Minimal thermal treatment of cellulosic biomass to produce torrefied pellets

The production of solid biofuels from torrefied biomass holds significant potential for renewable energy applications. Pelletizing torrefied biomass offers advantages over its ground or loose form, though it often requires a binding agent to enhance pellet durability, thus increasing costs and energy use. This research aimed to produce durable pellets from torrefied loblolly pine (Pinus taeda) residues without using external binders or adjusting pelletization parameters, leveraging the benefits of torrefaction such as greater heating value and hydrophobicity. Experiments that involve various combinations of mild torrefaction temperature (230°C and 250°C) and shorter residence time (10, 15, and 30 minutes) across four particle size ranges (as-received, 1mm) were conducted to determine the effects of these factors on the physicochemical properties of the biomass. The torrefied materials were then subjected to pelletization, and the influence of torrefaction on the mechanical durability and fuel characteristics of pellets was examined. Thermogravimetric analysis of the pyrolysis and combustion behaviour of torrefied pellets indicated the improvement of fuel characteristics in terms of a higher comprehensive pyrolysis index and greater thermal stability with reduced risk of spontaneous combustion. The Response Surface Methodology (RSM) was employed for optimizing these factors to produce durable pellets from biomass, with an aim to minimize dry matter loss while maximizing the benefits of torrefaction. Results of RSM along with a predicted desirability of 0.674 indicated that the optimal treatment conditions are 250°C torrefaction temperature and 10 min residence time regardless of the particle size range. Under these conditions, the pellets can be produced with less mass loss at 14.5 wt% and pellet quality indicators which include single pellet durability of 63.4% that corresponds to tumbler durability of 87.1%, HHV (higher heating value) of 20.5 MJ/kg db, and EMC (equilibrium moisture content) of 12.5%. Overall, the study demonstrated that mild torrefaction temperature and shorter residence time preserved wood polymers, enhancing the physicochemical properties of the pellets, and enabling pellets to be produced with improved moisture resistance and fuel characteristics compared to untreated pellets. Besides, shorter torrefaction time would not only reduce energy consumption and operational costs but also minimize mass loss.Applied Science, Faculty ofChemical and Biological Engineering, Department ofGraduat

The development and evaluation of "Being There", an online well-being program for support networks of rural adults 50 years and older with mental health concerns

Social support in relationships is crucial for the wellbeing of adults aged 50 and older with mental health concerns (MHCs), particularly in rural communities with limited resources. Family and friends who provide this support, referred to as support partners, often feel overwhelmed and may benefit from additional resources. This dissertation includes two studies focused on the development and evaluation of Being There, a self-guided online program designed to improve support partner well-being and mental health literacy. The program included six modules that addressed psychoeducation, stress, coping strategies, communication, resources, and included community building components. Study I evaluated the feasibility and acceptability of the program in a small sample. Support partners of adults aged 50 and older with MHCs living in rural British Columbia (n = 9) completed pre- and post-program surveys and participated in a focus group. Overall, the program was found to be feasible and acceptable, though participants suggested changes to program content and logistics. Quantitative data showed variability in outcomes, consistent with qualitative feedback highlighting diverse individual needs in online learning. The program was revised based on this feedback. Study II evaluated the feasibility, acceptability, and effectiveness of the revised program using similar procedures. Participants (n = 21) again rated the program as feasible and acceptable, though learning needs and accessibility challenges varied. Qualitative feedback emphasized key takeaways and highlighted both strengths and weaknesses of the program’s social components, including Coffee Chats and the Discussion Board. Attrition analyses indicated that participants experiencing more emotional distress at baseline were more likely to drop out, suggesting that those who may benefit most from the program may also face greater barriers to participation. Paired samples t-tests revealed limited program effectiveness. There was a significant increase in mental health literacy and a trend toward reduced guilt about experiencing negative emotions towards others. Exploratory regression analyses found that improvements in communication and emotion regulation were associated with reductions in caregiver burden. Although the small sample size limited statistical power, findings underscore the importance of revising the program further to better support participants with elevated distress, and enhancing engagement through targeted skill development sessions.Arts and Social Sciences, Irving K. Barber Faculty of (Okanagan)Psychology, Department of (Okanagan)Graduat

WAVE2 and Tpm3.1/3.2 : actin dynamics, B-cell biology, and targeting B-cell lymphomas

Activation of the B cell requires dynamic remodeling of the actin cytoskeleton upon interaction with antigen-presenting cells. This enables cell spreading on antigen-bearing surfaces, immune synapse formation, and sustained B-cell receptor signaling. A central regulator of these events is the Arp2/3 complex, which drives the formation of branched actin networks in response to antigen stimulation. Of the nucleation-promoting factors that activate the Arp2/3 complex, the roles of WASp and N-WASp in B cells have been well-studied, but the contribution of WAVE2 has not been investigated. My work showed that WAVE2 and the Arp2/3 complex colocalize at the peripheral F-actin ring formed during B cell spreading. siRNA-mediated knockdown of WAVE2 led to impaired and delayed B cell spreading, reduced actin retrograde flow, and disrupted formation of actomyosin arcs. These defects diminished BCR signaling at the immune synapse and impaired B cell activation in response to antigen-presenting cells. In parallel, I investigated the role of tropomyosin isoforms Tpm3.1 and Tpm3.2, which stabilize actin filaments and regulate the recruitment of myosin. Tropomyosin function in B cells had not been studied previously. Using ATM-3507, a selective small-molecule inhibitor of Tpm3.1/3.2, I showed that disrupting Tpm3.1/3.2 function severely impaired BCR-induced actin remodeling, cell spreading, and actomyosin arc assembly, consistent with its localization at the cell periphery and actin arcs. Moreover, treating diffuse large B-cell lymphoma cells with ATM-3507 inhibited their growth, induced G2/M arrest, and reduced CXCL12-induced chemotaxis and motility on fibronectin. Collectively, these findings highlight WAVE2 and Tpm3.1/3.2 as key regulators of B cell actin architecture and B cell function, while positioning Tpm3.1/3.2 as a promising therapeutic target for B cell malignancies such as DLBCL.Science, Faculty ofMicrobiology and Immunology, Department ofGraduat

Comparison of patient-reported outcomes between the Invisalign® palatal expander and rapid maxillary expansion : a prospective clinical trial

Objectives: To compare patient-reported outcomes between the Invisalign® Palatal Expander (IPE) and the Rapid Maxillary Expander (RME) in children undergoing maxillary expansion, focusing on pain, discomfort, functional impact, and quality of life during the first two weeks of treatment. Methods: This prospective clinical trial included 60 children aged 7–12 years (30 treated with IPE, 30 with RME) from five orthodontic clinics. Participants completed structured questionnaires at 1, 7, and 14 days after appliance insertion, assessing pain, discomfort, functional limitations, and quality-of-life factors using visual analogue scales (VAS) and fixed-choice yes-or-no questions. Statistical analyses were conducted using parametric and non-parametric tests, with significance set at P < .05. Results: Both groups experienced similar overall patterns of improvement across the 14-day period, with most patient-reported symptoms decreasing to mild or moderate levels by Day 14. The IPE group reported slightly higher discomfort at insertion, while the RME group experienced more functional limitations such as chewing and speech difficulties in the early stages. However, these differences were not consistently statistically significant and not necessarily clinically significant. Both appliances were generally well tolerated after the initial adjustment period, and no serious adverse effects were reported in either group. Conclusions: Both IPE and RME are clinically acceptable options for maxillary expansion in children. Although there were some early differences in patient experiences between the two groups, both appliances showed favourable adaptation over time, with no major complications observed. These findings can help guide clinicians in setting realistic treatment expectations and discussing comfort considerations with patients and their families.Dentistry, Faculty ofGraduat

The river between Sohni and Mahiwal : fluid ecologies of genre, land, and gender in a Punjabi narrative tradition

The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.Arts, Faculty ofAsian Studies, Department ofGraduat

The equivalence and relative efficacy of psychodynamic psychotherapy and cognitive behavioural therapy for the treatment of adult depressive disorders : a meta-analytic test of active comparison randomized controlled trials

Meta-analyses comparing psychodynamic psychotherapy and cognitive-behavioural therapy (CBT) for depressive disorders are limited by heterogeneity in diagnostic samples, comparators, and a lack of equivalence testing. Additionally, extant meta-analyses on psychodynamic psychotherapy and CBT focus on standardized mean differences (SMDs) without examining potential differences in response rates, reliable change, deterioration, and acceptability (i.e., all-cause dropout). Objective: This dissertation addresses these gaps through a meta-analytic test of the equivalence and relative efficacy of psychodynamic psychotherapy and CBT for depressive disorders in the adult general population. Method: A comprehensive literature search across multiple databases using reliable screening methods identified nine active comparison randomized controlled trials (RCTs) directly comparing manualized psychodynamic psychotherapy (N = 572) and CBT (N = 509) for diagnosed depressive disorders in adults. Weighted pooled SMDs (Hedges’ g) were computed, and equivalence testing (g = 0.24) was conducted at post-treatment and follow-up using the two one-sided test procedure. Response rate (i.e., ≥ 50% symptom reduction), reliable change, deterioration, and acceptability were analyzed as event rates and relative risk ratios (RR). For studies that did not report response, reliable change, or deterioration, these values were estimated using a validated imputation method. Results: Independent raters determined that all included studies were of adequate quality. At post-treatment, depressive symptoms were statistically equivalent across psychodynamic psychotherapy and cognitive behavioural therapy (k = 9; g = -0.11, pequivalence = .048, pNHST = .212). At follow-up, the longest time point within a year, depressive symptoms were neither statistically equivalent nor statistically different (k = 6; g = -0.16, pequivalence = .184, pNHST = .126). Rates of response rates, reliable improvement, deterioration, and acceptability did not differ significantly across psychodynamic psychotherapy and CBT. Conclusion: Manualized psychodynamic psychotherapy and CBT demonstrate equivalent efficacy at post-treatment for depressive disorders in adults. However, insufficient data exists to determine equivalence at follow-up. There was no evidence that psychodynamic psychotherapy and CBT differ significantly in rates of response, reliable improvement, deterioration, or acceptability. Likewise, the observed differences between psychodynamic psychotherapy and CBT for reducing symptoms of depression are modest. Accordingly, patient preference should guide treatment selection.Arts, Faculty ofPsychology, Department ofGraduat

Analysis of biomass supply chain efficiency and feedstock quality for sustainable small-scale combined heat and power (CHP) systems : a case study at the Alex Fraser Research Forest, British Columbia

Forest biomass utilization in British Columbia (BC) remains in its early stages due to limited incentives to shift from lower-cost local energy sources. This contrasts with substantial biomass waste, averaging 2.9 million m3 per year from 2019 to 2023. A significant portion of this waste contributes to greenhouse gas (GHG) emissions, with slash pile burning (SPB)—a common regional practice—releasing an estimated 2.7 megatons (Mt) of CO₂ equivalent in 2021. To address deteriorating climate change, the provincial government has committed to reducing SPB and facilitating bioeconomy by promoting sustainable biomass use. Located in Wildland-Urban Interface (WUI), the Alex Fraser Research Forest (AFRF) recently installed a small-scale Combined Heat and Power (CHP) plant to convert biomass from fuel treatments into on-site energy (heat and power). This initiative serves as a model for remote communities to harness biomass in the energy transition away from fossil fuels. However, BC lacks comprehensive research on biomass supply chains for small-scale CHP plants. This research addressed this gap by examining the optimal biomass supply chain for AFRF’s CHP plant, focusing on: 1) supply chain cost-efficiency and 2) biomass feedstock quality. The supply chain analysis evaluated configurations for two harvesting methods—non-delimbed and delimbed energy wood harvesting—alongside machinery size and chipping location. Findings indicated that the most cost-effective configuration for non-delimbed harvesting includes conventional feller-buncher and grapple skidder with storage site chipping, while it includes conventional harvester and forwarder with storage site chipping for delimbed energy wood harvesting. The quality analysis assessed woodchips based on moisture content, particle size distribution, bulk density, and ash content. Results showed that one-year naturally dried non-delimbed energy wood is the most suitable biomass source for the CHP plant, supplemented with artificial drying as needed. By integrating the findings, the thesis demonstrated an optimal biomass supply chain for the CHP plant, recommending conventional feller-buncher, conventional grapple skidder, and one-year natural drying at storage site, followed by chipping to produce qualified woodchips for the CHP supply. The biomass cost is around 160 CAD/ODT (delivered to the storage facility), covering felling, primary transportation, and chipping, depending on three different treatment objectives.Forestry, Faculty ofGraduat

Investigating fuzzing strategies in a CI/CD setup

Fuzzing best practices suggest that fuzzing should be run for at least 24 hours, if not longer. This recommendation makes it hard to integrate fuzzing into CI/CD contexts, to rapidly check a commit for bugs. Existing studies on CI/CD fuzzing simulated a CI/CD environment by running undirected fuzzers on Magma benchmark programs, which have multiple bugs injected into a single version of the program. Directed fuzzers, such as AFLGo, aim to generate inputs that reach specific target locations in the program being fuzzed. Thus, they should be more effective at fuzzing in a CI/CD environment. In this study, we evaluate both directed and undirected fuzzers in a simulated CI/CD environment. Like prior work, we use Magma as a source of benchmarks, and run fuzzers for 10 minutes. Unlike prior work, we start the fuzzing process from a saturated corpus, rather than Magma's default corpus. Also unlike prior work, we run the fuzzers on versions of Magma programs with a single bug injected. Since Magma patches give directed fuzzers access to too precise information as to the bug location, we provide experimental designs to deal with this threat by adding additional lines of target code to evaluate the sensitivity of directed fuzzers. We report both preliminary results on a small subset of 50 benchmarks and complete results on all of them.Science, Faculty ofComputer Science, Department ofGraduat

Data-driven mitigation of false data injection cyberattacks in networked control systems

The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat

Navigating sensitivity : an exploration of self-acceptance among highly sensitive men

The concept of the highly sensitive man has received limited academic attention, despite a growing cultural shift toward recognizing diverse expressions of masculinity. This study explores the lived experiences of heterosexual highly sensitive men, examining the factors that have supported or hindered their self-acceptance. Using the Enhanced Critical Incident Technique (ECIT), nine participants were interviewed to identify key incidents that shaped their understanding of sensitivity. The findings reveal a number of categories, including emotional regulation, relationships, masculinity expectations, community, and spirituality. Participants described both supportive and challenging experiences in navigating societal norms that often devalue sensitivity in men. Additionally, this study explores the role of language in shaping perceptions of high sensitivity, highlighting the need for alternative terminology that fosters broader acceptance. By integrating existing literature on masculinity, sensory processing sensitivity, and mental health, this research contributes to a deeper understanding of how highly sensitive men construct their identities and find belonging. The results suggest that increased awareness, education, and social support can enhance self-acceptance for highly sensitive men. Implications for therapy, workplace accommodations, and cultural discourse on masculinity are discussed.Education, Faculty ofEducational and Counselling Psychology, and Special Education (ECPS), Department ofGraduat