Theses

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The theses in UWSpace are publicly accessible unless restricted due to publication or patent pending.

This collection includes a subset of theses submitted by graduates of the University of Waterloo as a partial requirement of a degree program at the Master's or PhD level. It includes all electronically submitted theses. (Electronic submission was optional from 1996 through 2006. Electronic submission became the default submission format in October 2006.)

This collection also includes a subset of UW theses that were scanned through the Theses Canada program. (The subset includes UW PhD theses from 1998 - 2002.)

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Exploring the importance of community freezers and a country food box distribution program in the Inuvialuit Settlement Region, Northwest Territories, Canada
(University of Waterloo, 2025-12-23) Yurris, Aimee Caroline
Background: Consuming food harvested from the land, water, and sky (country food) is important for the physical and cultural wellbeing of Inuvialuit. Community freezers are infrastructure intended to support the safe storage of country foods. Further, community freezers have the potential to play a role in food-related programming, such as country food distribution programs. Despite the prevalence of community freezers across Inuit Nunangat, there are few published studies evaluating the implementation and impact of these spaces. Objectives: The specific objectives of this thesis are to describe the use, importance, strengths and barriers, and overall outcomes of the implementation of community freezers in the context of the Inuvialuit Settlement Region, and to describe the importance, strengths, and areas for improvement of the Inuvialuit Community Economic Development Organization country food box distribution program as a program run in connection to community freezers across the region. Methods: Using a qualitative case study design, this project involved semi-structured interviews with community members (n=42) who use the community freezer(s) or could potentially use the community freezer(s) in Paulatuk and Tuktoyaktuk, as well as semi-structured interviews with individuals responsible for managing community freezers (n=7) across Inuvialuit Settlement Region communities. Data were analyzed using reflexive thematic analysis, drawing upon participatory analysis techniques with local community researchers to ensure that results reflect community contexts and realities. Results: The findings describe the importance of freezer space and supplies for storing food (i.e., bins, Ziploc bags, and vacuum sealers) for access to country food, particularly given the number of factors such as cost of gas and equipment that impact community members’ ability to engage in harvesting practices. Despite different community freezer management practices used across the communities of Paulatuk and Tuktoyaktuk, community members in both communities experienced benefits from having and using a community freezer. Such benefits include increased access to freezer space and enjoying increased access to country foods via programs run through the community freezer. Across both communities, community freezers enable the sharing of country foods, enable the storage of larger food items and large quantities of food, and support Inuvialuit culture, way of life, and wellbeing. Challenges with community freezers include lack of communication and awareness about the freezer, reliability of the freezer, ensuring food safety and organization, and the cost and time required for managing and maintaining community freezers. The findings also describe the importance of the Inuvialuit Community Economic Development Organization country food box distribution program. Community members expressed that the country food boxes increase their access to country food and provide support for harvesters who contribute foods to the program. Strengths of the program include the convenience of the foods included in the boxes, variety and the ability to try new foods, and that the program enables the sharing of country food. Suggested areas for improvement include increasing portion size and knowing where and who the harvested foods came from. Conclusion: Reliable and sufficient storage for country foods is an important component of food security in the Inuvialuit Settlement Region. This project has made an important contribution to the literature on the importance of community freezers in the Western Arctic and provides valuable evidence for communities across the Inuvialuit Settlement Region seeking to advocate for additional investment into community freezers. This study also contributes valuable information to the ongoing improvement of the Inuvialuit Community Economic Development Organization country food box distribution program, highlighting both strengths and potential areas for improvement.
Bioptic Telescopic Spectacles and Driving Rehabilitation for People with Age-Related Macular Degeneration: A Pilot Project
(University of Waterloo, 2025-12-23) Khakneshin, Sahar
Introduction Driving is a multifactorial task of which vision is a component. A person’s ability to meet requirements to gain or maintain a driver’s license may be compromised by visual impairments (VI) caused by ocular diseases such as Age-related Macular Degeneration (AMD). However, vision is only one component of safe driving. Programs aimed at permitting and individually assessing a person’s ability to drive are important for improving the quality of life of Canadians living with VI whose ability to safely drive may be in question. Purpose In Ontario in October 2020, the Highway Traffic Act was amended to allow the use of [bioptic] telescopes to meet provincial visual acuity requirements for Class G licensure for the first time. pending successful completion of an on-road driving assessment while using the telescope (MTO Bioptic Telescope Program). The George & Judy Woo Centre for Sight Enhancement (CSE) in Waterloo, Ontario has formulated a training protocol involving both fitting and training with a bioptic telescope for driving. The aim of this study aim was to determine whether the program sufficiently prepares individuals with AMD to effectively use their bioptic telescope, as determined by success in a simulated in-car evaluation. Methods The study aimed to recruit up to 10 participants with AMD who had lost their driver’s license within the last 5 years, met MTO Bioptic Telescope Program visual requirements and did not suffer from motion sickness or cognitive impairment (by self-report). Visual function and visual perceptual testing as well as bioptic telescope fitting were administered. Participants also proceeded into the CSE training program which included 3-5 training sessions and a counselling session. Participants’ driving skills and use of bioptic telescope(s) were then assessed in a virtual reality SUV driving simulator both with and without the telescope. Results Three participants (mean age of 74 years, male) were enrolled and completed the study. Visual parameters met the eligibility criteria (corrected visual acuity ranged from 0.35logMAR (20/50) to 0.77logMAR (20/126), contrast sensitivity ranged from 1.00-1.45logCS units and visual fields were full peripherally). All three participants had binocular central scotomas identified on Humphrey monocular full field tests and Nidek microperimetry. However, no central scotoma was evident on the Humphrey Estermann binocular field assessment. Each participant was fit with a bioptic telescope (2.2-3x magnification) and completed three training sessions. All participants passed the Scan Course but failed the other visual perceptual tests (Useful Field of View, Trail Making, Motor Free Visual Perceptual Test-4). Participant 3 failed the Montreal Cognitive Assessment for the Blind and Visually Impaired. In the final assessment, Participant 1 successfully completed the driving simulation with and without the telescope with no critical driving errors. Participant 2 passed only with the telescope which was used appropriately to identify traffic and speed signs. Participant 3, despite having the best visual acuity, failed under both conditions with critical errors. Conclusion Although further research is required, several important findings to date have been identified. First, the Esterman binocular visual field test cannot be solely used to determine the full field of those with a potential central deficit. Second, the visual perceptual tests conducted with the cut-offs provided, did not definitively identify those individuals that may not be suitable for driving with bioptics; a functional assessment appears to continue to be the gold standard. Third, full medical evaluation should be conducted prior to the visual function evaluation to help identify those that are not safe driving due to non-visual reasons. Finally, it appears that the CSE Bioptic Fitting and Training Protocol may effectively enable participants to learn to apply the fundamental skills required for using a bioptic telescope in a driving situation.
Cues, Clones, and Cars: Access Control Issues in Customized Android
(University of Waterloo, 2025-12-23) Vyas, Parjanya
Android’s open-source design and extensive customization have fueled its dominance across smartphones, automotive systems, wearables, and other domains. This flexibility, however, introduces serious security challenges, particularly in the enforcement of access control. Prior research has investigated inconsistencies within the framework, across layers, and across Android versions, yet important gaps remain, especially in detecting vendor-introduced data-driven customizations, replicated APIs, and platform-specific adaptations (e.g., automotive) that are difficult to capture with existing techniques. This dissertation investigates how Android contextual features can be systematically leveraged to uncover access control vulnerabilities that evade prior analyses. It presents four main contributions: - Bluebird: a probabilistic inference framework that derives access control requirements from application-side sensitivity indicators (UI cues and app-side access control). By fusing NLP-driven signals with static analysis, Bluebird identifies APIs whose protections do not match implied sensitivity. Applied to 14 ROMs, Bluebird flagged 391 likely under-protected private APIs.% and supported 11 proof-of-concept exploits. - Ariadne: a static-analysis based technique built around a novel access control dependency graph abstraction that models explicit and inferred access control relationships among framework data holders. Ariadne detects inconsistencies introduced by data-driven vendor customizations that traditional tools miss. Evaluated on AOSP and vendor ROMs, it discovered 30 unique inconsistencies and enabled 13 proof-of-concept exploits. - RepFinder: a large-scale measurement pipeline that identifies duplicated or ``Replica'' APIs created via copy-paste editing and evaluates their access control enforcement. Analyzing 342 ROMs from 10 vendors, RepFinder found replication to be widespread (~141 Replicas/ROM on average) and that a significant fraction (37% on average) of Replicas are under-protected. - AutoAcRaptor: a platform-specific static analysis framework for AAOS that identifies automotive entry points and evaluates both access control and feature-check enforcement. Applied to 10 AAOS ROMs, AutoAcRaptor reported an average of 23 auto feature and access control anomalies per ROM. Collectively, these contributions show that Android contextual features such as app-side sensitivity indicators, framework data holders, and platform-specific service registrations can be systematically harnessed to reveal overlooked access control vulnerabilities. They also demonstrate that techniques for identifying framework customization-induced vulnerabilities can be adapted to emerging Android-based platforms such as Android Automotive OS by accounting for platform-specific differences. Beyond these immediate contributions, this work opens two broader research directions. First, the contextual features explored in this work may not be exhaustive. Future research should aim to identify additional contextual signals—potentially through automated discovery—and explore an integration framework that makes it easy to incorporate new analyses into a unified solution. Second, the adaptation of these techniques to other Android-based platforms remains an open challenge. While AutoAcRaptor demonstrates feasibility for Android Automotive, other platforms such as Android TV, Wear OS, and Android XR present unique differences that require dedicated investigation to determine how well these methods generalize and what extensions are needed.
Pragmatica: A VR Tool for Autonomous Practice During Language Therapy
(University of Waterloo, 2025-12-23) Prasad, Karthik
Aphasia is a communication disorder that affects millions worldwide, but those affected by aphasia have limited access to in-person therapy. They compensate for this with at-home practice, but existing tools are either ineffective or require a clinician to be present. We present Pragmatica, a VR platform that enables people with aphasia to practice their communication skills independently at home through immersive, context-rich activities. In an eight-week case study, we compared Pragmatica with traditional therapy (4 participants per group). With no detected difference in Quick Aphasia Battery (QAB) scores, VR participants engaged in substantial practice (31 hours, 366 activities) and described the VR experience as engaging, fun, and motivating, but had a limited variety of relevant and unique activities. Our study contributes empirical evidence of VR’s feasibility for autonomous language practice, as well as design insights and considerations for accessible, aphasia-friendly VR systems (flexible controls, multi-modal prompts and inputs).
Understanding International Graduate Students' Housing Experiences.
(University of Waterloo, 2025-12-23) Mohammed, Saluhu
The global rise in international graduate student mobility has intensified housing pressures in host cities, exposing gaps in institutional support and affordable housing provision. In Canada, particularly in Kitchener/Waterloo, Ontario, international graduate students experience growing difficulty securing adequate and affordable accommodation. Despite their financial and academic contributions, this group remains underrepresented in housing policy and planning research. The main problem addressed in this study is the mismatch between increasing international graduate enrolments and the inadequate housing infrastructure and policies designed to meet their needs. Existing research focuses largely on undergraduate student housing or general urban affordability, leaving a significant research gap concerning the lived experiences of international graduate students and the structural factors shaping these outcomes. The study draws on Housing Pathway Theory (Clapham, 2002, 2005) as its primary theoretical framework, emphasizing housing as a dynamic, non-linear process shaped by the interaction between individual agency and structural constraints. To enhance explanatory depth, the study integrates Bourdieu’s conceptual triad of habitus, capita, and field (1984,1986). This combined framework highlights how different forms of capital, economic, cultural, and social interact within the housing field to influence students’ pathways, constraints, and adaptive strategies. Together, these theories explain how international graduate students navigate the tension between structural housing limitations and their personal resources, revealing how inequalities in capital shape distinct housing trajectories. The research employed a mixed-methods, cross-sectional and case study design. Primary data were collected through an anonymous online survey and follow-up interviews to international graduate students who opted to be interviewed. Purposive and snowball sampling yielded 125 valid responses from an initial 136. Quantitative data were analyzed descriptively using SPSS (Version 28) to identify patterns of affordability, accessibility, and housing satisfaction, while qualitative responses underwent thematic analysis using NVivo 15 to interpret lived experiences and coping strategies. The major findings reveal that international graduate students face acute housing precarity, with affordability, discrimination, and limited information networks as central challenges. High rents and the dominance of PBSA developments have marginalized students with limited financial capital. Cultural and social capital strongly influenced housing outcomes: those with local networks or prior Canadian experience navigated markets more effectively. Many respondents reported overcrowded, temporary, or substandard conditions that negatively affected their well-being and academic performance. The findings also expose structural inequalities embedded in municipal housing markets and institutional policies, which privilege domestic or undergraduate cohorts. Policy implication highlights the need for universities, municipal authorities, and provincial housing agencies to develop integrated housing strategies that recognize international graduate students as a distinct and vulnerable demographic. Recommendations include expanding affordable housing supply through university–municipal partnerships, improving access to tenant education and legal resources, and ensuring that institutional housing policies reflect the diversity of students’ economic and cultural needs. By centering international graduate students lived experiences, this study contributes to academic discourse on housing inequality and provides actionable insights for designing inclusive and sustainable student housing frameworks.
Computational Insights into the Corrosion Behavior of NbTaMoW and NbTaMoWV High-Entropy Alloys in Molten Fluoride Salts
(University of Waterloo, 2025-12-23) Katai, Agnes
Molten salt reactors (MSRs), one of the six next-generation nuclear reactor designs, employ molten fluoride salts as the coolant and/or fuel solvent when operated in a thermal-neutron spectrum, and offer higher thermal efficiency compared to today’s water-cooled reactors. Nonetheless, the elevated temperatures, corrosive nature of salts, and high neutron irradiation in MSRs create a harsh environment for structural materials. The influx of impurities, namely moisture, into the molten salt medium has long been shown to exacerbate the corrosivity of fluorides. Owing to their superior thermal and mechanical robustness, refractory high-entropy alloys with a body-centered cubic (BCC) structure have been proposed as candidate containment materials for MSRs. Nonetheless, the degradation of these advanced materials in molten fluorides is an intricate process whose underlying mechanisms remain poorly understood. This study explores the corrosion behavior of BCC (100)-NbTaMoW and (100)-NbTaMoWV surfaces in pure and hydrated FLiBe salt via density functional theory and ab initio molecular dynamics simulations. Electronic structure analyses, including density of states and crystal orbital Hamilton population, provide insight into the interfacial bonding and charge transfer. Irrespective of salt purity, NbTaMoW exhibits minimal d-band shifts which highlight its electronic stability, and weak interactions with fluorine and oxygen. The addition of vanadium to form NbTaMoWV further diminishes susceptibility to oxidation and enhances stability at the salt interface, suggesting superior corrosion resistance in both pure and hydrated salt.
Fade to White: Constructions of Racial Subjectivity in (Digital) Photography
(University of Waterloo, 2025-12-23) Kim, Jin Sol
This dissertation draws on scholarship from Critical Discourse Studies, Digital Media Studies, Critical Race/Black/Postcolonial Studies, Science and Technology Studies, and Visual Culture and Photography Studies to demonstrate how photography is a primary medium for producing racial discourse. The aims of my research are twofold. I analyze how photographs operate as discourse by identifying the specific frames of racial subjectivity that were formed during Western modernity. I also examine how the particular camera technologies and dominant visualization practices of select historical moments have affected the production of racial knowledge using analogue and digital photography. In Chapter One, I trace the early establishment of vision and epistemology, and more formally ocularcentrism, in Western culture. I outline this history to locate photography’s authority in producing visual racial discourse in Europe and America. I argue that photography, while an ostensible tool of objective representation, worked closely with the White European and American imagination to construct a racially coded image of ideal modern subjectivity. Building on Allan Sekula’s theory of bourgeois portrait photography and criminal mugshot photography as two poles of representation, I locate these dichotomous frames in three key photographic moments in Western history from the mid-19th to 20th centuries: colonial photography, eugenics photography, and lynching photography. In Chapter Two, I focus on productions of countervisual photographs from the same period as Chapter One. I specifically analyze exemplary photographs that depict unconventional images of Blackness, such as those linked to Black abolitionists Frederick Douglass and W.E.B. Du Bois, as well as representations of Blackness from American World War II propaganda posters and the Civil Rights movement. Building on Evelyn Higginbotham’s theory of respectability politics, I consider the interplay of these images with prevailing visual frames of White respectability and racialized deviancy. I argue that because these photographs replicate established codes and conventions of modern subjectivity, they struggle to introduce representations of racial heterogeneity into mainstream discourse. I propose that a shift is needed in photography’s accessibility and viewership to unlock its counter-discursive potential. The third chapter in this dissertation explores a genealogy of digital photography to situate shifts in photographic practice from analogue to digital photography. I assess how the development of increasingly mobile and networked photographic tools—that is, the integration of digital cameras with smartphones—led to the rise of social media photography as a new vernacular that allows personal photos, including previously unseen marginalized representations, to be seen by mainstream publics. Expanding on the works of Black Studies scholar Saidiya V. Hartman and postcolonial theorist Homi Bhabha, I identify photographs from the Black hashtag movements #IfTheyGunnedMeDown on Twitter and #BlackoutDay on Tumblr as examples of countervisual racial discourse using digital photography. In contrast, Chapter Four considers how White visuality has become coded into the algorithmic logic of social media, especially with the rise of augmented reality beauty (ARB) filters from 2015 to 2025. ARB filters are pre-set photographic templates that use a combination of camera and computer vision technologies to edit and ostensibly beautify a user’s digital image in real-time. Using feminist media theorist Anne Balsamo’s methodology of hermeneutic reverse engineering and Amanda K. Greene’s notion of glitchy vision, I identify how race is intertwined with and positioned within ARB filtering technologies and practices. I analyze 15 ARB filters from across Instagram, Snapchat, and TikTok to identify their specific areas of “augmentation.” I argue that ARB filters disguise their reproductions of Whiteness as a neoliberal tool of self-optimization, and thus produce forms of visual racial discourse that extend modernity’s racial ideologies into the algorithmic age. I end this dissertation with a reflection on work that remains to be done in examining photographs as racial discourse, especially as we navigate social media environments that are increasingly algorithmic in nature. I invite future discussions that will engage culturally informed uses of digital photography and its role in constructing racial subjectivity and ideology online.
Experiencing Land-Based Nourishing: An Indigenous Evaluation of Urban Land-Based Food Education in the Waterloo Region
(University of Waterloo, 2025-12-23) Peach, Laura
Background: Across Canada, Indigenous communities have sustained their health and wellbeing through cultural practices enacting their knowledges and intimate connection with the Land. As a health promotion strategy reflecting these concepts of wellbeing, many communities are using Land-based learning models to situate culturally-therapeutic and educational experiences that foster pathways towards wellness. However, few studies have evaluated these activities to determine their success, particularly in urban community contexts and with Indigenous children. Objectives: The purpose of this dissertation research is to examine whether Land-based learning approaches to food education for children within an urban setting enhances participant food literacy. Collaborating with two urban Indigenous organizations in the Waterloo Region, Ontario, Canada, this examination extends across three studies that address more specific questions concerning this phenomenon. Specifically, the objectives of this study were to: develop a culturally and locally responsive evaluation framework for WONAA and WC’s Land-based learning programs with a focus on food education; document and evaluate the process and outcomes of a Land-based learning program among urban Indigenous children; and, synthesize findings across studies to renew the initial co-constructed program theory, examining key lessons from implementing a Land-based food program towards reconceptualizing food literacy within an urban Indigenous context. Methods: Using a community-based Indigenous evaluation approach, the articles of this dissertation use diverse qualitative methods informed by relational Indigenous methodologies and realist philosophy to co-construct a culturally responsive program theory, assess a Land-based pilot program, and synthesize findings to put forth a reconceptualization of food literacy as a community-determined, context-specific health promotion concept. Iterative group discussions, participant observation, and photo elicitation methods were used with purposive samples of Indigenous community experts, program facilitators, and child program participants. Results: Findings from Study 1 report a novel methodological approach using iterative sharing circle conversations with diverse, partner-identified community experts to co-construct a culturally and contextually appropriate program theory as the first step in the wider evaluation project. Guiding conversations through four thematic topics were found to concurrently support the planning of both the program and its evaluation through theory co-construction. An initial program theory is presented as a theory of “Land-based nourishing”, which portrays a nascent process of becoming well with food instead of pre-determined or predictable outcomes to be anticipated at the outset of a program. This iterative conversational method also enabled a reframing of evaluation itself as a cycle of responsibility, which reflects the values of Indigenous organizational partners. These insights were applied in Study 2 to identify the context, mechanisms, and outcomes of Sweetwater Camp, a children’s Land-based pilot program. Evaluation results highlight an emergent program context characterized by a process of “giving over to the land,” in which facilitators responded to unpredictable natural conditions in positively adaptive ways that acknowledged more-than-human actors as program co-facilitators. Key mechanisms delineate “the strength of relational implementation” where Camp activities and participant behaviours established ways of learning through collaborative facilitation and meaningful connection by engaging in risky play and fostering a sense of belonging among child campers. Program outcomes were found to be “whatever, however we were gifted, happened,” denoting the inconclusiveness of early indicators of program impact including participant development of new skills and knowledge and the formation of deepened relationships with all program participants in ways that could not be planned for. The results of Study 3 synthesized findings from the prior two studies to demonstrate the limited relevance and applicability of the conventional term, ‘food literacy’. Rather, participants from both preceding studies renewed the initial conceptualization of “Land-based nourishing” proposed in Study 1. Aggregated data clearly articulate the meaning of this contextual health concept with symbolic representation gleaned from child-produced photographs. Land-based nourishing, as such, was understood as a personally unique process of developing a dignified sense of wellbeing through practicing key relational principles, engaging in a variety of skills and knowledge that respect the Land as the greatest teacher, and cultivating a spiritual link with food itself. Together, these studies chronicle an evaluation journey of co-creating an organizationally distinct Indigenous evaluation approach that captures the strengths of Land-based food programs for urban Indigenous young people. The final article, a discussion paper, reflects on this process by considering current ethical guidance around relational research conduct. In this reflection, several taken-for-granted assumptions and ethical dilemmas are explored and followed with suggestions for navigating and preventing some relational challenges that could be encountered when trying to do Indigenous research ‘in a good way’. Conclusion: The articles included in this dissertation make several methodological, theoretical, and substantive contributions to the literature as well as public health practice and policy by reporting the creation and implementation of a distinct Indigenous evaluation approach. This research used a unique program theory co-construction methodology, assessed an urban Land-based children’s program, and concurrently reconceptualized a nutrition promotion concept reflecting shared community values and context. Jointly, these works demonstrate that relationships matter to nourishing wellness with and through food.
Centenary Republic Day in Istanbul: Eventification of Urban Public Space during a National Day of Celebration
(University of Waterloo, 2025-12-23) Kuzuoglu, Sina
Centenaries represent a significant milestone for nation-states as politically valuable occasions that permeate across public sphere(s), public realm(s), and public space(s). This dissertation examines the centenary of the Republic of Turkey in 2023 by investigating (1) the competing political visions about the state and the society; (2) the centenary’s representation in the mediascape; and (3) public space animation projects in Istanbul by two public institutions aligned with different political factions: the President’s Office and Istanbul Metropolitan Municipality. Using critical event studies and public value theory, this study first focuses on the discursive influences on the construction of the nation, the centenary Republic Day, and the publics at centenary-related events. To this end, it adopts a discourse-analytic approach using speeches from the leaders of main political factions in Turkey during the 2023 election period, and a frame analysis on writings about the centenary published in national newspapers by different media factions. It then examines how public space animation projects of the two public institutions materialized by focusing on the publicness of three animated urban spaces. Through a qualitative analysis of primary visual data, a descriptive account of the parameters of access, security, and design as they are conceived by public institutions and experienced by individuals is provided. While the centenary was commonly positioned as a nation-unifying phenomenon, this study demonstrates that the pre-existing and continuously evolving polarizing mechanisms in politics, media, and society were integral in the construction of the nation and the publics at the events. As such, public space animation projects took significantly different forms. The presidential project, on the one hand, was a spectacle of hard power that deployed recent achievements for passive consumption. On the other hand, the municipal project was a partially interactive celebratory event that positioned the centenary in its historical context. Furthermore, the presidential spectacle aimed to use existing urban amenities without any specific boundaries demarcating the public gathering from the everyday life of the city whereas the municipal event was mostly isolated from its surrounding areas with self-sustaining amenities. The municipal event offered higher flexibility to urban inhabitants’ interactions with the space although the space was less public on a conceived level in terms of its formal features like access and securitization. While publicness is often interpreted through physical spatial features, the experiences on the centenary underscore the decisive influence of symbolic and social features on perceived publicness.
Smart Light Therapy Glasses for Sleep, Cognition, and Mental Wellness
(University of Waterloo, 2025-12-23) Tang, Lucas
For the past century, people have gradually transitioned to spending their time indoors where, compared with the outdoors, light levels are significantly lower during the day and higher at night. This mismatch of lighting has been associated with related health problems like rising depression rates and sleep issues. As such, bright-light therapy has been established as a treatment for mood and sleep disorders. However, existing devices face major barriers to adoption; light boxes require people to stay in one place for a long time, and wearable products often lack social acceptability. As a result, the research literature has been constrained to short interventions with limited exploration of dose, duration, and individualized understanding of response to light. This thesis presents the design, engineering, and clinical evaluation of a pair of smart light therapy glasses (Lumos glasses) developed to improve convenience, social acceptability, and comfort. The hardware provides the foundational infrastructure for an intelligent, data-driven approach to personalized circadian health. The glasses use a nanotechnology lens with wavelength-based reflection, which allows key light therapy components to be compacted into a classic glasses shape. A hardware-software platform was developed featuring calibrated light therapy optical systems, on-device sensors for reliable wear detection, melanopic ambient light detection, an FCC-approved Bluetooth module with a custom antenna, as well as a compatible cloud-connected mobile app. More than 100 units were manufactured and deployed in a double-blind, randomized, placebo-controlled crossover clinical trial. Participants receiving bright-light showed significant improvements in sleep disturbance (PROMIS) and psychomotor vigilance (PVT) relative to active dim-light control. Stratified analyses revealed that participants with darker eyes generally exhibited more significant improvements under bright-light compared to dim-light control. In contrast, mood (using the Montegomery Asberg Depression Rating Scale) and working memory (word-pair recall) reached statistical significance only after accounting for eye color. Exploratory models also showed that daily use and exposure to ambient light were correlated with improved outcomes, while higher baseline severity strongly predicted room for change. Age and sex contributed smaller, secondary effects. For working memory, dark-eyed participants showed significant Phase~1 gains under bright-light, while other subgroups demonstrated positive associations between daily usage and recall performance. This yielded meaningful insights that adherence and individual pigmentation influence optimal light dosage. This work demonstrates that mobile sensor-driven light therapy can overcome long-standing adherence barriers and enable in-depth research about dose–response and personalization. By combining engineering innovation with clinical validation, the Lumos Smart Glasses provide a foundation for next-generation circadian health technologies that are practical, effective, and scalable.
The Enhancement and Optimization of CO₂ Sequestration in Saline Aquifers
(University of Waterloo, 2025-12-23) Firoozmand, Hasti
Geological storage of carbon dioxide in saline aquifers is widely recognized as a key strategy for achieving long-term emission reduction. Its effectiveness depends on the accurate estimation of storage capacity and the ability to enhance and optimize that capacity through engineering design. Yet these objectives remain challenging due to geological heterogeneity, limited subsurface data, and the need to manage reservoir pressure within safe operational limits. Reliable evaluation therefore requires methods that integrate geological characterization with pressure behavior and injectivity constraints while also identifying strategies that expand storage potential without compromising formation integrity. This thesis develops an integrated framework for evaluating, enhancing, and optimizing CO₂ storage in saline aquifers through a combination of conceptual, analytical, and numerical methods. The research begins by developing a systematic approach for generating credible CO₂ storage estimates that progress from regional-scale capacity to scenario-specific storage potential under any level of data availability. Existing estimation techniques are organized into a six-tier framework that connects static, analytical, and numerical methods within a single adaptive workflow. Designed as a practical decision-support tool, the framework guides users in selecting appropriate methods, inputs, and model complexity based on available geological and operational data. This structure enables early-stage screening and iterative refinement as more detailed geological and operational information becomes available. Application to the Nisku Formation in Alberta (Canada) validated the methodology and confirmed that pressure-constrained, uncertainty-aware estimates can be obtained from limited data and progressively refined toward realistic operational outcomes. Building on this foundation, an analytical optimization model was developed to extend analytical methods to coupled injection and brine production, allowing direct technical and economic assessment of storage enhancement through pressure relief. The model incorporates transient pressure behavior and economic parameters to evaluate how well spacing, the number of wells, the production-to-injection ratio, and carbon revenue together influence storage capacity and project net revenue. Since the interaction among these parameters is complex, the model serves as a rapid diagnostic tool for understanding their combined effects and for testing different design configurations under varying geological and economic conditions. Validation against numerical simulations for both multi-well injection and brine-production scenarios confirmed that the model provides a fast and reliable means of screening and comparing sequestration project designs. The thesis next evaluates horizontal injection as another means of enhancing CO₂ storage efficiency in saline aquifers. Numerical simulations were performed to examine how horizontal wells influence pressure distribution, plume evolution, and overall injectivity across different geological and design conditions. Results show that longer horizontal wells improve lateral CO₂ distribution, reduce near-wellbore pressure buildup, and delay plume contact with the caprock, thereby increasing effective storage capacity. However, the gains in capacity and pressure control diminish beyond a certain lateral length, indicating an economic threshold for well extension. Simulation results also indicate that formation permeability, anisotropy, and thickness strongly influence the magnitude of achievable improvement over vertical wells, with the most significant gains occurring in low-permeability and thin aquifers These findings provide practical guidance for optimizing well design to achieve efficient and stable storage performance. Finally, the tools and insights developed in this research were applied to the Cambrian Formation in Southwestern Ontario (Canada), a regionally extensive but data-scarce potential storage target near major emission sources. The framework structured the workflow for estimating capacity under data limitations, while the optimization and enhancement studies informed the treatment of injectivity and pressure constraints. The analysis progresses from formation-scale capacity estimation to single-well performance evaluation and the application of enhancement strategies, providing a clear understanding of both inherent and improved storage potential. Results indicate an effective regional capacity of about 0.6–1.1 Gt of CO₂, limited by pressure tolerance and a single-well storage potential below 0.5 Mt per year. Incorporating optimized horizontal wells and controlled brine production shows that these strategies can be highly effective in this region, where single-well performance remains below established industrial benchmarks. Together, these contributions provide an integrated pathway for the evaluation, enhancement, and optimization of CO₂ storage in saline aquifers. The research bridges theoretical estimation and practical implementation, offering defensible capacity ranges, efficient design-screening tools, and clear strategies for managing pressure and injectivity in support of secure, large-scale geological storage deployment.
On the origins of prompt features in time-resolved laser-induced incandescence measurements of metal and carbonaceous nanoparticles
(University of Waterloo, 2025-12-22) Robinson-Enebeli, Stephen
Synthetic nanoparticles have become highly beneficial in many applications, including, for example, catalytic conversion, enhancing the functionality of electronic devices, targeted drug delivery in medicine, and purifying water through the removal of bacteria and heavy metals. Nanoparticles are often synthesized through gas-phase synthesis, where the nanoparticles are formed in a bath gas, resulting in a nanoparticle aerosol. Such aerosols are also unintentionally emitted through processes such as welding or combustion. The benefits and negative impacts of nanoaerosols significantly depend on their properties, such as particle size and concentration. Laser and optical-based characterization techniques can provide such information in an in situ and time-resolved manner. Time-resolved laser-induced incandescence (TiRe-LII) is a widely used laser-based diagnostic for soot characterization and is increasingly being applied to non-carbonaceous nanoparticles. The technique involves heating nanoparticles in an aerosol to incandescent temperatures with a laser and recording their radiative emissions with a photodetector, as they cool to the temperature of the bath gas. Nanoparticle properties such as size and concentration are obtained from temporally- and spectrally-resolved measurements through inference techniques that involve regressing a TiRe-LII instrument model to the data. Accurate and reliable inference of the nanoaerosol properties relies on the robustness of the instrument model. Unfortunately, previously developed models do not fully describe experimental observations, and the reported discrepancies need to be reconciled to improve fundamental understanding, modeling capabilities, and ultimately measurements. These discrepancies include effects previously termed excessive absorption and anomalous cooling. The effect of excessive absorption is observed when the measured particle temperatures exceed the values predicted by the related model, and the anomalous cooling was related to the effect that occurred when the measured particle cooling rate, immediately following the peak-temperature phase, is faster than what is predicted based on the model. This thesis work addresses these reported data–model discrepancies, providing insight into laser–nanoparticle interactions in the context of TiRe-LII and the impact of certain experimental conditions. In particular, it is shown that for metal nanoparticle aggregates, radiative properties are enhanced compared to isolated metal nanoparticles, and laser energy absorption becomes spatially nonuniform within aggregates. Under laser heating, the primary nanoparticle may melt; subsequently, the aggregates may partially sinter or coalesce, which further alters their radiative properties as a function of time, phenomena that do not occur in the case of soot. Furthermore, the existence of nanoparticles of different sizes within the aerosol and spatial energy variations across the irradiating laser sheet influence the data in ways that are not accounted for in current TiRe-LII instrument models. The investigations combined theoretical modeling and experimental work. The modeling utilized several light absorption models to explore the light–matter interactions between nanoaerosols and the electromagnetic field of the laser. The experimental component employed calibrated, time- and spectrally-resolved detection techniques to observe the radiative emissions from irradiated particles within the aerosol. The findings of this thesis contribute to a deeper understanding of laser–nanoparticle interactions and open new avenues for further research in this area.
Advanced venous flow dynamics and return mechanisms during physiological stress and aging
(University of Waterloo, 2025-12-22) Cohen, Jeremy
Human veins are dynamic vessels responsible for managing return of blood to the heart. Unlike arteries, veins are structurally limited, creating exceptional hemodynamic susceptibility to hydrostatic forces and pressure generating forces. The precise extent of venous flow regulating mechanisms to these forces have implication for disease pathogenesis yet have been historically limited by technological tools. Thus, the purpose of this thesis is addressing the responses to hydrostatic volume stress, muscle pump activation and healthy aging through the piezoelectric lens of vector flow imaging ultrasound through a series of projects. First, progressive hydrostatic volume stress is applied to the internal jugular vein to address regional flow complexity and volume expansion behaviour. The internal jugular vein presented step-wise volume expansion in a trapezoidal shape and increasing flow complexity, increasing the risk for flow stasis and thrombus formation. Second, hydrostatic volume stress is used to compare artery-adjacent and non-adjacent veins to probe the existence of an arterial pump. During relevant hydrostatic driving forces, artery-adjacent veins demonstrated a preservation of venous flow, suggestive of a newly described mechanism of venous and an elegant conservation of mechanical energy within the cardiovascular system. Third, a comparison of younger and older adults leveraged differences in venous compliance to investigate flow complexity features during muscle pump activation during hydrostatic volume stress. Older adults were found to utilize their lower compliance to maintain venous ejection efficiency, whereas younger adults experienced great turbulence and vorticity flow features for the same venous outflow. Finally, venous valves were explicitly investigated during progressive hydrostatic volume stress and muscle pump activation to describe flow complexity features. Healthy valves generated efficient forward jets with downstream disturbed, low-shear zones, and volume stress amplified regional differences, underscoring the role of valve geometry in venous hemodynamics. Together, these studies establish new mechanistic links between venous structure, hydrostatic and muscle pump forces, and aging, advancing understanding of venous flow regulation and its implications for thrombotic risk and cardiovascular health.
Studies on the Characterization and Measurement Optimization of Superconducting Microwave Resonators
(University of Waterloo, 2025-12-22) Chen, Mengyang
This work presents a study aimed at improving the accuracy and efficiency of low-temperature loss-tangent measurements in superconducting resonators. Measurements were performed on aluminum and niobium devices, where a plateau in the internal quality factor at the single-photon level was observed, consistent with prior reports. By truncating the acquired resonance data, it was shown that the loss tangent experienced no systematic shift even when only four points spanned the resonance linewidth; the resulting increase in uncertainty was attributed to reduced effective averaging. Based on this result, an optimized data acquisition scheme was developed, reducing measurement time by a factor of four while maintaining approximately 1% accuracy. Further improvements were achieved through the use of a lower-noise HEMT amplifier, which reduced measurement noise and decreased acquisition time to 60% of the original. Additional circuit modifications showed that improved infrared shielding reduced total resonator loss, while the nonlinear behavior at high RF power was attributed to intrinsic device nonlinearity rather than external circuitry. Finally, crossover temperature measurements showed agreement with BCS theory at high temperatures, although its accuracy could be limited by not fully saturated TLS-loss, indicating the need for improved device designs.
Revisiting the ‘Lensing is Low’ Problem With UNIONS
(University of Waterloo, 2025-12-22) Campbell, Martine
In this thesis, we present new measurements of the galaxy–galaxy lensing (GGL) signal around Baryon Oscillation Spectroscopic Survey (BOSS) CMASS galaxies using background sources from the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS). With an overlap of approximately 2650 square degrees between CMASS lenses and background source galaxies—the largest to date—we obtain precise large-scale GGL measurements. With these new measurements, we revisit the so-called ‘lensing is low’ problem, wherein galaxy–halo connection models calibrated on clustering data over-predict the GGL signal by 20–40% under cosmic microwave background (CMB)-based cosmologies. We model the galaxy–halo connection using a halo occupation distribution (HOD), and perform joint fits to both GGL and clustering signals across a wide range of scales, as well as a clustering-only fit. Similar to previous work, we find a lensing–is–low effect in the CMASS sample, although our GGL and clustering predictions are less inconsistent with each other. The best joint fits are achieved by lowering the amplitude of the matter power spectrum relative to Planck 2018, driven by the precision of our large-scale GGL measurements. Once a lower matter power spectrum amplitude is adopted, feedback is the only HOD extension that further improves the joint fit. Our feedback model redistributes matter within a halo, modifying the halo–matter cross–power spectrum. Overall, we find that two models describe our observables equally well: one where HOD and cosmological parameters are free, and one where HOD, cosmological, and feedback parameters are free. Importantly, we emphasize the role of large scales in driving the lensing–is–low effect, shifting the narrative away from a purely small-scale issue.
Influence of Cellulose Nanocrystals and Surfactants on Catastrophic Phase Inversion and Stability of Emulsions
(University of Waterloo, 2025-12-22) Kim, Hyungseak
This thesis presents the first quantitative comparison of catastrophic phase inversion in emulsions stabilized by nanocrystalline cellulose (NCC) versus surfactants. NCC extends stability limits, raising the critical aqueous fraction from 0.253 to 0.545. Conversely, surfactants show non-monotonic behavior, delaying inversion at low concentrations and accelerating inversion at high concentrations. These findings demonstrate the effectiveness of NCC in high-internal-phase systems, validating its potential as a robust, bio-based stabilizer for industrial applications.
Exploring the Landscape of Sustainable Banking in Sub-Saharan Africa – Practices, Drivers and Outcomes
(University of Waterloo, 2025-12-22) Appiah, Adwoa Boatemaa
The role of the banking sector in advancing sustainable development worldwide cannot be overstated. Despite growing academic interest, the banking sector's perspective in Sub-Saharan Africa (SSA) remains underexplored, even though it plays a key role in the region's economy and finance. This dissertation addresses this gap by exploring the sustainable banking landscape, evaluating practices, drivers, and banks’ involvement with the Sustainable Development Goals (SDGs), using a manuscript-based format comprising three studies presented as Papers 1, 2, and 3. Collectively, these papers provide a deeper understanding of the integration of sustainability within the banking sector in SSA. Paper 1 employed a 44-indicator sustainable banking framework to assess the level of sustainable banking performance and its association with financial performance using a sample of ninety-nine (99) banks across six countries and was grounded in good management theory. Paper 2 extended the investigation by adopting a quasi-experimental design using country-level institutional environments as proxies to examine their relationship with sustainable banking performance across a sample of seventy-four (74) banks in six (6) countries underpinned by institutional theory. Paper 3 is anchored in legitimacy and corporate sustainability theories and applies a mixed-methods approach to examine the extent of SDG involvement by banks across sixty-one (61) banks in six (6) countries, providing a more comprehensive perspective on the motivations and challenges in aligning with a global sustainability agenda. Findings from Paper 1 indicate that most banks are in the initial and growth stages of integrating sustainability. The positive relationship between sustainability and financial performance underscores sustainable banking as a value creation strategy that should be encouraged. Paper 2 demonstrated that coercive, normative, and mimetic pressures are significantly and positively associated with sustainable banking performance, with coercive pressure from central bank regulations showing the strongest association. The findings from Paper 3 reveal low depth of SDG involvement but relatively higher breadth of engagement among banks that prioritize SDGs, aligning with their core business (13,8,5) and societal needs (3 and 4). This dissertation contributes to the application of good management, institutional legitimacy, and corporate sustainability theories in the sustainable banking literature, offers new insights into sustainable banking in a developing-economy context, and provides practical and policy recommendations to realize the full potential of the banking sector as a sustainability actor in the region.
Restless Legacies and Troubled Memories: The Historical Realities of the Organization of Ukrainian Nationalists
(University of Waterloo, 2025-12-22) Singleton, Robert
The turbulence of Ukraine’s contemporary political climate has resulted in a resurged admiration for the Organization of Ukrainian Nationalists (OUN) whose legacy is marred with accusations of ethnic cleansing, including participation in the Holocaust, subscription to fascist ideology, extended use of political violence, and alignment with Nazi Germany. Apologists for the OUN seek to deny these controversies, deeming them false and de-contextualized Soviet, Polish, and Jewish narratives. Critics of the OUN point to the extensive evidence against the OUN and argue that the opening of the Soviet archives before their subsequent closure only added evidence to their arguments. This thesis seeks to examine the major points of contention and test the validity of these interpretations.
Exploring Voice Agent Gender in a Running Coach Application
(University of Waterloo, 2025-12-22) O'Neill, Casey
In daily life, people commonly use voice agents such as Siri and Alexa to perform everyday tasks. With rapid technological advancements, voice agents are becoming more humanlike and there is a growing interest to use them in high-stakes tasks such as mental health advice and therapy. However, it is important to understand the potential harms posed by these voice agents of the future. This work focuses on gender-based social justice problems introduced by the widespread use of humanlike gendered voice agents, many of which disproportionately affect women due to the high prevalence of commercial voice agents that are female or ``female by default''. To contribute to an understanding of how to design gendered voice agents that reduce these potential harms, we explore reactions to a gendered voice agent running coach. We build a voice agent running coach system for smartphones that includes three voice options (male, female, gender ambiguous) which we validate through an in-person survey study (n = 30). We use our system in a field study (n = 18) in which participants run with the agent for three weeks and attend two in-person or online sessions with the researcher. We present a statistical analysis of survey data and key themes from a reflexive thematic analysis of interview data from the study. We conclude with a discussion of actions designers can take to create gendered voice agents more responsibly. We also offer recommendations for future research into gender and gender-based stereotyping in voice agents.
Polymeric Oil Additives and their Small Molecule Analogues Studied via Pyrene Excimer Fluorescence
(University of Waterloo, 2025-12-22) Frasca, Franklin
Several series of pyrene-labeled small molecules (PySMs) and large macromolecules (PyLMs) were studied with pyrene excimer formation (PEF) through the analysis of their monomer and excimer fluorescence decays with either the model free analysis (MFA) or the fluorescence blob model (FBM). In these studies, the conformation and dynamics of the pyrene side chains of the PySMs were characterized with parameters such as the average rate constant () of PEF or the number (Nblob) of structural units inside a polymeric blob. These parameters were then compared to those obtained for the same PySMs after they had been incorporated into much larger macromolecules to generate PyLMs, whose specific pyrene-labeled subsections were probed by PEF. Since reports on the local pyrene concentration ([Py]loc), the values were compared for each PySM or PyLM in several organic solvents. Similarly, block copolymers (BCPs) were prepared where pyrene was randomly incorporated in a specific block, whose homopolymer analog had been characterized beforehand by PEF. Comparison of the PEF response of the homopolymer alone and incorporated as one block of a BCP provided information on the flexibility and dynamics of each specific block within the pyrene-labeled BCPs. The linear relationship between and [Py]loc established earlier for a variety of PyLMs was studied for a set of linear diols (Py2-DOs) and branched polyols (Py-POs), which were labeled through ester linkages with two or more pyrenes, respectively. increased more quickly with increasing [Py]loc for the Py2-DOs having a lower [Py]loc than for the Py-POs taking higher [Py]loc values, resulting in a clear breakpoint in the -vs-[Py]loc trends when transitioning between the two classes of PySMs. The effect was observed in the more polar solvents N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) and the relatively less polar solvents tetrahydrofuran (THF) and dioxane. The decreased sensitivity of toward [Py]loc for the branched Py-POs was attributed to the quickly diffusing pyrene side chains, which sterically hindered access to an excited pyrene from pyrenyl labels located further away on the chain. This effect reduced the effective [Py]loc sensed by an excited pyrene and yielded lower values. These results were further supported by calculating the theoretical th for the Py-PO samples based on the values of the Py2-DO samples. determined experimentally for the branched Py-POs was indeed lower than th as predicted from the lower [Py]loc sensed by excited pyrenes. A series of PySMs was synthesized by using amide linkages to attach 1-pyrenebutyric acid to diamines and polyethyleneamines to yield linear (Py2-DAs) and branched (Py-PA) molecules with two and more than two pyrenyl labels, respectively. Their values, determined in the same solvents used in the Py2-DO and Py-PO study, revealed that the polar solvents DMF and DMSO yielded a linear -vs-[Py]loc relationship without a breakpoint between the Py2-DAs and Py-PAs. However, a breakpoint was found in the -vs-[Py]loc trends in the less polar solvents THF and dioxane when transitioning between the Py2-DAs and Py-PAs, as had also been noted earlier for the Py2-DOs and Py-POs but in all solvents. This effect was explained by amide-solvent interactions which were favoured in the more polar solvents that enhanced the double bond character of the C-N bond in the amides, slowing their pyrene side chain motion and restoring access to all ground-state pyrenes of a Py-PA sample to an excited pyrene. The preceding results were used for comparison of the PEF response of a series of succinimide terminated polyisobutylenes (PIBSIs) having polyethyleneamine ends which were labeled with pyrene (PIBSI-PA-Pys) to resemble the Py-PAs of the previous study. Labeling the polyamine subdomains of the PIBSI samples enabled their detection through PEF and their vs-[Py]loc trends were compared with those of the Py-PAs. Since the PIBSI-PA-Pys were not soluble in the more well-behaved DMF and DMSO, their behavior was assessed in THF. Much lower values were obtained for the PIBSI-PA-Py samples than for the Py-PAs, but a linear -vs-[Py]loc trend was obtained that passed through the origin as dictated by the =kdiff×[Py]loc relationship. This linear trend provided a means for characterizing the polyamine blocks of PIBSI dispersants, which are often difficult to study by standard methods. The final study focused on poly(alkyl methacrylate) (PAMA) di-block BCPs synthesized through atom transfer radical polymerization with a poly(stearyl methacrylate) (PC18MA) and poly(butyl methacrylate) (PC4MA) block with pyrene randomly incorporated in either block. The flexibility of either block was characterized with the number (Nblob) of structural units a pyrene label could sense during its fluorescence lifetime through analysis of the fluorescence decays with the FBM. In good solvents for the BCPs, the Nblob values matched those predicted theoretically while in hexane, octane, and dodecane, which are poor solvents for the PC4MA block, the process of PEF was hindered whether pyrene was in the well-solubilized PC18MA block or the poorly solubilized PC4MA blocks. This effect suggested that interactions between the two blocks slowed dynamics compared to their well solubilized behaviour in the better solvents THF, toluene, and o xylene. The crystallization behaviour of the stearyl side chains in the BCPs was probed through their fluorescence spectra above and below their crystallization temperature. The results indicated crystallization-driven micellization of the BCPs through a closed-association mechanism. In summary, this thesis has probed an interesting set of PySMs with PEF to report on their internal dynamics and interactions with different solvents, while also illustrating how PEF can be applied to amplify the signal and probe the conformation and dynamics of subdomains within larger PyLMs in solution. These methods have a particular application for the study of polymeric oil additives which see widespread use in the lubricant industry.

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