Made available in DSpace on 2017-07-10T19:24:35Z (GMT). No. of bitstreams: 1 Rosimaldo Soncela.pdf: 1165359 bytes, checksum: 65125007d81deb1038c3d55926b33252 (MD5) Previous issue date: 2010-06-30 / The swine waste water (SWW) application in soil has become an alternative fertilizer for soil and used as a water reuse. However, special attention must be given to the amount of salt content in such water since succeeding applications can stimulate the saltishness process on soil, which can ask for an indispensable monitoring of salt content in soil. The time-domain reflectometry (TDR) allows for a continuous and simultaneous monitoring of water content and apparent electric conductivity on soil (AEC), in order to make feasible the indirect determination of electric conductivity of soil solution, which can estimate salt content in the soil. Nevertheless, there is a need to obtain and calibrate a model for each type of soil. Thus, this trial aimed at obtaining a volumetric humidity calibration model for a typical Distroferric Red Latosol, as well as studying this technique viability to indirectly determine the electrical conductivity in a soil solution using an empiric equation for the TDR Trase 6050X1 devise. Calibration was performed under laboratory conditions, with deformed samples of the studied soil, conditioned in columns, with a 0.0078 m3 volume. TDR hand-made probes, with three 0.20m-long shafts, were vertically installed in the soil columns, five probes per column, totaling 16 columns. The weighing answers were obtained by digital scales and daily readings with the TDR equipment. To indirectly determine soil solution electric conductivity, deformed and saturated samples were used and saturated with SWW at 0, 10, 20, 40, 60, and 80 liters with a soil volume of 0.0225 m3. The SWW was evaporated so that saturated soil got completely dry and sieved in a 2 mm sieve to obtain the air dried fine soil (ADFS). The volumes of dried soils were conditioned in three columns to characterize T0, T1, T2, T3, T4 and T5 treatments. The same procedure was carried out for probes calibration. At that moment, four probes were installed by column, totaling 18 columns. The empirical model to estimate the volumetric soil humidity under study showed an adequate degree of determination. At last, It was possible to establish an empirical model that connected AEC recorded by the TDR equipment and electrical conductivity of saturated soil sample (ECss), making possible the use of this technique on soil salinity estimation. / A aplicação de águas residuárias de suinocultura (ARS) no solo vem sendo uma alternativa como forma de adubação e reúso de água. Entretanto, atenção especial deve ser dada à quantidade de sais contidos nessas águas, uma vez que aplicações sucessivas podem favorecer o processo de salinização do solo, tornando-se necessário um monitoramento do teor de sais no solo. A reflectometria no domínio do tempo (TDR) possibilita o monitoramento simultâneo e contínuo do teor de água e da condutividade elétrica aparente do solo (CEa) a fim de viabilizar a determinação indireta da condutividade elétrica da solução do solo, a qual possibilita a estimativa do teor de sais no solo. Porém, há necessidade de obtenção e calibração de um modelo para cada tipo de solo. Desta forma, o objetivo deste trabalho foi obter um modelo de calibração de umidade volumétrica para um Latossolo Vermelho Distroférrico Típico, bem como estudar a viabilidade da técnica na determinação indireta da condutividade elétrica da solução do solo por meio de uma equação empírica para o equipamento TDR Trase 6050X1. A calibração foi realizada em condições de laboratório, utilizando amostras deformadas do solo em estudo, acondicionadas em colunas com volume de 0,0078 m3. As sondas fabricadas artesanalmente da TDR com três hastes e 0,20 m de comprimento foram instaladas verticalmente nas colunas de solo, em um total de cinco sondas por coluna, totalizando 16 colunas. Realizaram-se as pesagens com balança digital e leituras diárias com o equipamento TDR. Para a determinação indireta da condutividade elétrica da solução do solo, foram utilizadas amostras deformadas, as quais foram saturadas com ARS nas taxas de 0, 10, 20, 40, 60 e 80 litros por um volume de 0,0225 m3 de solo. Deixou-se que a ARS evaporasse até que o solo saturado secasse totalmente, peneirado em peneira de 2 mm para formar Terra Fina Seca ao Ar (TFSA). Os volumes de solos secos foram acondicionados em três colunas, caracterizando-se os tratamentos T0, T1, T2, T3, T4 e T5. O mesmo processo ocorreu para a calibração das sondas. Nesta etapa, foram instaladas quatro sondas por coluna totalizando 18 colunas. O modelo empírico para estimativa da umidade volumétrica do solo em estudo apresentou suficiente grau de determinação. Foi possível estabelecer um modelo empírico que relacionou a condutividade elétrica aparente do solo (CETDR) e a condutividade elétrica do extrato saturado do solo (CEes) para viabilizar o uso da técnica na estimativa da salinidade do solo.

Made available in DSpace on 2017-07-10T19:24:51Z (GMT). No. of bitstreams: 1 Almiro Weiss.pdf: 7452787 bytes, checksum: 197399ca28d2e0c6c30badfe29ff070b (MD5) Previous issue date: 2005-07-01 / The compaction of the agricultural soils has worldwide importance because of the increasing of the farm with machinery resulting in the increasing of heavy machines for cultivation system, mainly, in the developed countries. The term, soils compaction refers to the compression carried out on the non-saturated soil, during which an increase of bulk density exists, producing the reduction of its volume of pores like a consequence. The excessive compaction has damaging consequences for the agriculture and environmental. For this reason, the state of soils compacting has received enough attention from researchers and agricultural farmers. The uniaxial compression has been used for predicting the agricultural soils compaction with so much efficiency. In accordance to the previous exposure, in this paper aimed the to develop an apparatus of uniaxial compression of the soil for testing in laboratory and evaluating its performance. The apparatus is composed by a pneumatic press, where the sample of soil is packaged in a metallic volumetric ring (made in steel carbon - ABNT 1020), with thickness of wall of 0,2 cm, internal diameter of 7,0 cm and two options of height of 2,4 cm and 4,8 cm. Cyclical loads of compression were applied to the sample in order to verify the variation of the soil deformation. A lineal transducer detects the samples behavior during the compression and uncompression (relaxation) uniaxial indicating in the digital counter s display the variations of measure of the sample deformation. Successive loads of 150, 200, 300, 400, 500, 600, 700 and 800 kPa were applied in periods of 60 s for compression and 120 s for uncompression of the sample. The results allowed conclude that the system presents answers with good precision and greater versatility with the variation of de samples size for compression. / A compactação dos solos agrícolas tem importância mundial em função do crescimento das áreas mecanizadas, acarretando o aumento de máquinas pesadas nos sistemas de cultivo, principalmente, nos países desenvolvidos. O termo compactação do solo refere-se a sua compressão realizada no solo não saturado, durante a qual existe um aumento de densidade produzindo como conseqüência redução de seu volume de poros. A excessiva compactação tem conseqüências danosas para a agricultura e para o meio ambiente. Por essas razões, o estado de compactação do solo tem recebido bastante atenção de pesquisadores e produtores agrícolas. O ensaio de compressão uniaxial tem sido utilizado para determinar a compactação dos solos agrícolas com muita eficiência. Face ao exposto, este trabalho estabeleceu como objetivo desenvolver um aparelho de compressão uniaxial do solo para ensaio em laboratório e avaliar o seu desempenho. O aparelho é composto por uma prensa pneumática, em que a amostra de solo fica acondicionada em um anel volumétrico metálico (feito em aço carbono - ABNT 1020, cromado), com espessura de parede de 0,2 cm, com diâmetro interno de 7,0 cm e com duas opções de altura de 2,4 cm e 4,8 cm. Cargas cíclicas de compressão foram aplicadas na amostra para verificar a variação da deformação do solo. Um transdutor linear detecta o comportamento da amostra durante a compressão e descompressão (relaxamento) uniaxial indicando no display do contador digital as variações de medida da deformação da amostra. Cargas seqüenciais de 150, 200, 300, 400, 500, 600, 700 e 800 kPa foram aplicadas em intervalos de tempo de: 60 s para compressão e 120 s para descompressão da amostra. Os resultados permitiram concluir que o sistema apresenta respostas com boa precisão e maior versatilidade, com variação do tamanho das amostras para compressão.

O objetivo principal desta pesquisa é avaliar a influência que as propriedades estudadas dos agregados exercem sobre propriedades volumétricas e mecânicas de misturas asfálticas densas. Para tanto, foram avaliadas as propriedades de consenso e de origem, especificadas pelo Superpave, de um conjunto de agregados, além de suas densidades, porosidade, absorção e adesividade. Foram estudados agregados de gabro, basalto e areia natural e três tipos de granulometrias, uma denominada AZR, passando acima da zona de restrição da especificação Superpave, e outras duas, obtidas através do sistema de seleção granulométrica Bailey. Também três níveis de energia de compactação foram aplicados às misturas, 75, 110 e 155 golpes por face do corpo-de-prova Marshall. Avaliou-se o comportamento mecânico das misturas através dos ensaios de estabilidade e fluência Marshall, fluência por compressão uniaxial uniforme, fluência por compressão uniaxial dinâmica, resistência à tração, módulo de resiliência e fadiga. Os resultados mostraram que, de uma maneira geral, o agregado de gabro apresentou superioridade em relação ao agregado de basalto e de areia natural, tanto quando analisado isoladamente como quando analisado nas misturas asfálticas. Suas características de forma, angularidade e textura superficial permitiram arranjos entre partículas adequados, formando esqueletos estruturais resistentes à deformação permanente e também à fadiga. As análises das misturas à luz da granulometria mostram que, de uma maneira geral, a granulometria AZR produziu misturas mais estáveis, mais resistentes à deformação permanente e à fadiga. Pôde-se constatar, também, que as propriedades volumétricas são sensíveis às densidades dos agregados e à taxa de absorção destes, além de serem influenciadas diretamente pelas características de superfície dos agregados e pela energia de compactação. Com o aumento da energia de compactação aplicada, as partículas angulosas e rugosas dos agregados de gabro e de basalto arranjaram-se de maneira mais próxima e, por conseqüência, houve a diminuição dos vazios do agregado mineral e elevação da estabilidade e rigidez das misturas, sem, contudo, causar prejuízos à vida de fadiga. Os estudos sobre a absorção de asfalto pelos agregados revelaram que os agregados absorvem mais asfalto quanto mais fina a espessura da película de asfalto que os envolve e, também, que misturas com um mesmo teor de asfalto absorvem quantidades semelhantes de asfalto, sendo o tempo necessário para que a absorção se complete diretamente proporcional à viscosidade (temperatura) do asfalto. / The main objective of this research is to evaluate the influence that the studied properties of aggregates have on volumetric and mechanical characteristics of dense asphalt mixtures. It was evaluated origin and consensus properties, specified by the Superpave, for a set of aggregates, besides their densities, porosity, absorption and adhesiveness. Aggregates of gabbro, basalt and natural sand were studied and three types of aggregate gradations, one called AZR, passing above the zone of restriction of the Superpave specification, and two others, obtained through the Bailey method. Three levels of compaction energy were applied, corresponding respectively to 75, 110 and 155 blows of the Marshall hammer per face of the specimen. The mechanical behavior of the hot mix asphalt (HMA) was evaluated through the Marshall stability and flow, static and dynamic creep, indirect tensile strength, resilient modulus and fatigue tests. The results showed that, in general terms, the gabbro aggregate presented a superior behavior compared to the natural sand aggregate and the basalt aggregate, based on both aggregate and asphalt mixture evaluation tests. Its characteristics of form, angularity and surface texture resulted in an adequate arrangement between particles, building a resistant structural skeleton to both permanent deformation and fatigue cracking. Analyses of the HMA mixtures as a function of gradation showed that, in general terms, AZR mixtures were more stable, more resistant to permanent deformation and to fatigue cracking than Bailey mixtures. It could be evidenced that the volumetric properties depends on the specific gravity and the absorption rate of the aggregates, being also directly influenced by aggregate surface characteristics and compaction energy. Increasing the energy applied for specimen compaction resulted, for the angular and rough particles of gabbro and basalt aggregates, in a closer arrangement, with reduction of the voids in mineral aggregate and increase of the stability and stiffness of the mixtures, without, however, causing damages that could conduct to a shorter fatigue life. The studies about absorption of asphalt by aggregates showed that the smaller the asphalt film thickness the greater the asphalt absorption. The results also showed that HMA with the same asphalt content absorb similar amounts of asphalt, although the necessary time to complete the absorption is directly proportional to the asphalt viscosity (temperature).

Made available in DSpace on 2017-05-12T14:47:58Z (GMT). No. of bitstreams: 1 Rosimaldo Soncela.pdf: 1165359 bytes, checksum: 65125007d81deb1038c3d55926b33252 (MD5) Previous issue date: 2010-06-30 / The swine waste water (SWW) application in soil has become an alternative fertilizer for soil and used as a water reuse. However, special attention must be given to the amount of salt content in such water since succeeding applications can stimulate the saltishness process on soil, which can ask for an indispensable monitoring of salt content in soil. The time-domain reflectometry (TDR) allows for a continuous and simultaneous monitoring of water content and apparent electric conductivity on soil (AEC), in order to make feasible the indirect determination of electric conductivity of soil solution, which can estimate salt content in the soil. Nevertheless, there is a need to obtain and calibrate a model for each type of soil. Thus, this trial aimed at obtaining a volumetric humidity calibration model for a typical Distroferric Red Latosol, as well as studying this technique viability to indirectly determine the electrical conductivity in a soil solution using an empiric equation for the TDR Trase 6050X1 devise. Calibration was performed under laboratory conditions, with deformed samples of the studied soil, conditioned in columns, with a 0.0078 m3 volume. TDR hand-made probes, with three 0.20m-long shafts, were vertically installed in the soil columns, five probes per column, totaling 16 columns. The weighing answers were obtained by digital scales and daily readings with the TDR equipment. To indirectly determine soil solution electric conductivity, deformed and saturated samples were used and saturated with SWW at 0, 10, 20, 40, 60, and 80 liters with a soil volume of 0.0225 m3. The SWW was evaporated so that saturated soil got completely dry and sieved in a 2 mm sieve to obtain the air dried fine soil (ADFS). The volumes of dried soils were conditioned in three columns to characterize T0, T1, T2, T3, T4 and T5 treatments. The same procedure was carried out for probes calibration. At that moment, four probes were installed by column, totaling 18 columns. The empirical model to estimate the volumetric soil humidity under study showed an adequate degree of determination. At last, It was possible to establish an empirical model that connected AEC recorded by the TDR equipment and electrical conductivity of saturated soil sample (ECss), making possible the use of this technique on soil salinity estimation. / A aplicação de águas residuárias de suinocultura (ARS) no solo vem sendo uma alternativa como forma de adubação e reúso de água. Entretanto, atenção especial deve ser dada à quantidade de sais contidos nessas águas, uma vez que aplicações sucessivas podem favorecer o processo de salinização do solo, tornando-se necessário um monitoramento do teor de sais no solo. A reflectometria no domínio do tempo (TDR) possibilita o monitoramento simultâneo e contínuo do teor de água e da condutividade elétrica aparente do solo (CEa) a fim de viabilizar a determinação indireta da condutividade elétrica da solução do solo, a qual possibilita a estimativa do teor de sais no solo. Porém, há necessidade de obtenção e calibração de um modelo para cada tipo de solo. Desta forma, o objetivo deste trabalho foi obter um modelo de calibração de umidade volumétrica para um Latossolo Vermelho Distroférrico Típico, bem como estudar a viabilidade da técnica na determinação indireta da condutividade elétrica da solução do solo por meio de uma equação empírica para o equipamento TDR Trase 6050X1. A calibração foi realizada em condições de laboratório, utilizando amostras deformadas do solo em estudo, acondicionadas em colunas com volume de 0,0078 m3. As sondas fabricadas artesanalmente da TDR com três hastes e 0,20 m de comprimento foram instaladas verticalmente nas colunas de solo, em um total de cinco sondas por coluna, totalizando 16 colunas. Realizaram-se as pesagens com balança digital e leituras diárias com o equipamento TDR. Para a determinação indireta da condutividade elétrica da solução do solo, foram utilizadas amostras deformadas, as quais foram saturadas com ARS nas taxas de 0, 10, 20, 40, 60 e 80 litros por um volume de 0,0225 m3 de solo. Deixou-se que a ARS evaporasse até que o solo saturado secasse totalmente, peneirado em peneira de 2 mm para formar Terra Fina Seca ao Ar (TFSA). Os volumes de solos secos foram acondicionados em três colunas, caracterizando-se os tratamentos T0, T1, T2, T3, T4 e T5. O mesmo processo ocorreu para a calibração das sondas. Nesta etapa, foram instaladas quatro sondas por coluna totalizando 18 colunas. O modelo empírico para estimativa da umidade volumétrica do solo em estudo apresentou suficiente grau de determinação. Foi possível estabelecer um modelo empírico que relacionou a condutividade elétrica aparente do solo (CETDR) e a condutividade elétrica do extrato saturado do solo (CEes) para viabilizar o uso da técnica na estimativa da salinidade do solo.

Made available in DSpace on 2017-05-12T14:48:14Z (GMT). No. of bitstreams: 1 Almiro Weiss.pdf: 7452787 bytes, checksum: 197399ca28d2e0c6c30badfe29ff070b (MD5) Previous issue date: 2005-07-01 / The compaction of the agricultural soils has worldwide importance because of the increasing of the farm with machinery resulting in the increasing of heavy machines for cultivation system, mainly, in the developed countries. The term, soils compaction refers to the compression carried out on the non-saturated soil, during which an increase of bulk density exists, producing the reduction of its volume of pores like a consequence. The excessive compaction has damaging consequences for the agriculture and environmental. For this reason, the state of soils compacting has received enough attention from researchers and agricultural farmers. The uniaxial compression has been used for predicting the agricultural soils compaction with so much efficiency. In accordance to the previous exposure, in this paper aimed the to develop an apparatus of uniaxial compression of the soil for testing in laboratory and evaluating its performance. The apparatus is composed by a pneumatic press, where the sample of soil is packaged in a metallic volumetric ring (made in steel carbon - ABNT 1020), with thickness of wall of 0,2 cm, internal diameter of 7,0 cm and two options of height of 2,4 cm and 4,8 cm. Cyclical loads of compression were applied to the sample in order to verify the variation of the soil deformation. A lineal transducer detects the samples behavior during the compression and uncompression (relaxation) uniaxial indicating in the digital counter s display the variations of measure of the sample deformation. Successive loads of 150, 200, 300, 400, 500, 600, 700 and 800 kPa were applied in periods of 60 s for compression and 120 s for uncompression of the sample. The results allowed conclude that the system presents answers with good precision and greater versatility with the variation of de samples size for compression. / A compactação dos solos agrícolas tem importância mundial em função do crescimento das áreas mecanizadas, acarretando o aumento de máquinas pesadas nos sistemas de cultivo, principalmente, nos países desenvolvidos. O termo compactação do solo refere-se a sua compressão realizada no solo não saturado, durante a qual existe um aumento de densidade produzindo como conseqüência redução de seu volume de poros. A excessiva compactação tem conseqüências danosas para a agricultura e para o meio ambiente. Por essas razões, o estado de compactação do solo tem recebido bastante atenção de pesquisadores e produtores agrícolas. O ensaio de compressão uniaxial tem sido utilizado para determinar a compactação dos solos agrícolas com muita eficiência. Face ao exposto, este trabalho estabeleceu como objetivo desenvolver um aparelho de compressão uniaxial do solo para ensaio em laboratório e avaliar o seu desempenho. O aparelho é composto por uma prensa pneumática, em que a amostra de solo fica acondicionada em um anel volumétrico metálico (feito em aço carbono - ABNT 1020, cromado), com espessura de parede de 0,2 cm, com diâmetro interno de 7,0 cm e com duas opções de altura de 2,4 cm e 4,8 cm. Cargas cíclicas de compressão foram aplicadas na amostra para verificar a variação da deformação do solo. Um transdutor linear detecta o comportamento da amostra durante a compressão e descompressão (relaxamento) uniaxial indicando no display do contador digital as variações de medida da deformação da amostra. Cargas seqüenciais de 150, 200, 300, 400, 500, 600, 700 e 800 kPa foram aplicadas em intervalos de tempo de: 60 s para compressão e 120 s para descompressão da amostra. Os resultados permitiram concluir que o sistema apresenta respostas com boa precisão e maior versatilidade, com variação do tamanho das amostras para compressão.

[pt] A reconstrução de cenas a partir de imagens tem recebido, recentemente, grande interesse por parte dos pesquisadores das áreas de visão computacional, computação gráfica e modelagem geométrica. Várias são as suas aplicações como, por exemplo, modelagem de objetos a partir de imagens, construção de ambientes virtuais e telepresença. Dentre os métodos que têm produzido bons resultados na reconstrução de cenas a partir de imagens, podemos destacar aqueles que se baseiam em algoritmos de Escultura do Espaço. Tais técnicas procuram determinar quais são os elementos, em uma representação volumétrica do espaço da cena, que satisfazem um conjunto de restrições fotométricas impostas por um conjunto de imagens. Uma vez determinados, tais elementos volumétricos são coloridos de modo que reproduzam as informações fotométricas nas imagens de entrada, com uma certa margem de tolerância especificada com base em critérios estatísticos. Neste trabalho, investigamos o emprego de técnicas utilizadas em visualização no desenvolvimento de métodos de escultura do espaço. Como resultado, propomos um método por refinamento adaptativo que trabalha sobre espaços de reconstrução representados através de subdivisões espaciais. Tal método é capaz de realizar o processo de reconstrução de modo mais eficiente, empregando esforços proporcionais às características locais da cena, que são descobertas à medida em que a reconstrução é realizada. Finalmente, avaliamos a qualidade e a eficiência do método proposto, com base em um conjunto de resultados obtidos através de um sistema de reconstrução de objetos que utiliza imagens capturadas por webcams. / [en] The reconstruction of scenes from imagens has received special attention from researchers of the areas of computer vision, computer graphics and geometric modeling. As examples of application we can mention image-based scene reconstruction, modeling of complex as-built objects, construction of virtual environments and telepresence. Among the most successful methods used for the reconstruction of scenes from images are those based on Space Carving algorithms. These techniques reconstruct the shape of the objects of interest in a scene by determining, in a volumetric representation of the scene space, those elements that satisfy a set of photometric constraints imposed by the input images. Once determined, each photo- consistent element is colorized according to the photometric information in the input images, in such a way that they reproduce the photometric information in the input images, within some pre-specificied error tolerance. In this work, we investigate the use of rendering techniques in space carving methods. As a result, we propose a method based on an adaptive refinement process which works on reconstruction spaces represented by spatial subdivisions. We claim that such method can reconstruct the objects of interest in a more efficient way, using resources proportional to the local characteristics of the scene, which are discovered as the reconstruction takes place. Finally, we evaluate the quality and the efficiency of the method based on the results obtained from a reconstruction device that works with images captured from webcams.

The strain rate dependent behaviour of fine grained soils is an important aspect of geotechnical engineering. During dynamic or rapid events such as earthquakes and rapid pile testing, a fine grained soil will display significantly different behaviour than may be observed over the long life span of a structure. There is currently little understanding of the factors which influence the behaviour of fine grained soils during dynamic events (extremely high strain rates), making their response difficult to predict. This research investigates the behaviour of fine grained soils subjected to a wide range of constant strain rates in monotonic triaxial compression testing. Each test is conducted under drained conditions to observe the behaviour of soils as they transition from a drained response at lower strain rates, through to an undrained or viscous response at higher strain rate tests. Where the response of soils is drained or partially drained, higher strain rate tests measure a decrease in strength. The point of transition from partially drained to undrained behaviour corresponds to the lowest strain rate dependent strength. Further tests at higher strain rates measure consistently greater strength. The strain rate dependence of three fine grained soils is investigated, enabling a comparison of strain rate effects with soil index properties. The influence of initial state on the strain rate dependence of these Kaolin based model soils is also evaluated. The drained to partially drained response of the soils to strain rate increase is controlled by the coefficient of consolidation. Tests at high strain rates show the undrained or viscous strain rate effect on strength is related to liquidity index. Local strain instrumentation allowed comparison of strain rate effects on small strain stiffness. At higher strain rate the soils display increasingly linear behaviour. At non-linear elastic strains, liquidity index appears to control the magnitude of the strain rate effects on stiffness.

La présente dissertation est principalement consacrée à la conception et à la caractérisation d’une sonde universelle pour l’imagerie volumétrique ultrasons-optoacoustique et le développement d’un algorithme de reconstruction adapté aux exigences physiques pour la conception du système. Les traits distinctifs de cette dissertation sont l’introduction d’une nouvelle géométrie pour les sondes manuelles ultrasons-optoacoustique et des évaluations systématiques basées sur des méthodes de pré-reconstruction et post-reconstruction. Pour éviter l’interprétation biaisée, une évaluation capable d’évaluer le potentiel de la sonde doit être faite. Les caractéristiques mentionnées établissent un cadre pour l’évaluation des performances du système d’imagerie d’une manière précise. En outre, elle permet d’optimiser les performances suivant l’objectif fixé. Ainsi, deux algorithmes de reconstruction anticipée ont été élaborés pour la conception du système OPUS (optoacoustique ultrasons) capables de produire des images avec un contraste et une résolution homogènes sur tout le volume d’intérêt. L’intérêt d’avoir de tels algorithmes est principalement dû au fait que l’analyse des données médicales est souvent faite dans des conditions difficiles, car on est face au bruit, au faible contraste, aux projections limités et à des transformations indésirables opérées par les systèmes d’acquisition. Cette thèse montre, aussi, comment les artefacts de reconstruction peuvent être réduits en compensant les propriétés d’ouverture et en atténuant les artefacts dus à l’échantillonnage angulaire parcimonieux. Afin de transférer cette méthodologie à la clinique et de valider les résultats théoriques, une plate-forme d’imagerie expérimentale a été développée. En utilisant le système de mesure développé, l’évolution d’une nouvelle géométrie annulaire parcimonieuse et sa dynamique ont été étudiées et une preuve de concept a été démontrée à travers des mesures expérimentales dans le but d’évaluer les progrès réalisés. / When the interest is in multiscale and multipurpose imaging, there exists such a will in integrating multi-modalilties into a synergistic paradigm in order to leverage the diagnostic values of the interrogating agents. Employing multiple wavelengths radiation, optoacoustic imaging benefits from the optical contrast to specifically resolve molecular structure of tissue in a non-invasive manner. Hybridizing optoacoustic and ultrasound imaging comes with the promises of delivering the complementary morphological, functional and metabolic information of the tissue. This dissertation is mainly devoted to the design and characterization of a hybridized universal handheld probe for optoacoustic ultrasound volumetric imaging and developing adaptive reconstruction algorithms toward the physical requirements of the designed system. The distinguishing features of this dissertation are the introduction of a new geometry for optoacoustic ultrasonic handheld probe and systematic assessments based on pre and post reconstruction methods. To avoid the biased interpretation, a de facto performance assessment being capable of evaluating the potentials of the designed probe in an unbiased manner must be practiced. The aforementioned features establish a framework for characterization of the imaging system performance in an accurate manner. Moreover, it allows further task performance optimization as well. Correspondingly, two advanced reconstruction algorithms have been elaborated towards the requirement of the designed optoacoustic-ultrasound (OPUS) imaging system in order to maximize its ability to produce images with homogeneous contrast and resolution over the entire volume of interest. This interest is mainly due to the fact that the medical data analysis pipeline is often carried out in challenging conditions, since one has to deal with noise, low contrast, limited projections and undesirable transformations operated by the acquisition system. The presented thesis shows how reconstruction artifacts can be reduced by compensating for the detecting aperture properties and alleviate artifacts due to sparse angular sampling. In pursuit of transferring this methodology to clinic and validating the theoretical results, a synthetic imaging platform was developed. Using the measurement system, the evolution of a novel sparse annular geometry and its dynamics has been investigated and a proof of concept was demonstrated via experimental measurement with the intention of benchmarking progress.

A particulate model is developed to analyze the effects of steady state and transient seepage of water through a randomly-packed coarse-grained soil as an improvement to conventional seepage analysis based on continuum models. In the new model the soil skeleton and pore water are volumetrically coupled. In the first phase of the study, the concept of relative density has been used to define different compaction levels of the soil layers of a completely saturated pavement filter system and observe the seepage response to compaction. First, Monte-Carlo simulation is used to randomly pack discrete spherical particles from a specified Particle Size Distribution (PSD) to achieve a desired relative density based on the theoretical minimum and maximum void ratios. Then, a water pressure gradient is applied across one two-layer filter unit to trigger water seepage. The pore water motion is idealized using Navier Stokes (NS) equations which also incorporate drag forces acting between the water and soil particles. The NS equations are discretized using finite differences and applied to discrete elements in a staggered, structured grid. The model predicted hydraulic conductivities are validated using widely used equations. The critical water velocities, hydraulic gradients and flow within the xi saturated soil layers are identified under both steady state and transient conditions. Significantly critical transient conditions seem to develop. In the second phase of the study the model is extended to analyze the confined flow through a partly saturated pavement layer and unconfined flow from a retention pond into the surrounding saturated granular soil medium. In partly saturated soil, the water porosity changes resulting from water flow is updated using the Soil Water Characteristics Curve (SWCC) of the soil. The results show how complete saturation develops due to water flow following the water porosity Vs pressure trend defined by the SWCC. Finally, the model is used to predict the gradual reduction in the water level of a retention pond and the location of the free-surface. The free-surface is determined by differentiating the wet and dry zones based on the Heaviside step function modified NS equations.

Les supercondensateurs sont des dispositifs de stockage électrochimique de l’énergie très intéressants lorsque des pics de puissance sont mis en jeu. Toutefois, leur densité d’énergie volumique est la principale limite pour leur intégration, en particulier, dans des systèmes de transport terrestre. L’utilisation de matériaux d’électrode ayant un comportement pseudocapacitif et des masses volumiques élevées permettrait d’améliorer la densité d’énergie volumique des supercondensateurs. Avec cet objectif, des dispositifs à base des matériaux de la famille Ba0,5Sr0,5CoxFe1-xO3-δ, nommés BSCFs, ont été développés dans le cadre de cette thèse. Plusieurs compositions de cette famille d’oxydes ont été préparées par un procédé glycine-nitrate et ont été testés comme matériau actif d’électrode positive en milieu aqueux neutre. La capacité volumique de ces matériaux s’avère être beaucoup plus élevée que celle des carbones activés utilisés dans les supercondensateurs commerciaux. Elle a montré également dépendre de la composition en cobalt et en fer, du régime de charge, de la nature de l’électrolyte… Le mécanisme de stockage de charges dans ces matériaux a été exploré grâce à des techniques in situ (absorption des rayons X) et operando (diffraction des rayons X) effectuées aux synchrotrons SOLEIL (France) et SPring-8 (Japon). Enfin, des dispositifs associant une électrode positive à base de BSCF et du carbone activé ou FeWO4 en tant qu’électrode négative ont démontré l’intérêt d’intégrer de tels matériaux pour améliorer la densité d’énergie volumique des supercondensateurs. / Supercapacitors are attractive electrochemical energy storage devices for high power applications. However, volumetric energy density is the main limitation for their integration in such applications as terrestrial transport systems. The use of high density pseudocapacitive oxides as electrode material could lead to a volumetric energy density improvement. With this aim, materials from Ba0,5Sr0,5CoxFe1-xO3-δ family, so called BSCFs, have been studied. Several compositions have been prepared and evaluated as positive electrode materials in aqueous neutral electrolyte. Volumetric capacitances have shown to be greater than those of activated carbons, already used in marketed supercapacitors. They have also shown to depend on cobalt and iron ratio, charge rate, electrolyte composition... The study of the charge storage mechanism in these materials has been investigated thanks to in situ (X-Ray absroption spectroscopy) and operando (X-Ray diffraction) technics performed at SOLEIL (France) and SPring-8 (Japan) synchrotron facilities. Finally, devices coupling BSCF based positive electrode material with activated carbon or FeWO4 based negative electrode materials have demonstrated the added value of such materials to improve the volumetric energy density of supercapacitors.