La thèse décrit la première synthèse totale de l'Eucophylline, le fragment sud de l'alcaloïde Leucophyllidine récemment isolé à partir de Leuconotisgriffithii et L. eugenifolius. La synthèse en 10 étapes comprend une nouvelle méthode d’accès au squelette azabicyclo[3.3.1]nonane par un processus de carbooximation radicalaire d'oléfines à trois composants. Au cours de ces études, nous avons également isolé des énamines présentant des stabilités inhabituelles résultant de leur conformation bicyclique tendue. La synthèse de la partie éburnane, le fragment nord de la Leucophyllidine, a été réalisée grâce à une nouvelle réaction radicalaire de carbo-cyanation à trois composants. Cette réaction radicalaire s'est révélée efficace pour installer le groupement fonctionnel nitrile sur des oléfines, et éventuellement former des centres quaternaires, notamment dans des structures complexes, puisqu'une bonne tolérance aux différents groupes fonctionnels a été observée. Le couplage biomimétique entre le squelette éburnane et l'Eucophylline a finalement été étudié en utilisant des modèles de structure similaire. Les résultats préliminaires de cette étude ont montré que l'absence d'effet gem-diméthyle dans le modèle éburnane empêche probablement la formation de l'imine cyclique,intermédiaire-clé dans le couplage désiré. / The thesis describes the first total synthesis of Eucophylline, the south fragment of the Leucophyllidine alkaloid recently isolated from Leuconotis griffithiiand L. eugenifolius. The 10-step synthesis encompasses a new straight forward method to access to the azabicyclo[3.3.1]nonane skeleton through a free-radical three-component olefinic carbo-oximation process. During these studies, we also isolated enamines exhibiting unusual stabilities resulting from their strained bicyclicconformation. The synthesis of the Eburnane part, the north fragment of Leucophyllidine, was developed relying on a new free-radical three-component Carbo-Cyanation reaction. This new reaction showed high tolerance toward different functional groups and provided an efficient mean to install the nitrile group in complex structures and to introduce quaternary centers. The biomimetic coupling between the Eburnane and Eucophylline fragments was finally studied using structurally similar models. Preliminary results of this model study showed that absence of a gemdimethyleffect in the Eburnane model probably prevents the formation of the cyclicimine, key intermediate for the desired coupling.

A presente dissertação trata de um estudo teórico-experimental sobre escoamento monofásico e bifásico no interior de tubos com fitas retorcidas. Esta técnica tem sido utilizada há várias décadas para a intensificação de troca de calor para escoamento monofásico e evaporação convectiva no interior de tubos. No entanto, com sua utilização, o aumento do coeficiente de troca de calor é acompanhado pelo incremento da perda de pressão. Portanto a compreensão dos fenômenos relacionados aos incrementos da perda de pressão e troca de calor são fundamentais para engenheiros projetistas. Neste estudo, inicialmente, é apresentada uma extensa revisão bibliográfica sobre padrões de escoamento, modelos para estimativa de fração de vazio e metodologias para previsão da perda de pressão em tubos com e sem fitas retorcidas para escoamentos bifásicos e monofásicos. Foram realizados experimentos em bancada experimental utilizando seção de testes com diâmetro interno de 15,9 mm e dois metros de comprimento com fitas apresentando razões de retorcimento de 3, 4, 9, 14 e , a última correspondente ao tubo sem inserto. Os experimentos foram executados para o refrigerante R134a, velocidades mássicas entre 75 e 250 kg/m²s, e títulos de vapor entre 5 e 95% no caso de escoamentos bifásicos. Resultados foram levantados para velocidades mássicas entre 100 e 450 kg/m²s para escoamentos monofásicos. Durante os ensaios foram levantados resultados de perda de pressão e identificados subjetivamente os respectivos padrões de escoamento. Como resultado final deste estudo é proposta uma correlação para previsão da perda de pressão durante o escoamento no interior de tubos com fitas retorcidas. / A theoretical and experimental study on single and two-phase flow inside tubes with twisted tapes inserts is presented. Twisted tape inserts have been used for decades as a technique of heat transfer enhancement. However, their heat transfer enhancement is accompanied by an increase of the pressure drop. Therefore, understanding the pressure drop and heat transfer mechanisms is fundamental for heat exchanger designers in order to optimize these devices when using twisted-tape inserts. Based on these aspects the present study concerns single and two-phase flows inside tubes with twisted tapes. Experiments were performed in an experimental apparatus for a 15.9 mm ID and twisted tape with twist ratios of 3, 4, 9, 14 and , the last one corresponding to a plain tube without tape. For two-phase flow, experiments were conducted for R134a, mass velocities from 75 to 250 kg/m²s and vapor qualities from 5 to 95%. In case of single-phase flow, experiments were performed for mass velocities from 100 to 450 kg/m²s. The experimental campaign was focused on pressure drop and flow pattern subjective identification. Additionally an extensive literature review on flow patterns, superficial void fraction, and methodologies for prediction of the pressure drop in plain tubes with and without twisted-tape inserts during single and two-phase flow is presented. As final result, a correlation for prediction of pressure drop during flow inside tubes with twisted tape inserts is proposed.

Ces travaux de recherche décrivent la synthèse d’architectures hélicoïdales et twistées à partir de briques moléculaires hétérocycliques. D’abord, la première partie est consacrée aux structures hélicéniques à savoir les carbohélicènes, oxahélicènes et fluorénones hélicoïdales.La deuxième partie du travail est dédiée à la préparation des architectures moléculaires twistées. Pour cela, nous avons mis au point une méthodologie simple et courte qui mène à des édifices hétérocycliques étendus à base du motif acridino-acridines et phénanthrolines à partir de la condensation entre des β-chlorovinylaldéhydes d’anilines diversement substituées. / The intertest of our research is the synthesis of helical and twisted architectures from heterocyclic molecular bricks. The first part is devoted to helicenic structures named carbohelicenes, oxahelicenes and helical fluorenones.The second part of the work describes the preparation of twisted molecular architectures. For this, we have developed a short and simple methodology that leads to twisted molecular architectures included acridines, acridino-acridines and phenanthrolines. This synthesis is accessible from the condensation between β-chlorovinylaldehydes and variously substituted anilines.

Orientador: Franco Giuseppe Dedini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-22T03:41:34Z (GMT). No. of bitstreams: 1 Duarte_AdrianaYumiSato_M.pdf: 12125505 bytes, checksum: 3905d87344e274e166ea8b7f129f87c3 (MD5) Previous issue date: 2013 / Resumo: A presente pesquisa tem como objetivo propor uma linguagem para a técnica artesanal de trançado manual, atividade praticada em diversas regiões do Brasil que utiliza materiais flexíveis para desenvolver produtos como cestos e esteiras, de modo a sistematizar a construção das armações e reafirmar a importância desta atividade para o país nos aspectos sociais, culturais e econômicos. Para tanto, o cenário desta pesquisa é baseado na análise da produção artesanal no Brasil, estudo do trançado manual e suas atividades análogas e a inserção das diretrizes de metodologia e ferramentas de projeto neste contexto. O conhecimento atrelado à prática do trançado manual é transmitido de forma oral e geracional, e em razão disto, está sendo perdido progressivamente. Por este motivo, como consequência da sistematização do trançado, o resgate deste conhecimento também é contemplado na pesquisa. Os resultados da pesquisa indicaram a relação entre o trançado manual e a tecelagem, atividade têxtil que transforma fios em tecidos, transferindo a nomenclatura, representação numérica e gráfica da tecelagem para o trançado manual. Assim, o que se pretende nesta pesquisa é sugerir uma linguagem para o trançado manual, ainda inexistente na área, que permita o desenvolvimento de um banco de dados e, futuramente, novas armações / Abstract: This research aims to propose a language for the artisanal braiding, a handicraft technique practiced in different regions of Brazil that uses flexible materials to develop products like baskets and mats, in order to systematize the construction and to reaffirm the importance of this activity in social, cultural and economic aspects. Therefore, the background of this research is based on the analysis of handicraft production in Brazil, the study of the braiding and its similar activities and the insertion of guidelines from methodology and design tools in this context. The knowledge linked to this practice is transmitted orally and between generations, and because of this, is being gradually lost. For this reason, as a consequence of the systematization of braiding, the rescue of this knowledge is also covered in this survey. The results indicated the relationship between artisanal braiding and weaving, a textile activity that transforms yarn into fabric, transferring the numerical and graphical representation for weaving to braiding. So, what is intended in this research is to suggest a language for artisanal braiding, which is lacking in the area, in order to allow the development of a database and, in future, new patterns / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestra em Engenharia Mecânica

Cette thèse a pour objectif de montrer que les paquets de représentations cohomologiques d’un groupe réductif classique quasi déployé, défini sur R, construits par J. Arthur coïncident avec les paquets précédemments définis de manière plus élémentaire et plus explicite par Adams et Johnson... / The aim of this thesis is to prove that the packets of cohomological representation of quasi-split classical groups, defined over R, by Arthur coincide with the packets defined previously in a more elementary way by Adams and Johnson...

Working over an arbitrary field F of characteristic not 2, we consider linear algebraic groups over F. We view these as functors, represented by finitely generated F-Hopf algebras, from the category of commutative, associative, F-algebras Alg_F, to the category of groups. Classical examples of these groups, such as the special linear group SL_n are split, however there are also linear algebraic groups arising from central simple F-algebras which are non-split. For example, associated to a non-split central simple F-algebra A of degree n is a non-split special linear group SL(A). It is well known that central simple algebras are twisted forms of matrix algebras. This means that over the separable closure of F, denoted F_sep, we have A⊗_F F_sep ∼= M_n(F_sep) and that there is a twisted Gal(F_sep/F)-action on M_n(F_sep) whose fixed points are A. We show that a similar method of twisted Galois descent can be used to obtain all non-split semisimple linear algebraic groups associated to central simple algebras as fixed points within their split counterparts. In particular, these techniques can be used to construct the spin and half-spin groups Spin(A, τ ) and HSpin(A, τ ) associated to a central simple F-algebra of degree 4n with orthogonal involution. Furthermore, we develop a theory of twisted Galois descent for Hopf algebras and show how the fixed points obtained this way are the representing Hopf algebras of our non-split groups. Returning to the view of group schemes as functors, we discuss how the group schemes we consider are sheaves on the étale site of Alg_F whose stalks are Chevalley groups over local, strictly Henselian F-algebras. This allows us to use the generators and relations presentation of Chevalley groups to explicitly describe group scheme morphisms. After showing how the Kronecker tensor product of matrices induces maps between simply connected groups, we give an explicit description of these maps in terms of Chevalley generators. This allows us to compute the kernel of these new maps composed with standard isogenies and thereby construct new tensor product maps between non-simply connected split groups. These new maps are Gal(F_sep/F)-morphisms and so we apply our techniques of twisted Galois descent to also obtain new tensor product morphisms between non-split groups schemes. Finally, we use one of our new split tensor product maps to compute the degree three cohomological invariants of HSpin_4n for all n.

The master thesis deals design of condensing steam turbine in the heat scheme. The content of the thesis is divided into five parts. The first part describes the design and preliminary calculation of turbine heat balance in which the turbine is to be operated. The second part is dedicated to the preliminary design and detail calculation of control stage. The control stage is solved witch impulse blading. Next part describes the design of reaction blading type which is divided into 5 flow channels. This design is followed by the design of the last stage twisted blade geometry. Comparison of the efficiency results stage is made to the designated geometry of the last twisted blades and the preliminary design of the turbine stage, where the prismatic blade type was considered. Strength calculation is performed for the design of the last rotor blade and evaluated by Goodman and Langer criteria. The last part outlines evaluation of turbine design and technical background documentation of last stage blades is processed.

The aim of this diploma thesis is to get acquainted with modern technological elements currently used in shell-and-tube heat exchanger in the shell-side and tube-side, thermal-hydraulic calculation of selected elements and comparison of thermal-hydraulic properties with classically used competing technological elements. The work deals mainly with EM baffle in the tube-side and tube inserts like the twisted tape type (and its modifications) and coiled wire in the tube-side. The theoretical part is focused on acquaintance with classical technological elements in shell-and-tube heat exchanger and with basic thermal-hydraulic calculations, practical part then on acquaintance with modern elements and thermal-hydraulic calculation of selected elements. These calculations are then compared with the results of the thermo-hydraulic calculation of similar elements.

This Master’s thesis deals with a pre-calculation of a steam condensation turbine on a blading mid diameter. The governing stage is solved as a A-turbine wheel, impulse blading. Multistage blading is solved as a reacion stage by ca/u method. Further, detailed calculation of last stage with a twisted blade is made. Thesis contains comparision of obtained results with a results provided by contracting company. Final part of thesis deals with a design of sectional shape of a turbine blade.

Les supraconducteurs à hautes températures sont considérablement utilisés dans des applications telles que des machines électriques. La conception de telles machines requiert une évaluation précise des pertes AC générées par leurs bobinages de câbles supraconducteurs multifilamentaires torsadés. Ainsi, des outils numériques robustes et précis sont indispensables afin de modéliser rapidement en 3D le comportement de tels câbles. Dans ce manuscrit, deux approches numériques dont une approche de type galerkin discontinue furent développées afin de simplifier considérablement la modélisation 3D de ce type de câbles. Elles furent appliquées à la formulation en H couplée aux effets thermiques. La modélisation de cas simples a permis de valider ces approches en les comparant à celle des éléments finis implémentée sur Comsol. Puis, une transformation géométrique fut proposée afin de modéliser de façon équivalente en 3D, quelque soit la configuration en champ magnétique, des câbles à filaments supraconducteurs droits à la place de filaments torsadés. De cette transformation, un modèle d'ordre réduit fut développé et validé afin de simplifier considérablement la modélisation 3D de ce type de câbles. À partir de ce modèle réduit, l'influence du champ elliptique sur les pertes par aimantation d'un échantillon de 100 câbles de 54 filaments de MgB ₂ torsadés fut modélisé en moins d'une journée. Par ailleurs, des premières études empiriques montrant la faisabilité d'une homogénéisation furent brièvement présentées et validées pour des câbles ayant une seule couche de filament. / High temperature superconductors are increasingly being used for several applications such as electrical machines. Thus the design of suchdevices ultimately requires an accurate evaluation of AC losses generated by superconducting coils sometimes made of twisted multifilamentary wires.The development of robust numerical tools geared towards the 3 D modeling of such wires is therefore needed. In this manuscript, the main objective isto develop numerical approaches allowing considerable simplifications of the modelling of twisted multi-filamentary superconducting wires in 3 D. First, two numerical approaches such as the discontinuous galerkin method applied on the thermally coupled H -formulation were developed. They were compared and validated on simple cases using the finite element method implemented in Com-sol. Then, a well-defined mapping was proposed to simply model in 3 D, for any magnetic field configuration, straight multifilamentary wires instead oftwisted ones. An application of this mapping allowed the development of a model-order reduction approach which simplify considerably the mod-elling of twisted wires in 3 D. Thus, the elliptical magnetic fields impact on magnetization losses was accurately modeled in less than a day with the reduced approach applied on 100 MgB ₂ wires with 54 twisted filaments. As a research perspective on the reduced model advanced applications, an homogenization, empirically defined, was briefly presented for wires with single layer only.