Electronic Theses and Dissertations

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Energy planning with hydrogen deployment strategies within interconnected infrastructures using enhanced SWITCH model
(2024-07-01) Villalobos Herra, Elena; Gaber, Hossam
The water dimension is not adequately considered in energy models when planning for hydrogen technologies. To overcome this, three novel modules have been developed for the SWITCH energy model: one that considers water drinking systems, a second module that optimizes the size/location/type of hydrogen plants, and the buildings module to integrate buildings using hydrogen-based combined heat and power systems. The modules contribute to the research community by linking the water, hydrogen and power sectors in an energy model. The modules were tested in a case study for Durham Region, using data from 2022. The main results show that the zone of Oshawa is optimal for building a hydrogen electrolysis plant, but facing drastic changes in its power and water demands. Results also show hydrogen-based combined heat and power systems would not be economically feasible unless the price of hydrogen per kilogram is less than CAD$2.13, considering the 2022 parameters.
Examining women’s knowledge, health risk perceptions, beliefs and behaviours in relation to toxic chemicals commonly found in personal care and household products: a mixed-methods approach
(2024-08-01) Trifunovski, Adrianna; Barakat, Caroline
Many personal care and household products (PCHP) contain toxic chemicals harmful to health. For instance, parabens, commonly found in shampoos, are endocrine disruptors that increase the risk of hormonal and reproductive disorders among women. Despite safer alternatives, research suggests women are unaware of these risks and options. This research used a mixed-methods approach to examine knowledge, health risk perceptions, beliefs, and avoidance behavior of women regarding toxic chemicals in PCHP. It focused on lead, parabens, bisphenol A (BPA), phthalates, triclosan, and perchloroethylene. A questionnaire was administered to 200 women, and 10 women participated in virtual interviews. Multivariate analysis found positive associations between avoidance of lead, parabens, BPA, and phthalates and knowledge, perceived health risks, and harm beliefs. Higher education and chemical sensitivity diagnoses increased lead avoidance. Factors influencing PCHP purchases included price, social media, effectiveness, and brand preference. The study emphasizes enhancing women’s knowledge about PCHP health risks and the importance of safer alternatives.
Multi-omic analysis of contaminated sediments from Contrecoeur, QC on Planorbid snails
(2024-07-01) St-Laurent-Guérin, Jeanne; Gilroy, Ève; Simmons, Denina
Contrecoeur’s history of industrial development resulted in sediment contamination (by butyltins, heavy metals, and petroleum hydrocarbons), which can be harmful to aquatic and benthic life. Additionally, future development threatens to further exacerbate the contamination in the area. This study examines the effect of Contrecoeur’s contaminated sediment and increased water temperature on Planorbid snails’ survival, growth, reproductive output, metabolomic profile, and proteomic profile. A two-week in-situ exposure was performed on Helisoma trivolvis, and a 28-d laboratory exposure of Planorbella pilsbryi to the same sediments was completed. Snail tissue samples were collected for proteomic and metabolomic analysis. Sediment contamination caused mortality and affected the insulin signaling and the transsulfuration pathways. Thermal stress increased the effect of ammonia through urea metabolites and affected the abundances of guanidinoacetate, creatine, and creatinine. The other effects (on DNA translation and transcription, on energy metabolism, and on key biomarker proteins) cannot be attributed specifically to one stressor.
In pursuit of the good life: masculinity and reintegration
(2024-08-01) Stevenson, Alia M.; Harkins, Leigh; Cesaroni, Carla
Successful reintegration is not simply desistance from crime but a fulfilling life without crime. These studies utilize the Good Lives Model (GLM) and masculinity theory to understand barriers or facilitators to reintegration for previously incarcerated men. In Study 1, a sample of 35 previously incarcerated men were utilized to examine whether endorsement of masculine norms and achievement of goods in the GLM were related to perceived reintegration success. Results showed that self-reliance (i.e., reluctance to seek help) and emotional control (i.e., reluctance to share emotions) were negatively related to the achievement of goods in the GLM. In Study 2, 19 participants from Study 1 were interviewed to explore the above themes in greater depth. Barriers and facilitators consistent with Study 1 were observed, with self-reliance and emotional control emerging as key themes. The current studies highlight both positive and potentially problematic conceptions about being a man that could be applied alongside the GLM in reintegrative programming.
Bias and fairness in transfer learning
(2024-07-01) Salmani, Parisa; Lewis, Peter R.
Transfer learning involves using knowledge from one task to improve performance and reduce training time on a related task. However, recent studies highlight a critical issue: the fairness of models trained with transfer learning. One study showed that transfer learning can transfer intentionally planted biases from the source task to the target task. This thesis explores a different but equally critical problem: whether transfer learning can introduce new biases or lead to greater biases in the target task. Our investigation reveals that transfer learning can introduce varying degrees of bias in the target task that were not present in the source task. We examined two applications that commonly use transfer learning. Our findings indicate that, in both cases, transfer learning increases bias concerning sex, age, and race compared to non-transfer learning methods trained from scratch, which are nearly as accurate. These results emphasize the need for understanding the limitations and risks of transfer learning, especially in high risk domains like healthcare and security, and call for further research into conditions under which transfer learning introduces and amplifies bias.
Forced sterilization in the 21st century: A qualitative analysis of women's experiences in Canada
(2024-08-01) Morton, Mckenzie A.; Cesaroni, Carla
Among women’s reproductive rights issues, non-consensual sterilization (NCS) is commonly overlooked or mistaken as a historical issue, despite being prevalent today. While sexual sterilization can have benefits, it is traumatic when performed without consent. Research suggests that women belonging to marginalized groups – particularly racialized or cultural minorities, women with intellectual disabilities, impoverished women - have historically faced higher risks of NCS in Canada. To gain a comprehensive understanding of the scope of this issue, this study proposes a secondary analysis of the testimonies of women who have undergone NCS in Canada in the late 20th and early 21st centuries. Utilizing qualitative methodologies, the study identifies common themes in these narratives, which call particular attention to the systemic failures in Canadian healthcare ethics and practice, the psychological and cultural consequences of NCS, and the demand for justice by survivors. Feminist bioethics provides a critical framework, emphasizing the importance of intersecting social identities.
Development and evaluation of Nuclear-Renewable Hybrid Energy System simulator with load following
(2024-07-01) Lopes Alves Esteves, Otavio; Gaber, Hossam
This thesis addresses the integration and optimization of Nuclear-Renewable Hybrid Energy Systems (N-RHES) with a focus on Load Following (LF) capabilities. The primary aim is to enhance the operational flexibility of nuclear reactors to adapt to dynamic power demands. A dynamic simulation tool was developed for different nuclear reactor technologies, including Pressurized Water Reactors (PWR) and Molten Salt Reactors (MSR), enabling detailed analysis of reactor power behaviour under different Load Following scenarios. Additionally, a Nuclear Reactor in the Loop (NRiL) system was implemented for accurate real-time evaluation of control systems, providing precise assessments without the need for expensive and time-consuming physical tests. The final component, the Nuclear-Renewable Hybrid Energy System Simulator (N-RHESS), integrates an energy management system within the simulation environment, improving N-RHES designs and decision-making by allowing users to develop complex energy load profiles and assess the feasibility of integrating nuclear reactors. The research demonstrated significant improvements in the operational efficiency and economic viability of N-RHES, highlighting its potential to enhance grid reliability, reduce carbon emissions, and promote sustainable energy solutions. This work contributes to the field of energy systems engineering by providing innovative tools and methodologies for integrating and optimizing nuclear and renewable energy sources.
Consent and sexual assault in heterosexual versus same-sex sexual encounters
(2024-07-01) Kirkpatrick, Sarah M. M.; Emeno, Karla; Vettor, Shannon
Consent is a vital component of all sexual encounters, and its absence can lead to harmful sexual behaviours. Although the concepts of consent and sexual assault should be applied appropriately to all individuals, this may not be the case. This thesis examined whether public perceptions of consent and sexual assault differ based on participant gender and rape myth acceptance, as well as the sexual orientation of individuals portrayed in various sexual encounter vignettes. It also examined whether specific behaviours are perceived as universally consenting or non-consenting by participants. Results of this study suggest that the public can accurately identify consent and sexual assault, with little evidence for differences across heterosexual versus homosexual vignettes. However, male participants with high rape myth acceptance demonstrated diminished accuracy in identifying consent and sexual assault in certain scenarios. Several behaviours were found to be reasonably universally consenting and non-consenting by participants. Implications will be discussed.
A targeted reverse mapping machine learning approach for non-dominated solutions in multi-objective optimization
(2024-08-01) Kermani Poor, Masoud; Ibrahimi, Mehran; Rahnamayan, Shahryar
Multi-objective optimization problems aim to identify solutions that maximize or minimize conflicting objectives. Population-based multi-objective algorithms, inspired by biological populations, are effective but often provide limited solutions within the decisionmakers’ region of interest (ROI) on the Pareto front. Recent advancements in machine learning have shown promise in generating solutions, yet they suffer from a lack of control and require knowledge of objective function attributes. This study proposes a framework using Gaussian process regression and artificial neural networks to generate innovative solutions in the ROI. By employing diverse sampling techniques and integrating long term memory, the framework can produce more than twice as many solutions in the ROI, as demonstrated in experiments with real-world problems and various benchmark functions.
It gets better? Comparing the experiences of LGB and heterosexual Canadians
(2024-08-01) Janssen, Larissa; Cesaroni, Carla
LGBTQ+ individuals are a vulnerable population in Canada. Adolescence, being an important developmental period for identity development, is understood as particularly challenging for LGBTQ+ youths. With heightened rates of suicide for this population, claims like “it gets better” have been used to inspire hope and motivate young queer folks in the transition to adulthood. This thesis examines whether queer people’s lives truly do improve after adolescence. Using a nationally representative secondary data set, this thesis compares the well-being and life satisfaction of queer and non-queer individuals in adolescence, emerging adulthood, and adulthood. Results indicate that, on average, aspects of life do not improve soon after adolescence, and that, for queer participants, life did not improve until after emerging adulthood. This study provides insights into the complex developmental trajectories of queer Canadians and the need for more comprehensive support services in early adulthood.
Yeast-based impedance biodosimetry for retrospective assessment of radiation exposures
(2024-07-01) Hassan, Amna; Atkinson, Kirk
In the event of a radiological accident, conventional dosimeters are not always present or available to provide dose estimates. As such, retrospective dosimetry techniques can be used to determine the radiation dose to populations and the environment. This work investigates the feasibility of Saccharomyces cerevisiae yeast cells as fortuitous dosimeters for retrospective assessments of exposures following radiological accidents using impedance biodosimetry. The radiation response of S. cerevisiae was examined by using cellular metabolic activity and impedance as a means to evaluate dose. A novel dosimeter design was developed to allow impedance measurements to be performed on yeast samples. Simulations with Geant4 Monte Carlo code were conducted to explain the significance of the local environment and its impact on impedance measurements. It was found that yeast irradiated in the presence of various adjacent materials yield different impedance responses and the local environment influences the radiative energy deposition in yeast cells. This is due to the primary and secondary photoelectrons and Compton electrons that are produced within these materials, which contribute to additional energy deposition and increase damage to cells. This effect was exploited by adding an intermediate material in yeast samples to amplify the impedance signals. In this current work, aluminum grains were utilized as the standard intermediate material in yeast dosimeters as a controlled proxy for real world situations and for the purposes of mechanistic analysis and sensitivity assessments. To evaluate the feasibility of impedance biodosimetry, a dose-response curve was produced by irradiating yeast cells from 0:5 Gy to 8 Gy using a ¹³⁷Cs gamma source. The dose-response curve exhibited a linear relationship of dose with changes in the impedance response. Additionally, the lowest detectable dose that could be measured using this methodology was determined to be 300mGy. Fading of the impedance signal was also investigated, where no noticeable fading over a 7-month period was observed. Finally, the impedance response of Fleischmann's ® yeast was examined, and it was found that commercially available yeast cells exhibit a similar response to laboratory-grade yeast, as well as a radiation response. Based on these experimental findings, yeast cells were determined to be suitable to use for retrospective dosimetry applications since these samples are widely available and require no additional processing. Yeast-based impedance biodosimetry was determined to be an inexpensive technique that could be used in the event of a radiological accident to evaluate initial dose estimates to exposed areas. However, since the local environment considerably influences the energy deposition in cells, knowledge of materials that may be adjacent to yeast samples during the exposure is necessary to provide accurate dose assessments.
Modeling and analysis of all-season passenger car tire using finite element analysis
(2024-06-01) Fathi, Haniyeh; El-Sayegh, Zeinab; Ren, Jing
The performance of the ground vehicle is directly affected by its tire characteristics. Tires are the main components of the vehicle that resist all forces and moments generated during contact with the ground. Therefore, it is significant to better understand the effect of all tire characteristics on the tire-road interactions such as cornering maneuvers. In this research work, a 4-groove Continental Cross Contact LX Sport tire size 235/55 R19 101H is designed and modeled using the Finite Element Analysis (FEA) Technique. All tire layers are modeled separately with the corresponding reinforcement rubber layers with detailed geometry. The tire model is then validated using static and dynamic tests at various operating conditions. To achieve the accurate performance of the passenger car tire, the tread rubber is modeled under various temperatures and analyzed using hyper-viscoelastic models. The tire-road characteristics including rolling resistance, cornering characteristics, and traction are explained and investigated.
A hybrid approach for intersection management in V2X-enabled connected vehicles
(2024-08-01) Elmoghazy, Ammar; Elgazzar, Khalid; AlWidian, Sanaa
Autonomous Vehicles (AVs) have the potential to revolutionize transportation by enhancing safety, efficiency, and convenience. However, AVs face significant challenges in complex urban environments, particularly in accurately perceiving and navigating through intersections mainly due to occlusions. This thesis addresses these challenges by integrating Vehicle-to-Everything (V2X) communication with onboard sensors to improve AV perception and decision-making capabilities. In particular, this thesis proposes a hybrid centralized-decentralized management system, which maximizes the benefits of centralized control for strategic traffic management and the responsiveness of decentralized decision-making, using edge nodes as a traffic coordinators helps reduces the computational needs on the vehicle. Such a system leverages V2X data to enhance situational awareness, optimize traffic flow, and improve overall safety and efficiency in urban environments. The methodology involves using Simultaneous Localisation and Mapping - SLAM for mapping, particle filters for localization, and waypoint generation for planning and control. The hybrid system’s performance was evaluated through simulations and real-world experiments using scaled-down vehicles equipped with advanced sensing and communication technologies. Compared to purely centralized or decentralized approaches, the hybrid system achieved up to a 14% reduction in average travel times through intersections and a 20% improvement in overall traffic flow efficiency. This thesis contributes to the development of intelligent transportation systems by demonstrating the efficacy of hybrid intersection management in enhancing AV performance in urban environments.
Comparison of performance for visual feedback and cursors in mid-air grasping of 3D objects
(2024-08-01) Culver, Claire Madilyn; Kapralos, Bill
While investigating the performance benefits of visual feedback for grasping in midair interaction based virtual reality simulations, some studies noted that user performance in tasks has not improved when using visual feedback methods, while it has improved in other, similar studies. This thesis presents an experiment that was conducted to investigate the effectiveness of these techniques. The experiment itself involves a simple task that uses tools through a grasp and release mechanism, in a virtual environment that compares visual feedback methods used in other studies against techniques meant to inform the user of the bounds of the simulation in advance, known as feedforward techniques. Data collected finds that performance is not significantly impacted by either feedback or feedforward techniques, though feedback is preferred against a lack of feedback. Recommendations are provided to help minimize the use of visual effects on objects that may draw user focus from their intended target.
Exploring perceptions of barriers to sex and intimacy in an inpatient intimacy recovery service
(2024-08-01) Cressman, Calvin; Harkins, Leigh
This thesis explored service users’ and service providers’ perceptions of barriers to intimacy at Ontario Shores Centre for Mental Health Sciences. The service under investigation was Our Place—a clinical service room clients can book for intimate activities. Study 1 provided an overview of utilization rates for Our Place and asked clients to identify barriers that impacted their pursuit of intimate needs. Analyses were performed to investigate whether alleviating barriers could increase clients’ interest in using Our Place. Study 2 asked staff to identify barriers that impacted their ability to support the intimate needs of clients and identify resources needed to overcome them. Analyses were undertaken to investigate whether alleviating barriers or developing skills predicted increases in service providers’ abilities to support clients. The results of both studies suggest alleviating barriers and providing further resources can increase clients’ interest in Our Place and employees’ abilities to support their intimacy needs.
A multistage-constant-current, temperature-controlled, health-conscious fast charging algorithm for lithium-ion batteries
(2024-08-01) Chetri, Chandan; Williamson, Sheldon
The economical operation and wider adaptability of an electric vehicle (EV) is highly governed by the energy storage system used in the vehicle. To enhance user convenience and compete with their gasoline counterparts, EVs need fast charging methods to achieve equivalent refueling times. However, fast charging can adversely affect the health and cycle life of the battery due to excessive temperature rise resulting in accelerated degradation of the battery chemistry. Especially in subzero conditions, the chemical reactions are much slower, resulting in increased internal impedance. This leads to a higher rate of temperature rise in battery temperature and eventually faster battery degradation. This thesis proposes a closed-loop Multistage-constant-current, Temperature-controlled (MCC-TC), Health-conscious Fast Charging strategy, which modulates the charging current considering the battery temperature as feedback. The experimental validation on an automotive grade battery cell depicts lower temperature rise and rate of temperature rise following the MCC-TC charging algorithm compared to the conventional Constant-Current Constant-Voltage (CC-CV) charging algorithm.
Using non-targeted mass spectrometry to identify proteomic, metabolomic and lipidomic profiles in saliva to compare the impact of prolonged vs. interrupted sitting
(2024-08-01) Chauhan, Mohammed Faiz; Simmons, Denina
Traditional sedentary physiology research focuses on targeted approaches. To explore from a new perspective, a non-targeted approach with the use of Liquid Chromatography-Mass Spectrometry (LC-MS) to assess the responsiveness of proteins and metabolites in saliva to sedentarism was employed. The study involved 24 participants that engaged in both a prolonged sitting session and an interrupted sitting session, in a randomized order. Saliva samples were collected before and after each session, including a separate baseline. Samples were purified and concentrated then analyzed on the LC-MS. A total of 2493 proteins, 17 lipids, and 11 biogenic amines were detected. 2112 proteins were significantly differentially abundant among the different session sample groups. In conclusion, prolonged sedentary behaviour of 4 hours led to a range of molecular responses that were observed through changes in the relative abundances of proteins and lipids. The results were complex and suggestive of several indicators of health deterioration.
Developing a calibrated low fidelity model and an optimized sensor network using LIVE Digital Twin for pipelines in oil and gas industries
(2024-08-01) Bondoc, Andrew E.; Barari, Ahmad
Digital Twin (DT) solutions are at the forefront of intelligent prognostics and diagnostics of physical systems. The DT is the bidirectional communication between the physical and digital environments for better scheduling, manufacturing processes, health monitoring, etc. This communication is established with an optimized sensor network. LIVE Digital Twin (LIVE DT) is a novel methodology which addresses the lack of standardised DT solutions. This thesis employs LIVE DT to develop a calibrated Low Fidelity (LF) pipeline model. Three fault cases are rapidly simulated using the LF model to circumvent the need of expensive and dangerous physical experimentation. The developed data is used to develop an optimized sensor network for intelligent vibration monitoring of the pipeline. A machine learning algorithm is trained to detect the current fault experienced by the LF model. Furthermore, the presented methods and results can be scaled and customized to produce sensor networks for any physical system.
Exploring varsity athletes’ sleep characteristics: perspectives and implications of sleep on training, recovery, and athletic performance
(2024-06-01) Belchos, Melissa N.; Papaconstantinou, Efrosini
Introduction High-quality sleep is necessary for sports performance, physical and mental recovery from training, and preventing in-game fatigue. Varsity athletes may face additional challenges. Research Questions 1) What are the sleep characteristics of varsity athletes? 2) What are their experiences, views, expectations, and beliefs regarding the importance of sleep? 3) What can be hypothesized from the results of their sleep characteristics and perspectives? Methods We conducted a systematic review. MEDLINE, Embase, PsycINFO, CINAHL, and SPORTDiscus were systematically searched for primary studies published in English from inception to March 18, 2024. We included quantitative, qualitative, and mixed-methods studies. Results We screened the titles and abstracts of 1555 articles, of which 31 studies were included in this review. Conclusion Findings suggest that sleep quality may be lacking in collegiate athletes and that sleep duration may need improvement. This knowledge helps to identify future targets to improve the athlete's well-being, academics, and performance.
Detection of trace concentrations of small and big molecules through vibrational spectroscopy
(2024-08-01) Balasubramanian, Janani; Agarwal, Nisha Rani
In this thesis, we aim to detect analytes of varying sizes using surface-enhanced Raman spectroscopy (SERS) without the need for customizing the morphology of nanostructured substrate. Signal enhancement in SERS occurs near plasmonic nanoparticles within "hotspots" (<10 nm), which limits detection to molecules that can access these regions. We investigated two differently fabricated SERS-active substrates: pulsed laser deposited gold nanoparticles and electrochemically deposited silver nanoparticles, optimized for 633 nm and 532 nm Raman lasers, respectively. Characterization was performed using UV-Visible spectroscopy, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We analyzed zeatin, a small plant hormone (219 Da), and hemoglobin (Hb), a large protein (64,500 Da). Zeatin detection ranged from 1 mM to 1 nM, even in complex bacterial media, while Hb detection involved ligand-functionalized substrates targeting the heme group for specific oriented immobilization, detecting down to 10 nM. This study demonstrates the potential of SERS for sensitive and selective detection of diverse analytes, paving the way for advanced biosensing applications.

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