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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo das propriedades supercondutoras em multicamadas de Nb, Pb, e Sn

SANTOS, Flávia Portela 26 March 2015 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-07-12T19:37:30Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_FlaviaPortela_2015.pdf: 24722134 bytes, checksum: ecaec07cae254145230ae32ad7de71e3 (MD5) / Made available in DSpace on 2016-07-12T19:37:30Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_FlaviaPortela_2015.pdf: 24722134 bytes, checksum: ecaec07cae254145230ae32ad7de71e3 (MD5) Previous issue date: 2015-03-26 / CAPES / O estudo em sistemas de multicamadas supercondutoras alcan cou grande interesse na pesquisa de novos materiais, pois al em de apresentarem ampla aplicabilidade tecnol ogica, oferecem fascinantes possibilidades de observar novos fen^omenos na supercondutividade. Esta ultima caracter stica e a de maior motiva c~ao para esta tese, uma vez que pouco ainda se tem reportado a respeito da supercondutividade em multicamadas constitu das por supercondutor(S)/supercondutor(S0). Neste trabalho, estudamos tr^es novos sistemas nanoestruturados formados por supercondutores elementares, de baixa temperatura cr tica, tais como ni obio (Nb), chumbo (Pb) e estanho (Sn), a saber, a tricamada Nb(5)/Pb(500)/Nb(50) e as multicamadas Nb(100)/[Sn(50)/Nb(50)]7 e Cr(10)/Nb(100)/[Sn(50)/Nb(50)]7, onde o termo entre par^enteses indica a espessura da referida camada em nan^ometros e os colchetes indicam que a estrutura Nb/Sn e repetida 7 vezes. Para compara c~ao, tamb em s~ao analisados lmes de refer^encia de Nb, Pb e Sn. Os lmes e as multicamadas foram crescidos a temperatura ambiente por deposi c~ao via sputtering, utilizando fontes DC e RF. As amostras foram caracterizadas por difra c~ao de raios X de baixo ^angulo, microscopia eletr^onica de varredura e por microscopia de for ca at^omica. As propriedades supercondutoras foram estudadas atrav es de medidas magn eticas e de transporte el etrico. Magnetiza c~ao e resistividade foram medidas como fun c~oes da temperatura e do campo magn etico aplicado perpendicular e paralelamente as camadas. Os tr^es sistemas apresentaram transi c~oes supercondutoras abruptas, tanto na magnetiza c~ao quanto na resistividade em fun c~ao da temperatura, com os valores de TC obtidos de 7,2 K para o Nb/Pb/Nb, 5,2 K para o Nb/[Sn/Nb]7 e 3,7 K para o Cr/Nb/[Sn/Nb]7. As propriedades supercondutoras dos lmes de Pb, Nb e Sn, tais como TC, 0Hc2 e comprimentos caracter sticos apresentaram coer^encia com os valores reportados na literatura, con rmando a boa qualidade das camadas. Flux jumps s~ao observados nos loops de histerese em todos os sistemas, os quais s~ao atribu dos a instabilidades termomagn eticas. A amostra Nb/Pb/Nb apresentou uma curvatura positiva na depend^encia de 0Hc2(T), indicando que a supercondutividade ocorre preferencialmente na camada de Pb para T > T e preferencialmente na camada de Nb para T < T , de acordo com a teoria de Takahashi-Tachiki. Os comprimentos caracter sticos s~ao calculados, classi cando as multicamadas como supercondutores do tipo II. Veri camos grande in u^encia do material magn etico Cr na supercondutividade da multicamada, causando a diminui c~ao da temperatura cr tica do sistema e modi cando o comportamento dos campos cr ticos inferior e superior. A depend^encia de 0Hc1(T), em todos os sistemas, revelou um comportamento n~ao convencional, que e atribu do a uma manifesta c~ao de sistemas multicomponentes com componentes espacialmente separadas. / The study of superconducting multilayers systems has achieved much interest in the research of new materials. Besides their wide technological applicability, these structures o er fascinating possibilities to observe new phenomena in superconductivity. The latter characteristic is the fundamental motivation for this thesis, since a little has been reported about multilayers constituted of superconductor(S)/superconductor(S0). In this work, we have studied three new nanostructured systems formed by low critical temperature conventional superconductors, such as niobium (Nb), lead (Pb) and tin (Sn): the trilayer Nb(5)/Pb(500)/Nb(50) and the multilayers Nb(100)/[Sn(50)/Nb(50)]7 and Cr(10)/Nb(100)/[Sn(50)/Nb(50)]7. The term in parenthesis indicates the thickness of the layer in nanometers and the brackets that Nb/Sn structure is repeated 7 times. For comparison, the reference lms of Nb, Pb and Sn were also analyzed. The thin lms and multilayers were growth at room temperature via sputtering deposition, by using DC and RF sources. The samples were characterized for small angle X ray di raction, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The superconducting properties were investigated through magnetic and electric transport measurements. The magnetization and resistivity were obtained as functions of temperature and magnetic eld applied both perpendicularly and parallel to the layers. All the multilayers systems have showed sharp superconducting transitions in the dependence of magnetization and resistivity with the temperature. The multilayers critical temperatures were found to be 7.2 K for Nb/Pb/Nb, 5.2 K for Nb/[Sn/Nb]7 and 3.7 K for Cr/Nb/[Sn/Nb]7. The superconducting properties of reference lms Pb, Nb and Sn, such as critical temperature, upper critical eld and characteristic lengths were consistent with the literature values, con rming the good quality of the samples. In the three systems ux jumps were observed, which are attributed to thermomagnetic instabilities. The Ginzburg-Landau parameter is estimated, classifying the multilayers as type II superconductors. In the case of Nb/Pb/Nb sample, it presented an upward curvature in the 0Hc2(T) diagrams, which is a signature of superconductivity nucleation in the each layer, in accordance with Takahashi-Tachiki theory for multilayered systems. We found out a noticeable in uence of the magnetic material Cr on the multilayer superconducting properties, reducing the critical temperature of the system and modifying the lower and upper critical elds behavior. The dependence of 0Hc1(T), of all the multilayers, revealed a non-conventional behavior feature, which is consistent with a multicomponent behavior with spatially separated components.
2

Fatigue d'un alliage d'aluminium moulé A357-T6 : rôle de la morphologie, de la position des défauts et application à une structure pour le calcul de la durée de vie en fatigue / High Cycle Fatigue of A357-T6 Cast Aluminium Alloy : Role of the Defect Morphology, Position and, Fatigue Life Assesment of a Structural Component

Rotella, Antonio 05 October 2017 (has links)
Ces travaux de thèse concernent la caractérisation en fatigue à grand nombre de cycles de l’alliage d’aluminium moulé A357-T6 (AS7G06-T6) en présence de défauts de type retassure. Six coulées ont été produites pour étudier deux familles de défauts : les retassures de type cavité et les retassures de type spongieuse avec un grade de nocivité qui varie entre 2 et 4 (selon la norme ASTM E 2422). La limite de fatigue en traction positive (R = 0.1) a été estimée en fonction de chaque type de défaut pour N = 2∙106 cycles. Des essais ont été également menés sur des éprouvettes dégradées en surface avec un défaut artificiel. Le défaut artificiel est caractérisé par une variation très localisée de la morphologie (usinage au FIB et par EDM) représentative de la microporosité interdendritique. La morphologie locale et globale des défauts naturels est étudiée grâce à des simulations numériques aux éléments finis. Les calculs numériques sont conduits sur la géométrie réelle d’un pore reconstruite à partir d’un scan en μ-CT. Deux géométries équivalentes ont été proposées pour approximer la morphologie d’un défaut naturel : une sphère et un ellipsoïde équivalent d’inertie.L’effet de la position du défaut sur l’évolution des champs mécaniques a été également étudié en conduisant des simulations numériques aux éléments finis sur la géométrie réelle du pore. Deux approches ont été proposés pour simuler un diagramme de type Kitagawa-Takahashi: (i) la Mécanique de la Rupture en Élasticité Linéaire (LEFM) (ii) un critère de fatigue detype Defect Stress Gradient (DSG), les deux modèles ont été testés dans le cas d’un amorçage sur un défaut de surface et interne.Une campagne d’essais de fatigue (R = 0.1) a été conduite à l’échelle d’un composant industriel. Une pièce réalisée par fonderie en A357-T6 a été testée dans une configuration saine et dégradée avec des défauts artificiels de surface. Un critère de type DSG, qui prend en compte l’effet du gradient de contrainte à l’échelle macroscopique de la structure, a été proposé.Le modèle a été validé par un calcul aux éléments finis du composant en utilisant une routine de post traitement des données, qui affiche en sortie la cartographie de la taille admissible du défaut de surface en chaque point du modèle simulé. / The purpose of this work is to characterize the high cycle fatigue strength of the A357-T6 (AS7G06-T6) cast aluminum alloy affected by natural casting defects (shrinkages). Six different castings have been manufactured in order to study two shrinkage types: the cavity shrinkages and the sponge shrinkages with a defect grade ranging from 2 to 4 (as defined by the ASTM E2422 standard). High cycle fatigue tests have been carried out in order to estimate the fatigue limit under positive tensile loading (R = 0.1) for each defect type at N = 2∙106 cycles. The effect of the local defect morphology has been investigated performing several fatigue tests on specimens with artificial surface defects characterized by a local morphology modification (FIB and EDM machining). The artificial defect size and morphology is representative of the natural interdendritic porosity. The local and global defect morphology of the natural defects have been studied by means of finite element simulations conducted on the real shrinkage morphology reconstructed from a μ-CT scan. Two equivalent geometries have been proposed to simplify the natural defect morphology: a sphere and an inertia - equivalent ellipsoid.The effect of the defect position on the mechanical filed evolution has also been studied by means of finite element simulations performed on the real defect geometry. The analysis of the Kitagawa-Takahashi diagram has been performedby using two different approaches for both internal and surface defects: (i) the Linear Elastic Fracture Mechanics (LEFM)(ii) the Defect Stress Gradient (DSG) fatigue criterion. An experimental campaign has been performed at a component scale. A casted A357-T6structural component has been tested with two different configurations: as received and degraded with artificial surface defects. A DSG fatigue criterion,taking into account the effect of the stress gradient at the macroscopic scale of the component, has been proposed. The model has been validated by means of finite element simulations using a data post-processing sub-routine that gives as output the critical defect size map at each point of the simulated model.
3

Effet des défauts d’usinage sur la tenue en fatigue de pièces aéronautiques. / Effect of machining defects on the fatigue strength of aircraft parts.

Abroug, Foued 23 April 2018 (has links)
Il été prouvée dans plusieurs études de la littérature que la taille d'un composant affecte sa tenue en fatigue et cette tendance est plus prononcée dans le régime de fatigue à grand nombre de cycles. Plus précisément, une baisse de la limite de fatigue est observée et est souvent expliquée par l’augmentation, avec l’augmentation du volume sollicité, de la probabilité de trouver un défaut critique ou une zone plus faible dans le matériau. Le présent mémoire fait partie d'un projet de recherche français (QUAUSI) regroupant plusieurs partenaires industriels et académiques qui vise à contrôler la qualité d'usinage des composants structuraux d'avions. Un des défis consiste à définir un critère approprié d'acceptabilité de défauts pour la conception en FGNC. Le critère doit être capable de prendre en compte une large gamme de défauts de surface et de composants de tailles et de géométries différentes. L'objectif principal étant de mieux comprendre l'impact des états de surface périodiques (caractéristique du type d'usinage utilisé) sur la limite de fatigue, Il a fallu d'abord vérifier si un effet de taille peut être observé quand un nombre croissant de défauts de surface simples sont introduits à la surface d'échantillons polis. Le matériau d’étude est l’alliage d'aluminium 7050 (Al Zn6CuMgZr). Une grande campagne d'essais de fatigue sous charge de flexion plane à R=-1 est effectuée sur des éprouvettes présentant des défauts hémisphériques, de différents tailles et nombres, et des états de surface usinés. Les résultats des essais ont permis de caractériser à la fois l'effet Kitagawa et l'effet d'échelle sur la tenue fatigue. Une approche probabiliste basée sur le concept du maillon le plus faible associé à un critère d'amorçage de fissure de fatigue approprié est utilisée pour prendre en compte la répartition des contraintes et la taille du volume fortement sollicité. Les prédictions utilisant des simulations EF montrent un bon accord avec les résultats expérimentaux et illustrent l'importance de prendre en compte l'effet d'échelle lors de la conception de composants contenant différents types de défauts de surface ou de motifs de rugosité.Mots-clés : Défaut de surface, fatigue à grand nombre de cycles, diagramme de Kitagawa-Takahashi, Le plus faible concept de lien, alliage AA7050 / The size of a component has been proved in several studies of the literature to affect the fatigue strength and this trend is known to be more pronounced in the High Cycle Fatigue regime. More exactly a drop of the fatigue limit is observed and this evolution is very often explained by the probability to find a critical defect or a weakest zone in the material as the stressed volume rises. The present manuscript is part of a French research project gathering several industrial and academic partners that aims to control the machining quality of aircraft structural components. For one part of the project the challenge is to define a proper defect acceptability criterion for HCF design purpose. It must be able to account for a large range of surface defects and of component sizes and geometries. Even though the primary objective was to better understand the impact of periodic surface micro-geometry patterns (characteristic of the type of machining used) on the fatigue limit, we thought that it was first necessary to check if a size effect can be observed when an increasing number of artificial simplified surface defects are introduced at the surface of smooth specimens. The aeronautical material under investigation is a 7050 Aluminum alloy (Al Zn6CuMgZr). A large fatigue testing campaign under fully reversed plane bending loading is undertaken on specimens with artificial surface hemispherical defects. Defect number varies from 1 to 44 per specimen whereas their size ranges from 60 µm to 800 µm. Testing results allow the characterization of both Kitagawa effect and scale effect on the fatigue response. A probabilistic approach based on the weakest link concept together with a proper fatigue crack initiation criterion is used to account for the stress distribution and the size of the highly stressed volume. Predictions using FE simulations show a good agreement with experimental results and illustrate the importance of taking the scale effect into account while designing components containing different types of surface defects or roughness patterns.Keywords : Surface defect, HCF, Kitagawa-Takahashi diagram, Weakest link concept, AA7050 alloy.
4

Symmetry-preserving contact interaction model for hadron structure and quark matter / Modelo de interação de contato que preserva simetrias para a estrutura hadrônica e matéria de quarks

Algarín, Fernando Enrique Serna [UNESP] 02 October 2017 (has links)
Submitted by FERNANDO ENRIQUE SERNA ALGARÍN null (ferse1129@gmail.com) on 2018-01-10T21:52:53Z No. of bitstreams: 1 tese.pdf: 948147 bytes, checksum: 94d535ccc424f5f4201747cae4382d6a (MD5) / Approved for entry into archive by Hellen Sayuri Sato null (hellen@ift.unesp.br) on 2018-01-12T15:54:08Z (GMT) No. of bitstreams: 1 algarin_fcs_dr_ift.pdf: 948147 bytes, checksum: 94d535ccc424f5f4201747cae4382d6a (MD5) / Made available in DSpace on 2018-01-12T15:54:08Z (GMT). No. of bitstreams: 1 algarin_fcs_dr_ift.pdf: 948147 bytes, checksum: 94d535ccc424f5f4201747cae4382d6a (MD5) Previous issue date: 2017-10-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nesta tese empregamos um modelo de interação de contato que preserva simetrias para estudar estrututura hadrônica e matéria de quarks. A interação de contato é uma representação de kernels não perturbativos usados em equações de Dyson-Schwinger e Bethe-Salpeter da Cromodinâmica Quântica (QCD). A ideia básica do modelo está baseada num esquema de subtração que evita passos tradicionais no cálculo de de integrais divergentes que invariavelmente levam a violações de simetrias. Em temperatura zero, as equações de Dyson-Schwinger equation para os propagadores dos quarks u; d; s and c são resolvidas e amplitudes de estado ligado de Bethe-Salpeter, que respeitam a invariância sob translações espaço-temporais e as identidades de Ward-Takahashi associadas com simetrias globais da QCD, são obtidas para calcular as massas e as constantes de decaimento eletrofracas dos mésons pseudoscalares π; K, D e Ds e dos mésons vetorias ρ, K*, D* e Ds*. As predições do modelo estão em bom acordo com dados experimentais e da QCD na rede. Em adição, estendemos o modelo para temperaturas diferentes de zero; neste caso, o problema de violação de simetrias está restrito apenas às partes puramente divergentes porque os termos que dependem das distribuições térmicas são finitas e não requerem regularização. Finalmente, investigamos a dependência com a temperatura das contribuições das flutuações quânticas quark-π e quark-σ aos coeficientes de transporte de viscosidade de cisalhamento η e volumétrica ζ e as suas razões com a densidade de entropia s. As larguras térmicas originárias dessas fluctuações são calculadas com o formalismo de teoria de campos a temperatura finita de tempo real. Para esse cálculo, empregamos os resultados obtidos com as equações de Dyson-Schwinger e Bethe-Salpeter para a dependência com a temperatura das massas dos mésons e as contantes de acoplamento quark-méson. Os resultados para as razões η/s and ζ/s estão em bom acordo com resultados com a literatura obtidos com modelos e técnicas diferentes. Em particular, nossos resultados para η/s possuem um mínimo muito próximo ao limite inferior da conjectura AdS/CFT, η/s = 1/4π. / In thesis, a symmetry-preserving contact interaction model is used to study hadron structure and quark matter. The contact interaction is a representation of nonperturbative kernels used in Dyson-Schwinger and Bethe-Salpeter equations of Quantum Chromodynamics (QCD). The basic idea of the model is based on a subtraction scheme that avoids standard steps in the evaluation of divergent integrals that invariably lead to symmetry violation. At zero temperature, the Dyson-Schwinger equation is solved for the u; d; s and c quark propagators and the boundstate Bethe-Salpeter amplitudes respecting spacetime-translation invariance and the Ward-Green-Takahashi identities associated with global symmetries of QCD are obtained to calculate masses and electroweak decay constants of the pseudoscalar π; K, D and Ds and vector ρ, K*, D*, and Ds* mesons. The predictions of the model are in good agreement with available experimental and lattice QCD data. In addition, we extend the model to nonzero temperature; here, the problem of symmetry violation is associated only with the purely divergent parts because the effects due to the termal distributions are finite and do not need regularization. We compute the temperature dependence of the masses and decay constants of the pseudoscalar mesons considered here. Finally, we have investigated the temperature dependence of the contributions of quark-π and quark-σ quantum fluctuations to the transport coefficients of shear η and bulk ζ viscosities and their ratios to the entropy density s. The quark thermal widths originating those fluctuations are calculated with the formalism of real-time thermal field theory. For these calculations, we have used the results obtained via Dyson-Schwinger and Bethe-Salpeter equations for the temperature dependence of constituent quark and meson masses and quark-meson couplings. The results for the ratios η/s and ζ/s are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η/s has a minimum very close to the conjectured AdS/CFT lower bound, η/s = 1/4π. / CNPq:140041/2014-1
5

<b>Depictions of Pregnancy, Children, Fertility, and Family Structure by Takahashi Takako, Ogawa Yōko, and Murata Sayaka in Modern Japanese Literature</b>

Bayan Konysbekkyzy (18387354) 17 April 2024 (has links)
<p dir="ltr">In this thesis, I examine three popular modern Japanese female writers—Takahashi Takako (1932-2013), Ogawa Yōko (1962- ), and Murata Sayaka (1979- ), who all debuted after the peak of Japan’s bubble economy in the late 1980s. Focusing on the works of these three authors, I investigate how they deal with the theme of pregnancy, children, fertility, and family structure, and how they are original in the world of Japanese literature. Since they are all women, in terms of feminist context, I also look into how differently they respond to gender issues from the prior generation of female authors.</p><p dir="ltr">In the Introduction, I begin with an examination of how Japanese society has changed fertility and family structure during the lifetime of women writers, which the author of this thesis aims to depict. Through an analysis of themes such as pregnancy, childbearing, fertility, and family dynamics, these authors offer nuanced reflections on the evolving roles and experiences of Japanese women within the context of a rapidly changing society. Despite their unique literary styles, they share a common interest in challenging traditional notions of womanhood and motherhood, often conflicting with societal pressures.</p><p dir="ltr">In Chapter One, the focus is on Takahashi Takako's narratives, which critique the conventional female trajectory in Japan and the societal pressures surrounding parenthood. In Chapter Two, the examination shifts to Ogawa Yōko's portrayal of female protagonists navigating societal expectations and rejecting traditional paths to womanhood and pregnancy. Finally, Chapter Three delves into Murata Sayaka's exploration of themes related to nonconformity, gender roles, marriage, and the evolving dynamics of Japanese society.</p><p dir="ltr">By analyzing these authors' works, this thesis contributes to a deeper understanding of Japanese women's experiences and societal dynamics, offering insights into contemporary issues of gender, identity, and autonomy in Japan.</p>
6

Zur kompositorischen Relevanz kultureller Differenz: Historische und ästhetische Perspektiven

Utz, Christian 23 June 2023 (has links)
Recent developments in today’s art music reflect a general trend of cultural globalisation: It can be characterised as an oscillation between a standardisation of compositional idioms (usually following standards established in the West) and claims for sustainable forms of cultural difference. Even though it is obviously necessary to counterbalance and criticise an academically established »avant garde’s« ethnocentrism and its tendency to dominate a worldwide discourse of new music, references to cultural difference can prove to be naïve or self-deceiving, since they are often linked to essentialist, post-nationalist concepts of (musical) culture. A critical discussion of paradigms and paradoxes in the aesthetics of cultural difference is opened with an analysis of Karlheinz Stockhausen’s universalist Telemusik (1966) as a main example showing how compositional processes can easily eradicate those »cultural« peculiarities in musical styles that the composer claims to preserve. Whereas such processes are often due to a fundamentally mono-cultural discourse and – in Stockhausen’s case – can be traced back to the 19th century Western universalist concept of »art religion«, the three remaining case studies introduce works from Asian contexts that exemplify a dense interpenetration of political, historical and aesthetical strata of both Asian and Western origins. While José Maceda’s Pagsamba (1968), Ge Ganru’s Yi Feng (1983) and Yuji Takahashi’s Sojo Rinzetsu (1997) all use highly idiosyncratic »Asian« material, their works remain informed by key principles of Western modernity, namely incommensurability and the deconstruction of cultural or stylistic stereotypes. This allows for the conclusion that the »space« in which their musical art evolves is a globalised cultural memory that reflects the inner contradictions and the historicity of music as a »cultural« technique.
7

El?trons fortemente correlacionados na vizinhan?a de uma transi??o de fase qu?ntica

Farias, Carlene Paula Silva de 18 October 2013 (has links)
Made available in DSpace on 2014-12-17T15:15:03Z (GMT). No. of bitstreams: 1 CarlenePSF_DISSERT.pdf: 1687677 bytes, checksum: 1148ebf1be9615049fa1952b3098a785 (MD5) Previous issue date: 2013-10-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The aim of this work is to derive theWard Identity for the low energy effective theory of a fermionic system in the presence of a hyperbolic Fermi surface coupled with a U(1) gauge field in 2+1 dimensions. These identities are important because they establish requirements for the theory to be gauge invariant. We will see that the identity associated Ward Identity (WI) of the model is not preserved at 1-loop order. This feature signalizes the presence of a quantum anomaly. In other words, a classical symmetry is broken dynamically by quantum fluctuations. Furthermore, we are considering that the system is close to a Quantum Phase Transitions and in vicinity of a Quantum Critical Point the fermionic excitations near the Fermi surface, decay through a Landau damping mechanism. All this ingredients need to be take explicitly to account and this leads us to calculate the vertex corrections as well as self energies effects, which in this way lead to one particle propagators which have a non-trivial frequency dependence / Nesse trabalho derivamos e checamos a Identidade de Ward (IW) para uma teoria efetiva de baixas energias de um sistema fermi?nico acoplado a um campo de gauge U(1), em 2+1 dimens?es, na presen?a de uma superf?cie de Fermi parab?lica. As identitades deWard s?o muito importantes pois, estabelecem requisitos para que a teoria efetiva seja invariante de gauge. Veremos que a IW n?o ? preservada em ordem de 1-loop. Isto caracteriza a presen?a de uma an?malia qu?ntica. Assim, uma simetria cl?ssica ? destruida dinamicamente por flutua??es qu?nticas. O nosso sistema f?sico se encontra na vizinhan?a de um Ponto Cr?tico Qu?ntico. Portanto, as excita??es fermi?nicas, que se situam pr?ximo a superf?cie de Fermi, decaem com o tempo, produzindo assim um amortecimento de Landau. Todos esses ingredientes de um regime de forte acoplamento devem ser levados em conta. E em fun??o disso calcularemos as corre??es de v?rtice e os efeitos das auto-energias, que dessa forma fazem com que os propagadores de uma part?cula da teoria dependam da frequ?ncia de uma forma n?o-trivial
8

Creating Ezo: The Role of Politics and Trade in the Mapping of Japan’s Northern Frontier

Dicken, Evan R. 11 September 2009 (has links)
No description available.
9

Documentary theatre: pedagogue and healer with their voices raised

Unknown Date (has links)
The beginning of the new millennium finds documentary theatre serving as teacher and “healer” to those suffering and in need. By providing a thought provoking awareness of the “other,” it offers a unique lens with which to examine the socio-political similarities and differences between various cultures and ethnicities in order to promote intercultural understanding. Documentary is also used by teachers, therapists, and researchers as a tool for healing. By sharing personal stories of trauma and illness with others who are experiencing similar difficulties, emotional pains are alleviated and fears are assuaged. Documentary theatre has expanded in definition from the “epic dramas” of German playwrights Erwin Piscator and Bertholt Brecht during the height of the German Weimar Republic to the recent “verbatim” scripts of playwrights such as Anna Deveare Smith, Emily Mann, and Robin Soans. The dramaturgical duties of the playwright along with the participatory role of the audience have grown in complexity. In verbatim documentary the playwright must straddle a fine line between educating and entertaining while remaining faithful to the words of the respondents as well as to the context in which they were received. The audience, by responding to questionnaires and by engaging in talk-back sessions, plays a pivotal role in production. Documentary serves as an important vehicle for informing and inspiring audiences from all walks of life. In 2010, researchers Dr. Patricia Liehr of the Christine E. Lynn School of Nursing at Florida Atlantic University and Dr. Ryutaro Takahashi, Vice Director of the Tokyo Metropolitan Institute of Gerontology, approached me to create a documentary based on their combined interviews of Pearl Harbor and Hiroshima survivors. The resultant script, With Their Voices Raised, is included as an appendix to this dissertation as an example of the documentary genre and its unique capacity for research dissemination. With Their Voices Raised not only conveys the memories and fears of the survivors, but in its conclusion reveals how these victims of war have elected to live their lives in a quest for peace- choosing “hope over hate” in a shared world / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

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