Graduate Theses & Dissertations

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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
Women as Gifts and the Triple Hecate Myth in Shakespeare’s Troilus and Cressida, Antony and Cleopatra, and Cymbeline
ABSTRACT Women as Gifts and the Triple Hecate Myth in Shakespeare’s Troilus and Cressida, Antony and Cleopatra, and Cymbeline Women are placed into sexual roles by the patriarchal system in which we live. Gayle Rubin terms this a “sex/gender system” and explains that within this system women are exchanged as “gifts” between men to form kinship ties. The sexual roles this system creates are embodied in the “Triple Hecate myth.” Hecate was the goddess of witchcraft in Ancient Greece and was known to have three faces: Maiden, Nymph and Crone. The Maiden is in girlhood and the label is applied to any woman before she becomes sexually active. The Nymph is a sexually active woman who lives within the norms of society. A sexually active woman who lives outside those norms is a Whore. A Crone is a woman who has passed menopause. She is seen as either a wise elder or a wicked stepmother figure. In Shakespeare’s plays Troilus and Cressida, Antony and Cleopatra, and Cymbeline, the female protagonists Cleopatra, Imogen and Cressida are all trying to control their own destinies and rise above or manipulate this patriarchal system of control. These three women are travelling through the “Triple Hecate Myth.” Cleopatra begins a Whore and ends a Nymph, Imogen begins a Maiden and ends a Nymph, and Cressida begins a Maiden and ends a Whore. They each also problematize the “gift” exchange system either by attempting to self-exchange (Cleopatra and Imogen) or by being exchanged multiple times (Cressida). Keywords: William Shakespeare, Triple Hecate Myth, Gift Exchange, Gayle Rubin, Cymbeline, Troilus and Cressida, Antony and Cleopatra, Feminist Criticism, Classical Studies Author Keywords: Antony and Cleopatra, Cymbeline, Gayle Rubin, Shakespeare, Triple Hecate, Troilus and Cressida
Novel Aliphatic Lipid-Based Diesters for use in Lubricant Formulations
Structure-property relationships are increasingly valued for the identification of specifically engineered materials with properties optimized for targeted application(s). In this work, linear and branched diesters for use in lubricant formulations are prepared from lipid-based oleochemicals and their structure-property relationships reported. It is shown that the branched diesters possess exceptional physical property profiles, including suppression of crystallization, and are superior alternatives for use in lubricant formulations. For the linear aliphatic diesters, both high and low temperature properties were predictable functions of total chain length, and both were differently influenced by the fatty acid versus diol chain length. Symmetry did not influence either, although thermal stability decreased and thermal transition temperatures increased with increasing saturation. All of the linear diesters demonstrated Newtonian flow behaviour. Viscosity was also predictable as a function of total chain length; any microstructural features due to structural effects were superseded by mass effects. Author Keywords: Crystallization, Phase behaviour, Rheology, Structure-Function, Thermogravimetric analysis, Vegetable Oils
Art of the Sustainable Street
ABSTRACT The Art of the Sustainable Street Miriam L. R. Mutton The street influences our sense of community every day. It is argued that getting the street right communicates a collective vision for action leading to sustainable community. This investigation continues conversations for community repair and resilient change, especially for small town Ontario. The researcher is informed by ways of seeing inspired by Walter Benjamin’s literary montage, The Arcades Project. By method of collecting and connecting information from literature sources spanning several decades and recent interviews, this thesis demonstrates in narrative form the value to community of everyday street details of human scale. Recurrent themes are adopted as technique in validation. Findings are presented from various perspectives including those of the design professional and the politician. The sustainable street enables communication. Research outcomes indicate knowledge transferred through the art of storytelling supports place-making and connection to community. Fragments of information connect into themes defining safe streets which foster trust among strangers, and facilitate citizenship and good governance. Key words: sustainable community, citizenship, safe streets, Benjamin, governance Author Keywords: Benjamin, citizenship, governance, safe streets, sustainable community
Mitigating Cold Flow Problems of Biodiesel
The present thesis explores the cold flow properties of biodiesel and the effect of vegetable oil derived compounds on the crystallization path as well as the mechanisms at play at different stages and length scales. Model systems including triacylglycerol (TAG) oils and their derivatives, and a polymer were tested with biodiesel. The goal was to acquire the fundamental knowledge that would help design cold flow improver (CFI) additives that would address effectively and simultaneously the flow problems of biodiesel, particularly the cloud point (CP) and pour point (PP). The compounds were revealed to be fundamentally vegetable oil crystallization modifiers (VOCM) and the polymer was confirmed to be a pour point depressant (PPD). The results obtained with the VOCMs indicate that two cis-unsaturated moieties combined with a trans-/saturated fatty acid is a critical structural architecture for depressing the crystallization onset by a mechanism wherein while the straight chain promotes a first packing with the linear saturated FAMEs, the kinked moieties prevent further crystallization. The study of model binary systems made of a VOCM and a saturated FAME with DSC, XRD and PLM provided a complete phase diagram including the thermal transformation lines, crystal structure and microstructure that impact the phase composition along the different crystallization stages, and elicited the competing effects of molecular mass, chain length mismatch and isomerism. The liquid-solid boundary is discussed in light of a simple thermodynamic model based on the Hildebrand equation and pair interactions. In order to test for synergies, the PP and CP of a biodiesel (Soy1500) supplemented with several VOCM and PLMA binary cocktails were measured using a specially designed method inspired by ASTM standards. The results were impressive, the combination of additives depressed CP and PP better than any single additive. The PLM and DSC results suggest that the cocktail additives are most effective when the right molecular structure and optimal concentration are provided. The cocktail mixture achieves then tiny crystals that are prevented from aggregating for an extended temperature range. The results of the study can be directly used for the design of functional and economical CFI from vegetable oils and their derivatives. Author Keywords: Biodiesel, Microstructure, Polymorphism, Pour point depressants, Triacylglycerol, Vegetable Oil Based Crystal Modifier
Smote and Performance Measures for Machine Learning Applied to Real-Time Bidding
In the context of Real-Time Bidding (RTB) the machine learning problems of imbalanced classes and model selection are investigated. Synthetic Minority Oversampling Technique (SMOTE) is commonly used to combat imbalanced classes but a shortcoming is identified. Use of a distance threshold is identified as a solution and testing in a live RTB environment shows significant improvement. For model selection, the statistical measure Critical Success Index (CSI) is modified to add emphasis on recall. This new measure (CSI-R) is empirically compared with other measures such as accuracy, lift, efficiency, true skill score, Heidke's skill score and Gilbert's skill score. In all cases CSI-R is shown to provide better application to the RTB industry. Author Keywords: imbalanced classes, machine learning, online advertising, performance measures, real-time bidding, SMOTE
Water Management Amongst the Ancient States of Cambodia, Myanmar, Thailand, Java, and Belize
This thesis investigates the organization and development of water management systems in a sample of past tropical societies in Southeast Asia and Mesoamerica. A comparative approach is employed to show how water management affected the trajectories of the ancient states of Angkor, Cambodia, Bagan, Myanmar, Sukhothai, Thailand, Central and East Java, and Caracol, Belize. Differing types of water management is demonstrated through the use of the adaptive cycle, a conceptual framework through which a broad range of socio-ecological data can be examined in order to explore shifting levels of resilience over time. To understand why levels of resilience might change over time, entanglement theory, which looks at the relationships between humans and things, is utilized to determine how entangled these societies were with water management. Particular degrees of entanglement and shifting levels of resilience provide the analysis with the means to explore how water management changed over time as these societies rose, grew, and finally collapsed. Author Keywords: Ancient Tropical Societies, Entanglement, Resilience, Socio-Ecological Dynamics, Southeast Asia, Water Management
Tłı̨chǫ, Co-management and the Bathurst Caribou Herd, 2009-2011
Since time immemorial caribou have been and remain central to Tłı̨chǫ life and culture. As early as the late 19th century, Canada began to implement wildlife management policies in the NWT in response to concern over the health and future of caribou populations. However, the 2005 Tłı̨chǫ Land Claims and Self-Government Agreement (Tłı̨chǫ Agreement) signed by the Tłı̨chǫ, the Government of the Northwest Territories and the Canadian Government outlines that Tłı̨chǫ will have a say in wildlife management on Tłı̨chǫ Lands. Co-management is the power-sharing model used in an effort to ensure that the Tłı̨chǫ voice is heard in these decisions. My thesis centres on the 2009-2011 co-management process and the resulting final management decisions regarding monitoring and management actions to promote the stabilization and recovery of the Bathurst Caribou herd. I focus my analysis on the Tłı̨chǫ perspective as expressed during this co-management process. I conclude that while Tłı̨chǫ perspectives were presented in the hearings and related processes, they were not well represented in the final management actions. This omission speaks to the wider issue of how aboriginal people are treated and understood in Canada. Author Keywords: Canada, Caribou, Co-management, Northwest Territories, Tłı̨chǫ
Energy Resilience in Northern Communities
This project examines the factors for success of alternative energy initiatives in remote northern Indigenous communities, and the link between northern community energy and resilience. The case study, in the Gwich’in village of Fort McPherson, Northwest Territories, focuses upon a biomass boiler district heating project that provides renewable heat fuelled by local wood chips, and the willow harvesting initiative that supports it. Data was collected by interviews and participant observation in Fort McPherson and Yellowknife, and by analysis of resilience, community energy, and biomass literature. Success factors identified include the importance of aligning energy systems with local cultural identity, traditional values and connection to landscape, values often under-represented in financially-driven energy decisions. Autonomy and self-reliance are shown to be critical factors in northern community energy decisions, related to well-being, pride in place and enhanced resilience. Community resilience is revealed as a key component of northern community energy success. Author Keywords: Energy, Indigenous, Northern, Renewable, Resilience, Sustainable
Authenticity, Authority and Control
This three-part history explores Web 2.0’s ability to make music products a collaborative, ongoing creative process that is reflective of early twentieth century live-music publics, where the realization of a performance was actualized by performers together with their audience in a shared physical space. By extension, I follow the changing dynamic of the producer/consumer relationship as they transitioned through different media and formats that altered their respective roles in music making. This study considers the role that rock ideology, specifically that of the ‘indie-rock’ habitus, plays in shaping both a rock artist’s desired image and a fan-base’s expectations. How rock musicians use the internet reveals their own views on authenticity in recorded music and the extent to which they are willing to participate in a public with their audience. Primary case studies used are: Neil Young, Dave Bidini, Beck Hansen and Joel Plaskett. Keywords: popular music; indie-rock; Web 2.0; rock music collaboration; fan participation; publics; authenticity; habitus; Neil Young; Dave Bidini; Beck Hansen; Joel Plaskett; Song Reader; Scrappy Happiness; Canadian music Author Keywords: authenticity, fan participation, indie-rock habitus, popular music, rock music collaboration, Web 2.0
Stable Isotope Analysis of Archaeological Faunal Remains From the Middle Trent Valley, Ontario
A sample of faunal remains (n=129) from seven archaeological sites located on Pigeon and Rice Lakes, Ontario were sampled and analyzed for the stable carbon and nitrogen isotopic composition of bone collagen. These samples date from the Archaic to Late Woodland and include 35 different animal species. The goal of this research was to investigate the isotope ecology of the Middle Trent Valley and characterize the degree to which isotope ratios varied across space and time between different lakes, as wells as variation within and between species. There were no statistically significant differences in the Middle Trent Valley δ13C or δ15N according to space and time. As such, the isotope data for all archaeological sites were combined to construct an isotope food web for the Middle Trent Valley and compared to Katzenberg’s (1989) food web. These isotope data provide some insight into the dynamic interplay between local ecosystems, and anthropogenically modified landscapes in Ontario. Author Keywords: carbon, food web reconstruction, human-animal relations, Middle Trent Valley, nitrogen, Stable isotope ecology
Mixed methods approaches in marine mammal science
This thesis explored the contribution of mixed methods approaches to marine mammal science through the use of concurrent and sequential designs to study distribution and feeding ecology of bowhead whales (Balaena mysticetus) in the Arctic region of Nunavik, Quebec, Canada. The study combines Inuit knowledge (IK), collected through semi-directed interviews with Inuit harvesters, and analyses of stable isotopes and trace elements (SI/TE) in baleen plates. A systematic literature review found that mixed methods are increasingly used in marine mammal ecology studies in remote locations, yet are still relatively rare and face a number of challenges. Both IK and SI/TE, indicated that bowhead whales have a seasonal pattern in their distribution and feeding ecology. They are most commonly present in productive nearshore areas in summertime, feeding in areas of great prey diversity, and moving to offshore areas in winter to fast. Mixed methods approaches used in this case study enabled the collection of complementary knowledge about bowhead whale ecology important for local management in a changing climate. This study also shows the value of mixed methods approaches for future marine mammal studies in Nunavik and elsewhere. Author Keywords: Arctic, bowhead whale, distribution, feeding ecology, mixed methods, traditional ecological knowledge

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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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