1,793 research outputs found

    Deconstructing and Reconstructing Hobbes

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    Plan and Contract in the Domestic and Foreign Trade of the U.S.S.R.

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    The purpose of this article is to inquire into the nature and function of contract law in a centrally planned economy. The economy chosen here is that of the Soviet Union. This study has been divided into two parts; the first part deals with the role of plan and contract in domestic trade, the second part deals with the place of contract and plan in the foreign trade of the Soviet Union

    Clean and Dirty Superconductivity in Pure, Al doped, and Neutron Irradiated MgB2: a Far-Infrared Study

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    The effects of Al substitution and neutron irradiation on the conduction regime (clean or dirty) of the π\pi- and σ\sigma-band of MgB2_{2} have been investigated by means of far-infrared spectroscopy. The intensity reflected by well characterized polycrystalline samples was measured up to 100 cm−1^{- 1} in both normal and superconducting state. The analysis of the superconducting to normal reflectivity ratios shows that only the effect of the opening of the small gap in the dirty π\pi-band can be clearly observed in pure MgB2_{2}, consistently with previous results. In Al-doped samples the dirty character of the π\pi-band is increased, while no definitive conclusion on the conduction regime of the σ\sigma -band can be drawn. On the contrary, results obtained for the irradiated sample show that the irradiation-induced disorder drives the σ\sigma-band in the dirty regime, making the large gap in σ\sigma-band observable for the first time in far-infrared measurements.Comment: 11 pages, 1 figur

    Pressure dependence of the charge-density-wave gap in rare-earth tri-tellurides

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    We investigate the pressure dependence of the optical properties of CeTe3_3, which exhibits an incommensurate charge-density-wave (CDW) state already at 300 K. Our data are collected in the mid-infrared spectral range at room temperature and at pressures between 0 and 9 GPa. The energy for the single particle excitation across the CDW gap decreases upon increasing the applied pressure, similarly to the chemical pressure by rare-earth substitution. The broadening of the bands upon lattice compression removes the perfect nesting condition of the Fermi surface and therefore diminishes the impact of the CDW transition on the electronic properties of RRTe3_3.Comment: 5 pages, 4 figure

    The Progressive Increase of Food Waste in America and Its Environmental Impact

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    Food waste contributes to excess consumption of freshwater and fossil fuels which, along with methane and CO2 emissions from decomposing food, impacts global climate change. Here, we calculate the energy content of nationwide food waste from the difference between the US food supply and the food consumed by the population. The latter was estimated using a validated mathematical model of metabolism relating body weight to the amount of food eaten. We found that US per capita food waste has progressively increased by ∼50% since 1974 reaching more than 1400 kcal per person per day or 150 trillion kcal per year. Food waste now accounts for more than one quarter of the total freshwater consumption and ∼300 million barrels of oil per year
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