99,417 research outputs found

    The Joint COntrols Project Framework

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    The Framework is one of the subprojects of the Joint COntrols Project (JCOP), which is collaboration between the four LHC experiments and CERN. By sharing development, this will reduce the overall effort required to build and maintain the experiment control systems. As such, the main aim of the Framework is to deliver a common set of software components, tools and guidelines that can be used by the four LHC experiments to build their control systems. Although commercial components are used wherever possible, further added value is obtained by customisation for HEP-specific applications. The supervisory layer of the Framework is based on the SCADA tool PVSS, which was selected after a detailed evaluation. This is integrated with the front-end layer via both OPC (OLE for Process Control), an industrial standard, and the CERN-developed DIM (Distributed Information Management System) protocol. Several components are already in production and being used by running fixed-target experiments at CERN as well as for the LHC experiment test beams. The paper will give an overview of the key concepts behind the project as well as the state of the current development and future plans.Comment: Paper from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, PDF. PSN THGT00

    Interplay between the ionic and electronic density profiles in liquid metal surfaces

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    First principles molecular dynamics simulations have been performed for the liquid-vapor interfaces of liquid Li, Mg, Al and Si. We analize the oscillatory ionic and valence electronic density profiles obtained, their wavelengths and the mechanisms behind their relative phase-shift.Comment: Accepted for publication in Journal of Chemical Physic

    Parent Stars of Extrasolar Planets. XI. Trends with Condensation Temperature Revisited

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    We report the results of abundance analyses of new samples of stars with planets and stars without detected planets. We employ these data to compare abundance-condensation temperature trends in both samples. We find that stars with planets have more negative trends. In addition, the more metal-rich stars with planets display the most negative trends. These results confirm and extend the findings of Ramirez et al. (2009) and Melendez et al. (2009), who restricted their studies to solar analogs. We also show that the differences between the solar photospheric and CI meteoritic abundances correlate with condensation temperature.Comment: 7 pages, 11 figures; to be published in MNRA
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