Cette thèse porte principalement sur la caractérisation électrique et la modélisation physique d'éléments mémoires émergents de type OxRRAM (Oxide Resistive Random Access Memory) intégrant soit un oxyde de nickel, soit un oxyde de hafnium. Une fois la maturité technologique atteinte, ce concept de mémoire est susceptible de remplacer la technologie Flash qui fait encore figure de référence. Les principaux avantages de la technologie OxRRAM reposent sur une très bonne compatibilité avec les filières CMOS, un faible nombre d'étapes de fabrication, une grande densité d'intégration et des performances attractives en termes de fonctionnement. Le premier objectif de ce travail concerne le diélectrique employé dans les cellules. Il s'agit d'apporter des éléments factuels permettant d'orienter un choix technologique sur la méthode d'élaboration de l'oxyde de nickel (oxydation thermique ou pulvérisation cathodique réactive) puis d'évaluer les performances de cellules à base d'oyxde de hafnium. Le second objectif est d'approfondir la compréhension des mécanismes physiques responsables du changement de résistance des dispositifs mémoire par une approche de modélisation physique des phénomènes opérant lors des phases d'écriture et d'effacement, sujet encore largement débattu dans la communauté scientifique. Le troisième objectif de cette thèse est d'évaluer, par le biais de caractérisations électriques, les phénomènes parasites intervenant dans les éléments mémoires de type 1R (élément résistif sans dispositif d'adressage) et, en particulier, la décharge capacitive apparaissant lors de leur programmation (opérations d'écriture). / This work is focused on the electrical characterization and physical modeling of emerging OxRRAM memories (Oxide Resistive Random Access Memory) integrating nickel or hafnium oxide. After reaching maturity, this memory concept is likely to replace the Flash technology which is still a standard in the CMOS industry. The main advantages of resistive memories technology is their good compatibility with CMOS processes, a small number of manufacturing steps, a high integration density and their attractive performances in terms of memory operation. The first objective of this thesis is to provide enough informations allowing to orientate the elaboration process of the active nickel oxide layer (thermal oxidation, reactive sputtering) then to compare the performances of the fabricated cells with devices featuring a hafnium oxide layer. The second objective is to understand the physical mechanisms responsible of the device resistance change. A physical model is proposed allowing to apprehend SET and RESET phenomenon in memory devices, subject which is still widely debated in the scientific community. The third objective of this thesis is to evaluate electrical parasitic phenomenon observed in 1R-type memory elements (resistive element without addressing device), in particular the parasitic capacitance appearing during cell programming (writing operation).

Les composés électrochomes changent de couleur en fonction d'une tension qui leur est appliquée. La tenue en cyclage de couches minces à base de NiO, électrochrome cathodique, dépend fortement de la température et de la pression de dépôt. D’autre part la proportion de phase électrochimiquement active dépend fortement de l’épaisseur des couches. Selon le modèle proposé NiO en milieu KOH se transforme en hydroxyde de nickel Ni(OH)2 puis dans la phase de coloration en oxyhydroxyde NiOOH avant de revenir à sa forme réduite durant la phase décoloration. À la fin de ce cycle, des traces de phase colorée persistent. Nous avons développé des nouvelles méthodes numériques d’analyse des spectres d'absorption de rayons X, caractérisant la structure locale autour du nickel dans ces phases non cristallisées, afin de déterminer les concentrations des diverses espèces au cours du cycle. Aucune des méthodes habituellement pratiquées, comme la combinaison linéaire d’espèces modèles par la méthode des moindres carrés linéaire, et la méthode d’Analyse en Composantes Principales, ne sont adaptées aux cas de spectres fortement corrélés comme les oxydes-hydroxydes de nickel. Nous montrons qu’il est possible d’améliorer la méthode des moindres carrés en utilisant un algorithme original : « la méthode des Moindres Carrés Linéaire Progressive ». La base de cette méthode est fondée sur l’étude statistique des erreurs et corrélations. Ce travail a permis de valider le modèle électrochimique et d’évaluer pour la première fois la concentration en NiOOH dans la phase réduite, signature de l'irréversibilité. Seule, la présence avant cyclage de Ni(OH)2 dans les films de NiO n'a pu être expliquée / Electrochromic materials change their color versus an applied electric voltage. The electrochemical study of NiO thin films, which are cathodic electromic materials, shows an important oxidationreduction cycles lifetime dependance on thin films deposition temperature and pressure. The proportion of electrochemically active material depends on the film thickness. The proposed model suggests that in KOH NiO is transformed first to nickel hydroxide Ni(OH)2, and to nickel oxihydroxide in the coloration process, before returning to Ni(OH)2 in the decoloration step. At the end of the cycle, traces of the colored phase are still observed. We have developed a new X-Ray absorption spectroscopy numerical analysis method in order to characterize the concentration of each species present in these non crystalline materials. Mixed Ni oxides and hydroxides XAS spectra are highly correlated and Linear Least Squares and Principal Component Analysis methods proved to be totally inefficient. In order to improve the linear least squares method, we have developed a home-made algorithm named « Progressive Linear Least Squares method ». This method is based on the use of statistical errors and correlations evaluation of the spectra. It was then possible to valid the electrochemical model and to evaluate for the first time the concentration of residual NiOOH in the reduced thin film phases, related to the irreversibility of the electrochromic process. However, we were unable to explain the presence of a small amount of de Ni(OH)2 in the NiO films prepared at room temperature, prior to any electrochemical treatment

Made available in DSpace on 2015-04-14T13:47:29Z (GMT). No. of bitstreams: 1 431084.pdf: 3726416 bytes, checksum: a4fb68eb9b35d31a45ba72acfa859978 (MD5) Previous issue date: 2011-03-31 / O objeto desta pesquisa foi a miss?o de San Francisco de Borja, erigida em 1682. A proposta deste trabalho constituiu em sugerir uma carta de potencial arqueol?gico para a moderna cidade de S?o Borja/RS. Para isso, buscou-se verificar a distribui??o espacial da malha urbana atual sobreposta a antiga malha reducional. Observando os modelos coloniais para a instala??o de cidades europ?ias, e ainda os padr?es seguidos para erigir as Redu??es Jesu?ticas, procurou-se compreender a utiliza??o do lugar, tendo como base factual ? pesquisa: documentos hist?ricos escritos, iconogr?ficos, arquitet?nicos e arqueol?gicos. Todas as fontes fornecem informa??es para o entendimento da distribui??o espacial da redu??o de San Francisco de Borja, demonstrando a estreita rela??o entre a miss?o jesu?tica e a atual cidade. Pois a cidade seguiu o mesmo tra?ado da antiga miss?o.

Made available in DSpace on 2016-04-04T18:22:01Z (GMT). No. of bitstreams: 1 Dirceu Piccinato Junior .pdf: 18445166 bytes, checksum: b6f0a1aa40fb3428e66bcb669e6f5346 (MD5) Previous issue date: 2012-02-24 / This paper seeks to trace a historical analysis of urban land ownership, land heritage (religious and secular) in the training process and the establishment of urban centers in northeastern S?o Paulo State between the years 1800 and 1930, focusing more attention to two significant events that favored the construction of an urban network in this region: the migration of incoming miners and the cycle of coffee along with the arrival of Cia Mogiana these parts. The establishment of an urban center it is a chapel, parish and village was only possible during the Colony and the Empire, by granting lands to the heritage of a holy devotion. With the advent of the Republic, on the actions of capitalist interests, the donation of land was no longer the sacred as well, but the commercialization of land, or profit. The scrutiny as to how the appointments issued by each of the two historical dimensions conform sought the transformation of this part of the state territory and the creation of urban forms. We shall show, however, that even calling for a linearity in the award process, and ownership of urban design, practices, experiences and local dynamics were crucial to the definition of the nuclei. For the preparation of the dissertation, have been included relevant documents and images of urban farming initiatives, as well as important previous studies, to identify possible links between the issues surrounding land and property circumstances that presented themselves in every situation and the determinations imposed by government religious and / or civil liability. Thus, we try to treat the grant of land as an urban process developed in a regional context that holds conjunctures of conflicts and interests in configuration of urban. / Este trabalho busca tra?ar uma an?lise hist?rica sobre a apropria??o da terra urbana, patrim?nio fundi?rio (religioso e laico) no processo de forma??o e funda??o de n?cleos urbanos no nordeste do Estado de S?o Paulo entre os anos de 1800 e 1930, detendo-se com maior aten??o em dois momentos significativos que favoreceram a constru??o de uma rede urbana nesta regi?o: o movimento migrat?rio dos entrantes mineiros e o ciclo da cafeicultura, juntamente com a chegada da Cia. Mogiana nestas paragens. O estabelecimento de um n?cleo urbano, seja ele uma capela, freguesia ou vila, s? era poss?vel, durante a Col?nia e o Imp?rio, por meio da concess?o de terras para o patrim?nio de um santo de devo??o. Com o advento da Rep?blica, sob as a??es dos interesses capitalistas, a doa??o de terra para a forma??o de n?cleos urbanos n?o tinha mais como bem o sagrado, mas a comercializa??o da terra, ou seja, o lucro. A an?lise atenta para o modo como as designa??es emanadas por cada uma das dimens?es hist?ricas procuraram conformar a transforma??o desta parte do territ?rio paulista e a cria??o das formas urbanas. Pretende-se mostrar, entretanto, que mesmo conclamada uma linearidade no processo de concess?o, apropria??o e delineamento do solo urbano, pr?ticas, experi?ncias e din?micas locais foram determinantes para a defini??o dos n?cleos urbanos. Para a elabora??o da disserta??o, foram consultados documentos escritos e imagens pertinentes a iniciativas das cria??es urbanas, bem como importantes estudos precedentes, procurando identificar poss?veis v?nculos entre as quest?es envolvendo as terras patrimoniais, circunst?ncias que se apresentavam em cada situa??o e as determina??es impostas pelas administra??es religiosa e/ou civil. Desse modo, procura-se tratar a concess?o da terra urbana como um processo desenvolvido num contexto regional que guarda conjunturas particulares de conflitos e interesses na configura??o do urbano.

Impulsionados pela busca de fontes limpas de energia, surgem os processos de combustao com recirculacao quimica (CLC), e reforma com recirculacao quimica (CLR). CLC e CLR sao processos quimicos para oxidacao de hidrocarbonetos gasosos. E utilizada a acao de transportadores de oxigenio (TO), para transferir oxigenio do ar para o combustivel (neste caso o metano), evitando-se o contato direto entre ar atmosferico e metano por diversos motivos. Os TOs, compostos por oxidos metalicos na forma de po fino, circulam continuamente entre dois reatores de leito fluidizado (reator de ar e de combustivel), sofrendo sucessivos ciclos de reducao e oxidacao. Os processos se diferenciam com relacao aos produtos, em CLC objetiva-se a geracao de energia, atraves da oxidacao completa do combustivel, resultando em uma mistura de CO2 e H2O, podendo ser facilmente separada por condensacao. No caso do CLR a oxidacao ocorre de maneira parcial, dando origem a uma mistura de gas de sintese (H2 + CO). O CLC apresenta vantagens com relacao aos processos tradicionais de captura de CO2, pois nao se faz necessaria a utilizacao de processos secundarios para separacao gasosa, economizando assim energia, alem do fato de nao gerar gases do tipo NOx. O presente trabalho apresenta a preparacao de duas series de materiais, via impregnacao seca, uma com composicao 2, 4 e 8% m/m de oxido de niquel e outra com os mesmo teores de oxido de niobio, suportados sobre alumina comercial de alta area superficial especifica. Os materiais foram caracterizados pelas tecnicas de picnometria a helio, volumetria de nitrogenio, porosimetria por intrusao de mercurio, DRX, MEV, TPR 5%H2/N2 analisado com TCD em ChemBet, TPR 5%CH4/Ar e TPO 5%O2/Ar sendo a variacao de massa analisada em termobalanca (TGA/DSC), alem de se utilizar de espectrometria de massas para analise dos gases gerados. Os diferentes transportadores de oxigenio foram testados em reator de leito fixo, sendo avaliados em diferentes condicoes experimentais tais como: temperaturas de operacao, vazoes de reagentes gasosos, concentracoes de metano, adicao de CO2 e H2O ao combustivel. Os produtos da reacao no reator de leito fixo foram analisados por cromatografia gasosa e espectrometria de massa. Os resultados mostraram que; o deposito de carbono sobre o catalisador pode ser drasticamente reduzido com a adicao de mistura oxidante junto ao combustivel e que estes oxidos estudados tem potencial aplicacao industrial, mostrando-se seletivos para reforma do metano com consecutiva producao de gas de sintese. / Driven by the demand for clean energy sources, arise chemical-looping combustion - CLC, and chemical-looping reforming - CLR. CLC and CLR are chemical processes for oxidation of gaseous hydrocarbons. Both of them use the action of catalysts, here called oxygen carriers (OC), which transfers oxygen from the air to the fuel (in this case methane), avoiding the direct contact between the two gases for various reasons. The OC\'s are composed of metal oxides in the form of fine power, circle continuously between two fluidized bed reactors (fuel reactor and air reactor), suffering successive cycles of reduction and oxidation. The two processes differ in relation to the products; the aim of CLC is generation of energy (heat), through the complete oxidation of the fuel, resulting in a mixture of CO2 and H2O, which can be easily separated by condensation. In the case of CLR, the oxidation occurs partially, resulting in synthesis gas, a mixture of H2 and CO. The CLC processes shows advantages when compared to other traditional processes for capture of CO2, because it is not necessary to use secondary processes for gas separation, saving energy, besides the fact of no NOx is generated. This work describes the preparation of two series of materials via dry impregnation, which are composed of 2, 4 and 8% w/w niobium oxide or nickel oxide, supported on commercial alumina, with high specific surface area. The materials were characterized by the techniques of helium pycnometry, nitrogen volumetry, mercury intrusion porosimetry, DRX, MEV, TPR 5% H2/N2 analyzed with TCD in ChemBet, TPR 5% CH4/Ar and TPO 5% O2/Ar, being the changes in mass and heat analyzed in a thermogravimetric balance (TGA/DSC) coupled to a mass spectrometer permitting the analysis of the generated gases. The different oxygen carriers were tested in a fixed bed reactor, evaluated in different experimental conditions, such as operation temperature, flow rate of gaseous reactants, methane concentrations, addition of CO2 and H2O to the fuel. The products of the reaction in the fixed bed reactor were analyzed by gas chromatography and mass spectrometry. The results show that: the carbon deposits over the catalysts can be drastically reduced by addition of oxidizing mixture together to the fuel and these studied oxides have a potential industrial application, showing selectivity to reforming of methane with consecutive synthesis gas production.

Submitted by Fernanda Ciolfi (fernanda.ciolfi@puc-campinas.edu.br) on 2016-04-12T18:59:04Z No. of bitstreams: 1 Helena Vilela Santos.pdf: 185088901 bytes, checksum: 96f6ef340d42f763ad6d86313f268247 (MD5) / Made available in DSpace on 2016-04-12T18:59:04Z (GMT). No. of bitstreams: 1 Helena Vilela Santos.pdf: 185088901 bytes, checksum: 96f6ef340d42f763ad6d86313f268247 (MD5) Previous issue date: 2016-02-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This study aims to investigate public spaces located in the downtown of Barra Mansa, Rio de Janeiro, by engaging an analysis of the transformations occurred over the past (include your time cut) years. This dissertation's goal is (1) to discuss preservation policies in use in Brazil and in Cuba, (2) to theorize over public spaces and urban ensembles? protection of heritage values and (3) to study the history and features of use and occupation of theses spaces and their surroundings in order to diagnose the target ensemble and its relation with the city, highlighting how they have been preserved until now. This study uses as data basis analysis of bibliography related to the theme, and fieldworks made in Barra Mansa, RJ and as reference studies about three public spaces, in Santiago de Cuba, that provide information for a comparative analysis of both cities heritage management and preservation. As a result this investigation aspires to build parameters that may contribute to the preservation and rehabilitation of the areas under study and highlight the heritage value of city?s public spaces. / Esta pesquisa busca investigar os espa?os p?blicos localizados no centro de Barra Mansa, Rio de Janeiro, por meio de uma an?lise das transforma??es que ocorreram ao longo dos anos at? o contexto atual. Tem como objetivos: (1) discutir as pol?ticas de preserva??o adotadas no Brasil, (2) discutir a teoria acerca da preserva??o de espa?os p?blicos e conjuntos urbanos de interesse patrimonial(3) estudar a hist?ria e mudan?a do uso e ocupa??o desses espa?os e seus entornos para compreender um conjunto de pra?as , suas rela??es com a cidade,e como tem sido preservado at? o momento. Utiliza como bases de an?lise a bibliografia sobre o tema, pesquisas realizadas em campo na cidade de Barra Mansa e como refer?ncia, estudos realizados sobre tr?s pra?as na Cidade de Santiago de Cuba, estabelecendo um paralelo entre suas a??es de preserva??o e gest?o dos patrim?nios. Como resultado essa pesquisa almeja construir par?metros que possam contribuir com a preserva??o e gest?o das pra?as em estudo e, de forma mais geral, ressaltar o valor patrimonial destes espa?os p?blicos da cidade.

Impulsionados pela busca de fontes limpas de energia, surgem os processos de combustao com recirculacao quimica (CLC), e reforma com recirculacao quimica (CLR). CLC e CLR sao processos quimicos para oxidacao de hidrocarbonetos gasosos. E utilizada a acao de transportadores de oxigenio (TO), para transferir oxigenio do ar para o combustivel (neste caso o metano), evitando-se o contato direto entre ar atmosferico e metano por diversos motivos. Os TOs, compostos por oxidos metalicos na forma de po fino, circulam continuamente entre dois reatores de leito fluidizado (reator de ar e de combustivel), sofrendo sucessivos ciclos de reducao e oxidacao. Os processos se diferenciam com relacao aos produtos, em CLC objetiva-se a geracao de energia, atraves da oxidacao completa do combustivel, resultando em uma mistura de CO2 e H2O, podendo ser facilmente separada por condensacao. No caso do CLR a oxidacao ocorre de maneira parcial, dando origem a uma mistura de gas de sintese (H2 + CO). O CLC apresenta vantagens com relacao aos processos tradicionais de captura de CO2, pois nao se faz necessaria a utilizacao de processos secundarios para separacao gasosa, economizando assim energia, alem do fato de nao gerar gases do tipo NOx. O presente trabalho apresenta a preparacao de duas series de materiais, via impregnacao seca, uma com composicao 2, 4 e 8% m/m de oxido de niquel e outra com os mesmo teores de oxido de niobio, suportados sobre alumina comercial de alta area superficial especifica. Os materiais foram caracterizados pelas tecnicas de picnometria a helio, volumetria de nitrogenio, porosimetria por intrusao de mercurio, DRX, MEV, TPR 5%H2/N2 analisado com TCD em ChemBet, TPR 5%CH4/Ar e TPO 5%O2/Ar sendo a variacao de massa analisada em termobalanca (TGA/DSC), alem de se utilizar de espectrometria de massas para analise dos gases gerados. Os diferentes transportadores de oxigenio foram testados em reator de leito fixo, sendo avaliados em diferentes condicoes experimentais tais como: temperaturas de operacao, vazoes de reagentes gasosos, concentracoes de metano, adicao de CO2 e H2O ao combustivel. Os produtos da reacao no reator de leito fixo foram analisados por cromatografia gasosa e espectrometria de massa. Os resultados mostraram que; o deposito de carbono sobre o catalisador pode ser drasticamente reduzido com a adicao de mistura oxidante junto ao combustivel e que estes oxidos estudados tem potencial aplicacao industrial, mostrando-se seletivos para reforma do metano com consecutiva producao de gas de sintese. / Driven by the demand for clean energy sources, arise chemical-looping combustion - CLC, and chemical-looping reforming - CLR. CLC and CLR are chemical processes for oxidation of gaseous hydrocarbons. Both of them use the action of catalysts, here called oxygen carriers (OC), which transfers oxygen from the air to the fuel (in this case methane), avoiding the direct contact between the two gases for various reasons. The OC\'s are composed of metal oxides in the form of fine power, circle continuously between two fluidized bed reactors (fuel reactor and air reactor), suffering successive cycles of reduction and oxidation. The two processes differ in relation to the products; the aim of CLC is generation of energy (heat), through the complete oxidation of the fuel, resulting in a mixture of CO2 and H2O, which can be easily separated by condensation. In the case of CLR, the oxidation occurs partially, resulting in synthesis gas, a mixture of H2 and CO. The CLC processes shows advantages when compared to other traditional processes for capture of CO2, because it is not necessary to use secondary processes for gas separation, saving energy, besides the fact of no NOx is generated. This work describes the preparation of two series of materials via dry impregnation, which are composed of 2, 4 and 8% w/w niobium oxide or nickel oxide, supported on commercial alumina, with high specific surface area. The materials were characterized by the techniques of helium pycnometry, nitrogen volumetry, mercury intrusion porosimetry, DRX, MEV, TPR 5% H2/N2 analyzed with TCD in ChemBet, TPR 5% CH4/Ar and TPO 5% O2/Ar, being the changes in mass and heat analyzed in a thermogravimetric balance (TGA/DSC) coupled to a mass spectrometer permitting the analysis of the generated gases. The different oxygen carriers were tested in a fixed bed reactor, evaluated in different experimental conditions, such as operation temperature, flow rate of gaseous reactants, methane concentrations, addition of CO2 and H2O to the fuel. The products of the reaction in the fixed bed reactor were analyzed by gas chromatography and mass spectrometry. The results show that: the carbon deposits over the catalysts can be drastically reduced by addition of oxidizing mixture together to the fuel and these studied oxides have a potential industrial application, showing selectivity to reforming of methane with consecutive synthesis gas production.

Made available in DSpace on 2014-12-17T14:09:16Z (GMT). No. of bitstreams: 1 JardelDC_TESE_Parcial.pdf: 1739659 bytes, checksum: 19974b9395e0d9fcb23b07c3997dab2f (MD5) Previous issue date: 2012-07-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The resistance of aluminum and their alloys, to the corrosion phenomenon, in aqueous solutions, is a result of the oxide layer formed. However, the corrosion process in the aluminum alloy is associated with the presence a second phase of particles or the presence of chloride ions which promote the disruption of the oxide layer located producing the corrosion process. On the other hand, the term water produced is used to describe the water after the separation of the oil and gas in API separators. The volumes of produced water arrive around 5 more times to the volume of oil produced. The greatest feature of the water is the presence of numerous pollutants. Due to the increased volume of waste around the world in the current decade, the outcome and the effect of the discharge of produced water on the environment has recently become an important issue of environmental concern where numerous treatments are aimed at reducing these contaminants before disposal. Then, this study aims to investigate the electrochemical corrosion behavior of aluminum alloy 6060 in presence of water produced and the influence of organic components as well as chloride ions, by using the electrochemical techniques of linear polarization. The modification of the passive layer and the likely breakpoints were observed by atomic force microscopy (AFM). In the pit formation potential around -0.4 to -0.8 V/EAg/AgCl was observed that the diffusion of chloride ions occurs via the layer formed with the probable formation of pits. Whereas, at temperatures above 65 ?C, it was observed that the range of potential for thepit formation was -0.4 to -0.5 V/EAg/AgCl. In all reactions, the concentration of Al(OH)3 in the form of a gel was observed / A resistencia do aluminio e suas ligas a corros?o em meio aquoso ? resultado da camada de oxido formada. Entretanto, o processo corrosivo nas ligas de alum?nio esta associado a presen?a de part?culas de segunda fase ou a presen?a de ions cloreto que promovem a ruptura da camada de ?xido produzindo o processo corrosivo localizado. Por outro lado, o termo ?gua produzida ? usado para descrever a ?gua ap?s a sua separa??o do ?leo e g?s nos separadores API. Os volumes de ?gua produzida chegam em m?dia de 5 vezes o volume do ?leo produzido. A maior caracter?stica dessa ?gua ? a presen?a de in?meros contaminantes. Devido ao aumento do volume dos res?duos em todo o mundo na d?cada atual, o desfecho e do efeito da descarga de ?gua produzida sobre o meio ambiente tem recentemente tornar-se uma quest?o importante de preocupa??o ambiental onde in?meros tratamentos s?o destinados a redu??o destes contaminantes antes do descarte. Ent?o, o presente estudo visa investigar o comportamento eletroquimico de corros?o da liga de aluminio 6060 em presen?a de ?gua produzida e a influencia dos componentes organicos assim como dos ions cloreto, atrav?s do uso das tecnicas eletroqu?micas de polariza??o linear. A modifica??o da camada passiva e os prov?veis pontos de ruptura foram observados por microscopia de for?a atomica (AFM). No potencial de forma??o de pit de -0,4 a -0,8 V/EAg/AgCl observa-se que ocorre a difus?o dos ?ons cloreto pela camada formada com prov?vel forma??o de pites. Entretanto, em temperaturas superiores a 65?C observou-se que a faixa de potencial de forma??o de pit foi de -0,4 a -0,5V/ EAg/AgCl. Em todas as rea??es observou-se o aumento na concentra??o de Al(OH)3 sob a forma de um gel / 2020-01-01

Made available in DSpace on 2014-12-17T14:36:12Z (GMT). No. of bitstreams: 1 CarleyRA_TESE.pdf: 89405 bytes, checksum: 15f862f15d941a539379fe8f3ce72896 (MD5) Previous issue date: 2010-12-21 / The Novena of St. Anthony in Pradoso, is an annual celebration that takes place between June 1 and June 13. Since its preparation to the conclusion of the celebration are employed traditional knowledges and techniques, which are shared by the community. Such knowledges, built over generations, associated with popular religion, form it into the educational processes that build, through orality, practices and experiences of everyday life, the sense of belonging. An analysis of scenes, knowledges and subjects involved in the celebration, shows the form and content of practices capable of building symbolic territories of belonging. Thus, the Novena of St. Anthony in Pradoso, while an human territoriality, is designed as a locus of learning of belonging, reaffirming community values such as solidarity, service, brotherhood, integration, among others. While empirical reference for an analysis of the importance of belonging, the Novena of St. Anthony in Pradoso, offers subsidies for the production of knowledge, focused on understanding the need for a reconnection of technical and humanistic knowledges / A Trezena de Santo Ant?nio, em Pradoso, ? um festejo anual, que se realiza entre os dias 1? e 13 de junho. Desde a sua prepara??o at? a realiza??o do festejo s?o empregados saberes e t?cnicas tradicionais, que s?o compartilhados pela comunidade. Estes saberes, constru?dos ao longo de gera??es, ligados ? religiosidade popular, se constituem em processos educativos que constroem, por meio da oralidade, de pr?ticas e experi?ncias do cotidiano, o sentimento de pertencimento. Uma an?lise das cenas, dos saberes e dos sujeitos envolvidos no festejo, revela a forma e o conte?do de pr?ticas capazes de construir territ?rios simb?licos de pertencimento. Sendo assim, a Trezena de Santo Ant?nio, em Pradoso, enquanto territorialidade humana, ? concebida enquanto um locus de aprendizado do pertencimento, reafirmando valores comunit?rios como: a solidariedade, o servi?o, a fraternidade, a integra??o, dentre outros. Enquanto refer?ncia emp?rica para uma an?lise da import?ncia do pertencimento, a Trezena de Santo Ant?nio, em Pradoso, oferece subs?dios para uma produ??o de conhecimentos pautada pela compreens?o da necessidade de uma religa??o dos saberes t?cnicos e human?sticos.

Les travaux de cette thèse sont centrés sur le développement de systèmes moléculaires en solution homogène pour la production photocatalytique de dihydrogène dans l'eau utilisant des catalyseurs de cobalt à ligands pentadentate tétrapyridinique ou tétra- et pentaaza macrocycliques. Associés au photosensibilisateur et à l’ascorbate comme donneur d’électron sacrificiel, les complexes à ligands macrocycliques présentent d’excellentes performances pour la production d’H2, bien supérieures à celles des complexes à ligands polypyridiniques en termes d’efficacité et de stabilité, en raison de la grande stabilité de leur état réduit «Co(I)». Enfin, [Ru(bpy)3]2+ a pu être substitué par un colorant organique très robuste du type triazatriangulénium conduisant à un système photocatalytique encore plus performant. Ces résultats démontrent que les colorants organiques sont une alternative viable aux photosensibilisateurs à base de métaux nobles, même en milieu aqueux acide. / The work of this manuscript is focused on the design of molecular systems in homogeneous solution for photocatalytic production of molecular hydrogen in water using cobalt catalysts with pentadentate tetrapyridinic and tetra- and pentaza macrocyclic ligands. In association with [Ru(bpy)3]2+ as photosensitizer and sodium ascorbate as sacrificial electron donor, the macrocycle based catalysts display high performances for H2 production, far exceeding those of the polypyridine based catalysts, both in terms of activity and stability, because of the stability of their reduced state «Co(I)». Finally, [Ru(bpy)3]2+ was successfully substituted with a robust organic dye belonging to the triazatriangulenium family, leading to an even more efficient photocatalytic system. These results demonstrate well that organic dyes are a truly efficient alternative to noble metal based photosensitizers, even in acidic aqueous medium.