3,465 research outputs found

    Elliptic Flow from Non-equilibrium Initial Condition with a Saturation Scale

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    A current goal of relativistic heavy ion collisions experiments is the search for a Color Glass Condensate as the limiting state of QCD matter at very high density. In viscous hydrodynamics simulations, a standard Glauber initial condition leads to estimate 4πη/s∼14\pi \eta/s \sim 1, while a Color Glass Condensate modeling leads to at least a factor of 2 larger η/s\eta/s. Within a kinetic theory approach based on a relativistic Boltzmann-like transport simulation, we point out that the out-of-equilibrium initial distribution proper of a Color Glass Condensate reduces the efficiency in building-up the elliptic flow. Our main result at RHIC energy is that the available data on v2v_2 are in agreement with a 4πη/s∼14\pi \eta/s \sim 1 also for Color Glass Condensate initial conditions, opening the possibility to describe self-consistently also higher order flow, otherwise significantly underestimated, and to pursue further the search for signatures of the Color Glass Condensate.Comment: 6 pages, 4 figures. // Title changed, some discussion added, main conclusions unchanged. Version accepted for publication on Phys. Lett.

    Feasibility of an EHF (40/50 GHz) mobile satellite system using highly inclined orbits

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    The pan-European L-band terrestrial cellular system (GSM) is expected to provide service to more than 10 million users by the year 2000. Discussed here is the feasibility of a new satellite system at EHF (40/50 GHz) to complement, at the end of the decade, the GSM system or its decendants in order to provide additional services at 64 kbits/s, or so. The main system aspects, channel characteristics, technology issues, and both on-board and earth terminal architectures are highlighted. Based on the performed analyses, a proposal was addressed to the Italian Space Agency (ASI), aimed at the implementation of a national plan

    Italy

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    Il volume \ue8 uno studio comparativo degli ordinamenti giuridici dei 27 Stati membri dell'Unione europea. Il contributo di cui il sottoscritto risulta co-autore insieme a Ruggieri F. espone in inglese, in un formato comune, i tratti essenziali della procedura penale italiana

    Hot Quark Matter with an Axial Chemical Potential

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    We analyze the phase diagram of hot quark matter in presence of an axial chemical potential, μ5\mu_5. The latter is introduced to mimic the chirality transitions induced, in hot Quantum Chromodynamics, by the strong sphaleron configurations. In particular, we study the curvature of the critical line at small μ5\mu_5, the effects of a finite quark mass and of a vector interaction. Moreover, we build the mixed phase at the first order phase transition line, and draw the phase diagram in the chiral density and temperature plane. We finally compute the full topological susceptibility in presence of a background of topological charge.Comment: 12 pages, 7 figures. Few references added, short discussion included. Final version appearing on Phys. Rev.

    Postoperative care in finger replantation. Our case-load and review of the literature

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    OBJECTIVE: Technical success of a finger replantation depends on several factors such as surgical procedure, type of injury, number of segments amputated, amputation level and individual patient factors. Among early complications that can occur in this type of surgery the onset of venous or arterial thrombosis is the most dreaded. Local irrigating solutions, oral and intravenous anticoagulants, thrombolytic agents, plasma expanders, vasodilating, and antiaggregant drugs are routinely used in patients undergoing microvascular procedures, but currently there is only a non-standardized practice based on anecdotal personal experience. MATERIALS AND METHODS: The aim of our study is to review selected literature relating to perioperative therapy in microsurgical digital replantation. We also report our case-load of 16 patients with finger avulsion describing our particular protocol for postoperative anticoagulation and restoration of fluid and electrolyte balance. RESULTS: Following our daily pharmacological protocol, the postoperative course of the replanted fingers was uneventful. The survival rate for finger replantations performed was 100% (n = 16) with no need for surgical revisions. CONCLUSIONS: The association Dextran-40/Heparin/fluids in the proposed standardized pro-weight pharmacological protocol is an optimal postoperative prophylactic/therapeutic plan to reduce the incidence of endovascular thrombosis after replantation, so ensuring high rate of success in microvascular surgery

    The layered structure of company share networks

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    We present a framework for the analysis of corporate governance problems using network science and graph algorithms on ownership networks. In such networks, nodes model companies/shareholders and edges model shares owned. Inspired by the widespread pyramidal organization of corporate groups of companies, we model ownership networks as layered graphs, and exploit the layered structure to design feasible and efficient solutions to three key problems of corporate governance. The first one is the long-standing problem of computing direct and indirect ownership (integrated ownership problem). The other two problems are introduced here: computing direct and indirect dividends (dividend problem), and computing the group of companies controlled by a parent shareholder (corporate group problem). We conduct an extensive empirical analysis of the Italian ownership network, which, with its 3.9M nodes, is 30× the largest network studied so far
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