Graduate Theses & Dissertations

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wind tunnel based investigation of three-dimensional grain scale saltation and boundary-layer stress partitioning using Particle Tracking Velocimetry
Aeolian transport of sand particles is an important geomorphic process that occurs over a significant portion of the earth’s land surface. Wind tunnel simulations have been used for more than 75 years to advance the understanding of this process; however, there are still several principles that lack validation from direct sampling of the sand particles in flight. Neither the three-dimensional dispersion of, nor the momentum carried by particles in flight have been properly measured. This has resulted in the inability to validate numerical particle dispersion models and the key boundary-layer momentum partitioning model that serves as the framework for understanding the air-sand feedback loop. The primary impediment to these measurements being made is a lack of tools suited for the task. To this end, this PhD aims to improve existing particle tracking technology, thus enabling the collection of particle measurements during wind tunnel experiments that would address the aforementioned knowledge gaps. Through the design and implementation of the Expected Particle Area Searching method, a fully automated particle tracking velocimetry system was developed with the capability to measure within ½ grain diameter of the bed surface under steady state transport conditions. This tool was used to collect the first 3-D data set of particle trajectories, from which it was determined that a mere 1/8th of sand transport is stream aligned and 95% is contained within ± 45o of the mean wind direction. Particles travelling at increasing spanwise angles relative to the stream aligned flow were found to exhibit different impact and ejection velocities and angles. The decrease in the number of particles with increasing height in the saltation cloud, very close to the bed is observed to transition from a power to a linear relation, in contrast to previous literature that observed an exponential decay with coarser vertical resolution. The first direct measurements of particle-borne stress were captured over a range of wind velocities and were compared with earlier fluid stress measurements taken using Laser Doppler Anemometry. In support of established saltation theory, impacting particle momentum is found to contribute strongly to particle entrainment under equilibrium conditions. In opposition to established theory, however, particle-borne stress was found to reach a maximum above the surface and does not match the change in air-borne stress with increasing distance from the surface. Near surface splashed particles, measured herein for the first time, appear to play a greater role in stress partitioning than previously thought. This study suggests that research is needed to investigate the role of bed load transport on stress partitioning, to differentiate between airborne trajectory types, and to develop particle tracking tools for field conditions. Author Keywords: Aeolian Transport, Eolian Transport, Particle Tracking Velocimetry, Saltation, Stress Partitioning, Wind Tunnel Simulation
Ê-NITONAHK MIYO-PIMÂTISIWIN (SEEKING THE GOOD LIFE) THROUGH INDIGENOUS DANCE
This thesis is about the ways in which Indigenous dance serves as a social determinant of Indigenous health and well-being. Utilizing both contemporary and traditional versions of the Medicine Wheel for the framework, analysis and organization of the thesis allows for a holistic perspective which includes the spiritual, physical, emotional and mental aspects. The importance of Indigenous dance for Indigenous health and well-being is confirmed through: existing literature; interviews with Indigenous choreographers, dancers, theatre artists, and performers; Indigenous exponents of the forms; and Indigenous Elders. In order to contextualize current practices of Indigenous dance, the history of Indigenous dance in relation to colonization is presented. The research and experiences of co-researchers show the need for Indigenous dance and culture to be supported as a social determinant of health and well-being. Author Keywords:
“A City is Not a Place of Origins”
This thesis explores the work of Black queer authors who write and reproduce cities in their texts. James Baldwin and Dionne Brand create knowable and readable spaces of the cities in which they write. By studying the work of these two authors, this thesis seeks to understand how Black queer people navigate city spaces, and how Black queer authors create a literary imaginary about the cities in which their novels are set. Thus, the cities of New York and Toronto become knowable sites through the novels of Dionne Brand and James Baldwin. Using Black queer theory, Black diaspora theory, and Black literary theory, this thesis engages with the novels, essays, and interviews of James Baldwin and Dionne Brand to determine that urban spaces are both liberatory and traumatic for Black queer people. Author Keywords: Baldwin, Black Queer Studies, Black Women, Brand, Diaspora Studies, Lesbian
“Has anybody got my back?”
Drawing on pedagogies of care, queer pedagogy and Foucault’s concept of biopower, this critical narrative study of six women teachers at an Ontario school uses interview data to explore how teaching affects women’s bodies. Findings include the dominance of men in schools; the high rate of violence against teachers committed by students; participants’ unwillingness to show bodily discomfort to students; and the profound effect of motherhood on teaching practice. I call on educators and school administrators to embed care of students’ and teachers’ bodies into the practices of schooling. I also propose that instead of erasing teacher corporeality from classrooms, we allow students to care for teachers’ bodies as part of a healthy, reciprocal caring relationship, developing students’ and sustaining teachers’ capacity to care. Given the underrepresentation of women’s voices speaking about violence against teachers, this thesis is also a repository for women’s narrated stories of assault in Ontario schools. Author Keywords: biopedagogies, body, care, narrative inquiry, pedagogy, teacher
“Just Say Yes” - Sexual Consent and Boundary Setting On-and Offlinle
The present study examined the understanding and behaviours relating to sexual consent on, and offline among men who have sex with men (MSM) and heterosexual men internationally using a convergent parallel mixed-methods approach. Men of both sexual orientation groups presented challenges with negotiating sexual consent, and this was especially true if they scored higher on aggressive traits or had previously experienced childhood abuse or an unwanted penetrative sexual act in adulthood. However, from the results as a whole, MSM reported struggle more with regards to consent negotiation for a variety of reasons (e.g. sexual scripts, power dynamics, additional sexual settings, sex-role positioning). Limitations and future directions are discussed. Author Keywords: heterosexual men, men who have sex with men, sexual assault, sexual consent, technology

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Format: 2023/12/02