695 research outputs found

    X-band scattering measurements of earth surfaces from an aircraft

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    Airborne equipment for measuring X band scattering of earth surface

    Flight tests of a radar scattering-coefficient measuring instrument. Part 1 - Summary

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    Flight tests of radar scattering coefficient measuring instrumen

    Evaluation Development and Use in Social Work Practice

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    Background: Social workers entering the profession typically receive little, if any, content or training on evaluation practice. This is, in part, due to limited course offerings outside of the typical courses in most schools of social work. In addition, practicing social workers who often serve in the role as field instructors have not fully embraced the use of research in practice, and tend to employ less rigorous evaluative methods.   Purpose: The purpose of this study was to explore the development and use of evaluation knowledge among social work practitioners who supervise social work students.   Setting: Not applicable.   Intervention: Not applicable.   Research Design: A mixed method, sequential research design within the context of an exploratory study was used to determine factors that facilitate evaluation, identify and prioritize evaluation competencies, and determine the extent to which evaluation constructs contribute to self efficacy, evaluation competency, evaluation influence, and leadership behaviors.   Data Collection and Analysis: A web-based survey was used followed by a participatory method that included the use of a web-based software to identify and prioritize activities that contribute to the development of evaluation knowledge and skill.   Findings: Results suggest social work education has a critical role in promoting evaluation practice, establishing evaluation practice competencies, and using evaluation results to inform policy and practice.   Keywords: social work practice, field education, evaluation practice, Council on Social Work Education (CSWE), Educational Policy, and Accreditation Standards (EPAS

    Observation of two new Ξb\Xi_b^- baryon resonances

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    Two structures are observed close to the kinematic threshold in the Ξb0π\Xi_b^0 \pi^- mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb1^{-1} recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content bdsbds are expected in this mass region: the spin-parity JP=12+J^P = \frac{1}{2}^+ and JP=32+J^P=\frac{3}{2}^+ states, denoted Ξb\Xi_b^{\prime -} and Ξb\Xi_b^{*-}. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Ξb)m(Ξb0)m(π)=3.653±0.018±0.006m(\Xi_b^{\prime -}) - m(\Xi_b^0) - m(\pi^{-}) = 3.653 \pm 0.018 \pm 0.006 MeV/c2/c^2, m(Ξb)m(Ξb0)m(π)=23.96±0.12±0.06m(\Xi_b^{*-}) - m(\Xi_b^0) - m(\pi^{-}) = 23.96 \pm 0.12 \pm 0.06 MeV/c2/c^2, Γ(Ξb)=1.65±0.31±0.10\Gamma(\Xi_b^{*-}) = 1.65 \pm 0.31 \pm 0.10 MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of Γ(Ξb)<0.08\Gamma(\Xi_b^{\prime -}) < 0.08 MeV at 95% confidence level. Relative production rates of these states are also reported.Comment: 17 pages, 2 figure

    Precision measurement of CPCP violation in Bs0J/ψK+KB_s^0 \to J/\psi K^+K^- decays

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    The time-dependent CPCP asymmetry in Bs0J/ψK+KB_s^0 \to J/\psi K^+K^- decays is measured using pppp collision data, corresponding to an integrated luminosity of 3.03.0fb1^{-1}, collected with the LHCb detector at centre-of-mass energies of 77 and 88TeV. In a sample of 96 000 Bs0J/ψK+KB_s^0 \to J/\psi K^+K^- decays, the CPCP-violating phase ϕs\phi_s is measured, as well as the decay widths ΓL\Gamma_{L} and ΓH\Gamma_{H} of the light and heavy mass eigenstates of the Bs0Bˉs0B_s^0-\bar{B}_s^0 system. The values obtained are ϕs=0.058±0.049±0.006\phi_s = -0.058 \pm 0.049 \pm 0.006 rad, Γs(ΓL+ΓH)/2=0.6603±0.0027±0.0015\Gamma_s \equiv (\Gamma_{L}+\Gamma_{H})/2 = 0.6603 \pm 0.0027 \pm 0.0015ps1^{-1}, andΔΓsΓLΓH=0.0805±0.0091±0.0032\Delta\Gamma_s \equiv \Gamma_{L} - \Gamma_{H} = 0.0805 \pm 0.0091 \pm 0.0032ps1^{-1}, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements of those quantities to date. A combined analysis with Bs0J/ψπ+πB_s^{0} \to J/\psi \pi^+\pi^- decays gives ϕs=0.010±0.039\phi_s = -0.010 \pm 0.039 rad. All measurements are in agreement with the Standard Model predictions. For the first time the phase ϕs\phi_s is measured independently for each polarisation state of the K+KK^+K^- system and shows no evidence for polarisation dependence.Comment: 6 figure

    First observation and amplitude analysis of the BD+KπB^{-}\to D^{+}K^{-}\pi^{-} decay

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    The BD+KπB^{-}\to D^{+}K^{-}\pi^{-} decay is observed in a data sample corresponding to 3.0 fb13.0~\rm{fb}^{-1} of pppp collision data recorded by the LHCb experiment during 2011 and 2012. Its branching fraction is measured to be B(BD+Kπ)=(7.31±0.19±0.22±0.39)×105{\cal B}(B^{-}\to D^{+}K^{-}\pi^{-}) = (7.31 \pm 0.19 \pm 0.22 \pm 0.39) \times 10^{-5} where the uncertainties are statistical, systematic and from the branching fraction of the normalisation channel BD+ππB^{-}\to D^{+}\pi^{-}\pi^{-}, respectively. An amplitude analysis of the resonant structure of the BD+KπB^{-}\to D^{+}K^{-}\pi^{-} decay is used to measure the contributions from quasi-two-body BD0(2400)0KB^{-}\to D_{0}^{*}(2400)^{0}K^{-}, BD2(2460)0KB^{-}\to D_{2}^{*}(2460)^{0}K^{-}, and BDJ(2760)0KB^{-}\to D_{J}^{*}(2760)^{0}K^{-} decays, as well as from nonresonant sources. The DJ(2760)0D_{J}^{*}(2760)^{0} resonance is determined to have spin~1.Comment: 39 pages, 10 figures, submitted to Phys. Rev. D. Updated following erratum 10.1103/PhysRevD.93.11990
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