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Composite liners are used in landfills to isolate solid waste from the local environment. The combination of a high-density polyethylene (HDPE) geomembrane and compacted clay liner (CCL) is commonly used worldwide. In the Ontario region, bentonite sand mixtures (BSMs) and the local clay i.e. Leda clay, can be considered as appropriate CCL materials. However, the interface failure between smooth HDPE and CCL is a critical issue for landfill safety. The shear stress behavior and strength parameters at the interface between the HDPE and CCL can be affected by many factors, such as temperature and chemicals. The temperature difference between winter and summer in the Ontario region is approximately 50°C, which causes a freeze-thaw (F-T) phenomenon in local landfills. Leachate and heat are generated during the solid waste stabilization process. Landfill leachate usually contains a high concentration of cations, which can carry heat, thus affecting the landfill liner properties. As a result, the interface shear stress behavior and strength parameters are affected by the aforementioned conditions. In this thesis, a series of experiments were conducted on the shear stress behavior at the interface of Leda clay / HDPE and bentonite sand mixture (BSM) / HDPE. In order to understand the influence of the F-T phenomenon, the samples were tested by varying the number of F-T cycles. Meanwhile, in order to understand the combined influence of cations and heat, the samples were saturated with different solutions, i.e. distilled water, potassium chloride and calcium chloride solutions. Then they were cured in an oven with different temperatures and room temperature, respectively. All of the laboratorial shear tests have been performed by using a direct shear machine. Results show that the BSM /HDPE and Leda clay/ HDPE interfaces are both influenced by the F-T cycles. The BSM/HDPE interface shear of the samples between 0 and 5 F-T cycles has more obvious differences, while the friction angle of compacted Leda clay/HDPE exhibits distinct reduction in the first 3 cycles, after which, the difference becomes hard to differentiate. The results also indicate that both high temperature and high concentration of cations from leachate can slight reduce the interface shear stress of BSM/HDPE. However, the combined influence of thermal-chemical conditions is not much more obvious compared to the effects of a single thermal or chemical condition. The BSM materials, which were saturated with different solutions, are also tested by using X-ray diffraction to examine the mineral changes in the BSM. The calcium and potassium cations convert sodium-bentonite into calcium-rich bentonite and illite/semectie mixtures, respectively. Nevertheless, the changess of clay part caused by the combined effect of heat and leachate have limited influence on the BSM/HDPE interface shear behavior.

The purpose of this study is to gain some first insights into the role of burst-like turbulent motions in sediment suspension over a sandy channel bed, during typical conditions of strong sediment transport with active bedforms. The focus is the suspension mechanism that maintains sizeable sediment concentrations away from the bed, where much of the downstream transport occurs, rather than entrainment at the sediment boundary itself. Flow components downstream and normal to the mean boundary, along with the output of an optical suspended sediment sensor, were monitored 1 m above the bed. The main study data were collected in a 10 m deep channel of the Fraser River near Mission, British Columbia, Canada. Velocities averaged 1.4 m/s at the surface and 0.9 m/s at the sensors, where mean suspended sediment concentrations were 500 mg/l; decimetre height small dunes on the backs of larger, metre amplitude dunes covered the channel bed. Many hours of data were recorded at 5 Hz, allowing multi-second scale turbulent motions as well as multi-minute oscillations to be resolved in both the velocity and turbidity records. Burst-like "ejection and inrush" motions were identified, producing a high degree of intermittency in momentum exchange: 80% of the mean Reynolds stress at the 1 m level is produced during 12% of the record duration. The burst recurrence period appears to be significantly greater than predicted by applying the conventional outer flow scaling in this environment. It is hypothesised that the non-uniform shear and pressure gradient conditions over the various scales of bedforms on the river floor may somehow affect mean burst periodicity, modifying the recurrence scaling developed over flat boundaries. The determination of a burst recurrence timescale from one-point data is inherently imprecise however and, as elsewhere, a continuous variation of return periods with relative magnitude of extreme (u'v') events is observed. The optical turbidity (OBS) time series reveals that these intermittent burst-like motions are, as expected, very important in vertically mixing sediments across the 1 m level in the flow; for example violent ejections, occurring only 1% of the time and contributing some 10% to mean turbulent momentum flux, appear to account for 6% of the total vertical sediment flux. The statistical association between the momentum and sediment mixing efficiencies of any ejection appears to be only moderately strong, however; very intense suspension can be associated with rather "weak" ejections (in terms of stress), and vice-versa. Differences between momentum and sediment mixing effects of a given ejection may partly be related to the "crossing trajectories effect"; sand grains continually fall out of the eddies that bear them, so the momentum and sediment "contents" of an eddy at 1 m off the bed are not perfectly linked. Turbulent sediment suspension is, like momentum exchange, a highly intermittent process in itself. After selecting turbulent events only for suspension efficiency, the largest ones, occupying only 5% of the time, contribute approximately one half of the total vertical sediment flux. There is no indication that the conventional scaling of burst recurrence corresponds to the occurrence of any distinctive event level for suspension. Interestingly, burst-like turbulent motions are not the only flow oscillations contributing to suspension in the high flow conditions of the study. Multi-minute period flow perturbations at 1 m off the bed significantly assist burst-scale turbulent motions in driving the upward sediment mixing. In summary, turbulent mixing of both momentum and sediment at 1 m over a typical sandy river bed is dominated by intermittent, intense "burst-like" events. However, the extrapolation of intermittent "bursting" concepts and structural constants from small-scale laboratory flows to the larger fluvial environment may be misleading. / Arts, Faculty of / Geography, Department of / Graduate

Orientador: Cláudio Casanova / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T11:03:53Z (GMT). No. of bitstreams: 1 CollaJacques_FernandaElisa_D.pdf: 17373999 bytes, checksum: 18adb4b65dc2639da145a80ed8b6f4e2 (MD5) Previous issue date: 2014 / Resumo: Flebotomíneos (Diptera: Psychodidae) são insetos de importância médico-veterinária pois participam do ciclo de doenças tais como leishmanioses, que acometem milhares de pessoas ao redor do mundo. O conhecimento sobre a ecologia e biologia desses dípteros é de fundamental importância para determinar a capacidade e competência vetorial de suas populações, e portanto, relevantes do ponto de vista da saúde pública. Este trabalho buscou esclarecer alguns pontos com informações deficientes sobre a biologia e ecologia das espécies vetoras de Leishmania (Leishmania) infantum chagasi e Leishmania (Viannia) braziliensis, respectivamente, Lutzomyia longipalpis e Nyssomyia neivai, no estado de São Paulo. Para a leishmaniose visceral americana (LVA), objetivou-se esclarecer questões a respeito de criadouros urbanos preferenciais de Lu. longipalpis e sobre sua expansão geográfica no estado de São Paulo. Em referências às lacunas no conhecimento da ecoepidemiologia da leishmaniose tegumentar americana, a competência vetorial de Nyssomyia neivai para L. (V.) braziliensis e o estudo da composição da comunidade flebotomínica em área endêmica no nordeste do estado, bem como sua variação mensal. Criadouros de Lu. longipalpis foram encontrados predominantemente em ambientes sombreados com grande quantidade de matéria orgânica, com maior concentração de larvas associadas a galinheiros. Quanto à sua dispersão, esta parece ter seguido uma rota a partir de Mato Grosso do Sul, seguindo em direção oeste-leste e também para norte e para sul a partir dessa linha central. A ocorrência de casos de LVA em humanos frequentemente é precedida pela detecção de Lu. longipalpis e casos caninos. Nyssomyia neivai, bastante frequente em áreas endêmicas para LTA no vale do Rio Mogi Guaçu, mostrou-se competente para adquirir, manter e transmitir o parasito em condições laboratoriais, cumprindo assim mais uma etapa necessária para a sua incriminação como espécie-vetora. Ainda no vale do rio Mogi Guaçu, a comunidade de flebotomíneos mostrou-se bastante diversa, com 17 espécies, das quais cinco são importantes para o ciclo da LTA. A fauna flebotomínica encontrada era composta majoritariamente por Nyssomyia whitmani, Migonemyia migonei e Expapillata firmatoi e, mais uma vez, abrigos para animais, tais como galinheiros, foi o local preferido para estes insetos, onde a sua maioria foi capturada. Desta forma, este trabalho apresenta dados relevantes para o conhecimento a respeito desses insetos vetores, que podem ser usados como base para futuros projetos ou no desenvolvimento de novas estratégias de controle dessas doenças / Abstract: Phlebotomine sandflies (Diptera: Psychodidae) are insects of medical and veterinary importance because they take part in the cicle of diseases, such as leishmaniasis which affect thousands of people around the world. Learning about these dipteras¿s ecology and biology is fundamentaly important to define the vectorial capacity and competence of their populations, and therefore, relevant for the public health perspective. This study aimed at adressing some issues with deficiente information on the biology and ecology of vector species of Leishmania (Leishmania) infantum chagasi and Leishmania (Viannia) braziliensis, respectively, Lutzomyia longipalpis and Nyssomyia neivai, in São Paulo State. For the American visceral leishmaniasis (AVL), this paper tried to answer questions on the preferencial breeding site of Lu. longipalpis and its geographical expantion in São Paulo State. In relation to the knowledge of the ecoepidemiology of American cutaneous leishmaniasis (ACL), the vectorial competence of Nyssomyia neivai to L. (V.) braziliensis and the analysis of the sandfly community in and endemic area in the Northeast of the state were studied. Lutzomyia longipalpis breeding sites were found predominantly in shaded environments with great amount of organic matter, and the greatest concentration of larvae associated to chicken sheds. Considering its dispersion, Lu. longipalpis seemed to follow a route from Mato Grosso do Sul to São Paulo city, in a west to east direction and from that central line, an expansion to the north and south. The occurance of human AVL is generally preceded by the detection of Lu. longipalpis and canine cases. Nyssomyia neivai, frequently found in endemic áreas for ACL in the Mogi Gauçu River Valley, was shown to be competente to aquire, host and transmit the parasite under laboratory conditions, thus fulfilling another requirement to be recognized as a vector species. Still in Mogi Guaçu River Valley, the sandfly community was greatly diverse, comprised of 17 species, of which five are considered important for the ACL cicle. The sandfly fauna was mainly comprised of Nyssomyia whitmani, Migonemyia migonei and Expapillata firmatoi and, once again, animal shelters, such as chicken sheds, were the preferred site for these insects, where the greatest amount was collected. Therefore, this work presents relevant data for the knowledge on these vector insects, which can be used as basis for future projects or in the development of new control strategies against these diseases / Doutorado / Relações Antrópicas, Meio Ambiente e Parasitologia / Doutora em Biologia Animal

A falta de regulamentação ambiental no passado levou muitas indústrias, incluindo as de fundição (geradoras de grandes quantidades de areia de fundição), a destinarem seus resíduos de forma inadequada ao longo dos anos, criando passivos ambientais que perduram até hoje. A periculosidade destes passivos muitas vezes não está diretamente ligada à periculosidade dos resíduos depositados, pois acredita-se que ao longo dos anos, sob a ação do intemperismo, muitas reações químicas ocorrem levando à mobilidade dos elementos químicos presentes no depósito de resíduos. Este trabalho propõe avaliar o comportamento de um depósito de resíduos de areia de fundição não controlado, com mais de 30 anos e a mobilidade de elementos inorgânicos potencialmente tóxicos ao longo de um perfil vertical do depósito, como parte da gestão ambiental de uma área impactada. Para este objetivo foram utilizadas ferramentas como análise de umidade, análise granulométrica, análise morfológica por MEV, análise química qualitativa e quantitativa por MEV-EDS e por FRX. Os elementos químicos analisados foram divididos em grupos de forma a encontrar similaridades. A partir dos resultados obtidos foi possível concluir que os alcalinos, alcalinos terrosos, calcófilos e alguns litófilos (Al, Zr, P, Mn, Ti e V) migraram para a base do perfil e o comportamento do depósito de resíduos pode ser comparado ao comportamento diagênico clássico de evolução pedológica de perfis de solo em rochas em condições tropicais. Além disso, do ponto de vista micromorfológico, granulométrico e químico esse depósito de resíduo não é o mesmo ao longo do perfil vertical escavado e a divisão em blocos (base, meio e topo) só é verificada na análise granulométrica. E, apesar do resíduo ADF não ser considerado classe I, o mesmo pode apresentar risco ao meio ambiente quando depositado em locais não controlados e submetidos a condições climáticas supérgenas tropicais. / The lack of environmental regulation in the past has led many industries, including foundries (that generates large amounts of foundry sand), to place their waste improperly over the years, creating environmental passives that endure today. The danger of these passives is often not directly related to the dangerousness of waste landfilled because it is believed that over the years, under the action of weathering, many chemical reactions occur leading to mobility of chemical elements present in the waste deposit. This work proposes to evaluate the behavior of an uncontrolled waste foundry deposit, with more than 30 years, and the mobility of potentially toxic inorganic elements along a vertical profile of the deposit as part of the environmental management of an impacted area. For this purpose were used tools such as humidity analysis, granulometric analysis, morphological analysis by Scanning Electron Microscopy (SEM), qualitative and quantitative chemical analysis by SEM with Energy Dispersive X-ray Detector (EDX) and X-ray Fluorescence. The chemicals analyzed were divided into groups in order to find similarities. From the results obtained it was concluded that the alkali, alkaline earth, chalcophile and some lithophile (Al, Zr, P, Mn, Ti e V) migrated to the base of the profile and behavior of the waste deposit can be compared to the classic diagenic behavior of pedological evolution of soil profiles in rocks in tropical conditions. Furthermore, from the standpoint of micromorphology, particle size and chemical this waste deposit is not the same along the vertical profile excavated and the three divisions (base, middle and top) is only checked on granulometric analysis. And despite the foundry sand residue is not considered class I, it may present a risk to the environment when deposited in non-controlled area and subject to tropical supergens weather conditions.

With global warming on the rise and the urge for conserving our natural resources, it becomes very important that proper steps are taken to protect our natural resources and utilize them efficiently. Forest fires are one of the many issues on the charts towards protection of natural resources. The catastrophic aftermaths caused by forest fires are known to all. The causes for these fires could be known/unknown natural causes or human intervention. Remote sensing techniques use the electromagnetic radiation in the RF/Microwave region, emitted from an object. The amount of energy emitted from an object depends on its present conditions, primarily its temperature and its emissivity. The sensing devices used in such measurements are classified into active and passive sensors. Herein, passive radiometry is used to investigate a model for the propagation of subsurface radiation from underground forest fires through upper ground layers of soil till the land-air interface. Passive radiometry involves capturing the radiation incident on a radiometer antenna aperture directly or deflected from several objects. The energy emitted from sources above 0K is collected and is compared with the calibration standards to estimate the physical quantity under test. Detecting forest fires is one of the potential applications of passive radiometry investigated here.

Dwindling conventional oil resources has caused exploration efforts to focus elsewhere. Bitumen from oil sands has emerged as one of the primary unconventional oil resources in use today. Quadrise Canada Corporation has harnessed this unconventional oil by developing their bitumen-in-water emulsion known as MSAR (Multi-Phase Superfine Atomized Residue). Fuel-in-water emulsions are linked to a combustion phenomenon known as micro-explosion, which are associated with an increase in combustion efficiency and decrease in harmful emissions. A study has been conducted of the MSAR fuel to help advance the optimization and modeling of its use in spray combustors so as to best harness the potential. Quantitative and qualitative data has been obtained during combustion experiments of the fuel that will attribute to this end. Additionally, a simplified statistical model is presented based on the governing equations to describe the atomization that occur as a result of micro-explosions of the MSAR fuel as well as a simple model to represent internal force needed for a micro-explosion to occur. The results of this study continue to reinforce the understanding that micro-explosions cannot be attributed to one overriding physical principal, but rather are th result from variations in turbulent, dynamic, and thermal forces.

Silica sand is used in the hydraulic fracturing process as a proppant—a material that holds open fissures in a rock formation to allow oil and gas to escape. Due to the increased demand for proppant sand, numerous sand mining and processing facilities have been constructed in the vicinity of small communities. Silica sand contains crystalline silica, which can cause chronic health problems such as silicosis. This study monitored airborne particulate matter at residences within 800 m from the facilities property line, with active mining, processing, and/or transport. Real-time particulate air monitoring with automated acquisition of explanatory variables: sound and motion to detect transportation; and wind speed and direction to attribute measured PM concentrations to specific sources. The highest daily mean concentrations were 37.3 μg/m3 for PM10 and 14.5 μg/m3 for PM2.5, both of which are well below the EPA National Ambient Air Quality Standards. Using conditional probability plots of PM relative to wind direction elevated short-term (20 second) peak concentrations were more likely to occur when the wind was blowing from the sand facility. These peak concentrations occurred infrequently, ranging from 0% to 3% of the sampling time. This study did not measure crystalline silica specifically, but low PM concentrations were observed so crystalline silica is expected to be low. Since PM concentrations were low near the facilities, it can be concluded that these facilities do not increase airborne particulate matter to hazardous concentrations that could cause chronic health conditions.

Peat is one of the most important materials used for soil amendment in commercial horticulture. Traditionally, sphagnum peat has been the dominating form of peat used, but other forms of peat may also prove to be of great use. Sometimes, peat must be removed from restored wetlands in order to create more open patches of water. This offers a potential to use the removed peat for something productive. In this study, it was examined if peat made up from Cladium sp. could be used to mix with a sand soil to gain a higher yield of crops. Corn were planted in sand soil containing varying amounts of peat mixed in. The crops were then allowed to grow for around 50 days before harvest. After harvesting, it was found that the yield was higher from the crops that had been growing in a soil that had some amount of peat mixed in with the sand. Further large-scale studies could determine if this could be used as an economic and sustainable alternative to sphagnum peat.

<p>In the last two decades, there has been significant improvements in pile design methods. These methods include variables that have been studied using laboratory and full-scale experiments. Refined understanding of the underlying mechanisms controlling pile response to loading enables introduction of variables in the design equations that reflect observations made in high-quality experimental data.</p><p>The mechanisms involved in the mobilization of the pile resistance (both base and shaft resistance) are studied in this thesis using a large-scale model pile testing facility consisting of a half-cylindrical calibration chamber with image analysis capabilities, instrumented model piles, and data and digital image acquisition systems. The thesis focuses on the effect of the pile surface roughness on the mobilization of tensile shaft resistance, the effect of the pile base geometry on the mobilization of base resistance, the analysis of possible mechanisms responsible for time-dependent increases in pile axial capacity, and particle crushing produced by pile installation. </p><p>A set of model pile tests were performed to study the effects of three different surface roughnesses on the shaft resistance of model piles jacked in the half-cylindrical calibration chamber. Digital images of the model piles and surrounding sand captured during tensile static loading were analyzed using the digital image correlation (DIC) technique. The base and shaft resistance measured for the instrumented model piles and the displacement and strain fields obtained with the DIC technique show that an increase in the roughness of the pile shaft results in an increase in the average unit shaft resistance and in the displacements and strains in the sand next to the shaft of the pile. Guidance is provided for consideration of pile shaft surface roughness in the calculation of the tensile limit unit shaft resistance of jacked piles in sand.</p><p>Base geometry effects were studied using jacked and pre-installed model piles with flat and conical bases tested in the DIC calibration chamber. The results show that the mobilized base resistance of a model pile with a conical tip was less than that of an equal pile with a flat base, all other things being equal, by a factor ranging from 0.64 to 0.84. The displacement and strain fields obtained with DIC also show that the slip pattern below the pile with a conical base differs from that of a pile with a flat base. </p><p>Finally, the degree of crushing of silica sand particles below the base of model piles jacked in sand samples is studied. The particle size distribution curves are obtained before and after pile installation. Relationships between the load mobilized at the base of the model piles and two well-known breakage parameters are proposed. This work also provides detailed measurements of the trajectories followed by crushed and uncrushed particles during pile installation, and characterizes the typical particle crushing modes produced by piles jacked in silica sand.</p><div><br></div>