Thesis (M.S.)--University of Michigan, 1978.

Thesis (M.S.)--University of Michigan, 1962.

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2015. / Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2016-03-03T14:09:13Z No. of bitstreams: 1 2015_YuriPaulaLeitePaz.pdf: 5698092 bytes, checksum: b7eaefc9e7233f0332e4c45f3867147b (MD5) / Approved for entry into archive by Marília Freitas(marilia@bce.unb.br) on 2016-07-30T11:57:02Z (GMT) No. of bitstreams: 1 2015_YuriPaulaLeitePaz.pdf: 5698092 bytes, checksum: b7eaefc9e7233f0332e4c45f3867147b (MD5) / Made available in DSpace on 2016-07-30T11:57:02Z (GMT). No. of bitstreams: 1 2015_YuriPaulaLeitePaz.pdf: 5698092 bytes, checksum: b7eaefc9e7233f0332e4c45f3867147b (MD5) / As soluções de engenharia empregadas para prevenir ou conter a contaminação do solo e das águas envolvem, muitas vezes, a aplicação dos chamados liners, barreiras de baixa permeabilidade produzidas com materiais como argila compactada e geomembranas. Em várias situações de aplicação de liners, onde são esperadas baixas velocidades advectivas desenvolvidas, a difusão tem se mostrado extremamente relevante, sendo muitas vezes o principal mecanismo envolvido no transporte de contaminantes. A forma mais comum de determinação da componente difusiva do fluxo de contaminantes é pela realização do ensaio de difusão pura pelo método do reservatório único. Nesse ensaio, a aferição da variação da concentração ao longo do tempo de um contaminante em uma solução que se encontra em contato com uma amostra de solo saturada permite a determinação do coeficiente de difusão do contaminante no solo ensaiado. Não existe, no entanto, recomendação bem estabelecida para a forma de obtenção desse parâmetro a partir do ensaio e, comumente, utilizam-se soluções prontas ou implementadas em programas sem o devido conhecimento da sua aplicabilidade. A presente dissertação desenvolve e aplica uma solução semi-analítica da equação que descreve o transporte difusivo de contaminantes considerando as condições inicial e de contorno do principal ensaio de difusão pura utilizado. Para tal, a solução contaminante é contemplada no domínio de análise por meio de artifício que considera uma espessura de solo contaminado equivalente à solução. Em seguida, a solução desenvolvida é ajustada aos dados de ensaios reais realizados por Boscov (1997), Gurjão (2005) e Silveira (2014), de onde se conclui que os coeficientes de difusão obtidos pelo ajuste são coerentes, apresentando-se dentro do intervalo de ocorrência comum e abaixo do limite superior delimitado pelo coeficiente de difusão do contaminante em solução aquosa. Ajustes dos mesmos dados a outras soluções, que consideraram condições diferentes, permitiram verificar que algumas delas apresentam dificuldades para implantação, além de frequentemente retornarem valores do coeficiente inconsistentes. Por fim, realizou-se uma análise paramétrica que confirmou que o comportamento obtido pela nova solução proposta, chamada de solução da camada contaminada equivalente, é similar ao obtido para o ensaio de difusão pura e sugeriu que a definição de características adequadas do ensaio pode facilitar o ajuste para obtenção do coeficiente de difusão. / Engineering solutions applied to prevent or contain soil and water contamination often involves the application of liners, that are low permeability barriers made of materials such as compacted clay and geomembranes. In many liners applications, once reduced rates of seepage are expected, diffusion has proved to be a relevant, if not dominant, process of the contaminant transport. The most common way to measure the diffusive component of the contaminant flow is to conduct a single reservoir pure diffusion test. In this test a contaminant solution is placed above a saturated soil sample, and the drop in the source concentration over time is monitored allowing the diffusion coefficient of the contaminant in the tested soil to be determined. The method to infer this parameter from the test, however, is not standardized and often ready-made solutions or programs are applied without proper knowledge of their applicability. In this dissertation a semi-analytical solution of the equation describing the diffusive transport of contaminants is developed and implemented considering the initial and boundary conditions of the pure diffusion test. For this purpose, the contaminant solution is included in the analysis domain by the use of an artifice that considers a contaminated soil with a thickness that is equivalent to the solution height. Then, the developed solution was matched to some test data performed by Boscov (1997), Gurjão (2005) and Silveira (2014) and allows concluding that the diffusion coefficients obtained were consistent, with values contained in the main occurrence interval and below the upper limit defined by the diffusion coefficient of the contaminant in aqueous solutions. An adjustment of the same data to other solutions, which consider different initial and boundary conditions, have shown that some of them have a complex implementation and frequently returns inconsistent values of the coefficient. Finally, a parametric analysis was held and has confirmed that the behavior obtained by the presented new solution, named equivalent contaminated layer solution, is similar to the observed in pure diffusion. The parametric analysis also suggested that the adjustment for obtaining the diffusion coefficient can be optimized by the definition of the appropriate test characteristics.

The study of normal impedance of perforated plate acoustic liners including the effect of bias flow was studied. Two impedance models were developed, by modeling the internal flows of perforate orifices as infinite tubes with the inclusion of end corrections to handle finite length effects. These models assumed incompressible and compressible flows, respectively, between the far field and the perforate orifice. The incompressible model was used to predict impedance results for perforated plates with percent open areas ranging from 5% to 15%. The predicted resistance results showed better agreement with experiments for the higher percent open area samples. The agreement also tended to deteriorate as bias flow was increased. For perforated plates with percent open areas ranging from 1% to 5%, the compressible model was used to predict impedance results. The model predictions were closer to the experimental resistance results for the 2% to 3% open area samples. The predictions tended to deteriorate as bias flow was increased. The reactance results were well predicted by the models for the higher percent open area, but deteriorated as the percent open area was lowered (5%) and bias flow was increased. A fit was done on the incompressible model to the experimental database. The fit was performed using an optimization routine that found the optimal set of multiplication coefficients to the non-dimensional groups that minimized the least squares slope error between predictions and experiments. The result of the fit indicated that terms not associated with bias flow required a greater degree of correction than the terms associated with the bias flow. This model improved agreement with experiments by nearly 15% for the low percent open area (5%) samples when compared to the unfitted model. The fitted model and the unfitted model performed equally well for the higher percent open area (10% and 15%). / Ph. D.

Neste trabalho foi avaliado o desempenho de liners compostos frente a soluções de \'CU\'\'CL IND.2\'.2\'H IND.2\'\'O\'. Foram utilizados um solo argiloso compactado (CCL) da Formação Corumbataí (interior do estado de São Paulo) e um geocomposto bentonítico (GCL) de fabricação nacional. Quatro corpos de prova foram preparados para a realização do ensaio de percolação em coluna, sendo dois montados com CCL sobre GCL e outros dois com GCL sobre CCL. Os corpos de prova com configurações distintas foram submetidos à percolação de duas soluções de \'CU POT.2+\': uma com concentração de 0,024M e outra com 0,012M. Após o início da percolação da solução contaminante houve aumento da condutividade hidráulica, porém os valores mantiveram-se na ordem de \'10 POT.-11\' m/s, compatíveis com as exigências requeridas em diversas legislações ambientais. O liner composto mostrou-se mais eficiente como barreira de controle de fluxo comparado com Musso (2008), que estudou ambos materiais separadamente. A configuração dos liners não influenciou os valores de Rd obtidos, ao contrário da concentração das soluções. Observou-se que os resultados de Rd são inversamente proporcionais às concentrações utilizadas. Neste trabalho, os valores de Rd obtidos foram maiores que em Musso (2008), evidenciando a vantagem de se combinar diferentes materiais para a contenção de íons. / This research evaluated composite liners performance when permeated by \'CU\'\'CL IND.2\'.2\'H IND.2\'\'O\' solution. It were used a compacted clayey soil (CCL) samples from Formação Corumbataí (state of São Paulo) and a geosynthetic clay liner (GCL) manufactured in Brazil. Four specimens were prepared to column percolation tests. A pair of them was made with CCL on top of GCL and the other two with GCL on top of CCL. Specimens with different configurations were subjected to two \'CU POT.2+\' solutions: one with a concentration of 0,024M and other with 0,012M. Just after solution percolation began, there was an increase of hydraulic conductivity, but remaining around \'10 POT.-11\' m/s, in accordance with environmental laws. The composite liners demonstrated to be more efficient as barrier when compared to Musso (2008), which has analyzed both materials separately. The configuration of the liners did not influenced Rd values, unlike solutions concentration. It was observed that Rd results are inversely proportional to used concentrations. Rd values were larger than those obtained in Musso (2008), showing the advantage of matching different materials aiming ions retention.

Increased national and international travel over the lastdecades has caused an increase in the global number ofpassengers using different means of transportation. Greateffort is being directed to improving the noisy environment inthe residential community. This is to face the growing strictnoise requirements which are implemented by international noiseregulatory authorities, governments, and local airports. Thereis also a strong competition between different manufacturers tomake their products quieter. The propulsion system in anaircraft is the major source of noise during relevant flightconditions. The engine noise in a vehicle dominates the totalradiated noise at low speeds especially inside cities. Manyrecent studies on noise reduction involve the use of perforatedplates in the air and gas flow ducting connected to the engine.This thesis deals with the modelling of perforates as anabsorbent. There are many difficulties in using liners in theseapplications. The most important is that there is no largesurface area to which the linings may be applied. Equally, theenvironment in which linings have to survive is hostile.Therefore, liners have to be carefully tailored in order toachieve the most efficient attenuation. The full-scalesimulation testing, which is usually necessary to define thenoise attenuation produced by a liner installation, is bothtime-consuming and expensive. Therefore, a need for accuratemodels is a must. This thesis fills some gaps in the impedancemodelling of perforated liners. It also concentrates on thosecomplicated situations of sound propagation in ducts that weresolved earlier using Finite Element Methods. Alternateanalytical solutions to these problems are developed here,which gives more physical insight into the results. The key design parameter of perforates is the acousticimpedance. The impedance is what determines their efficiency toabsorb sound waves. A semi empirical impedance model wasdeveloped to be capable of accurately predicting the linerimpedance as a function of its physical properties and thesurrounding conditions. It was compared to all previous modelsin the literature. Nothing in the literature has been reportedon the effect of temperature on the perforate impedance,therefore a complete study was performed. A new inverseanalytical impedance measurement technique was proposed. It isbased on educing the impedance value based on the measurementof the attenuation across a lined duct section. Twoapplications were further considered: The effect of hard stripsin lined ducts on there attenuation properties; and themodelling of perforations in a complicated automotive mufflersystem. Keywords:Perforates–Liners–Acousticimpedance–Hot stream liners–Hard splices–Mufflers–Lined ducts–Collocation–Flowduct.

<p>Increased national and international travel over the lastdecades has caused an increase in the global number ofpassengers using different means of transportation. Greateffort is being directed to improving the noisy environment inthe residential community. This is to face the growing strictnoise requirements which are implemented by international noiseregulatory authorities, governments, and local airports. Thereis also a strong competition between different manufacturers tomake their products quieter. The propulsion system in anaircraft is the major source of noise during relevant flightconditions. The engine noise in a vehicle dominates the totalradiated noise at low speeds especially inside cities. Manyrecent studies on noise reduction involve the use of perforatedplates in the air and gas flow ducting connected to the engine.This thesis deals with the modelling of perforates as anabsorbent.</p><p>There are many difficulties in using liners in theseapplications. The most important is that there is no largesurface area to which the linings may be applied. Equally, theenvironment in which linings have to survive is hostile.Therefore, liners have to be carefully tailored in order toachieve the most efficient attenuation. The full-scalesimulation testing, which is usually necessary to define thenoise attenuation produced by a liner installation, is bothtime-consuming and expensive. Therefore, a need for accuratemodels is a must. This thesis fills some gaps in the impedancemodelling of perforated liners. It also concentrates on thosecomplicated situations of sound propagation in ducts that weresolved earlier using Finite Element Methods. Alternateanalytical solutions to these problems are developed here,which gives more physical insight into the results.</p><p>The key design parameter of perforates is the acousticimpedance. The impedance is what determines their efficiency toabsorb sound waves. A semi empirical impedance model wasdeveloped to be capable of accurately predicting the linerimpedance as a function of its physical properties and thesurrounding conditions. It was compared to all previous modelsin the literature. Nothing in the literature has been reportedon the effect of temperature on the perforate impedance,therefore a complete study was performed. A new inverseanalytical impedance measurement technique was proposed. It isbased on educing the impedance value based on the measurementof the attenuation across a lined duct section. Twoapplications were further considered: The effect of hard stripsin lined ducts on there attenuation properties; and themodelling of perforations in a complicated automotive mufflersystem.</p><p><b>Keywords:</b>Perforates–Liners–Acousticimpedance–Hot stream liners–Hard splices–Mufflers–Lined ducts–Collocation–Flowduct.</p>

Neste trabalho foi avaliado o desempenho de liners compostos frente a soluções de \'CU\'\'CL IND.2\'.2\'H IND.2\'\'O\'. Foram utilizados um solo argiloso compactado (CCL) da Formação Corumbataí (interior do estado de São Paulo) e um geocomposto bentonítico (GCL) de fabricação nacional. Quatro corpos de prova foram preparados para a realização do ensaio de percolação em coluna, sendo dois montados com CCL sobre GCL e outros dois com GCL sobre CCL. Os corpos de prova com configurações distintas foram submetidos à percolação de duas soluções de \'CU POT.2+\': uma com concentração de 0,024M e outra com 0,012M. Após o início da percolação da solução contaminante houve aumento da condutividade hidráulica, porém os valores mantiveram-se na ordem de \'10 POT.-11\' m/s, compatíveis com as exigências requeridas em diversas legislações ambientais. O liner composto mostrou-se mais eficiente como barreira de controle de fluxo comparado com Musso (2008), que estudou ambos materiais separadamente. A configuração dos liners não influenciou os valores de Rd obtidos, ao contrário da concentração das soluções. Observou-se que os resultados de Rd são inversamente proporcionais às concentrações utilizadas. Neste trabalho, os valores de Rd obtidos foram maiores que em Musso (2008), evidenciando a vantagem de se combinar diferentes materiais para a contenção de íons. / This research evaluated composite liners performance when permeated by \'CU\'\'CL IND.2\'.2\'H IND.2\'\'O\' solution. It were used a compacted clayey soil (CCL) samples from Formação Corumbataí (state of São Paulo) and a geosynthetic clay liner (GCL) manufactured in Brazil. Four specimens were prepared to column percolation tests. A pair of them was made with CCL on top of GCL and the other two with GCL on top of CCL. Specimens with different configurations were subjected to two \'CU POT.2+\' solutions: one with a concentration of 0,024M and other with 0,012M. Just after solution percolation began, there was an increase of hydraulic conductivity, but remaining around \'10 POT.-11\' m/s, in accordance with environmental laws. The composite liners demonstrated to be more efficient as barrier when compared to Musso (2008), which has analyzed both materials separately. The configuration of the liners did not influenced Rd values, unlike solutions concentration. It was observed that Rd results are inversely proportional to used concentrations. Rd values were larger than those obtained in Musso (2008), showing the advantage of matching different materials aiming ions retention.

A disposição final dos resíduos, de forma a minimizar a contaminação das águas, é feita, em geral, em aterros sanitários os quais devem apresentar na base camadas de argila compactada (CCL) que também são conhecidas como liners. Esses sistemas de barreiras desempenham funções diversas, dentre as quais se destacam o isolamento do resíduo e a diminuição da infiltração e a minimização da migração de contaminantes (filtragem, sorção e outras reações geoquímicas) em direção à água subterrânea. O objetivo deste trabalho foi avaliar os materiais argilosos relacionados à Formação Corumbataí com o intuito de selecionar os materiais que reúnem as melhores características para serem usados em liners compactados. Os aspectos avaliados foram a retenção de contaminantes por meio dos ensaios de equilíbrio em lote (batch test) e percolação em coluna com solução de CuCl2.2H2O, e avaliação da resistência à compressão simples do solo compactado, para suportar as cargas exercidas em um aterro sanitário. Para os cálculos dos parâmetros de adsorção utilizando o batch test, procedeu-se à construção e linearização das isotermas e, a partir do coeficiente de determinação, foi possível observar que os melhores ajustes foram com os modelos linear e de Freundlich. A isoterma de melhor ajuste para o cátion foi à de Freundlich em todas as amostras, destacando principalmente AM-2 e AM-16 com R² de 0,9983 e 0,9978 respectivamente. Na percolação em coluna os valores do fator de retardamento (Rd) para o Cl- e Cu++ foram determinados utilizando os métodos de Freeze e Cherry (1979) e Shackelford (1994) nas curvas de chegada. Na resistência à compressão simples a amostra mais significativa foi a AM-3 que resistiu uma força média de 992,1 N, chegando a uma tensão média de 477,4 kPa. Após uma análise integrada as amostras com maior desempenho foram AM-2 e AM-3, sendo que a AM-2 não foi apta apenas em um cenário elaborado para analisar a resistência à compressão simples. / The final waste disposal is usually the landfills. In order to minimize water contamination because of the waste, the landfills ought to have layers of clay compacted (CCL). Those layers are also known as liners. The barriers system has many functions, for instance, the isolation of the waste, the reduction of infiltration and also the reduction of contaminants migrations (filtering, sorption and other geochemical reactions) toward groundwater. This paper aims to evaluate the clay materials presents in Corumbataí Formation. The main objective was to select materials that have the best characteristics to be used in compacted liner. The aspects that were analyzed includes: the retentions of contaminants using batch test, and also column percolation with CuCl2.2H2O solution. It was also evaluated the resistance of the compacted soil to stand the loads exerted in a landfill. To calculate the adsorption parameters by using the batch test, the constructions and also the linearization of the isotherms were made, through coefficient of determination as its base. Because of those tests it was possible to identify that the best settings are the linear model and also the Freundlich model. The isotherm that presented the best adjustment for the cation was Freundlich isotherm. It was the best adjustment in all samples, mainly in AM-2 and also in AM-16 with R² of 0,9983 and 0,9978 respectively. In percolation column the values of retardation factor (Rd) for Cl- and also for Cu++, were determined by using Freeze and Cherry (1979) and also Shackelford\'s methods (1994) on breakthrough curves. In the \"compressive strength\", the most significant sample was AM-3 that resisted an average force of 992.1 N, reaching an average stress of 477.4 kPa. After an integrated analysis, the best samples were AM-2 and AM-3. However, the AM-2 was not able to work in a scenario that was created to analyze an unconfined compressive strength.

A disposição final dos resíduos, de forma a minimizar a contaminação das águas, é feita, em geral, em aterros sanitários os quais devem apresentar na base camadas de argila compactada (CCL) que também são conhecidas como liners. Esses sistemas de barreiras desempenham funções diversas, dentre as quais se destacam o isolamento do resíduo e a diminuição da infiltração e a minimização da migração de contaminantes (filtragem, sorção e outras reações geoquímicas) em direção à água subterrânea. O objetivo deste trabalho foi avaliar os materiais argilosos relacionados à Formação Corumbataí com o intuito de selecionar os materiais que reúnem as melhores características para serem usados em liners compactados. Os aspectos avaliados foram a retenção de contaminantes por meio dos ensaios de equilíbrio em lote (batch test) e percolação em coluna com solução de CuCl2.2H2O, e avaliação da resistência à compressão simples do solo compactado, para suportar as cargas exercidas em um aterro sanitário. Para os cálculos dos parâmetros de adsorção utilizando o batch test, procedeu-se à construção e linearização das isotermas e, a partir do coeficiente de determinação, foi possível observar que os melhores ajustes foram com os modelos linear e de Freundlich. A isoterma de melhor ajuste para o cátion foi à de Freundlich em todas as amostras, destacando principalmente AM-2 e AM-16 com R² de 0,9983 e 0,9978 respectivamente. Na percolação em coluna os valores do fator de retardamento (Rd) para o Cl- e Cu++ foram determinados utilizando os métodos de Freeze e Cherry (1979) e Shackelford (1994) nas curvas de chegada. Na resistência à compressão simples a amostra mais significativa foi a AM-3 que resistiu uma força média de 992,1 N, chegando a uma tensão média de 477,4 kPa. Após uma análise integrada as amostras com maior desempenho foram AM-2 e AM-3, sendo que a AM-2 não foi apta apenas em um cenário elaborado para analisar a resistência à compressão simples. / The final waste disposal is usually the landfills. In order to minimize water contamination because of the waste, the landfills ought to have layers of clay compacted (CCL). Those layers are also known as liners. The barriers system has many functions, for instance, the isolation of the waste, the reduction of infiltration and also the reduction of contaminants migrations (filtering, sorption and other geochemical reactions) toward groundwater. This paper aims to evaluate the clay materials presents in Corumbataí Formation. The main objective was to select materials that have the best characteristics to be used in compacted liner. The aspects that were analyzed includes: the retentions of contaminants using batch test, and also column percolation with CuCl2.2H2O solution. It was also evaluated the resistance of the compacted soil to stand the loads exerted in a landfill. To calculate the adsorption parameters by using the batch test, the constructions and also the linearization of the isotherms were made, through coefficient of determination as its base. Because of those tests it was possible to identify that the best settings are the linear model and also the Freundlich model. The isotherm that presented the best adjustment for the cation was Freundlich isotherm. It was the best adjustment in all samples, mainly in AM-2 and also in AM-16 with R² of 0,9983 and 0,9978 respectively. In percolation column the values of retardation factor (Rd) for Cl- and also for Cu++, were determined by using Freeze and Cherry (1979) and also Shackelford\'s methods (1994) on breakthrough curves. In the \"compressive strength\", the most significant sample was AM-3 that resisted an average force of 992.1 N, reaching an average stress of 477.4 kPa. After an integrated analysis, the best samples were AM-2 and AM-3. However, the AM-2 was not able to work in a scenario that was created to analyze an unconfined compressive strength.