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Design and development of a variable frequency drive test bench prototype and testing regime for repaired drives
Get PDFSmall and medium-sized industrial control panel makers, systems integrators, and repair shops frequently encounter issues with Variable Frequency Drive (VFD) testing. These companies frequently rely on third parties to evaluate their VFDs prior to field commissioning, increasing expenses. To address this issue, an in-house test bench was created for a control systems integrator's maintenance department (KJ Controls). The test technique includes static, functional, and operational testing of the drive under test. To completely verify the VFD's operational capability, it must be connected to a loaded motor. A load motor/dynamometer is required for this test. For this, a prototype was created in the repair department using readily available and stock components. This configuration facilitated the testing of the operation and functioning of a 2 HP drive. The tests run on the drive included a static test, a free run test, a motor stall test, and a speed regulation test. These were then suitably recorded on a factory acceptance test sheet. It was eventually calculated that having an in-house testing system would save the company at least 10% on the total cost of testing repaired VFDs. It was predicted that the payback period for such a test bench arrangement would be close to three years.Graduat
What’s more notable: Typing or handwriting? An exploration of student preference on cognitive load in note-taking strategies
Get PDFThe present study investigated the impact of student preference for notetaking methods (handwriting or typing) on notetaking performance due to cognitive demand. Participants (N=12) were undergraduate students enrolled at a university in Western Canada. Using two TED Talk lectures, notetaking performance was assessed by analyzing the quality of taken notes and recall ability. Cognitive demand was measured by assessing working memory through a digit span task. To address the research questions, a series of Mann-Whitney U tests and profiling of descriptive data was performed. Results indicated that notetaking preference had little impact on notetaking performance or working memory. These findings suggest that choosing notetaking methods according to preference may not necessarily result in better performance. Rather it is possible that factors such as individual cognitive ability or contextual demands would be more important to consider. Future research is needed to further explore the complex relationship between student preference, individual cognitive ability and notetaking tasks to better inform educational practices.Graduat
Microdroplets for drug discovery and delivery targeting neural models
No full textThis dissertation explores the application of microdroplet technology in two pivotal areas of the pharmaceutical and biotechnological fields: drug discovery and drug delivery, with a focus on neural models. It presents a comprehensive study on the development and application of microfluidic devices for the fabrication of drug delivery particles and the modeling of cell membranes using Droplet Interface Bilayers (DIBs).
The first part of this work, detailed in Chapters 2 and 3, describes the design and optimization of a Polydimethylsiloxane (PDMS) microfluidic platform for generating oil-in-water droplets. These droplets serve as precursors for polycaprolactone (PCL) microparticles, which have potential for controlled drug release. This platform showcases significant improvements in droplet generation and encapsulation efficiency compared to traditional batch processes and has been adopted for commercial-scale production.
In the second part, Chapters 4 and 5 focus on the application of DIBs as a model for cell membranes. The research quantitatively analyzes the passive diffusion of memantine, an Alzheimer’s disease treating drug, and niacin, a common vitamin supplement used as a neuroprotective agent, and examines the impact of lipid formulation and droplet content on drug absorption and water transport. The findings highlight the advantages of using biomimetic lipid formulations for in vitro studies.
This dissertation demonstrates the significant potential of microdroplet technology in enhancing the efficacy and precision of drug delivery systems and in providing more accurate models for cell membrane studies. The insights gained not only contribute to the academic understanding of drug interaction with cellular membranes but also pave the way for future innovations in neuropharmacology and biotechnology.Graduate2026-01-1
Erosion of stumble correction evoked with superficial peroneal nerve stimulation in older adults during walking
Get PDFIn healthy young adults, electrical stimulation of the superficial peroneal cutaneous nerve (SPn) innervating the dorsum of the foot has been shown to elicit functionally relevant reflexes during walking that are similar to those evoked by mechanical perturbation to the dorsum of the foot during walking and are referred to as stumble corrective (obstacle avoidance) responses. Though age-related differences in reflexes induced by mechanical perturbation have been studied, toe clearance has not been measured. Further, age-related differences in reflexes evoked by electrical stimulation of SPn have yet to be determined. Thus, the purpose of this study was to characterize age-related differences between healthy young adults and older adults with no history of falls in stumble correction responses evoked by electrical stimulation of the SPn at the ankle during walking. Toe clearance relative to the walking surface along with joint displacement and angular velocity at the ankle and knee and EMG of the tibialis anterior, medial gastrocnemius, biceps femoris and vastus lateralis were measured. The combined background and reflex toe clearance was reduced in the older adults compared with the young in mid-early swing (p = 0.011). These age-related differences likely increase fall risk in the older adult cohort. Further, age-related changes were seen in joint kinematics and EMG in older adults compared with the young such as decreased amplitude of the plantarflexion reflex in early swing in older adults (p < 0.05). These altered reflexes reflect the degradation of the stumble corrective response in older adults.FacultyReviewe
The Social Organization of People’s Experiences Enhancing Health for their Young Children after Declining Vaccines
Get PDFIn this publication-based dissertation, I describe a Ph.D. research project with three manuscripts that seek to form a better understanding about people’s activities to enhance their family’s health after declining routine childhood vaccinations. My experiences as a registered nurse working with people who choose not to vaccinate their children ignited my interest in this topic. After not fully vaccinating, people have described contributing substantial amounts of time, effort, and financial resources towards activities that aimed to thwart vaccine preventable diseases in their families and enhance their children’s health. Declining vaccines was not just a choice, or a perspective confined inside of people’s minds. Their efforts to do “health work” for their family can be observed in different families and communities, at different times. Recognizing that what people do is as intensive as it is invisible has led me to engage in a dissertation that seeks to form awareness about this facet of vaccine refusal.
Using Institutional Ethnography, my dissertation research began illuminating how institutions within ruling relations influence the social organization of people’s experiences of health work that aims to enhance the health in their children while protecting their rights to choose which health treatments their children will receive. In this work, a JBI qualitative systematic review, a key informant interview, and a meta-ethnographic exploratory synthesis provided rich descriptions of informant’s health work for their children. My goal was to produce an understanding that assists people and healthcare providers, like nurses, to recognize potential influencing factors of vaccine hesitancy that may have gone unnoticed. From this understanding, I hope that healthcare providers and researchers recognize that respect for people’s “health work” can exist in tandem with a difference in opinion on the topic of vaccines.Graduate2025-04-1
History and North American borderlands: Insights and approaches
Get PDFBIG_Books series, #3Borders are historically contingent and evolve through processes of bordering. Their meanings are constantly changing along with political, economic, and social developments taking place both externally between and internally within states. Like borders, borderlands must also be situated in their temporal and geographical contexts in order to investigate the relations between territory, identity, and sovereignty. The chapters in this collection present selective historical interpretations of borders and borderlands that focus primarily on North American borderlands, emphasizing flows, sovereignty, and indigeneity, three key themes of the Borders in Globalization program.Social Sciences and Humanities Research Council of Canada (SSHRC) Partnership Grant (Grant no. 895-2012-1022)
Erasumus+ progamme of the European UnionFacult
From nature to design: Tailoring pure mycelial materials for the needs of tomorrow
Get PDFModern efforts to influence materials science with principles of biology have allowed fungal mycelial materials to take a foothold and develop novel solutions for the circular bioeconomy of tomorrow. However, recent studies have shown that the value of tomorrow’s green materials is not determined simply by their environmental viability, but rather by their ability to make the polluting materials of today obsolete. With an inherently strong structure of chitin and ?-glucan, the ever-adaptable mycelia of fungi can compete at the highest levels with a litany of materials from leather to polyurethane foam to paper to wood. There are significant efforts to optimize pure mycelial materials (PMMs) through the entire process of species and strain selection, mycelial growth, and fabrication. Indeed, the promising investigations of novel species demonstrate how the diversity of fungi can be leveraged to create uniquely specialized materials. This review aims to highlight PMMs’ current trajectory, evaluate the successes in technology, and explore how these new materials can help shape a better tomorrow.This research was supported by the Global Science Initiative of McMaster University (GSI2020-03).FacultyReviewe
Long-term successional subculture dynamics and their effects on the proliferation efficiency, embryogenic potential, and genetic stability of embryogenic tissues in Larix principis-rupprechtii Mayr
Get PDFLarix principis-rupprechtii Mayr, a coniferous species indigenous to Northern China, possesses significant ecological and economic value. Somatic embryogenesis offers a pathway with significant potential for large-scale propagation, long-term germplasm conservation, and genetic transformation in L. principis-rupprechtii Mayr. However, it remains unclear whether significant variations occur in embryogenic tissues during long-term successive subculturing, which could impact the productivity of somatic embryos. This is a pivotal concern that lacks comprehensive understanding. In this study, three embryogenic cell lines were used to explore the dynamics and relationships among proliferation rate, pre-treatment proliferation rate, and embryogenic capabilities across a series of 32 subculturing cycles. Proliferation rate, pre-treatment proliferation rate, and somatic embryo maturation rate showed no significant correlation with subculturing cycles. However, there was a positive correlation between subculturing cycles and pre-treatment proliferation rate and a negative correlation with somatic embryo maturation rate in the BFU1 cell line. In addition, we utilized ten SSR molecular markers to investigate the genetic stability in embryogenic tissues during long-term subculturing. No genomic variations were detected in any of the three embryogenic cell lines, which suggests that the observed phenotypic dynamics during subculturing may not be primarily driven by genomic alterations. This study provides novel insights into the dynamics of the long-term culture of embryogenic tissues, laying a foundation for the optimization and application of somatic embryogenesis techniques in L. principis-rupprechtii Mayr and potentially other coniferous species.This work was supported by the National Natural Science Foundation of China (No. 32371834), the National Natural Science Foundation of China (No. 32271836), Key R&D Program of Heibei Province, China (20326333D).FacultyReviewe
New goodness-of-fit tests for the Kumaraswamy distribution
Get PDFThe two-parameter distribution known as the Kumaraswamy distribution is a very flexible alternative to the beta distribution with the same (0,1) support. Originally proposed in the field of hydrology, it has subsequently received a good deal of positive attention in both the theoretical and applied statistics literatures. Interestingly, the problem of testing formally for the appropriateness of the Kumaraswamy distribution appears to have received little or no attention to date. To fill this gap, in this paper, we apply a “biased transformation” methodology to several standard goodness-of-fit tests based on the empirical distribution function. A simulation study reveals that these (modified) tests perform well in the context of the Kumaraswamy distribution, in terms of both their low size distortion and respectable power. In particular, the “biased transformation” Anderson–Darling test dominates the other tests that are considered.FacultyReviewe
Deformation of Tian Shan from coseismic to million-year timescales
No full textIntracontinental deformation is often driven by tectonic forces associated with distant plate collisions. The late Cenozoic deformation of Tian Shan is accommodated by both thrust faults bounded the mountain range and strike-slip motion within the mountain. Earthquake hazards and deformation mechanics in the far-field active regions of the Tian Shan are generally poorly quantified due to slow strain accumulation, poor data coverage, and incomplete historical earthquake records. This dissertation aims to gain a better understanding of the kinematics of deformation in this far-field intracontinental mountain belt.
I use multidisciplinary techniques to investigate the late Cenozoic deformation of the Tian Shan across different time scales ranging from coseismic to postseismic and interseismic to million-year scales. I start with an earthquake that occurred in the Kepingtag fold-and-thrust belt in southwestern Tian Shan, a seismically active region and a clear example of basinward migration of deformation. I use Interferometric Synthetic Aperture Radar to measure coseismic deformation, combined with teleseismic waveform modelling and calibrated relocation of the mainshock. The results reveal a fault plane situated on the d\'{e}collement at the base of the folded sedimentary cover and a prevalence of seismicity at basement depths throughout the Kepingtag belt and its foreland, indicating rheological controls on earthquake depths. Then, I apply both coseismic modelling and postseismic time series analysis to study another earthquake that happened along the northern Chinese Tian Shan front, adjacent to the Southern Junggar Fold-and-thrust Belt. The findings indicate that the coseismic rupture on a shallow dipping fault plane triggers postseismic deformation that is farther north beneath the anticline. In the third part of this dissertation, I use low-temperature thermochronology, including apatite fission track and apatite U-Th/He dating systems, to model the thermal history of samples collected from the previously overlooked region in the northern Tian Shan. Inverse modelling of over 1000 published and new thermochronological data from the Tian Shan, Pamir, and northeastern Tibetan Plateau, suggests accelerated exhumation during 15--10~Ma, which represents an acceleration of strike-slip motion.
The dissertation concludes by integrating results across various timescales to discuss deformation styles throughout the region's tectonic evolution. This study also demonstrates that integrating techniques across multiple timescales effectively quantifies the evolution of active faulting and deformation in the Tian Shan.Graduat