1,721,578 research outputs found
Some hydrodinamic aspects of supercritical flows on macrorough channels
No full textPubblicazione dell'Istituto di Idraulica e Costruzioni Idrauliche del Politecnico di Torin
The effect of inherent nonlinearities in coupled piezo-magneto-electric vibration energy harvester
Full text linkThis work deals with the experimental observation of inherent material nonlinearities occurring due to the magnetic plucking in a nonlinear piezoelectric vibration energy harvester. A piezoelectric cantilever is actuated via magnetic forces with a robotic arm at different constant velocities, in the range of 0.5 m/s - 2.5 m/s. The Fast Fourier Transforms of the voltage, in open circuit conditions, show that as the impulsiveness of the magnetic force
increases, the peak of the first bending mode of the beam shifts toward lower frequencies. Such
phenomenon should be taken into account for a reliable simulation and thus for the evaluation
of the optimal electrical condition of power extraction
A Review of Nonlinear Mechanisms for Frequency Up-Conversion in Energy Harvesting
Full text linkVibration-based energy harvesting has garnered considerable attention from researchers over the past two decades, using different transduction mechanisms. In this context, the utilization of piezoelectric materials has proven to be highly successful, due to their power density, across a broad range of voltages. A primary challenge in environmental vibration harvesting lies in the frequency mismatch between the devices, which typically exhibit optimal performance at hundreds or thousands of hertz due to their small size (centimeter or millimeter) and the environmental vibration. The latter has considerable energy density around tens of hertz. For this reason, over the last 15 years, the scientific community has concentrated on exploring techniques for band broadening or frequency up-conversion by intentionally introduced (or designed) nonlinearities. This review, following an introduction to the topic of vibration energy harvesting, provides a description of the primarily developed mechanisms, presenting a chronological development for each, from the initial works to the most recent advancements. Additionally, the review touches upon implementation efforts at the micro-electromechanical systems (MEMS) scale for each described technique. Finally, the incorporation of nonlinearities through electronic circuits to enhance performance is briefly discussed
"Freeze, Miami Vice!": sull'adattamento lingua-culturale in italiano della prima stagione delle serie TV
No full textRiconosciuta nelle ultime decadi la rilevanza degli studi riguardanti il linguaggio audiovisivo e la relativa traduzione in campo antropologico, socio-culturale e linguistico, maggiore interesse è stato dedicato a tale ambito di ricerca, mirando a comprendere come la sceneggiatura rappresenti il microcosmo dei personaggi inclusi nel prodotto audiovisivo e a investigare le strategie traduttive. Sebbene molteplici approcci siano stati efficaci per studiare sia il testo di partenza sia il testo di arrivo, l’adattamento dei riferimenti culturali si è dimostrato essere uno tra i temi costantemente analizzati, data la difficoltà di trasposizione nella cultura di arrivo. Partendo da tale presupposto, il contributo in oggetto presenta un’analisi comparativa (lingua originale – versione doppiata italiana) della prima stagione della serie TV americana “Miami Vice”, trasmessa in Italia tra il 1986 e il 1990. Il presente studio si concentra sulla traduzione dei riferimenti microculturali, investigando se e come tali specificità collegate alla contesto culturale di partenza siano state fedelmente riportate nella versione per il pubblico italiano. L’analisi qualitativa degli esempi inclusi nel contributo, suddivisi in sottocategorie, quali riferimenti culturali a celebrità/figure pubbliche/personaggi famosi americani, a oggetti personali, vestiti, accessori e cibi, e infine a festività tipicamente americane, dimostra che le specificità culturali incluse nel testo originale tendono a essere indebolite e/o neutralizzate nella versione tradotta. Tale scelta indubbiamente favorisce la fruizione del prodotto da parte del pubblico di arrivo ma tende a snaturare l’originale rappresentazione del contesto americano in cui la serie TV è ambientata
Critical review of new diecasting processes
No full textThe potential of light metals industry is very well documented by the continuous growth of the number of applications involving the use of these materials. Among the various manufacturing routes available, foundry processes have shown, in recent years, a significant degree of innovation and evolution. The more evident examples of this situation are certainly the semi-solid casting and squeeze casting processes. Both of them start from completely new metallurgical approaches (casting of a partially solidified metal, “forging” of a liquid metal), leading to final products having excellent mechanical and technological properties. This paper presents a review of the metallurgical basics of these two innovative casting processes, together with the description of their industrial and application potential
COMPARATIVE ANALYSIS OF THE STRUCTURE AND PROPERTIES PF Al/SiC(p) COMPOSITE MATERIALS AS A FUNCTION OF PM PROCESSING ROUTE
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