153 research outputs found
Parameter Identification of a PV Source Dynamic Model with Piecewise-Linear Circuit-Based Approach
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ODEF: an interactive tool for optimized design of EMI filters
The impact of EMI filters on volume and weight of power converters is significant. For this reason, filter’s size optimization is a strategic step towards the improvement of the power converter’s power density. An EMI filter design that follows a conventional procedure does not guarantee the selection of components/configuration leading to the best power density. Therefore, in order to help EMI engineers and scientists in pursuing a fast and effective choice of optimal discrete EMI filter components and configuration, a novel tool is proposed in this paper, namely ODEF (Optimized Design of EMI Filters). ODEF is an interactive software application running in Matlab® environment. It suitably improves a previously validated EMI filter design procedure that extends the conventional filter design method in order to achieve optimal power density. Features and operation of ODEF tool are illustrated. Moreover, the experimental assessment of an input EMI filter, designed according to the optimized procedure for an inverter-fed induction motor drive, is performed
Optimized design of high power density EMI filters for power electronic converters
Nowadays, power density of power converters and related EMI filters is gaining more and more attention. This severely impacts on the design constraints in several application domains. A conventional design of the EMI filter does not guarantee the selection of components/configuration leading to the best power density. For this reason, an optimized design procedure of discrete EMI filters in terms of power density is proposed in this paper. It is based on a previously developed rule-based design procedure, introducing here additional features to obtain a more effective optimization of EMI filter's power density. The proposed approach has been validated in terms of EMI filter's performance and size reduction, by a comparison between an EMI filter designed using the optimized procedure and a conventionally designed one, for two different case studies
Computer aided optimal design of high power density EMI filters
Power density of power converter systems is becoming an increasing crucial design constraint for a wide range of technical applications. Size reduction of EMI filter in power converters is an important challenge due to its significant impact on the overall converter volume and weight. In order to take on this issue, a computer aided procedure for a fast selection of optimal discrete EMI filter components and layout is described in this paper. The proposed technique is a rule-based automatic procedure based on a suitable database that considers the commercially available data sheets of passive components (e.g. magnetic cores, capacitors). It allows the minimization of the filter’s volume and therefore the improvement of the converter’s power density. The size and the performance of an EMI filter designed by using the proposed procedure, have been compared with those of a conventionally designed one. The comparison demonstrates the effectiveness of the proposed method
Risultato di valorizzazione applicativa: progettazione e realizzazione di un prototipo di sensore wireless per il monitoraggio di carichi elettrici in ambiente Smart Building
Oggetto del presente lavoro è stata la progettazione e realizzazione di un prototipo di sensore
wireless a basso costo per il monitoraggio di carichi elettrici in ambiente Smart Building, capace di
inviare dati ad un sistema remoto (ad esempio un EMS) mediante una comune connessione WiFi.
L’attività si inquadra nell’ambito di una collaborazione scientifica tra l’Istituto di Studi sui
Sistemi Intelligenti per l’Automazione (ISSIA) del Consiglio Nazionale delle Ricerche (CNR) e il
Dipartimento di Matematica e Informatica (DMI) dell’Università degli Studi di Palermo (UNIPA).
Il prototipo è stato realizzato interfacciando opportunamente alcuni dispositivi hardware
commerciali, aggiungendo gli opportuni circuiti per il condizionamento dei segnali da acquisire e
scrivendo il codice per l’implementazione del firmware del sensore wireless (per l’invio dei dati) e
del client remoto (per la ricezione dei dati)
Giorgio Vasari a Palazzo Abatellis. Percorsi del Rinascimento in Sicilia
La mostra si inserisce nell'ambito delle celebrazioni per i 500 anni della nascita di Giorgio Vasari (1511-2011), ricorrenza che, nel corso dell'anno, \ue8 stata oggetto di numerosi eventi culturali italiani e internazionali. L'iniziativa nasce dalla collaborazione tra la Biblioteca Centrale della Regione siciliana "A. Bombace", la sezione "Sfera" del Dipartimento di Architettura dell'Universit\ue0 degli Studi di Palermo, e la Galleria Interdisciplinare Regionale della Sicilia, istituzione che custodisce, nella prestigiosa sede di Palazzo Abatellis, due grandi dipinti su tavola di Vasari, costituenti le ricurve parti laterali del trittico della "Caduta della manna" realizzato nel 1545 per il refettorio di Santa Maria di Monteoliveto a Napoli. Le lunette vasariane, esposte in modo permanente dal 2009 ma ancora quasi del tutto sconosciute a studiosi e pubblico, per l'occasione sono state ricollocate secondo gli originali rapporti dimensionali con il perduto quadro centrale e poste in relazione con il disegno preparatorio dello stesso Vasari, oggi custodito presso l'Ecole nationale superieure des beaux-arts di Parigi. Il percorso analitico, che si \ue8 avvalso anche del prezioso contributo di Claudia Conforti, tra le pi\uf9 autorevoli studiose dell'artista aretino, e delle competenze tecniche dell'Associazione culturale LapiS, \ue8 stato svolto secondo tre tematiche connesse alla poliedrica attivit\ue0 vasariana e al suo contesto culturale: la pittura e l'arte del disegno, la produzione letteraria, l'architettura. Al patrimonio pittorico e grafico della Galleria, riconducibile a quella che lo stesso Vasari definisce \uabmaniera moderna\ubb, sono stati quindi associati preziosi volumi a stampa, a partire dalla rara edizione del 1568 delle "Vite de' pi\uf9 eccellenti architetti, pittori e scultori italiani", e pannelli illustrativi riferiti a opere siciliane di architetti e scultori citati nelle "Vite" vasariane, costituenti alcune pregnanti testimonianze del Rinascimento in Sicili
New Strong-Field QED Effects at ELI: Nonperturbative Vacuum Pair Production
Since the work of Sauter, and Heisenberg, Euler and K\"ockel, it has been
understood that vacuum polarization effects in quantum electrodynamics (QED)
predict remarkable new phenomena such as light-light scattering and pair
production from vacuum. However, these fundamental effects are difficult to
probe experimentally because they are very weak, and they are difficult to
analyze theoretically because they are highly nonlinear and/or nonperturbative.
The Extreme Light Infrastructure (ELI) project offers the possibility of a new
window into this largely unexplored world. I review these ideas, along with
some new results, explaining why quantum field theorists are so interested in
this rapidly developing field of laser science. I concentrate on the
theoretical tools that have been developed to analyze nonperturbative vacuum
pair production.Comment: 20 pages, 9 figures; Key Lecture at the ELI Workshop and School on
"Fundamental Physics with Ultra-High Fields", 29 Sept - 2 Oct. 2008,
Frauenworth Monastery, Germany; v2: refs updated, English translations of
reviews of Nikishov and Ritu
Prevention of congenital malformations and other adverse pregnancy outcomes with 4.0 mg of folic acid : community-based randomized clinical trial in Italy and the Netherlands
Background: In 2010 a Cochrane review confirmed that folic acid (FA) supplementation prevents the first- and second-time occurrence of neural tube defects (NTDs). At present some evidence from observational studies supports the hypothesis that FA supplementation can reduce the risk of all congenital malformations (CMs) or the risk of a specific and selected group of them, namely cardiac defects and oral clefts. Furthermore, the effects on the prevention of prematurity, foetal growth retardation and pre-eclampsia are unclear.Although the most common recommendation is to take 0.4 mg/day, the problem of the most appropriate dose of FA is still open.The aim of this project is to assess the effect a higher dose of peri-conceptional FA supplementation on reducing the occurrence of all CMs. Other aims include the promotion of pre-conceptional counselling, comparing rates of selected CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age, abruptio placentae.Methods/Design: This project is a joint effort by research groups in Italy and the Netherlands. Women of childbearing age, who intend to become pregnant within 12 months are eligible for the studies. Women are randomly assigned to receive 4 mg of FA (treatment in study) or 0.4 mg of FA (referent treatment) daily. Information on pregnancy outcomes are derived from women-and-physician information.We foresee to analyze the data considering all the adverse outcomes of pregnancy taken together in a global end point (e.g.: CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age). A total of about 1,000 pregnancies need to be evaluated to detect an absolute reduction of the frequency of 8%. Since the sample size needed for studying outcomes separately is large, this project also promotes an international prospective meta-analysis.Discussion: The rationale of these randomized clinical trials (RCTs) is the hypothesis that a higher intake of FA is related to a higher risk reduction of NTDs, other CMs and other adverse pregnancy outcomes. Our hope is that these trials will act as catalysers, and lead to other large RCTs studying the effects of this supplementation on CMs and other infant and maternal outcomes.Trial registration: Italian trial: ClinicalTrials.gov Identifier: NCT01244347.Dutch trial: Dutch Trial Register ID: NTR3161
Measurement of vector boson production cross sections and their ratios using pp collisions at √s = 13.6 TeV with the ATLAS detector
Abstract available from publisher's website
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