67 research outputs found

    A Small but Efficient Collaboration for the Spiral2 Control System Development

    Get PDF
    http://accelconf.web.cern.ch/AccelConf/ICALEPCS2013/papers/tucobab01.pdfThe Spiral2 radioactive ion beam facility to be commissioned in 2014 at Ganil (Caen) is built within international collaborations. This also concerns the control system development shared by three laboratories: Ganil has to coordinate the control and automated systems work packages, CEA/IRFU is in charge of the "injector" (sources and low energy beam lines) and the LLRF, CNRS/IPHC provides the emittancemeters and a beam diagnostics platform. Besides the technology Epics based, this collaboration, although being handled with a few people, nevertheless requires an appropriate and tight organization to reach the objectives given by the project. This contribution describes how, started in 2006, the collaboration for controls has been managed both from the technological point of view and the organizational one, taking into account not only the previous experience, technical background or skill of each partner, but also their existing working practices and "cultural" approaches. A first feedback comes from successful beam tests carried out at Saclay and Grenoble; a next challenge is the migration to operation, Ganil having to run Spiral2 as the other members are moving to new projects

    L’essai de rayure. Sur polymères et métaux. Modélisations et approches expérimentales

    No full text
    Nous avons effectué, dans cet article, une étude bibliographique de l’essai de rayure sur matériaux massifs, métalliques ou polymériques. Nous avons précisé les différents paramètres que l’on contrôle lors de l’essai : niveau de déformation, vitesse de rayage, température et lubrification. Les principales grandeurs calculées sont le rapport de la force tangentielle sur la force normale et la dureté rayure. On associe également à ces valeurs une observation par microscopie optique ou électronique qui permet de préciser le type d’endommagement induit dans les conditions de l’essai. Nous avons pu vérifier, grâce aux modèles numériques présentés dans cet article et aux nombreux essais issus de la littérature, que ces paramètres sont déterminants sur les résultats mesurés

    Realistic Deployments of LTE-based Hybrid Aerial-Terrestrial Networks for Public Safety

    No full text
    During a large-scale natural disaster or unexpected events, the terrestrial telecommunications become stretched, overloaded or totally destroyed in several cases. In these scenarios, a robust and capable emergency communication system is required to guarantee efficient communication to public safety agencies during the emergency phases. Airborne communication network systems have been recently studied for the provision of wireless communication services in those scenarios and it is a promising candidate for rapidly deployable and resilient emergency networks. However, the choice of communication technologies from aerial platforms is a challenging issue due to their payload capacity constraints. In this paper, we present a realistic Hybrid Aerial-Terrestrial Network (HATN) architecture based on the deployment of 4G-LTE Remote Radio Head (RRH) embedded on Helikite platforms and investigate their applicability and performance characteristics in emergency and unexpected scenarios. We present an adapted simulation model for the analysis of HATN. Our results confirm that the proposed architecture is able to provide high-capacity IP data HATN suitable for many forms of multimedia delivery

    Determining the stress–strain behaviour of small devices by nanoindentation in combination with inverse methods

    No full text
    The ongoing miniaturisation of thin films, coatings, micro-electromechanical systems (MEMS) components and devices demands for new characterising tools and methods. Conventional mechanical tests cannot be readily applied to small scales, first because one can expect new mechanical properties of such small-scale materials and second because minuscule samples are difficult to handle in conventional mechanical experiments such as tensile tests. Here we present a new method for determining the mechanical properties of LIGA (German acronym for ‘Lithographie, Galvanoformung und Abformung’) processed MEMS, mechanical watch parts and devices. The method is based on a reverse analysis of load-displacement data obtained from nanoindentation experiments that can be performed on micrometer sized volumes. To validate the method for typical applications in microengineering, a comparison of microtensile and nanoindentation tests is presented in this paper. The comparison of microtensile and nanoindentation tests showed that the elastic modulus obtained in nanoindentation for all tested materials was systematically about 15% higher than the values obtained in tensile testing, which can be attributed to the different size and microstructural levels that are probed. The numerical simulation of the nanoindentation tests allowed to estimate the true stress–true strain relationship up to strain levels of 30%, whereas in microtensile experiments the rheology of the tested materials can be determined to 5% only
    • …
    corecore