1,612 research outputs found

    Application Of Safety And Security Principles To Flood Event Management In Highly Populated Urban Areas

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    This paper refers to non-structural actions which are to be carried out on the Arno river basin (Italy). In particular the town of Florence is considered where 56 catastrophic flood events have been recorded in the last 1000 years, the latter in 1966 with damages estimated at 10,000 billion euros. A huge system of structural works is presently being carried out planned to the 200-year return period event in the next ten years. To manage the present and future residual risk, specific safety plans have been provided at the scale of single buildings in order to give residents an effective instrument to prevent and protect them from the major flooding risk. This paper illustrates how safety and security principles can be applied to the management of a flood event at the scale of several thousands of square kilometres. A specific Security Plan and, if needed, a Recovery Plan is linked to each building which is potentially subject to flooding. Based on analytical hazard assessment and mapping, techniques to improve or increase the safety-level as well as appropriated information are described. These local scale plans are interfaced with civil protection and disaster management plans at the regional scale by suitable procedures. Keywords: risk assessment, flood event, security plan, recovery plan, signs, procedures, building. 1 Introduction A study for a plan in order to provide the residents of the area of the Arno River basin (and in future perspective all the residents) with one useful instrument t

    Bipartite quantum states and random complex networks

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    We introduce a mapping between graphs and pure quantum bipartite states and show that the associated entanglement entropy conveys non-trivial information about the structure of the graph. Our primary goal is to investigate the family of random graphs known as complex networks. In the case of classical random graphs we derive an analytic expression for the averaged entanglement entropy Sˉ\bar S while for general complex networks we rely on numerics. For large number of nodes nn we find a scaling Sˉclogn+ge\bar{S} \sim c \log n +g_e where both the prefactor cc and the sub-leading O(1) term geg_e are a characteristic of the different classes of complex networks. In particular, geg_e encodes topological features of the graphs and is named network topological entropy. Our results suggest that quantum entanglement may provide a powerful tool in the analysis of large complex networks with non-trivial topological properties.Comment: 4 pages, 3 figure

    Reversible melting and equilibrium phase formation of (Bi,Pb)2Sr2Ca2Cu3O10+d

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    The decomposition and the reformation of the (Bi,Pb)2Sr2Ca2Cu3O10+d (?Bi,Pb(2223)?) phase have been investigated in-situ by means of High-Temperature Neutron Diffraction, both in sintered bulk samples and in Ag-sheathed monofilamentary tapes. Several decomposition experiments were performed at various temperatures and under various annealing atmospheres, under flowing gas as well as in sealed tubes, in order to study the appropriate conditions for Bi,Pb(2223) formation from the melt. The Bi,Pb(2223) phase was found to melt incongruently into (Ca,Sr)2CuO3, (Sr,Ca)14Cu24O41 and a Pb,Bi-rich liquid phase. Phase reformation after melting was successfully obtained both in bulk samples and Ag-sheathed tapes. The possibility of crystallising the Bi,Pb(2223) phase from the melt was found to be extremely sensitive to the temperature and strongly dependent on the Pb losses. The study of the mass losses due to Pb evaporation was complemented by thermogravimetric analysis which proved that Pb losses are responsible for moving away from equilibrium and therefore hinder the reformation of the Bi,Pb(2223) phase from the melt. Thanks to the full pattern profile refinement, a quantitative phase analysis was carried out as a function of time and temperature and the role of the secondary phases was investigated. Lattice distortions and/or transitions were found to occur at high temperature in Bi,Pb(2223), Bi,Pb(2212), (Ca,Sr)2CuO3 and (Sr,Ca)14Cu24O41, due to cation diffusion and stoichiometry changes. The results indicate that it is possible to form the Bi,Pb(2223) phase from a liquid close to equilibrium conditions, like Bi(2212) and Bi(2201), and open new unexplored perspectives for high-quality Ag-sheathed Bi,Pb(2223) tape processing.Comment: 45 pages (including references,figures and captions), 13 figures Submitted to Supercond. Sci. Techno

    A note on perturbation series in supersymmetric gauge theories

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    Exact results in supersymmetric Chern-Simons and N=2 Yang-Mills theories can be used to examine the quantum behavior of observables and the structure of the perturbative series. For the U(2) x U(2) ABJM model, we determine the asymptotic behavior of the perturbative series for the partition function and write it as a Borel transform. Similar results are obtained for N=2 SU(2) super Yang-Mills theory with four fundamental flavors and in N=2* super Yang-Mills theory, for the partition function as well as for the expectation values for Wilson loop and 't Hooft loop operators (in the 0 and 1 instanton sectors). In all examples, one has an alternate perturbation series where the coefficient of the nth term increases as n!, and the perturbation series are Borel summable. We also calculate the expectation value for a Wilson loop operator in the N=2* SU(N) theory at large N in different regimes of the 't Hooft gauge coupling and mass parameter. For large masses, the calculation reproduces the running gauge coupling for the pure N=2 SYM theory.Comment: 28 pages. V2: minor additions and reference adde

    Wilson Loops in N=2 Super-Yang-Mills from Matrix Model

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    We compute the expectation value of the circular Wilson loop in N=2 supersymmetric Yang-Mills theory with N_f=2N hypermultiplets. Our results indicate that the string tension in the dual string theory scales as the logarithm of the 't Hooft coupling.Comment: 37 pages, 9 figures; v2: Numerical factors corrected, simple derivation of Wilson loop and discussion of continuation to complex lambda added; v3: instanton partition function re-analyzed in order to take into account a contribution of the hypermultiplet
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