1,470 research outputs found

    The Estimation of Prewar GNP: Methodology and New Evidence

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    The paper develops new methodology for the estimation of prewar GNP, taps previously unused data sources, and develops new estimates for the periods 1869-08 and 1869-28. Primary among the new data sources are direct measures of output in the transportation, communications, and construction sectors, and estimates of the consumer price index. New measures of real GNP, nominal GNP, and the GNP deflator are developed. The new estimates of real GNP are as volatile on average over the business cycle as the traditional Kuznets-Kendrick aeries but dampen the amplitude of some cycles while raising the amplitude of others. The new estimates of the GNP deflator are distinctly less volatile than the traditional series and in fact no more volatile than in the postwar period.

    The Estimation of Prewar GNP Volatility, 1869-1938

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    New evidence is provided to assess the recent controversy regarding the volatility of real economic activity before 1929 relative to the period since World War II. Some recent work claims that the longstanding stylized fact of greater prewar volatility is "spurious". In contrast, this paper reconfirms the greater amplitude of business fluctuations prior to the Great Depression. The basic technique is the regression method, which estimates equations for real GNP during 1909-38, with one or more explanatory variables for components of GNP, and then uses the estimated coefficients to "backcast" real GNP or the period 1869-1908. The paper contains an extensive examination of the sensitivity of these regression indexes to alternative dependent variables, sample periods, detrending methods, and the inclusion of alternative explanatory variables. Particular attention is paid to the conflicting evidence regarding the amplitude of cycles in construction activity between 1870 and 1890. The resulting prewar/postwar volatility ratios, for 1869-1928 as compared to 1950-1980, range from 1.43 to 2.16. The paper concludes by suggesting that this range of volatility ratios is more likely to understate than overstate the prewar/postwar volatility ratio.

    Properties of the quaternary half-metal-type Heusler alloy Co2_2Mn1−x_{1-x}Fex_xSi

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    This work reports on the bulk properties of the quaternary Heusler alloy Co2_2Mn1−x_{1-x}Fex_xSi with the Fe concentration x=x=. All samples, which were prepared by arc melting, exhibit L21L2_1 long range order over the complete range of Fe concentration. Structural and magnetic properties of Co2_2Mn1−x_{1-x}Fex_xSi Heusler alloys were investigated by means of X-ray diffraction, high and low temperature magnetometry, M{\"o\ss}bauer spectroscopy, and differential scanning calorimetry. The electronic structure was explored by means of high energy photo emission spectroscopy at about 8 keV photon energy. This ensures true bulk sensitivity of the measurements. The magnetization of the Fe doped Heusler alloys is in agreement with the values of the magnetic moments expected for a Slater-Pauling like behavior of half-metallic ferromagnets. The experimental findings are discussed on the hand of self-consistent calculations of the electronic and magnetic structure. To achieve good agreement with experiment, the calculations indicate that on-site electron-electron correlation must be taken into account, even at low Fe concentration. The present investigation focuses on searching for the quaternary compound where the half-metallic behavior is stable against outside influences. Overall, the results suggest that the best candidate may be found at an iron concentration of about 50%.Comment: 26 pages, 9 figures Phys. Rev. B accepte

    Feasibility study - 30 watt per pound roll-up solar array Quarterly technical report, 1 Jul. - 30 Sep. 1967

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    Configuration, rod tradeoff, and deployment parameter studies for design of solar panel arra

    Monitoring surface resonances on Co2MnSi(100) by spin-resolved photoelectron spectroscopy

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    The magnitude of the spin polarization at the Fermi level of ferromagnetic materials at room temperature is a key property for spintronics. Investigating the Heusler compound Co2_2MnSi a value of 93%\% for the spin polarization has been observed at room temperature, where the high spin polarization is related to a stable surface resonance in the majority band extending deep into the bulk. In particular, we identified in our spectroscopical analysis that this surface resonance is embedded in the bulk continuum with a strong coupling to the majority bulk states. The resonance behaves very bulk-like, as it extends over the first six atomic layers of the corresponding (001)-surface. Our study includes experimental investigations, where the bulk electronic structure as well as surface-related features have been investigated using spin-resolved photoelectron spectroscopy (SR-UPS) and for a larger probing depth spin-integrated high energy x-ray photoemission spectroscopy (HAXPES). The results are interpreted in comparison with first-principles band structure and photoemission calculations which consider all relativistic, surface and high-energy effects properly.Comment: 9 pages, 8 figures, Heusler alloy, electronic structure and photoemissio

    Nitric oxide regulates skeletal muscle fatigue, fiber type, microtubule organization, and mitochondrial ATP synthesis efficiency through cGMP-dependent mechanisms

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    Aim: Skeletal muscle nitric oxide–cyclic guanosine monophosphate (NO-cGMP) pathways are impaired in Duchenne and Becker muscular dystrophy partly because of reduced nNOSμ and soluble guanylate cyclase (GC) activity. However, GC function and the consequences of reduced GC activity in skeletal muscle are unknown. In this study, we explore the functions of GC and NO-cGMP signaling in skeletal muscle. Results: GC1, but not GC2, expression was higher in oxidative than glycolytic muscles. GC1 was found in a complex with nNOSμ and targeted to nNOS compartments at the Golgi complex and neuromuscular junction. Baseline GC activity and GC agonist responsiveness was reduced in the absence of nNOS. Structural analyses revealed aberrant microtubule directionality in GC1−/− muscle. Functional analyses of GC1−/− muscles revealed reduced fatigue resistance and postexercise force recovery that were not due to shifts in type IIA–IIX fiber balance. Force deficits in GC1−/− muscles were also not driven by defects in resting mitochondrial adenosine triphosphate (ATP) synthesis. However, increasing muscle cGMP with sildenafil decreased ATP synthesis efficiency and capacity, without impacting mitochondrial content or ultrastructure. Innovation: GC may represent a new target for alleviating muscle fatigue and that NO-cGMP signaling may play important roles in muscle structure, contractility, and bioenergetics. Conclusions: These findings suggest that GC activity is nNOS dependent and that muscle-specific control of GC expression and differential GC targeting may facilitate NO-cGMP signaling diversity. They suggest that nNOS regulates muscle fiber type, microtubule organization, fatigability, and postexercise force recovery partly through GC1 and suggest that NO-cGMP pathways may modulate mitochondrial ATP synthesis efficiency
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