Stima della matrice di correlazione per clutter compound-gaussian non stazionario

In questo lavoro ho elaborato i dati relativi al clutter di mare per testare le prestazioni del rivelatore NAMF (Normalized Adaptive Matching Filter) con l’obiettivo di verificare l’impatto della non stazionarietà spaziale e temporale del clutter sulle prestazioni del rivelatore. A questo scopo ho utilizzato due diversi stimatori della matrice di covarianza, in particolare lo stimatore fixed point e lo stimatore Banded-inverse di Tyler. Prima di effettuare il calcolo delle prestazioni è stata fatta una stima della PSD al variare della frequenza Doppler del bersaglio, per valutare dove fosse il picco di potenza del clutter e in che intervallo di frequenze fosse concentrata la potenza. Sono state riscontrate importanti differenze nella probabilità di falso allarme nella probabilità di rivelazione valutate sui dati teorici e i dati reali e per i due stimatori

Deactivation Pattern of a "Model" Ni/MgO Catalyst in the Pre-Reforming of n-Hexane †

The deactivation pattern of a "model" Ni/MgO catalyst in the pre-reforming of n-hexane with steam (T, 450 °C; P, 5–15 bar) is reviewed. The influence of the steam-to-carbon ratio (S/C, 1.5–3.5) on the rate of catalyst fouling by coking is ascertained. Catalyst fouling leads to an exponential decay in activity, denoting 1st-order dependence of the coking process on active sites availability. Hydrogen hinders the coking process, though slight activity decay is due to sintering of the active Ni phase. Deactivation by thiophene causes a sharp, almost linear, drop to nearly zero activity within only 6 h; this deactivation is likely due to dissociative adsorption of thiophene with subsequent strong, irreversible chemical adsorption of S-atoms on active Ni sites, i.e., irreversible poisoning. Modeling of activity decay curves (α, at/a0) by proper kinetic equations allows assessing the effects of temperature, pressure, S/C, H2 and thiophene feed on the deactivation pattern of the model Ni/MgO catalyst by coking, sintering, and poisoning phenomena

Operational modal analysis of a spar-type floating platform using frequency domain decomposition method

System identification of offshore floating platforms is usually performed by testing small-scale models in wave tanks, where controlled conditions, such as still water for free decay tests, regular and irregular wave loading can be represented. However, this approach may result in constraints on model dimensions, testing time, and costs of the experimental activity. For such reasons, intermediate-scale field modelling of offshore floating structures may become an interesting as well as cost-effective alternative in a near future. Clearly, since the open sea is not a controlled environment, traditional system identification may become challenging and less precise. In this paper, a new approach based on Frequency Domain Decomposition (FDD) method for Operational Modal Analysis is proposed and validated against numerical simulations in ANSYS AQWA v.16.0 on a simple spar-type structure. The results obtained match well with numerical predictions, showing that this new approach, opportunely coupled with more traditional wave tanks techniques, proves to be very promising to perform field-site identification of the model structures

Progress on the experimental set-up for the testing of a floating offshore wind turbine scaled model in a field site

This document describes design and realization of a small-scale field experiment on a 1:30 model of spar floating support structure for offshore wind turbines. The aim of the experiment is to investigate the dynamic behaviour of the floating wind turbine under extreme wave and parked rotor conditions. The experiment has been going on in the Natural Ocean Engineering Laboratory of Reggio Calabria (Italy). In this article, all the stages of the experimental activity are presented, and some results are shown in terms of motions and response amplitude operators. Finally, a comparison with corresponding results obtained using ANSYS AQWA software package is shown, and conclusions are drawn. The presented experimental set-up seems promising to test offshore floating structures for marine renewable energy at a relatively large scale in the Natural Ocean Engineering Laboratory field site

A simulation/optimization model for selecting infrastructure alternatives in complex water resource systems

The paper introduces a simulation/optimization procedure for the assessment and the selection of infrastructure alternatives in a complex water resources system, i.e. in a multisource (reservoirs) multipurpose bulk water supply scheme. An infrastucture alternative is here a vector X of n decision variables describing the candidate expansions/new plants/water transfers etc. Each parameter may take on a discrete number of values, with its own investment cost attached. The procedure uses genetic algorithms for the search of the optimal vector X through operators mimicking the mechanisms of natural selection. For each X, the value of the objective function (O.F.) is assessed via a simulation model. Simulation is necessary as the O.F. contains, besides investment costs, also incremental operation costs and benefits that depend on the incremental water amounts which the alternative can provide. The simulation model transforms a thirty-year hydrologic input at daily/monthly scale in water allocations, accounting for the usual non-negativity constraints and using some simple, sytem-specific rules aimed at reducing spills and at sharing water deficits among demand centres. Different O.Fs and constraints have been tested, such as incremental financial cost/benefit minimization under various maximum water deficit constraints scenarios or cost/benefit mimization including scarcity costs. This latter approach has the advantage of implicitly allowing for the magnitude of deficits, but requires the assessment of deficit-scarcity cost relationships. The application of the procedure to a water resources system in south-western Sicily shows that the model is able to converge to results that are consistent with the planning options expressed by the selected O.Fs

ANALISI DEL COMPORTAMENTO AD INDENTAZIONE IN TRAVI SANDWICH IN COMPOSITO CON ANIMA IN SCHIUMA POLIMERICA

Nel presente lavoro si propone una estensione dei modelli basati sulla teoria delle travi vincolate su una fondazione cedevole di tipo Winkler per lo studio del comportamento ad indentazione di travi sandwich in schiuma polimerica sollecitate da carichi concentrati. L’approccio proposto è in grado di considerare schiume polimeriche aventi comportamento a compressione di tipo non lineare. Sono derivate soluzioni analitiche in forma chiusa della curva di indentazione per anime in schiuma polimerica il cui comportamento a compressione è approssimabile con un andamento bi-lineare. In tal modo è possibile considerare comportamenti di softening o hardening della schiuma nel tratto post-elastico. Le previsioni dei modelli sviluppati sono confrontate con le curve di indentazione misurate su travi sandwich realizzate con schiume di poliammide e polistirene estruso. I modelli proposti migliorano la simulazione del processo di indentazione rispetto ai modelli classici basati su un comportamento a compressione della schiuma polimerica di tipo elastico-perfettamente plastico

Interleukin-1 blockade in recently decompensated systolic heart failure: study design of the recently decompensated heart failure anakinra response trial (RED-HART)

Heart Failure (HF) is a clinical syndrome characterized by dyspnea, fatigue, and poor exercise capacity due to impaired cardiac function. The incidence of HF is increasing and represents the leading cause of hospitalization in the United States among patients > 65 years of age. Neurohormonal blockade has proven to reduce morbidity and mortality; however the persistent toll of HF demonstrates the urgent need to continue to develop novel drugs that target other pathophysiological paradigms. The presence of inflammation in cardiovascular disease has been well-established and interleukin-1 (IL-1), the prototypical proinflammatory agent, has been shown in preclinical animal models to induce cardiac dysfunction. The current study will investigate the role of IL-1 as an inflammatory mediator of HF progression and investigate whether IL-1 blockade with anakinra, recombinant human IL-1 receptor antagonist, improves aerobic exercise performance in patients with recently decompensated systolic HF. This study will be composed of 3 treatment arms (20 patients each): 1) anakinra 100mg daily for 12 weeks; 2) anakinra 100mg daily for 2 weeks followed by placebo for 10 weeks; or 3) placebo for 12 weeks. All patients will be followed for at least 24 weeks. The co-primary endpoints will be placebo-corrected interval changes in peak oxygen consumption (VO2) and ventilatory efficiency (VE/VCO2 slope) measured by Cardiopulmonary Exercise Testing (CPX) after 2 weeks of anakinra treatment. Secondary endpoints will include interval changes in 1) CPX variables at 4, 12 and 24 weeks; 2) echocardiographic measures of cardiac dimension/function; 3) quality of life assessments; 4) inflammatory biomarkers; and 5) clinical outcome including days alive outside of the hospital and survival free of re-hospitalization for HF. The RED-HART study will be the first study to address the potential benefits of IL-1 blockade on aerobic exercise performance in patients with recently decompensated HF

From green-energy to green-logistics: a pilot study in an Italian port area

Abstract An ongoing two-year research is performing with the general objective to assess the feasibility of a system integrating the production of green-energy and its consumption inside and close to port areas for mobility services. The system is composed by two elements: (a) a "sea-to-grid" technological component harvesting and producing electrical energy from sea waves; and (b) a "green" logistic service based on the use of Fully Electric Vehicles (FEVs). A pilot study will be conducted near an Italian port area supporting passengers and freight mobility between a port and a backward (sub)-urban area. The proposed system is within the environmental goals set by the EU (Europe 2020 Strategy) and the Italian Government (National Energy Masterplan). Indeed, the energy-producing technology reduces dependence from traditional energy sources (coal, gas, oil) and consequently reduces their negative effects (greenhouse gases, air pollution, etc.). Considering that the energy is produced by sea waves, the system transfers the entire amount of produced (green) energy to the electric vehicles. The system will be experimented in a medium size urbanized area and the energy will be produced in a small size port