18,757 research outputs found

    Adaptation to Climate Change: Land Use and Livestock Management Change in the U.S.

    Get PDF
    Replaced with revised version of paper 01/26/11Climate Change, Stocking Rate, Land Use, Livestock Management, Environmental Economics and Policy, Land Economics/Use, Livestock Production/Industries,

    Model Predictions for Neutrino Oscillation Parameters

    Get PDF
    We have surveyed leptonic and grand unified models of neutrino masses and mixings in the literature which are still viable and give numerical predictions for the reactor angle, θ13\theta_{13}. The results are of considerable interest in anticipation of the next generation reactor experiments and the possible future need for neutrino factories. Of the 63 models considered which were published or posted on the Archive before June 2006, half predict values of \sin^2 2\theta_{13} \gsim 0.015, which should yield positive signals for νˉe\bar{\nu}_e disappearance in the reactor experiments planned for the near future. Depending upon the outcome of those experiments, half of the models can be eliminated on the basis of the presence or absence of such an observed νˉe\bar{\nu}_e disappearance signal.Comment: 23 pages including 3 figures; published versio

    Use of low-energy hydrogen ion implants in high-efficiency crystalline-silicon solar cells

    Get PDF
    The use of low-energy hydrogen implants in the fabrication of high-efficiency crystalline silicon solar cells was investigated. Low-energy hydrogen implants result in hydrogen-caused effects in all three regions of a solar cell: emitter, space charge region, and base. In web, Czochralski (Cz), and floating zone (Fz) material, low-energy hydrogen implants reduced surface recombination velocity. In all three, the implants passivated the space charge region recombination centers. It was established that hydrogen implants can alter the diffusion properties of ion-implanted boron in silicon, but not ion-implated arsenic

    CLIMATE CHANGE INFLUENCES ON THE RISK OF AVIAN INFLUENZA OUTBREAKS AND ASSOCIATED ECONOMIC LOSS

    Get PDF
    This paper examines the effect that climate has on Avian Influenza outbreak probability. The statistical analysis shows across a broad region the probability of an outbreak declines by 0.22% when the temperature rises 1 Celsius degree and increases by 0.34% when precipitation increases by 1millimeter. These results indicate that the realized climate change of the last 20 years not only has been a factor behind recent HPAI outbreaks, but that climate change is likely to play an even greater role in the future. The statistical results indicate that overall, the risk of an AI outbreak has been increased by 51% under past climate change and 3-4% under future climate change. An economic evaluation shows the increased probability of outbreaks has caused damages of about 107millioninChinaand107 million in China and 29 million in the United States due to past climate change. In the year of 2011-2030, for countries with a high proportion of chicken production, economic loss could reach 105105-146 million in China and 1212-18 million in the United Sates.Climate change, Avian Influenza outbreaks, GDP loss, Environmental Economics and Policy, Research Methods/ Statistical Methods,

    Spectroscopy of q3qˉ3\rm{q}^3\bar{\rm{q}}^3-States in Quark Model and Baryon-Antibaryon Enhancements

    Full text link
    We study the mass spectrum of the q3qˉ3\rm{q}^3\bar{\rm{q}}^3 mesons both from the quark model with triquark correlations and from common quark model with colormagnetic interactions and with relative S-waves between quarks. Two cluster configurations (q3)(qˉ3)(\rm{q}^3)-(\bar{\rm{q}}^3) and (q2qˉ)(qqˉ2)(\rm{q}^2\bar{\rm{q}})-(\rm{q}\bar{\rm{q}}^2) are considered. In the spectrum we find rather stable states which have the same quantum number with particle resonances which are corresponding to the ppˉp\bar{p} enhancement, pΛˉp\bar{\Lambda} enhancement and ΛΛˉ\Lambda\bar{\Lambda} enhancement with spin-0\mathbf{0} or 1\mathbf{1}. This imply these enhancements are NOT experimental artifacts. The color-spin-flavor structures of ppˉp\bar{p}, pΛˉp\bar{\Lambda}, and ΛΛˉ\Lambda\bar{\Lambda} enhancements are revealed. The existence of spin-1\mathbf{1} ΛΛˉ,pΛˉ,ppˉ\Lambda\bar{\Lambda}, p\bar{\Lambda}, p\bar{p} enhancements is predicted.Comment: 45 pages, 5 figure

    Structural study on hole-doped superconductors Pr1-xSrxFeAsO

    Full text link
    The structural details in Pr1-xSrxFeAsO (1111) superconducting system are analyzed using data obtained from synchrotron X-ray diffraction and the structural parameters are carefully studied as the system is moving from non-superconducting to hole-doped superconducting with the Sr concentration. Superconductivity emerges when the Sr doping amount reaches 0.221. The linear increase of the lattice constants proves that Sr is successfully introduced into the system and its concentration can accurately be determined by the electron density analyses. The evolution of structural parameters with Sr concentration in Pr1-xSrxFeAsO and their comparison to other similar structural parameters of the related Fe-based superconductors suggest that the interlayer space between the conducting As-Fe-As layer and the insulating Pr-O-Pr layer is important for improving Tc in the hole-doped (1111) superconductors, which seems to be different from electron-doped systems.Comment: 17 pages, 7 figures, 1 tabl

    Angular dependence of resistivity in the superconducting state of NdFeAsO0.82_{0.82}F0.18_{0.18} single crystals

    Full text link
    We report the results of angle dependent resistivity of NdFeAsO0.82_{0.82}F0.18_{0.18} single crystals in the superconducting state. By doing the scaling of resistivity within the frame of the anisotropic Ginzburg-Landau theory, it is found that the angle dependent resistivity measured under different magnetic fields at a certain temperature can be collapsed onto one curve. As a scaling parameter, the anisotropy Γ\Gamma can be determined for different temperatures. It is found that Γ(T)\Gamma(T) increases slowly with decreasing temperature, varying from Γ\Gamma \simeq 5.48 at T=50 K to Γ\Gamma \simeq 6.24 at T=44 K. This temperature dependence can be understood within the picture of multi-band superconductivity.Comment: 7 pages, 4 figure

    Spin-Polarized Transport in Ferromagnet-Marginal Fermi Liquid Systems

    Full text link
    Spin-polarized transport through a marginal Fermi liquid (MFL) which is connected to two noncollinear ferromagnets via tunnel junctions is discussed in terms of the nonequilibrium Green function approach. It is found that the current-voltage characteristics deviate obviously from the ohmic behavior, and the tunnel current increases slightly with temperature, in contrast to those of the system with a Fermi liquid. The tunnel magnetoresistance (TMR) is observed to decay exponentially with increasing the bias voltage, and to decrease slowly with increasing temperature. With increasing the coupling constant of the MFL, the current is shown to increase linearly, while the TMR is found to decay slowly. The spin-valve effect is observed.Comment: 5 pages, 6 figures, Phys. Rev. B 71, 064412 (2005
    corecore