Zugl.: Stuttgart, Univ., Diss., 2005.

Made available in DSpace on 2014-06-11T19:26:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-22Bitstream added on 2014-06-13T20:35:10Z : No. of bitstreams: 1 ferreira_fe_me_sjrp.pdf: 904891 bytes, checksum: 189144772384df69733ce1617b84cb5d (MD5) / De acordo com as atuais diretrizes pertinentes ao ensino de matemática (Parâmetros Curriculares Nacionais : Matemática e Proposta Curricular do Estado de São Paulo: Matemática), este trabalho baseia-se na Teoria de Van Hiele, visando a aprendizagem de conceitos geométricos, em particular a aprendizagem de poliedros regulares, através da confecção de dobraduras (origami). Iniciando com uma abordagem histórica sobre poliedro, apresenta orientações para o uso de origami em sala de aula, delineia as principais características da Teoria de Van Hiele, além de retomar os principais conceitos matemáticos associados aos poliedros. Utilizando este arcabouço é proposta uma sequência de atividades de sondagem e aplicação de conceitos geométricos respeitando as fases de aprendizagem de Van Hiele, visando a conclusão por parte do aluno, da existência de apenas cinco poliedros regulares. Após a execução das atividades propostas, as demonstrações dos teoremas relacionados aos poliedros apresentados neste trabalho servirão para a sistematização das conclusões feitas pelos alunos, sempre respeitando o nível de Van Hiele em que se encontrem. Apresenta, ainda, atividades de exploração das características dos poliedros através do Teorema de Euler para poliedros convexos / According to the current guidelines relevant to teaching mathematics (National Curriculum: Mathematics, and Curricular Proposal of the State of São Paulo: Mathematics) this work is based on Van Hiele, and aimed at learning of geometric concepts, particularly learning regular polyhedra, by paperfolding (origami). Starting with a historical approach of polyhedron, this work presents guidelines for the use of origami in the classroom, outlines the main features of the Van Hiele theory, and resume the main mathematical concepts associated with polyhedra. Using this framework, a sequence of activities is proposed and the applying of geometric concepts respecting the learning phases of Van Hiele, which aims deduction by the student, of the existence of only five regular polyhedra. After execution of the proposed activities, the proof of theorems related to polyhedra presented in this paper will serve to systematize the conclusions made by the students, always respecting the level of Van Hiele who are. It presents further exploration of the characteristics of polyhedra by Euler's theorem for convex polyhedra

Submitted by Marcos Samuel (msamjunior@gmail.com) on 2017-05-31T15:01:53Z No. of bitstreams: 1 Dissertação - Jorge Alécio.pdf: 2573603 bytes, checksum: 85b77d6e458f82beec7bc103ad58be91 (MD5) / Approved for entry into archive by Vanessa Reis (vanessa.jamile@ufba.br) on 2017-06-06T14:28:58Z (GMT) No. of bitstreams: 1 Dissertação - Jorge Alécio.pdf: 2573603 bytes, checksum: 85b77d6e458f82beec7bc103ad58be91 (MD5) / Made available in DSpace on 2017-06-06T14:28:58Z (GMT). No. of bitstreams: 1 Dissertação - Jorge Alécio.pdf: 2573603 bytes, checksum: 85b77d6e458f82beec7bc103ad58be91 (MD5) / Nesta dissertação será feita uma análise da situação atual do ensino da Geometria nos cursos do Ensino Médio através da apresentação do Teorema de Euler para Poliedros Convexos e da análise da sua utilização em salas de aula. Será feita uma re flexão sobre o desenvolvimento do raciocínio dedutivo nesse nível de ensino e sobre a abordagem que se dá a formação do cidadão quanto a algumas competências importantes para a capacidade de análise crítica da realidade. Uma abordagem histórica investigará a trajetória das didáticas utilizadas no ensino dessa ciência. Por m serão levantadas propostas para o ensino de Geometria e para o desenvolvimento do raciocínio dedutivo através de demonstrações geométricas.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-08-30T17:24:15Z No. of bitstreams: 1 texto completo.pdf: 4232344 bytes, checksum: 570158c74aae3b6b7b1e909cc8bc8bce (MD5) / Made available in DSpace on 2016-08-30T17:24:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4232344 bytes, checksum: 570158c74aae3b6b7b1e909cc8bc8bce (MD5) Previous issue date: 2015-08-28 / Um tema de estudo do ensino médio ́e a relação entre os números de vértices, arestas e faces, para poliedros convexos regulares, conhecida como Teorema de Euler. No caso geral esta relação ́e conhecida como característica de Euler. Neste trabalho apresentaremos exemplos de poliedros não convexos que satisfazem o Teorema de Euler e algumas formas de calcular a característica de Euler para poliedros no caso em geral, com o objetivo de fornecer um material mais acessível para professores que trabalham com este tema. / One topic of study in the high school is the relation between the number of vertices, the number of edges and the number of faces, for regular convex polyedra, known as Euler’s theorem. In the general case this relationsship is known as Euler characteristic. In this paper we present examples of non-convex polyhedrons which satisfies the Euler’s Theorem. We present some ways to computer the Euler characteristic to polyhedrons in the general case.

Dans cette thèse, on étudie la contrôlabilité et la stabilisation de certaines équations aux dérivées partielles . On s'intéresse d'abord au problème du contrôle de l'équation d'Euler 3D incompressible par une force extérieure de dimension finie. Nous montrons que pour un choix approprié de l'espace de contrôle, la vitesse et la pression du fluide sont exactement contrôlables en projections. De plus, la vitesse est approximativement contrôlable. Nous montrons aussi que le système en question n'est pas exactement contrôlable par une force extérieure de dimension finie.On étudie aussi la contrôlabilité de l'équation d'Euler 3D compressible. Le contrôle est une force extérieure de dimension finie agissant uniquement sur l'équation de la vitesse. Nous montrons que la vitesse et la densité du fluide sont simultanément contrôlables. En particulier, le système est approximativement contrôlable et exactement contrôlable en projections. Dans la dernière partie, on étudie la stabilisation de l'équation d'Euler dans un cylindre infini.Nous montrons que pour toute solution stationnaire (c,0) du système d'Euler il existe un contrôle supporté dans une partie de la frontière du cylindre qui stabilise le système à (c,0). / In this thesis, we study the controllability and stabilization of certain partial differential equations.We consider first the problem of control of the 3D incompressible Euler equationby an external force of finite dimension. We show that for an appropriate choice of control space, the velocity and the pressure of the fluid are exactly controllable in projections.Moreover, the velocity is approximately controllable. We also show that the system in question is not exactly controllable by a finite-dimensional external force.We also study the controllability of the 3D compressible Euler equation. The control is a finite-dimensional external force acting only on the velocity equation. We show that the velocity and density of the fluid are simultaneously controllable. In particular, the system is approximately controllable and exactly controllable in projections.The last section of the thesis is devoted to the study of a stabilization problem for the 2D incompressible Euler system in an infinite strip with boundary controls. We show that for any stationary solution (c,0) of the Euler system there is a control which is supported in a given bounded part of the boundary of the strip and stabilizes the system to (c,0).

De nos jours, la combustion représente encore un 90% de la production totale d'énergie au monde. La plupart des brûleurs de type industriel utilisent comme carburant des hydrocarbures en forme liquide. Cependant, un grand nombre d'études ont été dédiés aux flammes gazeuses et l'impact du spray liquide est encore loin d'être totalement compris. Le but de cet étude est l'amélioration de la modélisation des deux phénomènes principaux qui ont lieu entre l'atomisation du spray et la combustion, i.e. la dispersion des gouttes par la turbulence gazeuse et le procès d'évaporation dans le contexte de la Simulation Aux Grandes Echelles (SGE) des configurations complexes. Premièrement, l'approche Euler-Euler mésoscopique (Février et al. (2005)), basée sur une moyenne d'ensemble conditionnée et implémentée dans AVBP est amélioré. Le modèle de fermeture (Simonin et al. (2001); Kaufmann (2004)) pour les moments de deuxième ordre qui apparait dans les équations de transport résolues échoue quand appliqué à des configurations cisaillées (Riber (2007)). Plusieurs modèles proposés récemment par Masi (2010) et qui ont été valides a priori dans une configuration de nappe chargée de particules sont validés a posteriori dans la même configuration. Un analyse quantitative sur plusieurs cas avec diffèrent nombres de Stokes, nombres de Reynolds de la phase gazeuse et résolutions du maillage ont permit de retenir un modèle non-linéaire nommé 2EASM3, qui utilise le tenseur de déformations de la phase dispersée comme échelle de temps caractéristique. La deuxième partie a pour but l'amélioration du modèle d'évaporation implémenté dans AVBP. Ce modèle suppose une conduction infinie dans la phase liquide et symétrie sphérique dans la phase gazeuse ainsi que des lois simplifiées pour les propriétés thermodynamiques et de transport. Un nouveau modèle prenant en compte la dépendance de la viscosité du mélange gazeux avec la composition locale, et des nombres de Prandtl et Schmidt fixés par les valeurs à l'équilibre obtenus par moyen d'une simulation prenant en compte des lois complèxes pour les propriétés thermodynamiques et de transport est proposé. Cette nouvelle méthode produit des résultats en bon accord avec les mesures expérimentales pour l'évaporation d'une goutte isolé en une atmosphère d'azote au calme sans pourtant augmenter le cout du calcul. Finalement, l'impacte des nouveaux modèles est analysé dans une SGE de la configuration semi-industrielle MERCATO (García-Rosa (2008)). Bien que les données expérimentales ne soient pas suffisantes pour confirmer les résultats, les distributions de gouttes et de carburant gazeux sont significativement affectés par les modèles, ce qui pourrait avoir un impact directe sur le procès d'allumage. / Combustion still represents about 90% of the energy production in the world. Most industrial burners are fuelled with liquid hydrocarbons. However, most studies have been dedicated to gaseous ßames and the impact of liquid spray is still misunderstood. The purpose of this study is to improve the modelisation of two main phenomena occurring between atomization and combustion, i.e. the droplet dispersion in the turbulent gaseous flow and the evaporation process, in the context of Large Eddy Simulation (LES) of complex configurations. First, the mesoscopic Euler-Euler approach (Février et al. (2005)) based on a conditioned ensemble averaging and implemented in AVBP is improved. The closure model (Simonin et al. (2001), Kaufmann (2004)) for the second-order moments appearing in the transport equations solved fails in mean-sheared configurations (Riber (2007)). Several new models proposed by Masi (2010) and a priori tested in a particle-laden slab are tested a posteriori in the same configuration. A quantitative analysis based on several calculations varying the Stokes number, the gaseous Reynolds number and the grid resolution allows to retain a non-linear model using the particle rate-of-strain tensor as timescale and called 2EASM3. The second part consists in improving the evaporation model implemented in AVBP which assumes infinite conduction in the liquid and spherical symmetry in the gas phase along with simplified thermodynamics and transport properties calculation. A new model is proposed, where the dependence of gaseous mixture viscosity on local composition is accounted for, and the Prandtl and Schmidt numbers are fixed by a reference equilibrium calculation using complex thermodynamics and transport properties. This method shows good agreement with experimental measurements in the configuration of an isolated droplet evaporating in quiescent N2 without further increasing the computational cost. Finally, the impact of the new models is analysed in the LES of the MERCATO semi-industrial configuration (García-Rosa (2008)). Although the experimental data are not sufficient to confirm the results, both the droplet distribution and the fuel mass fraction are significantly affected, which would eventually affect the ignition process.

No description available.

Orientador: Geraldo Nunes Silva / Banca: Orizon Pereira Ferreira / Banca: Fernando Manuel F. Lobo Pereira / Resumo: O objetivo deste trabalho é o estudo do sistema de controle impulsivo de [Wolenski e šZabi'c 2007] para o caso em que o sistema é dado por uma igualdade e modificado pela adição de dois controles abstratos. Tal estudo foi feito utilizando duas abordagens. Na primeira, reparametrizamos o sistema inicial a partir da função distribuição relacionada à medida atômica e, através da discretização de Euler do sistema reparametrizado, obtemos uma sequência de soluções que converge no gráfico para a solução do sistema original, sob algumas hipóteses. Na segunda abordagem, definimos um novo sistema associado a uma sequência de medidas absolutamente contínuas que converge no gráfico para a medida atômica. A partir desse novo sistema, obtemos uma sequência de soluções com a propriedade de convergência no gráfico da solução do sistema original / Abstract: The aim of this work is to study the impulsive control system of [ Wolenski e šZabic 2007] to the case where system is given by an equality and modified by addition of two abstract controls. The study was done using two approaches. At first, we've reparameterized the initial system from distribution function related to atomic measure and, through Euler's discretization of reparameterized system, we've obtained a sequence of solutions which graph converge to the solution of original system, under some hypothesis. In the second approach, we've defined a new system associated with a sequence of absolutely continuous measures which graph converge to atomic measure. From this new system, we've obtained a sequence of solutions with the graph convergence prop erty of the solution of the original system / Mestre

Made available in DSpace on 2015-03-03T15:36:13Z (GMT). No. of bitstreams: 1 OdilonJS_DISSERT.pdf: 1624865 bytes, checksum: f08c3087f93d38a7f0eca20c25b43940 (MD5) Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this paper we analyze the Euler Relation generally using as a means to visualize the fundamental idea presented manipulation of concrete materials, so that there is greater ease of understanding of the content, expanding learning for secondary students and even fundamental. The study is an introduction to the topic and leads the reader to understand that the notorious Euler Relation if inadequately presented, is not sufficient to establish the existence of a polyhedron. For analyzing some examples, the text inserts the idea of doubt, showing cases where it is not fit enough numbers to validate the Euler Relation. The research also highlights a theorem certainly unfamiliar to many students and teachers to research the polyhedra, presenting some very simple inequalities relating the amounts of edges, vertices and faces of any convex polyhedron, which clearly specifies the conditions and sufficient necessary for us to see, without the need of viewing the existence of the solid screen. And so we can see various polyhedra and facilitate understanding of what we are exposed, we will use Geogebra, dynamic application that combines mathematical concepts of algebra and geometry and can be found through the link http://www.geogebra.org / Neste trabalho, analisamos a Rela??o de Euler de uma maneira geral, utilizando, como meios de visualiza??o, a manipula??o de materiais concretos, a fifim de que haja maior facilidade na percep??o do conte?do, expandindo a aprendizagem aos alunos de n?vel m?dio e at? fundamental. O estudo faz uma introdu??o ao tema e leva o leitor a entender que a Rela??o de Euler, se apresentada de maneira inadequada, n?o ? sufificiente para determinar a exist?ncia de um poliedro. Pois, analisando alguns exemplos, o texto insere a id?ia de d?vida, mostrando casos onde n?o ? sufificiente encaixar n?meros que validem a Rela??o de Euler. A pesquisa destaca ainda um teorema, certamente desconhecido de muitos alunos e professores que pesquisam sobre os poliedros, apresentando algumas inequa??es muito simples, relacionando as quantidades de arestas, v?rtices e faces de qualquer poliedro convexo, as quais definem de forma precisa as condi??es sufificientes e necess?rias para que possamos constatar, sem a necessidade da visualiza??o, a exist?ncia do s?lido em tela. E para que possamos visualizar v?rios poliedros e facilitar a compreens?o do que estamos expondo, utilizaremos o Geogebra, aplicativo de matematica din?mica que combina conceitos de geometria e alg?bra e pode ser encontrado por meio do link http://www.geogebra.org

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Polyhedra are geometric solids formed by a finite number of polygons they can be convex or non-convex, regular or not regular. This work we make three demonstrations of Eulerâs theorem for polyhedra in one plane being used graphs. We will adopt preliminary definitions of polygons, polyhedra and graphs and make a brief study of the theorem before the demonstrations analysis when the theorem is valid and what conditions exist polyhedra, since the theorem is accepted. The work brings some applications in the form of questions in the theory presented. / Os poliedros sÃo sÃlidos geomÃtricos formados por uma quantidade finita de polÃgonos. Eles podem ser convexos ou nÃo convexos, regulares ou nÃo regulares . Neste trabalho fazemos trÃs demonstraÃÃes do teorema de Euler para poliedros no plano, sendo uma utilizado grafos. Adotaremos definiÃÃes preliminares de polÃgonos, poliedros e grafos e faremos um breve estudo do teorema antes das demonstraÃÃes analisado quando o teorema à valido em quais condiÃÃes existem os poliedros, uma vez que o teorema à aceito. O trabalho traz algumas aplicaÃÃes em forma de questÃes da teoria apresentada.