4,264 research outputs found

    L'encéphalite de la maladie de Carré du chien, modèle expérimental pour la neuropathologie humaine

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    Guillon J.-C., Reculard Pierre. L’encéphalite de la maladie de Carré du Chien. Modèle expérimental pour la neuropathologie humaine. In: Bulletin de l'Académie Vétérinaire de France tome 123 n°6, 1970. pp. 293-298

    Barometric pumping of a fractured porous medium

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    International audienceBarometric pumping plays a crucial role in the release of trace gases from fractured porous media to the atmosphere, and it requires a rigorous and complete modeling in order to go beyond the approximate schemes available in the literature. Therefore, a coupled set of convection and convection-diffusion equations for a slightly compressible fluid in unsteady conditions should be solved. The numerical methodology is presented, and it is applied to conditions close to the ones of the Roselend Natural Laboratory (France). The precision of the code is assessed and the mechanism of barometric pumping is explained. The usual schematization by simple vertical fractures is shown to be only qualitative. Finally, barometric pumping is shown to be efficient in a narrow range of parameter values; its efficiency is a decreasing function of the matrix porosity and of the fracture density

    G0^0 Electronics and Data Acquisition (Forward-Angle Measurements)

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    The G0^0 parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for ep\vec{e}p elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G0^0 experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G0^0 forward-angle measurements.Comment: 35 pages. 17 figures. This article is to be submitted to NIM section A. It has been written with Latex using \documentclass{elsart}. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment In Press (2007

    Intérêt des contrôles histopathologiques dans le dépistage des maladies des poissons Application à la Salmoniculture

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    Levaditi J. C., Besse P., Kinkelin Pierre de, Guillon J. C., Jacotot H. Intérêt des contrôles histopathologiques dans le dépistage des maladies des poissons. Application à la salmoniculture. In: Bulletin de l'Académie Vétérinaire de France tome 118 n°5, 1965. pp. 173-183

    X-Ray Diffraction Intensities of a Smectic-A Liquid Crystal

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    Higher-order diffraction from the smectic-A liquid-crystalline phase of cyanooctylbiphenyl (COB) has been measured. The dominant short-range disorder, described by the relative intensities, is in agreement with our estimate of the smectic order parameter based on McMillan's mean-field theory

    Deeply Virtual Compton Scattering off the neutron

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    The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D(e,eγ)X({\vec e},e'\gamma)X cross section measured at Q2Q^2=1.9 GeV2^2 and xBx_B=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to EqE_q, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.Comment: Published in Phys. Rev. Let

    The E00-110 experiment in Jefferson Lab's Hall A: Deeply Virtual Compton Scattering off the Proton at 6 GeV

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    We present final results on the photon electroproduction (epepγ\vec{e}p\rightarrow ep\gamma) cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region from Jefferson Lab experiment E00-110. Results from an analysis of a subset of these data were published before, but the analysis has been improved which is described here at length, together with details on the experimental setup. Furthermore, additional data have been analyzed resulting in photon electroproduction cross sections at new kinematic settings, for a total of 588 experimental bins. Results of the Q2Q^2- and xBx_B-dependences of both the helicity-dependent and helicity-independent cross sections are discussed. The Q2Q^2-dependence illustrates the dominance of the twist-2 handbag amplitude in the kinematics of the experiment, as previously noted. Thanks to the excellent accuracy of this high luminosity experiment, it becomes clear that the unpolarized cross section shows a significant deviation from the Bethe-Heitler process in our kinematics, compatible with a large contribution from the leading twist-2 DVCS2^2 term to the photon electroproduction cross section. The necessity to include higher-twist corrections in order to fully reproduce the shape of the data is also discussed. The DVCS cross sections in this paper represent the final set of experimental results from E00-110, superseding the previous publication.Comment: 48 pages, 32 figure

    SoLid : Search for Oscillations with Lithium-6 Detector at the SCK-CEN BR2 reactor

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    Sterile neutrinos have been considered as a possible explanation for the recent reactor and Gallium anomalies arising from reanalysis of reactor flux and calibration data of previous neutrino experiments. A way to test this hypothesis is to look for distortions of the anti-neutrino energy caused by oscillation from active to sterile neutrino at close stand-off (similar to 6-8m) of a compact reactor core. Due to the low rate of anti-neutrino interactions the main challenge in such measurement is to control the high level of gamma rays and neutron background. The SoLid experiment is a proposal to search for active-to-sterile anti-neutrino oscillation at very short baseline of the SCK center dot CEN BR2 research reactor. This experiment uses a novel approach to detect anti-neutrino with a highly segmented detector based on Lithium-6. With the combination of high granularity, high neutron-gamma discrimination using 6LiF:ZnS(Ag) and precise localization of the Inverse Beta Decay products, a better experimental sensitivity can be achieved compared to other state-of-the-art technology. This compact system requires minimum passive shielding allowing for very close stand off to the reactor. The experimental set up of the SoLid experiment and the BR2 reactor will be presented. The new principle of neutrino detection and the detector design with expected performance will be described. The expected sensitivity to new oscillations of the SoLid detector as well as the first measurements made with the 8 kg prototype detector deployed at the BR2 reactor in 2013-2014 will be reported

    Estime de soi et troubles psychiatriques à l'adolescence.

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    peer reviewedSelf-esteem refers to the individual's perception of his and her competence, value, and worthiness of respect. The early years are critical in forming a base of self-esteem; it develops as a result of positive or negative experiences during childhood. Self-esteem has been identified as an important parameter of adolescent development. This suggest the importance of considering self-esteem in adolescence. This study examined the different data on self-esteem of well adolescents and psychiatric adolescents. The results are discusse
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