Made available in DSpace on 2014-10-09T12:52:30Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:35Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:52:30Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:35Z (GMT). No. of bitstreams: 0 / Biomateriais metálicos devem apresentar uma combinação de propriedades como resistência à corrosão, biocompatibilidade e resistência mecânica. Os aços inoxidáveis austeníticos, especialmente do tipo AISI 316L, aliam estas propriedades com a possibilidade de fabricação a um baixo custo. No entanto, são susceptíveis à corrosão nos fluidos fisiológicos e seus produtos de corrosão podem causar reações alérgicas ou infecciosas nos tecidos vizinhos ao implante. No presente trabalho, a aplicação de revestimentos obtidos por processos de deposição física de vapor (PVD) sobre um aço inoxidável austenítico do tipo AISI 316L foi realizada a fim de aumentar sua resistência à corrosão e biocompatibilidade. Os filmes depositados foram de nitreto de titânio (TiN), carbonitreto de titânio (TiCN) e de carbono tipo diamante (DLC). Estes materiais têm alta dureza e resistência ao desgaste, além de biocompatibilidade intrínseca, características altamente desejáveis para aplicações biomédicas. A caracterização do comportamento eletroquímico do aço com os três tipos de revestimentos mostrou que a presença de defeitos na superfície das camadas depositadas exerce uma influência negativa sobre a resistência à corrosão do substrato. A presença dos defeitos foi evidenciada por microscopia eletrônica de varredura. Foi proposto um mecanismo, com base nos dados obtidos por espectroscopia de impedância eletroquímica, para explicar a evolução do comportamento eletroquímico do aço com os diferentes revestimentos ao longo do tempo de imersão. Foram também empregados dois tratamentos de passivação da superfície do aço em soluções de ácido sulfúrico e ácido nítrico, a fim de aumentar a resistência à corrosão do substrato. Os resultados indicaram que os tratamentos utilizados não foram eficientes para melhorar esta característica, mas podem ser modificados visando um desempenho superior. As propriedades eletrônicas dos filmes passivos formados, tanto sobre o aço sem tratamento de passivação como sobre o aço passivado, foram estudadas utilizando a abordagem de Mott-Schottky. Os filmes apresentaram um caráter duplex, mostrando comportamento de um semicondutor altamente dopado acima e abaixo do potencial de banda plana. A concentração de dopantes no filme passivo foi associada à resistência à corrosão do material. Os três revestimentos PVD investigados apresentaram comportamento não citotóxico. Considerando a diminuição do coeficiente de atrito do aço 316L, os revestimentos de TiCN e o DLC foram os mais eficientes. Estas características, aliadas ao fator custo, sugerem que a aplicação comercial destes materiais sobre implantes ortopédicos pode ser viável. No entanto, a resistência à corrosão, conforme a avaliação realizada no presente estudo, não foi adequada quando comparada ao desempenho do aço sem nenhum tipo de revestimento. Ao final do texto, são apresentadas algumas sugestões a fim de conseguir um desempenho superior para a capacidade protetora dos revestimentos PVD. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

The thesis deals with the portrayal and function of space in literary and film versions of the 60's wave texts - the Cremator and Diamonds of the Night. The first chapter is concerned with works of autors, who focused between 1945 - 1968 on the second World war literature. Then the thesis tries to describe shortly the issue of portrayal of space in the literature and film adaptations. The folowing chapters focuse directly on the comparison of space in the two selected works. The aim of this thesis is to find out and to describe differences between portrayal of the spaces via literary and film instruments. Key words Ladislav Fuks, the Cremator, Arnošt Lustig, Diamonds of the Night, Darkness Casts No Shadow, 1space, adaptation, 1960s, film.

Cette thèse est consacrée à l'étude théorique des propriétés de transportd'un nanodispositif comme par exemple une boîte quantique. A faible dimensionnalité,les propriétés de transport sont fortement liées à la densité d'étatsélectroniques du système, il est donc important d'utiliser une approche capablede calculer cette dernière correctement notamment en tenant comptedu confinement électronique.En utilisant le modèle d'Anderson et l'approximation de non croisementafin de calculer la densité d'états, on a pu observer et caractériser les transfertsde poids spectral pour des orbitales simplement, doublement ou triplementdégénérées. Ces transferts de poids spectral sont typiques des systèmescorrélés, mais lorsqu'une différence de potentiel est appliquée, on a pu remarquerque ces transferts se faisaient en deux temps.Dans un second temps, on a analysé les signatures du couplage de Hundincluant le terme de saut de paires dans les diagrammes de stabilité. Ces deuxtermes, provenant de l'interaction Coulombienne, modifient sensiblement lastructure des diamants de Coulomb et doivent donc être considérés lorsqu'ondéduit les paramètres microscopiques à partir du diagramme de stabilitéexpérimental.Enfin, on s'est placé dans le régime de générateur thermoélectrique, et ona utilisé le pic de Kondo comme canal de transport. Cependant l'optimisationà la fois du rendement et de la puissance en utilisant les bandes de Hubbardcomme canaux de transport est impossible. Or les particularités et les grandeurscaractérisant le pic de Kondo permettent d'une part de s'affranchirpartiellement de ce compromis mais cela permet également de générer uneplus grande puissance. / This thesis is devoted to the theoretical study of a nanodevice transportproperties, such as a quantum dot. At low dimensionality, transport propertiesare strongly related to the local density of state, it is important to use anapproach able to compute the latter properly especially tanking into accountthe electronic containment.Using the Anderson model and the non-crossing approximation to computedensity of states, we observed and characterize spectral weight transfersfor simply, doubly and triply degenerated orbitals. These spectral weighttransfers are typical of correlated systems, but when potential bias is applied,we note that these transfers occur in two stages.In a second step, we analyze Hund coupling footprint including pair hoppingin stability diagrams. These two terms, from the Coulomb interaction,substantially alter the Coulomb diamonds structure and must be considerwhen microscopic parameters are derived from experimental stability diagrams.Finally, we placed in the thermoelectric generator regime, and we usedKondo peak as transport channel. However, optimization of both efficiencyand power output using Hubbard bands as transport channel is impossible.But the features and scales characterizing Kondo peak serve on the one handto overcome this compromise and on the other hand to generate a greaterpower output.

Department of Sociology / MA (Industrial Sociology)

The main result of the thesis is the derivation of quantum phenomenological gravi- tational dynamics from the thermodynamics of local causal diamonds. By taking into account logarithmic corrections to entropy implied by quantum gravity effects, we derive new gravitational equations of motion which incorporate quantum corrections. The re- sulting theory appears to be a direct generalisation of the classical unimodular gravity instead of the general relativity. Upon obtaining the equations, we discuss their prop- erties and possible implications. As by-products, we also present a novel derivation of the Einstein equations from the thermodynamics of causal diamonds and a derivation of the logarithmic corrections to black hole entropy from the existence of minimal re- solvable area. Apart from the new results, we also provide an extensive review of the thermodynamics of local causal horizons. 1

The United States jewelry industry recognized that the illegal import and trade of conflict diamonds is a matter of serious international and national concern, leading to human rights abuse. As such, human rights and conflicts became the primary impetus for establishing the Kimberly Process (KP) and corporate social responsibility (CSR) policies. The purpose of this quantitative study was to investigate the effectiveness of the KP and CSR policies in deterring the use of conflict diamonds in the U.S. jewelry industry. This study was an investigation as to whether conflict diamonds are entering the U.S. jewelry supply chain and a review of the ethics of the U.S. jewelry industry in light of the conflict diamond issue. Conflict theory provided the theoretical framework used to gather data on conflict diamond protocols and on corporate social responsibilities within the U.S. jewelry industry. The sample was composed of 59 randomly selected participants from the U.S. jewelry industry whose opinions were indicative of that industry. Data were analyzed descriptively and inferentially. Multiple statistical tests were used for the data analysis that included regression and the Mann-Whitney U test. The overall results indicated that the KP and the CSR policies were insignificant in deterring the use of conflict diamonds in the U.S. jewelry industry; therefore, the null hypothesis was retained. This study contributed to a better understanding of the ethical dimensions of conflict diamonds and the committed management practices of the U.S. jewelry industry. Positive social change can be realized when respect for fundamental human rights is achieved by the global diamond industry and becomes a requisite foundation for every society to bring an end to the flow of conflict diamonds.

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This study is presented in nine chapters as follows: Chapter one reviews the reported literature on the NMR of natural diamond. The NMR signal of diamond consists on a single line at 39 ppm from TMS and two hyperfine lines due to 13C interactions. The reported relaxation times, measured in natural diamond, synthetic diamonds and 13C enriched diamonds, are discussed. The second chapter introduces the apparatus used, which included a Bruker Avance NMR spectrometer, a Bruker ESP380E pulsed EPR spectrometer and a high powersband DNP system. The availability of this excellently equiped laboratory presented a unique opportunity to perform this investigation. Chapter three outlines the experimental techniques used as well as the manner in which the acquired data was processed. The fourth chapter presents an overview of the most common defects found in diamond. Proposed models of these defects are presented and the resulting EPR spectra displayed. The methods developed to determine the paramagnetic impurity concentration from the EPR line width and the spin-spin relaxation times are presented in the fifth chapter. The line width gives the total paramagnetic impurity concentration to about 10 ppm. The spin-spin relaxation time allows the determination of Pl and P2 paramagnetic impurity concentrations individually, to much lower levels from measurements on the central and hyperfine lines. This information was used in the explanation of the relaxation behaviour for the various diamonds investigated. The temperature dependence of the paramagnetic electron relaxation times is reported in the sixth chapter. The results obtained are consistent with the findings in prior work that Pl impurities are typical Jahn Teller centres. Two diamonds, however, display trends that depart from this theory. These diamonds contain N3 defect centres, which appear to be responsible for this behaviour. It was found in these experiments that, bar thermal expansion effects, the spin-spin relaxation time is essentially independent of temperature. The seventh chapter deals with the solid state and thermal mixing effects. The relevant theory, results obtained and a discussion of these results, are presented. The effect of impurity concentration, defect types, microwave power, the exposure time and the offset from resonance on the polarisation rates and the 13C polarisation are investigated in depth. Finally the effect of applying the DNP treatment on the central and hyperfine lines is discussed. The pulsed DNP process is presented in the eighth chapter. The relevant theory, the effects of matching of the Hartmann-Hahn condition, impurity concentrations and types, on the polarisation rate and signal enhancement of JJC nuclei is given. A comparison to the continuous wave techniques is then made. The ninth chapter summarises the achievements and recommendations for further work. / Physics / D. Phil. (Physics)