Orientador: Silvia Maria Giuliatti Winter / Banca: Ernesto Vieira Neto / Banca: Ricardo Reis Cordeiro / Resumo: Plutão e Caronte, bem como os novos satélites do sistema, Nix e Hidra, são alvos de micrometeoritos, provavelmente originários do cinturão de Kuiper. Os resíduos destes impactos permaneceriam no sistema em órbitas ao redor de Plutão ou Caronte. Este estudo analisa, através de simulações numéricas, a estabilidade das regiões ao redor do sistema binário. Esta análise deu-se através de simulações numéricas para o problema restrito de três corpos. Foram numericamente integradas órbitas para partículas ao redor de Plutão, ao redor de Caronte e ao redor do baricentro do sistema. Dessas integrações numéricas foram geradas grades a x e, definindo-se regiões: de estabilidade, de escape e de colisão. A região estável ao redor de Plutão vai até aproximadamente 8200km, ao redor de Caronte se estende até 2900km e ao redor do baricentro do sistema binário, órbitas Tipo-P, a região estável inicia-se a partir de 49000km. Estes valores estão de acordo com a teoria de Holman e Wiegert (1999). As regiões de estabilidade de Plutão Caronte foram também amplamente estudadas através do uso da Superfície de Secção de Poincaré (SSP). Um conjunto de cerca de 230 SSP foi obtido. Foram gerados diagramas de Cjxx, Cj é o valor da Constante de Jacobi, derivados das SSP para a região interna aos corpos massivos do binário e externa a eles. Estes diagramas representam a síntese da análise da estabilidade por meio das SSP. Neles ficam determinadas as regiões estáveis às partículas no sistema. Cojuntos especiais de SSP foram gerados para análise das ressonâncias 1:6 e 1:4, pois estas, em especial, estariam relacionadas aos novos satélites. Verificou-se que estes satélites estão em regiões estáveis, mas não em ressonância de acordo com o dados até hoje conhecidos. / Abstract: Pluto and Charon and the two new discovered satellites, named Hydra and Nix, are targets of micrometeorites which were probably originated from the Kuiper belt. A sample of particles can be generated from these collision and be trapped in orbit around Pluto or Charon. This work analyses, through numerical simulations, the stable regions around the binary system. This analysis took into account the Restricted Three Body Problem. From these numerical simulations diagrams of a x e were generated defining, stable, escape and unstable regions. Stable regions around Pluto (width about 8200km), around Charon (width about 2900km) and around the baricentre of the binary system (after a semi-major axis about 49000km) were obtained. These values are in good agreement with the work by Holman & Wiegert (1999). These stable regions were also analysed by using the technique of POincaré Surface of Section (PSS). A sample of about 230 PSS was obtained. In all these PSS chaotic and stable regions and also the resonance locations were identified. Diagrams of Cj x x, derived from the PSS, were obtained. They represent the synthesis of the stability region acquired from the PSS. A particular set of SSP was generated in order to analyse the evolution of 1:4 and 1:6 resonances. The new satellites, Hydra and Nix, are located in stable regions although, they are not in resonances with Charon, as can be seen in the grade a x e. / Mestre

Classical Cepheids and eclipsing binary systems are powerful probes for measuring stellar fundamental parameters and constraining stellar astrophysics. A Cepheid in an eclipsing binary system is even more powerful, constraining stellar physics, the distance scale and the Cepheid mass discrepancy. However, these systems are rare, only three have been discovered. One of these, OGLE-LMC-CEP1812, presents a new mystery: where the Cepheid component appears to be younger than its red giant companion. In this work, we present stellar evolution models and show that the Cepheid is actually product of a stellar merger during main sequence evolution that causes the Cepheid to be a rejuvenated star. This result raises new questions into the evolution of Cepheids and their connections to smaller-mass anomalous Cepheids.

The purpose of this study was to gain knowledge about how people who identify themselves outside the gender binary system look upon treatment from people in different contexts and how the strategies they use in relation to treatment are expressed. As an approach to this study, we chose to do a qualitative internet study, the empirical material included ten various blogs written by people who identify themselves outside the gender binary system. By using a content analysis we were able to distinguish themes concerning good and bad treatment as well as different forms of coping in our empirical material. The analysis was based on two different kinds of perspectives: queer theory and the concept of coping strategies. The result of this study showed that people who identify themselves outside the gender binary system experience poor treatment more often than good treatment from people in different contexts. One important result that this study showed was that most people described that they felt reduced and ridiculed by, for example, government officials and family members because of their gender identity. We also found that the people in this study used different strategies to cope with the poor treatment they received. A strategy that most of the people in the study used to avoid being treated badly were dressing in gender-neutral clothes. The main conclusion of the study is that it is important that we humans do not assume that all persons belong to the gender binary system. More knowledge about the area is needed to enable us to treat people who identify outside the gender binary system adequately.

O objetivo deste trabalho é mostrar que variados cálculos tornam-se mais fáceis de ser efetuados realizando operações com números escritos na base dois, com o pressuposto de que se esteja habituado a números nessa base, promovendo um aprofundamento na compreensão das bases e das propriedades utilizadas nas operações. Retomaremos alguns dos principais sistemas de numeração e apresentamos os cálculos de adições, subtrações, multiplicações e divisões com números escritos na base binária. Resgataremos também um antigo, porém eficiente, algoritmo para a extração de raízes quadradas. / The purpose of this work is to show that various calculations become easier to perform by performing operations with numbers written in base two, with the assumption that one is accustomed to numbers in this base, promoting a deeper understanding of the bases and properties used for these operations. We will return to some of the major numbering systems and present the calculations of sums, subtractions, multiplications, and divisions with numbers written on the binary basis. We will also rescue an old but efficient algorithm for the extraction of square roots.

La détection ainsi que l’analyse des ondes gravitationnelles émises par les systèmes binaires d’objets compacts reposent sur notre capacité à faire des prédictions précises au sein de la théorie de la relativité générale. Dans cette thèse, nous utilisons la théorie post-newtonienne (PN), et en particulier le formalisme connu sous le nom de Blanchet-Damour-Iyer, afin d’étudier de tels systèmes. La finalité des différents calculs réalisés au sein de cette thèse est d’obtenir la phase du signal gravitationnel à l’ordre 4,5PN, et les résultats que nous présentons nous rapprochent fortement de cet objectif. Tout d’abord, nous calculons les sillages d’ondes à l’ordre 3 dans le champ radiatif, ce qui nous permet d’obtenir le coefficient 4,5PN du flux d’énergie émis par des systèmes binaires compacts sans spin dans le cas d’orbites circulaires. Puis, nous calculons la dernière ambiguïté apparaissant dans les équations du mouvement de deux corps compacts sans spin à l’ordre 4PN, ce qui nous permet d’obtenir la première dérivation à partir de principes fondamentaux de ce résultat. Nous étudions alors en détail les différentes quantités conservées générées par cette dynamique. Enfin,nous présentons un premier résultat préliminaire du quadrupôle de masse source à l’ordre 4PN, ce qui constitue l’une des étapes cruciales dans l’obtention de la phase à l’ordre 4.5PN. / The detection and the analysis of gravitational waves emitted by compact binary systems rely on our ability to make accurate predictions within general relativity. In this thesis, we use the post-Newtonian (PN) formalism, and in particular the Blanchet-Damour-Iyer framework, to study the dynamics and the emission of gravitational waves of such systems. The different computations that we performed are motivated by our aim to obtain the phase of the gravitational wave signal at the 4.5PN order. In that regard, crucial steps have been achieved within this thesis. First of all, we compute the third-order tail effects in the radiation field, yielding the 4.5PN coefficient of the energy flux for binaries of non-spinning objects in circular orbits. Besides, we determine the remaining ambiguity of the 4PN Lagrangian of two spinless compact bodies. This result completes the first derivation from first principles of the 4PN equations of motion. Then we comprehensively study the conserved quantities of the 4PN dynamics. Finally, we provide a preliminary result of the 4PN source mass quadrupole, which constitutes one of the crucial steps towards the computation of the 4.5PN phase.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O objetivo deste trabalho à estudar as propriedades estruturais e dinÃmicas de um sistema binÃrio clÃssico consistindo de partÃculas carregadas que estÃo confinadas em um canal bidimensional. Tal sistema à descrito na literatura como quasi-unidimensional, e esta relevÃncia apoia-se na possibilidade de aplicaÃÃes tecnolÃgicas, como tem sido mostrado recentemente na literatura cientÃfica, bem como no interesse e entendimento em propriedades da FÃsica da matÃria condensada. Apesar do carÃter teÃrico do presente estudo, diversos sistemas experimentais podem ser descritos pelo modelo aqui considerado. O resumo do conteÃdo deste trabalho à apresentado em cada capÃtulo. No capÃtulo 1, à dada uma visÃo geral do presente trabalho. O conceito da cristalizaÃÃo de Wigner à introduzido e sÃo dados exemplos de sistemas experimentais, que exibem uma fase ordenada sob circunstÃncias apropriadas. Discute-se a FÃsica dos plasmas complexos, das suspensÃes coloidais e aplicaÃÃes em sistemas biolÃgicos. Uma descriÃÃo do mÃtodo de simulaÃÃo à dada no capÃtulo 2. As transformaÃÃes de escalas sÃo introduzidas a fim de construir um modelo geral, isto Ã, nÃo dependente das caracterÃsticas particulares do sistema, mas somente das quantidades relevantes gerais. Apresenta-se a tÃcnica de simulaÃÃo por DinÃmica Molecular (DM), focalizando tambÃm a DinÃmica de Langevin. A competiÃÃo entre a interaÃÃo entre partÃcula, na forma de repulsÃo eletrostÃtica, e o confinamento externo, que à suposto parabÃlico e age somente em uma direÃÃo, gera uma estrutura de cadeias no sistema. Uma descriÃÃo do modelo, bem como a aproximaÃÃo harmÃnica utilizada para o cÃlculo dos modos normais e o cÃlculo da energia por partÃcula das vÃrias estruturas de cadeias sÃo dadas no capÃtulo 3. A configuraÃÃo do estado fundamental, as transiÃÃes estruturais de fase e modos normais para o sistema binÃrio de cadeias sÃo examinadas no capÃtulo 4. Para baixas densidades as partÃculas cristalizam-se em uma Ãnica cadeia; com o aumento da densidade uma transiÃÃo zig − zag ocorre e a Ãnica cadeia se parte em duas. Observa-se que esta transiÃÃo estrutural à caracterizada por uma quebra espontÃnea de simetria. Com o aumento da densidade, o sistema passa para quatro cadeias (caso 1) (partÃculas nÃo alinhadas na vertical), onde a transiÃÃo de duas para quatro cadeias (caso 1) ocorre com uma transiÃÃo zig − zag, em cada uma das cadeias, acompanhadas por um deslocamento ao longo da direÃÃo da cadeia. EntÃo com um aumento da densidade conduzirà a uma nova estrutura de quatro cadeias (caso 2) (partÃculas alinhadas na vertical). As propriedades dinÃmicas aqui consideradas resumem-se ao espectro de fÃnons, no qual o nÃmero de modos normais à igual ao dobro do nÃmero de partÃculas na cÃlula unitÃria. As conclusÃes e perspectivas sÃo apresentadas no capÃtulo 5. / The aim of this work is to study the structural and dynamical properties of a classical binary system of charged particles confined in a two dimensional channel. Such a system is described in the literature as quasi-unidimensional, and its relevance is supported by the possibility of technological applications, shown recently in the scientific literature, and also the interest and understanding of properties in condensed matter physics. Although the theoretical and numerical character of the present work, several experimental systems can be described by the present model. The summary of the contents of this work is presented in each chapter. In chapter 1, a general overview is given. The concept of Wigner crystallization is introduced, and examples of experimental systems, which exhibit such an ordered phase under proper conditions are given. We discuss the physics of complex plasmas, colloidal suspensions and applications in biological systems. A description of the simulation method is given in chapter 2. Scale transformations are introduced in order to construct a general model, i.e. no longer depending on particular features of the system, but only on relevant parameters of a general model. The Molecular Dynamics simulation technique (MD) is presented, focusing on the Langevin Dynamics. The competition between the inter-particle interaction, in the form of the electrostatic repulsion, and the external confinement, which is assumed to be parabolic and act only in one direction, generates a chain-like strutural pattern. A description of the model, the harmonic approach used in the analytical calculations of the normal modes spectrum, and the analytical calculation of the energy per particle of the different chain-configutations are given in chapter 3. The ground state configurations, the structural phase transitions and normal modes of the present chain-like binary system are presented in Chapter 4. In the low density regime particles crystallize in a single chain. When the density is increased a zig-zag transition occurs and the single chain splits into two chains. Such a transition is characterized by a spontaneous symmetry breaking. With the increase of the density the system changes to the four-chains configuration (case 1) (particles not aligned vertically), where the two -> four chains (case 1) transition occurs through a zig-zag transition accompanied by a shift along the chain direction. A further increase of the density will lead the system to a new ground state configuration with four chains (case 2) (particles aligned vertically). The dynamical properties are related to the phonon spectrum, in which the number of normal modes is two times the number particle in the unit cell. The conclusions and perspectives are presented in chapter 5.

O objetivo deste trabalho é mostrar que variados cálculos tornam-se mais fáceis de ser efetuados realizando operações com números escritos na base dois, com o pressuposto de que se esteja habituado a números nessa base, promovendo um aprofundamento na compreensão das bases e das propriedades utilizadas nas operações. Retomaremos alguns dos principais sistemas de numeração e apresentamos os cálculos de adições, subtrações, multiplicações e divisões com números escritos na base binária. Resgataremos também um antigo, porém eficiente, algoritmo para a extração de raízes quadradas. / The purpose of this work is to show that various calculations become easier to perform by performing operations with numbers written in base two, with the assumption that one is accustomed to numbers in this base, promoting a deeper understanding of the bases and properties used for these operations. We will return to some of the major numbering systems and present the calculations of sums, subtractions, multiplications, and divisions with numbers written on the binary basis. We will also rescue an old but efficient algorithm for the extraction of square roots.

Nous présentons la découverte de quatorze nouveaux systèmes binaires ayant une séparation supérieure à 250 UA et dont au moins l'une des composantes est une naine M ou une naine L. Ces systèmes ont d'abord été identifiés en cherchant des objets ayant un mouvement propre commun autour d'étoiles connues possédant un mouvement propre élevé, grâce à une corrélation croisée de grands relevés du ciel dans l'infrarouge proche (2MASS, SDSS et SIMP). Un suivi astrométrique, afin de confirmer le mouvement propre commun, a été réalisé sur toutes les cibles avec la caméra SIMON et/ou la caméra CPAPIR à l'Observatoire du Mont-Mégatic (OMM) ou à l'Observatoire interaméricain du Cerro Tololo (CTIO). Un suivi spectroscopique a aussi été effectué sur la plupart des compagnons avec GMOS ou GNIRS à Gemini afin de déterminer leurs types spectraux. La probabilité que deux objets forment un système binaire par hasard a été évaluée afin de s'assurer que les couples candidats que nous présentons soient réellement liés.Un de nos nouveaux systèmes a un compagnon de masse sous-stellaire : 2M1259+1001 (L4.5). L'étude des systèmes que nous avons découverts pourra, entre autre, nous aider à mieux comprendre les mécanismes de formation des étoiles de très faible masse et des naines brunes. / We report the discovery of 14 new low-mass binary systems containing mid-M to mid-L dwarf companions with a separation larger than 250 AU. These systems were first identified by searching for common proper motion sources in the vicinity of known high proper motion stars, based on a cross-correlation of wide area near-infrared surveys (2MASS, SDSS, and SIMP). An astrometric follow-up, for common proper motion confirmation, was made with SIMON and/or CPAPIR at the Observatoire du Mont-Mégantic (OMM) and Cerro Tololo Inter-American Observatory (CTIO) telescopes for most of the candidates identified. A spectroscopic follow-up was also made with GMOS or GNIRS at Gemini to determine their spectral types. Statistical arguments are provided to show that all of the systems we report here are very likely to be truly bound. One of the new systems we discovered has a brown dwarf companion: 2M1259+1001 (L4.5). The study of the new systems we have discovered will be useful to help us better understand how very low mass stars and brown dwarfs form.