1,355,779 research outputs found
Andrea Passoni, Economia delle piattaforme e architettura digitale delle scelte
No full textAndrea Passoni ha depositato sull’archivio Marini Economia delle piattaforme e architettura digitale delle scelte. Appunti sull’alternativa cooperativa, su un tema di grande attualità, la cosiddetta sharing economy. A dispetto del nome accattivante, molte delle sue esperienze più note ricadono nel..
Omelie, meditazioni e interventi vari
No full textL'importanza del testo biblico nella produzione omiletica ed esegetica di scritti inediti di E. Galbiat
Target normal sheath acceleration analytical modeling, comparative study and developments
No full textUltra-intense laser interaction with solid targets appears to be an extremely promising technique to accelerate ions up to several MeV, producing beams that exhibit interesting properties for many foreseen applications. Nowadays, most of all the published experimental results can be theoretically explained in the framework of the target normal sheath acceleration (TNSA) mechanism proposed by Wilks [Phys. Plasmas 8(2), 542 (2001)10.1063/1.1333697]. As an alternative to numerical simulation various analytical or semi-analytical TNSA models have been published in the latest years, each of them trying to provide predictions for some of the ion beam features, given the initial laser and target parameters. However, the problem of developing a reliable model for the TNSA process is still open, which is why the purpose of this work is to enlighten the present situation of TNSA modeling and experimental results, by means of a quantitative comparison between measurements and theoretical predictions of the maximum ion energy. Moreover, in the light of such an analysis, some indications for the future development of the model proposed by Passoni and Lontano [Phys. Plasmas 13(4), 042102 (2006)10.1063/1.2184067] are then presented. © 2012 American Institute of Physics
Target normal sheath acceleration analytical modeling, comparative study and developments
No full textUltra-intense laser interaction with solid targets appears to be an extremely promising technique to accelerate ions up to several MeV, producing beams that exhibit interesting properties for many foreseen applications. Nowadays, most of all the published experimental results can be theoretically
explained in the framework of the target normal sheath acceleration (TNSA) mechanism proposed by Wilks et al. [Phys. Plasmas 8(2), 542 (2001)]. As an alternative to numerical simulation various analytical or semi-analytical TNSA models have been published in the latest years, each of them trying to provide predictions for some of the ion beam features, given the initial laser and target parameters. However, the problem of developing a reliable model for the TNSA process is still open, which is why the purpose of this work is to enlighten the present situation of TNSA modeling and experimental results, by means of a quantitative comparison between measurements and theoretical predictions of the maximum ion energy. Moreover, in the light of such an analysis, some indications
for the future development of the model proposed by Passoni and Lontano [Phys. Plasmas 13(4), 042102 (2006)] are then presented
On the role of non-equilibrium, relativistic hot electron population in Target Normal Sheath Acceleration
No full text: Las Pasantías en el sistema universitario. Estudio de caso: la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata
No full textLa Extensión Universitaria es una de las funciones específicas de las Universidades Nacionales. Considerando la importancia que tienen las pasantías como generadores de indicadores útiles para la actualización de la actividad curricular es imprescindible generar un modelo de gestión específico que potencie sus beneficios y facilite su ejecución. La implementación física del nuevo modelo de gestión requiere la utilización de un Sistema de Información adecuado, flexible y, sobre todo, ágil, capaz de recoger los datos de las múltiples fuentes, y presentarlas de forma adecuada e inteligible. La etapa de implementación se centrará en el uso de una Intranet local desde donde se accederá a través de interfases de navegación homogéneas y orientadas al usuario a los procesos de generación de conocimiento de interés para la visualización de resultados. El Sistema de Información para Pasantías tiene como propósito brindar información tanto para el proceso de selección de postulantes como para la toma de decisiones sobre las características de las demandas de la inserción laboral del alumno. A partir de establecer relaciones causa-efecto se proponen un conjunto de indicadores desarrollados a partir de las diferentes perspectivas: procesos, aprendizaje, cliente y financiera. El diseño del Sistema de Información de Pasantías permite acceder a la información necesaria para calcular estos indicadores, como así también mostrar a través de interfaces de visualización resultados obtenidos versus resultados esperados como una manera de observar la brecha que separa la situación real con la ideal. Es importante resaltar la relevancia de la información cualitativa obtenida a través de este trabajo sobre el Sistema de Pasantías de la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata, acerca de la satisfacción de la entidad adherente y del pasante, del perfil solicitado como del perfil ofrecido. Esta nueva mirada centrada en los datos cualitativos, permitirá la contrastación efectiva de los objetivos esperados versus los planificados, desde las distintas dimensiones abordadas en este proyecto. El diseño del sistema de pasantías, pequeño en relación a la magnitud del que debe pensarse para la organización en su totalidad, intenta mostrar que es factible la utilización de este tipo de modelos en el contexto de la gestión Universitaria
Slow light with interleaved p-n junction to enhance performance of integrated Mach-Zehnder silicon modulators
No full textSlow light is a very important concept in nanophotonics, especially in the context of photonic crystals. In this work, we apply our previous design of band-edge slow light in silicon waveguide gratings [M. Passoni et al, Opt. Express 26, 8470 (2018)] to Mach-Zehnder modulators based on the plasma dispersion effect. The key idea is to employ an interleaved p-n junction with the same periodicity as the grating, in order to achieve optimal matching between the electromagnetic field profile and the depletion regions of the p-n junction. The resulting modulation efficiency is strongly improved as compared to common modulators based on normal rib waveguides, even in a bandwidth of 20–30 nm near the band edge, while the total insertion loss due to free carriers is not increased. The present concept is promising in view of realizing slow-light modulators for silicon photonics with reduced energy dissipation
Carichi effluenti dagli scaricatori di piena di fognature unitarie. Inquadramento teorico e valutazioni numeriche di lungo periodo.
No full textLa nota descrive un inquadramento teorico ed un'analisi numerica volti alla determinazione delle masse di inquinante sversate nei recapiti superficiali da scaricatori di piena (con e senza annesse vasche di pioggia) inseriti in reti di drenaggio di tipo unitario. L'inquadramento teorico, fondato su alcune ipotesi semplificative che studi sperimentali recenti hanno pero' mostrato essere accettabili se la base temporale di riferimento e' sufficientemente estesa, ha consentito di giungere ad una soluzione generale del problema, per un prefissato regime pluviometrico. Oltre al volume idrico complessivamente sversato verso il recapito, risulta fondamentale la conoscenza di un raggruppamento adimensionale, rappresentativo del rapporto di mescolamento medio efficace tra le acque reflue e quelle meteoriche. L'andamento di tali grandezze e' stato poi determinato, per via numerica e su base temporale annua, per il regime pluviometrico milanese. Si sono analizzati sia scaricatori "semplici" cioe' privi di invasi, che scaricatori abbinati a capacita' di invaso di tipo ON-LINE ed OFF-LINE.
Gli abachi cosi' ottenuti possono essere utilizzati per stimare l'apporto di inquinanti persistenti in corpi idrici a debole ricambio e per valutare l'efficacia dei volumi di invaso nella riduzione dell'impatto
Non-equilibrium effects in a relativistic plasma sheath model
No full textPlasma sheaths characterized by electrons with relativistic energies and far from thermodynamic equilibrium are governed by a rich and largely unexplored physics. A reliable kinetic description of relativistic non-equilibrium plasma sheaths - besides its interest from a fundamental point of view - is crucial to many application, from controlled nuclear fusion to laser-driven particle acceleration. Sheath models proposed in the literature adopt either relativistic equilibrium distribution functions or non-relativistic non-equilibrium distribution functions, making it impossible to properly capture the physics involved when both relativistic and non-equilibrium effects are important. Here we tackle this issue by solving the electrostatic Vlasov-Poisson equations with a new class of fully-relativistic distribution functions that can describe non-equilibrium features via a real scalar parameter. After having discussed the general properties of the distribution functions and the resulting plasma sheath model, we establish an approach to investigate the effect of non-equilibrium solely. Then, we apply our approach to describe laser-plasma ion acceleration in the target normal sheath acceleration scheme. Results show how different degrees of non-equilibrium lead to the formation of sheaths with significantly different features, thereby having a relevant impact on the ion acceleration process. We believe that this approach can offer a deeper understanding of relativistic plasma sheaths, opening new perspectives in view of their applications
Widespread morphea. A case treated with factor XIII
No full textAn 11-year-old girl with widespread and progressive localized cutaneous scleroderma was treated with factor XIII. The treatment was responsible for moderate improvement of the cutaneous lesions. This treatment has been until now used in systemic sclerosis and in generalized cutaneous scleroderma. However, given the lack of side effects, the treatment can be used, according to the authors, even in cases of localized cutaneous scleroderma affecting exposed areas or rather extensive
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