Calculation of the neutron spectra from proton-nucleus nonelastic collisions in the energy range 15-18 MeV and comparison with experiment

Neutron spectra calculations from proton-nucleus inelastic collisions for 15 to 18 MeV proton

Electron correlation effects in diamond: a wave-function quantum chemistry study of the quasiparticle band structure

The quasiparticle bands of diamond, a prototype covalent insulator, are herein studied by means of wave-function electronic-structure theory, with emphasis on the nature of the correlation hole around a bare particle. Short-range correlations are in such a system conveniently described by using a real-space representation and many-body techniques from {\it ab initio} quantum chemistry. To account for long-range polarization effects, on the other hand, we adopt the approximation of a dielectric continuum. Having as "uncorrelated" reference the Hartree-Fock band structure, the post-Hartree-Fock treatment is carried out in terms of localized Wannier functions derived from the Hartree-Fock solution. The computed correlation-induced corrections to the relevant real-space matrix elements are important and give rise to a strong reduction, in the range of $50\%$, of the initial Hartree-Fock gap. While our final results for the indirect and direct gaps, 5.4 and 6.9 eV, respectively, compare very well with the experimental data, the width of the valence band comes out by $10$ to $15\%$ too large as compared to experiment. This overestimation of the valence-band width appears to be related to size-consistency effects in the configuration-interaction correlation treatment.Comment: 16 pages, 7 figures, accepted at Phys. Rev. B (2014

psbA mutation (Ala251 to Val) in Chenopodium album resistant to triazinones

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THE KNEE INJURIES IN SKIING: MECHANISMS AND ASSESSMENT

The purpose of this study is to describe the main mechanisms of knee injuries in skiing, and especially the dominant role of anterior cruciate ligament in these injuries. To complete classical clinical tests of ligamentous laxity and help defining the appropriate time to return to sports after an anterior cruciate ligament reconstruction, accurate 3D kinematic assessment of the weight-bearing knee joint is essential. Current limits of such an assessment are described. Then recent studies of patients with anterior cruciate ligament deficient and reconstructed, using a tibio femoral tracking device specially designed to analyse the kinematics of the knee, are presented

Nitrous oxide in the deep waters of the world's oceans

We present a compilation and analysis Of N2O data from the deep-water zone of the oceans below 2000 m. The N2O values show an increasing trend from low concentrations in the North Atlantic Ocean to high concentrations in the North Pacific Ocean, indicating an accumulation of N2O in deep waters with time. We conclude that the observed N2O accumulation is mainly caused by nitrification in the global deep-water circulation system (i.e., the “conveyor belt”). Hydrothermal and sedimentary N2O fluxes are negligible. We estimate the annual N2O deep-water production to be 0.3 ± 0.1 Tg. Despite the fact that the deep sea below 2000 m represents about 95% of the total ocean volume, it contributes only about 3–16% to the global open-ocean N2O production. A rough estimate of the oceanic N2O budget suggests that the loss to the atmosphere is not balanced by the deep-sea nitrification and pelagic denitrification. Therefore an additional source of 3.8 Tg N2O yr−1 attributed to nitrification in the upper water column (0–2000 m) might exist. With a simple model we estimated the effect of changes in the North Atlantic Deep Water (NADW) formation for deep-water N2O. The upper water N2O budget is not significantly influenced by variations in the N2O deep-water formation. However, the predicted decrease in the NADW formation rate in the near future might lead to an additional source of atmospheric N2O in the range of about 0.02-0.4 Tg yr−1. This (anthropogenically induced) source is small, and it will be difficult to detect its signal against the natural variations in the annual growth rates of tropospheric N2O

Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction

We investigate the current-phase relation of S/F/S junctions near the crossover between the 0 and the pi ground states. We use Nb/CuNi/Nb junctions where this crossover is driven both by thickness and temperature. For a certain thickness a non-zero minimum of critical current is observed at the crossover temperature. We analyze this residual supercurrent by applying a high frequency excitation and observe the formation of half-integer Shapiro steps. We attribute these fractional steps to a doubling of the Josephson frequency due to a sin(2*phi) current-phase relation. This phase dependence is explained by the splitting of the energy levels in the ferromagnetic exchange field.Comment: 4 pages, 5 figures, accepted for publication in Phys. Rev. Let

American Indians and the Burger Court

Objective. Like many politically disadvantaged groups, American Indian interests have turned to the courts when they lack access or clout in the electoral process. Unlike many ocher disadvantaged groups, the litigation activities of American Indian interests have failed to garner much scholarly attention. The purpose of this research is to examine how American Indian interests fared before the Burger Court (1969-85 October terms). Methods. The 63 full opinion cases regarding issues critical to American Indian interests were identified by examining the United States Reports. Each case was coded as whether or not the Court decided in favor of the party advancing American Indian interests. Results. American Indian interests won over one-half of the cases decided by the Burger Court during the 1969-85 terms. Additionally, the appellant status of the party advancing American Indian interests and the issue area being litigated were important determinants in the direction of the Burger Court\u27s decisions. Conclusions. While American Indian interests won more cases than they lost during the 1969-85 terms, the Burger Court\u27s decisions did not result in a coherent body of law

The Clerk Connection: Appearances Before the Supreme Court by Former Law Clerks

Judicial scholars long have examined the external factors influencing U.S. Supreme Court decision making. Congressional and executive pressures, the Office of the U.S. Solicitor General, attorney experience, and the tactics of organized interests all have been found to be influential

First results on closed-loop tune control in the CERN-SPS

This paper presents the first measurements performed with the SPS Qloop. The emphasis will be laid on the model used for designing the regulation loop and how well it fits reality