Graduate Theses & Dissertations

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Temporal variation of dissolved organic matter and diffusive gradient in thin films-labile mercury in the Quesnel river, BC, and the Goose Creek tributary of Churchill river, MB
This study examined dissolved organic matter (DOM) and labile Mercury (from diffusive gradient in thin films (DGT)) in the Quesnel river, British and the Goose creek tributary of the Churchill river, Manitoba. DOM properties were measured with optical measurements of absorption coefficient (a254), spectral slopes (S275-295, SR) and fluorescence indices (HIX, BIX, FI). The DOC proxy measurements (a254) were almost 10 times higher at the Churchill site (Mean a254 116.77 cm-1) compared with the Quesnel river site (Mean a254 12.06 cm-1) during the study periods. While DGT labile Hg concentrations at the Quesnel site (2.17 to 98.97ppt) were almost 10 times more than the levels reported at the Churchill site (0.03 to 9.06 ppt). Fluorescence indices and the rise of labile Hg concentrations in spring indicated mostly terrestrial sources of DOM at both the sites. Spectral slopes and fluorescence indices substantiated that Churchill site had high molecular weight, complex and more humic DOM compared with Quesnel. DOM at both the sites was prone to temporal variation and affected by environmental conditions. Correlation between DGT labile-Hg and DOM parameters suggested that DGT collected Hg-organic complexes along with inorganic labile-Hg complexes. Author Keywords: Churchill, Diffusive gradient in thin films, Dissolved organic matter, Labile Hg, Mercury, Quesnel
Synthesis of Lipid Based Polyols from 1-butene Metathesized Palm Oil for Use in Polyurethane Foam Applications
This thesis explores the use of 1-butene cross metathesized palm oil (PMTAG) as a feedstock for preparation of polyols which can be used to prepare rigid and flexible polyurethane foams. PMTAG is advantageous over its precursor feedstock, palm oil, for synthesizing polyols, especially for the preparation of rigid foams, because of the reduction of dangling chain effects associated with the omega unsaturated fatty acids. 1-butene cross metathesis results in shortening of the unsaturated fatty acid moieties, with approximately half of the unsaturated fatty acids assuming terminal double bonds. It was shown that the associated terminal OH groups introduced through epoxidation and hydroxylation result in rigid foams with a compressive strength approximately 2.5 times higher than that of rigid foams from palm and soybean oil polyols. Up to 1.5 times improvement in the compressive strength value of the rigid foams from the PMTAG polyol was further obtained following dry and/or solvent assisted fractionation of PMTAG in order to reduce the dangling chain effects associated with the saturated components of the PMTAG. Flexible foams with excellent recovery was achieved from the polyols of PMTAG and the high olein fraction of PMTAG indicating that these bio-derived polyurethane foams may be suitable for flexible foam applications. PMTAG polyols with controlled OH values prepared via an optimized green solvent free synthetic strategy provided flexible foams with lower compressive strength and higher recovery; i.e., better flexible foam potential compared to the PMTAG derived foams with non-controlled OH values. Overall, this study has revealed that the dangling chain issues of vegetable oils can be addressed in part using appropriate chemical and physical modification techniques such as cross metathesis and fractionation, respectively. In fact, the rigidity and the compressive strength of the polyurethane foams were in very close agreement with the percentage of terminal hydroxyl and OH value of the polyol. The results obtained from the study can be used to convert PMTAG like materials into industrially valuable materials. Author Keywords: Compressive Strength, Cross Metathesis, Fractionation, Polyols, Polyurethane Foams, Vegetable Oils
Bifacial Stone Tool Variability during the Late Paleoindian Period at Kruger 2 (BiEx-23), Eastern Townships, Québec
This thesis established the variability of Late Paleoindian bifacial stone tool assemblage from the Kruger 2 site. Kruger 2 is a basecamp occupied during the Pleistocene-Holocene transition in the Eastern Townships, Southern Quebec. The goal of this project is to quantify the variability observed in bifacial tools and to explain it. Geometrics Morphometrics and traditional attributed-base lithic analysis are used conjointly for this purpose. Geometrics Morphometrics are a set of methods that are used to distinguish groups based on their shape and to understand the differences between those groups. It is used to test the validity of the morpho-types used to classify bifacial tools found on Kruger 2 (bifaces, drills, Ste-Anne-Varney points, Agate Basin points, and other projectile points). In terms of explanation, the organization of technology postulates (sensu Nelson 1991) lies at the core of the research. The analysis involved defining the factors of biface shape variation and evaluating whether shape variation is caused primarily by raw material, function, tool life histories, or other design constraints. It was determined that all three of these factors contribute to shape differences. The data suggest that the primary factors are raw material availability and tool life histories – two factors intimately intertwined. In other words, it is the organization of technology that seems to be the driving explanatory force that accounts for shape variability. Author Keywords: Eastern Towhships, Geometrics Morphometrics, Late Paleoindian, Organization of technology, Pleistocene-Holocene Transition, Stonetool variability
ARROWS before AGRICULTURE? A FUNCTIONAL STUDY of NATUFIAN and NEOLITHIC GROOVED STONES
Grooved stones first appear in the Southern Levant with the development of the Natufian culture (~15,000 - 12,000 BP). These tools come in a variety of shapes and sizes; however, they share in common the presence of an intentionally manufactured groove. This thesis focuses on a few types of grooved stones, specifically, those which are often considered to be straighteners for arrow-shafts. If this interpretation is correct, then these tools represent the only clear evidence of the bow and arrow prior to the Neolithic (~12,000 - 6,500 BP), which has implications for our understanding of changing hunting strategies in the millennia leading up to the origins of agriculture. Using an experimental and use-wear approach, I analyse a sample of grooved stones from three Natufian and Neolithic sites in Northern Israel, the results of which generally support the arrow-shaft straightener interpretation. Furthermore, by placing grooved stones in their broader technological context, it becomes apparent that they represent progression and diversification of long-range projectile weapons, which likely existed even earlier in time Author Keywords: grooved stones, Natufian, Neolithic, PPNB, use-wear analysis
Sustainable Development
While there is an emerging body of literature on the role and effectiveness of community-based research (CBR) in addressing the needs of local communities, few studies have explored its promise in areas lacking established collaborative models. The purpose of this paper is to examine the potential of CBR to meet the sustainable community development needs of the primarily urban Durham Region in Southern Ontario. Semi-structured interviews with twenty sustainability-focused community members from the academic, municipal, private and non-profit sectors were conducted using Glaser and Strauss' grounded theory to develop a working hypothesis that was analyzed with the aid of the qualitative data software program ATLAS.ti. The results reveal that while the region's academic and community groups have little time to initiate formal community-campus collaborations, the additional manpower and expertise that a well-structured CBR model provides could significantly assist local organizations complete unfinished projects and undertake new initiatives. Author Keywords: Community-based research, Community-campus collaboration, Cooperative education, Durham Region, Experiential education, Sustainable development
Thinking Ahead
The present thesis entails a qualitative investigation of the unique notion to transition media change from the current paper-based system to the potential use of information technology innovation for communication between health care providers and employers during return to work. Stakeholder perspectives on relevant communication phenomena were gathered from workers, employers, and health care providers with experience in return to work. Methods for analysis involved critical realist grounded theory, as well as the use of a prototype innovation, named the Return to Work Expert App, as a platform for participant evaluation and discourse. The study’s findings provided comprehensive and in-depth understanding of return to work communication, beyond its empirical regularities. The generative mechanisms of common communication problems that were discovered included situated reasoning, media as information (“the medium is the message”), epistemological disjuncture, egoism-altruism-collectivism quandary, and perspective taking. A novel theoretical framework based on ecological psychology was also advanced to offer a coherent and systematic understanding of the situated nature of health care providers’ reasoning and information development. Media change via the Return to Work Expert App was argued to be limited in handling and resolving many of the communication problems that can occur. However, the app had perceptible value and benefits to prospective users that suggested a distinct advantage over current paper-based practices. Opportunities for further development and research exist to address relevant challenges, most notable of all being the need to address the app’s burden of proof. For the interested reader, this thesis advances research and knowledge of provider-employer communication to a state that is truly fitting of the importance acknowledged of it in the field of return to work. Author Keywords: critical realism, ecological psychology, media change, return to work, stakeholder communication, technological acceptance
Individual Differences in Human Tolerance for Wildlife and The Role of Nature Relatedness
Human-wildlife interactions are inevitable and lead to decisions about wildlife. The current research investigated what demographic and psychological factors influence decisions in wildlife management. Also, a new measure, the Tolerance for Wildlife Scale, was developed. A student sample (n = 329) and a community sample (n = 213) completed measures on their nature relatedness, environmental concern, and emotions towards wildlife. They completed the Tolerance for Wildlife Scale and rated decisions to use lethal or non-lethal action in nine human-wildlife scenarios. Correlation analyses revealed people who are more tolerant towards wildlife are more connected with nature, concerned for the environment, feel positive emotions towards wildlife, and are more likely to choose non-lethal management actions. ANOVAs revealed that location and occupation have an impact on tolerance for wildlife. By identifying factors that influence tolerance for wildlife, humans can hope to share space with wildlife and foster coexistence. Author Keywords: emotion, environmental concern, nature relatedness, tolerance, wildlife, wolves
Late Epigravettian Resource Exploitation in the Southern Pre-Alpine Region
This study examines the foraging strategies employed by Late Epigravettian occupants at Riparo Tagliente, Italy. The study sample is composed of highly fragmented macrofaunal remains recovered from a single stratigraphic layer (layer 617) located at the cave border in the southern portion of the site. Models derived from foraging theory, chiefly the Central Place Forager Prey Choice Model, are applied to interpret the pattern of faunal exploitation. Red deer (Cervus elaphus) is the most commonly identified species in the sample, followed by roe deer (Capreolus capreolus) and wild boar (Sus scrofa). The faunal analysis suggests that the site occupants focused their foraging efforts in lower–altitude resource patches at short travel distances. The distribution and composition of the sample indicates that bone may have been used as a fuel source in this area. Author Keywords: Archaeozoology, Foraging Theory, Taphonomy, Upper Paleolithic
Childhood diet and feeding practices at Apollonia
This study analyses deciduous dental pathology and stable carbon and nitrogen isotopes to investigate the relationship between dietary composition, feeding practices, and oral health in a subadult skeletal sample from the Greek colonial site of Apollonia Pontica, Bulgaria (5th to 3rd century BC). Stable isotope analysis of 74 bone collagen samples indicates that weaning began between the ages of 6 months and 1 year, and was complete by the age of 4. The stable isotope data are consistent with a diet of primarily terrestrial C3 resources. The deciduous dentitions of 85 individuals aged between 8.5 months and 10.5 years were examined for evidence of a number of pathological conditions. The presence of dental caries, calculus, occlusal tooth wear and an abscess indicate that foods introduced early in life affected the oral health of these individuals. Overall, the deciduous dental data correlate well with the stable isotope data and ancient textual sources regarding infant and childhood dietary composition and feeding practices. Author Keywords: breastfeeding, deciduous dentition, dental pathology, stable carbon and nitrogen isotopes, weaning
Rethinking Subjectivity
The following thesis problematizes different theories of subject formation in relation to morality, accountability, and consciousness raising. Focusing on the conditions subjects emerge in, I argue that socially transformative subjectivities emerge in movement through spaces. The theoretical discussion departs from the premise that morally accountable subjectivities drive social change. The politics of positionality that anchor the subject in a particular social location conceptualize morality as the result of critical consciousness raising. The causal nature of the relationship between the subject’s ability to reflect back on itself and its moral capacity is problematic for it leaves the reflective subject in a position of epistemic and moral authority. Rather, a subject who does not fully know itself nor the conditions of its being has the ability to engage in moral inquiry. Grounding subject formation in epistemic uncertainty construes the subject as inherently accountable to other unknowing subjects. Transformative subjectivities emerge out of epistemic resistance and uncertainty. The particular understanding of morality that underlies the rethinking of my moral subject emanates from its relational constitution. A morality of care prioritizes the responsibilities a subject has to others. In the context of Covid-19, relational subjects act in accordance with a morality of care that leads them to intervene in the lives of others who are threatened by the virus and left unprotected by institutional structures. The desire to interfere is cultivated when subjects emerge in ontological fields generated through epistemic intervention. One way to create such interventions is through counter-hegemonic cultural production such as works of art. Author Keywords:
Class Struggle, The Communist Party, and the Popular Front in Canada, 1935-1939
This thesis is an attempt to provide a critical history of the Communist Party of Canada (CPC) during the Popular Front era, roughly November 1935 to September 1939. This study contains a detailed examination of the various stages of the Popular Front in Canada (the united front, the height of the Popular Front, and the Democratic front), with special attention paid to the CPC’s activities in: the youth movement, the labour movement, the unemployed movement, the peace movement, and the anti-fascist movement. From this I conclude that the implementation of the Popular Front, the transformation of the CPC from a revolutionary party to a bourgeois party, was not a smooth process, but instead was punctuated and resisted by elements within the CPC in what can be considered a process of class struggle internal to the CPC itself. Author Keywords: Canada, communism, Great Depression, labour, Popular Front, socialism
Life in the Woods
The North American conservation movement and modern conservation model was created in part because of the exploitative commercial hunting industry that caused the collapse of species such as the bison and auk in the late 19th and early 20th centuries. These historical actions continue to shape views today and the public perception of hunting can often be negative. This thesis engaged with this question of social acceptability by conducting action research to determine hunters’ motivations and how these might affect the way hunting is perceived. As part of this action research, I conducted nine in-depth interviews, a survey of 177 hunters, and a focus group to determine what the dominant motivations were for the hunters studied. I then suggest how the motivations discovered through the focus group, interviews, and survey can work towards the current and future social, economic, cultural, and environmental sustainability of hunting in Ontario. Author Keywords: Ethics, Hunting, Motivations, Ontario, Social Acceptance, Sustainability

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