Search results for "IMPIANTI"
showing 10 items of 797 documents
Modelling and simulation of gas-liquid hydrodynamics in mechnically stirred tanks
2007
Abstract Computational fuid dynamics (CFD) is an increasingly important tool for carrying out realistic simulations of process equipment. In the case of multiphase systems the development of CFD models is less advanced than for single-phase systems. In the present work CFD simulations of gas–liquid stirred tanks are reported. An Eulerian–Eulerian multi-fluid approach is used in conjunction with the simplest two-phase extension of the k–ɛ turbulence model. All bubbles are assumed to share the same size. The effect of inter-phase forces on simulation results is separately considered. As concerns drag, it is shown that the sole parameter needed to characterize the dispersed phase behaviour is …
Thermal-hydraulic behaviour of the DEMO divertor plasma facing components cooling circuit
2017
Abstract Within the framework of the Work Package DIV 1 – “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by ENEA and University of Palermo to investigate the thermal-hydraulic performances of the DEMO divertor cassette cooling system. A comparative evaluation study has been performed considering three different options for the cooling circuit layout of the divertor Plasma Facing Components (PFCs). The potential improvement in the thermal-hydraulic performance of the cooling system, to be achieved by modifying cooling circuit layout, has been also assessed and discussed in terms of optimization strategy. The research acti…
The design of the DONES lithium target system
2019
Abstract In the framework of the EU fusion roadmap implementing activities, an accelerator-based Li(d,xn) neutron source called DONES (Demo-Oriented early NEutron Source) is being designed within the EUROfusion Work Package Early Neutron Source as an essential irradiation facility for testing candidate materials for DEMO reactor and future fusion power plants. DONES will employ a high speed liquid lithium jet struck by a 125 mA, 40 MeV deuteron beam to generate the intense neutron flux used to irradiate the material samples up to the desired level of displacement damage (˜10 dpa/fpy for iron in 0.3 l) and He production rates (˜10-13 appm He/dpa). In order to rapidly achieve a sound and stab…
Parametric study of the influence of First Wall cooling water on the Water Cooled Lithium Lead Breeding Blanket nuclear response
2019
Abstract In the framework of EUROfusion Work Package International Cooperation R&D activities, a close collaboration has been started among University of Palermo, ENEA Brasimone and ENEA Frascati for the development of the Water Cooled Lithium Lead (WCLL) Breeding Blanket (BB) concept. In this context, a research campaign has been carried out at the University of Palermo in order to investigate the influence of First Wall (FW) cooling water configuration on the nuclear response of the WCLL BB under irradiation in EU-DEMO, in order to gain useful indications for the WCLL BB pre-conceptual designs. To this end, three-dimensional nuclear analyses have been performed by MCNP5 v. 1.6 Monte Carlo…
Improving the logistic process of orders dispatching through a multi-criteria decision-making perspective
2020
International audience; Far from being a mere production-oriented mission, competition among companies has to be considered as a much wider concept, largely based on effective supply chain management. Implementing suitable supply chain strategies is indeed crucial for enterprises seeking to strengthen their own position in the market against their competitors. With this recognition, one of the main issue in the logistic field is the suppliers and orders management, that is a complex decision-making problem depending on a wide set of aspects mutually correlated and often conflicting each other. This is the reason why assuming a Multi-Criteria Decision-Making (MCDM) perspective is useful to d…
A Combined Fuzzy-SEM Evaluation Approach to Identify the Key Drivers of the Academic Library Service Quality in the Digital Technology Era: An Empiri…
2017
A conceptual model of the Academic Library (AL) service quality is hypothesized in the present article, and then validated and analyzed by a novel evaluation approach. Specifically, the conceptual model integrates the fundamental attributes of the canonical AL service together with those more relevant of the new and widely considered AL Electronic Service (e-services). As concerns the evaluation approach, it incorporates the Fuzzy Sets Theory (FST) so as to deal with the students’ uncertainty over their own judgments on the AL service quality and a Structural Equation Model (SEM) to validate the conceptual model and to determine the key drivers of the AL service quality. The effectiveness o…
Fuzzy risk analysis of a modern gamma-ray industrial irradiator
2011
Fuzzy fault tree analyses were used to investigate accident scenarios that involve radiological exposure to operators working in industrial gamma-ray irradiation facilities. The HEART method, a first generation human reliability analysis method, was used to evaluate the probability of adverse human error in these analyses. This technique was modified on the basis of fuzzy set theory to more directly take into account the uncertainties in the error-promoting factors on which the methodology is based. Moreover, with regard to some identified accident scenarios, fuzzy radiological exposure risk, expressed in terms of potential annual death, was evaluated. The calculated fuzzy risks for the exa…
Processi innovativi e sostenibili per il trattamento di rifiuti e acque reflue mediante l’utilizzo di acqua supercritica
2022
Il lavoro presentato in questa tesi è basato principalmente sullo sfruttamento dei processi termochimici in presenza di acqua supercritica per lo smaltimento dei rifiuti. Dipendentemente dalla tipologia di questi ultimi è possibile utilizzare processi diversi per scopi diversi. Nell’ottica di una completa distruzione delle componenti inquinanti presenti nel refluo è stato preso in considerazione un trattamento di ossidazione in acqua supercritica (SCWO); se invece l’obiettivo è quello di valorizzare uno scarto è possibile sfruttare il processo di gassificazione in acqua supercritica (SCWG). Dopo una breve introduzione per inquadrare il problema dei rifiuti con gli attuali metodi di trattame…
Biochemical methane potential (BMP) of solid organic substrates: evaluation of anaerobic biodegradability using data from an international interlabor…
2011
Background: This paper describes results obtained for different participating research groups in an interlaboratory study related to biochemical methane potential (BMP). In this research work, all experimental conditions influencing the test such as inoculum, substrate characteristics and experimental conditions were investigated. The study was performed using four substrates: three positive control substrates (starch, cellulose and gelatine), and one raw biomass material (mung bean) at two different inoculum to substrate ratios (ISR). Results: The average methane yields for starch, cellulose, gelatine and mung bean at ISR of 2 and 1 were 350 ± 33, 350 ± 29, 380 ± 42, 370 ± 36 and 370 ± 35 …
La valutazione delle attività neurodidattiche. Fondamenti, tecniche e strumenti.
2022
Le attività neurodidattiche si fondano sulla commistione tra le Scienze dell’Educazione e le Neuroscienze. Oggi, il cammino intrapreso da quest’ambito di ricerca intende fornire preziosi apporti alla prassi educativo-didattica; tuttavia, se da un lato esso registra un grande fervore sia in ambito nazionale sia soprattutto nel panorama internazionale, dall’altro stenta a convertire le nuove consapevolezze apprese in solide basi del proprio percorso. Se il Brain-based learning comincia a campeggiare nel contesto didattico italiano, è parimenti vero che la formazione all’utilizzo dei modelli di attività neurodidattiche richiede l’implementazione della riflessione, della verifica continua delle…