104,327 research outputs found
Effects of g-jitter on the critical marangoni number
No full textA half floating zone is fixed on a vibrational deck, which supports a periodical applied acceleration to simulate the effect of g-jitter. This paper deals with the effects of g-jitter on the fluid fields and the critical Marangoni number, which describes the transition from a forced oscillation of thermocapillary convection into an instability oscillatory convection in a liquid bridge of half floating zone with top rod heated. The responses of g-jitter field on the temperature profiles and flow pattern in the liquid bridge were obtained experimentally. The results indicated that the critical Marangoni number decreases with the increasing of g-jitter effect and is slightly smaller for higher frequency of g-jitter with fixed strength of applied gravity
Infrastrutture, servizi alle imprese e sviluppo economico locale
No full textQuesto lavoro si propone di analizzare il ruolo che il settore dei Servizi alle Imprese svolge in un sistema economico. Si tratta di una duplice funzione. Da un lato il settore dei Servizi alle Imprese costituisce un’industria la cui attività consiste nel produrre e vendere particolari servizi alle altre aziende. È un’industria che, nel quadro economico generale, ha un peso rilevante sia in termini di valore aggiunto che di numero di occupati. Da un secondo punto di vista, il settore dei Servizi alle Imprese si configura come un elemento infrastrutturale di tipo immateriale, in grado di influenzare la localizzazione delle attività produttive e di condizionare la competitività delle imprese e la loro stessa capacità di sopravvivenza e crescita
A. Traina - G. Bernardi Perini, Propedeutica al latino universitario. Quarta edizione completamente rifusa e aggiornata a cura di Claudio Marangoni
No full textTecnologia, internazionalizzazione e mercato: risultati di una ricerca sulle imprese industriali della Marca trevigiana
No full textLa ricerca traccia un quadro quanto più completo ed omogeneo della realtà economica locale della Marca trevigiana, mettendo in luce alcune interessanti relazioni tra l’evoluzione del contesto economico generale e i cambiamenti strutturali e organizzativi delle imprese
Analisi Input-Output
No full textIn questo capitolo del libro di testo si formalizza il modello dell'analisi intersettoriale, con l'uso dell'algebra delle matrici
Valutazioni economiche del day surgery: analisi costi-efficacia e analisi costi-benefici
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ICT e organizzazione della produzione
No full textIl contributo approfondisce tre aspetti: il rapporto tra investimenti in ICT ed organizzazione della produzione; il ricorso a particolari forme di esternalizzazione, come l’outsourcing e lo spin-off; lo sviluppo di nuove forme organizzative tra le imprese industriali della Marca trevigiana
Effect of Marangoni Convection Generated by Voids on Segregation During Low-G and 1-G Solidification
No full textSolidification experiments, especially microgravity solidification experiments are often hampered by the evolution of unwanted voids or bubbles in the melt. Although these voids and/or bubbles are highly undesirable, there are currently no effective means of preventing their formation or eliminating their adverse effects, particularly, during low-g experiments. Marangoni Convection caused by these voids can drastically change the transport processes in the melt and, therefore, introduce enormous difficulties in interpreting the results of the space investigations. Recent microgravity experiments by Matthiesen, Andrews, and Fripp are all good examples of how the presence of voids and bubbles affect the outcome of costly space experiments and significantly increase the level of difficulty in interpreting their results. In this work we examine mixing caused by Marangoni convection generated by voids and bubbles in the melt during both 1-g and low-g solidification experiments. The objective of the research is to perform a detailed and comprehensive combined numerical-experimental study of Marangoni convection caused by voids during the solidification process and to show how it can affect segregation and growth conditions by modifying the flow, temperature, and species concentration fields in the melt. While Marangoni convection generated by bubbles and voids in the melt can lead to rapid mixing that would negate the benefits of microgravity processing, it could be exploited in some terrestrial processing to ensure effective communication between a melt/solid interface and a gas phase stoichiometry control zone. Thus we hope that this study will not only aid us in interpreting the results of microgravity solidification experiments hampered by voids and bubbles but to guide us in devising possible means of minimizing the adverse effects of Marangoni convection in future space experiments or of exploiting its beneficial mixing features in ground-based solidification
Effect of preillumination on photomotile responses of the marine ciliate Fabrea salina
No full textFabrea salina is a marine ciliate that shows photomotile responses such as positive phototaxis and a step-down photophobic reaction. We found that preilluminated F. salina cells show a phototactic response significantly greater than that of dark-adapted cells when exposed to the same phototactic light stimulus. In particular, positive phototaxis is strongly enhanced by preillumination. This enhancement effect depends on the preillumination light irradiance, on the total preillumination dose, and on the duration of the dark interval between preillumination and the phototaxis measurement. Our results show that the determining factor is the tot preillumination dose given to the sample. The enhancement effect shows an asymptotic behavior over a certain range of energy values (10-200 W/m(2)). Further, the effect is transient; after 120 s in the dark, the cells lose any memory of the preillumination, independent of the preillumination energy received. These results are tentatively discussed in terms of light-driven membrane potential or membrane channel conductances
Coefficienti tecnici in termini fisici e in valore in un modello input-output: una generalizzazione
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