Déficits na regulação serotoninérgica dos circuitos catecolaminérgicos tem sido propostos como um mecanismo relacionado à etiologia dos transtornos de humor. Projeções do núcleo mediano da rafe (MnR) modulam a atividade dopaminérgica no prosencéfalo e são também parte de um sistema de inibição/desinibição comportamental que se assemelha às variações nos níveis de atividade apresentados durante os polos do transtorno bipolar. O objetivo do presente estudo foi avaliar se as alterações comportamentais induzidas pela inativação do MnR podem ser um modelo animal para estudo da mania humana. No Capítulo I, o procedimento de lesão eletrolítica do MnR foi realizado em ratos Wistar machos, tendo como controles os grupos lesão fictícia e intacto. Os resultados confirmaram a capacidade desta manipulação experimental em reproduzir hiperatividade e estereotipia crônicas, aumento na frequência de respostas positivamente reforçadas por solução de sacarose e padrão comportamental de dominância social. Ainda, foi demonstrada a potencialidade do tratamento crônico com lítio em reduzir a hiperatividade. No Capítulo II foram realizadas lesões eletrolíticas do MnR em camundongos C57BL/6J machos, tendo novamente como controles os grupos lesão fictícia e intacto. Os resultados demonstraram desenvolvimento de hiperatividade, estereotipia e maior frequência de exposição a situações aversivas/de risco nos testes do labirinto em cruz elevado e do claro/escuro. O tratamento crônico com lítio atenuou ou reverteu parte destas alterações comportamentais. Análises do tecido encefálico demonstraram níveis terapêuticos equivalentes de LiCl em todos os grupos submetidos ao tratamento e a histologia confirmou o sítio de lesão. O conjunto dos dados obtidos sugere a adequação do modelo proposto pelo atendimento aos critérios de validade de face e preditiva apresentando como vantagens a mimetização de diversos sintomas do transtorno e a cronicidade destes. Ainda, a reprodutibilidade dos efeitos da lesão em diferentes espécies sugere a existência de homologia evolutiva, acrescentando fundamentos à validade de constructo hipotetizada. Por fim, destaca-se que este modelo de mania parece ser heurístico pela possibilidade de contribuir para a investigação dos mecanismos de ação do lítio e para a compreensão das relações de oposição entre os sistemas neurotransmissores excitatórios e inibitórios como parte da neurobiologia dos transtornos de humor / Deficits in serotoninergic regulation of catecholaminergic circuits have been proposed as a mechanism related to the etiology of mood disorders. Projections from the median raphe nucleus (MnR) modulate the dopaminergic activity in the forebrain and are also part of a behavioral disinhibition/inhibition system that resembles the variations in activity levels shown during the poles of bipolar disorder. The aim of the present study was to evaluate if the behavioral effects induced by the inactivation of the MnR can be considered an animal model for studying the human mania. In Chapter I, the MnR electrolytic lesion was performed in male Wistar rats, having as control groups sham operated and intact animals. The results confirmed the capacity of this experimental manipulation to reproduce chronic hyperactivity and stereotypy, increased response frequency positively reinforced by sucrose solution and a social dominant behavioral pattern. Furthermore, it was shown the potentiality of the lithium treatment in reducing the hyperactivity. In Chapter II MnR electrolytic lesions were performed in C57BL/6J mice, having as control groups sham operated and intact animals. The results demonstrated the development of hyperactivity, stereotypy and increased frequency of exposure to aversive situations/\"risk taking\" in the elevated plus maze and light/dark box tests. Chronic treatment with lithium attenuated or reversed some of these behavioral alterations. Encephalic tissue analysis showed equivalent lithium therapeutic levels in all treated groups and the histology confirmed the lesion site. The set of data obtained suggests the suitability of the proposed model for attending criteria for face and predictive validities presenting advantages such as the mimicking of several disorder symptoms and the chronicity of them. Also, the reproducibility of the effects of the lesion in different species suggests the existence of evolutionary homology and adds basis to the construct validity hypothesized. Finally, it is emphasized that this model of mania seems to be heuristic by the possibility to contribute to the investigation of lithium mechanisms of action and for understanding the opposite relations between excitatory and inhibitory neurotransmitter systems as part of the neurobiology of mood disorders

Déficits na regulação serotoninérgica dos circuitos catecolaminérgicos tem sido propostos como um mecanismo relacionado à etiologia dos transtornos de humor. Projeções do núcleo mediano da rafe (MnR) modulam a atividade dopaminérgica no prosencéfalo e são também parte de um sistema de inibição/desinibição comportamental que se assemelha às variações nos níveis de atividade apresentados durante os polos do transtorno bipolar. O objetivo do presente estudo foi avaliar se as alterações comportamentais induzidas pela inativação do MnR podem ser um modelo animal para estudo da mania humana. No Capítulo I, o procedimento de lesão eletrolítica do MnR foi realizado em ratos Wistar machos, tendo como controles os grupos lesão fictícia e intacto. Os resultados confirmaram a capacidade desta manipulação experimental em reproduzir hiperatividade e estereotipia crônicas, aumento na frequência de respostas positivamente reforçadas por solução de sacarose e padrão comportamental de dominância social. Ainda, foi demonstrada a potencialidade do tratamento crônico com lítio em reduzir a hiperatividade. No Capítulo II foram realizadas lesões eletrolíticas do MnR em camundongos C57BL/6J machos, tendo novamente como controles os grupos lesão fictícia e intacto. Os resultados demonstraram desenvolvimento de hiperatividade, estereotipia e maior frequência de exposição a situações aversivas/de risco nos testes do labirinto em cruz elevado e do claro/escuro. O tratamento crônico com lítio atenuou ou reverteu parte destas alterações comportamentais. Análises do tecido encefálico demonstraram níveis terapêuticos equivalentes de LiCl em todos os grupos submetidos ao tratamento e a histologia confirmou o sítio de lesão. O conjunto dos dados obtidos sugere a adequação do modelo proposto pelo atendimento aos critérios de validade de face e preditiva apresentando como vantagens a mimetização de diversos sintomas do transtorno e a cronicidade destes. Ainda, a reprodutibilidade dos efeitos da lesão em diferentes espécies sugere a existência de homologia evolutiva, acrescentando fundamentos à validade de constructo hipotetizada. Por fim, destaca-se que este modelo de mania parece ser heurístico pela possibilidade de contribuir para a investigação dos mecanismos de ação do lítio e para a compreensão das relações de oposição entre os sistemas neurotransmissores excitatórios e inibitórios como parte da neurobiologia dos transtornos de humor / Deficits in serotoninergic regulation of catecholaminergic circuits have been proposed as a mechanism related to the etiology of mood disorders. Projections from the median raphe nucleus (MnR) modulate the dopaminergic activity in the forebrain and are also part of a behavioral disinhibition/inhibition system that resembles the variations in activity levels shown during the poles of bipolar disorder. The aim of the present study was to evaluate if the behavioral effects induced by the inactivation of the MnR can be considered an animal model for studying the human mania. In Chapter I, the MnR electrolytic lesion was performed in male Wistar rats, having as control groups sham operated and intact animals. The results confirmed the capacity of this experimental manipulation to reproduce chronic hyperactivity and stereotypy, increased response frequency positively reinforced by sucrose solution and a social dominant behavioral pattern. Furthermore, it was shown the potentiality of the lithium treatment in reducing the hyperactivity. In Chapter II MnR electrolytic lesions were performed in C57BL/6J mice, having as control groups sham operated and intact animals. The results demonstrated the development of hyperactivity, stereotypy and increased frequency of exposure to aversive situations/\"risk taking\" in the elevated plus maze and light/dark box tests. Chronic treatment with lithium attenuated or reversed some of these behavioral alterations. Encephalic tissue analysis showed equivalent lithium therapeutic levels in all treated groups and the histology confirmed the lesion site. The set of data obtained suggests the suitability of the proposed model for attending criteria for face and predictive validities presenting advantages such as the mimicking of several disorder symptoms and the chronicity of them. Also, the reproducibility of the effects of the lesion in different species suggests the existence of evolutionary homology and adds basis to the construct validity hypothesized. Finally, it is emphasized that this model of mania seems to be heuristic by the possibility to contribute to the investigation of lithium mechanisms of action and for understanding the opposite relations between excitatory and inhibitory neurotransmitter systems as part of the neurobiology of mood disorders

Les mousses métalliques synthétisées par plasma électrolytique et leur mise en forme développées au CEA présentent certains problèmes de tenue mécanique, d’homogénéité en structure et en densité, et leur porosité n’est pas encore maîtrisée. L’objectif de cette thèse est de comprendre et d’apporter des solutions à ces difficultés rencontrées lors des différentes étapes de la synthèse. Ainsi, la thèse porte sur l’étude du système dans son ensemble pour maîtriser à la fois le procédé et la structure des mousses formées.La compréhension du plasma et de son implication dans la formation de mousses métalliques passe par celle de trois phénomènes principaux : la formation de la bulle de gaz, la formation et la propagation des décharges électriques et le transfert de charges, qui conditionnent chacun la structure finale des mousses. En premier lieu, la formation et l’évolution de la bulle gazeuse ont été observées et des modifications du procédé ont permis de maîtriser cette bulle. Ensuite, l’étude des propriétés et caractéristiques physiques des mousses d’or a été réalisée en synthétisant des mousses à partir de paramètres expérimentaux variables, puis leurs propriétés physiques et structurelles ont été mesurées. L’ensemble des expériences réalisées a permis d’établir un modèle phénoménologique qui rend compte des différents mécanismes impliqués dans la formation et la croissance des brins de mousse. Différentes expérimentations menées directement sur les décharges puis sur le système dans sa globalité ont vérifié partiellement ces hypothèses. / Some troubles are noticed on the metallic foams synthesized by an electrolytic plasma process and on the way they are manufactured. Those foams present a poor mechanical resistance, their structure is lacking of homogeneity and their porosity is far from being controlled. This PhD work aims at understanding and bringing solutions to those problems for each step of the process. Thus the whole process is studied in order to control both the experimental process and the foams structure.The plasma comprehension and especially its contribution in the metallic foams formation is driven through three main phenomena: the gaseous bubble formation, the sparks formation and propagation, and the charge transfer. Each one is playing a role on the final foam structure. First, the formation of the gaseous bubble and its evolution were observed, and then the process was modified to control the bubble. Second, foams were synthesized with different process parameters and their characteristics were studied in order to highlight their influences. All those experiments led to the creation of a phenomenological model which goal is to explain the different mechanisms involved in the foam strands growth. Several experiments were carried out, some on the sparks, others on the whole system, and the hypotheses were partially proved.

Porous carbons are versatile materials with applications in different fields. They are used in filtration, separation and sequestration of fluids and gases, as conductive additives in many energy storage materials, as coloring agents, as pharmaceutical and food additives, and in many other vital technologies. Porous carbons produced by pyrolysis and activation of organic precursors commonly suffer from poorly controlled morphology, microstructure, chemistry, and pore structure. In addition, the poorly controlled parameters of porous carbons make it challenging to elucidate the underlying key physical parameters controlling their performance in energy storage devices, including electrochemical capacitors (ECs) and lead-acid batteries (LABs). Zeolite-templated carbons (ZTCs) are a novel class of porous carbon materials with uniform and controllable pore size, microstructure, morphology, and chemistry. In spite of their attractive properties, they have never been explored for use in LABs and their studies for ECs have been very limited. Here I report a systematic study of ZTCs applications in ECs operating at temperatures as low as - 70 C and in LABs. Greatly improved power and energy performance, compared to state of the art devices, has been demonstrated in the investigated ECs. Moreover, the application of ZTCs in LABs has resulted in a dramatic enhancement of their cycle life and power and energy densities.

Neural networks were applied to the analysis of electrochemical noise data. Electrochemical noise is defined as the fluctuations in either current or potential with time for a metal which is immersed in a conductive solution. This data is of interest because of its relationship to particular corrosion processes. Specifically, a system which is experiencing uniform corrosion will produce a different noise signal than one which is experiencing localized (perforation) corrosion. The economic effects of corrosion are significant and methods which improve the ability to detect, measure and predict corrosion would be extremely valuable.Two series of experiments were conducted. The data for both series were collected from aluminum samples immersed in various aqueous solutions. The series differed from each other in the configuration and programming of the potentiostat which collected the data. The first series only dealt with potential noise while the second series dealt with both potential and current noise. Auxiliary parameters, such as the pH and chloride concentration of the solutions were used in the second series. The first series studied data from only two solutions, while the second series included six solutions.It was possible for neural networks to correctly categorize systems in Series 1 according to the class of corrosion being observed (uniform or perforating). Appropriate data transformation steps were required to effect these classifications and it was also observed that many of these data transformations would lead directly to categorization without the use of a neural network.The additional data collected in Series 2 allowed a more complex analysis. Neural networks were able to simultaneously predict both the propensity towards localized corrosion and the metal dissolution rate. This application demonstrated the power of neural networks.Several types of neural networks and learning algorithms were included in this study. The two systems used most were a backpropagation (multi-layer perceptron) and a radial basis system. Comparisons of the various network systems with regard to speed and accuracy were made. / Department of Mathematical Sciences

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 78-86). Also available on the World Wide Web.

Thesis (Ph.D.) - University of St Andrews, April 2007.

Thesis (M. S.)--Materials Science and Engineering, Georgia Institute of Technology, 2005. / Ready, Jud, Committee Co-Chair ; Carter, Brent, Committee Co-Chair ; Snyder, Bob, Committee Member ; Wang, Zhong Lin, Committee Member. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:23:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-28Bitstream added on 2014-06-13T20:30:13Z : No. of bitstreams: 1 antonio_ca_me_bauru.pdf: 1720399 bytes, checksum: 396bef6efc3f71eb7d1f9f3cad7c2279 (MD5) / Apesar da excelente relação resitência/peso das ligas de alumínio, a aplicação tecnológica destas ligas é limitada pela baixa resistência ao desgaste. Neste trabalho, amostras de uma liga de alumínio (AA 5052) foram tratadas pelo processo de oxidação por plasma eletrolítico, com tempo de exposição variando de 150 a 900 s. A composição e a estrutura química dos revestimentos assim produzidos foram analisadas por espectroscopia de absorção no infravermelho. Um método baseado na medida de correntes parasitas e a perfilometria foram usados, respectivamente, na determinação da espessura e da rugosidade das camadas depositadas. O revestimento formado porssui espessura de até 9,2um. Análises da morfologia dos revestimentos foram feitas com microscopia eletrônica de varredura enquanto a resistência a desgastte das superfícies foi avaliada com um sistema pino-sobre-disco. Os resultados revelaram a deposição de um revestimento cerâmico, que conferiu expressivo aumento à resistência a desgaste da liga, o qual mostrou que as amostras tratadas suportaram uma carga aplicada de 13,44 vezes em comparação com amostras sem tratamento / Despiste the excellent strengh/weight ratio, technological applications of aluminum aloys are limited by their low wear resistance. In this work, samples of AA 5052 aluminum alloy have been modified by plasma electrolytic oxidation, with exposure time ranging from 150 s to 900 soconds. Compositional characterization has been performed by fourier transform infrared spectroscopy. Eddy current and profilometry have been used, respectively, to evaluate thickness and roughness of the deposited layers. The coating formed has a thickness of up to 9,2 micrometers. Morphological investigations have been performed with scanning electron microscopy while wear resitance has been assessed using a pin-on-disk devide. The results have revealed the deposition of ceramic layers with significant enhancement of wear resistance, which showed that the treated samples resistance, which showed that the treated samples resist an applied load 13.44 times more compared with untreated samples

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-20T14:16:36Z No. of bitstreams: 1 DEYDEBY ILLAN DOS SANTOS PEREIRA - DISSERTAÇÃO PPGEQ 2015.pdf: 1980068 bytes, checksum: 34bbeba76537ef3576d5c38716ffa473 (MD5) / Made available in DSpace on 2018-03-20T14:16:36Z (GMT). No. of bitstreams: 1 DEYDEBY ILLAN DOS SANTOS PEREIRA - DISSERTAÇÃO PPGEQ 2015.pdf: 1980068 bytes, checksum: 34bbeba76537ef3576d5c38716ffa473 (MD5) Previous issue date: 2015-03-17 / Capes / A produção de gases poluentes está ligada diretamente ao grande consumo dos combustíveis fósseis. O meio ambiente já vem dando sinais de desgaste, enquanto que eles continuam sendo de extrema importância para a economia global. Os danos causados pelo aquecimento global, juntamente com a crescente preocupação com a diminuição dos níveis das reservas mundiais de combustíveis fósseis e à crescente demanda global energética motivam os estudos sobre a produção de hidrogênio por ele apresentar-se com um grande vetor energético. Geralmente, os processos básicos para a produção de hidrogênio a partir de fontes primárias de energia são: a eletrólise da água; processos termoquímicos e também processos biológicos. A eletrólise, apesar de ser promissora, ainda precisa de uma quantidade considerável de energia. Por isso, pesquisas devem ser desenvolvidas para tornar o H2, de fato, um vetor energético. Foi seguindo esta perspectiva que o presente trabalho teve como objetivo avaliar um reator eletrolítico bipolar constituído por eletrodos porosos de níquel para produção de H2. No reator estudado foram utilizados eletrodos porosos compostos por placas de aço (1020 niqueladas) e esponjas porosas de níquel soldadas na área eletrolítica. Com a caraterização do reator foi constatado que ele teve um desempenho superior a um reator compostos por eletrodos de aço niquelado operando nas mesmas condições de tensão e concentração do eletrólito. O fluxo de H2 produzido nos eletrodos lisos com solução de KOH a (20 e 25) % foram (0,042 e 0,043) L/(h.cm2), respectivamente. Já o fluxo de H2 dos eletrodos porosos de níquel com solução de KOH a (20 e 25) % foram (0,087 e 0,122) L/(h.cm2), respectivamente. Com este fato foi constatado que com a mesma área eletrolítica produziu-se mais que o dobro e, praticamente, o triplo de H2 com os eletrodos porosos de níquel operando com solução de KOH a (20 e 25) %, respectivamente, em massa, como eletrólito. Este desempenho provocou uma economia de até 46,69 % na energia consumida para produzir 1,0 m3 de H2. Diante dos resultados obtidos com o reator, o eletrodo poroso de níquel mostrou ser excelente para ser empregado no processo de produção de hidrogênio por torná-lo mais eficaz e viável. / The production of gaseous pollutants is linked directly to the large consumption of fossil fuels. The environment is already showing signs of wear, while they are still being extremely important for the global economy. The damage caused by global warming, along with the growing concern about the decreased levels of world reserves of fossil fuels and the growing demand energetic global, motivate studies on the production of hydrogen by him introduce yourself how with a large energy vector. Generally, the basic processes for producing hydrogen from the primary energy sources are: the electrolysis of water; thermochemical processes and also biological processes. The electrolysis; despite being promising; still needs a considerable amount of energy. That is why; researches should be developed to make the H2, indeed, an energy vector. Was following this perspective that the present work aimed to evaluate a bipolar electrolytic reactor composed by electrodes porous the nickel for H2 production. On the reactor studied were used porous electrodes compounds steel of plates (nickel-1020) and sponges porous of nickel welded in the electrolyte area. With the characterization of the reactor was found that he had a superior performance at a reactor composed of steel electrodes nickel plated operating under the same conditions of tension and concentration of the electrolyte. The H2 flow produced in flat electrodes with KOH solution (20 and 25) % were (0,042 and 0,043) L/(h.cm2), respectively. Already the H2 flow of the nickel porous electrode with solution of KOH (20 and 25) % were (0,087 and 0,122) L/(h.cm2), respectively. With this fact it was found that with the same electrolytic area was produced more than the dobro and, practically; triple the H2 with electrodes porous of nickel operating with KOH solution (20 and 25) %; respectively; by mass; as electrolyte. This performance led to savings of up to 46,69 % in energy consumed to produce 1,0 m3 of H2. Based on the results with the reactor, the electrode porous of nickel was shown to be excellent to be employed in the hydrogen production process by making it more effective and viable.