Thesis--University of Oklahoma. / Bibliography: leaf 24.

Provamos que o. modelo CPn-1 não permit e formação de par até terceira ordem em teoria de perturbação. A matriz-S dos modelos CPn-1 e Thirring SU(n) foi calculada em perturbação até 2 loops. O cálculo mostra que a matriz-S tem algumas diferenças em relação à esperada. Além disso calculamos a carga não local quantizada do modelo cpn-1 em teoria de perturbação renormalizada 1/n e provamos que ela não é conservada, no entanto quando fermionss são acoplados de uma maneira mínima ou supersimétrica a anomalia se cancela. / We prove that the CPn-1 model does not accomodite pair formation up to third order in perturbation theory. The S-matrix of the Cpn-1 and SU(n) Thirring models was calculated perturbatively up to 2 loops. The calculation shows that the S-matrix has some deviations from the expected exact one. Furthermore, we calculate the quantized nonlocal charge of the CPn-1 model in the framework of renormalized l/n perturbation theory and prove that it is not conserved, nevertheless when fermions are coupled in a minimal or supersymmetric way the anomaly vanishes.

No description available.

The laterally-loaded pile has long been a topic of research interest. Several models of the soil surrounding a pile have been developed for simulation of lateral pile behavior, ranging from simple spring and dashpot models to sophisticated three-dimensional finite-element models. However, results from the available pile-soil models are not accurate due to inherent approximations or constraints. For the springs and dashpots representation, the real and imaginary stiffness are calculated by idealizing the soil domain as a series of plane-strain slices leading to unrealistic pile behavior at low frequencies while the three-dimensional finite-element analysis is very computationally demanding. Therefore, this dissertation research seeks to contribute toward procedures that are computationally cost-effective while accuracy of the computed response is maintained identical or close to that of the three-dimensional finite-element solution. Based on the fact that purely-elastic soil displacement variations in azimuthal direction are known, the surrounding soil can be formulated in terms of an equivalent one-dimensional model leading to a significant reduction of computational cost. The pile with conventional soil-slice model will be explored first. Next, models with shear stresses between soil slices, including and neglecting the soil vertical displacement, are investigated. Excellent agreement of results from the proposed models with three-dimensional finite-element solutions can be achieved with only small additional computational cost. / text

Breast cancer is one of the most common types of cancer affecting women in the world today. To better understand breast cancer initiation and progression modeling biological tissue under physiological conditions is essential. Indeed, breast cancer involves complex interactions between mammary epithelial cells and the stroma, both extracellular matrix (ECM) and cells including adipocytes (fat tissue) and fibroblasts (connective tissue). Therefore, the engineering of in vitro three-dimensional (3D) systems of breast tissues allows a deeper understanding of the complex cell-cell and cell-ECM interactions involved during breast tissue development and cancer initiation and progression. Furthermore, such 3D systems may provide a viable alternative to investigate new drug or drug regimen and to model and monitor concurrent cellular processes during tumor growth and invasion. The development of suitable 3D in vitro models relies on the ability to mimic the microenvironment, the structure, and the functions of the breast tissue. Different approaches to develop a novel 3D breast model have been investigated. Most models use gel scaffolds, including Matrigel® and collagen to generate breast tissue-like structures. However, the physicochemical, mechanical, and geometrical properties of these scaffolds only partially meet the mechanical, physical, and chemical parameters of the breast tissue matrix. In the present studies, we investigated the overall hypothesis that electrospun SF-derived scaffolds promote mammary cell growth and the formation of mammary-like structures depending on the composition and/or coating of the scaffolds with ECM proteins. Through an extensive literature search (1) the importance of 3D modeling of tissues and organs in vivo, (2) 3D modeling of the mammary tissue and currently available models, (3) the properties and applications of SF in tissue modeling and regeneration were reviewed (Chapter 1). Our studies provide evidence of the effects of various concentrations (Chapter 2) of SF along with different electrospinning techniques (Chapter 3) on the structure of electrospun scaffolds and whether those scaffolds provide suitable microenvironments for mammary epithelial cells as determined by MCF10A cell attachment, viability, and structure formation. Further, we investigated the effects of the key ECM proteins collagen I (Chapter 4) and laminin (Chapter 5) used to blend or coat, respectively, SF scaffolds on the attachment, viability and structure formation of mammary epithelial cells. Our studies first highlight the mechanical and physical properties of the different SF-derived scaffolds through various SF concentrations and electrospinning techniques. Second, the biocompatibility of these SF electrospun scaffolds was defined based on MCF10A cell survival and adhesion. Third, our data indicate that scaffolds derived from blended and/or coated SF with collagen I also promoted human mammary cell survival and adhesion. Lastly, our observations suggest that on laminin-coated SF scaffolds MCF10A mammary cells, in the presence of lactogenic hormones, differentiated forming acinus-like structures. Overall, these studies provide evidence that SF electrospun scaffolds closely mimic the structure of the ECM fibers and allow many advantages such as; physical and chemical modification of the microenvironment by varying electrospinning parameters and addition of various proteins, hormones, and growth factors, respectively. Further, coating these SF scaffolds with essential ECM proteins, in particular laminin, promote cell-ECM interactions necessary for cell differentiation and formation of growth-arrested structures, through providing cell integrin binding sites and appropriate chemical cues.

Thesis--University of Oklahoma. / Bibliography: leaves 113-115.

Constructed wetlands (CWs) are artificial systems used for wastewater treatment, whose objective is to reproduce, under controlled conditions, the treatment mechanisms that occur in natural environments, through the exploration and improve the processes that involve the vegetation, porous media and microbial assemblages. Horizontal subsurface flow constructed wetlands (HSSF-CWs) is characterized by flow in a horizontal direction, in a gravel or sand beds planted or unplanted with emergent macrophytes whose the inlet and outlet are horizontally opposed, which allows the wastewater flow through the rhizosphere and have contact with the biofilm formed in subsurface. Traditional studies about CWs focuses on the efficiency of contaminants removal look at systems as a "black-boxes" from empirical approaches and do not distinguish between the different active removals processes. The development of numerical models, in order to helping to identify and improve the role of each element acting in the treatment, whether the properties of the porous media, constructive geometry, flow characteristics, among others, appears as an alternative to reach a more detailed understanding of the internal processes involved in CWs. In general, numerical models consist of governing equations (derived from the mathematical combination of the water balance and Darcy's law), initial conditions (they refer to the distribution of the hydraulic head in the model domain) and boundaries conditions (define the hydraulic or physical boundaries that delimit the model domain). In the last decade, different 1D and 2D numerical models have been developed and applied for the simulation of subsurface flow CWs under conditions of saturated horizontal flow (CWM1-RETRASO and PHWAT), variably saturated vertical flow (FITOVERT and HYDRUS-CW2D) and vertical or horizontally saturated flow (HYDRUS-CWM1). However, few studies regarding the application of 3D numerical models for CWs simulation are reported in the scientific literature. In this study, the hydrodynamic simulation of the porous media in a horizontal subsurface flow constructed wetland was run through the application of a 3D numerical model. The flow patterns were simulated according to the project design and scenarios with changes in the porous media hydrodynamic (hydraulic conductivity) and in the positioning of the wastewater distribution mechanisms (distribution along the cross section with two pipes) in order to verify the influence of these factors in the flow pattern and also to indicate advantages and disadvantages that contribute to the design. The softwares MODFLOW and MODPATH, in the GMS family code, were used for to simulate the direction and flow velocity, hydraulic head and pathlines. The model proved to be a powerful tool to simulation, allowing observing the interdependence between the hydrodynamic parameters and the hydraulic characteristics in the porous media. The simulated scenarios showed the possibility of improving the flow patterns, mainly using two pipes to distribute the wastewater in a more homogeneous way along the cross section of the bed. The use of a porous media with lower hydraulic conductivity also showed improvement in flow characteristics evaluated. However, the general context of wastewater treatment facilities (pretreatment units and tributary loads) should be considered, since materials with low hydraulic conductivity are more susceptible to clogging. Proper design is crucial to improving the treatment conditions in the HSSF-CWs and also to avoid the occurrence of hydraulic problems and damage to the treatment, such as the clogging. / Wetlands construídos (WCs) são tecnologias empregadas para o tratamento de águas residuárias, cujo objetivo é reproduzir, sob condições controladas, os mecanismos de depuração que ocorrem em meios naturais, através da exploração e aperfeiçoamento dos processos que envolvem a vegetação, o substrato e os microrganismos. Wetlands construídos de escoamento subsuperficial de fluxo horizontal (WCFH) são caracterizados pelo fluxo em direção horizontal através de um leito de cascalho ou areia, vegetado ou não com macrófitas emergentes, cujas entrada e saída dos efluentes são horizontalmente opostas, o que permite que as águas residuárias fluam através da rizosfera e tenham contato com o biofilme formado em subsuperfície. Tradicionalmente, os estudos sobre WCs incidem apenas sobre a remoção das concentrações de contaminantes, considerando esses sistemas como “black-boxes” a partir de abordagens empíricas, sem fazer distinção entre os diferentes processos atuantes. O desenvolvimento de modelos numéricos, como forma de auxiliar a identificar e aperfeiçoar o papel de cada elemento atuante no tratamento, quer sejam as propriedades do meio poroso, a geometria construtiva, as características de fluxo, entre outros, surge como alternativa para o alcance de uma compreensão mais detalhada dos processos internos intervenientes nos WCs. De uma forma geral, os modelos numéricos são constituídos por equações governantes (derivada da combinação matemática da equação de balanço de água e da lei de Darcy), por condições iniciais (dizem respeito à distribuição da carga hidráulica no domínio do modelo) e por condições de contorno (definem as fronteiras hidráulicas ou físicas que delimitam o domínio do modelo). Na última década, diferentes modelos 1D e 2D foram desenvolvidos e aplicados para a simulação de WCs de escoamento subsuperficial em condições de fluxo horizontal saturado (CWM1-RETRASO e PHWAT), vertical variavelmente saturado (FITOVERT e HYDRUS-CW2D) e vertical ou horizontal variavelmente saturado (HYDRUS-CWM1). Porém, poucas experiências relativas à aplicação de modelos 3D para simulação de WCs são relatadas pela literatura científica. Neste trabalho, a simulação da hidrodinâmica do meio poroso de um sistema de tratamento de efluentes do tipo wetlands construídos de escoamento subsuperficial de fluxo horizontal foi realizada por meio da aplicação de um modelo numérico 3D. Foram simuladas as condições de fluxo conforme as especificações de um projeto de engenheria, e também cenários com mudanças nas características hidrodinâmicas do meio poroso (condutividade hidráulica) e no posicionamento dos mecanismos de distribuição das águas residuárias (distribuição ao longo da seção transversal por meio de duas tubulações) visando verificar a influência desses fatores no sistema de fluxo e também indicar vantagens e desvantagens que contribuam para a elaboração de projetos. Os softwares MODFLOW e MODPATH, executados por meio da interface GMS, foram utilizados para a simulação da direção e velocidade de fluxo, nível hidráulico e linhas de trajetória das partículas transportadas por advecção. O modelo provou ser uma ferramenta poderosa para a simulação, permitindo visualizar a interdependência entre os parâmetros hidrodinâmicos e as características hidráulicas do meio poroso. Os cenários simulados mostraram a possibilidade de melhoria dos padrões de fluxo, principalmente por meio do uso de duas tubulações para distribuição dos efluentes de forma mais homogênea ao longo da seção transversal do leito. O uso de materiais com menor condutividade hidráulica também apresentou melhoria nas características de fluxo avaliadas. Porém, deve-se considerar o contexto geral das instalações de tratamento das águas residuárias (unidades de tratamento preliminar e cargas afluentes), visto que materiais com baixa condutividade hidráulica são mais susceptíveis ao entupimento. A concepção adequada é crucial para melhorar as condições de tratamento verificadas nos WCFH e também para evitar a ocorrência de danos e problemas hidráulicos, como a estagnação de fluxo em zonas de baixa velocidade de escoamento.

Orientador: Orlando Luis Goulart Peres / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-23T00:42:36Z (GMT). No. of bitstreams: 1 Pasquini_PedroSimoni_M.pdf: 4615786 bytes, checksum: d94409b2794db9d8be03e41a933166d1 (MD5) Previous issue date: 2013 / Resumo: Apesar do grande sucesso alcançado pela teoria do modelo padrão baseada nas simetrias SU&subC;(3)? SU&subL;(2)? U(1), ainda existem alguns desafios a serem conquistados. Uma maneira direta de resolver os problemas é interpretar o modelo padrão (SM) como um modelo efetivo cuja validade chega até uma escala de energia E ¿ ?, na qual ele deixa de ser válido. Suspeita-se de que ? ~ TeV, e poderá ser observada nova física com as análises do Large Hadron Collider (LHC). No sentido de teoria efetiva do SM, é possível explicar a origem da oscilação de neutrinos [2] via mecanismo de Higgs, combinado com o modelo See-saw[1]. Esse mecanismo produz um operador 5-dimensional renormalizável que gera os ângulos de mistura dos neutrinos. Esse trabalho faz um estudo sobre a evolução dos ângulos de mistura dos neutrinos com a energia, via equações do grupo de renormalização. Comparando o modelo padrão com sua possível extensão, o modelo supersimétrico e modelos com uma dimensão espacial extra. A evolução dos ângulos de mistura é bem sutil mesmo para altas energias na ordem de 14TeV, ~ 2:5% para os modelos padrão e supersimétrico, com evolução com a escala na forma logarítmica e, um pouco mais acentuada, ~ 15% para o modelos com dimensões extras, cujo resultado esperado pela dependência quadrática na escala de energia problema. A análise foi feita para alguns valores nos raios das dimensões extras, e foi visto, como o esperado, que quanto menor o raio, menor é a mudança visível a baixas energias. Tais resultados podem ajudar na seleção de modelos, entretanto a variação no ângulo de mistura não é observável fora dos erros experimentais atuais- de medições já realizadas sobre oscilação de neutrinos. A variação entre os modelos é, portanto, leve, de forma que não é possível verifica-la com os dados atuais / Abstract: In spite of the great success reached by the Standard Model (SM) of particle physics, there are some puzzles that seems as a new physics at the ~ TeV scale, such as the origin of neutrino mass and neutrino oscillations. The framework for dealing with those effects are the interpretation of the SM as an effective theory valid at maximum energy E ¿ ?, where ? ~ TeV. In this work we study the evolution of neutrino masses and their mixing angles, which are supposed to be generated via the 5-dimensional Weinberg operator as a consequence of the see-saw mechanism. The studied models are: (1) A minimal extension of the standard model with three heavy steril neutrinos, (2) Minimal Supersymmetric Standar Model, (3) Minimal Unified Extra Dimensions in 5D. We show that the running of the mixing are very sutil in the _rst two models, less then 10% for ?12, and a bit bigger, of order of 10%, also ?12, in a power law growth with energy, as expected by the effectiviness nature of the model. The neutrino mass square diference tend to decrease, but not enough to reach a equality of masses in some energy scale near ~ TeV / Mestrado / Física / Mestre em Física

"Fluid-structure interaction arises in a wide array of technological applications including naval and marine hydrodynamics, civil and wind engineering and flight vehicle aerodynamics. When a fluid flows over a bluff body such as a circular cylinder, the periodic vortex shedding in the wake causes fluctuating lift and drag forces on the body. This phenomenon can lead to fatigue damage of the structure due to large amplitude vibration. It is widely believed that the wake structures behind the structure determine the hydrodynamic forces acting on the structure and control of wake structures can lead to vibration control of the structure. Modeling this complex non-linear interaction requires coupling of the dynamics of the fluid and the structure. In this thesis, however, the vibration of the flexible cylinder is prescribed, and the focus is on modeling the fluid dynamics in its wake. Low-dimensional iterative circle maps have been found to predict the universal dynamics of a two-oscillator system such as the rigid cylinder wake. Coupled map lattice (CML)models that combine a series of low-dimensional circle maps with a diffusion model have previously predicted qualitative features of wake patterns behind freely vibrating cables at low Reynolds number. However, the simple nature of the CML models implies that there will always be unmodelled wake dynamics if a detailed, quantitative comparison is made with laboratory or simulated wake flows. Motivated by a desire to develop an improved CML model, we incorporate self-learning features into a new CML that is trained to precisely estimate wake patterns from target numerical simulations and experimental wake flows. The eventual goal is to have the CML learn from a laboratory flow in real time. A real-time self-learning CML capable of estimating experimental wake patterns could serve as a wake model in a future anticipated feedback control system designed to produce desired wake patterns. A new convective-diffusive map that includes additional wake dynamics is developed. Two different self-learning CML models, each capable of precisely estimating complex wake patterns, have been developed by considering additional dynamics from the convective-diffusive map. The new self-learning CML models use adaptive estimation schemes which seek to precisely estimate target wake patterns from numerical simulations and experiments. In the first self-learning CML, the estimator scheme uses a multi-variable least-squares algorithm to adaptively vary the spanwise velocity distribution in order to minimize the state error (difference between modeled and target wake patterns). The second self-learning model uses radial basis function neural networks as online approximators of the unmodelled dynamics. Additional unmodelled dynamics not present in the first self-learning CML model are considered here. The estimator model uses a combination of a multi-variable normalized least squares scheme and a projection algorithm to adaptively vary the neural network weights. Studies of this approach are conducted using wake patterns from spectral element based NEKTAR simulations of freely vibrating cable wakes at low Reynolds numbers on the order of 100. It is shown that the self-learning models accurately and efficiently estimate the simulated wake patterns within several shedding cycles. Next, experimental wake patterns behind different configurations of rigid cylinders were obtained. The self-learning CML models were then used for off-line estimation of the stored wake patterns. With the eventual goal of incorporating low-order CML models into a wake pattern control system in mind, in a related study control terms were added to the simple CML model in order to drive the wake to the desired target pattern of shedding. Proportional, adaptive proportional and non-linear control techniques were developed and their control efficiencies compared."

Foram medidas funções de excitação para a fusão completa dos sistemas 16O+46,50Ti em energias abaixo e em torno da barreira Coulombiana. A seção de choque de fusão foi obtida utilizando-se os métodos da espectroscopia em linha e fora da linha através da soma das seções de choque dos canais de decaimento do núcleo composto formado, observados experimen- talmente. As vantagens e limitações do método são discutidas em detalhes. As funções de excitação da fusão dos sistemas citados foram analisados utilizando-se modelos semiclássicos de penetração de barreira. Através desta análise determinamos o raio e a altura da barreira de fusão para estes sistemas. Os valores obtidos concordam com valores da literatura na mesma região de massa. A seção de choque de fusão calculada pelo modelo de penetração de barreira unidimensional utilizando potenciais que descrevem a interação entre íons pesados, é subestimada em energias abaixo da barreira Coulombiana. A introdução da vibração de ponto zero da superfície dos núcleos interagentes, apesar de produzir um aumento da seção de choque em energias sub- Coulombianas, não consegue reproduzir os dados de maneira satisfatória, pois prevê uma diferença isotópica nas funções de excitação que não e observada experimentalmente. As previsões do modelo estatístico para o decaimento do núcleo composto (programa CASCA- DE) apresentam uma concordância satisfatória para os canais de decaimento mais intensos. / Excitation functions for complete fusion of the systems 16O + 46,50Ti, with energies near and below the Coulomb barrier, were measured. With the use of the in-beam and out of beam spectroscopy, the formation of the compound nucleus was experimentally detected. The fusi- on cross section was then attained by the sum of all observed compound nucleus decay chan- nels. The limitation and advantages of measurements methods are discussed. Theoretical analysis of the experimental results using the semi-classical barrier penetration model allowed us to obtain the fusion barrier height and radius for the studied systems. These values are in good agreement with others reported for this mass range. Using the unidimensionaL barrier penetration model with different nuclear potentials, descri- bing the heavy ion interactions gave theoretical fusion cross section values systematically smaller than our measured values in the energy region below the Coulomb barrier. The introduction of the nuclear surface zero point vibrations enhances the theoreticaL fusion cross sections in the sub-Coulomb region, but simultaneously introduces an isotopic difference in the fusion excitation functions that is not observed experimentally. The statistical model predictions for the compound nucleus decay (calculated by the CASCADE program) show reasonable agreement for the more intense decay channels.