3,162 research outputs found

    Maladie de kimura: À propos d’un cas

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    Introduction :  Mots-clés : Maladie de Kimura, parotide, chirurgie.La maladie de Kimura ou lymphogranulome éosinophile est une pathologie inflammatoire chronique très rare, d’étiologie inconnue. Nous rapportons un cas de maladie de Kimura à localisation parotidienne et à travers une revue de la littérature, rappelons les principales caractéristiques cliniques, paracliniques, thérapeutiques et évolutives de cette pathologie. Matériel et méthodes : Patient de 17 ans qui a consulté devant l’apparition d’une tuméfaction de la région parotidienne gauche évoluant depuis un an et sans paralysie faciale. Résultats : L’échographie cervico-parotidienne a révélé une parotide gauche hypertrophiée siège de multiples nodules hypoéchogènes. La tomodensitométrie cervico-faciale a mis en évidence une glande parotide gauche augmentée de taille et de structure hétérogène nodulaire sans adénopathies cervicales. La cytopontion était non concluante. Le patient a bénéficié d’une parotidectomie exofaciale gauche et l’étude anatomopathologique de la pièce opératoire revenue en faveur de la maladie de Kimura. Les suites opératoires étaient simples. Le recul est d’un an sans récidive. Discussion : La Maladie de Kimura se caractérise cliniquement par des nodules sous cutanés de localisation cervicofaciale, une augmentation du volume des glandes salivaires et des adénopathies satellites. Son diagnostic est histologique reposant sur l’identification d’une hyperplasie follicullaire avec des abcès à polynucléaires éosinophiles. Le traitement est chirurgical le plus souvent mais dans certains cas la corticothérapie est proposée. Ce diagnostic doit cependant rester à l’esprit devant toute masse cervico-faciale

    Theoretical investigation of topological ferrimagnetic intertwining double chain

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    In this paper, a novel trimeric chain approach to organometallic ferrimagnetics is proposed. The inter and intratrimer exchange interaction has been determined to be antiferromagnetic from a theoretical model magnetic susceptibility. The Curie law observed at very low temperature (q = 5.764 K l0) contrasts with significant ferromagnetic behaviour. The magnetic data were fitted with the IDC model. The compounds interestingly exhibit ferrimagnetic interactions with gCu1 =1.81, gCu2 =2.04 and gCu3 =2.43; J1 =-89.93K and J2= -2.68 KIn this paper, a novel trimeric chain approach to organometallic ferrimagnetics is proposed. The inter and intratrimer exchange interaction has been determined to be antiferromagnetic from a theoretical model magnetic susceptibility. The Curie law observed at very low temperature (q = 5.764 K l0) contrasts with significant ferromagnetic behaviour. The magnetic data were fitted with the IDC model. The compounds interestingly exhibit ferrimagnetic interactions with gCu1 =1.81, gCu2 =2.04 and gCu3 =2.43; J1 =-89.93K and J2= -2.68

    Investigation of the performance of an optimised MicroCAT, a GEM and their combination by simulations and current measurements

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    A MicroCAT (Micro Compteur A Trous) structure which is used for avalanche charge multiplication in gas filled radiation detectors has been optimised with respect to maximum electron transparency and minimum ion feedback. We report on the charge transfer behaviour and the achievable gas gain of this device. A three-dimensional electron and ion transfer simulation is compared to results derived from electric current measurements. Similarly, we present studies of the charge transfer behaviour of a GEM (Gas Electron Multiplier) by current measurements and simulations. Finally, we investigate the combination of the MicroCAT and the GEM by measurements with respect to the performance at different voltage settings, gas mixtures and gas pressures.Comment: 26 pages, 32 figure

    Position resolution and efficiency measurements with large scale Thin Gap Chambers for the super LHC

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    New developments in Thin Gap Chambers (TGC) detectors to provide fast trigger and high precision muon tracking under sLHC conditions are presented. The modified detectors are shown to stand a high total irradiation dose equivalent to 6 Coulomb/cm of wire, without showing any deterioration in their performance. Two large (1.2 x 0.8 m^2) prototypes containing four gaps, each gap providing pad, strips and wires readout, with a total thickness of 50 mm, have been constructed. Their local spatial resolution has been measured in a 100 GeV/c muon test beam at CERN. At perpendicular incidence angle, single gap position resolution better than 60 microns has been obtained. For incidence angle of 20 degrees resolution of less than 100 micron was achieved. TGC prototypes were also tested under a flux of 10^5 Hz/cm^2 of 5.5-6.5 MeV neutrons, showing a high efficiency for cosmic muons detection.Comment: Presented at the 12 Vienna conference on Instrumentation, February 201

    Effects of Phenol Addition on Oil Extraction from Moroccan Oil Shale by Supercritical Toluene

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    In the present work, the effect of phenol on the supercritical extraction of the organic matter from Tarfaya's oil shale with toluene was evaluated. The experimental results showed clearly that phenol had a significant effect on the yield and the composition of the oils obtained. Moreover, it was shown that phenol was a very efficient modifier for oil shale, giving a good yield of recovery and a suitable maturation of the organic matter. The pitches prepared by mixing phenol and toluene contain more aromatics and have a high char yield at 950 °C compared to those obtained by extraction with supercritical toluene alone

    Measurement of shower development and its Moli\`ere radius with a four-plane LumiCal test set-up

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    A prototype of a luminometer, designed for a future e+e- collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Moli\`ere radius has been determined to be 24.0 +/- 0.6 (stat.) +/- 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.Comment: Paper published in Eur. Phys. J., includes 25 figures and 3 Table

    Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

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    Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.Comment: 25 pages, 32 figures, revised version following comments from referee

    System Test of the ATLAS Muon Spectrometer in the H8 Beam at the CERN SPS

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    An extensive system test of the ATLAS muon spectrometer has been performed in the H8 beam line at the CERN SPS during the last four years. This spectrometer will use pressurized Monitored Drift Tube (MDT) chambers and Cathode Strip Chambers (CSC) for precision tracking, Resistive Plate Chambers (RPCs) for triggering in the barrel and Thin Gap Chambers (TGCs) for triggering in the end-cap region. The test set-up emulates one projective tower of the barrel (six MDT chambers and six RPCs) and one end-cap octant (six MDT chambers, A CSC and three TGCs). The barrel and end-cap stands have also been equipped with optical alignment systems, aiming at a relative positioning of the precision chambers in each tower to 30-40 micrometers. In addition to the performance of the detectors and the alignment scheme, many other systems aspects of the ATLAS muon spectrometer have been tested and validated with this setup, such as the mechanical detector integration and installation, the detector control system, the data acquisition, high level trigger software and off-line event reconstruction. Measurements with muon energies ranging from 20 to 300 GeV have allowed measuring the trigger and tracking performance of this set-up, in a configuration very similar to the final spectrometer. A special bunched muon beam with 25 ns bunch spacing, emulating the LHC bunch structure, has been used to study the timing resolution and bunch identification performance of the trigger chambers. The ATLAS first-level trigger chain has been operated with muon trigger signals for the first time

    Background Light in Potential Sites for the ANTARES Undersea Neutrino Telescope

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    The ANTARES collaboration has performed a series of {\em in situ} measurements to study the background light for a planned undersea neutrino telescope. Such background can be caused by 40^{40}K decays or by biological activity. We report on measurements at two sites in the Mediterranean Sea at depths of 2400~m and 2700~m, respectively. Three photomultiplier tubes were used to measure single counting rates and coincidence rates for pairs of tubes at various distances. The background rate is seen to consist of three components: a constant rate due to 40^{40}K decays, a continuum rate that varies on a time scale of several hours simultaneously over distances up to at least 40~m, and random bursts a few seconds long that are only correlated in time over distances of the order of a meter. A trigger requiring coincidences between nearby photomultiplier tubes should reduce the trigger rate for a neutrino telescope to a manageable level with only a small loss in efficiency.Comment: 18 pages, 8 figures, accepted for publication in Astroparticle Physic
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