339 research outputs found
Self-Ignition of Aviation Fuels in Direct Injection Diesel Engines
No full textThe avio Diesel engine is believed to be an innovative, high efficient and powerful engine system in thr air transport. In this paper, the self-ignition of standard jet-fuels in a Diesel engine-like environment is studied. The jet-fuel ignition plays an important role of the entire combustion process to minimize the weight/power ratio, without compromising the high conversion efficiency and the low production of pollutants opf modern Diesel engines. The Shell auto-ignition model is used to simulate the Jet-A and JP-8 fuels auto-ignition. Ad-hoc model kinetic parameters are proposed. The results are compared with those available in the literature to show the accuracy of the proposed model constants
“Pecunia adsidua permutatione quodammodo extinguitur”. Spunti per una definizione del denaro nel dibattito su usura e povertà francescana
No full textIl saggio vuole mostrare come il dibattito sulla povertà francescana abbia potuto svolgere un ruolo nel passaggio da una concezione "metallistica" della moneta ad un approccio più astratto, non senza possibili ricadute sulla teoria medievale dell'usura. Il volume è a cura di R. Lambertini e L. Sile
Simulazione numerica bidimensionale di turbine marine ad asse verticale
No full textIn questo lavoro si è sviluppato un modello di previsione delle prestazioni di una turbina marina ad asse verticale seguendo un approccio di tipo teorico-numerico. E` stato utilizzato, come strumento di analisi, un codice di calcolo che risolve le equazioni di Navier-Stokes non stazionarie per campi di moto bidimensionali incomprimibili, adottando un metodo ai volumi finiti. Si è dapprima verificata l’esatta impostazione del metodo utilizzato per confronto con varie configurazioni di flusso per le quali sono reperibili in letteratura dati numerici e sperimentali. Successivamente si è utilizzato il codice, opportunamente modificato, per predire le caratteristiche di funzionamento di un modello semplice di turbina ad asse verticale, del tipo Darrieus, costituito da un’unica pala avente un profilo alare di tipo simmetrico con corda rettilinea, appartenente alla serie NACA. L’analisi delle prestazioni di questo modello semplificato di turbina è stata effettuata sia mediante visualizzazioni del campo di moto che si instaura intorno alla pala, sia calcolando l’evoluzione temporale della potenza disponibile all’asse. E’ stata condotta un’analisi parametrica al variare del numero di Reynolds e del rapporto l tra la velocità periferica del rotore e la velocità della corrente indisturbata. Per ciascuna coppia di valori di questi due parametri si è analizzato l’andamento dei coefficienti aerodinamici e del coefficiente di coppia al variare della posizione assunta dalla pala durante la rotazione, ottenendo così l’andamento del coefficiente di potenza in funzione del parametro lambda. Sono stati infine eseguiti confronti con risultati sperimentali disponibili in letteratura mettendo in evidenza l’attendibilità del modello numerico
Leonardo Sileo, Teoria della scienza teologica. «Quaestio de scientia theologiae» di Odo Rigaldi e altri testi inediti (1230-1250) (coll. Studia Antoniana, 27). 1984
No full textElders L.-J. Leonardo Sileo, Teoria della scienza teologica. «Quaestio de scientia theologiae» di Odo Rigaldi e altri testi inediti (1230-1250) (coll. Studia Antoniana, 27). 1984. In: Revue théologique de Louvain, 18ᵉ année, fasc. 1, 1987. pp. 90-91
Dirty Dubbese: Dubbing as a Means of Taboo Language Transfer from English into Italian
No full textTaboos and taboo language are culture-specific, although overlapping areas do exist between different lingua-cultural systems (Pavesi and Malinverno 2000). When it comes to tele-cinematic products, the use of intensifying expletives seems to be increasingly frequent in English source texts whereas (self)censorship still prevails in Italian dubbese. Yet, taboo language is present in Italian dubbese as a footprint left behind by over-mechanical adaptations, offering word-for-word renderings of the source text and resulting in the so-called “doppiaggese”: this hybrid language is a pseudo-colloquial variety of Italian, characterized by routine translations, cliched phrases or sentences, repetition/redundancy and, more importantly, by calques from the source language (Rossi 1999; Alfieri et al. 2003; Sileo 2018).This essay analyzes taboo language transfers from English into Italian through dubbing, by providing examples from dubbed products and relying on corpora of contemporary spoken and written Italian as well as on dictionaries of the Italian language. Transfer phenomena are categorized based on both qualitative and quantitative criteria: as in Toury 1995, they are divided into either positive or negative transfers; on the basis of previous work by this author (Sileo 2018), an additional qualitative categorization is proposed, contrasting semantic and structural calques; moreover, a quantitative criterion takes into account the “size” of calques – ranging from lexical or word-level to sentence-level interferences. The aim is to determine whether and to what extent “dirty” dubbese has been influencing the taboo language production of Italian native speakers. The analysis revealed that the transfers are mainly of a negative type and cross word-unit borders, embracing more structured and more extended phrases; semantic calques seem to be scarcely present. This study, in spite of its limitations, might serve as a starting point for more extensive and in-depth analyses of presumable interferences from English into Italian.Taboos and taboo language are culture-specific, although overlapping areas do exist between different lingua-cultural systems (Pavesi and Malinverno 2000). When it comes to tele-cinematic products, the use of intensifying expletives seems to be increasingly frequent in English source texts whereas (self)censorship still prevails in Italian dubbese. Yet, taboo language is present in Italian dubbese as a footprint left behind by over-mechanical adaptations, offering word-for-word renderings of the source text and resulting in the so-called “doppiaggese”: this hybrid language is a pseudo-colloquial variety of Italian, characterized by routine translations, cliched phrases or sentences, repetition/redundancy and, more importantly, by calques from the source language (Rossi 1999; Alfieri et al. 2003; Sileo 2018).This essay analyzes taboo language transfers from English into Italian through dubbing, by providing examples from dubbed products and relying on corpora of contemporary spoken and written Italian as well as on dictionaries of the Italian language. Transfer phenomena are categorized based on both qualitative and quantitative criteria: as in Toury 1995, they are divided into either positive or negative transfers; on the basis of previous work by this author (Sileo 2018), an additional qualitative categorization is proposed, contrasting semantic and structural calques; moreover, a quantitative criterion takes into account the “size” of calques – ranging from lexical or word-level to sentence-level interferences. The aim is to determine whether and to what extent “dirty” dubbese has been influencing the taboo language production of Italian native speakers. The analysis revealed that the transfers are mainly of a negative type and cross word-unit borders, embracing more structured and more extended phrases; semantic calques seem to be scarcely present. This study, in spite of its limitations, might serve as a starting point for more extensive and in-depth analyses of presumable interferences from English into Italian
RANSEs Simulation of the Flow past a Marine Propeller under Design and Off-design Conditions
No full textIn the present work the results of a preliminary computational fluid dynamics (CFD) simulation of the flow past a marine propeller are presented. The principal aim of the study is to verify the ability of a CFD method, solving the Reynolds-Averaged Navier-Stokes Equations (RANSEs), to predict the performances of a marine propeller. The complexity in the mesh generation is one of the main obstacles for CFD. Following an hybrid mesh generation approach, prisms have been generated in the boundary layer, where viscous phenomena are dominant, and tetrahedra in the remaining regions. A parallel RANS solver has been used, employing a cell-centered, finite-volume method that allows the use of computational cells of arbitrary polyhedral shape. Boundary conditions were given to simulate the flow past a rotating propeller in open water conditions. The equations have been written in a moving reference frame fixed on the propeller blades. The steady-rotating reference frame source terms, i.e., the centrifugal and Coriolis force terms, therefore, are added to the RANS equations derived in the inertial frame. The k-w model has been employed for turbulence closure. Different values of advance ratios are considered, at design and off-design conditions. Computational results have been obtained for all the four-quadrant operational conditions: forward, backing, crashback and crashahead, considering also non-positif values for the advance ratio J. The thrust and torque coefficients, k_T and k_Q, have been selected as global quantities and compared with available experimental data. Pressure and velocity distributions and turbulent quantities were also used to analyze the computed flow field. The results show a good qualitative agreement with the experimental data. Important issues need to be addressed like an extensively improvement in the mesh generation techniques and in turbulence modeling
Effects of graded environmental hypercapnia on sea bass (Dicentrarchus labrax, L.) feed intake and acid-base balance
No full textEffects of graded environmental hypercapnia on sea bass (Dicentrarchus labrax, L.) feed intake and acid-base balance.
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