1,057 research outputs found

    Spatial Structures in a Generalized Ginzburg-Landau Free Energy

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    Searching for characteristic signatures of a higher order phase transition (specifically of order three or four), we have calculated the spatial profiles and the energies of a spatially varying order parameter in one dimension. In the case of a pthp^{th} order phase transition to a superconducting ground state, the free energy density depends on temperature as apa^p, where a=ao(1T/Tc)a = a_o(1-T/T_c) is the reduced temperature. The energy of a domain wall between two degenerate ground states is ϵpap1/2\epsilon_p \simeq a^{p-1/2}. We have also investigated the effects of a supercurrent in a narrow wire. These effects are limited by a critical current which has a temperature dependence Jc(T)a(2p1)/2J_c(T) \simeq a^{(2p-1)/2}. The phase slip center profiles and their energies are also calculated. Given the suggestion that the superconducting transtion in \bkbox, for x=0.4x = 0.4, may be of order four, these predictions have relevance for future experiments.Comment: 7 pages, 5 figure

    Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate

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    <p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>and [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr<sup>III</sup>(HIDA)(IDA)(H<sub>2</sub>O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO<sub>4</sub><sup>-</sup>] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr<sup>III</sup>(IDA)(Val)(H<sub>2</sub>O)<sub>2</sub>] and [Cr<sup>III</sup>(IDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>, <it>k</it><sub>3 </sub>(1.82 × 10<sup>-3 </sup>s<sup>-1</sup>), is greater than the value of <it>k</it><sub>1 </sub>(1.22 × 10<sup>-3 </sup>s<sup>-1</sup>) for the oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>at 45.0°C and <it>I </it>= 0.20 mol dm<sup>-3</sup>. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO<sub>4</sub><sup>- </sup>to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>and [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>, <it>k</it><sub>3</sub>, is greater than the value of <it>k</it><sub>1 </sub>for the oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p

    Religious faith and psychosocial adaptation among stroke patients in Kuwait: A mixed method study

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Springer Science+Business Media.Religious faith is central to life for Muslim patients in Kuwait, so it may influence adaptation and rehabilitation. This study explored quantitative associations among religious faith, self-efficacy, and life satisfaction in 40 female stroke patients and explored the influence of religion within stroke rehabilitation through qualitative interviews with 12 health professionals. The quantitative measure of religious faith did not relate to life satisfaction or self-efficacy in stroke patients. However, the health professionals described religious coping as influencing adaptation post-stroke. Fatalistic beliefs were thought to have mixed influences on rehabilitation. Measuring religious faith among Muslims through a standardized scale is debated. The qualitative accounts suggest that religious beliefs need to be acknowledged in stroke rehabilitation in Kuwait

    Triggers for displaced decays of long-lived neutral particles in the ATLAS detector

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    A set of three dedicated triggers designed to detect long-lived neutral particles decaying throughout the ATLAS detector to a pair of hadronic jets is described. The efficiencies of the triggers for selecting displaced decays as a function of the decay position are presented for simulated events. The effect of pile-up interactions on the trigger efficiencies and the dependence of the trigger rate on instantaneous luminosity during the 2012 data-taking period at the LHC are discussedFil: Aad, G.. Albert Ludwigs Universität; AlemaniaFil: Abajyan, T.. Universitaet Bonn; AlemaniaFil: Abbott, B.. University of Oklahoma; Estados UnidosFil: Abdallah, J.. Universitat Autònoma de Barcelona; EspañaFil: Abdel Khalek, S.. Universite Paris Sud; FranciaFil: Alconada Verzini, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Alonso, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Anduaga, Xabier Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Dova, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: González Silva, María Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Monticelli, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Otero y Garzon, Gustavo Javier. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piegaia, Ricardo Nestor. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romeo, Gaston Leonardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tripiana, Martin Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Zhuang, X.. Ludwig Maximilians Universitat; AlemaniaFil: Zhuravlov, V.. Max-Planck Institut für Physik; AlemaniaFil: Zieminska, D.. Indiana University; Estados UnidosFil: Zimin, N. I.. Joint Institute for Nuclear Research; RusiaFil: Zimmermann, R.. Universitaet Bonn; AlemaniaFil: Zimmermann, S.. Universitaet Bonn; AlemaniaFil: Zimmermann, S.. Albert Ludwigs Universität; AlemaniaFil: Ziolkowski, M.. Universität Siegen; AlemaniaFil: Zitoun, R.. Université de Savoie; FranciaFil: Živković, L.. Columbia University; Estados UnidosFil: Zmouchko, V. V.. State Research Center Institute for High Energy Physics; RusiaFil: Zobernig, G.. University of Wisconsin; Estados UnidosFil: Zoccoli, A.. Università di Bologna; ItaliaFil: zur Nedden, M.. Humboldt University; AlemaniaFil: Zutshi, V.. Northern Illinois University; Estados Unido

    Measurement of the parity-violating asymmetry parameter αb and the helicity amplitudes for the decay Λ0b→J/ψ+Λ0 with the ATLAS detector

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    A measurement of the parity-violating decay asymmetry parameter, αb, and the helicity amplitudes for the decay Λb0→J/ψ(μ+μ-)Λ0(pπ-) is reported. The analysis is based on 1400 Λb0 and Λ¯b0 baryons selected in 4.6  fb-1 of proton-proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the Λb0 and Λ¯b0 samples under the assumption of CP conservation, the value of αb is measured to be 0.30±0.16(stat)±0.06(syst). This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.Fil: F. Monticelli.Fil: Atlas Collaboration

    Measurement of the production of a W boson in association with a charm quark in pp collisions at sqrt(s)=7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb^-1 of pp collision data at sqrt(s)=7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96 +0.26 -0.30 at Q^2=1.9 GeV^2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio sigma(W^+ + bar{c})/sigma(W^- + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s-bar{s} quark asymmetry.Fil: ATLAS Collaboration, G. AAd, F. Monticelli, et al. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Cern - European Organization For Nuclear Research; Suiz

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at root s = 8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/Rc = 950 GeV for a cut-off scale times radius (ΛRc) of approximately 30.G. Aad … P. Jackson … L. Lee … A. Petridis … N. Soni ... M. White ... et al. (The ATLAS Collaboration

    Measurements of the nuclear modification factor for jets in Pb+Pb collisions at root sNN =2.76 TeV with the ATLAS detector

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    Measurements of inclusive jet production are performed in pp and Pb+Pb collisions at √(s)NN=2.76  TeV with the ATLAS detector at the LHC, corresponding to integrated luminosities of 4.0 and 0.14  nb(-1), respectively. The jets are identified with the anti-k(t) algorithm with R=0.4, and the spectra are measured over the kinematic range of jet transverse momentum 32<p(T)<500  GeV and absolute rapidity |y|<2.1 and as a function of collision centrality. The nuclear modification factor R(AA) is evaluated, and jets are found to be suppressed by approximately a factor of 2 in central collisions compared to pp collisions. The R(AA) shows a slight increase with p(T) and no significant variation with rapidity.G. Aad … P. Jackson … L. Lee … A. Petridis … N. Soni ... M. White ... et al. (The ATLAS Collaboration

    Search for scalar charm quark pair production in pp collisions at root s =8 TeV with the ATLAS detector

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    The results of a dedicated search for pair production of scalar partners of charm quarks are reported. The search is based on an integrated luminosity of 20.3  fb^{-1} of pp collisions at sqrt[s]=8  TeV recorded with the ATLAS detector at the LHC. The search is performed using events with large missing transverse momentum and at least two jets, where the two leading jets are each tagged as originating from c quarks. Events containing isolated electrons or muons are vetoed. In an R-parity-conserving minimal supersymmetric scenario in which a single scalar-charm state is kinematically accessible, and where it decays exclusively into a charm quark and a neutralino, 95% confidence-level upper limits are obtained in the scalar-charm-neutralino mass plane such that, for neutralino masses below 200 GeV, scalar-charm masses up to 490 GeV are excluded.G. Aad … P. Jackson … L. Lee … A. Petridis … N. Soni ... M. White ... et al. (The ATLAS Collaboration

    Measurement of differential J/psi production cross sections and forward-backward ratios in p + Pb collisions with the ATLAS detector

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    Measurements of differential cross sections for J/ψ production in p + Pb collisions at √sNN = 5.02 TeV at the CERN Large Hadron Collider with the ATLAS detector are presented. The data set used corresponds to an integrated luminosity of 28.1 nb⁻¹. The J/ψ mesons are reconstructed in the dimuon decay channel over the transverse momentum range 8 < pT < 30 GeV and over the center-of-mass rapidity range −2.87 < y ∗ < 1.94. Prompt J/ψ are separated from J/ψ resulting from b-hadron decays through an analysis of the distance between the J/ψ decay vertex and the event primary vertex. The differential cross section for production of nonprompt J/ψ is compared to a FONLL calculation that does not include nuclear effects. Forward-backward production ratios are presented and compared to theoretical predictions. These results complement previously published results by covering a region of higher transverse momentum and more central rapidity. They thus constrain the kinematic dependence of nuclear modifications of charmonium and b-quark production in p + Pb collisions.G. Aad ... P. Jackson ... L. Lee ... A. Petridis ... N. Soni ... M.J. White ... et al. (ATLAS Collaboration
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