Search results for "METODI"
showing 10 items of 940 documents
Noise stabilization effects in models of interdisciplinary physics
2009
Metastability is a generic feature of many nonlinear systems, and the problem of the lifetime of metastable states involves fundamental aspects of nonequilibrium statistical mechanics. The investigation of noise-induced phenomena in far from equilibrium systems is one of the approaches used to understand the behaviour of physical and biological complex systems. The enhancement of the lifetime of metastable states through the noise enhanced stability effect and the role played by the resonant activation phenomenon will be discussed in models of interdisciplinary physics: (i) polymer translocation dynamics; (ii) transient regime of FitzHugh-Nagumo model; (iii) market stability in a nonlinear …
Stabilization Effects of Dichotomous Noise on the Lifetime of theSuperconducting State in a Long Josephson Junction
2015
We investigate the superconducting lifetime of a long overdamped current-biased Josephson junction, in the presence of telegraph noise sources. The analysis is performed by randomly choosing the initial condition for the noise source. However, in order to investigate how the initial value of the dichotomous noise affects the phase dynamics, we extend our analysis using two different fixed initial values for the source of random fluctuations. In our study, the phase dynamics of the Josephson junction is analyzed as a function of the noise signal intensity, for different values of the parameters of the system and external driving currents. We find that the mean lifetime of the superconductive…
B-K-parameter from N-f=2 twisted mass lattice QCD
2011
We present an unquenched N-f = 2 lattice computation of the B-K parameter which controls K-0 - (K) over bar (0) oscillations. A partially quenched setup is employed with two maximally twisted dynamical (sea) light Wilson quarks, and valence quarks of both the maximally twisted and the Osterwalder-Seiler variety. Suitable combinations of these two kinds of valence quarks lead to a lattice definition of the B-K parameter which is both multiplicatively renormalizable and O(a) improved. Employing the nonperturbative RI-MOM scheme, in the continuum limit and at the physical value of the pion mass we get B-K(RGI) = 0.729 +/- 0.030, a number well in line with the existing quenched and unquenched d…
A sizing approach for stand-alone hybrid photovoltaic-wind-battery systems: A Sicilian case study
2018
Abstract Solar and wind energy are the two most available renewable energy resources in the world. In this paper, a high-resolution analysis that allows sizing a hybrid photovoltaic-wind turbine-battery banks has been carried out. The analysis aims to minimize the annualized cost of the systems satisfying two reliability constraints. The solution has been obtained numerically by means of an iterative technique. The decision variables are the photovoltaic area, wind turbine radius, and battery capacity. A high-resolution model, based on fuzzy logic inference system, has been developed to evaluate the number of active occupants and the domestic electricity consumption. In order to allow a mor…
LE METODICHE ANALITICHE
2022
Il processo analitico è frutto di una serie di tappe fondamentali (Fig. 13.1) che devono permettere di raggiungere lo scopo prefissato: ottenere un’informazione puntuale sul campione sottoposto ad analisi. Le scelte legate alla procedura di campionamento, di pretrattamento del campione e del metodo di analisi sono fortemente influenzate dal tipo di matrice, dal tipo di analita o del parametro da determinare e dal grado di incertezza tollerabile sul risultato finale affinché sia conforme alle esigenze normative, disciplinari o di indagine scientifica. Il campione, inteso come quantità di materia che si sottopone ad analisi, deve essere un’aliquota rappresentativa e omogenea della biomassa ne…
Political risks: the “red shift” in debt sustainability analysis
2020
Political stability and economic policy uncertainty can be key determinants of sovereign debt dynamics, and we show how they can be incorporated in debt sustainability analysis. We distinguish between short-term ambiguity and long-term uncertainty about political risk factors, and using a combination of narrative scenarios and calibrated probabilistic scenarios we obtain a comprehensive heatmap of high-risk debt dynamics. We use Italy as an interesting case study and demonstrate a “red shift” in the assessment of vulnerabilities when accounting for political risks. Ignoring these risks can lead to excessive optimism and wrong decisions.
Supersymmetric Indices of 3d S-fold SCFTs
2019
Enhancement of global symmetry and supersymmetry in the infrared is one of the most intriguing phenomena in quantum field theory. We investigate such phenomena in a large class of three dimensional superconformal field theories, known as the S-fold SCFTs. Supersymmetric indices are computed for a number of theories containing small rank gauge groups. It is found that indices of several models exhibit enhancement of supersymmetry at the superconformal fixed point in the infrared. Dualities between S-fold theories that have different quiver descriptions are also analysed. We explore a new class of theories with a discrete global symmetry, whose gauge symmetry in the quiver has a different glo…
Costruzione dei rilevati stradali e ferroviari: valutazione delle metodologie di progetto delle terre trattate con calce
2010
Nella costruzione delle opere civili e, soprattutto, delle infrastrutture di trasporto, elemento qualificante per la minimizzazione degli impatti economici ed ambientali è l’adozione del trattamento con calce dei terreni argillosi di scavo, di per sé non idonei ad essere impiegati nei manufatti in terra, e la loro utilizzazione - previo trattamento con calce, appunto - per la costruzione di rilevati ed altre opere in terra. La tecnica del trattamento con calce delle terre argillose permette di ottenere diversi vantaggi di ordine tecnico, economico ed ambientale. I progressi tecnologici conseguiti negli ultimi decenni, particolarmente per quanto riguarda gli studi di progetto, i mezzi di can…
Numerical prediction of ventilated planing flat plates for the design of Air Cavity Ships
2017
In recent years, a great world issue is the respect for the environment. Each researcher, in his competence field, proposes new technologies and new approaches in order to reduce the environmental impact of a product or of an industrial process. In the naval field, the main way in order to reduce the environmental impact of the ship during the navigation is the reduction of the drag resistance and so the reduction of requested power. There are many ways in order to obtain a reduction of drag. This paper investigates, with a preliminary numerical study by means of Computational Fluid Dynamics (CFD), the Air Cavity Ships technology (ACS). A first part of the paper concerns the study of the ri…
The synovial joints of the human foot.
2007
The human foot is considered an organ with an assortment of tissues with different morphological characteristics and well defined limits, but effectively has a simple functionality when static that becomes extremely complex when in movement. Its complex structure, comprised of an elastic and resistant skin covering a bone framework, joints, muscles, tendons, veins and nerves, can be compared to an efficient mechanical assembly. After a long and extraordinary evolutive journey, the human foot has undergone numerous changes to perfect its function; it has lost most of its grabbing function whilst gaining new characteristics that have ultimately allowed the modern man to stand upright. The com…