Heidelberg, Univ., Diss., 2001. / Dateien im PDF-Format. Computerdatei im Fernzugriff.

Heidelberg, Univ., Diss., 2001. / Dateien im PDF-Format. Computerdatei im Fernzugriff.

Zugl.: München, Univ. der Bundeswehr, Diss., 2010

Heidelberg, University, Diss., 2001. / Dateien im PDF-Format.

Active Galactic Nuclei (AGN) are cores of distant protogalaxies, with a supermassive blackhole at the center surrounded by an accretion disk, and bipolar jets. Blazars, a subset of AGN, have their jets aligned with our line of sight. Emission from blazars is highly variable on all timescales and frequencies. Microvariability refers to rapid continuum variations that arise within the jet. Bhatta et al. (2013) suggest a modified Kirk, Rieger, \& Mastichiadis (1998) model (KRM) to explain microvariability. The KRM model assumes that when shock waves passes though the jet, each turbulent cell encountered produces a pulse of emission characterized by cell size, local density enhancement, and magnetic field strength. NASA's \kepler\ has monitored optical emission from four AGN. We use the modified KRM model to analyze micro-variations in these \kepler\ data. The distribution of cell sizes computed from these data is consistent with the distribution expected from a turbulent plasma.

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Submitted by MARCOS LUCHIARI BARALDI (marcosbrld@yahoo.com.br) on 2018-09-12T03:42:53Z No. of bitstreams: 1 DISSERTAÇÃO-12.09.18.pdf: 3346423 bytes, checksum: a92ab36f4ef9b546a9685be711a2f4b5 (MD5) / Approved for entry into archive by Elza Mitiko Sato null (elzasato@ibilce.unesp.br) on 2018-09-12T13:24:07Z (GMT) No. of bitstreams: 1 baraldi_ml_me_sjrp.pdf: 3346423 bytes, checksum: a92ab36f4ef9b546a9685be711a2f4b5 (MD5) / Made available in DSpace on 2018-09-12T13:24:07Z (GMT). No. of bitstreams: 1 baraldi_ml_me_sjrp.pdf: 3346423 bytes, checksum: a92ab36f4ef9b546a9685be711a2f4b5 (MD5) Previous issue date: 2018-08-03 / Este trabalho apresenta uma verificação de uma das relações mais importantes da matemática elementar: a relação de Euler. Ela expressa uma relação entre o número vértices, arestas e faces de poliedros convexos, podendo ser estendida aos poliedros estrelados, particularmente aos de Kepler-Poinsot. Para analisar tal relação, a proposta é utilizar material concreto, como jujubas, canudos e varetas de fibra. A princípio é realizada a construção dos poliedros de Platão, canudos rígidos e coloridos, onde é possível verificar com facilidade a veracidade da Relação de Euler. Na sequência utilizam-se as varetas de fibra de vidro 1,4 mm que com a introdução nas arestas dos poliedros, verifica-se facilmente que apenas o dodecaedro e o icosaedro são passíveis da estrelação, por prolongamento das arestas obtendo assim, dois dos poliedros estrelados de Kepler-Poinsot. Por fim, é analisado que a Relação de Euler, também se verifica para esses estrelados. Com tal procedimento fica mais perceptível a não existência de outros poliedros estrelados, pois a partir de sua construção com canudos e a ampliação de suas arestas com varetas fica claro a não intersecção delas. Vale lembrar que tais atividades lúdicas são incentivadas no ensino da matemática e algumas já foram abordadas em dissertações do PROFMAT e em documentos oficiais de ensino no Brasil, como nos Parâmetros Curriculares Nacionais, no Currículo do Estado de São Paulo, matrizes de referências de avaliações tais como: Saresp (Sistema de avaliação de rendimento escolar do estado de São Paulo), Saeb (Sistema nacional de avaliação do ensino básico) e ENEM (Exame nacional do ensino médio). / This paper presents a verification of one of the most important relations of elementary mathematics: Euler's relation. It expresses a relation between the number of vertices, edges and faces of convex polyhedra, and can be extended to the starry polyhedra, particularly to those of Kepler-Poinsot. To analyze this relationship, the proposal is to use concrete material, such as jelly beans, straws and fiber rods. At first the construction of Plato's polyhedrons, rigid and colored straws, is carried out, where it is possible to verify with ease the veracity of the Euler Relation. The 1.4 mm glass fiber rods are then used which, with the introduction of polyhedron edges, can easily be verified that only the dodecahedron and the icosahedron are capable of staring by prolonging the edges, thus obtaining two of the polyhedra starring Kepler-Poinsot. Finally, it is analyzed that the relation of Euler, also is verified for these stars. With such a procedure it is more noticeable the existence of other starry polyhedra, since from its construction with straws and the enlargement of its edges with rods it is clear the nonintersection of them. It is worth remembering that such play activities are encouraged in the teaching of mathematics and some have already been addressed in PROFMAT dissertations and in official teaching documents in Brazil, such as in the National Curriculum Parameters, in the Curriculum of the State of São Paulo, references reference matrices such as: Saresp (System of evaluation of school performance of the state of São Paulo), Saeb (National system of evaluation of basic education) and ENEM (National High School Examination).

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-11-12T00:19:22Z No. of bitstreams: 1 Disserta??o Paulo Henrique Portela Oliveira vers?o final.pdf: 1348341 bytes, checksum: 70d99d7cd73a18ebb8bab0aac9f5e921 (MD5) / Made available in DSpace on 2015-11-12T00:19:22Z (GMT). No. of bitstreams: 1 Disserta??o Paulo Henrique Portela Oliveira vers?o final.pdf: 1348341 bytes, checksum: 70d99d7cd73a18ebb8bab0aac9f5e921 (MD5) Previous issue date: 2015-08-31 / The Physics textbooks constitute the main teacher's working tool, although surveys indicate the need to prepare own teaching materials prepared by the teacher and the use of the textbook as support.We conducted a study of Kepler's Laws of Planetary Motion in Physics textbooks recommended by the National Textbook Program (PNLD in Portuguese) in 2014. The main objective is to verify how that content is addressed in these works. We use as conceptual, didactic-methodological and historical aspects analysis criteria. They are linked to that recommended by the PNLD Guide, the National Curriculum Guidelines for Secondary Education, and academic papers that focus urges that a History of Science in teaching Physics.The methodologywasqualitative in nature. We analyzed the 14 books of PNLD by analysis of the content. Based on our investigation, we concluded that the definition of concepts considered important for the understanding of the laws is not yet satisfied. We highlight the omission, in some books, the concept of the ellipse, which constitutes a basic element for learning content. Analysis of didactic and methodological aspects showed that contextualization is not included in the approach taken by textbooks, and interdisciplinary is attuned to the purpose of integrating the different areas of knowledge. About to the use of the History of Science, although it has an important role in learning in physics, is not present. There is no a concern with this aspect by most authors. / Os livros did?ticos de F?sica constituem o principal instrumento de trabalho do professor, apesar de algumas pesquisas recomendarem a necessidade da elabora??o de material did?tico pelo pr?prio professor e do uso do livro-texto como apoio. Realizo um estudo sobre as Leis de Kepler do Movimento Planet?rio nos livros did?ticos de F?sica recomendados pelo Programa Nacional do Livro Did?tico (PNLD) no ano de 2014. O principal objetivo foi verificar de que forma esse conte?do se encontra abordado nestas obras. Utilizo como crit?rios de an?lise aspectos conceituais, did?tico-metodol?gicos e hist?ricos. Os mesmos encontram-se atrelados ao que preconiza o Guia de Livros Did?ticos da Disciplina F?sica do PNLD, nas Diretrizes Curriculares Nacionais para o Ensino M?dio e em trabalhos acad?micos cujos enfoques defendem a inclus?o da Hist?ria da Ci?ncia no Ensino de F?sica. A metodologia utilizada foi de natureza qualitativa. Avalioos 14 livros do PNLD, ? luz da An?lise do Conte?do. Com base na nossa investiga??o, concluo que a defini??o de conceitos considerados importantes para a compreens?o das leis ainda n?o ocorre de forma satisfat?ria. Destaco a omiss?o, em alguns livros, do conceito da elipse, que se constitui em um elemento b?sico para o aprendizado do conte?do. A an?lise dos aspectos did?tico-metodol?gicos evidenciou que a contextualiza??o n?o ? contemplada na abordagem feita pelos livros did?ticos, e a interdisciplinaridade encontra-se em sintonia com o prop?sito de integrar as diferentes ?reas do conhecimento. Com respeito ao uso da Hist?ria da Ci?ncia, embora possua um relevante papel no aprendizado em F?sica, ela n?o est? presente, pois n?o h? uma preocupa??o com esse aspecto pela maioria dos autores.

Cette thèse propose une étude des raisons théoriques et empiriques impliquées dans l’élaboration d’une nouvelle astronomie par Johannes Kepler (1571-1630) tel qu’exposé dans son ouvrage Astronomia nova (1619). Cette thèse se déroule en deux temps : la première partie touche de près aux textes mêmes de Kepler, tandis que la seconde partie utilise la notion d’abduction pour interpréter logiquement ce processus de découverte et de justification. La première partie débute avec une analyse du projet de Kepler et de ses fondements philosophiques, métaphysiques et théologiques tels qu’exposés dans son premier ouvrage, le Mysterium cosmographicum. Ensuite, une étude des propos explicites de Kepler quant à la nature et au statut des hypothèses astronomiques est proposée via une étude de son traité intitulé Apologia pro Tychone contra Ursum. Une étude attentive des sources philosophiques, mathématiques et scientifiques ayant influencé Kepler pour sa nouvelle astronomie est ensuite proposée avant l’analyse détaillée des arguments scientifiques et des différentes étapes démonstratives qui sont présentés dans l’Astronomia nova. La deuxième partie vise à éclairer le débat sur l’abduction en se penchant d’abord sur trois approches traditionnelles (Platon, Aristote et Épicure) quant à la connaissance scientifique des phénomènes célestes permettant d’obtenir un discours vraisemblable ou une multiplicité d’explications concordantes avec les phénomènes. Enfin, quatre interprétations contemporaines et abductives du processus de découverte suivi par Kepler dans l’Astronomia nova sont présentées, reformulées et critiquées afin de proposer une nouvelle interprétation abductive laissant une plus grande place au projet même de construire une astronomie nouvelle fondée sur les causes. Cela nous donne des outils pour mieux saisir le sens et la portée de ce qui peut être désigné comme étant la « révolution képlérienne », soit le passage d’un système géocentrique à un système non pas simplement héliocentrique mais héliodynamique, ayant permis aux astronomes de s’affranchir du paradigme des orbites circulaires. / This thesis offers a study of the theoretical and empirical reasons involved in the elaboration of a new astronomy by Johannes Kepler (1571-1630) as displayed in his work Astronomia nova (1619). The thesis consists of two parts: the first part deals with Kepler’s actual writings, whereas the second part uses the notion of abduction in order to interpret with logic that process of discovery and justification. The first part begins with an analysis of Kepler’s project and its philosophical, metaphysical and theological foundations as displayed in his first work piece, Mysterium cosmographicum. Then follows a review of Kepler’s own words regarding the nature and status of astronomical hypotheses as proposed through a study of his treatise entitled Apologia pro Tychone contra Ursum. A careful study of philosophical, mathematical and scientific sources that have influenced Kepler for his new astronomy is then proposed prior to a detailed analysis of the scientific arguments and different demonstrative steps that are presented in Astronomia nova. The second part aims at enlightening the debate on abduction first by looking at three traditional approaches (Plato, Aristote and Epicurus) relative to the scientific knowledge of celestial phenomena that bring about a plausible discourse or a series of explanations that fit with the phenomena. Finally, four modern abductive interpretations of the discovery process followed by Kepler in Astronomia nova are presented, reformulated and reviewed in order to propose a new abductive interpretation that leave a greater place to the actual project of building a new astronomy based on causes. This provides tools to better understand the meaning and significance of what can be understood as the “Keplerian revolution”, namely the transition from a geocentric system to a system not simply heliocentric but heliodynamic, which freed astronomers from the paradigm of circular orbits.

La recherche et caractérisation de planètes extrasolaires en transit (i.e., qui passent devant leur étoile, vue depuis la Terre) est un domaine important de la planétologie car ces planètes permettent de contraindre les processus de formation, d'évolution et de migration des systèmes planétaires. Les missions spatiales CoRoT et Kepler ont permis, ces dernières années, de découvrir plusieurs milliers de candidats-planètes en transit. Cependant, ces candidats-planètes doivent être confirmés afin d'exclure tout scénario de faux-positifs pouvant imiter un transit d'une exo-planète. Pour cela, l'une des méthodes possible consiste à mener des observations complémentaires de vitesse radiale permettant de mesurer la masse et les paramètres orbitaux de l'objet qui transite et ainsi de pouvoir déterminer la nature des candidats-planètes. Au cours de ma thèse, je me suis attaché à résoudre la nature des candidats-planètes en transit issues des missions spatiales CoRoT et Kepler en menant des observations avec les spectrographes SOPHIE et HARPS, ce qui m'a permis d'identifier plusieurs nouvelles planètes extrasolaires en transit. J'ai également pu mesurer le taux de faux-positif de la mission Kepler, égal à 35% pour les candidats planètes-géantes à courte période orbitale, contredisant les précédentes estimations, beaucoup plus optimistes. J'ai également participé au développement d'un nouveau logiciel, "PASTIS", qui permet de valider statistiquement des planètes extrasolaires de faible masse, trop petites pour être caractérisées grâce aux spectrographes actuels. Ce logiciel permettra, à terme, de valider des dizaines de planètes de faible masse issues des missions CoRoT et Kepler. / The search and characterization of transiting extrasolar planets (i.e. that pass in front of their host star, as seen from the Earth) is an important domain of planetology since these planets constrain the formation, evolution and migration process of planetary systems. The CoRoT (CNES) and Kepler (NASA) space missions permit, these last years, to discover several thousand of transiting-planet candidates. However, these planet candidates need to be confirmed in order to exclude all false positive scenario that can mimic a planetary transit. For that, one of the method consist on performing radial velocity follow-up observations to measure the transiting object's mass and orbital parameters and thus, to determine the nature of planet candidates.During my PhD thesis, I tried to resolve the nature of transiting planet candidates from the CoRoT and Kepler space missions. For that, I performed follow-up observations with the SOPHIE (OHP) and HARPS (ESO) spectrographs that were used to discover several new transiting extrasolar planets. I also measured the Kepler false-positive rate, equal to 35% for giant close-in exoplanet candidates, contradicting previous estimations, much more optimistic.I also participate to the development of a new software, called "PASTIS", which objective is to validate statistically low-mass transiting exoplanets out of reach for current spectrographs. This new tool will, in a near future, validate tens of low-mass planets from the CoRoT and Kepler space missions.