3,499 research outputs found

    Failure analysis of destructive coils

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    The failure of the destructive pulsed power coils has been investigated. The destructive coil is the key element of the laboratory system which generates half-period abrupt magnetic field pulses with the amplitudes up to 45 T. The transient coupled non-linear magneto-mechanical model has been applied for finite element simulations. The mechanical behavior and operation threshold of the coil have been examined. It has been found that operation threshold of the coil with relatively thin cylindrical reinforcement could be characterized by the opening of the plastic hinge and estimated numerically. Good agreement with experimental results has been observe

    Las incrustaciones biológicas del puerto de Mar del Plata (Argentina): periodo 1976/77

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    Cuando se iniciaron en 1964 las investigaciones sobre las comunidades incrustantes de las costas argentinas, se tom√≥ como principal √°rea de estudios al puerto de Mar del Plata. Ello respond√≠a b√°sicamente a la importancia del mismo como puerto pesquero, comercial y t√°ctico, como as√≠ tambi√©n su proximidad con los institutos vinculados con los diversos aspectos de las investigaciones proyectadas. Los estudios realizados durante el mencionado per√≠odo seguramente convierten al puerto de Mar del Plata en el mejor conocido de toda Latinoam√©rica en cuanto a la din√°mica de sus comunidades incrustantes. Las investigaciones realizadas hasta el presente han comprendido tanto aspectos ecol√≥gicos generales de la comunidad como tambi√©n estudios particulares sobre organismos de especial inter√©s desde el punto de vista aplicado. Estos estudios se llevaron a cabo por per√≠odos anuales, empleando para ello sustratos artificiales sobre balsas experimentales y complementados en muchos casos con experiencias de laboratorio, observaciones de sustratos naturales, etc. El presente trabajo constituye el resultado de una nueva experiencia anual (1976/77) mediante el empleo de balsa experimental que complementa el panorama obtenido en a√Īos previos sobre el conjunto de la comunidad incrustante local. El mismo constituye el √ļltimo ensayo de tipo general sobre la comunidad a realizarse en la zona, ya que se considera cubierto el panorama b√°sico local. Los esfuerzos futuros a desarrollar en este puerto se limitar√°n, en lo que hace a los aspectos biol√≥gicos, a investigaciones particulares sobre especies incrustantes de alta resistencia t√≥xica. La tarea realizada inicialmente en el puerto de Mar del Plata ha sido proseguida en otras √°reas portuarias de Argentina, con la finalidad de conocer las caracter√≠sticas de este problema en los principales puertos de nuestra extensa costa mar√≠tima

    Failure analysis of destructive coils

    Get PDF
    The failure of the destructive pulsed power coils has been investigated. The destructive coil is the key element of the laboratory system which generates half-period abrupt magnetic field pulses with the amplitudes up to 45 T. The transient coupled non-linear magneto-mechanical model has been applied for finite element simulations. The mechanical behavior and operation threshold of the coil have been examined. It has been found that operation threshold of the coil with relatively thin cylindrical reinforcement could be characterized by the opening of the plastic hinge and estimated numerically. Good agreement with experimental results has been observe

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip

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    The ATLAS Collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing pixel detector and the vacuum pipe of the Large Hadron Collider. The extreme operating conditions at this location have necessitated the development of new radiation hard pixel sensor technologies and a new front-end readout chip, called the FE-I4. Planar pixel sensors and 3D pixel sensors have been investigated to equip this new pixel layer, and prototype modules using the FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test results are presented, including charge collection efficiency, tracking efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector