Orientador: Edmundo Capelas de Oliveira / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-15T07:12:57Z (GMT). No. of bitstreams: 1 Rodrigues_FabioGrangeiro_M.pdf: 2473878 bytes, checksum: edf9dfdf8d0b07b971df24b68798f67f (MD5) Previous issue date: 2010 / Resumo: Neste trabalho é dada uma prova de equivalência entre diferentes formas de se escrever a lei de Faraday. a forma integral e a diferencial. Nosso objetivo é esclarecer alguns pontos relevantes da prova dessas equivalências que são normalmente apresentadas nos livros textos de Física apenas para casos muito particulares. Aqui apresentamos a derivação das ditas equivalências para uma situação geral. Incluímos também as ferramentas matemáticas necessárias para o tratamento rigoroso do nosso problema / Abstract: In this work we give a rigorous proof of the equivalence of some different forms of Faraday's law of induction clarifying some misconceptions on the subject and emphasizing that many derivations of this law appearing in textbooks and papers are only valid under very special circunstances and not satisfactory under a mathematical point of view. We include also the mathematical apparatus necessary for a rigorous presentation of our subject / Mestrado / Fisica-Matematica / Mestre em Matemática Universitária

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-04T14:42:53Z No. of bitstreams: 1 marcelofonsecapinto.pdf: 1588144 bytes, checksum: 28fc6ada8effb0b27407c267aa0c8a7b (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-09-04T15:54:39Z (GMT) No. of bitstreams: 1 marcelofonsecapinto.pdf: 1588144 bytes, checksum: 28fc6ada8effb0b27407c267aa0c8a7b (MD5) / Made available in DSpace on 2018-09-04T15:54:39Z (GMT). No. of bitstreams: 1 marcelofonsecapinto.pdf: 1588144 bytes, checksum: 28fc6ada8effb0b27407c267aa0c8a7b (MD5) Previous issue date: 2018-07-05 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação foi desenvolvida a partir de uma revisão histórica dos trabalhos de Michael Faraday (1791-1867) referentes à teoria da eletrólise e suas leis eletroquímicas. De maneira interligada, efetuamos uma análise da evolução dos conceitos da eletricidade nos séculos XVII e XVIII tais como, teorias elétricas e a concepção da garrafa de Leyden, os estudos sobre eletricidade estática e sua transmissão, a pilha voltaica e os fenômenos de decomposição da água. Faraday foi um experimentalista criterioso, observador e crítico. Podendo se amparar na grande estrutura oferecida pela Royal Institution of Great Britain em Londres no século XIX, dedicou grande parte de sua vida à ciência e sua consequente popularização através de suas famosas Lectures, possuindo um papel fundamental na divulgação da ciência no século XIX. Exercendo cargos de professor Fulleriano de Química desta instituição e professor de Química da Academia Militar Real de Woolwich, pôde praticar sua metodologia de ensino. Suas pesquisas foram compiladas em diversas obras, mas nos dedicamos a analisar principalmente quatro destas, a saber: Faraday’s Diary (Vols. 1 e 2), Experimental Researches in Chemistry and Physics e Experimental Researches in Electricity, enfatizando as séries III a VIII desta última. Optamos por ter essas obras como bibliografias principais, pois sendo obras autorais do pesquisado, caracterizam-se como fontes primárias de pesquisa em História da Ciência, além de possuírem um elevado nível de detalhe em seus textos, nos mostrando aspectos da vivência do cientista, além dos erros e acertos em seus trabalhos. Dessa forma, fomos capazes de vivenciar parte do caminho trilhado por Faraday na elucidação das leis eletroquímicas entre os anos de 1832-34, nos permitindo analisar seus aspectos teóricos e práticos. / This dissertation was developed from a historical review of the work of Michael Faraday (1791-1867) concerning the theory of electrolysis and its electrochemical laws. In an interconnected way, we analyze the evolution of electricity concepts in the seventeenth and eighteenth centuries, such as electric theories and the Leyden bottle design, studies on static electricity and its transmission, the voltaic cell and water decomposition phenomena. Faraday was a judgmental, observant and critical experimentalist. With the support of the great structure offered by the Royal Institution of Great Britain in London in the nineteenth century, he devoted much of his life to science and its consequent popularization through his famous Lectures, playing a key role in the spread of science in the nineteenth century. Having held positions of Fullerian Professor of Chemistry of this institution and professor of Chemistry of the Royal Military Academy of Woolwich, he was able to practice his teaching methodology. Their research has been compiled in several works, but we focus mainly on four of these, namely: Faraday's Diary (Vols 1 and 2), Experimental Researches in Chemistry and Physics and Experimental Researches in Electricity, emphasizing series III to VIII of the latter. We chose to have these works as main bibliographies, because being works of the researcher they are characterized as primary sources of research in the History of Science, besides having a high level of detail in their texts, showing us aspects of the scientist's experience, besides of errors and correctness in their work. In this way, we were able to experience part of the path taken by Faraday in the elucidation of electrochemical laws between the years 1832-34, allowing us to analyze its theoretical and practical aspects.

Made available in DSpace on 2016-04-28T14:16:29Z (GMT). No. of bitstreams: 1 HCS - Joao Batista Alves dos Reis.pdf: 4748552 bytes, checksum: b98b1c23a854d24150e6e670ba053214 (MD5) Previous issue date: 2006-11-01 / The present research aimed to show the construction of Michael Faraday s (1791- 1867) electromagnetic theory, from an architectural methodological perspective. Thus, the starting point were the supporting pillars: the notion of the unity of the forces of nature and the goal of improving the mind. Next, it was sought to identify the constitutive elements, the dialogue between which would result in a harmonious building: observation, experiment and mental images, which would lead to the studies on the relationship between electromagnetism and light. Finally, Faraday s activity in the divulgation of science was approached, which showed a coherence with his lifelong principles. The main source for analysis was Faraday s diary, Faraday s Diary: Being the Various Philosophical Notes of Experimental Investigation. Other sources included Experimental Researches in Electricity and personal letters / Nesta pesquisa procurou-se mostrar a construção da teoria eletromagnética de Faraday, guiada por um projeto arquitetônico metodológico. Para isso, partiu-se de seus pilares de sustentação: a idéia de unidade das forças da Natureza e a proposta de aperfeiçoamento da mente. Em seguida, procurou-se identificar a seleção dos elementos constituintes desse harmônico edifício construído pelo diálogo entre observações, experimentos e imagens mentais, o que conduziria aos estudos sobre as relações entre eletromagnetismo e luz. Por último, foram abordadas as atividades de Faraday na divulgação da ciência em sua época, verificando-se a coerência com os princípios seguidos em todo o curso de sua vida. Para isso foram analisados os escritos de Michael Faraday (1791-1867) em seu diário, intitulado Faraday s Diary: Being the Various Philosophical Notes of Experimental Investigation. Além disso, analisou-se o Experimental Researches in Electricity. Consultamos, ainda, trechos de sua correspondência, além de outras obras

Faraday modulation spectroscopy (FAMOS) is a technique for detection of paramagnetic molecules. By applying a magnetic field over a gaseous sample, the presence of paramagnetic species will rotate the polarization plane of light, addressing a transition in such a species. By placing a gas containing paramagnetic molecules between almost crossed polarizers and modulating the magnetic field, the intensity of the transmitted light will consequently be modulated. Since the rotation of the polarization plane of light is proportional to the concentration of species, this technique can be used for quantitative analysis of paramagnetic molecules. Since FAMOS is solely sensitive to paramagnetic molecules it is superior to many other types of laser-based detection techniques, drastically decreasing various types of noise, background signals, as well as signals from other molecules; e.g. flicker noise, etalon effects and signals from water and CO2 molecules. An experimental setup for detection of nitric oxide (NO) by FAMOS has been developed and optimized. This system is based on a quantum cascade laser emitting light at 5.331 μm, addressing the—for FAMOS—most sensitive transition in NO, Q3/2(3/2). Optimized parameters include a pressure of 60 mbar, a magnetic field of 190 G and a polarizer uncrossing angle of 0.75°. In its present configuration, this system has demonstrated a detection of NO down to 200 ppb for a detection rate of 10 measurements per second. It is very possible that the limit of detection is even lower than this number since this lowest acquirable concentration is limited by the specifications of the gas mixer. A standard deviation between subsequent measurements, of 15 s time separation, is calculated to 30 ppb. However, this is far from the expected ultimate detection limit of this system and this technique in general. One process that causes a weakening of the signal is outgassing. When measuring on an emptied system this phenomenon is greatly reduced and a standard deviation of measurements is then measured and calculated to 7.6 ppb. The detection limit is presumed to be in the very low ppb, or sub-ppb, regime and this limit should be obtainable by further optimization of the system. / Gasen kvävemonoxid är en restprodukt vid förbränning av fossila bränslen, men den återfinns också i människokroppen som en signalsubstans. I stora mängder är den giftig då den interagerar med cellandningen och påverkar arvsmassan. I kombination med syre övergår den sakta till gasen kvävedioxid som i sin tur övergår till salpetersyra. Detta innebär att det är viktigt att kunna detektera denna gas i miljöer där risk för spridning kan anses vara stor. Kvävemonoxid används inom sjukvården som inhalationsgas för tidigt födda barn. Den förekommer även i ökad koncentration i utandningsluft hos människor med astma, Alzheimers eller Parkinsons sjukdom. Därmed finns det också ett intresse av att kunna mäta denna noggrant inom sjukvården, för att ge rätt dosering av gasen samt för att enklare kunna ställa korrekta diagnoser. Att mäta koncentration av kvävemonoxid görs ofta på kemiska vägar. Då detta är tidskrävande finns det anledning att utveckla nya och snabbare sätt att detektera denna gas. En effektiv teknik för att mäta kvävemonoxid är Faraday-moduleringsspektroskopi, FAMOS. Denna teknik bygger på att man med ett magnetfält, genom den så kallade Faradayeffekten, utnyttjar somliga fysikaliska egenskaper hos just kvävemonoxid, för att vidare bestämma dess mängd. FAMOS möjliggör mätningar i realtid och har en låg minsta detektionsgräns i jämförelse med andra laserbaserade tekniker. Framtidsutsikterna för denna teknik är mycket goda och möjligheterna utökas allt eftersom optisk utrustning förbättras. Denna rapport ger grunderna för FAMOS och den jämförs speciellt med en mer konventionell laserbaserad spektroskopisk teknik, våglängdsmodulering. Avhandlingen beskriver dessutom konstruktionen av ett FAMOS-system som baseras kring en kvantkaskadlaser vilken verkar med infrarött ljus på den, för kvävemonoxid, optimala energiövergången.

Un moyen permettant d'identifier expérimentalement les phases du gaz d'électrons bidimensionnel de la bicouche de graphène en empilement bernal au remplissage $\nu = 3$ est recherché lorsque le biais électrique entre les couches est varié. À ce remplissage, si on se concentre aux basses énergies, il est possible de ne s'intéresser qu'aux deux niveaux de Landau composant le niveau $N=0$ qui sont de même spin et de même vallée, mais d'orbitale différente. Puisque la texture du pseudospin orbital de ce système change selon la phase, il est attendu que le couplage avec le champ électrique de la lumière devrait changer. La dispersion des modes collectifs de chaque phase est calculée dans l'approximation GRPA (generalized random-phase approximation) dans le domaine en biais où chacune domine respectivement. L'absorption optique pour des polarisations linéaires en direction x et en direction y ainsi que pour des polarisations circulaires gauche et droite est calculée. La rotation de Faraday et l'effet Kerr sont également calculés. Des différences entre les phases sont remarquées au niveaux de la fréquence des photons qui sont absorbés, de l'amplitude de l'absorption et de la rotation de la polarisation ainsi que la sensibilité à certains types de polarisation. L'effet des modes collectifs dans les phases considérées est cependant moindre que celui qui est prédit dans un calcul qui ne tient pas compte de l'interaction de Coulomb.

Para discutir os efeitos magneto-óticos nos calcogenetos de Eu desenvolvemos uma expressão geral para a polarizabilidade de um sistema onde as transições eletrônicas importantes sao de orbitais localizados (orbitais 4f) para estados itinerantes (estados de Wannier 5dt2g). Tratamos em detalhe os elementos de matriz do operador dipolo elétri co levando em conta que o orbital 4f é um estado de muitas partículas. Incluimos explicitamente (numa aproximação simples) nos estados intermediários o potencial coulombiano criado pela lacuna no estado localizado 4f. Apresentamos um cálculo numérico da constante de Verdet e do deslocamento de fase Voigt (fases paramagnética e ferromagnética), dicro! smo circular e linear (fase ferromagnética)para o EuSe. Nosso resultado para a constante de Verdet concorda razoavelmente bem com os resultados experimentais e permite-nos estimar o valor da integral radial (4f|r|5d)~4x10-9cm. / To discuss the magneto-optical effects in the Eu chalcogenides we derive a general expression for the polarizability of a system in which the important electronic transitions are from localized to itinerant orbitals. This expression is applied to a model system in which the electronic transitions take place from a 4f orbital to a 5dt2g Hannier orbital centered at the same cell. We treat in detail the matrix elements of the electric dipole operator taking into account the many-body character of the 4f shell. The Coulow) potential of the intermediate state localized hole is included explici tely vli thin a simple approximation. We present a numerical calculation of the frequency dependent, Verdet constant and Voigt phase shift (paramagnetic and ferromagnetic phases), circular and linear dichroism (ferromagnetic phase) for the EuSe. The fittin~ of the Verdet constant to the experimental results is fairly good and allmv us to estimate the value of the integral (4flrl5d)~4x10-9cm.

The thesis explores preparation and properties of bismuthiron garnet (BIG) films and the incorporation of BIG films intoone-dimensional magneto-optical photonic crystals (MOPCs). Films were prepared by pulsed laser deposition. Weinvestigated or measured crystallinity, morphology,film-substrate interface, cracks, roughness, composition,magnetic coercivity, refractive index and extinctioncoefficient, and magneto-optical Faraday rotation (FR) andellipticity. The investigations were partly performed onselected samples, and partly on two series of films ondifferent substrates and of different thicknesses. BIG filmswere successfully tested for the application of magneto-opticalvisualization. The effect of annealing in oxygen atmosphere wasalso investigated - very careful annealing can increase FR byup to 20%. A smaller number of the above mentionedinvestigations were carried out on yttrium iron garnet (YIG)films as well. Periodical BIG-YIG multilayers with up to 25 single layerswere designed and prepared with the purpose to enhance FR at aselected wavelength. A central BIG layer was introduced asdefect layer into the MOPC structure and generated resonancesin optical transmittance and FR at a chosen design wavelength.In a 17- layer structure, at the wavelength of 748 nm, FR wasincreased from -2.6 deg/µm to -6.3 deg/µmat a smallreduction in transmittance from 69% to 58% as compared to asingle-layer BIG film of equivalent thickness. In contrast tothick BIG films, the MOPCs did not crack. We were first toreport preparation of all-garnet MOPCs and second toexperimentally demonstrate the MOPC principle inmagneto-optical garnets.

Abstract In this paper, the optical properties of magnetic fluid thin films are studied. We present the experimental observation of optical linear birefringence and dichroism in magnetic fluid thin film induced by crossed magnetic field perpendicular to the direction of light propagation. According to our results, we ascertain that both the magnetic birefringence and dichroism are existed. Besides, we also find that the relations between magnetic field and magneto-optical effects changed with the applied magnetic field intensity.

<p>The thesis explores preparation and properties of bismuthiron garnet (BIG) films and the incorporation of BIG films intoone-dimensional magneto-optical photonic crystals (MOPCs).</p><p>Films were prepared by pulsed laser deposition. Weinvestigated or measured crystallinity, morphology,film-substrate interface, cracks, roughness, composition,magnetic coercivity, refractive index and extinctioncoefficient, and magneto-optical Faraday rotation (FR) andellipticity. The investigations were partly performed onselected samples, and partly on two series of films ondifferent substrates and of different thicknesses. BIG filmswere successfully tested for the application of magneto-opticalvisualization. The effect of annealing in oxygen atmosphere wasalso investigated - very careful annealing can increase FR byup to 20%. A smaller number of the above mentionedinvestigations were carried out on yttrium iron garnet (YIG)films as well.</p><p>Periodical BIG-YIG multilayers with up to 25 single layerswere designed and prepared with the purpose to enhance FR at aselected wavelength. A central BIG layer was introduced asdefect layer into the MOPC structure and generated resonancesin optical transmittance and FR at a chosen design wavelength.In a 17- layer structure, at the wavelength of 748 nm, FR wasincreased from -2.6 deg/µm to -6.3 deg/µmat a smallreduction in transmittance from 69% to 58% as compared to asingle-layer BIG film of equivalent thickness. In contrast tothick BIG films, the MOPCs did not crack. We were first toreport preparation of all-garnet MOPCs and second toexperimentally demonstrate the MOPC principle inmagneto-optical garnets.</p>

Thèse de doctorat : Lasers, molécules et rayonnement atmosphérique : Lille 1 : 2001. / Résumé en français et en anglais. Bibliogr. p. 203-216.