This dissertation demonstrates the behavior of the electronic transport properties in the presence of a temperature gradient in disordered systems near the metal-insulator transition. In particular, we first determine the d.c. conductivity, the thermopower, the thermal conductivity, the Lorenz number, the figure of merit, and the specific heat of a three-dimensional Anderson model of localization by two phenomenological approaches. Then we also compute the d.c. conductivity, the localization length and the Peltier coefficient in one dimension by a new microscopic approach based on the recursive Green's functions method. A fully analytic study is difficult, if not impossible, due to the problem of treating the intrinsic disorder in the model, as well as, incorporating a temperature gradient in the Hamiltonian. Therefore, we resort to various numerical methods to investigate the problem.

The main objective of this dissertation is to develop large-eddy simulation (LES) based computational tools for supersonic inlet and combustor design. In the recent past, LES methodology has emerged as a viable tool for modeling turbulent combustion. LES computes the large scale mixing process accurately, thereby providing a better starting point for small-scale models that describe the combustion process. In fact, combustion models developed in the context of Reynolds-averaged Navier Stokes (RANS) equations exhibit better predictive capability when used in the LES framework. The development of a predictive computational tool based on LES will provide a significant boost to the design of scramjet engines. Although LES has been used widely in the simulation of subsonic turbulent flows, its application to high-speed flows has been hampered by a variety of modeling and numerical issues. In this work, we develop a comprehensive LES methodology for supersonic flows, focusing on the simulation of scramjet engine components. This work is divided into three sections. First, a robust compressible flow solver for a generalized high-speed flow configuration is developed. By using carefully designed numerical schemes, dissipative errors associated with discretization methods for high-speed flows are minimized. Multiblock and immersed boundary method are used to handle scramjet-specific geometries. Second, a new combustion model for compressible reactive flows is developed. Subsonic combustion models are not directly applicable in high-speed flows due to the coupling between the energy and velocity fields. Here, a probability density function (PDF) approach is developed for high-speed combustion. This method requires solution to a high dimensional PDF transport equation, which is achieved through a novel direct quadrature method of moments (DQMOM). The combustion model is validated using experiments on supersonic reacting flows. Finally, the LES methodology is used to study the inlet-isolator component of a dual-mode scramjet. The isolator is a critical component that maintains the compression shock structures required for stable combustor operation in ramjet mode. We simulate unsteady dynamics inside an experimental isolator, including the propagation of an unstart event that leads to loss of compression. Using a suite of simulations, the sensitivity of the results to LES models and numerical implementation is studied. / text

Submitted by Priscila Nascimento (pnascimento@icict.fiocruz.br) on 2012-11-30T12:31:09Z No. of bitstreams: 1 beatriz-cyranka.pdf: 1720638 bytes, checksum: c436adb348584d5a5a8213fccdef6ea6 (MD5) / Made available in DSpace on 2012-11-30T12:31:09Z (GMT). No. of bitstreams: 1 beatriz-cyranka.pdf: 1720638 bytes, checksum: c436adb348584d5a5a8213fccdef6ea6 (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil. / Novas tecnologias, como o sistema isolador para ensaios de esterilidade vieram a contribuir com a incorporação de um melhor desempenho destes ensaios no controle de qualidade das indústrias farmacêuticas.Este trabalho teve como objetivo a verificação do processo de biodescontaminação dentro do sistema isolador de Bio-Manguinhos, utilizado como agente esterilizante o gás de peróxido de hidrogênio. Foram utilizadas como biocarga para redução de contaminação microbiológica três concentrações dos microrganismos, Candida albicansATCC 10231, Clostridium sporogenesATCC 11437 eMicrococcus luteusATCC 9341, impregnadas em discos de filtro de celulose. Os estudos de cinética de crescimento dos microrganismos foram realizados para um melhor entendimento do seumetabolismo, bem como aspectos gerais de crescimento que contribuíram para ressaltar que a Candida albicans inicia sua fase exponencial de crescimento na segunda hora do cultivo e finaliza esta etapa na sexta hora do cultivo, com produção máxima de células viáveis, fato observado também no microrganismo Micrococccus luteus. Para o cultivo doClostridium sporogenes o crescimento foi mais lento com uma curva de crescimento com 60 horas de cultivo total. A produção de maior número de células para o Clostridiumfoi alcançada na vigésima quarta hora de cultivo, assim como a maior produção de esporos. Foi estabelecida, ao longo da curva de crescimento, a relação entre densidade ótica e número de células viáveis, relação essa importante para o estabelecimento das condições do estudo em relação à biocarga empregada de cada microrganismo no momento do desafio no sistema isolador. A capacidade de descontaminação avaliada dentro do sistema isolador com o biocida peróxido de hidrogênio revelou o tempo de exposição ao gás de 10 minutos, como resultado final satisfatório apresentando redução total da carga microbiana com destruição total das células viáveis, assim como as formas esporuladas do Clostridium sporogenes. Desta forma conclui-se que o peróxido de hidrogênioé um biocida de eficácia comprovada, nas variáveis deste estudo e o processode descontaminação no sistema isolador de Bio-Manguinhos é compatível comsua atividade finalística na produção de insumos para a saúde. / New technologies such as isolator system for sterility tests came to help with the incorporation of a better performance of these kinds of tests in quality control of pharmaceutical companies. This study aimed to verify the decontamination process within the system isolator of Bio-Manguinhos, usinghydrogen peroxide gas as a sterilizing agent. Three concentrations of microorganisms were used as bioburden for the microbiological contamination reduction, Candida albicansATCC 10231, Clostridium sporogenesATCC 11437 and Micrococcus luteusATCC 9341, impregnated in cellulose filter discs. Studies of growth kinetics of microorganisms were carried out to a better understanding of theirmetabolism, as well as general aspects of growth that contributed to emphasize that the Candida albicansbegins its exponential growth phase in the second hour of cultivation and this step ends at the sixth hour cultivation, with maximum yield of viable cells, this was also observed in the Micrococcus luteusmicroorganism. For the Clostridium sporogenescultivation, growth was slower with a 60 hours growth curve of total culture. The production of more cells for Clostridiumwas achieved in the twenty-fourth hour of cultivation, as well as the maximum spores production. It was established along the growth curve the relationship between optical density and numberof viable cells, this relationship was important to establish the conditions of the study related to the bioburden of each microorganism used to challenge the isolator system. The decontamination capacity evaluated within the isolator system with the hydrogen peroxide biocide showed that the gas exposure time of 10 minutes wassatisfactory demonstrating total reduction of the microbial load with total destruction of viable cells, as well as the sporulated forms of Clostridium sporogenes. Thus it is concluded that hydrogen peroxide is a proved effective biocide, in the variables of this study and decontamination process in the Bio-Manguinhos insulator system is compatible with its main activity in the production of health supplies.

Orientador: Fernando Galembeck / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-16T12:34:45Z (GMT). No. of bitstreams: 1 Gouveia_RubiaFigueredo_D.pdf: 6255414 bytes, checksum: b9783ee801d3d18f57579c596a700bab (MD5) Previous issue date: 2010 / Resumo: Os fenômenos eletrostáticos e suas consequências são familiares para a maioria das pessoas, mas o conhecimento sobre este tópico ainda é bastante empírico. Persistem grandes dificuldades na correlação de idéias fundamentais da teoria atômico-molecular com observações experimentais da eletrostática de materiais isolantes. A hipótese explorada nessa tese é: a atmosfera é uma fonte de cargas elétricas em isolantes, devido à partição de grupos OH- e H+ associados à adsorção de água. Logo, interações específicas entre íons presentes na água e sólidos isolantes contribuem para os padrões de cargas. Neste trabalho foram analisados padrões eletrostáticos em uma superfície de sílica recoberta por eletrodos de ouro produzidos por técnicas microlitográficas e partículas amorfas de fosfato de alumínio e sílica de Stöber utilizando a microscopia de força Kelvin (KFM) sob umidade relativa controlada. Os potenciais elétricos sobre a superfície de sílica dependem fortemente da umidade relativa, bem como da polarização dos eletrodos de ouro. A formação e dissipação dos padrões eletrostáticos são mais rápidas sob altas umidades. Já em baixas umidades a preservação dos potenciais elétricos é mais efetiva. Os potenciais elétricos das partículas de sílica e fosfato de alumínio são fortemente influenciados pela umidade relativa, sendo alterados mesmo em um ambiente completamente isolado eletricamente e aterrado. Os potenciais são modificados por eventos de adsorção e dessorção de água: sílica de Stöber torna-se mais negativa com o aumento da umidade, enquanto o fosfato de alumínio torna-se menos negativo, na ausência de qualquer ação de indução por um campo elétrico. Os resultados mostraram que a adsorção de água modifica os padrões de cargas de superfícies inorgânicas em escala nanométrica e que a eletroneutralidade não é uma característica geral de materiais isolantes. Neste trabalho também foram examinadas propriedades mecânicas de rigidez e adesão em nanoescala de partículas de fosfato de alumínio e dióxido de titânio, utilizando a microscopia de força pulsada digital (DPFM). As partículas apresentam uma grande heterogeneidade mecânica, mostrando domínios bastante diferenciados entre si. A nanoindentação da ponteira do AFM sobre as partículas mostrou que o dióxido de titânio apresenta maiores valores de rigidez, módulo de Young, força e energia de adesão e de histerese na deformação de suas superfícies. / Abstract: Electrostatic charging is familiar to most persons but knowledge on this topic is still rather empiric, mainly because fundamental ideas on the structure of matter are not well connected to the phenomenology of insulator charging. This thesis explores the following hypothesis: the atmosphere is as an electric charge reservoir for insulators, due to the partition of OH- and H+ groups associated to water adsorption. Thus, specific interactions between ions of adsorbed layers of water and insulating solids contribute to charge patterning. In this work, electrostatic patterning was examined in a silica surface partially covered with sets of interdigitated gold electrodes produced by microlithography techniques and also in aluminum phosphate and Stöber silica amorphous particles, using Kelvin force microscopy (KFM) under controlled relative humidity. Electric potentials acquired from the silica surface depend largely on the relative humidity as well as on the applied potentials at the gold electrodes. Pattern formation and dissipation are much faster under high relative humidity while the charged or discharged silica states are both more stable at low humidity. The electric potential measured along the surface of amorphous particles changes with relative humidity within an electrically shielded and grounded environment. Thus, water adsorption and desorption modify charge status of these particles: Stöber silica surface becomes more negative at higher humidity while aluminum phosphate becomes less negative, without any external electric potential or inductive input. These results show that water adsorption modifies charge status of inorganic surfaces and that electroneutrality is not a widespread characteristic of insulating materials. Another section of the thesis describes local nanomechanical stiffness and adhesion properties for aluminum phosphate and titanium dioxide particles, using digital pulsed force microscopy (DPFM). Aluminum phosphate and titanium dioxide particle domains present a large degree of heterogeneity. Aluminum phosphate particles are softer materials than titanium dioxide, undergoing greater nanoindentation of the AFM tip. On the other hand, titanium dioxide particle surfaces present larger stiffness, Young modulus, tipadhesion force, energy dissipated by hysteresis and detachment energy than aluminum phosphate particles. / Doutorado / Físico-Química / Doutor em Ciências

Neste trabalho apresenta-se uma alternativa para utilização de vidros laminados provenientes de rejeitos industriais ou pós-consumo. Reciclando o vidro laminado, por meio de uma série de moagens, pode-se obter dois tipos de rejeitos: vidros de partículas pequenas (200 e 325 mesh), que não conseguem ser reaproveitados pela indústria vidreira, e filme de poli(vinil butiral) - PVB - impregnado com uma pequena quantidade de carga, que tem como destino os aterros. No presente estudo, esses dois resíduos foram aproveitados na fabricação de vernizes curados por radiação ultravioleta empregados para proteção de pisos de madeira. O filme de PVB foi utilizado na formulação de um isolante, em razão de sua alta flexibilidade e boa aderência à madeira, e o vidro de baixa granulometria foi empregado como carga nos vernizes chamados de alto tráfego para o aumento da resistência à abrasão dos mesmos (propriedade fundamental de vernizes para pisos de madeira). Pelos resultados obtidos, verificou-se que o isolante preparado com o filme de PVB em solução alcoólica e misturado a um monômero acrílico trifuncional, como o trimetilolpropano triacrilato (TMPTA), quando aplicado sobre pisos de madeira, obteve-se bons resultados de aderência, arrancamento e flexibilidade, podendo assim substituir os isolantes utilizados atualmente, produtos com cura por radiação ultravioleta, em base aquosa, e que apresentam alto custo por serem preparados com resinas importadas. Foi observado que quanto maior a quantidade de solução de PVB, melhor a flexibilidade do filme e, conseqüentemente, melhor a resistência ao arrancamento do revestimento. Os vidros de baixa granulometria apresentaram resultados muito satisfatórios quando utilizados como carga nos vernizes de alto tráfego, especialmente ao se combinarem com o óxido de alumínio (carga atualmente utilizada nesses sistemas), aumentando ainda mais a resistência à abrasão dos vernizes e também a estabilidade dos vernizes (quanto à sedimentação e à geleificação). Para todas as combinações de cargas preparadas neste trabalho foram bons os resultados obtidos, podendo-se optar pela utilização daquelas com maior quantidade de vidro, uma vez que este, por tratar-se de um resíduo, torna tais combinações mais econômicas. / The present work features an alternative for the utilization of the windshield after its use. The recycling of the laminated glass, through a series of grindings, make possible to obtain two kinds of materials: glasses of small particles (200 and 325 mesh), that cannot be recovered in the glass industry, and a poly(vinyl butiral) - PVB - sheet impregnated with a small amount of filler, that has as final disposal the sanitary landfill. In this study these two materials were introduced in the formulation of ultraviolet curing varnishes used to the protection of wood flooring. The film of PVB was used in the formulation of a primer, due to its high flexibility and good adherence to the wood, and the glass of low granulometry was used as a filler in the so-called high traffic varnish, to increase the abrasion resistance (main property of these varnishes). The results obtained showed that the primer prepared with the PVB sheet in alcoholic solution, mixed with a trifunctional acrylic monomer, like TMPTA, when applied on wood flooring, obtained good results of adherence, scrape adhesion, flexibility and stability and could substitute the primers used nowadays that are UV curing products, however water based ones, and that has a high cost because of the imported resins that are used in their formulations. It was observed that larger the amount of solution of PVB, better the flexibility of the film and, consequently, better its scrape adhesion. The glasses of low granulometry also presented very satisfactory results when used as fillers in the high traffic varnishes, mainly when in combination with aluminium oxide (filler used in these systems), increasing more the abrasion resistance of the varnishes and also their stability (the sedimentation and geleification have showed better results). To all filler combinations studied in this work the results were good and the best one can be the ones that presented the largest amount of glass, since as a residue, make these combinations more economical.

In dieser Arbeit wird vor allem der Einflu¨s eines quasiperiodischen Gitters und dessen Topologie auf die Lokalisierungseigenschaften der Eigenzust¨ande und die elektronische Zustandsdichte untersucht. Ausgehend vom Penrosegitter und dessen dreidimensionalen Analogons werden auch die quasiperiodischen Gitter aus anderen lokal isomorphen Klassen untersucht. Durch den Einbau von Phasonendefekten werden weiterhin Random-Tiling-Gitter konstruiert. Ferner wird untersucht, inwieweit ein quasiperiodisches Gitter den Metall-Isolator-¨Ubergang beeinflu¨st. Zwei- und dreidimensionale Quasigitter werden mit der Gridmethode nach de Bruijn konstruiert und ¨Random Tiling¨-Gitter durch den Einbau von Phasonendefekten erzeugt. Im Vertexmodell wird jeder Ecke eines Rhombus ein s-Atomorbital zugewiesen mit ausschlie¨slich N¨achster-Nachbar-Wechselwirkung entlang der Kanten. Aus den berechneten Eigenzust¨anden werden Zustandsdichten berechnet und deren Partizipationzahlen und R¨uckkehrwahrscheinlichkeiten bestimmt, um das Lokalisierungsverhalten zu untersuchen. Im Penrosegitter zeigen die Zustandsdichten eine hohe Entartung in der Bandmitte. Die entsprechenden Zust¨ande sind stark lokalisiert (¨confined states¨) und durch eine Energiel¨ucke von den anderen Energieniveaus getrennt. Die Zust¨ande an der Bandkante sind dagegen ausgedehnt. Durch die Phasonen werden die Zustandsdichte und das Lokalisierungsverhalten ver¨andert. Im Falle dreidimensionaler Quasigitter ist die Energiel¨ucke verschwunden, und man findet eine wesentlich kleinere Anzahl entarteter Zust¨ande in der Bandmitte. Die anderen Zust¨ande in der Bandmitte sind nicht lokalisiert.

This thesis is devoted to numerical simulations of integrated optical isolators and circulators. The results contain: Polarization independent isolators Different magneto-optical configurations are required to produce large nonreciprocal phase shifters for orthogonally polarized modes. The polarization independent isolator can be realized by placing two different nonreciprocal phase shifters into the interferometer arms. The light interferes constructively or destructively at the end of the interferometer depending on the propagation direction. Another possibility is to find a magnetic configuration that yields equal nonreciprocal phase shift for transverse electric (TE) and transversemagnetic (TM) modes. Compared to the concept of polarization independent isolators with two different phase shifters in the interferometer arms, the concept with a polarization independent phase shifter has an advantage: the entire length of the device can be almost halved placing an additional nonreciprocal phase shifter into the second arm. Another advantage is that the power loss inside the nonreciprocal phaseshifter may differ from that in the rest of the structure. For the non-symmetrical setup it can lead to a reduction of the device performance. Utilization of multimode waveguides in magneto-optical devices The principle distinction of a Mach-Zehnder type isolator and an isolator based on multimode imaging is that in the latter case the input power is distributed between modes propagating in the same waveguide, whereas in the first case two separate waveguides are used. Nonreciprocal phaseshifters with different effects on guided modes are needed to produce a magneto-optic multi-mode imaging (MMI) isolator or circulator. Multimode imaging splitters with non zero phase difference between the output modes can be used in integrated optical isolators. If the essential phase difference is utilized by the splitter, the rest of the interferometer should be symmetrical.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23490号 / 工博第4902号 / 新制||工||1766(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 五十嵐 晃, 教授 高橋 良和, 准教授 北根 安雄 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No description available.

<p>Seismic isolation is a seismic design philosophy that aims to reduce the demand on structures as opposed to increasing their capacity to endure forces. Seismic isolation can be achieved by placing isolating bearings with relatively low stiffness compared to the structure itself beneath the superstructure. This low stiffness layer increases the structural period, shifting the structure into a period range of low seismic energy content.</p> <p>The objectives of this research were to investigate the dynamic properties, durability and limitations of stable unbonded fibre reinforced elastomeric isolator (SU-FREI) bearings. Vertical compression testing indicated the bearings possessed adequate vertical stiffness. Due to lack of bonding at the bearing interface surfaces rollover deformation was observed to occur during lateral cyclic testing. This response behaviour was found to result in advantageous effective lateral stiffness and damping properties. The bearings maintained stability during rollout testing while serviceability and fatigue testing both conformed to code specified test specimen adequacy limitations. Experimental shake table testing showed that the isolated structure behaved essentially as a rigid body during testing. Test results showed that a SU‐FREI isolation system significantly reduced the seismic demand on the structure.</p> <p>Modelling of the bearings dynamic properties was completed using a bilinear model and a backbone curve model. Both models showed adequate results in predicting experimental peak responses. A simplified design spectrum analysis was presented and used to model the structure in four Canadian cities. This design spectrum analysis approach showed adequate capabilities in predicting peak response values, such that the method could be used in preliminary analysis and design of isolated structures.</p> / Master of Applied Science (MASc)