Proactive Characterization of Wildfire Impacts on Drinking Water Treatability

Forested catchments are important sources of drinking water globally. They are increasingly threatened by disturbances, prominently climate shocks, including large wildfires. Wildfires alter watershed hydrology and biogeochemistry, leading to reduced infiltration, increased overland flow, and enhanced delivery of sediments, burned vegetation, and pyrogenic material into aquatic systems. Such inputs can alter drinking water source quality and challenge treatability. Ash is the residual material from wildland fuel combustion, composed of mineral particles and organic matter that can leach into water. While inorganic dissolved compounds from ash can impact water quality by, for example, increasing ionic strength and alkalinity, water-extractable organic matter (WEOM) from wildfire ash contributes to increased post-fire dissolved organic carbon (DOC) concentrations. During drinking water treatment, higher DOC concentrations increase chemical demand (e.g., coagulant, disinfectant), enhance the formation of potentially harmful disinfection by-products (DBPs), cause taste and odor issues, and promote bacterial regrowth in distribution systems. These impacts may also necessitate new infrastructure to manage changes in source water quality, ultimately increasing overall treatment costs. Although they cannot reflect all watershed processes, bench-scale evaluations provide valuable insights into wildfire impacts on drinking water treatability by isolating treatment-relevant mechanisms at controlled laboratory conditions. However, different approaches used to prepare wildfire ash-impacted waters (WAIWs) limit the inferences that can be drawn from them. Here, key factors (e.g., mixing duration and condition, ash-to-water ratio, and source water quality) that can impact organic matter leaching from wildfire ash to water were investigated. WEOM concentration increased within the first 24 hours of mixing before plateauing or declining as mixing progressed, regardless of ash type and background water source. Continuous mixing yielded higher WEOM concentrations than stagnant conditions, indicating that particle-particle interactions and surface exposure enhanced leaching. WEOM yield also decreased as ash-to-water ratios increased. Despite anecdotal suggestions, a relationship between wildfire ash color and WEOM concentration was not observed (Chapter 2). Wildfire ash collection methods may also impact inferences drawn from bench-scale drinking water treatability assessments. Unburned vegetation, rocks, or other debris may have physico-chemical properties different from those of ash deposits; thus, increasing uncertainty in treatability assessments. Dry ash homogenization methods (i.e., manual separation, sieving, and pulverization) were investigated because they may mitigate these impacts. Sieving was shown to be the most practical and reliable method for ensuring ash homogeneity. Pulverization enhanced organic matter release from large particles by increasing surface area, but it also generated aerosolized ash, complicating sample handling. In addition, pulverization altered WEOM character, potentially by increasing the availability of smaller organic matter compounds previously encapsulated within ash particles or by mechanically fragmenting larger organic molecules into smaller compounds (Chapter 3). Subsequent investigations examined the role of settleable ash solids (SAS), a previously overlooked fraction of wildfire ash. SAS substantially increased water alkalinity and make pH control for coagulation extremely difficult. Although pH adjustment enhances DOC removal from WAIW, SAS increased acid demand substantially. The removal of SAS reduced both alkalinity and acid demand; however, as ionic strength was concurrently reduced, floc formation and turbidity reduction for a given coagulant dose decreased somewhat. A limited complementary analysis was conducted to evaluate whether atmospheric ash deposition could also act as a significant driver of source water quality and treatability change. While the impact of atmospheric deposition of ash on water alkalinity depends on the surface area of water body, only exceptionally high atmospheric ash loading could meaningfully alter source water alkalinity in reservoirs that hold large volume of water (Chapter 4). Wildfire ash alters multiple aspects of water quality concurrently, including turbidity, DOC concentration and character, and alkalinity, so its overall implications for water treatment cannot be adequately assessed by examining individual mechanisms in isolation. Coagulation experiments with WAIWs demonstrated these interacting impacts. At low coagulant (i.e., alum) doses, turbidity was effectively reduced, yet DOC removal remained limited, despite pH adjustment to coagulant-specific optima. Enhanced coagulation combined with higher alum doses improved DOC removal but introduced trade-offs, as turbidity reduction declined somewhat because of reduced ionic strength associated with decreased alkalinity. The results indicated, while wildfire ash can severely deteriorate water quality by increasing turbidity, alkalinity, DOC concentration, and aromaticity, which may increase coagulant demand or necessitate more advanced treatment methods, the underlying coagulation mechanisms for WAIW remain consistent with those in natural waters. Thus, wildfire ash does not present fundamentally new challenges to coagulation; rather, the magnitude of water quality changes following wildfire can pose risk to treatment performance and operational resilience (Chapter 5). Collectively, this research demonstrates that while bench-scale studies cannot fully replicate the complexity of post-fire watershed processes and wildfire impacts on water quality, they remain essential for isolating and investigating the specific effects of wildfire ash on drinking water treatment processes. Accordingly, it is practical to adopt methods that maximize the extraction of organic matter from wildfire ash and represent worst-case treatment scenarios. These methodological insights help ensure the comparability of bench-scale investigations. This work also shows that wildfire impacts coagulation primarily by complicating pH control and deteriorating drinking water source quality, increasing the need for more intensive treatment processes. Overall, this research establishes a robust methodological foundation for reliably assessing wildfire ash impacts on water quality and for informing the development of strategies to mitigate wildfire impacts on drinking water treatability

Modeling and optimal operation of sustainable thermoelectric microgrids with phase-change material thermal system

The final publication is available at Elsevier via https://doi.org/10.1016/j.segan.2025.101814. © 2025. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper proposes an Energy Management System for a thermoelectric microgrid that incorporates the modeling of a unique Phase-Change Material-based thermal system, capable of operating in both active and passive modes to minimize operating costs while guaranteeing thermal comfort, while properly considering the microgrid’s thermal power requirements and indoor temperature control. The proposed model also includes a detailed thermal representation of buildings to consider relevant thermal sources and room heat exchange, as well as heat pumps, water tanks for thermal storage, and battery degradation. A Model Predictive Control approach is used to address uncertainties in demand and environmental conditions. The proposed Energy Management System model is applied to the Energy Smart Home Lab microgrid located at the Karlsruhe Institute of Technology, in Germany, taking into account the specific characteristics of the microgrid’s components, expected energy consumption, and indoor temperature control requirements. Simulation results demonstrate the feasible application of the developed Energy Management System for the optimal operation of the actual microgrid considered, illustrating the thermoelectric microgrid’s power balance and temperature fluctuations of the associated components, with particular emphasis on the operation of the Phase-Change Material system, to showcase its active and passive thermal contribution under extreme weather conditions.This work has been supported by the Natural Sciences and Engineering Research Council of Canada (NSERC)

Beneath the Tracks

As of 2025, Vancouver is facing a worsening housing crisis, with homelessness rising sharply each year and vacancy rates remaining critically low. Given the city’s limited available land, it is essential to explore alternative spatial strategies. One such looked opportunity, lies beneath Vancouver’s elevated SkyTrain tracks - a space in which hundreds of commuters pass over every day yet remains underused. This thesis explores the untapped potential of these areas, reimagining them as prime locations for affordable housing that is targeted at young urban residents such as students, recent graduates and young professionals. To understand the viability of this housing strategy, four categories of international case studies relating to under-SkyTrain communities are explored: [1] Reclaiming Elevated Spaces, [2] Prefabricated Units, [3] Tiny and Flexible Spaces, [4] Communal and Landscape Engagement. Many of these categories overlap, with the central case study encompassing all four categories being the Chūō Line in Tokyo. It is a project that most closely parallels the thesis vision, which successfully integrates housing with community and commercial life beneath elevated rail infrastructure. As a fully realized and active project, it offers an example of what an under-SkyTrain development in Vancouver could become. Other examples from dense cities like Hong Kong and Paris show innovative responses to limited land, many of which are becoming increasingly relevant in a rapidly growing city like Vancouver. The thesis also examines local cases to see how these strategies might actually play out in reality. By examining the range of both global and local projects, the thesis identifies key design and planning strategies that may be applicable to Vancouver’s own spatial context and housing challenges. The following section considers how these spaces could be integrated in Vancouver, and what it means to build so close to transit infrastructure. It explores topics such as the Transit-Oriented Development (TOD) strategy, historical context of the SkyTrain and sound mitigation. The research, case studies, and context studies are ultimately synthesized into two design ideas that test how prefabricated housing and community can be integrated beneath the SkyTrain. The first explores co-living and retail near Metrotown Station (a high-density area), while the second looks at live-work housing around Royal Oak Station (a medium-density area). A lower-density site isn’t proposed, since those areas still have room to grow without needing to build under infrastructure like the SkyTrain. This thesis challenges the idea that dense cities like Vancouver have run out of space. It doesn’t claim to solve homelessness overnight, but it argues that under-bridge spaces shouldn’t be dismissed as leftover gaps. With a shift in perspective, they can become seeds for community

Housing Public-Private Partnerships in Toronto’s Regent Park

This thesis explores the evolution of public-private partnership (PPP) in Toronto’s housing development. PPP is defined as a legal and economic framework in which public and private sectors share resources, risks, and responsibilities in delivering projects or services traditionally managed by the government. The study first traces the model’s emergence in 1980s Toronto, where it arose as a response to fiscal constraints and administrative inefficiencies, particularly in infrastructure and affordable housing initiatives. After the late 1990s, the model was widely employed in Toronto to address housing challenges—leveraging public land and private capital to develop mixed-use, mixed-income, and mixed-tenure communities. These developments sought to combine private-sector efficiency with public-sector goals of affordability, spatial equity, and sustainability. Focusing on the redevelopment of Regent Park as a case study, this thesis critically analyzes the effects and limits of PPP-operated housing in contemporary Toronto. Originally constructed in the 1940s as Canada’s first public housing project, Regent Park faced decades of physical decay, social isolation, and stigmatization. In 2005, the Toronto Community Housing Corporation (TCHC) launched a major redevelopment to transform the area into a vibrant, mixed-income neighborhood. Drawing on archival research and fieldwork, the study investigates the collaboration among the City of Toronto, TCHC, and the Daniels Corporation at both political-economic and spatial levels. It assesses the model’s spatial manifestations, advantages, and shortcomings—particularly issues of gentrification, displacement, and placelessness—while situating the case within a broader international context of PPP-operated housing projects. Finally, through a design-based inquiry into the Phases 4 and 5 of Regent Park, the thesis proposes a new public-residential typology that seeks to dissolve the spatial segregation between market-rate and affordable units, mitigate placelessness, and foster community integration and historical continuity. In doing so, it offers a transferable design strategy for the global implementation of PPP models in affordable housing. This design proposal responds directly to the spatial and social limitations of the PPP model, offering a pragmatic intervention rather than a utopian vision. At the same time, it embeds a critical stance toward the neoliberal housing paradigm by reimagining the relationship between public and private, affordability and profit, architecture and equity

Exploring the Impact of Childhood Adversity on Adolescent Executive Function: The Role of Pubertal Timing

Adverse childhood experiences (ACEs) have been consistently associated with negative impacts on individual’s health and development including, but not limited to, changes in pubertal timing and the development of executive function; however, whether pubertal timing mediates the association between ACEs and executive functioning remains unknown. To address this gap, data was leveraged from a large-scale, nationally representative sample of American adolescents (Adolescent Brain Cognitive Development Study; N = 11,878, 52% male, 52.4% White, 13.4% Black, 24.0% Hispanic). Concurrent models assessed the integrity of adolescents’ core executive function abilities via their performance on tasks of response inhibition, working memory, and cognitive flexibility (baseline assessment; 9-10 years), whereas prospective models examined adolescents’ day-to-day executive functioning in life via parent ratings of their behavior (Time 5 follow-up assessment; 12-13 years). For females, but not males, earlier pubertal timing mediated pathways between greater ACE exposure and executive functions at both time points: at baseline, this was reflected in lower levels of performance on executive function tasks and at follow-up parent endorsement of executive function challenges in everyday living. These findings suggest there may be sex-specific pathways through which early adversity experiences impact subsequent development, with puberty emerging as a particularly important consideration for females vis-à-vis adolescent refinements in their capacity for cognitive self-regulation

Design, construction, and operation of a compact, ultrafast 100kV electron diffraction instrument

Elucidating the structure and properties of nanomaterials at greater resolutions necessitates the continuing development of novel imaging techniques. Electron imaging methods (such as electron microscopy/diffraction) are well-suited for probing matter at the nanoscale; for a given energy, the electron scattering cross-section is ~10⁵⁻⁶ higher than X-rays and ~10³ times less damaging [1]. Ultrafast electron imaging techniques are capable of spatial and temporal resolutions down to ~0.1 nm and 100 fs (femtosecond), respectively. This enables the observation of fundamental dynamic processes including photoinduced phase transitions, electron-phonon energy transfer, and the evolution of coherent phonons [2]. At present, open user access to the incredible power of these ultrafast techniques is generally limited to one ultrafast electron diffraction (UED) facility. Existing, well-established methods used to study nanomaterials such as X-ray diffraction and conventional electron microscopy have a plethora of commercially available, laboratory scale instruments which can be used to carry out experiments. In contrast, there are no similar turn-key devices that enable the study of ultrafast dynamic processes. The construction of an in-house ultrafast electron diffraction apparatus is one solution to the problem of instrument accessibility and the realization of time-demanding experiments with proper controls. In this thesis, I document the design, assembly, and use of a compact laboratory scale UED instrument. The instrument is capable of stable operation at 100 kV, with subsequent development and testing suggesting that it can reach voltages in excess of ~130 kV. The instrument is able to produce electron pulses with a temporal length of ~200 fs while containing a sufficient number of electrons for adequate signal-to-noise level. Two experiments were then carried out using the UED apparatus in order to showcase its time and spatial resolutions: electron deflection by photoinduced plasma, and the investigation of the charge density wave (CDW) material NbTe2. Analysis of the time-resolved diffraction data collected from the NbTe2 measurements suggests at 60 kV demonstrate sub-picosecond resolution in agreement with the predicted instrument response obtained from N-particle tracer simulations

Characterizing the Occurrence and Fate of Micropollutants in Aqueous and Environmental Samples: A Multidimensional Approach

Emerging contaminants such as pharmaceuticals and per-and polyfluoroalkyl substances (PFAS) present persistent challenges for environmental monitoring due to their chemical diversity, trace-level occurrence and limited removal in conventional wastewater treatment. This thesis presents a dual approach combining experimental two-dimensional separations with computational modelling to advance contaminant detection and mechanistic understanding. A targeted liquid chromatography-mass spectrometry (LCxDMS-MS/MS) method was developed and applied to complex pharmaceutical mixtures, revealing improved compound differentiation and class-based clustering across orthogonal retention time and compensation voltage dimensions. These trends demonstrate the potential of LCxDMS-MS/MS as a selective, high-throughput workflow for micropollutant screening in aqueous matrices. Complementary to this, quantum chemical calculations were performed on PFAS molecules, specifically perfluorosulfonic acids (PFSAs), to elucidate degradation pathways and assess the influence of molecular conformation on fragmentation energetics. Calculations identified several concerted and non-concerted reaction pathways that contribute to product selectivity. Together, these efforts establish a framework that integrates instrumentation and theory to support more informed contaminant analysis and method development

The Dependence of Halo Mass on Galaxy Size at Fixed Stellar Mass and Colour using Galaxy-Galaxy Lensing

To advance our holistic understanding of galaxy formation physics, we must examine the relationship between baryonic matter and dark matter (DM) within the universe. In this thesis, we investigate the correlation between dark matter halo mass and galaxy size at fixed stellar mass and colour. Using galaxy-galaxy lensing, we measure excess surface density (ESD) profiles for red, early-type galaxies from the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging survey, with shape measurements from the Ultraviolet Near Infrared Optical Northern Survey (UNIONS). We model the lensing signal using a conditional stellar mass function (CSMF) halo occupation distribution (HOD) calibrated on the AbacusSummit simulations and adopt a power-law relation between halo mass and galaxy size at fixed stellar mass: Mh ∝ r^ηeff . To fit the HOD parameters to the observationally measured ESD vectors, we train and utilize neural-network emulators, a form of non-linear interpolators. The analysis performed in this work follows a two-step process. First, we fit the HOD parameters to the ESD vectors corresponding to three stellar mass bins, not split further into two size bins. We freeze the best-fit HOD parameters and generate the corresponding best-fit mock catalogue. Using this best-fit mock catalogue, we apply our halo mass-size model and fit to the size-split observational ESD measurements. For central galaxies with stellar mass 10.5 ≤ log10(M⋆/M⊙) < 11.2, we find no significant correlation. At higher stellar masses, 11.2 ≤ log10(M⋆/M⊙) < 11.78, we detect a positive correlation with ηcent = 0.51 ± 0.14. A linear fit as a function of the logarithm of stellar mass yields a slope of sηcent = 0.66 ± 0.28, indicating that the halo mass-size correlation strengthens with increasing stellar mass. For satellite galaxies, we observe a negative correlation at low and intermediate stellar masses for the host halo mass-galaxy size relation of ηsat = −0.19 ± 0.05 and ηsat = −0.09 ± 0.05, respectively. The correlation is consistent with zero within the stellar mass range of 11.2 ≤ log10(M⋆/M⊙) < 11.78

Cross-sectional Analysis of Current Care Assessment Practices in the Retirement Home Sector in Ontario

As the population of Canada ages, some older adults often have increased multimorbidity, disabilities, and frailty. As a result, they are at an increased risk of hospitalization, accelerated functional decline, and earlier institutionalization. As they face more disability and health challenges, the lack of sufficient primary, community, and home care services to support them leads many to move into retirement homes. Once there, residents continue to experience health challenges, likely as a consequence of ongoing inadequate primary care and insufficient services geared toward their needs. Yet, addressing the unmet needs of retirement home residents at the individual and population levels is made challenging by the lack of standardized information collection. While regulatory agencies stipulate that residents undergo a health assessment, there are no specific requirements as to their nature. A better understanding of their unmet needs can potentially guide better primary care planning and help identify the level of services required to deliver better resident and system outcomes. To begin, current care assessment practices and processes surrounding these assessments must first be characterized and understood before the introduction of a new standardized instrument can be contemplated

Between the Covers and Beyond the Page: Gauging Climate Fiction's Impact through Ecocriticism and Virtual Book Club Observations

Despite increasing global concern about climate change, a gap persists between climate worry and action. Researchers across various disciplines and popular media suggest that narratives can motivate pro-environmental behaviour. Cli-fi novels, in particular, are believed to influence readers’ behaviours and perceptions of climate change. However, most evidence supporting these claims comes from classroom observations and traditional humanistic inquiry. In 2018, a new research methodology emerged, empirical ecocriticism, which set out to determine how general readers engage with these novels. This dissertation follows the principles of this method, namely, the combination of ecocritical analyses with empirical methods. To that end, the first part of this dissertation (Chapters 2 and 3) is an ecocritical examination of four diverse cli-fi novels published in the last decade to determine how they conveyed climate change information to their readers and how this portrayal may affect readers’ understanding of this issue. The second part of this dissertation (Chapter 4) is a report on empirical findings from a book club observation study of readers reading these same cli-fi novels. The two interdisciplinary objectives of this dissertation were to firstly examine how cli-fi novels relate information about climate change and what aspects of climate change are emphasized to readers in these novels, and secondly to contribute to the emerging field of empirical ecocriticism by reporting on how groups of readers discussed cli-fi novels and the climate change information therein. To achieve these objectives, I: (1) interpreted of four diverse cli-fi novels using ecocritical methods and (2) designed and implemented a book club observation study of general readers reading these same novels. Drawing on ecocriticism, climate change communication, and social sciences research, Chapter 2 introduces a new subcategory of cli-fi – ambivalent cli-fi. This subcategory is defined through an analysis of two realistic cli-fi novels Weather by Jenny Offill and Blaze Island by Catherine Bush to determine how climate change is portrayed in these novels and how their narratives might help readers explore their emotional responses to climate change. The novels were chosen due to their connections to the 2020s and the ecocritical analysis of these novels demonstrates that they can help readers sit in the uncomfortable space where the world is not yet irreversibly ruing, yet there is also no easy solution. Chapter 3 examines Blackfish City by Sam J. Miller and The Marrow Thieves by Cherie Dimaline, two speculative cli-fi novels, whose authors claimed they wanted their readers to feel hope despite narratives that portray radically altered environments and nightmarish societies. This chapter reviews climate change communication research that points towards more inclusive messaging favouring neither hope nor despair. The ecocritical analysis of the two novels utilizes Albert Camus’ notion of the absurd to address the feelings of existential crisis evoked by the novels’ depictions of climate change. It concludes by advocating for the creation of narratives that help audiences find ways to embrace futures that are neither apocalyptic nor utopic. Chapter 4 reports on virtual cli-fi book club sessions conducted from January to June 2022, involving 40 participants from across Canada. Participants read the same cli-fi novels discussed above in order to ascertain how ecocritical readings of these novels might differ from general readers’ interpretations. Pre- and post-survey data indicated that participants were younger than the average Canadian population (65% less than 44 years old compared to 42%), liberal, and concerned about climate change. The study identified three main themes from participant discussions: (1) the relatability of the cli-fi novels enhanced the believability of the story and climate change; (2) the presence or absence of hope was linked to whether novels included individual actions to mitigate climate change; and (3) participants experienced anxiety when they empathized with characters and scenarios. These findings suggest that readers use cli-fi novels to understand current climate issues. Results from the book club observation study also suggested that general readers in groups find solace and reach new conclusions through discussion. This discovery underscores the importance of considering reading as both an individual and social practice for empirical ecocriticism. The conclusions drawn from the ecocritical chapters highlight how cli-fi narratives have the potential to influence reader emotions. The arguments in Chapters 2 and 3 demonstrate that the negative emotions present in each cli-fi novel are necessary for readers to engage with and learn from. Chapter 5 concludes with a comparison of these arguments with the results from the book club study (Chapter 4). This discussion reinforces research from climate change communication and the social sciences that argues audiences (and readers) do not need to be frightened with catastrophic images of climate change dystopias. Instead, what readers (and non-scholarly audiences) might need now are stories that help them learn how to live-with climate uncertainty, and spaces to do this together