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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Study on Adsorption of Inorganic-organic Hybrid Polymers and Flocculation of Oil Sands Tailings

Wang, Shiqing Unknown Date
No description available.
142

Adsorption and Desorption Behaviour of Organic Molecules on Kaolinite Particles in Non-aqueous Media

Fafard, Jonathan 13 September 2012 (has links)
Organoclays modelling the Athabasca oil sands were prepared in heptane and toluene showing indole loading occurring exclusively on the external surface of the clay, via a multilayer adsorption mechanism. Solvent adsorption was minimal. Vermicular microstructures, similar to natural kaolinite were formed. Isotherms were constructed and fitted to the BET equation, giving monolayer quantities (9.28mg) that matched well to the theoretical amount calculated from surface area measurements (8.87mg). Dispersing the organoclays in isopropanol and in toluene left a monolayer equivalent. Using cellulose as a competitive desorption agent in asphaltene based organoclay dispersions achieved complete disaggregation of the dispersed organoclay stacks.13 C CP - MAS NMR, showed up to a 25% increase in desorption for aliphatic and up to 40% increase in desorption for aromatic functionalities of the loaded organic matter. Investigation of other saccharides and modified celluloses as competitive agents is recommended for future work.
143

Producing Barrels from Bitumen: A Political Ecology of Price in Explaining the Classification of the Alberta Oil Sands as a Proven Oil Reserve

Hemmingsen, Emma 17 February 2010 (has links)
In December, 2002, the oil sands of Alberta, Canada – earlier seen as an obscure, obstacle-ridden scientific project – were for the first time included in the Oil & Gas Journal’s year-end review of worldwide oil reserves. To explain this decision, the editors of this prestigious international petroleum magazine cited the basic neoclassical economic theory of price-driven resource substitution. This thesis contends, however, that the neoclassical theory in fact explains very little of how it became possible to profitably extract petroleum from Alberta’s bitumen-saturated sands. Merging insights from resources geography on the politics of nature-based production with scholarship on calculation and classification in Science and Technology Studies, this thesis fleshes in much-needed detail and dimension to the neoclassical account by emphasizing the role of key actors and decision-makers, many within the state but also within the private sector, who have actively negotiated supply costs and pursued technological strategies for the oil sands. In doing so, it argues that market prices and supply costs are not independent objects, but are underpinned by a malleable, contingent, and profoundly political process. As evidence, this thesis draws on national and international petroleum statistics, industry publications and public relations campaigns, as well as over 80 years of archived and more contemporary government documents, in order to show that substitution between two materially different resources is rarely an independently propelled or inevitable response.
144

Identification of Oil Sands Naphthenic Acid Structures and Their Associated Toxicity to Pimephales promelas and Oryzias latipes

Bauer, Anthony E January 2013 (has links)
The oil sands, located in north-eastern Alberta, are one of the largest deposits of oil worldwide. Because the Alberta Environmental Protection and Enhancement Act prohibits the release of oil sands process-affected material into the environment, industry is storing vast quantities of tailings on mine lease sites. The oil sands industry is currently accumulating tailings waste at a rate of >105 m3/day, for which reclamation strategies are being investigated. Naphthenic acids (NAs) have been identified as the most toxic component of oil sands tailings as they are considered acutely toxic to a variety of biota, and are therefore a target contaminant for tailings pond reclamation strategies. Current literature based on Microtox® assays (marine bacteria Vibrio fischeri) suggests that lower molecular weight NAs are more toxic than higher molecular weight NAs. The following thesis involves the utilization of NA fractions and their relative toxicities to determine if NA toxicity is related to NA molecular weight. A previous study generated an oil sands-derived naphthenic acid extract (NAE), which was fractionated by distillation at stepped temperatures, yielding five fractions with increasing median molecular weights (Daltons). In the present study, the same extract and five fractions were utilized. To expand on the earlier characterization which involved a low resolution electrospray ionization mass spectrometry (ESI-MS), the whole extract and five fractions were analysed using electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS). Mean molecular weights were generated for each fraction, and an increase in molecular weight with increasing fraction number was confirmed. Respective mean Daltons and relative proportions for each fraction are as follows: 237 and 11.9 % (fraction 1), 240 and 32.3% (fraction 2), 257 and 33.4% (fraction 3), 308 and 16.8% (fraction 4), and 355 and 5.6% (fraction 5). When chemical analyses of fractions were compared, it was determined that structures contributing to increased molecular weight included increased cyclic structures (up to 7-ring structures), aromaticity (mono- and diaromatics), nitrogen, sulfur, and oxygen heteroatoms, and dihydroxy/dicarboxy compounds. In addition, characterization data suggested the presence of NAs exhibiting estrogenic structures. Following chemical characterization, NA fractions were subject to embryo/larval bioassays using two fish species: Oryzias latipes (Japanese medaka) and Pimephales promelas (fathead minnow). Endpoints evaluated were mortality, time to hatch, hatch length, and abnormalities. Results suggest that relative NA fraction toxicity is not related to molecular weight, as no trend relating mean Dalton weight to toxicity was observed for any endpoint in both species. Acute toxicity data indicated differences between fractions as high as 2-fold, although results were species-dependent. Fraction 1 displayed the lowest potency (highest LC50) for both Japanese medaka (0.291 mM) and fathead minnow (0.159 mM). Fractions 3 and 2 for Japanese medaka (0.149 and 0.157 mM, respectively), and fractions 5 and 2 for fathead minnow (0.061 and 0.080 mM, respectively) displayed the greatest potencies for mortality (lowest LC50). When fraction LC50s for Japanese medaka were compared to the whole NAE (0.143 mM), the mid molecular weight fractions (fractions 2 and 3) appeared most similar to the whole NA. . In terms of relative toxicity and proportion, constituents in the mid molecular range fractions (2 and 3) likely represent greater risk compared to other fractions, and further chemical and toxicological characterization of constituents within these fractions is warranted particularly for long-chained, monocarboxylic acids, with low aromaticity. Japanese medaka and fathead minnow varied in their sensitivity and their relative response to different fractions. In general, fathead minnow were more sensitive than Japanese medaka based on lower estimates of LC50 and threshold (growth) values in addition to the presence of developmental abnormalities (predominately yolk sac edema) associated with a few of the fractions. Compared to differences in toxicity between fractions for a given species (>2-fold for fathead minnow), there was more variability between species for a given fraction (> 3-fold for fraction 5). Also, the relative toxicity of fractions as indicated in the present study is contrary to the results generated using Vibrio fischeri for the same fractions. Thus, there is a need for multi- endpoint and species toxicity evaluations to assess the efficacy of remediation and reclamation options for reducing toxicity of oil sands tailings.
145

Reclamation of wetland habitat in the Alberta oil sands: generating assessment targets using boreal marsh vegetation communities

Raab, Dustin Jeremy 11 1900 (has links)
Thousands of hectares of wetlands are being destroyed by oil sands mining in Alberta, and the industry must undertake wetland reclamation to compensate for these losses. Wetland vegetation has developed at some previously mined sites, however reclamation is thus far exploratory, and limited in extent. To inform reclamation practices and assist compliance monitoring I examined vegetation communities in 25 natural boreal wetlands and 20 oil sands reclaimed wetlands, developed a Vegetation-based Index of Biological Integrity (vIBI) to quantify the ecological health of wetlands, and identified possible physical and chemical barriers to reclamation. The vIBI identified 6 reclaimed wetlands in fair to good health, however reclaimed wetlands have different vegetation communities, do not produce the same level of aboveground biomass, and have lower levels of sediment nutrients than natural wetlands. To reclaim healthy wetlands, planning should focus on establishing appropriate species, and alleviate nutrient and sediment deficiencies. / Ecology
146

Degradation of Naphthenic Acids in Athabasca Oil Sands Process-Affected Water Using Ozone

Hongjing , Fu 06 1900 (has links)
In order to determine the degradation of Naphthenic Acids (NAs) in oil sands process-affected water (OSPW), a series of semi-batch ozonation experiments have been conducted resulting in a maximum reduction of NAs greater than 99%. Compared to the high NAs removal, the reduction of both COD and DOC was much lower under the same conditions. Following ozone treatments of approx. 80 mg/L, the cBOD5 and cBOD5/COD tripled as compared to original OSPW measurements, suggesting ozone-treated OSPW has a higher biodegradability. The ozone treatments also detoxified the OSPW; with an ozone treatment of approx. 100 mg/L, the treated OSPW showed no toxicity using the Mircotox® bioassay. Additionally, the coke-treated OSPW, treated using a coke/water slurry process, was found to be non-toxic with an ozone treatment of approx. 20 mg/L. The results obtained during this study shows the great potential ozonation may offer as a possible water treatment application for oil sands water management. / Environmental Engineering
147

Women's gendered experiences of rapid resource development in the Canadian North: new opportunities or old challenges?

O'Shaughnessy, Sara 11 1900 (has links)
Rapid resource development in northern and rural Canada is leading to unprecedented social, political, economic and environmental changes in a number of communities. In particular, gendered identities and divisions of labour in northern Canadian communities are poised to be dramatically altered by increasing labour demands, shifting time-use patterns, and intensifying income inequalities. Through a feminist poststructuralist discourse analysis of print media coverage of gendered issues in Fort McMurray, and semi-structured interviews with thirty-two women working in either the male-dominated oil sector or the female-dominated social services sector, this dissertation examines how women in Fort McMurray, Alberta—the host community for the Athabasca oil sands—negotiate their identities and make sense of the opportunities and challenges associated with the recent oil boom. Drawing on materialist feminist and feminist poststructuralist theory, this dissertation first elaborates a comprehensive analytical framework for investigating gender in the context of natural resource extraction. This framework contends that gendered identities are inherently multiple, and divisions of labour are embedded in particular temporal and spatial contexts. Furthermore, this framework examines discursive and material contradictions in diverse gendered experiences of resource extraction in order to move beyond universalizing gendered interests and identities. Second, this dissertation examines how discursively constructed female subject positions in local and global print media over the past decade adopt a frame of frontier masculinity. I demonstrate that these subject positions become resources upon which women in Fort McMurray draw on to negotiate their identities in ways that perpetuate a sense of dependency and anomalousness. Finally, I explore how neoliberal discourses of individualism and meritocracy provide a potential site of resistance to hegemonic frontier masculinity in women’s narratives of their opportunities and challenges. However, I ultimately argue that neoliberal discourses and practices do not prove transformative of gendered identities and divisions of labour because women are only able to partially engage with neoliberal subjectivity, which neglects collective interests and wellbeing.
148

Molecular simulation of the wetting of selected solvents on sand and clay surfaces

Ni, Xiao 06 1900 (has links)
Molecular dynamics simulation and density functional theory were applied to calculate heats of immersion (Himm) of n-heptane, toluene, pyridine and water on two model sand surfaces and two model clay surfaces. Our results indicated that water showed the highest Himm for the model clay surfaces when multi-molecular water layers were used but the lowest when a single molecular layer was used. Simulations of a single molecular water layer sandwiched between a single molecular layer of the aforementioned organic compounds and the octahedral surface of clay indicated that the water layer was not stable. In particular, water molecules tended to desorb from the surface and clustered together to form water/water hydrogen bonds. Given the nature of bitumen molecules, the current results support the hypothesis that a pre-existing water layer on the sand and clay surfaces in raw oil sands is plausible so long as it is thick enough. / Chemical Engineering
149

Natural Recovery of Upland Boreal Forest Vegetation on a Hummocky Peat-Mineral Mix Substrate in the Athabasca Oil Sands Region, Alberta

Shaughnessy, Brenda Erin 06 1900 (has links)
This research investigated the natural recovery of upland boreal forest vegetation on a peat-mineral mix substrate in the Athabasca Oil Sands Region, Alberta. Three sites, aged 26 to 34 years, were assessed to determine effects of substrate (pH, electrical conductivity, texture), topography, slope, aspect, hummock size, litter depth, tall shrub and tree stem densities, canopy cover, and tree ages on community composition and cover of upland boreal vegetation. Environmental variables that had the most influence on the plant communities were substrate texture (clay), tree canopy cover, and tall shrub stem density. The plant communities, which likely developed from early successional lowland communities, most closely approximate an upland boreal mixedwood forest in transition from an early to mid successional stage. Community development was concluded to be a product of measured environmental variables, with unmeasured factors such as propagule dispersal, germination conditions, and initial species composition also playing important roles. / Land Reclamation and Remediation
150

Two partners in Boston the careers and Daguerreian artistry of Albert Southworth and Josiah Hawes /

Moore, Charles LeRoy. January 1975 (has links)
Thesis--University of Michigan. / Includes bibliographical references (vol. 1, leaves 408-421).

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