Esta tese tem por objetivo analisar o comportamento mecânico de um solo coluvionar de arenito não saturado (Solo AV) em condições indeformadas e remoldados. Sua localização é na divisa dos estados de Santa Catarina e Rio Grande do Sul. Os corpos de prova foram moldados com o mesmo índice de vazios na condição indeformada e na condição remoldada com o intuito de se avaliar o papel da estrutura deste solo. Para este estudo foi modificado o equipamento triaxial com sucção controlada, apresentado por Pereira (2006), inserindo os medidores de deslocamentos locais nos corpos de prova (sensores de efeito Hall). A partir dos medidores de deformação locais foi possível observar a influência da sucção nos módulos de deformabilidade do solo AV para a condição remoldada. Foram determinadas as envoltórias de resistência ao cisalhamento para os ensaios na condição não saturada para corpos de prova indeformados e remoldados. Na condição não saturada observou-se que o ângulo de atrito interno (’) é influenciado pelo nível de sucção e tensão normal líquida aplicada. As envoltórias no plano tensão cisalhante versus sucção são não lineares e resultam, para baixos valores de sucção, em valores de b sempre superiores a ’. Os resultados indicaram que os corpos de prova indeformados, na condição saturada, apresentaram parâmetros e resistência ao cisalhamento superiores aos corpos de prova remoldados. Entretanto, para a condição não saturada, os corpos de prova remoldados apresentaram resistência ao cisalhamento superiores a dos corpos de prova indeformados. Os resultados dos ensaios do hollow cylinder indicaram que a magnitude da tensão principal intermediária influencia na resistência ao cisalhamento obtida. Pela variação da direção da tensão principal maior observou-se um comportamento anisotrópico nos corpos de prova remoldados. Em termos de parâmetros de resistência ao cisalhamento os ensaios triaxiais e hollow cylinder apresentaram resultados consistentes, de acordo com a literatura. Os principais modelos de previsão de resistência ao cisalhamento existentes, baseados em dados básicos do Solo AV, não apresentaram um bom ajustes para as condições de moldagem. Baseado em análises estatísticas, foi possível obter duas equações de ajuste, sendo uma linear exponencial para a condição indeformada e uma parabólica para a condição remoldada. / This thesis aims to analyze the mechanical behavior of an unsaturated sandstone colluvium soil (Soil AV) in undisturbed and remolded conditions. The colluvium is located on the border of the states of Santa Catarina and Rio Grande do Sul. The specimens were prepared with the same void ratio for undisturbed and remolded conditions in order to evaluate the soil structure. For this study the triaxial apparatus with suction-controll, presented by Pereira (2006), was improved by inserting local displacement traducers (Hall effect sensors). These tranducers allowed the evaluation of the influence of the suction on the Young’s modulus for the soil AV in the remolded condition. Shear strength envelopes were determined based on tests on unsaturated condition on undisturbed and remolded specimens. For the unsaturated condition, it was noted that the internal friction angle ('’) is influenced by the level of suction and net normal stress applied. The shear envelopes on the shear stress versus suction plane are nonlinear and showed b higher than ’, for low suction values. The results showed that undisturbed specimens in saturated conditions presented shear strength parameters and shear strength higher than the remolded specimens. However, in the unsaturated condition the remolded specimens showed higher shear strength than undisturbed specimens. The Hollow Cylinder test results indicated that the intermediate principal stress has influence on shear strength of the soil. By varying the direction of major principal stress it was noticed an anisotropic behavior in the remolded specimens. In terms of shear strength parameters triaxial and hollow cylinder tests presented consistent results as it was observed in the literature. Some of the models used to predict the shear strength, based on basic parameters of the soil AV, have not shown good matches for both, undisturbed and remolded conditions. Based on statistical analysis, it was possible to obtain two adjustment equations being a linear exponential to the undisturbed conditions and a parabolic for the remolded condition.

Colon cancer is a leading cause of cancer related deaths worldwide. Lifestyle factors such as diet and exercise have been implicated as important agents in colon cancer development and progression. Epidemiological, in vivo and in vitro studies have found that n-3 polyunsaturated fatty acids (PUFAs) reduce colon carcinoma. The role of n-6 PUFAs remains a controversial topic, with studies indicating both promoting and preventing capabilities published. In order to better understand the effects of PUFAs on colon carcinoma, it is important to have an understanding of how they will be broken down in the body. During this study, in silico metabolism of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) predicted the formation of hydroxy-, di-hydroxy- and epoxy-FAs. A gas chromatography-mass spectrometry method was developed and validated for the detection of these PUFAs and their cytochrome P450 (CYP) metabolites. A human liver microsomal system for the in vitro metabolism of EPA, DHA and AA was optimised in terms of microsomal and PUFA concentration. The system resulted in the metabolism of the positive control, lauric acid, to 12-hydroxy-lauric acid but was unable to metabolise the PUFAs of interest. EPA, DHA and AA reduced cell viability in the colon carcinoma cell lines SW480 and SW620 in the micromolar concentration range (25 – 200 μM). The CYP epoxidation metabolite of EPA, 17, 18-epoxyeicosatetraenoic acid (17, 18-EpETE) resulted in a significant reduction in SW480 cell viability relative to the parent compound at lower concentrations (25 and 50 μM). Annexin V apoptosis analysis revealed that EPA and 17, 18- EpETE did not result in apoptosis in SW480 cells at a concentration of 25 μM and over an incubation period of 24 hours. A significant reduction in reactive oxygen species production was seen in SW480 cells after incubation with 25 μM 17, 18-EpETE for 24 hours. EPA and 17, 18-EpETE were implicated in the reduction of colon cancer metastasis since they were able to reduce SW480 migration and anchorage independent cell growth. These results indicate that the dietary intake of EPA, DHA and AA may be beneficial to one’s health due to the negative effects that these PUFAs had on colon carcinoma. Future studies are needed to confirm these benefits and compare the effects of the PUFAs to their CYP-metabolites.

The effect of different blanching treatments and packaging materials on the enzymatic (lipoxygenase and peroxidase) activity and fatty acid stability of two different varieties of sweet corn on the cob (Jubilee and GH 2684) was evaluated during nine months of frozen storage at -23.3°C. The initial moisture content in the kernels of the two sweet corn varieties averaged 72.5%. After nine months of frozen storage the moisture content in the kernels of corn depended greatly on the packaging material used. The ears stored in Cryovac B and E bags showed the best moisture retention (72.2% final moisture content), followed by the polyethylene bags (71.4%) while the ears stored without packaging material showed severe dehydration (70.1%). The peroxidase and lipoxygenase activities were determined using spectrophotometric assays on a crude extract obtained from liquid nitrogen powdered corn. Both unblanched varieties of sweet corn showed similar initial peroxidase specific activity and general behavior during the nine months of frozen storage. The presence of lipoxygenase isozymes with different thermal stabilities in both varieties was suggested by the higher lipoxygenase specific activity found in Jubilee after freezing and nine months of frozen storage (0.135 units/mg protein) compared with the GH 2684 variety (0.115 units/mg protein). Complete inactivation of lipoxygenase was obtained after 9 minutes steam blanching at 100°C. Peroxidase was more heat resistant showing some remaining specific activity after 9 minutes steam blanching with a complete inactivation after 15 minutes steam blanching. No regeneration of either enzyme was observed during the nine months of frozen storage suggesting a permanent disruption of the active site of both enzymes. Relative fatty acid content was determined by gas chromatographic analysis of fatty acids methyl esters. The major fatty acids present in both varieties were palmitic (14.93%), stearic (2.79%), oleic (31.54%), linoleic (46.87%) and linolenic (1.89%) acids. Good stability of the polyunsaturated fatty acids was observed during the nine months storage at -23.3°C, with autoxidation as the main mechanism responsible for the decrease in the relative percent of polyunsaturated fatty acids. Some enzymatic oxidation also occurred, decreasing the linolenic acid content. The control of the degradation of polyunsaturated fatty acids depended mostly on the frozen storage temperature (-23.3°C) and not on the oxygen permeability of the different packaging materials. The results obtained in our study suggested that blanching of the ears of sweet corn had an important effect on reducing the enzyme activity but little effect on the polyunsaturated fatty acid degradation after 9 months of storage at -23.3°C. / Graduation date: 1994

Chloride concentrations at the Greenbrook well field in Kitchener, Ontario, have been steadily increasing over the past several decades and may soon pose a threat to drinking water quality. Drinking water limits at some wells have already been exceeded. The Regional Municipality of Waterloo (RMOW) relies mainly on local groundwater resources for its drinking water supply, and the Greenbrook well field is the oldest of 50 municipal well fields contributing to this supply. Urban growth and the expansion of city limits over the years has surrounded the well field, placing it in a high risk area in need of protection. As such, protection of this water supply is essential until alternative sources can be found. Road salt has been identified as the prime source of the chloride contamination, and various management alternatives and remediation strategies are currently being studied. In order to characterize the behaviour of chloride in the subsurface, an understanding of the mechanisms that control travel of chloride to the water table and through the groundwater system is needed. For the first phase of this work, a 2-D variably-saturated flow and transport model (SWMS-2D) was used to evaluate the effect of seasonal fluctuation in chloride loading to a generic aquifer system. Chloride was applied over the surface of the model in seasonal pulses that correlated with temperature and precipitation. The model showed a dampening of the seasonal response with depth that lead to the conclusion that long-term transport models can neglect seasonal changes in solute loading. For the second phase of this work, a proven 3D finite element transport model (Waterloo Transport Code: WTC) was used to simulate road salt impacts to the well field. Road salt was applied over selected roads throughout the steady-state capture zone via a type 3 (Cauchy) boundary that varies both temporally and spatially with road type and location. After calibrating the model from 1945 to 2002 to chloride concentrations using the weighted average of 5 Greenbrook production wells, the model was run to the year 2041 to assess future implications. Remediation strategies were also investigated via 6 predictive scenarios in which chloride applications were reduced by varying degrees. The results of this phase will be used by the RMOW in cost-benefit analyses of alternative de-icing approaches versus de-chlorination treatment of the well water.

Preliminary data from studies in rodents suggests time-dependent associations between dietary LC n-3 PUFA and hepatic levels of the enzyme soluble epoxide hydrolase (sEH), which regulates the metabolism and availability of epoxyeicosatrienoic acids (EET).  EET are cytochrome P450 epoxygenase products of arachidonic acid associated with  lower blood pressure, decreased inflammatory response and inhibition of blood coagulation. To further investigate the association between LC n-3 PUFA and sEH, ApoE^-/^- mice were fed a high-fat high-cholesterol diet supplemented with either fish oil (EPA + DHA) or DHA or HOSF (all 2% w/w) for 10 weeks and livers and aortic roots were collected on day 2 and weeks 1, 2, 4 and 10.  Proteomics analysis showed an overall decreasing effect of fish oil (but not DHA) supplementation on hepatic protein levels of sEH compared to the control throughout the intervention period (<i>P</i> &lt; 0.05).  Neither fish oil nor DHA intervention affected atherosclerotic plaque size in the aortic root. We also examined how dietary supplementation with 1 g/day EPA or 1 g/day DHA for 10 days affects platelet sEH levels and platelet aggregation compared to 1 g/day HOSF (control) in healthy volunteers in a double-blind, placebo-controlled, cross-over trial.  We found that DHA decreased platelet aggregation by 10% (<i>P =</i> 0.04) and EPA also inhibited ADP (5 μM)-induced platelet aggregation by 14% compared to the control group but this effect did not reach statistical significance due to high variability between subjects.  EPA decreased platelet sEH levels by 25% (not significant), whereas DHA had no effect.  We also attempted to optimize a method for measuring EET in plasma and platelets.  However, the rapid conversion of EET to other compounds and their low concentration in tissues prevented us from optimizing such a method within the time limits of the project.

Typescript, etc. / Digitized by Kansas Correctional Industries

Water infiltration associated with natural precipitation events or other artificial activities such as pipe leaks in expansive soils significantly influence the engineering properties; namely, coefficient of permeability, shear strength and volume change behavior. For this reason, it is challenging to design or construct geotechnical infrastructure within or with expansive soils. Several billions of dollars losses, world-wide, can be attributed to the repairing, redesigning and retrofitting of infrastructure constructed with or within expansive soils, annually. Piles are widely used as foundations in expansive soils extending conventional design procedures based on the principles of saturated soil mechanics. However, the behavior of piles in unsaturated expansive soils is significantly different from conventional non-expansive saturated soils. Three significant changes arise as water infiltrates into expansive soil around the pile. Firstly, soil volume expansion contributes to ground heave in vertical direction. Secondly, volume expansion restriction leads to development of the lateral swelling pressure resulting in an increment in the lateral earth pressure in the horizontal direction. Thirdly, pile-soil interface shear strength properties change due to variations in water content (matric suction) of the surrounding soil. These three changes are closely related to matric suction variations that arise during the water infiltration process. For this reason, a rational methodology is necessary for the pile load transfer mechanism analysis based on the mechanics of unsaturated soils. Studies presented in this thesis are directed towards developing simple methods to predict the load transfer mechanism changes of piles in expansive soils upon infiltration. More emphasis is directed towards the prediction of the pile mechanical behavior which includes the pile head load-displacement relationship, the pile axial force (shaft friction) distribution and the pile base resistance using unsaturated mechanical as a tool. The function of matric suction as an independent stress state variable on the mechanical behavior pile is highlighted. More specifically, following studies were conducted: (i) Previous studies on various factors influencing the load transfer mechanisms of piles in unsaturated expansive soils are summarized and discussed to give a background of current research. More specifically, state-of-the-art reviews are summarized on the application of piles in expansive soils, mobilization of lateral swelling pressure, mobilization of unsaturated pile-soil interface shear strength and methods available for the load transfer analysis of piles in expansive soils. (ii) Employing unsaturated soil mechanics as a tool, theoretical methods are proposed for estimating the lateral earth pressure variations considering the mobilization of lateral swelling pressure. The proposed methods are verified using two large-scale laboratory studies and two field studies from published literatures. (iii) The shear displacement method and load transfer curve methods used traditionally for pile load transfer mechanisms analysis for saturated soils were modified to extend their applications for unsaturated expansive soils. The influence of volume change characteristics and unsaturated soil properties on unsaturated expansive soils are considered in these methods. The validation of the modified shear displacement method and modified load transfer curve method were established using a large-scale model test performed in the geotechnical engineering lab of University of Ottawa and a field case study results from the published literature. (iv) A large-scale model pile infiltration test conducted in a typical expansive soil from Regina in Canada in the geotechnical lab of University of Ottawa is presented and interpreted using the experimental data of volumetric water content suction measurements and shear strength data. The results of the comprehensive experiment studies are also used to validate the proposed modified shear displacement method and modified load transfer curve method achieving reasonable good comparisons. The proposed modified shear displacement method and modified load transfer curve method are simple and require limited number soil properties including the soil water characteristic curve (SWCC), matric suction profile upon wetting and drying and some soil physical properties. Due to these advantages, they can be easily and conveniently applied in engineering practice for prediction of the mechanical behavior of piles in unsaturated expansive soils, which facilitate practicing engineers to produce sound design of pile foundation in unsaturated expansive soils in a simplistic manner.

Water moves in soil in response to potential gradients. The basic equation for this movement is the generalized flow equation: v = - KV0 in which v is volume of water passing through a unit area in unit time, K is the conductivity coefficient, V is the gradient operator (vector), and V 0 is the potential gradient.

The movement of water in soil presents many interesting problems to the research worker. It is also a subject which finds wide and important application in agriculture and several branches of engineering. The object of this work was to examine the usefulness of a new equation of flow of water in unsaturated soil. If valid, this new approach may be able to eliminate some of the gaps in our present knowledge of the subject. All soil lying above the capillary fringe of a water table is in the unsaturated state with respect to water. This means that in any macroscopic volume element of soil three phases are present-- solid, liquid and gas. The volume fraction of each of these phases show wide variation in both space and time in field soils. The variation in both space and time in field soils. The variation in the volume fraction of the liquid or water phase is accompanied by a considerable change in the physical properties of the water. In the strictest sense the unsaturated state covers all intermediate conditions between saturation and an incomplete monomolecular layer of absorbed water. It is important to recognize that the solid phase is also dynamic. It consists of unconsolidated particles with great variation of size and shape. Many solid phase properties show a complex dependence upon the amount of water present. Swelling and shrinking are well known in soils and these changes affect water movement.

Since weed killers were developed in the early part of the decade beginning in 1940, herbicides have been increasing in use until they are now widely used to control weeds . The application of herbicides has thus become a regular agricultural and ecological practice. Some of the herbicides are applied directly to soils and accompanied by a light irrigation to wash them into the soil in order to increase their efficiency . Some of these chemicals accumulate in the soil and should be removed in order to avoid toxic effect on succeeding plants (Klingman, 1961) . The toxic effect of herbicidal residues in soil and water to human subjects , livestock , and wildlife has been repor•ted (Paynter et al., 1960; Carpenter et al., 1961). When these materials are leached out of the soil , they may pollute the water supply. The movement of water and herbicides in soils is thus closely connected to both their herbicidal and toxic effect and is becoming a serious economic problem. It is the purpose of this investigation to study the simultaneous movement of water and herbicides in unsaturated soils by using the thermodynamic theory of irreversible processes. The adsorption of herbicides, the energy of adsorption, and the break-through curve will also be studied.