294 research outputs found

    Single-phase power line conditioning with unity power factor under distorted utility voltage

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    The paper proposes a control method of a single-phase active power line conditioner (APLC) aimed at correcting the power factor of linear and non-linear loads supplied by distorted voltage utility. The method, that is based on the single-phase p-q theory and utilizes a third-order sinusoidal signal integrator, gets utility unity power factor and, at the same time, overcomes the shortcomings of the solutions pursuing utility sinusoidal current, namely the possible onset of un-damped resonance phenomena and the reduction in the energy delivery capabilities; moreover, the method makes the power factor correction robust against the supply distortion. The excellent performance of the method is substantiated by testing it by means of a hardware-in-the-loop setup

    A review of power electronics equipment for all-electric ship MVDC power systems

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    Medium Voltage DC (MVDC) distribution Power Systems for all-electric ships (AES) can be regarded as functionally composed of three subsystems, namely the power sources, the load centers and the distribution network. Extensive use of power electronics is required for connecting power sources and load centers to the MVDC bus and for protecting the MVDC power system through properly placed DC circuit breakers. In this paper, an overview is given of the power electronics equipment found in the literature and on the market that could be suitable for use in future AES MVDC power systems. Some industrial experiences regarding DC generator systems, energy storage apparatus and solid-state DC circuit breaker prototypes are reported in the paper as examples of state-of-the-art realizations. Different DC/DC converters, which can be employed as solid-state transformers, are also discussed and a structure obtained by combining them is proposed

    Research and Teaching in Higher Education: Complements or Substitutes?

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    In this note we use unique data from Bar-Ilan University, over a period of four years (2005-2008), to estimate simultaneous equations with regard to the relationship between publications and teaching loads. The study shows that students studying for a bachelor's degree are a liability while PhD students are an asset in terms of publications. Those studying for a master's degree may be a liability or an asset depending on the department characteristics. Increasing the number of faculty members increases publications however it may not increase the publications per capita and is department specific

    Design and simulation of a vehicle-To-grid system

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    Batteries of electric vehicles have to be charged by power electronic converters connected to the electric grid. If these power converters are bidirectional they can be exploited to act in support to the grid operation, thus realizing the so called vehicle-To-grid (V2G) systems. At the University of Trieste an experimental V2G apparatus is under construction. Its control system has been developed and the first simulation tests has been performed. The paper describes the V2G experimental apparatus with its control system and reports the results of the preliminary simulation tests

    Computational analysis of anti-HIV-1 antibody neutralization panel data to identify potential functional epitope residues

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    Advances in single-cell antibody cloning methods have led to the identification of a variety of broadly neutralizing anti–HIV-1 antibodies. We developed a computational tool (Antibody Database) to help identify critical residues on the HIV-1 envelope protein whose natural variation affects antibody activity. Our simplifying assumption was that, for a given antibody, a significant portion of the dispersion of neutralization activity across a panel of HIV-1 strains is due to the amino acid identity or glycosylation state at a small number of specific sites, each acting independently. A model of an antibody’s neutralization IC_(50) was developed in which each site contributes a term to the logarithm of the modeled IC_(50). The analysis program attempts to determine the set of rules that minimizes the sum of the residuals between observed and modeled IC_(50) values. The predictive quality of the identified rules may be assessed in part by whether there is support for rules within individual viral clades. As a test case, we analyzed antibody 8ANC195, an anti-glycoprotein gp120 antibody of unknown specificity. The model for this antibody indicated that several glycosylation sites were critical for neutralization. We evaluated this prediction by measuring neutralization potencies of 8ANC195 against HIV-1 in vitro and in an antibody therapy experiment in humanized mice. These experiments confirmed that 8ANC195 represents a distinct class of glycan-dependent anti–HIV-1 antibody and validated the utility of computational analysis of neutralization panel data

    Exploring the role of respiratory microbiome in lung cancer: A systematic review

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    Giving the potential contribute in cancer initiation and progression, lung microbiota represents a promising topic in cancer research, although still unexplored. We performed a systematic literature search to identify clinical studies evaluating lung microbiota composition, its correlation with lung cancer patients’ clinico-pathological features and prognosis. Of the identified 370 studies, 21 were eligible and included. Although studies were heterogeneous, lung cancer resulted to be enriched in peculiar microbial communities, with differences in composition and diversity according to clinico-pathological parameters. Few studies explored how lung microbiota influences cancer outcome. In light of these findings and borrowing the suggestions coming from gut microbiota, we speculate that respiratory microbiome may influence pathogenesis, progression and outcome of lung cancer. Taking advantage of the experience of chronical lung diseases, prospective studies should be designed to evaluate lung microbiota changes throughout any phase of lung cancer course, particularly with the advent of immunotherapy as pivotal treatment

    On the absence of bound-state stabilization through short ultra-intense fields

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    We address the question of whether atomic bound states begin to stabilize in the short ultra-intense field limit. We provide a general theory of ionization probability and investigate its gauge invariance. For a wide range of potentials we find an upper and lower bound by non-perturbative methods, which clearly exclude the possibility that the ultra intense field might have a stabilizing effect on the atom. For short pulses we find almost complete ionization as the field strength increases.Comment: 34 pages Late

    On the Influence of Pulse Shapes on Ionization Probability

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    We investigate analytical expressions for the upper and lower bounds for the ionization probability through ultra-intense shortly pulsed laser radiation. We take several different pulse shapes into account, including in particular those with a smooth adiabatic turn-on and turn-off. For all situations for which our bounds are applicable we do not find any evidence for bound-state stabilization.Comment: 21 pages LateX, 10 figure
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