Orientador: Antonio Celso de Oliveira Braga / Banca: Vagner Roberto Elis / Banca: César Augusto Moreira / Resumo: Estudos ambientais envolvendo investigação e mapeamento do meio geológico por meio de métodos geoelétricos apresentam resultados satisfatórios para contaminantes iônicos (chorume) que sugerem eficácia no emprego desses métodos em situações que apresentem alterações dos componentes do subsolo devido à presença de combustíveis, como o etanol. Integrando a aplicação dos métodos geofísicos da eletrorresistividade, polarização induzida e potencial espontâneo, por meio das técnicas de caminhamento elétrico e perfilagem elétrica foi monitorada a variação temporal dos parâmetros físicos resistividade, cargabilidade elétrica e potencial espontâneo em sedimentos arenosos alterados devido à contaminação controlada de etanol, contidos em um tanque de monitoramento. O tanque de monitoramento contém um sistema de controle do nível de saturação, possibilitando análises das variações nos parâmetros geoelétricos investigados em dois extratos geoelétricos: insaturado e saturado. O presente trabalho objetiva avaliar o comportamento do etanol num experimento que simula condições hidrogeológicas reais, bem como caracterizar as variações temporais nos parâmetros geoelétricos analisados. Este tipo de pesquisa objetiva também a geração de subsídios técnico/científico que auxiliem a compreensão de estudos de caso em ambientes naturais / Abstract: Environmental studies involving research and mapping of geological environment by geoelectrical methods present satisfactory results for ionic contaminants (leachate) that suggest effectiveness in their use in situations that present changes in components of the basement due to the presence of fuels such as ethanol. Integrating the application of geophysical methods of resistivity, induced polarization and spontaneous potential, through the techniques of electrical profiling and electrical profiling was monitored temporal variation of physical parameters, resistivity, chargeability and electrical spontaneous potential in sandy sediments changed due to contamination of controlled ethanol contained in a tank monitoring. The tank contains a monitoring system to control the saturation level, allowing analysis of variations in geoelectrical parameters investigated in two extracts geoelectrical: unsaturated and saturated. This study aims to evaluate the behavior of ethanol in an experiment that simulates actual hydrogeological conditions and to characterize temporal variations in geoelectrical parameters analyzed. This type of research also aims to generate subsidies technical / scientific understanding to help the case studies in natural environments / Mestre

Made available in DSpace on 2014-06-11T19:26:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-19Bitstream added on 2014-06-13T20:33:56Z : No. of bitstreams: 1 castello_lz_me_rcla.pdf: 3708951 bytes, checksum: 0a40d517edbecb13c7bec61c650816dd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Estudos ambientais envolvendo investigação e mapeamento do meio geológico por meio de métodos geoelétricos apresentam resultados satisfatórios para contaminantes iônicos (chorume) que sugerem eficácia no emprego desses métodos em situações que apresentem alterações dos componentes do subsolo devido à presença de combustíveis, como o etanol. Integrando a aplicação dos métodos geofísicos da eletrorresistividade, polarização induzida e potencial espontâneo, por meio das técnicas de caminhamento elétrico e perfilagem elétrica foi monitorada a variação temporal dos parâmetros físicos resistividade, cargabilidade elétrica e potencial espontâneo em sedimentos arenosos alterados devido à contaminação controlada de etanol, contidos em um tanque de monitoramento. O tanque de monitoramento contém um sistema de controle do nível de saturação, possibilitando análises das variações nos parâmetros geoelétricos investigados em dois extratos geoelétricos: insaturado e saturado. O presente trabalho objetiva avaliar o comportamento do etanol num experimento que simula condições hidrogeológicas reais, bem como caracterizar as variações temporais nos parâmetros geoelétricos analisados. Este tipo de pesquisa objetiva também a geração de subsídios técnico/científico que auxiliem a compreensão de estudos de caso em ambientes naturais / Environmental studies involving research and mapping of geological environment by geoelectrical methods present satisfactory results for ionic contaminants (leachate) that suggest effectiveness in their use in situations that present changes in components of the basement due to the presence of fuels such as ethanol. Integrating the application of geophysical methods of resistivity, induced polarization and spontaneous potential, through the techniques of electrical profiling and electrical profiling was monitored temporal variation of physical parameters, resistivity, chargeability and electrical spontaneous potential in sandy sediments changed due to contamination of controlled ethanol contained in a tank monitoring. The tank contains a monitoring system to control the saturation level, allowing analysis of variations in geoelectrical parameters investigated in two extracts geoelectrical: unsaturated and saturated. This study aims to evaluate the behavior of ethanol in an experiment that simulates actual hydrogeological conditions and to characterize temporal variations in geoelectrical parameters analyzed. This type of research also aims to generate subsidies technical / scientific understanding to help the case studies in natural environments

Made available in DSpace on 2014-06-11T19:32:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-24Bitstream added on 2014-06-13T20:43:11Z : No. of bitstreams: 1 moreira_ca_dr_rcla.pdf: 2315680 bytes, checksum: 0c4f65c2b2bcf53160a74f7b3683d14b (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho realiza um monitoramento em uma área de disposição de resíduos sólidos, para análise do comportamento temporal dos materiais enterrados e verificação da hipótese de aplicação e uso dos métodos geofísicos em estudos que prevejam o término na geração de chorume em aterros. Foram medidos os parâmetros físicos: resistividade elétrica, cargabilidade e potencial elétrico natural, a partir dos métodos geofísicos de Eletrorresistividade, Polarização Induzida e Potencial Espontâneo, por meio da técnica de caminhamento elétrico e de sondagem elétrica vertical. Também foram realizadas medidas de pH, Eh, ensaios de peneiramento, análise granulométrica e permeabilidade hidráulica de campo. Foi investigado o Aterro Controlado Municipal de Cordeirópolis (SP), uma área de disposição de resíduos sólidos domiciliares em valas escavadas no solo, com datas de abertura e fechamento programadas. A aquisição de dados consistiu na seleção de valas anualmente fechadas entre 12/2001 e 12/2007, realização dos ensaios geofísicos e coleta de solo para medidas de pH e Eh. Houve um aumento do potencial espontâneo das valas recentes para as valas antigas, possivelmente associado à estabilidade geoquímica crescente ao longo do período de degradação dos resíduos orgânicos. Há uma correlação entre baixa resistividade e alta cargabilidade em áreas ricas em matéria orgânica, enquanto que áreas com escassez de matéria orgânica são caracterizadas por baixos valores de cargabilidade e de resistividade. Também há uma correlação entre anomalias de baixo potencial espontâneo e de alta cargabilidade. A variação relativa dos parâmetros para cada vala, associados ao tempo de residência dos materiais, permitiu relacioná-los às fases de degradação de matéria orgânica em aterros. A análise estatística dos valores indica ser necessário 8 anos para... / This work accomplishes a monitoring in solid waste landfill, for analysis of the temporary behavior of the buried materials and verification of the application hypothesis and use of the geophysical methods in studies that foresee the end in the leachate generation in landfill. They were measured the physical parameters: electric resistivity, chargeability and natural electric potential, starting from the geophysical methods of Electrical Resistivity, Induced Polarization and Spontaneous Potential, through the techniques of electric profiling and vertical electric sounding. Were also accomplished pH and Eh measures, sieving, granulates analysis and hydraulic permeability field. The Cordeirópolis Solids Waste Landfill was investigated, a disposition area of domiciliary residues in ditches dug in the soil, with opening and closing programmed dates. The data acquisition consisted in annually selection of ditches closed between 12/2001 and 12/2007, accomplishment of the geophysical survey and soil collection for pH and Eh measures. There was an increase of the spontaneous potential of the recent ditches for the old ditches, possibly associated to the geochemical stability growing along the period of degradation of the organic residues. There is a correlation between low resistivity and high chargeability in rich areas in organic matter, while areas with shortage of organic matter are characterized by low chargeability values and of low resistivity. There is also a correlation among anomalies of low spontaneous potential and high chargeability. The relative variation of the parameters for each ditch, associated to residence time of the materials, allowed relating them the phases of degradation of organic matter in landfills. The statistical analysis of the values indicates to be necessary 8 years for return to the natural resistivity values of the rock located to 10m of depth and 12 years... (Complete abstract click electronic access below)

Orientador: Antonio Celso de Oliveira Braga / Banca: Marcos Daniel Bonotto / Banca: Otavio Coaracy Brasil Galdolfo / Banca: Vagner Roberto Elis / Banca: José Domingos Faraco Gallas / Resumo: Este trabalho realiza um monitoramento em uma área de disposição de resíduos sólidos, para análise do comportamento temporal dos materiais enterrados e verificação da hipótese de aplicação e uso dos métodos geofísicos em estudos que prevejam o término na geração de chorume em aterros. Foram medidos os parâmetros físicos: resistividade elétrica, cargabilidade e potencial elétrico natural, a partir dos métodos geofísicos de Eletrorresistividade, Polarização Induzida e Potencial Espontâneo, por meio da técnica de caminhamento elétrico e de sondagem elétrica vertical. Também foram realizadas medidas de pH, Eh, ensaios de peneiramento, análise granulométrica e permeabilidade hidráulica de campo. Foi investigado o Aterro Controlado Municipal de Cordeirópolis (SP), uma área de disposição de resíduos sólidos domiciliares em valas escavadas no solo, com datas de abertura e fechamento programadas. A aquisição de dados consistiu na seleção de valas anualmente fechadas entre 12/2001 e 12/2007, realização dos ensaios geofísicos e coleta de solo para medidas de pH e Eh. Houve um aumento do potencial espontâneo das valas recentes para as valas antigas, possivelmente associado à estabilidade geoquímica crescente ao longo do período de degradação dos resíduos orgânicos. Há uma correlação entre baixa resistividade e alta cargabilidade em áreas ricas em matéria orgânica, enquanto que áreas com escassez de matéria orgânica são caracterizadas por baixos valores de cargabilidade e de resistividade. Também há uma correlação entre anomalias de baixo potencial espontâneo e de alta cargabilidade. A variação relativa dos parâmetros para cada vala, associados ao tempo de residência dos materiais, permitiu relacioná-los às fases de degradação de matéria orgânica em aterros. A análise estatística dos valores indica ser necessário 8 anos para... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work accomplishes a monitoring in solid waste landfill, for analysis of the temporary behavior of the buried materials and verification of the application hypothesis and use of the geophysical methods in studies that foresee the end in the leachate generation in landfill. They were measured the physical parameters: electric resistivity, chargeability and natural electric potential, starting from the geophysical methods of Electrical Resistivity, Induced Polarization and Spontaneous Potential, through the techniques of electric profiling and vertical electric sounding. Were also accomplished pH and Eh measures, sieving, granulates analysis and hydraulic permeability field. The Cordeirópolis Solids Waste Landfill was investigated, a disposition area of domiciliary residues in ditches dug in the soil, with opening and closing programmed dates. The data acquisition consisted in annually selection of ditches closed between 12/2001 and 12/2007, accomplishment of the geophysical survey and soil collection for pH and Eh measures. There was an increase of the spontaneous potential of the recent ditches for the old ditches, possibly associated to the geochemical stability growing along the period of degradation of the organic residues. There is a correlation between low resistivity and high chargeability in rich areas in organic matter, while areas with shortage of organic matter are characterized by low chargeability values and of low resistivity. There is also a correlation among anomalies of low spontaneous potential and high chargeability. The relative variation of the parameters for each ditch, associated to residence time of the materials, allowed relating them the phases of degradation of organic matter in landfills. The statistical analysis of the values indicates to be necessary 8 years for return to the natural resistivity values of the rock located to 10m of depth and 12 years... (Complete abstract click electronic access below) / Doutor

<p>Self-oscillating behaviour in alkaline Cu(II)-lactate and -tartrate systems has been investigated by in-situ pH and confocal Raman spectroscopy measurements. Formation of Cu(II)-lactate and -tartrate complexes is a key factor underlying the self-oscillations. Dynamic processes in the diffusion layer have been probed to give a better understanding of the self-oscillating process.</p><p>The self-oscillating behaviour is found to be an effect of pH variations in the diffusion layer. Mainly copper is deposited at lower pH values and potentials; at the same time, the pH increases. This is an effect of the dissociation of the Cu(II)-complex during electrochemical reduction. The absence of a buffer within a given pH region is crucial to the fast and sudden pH increase and thereby to the positive potential shift, where cuprous oxide is deposited. A precipitation reaction probably decreases the pH again, leading to a negative potential shift, and copper again begins to deposit. The concentration and strength of the buffer in the electrolyte affect the appearance of the oscillation pattern. The pH and temperature of the bulk electrolyte also influence the self-oscillations. The deposit consists of copper and cuprous oxide, where the composition of the phases deposited is a function of the working-electrode potential. Cuprous oxide is deposited at the higher potentials and mainly copper at the lower potentials.</p><p>Finally, two-dimensional arrays of Cu/Cu₂O microcylinders have been deposited using the Cu(II)-lactate system through the application of a template method.</p>

Self-oscillating behaviour in alkaline Cu(II)-lactate and -tartrate systems has been investigated by in-situ pH and confocal Raman spectroscopy measurements. Formation of Cu(II)-lactate and -tartrate complexes is a key factor underlying the self-oscillations. Dynamic processes in the diffusion layer have been probed to give a better understanding of the self-oscillating process. The self-oscillating behaviour is found to be an effect of pH variations in the diffusion layer. Mainly copper is deposited at lower pH values and potentials; at the same time, the pH increases. This is an effect of the dissociation of the Cu(II)-complex during electrochemical reduction. The absence of a buffer within a given pH region is crucial to the fast and sudden pH increase and thereby to the positive potential shift, where cuprous oxide is deposited. A precipitation reaction probably decreases the pH again, leading to a negative potential shift, and copper again begins to deposit. The concentration and strength of the buffer in the electrolyte affect the appearance of the oscillation pattern. The pH and temperature of the bulk electrolyte also influence the self-oscillations. The deposit consists of copper and cuprous oxide, where the composition of the phases deposited is a function of the working-electrode potential. Cuprous oxide is deposited at the higher potentials and mainly copper at the lower potentials. Finally, two-dimensional arrays of Cu/Cu2O microcylinders have been deposited using the Cu(II)-lactate system through the application of a template method.

L'importance des enjeux liés à la qualité et à la connaissance de l'eau souterraine nécessite de caractériser le fonctionnement des nappes d’eaux souterraines. En hydrogéologie, les méthodes qui permettent de réaliser le modèle conceptuel d’un aquifère reposent généralement sur l’observation et la caractérisation du milieu, à partir notamment de la mise en place de forages et la réalisation de pompages d’essai. Cependant, ces méthodes présentent des limites pour caractériser la variabilité spatiale des aquifères hétérogènes. Dans cette thèse, nous nous sommes intéressés au développement d’approches expérimentales qui utilisent des informations issues de traçage thermique ou salin pour la caractérisation des paramètres hydrauliques des milieux hétérogènes poreux. Ce choix expérimental a été justifié 1) par les difficultés de prise en compte des hétérogénéités hydrauliques dans les milieux poreux naturels et 2) pour une meilleure compréhension des phénomènes mis en jeu en situation contrôlée. Dans les travaux réalisés, nous avons tout d’abord proposé d’utiliser des mesures thermiques ponctuelles, puis obtenues dans l'infrarouge thermique pour estimer les paramètres hydrauliques en milieux poreux hétérogènes. Cependant, les méthodes de traçage thermiques étant limitées dans les zones faiblement perméables, nous avons fait évoluer notre approche en la combinant avec une méthode géophysique (Potentiel Spontané). Cette méthode, sensible aux écoulements des fluides et aux processus thermoélectrique et électrochimique, nous a permis de collecter des données temporelles intéressantes pour surveiller des variations thermiques ou saline provoquées dans les milieux. Les mesures obtenues ont été par la suite utilisées dans des algorithmes d’inversion pour estimer les distributions spatiales des propriétés hydrauliques. Les résultats obtenus nous ont permis de montrer l’efficacité de ces approches pour la caractérisation des milieux hétérogènes et par conséquent pour la modélisation des écoulements des fluides dans ces milieux. / The importance of issues related to the quality of groundwater requires characterizing the operation of groundwater aquifers. Hydrogeological methods used to carry out conceptual model of an aquifer are generally based on the observation and characterization of the medium, by using boreholes and carrying out of pumping test operations. However, these methods present some limitations in characterizing the spatial variability of heterogeneous aquifers. In this thesis, we develop experimental approaches that use information from thermal or saline tracing for the characterization of hydraulic parameters in heterogeneous porous media. The choice of using experimental approaches was justified 1) by difficulties of taking into account hydraulic heterogeneities in natural porous media and 2) for a better understanding of the phenomena involved in a controlled situation. In this work, we first proposed the use of punctual thermal measurements, then measurements obtained by using thermal infrared to estimate hydraulic parameters in heterogeneous porous media. However, as thermal tracing methods are limited in low permeability areas, we improved our approach by combining it with a geophysical method (Spontaneous Potential). This method, sensitive to fluid flows and thermoelectric and electrochemical processes, has allowed us to collect interesting temporal data to monitor thermal or saline variations in the media. The measurements obtained were then used in inversion algorithms to estimate the spatial distributions of hydraulic properties. The results obtained allowed to demonstrate the effectiveness of these approaches for the characterization of heterogeneous media and consequently for the modelling of fluid flows.