2,229 research outputs found

    Las Vegas and Houston: Global Command Centers in the Sun Belt

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    Apart from their notoriously hot summers, Las Vegas, Nevada and Houston, Texas appear to have little in common. Upon further scrutiny, however, the two cities have followed strikingly parallel trajectories. As a hub of commercial gaming today, Las Vegas faces challenges comparable to the obstacles Houston encountered in the 1970s and 1980s as a hub of oil and energy. The story of Houston since this downtime reflects a stunning transformation into a modern-day international city, and one that both parallels and portends a new Las Vegas. In this article, we argue that Houston provides a viable model for Las Vegas as a “global command center” of a major international industry – and that in many ways Las Vegas is already following this path

    Households and tree-planting for wood energy production – Do perceptions matter?

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    While forests are a primary source of energy for the majority of Tanzanian households, the forest cover is rapidly declining. The Tanzanian government has introduced a tree-planting campaign strategy, aimed at reducing pressure on natural forests. However, the campaign appears not to have contributed significantly to the forest recovery rate. Thus, this study aims at examining household perceptions of tree-planting for wood energy production for both in-house uses and for sale, and identify the factors influencing household perceptions of tree-planting. We employed the multinomial logit model to analyse the factors influencing household perceptions of tree-planting for energy. Our findings indicate that respondents considered the right/freedom to harvest trees from farms and transport them to markets as the most important factor (86%), followed by lack of awareness of tree-planting programmes (72%), and the existence of fuelwood for free from natural forests (59%). The size of the farm, education, distance to forest reserves, and age of the household head are found to have significant impact on the household perceptions of tree-planting for energy. Our results further show that woodfuel harvesting and enforcement systems do not exist in nearby forests. This situation is exacerbated by the absence of a specific policy formulated to match with the daily demand of forest produce for energy and income of households near forest reserves. Thus, we suggest policy makers to target policies and actions promoting tree-planting for energy

    Disruption of normal body axis formation after teratogen exposure

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    International audienceUrban transport plans in France (UTPs) aim to develop mobility for everyone and to find a balance between cars, public transport and other transport modes, this in order to favour sustainable mobility. In this article, the question of the utility derived from such policies is raised for the inhabitants of Nantes, which was designated the ‘European Green Capital’ in 2013. We analyse the capitalization of various effects of urban transport policies in housing values. Using a hedonic price model, we show that housing values in Nantes are significantly determined by improved accessibility to the city centre. We highlight contrasting effects of UTPs on housing values depending on the location of apartments and on the mode of public transport. Households also internalize air and noise pollution generated by transportation, but they attach only a low value to pollution exposure

    A Technique for Collecting Water Samples Under Extreme Winter Conditions

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    Extremely narrow spectrum of GRB110920A: further evidence for localised, subphotospheric dissipation

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    Much evidence points towards that the photosphere in the relativistic outflow in GRBs plays an important role in shaping the observed MeV spectrum. However, it is unclear whether the spectrum is fully produced by the photosphere or whether a substantial part of the spectrum is added by processes far above the photosphere. Here we make a detailed study of the γ−\gamma-ray emission from single pulse GRB110920A which has a spectrum that becomes extremely narrow towards the end of the burst. We show that the emission can be interpreted as Comptonisation of thermal photons by cold electrons in an unmagnetised outflow at an optical depth of τ∌20\tau \sim 20. The electrons receive their energy by a local dissipation occurring close to the saturation radius. The main spectral component of GRB110920A and its evolution is thus, in this interpretation, fully explained by the emission from the photosphere including localised dissipation at high optical depths.Comment: 14 pages, 11 figures, accepted to MNRA

    Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings

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    Coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited by pulsed DC reactive sputter deposition on Si(100) at a temperature of 550 {\deg}C. XRD showed three different crystal structures depending on V-metal fraction in the coating: {\alpha}-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, 63 - 42 at.% V. At lower V-content, 18 and 7 at.%, a gamma-alumina-like solid solution was observed, shifted to larger d-spacing compared to pure {\gamma}-Al2O3. The microstructure changes from large columnar faceted grains for {\alpha}-V2O3 to smaller equiaxed grains when lowering the vanadium content toward pure {\gamma}-Al2O3. Annealing in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 {\deg}C for 42 at.% V and 700 {\deg}C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure {\gamma}-Al2O3-coating, which transformed to {\alpha}-Al2O3 after annealing to 1100{\deg} C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The latter decreased with increasing V-content, larger than 7 at.% V metal fraction. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings

    Interpolated sequences and critical LL-values of modular forms

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    Recently, Zagier expressed an interpolated version of the Ap\'ery numbers for ζ(3)\zeta(3) in terms of a critical LL-value of a modular form of weight 4. We extend this evaluation in two directions. We first prove that interpolations of Zagier's six sporadic sequences are essentially critical LL-values of modular forms of weight 3. We then establish an infinite family of evaluations between interpolations of leading coefficients of Brown's cellular integrals and critical LL-values of modular forms of odd weight.Comment: 23 pages, to appear in Proceedings for the KMPB conference: Elliptic Integrals, Elliptic Functions and Modular Forms in Quantum Field Theor
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