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Compaction conventionnelle et compaction grande vitesse : application aux produits multimatériaux et multifonctionsLe Guennec, Yann 25 May 2011 (has links) (PDF)
Parmi les procédés de mise en forme de pièces industrielles, la métallurgie des poudres autorise une haute cadence de production avec une faible perte de matière première. L'élaboration de composants multi-matériaux par compression et frittage permet de minimiser le nombre d'étapes de conception afin de combiner des propriétés complémentaires. L'objet de cette thèse est l'étude d'un procédé de compression innovant qui peut augmenter la cadence de production et diminuer les contraintes sur l'outillage : la CGV (compression grande vitesse), et de l'appliquer à la mise en forme de pièces multimatériaux. Une presse à grande vitesse a été développée au laboratoire afin d'étudier l'influence de la CGV sur deux couples de matériaux : un couple base Fe / base WC, associant dureté et ténacité, un couple Acier 1.4313 / Stellite 6 associant résistance mécanique et résistance à la corrosion. Des modélisations numériques des procédés de compression conventionnelle et CGV ont été réalisées dans le but de mieux analyser les phénomènes observés et de prévoir le comportement en compression de plusieurs poudres simultanément. Ce travail aboutit à des recommandations pour la mise en oeuvre de la compression de composants multi-matériaux et met au jour quelques caractéristiques de la CGV.
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Compaction conventionnelle et compaction grande vitesse : application aux produits multimatériaux et multifonctions / Conventional and high-velocity compaction : appliction on multimaterials and multifunctions productsLe Guennec, Yann 25 May 2011 (has links)
Parmi les procédés de mise en forme de pièces industrielles, la métallurgie des poudres autorise une haute cadence de production avec une faible perte de matière première. L'élaboration de composants multi-matériaux par compression et frittage permet de minimiser le nombre d'étapes de conception afin de combiner des propriétés complémentaires. L'objet de cette thèse est l'étude d'un procédé de compression innovant qui peut augmenter la cadence de production et diminuer les contraintes sur l'outillage : la CGV (compression grande vitesse), et de l'appliquer à la mise en forme de pièces multimatériaux. Une presse à grande vitesse a été développée au laboratoire afin d'étudier l'influence de la CGV sur deux couples de matériaux : un couple base Fe / base WC, associant dureté et ténacité, un couple Acier 1.4313 / Stellite 6 associant résistance mécanique et résistance à la corrosion. Des modélisations numériques des procédés de compression conventionnelle et CGV ont été réalisées dans le but de mieux analyser les phénomènes observés et de prévoir le comportement en compression de plusieurs poudres simultanément. Ce travail aboutit à des recommandations pour la mise en oeuvre de la compression de composants multi-matériaux et met au jour quelques caractéristiques de la CGV. / Among industrial shape processes, powder metallurgy has a high production rate associated to low waste of materials. Manufacturing of multi-material components by die pressing and sintering is useful to reduce the production cycle in order to combine complementary properties. The aim of this thesis is to study an innovative compaction process which can increase production rate and reduce stresses applied on tools: the HVC (High Velocity Compaction), and use it to shape multi-material components. A HVC device has been developed in our laboratory to investigate the influence of HVC on two couples of powders : A couple Fe / WC which combines toughness and hardness properties, a couple 1.4313 steel/Stellite 6 with mechanical resistance associated to corrosion resistance. Numerical simulations of conventional and HVC compaction process have been achieved to analyze phenomenon and predict the behavior of multi-materials components during compaction. This work ends in recommendations for the implementation of the compression of multimaterials components and brings to light some characteristics of the CGV.
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Relações intersetoriais entre atividades industriais e de serviços : um estudo da indústria de Tecnologia da Informação e Comunicação /Alves, Amanda Tamires January 2020 (has links)
Orientador: Rogério Gomes / Resumo: As tecnologias da informação e comunicação são reconhecidas por proporcionarem grandes transformações na economia. Elas foram fundamentais para o surgimento das cadeias globais de valor no século XX e continuam a influenciar a dinâmica e o funcionamento dessas cadeias, por meio de novos desenvolvimentos tecnológicos como big data, internet das coisas, nuvem, dentre outros. Por esta razão, esta pesquisa tem como objetivo analisar e quantificar os encadeamentos entre atividades industriais e de serviços para a indústria de TIC. Para isso, o estudo analisa as relações intersetoriais entre as duas atividades nas principais economias do mundo para os anos de 2000, 2007 e 2014, procurando identificar os principais elos entre elas. Essa análise permite compreender o papel que as duas atividades desempenham na economia e a relação entre ambas, bem como as mudanças estruturais no período. Como objetivos específicos, busca-se: (i) analisar as diferenças existentes entre as estruturas produtivas dos países; (ii) identificar a relevância das duas atividades nas economias nacionais e; (iii) compreender a participação do Brasil nesse contexto por meio da comparação internacional. A fim de atingir os objetivos estabelecidos é realizada análise descritiva pela ótica do valor adicionado, o cálculo dos índices de ligação para trás e para frente e do indicador de densidade. Esses métodos possibilitam a identificação de atividades chave em TIC e seus principais elos nas diferentes estruturas nac... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Information and communication technologies are recognized for providing major changes in the economy. They were fundamental for the emergence of global value chains in the 20th century and continue to influence the dynamics and functioning of these chains, through new technological developments such as big data, internet of things, cloud, among others. For this reason, this research aims to analyze and quantify the linkages between industrial and service activities for the ICT industry. To this end, the study analyzes the intersectoral relations between the two activities in the main economies of the world for the years 2000, 2007 and 2014, seeking to identify the main links between them. This analysis allows us to understand the role that the two activities play in the economy and the relationship between them, as well as the structural changes in the period. The specific objectives are to: (i) analyze the differences between the productive structures of the countries; (ii) identify the relevance of the two activities in national economies and; (iii) understand Brazil's participation in this context through international comparison. In order to achieve the established objectives, a descriptive analysis is performed from the perspective of added value, the calculation of backward and forward linkages indices and the density indicator. These methods make it possible to identify key ICT activities and their main links in different national structures. The results obtained show ... (Complete abstract click electronic access below) / Mestre
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Grande distribution, commerce traditionnel : quelle concurrence ? / Big grocery retailers, small retailers : which competition ?Pagot, Audrey 17 June 2011 (has links)
"Le Droit c'est l'instrument de réalisation d'un choix économique qui prolonge, lui-même, un choix politique fondamental" écrivait le Professeur Jean-Marc MOUSSERON. Poursuivant un choix politique de relance du pouvoir d'achat et / ou de lutte contre l'inflation, le droit économique a en effet cherché à protéger puis à encadrer la grande distribution. La prohibition du refus de vente, la prohibition de la majoration discriminatoire des prix ainsi que la prohibition des prix minimums imposés avaient ainsi pour objectif de protéger la concurrence de la grande distribution. La fragilisation du commerce indépendant traditionnel apparaît néanmoins comme un effet pervers de cette protection législative. Les pouvoir publics ont alors tenté de protéger cette forme de commerce traditionnel par des barrières à l'entrée légales anticoncurrentielles. En somme, soit les pouvoirs publics protègent la grande distribution au profit de la concurrence mais au détriment du commerce traditionnel, soit ils protègent le commerce traditionnel au détriment de la concurrence. Face à cette alternative il apparaît alors que seule une action législative tournée vers l'intérêt du consommateur -comme acteur de concurrence- permettra une régulation du marché de la distribution au profit tant de la concurrence de la grande distribution que du commerce traditionnel. / The French lecturer Jean-Marc MOUSSERON wrote that “law is the tool bringing economic choices into being, these economic choices themselves following fundamental political ones”. It is indeed by pursuing political choices such as the increase of the purchasing power or the reduction of consumer price that economic law protects and controls big retailers' action. By prohibiting the refusal to sell, the price discrimination practice and the minimum prices' resale practice, the French government tried indeed to protect the competition from grocery retailers. However as a consequence of this protection, small independent retailers lost their competitiveness. The French government tried hence to protect them by introducing anticompetitive legal barriers. To sum up, the government either protects the competition of grocery retailers to the detriment of traditional retailers or protects the small traditional retailers to the detriment of the competition. Bearing that alternative in mind, it seems that only a legislative action aiming to protect consumers will bring about a satisfyingly regulated retail market for the benefit of both the competition of grocery retailers and small retailers.
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Vojensko-politické aspekty sovětské invaze do ČSSR v srpnu 1968 / Military-political Aspects of Soviet Invasion Of CSSR in August 1968Čížek, Martin January 2013 (has links)
The aim of the dissertation is to explain the military-political reasons behind the long-term attempt of the Soviet Union to deploy its units on Czechoslovak territory, as well as the root cause of the military operation against Czechoslovakia which was carried out by the five member armies of the Warsaw Pact. One of the main reasons for this was the military and strategic situation in Central Europe in the 1960's, and also the issue of nuclear weapons and their carriers. A separate chapter is dedicated to Soviet attempts to deploy its units on Czechoslovak territory prior to Operation Danube. The final chapter deals with the reorganization of the CPA, the establishment of the CGV and the NATO reaction to the change in the strenght of armed forces present on the border of the two Blocs.
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