5,052 research outputs found

    The ortho-para H2 distribution on Uranus: Constraints from the collision-induced 3-0 dipole band and 4-0 S(0) and S(1) quadrupole line profiles

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    Recent high quality spectral observations have allowed the derivation of constraints on the atmospheric structure of Uranus. The present analysis, which is based on the detailed modeling of a broadband geometric albedo spectrum and high resolution observations of the H2 4-0 quadrupole and 6818.9-A CH4 features, yields (1) a family of models which parameterize an upper tropospheric haze layer, (2) a lower, optically infinite cloud at a given pressure level, (3) the cloud-level methane molar fraction, and (4) the mean ortho/para ratio in the visible atmosphere. The single scattering albedo of atmospheric aerosols exhibits a steep darkening between 5890 and 6040 A

    Muon-spin-rotation measurements of the penetration depth in Li_2Pd_3B

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    Measurements of the magnetic field penetration depth λ\lambda in the ternary boride superconductor Li2_2Pd3_3B (Tc≃7.3T_c\simeq7.3 K) have been carried out by means of muon-spin rotation (μ\muSR). The absolute values of λ\lambda, the Ginzburg-Landau parameter κ\kappa, and the first Hc1H_{c1} and the second Hc2H_{c2} critical fields at T=0 obtained from μ\muSR were found to be λ(0)=252(2)\lambda(0)=252(2) nm, κ(0)=27(1)\kappa(0)=27(1), μ0Hc1(0)=9.5(1)\mu_0H_{c1}(0)=9.5(1) mT, and μ0Hc2(0)=3.66(8)\mu_0H_{c2}(0)=3.66(8) T, respectively. The zero-temperature value of the superconducting gap Δ0=\Delta_0=1.31(3) meV was found, corresponding to the ratio 2Δ0/kBTc=4.0(1)2\Delta_0/k_BT_c=4.0(1). At low temperatures λ(T)\lambda(T) saturates and becomes constant below T≃0.2TcT\simeq 0.2T_c, in agreement with what is expected for s-wave BCS superconductors. Our results suggest that Li2_2Pd3_3B is a s-wave BCS superconductor with the only one isotropic energy gap.Comment: 6 pages, 7 figure

    Constrained by managerialism : caring as participation in the voluntary social services

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    The data in this study show that care is a connective process, underlying and motivating participation and as a force that compels involvement in the lives of others, care is at least a micro-participative process. Care or affinity not only persisted in the face of opposition, but it was also used by workers as a counter discourse and set of practices with which to resist the erosion of worker participation and open up less autonomized practices and ways of connecting with fellow staff, clients and the communities they served. The data suggest that while managerialism and taylorised practice models may remove or reduce opportunities for worker participation, care is a theme or storyline that gave workers other ways to understand their work and why they did it, as well as ways they were prepared to resist managerial priorities and directives, including the erosion of various kinds of direct and indirect participation. The degree of resistance possible, even in the highly technocratic worksite in Australia, shows that cracks and fissures exist within managerialism

    Magnetic field distribution and characteristic fields of the vortex lattice for a clean superconducting niobium sample in an external field applied along a three-fold axis

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    The field distribution in the vortex lattice of a pure niobium single crystal with an external field applied along a three-fold axis has been investigated by the transverse-field muon-spin-rotation (TF-μ\muSR) technique over a wide range of temperatures and fields. The experimental data have been analyzed with the Delrieu's solution for the form factor supplemented by phenomenological formulas for the parameters. This has enabled us to experimentally establish the temperatures and fields for the Delrieu's, Ginzburg-Landau's, and Klein's regions of the vortex lattice. Using the numerical solution of the quasiclassical Eilenberger's equation the experimental results have been reasonably understood. They should apply to all clean BCS superconductors. The analytical Delrieu's model supplemented by phenomenological formulas for its parameters is found to be reliable for analyzing TF-μ\muSR experimental data for a substantial part of the mixed phase. The Abrikosov's limit is contained in it.Comment: 12 pages, 15 figure
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