Graduate Theses & Dissertations

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Bio-based Polymers from Epoxidized Vegetable Oils Modified by Metathesis
The epoxides of oligomeric self-metathesized soybean oil (MSBO) and cross-metathesized palm oil (PMTAG) and canola oil (CMTAG) containing terminal double bonds were used to produce nonisocyanate polyurethanes (NIPUs) as well as anhydride, amine and thiol-cured epoxies. The synthesized NIPUs displayed metal adhesive properties for CMTAG and MSBO with MSBO being favoured probably due to its plasticizing nature as opposed to CMTAG. The relationship was reversed for the anhydride curing reaction where it was found that CMTAG, due to its lower degree of plasticizing content from the reduced dangling chains, produced higher tensile strengths than MSBO. Both MSBO and CMTAG led to fully cured amine and thiol products that were sticky gels, which prevented physical analyzses of their expected solidified products. PMTAG, due to its low number of reactive groups, was not suitable for the synthesis of these polymers. Author Keywords: Amine-cured epoxy, Anhydride-cured epoxy, Metathesis, Nonisocyanate Polyurethanes, Thiol-cured epoxy
An Evaluation of Wastewater Treatment by Ozonation for Reductions in Micropollutant Toxicity to Fish
Micropollutants are discharged into the aquatic environment with industrial and domestic wastewater and these compounds may cause toxic effects in aquatic organisms. In this study, the toxic effects to fish of micropollutants extracted from ozonated and nonozonated municipal wastewater effluent (MWWE) were measured in order to assess the effectiveness of ozonation in reducing toxicity. Juvenile rainbow trout (Oncorhynchus mykiss) injected with extracts prepared from ozonated MWWE had significantly reduced induction of plasma vitellogenin (VTG), significantly reduced hepatic total glutathione (tGSH) levels and an elevated oxidized-to-total glutathione (GSSG-to-tGSH) ratio. Exposure of Japanese medaka (Oryzias latipes) embryos to extracts prepared from both ozonated and non-ozonated MWWE resulted in elevated developmental toxicity in both treatment groups. These results indicate that wastewater treatment by ozonation reduces the estrogenicity of wastewater, but treatment may induce oxidative stress and embryonic developmental toxicity due to the production of toxic by-products. Author Keywords: Estrogenicity, Micropollutants, Oxidative stress, Ozonation, Toxic by-products, Wastewater
Sacred Space, Ancestors, and Authority
The Middle Formative Period (1000 – 400 B.C.) has increasing become recognized as a critical locus in the development of Lowland Maya socio-political complexity. This period witnessed the founding of numerous ceremonial centers, substantial material cultural innovation, and the advent of mortuary practices indicating developing social differentiation. Recent excavations at the site of Ka’Kabish in Northern Belize have uncovered evidence significantly strengthening this view. Excavations underlying Plaza D-South at Ka’Kabish have revealed a series of bedrock-hewn pits containing offering caches of thousands of shell beads, forty-seven greenstone objects, and extensive ceramic evidence indicating communal ritual and feasting, which is argued by the author to represent a cosmographic diorama of the cave-riddled Underworld. Significantly, this elaborate cosmographic offering event appears to center on the secondary, bundled bedrock-cist burial of an important personage and/or ancestor who is accompanied by a number of finely crafted jade ornaments representing motifs and forms that have previously been interpreted as symbols of authority, rulership, and divine kingship. Comparable contemporary evidence from Northern Belize and beyond has been interpreted through models foregrounding site-founding, place-making, ancestor veneration, and aggrandizer driven social differentiation. By integrating and contrasting these existing models with new evidence from Ka’Kabish, this thesis argues that the mortuary, caching, and architectural practices evidenced at Middle Formative Ka’Kabish represent a glimpse into the incipience of the ideological complex, the socio-cultural processes, and the material manifestations propagating the development of subsequent Maya socio-political complexity, specifically the institution of divine kingship or ch’uhul ahau. Author Keywords: ancestor veneration, ancient Maya, greenstone cache, Ka’Kabish, Belize, Middle Formative, socio-political complexity
Doing it Right
The cyanidation technique is currently a viable technique for gold recovery that can replace the present amalgamation technique in Guyana. To implement this technique effectively, laboratory scale experiments and at scale runs were conducted to determine the best particle size of the ore, cyanide concentration, and leaching time. In addition, the profitability of cyanidation was compared to the amalgamation technique so as to describe the economic value of cyanidation. Results indicated that up to 94% of gold can be recovered from the ore using an ore particle size of 150 (105 µm), meshes, a cyanide concentration of 0.05% and leaching for 24 h. An economic comparison of this technique with the amalgamation technique indicated that although initial costs are high for the cyanidation technique, profits as high as 83% can be achieved after initializing this method whereas profits would be capped at approximately 25% for the amalgamation technique. Keywords: gold recovery, cyanidation, mercury amalgamation, activated car Author Keywords: activated carbon, cyanidation, gold recovery, mercury amalgamation
Imagining a National Research Centre
The Truth and Reconciliation Commission of Canada (TRC) convened in 2008 and focused on the impact of the residential school on Indigenous people in Canada. It was intended to initiate healing in Indigenous communities while contributing to new understandings between Indigenous and non-Indigenous Canadians. In 2015, the TRC's mandate must be completed, and its final task is creating a National Research Centre (NRC) at the University of Manitoba that will hold all of the documentation generated and collected throughout the TRC's tenure. In this thesis I examine many of the challenges the NRC faces, such as lack of funding, institutional oversight, and the enormity of balancing the needs of Indigenous survivors and their communities against building an accessible archive. At a broader level, questions remain about how successful the TRC has been in achieving reconciliation between Indigenous and non-Indigenous Canadians, and how the NRC can work to fulfill this goal. Author Keywords: archives, Canada, Indigenous, museums, residential schools, truth and reconciliation
Spirituality, Community and Compassion Matter! Exploring Motivators to Providing Holistic Social and Health Services in Peterborough, Ontario
My research explores potential motivators for social and health service providers to be more holistic and compassionate with those they serve. From previous research focused on spirituality, I identified seven additional concepts: faith, religion, community, culture, compassion, wellness, and wholeness. Using elements of Appreciative Inquiry, data was collected through a focus group and an in-depth, online survey. The participants work with Indigenous, religious, other spiritually motivated, or non-spiritual social or health service organizations in Peterborough, Ontario, Canada. Prototype concept analysis allowed participants to personally define each concept, and then indicate how much each motivated them. Results indicate, regardless of individual demographics, the definitions and motivations are very personal. The concepts with the most to least motivational impact were community, compassion, spirituality, wellness, wholeness, culture, faith and religion. Participants' voices speak directly through this research. I use their suggestions to make recommendations for improving the systems within which they provide service. Author Keywords: community, compassion, health services, indigenous knowledge, social services, spirituality
Dissent Denied
In June 2010, the Group of Twenty (G20) met in Toronto, Ontario. The summit drew large-scale protests that culminated in mass arrests and extensive civil rights violations. Given these outcomes, this thesis examines the security spectacle of the summit to assess the evolving state of public order policing and social movement protest in Canadian law and politics. Connecting the securitization of the summit to the politics of neoliberalism, I argue these overlapping forces helped foment the criminalization of political dissent during the 2010 Toronto G20. Author Keywords: mega-events, neoliberalism, public order policing, securitization, security, social movements
Regional Assessment of Soil Calcium Weathering Rates and the Factors that Influence Lake Calcium in the Muskoka River Catchment, Central Ontario
(MRC) in central Ontario was carried out to determine the range and spatial distribution of soil Ca weathering rates, and investigate the relationships between lake Ca and soil and catchment attributes. The MRC is acid-sensitive, and has a long history of impacts from industrial emission sources in Ontario and the United States. Small headwater catchments were sampled for soil and landscape attributes (e.g. elevation, slope, catchment area) at 84 sites. Soil Ca weathering rates, estimated with the PROFILE model, were low throughout the region (average: 188 eq/(ha·yr)) compared to global averages, and lower than Ca deposition (average: 292 eq/(ha·yr)). Multiple linear regression models of lake Ca (n= 306) were dominated by landscape variables such as elevation, which suggests that on a regional scale, landscape variables are better predictors of lake Ca than catchment soil variables. Author Keywords: Calcium, Lakes, Regional assessment, Regression, Soils, Weathering
Soil mineralizable nitrogen as an indicator of soil nitrogen supply for grain corn in southwestern Ontario
Soil mineralizable nitrogen (N) is the main component of soil N supply in humid temperate regions and should be considered in N fertilizer recommendations. The objectives of this study were to determine the potentially mineralizable N parameters, and improve N fertilizer recommendations by evaluating a suite of soil N tests in southwestern Ontario. The study was conducted over the 2013 and 2014 growing seasons using 19 field sites across southwestern Ontario. The average potentially mineralizable N (N0) and readily mineralizable N (Pool I) were 147 mg kg-1 and 42 mg kg-1, respectively. Pool I was the only soil N test that successfully predicted RY in 2013. The PPNT and water soluble N (WSN) concentration (0-30cm depth) at planting were the best predictors of fertilizer N requirement when combing data from 2013 and 2014. When soils were categorized based on soil texture, the relationships also improved. Our findings suggest that N fertilizer recommendations for grain corn can be improved, however, further field validations are required. Author Keywords: corn, nitrogen, nitrogen mineralization, soil nitrogen supply, soil N test, southwestern Ontario
Factors affecting road mortality of reptiles and amphibians on the Bruce Peninsula
Road mortality is one of the leading causes of global population declines in reptiles and amphibians. Stemming losses from reptile and amphibian road mortality is a conservation priority and mitigation is a key recovery measure. I developed a model of road mortalities relative to non-­‐mortalities, based on predictors varying across space (road surface type, traffic volume, speed limit, distance to wetland) and time (weather conditions, traffic volume). Herpetofauna road mortalities were recorded during daily bicycle and vehicle surveys to investigate the impact of roads on reptiles and amphibians within the Bruce Peninsula, Ontario in 2012 and 2013. A total of 2541 observations of herpetofauna on roads were recorded, 79% of which were dead. The major factor influencing turtle road mortality was proximity to the nearest wetland and dates early in the season (spring). For the Massasauga, high daily temperatures and low daily precipitation were associated with road mortality. The major factors driving colubrid snake mortality were also high daily temperature, low daily precipitation, as well as low speeds and paved roads. Frog and toad mortality was driven by proximity to wetland and late summer dates. These models will increase our understanding of factors affecting road losses of herpetofauna and serve as a basis for planned, experimental mitigation within the Bruce Peninsula. Author Keywords: amphibians, hotspot, mitigation, reptiles, road ecology, road mortality
methodological framework for the assessment and monitoring of forest degradation under the REDD+ programme based on remote sensing techniques and field data
In this thesis, a methodological framework for the assessment and monitoring of forest degradation based on remote sensing techniques and field data, as part of the REDD+ programme, is presented. The framework intends to support the implementation of a national Monitoring, Verification and Report (MRV) system in developing countries. The framework proposed an operational definition of forest degradation and a set of indicators, namely Canopy Cover (CC), Aboveground Biomass (AGB) and Net Primary Productivity (NPP), derived from remote sensing data. The applicability of the framework is tested in a sub-deciduous tropical forest in the Southeast of Mexico. The results from the application of the methodological framework showed that the higher rates of forest degradation, 1596-2865 ha·year-1, occur in areas with high population density. Estimations of aboveground biomass in these degraded areas span from 1 to 24 Mg·ha-1, with a rate of carbon fixation ranging from 130 to 246 gC·m2·year. The results also showed that 43 % of the forests of the study area remain with no evident signs of degradation, as detected by the indicators selected, during the period evaluated. The integration of the different elements conforming the methodological framework for the assessment and monitoring of forest degradation enabled the identification of areas that maintain a stable condition and areas that change over the period evaluated. The methodology outlined in this thesis also allows for the identification of the temporal and spatial distributions of forest degradation based on the indicators selected, and it is expected to serve as the basis for operations of the REDD+ programme with the appropriate adaptations to the area in turn. Author Keywords: Forest degradation, Monitoring, REDD+, Remote Sensing, Tropical forest
Hormonal Algae
Based on an endogenous hormone study, three cytokinin type phytohormones; benzyladenine (BA), trans-zeatin (tZ) and methylthiol trans-zeatin (MeSZ), as well as abscisic acid (ABA) were exogenously added at three concentrations (10-7, 10-6 and 10-5 M) to cultures of Chlorella vulgaris in an attempt to alter growth rate, total lipid and fatty acid yields and fatty acid profile. Growth stimulation was highest at 10-6 M for BA, MeSZ and ABA and 10-5 M for tZ. All treatments caused changes in total lipid and fatty acid content, with BA causing an increase to lipid content. The most significant change in the fatty acid profile was observed with the addition of MeSZ at 10-7 and 10-6 M causing increases of 204% and 457% in linolenic acid respectively above the control. These results are novel and potentially highly impactful, as MeSZ has never been added exogenously to algae and may be used to stimulate overproduction of linolenic acid for pharmaceutical or industrial purposes. Author Keywords: Abscisic Acid, Chlorella vulgaris, Cytokinin, Fatty acid, Linolenic Acid, Methylthiol trans-Zeatin

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Graduate student theses produced at Trent University. You may also browse theses and dissertations by year, program, or author.

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