Os modos vibracionais localizados dos pares H-H-, D-D- e H-D- em KCl, KBr, KI, RbCl e NaCl foram estudados para diversas configurações. As frequências dos modos infravermelho ativos determinados experimentalmente mostram boa concordância com o modelo de dois osciladores harmônicos acoplados. A largura de linha para os diferentes modos nos cristais examinados é discutida. A dependência com a temperatura da largura de linha para os modos transversais T1 e T2 no sistema KCl+ H- H-, indica que o alargamento das mesmas é devida ao \"mecanismo de decomposição\", no qual dois fônons são criados. Estes fônons são devidos ao decaimento do modo localizado em fase num fônon acústico da rede e num fônon localizado fora de fase. Propriedades gerais, como a lei de Ivey e diversas outras particularidades dos halogenetos alcalinos estudados são apresentadas / The localized vibrational modes of H-H-, D-D- and H-D- in KCl, KBr, KI, RbCl and NaCl were studied for different pair configurations. The measured frequencies of the infrared active modes were found to be in good agreement with a model of two coupled harmonic oscillators. The line width for different modes in the salts studied is discussed. The temperature dependence for the transversal modes T1 and T2 of the line width for the H- H- pairs in KCl indicates that the broadening of these lines is due to the \"decomposition mechanism\", that generates two phonons. The generated phonons due to the decay of the localized phonon that corresponds to the out of phase vibration of the H- H- pair. The general properties, as the Ivey law and several particulars of the properties in the alkali-halides studied are presented

Orientador: Peter Alexander Bleinroth Schulz / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-13T03:40:09Z (GMT). No. of bitstreams: 1 PaezGonzalez_CarlosJose_M.pdf: 17726649 bytes, checksum: 92453a3b81784c5899922a7943ef209f (MD5) Previous issue date: 2009 / Resumo: Neste trabalho estudamos a localização dos modos vibracionais de três modelos simples do DNA: cadeia unidimensional,dupla cadeia e o modelo de quatro cadeias; nestes modelos substituímos os grupos atômicos por massas efetivas ligadas entre si com molas. Para cada modelo calculamos e diagonalizamos a matriz dinâmica obtendo os modos vibracionais e suas freqüências. Cada componente de um modo vibracional representa a amplitude da oscilação nesse sitio, permitindo calcular a razão de participação e a fiutuação relativa desse modo. A partir destas grandezas se mostrou que nos sistemas quasi-unidimensionais (dupla cadeia e quatro cadeias) existe um intervalo a baixas freqüências onde todos os modos vibracionais são estendidos independentemente da seqüencia e as possíveis constantes de mola. / Abstract: ln this work we studied the localization of vibrational modes of three simple models of DNA: unidimensional chain, double chain and the model of falir chains. ln these models, atomic groups were replaced by effective fiasses linked to each other by springs. For each model, the dynamic matrix was calculated and diagonalized obtaining the vibrational modes with their frequencies. Each component of a vibrational mode represents the amplitude of the oscillation in that site, allowing the calculation of the participation fatia and the relative fluctuation of that mode. From these quantities we showed that there is a range at low frequencies in quasi-one-dimensional systems (double chain and falir chains) where alI vibrational modes are extended regardless the sequence and spring constants. / Mestrado / Física da Matéria Condensada / Mestre em Física

Cria-se, nesta pesquisa, as ferramentas de estudo de uma alternativa inovadora de irrigação localizada superficial, que consiste na escavação do terreno ao redor da base da planta na forma de um anel grosso que produza bulbos úmidos equivalentes aos gerados por qualquer um gotejador. Estas bacias deverão ser conectadas por meio de sulcos compactados que, além de servir como condutores semi-impermeáveis, criam um micro sistema de coleta de água. Capas radiculares podem ser colocadas dentro das bacias com o intuito de eliminar as perdas por evaporação, evitar o crescimento de ervas daninhas e até incrementar o rendimento da colheita. Desenvolve-se para este fim um modelo matemático misto do tipo balanço volumétrico e onda cinemática modificado com a teoria de onda de choque, que utiliza um modelo de infiltração baseada na inédita aplicação do princípio da maximização da entropia multidirecional. Este novo modelo de infiltração em comparação com os modelos de Horton, Philips e Kostiakov determina, além de menores erros padrões, maiores coeficientes de correlação, em média de 1.2% e 8.9 % e máximos de 2.5% e 68% nos infiltrômetros por sulcos e anel duplo, respectivamente. / The doctorate research creates the tools for study a new alternative of localized superficial irrigation. The system purposed consists in a ground excavation around the plant base. The form of this is same as a big ring, that produces an humid bulb in the root zone equivalent to a drooping system. This cavities need to be connected by furrows that\'s beyond serves for being a semi impermeable conductor of water creates a micro-system of water harvesting. Root layers can be placed inside of the cavities with intention to eliminate the losses for evaporation, to prevent the growth of harmful grass and until to improve the collect income. For this ending development a modify volumetric balance and cinematic wave model that incorporated a new infiltration model. This infiltration model is based in the in edit maximization of the multidirectional entropy. Comparing the new entropic model with the models of Horton, Philips and the modified model of Kostiakov, the entropic one, it was determined a lesser standard error and a bigger correlation coefficient, in average of 1.2% and 8.9 % for the furrows and double ring infiltrometers respectively and a maximum of 2.5% and 68%.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14624号 / 工博第3092号 / 新制||工||1460(附属図書館) / 26976 / UT51-2009-D336 / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 引原 隆士, 教授 北野 正雄, 准教授 山田 啓文 / 学位規則第4条第1項該当

Pitting corrosion is one of the most destructive types of metal loss. The purpose of this study was to investigate the evolution, or in other words, the propagation, of a single pit in carbon steel after the initiation stage. In view of the chemical and electrochemical reactions inside a single pit in carbon steel, a two dimensional model that allows the prediction of pit evolution was developed. Eleven species in aqueous sodium chloride solution and two neutral complexes were considered in the model. Given that the active-passive transition of a metal is a key phenomenon in pitting, the equations used to construct a Pourbaix diagram for iron were incorporated in the model as rules to govern passivation behaviour. By using the finite element package COMSOL Multiphysics as a tool, the Nernst-Planck equations for the mass transport and potential variations were solved. In addition, the multiphysics model was extended with Moving Boundary (ALE) mode to predict shapes of pits. The results of the study were that the model was able to investigate migration of ionic species, account for the active-passive transition of metal and also able to show the effect of solid precipitation. The model was able to show movement of the boundaries of a pit and hence, predict the shapes of pit at a given range of time. The results were discussed in comparison to the Pourbaix diagram of iron and compared with the experimental results and published models reported in literature. The principal conclusion is that modelling corrosion activities with integrated thermodynamic equations based on Pourbaix diagram methods is an outstanding way to model any other corrosion activities.

Cria-se, nesta pesquisa, as ferramentas de estudo de uma alternativa inovadora de irrigação localizada superficial, que consiste na escavação do terreno ao redor da base da planta na forma de um anel grosso que produza bulbos úmidos equivalentes aos gerados por qualquer um gotejador. Estas bacias deverão ser conectadas por meio de sulcos compactados que, além de servir como condutores semi-impermeáveis, criam um micro sistema de coleta de água. Capas radiculares podem ser colocadas dentro das bacias com o intuito de eliminar as perdas por evaporação, evitar o crescimento de ervas daninhas e até incrementar o rendimento da colheita. Desenvolve-se para este fim um modelo matemático misto do tipo balanço volumétrico e onda cinemática modificado com a teoria de onda de choque, que utiliza um modelo de infiltração baseada na inédita aplicação do princípio da maximização da entropia multidirecional. Este novo modelo de infiltração em comparação com os modelos de Horton, Philips e Kostiakov determina, além de menores erros padrões, maiores coeficientes de correlação, em média de 1.2% e 8.9 % e máximos de 2.5% e 68% nos infiltrômetros por sulcos e anel duplo, respectivamente. / The doctorate research creates the tools for study a new alternative of localized superficial irrigation. The system purposed consists in a ground excavation around the plant base. The form of this is same as a big ring, that produces an humid bulb in the root zone equivalent to a drooping system. This cavities need to be connected by furrows that\'s beyond serves for being a semi impermeable conductor of water creates a micro-system of water harvesting. Root layers can be placed inside of the cavities with intention to eliminate the losses for evaporation, to prevent the growth of harmful grass and until to improve the collect income. For this ending development a modify volumetric balance and cinematic wave model that incorporated a new infiltration model. This infiltration model is based in the in edit maximization of the multidirectional entropy. Comparing the new entropic model with the models of Horton, Philips and the modified model of Kostiakov, the entropic one, it was determined a lesser standard error and a bigger correlation coefficient, in average of 1.2% and 8.9 % for the furrows and double ring infiltrometers respectively and a maximum of 2.5% and 68%.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18979号 / 工博第4021号 / 新制||工||1619(附属図書館) / 31930 / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 鈴木 基史, 教授 木村 健二, 教授 蓮尾 昌裕 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No description available.

No description available.

No description available.