Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (p. 86-93).

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 72-77).

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 217-224).

Thesis (Ph.D.)--Baylor University, 2009. / Includes bibliographical references (p. 124-130).

Made available in DSpace on 2014-06-11T19:28:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-13Bitstream added on 2014-06-13T19:58:20Z : No. of bitstreams: 1 castilho_aa_me_sjc.pdf: 568029 bytes, checksum: 0b5b31953733da6dcf83b1d44aeb677d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo neste estudo foi avaliar a alteração dimensional provocada pelos procedimentos de soldagem nas infra-estruturas de próteses fixas impanto-suportadas por meio de análise de extensometria linear elétrica assim como se determinar a resistência flexão de dois tipos de juntas soldadas (Arco-Plasma e Laser) em liga Odontológica Co-Cr. Para tanto, estruturas metálicas foram fundidas pelo método de indução para pilares tipo micro-unit. Para esse estudo, foram investigados três grupos: Grupo controle (G I: fundição em Monobloco, n=10), Grupo Arco-Plasma (G II: fundição segmentada e soldagem da estrutura em Arco-Plasma, n=10) e Grupo Laser (G III: fundição segmentada e soldagem da estrutura em LASER, n=10) as quais após assentamento em modelo de análise extensométrica, foram coletadas três leituras de microdeformação (με) para cada amostra. Os grupos, após ensaio de extensometria linear elétrica, foram submetidos ao teste de resistência à flexão (MPa) em máquina de ensaios universal (EMIC, 0,5 mm/min, 500Kg). As médias ±DP dos valores de microdeformação observados para as condições foram para o grupo Monobloco:461,9με; para o grupo Arco-Plasma: 637,0με e para o grupo Laser : 526,8με. Os resultados obtidos após o teste de resistência à flexão foram: para o grupo Monobloco: 1857,2MPa; para o grupo Arco-Plasma: 1820MPa e para o grupo Laser : 1068Mpa. Uma comparação em análise extensométrica entre os três grupos, quanto à distribuição dos valores de alteração dimensional, foi efetuada por meio do teste de Kruskal-Wallis. Verificou-se que a distribuição dos valores de alteração dimensional não difere Estatisticamente (estatística kw = 1,77; gl = 2; p = 0,414 > 0,05). Uma comparação entre os três grupos, quanto à distribuição dos valores... / The aim of this study was to evaluate the dimensional changes caused by the welding procedures in implant-supported prostheses infrastructure by strain gauge analysis as well as to determine the flexural strength values of two types of welded joints (Arc-Plasm and Laser) in Co-Cr dental alloy. Thus, metal structures were casted by induction method for micro-unit type abutment. For this study, three groups were evaluated: Control Group (G I: monoblock casting, n = 10), Arc-Plasm Group (G II: casting and welding of structures in Arc-Plasm, n = 10) and Laser Group (G III: casting and welding of structures in Laser, n = 10), in which were, after placing the samples in the strain gauge analysis model, three micro strain (με) measurements for each specimen were collected. The groups, after strain gauge analysis, were submitted to flexural strength (MPa) test in an universal testing machine (EMIC, 0.5 mm / min, 500Kg). Mean ± SD values of microstrain conditions observed for the Monoblock group were: 461.9 mε; for the Arc-Plasm group: 637.0 mε and the Laser group: 526.8 mε. The results, after flexural strength test, were: Monoblock group: 1857.2 MPa; Arc-Plasm group: 1820 MPa and Laser group: 1068 MPa. The strain gauge comparison analysis between the three groups, as well the distribution of dimensional changes values were made by Kruskal- Wallis test. It was found that the values´ distribution of dimensional changes do not differ statistically (KW statistic = 1.77, df = 2, p = 0.414> 0.05). A comparison between the three groups, in relation to the 108 distribution of the values of flexural strength, was performed by Kruskal- Wallis test. It was found that the values distribution of flexural strength differ statistically... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:28:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-03Bitstream added on 2014-06-13T18:58:12Z : No. of bitstreams: 1 abreu_cw_me_sjc.pdf: 508442 bytes, checksum: 720d525ea366cc2fd0575e67a37ba04e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo desse estudo foi avaliar a aplicação de carga e distribuição das microdeformações ao redor de implantes com conexão protética cone morse. Três implantes foram inseridos num bloco de poliuretano e pilares microunit foram instalados nos implantes com torque de 20 Ncm. Três coifas usinadas foram adaptadas nos pilares para configurar a supraestrutura protética (n=5) e comparar com as supra-estruturas obtidas com coifas plásticas. Quatro extensômetros foram colados na superfície superior do bloco. Uma carga vertical estática de 30 Kg foi aplicada em cinco pontos das supra-estruturas. Os registros obtidos dos extensômetros foram submetidos ao teste estatístico ANOVA e Tukey (α=5%). As medidas derivadas dessa simulação revelaram que durante a aplicação de carga: (1) existiu uma relação direta do local de aplicação e na distribuição da microdeformação ao redor dos implantes; (2) não existiu diferença na microdeformação entre coifas plásticas e usinadas. / The aim of this study was to evaluate the load transfer and strain distribution by an implant-supported fixed partial prosthesis. Three implants Morse Taper were inserted in a polyurethane block and abutments microunit were installed on the implants with a torque of 20 Ncm. Plastic cylinders and prefabricated cylinders were adapted on abutments to fabricate the framework (n=5). Four strain gauges were attached on the superior surface of the block and then each framework was tight on the abutments with a torque of 10 Ncm and vertical load of 30Kg was applied to five points on the framework. The data obtained in the strain gauge analysis were submitted to the statistical tests ANOVA and Tukey (α=5%). The measurements derived from this simulation revealed that: (1) there was a direct proportion between the strain distribution in the metal framework and stresses created in the supporting structure around the implants; (2) there was not a strain difference between plastic and prefabricated cylinders during the load transfer

This thesis investigates applications of the gauge/gravity duality to strongly coupled quantum field theories. After a review of the duality and of correlators and transport in quantum systems, we present our results on second-order non-conformal hydrodynamics. We derive new Kubo formulae for five second-order transport coefficients in non-conformal relativistic fluids. We then apply these Kubo formulae to a class of non-conformal holographic fluids at infinite coupling. We find strong evidence that the Haack-Yarom identity, known to relate second-order coefficients in conformal holographic fluids at infinite coupling, continues to hold in holographic fluids without conformal symmetry: Within our class of models, we prove that it still holds when leading non-conformal corrections are taken into account, and we show numerically that it is also obeyed beyond leading order. This provides further evidence that the identity may be a universal feature of strongly coupled fluids. Next, we present our results on magnetic spin impurities in strongly correlated systems. We build a holographic two-impurity Kondo model, identifying the inter-impurity interaction as double-trace deformation. Our numerical results for the phase diagram suggest a quantum phase transition between a trivial phase with uncorrelated spins and no Kondo screening, and a non-trivial phase with anti-ferromagnetic correlations and simultaneous Kondo screening. Computing the spectrum in the single-impurity case, we observe Fano resonances, which at low temperatures we identify with the Kondo resonance.

In this thesis we study gauge/gravity duals in the 5d/6d AdS/CFT correspondence. We start with field theories defined on squashed five-spheres with SU(3) × U(1) symmetry. These five-sphere backgrounds are continuously connected to the round sphere. We find a one-parameter family of 3/4 BPS deformations and a two-parameter family of (generically) 1/4 BPS deformations. The gravity duals are constructed in Euclidean Romans F(4) gauged supergravity in six dimensions, and uplift to massive type IIA supergravity. We holographically renormalize the Romans theory, and use our general result to compute the renormalized on-shell actions for the solutions. The results agree perfectly with the large N limit of the dual gauge theory partition function, which we compute using large N matrix model techniques. In addition we compute BPS Wilson loops in these backgrounds, both in supergravity and in the large N matrix model, again finding precise agreement. We conjecture a general formula for the partition function on any five-sphere background, which for fixed gauge theory depends only on a certain supersymmetric Killing vector. We then proceed to study Euclidean Romans supergravity in six dimensions with a non-trivial Abelian R-symmetry gauge field. We show that supersymmetric solutions are in one-to-one correspondence with solutions to a set of differential constraints on an SU(2) structure. As an application of our results we (i) show that this structure reduces at a conformal boundary to the five-dimensional rigid supersymmetric geometry previously studied, (ii) find a general expression for the holographic dual of the VEV of a BPS Wilson loop, matching an exact field theory computation, (iii) construct holographic duals to squashed Sasaki-Einstein backgrounds, again matching to a field theory computation, and (iv) find new analytic solutions to the squashed five-sphere background. We also analyse the classification of gravity duals with zero B-field.

In this thesis we study the connection between conformal symmetry breaking and the the renormalization group. In the first chapter we review the main properties of conformal field theories (CFTs), Wilsonian RG and describe how renormalization induces a flow between different CFTs. The prominent role is given to the trace of energy-momentum tensor (TEMT) as a measure for conformal symmetry violation. Scaling properties of supersymmetric gauge theories are also reviewed . In the second chapter the quantum action principle is introduced as a scheme for renormalizing composite operators. The framework is then applied to derive conditions for UV finiteness of two-point correlators of composite operators with special emphasis on TEMT. We then proceed to discuss the application of the Feynman-Hellmann theorem to evaluate gluon condensates. In the third chapter the basic elements the Trace anomaly on curved space are examined. The finiteness results from Chapter 2 are given physical meaning in relation with the RG flow of the geometrical quantity ~ d (coefficient of □R in the anomaly). The last chapter is dedicated to the a-theorem. First we apply some of the results derived in Chapter 3 to extend the known perturbative calculation for the flow of the central charge βa for gauge theories with Banks-Zaks fixed point. In the last part we review the main ideas of the recent proof of the a-theorem by Komargodski and Schwimmer and apply their formalism to re-derive the known non-perturbative formula for ∆ βa of SUSY conformal window theories.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo desta dissertação é apresentar uma conexão entre a condição de Gribov-Zwanziger para o gap de massa e o mecanismo de quebra espontânea de simetria, através do estudo de um operador composto introduzido numa maneira localizada. Para tornar esta relação mais clara, um modelo é apresentado e alguns aspectos quânticos são discutidos. / The aim of this work is to present a connection between the Gribov-Zwanziger condition for the mass gap and the spontaneous symmetry breaking mechanism, by studying a composite operator introduced in a localized form. In order to clarify these relationship a toy model is presented and some quantum aspects are discussed.