3,133 research outputs found

    Mass-spectrometric study of the rhenium-oxygen system

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    Rhenium, having the second highest melting point among the metals, is used for refractory containers. Thermodynamic values for rhenium oxide is determined by mass spectrometry and X ray diffraction

    Welfare Reform and Food Stamp Caseload Dynamics

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    We use state-level panel data for federal fiscal years 1980–1998 to estimate the impacts of welfare reform and the business cycle on food stamp caseloads. The model we employ is a dynamic function of past caseloads, economic factors, AFDC and Food Stamp Program policies, political factors, AFDC caseload levels, and unobserved fixed and trending heterogeneity. Our results suggest that the robust economy has substantially influenced the recent decline in food stamp caseloads, but that the estimated aggregate effect of welfare reform is modest—we attribute around 45 percent of 1994–1998 decline to the macroeconomy and about 5 percent to welfare reform. We do find substantial heterogeneity in the impact of AFDC waiver policies. States with JOBS sanctions policies but not family cap or earnings disregard waivers can expect a larger long-run decline in caseloads than those states with all three policies. In addition, we do find some evidence, albeit weaker, that states with waivers for unemployed able-bodied adults without dependents can expect higher caseload levels than states without the waivers and that the Electronic Benefits Transfer program is leading to food stamp caseload declines. An important finding of this study is that modeling food stamp caseload dynamics has implications for the estimated effects of policy changes and economic factors—when dynamic models are employed, we observe substantially reduced welfare-reform effects but significantly increased effects of the macroeconomy on food stamp caseloads. These results are robust to models that permit the simultaneous determination of AFDC and food stamp caseloads.

    Regional similarities in the distributions of well yield from crystalline rocks in Fennoscandia

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    Well yields from Precambrian and Palaeozoic bedrock in Norway, Sweden and Finland exhibit very similar and approximately log-normal distributions: all three data sets exhibit a median yield of 600–700 L hr-1, despite the differences in climate and lithology. This similarity is tentatively reflected on a larger geographical scale by a meta-analysis of the international data sets on crystalline rock aquifers from other recently glaciated areas (i.e., without a thick regolith of weathered rock). An heuristic treatment of the Fennoscandian data sets suggests that this median yield is consistent with the following bulk properties of shallow (to c. 70–80 m depth) crystalline bedrock: transmissivity of 0.56 ± 0.30 m2 d-1 (6.4 ± 3.4 x 10-6 m2 s-1) and hydraulic conductivity of around 1.1 (± 0.6) x 10-7 m s-1

    New Limits on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales

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    We update the limit from the 90 GHz PIQUE ground-based polarimeter on the magnitude of any polarized anisotropy of the cosmic microwave radiation. With a second year of data, we have now limited both Q and U on a ring of 1 degree radius. The window functions are broad: for E-mode polarization, the effective l is = 191 +143 -132. We find that the E-mode signal can be no greater than 8.4 microK (95% CL), assuming no B-mode polarization. Limits on a possible B-mode signal are also presented.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter

    A CONSIDERATION OF THE DEVOLUTION OF FEDERAL AGRICULTURAL POLICY

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    Diverse needs and preferences across the United States provide justification for the devolution, or decentralization, of many Federal Government programs to the State or local level. The move toward devolution, however, has not been evidenced in U.S. agricultural policy, despite significant differences across States in such areas as commodity production, production costs, income distribution, and opportunities for off-farm work. The existing structure of USDA funding and program delivery already reflects an appreciation of the gains from devolution, with some programs accommodating differences in State and regional preferences. This report considers the implications of devolving $22 billion in 2003 budget outlays, mostly for domestic commodity and natural resource programs and rural development and housing programs. The local knowledge of needs and references is valuable and can provide the basis for increased program efficiency.Public policy, devolution, agricultural policy, program delivery, Agricultural and Food Policy,

    BLAST Autonomous Daytime Star Cameras

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    We have developed two redundant daytime star cameras to provide the fine pointing solution for the balloon-borne submillimeter telescope, BLAST. The cameras are capable of providing a reconstructed pointing solution with an absolute accuracy < 5 arcseconds. They are sensitive to stars down to magnitudes ~ 9 in daytime float conditions. Each camera combines a 1 megapixel CCD with a 200 mm f/2 lens to image a 2 degree x 2.5 degree field of the sky. The instruments are autonomous. An internal computer controls the temperature, adjusts the focus, and determines a real-time pointing solution at 1 Hz. The mechanical details and flight performance of these instruments are presented.Comment: 8 pages, 6 figures, 1 table. To be published in conference proceedings for the "Ground-based and Airborne Instrumentation for Astronomy" part of the SPIE Astronomical Telescopes and Instrumentation Symposium that will be held 24-31 May 2006 in Orlando, F

    COMPASS: a 2.6m telescope for CMBR polarization studies

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    COMPASS (COsmic Microwave Polarization at Small Scale) is an experiment devoted to measuring the polarization of the CMBR. Its design and characteristics are presented

    A Limit on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales

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    A ground-based polarimeter, PIQUE, operating at 90 GHz has set a new limit on the magnitude of any polarized anisotropy in the cosmic microwave background. The combination of the scan strategy and full width half maximum beam of 0.235 degrees gives broad window functions with average multipoles, l = 211+294-146 and l = 212+229-135 for the E- and B-mode window functions, respectively. A joint likelihood analysis yields simultaneous 95% confidence level flat band power limits of 14 and 13 microkelvin on the amplitudes of the E- and B-mode angular power spectra, respectively. Assuming no B-modes, a 95% confidence limit of 10 microkelvin is placed on the amplitude of the E-mode angular power spectrum alone.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter
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