990 resultados para stabilità argine, fem, fiume Po, modellazione


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Celem artykułu jest ukazanie uwarunkowań reorientacji polityki Unii wobec regionu Afryki Północnej po roku 2011, w związku z jej zaangażowaniem podczas ‘arabskiej wiosny’, a także analiza zakresu nowego podejścia w odniesieniu do praktycznych możliwości wdrażania unijnych instrumentów polityk. Powyższe rozważania pozwolą na przedstawienie wniosków dotyczących dalszego zaangażowania Unii Europejskiej w regionie Afryki Północnej i budowy nowych ram podejścia strategicznego UE w tym regionie, zarówno na płaszczyźnie ustalania interesów na arenie brukselskiej, jak i przedstawienia wypracowanego stanowiska i uruchomienia działań na arenie międzynarodowej.

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We present a dynamic distributed load balancing algorithm for parallel, adaptive Finite Element simulations in which we use preconditioned Conjugate Gradient solvers based on domain-decomposition. The load balancing is designed to maintain good partition aspect ratio and we show that cut size is not always the appropriate measure in load balancing. Furthermore, we attempt to answer the question why the aspect ratio of partitions plays an important role for certain solvers. We define and rate different kinds of aspect ratio and present a new center-based partitioning method of calculating the initial distribution which implicitly optimizes this measure. During the adaptive simulation, the load balancer calculates a balancing flow using different versions of the diffusion algorithm and a variant of breadth first search. Elements to be migrated are chosen according to a cost function aiming at the optimization of subdomain shapes. Experimental results for Bramble's preconditioner and comparisons to state-of-the-art load balancers show the benefits of the construction.

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Pío Collivadino was a highly recognized painter in life, occupying the most important charges in the artistic field and receiving awards in his country and abroad, which turned him into an inescapable reference of young Argentinean artists who earned recognition throughout the twentieth century. Why, then, with the time, his work began to fall to the wayside? In response to this question, the present article, based on the analysis of the work of that artist, proposes to problematize the notion of subjectivity, both in its individual dimension and its national character, underlining the role that the figure of the artist meets for its formation. Developing the concepts of light-color and body-mass, from Collivadino painting, this article will attempt to explain the relation between the emergence of an Argentinean subjectivity, at the beginning of 20th century, and the art, not only at the level of the issues addressed, but, especially, taking into consideration its formal characteristics.

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In this study, the feasibility of using H3PO4-activated lignin for hexavalent chromium adsorption has been investigated. The composite of activated lignin was characterized using FTIR, XRD and SEM with EDAX analysis. It was observed that the pH had a strong effect on the adsorption capacity; adsorption of Cr(VI) was more favorable at acidic pH with maximum uptake at pH 2. The adsorption equilibrium data were best represented by Koble-Corrigan isotherm. The monolayer sorption capacity obtained from the Langmuir model was found to be 77.85 mg/g. Adsorption showed pseudo-second order rate kinetics and the process involving the rate-controlling step is complex as it involves both film and intraparticle diffusion processes. The NaOH desorbing agent was able to release approximately 84% of metal ions. Thermodynamic parameters showed that the sorption process is exothermic and non-spontaneous. The overall Cr(VI) retention on the activated lignin surface perhaps includes both the physical adsorption of Cr(VI) and the consequent reduction of Cr(VI) to Cr(III). (C) 2011 Elsevier B.V. All rights reserved.

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As an emerging hole-machining methodology, helical milling process has become increasingly popular in aeromaterials manufacturing research, especially in areas of aircraft structural parts, dies, and molds manufacturing. Helical milling process is highly demanding due to its complex tool geometry and the progressive material failure on the workpiece. This paper outlines the development of a 3D finite element model for helical milling hole of titanium alloy Ti-6Al-4V using commercial FE code ABAQUS/Explicit. The proposed model simulates the helical milling hole process by taking into account the damage initiation and evolution in the workpiece material. A contact model at the interface between end-mill bit and workpiece has been established and the process parameters specified. Furthermore, a simulation procedure is proposed to simulate different cutting processes with the same failure parameters. With this finite element model, a series of FEAs for machined titanium alloy have been carried out and results compared with laboratory experimental data. The effects of machining parameters on helical milling have been elucidated, and the capability and advantage of FE simulation on helical milling process have been well presented.

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A erosão localizada nas fundações de pilares e encontros é uma das causas de rotura em pontes, podendo conduzir a perdas consideráveis de vidas humanas e bens materiais. Para avaliar este tipo de fenómenos, em estruturas existentes ou a construir e ainda estimar os danos provocados pela alteração da secção transversal do leito, é proposta uma metodologia para o estudo hidráulico e sedimentológico. Este estudo foca os níveis atingidos pela cheia, o risco de a obra ser galgada durante o seu tempo de vida útil e a erosão a que esta está sujeita junto dos pilares e encontros.

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Tendo Macau por contexto, quinze anos após a transferência da sua administração para a República Popular da China e cinco séculos de presença portuguesa, o estudo efetua uma abordagem às representações e estereótipos sociais dos portugueses, a partir de um inquérito a cento e setenta e cinco mulheres chinesas desta Região Administrativa Especial (RAEM). Tendo como marcos conceptuais a Teoria das Representações Sociais, de Moscovici, e a Teoria da Identidade Social, de Tajfel, o estudo procura explicitar os saberes sociais construídos por esse grupo de referência, determinantes na forma como se processa a comunicação e a interação grupal com portugueses e âncora para a construção de estereótipos com os quais esses processos são simplificados, mas também enviesados. Antevendo-se, num horizonte não muito longínquo, decisões quanto à manutenção do princípio “um país, dois sistemas”, que viabiliza a preservação de marcas portuguesas (como a língua) e uma abertura especial à presença de portugueses em Macau, a compreensão das imagens e metáforas sobre esta comunidade constitui estratégia relevante para a perspetivação, no presente como no futuro, das relações intergrupais que a envolvem. O estudo conclui que as representações sobre os portugueses são, no essencial, de pendor positivo e exibem uma abertura à proximidade social e à participação desta comunidade nas dinâmicas sociais da RAEM. Mas assinala também áreas de potencial maior conflitualidade na defesa, pelo endogrupo, de áreas vitais de afirmação dessa nova ordem social pós- transferência.