123,426 research outputs found

    Digital manufacturing in fiat group automobiles: virtual simulations for preliminary ergonomics optimization of workcells in the design phase of a new car model

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    New standards on work organization in the automotive industry, require a new concept of design methods: the human centred process. In Fiat Group Automobiles (FGA) the “Digital Manufacturing” (DM) project has started with the goal to create simulation tools and methods to improve the design of new cars’manufacturing processes giving a special attention to manual operations. The DM approach is based on a detailed “virtual plant” where virtual mannequins interact with digital models of car’s components, equipment, containers, etc. in order to simulate and improve working conditions with many benefits on ergonomics, safety, final product quality, work organization and general production costs. The key factor for this approach is that with DM methodologies, designers and engineers have, already in the design phase of a new car’s manufacturing process, a preliminary estimation of the numerical indices used in the plants to check if workcells are compliant to international standards and regional safety laws. In this way the most important ergonomic indices (like Niosh, Snook & Ciriello, EAWS, etc.) become a “design tool” that allow to change/improve project solutions (designing easy and comfortable work tasks, equipment, tools, etc.) and to distribute the work load in an optimal way between workers

    Extragalactic jets: the high energy view

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    I review the current knowledge of high-energy emission from extragalctic jets. First I discuss gamma-ray emission from blazars, which provides us numerous precious information on the innermost portions of the relativistic jets. I describe the constraints on the dynamics of the jet from the subpc to the pc scale provided by recent VLBI studies of TeV sources, together with the modelling of the emission from the blazar jet. Finally I discuss high energy emission from large scale jets as seen by Chandra and I report on the expected gamma-ray emission from large-scale regions of jets.Comment: 17 pages, 10 figures. Invited review at the Xth Marcel Grossmann Meeting on General Relativity, Rio de Janeiro, Brazil, July 200

    Noise and current correlations in tunnel junctions of Quantum Spin Hall edge states

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    The edge channels of two-dimensional topological systems are protected from elastic reflection and are noiseless at low temperature. Yet, noise and cross-correlations can be induced when electron waves partly transmit to the opposite edge via tunneling through a constriction. In particular, in a quantum spin Hall (QSH) system tunnelling occurs via both spin-preserving (pp) and spin-flipping (ff) processes, each fulfilling time-reversal symmetry. We investigate the current correlations of a four-terminal QSH setup in the presence of a tunneling region, both at equilibrium and out-of-equilibrium. We find that, although pp and ff processes do not commute and the generic current correlation depends on both, under appropriate conditions a direct detection of two types of partition noise is possible. In particular, while the spin-preserving partitioning can be probed for any arbitrary tunnel junction with a specific configuration of terminal biases, the spin-flipping partitioning can be directly detected only under suitably designed setups and conditions. We describe two setups where these conditions can be fulfilled, and both types of partitioning can be detected and controlled.Comment: 11 pages, 4 figure

    Canonical surfaces of higher degree

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    We consider a family of surfaces of general type SS with KSK_S ample, having KS2=24,pg(S)=6,q(S)=0K^2_S = 24, p_g (S) = 6, q(S)=0. We prove that for these surfaces the canonical system is base point free and yields an embedding Φ1:SP5\Phi_1 : S \rightarrow \mathbb{P}^5. This result answers a question posed by G. and M. Kapustka. We discuss some related open problems, concerning also the case pg(S)=5p_g(S) = 5, where one requires the canonical map to be birational onto its image.Comment: 10 pages, dedicated to the 60th birthday of Philippe Elli

    Recent changes in drug abuse scenarios : The new/novel psychoactive substances (NPS) phenomenon

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    © 2018 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Peer reviewedFinal Published versio

    Top physics at the Tevatron Collider

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    The top quark has been discovered in 1995 at the CDF and DO experiments located in the Tevatron ring at the Fermilab laboratory. After more than a decade the Tevatron collider, with its center-of-mass energy collisions of 1.96 TeV, is still the only machine capable of producing such exceptionally heavy particle. Here I present a selection of the most recent CDF and DO measurements performed analyzing ~ 1 fb-1 of integrated luminosity.Comment: 5 pages, 4 figure, Proceedings 19th Conference on High Energy Physics (IFAE 2007), Naples, Italy, April 11-13, 200

    Recent Results on Heavy Flavours with ALEPH

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    The latest ALEPH measurements on heavy flavours are presented. In particular the measurements of V_ub, the B(b -> s gamma) and a study on the width difference between mass eigenstates in the B_s system are presented.Comment: 7 pages, RevTe
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