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M. Tech. Civil Engineering / Asphalt mixes are commonly used for paving roads around the world. They consist of mainly bitumen and aggregate materials, which may differ depending on the type of asphalt mix. The shape properties of aggregate particles relevant for the performance of asphalt mixes include the form, angularity and surface texture. There are concerns about the standard test methods used to quantify the shape properties (i.e. angularity, surface roughness, flatness, elongation and sphericity) of aggregates used for road pavement design and construction. These test methods have been reported as time and labour intensive, and have several limitations including human error, lack of accuracy, and repeatability of test results. Although results obtained from these tests have been linked to performance, however these links are questionable. Recently, various researchers and practitioners have indicated that advanced and automated approaches such as imaging and laser scanning techniques would better quantify the shape and surface properties of aggregates. For instance, researchers at the Council for Scientific and Industrial Research (CSIR) found that a portable three-dimensional (3-D) laser scanning system can be used to accurately quantify the shape properties of aggregate particles that are relevant to the performance of asphalt mixes. The overall objective of this study was to use a 3-D laser scanning technique to quantify the shape properties of aggregate materials and relate them to performance of laboratory compacted asphalt mixes.

Aquatic organisms experience intermittent exposure to contaminants. The hazard from such discontinuous exposure may not simply be predicted from existing continuous exposure. Little is known about the bioaccumulation responses of shellfish to metals during intermittent compared to the continuous exposure counterparts. This study was designed to compare the bioaccumulation responses of two metals (Cd and Hg) singly (Chapters 3 and 4) or mixtures (Chapters 5 and 6) during continuous and intermittent exposure. Responses were examined using a multi-assay approach in areas of oxidative stress, osmoregulation, haematology and organ pathology. Tissue metal concentrations were highest in the gill and digestive gland for both metals. The linear or curvilinear pattern of accumulation was observed in the continuous exposure. While an alternating temporal uptake and clearance corresponding with the exposure was observed in the gill (Hg alone) and haemolymph (Cd alone) in intermittent profile. At the end, the study shows that accumulation of Hg or Cd was less in the intermittent compared to the continuous exposure for most tissue. Sub-lethal responses during Hg or Cd alone were similar in both regime apart from the severe pathology in the gill (continuous exposure) and inflammation in the digestive gland (intermittent exposure) observed in the Hg alone treatment (Chapter 4). For Hg plus Cd mixture, the additive effect in accumulation was observed in both exposures. Sub-lethal responses during mixtures were not affected in the intermittent. However, an antagonistic interaction was observed in the TBARS during continuous exposures for all tissues apart from the digestive gland. In terms of risk assessment, regulations for the single metals in continuous exposure will be protective for intermittent events at least for adult M.galloprovincialis.

Litopenaeus vannamei or Pacific white shrimp is the most widely farmed crustacean in the world. Shrimp are commonly fed feed containing 30-40% soybean meal or other plant-based feeds that are more economically and environmentally sustainable than animal-based feed. However, plant-based pellets are less palatable and less chemically attractive compared to animal material. Based on that, current research and practice includes the addition of specific marine animal meals in order to enhance palatability and attractability of plant-based shrimp feed. Yet, it is not sustainable or economically achievable to continue relying on marine animal meal. In the herein study, the effect of proprietary chemical mixtures designed by our research group as feed additives was examined based on their attractability and palatability in comparison to krill meal, a highly attractive and palatable supplement for shrimp feed. In palatability assays, total amount of pellets was measured before and after one-hour and three-hour periods of feeding in group-housed animals. In attractability assays, responses of shrimp were measured based on the number of probes and grabs on the source (airstone) of the stimulus being released. Each diet-set used contained different concentrations of krill meal and synthetic chemical mixtures. Results demonstrated these chemical mixtures enhance attractability and palatability of soybean based feed in L. vannamei when compared to krill meal. Furthermore, the addition of a proprietary mixture (= “premix”) improved responses in the attractability assays when compared to stimuli that did not contain the premix. Overall, results support the hypothesis that synthetic chemical mixtures can improve palatability and attractability of soybean meal based shrimp feed. This work could provide a reference for the development of synthetic chemoattractants and chemopallatants for the aquaculture of shrimp.

<p>Mass transfer in a porous solid, partially saturated with asingle solvent and multicomponent liquid mixtures, has beenexperimentally and theoretically studied. A porous materialcontaining single liquids and mixtures of organic solvents wasisothermally dried. Experiments were performed using a jacketedwind tunnel, through which a humidity andtemperature-controlled air stream flowed. The wetted porousmaterial was placed in a cylindrical vessel, whose top isexposed to the air stream until the material became dried to acertain extent. Drying experiments with the single solventswater, methanol, ethanol and 2-propanol, were performed atdifferent temperatures and transient liquid content profileswere determined. In isothermal drying experiments with liquidmixtures,the transient concentration profiles of thecomponents along the cylindrical sample as well as the totalliquid content were determined. The liquid mixtures examinedwere water-methanolethanol and isopropanol-methanol-ethanol.Two different temperatures and initial compositions were usedin the experiments. Mathematical models that describe nonsteadystate isothermal drying of a solid containing single liquidsand multicomponent liquid mixtures were developed. In the solidwetted with a single liquid, capillary movement of the liquidwas the main mechanism responsible for mass transfer. In thesolid containing liquid mixtures, interactive diffusion inliquid phase was superimposed to the capillary movement of theliquid mixture. In addition, interactive diffusion of thevapours in empty pores was considered. The parameters todescribe the retention properties of the solid and thecapillary movement of the liquid were determined by comparingtheoretical and experimental liquid content profiles obtainedduring drying of the solid wetted with single liquids. Tosimulate the transport of the liquid mixtures these parameterswhere weighed according to liquid composition. A fairly goodagreement between theoretical and experimental liquidcomposition profiles was obtained if axial dispersion isincluded in the model when the moisture consists of amixture.</p><p><b>Keywords:</b>Internal mass transfer, capillary flow,multicomponent, diffusion, solvent mixtures</p>

In risk evaluation, the effect of mixtures of environmental chemicals on a common adverse outcome is of interest. However, due to the high dimensionality and inherent correlations among chemicals that occur together, the traditional methods (e.g. ordinary or logistic regression) are unsuitable. We extend and characterize a weighted quantile score (WQS) approach to estimating an index for a set of highly correlated components. In the case with environmental chemicals, we use the WQS to identify “bad actors” and estimate body burden. The accuracy of the WQS was evaluated through extensive simulation studies in terms of validity (ability of the WQS to select the correct components) and reliability (the variability of the estimated weights across bootstrap samples). The WQS demonstrated high validity and reliability in scenarios with relatively high correlations with an outcome and moderate breakdown in cases where the correlation with the outcome was relatively small compared to the pairwise correlations. In cases where components are independent, weights can be interpreted as association with the outcome relative to the other components. In cases with complex correlation patterns, weights are influenced by both importance with the outcome and the correlation structure. The WQS also showed improvements over ordinary regression and LASSO in the simulations performed. To conclude, an application of this method on the association between environmental chemicals, nutrition and liver toxicity, as measured by ALT (alanine amino-transferase) is presented. The application identifies environmental chemicals (PCBs, dioxins, furans and heavy metals) that are associated with an increase in ALT and a set of nutrients that are identified as non-chemical stressors due to an association with an increase in ALT.

O Kraft 36EC® (i.a. abamectina) e o Score 250EC® (i.a. difenoconazol) são agrotóxicos intensamente utilizados nas culturas de morango em regiões de clima tropical, embora sejam compostos classificados como extremamente tóxicos e muito perigosos ao ambiente. Misturas de agrotóxicos são aplicadas nas culturas agrícolas e a presença destes compostos na água pode potencializar os efeitos tóxicos a organismos aquáticos não alvos. A ocorrência do escorrimento superficial (runoff) contaminado com agrotóxico e a contaminação por aspersão direta (spray drift) em ecossistemas tropicais próximo aos corpos hídricos também podem comprometer o ecossistema aquático local devido à toxicidade desses compostos a organismos não alvos. Considerando os riscos ecológicos inerentes ao uso destes agrotóxicos, o objetivo principal desta pesquisa foi avaliar o efeito ambiental dos praguicidas Kraft 36EC® e Score 250EC® e de seus princípios ativos, abamectina e difenoconazol, respectivamente. Foram realizados testes de toxicidade aguda em laboratório a partir de exposições dos compostos isolados e em misturas utilizando como organismo teste embriões e adultos de Danio rerio. Experimentos in situ (mesocosmos) foram realizados a fim de avaliar os efeitos do runoff e spray drift contaminados com os agrotóxicos Kraft 36EC® e Score 250EC®, isolados e em misturas. Tanto nos mesocosmos quanto em experimentos de laboratório analisou-se, além da mortalidade, biomarcadores bioquímicos. Pelos resultados obtidos verifica-se que não foram observadas diferenças significativas entre a toxicidade isolada dos ingredientes ativos e suas respectivas formulações comerciais em testes agudos. Nos testes de toxicidade com as misturas dos ingredientes ativos, observou-se que a mistura de abamectina + difenoconazol promoveu um efeito tóxico sinérgico a adultos de Danio rerio em exposições agudas. Observou-se também a ausência do mesmo efeito nas exposições com as misturas das formulações comerciais neste mesmo estágio de vida. A exposição dos embriões às misturas de Kraft 36EC® e Score 250EC® mostrou um efeito antagônico nas baixas concentrações e efeito sinérgico nas mais altas. Verificou-se um aumento significativo na atividade da enzima de biotransformação 7-etóxiresorufina-0-deetilase (EROD) e nos níveis de malondialdeído MDA nas brânquias de peixes expostos à formulação comercial da abamectina. Houve um aumento na atividade da glutationa-S-transferase (GST), glutationa peroxidase (GPx) e níveis de MDA, e diminuição da glutationa redutase (GR) nas brânquias dos peixes expostos ao difenoconazol e sua formulação comercial. Também foi observado um aumento nas respostas dos biomarcadores analisados nas brânquias dos organismos expostos às misturas tanto dos princípios ativos quanto das formulações comerciais. A exposição ao Kraft 36EC® spray drift em campo promoveu os maiores efeitos deletérios no metabolismo de Danio rerio, seguido das exposições ao runoff contaminado com Kraft 36EC® e Score 250EC®. As formulações comerciais Kraft 36EC® e Score 250EC® e as misturas das mesmas promoveram alterações significativas no metabolismo de detoxificação, e causam estresse oxidativo em peixes. Diferenças no padrão de respostas dos biomarcadores entre os experimentos realizados em mesocosmos e em laboratório ficam evidentes devido à influência das concentrações utilizadas, das interações ecológicas entre as comunidades presentes no meio e das variáveis ambientais nos experimentos em mesocosmos. A avaliação da toxicidade de agrotóxicos, especialmente em países tropicais, e indicações para futuras pesquisas são discutidos. / Kraft 36EC® (a.s. abamectin) and Score 250EC® (a.s. difenoconazole) are intensely used pesticides in strawberry crops in tropical regions, even though they are classified as extremely toxic and very dangerous to the environment. Mixtures of agrochemicals are applied to agricultural crops and the presence of these compounds in water may potentiate toxic effects to non-target aquatic organisms. The contamination of edge-of-field water bodies through runoff and spray drift may compromise the local aquatic ecosystem due to the toxicity of these compounds to non-target organisms. Considering the potential ecological risks related with the use of these pesticides, the main objective of this research was to evaluate the environmental effects of the pesticides Kraft 36EC® and Score 250EC® and its active ingredients abamectin and difenoconazole, respectively. Acute toxicity tests were performed in the laboratory with the isolated compounds and their mixtures using zebrafish (Danio rerio) embryos and adults as test organism. A mesocosm experiment was also performed to evaluate the effects of simulated runoff and spray drift containing Kraft 36EC® and Score 250EC® individually and in mixtures. Besides lethality, selected biomarkers were also evaluated in the fish from the mesocosm and laboratory experiments. No significant differences were observed in effects of the active ingredients and their respective commercial formulations in acute fish tests after single exposure to each test compound. The acute mixture toxicity tests with the active ingredients showed that this mixture exerts a synergistic toxic effect to adult fish. The absence of the synergistic effect on exposures with the commercial formulations mixtures was also observed. Embryo exposure to Kraft 36EC® and Score 250EC® mixtures showed an antagonistic effect at low concentrations and synergistic effect at the highest. A significant increase was observed in the activity of the EROD biotransformation enzyme and in the levels of MDA in fish gills after exposure to Kraft 36EC®. An increase in GST activity, GPx and MDA levels, and a decrease of GR in fish gills was noted after fish exposure to difenoconazole and its commercial formulation. An increase in the responses of the biomarkers analyzed in the gills of the organisms exposed to the mixtures of both the active ingredients and the commercial formulations as compared to single-compound exposure was also observed. Exposure to simulated spray drift of Kraft 36EC® in the mesocosms promotes the greatest deleterious effects on metabolism of Danio rerio followed by exposures to the runoff contaminated with a Kraft 36EC® and Score 250EC® mixture. The commercial formulations Kraft 36EC® and Score 250EC® and their mixtures lead to significant changes in the detoxification metabolism resulting in oxidative stress to fish. Differences in biomarkers responses between the experiments performed in the mesocosms and the laboratory were noted and are due to the different concentrations tested; the ecological interactions between the communities present in the mesocosms and differences in environmental variables. The need and indications for future research related with the evaluation of pesticide toxicity, especially in tropical countries, are discussed.

Esta pesquisa apresenta os resultados obtidos em análise laboratorial de misturas asfálticas de módulo elevado para aplicação em camada de base de pavimento. Historicamente, pode-se dizer que este tipo de mistura asfáltica em camadas de base resulta em melhor comportamento mecânico comparado com o de misturas asfálticas usinadas com CAP convencional. As misturas de módulo elevado apresentam vantagens em relação às convencionais com maior resistência à deformação permanente e maior vida de fadiga. Inicialmente, foram realizados ensaios laboratoriais de caracterização dos agregados e de três tipos de ligantes asfálticos: CAP A e CAP B, ambos ligantes duros com penetração entre 10 e 20dmm, e um CAP convencional, CAP 30/45. Foram dosadas três misturas asfálticas, com uma graduação preestabelecida, e com os três ligantes asfálticos estudados, pelos métodos Marshall e SUPERPAVE. Os teores de projeto pelo método Marshall foram de 0,2 a 0,3% superiores ao calculado pelo SUPERPAVE. Verificou-se o atendimento das especificações francesas quanto ao volume de vazios das misturas compactadas com os CAPs A e B pelo compactador giratório francês PCG). Foram determinados os danos por umidade induzida, tendo sido verificado que a mistura com CAP B requer um melhorador de adesividade. Determinaram-se os afundamentos por deformação permanente, as resistências à tração, os módulos de resiliência em dois equipamentos diferentes (MTS e UTM), os módulos dinâmicos, e a vida de fadiga por compressão diametral e por flexão em viga de 4 pontos, das três misturas asfálticas estudadas. As deformações permanentes para as misturas com CAP A e CAP B são menores que o limite máximo estabelecido pelas diretrizes europeias, e inferiores ao valor obtido com o mistura com CAP 30/45. Os módulos de resiliência mostraram rigidez distinta entre as misturas do módulo elevado, sendo que a mistura com CAP B é duas vezes mais rígida que a mistura com CAP A, que por sua vez é similar ao módulo com CAP 30/45. Obtiveram-se resultados similares de módulo de resiliência com equipamentos distintos. Os resultados dos ensaios de módulo dinâmico demonstraram proximidade de comportamento da mistura asfáltica com CAP A com misturas asfálticas com ligantes modificados; o módulo dinâmico da mistura com CAP B é similar àquele com CAP 30/45. Os resultados dos dois ensaios de fadiga empregados neste estudo demonstraram o melhor comportamento de misturas asfálticas compostas por ligantes duros e de módulo elevado, quando comparada com a mistura convencional. Todos os resultados demonstram que há benefícios de misturas de módulo elevado como camada de base em relação às misturas com CAP convencional, e que esta é uma solução com grande potencial para estruturas de pavimento para tráfego pesado. / This study presents the results obtained in laboratory analysis, about high modulus asphalt mixtures for use in base layer of pavement. Historically, it can be said that this type of mixture, when use in base layer, results in better mechanical behavior when compared with conventional asphalts. High modulus mixtures provide better behavior as it related layer`s permanent deformation and a higher fatigue life. Initially, laboratory tests for characterizing aggregates and three types of asphalt binders were carried out: Binder A and Binder B, both hard binders with penetration between 10 and 20dmm, and a conventional binder, namelly 30/45. Three types of asphalt mixtures were designed, with one predefined graduation and with those three asphalt binders, using Marshall and SUPERPAVE methods. Marshall`s binder contents were from 0.2 to 0.3% higher than SUPERPAVE. The compacted asphalt mixtures were in compliance with French specifications in terms of air void content of Binder A and Binder B using the French gyratory compactor (PCG). Moisture-induced damage test was performed and it was verified that Binder B needs an antistrip agent. Rutting, indirect tensile strength, resilient modulus in two different machines (MTS and UTM), dynamic modulus, and fatigue life by diametral compression and four point bending tests, were carried out with the three asphalt mixtures studied. The results of rutting for mixtures with Binders A and B were lower than the maximum limit of European specifications, and lower than the result with Binder 30/45. Resilient modulus showed different stiffness between the high modulus mixtures, where the asphalt mixture with Binder B was twice stiffer than the mixture with Binder A, which in turn is similar to the resilient modulus of the asphalt mixtures with Binder 30/45. Analogous results were observed in different resilient modulus machines. Dynamic modulus results showed similar behavior between the asphalt mixture with Binder A and asphalt mixture with modified binders; dynamic modulus of the asphalt mixture with Binder B was similar to the asphalt mixture with Binder 30/45. Results in the two fatigue tests were better for the asphalt mixtures with hard binders and high modulus in comparison with the conventional asphalt mixture. All the results demonstrate benefits of high modulus mixtures as base layer in pavements in comparison with asphalt mixtures with conventional binders, and the solution has a great potential in pavement structures for heavy traffic.

Ao longo de sua vida útil, com o acúmulo de tráfego e de solicitações ambientais, infraestruturas de transportes degradam-se em termos de desgaste dos seus componentes e deformações permanentes de suas camadas, acarretando na perda gradual da qualidade estrutural e funcional da via. A camada de sublastro, parte integrante da subestrutura ferroviária, possui contribuição significativa no comportamento mecânico global de uma via permanente. Suas principais funções estão relacionadas à drenagem, atenuação e distribuição de tensões, e separação e transição entre as camadas de lastro e subleito. O objetivo principal deste estudo foi comparar duas diferentes configurações de sublastro implementadas em uma ferrovia de carga brasileira através da medição de respostas mecânicas e parâmetros geométricos \"in situ\". O emprego de sublastro betuminoso constituiu-se como a primeira aplicação de campo deste tipo no País e ambas as seções foram monitoradas também por intermédio de sensores de temperatura e de tensão. Procedeu-se a caracterização física e mecânica dos materiais que compõem os trechos analisados em laboratório. Ademais, tensões de sucção foram medidas em diferentes locais e profundidades da camada de subleito, a fim de verificar a eficácia da camada betuminosa em impermeabilizar as camadas subjacentes. Os resultados mostraram uma eficiência global superior do trecho contendo sublastro betuminoso comparativamente à seção de referência (sublastro granular). Variações das tensões de sucção ao longo de duas estações climáticas mostraram que a mistura asfáltica protegeu satisfatoriamente o subleito quanto à infiltração de água oriunda das precipitações. Medidas de temperatura tomadas em diferentes pontos das camadas de sublastro mostraram que a mistura asfáltica se encontra protegida das variações térmicas e da incidência de radiação solar, uma vez que está isolada pela camada de lastro. Em termos de deslocamentos medidos com o equipamento DMD (Dispositivo para Medição de Deslocamentos), mostrou-se uma redução crescente no deslocamento vertical médio da seção com sublastro betuminoso em comparação com a seção com sublastro granular. Por consequência, o módulo de via, u, calculado para ambas as seções, revelou que o perfil contendo mistura asfáltica tende a defletir menos quando solicitado pela passagem de trens. Medidas de parâmetros geométricos utilizando o equipamento Trolley AMBER apontaram uma relação bidirecional entre o comportamento mecânico e a qualidade da geometria da via, observada antes e após intervenção mecanizada de socaria. / In the course of its service life, with traffic loading accumulation in addition to environmental effects, transportation infrastructures tend to degrade in terms of wear of their components and permanent deformation of their layers, resulting in the gradual loss of structural and functional quality of the railway. The subballast plays an important role as part of the railway substructure and it has a significant contribution to the overall mechanical behavior of the track. Its main functions are related to drainage, to load attenuation and distribution, and to the separation and transition between the ballast and the subgrade. The main objective of this study was to compare two different subballast configurations implemented in a freight railway profile in Brazil through measurements of mechanical and geometric parameters in field. The use of bituminous subballast was the first application of this type in the country and both sections were also monitored by means of temperature and pressure sensors. Laboratory tests for physical and mechanical characterization for all materials composing both experimental sections were performed. In addition, the water pressure in terms of suction were measured at different places and depths of the subgrade, in order to verify the effectiveness of the bituminous subballast in waterproofing the underlying layers. The results showed a superior overall efficiency of the section containing bituminous subballast compared to the reference section (granular subballast). The suction tension variation measured along two climatic seasons showed that the asphalt mixture satisfactorily protects the subgrade from the infiltration of water due precipitations. Temperature measurements taken at different points of the subballast layers showed that the asphalt mixture is protected from thermal and solar radiation peaks, since it is isolated by the ballast layer from atmospheric environmental effects. In terms of displacements acquired using the DMD (Displacement Measurement Device) it was observed an increasing reduction in the mean vertical displacement of the section with bituminous subballast compared to the section with granular subballast. Consequently, the track modulus, u, calculated for both sections revealed that the profile containing asphalt mixture tends to deflect less when requested by the train passage. Measurements of geometric parameters made with the Trolley AMBER device highlighted the bidirectional relationship between the mechanical behavior and the quality of the track geometry, observed before and after tamping procedure.

A finalidade deste trabalho e calcular a composição de modelos no FBST (the Full Bayesian Signicance Test) descrito por Borges e Stern [6]. Nosso objetivo foi encontrar um método de aproximação numérica mais eficiente que consiga substituir o método de condensação descrita por Kaplan. Três técnicas foram comparadas: a primeira é a aproximação da convolução de Mellin usando discretização e condensação descrita por Kaplan [11], a segunda é a aproximação da convolução de Mellin usando mistura de exponenciais, descrita por Dufresne [8], para calcular a convolução de Fourier mediante a aproximação de mistura de convoluções exponenciais, usando a estrutura algébrica descrita por Hogg [10], mais a aplicação do operador descrito por Collins [7], para transformar a convolução de Fourier para a convolução de Mellin, a terceira é a aproximação da convolução de Mellin usando mistura de exponenciais, descrita por Dufresne [8], para aproximar diretamente via mistura de exponenciais a convolução de Fourier, mais a aplicação do operador descrito por Collins [7], para transformar a convolução de Fourier para a convolução de Mellin. / The purpose of this work is to calculate the compositional models of FBST (the Full Bayesian Signicance Test) studied by Borges and Stern [6]. The objective of this work was to find an approximation method numerically eficient that can replace the condensation methods described by Kaplan. Three techniques were compared: First, the approximation of Mellin convolution using discretization and condensation described by Kaplan [11], second, the approximation of Mellin convolution using mixtures of exponentials, described by Dufresne [8], to calculate the Fourier convolution by approximation of mixtures of exponential convolutions, using the algebraic structure described by Hogg [10], and then to apply the operator described by Collins [7], to transform the usual convolution to Mellin convolution, third, the approximation of Mellin convolution using mixtures of exponentials, described by Dufresne [8], to calculate the Fourier convolution by direct approximation of mixtures of exponentials, and then to apply the operator described by Collins [7], to transform the usual convolution to Mellin convolution.