypothesize that ZISP PH 1/17 is the skull of either Shachemys ancestralis or "Adocus" aksary, adocid shell taxa from Dzharakuduk. Pending additional discoveries and description of turtles from Dzharakuduk, we refer ZISP PH 1/17 to Adocidae, gen. et sp. indet. C1 Russian Acad Sci, Inst Zool, Dept Herpetol, St Petersburg 199034, Russia. Univ Calif Berkeley, Museum Paleontol, Berkeley, CA 94720 USA. Joint Genome Inst, Evolutionary Genom Dept, Walnut Creek, CA 94598 USA. RP Danilov, IG (reprint author), Russian Acad Sci, Inst Zool, Dept Herpetol, Universitetskaya Emb 1, St Petersburg 199034, Russia. EM dig@mail333.com; parham@socrates.berkeley.edu NR 21 TC 15 Z9 16 U1 0 U2 1 PU SOC VERTEBRATE PALEONTOLOGY PI NORTHBROOK PA 60 REVERE DR, STE 500, NORTHBROOK, IL 60062 USA SN 0272-4634 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD DEC 30 PY 2005 VL 25 IS 4 BP 784 EP 791 DI 10.1671/0272-4634(2005)025[0784:AROTRO]2.0.CO;2 PG 8 WC Paleontology SC Paleontology GA 003PI UT WOS:000234693700004 ER PT J AU Holroyd, PA Parham, JF Hutchison, JH AF Holroyd, PA Parham, JF Hutchison, JH TI A reappraisal of some Paleogene turtles from the Southeastern United States SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article ID PALEOCENE C1 Univ Calif Berkeley, Museum Paleontol, Berkeley, CA 94720 USA. Joint Genome Inst, Evolutionary Genom Dept, Walnut Creek, CA 94598 USA. RP Holroyd, PA (reprint author), Univ Calif Berkeley, Museum Paleontol, Berkeley, CA 94720 USA. EM pholroyd@berkeley.edu NR 36 TC 6 Z9 6 U1 0 U2 1 PU SOC VERTEBRATE PALEONTOLOGY PI NORTHBROOK PA 60 REVERE DR, STE 500, NORTHBROOK, IL 60062 USA SN 0272-4634 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD DEC 30 PY 2005 VL 25 IS 4 BP 979 EP 982 DI 10.1671/0272-4634(2005)025[0979:AROSPT]2.0.CO;2 PG 4 WC Paleontology SC Paleontology GA 003PI UT WOS:000234693700022 ER PT J AU Burr, T Jacobson, A Mielke, A AF Burr, T Jacobson, A Mielke, A TI A dynamic global radio frequency noise survey as observed by the FORTE satellite at 800 km altitude SO RADIO SCIENCE LA English DT Article AB [1] Detecting transient events in noisy time series is complicated by several issues. We focus on the issue of nonstationary noise, illustrate an approach ("dynamic'' strategy) on radio frequency (RF) observations from the FORTE satellite that frequently updates the estimated background, and provide a dynamic survey of FORTE noise. The performance measure is the distribution of R-2/(R-2) over bar, where R-2 is the squared noise amplitude at a given frequency and (R-2) over bar is the most recent mean squared amplitude. The definition of "most recent'' ranges from 10 mu s to 10 s. We also vary the fraction of the update period used to compute the mean from 0.1% to 100% of the previous period. For FORTE, we define 13 geographic regions and analyze signal-free records ( assumed to be representative of the noise, but discussion is provided). The best dynamic case is compared to a static strategy that uses R-2/(R-2) over bar (static), where (R-2) over bar (static) is the mean over a period that covers tens of days ( tens of days is the time required for the variance of the noise to reach its maximum). It is shown that some type of dynamic strategy has better statistical sensitivity than the static strategy. This survey illustrates one way to select an "update-the-mean'' strategy that is applicable in many settings. We also describe a multiband triggering method, which together with the update-the-mean strategy helps establish the lower limit of detection of signals of interest, for example, in the case of FORTE, in satellite-based long-baseline radio astronomy and in cosmic ray shower RF emissions. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Burr, T (reprint author), Los Alamos Natl Lab, MS F600, Los Alamos, NM 87545 USA. EM tburr@lanl.gov NR 12 TC 0 Z9 0 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD DEC 30 PY 2005 VL 40 IS 6 AR RS6016 DI 10.1029/2005RS003246 PG 16 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 001BQ UT WOS:000234508000001 ER PT J AU Bratlie, KM Flores, LD Somorjai, GA AF Bratlie, KM Flores, LD Somorjai, GA TI Hydrogenation and dehydrogenation of cyclohexene on Pt(100): A sum frequency generation vibrational spectroscopic and kinetic study SO SURFACE SCIENCE LA English DT Article DE catalytic reaction; C-6 hydrocarbons; Pt(100); Pt(111); hydrogenation; dehydrogenation; sum frequency generation; SFG ID CYCLIC C-6 HYDROCARBONS; PT(111) CRYSTAL-SURFACE; CATALYTIC-REACTIONS; PRESSURE; 1,4-CYCLOHEXADIENE; ADSORPTION; 1,3-CYCLOHEXADIENE; INTERMEDIATE; MOLECULES; BENZENE AB Sum frequency generation (SFG) vibrational spectroscopy and kinetic measurements were performed during cyclohexene hydrogenation/dehydrogenation over a range of pressures (10(-S)-5 Torr) and temperatures (300-500 K) on the Pt(I 00) surface. Upon adsorption at pressures below 1.5 Torr and at 300 K, cyclohexene dehydrogenates to form pi-allyl c-C6H9 and hydrogenates to form cyclohexyl (C6H11) surface intermediates. Increasing the pressure to 1.5 Torr produces adsorbed 1,4-cyclohexadiene, pi-allyl c-C6H9, and cyclohexyl species. These adsorbed molecules are found both in the absence and presence of excess hydrogen on the Pt(I 0 0) surface at high pressures and up to 380 K and 360 K, respectively. pi-Allyl c-C6H9 and cyclohexyl are adsorbed on the surface up to 440 K in the absence of excess hydrogen and 460 K in the presence of excess hydrogen, at which point they are no longer detectable by SFG. Kinetic studies in the absence of excess hydrogen show that the apparent activation energy for the dehydrogenation pathway (14.3 +/- 1.2 kcal/mol) is similar to that of the hydrogenation pathway (12.9 +/- 0.6 kcal/mol). Different apparent activation energies are observed for the dehydrogenation pathway (22.4 +/- 1.6 kcal/mol) and the hydrogenation pathway (18.8 +/- 0.9 kcal/mol) in the presence of excess hydrogen. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM somorjai@socrates.berkeley.edu RI Bratlie, Kaitlin/A-1133-2009 NR 27 TC 35 Z9 35 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 30 PY 2005 VL 599 IS 1-3 BP 93 EP 106 DI 10.1016/j.susc.2005.09.051 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 995VN UT WOS:000234132600011 ER PT J AU Waters, T Wang, XB Li, SG Kiran, B Dixon, DA Wang, LS AF Waters, T Wang, XB Li, SG Kiran, B Dixon, DA Wang, LS TI Electronic structure of the hydroxo and methoxo oxometalate anions MO3(OH)(-) and MO3(OCH3)(-) (M = Cr, Mo, and W) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; BOND-DISSOCIATION ENERGIES; OXIDE-BASED CATALYSTS; GAS-PHASE; PHOTOELECTRON-SPECTROSCOPY; SELECTIVE OXIDATION; BASIS-SETS; AB-INITIO; METHANE; CLUSTERS AB The electronic structure of the mononuclear hydroxo MO3(OH)(-) and methoxo MO3(OCH3)(-) Group 6 oxometalate anions (M = Cr, Mo, and W) were examined by photodetachment photoelectron spectroscopy and electronic structure calculations at the density functional and CCSD(T) levels of theory. All of the anions exhibited high electron binding energies (> 4.9 eV), with the lowest-energy detachment features arising from oxygen 2p-based orbitals. The combined experimental and theoretical results allowed the change in molecular orbital energy levels to be investigated as a function of metal (Cr, Mo, or W) and ligand (-OH, -OCH3). A number of fundamental thermodynamic properties of the anions and corresponding neutrals were predicted on the basis of the theoretical calculations. The calculations indicate high O-H bond dissociation energies for MO2(OR)(O-H) (R = H, CH3) and MO3(O-H), consistent with their high Bronsted acidities (just below that of H2SO4 in the gas phase) and the high ionization energies of their conjugate base anions. This suggests that the corresponding radicals should readily abstract H atoms from organic molecules. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, Div Chem Sci, W R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. EM ls.wang@pnl.gov NR 67 TC 12 Z9 12 U1 0 U2 4 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 DEC 29 PY 2005 VL 109 IS 51 BP 11771 EP 11780 DI 10.1021/jp054666x PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 997PV UT WOS:000234259800017 PM 16366627 ER PT J AU Cappa, CD Drisdell, WS Smith, JD Saykally, RJ Cohen, RC AF Cappa, CD Drisdell, WS Smith, JD Saykally, RJ Cohen, RC TI Isotope fractionation of water during evaporation without condensation SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; MASS ACCOMMODATION COEFFICIENT; TRAIN/FLOW REACTOR EXPERIMENT; AIR/WATER INTERFACE; KINETIC LIMITATIONS; LIQUID INTERFACES; DROPLET FORMATION; REVISED ANALYSIS; VAPOR-PRESSURE; H2O AB The microscopic events engendering liquid water evaporation have received much attention over the last century, but remain incompletely understood. We present measurements of isotope fractionation occurring during, free molecular evaporation from liquid microjets and show that the isotope ratios of evaporating molecules exhibit dramatic differences from equilibrium vapor values, strong variations with the solution deuterium mole fraction, and a clear temperature dependence. These results indicate the existence of an energetic barrier to evaporation and that the evaporation coefficient of water is less than unity. These new insights into water evaporation promise to advance our understanding of the processes that control the formation and lifetime of clouds in the atmosphere. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Cohen, RC (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Cohen, Ronald/A-8842-2011 OI Cohen, Ronald/0000-0001-6617-7691 NR 54 TC 35 Z9 35 U1 3 U2 26 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 DEC 29 PY 2005 VL 109 IS 51 BP 24391 EP 24400 DI 10.1021/jp0539066 PG 10 WC Chemistry, Physical SC Chemistry GA 997PW UT WOS:000234259900027 PM 16375440 ER PT J AU Barnard, AS Lin, XM Curtiss, LA AF Barnard, AS Lin, XM Curtiss, LA TI Equilibrium morphology of face-centered cubic gold nanoparticles > 3 nm and the shape changes induced by temperature SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID RESOLUTION ELECTRON-MICROSCOPY; ENHANCED RAMAN-SCATTERING; TOTAL-ENERGY CALCULATIONS; AUGMENTED-WAVE METHOD; MOLECULAR-DYNAMICS; METAL-CLUSTERS; STRUCTURAL-PROPERTIES; MELTING TEMPERATURE; AU(001) SURFACE; SMALL PARTICLES AB Many of the unique properties of metallic nanoparticles are determined not only by their finite size but also by their shape, defined by the crystallographic orientation of the surface facets. These surfaces (and therefore the nanoparticles themselves) may differ in a number of ways, including surface atom densities, electronic structure, bonding, chemical reactivities, and thermodynamic properties. In the case of gold, it is known that the melting temperature of nanoparticles strongly depends on the crystal size and that the shape may alter considerably (and yet somewhat unpredictably) during annealing. In this work we use first principle calculations and a thermodynamic model to investigate the morphology of gold nanoparticles in the range 3-100 nm. The results predict that the equilibrium shape of gold nanoparticles is a modified truncated octahedron and that the (size-dependent) melting of such particles is preceded by a significant change in the nanoparticle's morphology. C1 Univ Oxford, Dept Mat, Oxford OX1 3PH, England. Argonne Natl Lab, Ctr Nanoscale Mat, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Univ Oxford, Dept Mat, Parks Rd, Oxford OX1 3PH, England. EM amanda.barnard@materials.ox.ac.uk RI Barnard, Amanda/A-7340-2011 OI Barnard, Amanda/0000-0002-4784-2382 NR 73 TC 90 Z9 92 U1 1 U2 32 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 DEC 29 PY 2005 VL 109 IS 51 BP 24465 EP 24472 DI 10.1021/jp054279n PG 8 WC Chemistry, Physical SC Chemistry GA 997PW UT WOS:000234259900036 PM 16375449 ER PT J AU Abreu, IA Rodriguez, JA Cabelli, DE AF Abreu, IA Rodriguez, JA Cabelli, DE TI Theoretical studies of manganese and iron superoxide dismutases: Superoxide binding and superoxide oxidation SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NITROGENASE FEMO COFACTOR; ACTIVE-SITE; ESCHERICHIA-COLI; THERMUS-THERMOPHILUS; CRYSTAL-STRUCTURE; CHEMICAL ACTIVITY; ELECTRON-TRANSFER; GLUTAMINE 143; LIGAND; ADSORPTION AB Density-functional calculations indicate that the second sphere of coordination around the metal centers of manganese and iron superoxide dismutases (MnSODs and FeSODs) plays an important role in the binding of O-2(-). In these systems, O-2 prefers to bind to Mn or Fe in end-on configurations. For human and E. coli MnSODs, the bound O-2(-) forms hydrogen bonds with tyrosine and glutamine amino acids residues in the second sphere of coordination. In the cases of E. coli and T. elongates FeSODs, hydrogen bonding occurs between the bound O-2(-) and the tyrosine amino acid only because the glutamine is too far away for an effective bonding interaction. The manner in which the O-2(-) binds to the metal center in MnSODs and FeSODs can affect the rate of subsequent protonation and determine the mechanism for the formation of H2O2. Both Mn- and Fe-containing superoxide dismutases contain a metal-bound solvent molecule that has been suggested to be involved in the uptake of a H+ upon reduction of the metal center [Bull, C.; Fee, J. A. J. Anz. Chem. Soc. 1985, 107, 3295; Miller, A.-F.; Padmakumar, K.; Sorkin, D. L.; Karapetian, A.; Vance, C. K. J. Inorg. Biochem. 2003, 93, 71]. Using density-functional theory, we confirm this suggestion and show the involvement of the second sphere of coordination in the process. We show that the oxidation of superoxide by Mn- or Fe-containing superoxide dismutases is facilitated by a cooperative effect between superoxide binding, protonation of the OH- bound to the metal, and electron transfer from the superoxide molecule to the oxidized metal. In particular, proton transfer through tyrosine-34 on the absence of a bound superoxide is uphill while, once superoxide is bound, the energetic barrier is lowered. It is this barrier that likely keeps the resting state (Mn(III)SOD) of the enzyme with a bound hydroxide, instead of a water. This work provides a model for the mechanism of reaction of superoxide with the oxidized form of the metal within Mn- and FeSODs. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov; cabelli@bnl.gov RI Abreu, Isabel/I-5081-2013 OI Abreu, Isabel/0000-0002-5566-2146 FU NIGMS NIH HHS [GM54903] NR 56 TC 17 Z9 17 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 DEC 29 PY 2005 VL 109 IS 51 BP 24502 EP 24509 DI 10.1021/jp052368u PG 8 WC Chemistry, Physical SC Chemistry GA 997PW UT WOS:000234259900041 PM 16375454 ER PT J AU Kanekal, SG Friedel, RHW Reeves, GD Baker, DN Blake, JB AF Kanekal, SG Friedel, RHW Reeves, GD Baker, DN Blake, JB TI Relativistic electron events in 2002: Studies of pitch angle isotropization SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WHISTLER-MODE CHORUS; RADIATION-BELT; ENERGETIC ELECTRONS; INNER MAGNETOSPHERE; RESONANT DIFFUSION; SOLAR-WIND; ACCELERATION; PARTICLE; SAMPEX; STORM AB [1] Energization of electrons to relativistic energies in the Earth's outer radiation belt is not fully understood. Recent renewed interest in the problem has resulted in a number of models which invoke a variety of physical processes ranging from diffusive particle transport to in situ acceleration. Evolution of local pitch angle distributions and global flux isotropization timescales of relativistic electrons may be important discriminators of the underlying physical processes of energization, transport, and loss. Data from SAMPEX, Polar, and LANL suite of satellites were used to study electron isotropization and pitch angle evolution for relativistic electron enhancement events during the year 2002. It was found that during electron energization events there is generally increased precipitation of electrons and rapid electron flux isotropization on a global scale. Case studies using pitch angle resolved data collected at geosynchronous distances suggest an in situ broadening of the local pitch angle distribution in agreement with the corresponding global isotropization measurements. These observations suggest that electron energization in the magnetosphere is intimately associated with rapid pitch angle scattering leading to a flattening of the pitch angle distributions of energized electrons. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Aerosp Corp, Dept Space Sci, Los Angeles, CA 90009 USA. RP Kanekal, SG (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 1234 Innovat Dr,CB 590, Boulder, CO 80303 USA. EM shrikanth.kanekal@noaa.gov RI Friedel, Reiner/D-1410-2012; Reeves, Geoffrey/E-8101-2011 OI Friedel, Reiner/0000-0002-5228-0281; Reeves, Geoffrey/0000-0002-7985-8098 NR 36 TC 15 Z9 15 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 28 PY 2005 VL 110 IS A12 AR A12224 DI 10.1029/2004JA010974 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 001BK UT WOS:000234507300001 ER PT J AU Ketteler, G Ogletree, DF Bluhm, H Liu, HJ Hebenstreit, ELD Salmeron, M AF Ketteler, G Ogletree, DF Bluhm, H Liu, HJ Hebenstreit, ELD Salmeron, M TI In situ spectroscopic study of the oxidation and reduction of Pd(111) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SUBSURFACE OXYGEN; PALLADIUM OXIDE; SURFACE OXIDE; XPS; PHOTOEMISSION; IDENTIFICATION; TEMPERATURE; TRANSITION; PRESSURE; HYDROGEN AB Using a photoemission spectroscometer that operates close to ambient conditions of pressure and temperature we have determined the Pd-O phase diagram and the kinetic parameters of phase transformations. We found that on the (111) surface oxidation proceeds by formation of stable and metastable structures. As the chemical potential of O-2 increases chemisorbed oxygen forms followed by a thin surface oxide. Bulk oxidation is a two-step process that starts with the metastable growth of the surface oxide into the bulk, followed by a first-order transformation to PdO. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM gketteler@lbl.gov NR 35 TC 133 Z9 133 U1 9 U2 83 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 DEC 28 PY 2005 VL 127 IS 51 BP 18269 EP 18273 DI 10.1021/ja055754y PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 997PK UT WOS:000234258700059 PM 16366581 ER PT J AU Bartolo, N Kolb, EW Riotto, A AF Bartolo, N Kolb, EW Riotto, A TI Post-inflation increase of the cosmological tensor-to-scalar perturbation ratio SO MODERN PHYSICS LETTERS A LA English DT Article DE cosmology; inflation; cosmological perturbations ID PROBE WMAP OBSERVATIONS; DENSITY PERTURBATIONS; GRAVITY-WAVES; ANISOTROPY; MAPS; UNIVERSE AB We investigate the possibility that the amplitude of scalar density perturbations may be damped after inflation. This would imply that CMB anisotropies do not uniquely fix the amplitude of the perturbations generated during inflation and that the present tensor-to-scalar ratio might be larger than that produced in inflation, increasing the prospects of detection of primordial gravitational radiation. It turns out, however, that the damping of density perturbations is hard to achieve. C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. Fermilab Natl Accelerator Lab, Ctr Particle Astrophys, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Dept Phys, I-35131 Padua, Italy. RP Bartolo, N (reprint author), Abdus Salam Int Ctr Theoret Phys, Strada Costiera 11, I-34100 Trieste, Italy. EM nbartolo@ictp.trieste.it; rocky@fnal.gov; antonio.riotto@pd.infn.it NR 25 TC 8 Z9 8 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD DEC 28 PY 2005 VL 20 IS 40 BP 3077 EP 3083 DI 10.1142/S0217732305019122 PG 7 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA 000KQ UT WOS:000234460900002 ER PT J AU Alam, TM Cherry, BR Minard, KR Celina, M AF Alam, TM Cherry, BR Minard, KR Celina, M TI Relaxation nuclear magnetic resonance imaging investigation of heterogeneous aging in a hydroxy-terminated polybutadiene-based elastomer SO MACROMOLECULES LA English DT Article ID RESIDUAL DIPOLAR COUPLINGS; RADIOFREQUENCY FIELD GRADIENTS; DIFFUSION-LIMITED OXIDATION; CROSS-LINKED ELASTOMERS; COMPOSITE-MATERIALS; WATER-ABSORPTION; POLYMER NETWORKS; NMR RELAXATION; ROTATING-FRAME; RUBBER AB Relaxation nuclear magnetic resonance imaging (R-NMRI) was employed to investigate the effects of thermooxidative aging in a hydroxy-terminated polybutadiene (HTPB)-based elastomer. A series of three-dimensional (3D) Hahn-echo-weighted single-point images (SPI) of the elastomer were utilized to generate a 3D parameter map of the aged material. NMR spin-spin relaxation times (T-2) were measured for each voxel producing a 3D NMR parameter (T-2) map of the aged polymer. These T-2 maps reveal a dramatic reduction of local polymer mobility near the aging surface with the degree of T-2 heterogeneity varying as a function of aging. Using correlations between NMR T-2 and material modulus, the impact of this heterogeneous thermooxidative aging on the material properties is discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sandia Natl Labs, Albuquerque, NM 87185 USA. EM tmalam@sandia.gov NR 69 TC 6 Z9 6 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD DEC 27 PY 2005 VL 38 IS 26 BP 10694 EP 10701 DI 10.1021/ma051906y PG 8 WC Polymer Science SC Polymer Science GA 996VS UT WOS:000234203900011 ER PT J AU Balooch, G Balooch, M Nalla, RK Schilling, S Filvaroff, EH Marshall, GW Marshall, SJ Ritchie, RO Derynck, R Alliston, T AF Balooch, G Balooch, M Nalla, RK Schilling, S Filvaroff, EH Marshall, GW Marshall, SJ Ritchie, RO Derynck, R Alliston, T TI TGF-beta regulates the mechanical properties and composition of bone matrix SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE osteoblast; Smad3; atomic force microscopy ID TRANSFORMING GROWTH-FACTOR-BETA-1 GENE; OSTEOBLAST DIFFERENTIATION; DEFICIENT MICE; SMAD3; OSTEOCALCIN; EXPRESSION; MASS; OSTEOPOROSIS; INHIBITION; REPRESSION AB The characteristic toughness and strength of bone result from the nature of bone matrix, the mineralized extracellular matrix produced by osteoblasts. The mechanical properties and composition of bone matrix, along with bone mass and architecture, are critical determinants of a bone's ability to resist fracture. Several regulators of bone mass and architecture have been identified, but factors that regulate the mechanical properties and composition of bone matrix are largely unknown. We used a combination of high-resolution approaches, including atomic-force microscopy, x-ray tomography, and Raman microspectroscopy, to assess the properties of bone matrix independently of bone mass and architecture. Properties were evaluated in genetically modified mice with differing levels of TGF-beta signaling. Bone matrix properties correlated with the level of TGF-beta signaling. Smad3+/- mice had increased bone mass and matrix properties, suggesting that the osteopenic Smad3-/- phenotype may be, in part, secondary to systemic effects of Smad3 deletion. Thus, a reduction in TGF-beta signaling, through its effector Smad3, enhanced the mechanical properties and mineral concentration of the bone matrix, as well as the bone mass, enabling the bone to better resist fracture. Our results provide evidence that bone matrix properties are controlled by growth factor signaling. C1 Univ Calif San Francisco, Grad Program Oral & Craniofacial Sci, Dept Prevent & Restorat Dent Sci, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Cell & Tissue Biol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Program Cell Biol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Program Dev, San Francisco, CA 94143 USA. Univ Calif Berkeley, Div Mat Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Duke Univ, Dept Pharmacol & Canc Biol, Durham, NC 27710 USA. Genentech Inc, Dept Mol Oncol, San Francisco, CA 94080 USA. RP Derynck, R (reprint author), Univ Calif San Francisco, Grad Program Oral & Craniofacial Sci, Dept Prevent & Restorat Dent Sci, San Francisco, CA 94143 USA. EM derynck@itsa.ucsf.edu; tamara.alliston@ucsf.edu RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 34 TC 121 Z9 132 U1 2 U2 21 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 DEC 27 PY 2005 VL 102 IS 52 BP 18813 EP 18818 DI 10.1073/pnas.0507417102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 998WG UT WOS:000234350000009 PM 16354837 ER PT J AU Brown, JH Zhou, ZC Reshetnikova, L Robinson, H Yammani, RD Tobacman, LS Cohen, C AF Brown, JH Zhou, ZC Reshetnikova, L Robinson, H Yammani, RD Tobacman, LS Cohen, C TI Structure of the mid-region of tropomyosin: Bending and binding sites for actin SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE alanine; alpha-helix; cardiomyopathy; coiled coil; packing ID MUSCLE THIN-FILAMENTS; HELICAL COILED-COILS; FAMILIAL HYPERTROPHIC CARDIOMYOPATHY; RAY FIBER DIFFRACTION; ALPHA-TROPOMYOSIN; CRYSTAL-STRUCTURE; ATOMIC MODEL; SKELETAL-MUSCLE; TROPONIN-T; F-ACTIN AB Tropomyosin is a two-chain a-helical coiled coil whose periodic interactions with the F-actin helix are critical for thin filament stabilization and the regulation of muscle contraction. Here we deduce the mechanical and chemical basis of these interactions from the 2.3-angstrom-resolution crystal structure of the middle three of tropomyosin's seven periods. Geometrically specific bends of the coiled coil, produced by clusters of core alanines, and variable bends about gaps in the core, produced by isolated alanines, occur along the molecule. The crystal packing is notable in signifying that the functionally important fifth period includes an especially favorable protein-binding site, comprising an unusual apolar patch on the surface together with surrounding charged residues. Based on these and other results, we have constructed a specific model of the thin filament, with the N-terminal halves of each period (i.e., the so-called "alpha zones") of tropomyosin axially aligned with subdomain 3 of each monomer in F-actin. C1 Brandeis Univ, Rosenstiel Basic Med Sci Res Ctr, Waltham, MA 02454 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Univ Illinois, Coll Med, Dept Physiol & Biophys, Chicago, IL 60612 USA. RP Cohen, C (reprint author), Brandeis Univ, Rosenstiel Basic Med Sci Res Ctr, Waltham, MA 02454 USA. EM ccohen@brandeis.edu FU NHLBI NIH HHS [HL38834, R01 HL038834]; NIAMS NIH HHS [AR017346, R01 AR017346, R37 AR017346] NR 56 TC 93 Z9 93 U1 1 U2 6 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 27 PY 2005 VL 102 IS 52 BP 18878 EP 18883 DI 10.1073/pnas.0509269102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 998WG UT WOS:000234350000020 PM 16365313 ER PT J AU Adhikari, H McIntyre, PC Sun, SY Pianetta, P Chidsey, CED AF Adhikari, H McIntyre, PC Sun, SY Pianetta, P Chidsey, CED TI Photoemission studies of passivation of germanium nanowires SO APPLIED PHYSICS LETTERS LA English DT Article ID CORE-LEVEL SHIFTS; SURFACE; GE(100); GE(111) AB The surface of single crystal germanium nanowires grown by cold-wall chemical vapor deposition was studied by synchrotron radiation photoemission spectroscopy and also by conventional x-ray photoelectron spectroscopy. The surfaces of the nanowires are not oxidized from which we infer that they are hydrogen passivated as-grown. Exposure to laboratory atmosphere leads to germanium oxide growth with oxidation states of Ge1+, Ge2+, Ge3+, while exposure to UV light leads to a predominance of the Ge4+ oxidation state. Most of the surface oxide could be removed readily by aqueous HF treatment which presumably leaves the nanowire surface hydrogen terminated. The HF-treated surface has more limited stability in air. Alternatively, chlorine termination could be achieved by aqueous HCl treatment of the oxide-coated nanowires. This chlorine termination was found to be more stable in air than the putative hydrogen termination achieved by aqueous HF treatment. (c) 2005 American Institute of Physics. C1 Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Chidsey, CED (reprint author), Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. EM chidsey@stanford.edu NR 14 TC 43 Z9 44 U1 0 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 26 PY 2005 VL 87 IS 26 AR 263109 DI 10.1063/1.2158027 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700081 ER PT J AU Fu, LF Welz, SJ Browning, ND Kurasawa, M McIntyre, PC AF Fu, LF Welz, SJ Browning, ND Kurasawa, M McIntyre, PC TI Z-contrast and electron energy loss spectroscopy study of passive layer formation at ferroelectric PbTiO3/Pt interfaces SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY-ABSORPTION; THIN-FILMS AB Scanning transmission electron microscopy and electron energy loss spectroscopy have been applied to investigate the possible structural origins of ferroelectric polarization degradation at PbTiO3/Pt interfaces. The microscopic analysis revealed that an amorphous Ti-rich interfacial layer as well as nanometer size precipitates was formed at PbTiO3/Pt interfaces. The interfacial layer appears to form through decomposition of the PbTiO3 film due to a ferroelectric-electrode reaction during Pt deposition. The formation of the interfacial layer and precipitates could contribute to the polarization degradation typically observed for Pt-electroded PbTiO3-based ferroelectric capacitors. (c) 2005 American Institute of Physics. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. RP Fu, LF (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. EM lffu@lbl.gov NR 13 TC 11 Z9 11 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 DEC 26 PY 2005 VL 87 IS 26 AR 262904 DI 10.1063/1.2144279 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700067 ER PT J AU Lee, B Wang, LW AF Lee, B Wang, LW TI Electronic structure of calcium hexaborides SO APPLIED PHYSICS LETTERS LA English DT Article ID BAND-STRUCTURE; DENSITY; CAB6; FERROMAGNETISM; EXCHANGE AB We present a theoretical study of crystal and electronic structures of CaB(6) within a screened-exchange local density approximation (sX-LDA). Our ab initio total energy calculations show that CaB(6) is a semiconductor with a gap of > 1.2 eV, in agreement with recent experimental observations. We show a very sensitive band-gap dependence on the crystal internal parameter, which might partially explain the scatter of previous theoretical results. Our calculation demonstrates that it is essential to study this system simultaneously for both crystal structures and electronic properties, and that the sX-LDA provides an ideal method for this problem. (c) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Comp Res Div, Berkeley, CA 94720 USA. RP Lee, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Comp Res Div, Berkeley, CA 94720 USA. EM bhlee@lbl.gov NR 21 TC 25 Z9 26 U1 0 U2 12 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 26 PY 2005 VL 87 IS 26 AR 262509 DI 10.1063/1.2150578 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700062 ER PT J AU Schlichenmaier, C Thranhardt, A Meier, T Koch, SW Chow, WW Hader, J Moloney, JV AF Schlichenmaier, C Thranhardt, A Meier, T Koch, SW Chow, WW Hader, J Moloney, JV TI Gain and carrier losses of (GaIn)(NAs) heterostructures in the 1300-1550 nm range SO APPLIED PHYSICS LETTERS LA English DT Article ID FEEDBACK LASER-DIODES; QUANTUM-WELL LASERS; MU-M; SEMICONDUCTOR-LASERS; SPONTANEOUS EMISSION; ALLOYS AB A microscopic model is used to analyze gain and loss properties of (GaIn)(NAs)/GaAs quantum wells in the 1.3-1.55 mu m range, including Auger and radiative recombination. The calculations show that, as long as good material quality can be achieved, growing highly compressively strained samples is preferable due to their specific band structure properties. Optimum laser operation is possible slightly above a peak gain of 1000 cm(-1). (c) 2005 American Institute of Physics. C1 Univ Marburg, Fachbereich Phys, D-35032 Marburg, Germany. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. RP Schlichenmaier, C (reprint author), Univ Marburg, Fachbereich Phys, Renthof 5, D-35032 Marburg, Germany. EM christoph.schlichenmaier@physik.uni-marburg.de RI Thranhardt, Angela/A-5888-2013 NR 21 TC 6 Z9 6 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 DEC 26 PY 2005 VL 87 IS 26 AR 261109 DI 10.1063/1.2149371 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700009 ER PT J AU Thomas, L Rettner, C Hayashi, M Samant, MG Parkin, SSP Doran, A Scholl, A AF Thomas, L Rettner, C Hayashi, M Samant, MG Parkin, SSP Doran, A Scholl, A TI Observation of injection and pinning of domain walls in magnetic nanowires using photoemission electron microscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID WIRES AB Photoemission electron microscopy is used to explore the injection and pinning of magnetic domain walls in 250-nm-wide, 20-nm-thick Permalloy nanowires. Domain walls are injected from a micron-sized elliptical nucleation pad at one end of the nanowire. A vortex-like structure is readily nucleated in this pad at low magnetic fields (< 15 Oe), whereas injection of a domain wall into the nanowire requires significantly larger fields (similar to 60 Oe). Domain walls are pinned in the nanowire at notches patterned along the wire's edges. The domain walls are observed to have vortex-like structures with chiralities that vary in successive experiments. (c) 2005 American Institute of Physics. C1 IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Thomas, L (reprint author), IBM Corp, Almaden Res Ctr, 650 Harry Rd, San Jose, CA 95120 USA. EM lucthom@us.ibm.com RI Parkin, Stuart/D-2521-2012; Hayashi, Masamitsu/H-2809-2011 OI Hayashi, Masamitsu/0000-0003-2134-2563 NR 12 TC 33 Z9 33 U1 0 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 26 PY 2005 VL 87 IS 26 AR 262501 DI 10.1063/1.2139842 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700054 ER PT J AU Troparevsky, MC Franceschetti, A AF Troparevsky, MC Franceschetti, A TI Radiative recombination of charged excitons and multiexcitons in CdSe quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article ID SEMICONDUCTOR NANOCRYSTALS AB We report semi-empirical pseudopotential calculations of emission spectra of charged excitons and biexcitons in CdSe nanocrystals. We find that the main emission peak of charged multiexcitons-originating from the recombination of an electron in an s-like state with a hole in an s-like state-is blueshifted with respect to the neutral monoexciton. In the case of the negatively charged biexciton, we observe additional emission peaks of lower intensity at higher energy, which we attribute to the recombination of an electron in a p state with a hole in a p state. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. EM troparevskym@ornl.gov NR 15 TC 12 Z9 12 U1 0 U2 5 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 DEC 26 PY 2005 VL 87 IS 26 AR 263115 DI 10.1063/1.2150583 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700087 ER PT J AU Xu, ZH Wu, Y Hu, B Ivanov, IN Geohegan, DB AF Xu, ZH Wu, Y Hu, B Ivanov, IN Geohegan, DB TI Carbon nanotube effects on electroluminescence and photovoltaic response in conjugated polymers SO APPLIED PHYSICS LETTERS LA English DT Article ID LIGHT-EMITTING-DIODES; POLY(P-PHENYLENE VINYLENE); COMPOSITE; DEVICES; DYNAMICS AB This letter reports the experimental results of enhanced electroluminescence (EL) and photovoltaic (PV) response upon doping single-wall carbon nanotubes (SWNTs) into conjugated polymer poly[2-methoxy-5-(2(')-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) based on single-layer light-emitting diodes. We found that the dispersed SWNTs result in two processes: charge transport and exciton dissociation at the tube-chain interface in the SWNT/polymer composites. The detailed EL and PV studies indicate that low SWNT doping concentrations mainly improve the bipolar charge injection, leading to enhanced both reverse and forward EL with reduced threshold voltage. As the SWNT doping concentration continues to increase, the interfacial exciton dissociation becomes dominated, giving rise to an increased PV response. This SWNT concentration-dependent charge transport and exciton dissociation present a pathway to individually address the dual EL and PV functionalities of SWNT-doped polymer composites by controlling the doping level of the SWNTs. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Hu, B (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. EM bhu@utk.edu RI Xu, Zhihua/G-3956-2011; Hu, Bin/A-2954-2015; ivanov, ilia/D-3402-2015; Geohegan, David/D-3599-2013 OI Hu, Bin/0000-0002-1573-7625; ivanov, ilia/0000-0002-6726-2502; Geohegan, David/0000-0003-0273-3139 NR 21 TC 41 Z9 41 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 DEC 26 PY 2005 VL 87 IS 26 AR 263118 DI 10.1063/1.2152113 PG 3 WC Physics, Applied SC Physics GA 998SD UT WOS:000234338700090 ER PT J AU Sarangi, R Benfatto, M Hayakawa, K Bubacco, L Solomon, EI Hodgson, KO Hedman, B AF Sarangi, R Benfatto, M Hayakawa, K Bubacco, L Solomon, EI Hodgson, KO Hedman, B TI MXAN analysis of the XANES energy region of a mononuclear copper complex: Applications to bioinorganic systems SO INORGANIC CHEMISTRY LA English DT Article ID X-RAY-ABSORPTION; CYTOCHROME-C-OXIDASE; FINE-STRUCTURE; 2.8 ANGSTROM; SPECTRA; HEME; SITE; SUPERFAMILY; NUMBER AB The near edge XAS spectra of the mononuclear copper complex [Cu(TMPA)(OH2)](CIO4)(2) (1) have been simulated using the multiple scattering edge simulation package MXAN (or Minuit XANes). These simulations, which employ the muffin-tin (MT) approximation, have been compared to simulations generated using the finite-difference method (FDM) to evaluate the effect of MT corrections. The sensitivity of the MXAN method was tested using structural models that included several different variations on the bond angles and bond distances for the first-shell atoms of 1. The sensitivity to small structural changes was also evaluated by comparing MXAN simulations of 1 and of structurally modified [Cu(TMPA)(L)](n+) complexes [where L = -O-(F8TPP)Fe-III, -F, -OPO2(O-p-nitrophenyl)Zn-II-(TMPA), and -NCMe] to the experimental data. The accuracy of the bond distances obtained from the MXAN simulations was then examined by comparison to the metrics of the crystal structures. The results show that MXAN can successfully extract geometric information from the edge structure of an XAS spectrum. The systematic application of MXAN to 1 indicates that this approach is sensitive to small structural changes in the molecule that are manifested in the XAS edge spectrum, These results represent the first step toward the application of this methodology to bioinorganic and biological systems. C1 Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Padua, Dipartimento Biol, I-30121 Padua, Italy. Stanford Univ, Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. RP Ist Nazl Fis Nucl, Lab Nazl Frascati, CP 13, I-00044 Frascati, Italy. EM Maurizio.Benfatto@lnf.infn.it RI Bubacco, Luigi/B-5602-2012; OI Bubacco, Luigi/0000-0001-7927-9208 FU NCRR NIH HHS [RR-01209]; NIDDK NIH HHS [DK31450] NR 44 TC 12 Z9 12 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD DEC 26 PY 2005 VL 44 IS 26 BP 9652 EP 9659 DI 10.1021/ic050703n PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 996RO UT WOS:000234192300017 PM 16363833 ER PT J AU Contel, M Villuendas, PR Fernandez-Gallardo, J Alonso, PJ Vincent, JM Fish, RH AF Contel, M Villuendas, PR Fernandez-Gallardo, J Alonso, PJ Vincent, JM Fish, RH TI Fluorocarbon soluble copper(II) carboxylate complexes with nonfluoroponytailed nitrogen ligands as precatalysts for the oxidation of alkenols and alcohols under fluorous biphasic or thermomorphic modes: Structural and mechanistic aspects SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; PHASE-SEPARATION; CATALYSIS; DIMER; ACID; N,N-DIMETHYLFORMAMIDE; INDOMETHACIN; CHEMISTRY; SOLVENTS; OLEFINS AB This fluorous biphasic catalysis (FBC) contribution was focused on the synthesis and characterization of new fluorous soluble Rf-Cu(II) carboxylate complexes containing nonfluoroponytailed ligands and defines their role as precatalysts for the FBC oxidation of alkenols and alcohols in the presence of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)/O-2. In this FBC approach, we have utilized the phase-switching technique of Vincent et al. (J. Am. Chem. Soc. 2002, 124, 12942) to solubilize the nonfluoroponytailed ligands, N-1,4,7-Me(3)TACN, 2, and N-1,4,7-pentamethyldiethylenetriamine (PMDETA), 3, by reaction with a fluorous solvent-soluble copper (II) dimeric complex, [CU({C8F17(CH2)(2)}(2)-CHCO2)(2)}(2), 1. Moreover, the reaction of nonfluoroponytailed ligands 2 and 3 with 1 afforded new perfluoroheptane-soluble Cu(II) complexes, [Cu({C8F17(CH2)(2)}(2)CHCO2)(2)(2)], 4, and [Cu({C8F17(CH2)(2)}(2)CHCO2)(2) (3)], 5, respectively. The known Cu(II) complex, 1, was further characterized by electron paramagnetic resonance (EPR) spectroscopy confirming its dimeric structure, while 4 and 5 were characterized by elemental analysis, IR, diffuse reflectance UV-vis, and EPR spectroscopy. Furthermore, 1, 4, and 5 were evaluated as precatalysts for alkenol and alcohol oxidation. The oxidation reactions of alkenols and alcohols in the presence of TEMPO/O-2 proceeded under FBC conditions for 1, 4, and 5, but 1-octanol was unreactive under single-phase FBC conditions at 90 degrees C with TEMPO/O-2. The thermomorphic property of 5, soluble in chlorobenzene/toluene at 90 degrees C but insoluble at room temperature, was also evaluated in the selective oxidation of p-nitrobenzyl alcohol to p-nitrobenzaldehyde. Plausible mechanisms concerning these FBC/thermomorphic oxidation reactions will be discussed. C1 Univ Zaragoza, CSIC, Dept Quim Inorgan, E-50009 Zaragoza, Spain. Univ Zaragoza, CSIC, Dept Fis Mat Condensada, Inst Ciencia Mat Aragon,Fac Ciencias, E-50009 Zaragoza, Spain. Univ Bordeaux 1, CNRS, UMR 5802, Chim Organ & Organomet Lab, F-33405 Talence, France. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Vincent, JM (reprint author), Univ Zaragoza, CSIC, Dept Quim Inorgan, E-50009 Zaragoza, Spain. EM jm.vincent@lcoo.u-bordeaux1.fr; rhfish@lbl.gov RI Fernandez-Gallardo Jimenez, Jacob/B-7626-2011; Alonso, Pablo/L-2759-2014 OI Fernandez-Gallardo Jimenez, Jacob/0000-0002-1096-8192; Alonso, Pablo/0000-0003-3449-4929 NR 46 TC 39 Z9 39 U1 2 U2 14 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 DEC 26 PY 2005 VL 44 IS 26 BP 9771 EP 9778 DI 10.1021/ic051220m PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 996RO UT WOS:000234192300030 PM 16363846 ER PT J AU Kang, QJ Zhang, DX Chen, SY AF Kang, QJ Zhang, DX Chen, SY TI Displacement of a three-dimensional immiscible droplet in a duct SO JOURNAL OF FLUID MECHANICS LA English DT Article ID LATTICE-BOLTZMANN MODEL; MOVING CONTACT LINES; RAYLEIGH-TAYLOR INSTABILITY; PRESSURE-DRIVEN FLOWS; FLUID INTERFACE; MULTIPHASE FLOWS; SOLID-SURFACE; ROUGH-SURFACE; DYNAMICS; SIMULATION AB The displacement of a three-dimensional immiscible droplet subject to gravitational forces in a duct is studied with the lattice Boltzmann method. The effects of the contact angle and capillary number (the ratio of viscous to surface forces) on droplet dynamics are investigated. It is found that there exists a critical capillary number for a droplet with a given contact angle. When the actual capillary number is smaller than the critical value, the droplet moves along the wall and reaches a steady state. When the capillary number is greater than the critical value, one or more small droplets pinch off from the wall or from the rest of the droplet, depending on the contact angle and the specific value of the capillary number. As the downstream part of the droplet is pinching off, a bottleneck forms and its area continues decreasing until reaching zero. The general trend found in a previous two-dimensional study that the critical capillary number decreases as the contact angle increases is confirmed. It is shown that at a fixed capillary number above the critical value, increasing the contact angle results in a larger first-detached portion. At a fixed contact angle, increasing the capillary number results in an increase of the size of the first detached droplet for theta = 78 degrees and theta = 90 degrees, but a decrease for theta = 118 degrees. It is also found that the droplet is stretched longer as the capillary number becomes larger. For a detaching droplet, the maximal velocity value occurs near the bottleneck between the up- and downstream parts of the droplet and the shear stress there reaches a local maximum. The three-dimensional effects are most clearly seen for theta = 90 degrees, where the wetted length and wetted area vary in the opposite direction and the shape of the interface between the wall and the droplet is distorted severely from the original round shape. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Oklahoma, Norman, OK 73019 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Peking Univ, Beijing 100871, Peoples R China. RP Kang, QJ (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Zhang, Dongxiao/D-5289-2009; Chen, Shiyi/A-3234-2010; Kang, Qinjun/A-2585-2010 OI Zhang, Dongxiao/0000-0001-6930-5994; Kang, Qinjun/0000-0002-4754-2240 NR 35 TC 64 Z9 64 U1 2 U2 24 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD DEC 25 PY 2005 VL 545 BP 41 EP 66 DI 10.1017/S0022112005006956 PG 26 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 998FN UT WOS:000234304100003 ER PT J AU Sato, R Sakamoto, T Kataoka, J Yoshida, A Suzuki, M Kotoku, J Urata, Y Yamamoto, Y Arimoto, M Tamagawa, T Shirasaki, Y Torii, K Matsuoka, M Nakagawa, Y Yamazaki, T Tanaka, K Maetou, M Yamauchi, M Takagishi, K Lamb, DQ Atteia, JL Vanderspek, R Graziani, C Prigozhin, G Villasenor, J Jernigan, JG Crew, GB Hurley, K Ricker, GR Woosley, SE Butler, N Levine, A Doty, JP Donaghy, TQ Fenimore, EE Galassi, M Boer, M Dezalay, JP Olive, JF Braga, J Manchanda, R Pizzichini, G Kawai, N AF Sato, R Sakamoto, T Kataoka, J Yoshida, A Suzuki, M Kotoku, J Urata, Y Yamamoto, Y Arimoto, M Tamagawa, T Shirasaki, Y Torii, K Matsuoka, M Nakagawa, Y Yamazaki, T Tanaka, K Maetou, M Yamauchi, M Takagishi, K Lamb, DQ Atteia, JL Vanderspek, R Graziani, C Prigozhin, G Villasenor, J Jernigan, JG Crew, GB Hurley, K Ricker, GR Woosley, SE Butler, N Levine, A Doty, JP Donaghy, TQ Fenimore, EE Galassi, M Boer, M Dezalay, JP Olive, JF Braga, J Manchanda, R Pizzichini, G Kawai, N TI HETE-2 localization and observations of the gamma-ray burst GRB 020813 SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE gamma-rays : bursts ID MAGNETIC-FIELDS; ENERGY; MODEL; EMISSION; SHOCK; AFTERGLOW; PROMPT AB A bright, long gamma-ray burst (GRB) was detected and localized by the instruments on board the High Energy Transient Explorer 2 satellite (HETE-2) at 02:44:19.17 UTC (9859.17 s UT) on 2002 August 13. The location was reported to the GRB Coordinates Network (GCN) about 4 min after the burst. In the prompt emission, the burst had a duration of approximately 125 s, and more than four peaks. We analyzed the time-resolved 2-400 keV energy spectra of the prompt emission of GRB 020813 using the Wide Field X-Ray Monitor (WXM) and the French Gamma Telescope (FREGATE) in detail. We found that the early part of the burst (17-52 s after the burst trigger) shows a depletion of low-energy photons below about 50 keV. It is difficult to explain the depletion by either synchrotron self-absorption or Comptonization. One possibility is that the low-energy depletion may be understood as a mixture of "jitter" radiation with the usual synchrotron radiation component. C1 Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RIKEN, Wako, Saitama 3510198, Japan. Aoyama Gakuin Univ, Dept Phys, Sagamihara, Kanagawa 2298558, Japan. Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Toyonaka, Osaka 5600043, Japan. JAXA, Tsukuba, Ibaraki 3048505, Japan. Miyazaki Univ, Fac Engn, Miyazaki, Miyazaki 8992192, Japan. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France. MIT, CSR, Cambridge, MA 02139 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, Brazil. Tata Inst Fundamental Res, Dept Astron & Astrophys, Bombay 400005, Maharashtra, India. INAF, IASF, Sez Bologna, I-40129 Bologna, Italy. RP Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. EM rsato@hp.phys.titech.ac.jp OI Boer, Michel/0000-0001-9157-4349 NR 27 TC 4 Z9 4 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD DEC 25 PY 2005 VL 57 IS 6 BP 1031 EP 1039 DI 10.1093/pasj/57.6.1031 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 002JF UT WOS:000234607000016 ER PT J AU Ye, M Neuman, SP Meyer, PD Pohlmann, K AF Ye, M Neuman, SP Meyer, PD Pohlmann, K TI Sensitivity analysis and assessment of prior model probabilities in MLBMA with application to unsaturated fractured tuff SO WATER RESOURCES RESEARCH LA English DT Article ID SPATIAL COVARIANCE-STRUCTURES; LIKELIHOOD CROSS VALIDATION; STEADY-STATE CONDITIONS; MATHEMATICAL-THEORY; AQUIFER PARAMETERS; PRIOR INFORMATION; GRAPHICAL MODELS; UNCERTAINTY; COMMUNICATION; PERFORMANCE AB [1] Previous application of maximum likelihood Bayesian model averaging (MLBMA, Neuman ( 2002, 2003)) to alternative variogram models of log air permeability data in fractured tuff has demonstrated its effectiveness in quantifying conceptual model uncertainty and enhancing predictive capability ( Ye et al., 2004). A question remained how best to ascribe prior probabilities to competing models. In this paper we examine the extent to which lead statistics of posterior log permeability predictions are sensitive to prior probabilities of seven corresponding variogram models. We then explore the feasibility of quantifying prior model probabilities by ( 1) maximizing Shannon's entropy H ( Shannon, 1948) subject to constraints reflecting a single analyst's ( or a group of analysts') prior perception about how plausible each alternative model ( or a group of models) is relative to others, and ( 2) selecting a posteriori the most likely among such maxima corresponding to alternative prior perceptions of various analysts or groups of analysts. Another way to select among alternative prior model probability sets, which, however, is not guaranteed to yield optimum predictive performance ( though it did so in our example) and would therefore not be our preferred option, is a minimum-maximum approach according to which one selects a priori the set corresponding to the smallest value of maximum entropy. Whereas maximizing H subject to the prior perception of a single analyst ( or group) maximizes the potential for further information gain through conditioning, selecting the smallest among such maxima gives preference to the most informed prior perception among those of several analysts ( or groups). We use the same variogram models and log permeability data as Ye et al. ( 2004) to demonstrate that our proposed approach yields the least amount of posterior entropy ( residual uncertainty after conditioning) and enhances predictive model performance as compared to ( 1) the noninformative neutral case in which all prior model probabilities are set equal to each other and ( 2) an informed case that nevertheless violates the principle of parsimony. C1 Desert Res Inst, Las Vegas, NV 89119 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Ye, M (reprint author), Desert Res Inst, 755 E Flamingo Rd, Las Vegas, NV 89119 USA. EM neuman@hwr.arizona.edu RI Ye, Ming/A-5964-2008 NR 37 TC 41 Z9 41 U1 2 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC 24 PY 2005 VL 41 IS 12 AR W12429 DI 10.1029/2005WR004260 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 999EE UT WOS:000234370800004 ER PT J AU Im, HK Stein, ML Kotamarthi, VR AF Im, HK Stein, ML Kotamarthi, VR TI A new approach to scenario analysis using simplified chemical transport models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AMMONIA EMISSIONS; AIR-POLLUTION; US CITIES; MORTALITY AB [1] Given the computational burden of running full chemical transport models, it is highly desirable to have alternative ways to obtain fast and accurate approximations to at least some of these model outputs. We propose two methods that closely approximate the ammonia wet deposition of the Community Multiscale Air Quality (CMAQ) model, a regional-scale three-dimensional chemical transport model. The first method uses a greatly simplified version of CMAQ, called here "Tracer,'' which requires one fortieth the processing time of CMAQ. The second method uses an extension of the Tracer model called "Multitracer.'' Both methods make use of a CMAQ run under a reference emission scenario and are shown to provide good approximations to CMAQ outputs under different emission scenarios. The first fast approximation method proposed here requires a Tracer run under the new emission scenario while the second proposed approximation only requires a matrix multiplication between a precomputed matrix that approximates the transport in the model, obtained from a single Multitracer run, and the new emission. It will be shown that this method is not a simple source- receptor approximation of the model. As an important application of the second predictor, we propose an inverse modeling method for ammonia that makes it possible to adjust emissions by a different factor for each of the 100 subregions of the spatial domain. Testing with pseudodata yields a good match between the inverse modeled emissions and the actual emissions. Estimates of emissions using actual observations in the eastern United States show a reasonable adjustment field. C1 Univ Chicago, Dept Stat, Chicago, IL 60637 USA. Argonne Natl Lab, Div Environm Res, Atmospher Res Sect, Argonne, IL 60437 USA. RP Im, HK (reprint author), Univ Chicago, Dept Stat, 5734 S Univ Ave, Chicago, IL 60637 USA. EM haky@galton.uchicago.edu; stein@galton.uchicago.edu; vrkotamarthi@anl.gov OI Im, Hae Kyung/0000-0003-0333-5685; Kotamarthi, Veerabhadra Rao/0000-0002-2612-7590 NR 23 TC 1 Z9 1 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 23 PY 2005 VL 110 IS D24 AR D24205 DI 10.1029/2005JD006417 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 999CB UT WOS:000234365200011 ER PT J AU Zaveri, RA Easter, RC Peters, LK AF Zaveri, RA Easter, RC Peters, LK TI A computationally efficient multicomponent equilibrium solver for aerosols (MESA) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AQUEOUS-PHASE-TRANSITIONS; ELECTROLYTE-SOLUTIONS; ATMOSPHERIC AEROSOLS; THERMODYNAMIC MODEL; WATER ACTIVITIES; AMMONIUM; MICROPARTICLES; EQUATIONS; NITRATE; NONEQUILIBRIUM AB [1] Development and application of a new Multicomponent Equilibrium Solver for Aerosols ( MESA) is described for systems containing H+, NH4+, Na+, Ca2+, SO42-, HSO4-, NO3-, and Cl- ions. The equilibrium solution is obtained by integrating a set of pseudo-transient ordinary differential equations describing the precipitation and dissolution reactions for all the possible salts to steady state. A comprehensive temperature dependent mutual deliquescence relative humidity (MDRH) parameterization is developed for all the possible salt mixtures, thereby eliminating the need for a rigorous numerical solution when ambient RH is less than MDRH( T). The solver is unconditionally stable, mass conserving, and shows robust convergence. Performance of MESA was evaluated against the Web-based AIM Model III, which served as a benchmark for accuracy, and the EQUISOLV II solver for speed. Important differences in the convergence and thermodynamic errors in MESA and EQUISOLV II are discussed. The average ratios of speeds of MESA over EQUISOLV II ranged between 1.4 and 5.8, with minimum and maximum ratios of 0.6 and 17, respectively. Because MESA directly diagnoses MDRH, it is significantly more efficient when RH < MDRH. MESA's superior performance is partially due to its "hard-wired'' code for the present system as opposed to EQUISOLV II, which has a more generalized structure for solving any number and type of reactions at temperatures down to 190 K. These considerations suggest that MESA is highly attractive for use in 3-D aerosol/air-quality models for lower tropospheric applications ( T > 240 K) in which both accuracy and computational efficiency are critical. C1 Pacific NW Natl Lab, Atmospher Sci & Global Change Div, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Atmospher Sci & Global Change Div, MSIN K9-30,POB 999, Richland, WA 99352 USA. EM rahul.zaveri@pnl.gov; richard.easter@pnl.gov; len.peters@pnl.gov OI Zaveri, Rahul/0000-0001-9874-8807 NR 47 TC 64 Z9 66 U1 3 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 23 PY 2005 VL 110 IS D24 AR D24203 DI 10.1029/2004JD005618 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 999CB UT WOS:000234365200001 ER PT J AU Hellinger, P Velli, M Travnicek, P Gary, SP Goldstein, BE Liewer, PC AF Hellinger, P Velli, M Travnicek, P Gary, SP Goldstein, BE Liewer, PC TI Alfven wave heating of heavy ions in the expanding solar wind: Hybrid simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ALFVEN/CYCLOTRON FLUCTUATIONS; VELOCITY DISTRIBUTIONS; CYCLOTRON WAVES; CORONAL HOLES; ACCELERATION; ANISOTROPY; DIFFUSION; RESONANCE; SPECTRA; PROTONS AB [1] We present hybrid expanding box simulations of the interaction of left-handed Alfven waves with protons, alpha particles, and a tenuous population of oxygen O5+. The Alfven waves are initially nonresonant with the ions, and the expansion brings them to the cyclotron resonance with O5+ ions, then with alpha particles, and finally with protons. The simulations show that O5+ ions are efficiently heated in the directions perpendicular to the background magnetic field but are only slightly accelerated. Oxygen scattering has a finite time span and saturates mainly due to the marginal stabilization with respect to the oxygen cyclotron instability generated by the temperature anisotropy. During the scattering, oxygen ions are able to absorb only a limited amount of available fluctuating energy and, for the parameters used in the simulations, their presence has a minimum influence on alpha particles and protons. C1 Acad Sci Czech Republic, Inst Atmospher Phys, Prague 14131, Czech Republic. Univ Florence, Dept Astron & Space Sci, I-50125 Florence, Italy. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Acad Sci Czech Republic, Inst Atmospher Phys, Prague 14131, Czech Republic. EM petr.hellinger@ufa.cas.cz; velli@arcetri.astro.it; trav@ufa.cas.cz; pgary@lanl.gov; bruce.goldstein@jpl.nasa.gov; paulett.liewer@jpl.nasa.gov RI Hellinger, Petr/F-5267-2014; Travnicek, Pavel/G-8608-2014 OI Hellinger, Petr/0000-0002-5608-0834; NR 27 TC 37 Z9 37 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 23 PY 2005 VL 110 IS A12 AR A12109 DI 10.1029/2005JA011244 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 999DJ UT WOS:000234368600002 ER PT J AU Hallman, T AF Hallman, T TI Highlighting the STAR collaboration SO SCIENCE LA English DT Letter C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Hallman, T (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 23 PY 2005 VL 310 IS 5756 BP 1904 EP 1904 DI 10.1126/science.310.5756.1904 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 997UX UT WOS:000234275400023 PM 16373560 ER PT J AU Hayton, TW Boncella, JM Scott, BL Palmer, PD Batista, ER Hay, PJ AF Hayton, TW Boncella, JM Scott, BL Palmer, PD Batista, ER Hay, PJ TI Synthesis of imido analogs of the uranyl ion SO SCIENCE LA English DT Article ID ELECTRONIC-STRUCTURE; COMPLEXES; ACTINIDES; CHEMISTRY; URANIUM; ROUTE; METAL AB Here we describe the synthesis of two imido analogs of the uranyl ion, UO22+, in which the oxygens are replaced by divalent alkyi or aryl nitrogen groups: U((NBu)-Bu-t)(2)I-2(THF)(2) (1) and U(NPh)(2)I-2(THF)(3) (2) (where Bu-t is tert-butyl and THF is tetrahydrofuran). Both compounds have been fully characterized by standard analytical techniques, including x-ray crystallography, and the chemical bonding between the metal center and the nitrogen ligands was quantified by using hybrid density functional theory calculations. As expected for a uranyl analog, these complexes exhibit linear N-U-N linkages and very short U-N bonds. In addition, the theoretical calculations show strong involvement of the 5f and 6d electrons in the U-N bonding. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Boncella, JM (reprint author), Los Alamos Natl Lab, Div Chem, MS J514, Los Alamos, NM 87545 USA. EM boncella@lanl.gov RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 24 TC 138 Z9 139 U1 0 U2 20 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 23 PY 2005 VL 310 IS 5756 BP 1941 EP 1943 DI 10.1126/science.1120069 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 997UX UT WOS:000234275400038 PM 16373571 ER PT J AU De Lorenzi-Venneri, G Wallace, DC AF De Lorenzi-Venneri, G Wallace, DC TI A model for transits in dynamic response theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SIMPLE CLASSICAL LIQUIDS; LENNARD-JONES MIXTURE; DENSITY-FLUCTUATIONS; COUPLING THEORY; RELAXATION PROCESSES; MONATOMIC LIQUIDS; MOLECULAR-DYNAMICS; GLASS-TRANSITION; SELF-DIFFUSION; RUBIDIUM AB The first goal of vibration-transit (V-T) theory was to construct a tractable approximate Hamiltonian from which the equilibrium thermodynamic properties of monatomic liquids can be calculated. The Hamiltonian for vibrations in an infinitely extended harmonic random valley, together with the universal multiplicity of such valleys, gives an accurate first-principles account of the measured thermodynamic properties of the elemental liquids at melt. In the present paper, V-T theory is extended to nonequilibrium properties, through an application to the dynamic structure factor S(q,omega). It was previously shown that the vibrational contribution alone accurately accounts for the Brillouin peak dispersion curve for liquid sodium, as compared both with molecular-dynamics (MD) calculations and inelastic x-ray scattering data. Here it is argued that the major effects of transits will be to disrupt correlations within the normal-mode vibrational motion and to provide an additional source of inelastic scattering. We construct a parametrized model for these effects and show that it is capable of fitting MD results for S(q,omega) in liquid sodium. A small discrepancy between model and MD at large q is attributed to multimode vibrational scattering. In comparison, mode coupling theory formulates S(q,omega) in terms of processes through which density fluctuations decay. While mode coupling theory is also capable of modeling S(q,omega) very well, V-T theory is the more universal since it expresses all statistical averages, thermodynamic functions, and time correlation functions alike, in terms of the same motional constituents, vibrations and transits. (c) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP De Lorenzi-Venneri, G (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM gvenneri@lanl.gov NR 35 TC 2 Z9 2 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 DEC 22 PY 2005 VL 123 IS 24 AR 244513 DI 10.1063/1.2140278 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 998SQ UT WOS:000234340100030 PM 16396555 ER PT J AU English, NJ Johnson, JK Taylor, CE AF English, NJ Johnson, JK Taylor, CE TI Molecular-dynamics simulations of methane hydrate dissociation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SIMPLE POINT-CHARGE; LIQUID WATER; CRYSTAL-GROWTH; COMPUTER-SIMULATION; CLATHRATE-HYDRATE; SYSTEMS; FIELDS; ICE; SUMMATION; RANGE AB Nonequilibrium molecular-dynamics simulations have been carried out at 276.65 K and 68 bar for the dissolution of spherical methane hydrate crystallites surrounded by a liquid phase. The liquid was composed of pure water or a water-methane mixture ranging in methane composition from 50% to 100% of the corresponding theoretical maximum for the hydrate and ranged in size from about 1600 to 2200 water molecules. Four different crystallites ranging in size from 115 to 230 water molecules were used in the two-phase systems; the nanocrystals were either empty or had a methane occupation from 80% to 100% of the theoretical maximum. The crystal-liquid systems were prepared in two distinct ways, involving constrained melting of a bulk hydrate system or implantation of the crystallite into a separate liquid phase. The breakup rates were very similar for the four different crystal sizes investigated. The method of system preparation was not found to affect the eventual dissociation rates, despite a lag time of approximately 70 ps associated with relaxation of the liquid interfacial layer in the constrained melting approach. The dissolution rates were not affected substantially by methane occupation of the hydrate phase in the 80%-100% range. In contrast, empty hydrate clusters were found to break up significantly more quickly. Our simulations indicate that the diffusion of methane molecules to the surrounding liquid layer from the crystal surface appears to be the rate-controlling step in hydrate breakup. Increasing the size of the liquid phase was found to reduce the initial delay in breakup. We have compared breakup rates computed using different long-range electrostatic methods. Use of the Ewald, minimum image, and spherical cut-off techniques led to more rapid dissociation relative to the Lekner method. (c) 2005 American Institute of Physics. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Univ Pittsburgh, Dept Chem Engn, Pittsburgh, PA 15261 USA. RP English, NJ (reprint author), St Johns Innovat Ctr, Chem Comp Grp, Cambridge CB4 0WS, England. EM nenglish@chemcomp.com RI Johnson, Karl/E-9733-2013 OI Johnson, Karl/0000-0002-3608-8003 NR 48 TC 68 Z9 69 U1 3 U2 19 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 2005 VL 123 IS 24 AR 244503 DI 10.1063/1.2138697 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 998SQ UT WOS:000234340100020 PM 16396545 ER PT J AU Starodub, D Doak, RB Schmidt, K Weierstall, U Wu, JS Spence, JCH Howells, M Marcus, M Shapiro, D Barty, A Chapman, HN AF Starodub, D Doak, RB Schmidt, K Weierstall, U Wu, JS Spence, JCH Howells, M Marcus, M Shapiro, D Barty, A Chapman, HN TI Damped and thermal motion of laser-aligned hydrated macromolecule beams for diffraction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULES; ALIGNMENT; FIELDS; PROTEINS; DYNAMICS AB We consider a monodispersed Rayleigh droplet beam of water droplets doped with proteins. An intense infrared laser is used to align these droplets. The arrangement has been proposed for electron- and x-ray-diffraction studies of proteins which are difficult to crystallize. This paper considers the effect of thermal fluctuations on the angular spread of alignment in thermal equilibrium, and relaxation phenomena, particularly the damping of oscillations excited as the molecules enter the field. The possibility of adiabatic alignment is also considered. We find that damping times in a high-pressure gas cell as used in x-ray-diffraction experiments are short compared with the time taken for molecules to traverse the beam and that a suitably shaped field might be used for electron-diffraction experiments in vacuum to provide adiabatic alignment, thus obviating the need for a damping gas cell. (c) 2005 American Institute of Physics. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Davis, Ctr Biophoton Sci & Technol, Sacramento, CA 95817 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Starodub, D (reprint author), Arizona State Univ, Dept Phys & Astron, POB 871504, Tempe, AZ 85287 USA. EM dmitri.starodub@asu.edu RI Chapman, Henry/G-2153-2010; Weierstall, Uwe/B-3568-2011; Barty, Anton/K-5137-2014 OI Chapman, Henry/0000-0002-4655-1743; Barty, Anton/0000-0003-4751-2727 NR 24 TC 11 Z9 11 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 2005 VL 123 IS 24 AR 244304 DI 10.1063/1.2137313 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 998SQ UT WOS:000234340100009 PM 16396534 ER PT J AU Zubarev, DY Boldyrev, AI Li, X Cui, LF Wang, LS AF Zubarev, DY Boldyrev, AI Li, X Cui, LF Wang, LS TI Chemical bonding in Si-5(2-) and NaSi5- via photoelectron spectroscopy and ab initio calculations SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID SMALL SILICON CLUSTERS; SMALL SI CLUSTERS; ORBITAL MOLECULAR-DYNAMICS; GLOBAL GEOMETRY OPTIMIZATION; DENSITY-FUNCTIONAL THEORY; INTERATOMIC FORCE-FIELDS; RESONANCE MASS-SPECTROMETRY; FEMTOSECOND LASER-ABLATION; TRANSITION-METAL CLUSTERS; SODIUM BINARY CLUSTERS AB Photoelectron spectroscopy and ab initio calculations are used to investigate the electronic structure and chemical bonding Of Si-5(-) and Si-5(2-) and NaSi5- in NaSi5-. Photoelectron spectra of Si-5(-) and NaSi5- are obtained at several photon energies and are compared with theoretical calculations at four different levels of theory, TD-B3LYP, R(U)OVGF, UCCSD(T), and EOM-CCSD(T), all with 6-311+G(2df) basis sets. Excellent agreement is observed between experiment and theory, confirming the obtained ground-state structures for Si-5(-) and Si-5(2-), which are both found to be trigonal bipyramid with D-3h symmetry at several levels of theory. Chemical bonding in Si-5, Si-5(-), and Si-5(2-) is analyzed using NPA, molecular orbitals, ELF, and NICS indices. The bonding in Si-5(2-) is compared with that in the isoelectronic and isostructural B5H52- species, but they are found to differ due to the involvement of electron densities, which are supposed to be lone pairs in the skeletal bonding in Si-5(2-). C1 Washington State Univ, Dept Phys, Richland, WA 99356 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. RP Boldyrev, AI (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99356 USA. EM boldyrev@cc.usu.edu; ls.wang@pnl.gov RI Boldyrev, Alexander/C-5940-2009 OI Boldyrev, Alexander/0000-0002-8277-3669 NR 147 TC 20 Z9 21 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 DEC 22 PY 2005 VL 109 IS 50 BP 11385 EP 11394 DI 10.1021/jp0526748 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400007 PM 16354025 ER PT J AU Woo, HK Wang, XB Kiran, B Wang, LS AF Woo, HK Wang, XB Kiran, B Wang, LS TI Temperature-dependent photoelectron spectroscopy of methyl benzoate anions: Observation of steric effect in o-methyl benzoate SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MULTIPLY-CHARGED ANIONS; C-H; HYDROGEN-BOND; CRYSTALLOGRAPHIC EVIDENCE; ACIDS; PHOTODETACHMENT; ACIDITIES; PHENOLS; H...O AB Temperature-dependent photoelectron spectra of benzoate anion (C6H5CO2-) and its three methyl-substituted isomers (o-, m-, p-CH3C6H4CO2-) have been obtained using a newly developed low-temperature photoelectron spectroscopy apparatus that features an electrospray source and a cryogenically controlled ion trap. Detachment channels due to removing electrons from the carboxylate group and benzene ring T electrons were distinctly observed. Well-resolved vibrational structures were obtained in the lower binding energy region due to the OCO bending modes, except for o-CH3C6H4CO2-, which yielded broad spectra even at the lowest ion trap temperature (18 K). Theoretical calculations revealed a large geometry change in the OCO angles between the anion and neutral ground states, consistent with the broad ground-state bands observed for all species. A strong steric effect was observed between the carboxylate and the methyl group in o-CH3C6H4CO2-, such that the -CO2- group is pushed out of the plane of the benzene ring by similar to 25 degrees and its internal rotational barrier is significantly reduced. The low rotational barrier in o-CH3C6H4CO2-, which makes it very difficult to be cooled vibrationally, and the strong coupling between the OCO bending and CO2 torsional modes yielded the broad PES spectra for this isomer. It is shown that there is no C-(HO)-O-... hydrogen bond in o-CH3C6H4CO2-, and the interaction between the carboxylate and methyl groups in this anion is found to be repulsive in nature. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99354 USA. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99354 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. EM ls.wang@pnl.gov NR 34 TC 15 Z9 15 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 22 PY 2005 VL 109 IS 50 BP 11395 EP 11400 DI 10.1021/jp0529467 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400008 PM 16354026 ER PT J AU Haranczyk, M Rak, J Gutowski, M AF Haranczyk, M Rak, J Gutowski, M TI Stabilization of very rare tautomers of 1-methylcytosine by an excess electron SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID THEORETICAL AB-INITIO; FREE PROTON-TRANSFER; DIPOLE-BOUND ANIONS; NUCLEIC-ACID BASES; MATRIX-ISOLATION; DNA BASES; IONIZATION-POTENTIALS; INFRARED-SPECTRA; AQUEOUS-SOLUTION; SPIN-RESONANCE AB We characterized valence anionic states of 1-methylcytosine using various electronic structure methods. We found that the most stable valence anion is related to neither the canonical amino-oxo nor a rare imino-oxo tautomer, in which a proton is transferred from the N4 to N3 atom. Instead, it is related to an imino-oxo tautomer, in which the C5 atom is protonated. This anion is characterized by an electron vertical detachment energy (VDE) of 2.12 eV and it is more stable than the anion based on the canonical tautomer by 1.0 kcal/ mol. The latter is characterized by a VDE of 0.31 eV. Another unusual low-lying imino-oxo tautomer with a VDE of 3.60 eV has the C6 atom protonated and is 3.6 kcal/mol less stable than the anion of the canonical tautomer. All these anionic states are adiabatically unbound with respect to the canonical amino-oxo neutral, with the instability of 53 kcal/mol for the most stable valence anion. The mechanism of formation of anionic tautomers with carbon atoms protonated may involve intermolecular proton transfer or dissociative electron attachment to the canonical neutral tautomer followed by a barrier-free attachment of a hydrogen atom to the C5 or C6 atom. The six-member ring structure of anionic tautomers with carbon atoms protonated is unstable upon an excess electron detachment. Indeed the neutral systems collapse without a barrier to a linear or a bicyclo structure, which might be viewed as lesions to DNA or RNA. Within the PCM hydration model, the anions become adiabatically bound with respect to the corresponding neutrals, and the two most stable tautomers have a carbon atom protonated. C1 Pacific NW Natl Lab, Div Chem Sci, Fundamental Sci Directorate, Richland, WA 99352 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. RP Gutowski, M (reprint author), Pacific NW Natl Lab, Div Chem Sci, Fundamental Sci Directorate, Richland, WA 99352 USA. EM maciej.gutowski@pnl.gov RI Haranczyk, Maciej/A-6380-2014 OI Haranczyk, Maciej/0000-0001-7146-9568 NR 83 TC 30 Z9 30 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 DEC 22 PY 2005 VL 109 IS 50 BP 11495 EP 11503 DI 10.1021/jp0535590 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400022 PM 16354040 ER PT J AU Zheng, WJ Bowen, KH Li, J Dabkowska, I Gutowski, M AF Zheng, WJ Bowen, KH Li, J Dabkowska, I Gutowski, M TI Electronic structure differences in ZrO2 vs HfO2 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ION PHOTOELECTRON-SPECTROSCOPY; BASIS-SETS; AB-INITIO; N-BUTANE; ATOMS; STABILITY; ZIRCONIUM; OXIDES; ISOMERIZATION; POTENTIALS AB Although ZrO2 and HfO2 are, for the most part, quite similar chemically, subtle differences in their electronic structures appear to be responsible for differing MO2)/Si (M = Zr, Hf) interface stabilities. To shed light on the electronic structure differences between ZrO2 and HfO2, we have conducted joint experimental and theoretical studies. Because molecular electron affinities are a sensitive probe of electronic structure, we have measured them by conducting photoelectron spectroscopic experiments on ZrO2- and HfO2_. The adiabatic electron affinity of HfO2 was determined to be 2.14 +/- 0.03 eV, and that of ZrO2 was determined to be 1.64 +/- 0.03 eV. Concurrently, advanced electronic structure calculations were conducted to determine electron affinities, vibrational frequencies, and geometries of these systems. The calculated CCSD(T) electron affinities of HfO2 and ZrO2 were found to be 2.05 and 1.62 eV, respectively. The molecular results confirm earlier predictions from solid state calculations that HfO2 is more ionic than ZrO2. The excess electron in MO,occupies an sd-type hybrid orbital localized on the M atom (M = Zr, Hf). The structural parameters of ZrO2 and HfO2 and their vibrational frequencies were found to be very similar. Upon the excess electron attachment, the M-O bond length increases by ca. 0.04 angstrom, the OMO angle increases by 2-4 degrees, and frequencies of all vibrational modes become smaller, with the stretching modes being shifted by 30-50 cm(-1) and the bending C, mode by 15-25 cm(-1). Together, these studies unveil significant differences in the electronic structures of ZrO2 and HfO2, but not in their structural or vibrational characteristics. C1 Johns Hopkins Univ, Dept Chem & Mat Sci, Baltimore, MD 21218 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. RP Gutowski, M (reprint author), Johns Hopkins Univ, Dept Chem & Mat Sci, Baltimore, MD 21218 USA. EM maciej.gutowski@pnl.gov RI Li, Jun/E-5334-2011 OI Li, Jun/0000-0002-8456-3980 NR 39 TC 61 Z9 61 U1 1 U2 27 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 DEC 22 PY 2005 VL 109 IS 50 BP 11521 EP 11525 DI 10.1021/jp053593e PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400025 PM 16354043 ER PT J AU Elliott, BM Koyle, E Boldyrev, AI Wang, XB Wang, LS AF Elliott, BM Koyle, E Boldyrev, AI Wang, XB Wang, LS TI MX3- superhalogens (M = Be, Mg, Ca; X = Cl, Br): A photoelectron spectroscopic and ab initio theoretical study SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID QUADRATIC CONFIGURATION-INTERACTION; GENERALIZED GRADIENT APPROXIMATION; ELECTRON PROPAGATOR THEORY; DENSITY-FUNCTIONAL THEORY; MOLECULAR-ORBITAL METHODS; COUPLED-CLUSTER SINGLES; MULTIPLY-CHARGED ANIONS; NEGATIVE-IONS; COMPOUND FORMATION; IONIZATION-POTENTIALS AB Gas-phase alkaline earth halide anions, MgX3- and CaX3- (X = Cl, Br), were produced using electrospray and investigated using photoelectron spectroscopy at 157 nm. Extremely high electron binding energies were observed for all species and their first vertical detachment energies were measured as 6.60 +/- 0.04 eV for MgCl3-, 6.00 +/- 0.04 eV for MgBr3-, 6.62 +/- 0.04 eV for CaCl3-, and 6.10 +/- 0.04 eV for CaBr3-. The high electron binding energies indicate these are very stable anions and they belong to a class of anions, called superhalogens. Theoretical calculations at several levels of theory were carried out on these species, as well as the analogous BeX3-. Vertical detachment energy spectra were predicted to compare with the experimental observations, and good agreement was obtained for all species. The first adiabatic detachment energies were found to be substantially lower (by about 1 eV) than the corresponding vertical detachment energies for all the MX3- species, indicating extremely large geometry changes between MX3- and MX3. We found that all the MX3- anions possess D-3h ((1)A(1)') structures and are extremely stable against dissociation into MX2 and X-. The corresponding neutral species MX3, however, were found to be only weakly bound with respect to dissociation toward MX2 + X. The global minimum structures of all the MX3 neutrals were found to be C-2v (B-2(2)), which can be described as (X-2(-))(MX+) charge-transfer complexes, whereas the (MX2X)-X-... (C-2v, B-2(1)) van der Waals complexes were shown to be low-lying isomers. C1 Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. Washington State Univ, Dept Phys, Richland, WA 99354 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. RP Boldyrev, AI (reprint author), Utah State Univ, Dept Chem & Biochem, 0300 Old Main Hill, Logan, UT 84322 USA. EM boldyrev@cc.usu.edu; ls.wang@pnl.gov RI Boldyrev, Alexander/C-5940-2009 OI Boldyrev, Alexander/0000-0002-8277-3669 NR 105 TC 97 Z9 99 U1 2 U2 16 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 DEC 22 PY 2005 VL 109 IS 50 BP 11560 EP 11567 DI 10.1021/jp054036v PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400030 PM 16354048 ER PT J AU de Jong, WA Apra, E Windus, TL Nichols, JA Harrison, RJ Gutowski, KE Dixon, DA AF de Jong, WA Apra, E Windus, TL Nichols, JA Harrison, RJ Gutowski, KE Dixon, DA TI Complexation of the carbonate, nitrate, and acetate anions with the uranyl dication: Density functional studies with relativistic effective core potentials SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ENERGY-ADJUSTED PSEUDOPOTENTIALS; X-RAY-DIFFRACTION; AQUEOUS-SOLUTION; ELECTRONIC-STRUCTURE; NEUTRON-DIFFRACTION; SPECTROSCOPIC CHARACTERIZATION; VIBRATIONAL FREQUENCIES; ACTINIDE COMPOUNDS; CRYSTAL-STRUCTURE; RAMAN AB The structures and vibrational frequencies of uranyl carbonates, [UO2(CO3)(n)])((2-2n)) and [(UO2)(3)(CO3)(6)],(6-) uranyl nitrates, [UO2(NO3)(n)]((2-n)), and uranyl acetates, [UO2(CH3COO)(n)]((2-n)) (n = 1,2,3) have been calculated by using local density functional theory (LDFT). Only bidentate ligand coordination modes to the uranyl dication have been modeled. The calculated structures and frequencies are compared to available experimental data, including IR, Raman, X-ray diffraction, and EXAFS solution and crystal structure data. The energetics of ligand binding have been calculated using the B3LYP hybrid functional. In general, the structural and vibrational results at the LDFT level are in good agreement with experimental results and provide realistic pictures of solution phase and solid-state behavior. For the [UO2(CO3)(3)](6-) anion, calculations suggest that complexity in the CO32- stretching signature upon complexation is due to the formation of C=O and C-O domains, the latter of which can split by as much as 300 cm(-1). Assessment of the binding energies indicate that the [UO2(CO3)(2)](2-) anion is more stable than the [UO2(CO3)(3)](4-) anion due to the accumulation of excess charge, whereas the tri-ligand species are the most stable in the nitrate and acetate anions. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. RP Dixon, DA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. EM dadixon@bama.ua.edu RI DE JONG, WIBE/A-5443-2008; Apra, Edoardo/F-2135-2010; OI DE JONG, WIBE/0000-0002-7114-8315; Apra, Edoardo/0000-0001-5955-0734; Nichols, Jeffrey/0000-0001-5454-9726 NR 79 TC 65 Z9 67 U1 3 U2 27 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 DEC 22 PY 2005 VL 109 IS 50 BP 11568 EP 11577 DI 10.1021/jp0541462 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400031 PM 16354049 ER PT J AU Shepard, R AF Shepard, R TI A general nonlinear expansion form for electronic wave functions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID UNITARY-GROUP-APPROACH; CONFIGURATION-INTERACTION AB A new expansion form is presented for electronic wave functions. The wave function is a linear combination of product basis functions, and each product basis function in turn is formally equivalent to a linear combination of configuration state functions that comprise an underlying linear expansion space. The expansion coefficients that define the basis functions are nonlinear functions of a smaller number of variables. The expansion form is appropriate for both ground and excited states and to both closed and open shell molecules. The method is formulated in terms of spin-eigenfunctions using the graphical unitary group approach (GUGA), and consequently it does not suffer from spin contamination. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shepard, R (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM shepard@tcg.anl.gov NR 19 TC 31 Z9 31 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 DEC 22 PY 2005 VL 109 IS 50 BP 11629 EP 11641 DI 10.1021/jp0543431 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995QR UT WOS:000234119400038 PM 16354056 ER PT J AU Choi, JF Lucas, D Koshland, CP Sawyer, RF AF Choi, JF Lucas, D Koshland, CP Sawyer, RF TI Photochemical interaction of polystyrene nanospheres with 193 nm pulsed laser light SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID FRAGMENTATION FLUORESCENCE SPECTROSCOPY; METAL NANOPARTICLES; POLYMER SURFACES; ABLATION; ULTRAVIOLET; PARTICLES; IRRADIATION; NANOSECOND; RADIATION; BREAKDOWN AB The photochemical interaction of 193 nm light with polystyrene nanospheres is used to produce particles with a controlled size and morphology. Laser fluences from 0 to 0.14 J/cm(2) at 10 and 50 Hz photofragment nearly monodisperse I 10 nm spherical polystyrene particles. The size distributions before and after irradiation are measured with a scanning mobility particle sizer (SMPS), and the morphology of the irradiated particles is examined with a transmission electron microscope (TEM). The results show that the irradiated particles have a smaller mean diameter (similar to 25 nm) and a number concentration more than an order of magnitude higher than nonirradiated particles. The particles are formed by nucleation of gas-phase species produced by photolytic decomposition of nanospheres. A nondimensional parameter, the photon-to-atom ratio (PAR), is used to interpret the laser-particle interaction energetics. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. RP Choi, JF (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. EM jhyunc@me.berkeley.edu RI Sawyer, Robert/B-5013-2014 FU NIEHS NIH HHS [P42-ES047050-01] NR 38 TC 2 Z9 2 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD DEC 22 PY 2005 VL 109 IS 50 BP 23905 EP 23910 DI 10.1021/jp0540611 PG 6 WC Chemistry, Physical SC Chemistry GA 995QO UT WOS:000234119100019 PM 16375376 ER PT J AU Kirmaier, C Bautista, JA Laible, PD Hanson, DK Holten, D AF Kirmaier, C Bautista, JA Laible, PD Hanson, DK Holten, D TI Probing the contribution of electronic coupling to the directionality of electron transfer in photosynthetic reaction centers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BACTERIAL REACTION CENTERS; RHODOBACTER-SPHAEROIDES R-26; VIRIDIS REACTION CENTERS; PRIMARY CHARGE SEPARATION; ENERGY-TRANSFER PATHWAYS; MUTANT REACTION CENTERS; RHODOPSEUDOMONAS-VIRIDIS; WILD-TYPE; EXCITED-STATES; PRIMARY DONOR AB Subpicosecond transient absorption studies are reported for a set of Rhodobacter (R.) capsulatus bacterial photosynthetic reaction centers (RCs) designed to probe the origins of the unidirectionality of charge separation via one of two electron transport chains in the native piginent-protem complex. All of the RCs have been engineered to contain a heterodimeric primary electron donor (D) consisting of a bacteriochlorophyll (BChl) and a bacteriopheophytin (BPh). The BPh component of the M heterodimer (Mhd) or L heterodimer (Lhd) is introduced by substituting a Len for His M200 or His L173, respectively. Previous work on primary charge separation in heterodimer mutants has not included the Lhd RC from R. capsulatus, which we report for the first time. The Lhd and Mhd RCs are used as controls against which we assess RCs that combine the heterodimer mutations with a second mutation (His substituted for Leu at M212) that results in replacement of the native L-side BPh acceptor with a BChl (p). The transient absorption spectra reveal clear evidence for charge separation to the normally inactive M-side BPh acceptor (H-M) in Lhd-beta RCs to form D+HM- with a yield of similar to 6%. This state also forms in Mbd-beta RCs but with about one-quarter the yield. In both RCs, deactivation to the ground state is the predominant pathway of D* decay, as it is in the Mhd and Lhd single mutants. Analysis of the results indicates an upper limit of V-L(2)/V-M(2) <= 4 for the contribution of the electronic coupling elements to the relative rates of electron transfer to the L versus M sides of the wild-type RC. In comparison to the L/M rate ratio (k(L)/k(M)) approximate to 30 for wild-type RCs, our findings indicate that electronic factors contribute similar to 35% at most to directionality with the other 65% deriving from energetic considerations, which includes differences in free energies, reorganization energies, and contributions of one- and two-step mechanisms on the two sides of the RC. C1 Washington Univ, Dept Chem, St Louis, MO 63130 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Holten, D (reprint author), Washington Univ, Dept Chem, St Louis, MO 63130 USA. EM holten@wuchem.wustl.edu NR 85 TC 21 Z9 24 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 DEC 22 PY 2005 VL 109 IS 50 BP 24160 EP 24172 DI 10.1021/jp054726z PG 13 WC Chemistry, Physical SC Chemistry GA 995QO UT WOS:000234119100051 PM 16375408 ER PT J AU Knauth, LP Burt, DM Wohletz, KH AF Knauth, LP Burt, DM Wohletz, KH TI Impact origin of sediments at the opportunity landing site on Mars SO NATURE LA English DT Article ID MERIDIANI-PLANUM; ACCRETIONARY LAPILLI; CRATER EJECTA; SOUTH-AFRICA; HEMATITE; WATER; ENVIRONMENT; DEPOSITS; GEOCHEMISTRY; EVOLUTION AB Mars Exploration Rover Opportunity discovered sediments with layered structures thought to be unique to aqueous deposition and with minerals attributed to evaporation of an acidic salty sea. Remarkable iron-rich spherules were ascribed to later groundwater alteration, and the inferred abundance of water reinforced optimism that Mars was once habitable. The layered structures, however, are not unique to water deposition, and the scenario encounters difficulties in accounting for highly soluble salts admixed with less soluble salts, the lack of clay minerals from acid - rock reactions, high sphericity and near- uniform sizes of the spherules and the absence of a basin boundary. Here we present a simple alternative explanation involving deposition from a ground-hugging turbulent flow of rock fragments, salts, sulphides, brines and ice produced by meteorite impact. Subsequent weathering by intergranular water films can account for all of the features observed without invoking shallow seas, lakes or near- surface aquifers. Layered sequences observed elsewhere on heavily cratered Mars and attributed to wind, water or volcanism may well have formed similarly. If so, the search for past life on Mars should be reassessed accordingly. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Knauth, LP (reprint author), Arizona State Univ, Dept Geol Sci, Box 871404, Tempe, AZ 85287 USA. EM Knauth@asu.edu NR 50 TC 89 Z9 89 U1 5 U2 17 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD DEC 22 PY 2005 VL 438 IS 7071 BP 1123 EP 1128 DI 10.1038/nature04383 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 995OF UT WOS:000234111500042 PM 16372001 ER PT J AU Rest, A Suntzeff, NB Olsen, K Prieto, JL Smith, RC Welch, DL Becker, A Bergmann, M Clocchiatti, A Cook, K Garg, A Huber, M Miknaitis, G Minniti, D Nikolaev, S Stubbs, C AF Rest, A Suntzeff, NB Olsen, K Prieto, JL Smith, RC Welch, DL Becker, A Bergmann, M Clocchiatti, A Cook, K Garg, A Huber, M Miknaitis, G Minniti, D Nikolaev, S Stubbs, C TI Light echoes from ancient supernovae in the Large Magellanic Cloud SO NATURE LA English DT Article ID SN 1991T; SEARCH; REFLECTIONS; REMNANTS; 1993J AB The light from historical supernovae could in principle still be visible as scattered-light echoes centuries after the explosion(1-6). The detection of light echoes could allow us to pinpoint the supernova event both in position and age and, most importantly, permit the acquisition of spectra to determine the 'type' of the supernova centuries after the direct light from the explosion first reached Earth. Although echoes have been discovered around some nearby extragalactic supernovae(7-13), targeted searches have not found any echoes in the regions of historical Galactic supernovae(14-16). Here we report three faint variable-surface-brightness complexes with high apparent proper motions pointing back to three of the six smallest ( and probably youngest) previously catalogued supernova remnants in the Large Magellanic Cloud, which are believed to have been thermonuclear ( type Ia) supernovae(17). Using the distance and apparent proper motions of these echo arcs, we estimate ages of 610 and 410 years for two of them. C1 Cerro Tololo Interamer Observ, Natl Opt Astron Observ, La Serena, Chile. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Gemini Observ, La Serena, Chile. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago, Chile. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Harvard Univ, Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Suntzeff, NB (reprint author), Cerro Tololo Interamer Observ, Natl Opt Astron Observ, La Serena, Chile. EM nsuntzeff@ctio.noao.edu RI Stubbs, Christopher/C-2829-2012 OI Stubbs, Christopher/0000-0003-0347-1724 NR 25 TC 75 Z9 77 U1 0 U2 1 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 22 PY 2005 VL 438 IS 7071 BP 1132 EP 1134 DI 10.1038/nature04365 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 995OF UT WOS:000234111500044 PM 16372003 ER PT J AU Flanagan, JF Mi, LZ Chruszcz, M Cymborowski, M Clines, KL Kim, YC Minor, W Rastinejad, F Khorasanizadeh, S AF Flanagan, JF Mi, LZ Chruszcz, M Cymborowski, M Clines, KL Kim, YC Minor, W Rastinejad, F Khorasanizadeh, S TI Double chromodomains cooperate to recognize the methylated histone H3 tail SO NATURE LA English DT Article ID DNA-BINDING; CHROMATIN; NUCLEOSOME; CHD1; PROTEINS; COMPLEX; GENES AB Chromodomains are modules implicated in the recognition of lysine-methylated histone tails and nucleic acids(1,2). CHD ( for chromo-ATPase/helicase-DNA-binding) proteins regulate ATP-dependent nucleosome assembly and mobilization through their conserved double chromodomains and SWI2/SNF2 helicase/ ATPase domain(3-5). The Drosophila CHD1 localizes to the interbands and puffs of the polytene chromosomes, which are classic sites of transcriptional activity(6). Other CHD isoforms (CHD3/4 or Mi-2) are important for nucleosome remodelling in histone deacetylase complexes(7,8). Deletion of chromodomains impairs nucleosome binding and remodelling by CHD proteins(4). Here we describe the structure of the tandem arrangement of the human CHD1 chromodomains, and its interactions with histone tails. Unlike HP1 and Polycomb proteins that use single chromodomains to bind to their respective methylated histone H3 tails, the two chromodomains of CHD1 cooperate to interact with one methylated H3 tail. We show that the human CHD1 double chromodomains target the lysine 4-methylated histone H3 tail (H3K4me), a hallmark of active chromatin(9). Methylammonium recognition involves two aromatic residues, not the three-residue aromatic cage used by chromodomains of HP1 and Polycomb proteins(10-13). Furthermore, unique inserts within chromodomain 1 of CHD1 block the expected site of H3 tail binding seen in HP1 and Polycomb, instead directing H3 binding to a groove at the inter-chromodomain junction. C1 Univ Virginia Hlth Syst, Dept Biochem & Mol Genet, Charlottesville, VA 22908 USA. Univ Virginia Hlth Syst, Dept Pharmacol, Charlottesville, VA 22908 USA. Univ Virginia Hlth Syst, Dept Mol Physiol & Biol Phys, Charlottesville, VA 22908 USA. Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. RP Khorasanizadeh, S (reprint author), Univ Virginia Hlth Syst, Dept Biochem & Mol Genet, Charlottesville, VA 22908 USA. EM fr9c@virginia.edu; khorasan@virginia.edu RI Chruszcz, Maksymilian/E-6407-2011; Minor, Wladek/F-3096-2014; Mi, Li-Zhi/B-1371-2016; OI Mi, Li-Zhi/0000-0001-9907-5245; Chruszcz, Maksymilian/0000-0001-7521-5485; Minor, Wladek/0000-0001-7075-7090 NR 28 TC 309 Z9 317 U1 3 U2 23 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 22 PY 2005 VL 438 IS 7071 BP 1181 EP 1185 DI 10.1038/nature04290 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 995OF UT WOS:000234111500056 PM 16372014 ER PT J AU Roeder, JL Chen, MW Fennell, JF Friedel, R AF Roeder, JL Chen, MW Fennell, JF Friedel, R TI Empirical models of the low-energy plasma in the inner magnetosphere SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article ID SHEET ACCESS; ION; SPACECRAFT AB Particle flux measurements by the Charge and Mass Magnetospheric Ion Composition Experiment/Magnetospheric Ion Composition Spectrometer (CAMMICE/MICS) and Hydra instruments on the NASA Polar satellite have been used to build empirical models of the plasma environment at low energies in the Earth's inner magnetosphere. These models may be used to develop design and to test specifications for spacecraft surface materials, which are susceptible to damage by the ions. The combination of the CAMMICE/MICS and Hydra models provides the ion flux at energies in the range 20 eV to 200 keV as a function of position in the magnetosphere. For the 1-200 keV energy range, the H(+) and O(+) ion flux is estimated separately using the CAMMICE/MICS data. Average environments have been calculated for several sample orbital trajectories: a geosynchronous orbit and the orbits of several satellites in the Global Positioning System (GPS) constellation. At high energies (similar to 100 keV), the flux estimates agree with corresponding estimates from the NASA AP-8 model, but the fluxes at low energies are larger than those extrapolated simply from AP-8. The CAMMICE/MICS model shows that H(+) dominates the >2 keV ion populations, but the O(+) flux becomes comparable to the H(+) flux at similar to 1 keV. The standard deviation of both the ion and electron flux was found to be 100-200% of the average value over the entire considered energy range. The average 1-200 keV O(+) flux estimates for GEO appear similar to the averages for GPS orbit, so material damage due to O(+) in this energy range should be similar for the two orbits. C1 Aerosp Corp, Los Angeles, CA 90009 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Roeder, JL (reprint author), Aerosp Corp, POB 92957, Los Angeles, CA 90009 USA. EM james.l.roeder@aero.org RI Friedel, Reiner/D-1410-2012; Chen, Margaret/C-9658-2013 OI Friedel, Reiner/0000-0002-5228-0281; Chen, Margaret/0000-0001-7771-4771 NR 15 TC 19 Z9 20 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD DEC 22 PY 2005 VL 3 IS 12 BP 1 EP 11 AR S12B06 DI 10.1029/2005SW000161 PG 11 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 022AW UT WOS:000236028000001 ER PT J AU Genson, KL Holzmueller, J Vaknin, D Villavicencio, OF McGrath, DV Tsukruk, VV AF Genson, KL Holzmueller, J Vaknin, D Villavicencio, OF McGrath, DV Tsukruk, VV TI Langmuir monolayers from functionalized amphiphiles with epoxy terminal groups SO THIN SOLID FILMS LA English DT Article DE LB films; surface structures; atomic force microscopy; X-ray scattering ID AIR-WATER-INTERFACE; X-RAY-DIFFRACTION; REVERSIBLE OPTICAL STORAGE; SELF-ASSEMBLED MONOLAYERS; SCANNING PROBE MICROSCOPY; AZO POLYMERS; PHASE-TRANSITIONS; AZOBENZENE; FILMS; LIQUID AB We studied Langmuir and Langmuir-Blodgett monolayers from amphiphiles with traditional (carboxylic) and bulky functionalized (epoxy) terminal groups at the air-water and air-solid interfaces. We demonstrated that the molecules with a central azobenzene fragment and carboxylic (AA-1 molecule) and bulky epoxy (AE-1 molecule) polar groups formed orthorhombic unit cells with larger than expected area per alkyl tail. The higher order of symmetry indicated by the appearance of higher Q(xy) peaks revealed that the alkyl tails formed a herringbone structure with limited long range ordering. In the condensed monolayer, the azobenzene group of the AA-1 molecules was oriented vertically in contrast to the AE-1 molecule that was significantly tilted. In addition, the presence of the bulky epoxy focal groups caused a less dense lateral packing of the azobenzene groups. We suggest that the bulky focal group causes intramonolayer packing which can enhance the ability of the chemically grafted azobenzene groups for photoisomerization. (c) 2005 Elsevier B.V. All rights reserved. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, 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. EM Vladimir@iastate.edu RI McGrath, Dominic/A-7675-2012; Vaknin, David/B-3302-2009 OI Vaknin, David/0000-0002-0899-9248 NR 57 TC 7 Z9 7 U1 0 U2 3 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 DEC 22 PY 2005 VL 493 IS 1-2 BP 237 EP 248 DI 10.1016/j.tsf.2005.04.091 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 982IG UT WOS:000233150700038 ER PT J AU Specht, ED Rack, PD Rar, A Pharr, GM George, EP Fowkes, JD Hong, H Karapetrova, E AF Specht, ED Rack, PD Rar, A Pharr, GM George, EP Fowkes, JD Hong, H Karapetrova, E TI Metastable phase evolution and grain growth in annealed nanocrystalline Cr-Fe-Ni films SO THIN SOLID FILMS LA English DT Article DE Cr-Fe-Ni; sputtering; X-ray diffraction; phase diagram ID THERMAL-STABILITY; ELECTRODEPOSITION; DEPOSITION; ALLOYS AB Nanocrystalline Cr-Fe-Ni thin films libraries are prepared by radio frequency magnetron sputter codeposition on Al2O3 substrates. The variation in distance from different points on the substrate to the three sputter sources produces a spread in composition in the films. Synchrotron radiation is used to analyze composition, crystallographic phase, and grain size as a function of sample position, both as-deposited and after annealing. In addition to three equilibrium phases (bcc, fcc and sigma-FeCr), a fourth phase is observed which does not correspond to any equilibrium phase in the Cr-Fe-Ni system, but which is consistent with the alpha-Mn structure. The films are initially nanocrystalline; both equilibrium and nonequilibrium phases are observed. Tertiary phase diagrams measured at annealing temperatures of 200-800 degrees C show that the stability of nanocrystalline material against thermal grain growth varies widely with composition, and that the crystallographic phase can be selected to be an appropriate heat treatment. Thus, the approach used here is useful for technologies such as magnetic recording media where understanding the stability of the nanograin structure is critical. (c) 2005 Elsevier B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. RP Specht, ED (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. EM spechted@ornl.gov RI George, Easo/L-5434-2014; Specht, Eliot/A-5654-2009; OI Specht, Eliot/0000-0002-3191-2163; Rack, Philip/0000-0002-9964-3254 NR 15 TC 12 Z9 14 U1 3 U2 17 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 DEC 22 PY 2005 VL 493 IS 1-2 BP 307 EP 312 DI 10.1016/j.tsf.2005.07.285 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 982IG UT WOS:000233150700049 ER PT J AU Nieto, MM Anderson, JD AF Nieto, MM Anderson, JD TI Using early data to illuminate the Pioneer anomaly SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID LONG-RANGE ACCELERATION; ULYSSES DATA; PROSAIC EXPLANATION; DISTANT SPACECRAFT; JUPITER; GALILEO; WEAK; TRACKING; MATTER AB Analysis of the radio tracking data from the Pioneer 10/11 spacecraft at distances between about 20-70 AU from the Sun has consistently indicated the presence of an unmodelled, small, constant, Doppler blue shift drift of order 6 x 10(-9) Hz s(-1). After accounting for systematics, this drift can be interpreted as a constant acceleration of a(P) = (8.74 +/- 1.33) x 10(-8) cm s(-2) directed towards the Sun, or perhaps as a time acceleration of a(t) = (2.92 +/- 0.44) x 10(-18) s(-2). Although it is suspected that there is a systematic origin to this anomaly, none has been unambiguously demonstrated. We review the current status of the anomaly, and then point out how the analysis of early data, which was never analysed in detail, could allow a clearer understanding of the origin of the anomaly, be it a systematic or a manifestation of unsuspected physics. C1 Los Alamos Natl Lab, Theoret Div MSB285, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nieto, MM (reprint author), Los Alamos Natl Lab, Theoret Div MSB285, Los Alamos, NM 87545 USA. EM mmn@lanl.gov; john.d.anderson@jpl.nasa.gov NR 25 TC 33 Z9 33 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD DEC 21 PY 2005 VL 22 IS 24 BP 5343 EP 5354 DI 10.1088/0264-9381/22/24/008 PG 12 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 002QN UT WOS:000234626400008 ER PT J AU Durham, WB Stern, LA Kubo, T Kirby, SH AF Durham, WB Stern, LA Kubo, T Kirby, SH TI Flow strength of highly hydrated Mg- and Na-sulfate hydrate salts, pure and in mixtures with water ice, with application to Europa SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID INFRARED MAPPING SPECTROMETER; SUBSURFACE OCEAN; GEOLOGICAL EVIDENCE; SULFURIC-ACID; THERMAL STATE; SHELL; DEFORMATION; SURFACE; ROCKS; CRUST AB We selected two Europan-ice-shell candidate highly hydrated sulfate salts for a laboratory survey of ductile flow properties: MgSO4 center dot 7H(2)O (epsomite) and Na2SO4 center dot 10H(2)O (mirabilite), called MS7 and NS10, respectively. Polycrystalline samples in pure form and in mixtures with water ice I were tested using our cryogenic high-pressure creep apparatus at temperatures 232 <= T <= 294 K, confining pressures P = 50 and 100 MPa, and strain rates 4 x 10(-8) <= (epsilon)over dot <= 7 x 10(-5) s(-1). Grain size of NS10 samples was >100 mu m. The flow strength sigma of pure MS7 was over 100 times that of polycrystalline ice I at comparable conditions; that of pure NS10 over 20 times that of ice. In terms of the creep law (epsilon)over dot = A sigma(n) e(-Q/RT,) where R is the gas constant, we determine parameter values of A = 10(12.1) MPa-n s(-1), n = 5.4, and Q = 128 kJ/mol for pure NS10. Composites of ice I and NS10 of volume fraction phi(NS10) have flow strength sigma(c) = [phi(NS10)sigma(J)(NS10) + (1 - phi(NS10))sigma(J)(iceI)](1/J) where J approximate to -0.5, making the effect on the flow of ice with low volume fractions of NS10 much like that of virtually undeformable hard rock inclusions. Being much stronger and denser than ice, massive sulfate inclusions in the warmer, ductile layer of the Europan ice shell are less likely to be entrained in convective ice flow and more likely to be drawn to the base of the ice shell by gravitational forces and eventually expelled. With only smaller, dispersed sulfate inclusions, at probable sulfate phi < 0.2, the shell may be treated rheologically as pure, polycrystalline ice, with boundary conditions perhaps influenced by the high density and low thermal conductivity of the hydrated salts. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. US Geol Survey, Menlo Pk, CA 94025 USA. RP Lawrence Livermore Natl Lab, POB 808,L-201, Livermore, CA 94550 USA. EM durham1@llnl.gov NR 48 TC 13 Z9 13 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 21 PY 2005 VL 110 IS E12 AR E12010 DI 10.1029/2005JE002475 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 999CQ UT WOS:000234366700001 ER PT J AU Tarjus, G Kivelson, SA Nussinov, Z Viot, P AF Tarjus, G Kivelson, SA Nussinov, Z Viot, P TI The frustration-based approach of supercooled liquids and the glass transition: a review and critical assessment SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Review ID SELF-GENERATED RANDOMNESS; BOND-ORIENTATIONAL ORDER; HIGH-TEMPERATURE SUPERCONDUCTORS; LOCALLY PREFERRED STRUCTURE; AVOIDED CRITICAL-BEHAVIOR; CHOLESTERIC BLUE PHASE; METALLIC GLASSES; FORMING LIQUIDS; VORTEX-LATTICE; STRIPE GLASSES AB One of the most spectacular phenomena in physics in terms of dynamical range is the glass transition and the associated slowing down of flow and relaxation with decreasing temperature. That it occurs in many different liquids seems to call for a 'universal' theory. In this article, we review one such theoretical approach, which is based oil the concept of 'frustration'. Frustration in this context describes an incompatibility between extension of the locally preferred order in a liquid and tiling of the whole space. We provide a critical assessment of what has been achieved within this approach and we discuss its relation with other theories of the glass transition. C1 Univ Paris 06, Lab Phys Theor Mat Condensee, F-75252 Paris 05, France. Stanford Univ, Dept Phys, GLAM, Stanford, CA 94305 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Washington Univ, Dept Phys, St Louis, MO 63160 USA. RP Univ Paris 06, Lab Phys Theor Mat Condensee, 4 Pl Jussieu, F-75252 Paris 05, France. NR 142 TC 227 Z9 228 U1 9 U2 62 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD DEC 21 PY 2005 VL 17 IS 50 BP R1143 EP R1182 DI 10.1088/0953-8984/17/50/R01 PG 40 WC Physics, Condensed Matter SC Physics GA 998MY UT WOS:000234324200002 ER PT J AU Henager, CH Hoagland, RG AF Henager, CH Hoagland, RG TI Dislocation and stacking fault core fields in fcc metals SO PHILOSOPHICAL MAGAZINE LA English DT Article ID BOUNDARY-CONDITIONS; ATOMIC SIMULATION; EDGE DISLOCATION; ALPHA-IRON; DYNAMICS; MODEL AB Atomistic models were used to determine the properties of dislocation core fields and stacking fault fields in Al and Cu using embedded atom method (EAM) potentials. Long-range, linear elastic displacement fields due to nonlinear behaviour within dislocation cores, the core field, for relevant combinations of Shockley partial dislocations for edge, screw, and mixed (60 degrees and 30 degrees) geometries were obtained. Displacement fields of stacking faults were obtained separately and used to partition the core field of dissociated dislocations into core fields of partial dislocations and a stacking fault expansion field. Core field stresses were derived from which the total force, including the Volterra field plus core field, between dislocations for several dislocation configurations was determined. The Volterra field dominates when the distance between dislocations exceeds about 50b but forces due to core fields are important for smaller separation distances and were found to affect the equilibrium angle of edge dislocation dipoles and to contribute to the force between otherwise non-interacting edge and screw dislocations. Interactions among the components of a dissociated dislocation modify the equilibrium separation for Shockley partials suggesting that methods that determine stacking fault energies using measurements of separation distances should include core fields. C1 Pacific NW Natl Lab, Richland, WA 99335 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Henager, CH (reprint author), Pacific NW Natl Lab, Richland, WA 99335 USA. EM chuck.henager@pnl.gov RI Hoagland, Richard/G-9821-2012; OI Henager, Chuck/0000-0002-8600-6803 NR 26 TC 9 Z9 9 U1 0 U2 10 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1478-6435 J9 PHILOS MAG JI Philos. Mag. PD DEC 21 PY 2005 VL 85 IS 36 BP 4477 EP 4508 DI 10.1080/14786430500300181 PG 32 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 002ZZ UT WOS:000234652700005 ER PT J AU Konca, E Cheng, YT Weiner, AM Dasch, JM Erdemir, A Alpas, AT AF Konca, E Cheng, YT Weiner, AM Dasch, JM Erdemir, A Alpas, AT TI Transfer of 319 Al alloy to titanium diboride and titanium nitride based (TiAlN, TiCN, TiN) coatings: effects of sliding speed, temperature and environment SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE pin on disc; aluminum; adhesion coatings; sliding contact; titanium diboride; M2 steel ID MATRIX COMPOSITES; DUCTILE MATERIALS; SPECIMEN PAIRS; METAL TRANSFER; TRANSFER FILMS; PVD-COATINGS; WEAR; FRICTION; BEHAVIOR; ADHESION AB In order to develop coatings to be used in dry machining aluminum alloys, it is necessary to have a better understanding of the factors that influence transfer and adhesion of aluminum to the surfaces of coatings that are potential candidates for this function. In this work, the material transfer and adhesion phenomena between 319 Al alloy samples and different coatings deposited on M2 type steel substrates were examined using a pin-on-disc type wear machine. The coatings included titanium diboride (TiB2), CrN, titanium nitride based compounds, (TiN, TiCN, TiAlN) and uncoated M2 steel discs. The effects of sliding speed, sliding distance, test temperature and working atmosphere were studied. Sliding distances were kept short because the focus of the work was on the initial transfer behavior. The effect of surface roughness was examined using two TiB2 coatings; one with an R-a value of 16 nm and the other with a large Ra of 83 nm. The morphology of sliding tracks was examined using a scanning electron microscope (SEM). With the aid of image analysis software, the SEM images were used to rank the coatings according to the amount of aluminum transferred and the loose debris generated during the tests. In general, the TiB2 and TiCN coatings exhibited the least amount of aluminum transfer on their surfaces compared to the other coatings. TiN and CrN exhibited the largest amount of aluminum transfer, but the amount of loose debris generated on the surfaces of these two coatings was small. Increasing the sliding speed from 0.12 to 0.6 m/s led to a decrease in the amount of aluminum transferred to the surfaces of all the coating tested. Increasing the test temperature to 160 degrees C did not significantly change the amount of aluminum transferred to TiB2 and TiCN coatings. However TiN, TiAlN, CrN and M2 steel picked up significantly less aluminum compared to that at room temperature. When tested under argon atmosphere, all coatings (except TiB2) exhibited a sharp decrease in the amount of aluminum adhered to their surfaces suggesting that the presence of oxygen and water vapor promoted aluminum adhesion to these coatings. The amount of aluminum transfer to the TiB2 coating was a weak function of the inertness of the environment, which was attributed to the high chemical stability of TiB2. Surface roughness played a critical role in aluminum transfer, especially in the early stages of sliding of TiB2. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Windsor, NSERC GM Canada Ind Res Chair Tribol Lightweight, Windsor, ON N9B 3P4, Canada. Gen Motors R&D Ctr, Mat & Proc Lab, Warren, MI 48090 USA. Gen Motors R&D Ctr, Chem & Environm Sci Lab, Warren, MI 48090 USA. Argonne Natl Lab, Energy Technol Div, Argonne, IL 60439 USA. RP Konca, E (reprint author), Univ Windsor, NSERC GM Canada Ind Res Chair Tribol Lightweight, Windsor, ON N9B 3P4, Canada. EM konca@uwindsor.ca RI Cheng, Yang-Tse/B-5424-2012 NR 32 TC 26 Z9 27 U1 1 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 21 PY 2005 VL 200 IS 7 BP 2260 EP 2270 DI 10.1016/j.surfcoat.2004.10.008 PG 11 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 995JO UT WOS:000234096800030 ER PT J AU Goldsmith, J Sutter, E Moore, JJ Mishra, B Crowder, M AF Goldsmith, J Sutter, E Moore, JJ Mishra, B Crowder, M TI Microstructure of amorphous diamond-like carbon thin films and changes during wear SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE diamond-like carbon; wear mechanism; ultra thin film; amorphous; friction ID FRICTIONAL BEHAVIOR; DLC COATINGS; SLIDING WEAR; GRAPHITIZATION; TRIBOLOGY AB Using scanning and transmission electron microscopy, we investigate the microstructure of diamond-like carbon (DLQ thin films deposited in an electron-cyclotron resonance plasma. During pin-on-flat wear experiments, the amorphous DLC films are found to be a source for formation of transfer film and wear track debris with composite microstructure. The transfer film is observed to consist of an amorphous matrix with dispersed microcrystalline and tubular particles. The debris from the wear track represents separated bundles of aligned tubular particles and clusters of microcrystalline particles. The lowering of the coefficient of fiction measured during the wear experiments is related to the formation of the composite transfer film and its stable low value-to the possibility that the randomly oriented tubular particles from the transfer film engage in rolling friction in the process of their organization into aligned bundles. (c) 2005 Elsevier B.V. All rights reserved. C1 Greenleaf Corp, Saegertown, PA 16433 USA. Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. Colorado Sch Mines, Dept Met & Mat Engn, Golden, CO 80401 USA. Ball Aerosp & Technol Corp, Boulder, CO 80301 USA. RP Goldsmith, J (reprint author), Greenleaf Corp, 18695 Greenleaf Dr,POB 1040, Saegertown, PA 16433 USA. EM jgoldsmith@greenleafcorporation.com NR 28 TC 10 Z9 10 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 21 PY 2005 VL 200 IS 7 BP 2386 EP 2390 DI 10.1016/j.surfcoat.2005.04.019 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 995JO UT WOS:000234096800045 ER PT J AU Mahinthakumar, GK Moline, GR Webb, OF AF Mahinthakumar, GK Moline, GR Webb, OF TI An analysis of periodic tracers for subsurface characterization SO WATER RESOURCES RESEARCH LA English DT Article ID CHLORINATED ALIPHATICS; INSITU BIORESTORATION; MODEL SIMULATIONS; TRANSPORT; IMPLEMENTATION; GROUNDWATER; TESTS; PHASE; REMEDIATION; BROMIDE AB [1] This paper investigates the feasibility of periodic tracers (i.e., tracers injected in a periodic waveform) for subsurface characterization using numerical simulations. From a theoretical point of view, periodic tracers offer many advantages over conventional pulse or continuous tracers. For example, periodic tracers are more sensitive to various transport and reaction processes and are less susceptible to corruption by environmental noise. With the recent advances in computer-controlled injection technologies, time is now ripe for investigating the feasibility of these tracers for laboratory and field tracer tests. A series of numerical sensitivity analyses are performed in this study for assessing the sensitivity of these signals for various transport and reaction phenomena in the subsurface. Sensitivity coefficients are calculated and compared for conventional and periodic tracers for various transport phenomena. An inverse modeling case study is performed to evaluate the potential of periodic tracers for detecting the location and concentration of biological active zones. The results indicate that periodic tracers have the potential to perform significantly better than conventional tracers. C1 Fluor Corp, Ctr Chem Technol, Greenville, SC 29607 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. N Carolina State Univ, Dept Civil Construct & Environm Engn, Raleigh, NC 27695 USA. RP Mahinthakumar, GK (reprint author), N Carolina State Univ, Dept Civil Engn, 208 Mann Hall, Raleigh, NC 27695 USA. EM gmkumar@ncsu.edu; oren.webb@fluor.com NR 31 TC 2 Z9 2 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 DEC 21 PY 2005 VL 41 IS 12 AR W12426 DI 10.1029/2005WR004190 PG 13 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 999EB UT WOS:000234370500002 ER PT J AU Sinclair, MB de Boer, MP Corwin, AD AF Sinclair, MB de Boer, MP Corwin, AD TI Long-working-distance incoherent-light interference microscope SO APPLIED OPTICS LA English DT Article ID STELLAR INTERFEROMETRY; DISPERSION; BEAMS; ADHESION; PROFILER; ERROR AB We describe the design and operation of a long-working-distance, incoherent light interference microscope that has been developed to address the growing demand for new microsystem characterization tools. The design of the new microscope is similar to that of a Linnik interference microscope and thus preserves the full working distance of the long-working-distance objectives utilized. However, in contrast to a traditional Linnik microscope, the new microscope does not rely on the use of matched objectives in the sample and the reference arms of the interferometer. An adjustable optical configuration has been devised that allows the total optical path length, wavefront curvature, and dispersion of the reference arm to be matched to the sample arm of the interferometer. The reference arm configuration can be adjusted to provide matching for 5 X, 10 X, and 20 X long-working-distance objectives in the sample arm. In addition to retaining the full working distance of the sample arm objectives, the new design allows interference images to be acquired in situations in which intervening windows are necessary, such as occur with packaged microsystems, microfluidic devices, and cryogenic, vacuum, or environmental chamber studies of microsystem performance. The interference microscope is compatible with phase-shifting interferometry, vertical scanning interferometry, and stroboscopic measurement of dynamic processes. (c) 2005 Optical Society of America. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI de Boer, Maarten/C-1525-2013 OI de Boer, Maarten/0000-0003-1574-9324 NR 27 TC 37 Z9 39 U1 1 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 2005 VL 44 IS 36 BP 7714 EP 7721 DI 10.1364/AO.44.007714 PG 8 WC Optics SC Optics GA 995CT UT WOS:000234078200004 PM 16381517 ER PT J AU Bajt, SA Stearns, DG AF Bajt, SA Stearns, DG TI High-temperature stability multilayers for extreme-ultraviolet condenser optics SO APPLIED OPTICS LA English DT Article ID X-RAY MIRRORS; MO-SI MULTILAYERS; THERMAL-STABILITY; MO/SI MULTILAYERS; BARRIER LAYERS; STRESS; FILMS; RESISTANT; DIFFUSION; W/SI AB We investigate the thermal stability of Mo/SiC multilayer coatings at elevated temperatures. Transmission electron microscopy and x-ray diffraction studies show that, upon annealing, a thermally induced structural relaxation occurs that transforms the polycrystalline Mo and amorphous SiC layers in as-deposited multilayers into an amorphous Mo-Si-C alloy and crystalline SiC, respectively. After this relaxation process is complete, the multilayer is stable at temperatures up to 400 degrees C. (c) 2005 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94040 USA. RP Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94040 USA. EM bajt@llnl.gov RI Bajt, Sasa/G-2228-2010 NR 32 TC 17 Z9 19 U1 0 U2 11 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 DEC 20 PY 2005 VL 44 IS 36 BP 7735 EP 7743 DI 10.1364/AO.44.007735 PG 9 WC Optics SC Optics GA 995CT UT WOS:000234078200007 PM 16381520 ER PT J AU McDonald, P Seljak, U Cen, RY Shih, D Weinberg, DH Burles, S Schneider, DP Schlegel, DJ Bahcall, NA Briggs, JW Brinkmann, J Fukugita, M Ivezic, Z Kent, S Vanden Berk, DE AF McDonald, P Seljak, U Cen, RY Shih, D Weinberg, DH Burles, S Schneider, DP Schlegel, DJ Bahcall, NA Briggs, JW Brinkmann, J Fukugita, M Ivezic, Z Kent, S Vanden Berk, DE TI The linear theory power spectrum from the Ly alpha forest in the Sloan Digital Sky Survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; intergalactic medium; large-scale structure of universe; quasars : absorption lines ID QSO ABSORPTION-SPECTRA; IONIZING-RADIATION FLUCTUATIONS; TEMPERATURE-DENSITY RELATION; INTERGALACTIC MEDIUM; DARK-MATTER; DATA RELEASE; DISK GALAXIES; HIGH-REDSHIFT; LARGE-SAMPLE; EVOLUTION AB We analyze the SDSS Ly alpha forest P-F(k, z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-particle-mesh simulations. We account for the effect of absorbers with damping wings, which leads to an increase in the slope of the linear power spectrum. We break the degeneracy between the mean level of absorption and the linear power spectrum without significant use of external constraints. We infer linear theory power spectrum amplitude Delta(L)(2)(k(p) = 0.009 s km(-1); z(p) = 3.0) 0: 452(-0.057 -0.116)(+0.069 +0.141) and slope n(eff) (k(p), z(p)) = -2.321(-0.047 -0.102)(+0.055 +0.131) (possible systematic errors are included through nuisance parameters in the fit: a factor greater than or similar to 5 smaller errors would be obtained on both parameters if we ignored modeling uncertainties). The errors are correlated and not perfectly Gaussian, so we provide a chi 2 table to accurately describe the results. The result corresponds to sigma(8) = 0.85, n = 0.94 for a Lambda CDM model with Omega(m) = 0.3, Omega(b) = 0.04, and h = 0.7 but is most useful in a combined fit with the CMB. The inferred curvature of the linear power spectrum and the evolution of its amplitude and slope with redshift are consistent with expectations for Lambda CDM models, with the evolution of the slope, in particular, being tightly constrained. We use this information to constrain systematic contamination, e. g., fluctuations in the UV background. This paper should serve as a starting point for more work to refine the analysis, including technical improvements such as increasing the size and number of the hydrodynamic simulations and improvements in the treatment of the various forms of feedback from galaxies and quasars. C1 Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Ohio State Univ, Dept Astron, McPherson Lab 4055, Columbus, OH 43210 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Natl Solar Observ, Sunspot, NM 88349 USA. Apache Point Observ, Sunspot, NM 88349 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP McDonald, P (reprint author), Univ Toronto, Canadian Inst Theoret Astrophys, 60 St George St, Toronto, ON M5S 3H8, Canada. EM pmcdonal@cita.utoronto.ca OI McDonald, Patrick/0000-0001-8346-8394 NR 70 TC 248 Z9 248 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2005 VL 635 IS 2 BP 761 EP 783 DI 10.1086/497563 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 996NZ UT WOS:000234182100003 ER PT J AU Zhang, J Hui, L Stebbins, A AF Zhang, J Hui, L Stebbins, A TI Isolating geometry in weak-lensing measurements SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : halos; galaxies : structure; gravitational lensing; large-scale structure of universe ID LARGE-SCALE STRUCTURE; MASS CORRELATION-FUNCTION; DIGITAL SKY SURVEY; DARK-MATTER; GALAXY ELLIPTICITIES; POWER SPECTRUM; COSMIC SHEAR; ANGULAR-MOMENTUM; COSMOLOGICAL PARAMETERS; INTRINSIC CORRELATION AB Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source scaling can be exploited to effectively measure geometrical distances as a function of redshift and thereby constrain dark energy properties, free of any assumptions about the galaxy-mass/mass power spectrum ( its shape, amplitude, or growth). Such a geometrical method can yield a similar to (0.03-0.07)f(sky)(-1/2) sky measurement on the dark energy abundance and equation of state for a photometric redshift accuracy of Delta z similar to 0.01-0.05 and a survey with a median redshift of similar to 1. While these constraints are weaker than conventional weak-lensing methods, they provide an important consistency check, because the geometrical method carries less theoretical baggage: there is no need to assume any structure formation model ( e. g., CDM). The geometrical method is at the most conservative end of a whole spectrum of methods that obtain smaller error bars by making more restrictive assumptions-we discuss some examples. Our geometrical approach differs from previous investigations along similar lines in three respects. First, the source scaling we propose to use is less demanding on the photometric redshift accuracy. Second, the scaling works for both galaxy-shear and shear-shear correlations. Third, we find that previous studies underestimate the statistical errors associated with similar geometrical methods, the origin of which is discussed. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Zhang, J (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM jz203@columbia.edu; lhui@fnal.gov; stebbins@fnal.gov RI Zhang, Jun/O-3283-2015 NR 59 TC 41 Z9 41 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 DEC 20 PY 2005 VL 635 IS 2 BP 806 EP 820 DI 10.1086/497676 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 996NZ UT WOS:000234182100006 ER PT J AU Barthelmy, SD Cannizzo, JK Gehrels, N Cusumano, G Mangano, V O'Brien, PT Vaughan, S Zhang, B Burrows, DN Campana, S Chincarini, G Goad, MR Kouveliotou, C Kumar, P Meszaros, P Nousek, JA Osborne, JP Panaitescu, A Reeves, JN Sakamoto, T Tagliaferri, G Wijers, RAMJ AF Barthelmy, SD Cannizzo, JK Gehrels, N Cusumano, G Mangano, V O'Brien, PT Vaughan, S Zhang, B Burrows, DN Campana, S Chincarini, G Goad, MR Kouveliotou, C Kumar, P Meszaros, P Nousek, JA Osborne, JP Panaitescu, A Reeves, JN Sakamoto, T Tagliaferri, G Wijers, RAMJ TI Discovery of an afterglow extension of the prompt phase of two gamma-ray bursts observed by Swift SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : individual (GRB 050315, GRB 050319) ID EMISSION; BATSE AB BAT and XRT observations of two recent well-covered GRBs observed by Swift, GRB 050315 and GRB 050319, clearly show a prompt component joining the onset of the afterglow emission. By fitting a power-law form to the gamma-ray spectrum, we extrapolate the time-dependent fluxes measured by BAT, in the energy band 15 350 keV, into the spectral regime observed by XRT, 0.2-10 keV, and examine the functional form of the rate of decay of the two light curves. We find that the BAT and XRT light curves merge to form a unified curve. There is a period of steep decay up to similar to 300 s, followed by a flatter decay. The duration of the steep decay, similar to 100 s in the source frame after correcting for cosmological time dilation, agrees roughly with a theoretical estimate for the deceleration time of the relativistic ejecta as it interacts with circumstellar material. For GRB 050315, the steep decay can be characterized by an exponential form, where the e-folding decay time s ( BAT), tau(e) similar or equal to 24 +/- 2 s e and s ( XRT). For GRB 050319, a power-law decay, -d 1n f/d 1n t = n where n similar or equal to 3 provides a tau(e) similar or equal to 35 +/- 2 e reasonable fit. The early-time X-ray fluxes are consistent with representing the lower energy tail of the prompt emission and provide our first quantitative measure of the decay of the prompt gamma-ray emission over a large dynamic range in flux. The initial steep decay is expected, due to the delayed high-latitude photons from a curved shell of relativistic plasma illuminated only for a short interval. The overall conclusion is that the prompt phase of GRBs remains observable for hundreds of seconds longer than previously thought. C1 NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Ist Astrofis Spaziale & Cosm, INAF, I-90146 Palermo, Italy. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Penn State Univ, Dept Phys, Dept Astron & Astrophys, University Pk, PA 16802 USA. Osserv Astron Brera, INAF, I-23807 Merate, Italy. Univ Milano Bicocca, Dipartimento Fis, I-20126 Milan, Italy. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. CNR, Washington, DC 20418 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, Amsterdam, Netherlands. RP Barthelmy, SD (reprint author), NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012; Barthelmy, Scott/D-2943-2012; OI Cusumano, Giancarlo/0000-0002-8151-1990; Tagliaferri, Gianpiero/0000-0003-0121-0723; Campana, Sergio/0000-0001-6278-1576; Wijers, Ralph/0000-0002-3101-1808 NR 30 TC 56 Z9 57 U1 0 U2 5 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 DEC 20 PY 2005 VL 635 IS 2 BP L133 EP L136 DI 10.1086/499432 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 996OC UT WOS:000234182500006 ER PT J AU Rockefeller, G Fryer, CL Baganoff, FK Melia, F AF Rockefeller, G Fryer, CL Baganoff, FK Melia, F TI The X-ray ridge surrounding Sagittarius A* at the galactic center SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion,accretion disks; black hole physics; galaxy : center; radiation mechanisms : thermal; stars : winds,outflows; X-rays : diffuse background ID EMISSION; CHANDRA; GALAXY AB We present the first detailed simulation of the interaction between the supernova explosion that produced Sgr A East and the wind-swept inner similar to 2 pc region at the Galactic center. The passage of the supernova ejecta through this medium produces an X-ray ridge similar to 9"-15" to the northeast of the supermassive black hole Sagittarius A* (Sgr A*). We show that the morphology and X-ray intensity of this feature match very well with recently obtained Chandra images, and we infer a supernova remnant age of less than 2000 yr. This young age-a factor of 3-4 lower than previous estimates-arises from our inclusion of stellar wind effects in the initial (preexplosion) conditions in the medium. The supernova does not clear out the central similar to 0.2 pc region around Sgr A* and does not significantly alter the gas profile around the central black hole upon passage through the Galactic center. C1 Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Rockefeller, G (reprint author), Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. EM gaber@physics.arizona.edu; fryer@lanl.gov; fkb@space.mit.edu; melia@physics.arizona.edu RI Rockefeller, Gabriel/G-2920-2010 OI Rockefeller, Gabriel/0000-0002-9029-5097 NR 11 TC 14 Z9 14 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2005 VL 635 IS 2 BP L141 EP L144 DI 10.1086/499360 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 996OC UT WOS:000234182500008 ER PT J AU Barsky, D Venclovas, C AF Barsky, D Venclovas, C TI DNA sliding clamps: Just the right twist to load onto DNA SO CURRENT BIOLOGY LA English DT Editorial Material ID CELL NUCLEAR ANTIGEN; POLYMERASE-III HOLOENZYME; ESCHERICHIA-COLI; GAMMA-COMPLEX; ATP BINDING; PCNA; HYDROLYSIS; DYNAMICS; SUBUNIT; MACHINE AB Two recent papers illuminate a key step in DNA sliding clamp loading: one reveals the structure of the PCNA clamp wrapped around DNA still open from being loaded - while the other finds that the clamp may assist this process by forming a right-handed helix upon opening. C1 Lawrence Livermore Natl Lab, Biosci Directorate, Livermore, CA 94550 USA. Inst Biotechnol, LT-02241 Vilnius, Lithuania. RP Barsky, D (reprint author), Lawrence Livermore Natl Lab, Biosci Directorate, 7000 E Ave,L-448, Livermore, CA 94550 USA. NR 20 TC 6 Z9 7 U1 0 U2 0 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0960-9822 J9 CURR BIOL JI Curr. Biol. PD DEC 20 PY 2005 VL 15 IS 24 BP R989 EP R992 DI 10.1016/j.cub.2005.11.047 PG 4 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 998PD UT WOS:000234330300009 PM 16360676 ER PT J AU McNenly, MJ Gallis, MA Boyd, ID AF McNenly, MJ Gallis, MA Boyd, ID TI Empirical slip and viscosity model performance for microscale gas flow SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE rnicroscale gas flow; DSMC; slip models AB For the simple geotnetries of Couette and Poiseuille flows, the velocity profile maintains a similar shape froth continuum to free molecular flow. Therefore, modifications to the fluid viscosity and slip boundary conditions can improve the continuum based Navier-Stokes solution in the non-continuum non-equilibrium regime. In this investigation, the optimal modifications are found by a linear least-squares fit of the Navier-Stokes solution to the non-equilibrium solution obtained using the direct simulation Monte Carlo (DSMC) method. Models are then constructed for the Knudsen number dependence of the viscosity correction and the slip model from a database of DSMC solutions for Couette and Poiseuille flows of argon and nitrogen gas, with Knudsen numbers ranging from 0.01 to 10. Finally, the accuracy of the models is measured for non-equilibrium cases both in and outside the DSMC database. Flows outside the database include: combined Couette and Poiseuille flow, partial wall accommodation, helium gas, and non-zero convective acceleration. The models reproduce the velocity profiles in the DSMC database within an L-2 error norm of 3% for Couette flows and 7% for Poiseuille flows. However, the errors in the model predictions outside the database are LIP to five tunes larger. Copyright (c) 2005 John Wiley & Sots, Ltd. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. RP McNenly, MJ (reprint author), 2012 FXB Bldg,1320 Beal St, Ann Arbor, MI 48109 USA. EM mcnenly@engin.umich.edu NR 12 TC 13 Z9 13 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD DEC 20 PY 2005 VL 49 IS 11 BP 1169 EP 1191 DI 10.1002/fld.1012 PG 23 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 989OL UT WOS:000233683300001 ER PT J AU Asztalos, S AF Asztalos, S TI Heavy meson production at a low-energy photon collider SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA ID COLLISIONS AB A low-energy gamma gamma collider has been discussed in the context of a testbed for a gamma gamma interaction region at the Next Linear Collider (NLC). We consider the production of heavy mesons at such a testbed using Compton-backscattered photons and demonstrate that their production rivals or exceeds those by BELLE, BABAR or LEP where they are produced indirectly via virtual gamma gamma luminosities. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Asztalos, S (reprint author), Lawrence Livermore Natl Lab, 7500 E Ave, Livermore, CA 94551 USA. EM asztalos1@llnl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7294 EP 7305 DI 10.1142/S0217751X05024948 PG 12 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900003 ER PT J AU Brodsky, SJ AF Brodsky, SJ TI High energy photon-photon collisions at a linear collider SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA ID VIRTUAL COMPTON-SCATTERING; DEEP-INELASTIC SCATTERING; GAMMA-GAMMA COLLISIONS; 2-PHOTON COLLISIONS; CROSS-SECTION; QUANTUM CHROMODYNAMICS; PERTURBATIVE QCD; BOSON PRODUCTION; PAIR PRODUCTION; OPTIMAL RENORMALIZATION AB High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the physics capabilities of an e(-)e(+/-) linear collider. The annihilation of two photons produces C = + final states in virtually all angular momentum states. An important physics measurement is the measurement of the Higgs coupling to two photons. The annihilation of polarized photons into the Higgs boson determines its fundamental H-0 -> gamma gamma coupling as well as determining its parity. Other novel two-photon processes include the two-photon production of charged pairs tau(+)tau(-), W+W-, t (t) over bar, and supersymmetric squark and slepton pairs. The one-loop box diagram leads to the production of pairs of neutral particles such as gamma gamma -> Z(0)Z(0), gamma Z(0), and gamma gamma. At the next order one can study Higgstrahlung processes, such as gamma gamma -> W+W- H. Since each photon can be resolved into a W+W- pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying possibly anomalous WW collisions and annihilation. In the case of QCD, each photon can materialize as a quark anti-quark pair which interact via multiple gluon exchange. The diffractive channels in photonphoton collisions allow a novel look at the QCD pomeron and odderon. The C = odderon exchange contribution can be identified by looking at the heavy quark asymmetry. In the case of e gamma -> e' collisions, one can measure the photon structure functions and its various components. Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes which are also important for the analysis of exclusive semi-leptonic and two-body hadronic B-decays. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Brodsky, SJ (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. NR 122 TC 4 Z9 4 U1 2 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X EI 1793-656X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7306 EP 7332 DI 10.1142/S0217751X05031137 PG 27 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900004 ER PT J AU Gronberg, J AF Gronberg, J TI Reaching confidence in photon collider technology SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA DE high energy physics; photon collider AB The technology for a photon collider experiment will ultimately be judged by its ability to deliver sustained luminosity. Attaining high luminosity requires the production of large amounts of laser power and tightly focusing it onto the oncoming electron beam. This paper describes the development and testing program required to have confidence that the laser and optics technology designed for the warm X-band machine will be able to deliver its design luminosity. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gronberg, J (reprint author), Lawrence Livermore Natl Lab, L-050,7000 E Ave, Livermore, CA 94550 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7333 EP 7337 DI 10.1142/S0217751X05031149 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900005 ER PT J AU Larsen, RS AF Larsen, RS TI Revisiting e(-)e(-) switchover in the NLC linac SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA AB This paper is an extension of a talk given in December 1999 which discussed various options for reconfiguring magnets and power sources to convert the NLC to e(-)e(-) operation. At that time three different configurations were examined and a Directional Reversal model was recommended in order to avoid the difficulties of polarity reversal with permanent magnets anticipated in the main.linac at that time. Since permanent magnets axe no longer in the baseline, a Polarity Reversal scheme becomes more attractive. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Larsen, RS (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7358 EP 7364 DI 10.1142/S0217751X05021221 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900008 ER PT J AU Markiewicz, TW Maruyama, T AF Markiewicz, TW Maruyama, T TI Interaction region layout and e+e- pair backgrounds in e-e- collisions SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA DE pairs; linear collider; background; luminosity monitor AB The production of soft e+e- pairs through the interactions of beamstrahlung photons is the major expected background at the next generation of high energy e+e- and e-e- colliders. This process has been simulated and the resulting distributions of particles in the very forward 5-25 mrad pair luminosity monitor are shown. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94039 USA. RP Markiewicz, TW (reprint author), Stanford Linear Accelerator Ctr, POB 20450, Stanford, CA 94039 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7375 EP 7378 DI 10.1142/S0217751X05031186 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900010 ER PT J AU Norem, JH Spencer, JE AF Norem, JH Spencer, JE TI Pin-hole luminosity monitor with feedback SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA DE lasers; damage; luminosity; pin-hole camera; camera obscura; brightness; figure-of-merit; transmissive; reflective modes ID REMEDIES AB Previously, the generalized luminosity L was defined and calculated for all incident channels based on an NLC e(+)e(-) design. Alternatives were then considered to improve the differing beam-beam effects in the e(-)e(-), e gamma and gamma gamma channels. Regardless of the channel, there was a large flux of outgoing, high energy photons that were produced from the beam-beam interaction e.g. beamsstrahlung that needs to be disposed of and whose flux depended on L. One approach to this problem is to consider it a resource and attempt to take advantage of it by disposing of these straight-ahead photons in more useful ways than simply dumping them. While there are many options for monitoring the luminosity, any method that allows feedback and optimization in real time and in a non-intercepting and non-interfering way during normal data taking is extremely important-especially if it provides other capabilities such as high resolution tuning of spot sizes and can be used for all incident channels without essential modifications to their setup. Our "pin-hole" camera appears to be such a device if it can be made to work with high energy photons in ways that are compatible with the many other constraints and demands on space around the interaction region. The basis for using this method is that it has, in principle, the inherent resolution and bandwidth to monitor the very small spot sizes and their stabilities that are required for very high, integrated luminosity. While there are many possible, simultaneous uses of these outgoing photon beams, we limit our discussion to a single, blind, proof-of-principle experiment that was done on the FFTB line at SLAC to certify the concept of a camera obscura for high energy photons. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Stanford Linear Accelerator Ctr, Accelerator Res Dept B, Menlo Pk, CA USA. RP Norem, JH (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM norem@anl.gov; jus@slac.stanford.edu NR 6 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7379 EP 7391 DI 10.1142/S0217751X05031198 PG 13 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900011 ER PT J AU Weidemann, AW AF Weidemann, AW CA E-166 Collaborat TI Polarized positrons at a future linear collider and the final focus test beam SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA DE linear collider; positron sources; polarization; polaximetry ID PAIR PRODUCTION AB Polarized positrons in addition to polarized electrons are a highly desirable feature of future linear e(+)e(-) colliders. The motivation for polarized positrons, and a demonstration experiment for the undulator-based production of polarized positrons are reviewed. This experiment ('E-166') uses the 50 GeV Final Focus Test electron beam at SLAC with a 1 m-long helical undulator to make approximate to 10MeV polarized photons. These photons are then converted in a thin (approximate to 0.5 radiation length) target into positrons (and electrons) with about 50% polarization. C1 Univ S Carolina, Dept Phys, Columbia, SC 29208 USA. RP Weidemann, AW (reprint author), Stanford Linear Accelerator Ctr, POB 20450, Stanford, CA 94309 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7423 EP 7432 DI 10.1142/S0217751X0503123X PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900015 ER PT J AU Woods, M Moffeit, KC Raubenheimer, TO Seryi, A Sramek, C Florimonte, A AF Woods, M Moffeit, KC Raubenheimer, TO Seryi, A Sramek, C Florimonte, A TI Luminosity, energy and polarization studies for the Linear Collider: Comparing e(+)e(-) and e(-)e(-) for NLC and TESLA SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 5th International Workshop on Electron-Electron Interactions at TeV Energies CY DEC 12-14, 2003 CL Santa Cruz, CA DE Linear Collider; luminosity spectrum; polarimetry AB We present results from luminosity, energy and polarization studies at a future Linear Collider. We compare e(+)e(-) and e(-)e(-) modes of operation and consider both NLC and TESLA beam parameter specifications at a center-of-mass energy of 500 GeV. Realistic colliding beam distributions are used, which include dynamic effects of the beam transport from the Damping Rings to the Interaction Point. Beam-beam deflections scans and their impact for beam-based feedbacks are considered. A transverse kink instability is studied, including its impact on determining the luminosity-weighted center-of-mass energy. Polarimetry in the extraction line from the IP is presented, including results on beam distributions at the Compton IP and at the Compton detector. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. RP Woods, M (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 22 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X EI 1793-656X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 20 PY 2005 VL 20 IS 31 SI SI BP 7433 EP 7449 DI 10.1142/S0217751X05031241 PG 17 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BV UT WOS:000234727900016 ER PT J AU Boettger, JC Ray, AK AF Boettger, JC Ray, AK TI Relativistic LCGTO-FF calculations of quantum-size effects in plutonium films SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT 45th Annual Sanibel Symposium CY MAR 05-11, 2005 CL Sanibel Isl, FL SP Univ Florida, Quantum Theory Project DE plutonium; ultra-thin films; LCGTO-FF method; DFT calculations; relativistic corrections ID THIN METAL-FILMS; SURFACE ENERGIES; SLAB CALCULATIONS; ELECTRON-DENSITY; TRANSFORMATION; CRYSTALLINE; MONOLAYERS; HYDROGEN; SOLIDS; LAYERS AB Linear combinations of Gaussian-type orbital-fitting function (LCGTO-FF) calculations have been used to study quantum size effects in the work function and surface energy of unrelaxed ultra-thin (001) films of fcc (delta) plutonium (Pu), up to five layers thick. Relativistic effects are included in the calculations using the second-order Douglas-Kroll-Hess transformation, at the fully- and scalar relativistic levels of approximation, i.e., with and without spin-orbit coupling terms included. In both approximations, the surface energy is found to be rapidly convergent, while the work function exhibits a significant quantum size effect up to the largest thickness considered. The (001) surface energies predicted are notably larger than the (111) surface energies found in similar calculations. The predicted work functions for the (001) and (111) surfaces agree to within the computational uncertainty due to the residual quantum size effect. (c) 2005 Wiley Periodicals, Inc. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Univ Texas, Dept Phys, Arlington, TX 76019 USA. RP Los Alamos Natl Lab, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. EM jn@lanl.gov NR 39 TC 13 Z9 13 U1 0 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0020-7608 EI 1097-461X J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD DEC 20 PY 2005 VL 105 IS 6 BP 564 EP 570 DI 10.1002/qua.20650 PG 7 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 981BW UT WOS:000233063100004 ER PT J AU Shao, XM Fitzgerald, TJ Jacobson, AR AF Shao, XM Fitzgerald, TJ Jacobson, AR TI Reply to comment by Rajeev Thottappillil and Vladimir A. Rakov on ''Radio frequency radiation beam pattern of return strokes: A revisit to theoretical analysis'' SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID FIELDS C1 Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Shao, XM (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, ISR-2,MS D436, Los Alamos, NM 87545 USA. EM xshao@lanl.gov NR 7 TC 5 Z9 5 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 2005 VL 110 IS D24 AR D24106 DI 10.1029/2005JD005889 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 999CA UT WOS:000234365100002 ER PT J AU Goldstein, J Sandel, BR Forrester, WT Thomsen, MF Hairston, MR AF Goldstein, J Sandel, BR Forrester, WT Thomsen, MF Hairston, MR TI Global plasmasphere evolution 22-23 April 2001 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SUBAURORAL POLARIZATION STREAM; MAGNETOSPHERIC ELECTRIC-FIELDS; GEOSYNCHRONOUS ORBIT; PLASMAPAUSE MOTION; MAGNETIC-FIELD; RING CURRENT; EUV IMAGES; DYNAMICS; CONVECTION; MODEL AB [1] The evolution of the plasmasphere during the moderate 22 - 23 April 2001 storm is studied by comparing observed plasmasphere behavior to the predictions of a simulation. The plasmasphere observations include global images from IMAGE EUV and density and flow measurements from LANL MPA. The subjective uncertainty in the EUV plasmapause was found to be 0.2L. Inward plasmapause motion was correlated with southward interplanetary magnetic field ( IMF), with a 27 min delay. The electric ( E) field at the plasmapause was approximately 13% of the solar wind E-field. The observations support the idea that plasmaspheric erosion begins with a partial plasmapause indentation which then gradually widens in magnetic local time (MLT) to encompass the entire nightside. In situ measurements confirm a dayside plume of sunward flowing plasma, and images show that the plume subsequently experienced phases of MLT narrowing and rotation/wrapping. To simulate the event, we employed a test particle representation of the plasmapause using a parametric E-field model that includes corotation and convection from two sources: dayside magnetopause reconnection (DMR) and the subauroral polarization stream ( SAPS). The model captures the phases of plume evolution, and it reproduces the observed plasmapause with maximum ( mean) error < 0.7L (0.24L). The model fails to reproduce important subglobal features ( e. g., a predawn plasmaspheric shoulder) and grossly misplaces the inner edge of the rotating and wrapping plume. SAPS contributes significantly to the duskside flows, but the simulated flows are about 50% smaller than those seen by LANL MPA. The simulated plasmapause E-field is about 70% of the EUV-inferred value. C1 SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78228 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Ctr Space Sci, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. RP Goldstein, J (reprint author), SW Res Inst, Space Sci & Engn Div, 6220 Culebra Rd, San Antonio, TX 78228 USA. EM jgoldstein@swri.edu OI Hairston, Marc/0000-0003-4524-4837 NR 50 TC 41 Z9 41 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 20 PY 2005 VL 110 IS A12 AR A12218 DI 10.1029/2005JA011282 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 999DE UT WOS:000234368100002 ER PT J AU Langry, KC Ratto, TV Rudd, RE McElfresh, MW AF Langry, KC Ratto, TV Rudd, RE McElfresh, MW TI The AFM measured force required to rupture the dithiolate linkage of thioctic acid to gold is less than the rupture force of a simple gold-alkyl thiolate bond SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; ALKANETHIOL MONOLAYERS; THERMAL-STABILITY; MASS-SPECTROMETRY; AU(111) SURFACE; COVALENT BOND; ADSORPTION; DESORPTION; DISULFIDES; MICROSCOPY AB We show with atomic force microscopy that thioctic acid, a spatially constrained system with two sulfur linkages to gold, is less stable to tensile stress than a thiolate with a single attachment to gold. The force required to remove the dithiolate-linked thioctic acid was 0.31 +/- 0.13 nN, whereas the force required to remove a simple thiolate from the gold substrate was 1.05 +/- 10.29 nN. These results suggest that SAMs of densely packed or polypodal thiols may be substantially less stable under tensile stress than previously recognized and that the additional thiolate linkages may not only fail to increase the overall strength of attachment but could actually reduce it. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94551 USA. RP Langry, KC (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 5508, Livermore, CA 94551 USA. EM langry1@llnl.gov OI Rudd, Robert/0000-0002-6632-2681 NR 50 TC 27 Z9 27 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 20 PY 2005 VL 21 IS 26 BP 12064 EP 12067 DI 10.1021/la0513555 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 994WX UT WOS:000234063000003 PM 16342971 ER PT J AU Owen, T Pynn, R Martinez, JS Butler, A AF Owen, T Pynn, R Martinez, JS Butler, A TI Micelle-to-vesicle transition of an iron-chelating microbial surfactant, marinobactin E SO LANGMUIR LA English DT Article ID AMPHIPHILIC SIDEROPHORES; NEUTRON-SCATTERING; MEMBRANE AFFINITY; HOFMEISTER SERIES; MARINE-BACTERIA; METAL-IONS; CONSTANTS AB Small-angle neutron scattering (SANS) and dynamic light scattering (DLS) techniques have been applied to study the self-assembly processes of a microbially produced siderophore, marinobactin E (M-E). M-E is one of a series of marinobactins A-E that facilitate Fe(III) acquisition by the source bacterium through coordination of Fe(III) by the marinobactin headgroup. M-E is a six-amino-acid peptide amphiphile appended by palmitic acid (C-16), and differs only in the nature of the fatty acid moiety from the other marinobactins. ApO-M-E (uncoordinated M-E) assembles to form micelles with an average diameter of 4.0 nm. Upon coordination of one equivalent of Fe(III), the mean micellar diameter of Fe(III)-M-E shrinks to similar to 2.8 nm. However, in the presence of excess Fe(III), Fe(III)-M-E undergoes a micelle-to-vesicle transition (MVT). At a small excess of Fe(III) over Fe(III)-ME (i.e., <1.2 Fe(III)/M-E), a fraction of the Fe(III)-M-E micelles rearrange into similar to 200 nm diameter unilamellar vesicles. At even greater Fe(III)/M-E ratios (e.g., 2-3) multilamellar aggregates begin to emerge, consistent with either multilamellar vesicles or lamellar stacks. The MVT exhibited by M-E may represent a unique mechanism by which marine bacteria may detect and sequester iron required for growth. C1 Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Butler, A (reprint author), Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 USA. EM Butler@chem.ucsb.edu RI Butler, Alison/D-5094-2015 FU NIGMS NIH HHS [GM38130] NR 24 TC 33 Z9 33 U1 1 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 20 PY 2005 VL 21 IS 26 BP 12109 EP 12114 DI 10.1021/la0519352 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 994WX UT WOS:000234063000013 PM 16342981 ER PT J AU Solares, SD Dasgupta, S Schultz, PA Kim, YH Musgrave, CB Goddard, WA AF Solares, SD Dasgupta, S Schultz, PA Kim, YH Musgrave, CB Goddard, WA TI Density functional theory study of the geometry, energetics, and reconstruction process of Si(111) surfaces SO LANGMUIR LA English DT Article ID TRANSMISSION ELECTRON-DIFFRACTION; TOTAL-ENERGY CALCULATIONS; STACKING-FAULT MODEL; 7 X 7; TUNNELING-MICROSCOPY; SILICON; 7X7; GERMANIUM; STRAIN AB We report the structures and energies from first principles density functional calculations of 12 different reconstructed (111) surfaces of silicon, including the 3 x 3 to 9 x 9 dimer-adatom-stacking fault (DAS) structures. These calculations used the Perdew-Burke-Ernzerhof generalized gradient approximation of density functional theory and Gaussian basis functions. We considered fully periodic slabs of various thicknesses. We find that the most stable surface is the DAS 7 x 7 structure, with a surface energy of 1.044 eV/1 x 1 cell (1310 dyn/cm). To analyze the origins of the stability of these systems and to predict energetics for more complex, less-ordered systems, we develop a model in which the surface energy is partitioned into contributions from seven different types of atom environments. This analysis is used to predict the surface energy of larger DAS structures (including their asymptotic behavior for very large unit cells) and to study the energetics of the sequential size change (SSC) model proposed by Shimada and Tochihara for the observed dynamical reconstruction of the Si(111) 1 x 1 structure. We obtain an energy barrier at the 2 x 2 cell size and confirm that the 7 x 7 regular stage of the SSC model (corresponding to the DAS 7 x 7 reconstruction) provides the highest energy reduction per unit cell with respect to the unreconstructed Si(111) 1 x 1 surface. C1 CALTECH, Mat & Proc Simulat Ctr, Pasadena, CA 91125 USA. Sandia Natl Labs, Multiscale Computat Mat Methods Dept, Albuquerque, NM 87185 USA. RP Goddard, WA (reprint author), CALTECH, Mat & Proc Simulat Ctr, Pasadena, CA 91125 USA. EM wag@wag.caltech.edu RI Kim, Yong-Hoon/A-3909-2010 OI Kim, Yong-Hoon/0000-0001-5209-4908 NR 33 TC 10 Z9 10 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 20 PY 2005 VL 21 IS 26 BP 12404 EP 12414 DI 10.1021/la052029s PG 11 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 994WX UT WOS:000234063000053 PM 16343021 ER PT J AU Kwon, YJ James, E Shastri, N Frechet, JMJ AF Kwon, YJ James, E Shastri, N Frechet, JMJ TI In vivo targeting of dendritic cells for activation of cellular immunity using vaccine carriers based on pH-responsive microparticles SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE acid-degradable particle; drug delivery; targeted vaccine ID ANTIGEN PRESENTATION; RECEPTOR DEC-205; MICROGELS; BLOOD AB Activating the immune system to trigger a specific response is a major challenge in vaccine development. In particular, activating sufficient cytotoxic T lymphocyte-mediated cellular immunity, which is crucial for the treatment of many diseases including cancer and AIDS, has proven to be especially challenging. In this study, antigens were encapsulated in acid-degradable polymeric particle carriers to cascade cytotoxic T lymphocyte activation. To target dendritic cells, the most potent antigen-presenting cells, the particle carriers, were further conjugated with monoclonal antibodies. A series of ex vivo and in vivo studies have shown increased receptor-mediated uptake of anti body-conjugated particles by dendritic cells as well as migration of particle-carrying dendritic cells to lymph nodes and stimulation of naive T cells leading to enhanced cellular immune response as confirmed by specific cell lysis and IFN-gamma secretion. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Frechet, JMJ (reprint author), Univ Calif Berkeley, Dept Chem, 718 Latimer Hall, Berkeley, CA 94720 USA. EM frechet@cchem.berkeley.edu OI Frechet, Jean /0000-0001-6419-0163 FU NIBIB NIH HHS [R01 EB005824, R01-EB005824-01] NR 22 TC 107 Z9 111 U1 0 U2 31 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 DEC 20 PY 2005 VL 102 IS 51 BP 18264 EP 18268 DI 10.1073/pnas.0509541102 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 996LB UT WOS:000234174300006 PM 16344458 ER PT J AU Divakaruni, AV Loo, RRO Xie, YM Loo, JA Gober, JW AF Divakaruni, AV Loo, RRO Xie, YM Loo, JA Gober, JW TI The cell-shape protein MreC interacts with extracytoplasmic proteins including cell wall assembly complexes in Caulobacter crescentus SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE MreB; penicillin binding proteins; peptidoglycan ID PENICILLIN-BINDING-PROTEINS; ESCHERICHIA-COLI-CELLS; ACTIN-LIKE PROTEINS; BACILLUS-SUBTILIS; ROD SHAPE; SEPTUM PLACEMENT; OUTER-MEMBRANE; CHROMOSOME; BACTERIA; MORPHOGENESIS AB The bacterial actin homolog, MreB, forms helical cables within the cell that are required for maintenance of a rod shape. These helical structures are thought to be involved in the spatial organization of cell wall (peptidoglycan) synthesizing complexes of penicillinbinding proteins (PBPs). Here, we examined the role of the MreC cell shape protein in this process in Caulobacter crescentus. Subcellular fractionation experiments showed that MreC is a periplasmic protein and, as assayed by immunofluorescence microscopy, adopted helical or banded patterns along the cell length reminiscent of those formed by MreB and PBP2. The pattern of MreC and PBP2 localization remained when MreB cables were disrupted by treatment with the inhibitor A22. However, long-term absence of MreB led to cell shape changes and an eventual loss of MreC localization, suggesting that an independent structure, perhaps an intact peptidoglycan layer, contributes to the MreC localization pattern. Using affinity chromatography with MreC covalently bound to Sepharose, we isolated several PBPs from cell extracts that eluted from the column as heterogeneous complexes. In this same experiment, using mass spectrometry-based protein identification, we identified several outer membrane proteins, including TonB-dependent receptor transport proteins, that interacted with MreC. Imaging live cells containing fusions of these outer membrane proteins to green fluorescent protein showed that they adopted a subcellular localization pattern that was similar to that of MreC. These results suggest that MreC may function in the spatial organization of PBPs as well as other proteins that lie outside the cytoplasmic membrane. C1 Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, DOE Inst Genom & Proteom, Los Angeles, CA 90095 USA. RP Gober, JW (reprint author), Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. EM gober@chem.ucla.edu NR 37 TC 102 Z9 104 U1 0 U2 6 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 20 PY 2005 VL 102 IS 51 BP 18602 EP 18607 DI 10.1073/pnas.0507937102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 996LB UT WOS:000234174300064 PM 16344480 ER PT J AU Brugger, M Khater, H Mayer, S Prinz, A Roesler, S Ulrici, L Vincke, H AF Brugger, M Khater, H Mayer, S Prinz, A Roesler, S Ulrici, L Vincke, H TI Benchmark studies of induced radioactivity produced in LHC materials, part I: specific activities SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analysed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC. C1 CERN, CH-1211 Geneva 23, Switzerland. SLAC, Menlo Pk, CA 94025 USA. RP Mayer, S (reprint author), CERN, CH-1211 Geneva 23, Switzerland. EM Sabine.Mayer@cern.ch NR 6 TC 14 Z9 15 U1 1 U2 7 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 6 EP 11 DI 10.1093/rpd/nci051 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800002 PM 16604585 ER PT J AU Brugger, M Khater, H Mayer, S Prinz, A Roesler, S Ulrici, L Vincke, H AF Brugger, M Khater, H Mayer, S Prinz, A Roesler, S Ulrici, L Vincke, H TI Benchmark studies of induced radioactivity produced in LHC materials, part II: Remanent dose rates SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB A new method to estimate remanent dose rates, to be used with the Monte Carlo code FLUKA, was benchmarked against measurements from an experiment that was performed at the CERN-EU high-energy reference field facility. An extensive collection of samples of different materials were placed downstream of, and laterally to, a copper target, intercepting a positively charged mixed hadron beam with a momentum of 120 GeV c(-1). Emphasis was put on the reduction of uncertainties by taking measures such as careful monitoring of the irradiation parameters, using different instruments to measure dose rates, adopting detailed elemental analyses of the irradiated materials and making detailed simulations of the irradiation experiment. The measured and calculated dose rates are in good agreement. C1 CERN, CH-1211 Geneva 23, Switzerland. SLAC, Menlo Pk, CA 94025 USA. RP Roesler, S (reprint author), CERN, CH-1211 Geneva 23, Switzerland. EM Stefan.Roesler@cern.ch NR 9 TC 18 Z9 19 U1 1 U2 8 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 12 EP 15 DI 10.1093/rpd/nci052 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800003 PM 16604586 ER PT J AU Nakao, N Mokhov, N Yamamoto, K Irie, Y Drozhdin, A AF Nakao, N Mokhov, N Yamamoto, K Irie, Y Drozhdin, A TI MARS14 Monte Carlo simulation for the shielding studies of the J-PARC 3 GeV ring SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB MARS14 Monte Carlo simulations were performed for collimation and shielding studies of the J-PARC 3 GeV synchrotron ring. The beam line module locations in the 348.3 m ring and the curved tunnel sections were described by the 'MAD-MARS beam line builder' tool. A 400 MeV proton beam loss distribution, calculated with the STRUCT code, was used as a 4 kW source term in the collimator region, with 1 kW source terms in the injection and extraction regions at 400 MeV and 3 GeV, respectively. Deep penetration calculations were carried out with good statistics using a newly developed three-dimensional multi-layer technique. Prompt dose-rate distributions were calculated inside and outside the concrete and soil shield up to the ground level. Using the calculation results obtained thus, an effective shielding design was made. C1 High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Nakao, N (reprint author), High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan. EM noriaki.nakao@kek.jp NR 11 TC 2 Z9 2 U1 1 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 85 EP 88 DI 10.1093/rpd/nci036 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800020 PM 16604603 ER PT J AU Mokhov, NV Gudima, KK James, CC Kostin, MA Mashnik, SG Ng, E Ostiguy, JF Rakhno, IL Sierk, AJ Striganov, SI AF Mokhov, NV Gudima, KK James, CC Kostin, MA Mashnik, SG Ng, E Ostiguy, JF Rakhno, IL Sierk, AJ Striganov, SI TI Recent enhancements to the MARS15 code SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID SPALLATION REACTION U-238+P AB The MARS code is under continuous development and has recently undergone substantial improvements that further increase its reliability and predictive power in numerous shielding, accelerator, detector and space applications. The major developments and new features of the MARS15 (2004) version described in this paper concern an extended list of elementary particles and arbitrary heavy ions and their interaction cross sections, inclusive and exclusive nuclear event generators, module for modelling particle electromagnetic interactions, enhanced geometry and histogramming options, improved MAD-MARS Beam Line Builder, enhanced graphical user interface and an MPI-based parallelisation of the code. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Moldavian Acad Sci, Inst Appl Phys, MD-2028 Kishinev, Moldova. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Chicago, IL 60607 USA. Univ Illinois, Urbana, IL 61801 USA. RP Mokhov, NV (reprint author), Fermilab Natl Accelerator Lab, MS 220, Batavia, IL 60510 USA. EM mokhov@fnal.gov NR 20 TC 10 Z9 10 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 99 EP 103 DI 10.1093/rpd/nci106 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800023 PM 16604606 ER PT J AU Mokhov, NV Gudima, KK Mashnik, SG Rakhno, IL Striganov, SI AF Mokhov, NV Gudima, KK Mashnik, SG Rakhno, IL Striganov, SI TI Towards a heavy-ion transport capability in the MARS15 code SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID STOPPING POWER; CROSS-SECTIONS; RANGE AB In order to meet the challenges of new accelerator and space projects and further improve modelling of radiation effects in microscopic objects, heavy-ion interaction and transport physics have been recently incorporated into the MARS15 Monte Carlo code. A brief description of new modules is given in comparison with experimental data. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Moldavian Acad Sci, Inst Appl Phys, MD-2028 Kishinev, Moldova. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Urbana, IL 61801 USA. RP Mokhov, NV (reprint author), Fermilab Natl Accelerator Lab, MS 220, Batavia, IL 60510 USA. EM mokhov@fnal.gov NR 25 TC 6 Z9 6 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 104 EP 108 DI 10.1093/rpd/nci147 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800024 PM 16604607 ER PT J AU Hughes, HG Brown, FB Bull, JS Goorley, JT Little, RC Liu, LC Mashnik, SG Prael, RE Selcow, EC Sierk, AJ Sweezy, JE Zumbro, JD Mokhov, NV Striganov, SI Gudima, KK AF Hughes, HG Brown, FB Bull, JS Goorley, JT Little, RC Liu, LC Mashnik, SG Prael, RE Selcow, EC Sierk, AJ Sweezy, JE Zumbro, JD Mokhov, NV Striganov, SI Gudima, KK TI MCNP5 for proton radiography SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID CHARGED-PARTICLES AB The developmental version of MCNP5 has recently been extended to provide for continuous-energy transport of high-energy protons. This enhancement involves the incorporation of several significant new physics models into the code. Multiple Coulomb scattering is treated with an advanced model that takes account of projectile and nuclear target form factors. In the next version, this model will provide a coupled sampling of both angular deflection and collisional energy loss, including straggling. The proton elastic scattering model is also new, based on recent theoretical work. Charged particle transport in the presence of magnetic fields is accomplished either by using transfer maps from the COSY INFINITY code (in void regions) or by using an algorithm adapted from the MARS code (in void regions or in scattering materials). Work is underway to validate and implement the latest versions of the Cascade-Exciton Model and the Los Alamos Quark-Gluon String Model, which will process inelastic nuclear interactions and generate secondary particles. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Moldavian Acad Sci, Inst Appl Phys, Kishinev, Moldova. RP Hughes, HG (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM hgh@lanl.gov NR 28 TC 8 Z9 8 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 109 EP 112 DI 10.1093/rpd/nci109 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800025 PM 16604608 ER PT J AU Andersen, V Ballarini, F Battistoni, G Cerutti, F Empl, A Fasso, A Ferrari, A Garzelli, MV Ottolenghi, A Paretzke, H Pinsky, L Ranft, J Sala, P Wilson, T Zankl, M AF Andersen, V Ballarini, F Battistoni, G Cerutti, F Empl, A Fasso, A Ferrari, A Garzelli, MV Ottolenghi, A Paretzke, H Pinsky, L Ranft, J Sala, P Wilson, T Zankl, M TI The application of FLUKA to dosimetry and radiation therapy SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB The FLUKA Monte Carlo code has been evolving over the last several decades and is now widely used for radiation shielding calculations. In order to facilitate the use of FLUKA in dosimetry and therapy applications, supporting software has been developed to allow the direct conversion of the output files from standard CT-scans directly into a voxel geometry for transport within FLUKA. Since the CT-scan information essentially contains only the electron density information over the scanned volume, one needs the specific compositions for each voxel individually. We present here the results of a simple algorithm to assign tissues in the human body to one of four categories: soft-tissue, hard-bone, trabecular-bone and porous-lung. In addition, we explore the problem of the pathlength distributions in porous media such as trabecular bone. A mechanism will be implemented within FLUKA to allow for variable multipal fixed density materials to accommodate the pathlength distributions discovered. C1 Univ Houston, Houston, TX 77004 USA. Univ Pavia, I-27100 Pavia, Italy. Univ Milan, I-20122 Milan, Italy. CERN, Geneva, Switzerland. SLAC, Stanford, CA USA. GSF, Neuherberg, Germany. Univ Leipzig, Leipzig, Germany. ETH, Zurich, Switzerland. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Pinsky, L (reprint author), Univ Houston, Houston, TX 77004 USA. EM pinsky@uh.edu RI sala, paola/E-2868-2013; Ballarini, Francesca/J-7293-2013; Zankl, Maria/M-7348-2014; Battistoni, Giuseppe/B-5264-2012 OI sala, paola/0000-0001-9859-5564; Ballarini, Francesca/0000-0002-6629-3382; Zankl, Maria/0000-0003-4743-970X; Battistoni, Giuseppe/0000-0003-3484-1724 NR 4 TC 7 Z9 7 U1 0 U2 7 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 113 EP 117 DI 10.1093/rpd/nci040 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800026 PM 16604609 ER PT J AU Zeitlin, C Guetersloh, S Heilbronn, L Miller, J AF Zeitlin, C Guetersloh, S Heilbronn, L Miller, J TI Shielding and fragmentation studies SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex AB Radiation dosimetry for manned spaced missions depends on the ability to adequately describe the process of high-energy ion transport through many materials. Since the types of possible nuclear interactions are many and complex, transport models are used which depend upon a reliable source of experimental data. To expand the heavy ion database used in the models we have been measuring charge-changing cross sections and fragment production cross sections from heavy-ion interactions in various elementa targets. These include materials flown on space missions such as carbon and aluminium, as well as those important in radiation dosimetry such as hydrogen, nitrogen and water. Measuring heavy-ion fragmentation through these targets also gives us the ability to determine the effectiveness of new materials proposed for shielding such as graphite composites and polyethylene hybrids. Measurement without a target present gives an indication of the level of contamination of the primary beam, which is also important in radiobiology experiments. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Zeitlin, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS74-197, Berkeley, CA 94720 USA. EM cjzeitlin@lbl.gov RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 7 TC 8 Z9 8 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 123 EP 124 DI 10.1093/rpd/nci064 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800028 PM 16604611 ER PT J AU Heilbronn, L Nakamura, T Iwata, Y Kurosawa, T Iwase, H Townsend, LW AF Heilbronn, L Nakamura, T Iwata, Y Kurosawa, T Iwase, H Townsend, LW TI Overview of secondary neutron production relevant to shielding in space SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex ID CARBON; HELIUM; YIELDS; IONS AB An overview of experimental secondary neutron measurements relevant to space-related activities is presented. Stopping target yields and cross section measurements conducted at particle accelerators using heavy ions with energies > 100 MeV per nucleon are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Tohoku Univ, Ctr Cyclotron & Radioisotope, Aoba Ku, Sendai, Miyagi 9808578, Japan. Natl Inst Radiol Sci, Dept Accelerator Phys & Engn, Inage Ku, Chiba 2638555, Japan. Natl Metrol Inst Japan, Quantum Radiat Div, Tsukuba, Ibaraki 3058568, Japan. Gesell Schwerionenforsch mbH, Darmstadt, Germany. Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. RP Heilbronn, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 74-197, Berkeley, CA 94720 USA. EM LHHeilbronn@LBL.gov RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 15 TC 4 Z9 5 U1 0 U2 5 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 140 EP 143 DI 10.1093/rpd/nci033 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800032 PM 16604615 ER PT J AU Stephan, AC Dai, S Wallace, SA Miller, LF AF Stephan, AC Dai, S Wallace, SA Miller, LF TI Modelling of composite neutron scintillators SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex ID THERMAL-NEUTRONS AB Composite neutron scintillators consisting of neutron-insensitive fluorescent dopant particles (e.g. ZnS:Ag) embedded in a matrix material containing isotopes with high neutron cross sections that emit energetic charged particles (e.g. Li-6) are a popular method for neutron detection in a variety of applications. The size and volume doping fraction of the fluorescent dopant particles and the densities of both dopant particles and the matrix material determine the characteristics of the pulse-height spectrum of emitted light and the probability that capture of a neutron will result in scintillation. In this work, we characterise the effects of these parameters for ZnS:Ag particles in a lithiated glass matrix using a Monte Carlo simulation of composite neutron detectors that we have constructed. C1 Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. Neutron Sci Inc, Knoxville, TN 37932 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Stephan, AC (reprint author), Univ Tennessee, Dept Nucl Engn, Pasqua Engn Bldg, Knoxville, TN 37996 USA. EM astephan@utk.edu RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 6 TC 1 Z9 1 U1 0 U2 8 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 165 EP 169 DI 10.1093/rpd/nci121 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800037 PM 16604620 ER PT J AU Wemple, CA Wessol, DE Nigg, DW Cogliati, JJ Milvich, M Fredrickson, CM Perkins, M Harkin, GJ Hartmann-Siantar, CL Lehmann, J Flickinger, T Pletcher, D Yuan, A DeNardo, GL AF Wemple, CA Wessol, DE Nigg, DW Cogliati, JJ Milvich, M Fredrickson, CM Perkins, M Harkin, GJ Hartmann-Siantar, CL Lehmann, J Flickinger, T Pletcher, D Yuan, A DeNardo, GL TI MINERVA: A multi-modality plugin-based radiation therapy treatment planning system SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex ID NEUTRON-CAPTURE THERAPY AB Researchers at the INEEL, MSU, LLNL and UCD have undertaken development of MINERVA, a patient-centric, multi-modal, radiation treatment planning system, which can be used for planning and analysing several radiotherapy modalities, either singly or combined, using common treatment planning tools. It employs an integrated, lightweight plugin architecture to accommodate multi-modal treatment planning using standard interface components. The design also facilitates the future integration of improved planning technologies. The code is being developed with the Java programming language for inter-operability. The MINERVA design includes the image processing, model definition and data analysis modules with a central module to coordinate communication and data transfer. Dose calculation is performed by source and transport plugin modules, which communicate either directly through the database or through MINERVA's openly published, extensible markup language (XML)-based application programmer's interface (API). All internal data are managed by a database management system and can be exported to other applications or new installations through the API data formats. A full computation path has been established for molecular-targeted radiotherapy treatment planning, with additional treatment modalities presently under development. C1 INEEL, Idaho Falls, ID 83415 USA. Montana State Univ, Bozeman, MT 59717 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Med Ctr, Sacramento, CA 95817 USA. RP Wemple, CA (reprint author), INEEL, POB 1625, Idaho Falls, ID 83415 USA. EM cew@inel.gov NR 12 TC 1 Z9 1 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 202 EP 207 DI 10.1093/rpd/nci149 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800044 PM 16604627 ER PT J AU Mokhov, NV Rakhno, IL Striganov, SI Peterson, TJ AF Mokhov, NV Rakhno, IL Striganov, SI Peterson, TJ TI Modelling radiation loads to detectors in a SNAP mission SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex AB In order to investigate the degradation of optical detectors of the Supernova Acceleration Project (SNAP) space mission because of irradiation, a three-dimensional model of the satellite has been developed. A realistic radiation environment at the satellite orbit, including both galactic cosmic rays and cosmic ray trapped in radiation belts, has been taken into account. The modelling has been performed with the MARS14 Monte Carlo code. In a current design, the main contribution to dose accumulated in the photo-detectors is shown to be due to trapped protons. The contribution of primary alpha particles is estimated. Predicted performance degradation for the photodetector for a four-year space mission is 40% and this can be reduced further by means of shielding optimisation. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Urbana, IL 61801 USA. RP Mokhov, NV (reprint author), Fermilab Natl Accelerator Lab, MS 220, Batavia, IL 60510 USA. EM mokhov@fnal.gov NR 9 TC 0 Z9 0 U1 1 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 224 EP 227 DI 10.1093/rpd/nci103 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800049 PM 16604632 ER PT J AU Gallmeier, FX AF Gallmeier, FX TI An improved photo-absorption cross section model for the physics models regime in MCNPX SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex ID RESONANCE REGION; NUCLEI AB The photo-nuclear physics model capabilities utilising the CEM2k model implemented in the MCNPX code were improved > 100 MeV photon energy by basing the photon transport on experimental photo-absorption cross sections of nuclides rather than on free nucleon cross sections. Below 100 MeV, the photo-nuclear physics model now uses isotope-specific giant dipole resonance (GDR) photo-absorption cross sections that are provided to the code in a parameterised form on a data file. Adjustments of the photo-fission cross sections were implemented to match the BOFOD evaluated data through a CEM2k internal parameter. The physics models with these improvements are better equipped to supplement the tabulated data based photo-nuclear MCNPX capability for isotopes with missing tabulated data evaluations especially in the GDR region, and has improved its predictive power at energies above the GDR resonances. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gallmeier, FX (reprint author), Oak Ridge Natl Lab, POB 2008,MS 6474, Oak Ridge, TN 37831 USA. EM fzgallmeier@ornl.gov NR 22 TC 0 Z9 0 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 264 EP 269 DI 10.1093/rpd/nci080 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800058 PM 16604641 ER PT J AU Striganov, SI AF Striganov, SI TI On the theory and simulation of multiple Coulomb scattering of heavy-charged particles SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex AB The Moliere theory of multiple Coulomb scattering is modified to take into account the difference between processes of scattering off atomic nuclei and electrons. A simple analytical expression for angular distribution of charged particles passing through a thick absorber is found. It does not assume any special form for a differential scattering cross section and has a wider range of applicability than a gaussian approximation. A well-known method to simulate multiple Coulomb scatterings is based on treating 'soft' and 'hard' collisions differently. An angular deflection in a large number of 'soft' collisions is sampled using the proposed distribution function, a small number of 'hard' collision are simulated directly. A boundary between 'hard' and 'soft' collisions is defined, providing a precise sampling of a scattering angle (1% level) and a small number of 'hard' collisions. A corresponding simulating module takes into account projectile and nucleus charged distributions and exact kinematics of a projectile-electron interaction. C1 Fermilab Natl Accelerator Lab, Accelerator Div, Batavia, IL 60510 USA. RP Striganov, SI (reprint author), Fermilab Natl Accelerator Lab, Accelerator Div, MS 220, Batavia, IL 60510 USA. EM strigano@fnal.gov NR 7 TC 6 Z9 6 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 293 EP 296 DI 10.1093/rpd/nci107 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800064 PM 16604647 ER PT J AU Kostin, MA Mokhov, NV AF Kostin, MA Mokhov, NV TI Parallelising the MARS15 code with MPI for shielding applications SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex AB The MARS15 Monte Carlo code capabilities to deal with time-consuming deep penetration shielding problems and other computationally tough tasks in accelerator, detector and shielding applications, have been enhanced by a parallel processing option. It has been developed, implemented and tested on the Fermilab Accelerator Division Linux cluster and network of Sun workstations. The code uses a message passing interface MPI. It is scalable and demonstrates good performance. The general architecture of the code, specific uses of message passing and effects of a scheduling on the performance and fault tolerance are described. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kostin, MA (reprint author), Fermilab Natl Accelerator Lab, POB 500,MS 220, Batavia, IL 60510 USA. EM kostin@fnal.gov NR 5 TC 1 Z9 1 U1 1 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 297 EP 300 DI 10.1093/rpd/nci006 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800065 PM 16604648 ER PT J AU Bull, JS Hughes, HG Walstrom, PL Zumbro, JD Mokhov, NV AF Bull, JS Hughes, HG Walstrom, PL Zumbro, JD Mokhov, NV TI Magnetic field tracking with MCNP5 SO RADIATION PROTECTION DOSIMETRY LA English DT Article DE cDNA microarray; dark-rearing; opioid-binding cell adhesion molecule; striate cortex AB With the introduction of continuous-energy heavy charged particle transport in MCNP5, the need for tracking charged particles in a magnetic field becomes increasingly important. Two methods for including magnetic field effects on charged particles are included in the proton transport version of the code. The first technique utilises transfer maps produced by the beam dynamics simulation and analysis code COSY INFINITY. This method is fast and accurate; however, its use is limited to void cells only and to ensembles of particles with a fairly small energy spread. The second technique, particle ray tracing, is based on an algorithm adopted from the MARS transport code. This method can be applied to both void and material cells and is valid over a very large range of particle energies. Results from tracking particles in a quadrupole 'identity lens' using the two techniques are compared. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bull, JS (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM jsbull@lanl.gov NR 11 TC 4 Z9 4 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 307 EP 311 DI 10.1093/rpd/nci048 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800067 ER PT J AU Sweezy, J Hertel, N Lennox, A AF Sweezy, J Hertel, N Lennox, A TI Filter, collimator and moderating material to achieve boron neutron capture enhanced fast neutron therapy SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID GLIOBLASTOMA; IRRADIATION; B-10 AB The combination of fast neutron therapy and boron neutron capture therapy is currently being studied as a possible treatment for some radio-resistant brain tumours. In an attempt to design a boron-enhanced fast neutron therapy beam for the Fermilab Fast Neutron Therapy Facility, the use of moderating material surrounding the patient's head has been investigated. Graphite, polyethylene, water and heavy water were studied as moderating materials, using MCNP. The use of tungsten, iron, lead and bismuth as materials for a small filter and collimator near the patient's head was investigated. Calculations showed that a filter and collimator made of tungsten with a graphite moderator was capable of producing a dose enhancement of 17.3 +/- 0.6% for a 100 mu g g(-1) loading of B-10 for a 5.6 cm diameter beam while delivering 1.5 Gy in 7 min. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Georgia Inst Technol, Neely Nucl Res Ctr, Atlanta, GA 30332 USA. Fermilab Neutron Therapy Facil, Batavia, IL 60510 USA. RP Sweezy, J (reprint author), Los Alamos Natl Lab, Div Appl Phys, X-5,MS F663, Los Alamos, NM 87545 USA. EM j.sweezy@lanl.gov NR 14 TC 5 Z9 5 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 470 EP 474 DI 10.1093/rpd/nci256 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800097 PM 16604680 ER PT J AU Favorite, JA Sanchez, R AF Favorite, JA Sanchez, R TI An inverse method for radiation transport SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID TOMOGRAPHY AB Adjoint functions have been used with forward functions to compute gradients in implicit (iterative) solution methods for inverse problems in optical tomography, geoscience, thermal science and other fields, but only once has this approach been used for inverse solutions to the Boltzmann transport equation. In this paper, this approach is used to develop an inverse method that requires only angle-independent flux measurements, rather than angle-dependent measurements as was done previously. The method is applied to a simplified form of the transport equation that does not include scattering. The resulting procedure uses measured values of gamma-ray fluxes of discrete, characteristic energies to determine interface locations in a multilayer shield. The method was implemented with a Newton-Raphson optimisation algorithm and it worked very well in numerical 1-D spherical test cases. A more sophisticated optimisation method would better exploit the potential of the inverse method. C1 Los Alamos Natl Lab, Dept Appl Phys, Los Alamos, NM 87545 USA. CEA Saclay, SERMA, DM2S, F-91191 Gif Sur Yvette, France. RP Favorite, JA (reprint author), Los Alamos Natl Lab, Dept Appl Phys, X-5,MS F663, Los Alamos, NM 87545 USA. EM fave@lanl.gov NR 9 TC 5 Z9 5 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 482 EP 485 DI 10.1093/rpd/nci204 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800099 PM 16604682 ER PT J AU Devine, RT AF Devine, RT TI Monte Carlo modelling of a simple accident dosemeter SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB A simple dosemeter made of a sulphur tablet, bare and cadmium-covered indium foils and a cadmium-covered copper foil has been modelled using MCNP5. Studies of the model without phantoms or other confounding factors have shown that the cross sections and fluence-to-dose factors generated by the Monte Carlo method agree with those generated by analytic expressions for the high-energy component. In this study, the effect of location on phantoms is studied and an extension of this study to low and intermediate energies is done. The activities expected from exposure to four critical assemblies on phantom is calculated and compared with observations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Devine, RT (reprint author), Los Alamos Natl Lab, HSR 4,POB 1663, Los Alamos, NM 87545 USA. EM devine_r@lanl.gov NR 7 TC 0 Z9 0 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 486 EP 488 DI 10.1093/rpd/nci094 PG 3 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800100 PM 16604683 ER PT J AU Broadhead, BL Wagner, JC AF Broadhead, BL Wagner, JC TI Effective biasing schemes for duct streaming problems SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB The effective use of biasing for the Monte Carlo solution of a void streaming problem is essential to obtaining a reasonable result in a reasonable amount of time. Most general purpose Monte Carlo shielding codes allow for the user to select the particular biasing techniques best oriented to the particular problem of interest. The biasing strategy for void streaming problems many times differs from that of a deep penetration problem. The key in void streaming is to bias particles into the streaming path, whereas in deep penetration problems the biasing is aimed at forcing particles through the shield. Until recently, the biasing scheme in the SCALE SAS4 shielding module was considered inadequate for void streaming problems due to the assumed one-dimensional nature of the automated bias prescription. A modified approach to the automated biasing in SAS4 has allowed for significant gains to be realised in the use of the code for void streaming problems. This paper applies the modified SAS4 procedures to a spent fuel storage cask model with vent ports. The results of the SAS4 analysis are compared with those of the ADVANTG methodology, which is an accelerated version of MCNP. Various options available for the implementation of the SAS4 methodology are reviewed and recommendations offered. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Broadhead, BL (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37830 USA. EM broadheadbl@ornl.gov RI Wagner, John/K-3644-2015 OI Wagner, John/0000-0003-0257-4502 NR 4 TC 2 Z9 2 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 504 EP 507 DI 10.1093/rpd/nci168 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800104 PM 16604687 ER PT J AU Sweezy, J Brown, F Booth, T Chiaramonte, J Preeg, B AF Sweezy, J Brown, F Booth, T Chiaramonte, J Preeg, B TI Automated variance reduction for MCNP using deterministic methods SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB In order to reduce the user's time and the computer time needed to solve deep penetration problems, an automated variance reduction capability has been developed for the MCNP Monte Carlo transport code. This new variance reduction capability developed for MCNP5 employs the PARTISN multigroup discrete ordinates code to generate mesh-based weight windows. The technique of using deterministic methods to generate importance maps has been widely used to increase the efficiency of deep penetration Monte Carlo calculations. The application of this method in MCNP uses the existing mesh-based weight window feature to translate the MCNP geometry into geometry suitable for PARTISN. The adjoint flux, which is calculated with PARTISN, is used to generate mesh-based weight windows for MCNP. Additionally, the MCNP source energy spectrum can be biased based on the adjoint energy spectrum at the source location. This method can also use angle-dependent weight windows. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Schlumberger Doll Res Ctr, Ridgefield, CT 06877 USA. RP Sweezy, J (reprint author), Los Alamos Natl Lab, Div Appl Phys, X-5,MS F663, Los Alamos, NM 87545 USA. EM jsweezy@lanl.gov NR 12 TC 3 Z9 3 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 508 EP 512 DI 10.1093/rpd/nci257 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800105 PM 16604688 ER PT J AU Hertel, NE Sweezy, JE Shultis, JK Warkentin, JK Rose, ZJ AF Hertel, NE Sweezy, JE Shultis, JK Warkentin, JK Rose, ZJ TI A comparison of skyshine computational methods SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID GAMMA; NEUTRON AB A variety of methods employing radiation transport and point-kernel codes have been used to model two skyshine problems. The first problem is a 1 MeV point source of photons on the surface of the earth inside a 2 m tall and 1 m radius silo having black walls. The skyshine radiation downfield from the point source was estimated with and without a 30-cm-thick concrete lid on the silo. The second benchmark problem is to estimate the skyshine radiation downfield from 12 cylindrical canisters emplaced in a low-level radioactive waste trench. The canisters are filled with ion-exchange resin with a representative radionuclide loading, largely (60)Co, (134)Cs and (137)Cs. The solution methods include use of the MCNP code to solve the problem by directly employing variance reduction techniques, the single-scatter point kernel code GGG-GP, the QADMOD-GP point kernel code, the COHORT Monte Carlo code, the NAC International version of the SKYSHINE-III code, the KSU hybrid method and the associated KSU skyshine codes. C1 Georgia Inst Technol, Neely Nucl Res Ctr, Atlanta, GA 30332 USA. Georgia Inst Technol, George W Woodruff Sch Med Engn, Atlanta, GA 30332 USA. Los Alamos Natl Lab, MCNP Dev Grp, Los Alamos, NM 87545 USA. Kansas State Univ, Dept Mech & Nucl Engn, Manhattan, KS 66506 USA. NAC Int, Norcross, GA 30092 USA. RP Hertel, NE (reprint author), Georgia Inst Technol, Neely Nucl Res Ctr, Atlanta, GA 30332 USA. EM nolan.hertel@me.gatech.edu NR 39 TC 3 Z9 3 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 525 EP 533 DI 10.1093/rpd/nci274 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800109 PM 16604692 ER PT J AU Nakao, N Yashima, H Kawai, M Oishi, K Nakashima, H Masumoto, K Matsumura, H Sasaki, S Numajiri, M Sanami, T Wang, Q Toyoda, A Takahashi, K Iijima, K Eda, K Ban, S Hirayama, H Muto, S Nunomiya, T Yonai, S Rasolonjatovo, DRH Terunuma, K Yamauchi, K Sarkar, PK Kim, E Nakamura, T Maruhashi, A AF Nakao, N Yashima, H Kawai, M Oishi, K Nakashima, H Masumoto, K Matsumura, H Sasaki, S Numajiri, M Sanami, T Wang, Q Toyoda, A Takahashi, K Iijima, K Eda, K Ban, S Hirayama, H Muto, S Nunomiya, T Yonai, S Rasolonjatovo, DRH Terunuma, K Yamauchi, K Sarkar, PK Kim, E Nakamura, T Maruhashi, A TI Arrangement of high-energy neutron irradiation field and shielding experiment using 4 m concrete at KENS SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB An irradiation field of high-energy neutrons produced in the forward direction from a thick tungsten target bombarded by 500 MeV protons was arranged at the KENS spallation neutron source facility. In this facility, shielding experiment was performed with an ordinary concrete shield of 4 m thickness assembled in the irradiation room, 2.5 m downstream from the target centre. Activation detectors of bismuth, aluminium, indium and gold were inserted into eight slots inside the shield and attenuations of neutron reaction rates were obtained by measurements of gamma-rays from the activation detectors. A MARS14 Monte Carlo simulation was also performed down to thermal energy, and comparisons between the calculations and measurements show agreements within a factor of 3. This neutron field is useful for studies of shielding, activation and radiation damage of materials for high-energy neutrons, and experimental data are useful to check the accuracies of the transmission and activation calculation codes. C1 High Energy Accelerator Res Org, KEK, Tsukuba, Ibaraki 3050801, Japan. Tohoku Univ, Aoba Ku, Sendai, Miyagi 9808579, Japan. Shimizu Corp, Inst Technol, Koto Ku, Tokyo 1358530, Japan. Japan Atom Energy Res Inst, Ibaraki 3191195, Japan. Natl Inst Radiol Sci, Chiba 2638555, Japan. Univ Tsukuba, Proton Med Res Ctr, Tsukuba, Ibaraki 3058575, Japan. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Nakao, N (reprint author), High Energy Accelerator Res Org, KEK, Tsukuba, Ibaraki 3050801, Japan. EM noriaki.nakao@kek.jp OI Sanami, Toshiya/0000-0003-2255-8008 NR 13 TC 5 Z9 5 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 553 EP 557 DI 10.1093/rpd/nci013 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800114 PM 16604697 ER PT J AU Kodeli, I Hunter, H Sartori, E AF Kodeli, I Hunter, H Sartori, E TI Radiation shielding and dosimetry experiments updates in the SINBAD database SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB The Shielding Integral Benchmark Archive Database (SINBAD) is an internationally established set of radiation shielding and dosimetry data related to experiments relevant in reactor shielding, fusion blanket neutronics and accelerator shielding. In addition to the characterisation of the radiation source, it describes shielding materials and instrumentation and the relevant detectors. The experimental results, be it dose or reaction rates, or unfolded spectra, are presented in tabular ASCII form that can easily be exported to different computer environments for further use. Most sets in SINBAD also contain the computer model used for the interpretation of the experiment and, where available, results from uncertainty analysis. This is an international effort between the Organization for Economic Cooperation and Development, Nuclear Energy Agency Data Bank (http://www.nea.fr/html/databank/) (OECD/NEA Data Bank) and Oak Ridge National Laboratory, Radiation Safety Information Computational Center (http://www-rsicc.ornl.gov/rsic.html) (ORNL/RSICC). Cooperation from many organisations, authors and benchmark analysts have helped SINBAD become a 'living database'-one which involves continuous information updates, preservation and additions of nuclear benchmarks in the areas of fusion, fission and accelerator science and engineering. This paper focuses on the increased comprehensiveness of experiments that have been carried out in recent years and the validation of computer code and cross section library using these experiments. C1 NEA Data Bank, OECD, IAEA, F-92130 Issy Les Moulineaux, France. Oak Ridge Natl Lab, RSICC, Oak Ridge, TN 37831 USA. OECD Nucl Energy Agcy, F-92130 Issy Les Moulineaux, France. RP Kodeli, I (reprint author), NEA Data Bank, OECD, IAEA, F-92130 Issy Les Moulineaux, France. EM ivo.kodeli@oecd.org RI kiaie, robabeh/I-2157-2016 OI kiaie, robabeh/0000-0001-5251-3201 NR 6 TC 6 Z9 6 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 558 EP 561 DI 10.1093/rpd/nci043 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800115 PM 16604698 ER PT J AU Guber, KH Leal, LC Sayer, RO Koehler, PE Valentine, TE Derrien, H Harvey, JA AF Guber, KH Leal, LC Sayer, RO Koehler, PE Valentine, TE Derrien, H Harvey, JA TI Neutron cross section measurements at ORELA for improved nuclear data and their application SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID CAPTURE AB To support the Nuclear Criticality Safety Program, the Oak Ridge Electron Linear Accelerator (ORELA) has been used to measure the total and capture neutron cross sections of several nuclides in the energy range from 100 eV to similar to 600 keV. Concerns about the use of existing cross section data in nuclear criticality calculations have been a prime motivator for the new cross-section measurements. Our new capture cross sections of aluminium, silicon, chlorine, fluorine and potassium in the energy range from 100 eV to 600 keV are substantially different from the cross sections in evaluated nuclear data files of ENDF/B-VI and JENDL-3.2. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Guber, KH (reprint author), Oak Ridge Natl Lab, POB 2008,MS 6354, Oak Ridge, TN 37831 USA. EM guberkh@ornl.gov OI Valentine, Timothy/0000-0001-7495-7348; Koehler, Paul/0000-0002-6717-0771 NR 7 TC 0 Z9 0 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 579 EP 581 DI 10.1093/rpd/nci100 PG 3 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800120 PM 16604703 ER PT J AU Titarenko, YE Batyaev, VF Zhivun, VM Mulambetov, RD Mulambetova, SV Zaitsev, SL Lipatov, KA Barashenkov, VS Mashnik, SG Prael, RE AF Titarenko, YE Batyaev, VF Zhivun, VM Mulambetov, RD Mulambetova, SV Zaitsev, SL Lipatov, KA Barashenkov, VS Mashnik, SG Prael, RE TI Theoretical simulation of residual nuclide products in Pb-208,Pb-207,Pb-206, Pb-NAT and Bi-209 (P,X) reactions at intermediate and high energies SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID PROTON-INDUCED REACTIONS; MODEL; RADIONUCLIDES; NUCLEUS AB The independent and cumulative measured yields of residual products in thin lead and bismuth targets irradiated with 0.04-2.6 GeV protons are compared with results by the LAHET, CEM03, LAQGSM03, INCL+ABLA, CASCADE and YIELDX codes, in order to evaluate the predictive power of the codes in this energy region. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole-mass region of product nuclides and all should be improved further. On the whole, the predictive power of all codes for the data in the fission and fragmentation product regions and, especially, at the borders between spallation and fission and between fission and fragmentation regions is much worse than in the spallation region; therefore, development of better evaporation/fission/fragmentation models is of first priority. C1 Inst Theoret & Expt Phys, Moscow 117259, Russia. Joint Inst Nucl Res Dubna, Dubna, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Inst Theoret & Expt Phys, B Cheremushkinskaya 25, Moscow 117259, Russia. EM Yury.Titarenko@itep.ru NR 25 TC 0 Z9 0 U1 0 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 EI 1742-3406 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 585 EP 591 DI 10.1093/rpd/nci082 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800122 PM 16604705 ER PT J AU Liu, JC Fasso, A Prinz, A Rokni, S Asano, Y AF Liu, JC Fasso, A Prinz, A Rokni, S Asano, Y TI Comparison of synchrotron radiation calculations between analytical codes (STAC8, PHOTON) and Monte Carlo codes (FLUKA, EGS4) SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB STAC8 is a significant improvement upon its predecessor PHOTON and is a valuable analytical code for quick and conservative beamline shielding designs for synchrotron radiation (SR) facilities. In order to check the applicability, accuracy and limitations of STAC8, studies were conducted to compare the results of STAC8 with those of PHOTON with calculations using the FLUKA and EGS4 Monte Carlo codes. Doses and spectra for scattered SR in a few beam-target-shield geometries were calculated, with and without photon linear polarisation effects. Areas for expanding the STAC8 capabilities, for example, features of the mirror-reflected lights and double-Compton light calculations and the use of monochromatic light have been identified. Some of these features have been implemented and benchmarked against Monte Carlo calculations. Reasonable agreements were found between the STAC8 and Monte Carlo calculations. C1 Stanford Linear Accelerator Ctr, Radiat Protect Dept, Stanford, CA 94309 USA. Japan Atom Energy Res Inst, Ctr Synchrotron Radiat, Mikazuki, Hyogo 6795143, Japan. RP Liu, JC (reprint author), Stanford Linear Accelerator Ctr, Radiat Protect Dept, MS 48,POB 20450, Stanford, CA 94309 USA. EM james@slac.stanford.edu NR 10 TC 4 Z9 4 U1 1 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC 20 PY 2005 VL 116 IS 1-4 BP 658 EP 661 DI 10.1093/rpd/nci207 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 004XA UT WOS:000234784800137 PM 16604720 ER PT J AU Chuang, FC Liu, B Wang, CZ Chan, TL Ho, KM AF Chuang, FC Liu, B Wang, CZ Chan, TL Ho, KM TI Global structural optimization of Si magic clusters on the Si(111) 7 x 7 surface SO SURFACE SCIENCE LA English DT Article DE clusters; self-assembly; molecular dynamics; density functional calculations; scanning tunneling microscopy; surface energy; silicon; low index single crystal surfaces ID GENETIC ALGORITHM; DYNAMIC-BEHAVIOR; ELECTRON-GAS; AB-INITIO AB We performed global structural optimization using a genetic algorithm in combination with tight-binding and first-principles calculations to study the structures of the magic clusters on the Si(111) 7 x 7 surface. Our calculations show that the magic cluster observed in scanning tunneling microscopy (STM) experiment [I.S. Hwang, M.S. Ho, T.T. Tsong, Phys. Rev. Lett. 83 (1999) 120] consists of eight Si atoms on the faulted half of the Si(111) 7 x 7 surface. Simulated STM images of our Si magic cluster exhibit a ring-like feature similar to STM experiments. (c) 2005 Elsevier B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, US Dept Energy, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Iowa State Univ, Ames Lab, US Dept Energy, Ames, IA 50011 USA. EM fchuang@iastate.edu; wangcz@ameslab.gov RI Chuang, FengChuan/H-7166-2013 OI Chuang, FengChuan/0000-0003-0351-4253 NR 22 TC 10 Z9 10 U1 0 U2 10 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 DEC 20 PY 2005 VL 598 IS 1-3 BP L339 EP L346 DI 10.1016/j.susc.2005.09.025 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 993JN UT WOS:000233950500001 ER PT J AU Blacksberg, J Hoenk, ME Elliott, ST Holland, SE Nikzad, S AF Blacksberg, J Hoenk, ME Elliott, ST Holland, SE Nikzad, S TI Enhanced quantum efficiency of high-purity silicon imaging detectors by ultralow temperature surface modification using Sb doping SO APPLIED PHYSICS LETTERS LA English DT Article ID HIGH-RESISTIVITY SILICON; P-CHANNEL CCDS; LAYER AB A low temperature process for Sb doping of silicon has been developed as a backsurface treatment for high-purity n-type imaging detectors. Molecular beam epitaxy (MBE) is used to achieve very high dopant incorporation in a thin, surface-confined layer. The growth temperature is kept below 450 degrees C for compatibility with Al-metallized devices. Imaging with MBE-modified 1kx1k charge coupled devices (CCDs) operated in full depletion has been demonstrated. Dark current is comparable to the state-of-the-art process, which requires a high temperature step. Quantum efficiency is improved, especially in the UV, for thin doped layers placed closer to the backsurface. Near 100% internal quantum efficiency has been demonstrated in the ultraviolet for a CCD with a 1.5 nm silicon cap layer. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Blacksberg, J (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM jordana.blacksberg@jpl.nasa.gov; shouleh.nikzad@jpl.nasa.gov NR 11 TC 10 Z9 10 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 DEC 19 PY 2005 VL 87 IS 25 AR 254101 DI 10.1063/1.2149181 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900106 ER PT J AU Ferrando, V Orgiani, P Pogrebnyakov, AV Chen, J Li, Q Redwing, JM Xi, XX Giencke, JE Eom, CB Feng, QR Betts, JB Mielke, CH AF Ferrando, V Orgiani, P Pogrebnyakov, AV Chen, J Li, Q Redwing, JM Xi, XX Giencke, JE Eom, CB Feng, QR Betts, JB Mielke, CH TI High upper critical field and irreversibility field in MgB2 coated-conductor fibers SO APPLIED PHYSICS LETTERS LA English DT Article ID SUPERCONDUCTING MGB2; THIN-FILMS; CRITICAL CURRENTS; TAPES; WIRES; MRI AB We report on structural and superconducting properties of round MgB2 coated-conductor fibers deposited by hybrid physical-chemical vapor deposition on SiC fibers. The coating is polycrystalline and composed of elongated crystallites with dimensions less than 1 mu m in length and 0.2 mu m in width. The pure MgB2 fiber shows a zero-resistance T-c of 39.3 K. The carbon-alloyed fibers show a high upper critical field of 55 T at 1.5 K and a high irreversibility field of 40 T at 1.5 K. The result demonstrates great potential of MgB2 coated conductors for superconducting magnets. (c) 2005 American Institute of Physics. C1 Penn State Univ, Inst Mat Res, University Pk, PA 16802 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. Peking Univ, Dept Phys, Beijing 100871, Peoples R China. Peking Univ, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China. Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. RP Penn State Univ, Inst Mat Res, University Pk, PA 16802 USA. EM xxx4@psu.edu RI Orgiani, Pasquale/E-7146-2013; Eom, Chang-Beom/I-5567-2014 OI Orgiani, Pasquale/0000-0002-1082-9651; NR 26 TC 27 Z9 28 U1 3 U2 9 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 DEC 19 PY 2005 VL 87 IS 25 AR 252509 DI 10.1063/1.2149289 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900067 ER PT J AU Haataja, M Mahon, J Provatas, N Leonard, F AF Haataja, M Mahon, J Provatas, N Leonard, F TI Scaling of domain size during spinodal decomposition: Dislocation discreteness and mobility effects SO APPLIED PHYSICS LETTERS LA English DT Article AB In this letter, we examine the effects of discrete mobile dislocations on spinodal decomposition kinetics in lattice mismatched binary alloys. By employing a novel continuum model, we demonstrate that the effects of dislocation mobility on domain coarsening kinetics can be expressed in a unified manner through a scaling function, describing a crossover from t(1/2) to t(1/3) behavior. (c) 2005 American Institute of Physics. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. McMaster Univ, Dept Mat Sci & Engn, Hamilton, ON L8S 4M1, Canada. McMaster Univ, Brockhouse Inst Mat Res, Hamilton, ON L8S 4M1, Canada. Sandia Natl Labs, Livermore, CA 94551 USA. RP Haataja, M (reprint author), Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. EM mhaataja@princeton.edu NR 6 TC 16 Z9 16 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 19 PY 2005 VL 87 IS 25 AR 251901 DI 10.1063/1.2147732 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900011 ER PT J AU Kim, TH Gangopadhyay, AK Xing, LQ Lee, GW Shen, YT Kelton, KF Goldman, AI Hyers, RW Rogers, JR AF Kim, TH Gangopadhyay, AK Xing, LQ Lee, GW Shen, YT Kelton, KF Goldman, AI Hyers, RW Rogers, JR TI Role of Ti in the formation of Zr-Ti-Cu-Ni-Al glasses SO APPLIED PHYSICS LETTERS LA English DT Article ID SHORT-RANGE ORDER; QUASI-CRYSTALLINE PHASE; METALLIC GLASSES; ALLOYS; BEHAVIOR; OXYGEN AB It has been widely reported that glass formation improves in Zr62Cu20Ni8Al10 alloys when small amounts of Ti are substituted for Zr. Glasses containing greater than 3 at. % Ti crystallize to a metastable icosahedral phase, suggesting that Ti enhances icosahedral short-range order in the liquid/glass, making crystallization more difficult during cooling. However, based on containerless solidification and in situ high-energy synchrotron diffraction studies of electrostatically levitated supercooled liquids of these alloys, we demonstrate that Ti inhibits surface crystallization but neither increases the icosahedral short-range order nor improves glass formation. (c) 2005 American Institute of Physics. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Massachusetts, Amherst, MA 01003 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Kim, TH (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. EM thkim@hbar.wustl.edu RI Hyers, Robert/G-3755-2010 NR 19 TC 10 Z9 10 U1 2 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 19 PY 2005 VL 87 IS 25 AR 251924 DI 10.1063/1.2149368 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900034 ER PT J AU Kursumovic, A Evetts, JE MacManus-Driscoll, JL Maiorov, B Civale, L Wang, H Jia, QX Foltyn, SR AF Kursumovic, A Evetts, JE MacManus-Driscoll, JL Maiorov, B Civale, L Wang, H Jia, QX Foltyn, SR TI High critical current densities in YBa2Cu3O7-x films grown at high rates by hybrid liquid phase epitaxy SO APPLIED PHYSICS LETTERS LA English DT Article ID COATED CONDUCTORS; THIN-FILMS; SUPERCONDUCTORS; VORTICES; SYSTEM AB Liquid-mediated growth of YBa2Cu3O7-x has the potential to be high rate and low cost. However, the reported critical current densities (J(c)) are generally lower than for films deposited by physical vapor deposition processes. We report the deposition of thick high-J(c) films (1.2 MA cm(-2) in self-field) on (001) SrTiO3 by high-rate hybrid liquid phase epitaxy, and show angular-dependent transport critical current as a function of applied field for these films, as well as microstructural measurements by transmission electron microscopy. (c) 2005 American Institute of Physics. C1 Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England. Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Kursumovic, A (reprint author), Univ Cambridge, Dept Mat Sci & Met, Pembroke St, Cambridge CB2 3QZ, England. EM ak237@cus.cam.ac.uk RI Jia, Q. X./C-5194-2008; Wang, Haiyan/P-3550-2014 OI Wang, Haiyan/0000-0002-7397-1209 NR 26 TC 11 Z9 11 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 DEC 19 PY 2005 VL 87 IS 25 AR 252507 DI 10.1063/1.2149975 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900065 ER PT J AU Rosenberg, RA Shenoy, GK Heigl, F Lee, ST Kim, PSG Zhou, XT Sham, TK AF Rosenberg, RA Shenoy, GK Heigl, F Lee, ST Kim, PSG Zhou, XT Sham, TK TI Determination of the local structure of luminescent sites in ZnS nanowires using x-ray excited optical luminescence SO APPLIED PHYSICS LETTERS LA English DT Article ID POROUS SILICON; WURTZITE ZNS; PHOTOLUMINESCENCE; FABRICATION; NANOBELTS; PHOSPHORS; GOLD AB We have monitored the optical luminescence from ZnS nanowires as a function of x-ray energy at the Zn L edge (1022 eV). The x-ray absorption spectrum obtained using the 338 nm, band edge emission as a signal resembles that of the wurtzite form of ZnS, while that obtained using the 430 and 520 nm defect emissions, resembles that of the sphalerite phase. Wurtzite is the dominant phase of the wire, while sphalerite is only found at the end of the wire adjacent to the gold particle used for nucleation and in small, highly localized regions of the wire. Therefore, the present results support the idea that the defect luminescence centers are caused by Au ions (520 nm) and vacancies (430 nm), which are located in regions of sphalerite and show how x-ray excited optical luminescence may be used to probe the local environment of such centers. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Canadian Synchrotron Radiat Facil, Stoughton, WI 53589 USA. City Univ Hong Kong, Dept Phys & Mat Sci, Hong Kong, Hong Kong, Peoples R China. Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. RP Rosenberg, RA (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. EM rar@aps.anl.gov RI Rosenberg, Richard/K-3442-2012 NR 22 TC 21 Z9 23 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 19 PY 2005 VL 87 IS 25 AR 253105 DI 10.1063/1.2143114 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900081 ER PT J AU Schaller, RD Petruska, MA Klimov, VI AF Schaller, RD Petruska, MA Klimov, VI TI Effect of electronic structure on carrier multiplication efficiency: Comparative study of PbSe and CdSe nanocrystals SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM DOTS; SOLAR-CELLS; COLLOIDAL PBSE; OPTICAL GAIN; INTERBAND; EMISSION AB Recently, we demonstrated that PbSe nanocrystal quantum dots can efficiently produce multiple electron-hole pairs (excitons) in response to a single absorbed photon. To address the generality of this carrier-multiplication phenomenon to other materials, we perform a comparative study of multiexciton generation in PbSe and CdSe nanocrystals that have distinctly different electronic structures. We find that both materials exhibit high-efficiency carrier multiplication and the activation threshold is lower in CdSe nanocrystals than in PbSe nanocrystals (similar to 2.5 vs similar to 2.9 energy gaps). Furthermore, the efficiencies of multiexciton generation are nearly identical for both materials despite a vast difference in both energy structures and carrier relaxation behaviors, strongly suggesting that this phenomenon is general to quantum-confined semiconductor nanocrystals. (c) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Klimov, VI (reprint author), Los Alamos Natl Lab, Div Chem, MS-J567, Los Alamos, NM 87545 USA. EM klimov@lanl.gov NR 17 TC 169 Z9 171 U1 2 U2 31 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 DEC 19 PY 2005 VL 87 IS 25 AR 253102 DI 10.1063/1.2142092 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900078 ER PT J AU Shao, L Lin, Y Swadener, JG Lee, JK Jia, QX Wang, YQ Nastasi, M Thompson, PE Theodore, ND Alford, TL Mayer, JW Chen, P Lau, SS AF Shao, L Lin, Y Swadener, JG Lee, JK Jia, QX Wang, YQ Nastasi, M Thompson, PE Theodore, ND Alford, TL Mayer, JW Chen, P Lau, SS TI Strain-facilitated process for the lift-off of a Si layer of less than 20 nm thickness SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON-ON-INSULATOR; CRYSTALLINE SILICON; HYDROGEN AB We report a process for the lift-off of an ultrathin Si layer. By plasma hydrogenation of a molecular-beam-epitaxy-grown heterostructure of Si/Sb-doped-Si/Si, ultrashallow cracking is controlled to occur at the depth of the Sb-doped layer. Prior to hydrogenation, an oxygen plasma treatment is used to induce the formation of a thin oxide layer on the surface of the heterostructure. Chemical etching of the surface oxide layer after hydrogenation further thins the thickness of the separated Si layer to be only 15 nm. Mechanisms of hydrogen trapping and strain-facilitated cracking are discussed. (c) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. USN, Res Lab, Washington, DC 20375 USA. Freescale Semicond Inc, Adv Prod Res & Dev Lab, Tempe, AZ 85284 USA. Arizona State Univ, Dept Chem & Mat Engn, Tempe, AZ 85287 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Shao, L (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM lshao@mailaps.org RI Chen, Peng/H-3384-2012; Jia, Q. X./C-5194-2008; lin, yuan/B-9955-2013 NR 18 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 19 PY 2005 VL 87 IS 25 AR 251907 DI 10.1063/1.2146211 PG 3 WC Physics, Applied SC Physics GA 995QM UT WOS:000234118900017 ER PT J AU Ison, EA Ortiz, CO Abboud, K Boncella, JM AF Ison, EA Ortiz, CO Abboud, K Boncella, JM TI Synthesis and reactivity of molybdenum(IV) complexes with alkyl and aryl isocyanides SO ORGANOMETALLICS LA English DT Article ID RAY CRYSTAL-STRUCTURES; TANTALUM-METHYL BONDS; EFFECTIVE CORE POTENTIALS; MOLECULAR CALCULATIONS; DIALKYL COMPLEXES; OLEFIN COMPLEXES; ARENE COMPLEXES; METAL-CARBON; INSERTION; LIGANDS AB The synthesis and characterization of the bis(isocyanide) complexes (RNC)(2)Mo(NPh)(o-(Me3SiN)(2)C6H4) (2: 2a, R = (BuNC)-Bu-t; 2b, R = 2,6-dimethylphenyl) and the subsequent reactivity of these complexes with excess isocyanide have been reported. An X-ray crystal structure of (RNC)2Mo(NPh)(o-(Me3SiN)2C6H4) (R = 2,6-dimethylphenyl) is reported. Treatment of 2a with excess tent-butyl isocyanide resulted in the formation of the tris(isocyanide) complex ((BuNC)-Bu-t)(3)Mo(NPh)(o-(Me3SiN)(2)C6H4) (3). Complex 3 exists in solution in equilibrium with 2a. Using a two-site exchange mechanism the activation barrier for the dissociative exchange of tBuNC has been calculated. The X-ray crystal structure of ((BuNC)-Bu-t)(3)Mo(NPh)(o-(Me3SiN)(2)C6H4) is reported. Computational studies (ONIOM) performed on 3 reveal that pi conflicts in this complex results in the lengthening of the Mo-N(amido)(cis) bond relative to the Mo-N(amido)(trans) bond. Treatment of 2b with excess 2,6-dimethylphenyl isocyanide results in the slow insertion of the isocyanide ligands into the Mo-N bond of the chelating diamide ligand, resulting in a novel chelating iminocarbamoyl bis(isocyanide) complex, 4. An X-ray crystal structure of 4 is reported. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. Univ Florida, Ctr Catalysis, Gainesville, FL 32611 USA. RP Boncella, JM (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663,Mail Stop J-582, Los Alamos, NM 87545 USA. EM boncella@lanl.gov OI Boncella, James/0000-0001-8393-392X NR 48 TC 6 Z9 6 U1 2 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 DEC 19 PY 2005 VL 24 IS 26 BP 6310 EP 6318 DI 10.1021/om0502436 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 995QJ UT WOS:000234118600006 ER PT J AU Shao, XM Jacobson, AR Fitzgerald, TJ AF Shao, XM Jacobson, AR Fitzgerald, TJ TI Radio frequency radiation beam pattern of lightning return strokes: Inferred from FORTE satellite observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TRANSMISSION-LINE MODEL; ELECTROMAGNETIC-RADIATION; POLARIZATION OBSERVATIONS; DETECTION NETWORK; FIELD; CURRENTS; VHF; INTERFEROMETRY; DERIVATIVES; EMISSIONS AB The fast propagating return stroke is expected to produce a radiation pattern differing from a dipole pattern, with a "correction'' of (1-v cos theta/c)(-1) or the so-called F factor. The FORTE satellite measures lightning Very High Frequency (VHF) radiation at different angles from the up space and offers the first opportunity of examining the F factor. In this report, we studied a group of FORTE-detected lightning events that were also observed by the National Lightning Detection Network (NLDN). NLDN provided the discharges' geolocations and helped to identify the discharge types. During the summers of 1998 and 1999, 25,721 coincident events were found. Among these, 2092 were found to be narrow (<100 ns), VHF-intense and highly polarized bursts and were found to be associated with the beginning of return strokes. Through careful statistical analysis regarding the distributions of the event occurrence, we found that the overall ensemble of events can be considered to have an isotropic pattern in the upper half-space. The subset of the narrow bursts displays a beam pattern that agrees with the F factor at a propagating speed of v=0.75c. The latter is inferred by comparing FORTE observations to a free-space transmission line (TL) model. The analysis shows that the ground does not affect the narrow-burst beam pattern observed from the upper half-space; the source for the narrow burst needs to be a few tens of meters above the surface of the Earth and is apparently associated with the junction point of the attachment process. The physical size of the corresponding discharge is estimated to be less than 20 m. The analysis also suggests that a single upward current is responsible for the observations, rather than a bidirectional current as suggested by others for the attachment process. Similarly, the traveling current source (TCS) model that consists of a simultaneous downward current is found less suitable for the initiation of return strokes. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Shao, XM (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, POB 1663, Los Alamos, NM 87545 USA. EM xshao@lanl.gov NR 45 TC 7 Z9 10 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 17 PY 2005 VL 110 IS D24 AR D24102 DI 10.1029/2005JD006010 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 998BW UT WOS:000234293900005 ER PT J AU Liu, YX Summers, MA Edder, C Frechet, JMJ McGehee, MD AF Liu, YX Summers, MA Edder, C Frechet, JMJ McGehee, MD TI Using resonance energy transfer to improve exciton harvesting in organic-inorganic hybrid photovoltaic cells SO ADVANCED MATERIALS LA English DT Article ID PLASTIC SOLAR-CELLS; CONJUGATED POLYMER; DEVICES; SENSITIZATION; EFFICIENCIES; INTERFACES; SEPARATION; CONVERSION; DIODES; TIO2 AB The effective exciton diffusion length of poly(3-hexylthiophene) (P3HT) can be improved with resonance-energy transfer from P3HT to poly(N-dodecyl-2,5-bis(2'-thienyl)pyrrole-2,1,3-benzothia-diazole) (PTPTB), a low-bandgap polymer, which results in a threefold increase of the photocurrent. Directional resonance energy transfer to the exciton-splitting interface has the potential to overcome a number of limitations associated with exciton transport in polymer photovoltaic cells. C1 Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. RP McGehee, MD (reprint author), Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. EM mmcgehee@stanford.edu OI Frechet, Jean /0000-0001-6419-0163 NR 31 TC 130 Z9 131 U1 2 U2 36 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD DEC 16 PY 2005 VL 17 IS 24 BP 2960 EP + DI 10.1002/adma.200501307 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 000OT UT WOS:000234472400008 ER PT J AU Considine, DB Bergmann, DJ Liu, H AF Considine, DB Bergmann, DJ Liu, H TI Sensitivity of Global Modeling Initiative chemistry and transport model simulations of radon-222 and lead-210 to input meteorological data SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID GENERAL-CIRCULATION MODEL; OBSERVED RADON PROFILES; ATMOSPHERIC TRANSPORT; 3-DIMENSIONAL SIMULATION; NATIONAL CENTER; WET DEPOSITION; DRY DEPOSITION; CLIMATE MODEL; PARAMETERIZATION; AEROSOLS AB We have used the Global Modeling Initiative chemistry and transport model to simulate the radionuclides radon-222 and lead-210 using three different sets of input meteorological information: 1. Output from the Goddard Space Flight Center Global Modeling and Assimilation Office GEOS-STRAT assimilation; 2. Output from the Goddard Institute for Space Studies GISS II' general circulation model; and 3. Output from the National Center for Atmospheric Research MACCM3 general circulation model. We intercompare these simulations with observations to determine the variability resulting from the different meteorological data used to drive the model, and to assess the agreement of the simulations with observations at the surface and in the upper troposphere/ lower stratosphere region. The observational datasets we use are primarily climatologies developed from multiple years of observations. In the upper troposphere/ lower stratosphere region, climatological distributions of lead-210 were constructed from similar to 25 years of aircraft and balloon observations compiled into the US Environmental Measurements Laboratory RANDAB database. Taken as a whole, no simulation stands out as superior to the others. However, the simulation driven by the NCARMACCM3 meteorological data compares better with lead-210 observations in the upper troposphere/ lower stratosphere region. Comparisons of simulations made with and without convection show that the role played by convective transport and scavenging in the three simulations differs substantially. These differences may have implications for evaluation of the importance of very short-lived halogen-containing species on stratospheric halogen budgets. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Natl Inst Aerosp, Hampton, VA USA. RP Considine, DB (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. EM david.b.considine@nasa.gov RI Liu, Hongyu/A-5867-2008; Bergmann, Daniel/F-9801-2011 OI Bergmann, Daniel/0000-0003-4357-6301 NR 51 TC 27 Z9 27 U1 0 U2 11 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1680-7316 EI 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD DEC 16 PY 2005 VL 5 BP 3389 EP 3406 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 993ZR UT WOS:000233999600002 ER PT J AU Macqueen, AJ Phillips, CM Bhalla, N Weiser, P Villeneuve, AM Dernburg, AF AF Macqueen, AJ Phillips, CM Bhalla, N Weiser, P Villeneuve, AM Dernburg, AF TI Chromosome sites play dual roles to establish homologous synapsis during meiosis in C-elegans SO CELL LA English DT Article ID CAENORHABDITIS-ELEGANS; MEIOTIC RECOMBINATION; NUCLEAR REORGANIZATION; GENETIC-ANALYSIS; CROSSING-OVER; X-CHROMOSOME; TRANSLOCATION; PROPHASE; SEGREGATION; MECHANISM AB We have investigated the role of pairing centers (PCs), cis-acting sites required for accurate segregation of homologous chromosomes during meiosis in C. elegans. We find that these sites play two distinct roles that contribute to proper segregation. Chromosomes lacking PCs usually fail to synapse and also lack a synapsis-independent stabilization activity. The presence of a PC on just one copy of a chromosome pair promotes synapsis but does not support synapsis independent pairing stabilization, indicating that these functions are separable. Once initiated, synapsis is highly processive, even between nonhomologous chromosomes of disparate lengths, elucidating how translocations suppress meiotic recombination in C. elegans. These findings suggest a multistep pathway for chromosome synapsis in which PCs impart selectivity and efficiency through a "kinetic proofreading" mechanism. We speculate that concentration of these activities at one region per chromosome may have coevolved with the loss of a point centromere to safeguard karyotype stability. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Stanford Univ, Sch Med, Dept Dev Biol, Stanford, CA 94305 USA. Lawrence Berkeley Lab, Life Sci Div, Berkeley, CA 94720 USA. RP Macqueen, AJ (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. EM afdernburg@lbl.gov RI Phillips, Carolyn/E-8305-2011; OI Phillips, Carolyn/0000-0002-6228-6468; Dernburg, Abby/0000-0001-8037-1079 FU NIGMS NIH HHS [F32 GM067408, F32 GM067408-01A1, F32 GM067408-02, GM067408, R01 GM053804, R01 GM065591, R01 GM53804, R01 GM655591] NR 37 TC 130 Z9 137 U1 0 U2 8 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD DEC 16 PY 2005 VL 123 IS 6 BP 1037 EP 1050 DI 10.1016/j.cell.2005.09.034 PG 14 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 996ME UT WOS:000234177200013 PM 16360034 ER PT J AU Phillips, CM Wong, C Bhalla, N Carlton, PM Weiser, P Meneely, PM Dernburg, AF AF Phillips, CM Wong, C Bhalla, N Carlton, PM Weiser, P Meneely, PM Dernburg, AF TI HIM-8 binds to the X chromosome pairing center and mediates chromosome-specific meiotic synapsis SO CELL LA English DT Article ID CAENORHABDITIS-ELEGANS; C-ELEGANS; SACCHAROMYCES-CEREVISIAE; DROSOPHILA-MELANOGASTER; NUCLEAR REORGANIZATION; HOP1 PROTEIN; RECOMBINATION; MEIOSIS; MUTANTS; EXPANSION AB The him-8 gene is essential for proper meiotic segregation of the X chromosomes in C. elegans. Here we show that loss of him-8 function causes profound X chromosome-specific defects in homolog pairing and synapsis. him-8 encodes a C2H2 zinc-finger protein that is expressed during meiosis and concentrates at a site on the X chromosome known as the meiotic pairing center (PC). A role for HIM-8 in PC function is supported by genetic interactions between PC lesions and him-8 mutations. HIM-8 bound chromosome sites associate with the nuclear envelope (NE) throughout meiotic prophase. Surprisingly, a point mutation in him8 that retains both chromosome binding and NE localization fails to stabilize pairing or promote synapsis. These observations indicate that stabilization of homolog pairing is an active process in which the tethering of chromosome sites to the NE may be necessary but is not sufficient. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Life Sci Div, Berkeley, CA 94720 USA. Haverford Coll, Dept Biol, Haverford, PA 19041 USA. RP Phillips, CM (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. EM afdernburg@lbl.gov RI Phillips, Carolyn/E-8305-2011; OI Phillips, Carolyn/0000-0002-6228-6468; Carlton, Peter/0000-0002-5320-6024; Dernburg, Abby/0000-0001-8037-1079 FU NIGMS NIH HHS [F32 GM067408, F32 GM067408-01A1, F32 GM067408-02, GM067408, R01 GM/CA655591] NR 28 TC 126 Z9 130 U1 1 U2 12 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD DEC 16 PY 2005 VL 123 IS 6 BP 1051 EP 1063 DI 10.1016/j.cell.2005.09.035 PG 13 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 996ME UT WOS:000234177200014 PM 16360035 ER PT J AU Jeong, UY Xia, YN Yin, YD AF Jeong, UY Xia, YN Yin, YD TI Large-scale synthesis of single-crystal CdSe nanowires through a cation-exchange route SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SE-AT-CDSE; SELENIUM NANOWIRES; NANORODS; NANOTUBES; NANOCRYSTALS; NANOSTRUCTURES; TEMPLATES; NETWORKS; AG2SE AB Cation-exchange reaction between Ag+ and Cd2+ was employed to transform single-crystal Ag2Sc nanowires into single-crystal CdSe nanowires as a case study of transformation from one chalcogenide to another one. The CdSe nanowires of similar to 30 nm in diameter had a wurtzite crystal structure and showed preservation of both the morphology and single crystallinity of the Ag2Se nanowires. This synthetic route is useful in producing large quantities of CdSe nanowires with uniform diameters and exceptionally long lengths (> 50 mu m). (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Washington, Dept Chem, Seattle, WA 98195 USA. Lawrence Berkeley Lab, Mol Foundry, Berkeley, CA 94720 USA. RP Xia, YN (reprint author), Univ Washington, Dept Chem, Seattle, WA 98195 USA. EM xia@chem.washington.edu RI Yin, Yadong/D-5987-2011; Xia, Younan/E-8499-2011 OI Yin, Yadong/0000-0003-0218-3042; NR 27 TC 50 Z9 50 U1 2 U2 41 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 DEC 16 PY 2005 VL 416 IS 4-6 BP 246 EP 250 DI 10.1016/j.cplett.2005.09.106 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 993KV UT WOS:000233953900010 ER PT J AU Doucleff, M Malak, LT Pelton, JG Wemmer, DE AF Doucleff, M Malak, LT Pelton, JG Wemmer, DE TI The C-terminal RpoN domain of sigma(54) forms an unpredicted helix-turn-helix motif similar to domains of sigma(70) SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SECONDARY STRUCTURE PREDICTION; MULTIPLE SEQUENCE ALIGNMENT; RNA-POLYMERASE HOLOENZYME; CRYSTAL-STRUCTURE; DNA-BINDING; TRANSCRIPTION FACTOR; ESCHERICHIA-COLI; STRUCTURAL BASIS; METHICILLIN RESISTANCE; FACTOR SIGMA-54 AB The "sigma" subunit of prokaryotic RNA polymerase allows gene-specific transcription initiation. Two sigma families have been identified, sigma(70) and sigma(54), which use distinct mechanisms to initiate transcription and share no detectable sequence homology. Although the sigma(70)-type factors have been well characterized structurally by x-ray crystallography, no high resolution structural information is available for the sigma(54)-type factors. Here we present the NMR-derived structure of the C- terminal domain of sigma(54) from Aquifex aeolicus. This domain (Thr-323 to Gly-389), which contains the highly conserved RpoN box sequence, consists of a poorly structured N-terminal tail followed by a three-helix bundle, which is surprisingly similar to domains of the sigma(70)-type proteins. Residues of the RpoN box, which have previously been shown to be critical for DNA binding, form the second helix of an unpredicted helix-turn-helix motif. The homology of this structure with other DNA-binding proteins, combined with previous biochemical data, suggests how the C- terminal domain of sigma(54) binds to DNA. C1 Lawrence Livermore Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Wemmer, DE (reprint author), Lawrence Livermore Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. EM DEWemmer@lbl.gov FU NIGMS NIH HHS [GM62163] NR 54 TC 25 Z9 25 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 DEC 16 PY 2005 VL 280 IS 50 BP 41530 EP 41536 DI 10.1074/jbc.M509010200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 992EJ UT WOS:000233866900052 PM 16210314 ER PT J AU Gritti, F Guiochon, G AF Gritti, F Guiochon, G TI Critical contribution of nonlinear chromatography to the understanding of retention mechanism in reversed-phase liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Review DE RP-HPLC; retention mechanism; adsorption isotherm; frontal analysis; adsorption energy distribution; adsorption data reproducibility; column heterogeneity; organic modifier; temperature; pressure; ionizable compounds ID OVERLOADED BAND PROFILES; COMPETITIVE ADSORPTION-ISOTHERMS; ADSORBATE-ADSORBATE INTERACTIONS; ESTABLISHED COLUMN EQUILIBRIA; NONPOLAR STATIONARY PHASES; METHANOL-WATER MIXTURES; SOLID-STATE NMR; HOLD-UP VOLUME; ION-PAIR RPLC; SOLUTE RETENTION AB The retention of most compounds in RPLC proceeds through a combination of several independent mechanisms. We review a series of recent studies made on the behavior of several commercial C-18-bonded stationary phases and of the complex, mixed retention mechanisms that were observed in RPLC. These studies are essentially based on the acquisition of adsorption isotherm data, on the modeling, and on the interpretation of these data. Because linear chromatography deals only with the initial slope of the global, overall, or apparent isotherm, it is unable fully to describe the complete adsorption mechanism. It cannot even afford clues as to the existence of several overlaid retention mechanisms. More specifically, it cannot account for the consequences of the surface heterogeneity of the packing material. The acquisition of equilibrium data in a wide concentration range is required for this purpose. Frontal analysis (FA) of selected probes gives data that can be modeled into equilibrium isotherms of these probes and that can also be used to calculate their adsorption or affinity energy distribution (AED). The combination of these data, the detailed study of the best constants of the isotherm model, the determination of the influence of experimental parameters (e.g., buffer pH and pI, temperature) on the isotherm constants provide important clues regarding the heterogeneity of the adsorbent surface and the main properties of the adsorption mechanisms. The comparison of similar data obtained for the adsorption of neutral and ionizable compounds, treated with the same approach, and the investigation of the influence on the thermodynamics of phase equilibrium of the experimental conditions (temperature, average pressure, mobile phase composition. nature of the organic modifier, and, for ionizable compounds, of the ionic strength, the nature, the concentration of the buffer, and its pH) brings further information. This review provides original conclusions regarding retention mechanisms in RPLC. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Dept Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 131 TC 121 Z9 122 U1 1 U2 40 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 DEC 16 PY 2005 VL 1099 IS 1-2 BP 1 EP 42 DI 10.1016/j.chroma.2005.09.082 PG 42 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 995WE UT WOS:000234134400001 PM 16271269 ER PT J AU Miyabe, K Guiochon, G AF Miyabe, K Guiochon, G TI Extrathermodynamic interpretation of retention equilibria in reversed-phase liquid chromatography using octadecylsilyl-silica gels bonded to C-1 and C-18 ligands of different densities SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE ligand density in RPLC; extrathermodynamic relationship; retention mechanism; reversed phase liquid chromatography ID ENTHALPY-ENTROPY COMPENSATION; ALKYL CHAIN-LENGTH; SURFACE-DIFFUSION; HOMOLOGOUS SERIES; MOBILE-PHASE; BEHAVIOR; TEMPERATURE; SELECTIVITY; MECHANISMS; SEPARATION AB The retention behavior on silica gels bonded to C-18 and C-1 alkyl ligands of different densities was studied in reversed-phase liquid chromatography (RPLC) from the viewpoints of two extrathermodynamic relationships, enthalpy-entropy compensation (EEC) and linear free energy relationship (LFER). First, the four tests proposed by Krug et al. were applied to the values of the retention equilibrium constants (K) normalized by the alkyl ligand density. These tests showed that a real EEC of the retention equilibrium originates from substantial physico-chemical effects. Second, we derived a new model based on the EEC to explain the LFER between the retention equilibria under different RPLC conditions. The new model indicates how the slope and intercept of the LFER are correlated to the compensation temperatures derived from the EEC analyses and to several parameters characterizing the molecular contributions to the changes in enthalpy and entropy. Finally, we calculated K under various RPLC conditions from only one original experimental K datum by assuming that the contributions of the C-18 and C-1 ligands to K are additive and that their contributions are proportional to the density of each ligand. The estimated K values are in agreement with the corresponding experimental data, demonstrating that our model is useful to explain the variations of K due to changes in the RPLC conditions. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Toyama Univ, Fac Engn, Toyama 9308555, Japan. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@ion.chem.utk.edu NR 37 TC 8 Z9 8 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD DEC 16 PY 2005 VL 1099 IS 1-2 BP 136 EP 148 DI 10.1016/j.chroma.2005.09.001 PG 13 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 995WE UT WOS:000234134400012 PM 16198359 ER PT J AU Abulencia, A Acosta, D Adelman, J Affolder, T Akimoto, T Albrow, MG Ambrose, D Amerio, S Amidei, D Anastassov, A Anikeev, K Annovi, A Antos, J Aoki, M Apollinari, G Arguin, JF Arisawa, T Artikov, A Ashmanskas, W Attal, A Azfar, F Azzi-Bacchetta, P Azzurri, P Bacchetta, N Bachacou, H Badgett, W Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Bartsch, V Bauer, G Bedeschi, F Behari, S Belforte, S Bellettini, G Bellinger, J Belloni, A Ben-Haim, E Benjamin, D Beretvas, A Beringer, J Berry, T Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Bocci, A Bodek, A Boisvert, V Bolla, G Bolshov, A Bortoletto, D Boudreau, J Bourov, S Boveia, A Brau, B Bromberg, C Brubaker, E Budagov, J Budd, HS Budd, S Burkett, K Busetto, G Bussey, P Byrum, KL Cabrera, S Campanelli, M Campbell, M Canelli, F Canepa, A Carlsmith, D Carosi, R Carron, S Casarsa, M Castro, A Catastini, P Cauz, D Cavalli-Sforza, M Cerri, A Cerrito, L Chang, SH Chapman, J Chen, YC Chertok, M Chiarelli, G Chlachidze, G Chlebana, F Cho, I Cho, K Chokheli, D Chou, JP Chu, PH Chuang, SH Chung, K Chung, WH Chung, YS Ciljak, M Ciobanu, CI Ciocci, MA Clark, A Clark, D Coca, M Connolly, A Convery, ME Conway, J Cooper, B Copic, K Cordelli, M Cortiana, G Cruz, A Cuevas, J Culbertson, R Cyr, D DaRonco, S D'Auria, S D'onofrio, M Dagenhart, D de Barbaro, P De Cecco, S Deisher, A De Lentdecker, G Dell'Orso, M Demers, S Demortier, L Deng, J Deninno, M De Pedis, D Derwent, PF Dionisi, C Dittmann, JR DiTuro, P Dorr, C Dominguez, A Donati, S Donega, M Dong, P Donini, J Dorigo, T Dube, S Ebina, K Efron, J Ehlers, J Erbacher, R Errede, D Errede, S Eusebi, R Fang, HC Farrington, S Fedorko, I Fedorko, WT Feild, RG Feindt, M Fernandez, JP Field, R Flanagan, G Flores-Castillo, LR Foland, A Forrester, S Foster, GW Franklin, M Freeman, JC Fujii, Y Furic, I Gajjar, A Gallinaro, M Galyardt, J Garcia, JE Garcia Sciveres, M Garfinkel, AF Gay, C Gerberich, H Gerchtein, E Gerdes, D Giagu, S Giannetti, P Gibson, A Gibson, K Ginsburg, C Giolo, K Giordani, M Giunta, M Giurgiu, G Glagolev, V Glenzinski, D Gold, M Goldschmidt, N Goldstein, J Gomez, G Gomez-Ceballos, G Goncharov, M Gonzalez, O Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Gresele, A Griffiths, M Grinstein, S Grosso-Pilcher, C Grundler, U Guimaraes da Costa, J Haber, C Hahn, SR Hahn, K Halkiadakis, E Hamilton, A Han, BY Handler, R Happacher, F Hara, K Hare, M Harper, S Harr, RF Harris, RM Hatakeyama, K Hauser, J Hays, C Hayward, H Heijboer, A Heinemann, B Heinrich, J Hennecke, M Herndon, M Heuser, J Hidas, D Hill, CS Hirschbuehl, D Hocker, A Holloway, A Hou, S Houlden, M Hsu, SC Huffman, BT Hughes, RE Huston, J Ikado, K Incandela, J Introzzi, G Iori, M Ishizawa, Y Ivanov, A Iyutin, B James, E Jang, D Jayatilaka, B Jeans, D Jensen, H Jeon, EJ Jones, M Joo, KK Jun, SY Junk, TR Kamon, T Kang, J Karagoz-Unel, M Karchin, PE Kato, Y Kemp, Y Kephart, R Kerzel, U Khotilovich, V Kilminster, B Kim, DH Kim, HS Kim, JE Kim, MJ Kim, MS Kim, SB Kim, SH Kim, YK Kirby, M Kirsch, L Klimenko, S Klute, M Knuteson, B Ko, BR Kobayashi, H Kondo, K Kong, DJ Konigsberg, J Kordas, K Korytov, A Kotwal, AV Kovalev, A Kraus, J Kravchenko, I Kreps, M Kreymer, A Kroll, J Krumnack, N Kruse, M Krutelyov, V Kuhlmann, SE Kusakabe, Y Kwang, S Laasanen, AT Lai, S Lami, S Lammel, S Lancaster, M Lander, RL Lannon, K Lath, A Latino, G Lazzizzera, I Lecci, C LeCompte, T Lee, J Lee, J Lee, SW Lefevre, R Leonardo, N Leone, S Levy, S Lewis, JD Li, K Lin, C Lin, CS Lindgren, M Lipeles, E Liss, TM Lister, A Litvintsev, DO Liu, T Liu, Y Lockyer, NS Loginov, A Loreti, M Loverre, P Lu, RS Lucchesi, D Lujan, P Lukens, P Lungu, G Lyons, L Lys, J Lysak, R Lytken, E Mack, P MacQueen, D Madrak, R Maeshima, K Maksimovic, P Manca, G Margaroli, F Marginean, R Marino, C Martin, A Martin, M Martin, V Martinez, M Maruyama, T Matsunaga, H Mattson, ME Mazini, R Mazzanti, P McFarland, KS McGivern, D McIntyre, P McNamara, P McNulty, R Mehta, A Menzemer, S Menzione, A Merkel, P Mesropian, C Messina, A von der Mey, M Miao, T Miladinovic, N Miles, J Miller, R Miller, JS Mills, C Milnik, M Miquel, R Miscetti, S Mitselmakher, G Miyamoto, A Moggi, N Mohr, B Moore, R Morello, M Movilla Fernandez, P Mulmenstadt, J Mukherjee, A Mulhearn, M Muller, T Mumford, R Murat, P Nachtman, J Nahn, S Nakano, I Napier, A Naumov, D Necula, V Neu, C Neubauer, MS Nielsen, J Nigmanov, T Nodulman, L Norniella, O Ogawa, T Oh, SH Oh, YD Okusawa, T Oldeman, R Orava, R Osterberg, K Pagliarone, C Palencia, E Paoletti, R Papadimitriou, V Papikonomou, A Paramonov, AA Parks, B Pashapour, S Patrick, J Pauletta, G Paulini, M Paus, C Pellett, DE Penzo, A Phillips, TJ Piacentino, G Piedra, J Pitts, K Plager, C Pondrom, L Pope, G Portell, X Poukhov, O Pounder, N Prakoshyn, F Pronko, A Proudfoot, J Ptohos, F Punzi, G Pursley, J Rademacker, J Rahaman, A Rakitin, A Rappoccio, S Ratnikov, F Reisert, B Rekovic, V van Remortel, N Renton, P Rescigno, M Richter, S Rimondi, F Rinnert, K Ristori, L Robertson, WJ Robson, A Rodrigo, T Rogers, E Rolli, S Roser, R Rossi, M Rossin, R Rott, C Ruiz, A Russ, J Rusu, V Ryan, D Saarikko, H Sabik, S Safonov, A Sakumoto, WK Salamanna, G Salto, O Saltzberg, D Sanchez, C Santi, L Sarkar, S Sato, K Savard, P Savoy-Navarro, A Scheidle, T Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Schwarz, T Scodellaro, L Scott, AL Scribano, A Scuri, F Sedov, A Seidel, S Seiya, Y Semenov, A Semeria, F Sexton-Kennedy, L Sfiligoi, I Shapiro, MD Shears, T Shepard, PF Sherman, D Shimojima, M Shochet, M Shon, Y Shreyber, I Sidoti, A Sill, A Sinervo, P Sisakyan, A Sjolin, J Skiba, A Slaughter, AJ Sliwa, K Smirnov, D Smith, JR Snider, FD Snihur, R Soderberg, M Soha, A Somalwar, S Sorin, V Spalding, J Spinella, F Squillacioti, P Stanitzki, M Staveris-Polykalas, A St Denis, R Stelzer, B Stelzer-Chilton, O Stentz, D Strologas, J Stuart, D Suh, JS Sukhanov, A Sumorok, K Sun, H Suzuki, T Taffard, A Tafirout, R Takashima, R Takeuchi, Y Takikawa, K Tanaka, M Tanaka, R Tecchio, M Teng, PK Terashi, K Tether, S Thom, J Thompson, AS Thomson, E Tipton, P Tiwari, V Tkaczyk, S Toback, D Tollefson, K Tomura, T Tonelli, D Tonnesmann, M Torre, S Torretta, D Tourneur, S Trischuk, W Tsuchiya, R Tsuno, S Turini, N Ukegawa, F Unverhau, T Uozumi, S Usynin, D Vacavant, L Vaiciulis, A Vallecorsa, S Varganov, A Vataga, E Velev, G Veramendi, G Veszpremi, V Vickey, T Vidal, R Vila, I Vilar, R Vollrath, I Volobouev, I Wurthwein, F Wagner, P Wagner, RG Wagner, RL Wagner, W Wallny, R Walter, T Wan, Z Wang, MJ Wang, SM Warburton, A Ward, B Waschke, S Waters, D Watts, T Weber, M Wester, WC Whitehouse, B Whiteson, D Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Wittich, P Wolbers, S Wolfe, C Worm, S Wright, T Wu, X Wynne, SM Yagil, A Yamamoto, K Yamaoka, J Yamashita, Y Yang, C Yang, UK Yao, WM Yeh, GP Yoh, J Yorita, K Yoshida, T Yu, I Yu, SS Yun, JC Zanello, L Zanetti, A Zaw, I Zetti, F Zhang, X Zhou, J Zucchelli, S AF Abulencia, A Acosta, D Adelman, J Affolder, T Akimoto, T Albrow, MG Ambrose, D Amerio, S Amidei, D Anastassov, A Anikeev, K Annovi, A Antos, J Aoki, M Apollinari, G Arguin, JF Arisawa, T Artikov, A Ashmanskas, W Attal, A Azfar, F Azzi-Bacchetta, P Azzurri, P Bacchetta, N Bachacou, H Badgett, W Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Bartsch, V Bauer, G Bedeschi, F Behari, S Belforte, S Bellettini, G Bellinger, J Belloni, A Ben-Haim, E Benjamin, D Beretvas, A Beringer, J Berry, T Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Bocci, A Bodek, A Boisvert, V Bolla, G Bolshov, A Bortoletto, D Boudreau, J Bourov, S Boveia, A Brau, B Bromberg, C Brubaker, E Budagov, J Budd, HS Budd, S Burkett, K Busetto, G Bussey, P Byrum, KL Cabrera, S Campanelli, M Campbell, M Canelli, F Canepa, A Carlsmith, D Carosi, R Carron, S Casarsa, M Castro, A Catastini, P Cauz, D Cavalli-Sforza, M Cerri, A Cerrito, L Chang, SH Chapman, J Chen, YC Chertok, M Chiarelli, G Chlachidze, G Chlebana, F Cho, I Cho, K Chokheli, D Chou, JP Chu, PH Chuang, SH Chung, K Chung, WH Chung, YS Ciljak, M Ciobanu, CI Ciocci, MA Clark, A Clark, D Coca, M Connolly, A Convery, ME Conway, J Cooper, B Copic, K Cordelli, M Cortiana, G Cruz, A Cuevas, J Culbertson, R Cyr, D DaRonco, S D'Auria, S D'onofrio, M Dagenhart, D de Barbaro, P De Cecco, S Deisher, A De Lentdecker, G Dell'Orso, M Demers, S Demortier, L Deng, J Deninno, M De Pedis, D Derwent, PF Dionisi, C Dittmann, JR DiTuro, P Dorr, C Dominguez, A Donati, S Donega, M Dong, P Donini, J Dorigo, T Dube, S Ebina, K Efron, J Ehlers, J Erbacher, R Errede, D Errede, S Eusebi, R Fang, HC Farrington, S Fedorko, I Fedorko, WT Feild, RG Feindt, M Fernandez, JP Field, R Flanagan, G Flores-Castillo, LR Foland, A Forrester, S Foster, GW Franklin, M Freeman, JC Fujii, Y Furic, I Gajjar, A Gallinaro, M Galyardt, J Garcia, JE Garcia Sciveres, M Garfinkel, AF Gay, C Gerberich, H Gerchtein, E Gerdes, D Giagu, S Giannetti, P Gibson, A Gibson, K Ginsburg, C Giolo, K Giordani, M Giunta, M Giurgiu, G Glagolev, V Glenzinski, D Gold, M Goldschmidt, N Goldstein, J Gomez, G Gomez-Ceballos, G Goncharov, M Gonzalez, O Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Gresele, A Griffiths, M Grinstein, S Grosso-Pilcher, C Grundler, U Guimaraes da Costa, J Haber, C Hahn, SR Hahn, K Halkiadakis, E Hamilton, A Han, BY Handler, R Happacher, F Hara, K Hare, M Harper, S Harr, RF Harris, RM Hatakeyama, K Hauser, J Hays, C Hayward, H Heijboer, A Heinemann, B Heinrich, J Hennecke, M Herndon, M Heuser, J Hidas, D Hill, CS Hirschbuehl, D Hocker, A Holloway, A Hou, S Houlden, M Hsu, SC Huffman, BT Hughes, RE Huston, J Ikado, K Incandela, J Introzzi, G Iori, M Ishizawa, Y Ivanov, A Iyutin, B James, E Jang, D Jayatilaka, B Jeans, D Jensen, H Jeon, EJ Jones, M Joo, KK Jun, SY Junk, TR Kamon, T Kang, J Karagoz-Unel, M Karchin, PE Kato, Y Kemp, Y Kephart, R Kerzel, U Khotilovich, V Kilminster, B Kim, DH Kim, HS Kim, JE Kim, MJ Kim, MS Kim, SB Kim, SH Kim, YK Kirby, M Kirsch, L Klimenko, S Klute, M Knuteson, B Ko, BR Kobayashi, H Kondo, K Kong, DJ Konigsberg, J Kordas, K Korytov, A Kotwal, AV Kovalev, A Kraus, J Kravchenko, I Kreps, M Kreymer, A Kroll, J Krumnack, N Kruse, M Krutelyov, V Kuhlmann, SE Kusakabe, Y Kwang, S Laasanen, AT Lai, S Lami, S Lammel, S Lancaster, M Lander, RL Lannon, K Lath, A Latino, G Lazzizzera, I Lecci, C LeCompte, T Lee, J Lee, J Lee, SW Lefevre, R Leonardo, N Leone, S Levy, S Lewis, JD Li, K Lin, C Lin, CS Lindgren, M Lipeles, E Liss, TM Lister, A Litvintsev, DO Liu, T Liu, Y Lockyer, NS Loginov, A Loreti, M Loverre, P Lu, RS Lucchesi, D Lujan, P Lukens, P Lungu, G Lyons, L Lys, J Lysak, R Lytken, E Mack, P MacQueen, D Madrak, R Maeshima, K Maksimovic, P Manca, G Margaroli, F Marginean, R Marino, C Martin, A Martin, M Martin, V Martinez, M Maruyama, T Matsunaga, H Mattson, ME Mazini, R Mazzanti, P McFarland, KS McGivern, D McIntyre, P McNamara, P McNulty, R Mehta, A Menzemer, S Menzione, A Merkel, P Mesropian, C Messina, A von der Mey, M Miao, T Miladinovic, N Miles, J Miller, R Miller, JS Mills, C Milnik, M Miquel, R Miscetti, S Mitselmakher, G Miyamoto, A Moggi, N Mohr, B Moore, R Morello, M Movilla Fernandez, P Mulmenstadt, J Mukherjee, A Mulhearn, M Muller, T Mumford, R Murat, P Nachtman, J Nahn, S Nakano, I Napier, A Naumov, D Necula, V Neu, C Neubauer, MS Nielsen, J Nigmanov, T Nodulman, L Norniella, O Ogawa, T Oh, SH Oh, YD Okusawa, T Oldeman, R Orava, R Osterberg, K Pagliarone, C Palencia, E Paoletti, R Papadimitriou, V Papikonomou, A Paramonov, AA Parks, B Pashapour, S Patrick, J Pauletta, G Paulini, M Paus, C Pellett, DE Penzo, A Phillips, TJ Piacentino, G Piedra, J Pitts, K Plager, C Pondrom, L Pope, G Portell, X Poukhov, O Pounder, N Prakoshyn, F Pronko, A Proudfoot, J Ptohos, F Punzi, G Pursley, J Rademacker, J Rahaman, A Rakitin, A Rappoccio, S Ratnikov, F Reisert, B Rekovic, V van Remortel, N Renton, P Rescigno, M Richter, S Rimondi, F Rinnert, K Ristori, L Robertson, WJ Robson, A Rodrigo, T Rogers, E Rolli, S Roser, R Rossi, M Rossin, R Rott, C Ruiz, A Russ, J Rusu, V Ryan, D Saarikko, H Sabik, S Safonov, A Sakumoto, WK Salamanna, G Salto, O Saltzberg, D Sanchez, C Santi, L Sarkar, S Sato, K Savard, P Savoy-Navarro, A Scheidle, T Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Schwarz, T Scodellaro, L Scott, AL Scribano, A Scuri, F Sedov, A Seidel, S Seiya, Y Semenov, A Semeria, F Sexton-Kennedy, L Sfiligoi, I Shapiro, MD Shears, T Shepard, PF Sherman, D Shimojima, M Shochet, M Shon, Y Shreyber, I Sidoti, A Sill, A Sinervo, P Sisakyan, A Sjolin, J Skiba, A Slaughter, AJ Sliwa, K Smirnov, D Smith, JR Snider, FD Snihur, R Soderberg, M Soha, A Somalwar, S Sorin, V Spalding, J Spinella, F Squillacioti, P Stanitzki, M Staveris-Polykalas, A St Denis, R Stelzer, B Stelzer-Chilton, O Stentz, D Strologas, J Stuart, D Suh, JS Sukhanov, A Sumorok, K Sun, H Suzuki, T Taffard, A Tafirout, R Takashima, R Takeuchi, Y Takikawa, K Tanaka, M Tanaka, R Tecchio, M Teng, PK Terashi, K Tether, S Thom, J Thompson, AS Thomson, E Tipton, P Tiwari, V Tkaczyk, S Toback, D Tollefson, K Tomura, T Tonelli, D Tonnesmann, M Torre, S Torretta, D Tourneur, S Trischuk, W Tsuchiya, R Tsuno, S Turini, N Ukegawa, F Unverhau, T Uozumi, S Usynin, D Vacavant, L Vaiciulis, A Vallecorsa, S Varganov, A Vataga, E Velev, G Veramendi, G Veszpremi, V Vickey, T Vidal, R Vila, I Vilar, R Vollrath, I Volobouev, I Wurthwein, F Wagner, P Wagner, RG Wagner, RL Wagner, W Wallny, R Walter, T Wan, Z Wang, MJ Wang, SM Warburton, A Ward, B Waschke, S Waters, D Watts, T Weber, M Wester, WC Whitehouse, B Whiteson, D Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Wittich, P Wolbers, S Wolfe, C Worm, S Wright, T Wu, X Wynne, SM Yagil, A Yamamoto, K Yamaoka, J Yamashita, Y Yang, C Yang, UK Yao, WM Yeh, GP Yoh, J Yorita, K Yoshida, T Yu, I Yu, SS Yun, JC Zanello, L Zanetti, A Zaw, I Zetti, F Zhang, X Zhou, J Zucchelli, S CA CDF Collaboration TI Search for new high-mass particles decaying to Lepton pairs in p(p)over-bar collisions at root s=1.96 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID HADRON COLLIDERS; GAUGE BOSONS AB A search for new particles (X) that decay to electron or muon pairs has been performed using approximately 200 pb(-1) of p (p) over bar collision data at root s =1.96 TeV collected by the CDF II experiment at the Fermilab Tevatron. Limits on sigma(p (p) over bar -> X)BR(X ->center dot center dot) are presented as a function of dilepton invariant mass m(center dot center dot)>150 GeV/c(2), for different spin hypotheses (0, 1, or 2). The limits are approximately 25 fb for m(center dot center dot)>600 GeV/c(2). Lower mass bounds for X from representative models beyond the standard model including heavy neutral gauge bosons are presented. C1 Univ Illinois, Urbana, IL 61801 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Autonoma Barcelona, Inst Fis Altes Energies, E-08193 Barcelona, Spain. Baylor Univ, Waco, TX 76798 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Cantabria, CSIC, Inst Fis Cantabria, E-39005 Santander, Spain. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Joint Inst Nucl Res, RU-141980 Dubna, Russia. Duke Univ, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Harvard Univ, Cambridge, MA 02138 USA. Univ Helsinki, Dept Phys, Div High Energy Phys, FIN-00014 Helsinki, Finland. Helsinki Inst Phys, FIN-00014 Helsinki, Finland. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 305, 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. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Liverpool, Liverpool L69 7ZE, Merseyside, England. UCL, London WC1E 6BT, England. MIT, Cambridge, MA 02139 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. Univ New Mexico, Albuquerque, NM 87131 USA. Northwestern Univ, Evanston, IL 60208 USA. Ohio State Univ, Columbus, OH 43210 USA. Okayama Univ, Okayama 7008530, Japan. Osaka City Univ, Osaka 588, Japan. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova Trento, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Siena & Scuola Normale Super, Ist Nazl Fis Nucl, I-56127 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Univ Roma La Sapienza, Ist Nazl Fis Nucl, Sez Roma 1, I-00185 Rome, Italy. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas A&M Univ, College Stn, TX 77843 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Wayne State Univ, Detroit, MI 48201 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Univ Illinois, Urbana, IL 61801 USA. RI Introzzi, Gianluca/K-2497-2015; Gorelov, Igor/J-9010-2015; Prokoshin, Fedor/E-2795-2012; Leonardo, Nuno/M-6940-2016; Canelli, Florencia/O-9693-2016; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; Lysak, Roman/H-2995-2014; Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; Russ, James/P-3092-2014; Lazzizzera, Ignazio/E-9678-2015; Cabrera Urban, Susana/H-1376-2015; Cavalli-Sforza, Matteo/H-7102-2015; Garcia, Jose /H-6339-2015; ciocci, maria agnese /I-2153-2015; Muelmenstaedt, Johannes/K-2432-2015; Lancaster, Mark/C-1693-2008; Ruiz, Alberto/E-4473-2011; messina, andrea/C-2753-2013; Annovi, Alberto/G-6028-2012; Robson, Aidan/G-1087-2011; De Cecco, Sandro/B-1016-2012; St.Denis, Richard/C-8997-2012; Chiarelli, Giorgio/E-8953-2012; Azzi, Patrizia/H-5404-2012; manca, giulia/I-9264-2012; Amerio, Silvia/J-4605-2012; Punzi, Giovanni/J-4947-2012; Ivanov, Andrew/A-7982-2013; Connolly, Amy/J-3958-2013 OI Introzzi, Gianluca/0000-0002-1314-2580; Gorelov, Igor/0000-0001-5570-0133; Prokoshin, Fedor/0000-0001-6389-5399; Leonardo, Nuno/0000-0002-9746-4594; Canelli, Florencia/0000-0001-6361-2117; Warburton, Andreas/0000-0002-2298-7315; Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Russ, James/0000-0001-9856-9155; Lazzizzera, Ignazio/0000-0001-5092-7531; ciocci, maria agnese /0000-0003-0002-5462; Muelmenstaedt, Johannes/0000-0003-1105-6678; Ruiz, Alberto/0000-0002-3639-0368; Annovi, Alberto/0000-0002-4649-4398; Chiarelli, Giorgio/0000-0001-9851-4816; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Ivanov, Andrew/0000-0002-9270-5643; NR 21 TC 42 Z9 42 U1 1 U2 12 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 DEC 16 PY 2005 VL 95 IS 25 AR 252001 DI 10.1103/PhysRevLett.95.252001 PG 7 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500014 PM 16384448 ER PT J AU Al-Hassanieh, KA Busser, CA Martins, GB Dagotto, E AF Al-Hassanieh, KA Busser, CA Martins, GB Dagotto, E TI Electron transport through a molecular conductor with center-of-mass motion SO PHYSICAL REVIEW LETTERS LA English DT Article ID KONDO RESONANCE; QUANTUM DOTS; TRANSISTOR; TRANSPARENCY; OSCILLATIONS; ATOM AB The linear conductance of a molecular conductor oscillating between two metallic leads is investigated numerically both for Hubbard interacting and noninteracting electrons. The molecule-leads tunneling barriers depend on the molecule displacement from its equilibrium position. The results present an interesting interference which leads to a conductance dip at the electron-hole symmetry point that could be experimentally observable. It is shown that this dip is caused by the destructive interference between the purely electronic and phonon-assisted tunneling channels, which are found to carry opposite phases. When an internal vibrational mode is also active, the electron-hole symmetry is broken but a Fano-like interference is still observed. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Oakland Univ, Dept Phys, Rochester, MI 48309 USA. RP Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Busser, Carlos/K-1017-2014; Martins, George/C-9756-2012 OI Busser, Carlos/0000-0002-0353-7490; Martins, George/0000-0001-7846-708X NR 36 TC 18 Z9 18 U1 1 U2 6 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 DEC 16 PY 2005 VL 95 IS 25 AR 256807 DI 10.1103/PhysRevLett.95.256807 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500062 PM 16384495 ER PT J AU Atkins, R Benbow, W Berley, D Blaufuss, E Coyne, DG DeYoung, T Dingus, BL Dorfan, DE Ellsworth, RW Fleysher, L Fleysher, R Gisler, G Gonzalez, MM Goodman, JA Haines, TJ Hays, E Hoffman, CM Kelley, LA Lansdell, CP Linnemann, JT McEnery, JE Miller, RS Mincer, AI Morales, MF Nemethy, P Noyes, D Ryan, JM Samuelson, FW Parkinson, PMS Shoup, A Sinnis, G Smith, AJ Sullivan, GW Williams, DA Wilson, ME Xu, XW Yodh, GB AF Atkins, R Benbow, W Berley, D Blaufuss, E Coyne, DG DeYoung, T Dingus, BL Dorfan, DE Ellsworth, RW Fleysher, L Fleysher, R Gisler, G Gonzalez, MM Goodman, JA Haines, TJ Hays, E Hoffman, CM Kelley, LA Lansdell, CP Linnemann, JT McEnery, JE Miller, RS Mincer, AI Morales, MF Nemethy, P Noyes, D Ryan, JM Samuelson, FW Parkinson, PMS Shoup, A Sinnis, G Smith, AJ Sullivan, GW Williams, DA Wilson, ME Xu, XW Yodh, GB TI Evidence for TeV gamma-ray emission from a region of the galactic plane SO PHYSICAL REVIEW LETTERS LA English DT Article ID AIR-SHOWER ARRAY; SUPERNOVA-REMNANTS; CRAB-NEBULA; RADIATION; ASTRONOMY; SEARCH AB Gamma-ray emission from a narrow band at the galactic equator has previously been detected up to 30 GeV. We report evidence for a TeV gamma-ray signal from a region of the galactic plane by Milagro, a large-field-of-view water Cherenkov detector for extensive air showers. An excess with a significance of 4.5 standard deviations has been observed from the region of galactic longitude l is an element of(40 degrees,100 degrees) and latitude parallel to b parallel to < 5 degrees. Under the assumption of a simple power law spectrum, with no cutoff in the EGRET-Milagro energy range, the measured integral flux is phi(gamma)(> 3.5 TeV)=(6.4 +/- 1.4 +/- 2.1)x10(-11) cm(-2) s(-1) sr(-1). This flux is consistent with an extrapolation of the EGRET spectrum between 1 and 30 GeV in this galactic region. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Los Alamos Natl Lab, Grp P 23, Los Alamos, NM 87545 USA. George Mason Univ, Dept Phys & Astron, Fairfax, VA 22030 USA. NYU, Dept Phys, New York, NY 10003 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RP Atkins, R (reprint author), Univ Utah, Dept Phys, 115 South 1400 East, Salt Lake City, UT 84112 USA. RI Hays, Elizabeth/D-3257-2012; OI Dingus, Brenda/0000-0001-8451-7450 NR 24 TC 49 Z9 50 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 DEC 16 PY 2005 VL 95 IS 25 AR 251103 DI 10.1103/PhysRevLett.95.251103 PG 5 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500011 PM 16384445 ER PT J AU Ginocchio, JN AF Ginocchio, JN TI U(3) and pseudo-U(3) symmetry of the relativistic harmonic oscillator SO PHYSICAL REVIEW LETTERS LA English DT Article ID PSEUDOSPIN SYMMETRY; NUCLEI AB We show that a Dirac Hamiltonian with equal scalar and vector harmonic oscillator potentials has not only a spin symmetry but a U(3) symmetry and that a Dirac Hamiltonian with scalar and vector harmonic oscillator potentials equal in magnitude but opposite in sign has not only a pseudospin symmetry but a pseudo-U(3) symmetry. We derive the generators of the symmetry for each case. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ginocchio, JN (reprint author), Los Alamos Natl Lab, Div Theoret, MS B283, Los Alamos, NM 87545 USA. NR 11 TC 72 Z9 74 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 DEC 16 PY 2005 VL 95 IS 25 AR 252501 DI 10.1103/PhysRevLett.95.252501 PG 3 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500018 PM 16384452 ER PT J AU Heidenreich, BJ Elliott, OT Charney, ND Virgien, KA Bridges, AW McKeon, MA Peck, SK Krause, D Gordon, JE Hunter, LR Lamoreaux, SK AF Heidenreich, BJ Elliott, OT Charney, ND Virgien, KA Bridges, AW McKeon, MA Peck, SK Krause, D Gordon, JE Hunter, LR Lamoreaux, SK TI Limit on the electron electric dipole moment in gadolinium-iron garnet SO PHYSICAL REVIEW LETTERS LA English DT Article AB A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5x10(-24)e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization. C1 Amherst Coll, Dept Phys, Amherst, MA 01002 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Heidenreich, BJ (reprint author), Amherst Coll, Dept Phys, Amherst, MA 01002 USA. NR 20 TC 27 Z9 27 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 DEC 16 PY 2005 VL 95 IS 25 AR 253004 DI 10.1103/PhysRevLett.95.253004 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500023 PM 16384457 ER PT J AU Keavney, DJ Cheung, SH King, ST Weinert, M Li, L AF Keavney, DJ Cheung, SH King, ST Weinert, M Li, L TI Role of defect sites and Ga polarization in the magnetism of Mn-doped GaN SO PHYSICAL REVIEW LETTERS LA English DT Article ID SEMICONDUCTORS; FILMS; TEMPERATURE; ABSORPTION; (GA,MN)N; SURFACES AB We report a study of the Mn local structure, magnetism, and Ga moments in molecular beam epitaxy grown Mn-doped GaN films. Using x-ray absorption spectroscopy and magnetic circular dichroism, we find two distinct Mn sites and a Ga moment antiparallel to Mn. First-principles calculations reproduce this phenomenology and indicate that Mn preferentially populates Ga sites neighboring N split interstitial defects. These results show that defects may strongly affect the Mn ordering and magnetism, and that the GaN valence band is polarized, providing a long-range ferromagnetic ordering mechanism for Ga1-xMnxN. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Univ Wisconsin, Dept Phys, Milwaukee, WI 53211 USA. RP Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 26 TC 45 Z9 46 U1 0 U2 13 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 DEC 16 PY 2005 VL 95 IS 25 AR 257201 DI 10.1103/PhysRevLett.95.257201 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500068 PM 16384500 ER PT J AU Li, MZ Evans, JW AF Li, MZ Evans, JW TI Theoretical analysis of mound slope selection during unstable multilayer growth SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; CRYSTAL-GROWTH; HOMOEPITAXY AB A "step dynamics" model is developed for mound formation during multilayer homoepitaxy. Downward funneling of atoms deposited at step edges is incorporated and controls mound slope selection. Behavior of the selected slope differs from that predicted by phenomenological continuum treatments where the lateral mass current vanishes identically. Instead, this current is shown to vary periodically and vanish only on average. An exact coarse-grained continuum formulation with appropriate boundary conditions is derived and recovers step dynamics results. C1 Iowa State Univ, US DOE, Inst Phys Res & Technol, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. RP Iowa State Univ, US DOE, Inst Phys Res & Technol, Ames, IA 50011 USA. NR 20 TC 18 Z9 18 U1 0 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2005 VL 95 IS 25 AR 256101 DI 10.1103/PhysRevLett.95.256101 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500041 PM 16384474 ER PT J AU Li, X Kiran, B Cui, LF Wang, LS AF Li, X Kiran, B Cui, LF Wang, LS TI Magnetic properties in transition-metal-doped gold clusters: M@Au-6 (M=Ti,V,Cr) SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOELECTRON-SPECTROSCOPY; ELECTRONIC-STRUCTURE; NICKEL CLUSTERS; 4D IMPURITIES; ANIONS; ENERGY; 3D AB The electronic structure and magnetic properties in a series of transition-metal-doped Au clusters, MAu6- (M=Ti,V,Cr), are investigated experimentally using photoelectron spectroscopy (PES) and density functional calculations. PES features due to the impurity atoms and the Au-6 host are clearly observed. It is found that all the MAu6- and MAu6 clusters possess a planar structure, in which the transition metal atom is located in the center of an Au-6 ring and carries large magnetic moments (2, 3, and 4 mu(B) for MAu6, M=Ti, V, and Cr, respectively). C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. EM ls.wang@pnl.gov NR 33 TC 124 Z9 126 U1 3 U2 18 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2005 VL 95 IS 25 AR 253401 DI 10.1103/PhysRevLett.95.253401 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500026 PM 16386056 ER PT J AU Park, HS Gall, K Zimmerman, JA AF Park, HS Gall, K Zimmerman, JA TI Shape memory and pseudoelasticity in metal nanowires SO PHYSICAL REVIEW LETTERS LA English DT Article ID FCC METALS; STRESS; DEFECTS; CU AB Structural reorientations in metallic fcc nanowires are controlled by a combination of size, thermal energy, and the type of defects formed during inelastic deformation. By utilizing atomistic simulations, we show that certain fcc nanowires can exhibit both shape memory and pseudoelastic behavior. We also show that the formation of defect-free twins, a process related to the material stacking fault energy, nanometer size scale, and surface stresses is the mechanism that controls the ability of fcc nanowires of different materials to show a reversible transition between two crystal orientations during loading and thus shape memory and pseudoelasticity. C1 Vanderbilt Univ, Dept Civil & Environm Engn, Nashville, TN 37235 USA. Georgia Inst Technol, George W Woodruff Sch Mech Engn, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Park, HS (reprint author), Vanderbilt Univ, Dept Civil & Environm Engn, Nashville, TN 37235 USA. EM harold.park@vanderbilt.edu RI Zimmerman, Jonathan/A-8019-2012; Park, Harold/B-1525-2008 OI Park, Harold/0000-0001-5365-7776 NR 18 TC 201 Z9 204 U1 4 U2 32 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2005 VL 95 IS 25 AR 255504 DI 10.1103/PhysRevLett.95.255504 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500036 PM 16384469 ER PT J AU Ross, M Boehler, R Soderlind, P AF Ross, M Boehler, R Soderlind, P TI Xenon melting curve to 80 GPa and 5p-d hybridization SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-PRESSURE; MOLECULAR-DYNAMICS; PHASE-TRANSITIONS; METALLIZATION; ARGON; CLUSTERS; KRYPTON AB Measurements made in a laser heated diamond-anvil cell are reported that extend the melting curve of Xe to 80 GPa and 3350 K. The steep lowering of the melting slope (dT/dP) that occurs near 17 GPa and 2750 K results from the hybridization of the 5p-like valence and 5d-like conduction states with the formation of clusters in the liquid having icosahedral short-range order (ISRO). C1 Max Planck Inst Chem, D-55020 Mainz, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ross, M (reprint author), Max Planck Inst Chem, D-55020 Mainz, Germany. NR 36 TC 31 Z9 31 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 DEC 16 PY 2005 VL 95 IS 25 AR 257801 DI 10.1103/PhysRevLett.95.257801 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500076 PM 16384508 ER PT J AU Thayer, GE Sadowski, JT zu Heringdorf, FM Sakurai, T Tromp, RM AF Thayer, GE Sadowski, JT zu Heringdorf, FM Sakurai, T Tromp, RM TI Role of surface electronic structure in thin film molecular ordering SO PHYSICAL REVIEW LETTERS LA English DT Article ID PENTACENE; TRANSISTORS; MICROSCOPY; AU(111); GROWTH AB We show that the orientation of pentacene molecules is controlled by the electronic structure of the surface on which they are deposited. We suggest that the near-Fermi level density of states above the surface controls the interaction of the substrate with the pentacene pi orbitals. A reduction of this density as compared to noble metals, realized in semimetallic Bi(001) and Si(111)(5x2)Au surfaces, results in pentacene standing up. Interestingly, pentacene grown on Bi(001) is highly ordered, yielding the first vertically oriented epitaxial pentacene thin films observed to date. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan. Univ Duisburg Gesamthsch, Inst Laser & Plasma Phys, D-45117 Essen, Germany. IBM Corp, Div Res, TJ Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 26 TC 100 Z9 105 U1 0 U2 23 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 DEC 16 PY 2005 VL 95 IS 25 AR 256106 DI 10.1103/PhysRevLett.95.256106 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500046 PM 16384479 ER PT J AU Torija, MA Li, AP Guan, XC Plummer, EW Shen, J AF Torija, MA Li, AP Guan, XC Plummer, EW Shen, J TI "Live" surface ferromagnetism in Fe nanodots/Cu multilayers on Cu(111) SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTICLE SYSTEM; NANOPARTICLE SYSTEM; DYNAMICS; CU(100); FILMS AB We investigate the crossover behavior from two-dimensional (2D) to three-dimensional in multilayers of magnetic nanodots grown by stacking 2D Fe nanodot assemblies on Cu(111) single crystal substrate with a Cu spacing layer. Using an in situ magneto-optical Kerr effect, we have observed a striking ferromagnetic to spin-glass-like phase transition with an increasing number of Fe dot layers. The topmost layer of the Fe dots survives the phase transition and remains ferromagnetic. This unusual surface ferromagnetism is likely caused by a surface-state-mediated coupling which is stronger than the coupling in bulk layers. This is confirmed by the fact that the critical temperature of the surface ferromagnetism is considerably higher than that of the bulk spin-glass phase in the system. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Shen, J (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, POB 2008, Oak Ridge, TN 37831 USA. EM shenj@ornl.gov RI Li, An-Ping/B-3191-2012 OI Li, An-Ping/0000-0003-4400-7493 NR 19 TC 9 Z9 9 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2005 VL 95 IS 25 AR 257203 DI 10.1103/PhysRevLett.95.257203 PG 4 WC Physics, Multidisciplinary SC Physics GA 995QI UT WOS:000234118500070 PM 16384502 ER PT J AU Verlet, JRR Bragg, AE Kammrath, A Cheshnovsky, O Neumark, DM AF Verlet, JRR Bragg, AE Kammrath, A Cheshnovsky, O Neumark, DM TI Comment on "Characterization of excess electrons in water-cluster anions by quantum simulations" SO SCIENCE LA English DT Editorial Material ID DYNAMICS AB The conclusion by Turi et al. (Reports, 5 August 2005, p. 914) that all experimental spectral and energetic data on water-cluster anions point toward surface-bound electrons is overstated. Comparison of experimental vertical detachment energies with their calculated values for (H(2)O)(n)(-) clusters with surface-bound and internalized electrons supports previous arguments that both types of clusters exist. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Tel Aviv Univ, Sackler Fac Exact Sci, Sch Chem, IL-69978 Tel Aviv, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM dneumark@berkeley.edu RI Neumark, Daniel/B-9551-2009; Verlet, Jan/G-5940-2012 OI Neumark, Daniel/0000-0002-3762-9473; Verlet, Jan/0000-0002-9480-432X NR 7 TC 37 Z9 38 U1 0 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 16 PY 2005 VL 310 IS 5755 BP 1769 EP 1769 DI 10.1126/science.1119113 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 995II UT WOS:000234093600023 PM 16357246 ER PT J AU Vanroose, W Martin, F Rescigno, TN McCurdy, CW AF Vanroose, W Martin, F Rescigno, TN McCurdy, CW TI Complete photo-induced breakup of the H-2 molecule as a probe of molecular electron correlation SO SCIENCE LA English DT Article ID PHOTO-DOUBLE-IONIZATION; DOUBLE PHOTOIONIZATION; FRAGMENTATION; DEUTERIUM; HYDROGEN AB Despite decades of progress in quantum mechanics, electron correlation effects are still only partially understood. Experiments in which both electrons are ejected from an oriented hydrogen molecule by absorption of a single photon have recently demonstrated a puzzling phenomenon: The ejection pattern of the electrons depends sensitively on the bond distance between the two nuclei as they vibrate in their ground state. Here, we report a complete numerical solution of the Schrodinger equation for the double photoionization of H-2. The results suggest that the distribution of photoelectrons emitted from aligned molecules reflects electron correlation effects that are purely molecular in origin. C1 Katholieke Univ Leuven, Dept Comp Sci, B-3001 Heverlee, Belgium. Univ Autonoma Madrid, Dept Quim C9, Madrid 28049, Spain. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RP Vanroose, W (reprint author), Katholieke Univ Leuven, Dept Comp Sci, Celestijnenlaan 200A, B-3001 Heverlee, Belgium. RI Martin, Fernando/C-3972-2014; Vanroose, Wim/J-4292-2013 OI Martin, Fernando/0000-0002-7529-925X; Vanroose, Wim/0000-0001-8349-1391 NR 19 TC 89 Z9 89 U1 0 U2 12 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 DEC 16 PY 2005 VL 310 IS 5755 BP 1787 EP 1789 DI 10.1126/science.1120263 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 995II UT WOS:000234093600038 PM 16357254 ER PT J AU Cieliebak, M Eidenbenz, S Penna, P AF Cieliebak, M Eidenbenz, S Penna, P TI Partial Digest is hard to solve for erroneous input data SO THEORETICAL COMPUTER SCIENCE LA English DT Article DE partial digest; turnpike problem; point reconstruction; physical DNA mapping ID CONSTRUCTION; DNA AB The Partial Digest problem asks for the coordinates of in points on a line such that the pairwise distances of the points form a given multiset of ((m)(2)) distances. Partial Digest is a well-studied problem with important applications in physical mapping of DNA molecules. Its computational complexity status is open. Input data for Partial Digest from real-life experiments are always prone to error, which suggests to study variations of Partial Digest that take this fact into account. In this paper, we study the computational complexity of Partial Digest variants that model three different error types that can occur in the data: additional distances, missing distances, and erroneous fragment lengths. We show that these variations are NP-hard, hard to approximate, and strongly NP-hard, respectively. (c) 2005 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Discrete Simulat Sci CCS5, Los Alamos, NM 87545 USA. ETH, Inst Theoret Comp Sci, CH-8092 Zurich, Switzerland. Univ Salerno, Dipartimento Informat & Applicaz Renato M Capocel, Salerno, Italy. RP Eidenbenz, S (reprint author), Los Alamos Natl Lab, Discrete Simulat Sci CCS5, Los Alamos, NM 87545 USA. EM cieliebak@inf.ethz.ch; eidenben@lanl.gov; penna@dia.unisa.it NR 34 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3975 J9 THEOR COMPUT SCI JI Theor. Comput. Sci. PD DEC 16 PY 2005 VL 349 IS 3 BP 361 EP 381 DI 10.1016/j.tcs.2005.08.030 PG 21 WC Computer Science, Theory & Methods SC Computer Science GA 991AC UT WOS:000233783500006 ER PT J AU Jeoh, T Baker, JO Ali, MK Himmel, ME Adney, WS AF Jeoh, T Baker, JO Ali, MK Himmel, ME Adney, WS TI beta-D-Glucosidase reaction kinetics from isothermal titration microcalorimetry SO ANALYTICAL BIOCHEMISTRY LA English DT Article DE beta-glucosidase; cellobiase; isothermal titration microcalorimetry; enzyme kinetics; substrate inhibition ID TRICHODERMA-REESEI; SIMULTANEOUS SACCHARIFICATION; CELLOBIOSE HYDROLYSIS; ASPERGILLUS-NIGER; CORN STOVER; CALORIMETRY; FERMENTATION; INHIBITION; EXPRESSION; CELLULOSE AB The cellobiase activities of nine thermal stable mutants of Thermobifida fusca BglC were assayed by isothermal titration microcalorimetry (ITC). The mutations were previously generated using random mutagenesis and identified by high-temperature screening as imparting improved thermal stability to the beta-D-glucosidase enzyme. Analysis of the substrate-saturation curves obtained by ITC for the wild-type enzyme and the nine thermally stabilized mutants revealed that the wild type and all the mutants were subject to binding of a second substrate molecule. Furthermore, the "inhibited" enzyme-substrate complexes were shown to retain catalytic activity. In the case of three of the BglC mutants (N178I, N317Y/L444F, and N317Y/L444F/A433V), binding of a second substrate molecule resulted in improved cellobiose turnover rates at lower substrate concentrations. No correlation between denaturation temperatures of the mutants and activity on cellobiose at 25 degrees C was evident. However, one particular mutant, BglC S319C, was significantly improved in both thermal tolerance and cellobiase activity with respect to those of the wild-type BglC. The triple mutant, N317Y/L444F/A433V, had a 5 degrees C increase in denaturation temperature while maintaining activity levels similar to that of the wild type at higher substrate concentrations. ITC provided a highly sensitive and nondestructive means to continuously monitor the reaction of BglC with cellobiose, resulting in abundant data sets that could be rigorously analyzed by fitting to known enzyme kinetics models. One distinct advantage of using data from the ITC was the empirical validation of the pseudo steady state assumption, a necessary condition for obtaining solutions to the proposed mechanisms. (c) 2005 Elsevier Inc. All rights reserved. C1 Natl Bioenergy Ctr, Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Jeoh, T (reprint author), Natl Bioenergy Ctr, Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM tina_jeoh@nrel.gov NR 27 TC 27 Z9 27 U1 3 U2 16 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD DEC 15 PY 2005 VL 347 IS 2 BP 244 EP 253 DI 10.1016/j.ab.2005.09.031 PG 10 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 992ZK UT WOS:000233922300011 PM 16269126 ER PT J AU Van Berkel, GJ Kertesz, V AF Van Berkel, GJ Kertesz, V TI Expanded electrochemical capabilities of the electrospray ion source using porous flow-through electrodes as the upstream ground and emitter high-voltage contact SO ANALYTICAL CHEMISTRY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; GAS-PHASE; ANALYTE ELECTROLYSIS; CYSTEINE RESIDUES; VOLTAMMETRY; OXIDATION; INHERENT; TAGS AB Use of a porous flow-through electrode at the upstream ground contact or at both the upstream ground contact and the high-voltage emitter contact in an electrospray ion source was shown to provide for new types of electrochemical experiments utilizing only the electrochemistry inherent to electrospray. The normal stainless steel bore-through union serving as the upstream grounding point in a floated electrospray emitter system was replaced with a high surface area porous flow-through electrode assembly to achieve effective electrochemical reduction of analytes at this point in positive ion mode, and effective electrochemical oxidation of analytes in negative ion mode. This was demonstrated by the oxidation of 3,4dihydroxybenzoic acid and reserpine in negative ion mode and by the reduction of thionine in positive ion mode. In the case of reversible oxidation (3,4-dihydroxybenzoic acid) and reduction (thionine) processes, partial rereduction and reoxidation of the products due to reaction with products generated by cathodic and anodic processes at the emitter were observed, respectively. By implementing two high surface area porous flow-through electrodes in the system, one as the upstream grounding point and the other as the emitter electrode, a multiple-step reaction scheme was achieved that included consecutive electrochemical reduction and oxidation reactions and a followmg chemical reaction as demonstrated by the hydroquinone tagging of an initially disulfide-linked peptide. C1 Oak Ridge Natl Lab, Organ & Biol Mass Spectrometry Grp, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Organ & Biol Mass Spectrometry Grp, Div Chem Sci, Oak Ridge, TN 37831 USA. EM vanberkelgj@ornl.gov; kerteszv@ornl.gov RI Kertesz, Vilmos/M-8357-2016 OI Kertesz, Vilmos/0000-0003-0186-5797 NR 29 TC 27 Z9 27 U1 1 U2 22 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 DEC 15 PY 2005 VL 77 IS 24 BP 8041 EP 8049 DI 10.1021/ac051555l PG 9 WC Chemistry, Analytical SC Chemistry GA 995DD UT WOS:000234079200026 PM 16351154 ER PT J AU McDonnell, EE Han, SL Hilty, C Pierce, KL Pines, A AF McDonnell, EE Han, SL Hilty, C Pierce, KL Pines, A TI NMR analysis on microfluidic devices by remote detection SO ANALYTICAL CHEMISTRY LA English DT Article ID MAGNETIC-RESONANCE-SPECTROSCOPY; FLOW CAPILLARY-ELECTROPHORESIS; MEASURING REACTION-KINETICS; TOTAL ANALYSIS SYSTEMS; ON-A-CHIP; MICROCOIL NMR; SAMPLES; SEPARATION; H-1-NMR; PROBES AB We present a novel approach to perform high-sensitivity NMR imaging and spectroscopic analysis on microfluidic devices. The application of NMR, the most information-rich spectroscopic technique, to microfluidic devices remains a challenge because the inherently low sensitivity of NMR is aggravated by small fluid volumes leading to low NMR signal and geometric constraints resulting in poor efficiency for inductive detection. We address the latter by physically separating signal detection from encoding of information with remote detection. Thereby, we use a commercial imaging probe with sufficiently large diameter to encompass the entire device, enabling encoding of NMR information at any location on the chip. Because large-diameter coils are too insensitive for detection, we store the encoded information as longitudinal magnetization and flow it into the outlet capillary. There, we detect the signal with optimal sensitivity, using a solenoidal microcoil, and reconstruct the information encoded in the fluid. We present a generally applicable design for a detection-only microcoil probe that can be inserted into the bore of a commercial imaging probe. Using hyperpolarized Xe-129 gas, we show that this probe enables sensitive reconstruction of NMR spectroscopic information encoded by the large imaging probe while keeping the flexibility of a large coil. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP McDonnell, EE (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM eemoore@berkeley.edu RI Han, Songi/E-4723-2012; Hilty, Christian/C-1892-2015 OI Han, Songi/0000-0001-6489-6246; Hilty, Christian/0000-0003-2539-2568 NR 36 TC 34 Z9 34 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 15 PY 2005 VL 77 IS 24 BP 8109 EP 8114 DI 10.1021/ac051320+ PG 6 WC Chemistry, Analytical SC Chemistry GA 995DD UT WOS:000234079200034 PM 16351162 ER PT J AU Nelson, AJ Adams, JJ Schaffers, KI AF Nelson, AJ Adams, JJ Schaffers, KI TI Electronic structure of gadolinium calcium oxoborate SO APPLIED SURFACE SCIENCE LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; NONLINEAR-OPTICAL PROPERTIES; RARE-EARTH-METALS; PHOTOEMISSION SPECTRA; SURFACE; GD; CA4GDO(BO3)(3); CRYSTALS; OXYGEN AB Gadolinium calcium oxoborate (GdCOB) is a nonlinear optical material that belongs to the calcium-rare-earth (R) oxoborate family, with general composition Ca4RO(BO3)(3) (R3+ = La, Sm, Gd, Lu, Y). X-ray photoemission was applied to study the valence band electronic structure and surface chemistry of this material. High resolution photoemission measurements on the valence band electronic structure and Gd 3d and 4d, Ca 2p, B 1s and O 1s core lines were used to evaluate the surface and near surface chemistry. These results provide measurements of the valence band electronic structure and surface chemistry of this rare-earth oxoborate. (c) 2005 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nelson, AJ (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. EM nelson63@llnl.gov NR 21 TC 4 Z9 4 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD DEC 15 PY 2005 VL 252 IS 5 BP 1228 EP 1232 DI 10.1016/j.apsusc.2005.02.086 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 993WH UT WOS:000233985900007 ER PT J AU Floryk, D Huberman, E AF Floryk, D Huberman, E TI Differentiation of androgen-independent prostate cancer PC-3 cells is associated with increased nuclear factor-kappa B activity SO CANCER RESEARCH LA English DT Article ID PLASMINOGEN-ACTIVATOR INHIBITOR-2; GENE-EXPRESSION; SODIUM-BUTYRATE; COLON-CANCER; IN-VIVO; APOPTOSIS; TRIBUTYRIN; LEUKEMIA; THERAPY; GROWTH AB Recently, we have reported that inosine 5'-monophosphate dehydrogenase inhibitors, such as mycophenolic acid (MPA), induce the differentiation of PC-3 cells, which are derived from a human androgen-independent prostate cancer, into cells with a phenotype resembling maturing prostate secretory cells. Here, we describe such differentiation induced by the histone deacetylase inhibitor tributyrin. The maturation was defined by cytoplasmic vacuole production and induction of CD10, CD46, CD55, GRP78, keratin 17, and zinc-alpha-2-glycoprotein. To identify additional genes associated with tributyrin-induced PC-3 cell differentiation and to gain some insight into the mechanism that underlies this differentiation, we have, by means of microarray analyses, compared tributyrininduced gene expression patterns with those of MPA, which initiates PC-3 cell differentiation by a dissimilar mode of action. We suggested that genes induced by both tributyrin and MPA would be most likely associated with differentiation rather than with the unique action of each particular inducer. Our results indicated that tributyrin or MPA induced the expression of a large number of common genes, including genes known or assumed to be NF-kappa B dependent. The NF-kappa B dependency of a group of these genes, which included the PC-3 cell differentiation marker keratin 17, was confirmed by using two common NF-kappa B activation inhibitors, Bay11-082 and TMB-8, and p65 subunit of NF-kappa B complex specific small interfering RNA. Taken together, our results implicate both NF-kappa B-dependent and NF-kappa B-independent genes in the processes leading to PC-3 cell differentiation induced by tributyrin and MPA. C1 Argonne Natl Lab, Gene Express Grp, Argonne, IL 60439 USA. RP Huberman, E (reprint author), Argonne Natl Lab, Gene Express Grp, 9700 S Cass Ave,Bldg 202, Argonne, IL 60439 USA. EM elih@anl.gov FU NCI NIH HHS [CA 80826] NR 35 TC 24 Z9 24 U1 0 U2 3 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD DEC 15 PY 2005 VL 65 IS 24 BP 11588 EP 11596 DI 10.1158/0008-5472.CAN-05-1831 PG 9 WC Oncology SC Oncology GA 996FF UT WOS:000234159100046 PM 16357169 ER PT J AU Chin, YH Hu, JL Cao, CS Gao, YF Wang, Y AF Chin, YH Hu, JL Cao, CS Gao, YF Wang, Y TI Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor SO CATALYSIS TODAY LA English DT Article DE Fischer-Tropsch synthesis; carbon nanotube; engineered catalyst; microchannel reactor AB A novel microstructured catalyst based on aligned multiwall carbon nanotube arrays was synthesized and tested for Fischer-Tropsch synthesis (FTS) reaction in a microchannel reactor. Fabrication of such a structured catalyst first involved metal organic chemical vapor deposition (MOCVD) of a dense Al2O3 thin film over FeCrAlY foam to enhance the adhesion between ceramic-based catalyst and metal substrate. Aligned multiwall carbon nanotubes were deposited uniformly over the substrate by controlled catalytic decomposition of ethylene. These nanotube bundles were directly attached to FeCrAlY foam through a submicron layer of oxide thin film. Coating the outer surfaces of these nanobundles with an active catalyst layer forms a unique hierarchical structure with fine interstitials between the carbon nanotube bundles. The microstuctural catalyst possessed superior thermal conductivity inherent from carbon nanotube, which allows efficient heat removal from catalytic active sites during exothermic FTS reaction. The concept was tested and demonstrated in a microchannel fixed bed FTS reactor. FTS turn-over activity was found to enhance by a factor of four owing to potential improvement in mass transfer in the unique microstructure. Furthermore, improved temperature control with the carbon nanotube arrays also allows the Fischer-Tropsch synthesis being operated at temperatures as high as 265 degrees C without reaction runaway. (c) 2005 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Inst Interfac Catalysis, Richland, WA 99354 USA. RP Wang, Y (reprint author), Pacific NW Natl Lab, Inst Interfac Catalysis, 902 Battelle Blvd, Richland, WA 99354 USA. EM yongwang@pnl.gov RI Wang, Yong/C-2344-2013 NR 17 TC 40 Z9 41 U1 2 U2 33 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD DEC 15 PY 2005 VL 110 IS 1-2 BP 47 EP 52 DI 10.1016/j.cattod.2005.09.007 PG 6 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 992NN UT WOS:000233890900006 ER PT J AU Cao, CS Wang, Y Rozmiarek, RT AF Cao, CS Wang, Y Rozmiarek, RT TI Heterogeneous reactor model for steam reforming of methane in a microchannel reactor with microstructured catalysts SO CATALYSIS TODAY LA English DT Article DE microstructured catalysts; steam reforming; heterogeneous model; microchannel reactors ID KINETICS; SIMULATION AB Microstructured catalysts used for methane steam reforming in microchannel reactors are mathematically described and experimentally demonstrated under realistic process conditions. A heterogeneous model has been developed with a graphical interface to represent the three dimensions of the microchannel reactor. Porous metal substrates (FeCrAlY) were used to form engineered catalysts with active precious metal (Rh) for methane steam reforming. Two types of structures were evaluated in the microchannel reactors and simulated with the developed heterogeneous reactor model. Local temperature and methane concentration profiles within the structures are illustrated to show the correlation of the catalyst structure and its performance. Such a modeling technique provides a convenient and flexible method to evaluate variables in designing more efficient catalysts for the highly endothermic steam reforming reactions, as the desired mass and heat transfer characteristics are achieved. (c) 2005 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Inst Interfacial Catalysis, Richland, WA 99352 USA. RP Cao, CS (reprint author), Pacific NW Natl Lab, Inst Interfacial Catalysis, 902 Battelle Blvd, Richland, WA 99352 USA. EM chunshecao@yahoo.com; yongwang@pnl.gov RI Wang, Yong/C-2344-2013 NR 29 TC 27 Z9 28 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD DEC 15 PY 2005 VL 110 IS 1-2 BP 92 EP 97 DI 10.1016/j.cattod.2005.09.004 PG 6 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 992NN UT WOS:000233890900012 ER PT J AU Kenny, PA Bissell, MJ AF Kenny, PA Bissell, MJ TI Targeting TACE-dependent growth factor shedding in breast cancer. SO CLINICAL CANCER RESEARCH LA English DT Meeting Abstract CT AACR/NCI/EORTC International Conference on Molecular Targets and Cancer Therapeutics CY NOV 14-18, 2005 CL Philadelphia, PA SP AACR, NCI, EORTC, AMGEN, AstraZeneca, Britol-Myers Squibb Co, Pfizer, Sanofi Aventis, Bayer Hlth Car Pharmaceut, Lilly, Genentech, GSK GlaxoSmithKline, Johnson &Johnson, MERCK, NOVARTIS ONCOL, Centocor, OSI Oncol, Schering-Plough, BTG, Servier, RADPHARM, Cvitkovic & Associes C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Kenny, Paraic/A-3120-2008 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 1078-0432 J9 CLIN CANCER RES JI Clin. Cancer Res. PD DEC 15 PY 2005 VL 11 IS 24 SU S BP 8995S EP 8995S PN 2 PG 1 WC Oncology SC Oncology GA 999IJ UT WOS:000234382700130 ER PT J AU Nikanjam, M Blakely, EA Bjornstad, KA Forte, TM AF Nikanjam, M Blakely, EA Bjornstad, KA Forte, TM TI Synthetic LDL as targeted drug delivery vehicle for glioblastoma multiforme. SO CLINICAL CANCER RESEARCH LA English DT Meeting Abstract CT AACR/NCI/EORTC International Conference on Molecular Targets and Cancer Therapeutics CY NOV 14-18, 2005 CL Philadelphia, PA SP AACR, NCI, EORTC, AMGEN, AstraZeneca, Britol-Myers Squibb Co, Pfizer, Sanofi Aventis, Bayer Hlth Car Pharmaceut, Lilly, Genentech, GSK GlaxoSmithKline, Johnson &Johnson, MERCK, NOVARTIS ONCOL, Centocor, OSI Oncol, Schering-Plough, BTG, Servier, RADPHARM, Cvitkovic & Associes C1 Childrens Hosp, Oakland Res Inst, Oakland, CA 94609 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 1078-0432 J9 CLIN CANCER RES JI Clin. Cancer Res. PD DEC 15 PY 2005 VL 11 IS 24 SU S BP 9003S EP 9004S PN 2 PG 2 WC Oncology SC Oncology GA 999IJ UT WOS:000234382700165 ER PT J AU Chekanov, S AF Chekanov, S TI RunMC - an object-oriented analysis framework for Monte Carlo simulation of high-energy particle collisions. SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE event generators; QCD; high-energy physics; data analysis; C/C++ ID EP COLLISIONS; GENERATOR; SCATTERING; VERSION AB RunMC is an object-oriented framework aimed to generate and to analyse high-energy collisions of elementary particles using Monte Carlo simulations. This package, being based on C++ adopted by CERN as the main programming language for the LHC experiments, provides a common interface to different Monte Carlo models using modern physics libraries. Physics calculations (projects) can easily be loaded and saved as external modules. This simplifies the development of complicated calculations for high-energy physics in large collaborations. This desktop program is open-source licensed and is available on the LINUX and Windows/Cygwin platforms. Program summary Title of program: RunMC version 3.3 Catalogue identifier: ADWH Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADWH Program obtainable from:CPC Program Library, Queen's University of Belfast, N. Ireland Computer: x86, SGI, Sun Microsystems Operating system: Linux, Windows/Cygwin Memory required: 32 Mbytes No. of bits in a word: 32 No. of processors used: 1 Parallelized?: No No of lines in distributed program, including test data, etc.: No of bytes in distributed program, including test data, etc.: 22 464 383 Distribution format: tar.gz Typical running time: 0.004-0.01 s per event Programming language used: C/C++, Fortran, Java, bash Program requirements: g77, g++, make, X11, Java JRE1.4 and higher Nature of the physical problem: Simulation of high-energy collisions of elementary particles Method of solution: Monte Carlo method External libraries: CLHEP, ROOT, CERNLIB with PDFLIB References: http://hepforge.cedar.ac.uk/runmc/, http://www.hep.anl.gov/chakanau/runmc/. (C) 2005 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Chekanov, S (reprint author), Argonne Natl Lab, Div High Energy Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. EM chekanov@mail.desy.de NR 22 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD DEC 15 PY 2005 VL 173 IS 3 BP 175 EP 185 DI 10.1016/j.cpc.2005.03.114 PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 995SS UT WOS:000234124800005 ER PT J AU Yuan, T Cizmas, PG O'Brien, T AF Yuan, T Cizmas, PG O'Brien, T TI A reduced-order model for a bubbling fluidized bed based on proper orthogonal decomposition SO COMPUTERS & CHEMICAL ENGINEERING LA English DT Article DE computational methods in fluid dynamics; multiphase flow; nonlinear dynamics ID COMPUTER-SIMULATION; UNSTEADY FLOWS; DYNAMICS; AIRFOILS; EULER AB This paper presents the development of a reduced-order model (ROM) for dynamics of non-reactive, isothermal fluidized beds, based on the proper orthogonal decomposition (POD) method. Several implementations of this ROM were developed for a two-dimensional bubbling fluidized bed using numerical results from a full computational fluid dynamics (CFD) simulation of the bed. The solutions of the ROM were used to investigate the influence of the size of the particles on the motion of the bed. The solutions of the ROM were compared with the full model solutions for different particle diameters. The differences between the ROM and the full order solutions (the CFD results) were less than 3% within the range of diameters used for POD generation. The computational time of the ROM varied between 25 and 33% of the computational time of the full CFD solution. The computational speed-up depended on the complexity of the transport phenomena, the ROM methodology and the reconstruction error. (c) 2005 Elsevier Ltd. All right reserved. C1 Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77843 USA. Dept Energy, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Cizmas, PG (reprint author), Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77843 USA. EM cizmas@tamu.edu NR 31 TC 17 Z9 17 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-1354 J9 COMPUT CHEM ENG JI Comput. Chem. Eng. PD DEC 15 PY 2005 VL 30 IS 2 BP 243 EP 259 DI 10.1016/j.compchemeng.2005.09.001 PG 17 WC Computer Science, Interdisciplinary Applications; Engineering, Chemical SC Computer Science; Engineering GA 995TB UT WOS:000234125800006 ER PT J AU Andrews, KM Gibbons, JW AF Andrews, KM Gibbons, JW TI How do highways influence snake movement? Behavioral responses to roads and vehicles SO COPEIA LA English DT Article ID MORTALITY; POPULATIONS AB Roads affect animal survivorship and behavior and thereby can act as a barrier to movement, which exacerbates habitat fragmentation and disrupts landscape permeability. Field experiments demonstrated that interspecific differences in ecology and behavior of snakes affected responses of species when they encountered and crossed roads. The probability of crossing a road varied significantly among southeastern U.S. snakes, with smaller species exhibiting higher levels of road avoidance. Species also differed significantly in crossing speeds, with venomous snakes crossing more slowly than nonvenomous ones. All species crossed at a perpendicular angle, minimizing crossing time. A model incorporating interspecific crossing speeds and angles revealed that some species cannot successfully cross highways with high traffic densities. Individuals of three species immobilized in response to a passing vehicle, a behavior that would further prolong crossing time and magnify susceptibility to road mortality. Identifying direct and indirect effects of roads on snakes is essential for mitigating road impacts and for designing effective transportation systems in the future. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Andrews, KM (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. EM andrews@srel.edu; gibbons@srel.edu NR 29 TC 97 Z9 103 U1 2 U2 34 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD DEC 15 PY 2005 IS 4 BP 772 EP 782 DI 10.1643/0045-8511(2005)005[0772:HDHISM]2.0.CO;2 PG 11 WC Zoology SC Zoology GA 995GF UT WOS:000234088100007 ER PT J AU Wilkinson, LR Gibbons, JW AF Wilkinson, LR Gibbons, JW TI Patterns of reproductive allocation: Clutch and egg size variation in three freshwater turtles SO COPEIA LA English DT Article ID HATCHLING SNAPPING TURTLES; CHRYSEMYS-PICTA BELLII; MATERNAL BODY-SIZE; NATURAL-SELECTION; PARENTAL INVESTMENT; LIFE-HISTORY; CHELYDRA-SERPENTINA; MUD TURTLE; INCUBATION-TEMPERATURE; PROPAGULE SIZE AB Understanding the mechanisms and patterns of how energy is allocated into the reproductive components of offspring size and number is central to life-history theory. We used X-ray photographs from a long-term mark recapture study of Kinosternon subrubrum, Sternotherus odoratus, and Pseudemys floridana to investigate hypotheses concerning variation in reproductive allocation due to constraint on egg size, within-female variability (within and among clutches), interannual environmental variation, multiple annual clutches, allocation of continuous resources into small integer numbers of offspring (fractional offspring-size problem), and age. Patterns of reproductive allocation varied markedly within and among species. Overall, egg size varied as a function of maternal body size and age, intra-annual clutch frequency, the fractional offspring-size problem, and environmental variation. Clutch size varied with maternal body size, clutch frequency, and environmental variation. We examine how effectively the data support optimal-egg-size and phenotypic-plasticity models of reproductive allocation, and identify limitations of fundamental biological findings necessary to address the issues. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Wilkinson, LR (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. EM lwilkinson@srel.edu NR 68 TC 25 Z9 27 U1 2 U2 15 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD DEC 15 PY 2005 IS 4 BP 868 EP 879 DI 10.1643/0045-8511(2005)005[0868:PORACA]2.0.CO;2 PG 12 WC Zoology SC Zoology GA 995GF UT WOS:000234088100015 ER PT J AU Steefel, CI DePaolo, DJ Lichtner, PC AF Steefel, CI DePaolo, DJ Lichtner, PC TI Reactive transport modeling: An essential tool and a new research approach for the Earth sciences SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Review DE reactive transport; water-rock interaction; contaminant transport; magma transport; coupled processes ID TRACE-ELEMENT FRACTIONATION; KINETICALLY ADSORBING SOLUTES; PROCESSES INVOLVING MINERALS; HETEROGENEOUS POROUS-MEDIA; STABLE-ISOTOPE TRANSPORT; K-D APPROACH; SUBSURFACE SEDIMENTS; HYDROTHERMAL SYSTEMS; YUCCA MOUNTAIN; MELT TRANSPORT AB Reactive transport modeling is an essential tool for the analysis of coupled physical, chemical, and biological processes in Earth systems, and has additional potential to better integrate the results from focused fundamental research on Earth materials Appropriately designed models can describe the interactions of competing processes at a range of spatial and time scales, and hence are critical for connecting the advancing capabilities for materials characterization at the atomic scale with the macroscopic behavior of complex Earth systems. Reactive transport modeling has had a significant impact on the treatment of contaminant retardation in the subsurface, the description of elemental and nutrient fluxes between major Earth reservoirs, and in the treatment of deep Earth processes such as metamorphism and magma transport. Active topics of research include the development of pore scale and hybrid, or multiple continua, models to capture the scale dependence of coupled reactive transport processes. Frontier research questions, that are only now being addressed, include the effects of chemical microenvironments, coupled thermal-mechanical-chemical processes, controls on mineral-fluid reaction rates in natural media, and scaling of reactive transport processes from the microscopic to pore to field scale. (C) 2005 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Steefel, CI (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM CISteefel@lbl.gov RI Steefel, Carl/B-7758-2010 NR 120 TC 221 Z9 227 U1 11 U2 94 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 DEC 15 PY 2005 VL 240 IS 3-4 BP 539 EP 558 DI 10.1016/j.epsl.2005.09.017 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 995VH UT WOS:000234132000001 ER PT J AU Matmon, A Shaked, Y Porat, N Enzel, Y Finkel, R Lifton, N Boaretto, E Agnon, A AF Matmon, A Shaked, Y Porat, N Enzel, Y Finkel, R Lifton, N Boaretto, E Agnon, A TI Landscape development in an hyperarid sandstone environment along the margins of the Dead Sea fault: Implications from dated rock falls SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE cliff retreat; cosmogenic isotopes; optically stimulated lumincscence; Timna; Dead Sea rift ID COSMOGENIC NUCLIDE PRODUCTION; SOUTHERN ARAVA VALLEY; PRODUCTION-RATES; EROSION RATES; GEOMAGNETIC-FIELD; SCALING FACTORS; BE-10; AL-26; EARTHQUAKES; INSITU AB In this study, we explored the spatial and temporal relations between boulders and their original in-situ locations on sandstone bedrock cliffs. This was accomplished by combining field observations with dating methods using cosmogenic isotopes (Be-10 and C-14) and optically stimulated luminescence (OSL). Our conclusions bear both on the landscape evolution and cliff retreat process in the hyperarid region of Timna and on the methodology of estimating exposure ages using cosmogenic isotopes. We recognize three discrete rock fall events, at 31 ka, 15 ka, and 4 ka. In this hyperarid region, the most plausible triggering mechanism for rock fall events is strong ground acceleration caused by earthquakes generated by the nearby Dead Sea fault (DSF). Our record, however, under represents the regional earthquake record implying that ongoing development of detachment cracks prior to the triggering event might be slower than the earthquake cycle. Cliff retreat rates calculated using the timing of rock fall events and estimated thickness of rock removed in each event range between 0.14 m ky(-1) and 2 m ky(-1). When only full cycles are considered, we derive a more realistic range of 0.4 m ky(-1) to 0.7 in ky(-1). These rates are an order of magnitude faster than the calculated rate of surface lowering in the area. We conclude that sandstone cliffs at Timna retreat through episodic rock fall events that preserve the sharp, imposing, landscape characteristic to this region and that ongoing weathering of the cliff faces is minor. A 10%-20% difference in the Be-10 concentrations in samples from matching boulder and cliff faces that have identical exposure histories and are located only a few meters apart indicates that cosmogenic nuclide production rates are sensitive to shielding and vary spatially over short distances. However, uncertainties associated with age calculations yielded boulder and matching cliff face ages that are similar within 1 sigma. The use of external constraints in the form of field relations and OSL dating helped to establish each pair's age. The agreement between calculated C-14 and Be-10 ages indicates that the accumulation of Be-10 at depth by the capture of slow deep-penetrating muons was properly accounted for in the study. (C) 2005 Published by Elsevier B.V. C1 Hebrew Univ Jerusalem, Inst Earth Sci, IL-91904 Jerusalem, Israel. US Geol Survey, Menlo Pk, CA 94025 USA. Geol Survey Israel, IL-95501 Jerusalem, Israel. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. Weizmann Inst Sci, Dept Environm Sci & Energy Res, IL-76100 Rehovot, Israel. RP Matmon, A (reprint author), Hebrew Univ Jerusalem, Inst Earth Sci, IL-91904 Jerusalem, Israel. EM arimatmon@cc.huji.ac.il RI Lifton, Nathaniel/M-2017-2015 OI Lifton, Nathaniel/0000-0002-6976-3298 NR 59 TC 29 Z9 30 U1 1 U2 6 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 DEC 15 PY 2005 VL 240 IS 3-4 BP 803 EP 817 DI 10.1016/j.epsl.2005.06.059 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 995VH UT WOS:000234132000020 ER PT J AU Cances, B Juillot, F Morin, G Laperche, V Alvarez, L Proux, O Hazemann, JL Brown, GE Calas, G AF Cances, B Juillot, F Morin, G Laperche, V Alvarez, L Proux, O Hazemann, JL Brown, GE Calas, G TI XAS evidence of As(V) association with iron oxyhydroxides in a contaminated soil at a former arsenical pesticide processing plant SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID RAY-ABSORPTION SPECTROSCOPY; LEAD ARSENATE; SEQUENTIAL EXTRACTION; MINE TAILINGS; SPECIATION; ADSORPTION; EXAFS; MECHANISM; FRANCE; RETENTION AB The molecular-level speciation of arsenic has been determined in a soil profile in the Massif Central near Auzon, France that was impacted by As-based pesticides by combining conventional techniques (XRD, selective chemical extractions) with X-ray absorption spectroscopy (XAS). The arsenic concentration is very high at the top (>7000 mg kg(-1)) and decreases rapidly downward to a few hundreds of milligrams per kilogram. A thin layer of schultenite (PbHAsO4), a lead arsenate commonly used as an insecticide until the middle of the 20th century, was found at 10 cm depth. Despite the occurrence of this As-bearing mineral, oxalate extraction indicated that more than 65% of the arsenic was released upon dissolution of amorphous iron oxides, suggesting a major association of arsenic with these phases within the soil profile. Since oxalate extraction cannot unambiguously distinguish among the various chemical forms of arsenic, these results were confirmed by a direct in situ determination of arsenic speciation using XAS analysis. XANES data indicate that arsenic occurs mainly as As(V) along the soil profile except for the topsoil sample where a minor amount (7%) of As(III) was detected. EXAFS spectra of soil samples were fit by linear combinations of model compounds spectra and by a shell-by-shell method. These procedures clearly confirmed that As(V) is mainly(at least 80 wt%) associated with amorphous Fe(III) oxides as coprecipitates within the soil profile. If any, the proportion of schultenite, which was evidenced by XRD in a separate thin white layer, does not account for more than 10 wt % of arsenic in soil samples. This study emphasizes the importance of iron oxides in restricting arsenic dispersal within soils following dissolution of primary As-bearing solids manufactured for use as pesticides and released into the soils. C1 CNRS, UMR 7590, Inst Mineral & Phys Milieux Condenses, F-75015 Paris, France. Ctr Natl Rech Sites & Sols Pollues, F-59505 Douai, France. Bur Rech Geol & Minieres, EPI ENV, F-45050 Orleans, France. European Synchrotron Radiat Facil, F-38000 Grenoble, France. Univ Grenoble 1, UMR CNRS, Lab Geophys Interne & Tectonophys, F-38400 St Martin Dheres, France. CNRS, Lab Cristallog, F-38042 Grenoble 09, France. Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. SLAC, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Juillot, F (reprint author), CNRS, UMR 7590, Inst Mineral & Phys Milieux Condenses, 140 Rue Lourmel, F-75015 Paris, France. EM juillot@impmc.jussieu.fr RI Calas, Georges/B-2445-2012; Proux, Olivier/F-7344-2012; Beamline, FAME/G-9313-2012; JUILLOT, Farid/G-7943-2016 OI Calas, Georges/0000-0003-0525-5734; NR 41 TC 83 Z9 86 U1 5 U2 52 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC 15 PY 2005 VL 39 IS 24 BP 9398 EP 9405 DI 10.1021/es050920n PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 995VU UT WOS:000234133300007 PM 16475314 ER PT J AU Lal, D Gallup, CD Somayajulu, BLK Vacher, L Caffee, MW Jull, AJT Finkel, RC Speed, RC Winters, A AF Lal, D Gallup, CD Somayajulu, BLK Vacher, L Caffee, MW Jull, AJT Finkel, RC Speed, RC Winters, A TI Records of cosmogenic radionuclides Be-10, Al-26 and Cl-36 in corals: First studies on coral erosion rates and potential of dating very old corals SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PAPUA-NEW-GUINEA; SEA-LEVEL; INTERGLACIAL PERIOD; BERYLLIUM ISOTOPES; OCEAN CIRCULATION; REEF GROWTH; MARINE; CLIMATE; CARBONATES; BARBADOS AB We present results of measurements of cosmogenic Be-10, Al-26 and Cl-36, and the indigenous (intrinsic) concentrations of the stable elements Be, Al and Cl in 120-200 kyr old corals from Barbados and Puerto Rico. The concentration levels of these radionuclides in the corals lie in the range 10(4) to 10(8) atoms/g. A comparison of the measured nuclide concentrations with those expected to be produced in the corals by nuclear interactions of energetic cosmic radiation shows that (i) the radionuclides Al-26 and Cl-36 are derived from in situ cosmic ray interactions in the corals after their formation, but that (ii) the radionuclide Be-10 owes its provenance in the coralline lattice primarily due to incorporation of dissolved beryllium in seawater in the lattice structure of the corals. Copyright (c) 2005 Elsevier Ltd. C1 Scripps Inst Oceanog, Geosci Res Div, La Jolla, CA 92093 USA. Univ Minnesota, Dept Geol Sci, Duluth, MN 55812 USA. Univ Minnesota, Large Lakes Observ, Duluth, MN 55812 USA. Phys Res Lab, Ahmedabad 380009, Gujarat, India. Purdue Univ, PRIME Lab, W Lafayette, IN 47907 USA. Univ Arizona, Dept Geosci, NSF, Arizona Accelerator Mass Spectrometer Lab, Tucson, AZ 85721 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. Univ Puerto Rico, Dept Marine Sci, Mayaguez, PR 00680 USA. RP Lal, D (reprint author), Scripps Inst Oceanog, Geosci Res Div, La Jolla, CA 92093 USA. EM dlal@ucsd.edu RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 57 TC 6 Z9 6 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 15 PY 2005 VL 69 IS 24 BP 5717 EP 5728 DI 10.1016/j.gca.2005.08.012 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 999TQ UT WOS:000234413800007 ER PT J AU Yada, T Nakamura, T Noguchi, T Matsumoto, N Kusakabe, M Hiyagon, H Ushikubo, T Sugiura, N Kojima, H Takaoka, N AF Yada, T Nakamura, T Noguchi, T Matsumoto, N Kusakabe, M Hiyagon, H Ushikubo, T Sugiura, N Kojima, H Takaoka, N TI Oxygen isotopic and chemical compositions of cosmic spherules collected from the Antarctic ice sheet: Implications for their precursor materials SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID INTERPLANETARY DUST PARTICLES; DEEP-SEA SEDIMENTS; CARBONACEOUS CHONDRITES; SOLAR-SYSTEM; INDIVIDUAL MINERALS; ALLENDE METEORITE; STONY SPHERULES; ACCRETION RATE; TAGISH LAKE; MICROMETEORITES AB Bulk chemical compositions and oxygen isotopic compositions were analyzed for 48 stony cosmic spherules (melted micrometeorites) collected from the Antarctic ice sheet using electron- and ion-microprobes. No clear correlation was found between their isotopic compositions and textures. The oxygen isotopic compositions showed an extremely wide range from -28 parts per thousand to +93 parts per thousand in delta(18)O and from -2,1 parts per thousand to +13 parts per thousand in Delta(17)O. In delta(18)O-delta(17)O space, most samples (38 out of 48) plot close to the terrestrial fractionation line, but 7 samples plot along the carbonaceous chondrite anhydrous mineral (CCAM) line. Three samples plot well above the terrestrial fractionation line. One of these has a Delta(17)O of +13 parts per thousand, the largest value ever found in solar system materials. One possible precursor for this spherule could be O-16-poor planetary material that is still unknown as a meteorite. The majority of the remaining spherules are thought to be related to carbonaceous chondrites. Copyright (c) 2005 Elsevier Ltd. C1 Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Kyushu Univ, Grad Sch Sci, Dept Earth & Planetary Sci, Fukuoka 8128581, Japan. Ibaraki Univ, Dept Minerals & Biol Sci, Mito, Ibaraki 3108512, Japan. Okayama Univ, Inst Study Earths Interior, Misasa, Tottori 6820193, Japan. Grad Univ Adv Studies, Dept Polar Sci, Natl Inst Polar Res, Itabashi Ku, Tokyo 1738515, Japan. RP Yada, T (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM yada@anl.gov RI Sugiura, Naoji/A-1855-2009 NR 92 TC 33 Z9 34 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 15 PY 2005 VL 69 IS 24 BP 5789 EP 5804 DI 10.1016/j.gca.2005.08.002 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 999TQ UT WOS:000234413800012 ER PT J AU Hagerty, JJ Shearer, CK Papike, JJ AF Hagerty, JJ Shearer, CK Papike, JJ TI Petrogenesis of the Apollo 14 high-alumina basalts: Implications from ion microprobe analyses SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PICRITIC GLASS-BEADS; LUNAR MARE BASALTS; TRACE-ELEMENT; FRACTIONAL CRYSTALLIZATION; SILICATE MELT; KREEP BASALT; OLIVINE; MOON; EVOLUTION; VOLCANISM AB In this study, ion microprobe analyses of individual minerals are used to investigate the petrogenesis of the Apollo 14 high-Al basalts. We use trace element concentrations from individual minerals in the Apollo 14 high-Al basalts to evaluate both endogenic and exogenic models. The data show that if the Apollo 14 high-Al basalts were produced by melting within the lunar mantle, these basalts cannot be related to one another by closed-system fractional crystallization of a single basaltic melt. Rather, the trace element data show that variable amounts of a KREEP component were added to the basalts by either assimilation, mixing into mantle sources, or impact melting. Single-stage assimilation-fractional crystallization models can only explain the data from this study if an excessively large mass of urKREEP is assimilated into the parent magma before olivine crystallization. Alternatively, the trace element data can be explained if the Apollo 14 high-Al basalts were produced by melting multiple AI-rich mantle sources that contain different amounts of urKREEP. Finally, for impact melting to be a relevant process, the data require that multiple large impact melts be formed from mixed KREEP-rich target lithologies. The resulting impact melts must then crystallize to produce basalts with igneous textures, high Al(2)O(3) concentrations, uniform major element compositions, and a wide range of incompatible trace element concentrations. Copyright (c) 2005 Elsevier Ltd. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. 1 Univ New Mexico, Dept Earth & Planetary Sci, Inst Meteorit, Albuquerque, NM 87131 USA. RP Hagerty, JJ (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. EM jhagerty@lanl.gov NR 67 TC 7 Z9 7 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 15 PY 2005 VL 69 IS 24 BP 5831 EP 5845 DI 10.1016/j.gca.2005.08.008 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 999TQ UT WOS:000234413800015 ER PT J AU Bourne, NK Gray, GT AF Bourne, NK Gray, GT TI Dynamic response of binders; teflon, estane (TM) and Kel-F-800 (TM) SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EQUATION-OF-STATE; RAPID DEFORMATION-BEHAVIOR; STRAIN-RATE; GAS GUN; POLYMERS; COMPRESSION; INTERFEROMETER; COMPOSITES; ELASTOMER; TARGETS AB It is important to understand the mechanical behavior of polymeric materials that have a range of industrial and defence applications. In particular, several are used as the binder phase in plastic bonded explosives and propellants. Binder materials used in energetics need to be understood first to ensure their long-term, high-temperature stability when cycled during service, and second to ensure that the accidental loading of such materials leaves the explosives crystals within safe to handle. This work presents experimental data on equation-of-state and shock-induced damage evolution of the polymers teflon, estane (TM) and Kel-F-800 (TM). The tensile (spall) strength at high rate was quantified using real-time laser interferometric techniques on each polymer as a function of impact stress. Measurements were made of the lateral stress under impact using manganin gauges, which, when combined with longitudinal data, allowed investigation of the shear strength of each polymer. An increase of shear strength, determined in this manner, was noted for two polymers and comparisons are drawn with others investigated using the same technique. A discussion of the mechanical response of these polymers is presented. (c) 2005 American Institute of Physics. C1 Univ Manchester, Manchester M60 1QD, Lancs, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bourne, NK (reprint author), Univ Manchester, POB 88,Sackville St, Manchester M60 1QD, Lancs, England. EM neil.bourne@manchester.ac.uk RI Bourne, Neil/A-7544-2008 NR 54 TC 10 Z9 10 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 15 PY 2005 VL 98 IS 12 AR 123503 DI 10.1063/1.2143118 PG 9 WC Physics, Applied SC Physics GA 998SM UT WOS:000234339700011 ER PT J AU Hochbauer, T Misra, A Hattar, K Hoagland, RG AF Hochbauer, T Misra, A Hattar, K Hoagland, RG TI Influence of interfaces on the storage of ion-implanted He in multilayered metallic composites SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HELIUM BUBBLES; COPPER; STRENGTH; KINETICS AB We studied ion beam mixing and He accumulation in Cu/Nb multilayer thin films after 33 keV He implantation at room temperature to a dose of 1.5x10(17) atoms/cm(2). Multilayered thin films consisting of alternating Cu and Nb layers were produced by magnetron sputtering. Two types of samples, one with an individual layer thickness of 4 nm and another with 40 nm were examined. The Cu/Nb samples were analyzed in the as-deposited state, after He ion implantation, as well as after post-implantation annealing. The ion beam mixing of the interface structure was monitored by Rutherford backscattering spectrometry and cross-section transmission electron microscopy imaging. Elastic recoil detection analysis was performed to examine the helium concentration depth distribution. Scanning electron microscopy was employed to investigate He blister formation upon annealing. A comparison of the results deduced from the methods listed above reveals a very high morphological stability of the nanolayered structure. The nanolayered structure of the Cu/Nb multilayer thin films is retained. He bubbles were observed to reside within the layers but more so at the Cu/Nb incoherent interfaces. (c) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Misra, A (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM amisra@lanl.gov RI Hoagland, Richard/G-9821-2012; Misra, Amit/H-1087-2012 NR 24 TC 91 Z9 91 U1 5 U2 57 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 DEC 15 PY 2005 VL 98 IS 12 AR 123516 DI 10.1063/1.2149168 PG 7 WC Physics, Applied SC Physics GA 998SM UT WOS:000234339700024 ER PT J AU Chushak, Y Travesset, A AF Chushak, Y Travesset, A TI Coarse-grained molecular-dynamics simulations of the self-assembly of pentablock copolymers into micelles SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRIBLOCK COPOLYMERS; POLYMER-CHAINS; DIBLOCK; SHAPE AB Multiblock polymers in aqueous solution, where one or several blocks are hydrophobic, exhibit a rich variety of phases and states of aggregation. In this paper, we investigate a pentablock system ABCBA, where the B block is always hydrophilic and the A and C blocks have varying degrees of hydrophobicity depending on external conditions. We report coarse-grained molecular-dynamics simulations where the solvent is included explicitly and monomers interact via a 6-9 Lennard Jones potential function. The hydrophobic interaction is modeled by tuning the parameter controlling the strength of the interaction between the hydrophobic monomers and the solvent. We investigate the structure and morphology of the micelles for two concrete situations representing changes in temperature and the pH level. The simulated system is directly relevant to a recently synthesized pentablock system consisting of a triblock Pluronic (R) with an added pH-sensitive end group [B. C. Anderson , Macromolecules 36, 1670 (2003)]. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Ames Lab, Ames, IA 50011 USA. RP Chushak, Y (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM trvsst@ameslab.gov NR 25 TC 9 Z9 9 U1 0 U2 12 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 2005 VL 123 IS 23 AR 234905 DI 10.1063/1.2137714 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 996AD UT WOS:000234145900045 PM 16392947 ER PT J AU Verlet, JRR Kammrath, A Griffin, GB Neumark, DM AF Verlet, JRR Kammrath, A Griffin, GB Neumark, DM TI Electron solvation in water clusters following charge transfer from iodide SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLAR MOLECULAR CLUSTERS; HYDRATED ELECTRON; PHOTOELECTRON-SPECTROSCOPY; RELAXATION DYNAMICS; AQUEOUS SOLUTIONS; EXCESS ELECTRONS; SURFACE; ANIONS; TIME; LOCALIZATION AB The dynamics following charge transfer to solvent from iodide to a water cluster are studied using time-resolved photoelectron imaging of I-(H2O)(n) and I-(D2O)(n) clusters with n <= 28. The results show spontaneous conversion, on a time scale of similar to 1 ps, from water cluster anions with surface-bound electrons to structures in which the excess electron is more strongly bound and possibly more internalized within the solvent network. The resulting dynamics provide valuable insight into the electron solvation dynamics in water clusters and the relative stabilities between recently observed isomers of water cluster anions. (c) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM dneumark@berkeley.edu RI Neumark, Daniel/B-9551-2009; Verlet, Jan/G-5940-2012 OI Neumark, Daniel/0000-0002-3762-9473; Verlet, Jan/0000-0002-9480-432X NR 31 TC 23 Z9 23 U1 1 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 DEC 15 PY 2005 VL 123 IS 23 AR 231102 DI 10.1063/1.2137314 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 996AD UT WOS:000234145900002 PM 16392904 ER PT J AU Janssen, Y Angst, M Dennis, KW McCallum, RW Canfield, PC AF Janssen, Y Angst, M Dennis, KW McCallum, RW Canfield, PC TI Differential thermal analysis and solution growth of intermetallic compounds SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE single crystal growth; solidification; thermal analysis; growth from high-temperature solutions; rare-earth compounds ID SINGLE-CRYSTALS; SYSTEM; DIFFRACTION; ALLOYS; PR; ND AB To obtain single crystals by solution growth, an exposed primary solidification surface in the appropriate, but often unknown, equilibrium alloy phase diagram is required. Furthermore, an appropriate crucible material is needed, necessary to hold the molten alloy during growth, without being attacked by it. Recently, we have used the comparison of realistic simulations with experimental differential thermal analysis (DTA) curves to address both these problems. We have found: (1) complex DTA curves call be interpreted to determine ail appropriate heat treatment and starting composition for Solution growth, without having to determine the underlying phase diagrams in detail. (2) DTA can facilitate identification of appropriate crucible materials. DTA can thus be used to make the procedure to obtain single crystals of a desired phase by solution growth more efficient. We Will use some of the systems for which we have recently obtained single-crystalline samples using the combination of DTA and solution growth as examples. These systems are TbAl, Pr7Ni2Si5, and YMn4Al8. (c) 2005 Elsevier B.V. All rights reserved. C1 Iowa State Univ, Condensed Matter Phys, Ames, IA 50011 USA. Ames Lab, Mat & Engn Phys, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Janssen, Y (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. EM yjanssen@ameslab.gov RI Angst, Manuel/I-4380-2012; Canfield, Paul/H-2698-2014 OI Angst, Manuel/0000-0001-8892-7019; NR 28 TC 9 Z9 10 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC 15 PY 2005 VL 285 IS 4 BP 670 EP 680 DI 10.1016/j.jcrysgro.2005.08.044 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 996HI UT WOS:000234164600033 ER PT J AU Sethian, JD Raffray, AR Latkowski, J Blanchard, JP Snead, L Renk, TJ Sharafat, S AF Sethian, JD Raffray, AR Latkowski, J Blanchard, JP Snead, L Renk, TJ Sharafat, S TI An overview of the development of the first wall and other principal components of a laser fusion power plant SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID ENERGY; TARGETS; DESIGN; RADIATION; INJECTION; SOMBRERO AB This paper introduces the JNM Special Issue on the development of a first wall for the reaction chamber in a laser fusion power plant. In this approach to fusion energy a spherical target is injected into a large chamber and heated to fusion burn by an array of lasers. The target emissions are absorbed by the wall and encapsulating blanket, and the resulting heat converted into electricity. The bulk of the energy deposited in the first wall is in the form of X-rays (1.0-100 keV) and ions (0.1-4 MeV). in order to have a practical power plant, the first wall must be resistant to these emissions and suffer virtually no erosion oil each shot. A wall candidate based oil tungsten armor bonded to a low activation ferritic steel substrate has been chosen as the initial system to be studied. The choice was based oil the vast experience with these materials in a nuclear environment and the ability to address most of the key remaining issues with existing facilities. This overview paper is divided into three parts. The first part summarizes the current state of the development of laser fusion energy. The second part introduces the tungsten armored ferritic steel concept, the three critical development issues (thermo-mechanical fatigue, helium retention, and bonding) and the research to address them. Based oil progress to date the latter two appear to be resolvable, but the former remains a challenge. Complete details are presented in the companion papers in this JNM Special Issue. The third part discusses other factors that must be considered in the design of the first wall, including compatibility with blanket concepts, radiological concerns, and structural considerations. Published by Elsevier B.V. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Wisconsin, Madison, WI 53706 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RP Sethian, JD (reprint author), USN, Res Lab, Div Plasma Phys, 4555 Overlook Av SW, Washington, DC 20375 USA. EM sethian@this.nrl.navy.mil NR 43 TC 41 Z9 41 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC 15 PY 2005 VL 347 IS 3 BP 161 EP 177 DI 10.1016/j.jnucmat.2005.08.019 PG 17 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 994II UT WOS:000234024500002 ER PT J AU Tanaka, TJ Rochau, GA Peterson, RR Olson, CL AF Tanaka, TJ Rochau, GA Peterson, RR Olson, CL TI Testing IFE materials on Z SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID X-RAY; ITER DIVERTOR; WALL MATERIALS; Z-PINCH; ABLATION; PLASMAS; EROSION; ENERGY; ARMOR; POWER AB On a single-pulse basis, the tungsten armor for the chamber walls in a laser inertial fusion energy power plant must withstand X-ray fluences of 0.4-1.2 J/cm(2) with almost no mass loss, and preferably no surface changes. We have exposed preheated tungsten samples to 0.27 and 0.9 j/cm(2) X-ray fluence from the Z accelerator at Sandia National Laboratories to determine the single-shot X-ray damage threshold. Earlier focused ion beam analysis has shown that rolled powdered metal formed tungsten and tungsten alloys, will melt when exposed to 2.3 J/cm(2) on Z, but not at 1.3 J/cm(2). Three forms of tungsten - single-crystal (SING), chemical-vapor-deposited (CVD), and rolled powdered metal (PWM)-were exposed to fluence levels of 0.9 J/cm 2 without any apparent melting. However, the CVD and PWM sample surfaces were rougher after exposure than the SING sample, which was not roughened. BUCKY (1D) calculations show a threshold of 0.5 J/cm(2) for melting on Z. The present experiments indicate no melting but limited surface changes occur with polycrystalline samples (PWM and CVD) at 0.9 J/cm(2) and no surface changes other than debris for samples at 0.27 J/cm(2) (c) 2005 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tanaka, TJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM tjtanak@sandia.gov NR 28 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC 15 PY 2005 VL 347 IS 3 BP 244 EP 254 DI 10.1016/j.jnucmat.2005.08.016 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 994II UT WOS:000234024500007 ER PT J AU Latkowski, JF Abbott, RP Schmitt, RC Bell, BK AF Latkowski, JF Abbott, RP Schmitt, RC Bell, BK TI Effect of multi-shot X-ray exposures in IFE armor materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB As part of the High Average Power Laser (HAPL) program the performance of tungsten as an armor material is being studied. While the armor would be exposed to neutrons, X-rays and ions within an inertial fusion energy (IFE) power plant, the thermomechanical effects are believed to dominate. Using a pulsed X-ray source, long-term exposures of tungsten have been completed at fluences that are of interest for the IFE application. Modeling is used in conjunction with experiments on the XAPPER X-ray damage facility in an effort to recreate the effects that would be expected in an operating IFE power plant. X-ray exposures have been completed for a variety of X-ray fluences and number of shots. Analysis of the samples suggests that surface roughening has a threshold that is very close to the fluences that reproduce the peak temperatures expected in an IFE armor material. (c) 2005 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Latkowski, JF (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,Mailstop L-641, Livermore, CA 94551 USA. EM latkowski@llnl.gov NR 8 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC 15 PY 2005 VL 347 IS 3 BP 255 EP 265 DI 10.1016/j.jnucmat.2005.08.018 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 994II UT WOS:000234024500008 ER PT J AU Renk, TJ Provencio, PP Tanaka, TJ Olson, CL Peterson, RR Stolp, JE Schroen, DG Knowles, TR AF Renk, TJ Provencio, PP Tanaka, TJ Olson, CL Peterson, RR Stolp, JE Schroen, DG Knowles, TR TI Chamber wall materials response to pulsed ions at power-plant level fluences SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Candidate dry-wall materials for the reactor chambers of future laser-driven Inertial Fusion Energy (IFE) power plants have been exposed to ion pulses from RHEPP-1, located at Sandia National Laboratories. These pulses simulate the MeV-level ion pulses with fluences of up to 20 J/cm(2) that call be expected to impinge on the first wall of such future plants. Various forms of tungsten and tungsten alloy were subjected to up to 1600 pulses, usually while being heated to 600 degrees C. Other metals were exposed as well. Thresholds for roughening and material removal, and evolution of surface morphology were measured and compared with code predictions for materials response. Powder-metallurgy (PM) tungsten is observed to undergo surface roughening and subsurface crack formation that evolves over hundreds Of Pulses, and which call occur both below and above the melt threshold. This roughening is worse than for other metals, and worse than for either tungsten alloyed with rhenium (W25Re), or for CVD and single-crystal forms of tungsten. Carbon, particularly the form used in composite material, appears to suffer material loss well below its sublimation point. Some engineered materials were also investigated. It appears that some modification to PM tungsten is required for its successful use in a reactor environment. (c) 2005 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Schafer Corp, Livermore, CA USA. Energy Sci Labs Inc, San Diego, CA USA. RP Renk, TJ (reprint author), Sandia Natl Labs, MS 1193 POB 5800, Albuquerque, NM 87185 USA. EM tjrenk@sandia.gov NR 8 TC 22 Z9 22 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC 15 PY 2005 VL 347 IS 3 BP 266 EP 288 DI 10.1016/j.jnucmat.2005.08.021 PG 23 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 994II UT WOS:000234024500009 ER PT J AU Gilliam, SB Gidcumb, SM Parikh, NR Forsythe, DG Patnaik, BK Hunn, JD Snead, LL Lamaze, GP AF Gilliam, SB Gidcumb, SM Parikh, NR Forsythe, DG Patnaik, BK Hunn, JD Snead, LL Lamaze, GP TI Retention and surface blistering of helium irradiated tungsten as a first wall material SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID INERTIAL FUSION-REACTORS; CRITICAL ASSESSMENTS; TARGET IMPLOSION; WALL RESPONSE; CHAMBER; BEHAVIOR AB The first wall of an inertial fusion energy reactor may suffer from surface blistering and exfoliation due to helium ion irradiation and extreme temperatures. Tungsten is a candidate for the first wall material. A study of helium retention and surface blistering with regard to helium dose, temperature, pulsed implantation, and tungsten microstructure was conducted to better understand what may occur at the first wall of the reactor. Single crystal Lind polycrystalline tungsten samples were implanted with 1.3 MeV He-3 in doses ranging from 10(19) m(-2) to 10(22) m(-2). Implanted samples were analyzed by He-3(d,P)(4) He nuclear reaction analysis and He-3(n,p)T neutron depth profiling techniques. Surface blistering was observed for doses greater than 10(21) He/m(2). For He fluences of 5 x 10(20) He/m(2), similar retention levels in both microstructures resulted without blistering. Implantation and flash heating in cycles indicated that helium retention was mitigated with decreasing He dose per cycle. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Gilliam, SB (reprint author), Univ N Carolina, Dept Phys & Astron, Phillips Hall,CB 3255, Chapel Hill, NC 27599 USA. EM sgilliam@physics.unc.edu NR 12 TC 48 Z9 48 U1 0 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC 15 PY 2005 VL 347 IS 3 BP 289 EP 297 DI 10.1016/j.jnucmat.2005.08.017 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 994II UT WOS:000234024500010 ER PT J AU Hashimoto, N Hunn, JD Parikh, N Gilliam, S Gidcumb, S Patnaik, B Snead, LL AF Hashimoto, N Hunn, JD Parikh, N Gilliam, S Gidcumb, S Patnaik, B Snead, LL TI Microstructural analysis on helium retention of ion-irradiated and annealed tungsten foils SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID BEHAVIOR AB The helium retention characteristics and helium bubble distribution in tungsten were studied using He-3(d,p)(4) He nuclear reaction analysis (NRA) and transmission electron microscopy (TEM) on two forms of tungsten: single crystal and polycrystalline, implanted to 1 X 10(19) He-3/m(2) at 850 degrees C and annealed at 2000 degrees C. The NRA results revealed that as-implanted single crystal and polycrystalline tungsten exhibited similar helium retention characteristics. Stepwise annealing reduced the helium retention in both single crystal and polycrystalline tungsten when the number of implantation steps and annealing time were increased. The TEM results indicated that microstructure played a large role in helium trapping; the existence of grain boundaries led to significant cavity formation and greater cavity growth. Single crystal tungsten had less trapping sites for helium, allowing long range He diffusion during annealing. The decrease of He retention in polycrystalline tungsten during stepwise annealing was probably due to significant recrystallization, resulting in decrease of grain boundary density. (c) 2005 Elsevier B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ N Carolina, Chapel Hill, NC 27599 USA. RP Hashimoto, N (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,Bldg 4500S,MS 6136, Oak Ridge, TN 37831 USA. EM hashimoton@ornl.gov; nparikh@physics.unc.edu RI HASHIMOTO, Naoyuki/D-6366-2012 NR 13 TC 10 Z9 10 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC 15 PY 2005 VL 347 IS 3 BP 307 EP 313 DI 10.1016/j.jnucmat.2005.08.010 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 994II UT WOS:000234024500012 ER PT J AU Zhu, YH Sia, SLP Kooli, F Carpenter, K Kemp, RA AF Zhu, YH Sia, SLP Kooli, F Carpenter, K Kemp, RA TI Another example of carborane based trianionic ligand: Syntheses and catalytic activities of cyclohexylamino tailed ortho-carboranyl zirconium and titanium dicarbollides SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article; Proceedings Paper CT 1st Metallocene Catalysis Symposium CY NOV 10-12, 2004 CL Inst Chem & Engn Sci, Singapore, SINGAPORE HO Inst Chem & Engn Sci DE carborane trianion; half-sandwich metallocarborane; ligand immobilization; olefin polymerization ID STRUCTURAL-CHARACTERIZATION; OLEFIN POLYMERIZATION; GROUP-4 METALLACARBORANES; VINYL-CHLORIDE; COMPLEXES; CHEMISTRY; INSERTION; ETHYLENE; BEARING AB In situ reaction of Li[closo-1-Ph-1,2-C2B10H10] with 7-azabicyclo [4.1.0] heptane results in the formation of the disubstituted carborane, closo-1-Ph-2-(2'-aminocyclohexyl)-1,2-C2B10H10 (1), in 63% yield. Decapitation of (1) with potassium hydroxide in refluxing ethanol produces the cage-opened nido-carborane, K[nido-7-Ph-8-(2'-aminocyclohexyl)-7,8-C2B9H10](-) (2), in 80% yield. Deprotonation of the above monoanion with two equivalents of n-butyllithium followed by reaction with anhydrous MCl4 (.) 2THF (M = Zr, Ti) provides d(0)-half-sandwich metallocarboranes, closo-1-M(Cl)-2-Ph-3-(2'-sigma-(H)N-cyclohexyl)-2,3-eta(5)-C2B9H9 (3 M = Zr; 4 M = Ti) in 53% and 42% yields, respectively. The reaction of Li[closo-1,2-C2B10H11] with 7-azabicyclo [4.1.0] heptane in THF affords closo-1-(2'-aminocyclohexyl)-1,2-C2B10H10 (5) in 59% yield. Immobilization of the carboranyl amino ligand (1) to an organic support, Merrifield's peptide resin (1%), has been achieved by the reaction of the sodium salt of (5) with polystyryl chloride in THF to produce closo-1-(2'-aminocyclohexyl)-2-polystyryl-1,2-C2B10H10 (6) in 87% yield. Further reaction of the dianion derived from (6) with anhydrous ZrCl4 (.) 2THF led to the formation of the organic polystyryl supported d(0)-half-sandwich metallocarborane, closo-1-Zr(Cl)-2-(2'-sigma-(H)N-cyclohexyl)-3-polystyryl-2,3-eta(5)-C2B9H9 (7), in 38% yield. These new compounds have been characterized by elemental analyses, NMR, and IR spectra. Polymerizations of both ethylene and vinyl chloride with (3) and (7) have been performed in toluene using MMAO-7 (13% ISOPAR-E) as the co-catalyst. Molecular weights up to 32.8 x 10(3) (M-w/M-n = 1.8) and 9.5 x 10(3) (M-w/M-n = 2.1) were obtained for PE and PVC, respectively. (c) 2005 Elsevier B.V. All rights reserved. C1 Inst Chem & Engn Sci Ltd, Singapore 627833, Singapore. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Zhu, YH (reprint author), ICES, Apply Cat Ayer Rajah Crescent, Singapore 139959, Singapore. EM zhu_yinghuai@iccs.a-star.edu.sg NR 39 TC 5 Z9 5 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD DEC 15 PY 2005 VL 690 IS 26 BP 6284 EP 6291 DI 10.1016/j.jorganchem.2005.04.052 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 996GB UT WOS:000234161300005 ER PT J AU Wang, XB Woo, HK Kiran, B Wang, LS AF Wang, XB Woo, HK Kiran, B Wang, LS TI Photoelectron spectroscopy and electronic structures of fullerene oxides: C60Ox- (x=1-3) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID EPOXIDE; C-60; BUCKMINSTERFULLERENE; PHOTODETACHMENT; OXIDATION; OZONE; ELECTROSPRAY; DERIVATIVES; IONIZATION; CLUSTERS AB We report a photoelectron spectroscopy (PES) study on a series of fullerene oxides, C60Ox- (x = 1-3). The PES spectra reveal one isomer for C60O-, two isomers for C60O2-, and multiple isomers for C60O3-. Compared to C-60, the electronic structures Of C60Ox are only slightly perturbed, resulting in similar anion photoelectron spectra. The electron affinity Of C60Ox was observed to increase only marginally with the number of oxygen atoms, x, from 2.683 eV for C-60, to 2.745 eV for C60O, and 2.785 eV/2.820 eV for C60O2 (two isomers). We also carried out theoretical calculations, which confirmed the observed isomers and showed that all the fullerene oxides are in the form of epoxide. The PES and theoretical calculations, as well as molecular orbital analysis, indicate that addition of oxygen atoms to the C-60 cage only modifies the local carbon network and leave the rest of the fullerene cage largely intact geometrically and electronically. C1 Washington State Univ, Dept Phys, Richland, WA 99354 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99354 USA. EM ls.wang@pnl.gov NR 35 TC 7 Z9 7 U1 4 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 DEC 15 PY 2005 VL 109 IS 49 BP 11089 EP 11092 DI 10.1021/jp055775e PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 991YN UT WOS:000233850900001 PM 16331890 ER PT J AU Maharrey, S Behrens, R AF Maharrey, S Behrens, R TI Thermal decomposition of energetic materials. 5. Reaction processes of 1,3,5-trinitrohexahydro-s-triazine below its melting point SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID BEAM MASS-SPECTROMETRY; CONDENSED-PHASE DECOMPOSITION; 1,3,5 TRIAZINE RDX; OCTAHYDRO-1,3,5,7-TETRANITRO-1,3,5,7-TETRAZOCINE HMX; PYROLYSIS PRODUCTS; MOLECULAR-BEAM; TEMPERATURES; MECHANISM; RATES AB Through the use of simultaneous thermogravimetry modulated beam mass spectrometry, optical microscopy, hot-stage time-lapsed microscopy, and scanning electron microscopy measurements, the physical and chemical processes that control the thermal decomposition of 1,3,5-trinitrohexahydro-s-triazine (RDX) below its melting point (160-189 degrees C) have been identified. Two gas-phase reactions of RDX are predominant during the early stages of an experiment. One involves the loss of HONO and HNO and leads to the formation of H2O, NO, NO2, and oxy-s-triazine (OST) or s-triazine. The other involves the reaction of NO with RDX to form NO2 and 1-nitroso-3,5-dinitrohexahydro-s-triazine (ONDNTA), which subsequently decomposes to form a set of products of which CH2O and N2O are the most abundant. Products from the gas-phase RDX decomposition reactions, such as ONDNTA, deposit on the surface of the RDX particles and lead to the development of a new set of reaction pathways that occur on the surface of the RDX particles. The initial surface reactions occur on surfaces of those RDX particles in the sample that can accumulate the greatest amount of products from the gas-phase reactions. Initial surface reactions are characterized by the formation of islands of reactivity on the RDX surface and lead to the development of an orange-colored nonvolatile residue (NVR) film on the surface of the RDX particles. The NVR film is most likely formed via the decomposition of ONDNTA on the surface of the RDX particles. The NVR film is a nonstoichiometric and dynamic material, which reacts directly with RDX and ONDNTA, and is composed of remnants from RDX and ONDNTA molecules that have reacted with the NVR. Reactions involving the NVR become dominant during the later stage of the decomposition process. The NVR reacts with RDX to form ONDNTA via abstraction of an oxygen atom from an NO2 group. ONDNTA may undergo rapid loss of N-2 and NO2 with the remaining portion of the molecule being incorporated into the dynamic NVR. The dynamic NVR also decomposes and leads to the formation of H2O, CH2O, N2O, NH2CHO, (CH3)(2)NCHO, (CH3)(2)NNO, C2H2N2O, and (CH3)(3)N or CH3NCH2CH3. The competition between reaction of the dynamic NVR with RDX and its own thermal decomposition manifests itself in a rapid increase in the rate of evolution of the NVR decomposition products as the amount of RDX remaining in the sample nears depletion. The reactions between the NVR film and RDX on the surface of the RDX particles leads to a localized environment that creates a layer of molten RDX on the surface of the particles where reactions associated with the liquid-phase decomposition of RDX may occur. The combination of these reaction processes leads to an acceleration of the reaction rate in the later stage of the decomposition process and creates an apparent reaction rate behavior that has been referred to as autocatalytic in many previous studies of RDX decomposition. A reaction scheme summarizing the reaction pathways that contribute to the decomposition of RDX below its melting point is presented. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Behrens, R (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. EM rbehren@sandia.gov NR 29 TC 25 Z9 26 U1 1 U2 20 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 DEC 15 PY 2005 VL 109 IS 49 BP 11236 EP 11249 DI 10.1021/jp054188q PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 991YN UT WOS:000233850900018 PM 16331907 ER PT J AU Small, D Rosokha, SV Kochi, JK Head-Gordon, M AF Small, D Rosokha, SV Kochi, JK Head-Gordon, M TI Characterizing the dimerizations of phenalenyl radicals by ab initio calculations and spectroscopy: sigma-bond formation versus resonance pi-stabilization SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; DENSITY-FUNCTIONAL THEORY; DIFFUSE INTERSTELLAR BANDS; SMALL SOOT PARTICLES; ELECTRONIC-STRUCTURE; MOLECULAR CONDUCTOR; OPTICAL-TRANSITIONS; PHYSICAL-PROPERTIES; DIMERIC PAIR; CHEMISTRY AB Electronic-structure calculations for the self-association of phenalenyl radical (P-center dot) predict the formation of dimeric species (sigma-P-2) in which both moieties are connected by a sigma-bond with r(P-P) similar to 1.59 angstrom and bond dissociation enthalpy of Delta H-D similar to 16 kcal mol(-1). Such an unusually weak sigma-bond is related to the loss of aromatic stabilization energy of similar to 34 kcal mol(-1) per phenalenyl moiety, largely owing to rehybridization. Ab initio calculations also reveal that the corresponding (one-electron) bond between phenalenyl radical and its closed-shell cation in sigma-P-2(+center dot) is unstable relative to dissociation. Time-dependent DFT computations indicate the absence of any (strongly allowed) electronic transition in the visible region of the absorption spectrum of phenalenyl sigma-dimer. Such theoretical predictions are supported by experimental (ESR and UV-NIR) spectroscopic studies, in which the availability of a series of sterically hindered phenalenyl radicals allows definitive separations of the sigma-dimerization process from interference by pi-dimerization. As such, the thermodynamic parameters (determined from the temperature dependence of the ESR signals) with Delta H-D = 14 kcal mol(-1) and Delta S-D = 52 e.u. can be assigned to the formation of the colorless sigma-dimer. Similar results are obtained for all phenalenyl derivatives (provided their substitution patterns allow a-bond formation) to confirm the energetic preference of sigma-dimerization over pi-dimerization. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. RP Kochi, JK (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM jkochi@uh.edu; mhg@cchem.berkeley.edu NR 65 TC 53 Z9 53 U1 0 U2 12 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 DEC 15 PY 2005 VL 109 IS 49 BP 11261 EP 11267 DI 10.1021/jp054244n PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 991YN UT WOS:000233850900021 PM 16331910 ER PT J AU Neale, NR Kopidakis, N van de Lagemaat, J Gratzel, M Frank, AJ AF Neale, NR Kopidakis, N van de Lagemaat, J Gratzel, M Frank, AJ TI Effect of a coadsorbent on the performance of dye-sensitized TiO2 solar cells: Shielding versus band-edge movement SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NANOCRYSTALLINE PHOTOVOLTAIC CELLS; CHARGE-COLLECTION EFFICIENCY; ELECTRON-TRANSPORT; TRANSIENT ABSORPTION; RECOMBINATION; PHOTOCURRENT; ADSORPTION; COMPLEXES; KINETICS; FILMS AB The mechanism by which the adsorbent chenodeoxycholate, cografted with a sensitizer onto TiO2 nanocrystals, alters the open-circuit photovoltage and short-circuit current of dye-sensitized solar cells was investigated. The influence of tetrabutylammonium chenodeoxycholate on dye loading was studied under a variety of conditions in which the TiO2 films were exposed to the sensitizing dye and coadsorbent. Photocurrent-voltage measurements combined with desorption studies revealed that adding chenodeoxycholate reduces the dye loading by as much as 60% while having a relatively small effect on the short-circuit photocurrent. Calculations along with measurements showed that even at low loading, enough dye is present to absorb a significant fraction of the incident light in the visible spectrum. In concurrence with the observations of others, we find evidence for weakly and strongly adsorbed forms of the dye resulting from either different binding conformations or aggregates. The most strongly adsorbed dyes are less susceptible to displacement by chenodeoxycholate than those that are weakly adsorbed. While having no observable effect on dye coverage, multiple exposures of a TiO2 film to a dye solution substantially increased the fraction of strongly adsorbed dye as judged by the resistance of the adsorbed dye to displacement by chenodeoxycholate. Measurements of the open-circuit voltage as a function of the photocharge density, determined by infrared transmittance, showed that chenodeoxycholate, not only shifts the conduction band edge to negative potentials, but also significantly increases the rate of recombination. The net effect of adding chenodeoxycholate is, however, to improve the photovoltage. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Swiss Fed Inst Technol, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland. RP Frank, AJ (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM arthur_frank@nrel.gov RI Graetzel, Michael/G-4870-2011; van de Lagemaat, Jao/J-9431-2012; Kopidakis, Nikos/N-4777-2015 NR 42 TC 222 Z9 224 U1 4 U2 71 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 DEC 15 PY 2005 VL 109 IS 49 BP 23183 EP 23189 DI 10.1021/jp0538666 PG 7 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300015 PM 16375281 ER PT J AU Wang, LW AF Wang, LW TI Charging effects in a CdSe nanotetrapod SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SEMICONDUCTOR QUANTUM DOTS; PSEUDOPOTENTIAL CALCULATIONS; ELECTRON; NANOCRYSTALS; ENERGIES; COULOMB; INP AB The charging effects in a CdSe nanotetrapod have been theoretically investigated by using an atomistic pseudopotential method. We showed that the simple quasiparticle equation based on classical electrostatic consideration can be derived from the many-body GW equation under proper approximations. We found that the surface polarization potential can significantly change the electron wave functions, and there is an incomplete cancellation for this potential between the single particle energies and the electron-hole Coulomb interaction. Thus, it is necessary to include this potential in the calculation for complex unconvex systems. We also calculated the electron addition energies for a tetrapod. Unlike a simple spherical quantum dot, in which the addition energies are almost a constant, there is a large variation in the calculated addition energies for different numbers of electrons in a tetrapod. C1 Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. RP Wang, LW (reprint author), Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. EM lwwang@lbl.gov NR 23 TC 24 Z9 24 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 DEC 15 PY 2005 VL 109 IS 49 BP 23330 EP 23335 DI 10.1021/jp054349q PG 6 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300037 PM 16375303 ER PT J AU Zhao, J Schaefer, DW Shi, DL Lian, J Brown, J Beaucage, G Wang, LM Ewing, RC AF Zhao, J Schaefer, DW Shi, DL Lian, J Brown, J Beaucage, G Wang, LM Ewing, RC TI How does surface modification aid in the dispersion of carbon nanofibers? SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PARTICLE-SIZE DISTRIBUTIONS; SMALL-ANGLE SCATTERING; MAXIMUM-ENTROPY METHOD; X-RAY-SCATTERING; NANOTUBES; ACID AB Small-angle light scattering is used to assess the dispersion behavior of vapor-grown carbon nanofibers suspended in water. These data provide the first insights into the mechanism by which surface treatment promotes dispersion. Both acid-treated and untreated nanofibers exhibit hierarchical morphology consisting of small-scale aggregates (small bundles) that agglomerate to form fractal clusters that eventually precipitate. Although the morphology of the aggregates and agglomerates is nearly independent of surface treatment, their time evolution is quite different. The time evolution of the small-scale bundles is studied by extracting the size distribution from the angle-dependence of the scattered intensity, using the maximum entropy method in conjunction with a simplified tube form factor. The bundles consist of multiple tubes possibly aggregated side-by-side. Acid oxidation has little effect on this bundle morphology. Rather acid treatment inhibits agglomeration of the bundles. The time evolution of agglomeration is followed by fitting the scattering data to a generalized fractal model. Agglomerates appear immediately after cessation of sonication for untreated fibers but only after hours for treated fibers. Eventually, however, both systems precipitate. C1 Univ Cincinnati, Dept Chem & Mat Engn, Cincinnati, OH 45221 USA. USAF, Res Lab, Mat & Mfg Directorate, MLBCO,WPAFB, Wright Patterson AFB, OH 45433 USA. Los Alamos Natl Lab, Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Schaefer, DW (reprint author), Univ Cincinnati, Dept Chem & Mat Engn, Cincinnati, OH 45221 USA. EM dale.schaefer@uc.edu RI Lian, Jie/A-7839-2010; USAXS, APS/D-4198-2013 NR 25 TC 22 Z9 22 U1 1 U2 8 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 DEC 15 PY 2005 VL 109 IS 49 BP 23351 EP 23357 DI 10.1021/jp055129f PG 7 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300040 PM 16375306 ER PT J AU Kweskin, SJ Komvopoulos, K Somorjai, GA AF Kweskin, SJ Komvopoulos, K Somorjai, GA TI Entropically mediated polyolefin blend segregation at buried sapphire and air interfaces investigated by infrared-visible sum frequency generation vibrational spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SURFACE SEGREGATION; POLYMER BLENDS; POLYSTYRENE; COPOLYMERS; ENRICHMENT; METHYLENE AB The segregation behavior of binary polymer blends at hydrophilic solid sapphire and air interfaces was investigated by infrared-visible sum frequency generation (SFG) vibrational spectroscopy. SFG spectra were collected from a bulk miscible blend consisting of identical molecular weight (similar to 54 000) and similar surface free energy (29-35 dyn/cm) components of atactic polypropylene (aPP) and aspecific poly(ethylene-co-propylene) rubber (aEPR). Characteristic CH resonances of the blend were contrasted with those of the individual components at both buried (sapphire/polymer) and free (air/polymer) interfaces. Preferential segregation of the aPP component was observed after annealing at both air/polymer and sapphire/polymer interfaces. SFG spectra revealed ordering of the polymer backbone segments with the methylene (CH2) groups perpendicular to the surface at the sapphire interface and the methyl (CH3) groups upright at the air interface. The SFG results indicate that the surface composition can be determined from the peak intensities that are characteristic of each component and that conformational entropy played a likely role in surface segregation. aPP occupied a smaller free volume at the surface because of a statistically smaller segment length (aPP is more flexible and has a shorter length). In addition, the high density of the ordered CH3 side branches enhanced the surface activity by allowing the long-chain backbone segments of aPP to order at the surface. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM somorjai@socrates.berkeley.edu NR 15 TC 12 Z9 12 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD DEC 15 PY 2005 VL 109 IS 49 BP 23415 EP 23418 DI 10.1021/jp0539501 PG 4 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300048 PM 16375314 ER PT J AU Alexeev, OS Chin, SY Engelhard, MH Ortiz-Soto, L Amiridis, MD AF Alexeev, OS Chin, SY Engelhard, MH Ortiz-Soto, L Amiridis, MD TI Effects of reduction temperature and metal-support interactions on the catalytic activity Pt/gamma-Al(2)O(3) and Pt/TiO(2) for the oxidation of CO in the presence and absence of H(2) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SURFACE ELEMENTARY STEPS; FUEL-CELL APPLICATIONS; GAS-SHIFT REACTION; TREATED PT-GAMMA-AL2O3 CATALYSTS; RAY-ABSORPTION-SPECTROSCOPY; SITU INFRARED-SPECTROSCOPY; LIGHTING-OFF TESTS; CARBON-MONOXIDE; PT/AL2O3 CATALYST; STRUCTURAL-CHARACTERIZATION AB TiO(2)- and gamma-Al(2)O(3)-supported Pt catalysts were characterized by HRTEM, XPS, EXAFS, and in situ FTIR spectroscopy after activation at various conditions, and their catalytic properties were examined for the oxidation of CO in the absence and presence of H(2) (PROX). When gamma-Al(2)O(3) was used as the support, the catalytic, electronic, and structural properties of the Pt particles formed were not affected substantially by the pretreatment conditions. In contrast, the surface properties and catalytic activity of Pt/TiO(2) were strongly influenced by the pretreatment conditions. In this case, an increase in the reduction temperature led to higher electron density on Pt, altering its chemisorptive properties, weakening the Pt-CO bonds, and increasing its activity for the oxidation of CO. The in situ FTIR data suggest that both the terminal and bridging CO species adsorbed on fully reduced Pt are active for this reaction. The high activity of Pt/TiO(2) for the oxidation of CO can also be attributed to the ability of TiO(2) to provide or stabilize highly reactive oxygen species at the metal-support interface. However, such species appear to be more reactive toward H(2) than CO. Consequently, Pt/TiO(2) shows substantially lower selectivities toward CO oxidation under PROX conditions than Pt/gamma-Al(2)O(3). C1 Univ S Carolina, Dept Chem Engn, Columbia, SC 29208 USA. Pacific NW Natl Lab, WR Riley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Amiridis, MD (reprint author), Univ S Carolina, Dept Chem Engn, Columbia, SC 29208 USA. RI Engelhard, Mark/F-1317-2010 NR 75 TC 89 Z9 89 U1 3 U2 45 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 DEC 15 PY 2005 VL 109 IS 49 BP 23430 EP 23443 DI 10.1021/jp054888v PG 14 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300050 PM 16375316 ER PT J AU Komanicky, V Menzel, A Chang, KC You, H AF Komanicky, V Menzel, A Chang, KC You, H TI Nanofaceted platinum surfaces: A new model system for nanoparticle catalysts SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SULFURIC-ACID; ELECTRODES; CO; PT(111); CARBON; ELECTROOXIDATION; ELECTROSORPTION; ADSORPTION; HYDROGEN AB We present a novel model system for nanoparticle electrocatalysts. A surface consisting of alternating (100) and (111) facets, several nanometers across and nearly 1 mu m long, were self-assembled by annealing Pt single crystal surfaces initially cut at the midpoint between [111] and [100] directions, i.e., Pt(1+root 3 1 1). The formation of these self-assembled arrays of nanofacets was monitored by in-situ surface X-ray scattering. These surfaces were further characterized with scanning probe microscopy and cyclic voltammetry. We found that the Pt(1+root 3 1 1) surface is flat with less than 1 nm rms roughness when it was annealed in argon/hydrogen atmosphere. Then the surface forms nanofacets when it is annealed in pure air. This nanofaceting transition was completely reversible and reproducible. We investigated effects of CO adsorption on the voltammetric characteristics of both hydrogen-annealed and air-annealed surfaces. We found that C)-adsorption/desorption cycles in CO containing electrolyte solution result in considerable modification of blank cyclic voltammograms for the both surfaces. We attributed these differences to the electrochemical annealing of surface defects due to the increased mobility during the cycles. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP You, H (reprint author), Argonne Natl Lab, Div Sci Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. EM hyou@anl.gov RI Chang, Kee-Chul/O-9938-2014; You, Hoydoo/A-6201-2011; Menzel, Andreas/C-4388-2012 OI Chang, Kee-Chul/0000-0003-1775-2148; You, Hoydoo/0000-0003-2996-9483; Menzel, Andreas/0000-0002-0489-609X NR 23 TC 21 Z9 21 U1 3 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 DEC 15 PY 2005 VL 109 IS 49 BP 23543 EP 23549 DI 10.1021/jp0541516 PG 7 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300063 PM 16375329 ER PT J AU Komanicky, V Menzel, A You, H AF Komanicky, V Menzel, A You, H TI Investigation of oxygen reduction reaction kinetics at (111)-(100) nanofaceted platinum surfaces in acidic media SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SINGLE-CRYSTAL SURFACES; SULFURIC-ACID; ELECTRODES; TEMPERATURE; PT(111); STEP AB The oxygen reduction reaction (ORR) was studied on CO-treated and untreated (111)-(100) nanofaceted platinum surfaces [Komanicky et al. J. Phys. Chem. 2005, 109, 23543] in sulfuric and perchloric acids using the rotating disk electrode technique. Activities of nanofaceted surfaces are found to be considerably higher than a simple average of the activities of (111) and (100) surfaces. We find that the high activity in sulfuric acid is consistent with the higher activity of (111) facets. It is due the weaker sulfate adsorption on finite-size (111) surfaces than on (111) single crystal surfaces where the ORR activity is suppressed by strong sulfate adsorption. However, the high activity found in the weakly absorbing perchloric acid cannot be explained by the finite-size effect, since the activities are reportedly insensitive to terrace sizes [Macia, M. D.; et al. J. Electroanal. Chem., 2004, 564, 141]. We propose a cooperative activity, unique to nanoscale objects, which results from oxy species crossing over between adjacent facets in nanometer proximities. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP You, H (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM hyou@anl.gov RI Menzel, Andreas/C-4388-2012; You, Hoydoo/A-6201-2011 OI Menzel, Andreas/0000-0002-0489-609X; You, Hoydoo/0000-0003-2996-9483 NR 21 TC 31 Z9 31 U1 2 U2 22 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 DEC 15 PY 2005 VL 109 IS 49 BP 23550 EP 23557 DI 10.1021/jp054155a PG 8 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300064 PM 16375330 ER PT J AU Laible, PD Kelley, RF Wasielewski, MR Firestone, MA AF Laible, PD Kelley, RF Wasielewski, MR Firestone, MA TI Electron-transfer dynamics of photosynthetic reaction centers in thermoresponsive soft materials SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PRIMARY CHARGE SEPARATION; PHOTOCHEMICAL-REACTION CENTER; CAPSULATUS REACTION CENTERS; RHODOBACTER-SPHAEROIDES; LIPID-BILAYERS; WILD-TYPE; OPTICAL-PROPERTIES; CORE COMPLEX; PROTEIN; MUTANT AB Poly(ethylene glycol)-grafted, lipid-based, thermoresponsive, soft nanostructures are shown to serve as scaffolding into which reconstituted integral membrane proteins, such as the bacterial photosynthetic reaction centers (RCs) can be stabilized, and their packing arrangement, and hence photophysical properties, can be controlled. The self-assembled nanostructures exist in two distinct states: a liquid-crystal line gel phase at temperatures above 21 degrees C and a non-birefringent, reduced viscosity state at lower temperatures. Characterization of the effect of protein introduction on the mesoscopic structure of the materials by P-31 NMR and small-angle X-ray scattering shows that the expanded lamellar structure of the protein-free material is retained. At reduced temperatures, however, the aggregate structure is found to convert from a two-dimensional normal hexagonal structure to a three-dimensional cubic phase upon introduction of the RCs. Structural and functional characteristics of the RCs were determined by ground-state and femtosecond transient absorption spectroscopy. Time-resolved results indicate that the kinetics of primary electron transfer for the RCs in the low-viscosity cold phase of the self-assembled nanostructures are identical to those observed in a detergent-solubilized state in buffered aqueous solutions (similar to 4 ps) over a wide range of protein concentrations and experimental conditions. This is also true for RCs held within the lamellar gel phase at low protein concentrations and at short sample storage times. In contrast are kinetics from samples that are prepared with high RC concentrations and stored for several hours, which display additional kinetic components with extended electron-transfer times (similar to 10- 12 ps). This observation is tentatively attributed to energy transfer between RCs that have laterally (in-plane) organized within the lipid bilayers of the lamellar gel phase prior to charge separation. These results not only demonstrate the use of soft nanostructures as a matrix in which to stabilize and organize membrane proteins but also suggest the possibility of using them to control the interactions between proteins and thus to tune their collective optical/electronic properties. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Ctr Nanofabricat & Mol Self Assembly, Evanston, IL 60208 USA. RP Firestone, MA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM firestone@anl.gov NR 49 TC 12 Z9 12 U1 2 U2 10 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 DEC 15 PY 2005 VL 109 IS 49 BP 23679 EP 23686 DI 10.1021/jp053884n PG 8 WC Chemistry, Physical SC Chemistry GA 992DJ UT WOS:000233864300082 PM 16375348 ER PT J AU Uhrig, D Mays, JW AF Uhrig, D Mays, JW TI Experimental techniques in high-vacuum anionic polymerization SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE anionic polymerization; break-seal; chlorosilane; glassblowing; high-vacuum line; organolithium reagent ID ORGANOLITHIUM COMPOUNDS; BLOCK-COPOLYMERS; SELECTIVE SOLVENTS; BRANCH-POINTS; STYRENE; POLYSTYRENE; ISOPRENE; POLYMERS; FUNCTIONALIZATION; CENTIPEDES AB Experimental methods used in high-vacuum anionic polymerization are described in detail, with extensive illustrations to demonstrate proper procedures and techniques. These descriptions include construction and operation of the vacuum line, handling purification chemicals, ampulization techniques, short-path distillations, initiator synthesis, polymerization procedures, and linking reactions using chlorosilanes. A primary emphasis is placed on safety. We believe that this review of these methods will be useful to scientists working in the field of anionic polymerization and may also benefit other researchers in performing tasks requiring ultra-high-purity reaction conditions. (c) 2005 Wiley Periodicals, Inc. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Ctr Nanophase Mat Sci, Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Uhrig, D (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. EM uhrigdw@ornl.gov RI Uhrig, David/A-7458-2016 OI Uhrig, David/0000-0001-8447-6708 NR 35 TC 188 Z9 189 U1 5 U2 65 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD DEC 15 PY 2005 VL 43 IS 24 BP 6179 EP 6222 DI 10.1002/pola.21016 PG 44 WC Polymer Science SC Polymer Science GA 989BU UT WOS:000233648700001 ER PT J AU Trivedi, R Shin, JH AF Trivedi, R Shin, JH TI Modelling of microstructure evolution in peritectic systems SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Advances in Solidification Processes CY JUN 07-10, 2005 CL Stockholm, SWEDEN DE peritectic microstructure; modelling; peritectic systems; Sn alloys ID CONVECTION; ALLOYS; SOLIDIFICATION AB Theoretical models for directional solidification microstructures are largely developed for steady-state growth conditions. In the two-phase region of peritectic system, a rich variety of two-phase microstructures form in which the two phases often form under non-steady-state conditions and the microstructure evolution depends on the nucleation characteristics of the two phases as well as on the competitive growth of the two phases under dynamical growth conditions. Theoretical models, based on nucleation and diffusive growth, are presented to establish the mechanisms that lead to different microstructure formation in peritectic systems. The critical role played by nucleation in the selection of oscillatory microstructures is discussed, and experimental studies to select different nucleation sites are described. Experimental studies in the Sn-Cd system are carried out in thin capillary samples to minimize fluid flow effects that are dominant in most experiments. Critical conditions for the observation of composite microstructures are evaluated. These results will be presented to support the predictions of the models. (c) 2005 Elsevier B.V. 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. RP Trivedi, R (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. EM trivedi@ameslab.gov NR 15 TC 23 Z9 24 U1 2 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 2005 VL 413 SI SI BP 288 EP 295 DI 10.1016/j.msea.2005.09.027 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 996VI UT WOS:000234202900047 ER PT J AU Lee, JH Kim, HC Jo, CY Kim, SK Shin, JH Liu, S Trivedi, R AF Lee, JH Kim, HC Jo, CY Kim, SK Shin, JH Liu, S Trivedi, R TI Microstructure evolution in directionally solidified Fe-18Cr stainless steels SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Advances in Solidification Processes CY JUN 07-10, 2005 CL Stockholm, SWEDEN DE directional solidification; Fe-18Cr; high velocity cell; cell spacing ID AL-CU ALLOYS; CR-NI ALLOYS; RAPID SOLIDIFICATION; ABSOLUTE STABILITY; DENDRITIC GROWTH; SELECTION MAP; FERRITE; PHASE AB Directional solidification experiments were conducted in commercial Fe-18Cr stainless steels with 0, 3, 5 wt.% Al contents. The unique feature of this alloy system is the narrow freezing range that causes microstructure transitions to occur at relatively low solidification rate which can be achieved by using the directional solidification technique. The velocity range over which dendrites form was found to decrease, whereas the velocity range over which high-velocity cells were present increased significantly, as the aluminum content of the alloy was increased. The transition conditions for dendrite to high-velocity cells were investigated. Cellular and dendritic spacing variation with velocity was also characterized, and the cell spacing was found to vary continuously with growth rate for the low and high-velocity cells. Based on these results, theoretical models are discussed to characterize microstructure transitions from planar to cellular and from dendritic to high-velocity cellular microstructures. (c) 2005 Elsevier B.V. All rights reserved. C1 Changwon Natl Univ, Dept Met, Chang Won, South Korea. Pohang Steel Co, Stainless Res Grp, Pohang, South Korea. Iowa State Univ, Ames Lab, US DOE, Dept Mat Sci & Engn, Ames, IA USA. RP Changwon Natl Univ, Dept Met, Chang Won, South Korea. EM ljh@changwon.ac.kr NR 22 TC 17 Z9 19 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 2005 VL 413 SI SI BP 306 EP 311 DI 10.1016/j.msea.2005.09.021 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 996VI UT WOS:000234202900050 ER PT J AU Wamba, K Hall, C Breidenbach, M Conley, R Odian, A Prescott, CY Rowson, PC Sevilla, J Skarpaas, K DeVoe, R Djurcic, Z Fairbank, WM Gratta, G Green, M Hall, K Hauger, M Jeng, SC Koffas, T LePort, F Leonard, D Martin, JM Neilson, R Ounalli, L Piepke, A Schenker, D Stekhanov, V Vullleumier, JL Waldman, S Weber, P Wodin, J AF Wamba, K Hall, C Breidenbach, M Conley, R Odian, A Prescott, CY Rowson, PC Sevilla, J Skarpaas, K DeVoe, R Djurcic, Z Fairbank, WM Gratta, G Green, M Hall, K Hauger, M Jeng, SC Koffas, T LePort, F Leonard, D Martin, JM Neilson, R Ounalli, L Piepke, A Schenker, D Stekhanov, V Vullleumier, JL Waldman, S Weber, P Wodin, J TI Mobility of thorium ions in liquid xenon SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE liquid xenon calorimeters; ion transport; low background physics; experimental neutrino physics ID KINETIC THEORY; DENSE FLUIDS AB We present a measurement of the Th-226 ion mobility in LXe at 163.0 K and 0.9 bar. The result obtained, 0.240 +/- 0.011 (stat) +/- 0.011 (syst) cm(2)/(kV-s), is compared with a popular model of ion transport. (c) 2005 Elsevier B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. Univ Neuchatel, Inst Phys, CH-2000 Neuchatel, Switzerland. RP Wamba, K (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. EM kwamba@slac.stanford.edu RI Green, Matthew/F-3497-2011; OI Green, Matthew/0000-0002-1958-8030 NR 21 TC 8 Z9 8 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 DEC 15 PY 2005 VL 555 IS 1-2 BP 205 EP 210 DI 10.1016/j.nima.2005.09.023 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 998YD UT WOS:000234354900023 ER PT J AU Pazsit, I Pozzi, SA AF Pazsit, I Pozzi, SA TI Calculation of gamma multiplicities in a multiplying sample for the assay of nuclear materials SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE nuclear safeguards; material accounting; multiplicities; gamma counting; probability generating functions; Monte Carlo ID NEUTRON AB The multiplicities, or factorial moments, of the distribution of the number of neutrons emerging from a fissile sample can be used to identify and quantify fissile isotopes, in particular even-N isotopes of transuranic elements. In fact, the spontaneously emitted source neutrons can induce further fissions in the sample, thereby changing the number distributions of the neutrons leaving the sample, and therefore their multiplicities. The multiplicities increase monotonically with sample mass, hence the measurement of the multiplicities can be used to quantify the sample mass. Analytical expressions for multiplicities that include induced fission effects have been derived for neutrons in the past. These expressions are given as functions of the probability of induced fission per neutron, and have been investigated both by Monte Carlo methods and in experiments using thermal neutron detectors. The object of this paper is to derive analytical formulae for the multiplicities of the gamma photons emitted by both spontaneous and induced fissions, and to perform a quantitative analysis. In addition, neutron and gamma multiplicities are calculated by Monte Carlo simulation using a modified version of the MCNP-PoliMi code. Good agreement is found between the analytical formulae and the Monte Carlo results. The results show the potential advantage of using gamma multiplicities when compared to neutron multiplicities: their higher quantitative values may, in principle, have the effect of leading to a larger sensitivity on the sample mass when compared to the analysis based on neutrons alone. (c) 2005 Elsevier B.V. All rights reserved. C1 Chalmers Univ Technol, Dept Nucl Engn, SE-41296 Gothenburg, Sweden. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Pazsit, I (reprint author), Chalmers Univ Technol, Dept Nucl Engn, Fysikgrand 3, SE-41296 Gothenburg, Sweden. EM imre@nephy.chalmers.se; pozzisa@ornl.gov NR 10 TC 9 Z9 9 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 DEC 15 PY 2005 VL 555 IS 1-2 BP 340 EP 346 DI 10.1016/j.nima.2005.09.006 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 998YD UT WOS:000234354900041 ER PT J AU Yang, HJ Roe, BP Zhu, J AF Yang, HJ Roe, BP Zhu, J TI Studies of boosted decision trees for MiniBooNE particle identification SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE boosted decision trees; artificial neural networks; particle identification; neutrino oscillations; MiniBooNE ID NEURAL-NETWORKS AB Boosted decision trees are applied to particle identification in the MiniBooNE experiment operated at Fermi National Accelerator Laboratory (Fermilab) for neutrino oscillations. Numerous attempts are made to tune the boosted decision trees, to compare performance of various boosting algorithms, and to select input variables for optimal performance. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Stat, Ann Arbor, MI 48109 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Yang, HJ (reprint author), Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. EM yhj@umich.edu RI Yang, Haijun/O-1055-2015 NR 24 TC 32 Z9 32 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 15 PY 2005 VL 555 IS 1-2 BP 370 EP 385 DI 10.1016/j.nima.2005.09.022 PG 16 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 998YD UT WOS:000234354900044 ER PT J AU Raylman, RR Smith, MF Menge, PR AF Raylman, RR Smith, MF Menge, PR TI A Monte-Carlo simulation study of detector array design for dedicated breast metabolic imaging systems SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE PET; PEM; mammography; nuclear medicine imaging ID POSITRON EMISSION MAMMOGRAPHY; PET; PROTOTYPE; CAMERAS; CANCER AB Development of dedicated metabolic breast imaging systems promise to improve the early detection of cancers in women with radiodense and/or cystic breasts. Our group is constructing an imager based on discrete detector arrays that will acquire multi-angle data to produce tomographic images of the breast. The goal of this investigation was to utilize Monte-Carlo simulations to determine the effect of detector element dimensions on breast lesion detectability. Specifically, the Geant4 Application for Tomography Emission (GATE) software package was used to simulate the performance of the new system. Scanners configured with detector arrays having square elements with widths of 1.5, 2 and 3 mm, and thicknesses of 10, 15 and 20 mm were tested. An ellipsoid filled with F-18 containing four spheres with diameters of 5, 4, 3 and 2 mm also filled with F-18 (target-to-background ratio = 8.5:1) was used to simulate a breast with tracer-avid tumors. Images were created with an iterative maximum likelihood expectation maximization (MLEM) image reconstruction algorithm. Lesion detectability was assessed by calculating the peak signal-to-noise ratio for each sphere. Since the GATE software does not model optical effects in the scintillator, a simulation study investigating photon transport in the detector elements using DETECT97 was performed. Results from these studies indicated that narrow (1.5 or 2.0 mm wide) elements 10 or 15 mm in length should produce an imager that would detect breast lesions <= 3 mm in diameter. (c) 2005 Elsevier B.V. All rights reserved. C1 W Virginia Univ, Ctr Adv Imaging, Dept Radiol, Morgantown, WV 26506 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. St Gobain Crystals & Detectors, Newberry, OH USA. RP Raylman, RR (reprint author), W Virginia Univ, Ctr Adv Imaging, Dept Radiol, Morgantown, WV 26506 USA. EM rraylman@wvu.edu NR 19 TC 1 Z9 1 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 DEC 15 PY 2005 VL 555 IS 1-2 BP 403 EP 410 DI 10.1016/j.nima.2005.08.105 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 998YD UT WOS:000234354900047 ER PT J AU Burr, TL Charlton, WS Nakhleh, CW AF Burr, TL Charlton, WS Nakhleh, CW TI Assessing confidence in inferring reactor type and fuel burnup: A Markov chain Monte Carlo approach SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE inverse problem; maximum likelihood; Markov chain Monte Carlo; computer modeling error; spent fuel; safeguards AB A technology to verify operator declarations of reactor type and fuel burnup has been introduced. The approach uses reactor modeling (the "forward model") to predict well-chosen isotope ratios as a function of reactor type and burnup. Mass spectrometry measurements of these ratios are then used to infer reactor type and burnup, (via a maximum likelihood solution to "the inverse problem"). We extend the previous maximum likelihood solution to this inverse problem by using Markov Chain Monte Carlo to simulate observations from the posterior distribution for reactor type and burnup. This provides an alternate estimation strategy, an estimate of the confidence in the inferred reactor type and burnup, and improves prediction performance. We also investigate the impact of increased error variance as a step toward including the effect of computer-code uncertainty. (c) 2005 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Stat Grp, Los Alamos, NM 87545 USA. Texas A&M Univ, College Stn, TX USA. Los Alamos Natl Lab, Thermonucl Applicat Grp, Los Alamos, NM 87545 USA. RP Burr, TL (reprint author), Los Alamos Natl Lab, Stat Grp, MS F600, Los Alamos, NM 87545 USA. EM tburro@lanl.gov NR 14 TC 2 Z9 2 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 DEC 15 PY 2005 VL 555 IS 1-2 BP 426 EP 434 DI 10.1016/j.nima.2005.09.041 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 998YD UT WOS:000234354900050 ER PT J AU Kitano, R Nomura, Y AF Kitano, R Nomura, Y TI A solution to the supersymmetric fine-tuning problem within the MSSM SO PHYSICS LETTERS B LA English DT Article ID EVEN HIGGS BOSONS; STANDARD MODEL; ELECTROWEAK BREAKING; SOFT TERMS; MASSES; SUPERGRAVITY; UNIFICATION; SCALE AB Weak scale supersymmetry has a generic problem of fine-tuning in reproducing the correct scale for electroweak symmetry breaking. The problem is particularly severe in the minimal supersymmetric extension of the Standard Model (MSSM). We present a solution to this problem that does not require an extension of the MSSM at the weak scale. Superparticle masses are generated by a comparable mixture of moduli and anomaly mediated contributions, and the messenger scale of supersymmetry breaking is effectively lowered to the TeV region. Crucial elements for the solution are a large A term for the top squarks and a small B term for the Higgs doublets. Requiring no fine-tuning worse than 20%, we obtain rather sharp predictions on the spectrum. The gaugino masses are almost universal at the weak scale with the mass between 450 and 900 GeV. The squark and slepton masses are also nearly universal at the weak scale with the mass a factor of root 2- smaller than that of the gauginos. The only exception is the top squarks whose masses split from the other squark masses by about m(t)/root 2-. The lightest Higgs boson mass is smaller than 120 GeV, while the ratio of the vacuum expectation values for the two Higgs doublets, tan beta, is larger than about 5. The lightest superparticle is the neutral Higgsino of the mass below 190 GeV, which can be dark matter of the universe. The mass of the lighter top squark can be smaller than 300 GeV, which may be relevant for Run II at the Tevatron. (c) 2005 Elsevier B.V All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM kitano@slac.stanford.edu OI Nomura, Yasunori/0000-0002-1497-1479 NR 52 TC 161 Z9 161 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 DEC 15 PY 2005 VL 631 IS 1-2 BP 58 EP 67 DI 10.1016/j.physletb.2005.10.003 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 988MS UT WOS:000233605900008 ER PT J AU Levinson, R Berdahl, P Akbari, H AF Levinson, R Berdahl, P Akbari, H TI Solar spectral optical properties of pigments - Part I: model for deriving scattering and absorption coefficients from transmittance and reflectance measurements SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE pigment characterization; solar spectral optical properties; Kubelka-Munk theory; refractive-index discontinuity; cool roofs ID RADIATIVE-TRANSFER MODELS; MULTIPLE-SCATTERING; TURBID MEDIA; LIGHT; PARAMETERS; PARTICLES AB The suitability of a pigment for inclusion in "cool" colored coatings with high solar reflectance can be determined from its solar spectral backscattering and absorption coefficients. Pigment characterization is performed by dispersing the pigment into a transparent film, then measuring spectral transmittance and reflectance. Measurements of the reflectance of film samples on black and white substrates are also used. A model for extracting the spectral backscattering coefficient S and absorption coefficient K from spectrometer measurements is presented. Interface reflectances complicate the model. The film's diffuse reflectance and transmittance measurements are used to determine S and K as functions of a wavelength-independent model parameter sigma that represents the ratio of forward to total scattering. sigma is used to estimate the rate at which incident collimated light becomes diffuse, and is determined by fitting the measured film reflectance backed by black. A typical value is sigma = 0.8. Then, the measured film reflectance backed by white is compared with a computed value as a self-consistency check. Measurements on several common pigments are used to illustrate the method. Published by Elsevier B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Levinson, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM RMLevinson@LBL.gov; PHBerdahl@LBL.gov; H_Akbari@LBL.gov NR 48 TC 131 Z9 148 U1 3 U2 39 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD DEC 15 PY 2005 VL 89 IS 4 BP 319 EP 349 DI 10.1016/j.solmat.2004.11.012 PG 31 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 978GF UT WOS:000232860900001 ER PT J AU Levinson, R Berdahl, P Akbari, H AF Levinson, R Berdahl, P Akbari, H TI Solar spectral optical properties of pigments - Part II: survey of common colorants SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE pigment characterization; solar spectral optical properties; Kubelka-Munk absorption and backscattering coefficients; cool roofs; titanium dioxide ID ELECTRICAL-CONDUCTION; COATED FLAKES; SCATTERING; PAINT; FILMS; IRON AB Various pigments are characterized by determination of parameters S (backscattering) and K (absorption) as functions of wavelength in the solar spectral range of 300-2500 nm. Measured values of S for generic titanium dioxide (rutile) white pigment are in rough agreement with values computed from the Mie theory, supplemented by a simple multiple scattering model. Pigments in widespread use are examined, with particular emphasis on those that may be useful for formulating non-white materials that can reflect the near-infrared (NIR) portion of sunlight, such as the complex inorganic color pigments (mixed metal oxides). These materials remain cooler in sunlight than comparable NIR-absorbing colors. NIR-absorptive pigments are to be avoided. High NIR reflectance can be produced by a reflective metal substrate, an NIR-reflective underlayer, and/or by the use of a pigment that scatters strongly in the NIR. Published by Elsevier B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Levinson, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM RMLevinson@LBL.gov; PHBerdahl@LBL.gov; H_Akbari@LBL.gov NR 27 TC 134 Z9 143 U1 8 U2 49 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD DEC 15 PY 2005 VL 89 IS 4 BP 351 EP 389 DI 10.1016/j.solmat.2004.11.013 PG 39 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 978GF UT WOS:000232860900002 ER PT J AU Yantasee, W Timchalk, C Fryxell, GE Dockendorff, BP Lin, YH AF Yantasee, W Timchalk, C Fryxell, GE Dockendorff, BP Lin, YH TI Automated portable analyzer for lead(II) based on sequential flow injection and nanostructured electrochemical sensors SO TALANTA LA English DT Article; Proceedings Paper CT 13th International Conference on Flow Injection Analysis CY APR 24-29, 2005 CL Las Vegas, NV DE automated portable analyzer; sequential flow injection; nanostructured electrochemical sensors ID SELF-ASSEMBLED MONOLAYERS; MESOPOROUS SILICA SAMMS; FUNCTIONALIZED MONOLAYERS; ACTINIDE SEQUESTRATION; SUPPORTS; SORBENTS AB A fully automated portable analyzer for toxic metal ion detection based on a combination of a nanostructured electrochemical sensor and a sequential flow injection system has been developed in this work. The sensor was fabricated from a carbon paste electrode modified with acetamide phosphonic acid self-assembled monolayer on mesoporous silica (Ac-Phos SAMMS) which was embedded in a very small wall-jet (flow-onto) electrochemical cell. The electrode is solid-state and mercury-free. Samples and reagents were injected into the system and flowed through the electrochemical cell by a user programmable sequential flow technique which required minimal volume of samples and reagents and allowed the automation of the analyzer operation. The portable analyzer was evaluated for lead (Pb) detection due to the excellent binding affinity between Pb and the functional groups of Ac-Phos SAMMS as well as the great concern for Pb toxicity. Linear calibration curve was obtained in a low concentration range (1-25 ppb of Pb(11)). The reproducibility was excellent; the percent relative standard deviation was 2.5 for seven consecutive measurements of 10 ppb of Pb(II) solution. Excess concentrations of Ca, Ni, Co, Zn, and Mn ions in the solutions did not interfere with detection of Pb, due to the specificity and the large number of the functional groups on the electrode surface. The electrode was reliable for at least 90 measurements over 5 days. This work is an important milestone in the development of the next-generation metal ion analyzers that are portable, fully automated, and remotely controllable. (c) 2005 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Lin, YH (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999,MS,K8093, Richland, WA 99352 USA. EM Yuehe.Lin@pnl.gov RI Lin, Yuehe/D-9762-2011 OI Lin, Yuehe/0000-0003-3791-7587 NR 20 TC 27 Z9 28 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD DEC 15 PY 2005 VL 68 IS 2 BP 256 EP 261 DI 10.1016/j.talanta.2005.07.013 PG 6 WC Chemistry, Analytical SC Chemistry GA 987AP UT WOS:000233491100017 PM 18970314 ER PT J AU Wang, WG Davis, KJ Cook, BD Bakwin, PS Yi, CX Butler, MP Ricciuto, DA AF Wang, WG Davis, KJ Cook, BD Bakwin, PS Yi, CX Butler, MP Ricciuto, DA TI Surface layer CO2 budget and advective contributions to measurements of net ecosystem-atmosphere exchange of CO2 SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE advection; atmospheric surface layer; carbon dioxide budget; net ecosystem-atmosphere exchange; atmospheric boundary layer budget ID CARBON-DIOXIDE EXCHANGE; TALL VEGETATION; BOUNDARY-LAYER; MICROMETEOROLOGICAL OBSERVATIONS; NORTHERN WISCONSIN; EDDY COVARIANCE; COMPLEX TERRAIN; AIR EXCHANGE; WATER-VAPOR; FOREST AB The aim of this case study is to examine the surface layer CO2 budget and possible impacts of advection on the 20 km scale on estimates of net ecosystem-atmosphere exchange (NEE) of CO2 under windy conditions. The advection terms in the CO2 mixing ratio conservation equation are computed using data from two flux towers 20 km apart in a forested area in Wisconsin, USA. The data are analyzed when the winds blow continuously from the southeast (SE) or from the northwest (NW) under windy conditions for 5 h or longer during the months of May through September of 1999 and 2000. Compared to the vertical turbulent flux, the contribution of horizontal flux divergence is negligible on the scale of 20 km at all times. The contributions of both horizontal and vertical advection terms to NEE estimates are negligible in the day. The mean nocturnal vertical and horizontal components of the advective fluxes have opposite signs and are of the same order of magnitude. Considering only one of the two advection terms in NEE calculation would be inappropriate. On the spatial scale specified, the contribution of horizontal advection is negative and can be 10% of NEE at night under sustained SE winds. The contribution of vertical advection is positive and is about 20% of NEE for the same wind direction. The contribution of nocturnal advection is negligible for most cases with sustained NW winds. The evaluation of the advective effects is still incomplete only from this dataset and significant contribution of advection on the scales smaller than 20 km is not ruled out because the 20-km scale may not be the primary scale of the heterogeneous distributions of land cover and soils. Nevertheless, the analyses suggest that significant errors due to the neglect of the impacts of the land cover and soil heterogeneity at larger scales (than local) are possible in one-dimensional eddy-covariance NEE measurements under windy conditions; these measurements are usually selected to describe nighttime NEE at this site and, therefore, the likely errors may deserve attention. The analyses also suggest that impacts of both advection terms within the surface layer on NEE estimates from the atmospheric boundary budget method could be negligible in the day but significant at night. More comprehensive experiments are needed to completely assess the advection issue. (c) 2005 Elsevier B.V. All rights reserved. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. RP Wang, WG (reprint author), Pacific NW Natl Lab, POB 999,K9-30, Richland, WA 99352 USA. EM wang@essc.psu.edu RI Wang, Weiguo/B-4948-2009; Cook, Bruce/M-4828-2013; Yi, Chuixiang/A-1388-2013; Ricciuto, Daniel/I-3659-2016 OI Cook, Bruce/0000-0002-8528-000X; Ricciuto, Daniel/0000-0002-3668-3021 NR 36 TC 15 Z9 16 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD DEC 14 PY 2005 VL 135 IS 1-4 BP 202 EP 214 DI 10.1016/j.agrformet.2005.11.018 PG 13 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 021WY UT WOS:000236017800018 ER PT J AU Esen, S Souers, PC Vitello, P AF Esen, S Souers, PC Vitello, P TI Prediction of the non-ideal detonation performance of commercial explosives using the DeNE and JWL plus plus codes SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE non-ideal detonation; commercial explosives; detonation velocity; curvature; explosive/rock interface AB The non-ideal detonation performance of two commercial explosives is determined using the DeNE and JWL++ codes. These two codes differ in that DeNE is based on a pseudo-one-dimensional theory which is valid on the central stream-tube and capable of predicting the non-ideal detonation characteristics of commercial explosives as a function of the explosive type, rock properties and blasthole diameter. On the other hand, JWL++ is a hydrocode running in a 2-D arbitrary Lagrangian-Eulerian code with CALE-like properties and can determine the flow properties in all stream lines within the reaction zone. The key flow properties (detonation velocity, pressure, specific volume, extent of reaction and reaction zone length) at the sonic locus on the charge axis have been compared. In general, it is shown that the flow parameters determined using both codes agree well. The pressure contours determined using the JWL++ are analysed in detail for two explosives at 165 mm blastholes confined in limestone and kimberlite with a view to further investigate the explosive/rock interface. The DeNE and JWL++ codes have been validated using the measured in-hole detonation velocity data. Copyright (c) 2005 John Wiley & Sons, Ltd. C1 Swedish Blasting Res Ctr, S-10074 Stockholm, Sweden. Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. RP Esen, S (reprint author), Lulea Univ Technol, Swebrec, Box 47047,Mejerivagen 4,T Stop Liljeholmen, S-10074 Stockholm, Sweden. EM sedat@svebefo.se NR 23 TC 3 Z9 3 U1 1 U2 5 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD DEC 14 PY 2005 VL 64 IS 14 BP 1889 EP 1914 DI 10.1002/nme.1424 PG 26 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 992IJ UT WOS:000233877300003 ER PT J AU DeSain, JD Jusinski, LE Taatjes, CA AF DeSain, JD Jusinski, LE Taatjes, CA TI Temperature dependence and deuterium kinetic isotope effects in the HCO plus NO reaction SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE chemical kinetics; HCO; combustion chemistry ID FLUORESCENCE EXCITATION; FORMYL RADICALS; INFRARED CHEMILUMINESCENCE; MOLECULAR-OXYGEN; SUPERSONIC JET; RATE-CONSTANT; NITRIC-OXIDE; AB-INITIO; LASER; SPECTROSCOPY AB The reactions of HCO and DCO with NO have been measured by the laser photolysis/continuous-wave (CW) laser-induced fluorescence (LIF) method from 296 to 623K, probing the ((B) over tilde (2) A' <- (X) over tilde (2) A') HCO (DCO) system. The HCO +NO rate coefficient is (1.81 +/- 0.10) x 10(-11) cm(3) molecule(-1) s(-1) and the DCO +NO rate coefficient is (1.61 +/- 0.12) x 10(-11) cm(3) molecule(-1) s(-1) at 296K. Both rate coefficients decrease with increasing temperature between 296 and 623 K. The kinetic isotope effect is k(H)/k(D) = 1.12 +/- 0.09 at 296 K and increases to 1.25 +/- 0.15 at 623 K. The normal kinetic isotope effect supports abstraction as the principal mechanism for the reaction, in agreement with recent computational results. (c) 2005 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Taatjes, CA (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9055, Livermore, CA 94551 USA. EM cataatj@sandia.gov NR 28 TC 2 Z9 2 U1 0 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD DEC 14 PY 2005 VL 176 IS 1-3 BP 149 EP 154 DI 10.1016/j.jphotochem.2005.07.023 PG 6 WC Chemistry, Physical SC Chemistry GA 991BQ UT WOS:000233787600016 ER PT J AU Ben-Naim, E Krapivsky, PL AF Ben-Naim, E Krapivsky, PL TI Polymerization with freezing SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID MOLECULAR-SIZE DISTRIBUTION; STOCHASTIC AGGREGATION; ONE DIMENSION; MODELS; COAGULATION; POLYMERS; EQUATIONS; KINETICS; GELATION AB Irreversible aggregation processes involving reactive and frozen clusters are investigated Using the rate equation approach. In aggregation events, two clusters join irreversibly to form a larger cluster; additionally, reactive clusters may spontaneously freeze. Frozen clusters do not participate in merger events. Generally, freezing controls the nature of the aggregation process, as demonstrated by the final distribution of frozen clusters. The cluster mass distribution has a power-law tail, F-k similar to k(-y), when the freezing process is sufficiently slow. Different exponents, y = 1 and 3, are found for the constant and the product aggregation rates, respectively. For the latter case, the standard polymerization model, either no gels, or a single gel, or even multiple gels, may be produced. 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 28 TC 6 Z9 6 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD DEC 14 PY 2005 VL 17 IS 49 SI SI BP S4249 EP S4262 DI 10.1088/0953-8984/17/49/018 PG 14 WC Physics, Condensed Matter SC Physics GA 009XN UT WOS:000235147000019 ER PT J AU Tsige, M Grest, GS AF Tsige, M Grest, GS TI Solvent evaporation and interdiffusion in polymer films SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; GRADIENT-DRIVEN DIFFUSION; DIBLOCK COPOLYMERS; BLOCK-COPOLYMER; MELTS; EQUILIBRIUM; TRANSPORT; NETWORKS; COLLAPSE; GASES AB Solvent evaporation from homopolymer and heteropolymer films along with the interdiffusion of solvent into these films are studied by molecular dynamics simulations. Due to the high viscosity of polymer melts, in many cases polymer films are made by first dissolving the polymer in a low viscosity solvent, spreading the solution on a substrate and subsequently evaporating the solvent. Here we Study the last part of this process, namely the evaporation of solvent from a polymer film. As the solvent evaporates, the polymer density at the film/vapour interface is found to increase sharply, creating a polymer density gradient which acts as a barrier for further solvent evaporation. For both homopolymer and heteropolymer films, the rate of solvent evaporation is found to decrease exponentially as a function of time. For multiblock copolymer films the resulting domain structure is found to be strongly affected by the relative stiffness of the two blocks. The reverse process, namely the interdiffusion of solvent into a polymer film, is also studied. For homopolymer films the weight gain by the film scales as t(1/2), which is expected for Fickian diffusion. The diffusivity D(c) determined from the one-dimensional Fick's diffusion equation agrees well with that calculated from the corrected diffusion constant using the Darken equation. Far above the polymer glass transition temperature, D(c) is nearly independent of concentration. However, as the temperature decreases D(c) is found to depend strongly on the state of the polymer and is related to the shape of the solvent concentration profile. Finally, the swelling of a multiblock copolymer film in which the stiffer block is below its glass transition temperature is also studied. While the solvent swells only the softer block of the copolymer, the weight gain by the film remains Fickian. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tsige, M (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM mtsige@sandia.gov; gsgrest@sandia.gov NR 34 TC 24 Z9 24 U1 4 U2 45 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD DEC 14 PY 2005 VL 17 IS 49 SI SI BP S4119 EP S4132 DI 10.1088/0953-8984/17/49/008 PG 14 WC Physics, Condensed Matter SC Physics GA 009XN UT WOS:000235147000009 ER PT J AU Pauzauskie, PJ Talaga, D Seo, K Yang, PD Lagugne-Labarthet, F AF Pauzauskie, PJ Talaga, D Seo, K Yang, PD Lagugne-Labarthet, F TI Polarized Raman confocal microscopy of single gallium nitride nanowires SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GAN; SCATTERING; SILICON C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Bordeaux 1, CNRS, UMR 5803, Lab PhysicoChim Mol, F-33405 Talence, France. RP Yang, PD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM p_yang@berkeley.edu; f.lagugne@lpcm.u-bordeaux1.fr RI Seo, Kwanyong/D-3083-2011; SEO, KWANYONG/B-2031-2013; Pauzauskie, Peter/A-1316-2014 OI SEO, KWANYONG/0000-0002-8443-7933; NR 13 TC 54 Z9 54 U1 1 U2 17 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 DEC 14 PY 2005 VL 127 IS 49 BP 17146 EP 17147 DI 10.1021/ja056006b PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 992XO UT WOS:000233917500009 PM 16332037 ER PT J AU Yoon, WS Balasubramanian, M Chung, KY Yang, XQ McBreen, J Grey, CP Fischer, DA AF Yoon, WS Balasubramanian, M Chung, KY Yang, XQ McBreen, J Grey, CP Fischer, DA TI Investigation of the charge compensation mechanism on the electrochemically Li-ion deintercalated Li1-xCo1/3Ni1/3Mn1/3O2 electrode system by combination of soft and hard x-ray absorption spectroscopy SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID LINI0.5MN0.5O2 CATHODE MATERIAL; FINE-STRUCTURE; RECHARGEABLE BATTERIES; MULTIPLE-SCATTERING; OK-EDGE; LICOO2; DICHROISM; EXAFS AB In situ hard X-ray absorption spectroscopy (XAS) at metal K-edges and soft XAS at O K-edge and metal L-edges have been carried out during the first charging process for the layered Li1-xCo1/3Ni1/3Mn1/3O2 cathode material. The metal K-edge XANES results show that the major charge compensation at the metal site during Li-ion deintercalation is achieved by the oxidation of Ni2+ ions, while the manganese ions and the cobalt ions remain mostly unchanged in the Mn4+ and Co3+ state. These conclusions are in good agreement with the results of the metal K-edge EXAFS data. Metal L-edge XAS results at different charge states in both the FY and PEY modes show that, unlike Mn and Co ions, Ni ions at the surface are oxidized to Ni3+ during charge, whereas Ni ions in the bulk are further oxidized to Ni4+ during charge. From the observation of O K-edge XAS results, we can conclude that a large portion of the charge compensation during Li-ion deintercalation is achieved in the oxygen site. By comparison to our earlier results on the Li1-xNi0.5Mn0.5O2 system, we attribute the active participation of oxygen in the redox process in Li1-xCo1/3Ni1/3Mn1/3O2 to be related to the presence of Co in this system. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Yoon, WS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM wonsuby@bnl.gov RI Chung, Kyung Yoon/E-4646-2011; Yoon, Won-Sub/H-2343-2011 OI Chung, Kyung Yoon/0000-0002-1273-746X; NR 37 TC 114 Z9 116 U1 10 U2 97 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 DEC 14 PY 2005 VL 127 IS 49 BP 17479 EP 17487 DI 10.1021/ja0530568 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 992XO UT WOS:000233917500072 PM 16332100 ER PT J AU Engtrakul, C Davis, MF Gennett, T Dillon, AC Jones, KM Heben, MJ AF Engtrakul, C Davis, MF Gennett, T Dillon, AC Jones, KM Heben, MJ TI Protonation of carbon single-walled nanotubes studied using C-13 and H-1-C-13 cross polarization nuclear magnetic resonance and Raman spectroscopies SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ANGLE-SPINNING NMR; DEUTERIUM ATTACHMENT; CHARGE-TRANSFER; WATER; STATE; SCATTERING; ACID; TRANSFORMATION; SUPERACIDS; ADSORPTION AB The reversible protonation of carbon single-walled nanotubes (SWNTs) in sulfuric acid and Nafion was investigated using solid-state nuclear magnetic resonance (NMR) and Raman spectroscopies. Magic-angle spinning (MAS) was used to obtain high-resolution C-13 and H-1-C-13 cross polarization (CP) NMR spectra. The C-13 NMR chemical shifts are reported for bulk SWNTs, H2SO4-treated SWNTs, SWNT-Nafion polymer composites, SWNT-AQ55 polymer composites, and SWNTs in contact with water. Protonation occurs without irreversible oxidation of the nanotube substrate via a charge-transfer process. This is the first report of a chemically induced change in a SWNT C-13 resonance brought about by a reversible interaction with an acidic proton, providing additional evidence that carbon nanotubes behave as weak bases. Cross polarization was found to be a powerful technique for providing an additional contrast mechanism for studying nanotubes in contact with other chemical species. The CP studies confirmed polarization transfer from nearby protons to nanotube carbon atoms. The CP technique was also applied to investigate water adsorbed on carbon nanotube surfaces. Finally, the degree of bundling of the SWNTs in Nafion films was probed with the H-1-C-13 CP-MAS technique. C1 Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. Natl Renewable Energy Lab, Natl Bioenergy Ctr, Golden, CO 80401 USA. Rochester Inst Technol, Dept Chem, Rochester, NY 14623 USA. Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. EM chaiwat_engtrakul@nrel.gov; mark_davis@nrel.gov RI Engtrakul, Chaiwat/H-5634-2011; OI davis, mark/0000-0003-4541-9852 NR 58 TC 54 Z9 54 U1 1 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 14 PY 2005 VL 127 IS 49 BP 17548 EP 17555 DI 10.1021/ja0557886 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 992XO UT WOS:000233917500079 PM 16332107 ER PT J AU Li, JH Boschek, CB Xiong, YJ Sacksteder, CA Squier, TC Bigelow, DJ AF Li, JH Boschek, CB Xiong, YJ Sacksteder, CA Squier, TC Bigelow, DJ TI Essential role for Pro(21) in phospholamban for optimal inhibition of the Ca-ATPase SO BIOCHEMISTRY LA English DT Article ID CARDIAC SARCOPLASMIC-RETICULUM; DEPENDENT PROTEIN-KINASE; NMR SOLUTION STRUCTURE; DODECYLPHOSPHOCHOLINE MICELLES; MONOMERIC PHOSPHOLAMBAN; FUNCTIONAL ASSOCIATION; MAGNETIC-RESONANCE; STRUCTURAL-CHANGES; TERMINAL FRAGMENT; CALCIUM-BINDING AB We have investigated the functional role of the flexible hinge region centered near the sequence TIEMP21 which connects the N-terminal cytosolic and C-terminal membrane-spanning helical domains of phospholamban (PLB). Specifically, we ask if the conformation of this region is important to attain optimal inhibitory interactions with the Ca-ATPase. A genetically engineered PLB mutant was constructed in which Pro(21) was mutated to an alanine (P21A-PLBC); in this construct, all three transmembrane cysteines were substituted with alanines to stabilize the monomeric form of PLB, and a unique cysteine was introduced at position 24 near the hinge element (A24C), permitting the site-specific attachment of fluorescein-5-maleimide (FMal) to monitor structure changes. In agreement with prior measurements in cardiac SR microsomes, the calcium concentration associated with half-maximal activation (Ca-1/2) of the Ca-ATPase, 290 +/- 10 nM, is shifted to 580 +/- 20 nM when co-reconstituted with PLBc (Pro21) as a result of a reduction in the cooperativity associated with the calcium-dependent structural transition. Kinetic simulations indicate that PLBc association with the Ca-ATPase results in a 75% reduction in the equilibrium constant associated with the formation of the second high-affinity calcium binding site. In comparison, there is a 43% reduction in KCa1/2 upon reconstitution of the Ca-ATPase with P21A-PLBC, which can be simulated by decreasing the equilibrium constant associated with the calcium-dependent structural activation by 50%. The diminished inhibitory action of P21A-PLBC is associated with alterations in the structure of the hinge element, as evidenced by the diminished solvent accessibility of FMal relative to the native structure. Likewise, increases in the alpha-helical content and decreases in the mobility of the carboxyl-terminal domain of P21A-PLBC are observed using circular dichroism and fluorescence spectroscopy. Collectively, these results indicate that the overall dimensions of the carboxyl-terminal domain of PLB are increased through a stabilization of secondary structural elements upon mutation in P21A-PLBC that result. in a reduction in the ability of the amino-terminal cytosolic portion of PLB to productively inhibit the Ca-ATPase. Further, these results suggest that the unstructured characteristics of the flexible hinge region in PLB are critical for optimal inhibitory interactions with the Ca-ATPase and suggest its role as a conformational switch. C1 Pacific NW Natl Lab, Cell Biol & Biochem Grp, Div Biol Sci, Richland, WA 99352 USA. RP Bigelow, DJ (reprint author), Pacific NW Natl Lab, Cell Biol & Biochem Grp, Div Biol Sci, POB Box 999,MS P7-56, Richland, WA 99352 USA. EM diana.bigelow@pnl.gov RI Xiong, Yijia/C-1341-2011 FU NHLBI NIH HHS [HL64031] NR 48 TC 7 Z9 7 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD DEC 13 PY 2005 VL 44 IS 49 BP 16181 EP 16191 DI 10.1021/bi051075o PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 992QH UT WOS:000233898400024 PM 16331978 ER PT J AU Derbyshire, ER Tran, R Mathies, RA Marletta, MA AF Derbyshire, ER Tran, R Mathies, RA Marletta, MA TI Characterization of nitrosoalkane binding and activation of soluble guanylate cyclase SO BIOCHEMISTRY LA English DT Article ID RESONANCE RAMAN-SPECTROSCOPY; IRON-HISTIDINE BOND; NITRIC-OXIDE; CARBON-MONOXIDE; LIGAND-BINDING; HEME DOMAIN; MYOGLOBIN; COMPLEXES; HEMOGLOBIN; KINETICS AB Soluble guanylate cyclase (sGC) is the primary receptor for the signaling agent nitric oxide (NO). Electronic absorption and resonance Raman spectroscopy were used to show that nitrosoalkanes bind to the heme of sGC to form six-coordinate, low-spin complexes. In the sGC-nitrosopentane complex, a band assigned to an Fe-N stretching vibration is observed at 543 cm(-1) which is similar to values reported for other six-coordinate NO-bound hemoproteins. Nitrosoalkanes activate sGC 2-6-fold and synergize with YC-1, a synthetic benzylinclazole derivative, to activate the enzyme 11-47-fold. In addition, the observed off-rates of nitrosoalkanes from sGC were found to be dependent on the alkyl chain length. A linear correlation was found between the observed off-rates and the alkyl chain length which suggests that the sGC heme has a large hydrophobic distal ligand-binding pocket. Together, these data show that nitrosoalkanes are a novel class of heme-based sGC activators and suggest that heme ligation is a general requirement for YC-1 synergism. C1 Univ Calif Berkeley, Dept Chem, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Div Phys Biosci, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Marletta, MA (reprint author), Univ Calif Berkeley, Dept Chem, Lawrence Berkeley Lab, 211 Lewis Hall, Berkeley, CA 94720 USA. EM marletta@berkeley.edu FU NIGMS NIH HHS [T32 GM07232] NR 49 TC 14 Z9 15 U1 1 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 DEC 13 PY 2005 VL 44 IS 49 BP 16257 EP 16265 DI 10.1021/bi0515671 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 992QH UT WOS:000233898400032 PM 16331986 ER PT J AU Karow, DS Pan, DH Davis, JH Behrends, S Mathies, RA Marletta, MA AF Karow, DS Pan, DH Davis, JH Behrends, S Mathies, RA Marletta, MA TI Characterization of functional heme domains from soluble guanylate cyclase SO BIOCHEMISTRY LA English DT Article ID RESONANCE RAMAN-SPECTROSCOPY; DISTAL POCKET POLARITY; NITRIC-OXIDE ADDUCTS; CARBON-MONOXIDE; LIGAND-BINDING; OXYGENASE COMPLEX; BETA(2) SUBUNIT; CYTOCHROME-C'; NO-HEME; MYOGLOBIN AB Soluble guanylate cyclase (sGC) is a heterodimeric, nitric oxide (NO)-sensing hemoprotein composed of two subunits, alpha 1 and beta 1. NO binds to the heme cofactor in the 1 subunit, forming a five-coordinate NO complex that activates the enzyme several hundred-fold. In this paper, the heme domain has been localized to the N-terminal 194 residues of the beta 1 subunit. This fragment represents the smallest construct of the PI subunit that retains the ligand-binding characteristics of the native enzyme, namely, tight affinity for NO and no observable binding of O(2). A functional heme domain from the rat beta 2 subunit has been localized to the first 217 amino acids beta 2(1-217). These proteins are similar to 40% identical to the rat beta 1 heme domain and form five-coordinate, low-spin NO complexes and six-coordinate, low-spin CO complexes. Similar to sGC, these constructs have a weak Fe-His stretch [208 and 207 cm(-1) for 1(1194) and beta 2(1-217), respectively]. beta 2(1-217) forms a CO complex that is very similar to sGC and has a high v(CO) stretching frequency at 1994 cm(-1). The autoxidation rate of beta 1(1-194) was 0.073/min, while the beta 2(1-217) was substantially more stable in the ferrous form with an autoxidation rate of 0.003/min at 37 degrees C. This paper has identified and characterized the minimum functional ligand-binding heme domain derived from sGC, providing key details toward a comprehensive characterization. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Michigan, Mol & Cellular Biol Program, Ann Arbor, MI 48109 USA. Univ Toronto, Dept Pharmacol, Toronto, ON M5S 1A8, Canada. Lawrence Berkeley Lab, Div Phys Biosci, Berkeley, CA 94720 USA. RP Marletta, MA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM marletta@berkeley.edu RI Behrends, Sonke/A-2551-2010; OI Behrends, Sonke/0000-0002-9068-0729; Davis, Joseph/0000-0002-8858-8907 FU NEI NIH HHS [EY-02051]; NIGMS NIH HHS [R01 GM070671, R01 GM070671-01A2] NR 42 TC 52 Z9 54 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD DEC 13 PY 2005 VL 44 IS 49 BP 16266 EP 16274 DI 10.1021/bi051601b PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 992QH UT WOS:000233898400033 PM 16331987 ER PT J AU Shvareva, TY Beitz, JV Duin, EC Albrecht-Schmitt, TE AF Shvareva, TY Beitz, JV Duin, EC Albrecht-Schmitt, TE TI Polar open-framework structure, optical properties, and electron paramagnetic resonance of the mixed-metal uranyl phosphate Cs-2[UO2(VO2)(2)(PO4)(2)]center dot 0.59H(2)O SO CHEMISTRY OF MATERIALS LA English DT Article ID BOND-VALENCE PARAMETERS; CRYSTAL-STRUCTURES; ION-EXCHANGE; URANIUM; MOLYBDATES; CATALYSTS; RB; TL C1 Auburn Univ, Dept Chem & Biochem, Auburn, AL 36849 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Albrecht-Schmitt, TE (reprint author), Auburn Univ, Dept Chem & Biochem, Auburn, AL 36849 USA. NR 23 TC 14 Z9 14 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD DEC 13 PY 2005 VL 17 IS 25 BP 6219 EP 6222 DI 10.1021/cm052079i PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 991WU UT WOS:000233846100003 ER PT J AU Michel, FM Antao, SM Chupas, PJ Lee, PL Parise, JB Schoonen, MAA AF Michel, FM Antao, SM Chupas, PJ Lee, PL Parise, JB Schoonen, MAA TI Short- to medium-range atomic order and crystallite size of the initial FeS precipitate from pair distribution function analysis SO CHEMISTRY OF MATERIALS LA English DT Article ID PYRITE FORMATION; MACKINAWITE FES; POWDER DIFFRACTION; AQUEOUS-SOLUTIONS; HYDROGEN-SULFIDE; TETRAGONAL FES; IRON SULFIDES; COPRECIPITATION; MONOSULFIDE; REFINEMENT AB Pair distribution function analysis (PDF) of X-ray diffraction data, collected at 11-IDC and 1-ID at the Advanced Photon Source, provides the atomic structure and primary crystallite size of FeS both freshly precipitated (FeSfresh) and aged (FeSaged). The short- to medium-range structure of both FeSfresh and FeSaged are nearly identical with that of highly crystalline (bulk) mackinawite. Attenuation in the observed range of structural coherence of the PDF for FeSfresh indicates an average crystallite size on the order of similar to 2 nm. This range of structural coherence increased with aging of the sample under hydrothermal conditions due to growth of the individual crystallites, although the mechanism by which this growth occurs is not clear at present. Electron microscopic imaging confirms the presence of individual nanoscale crystallites and provides some insight into their aggregation behavior as larger clusters. The initial, fresh precipitate does not exhibit long-range atomic structure because it is nanocrystalline. The so-called X-ray amorphous nature of FeSfresh is the result of the limited range of structural coherence imposed by the size of the individual crystallites rather than the result of a lack of medium- and long-range atomic order. We propose that the discrepancies in the literature over crystallite size and the atomic structure of FeSfresh are due primarily to the varying degrees of aggregation of uniformly distributed and nanocrystalline FeS particles. C1 SUNY Stony Brook, CEMS, Dept Geosci, Stony Brook, NY 11794 USA. Argonne Natl Lab, XOR, Adv Photon Source, Argonne, IL 60439 USA. RP SUNY Stony Brook, CEMS, Dept Geosci, Stony Brook, NY 11794 USA. EM fmichel@ic.sunysb.edu RI Schoonen, martin/E-7703-2011 OI Schoonen, martin/0000-0002-7133-1160 NR 52 TC 52 Z9 52 U1 2 U2 31 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD DEC 13 PY 2005 VL 17 IS 25 BP 6246 EP 6255 DI 10.1021/cm050886b PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 991WU UT WOS:000233846100008 ER PT J AU Sinks, LE Rybtchinski, B Iimura, M Jones, BA Goshe, AJ Zuo, XB Tiede, DM Li, XY Wasielewski, MR AF Sinks, LE Rybtchinski, B Iimura, M Jones, BA Goshe, AJ Zuo, XB Tiede, DM Li, XY Wasielewski, MR TI Self-assembly of photofunctional cylindrical nanostructures based on perylene-3,4 : 9,10-bis(dicarboximide) SO CHEMISTRY OF MATERIALS LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; LIGHT-HARVESTING COMPLEX; SMALL-ANGLE-SCATTERING; CRYSTALLINE PERYLENE DIIMIDE; BISIMIDE-MELAMINE ASSEMBLIES; CHARGE SEPARATION; BUILDING-BLOCKS; LIQUID-CRYSTALS; SUPRAMOLECULAR ARCHITECTURES; RHODOPSEUDOMONAS-ACIDOPHILA AB A perylene-3,4:9, 10-bis(dicarboximide)-based electron donor-acceptor monomer was designed to self-assemble using the synergistic effects of pi-pi stacking, microsegregation, and hydrogen bonding. The resulting aggregates were characterized in solution by small-angle X-ray scattering (SAXS), while the solid-state structure was probed by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The solution-phase assemblies were found to consist of 12 monomers arranged in either a face-to-face stacked pair of hydrogen-bonded hexagonal arrays or a two-turn helix. The SAXS data do not allow a clear distinction between these two cyclic motifs. These cyclic arrays grow to lengths of about I urn and form bundles of cylindrical structures in the solid phase. Aggregation is solvent dependent, with methylcyclohexane inducing aggregation and tetrahydrofuran disrupting it. The solution-phase photophysics of the dodecamer were probed by UV-vis, time-resolved fluorescence, and fenitosecond transient absorption spectroscopies, revealing that formation of the dodecamer introduces an ultrafast electron-transfer pathway that is not present in the monomer. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Ctr Nanofabricat & Mol Self Assembly, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Li, XY (reprint author), Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. EM wasielew@chem.northwestern.edu RI Zuo, Xiaobing/F-1469-2010 NR 53 TC 83 Z9 83 U1 4 U2 34 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 DEC 13 PY 2005 VL 17 IS 25 BP 6295 EP 6303 DI 10.1021/cm051461s PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 991WU UT WOS:000233846100013 ER PT J AU Pyda, M Wunderlich, B AF Pyda, M Wunderlich, B TI Reversing and nonreversing heat capacity of poly(lactic acid) in the glass transition region by TMDSC SO MACROMOLECULES LA English DT Article ID DIFFERENTIAL SCANNING CALORIMETRY; CRYSTALLIZATION; POLYSTYRENE; COPOLYMERS; POLYMERS; MACROMOLECULES; BEHAVIOR; KINETICS; WATER AB A study of the glass transition of an amorphous and a semicrystalline poly(lactic acid) (PLA) is performed with adiabatic calorimetry, differential scanning calorimetry (DSC), and temperature-modulated DSC (TMDSC). The reversing, total, and nonreversing apparent heat capacities of samples with different contents of L- and D-lactic acid and with various thermal histories were evaluated. Different modes of TMDSC analyses of amorphous and semicrystalline PLA were compared to the total heat capacity from standard DSC. The enthalpy relaxation and the cold crystallization in the glass transition region are largely irreversible. The melting is largely irreversible, but a 100% reversing fraction is observed at low temperatures from 375 to 420 K, which becomes small inside the major melting peak at about 440 K. From the TMDSC of amorphous PLA, the combined information on endothermic and exothermic enthalpy relaxation and glass transition were deconvoluted into the reversing and nonreversing components. The glass transition temperature from the reversing heat capacity and the enthalpy relaxation peaks from the nonreversing component shift to higher temperature for increasingly annealed PLA. The relaxation times for aging decrease on cooling until the glass transition is reached and then increase. This behavior is linked to cooperativity. All quantitative thermal analyses are based on the heat capacity of the solid and liquid, evaluated earlier with the advanced thermal analysis system (ATHAS). C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Univ Technol, Dept Chem, PL-35959 Rzeszow, Poland. RP Pyda, M (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM mpyda@utk.edu NR 43 TC 42 Z9 42 U1 4 U2 39 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 13 PY 2005 VL 38 IS 25 BP 10472 EP 10479 DI 10.1021/ma051611k PG 8 WC Polymer Science SC Polymer Science GA 992EC UT WOS:000233866200018 ER PT J AU Qian, XH Ding, SY Nimlos, MR Johnson, DK Himmel, ME AF Qian, XH Ding, SY Nimlos, MR Johnson, DK Himmel, ME TI Atomic and electronic structures of molecular crystalline cellulose I beta: A first-principles investigation SO MACROMOLECULES LA English DT Article ID NEUTRON FIBER DIFFRACTION; SYNCHROTRON X-RAY; HYDROGEN-BONDING SYSTEM; C-13 NMR-SPECTRUM; NATIVE CELLULOSE; HIGH-TEMPERATURES; COMPLETE ASSIGNMENT; VALONIA CELLULOSE; PICEA-ABIES; TRANSFORMATION AB A theoretical model based on the competition between hydrogen-bonding energy and strain energy was constructed to explain the size of native cellulose I beta. The cellodextrins in native crystalline cellulose I alpha and I beta are unusually stable compared to other polysaccharides, not easily prone to hydrolysis even though they are only nanometers in diameter. The stability of crystalline cellulose I beta is most likely due to its greatly enhanced hydrogen-bonding (1113) network. We carried out ab initio calculations to determine the native crystalline cellulose I beta atomic and conformational. structures. For crystalline cellulose, we found that every hydroxyl group in the cellulose structure is hydrogen bonded as both a donor and an acceptor. This agrees well with published X-ray and neutron diffraction data. We also determined the electronic structures and the energetics for one cellodextrin chain, one to four sheets of cellodextrins in cellulose, and the bulk cellulose I beta. C1 Rx Innovat Inc, Ft Collins, CO 80525 USA. Natl Renewable Energy Lab, Natl Bioenergy Ctr, Golden, CO 80401 USA. RP Qian, XH (reprint author), Rx Innovat Inc, Ft Collins, CO 80525 USA. RI Johnson, David/G-4959-2011; Ding, Shi-You/O-1209-2013; Qian, Xianghong/C-4821-2014 OI Johnson, David/0000-0003-4815-8782; NR 38 TC 34 Z9 37 U1 2 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD DEC 13 PY 2005 VL 38 IS 25 BP 10580 EP 10589 DI 10.1021/ma051683b PG 10 WC Polymer Science SC Polymer Science GA 992EC UT WOS:000233866200034 ER PT J AU Speziale, S Milner, A Lee, VE Clark, SM Pasternak, MP Jeanloz, R AF Speziale, S Milner, A Lee, VE Clark, SM Pasternak, MP Jeanloz, R TI Iron spin transition in Earth's mantle SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE lower mantle; Mossbauer; magnesiowustite ID HIGH-PRESSURES; MOSSBAUER-SPECTROSCOPY; MEGABAR PRESSURES; MAGNESIOWUSTITE; PEROVSKITE; TEMPERATURE; MAGNETISM; STATE; FERROPERICLASE; DEPENDENCE AB High-pressure Mossbauer spectroscopy on several compositions across the (Mg,Fe)O magnesiowUstite solid solution confirms that ferrous iron (Fe2+) undergoes a high-spin to low-spin transition at pressures and for compositions relevant to the bulk of the Earth's mantle. High-resolution x-ray diffraction measurements document a volume change of 4-5% across the pressure-induced spin transition, which is thus expected to cause seismological anomalies in the lower mantle. The spin transition can lead to dissociation of Fe-bearing phases such as magnesiowustite, and it reveals an unexpected richness in mineral properties and phase equilibria for the Earth's deep interior. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Jeanloz, R (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, 307 McCone Hall, Berkeley, CA 94720 USA. EM jeanloz@berkeley.edu RI Clark, Simon/B-2041-2013 OI Clark, Simon/0000-0002-7488-3438 NR 29 TC 123 Z9 124 U1 1 U2 26 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 DEC 13 PY 2005 VL 102 IS 50 BP 17918 EP 17922 DI 10.1073/pnas.0508919102 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 994DL UT WOS:000234010500009 PM 16330758 ER PT J AU Norby, RJ DeLucia, EH Gielen, B Calfapietra, C Giardina, CP King, JS Ledford, J McCarthy, HR Moore, DJP Ceulemans, R De Angelis, P Finzi, AC Karnosky, DF Kubiske, ME Lukac, M Pregitzer, KS Scarascia-Mugnozza, GE Schlesinger, WH Oren, R AF Norby, RJ DeLucia, EH Gielen, B Calfapietra, C Giardina, CP King, JS Ledford, J McCarthy, HR Moore, DJP Ceulemans, R De Angelis, P Finzi, AC Karnosky, DF Kubiske, ME Lukac, M Pregitzer, KS Scarascia-Mugnozza, GE Schlesinger, WH Oren, R TI Forest response to elevated CO2 is conserved across a broad range of productivity SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE CO2 fertilization; global change; leaf area index; net primary productivity ID ATMOSPHERIC CARBON-DIOXIDE; FUTURE CLIMATE-CHANGE; FINE-ROOT PRODUCTION; DECIDUOUS FOREST; POPLAR PLANTATION; LITTER PRODUCTION; TROPOSPHERIC O-3; FACE EXPERIMENTS; TREMBLING ASPEN; ENRICHMENT FACE AB Climate change predictions derived from coupled carbon-climate models are highly dependent on assumptions about feedbacks between the biosphere and atmosphere. One critical feedback occurs if C uptake by the biosphere increases in response to the fossil-fuel driven increase in atmospheric [CO2] ("CO2 fertilization"), thereby slowing the rate of increase in atmospheric [CO2]. Carbon exchanges between the terrestrial biosphere and atmosphere are often first represented in models as net primary productivity (NPP). However, the contribution of CO2 fertilization to the future global C cycle has been uncertain, especially in forest ecosystems that dominate global NPP, and models that include a feedback between terrestrial blosphere metabolism and atmospheric [CO2] are poorly constrained by experimental evidence. We analyzed the response of NPP to elevated CO2 (approximate to 550 ppm) in four free-air CO2 enrichment experiments in forest stands. We show that the response of forest NPP to elevated [CO2] is highly conserved across a broad range of productivity, with a stimulation at the median of 23 +/- 2%. At low leaf area indices, a large portion of the response was attributable to increased light absorption, but as leaf area indices increased, the response to elevated [CO2] was wholly caused by increased light-use efficiency. The surprising consistency of response across diverse sites provides a benchmark to evaluate predictions of ecosystem and global models and allows us now to focus on unresolved questions about carbon partitioning and retention, and spatial variation in NPP response caused by availability of other growth limiting resources. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Illinois, Dept Plant Biol, Urbana, IL 61801 USA. Univ Illinois, Program EvolutIonary Biol & Ecol, Urbana, IL 61801 USA. Univ Instelling Antwerp, Dept Biol, B-2610 Antwerp, Belgium. Univ Tuscia, Dept Forest Environm & Resources, I-01100 Viterbo, Italy. USDA, Forest Serv, N Cent Res Stn, Houghton, MI 49931 USA. N Carolina State Univ, Dept Forestry & Environm Resources, Raleigh, NC 27695 USA. Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC 27708 USA. Boston Univ, Dept Biol, Boston, MA 02215 USA. Michigan Technol Univ, Ecosyst Sci Ctr, Sch Forest Resources & Environm Sci, Houghton, MI 49931 USA. USDA, Forest Serv, N Cent Res Stn, Rhinelander, WI 54501 USA. Univ Wales, Sch Agr & Forest Sci, Bangor LL57 2UW, Gwynedd, Wales. CNR, Inst Agroenvironm & Forest Biol, I-05010 Porano, TR, Italy. RP Norby, RJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM rjn@ornl.gov; schiesin@duke.edu RI Giardina, Christian/C-3120-2011; De Angelis, Paolo/A-6863-2012; Norby, Richard/C-1773-2012; Lukac, Martin/A-4379-2013; Moore, David/A-6268-2013; Calfapietra, Carlo/E-2269-2015; Finzi, Adrien/A-7017-2016; Ceulemans, Reinhart/F-2109-2016; OI Giardina, Christian/0000-0002-3431-5073; De Angelis, Paolo/0000-0001-8310-8831; Norby, Richard/0000-0002-0238-9828; Lukac, Martin/0000-0002-8535-6334; Finzi, Adrien/0000-0003-2220-4533; McCarthy, Heather R/0000-0002-2219-5182 NR 43 TC 508 Z9 527 U1 12 U2 246 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 DEC 13 PY 2005 VL 102 IS 50 BP 18052 EP 18056 DI 10.1073/pnas.0509478102 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 994DL UT WOS:000234010500032 PM 16330779 ER PT J AU Antony, J Chen, XB Morrison, J Bergman, L Qiang, Y McCready, DE Engelhard, MH AF Antony, J Chen, XB Morrison, J Bergman, L Qiang, Y McCready, DE Engelhard, MH TI ZnO nanoclusters: Synthesis and photoluminescence SO APPLIED PHYSICS LETTERS LA English DT Article ID ZINC-OXIDE; QUANTUM DOTS; OPTICAL-PROPERTIES; OXYGEN VACANCIES; FILMS; NANOPARTICLES; POWDERS AB ZnO nanoclusters were prepared and deposited at room temperature using a newly developed cluster source. The nanoclusters act as a building block for the cluster films deposited on various substrates. The cluster films were characterized by transmission electron microscopy, x-ray photoelectron spectroscopy, x-ray diffraction, and photoluminescence. We prepared monodispersed crystalline ZnO nanoclusters of similar to 7 nm diameter. These clusters have a significant blueshift of similar to 125 meV (compared to the results published so far) within the ultraviolet region at room temperature. No PL in our samples was observed in the visible region, which implies negligible defect formation in ZnO nanocluster films. (c) 2005 American Institute of Physics. C1 Univ Idaho, Dept Phys, Moscow, ID 83844 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Univ Idaho, Dept Phys, Moscow, ID 83844 USA. EM youqiang@uidaho.edu RI Engelhard, Mark/F-1317-2010; Chen, Xiang-Bai/B-7052-2012; OI Engelhard, Mark/0000-0002-5543-0812 NR 27 TC 38 Z9 38 U1 1 U2 14 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 DEC 12 PY 2005 VL 87 IS 24 AR 241917 DI 10.1063/1.2147715 PG 3 WC Physics, Applied SC Physics GA 991PM UT WOS:000233825900047 ER PT J AU Dhar, S Rao, MSR Ogale, SB Kundaliya, DC Shinde, SR Venkatesan, T Welz, SJ Erni, R Browning, ND AF Dhar, S Rao, MSR Ogale, SB Kundaliya, DC Shinde, SR Venkatesan, T Welz, SJ Erni, R Browning, ND TI Growth of highly oriented HfO2 thin films of monoclinic phase on yttrium-stabilized ZrO2 and Si substrates by pulsed-laser deposition SO APPLIED PHYSICS LETTERS LA English DT Article ID TEMPERATURE FERROMAGNETISM; THERMAL-STABILITY AB We report on the growth of highly oriented HfO2 thin films of monoclinic phase stabilized by 5% Co doping on (001) yttrium-stabilized zirconia (YSZ) using pulsed-laser deposition at 700 degrees C at an oxygen partial pressure of 10(-4) Torr. On the other hand, pure HfO2 of such quality did not grow on YSZ in wide range of growth parameters. Rutherford backscattering-ion channeling in this film showed a 24% minimum yield (chi(min)) indicating highly oriented film growth, while hardly any ion channeling was observed in the undoped sample. High-resolution transmission electron microscopy revealed a sharp interface, and no signature of Co clusters. Electron energy loss spectroscopy showed that Co is in the 2+ state. Attempts were also made to grow films on a (001) Si substrate, and the results showed a very low ion channeling yield (similar to 8%). (c) 2005 American Institute of Physics. C1 Univ Maryland, Ctr Superconduct Res, Dept Phys, College Pk, MD 20742 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Lawrence Berkeley Natl Lab, NCEM, Berkeley, CA 94720 USA. RP Univ Maryland, Ctr Superconduct Res, Dept Phys, College Pk, MD 20742 USA. EM dhar@squid.umd.edu RI Venkatesan, Thirumalai/E-1667-2013; Erni, Rolf/P-7435-2014; OI Erni, Rolf/0000-0003-2391-5943; Browning, Nigel/0000-0003-0491-251X NR 21 TC 6 Z9 8 U1 0 U2 10 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 DEC 12 PY 2005 VL 87 IS 24 AR 241504 DI 10.1063/1.2142088 PG 3 WC Physics, Applied SC Physics GA 991PM UT WOS:000233825900028 ER PT J AU Graf, PA Kim, K Jones, WB Hart, GLW AF Graf, PA Kim, K Jones, WB Hart, GLW TI Direct enumeration of alloy configurations for electronic structural properties SO APPLIED PHYSICS LETTERS LA English DT Article ID DOT P METHOD; SEMICONDUCTOR ALLOYS; COMPOSITION MODULATION; BAND-GAPS; SUPERLATTICES; SYSTEMS AB We present and apply an approach to directly enumerate the band gaps and effective masses of all possible zinc blende-based alloy configurations whose unit cell contains up to a specified number of atoms. This method allows us to map the space of band gaps and effective masses versus alloy composition and atomic configuration. We demonstrate that a large number of band gaps and effective masses are available. We also discuss convergence of the method with respect to unit cell size and the combined optimization of band gap and effective mass for AlGaAs and GaInP semiconductor alloys. (c) 2005 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. No Arizona Univ, Dept Phys, Flagstaff, AZ 86011 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. EM kwiseon_kim@nrel.gov OI Hart, Gus L. W./0000-0002-6149-9234 NR 27 TC 11 Z9 11 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 DEC 12 PY 2005 VL 87 IS 24 AR 243111 DI 10.1063/1.2142091 PG 3 WC Physics, Applied SC Physics GA 991PM UT WOS:000233825900087 ER PT J AU Iavarone, M Karapetrov, G Menzel, A Komanicky, V You, H Kwok, WK Orgiani, P Ferrando, V Xi, XX AF Iavarone, M Karapetrov, G Menzel, A Komanicky, V You, H Kwok, WK Orgiani, P Ferrando, V Xi, XX TI Characterization of off-axis MgB2 epitaxial thin films for planar junctions SO APPLIED PHYSICS LETTERS LA English DT Article ID JOSEPHSON-JUNCTIONS; MAGNESIUM-DIBORIDE; SUPERCONDUCTIVITY AB Using scanning tunneling spectroscopy, we perform a full mapping of the quasiparticle density of states of magnesium diboride (MgB2) epitaxial thin films grown on (110) yttrium stabilized zirconia (YSZ) by hybrid physical-chemical vapor deposition. The films have critical temperatures of 40 K. X-ray measurements show an epitaxial MgB2 growth having the c-axis tilted by 32 degrees with respect to the normal to the substrate, consistent with the atomic force microscopy images of the sample. Scanning tunneling spectroscopy clearly finds that the spectroscopic peak associated to the pi gap is reduced on most of the film surface and the feature representative of the sigma gap is present, with different intensity, on the majority of the sample's surface, which is consistent with x-ray measurements. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Naples Federico II, INFM Coherentia, I-80125 Naples, Italy. Univ Genoa, INFM, LAMIA, I-16146 Genoa, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM maria@anl.gov RI Iavarone, Maria/C-3628-2008; Orgiani, Pasquale/E-7146-2013; You, Hoydoo/A-6201-2011; Karapetrov, Goran/C-2840-2008; Menzel, Andreas/C-4388-2012 OI Orgiani, Pasquale/0000-0002-1082-9651; You, Hoydoo/0000-0003-2996-9483; Karapetrov, Goran/0000-0003-1113-0137; Menzel, Andreas/0000-0002-0489-609X NR 13 TC 12 Z9 13 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 12 PY 2005 VL 87 IS 24 AR 242506 DI 10.1063/1.2140473 PG 3 WC Physics, Applied SC Physics GA 991PM UT WOS:000233825900065 ER PT J AU Li, ZY Yuan, J Chen, Y Palmer, RE Wilcoxon, JP AF Li, ZY Yuan, J Chen, Y Palmer, RE Wilcoxon, JP TI Direct imaging of core-shell structure in silver-gold bimetallic nanoparticles SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICAL-PROPERTIES; AU NANOPARTICLES; CLUSTERS; COLLOIDS; ABSORPTION; CONTRAST; GROWTH AB High-angle annular dark field imaging in the electron microscope has been exploited to reveal the internal structure of monodispersed, bimetallic gold (Au) - silver (Ag) nanoparticles of similar to 4 nm diameter, prepared using a seed-growth wet chemical method and passivated with an organic layer. Starting with a 3 nm Ag seed particle, deposition of Au atoms to a final overall atomic ratio of Ag:Au=1:2 leads to nanoparticles with an Ag-rich core and an Au-rich shell, as expected. If the overall atomic ratio is 2:1, the core/shell structure is not observed. The physical significance of these observations is discussed in terms of the stability of particles of nanoscale dimensions. (c) 2005 American Institute of Physics. C1 Univ Birmingham, Sch Phys & Astron, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. Tsing Hua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. Sandia Natl Labs, Adv Mat Sci Dept 1122, Albuquerque, NM 87185 USA. RP Li, ZY (reprint author), Univ Birmingham, Sch Phys & Astron, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. EM ziyouli@nprl.ph.bham.ac.uk; yuanjun@tsinghua.edu.cn RI Palmer, Richard/A-5366-2008; Yuan, Jun/J-2577-2012; Chen, Yu/B-8858-2013 OI Palmer, Richard/0000-0001-8728-8083; Yuan, Jun/0000-0001-5833-4570; NR 26 TC 38 Z9 38 U1 2 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 DEC 12 PY 2005 VL 87 IS 24 AR 243103 DI 10.1063/1.2139851 PG 3 WC Physics, Applied SC Physics GA 991PM UT WOS:000233825900079 ER PT J AU Naito, M Ishimaru, M Hirotsu, Y Valdez, JA Sickafus, KE AF Naito, M Ishimaru, M Hirotsu, Y Valdez, JA Sickafus, KE TI Transmission electron microscopy study on ion-beam-synthesized amorphous Fe-Si thin layers SO APPLIED PHYSICS LETTERS LA English DT Article ID IRON DISILICIDE; DIFFRACTION; FILMS; SI(111); FESI2 AB Ion-beam-synthesized amorphous Fe-Si thin layers have been characterized using transmission electron microscopy (TEM) in combination with imaging plate techniques. Si single crystals with a (111) orientation were irradiated with 120 keV Fe+ ions to a fluence of 4.0 x 10(17) cm(-2) at cryogenic temperature (120 K). Cross- sectional TEM observations indicated the formation of an amorphous bilayer on the topmost layer of the Si substrate. It was found that the upper layer is an amorphous Fe-Si with the composition, in terms of atomic ratio, of Fe/ Si similar to 1/2, while the lower one is an amorphous Si. Atomic pair-distribution functions extracted from microbeam electron diffraction patterns revealed that the nature of short-range order in amorphous Fe-Si thin layer can be well described by the atomic arrangements of crystalline iron silicides. (c) 2005 American Institute of Physics. C1 Osaka Univ, Inst Sci & Ind Res, Ibaraki 5670047, Japan. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Naito, M (reprint author), Osaka Univ, Inst Sci & Ind Res, Ibaraki 5670047, Japan. EM naito22@sanken.osaka-u.ac.jp NR 18 TC 15 Z9 15 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 12 PY 2005 VL 87 IS 24 AR 241905 DI 10.1063/1.2142101 PG 3 WC Physics, Applied SC Physics GA 991PM UT WOS:000233825900035 ER PT J AU Hayton, TW Boncella, JM Scott, BL Abboud, KA Mills, RC AF Hayton, TW Boncella, JM Scott, BL Abboud, KA Mills, RC TI Coupling of an aldehyde or ketone to pyridine mediated by a tungsten imido complex SO INORGANIC CHEMISTRY LA English DT Article ID ALPHA,ALPHA-DISUBSTITUTED-2,6-PYRIDINEDIMETHOXIDE LIGANDS; INSERTION REACTIONS; ALKYLIDENE COMPLEX; DIENE COMPLEXES; METAL; ALKOXIDE; W(IV) AB The reactivity of W(NPh)(o-(Me3SiN)(2)C6H4)(py)(2) and W(NPh)(o-(Me3SiN)(2)C6H4)(PiC)(2) (py = pyridine; pic = 4-picoline) with unsaturated substrates has been investigated. Treatment of W(NPh)(o-(Me3SiN)(2)C6H4)(py)(2) with diphenylacetylene or 2,3-dimethyl-1,3-butadiene generates W(NPh)(o-(Me3SiN)(2)C6H4)(n(2)-PhC&3bond; CPh) (1) and W(NPh)(o-(Me3SiN)2C6H4)(n(4-)CH(2)=C(Me)C(Me)=CH2) (3), respectively, while the addition of ethylene to W(NPh)(o-(Me3SiN)2C6H4)(py)2 generates the known metallacycle W(NPh)(o-(Me3SiN)(2)C6H4)(CH2CH2CH2CH2). The addition of 2 equiv of acetone to W(NPh)(o-(Me3SiN)2C6H4)(PiC)2 provides the azaoxymetallacycle W(NPh)(o-(Me3SiN)(2)C6H4)(OCH(Me)(2))(OC(Me)(2)-o-C5H3N-p-Me) (4), the result of acetone insertion into the ortho C-H bond of picoline. Similarily, the addition of 2 equiv of RC(O)H [R = Ph, Bu-t] to W(NPh)(o-(Me3SiN)(2)C6H4)(PY)(2) generates W(NPh)(o-(Me3SiN)(2)C6H4)(OCH2R)(OCH(R)-o-C5H4N) [R = Ph, 5; Bu-t, 6]. In contrast, reaction between W(NPh)(o-(Me3SiN)2C6H4)(PY)2 and 2-pyridine carboxaldehyde yields the diolate W(NPh)(o-(Me3SiN)2C6H4)(CCH(C5H4N)CH(C5H4N)O) (7). The synthesis of W(NPh)(o-(Me3SiN)(2)C6H4)(PMe3) (py)(n(2)-OC(H)C6H4-p-Me) (9), formed by the addition of p-tolualdehyde to a mixture of W(NPh)(o-(Me3SiN)2C6H4)(PY)2 and PMe3, Suggests that an n(2)-aldehyde intermediate is involved in the formation of the azaoxymetallacycle, while the isolation of W(NPh)(o-(Me3SiN)(2)C6H4)(Cl)(OC(Me)(CMe3)-o-C5H4N) (10), formed by the reaction of pinacolone with W(NPh)(o-(Me3SiN)2C6H4)(PY)2, in the presence of adventitious CH2CI2, suggests that the reaction proceeds via the hydride W(NPh)(o-(Me3SiN)(2)C6H4)(H)(OC(Me)(CMe3)-O-C5H4N). C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. Univ Florida, Ctr Catalysis, Gainesville, FL 32611 USA. RP Boncella, JM (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663,MS J582, Los Alamos, NM 87545 USA. EM boncella@lanl.gov RI Scott, Brian/D-8995-2017; OI Scott, Brian/0000-0003-0468-5396; Boncella, James/0000-0001-8393-392X NR 30 TC 13 Z9 13 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 DEC 12 PY 2005 VL 44 IS 25 BP 9506 EP 9517 DI 10.1021/ic0511367 PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 991FD UT WOS:000233796800052 PM 16323938 ER PT J AU Hatta, Y Iancu, E McLerran, L Stasto, A AF Hatta, Y Iancu, E McLerran, L Stasto, A TI Color dipoles from Bremsstrahlung in QCD evolution at high energy SO NUCLEAR PHYSICS A LA English DT Article ID GLUON DISTRIBUTION-FUNCTIONS; GLASS CONDENSATE; BFKL POMERON; RENORMALIZATION-GROUP; LARGE NUCLEI; N-C; SCATTERING; EQUATION; UNITARITY; REPRESENTATION AB We show that the recently developed Hamiltonian theory for high-energy evolution in QCD in the dilute regime and in the presence of Bremstrahlung is consistent with the color dipole picture in the limit where the number of colors N-c is large. The color dipoles are quark-antiquark pairs which can radiate arbitrarily many soft gluons. and the evolution consists in the splitting of any such a dipole into two. We construct the color class weight function of an oniurn as a superposition of color dipoles, each represented by a pair of Wilson lines. We show that the action of the Bremstrahlung Hamiltonian on this weight function and in the large-N-c limit generates the evolution expected from the dipole picture. We construct the dipole number operator in the Hamiltonian theory and deduce the evolution equations for the dipole densities, which are again consistent with the dipole picture. We argue that the Bremsstrahlung effects beyond two gluon emission per dipole are irrelevant for the calculation of scattering amplitudes at high energy. (c) 2005 Elsevier B.V. All rights reserved. C1 Serv Phys Theor, F-91191 Gif Sur Yvette, France. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. RP Iancu, E (reprint author), Serv Phys Theor, F-91191 Gif Sur Yvette, France. EM iancu@spht.saclay.cea.fr NR 45 TC 20 Z9 20 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 DEC 12 PY 2005 VL 762 IS 3-4 BP 272 EP 297 DI 10.1016/j.nuclphysa.2005.08.008 PG 26 WC Physics, Nuclear SC Physics GA 987GU UT WOS:000233507200005 ER PT J AU Alam, TM Otaigbe, JU Rhoades, D Holland, GP Cherry, BR Kotula, PG AF Alam, TM Otaigbe, JU Rhoades, D Holland, GP Cherry, BR Kotula, PG TI Nanostructured polymer blends: Synthesis and structure SO POLYMER LA English DT Article DE nanostructured polymer blends; morphology and dynamics; in situ polymerization ID SOLID-STATE NMR; CARBONATE CYCLIC OLIGOMERS; IN-SITU POLYMERIZATION; ISOTACTIC POLYPROPYLENE; COPOLYMER; DYNAMICS; MISCIBILITY; COMPOSITES AB Nanostructured polymer blends prepared via anionic ring opening polymerizations of cyclic monomers in the presence of a pre-made polymer melt exhibit a number of special properties over traditional polymer blends and homopolymers. Here, we report on a simple and versatile method of in situ polymerization of macrocyclic carbonates in the presence of a maleic anhydride polypropylene (mPP) matrix and a surface-active compatibilizer (i.e. PC grafted onto a mPP backbone generated in situ) to yield a micro- and nanostructured polymer blends consisting of a polycarbonate (PC) minor phase, and a polypropylene (PP) major phase. By varying the processing conditions and concentration of the macrocyclic carbonate it was possible to reduce the size of the PC dispersions to an average minor diameter of 150 nm. NMR and TEM characterizations indicate that the PC dispersions do not influence crystal content in the PP phase. Overall, the results point to a simple strategy and versatile route to new polymeric materials with enhanced benefits. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ So Mississippi, Sch Polymers & High Performance Mat, Hattiesburg, MS 39406 USA. Sandia Natl Labs, Dept Elect & Nanostruct Mat, Albuquerque, NM 87185 USA. RP Otaigbe, JU (reprint author), Univ So Mississippi, Sch Polymers & High Performance Mat, 118 Coll Dr,10076, Hattiesburg, MS 39406 USA. EM joshua.otaigbe@usm.edu RI Kotula, Paul/A-7657-2011 OI Kotula, Paul/0000-0002-7521-2759 NR 54 TC 8 Z9 8 U1 3 U2 11 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD DEC 12 PY 2005 VL 46 IS 26 BP 12468 EP 12479 DI 10.1016/j.polymer.2005.10.079 PG 12 WC Polymer Science SC Polymer Science GA 998WK UT WOS:000234350400050 ER PT J AU Hoekstra, H Hsieh, BC Yee, HKC Lin, H Gladders, MD AF Hoekstra, H Hsieh, BC Yee, HKC Lin, H Gladders, MD TI Virial masses and the baryon fraction in galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dark matter; galaxies : halos; gravitational lensing ID SEQUENCE CLUSTER SURVEY; DIGITAL SKY SURVEY; HUBBLE-DEEP-FIELD; DARK-MATTER HALOS; TULLY-FISHER RELATION; TO-LIGHT RATIOS; DENSITY PROFILES; REDSHIFT SURVEY; STELLAR MASS; EVOLUTION AB We have measured the weak-lensing signal as a function of rest-frame B-, V-, and R-band luminosity for a sample of "isolated'' galaxies. These results are based on four-band photometry from the Red-Sequence Cluster Survey, enabling us to determine photometric redshifts for a large number of galaxies. We select a secure sample of lenses with photometric redshifts 0: 2 < z < 0: 4 and study the relation between the virial mass and baryonic contents. In addition, we discuss the implications of the derived photometric redshift distribution for published cosmic shear studies. The virial masses are derived from a fit to the observed lensing signal. For a galaxy with a fiducial luminosity of 10(10) h(-2) L(B,)circle dot, we obtain a mass M-vir = 9.9(-1.3)(+1.5) x 10(11) M circle dot The virial mass as a function of luminosity is consistent with a power law proportional to L-1.5, with similar slopes for the three filters considered here. These findings are in excellent agreement with results from the Sloan Digital Sky Survey and semianalytic models of galaxy formation. We measure the fraction of mass in stars and the baryon fraction in galaxies by comparing the virial mass-to-light ratio to predicted stellar mass-to-light ratios. We find that star formation is inefficient in converting baryons into stars, with late-type galaxies converting similar to 33% and early-type galaxies converting only similar to 14% of baryons into stars. Our results imply that the progenitors of early-type galaxies must have low stellar mass fractions, suggestive of a high formation redshift. C1 Univ Victoria, Dept Phys & Astron, Victoria, BC V8P 5C2, Canada. Univ Toronto, Canadian Inst Theoret Phys, Toronto, ON M5S 3H8, Canada. Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H8, Canada. Natl Cent Univ, Inst Astron, Jhongli City 320, Taiwan. Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Observ Carnegie, Pasadena, CA 91101 USA. RP Hoekstra, H (reprint author), Univ Victoria, Dept Phys & Astron, POB 3055, Victoria, BC V8P 5C2, Canada. OI Hoekstra, Henk/0000-0002-0641-3231 NR 58 TC 105 Z9 105 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 DEC 10 PY 2005 VL 635 IS 1 BP 73 EP 85 DI 10.1086/496913 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 993CF UT WOS:000233929600006 ER PT J AU Rockefeller, G Fryer, CL Melia, F AF Rockefeller, G Fryer, CL Melia, F TI Spin-induced disk precession in Sagittarius A SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; Galaxy : center; radiation mechanisms : nonthermal; radiation mechanisms : thermal; relativity ID WEAKLY MAGNETIZED DISKS; LOCAL SHEAR INSTABILITY; BLACK-HOLE; GALACTIC-CENTER; HYDRODYNAMIC SIMULATIONS; ASTERISK; ACCRETION; EMISSION AB In Sgr A* at the Galactic center, by far the closest and easiest supermassive black hole we can study, the observational evidence is increasingly pointing to the presence of a compact, hot, magnetized disk feeding the accretor. In such low Mach number plasmas, forces arising, e. g., from pressure gradients in the plasma, can altogether negate the warping of disks around Kerr black holes caused by the Bardeen-Petterson effect and can lead to coherent precession of the entire disk. In this paper, we present for the first time highly detailed three-dimensional smoothed particle hydrodynamics (SPH) simulations of the accretion disk evolution in Sgr A*, guided by observational constraints on its physical characteristics, and conclude that indeed the Bardeen-Petterson effect is probably absent in this source. Given what we now understand regarding the emission geometry in this object, we suggest that a similar to 50-500 days modulation in Sgr A*'s spectrum, arising from the disk precession, could be an important observational signature; perhaps the similar to 106 days period seen earlier in its radio flux, if confirmed, could be due to this process. On the other hand, if future observations do not confirm this long modulation in Sgr A*'s spectrum, this would be an indication either that the disk size or orientation is very different from current estimates, that the black hole is not spinning at all ( unlikely), or that our current understanding of how it produces its radiative output is incorrect. C1 Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Rockefeller, G (reprint author), Univ Arizona, Dept Phys, 1118 E 4th St,POB 210081, Tucson, AZ 85721 USA. RI Rockefeller, Gabriel/G-2920-2010 OI Rockefeller, Gabriel/0000-0002-9029-5097 NR 21 TC 6 Z9 6 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2005 VL 635 IS 1 BP 336 EP 340 DI 10.1086/496947 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 993CF UT WOS:000233929600025 ER PT J AU Hungerford, AL Fryer, CL Rockefeller, G AF Hungerford, AL Fryer, CL Rockefeller, G TI Gamma rays from single-lobe supernova explosions SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : theory; stars : neutron; supernovae : general ID CORE-COLLAPSE SUPERNOVAE; SPECTRAL-LINE PROFILES; MASSIVE STARS; 3 DIMENSIONS; SN-1987A; 1987A; HYDRODYNAMICS; VELOCITY; KICKS; SPECTROPOLARIMETRY AB Multidimensional simulations of the neutrino-driven mechanism behind core-collapse supernovae have long shown that the explosions from this mechanism would be asymmetric. Recently, detailed core-collapse simulations have shown that the explosion may be strongest in a single direction. We present a suite of simulations modeling these "single-lobe'' supernova explosions of a 15 M circle dot red supergiant star, focusing on the effect these asymmetries have on the gamma-ray emission and the mixing in the explosion. We discuss how these asymmetries in the explosion mechanism might explain many of the observed "asymmetries'' of supernovae, focusing on features of both supernova 1987A and the Cassiopeia A supernova remnant. In particular, we show that single-lobe explosions provide a promising solution to the redshifted iron lines of supernova 1987A. We also show that the extent of mixing for explosive burning products depends sensitively on the angular profile of the velocity asymmetry and may be much more extensive than previously assumed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Theoret Astrophys, Los Alamos, NM 87545 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM aimee@lanl.gov; fryer@lanl.gov; gaber@lanl.gov RI Rockefeller, Gabriel/G-2920-2010 OI Rockefeller, Gabriel/0000-0002-9029-5097 NR 39 TC 26 Z9 26 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2005 VL 635 IS 1 BP 487 EP 501 DI 10.1086/497323 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 993CF UT WOS:000233929600039 ER PT J AU Anninos, P Fragile, PC Salmonson, JD AF Anninos, P Fragile, PC Salmonson, JD TI COSMOS++: Relativistic magnetohydrodynamics on unstructured grids with local adaptive refinement SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; methods : numerical; MHD; relativity ID BLACK-HOLE ACCRETION; ARTIFICIAL VISCOSITY; MESH REFINEMENT; FLUID-DYNAMICS; SIMULATIONS; HYDRODYNAMICS; EQUATIONS; SCHEMES; CODE; RADIATION AB A new code and methodology are introduced for solving the general relativistic magnetohydrodynamic (GRMHD) equations in fixed background spacetimes using time-explicit, finite-volume discretization. The code has options for solving the GRMHD equations using traditional artificial viscosity (AV) or nonoscillatory central difference (NOCD) methods, or a new extended AV (eAV) scheme using artificial viscosity together with a dual energy/flux-conserving formulation. The dual-energy approach allows for accurate modeling of highly relativistic flows at boost factors well beyond what has been achieved to date by standard artificial viscosity methods. It provides the benefit of Godunov methods in capturing high Lorentz boosted flows, but without complicated Riemann solvers, and the advantages of traditional artificial viscosity methods in their speed and flexibility. In addition, the GRMHD equations are solved on an unstructured grid that supports local adaptive mesh refinement using a fully threaded oct-tree (in three dimensions) network to traverse the grid hierarchy across levels and immediate neighbors. A number of tests are presented to demonstrate robustness of the numerical algorithms and adaptive mesh framework over a wide spectrum of problems, boosts, and astrophysical applications, including relativistic shock tubes, shock collisions, magnetosonic shocks, Alfven wave propagation, blast waves, magnetized Bondi flow, and the magnetorotational instability in Kerr black hole spacetimes. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Anninos, P (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. EM fragile@physics.ucsb.edu NR 31 TC 73 Z9 73 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2005 VL 635 IS 1 BP 723 EP 740 DI 10.1086/497294 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 993CF UT WOS:000233929600061 ER PT J AU Wang, LF AF Wang, LF TI Dust around type Ia supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE distance scale; dust, extinction; supernovae : general ID HUBBLE-SPACE-TELESCOPE; INFRARED PHOTOMETRY; CIRCUMSTELLAR MEDIUM; PLANETARY-NEBULAE; LIGHT ECHOES; SN 1994D; EXTINCTION; SN-1987A; 2000CX; EJECTA AB An explanation is given of the low value of R-lambda equivalent to A(lambda)/E(B-V) the ratio of absolute to selective extinction deduced from Type Ia supernova observations. The idea involves scattering by dust clouds located in the circumstellar environment or at the highest velocity shells of the supernova ejecta. The scattered light tends to reduce the effective in the optical but has an opposite effect in the ultraviolet. The presence of circumstellar dust can be tested by R-lambda ultraviolet to near-infrared observations and by multiepoch spectropolarimetry of Type Ia supernovae. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94712 USA. Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China. RP Wang, LF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94712 USA. NR 40 TC 78 Z9 80 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 DEC 10 PY 2005 VL 635 IS 1 BP L33 EP L36 DI 10.1086/499053 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 993CG UT WOS:000233929700009 ER PT J AU Malard, JM Heredia-Langner, A Cannon, WR Mooney, R Baxter, DJ AF Malard, JM Heredia-Langner, A Cannon, WR Mooney, R Baxter, DJ TI Peptide identification via constrained multi-objective optimization: Pareto-based genetic algorithms SO CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE LA English DT Article; Proceedings Paper CT 3rd IEEE International Workshop on High Performance Computational Biology (HiCOMB 2004) CY 2004 CL Santa Fe, NM SP IEEE DE data-intensive computation; genetic algorithms; multiobjective optimization; peptide identification; tandem mass spectrometry ID TANDEM MASS-SPECTROMETRY; PROTEIN IDENTIFICATION; SEQUENCE DATABASES; SPECTRAL DATA; INFORMATION AB Automatic peptide identification from collision-induced dissociation tandem mass spectrometry data using optimization techniques is made difficult by large plateaus in the fitness landscapes of scoring functions, by the fuzzy nature of constraints from noisy data and by the existence of diverse but equally justifiable probabilistic models of peak matching. Here, two different scoring functions are combined into a parallel multi-objective optimization framework. It is shown how multi-objective optimization can be used to empirically test for independence between distinct scoring functions. The loss of selection pressure during the evolution of a population of putative peptide sequences by a Pareto-driven genetic algorithm is addressed by alternating between two definitions of fitness according to a numerical threshold. Copyright (c) 2005 John Wiley & Sons, Ltd. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Malard, JM (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM jm.malard@pnl.gov RI Cannon, William/K-8411-2014 OI Cannon, William/0000-0003-3789-7889 NR 30 TC 0 Z9 0 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1532-0626 J9 CONCURR COMP-PRACT E JI Concurr. Comput.-Pract. Exp. PD DEC 10 PY 2005 VL 17 IS 14 SI SI BP 1687 EP 1704 DI 10.1002/cpe.953 PG 18 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 981WQ UT WOS:000233119100006 ER PT J AU Mocioiu, I AF Mocioiu, I TI Very high energy neutrinos SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Review DE neutrinos astrophysics ID GAMMA-RAY BURSTS; AIR-SHOWERS; FLUX; AUGER; OSCILLATIONS; TELESCOPE; ASTRONOMY; PHYSICS; NUCLEI; LIMITS AB We discuss possible signals for very high energy neutrinos and the astrophysics and particle physics phenomena that can be probed by measuring such signals. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Penn State Univ, University Pk, PA 16802 USA. RP Mocioiu, I (reprint author), Argonne Natl Lab, HEP-362, Argonne, IL 60439 USA. EM irina@theory.uchicago.edu NR 86 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 10 PY 2005 VL 20 IS 30 BP 7079 EP 7105 DI 10.1142/S0217751X05028843 PG 27 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BS UT WOS:000234727600001 ER PT J AU Stephenson, GJ Goldman, T McKellar, BHJ Garbutt, M AF Stephenson, GJ Goldman, T McKellar, BHJ Garbutt, M TI Large mixing from small: Pseudo-Dirac neutrinos and the singular seesaw (vol 20, pg 6373, 2005) SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Correction C1 Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Melbourne, Parkville, Vic 3052, Australia. RP Stephenson, GJ (reprint author), Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. EM GJS@baryon.phys.unm.edu; tgoldman@lanl.gov; b.mckellar@physics.unimelb.edu.au; mgarbutt@treasury.gov.au NR 1 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD DEC 10 PY 2005 VL 20 IS 30 BP 7287 EP 7287 DI 10.1142/S0217751X05031046 PG 1 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 004BS UT WOS:000234727600014 ER PT J AU Potapenko, DV Horn, JM White, MG AF Potapenko, DV Horn, JM White, MG TI The reactions of cyclohexene on Au(111)-supported molybdenum carbide nanoparticles SO JOURNAL OF CATALYSIS LA English DT Article DE reactive deposition; molybdenum carbide; nanoparticle; Au(111); encapsulation; cyclohexene; dehydrogenation ID INITIAL DENSITY DEPENDENCE; TRANSITION-METAL CARBIDES; CATALYTIC-PROPERTIES; TUNGSTEN CARBIDE; CARBON-MONOXIDE; ORGANIC VAPORS; N-BUTANE; SURFACE; REACTIVITY; METHANE AB The reactivity of cyclohexene on Au(111)-supported molybdenum carbide nanoparticles was studied using temperature-programmed desorption (TPD) and Auger electron spectroscopy (AES) techniques. The surfaces were prepared by reactive layer-assisted deposition (RLAD), in which Mo metal is deposited onto ethylene adsorbed on a Au(111) surface, followed by annealing to 700 K. We have shown that gold encapsulates the MoCx nanoparticles to some extent on annealing. This encapsulation can be removed by ion sputtering at room temperature. Although the sputtered MoCx/Au(111) surface was very reactive toward adsorbed cyclohexene, the selectivity for partial dehydrogenation to benzene was very poor (0.06), with most of the reacting cyclohexene decomposing to surface carbon and molecular hydrogen. In contrast, the Au-encapsulated MoCx nanoparticles exhibit low total activity, but very high (>0.95) selectivity for partial dehydrogenation to benzene, with no detectable decomposition to surface carbon. The low overall reactivity and high selectivity of Au-encapsulated MoCx surfaces for partial cyclohexene dehydrogenation are explained by gold selectively blocking high reactivity sites on the MoCx clusters. (c) 2005 Elsevier Inc. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RP White, MG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM mgwhite@bnl.gov NR 54 TC 7 Z9 7 U1 2 U2 33 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 DEC 10 PY 2005 VL 236 IS 2 BP 346 EP 355 DI 10.1016/j.jcat.2005.09.029 PG 10 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 991RG UT WOS:000233830700016 ER PT J AU Chang, BK Jang, BW Dai, S Overbury, SH AF Chang, BK Jang, BW Dai, S Overbury, SH TI Transient studies of the mechanisms of CO oxidation over Au/TiO2 using time-resolved FTIR spectroscopy and product analysis SO JOURNAL OF CATALYSIS LA English DT Article DE CO catalytic oxidation; Au/TiO2 catalyst; FTIR; mass spectrometry; adsorption; desorption; rate-limiting step; operando spectroscopy ID CARBON-MONOXIDE OXIDATION; CATALYTIC-ACTIVITY; SUPPORTED GOLD; ROOM-TEMPERATURE; PARTICLE-SIZE; 90 K; TIO2; AU; NANOPARTICLES; PERFORMANCE AB Transient studies on the oxidation of CO over Au/TiO2 have been performed at 243-363 K using a time-resolved fast-scanning Fourier transform infrared (FTIR) spectrometer coupled with a quadrupole mass spectrometer. Different CO-O-2 interactions were performed by stepping CO into a steady-state He flow, O-2 into a steady-state CO flow, CO into a steady-state O-2 flow, and CO/O-2 into an He flow. The CO oxidation reaction occurs at all temperature ranges investigated whether CO is preadsorbed or O-2 is preadsorbed, indicating that there is no competition between CO and O-2 for adsorption at a temperature range of 243-363 K (noncompetitive adsorption). It suggests that CO and O-2 adsorption occurs on two different types of sites. When there is no O-2 present in step feed (i.e., step CO into He), CO immediately builds up on the surface (rapid adsorption of CO) and desorbs slowly after cutting off CO flow. However, when O-2 is present in the step feed (i.e., step CO/O-2 into He), adsorbed CO reacts with adsorbed oxygen immediately (fast surface reaction), whereas CO2 product desorption monitored by mass spectroscopy appears to be very slow. Slow desorption Of CO2 product is claimed to be the rate-limiting step of CO oxidation over Au/TiO2 at a temperature range of 243-273 K. (c) 2005 Elsevier Inc. All rights reserved. C1 Oak Ridge Natl Lab, Surface Chem & Heterogeneous Catalysis, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Overbury, SH (reprint author), Oak Ridge Natl Lab, Surface Chem & Heterogeneous Catalysis, Div Chem Sci, POB 2008,Bethel Valley Rd,Bldg 4500N,MS-6201, Oak Ridge, TN 37831 USA. EM overburysh@ornl.gov RI Overbury, Steven/C-5108-2016; Dai, Sheng/K-8411-2015 OI Overbury, Steven/0000-0002-5137-3961; Dai, Sheng/0000-0002-8046-3931 NR 32 TC 32 Z9 35 U1 2 U2 49 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 DEC 10 PY 2005 VL 236 IS 2 BP 392 EP 400 DI 10.1016/j.jcat.2005.10.006 PG 9 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 991RG UT WOS:000233830700021 ER PT J AU O'Hern, TJ Weckman, EJ Gerhart, AL Tieszen, SR Schefer, RW AF O'Hern, TJ Weckman, EJ Gerhart, AL Tieszen, SR Schefer, RW TI Experimental study of a turbulent buoyant helium plume SO JOURNAL OF FLUID MECHANICS LA English DT Article ID PARTICLE IMAGE VELOCIMETRY; LASER-INDUCED FLUORESCENCE; METHANE FIRE; NEAR-FIELD; SIMULATION; ACETONE AB An experimental study has been performed on the dynamics of a large turbulent buoyant helium plume. Two-dimensional velocity fields were measured using particle image velocimetry (PIV) while helium mass fraction was determined by planar laser-induced fluorescence (PLIF). PIV and PLIF were performed simultaneously in order to obtain velocity and mass fraction data over a plane that encompassed the plume core, the near-field mixing zones and the surrounding air. The Rayleigh-Taylor instability at the base of the plume leads to the vortex that grows to dominate the flow. This process repeats in a cyclical manner. The temporally and spatially resolved data show a strong negative correlation between density and vertical velocity, as well as a strong 90 degrees phase lag between peaks in the vertical and horizontal velocities throughout the flow field owing to large coherent structures associated with puffing of the turbulent plume. The joint velocity and mass fraction data are used to calculate Favre-averaged statistics in addition to Reynolds-(time) averaged statistics. Unexpectedly, the difference between both the Favre-averaged and Reynolds-averaged velocities and second-order turbulent statistics is less than the uncertainty in the data throughout the flow field. A simple analysis was performed to determine the expected differences between Favre and Reynolds statistics for flows with periodic fluctuations in which the density and velocity fields are perfectly correlated, but have the phase relations as suggested by the data. The analytical results agree with the data, showing that the Favre and Reynolds statistics will be the same to lead order. The combination of observation and simple analysis suggests that for buoyancy-dominated flows in which it can be expected that density and velocity are strongly correlated, phase relations will result in only second-order differences between Favre-and Reynolds-averaged data in spite of strong fluctuations in both density and velocity. C1 Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. Univ Waterloo, Dept Mech Engn, Waterloo, ON N2L 3G1, Canada. Lawrence Technol Univ, Dept Engn Mech, Southfield, MI 48075 USA. Sandia Natl Labs, Diagnost & Reacting Flow Dept, Livermore, CA 94551 USA. RP O'Hern, TJ (reprint author), Sandia Natl Labs, Engn Sci Ctr, POB 5800, Albuquerque, NM 87185 USA. RI Schefer, Jurg/G-3960-2012 NR 22 TC 19 Z9 19 U1 1 U2 11 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD DEC 10 PY 2005 VL 544 BP 143 EP 171 DI 10.1017/S0022112005006567 PG 29 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 994EG UT WOS:000234012800007 ER PT J AU Donfack, J Schneider, DH Tan, Z Kurz, T Dubchak, I Frazer, KA Ober, C AF Donfack, J Schneider, DH Tan, Z Kurz, T Dubchak, I Frazer, KA Ober, C TI Variation in conserved non-coding sequences on chromosome 5q and susceptibility to asthma and atopy SO RESPIRATORY RESEARCH LA English DT Article ID SERUM IGE LEVELS; LIQUID-CHROMATOGRAPHY DHPLC; ETHNICALLY DIVERSE POPULATIONS; GENOME-WIDE SEARCH; IL-4 GENE; PROMOTER POLYMORPHISM; COORDINATE REGULATOR; INTERLEUKIN-13 GENE; FOUNDER POPULATION; JAPANESE FAMILIES AB Background: Evolutionarily conserved sequences likely have biological function. Methods: To determine whether variation in conserved sequences in non-coding DNA contributes to risk for human disease, we studied six conserved non-coding elements in the Th2 cytokine cluster on human chromosome 5q31 in a large Hutterite pedigree and in samples of outbred European American and African American asthma cases and controls. Results: Among six conserved non-coding elements (> 100 bp, > 70% identity; human-mouse comparison), we identified one single nucleotide polymorphism ( SNP) in each of two conserved elements and six SNPs in the flanking regions of three conserved elements. We genotyped our samples for four of these SNPs and an additional three SNPs each in the IL13 and IL4 genes. While there was only modest evidence for association with single SNPs in the Hutterite and European American samples (P < 0.05), there were highly significant associations in European Americans between asthma and haplotypes comprised of SNPs in the IL4 gene (P < 0.001), including a SNP in a conserved non-coding element. Furthermore, variation in the IL13 gene was strongly associated with total IgE (P = 0.00022) and allergic sensitization to mold allergens (P = 0.00076) in the Hutterites, and more modestly associated with sensitization to molds in the European Americans and African Americans (P < 0.01). Conclusion: These results indicate that there is overall little variation in the conserved non-coding elements on 5q31, but variation in IL4 and IL13, including possibly one SNP in a conserved element, influence asthma and atopic phenotypes in diverse populations. C1 Univ Chicago, Dept Human Genet, Chicago, IL 60637 USA. Perlegen Sci, Mountain View, CA 94043 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Ober, C (reprint author), Univ Chicago, Dept Human Genet, 920 E 58th St, Chicago, IL 60637 USA. EM jdonfack@yahoo.com; dschneid@genetics.bsd.uchicago.edu; tzheng@genetics.bsd.uchicago.edu; eine_mail@yahoo.de; ildubchak@lbl.gov; Kelly_Frazer@perlegen.com; c-ober@genetics.uchicago.edu FU NCRR NIH HHS [M01 RR000055, M01 RR00055]; NHLBI NIH HHS [HL56399, HL66533, P50 HL056399, R01 HL066533, U01 HL049596] NR 55 TC 33 Z9 35 U1 0 U2 2 PU BIOMED CENTRAL LTD PI LONDON PA MIDDLESEX HOUSE, 34-42 CLEVELAND ST, LONDON W1T 4LB, ENGLAND SN 1465-9921 J9 RESP RES JI Respir. Res. PD DEC 10 PY 2005 VL 6 AR 145 DI 10.1186/1465-9921-6-145 PG 12 WC Respiratory System SC Respiratory System GA 000UI UT WOS:000234487500001 PM 16336695 ER PT J AU Alfonso, DR AF Alfonso, DR TI First-principles study of sulfur overlayers on Pd(111) surface SO SURFACE SCIENCE LA English DT Article DE chemisorption; density functional theory calculations; sulfur; metallic surfaces; adatoms; low index single crystal surfaces; surface electronic phenomena (work function, surface potential; surface states, etc) ID GENERALIZED GRADIENT APPROXIMATION; ENERGY ELECTRON-DIFFRACTION; INITIO MOLECULAR-DYNAMICS; ADSORBATE STRUCTURE; ADSORPTION; HYDROGEN; PALLADIUM; METAL; PSEUDOPOTENTIALS; CHEMISORPTION AB We present gradient corrected density functional theory investigations of the adsorption of sulfur on the Pd(I 11) surface for a wide range of coverages up to a monolayer (ML). Adsorption of atomic S on the fcc hollow sites is the most energetically favorable at low and medium coverages (<= 0.50 ML). Our studies suggest that at low coverages, island formation with a (root 3 x root 3) structure will occur in agreement with experimental observations. At S coverages above 0.50 ML, we find a tendency to form S-S bonds on the surface. Electronic density of states plots indicate that as S coverage increases, a weakening of the S-Pd interactions occurs which is compensated by enhancement of the S-S interactions. (c) 2005 Elsevier B.V. All rights reserved. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Parsons Project Serv Inc, South Pk, PA 15129 USA. RP Alfonso, DR (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. EM alfonso@net1.doe.gov NR 46 TC 30 Z9 32 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 10 PY 2005 VL 596 IS 1-3 BP 229 EP 241 DI 10.1016/j.susc.2005.09.021 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 987CL UT WOS:000233495900026 ER PT J AU Kim, YK Ahn, JR Cho, ES An, KS Yeom, HW Koh, H Rotenberg, E Park, CY AF Kim, YK Ahn, JR Cho, ES An, KS Yeom, HW Koh, H Rotenberg, E Park, CY TI Order-disorder phase transition on the Pb-adsorbed Si(110) surface SO SURFACE SCIENCE LA English DT Article DE silicon; Pb; self-assembly; surface reconstruction; phase transition; photoemission spectroscopy ID ANGLE-RESOLVED PHOTOEMISSION; CHARGE-DENSITY-WAVE; CRYSTAL STABILITY; QUANTUM CHAINS; FERROELECTRICITY; SILICON AB A new reversible temperature-dependent phase transition on Pb/Si(110) was found by photoemission spectroscopy and low energy electron diffraction. The room temperature 1 x 1 surface was found to transit into low temperature 4 x 2 with a transition temperature of roughly 200 K. The phase transition does not induce a temperature-dependent variation in both the energy bands and the Si 2p and Pb 5d spectra. This indicates that the phase transition is close to an order-disorder one. (c) 2005 Published by Elsevier B.V. C1 Sungkyunkwan Univ, BK21 Phys Res Div, Suwon 440746, South Korea. Sungkyunkwan Univ, Inst Basic Sci, Suwon 440746, South Korea. Sungkyunkwan Univ, CNNC, Suwon 440746, South Korea. Korea Res Inst Chem Technol, Thin Film Mat Lab, Taejon 305600, South Korea. Yonsei Univ, Ctr Atom Wires & Layers, Seoul 120746, South Korea. Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Park, CY (reprint author), Sungkyunkwan Univ, BK21 Phys Res Div, Suwon 440746, South Korea. EM cypark@skku.edu RI Rotenberg, Eli/B-3700-2009 OI Rotenberg, Eli/0000-0002-3979-8844 NR 27 TC 5 Z9 5 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 10 PY 2005 VL 596 IS 1-3 BP L325 EP L330 DI 10.1016/j.susc.2005.09.020 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 987CL UT WOS:000233495900002 ER PT J AU Gritti, F Guiochon, G AF Gritti, F Guiochon, G TI Effect of the endcapping of reversed-phase high-performance liquid chromatography adsorbents on the adsorption isotherm SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE adsorption equilibrium; frontal analysis; overloaded band profiles; column heterogeneity; affinity energy distribution; end-capping; resolve-C-18; symmetry-C-18; 4-tert-butylphenol; caffeine; propylbenzoate ID OVERLOADED BAND PROFILES; MASS-TRANSFER KINETICS; IONIZABLE COMPOUNDS; IONIC-STRENGTH; RETENTION; MECHANISM; BEHAVIOR; SILICA; SALTS; KROMASIL-C-18 AB The retention mechanisms of n-propylbenzoate, 4-tert-butylphenol, and caffeine on the endcapped Symmetry-Cls and the non-endcapped Resolve-C-18 are compared. The adsorption isotherms were measured by frontal analysis (FA), using as the mobile phase mixtures of methanol or acetonitrile and water of various compositions. The isotherm data were modeled and the adsorption energy distributions calculated. The surface heterogeneity increases faster with decreasing methanol concentration on the non-endcapped than on the endcapped adsorbent. For instance, for methanol concentrations exceeding 30% (v/v), the adsorption of caffeine is accounted for by assuming three and two different types of adsorption sites on Resolve-C-18 and Symmetry-C-18, respectively. This is explained by the effect of the mobile phase composition on the structure of the C-18-bonded layer. The bare surface of bonded silica appears more accessible to solute molecules at high water contents in the mobile phase, On the other hand, replacing methanol by a stronger organic modifier like acetonitrile dampens the differences between non-endcapped and endcapped stationary phase and decreases the degree of surface heterogeneity of the adsorbent. For instance, at acetonitrile concentrations exceeding 20%, the surface appears nearly homogeneous for the adsorption of caffeine. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 27 TC 14 Z9 14 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD DEC 9 PY 2005 VL 1098 IS 1-2 BP 82 EP 94 DI 10.1016/j.chroma.2005.08.045 PG 13 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 993KY UT WOS:000233954200011 PM 16314164 ER PT J AU Zhang, XX Wang, C Chen, T Wang, YL Tan, A Wu, TS Germany, GA Wang, W AF Zhang, XX Wang, C Chen, T Wang, YL Tan, A Wu, TS Germany, GA Wang, W TI Global patterns of Joule heating in the high-latitude ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; HEIGHT-INTEGRATED CONDUCTIVITY; POLAR-CAP POTENTIALS; ENERGY FLUX; SOLAR-WIND; THERMOSPHERE-IONOSPHERE; AURORAL SUBSTORMS; EMPIRICAL-MODEL; POYNTING FLUX; NEUTRAL WINDS AB [1] A compiled empirical global Joule heating (CEJH) model is described in this study. This model can be used to study Joule heating patterns, Joule heating power, potential drop, and polar potential size in the high-latitude ionosphere and thermosphere, and their variations with solar wind conditions, geomagnetic activities, the solar EUV radiation, and the neutral wind. It is shown that the interplanetary magnetic field ( IMF) orientation and its magnitude, the solar wind speed, AL index, geomagnetic K-p index, and solar radio flux F-10.7 index are important parameters that control Joule heating patterns, Joule heating power, potential drop, and polar potential size. Other parameters, such as the solar wind number density (N-sw) and Earth's dipole tilt, do not significantly affect these quantities. It is also shown that the neutral wind can increase or reduce the Joule heating production, and its effectiveness mainly depends on the IMF orientation and its magnitude, the solar wind speed, AL index, K-p index, and F10.7 index. Our results indicate that for less disturbed solar wind conditions, the increase or reduction of the neutral wind contribution to the Joule heating is not significant compared to the convection Joule heating, whereas under extreme solar wind conditions, the neutral wind can significantly contribute to the Joule heating. Application of the CEJH model to the 16 July 2000 storm implies that the model outputs are basically consistent with the results from the AMIE mapping procedure. The CEJH model can be used to examine large-scale energy deposition during disturbed solar wind conditions and to study the dependence of the hemispheric Joule heating on the level of geomagnetic activities and the intensity of solar EUV radiation. This investigation enables us to predict global Joule heating patterns for other models in the high-latitude ionosphere and thermosphere in the sense of space weather forecasting. C1 Chinese Acad Sci, Ctr Space Sci & Appl Res, Key Lab Space Weather, Beijing 100080, Peoples R China. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Alabama A&M Univ, Dept Phys, Normal, AL 35762 USA. Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. RP Zhang, XX (reprint author), Auburn Univ, Dept Phys, Allison Lab 206, Auburn, AL 36849 USA. EM xxzhang@physics.auburn.edu; cw@spaceweather.ac.cn; tchen@center.cssar.ac.cn; ywang@lanl.gov; arjun.tan@email.aamu.edu; wus@cspar.uah.edu; germanyg@cspar.uah.edu; wbwang@hao.ucar.edu RI Wang, Wenbin/G-2596-2013 OI Wang, Wenbin/0000-0002-6287-4542 NR 51 TC 14 Z9 14 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 9 PY 2005 VL 110 IS A12 AR A12208 DI 10.1029/2005JA011222 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 997MW UT WOS:000234250600003 ER PT J AU Lewis, FD Sajimon, MC Zuo, XB Rubin, M Gevorgyan, V AF Lewis, FD Sajimon, MC Zuo, XB Rubin, M Gevorgyan, V TI Competitive 1,2-and 1,5-hydrogen shifts following 2-vinylbiphenyl photocyclization SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID DENSITY; KINETICS; EXCHANGE AB The photocyclization of 2-vinylbiphenyl and its derivatives has been proposed to occur via a two-step mechanism: photocyclization to form an unstable 8a,9-dihydro-phenanthrene intermediate, followed by exothermic unimolecular isomerization to a 9,10-dihydrophenanthrene. The mechanism of the hydrogen shift process has been investigated using deuterated derivatives of 2-isopropenyl-biphenyl and 2,6-diphenylstyrene. H-1 NMR analysis of the photoproducts indicates that the thermally allowed 1,5-hydrogen or deuterium shift is a minor product-forming pathway and that an unusual double 1,2-hydrogen or deuterium shift is the major product-forming pathway. The potential energy surface for photocyclization and hydrogen shift processes has been explored computationally. The calculated barrier for the 1,5-shift is predicted to be significantly lower than that for the 1,2-shift. Alternative mechanisms for the occurrence of 1,2-hydrogen or deuterium migration are presented. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. RP Lewis, FD (reprint author), Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. EM lewis@chem.northwestern.edu RI Zuo, Xiaobing/F-1469-2010; Gevorgyan, Vladimir/L-7822-2014; Rubin, Michael/N-5699-2016; OI Gevorgyan, Vladimir/0000-0002-7836-7596; Rubin, Michael/0000-0002-1668-9311; Zuo, Xiaobing/0000-0002-0134-4804 NR 31 TC 10 Z9 10 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD DEC 9 PY 2005 VL 70 IS 25 BP 10447 EP 10452 DI 10.1021/jo051730y PG 6 WC Chemistry, Organic SC Chemistry GA 990RS UT WOS:000233761500027 PM 16323856 ER PT J AU Airapetian, A Akopov, N Akopov, Z Amarian, M Ammosov, VV Andrus, A Aschenauer, EC Augustyniak, W Avakian, R Avetissian, A Avetissian, E Bailey, P Balin, D Baturin, V Beckmann, M Belostotski, S Bernreuther, S Bianchi, N Blok, HP Bottcher, H Borissov, A Borysenko, A Bouwhuis, M Brack, J Brull, A Bryzgalov, V Capitani, GP Chen, T Chiang, HC Ciullo, G Contalbrigo, M Dalpiaz, PF Leo, RD Demey, M Nardo, LD Sanctis, ED Devitsin, E Nezza, PD Dreschler, J Duren, M Ehrenfried, M Elalaoui-Moulay, A Elbakian, G Ellinghaus, F Elschenbroich, U Fabbri, R Fantoni, A Fechtchenko, A Felawka, L Fox, B Frullani, S Gapienko, G Gapienko, V Garibaldi, F Garrow, K Garutti, E Gaskell, D Gavrilov, G Gharibyan, V Graw, G Grebeniouk, O Greeniaus, LG Gregor, IM Hafidi, K Hartig, M Hasch, D Heesbeen, D Henoch, M Hertenberger, R Hesselink, WHA Hillenbrand, A Hoek, M Holler, Y Hommez, B Iarygin, G Ivanilov, A Izotov, A Jackson, HE Jgoun, A Kaiser, R Kinney, E Kisselev, A Kopytin, M Korotkov, V Kozlov, V Krauss, B Krivokhijine, VG Lagamba, L Lapikas, L Laziev, A Lenisa, P Liebing, P Linden-Levy, LA Lipka, K Lorenzon, W Lu, H Lu, J Lu, S Ma, BQ Maiheu, B Makins, NCR Mao, Y Marianski, B Marukyan, H Masoli, F Mexner, V Meyners, N Mikloukho, O Miller, CA Miyachi, Y Muccifora, V Nagaitsev, A Nappi, E Naryshkin, Y Nass, A Negodaev, M Nowak, WD Oganessyan, K Ohsuga, H Pickert, N Potashov, S Potterveld, DH Raithel, M Reggiani, D Reimer, PE Reischl, A Reolon, AR Riedl, C Rith, K Rosner, G Rostomyan, A Rubacek, L Rubin, J Ryckbosch, D Salomatin, Y Sanjiev, I Savin, I Schafer, A Schill, C Schnell, G Schuler, KP Seele, J Seidl, R Seitz, B Shanidze, R Shearer, C Shibata, TA Shutov, V Simani, MC Sinram, K Stancari, M Statera, M Steffens, E Steijger, JJM Stenzel, H Stewart, J Stinzing, F Stosslein, U Tait, P Tanaka, H Taroian, S Tchuiko, B Terkulov, A Tkabladze, A Trzcinski, A Tytgat, M Vandenbroucke, A van der Nat, PB van der Steenhoven, G Vetterli, MC Vikhrov, V Vincter, MG Vogel, C Vogt, M Volmer, J Weiskopf, C Wendland, J Wilbert, J Ye, Y Ye, Z Yen, S Zihlmann, B Zupranski, P AF Airapetian, A Akopov, N Akopov, Z Amarian, M Ammosov, VV Andrus, A Aschenauer, EC Augustyniak, W Avakian, R Avetissian, A Avetissian, E Bailey, P Balin, D Baturin, V Beckmann, M Belostotski, S Bernreuther, S Bianchi, N Blok, HP Bottcher, H Borissov, A Borysenko, A Bouwhuis, M Brack, J Brull, A Bryzgalov, V Capitani, GP Chen, T Chiang, HC Ciullo, G Contalbrigo, M Dalpiaz, PF Leo, RD Demey, M Nardo, LD Sanctis, ED Devitsin, E Nezza, PD Dreschler, J Duren, M Ehrenfried, M Elalaoui-Moulay, A Elbakian, G Ellinghaus, F Elschenbroich, U Fabbri, R Fantoni, A Fechtchenko, A Felawka, L Fox, B Frullani, S Gapienko, G Gapienko, V Garibaldi, F Garrow, K Garutti, E Gaskell, D Gavrilov, G Gharibyan, V Graw, G Grebeniouk, O Greeniaus, LG Gregor, IM Hafidi, K Hartig, M Hasch, D Heesbeen, D Henoch, M Hertenberger, R Hesselink, WHA Hillenbrand, A Hoek, M Holler, Y Hommez, B Iarygin, G Ivanilov, A Izotov, A Jackson, HE Jgoun, A Kaiser, R Kinney, E Kisselev, A Kopytin, M Korotkov, V Kozlov, V Krauss, B Krivokhijine, VG Lagamba, L Lapikas, L Laziev, A Lenisa, P Liebing, P Linden-Levy, LA Lipka, K Lorenzon, W Lu, H Lu, J Lu, S Ma, BQ Maiheu, B Makins, NCR Mao, Y Marianski, B Marukyan, H Masoli, F Mexner, V Meyners, N Mikloukho, O Miller, CA Miyachi, Y Muccifora, V Nagaitsev, A Nappi, E Naryshkin, Y Nass, A Negodaev, M Nowak, WD Oganessyan, K Ohsuga, H Pickert, N Potashov, S Potterveld, DH Raithel, M Reggiani, D Reimer, PE Reischl, A Reolon, AR Riedl, C Rith, K Rosner, G Rostomyan, A Rubacek, L Rubin, J Ryckbosch, D Salomatin, Y Sanjiev, I Savin, I Schafer, A Schill, C Schnell, G Schuler, KP Seele, J Seidl, R Seitz, B Shanidze, R Shearer, C Shibata, TA Shutov, V Simani, MC Sinram, K Stancari, M Statera, M Steffens, E Steijger, JJM Stenzel, H Stewart, J Stinzing, F Stosslein, U Tait, P Tanaka, H Taroian, S Tchuiko, B Terkulov, A Tkabladze, A Trzcinski, A Tytgat, M Vandenbroucke, A van der Nat, PB van der Steenhoven, G Vetterli, MC Vikhrov, V Vincter, MG Vogel, C Vogt, M Volmer, J Weiskopf, C Wendland, J Wilbert, J Ye, Y Ye, Z Yen, S Zihlmann, B Zupranski, P TI Measurement of the tensor structure function b(1) of the deuteron SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN STRUCTURE FUNCTIONS; POLARIZED DEUTERONS; ELECTRON-SCATTERING; ONE HADRONS; PROTON AB The Hermes experiment has investigated the tensor spin structure of the deuteron using the 27.6 GeV/c positron beam of DESY HERA. The use of a tensor-polarized deuteron gas target with only a negligible residual vector polarization enabled the first measurement of the tensor asymmetry A(zz)(d) and the tensor structure function b(1)(d) for average values of the Bjorken variable 0.01 << x >< 0.45 and of the negative of the squared four-momentum transfer 0.5 GeV2<< Q(2)>< 5 GeV2. The quantities A(zz)(d) and b(1)(d) are found to be nonzero. The rise of b(1)(d) for decreasing values of x can be interpreted to originate from the same mechanism that leads to nuclear shadowing in unpolarized scattering. C1 Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Ist Nazl Fis Nucl, Sez Bari, I-70124 Bari, Italy. Peking Univ, Sch Phys, Beijing 100871, Peoples R China. Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Anhui, Peoples R China. Univ Colorado, Nucl Phys Lab, Boulder, CO 80309 USA. DESY, D-22603 Hamburg, Germany. DESY, D-15738 Zeuthen, Germany. Joint Inst Nucl Res, Dubna 141980, Russia. Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. State Univ Ghent, Dept Subatom & Radiat Phys, B-9000 Ghent, Belgium. Univ Giessen, Inst Phys, D-35392 Giessen, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. PN Lebedev Phys Inst, Moscow 117924, Russia. Univ Munich, Sekt Phys, D-85748 Garching, Germany. NIKHEF, NL-1009 DB Amsterdam, Netherlands. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Inst High Energy Phys, Moscow 142281, Russia. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Ist Super Sanita, Phys Lab, I-00161 Rome, Italy. Ist Nazl Fis Nucl, Sez Roma 1, Grp Sanita, I-00161 Rome, Italy. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Vrije Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. Andrzej Soltan Inst Nucl Studies, PL-00689 Warsaw, Poland. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Airapetian, A (reprint author), Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. RI Gavrilov, Gennady/C-6260-2013; Reimer, Paul/E-2223-2013; Negodaev, Mikhail/A-7026-2014; El Alaoui, Ahmed/B-4638-2015; Terkulov, Adel/M-8581-2015; OI Lagamba, Luigi/0000-0002-0233-9812; Hoek, Matthias/0000-0002-1893-8764 NR 30 TC 43 Z9 44 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 9 PY 2005 VL 95 IS 24 AR 242001 DI 10.1103/PhysRevLett.95.242001 PG 6 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100016 PM 16384369 ER PT J AU Choi, JH Guest, JR Povilus, AP Hansis, E Raithel, G AF Choi, JH Guest, JR Povilus, AP Hansis, E Raithel, G TI Magnetic trapping of long-lived cold Rydberg atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENTANGLEMENT; CAVITY; PLASMA AB We report on the trapping of long-lived strongly magnetized Rydberg atoms. Rb-85 atoms are laser cooled and collected in a superconducting magnetic trap with a strong bias field (2.9 T) and laser excited to Rydberg states. Collisions scatter a small fraction of the Rydberg atoms into long-lived high-angular momentum "guiding-center" Rydberg states, which are magnetically trapped. The Rydberg atomic cloud is examined using a time-delayed, position-sensitive probe. We observe magnetic trapping of these Rydberg atoms for times up to 200 ms. Oscillations of the Rydberg-atom cloud in the trap reveal an average magnetic moment of the trapped Rydberg atoms of approximate to-8 mu(B). These results provide guidance for other Rydberg-atom trapping schemes and illuminate a possible route for trapping antihydrogen. C1 Univ Michigan, Dept Phys, FOCUS Ctr, Ann Arbor, MI 48109 USA. RP Choi, JH (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Guest, Jeffrey/B-2715-2009 OI Guest, Jeffrey/0000-0002-9756-8801 NR 29 TC 52 Z9 53 U1 0 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 9 PY 2005 VL 95 IS 24 AR 243001 DI 10.1103/PhysRevLett.95.243001 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100018 PM 16384371 ER PT J AU Edens, AD Ditmire, T Hansen, JF Edwards, MJ Adams, RG Rambo, PK Ruggles, L Smith, IC Porter, JL AF Edens, AD Ditmire, T Hansen, JF Edwards, MJ Adams, RG Rambo, PK Ruggles, L Smith, IC Porter, JL TI Measurement of the decay rate of single-frequency perturbations on blast waves SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERNOVA-REMNANTS; STAR FORMATION; INSTABILITY; SHOCKS AB To explore the validity of theories forwarded to explain the dynamics of hydrodynamic perturbations on high Mach number blast waves, we have studied the decay rate of perturbations on blast waves traveling through nitrogen gas. In our experiments, 1 kJ pulses from the Z-Beamlet laser at Sandia National Laboratories illuminated solid targets immersed in gas and created blast waves. The polytropic index implied by comparing experiment to theoretical predictions is compared to simulation results. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Sandia Natl Labs, Albuquerque, NM 87059 USA. RP Edens, AD (reprint author), Sandia Natl Labs, Albuquerque, NM 87122 USA. EM adedens@sandia.gov NR 19 TC 24 Z9 24 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 9 PY 2005 VL 95 IS 24 AR 244503 DI 10.1103/PhysRevLett.95.244503 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100032 PM 16384385 ER PT J AU He, LX Bester, G Zunger, A AF He, LX Bester, G Zunger, A TI Electronic phase diagrams of carriers in self-assembled quantum dots: Violation of Hund's rule and the Aufbau principle for holes SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPECTROSCOPY; INFORMATION; STORAGE; INGAAS AB We study the ground-state orbital and spin configurations of up to six electrons or holes loaded into self-assembled InAs/GaAs quantum dots. We use a general phase-diagram approach constructed from single-particle pseudopotential and many-particle configuration interaction methods. The predicted hole charging energies agree with recent charging experiments, but offer a different interpretation: we find that while the charging of electrons follows both Hund's rule and the Aufbau principle, the charging of holes follows a nontrivial charging pattern which violates both the Aufbau principle and Hund's rule. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP He, LX (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Bester, Gabriel/I-4414-2012; Zunger, Alex/A-6733-2013 OI Bester, Gabriel/0000-0003-2304-0817; NR 21 TC 22 Z9 22 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 9 PY 2005 VL 95 IS 24 AR 246804 DI 10.1103/PhysRevLett.95.246804 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100054 PM 16384407 ER PT J AU Spataru, CD Ismail-Beigi, S Capaz, RB Louie, SG AF Spataru, CD Ismail-Beigi, S Capaz, RB Louie, SG TI Theory and ab initio calculation of radiative lifetime of excitons in semiconducting carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUASI-PARTICLE ENERGIES; OPTICAL-SPECTRA; EXCITATIONS AB We present a theoretical analysis and first-principles calculation of the radiative lifetime of excitons in semiconducting carbon nanotubes. An intrinsic lifetime of the order of 10 ps is computed for the lowest optically active bright excitons. The intrinsic lifetime is, however, a rapid increasing function of the exciton momentum. Moreover, the electronic structure of the nanotubes dictates the existence of dark excitons near in energy to each bright exciton. Both effects strongly influence measured lifetime. Assuming a thermal occupation of bright and dark exciton bands, we find an effective lifetime of the order of 10 ns at room temperature, in good accord with recent experiments. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Yale Univ, Dept Appl Phys, New Haven, CT 06520 USA. Univ Fed Rio de Janeiro, Inst Fis, BR-21941972 Rio De Janeiro, Brazil. RP Spataru, CD (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Ismail-Beigi, Sohrab/F-2382-2014; B, Rodrigo/N-7595-2014 OI Ismail-Beigi, Sohrab/0000-0002-7331-9624; NR 26 TC 195 Z9 196 U1 7 U2 49 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 DEC 9 PY 2005 VL 95 IS 24 AR 247402 DI 10.1103/PhysRevLett.95.247402 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100069 PM 16384422 ER PT J AU Vu, HX Yin, L DuBois, DF Bezzerides, B Dodd, ES AF Vu, HX Yin, L DuBois, DF Bezzerides, B Dodd, ES TI Nonlinear spectral signatures and spatiotemporal behavior of stimulated raman scattering from single laser speckles SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARAMETRIC-INSTABILITIES; PLASMA-WAVES; HOT-SPOT AB Simulations are reported of the Thomson scatter spectrum of electrostatic waves (ESWs) excited in single laser hot spots by backward stimulated Raman scattering (BSRS). Under conditions similar those in the recent experiments of Kline et al. [Phys. Rev. Lett. 94, 175003 (2005)], a spectral streak, resulting from the trapping-induced frequency shift of the ESW, is found for high wave-number ESWs, similar to the observations. This shift and parametric frequency matching lead to isolated BSRS pulses. Modes with acoustic dispersion, resulting from the trapping-modified electron velocity distribution, can enhance the frequency range of the streak. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Vu, HX (reprint author), Univ Calif San Diego, La Jolla, CA 92093 USA. NR 13 TC 30 Z9 30 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 9 PY 2005 VL 95 IS 24 AR 245003 DI 10.1103/PhysRevLett.95.245003 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100037 PM 16384390 ER PT J AU Wang, YY Li, L Naughton, MJ Gu, GD Uchida, S Ong, NP AF Wang, YY Li, L Naughton, MJ Gu, GD Uchida, S Ong, NP TI Field-enhanced diamagnetism in the pseudogap state of the cuprate Bi2Sr2CaCu2O8+delta superconductor in an intense magnetic field SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUCTUATION-INDUCED DIAMAGNETISM; SUSCEPTIBILITY; EXCITATIONS; ANISOTROPY; LINE; CU AB In hole-doped cuprates, Nernst experiments imply that the superconducting state is destroyed by spontaneous creation of vortices which destroy phase coherence. Using torque magnetometry on Bi2Sr2CaCu2O8+delta, we uncover a field-enhanced diamagnetic signal M above the transition temperature T-c that increases with applied field to 32 Tesla and scales just like the Nernst signal. The magnetization results above T-c distinguish M from conventional amplitude fluctuations and strongly support the vortex scenario for the loss of phase coherence at T-c. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Sch Frontier Sci, Tokyo 1138656, Japan. RP Wang, YY (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RI Gu, Genda/D-5410-2013 OI Gu, Genda/0000-0002-9886-3255 NR 27 TC 173 Z9 174 U1 1 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 9 PY 2005 VL 95 IS 24 AR 247002 DI 10.1103/PhysRevLett.95.247002 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100056 PM 16384409 ER PT J AU Zhang, PJ Pen, UL AF Zhang, PJ Pen, UL TI Mapping dark matter with cosmic magnification SO PHYSICAL REVIEW LETTERS LA English DT Article ID LARGE-SCALE STRUCTURE; WEAK; GALAXIES; RECONSTRUCTION; EVOLUTION; SKEWNESS AB We develop a new tool to generate statistically precise dark matter maps from the cosmic magnification of galaxies with distance estimates. We show how to overcome the intrinsic clustering problem using the slope of the luminosity function, because magnification changes strongly over the luminosity function, while intrinsic clustering only changes weakly. This may allow precision cosmology beyond most current systematic limitations. The Square Kilometre Array is able to reconstruct the projected matter density map at smoothing scale similar to 10' with S/N >= 1, at the rate of 200-4000 deg(2) per year, depending on the abundance and evolution of 21 cm emitting galaxies. This power of mapping dark matter is comparable to, or even better than, that of cosmic shear from deep optical surveys or 21 cm surveys. C1 Fermilab Natl Accelerator Lab, Ctr Particle Astrophys, Batavia, IL 60510 USA. Chinese Acad Sci, Shanghai Astron Observ, Shanghai, Peoples R China. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. RP Zhang, PJ (reprint author), Fermilab Natl Accelerator Lab, Ctr Particle Astrophys, Batavia, IL 60510 USA. EM pjzhang@shao.ac.cn; pen@cita.utoronto.ca RI ZHANG, PENGJIE/O-2825-2015 NR 33 TC 34 Z9 35 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 DEC 9 PY 2005 VL 95 IS 24 AR 241302 DI 10.1103/PhysRevLett.95.241302 PG 4 WC Physics, Multidisciplinary SC Physics GA 991PO UT WOS:000233826100014 PM 16384367 ER PT J AU Mills, E AF Mills, E TI Attribution of disaster losses - Response SO SCIENCE LA English DT Letter ID IMPACTS; WEATHER C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Mills, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 90-4000, Berkeley, CA 94720 USA. EM emills@lbl.gov NR 12 TC 0 Z9 0 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 9 PY 2005 VL 310 IS 5754 BP 1616 EP 1616 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 993NV UT WOS:000233961700019 ER PT J AU Chrzan, DC AF Chrzan, DC TI Metallurgy in the age of silicon SO SCIENCE LA English DT Editorial Material C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Chrzan, DC (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. EM dcchrzan@berkeley.edu NR 6 TC 5 Z9 5 U1 3 U2 6 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 DEC 9 PY 2005 VL 310 IS 5754 BP 1623 EP 1624 DI 10.1126/science.1121019 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 993NV UT WOS:000233961700028 PM 16339433 ER PT J AU Bhalla, N Dernburg, AF AF Bhalla, N Dernburg, AF TI Conserved checkpoint monitors meiotic chromosome synapsis in Caenorhabditis elegans SO SCIENCE LA English DT Article ID DAMAGE-INDUCED APOPTOSIS; C-ELEGANS; CELL-DEATH; GENETIC-CONTROL; RECOMBINATION; GERMLINE; HOMOLOG; PROGRESSION; PROTEINS; MEIOSIS AB We report the discovery of a checkpoint that monitors synapsis between homologous chromosomes to ensure accurate meiotic segregation. Oocytes containing unsynapsed chromosomes selectively undergo apoptosis even if a germline DNA damage checkpoint is inactivated. This cutting mechanism is specifically activated by unsynapsed pairing centers, cis-acting chromosome sites that are also required to promote synapsis in Caenorhabditis elegans. Apoptosis due to synaptic failure also requires the C. elegans homolog of PCH2, a budding yeast pachytene checkpoint gene, which suggests that this surveillance mechanism is widely conserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Dernburg, AF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. EM afdernburg@lbl.gov FU NIGMS NIH HHS [1 F32 GM67408-01A1, 1 R01 GM/CA655591-01, F32 GM067408, F32 GM067408-01A1, F32 GM067408-02] NR 29 TC 104 Z9 116 U1 1 U2 6 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 DEC 9 PY 2005 VL 310 IS 5754 BP 1683 EP 1686 DI 10.1126/science.1117468 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 993NV UT WOS:000233961700046 PM 16339446 ER PT J AU Shah, N Teplitsky, MV Minovitsky, S Pennacchio, LA Hugenholtz, P Hamann, B Dubchak, IL AF Shah, N Teplitsky, MV Minovitsky, S Pennacchio, LA Hugenholtz, P Hamann, B Dubchak, IL TI SNP-VISTA: An interactive SNP visualization tool SO BMC BIOINFORMATICS LA English DT Article ID HUMAN GENOME; SEQUENCE; POLYMORPHISMS; GENE AB Background: Recent advances in sequencing technologies promise to provide a better understanding of the genetics of human disease as well as the evolution of microbial populations. Single Nucleotide Polymorphisms ( SNPs) are established genetic markers that aid in the identification of loci affecting quantitative traits and/or disease in a wide variety of eukaryotic species. With today's technological capabilities, it has become possible to re-sequence a large set of appropriate candidate genes in individuals with a given disease in an attempt to identify causative mutations. In addition, SNPs have been used extensively in efforts to study the evolution of microbial populations, and the recent application of random shotgun sequencing to environmental samples enables more extensive SNP analysis of co-occurring and co-evolving microbial populations. The program is available at http://genome.lbl.gov/vista/ snpvista[ 1]. Results: We have developed and present two modifications of an interactive visualization tool, SNP-VISTA, to aid in the analyses of the following types of data: A. Large-scale re-sequence data of disease-related genes for discovery of associated and/or causative alleles (GeneSNP-VISTA). B. Massive amounts of ecogenomics data for studying homologous recombination in microbial populations ( EcoSNP-VISTA). The main features and capabilities of SNP-VISTA are: 1) mapping of SNPs to gene structure; 2) classification of SNPs, based on their location in the gene, frequency of occurrence in samples and allele composition; 3) clustering, based on user-defined subsets of SNPs, highlighting haplotypes as well as recombinant sequences; 4) integration of protein evolutionary conservation visualization; and 5) display of automatically calculated recombination points that are user-editable. Conclusion: The main strength of SNP-VISTA is its graphical interface and use of visual representations, which support interactive exploration and hence better understanding of large-scale SNP data by the user. C1 Lawrence Berkeley Natl Lab, Genom Div, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Comp Sci, Inst Data Anal & Visualizat, Davis, CA 95616 USA. DOE Joint Genome Inst, Walnut Creek, CA 94598 USA. RP Dubchak, IL (reprint author), Lawrence Berkeley Natl Lab, Genom Div, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM nyshah@ucdavis.edu; mvteplitsky@yahoo.com; SMinovitsky@lbl.gov; LAPennacchio@lbl.gov; phugenholtz@lbl.gov; hamann@cs.ucdavis.edu; ildubchak@lbl.gov RI Hugenholtz, Philip/G-9608-2011 NR 17 TC 11 Z9 12 U1 0 U2 1 PU BIOMED CENTRAL LTD PI LONDON PA 236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND SN 1471-2105 J9 BMC BIOINFORMATICS JI BMC Bioinformatics PD DEC 8 PY 2005 VL 6 AR 292 DI 10.1186/1471-2105-6-292 PG 7 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Mathematical & Computational Biology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Mathematical & Computational Biology GA 999GW UT WOS:000234377900001 PM 16336665 ER PT J AU Xie, ZW Zhang, YB Guliaev, AB Shen, HY Hang, B Singer, B Wang, ZG AF Xie, ZW Zhang, YB Guliaev, AB Shen, HY Hang, B Singer, B Wang, ZG TI The p-benzoquinone DNA adducts derived from benzene are highly mutagenic SO DNA REPAIR LA English DT Article; Proceedings Paper CT Dale W Mosbaugh Memorial Symposium on Genetic Toxicology and DNA Repair CY OCT 11-12, 2004 CL Oregon State Univ, Corvallis, OR HO Oregon State Univ DE lesion bypass; translesion synthesis; mutagenesis; Y family DNA polymerase; polymerase zeta; benzene; DNA adducts ID HUMAN AP ENDONUCLEASE; MOLECULAR-DYNAMICS SIMULATIONS; SITE-SPECIFIC INCORPORATION; YEAST REV1 PROTEIN; TRANSLESION SYNTHESIS; LESION BYPASS; POLYMERASE-KAPPA; SACCHAROMYCES-CEREVISIAE; STRUCTURAL INSIGHTS; EXOCYCLIC ADDUCT AB Benzene is a human leukemia carcinogen, resulting from its cellular metabolism. A major benzene metabolite is p-benzoquinone (pBQ), which can damage DNA by forming the exocyclic base adducts pBQ-dC, pBQ-dA, and pBQ-dG in vitro. To gain insights into the role of pBQ in benzene genotoxicity, we examined in vitro translesion synthesis and in vivo mutagenesis of these pBQ adducts. Purified REV1 and POl kappa were essentially incapable of translesion synthesis in response to the pBQ adducts. Opposite pBQ-dA and pBQ-dC, purified human Pol kappa was capable of error-prone nucleotide insertion, but was unable to perform extension synthesis. Error-prone translesion synthesis was observed with Pol eta.. However, DNA synthesis largely stopped opposite the lesion. Consistent with in vitro results, replication of site-specifically damaged plasmids was strongly inhibited by pBQ adducts in yeast cells, which depended on both Pol xi and Pol eta. In wild-type cells, the majority of translesion products were deletions at the site of damage, accounting for 91%, 90%, and 76% for pBQ-dA, pBQ-dG, and pBQ-dC, respectively. These results show that the pBQ-dC, pBQ-dA, and pBQ-dG adducts are strong blocking lesions, and are highly mutagenic by predominantly inducing deletion mutations. These results are consistent with the lesion structures predicted by molecular dynamics simulation. Our results led to the following model. Translesion synthesis normally occurs by directly copying the lesion site through base insertion and extension synthesis. When the lesion becomes incompatible in accommodating a base opposite the lesion in DNA, translesion synthesis occurs by a less efficient lesion loop-out mechanism, resulting in avoiding copying the damaged base and leading to deletion. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Kentucky, Grad Ctr Toxicol, Lexington, KY 40536 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Univ Kentucky, Grad Ctr Toxicol, Lexington, KY 40536 USA. EM zwang@uky.edu RI Zhang, Yanbin/F-2998-2011 OI Zhang, Yanbin/0000-0002-7263-5510 FU NCI NIH HHS [CA47723, CA92528, CA72079] NR 58 TC 19 Z9 24 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1568-7864 EI 1568-7856 J9 DNA REPAIR JI DNA Repair PD DEC 8 PY 2005 VL 4 IS 12 BP 1399 EP 1409 DI 10.1016/j.dnarep.2005.08.012 PG 11 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA 994NP UT WOS:000234038800009 PM 16181813 ER PT J AU Gibbard, S Caldeira, K Bala, G Phillips, TJ Wickett, M AF Gibbard, S Caldeira, K Bala, G Phillips, TJ Wickett, M TI Climate effects of global land cover change SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UNITED-STATES; DESERT WORLD; GREEN PLANET; DEFORESTATION; VEGETATION; CIRCULATION AB When changing from grass and croplands to forest, there are two competing effects of land cover change on climate: an albedo effect which leads to warming and an evapotranspiration effect which tends to produce cooling. It is not clear which effect would dominate. We have performed simulations of global land cover change using the NCAR CAM3 atmospheric general circulation model coupled to a slab ocean model. We find that global replacement of current vegetation by trees would lead to a global mean warming of 1.3 degrees C, nearly 60% of the warming produced under a doubled CO2 concentration, while replacement by grasslands would result in a cooling of 0.4 degrees C. It has been previously shown that boreal forestation can lead to warming; our simulations indicate that mid-latitude forestation also could lead to warming. These results suggest that more research is necessary before forest carbon storage should be deployed as a mitigation strategy for global warming. C1 Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. Carnegie Inst Washington, Dept Global Ecol, Stanford, CA 94305 USA. RP Gibbard, S (reprint author), Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. EM bala@llnl.gov RI Caldeira, Ken/E-7914-2011 NR 22 TC 89 Z9 91 U1 0 U2 36 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 DEC 8 PY 2005 VL 32 IS 23 AR L23705 DI 10.1029/2005GL024550 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 997LN UT WOS:000234247000007 ER PT J AU Ronnebro, E Kyoi, D Kitano, A Kitano, Y Sakai, T AF Ronnebro, E Kyoi, D Kitano, A Kitano, Y Sakai, T TI Hydrogen sites analysed by X-ray synchrotron diffraction in Mg7TiH13-16 made at gigapascal high-pressures SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 9th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY SEP 05-10, 2004 CL AGH Univ Sci & Technol, Fac Phys & Comp Sci, Cracow, POLAND SP Polish Minist Sci & Informat Soc Technologies, LOT, Polish Airlines, TALES, SURPHARE, Hydrogen & Energy Sci Sci Instruments HO AGH Univ Sci & Technol, Fac Phys & Comp Sci DE hydrogen storage material; gas-solid reaction; X-ray diffraction; synchrotron radiation; high pressure ID HYDRIDES AB The structure of anew hydrogen rich Mg-based transition metal hydride, i.e. Mg7TiH16, was investigated with high-energy X-ray synchrotron radiation data from the facility SPring-8, Japan. The hydride phase was in advance prepared at 8 GPa and 873 K with a cubic anvil press. The high-energy beam also enabled hydrogen to be observed. With the Rietveld method the best result was obtained when two tetrahedral sites are fully occupied by hydrogen atoms with a minimum H-H distance of 1.8 angstrom. A sample that had been stored for a longer time before analysis appeared to have less hydrogen corresponding to the formula unit of Mg7TiH13 and also a smaller unit cell volume. (c) 2005 Elsevier B.V. All rights reserved. C1 AIST, Kansai Ctr, Ikeda, Osaka 563, Japan. JASRI, Sayo, Hyogo 6795198, Japan. Shimane Univ, Dept Mat Sci, Matsue, Shimane 6908504, Japan. RP Ronnebro, E (reprint author), Sandia Natl Labs, POB 969,MS 9403, Livermore, CA 94551 USA. EM ecronne@sandia.gov NR 9 TC 33 Z9 33 U1 2 U2 15 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 DEC 8 PY 2005 VL 404 BP 68 EP 72 DI 10.1016/j.jallcom.2005.03.106 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 995KV UT WOS:000234100100016 ER PT J AU Shanahan, KL Holder, JS AF Shanahan, KL Holder, JS TI Helium release behavior of aged titanium tritides SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 9th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY SEP 05-10, 2004 CL AGH Univ Sci & Technol, Fac Phys & Comp Sci, Cracow, POLAND SP Polish Minist Sci & Informat Soc Technologies, LOT, Polish Airlines, TALES, SURPHARE, Hydrogen & Energy Sci Sci Instruments HO AGH Univ Sci & Technol, Fac Phys & Comp Sci DE tritium; titanium; helium AB One sample of bulk Ti has been loaded with a 50%/50% deuterium/tritium (D/T) mixture and statically aged for 6.5 years. Thermal desorption of the sample shows an initial release of hydrogen isotopes followed by He-3 release. Subsequent D-2 loading/desorption was used to quantify the trapped tritium heel. The sample shows an excess hydrogen capacity as a second thermal desorption peak that partially disappears and shifts with annealing at 923-973 K. The main hydrogen desorption peak also shifts to higher temperature, indicating a partial reversal of the tritium-decay induced damage by annealing. (c) 2005 Published by Elsevier B.V. C1 Savannah River Natl Lab, Aiken, SC 29808 USA. RP Shanahan, KL (reprint author), Savannah River Natl Lab, Bldg 735-11A, Aiken, SC 29808 USA. EM kirk.shanahan@srs.gov NR 4 TC 11 Z9 13 U1 1 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 DEC 8 PY 2005 VL 404 BP 365 EP 367 DI 10.1016/j.jallcom.2004.12.194 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 995KV UT WOS:000234100100084 ER PT J AU Luo, W Ronnebro, E AF Luo, W Ronnebro, E TI Towards a viable hydrogen storage system for transportation application SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 9th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY SEP 05-10, 2004 CL AGH Univ Sci & Technol, Fac Phys & Comp Sci, Cracow, POLAND SP Polish Minist Sci & Informat Soc Technologies, LOT, Polish Airlines, TALES, SURPHARE, Hydrogen & Energy Sci Sci Instruments HO AGH Univ Sci & Technol, Fac Phys & Comp Sci DE hydrogen storage materials; gas-solid reaction; thermodynamic characterization ID HYDRIDES; IMIDES AB Hydrogen energy may provide the means to an environmentally friendly future. One of the problems related to its application for transportation is "on-board" storage. Hydrogen storage in solids has long been recognized as one of the most practical approaches for this purpose. The H-capacity in interstitial hydrides of most metals and alloys is limited to below 2.5% by weight and this is unsatisfactory for on-board transportation applications. Magnesium hydride is an exception with hydrogen capacity of similar to 8.2 wt.%, however, its operating temperature, above 350 degrees C, is too high for practical use. Sodium alanate (NaAlH4) absorbs hydrogen up to 5.6 wt.% theoretically; however, its reaction kinetics and partial reversibility do not completely meet the new target for transportation application. Recently Chen et al. [1] reported that (Li3N + 2H(2) <-> LiNH2 + 2LiH) provides a storage material with a possible high capacity, up to 11.5 wt.%, although this material is still too stable to meet the operating pressure/temperature requirement. Here we report a new approach to destabilize lithium imide system by partial substitution of lithium by magnesium in the (LiNH2 + LiH <-> Li2NH + H-2) system with a minimal capacity loss. This Mg-substituted material can reversibly absorb 5.2 wt.% hydrogen at pressure of 30 bar at 200 degrees C. This is a very promising material for on-board hydrogen storage applications. It is interesting to observe that the starting material (2LiNH(2) + MgH2) converts to (Mg(NH2)(2) + 2UH) after a desorption/re-absorption cycle. (c) 2005 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Luo, W (reprint author), Sandia Natl Labs, MS 9403, Livermore, CA 94550 USA. EM wluo@sandia.gov RI Mahalingam, Arjun/G-8586-2011 NR 14 TC 74 Z9 76 U1 2 U2 23 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 DEC 8 PY 2005 VL 404 BP 392 EP 395 DI 10.1016/j.jallcom.2005.01.131 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 995KV UT WOS:000234100100090 ER PT J AU Gijsbertsen, A Linnartz, H Rus, G Wiskerke, AE Stolte, S Chandler, DW Klos, J AF Gijsbertsen, A Linnartz, H Rus, G Wiskerke, AE Stolte, S Chandler, DW Klos, J TI Differential cross sections for collisions of hexapole state-selected NO with He SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROTATIONALLY INELASTIC-COLLISIONS; FINE-STRUCTURE TRANSITIONS; BOUND ROVIBRATIONAL STATES; POTENTIAL-ENERGY SURFACES; PI-ELECTRONIC STATES; STERIC ASYMMETRY; MOLECULAR-COLLISIONS; SCATTERING; PROPENSITIES; NO(X(2)PI) AB The first measurements of differential inelastic collision cross sections of fully state-selected NO (j=1/2, Omega=1/2, epsilon=-1) with He are presented. Full state selection is achieved by a 2 m long hexapole, which allows for a systematic study of the effect of parity conservation and breaking on the differential cross section. The collisionally excited NO molecules are detected using a resonant (1+1') REMPI ionization scheme in combination with the velocity- mapped, ion-imaging technique. The current experimental configuration minimizes the contribution of noncolliding NO molecules in other rotational states j, Omega, epsilon -that contaminates images- and allows for study of the collision process at an unprecedented level of detail. A simple method to correct ion images for collision-induced alignment is presented as well and its performance is demonstrated. The present results show a significant difference between differential cross sections for scattering into the upper and lower component of the Lambda-doublet of NO. This result cannot be due to the energy splitting between these components. (c) 2005 American Institute of Physics. C1 Vrije Univ Amsterdam, Dept Phys Chem, NL-1081 HV Amsterdam, Netherlands. Vrije Univ Amsterdam, Ctr Laser, NL-1081 HV Amsterdam, Netherlands. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. Univ Complutense, Fac Quim, Dept Quim Fis, E-28040 Madrid, Spain. RP Stolte, S (reprint author), Vrije Univ Amsterdam, Dept Phys Chem, De Boelelaan 1083, NL-1081 HV Amsterdam, Netherlands. EM stolte@few.vu.nl RI Wiskerke, Arjan/B-2715-2010; Klos, Jacek/A-6457-2008 OI Klos, Jacek/0000-0002-7407-303X NR 42 TC 54 Z9 55 U1 3 U2 14 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 DEC 8 PY 2005 VL 123 IS 22 AR 224305 DI 10.1063/1.2126969 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995RF UT WOS:000234120800017 PM 16375474 ER PT J AU Kerisit, S Rosso, KM AF Kerisit, S Rosso, KM TI Charge transfer in FeO: A combined molecular-dynamics and ab initio study SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FERRIC ELECTRON-TRANSFER; GAUSSIAN-BASIS SETS; IRON-OXIDES; ATOMISTIC SIMULATION; DOPED ALPHA-FE2O3; AQUEOUS-SOLUTION; LOWER MANTLE; ENERGY; HEMATITE; CONDUCTIVITY AB Molecular-dynamics simulations and ab initio electronic structure calculations were carried out to determine the rate of charge transfer in stoichiometric wustite (FeO). The charge transfer of interest occurs by II/III valence interchange between nearest-neighbor Fe atoms, with the Fe(III) constituting a "hole" electronic defect. There are two possible nearest-neighbor charge transfers in the FeO lattice, which occur between edge-sharing or corner-sharing FeO6 octahedra. Molecular-dynamics simulations predict charge-transfer rates of 3.7x10(11) and 1.9x10(9) s(-1) for the edge and corner transfers, respectively, in good agreement with those calculated using an ab initio cluster approach (1.6x10(11) and 8.0x10(8) s(-1), respectively). The calculated rates are also similar to those along the basal and c-axis directions in hematite (alpha-Fe2O3) determined previously. Therefore, as is the case for hematite, wustite is predicted to show anisotropic electrical conductivity. Our findings indicate that a rigid-ion model does not give acceptable results, thus showing the need to account for the change in polarizability of the system upon charge transfer. Our model achieves this by using a simple mechanical shell model. By calculating the electronic coupling matrix elements for many transition state configurations obtained from the molecular-dynamics simulations, we found evidence that the position of the bridging oxygen atoms can greatly affect the amount of electronic coupling between the donor and acceptor states. Finally, we address the effect of oxygen vacancies on the charge transfer. It was found that an oxygen vacancy not only creates a driving force for holes to transport away from the vacancy (or equivalently for electrons to diffuse toward the vacancy) but also lowers the free-energy barriers for charge transfer. In addition, the reorganization energy significantly differed from the nondefective case in a small radius around the defect. (c) 2005 American Institute of Physics. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Kerisit, S (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. EM sebastien.kerisit@pnl.gov NR 56 TC 24 Z9 25 U1 5 U2 39 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 DEC 8 PY 2005 VL 123 IS 22 AR 224712 DI 10.1063/1.2137319 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995RF UT WOS:000234120800043 PM 16375500 ER PT J AU Wang, X Rodriguez, JA Hanson, JC Perez, M Evans, J AF Wang, X Rodriguez, JA Hanson, JC Perez, M Evans, J TI In situ time-resolved characterization of Au-CeO2 and AuOx-CeO2 catalysts during the water-gas shift reaction: Presence of Au and O vacancies in the active phase SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CHEMICAL-PROPERTIES; SUPPORTED GOLD; CO OXIDATION; TITANIA; NANOPARTICLES; ADSORPTION; SURFACES; METAL; CERIA; SO2 AB Synchrotron-based in situ time-resolved x-ray diffraction and x-ray absorption spectroscopies were used to study the behavior of nanostructured {Au+AuOx}-CeO2 catalysts under the water-gas shift (WGS) reaction. At temperatures above 250 degrees C, a complete AuOx-> Au transformation was observed with high catalytic activity. Photoemission results for the oxidation and reduction of Au nanoparticles supported on rough ceria films or a CeO2(111) single crystal corroborate that cationic Audelta+ species cannot be the key sites responsible for the WGS activity at high temperatures. The rate determining steps for the WGS seem to occur at the gold-ceria interface, with the active sites involving small gold clusters (< 2 nm) and O vacancies. (c) 2005 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Cent Univ Venezuela, Fac Ciencias, Caracas 1020A, Venezuela. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov RI Hanson, jonathan/E-3517-2010 NR 35 TC 91 Z9 91 U1 3 U2 44 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 DEC 8 PY 2005 VL 123 IS 22 AR 221101 DI 10.1063/1.2136876 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 995RF UT WOS:000234120800001 PM 16375458 ER PT J AU Funston, A Kirby, JP Miller, JR Pospisil, L Fiedler, J Hromadova, M Gal, M Pecka, J Valasek, M Zawada, Z Rempala, P Michl, J AF Funston, A Kirby, JP Miller, JR Pospisil, L Fiedler, J Hromadova, M Gal, M Pecka, J Valasek, M Zawada, Z Rempala, P Michl, J TI One-electron reduction of an "extended viologen" p-phenylene-bis-4,4 '-(1-aryl-2,6-diphenylpyridinium) dication SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AROMATIC POLY(PYRIDINIUM SALT)S; METHYL VIOLOGEN; PULSE-RADIOLYSIS; AQUEOUS-SOLUTION; HEPTYL VIOLOGEN; DIFFERENTIAL OVERLAP; INTERMEDIATE NEGLECT; LIQUID ACETONITRILE; MOLECULAR WIRES; FREE-RADICALS AB One-electron reduction of the "extended viologen" dication I yields the red cation radical 2, characterized by strong near-IR absorption. It has been generated and studied by pulse radiolytic, electrochemical, redox titration, UV-visible, and electron paramagnetic resonance spectroscopic methods. All results are in agreement with a fully delocalized electronic structure for 2. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Acad Sci Czech Republ, J Heyrovsky Inst Phys Chem, CR-18223 Prague, Czech Republic. Charles Univ, Dept Organ Chem, Prague, Czech Republic. RP Michl, J (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. RI Hromadova, Magdalena/C-2369-2011; Funston, Alison/B-8817-2012; Pospisil, Lubomir/F-5195-2014; Fiedler, Jan/G-2180-2014; Valasek, Michal/C-7201-2015; Zawada, Zbigniew/M-6271-2016; Michl, Josef/G-9376-2014 OI Hromadova, Magdalena/0000-0002-3138-6917; Funston, Alison/0000-0002-4320-6434; Valasek, Michal/0000-0001-9382-6327; NR 53 TC 29 Z9 29 U1 0 U2 16 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 DEC 8 PY 2005 VL 109 IS 48 BP 10862 EP 10869 DI 10.1021/jp053556n PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 990RP UT WOS:000233761200008 PM 16331929 ER PT J AU Prall, BS Parkinson, DY Ishikawa, N Fleming, GR AF Prall, BS Parkinson, DY Ishikawa, N Fleming, GR TI Anti-correlated spectral motion in bisphthalocyanines: Evidence for vibrational modulation of electronic mixing SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PUMP-PROBE SPECTROSCOPY; PHTHALOCYANINE DIMERS; RHODOBACTER-SPHAEROIDES; REACTION CENTERS; COHERENT PHOTOCHEMISTRY; IMPULSIVE EXCITATION; RELAXATION DYNAMICS; PULSE; ABSORPTION; STATES AB We exploit a coherently excited nuclear wave packet to study nuclear motion modulation of electronic structure in a metal bridged phthalocyanine dimer, lutetium bisphthalocyanine, which displays two visible absorption bands. We find that the nuclear coordinate influences the energies of the underlying exciton and charge resonance states as well as their interaction; the interplay of the various couplings creates unusual anti-correlated spectral motion in the two bands. Excited state relaxation dynamics are the same regardless of which transition is pumped, with decay time constants of 1.5 and 11 ps. The dynamics are analyzed using a three-state kinetic model after relaxation from one or two additional states faster than the experimental time resolution of 50-100 fs. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Chuo Univ, Dept Appl Chem, Bunkyo Ku, Tokyo 1128551, Japan. RP Fleming, GR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM GRFleming@lbl.gov RI Parkinson, Dilworth/A-2974-2015 OI Parkinson, Dilworth/0000-0002-1817-0716 NR 46 TC 9 Z9 9 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 8 PY 2005 VL 109 IS 48 BP 10870 EP 10879 DI 10.1021/jp054225d PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 990RP UT WOS:000233761200009 PM 16331930 ER PT J AU Zhang, J Lima, FHB Shao, MH Sasaki, K Wang, JX Hanson, J Adzic, RR AF Zhang, J Lima, FHB Shao, MH Sasaki, K Wang, JX Hanson, J Adzic, RR TI Platinum monolayer on nonnoble metal-noble metal core-shell nanoparticle electrocatalysts for O-2 reduction SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID OXYGEN REDUCTION; SURFACES; DEPOSITION; CATALYSTS; PT(111); ALLOYS AB We synthesized a new class of O-2 electrocatalysts with a high activity and very low noble metal content. They consist of Pt inonolayers deposited on the surfaces of carbon-supported nonnoble metal-noble metal core-shell nanoparticles. These core-shell nanoparticles were formed by segregating the atoms of the noble metal on to the nanoparticles' surfaces at elevated temperatures. A Pt monolayer was deposited by galvanic displacement of a Cu monolayer deposited at underpotentials. The mass activity of all the three Pt monolayer electrocatalysts investigated, viz., Pt/AU/Ni, Pt/Pd/Co, and Pt/Pt/Co, is more than order of magnitude higher than that of a state-of-the-art commercial Pt/C electrocatalyst. Geometric effects in the Pt monolayer and the effects of PtOH coverage, revealed by electrochemical data, X-ray diffraction, and X-ray absorption spectroscopy data, appear to be the source of the enhanced catalytic activity. Our results demonstrated that high-activity electrocatalysts can be devised that contain only a fractional amount of Pt and a very small amount of another noble metal. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Adzic, RR (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM adzic@bnl.gov RI Hanson, jonathan/E-3517-2010; Lima, Fabio/E-7109-2012; Wang, Jia/B-6346-2011; OI Shao, Minhua/0000-0003-4496-0057 NR 20 TC 365 Z9 369 U1 35 U2 297 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 DEC 8 PY 2005 VL 109 IS 48 BP 22701 EP 22704 DI 10.1021/jp055634c PG 4 WC Chemistry, Physical SC Chemistry GA 990RQ UT WOS:000233761300001 PM 16853957 ER PT J AU Chialvo, AA Simonson, JM AF Chialvo, AA Simonson, JM TI Solvation behavior of short-chain polystyrene sulfonate in aqueous electrolyte solutions: A molecular dynamics study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHARGED POLYELECTROLYTE SOLUTIONS; FLEXIBLE POLYELECTROLYTES; MULTIVALENT SALTS; COEXISTENCE PROPERTIES; SUPERCRITICAL WATER; ATACTIC POLYSTYRENE; STATE CONDITIONS; SIMULATED WATER; WIDE RANGES; TEMPERATURE AB We analyze the solvation behavior of short-chain polystyrene sulfonate (PSS) in aqueous electrolyte Solutions by isothernal-isochoric molecular dynamics simulation to determine the solvation effects on the structure and conformation of the polyelectrolyte as a function of the aqueous environment. To that end, we study these aqueous systems including the explicit atomistic description of water, the PSS chain, and their interactions with all species in solution. In addition, we investigate the effect of the degree of sulfonation and its distribution along the PSS chain on the resulting conformation as well as solvation structure. Moreover, we assess the impact of added salts on the net charge of the PSS backbone, placing emphasis oil the valence of the counterion and the extent of the ion-pair formation between the sulfonate group and the counterions. Finally, we present evidence for the so-called like-charge attraction between sulfonate groups through the formation of counterion-mediated interchain sulfonate-sulfonate and water-mediated intrachain sulfonate-sulfonate bridges, as well as between unlike counterion-counterion interactions. C1 Oak Ridge Natl Lab, Div Chem Sci, Aqueous Chem & Geochem Grp, Oak Ridge, TN 37831 USA. RP Chialvo, AA (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Aqueous Chem & Geochem Grp, Oak Ridge, TN 37831 USA. EM chialvoaa@ornl.gov OI Chialvo, Ariel/0000-0002-6091-4563 NR 80 TC 26 Z9 26 U1 0 U2 22 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 DEC 8 PY 2005 VL 109 IS 48 BP 23031 EP 23042 DI 10.1021/jp053512e PG 12 WC Chemistry, Physical SC Chemistry GA 990RQ UT WOS:000233761300045 PM 16854001 ER PT J AU Tombola, F Pathak, MM Isacoff, EY AF Tombola, F Pathak, MM Isacoff, EY TI How far will you go to sense voltage? SO NEURON LA English DT Review ID DEPENDENT K+ CHANNEL; POTASSIUM CHANNEL; GATING-CHARGE; ION CHANNELS; PORE DOMAIN; S4 SEGMENT; ACTIVATION; DISPLACEMENT; MOVEMENT; MUTATIONS AB Despite tremendous progress in the study of voltage-gated channels, the molecular mechanism underlying voltage sensing has remained a matter of debate. We review five new studies that make major progress in the field. The studies employ a battery of distinct approaches that have the common aim of measuring the motion of the voltage sensor. We interpret the results in light of the recent crystal structure of the mammalian potassium channel Kv1.2. We focus on the transmembrane movement of the voltage sensor as a key element to the detection of membrane potential and to the control of channel gating. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Biophys Grad Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Padua, Dept Biomed Sci, I-35121 Padua, Italy. RP Isacoff, EY (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. EM ehud@berkeley.edu RI Tombola, Francesco/C-7311-2011 NR 29 TC 48 Z9 50 U1 2 U2 4 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0896-6273 J9 NEURON JI Neuron PD DEC 8 PY 2005 VL 48 IS 5 BP 719 EP 725 DI 10.1016/j.neuron.2005.11.024 PG 7 WC Neurosciences SC Neurosciences & Neurology GA 993BI UT WOS:000233927300011 PM 16337910 ER PT J AU Harris, JG Block, G AF Harris, JG Block, G TI The coupling of elastic, surface-wave modes by a slow, interfacial inclusion SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE elastic surface waves; coupled modes; interfacial inclusion ID PROPAGATION; GUIDES AB A layer of homogeneous, isotropic, elastic material overlays a substrate of similar material. The shear wavespeed within the layer is less than that of the substrate causing waves to be trapped within the layer. At the interface a long inclusion, that grows gradually until it reaches a constant thickness, is introduced. The inclusion is composed of a material whose shear wavespeed is less than that in the layer; it is described as slow. It is imagined that the lowest surface-wave mode of the structure is incident to the growing inclusion. Numerical calculations show that the growth of the slow inclusion brings the wavenumber of this lowest mode into ail interval where it is close to that of the second mode, thus exciting it. This process is repeated when the wavenumber of the second mode is brought close to that of the third. Within these intervals, energy is exchanged among the coupling modes. Outside of these localized intervals, the modes propagate independently of one another and their amplitudes vary such that the flux of energy in each mode is conserved; they are said to propagate adiabatically. Reflections are also excited, but are shown to be very small in magnitude. C1 Northwestern Univ, Ctr QEFP, Evanston, IL 60208 USA. Lawrence Livermore Natl Lab, Div Earth Sci, Livermore, CA 94550 USA. RP Harris, JG (reprint author), Northwestern Univ, Ctr QEFP, 2137 N Sheridan Rd, Evanston, IL 60208 USA. EM j-harris8@northwestern.edu NR 22 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SOCIETY PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD DEC 8 PY 2005 VL 461 IS 2064 BP 3765 EP 3783 DI 10.1098/rspa.2005.1541 PG 19 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 986CD UT WOS:000233425800005 ER PT J AU Zhou, Z Sutton, AP Dudarev, SL Jenkins, ML Kirk, MA AF Zhou, Z Sutton, AP Dudarev, SL Jenkins, ML Kirk, MA TI Simulations of electron elastic diffuse scattering patterns from individual nanometre-sized dislocation loops. I. Kinematical methodology SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE electron diffuse scattering; Huang diffuse scattering; dislocation loops; anisotropic elasticity ID X-RAY-SCATTERING; CUBIC-CRYSTALS; DEFECT STRUCTURES; POINT-DEFECTS; ATOMIC SIZE; DIFFRACTION; COPPER; CLUSTERS; ALLOYS AB A new experimental technique has recently been developed for characterizing small dislocation loops in the electron microscope by collecting elastic diffuse scattering patterns in the vicinity of Bragg reflections. In this paper we develop the theory and computational approaches for simulating such patterns. We apply the anisotropic elastic theory of displacement fields of planar dislocation loops of arbitrary shape to compute the distortion diffuse scattering amplitudes. To do this we extend methods based oil kinematical scattering theory, previously used to simulate X-ray and neutron diffuse scattering patterns. We demonstrate significant differences in the diffuse scattering patterns for the electron scattering case that arise from the small width of the incident electron beam, and under weak-beam conditions. We show that the method may be used to distinguish between individual, very small, vacancy or interstitial loops. We also show that elastic anisotropy may have an influence on elastic diffuse scattering patterns from loops, to an extent that varies with the magnitude of the deviation parameter. C1 Univ Oxford, Dept Math, Oxford OX1 3PH, England. Helsinki Univ Technol, Lab Computat Engn, Helsinki 02015, Finland. UKAEA Euratom Fus Assoc, Culham Sci Ctr, Theory & Modelling Dept, Abingdon OX14 3DB, Oxon, England. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Zhou, Z (reprint author), Univ Oxford, Dept Math, Parks Rd, Oxford OX1 3PH, England. EM a.sutton@imperial.ac.uk NR 28 TC 4 Z9 4 U1 1 U2 14 PU ROYAL SOCIETY PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD DEC 8 PY 2005 VL 461 IS 2064 BP 3935 EP 3953 DI 10.1098/rspa.2005.1542 PG 19 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 986CD UT WOS:000233425800014 ER PT J AU Huang, H Meakin, P Liu, MB AF Huang, H Meakin, P Liu, MB TI Computer simulation of two-phase immiscible fluid motion in unsaturated complex fractures using a volume of fluid method SO WATER RESOURCES RESEARCH LA English DT Article ID DISSIPATIVE PARTICLE DYNAMICS; LIQUID-PHASE STRUCTURE; ADVANCING INTERFACE; MOLECULAR-DYNAMICS; SOLUTE TRANSPORT; POROUS-MEDIA; GAS SYSTEMS; VADOSE ZONE; WATER-FLOW; CHALK AB [1] Complex fluid behavior in unsaturated fracture and fracture networks, such as film flow, the migration, fragmentation, and coalescence of droplets, and rivulet flow with or without meandering or pulsation, has been widely observed in laboratory experiments. In this study, a modified two-dimensional volume of fluid (VOF) method was used to simulate liquid motion in partially saturated fracture apertures under a variety of flow conditions. This modeling approach systematically incorporates the effects of inertial forces, viscosity, gravity acting on the fluid densities, fracture wall wetting, and the pressure drop across curved fluid-fluid interfaces due to surface tension. This allows us to obtain a better understanding of the fundamental physics governing unsaturated fluid flow in fracture apertures. The VOF method is able to handle the complex dynamics of fluid-fluid interfaces and free surfaces in unsaturated fractures by using a fixed Eulerian grid. Fragmentation and coalescence of the fluids are automatically handled without resorting to complex adaptive mesh refinement or interface repairing algorithms. The wetting of fracture walls was modeled by imposing contact angles near the contact lines ( contact points in two-dimensional simulations), and different contact angles were automatically chosen depending on whether the liquid interface is advancing, receding, or essentially stationary. The qualitative agreements between the numerical simulations and complex multiphase fluid dynamics reported in laboratory experiments clearly demonstrate the potential value of the VOF method for the mechanistically based modeling of immiscible liquid motion in unsaturated fracture networks. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Huang, H (reprint author), Idaho Natl Lab, POB 1625,MS 2025, Idaho Falls, ID 83415 USA. EM hai.huang@inl.gov NR 55 TC 24 Z9 24 U1 2 U2 29 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 DEC 8 PY 2005 VL 41 IS 12 AR W12413 DI 10.1029/2005WR004204 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 997NG UT WOS:000234251700002 ER PT J AU Perebeinos, V Newton, M AF Perebeinos, V Newton, M TI Electronic structure of S-C6H5 self-assembled monolayers on Cu(111) and Au(111) substrates SO CHEMICAL PHYSICS LA English DT Article DE self-assembled monolayer; density functional theory; lateral dispersion; work function; two photon photoemission; transport properties ID DENSITY-FUNCTIONAL THEORY; MOLECULAR ELECTRONICS; WIRES; APPROXIMATION; SIMULATIONS; CONDUCTANCE; INTENSITIES; INTERFACE; PARALLEL; GROWTH AB We use first principles density functional theory to calculate the electronic structure of the phenylthiolate (S-C6H5) self-assembled monolayer (SAM) on Cu(111) and Au(111) substrates. We find significant lateral dispersion of the SAM molecular states and note its possible implications for transport properties of the molecular wire array. We calculate the two photon photoemission spectra and the work function of the SAM on Cu(111) and compare them with the available experimental data. Our results are used to discuss assignments of the observed spectral data and yield predictions for new electronic states due to the monolayer not yet accessed experimentally. (c) 2005 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY USA. Brookhaven Natl Lab, Dept Chem, Upton, NY USA. RP Newton, M (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY USA. EM vperebe@us.ibm.com; nevvton@bnl.gov NR 24 TC 26 Z9 26 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD DEC 7 PY 2005 VL 319 IS 1-3 SI SI BP 159 EP 166 DI 10.1016/j.chemphys.2005.04.041 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 993LL UT WOS:000233955500015 ER PT J AU Matloka, K Gelis, A Regalbuto, M Vandegrift, G Scott, MJ AF Matloka, K Gelis, A Regalbuto, M Vandegrift, G Scott, MJ TI Highly efficient binding of trivalent f-elements from acidic media with a C-3-symmetric tripodal ligand containing diglycolamide arms SO DALTON TRANSACTIONS LA English DT Article ID TRIPHENOXYMETHANE PLATFORM; SOLVENT-EXTRACTION; MOLECULAR-DYNAMICS; LANTHANIDE IONS; WATER-EXCHANGE; DIAMIDES; CHEMISTRY; ACTINIDES AB Tripodal chelates bearing three diglycolamide units precisely arranged on a triphenoxymethane platform were synthesized to mimic the preferred tricapped trigonal prismatic geometry favored by lanthanides with oxygen donor ligands, and the ligand binds heavier lanthanides very efficiently in acidic media. C1 Univ Florida, Gainesville, FL 32611 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Scott, MJ (reprint author), Univ Florida, POB 117200, Gainesville, FL 32611 USA. EM mjscott@chem.ufl.edu RI Scott, Michael/B-7859-2013 NR 26 TC 42 Z9 42 U1 3 U2 18 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1477-9226 J9 DALTON T JI Dalton Trans. PD DEC 7 PY 2005 IS 23 BP 3719 EP 3721 DI 10.1039/b513745d PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 990LJ UT WOS:000233744200003 PM 16471051 ER PT J AU Bhusarapu, S Al-Dahhan, MH Dudukovic, MP Trujillo, S O'Hern, TJ AF Bhusarapu, S Al-Dahhan, MH Dudukovic, MP Trujillo, S O'Hern, TJ TI Experimental study of the solids velocity field in gas-solid risers SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article; Proceedings Paper CT Joint 5th International Symposium on Catalysis in Multiphase Reactors/4th International Symposium on Multifunctional Reactors CY JUN 15-18, 2005 CL Portoroz-Portorose, SLOVENIA ID CIRCULATING FLUIDIZED-BED; PARTICLE TRACKING; FLOW; HYDRODYNAMICS; PIPE; FLUX AB Solids flow dynamics in gas-solid risers is inherently complex. Model refinement through experimental validation requires the acquisition of detailed nonintrusive measurements. In this study, noninvasive computer-automated radioactive particle tracking (CARPT) is employed to visualize and quantify in a three-dimensional domain the solids dynamics and mixing in gas-solid risers. This technique has the added advantage that, along with the derived Eulerian solids flow field (time-average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy), it also provides directly the Lagrangian description of the solids motion. The solids velocity field data are obtained in two different risers at low and high solids fluxes at varying superficial gas velocity to span both the fast-fluidized (FF) and dilute phase transport (DPT) regimes. The effect of operating conditions on solids flow and mixing is studied. Comparative analysis of the results is presented to provide insights into the complex solids flow patterns characteristic of gas-solid risers. C1 Washington Univ, Dept Chem Engn, Chem React Engn Lab, St Louis, MO 63130 USA. Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. RP Dudukovic, MP (reprint author), Washington Univ, Dept Chem Engn, Chem React Engn Lab, Campus Box 1198,1 Brookings Dr, St Louis, MO 63130 USA. EM dudu@wustl.edu NR 25 TC 14 Z9 16 U1 1 U2 15 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 DEC 7 PY 2005 VL 44 IS 25 BP 9739 EP 9749 DI 10.1021/ie050297f PG 11 WC Engineering, Chemical SC Engineering GA 989PF UT WOS:000233685400051 ER PT J AU Pasyanos, ME AF Pasyanos, ME TI A variable resolution surface wave dispersion study of Eurasia, North Africa, and surrounding regions SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID UPPER-MANTLE STRUCTURE; HEAT-FLOW; CONTINENTAL-CRUST; OCEAN-FLOOR; TOMOGRAPHY; LITHOSPHERE; BENEATH; MODEL; EVOLUTION; THICKNESS AB [1] This paper presents the results of a large-scale study of surface wave dispersion performed across Eurasia and North Africa. Improvements were made to previous surface wave work by enlarging the study region, increasing path density, improving spatial resolution, and expanding the period range. This study expands the coverage area northward and eastward relative to a previous dispersion analysis, which covered only North Africa and the Middle East. We have significantly increased the number of seismograms examined and group velocity measurements made. We have now made good quality dispersion measurements for about 30,000 Rayleigh wave and 20,000 Love wave paths and have incorporated measurements from several other researchers into the study. We have improved the inversion from the previous study by adopting a variable smoothness with the conjugate gradient method for the group velocity tomography. This technique produces higher-resolution models where the concentration of data allows it without producing artifacts. The current results include both Love and Rayleigh wave inversions across the region for periods from 7 to 100 s on a 1 degrees X 1 degrees grid and at resolutions approaching 1 degrees under some conditions. Short-period group velocities are sensitive to slow velocities associated with large sedimentary features such as the Caspian Sea, West Siberian Platform, Mediterranean Sea, Bay of Bengal, Tarim Basin, and Persian Gulf. Intermediate periods are sensitive to differences in crustal thickness, such as those between oceanic and continental crust or along orogenic zones and continental plateaus. At longer periods, fast velocities are consistently found beneath cratons, while slow upper mantle velocities occur along rift systems, subduction zones, and collision zones such as the Tethys Belt. We have compared the group velocities at various periods with features such as sediment thickness, topographic height, crustal thickness, proximity to plate boundaries, lithospheric age, and lithospheric thickness, and we find significant correlations. We have developed an empirical relationship between long-period group velocity and lithospheric thickness that works well for both oceanic and continental lithosphere. We do not find any similar correlation between the longest-period surface waves and hot spots. C1 Lawrence Livermore Natl Lab, Div Earth Sci, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, Div Earth Sci, POB 808,L-205, Livermore, CA 94551 USA. EM pasyanos1@llnl.gov RI Pasyanos, Michael/C-3125-2013 NR 44 TC 49 Z9 50 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 7 PY 2005 VL 110 IS B12 AR B12301 DI 10.1029/2005JB003749 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 997MO UT WOS:000234249800004 ER PT J AU Chiou, JW Tsai, HM Pao, CW Dong, CL Chang, CL Chien, FZ Pong, WF Tsai, MH Shi, SC Chen, CF Chen, LC Chen, KH Hong, IH Chen, CH Lin, HJ Guo, JH AF Chiou, JW Tsai, HM Pao, CW Dong, CL Chang, CL Chien, FZ Pong, WF Tsai, MH Shi, SC Chen, CF Chen, LC Chen, KH Hong, IH Chen, CH Lin, HJ Guo, JH TI Comparison of the electronic structures of AIN nanotips grown on p- and n-type Si substrates SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID FIELD-EMISSION; AFFINITY; GAN; SPECTROSCOPY; SURFACES; VALENCE; STATES; FILMS AB At and N K-edge x-ray absorption near-edge structure (XANES), scanning photoelectron microscopy (SPEM) and x-ray emission measurements were performed on AIN nanotips grown on p- and n-type Si substrates (p-AIN and n-AIN). Features and intensities in the Al and N K-edge XANES spectra of these AIN nanotips overall are similar. In contrast, the intensities of the valence-band SPEM spectra of p-AIN are apparently larger than those of n-AIN, which indicates that the valence-band density of states of p-AIN exceeds that of n-AIN. This result may be related to the observed enhancement of field-emission intensity of AIN nanotips grown on the p-type Si substrate. C1 Tamkang Univ, Dept Phys, Taipei 251, Taiwan. Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 804, Taiwan. Natl Chiao Tung Univ, Dept Mat Sci & Engn, Hsinchu 300, Taiwan. Natl Taiwan Univ, Ctr Condensed Matter Sci, Taipei 106, Taiwan. Acad Sinica, Inst Atom & Mol Sci, Taipei 106, Taiwan. Natl Synchrotron Radiat Res Ctr, Hsinchu 300, Taiwan. Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Pong, WF (reprint author), Tamkang Univ, Dept Phys, Taipei 251, Taiwan. EM wfpong@mail.tku.edu.tw RI Chen, Cheng-Hsuan/F-7933-2012; Chen, Kuei-Hsien/F-7924-2012; Chen, Li-Chyong/B-1705-2015; OI Chen, Li-Chyong/0000-0001-6373-7729; Chang, Ching-Lin/0000-0001-8547-371X; Shi, Shih-Chen/0000-0002-4163-2552 NR 18 TC 5 Z9 5 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD DEC 7 PY 2005 VL 17 IS 48 BP 7523 EP 7530 DI 10.1088/0953-8984/17/48/006 PG 8 WC Physics, Condensed Matter SC Physics GA 997SR UT WOS:000234268600008 ER PT J AU Ball, JA Pirzada, M Grimes, RW Zacate, MO Price, DW Uberuaga, BP AF Ball, JA Pirzada, M Grimes, RW Zacate, MO Price, DW Uberuaga, BP TI Predicting lattice parameter as a function of cation disorder in MgAl2O4 spinel SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID MAGNESIUM ALUMINATE SPINEL; NEUTRON-IRRADIATED SPINEL; MONTE-CARLO; CRYSTALS; SIMULATION; ELECTRON; INVERSION; NMR AB In the perfect magnesium aluminate spinel structure all the tetrahedral sites are occupied by Mg2+ ions, while Al3+ ions occupy all the octahedral sites. Real MgAl2O4, however, exhibits cation disorder (inversion), so that some Mg2+, ions reside in octahedral sites with an equal number of Al3+ ions in tetrahedral sites. Atomistic simulation was used to correlate the degree of inversion with changes in lattice parameter. Results from several approaches, including a combined energy minimization-Monte Carlo technique (CEMMC), are compared with available experimental data. These show that the mean field method is not useful, while the defect volume approach can yield predictions that are useful in interpreting the CEMMC results, which agree most closely with experiment. C1 Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. No Kentucky Univ, Dept Phys & Geol, Highland Hts, KY 41099 USA. AWE, Reading RG7 4PR, Berks, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ball, JA (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. EM r.grimes@imperial.ac.uk RI Price, David/B-5017-2013 NR 38 TC 28 Z9 28 U1 1 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD DEC 7 PY 2005 VL 17 IS 48 BP 7621 EP 7631 DI 10.1088/0953-8984/17/48/014 PG 11 WC Physics, Condensed Matter SC Physics GA 997SR UT WOS:000234268600016 ER PT J AU Rosen, J Anders, A AF Rosen, J Anders, A TI Time and material dependence of the voltage noise generated by cathodic vacuum arcs SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID RANDOM-WALK; SPOTS; PLASMA; PARAMETERS; INITIATION; LASER AB The high frequency fluctuations of the burning voltage of cathodic vacuum arcs have been investigated in order to extract information on cathode processes, especially concerning evolution in time after arc ignition. Eight cathode materials (W, Ta, Hf, Ti, Ni, An, Sn, Bi) were selected covering a wide range of cohesive energy. The voltage noise was recorded using both a broad-band voltage divider and an attenuator connected to a fast oscilloscope (limits 1 GHz analog and 5 GS s(-1) digital). Fast Fourier transform revealed a power spectrum that is linear in log-log presentation, with a slope of 1/f(2), where f is the frequency (brown noise). The amplitude of the spectral power of the voltage noise was found to scale with the cohesive energy, in agreement with earlier measurements at lower resolution. These basic results do not depend on the time after arc initiation. However, lower arc current in the beginning of the pulse shows greater voltage noise, suggesting an inverse relation between the noise amplitude and number of emission sites (cathode spot fragments). C1 Rhein Westfal TH Aachen, D-52056 Aachen, Germany. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Rosen, J (reprint author), Rhein Westfal TH Aachen, D-52056 Aachen, Germany. RI Rosen, Johanna/M-9284-2014; Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 26 TC 12 Z9 13 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD DEC 7 PY 2005 VL 38 IS 23 BP 4184 EP 4190 DI 10.1088/0022-3727/38/23/007 PG 7 WC Physics, Applied SC Physics GA 996OH UT WOS:000234183000008 ER PT J AU Hay, BP Oliferenko, AA Uddin, J Zhang, CG Firman, TK AF Hay, BP Oliferenko, AA Uddin, J Zhang, CG Firman, TK TI Search for improved host architectures: Application of de novo structure-based design and high-throughput screening methods to identify optimal building blocks for multidentate ethers SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID STRUCTURE-STABILITY RELATIONSHIP; CATION SOLVENT-EXTRACTION; ALKALINE-EARTH CATIONS; METAL-ION RECOGNITION; MM3 FORCE-FIELD; MACROCYCLE INTERACTION; MOLECULAR-MECHANICS; SELECTIVE LIGANDS; RATIONAL DESIGN; CROWN-ETHERS AB This paper presents a computational approach to the deliberate design of improved host architectures. The approach, which involves the use of computer-aided design software, is illustrated by application to cation hosts containing multiple aliphatic ether oxygen binding sites. De novo molecule building software, HostDesigner, is interfaced with molecular mechanics software, GMMX, providing a tool for generating and screening millions of potential bidentate building block structures. Enhanced cation binding affinity can be achieved when highly organized building blocks are used to construct macrocyclic hosts. C1 Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Div Chem Sci, POB 999, Richland, WA 99352 USA. EM ben.hay@pnl.gov NR 58 TC 36 Z9 36 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 DEC 7 PY 2005 VL 127 IS 48 BP 17043 EP 17053 DI 10.1021/ja055169x PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 990QV UT WOS:000233759200055 PM 16316251 ER PT J AU Xiong, YJ McLellan, JM Chen, JY Yin, YD Li, ZY Xia, YN AF Xiong, YJ McLellan, JM Chen, JY Yin, YD Li, ZY Xia, YN TI Kinetically controlled synthesis of triangular and hexagonal nanoplates of palladium and their SPR/SERS properties SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ENHANCED RAMAN-SPECTROSCOPY; SHAPE-CONTROLLED SYNTHESIS; COUPLING REACTIONS; METAL NANOPARTICLES; OPTICAL-PROPERTIES; GOLD NANOCRYSTALS; SILVER NANODISKS; POLYOL SYNTHESIS; PLATINUM NANOPARTICLES; ARBITRARY SHAPES AB The rapid reduction of Na2PdCl4 by ethylene glycol in the presence of poly(vinyl pyrrolidone) (PVP) has recently been demonstrated as a convenient method of generating Pd cubooctahedra and twinned nanoparticles. Here we describe a new procedure where Pd triangular or hexagonal nanoplates could be selectively synthesized by manipulating the reduction kinetics of the polyol process. More specifically, the reduction rate was substantially reduced through the introduction of Fe(Ill) species and the O-2/Cl- pair, two wet etchants for Pd(0). The etching power of the O-2/Cl- pair could be further enhanced by adding an acid to lower the pH of the reaction solution. Unlike the previously reported synthesis of Ag and Au nanoplates, light was found to have no indispensable role in the formation of Pd nanoplates. Both triangular and hexagonal nanoplates of Pd exhibited surface plasmon resonance (SPR) peaks in the visible region, and their positions matched with the results of discrete dipole approximation (DDA) calculation. Thanks to their sharp corners and edges, these Pd nanoplates could serve as active substrates for surface-enhanced Raman scattering (SERS). C1 Univ Washington, Dept Chem, Seattle, WA 98195 USA. Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China. RP Xia, YN (reprint author), Univ Washington, Dept Chem, Seattle, WA 98195 USA. EM xia@chem.washington.edu RI Yin, Yadong/D-5987-2011; Xiong, Yujie/G-3203-2010; Xia, Younan/E-8499-2011; Chen, Jingyi/E-7168-2010 OI Yin, Yadong/0000-0003-0218-3042; Chen, Jingyi/0000-0003-0012-9640 NR 84 TC 452 Z9 459 U1 33 U2 422 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 DEC 7 PY 2005 VL 127 IS 48 BP 17118 EP 17127 DI 10.1021/ja056498s PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 990QV UT WOS:000233759200064 PM 16316260 ER PT J AU Torres, DF Domingo-Santamaria, E AF Torres, DF Domingo-Santamaria, E TI Some comments on the high energy emission from regions of star formation beyond the galaxy SO MODERN PHYSICS LETTERS A LA English DT Review DE starbursts; starburst (individual : NGC253); ultra-luminous galaxies (individual : Arp 220); star formation; gamma-rays : observations; gamma-rays : theory ID GAMMA-RAY EMISSION; LUMINOUS INFRARED GALAXIES; LARGE MAGELLANIC CLOUD; NGC 253; COSMIC-RAYS; SUPERNOVA-REMNANTS; MOLECULAR GAS; MILKY-WAY; ULTRALUMINOUS GALAXIES; RADIAL-DISTRIBUTION AB Regions that currently are or have been subject to a strong process of star formation are good candidates to be intense gamma-ray and neutrino emitters. They may even perhaps be sites where ultra high energy cosmic rays are produced. Outside the Galaxy, the more powerful sites of star formation are found within very active galaxies such as starbursts (SGs) and Luminous or Ultra-Luminous Infrared Galaxies (LIR.Cs or ULIRGs). Some general characteristic of these objects are herein reviewed from the point of view of their possible status as high energy emitters. Revised estimations of the high energy gamma-ray yield of Arp 220 are presented. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. IFAE, Bellaterra 08193, Spain. RP Torres, DF (reprint author), Fac Ciencias Torre C5, Inst Ciencias Espacio, Campus UAB,2A Planta, Barcelona 08193, Spain. EM domingo@ifae.es RI Torres, Diego/O-9422-2016 OI Torres, Diego/0000-0002-1522-9065 NR 61 TC 4 Z9 4 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD DEC 7 PY 2005 VL 20 IS 37 BP 2827 EP 2843 DI 10.1142/S0217732305018748 PG 17 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA 989UJ UT WOS:000233699100001 ER PT J AU Dabbs, DM Ramachandran, U Lu, S Liu, J Wang, LQ Aksay, IA AF Dabbs, DM Ramachandran, U Lu, S Liu, J Wang, LQ Aksay, IA TI Inhibition of aluminum oxyhydroxide precipitation with citric acid SO LANGMUIR LA English DT Article ID LIGAND-PROMOTED DISSOLUTION; AL-27 NMR-SPECTROSCOPY; COORDINATION CHEMISTRY; WATER INTERFACE; ORGANIC-ACIDS; KINETICS; SUSPENSIONS; ADSORPTION; STABILITY; COMPLEXES AB Citric acid has been shown to act as an agent for increasing the solubility of aluminum oxyhydroxides in aqueous solutions of high (>2.47 mol/mol) hydroxide-to-aluminum ratios. Conversely, citric acid also colloidally stabilizes particles in aqueous suspensions of aluminum-containing particles. Solutions of aluminum chloride, with and without citric acid added, were titrated with NaOH(aq), The presence and size of particles were determined using quasi-elastic light scattering. In solutions that contained no citric acid, particles formed instantaneously when NaOH(aq) was added but these were observed to rapidly diminish in size, disappearing at OH/Al ratios below 2.5 mol/mol. When the OH/Al ratio was raised beyond 2.5 by adding more NaOH(aq), suspensions of colloidally stable particles formed. Large polycations containing 13 aluminum atoms were detected by Al-27 solution NMR in citric-acid-free solutions with OH/Al ratios slightly lower than 2.5. In comparison, adding citric acid to solutions of aluminum chloride inhibited the formation of large aluminum-containing polycations. The absence of the polycations prevents or retards the subsequent formation of particles, indicating that the polycations, when present, act as seeds to the formation of new particles. Particles did not form in solutions with a citric acid/aluminum ratio of 0.8 until sufficient NaOH(aq) was added to raise the OH/Al ratio to 3.29. By comparison, lower amounts of citric acid did not prevent particles from forming but did retard the rate of growth. C1 Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Aksay, IA (reprint author), Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. EM iaksay@princeton.edu RI Dabbs, Daniel/B-9276-2008; Aksay, Ilhan/B-9281-2008 NR 29 TC 9 Z9 9 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 6 PY 2005 VL 21 IS 25 BP 11690 EP 11695 DI 10.1021/la050822f PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 990GC UT WOS:000233730200026 PM 16316102 ER PT J AU Lorenz, CD Chandross, M Grest, GS Stevens, MJ Webb, EB AF Lorenz, CD Chandross, M Grest, GS Stevens, MJ Webb, EB TI Tribological properties of alkylsilane self-assembled monolayers SO LANGMUIR LA English DT Article ID MOLECULAR-DYNAMICS; FORCE-FIELD; AB-INITIO; MICROELECTROMECHANICAL SYSTEMS; SILICON; MEMS; ADHESION; LUBRICATION; DISULFIDES; MECHANISMS AB In this study, we perform molecular dynamics simulations of adhesive contact and friction between alkylsilane Si(OH)(3)(CX2)(10)CX3 and alkoxylsilane Si(OH)(2)(CX2)(10)CX3 (where X = [I or F) self-assembled monolayers (SAMs) on an amorphous silica substrate. The alkylsilane SAMs are primarily hydrogen-bonded or physisorbed to the surface. The alkoxylsilane SAMs are covalently bonded or chemisorbed to the surface. Previously, we studied the chemisorbed systems. In this work, we study the physisorbed systems and compare the tribological properties with the chemisorbod systems. Furthermore. we examine how water at the interface of the SAMs and substrate affects the tribological properties of the physisorbed systems. When less than a third of a monolayer is present, very little difference in the microscopic friction coefficient mu or shear stresses is observed. For increasing amounts of water, the values of mu and the shear stresses decrease; this effect is somewhat more pronounced for fluorocarbon alkylsilane SAMs than for the hydrocarbon SAMs. The observed decrease in friction is a consequence of it slip plane that occurs in the water as the amount of water is increased. We studied the frictional behavior using relative shear velocities ranging from v = 2 cm/s to 2 nits. Similar to previously reported results for alkoxylsilane SAMs, the values of the measured stress and mu for the alkylsilane SAM systems decrease monotonically with v. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lorenz, CD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM edloren@sandia.gov RI Lorenz, Christian/A-6996-2017 OI Lorenz, Christian/0000-0003-1028-4804 NR 34 TC 27 Z9 29 U1 2 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 6 PY 2005 VL 21 IS 25 BP 11744 EP 11748 DI 10.1021/la051741m PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 990GC UT WOS:000233730200033 PM 16316109 ER PT J AU Li, ZJ Yan, WF Dai, S AF Li, ZJ Yan, WF Dai, S TI Surface functionalization of ordered mesoporous carbons - A comparative study SO LANGMUIR LA English DT Article ID SYNTHETIC MESOPHASE PITCH; MOLECULAR-SIEVES; MECHANISTIC IMPLICATIONS; OXIDATIVE STABILIZATION; NANOPOROUS CARBONS; TEMPLATE SYNTHESIS; NANOTUBES; SILICA; ADSORPTION; CARBONIZATION AB Hexagonalily structured mesoporous carbons C 15 and CMK-5 and cubically structured carbon C48 were synthesized using ordered silica SBA-15 and MCM-48 as templates and carbon precursors of different structures. The surfaces of these ordered carbons were chemically functionalized by employing an approach, in which the selected diazonium compounds were in situ generated and reacted with the carbon frameworks of the mesoporous carbons. The aromatic organic molecules containing chlorine, ester, and alkyl groups were covalently attached to the surface of these ordered mesoporous carbons. The presence of functional groups on the modified carbons was confirmed with Fourier transform infrared spectroscopy, thermo-gravimetric analysis, and nitrogen adsorption. The BET-specific surface area and the pore width of ordered carbons were significantly reduced, whereas the primary structure of these ordered carbons and their unit cells were intact. Basically, the density of grafted functional groups is related to the specific surface area of the sample, particularly the surface area of mesopores. The surface functionalization reaction takes place only on the external surface of carbon C 15, while it occurs on both of the internal and external surface of CMK-5 carbon with the nanopipe structure. The presence of the micropores in CMK-5 carbon should be responsible for its lower grafting density because the small micropores are inaccessible in the reaction. It was also proposed that the preferred adsorption/reaction in C48 may be related to the observed unsymmetrical degradation of the XRD patterns for the functionalized C48 samples. The chemical modification process considerably reduced the primary mesopores in these ordered carbons by similar to 1-1.5 nm, affording carbons with micropores in the cases of C 15 and C48, and mixed micropores and small mesopores in the case of CMK-5. A grafting density of similar to 0.9-1.5 mu mol/m(2) was achieved under current research. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Dai, S (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. EM dais@ornl.gov RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 45 TC 58 Z9 60 U1 7 U2 119 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD DEC 6 PY 2005 VL 21 IS 25 BP 11999 EP 12006 DI 10.1021/la051608u PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 990GC UT WOS:000233730200069 PM 16316145 ER PT J AU Levy, O Ptacin, JL Pease, PJ Gore, J Eisen, MB Bustamante, C Cozzarelli, NR AF Levy, O Ptacin, JL Pease, PJ Gore, J Eisen, MB Bustamante, C Cozzarelli, NR TI Identification of oligonucleotide sequences that direct the movement of the Escherichia coli FtsK translocase SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE dimer resolution; sequence-directed translocases; skewed sequences; triplex displacement; single-molecule ID COMPLETE GENOME SEQUENCE; CHROMOSOME DIMER RESOLUTION; CELL-DIVISION; DNA; RECOMBINATION; TERMINUS; SITE; PROTEIN; REPLICATION; POLARITY AB FtsK from Escherichia coli is a fast and sequence-directed DNA translocase with roles in chromosome dimer resolution, segregation, and decatenation. From the movement of single FtsK particles on defined DNA substrates and an analysis of skewed DNA sequences in bacteria, we identify GNGNAGGG, its complement, or both as a sequence motif that controls translocation directionality. GNGNAGGG is skewed so that it is predominantly on the leading strand of chromosomal replication. Translocation across this octamer from the 3' side of the G-rich strand causes FtsK to pause, turn around, and translocate in the opposite direction. Only 39 4% of the encounters between FtsK and the octamer result in a turnaround, congruent with our optimum turnaround probability prediction of 30%. The probability that the observed skew of GNGNAGGG within 1 megabase of dif occurred by chance in E. coli is 1.7 x 10(-57), and similarly dramatic skews are found in the five other bacterial genomes we examined. The fact that FtsK acts only in the terminus region and the octamer skew extends from origin to terminus implies that this skew is also important in other basic cellular processes that are common among bacteria. Finally, we show that the FtsK translocase is a powerful motor that is able to displace a triplex-forming oligo from a DNA substrate. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Biophys Grad Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Genom Div, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. RP Cozzarelli, NR (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 16 Barker Hall, Berkeley, CA 94720 USA. EM ncozzare@berkeley.edu OI Eisen, Michael/0000-0002-7528-738X FU NIGMS NIH HHS [R37 GM032543, GM31655, GM31657, GM32543, R01 GM031655, R01 GM031657, R01 GM032543, R37 GM031657] NR 29 TC 83 Z9 84 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 6 PY 2005 VL 102 IS 49 BP 17618 EP 17623 DI 10.1073/pnas.058932102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 991XU UT WOS:000233849000016 PM 16301526 ER PT J AU Lee, D Lee, J Kim, J Kim, J Na, HB Kim, B Shin, CH Kwak, JH Dohnalkova, A Grate, JW Hyeon, T Kim, HS AF Lee, D Lee, J Kim, J Kim, J Na, HB Kim, B Shin, CH Kwak, JH Dohnalkova, A Grate, JW Hyeon, T Kim, HS TI Simple fabrication of a highly sensitive and fast glucose biosensor using enzymes immobilized in mesocellular carbon foam SO ADVANCED MATERIALS LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES; CHEMICAL-VAPOR-DEPOSITION; SILICA MATERIALS; ALUMINUM INCORPORATION; ULTRALARGE MESOPORES; CATALYTIC ACTIVITY; NANOPOROUS CARBON; BOTTLE SYNTHESIS; CYTOCHROME-C; LOW-COST AB Glucose oxidase immobilized in mesocellular carbon foam results in a highly sensitive and fast glucose biosensor. The structure of the mesocellular foam (see Figure), with a combination of mesopores containing the glucose oxidase (GOx) enzymes and micropores and transport channels, results in high enzyme loading and low mass-transfer limitations, producing higher catalytic activity and sensitivity than polymer-matrix-based GOx glucose sensors. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Seoul Natl Univ, Natl Creat Res Initiat Ctr Oxide Nanocrystalline, Seoul 151744, South Korea. Seoul Natl Univ, Sch Chem & Biol Engn, Seoul 151744, South Korea. Korea Adv Inst Sci & Technol, Dept Sci Biol, Taejon 305701, South Korea. Chungbuk Natl Univ, Dept Chem Engn, Chonju 360763, Chungbuk, South Korea. RP Kim, J (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. EM jungbae.Kim@pnl.gov; thyeon@plaza.snu.ac.kr; hskim76@kaist.ac.kr RI Kim, Hak-Sung/C-1929-2011; Hyeon, Taeghwan/J-5315-2012; Kwak, Ja Hun/J-4894-2014; Lee, Jinwoo/G-3330-2016; Lee, Junyoung/D-5463-2012 OI Lee, Jinwoo/0000-0001-6347-0446; Lee, Junyoung/0000-0001-6689-2759 NR 50 TC 155 Z9 156 U1 4 U2 77 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD DEC 5 PY 2005 VL 17 IS 23 BP 2828 EP + DI 10.1002/adma.200500793 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 993KB UT WOS:000233951900011 ER PT J AU Li, ZY Yuan, J Chen, Y Palmer, RE Wilcoxon, JP AF Li, ZY Yuan, J Chen, Y Palmer, RE Wilcoxon, JP TI Local three-dimensional visualization of nanoparticle assemblies SO ADVANCED MATERIALS LA English DT Article ID GOLD CLUSTERS; Z-CONTRAST; SUPERLATTICES; NANOCRYSTALS; MICROSCOPY AB High-angle annular dark-field (HAADF) imaging technique in the scanning transmission electron microscope has been exploited to study self-assembled multilayer structures of Au/Ag nanoparticles. The HAADF image intensity depends monotonically on the mass and thickness of the sample. Various film thickness between one to four monolayers can be easily distinguished by evaluating the contrast (see Figure). C1 Univ Birmingham, Nanoscale Phys Res Lab, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. Tsing Hua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. Sandia Natl Labs, Nanostruct & Adv Mat Chem, Dept 1122, Albuquerque, NM 87185 USA. RP Li, ZY (reprint author), Univ Birmingham, Nanoscale Phys Res Lab, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. EM ziyouli@nprl.ph.bham.ac.uk RI Palmer, Richard/A-5366-2008; Yuan, Jun/J-2577-2012; Chen, Yu/B-8858-2013 OI Palmer, Richard/0000-0001-8728-8083; Yuan, Jun/0000-0001-5833-4570; NR 22 TC 13 Z9 13 U1 0 U2 11 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD DEC 5 PY 2005 VL 17 IS 23 BP 2885 EP + DI 10.1002/adma.200500977 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 993KB UT WOS:000233951900025 ER PT J AU Centoni, SA Sadigh, B Gilmer, GH de la Rubia, TD Musgrave, CB AF Centoni, SA Sadigh, B Gilmer, GH de la Rubia, TD Musgrave, CB TI First-principles calculation of free Si(100) surface impurity enrichment SO APPLIED PHYSICS LETTERS LA English DT Article ID TOTAL-ENERGY CALCULATIONS; AB-INITIO CALCULATIONS; WAVE BASIS-SET; ENHANCED SOLUBILITY; C-INCORPORATION; RECONSTRUCTION; SEMICONDUCTORS; SEGREGATION; ENERGETICS; SI(001) AB Low-temperature crystal growth techniques can deposit silicon films with impurity concentration orders of magnitude above their bulk solubility limits. First-principles calculations were performed of the energies (relative to the bulk) of single substitutional carbon, germanium, boron, and arsenic atoms at several positions within a thin (100) slab of silicon reconstructed as c(4x2). The energies of these impurities were found to be at least 0.2 eV lower than in the bulk, corresponding to surface enrichments of 1000 or greater at a temperature of 500 degrees C. General trends can be explained using the concepts of hybridization energy and lone pairs. The large surface reconstruction strain gives rise to this complex potential energy surface, and favors long-ranged order among impurities near the surface. As a result, we expect a complex dependence of trapped impurity concentrations on growth rate and temperature, with a high sensitivity to these parameters when the exchange rate of the impurity with neigboring sites is comparable to the monolayer deposition rate. (c) 2005 Americian Institute of Physics. C1 San Jose State Univ, Dept Mat Engn, San Jose, CA 95192 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. RP San Jose State Univ, Dept Mat Engn, San Jose, CA 95192 USA. EM scentoni@email.sjsu.edu NR 20 TC 4 Z9 4 U1 0 U2 3 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 DEC 5 PY 2005 VL 87 IS 23 AR 232101 DI 10.1063/1.2138811 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200039 ER PT J AU Choi, IH Yu, PY AF Choi, IH Yu, PY TI Properties of a CuAu phase of AgGaSe2 grown on [100] GaAs substrate SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICAL-PROPERTIES AB Recently, it has been suggested theoretically [A. Janotti and S.-H. Wei, Appl. Phys. Lett. 81, 3957 (2002)] that, if AgGaSe2 with the CuAu structure can be grown epitaxially on ZnSe, it will be an excellent source for spin-polarized electrons. Here we report the growth and properties of epitaxial films of AgGaSe2 with the CuAu structure on (100) GaAs substrates and compared them with those of chalcopyrite AgGaSe2. (c) 2005 Americian Institute of Physics. C1 Chung Ang Univ, Dept Phys, Seoul 156756, South Korea. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Chung Ang Univ, Dept Phys, Seoul 156756, South Korea. EM pyyu@lbl.gov NR 8 TC 9 Z9 9 U1 0 U2 2 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 DEC 5 PY 2005 VL 87 IS 23 AR 231909 DI 10.1063/1.2140083 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200031 ER PT J AU Coleman, VA Tan, HH Jagadish, C Kucheyev, SO Zou, J AF Coleman, VA Tan, HH Jagadish, C Kucheyev, SO Zou, J TI Thermal stability of ion-implanted ZnO SO APPLIED PHYSICS LETTERS LA English DT Article ID SINGLE-CRYSTAL ZNO; SURFACES; DEVICES; DAMAGE AB Zinc oxide single crystals implanted at room temperature with high-dose (1.4x10(17) cm(-2)) 300 keV As+ ions are annealed at 1000-1200 degrees C. Damage recovery is studied by a combination of Rutherford backscattering/channeling spectrometry (RBS/C), cross-sectional transmission electron microscopy (XTEM), and atomic force microscopy. Results show that such a thermal treatment leads to the decomposition and evaporation of the heavily damaged layer instead of apparent defect recovery and recrystallization that could be inferred from RBS/C and XTEM data alone. This study shows that heavily damaged ZnO has relatively poor thermal stability compared to as-grown ZnO which is a significant result and has implications for understanding results on thermal annealing of ion-implanted ZnO. (c) 2005 Americian Institute of Physics. C1 Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT 0200, Australia. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Queensland, Sch Engn, St Lucia, Qld 4072, Australia. Univ Queensland, Ctr Microscopy & Microanal, St Lucia, Qld 4072, Australia. RP Coleman, VA (reprint author), Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, GPO Box 4, Canberra, ACT 0200, Australia. EM victoria.coleman@anu.edu.au RI Zou, Jin/B-3183-2009; Coleman, Victoria/E-2337-2013; Tan, Hark Hoe/M-1148-2015 OI Zou, Jin/0000-0001-9435-8043; Coleman, Victoria/0000-0002-4630-3803; Tan, Hark Hoe/0000-0002-7816-537X NR 20 TC 32 Z9 32 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 DEC 5 PY 2005 VL 87 IS 23 AR 231912 DI 10.1063/1.2140481 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200034 ER PT J AU Luo, J Gupta, VK Yoon, DH Meyer, HM AF Luo, J Gupta, VK Yoon, DH Meyer, HM TI Segregation-induced grain boundary premelting in nickel-doped tungsten SO APPLIED PHYSICS LETTERS LA English DT Article ID EQUILIBRIUM-THICKNESS; BI2O3-DOPED ZNO; AMORPHOUS FILMS; STABILITY; SURFACES; GROWTH; OXIDE AB High-resolution transmission electron microscopy and Auger spectroscopy have revealed the formation of nanometer-thick, Ni-enriched, disordered, grain boundary layers in Ni-doped W specimens at 95 degrees C below the bulk eutectic temperature. The stabilization of subeutectic liquid-like grain boundary cores in this model two-component metallic alloy is phenomenologically analogous to the long-sought phenomenon of grain boundary premelting. The existence of such disordered nanostructures at metallic grain boundaries provides insights to resolve several long-standing controversies in interpreting the unique grain boundary diffusion/migration kinetics and mechanical properties for this system, and can have technological importance for a broader range of materials. (c) 2005 American Institute of Physics. C1 Clemson Univ, Sch Mat Sci & Engn, Clemson, SC 29634 USA. Clemson Univ, COMSET, Clemson, SC 29634 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Luo, J (reprint author), Clemson Univ, Sch Mat Sci & Engn, Clemson, SC 29634 USA. EM jianluo@clemson.edu RI Luo, Jian/A-4777-2008 NR 28 TC 79 Z9 81 U1 0 U2 25 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 DEC 5 PY 2005 VL 87 IS 23 AR 231902 DI 10.1063/1.2138796 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200024 ER PT J AU Paravastu, AK Coles, PJ Reimer, JA Ladd, TD Maxwell, RS AF Paravastu, AK Coles, PJ Reimer, JA Ladd, TD Maxwell, RS TI Photocurrent-modulated optical nuclear polarization in bulk GaAs SO APPLIED PHYSICS LETTERS LA English DT Article ID SEMIINSULATING GAAS; SPIN POLARIZATION; NMR AB Application of a dc electric field to bulk, semi-insulating, GaAs during laser irradiation was observed to significantly affect optically pumped nuclear spin polarizations. Changes to nuclear polarizations correlated with nonlinear photoconductivity, and both depended significantly on excitation photon energy. Many aspects of the data could be explained by electric field-dependent population transfer between trapped and delocalized electronic spin reservoirs. These results indicate that semi-insulating GaAs could be a platform for localized optical and electric field control of nuclear spin polarization. (c) 2005 Americian Institute of Physics. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Stanford Univ, Edward L Ginzton Lab, Stanford, CA 94305 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. EM reimer@socrates.berkeley.edu RI Ladd, Thaddeus/A-1136-2007; Ladd, Thaddeus/C-5822-2009 NR 16 TC 6 Z9 6 U1 1 U2 2 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 DEC 5 PY 2005 VL 87 IS 23 AR 232109 DI 10.1063/1.2140484 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200047 ER PT J AU Tsetseris, L Pantelides, ST AF Tsetseris, L Pantelides, ST TI Atomic-scale mechanisms of selective adsorption and dimerization of pentacene on Si surfaces SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILM TRANSISTORS; SCANNING-TUNNELING-MICROSCOPY; SILICON; VAPOR AB We report results of first-principles calculations in terms of which we elucidate the mechanisms for nucleation and initial growth of pentacene films on Si. Pentacene molecules bond in flat, distorted configurations on bare surfaces. On H-passivated surfaces, direct bonding or H replacement are not energetically favored. However, molecules bond in an upright configuration at isolated depassivated Si dangling bonds and film growth continues over the passivated area. The results elucidate generic adsorption issues on inert surfaces and suggest procedures for controlling film growth. (c) 2005 American Institute of Physics. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. EM leonidas.tsetseris@vanderbilt.edu NR 26 TC 20 Z9 20 U1 0 U2 38 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 DEC 5 PY 2005 VL 87 IS 23 AR 233109 DI 10.1063/1.2139989 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200070 ER PT J AU Zepeda-Ruiz, LA Gilmer, GH Sadigh, B Caro, A Oppelstrup, T Hamza, AV AF Zepeda-Ruiz, LA Gilmer, GH Sadigh, B Caro, A Oppelstrup, T Hamza, AV TI Atomistic simulations of grain boundary pinning in CuFe alloys SO APPLIED PHYSICS LETTERS LA English DT Article ID COPPER; EMBRITTLEMENT; SEGREGATION; MIGRATION AB We apply a hybrid Monte Carlo-molecular dynamics code to the study of grain boundary motion upon annealing of pure Cu and Cu with low concentrations of Fe. The hybrid simulations account for segregation and precipitation of the low solubility Fe, together with curvature-driven grain boundary motion. Grain boundaries in two different systems, a Sigma 7+U-shaped half-loop grain and a nanocrystalline sample, were found to be pinned in the presence of Fe concentrations exceeding 3%. (c) 2005 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. NADA, KTH, Royal Inst Technol, S-10044 Stockholm, Sweden. RP Zepeda-Ruiz, LA (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. EM zepedaruiz1@llnl.gov NR 15 TC 14 Z9 14 U1 0 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 5 PY 2005 VL 87 IS 23 AR 231904 DI 10.1063/1.2137871 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200026 ER PT J AU Zhang, X Misra, A Wang, H Swadener, JG Lima, AL Hundley, MF Hoagland, RG AF Zhang, X Misra, A Wang, H Swadener, JG Lima, AL Hundley, MF Hoagland, RG TI Thermal stability of sputter-deposited 330 austenitic stainless-steel thin films with nanoscale growth twins SO APPLIED PHYSICS LETTERS LA English DT Article ID INSTRUMENTED SHARP INDENTATION; ELECTRICAL-RESISTIVITY; ULTRAHIGH-STRENGTH; RESIDUAL-STRESSES; COPPER; HARDNESS AB We have explored the thermal stability of nanoscale growth twins in sputter-deposited 330 stainless-steel (SS) films by vacuum annealing up to 500 degrees C. In spite of an average twin spacing of only 4 nm in the as-deposited films, no detectable variation in the twin spacing or orientation of twin interfaces was observed after annealing. An increase in the average columnar grain size was observed after annealing. The hardness of 330 SS films increases after annealing, from 7 GPa for as-deposited films to around 8 GPa for annealed films, while the electrical resistivity decreases slightly after annealing. The changes in mechanical and electrical properties after annealing are interpreted in terms of the corresponding changes in the residual stress and microstructure of the films. (c) 2005 American Institute of Physics. C1 Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. EM zhangx@tamu.edu RI Hoagland, Richard/G-9821-2012; Misra, Amit/H-1087-2012; Wang, Haiyan/P-3550-2014; OI Wang, Haiyan/0000-0002-7397-1209; Swadener, John G/0000-0001-5493-3461 NR 18 TC 21 Z9 21 U1 2 U2 26 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 DEC 5 PY 2005 VL 87 IS 23 AR 233116 DI 10.1063/1.2135871 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200077 ER PT J AU Zurbuchen, MA Wu, T Saha, S Mitchell, J Streiffer, SK AF Zurbuchen, MA Wu, T Saha, S Mitchell, J Streiffer, SK TI Multiferroic composite ferroelectric-ferromagnetic films SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; LAYERED LA1.2SR1.8MN2O7; T-C; POLARIZATION; COEFFICIENTS; GROWTH AB Multiferroic behavior was confirmed for epitaxial composite ferroelectric-ferromagnetic heterostructures, using a ferromagnetic crystal as both substrate and straining medium. Heterostructures having 2-2 connectivity (plane-on-plane) were fabricated by chemical solution deposition of Pb(Zr-0.3,Ti-0.7)O-3 (PZT) thin films on La1.2Sr1.8Mn2O7 (LSMO) single crystal substrates. Magnetostriction (0.13%) of the substrate at its transition temperature (similar to 105 K) induces an abrupt 7.3% increase in switchable polarization of the PZT. This confirmation of elastic coupling induced by the onset of ferromagnetism is a first step toward fabricating such structures for study of the interrelationship of their magnetic and electrical field-dependent behaviors. (c) 2005 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. EM mark_z@mac.com RI Streiffer, Stephen/A-1756-2009; Wu, Tom/A-1158-2012; Zurbuchen, Mark/H-1664-2012 OI Wu, Tom/0000-0003-0845-4827; Zurbuchen, Mark/0000-0002-8947-6309 NR 22 TC 41 Z9 44 U1 2 U2 40 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 5 PY 2005 VL 87 IS 23 AR 232908 DI 10.1063/1.2135989 PG 3 WC Physics, Applied SC Physics GA 990DK UT WOS:000233723200061 ER PT J AU Pfleger, BF Fawzi, NJ Keasling, JD AF Pfleger, BF Fawzi, NJ Keasling, JD TI Optimization of DsRed production in Escherichia coli: Effect of ribosome binding site sequestration on translation efficiency SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article ID RED FLUORESCENT PROTEIN; MESSENGER-RNA; MONOMERIC RED; EXPRESSION; VARIANTS; BACTERIA AB DsRed-Express, a popular reporter protein, cannot be expressed in Escherichia coli using a consensus ribosome binding site (RBS) potentially due to base-pairing in the RBS that inhibits translation initiation. Saturation mutagenesis was used to probe for a gene sequence that minimized base-pairing in the RBS while maintaining the same spectral properties and maturation characteristics as DsRed-Express. The new DsRed, designated here as RFPEC for E. coli optimized red fluorescent protein, fluoresces 2.5 times greater than DsRed-Express when expressed from the same vector. (c) 2005 Wiley Periodicals, Inc. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Bioengn, Berkeley, CA USA. Lawrence Berkeley Natl Lab, Dept Synthet Biol, Phys Biosci Div, Berkeley, CA USA. RP Keasling, JD (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Keasling, Jay/J-9162-2012; Fawzi, Nicolas/E-2555-2013 OI Keasling, Jay/0000-0003-4170-6088; Fawzi, Nicolas/0000-0001-5483-0577 NR 17 TC 19 Z9 19 U1 0 U2 8 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD DEC 5 PY 2005 VL 92 IS 5 BP 553 EP 558 DI 10.1002/bit.20630 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 990LD UT WOS:000233743600004 PM 16247774 ER PT J AU Goretta, KC Singh, D Cruse, TA Erdemir, A Routbort, JL Gutierrez-Mora, F de Arellano-Lopez, AR Orlova, TS Smirnov, BI AF Goretta, KC Singh, D Cruse, TA Erdemir, A Routbort, JL Gutierrez-Mora, F de Arellano-Lopez, AR Orlova, TS Smirnov, BI TI Si3N4/BN fibrous monoliths: Mechanical properties and tribological responses SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Recent Advances in Composite Materials (ICRACM 2004) CY DEC 17-19, 2004 CL Banaras Hindu Univ, Varanasi, INDIA HO Banaras Hindu Univ DE fibrous monolith; ceramic composite; mechanical properties ID CERAMIC COMPOSITES; NITRIDE; FRACTURE; MICROSTRUCTURE; FABRICATION; INELASTICITY; TEMPERATURE; ELASTICITY; OXIDATION AB Ceramic fibrous monoliths (FMs) consist of fiber-like cells that surround a weaker matrix phase called the cell boundary. FMs based on Si3N4/BN exhibit many excellent mechanical properties, and much work has been done to characterize and understand the relations among their processing, microstructure, and properties. The following body of data and understanding for Si3N4/BN FMs are discussed in this paper: processing, elastic constants, in-plane fracture and modeling of fracture, thermal Stresses, interfacial shear strength and tailoring of gross interface structure, creep, impact erosion resistance, and sliding wear resistance. Possibilities to improve their properties are also presented. (c) 2005 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Univ Sevilla, Dept Fis Mat Condensada, E-41080 Seville, Spain. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. RP Goretta, KC (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM goretta@anl.gov RI Orlova, Tatiana/E-5877-2014; Gutierrez-Mora, Felipe/H-4625-2015; OI Gutierrez-Mora, Felipe/0000-0003-3632-7163; R. de Arellano Lopez, Antonio/0000-0002-7443-0244 NR 33 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 5 PY 2005 VL 412 IS 1-2 SI SI BP 146 EP 152 DI 10.1016/j.msea.2005.08.042 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 994MY UT WOS:000234037100026 ER PT J AU Tolley, A Mitlin, D Radmilovic, V Dahmen, U AF Tolley, A Mitlin, D Radmilovic, V Dahmen, U TI Transmission electron microscopy analysis of grain boundary precipitate-free-zones (PFZs) in an AlCuSiGe alloy SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Recent Advances in Composite Materials (ICRACM 2004) CY DEC 17-19, 2004 CL Banaras Hindu Univ, Varanasi, INDIA HO Banaras Hindu Univ DE aluminum alloy design; transmission electron microscopy (TEM); solid state precipitation; microstructural evolution; grain boundaries; precipitate-free-zones (PFZs) ID AL-SI-GE; GUINIER-PRESTON ZONES; ALUMINIUM ALLOYS; CU-ALLOYS; ADDITIONS; EVOLUTION; DEFECTS AB We have characterized the elevated temperature (190 degrees C) precipitation sequence near the grain boundaries of an AlCuSiGe alloy, comparing these results to the binary AlCu and the ternary AlSiGe. In the quaternary alloy, there is a graded microstructure that evolves with increasing distance from the boundaries, which is generally a superposition of the precipitate-free-zones (PFZs) in the binary AlCu and in the ternary AlSiGe. After aging for 3 h, this graded area consists of an approximately 140 nm wide region that is entirely precipitate free, followed by a 400 nm wide region that is denuded of Si-Ge and theta' precipitates. Rather than containing the (Si-Ge)-theta' pairs observed in the bulk, this 400 nm wide region contains only homogeneously nucleated theta". Only in the overaged condition (144 h) are the near grain boundary theta" replaced by a coarse distribution of large plate-like theta'. In the alloys, the solute depleted zones are much narrower than the total length of the PFZ. For example, in both AlCu and AlCuSiGe, the Cu depleted zone is only 30 nm wide. This underscores the need for vacancies during precipitation of not only theta' and Si-Ge, but of theta" as well. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2G6, Canada. RP Radmilovic, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. EM VRRadmilovic@lbl.gov RI Mitlin , David /M-5328-2016 OI Mitlin , David /0000-0002-7556-3575 NR 26 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 5 PY 2005 VL 412 IS 1-2 SI SI BP 204 EP 213 DI 10.1016/j.msea.2005.07.017 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 994MY UT WOS:000234037100035 ER PT J AU Kimmich, BFM Fagan, PJ Hauptman, E Marshall, WJ Bullock, RM AF Kimmich, BFM Fagan, PJ Hauptman, E Marshall, WJ Bullock, RM TI Molybdenum carbonyl complexes in the solvent-free catalytic hydrogenation of ketones SO ORGANOMETALLICS LA English DT Article ID TRANSITION-METAL HYDRIDES; IONIC HYDROGENATIONS; LOW-TEMPERATURE; STRUCTURAL CHARACTERIZATION; ORGANOMETALLIC CHEMISTRY; AQUEOUS-SOLUTION; GREEN CHEMISTRY; TRITYL CATION; H/D EXCHANGE; TUNGSTEN AB The heterodifunctional ligand Li[eta(5)-C5H4(CH2)(2)PR2] (R = Ph, Cy, and Bu-t) reacts with MO(CO)(3)(diglyme) to give the molybdenum anion complex Li{Mo(CO)(3) [eta(5)-C5H4(CH2)(2)PR2]}. Protonation with HOAc gives the metal hydride complexes HMo(CO)(2)[eta(5):eta(1)-C5H4(CH2)(2)PR2], in which the phosphine and cyclopentadienyl ligands are linked by a two-carbon bridge. Crystal structures of HMo(CO)(2) [eta(5):eta(1)-C5H4(CH2)(2)PR2] with all three R groups (R = Ph, Cy, and tBu) are reported. Syntheses of the C-3-bridged complex, HMo(CO)(2) [eta(5):eta(1)-C4H5(CH2)(3)-PPh2], and a W analogue, HW(CO)(3) [eta(5)-C5H4(CH2)(2)(PBu2)-Bu-t], were carried out by analogous routes. Hydride transfer to Ph3C+BAr'(-)(4) [Ar' = 3,5-bis(trifluoromethyl)phenyl] from the catalyst precursors HMo(CO)(2) [eta(5):eta(1)-C5H4(CH2)(2)PR2] leads to homogeneous catalysts for hydrogenation of ketones, with the best performance being found for R = Cy. Protonation of HMo(CO)(2)[eta(5):eta(1)-C5H4(CH2)(2)PR2], by HOTf leads to metal triflate complexes (TfO)MO(CO)(2)[eta(5):eta(1)-C5H4(CH2)(2)PR2], which are used in ketone hydrogenation. Compared to the previously prepared complexes that did not have the phosphine and Cp linked together, these new complexes provide catalysts that have much longer lifetimes (up to about 500 turnovers) and higher thermal stability. Solvent-free ketone hydrogenation can be carried out with these complexes at catalyst loadings as low as 0.1 mol %. C1 Brookhaven Natl Lab, Chem Dept, Upton, NY 11973 USA. DuPont Co Inc, Cent Res & Dev Dept, Wilmington, DE 19880 USA. RP Bullock, RM (reprint author), Brookhaven Natl Lab, Chem Dept, Upton, NY 11973 USA. EM bullock@bnl.gov RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 56 TC 47 Z9 48 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD DEC 5 PY 2005 VL 24 IS 25 BP 6220 EP 6229 DI 10.1021/om050564h PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 989BR UT WOS:000233648400018 ER PT J AU Rosenberg, OS Deindl, S Sung, RJ Nairn, AC Kuriyan, J AF Rosenberg, OS Deindl, S Sung, RJ Nairn, AC Kuriyan, J TI Structure of the autoinhibited kinase domain of CaMKII and SAXS analysis of the holoenzyme SO CELL LA English DT Article ID DEPENDENT PROTEIN-KINASE; CRYSTAL-STRUCTURE; BIOLOGICAL MACROMOLECULES; SOLUTION SCATTERING; CALMODULIN; AUTOPHOSPHORYLATION; SUBSTRATE; ALPHA; SUBUNIT; SITE AB Ca2+/calmodulin-dependent protein kinase-II (CaMKII) is unique among protein kinases for its dodecameric assembly and its complex response to Ca2+. The crystal structure of the autoinhibited kinase domain of CaMKII, determined at 1.8 angstrom resolution, reveals an unexpected dimeric organization in which the calmodulin-responsive regulatory segments form a coiled-coil strut that blocks peptide and ATP binding to the otherwise intrinsically active kinase domains. A threonine residue in the regulatory segment, which when phosphorylated renders CaMKII calmodulin independent, is held apart from the catalytic sites by the organization of the dimer. This ensures a strict Ca2+ dependence for initial activation. The structure of the kinase dimer, when combined with small-angle X-ray scattering data for the holoenzyme, suggests that inactive CaMKII forms tightly packed autoinhibited assemblies that convert upon activation into clusters of loosely tethered and independent kinase domains. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Yale Univ, Sch Med, Dept Cell Biol, New Haven, CT 06508 USA. Yale Univ, Sch Med, Dept Psychiat, New Haven, CT 06508 USA. RP Kuriyan, J (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. EM kuriyan@berkeley.edu OI Nairn, Angus/0000-0002-7075-0195; Deindl, Sebastian/0000-0001-6807-8654 NR 54 TC 157 Z9 163 U1 3 U2 9 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD DEC 2 PY 2005 VL 123 IS 5 BP 849 EP 860 DI 10.1016/j.cell.2005.10.029 PG 12 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 991KY UT WOS:000233814100018 PM 16325579 ER PT J AU Pelletier, JD Harrington, CD Whitney, JW Cline, M DeLong, SB Keating, G Ebert, KT AF Pelletier, JD Harrington, CD Whitney, JW Cline, M DeLong, SB Keating, G Ebert, KT TI Geomorphic control of radionuclide diffusion in desert soils SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Diffusion is a standard model for the vertical migration of radionuclides in soil profiles. Here we show that diffusivity values inferred from fallout Cs-137 profiles in soils on the Fortymile Wash alluvial fan, Nye County, Nevada, have a strong inverse correlation with the age of the geomorphic surface. This result suggests that radionuclide-bound particles are predominantly transported by infiltration rather than by bulk-mixing processes such as wetting/drying, freeze/thaw, and bioturbation. Our results provide a preliminary basis for using soil-geomorphic mapping, point-based calibration data, and the diffusion model to predict radionuclide transport in desert soils within a pedotransfer-function approach. C1 Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. US Geol Survey, Denver Fed Ctr, Lakewood, CO 80225 USA. RP Pelletier, JD (reprint author), Univ Arizona, Dept Geosci, Gould Simpson Bldg,1040 E 4th St, Tucson, AZ 85721 USA. EM jon@geo.arizona.edu OI DeLong, Stephen/0000-0002-0945-2172 NR 13 TC 4 Z9 4 U1 0 U2 6 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 DEC 2 PY 2005 VL 32 IS 23 AR L23401 DI 10.1029/2005GL024347 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 993EI UT WOS:000233935800006 ER PT J AU Kim, H Guiochon, G AF Kim, H Guiochon, G TI Thermodynamic functions and intraparticle mass transfer kinetics of structural analogues of a template on molecularly imprinted polymers in liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE Fmoc-L-tryptophan imprinted polymers; frontal analysis; isotherm parameters; van't Hoff plot; entropy; enthalpy; POR model; surface diffusion; isosteric heat of adsorption ID CONCENTRATION-DEPENDENCE; STATIONARY-PHASE; BINDING; RECOGNITION; SEPARATIONS; ENANTIOMERS; PARAMETERS AB The parameters of the thermodynamics and mass transfer kinetics of the structural analogues (L-enantiomers) of the template were measured on an Fmoc-L-tryptophan (Fmoc-L-Trp) imprinted polymer, at different temperatures. The equilibrium isotherm data and the overloaded band profiles of these compounds were measured at temperatures of 298, 313, 323, and 333 K. The isotherm data were modeled. The thermodynamic functions of the different adsorption sites were derived from the isotherm parameters, using van't Hoff plots. The mass transfer parameters were derived by comparing the experimental peak profiles and profiles calculated using the lumped pore diffusion (POR) model for chromatography. These data show that (1) the strength between the substrate molecules and the MIP increases with increasing number of functional groups on the substrates; (2) enthalpy is the driving force for the affinity of the substrates for the MIP; (3) surface diffusion is the dominant mass transfer mechanism of the substrates through the porous MIP. For those substrate molecules that have the same stereochemistry as the template, the energetic surface heterogeneity needs to be incorporated into the surface diffusion coefficients. Heterogeneous surface diffusivities decrease with increasing affinity of the substrates for the MIP. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 21 TC 22 Z9 23 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD DEC 2 PY 2005 VL 1097 IS 1-2 BP 84 EP 97 DI 10.1016/j.chroma.2005.08.020 PG 14 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 989KL UT WOS:000233672400011 PM 16298188 ER PT J AU Gritti, F Guiochon, G AF Gritti, F Guiochon, G TI Systematic errors in the measurement of adsorption isotherms by frontal analysis - Impact of the choice of column hold-up volume, range and density of the data points SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE adsorption isotherm; frontal analysis; systematic errors; column hold-up volume; data acquisition; isotherm modeling; overloaded band profiles ID PHASE LIQUID-CHROMATOGRAPHY; NONLINEAR CHROMATOGRAPHY; SURFACE HETEROGENEITY; C-18-BONDED SILICA; BAND PROFILES; RETENTION; PRESSURE; COMPRESSIBILITY; PROPAGATION; EQUILIBRIA AB Besides the accuracy and the precision of the measurements of the data points, several important parameters affect the accuracy of the adsorption isotherms that are derived from the data acquired by frontal analysis (FA). The influence of these parameters is discussed. First, the effects of the width of the concentration range within which the adsorption data are measured and of the distribution of the data points in this range are investigated. Systematic elimination of parts of the data points before the calculation of the nonlinear regression of the data to the model illustrates the importance of the numbers of data points (1) within the linear range and (2) at high concentrations. The influence of the inaccuracy of the estimate of the column hold-up volume on each adsorption data point, on the selection of the isotherm model, and on the best estimates of the adsorption isotherm parameters is also stressed. Depending on the method used to measure it, the hold-up time can vary by more than 10%. The high concentration part of the adsorption isotherm is particularly sensitive to errors made on t(0,exp) and as a result, when the isotherm follows bi-Langmuir isotherm behavior, the equilibrium constant of the low-energy sites may change by a factor 2. This study shows that the agreement between calculated and experimental overloaded band profiles is a necessary condition to validate the choice of an adsorption model and the calculation of its numerical parameters but that this condition is not sufficient. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, 552 Buehler Hall, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 30 TC 36 Z9 37 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD DEC 2 PY 2005 VL 1097 IS 1-2 BP 98 EP 115 DI 10.1016/j.chroma.2005.08.029 PG 18 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 989KL UT WOS:000233672400012 PM 16298189 ER PT J AU Beiersdorfer, P Chen, H Thorn, DB Trabert, E AF Beiersdorfer, P Chen, H Thorn, DB Trabert, E TI Measurement of the two-loop lamb shift in lithiumlike U89+ SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2P(1/2)-2S TRANSITION ENERGY; BEAM ION-TRAP; X-RAY; ISOELECTRONIC SEQUENCE; GROUND-STATE; SPECTROMETER AB Using the SuperEBIT electron beam ion trap, we have measured the 2s(1/2)-2p(1/2) transitions in U88+ and U89+. The measured value of 280.645 +/- 0.015 eV for Li-like U89+ improves the available precision by nearly an order of magnitude and establishes a new benchmark for testing the total QED contribution to the transition energy within a fractional accuracy of 3.6x10(-4). We infer a value for the 2s two-loop Lamb shift in U89+ of -0.23 eV, from which we estimate a value of -1.27 eV for the 1s two-loop Lamb shift in U91+. C1 Lawrence Livermore Natl Lab, Dept Phys & Adv Technol, Livermore, CA 94550 USA. RP Beiersdorfer, P (reprint author), Lawrence Livermore Natl Lab, Dept Phys & Adv Technol, POB 5508, Livermore, CA 94550 USA. EM beiersdorfer@llnl.gov NR 23 TC 91 Z9 92 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 2 PY 2005 VL 95 IS 23 AR 233003 DI 10.1103/PhysRevLett.95.233003 PG 4 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000029 PM 16384304 ER PT J AU Ma, JX Gillaspie, DT Plummer, EW Shen, J AF Ma, JX Gillaspie, DT Plummer, EW Shen, J TI Visualization of localized holes in manganite thin films with atomic resolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL-INSULATOR-TRANSITION; COLOSSAL-MAGNETORESISTANCE; PEROVSKITE MANGANITES; DOPED MANGANITES; PHASE-SEPARATION; DOUBLE-EXCHANGE; LA1-XCAXMNO3; LA1-XSRXMNO3; COEXISTENCE; POLARONS AB The magnetic and transport behaviors of manganites are critically related to the spatial distribution and correlation of doped holes. Using in situ scanning tunneling microscopy, we have imaged both occupied and unoccupied states simultaneously in a hole-doped (La5/8-0.3Pr0.3)Ca3/8MnO3 epitaxial thin film grown by laser molecular beam epitaxy. Doped holes localized on Mn4+ ion sites were directly observed with atomic resolution in the paramagnetic state at room temperature. In contrast to a random distribution, these doped holes show strong short-range correlation and clear preference of forming nanoscale CE-type charge-order-like clusters. The results provide direct visualization of the nature of intriguing electronic inhomogeneity in transition metal oxides. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Shen, J (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. EM shenj@ornl.gov RI Gillaspie, Dane/E-2731-2010 NR 31 TC 38 Z9 38 U1 0 U2 17 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 DEC 2 PY 2005 VL 95 IS 23 AR 237210 DI 10.1103/PhysRevLett.95.237210 PG 4 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000067 PM 16384342 ER PT J AU Maier, TA Jarrell, M Schulthess, TC Kent, PRC White, JB AF Maier, TA Jarrell, M Schulthess, TC Kent, PRC White, JB TI Systematic study of d-wave superconductivity in the 2D repulsive Hubbard model SO PHYSICAL REVIEW LETTERS LA English DT Article AB The cluster size dependence of superconductivity in the conventional two-dimensional Hubbard model, commonly believed to describe high-temperature superconductors, is systematically studied using the dynamical cluster approximation and quantum Monte Carlo simulations as a cluster solver. Because of the nonlocality of the d-wave superconducting order parameter, the results on small clusters show large size and geometry effects. In large enough clusters, the results are independent of the cluster size and display a finite temperature instability to d-wave superconductivity. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Maier, TA (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RI Kent, Paul/A-6756-2008; Maier, Thomas/F-6759-2012 OI Kent, Paul/0000-0001-5539-4017; Maier, Thomas/0000-0002-1424-9996 NR 19 TC 153 Z9 153 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 2 PY 2005 VL 95 IS 23 AR 237001 DI 10.1103/PhysRevLett.95.237001 PG 4 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000055 PM 16384330 ER PT J AU Pascalutsa, V Vanderhaeghen, M AF Pascalutsa, V Vanderhaeghen, M TI Electromagnetic nucleon-to-delta transition in chiral effective-field theory SO PHYSICAL REVIEW LETTERS LA English DT Article ID PERTURBATION-THEORY; DELTA(1232) RESONANCE; PION-PHOTOPRODUCTION; FORM-FACTORS; MODEL; ELECTROPRODUCTION; GAMMA; P((E)OVER-RIGHT-ARROW; DEPENDENCE; PARTICLES AB We perform a relativistic chiral effective-field theory calculation of pion electroproduction off the nucleon (e(-)N -> e(-)N pi) in the Delta(1232)-resonance region. After fixing the three low-energy constants, corresponding to the magnetic (M1), electric (E2), and Coulomb (C2) gamma N Delta couplings, our calculation provides a prediction for the momentum transfer and pion-mass dependence of the gamma N Delta form factors. The prediction for the pion-mass dependence resolves the discrepancy between the recent lattice QCD results and the experimental value for the "C2/M1 ratio" at low Q(2). C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. RP Pascalutsa, V (reprint author), Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. EM vlad@jlab.org; marcvdh@jlab.org OI Pascalutsa, Vladimir/0000-0002-2613-6104 NR 43 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 2 PY 2005 VL 95 IS 23 AR 232001 DI 10.1103/PhysRevLett.95.232001 PG 4 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000022 PM 16384297 ER PT J AU Roy, PK Yu, SS Henestroza, E Anders, A Bieniosek, FM Coleman, J Eylon, S Greenway, WG Leitner, M Logan, BG Waldron, WL Welch, DR Thoma, C Sefkow, AB Gilson, EP Efthimion, PC Davidson, RC AF Roy, PK Yu, SS Henestroza, E Anders, A Bieniosek, FM Coleman, J Eylon, S Greenway, WG Leitner, M Logan, BG Waldron, WL Welch, DR Thoma, C Sefkow, AB Gilson, EP Efthimion, PC Davidson, RC TI Drift compression of an intense neutralized ion beam SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHAMBER-TRANSPORT; FUSION; SIMULATION; DYNAMICS AB Longitudinal compression of a velocity-tailored, intense neutralized K+ beam at 300 keV, 25 mA has been demonstrated. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity ramp that longitudinally compresses the neutralized beam, enhancing the beam peak current by a factor of 50 and producing a pulse duration of about 3 ns. This measurement has been confirmed independently with two different diagnostic systems. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. ATK Mission Res, Albuquerque, NM 87110 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 23 TC 96 Z9 97 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 DEC 2 PY 2005 VL 95 IS 23 AR 234801 DI 10.1103/PhysRevLett.95.234801 PG 4 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000034 PM 16384309 ER PT J AU Valiente-Dobon, JJ Steinhardt, T Svensson, CE Afanasjev, AV Ragnarsson, I Andreoiu, C Austin, RAE Carpenter, MP Dashdorj, D de Angelis, G Donau, F Eberth, J Farnea, E Freeman, SJ Gadea, A Garrett, PE Gorgen, A Grinyer, GF Hyland, B Jenkins, D Johnston-Theasby, F Joshi, P Jungclaus, A Lieb, KP Macchiavelli, AO Moore, EF Mukherjee, G Napoli, DR Phillips, AA Plettner, C Reviol, W Sarantites, D Schnare, H Schumaker, MA Schwengner, R Seweryniak, D Smith, MB Stefanescu, I Thelen, O Wadsworth, R AF Valiente-Dobon, JJ Steinhardt, T Svensson, CE Afanasjev, AV Ragnarsson, I Andreoiu, C Austin, RAE Carpenter, MP Dashdorj, D de Angelis, G Donau, F Eberth, J Farnea, E Freeman, SJ Gadea, A Garrett, PE Gorgen, A Grinyer, GF Hyland, B Jenkins, D Johnston-Theasby, F Joshi, P Jungclaus, A Lieb, KP Macchiavelli, AO Moore, EF Mukherjee, G Napoli, DR Phillips, AA Plettner, C Reviol, W Sarantites, D Schnare, H Schumaker, MA Schwengner, R Seweryniak, D Smith, MB Stefanescu, I Thelen, O Wadsworth, R TI Evidence for nontermination of rotational bands in Kr-74 SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAMMA-RAY SPECTROSCOPY; CHANNEL-SELECTION; COLLECTIVITY; REGION; GAMMASPHERE; TERMINATION; MICROBALL; DETECTOR; DEVICE; DESIGN AB Three rotational bands in Kr-74 were studied up to (in one case one transition short of) the maximum spin I-max of their respective single-particle configurations. Their lifetimes have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments reveal a modest decrease, but far from a complete loss of collectivity at the maximum spin I-max. This feature, together with the results of mean field calculations, indicates that the observed bands do not terminate at I=I-max. C1 Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Mississippi State Univ, Dept Phys & Astron, Mississippi State, MS 39762 USA. Lund Inst Technol, S-22100 Lund, Sweden. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. McMaster Univ, Hamilton, ON L8S 4K1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. FZ Rossendorf, Inst Kern & Hadronenphys, D-01314 Dresden, Germany. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Sez Padova, Padua, Italy. TRIUMF, Vancouver, BC V6T 2A3, Canada. CEA Saclay, DAPNIA, SPhN, F-91191 Gif Sur Yvette, France. Univ York, Dept Phys, York YO10 5DD, N Yorkshire, England. Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain. Univ Gottingen, Inst Phys 2, D-37073 Gottingen, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. RP Valiente-Dobon, JJ (reprint author), Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. EM valiente@lnl.infn.it RI Freeman, Sean/B-1280-2010; Gadea, Andres/L-8529-2014; Carpenter, Michael/E-4287-2015; Napoli, Daniel R./D-9863-2012 OI Freeman, Sean/0000-0001-9773-4921; Gadea, Andres/0000-0002-4233-1970; Carpenter, Michael/0000-0002-3237-5734; Napoli, Daniel R./0000-0002-8154-6958 NR 21 TC 35 Z9 36 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 DEC 2 PY 2005 VL 95 IS 23 AR 232501 DI 10.1103/PhysRevLett.95.232501 PG 5 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000025 PM 16384300 ER PT J AU Vojta, T Schmalian, J AF Vojta, T Schmalian, J TI Percolation quantum phase transitions in diluted magnets SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSVERSE ISING-MODEL; HEISENBERG-ANTIFERROMAGNET; SQUARE LATTICE; TEMPERATURE; BOUNDS AB We show that the interplay of geometric criticality and quantum fluctuations leads to a novel universality class for the percolation quantum phase transition in diluted magnets. All critical exponents involving dynamical correlations are different from the classical percolation values, but in two dimensions they can nonetheless be determined exactly. We develop a complete scaling theory of this transition, and we relate it to recent experiments in La2Cu1-p(Zn,Mg)(p)O-4. Our results are also relevant for disordered interacting boson systems. C1 Univ Missouri, Dept Phys, Rolla, MO 65409 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Vojta, T (reprint author), Univ Missouri, Dept Phys, Rolla, MO 65409 USA. RI Schmalian, Joerg/H-2313-2011 NR 29 TC 26 Z9 26 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 2 PY 2005 VL 95 IS 23 AR 237206 DI 10.1103/PhysRevLett.95.237206 PG 4 WC Physics, Multidisciplinary SC Physics GA 990DS UT WOS:000233724000063 PM 16384338 ER PT J AU Siridechadilok, B Fraser, CS Hall, RJ Doudna, JA Nogales, E AF Siridechadilok, B Fraser, CS Hall, RJ Doudna, JA Nogales, E TI Structural roles for human translation factor eIF3 in initiation of protein synthesis SO SCIENCE LA English DT Article ID HEPATITIS-C VIRUS; 40S RIBOSOMAL-SUBUNIT; MESSENGER-RNA; EUKARYOTIC TRANSLATION; ESCHERICHIA-COLI; CRYO-EM; ASSOCIATION; IDENTIFICATION; RECRUITMENT; INTERFACE AB Protein synthesis in mammalian cells requires initiation factor eIF3, a similar to 750-kilodalton complex that controls assembly of 40S ribosomal subunits on messenger RNAs (mRNAs) bearing either a 5'-cap or an internal ribosome entry site (IRES). Cryo-electron microscopy reconstructions show that eIF3, a five-lobed particle, interacts with the hepatitis C virus (HCV) IRES RNA and the S'-cap binding complex eIF4F via the same domain. Detailed modeling of eIF3 and eIF4F onto the 40S ribosomal subunit reveals that eIF3 uses eIF4F or the HCV IRES in structurally similar ways to position the mRNA strand near the exit site of 40S, promoting initiation complex assembly. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Doudna, JA (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 229 Stanley Hall, Berkeley, CA 94720 USA. EM doudna@berkeley.edu; enogales@lbl.gov RI Fraser, Christopher/H-9186-2013 NR 30 TC 193 Z9 207 U1 1 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 2 PY 2005 VL 310 IS 5753 BP 1513 EP 1515 DI 10.1126/science.1118977 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 990PU UT WOS:000233756500049 PM 16322461 ER PT J AU Castillo, P Rieben, R White, D AF Castillo, P Rieben, R White, D TI FEMSTER: An object-oriented class library of high-order discrete differential forms SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE algorithms; H(div)- and H(curl)-conforming finite element methods; high-order finite element; computational electromagnetism; object-oriented programming ID FINITE-ELEMENT-METHOD; INTERPOLATORY VECTOR BASES; MAXWELLS EQUATIONS; NUMERICAL DISPERSION; POLLUTION ERROR; ELECTROMAGNETISM; VERSION; GRIDS; R3 AB FEMSTER is a modular finite element class library for solving three-dimensional problems arising in electromagnetism. The library was designed using a modern geometrical approach based on differential forms (or p-forms) and can be used for high-order spatial discretizations of well-known H(div)- and H(curl)-conforming finite element methods. The software consists of a set of abstract interfaces and concrete classes, providing a framework in which the user is able to add new schemes by reusing the existing classes or by incorporating new user-defined data types. C1 Univ Puerto Rico, Dept Math, Mayaguez, PR 00681 USA. Lawrence Livermore Natl Lab, Def Sci Engn Div, Livermore, CA 94551 USA. RP Castillo, P (reprint author), Univ Puerto Rico, Dept Math, Mayaguez Campus,POB 9018, Mayaguez, PR 00681 USA. EM castillo@math.uprm.edu; rieben1@lnl.gov; white37@llnl.gov NR 36 TC 23 Z9 23 U1 0 U2 7 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 USA SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD DEC PY 2005 VL 31 IS 4 BP 425 EP 457 DI 10.1145/1114268.1114269 PG 33 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 017ZM UT WOS:000235732500001 ER PT J AU Coates, L Beaven, G Erskine, PT Beale, SI Wood, SP Shoolingin-Jordan, PM Cooper, JB AF Coates, L Beaven, G Erskine, PT Beale, SI Wood, SP Shoolingin-Jordan, PM Cooper, JB TI Structure of Chlorobium vibrioforme 5-aminolaevulinic acid dehydratase complexed with a diacid inhibitor SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID X-RAY-STRUCTURE; PORPHOBILINOGEN SYNTHASE; ESCHERICHIA-COLI; MECHANISM; BIOSYNTHESIS; RESOLUTION; SITES AB The structure of Chlorobium vibrioforme 5-aminolaevulinic acid dehydratase (ALAD) complexed with the irreversible inhibitor 4,7-dioxosebacic acid has been solved. The inhibitor binds by forming Schiff-base linkages with lysines 200 and 253 at the active site. The structure reported here provides a definition of the interactions made by both of the substrate molecules (A-side and P-side substrates) with the C. vibrioforme ALAD and is compared and contrasted with structures of the same inhibitor bound to Escherichia coli and yeast ALAD. The structure suggests why 4,7-dioxosebacic acid is a better inhibitor of the zinc-dependent ALADs than of the zinc-independent ALADs. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Southampton, Sch Biol Sci, Southampton SO16 7PX, Hants, England. Brown Univ, Div Biol & Med, Providence, RI 02912 USA. RP Coates, L (reprint author), Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. EM lcoates@lanl.gov RI Wood, Stephen/B-1438-2009; OI Coates, Leighton/0000-0003-2342-049X NR 41 TC 4 Z9 5 U1 0 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD DEC PY 2005 VL 61 BP 1594 EP 1598 DI 10.1107/S0907444905030350 PN 12 PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 985QL UT WOS:000233392900005 PM 16304458 ER PT J AU Hatta, Y AF Hatta, Y TI Perturbative odderon in the color glass condensate SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 45th Cracow School of Theoretical Physics CY JUN 03-12, 2005 CL Zakopane, POLAND SP Jagellonian Univ, Inst Phys, Polish Acad Sci, Inst Nucl Phys, Univ Sci & Technol, Polish Acad Arts & Sci, Minist Natl Educ & Sport, Polish Minist Sci & Informat Soc Technologies ID GLUON DISTRIBUTION-FUNCTIONS; HIGH-ENERGY QCD; BFKL POMERON; LARGE NUCLEI; FIELD; SCATTERING; UNITARITY; EVOLUTION; MOMENTUM; EQUATION AB We derive small-x evolution equations for odderon exchange processes in the color glass condensate formalism. We consider the dipole-color glass scattering and the three-quark-color glass scattering, with particular emphasis on the gauge invariant coupling to the external probes. In the low energy regime where the classical gluon field is not so strong, our result is equivalent to the Bartels-Kwiecinski-Praszalowicz (BKP) equation. C1 Brookhaven Natl Lab, Dept Phys, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. NR 37 TC 0 Z9 0 U1 0 U2 1 PU JAGIELLONIAN UNIV PRESS PI KRAKOW PA UL MICHALOWSKIEGO 9-2, KRAKOW, 31126, POLAND SN 0587-4254 EI 1509-5770 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD DEC PY 2005 VL 36 IS 12 BP 3665 EP 3677 PG 13 WC Physics, Multidisciplinary SC Physics GA 999YR UT WOS:000234428600004 ER PT J AU Royon, C AF Royon, C TI Recent results from the Tevatron SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 45th Cracow School of Theoretical Physics CY JUN 03-12, 2005 CL Zakopane, POLAND SP Jagellonian Univ, Inst Phys, Polish Acad Sci, Inst Nucl Phys, Univ Sci & Technol, Polish Acad Arts & Sci, Minist Natl Educ & Sport, Polish Minist Sci & Informat Soc Technologies ID PRODUCTION CROSS-SECTION; HIGGS-BOSON PRODUCTION; PLUS JETS EVENTS; ROOT-S=1.96 TEV; P(P)OVER-BAR COLLISIONS; TOP-QUARK; RUN-II; LHC; POMERON; GLUONS AB In these lectures, we describe some recent results from the DO and CDF experiments at the Tevatron. C1 CEA Saclay, Serv Phys Particules, DAPNIA, F-91191 Gif Sur Yvette, France. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP CEA Saclay, Serv Phys Particules, DAPNIA, F-91191 Gif Sur Yvette, France. NR 56 TC 0 Z9 0 U1 0 U2 2 PU JAGIELLONIAN UNIV PRESS PI KRAKOW PA UL MICHALOWSKIEGO 9-2, KRAKOW, 31126, POLAND SN 0587-4254 EI 1509-5770 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD DEC PY 2005 VL 36 IS 12 BP 3697 EP 3722 PG 26 WC Physics, Multidisciplinary SC Physics GA 999YR UT WOS:000234428600007 ER PT J AU Hansson, AA Mortveit, HS Reidys, CM AF Hansson, AA Mortveit, HS Reidys, CM TI On asynchronous cellular automata SO ADVANCES IN COMPLEX SYSTEMS LA English DT Article DE sequential dynamical system; asynchronous cellular automaton; periodic point; phase space; update schedule invariance; invertibility ID SEQUENTIAL DYNAMICAL-SYSTEMS AB We study asynchronous cellular automata (ACA) induced by symmetric Boolean functions [1]. These systems can be considered as sequential dynamical systems (SDS) over words, a class of dynamical systems that consists of (a) a finite, labeled graph Y with vertex set {v(1),...,v(n)} and where each vertex v(i) has a state x(vi) in a finite field K, (b) a sequence of functions (F-vi,Y)(i), and (c) a word w = (w(1),...,w(k)), where each w(i) is a vertex in Y. The function F-vi,Y updates the state of vertex v(i) as a function of the state of v(i) and its Y-neighbors and maps all other vertex states identically. The SDS is the composed map [FY, w] Pi(i=1)(k) F-wi : K-n --> K-n. In the particular case of ACA, the graph is the circle graph on n vertices (Y Circ(n)), and all the maps F-vi are induced by a common Boolean function. Our main result is the identification of all w-independent ACA, that is, all ACA with periodic points that are independent of the word (update schedule) w. In general, for each w-independent SDS, there is a finite group whose structure contains information about for example SDS with specific phase space properties. We classify and enumerate the set of periodic points for all w-independent ACA, and we also compute their associated groups in the case of Y = Circ(4). Finally, we analyze invertible ACA and offer an interpretation Of S-35 as the group of an SDS over the three-dimensional cube with local functions induced by nor(3) + nand(3). C1 Los Alamos Natl Lab, CCS DSS, Los Alamos, NM 87545 USA. Virginia Polytech Inst & State Univ, Dept Math, VBI, Blacksburg, VA 24061 USA. RP Hansson, AA (reprint author), Los Alamos Natl Lab, CCS DSS, Los Alamos, NM 87545 USA. EM hansson@lanl.gov; henning@vt.edu; duck@santafe.edu NR 11 TC 8 Z9 8 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-5259 J9 ADV COMPLEX SYST JI Adv. Complex Syst. PD DEC PY 2005 VL 8 IS 4 BP 521 EP 538 DI 10.1142/S0219525905000555 PG 18 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 008UK UT WOS:000235066000010 ER PT J AU Norman, MR Pines, D Kallin, C AF Norman, MR Pines, D Kallin, C TI The pseudogap: friend or foe of high T-c? SO ADVANCES IN PHYSICS LA English DT Review ID HIGH-TEMPERATURE SUPERCONDUCTORS; COPPER-OXIDE SUPERCONDUCTORS; QUANTUM CRITICAL-BEHAVIOR; ELECTRONIC SPECIFIC-HEAT; INPLANE SPECTRAL WEIGHT; VALENCE BOND STATE; CUPRATE SUPERCONDUCTORS; UNDERDOPED BI2SR2CACU2O8+DELTA; HIGH-T(C) SUPERCONDUCTORS; PHASE COHERENCE AB Although nineteen years have passed since the discovery of high temperature cuprate superconductivity [ 1], there is still no consensus on its physical origin. This is in large part because of a lack of understanding of the state of matter out of which the superconductivity arises. In optimally and underdoped materials, this state exhibits a pseudogap at temperatures large compared to the superconducting transition temperature [ 2, 3]. Although discovered only three years after the pioneering work of Bednorz and Muller, the physical origin of this pseudogap behavior and whether it constitutes a distinct phase of matter is still shrouded in mystery. In the summer of 2004, a band of physicists gathered for five weeks at the Aspen Center for Physics to discuss the pseudogap. In this perspective, we would like to summarize some of the results presented there and discuss the importance of the pseudogap phase in the context of strongly correlated electron systems. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Los Alamos Natl Lab, Inst Complex Adapt Matter, Los Alamos, NM 87574 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. RP Norman, MR (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM norman@anl.gov RI Norman, Michael/C-3644-2013 NR 106 TC 320 Z9 322 U1 11 U2 87 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0001-8732 J9 ADV PHYS JI Adv. Phys. PD DEC PY 2005 VL 54 IS 8 BP 715 EP 733 DI 10.1080/00018730500459906 PG 19 WC Physics, Condensed Matter SC Physics GA 003KV UT WOS:000234681500002 ER PT J AU Denef, F Douglas, MR Florea, B Grassi, A Kachru, S AF Denef, Frederik Douglas, Michael R. Florea, Bogdan Grassi, Antonella Kachru, Shamit TI Fixing all moduli in a simple F-theory compactification SO ADVANCES IN THEORETICAL AND MATHEMATICAL PHYSICS LA English DT Review ID ENHANCED GAUGE SYMMETRIES; BREAKING SOFT TERMS; SUPERSYMMETRY BREAKING; CALABI-YAU; STRING THEORY; D-BRANES; GRAVITATIONAL COUPLINGS; IIB ORIENTIFOLDS; I VACUA; N=1 AB We discuss a simple example of an F-theory compactification on a Calabi-Yau fourfold where background fluxes, non-perturbative effects from Euclidean D3-instantons, and gauge dynamics on D7-branes allow us to. x all closed and open string moduli. We explicitly check that the known higher-order corrections to the potential, which we neglect in our leading approximation, only shift the results by a small amount. In our exploration of the model, we encounter interesting new phenomena, including examples of transitions where D7-branes absorb O3-planes, while changing topology to preserve the net D3 charge. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Inst Hautes Etud Sci, F-91440 Bures Sur Yvette, France. Univ Penn, Dept Math, Philadelphia, PA 19104 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford, CA 94305 USA. RP Denef, F (reprint author), Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. EM denef@physics.rutgers.edu; mrd@physics.rutgers.edu; florea@physics.rutgers.edu; grassi@math.upenn.edu; skachru@stanford.edu NR 110 TC 70 Z9 70 U1 0 U2 0 PU INT PRESS PI SOMERVILLE PA PO BOX 43502, SOMERVILLE, MA 02143 USA SN 1095-0761 J9 ADV THEOR MATH PHYS JI Adv. Theor. Math. Phys. PD DEC PY 2005 VL 9 IS 6 BP 861 EP 929 PG 69 WC Physics, Particles & Fields; Physics, Mathematical SC Physics GA 087MB UT WOS:000240745400001 ER PT J AU Mazaheri, AR Zerai, B Ahmadi, G Kadambi, JR Saylor, BZ Oliver, M Bromhal, GS Smith, DH AF Mazaheri, AR Zerai, B Ahmadi, G Kadambi, JR Saylor, BZ Oliver, M Bromhal, GS Smith, DH TI Computer simulation of flow through a lattice flow-cell model SO ADVANCES IN WATER RESOURCES LA English DT Article DE flow cell; pore-scale model; muliphase flows; porous media ID PARTICLE IMAGE VELOCIMETRY; POROUS-MEDIA; BOLTZMANN METHOD; PORE-SCALE; GEOMETRIES; PRESSURE; DRAINAGE; FLUIDS AB For single-phase flow through a network model of a porous medium, we report (1) solutions of the Navier-Stokes equation for the flow, (2) micro-particle imaging velocimetry (PIV) measurements of local flow velocity vectors in the "pores throats" and "pore bodies," and (3) comparisons of the computed and measured velocity vectors. A "two-dimensional" network of cylindrical pores and parallelepiped connecting throats was constructed and used for the measurements. All pore bodies had the same dimensions, but three-different (square cross-section) pore-throat sizes were randomly distributed throughout the network. An unstructured computational grid for flow through an identical network was developed and used to compute the local pressure gradients and flow vectors for several different (macroscopic) flow rates. Numerical solution results were compared with the experimental data, and good agreement was found. Cross-over from Darcy flow to inertial flow was observed in the computational results, and the permeability and inertia coefficients of the network were estimated. The development of inertial flow was seen as a "two-step" process: (1) recirculation zones appeared in more and more pore bodies as the flow rate was increased, and (2) the strengths of individual recirculation zones increased with flow rate. Because each pore-throat and pore-body dimension is known, in this approach an experimental (and/or computed) local Reynolds number is known for every location in the porous medium at which the velocity has been measured (and/or computed). (c) 2004 Elsevier Ltd. All rights reserved. C1 Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. US DOE, Natl Engn Technol Lab, Morgantown, WV 26507 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Ahmadi, G (reprint author), Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. EM ahmadi@clarkson.edu OI Saylor, Beverly/0000-0002-1825-8953 NR 38 TC 9 Z9 10 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD DEC PY 2005 VL 28 IS 12 BP 1267 EP 1279 DI 10.1016/j.advwatres.2004.10.016 PG 13 WC Water Resources SC Water Resources GA 982SX UT WOS:000233183000001 ER PT J AU Park, E Parker, JC AF Park, E Parker, JC TI Evaluation of an upscaled model for DNAPL dissolution kinetics in heterogeneous aquifers SO ADVANCES IN WATER RESOURCES LA English DT Article DE DNAPL; upscaling; mass transfer kinetics; groundwater ID NONAQUEOUS PHASE LIQUID; SATURATED POROUS-MEDIA; STATE MASS-TRANSFER; UNIFORM-FLOW FIELDS; SUBSURFACE SYSTEMS; MULTIPHASE FLOW; TRANSFER RATES; TETRACHLOROETHYLENE; REMEDIATION; GROUNDWATER AB Estimates of contaminant fluxes from DNAPL sources as a function of time and DNAPL mass reduction are important to assess the long-term sustainability and costs of monitored natural attenuation and to determine the benefits of partial source removal. We investigate the accuracy of the upscaled mass transfer function (MTF) proposed by Parker and Park [Parker JC, Park E. Modeling field-scale dense nonaqueous phase liquid dissolution kinetics in heterogeneous aquifers. WRR 2004;40:WO5109] to describe field-scale dissolved phase fluxes from DNAPL sources for a range of scenarios generated using high-resolution 3-D numerical simulations of DNAPL infiltration and long-term dissolved phase transport. The results indicate the upscaled MTF is capable of accurately describing field-scale DNAPL dissolution rates as a function of time. For finger-dominated source regions, an empirical mass depletion exponent in the MTF takes on values greater than one which results in predicted mass flux rates that decrease continuously with diminishing DNAPL mass over time. Lens-dominated regions exhibit depletion exponents less than one, which results in more step-function like mass flux versus time behavior. Mass fluxes from DNAPL sources exhibiting both lens- and finger-dominated subregions were less accurately described by the simple MTF, but were well described by a dual-continuum model of the same form for each subregion. The practicality of calibrating a dual-continuum model will likely depend on the feasibility of obtaining spatially resolved field measurements of contaminant fluxes or concentrations associated with the subregions using multilevel sampling or some other means. (c) 2005 Elsevier Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Parker, JC (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. EM egpark@knu.ac.kr; parkerjc@ornl.gov NR 24 TC 33 Z9 34 U1 1 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD DEC PY 2005 VL 28 IS 12 BP 1280 EP 1291 DI 10.1016/j.advwatres.2005.04.002 PG 12 WC Water Resources SC Water Resources GA 982SX UT WOS:000233183000002 ER PT J AU Hong, L Gritti, F Guiochon, G Kaczmarski, K AF Hong, L Gritti, F Guiochon, G Kaczmarski, K TI Rate constants of mass transfer kinetics in reversed phase liquid chromatography SO AICHE JOURNAL LA English DT Article DE liquid chromatography; mass transfer kinetics; method of moments; pore diffusion; surface diffusion ID BEDS; DISPERSION; PROFILES; POROSITY; COLUMNS AB The parameters of the kinetics of mass transfer of several n-alkylbenzenes were measured by the method of moments on a series of columns prepared with different samples of the same RPLC packing material having widely different average particle diameters, from 3 to 50 mu m. These data were analyzed using the available models, and correlations. The best agreement between experimental and theoretical data was obtained under the assumption that the rate constant for the external mass transfer increases with increasing average particle size, an unexpected conclusion. It was also shown that the interpretation of the relative importance of the roles of pore diffusivity and surface diffusivity in the internal mass transfer kinetics is somewhat ambiguous and that the conclusion to be drawn from experimental results depends on the assumptions made regarding and the average particle regarding the tortuosity model and the relationship between k(ext) size. (c) 2005 American Institute of Chemical Engineers. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Rzeszow Univ Technol, Fac Chem, PL-35959 Rzeszow, Poland. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 23 TC 17 Z9 17 U1 0 U2 4 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD DEC PY 2005 VL 51 IS 12 BP 3122 EP 3133 DI 10.1002/aic.10565 PG 12 WC Engineering, Chemical SC Engineering GA 985TO UT WOS:000233401800009 ER PT J AU Yu, D Sipos, T Wu, MM Naleway, C AF Yu, D Sipos, T Wu, MM Naleway, C TI Remineralization potential of an anticaries/antigingivitis mouthrinse SO AMERICAN JOURNAL OF DENTISTRY LA English DT Article ID SODIUM-FLUORIDE; ENAMEL; CARIES; CALCIUM AB Purpose: To assess the ability of a new formulation (Listerine with 0.022% NaF) to remineralize initially decalcified bovine enamel compared to a positive control, clinically established 0.022% NaF rinse. Methods: A cyclic demineralization/remineralization in vitro model was utilized and the level of remineralization was monitored by examining the Knoop microhardness over 6 and 18 D/T/R cycles Results: (1) both the test formulation and positive control rinses were statistically significantly effective in remineralizing artificial lesions in vitro; and (2) the test formulation performed "at least as good as" the positive control. These results support the concept that the remineralization potential of the fluoride rinse is not adversely affected by the addition of essential oils. C1 Pfizer Inc, Consumer Healthcare R&D, Morris Plains, NJ USA. Digest Care Inc, Bethesda, MD USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Yu, D (reprint author), 170 Tabor Rd, Morris Plains, NJ 07950 USA. EM Duncan.yu@pfizer.com NR 15 TC 0 Z9 0 U1 0 U2 0 PU MOSHER & LINDER, INC PI WESTON PA 318 INDIAN TRACE #500, WESTON, FL 33326 USA SN 0894-8275 J9 AM J DENT JI Am. J. Dent. PD DEC PY 2005 VL 18 IS 6 BP 361 EP 364 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 022VN UT WOS:000236084300013 PM 16433408 ER PT J AU Adler, RJ Bjorken, JD Chen, P Liu, JS AF Adler, RJ Bjorken, JD Chen, P Liu, JS TI Simple analytical models of gravitational collapse SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID UNCERTAINTY PRINCIPLE; PARTICLE; GRAVITY AB Most general relativity textbooks devote considerable attention to the simplest example of a black hole containing a singularity, the Schwarzschild geometry. Only a few discuss the dynamical process of gravitational collapse by which black holes and singularities form. We present two simple analytical models that describe this process. The first involves collapsing spherical shells of light and is analyzed mainly in Eddington-Finkelstein coordinates; the second involves collapsing spheres filled with a perfect fluid and is analyzed mainly in Painleve-Gullstrand coordinates. Our main goal is simplicity and algebraic completeness, but we also present a few more sophisticated results such as the collapse of a light shell in Kruskal-Szekeres coordinates. (c) 2005 American Association of Physics Teachers. C1 Stanford Univ, Hansen Lab Expt Phys, Stanford, CA 94309 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RP Adler, RJ (reprint author), Stanford Univ, Hansen Lab Expt Phys, Stanford, CA 94309 USA. EM adier@relgyro.stanford.edu NR 36 TC 18 Z9 18 U1 0 U2 2 PU AMER ASSOC PHYSICS TEACHERS AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD DEC PY 2005 VL 73 IS 12 BP 1148 EP 1159 DI 10.1119/1.2117187 PG 12 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 995KP UT WOS:000234099500009 ER PT J AU Li, FL Robinson, H Yeung, E AF Li, FL Robinson, H Yeung, E TI Automated high-throughput nanoliter-scale protein crystallization screening SO ANALYTICAL AND BIOANALYTICAL CHEMISTRY LA English DT Article DE protein; crystallization; native fluorescence; high-throughput screening ID VAPOR-DIFFUSION; STRUCTURAL GENOMICS; BIOLOGICAL MACROMOLECULES; CONTROLLING NUCLEATION; CRYSTAL-GROWTH; CRYSTALLOGRAPHY; ELECTROPHORESIS; DISCOVERY; DESIGN; ARRAY AB A highly efficient method is developed for automated high-throughput screening of nanoliter-scale protein crystallization. The system integrates liquid dispensing, crystallization and detection. The automated liquid dispensing system handles nanoliters of protein and various combinations of precipitants in parallel to access diverse regions of the phase diagram. A new detection scheme, native fluorescence, with complementary visible-light detection is employed for monitoring the progress of crystallization. This detection mode can distinguish protein crystals from inorganic crystals in a nondestructive manner. A gas-permeable membrane covering the microwells simplifies evaporation rate control and probes extended conditions in the phase diagram. The system was successfully demonstrated for the screening of lysozyme crystallization under 81 different conditions. C1 Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Brookhaven Natl Lab, Biol Dept, Upton, NY 11973 USA. RP Yeung, E (reprint author), Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. EM yeung@ameslab.gov NR 29 TC 7 Z9 9 U1 1 U2 3 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1618-2642 J9 ANAL BIOANAL CHEM JI Anal. Bioanal. Chem. PD DEC PY 2005 VL 383 IS 7-8 BP 1034 EP 1041 DI 10.1007/s00216-005-0165-8 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 992HQ UT WOS:000233875400003 PM 16283260 ER PT J AU Narasimhan, C Tabb, DL VerBerkmoes, NC Thompson, MR Hettich, RL Uberbacher, EC AF Narasimhan, C Tabb, DL VerBerkmoes, NC Thompson, MR Hettich, RL Uberbacher, EC TI MASPIC: Intensity-based tandem mass spectrometry scoring scheme that improves peptide identification at high confidence SO ANALYTICAL CHEMISTRY LA English DT Article ID PROTEIN IDENTIFICATION; SEQUENCE DATABASES; SPECTRAL DATA; QUANTITATIVE-ANALYSIS; SHOTGUN PROTEOMICS; ALGORITHM; SEARCH; MS/MS; MODEL; FRAGMENTATION AB Algorithmic search engines bridge the gap between large tandem mass spectrometry data sets and the identification of proteins associated with biological samples. Improvements in these tools can greatly enhance biological discovery. We present a new scoring scheme for comparing tandem mass spectra with a protein sequence database. The MASPIC (Multinomial Algorithm for Spectral Profile-based Intensity Comparison) scorer converts an experimental tandem mass spectrum into a m/z profile of probability and then scores peak lists from potential candidate peptides using a multinomial distribution model. The MASPIC scoring scheme incorporates intensity, spectral peak density variations, and m/z error distribution associated with peak matches into a multinomial distribution. The scoring scheme was validated on two standard protein mixtures and an additional set of spectra collected on a complex ribosomal protein mixture from Rhodopseudomonas palustris. The results indicate a 5-15% improvement over Sequest for high-confidence identifications. The performance gap grows as sequence database size increases. Additional tests on spectra from proteinase-K digest data showed similar performance improvements demonstrating the advantages in using MASPIC for studying proteins digested with less specific proteases. All these investigations show MASPIC to be a versatile and reliable system for peptide tandem mass spectral identification. C1 Univ Tennessee, Oak Ridge Natl Lab, Grad Sch Genome Sci & Technol, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Narasimhan, C (reprint author), Univ Tennessee, Oak Ridge Natl Lab, Grad Sch Genome Sci & Technol, 1060 Commerce Pk, Oak Ridge, TN 37830 USA. EM narasimhanc@ornl.gov RI Hettich, Robert/N-1458-2016 OI Hettich, Robert/0000-0001-7708-786X NR 43 TC 34 Z9 34 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 1 PY 2005 VL 77 IS 23 BP 7581 EP 7593 DI 10.1021/ac0501745 PG 13 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900022 PM 16316165 ER PT J AU Liau, A Karnik, R Majumdar, A Cate, JHD AF Liau, A Karnik, R Majumdar, A Cate, JHD TI Mixing crowded biological solutions in milliseconds SO ANALYTICAL CHEMISTRY LA English DT Article ID LIQUID INTERFACES; MICROFLUIDIC SYSTEM; PROTEIN ADSORPTION; KINETICS; TENSION; SURFACTANTS; DROPLETS; BOVINE; DROPS; MEDIA AB In vitro studies of biological reactions are rarely performed in conditions that reflect their native intracellular environments where macromolecular crowding can drastically change reaction rates. Kinetics experiments require reactants to be mixed on a time scale faster than that of the reaction. Unfortunately, highly concentrated solutions of crowding agents such as bovine serum albumin and hemoglobin that are viscous and sticky are extremely difficult to mix rapidly. We demonstrate a new droplet-based microfluidic mixer that induces chaotic mixing of crowded solutions in milliseconds due to protrusions of the microchannel walls that generate oscillating interfacial shear within the droplets. Mixing in the microfluidic mixer is characterized, mechanisms underlying mixing are discussed, and evidence of biocompatibility is presented. This microfluidic platform will allow for the first kinetic studies of biological reactions with millisecond time resolution under conditions of macromolecular crowding similar to those within cells. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Biophys Program, Dept Mech Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Cate, JHD (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. EM jcate@lbl.gov NR 29 TC 74 Z9 77 U1 4 U2 28 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 DEC 1 PY 2005 VL 77 IS 23 BP 7618 EP 7625 DI 10.1021/ac050827h PG 8 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900026 PM 16316169 ER PT J AU Yan, XM Zhong, WW Tang, AJ Schielke, EG Hang, W Nolan, JP AF Yan, XM Zhong, WW Tang, AJ Schielke, EG Hang, W Nolan, JP TI Multiplexed flow cytometric immunoassay for influenza virus detection and differentiation SO ANALYTICAL CHEMISTRY LA English DT Article ID SUSPENSION ARRAY TECHNOLOGY; B VIRUSES; INFECTIOUS-DISEASES; HUMAN CYTOKINES; DIAGNOSIS; ASSAYS; QUANTIFICATION; ENCEPHALITIS; QUANTITATION; EVOLUTION AB Microsphere-based immunoassay by flow cytometry has gained popularity lately in protein detection and infectious disease diagnosis due to its capacity for multiplexed analysis and simple assay format. Here, we demonstrated the power of microsphere-based immunoassay for high-sensitivity detection and accurate differentiation of influenza viruses. The effects of sample volume and bead number on the assay sensitivity of viral antigen detection were studied. Compared to enzyme-linked immunosorbent assays, flow-based bead assays provided similar to 10-fold lower detection limit for viral particle detection and performed similarly for recombinant viral hemagglutinin protein detection. A four-plexed assay for influenza virus typing and influenza B virus sublineage characterization was developed to demonstrate the potential for multiplexed viral antigen detection and differentiation. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Jolla Bioengn Inst, La Jolla, CA 92037 USA. RP Yan, XM (reprint author), Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. EM xmyan@xmu.edu.cn FU NCRR NIH HHS [RR01315]; NIBIB NIH HHS [R01 EB003824-01, R01 EB003824] NR 34 TC 31 Z9 37 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 DEC 1 PY 2005 VL 77 IS 23 BP 7673 EP 7678 DI 10.1021/ac0508797 PG 6 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900032 PM 16316175 ER PT J AU Pierce, KM Wood, LF Wright, BW Synovec, RE AF Pierce, KM Wood, LF Wright, BW Synovec, RE TI A comprehensive two-dimensional retention time alignment algorithm to enhance chemometric analysis of comprehensive two-dimensional separation data SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; PRINCIPAL COMPONENT ANALYSIS; FLIGHT MASS-SPECTROMETRY; GAS-CHROMATOGRAPHY; QUANTITATIVE-ANALYSIS; X GC; AUTOMATED INSTRUMENTATION; PROTEOME ANALYSIS; PEAK ALIGNMENT; ELECTROPHORESIS AB A comprehensive two-dimensional (21)) retention time alignment algorithm was developed using a novel indexing scheme. The algorithm is termed comprehensive because it functions to correct the entire chromatogram in both dimensions and it preserves the separation information in both dimensions. Although the algorithm is demonstrated by correcting comprehensive two-dimensional gas chromatography (GC x GC) data, the algorithm is designed to correct shifting in all forms of 2D separations, such as LC x LC, LC x CE, CE x CE, and LC x GC. This 2D alignment algorithm was applied to three different data sets composed of replicate GC x GC separations of (1) three 22-component control mixtures, (2) three gasoline samples, and (3) three diesel samples. The three data sets were collected using slightly different temperature or pressure programs to engender significant retention time shifting in the raw data and then demonstrate subsequent corrections of that shifting upon comprehensive 2D alignment of the data sets. Thirty 12-min GC x GC separations from three 22-component control mixtures were used to evaluate the 2D alignment performance (10 runs/mixture). The average standard deviation of first column retention time improved 5-fold from 0.020 min (before alignment) to 0.004 min (after alignment). Concurrently, the average standard deviation of second column retention time improved 4-fold from 3.5 ms (before alignment) to 0.8 ms (after alignment). Alignment of the 30 control mixture chromatograms took 20 min. The quantitative integrity of the GC x GC data following 2D alignment was also investigated. The mean integrated signal was determined for all components in the three 22-component mixtures for all 30 replicates. The average percent difference in the integrated signal for each component before and after alignment was 2.6%. Singular value decomposition (SVD) was applied to the 22-component control mixture data before and after alignment to show the restoration of trilinearity to the data, since trilinearity benefits chemometric analysis. By applying comprehensive 2D retention time alignment to all three data sets (control mixtures, gasoline samples, and diesel samples), classification by principal component analysis (PCA) substantially improved, resulting in 100% accurate scores clustering. C1 Univ Washington, Dept Chem, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Synovec, RE (reprint author), Univ Washington, Dept Chem, Box 351700, Seattle, WA 98195 USA. EM synovec@chem.washington.edu OI Wood, Lianna/0000-0001-9531-5627 NR 40 TC 91 Z9 91 U1 1 U2 37 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 DEC 1 PY 2005 VL 77 IS 23 BP 7735 EP 7743 DI 10.1021/ac0511142 PG 9 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900040 PM 16316183 ER PT J AU Shen, YF Strittmatter, EF Zhang, R Metz, TO Moore, RJ Li, FM Udseth, HR Smith, RD Unger, KK Kumar, D Lubda, D AF Shen, YF Strittmatter, EF Zhang, R Metz, TO Moore, RJ Li, FM Udseth, HR Smith, RD Unger, KK Kumar, D Lubda, D TI Making broad proteome protein measurements in 1-5 min using high-speed RPLC separations and high-accuracy mass measurements SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY LIQUID-CHROMATOGRAPHY; ION-CYCLOTRON RESONANCE; SPECTROMETRY; MS/MS; ACCUMULATION; PEPTIDE; MS AB The throughput of proteomics measurements that provide broad protein coverage is limited by the quality and speed of both the separations as well as the subsequent mass spectrometric analysis; at present, analysis times can range anywhere from hours (high throughput) to days or longer (low throughput). We have explored the basis for proteomics analyses conducted on the order of minutes using high-speed capillary RPLC combined through online electrospray ionization interface with high-accuracy mass spectrometry (MS) measurements. Short 0.8-mu m porous C18 particle-packed 50-mu m-i.d. capillaries were used to speed the RPLC separations while still providing high-quality separations. Both time-of-flight (TOF) and Fourier transform ion cyclotron resonance (FTICR) MS were applied for identiying peptides using the accurate mass and time (AMT) tag approach. Peptide RPLC relative retention (elution) times that were generated by solvent gradients that differed by at least 25-fold were found to provide relative elution times that agreed to within 5%, which provides the basis for using peptide AMT tags for higher throughput proteomics measurements. For fast MS acquisition speeds (e.g., 0.2 s for TOF and either similar to 0.3 or similar to 0.6 s for FTICR), peptide mass measurement accuracies of better than +/- 15 ppm were obtained with the highspeed RPLC separations. The ability to identify peptides and the overall proteome coverage was determined by factors that include the separation peak capacity, the sensitivity of the MS (with fast scanning), and the accuracy of both the mass measurements and the relative RPLC peptide elution times. The experimental RPLC relative elution time accuracies of 5% (using high-speed capillary RPLC) and mass measurement accuracies of better than +/- 15 ppm allowed for the confident identification of > 2800 peptides and > 760 proteins from > 13 000 different putative peptides detected from a Shewanella oneidensis tryptic digest. Initial results for both RPLC-ESI-TOF and RPLC-ESI-FTICR MS were similar, with similar to 2000 different peptides from similar to 600 different proteins identified within 2-3 min. For < 120-s proteomic analysis, TOF MS analyses were more effective, while FTICR MS was more effective for the > 150-s analysis due to the improved mass accuracies attained using longer spectrum acquisition times. C1 Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. Univ Mainz, Inst Anorgan Chem & Analyt Chem, D-55099 Mainz, Germany. Merck KGaA, Life Sci Analyt, D-64271 Darmstadt, Germany. RP Shen, YF (reprint author), Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Metz, Tom/0000-0001-6049-3968; Smith, Richard/0000-0002-2381-2349 FU NCRR NIH HHS [RR18522] NR 18 TC 27 Z9 27 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 1 PY 2005 VL 77 IS 23 BP 7763 EP 7773 DI 10.1021/ac051257o PG 11 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900044 PM 16316187 ER PT J AU Wabuyele, MB Vo-Dinh, T AF Wabuyele, MB Vo-Dinh, T TI Detection of human immunodeficiency virus type 1 DNA sequence using plasmonics nanoprobes SO ANALYTICAL CHEMISTRY LA English DT Article ID SURFACE-ENHANCED RAMAN; MOLECULAR BEACONS; SILVER ELECTRODE; P24 ANTIGEN; PCR ASSAY; INFECTION; SCATTERING; RNA; PLASMA; PROBES AB This paper describes the use of plasmonics-based nanoprobes that act as molecular sentinels for DNA diagnostics. The plasmonics nanoprobe comprises a metal nanoparticle and a stem-loop DNA molecule tagged with a Raman label. The nanoprobe utilizes the specificity and selectivity of the DNA hairpin probe sequence to detect a specific target DNA sequence of interest. In the absence of target DNA, the stem-loop configuration maintains the Raman label in proximity to the metal nanoparticle, inducing an intense surface-enhanced Raman scattering (SERS) effect that produces a strong Raman signal upon laser excitation. Upon hybridization of a complementary target DNA sequence to the nanoprobe, the stem-loop configuration is disrupted, causing the Raman label to physically separate from the metal nanoparticle, thus quenching the SERS signal. The usefulness and potential application of the plasmonics nanoprobe for diagnosis is demonstrated using the gag gene sequence of the human immunodeficiency virus type 1 (HIV-1). We successfully demonstrated the specificity and selectivity of the plasmonics nanoprobes to detect PCR amplicons of the HIV gene. The potential for combining the spectral selectivity and high sensitivity of the SERS process with inherent molecular specificity of DNA hairpins to diagnose molecular target sequences in homogeneous solutions is discussed. C1 Oak Ridge Natl Lab, Ctr Adv Biomed Photon, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Ctr Adv Biomed Photon, POB 2008, Oak Ridge, TN 37831 USA. EM vodinht@ornl.gov NR 34 TC 146 Z9 149 U1 10 U2 71 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 DEC 1 PY 2005 VL 77 IS 23 BP 7810 EP 7815 DI 10.1021/ac0514671 PG 6 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900049 PM 16316192 ER PT J AU Bohlke, JK Sturchio, NC Gu, BH Horita, J Brown, GM Jackson, WA Batista, J Hatzinger, PB AF Bohlke, JK Sturchio, NC Gu, BH Horita, J Brown, GM Jackson, WA Batista, J Hatzinger, PB TI Perchlorate isotope forensics SO ANALYTICAL CHEMISTRY LA English DT Letter ID FRACTIONATION; NITRATE; WATER; CHLORINE; REDUCTION; EXCHANGE; ORIGIN; SYSTEM AB Perchlorate has been detected recently in a variety of soils, waters, plants, and food products at levels that may be detrimental to human health. These discoveries have generated considerable interest in perchlorate source identification. In this study, comprehensive stable isotope analyses (Cl-37/Cl-35 and O-18/O-17/O-16) of perchlorate from known synthetic and natural sources reveal systematic differences in isotopic characteristics that are related to the formation mechanisms. In addition, isotopic analyses of perchlorate extracted from groundwater and surface water demonstrate the feasibility of identifying perchlorate sources in contaminated environments on the basis of this technique. Both natural and synthetic sources of perchlorate have been identified in water samples from some perchlorate occurrences in the United States by the isotopic method. C1 US Geol Survey, Natl Ctr 431, Reston, VA 20192 USA. Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37381 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37381 USA. Texas Tech Univ, Dept Civil Engn, Lubbock, TX 79409 USA. Univ Nevada, Dept Civil & Environm Engn, Las Vegas, NV 89154 USA. Shaw Environm, Lawrenceville, NJ 08648 USA. RP Bohlke, JK (reprint author), US Geol Survey, Natl Ctr 431, Reston, VA 20192 USA. EM jkbohlke@usgs.gov RI Jackson, William/B-8999-2009; Gu, Baohua/B-9511-2012 OI Gu, Baohua/0000-0002-7299-2956 NR 35 TC 48 Z9 57 U1 2 U2 31 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 DEC 1 PY 2005 VL 77 IS 23 BP 7838 EP 7842 DI 10.1021/ac051360d PG 5 WC Chemistry, Analytical SC Chemistry GA 991BA UT WOS:000233785900053 PM 16316196 ER PT J AU Einstein, DR Freed, AD Stander, N Fata, B Vesely, I AF Einstein, DR Freed, AD Stander, N Fata, B Vesely, I TI Inverse parameter fitting of biological tissues: A response surface approach SO ANNALS OF BIOMEDICAL ENGINEERING LA English DT Article; Proceedings Paper CT International Biofluids Mechanics Symposium CY DEC 12-14, 2003 CL Pasadena, CA SP US Natl Comm Biomech, Biomed Engn Soc, Int Federat Med & Biol Engn DE LS-OPT; nonlinear continuum mechanics; finite element analysis ID FINITE-ELEMENT CHARACTERIZATION; SOFT-TISSUES; OPTIMIZATION AB In this paper, we present the application of a semiglobal inverse method for determining material parameters of biological tissues. The approach is based on the successive response surface method, and is illustrated by fitting constitutive parameters to two nonlinear anisotropic constitutive equations, one for aortic sinus and aorticwall, the other for aortic valve tissue. Material test data for the aortic sinus consisted of two independent orthogonal uniaxial tests. Material test data for the aortic valve was obtained from a dynamic inflation test. In each case, a numerical simulation of the experiment was performed and predictions were compared to the real data. For the uniaxial test simulation, the experimental targets were force at a measured displacement. For the inflation test, the experimental targets were the three-dimensional coordinates of material markers at a given pressure. For both sets of tissues, predictions with converged parameters showed excellent agreement with the data, and we found that the method was able to consistently identify model parameters. We believe the method will find wide application in biomedical material characterization and in diagnostic imaging. C1 Pacific NW Normal Lab, Richland, WA 99354 USA. NASA, John H Glenn Res Ctr, Biosci & Technol Branch, Cleveland, OH USA. Livermore Software Technol Corp, Livermore, CA USA. Univ So Calif, Dept Biomed Engn, Los Angeles, CA 90089 USA. Univ So Calif, Keck Sch Med, Los Angeles, CA USA. Childrens Hosp Los Angeles, Los Angeles, CA 90027 USA. RP Pacific NW Normal Lab, 790 6th St,MS P7-56, Richland, WA 99354 USA. EM daniel.einstein@pnl.gov OI Freed, Alan/0000-0002-3492-0628 NR 21 TC 18 Z9 18 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-6964 EI 1573-9686 J9 ANN BIOMED ENG JI Ann. Biomed. Eng. PD DEC PY 2005 VL 33 IS 12 BP 1819 EP 1830 DI 10.1007/s10439-005-8338-3 PG 12 WC Engineering, Biomedical SC Engineering GA 999NC UT WOS:000234395300020 PM 16389530 ER PT J AU Smith, AB AF Smith, AB TI Fast-neutrons incident on rotors: Tantalum SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID REFORMULATED OPTICAL MODEL; ELASTIC-SCATTERING; FINITE NUCLEI; DEPENDENCE; DISTRIBUTIONS; STATES AB Mono-energetic neutrons are elastically and inelastically scattered from elemental tantalum at incident energies of approximate to 0.3-10.0 MeV. These experimental results are augmented with neutron total-cross-section and additional neutron-scattering data from the literature to form a composite experimental database. The latter is interpreted in the context of optical-statistical and coupled-channels models, including consideration of collective rotations, dispersion effects and other physical properties. The results are compared with those of similar processes in this region of collective nuclei. A regional model is proposed for the interpretation and prediction of such interactions. The model and the experimental results are compared with corresponding values given in ENDF/B-VI. (C) 2005 Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Nucl Engn Div, Argonne, IL 60439 USA. Physicists Consultat, Ottawa, IL USA. RP Smith, AB (reprint author), Argonne Natl Lab, Nucl Engn Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM abowensmith@earthlink.net NR 60 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD DEC PY 2005 VL 32 IS 18 BP 1926 EP 1952 DI 10.1016/j.anucene.2005.02.014 PG 27 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 995KI UT WOS:000234098800004 ER PT J AU Taghavi, S Barac, T Greenberg, B Borremans, B Vangronsveld, J van der Lelie, D AF Taghavi, S Barac, T Greenberg, B Borremans, B Vangronsveld, J van der Lelie, D TI Horizontal gene transfer to endogenous endophytic bacteria from poplar improves phytoremediation of toluene SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID RESISTANCE; DEAMINASE; PLASMID AB Poplar, a plant species frequently used for phytoremediation of groundwater contaminated with organic solvents, was inoculated with the endophyte Burkholderia cepacia VM1468. This strain, whose natural host is yellow lupine, contains the pTOM-Bu61 plasmid coding for constitutively expressed toluene degradation. Noninoculated plants or plants inoculated with the soil bacterium B. cepacia Bu61 (pTOM-Bu61) were used as controls. Inoculation of poplar had a positive effect on plant growth in the presence of toluene and reduced the amount of toluene released via evapotranspiration. These effects were more dramatic for VM1468, the endophytic strain, than for Bu61. Remarkably, none of the strains became established at detectable levels in the endophytic community, but there was horizontal gene transfer of pTOM-Bu61 to different members of the endogenous endophytic community, both in the presence and in the absence of toluene. This work is the first report of in planta horizontal gene transfer among plant-associated endophytic bacteria and demonstrates that such transfer could be used to change natural endophytic microbial communities in order to improve the remediation of environmental insults. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Limburgs Univ Ctr, Dept Environm Biol, B-3590 Diepenbeek, Belgium. Vlaamse Instelling Technol Onderzoek, Flemish Inst Technol Res, Environm Technol Expertise Ctr, B-2400 Mol, Belgium. RP van der Lelie, D (reprint author), Brookhaven Natl Lab, Dept Biol, Bldg 463, Upton, NY 11973 USA. EM vdlelied@bnl.gov NR 22 TC 124 Z9 135 U1 4 U2 34 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 2005 VL 71 IS 12 BP 8500 EP 8505 DI 10.1128/AEM.71.12.8500-8505.2005 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 999VB UT WOS:000234417600106 PM 16332840 ER PT J AU Pozhitkov, A Chernov, B Yershov, G Noble, PA AF Pozhitkov, A Chernov, B Yershov, G Noble, PA TI Evaluation of gel-pad oligonucleotide microarray technology by using artificial neural networks SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MASSIVE PARALLEL ANALYSIS; OLIGODEOXYRIBONUCLEOTIDE MICROCHIPS; BINDING-SPECIFICITY; THERMODYNAMIC ANALYSIS; MICROBIAL COMMUNITIES; HYBRIDIZATION PROBES; RIBOSOMAL-RNA; DNA DUPLEXES; IDENTIFICATION; BIOFILMS AB Past studies have suggested that thermal dissociation analysis of nucleic acids hybridized to DNA microarrays would improve discrimination among duplex types by scanning through a broad range of stringency conditions. To more fully constrain the utility of this approach using a previously described gel-pad microarray format, artificial neural networks (NNs) were trained to recognize noisy or low-quality data, as might derive from nonspecific fluorescence, poor hybridization, or compromised data collection. The NNs were trained to classify dissociation profiles (melts) into groups based on selected characteristics (e.g., initial signal intensity, area under the curve) using a data set of 21,044 profiles derived from 186 probes hybridized to a study set of RNA extracted from 32 microbes common to the human oral cavity. Three melt profile groups were identified: one group consisted mostly of ideal melt profiles; another group consisted mostly of poor melt profiles; and, the remainder were difficult to classify. Screening of melting profiles of perfect-match hybrids revealed inconsistencies in the form of melting profiles even for identical probes on the same microarray hybridized to same target rRNA. Approximately 18% of perfect-match duplex types were correctly classified as poor. Experimental variability and deviation from ideal melt behavior were shown to be attributable primarily to a method of local background subtraction that was very sensitive to displacement of the grid frames used for image capture (both determined by the image analysis system) and duplexes with low binding constants. Additional results showed that long RNA fragments limit the discriminating power among duplex types. C1 Univ Washington, Seattle, WA 98195 USA. Argonne Natl Lab, Biodetect Technol Sect, Argonne, IL 60439 USA. RP Noble, PA (reprint author), Univ Washington, 201 More Hall, Seattle, WA 98195 USA. EM panoble@washington.edu RI Noble, Peter/A-8117-2008 OI Noble, Peter/0000-0002-6013-2588 FU NIDCR NIH HHS [1U01DE014955-01, U01 DE014955] NR 52 TC 23 Z9 26 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 2005 VL 71 IS 12 BP 8663 EP 8676 DI 10.1128/AEM.71.12.8663-8676.2005 PG 14 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 999VB UT WOS:000234417600127 PM 16332861 ER PT J AU Stoner, DL Watson, SM Stedtfeld, RD Meakin, P Griffel, LK Tyler, TL Pegram, LM Barnes, JM Deason, VA AF Stoner, DL Watson, SM Stedtfeld, RD Meakin, P Griffel, LK Tyler, TL Pegram, LM Barnes, JM Deason, VA TI Application of stereolithographic custom models for studying the impact of biofilms and mineral precipitation on fluid flow SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID CALCIUM-CARBONATE PRECIPITATION; BIOMASS PLUG DEVELOPMENT; POROUS-MEDIA; 3-PHASE FLOW; OIL-RECOVERY; FRACTURE; ROUGHNESS; BIOHYDROMETALLURGY; MICROORGANISMS; PROPAGATION AB Here we introduce the use of transparent experimental models fabricated by stereolithography for studying the impacts of biomass accumulation, minerals precipitation, and physical configuration of flow paths on liquid flow in fracture apertures. The internal configuration of the models ranged in complexity from simple geometric shapes to those that incorporate replicated surfaces of natural fractures and computationally derived fracture surfaces. High-resolution digital time-lapse imaging was employed to qualitatively observe the migration of colloidal and soluble dyes through the flow models. In this study, a Sphingomonas sp. and Sporosarcina (Bacillus) pasteurii influenced the fluid dynamics by physically altering flow paths. Microbial colonization and calcite deposition enhanced the stagnant regions adjacent to solid boundaries. Microbial growth and calcite precipitation occurred to a greater extent in areas behind the fabricated obstacles and less in high-velocity orifices. C1 Idaho Natl Engn Lab, Dept Biol Sci, Idaho Falls, ID 83415 USA. Idaho Natl Engn Lab, Dept Phys, Idaho Falls, ID 83415 USA. Idaho Natl Engn Lab, Ctr Adv Modeling & Simulat, Idaho Falls, ID 83415 USA. RP Stoner, DL (reprint author), Univ Idaho, Dept Chem, 1776 Sci Ctr Dr,Suite 306, Idaho Falls, ID 83402 USA. EM stondl@if.uidaho.edu NR 48 TC 6 Z9 6 U1 0 U2 7 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 2005 VL 71 IS 12 BP 8721 EP 8728 DI 10.1128/AEM.71.12.8721-8728.2005 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 999VB UT WOS:000234417600133 PM 16332867 ER PT J AU Moser, DP Gihring, TM Brockman, FJ Fredrickson, JK Balkwill, DL Dollhopf, ME Lollar, BS Pratt, LM Boice, E Southam, G Wanger, G Baker, BJ Pfiffner, SM Lin, LH Onstott, TC AF Moser, DP Gihring, TM Brockman, FJ Fredrickson, JK Balkwill, DL Dollhopf, ME Lollar, BS Pratt, LM Boice, E Southam, G Wanger, G Baker, BJ Pfiffner, SM Lin, LH Onstott, TC TI Desulfotomaculum and Methanobacterium spp. dominate a 4-to 5-kilometer-deep fault SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIUM; DEEP GRANITIC AQUIFERS; RIBOSOMAL-RNA GENES; SOUTH-AFRICA; WITWATERSRAND BASIN; SUBSEAFLOOR SEDIMENTS; MICROBIAL COMMUNITIES; BASALT AQUIFERS; MINE WATERS; NOBLE-GASES AB Alkaline, sulfidic, 54 to 60 degrees C, 4 to 53 million-year-old meteoric water emanating from a borehole intersecting quartzite-hosted fractures > 3.3 km beneath the surface supported a microbial community dominated by a bacterial species affiliated with Desulfotomaculum spp. and an archaeal species related to Methanobacterium spp. The geochemical homogeneity over the 650-m length of the borehole, the lack of dividing cells, and the absence of these microorganisms in mine service water support an indigenous origin for the microbial community. The coexistence of these two microorganisms is consistent with a limiting flux of inorganic carbon and SO42- in the presence of high pH, high concentrations of H-2 and CH4, and minimal free energy for autotrophic methanogenesis. Sulfide isotopic compositions were highly enriched, consistent with microbial SO42- reduction under hydrologic isolation. An analogous microbial couple and similar abiogenic gas chemistry have been reported recently for hydrothermal carbonate vents of the Lost City near the Mid-Atlantic Ridge (D. S. Kelly et al., Science 307:1428-1434, 2005), suggesting that these features may be common to deep subsurface habitats (continental and marine) bearing this geochemical signature. The geochemical setting and microbial communities described here are notably different from microbial ecosystems reported for shallower continental subsurface environments. C1 Pacific NW Natl Lab, Envirom Microbiol Grp, Richland, WA 99352 USA. Florida State Univ, Dept Biomed Sci Biol, Tallahassee, FL 32306 USA. Univ Toronto, Dept Geosci, Toronto, ON M5S 3B1, Canada. Indiana Univ, Dept Geol Sci, Biogeochem Labs, Bloomington, IN 47405 USA. Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Tennessee, Ctr Biomarker Anal, Knoxville, TN 37932 USA. Princeton Univ, Dept Geol & Geophys Sci, Princeton, NJ 08544 USA. RP Moser, DP (reprint author), Desert Res Inst, 755 Flamingo Rd, Las Vegas, NV 89119 USA. EM duane.moser@dri.edu RI Lin, Li-Hung/K-8091-2012; Southam, Gordon/D-1983-2013; Baker, Brett/P-1783-2014; OI Southam, Gordon/0000-0002-8941-1249; Baker, Brett/0000-0002-5971-1021; Lin, Li-Hung/0000-0002-0985-1464 NR 78 TC 81 Z9 82 U1 2 U2 30 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD DEC PY 2005 VL 71 IS 12 BP 8773 EP 8783 DI 10.1128/AEM.71.12.8773-8783.2005 PG 11 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 999VB UT WOS:000234417600139 PM 16332873 ER PT J AU Liu, MB Xie, WP Liu, GR AF Liu, MB Xie, WP Liu, GR TI Modeling incompressible flows using a finite particle method SO APPLIED MATHEMATICAL MODELLING LA English DT Article DE meshless/meshfree methods; finite particle method; smoothed particle hydrodynamics; basis function; incompressible flow ID COMPUTATIONAL MECHANICS; HYDRODYNAMICS METHOD; FREE-SURFACE; SPH; FLUID; SIMULATION; EXPLOSION AB This paper describes the applications of a finite particle method (FPM) to modeling incompressible flow problems. FPM is a meshfree particle method in which the approximation of a field variable and its derivatives can be simultaneously obtained through solving a pointwise matrix equation. A set of basis functions is employed to obtain the coefficient matrix through a sequence of transformations. The finite particle method can be used to discretize the Navier-Stokes equation that governs fluid flows. The incompressible flows are modeled as slightly compressible via specially selected equations of state. Four numerical examples including the classic Poiseuille flow, Couette flow, shear driven cavity and a dam collapsing problem are presented with comparisons to other sources. The numerical examples demonstrate that FPM is a very attractive alternative for simulating incompressible flows, especially those with free surfaces, moving interfaces or deformable boundaries. (C) 2005 Elsevier Inc. All rights reserved. C1 Natl Univ Singapore, Dept Mech Engn, Singapore 119260, Singapore. Shaoyang Univ, Dept Math, Shaoyang 422000, Hunan, Peoples R China. RP Liu, MB (reprint author), Idaho Natl Engn & Environm Lab, POB 1625,MS 2025, Idaho Falls, ID 83415 USA. EM moubl@inel.gov RI Liu, GR/B-6845-2013 OI Liu, GR/0000-0001-8337-657X NR 44 TC 75 Z9 83 U1 9 U2 22 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0307-904X J9 APPL MATH MODEL JI Appl. Math. Model. PD DEC PY 2005 VL 29 IS 12 BP 1252 EP 1270 DI 10.1016/j.apm.2005.05.003 PG 19 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA 982JW UT WOS:000233155200007 ER PT J AU Nilsen, J Johnson, WR AF Nilsen, J Johnson, WR TI Plasma interferometry and how the bound-electron contribution can bend fringes in unexpected ways SO APPLIED OPTICS LA English DT Article ID RAY; DIAGNOSTICS; CONDUCTION AB Utilizing a new average atom code, we calculate the index of refraction in C, Al, Ti, and Pd plasmas and show many conditions over which the bound-electron contribution dominates the free electrons as we explore photon energies from the optical to 100 eV (12 nm) soft x rays. For decades measurement of the electron density in plasmas by interferometers has relied on the approximation that the index of refraction in a plasma is due solely to the free electrons and therefore is less than 1. Recent measurements of Al plasmas using x-ray laser interferometers observed fringes bending in the opposite direction than expected due to the bound-electron contribution causing the index of refraction to be larger than 1. During the next decade x-ray free-electron lasers and other sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths, so understanding the index of refraction in plasmas is essential. (c) 2005 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. RP Nilsen, J (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM jnilsen@llnl.gov NR 20 TC 9 Z9 9 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 2005 VL 44 IS 34 BP 7295 EP 7301 DI 10.1364/AO.44.007295 PG 7 WC Optics SC Optics GA 989LH UT WOS:000233674700006 PM 16353798 ER PT J AU Wang, W Gu, BH AF Wang, W Gu, BH TI New surface-enhanced Raman spectroscopy substrates via self-assembly of silver nanoparticles for perchlorate detection in water SO APPLIED SPECTROSCOPY LA English DT Article DE Raman spectroscopy; perchlorate detection; surface-enhanced Raman spectroscopy; SERS; silver nanoparticles; silane ID SILICA-GEL; SCATTERING; SERS; FILMS; ADSORPTION; ANIONS; IODIDE; MILK AB Perchlorate (ClO4-) has recently emerged as a widespread contaminant in drinking water and groundwater supplies in the United States, and a need exists for rapid detection and monitoring of this contaminant. In this study, surface-enhanced Raman spectroscopy (SERS) was studied as a means of ClO4- detection, and new sol-gel-based SERS substrates were developed by self-assembly of silver colloidal nanoparticles with various functionalized silane reagents. These substrate materials were tailored to allow detection of ClO4- in water with improved sorptivity, stability, and sensitivity and with the ability to detect ClO4- at concentrations as low as 10(-6) M (or 100 mu g/L) with good reproducibility. Similar techniques were used to fabricate capillary SERS flow cells by assembling functionalized silver nanoparticles capable of attracting ClO4- to the SERS surface or the internal wall of glass capillaries. These capillary How cells could be readily configured to allow for in situ, nondestructive detection of ClO4- via fiber optics. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Wang, W (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM wangw@ornl.gov RI Wang, Wei/B-5924-2012; Gu, Baohua/B-9511-2012 OI Gu, Baohua/0000-0002-7299-2956 NR 30 TC 23 Z9 24 U1 1 U2 19 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD DEC PY 2005 VL 59 IS 12 BP 1509 EP 1515 DI 10.1366/000370205775142458 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 996PW UT WOS:000234187500011 PM 16390591 ER PT J AU Chang, SL Zhou, CQ Golchert, B AF Chang, SL Zhou, CQ Golchert, B TI Eulerian approach for multiphase flow simulation in a glass melter SO APPLIED THERMAL ENGINEERING LA English DT Article DE glass melter; multiphase flow; CFD; eulerian approach AB A glass furnace, consisting of a combustion space and a glass melter, uses combustion heat to melt sand and cullet into liquid glass to make products. Glass quality is mainly dependent on the temperature, glass composition, and the level of impurities in a glass melter, which include solid batch/cullet particles, liquid glass, and gas bubbles. A comprehensive computational model using an Eulerian approach has been developed to simulate multiphase flows in a glass melter. It includes all the phases, divides solid particles or gas bubbles into various size groups, and treats each group as a continuum. The derived mass, momentum, and energy conservation equations of the flow are solved for local properties for each phase. The simulation considers the heating and melting of the batch (mainly from the radiative heat from combustion and from the convective heat from the molten glass), the formation and transport of bubbles, and the heating and mixing of the liquid glass. The approach was incorporated into a multiphase reacting flow computational fluid dynamics code that simulates overall glass furnace flows to evaluate the glass quality and furnace efficiency. (c) 2005 Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Purdue Univ Calumet, Ctr, Dept Mech Engn, Hammond, IN 46323 USA. RP Zhou, CQ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM qzhou@calumet.purdue.edu NR 13 TC 6 Z9 11 U1 2 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD DEC PY 2005 VL 25 IS 17-18 BP 3083 EP 3103 DI 10.1016/j.applthermaleng.2005.03.014 PG 21 WC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics SC Thermodynamics; Energy & Fuels; Engineering; Mechanics GA 961SU UT WOS:000231682900031 ER PT J AU Sand, JR Fischer, JC AF Sand, JR Fischer, JC TI Active desiccant integration with packaged rooftop HVAC equipment SO APPLIED THERMAL ENGINEERING LA English DT Article DE desiccants; humidity control; ventilation; packaged systems AB Current research indicates a direct correlation between indoor air quality and fresh air ventilation rates which supports requirements for building ventilation standards calling for continuous supply and increased amounts of ventilation to help assure safe and healthy interior air environments [O. Seppanen, W.J. Fisk, M.J. Mendell, Ventilation rates and health, ASHRAE Journal (August) (2002) 56-58; C.C. Downing, C.W. Bayer, Classroom indoor air quality vs. ventilation rate, ASHRAE Trans., 1993, Vol. 99, Part 2, Paper Number DE-93-19-1, pp. 1099-1103. [1,2]]. Off-the-shelf, packaged rooftop equipment used to air condition most facilities is not designed to handle the increased or continuous supply of outdoor air necessary to comply with building ventilation codes written to this new standard [American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc. (ASHRAE), Ventilation for acceptable indoor air quality, Standard 62-1989, 1791 Tullie Circle, NE, Atlanta, GA 30329. [3]]. Integration of a rooftop, unitary air conditioner with an active desiccant module (ADM) allows the use of a standard rooftop air conditioner with a thermally regenerated active desiccant component to provide a compact, cost-effective, and simple-to-use packaged system for efficiently pre-treating and supplying ventilation air adequate to ensure healthy indoor environments. By designing a combined vapor-compression/active desiccant system with the desiccant component positioned after it conventional cooling coil, the dehumidification effectiveness of the desiccant is significantly enhanced because it operates on cold, saturated, or nearly saturated, air leaving the evaporator. "Post-coil" rather than the normally used, "pre-coil" desiccant arrangement also minimizes the regeneration temperature required for the active desiccant, allows for partial bypass and post-cooling of the desiccated air after recombination, and dramatic decreases in the overall size for the pre-conditioning unit. (c) 2005 Elsevier Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Semco Inc, Marietta, GA 30067 USA. RP Sand, JR (reprint author), Oak Ridge Natl Lab, 1000 Bethel Valley Rd, Oak Ridge, TN 37830 USA. EM sandjr@ornl.gov NR 12 TC 17 Z9 18 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD DEC PY 2005 VL 25 IS 17-18 BP 3138 EP 3148 DI 10.1016/j.applthermaleng.2005.04.007 PG 11 WC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics SC Thermodynamics; Energy & Fuels; Engineering; Mechanics GA 961SU UT WOS:000231682900035 ER PT J AU Leganes, F Blanco-Rivero, A Fernandez-Pinas, F Redondo, M Fernandez-Valiente, E Fan, Q Lechno-Yossef, S Wolk, CP AF Leganes, F Blanco-Rivero, A Fernandez-Pinas, F Redondo, M Fernandez-Valiente, E Fan, Q Lechno-Yossef, S Wolk, CP TI Wide variation in the cyanobacterial complement of presumptive penicillin-binding proteins SO ARCHIVES OF MICROBIOLOGY LA English DT Article DE cyanobacteria; cell differentiation; cell shape; fox genes; penicillin-binding protein; peptidoglycan; heterocysts ID SP STRAIN PCC-7120; AEROBIC NITROGEN-FIXATION; ESCHERICHIA-COLI; SEQUENCE-ANALYSIS; BETA-LACTAMASES; BACILLUS-SUBTILIS; MORPHOLOGY; PREDICTION; ENVELOPE; CARBOXYPEPTIDASE AB A genomic analysis of putative penicillin-binding proteins (PBPs) that are involved in the synthesis of the peptidoglycan layer of the cell wall and are encoded in 12 cyanobacterial genomes was performed in order to help elucidate the role(s) of these proteins in peptidoglycan synthesis, especially during cyanobacterial cellular differentiation. The analysis suggested that the minimum set of PBPs needed to assemble the peptidoglycan layer in cyanobacteria probably does not exceed one bifunctional transpeptidase-transglycosylase Class A high-molecular-weight PBP; two Class B high-molecular-weight PBPs, one of them probably involved in cellular elongation and the other in septum formation; and one low-molecular-weight PBP. The low-molecular-weight PBPs of all of the cyanobacteria analyzed are putative endopeptidases and are encoded by fewer genes than in Escherichia coli. We show that in Anabaena sp. strain PCC 7120, predicted proteins All2981 and Alr4579, like Alr5101, are Class A high-molecular-weight PBPs that are required for the functional differentiation of aerobically diazotrophic heterocysts, indicating that some members of this class of PBPs are required specifically for cellular developmental processes. C1 Univ Autonoma Madrid, Dept Biol, Fac Ciencias, E-28049 Madrid, Spain. Michigan State Univ, Dept Plant Biol, E Lansing, MI 48824 USA. MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. RP Leganes, F (reprint author), Univ Autonoma Madrid, Dept Biol, Fac Ciencias, E-28049 Madrid, Spain. EM francisco.leganes@uam.es RI FAN, QING/G-6356-2012; Redondo-Nieto, Miguel/A-6169-2011; OI Redondo-Nieto, Miguel/0000-0002-3361-520X; Fernandez-Pinas, Francisca/0000-0002-7444-7601 NR 52 TC 24 Z9 25 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0302-8933 J9 ARCH MICROBIOL JI Arch. Microbiol. PD DEC PY 2005 VL 184 IS 4 BP 234 EP 248 DI 10.1007/s00203-005-0046-8 PG 15 WC Microbiology SC Microbiology GA 984TP UT WOS:000233327500005 PM 16231162 ER PT J AU Grosskopf, I Baroukh, N Lee, SJ Kamari, Y Harats, D Rubin, EM Pennacchio, LA Cooper, AD AF Grosskopf, I Baroukh, N Lee, SJ Kamari, Y Harats, D Rubin, EM Pennacchio, LA Cooper, AD TI Apolipoprotein A-V deficiency results in marked hypertriglyceridemia attributable to decreased lipolysis of triglyceride-rich lipoproteins and removal of their remnants SO ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY LA English DT Article DE Apoa5; hypertriglyceridemia; knockout; lipolysis; triglyceride-rich lipoproteins ID LOW-DENSITY LIPOPROTEINS; PERFUSED-RAT-LIVER; CHYLOMICRON REMNANTS; LDL RECEPTOR; PLASMA-LIPOPROTEINS; HUMAN-FIBROBLASTS; TRANSGENIC MICE; HDL METABOLISM; HEPATIC LIPASE; MOUSE-LIVER AB Objective - ApoAV, a newly discovered apoprotein, affects plasma triglyceride level. To determine how this occurs, we studied triglyceride-rich lipoprotein (TRL) metabolism in mice deficient in apoAV. Methods and Results - No significant difference in triglyceride production rate was found between apoa5(-/-) mice and controls. The presence or absence of apoAV affected TRL catabolism. After the injection of C-14-palmitate and H-3-cholesterol labeled chylomicrons and I-125-labeled chylomicron remnants, the disappearance of C-14, H-3, and I-125 was significantly slower in apoa5(-/-) mice relative to controls. This was because of diminished lipolysis of TRL and the reduced rate of uptake of their remnants in apoa5(-/-) mice. Observed elevated cholesterol level was caused by increased high-density lipoprotein (HDL) cholesterol in apoa5(-/-) mice. VLDL from apoa5(-/-) mice were poor substrate for lipoprotein lipase, and did not bind to the low-density lipoprotein (LDL) receptor as well as normal very-low-density lipoprotein ( VLDL). LDL receptor levels were slightly elevated in apoa5(-/-) mice consistent with lower remnant uptake rates. These alterations may be the result of the lower apoE-to-apoC ratio found in VLDL isolated from apoa5(-/-) mice. Conclusions - These results support the hypothesis that the absence of apoAV slows lipolysis of TRL and the removal of their remnants by regulating their apoproteins content after secretion. C1 Tel Aviv Sourasky Med Ctr, Dept Med, IL-64239 Tel Aviv, Israel. Tel Aviv Univ, Sackler Fac Med, IL-69978 Tel Aviv, Israel. Stanford Univ, Dept Med, Sch Med, Stanford, CA 94305 USA. Palo Alto Med Fdn, Res Inst, Palo Alto, CA 94301 USA. Lawrence Berkeley Natl Lab, Dept Genome Sci, Berkeley, CA USA. DOE Joint Genome Inst, Walnut Creek, CA USA. Korea Univ, Div Food Sci, Seoul 136701, South Korea. Chaim Sheba Med Ctr, Inst Lipid & Atherosclerosis Res, IL-52621 Tel Hashomer, Israel. RP Grosskopf, I (reprint author), Tel Aviv Sourasky Med Ctr, Dept Med, 6 Weizman St, IL-64239 Tel Aviv, Israel. EM itamarg@stanford.edu RI Lee, Sung-Joon/F-2435-2013 FU NHLBI NIH HHS [HL071954A, HL66681]; NIDDK NIH HHS [DK056339, DK38318] NR 40 TC 85 Z9 100 U1 1 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3261 USA SN 1079-5642 J9 ARTERIOSCL THROM VAS JI Arterioscler. Thromb. Vasc. Biol. PD DEC PY 2005 VL 25 IS 12 BP 2573 EP 2579 DI 10.1161/01.ATV.0000186189.26141.12 PG 7 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA 986PF UT WOS:000233461500024 PM 16166565 ER PT J AU Liebel, B Brodrick, J AF Liebel, B Brodrick, J TI Choosing the right light SO ASHRAE JOURNAL LA English DT Editorial Material C1 AfterImage Space, Emeryville, CA USA. US DOE, Bldg Technol Program, Washington, DC USA. RP Liebel, B (reprint author), AfterImage Space, Emeryville, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD DEC PY 2005 VL 47 IS 12 BP 122 EP 124 PG 3 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 994DT UT WOS:000234011400021 ER PT J AU Hook, IM Howell, DA Aldering, G Amanullah, R Burns, MS Conley, A Deustua, SE Ellis, R Fabbro, S Fadeyev, V Folatelli, G Garavini, G Gibbons, R Goldhaber, G Goobar, A Groom, DE Kim, AG Knop, RA Kowalski, M Lidman, C Nobili, S Nugent, PE Pain, R Pennypacker, CR Perlmutter, S Ruiz-Lapuente, P Sainton, G Schaefer, BE Smith, E Spadafora, AL Stanishev, V Thomas, RC Walton, NA Wang, L Wood-Vasey, WM AF Hook, IM Howell, DA Aldering, G Amanullah, R Burns, MS Conley, A Deustua, SE Ellis, R Fabbro, S Fadeyev, V Folatelli, G Garavini, G Gibbons, R Goldhaber, G Goobar, A Groom, DE Kim, AG Knop, RA Kowalski, M Lidman, C Nobili, S Nugent, PE Pain, R Pennypacker, CR Perlmutter, S Ruiz-Lapuente, P Sainton, G Schaefer, BE Smith, E Spadafora, AL Stanishev, V Thomas, RC Walton, NA Wang, L Wood-Vasey, WM CA Supernova Cosmology Project TI Spectra of high-redshift type IA supernovae and a comparison with their low-redshift counterparts SO ASTRONOMICAL JOURNAL LA English DT Article DE distance scale; stars : distances; supernovae : general ID SOUTHERN SPECTROPHOTOMETRIC STANDARDS; HUBBLE-SPACE-TELESCOPE; SN 1999BY; ULTRAVIOLET EXTINCTION; OPTICAL-SPECTRA; UNIVERSE; SPECTROSCOPY; DECELERATION; CONSTRAINTS; 1991BG AB We present spectra for 14 high-redshift (0.17 < z < 0.83) supernovae, which were discovered by the Supernova Cosmology Project as part of a campaign to measure cosmological parameters. The spectra are used to determine the redshift and classify the supernova type, essential information if the supernovae are to be used for cosmological studies. Redshifts were derived either from the spectrum of the host galaxy or from the spectrum of the supernova itself. We present evidence that these supernovae are of Type Ia (SNe Ia) by matching to spectra of nearby supernovae. We find that the dates of the spectra relative to maximum light determined from this fitting process are consistent with the dates determined from the photometric light curves, and, moreover, the spectral time sequences for SNe Ia at low and high redshift are indistinguishable. We also show that the expansion velocities measured from blueshifted Ca H and K are consistent with those measured for low-redshift SNe Ia. From these first-level quantitative comparisons we find no evidence for evolution in SN Ia properties between these low- and high-redshift samples. Thus, even though our samples may not be complete, we conclude that there is a population of SNe Ia at high redshift whose spectral properties match those at low redshift. C1 Univ Oxford, Dept Phys, Nucl & Astrophys Lab, Oxford OX1 3RH, England. Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H8, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Stockholm Univ, AlbaNova Univ Ctr, Dept Phys, SE-10691 Stockholm, Sweden. Colorado Coll, Colorado Springs, CO 80903 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Amer Astron Soc, Washington, DC 20009 USA. CALTECH, Pasadena, CA 91125 USA. IST, Ctr Multidisplinar Astrofis, Lisbon, Portugal. IST, Dept Fis, Lisbon, Portugal. Univ Paris 06, Lab Phys Nucl & Hautes Energies, CNRS, IN2P3, Paris, France. Univ Paris 07, Lab Phys Nucl & Hautes Energies, CNRS, IN2P3, Paris, France. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37240 USA. European So Observ, Santiago 19, Chile. Univ Barcelona, Dept Astron, Barcelona, Spain. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. RP Hook, IM (reprint author), Univ Oxford, Dept Phys, Nucl & Astrophys Lab, Keble Rd, Oxford OX1 3RH, England. RI Folatelli, Gaston/A-4484-2011; Kowalski, Marek/G-5546-2012; Stanishev, Vallery/M-8930-2013; Perlmutter, Saul/I-3505-2015 OI Stanishev, Vallery/0000-0002-7626-1181; Perlmutter, Saul/0000-0002-4436-4661 NR 51 TC 41 Z9 43 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2005 VL 130 IS 6 BP 2788 EP 2803 DI 10.1086/497635 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 988FH UT WOS:000233576800027 ER PT J AU Domingo-Santamaria, E Torres, DF AF Domingo-Santamaria, E Torres, DF TI High energy gamma-ray emission from the starburst nucleus of NGC 253 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : cosmic rays; galaxies : starburst; galaxies : individual : NGC 253 ID GALAXY NGC 253; MOLECULAR INTERSTELLAR-MEDIUM; LUMINOUS INFRARED GALAXIES; SUPERNOVA-REMNANTS; CHANDRA OBSERVATIONS; COSMIC-RAYS; MAGNETIC-FIELDS; NEARBY GALAXIES; GAS; CO AB Both the high density medium that characterizes the central regions of starburst galaxies and its power to accelerate particles up to relativistic energies make these objects good candidates for gamma-ray sources. In this paper we present a self-consistent model of the multifrequency emission of the starburst galaxy NGC 253 from radio to gamma-rays. The model agrees with all current measurements and provides predictions for the high energy behavior of the NGC 253 central region. In particular, we discuss prospects for observations with the HESS array (and comparison with their recently obtained data) and GLAST satellite. C1 Inst Fis Altes Energies, Bellaterra 08193, Spain. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Inst Fis Altes Energies, Edifici Cn,Campus UAB, Bellaterra 08193, Spain. RI Torres, Diego/O-9422-2016 OI Torres, Diego/0000-0002-1522-9065 NR 99 TC 62 Z9 63 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2005 VL 444 IS 2 BP 403 EP U73 DI 10.1051/0004-6361:20053613 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 986PJ UT WOS:000233461900015 ER PT J AU Pourbaix, D Knapp, GR Szkody, P Ivezic, Z Kleinman, SJ Long, D Snedden, SA Nitta, A Harvanek, M Krzesinski, J Brewington, HJ Barentine, JC Neilsen, EH Brinkmann, J AF Pourbaix, D Knapp, GR Szkody, P Ivezic, Z Kleinman, SJ Long, D Snedden, SA Nitta, A Harvanek, M Krzesinski, J Brewington, HJ Barentine, JC Neilsen, EH Brinkmann, J TI Candidate spectroscopic binaries in the sloan digital sky survey SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE instrumentation : spectrographs; stars : binaries : spectroscopic ID CATACLYSMIC VARIABLES; STARS; SDSS; 1ST; RELEASE; DWARFS; SYSTEM AB We have examined the radial velocity data for stars spectroscopically observed by the Sloan Digital Sky Survey ( SDSS) more than once to investigate the incidence of spectroscopic binaries, and to evaluate the accuracy of the SDSS stellar radial velocities. We find agreement between the fraction of stars with significant velocity variations and the expected fraction of binary stars in the halo and thick disk populations. The observations produce a list of 675 possible new spectroscopic binary stars and orbits for eight of them. C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Univ Libre Bruxelles, Inst Astron & Astrophys, B-1050 Brussels, Belgium. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Apache Pt Observ, Sunspot, NM 88349 USA. Cracow Pedagog Univ, Mt Suhora Observ, PL-30084 Krakow, Poland. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Pourbaix, D (reprint author), Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. EM pourbaix@astro.princeton.edu; gk@astro.princeton.edu; szkody@astro.washington.edu; ivezic@astro.washington.edu; sjnk@apo.nmsu.edu; long@apo.nmsu.edu; snedden@apo.nmsu.edu; ank@apo.nmsu.edu; harvanek@apo.nmsu.edu; jurek@apo.nmsu.edu; hbrewington@apo.nmsu.edu; jcb@apo.nmsu.edu; neilsen@fnal.gov; jb@apo.nmsu.edu NR 34 TC 10 Z9 10 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2005 VL 444 IS 2 BP 643 EP 649 DI 10.1051/0004-6361:20053098 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 986PJ UT WOS:000233461900039 ER PT J AU Linder, EV AF Linder, EV TI Curved space or curved vacuum? SO ASTROPARTICLE PHYSICS LA English DT Article ID PROBING DARK ENERGY; OSCILLATIONS; SUPERNOVAE; UNIVERSE AB While the simple Picture of a spatially flat, matter plus cosmological constant universe fits current observation of the accelerated expansion, strong consideration has also been given to models with dynamical Vacuum energy. We examine the tradeoff of "curving" the vacuum but retaining spatial flatness, vs. curving space but retaining the cosmological constant. These different breakdowns in the simple picture could readily be distinguished by combined high accuracy supernovae and cosmic microwave background distance Measurements. If we allow the uneasy situation of both breakdowns, the curvature can still be measured to No, but at the price of degrading estimation of the equation of state time variation by 60% or more, unless additional information (Such as weak lensing data or a tight matter density prior) is included. (c) 2005 Elsevier B.V. All rights reserved. C1 Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. RP Linder, EV (reprint author), Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. EM evlinder@lbl.gov NR 25 TC 40 Z9 40 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD DEC PY 2005 VL 24 IS 4-5 BP 391 EP 399 DI 10.1016/j.astropartphys.2005.08.004 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 989TP UT WOS:000233697100009 ER PT J AU Schulz, AE Hennawi, J White, M AF Schulz, AE Hennawi, J White, M TI Characterizing the shapes of galaxy clusters using moments of the gravitational lensing shear SO ASTROPARTICLE PHYSICS LA English DT Article DE gravitational lensing; galaxy clusters ID DARK-MATTER HALOS; ARCS AB We explore the use of the tangential component of weak lensing shear to characterize the ellipticity of clusters of galaxies. We introduce an ellipticity estimator, and quantify its properties for isolated clusters from ACDM N-body simulations. We compare the N-body results to results from smooth analytic models. The expected distribution of the estimator for mock observations is presented, and we show how this distribution is impacted by contaminants such as noise, line of sight projections, and misalignment of the central galaxy used to determine the orientation of the tri-axial halo. We examine the radial profile of the estimator and discuss tradeoffs in the observational strategy to determine Cluster shape. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Schulz, AE (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM schulz@physics.harvard.edu RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 NR 18 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD DEC PY 2005 VL 24 IS 4-5 BP 409 EP 419 DI 10.1016/j.astropartphys.2005.09.003 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 989TP UT WOS:000233697100011 ER PT J AU Cooper, MC Newman, JA Madgwick, DS Gerke, BF Yan, RB Davis, M AF Cooper, MC Newman, JA Madgwick, DS Gerke, BF Yan, RB Davis, M TI Measuring galaxy environments with deep redshift surveys SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : high-redshift; galaxies : statistics; large-scale structure of universe; methods : data analysis; methods : statistical; surveys ID DIGITAL SKY SURVEY; LOW-DENSITY ENVIRONMENTS; DARK-MATTER HALOES; STAR-FORMATION; LUMINOSITY FUNCTION; FIELD GALAXIES; EVOLUTION; DEPENDENCE; COMBO-17; CLUSTERS AB We study the applicability of several galaxy environment measures (nth-nearest neighbor distance, counts in an aperture, and Voronoi volume) within deep redshift surveys. Mock galaxy catalogs are employed to mimic representative photometric and spectroscopic surveys at high redshift (z similar to 1). We investigate the effects of survey edges, redshift precision, redshift-space distortions, and target selection on each environment measure. We find that even optimistic photometric redshift errors (sigma(z) = 0.02) smear out the line-of-sight galaxy distribution irretrievably on small scales; this significantly limits the application of photometric redshift surveys to environment studies. Edges and holes in a survey field dramatically affect the estimation of environment, with the impact of edge effects depending on the adopted environment measure. These edge effects considerably limit the usefulness of smaller survey fields ( e. g., the GOODS fields) for studies of galaxy environment. In even the poorest groups and clusters, redshift-space distortions limit the effectiveness of each environment statistic; measuring density in projection ( e. g., using counts in a cylindrical aperture or a projected nth-nearest neighbor distance measure) significantly improves the accuracy of measures in such overdense environments. For the DEEP2 Galaxy Redshift Survey, we conclude that among the environment estimators tested the projected nth-nearest neighbor distance measure provides the most accurate estimate of local galaxy density over a continuous and broad range of scales. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Cooper, MC (reprint author), Univ Calif Berkeley, Dept Astron, Mail Code 3411, Berkeley, CA 94720 USA. EM cooper@astro.berkeley.edu; janewman@lbl.gov; dsmadgwick@lbl.gov; bgerke@astro.berkeley.edu; renbin@astro.berkeley.edu; marc@astro.berkeley.edu OI Yan, Renbin/0000-0003-1025-1711 NR 53 TC 97 Z9 97 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2005 VL 634 IS 2 BP 833 EP 848 DI 10.1086/432868 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 988FO UT WOS:000233577700010 ER PT J AU Rest, A Stubbs, C Becker, AC Miknaitis, GA Micell, A Covarrubias, R Hawley, SL Smith, RC Suntzeff, NB Olsen, K Prieto, JL Hiriart, R Welch, DL Cook, KH Nikolaev, S Huber, M Prochtor, G Clocchiatti, A Minniti, D Garg, A Challis, P Keller, SC Schmidt, BP AF Rest, A Stubbs, C Becker, AC Miknaitis, GA Micell, A Covarrubias, R Hawley, SL Smith, RC Suntzeff, NB Olsen, K Prieto, JL Hiriart, R Welch, DL Cook, KH Nikolaev, S Huber, M Prochtor, G Clocchiatti, A Minniti, D Garg, A Challis, P Keller, SC Schmidt, BP TI Testing LMC microlensing scenarios: The discrimination power of the SuperMACHO microlensing survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies : halos; galaxies : structure; Galaxy : structure; gravitational lensing; Magellanic Clouds ID LARGE-MAGELLANIC-CLOUD; SURVEY COMMISSIONING DATA; NEAR-INFRARED SURVEYS; HALO WHITE-DWARFS; HUBBLE-DEEP-FIELD; LOW-MASS STARS; MACHO PROJECT; DARK-MATTER; GALACTIC HALO; MILKY-WAY AB Characterizing the nature and spatial distribution of the lensing objects that produce the previously measured microlensing optical depth toward the Large Magellanic Cloud (LMC) remains an open problem. We present an appraisal of the ability of the SuperMACHO Project, a next-generation microlensing survey directed toward the LMC, to discriminate between various proposed lensing populations. We consider two scenarios: lensing by a uniform foreground screen of objects and self-lensing by LMC stars. The optical depth for "screen lensing'' is essentially constant across the face of the LMC, whereas the optical depth for self-lensing shows a strong spatial dependence. We have carried out extensive simulations, based on data obtained during the first year of the project, to assess the SuperMACHO survey's ability to discriminate between these two scenarios. In our simulations we predict the expected number of observed microlensing events for various LMC models for each of our fields by adding artificial stars to the images and estimating the spatial and temporal efficiency of detecting microlensing events using Monte Carlo methods. We find that the event rate itself shows significant sensitivity to the choice of the LMC luminosity function, limiting the conclusions that can be drawn from the absolute rate. If instead we determine the differential event rate across the LMC, we will decrease the impact of these systematic biases and render our conclusions more robust. With this approach the SuperMACHO Project should be able to distinguish between the two categories of lens populations. This will provide important constraints on the nature of the lensing objects and their contributions to the Galactic dark matter halo. C1 Cerro Tololo Interamer Observ, La Serena, Chile. Univ Washington, Dept Astron, Seattle, WA 98195 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. RP Cerro Tololo Interamer Observ, Casilla 603, La Serena, Chile. RI Stubbs, Christopher/C-2829-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Schmidt, Brian/0000-0002-8538-9195 NR 74 TC 74 Z9 74 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2005 VL 634 IS 2 BP 1103 EP 1115 DI 10.1086/497060 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 988FO UT WOS:000233577700031 ER PT J AU Howell, DA Sullivan, M Perrett, K Bronder, TJ Hook, IM Astier, P Aubourg, E Balam, D Basa, S Carlberg, RG Fabbro, S Fouchez, D Guy, J Lafoux, H Neill, JD Pain, R Palanque-Delabrouille, N Pritchet, CJ Regnault, N Rich, J Taillet, R Knop, R McMahon, RG Perlmutter, S Walton, NA AF Howell, DA Sullivan, M Perrett, K Bronder, TJ Hook, IM Astier, P Aubourg, E Balam, D Basa, S Carlberg, RG Fabbro, S Fouchez, D Guy, J Lafoux, H Neill, JD Pain, R Palanque-Delabrouille, N Pritchet, CJ Regnault, N Rich, J Taillet, R Knop, R McMahon, RG Perlmutter, S Walton, NA TI Gemini spectroscopy of supernovae from the supernova legacy survey: Improving high-redshift supernova selection and classification SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; methods : data analysis; supernovae : general; techniques : spectroscopic; surveys ID IA SUPERNOVAE; OPTICAL-SPECTRA; ULTRAVIOLET; EXTINCTION; GALAXIES AB We present new techniques for improving the efficiency of supernova (SN) classification at high redshift using 64 candidates observed at Gemini North and South during the first year of the Supernova Legacy Survey ( SNLS). The SNLS is an ongoing 5 year project with the goal of measuring the equation of state of dark energy by discovering and following over 700 high-redshift SNe Ia using data from the Canada-France-Hawaii Telescope Legacy Survey. We achieve an improvement in the SN Ia spectroscopic confirmation rate: at Gemini 71% of candidates are now confirmed as SNe Ia, compared to 54% using the methods of previous surveys. This is despite the comparatively high redshift of this sample, in which the median SN Ia redshift is z = 0.81 (0.155 <= z <= 1.01). These improvements were realized because we use the unprecedented color coverage and light curve sampling of the SNLS to predict whether a candidate is a SN Ia and to estimate its redshift, before obtaining a spectrum, using a new technique called the "SN photo-z." In addition, we have improved techniques for galaxy subtraction and SN template chi(2) fitting, allowing us to identify candidates even when they are only 15% as bright as the host galaxy. The largest impediment to SN identification is found to be host galaxy contamination of the spectrum-when the SN was at least as bright as the underlying host galaxy the target was identified more than 90% of the time. However, even SNe in bright host galaxies can be easily identified in good seeing conditions. When the image quality was better than 0 ''.55, the candidate was identified 88% of the time. Over the 5 year course of the survey, using the selection techniques presented here, we will be able to add similar to 170 more confirmed SNe Ia than would be possible using previous methods. C1 Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H8, Canada. Univ Oxford, Oxford OX1 3RH, England. CNRS, IN2P3, LPNHE, F-75005 Paris, France. Univ Paris 06, F-75005 Paris, France. Univ Paris 07, F-75005 Paris, France. APC, F-75231 Paris, France. CEA Saclay, DSM, DAPNIA, F-91191 Gif Sur Yvette, France. Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada. LAM, F-13376 Marseille, France. Inst Super Tecn, CENTRA, Ctr Multidisciplinar Astrofis, P-1049 Lisbon, Portugal. CNRS Marseille Luminy, CPPM, F-13288 Marseille, France. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Univ Cambridge, Astron Inst, Cambridge CB3 0HA, England. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Toronto, Dept Astron & Astrophys, 60 St George St, Toronto, ON M5S 3H8, Canada. RI Carlberg, Raymond/I-6947-2012; Perlmutter, Saul/I-3505-2015 OI Carlberg, Raymond/0000-0002-7667-0081; Perlmutter, Saul/0000-0002-4436-4661 NR 23 TC 106 Z9 107 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 DEC 1 PY 2005 VL 634 IS 2 BP 1190 EP 1201 DI 10.1086/497119 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 988FO UT WOS:000233577700039 ER PT J AU Stanford, SA Eisenhardt, PR Brodwin, M Gonzalez, AH Stern, D Jannuzi, BT Dey, A Brown, MJI McKenzie, E Elston, R AF Stanford, SA Eisenhardt, PR Brodwin, M Gonzalez, AH Stern, D Jannuzi, BT Dey, A Brown, MJI McKenzie, E Elston, R TI An IR-selected galaxy cluster at z=1.41 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; galaxies : evolution; galaxies : formation ID COLOR-MAGNITUDE RELATION; SPITZER-SPACE-TELESCOPE; ARRAY CAMERA IRAC; DISTANT CLUSTERS; EVOLUTION; RDCS-1252.9-2927; Z-SIMILAR-TO-1; PHOTOMETRY; MORPHOLOGY AB We report the discovery of a galaxy cluster at z = 1.41. ISCS J143809 + 341419 was found in the Spitzer/IRAC Shallow Survey of the Bootes field in the NOAO Deep Wide- Field Survey carried out using IRAC. The cluster candidate was initially identified as a high-density region of objects with photometric redshifts in the range 1.31 < z < 1.5. Optical spectroscopy of a limited number of objects in the region shows that five galaxies within an similar to 120" diameter region lie at z = 1.41 +/- 0.01. Most of these member galaxies have broadband colors consistent with the expected spectral energy distribution of a passively evolving elliptical galaxy formed at high redshift. The redshift of ISCS J143809 + 341419 is the highest currently known for a spectroscopically confirmed cluster of galaxies. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. RP Stanford, SA (reprint author), Univ Calif Davis, Dept Phys, 1 Shields Ave, Davis, CA 95616 USA. EM adam@igpp.ucllnl.org; prme@kromos.jpl.nasa.gov; mark.brodwin@jpl.nasa.gov; anthony@astro.ufl.edu; stern@thisvi.jpl.nasa.gov; jannuzi@noao.edu; dey@noao.edu; mbrown@astro.princeton.edu; eric@astro.ufl.edu RI Brown, Michael/B-1181-2015 OI Brown, Michael/0000-0002-1207-9137 NR 33 TC 104 Z9 104 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2005 VL 634 IS 2 BP L129 EP L132 DI 10.1086/499045 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 988FQ UT WOS:000233578000002 ER PT J AU Parolini, C Chiesa, G Gong, E Caligari, S Cortese, MM Koga, T Forte, TM Rubin, EM AF Parolini, C Chiesa, G Gong, E Caligari, S Cortese, MM Koga, T Forte, TM Rubin, EM TI Apolipoprotein A-I and the molecular variant apoA-I-Milano: Evaluation of the antiatherogenic effects in knock-in mouse model SO ATHEROSCLEROSIS LA English DT Article DE apolipoprotein A-I; HDL cholesterol; gene knock-in; mouse model; atherosclerosis ID HIGH-DENSITY-LIPOPROTEIN; TRANSGENIC MICE; IMILANO APOPROTEIN; GENE-EXPRESSION; ATHEROSCLEROSIS; CHOLESTEROL; HDL; ATHEROGENESIS; CARRIERS; DISTINCT AB No evidence of premature vascular disease is found in apolipoprotein A-I-Milano (apoA-I-M) human carriers, despite very low high density lipoprotein (HDL) cholesterol levels. Whether apoA-I-M may impart a "gain of function" in atherosclerosis protection compared to wild-type apoA-I is hotly debated. To address this question, knock-in mice expressing human apoA-I or apoA-I-M were crossed with atherosclerosis-susceptible mice expressing the human apoB/A-II transgene (h-B/A-II/A-I-Hu/Hu and h-B/A-II/A-I-M(Hu/Hu)). On a chow diet, h-B/A-II/A-I-M(Hu/Hu) mice were characterized by low HDL cholesterol levels compared to h-B/A-II/A-I-Hu/Hu mice (35.65 +/- 8.00 mg/dl versus 58.09 +/- 13.50 mg/dl, respectively; p < 0.005). Gender differences in response to high fat diet were observed in both h-B/A-II/A-I-M(Hu/Hu) and h-B/A-II/A-I-Hu/Hu lines. h-B/A-II/A-I-M(Hu/Hu) females had higher total cholesterol levels compared to h-B/A-II/A-I-Hu/Hu females (895.08 +/- 183.07 mg/dl versus 544.43 +/- 116.42 mg/dl; p < 0.05) and developed larger atherosclerotic lesions (148,260 78,924 mu m(2) versus 54,132 43,204 mu m 2, respectively; p < 0.05). On the contrary, no difference in mean lesion area was found between h-B/A-II/A-I-M(Hu/Hu) and h-B/A-II/A-I-Hu/Hu males (19,779 +/- 6098 mu m(2) versus 15,706 +/- 13,095 mu m(2). p = 0.685). Our data suggest that, in the atherosclerosis-susceptible human apoB/A-II mouse model, expression of the human apoA-I-M gene does not have protective advantage over that of the apoA-I gene. (c) 2005 Elsevier Ireland Ltd. All rights reserved. C1 Univ Milan, Dept Pharmacol Sci, I-20133 Milan, Italy. Lawrence Berkeley Natl Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Parolini, C (reprint author), Univ Milan, Dept Pharmacol Sci, I-20133 Milan, Italy. EM cinzia.parolini@unimi.it RI Parolini, Cinzia/G-8984-2012; Chiesa, Giulia/G-8987-2012 OI Parolini, Cinzia/0000-0002-5699-0918; Chiesa, Giulia/0000-0001-5553-1210 FU NHLBI NIH HHS [HL55493] NR 28 TC 33 Z9 33 U1 1 U2 3 PU ELSEVIER IRELAND LTD PI CLARE PA ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND SN 0021-9150 J9 ATHEROSCLEROSIS JI Atherosclerosis PD DEC PY 2005 VL 183 IS 2 BP 222 EP 229 DI 10.1016/j.atherosclerosis.2005.03.008 PG 8 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 989SV UT WOS:000233695000004 PM 16285990 ER PT J AU Engle, MA Gustin, MS Lindberg, SE Gertler, AW Ariya, PA AF Engle, MA Gustin, MS Lindberg, SE Gertler, AW Ariya, PA TI The influence of ozone on atmospheric emissions of gaseous elemental mercury and reactive gaseous mercury from substrates SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Mercury as a Global Pollutant CY JUN 28-JUL 02, 2004 CL Ljubljana, SLOVENIA SP Jozef Stefan Inst, Minist Educ Sci & Sport, Minist Hlth, Minist Environm & Phys Planning, Thermo Powerplant Sostanj, Salonit Anhovo, Slovenian Tourist Board, Ljubljana Turist Boart, Mercury Mind Idrija, Crankarjev Dom, US EPA, Elect Power Res Inst, Tetra Tech Inc, Tekran Inc, Oak Ridge Natl Lab, GKSS Germany, UNEP, Exponent, GEF, UNDP, UNIDO, EUROCHLOR, NIMD, CEBAM Analyt Inc, Lumex, Int Res Dev Ctr Canada DE mercury; air-surface exchange; natural mercury sources; tropospheric ozone; mercury soil emissions ID TROPOSPHERIC OZONE; BACKGROUND SOILS; MINERAL DUST; AMBIENT AIR; KINETICS; SPECIATION; REDUCTION; OXIDATION; MODEL AB Experiments were performed to investigate the effect of ozone (03) on mercury (Hg) emission from a variety of Hg-bearing substrates. Substrates with Hg(II) as the dominant Hg phase exhibited a 1.7 to 51-fold increase in elemental Hg (Hg-o) flux and a 1.3 to 8.6-fold increase in reactive gaseous mercury (RGM) flux in the presence of O-3-enriched clean (50 ppb O-3; 8 substrates) and ambient air (up to similar to 70 ppb 03; 6 substrates), relative to clean air (oxidant and Hg free air). In contrast, Hg-o fluxes from two artificially Hg-o-amended substrates decreased by more than 75% during exposure to O-3-enriched clean air relative to clean air. Reactive gaseous mercury emissions from Hgo-amended substrates increased immediately after exposure to O-3 but then decreased rapidly. These experimental results demonstrate that O-3 is very important in controlling Hg emissions from substrates. The chemical mechanisms that produced these trends are not known but potentially involve heterogenous reactions between O-3, the substrate, and Hg. Our experiments suggest they are not homogenous gas-phase reactions. Comparison of the influence of O-3 versus light on increasing Hgo emissions from dry Hg(II)-bearing substrates demonstrated that they have a similar amount of influence although O-3 appeared to be slightly more dominant. Experiments using water-saturated substrates showed that the presence of high-substrate moisture content minimizes reactions between atmospheric O-3 and substrate-bound Hg. Using conservative calculations developed in this paper, we conclude that because O-3 concentrations have roughly doubled in the last 100 years, this could have increased Hgo emissions from terrestrial substrates by 65-72%. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Nevada, Dept Nat Resource & Environm Sci, Reno, NV 89557 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Desert Res Inst, Div Atmospher Sci, Reno, NV 89512 USA. McGill Univ, Dept Chem, Montreal, PQ H3A 2K6, Canada. RP Gustin, MS (reprint author), Univ Nevada, Dept Nat Resource & Environm Sci, Mail Stop 370, Reno, NV 89557 USA. EM msg@unr.nevada.edu RI Ariya, Parisa/G-2810-2015; OI Engle, Mark/0000-0001-5258-7374 NR 34 TC 56 Z9 58 U1 1 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 2005 VL 39 IS 39 BP 7506 EP 7517 DI 10.1016/j.atmosenv.2005.07.069 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 995CG UT WOS:000234076900007 ER PT J AU Lin, CJ Lindberg, SE Ho, TC Jang, C AF Lin, CJ Lindberg, SE Ho, TC Jang, C TI Development of a processor in BEIS3 for estimating vegetative mercury emission in the continental United States SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Mercury as a Global Pollutant CY JUN 28-JUL 02, 2004 CL Ljubljana, SLOVENIA SP Jozef Stefan Inst, Minist Educ Sci & Sport, Minist Hlth, Minist Environm & Phys Planning, Thermo Powerplant Sostanj, Salonit Anhovo, Slovenian Tourist Board, Ljubljana Turist Boart, Mercury Mind Idrija, Crankarjev Dom, US EPA, Elect Power Res Inst, Tetra Tech Inc, Tekran Inc, Oak Ridge Natl Lab, GKSS Germany, UNEP, Exponent, GEF, UNDP, UNIDO, EUROCHLOR, NIMD, CEBAM Analyt Inc, Lumex, Int Res Dev Ctr Canada DE mercury emission; natural source; anthropogenic source; emission inventory estimates; BEIS3 ID GASEOUS ELEMENTAL MERCURY; ATMOSPHERIC MERCURY; EXCHANGE; MODEL; DEPOSITION; FOREST; VAPOR; FLUX; FORMULATION; SIMULATION AB We have developed a regression-based processor for estimating vegetative mercury emission within the framework of Biogenic Emission Inventory System Version 3.11 (BEIS3 V3.11). In this development, we incorporated the 230 categories of USGS landcover data to generate the vegetation-specific mercury emission in a 36-km Lambert Conformal model grid covering the continental United States (CONUS). The surface temperature and cloud-corrected solar radiation from a Mesoscale Meteorological model (MM5) were retrieved and used for calculating the diurnal variation. The implemented emission factors were either evaluated from the measured mercury flux data for selected tree species, wetland and water, or assumed for the tree species without available flux data. Annual simulations using the 2001 USEPA MM5 data were performed to investigate the seasonal emission variation. From our sensitivity analysis using three sets of emission factors, we estimated that the vegetative mercury emission in the CONUS domain ranges from a lower limit of 31 ton yr(-1) to an upper limit of 140 ton yr-1, with the best estimate at 44 ton yr-1. The modeled vegetative emission was mainly contributed from southeast US. Using the best estimate data, it is shown that mercury emission from vegetation is comparable to that from anthropogenic sources in summer (nearly half of the total emission). However, the vegetative emission decreases greatly in winter, leaving anthropogenic sources as the major emission source (> 90% in winter months). Modeling assessment indicates that including vegetative emission (44 toll yr-1) can force an increase of ambient mercury concentration of up to 0.2 ng m(-3) in summer midday, but has little impact on dry deposition of mercury. Additional emission factors can be implemented in the model once further mercury flux data become available. (c) 2005 Elsevier Ltd. All rights reserved. C1 Lamar Univ, Dept Civil Engn, Beaumont, TX 77710 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Lamar Univ, Dept Chem Engn, Beaumont, TX 77710 USA. US EPA, Off Air Qual Planning & Stand, Res Triangle Pk, NC 27711 USA. RP Lin, CJ (reprint author), Lamar Univ, Dept Civil Engn, Beaumont, TX 77710 USA. EM Jerry.Lin@Lamar.edu RI Lin, Che-Jen/K-1808-2013 OI Lin, Che-Jen/0000-0001-5990-3093 NR 28 TC 24 Z9 26 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 2005 VL 39 IS 39 BP 7529 EP 7540 DI 10.1016/j.atmosenv.2005.04.044 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 995CG UT WOS:000234076900009 ER PT J AU Streets, DG Hao, JM Wu, Y Jiang, JK Chan, M Tian, HZ Feng, XB AF Streets, DG Hao, JM Wu, Y Jiang, JK Chan, M Tian, HZ Feng, XB TI Anthropogenic mercury emissions in China SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE speciated mercury; emission inventory; coal combustion; metals smelting; China ID TOTAL GASEOUS MERCURY; ATMOSPHERIC MERCURY; COAL COMBUSTION; ASIA; INVENTORY; BIOMASS; GUIZHOU; DEPOSITION; POLLUTION; GUIYANG AB An inventory of mercury emissions from anthropogenic activities in China is compiled for the year 1999 from official statistical data. We estimate that China's emissions were 536 (+/- 236) t of total mercury. This value includes open biomass burning, but does not include natural sources or re-emission of previously deposited mercury. Approximately 45% of the Hg comes from non-ferrous metals smelting, 38% from coal combustion, and 17% from miscellaneous activities, of which battery and fluorescent lamp production and cement production are the largest. Emissions are heaviest in Liaoning and Guangdong Provinces, where extensive smelting occurs, and in Guizhou Province, where there is much small-scale combustion of high-Hg coal without emission control devices. Emissions are gridded at 30 x 30 min spatial resolution. We estimate that 56% of the Hg in China is released as Hg-0, 32% as Hg2+, and 12% as Hg-P. Particulate mercury emissions are high in China due to heavy burning of coal in residential and small industrial settings without PM controls. Emissions of Hg2+ from coal-fired power plants are high due to the absence of flue-gas desulfurization units, which tend to dissolve the soluble divalent mercury. Metals smelting operations favor the production of elemental mercury. Much of the Hg is released from small-scale activities in rather remote areas, and therefore the activity levels are quite uncertain. Also, emissions test data for Chinese sources are lacking, causing uncertainties in Hg emission factors and removal efficiencies. Overall, we calculate an uncertainty level of +/- 44% (95% confidence interval) in the estimate of total emissions. We recommend field testing of coal combustors and smelters in China to improve the accuracy of these estimates. (c) 2005 Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Dept Informat & Decis Sci, Argonne, IL 60439 USA. Tsing Hua Univ, Dept Environm Sci & Engn, Beijing 100084, Peoples R China. Argonne Natl Lab, Div Energy Syst, Ctr Transportat Res, Argonne, IL 60439 USA. Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550002, Peoples R China. RP Streets, DG (reprint author), Argonne Natl Lab, Dept Informat & Decis Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM dstreets@anl.gov RI Jiang, Jingkun/A-1076-2010; Tian, Hezhong/B-8413-2013; Feng, Xinbin/F-4512-2011; Wu, Ye/O-9779-2015; OI Feng, Xinbin/0000-0002-7462-8998; Streets, David/0000-0002-0223-1350 NR 81 TC 350 Z9 420 U1 35 U2 223 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 2005 VL 39 IS 40 BP 7789 EP 7806 DI 10.1016/j.atmosenv.2005.08.029 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 998IE UT WOS:000234311100010 ER PT J AU Levinson, R Berdahl, P Berhe, AA Akbari, H AF Levinson, R Berdahl, P Berhe, AA Akbari, H TI Effects of soiling and cleaning on the reflectance and solar heat gain of a light-colored roofing membrane SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE roofing; single-ply membrane; polyvinyl chloride (PVC); black carbon; organic carbon; biomass; fungi; algae; solar spectral reflectance; solar reflectance; solar absorptance; absorption; optical depth; soiling; cleaning; wiping; washing; rinsing; bleaching ID SPECTRAL OPTICAL-PROPERTIES; BUILDINGS; PIGMENTS AB A roof with high solar reflectance and high thermal emittance (e.g., a white roof) stays cool in the sun, reducing cooling power demand in a conditioned building and increasing summertime comfort in an unconditioned building. The high initial solar reflectance of a white membrane roof (circa 0.8) can be lowered by deposition of soot, dust, and/or biomass (e.g., fungi or algae) to about 0.6; degraded solar reflectances range from 0.3 to 0.8, depending on exposure. We investigate the effects of soiling and cleaning on the solar spectral reflectances and solar absorptances of 15 initially white or light-gray polyvinyl chloride membrane samples taken from roofs across the United States. Black carbon and organic carbon were the two identifiable strongly absorbing contaminants on the membranes. Wiping was effective at removing black carbon, and less so at removing organic carbon. Rinsing and/or washing removed nearly all of the remaining soil layer, with the exception of (a) thin layers of organic carbon and (b) isolated dark spots of biomass. Bleach was required to clear these last two features. At the most soiled location on each membrane, the ratio of solar reflectance to unsoiled solar reflectance (a measure of cleanliness) ranged from 0.41 to 0.89 for the soiled samples; 0.53 to 0.95 for the wiped samples; 0.74 to 0.98 for the rinsed samples; 0.79 to 1.00 for the washed samples; and 0.94 to 1.02 for the bleached samples. However, the influences of membrane soiling and cleaning on roof heat gain are better gauged by fractional variations in solar absorptance. Solar absorptance ratios (indicating solar heat gain relative to that of an unsoiled membrane) ranged from 1.4 to 3.5 for the soiled samples; 1.1 to 3.1 for the wiped samples; 1.0 to 2.0 for the rinsed samples; 1.0 to 1.9 for the washed samples; and 0.9 to 1.3 for the bleached samples. (c) 2005 Elsevier Ltd. All rights reserved. C1 Lawrence Berkeley Lab, Heat Isl Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ecosyst Sci Div, Berkeley, CA 94720 USA. RP Levinson, R (reprint author), Lawrence Berkeley Lab, Heat Isl Grp, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM RMLevinson@LBL.gov RI Berhe, Asmeret Asefaw/D-4179-2011 OI Berhe, Asmeret Asefaw/0000-0002-6986-7943 NR 26 TC 34 Z9 35 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 2005 VL 39 IS 40 BP 7807 EP 7824 DI 10.1016/j.atmosenv.2005.08.037 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 998IE UT WOS:000234311100011 ER PT J AU Porter, AE Nalla, RK Minor, A Jinschek, JR Kisielowski, C Radmilovic, V Kinney, JH Tomsia, AP Ritchie, RO AF Porter, AE Nalla, RK Minor, A Jinschek, JR Kisielowski, C Radmilovic, V Kinney, JH Tomsia, AP Ritchie, RO TI A transmission electron microscopy study of mineralization in age-induced transparent dentin SO BIOMATERIALS LA English DT Article DE dentin; transmission electron microscopy; mineralization; sclerotic; transparent; aging ID SILICON-SUBSTITUTED HYDROXYAPATITE; HUMAN ROOT DENTIN; RESOLUTION; DISSOLUTION; CRYSTALS; ENAMEL; BONE; RECONSTRUCTION; RADIATION; FRACTURE AB It is known that fractures are more likely to occur in altered teeth, particularly following restoration or endodontic repair; consequently, it is important to understand the structure of altered forms of dentin, the most abundant tissue in the human tooth, in order to better define the increased propensity for such fractures. Transparent (or sclerotic) dentin, wherein the dentinal tubules become occluded with mineral as a natural progressive consequence of aging, is one such altered form. In the present study, high-resolution transmission electron microscopy is used to investigate the effect of aging on the mineral phase of dentin. Such studies revealed that the intertubular mineral crystallites were smaller in transparent dentin, and that the intratubular mineral (larger crystals deposited within the tubules) was chemically similar to the surrounding intertubular mineral. Exit-wave reconstructed lattice-plane images suggested that the intratubular mineral had nanometer-size grains. These observations support a "dissolution and reprecipitation" mechanism for the formation of transparent dentin. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Natl Ctr Electron Microscopy, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Dept Mech Engn, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, UCB Joint Grad Grp Bioengn, Livermore, CA 94550 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. RP Ritchie, RO (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, 381 Hearst Min Bldg,MC 1760, Berkeley, CA 94720 USA. EM roritchie@lbl.gov RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 FU NIDCR NIH HHS [5R01 DE015633, P01DE09859] NR 45 TC 47 Z9 52 U1 1 U2 16 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-9612 J9 BIOMATERIALS JI Biomaterials PD DEC PY 2005 VL 26 IS 36 BP 7650 EP 7660 DI 10.1016/j.biomaterials.2005.05.059 PG 11 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 966AK UT WOS:000231991800016 PM 16005961 ER PT J AU Gourley, PL Hendricks, JK McDonald, AE Copeland, RG Barrett, KE Gourley, CR Naviaux, RK AF Gourley, PL Hendricks, JK McDonald, AE Copeland, RG Barrett, KE Gourley, CR Naviaux, RK TI Ultrafast nanolaser flow device for detecting cancer in single cells SO BIOMEDICAL MICRODEVICES LA English DT Article ID LIGHT-SCATTERING; BIOLOGICAL CELLS; LASER ACTION; LOCALIZATION; MITOCHONDRIA; GENERATION; APOPTOSIS AB Currently, pathologists rely on labor-intensive microscopic examination of tumor cells using staining techniques originally devised in the 1880s that depend heavily on specimen preparation and that can give false readings. Emerging BioMicroNanotechnologies (Gourley, 2005) have the potential to provide accurate, realtime, high throughput screening of tumor cells without invasive chemical reagents. These techniques are critical to advancing early detection, diagnosis, and treatment of disease. Using a new technique to rapidly assess the properties of cells flown through a nanolaser semiconductor device, we discovered a method to rapidly assess the respiratory health of a single mammalian cell. The key discovery was the elucidation of biophotonic differences in normal and transformed (cancer) mouse liver cells by using intracellular mitochondria as biomarkers for disease. This technique holds promise for detecting cancer at a very early stage and could nearly eliminate delays in diagnosis and treatment. C1 Sandia Natl Labs, Dept 1141, Albuquerque, NM 87185 USA. Univ Calif San Diego, Dept Med, San Diego, CA 92103 USA. Univ Calif San Diego, Dept Pediat, San Diego, CA 92103 USA. RP Gourley, PL (reprint author), Sandia Natl Labs, Dept 1141, MS 1413, Albuquerque, NM 87185 USA. EM Plgourl@sandia.gov NR 34 TC 20 Z9 20 U1 1 U2 11 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1387-2176 J9 BIOMED MICRODEVICES JI Biomed. Microdevices PD DEC PY 2005 VL 7 IS 4 BP 331 EP 339 DI 10.1007/s10544-005-6075-x PG 9 WC Engineering, Biomedical; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA 001DA UT WOS:000234512600008 PM 16404511 ER PT J AU Koppisch, AT Browder, CC Moe, AL Shelley, JT Kinke, BA Hersman, LE Iyer, S Ruggiero, CE AF Koppisch, AT Browder, CC Moe, AL Shelley, JT Kinke, BA Hersman, LE Iyer, S Ruggiero, CE TI Petrobactin is the primary siderophore synthesized by Bacillus anthracis str. Sterne under conditions of iron starvation SO BIOMETALS LA English DT Article DE bacillibactin; Bacillus anthracis; iron; petrobactin; siderophores ID BACTERIUM MARINOBACTER-HYDROCARBONOCLASTICUS; BIOSYNTHESIS; ACQUISITION; TRANSPORT; GROWTH AB The siderophores of Bacillus anthracis are critical for the pathogen's proliferation and may be necessary for its virulence. Bacillus anthracis str. Sterne cells were cultured in iron free media and the siderophores produced were isolated and purified using a combination of XAD-2 resin, reverse-phase FPLC, and size exclusion chromatography. A combination of H-1 and (NMR)-N-13 spectroscopy, UV spectroscopy and ESI-MS/MS fragmentation were used to identify the primary siderophore as petrobactin, a catecholate species containing unusual 3,4-dihydroxybenzoate moieties, previously only identified in extracts of Marinobacter hydrocarbonoclasticus. A secondary siderophore was observed and structural analysis of this species is consistent with that reported for bacillibactin, a siderophore observed in many species of bacilli. This is the first structural characterization of a siderophore from B. anthracis, as well as the first characterization of a 3,4-DHB containing catecholate in a pathogen. C1 Los Alamos Natl Lab, Chem Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Biosci Div B4, Los Alamos, NM 87545 USA. Ft Lewis Coll, Dept Chem, Durango, CO 81301 USA. RP Ruggiero, CE (reprint author), Los Alamos Natl Lab, Chem Div, Los Alamos, NM 87545 USA. EM ruggiero@lanl.gov RI Browder, Cindy/F-4700-2017 NR 25 TC 57 Z9 58 U1 1 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0966-0844 J9 BIOMETALS JI Biometals PD DEC PY 2005 VL 18 IS 6 BP 577 EP 585 DI 10.1007/s10534-005-1782-6 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 998KL UT WOS:000234317300003 PM 16388397 ER PT J AU Zhou, Y Pearson, JE Auerbach, A AF Zhou, Y Pearson, JE Auerbach, A TI phi-Value analysis of a linear, sequential reaction mechanism: Theory and application to ion channel gating SO BIOPHYSICAL JOURNAL LA English DT Article ID ACETYLCHOLINE-RECEPTOR CHANNELS; TRANSITION-STATE; TRANSMEMBRANE SEGMENT; DYNAMICS AB We derive the analytical form of a rate-equilibrium free-energy relationship ( with slope phi) for a bounded, linear chain of coupled reactions having arbitrary connecting rate constants. The results confirm previous simulation studies showing that phi-values reflect the position of the perturbed reaction within the chain, with reactions occurring earlier in the sequence producing higher phi-values than those occurring later in the sequence. The derivation includes an expression for the transmission coefficients of the overall reaction based on the rate constants of an arbitrary, discrete, finite Markov chain. The results indicate that experimental phi-values can be used to calculate the relative heights of the energy barriers between intermediate states of the chain but provide no information about the energies of the wells along the reaction path. Application of the equations to the case of diliganded acetylcholine receptor channel gating suggests that the transition-state ensemble for this reaction is nearly. at. Although this mechanism accounts for many of the basic features of diliganded and unliganded acetylcholine receptor channel gating, the experimental rate-equilibrium free-energy relationships appear to be more linear than those predicted by the theory. C1 SUNY Buffalo, Ctr Single Mol Biophys, Buffalo, NY 14214 USA. SUNY Buffalo, Dept Physiol & Biophys, Buffalo, NY 14214 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Auerbach, A (reprint author), SUNY Buffalo, Ctr Single Mol Biophys, Buffalo, NY 14214 USA. EM auerbach@buffalo.edu FU NINDS NIH HHS [NS-36554, R01 NS036554, R37 NS023513, R56 NS023513, NS-23513, R01 NS023513] NR 18 TC 58 Z9 59 U1 2 U2 3 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD DEC PY 2005 VL 89 IS 6 BP 3680 EP 3685 DI 10.1529/biophysj.105.067215 PG 6 WC Biophysics SC Biophysics GA 988JO UT WOS:000233590800010 PM 16183877 ER PT J AU Zhao, XC Striolo, A Cummings, PT AF Zhao, XC Striolo, A Cummings, PT TI C-60 binds to and deforms nucleotides SO BIOPHYSICAL JOURNAL LA English DT Article ID WATER-SOLUBLE FULLERENE; WALL CARBON NANOTUBES; MOLECULAR-DYNAMICS; PULMONARY TOXICITY; NANOMATERIALS; SIMULATION; ACID; RATS; DNA AB Atomistic molecular dynamics simulations are performed for up to 20 ns to monitor the formation and the stability of complexes composed of single- or double-strand DNA molecules and C-60 in aqueous solution. Despite the hydrophobic nature of C-60, our results show that fullerenes strongly bind to nucleotides. The binding energies are in the range -27 to -42 kcal/mol; by contrast, the binding energy of two fullerenes in aqueous solution is only -7.5 kcal/ mol. We observe the displacement of water molecules from the region between the nucleotides and the fullerenes and we attribute the large favorable interaction energies to hydrophobic interactions. The features of the DNA-C-60 complexes depend on the nature of the nucleotides: C-60 binds to double-strand DNA, either at the hydrophobic ends or at the minor groove of the nucleotide. C-60 binds to single-strand DNA and deforms the nucleotides significantly. Unexpectedly, when the double-strand DNA is in the A-form, fullerenes penetrate into the double helix from the end, form stable hybrids, and frustrate the hydrogen bonds between endgroup basepairs in the nucleotide. When the DNA molecule is damaged (specifically, a gap was created by removing a piece of the nucleotide from one helix), fullerenes can stably occupy the damaged site. We speculate that this strong association may negatively impact the self-repairing process of the double-strand DNA. Our results clearly indicate that the association between C-60 and DNA is stronger and more favorable than that between two C-60 molecules in water. Therefore, our simulation results suggest that C-60 molecules have potentially negative impact on the structure, stability, and biological functions of DNA molecules. C1 Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Nanomat Theory Inst, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Chem Engn, Nashville, TN USA. RP Zhao, XC (reprint author), Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Nanomat Theory Inst, Oak Ridge, TN 37831 USA. EM zhaox@ornl.gov RI Striolo, Alberto/G-2926-2011; Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 32 TC 81 Z9 88 U1 1 U2 12 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD DEC PY 2005 VL 89 IS 6 BP 3856 EP 3862 DI 10.1529/biophysj.105.064410 PG 7 WC Biophysics SC Biophysics GA 988JO UT WOS:000233590800024 PM 16183879 ER PT J AU Jiang, Y Pjesivac-Grbovic, J Cantrell, C Freyer, JP AF Jiang, Y Pjesivac-Grbovic, J Cantrell, C Freyer, JP TI A multiscale model for avascular tumor growth SO BIOPHYSICAL JOURNAL LA English DT Article ID DEPENDENT KINASE INHIBITORS; MULTICELLULAR SPHEROIDS; DIFFERENTIAL ADHESION; MATHEMATICAL-MODELS; OXYGEN-CONSUMPTION; FLUID PRESSURE; CELLS; GLUCOSE; STRESS; SIMULATION AB The desire to understand tumor complexity has given rise to mathematical models to describe the tumor microenvironment. We present a new mathematical model for avascular tumor growth and development that spans three distinct scales. At the cellular level, a lattice Monte Carlo model describes cellular dynamics (proliferation, adhesion, and viability). At the subcellular level, a Boolean network regulates the expression of proteins that control the cell cycle. At the extracellular level, reaction-diffusion equations describe the chemical dynamics (nutrient, waste, growth promoter, and inhibitor concentrations). Data from experiments with multicellular spheroids were used to determine the parameters of the simulations. Starting with a single tumor cell, this model produces an avascular tumor that quantitatively mimics experimental measurements in multicellular spheroids. Based on the simulations, we predict: 1), the microenvironmental conditions required for tumor cell survival; and 2), growth promoters and inhibitors have diffusion coefficients in the range between 10(-6) and 10(-7) cm(2)/ h, corresponding to molecules of size 80-90 kDa. Using the same parameters, the model also accurately predicts spheroid growth curves under different external nutrient supply conditions. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Tennessee, Dept Comp Sci, Knoxville, TN USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM USA. RP Jiang, Y (reprint author), Los Alamos Natl Lab, Div Theoret, MS B284, Los Alamos, NM 87545 USA. EM jiang@lanl.gov FU NCI NIH HHS [CA-89255, CA-108553, CA-71898, R01 CA071898, R01 CA089255, R21 CA108853] NR 47 TC 179 Z9 185 U1 5 U2 33 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD DEC PY 2005 VL 89 IS 6 BP 3884 EP 3894 DI 10.1529/biophysj.105.060640 PG 11 WC Biophysics SC Biophysics GA 988JO UT WOS:000233590800027 PM 16199495 ER PT J AU Wyman, CE Dale, BE Elander, RT Holtzapple, M Ladisch, MR Lee, YY AF Wyman, CE Dale, BE Elander, RT Holtzapple, M Ladisch, MR Lee, YY TI Coordinated development of leading biomass pretreatment technologies SO BIORESOURCE TECHNOLOGY LA English DT Article DE corn stover; pretreatment; hydrolysis; sugars; enzymatic digestion; biomass ID RECYCLED PERCOLATION PROCESS; ENZYMATIC-HYDROLYSIS; LIME PRETREATMENT; CORN STOVER; LIGNOCELLULOSIC MATERIALS; HERBACEOUS BIOMASS; HYDROGEN-PEROXIDE; PRESSURE COOKING; AQUEOUS AMMONIA; LIGNIN REMOVAL AB For the first time, a single source of cellulosic biomass was pretreated by leading technologies using identical analytical methods to provide comparative performance data. In particular, ammonia explosion, aqueous ammonia recycle, controlled pH, dilute acid, flowthrough, and time approaches were applied to prepare corn stover for subsequent biological conversion to sugars through a Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) among Auburn University, Dartmouth College, Michigan State University, the National Renewable Energy Laboratory, Purdue University, and Texas A&M University. An Agricultural and Industrial Advisory Board provided guidance to the project. Pretreatment conditions were selected based on the extensive experience of the team with each of the technologies, and the resulting fluid and solid streams were characterized using standard methods. The data were used to close material balances, and energy balances were estimated for all processes. The digestibilities of the solids by a controlled supply of cellulase enzyme and the fermentability of the liquids were also assessed and used to guide selection of optimum pretreatment conditions. Economic assessments were applied based on the performance data to estimate each pretreatment cost on a consistent basis. Through this approach, comparative data were developed on sugar recovery from hemicellulose and cellulose by the combined pretreatment and enzymatic hydrolysis operations when applied to corn stover. This paper introduces the project and summarizes the shared methods for papers reporting results of this research in this special edition of Bioresource Technology. (c) 2005 Elsevier Ltd. All rights reserved. C1 Dartmouth Coll, Hanover, NH 03755 USA. Michigan State Univ, E Lansing, MI 48824 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Texas A&M Univ, College Stn, TX 77843 USA. Purdue Univ, W Lafayette, IN 47907 USA. Auburn Coll, Auburn, AL 36849 USA. RP Wyman, CE (reprint author), Dartmouth Coll, Hanover, NH 03755 USA. EM charles.e.wyman@dartmouth.edu NR 54 TC 697 Z9 751 U1 23 U2 250 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0960-8524 J9 BIORESOURCE TECHNOL JI Bioresour. Technol. PD DEC PY 2005 VL 96 IS 18 BP 1959 EP 1966 DI 10.1016/j.biortech.2005.01.010 PG 8 WC Agricultural Engineering; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA 962RK UT WOS:000231749700001 PM 16112483 ER PT J AU Eggeman, T Elander, RT AF Eggeman, T Elander, RT TI Process and economic analysis of pretreatment technologies SO BIORESOURCE TECHNOLOGY LA English DT Article DE pretreatment; economics; bioethanol AB Five pretreatment processes (dilute acid, hot water, ammonia fiber explosion (AFEX), ammonia recycle percolation (ARP), and lime) for the liberation of sugars from corn stover are compared on a consistent basis. Each pretreatment process model was embedded in a full bioethanol facility model so that systematic effects for variations in pretreatment were accounted in the overall process. Economic drivers influenced by pretreatment are yield of both five and six carbon sugars, solids concentration, enzyme loading and hemicellulase activity. All of the designs considered were projected to be capital intensive. Low cost pretreatment reactors in some pretreatment processes are often counterbalanced by higher costs associated with pretreatment catalyst recovery or higher costs for ethanol product recovery. The result is little differentiation between the projected economic performances of the pretreatment options. Additional process performance data, especially involving the identification of optimal enzyme blends for each pretreatment approach and conditioning requirements of hydrolyzates at process-relevant sugar concentrations resulting from each pretreatment may lead to greater differentiation in projected process economics. (c) 2005 Elsevier Ltd. All rights reserved. C1 Neoter Int, Lakewood, CO 80228 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Eggeman, T (reprint author), Neoter Int, Lakewood, CO 80228 USA. EM time@frii.com NR 4 TC 308 Z9 319 U1 2 U2 75 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0960-8524 J9 BIORESOURCE TECHNOL JI Bioresour. Technol. PD DEC PY 2005 VL 96 IS 18 BP 2019 EP 2025 DI 10.1016/j.biortech.2005.01.017 PG 7 WC Agricultural Engineering; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA 962RK UT WOS:000231749700008 PM 16112490 ER PT J AU Wyman, CE Dale, BE Elander, RT Holtzapple, M Ladisch, MR Lee, YY AF Wyman, CE Dale, BE Elander, RT Holtzapple, M Ladisch, MR Lee, YY TI Comparative sugar recovery data from laboratory scale application of leading pretreatment technologies to corn stover SO BIORESOURCE TECHNOLOGY LA English DT Article DE corn stover; pretreatment; hydrolysis; sugars; enzymatic digestion AB Biological processing of cellulosic biomass to fuels and chemicals would open up major new agricultural markets and provide powerful societal benefits, but pretreatment operations essential to economically viable yields have a major impact on costs and performance of the entire system. However, little comparative data is available on promising pretreatments. To aid in selecting appropriate systems, leading pretreatments based on ammonia explosion, aqueous ammonia recycle, controlled pH, dilute acid, flowthrough, and lime were evaluated in a coordinated laboratory program using a single source of corn stover, the same cellulase enzyme, shared analytical methods, and common data interpretation approaches to make meaningful comparisons possible for the first time. Each pretreatment made it possible to subsequently achieve high yields of glucose from cellulose by cellulase enzymes, and the cellulase formulations used were effective in solubilizing residual xylan left in the solids after each pretreatment. Thus, overall sugar yields from hemicellulose and cellulose in the coupled pretreatment and enzymatic hydrolysis operations were high for all of the pretreatments with corn stover. In addition, high-pH methods were found to offer promise in reducing cellulase use provided hemicellulase activity can be enhanced. However, the substantial differences in sugar release patterns in the pretreatment and enzymatic hydrolysis operations have important implications for the choice of process, enzymes, and fermentative organisms. (c) 2005 Elsevier Ltd. All rights reserved. C1 Dartmouth Coll, Hanover, NH 03755 USA. Michigan State Univ, E Lansing, MI 48824 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Texas A&M Univ, College Stn, TX 77843 USA. Purdue Univ, W Lafayette, IN 47907 USA. Auburn Coll, Auburn, AL 36849 USA. RP Wyman, CE (reprint author), Dartmouth Coll, Hanover, NH 03755 USA. EM charles.wyman@dartmouth.edu NR 3 TC 293 Z9 308 U1 5 U2 67 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0960-8524 J9 BIORESOURCE TECHNOL JI Bioresour. Technol. PD DEC PY 2005 VL 96 IS 18 BP 2026 EP 2032 DI 10.1016/j.biortech.2005.01.018 PG 7 WC Agricultural Engineering; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA 962RK UT WOS:000231749700009 PM 16112491 ER PT J AU Busa, B Miller, L Rubin, C Qin, YX Judex, S AF Busa, B Miller, L Rubin, C Qin, YX Judex, S TI Rapid establishment of chemical and mechanical properties during lamellar bone formation SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE cortical bone; modeling; growth; nanoindentation; infrared spectroscopy; rat ID AGE-RELATED-CHANGES; TRANSFORM INFRARED-SPECTROSCOPY; CORTICAL BONE; CYNOMOLGUS MONKEYS; CALCIUM-PHOSPHATE; SUBCHONDRAL BONE; TRABECULAR BONE; CROSS-LINKS; COLLAGEN; MINERALIZATION AB The development of prophylaxes and treatments of bone diseases that can effectively increase the strength of bone as a structure necessitates a better understanding of the time course by which chemical properties define the stiffness of the material during primary and secondary mineralization. It was hypothesized that these processes would be relatively slow in the actively growing skeleton. Seven-week-old Sprague-Dawley female rats (n = 8) were injected with multiple fluorochrome labels over a time span of 3 weeks and killed. Chemical and mechanical properties of the tibial mid-diaphysis were spatially characterized between the endocortical and periosteal surface by in situ infrared microspectroscopy and nanoindentation. The phosphate-to-protein ratio of bone 2-6 days old was 20% smaller at the periosteal surface and 22% smaller at the endocortical surface (P < 0.05 each) compared to older intracortical regions. The ratios of carbonate to protein, crystallinity, type A/type B carbonate, collagen cross-linking, and bone elastic modulus did not differ significantly between bone 2-6, 10-14, and 8-22 days old and intracortical regions. Intracortical properties of 10-week-old rats, except for the carbonate-to-protein ratio which was 23% smaller (P < 0.01), were not significantly different from intracortical matrix properties of young adult rats (5 months, n = 4). Spatially, the phosphate-to-protein ratio (R-2 = 0.33) and the phosphate-to-carbonate ratio (R-2 = 0.55) were significantly correlated with bone material stiffness, while the combination of all chemical parameters raised the R-2 value to 0.83. These data indicate that lamellar bone has the ability to quickly establish its mechanical and chemical tissue properties during primary and secondary mineralization even when the skeleton experiences rapid growth. C1 SUNY Stony Brook, Dept Biomed Engn, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Judex, S (reprint author), SUNY Stony Brook, Dept Biomed Engn, Stony Brook, NY 11794 USA. EM stefan.judex@sunysb.edu NR 52 TC 52 Z9 54 U1 0 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD DEC PY 2005 VL 77 IS 6 BP 386 EP 394 DI 10.1007/s00223-005-0148-y PG 9 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 995ZL UT WOS:000234144100007 PM 16362460 ER PT J AU Liedahl, DA Torres, DF AF Liedahl, DA Torres, DF TI Atomic X-ray spectroscopy of accreting black holes SO CANADIAN JOURNAL OF PHYSICS LA English DT Review ID ACTIVE GALACTIC NUCLEI; DUSTY WARM ABSORBER; K-ALPHA-EMISSION; ADVECTION-DOMINATED ACCRETION; IRON LINE REVERBERATION; XMM-NEWTON; CYGNUS X-1; SEYFERT-1 GALAXIES; OPTICALLY THIN; NEUTRON-STAR AB Current astrophysical research suggests that the most persistently luminous objects in the Universe are powered by the flow of matter through accretion disks onto black holes. Accretion disk systems are observed to emit copious radiation across the electromagnetic spectrum, each energy band providing access to rather distinct regimes of physical conditions and geometric scale. X-ray emission probes the innermost regions of the accretion disk, where relativistic effects prevail. While this has been known for decades, it also has been acknowledged that inferring physical conditions in the relativistic regime from the behavior of the X-ray continuum is problematic and not satisfactorily constraining. With the discovery in the 1990s of iron X-ray lines bearing signatures of relativistic distortion came the hope that such emission would more firmly constrain models of disk accretion near black holes, as well as provide observational criteria by which to test general relativity in the strong field limit. Here, we provide an introduction to this phenomenon. While the presentation is intended to be primarily tutorial in nature, we aim also to acquaint the reader with trends in current research. To achieve these ends, we present the basic applications of general relativity that pertain to X-ray spectroscopic observations of black hole accretion-disk systems, focusing on the Schwarzschild and Kerr solutions to the Einstein field equations. To this, we add treatments of the fundamental concepts associated with the theoretical and modeling aspects of accretion disks, as well as relevant topics from observational and theoretical X-ray spectroscopy. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Liedahl, DA (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,L-473, Livermore, CA 94550 USA. EM liedahl1@llnl.gov RI Torres, Diego/O-9422-2016 OI Torres, Diego/0000-0002-1522-9065 NR 237 TC 7 Z9 7 U1 1 U2 1 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD DEC PY 2005 VL 83 IS 12 BP 1177 EP 1240 DI 10.1139/P05-062 PG 64 WC Physics, Multidisciplinary SC Physics GA 010WY UT WOS:000235229800001 ER PT J AU Burns, PC AF Burns, PC TI U6+ minerals and inorganic compounds: Insights into an expanded structural hierarchy of crystal structures SO CANADIAN MINERALOGIST LA English DT Article; Proceedings Paper CT Joint Annual Meeting of the Geological-Association-of-Canada/Mineralogical-Association-of-Canada CY MAY, 2005 CL Halifax, CANADA SP Geol Assoc Canada, Mineralog Assoc Canada DE uranium; actinide; crystal structure; structural hierarchy; nuclear waste ID POWDER DIFFRACTION DATA; URANYL OXIDE HYDRATE; SPENT NUCLEAR-FUEL; INITIO STRUCTURE DETERMINATION; SHEET ANION-TOPOLOGIES; NEUTRON-DIFFRACTION; OPEN-FRAMEWORK; HYDROTHERMAL SYNTHESIS; X-RAY; RIETVELD REFINEMENT AB The crystal structures of uranyl minerals and inorganic uranyl compounds are important for understanding the genesis of U deposits. the interaction of U mine and mill tailings with the environment, transport of actinides in soils and the vadose zone, the performance of geological repositories for nuclear waste-and for the development of advanced materials with novel applications. Over the past decade. the number of inorganic uranyl compounds (including minerals) with known structures has more than doubled. and reconsideration of the structural hierarchy of uranyl compounds is warranted. Here, 368 inorganic crystal structures that contain essential U6+ are considered (of which 89 are minerals). They are arranged oil the basis of the topological details of their Structural units, which are formed by the polymerization of polyhedra containing higher-valence cations. Overarching Structural categories correspond to those based upon isolated polyhedra (8). finite clusters (43). chains (57). sheets (204). and frameworks (56) of polyhedra. Within these categories. structures are organized and compared upon the basis of either their graphical representations. or in the case of sheets involving sharing of edges of polyhedra, upon the topological arrangement of anions within the sheets. C1 Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Burns, PC (reprint author), Univ Notre Dame, Dept Civil Engn & Geol Sci, 156 Fitzpatrick Hall, Notre Dame, IN 46556 USA. EM pburns@ndu.edu RI Burns, Peter/J-3359-2013; OI Burns, Peter/0000-0002-2319-9628 NR 312 TC 348 Z9 349 U1 15 U2 105 PU MINERALOGICAL ASSOC CANADA PI OTTAWA PA PO BOX 78087, MERILINE POSTAL OUTLET, 1460 MERIVALE RD, OTTAWA, ONTARIO K2E 1B1, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD DEC PY 2005 VL 43 BP 1839 EP 1894 DI 10.2113/gscanmin.43.6.1839 PN 6 PG 56 WC Mineralogy SC Mineralogy GA 022XZ UT WOS:000236090800003 ER PT J AU Shen, S DeNardo, GL Yuan, A Hartmann-Siantar, C O'Donnell, RT DeNardo, SJ AF Shen, S DeNardo, GL Yuan, A Hartmann-Siantar, C O'Donnell, RT DeNardo, SJ TI Splenic volume change and nodal tumor response in non-Hodgkin's lymphoma patients after radioimmunotherapy using radiolabeled Lym-1 antibody SO CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS LA English DT Article DE splenomegaly; radioimmunotherapy; radiation dosimetry; lymphoma; cancer therapy ID FRACTIONATED RADIOIMMUNOTHERAPY; PRACTICAL DETERMINATION; I-131-LYM-1 ANTIBODY; RADIATION-DOSIMETRY; CLINICAL-TRIAL; CU-67-2IT-BAT-LYM-1; THERAPY; PHARMACOKINETICS; MALIGNANCIES; TOXICITY AB Splenomegaly is frequently found in non-Hodgkin's lymphoma (NHL) patients. This study evaluated the implications of splenic volume change in response to radioimmunotherapy (RIT) using radiolabeled Lym-1 antibody. Methods: Twenty-nine NHL patients treated with radiolabeled-Lym-1 and 9 breast cancer patients, the reference group, treated with radiolabeled ChL6, BrE-3, or m170, were analyzed using X-ray computer tomography (CT) splenic images obtained before and after RIT Patient-specific radiation doses to the spleen were determined using actual splenic volume determined by CT and body weight. Results: Of 29 NHL patients, 13 that had splenic volumes equal or less than 310 mL, there was little or no change in splenic volume after RIT, despite splenic radiation doses as high as 23.1 Gy (median 8.0 Gy). Similarly, in a reference group of 9 breast cancer patients, there was little or no change in splenic volume after RIT, despite doses as high as 14.4 Gy (median 11.5 Gy). In the remaining 16 NHL patients, splenic volumes decreased in 13 patients, with initial volumes of 380-1400 mL, by 68-548 mL despite splenic radiation doses as low as 1.1 Gy (median 3.2 Gy); splenic volumes increased in the other 3 patients after RIT. Although not statistically significant in this small series, therapeutic remission, defined conventionally by nodal tumor response, was more likely when splenic volume decreased after RIT. All 10 NHL patients with greater than a 15% decrease in their splenic volumes after RIT had nodal tumor response (5 complete response, 5 partial response). There were 12 responders (5 complete response and 7 partial response) in 19 NHL patients with less than a 15% decrease in splenic volume after RIT Conclusions: Splenic volume decreased in NHL patients with splenomegaly, despite splenic radiation dose as low as 1.1 Gy. In the absence of splenomegaly, splenic volume did not decrease, even after much higher radiation doses. RIT with radiolabeled-Lym-1 may benefit NHL patients with splenomegaly, with reduction in splenic volume likely owing to a therapeutic effect on malignant lymphocytes. C1 Univ Alabama, Dept Radiat Oncol, Birmingham, AL 35294 USA. Univ Calif Davis, Div Hematol Oncol, Dept Internal Med, Sacramento, CA 95817 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Vet Adm No Calif Healthcare Syst, Mather, CA USA. RP Shen, S (reprint author), Univ Alabama, Dept Radiat Oncol, 1824 6th Ave S,WTI Room 124, Birmingham, AL 35294 USA. EM sshen@uabmc.edu FU NCI NIH HHS [CA 47829] NR 32 TC 4 Z9 4 U1 0 U2 0 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1084-9785 J9 CANCER BIOTHER RADIO JI Cancer Biother. Radiopharm. PD DEC PY 2005 VL 20 IS 6 BP 662 EP 670 DI 10.1089/cbr.2005.20.662 PG 9 WC Oncology; Medicine, Research & Experimental; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Research & Experimental Medicine; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging GA 002KS UT WOS:000234610900010 PM 16398618 ER PT J AU Ellwood-Yen, K Graeber, TG Wongvipat, J Iruela-Arispe, ML Zhang, JF Matusik, R Thomas, GV Sawyers, CL AF Ellwood-Yen, K Graeber, TG Wongvipat, J Iruela-Arispe, ML Zhang, JF Matusik, R Thomas, GV Sawyers, CL TI Myc-driven murine prostate cancer shares molecular features with human prostate tumors (vol 4, pg 223, 2003) SO CANCER CELL LA English DT Correction C1 Univ Calif Los Angeles, Dept Pathol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Med, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Urol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Mol & Med Pharmacol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, DOE Inst Genom & Proteom, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, David Geffen Sch Med, Jonsson Comprehens Canc Ctr, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Howard Hughes Med Inst, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Mol Cell & Dev Biol, Los Angeles, CA 90095 USA. Vanderbilt Univ, Sch Med, Dept Urol, Nashville, TN 37232 USA. Univ Alabama, Dept Dermatol, Birmingham, AL 35294 USA. RP Sawyers, CL (reprint author), Univ Calif Los Angeles, Dept Pathol, Los Angeles, CA 90095 USA. EM gvthomas@mednet.ucla.edu; csawyers@mednet.ucla.edu RI Sawyers, Charles/G-5327-2016 NR 3 TC 1 Z9 1 U1 0 U2 4 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 1535-6108 J9 CANCER CELL JI Cancer Cell PD DEC PY 2005 VL 8 IS 6 BP 485 EP 485 DI 10.1016/j.ccr.2005.11.010 PG 1 WC Oncology; Cell Biology SC Oncology; Cell Biology GA 996HE UT WOS:000234164200008 ER PT J AU Yan, XM Kwon, S Contreras, AM Koebel, MM Bokor, J Somorjai, GA AF Yan, XM Kwon, S Contreras, AM Koebel, MM Bokor, J Somorjai, GA TI Fabrication of dense arrays of platinum nanowires on silica, alumina, zirconia and ceria surfaces as 2-D model catalysts SO CATALYSIS LETTERS LA English DT Article DE platinum nanowires; two-dimensional model catalysts; oxide-supported platinum nanowires ID SIZE-REDUCTION LITHOGRAPHY; SUPPORTED PLATINUM; METAL-CLUSTERS; CO OXIDATION; HYDROGENATION; NANOFABRICATION; TECHNOLOGY; DEPOSITION; KINETICS AB High-density arrays of platinum nanowires with dimensions 20 nm x 5 nm x 12 mu m (width x height x length) have been produced on planar oxide thin films of silica, alumina, zirconia, and ceria. In this multi-step fabrication process, sub-20 nm single crystalline silicon nanowires were fabricated by size reduction lithography. The Si nanowire patterns were then replicated to produce a high density of Pt nanowires by nanoimprint lithography. The width and height of the Pt nanowires are uniform and are controlled with nanometer precision. The Pt surface area is larger than 2 cm(2) on a 5 x 5 cm(2) oxide substrate. The catalytic oxidation of CO was carried out on zirconia-supported Pt nanowires. The reaction conditions (100 Torr O-2, 40 Torr CO, 513-593 K) and vacuum annealing (1023 K) did not change the nanowire structures. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Yan, XM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Bokor, Jeffrey/A-2683-2011 NR 22 TC 20 Z9 20 U1 3 U2 16 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1011-372X J9 CATAL LETT JI Catal. Lett. PD DEC PY 2005 VL 105 IS 3-4 BP 127 EP 132 DI 10.1007/s10562-005-8681-x PG 6 WC Chemistry, Physical SC Chemistry GA 985BO UT WOS:000233351300001 ER PT J AU Kim, DH Chin, YH Kwak, JH Szanyi, J Peden, CHF AF Kim, DH Chin, YH Kwak, JH Szanyi, J Peden, CHF TI Changes in ba phases in BaO/Al2O3 upon thermal aging and H2O treatment SO CATALYSIS LETTERS LA English DT Article DE BaO/Al2O3; BaAl2O4; lean NOx trap; NO2 TPD; NOx storage; nitric oxide ID NOX STORAGE-REDUCTION; CATALYSTS AB The effects of thermal aging and H2O treatment on the physicochemical properties of BaO/Al2O3 (the NOx storage component in the lean NOx trap systems) were investigated by means of X-ray diffraction (XRD), BET, TEM/EDX and NO2 TPD. Thermal aging at 1000 degrees C for 10 h converted dispersed BaO/BaCO3 on Al2O3 into low surface area crystalline BaAl2O4. TEM/EDX and XRD analysis showed that H2O treatment at room temperature facilitated a dissolution/reprecipitation process, resulting in the formation of a highly crystalline BaCO3 phase segregated from the Al2O3 support. Crystalline BaCO3 was formed from conversion of both BaAl2O4 and a dispersed BaO/BaCO3 phase, initially present on the Al2O3 support material after calcinations at 1000 and 500 degrees C, respectively. Such a phase change proceeded rapidly for dispersed BaO/BaCO3/Al2O3 samples calcined at relatively low temperatures with large BaCO3 crystallites observed in XRD within 10 min after contacting the sample with water. Significantly, we also find that the change in barium phase occurs even at room temperature in an ambient atmosphere by contact of the sample with moisture in the air, although the rate is relatively slow. These phenomena imply that special care to prevent the water contact must be taken during catalyst synthesis/storage, and during realistic operation of Pt/BaO/Al2O3 NOx trap catalysts since both processes involve potential exposure of the material to CO2 and liquid and/or vapor H2O. Based on the results, a model that describes the behavior of Ba-containing species upon thermal aging and H2O treatment is proposed. C1 Inst Interfacial Catalysis, Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kim, DH (reprint author), Inst Interfacial Catalysis, Pacific NW Natl Lab, 902 Battelle Blvd MSIN K8-93,POB 999, Richland, WA 99352 USA. EM do.kim@pnl.gov; chuck.peden@pnl.gov RI Kwak, Ja Hun/J-4894-2014; Kim, Do Heui/I-3727-2015; OI Peden, Charles/0000-0001-6754-9928 NR 15 TC 30 Z9 32 U1 1 U2 12 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1011-372X J9 CATAL LETT JI Catal. Lett. PD DEC PY 2005 VL 105 IS 3-4 BP 259 EP 268 DI 10.1007/s10562-005-8700-y PG 10 WC Chemistry, Physical SC Chemistry GA 985BO UT WOS:000233351300020 ER PT J AU Langan, P Sukumar, N Nishiyama, Y Chanzy, H AF Langan, P Sukumar, N Nishiyama, Y Chanzy, H TI Synchrotron X-ray structures of cellulose I-beta and regenerated cellulose II at ambient temperature and 100 K SO CELLULOSE LA English DT Article DE cellulose II; cellulose I-beta; crystal structure; fiber diffraction; Fortisan; low temperature; regenerated cellulose; X-ray diffraction ID NEUTRON FIBER DIFFRACTION; HYDROGEN-BONDING SYSTEM; THERMAL-EXPANSION; CRYSTAL-STRUCTURE; COEFFICIENTS; PHASE AB Synchrotron X- ray data have been collected to 1.4 angstrom resolution at the NE-CAT beam-line at the Advanced Photon Source from fibers of cellulose I-beta and regenerated cellulose II (Fortisan) at ambient temperature and at 100 K in order to understand the effects of low temperature on cellulose more thoroughly. Crystal structures have been determined at each temperature. The unit cell of regenerated cellulose II contracted, with decreasing temperature, by 0.25%, 0.22% and 0.1% along the a, b, and c axes, respectively, whereas that of cellulose Ib contracted only in the direction of the a axis, by 0.9%. The value of 4.6 x 10(-5) K-1 for the thermal expansion coefficient of cellulose Ib in the a axis direction can be explained by simple harmonic molecular oscillations and the lack of hydrogen-bonding in this direction. The molecular conformations of each allomorph are essential unchanged by cooling to 100 K. The room temperature crystal structure of regenerated cellulose II is essentially identical to the crystal structure of mercerized cellulose II. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Argonne Natl Lab, NE CAT, Argonne, IL 60439 USA. Univ Grenoble 1, CNRS, Ctr Rech Macromol Vegetales, F-38041 Grenoble, France. RP Langan, P (reprint author), Los Alamos Natl Lab, Biosci Div, POB 1663, Los Alamos, NM 87545 USA. EM langan_paul@lanl.gov RI Chanzy, Henri/A-3526-2012; Nishiyama, Yoshiharu/A-3492-2012; Langan, Paul/N-5237-2015 OI Nishiyama, Yoshiharu/0000-0003-4069-2307; Langan, Paul/0000-0002-0247-3122 NR 29 TC 61 Z9 63 U1 1 U2 44 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0969-0239 J9 CELLULOSE JI Cellulose PD DEC PY 2005 VL 12 IS 6 BP 551 EP 562 DI 10.1007/s10570-005-9006-3 PG 12 WC Materials Science, Paper & Wood; Materials Science, Textiles; Polymer Science SC Materials Science; Polymer Science GA 995ZM UT WOS:000234144200001 ER PT J AU Jensen, TR Christensen, AN Hanson, JC AF Jensen, TR Christensen, AN Hanson, JC TI Hydrothermal transformation of the calcium aluminum oxide hydrates CaAl2O4 center dot 10H(2)O and Ca2Al2O5 center dot 8H(2)O to Ca3Al2(OH)(12) investigated by in situ synchrotron X-ray powder diffraction SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE hydration products; calcium aluminate cement; hydrogamet; X-ray diffraction ID CEMENTS AB The hydrothermal transformation of calcium aluminate hydrates were investigated by in situ synchrotron X-ray powder diffraction in the temperature range 25 to 170 degrees C. This technique allowed the study of the detailed reaction mechanism and identification of intermediate phases. The material CaAl2O4 center dot 10H(2)O converted to Ca3Al2(OH)(12) and amorphous aluminum hydroxide. Ca4Al2O5 center dot 8H(2)O transformed via the intermediate phase Ca(4)Al(2)O(7)center dot 13H(2)O to Ca3Al2(OH)(12) and gibbsite, Al(OH)(3). The phase Ca4Al2O7 center dot 19H(2)O reacted via the same intermediate phase to Ca3Al2(OH)(12) and mainly amorphous aluminum hydroxide. The powder pattern of the intermediate phase is reported. (c) 2004 Elsevier Ltd. All rights reserved. C1 Aarhus Univ, Dept Chem, Interdisciplinary Nanosci Ctr, DK-8000 Aarhus, Denmark. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Jensen, TR (reprint author), Aarhus Univ, Dept Chem, Interdisciplinary Nanosci Ctr, Langelandsgade 140, DK-8000 Aarhus, Denmark. EM trji@chem.au.dk RI Chen, Wei/A-5694-2010; Hanson, jonathan/E-3517-2010; OI Jensen, Torben Rene/0000-0002-4278-3221 NR 22 TC 24 Z9 24 U1 1 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD DEC PY 2005 VL 35 IS 12 BP 2300 EP 2309 DI 10.1016/j.cemconres.2004.10.034 PG 10 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 993GP UT WOS:000233942900009 ER PT J AU Hu, SW Nathan, G Kouri, DJ Hoffman, DK Gunaratne, GH AF Hu, SW Nathan, G Kouri, DJ Hoffman, DK Gunaratne, GH TI Statistical characterizations of spatiotemporal patterns generated in the Swift-Hohenberg model SO CHAOS LA English DT Article ID SPIRAL-DEFECT CHAOS; NATURAL PATTERNS; CONVECTIVE FLOW; TRANSITION; DYNAMICS; FLUCTUATIONS; EQUILIBRIUM; STABILITY; EQUATION; STATE AB Two families of statistical measures are used for quantitative characterization of nonequilibrium patterns and their evolution. The first quantifies the disorder in labyrinthine patterns, and captures features like the domain size, defect density, variations in wave number, etc. The second class of characteristics can be used to quantify the disorder in more general nonequilibrium structures, including those observed during domain growth. The presence of distinct stages of relaxation in spatiotemporal dynamics under the Swift-Hohenberg equation is analyzed using both classes of measures. (C) 2005 American Institute of Physics. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Math, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Inst Fundamental Studies, Kandy 2000, Sri Lanka. RP Hu, SW (reprint author), Univ Houston, Dept Chem, Houston, TX 77204 USA. NR 34 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 1054-1500 EI 1089-7682 J9 CHAOS JI Chaos PD DEC PY 2005 VL 15 IS 4 AR 043701 DI 10.1063/1.12046487 PG 5 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 998SI UT WOS:000234339200007 PM 16396591 ER PT J AU Hanshaw, RG Lakshmi, C Lambert, TN Johnson, JR Smith, BD AF Hanshaw, RG Lakshmi, C Lambert, TN Johnson, JR Smith, BD TI Fluorescent detection of apoptotic cells by using zinc coordination complexes with a selective affinity for membrane surfaces enriched with phosphatidylserine SO CHEMBIOCHEM LA English DT Article DE annexin V; apoptosis; fluorescent probes; phosphatidylserine; quantum dots ID ANNEXIN-V; QUANTUM DOTS; EXPOSURE; SYSTEM; BINDING; DEATH AB The appearance of phosphotidylserine on the membrane surface of apoptotic cells (Jurkat, CHO, HeLa) is monitored by using a family of bis(Zn2+-2,2'-dipicolylamine) coordination compounds with appended fluorescein or biotin groups as reporter elements. The phosphatidylserine affinity group is also conjugated directly to a CdSe/CdS quantum dot to produce a probe suitable for prolonged observation without photobleaching. Apoptosis can be detected under a wide variety of conditions, including variations in temperature, incubation time, and binding media. Binding of each probe appears to be restricted to the cell membrane exterior, because no staining of organelles or internal membranes is observed. C1 Univ Notre Dame, Dept Chem & Biochem, Notre Dame, IN 46556 USA. Univ Notre Dame, Walther Ctr Canc Res, Notre Dame, IN 46556 USA. Sandia Natl Labs, Chem Synth & Nanomat, Albuquerque, NM 87185 USA. RP Smith, BD (reprint author), Univ Notre Dame, Dept Chem & Biochem, Notre Dame, IN 46556 USA. EM smith.115@nd.edu NR 29 TC 69 Z9 71 U1 5 U2 19 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1439-4227 J9 CHEMBIOCHEM JI Chembiochem PD DEC PY 2005 VL 6 IS 12 BP 2214 EP 2220 DI 10.1002/cbic.200500149 PG 7 WC Biochemistry & Molecular Biology; Chemistry, Medicinal SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy GA 992XF UT WOS:000233916600016 PM 16276499 ER PT J AU Forsberg, CW AF Forsberg, CW TI The hydrogen economy is coming - The question is where? SO CHEMICAL ENGINEERING PROGRESS LA English DT Article C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Forsberg, CW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM forsbergcw@ornl.gov NR 2 TC 15 Z9 15 U1 0 U2 1 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 DEC PY 2005 VL 101 IS 12 BP 20 EP 22 PG 3 WC Engineering, Chemical SC Engineering GA 993KX UT WOS:000233954100026 ER PT J AU Turesky, RJ LeMaster, D Mcnaughton, L Holland, RD Wu, RW Felton, JS AF Turesky, RJ LeMaster, D Mcnaughton, L Holland, RD Wu, RW Felton, JS TI 2-amino-1,7-dimethylimidazo[4,5-g]quinoxaline (7-MeIgQx): A novel and abundant mutagenic heterocyclic aromatic amine formed in grilled beef. SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Meeting Abstract CT Meeting of the Division of Chemical Toxicology of the American-Chemical-Society held at the 230th National Meeting of the ACS CY AUG 28-SEP 01, 2005 CL Washington, DC SP Amer Chem Soc, Div Chem Toxicol C1 New York State Dept Hlth, Div Environm Dis Prevent, Wadsworth Ctr, Albany, NY 12201 USA. New York State Dept Hlth, Div Biomed Sci, Wadsworth Ctr, Albany, NY 12201 USA. US FDA, NCTR, Div Syst Biol, Rockville, MD 20857 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 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 DEC PY 2005 VL 18 IS 12 MA 58 BP 1979 EP 1979 PG 1 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 004XY UT WOS:000234787200077 ER PT J AU Wilde, EW Brigmon, RL Dunn, DL Heitkamp, MA Dagnan, DC AF Wilde, EW Brigmon, RL Dunn, DL Heitkamp, MA Dagnan, DC TI Phytoextraction of lead from firing range soil by Vetiver grass SO CHEMOSPHERE LA English DT Article DE phytoremediation; Vetiver grass; soil; lead-contamination; EDTA ID PHYTOREMEDIATION; LAND AB Phytoextraction techniques utilizing a sterile strain of Vetiver grass (Vetiveria zizanoides) along with soil amendments were evaluated for removing lead and other elements such as Zn, Cu, and Fe from the soil of a 50-year old active firing range at the Savannah River Site (SRS). Lead-contaminated soil (300-4500 ppm/kg) was collected, dried, placed in pots, fertilized, and used as a medium for growing transplanted Vetiver grass plants in a greenhouse. The uptake of metals by the plants was evaluated in response to various fertilization and pre-harvest treatment schemes. Baseline metal concentrations in the soil of all pots were measured prior to planting and when the plants were harvested. Plants grew better when fertilized with Osmocote (R) fertilizer in comparison to plants fertilized with 10-10-10 (NPK) fertilizer. Application of a chelating agent, EDTA, one week prior to harvest significantly increased the amount of lead that was phytoextracted. Lead concentrations of up to 1390-1450 ppm/kg in tissue samples were detected. Maximum Pb levels were observed in root tissues. The addition of non-lethal doses of a slow-release herbicide in combination with EDTA did not appear to further enhance phytoextraction or the translocation of Pb into shoots. The study indicated that the use of Vetiver grass coupled with the use of chelating soil amendments has considerable potential for use as a remedial strategy for lead-contaminated soils such as those associated with firing ranges. (c) 2005 WSRC. Published by Elsevier Ltd. All rights reserved. C1 Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. US Forest Serv, USDA, Newtown Sq, PA 19073 USA. RP Brigmon, RL (reprint author), Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. EM r03.brigmon@srs.gov NR 18 TC 34 Z9 40 U1 2 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD DEC PY 2005 VL 61 IS 10 BP 1451 EP 1457 DI 10.1016/j.chemosphere.2005.04.059 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA 995CX UT WOS:000234078600008 PM 15964059 ER PT J AU Gallimore, R Jacob, R Kutzbach, J AF Gallimore, R Jacob, R Kutzbach, J TI Coupled atmosphere-ocean-vegetation simulations for modern and mid-Holocene climates: role of extratropical vegetation cover feedbacks SO CLIMATE DYNAMICS LA English DT Article ID LAST GLACIAL MAXIMUM; 9000 YEARS BP; SNOW PARAMETERIZATION; SYNERGISTIC FEEDBACKS; NORTHERN EURASIA; GLOBAL MONSOONS; BOREAL FORESTS; SENSITIVITY; BIOSPHERE; HOLOCENE AB A full global atmosphere-ocean-land vegetation model is used to examine the coupled climate/vegetation changes in the extratropics between modern and mid-Holocene (6,000 year BP) times and to assess the feedback of vegetation cover changes on the climate response. The model produces a relatively realistic natural vegetation cover and a climate sensitivity comparable to that realized in previous studies. The simulated mid-Holocene climate led to an expansion of boreal forest cover into polar tundra areas (mainly due to increased summer/fall warmth) and an expansion of middle latitude grass cover (due to a combination of enhanced temperature seasonality with cold winters and interior drying of the continents). The simulated poleward expansion of boreal forest and middle latitude expansion of grass cover are consistent with previous modeling studies. The feedback effect of expanding boreal forest in polar latitudes induced a significant spring warming and reduced snow cover that partially countered the response produced by the orbitally induced changes in radiative forcing. The expansion of grass cover in middle latitudes worked to reinforce the orbital forcing by contributing a spring cooling, enhanced snow cover, and a delayed soil water input by snow melt. Locally, summer rains tended to increase (decrease) in areas with greatest tree cover increases (decreases); however, for the broad-scale polar and middle latitude domains the climate responses produced by the changes in vegetation are relatively much smaller in summer/fall than found in previous studies. This study highlights the need to develop a more comprehensive strategy for investigating vegetation feedbacks. C1 Univ Wisconsin, Ctr Climat Res, Madison, WI 53706 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Gallimore, R (reprint author), Univ Wisconsin, Ctr Climat Res, 1225 W Dayton St, Madison, WI 53706 USA. EM rggallim@wisc.edu RI Jacob, Robert/D-2580-2011 OI Jacob, Robert/0000-0002-9444-6593 NR 56 TC 38 Z9 38 U1 1 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD DEC PY 2005 VL 25 IS 7-8 BP 755 EP 776 DI 10.1007/s00382-005-0054-z PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 983OA UT WOS:000233240800006 ER PT J AU Barlow, RS Frank, JH Karpetis, AN Chen, JY AF Barlow, RS Frank, JH Karpetis, AN Chen, JY TI Piloted methane/air jet flames: Transport effects and aspects of scalar structure SO COMBUSTION AND FLAME LA English DT Article DE turbulent jet flames; piloted flames; differential diffusion; scalar measurements ID TURBULENT NONPREMIXED FLAMES; RAYLEIGH-LIF MEASUREMENTS; NON-PREMIXED COMBUSTION; NITRIC-OXIDE FORMATION; LARGE-EDDY SIMULATIONS; DIFFUSION FLAMES; DIFFERENTIAL DIFFUSION; MIXTURE-FRACTION; LOCAL EXTINCTION; DISSIPATION RATE AB Previously Unpublished results from multiscalar point measurements in the series of piloted CH4/air jet flames [R.S. Barlow, J.H. Frank, Proc. Combust. Inst. 27 (1998) 1087-1095] are presented and analyzed. The emphasis is on features of the data that reveal the relative importance of molecular diffusion and turbulent transport in these flames. The complete series A-F is considered. This includes laminar, transitional, and turbulent flames spanning a range in Reynolds number front 1100 to 44,800. Results on conditional means of species mass fractions. the differential diffusion parameter, and the state of the water-gas shift reaction all show that there is an evolution in these flames from a scalar structure dominated by molecular diffusion to one dominated by turbulent transport. Long records of 6000 single-point samples at each of several selected locations in flame D are used to quantity the cross-stream (radial) dependence of conditional statistics of measured scalars. The cross-stream dependence of the conditional scalar dissipation is determined from 6000-shot, line-imaging measurements at selected locations. The cross-stream dependence of reactive scalars, which is most significant in the near field of the jet flame, is attributed to radial differences in both convective and local time scales of the flow. Results illustrate some potential limitations of common modeling assumptions when applied to laboratory-scale flames and, thus, provide a more complete context for interpretation of comparisons between experiments and model calculations. (c) 2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77845 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RP Barlow, RS (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. EM barlow@ca.sandia.gov NR 35 TC 78 Z9 80 U1 3 U2 23 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 2005 VL 143 IS 4 BP 433 EP 449 DI 10.1016/j.combustflame.2005.08.017 PG 17 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 995AU UT WOS:000234073100008 ER PT J AU Cabra, R Chen, JY Dibble, RW Karpetis, AN Barlow, RS AF Cabra, R Chen, JY Dibble, RW Karpetis, AN Barlow, RS TI Lifted methane-air jet flames in a vitiated coflow SO COMBUSTION AND FLAME LA English DT Article DE laser spectroscopy; multiscalar measurements; computational modeling; reactions in flames; vitiated flow ID PROBABILITY DENSITY-FUNCTION; FINITE-RATE CHEMISTRY; DIFFUSION FLAME; PDF CALCULATIONS; MIXING MODEL; TEMPERATURE; FLOW; NO; TRANSPORT AB The present vitiated coflow flame consists of a lifted jet flame formed by a fuel jet issuing from a central nozzle into a large coaxial flow of hot combustion products from a lean premixed H-2/air flame. The fuel stream consists of CH4 mixed with air. Detailed multiscalar point measurements from combined Raman-Rayleigh-LIF experiments are obtained for a single base-case condition. The experimental data are presented and then compared to numerical results from probability density function (PDF) calculations incorporating various mixing models. The experimental results reveal broadened bimodal distributions of reactive scalars when the probe volume is in the flame stabilization region. The bimodal distribution is attributed to fluctuation of the instantaneous lifted flame position relative to the probe volume. The PDF calculation using the modified Curl mixing model predicts well several but not all features of the instantaneous temperature and composition distributions, time-averaged scalar profiles, and conditional statistics from the multiscalar experiments. A complementary series of parametric experiments is used to determine the sensitivity of flame liftoff height to Jet velocity, coflow velocity, and coflow temperature. The liftoff height is found to be approximately linearly related to each parameter within the ranges tested, and it is most sensitive to coflow temperature. The PDF model predictions for the corresponding conditions show that the sensitivity of flame liftoff height to jet velocity and coflow temperature is reasonably captured, while the sensitivity to coflow velocity is underpredicted. (c) 2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. Hamilton Sundstrand Power Syst, San Diego, CA 92186 USA. Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77843 USA. RP Chen, JY (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. EM jychen@me.berkeley.edu NR 28 TC 133 Z9 137 U1 3 U2 19 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 2005 VL 143 IS 4 BP 491 EP 506 DI 10.1016/j.combustflame.2005.08.019 PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 995AU UT WOS:000234073100011 ER PT J AU Frank, JH Kaiser, SA Long, MB AF Frank, JH Kaiser, SA Long, MB TI Multiscalar imaging in partially premixed jet flames with argon dilution SO COMBUSTION AND FLAME LA English DT Article DE turbulent flames; imaging diagnostics; mixture fraction; scalar dissipation; Rayleigh scattering; Laser-induced fluorescence ID TURBULENT-DIFFUSION FLAMES; SCALAR DISSIPATION; RAYLEIGH-SCATTERING; HYDROGEN; RAMAN; TEMPERATURE AB Simultaneous imaging of depolarized and polarized Rayleigh scattering combined with OH-LIF and two-photon CO-LIF provides two-dimensional measurements of mixture fraction, temperature, scalar dissipation rate, and the forward reaction rate of the reaction CO + OH = CO2 + H in turbulent partially premixed flames. The concept of the three-scalar technique, for determining the mixture fraction using CO-LIF with depolarized and polarized Rayleigh signals was previously demonstrated in a partially premixed CH4/air jet flame [J.H. Frank, S.A. Kaiser, M.B. Long. Proc. Combust. Inst. 29 (2002) 2687-2694]. In the experiments presented here, we consider a similar jet flame with a fuel-stream mixture that is better suited for the diagnostic technique. The contrast between the depolarized and the polarized Rayleigh signals in the fuel and air streams is improved by partially premixing with an argon/oxygen mixture that has the same oxygen content as air. The substitution of argon, which has a zero depolarization ratio. for the nitrogen in air decreases the depolarized. Rayleigh signal in the fuel stream and thereby increases the contrast between the depolarized and the polarized Rayleigh signals. We present a collection of instantaneous 2-D measurements and examine conditional means of temperature, scalar dissipation, and reaction rates for two downstream locations. The emphasis is on the determination of the scalar dissipation rate from the mixture-fraction images. The axial and radial contributions to scalar dissipation are measured. The effects of noise on the scalar dissipation measurements are determined in a laminar flame, and a method for subtracting the noise contribution to the scalar dissipation rates is demonstrated. (c) 2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. RP Frank, JH (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. EM jhfrank@ca.sandia.gov NR 31 TC 33 Z9 33 U1 0 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 2005 VL 143 IS 4 BP 507 EP 523 DI 10.1016/j.combustflame.2005.08.027 PG 17 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 995AU UT WOS:000234073100012 ER PT J AU Vachal, P Berndt, M Lipnikov, K Shashkov, M AF Vachal, P Berndt, M Lipnikov, K Shashkov, M TI A node reconnection algorithm for mimetic finite difference discretizations of elliptic equations on triangular meshes SO COMMUNICATIONS IN MATHEMATICAL SCIENCES LA English DT Article DE adaptive mesh method; node reconnection; mimetic finite difference; tensor coefficient ID ELEMENT-METHOD; ERROR; OPTIMIZATION AB Most efficient adaptive mesh methods employ a few strategies, including local mesh refinement (h-adaptation), movement of mesh nodes (r-adaptation), and node reconnection (c-adaptation). Despite its simplicity, node reconnection methods are seldom analyzed apart from the other adaptation methods even in applications where severe restrictions are imposed on topological operations with a mesh. However, using only node reconnection the discretization error can be significantly reduced. In this paper, we develop and numerically analyze a new c-adaptation algorithm for mimetic finite difference discretizations of elliptic equations on triangular meshes. Our algorithm is based on a new error indicator for such discretizations, which can also be used for unstructured general polygonal meshes. We demonstrate the efficiency of our new algorithm with numerical examples. C1 Czech Tech Univ, Fac Nucl Sci & Phys Engn, CR-11519 Prague 1, Czech Republic. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Vachal, P (reprint author), Czech Tech Univ, Fac Nucl Sci & Phys Engn, Brehova 7, CR-11519 Prague 1, Czech Republic. EM vachal@galileo.fjfi.cvut.cz; berndt@lanl.gov; lipnikov@lanl.gov; shashkov@lanl.gov RI Vachal, Pavel/G-2131-2011; Berndt, Markus/F-3185-2013 NR 25 TC 1 Z9 1 U1 0 U2 2 PU INT PRESS PI SOMERVILLE PA PO BOX 43502, SOMERVILLE, MA 02143 USA SN 1539-6746 J9 COMMUN MATH SCI JI Commun. Math. Sci. PD DEC PY 2005 VL 3 IS 4 BP 665 EP 680 PG 16 WC Mathematics, Applied SC Mathematics GA 015NJ UT WOS:000235557800011 ER PT J AU Brown, EN White, SR Sottos, NR AF Brown, EN White, SR Sottos, NR TI Retardation and repair of fatigue cracks in a microcapsule toughened epoxy composite - Part 1: Manual infiltration SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE smart materials; polymer-matrix composites; fatigue; failure criterion; self-healing ID GROWTH-BEHAVIOR; FRACTURE-TOUGHNESS; OIL ENVIRONMENTS; GLASS SPHERES; FILLED EPOXY; PROPAGATION; POLYMERS; RESINS; PARTICLES; CLOSURE AB As a first step towards a new crack healing methodology for cyclic loading, this paper examines two promising crack-tip shielding mechanisms during fatigue of a microcapsule toughened epoxy. Artificial crack closure is achieved by injecting precatalyzed monomer into the crack plane to form a polymer wedge at the crack tip. The effect of wedge geometry is also considered, as dictated by crack loading conditions during infiltration. Crack-tip shielding by a polymer wedge formed with the crack held open under the maximum cyclic loading condition (K-max) yields temporary crack arrest and extends the fatigue life by more than 20 times. Hydrodynamic pressure and viscous damping as a mechanism of crack-tip shielding are also investigated by injecting mineral oil into the crack plane. Viscous fluid flow leads to retardation of crack growth independent of initial loading conditions. The success of these mechanisms for retarding fatigue crack growth demonstrates the potential for in situ self-healing of fatigue damage. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Illinois, Dept Theoret & Appl Mech, Urbana, IL 61801 USA. Univ Illinois, Beckman Inst Adv Sci & Technol, Urbana, IL 61801 USA. Univ Illinois, Dept Aerosp Engn, Urbana, IL 61801 USA. RP Brown, EN (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, TA-35,Bldg 455,DCDP 01S,MS-E544, Los Alamos, NM 87545 USA. EM en_brown@lanl.gov OI Brown, Eric/0000-0002-6812-7820 NR 38 TC 130 Z9 141 U1 2 U2 45 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PD DEC PY 2005 VL 65 IS 15-16 SI SI BP 2466 EP 2473 DI 10.1016/j.compscitech.2005.04.020 PG 8 WC Materials Science, Composites SC Materials Science GA 981GR UT WOS:000233076100015 ER PT J AU Webb-Robertson, BJ Oehmen, C Matzke, M AF Webb-Robertson, BJ Oehmen, C Matzke, M TI SVM-BALSA: Remote homology detection based on Bayesian sequence alignment SO COMPUTATIONAL BIOLOGY AND CHEMISTRY LA English DT Article DE support vector machine; Bayesian; sequence alignment; remote homology ID PROTEIN HOMOLOGIES; LOCAL-STRUCTURE; PSI-BLAST; SEARCH; TOOL AB Biopolymer sequence comparison to identify evolutionarily related proteins, or homologs, is one of the most common tasks in bioinformatics. Support vector machines (SVMs) represent a new approach to the problem in which statistical learning theory is employed to classify proteins into families, thus identifying homologous relationships. Current SVM approaches have been shown to outperform iterative profile methods, such as PSI-BLAST, for protein homology classification. In this study, we demonstrate that the utilization of a Bayesian alignment score, which accounts for the uncertainty of all possible alignments, in the SVM construction improves sensitivity compared to the traditional dynamic programming implementation over a benchmark dataset consisting of 54 unique protein families. The SVM-BALSA algorithms returns a higher area under the receiver operating characteristic (ROC) curves for 37 of the 54 families and achieves an improved overall performance curve at a significance level of 0.07. (c) 2005 Elsevier Ltd. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, Richland, WA 99352 USA. EM bj@pnl.gov NR 20 TC 14 Z9 16 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1476-9271 EI 1476-928X J9 COMPUT BIOL CHEM JI Comput. Biol. Chem. PD DEC PY 2005 VL 29 IS 6 BP 440 EP 443 DI 10.1016/j.compbiolchem.2005.09.006 PG 4 WC Biology; Computer Science, Interdisciplinary Applications SC Life Sciences & Biomedicine - Other Topics; Computer Science GA 996HB UT WOS:000234163900006 PM 16290168 ER PT J AU Carjan, N Rizea, M Strottman, D AF Carjan, N Rizea, M Strottman, D TI Improved boundary conditions for the decay of low lying metastable proton states in a time-dependent approach SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE time-dependent Schrodinger equation; transparent boundary conditions; Coulomb functions; decay rate; proton emission ID EQUATIONS AB Artificial boundary conditions have to be imposed on the numerical solution of the time-dependent Schrodinger equation in order to study the decay dynamics of low-lying unbound proton states. This procedure eliminates the reflections of the wave packet at the numerical boundaries. For large numerical grids this happens from the beginning. For smaller grids, these reflections are first reduced and then disappear after few oscillations. At that moment the asymptotic decay rate is reached. Due to inevitable numerical error the asymptotic decay rate depends slightly on the size of the spatial grid and attains a plateau for large grids. The convergence can be considerably improved through a modification of the transparent boundary conditions that accounts for the peculiarity of our problem: nonnegligible Coulomb and centrifugal tails beyond the numerical grid. The impact of the reflections on the time-dependent decay rate can be reduced by replacing, according to the continuity equation, the time derivative of the tunneling probability by the flux at the outer turning point. These improvements allow smaller spatial grids to be used that are also independent of the duration of time evolution. New perspectives for calculating deep tunneling of a proton through a two-dimensional time-dependent barrier are forseen. (C) 2005 Elsevier B.V. All rights reserved. C1 Natl Inst Phys & Nucl Engn Horia Hulubei, Bucharest, Romania. CEN Bordeaux Gradignan, F-33175 Gradignan, France. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RP Rizea, M (reprint author), Natl Inst Phys & Nucl Engn Horia Hulubei, POB MG-6, Bucharest, Romania. EM carjan@in2p3.fr; rizea@theory.nipne.ro; dds@lanl.gov NR 19 TC 11 Z9 11 U1 1 U2 4 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 DEC PY 2005 VL 173 IS 1-2 BP 41 EP 60 DI 10.1016/j.cpc.2005.07.005 PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 989NA UT WOS:000233679600005 ER PT J AU McCall, CR Hill, MA Lillard, RS AF McCall, CR Hill, MA Lillard, RS TI Crystallographic pitting in magnesium single crystals SO CORROSION ENGINEERING SCIENCE AND TECHNOLOGY LA English DT Article DE magnesium; crystallographic pitting; corrosion filaments; single crystal; corrosion; dichromate; hcp metals ID PHOSPHATE CONVERSION COATINGS; PURE MAGNESIUM; CORROSION PROTECTION; SULFATE-SOLUTIONS; ALUMINUM; POTENTIALS; ELECTRON; ALLOYS; ZINC; MG AB The corrosion behaviour of three low index planes of an hcp magnesium (Mg) single crystal was investigated in 10(-2) M NaCl/10(-4) M dichromate solution. The Mg ( 0001) surface exhibited pitting corrosion susceptibility at the open circuit potential. However, the (10 (1) over bar0), and (11 (2) over bar0) surfaces were passive at open circuit and pitting only initiated at potentials slightly anodic to their open circuit potentials. The onset of stable dissolution in the three surfaces was marked by the formation and propagation of corrosion filaments. For the three surfaces investigated, pit shape was non-geometric, however, pit propagation was generally found to occur along preferential crystallographic directions. An analysis of the preferred crystallographic directions is presented. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Mat Corros & Environm Effects Lab, Los Alamos, NM 87545 USA. RP Lillard, RS (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Mat Corros & Environm Effects Lab, MST-6, Los Alamos, NM 87545 USA. EM lillard@lanl.gov NR 27 TC 21 Z9 21 U1 0 U2 10 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 1478-422X J9 CORROS ENG SCI TECHN JI Corros. Eng. Sci. Technol. PD DEC PY 2005 VL 40 IS 4 BP 337 EP 343 DI 10.1179/174327805X66326 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 999LH UT WOS:000234390300014 ER PT J AU Stubicar, M Ocko, M Sarrao, JL Stubicar, N Simek, Z AF Stubicar, M Ocko, M Sarrao, JL Stubicar, N Simek, Z TI Influence of the electronic structure on the plastic properties of the single crystal Yb(x)Y(1-x)InCu(4) and YbAg(y)In(1-y)Cu(4) systems SO CROATICA CHEMICA ACTA LA English DT Article DE influence of electronic structure; Vickers microindentation hardness testing; single crystal of Yb(x)Y(1-x)InCu(4) and YbAg(y)In(1-y)Cu(4) systems with 0 <= x,y <= 1; lattice parameter; electrical resistivity ID THIN-FILMS; MICROHARDNESS CHARACTERIZATION; METALLIC GLASSES; TRANSITION; ALLOYS; YBIN1-XAGXCU4 AB We report the results of Vickers microindentation hardness measurements on two series of the alloy systems: Yb(x)Y(1-x)InCu(4) and YbAg(y)In(1-y)Cu(4), where the parameters x and y vary from 0 to 1. In both systems the microhardness decreases with increasing the concentration parameters x, or y. Almost the same behavior exhibits the lattice parameter of these systems, which governs evolution of the systems from semi-metallic towards more metallic character. In accordance with that, we ascribe the observed concentration dependence of the Vickers microhardness data to the change of the electronic structure of these systems. C1 Univ Zagreb, Fac Sci, HR-10002 Zagreb, Croatia. Univ Zagreb, Inst Phys, HR-10000 Zagreb, Croatia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Stubicar, M (reprint author), Univ Zagreb, Fac Sci, Bijenicka C 32, HR-10002 Zagreb, Croatia. EM stubicar@sirius.phy.hr NR 25 TC 1 Z9 1 U1 0 U2 3 PU CROATIAN CHEMICAL SOC PI ZAGREB PA MARULICEV TRG 19/II, 41001 ZAGREB, CROATIA SN 0011-1643 J9 CROAT CHEM ACTA JI Croat. Chem. Acta PD DEC PY 2005 VL 78 IS 4 BP 627 EP 632 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 002AX UT WOS:000234584900019 ER PT J AU Kistenev, E AF Kistenev, E CA PHENIX Forward Calorimeter Collabo TI Silicon-tungsten calorimeter for the forward direction in the PHENIX experiment at RHIC SO CZECHOSLOVAK JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 8th Workshop on Electric Fields, Structures and Relaxation in Edge Plasmas CY JUL 03-04, 2005 CL Tarragona, SPAIN SP Acad Sci Czech Republic, Inst Plasma Phys DE calorimeter; forward spectrometer; mechanical design; analog and digital readout; electronics; triggering AB The PHENIX detector at RHIC has been designed to study hadronic and leptonic signatures of the Quark Gluon Plasma in heavy ion collisions and spin dependent structure functions in polarized proton collisions. The baseline detector measures muons in two muon spectrometers located forward and backward of mid-rapidity, and measures hadrons, electrons, and photons in two central spectrometer arms, each of which covers 90 degrees in azimuth and 0.35 units of rapidity. Further progress requires extending rapidity coverage for hadronic and electromagnetic signatures by upgrading the functionality of the PHENIX muon spectrometers to include photon and jet measurement capabilities. Tungsten calorimeters with silicon pixel readout and fine transverse and longitudinal segmentation are proposed to attain this goal. The use of such a design provides the highest density and finest granularity possible in a calorimeter. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kistenev, E (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU INST PHYSICS ACAD SCI CZECH REPUBLIC PI PRAGUE PA NA SLOVANCE 2, PRAGUE 182 21, CZECH REPUBLIC SN 0011-4626 J9 CZECH J PHYS JI Czech. J. Phys. PD DEC PY 2005 VL 55 IS 12 BP 1659 EP 1669 DI 10.1007/s10582-006-0056-z PG 11 WC Physics, Multidisciplinary SC Physics GA 004GE UT WOS:000234739200015 ER PT J AU Istrate, G AF Istrate, G TI Threshold properties of random boolean constraint satisfaction problems SO DISCRETE APPLIED MATHEMATICS LA English DT Article; Proceedings Paper CT Workshop on Typical Case Complexity and Phase Transitions CY JUN 21, 2003 CL Ottawa, CANADA SP LICS, NSERC, MITACS DE random constraint satisfaction problems; sharp thresholds ID PHASE-TRANSITIONS AB We study threshold properties of random constraint satisfaction problems under a probabilistic model due to Molloy [Models for random constraint satisfaction problems, in: Proceedings of the 32nd ACM Symposium on Theory of Computing, 2002]. We give a sufficient condition for the existence of a sharp threshold. In the boolean case, it gives an independent proof for the more difficult half of a classification result conjectured by Creignou and Daude [Generalized satisfiability problems: minimal elements and phase transitions. Theor. Comput. Sci. 302(1-3) (2003) 417-430], proved in a restricted case by the same authors [Combinatorial sharpness criterion and phase transition classification for random CSPs, Inform. Comput. 190(2) (2004) 220-238], and established by them [Coarse and sharp thresholds for random generalized satisfiability problems, in: M. Drmota, P. Flajolet, D. Gardy, B. Gittenberger (Eds.), Mathematics and Computer Science III: Algorithms, Trees, Combinatorics and Probabilities, Birkhauser, Basel, September 2004, pp. 507-517] while this paper was in the refereeing process. (c) 2005 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, CCS Basic & Appl Simulat Sci 5, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, CCS Basic & Appl Simulat Sci 5, Mail Stop M997, Los Alamos, NM 87545 USA. EM istrate@lanl.gov NR 13 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-218X EI 1872-6771 J9 DISCRETE APPL MATH JI Discret Appl. Math. PD DEC 1 PY 2005 VL 153 IS 1-3 BP 141 EP 152 DI 10.1016/j.dam.2005.05.010 PG 12 WC Mathematics, Applied SC Mathematics GA 993MJ UT WOS:000233957900009 ER PT J AU Travis, BJ Schubert, G AF Travis, BJ Schubert, G TI Hydrothermal convection in carbonaceous chondrite parent bodies SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE carbonaceous chondrite meteorites; hydrothermal convection ID POROUS-MEDIUM; TRANSPORT-PROPERTIES; NATURAL-CONVECTION; LIQUID WATER; ICE; HEAT; MARS AB Numerical simulations of the thermal evolution of carbonaceous chondrite parent bodies indicate a period of several million years during which convective motion of water could occur. The present Study considers variations of permeability, radiogenic heating, and body radius. The model accounts for the radial variation of gravity within the body, melting, of ice, freezing of liquid water, and variable water properties and incorporates a realistic equation of State for water Some regions of a parent body, experience no pore water flow while other regions experience hundreds of pore volumes of liquid water flow. The spatia heterogeneity in pore water flow reflects the convective pattern in the body. Hydrothermal alteration of minerals inside the parent body will accordingly vary greatly with location in the body, and one parent body could be the source of chemically diversity meteorites. (C) 2005 Elsevier B.V. All rights reserved. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Schubert, G (reprint author), Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. EM bjtravis@lanl.gov; schubert@ucla.edu NR 24 TC 41 Z9 42 U1 0 U2 2 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 DEC 1 PY 2005 VL 240 IS 2 BP 234 EP 250 DI 10.1016/j.epsl.2005.09.008 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 000NX UT WOS:000234470100004 ER PT J AU Jenniskens, P Wercinski, P Olejniczak, J Raiche, G Kontinos, D Allen, G Desai, PN Revelle, D Hatton, J Baker, RL Russell, RW Taylor, M Rietmeijer, F AF Jenniskens, P Wercinski, P Olejniczak, J Raiche, G Kontinos, D Allen, G Desai, PN Revelle, D Hatton, J Baker, RL Russell, RW Taylor, M Rietmeijer, F TI Preparing for hyperseed MAC: An observing campaign to monitor the entry of the Genesis Sample Return Capsule SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT Meteoroids 2004 Conference CY AUG 16-20, 2004 CL Univ Western Ontario, London, ENGLAND SP Gerenc Seguridad Ind & Protecc Ambiental RMNE, PEMEX Explorac Producc HO Univ Western Ontario DE astrobiology; fireball; Genesis; meteor; reentry; sample return capsule; thermal protection system AB The return of the Genesis Sample Return Capsule ( SRC) from the Earth's L1 point on September 8, 2004, represents the first opportunity since the Apollo era to study the atmospheric entry of a meter-sized body at or above the Earth's escape speed. Until now, reentry heating models are based on only one successful reentry with an instrumented vehicle at higher than escape speed, the 22 May 1965 NASA "FIRE 2'' experiment. In preparation of an instrumented airborne and ground-based observing campaign, we examined the expected bolide radiation for the reentry of the Genesis SRC. We find that the expected emission spectrum consists mostly of blackbody emission from the SRC surface ( T similar to 2630 K@ peak heating), slightly skewed in shape because of a range of surface temperatures. At high enough spectral resolution, shock emission from nitrogen and oxygen atoms, as well as the first positive and first negative bands of N-2(+), will stand out above this continuum. Carbon atom lines and the 389-nm CN band emission may also be detected, as well as the mid-IR 4.6-mu m CO band. The ablation rate can be studied from the signature of trace sodium in the heat shield material, calibrated by the total amount of matter lost from the recovered shield. A pristine collection of the heat shield would also permit the sampling of products of ablation. C1 SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. ELORET Inst, Sunnyvale, CA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Aerosp Corp, El Segundo, CA USA. Utah State Univ, Logan, UT 84322 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Jenniskens, P (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA. EM pjenniskens@mail.arc.nasa.gov NR 12 TC 12 Z9 12 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD DEC PY 2005 VL 95 IS 1-4 BP 339 EP 360 DI 10.1007/s11038-005-9021-2 PG 22 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 022VF UT WOS:000236083500035 ER PT J AU Revelle, DO AF Revelle, DO TI Recent advances in bolide entry modeling: A bolide potpourri SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT Meteoroids 2004 Conference CY AUG 16-20, 2004 CL Univ Western Ontario, London, ENGLAND HO Univ Western Ontario ID LARGE METEOROIDS; EARTHS ATMOSPHERE; ABLATION; INFRASOUND; RADIATION; DYNAMICS; IMPACTS; FRAGMENTATION; WAVES AB In this paper, we will review recent research on numerous aspects of bolide entry into a planetary atmosphere, including such topics as the entry dynamics, energetics, ablation, deceleration, fragmentation, luminosity, mechanical wave generation processes, a total (panchromatic) power budget including differential and integral efficiencies versus time, etc. Fragmentation, triggered by stagnation pressures exceeding the bolide breaking strength, has been subsequently included in either a collective or non-collective wake behavior limit. We have also utilized the differential panchromatic luminous efficiency of ReVelle and Ceplecha (2002) to compute bolide luminosity. In addition we also introduce the concept of the differential and integral acoustic/infrasonic efficiency and generalized it to the case of mechanical wave efficiency including internal atmospheric gravity waves generated during entry. Unlike the other efficiencies which are assumed to be a constant multiple of the luminous efficiency, the acoustic efficiency is calculated independently using a "first principles" approach. All of these topics have been pursued using either a homogeneous or a porous meteoroid model with great success. As a direct result, porosity seems to be a rather good possibility for explaining anomalous meteoroid behavior in the atmosphere. C1 Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Revelle, DO (reprint author), Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. EM revelle@lanl.gov NR 35 TC 7 Z9 7 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD DEC PY 2005 VL 95 IS 1-4 BP 441 EP 476 DI 10.1007/s11038-005-9064-4 PG 36 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 022VF UT WOS:000236083500044 ER PT J AU Edwards, WN Brown, PG Revelle, DO AF Edwards, WN Brown, PG Revelle, DO TI Bolide energy estimates from infrasonic measurements SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT Meteoroids 2004 Conference CY AUG 16-20, 2004 CL Univ Western Ontario, London, ENGLAND HO Univ Western Ontario ID MORAVKA METEORITE FALL; ORBIT; ATMOSPHERE; EXPLOSION; DYNAMICS; MODEL AB The acoustic amplitude-yield relationships, including formal errors, for a population of energetic (> 0.05 kt) and well-observed bolide events have been investigated. Using various infrasonic signal measurements as a function of range, these data have been calibrated against optical yield estimates from satellite measurements. Correction for the presence of stratospheric winds has also been applied to the observations and is found to be small, suggesting that either scatter is dominated by other variations amongst the fireball population such as differing burst altitudes and greater or lesser amounts of fragmentation or the magnitude of the variability in the stratospheric winds, which can be comparable to or even exceed the strength of the winds themselves. Comparison to similar point source, ground-level nuclear and high explosive airwave data shows that bolide infrasound is consistently lower in amplitude. This downward shift relative to nuclear and HE data is interpreted as due in part to increased weak non-linearity during signal propagation from higher altitudes. This is a likely explanation, since mean estimates of the altitude of maximum ene0rgy deposition along the bolide trajectory was found to be between 20 and 30 km altitude for this fireball population. C1 Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada. Univ Western Ontario, Dept Phys & Astron, Canada Res Chair Meteor Sci, London, ON N6A 3K7, Canada. Los Alamos Natl Lab, Atmospher Climate & Environm Dynam Metoerol Model, Los Alamos, NM 87545 USA. RP Edwards, WN (reprint author), Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada. NR 21 TC 4 Z9 4 U1 1 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD DEC PY 2005 VL 95 IS 1-4 BP 501 EP 512 DI 10.1007/s11038-005-2244-4 PG 12 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 022VF UT WOS:000236083500047 ER PT J AU Davis, GA Friedmann, SJ AF Davis, GA Friedmann, SJ TI Large-scale gravity sliding in the Miocene Shadow Valley Supradetachment Basin, Eastern Mojave Desert, California SO EARTH-SCIENCE REVIEWS LA English DT Article DE slide blocks; gravity tectonics; Shadow Valley; Kingston Wash; Mojave Desert ID ROCK-AVALANCHE DEPOSITS; DETACHMENT FAULT SYSTEM; SOUTHEASTERN CALIFORNIA; DEFORMATION; EVOLUTION; THRUST; RANGE AB The Miocene Shadow Valley basin in the eastern Mojave Desert of California developed above the active west-dipping Kingston Range-Halloran Hills extensional detachment fault system between 13.5 and ca. 7 mybp. Although mass-wasting processes are common phenomena in supradetachment basins, the Shadow Valley basin is an exceptional locale for the study of such processes, especially rock-avalanches and gravity sliding. A score of megabreccias, interpreted as rock-avalanche deposits, and half that number of very large (> 1 km(2), up to 200 in thick), internally intact gravity-driven slide sheets are interbedded with various sedimentary facies. The slide sheets, variably composed of Proterozoic crystalline rocks and Proterozoic, Paleozoic, and Tertiary sedimentary strata, moved across both depositional and erosional surfaces in the basin. Although the majority consist of Paleozoic carbonate rocks, the largest slide sheet, the Eastern Star crystalline allochthon, contains Proterozoic greisses and their sedimentary cover and is now preserved as klippen atop Miocene lacustrine and alluvial fan deposits over an area > 40 km(2). Estimates of slide sheet runouts into the basin from higher eastern and northern source terranes range from approximately a few km to > 10 km; in most cases the exact provenances of the slide blocks are not known. The basal contacts of Shadow Valley slide sheets are characteristically knife sharp, show few signs of lithologic mixing of upper- and lower-plate rocks, and locally exhibit slickensided and striated, planar fault-like bases. Pronounced folding of overridden Miocene lacustrine and fan deposits beneath the Eastern Star allochthon extends to depths up to 40 m at widely scattered localities. We conclude that this slow moving slide sheet encountered isolated topographic asperities (hills) and that stress transfer across the basal slide surface produced folding of footwall strata. Synkinematic gypsum veins in footwall playa sediments, with fibers up to 12 cm long, have trends and shear senses compatible with the direction and sense of displacement of the overriding crystalline allochthon. The undisturbed veins, which closely parallel the base of the slide sheet, attest to high fluid presence and pressure in the playa sediments-factors facilitating allochthon movement across them. The long length of the fibers, indicative of a protracted dilational process, is incompatible with a catastrophic rate of emplacement. We believe that the only explanation for slow displacement of this allochthon and other gravity driven slide sheets across the landscape is that they formed as slumps on high, steep bedrock slopes and that their elevated heads drove their toes across lower fan and playa deposits. Initial detachments from bedrock sources were facilitated by pre-existing structural and stratigraphic anisotropies. Detachment of the Eastern Star allochthon from the bedrock of Shadow Mountain likely occurred by inversion along the playaward dip of a preexisting Mesozoic thrust fault within Proterozoic rock units. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. RP Davis, GA (reprint author), Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. EM gdavis@usc.edu NR 46 TC 7 Z9 8 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-8252 J9 EARTH-SCI REV JI Earth-Sci. Rev. PD DEC PY 2005 VL 73 IS 1-4 BP 149 EP 176 DI 10.1016/j.earscirev.2005.04.008 PG 28 WC Geosciences, Multidisciplinary SC Geology GA 000PD UT WOS:000234473400012 ER PT J AU Dale, V Archer, S Chang, M Ojima, D AF Dale, V Archer, S Chang, M Ojima, D TI Ecological impacts and mitigation strategies for rural land management SO ECOLOGICAL APPLICATIONS LA English DT Article; Proceedings Paper CT 87th Annual Meeting of the Ecological-Society-of-America CY AUG, 2002 CL Tucson, AZ SP Ecol Soc Amer DE aggressive species; biomass; carbon sequestration; cumulative impacts; disturbance; invasion; land cover; land use; legacy; pollution ID UNITED-STATES; SOIL-EROSION; CLIMATE-CHANGE; BIOGENIC HYDROCARBONS; BIOLOGICAL INVASIONS; CARBON SEQUESTRATION; VARIABILITY CONCEPTS; NITROGEN DEPOSITION; EMISSION INVENTORY; TEMPERATE SAVANNA AB Land-use change and land-management practices affect a variety of ecological processes. Land-use impacts. on ecological processes include local extirpations, introductions of new species, changes in land-cover extent, changes in juxtaposition of land-cover types, changes to disturbance regimes, changes in vegetation structure and composition, and effects on air, water, And light quality, and noise pollution. Effects of land-use changes on ecological processes are, discussed-with special reference to changes in rural environments. Our premise is that better understanding of ecological processes improves land management. Mitigation strategies are presented with respect to management of initial ecological conditions, of the changes themselves, and of the altered system. The paper focuses on proactive environmental management efforts and identifies key research issues as (1) quantifying land-use legacies, (2) determining conditions under which land use modifies impacts of other stressors, (3) identifying conditions under which deleterious impacts can be avoided, (4) understanding cumulative impacts of land-use change, (5) improving our understanding of how land use alters resistance or susceptibility to invasion and impacts of pollutants, (6) crafting socioeconomically reasonable incentives for restoring or reducing effects of land-use practices, and (7) :accelerating the integration of social and ecological sciences. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Arizona, Sch Nat Resources, Tucson, AZ 85721 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. RP Dale, V (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. EM dalevh@ornl.gov RI Dale, Virginia/B-6023-2009; Ojima, Dennis/C-5272-2016 NR 166 TC 38 Z9 38 U1 5 U2 22 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD DEC PY 2005 VL 15 IS 6 BP 1879 EP 1892 DI 10.1890/03-5330 PG 14 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 992BL UT WOS:000233858900004 ER PT J AU Theobald, DM Spies, T Kline, J Maxwell, B Hobbs, NT Dale, VH AF Theobald, DM Spies, T Kline, J Maxwell, B Hobbs, NT Dale, VH TI Ecological support for rural land-use planning SO ECOLOGICAL APPLICATIONS LA English DT Article; Proceedings Paper CT 87th Annual Meeting of the Ecological-Society-of-America CY AUG, 2002 CL Tucson, AZ SP Ecol Soc Amer DE environmental indicators; exurban development; rural land-use planning ID SMALL DECISIONS; PRIVATE LANDS; BIODIVERSITY; CONSERVATION; COVER; OREGON; ALTERNATIVES; INFORMATION; ECOSYSTEMS; WISCONSIN AB How can ecologists be more effective in supporting ecologically informed rural land-use. planning and policy? Improved decision making about rural lands requires careful consideration of how ecological information and analyses can inform specific planning and policy-needs. We provide a brief overview of rural land-use planning, including recently developed approaches to conservation. Effective participation in land-use planning requires ecologists to understand trade-offs-for example, the need to balance a land owner's desire for a fair and predictable process with the "learn as you go" approach,of adaptive management-and the importance of integrating local knowledge with landscape-level information. Four primary challenges require attention from ecologists to improve rural land-use planning. First is the mismatch between the spatial and temporal scales in which, ecological processes occur and the scales and tempos of land-use. planning. Second, ecologists must engage in interdisciplinary research to critically evaluate and determine how, if, and when ecological information influences: rural land-use outcomes. Third, a comprehensive land-use framework is needed. to better place ecological studies within a broader landscape context. Finally, ecologists have a key role in developing environmental indicators that directly inform local, rural land-use planning efforts. C1 Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. Colorado State Univ, Dept Nat Resource Recreat & Tourism, Ft Collins, CO 80523 USA. USDA, Forest Serv Pacific NW Res Stn, Corvallis, OR 97331 USA. Montana State Univ, Dept Land Resources & Environm Sci, Bozeman, MT 59717 USA. Colorado State Univ, Dept Fishery & Wildlife Biol, Ft Collins, CO 80523 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Theobald, DM (reprint author), Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. EM davet@nrel.colostate.edu RI Dale, Virginia/B-6023-2009; Hobbs, Tom/C-5263-2016 NR 57 TC 50 Z9 51 U1 1 U2 13 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 DEC PY 2005 VL 15 IS 6 BP 1906 EP 1914 DI 10.1890/03-5331 PG 9 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 992BL UT WOS:000233858900006 ER PT J AU Berezovskaya, F Karev, G Snell, TW AF Berezovskaya, F Karev, G Snell, TW TI Modeling the dynamics of natural rotifer populations: Phase-parametric analysis SO ECOLOGICAL COMPLEXITY LA English DT Article DE dynamical model; rotifer populations; phase-parameter portraits; dynamics of natural populations; population persistence; extinction ID TIME-SERIES; CHAOS; INTERVAL; MAPS AB A model of the dynamics of natural rotifer populations is described as a discrete non-linear map depending on three parameters; which reflect characteristics of the population and environment. Model dynamics and their change by variation of these parameters were investigated by methods of bifurcation theory. A phase-parametric portrait of the model was constructed and domains of population persistence (stable equilibrium, periodic and a-periodic oscillations of population size) as well as population extinction were identified and investigated. The criteria for population persistence and approaches to determining critical parameter values are described. The results identify parameter values that lead to population extinction under various environmental conditions. They further illustrate that the likelihood of extinction can be substantially increased by small changes in environmental quality, which shifts Populations into new dynamical regimes. (c) 2005 Elsevier B.V. All rights reserved. C1 Howard Univ, Dept Math, Washington, DC 20059 USA. Georgia Inst Technol, Sch Biol, Atlanta, GA 30332 USA. Oak Ridge Inst Sci & Educ, NIH, Bethesda, MD 20894 USA. RP Berezovskaya, F (reprint author), Howard Univ, Dept Math, Washington, DC 20059 USA. EM fsberezo@hotmail.com NR 21 TC 6 Z9 8 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1476-945X J9 ECOL COMPLEX JI Ecol. Complex. PD DEC PY 2005 VL 2 IS 4 BP 395 EP 409 DI 10.1016/j.ecocom.2005.04.008 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 987NF UT WOS:000233523900004 ER PT J AU Daszak, P Scott, DE Kilpatrick, AM Faggioni, C Gibbons, JW Porter, D AF Daszak, P Scott, DE Kilpatrick, AM Faggioni, C Gibbons, JW Porter, D TI Amphibian population declines at savannah river site are linked to climate, not chytridiomycosis SO ECOLOGY LA English DT Article DE amphibian population declines; Batrachochytrium dendrobatidis; chytridiomycosis; climate change; disease ecology; host-parasite ecology; hydroperiod; Savannah River ID BATRACHOCHYTRIUM-DENDROBATIDIS; RANA-CATESBEIANA; EMERGING PATHOGEN; CHYTRID FUNGUS; DISEASE; FROGS; MORTALITY; DENSITY AB Amphibian populations at the Savannah River Site (SRS), South Carolina, USA, have been censused consistently for 35 years, and this Provides a time series to examine the causes Of Population fluctuations. We examined archived museum specimens of 15 anuran species collected at wetlands on the SRS for the presence of the causative agent (Batrachochytrium dendrobatidis) of chytridiomycosis, an emerging disease associated with population declines elsewhere. Infections were present in three out of 137 (2.18%) individuals; the pathogen was detected in two Rana catesbeiana and a single Rana sphenocephala, all collected between 1978 and 1981. Lesions were not consistent with the later stages of fatal chytridiomycosis. Analysis of population trajectories of nine amphibian species over 26 years at SRS showed that four species declined significantly over this period, including R. sphenocephala. However, we demonstrate that these declines are more likely caused by an increase in the number of years with insufficient rainfall and a shortened hydroperiod at the breeding site than by chytrid epidemics. This pattern appears to be linked to a drying trend at SRS through the 1990s, although it is unclear whether this was caused by climate change. This study demonstrates that the presence of B. dendrobatidis in amphibian communities where some species are declining does not always implicate chytrids as a cause of the decline. Like many other emerging pathogens, the outcome of infection can vary among individuals and populations, depending on life history traits, environmental conditions, and virulence factors of the pathogen. Our report also demonstrates the usefulness of archived museum specimens and long-term population monitoring in studying the host-parasite ecology of emerging diseases. C1 Consortium Conservat Med, Beijing 100011, Peoples R China. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Coll Vet Med, Athens, GA 30602 USA. Univ Georgia, Dept Plant Biol, Athens, GA 30602 USA. RP Daszak, P (reprint author), Consortium Conservat Med, 460 W 34th St,17th Floor, Beijing 100011, Peoples R China. EM daszak@conservationmedicine.org NR 31 TC 99 Z9 115 U1 2 U2 53 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD DEC PY 2005 VL 86 IS 12 BP 3232 EP 3237 DI 10.1890/05-0598 PG 6 WC Ecology SC Environmental Sciences & Ecology GA 994YI UT WOS:000234066700012 ER PT J AU Kerlau, M Reimer, JA Cairns, EJ AF Kerlau, M Reimer, JA Cairns, EJ TI Investigation of particle isolation in Li-ion battery electrodes using Li-7 NMR spectroscopy SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE Li-ion battery; LiNi0.8Co0.15Al0.05O2; Li-7 MAS NMR; particle isolation ID RECHARGEABLE BATTERIES; CATHODE MATERIALS; LICOO2; CELLS AB Li-7 MAS NMR spectroscopy was used to study the failure mechanisms of LiNi0.8Co0.15Al0.05O2 electrodes in Li-ion cells. Three sets of electrodes with different degrees of power fade (0%, 9%, and 23%) were Studied. The three electrodes were charged to various states of charge (0%, 40%, 60%, 80% and 100%) in pouch cells which were Subsequently disassembled for NMR analysis. The lithium NMR shifts of the positive electrodes in the different states of charge were investigated. The results indicate that NMR spectroscopy can be used to probe particle isolation in these electrodes. Particle isolation is responsible for the capacity and power fades since some of the active material particles are disconnected from the matrix. This Study also clearly showed the loss of electrochemically active lithium as the power fade increased. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kerlau, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, EETD 1,Cyclotron Rd, Berkeley, CA 94720 USA. EM mkerlau@lbl.gov RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 18 TC 12 Z9 12 U1 2 U2 19 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1388-2481 EI 1873-1902 J9 ELECTROCHEM COMMUN JI Electrochem. Commun. PD DEC PY 2005 VL 7 IS 12 BP 1249 EP 1251 DI 10.1016/j.elecom.2005.09.003 PG 3 WC Electrochemistry SC Electrochemistry GA 990CJ UT WOS:000233720500013 ER PT J AU Liu, GD Riechers, SL Timchalk, C Lin, YH AF Liu, GD Riechers, SL Timchalk, C Lin, YH TI Sequential injection/electrochemical immunoassay for quantifying the pesticide metabolite 3,5,6-trichloro-2-pyridinol SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE sequential injection; immunoassay; biomarker ID MASS-SPECTROMETRY; GENERAL-POPULATION; RAT PLASMA; CHLORPYRIFOS; INJECTION; URINE; CHROMATOGRAPHY; EXPOSURE; SAMPLES; SYSTEM AB An automated and sensitive sequential injection electrochemical immunoassay was developed to monitor a potential insecticide biomarker, 3,5,6-trichloro-2-pyridinol. The current method involved a sequential injection analysis (SIA) system equipped with a thin-layer electrochemical flow cell and permanent magnet, which was used to fix 3,5,6-trichloro-2-pyridinol (TCP) antibody coated magnetic beads (TCP-Ab-MBs) in the reaction zone. After competitive immunoreactions among TCP-Ab-MBs, TCP analyte, and horseradish peroxidase (HRP) labeled TCP, a 3,3',5,5'-tetramethylbenzidine dihydrochloride and hydrogen peroxide (TMB-H2O2) substrate solution was injected to produce an electroactive enzymatic product. The activity of HRP tracers was monitored by a square wave voltammetric scanning electroactive enzymatic product in the thin-layer flow cell. The voltammetric characteristics of the Substrate and the enzymatic product were investigated under batch conditions, and the parameters of the immunoassay were optimized in the SIA system. Under the optimal conditions, the system Was used to measure as low as 6 ng L-1(ppt) TCP, which is around 50-fold lower than the value indicated by the manufacturer of the TCP RaPID Assay (R) kit (0.25 mu g/L, colorimetric detection). The performance of the developed immunoassay system was successfully evaluated on tap water and river water samples spiked with TCP. This technique could be readily used for detecting other environmental contaminants by developing specific antibodies against contaminants and is expected to open new opportunities For environmental and biological monitoring. (c) 2005 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Lin, YH (reprint author), Pacific NW Natl Lab, 902 Battele Blvd, Richland, WA 99352 USA. EM yuehe.lin@pnl.gov RI Lin, Yuehe/D-9762-2011; OI Lin, Yuehe/0000-0003-3791-7587; Riechers, Shawn/0000-0002-5713-5534 NR 27 TC 20 Z9 20 U1 1 U2 12 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 DEC PY 2005 VL 7 IS 12 BP 1463 EP 1470 DI 10.1016/j.elecom.2005.10.005 PG 8 WC Electrochemistry SC Electrochemistry GA 990CJ UT WOS:000233720500050 ER PT J AU Zhu, WH Venable, J Giometti, CS Khare, T Tollaksen, S Ahrendt, AJ Yates, JR AF Zhu, WH Venable, J Giometti, CS Khare, T Tollaksen, S Ahrendt, AJ Yates, JR TI Large-scale mu LC-MS/MS for silver- and Coomassie blue-stained polyacrylamide gels SO ELECTROPHORESIS LA English DT Article DE automation; Coomassie Blue staining; mu LC-MS/MS; mass spectrometry; protein identification; SEQUEST; silver staining; two-dimensional gel electrophoresis ID TANDEM MASS-SPECTROMETRY; 2-DIMENSIONAL ELECTROPHORESIS; PROTEIN IDENTIFICATIONS; SHOTGUN PROTEOMICS; SAMPLE PREPARATION; QUANTITATION; MECHANISM; PEPTIDES; COLUMN; LEVEL AB 2-DE combined with LC-MS/MS has become a routine, reliable protein separation and identification technology for proteome analysis. The demand for large-scale protein identifications after 2-DE separation requires a sensitive and high-throughput LC-MS/MS method. In this report, a simple, splitless, fully automated capillary LC-MS/MS system was described for the large-scale identification of proteins from gels stained with either silver or CBB. The gel samples were digested and peptides were extracted using an in-gel digestion workstation. The peptides were automatically introduced into a capillary column by an autosampler connected to an HPLC pump. A nanoLC pump was then used to deliver the gradient and elute the peptides from the capillary column directly into an LCQ IT mass spectrometer. Neither a peptide trapping setting nor a flow split is needed in this simple setup. The collected MS/MS spectra were then automatically searched by SEQUEST, and filtered and organized by DTASelect. Hundreds of silver-stained or CBB-stained Shewanella oneidensis, Geobacter sulfurreducens, and Geobacter metallireducens proteins separated by denaturing or nondenaturing 2-DE were digested and routinely analyzed using this fully automated mu LC-MS/MS system. High peptide hits and sequence coverage were achieved for most CBB-stained gel spots. About 75% of the spots were found to contain multiple proteins. Although silver staining is not commonly thought to be optimal for MS analysis, protein identifications were successfully obtained from silver-stained 2-DE spots detected using methods with and without formaldehyde for protein fixation. C1 Scripps Res Inst, Dept Cell Biol, La Jolla, CA 92037 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Yates, JR (reprint author), Scripps Res Inst, Dept Cell Biol, 10550 N Torrey Pines Rd, La Jolla, CA 92037 USA. EM jyates@scripps.edu FU NCRR NIH HHS [P41 RR11823-09] NR 36 TC 8 Z9 8 U1 1 U2 8 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD DEC PY 2005 VL 26 IS 23 BP 4495 EP 4507 DI 10.1002/elps.200500093 PG 13 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 994YJ UT WOS:000234066800014 PM 16315175 ER PT J AU Hewlett, JG AF Hewlett, JG TI De-regulated electric power markets and operating nuclear power plants: the case of British energy SO ENERGY POLICY LA English DT Article DE nuclear power; electricity power restructuring; nuclear waste AB One issue addressed in almost all electric power restructuring/de-regulation plans in both the United States (US) and the United Kingdom (UK) was the recovery of operating nuclear power plant's spent fuel disposal costs and the expenditures to decommission the units when they are retired. Prior to restructuring, in theory at least, in both countries, electricity consumers were paying for the back end costs from operating nuclear power plants. Moreover, in virtually all cases in the US, states included special provisions to insure that consumers would continue to do so after power markets were de-regulated. When power markets in the UK were initially restructured/de-regulated and nuclear power privatized, the shareholders of British Energy (BE) were initially responsible for these costs. However, after electricity prices fell and BE collapsed, the British government shifted many of the costs to future taxpayers, as much as a century forward. If this was not done, the book value of BE's equity would have been about -3.5 billion pounds. That is, BE's liabilities would have been about -3.5 billion pounds greater than their assets. It is difficult to see how BE could remain viable under such circumstances. (c) 2004 Elsevier Ltd. All rights reserved. C1 US DOE, Energy Informat Adm, Washington, DC 20585 USA. RP Hewlett, JG (reprint author), 2711 Ordway St,NW 105, Washington, DC 20008 USA. EM James.Hewlett@eia.doe.gov NR 8 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD DEC PY 2005 VL 33 IS 18 BP 2293 EP 2297 DI 10.1016/j.enpol.2004.05.006 PG 5 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 966BA UT WOS:000231993400001 ER PT J AU Budnitz, RJ Cornell, CA Morris, JA AF Budnitz, RJ Cornell, CA Morris, JA TI Comment on J.U. Klugel's "Problems in the application of the SSHAC probability method for assessing earthquake hazards at Swiss nuclear power plants," in Engineering Geology, vol. 78, pp. 285-307 SO ENGINEERING GEOLOGY LA English DT Editorial Material C1 Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94551 USA. Stanford Univ, Terman Engn Ctr, Dept Civil & Environm Engn, Stanford, CA 94305 USA. VMN Grp LLC, Los Altos Hills, CA 94022 USA. RP Budnitz, RJ (reprint author), Lawrence Livermore Natl Lab, Energy & Environm Directorate, POB 808,Mail Stop L-632, Livermore, CA 94551 USA. EM budnitz1@LLNL.gov; cornell@stanford.edu; pete@vmngroup.com NR 3 TC 6 Z9 6 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0013-7952 J9 ENG GEOL JI Eng. Geol. PD DEC PY 2005 VL 82 IS 1 BP 76 EP 78 DI 10.1016/j.enggeo.2005.09.009 PG 3 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA 997KG UT WOS:000234243500010 ER PT J AU Tsuji, JS Van Kerkhove, MD Kaetzel, RS Scrafford, CG Mink, PJ Barraj, LM Crecelius, EA Goodman, M AF Tsuji, JS Van Kerkhove, MD Kaetzel, RS Scrafford, CG Mink, PJ Barraj, LM Crecelius, EA Goodman, M TI Evaluation of exposure to arsenic in residential soil SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE arsenic; biomonitoring; exposure; soil; urine ID COPPER SMELTER; US POPULATION; CHILDREN; WATER; AREAS AB In response to concerns regarding arsenic in soil from a pesticide manufacturing plant, we conducted a biomonitoring study on children younger than 7 years of age, the age category of children most exposed to soil. Urine samples from 77 children (47% participation rate) were analyzed for total arsenic and arsenic species related to ingestion of inorganic arsenic. Older individuals also provided urine (n = 362) and toenail (n = 67) samples. Speciated urinary arsenic levels were similar between children (geometric mean, geometric SD, and range: 4.0, 2.2, and 0.89-17.7 mu g/L, respectively) and older participants (3.8, 1.9, 0.91-19.9 mu g/L) and consistent with unexposed populations. Toenail samples were < 1 mg/kg. Correlations between speciated urinary arsenic and arsenic in soil (r= 0.137, P = 0.39; n = 41) or house dust (r= 0.049, p = 0.73; n = 52) were not significant for children. Similarly, questionnaire responses indicating soil exposure were not associated with increased urinary arsenic levels. Relatively low soil arsenic exposure likely precluded quantification of arsenic exposure above background. C1 Exponent, Bellevue, WA 98007 USA. Exponent, New York, NY USA. Exponent, Washington, DC USA. Battelle Marine Sci Lab, Sequim, WA USA. Emory Univ, Atlanta, GA 30322 USA. RP Tsuji, JS (reprint author), Exponent, 15375 SE 30th Pl,Suite 250, Bellevue, WA 98007 USA. EM tsujij@exponent.com NR 27 TC 24 Z9 24 U1 2 U2 11 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 2005 VL 113 IS 12 BP 1735 EP 1740 DI 10.1289/ehp.8178 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 989ZP UT WOS:000233713200045 PM 16330356 ER PT J AU Bradman, A Eskenazi, B Barr, DB Bravo, R Castorina, R Chevrier, J Kogut, K Harnly, ME McKone, TE AF Bradman, A Eskenazi, B Barr, DB Bravo, R Castorina, R Chevrier, J Kogut, K Harnly, ME McKone, TE TI Organophosphate urinary metabolite levels during pregnancy and after delivery in women living in an agricultural community SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE exposure; organophosphate; pesticides; pregnancy; prenatal; urinary metabolites; women ID DIALKYL PHOSPHATE METABOLITES; 24-HOUR CREATININE CLEARANCE; CONTEMPORARY-USE PESTICIDES; PRESCHOOL-CHILDREN; WASHINGTON-STATE; BIRTH OUTCOMES; EXPOSURE; POPULATION; URBAN; ASSOCIATION AB Little information has been published about pesticide exposures experienced by pregnant women. We measured six dialkyl phosphate (DAP) urinary metabolites of organophosphate (OP) pesticides in 600 pregnant, low-income women living in the Salinas Valley, California, an agricultural area. A total of 28% were employed as farm fieldworkers during pregnancy, and 81% had at least one household member who worked in agriculture. Samples were collected twice during pregnancy (mean=13 and 26 weeks' gestation, respectively) and just after delivery (mean=9 days). As in other studies, dimethyldithiophosphate levels were higher than those of other urinary OP metabolites. Total DAP metabolite levels in samples collected after delivery were higher than in samples collected during pregnancy. Median metabolite levels at the first and second prenatal sampling points and at the postpartum collection were 102.8, 106.8, and 227.2 nmol/L, respectively. Both prenatal and postpartum metabolite levels were higher in these Salinas Valley women than in a sample of women of childbearing age in the general U.S. population (National Health and Nutrition Examination Survey), although the deviation from U.S. reference levels was most pronounced after delivery. Higher DAP metabolite levels in the immediate postpartum period may have implications for estimating dose during pregnancy and for exposure during lactation. C1 Univ Calif Berkeley, Sch Publ Hlth, Ctr Childrens Environm Hlth Res CHAMACOS, Berkeley, CA 94720 USA. Ctr Dis Control & Prevent, Natl Ctr Environm Hlth, Atlanta, GA USA. Calif Dept Hlth Serv, Environm Hlth Invest Branch, Oakland, CA USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Bradman, A (reprint author), Univ Calif Berkeley, Sch Publ Hlth, Ctr Childrens Environm Hlth Res CHAMACOS, 2150 Shattuck Ave,Suite 600, Berkeley, CA 94720 USA. EM abradman@socrates.berkeley.edu RI Barr, Dana/E-6369-2011; Barr, Dana/E-2276-2013 FU NIEHS NIH HHS [P01 ES009605] NR 38 TC 98 Z9 101 U1 2 U2 9 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD DEC PY 2005 VL 113 IS 12 BP 1802 EP 1807 DI 10.1289/ehp.7894 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 989ZP UT WOS:000233713200057 PM 16330368 ER PT J AU Maloney, KO Mulholland, PJ Feminella, JW AF Maloney, KO Mulholland, PJ Feminella, JW TI Influence of catchment-scale military land use on stream physical and organic matter variables in small southeastern plains catchments (USA) (vol 35, pg 677, 2005) SO ENVIRONMENTAL MANAGEMENT LA English DT Correction C1 Auburn Univ, Dept Biol Sci, Auburn, AL 36849 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Maloney, KO (reprint author), Auburn Univ, Dept Biol Sci, 331 Funchess Hall, Auburn, AL 36849 USA. EM malonko@auburn.edu RI Mulholland, Patrick/C-3142-2012 NR 1 TC 2 Z9 2 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD DEC PY 2005 VL 36 IS 6 BP 918 EP 918 DI 10.1007/s00267-005-8651-5 PG 1 WC Environmental Sciences SC Environmental Sciences & Ecology GA 985QC UT WOS:000233392000011 ER PT J AU Kalyuzhnaya, MG Nercessian, O Lapidus, A Chistoserdova, L AF Kalyuzhnaya, MG Nercessian, O Lapidus, A Chistoserdova, L TI Fishing for biodiversity: novel methanopterin-linked C-1 transfer genes deduced from the Sargasso Sea metagenome SO ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID METHYLOBACTERIUM-EXTORQUENS AM1; METHYLENE TETRAHYDROMETHANOPTERIN DEHYDROGENASE; METHYLOTROPHIC BACTERIA; SEQUENCE; ENZYMES; METHANOGENESIS; CYCLOHYDROLASE; METABOLISM; CULTURES; GENOMES AB The recently generated database of microbial genes from an oligotrophic environment populated by a calculated 1800 major phylotypes (the Sargasso Sea metagenome-SSM) presents a great source for expanding local databases of genes indicative of a specific function. In this article we analyse the SSM for the presence of methanopterin-linked C1 transfer genes that are signature for methylotrophy. We conclude that more than 10 phylotypes possessing genes of interest are present in this environment. The sequences representative of these major phylotypes do not appear to belong to any known microbial group capable of methanopterin-linked C1 transfer. Instead, these sequences separate from all known sequences on phylogenetic trees, pointing toward their affiliation with novel microbial phyla. These data imply a broader distribution of methanopterin-linked functions in the microbial world than has been previously known. C1 Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA. Joint Genome Inst, Walnut Creek, CA 94598 USA. RP Chistoserdova, L (reprint author), Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA. EM milachis@u.washington.edu RI Lapidus, Alla/I-4348-2013; OI Lapidus, Alla/0000-0003-0427-8731; Kalyuzhnaya, Marina/0000-0002-9058-7794 NR 37 TC 7 Z9 7 U1 0 U2 3 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1462-2912 J9 ENVIRON MICROBIOL JI Environ. Microbiol. PD DEC PY 2005 VL 7 IS 12 BP 1909 EP 1916 DI 10.1111/j.1462-2920.2005.00798.x PG 8 WC Microbiology SC Microbiology GA 984OE UT WOS:000233313400006 PM 16309389 ER PT J AU Quinn, NWT Jacobs, K Chen, CW Stringfellow, WT AF Quinn, NWT Jacobs, K Chen, CW Stringfellow, WT TI Elements of a decision support system for real-time management of dissolved oxygen in the San Joaquin River Deep Water Ship Channel SO ENVIRONMENTAL MODELLING & SOFTWARE LA English DT Article; Proceedings Paper CT International Symposium on Environmental Software Systems (ISESS 2003) CY 2003 CL Semmering, AUSTRIA DE decision support; dissolved oxygen; modeling; fish AB A decision support system (DSS) has been designed and will be implemented over the next three years to assist in the control and management of episodes of low dissolved oxygen (DO) in a Deep Water Ship Channel (DWSC), located near Stockton, California. The DSS integrates three information technology functions. The first part is the collection and management of data on flow, pollution loads and water quality. The second part is the simulation model which can forecast critical dissolved oxygen depletion in the DWSC and determine management actions necessary to improve dissolved oxygen concentrations. The third part is the graphical user interface, which facilitates the computer simulations and posting of the forecasted dissolved oxygen and remedial measures to a stakeholder group for implementations. (C) 2005 Published by Elsevier Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Calif Dept Water Resources, Sacramento, CA 95814 USA. Systech Engn Inc, San Ramon, CA 94583 USA. RP Quinn, NWT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM nwquinn@lbl.gov RI Stringfellow, William/O-4389-2015; OI Stringfellow, William/0000-0003-3189-5604; Quinn, Nigel/0000-0003-3333-4763 NR 17 TC 12 Z9 13 U1 0 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1364-8152 J9 ENVIRON MODELL SOFTW JI Environ. Modell. Softw. PD DEC PY 2005 VL 20 IS 12 BP 1495 EP 1504 DI 10.1016/j.envsoft.2004.08.014 PG 10 WC Computer Science, Interdisciplinary Applications; Engineering, Environmental; Environmental Sciences SC Computer Science; Engineering; Environmental Sciences & Ecology GA 969SZ UT WOS:000232256300006 ER PT J AU Kim, AG Cardone, CR AF Kim, AG Cardone, CR TI Scatterscore: A reconnaissance method to evaluate changes in water quality SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article DE acid mine drainage; coal utilization by-products; fly ash; mine remediation; water analysis; water quality evaluation ID TREND ANALYSIS; INDEX AB Water quality data collected in periodic monitoring programs are often difficult to evaluate, especially if the number of parameters is large, the sampling schedule varies, and values are of different orders of magnitude. The Scatterscore Water Quality Evaluation was developed to yield a quantitative score, based on all measured variables in periodic water quality reports, indicating positive, negative or random change. This new methodology calculates a reconnaissance score based on the differences between up-gradient (control) versus down-gradient (treatment) water quality data sets. All parameters measured over a period of time at two or more sampling points are compared. The relationship between the ranges of measured values and the ratio of the medians for each parameter produces a data point that falls into one of four sections on a scattergram. The number and average values of positive, negative and random change points is used to calculate a Scatterscore that indicates the magnitude and direction of overall change in water quality. The Scatterscore Water Quality Evaluation, a reconnaissance method to track general changes, has been applied to 20 sites at which coal utilization by-products (CUB) were used to control acid mine drainage (AMD). C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Kim, AG (reprint author), US DOE, Natl Energy Technol Lab, 626 Cochrans Mill Rd, Pittsburgh, PA 15236 USA. EM akim@netl.doe.gov NR 23 TC 3 Z9 3 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD DEC PY 2005 VL 111 IS 1-3 BP 277 EP 295 DI 10.1007/s10661-005-8225-2 PG 19 WC Environmental Sciences SC Environmental Sciences & Ecology GA 987QM UT WOS:000233532400014 PM 16311832 ER PT J AU Denholm, P Holloway, T AF Denholm, P Holloway, T TI Improved accounting of emissions from utility energy storage system operation SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article AB Several proposed utility-scale energy storage systems in the U.S. will use the spare output capacity of existing electric power systems to create the equivalent of new load-following plants that can rapidly respond to fluctuations in electricity demand and increase the flexibility of baseload generators. New energy storage systems using additional generation from existing plants can directly compete with new traditional sources of load-following and peaking electricity, yet this application of energy storage is not required to meet many of the Clean Air Act standards required of new electricity generators (e.g., coal- or gas-fired power plants). This study evaluates the total emissions that will likely result from the operation of a new energy storage facility when coupled with an average existing U.S. coal-fired power plant and estimates that the emission rates Of SO2 and NO, will be considerably higher than the rate of a new plant meeting Clean Air Act standards, even accounting for the efficiency benefits of energy storage. This study suggests that improved emissions "accounting" might be necessary to provide accurate environmental comparisons between energy storage and more traditional sources of electricity generation. C1 Univ Wisconsin, Ctr Sustainabil & Global Environm, Madison, WI 53706 USA. RP Denholm, P (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM paul_denholm@nrel.gov NR 22 TC 10 Z9 10 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC 1 PY 2005 VL 39 IS 23 BP 9016 EP 9022 DI 10.1021/es0505898 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 989ZK UT WOS:000233712700011 PM 16382920 ER PT J AU Morgan, MG Cantor, R Clark, WC Fisher, A Jacoby, HD Janetos, AC Kinzig, AP Melillo, J Street, RB Wilbanks, TJ AF Morgan, MG Cantor, R Clark, WC Fisher, A Jacoby, HD Janetos, AC Kinzig, AP Melillo, J Street, RB Wilbanks, TJ TI Learning from the US National Assessment of Climate Change impacts SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID INTEGRATED ASSESSMENT; POLICY; UNCERTAINTY; FUTURE; MODELS; BASIN AB The U.S. National Assessment of the Potential Consequences of Climate Variability and Change was a federally coordinated nationwide effort that involved thousands of experts and stakeholders. To draw lessons from this effort, the 10 authors of this paper, half of whom were not involved in the Assessment, developed and administered an extensive survey, prepared a series of working papers, and conducted an invitational workshop in Washington, DC, on April 29, 2004. Considering all these sources, the authors conclude that the Assessment was largely successful in implementing its basic design of distributed stakeholder involvement and in achieving its basic objectives. Future assessments could be significantly improved if greater attention were devoted to developing a collective understanding of objectives, preparing guidance materials and providing training for assessment participants, developing a budgeting mechanism which would allow greater freedom in allocating resources across various assessment activities, and creating an environment in which assessments were part of an ongoing process. C1 Carnegie Mellon Univ, Dept Engn & Publ Policy, Pittsburgh, PA 15213 USA. Navigant Consulting Inc, Washington, DC 20006 USA. Harvard Univ, John F Kennedy Sch Govt, Cambridge, MA 02138 USA. Penn State Univ, Dept Agr Econ & Rural Sociol, University Pk, PA 16802 USA. MIT, Sloan Sch Business, Cambridge, MA 02142 USA. H John Heinz 3 Ctr Sci Econ & Environm, Washington, DC 20004 USA. Arizona State Univ, Sch Life Sci, Tempe, AZ 85287 USA. Marine Biol Lab, Ecosyst Ctr, Woods Hole, MA 02543 USA. Environm Canada, Atmospher Environm Serv, Environm Adapt Res Grp, Toronto, ON M3H 5T4, Canada. Oak Ridge Natl Lab, Environm Sci Div, Oak Ridge, TN USA. RP Morgan, MG (reprint author), Carnegie Mellon Univ, Dept Engn & Publ Policy, Pittsburgh, PA 15213 USA. EM granger.morgan@andrew.cmu.edu RI Clark, William/A-4832-2008 NR 29 TC 15 Z9 15 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC 1 PY 2005 VL 39 IS 23 BP 9023 EP 9032 DI 10.1021/es050865i PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 989ZK UT WOS:000233712700012 PM 16382921 ER PT J AU Ona-Nguema, G Morin, G Juillot, F Calas, G Brown, GE AF Ona-Nguema, G Morin, G Juillot, F Calas, G Brown, GE TI EXAFS analysis of arsenite adsorption onto two-line ferrihydrite, hematite, goethite, and lepidocrocite SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID X-RAY-ABSORPTION; IRON-OXIDE MINERALS; ARSENATE ADSORPTION; SURFACE COMPLEXATION; ARSENIC(III); SPECTROSCOPY; MECHANISMS; (HYDR)OXIDES; RETENTION; GEOMETRY AB The modes of As(III)) sorption onto two-line ferrihydrite (Fh), hematite (Hm), goethite (Gt), and lepidocrocite (Lp) have been investigated under anoxic condition using X-ray absorption spectroscopy (XAS). X-ray absorption near-edge structure spectroscopy (XANES) indicates that the absence of oxygen minimized As(III) oxidation due to Fenton reactions. Extended X-ray absorption fine structure spectroscopy (EXAFS) indicates that As(III) forms similar inner-sphere surface complexes on two-line ferrihydrite and hematite that differ from those formed on goethite and lepidocrocite. At high surface coverage,the dominant complex types on Fh and Hm are bidentate mononuclear edge-sharing (E-2) and bidentate binuclear corner-sharing (C-2) with As-Fe distances of 2.90 +/- 0.05 and 3.35 +/- 0.05 angstrom, respectively. The same surface complexes are observed for ferrihydrite at low surface coverage. In contrast, As(III) forms dominantly bidentate binuclear corner-sharing (C-2) sorption complexes on Gt and Lp [d(As-Fe) = 3.3-3.4 angstrom], with a minor amount of monodentate mononuclear corner-sharing (V-1) complexes [d(As-Fe) =3.5-3.6 angstrom]. Bidentate mononuclear edge-sharing (E-2) complexes are virtually absent in Gt and Lp at the high surface coverages that were investigated in the present study. These results are compared with available literature data and discussed in terms of the reactivity of iron(III) (oxyhydr)oxide surface sites. C1 Univ Paris 06, CNRS, UMR, IMPMC,IPGP, F-75015 Paris, France. Univ Paris 07, CNRS, UMR, IMPMC,IPGP, F-75015 Paris, France. Stanford Univ, Surface & Aqueous Geochem Grp, Dept Geog & Environm Sci, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, SLAC, Menlo Pk, CA 94025 USA. RP Morin, G (reprint author), Univ Paris 06, CNRS, UMR, IMPMC,IPGP, 140 Rue Lourmel, F-75015 Paris, France. EM Guillaume.Morin@lmcp.jussieu.fr RI Calas, Georges/B-2445-2012; JUILLOT, Farid/G-7943-2016 OI Calas, Georges/0000-0003-0525-5734; NR 37 TC 183 Z9 186 U1 15 U2 161 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC 1 PY 2005 VL 39 IS 23 BP 9147 EP 9155 DI 10.1021/es050889p PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 989ZK UT WOS:000233712700027 PM 16382936 ER PT J AU Chao, DL Davenport, MP Forrest, S Perelson, AS AF Chao, DL Davenport, MP Forrest, S Perelson, AS TI The effects of thymic selection on the range of T cell cross-reactivity SO EUROPEAN JOURNAL OF IMMUNOLOGY LA English DT Article DE computational modeling; cross-reactivity; T cells; TCR; thymic selection ID SINGLE MHC/PEPTIDE LIGAND; NEGATIVE SELECTION; POSITIVE SELECTION; LYMPHOCYTIC CHORIOMENINGITIS; QUANTITATIVE CONSTRAINTS; ACTIVATION-THRESHOLD; THYMOCYTE SELECTION; VIRAL ESCAPE; REPERTOIRE; RECEPTOR AB Based on the results of a computational model of thymic selection, we propose a mechanism that produces the observed wide range of T cell cross-reactivity. The model suggests that the cross-reactivity of a T cell that survives thymic selection is correlated with its affinity for self peptides. In order to survive thymic selection, a T cell with low affinity for all self peptides expressed in the thymus must have high affinity for major histocompatibility complex (MHC), which makes it highly cross-reactive. A T cell with high affinity for any self peptide must have low MHC affinity to survive selection, which makes it highly specific for its cognate peptide. Our model predicts that (1) positive selection reduces by only 17% the number of T cells that can detect any given foreign peptide, even though it eliminates over 95% of pre-selection cells; (2) negative selection decreases the average cross-reactivity of the pre-selection repertoire by fivefold; and (3) T cells responding to foreign peptides similar to self peptides will have a lower average cross-reactivity than cells responding to epitopes dissimilar to self. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA. Univ New S Wales, Prince Wales Hosp, Dept Haematol, Sydney, NSW, Australia. Univ New S Wales, Ctr Vasc Res, Sydney, NSW, Australia. Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Perelson, AS (reprint author), Los Alamos Natl Lab, MS-K710, Los Alamos, NM 87545 USA. EM asp@lanl.gov OI Chao, Dennis/0000-0002-8253-6321 FU NCI NIH HHS [T32 CA80416, T32 CA080416]; NCRR NIH HHS [R01 RR006555, RR-1P20RR18754, R01 RR0655, P20 RR018754]; NIAID NIH HHS [R37 AI028433, R37 AI28433, R01 AI028433]; NIGMS NIH HHS [P20GM066283]; NIH HHS [R01 OD011095] NR 49 TC 14 Z9 15 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0014-2980 J9 EUR J IMMUNOL JI Eur. J. Immunol. PD DEC PY 2005 VL 35 IS 12 BP 3452 EP 3459 DI 10.1002/eji.200535098 PG 8 WC Immunology SC Immunology GA 996VN UT WOS:000234203400008 PM 16285012 ER PT J AU Basile-Doelsch, I Amundson, R Stone, WEE Masiello, CA Bottero, JY Colin, F Masin, F Borschneck, D Meunier, JD AF Basile-Doelsch, I Amundson, R Stone, WEE Masiello, CA Bottero, JY Colin, F Masin, F Borschneck, D Meunier, JD TI Mineralogical control of organic carbon dynamics in a volcanic ash soil on La Reunion SO EUROPEAN JOURNAL OF SOIL SCIENCE LA English DT Article ID X-RAY-DIFFRACTION; CLAY-MINERALS; NEW-ZEALAND; IMOGOLITE; ALLOPHANE; NMR; SPECTROSCOPY; CHEMISTRY; TURNOVER; ANDOSOLS AB In soil carbon dynamics, the role of physicochemical interactions between organic matter and minerals is not well understood nor quantified. This paper examines the interactions between soil organic matter and poorly crystalline aluminosilicates in a volcanic ash soil on La Reunion in the southern tropics. The soil examined is a profile composed of a surface soil (L-Ao-E-Bh) overlying four buried horizons (horizons 2Bw, 3Bw, 4Bw, 5Bw) that have all developed from successive tephra deposits. Non-destructive spectroscopy (XRD, FTIR and NMR of Si and Al) showed that the mineralogical composition varies from one buried horizon to another. Further, we show that buried horizons characterized by large amounts of crystalline minerals (feldspars, gibbsite) have the least capacity to store organic matter and the fastest carbon turnover. In contrast, buried horizons containing much poorly crystalline material (proto-imogolite and proto-imogolite allophane, denoted LP-ITM) store large amounts of organic matter which turns over very slowly. To understand the mechanism of interactions between LP-ITM and organic matter better, we focused on a horizon formed exclusively of LP-ITM. We demonstrate, using Delta(14)C and delta(13)C values, that even though LP-ITM is extraordinarily effective at stabilizing organic matter, C linked to LP-ITM is still in dynamic equilibrium with its environment and cycles slowly. Based on Delta(14)C values, we estimated the residence time of organic C as similar to 163 000 years for the most stabilized subhorizon, a value that is comparable to that for organic carbon stabilized in Hawaiian volcanic soils. However, this calculation is likely to be biased by the presence of microcharcoal. We characterized the organo-mineral binding between organic matter and LP-ITM by Al-27 NMR, and found that the organic matter is not only chelated to LP-ITM, but it may also limit the polymerization of mineral phases to a stage between proto-imogolite and proto-imogolite allophane. Our results demonstrate the important role of poorly crystalline minerals in the storage of organic C, and show that mineral and organic compounds have to be studied simultaneously to understand the dynamics of organic C in the soil. C1 IRD La Reunion, UMR 161, LSTUR, F-97492 St Clotilde, Reunion. Univ Calif Berkeley, Div Ecosyst Sci, Berkeley, CA 94720 USA. ULB, B-1050 Brussels, Belgium. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Paul Cezanne, IRD, CNRS, CEREGE,UMR, F-13545 Aix En Provence, France. RP Basile-Doelsch, I (reprint author), IRD La Reunion, UMR 161, LSTUR, BP 172, F-97492 St Clotilde, Reunion. EM basile@univ-reunion.fr RI Masiello, Caroline/A-2653-2011; Basile, Isabelle/B-4173-2010; Amundson, Ronald /E-2654-2015 OI Masiello, Caroline/0000-0003-2102-6229; NR 38 TC 49 Z9 51 U1 2 U2 26 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1351-0754 J9 EUR J SOIL SCI JI Eur. J. Soil Sci. PD DEC PY 2005 VL 56 IS 6 BP 689 EP 703 DI 10.1111/j.1365-2389.2005.00703.x PG 15 WC Soil Science SC Agriculture GA 984OJ UT WOS:000233313900001 ER PT J AU Kleber, M Mikutta, R Torn, MS Jahn, R AF Kleber, M Mikutta, R Torn, MS Jahn, R TI Poorly crystalline mineral phases protect organic matter in acid subsoil horizons SO EUROPEAN JOURNAL OF SOIL SCIENCE LA English DT Article ID PARTICLE-SIZE FRACTIONS; SURFACE-AREA; SOILS; CARBON; STABILIZATION; TURNOVER; ANDOSOLS; SORPTION; GERMANY AB Soil minerals are known to influence the biological stability of soil organic matter (SOM). Our study aimed to relate properties of the mineral matrix to its ability to protect organic C against decomposition in acid soils. We used the amount of hydroxyl ions released after exposure to NaF solution to establish a reactivity gradient spanning 12 subsoil horizons collected from 10 different locations. The subsoil horizons represent six soil orders and diverse geological parent materials. Phyllosilicates were characterized by X-ray diffraction and pedogenic oxides by selective dissolution procedures. The organic carbon (C) remaining after chemical removal of an oxidizable fraction of SOM with NaOCl solution was taken to represent a stable organic carbon pool. Stable organic carbon was confirmed as older than bulk organic carbon by a smaller radiocarbon (C-14) content after oxidation in all 12 soils. The amount of stable organic C did not depend on clay content or the content of dithionite-citrate-extractable Fe. The combination of oxalate-extractable Fe and Al explained the greatest amount of variation in stable organic C (R-2 = 0.78). Our results suggest that in acid soils, organic matter is preferentially protected by interaction with poorly crystalline minerals represented by the oxalate-soluble Fe and Al fraction. This evidence suggests that ligand exchange between mineral surface hydroxyl groups and negatively charged organic functional groups is a quantitatively important mechanism in the stabilization of SOM in acid soils. The results imply a finite stabilization capacity of soil minerals for organic matter, limited by the area density of reactive surface sites. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Univ Halle Wittenberg, Inst Plant Nutr & Soil Sci, D-06108 Halle Saale, Germany. RP Kleber, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. EM mkleber@lbl.gov RI Jahn, Reinhold/F-1931-2013; Torn, Margaret/D-2305-2015 NR 28 TC 169 Z9 178 U1 10 U2 105 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1351-0754 J9 EUR J SOIL SCI JI Eur. J. Soil Sci. PD DEC PY 2005 VL 56 IS 6 BP 717 EP 725 DI 10.1111/j.1365-2389.2005.00706.x PG 9 WC Soil Science SC Agriculture GA 984OJ UT WOS:000233313900003 ER PT J AU Chekanov, S Derrick, M Magill, S Miglioranzi, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Pavel, N Molina, AGY 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 Montanari, A Nania, R Aghuzumtsyan, G Bartsch, D Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kind, O Meyer, U Paul, E Rautenberg, J Renner, R Voss, KC Wang, M Wlasenko, M Bailey, DS Brook, NH Cole, JE Heath, GP Namsoo, T Robins, S Capua, M Mastroberardino, A Schioppa, M Susinno, G Tassi, E Kim, JY Ma, KJ Helbich, M Ning, Y Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Galas, A Olkiewicz, K Stopa, P Szuba, D Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Lukasik, J Przybycien, M Suszycki, L Szuba, J Kotanski, A Slominski, W Adler, V Behrens, U Bloch, I Borras, K Drews, G Fourletova, J Geiser, A Gladkov, D Gottlicher, P Gutsche, O Haas, T Hain, W Horn, C Kahle, B Kotz, U Kowalski, H Kramberger, G Lelas, D Lim, H Lohr, B Mankel, R Melzer-Pellmann, IA Nguyen, CN Notz, D Nuncio-Quiroz, AE Raval, A Santamarta, R Schneekloth, U Stosslein, U Wolf, G Youngman, C Zeuner, W Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Karstens, F Dobur, D Vlasov, NN Bussey, PJ Doyle, AT Ferrando, J Hamilton, J Hanlon, S Saxon, DH Skillicorn, IO Gialas, I Carli, T Gosau, T Holm, U Krumnack, N Lohrmann, E Milite, M Salehi, H Schleper, P Schorner-Sadenius, T Stonjek, S Wichmann, K Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Fry, C Goncalo, R Long, KR Tapper, AD Kataoka, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Son, D de Favereau, J Piotrzkowski, K Barreiro, F Glasman, C Gonzalez, O Jimenez, M Labarga, L del Peso, J Terron, J Zambrana, M Barbi, M Corriveau, F Liu, C Padhi, S Plamondon, M Stairs, DG Walsh, R Zhou, C Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Sosnovtsev, V Stifutkin, A Suchkov, S Dementiev, RK Ermolov, PF Gladilin, LK Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Zotkin, DS Zotkin, SA Abt, I Buttner, C Caldwell, A Liu, X Sutiak, J Coppola, N Grigorescu, G Grijpink, S Keramidas, A Kofferman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tiecke, H Vazquez, M Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Ling, TY Allfrey, PD Bell, MA Cooper-Sarkar, AM Cottrell, A Devenish, RCE Foster, B Grzelak, G Gwenlan, C Kohno, T Patel, S Straub, PB Walczak, R Bellan, P Bertolin, A Brugnera, R Carlin, R Ciesielski, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Stanco, L Turcato, M Heaphy, EA Metlica, F Oh, BY Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Hart, JC Abramowicz, H Gabareen, A Kananov, S Kreisel, A Levy, A Kuze, M Kagawa, S Tawara, T Hamatsu, R Kaji, H Kitamura, S Matsuzawa, K Ota, O Costa, M Ferrero, MI Monaco, V Sacchi, R Solano, A Arneodo, M Ruspa, M Fourletov, S Koop, T Martin, JF Mirea, A Butterworth, JM Hall-Wilton, R Jones, TW Loizides, JH Sutton, MR Targett-Adams, C Wing, M Ciborowski, J Kulinski, P Luzniak, P Malka, J Nowak, RJ Pawlak, JM Sztuk, J Tymieniecka, T Tyszkiewicz, A Ukleja, A Ukleja, J Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Hochman, D Karshon, U Lightwood, MS Everett, A Kcira, D Lammers, S Li, L Reeder, DD Rosin, M Ryan, P Savin, AA Smith, WH Dhawan, S Bhadra, S Catterall, CD Cui, Y Hartner, G Menary, S Noor, U Soares, M Standage, J Whyte, J AF Chekanov, S Derrick, M Magill, S Miglioranzi, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Pavel, N Molina, AGY 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 Montanari, A Nania, R Aghuzumtsyan, G Bartsch, D Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kind, O Meyer, U Paul, E Rautenberg, J Renner, R Voss, KC Wang, M Wlasenko, M Bailey, DS Brook, NH Cole, JE Heath, GP Namsoo, T Robins, S Capua, M Mastroberardino, A Schioppa, M Susinno, G Tassi, E Kim, JY Ma, KJ Helbich, M Ning, Y Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Galas, A Olkiewicz, K Stopa, P Szuba, D Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Lukasik, J Przybycien, M Suszycki, L Szuba, J Kotanski, A Slominski, W Adler, V Behrens, U Bloch, I Borras, K Drews, G Fourletova, J Geiser, A Gladkov, D Gottlicher, P Gutsche, O Haas, T Hain, W Horn, C Kahle, B Kotz, U Kowalski, H Kramberger, G Lelas, D Lim, H Lohr, B Mankel, R Melzer-Pellmann, IA Nguyen, CN Notz, D Nuncio-Quiroz, AE Raval, A Santamarta, R Schneekloth, U Stosslein, U Wolf, G Youngman, C Zeuner, W Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Karstens, F Dobur, D Vlasov, NN Bussey, PJ Doyle, AT Ferrando, J Hamilton, J Hanlon, S Saxon, DH Skillicorn, IO Gialas, I Carli, T Gosau, T Holm, U Krumnack, N Lohrmann, E Milite, M Salehi, H Schleper, P Schorner-Sadenius, T Stonjek, S Wichmann, K Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Fry, C Goncalo, R Long, KR Tapper, AD Kataoka, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Son, D de Favereau, J Piotrzkowski, K Barreiro, F Glasman, C Gonzalez, O Jimenez, M Labarga, L del Peso, J Terron, J Zambrana, M Barbi, M Corriveau, F Liu, C Padhi, S Plamondon, M Stairs, DG Walsh, R Zhou, C Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Sosnovtsev, V Stifutkin, A Suchkov, S Dementiev, RK Ermolov, PF Gladilin, LK Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Zotkin, DS Zotkin, SA Abt, I Buttner, C Caldwell, A Liu, X Sutiak, J Coppola, N Grigorescu, G Grijpink, S Keramidas, A Kofferman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tiecke, H Vazquez, M Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Ling, TY Allfrey, PD Bell, MA Cooper-Sarkar, AM Cottrell, A Devenish, RCE Foster, B Grzelak, G Gwenlan, C Kohno, T Patel, S Straub, PB Walczak, R Bellan, P Bertolin, A Brugnera, R Carlin, R Ciesielski, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Stanco, L Turcato, M Heaphy, EA Metlica, F Oh, BY Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Hart, JC Abramowicz, H Gabareen, A Kananov, S Kreisel, A Levy, A Kuze, M Kagawa, S Tawara, T Hamatsu, R Kaji, H Kitamura, S Matsuzawa, K Ota, O Costa, M Ferrero, MI Monaco, V Sacchi, R Solano, A Arneodo, M Ruspa, M Fourletov, S Koop, T Martin, JF Mirea, A Butterworth, JM Hall-Wilton, R Jones, TW Loizides, JH Sutton, MR Targett-Adams, C Wing, M Ciborowski, J Kulinski, P Luzniak, P Malka, J Nowak, RJ Pawlak, JM Sztuk, J Tymieniecka, T Tyszkiewicz, A Ukleja, A Ukleja, J Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Hochman, D Karshon, U Lightwood, MS Everett, A Kcira, D Lammers, S Li, L Reeder, DD Rosin, M Ryan, P Savin, AA Smith, WH Dhawan, S Bhadra, S Catterall, CD Cui, Y Hartner, G Menary, S Noor, U Soares, M Standage, J Whyte, J CA ZEUS Collaborat TI Search for lepton-flavor violation at HERA SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID DEEP-INELASTIC SCATTERING; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; OF-MASS ENERGY; CROSS-SECTIONS; HADRON-COLLISIONS; EVENT GENERATOR; EP COLLISIONS; LEPTOQUARKS; DECAYS AB A search for lepton-flavor-violating interactions ep -> mu X and ep -> tau X has been performed with the ZEUS detector using the entire HERA I data sample, corresponding to an integrated luminosity of 130 pb(-1). The data were taken at center-of-mass energies, root s, of 300 and 318 GeV. No evidence of lepton-flavor violation was found, and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below root s, limits were set on lambda(eq1) root beta(lq), where lambda(eq1) is the coupling of the LQ to an electron and a first-generation quark q(1), and beta(eq) is the branching ratio of the LQ to the final-state lepton l (mu or tau) and a quark q. For LQ masses much larger than root s, limits were set on the four-fermion interaction term lambda(eq alpha)lambda(eq beta)/M(L)(2)Q for LQs that couple to an electron and a quark q(alpha) and to a lepton l and a quark q(beta), where alpha and beta are quark generation indices. Some of the limits are also applicable to lepton-flavor-violating processes mediated by squarks in R-Parity-violating supersymmetric models. In some cases, especially when a higher-generation quark is involved and for the process ep -> tau X, the ZEUS limits are the most stringent to date. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Humboldt Univ, Inst Phys, Berlin, Germany. Univ Bologna, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Ist Nazl Fis Nucl, I-87036 Cosenza, Italy. Chonnam Natl Univ, Kwangju 500757, South Korea. Columbia Univ, Nevis Labs, New York, NY 10027 USA. Inst Nucl Phys, Krakow, Poland. AGH Univ Sci & Technol, Fac Phys & Appl Comp Sci, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. Deutsch Elektronen Synchrotron DESY, Hamburg, Germany. Deutsch Elektronen Synchrotron DESY, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Freiburg, Fak Phys, Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Aegean, Dept Engn Management & Finance, Mitilini, Greece. Univ Hamburg, Inst Expt Phys, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Natl Lab High Energy Phys, KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki 305, Japan. Minist Educ & Sci Lazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Kyungpook Natl Univ, Ctr High Energy Phys, Taegu 702701, South Korea. Catholic Univ Louvain, Inst Phys Nucl, B-1348 Louvain, Belgium. 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. Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany. NIKHEF, Amsterdam, Netherlands. Univ Amsterdam, Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. INFM, I-00185 Rome, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, IL-69978 Tel Aviv, Israel. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 158, Japan. Univ Turin, Turin, Italy. Ist Nazl Fis Nucl, Turin, Italy. Univ Piemonte Orientale, Novara, Italy. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. York Univ, Dept Phys, N York, ON M3J 1P3, Canada. Natl Sci Fdn, Arlington, VA 22230 USA. Max Planck Inst, Munich, Germany. Univ Hamburg, Hamburg, Germany. Univ Lodz, Lodz, Poland. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Suchkov, Sergey/M-6671-2015; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Doyle, Anthony/C-5889-2009; collins-tooth, christopher/A-9201-2012; Ferrando, James/A-9192-2012; Levchenko, B./D-9752-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Wiggers, Leo/B-5218-2015; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Li, Liang/O-1107-2015; Capua, Marcella/A-8549-2015; OI De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Ferrando, James/0000-0002-1007-7816; Wiggers, Leo/0000-0003-1060-0520; Gladilin, Leonid/0000-0001-9422-8636; dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Li, Liang/0000-0001-6411-6107; Capua, Marcella/0000-0002-2443-6525; Arneodo, Michele/0000-0002-7790-7132; Chwastowski, Janusz/0000-0002-6190-8376; Longhin, Andrea/0000-0001-9103-9936; Gutsche, Oliver/0000-0002-8015-9622; Raval, Amita/0000-0003-0164-4337 NR 70 TC 16 Z9 16 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6044 EI 1434-6052 J9 EUR PHYS J C JI Eur. Phys. J. C PD DEC PY 2005 VL 44 IS 4 BP 463 EP 479 DI 10.1140/epjc/s2005-02399-1 PG 17 WC Physics, Particles & Fields SC Physics GA 985RF UT WOS:000233395100001 ER PT J AU Jager, B Stratmann, M Vogelsang, W AF Jager, B Stratmann, M Vogelsang, W TI Longitudinally polarized photoproduction of inclusive hadrons at fixed-target experiments SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID PROMPT PHOTON PRODUCTION; TO-LEADING-ORDER; DEPENDENT STRUCTURE FUNCTIONS; HARD QCD PROCESSES; PARTON DISTRIBUTIONS; CROSS-SECTIONS; FRAGMENTATION FUNCTIONS; MASS SINGULARITIES; SPIN ASYMMETRY; SCATTERING AB We present a detailed phenomenological study of spin-dependent single-inclusive high-p(T) hadron photoproduction with particular emphasis on the kinematics relevant for the Compass and Hermes fixed-target experiments. We carefully examine the theoretical uncertainties associated with the only moderate transverse momenta accessible in such measurements and analyze the sensitivity of the relevant spin asymmetries to the gluon polarization in the nucleon as well as to the completely unknown parton content of circularly polarized photons. C1 Univ Karlsruhe, Inst Theoret Phys, D-76128 Karlsruhe, Germany. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. RP Jager, B (reprint author), Univ Karlsruhe, Inst Theoret Phys, Kaiserstr 12, D-76128 Karlsruhe, Germany. EM marco.stratmann@physik.uni-regensburg.de NR 56 TC 23 Z9 23 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD DEC PY 2005 VL 44 IS 4 BP 533 EP 543 DI 10.1140/epjc/s2005-02380-0 PG 11 WC Physics, Particles & Fields SC Physics GA 985RF UT WOS:000233395100007 ER PT J AU Svaneborg, C Grest, GS Everaers, R AF Svaneborg, C Grest, GS Everaers, R TI Scattering from polymer networks under elongational strain SO EUROPHYSICS LETTERS LA English DT Article ID LOZENGE CONTOUR PLOTS; ANGLE NEUTRON-SCATTERING; RUBBER ELASTICITY; TOPOLOGICAL CONSTRAINTS; SANS INVESTIGATIONS; MODEL NETWORKS; DEFORMATION; COPOLYMERS; RELAXATION AB Molecular-dynamics simulations are used to sample the single-chain form factor of labelled sub-chains in model polymer networks under elongational strain. We observe very similar results for randomly cross-linked and for randomly end-linked networks with the same average strand length and see no indication of lozenge-like scattering patterns reported for some experimental systems. Our data analysis shows that a recent variant of the tube model quantitatively describes scattering in the Guinier regime as well as the macroscopic elastic properties. The observed failure of the theory outside the Guinier regime is shown to be due to non-Gaussian pair-distance distributions. C1 MPI Phys Komplexer Syst, D-01187 Dresden, Germany. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Svaneborg, C (reprint author), MPI Phys Komplexer Syst, Nothnitzerstr 38, D-01187 Dresden, Germany. RI Everaers, Ralf/K-2228-2013 OI Everaers, Ralf/0000-0002-6843-2753 NR 37 TC 6 Z9 6 U1 1 U2 4 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD DEC PY 2005 VL 72 IS 5 BP 760 EP 766 DI 10.1209/epl/i2005-10302-1 PG 7 WC Physics, Multidisciplinary SC Physics GA 989FQ UT WOS:000233658700012 ER PT J AU Chushak, Y Travesset, A AF Chushak, Y Travesset, A TI Solid domains in lipid vesicles and scars SO EUROPHYSICS LETTERS LA English DT Article ID GRAIN-BOUNDARY SCARS; CHOLESTEROL; MEMBRANES; DYNAMICS AB The free energy of a crystalline domain coexisting with a liquid phase on a spherical vesicle may be approximated by an elastic or stretching energy and a line tension term. The stretching energy generally grows as the area of the domain, while the line tension term grows with its perimeter. We show that if the crystalline domain contains defect arrays consisting of finite-length grain boundaries of dislocations (scars), the stretching energy grows linearly with a characteristic length of the crystalline domain. We show that this result is critical to understand the existence of solid domains in lipid-bilayers in the strongly segregated two-phase region even for small relative area coverages. The domains evolve from caps to stripes that become thinner as the line tension is decreased. We also discuss the implications of the results for other experimental systems and for the general problem that consists in finding the ground state of a very large number of particles constrained to move on a fixed geometry and interacting with an isotropic potential. C1 Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Ames Lab, Ames, IA 50011 USA. RP Chushak, Y (reprint author), Iowa State Univ, Dept Phys, Ames, IA 50011 USA. NR 21 TC 9 Z9 9 U1 0 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD DEC PY 2005 VL 72 IS 5 BP 767 EP 773 DI 10.1209/epl/i2005-10307-8 PG 7 WC Physics, Multidisciplinary SC Physics GA 989FQ UT WOS:000233658700013 ER PT J AU Roberts, NW Jaradat, S Hirst, LS Thurlow, MS Wang, Y Wang, ST Liu, ZQ Huang, CC Bai, J Pindak, R Gleeson, HF AF Roberts, NW Jaradat, S Hirst, LS Thurlow, MS Wang, Y Wang, ST Liu, ZQ Huang, CC Bai, J Pindak, R Gleeson, HF TI Biaxiality and temperature dependence of 3-and 4-layer intermediate smectic-phase structures as revealed by resonant X-ray scattering SO EUROPHYSICS LETTERS LA English DT Article ID LIQUID-CRYSTALS AB High-resolution resonant X-ray diffraction experiments have been performed on free-standing films of two selenium-containing antiferroelectric liquid-crystal mixtures. Optical studies had indicated that both mixtures exhibit exceptionally wide intermediate phases, over a total range of >9 K. Through the structural information obtained from the resonant scattering data, we confirm that the intermediate phases of these mixtures show both 3-layer and 4-layer structural periodicities. Moreover, due to the stability of these phases, we report for the first time the temperature dependence of both the helicoidal pitch and distortion angle in the 3-layer phases deduced using the resonant X-ray technique. Analysis using an extension of the theory set out by Levelut and Pansu (Levelut A-M. and Pansu B., Phys. Rev. E, 60 (1999) 6803) shows that over the temperature ranges measured, the pitch changes linearly as a function of temperature whilst the distortion angle remains constant. C1 Univ Manchester, Sch Phys & Astron, Manchester M13 1PL, Lancs, England. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Roberts, NW (reprint author), Univ Manchester, Sch Phys & Astron, Manchester M13 1PL, Lancs, England. RI Roberts, Nicholas/A-5769-2010; Hirst, Linda/A-4862-2008; Bai, Jianming/O-5005-2015 OI Roberts, Nicholas/0000-0002-4540-6683; Hirst, Linda/0000-0002-8306-9366; NR 12 TC 26 Z9 26 U1 0 U2 5 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD DEC PY 2005 VL 72 IS 6 BP 976 EP 982 DI 10.1209/epl/i2005-10336-3 PG 7 WC Physics, Multidisciplinary SC Physics GA 989FS UT WOS:000233658900016 ER PT J AU Millis, AJ Morr, DK Schmalian, J AF Millis, AJ Morr, DK Schmalian, J TI Comment on "Quantum Griffiths effects in metallic systems" by A.H. Castro Neto and B. A. Jones SO EUROPHYSICS LETTERS LA English DT Article C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. RI Schmalian, Joerg/H-2313-2011 NR 7 TC 7 Z9 7 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD DEC PY 2005 VL 72 IS 6 BP 1052 EP 1053 DI 10.1209/epl/i2005-10345-2 PG 2 WC Physics, Multidisciplinary SC Physics GA 989FS UT WOS:000233658900027 ER PT J AU Harrison, FA Christensen, FE Craig, W Hailey, C Baumgartner, W Chen, CMH Chonko, J Cook, WR Koglin, J Madsen, KK Pivavoroff, M Boggs, S Smith, D AF Harrison, Fiona A. Christensen, Finn E. Craig, William Hailey, Charles Baumgartner, Wayne Chen, C. M. H. Chonko, James Cook, W. Rick Koglin, Jason Madsen, Kristin-Kruse Pivavoroff, Michael Boggs, Steven Smith, David TI Development of the HEFT and NuSTAR focusing telescopes SO EXPERIMENTAL ASTRONOMY LA English DT Article; Proceedings Paper CT Workshop on Focusing Telescopes in Nuclear Astrophysics CY SEP 12-15, 2005 CL Bonifacio, FRANCE DE X-ray telescopes; X-ray optics; X-ray detectors AB Hard X-ray/soft gamma-ray astrophysics is on the verge of a major advance with the practical realization of technologies capable of efficiently focusing X-rays above 10 keV. Hard X-ray focusing telescopes can achieve orders of magnitude improvements in sensitivity compared to the instruments based on coded apertures and collimated detectors that have traditionally been employed in this energy band. Compact focal planes enable high-performance detectors with good spectral resolution to be employed in efficient, low-background configurations. We have developed multilayer coated grazing incidence optics and solid state Cadmium Zinc Telluride focal plane systems for the High Energy Focusing Telescope (HEFT) balloon-borne experiment, and for the Nuclear Spectroscopic Telescope Array (NuSTAR) Small Explorer satellite. In this paper we describe the technologies, telescope designs, and performance of both experiments. C1 CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. RP Harrison, FA (reprint author), CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. RI Pivovaroff, Michael/M-7998-2014; Boggs, Steven/E-4170-2015; OI Pivovaroff, Michael/0000-0001-6780-6816; Boggs, Steven/0000-0001-9567-4224; Madsen, Kristin/0000-0003-1252-4891 NR 5 TC 58 Z9 58 U1 1 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 J9 EXP ASTRON JI Exp. Astron. PD DEC PY 2005 VL 20 IS 1-3 BP 131 EP 137 DI 10.1007/s10686-006-9072-z PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 126RD UT WOS:000243531600016 ER PT J AU Smither, RK Abu Saleem, K Roa, DE Beno, MA Von Ballmoos, P Skinner, GK AF Smither, Robert K. Abu Saleem, Khaliefeh Roa, Dante E. Beno, Mark A. Von Ballmoos, Peter Skinner, Gerry K. TI High diffraction efficiency, broadband, diffraction crystals for use in crystal diffraction lenses SO EXPERIMENTAL ASTRONOMY LA English DT Article; Proceedings Paper CT Workshop on Focusing Telescopes in Nuclear Astrophysics CY SEP 12-15, 2005 CL Bonifacio, FRANCE DE gamma-ray astronomy; crystal diffraction; thermal gradient; bent crystal ID PENDELLOSUNG FRINGES; DISTORTED CRYSTALS; GRADIENT CRYSTALS; SI1-XGEX; GROWTH; RAYS AB A major goal of the MAX program is to detect and measure gamma rays produced following the nuclear reactions that take place in a supernova explosion. To detect a reasonable number of supernovae, sensitivities of the order of a few times 10-7 gamma cm-2sec-1 are needed - much better than possible with current instruments. The approach in the MAX program is to use a crystal diffraction lens to collect photons over a large area and concentrate them on a small well-shielded detector, greatly improving the signal to noise ratio. The crystals need to have both high diffraction efficiency and a relatively broad energy bandwidth. With mosaic crystals there is a trade-off between bandwidth and diffraction efficiency - one can have either high efficiency or large bandwidth, but not both without losing too much intensity through atomic absorption. A recent breakthrough in our understanding of crystal diffraction for high-energy gamma rays has made it possible to. develop crystals that have both high diffraction efficiency and a relatively broad energy bandwidth. These crystals have near perfect crystal structure, but the crystalline planes are slightly curved. Such curved planes can be obtained in 3 different ways, by using mixed crystals with a composition gradient, by applying a thermal gradient, and by mechanically bending a near perfect crystal. A series of experiments have been performed on all three types of crystals using high-energy x-ray beams from the Advanced Photon Source at the Argonne National Laboratory. Experiments performed at 3 energies, 93 keV, 123 keV and 153 keV, with both the thermal gradient Si crystals and with the mechanically bent Si crystals, demonstrated that one can achieve diffraction efficiencies approaching 100% with moderate energy bandwidths (Delta E/E = 1.4%) and low atomic absorption (transmission = 0.65), in excellent agreement with theory. The use of this type of diffraction crystal is expected to increase the sensitivity of gamma ray telescopes by a factor of 5 over that possible with normal mosaic crystals. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Smither, RK (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 20 TC 41 Z9 41 U1 1 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 EI 1572-9508 J9 EXP ASTRON JI Exp. Astron. PD DEC PY 2005 VL 20 IS 1-3 BP 201 EP 210 DI 10.1007/s10686-005-9019-9 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 126RD UT WOS:000243531600022 ER PT J AU Roa, DE Smither, RK Zhang, X Nie, K Shieh, YY Ramsinghani, NS Milne, N Kuo, JV Redpath, JL Al-Ghazi, MSAL Caligiuri, P AF Roa, D. E. Smither, R. K. Zhang, X. Nie, K. Shieh, Y. Y. Ramsinghani, N. S. Milne, N. Kuo, J. V. Redpath, J. L. Al-Ghazi, M. S. A. L. Caligiuri, P. TI Development of a new photon diffraction imaging system for diagnostic nuclear medicine SO EXPERIMENTAL ASTRONOMY LA English DT Article; Proceedings Paper CT Workshop on Focusing Telescopes in Nuclear Astrophysics CY SEP 12-15, 2005 CL Bonifacio, FRANCE DE medical imaging; lens; photon diffraction; radiopharmaceuticals; nuclear medicine AB The objective of this project is to develop and construct an innovative imaging system for nuclear medicine and molecular imaging that uses photon diffraction and is capable of generating 1-2 mm spatial resolution images in two or three dimensions. The proposed imaging system would be capable of detecting radiopharmaceuticals that emit 100-200 keV gamma rays which are typically used in diagnostic nuclear medicine and in molecular imaging. The system is expected to be optimized for the 140.6 keV gamma ray from a Tc-99m source, which is frequently used in nuclear medicine. This new system will focus the incoming gamma rays in a manner analogous to a magnifying glass focusing sunlight into a small focal point on a detector's sensitive area. Focusing gamma rays through photon diffraction has already been demonstrated with the construction of a diffraction lens telescope for astrophysics and a scaled-down lens for medical imaging, both developed at Argonne National Laboratory (ANL). In addition, spatial resolutions of 3 mm have been achieved with a prototype medical lens. The proposed imaging system would be comprised of an array of photon diffraction lenses tuned to diffract a specific gamma ray energy (within 100-200 keV) emitted by a common source. The properties of photon diffraction make it possible to diffract only one specific gamma ray energy at a time, which significantly reduces scattering background. The system should be sufficiently sensitive to the detection of small concentrations of radioactivity that can reveal potential tumor sites at their initial stages of development. Moreover, the system's sensitivity would eliminate the need for re-injecting a patient with more radiopharmaceutical if this patient underwent a prior nuclear imaging scan. Detection of a tumor site at its inception could allow for an earlier initiation of treatment and wider treatment options, which can potentially improve the chances for cure. C1 Univ Calif Irvine, Med Ctr, Dept Radiat Oncol, Irvine, CA USA. Univ Calif Irvine, Med Ctr, Dept Radiol Sci, Irvine, CA USA. Argonne Natl Lab, Adv Photon Source Div, Argonne, IL 60439 USA. Univ Chicago, Dept Radiol, Chicago, IL 60637 USA. RP Roa, DE (reprint author), Univ Calif Irvine, Med Ctr, Dept Radiat Oncol, Irvine, CA USA. RI Nie, Ke/E-7476-2012 NR 26 TC 30 Z9 30 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 EI 1572-9508 J9 EXP ASTRON JI Exp. Astron. PD DEC PY 2005 VL 20 IS 1-3 BP 229 EP 239 DI 10.1007/s10686-005-9017-y PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 126RD UT WOS:000243531600025 ER PT J AU von Ballmoos, P Halloin, H Evrard, J Skinner, G Abrosimov, N Alvarez, J Bastie, P Hamelin, B Hernanz, M Jean, P Knodlseder, J Smither, B AF von Ballmoos, Peter Halloin, Hubert Evrard, Jean Skinner, Gerry Abrosimov, Nikolai Alvarez, Jose Bastie, Pierre Hamelin, Bernard Hernanz, Margarida Jean, Pierre Knodlseder, Jurgen Smither, Bob TI CLAIRE: First light for a gamma-ray lens SO EXPERIMENTAL ASTRONOMY LA English DT Article; Proceedings Paper CT Workshop on Focusing Telescopes in Nuclear Astrophysics CY SEP 12-15, 2005 CL Bonifacio, FRANCE DE instrumentation; nuclear astrophysics; gamma ray optics; Laue crystals ID CRYSTAL LENS; TELESCOPE; FLIGHT AB The objective of the R&D project CLAIRE was to prove the principle of a gamma-ray lens for nuclear astrophysics. CLAIRE's Laue diffraction lens has a diameter of 45 cm and a focal length of 277 cm; 556 germanium-si I icon crystals are tuned to focus 170 keV photons onto a 1.5 cm diameter focal spot. Laboratory measurements of the individual crystals and the entire lens have been used to validate a numerical model that we use to estimate the lens performance for a source at infinity. During a stratospheric balloon flight on 2001 June 14, CLAIRE was directed at the Crab nebula by a pointing system able to stabilize the lens to within a few arcseconds of the target. In 72 min of valid pointing time, 33 photons from the Crab were detected in the 3 keV bandpass of the lens: CLAIRE's first light! The performance of CLAIRE's gamma-ray lens, namely the peak reflectivity for a polychromatic source (9 +/- 1%), has been confirmed by ground data obtained on a 205 meter long test range. CLAIRE's measured performance validates the principle of a Laue lens for nuclear astrophysics, opening the way for a space-borne gamma-ray lens telescope that will achieve one to two orders of magnitude improvement in sensitivity over present technologies. C1 CESR, F-31028 Toulouse, France. CNES, F-31401 Toulouse, France. Inst Kristallzuchtung, D-12489 Berlin, Germany. IEEC, Barcelona 08034, Spain. Lab Spect Phys, F-38402 St Martin Dheres, France. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Argonne Natl Lab, Argonne, IL 60439 USA. RP von Ballmoos, P (reprint author), CESR, 9 Av Colonel Roche, F-31028 Toulouse, France. EM pvb@cesr.fr RI Hernanz, Margarita/K-1770-2014 OI Hernanz, Margarita/0000-0002-8651-7910 NR 14 TC 19 Z9 19 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 J9 EXP ASTRON JI Exp. Astron. PD DEC PY 2005 VL 20 IS 1-3 BP 253 EP 267 DI 10.1007/s10686-006-9071-0 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 126RD UT WOS:000243531600027 ER PT J AU Barriere, N von Ballmoos, P Halloin, H Abrosimov, N Alvarez, JM Andersen, K Bastie, P Boggs, S Courtois, P Courvoisier, T Harris, M Hernanz, M Isern, J Jean, P Knodlseder, J Skinner, G Smither, B Ubertini, P Vedrenne, G Weidenspointner, G Wunderer, C AF Barriere, N. von Ballmoos, P. Halloin, H. Abrosimov, N. Alvarez, J. M. Andersen, K. Bastie, P. Boggs, S. Courtois, P. Courvoisier, T. Harris, M. Hernanz, M. Isern, J. Jean, P. Knodlseder, J. Skinner, G. Smither, B. Ubertini, P. Vedrenne, G. Weidenspointner, G. Wunderer, C. TI MAX, a Laue diffraction lens for nuclear astrophysics SO EXPERIMENTAL ASTRONOMY LA English DT Article; Proceedings Paper CT Workshop on Focusing Telescopes in Nuclear Astrophysics CY SEP 12-15, 2005 CL Bonifacio, FRANCE DE instrumentation : gamma-ray Laue lens; gamma-ray astrophysics; mosaic crystals AB The next generation of instrumentation for nuclear astrophysics will have to achieve a factor of 10-100 improvement in sensitivity over present technologies. With the focusing gamma-ray telescope MAX we take up this challenge: combining unprecedented sensitivity with high spectral and angular resolution, and the capability of measuring the 4 polarization of the incident photons. The feasibility of such a crystal diffraction gamma-ray lens has recently been demonstrated with the prototype lens CLAIRE. MAX is a proposed mission which will make use of satellite formation flight to achieve 86 m focal length, with the Laue lens being carried by one satellite and the detector by the other. In the current design, the Lane diffraction lens of MAX will consist of 13740 copper and germanium (Ge(1-x)Si(x), x similar to 0.02) crystal tiles arranged on 36 concentric rings. It simultaneously focuses in two energy bands, each centred on one of the main scientific objectives of the mission: the 800-900 keV band is dedicated to the study of nuclear gamma-ray lines from type la supernovae (e.g. (56)Co decay line at 847 keV) while the 450-530 keV band focuses on electron-positron annihilation (511 keV emission) from the Galactic centre region with the aim of resolving potential point sources. MAX promises a breakthrough in the study of point sources at gamma-ray energies by combining high narrow-line sensitivity (better than 10(-6) cm(-2) s(-1)) and high energy resolution (E/dE similar to 500). The mission has successfully undergone a pre-phase A study with the French Space Agency CNES, and continues to evolve: new diffracting materials such as bent or composite crystals seem very promising. C1 Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Inst Kristallzuchtung, D-12489 Berlin, Germany. Coll France, APC, F-75231 Paris, France. Univ Calif Berkeley, Space Sci Lab 7450, Berkeley, CA 94720 USA. ISDC, CH-1290 Versoix, Switzerland. CSIC, IEEC, Bellaterra 08193, Barcelona, Spain. Argonne Natl Lab, Argonne, IL 60439 USA. Ist Astrofis Spaziale & Fis Cosm, I-00133 Rome, Italy. RP Barriere, N (reprint author), Ctr Etud Spatiale Rayonnements, 9 Ave Colonel Roche,BP 4143, F-31028 Toulouse 4, France. EM barriere@cesr.fr RI Hernanz, Margarita/K-1770-2014; Isern, Jordi/B-1844-2015; Boggs, Steven/E-4170-2015 OI Hernanz, Margarita/0000-0002-8651-7910; Isern, Jordi/0000-0002-0819-9574; Boggs, Steven/0000-0001-9567-4224 NR 24 TC 16 Z9 16 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 J9 EXP ASTRON JI Exp. Astron. PD DEC PY 2005 VL 20 IS 1-3 BP 269 EP 278 DI 10.1007/s10686-006-9058-x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 126RD UT WOS:000243531600028 ER PT J AU Boggs, S Bandstra, M Bowen, J Coburn, W Lin, R Wunderer, C Zoglauer, A Amman, M Luke, P Jean, P von Ballmoos, P AF Boggs, Steven Bandstra, Mark Bowen, Jason Coburn, Wayne Lin, Robert Wunderer, Cornelia Zoglauer, Andreas Amman, Mark Luke, Paul Jean, Pierre von Ballmoos, Peter TI Performance of the Nuclear Compton Telescope SO EXPERIMENTAL ASTRONOMY LA English DT Article; Proceedings Paper CT Workshop on Focusing Telescopes in Nuclear Astrophysics CY SEP 12-15, 2005 CL Bonifacio, FRANCE DE Compton telescopes; gamma-ray spectroscopy; gamma-ray astronomy; balloon payloads ID DETECTORS; FLIGHT AB On 1 June 2005, the prototype Nuclear Compton Telescope (NCT) flew on a high altitude balloon from Fort Sumner, New Mexico. NCT is a balloon-borne soft gamma-ray (0.2-10 MeV) telescope for studying astrophysical sources of nuclear line emission and gamma-ray polarization. Our program is designed to develop and test technologies and analysis techniques crucial for the Advanced Compton Telescope; however, our detector design and configuration is also well matched to the focal plane requirements for focusing Lane lenses. The NCT prototype utilizes two, 3D imaging germanium detectors (GeDs) in a novel, ultra-compact design optimized for nuclear line emission in the 0.5-2 MeV range. Our prototype flight provides a critical test of the novel detector technologies, analysis techniques, and background rejection procedures developed for high resolution Compton telescopes. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. UPS, CNRS, Ctr Etud Spatiale Rayonnements, Toulouse, France. RP Boggs, S (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Boggs, Steven/E-4170-2015 OI Boggs, Steven/0000-0001-9567-4224 NR 13 TC 4 Z9 4 U1 1 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 J9 EXP ASTRON JI Exp. Astron. PD DEC PY 2005 VL 20 IS 1-3 BP 389 EP 396 DI 10.1007/s10686-006-9051-4 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 126RD UT WOS:000243531600039 ER PT J AU Ozdoganlar, OB Hansche, BD Carne, T AF Ozdoganlar, OB Hansche, BD Carne, T TI Experimental modal analysis for microelectromechanical systems SO EXPERIMENTAL MECHANICS LA English DT Article DE MEMS; microsystems; LIGA; MEMS dynamics; gas damping; modal analysis ID MICROSTRUCTURES; DEVICES AB The structural dynamics behavior of microelectromechanical systems (MEMS), which include moving, overhung, and compliant subcomponents, plays a pivotal role in determining their performance and reliability. Traditionally, experimental modal analysis is used to characterize the dynamic behavior of structures, as well as to derive, validate, update, and correct analytical and numerical models. Due to their small size, however, conventional modal testing methods cannot be directly applied to microstructures. In this paper we provide an overview of modal testing techniques for microsys- tems. A particular experimental modal analysis methodology that includes base excitation via a piezoelectric shaker and measurement through a laser interferometer is then described and evaluated. A distinguishing characteristic of the methodology is its simplicity, including its simple setup and off-the-shelf components. The modal model is derived for the base excitation of microcantilever beams. The effectiveness of the methodology is illustrated through various experiments on polysilicon microcantilevers for different geometries and ambient pressures. Analysis of the damping data for different pressures has confirmed the well-documented fact that the structural damping in microsystems can be considerably less than damping arising from interaction with the ambient gases. C1 Carnegie Mellon Univ, Dept Mech Engn, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Carnegie Mellon Univ, Dept Mech Engn, Pittsburgh, PA 15213 USA. EM ozdoganlar@cmu.edu NR 35 TC 52 Z9 52 U1 1 U2 10 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0014-4851 EI 1741-2765 J9 EXP MECH JI Exp. Mech. PD DEC PY 2005 VL 45 IS 6 BP 498 EP 506 DI 10.1177/0014485105059991 PG 9 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 986NS UT WOS:000233457600003 ER PT J AU McLarnon, CR Granite, EJ Pennline, HW AF McLarnon, CR Granite, EJ Pennline, HW TI The PCO process for photochemical removal of mercury from flue gas SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE mercury; flue gas; sensitized oxidation; ultraviolet; photochemical ID EXCITED MERCURY; ISOTOPES; VAPOR; ATOMS; SEPARATION; DIOXIDE AB A promising technology has been developed to capture and remove elemental mercury species from coal-fired power plants. Powerspan Corp. has licensed the technology and initiated a bench and pilot test program to develop the Photochemical Oxidation, or PCO (TM), process for commercial application with subbituminous and lignite fuels. The process has the potential to serve as a low cost mercury oxidation technology that will facilitate elemental mercury removal in a downstream SO2 scrubber, wet electrostatic precipitator (WESP), or baghouse. It uses 254-nm (nanometer) ultraviolet light from a mercury lamp to produce an excited state mercury species in the flue gas, leading to oxidation of elemental mercury. This paper presents results of Powerspan's initial bench-scale testing on a simulated flue gas stream. Preliminary testing conducted in Powerspan's bench-scale facility showed greater than 90% oxidation and removal of elemental mercury. The process also has potential to serve as a low cost method for the removal of mercury from waste incinerator flue gases. (c) 2005 Elsevier B.V. All rights reserved. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Powerspan Corp, New Durham, NH 03855 USA. RP Granite, EJ (reprint author), US DOE, Natl Energy Technol Lab, POB 10940,MS 58-106, Pittsburgh, PA 15236 USA. EM evan.granite@netl.doe.gov NR 11 TC 53 Z9 55 U1 1 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD DEC PY 2005 VL 87 IS 1 BP 85 EP 89 DI 10.1016/j.fuproc.2005.07.001 PG 5 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 979WD UT WOS:000232974800011 ER PT J AU Tan, JS Mohandas, N Conboy, JG AF Tan, JS Mohandas, N Conboy, JG TI Evolutionarily conserved coupling of transcription and alternative splicing in the EPB41 (protein 4.1R) and EPB41L3 (protein 4.1B) genes SO GENOMICS LA English DT Article DE protein 4.1R; alternative first exons; alternative mRNA splicing; protein 4.1B; transcription and splicing coupling ID RNA-POLYMERASE-II; C-TERMINAL DOMAIN; NUCLEAR-MATRIX; EXPRESSION; DIVERSITY; INTERACTS; PROMOTERS; SUBUNIT; CTD; EWS AB Recent studies have shown that transcription and alternative splicing can be mechanistically coupled. In the EPB41 (protein 4.1R) and EPB41L3 (protein 4.1B) genes, we showed previously that promoter/alternative first exon choice is coupled to downstream splicing events in exon 2. Here we demonstrate that this coupling is conserved among several vertebrate classes from fish to mammals. The EPB41 and EPB41L3 genes from fish, bird, amphibian, and mammal genomes exhibit shared features including alternative first exons and differential splice acceptors in exon 2. In all cases, the 5'-most exon (exon I A) splices exclusively to a weaker internal acceptor site in exon 2, skipping a fragment designated as exon 2'. Conversely.. alternative first exons 1B and 1C always splice to the stronger first acceptor site, retaining exon 2. These correlations are independent of cell type or species of origin. Since exon 2' contains a translation initiation site, splice variants generate protein isoforms with distinct N-termini. We propose that these genes represent a physiologically relevant model system for mechanistic analysis of transcription-coupled alternative splicing. (c) 2005 Elsevier Inc. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Genom Dept, Berkeley, CA 94720 USA. New York Blood Ctr, Red Cell Physiol Grp, New York, NY 10021 USA. RP Conboy, JG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. EM JGConboy@lbl.gov FU NHLBI NIH HHS [HL45182]; NIDDK NIH HHS [DK32904, P01 DK032094] NR 34 TC 9 Z9 9 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD DEC PY 2005 VL 86 IS 6 BP 701 EP 707 DI 10.1016/j.ygeno.2005.08.005 PG 7 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 999NL UT WOS:000234396200009 PM 16242908 ER PT J AU Neal, AL Bank, TL Hochella, MF Rosso, KM AF Neal, AL Bank, TL Hochella, MF Rosso, KM TI Cell adhesion of Shewanella oneidensis to iron oxide minerals: Effect of different single crystal faces SO GEOCHEMICAL TRANSACTIONS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; HYDROUS FERRIC-OXIDE; FE(III) OXIDE; MICROBIAL REDUCTION; BACTERIAL ADHESION; PUTREFACIENS MR-1; IRON(III) OXIDES; OUTER-MEMBRANE; POROUS-MEDIA; ALGA BRY AB The results of experiments designed to test the hypothesis that near-surface molecular structure of iron oxide minerals influences adhesion of dissimilatory iron reducing bacteria are presented. These experiments involved the measurement, using atomic force microscopy, of interaction forces generated between Shewanella oneidensis MR-1 cells and single crystal growth faces of iron oxide minerals. Significantly different adhesive force was measured between cells and the (001) face of hematite, and the (100) and (111) faces of magnetite. A role for electrostatic interactions is apparent. The trend in relative forces of adhesion generated at the mineral surfaces is in agreement with predicted ferric site densities published previously. These results suggest that near-surface structure does indeed influence initial cell attachment to iron oxide surfaces; whether this is mediated via specific cell surface-mineral surface interactions or by more general interfacial phenomena remains untested. (C) 2005 American Institute of Physics. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29808 USA. Virginia Polytech Inst & State Univ, Dept Geosci, Blacksburg, VA 24060 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Neal, AL (reprint author), Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29808 USA. EM neal@srel.edu RI Neal, Andrew/C-7596-2011 NR 47 TC 20 Z9 21 U1 3 U2 26 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1467-4866 J9 GEOCHEM T JI Geochem. Trans. PD DEC PY 2005 VL 6 IS 4 BP 77 EP 84 DI 10.1063/1.2151110 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 998UV UT WOS:000234346300002 ER PT J AU Jaisi, DP Kukkadapu, RK Eberl, DD Dong, HL AF Jaisi, DP Kukkadapu, RK Eberl, DD Dong, HL TI Control of Fe(III) site occupancy on the rate and extent of microbial reduction of Fe(III) in nontronite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HYDROUS FERRIC-OXIDE; DIOCTAHEDRAL SMECTITES; MOSSBAUER-SPECTROSCOPY; CLAY-MINERALS; STRUCTURAL FE(III); CRYSTAL-CHEMISTRY; ELECTRON-TRANSFER; IRON REDUCTION; GREEN RUST; DISSOLUTION AB A quantitative study was performed to understand how Fe(III) site occupancy controls Fe(III) bioreduction in nontronite by Shewanella putrefaciens CN32. NAu-1 and NAu-2 were nontronites and contained Fe(III) in different structural sites with 16 and 23% total iron (w/w), respectively, with almost all iron as Fe(III). Mossbauer spectroscopy showed that Fe(III) was present in the octahedral site in NAu-1 (with a small amount of goethite), but in both the tetrahedral and the octahedral sites in NAu-2. Mossbauer data further showed that the octahedral Fe(III) in NAu-2 existed in at least two environments- trans (M1) and cis (M2) sites. The microbial Fe(III) reduction in NAu-1 and NAu-2 was studied in batch cultures at a nontronite concentration of 5 mg/mL in bicarbonate buffer with lactate as the electron donor. The unreduced and bioreduced nontronites were characterized by X-ray diffraction (XRD), Mossbauer spectroscopy, and transmission electron microscopy (TEM). In the presence of an electron shuttle, anthraquinone-2,6-disulfonate (AQDS), the extent of bioreduction was 11%-16% for NAu-1 but 28%-32% for NAu-2. The extent of reduction in the absence of AQDS was only 5%-7% for NAu-1 but 14%-18% for NAu-2. The control experiments with heat killed cells and without cells did not show any appreciable reduction (< 2%). The extent of reduction in experiments performed with a dialysis membrane to separate cells from clays (without AQDS) was 2%-3% for NAu-1 but 5%-7% for NAu-2, suggesting that cells probably released an electron shuttling compound and/or Fe(III) chelator. The reduction rate was also faster in NAu-2 than that in NAu-1. Mossbauer data of the bioreduced nontronite materials indicated that the Fe(III) reduction in NAu-1 was mostly from the presence of goethite, whereas the reduction in NAu-2 was due to the presence of the tetrahedral and trans-octahedral Fe(III) in the structure. The measured aqueous Fe(II) was negligible. As a result of bioreduction, the average nontronite particle thickness remained nearly the same (from 2.1 to 2.5 nm) for NAu-1, but decreased significantly from 6 to 3.5 nm for NAu-2 with a concomitant change in crystal size distribution. The decrease in crystal size suggests reductive dissolution of nontronite NAu-2, which was supported by aqueous solution chemistry (i.e., aqueous Si). These data suggest that the more extensive Fe(III) bioreduction in NAu-2 was due to the presence of the tetrahedral and the trans-octahedral Fe(III), which was presumed to be more reducible. The biogenic Fe(II) was not associated with biogenic solids or in the aqueous solution. We infer that it may be either adsorbed onto surfaces of nontronite particles/bacteria or in the structure of nontronite. Furthermore, we have demonstrated that natural nontronite clays were capable of supporting cell growth even in medium without added nutrients, possibly due to presence of naturally existing nutrients in the nontronite clays. These results suggest that crystal chemical environment of Fe(III) is an important determinant in controlling the rate and extent of microbial reduction of Fe(III) in nontronite. Copyright (c) 2005 Elsevier Ltd. C1 Miami Univ, Dept Geol, Oxford, OH 45056 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. US Geol Survey, Boulder, CO 80303 USA. RP Dong, HL (reprint author), Miami Univ, Dept Geol, Oxford, OH 45056 USA. EM dongh@muohio.edu NR 57 TC 73 Z9 77 U1 4 U2 28 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 1 PY 2005 VL 69 IS 23 BP 5429 EP 5440 DI 10.1016/j.gca.2005.07.008 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 999TP UT WOS:000234413700004 ER PT J AU Patton, HJ Bonner, JL Gupta, IN AF Patton, HJ Bonner, JL Gupta, IN TI Rg excitation by underground explosions: insights from source modelling the 1997 Kazakhstan depth-of-burial experiment SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE explosion source; near-field; Rg waves; seismic moment; tensile failure ID SURFACE-WAVES; NUCLEAR-EXPLOSIONS; SPALL; RELEASE; NTS; LG AB Near-field seismograms of chemical explosions detonated as part of the 1997 depth-of-burial (DOB) experiment at the former Semipalatinsk nuclear test site provide an excellent opportunity to study the excitation of Rg waves for source effects. Rg waves were identified with particle-motion analysis and isolated from other arrivals using group velocity filtering. Amplitude and phase spectra of Rg waves were corrected for path effects based on observed attenuation in the near-field and path-specific phase velocity models. The path-corrected spectra were inputs to a grid-search method for finding source parameters of an axisymmetric source consisting of a monopole plus a compensated linear vector dipole (CLVD) or a horizontal tensile crack. The suite of observations, including ground-zero accelerograms and geophysical data from borehole logs, are best satisfied by models involving a CLVD with static (zero-frequency) seismic moment M-o. The CLVD source is related to tensile failure occurring at depths above the shotpoint. A static M-o distinguishes this source from classical models of spall, which are usually characterized by horizontal cracks that dynamically open and close with no permanent displacement (i.e. no static M-o). The CLVD source in this study appears to be more closely related to a driven block motion model envisaged by Masse. Rg source amplitudes are consistent with m(b) (Lg) measurements at station MAK, as would be expected if near-field Rg-to-S scattering plays a role in generating S waves observed at regional distances. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Weston Geophys Corp, Lufkin, TX 75901 USA. Multimax Inc, Largo, MD 20774 USA. RP Los Alamos Natl Lab, F665, Los Alamos, NM 87545 USA. EM patton@lanl.gov NR 33 TC 11 Z9 11 U1 1 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD DEC PY 2005 VL 163 IS 3 BP 1006 EP 1024 DI 10.1111/j.1365-246X.02752.x PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 986FH UT WOS:000233435000013 ER PT J AU Jastrow, JD Miller, RM Matamala, R Norby, RJ Boutton, TW Rice, CW Owensby, CE AF Jastrow, JD Miller, RM Matamala, R Norby, RJ Boutton, TW Rice, CW Owensby, CE TI Elevated atmospheric carbon dioxide increases soil carbon SO GLOBAL CHANGE BIOLOGY LA English DT Article DE carbon sequestration; C-13 stable isotope; FACE experiment; meta-analysis; microaggregates; open-top chamber; roots; soil organic matter; sweetgum forest; tallgrass prairie grassland ID TALLGRASS PRAIRIE ECOSYSTEM; CO2 ENRICHMENT; ORGANIC-CARBON; BIOMASS PRODUCTION; C SEQUESTRATION; FOREST; GRASSLAND; RESPONSES; TURNOVER; DYNAMICS AB The general lack of significant changes in mineral soil C stocks during CO2-enrichment experiments has cast doubt on predictions that increased soil C can partially offset rising atmospheric CO2 concentrations. Here, we show, through meta-analysis techniques, that these experiments collectively exhibited a 5.6% increase in soil C over 2-9 years, at a median rate of 19 g C m(-2) yr(-1). We also measured C accrual in deciduous forest and grassland soils, at rates exceeding 40 g C m(-2) yr(-1) for 5-8 years, because both systems responded to CO2 enrichment with large increases in root production. Even though native C stocks were relatively large, over half of the accrued C at both sites was incorporated into microaggregates, which protect C and increase its longevity. Our data, in combination with the meta-analysis, demonstrate the potential for mineral soils in diverse temperate ecosystems to store additional C in response to CO2 enrichment. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Texas A&M Univ, Dept Rangeland Ecol & Management, College Stn, TX 77843 USA. Kansas State Univ, Dept Agron, Manhattan, KS 66506 USA. RP Jastrow, JD (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave, Argonne, IL 60439 USA. EM jdjastrow@anl.gov RI Norby, Richard/C-1773-2012; Boutton, Thomas/C-5821-2016 OI Norby, Richard/0000-0002-0238-9828; Boutton, Thomas/0000-0002-7522-5728 NR 30 TC 141 Z9 147 U1 4 U2 76 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1354-1013 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD DEC PY 2005 VL 11 IS 12 BP 2057 EP 2064 DI 10.1111/j.1365-2486.2005.01077.x PG 8 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 995FX UT WOS:000234087300001 ER PT J AU Mourant, J Kunapareddy, P Carpenter, S Freyer, JP AF Mourant, J Kunapareddy, P Carpenter, S Freyer, JP TI Vibrational spectroscopy for identification of biochemical changes accompanying carcinogenesis and the formation of necrosis SO GYNECOLOGIC ONCOLOGY LA English DT Editorial Material ID INFRARED RAMAN-SPECTROSCOPY; IN-VIVO DETECTION C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Mourant, J (reprint author), Los Alamos Natl Lab, Biosci Div, MSE535, Los Alamos, NM 87545 USA. EM jmourant@lanl.gov NR 3 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0090-8258 J9 GYNECOL ONCOL JI Gynecol. Oncol. PD DEC PY 2005 VL 99 IS 3 SU 1 BP S58 EP S60 DI 10.1016/j.ygyno.2005.07.044 PG 3 WC Oncology; Obstetrics & Gynecology SC Oncology; Obstetrics & Gynecology GA 000ZV UT WOS:000234502500013 PM 16419186 ER PT J AU Potter, CA AF Potter, CA TI More about misconceptions by Charles Potter - Response to Lloyd SO HEALTH PHYSICS LA English DT Letter ID INDUCED SKELETAL MALIGNANCY; EXPOSURE; DEPEND C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Potter, CA (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD DEC PY 2005 VL 89 IS 6 BP 690 EP 691 DI 10.1097/00004032-200512000-00016 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 991CI UT WOS:000233789400015 ER PT J AU Celina, M Dargaville, TR Assink, RA Martin, JW AF Celina, M Dargaville, TR Assink, RA Martin, JW TI Selection and optimization of piezoelectric polyvinylidene fluoride polymers for adaptive optics in space environments SO HIGH PERFORMANCE POLYMERS LA English DT Article DE polyvinylidene fluoride (PVDF); polymer; materials performance; space environment; exposure; selection; characterization ID ELECTROMECHANICAL PROPERTIES; POLY(VINYLIDENE FLUORIDE); F-19 MAS; FLUOROPOLYMERS; RADIATION AB Various piezoelectric polymers based on polyvinylidene fluoride (PVDF) are of interest for large aperture space-based telescopes. Dimensional adjustments of adaptive polymer films depend on charge deposition and require a detailed understanding of the piezoelectric material responses which are expected to deteriorate owing to strong vacuum UV, gamma-, X-ray, energetic particles and atomic oxygen exposure. We have investigated the degradation of PVDF and its copolymers under various stress environments detrimental to reliable operation in space. Initial radiation aging studies have shown complex material changes with lowered Curie temperatures, complex material changes with lowered melting points, morphological transformations and significant crosslinking, but little influence on piezoelectric d(33) constants. Complex aging processes have also been observed in accelerated temperature environments inducing annealing phenomena and cyclic stresses. The results suggest that poling and chain orientation are negatively affected by radiation and temperature exposure. A framework for dealing with these complex material qualification issues and overall system survivability predictions in low earth orbit conditions has been established. It allows for improved material selection, feedback for manufacturing and processing, material optimization/stabilization strategies and provides guidance on any alternative materials. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Celina, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mccelin@sandia.gov OI Dargaville, Tim/0000-0003-4665-9508 NR 30 TC 9 Z9 9 U1 2 U2 6 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0954-0083 J9 HIGH PERFORM POLYM JI High Perform. Polym. PD DEC PY 2005 VL 17 IS 4 BP 575 EP 592 DI 10.1177/0954008305052206 PG 18 WC Polymer Science SC Polymer Science GA 987UX UT WOS:000233544000008 ER PT J AU Efroymson, RA Dale, VH Baskaran, LM Chang, M Aldridge, M Berry, MW AF Efroymson, RA Dale, VH Baskaran, LM Chang, M Aldridge, M Berry, MW TI Planning transboundary ecological risk assessments at military installations SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE ecological risk assessment; regional risk assessment; problem formulation; military; scaling ID ALTITUDE AIRCRAFT OVERFLIGHTS; ASSESSMENT FRAMEWORK; CONCEPTUAL MODELS; ECOSYSTEMS; LANDSCAPE; MANAGEMENT; SCALE; USA; IMPAIRMENTS; WILDLIFE AB Ecological risk assessments at military installations that are performed to support natural resources management objectives rely on information from the surrounding region. Stressors such as noise, ozone, and ozone precursors cross installation boundaries, and effects of urbanization and highway development are regional in scale. Ecological populations are not limited to one side of the installation boundary. Therefore, a framework for transboundary ecological risk assessment at military installations is under development. This article summarizes the problem formulation stage. Components include: (1) regional management goals such as installation Integrated Natural Resources Management Plans and land acquisition, (2) involvement of multiple stressors, and (3) large-scale assessment endpoint entities. Challenges of selecting measures of exposure include: quantifying exposure to aggregate stressors, describing land cover consistently in the region, describing rates of land-cover transition, scaling local measurements to a region, and aggregating or isolating exposures from within and outside of the installation. Measures of effect that are important to transboundary or regional ecological risk assessments at military installations are those that represent: effects at a distance from the stressor, large-scale effects, effects of habitat change or fragmentation, spatial extrapolations of localized effects, and integrated effects of multiple stressors. These factors are reflected in conceptual models. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. RP Efroymson, RA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. EM efroymsonra@ornl.gov RI Dale, Virginia/B-6023-2009; Baskaran, Latha/D-9754-2016; OI Baskaran, Latha/0000-0001-8487-3914; Efroymson, Rebecca/0000-0002-3190-880X; Berry, Michael/0000-0002-9191-9148 NR 78 TC 5 Z9 5 U1 2 U2 6 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1080-7039 EI 1549-7860 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD DEC PY 2005 VL 11 IS 6 BP 1193 EP 1215 DI 10.1080/10807030500346722 PG 23 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 993PP UT WOS:000233967700011 ER PT J AU Huang, SR Chen, LS Libina, N Janes, J Martin, GM Campisi, J Oshima, J AF Huang, SR Chen, LS Libina, N Janes, J Martin, GM Campisi, J Oshima, J TI Correction of cellular phenotypes of Hutchinson-Gilford Progeria cells by RNA interference SO HUMAN GENETICS LA English DT Article DE progeroid syndrome; LMNA; aging; atherosclerosis ID LAMIN-A; REPLICATIVE SENESCENCE; NUCLEAR ARCHITECTURE; TELOMERE LENGTH; LIFE-SPAN; IN-VITRO; EXPRESSION; MUTATIONS; FIBROBLASTS; APOPTOSIS AB The great majority of cases of the Hutchinson-Gilford progeroid syndrome (HGPS) ("Progeria of Childhood") are caused by a single nucleotide mutation (1824 C- > T) in the LMNA gene which encodes lamin A and C, nuclear intermediate filaments that are important components of the nuclear lamina. The resultant mutant protein (Delta 50 lamin A) is thought to act in a dominant fashion. We exploited RNA interference technology to suppress A50 lamin A expression, with the long range goal of intervening in the pathogenesis of the coronary artery atherosclerosis that typically leads to the death of HGPS patients. Short hairpin RNA (shRNA) constructs were designed to target the mutated pre-spliced or mature LMNA mRNAs, and were expressed in HGPS fibroblasts carrying the 1824 C- > T mutations using lentiviruses. One of the shRNAs targeted to the mutated mRNA reduced the expression levels of A50 lamin A to 26% or lower. The reduced expression was associated with amelioration of abnormal nuclear morphology, improvement of proliferative potential, and reduction in the numbers of senescent cells. These findings provide a rationale for potential gene therapy. C1 Univ Washington, Dept Pathol, Seattle, WA 98195 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Oshima, J (reprint author), Univ Washington, Dept Pathol, Box 357470,HSB K-543,1959 NE Pacific Ave, Seattle, WA 98195 USA. EM picard@u.washington.edu NR 30 TC 50 Z9 52 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0340-6717 J9 HUM GENET JI Hum. Genet. PD DEC PY 2005 VL 118 IS 3-4 BP 444 EP 450 DI 10.1007/s00439-005-0051-7 PG 7 WC Genetics & Heredity SC Genetics & Heredity GA 001NF UT WOS:000234542900015 PM 16208517 ER PT J AU Olsson, RH Wise, KD AF Olsson, RH Wise, KD TI A three-dimensional neural recording microsystem with implantable data compression circuitry SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Article; Proceedings Paper CT IEEE International Solid-State Circuits Conference (ISSCC 2005) CY FEB 06-10, 2005 CL San Francisco, CA SP IEEE DE amplifiers; bioelectric potentials; biomedical signal detection; biomedical signal processing; data compression; microelectrodes; microsensors; nervous system; time division multiplexing ID MICROELECTRODE ARRAYS; CORTEX AB A 256-site, fully implantable, 3-D neural recording microsystem has been developed. The microsystem incorporates four active neural probes with integrated circuitry for site selection, amplification, and multiplexing. The probes drive an embedded data-compression ASIC that successfully detects neural spikes in the presence of neural and circuit noise. The spike detection ASIC achieves a factor of 12 bandwidth reduction while preserving the key features of the action potential waveshape necessary for spike discrimination. This work extends the total number of neural channels that can be recorded across a transcutaneous inductively coupled wireless link from 25 to 312. When a spike is detected, this ASIC serially shifts the 5-bit amplitude and 5-bit address of the spike off of the chip over a single 2.5 Mb/s wired or wireless line. The spike detection ASIC occupies 6 mm(2) in 0.5 mu m features and consumes 2.6 mW while the entire microsystem consumes 5.4 mW of power from a XV supply. C1 Sandia Natl Labs, MEMS Device Technol Grp, Albuquerque, NM 87185 USA. Univ Michigan, Ctr Wireless Integrated MicroSyst, Ann Arbor, MI 48109 USA. RP Sandia Natl Labs, MEMS Device Technol Grp, POB 5800, Albuquerque, NM 87185 USA. EM rholsso@sandia.gov; wise@umich.edu NR 18 TC 123 Z9 126 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9200 EI 1558-173X J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD DEC PY 2005 VL 40 IS 12 BP 2796 EP 2804 DI 10.1109/JSSC.2005.858479 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 989GV UT WOS:000233661800043 ER PT J AU Hernandez, VJ Mendez, AJ Bennett, CV Gagliardi, RM Lennon, WJ AF Hernandez, VJ Mendez, AJ Bennett, CV Gagliardi, RM Lennon, WJ TI Bit-error-rate analysis of a 16-user Gigabit Ethernet optical-CDMA (O-CDMA) technology demonstrator using wavelength/time codes SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE access codes; code-division multiaccess; codes; encoding; multiaccess communication; optical fiber communication ID NETWORK AB This letter describes a technology demonstrator for an incoherent optical code-division multiple-access scheme based on wavelength/time codes. The system supports 16 users operating at 1.25 Gsymbols/s/user while maintaining bit-error rate (BER) < 10(-11) for the correctly decoded signal. Experiments support previous simulations which show that coherent beat noise, occurring between the signal and multiple access interference, ultimately limits system performance. C1 Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Mendez R&D Associates, El Segundo, CA 90245 USA. Univ So Calif, Dept Elect Engn, Syst Div, Los Angeles, CA 90089 USA. RP Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA. EM vjhernandez@ucdavis.edu; MendezRDA@aol.com; cvbennett@llnl.gov; bobgags@csi.use.edu; wjlennon@llnl.gov RI Bennett, Corey/C-2403-2009; Hernandez, Vincent/C-2522-2009 OI Bennett, Corey/0000-0003-4365-5739; NR 10 TC 18 Z9 18 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1041-1135 EI 1941-0174 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 2005 VL 17 IS 12 BP 2784 EP 2786 DI 10.1109/LPT.2005.859486 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 988SM UT WOS:000233621000095 ER PT J AU Chowdhuri, P Pallem, C Demko, JA Gouge, MJ AF Chowdhuri, P Pallem, C Demko, JA Gouge, MJ TI Feasibility of electric power transmission by DC superconducting cables SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article DE DC superconducting cable; high-temperature superconductivity; power transmission lines ID THERMAL CONSIDERATIONS; SYSTEMS AB The electrical characteristics of dc superconducting cables of two power ratings were studied: 3 GW and 500 MW. Two designs were considered for each of the two power ratings. In the first design, the SUPPLY stream of the cryogen is surrounded by the high-voltage high-temperature superconductor cylinder. The RETURN stream of the cryogen is on the grounded side of the system. In the second design, both the SUPPLY and the RETURN streams of the cryogen are on the grounded side of the cable. Two electrical characteristics of these cables were studied: 1) fault currents and 2) current harmonics. It was concluded that neither the fault currents nor the current harmonics pose any problems in the operation of the dc superconducting cables. C1 Tennessee Technol Univ, Energy Syst Res Ctr, Cookeville, TN 38505 USA. Oak Ridge Natl Lab, Appl Superconduct Grp, Oak Ridge, TN 37831 USA. RP Chowdhuri, P (reprint author), Tennessee Technol Univ, Energy Syst Res Ctr, Cookeville, TN 38505 USA. EM pchowdhuri@tntech.edu; cpallem21@tntech.edu; demkoja@ornl.gov; gougemj@ornl.gov NR 15 TC 25 Z9 30 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD DEC PY 2005 VL 15 IS 4 BP 3917 EP 3926 DI 10.1109/TASC.2005.859046 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 992XP UT WOS:000233917600004 ER PT J AU Subramanian, H Ibey, BL Xu, WJ Wilson, MA Ericson, MN Cote, GL AF Subramanian, H Ibey, BL Xu, WJ Wilson, MA Ericson, MN Cote, GL TI Real-time separation of perfusion and oxygenation signals for an implantable sensor using adaptive filtering SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE adaptive filtering; autocorrelation; implant; Monte Carlo; oxygen saturation; pulse oximeter; transplant ID OPTICAL-PROPERTIES; MULTILAYERED TISSUES; BLOOD AB In this paper, an adaptive filtering algorithm to separate signals due to perfusion and oxygenation has been developed using an 810-nm source, in addition to 660-nm and 940-nm sources, as an internal reference due to its limited oxygen sensitivity. The newly developed, algorithm was tested using Monte Carlo simulated data to prove the effectiveness of the 810-nm reference and adaptive algorithm. Following the simulation, an in vitro model was developed to test the algorithm that used a blood flow through system wrapped with tissue. The system had the ability to isolate the effects of perfusion and oxygenation and the algorithm accurately captured the changes in these signals with reliable consistency. Using the serosal surface of the swine jejunum, in vivo data was also taken to analyze the algorithms response to fluctuating perfusion levels like that seen in hemorrhaging or failing transplants. The algorithm was able to extract the perfusion information from the oxygenation information in this in vivo study. Overall, it was shown that an adaptive filtering algorithm using an 810-nm reference has provided a means to separate oxygenation and perfusion. C1 Texas A&M Univ, Dept Biomed Engn, College Stn, TX 77843 USA. Univ Pittsburgh, Dept Surg, Pittsburgh, PA 15213 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Cote, GL (reprint author), Texas A&M Univ, Dept Biomed Engn, College Stn, TX 77843 USA. EM hariharan@tamu.edu; bli6339@tamu.edu; xuw@msx.upmc.edu; Mark.wilson5@med.va.gov; ericsonmn@ornl.gov; gcote@tamu.edu RI Ericson, Milton/H-9880-2016; OI Ericson, Milton/0000-0002-6628-4865; Subramanian, Hariharan/0000-0003-0126-2718 NR 19 TC 10 Z9 12 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9294 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD DEC PY 2005 VL 52 IS 12 BP 2016 EP 2023 DI 10.1109/TBME.2005.857667 PG 8 WC Engineering, Biomedical SC Engineering GA 994WU UT WOS:000234062700005 PM 16366225 ER PT J AU Carlsten, BE Roybal, WT Tallerico, PJ AF Carlsten, BE Roybal, WT Tallerico, PJ TI Modifications to harmonic current bunching of electron beams from RF cavities due to radial boundary conditions SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE electron beams; klystrons; microwave amplifiers; traveling-wave tubes AB Harmonic current bunching of an electron beam after it passes through a standing-wave RF cavity is well known, with analytic solutions in both the transversely infinite space-charge regime and the ballistic regime. The Wallander formula [1] is often used between these regimes for finite-sized beams, with pretty good accuracy. These formulas describe simple space-charge modes that are launched by the RF cavity, and assume a single space-charge reduction factor. However, upon close examination these formulas do not provide the complete story. Additional space-charge modes are introduced by the radial boundary conditions, and the actual total harmonic current is modified somewhat from the simple formulas, and includes beating effects between the different modes, even in the small-signal, or linear, regime. This beating leads to mode mixing and eventual damping, which also affects the long-term propagation of longitudinal space-charge waves in accelerator structures. 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. EM bcarlsten@lanl.gov NR 19 TC 13 Z9 17 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD DEC PY 2005 VL 52 IS 12 BP 2791 EP 2799 DI 10.1109/TED.2005.859653 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 989OA UT WOS:000233682200035 ER PT J AU Yeary, LW Moon, JW Love, LJ Thompson, JR Rawn, CJ Phelps, TJ AF Yeary, LW Moon, JW Love, LJ Thompson, JR Rawn, CJ Phelps, TJ TI Magnetic properties of biosynthesized magnetite nanoparticles SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article ID DISSIMILATORY REDUCTION; DEEP SUBSURFACE; IRON; BACTERIUM; MANGANESE; OXIDE AB Magnetic nanoparticles, which are unique because of both structural and functional elements, have various novel applications. The popularity and practicality of nanoparticle materials create a need for a synthesis method that produces quality particles in sizable quantities. This paper describes such a method, one that uses bacterial synthesis to create nanoparticles of magnetite. The thermophilic bacterial strain Thermoanaerobacter ethanolicus TOR-39 was incubated under anaerobic conditions at 65 degrees C for two weeks in aqueous solution containing Fe ions from a magnetite precursor (akaganeite). Magnetite particles formed outside of bacterial cells. We verified particle size and morphology by using dynamic light scattering, X-ray diffraction, and transmission electron microscopy. Average crystallite size was 45 urn. We characterized the magnetic properties by using a superconducting quantum interference device magnetometer; a saturation magnetization of 77 emu/g was observed at 5 K. These results are comparable to those for chemically synthesized magnetite nanoparticles. C1 Oak Ridge Natl Lab, Robot & Energet Syst Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Appl Environm Sci & Technol Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Diffract & Thermophys Properties Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Superconduct Grp, Oak Ridge, TN 37831 USA. RP Yeary, LW (reprint author), Oak Ridge Natl Lab, Robot & Energet Syst Grp, Oak Ridge, TN 37831 USA. RI Moon, Ji-Won/A-9186-2011; phelps, tommy/A-5244-2011 OI Moon, Ji-Won/0000-0001-7776-6889; NR 20 TC 22 Z9 23 U1 2 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD DEC PY 2005 VL 41 IS 12 BP 4384 EP 4389 DI 10.1109/TMAG.2005.857482 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 993RS UT WOS:000233973200003 ER PT J AU Rodenbeck, CT Kim, SG Tu, WH Coutant, MR Hong, SP Li, MY Chang, K AF Rodenbeck, CT Kim, SG Tu, WH Coutant, MR Hong, SP Li, MY Chang, K TI Ultra-wideband low-cost phased-array radars SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE antenna arrays; monolithic microwave integrated circuits (MMICs); phased arrays; ultra-wideband radar ID POWER-AMPLIFIER; ANTENNA AB Emerging radar applications require phased arrays that can operate over wide bandwidths to support multiband/multifunction operation. In response to that need, this paper presents a cost-effective implementation for extremely wide-band phased-array radars. Two designs are demonstrated, one operating from 3 to 12 GHz and the other operating from 8 to 20 GHz. These designs incorporate ultra-wideband antipodal tapered slot antennas, a novel cross-polarization suppressed array architecture, piezoelectric true-time-delay phase shifters, and broad-band high-power monolithic amplifiers. The resulting systems provide target detection and beam steering over the complete operating bandwidths. These results exceed the state-of-the-art for phased-array radars in terms of bandwidth and cost and should have direct applications in the development of ultra-wideband and multifunction radar systems. C1 Texas A&M Univ, Dept Elect Engn, College Stn, TX 77843 USA. TriQuint Semicond, Richardson, TX 75080 USA. RP Rodenbeck, CT (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM ctroden@sandia.gov RI Rodenbeck, Christopher/A-8937-2009; Tu, Wen-Hua/B-9288-2009 NR 16 TC 47 Z9 48 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 2005 VL 53 IS 12 BP 3697 EP 3703 DI 10.1109/TMTT.2005.856668 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 992CE UT WOS:000233861100003 ER PT J AU Gorostiza, P Tombola, F Verdaguer, A Smith, SB Bustamante, C Isacoff, EY AF Gorostiza, P Tombola, F Verdaguer, A Smith, SB Bustamante, C Isacoff, EY TI Molecular handles for the mechanical manipulation of single-membrane proteins in living cells SO IEEE TRANSACTIONS ON NANOBIOSCIENCE LA English DT Article DE atomic force spectroscopy; living cells; patch clamp; selective molecular attachment; single-molecule force measurements ID FORCE; MOTOR; DNA; S4 AB We have developed a procedure to selectively biotinylate a specific membrane protein, enabling its attachment to external force probes and thus allowing its mechanical manipulation Within its native environment. Using potassium channels. as model membrane proteins in oocytes, we have found that Maleimide-PEG3400-biotin is the crosslinker with highest conjugation selectivity and accessibility to external probes. Neutravidin-coated beads Provide for directed attachment while avoiding nonspecific interactions with the cell. The technology was successfully tested by mechanical manipulation of biotinylated extracellular residues of channels in oocytes using an atomic force microscope under conditions which preserve function of the channels. Binding forces of similar to 80 pN at 100 nN/s were measured. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Ctr Catalysis & Surface Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Isacoff, EY (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 229 Stanley Hall, Berkeley, CA 94720 USA. EM pau@berkeley.edu; tombolaf@uclink.berkeley.edu; averdaguer@lbl.gov; steve@alice.berkeley.edu; carlos@alice.berkeley.edu; ehud@berkeley.edu RI Verdaguer, Albert/A-4303-2008; Tombola, Francesco/C-7311-2011; Gorostiza, Pau/Q-2544-2015 OI Verdaguer, Albert/0000-0002-4855-821X; Gorostiza, Pau/0000-0002-7268-5577 FU NIMH NIH HHS [R01 MH060711, R01 MH60711-02]; NINDS NIH HHS [R01 NS035549] NR 17 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1536-1241 J9 IEEE T NANOBIOSCI JI IEEE Trans. Nanobiosci. PD DEC PY 2005 VL 4 IS 4 BP 269 EP 276 DI 10.1109/TNB.2005.859552 PG 8 WC Biochemical Research Methods; Nanoscience & Nanotechnology SC Biochemistry & Molecular Biology; Science & Technology - Other Topics GA 990QB UT WOS:000233757200001 PM 16433292 ER PT J AU Sexton, FW AF Sexton, FW TI Conference comments by the general chairman SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Editorial Material C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sexton, FW (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2090 EP 2092 DI 10.1109/TNS.2005.864145 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000001 ER PT J AU Ferlet-Cavrois, V Paillet, P McMorrow, D Torres, A Gaillardin, M Melinger, JS Knudson, AR Campbell, AB Schwank, JR Vizkelethy, G Shaneyfelt, MR Hirose, K Faynot, O Jahan, C Tosti, L AF Ferlet-Cavrois, V Paillet, P McMorrow, D Torres, A Gaillardin, M Melinger, JS Knudson, AR Campbell, AB Schwank, JR Vizkelethy, G Shaneyfelt, MR Hirose, K Faynot, O Jahan, C Tosti, L TI Direct measurement of transient pulses induced by laser and heavy ion irradiation in deca-nanometer devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE collected charge; heavy ion; pulsed laser; SOI and bulk transistors; transient current ID SINGLE-EVENT TRANSIENTS; MICROELECTRONICS; TRANSISTORS; AVIONICS; UPSET AB This paper investigates the transient response of 50-nm gate length fully and partially depleted SOI and bulk devices to pulsed laser and heavy ion microbeam irradiations. The measured transient signals on 50-nm fully depleted devices are very short, and the collected charge is small compared to older 0.25-mu m generation SOI and bulk devices. We analyze in detail the influence of the SOI architecture (fully or partially depleted) on the pulse duration and the amount of bipolar amplification. For bulk devices, the doping engineering is shown to have large effects on the duration of the transient signals and on the charge collection efficiency. C1 CEA, DIF, F-91680 Bruyeres Le Chatel, France. IMEP ENSERG, F-38016 Grenoble 1, France. USN, Res Lab, Washington, DC 20375 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. CEA LETI, F-38054 Grenoble 9, France. RP Ferlet-Cavrois, V (reprint author), CEA, DIF, BP12, F-91680 Bruyeres Le Chatel, France. EM veronique.ferlet@cea.fr NR 24 TC 51 Z9 51 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2104 EP 2113 DI 10.1109/TNS.2005.860682 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000007 ER PT J AU Zhou, XJ Fleetwood, DM Felix, JA Gusev, EP D'Emic, C AF Zhou, XJ Fleetwood, DM Felix, JA Gusev, EP D'Emic, C TI Bias-temperature instabilities and radiation effects in MOS devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE high-kappa dielectrics; negative-bias temperature instability; oxide-trap charge; interface traps; MOS devices; radiation hardness assurance ID INTERFACE-TRAP FORMATION; GATE DIELECTRIC STACKS; SWITCHING OXIDE TRAPS; DOSE-RATE SENSITIVITY; NEGATIVE-BIAS; BORDER TRAPS; 1/F NOISE; TRANSISTORS; HYDROGEN; SIO2 AB We report the combined effects of irradiation and bias temperature stress (BTS) on MOS capacitors with HfO2 dielectrics. Irradiation is found to enhance BTS-induced degradation in these devices; significant differences in the amounts of enhancement are observed for different irradiation biases. Zero-bias or positive-bias irradiation followed by negative BTS (NBTS) leads to much worse degradation than either irradiation or NBTS alone. This is primarily due to the formation of dipoles during irradiation and the electrostatic repulsion of electrons from the oxide during NBTS. In an integrated circuit application, the worst-case response for these gate stacks will be pMOS transistors irradiated in their "off" states, and annealed in their "on" states. The effects of irradiation and BTS are also reported for Al2O3-based MOS capacitors with Al gates and SiO2-based MOS capacitors with NiSi gates for comparison with HfO2. Somewhat less sensitivity to combined irradiation and BTS is observed for the Al2O3-based devices, and significantly less sensitivity to combined effects is observed for the thermal oxides with NiSi gates. C1 Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. IBM Corp, TJ Watson Res Ctr, IBM Semicond Res & Dev Ctr, Yorktown Hts, NY 10598 USA. RP Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. EM xing.zhou@vanderbilt.edu; dan.fleetwood@vanderbilt.edu NR 44 TC 43 Z9 45 U1 0 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2231 EP 2238 DI 10.1109/TNS.2005.860667 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000026 ER PT J AU Chen, XJ Barnaby, HJ Pease, RL Schrimpf, RD Platteter, D Shaneyfelt, M Vermeire, B AF Chen, XJ Barnaby, HJ Pease, RL Schrimpf, RD Platteter, D Shaneyfelt, M Vermeire, B TI Estimation and verification of radiation induced N-ot and N-it energy distribution using combined bipolar and MOS characterization methods in gated bipolar devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE BJT; charge pumping; ELDRS; interface traps; TID ID INDUCED INTERFACE TRAPS; GAIN DEGRADATION; TRANSISTORS; CHARGE; MECHANISMS; OXIDES AB Complementary bipolar and MOS characterization techniques, specifically the gate sweep (GS) and sub-threshold sweep (SS), are used to estimate the radiation induced oxide charge (N-ot) and interface trap (N-it) buildup in gated bipolar test devices. The gate sweep and sub-threshold sweep data from recent TID testing of gated lateral PNP devices suggests an asymmetric energy distribution of interface traps after ionizing radiation exposure. Charge pumping (CP) experiments were done on the test devices to estimate the energy distribution of interface traps induced by radiation. The CP results are used in this paper to confirm the analytical findings from the GS and SS techniques and solidify the use of the complementary method as a simple way of determining radiation induced interface trap distribution in gated bipolar devices. C1 Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. RLP Res, Los Lunas, NM 87031 USA. Vanderbilt Univ, Nashville, TN 37232 USA. NAVSEA Crane, Crane, IN 47522 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Arizona State Univ, Wintech Programs, Tempe, AZ 85287 USA. RP Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. EM j.chen@asu.edu; hbarnaby@asu.edu; rpease@mrcmicroe.com; ron.schrimpf@vanderbilt.edu; platteter@atd.crane.navy.mil; shaneyfelt@sandia.gov; Bert.Vermeire@asu.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 22 TC 14 Z9 16 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2245 EP 2251 DI 10.1109/TNS.2005.860669 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000028 ER PT J AU Tsetseris, L Schrimpf, RD Fleetwood, DM Pease, RL Pantelides, ST AF Tsetseris, L Schrimpf, RD Fleetwood, DM Pease, RL Pantelides, ST TI Common origin for enhanced low-dose-rate sensitivity and bias temperature instability under negative bias SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE bipolar transistors; enhanced low-dose-rate sensitivity; interface phenomena; interface traps; radiation effects ID OXIDE-SEMICONDUCTOR DEVICES; INTERFACE-TRAP FORMATION; BIPOLAR-BASE OXIDES; CRYSTALLINE SILICON; SI-SIO2 INTERFACE; MICROSCOPIC STRUCTURE; HYDROGEN PASSIVATION; ELECTRIC-FIELDS; DIFFUSION; STATE AB Degradation due to irradiation is known to be associated with the presence of hydrogen in the bulk of the gate oxide, in bulk Si, and at the Si/SiO2 interface. Previous studies have shown that the migration of protons in the oxide for positive applied gate bias and their reactions at the interface can account for the time and dose-rate dependence of the degradation. Recent experiments, however, have shown that interfacial degradation can occur even in the presence of strong negative gate bias that prevents the arrival of protons at the interface from the oxide side. This result suggests that mechanisms in addition to proton drift in SiO2 can lead to radiation-induced interface-trap formation. Since previous work on modeling the enhanced low-dose-rate sensitivity (ELDRS) of irradiated bipolar devices was based on formation of an electrostatic barrier that hinders proton transport to the interface at high dose rates, this effect also must be examined in more detail. In this work we use results from first-principles calculations to demonstrate that hydrogen can also be released easily in bulk Si, and especially in the near interfacial area. This hydrogen moves readily to the interface under negative bias. Typical hydrogen precursors in Si are identified as H-dopant complexes. ELDRS shares thus a common origin with another critical reliability phenomenon, the negative bias-temperature instability. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. RLP Res Inc, Los Lunas, NM 87031 USA. Oak Ridge Natl Lab, Div Condensed Matter Sci, Oak Ridge, TN 37831 USA. RP Vanderbilt Univ, Dept Phys & Astron, 221 Kirkland Hall, Nashville, TN 37235 USA. EM leonidas.tsetseris@vanderbilt.edu; ron.schrimpf@vanderbilt.edu; dan.fleetwood@vanderbilt.edu; rpease@mrcmicroe.com; pantelides@vanderbilt.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 37 TC 40 Z9 42 U1 3 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2265 EP 2271 DI 10.1109/TNS.2005.860670 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000031 ER PT J AU Felix, JA Shaneyfelt, MR Dodd, PE Draper, BL Schwank, JR Dalton, SM AF Felix, JA Shaneyfelt, MR Dodd, PE Draper, BL Schwank, JR Dalton, SM TI Radiation-induced off-state leakage current in commercial power MOSFETs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE commercial-off-the-shelf (COTS); interface trap; leakage current; oxide trapped charge; power MOSFET; radiation effects; radiation hardened; radiation response; simulation; vertical double diffused power MOSFET (VDMOSFET) ID GAMMA-RAY; CHARGE; TRANSISTORS; GENERATION; VDMOSFET; DEVICES; SEGR; HUMP; DCIV AB The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO2) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Felix, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jafelix@sandia.gov NR 14 TC 16 Z9 18 U1 4 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2378 EP 2386 DI 10.1109/TNS.2005.860724 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000049 ER PT J AU Draper, BL Shaneyfelt, MR Young, RW Headley, TJ Dondero, R AF Draper, BL Shaneyfelt, MR Young, RW Headley, TJ Dondero, R TI Arsenic ion implant energy effects on CMOS gate oxide hardness SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE integrated circuit radiation effects; ion implantation; MOSFETs; radiation hardening ID SIO2 AB Under conditions that were predicted as "safe" by well-established TCAD packages, radiation hardness can still be signiticantly degraded by a few lucky arsenic ions reaching the gate oxide during self-aligned CMOS source/drain ion implantation. The most likely explanation is that both oxide traps and interface traps are created when ions penetrate and damage the gate oxide after channeling or traveling along polysilicon grain boundaries during the implantation process. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Draper, BL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM draperbl@sandia.gov NR 9 TC 3 Z9 3 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2387 EP 2391 DI 10.1109/TNS.2005.860727 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000050 ER PT J AU Morgan, K Caffrey, M Graham, P Johnson, E Pratt, B Wirthlin, M AF Morgan, K Caffrey, M Graham, P Johnson, E Pratt, B Wirthlin, M TI SEU-induced persistent error propagation in FPGAs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE dynamic testing; error propagation; FPGA; persistence; proton accelerator; radiation; simulator; single-event upset (SEU) AB This paper introduces a new way to characterize the dynamic single-event upset (SEU) cross section of an FPGA design in terms of its persistent and nonpersistent components. An SEU in the persistent cross section results in a permanent interruption of service until reset. An SEU in the nonpersistent cross section causes a temporary interruption of service. These cross sections have been measured for several designs using fault-injection and proton testing. Some FPGA applications may realize increased reliability at lower costs by focusing SEU mitigation on just the persistent cross section. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA. RP Morgan, K (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 16 TC 42 Z9 47 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2438 EP 2445 DI 10.1109/TNS.2005.860674 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000059 ER PT J AU Quinn, H Graham, P Krone, J Caffrey, M Rezgui, S AF Quinn, H Graham, P Krone, J Caffrey, M Rezgui, S TI Radiation-induced multi-bit upsets in SRAM-based FPGAs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE heavy ions; field programmable gate arrays; proton radiation effects AB This paper provides a methodology for estimating the proton and heavy ion static saturation cross-sections for multi-bit upsets (MBUs) in Xilinx field-programmable gate arrays and describes a methodology for determining MBUs' effects on triple-modular redundancy protected circuits. Experimental results are provided. C1 Los Alamos Natl Lab, ISR 3 Space Data Syst, Los Alamos, NM 87545 USA. Xilinx Corp, San Jose, CA 95124 USA. RP Quinn, H (reprint author), Los Alamos Natl Lab, ISR 3 Space Data Syst, Los Alamos, NM 87545 USA. EM hquinn@lanl.gov NR 11 TC 66 Z9 67 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2455 EP 2461 DI 10.1109/TNS.2005.860742 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000061 ER PT J AU Holbert, KE Sankaranarayanan, S McCready, SS AF Holbert, KE Sankaranarayanan, S McCready, SS TI Response of lead metaniobate acoustic emission sensors to gamma irradiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE DE gamma radiation; lead metaniobate; piezoelectric transducers; pulse reactor testing; radiation effects ID LITHIUM-NIOBATE; NEUTRON-IRRADIATION; PILE IRRADIATION; BARIUM TITANATE; CERAMICS; TEMPERATURES; BATIO3 AB Piezoelectric (PE) acoustic emission (AE) sensors were exposed to hundreds of kGy from Co-60 gamma rays. Recalibration of gamma-irradiated sensors showed a sensitivity decline of 8.4% per 100 kGy. Exposure of lead metaniobate disc specimens, the sensor ferroelectric material, to similar to 1 MGy revealed a capacitance increase and PE voltage (g(33)) coefficient decrease with gamma dose. The planar coupling factor (k(p)) and mechanical quality factor (Q(m)) exhibited small reductions. The AE sensors were also subjected to nuclear radiation from,a pulse reactor. C1 Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Holbert, KE (reprint author), Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. EM holbert@asu.edu RI Holbert, Keith/B-6518-2008; OI Holbert, Keith/0000-0002-2772-1954 NR 51 TC 5 Z9 5 U1 3 U2 16 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2583 EP 2590 DI 10.1109/TNS.2005.860708 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000080 ER PT J AU Schwank, JR Shaneyfelt, MR Baggio, J Dodd, PE Felix, JA Ferlet-Cavrois, V Paillet, P Lambert, D Sexton, FW Hash, GL Blackmore, E AF Schwank, JR Shaneyfelt, MR Baggio, J Dodd, PE Felix, JA Ferlet-Cavrois, V Paillet, P Lambert, D Sexton, FW Hash, GL Blackmore, E TI Effects of particle energy on proton-induced single-event latchup SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 42nd Annual Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 11-15, 2005 CL Seattle, WA SP IEEE AB The effect of proton energy on single-event latchup (SEL) in present-day SRAMs is investigated over a wide range of proton energies and temperature. SRAMs from five different vendors were irradiated at proton energies from 20 to 500 MeV and at temperatures of 25 degrees and 85 degrees C. For the SRAMs and radiation conditions examined in this work, proton energy SEL thresholds varied from as low as 20 MeV to as high as 490 MeV. To gain insight into the observed effects, the heavy-ion SEL linear energy transfer (LET) thresholds of the SRAMs were measured and compared to high-energy transport calculations of proton interactions with different materials. For some SRAMs that showed proton-induced SEL, the heavy-ion SEL threshold LET was as high as 25 MeV-cm(2)/mg. Proton interactions with Si cannot generate nuclear recoils with LETs this large. Our nuclear scattering calculations suggest that the nuclear recoils are generated by proton interactions with tungsten. Tungsten plugs are commonly used in most high-density ICs fabricated today, including SRAMs. These results demonstrate that for system applications where latchups cannot be tolerated, SEL hardness assurance testing should be performed at a proton energy at least as high as the highest proton energy present in the system environment. Moreover, the best procedure to ensure that ICs will be latchup free in proton environments may be to use a heavy-ion source with LETs > 40 MeV-cm(2)/mg. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. CEA, DIF, F-91680 Bruyeres Le Chatel, France. TRIUMF, Vancouver, BC V6T 2A3, Canada. RP Schwank, JR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM schwanjr@sandia.gov NR 13 TC 46 Z9 47 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2622 EP 2629 DI 10.1109/TNS.2005.860672 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 017LL UT WOS:000235695000086 ER PT J AU Tajima, H Kamae, T Madejski, G Mitani, I Nakazawa, K Tanaka, T Takahashi, T Watanabe, S Fukazawa, Y Ikagawa, T Kataoka, J Kokubun, M Makishima, K Terada, Y Nomachi, M Tashiro, M AF Tajima, H Kamae, T Madejski, G Mitani, I Nakazawa, K Tanaka, T Takahashi, T Watanabe, S Fukazawa, Y Ikagawa, T Kataoka, J Kokubun, M Makishima, K Terada, Y Nomachi, M Tashiro, M TI Design and performance of the soft gamma-ray detector for the NeXT mission SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE cadmium telluride (CdTe); Compton camera; gamma-ray astronomy detectors; polarimetry; silicon radiation detectors ID COMPTON TELESCOPE; CDTE DIODE; ENERGY; CAMERA; POLARIZATION; POLARIMETRY; ACTIVATION; SCATTERING; ASTRONOMY AB The soft gamma-ray detector (SGD) onboard the Japanese future high energy astrophysics mission (NeXT) is a Compton telescope with narrow field of view, which utilizes Compton kinematics to enhance its background rejection capabilities. It is realized as a hybrid semiconductor gamma-ray detector which consists of silicon and cadmium telluride (CdTe) detectors. It can detect photons in a wide energy band (0.05-1 MeV) at a background level of 5 x 10(-7) counts/s/cm(2) /keV; the silicon layers are required to improve the performance at a lower energy band (< 0.3 MeV). Excellent energy resolution is the key feature of the SGD, allowing it to achieve both high angular resolution and good background rejection capability. An additional capability of the SGD, its ability to measure gamma-ray polarization, opens up a new window to study properties of astronomical objects. We will present the development of key technologies to realize the SGD: high quality CdTe, low noise front-end application-specific integrated circuit, and bump bonding technology. Energy resolutions of 1.7 keV (full-width at half-maximum) for CdTe pixel detectors and 1.1 keV for Si strip detectors have been measured. We also present the validation of Monte Carlo simulation used to evaluate the performance of the SGD. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Tokyo, Bunkyo Ku, Tokyo 1130033, Japan. Hiroshima Univ, Hiroshima 7398526, Japan. Tokyo Inst Technol, Tokyo 1528551, Japan. RIKEN, Wako, Saitama 3510198, Japan. Osaka Univ, Osaka 5608532, Japan. Saitama Univ, Urawa, Saitama 3388570, Japan. RP Tajima, H (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RI Tashiro, Makoto/J-4562-2012; Terada, Yukikatsu/A-5879-2013 OI Terada, Yukikatsu/0000-0002-2359-1857 NR 37 TC 20 Z9 20 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2749 EP 2757 DI 10.1109/TNS.2005.862776 PN 2 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900006 ER PT J AU Yamaoka, K Ohno, M Terada, Y Hong, S Kotoku, J Okada, Y Tsutsui, A Endo, Y Abe, K Fukazawa, Y Hirakuri, S Hiruta, T Itoh, K Itoh, T Kamae, T Kawaharada, M Kawano, N Kawashima, K Kishishita, T Kitaguchi, T Kokubun, M Madejski, GM Makishima, K Mitani, T Miyawaki, R Murakami, T Murashima, MM Nakazawa, K Niko, H Nomachi, M Oonuki, K Sato, G Suzuki, M Takahashi, H Takahashi, I Takahashi, T Takeda, S Tamura, K Tanaka, T Tashiro, M Watanabe, S Yanagida, T Yonetoku, D AF Yamaoka, K Ohno, M Terada, Y Hong, S Kotoku, J Okada, Y Tsutsui, A Endo, Y Abe, K Fukazawa, Y Hirakuri, S Hiruta, T Itoh, K Itoh, T Kamae, T Kawaharada, M Kawano, N Kawashima, K Kishishita, T Kitaguchi, T Kokubun, M Madejski, GM Makishima, K Mitani, T Miyawaki, R Murakami, T Murashima, MM Nakazawa, K Niko, H Nomachi, M Oonuki, K Sato, G Suzuki, M Takahashi, H Takahashi, I Takahashi, T Takeda, S Tamura, K Tanaka, T Tashiro, M Watanabe, S Yanagida, T Yonetoku, D TI Development of the HXD-II wide-band all-sky monitor onboard Astro-E2 SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE astronomical satellites; hard X-ray detectors; scintillation detectors; X-ray astronomy ID X-RAY-DETECTOR; BURST; PERFORMANCE; SYSTEM AB The hard X-ray detector (HXD-II) is one of the three scientific instruments onboard Japanese X-ray astronomy satellite Astro-E2 scheduled to be launched in 2005. This mission is very unique in a point of having a lower background than any other past missions in the 10-600 keV range. In the HXD-II, the large and thick BGO crystals are used as active shields for particle and gamma-ray background to the main detector. They have a wide field of view of similar to 2 pi and a large effective area of 400 cm(2) even at 1 MeV. Hence, the BGO shields have been developed as a wide-band all-sky monitor (WAM) with a broadband coverage of 50-5000 keV. In this paper, overall design and performance of the HXD-II/WAM based on the results of preflight calibration tests carried out in June 2004 are described. By irradiating various radio isotopes with the WAM flight model, we verified that it had comparable capabilities with other gamma-ray burst detectors. C1 Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa 2298558, Japan. Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan. Saitama Univ, Dept Phys, Urawa, Saitama 3388570, Japan. Tokyo Inst Technol, Dept Phys, Tokyo 1528550, Japan. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Kanazawa Univ, Dept Phys, Kanazawa, Ishikawa 9201192, Japan. Osaka Univ, Nucl Studies Lab, Osaka 5600043, Japan. RP Yamaoka, K (reprint author), Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa 2298558, Japan. EM yamaoka@phys.aoyama.ac.jp RI Tashiro, Makoto/J-4562-2012; Terada, Yukikatsu/A-5879-2013; XRAY, SUZAKU/A-1808-2009; Yanagida, Takayuki/F-1814-2014 OI Terada, Yukikatsu/0000-0002-2359-1857; Yanagida, Takayuki/0000-0002-4298-5886 NR 23 TC 55 Z9 55 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2765 EP 2772 DI 10.1109/TNS.2005.862778 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900008 ER PT J AU Chytracek, R Dullmann, D Frank, M Girone, M Govi, G Moscicki, JT Papadopoulos, I Schmuecker, H Karr, K Malon, D Vaniachine, A Tanenbaum, W Xie, Z Barrass, T Cioffi, C AF Chytracek, R Dullmann, D Frank, M Girone, M Govi, G Moscicki, JT Papadopoulos, I Schmuecker, H Karr, K Malon, D Vaniachine, A Tanenbaum, W Xie, Z Barrass, T Cioffi, C TI POOL development status and production experience SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE data persistency; object streaming; plug-in architecture; relational database AB The pool of persistent objects for LHC (POOL) project, part of the large Hadron collider (LHC) computing grid (LCG), is now entering its third year of active development. POOL provides the baseline persistency framework for three LHC experiments. It is based on a strict component model, insulating experiment software from a variety of storage technologies. This paper gives a brief overview of the POOL architecture, its main design principles and the experience gained with integration into LHC experiment frameworks. It also presents recent developments in the POOL works areas of relational database abstraction and object storage into relational database management systems (RDBMS) systems. C1 CERN, CH-1211 Geneva 23, Switzerland. Argonne Natl Lab, Argonne, IL 60439 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ Oxford, Oxford OX1 3NP, England. RP Chytracek, R (reprint author), CERN, CH-1211 Geneva 23, Switzerland. RI Vanyashin, Aleksandr/H-7796-2013 OI Vanyashin, Aleksandr/0000-0002-0367-5666 NR 7 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2827 EP 2831 DI 10.1109/TNS.2005.860141 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900017 ER PT J AU Kaminski, J Kappler, S Ledermann, B Muller, T Ronan, M AF Kaminski, J Kappler, S Ledermann, B Muller, T Ronan, M TI Study of various anode pad readout geometries in a GEM-TPC SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE gas electron multipliers (GEMs); pad structure; spatial resolution; time projection chamber (TPC) AB The use of a time projection chamber (TPC) based on gas electron multipliers (GEMs) as a central tracker in particle-physics experiments is being studied by several groups. Compared to the conventional multi-wire readout this combination offers a number of advantages such as intrinsically suppressed ion feedback, high granularity and decoupling of gas amplification stage and readout geometry. The fast signal of GEMs and the reduction of the transverse diffusion in parallel magnetic fields give a good spatial resolution. However, for short drift distances and high magnetic fields, this may lead to signal sizes much narrower than the pad size and thus to a degradation of the spatial resolution. We have studied the use of different pad geometries to improve the performance of the detector in the small diffusion limit. C1 Univ Karlsruhe, Inst Expt Kernphys, D-7500 Karlsruhe, Germany. Rhein Westphal Tech Hsch, Aachen, Germany. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kaminski, J (reprint author), Univ Karlsruhe, Inst Expt Kernphys, Kaiserstr 12, D-7500 Karlsruhe, Germany. EM jochen.kaminski@iekp.fzk.de NR 12 TC 4 Z9 4 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2900 EP 2906 DI 10.1109/TNS.2005.862797 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900029 ER PT J AU Allspach, D Ambrose, D Binkley, M Bromberg, C Burkett, K Kephart, R Madrak, R Miao, T Mukherjee, A Roser, R Wagner, RL AF Allspach, D Ambrose, D Binkley, M Bromberg, C Burkett, K Kephart, R Madrak, R Miao, T Mukherjee, A Roser, R Wagner, RL TI Aging in the large CDF axial drift chamber SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE ablation; aging; alcohol; argon; ethane; gas; ionization chambers; polymerization; tracking; wire ID CHEMISTRY AB The Central Outer Tracker (COT) is a large axial drift chamber in the Collider Detector at Fermilab operating with a gas mixture that is 50/50 argon/ethane with an admixture of 1.7% isopropanol. In its first two years of operation the COT showed unexpected aging with the worst parts of the chamber experiencing a gain loss of similar to 50% for an accumulated charge of similar to 35 mC/cm. By monitoring the pulse height of hits on good tracks, it was possible to determine the gain as a function of time and location in the chamber. In addition, the currents of the high voltage supplies gave another monitor of chamber gain and its dependence on the charge deposition rate. The aging was worse on the exhaust end of the chamber consistent with polymer buildup as the gas flows through the chamber. The distribution in azimuth suggests that aging is enhanced at lower temperatures, but other factors such as gas flow patterns may be involved. Elemental and molecular analysis of the sense wires found a coating that is mostly carbon and hydrogen with a small amount of oxygen; no silicon or other contaminants were identified. High resolution electron microscope pictures of the wire surface show that the coating is smooth with small sub-micron nodules. In the course of working with the chamber gas system, we discovered a small amount of O-2 is enough to reverse the aging. Operating the chamber with similar to 100 ppm of O-2 reversed almost two years of gain loss in less than 10 days while accumulating <= 2 mC/cm. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Michigan State Univ, Dept Phys, E Lansing, MI 48824 USA. RP Allspach, D (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM allspach@fnal.gov; ambrose@fnal.gov; binkley@fnal.gov; bromberg@pa.msu.edu; burkett@fnal.gov; kephart@fnal.gov; madrak@fnal.gov; tmiao@fnal.gov; mulcherjee@fnal.gov; roser@fnal.gov; wagner@fnal.gov NR 6 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 2956 EP 2962 DI 10.1109/TNS.2005.862901 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900039 ER PT J AU Runkle, RC Mercier, TM Anderson, KK Carlson, DK AF Runkle, RC Mercier, TM Anderson, KK Carlson, DK TI Point source detection and characterization for vehicle radiation portal monitors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE matched filtering; point source detection; radiation portal monitoring AB Many international border crossings presently screen cargo for illicit nuclear material using radiation portal monitors (RPMs) that measure the gamma ray and/or neutron flux emitted by vehicles. The fact that many target sources have a point-like geometry can be exploited to detect subthreshold sources and filter out benign sources that frequently possess a distributed geometry. This report describes a two-step process, which has the potential to complement other alarm algorithms, for detecting and characterizing point sources. The first step applies a matched filter whereas step two uses a weighted nonlinear least squares method. In a base-case simulation, matched filtering detected a 250-cps source injected onto a white-noise background at a 95% detection probability and a 0.003 false alarm probability. For the same simulation, the maximum likelihood estimation technique performed well at source strengths of 250 and 400 cps. These simulations provided a best-case feasibility study for this technique, which will be extended to experimental data that possess false point-source signatures resulting from background shielding caused by vehicle design and cargo distribution. C1 Pacific NW Natl Lab, Radiat Detect & Nucl Sci Grp, Richland, WA 99352 USA. Pacific NW Natl Lab, Decis & Sensor Analyt Grp, Richland, WA 99352 USA. RP Runkle, RC (reprint author), Pacific NW Natl Lab, Radiat Detect & Nucl Sci Grp, Richland, WA 99352 USA. EM robert.runkle@pnl.gov; theresa.mercier@pnl.gov; kevin.anderson@pnl.gov; dcarlson@pnl.gov OI Anderson, Kevin/0000-0001-5613-5893 NR 8 TC 26 Z9 26 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 3020 EP 3025 DI 10.1109/TNS.2005.862910 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900048 ER PT J AU Hoover, AS Kippen, RM Sullivan, JP Rawool-Sullivan, MW Baird, W Sorensen, EB AF Hoover, AS Kippen, RM Sullivan, JP Rawool-Sullivan, MW Baird, W Sorensen, EB TI The LANL prototype Compton gamma-ray imager: Design and image reconstruction techniques SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE Compton; imaging; prototype; simulations ID ARMS-CONTROL; DETECTOR; TELESCOPE; EMISSION AB Today we face serious threats from radiological dispersion devices, improvised nuclear devices, and unsecured nuclear materials. Detectors which are currently used to detect and characterize these radioactive materials (or the radioactive materials within larger assemblies) suffer from large background rates. In addition, these detectors have only minimal ability to localize the position of the source without the use of mechanical collimators which reduce efficiency. Imaging detectors using the Compton scattering process have the potential to provide greatly improved sensitivity through their ability to reject off-source background by localizing the source. We are developing a prototype device using readily available detector systems to explore Compton imaging technology. Our aim is to build a proof-of-concept device to study the Compton technology and to benchmark simulation efforts that will guide development of larger, more efficient devices that would be needed for deployment in the field. Here we discuss the concept of our detector design and results from Monte Carlo simulations of our prototype detector. We present an extension of an imaging technique used for gamma-ray astronomy to near-field sources. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hoover, AS (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 23 TC 4 Z9 4 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 3047 EP 3053 DI 10.1109/TNS.2005.862818 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900052 ER PT J AU Pozzi, SA Oberer, RB Neal, JS AF Pozzi, SA Oberer, RB Neal, JS TI Analysis of the response of capture-gated organic scintillators SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE Monte Carlo methods; neutron detectors; spectroscopy ID NEUTRON; SPECTROMETER AB Recent efforts have been aimed at investigating neutron detectors based on the combined signal from capture-gated organic scintillators. We present a Monte Carlo approach that is based on the simulation of the neutron detector response on an event-by-event basis. Detection efficiency, scintillator pulse height, and time-to-capture are among the quantities that can be estimated by the Monte Carlo technique. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Y 12 Natl Secur Complex, BWXT, Oak Ridge, TN 37831 USA. RP Pozzi, SA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM pozzisa@ornl.gov; obererrb@y12.doe.gov; nealjs1@ornl.gov RI Neal, John/R-8203-2016 OI Neal, John/0000-0001-8337-5235 NR 13 TC 10 Z9 10 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 3141 EP 3146 DI 10.1109/TNS.2005.862924 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900068 ER PT J AU Shah, KS Glodo, J Higgins, W van Loef, EVD Moses, WW Derenzo, SE Weber, MJ AF Shah, KS Glodo, J Higgins, W van Loef, EVD Moses, WW Derenzo, SE Weber, MJ TI CeBr3 scintillators for gamma-ray spectroscopy SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE Ce3+; gamma-ray spectroscopy; radiation detectors; scintillators ID MECHANISMS AB In this paper, we report on a new scintillator, cerium bromide (CeBr3), for gamma-ray spectroscopy. Crystals of this scintillator have been grown using Bridgman process. In this material Ce3+ is an intrinsic constituent as well as a luminescence center for the scintillation process. Samples of CeBr3, showed high light output (similar to 68000 photons/MeV) and fast decay constant (similar to 17 ns). Furthermore, they exhibited excellent energy resolution for gamma-ray detection. For example, energy resolution of < 4% full width at half maximum (FWHM) has been achieved using this scintillator for 662 keV photons (Cs-137 source) at room temperature. High timing resolution (< 200 ps-FWHM) has been recorded with CeBr3-photomultiplier (PMT) and BaF2-PMT detectors operating in coincidence using 511 keV positron annihilation gamma-ray pairs. C1 Radiat Monitoring Devices Inc, Watertown, MA 02472 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Shah, KS (reprint author), Radiat Monitoring Devices Inc, Watertown, MA 02472 USA. EM kshah@rmdinc.com; wwmoses@lbl.gov NR 14 TC 61 Z9 64 U1 3 U2 15 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 3157 EP 3159 DI 10.1109/TNS.2005.860155 PN 2 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900071 ER PT J AU Protic, D Hull, EL Krings, T Vetter, K AF Protic, D Hull, EL Krings, T Vetter, K TI Large-volume Si(Li) orthogonal-strip detectors for Compton-effect-based instruments SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID SILICON; PERFORMANCE; STACK; GE AB Recent developments of large-area Si(Li) orthogonal-strip detectors have revealed their capability for applications in Compton-effect-based instruments. Some inherent advantages of silicon such as the dominance of Compton scattering in photon interactions and operation at room or somewhat lower temperature combined with the availability of large-volume Si(Li) detectors could stimulate the development of powerful Compton instruments. Several diodes 10 mm in thickness with a diameter of 102 nun were fabricated. Two 10 turn thick diodes were cut to form a 74 rum x 74 rum square with slightly rounded corners. The same position-sensitive structure, 32 strips with a pitch of 2 rum, was produced on the thin Li-diffused n-contact and boron-implanted p(+)-contact by means of photolithography and plasma etched grooves. The position-sensitive area of 64 mm x 64 mm is surrounded by a 5 mm wide guard-ring. One of these 10 mm thick Si(Li) orthogonal-strip detectors has been mounted in a cryostat prepared at Lawrence Livermore National Laboratory (LLNL). The detector will be extensively tested there with the goal of being integrated into the Compact Si+Ge Compton camera system consisting of this Si(Li) and a HPGe orthogonal-strip detector. C1 Forschungszentrum Julich, Inst Kernphys, D-52425 Julich, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Protic, D (reprint author), Forschungszentrum Julich, Inst Kernphys, Postfach 1913, D-52425 Julich, Germany. EM d.protic@fz-juelich.de NR 22 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 3181 EP 3185 DI 10.1109/TNS.2005.862930 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900076 ER PT J AU De Geronimo, G O'Connor, P AF De Geronimo, G O'Connor, P TI MOSFET optimization in deep submicron technology for charge amplifiers SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE charge amplifier; CMOS; MOSFET ID SOLID-STATE DETECTORS; LOW-NOISE; 1/F NOISE; FRONT-END; CMOS TECHNOLOGY; LHC EXPERIMENTS; X-RAY; DESIGN; PREAMPLIFIER; CIRCUITS AB The optimization of the input MOSFET for charge amplifiers in deep submicron technologies is discussed. After a review of the traditional approach, the impact of properly modeling the equivalent series noise and gate capacitance of the MOSFET is presented. It is shown that the enhanced MOSFET model, when compared to the classical, produces a different resolution estimate and input MOSFET optimization result. The minimum channel length and the maximum allocated power are not always the best choice in terms of resolution. Also, in an optimized front-end, the low frequency noise contribution to the Equivalent Noise Charge may depend on the time constant of the filter. As an example, results from the commercial TSMC 0.25 mu m CMOS technology are reported. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP De Geronimo, G (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. EM degeronimo@bnl.gov NR 32 TC 70 Z9 70 U1 3 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2005 VL 52 IS 6 BP 3223 EP 3232 DI 10.1109/TNS.2005.862938 PN 2 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 012WP UT WOS:000235371900083 ER PT J AU Moehs, DP Peters, J Sherman, J AF Moehs, DP Peters, J Sherman, J TI Negative hydrogen ion sources for accelerators SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Review DE accelerator; beam; beam transport; emittance; injector; ion; ion source; negative hydrogen; phase space; plasma; simulation ID SPALLATION NEUTRON SOURCE; SURFACE-PLASMA SOURCES; HIGH-INTENSITY; H-SOURCE; PROJECTIONAL EMITTANCE; SOURCE EXTRACTION; HIGH-BRIGHTNESS; ENERGY; TRANSPORT; BEAM AB A variety of H- ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H- ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H- production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. DESY, D-22607 Hamburg, Germany. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Moehs, DP (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM moehs@fnal.gov; jens.peters@desy.de; shermanjoe@aol.com NR 121 TC 38 Z9 40 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2005 VL 33 IS 6 BP 1786 EP 1798 DI 10.1109/TPS.2005.860067 PN 1 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 994XO UT WOS:000234064700005 ER PT J AU Grisham, LR AF Grisham, LR TI The operational phase of negative ion beam systems on JT-60U and LHD SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE fusion reactors; ion accelerators; ion beam applications; ion sources; magnetic confinement; negative ions; neutral beams ID LARGE HELICAL DEVICE; ENERGY-RESEARCH-INSTITUTE; APERTURE DISPLACEMENT TECHNIQUE; NBI SYSTEM; INJECTION SYSTEM; ALFVEN EIGENMODES; STEADY-STATE; PARTICLE EXPERIMENTS; PLASMA PERFORMANCE; TOKAMAK-60 UPGRADE AB This paper reviews the operational phase of the negative-ion-based neutral beam systems on the JT-60U tokamak in Naka, Japan and the large helical device (LHD) stellarator in Toki, Japan. These systems were the first high power negative ion beam systems to be deployed for any application, and thus represented large advances in the state of the art for negative ion sources and accelerators, especially since the ions used were hydrogen and deuterium, which have only a modest electron affinity. This paper reviews the systems, the principal problems encountered, and the improvements they engendered, as well as the progress of these systems to the present time. The role of neutral beams in fusion is also discussed, and some of the contributions of the negative ion systems to the physics programs of JT-60U and LHD are briefly reviewed. These systems have been central to the success of JT-60U and LHD, and the knowledge gained about their characteristics should provide a strong basis for the development of the next generation of negative-ion-based neutral beams for ITER and other large fusion devices. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08453 USA. RP Grisham, LR (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08453 USA. EM lgrisham@pppl.gov NR 79 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2005 VL 33 IS 6 BP 1814 EP 1831 DI 10.1109/TPS.2005.860083 PN 1 PG 18 WC Physics, Fluids & Plasmas SC Physics GA 994XO UT WOS:000234064700007 ER PT J AU Kwan, JW AF Kwan, JW TI High current ion sources and injectors for induction linacs in heavy ion fusion SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE alumino-silicate source; electrostatic quadrupole (ESQ); injector; ionizer; ion source; merging beamlets ID INERTIAL FUSION; POSITIVE-IONS; BEAM; STATE; EMITTANCE; SURFACE; ELISE AB Heavy ion beam driven inertial fusion requires short ion beam pulses with high current and high brightness. Depending on the beam current and the number of beams in the driver system, the injector can use a large diameter surface ionization source or merge an array of small beamlets from a plasma source. In this paper, we review the scaling laws that govern the injector design and the various ion source options including the contact ionizer, the aluminosilicate source, the multicusp plasma source, and the metal vapor vacuum arc (MEVVA) source. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kwan, JW (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM jwkwan@lbl.gov NR 43 TC 9 Z9 10 U1 2 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 EI 1939-9375 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2005 VL 33 IS 6 BP 1901 EP 1910 DI 10.1109/TPS.2005.860063 PN 1 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 994XO UT WOS:000234064700011 ER PT J AU Brown, I Oks, E AF Brown, I Oks, E TI Vacuum arc ion sources: Recent developments and Applications SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE cathode spot; ion implantation; ion source; metal ion beam; vacuum arc ID CHARGE-STATE DISTRIBUTIONS; CATHODE SPOT; PLASMA SOURCE; METAL PLASMA; BEAM; IMPLANTATION; EMISSION; IONIZATION; MECHANISM; DISCHARGE AB The vacuum arc ion source has evolved over the past 20 years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface modification. Another important use is for injection of high current beams of heavy metal ions into the front ends of particle accelerators, and much excellent work has been carried out in recent years in optimizing the source for reliable accelerator application. The source also provides a valuable tool for the investigation of the fundamental plasma physics of vacuum arc plasma discharges. As the use of the source has grown and diversified, at the same time, the ion source performance and operational characteristics have been improved in a variety of different ways also. Here we review the growth and status of vacuum arc ion sources around the world and summarize some of the applications for which the sources have been used. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. RP Brown, I (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM igbrown@lbl.gov RI Oks, Efim/A-9409-2014 OI Oks, Efim/0000-0002-9323-0686 NR 75 TC 21 Z9 24 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2005 VL 33 IS 6 BP 1931 EP 1943 DI 10.1109/TPS.2005.860088 PN 1 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 994XO UT WOS:000234064700013 ER PT J AU Pelletier, J Anders, A AF Pelletier, J Anders, A TI Plasma-blased ion implantation and deposition: A review of physics, technology, and applications SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Review DE ion-assisted thin film deposition; plasma-based ion implantation; pulsed bias ID AUSTENITIC STAINLESS-STEEL; CYCLOTRON-RESONANCE PLASMA; ULTRA-SHALLOW JUNCTIONS; DISCHARGE CATHODE MATERIALS; INNER SURFACE MODIFICATION; VOLTAGE PULSE-GENERATOR; SMALL CYLINDRICAL BORE; THIN-FILM DEPOSITION; AISI M2 STEEL; VACUUM-ARC AB After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modeling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction, and chemically inert phases and coatings, e.g., for engine components. PBII has become viable for the formation of shallow junctions and other applications in microelectronics. More recently, the rapidly growing field of biomaterial synthesis makes use of PBII and PBIID to alter surfaces of or produce coatings on surgical implants and other biomedical devices. With limitations, also nonconducting materials such as plastic sheets can be treated. The major interest in PBII processing originates from its flexibility in ion energy (from a few electron volts up to about 100 keV), and the capability to efficiently treat, or deposit on, large areas, and (within limits) to process nonflat, three-dimensional workpieces, including forming and modifying metastable phases and nanostructures. C1 CNRS, Ctr Rech Plasmas Mat Nanostruct, LPSC, F-38026 St Martin Dheres, France. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP CNRS, Ctr Rech Plasmas Mat Nanostruct, LPSC, F-38026 St Martin Dheres, France. EM jacques.pelletier@ujf-grenoble.fr; aanders@lbl.gov RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 205 TC 75 Z9 79 U1 7 U2 67 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 EI 1939-9375 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2005 VL 33 IS 6 BP 1944 EP 1959 DI 10.1109/TPS.2005.860079 PN 1 PG 16 WC Physics, Fluids & Plasmas SC Physics GA 994XO UT WOS:000234064700014 ER PT J AU Woodworth, JR Chalenski, D Sarkisov, GS Blickem, JR AF Woodworth, JR Chalenski, D Sarkisov, GS Blickem, JR TI 170-kV laser-triggered water switch experiments SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE laser triggering; plasma; pulsed power; water switches ID SPARK; BREAKDOWN AB We report the results of experiments using a small Q-switched Nd:YAG laser at 532 and 1064 nm to trigger a 170-kV pulse-charged water switch. 1-sigma jitters as low as +/- 1.7 ns were demonstrated; an order of magnitude improvement over the +/- 25-ns jitter of the switch in its self-breaking mode. At the optimum observed triggering wavelength of 532 nm, a 7-ns laser pulse gave better results than a 0.15-ns laser pulse. Time resolved optical diagnostics suggest a multistage triggering process in which the laser forms a string of point plasmas between the switch electrodes. These point plasmas expand, cool and merge, forming a vapor column between the electrodes that breaks down rapidly with low jitter. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Ktech Corp Inc, Albuquerque, NM 87123 USA. RP Woodworth, JR (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 25 TC 9 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2005 VL 33 IS 6 BP 2051 EP 2059 DI 10.1109/TPS.2005.860132 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 994XP UT WOS:000234064800012 ER PT J AU Kohwi-Shigematus, T Cai, S AF Kohwi-Shigematus, T Cai, S TI Chromatin looping mediated by genome organizer SATB1 in activated Th2 cells SO IMMUNOLOGY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0019-2805 J9 IMMUNOLOGY JI Immunology PD DEC PY 2005 VL 116 SU 1 BP 30 EP 30 PG 1 WC Immunology SC Immunology GA 987QC UT WOS:000233531400130 ER PT J AU Chain, PSG Comerci, DJ Tolmasky, ME Larimer, FW Malfatti, SA Vergez, LM Aguero, F Land, ML Ugalde, RA Garcia, E AF Chain, PSG Comerci, DJ Tolmasky, ME Larimer, FW Malfatti, SA Vergez, LM Aguero, F Land, ML Ugalde, RA Garcia, E TI Whole-genome analyses of speciation events in pathogenic Brucellae SO INFECTION AND IMMUNITY LA English DT Article ID YERSINIA-PESTIS; PLANT-PATHOGENS; INTRACELLULAR REPLICATION; CYCLIC BETA-1,2-GLUCAN; CAUSATIVE AGENT; MURINE MODEL; SIGMA-FACTOR; VIRULENCE; ABORTUS; SEQUENCE AB Despite their high DNA identity and a proposal to group classical Brucella species as biovars of Brucella melitensis, the commonly recognized Brucella species can be distinguished by distinct biochemical and fatty acid characters, as well as by a marked host range (e.g., Brucella suis for swine, B. melitensis for sheep and goats, and Brucella abortus for cattle). Here we present the genome of B. abortus 2308, the virulent prototype biovar I strain, and its comparison to the two other human pathogenic Brucella species and to B. abortus field isolate 9-941. The global distribution of pseudogenes, deletions, and insertions supports previous indications that B. abortus and B. melitensis share a common ancestor that diverged from B. suis. With the exception of a dozen genes, the genetic complements of both B. abortus strains are identical, whereas the three species differ in gene content and pseudogenes. The pattern of species-specific gene inactivations affecting transcriptional regulators and outer membrane proteins suggests that these inactivations may play an important role in the establishment of host specificity and may have been a primary driver of speciation in the genus Brucella. Despite being nonmotile, the brucellae contain flagellum gene clusters and display species-specific flagellar gene inactivations, which lead to the putative generation of different versions of flagellum-derived structures and may contribute to differences in host specificity and virulence. Metabolic changes such as the lack of complete metabolic pathways for the synthesis of numerous compounds (e.g., glycogen, biotin, NAD, and choline) are consistent with adaptation of brucellae to an intracellular life-style. C1 Lawrence Livermore Natl Lab, Biosci Directorate, Livermore, CA 94551 USA. Univ Nacl Gen Martin, IIB, INTECH, CONICET, Buenos Aires, DF, Argentina. Calif State Univ Fullerton, Dept Biol Sci, Fullerton, CA 92834 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Garcia, E (reprint author), 7000 E Ave L-441, Livermore, CA 94551 USA. EM garcia12@llnl.gov RI Land, Miriam/A-6200-2011; chain, patrick/B-9777-2013; OI Land, Miriam/0000-0001-7102-0031; Aguero, Fernan/0000-0003-1331-5741; Comerci, Diego J./0000-0003-1949-4226 NR 49 TC 108 Z9 605 U1 1 U2 10 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD DEC PY 2005 VL 73 IS 12 BP 8353 EP 8361 DI 10.1128/IAI.73.12.8353-8361.2005 PG 9 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 986WK UT WOS:000233480200066 PM 16299333 ER PT J AU Bollen, J de Sompel, HV Smith, JA Luce, R AF Bollen, J de Sompel, HV Smith, JA Luce, R TI Toward alternative metrics of journal impact: A comparison of download and citation data SO INFORMATION PROCESSING & MANAGEMENT LA English DT Article DE usage analysis; digital libraries; journal impact ranking; impact metrics; social network analysis ID ASTROPHYSICS DATA SYSTEM; DIGITAL LIBRARY; RESEARCHERS; PATTERNS; NONSENSE; SENSE AB We generated networks of journal relationships from citation and download data, and determined journal impact rankings from these networks using a set of social network centrality metrics. The resulting journal impact rankings were compared to the ISI IF. Results indicate that, although social network metrics and ISI IF rankings deviate moderately for citation-based journal networks, they differ considerably for journal networks derived from download data. We believe the results represent a unique aspect of general journal impact that is not captured by the ISI IF. These results furthermore raise questions regarding the validity of the ISI IF as the sole assessment of journal impact, and suggest the possibility of devising impact metrics based on usage information in general. (c) 2005 Elsevier Ltd. All rights reserved. C1 Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. Los Alamos Natl Lab, Res Lib, Los Alamos, NM 87554 USA. RP Bollen, J (reprint author), Old Dominion Univ, Dept Comp Sci, 4700 Elkhorn Ave, Norfolk, VA 23529 USA. EM jbolien@lanl.gov OI Van de Sompel, Herbert/0000-0002-0715-6126 NR 55 TC 96 Z9 96 U1 6 U2 53 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4573 J9 INFORM PROCESS MANAG JI Inf. Process. Manage. PD DEC PY 2005 VL 41 IS 6 BP 1419 EP 1440 DI 10.1016/j.ipm.2005.03.024 PG 22 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA 956XE UT WOS:000231332600009 ER PT J AU Liu, XM Bollen, J Nelson, ML Van de Sompel, H AF Liu, XM Bollen, J Nelson, ML Van de Sompel, H TI Co-authorship networks in the digital library research community SO INFORMATION PROCESSING & MANAGEMENT LA English DT Article DE digital library; AuthorRank; social network analysis; co-authorship AB The field of digital libraries (DLs) coalesced in 1994: the first digital library conferences were held that year, awareness of the World Wide Web was accelerating, and the National Science Foundation awarded $24 Million (US) for the Digital Library Initiative (DLI). In this paper we examine the state of the DL domain after a decade of activity by applying social network analysis to the co-authorship network of the past ACM, IEEE, and joint ACM/IEEE digital library conferences. We base our analysis on a common binary undirectional network model to represent the co-authorship network, and from it we extract several established network measures. We also introduce a weighted directional network model to represent the co-authorship network, for which we define AuthorRank as an indicator of the impact of an individual author in the network. The results are validated against conference program committee members in the same period. The results show clear advantages of PageRank and AuthorRank over degree, closeness and betweenness centrality metrics. We also investigate the amount and nature of international participation in Joint Conference on Digital Libraries (JCDL). (c) 2005 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Res Lib, Los Alamos, NM 87545 USA. Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. RP Los Alamos Natl Lab, Res Lib, POB 1663, Los Alamos, NM 87545 USA. EM liu_x@lanl.gov OI Van de Sompel, Herbert/0000-0002-0715-6126; Nelson, Michael/0000-0003-3749-8116 NR 35 TC 220 Z9 241 U1 10 U2 128 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0306-4573 EI 1873-5371 J9 INFORM PROCESS MANAG JI Inf. Process. Manage. PD DEC PY 2005 VL 41 IS 6 BP 1462 EP 1480 DI 10.1016/j.ipm.2005.03.012 PG 19 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA 956XE UT WOS:000231332600011 ER PT J AU Angielczyk, KD Parham, JE AF Angielczyk, KD Parham, JE TI Geometric morphometric analysis of plastron shape in the western pond turtle (Emys marmorata): Implications for conservation and paleontology SO INTEGRATIVE AND COMPARATIVE BIOLOGY LA English DT Meeting Abstract CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 04-08, 2006 CL Orlando, FL C1 Calif Acad Sci, Joint Genome Inst, San Francisco, CA 94118 USA. EM kangielczyk@calacademy.org NR 0 TC 2 Z9 2 U1 1 U2 3 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1540-7063 J9 INTEGR COMP BIOL JI Integr. Comp. Biol. PD DEC PY 2005 VL 45 IS 6 BP 957 EP 957 PG 1 WC Zoology SC Zoology GA 012KH UT WOS:000235337600013 ER PT J AU Colbourne, JK Lindquist, E Bauer, D Brokstein, P Thomas, WK Andrews, J AF Colbourne, JK Lindquist, E Bauer, D Brokstein, P Thomas, WK Andrews, J TI Gene discovery in Daphnia by expressed sequence tag sequencing SO INTEGRATIVE AND COMPARATIVE BIOLOGY LA English DT Meeting Abstract CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 04-08, 2006 CL Orlando, FL C1 Indiana Univ, Bloomington, IN 47405 USA. US DOE, Washington, DC 20585 USA. Univ New Hampshire, Durham, NH 03824 USA. EM jcolbour@cgb.indiana.edu RI Colbourne, John/L-7748-2014 OI Colbourne, John/0000-0002-6966-2972 NR 0 TC 4 Z9 4 U1 0 U2 2 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1540-7063 J9 INTEGR COMP BIOL JI Integr. Comp. Biol. PD DEC PY 2005 VL 45 IS 6 BP 979 EP 979 PG 1 WC Zoology SC Zoology GA 012KH UT WOS:000235337600099 ER PT J AU Kaiser, A Klok, CJ Socha, J Lee, WK Fezzaa, K Quinlan, MC Harrison, JF AF Kaiser, A Klok, CJ Socha, J Lee, WK Fezzaa, K Quinlan, MC Harrison, JF TI Structure, function and allometry of the tracheal system of Darkling Beetles (Tenebrionidae) SO INTEGRATIVE AND COMPARATIVE BIOLOGY LA English DT Meeting Abstract CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 04-08, 2006 CL Orlando, FL C1 Midwestern Univ, Glendale, IL USA. Arizona State Univ, Tempe, AZ USA. Argonne Natl Lab, Argonne, IL 60439 USA. EM akaise@midwestern.edu NR 0 TC 1 Z9 1 U1 0 U2 1 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1540-7063 J9 INTEGR COMP BIOL JI Integr. Comp. Biol. PD DEC PY 2005 VL 45 IS 6 BP 1022 EP 1022 PG 1 WC Zoology SC Zoology GA 012KH UT WOS:000235337600273 ER PT J AU Klok, CJ Kaiser, A McKinley, B Rascon, B Henry, J Lee, WK Socha, J Harrison, JF AF Klok, CJ Kaiser, A McKinley, B Rascon, B Henry, J Lee, WK Socha, J Harrison, JF TI Plastic and evolutionary responses of body size and tracheal dimensions to atmospheric oxygen concentration in fruitflies SO INTEGRATIVE AND COMPARATIVE BIOLOGY LA English DT Meeting Abstract CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 04-08, 2006 CL Orlando, FL C1 Arizona State Univ, Tempe, AZ USA. Midwestern Univ, Downers Grove, IL 60515 USA. Argonne Natl Lab, Argonne, IL 60439 USA. EM cjklok@asu.edu NR 0 TC 1 Z9 1 U1 0 U2 0 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1540-7063 J9 INTEGR COMP BIOL JI Integr. Comp. Biol. PD DEC PY 2005 VL 45 IS 6 BP 1027 EP 1027 PG 1 WC Zoology SC Zoology GA 012KH UT WOS:000235337600292 ER PT J AU Socha, JJ Harrison, JF Lee, WK Westneat, MW AF Socha, JJ Harrison, JF Lee, WK Westneat, MW TI Tubes squeeze and the air flows out: Correlated patterns of CO2 emission and tracheal compression in the beetle, Platynus decentis SO INTEGRATIVE AND COMPARATIVE BIOLOGY LA English DT Meeting Abstract CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 04-08, 2006 CL Orlando, FL C1 Argonne Natl Lab, Argonne, IL 60439 USA. Arizona State Univ, Tempe, AZ 85287 USA. EM jjsocha@midway.uchicago.edu NR 0 TC 2 Z9 2 U1 0 U2 1 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1540-7063 J9 INTEGR COMP BIOL JI Integr. Comp. Biol. PD DEC PY 2005 VL 45 IS 6 BP 1074 EP 1074 PG 1 WC Zoology SC Zoology GA 012KH UT WOS:000235337600480 ER EF