1,721,519 research outputs found
Analysis of passive temperature control systems using phase change materials for application to secondary batteries cooling
No full textTemperature control is one of the most significant factors to improve the performance and extend the cycle life of a battery. It is, therefore, important to design and implement an effective battery thermal management system (TMS). Phase change materials (PCMs) can be used as a cooling means for batteries. In the present paper, a preliminary analysis of the thermal behavior of PCMs used to cool down a heated metal surface was carried out. Tests have shown that pure PCMs are able to limit the temperature increase, but only for relatively low-heat fluxes. At higher values of the heat produced, the thermal conductivity of the PCM was increased by using solid foams characterized by higher thermal conductivity; it was, thus, possible to keep the surface temperature within safe limits for longer times. A computational fluid dynamics (CFD) model of the composite material (PCM+solid foam) was also developed, which allowed to predict the temperature trend within the system under different boundary conditions. However, the average thermal conductivity of the composite system that best fitted the experimental results was found to be much lower than that theoretically predicted by using common semiempirical correlations. © 2018 by ASME
Experimental and numerical analysis of a PCM for more uniform battery temperatures
No full textThis work presents an experimental and simulation analysis of a small-scale phase-change material (PCM) set-up containing A46 paffin wax . The main objective is to understand the solidification and melting process of the PCM with the aim of placing the same PCM ound an electric battery in order to guantee more stable and uniform temperatures during the chging or dischging of the battery. In first place, the experimental set-up including the PCM and the instrumentation is presented. The experimental device has been designed to measure the transient temperatures that occur in a volume of PCM when the lower face is subjected to a heat flow or a set temperature. A heater is located under a copper block and the PCM is in the upper pt (with a melting temperature of 46°C and a latent heat of 155 kJ / kg). An experimental campaign has been designed based on different heating rates, and the successive cooling and solidification is also measured. Subsequently, the main chacteristics of the model e explained. A CFD model has been developed in Fluent and the main pameters e given. Finally, the experimental results e comped with the simulations for different tests. The results indicate the complexity of the melting process, which involves heat and mass transfer on a vertical direction, whereas in the solidification process the vertical PCM temperatures can be better reproduced
Gentile, Gabetti e i fuoriusciti ebrei tedeschi. Il caso di Karl Löwith
No full textThis essay seeks to contribute, at least partially, to the reconstruction of the complex relationship with Italian culture in which Jew scholars, es-pecially German Jews who had migrated to Italy, engaged under fascism. Such reconstruction focuses in particular on the contexts associated to Giovanni Gentile in the 1930s and – through the analysis of the figure of Giuseppe Gabetti, then director of the Institute of Germanic Studies (which was presided by Gentile) – attempts to shed light on the thick net-work of interventions aimed at supporting, both culturally and financial-ly, scholars such as Paul O. Kristeller and Karl Löwith. While Kristeller’s case is rather renowned, Löwith’s still captures historians attention due to the papers, which are yet to be probed, gathered at the Institute of Germanic Studies in Villa Sciarra
Recensione a Andrea Mammone, Transnational Neofascism in France and Italy, Cambridge University Press, Cambridge – New York, 2015, in «Polis», vol. 2, p. 275-278.
No full textRecensione a Stefano Mangullo, Dal fascio allo scudo crociato. Cassa del mezzogiorno, politica e lotte sociali nell'agro pontino. (1944-1961), Milano, Franco Angeli, 2015, in «Archivio Storico Italiano», vol. 647, p. 202-203
No full textAir cooling of Li-ion batteries: An experimental analysis
No full textElectric vehicle industry has been rapidly developing internationally due to the renewed interest in low- or zero-emission vehicles. So far, Lithium-Ion batteries, is the technology that best fits the needs of electric vehicles, due to their large specific energy density and specific power, making these cells ideally suited for high rate-of-discharge applications such as during acceleration. In spite of this, there are safety concerns using Lithium-ion cells because of the use of high energy materials. Heat is a major battery killer and Lithium secondary cells need careful temperature control. Operating at high temperatures brings on a set of different problems which may result in the destruction of the cell: unless heat is removed faster than it is generated, a thermal runaway may occur. Tests with an air cooling system were carried out using an experimental loop specially designed: the tests were performed on a module consisting of four pouch cells, manufactured by EiG, connected in series. The module was discharged with a current of 80 A (4C discharge) and cooled with air at velocity ranging from 0 to 7 m/s. It was found that it is possible to completely discharge the batteries using air velocities higher than (or equal to) 4 m/s. Increasing the air velocity the temperature difference between the centre of the cell and the electrodes decreases. In spite of this, it was not possible to reach a uniform temperature distribution within a cell, and within the pack, using air as cooling fluid. © Copyright 2017, AIDIC Servizi S.r.l
Oltre Da Hegel a Nietzsche. Delio Cantimori legge Karl Löwith (1935-1965)
No full textIl saggio ricostruisce il rapporto tra Delio Cantimori e Karl Löwith dal primo incontro a Roma nel 1935 presso l’Istituto Italiano di Studi Germanici fino alla morte dello storico romagnolo. Scopo della riflessione è quello di mettere in luce il dialogo, spesso conflittuale, tra i due autori utilizzando principalmente i documenti d’archivio (come il carteggio conservato presso il Deutsches Literaturarchiv di Marbach) e alcuni scritti di Cantimori nei quali affiorano numerosi commenti alle opere e alle riflessioni di Löwith
. Recensione a Giuseppe Gabetti, Le letterature scandinave, a cura di Bruno Berni, Istituto Italiano di Studi Germanici, Roma, 2016, pp. 101. in «Nuova Rivista Storica», vol. Bollettino bibliografico: Schede.
No full textIl Petrarca Haus dalla Repubblica Weimar al Terzo Reich: genesi e sviluppo di un Istituto culturale italiano sulle rive del Reno.
No full textScopo del saggio è quello di ricostruire la storia del Petrarca Haus, Istituto culturale italiano inaugurato nel 1931 nella città di Colonia. Si è cercato, dunque, di chiarire la genesi del progetto, attraverso l’analisi dei fatti e dei personaggi coinvolti, e lo sviluppo dell’attività culturale dell’Istituto. Nonostante la carenza di documenti d’archivio, grazie ad alcuni fondi conservati presso l’archivio del Ministero degli Affari Esteri e dell’Istituto Italiano di Studi Germanici è stato possibile aggiungere un tassello alla ancora misconosciuta storia di questo Istituto
Cultura e politica in un'età di carenza. I rapporti culturali italo-tedeschi: le vicende dell'Istituto Italiano di Studi Germanici del Petrarca Haus (1928-1939)
No full textScopo della presente tesi è stato quello di ricostruire la storia e le vicende politiche-culturali dell'Istituto Italiano di Studi Germanici (Roma), fondato da Giovanni Gentile e Giuseppe Gabetti nel 1932, e del gemello tedesco Petrarca Haus, fondato a Colonia nel 1931 sempre grazie all'ausilio di Gentile e del borgomastro Konrad Adenauer. Attraversi i documenti d'archivio si è cercato di ricostruire sia la genesi del progetto di questi due istituti gemelli, sia l'attività culturale e propagandistica svolta dal 1931 al 1944
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