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Molecular Imprinting Polymer-Based Sensing of Neonicotinoids
Get PDFNeonicotinoids are a novel class of insecticides that exhibit environmental persistence and off-target effects on both humans and ecosystems. Therefore, there is a need for sensitive and selective sensors to monitor concentrations of neonicotinoids in environmental water and soil systems. Molecularly imprinted polymer (MIP)-based sensors are an emerging technology with strong potential for reliable, sensitive, and selective detection of neonicotinoids. Moreover, MIPs are versatile and compatible with a wide range of analytical techniques, which can further enhance measurement capabilities in the development of practical and robust sensors. Despite this promise, many routes remain underexplored for neonicotinoid detection. This review reports on the current state of neonicotinoid chemical sensors and detection methods using MIPs and highlights potential applications of MIP-based approaches as cost-effective and easy-to-operate solutions for monitoring neonicotinoids. Recent sensors incorporating MIPs and electrochemical or optical techniques for neonicotinoid detection are described and compared. Approaches employing magnetic solid-phase extraction and quartz crystal microbalance are also discussed. Additionally, the influence of monomer choice for MIP synthesis, as well as the use of additives and nanomaterials for sensor construction and analyte detection, is reviewed. These methods may promote sustainability, reusability, ratiometric or simultaneous detection of neonicotinoids, and sensor portability for on-site monitoring
Women’s History and Community Identity in Rural Saskatchewan: Community Engagement at the Jasper Cultural and Historical Centre
Get PDFThis thesis investigates the representation of women’s history in the Geraldine Moodie Gallery in the Jasper Cultural and Historical Centre in Maple Creek, Saskatchewan, exploring how the Gallery’s community-centric curatorial approaches shape contemporary portrayals of women’s historical identities, achievements, and challenges in southwest Saskatchewan between 1875-1975. By using a flexible thematic approach and conducting semi-structured interviews, this thesis attends to the way in which the Gallery represents the contemporary community’s understanding of women’s history. Results show that the Gallery provides nuanced representations of women’s domestic and professional lives, particularly of rural settler identities. Interview analysis reveals that the museum is aware of tension within the community regarding the need for increased representation of marginalized communities within the museum. This research contributes to museum studies literature by using this case study to highlight the complexities and possibilities of community engagement in diversifying women’s history exhibits in rural community museums.M.M.St
A Single Center Study on Patient Outcomes Following Temporomandibular Joint Replacement Using a Single Patient-Specific TMJ Prosthesis: The Mount Sinai Hospital / University of Toronto Experience
Get PDFAbstractObjectives: Despite growing use of custom alloplastic TMJ prostheses, long-term device survivorship data and
their effect on patient function for specific systems remain limited. This study aims to determine evaluate the
3-year survivorship of a single patient-matched TMJ implant system placed at a single tertiary center, evaluate
functional patient outcomes and identify any patient-related predictors of revision.
Patients and Methods: A retrospective review of custom Zimmer BiometTM total-TMJ replacements
performed at Mount Sinai Hospital (Jan 2004–Dec 2018) by a single operator captured demographics, primary
diagnoses, functional outcomes, and any re-operations or device replacements.
Results: 100 patients (80 women, 20 men; mean age = 43 years, range 16 to 70) underwent custom alloplastic
TMJ reconstruction, receiving a combined total of 174 prostheses (74 bilateral, 26 unilateral), and were
followed a mean of 5.1 ± 2.9 years (median = 3.7, maximum = 15.5). Pre-operative TMJ diagnoses were mainly
osteoarthritis (79 %), ankylosis (29 %), inflammatory arthritides (10 %), and benign neoplasms (9 %), with
trauma, revision, or developmental deformity accounting for the remainder (8 %). Almost half (47.5 %) had
prior open-joint surgery, and 67 % underwent simultaneous orthognathic or other reconstructive procedures
at time implantation. Mouth opening (in millimeters) and pain levels (Numeric Rating Scale, NRS 0-10)
significantly improved (p < 0.001) from baseline to both 1-year and 5-years postoperatively and remained
stable between during that period.
Conclusions: The 3-year survivorship of a single patient-matched TMJ implant system was 96%, which aligns
with previously reported rates for other contemporary devices (94 to 96 %). accompanied by lasting pain relief
and functional gains. A failure rate of 4 % was observed due to heterotopic bone formation, infection,
malocclusion, or dislocation, which reflects patterns observed in other studies. No patient- or surgery-level
predictors emerged, likely due to the few events reported. The limited follow-up period of 3 years and
absence of stock-implant controls reflects only early implant performance, while limiting implant
generalizability and ability to draw any implant-specific conclusions. Future multi-centre, large-scale studies
with long-term surveillance, i.e. ≥10-year, should focus on stratifying outcomes by primary TMJ diagnosis,
patient comorbidities, and prior surgery, to further assist in developing validated risk-assessment tools, and
evaluate modifiable factors, such as patient selection, surgical planning, and post-operative rehabilitation to
further reduce failure rate and optimize functional recovery.M.Sc
Charge-Based Control Techniques for Multiphase DC-DC LLC Resonant Converters
Get PDFThe growing adoption of electric vehicles (EVs) and the rising power demands of AI-driven data centers impose stringent requirements on power electronics infrastructure. The LLC resonant converter is a leading candidate for compact, high-efficiency isolated dc-dc conversion in these applications, yet single-phase implementations suffer from high current ripple, while multi-phase systems require complex synchronization and face degraded transient response. This thesis investigates charge-based hysteretic control as a pathway to simplify implementation while enhancing performance in multi-phase architectures. Two novel strategies are proposed and experimentally validated: (1) a distributed, sensorless synchronization method for parallel-input parallel-output (PIPO) configurations that achieves quasi-synchronized operation and reduces output-current deviation by 72\% under more than 20\% component mismatch, and (2) a Gray-code-based hysteretic control for star-connected topologies enabling natural interleaving, soft-switching, and fast transient recovery. Both approaches are validated on a 3 kW, 400 V prototype, demonstrating improved scalability, reduced settling times, and robust performance.M.A.S
Cooperative Positioning with the Aid of Reconfigurable Intelligent Surface
Get PDFThis thesis investigates the integration of reconfigurable intelligent surfaces (RISs) with cooperative positioning (CP) techniques to enhance localization accuracy and enable robust positioning in challenging wireless environments. The research addresses scenarios both with and without access points (APs), presenting novel frameworks and algorithms. Initially, the work establishes foundational channel models for RIS-aided Device-to-Device (D2D) communications in two-dimensional and three-dimensional settings. For AP-present scenarios, a key contribution is an innovative uplink CP framework featuring a resource-efficient model that allows simultaneous multi-user pilot transmissions on orthogonal subcarriers, thereby reducing overhead. This includes a joint optimization of user equipment (UE) scheduling, power allocation, and RIS phase shifts, solved iteratively via block coordinate descent (BCD), to minimize the Cramér-Rao lower bound (CRLB). A two-stage localization algorithm, combining a one-dimensional (1D) search with multidimensional scaling (MDS) for refinement using D2D channel parameters, demonstrates significant performance gains, achieving a 65% improvement over non-cooperative methods.
Subsequently, the thesis pioneers AP-free CP, demonstrating its feasibility using only a single RIS and D2D communications, provided a minimum of three half-duplex UEs cooperate. This approach contrasts with prior works, which often require full-duplex UEs or multiple RISs. Practical RIS phase shift designs, including directional codebooks based on estimated spatial frequencies rather than absolute angles, alongside an optimized power allocation strategy, are proposed for this AP-free context. An AP-free localization algorithm, employing a 1D coarse search followed by maximum likelihood estimation (MLE) for refinement, achieves sub-meter accuracy even under multi-path conditions. Finally, the AP-free paradigm is extended to tracking multiple moving UEs using multiple RISs as anchors, where an extended Kalman filter (EKF) maintains high tracking accuracy in the sub-meter range. Overall, this thesis underscores the significant potential of integrating RIS technology with D2D communications to revolutionize wireless positioning systems for 6G and beyond.Ph.D
Boosting Stability and Cycling Life of Li (Ni 0.5 Mn 0.3 Co 0.2) O2 Via Mitigation of Cation Mixing Using La-B Co – Doping
Get PDFNickel-rich layered oxides such as Li(Ni₀.₅Mn₀.₃Co₀.₂)O₂ (NMC532) are promising cathode materials for lithium-ion batteries owing to their high specific capacity and balanced transition-metal composition. However, their practical application is hindered by cation disorder, oxygen depletion, and structural degradation during cycling. This thesis investigates La–B co-doping as a strategy to mitigate these challenges and enhance the stability of NMC532. X-ray diffraction results revealed that La–B incorporation increased the I003/I104 ratio from 1.04 in pristine NMC532 to 1.40 in optimally doped samples, indicating reduced Li/Ni antisite defects and improved lattice ordering. Electrochemical analysis showed that 0.5 wt% La–B doping achieved superior cycling stability, retaining 91.2% of its initial capacity (197.5 mAh g⁻¹) after 250 cycles, outperforming pristine NMC532 and comparable reports. As a complementary approach, V₂O₅ coating was also explored, demonstrating enhanced surface ordering. Overall, La–B co-doping effectively improves structural integrity and long-term electrochemical performance in NMC532.M.A.S
Philippine Heritage Languages in Canada: Kuwentuhan from Children of Immigrants
Get PDFIn Canada’s multicultural yet officially bilingual context, immigrant communities like the Filipinx/a/o diaspora experience a sharp decrease in heritage language (HL) transmission. This study investigates the tensions of Philippine heritage language (PHL) policies, shaped by colonial history and reinforced in Western society. Taking the perspective of the learner, thirty interviews were conducted with adult children of immigrants from Vancouver and Toronto, two metropolitan areas with significant Filipinx/a/o populations. Incorporating a method of kuwentuhan, a culturally-specific storytelling practice, enabled participants to share their lived experiences and find connections between them. The findings suggest that the Philippines’ official policies of English and Tagalog directly impact PHL learning at the family, community, and personal levels, yet reported strategies of self-initiated learning indicate strong motivations to expand on their linguistic repertoires. This study provides theoretical contributions to HL scholarship and practical insights for fostering inclusive and needs-based HL education in settler colonial contexts.M.A
Engineering Sustainable Composites for Lightweight Automotive Applications: Experimental and Theoretical Insights on Hybrid Fibre-reinforced Polymers
Get PDFThis study investigates the enhancement of mechanical properties in cellulose microfibre/carbon fibre hybrid composites on PA11-based matrices, aiming to achieve lightweight and sustainable applications in the automotive sector. The use of a PA11-PP blend matrix led to composites with improved thermo-mechanical performance, elevated heat deflection temperatures, and reduced densities, key attributes for semi-structural automotive components where both weight reduction and mechanical reliability are critical.To support and interpret the experimental findings, a progressive modelling strategy was employed, combining semi-empirical and analytical methods. Classical models such as HROM, Halpin–Tsai, and shear-lag theory were adapted and mathematically refined to predict the tensile modulus of the composites. Using the effective matrix approach, the modified Halpin–Tsai model accurately captured the behaviour of randomly oriented fibres, with best-fit orientation factors (λL = 0.481, λT = 0.736) aligning closely with theoretical values (0.375 and 0.625), confirming its applicability for reinforcement efficiency in hybrid composites.
To obtain further insight into stress transfer mechanisms and fibre-length-dependent behaviour, particularly relevant in short-fibre composites, the study advanced toward the shear-lag model. Unlike the Halpin-Tsai formulation, which is primarily geometry-based, the shear-lag approach provides a mechanistic description of load transfer between fibres and matrix. The classical shear-lag model was refined through the introduction of a stress transfer efficiency factor (α), defined as a non-linear function of the ratio of fibre length to its critical length. This analytically modified formulation enabled more realistic and accurate predictions of the tensile modulus in composites reinforced with microfibrillated cellulose and short carbon fibres.
The combined use of semi-empirical and analytically modified models, supported by an effective matrix approach, enabled a deeper understanding of the reinforcing mechanisms in hybrid fibre systems. This framework validates experimental observations and offers a versatile design tool for optimizing the performance of bio-based hybrid composites across a wide range of applications.Ph.D
Dense Forests with Low Visibility
Get PDFA dense forest in Rd is a set of points with finite density such that any line segment of length V(ε), the visibility function of the forest, comes within distance ε of an element of the set. The points with a ball of radius ε centred at them can be viewed as trees obstructing visibility, hence the name. Such sets are known to exist. The problem now is to determine how small the visibility can be made and how many additional properties can be required from a dense forest. This thesis presents results in those directions. In this thesis, a dense forest is constructed by modifying a base set obtained from a Poisson point process by adding points to it such that the visibility is in O(ε−(d−1) ln ε−1). The constant implied by the big-O notation depends on dimension only. Further, the Poisson point process can first be adjusted so that the base set is uniformly discrete while maintaining the same final visibility. Due to the latter addition of points, the resulting dense forest is still not uniformly discrete.
Through a change of perspective—from eliminating lines of sight to eliminating empty regions—the problem of finding dense forests is closely related to Danzer’s problem. The problem asks if there exists a set of finite density intersecting every convex set of volume 1. The methods used to find dense forests in this thesis do not rely on the specific shape of the empty regions being examined. As a consequence, they are well suited to approach Danzer’s problem. A relaxation of Danzer’s problem is examined where the volume of the convex sets is allowed to grow as their eccentricity increases. Bounds on the growth of the volume are obtained by adapting the approach taken for dense forests.Ph.D
Exploring Copyright: A case study in practical copyright education for college educators
Get PDFAn accelerated transition from in-person to online learning at Centennial College, an art and applied technology college in Toronto, Ontario, was catalyzed by the pandemic starting in early 2020. This change led to a significant rise in copyright inquiries to the library's copyright office, highlighting an immediate need for enhanced copyright education and support for effective application of copyright knowledge in online teaching environments.
In response to this need, the Exploring Copyright series was created by the library's copyright librarian. This outer-space themed series consisted of eight copyright “missions” tailored for faculty and staff involved in online teaching and course development. The series was presented online in sessions delivered every other week over the course of a semester. The material was subsequently compiled into a course environment with asynchronous modules and resources.
This paper will explore the evidence-based development, initial delivery, and evaluation of the Exploring Copyright series. It will examine how this initiative complemented the existing copyright literacy programs at Centennial College, addressing the evolving needs of the academic community.
Copyright education and outreach professionals in higher education may find this approach particularly useful. The Exploring Copyright series offered a flexible, community-driven model for adapting copyright education to suit a rapidly changing online environment