9,097 research outputs found

    The Physics Analysis Tools project for the ATLAS experiment

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    The Large Hadron Collider is expected to start colliding proton beams in 2009. The enormous amount of data produced by the ATLAS experiment (≈1 PB per year) will be used in searches for the Higgs boson and Physics beyond the standard model. In order to meet this challenge, a suite of common Physics Analysis Tools (PAT) has been developed as part of the Physics Analysis software project. These tools run within the ATLAS software framework, ATHENA, covering a wide range of applications. There are tools responsible for event selection based on analysed data and detector quality information, tools responsible for specific physics analysis operations including data quality monitoring and physics validation, and complete analysis toolkits (frameworks) with the goal to aid the physicist to perform his analysis hiding the details of the ATHENA framework

    Probing new physics in diphoton production with proton tagging at the Large Hadron Collider

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    The sensitivities to anomalous quartic photon couplings at the Large Hadron Collider are estimated using diphoton production via photon fusion. The tagging of the protons proves to be a very powerful tool to suppress the background and unprecedented sensitivities down to 6⋅10−156 \cdot 10^{-15}\gev−4^{-4} are obtained, providing a new window on extra dimensions and strongly-interacting composite states in the multi-TeV range. Generic contributions to quartic photon couplings from charged and neutral particles with arbitrary spin are also presented.Comment: 4 pages, 3 figure

    The population of deformed bands in 48^{48}Cr by emission of 8^{8}Be from the 32^{32}S + 24^{24}Mg reaction

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    Using particle-γ\gamma coincidences we have studied the population of final states after the emission of 2 α\alpha-particles and of 8^{8}Be in nuclei formed in 32^{32}S+24^{24}Mg reactions at an energy of EL(32S)=130MeV\textrm{E}_{\rm L}(^{32}\textrm{S}) = 130 {\rm MeV}. The data were obtained in a setup consisting of the GASP γ\gamma-ray detection array and the multidetector array ISIS. Particle identification is obtained from the Δ\DeltaE and E signals of the ISIS silicon detector telescopes, the 8^{8}Be being identified by the instantaneous pile up of the Δ\DeltaE and E pulses. γ\gamma-ray decays of the 48^{48}Cr nucleus are identified with coincidences set on 2 α\alpha-particles and on 8^{8}Be. Some transitions of the side-band with Kπ=4−K^\pi=4^{-} show stronger population for 8^{8}Be emission relative to that of 2 α\alpha-particles (by a factor 1.5−1.81.5-1.8). This observation is interpreted as due to an enhanced emission of 8^{8}Be into a more deformed nucleus. Calculations based on the extended Hauser-Feshbach compound decay formalism confirm this observation quantitatively.Comment: 17 pages, 9 figures accepted for publication in J. Phys.

    Optimisation of build orientation to achieve minimum environmental impact in Stereo-lithography

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    Abstract Additive Manufacturing includes a number of techniques that combine a specific equipment with certain materials but some common principles concerning the product design and aspects related to manufacturing optimisations can be identified. Amongst these principles, some process parameters are included that contribute to determining the environmental sustainability of engineering products and, in particular, that affect their Life Cycle Impact Assessment. This paper aims to provide a method to find out build orientation for the additive stereo-lithography process by minimising the environmental impact. More precisely, environmental indicators related to product design, materials and machines are included and combined in order to estimate the process time and the volume of needed supports. Besides, Genetic Algorithms have been used to find out the product orientation that optimises the manufacturing process in terms of quantity and volume of used material, thus minimizing its environmental impact. The proposed method has been implemented by a new software application that is presented in a nutshell

    Testosterone insulin-like effects: an in vitro study on the short-term metabolic effects of testosterone in human skeletal muscle cells

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    Testosterone by promoting different metabolic pathways contributes to short-term homeostasis of skeletal muscle, the largest insulin-sensitive tissue and the primary site for insulin-stimulated glucose utilization. Despite evidences indicate a close relationship between testosterone and glucose metabolism, the molecular mechanisms responsible for a possible testosterone-mediated insulin-like effects on skeletal muscle are still unknown

    Parametric Analysis of a Heavy Metal Sorption Isotherm Based on Fractional Calculus

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    Heavy metals are widely recognized as being hazardous to human health and environmentally aggressive. The literature reports different approaches for lead removal, for example, water hyacinths. Heavy metal sorption isotherm modeling represents an important tool towards the study of equilibrium conditions. Fractional calculus represents a novel approach and a growing research field for process modeling, based on derivatives of arbitrary order. Recently, a novel isotherm based on fractional calculus was proposed for lead sorption using water hyacinth (Eichhornia crassipes). This paper reports a general procedure on error analysis and its influence on parameter estimation. It was applied to mathematical models based on fractional differential equations, focusing on a heavy metal novel isotherm sorption model. Parameter variance was calculated by using two different approaches (with the complete Hessian matrix and with a simplified Hessian matrix), and joint parameter confidence regions were generated, being successfully able to show that the fractional nature of the model is statistically valid
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