NOVEL APPROACHES TO FAST OCV CHARACTERIZATION AND IMPROVED CAPACITY ESTIMATION IN LITHIUM ION BATTERIES

This thesis considers the problem of open circuit voltage (OCV) to state of charge (SOC) characterization in li-ion batteries for battery reuse applications. The traditional approach to OCV-SOC characterization is done by collecting voltage and current data through a slow discharge and charge process; this process usually takes about 60 hours. Such OCV-SOC characterization is performed on a few sample batteries because the OCV-SOC characterization is considered to be the same for new batteries coming out of the same manufacturing process. However, the characteristics of a battery may change as it is used for years in different environmental and usage conditions. Hence, they may need to be re-characterized before secondary use. Unlike primary characterization, the secondary characterization may have to be done faster in order to save time and cost. This thesis presents a faster approach for OCV-SOC characterization. The proposed approach in this thesis consists of constant-current profiles that halves in magnitude after a specified time. Such reductions allows us to fully deplete the battery; similarly, the battery is charged back with a reducing current profile in order to make sure the battery is fully charged. The resulting current profile reduces the total characterization time by 1/5. Secondly, we explore the idea of discharge and charge capacity of batteries. A traditional low-rate-OCV test consists of constant-current charging which results in a voltage drop based on the internal resistance and charging/discharging current. This thesis presents an approach to counteract this voltage drop, by appropriately over-charging and over-discharging the battery to obtain the most accurate representation of the capacity of the battery

An SOA-Based Approach of Adaptive E-Tutoring Systems

The educational technology landscape continually evolves, and e-tutoring systems are pivotal in modern pedagogy. Traditional e-tutoring methods often need help with adaptability and user-friendliness across various devices and platforms. To address these challenges, this research introduces a novel approach that leverages service-oriented architecture (SOA) principles, enhancing scalability and flexibility. The SOA configuration streamlines communication between system components, optimizing question delivery and response evaluation. Additionally, the research contributes adaptive interfaces that intelligently engage users based on their device configurations and preferences, offering facial, vocal, or textual interactions. These interfaces ensure a consistent and tailored learning experience across PCs, laptops, and mobile devices. The study also considers critical success factors like User-Friendly Design and Technical Competence. This research presents a comprehensive solution to enhance e-tutoring systems for modern, adaptive, and engaging learning environments

Non-Hermitian physics achieved via non-local Gilbert damping

In this thesis, we study a simple model for a ferromagnet starting with Heisenberg exchange interaction including the effects of dissipation. Gilbert damping is consid- ered and generalized from an on-site term to include non-local damping interactions between neighbouring spins. The strength of the damping interaction between neigh- bours can be tuned individually to provide the freedom to change the parameters of the system and explore the range of possible non-Hermitian behaviours. We consider the example of a honeycomb lattice ferromagnet featuring Dirac cones and two sub- lattices and analyse the resulting spectra and eigenstates. Under periodic boundary conditions, we find the Dirac magnons that are present in the Hermitian case are split into pairs of exceptional points connected by nodal lines. Open boundary condi- tions are then studied, including cases with a periodic boundary along one direction and an open boundary along the other, to explore the presence of the non-Hermitian skin effect in this model. We find the spectra under open boundary conditions differ substantially from that of periodic boundary conditions and the eigenstates are often localized on the boundary. Lastly, we discuss open questions and future directions for exploring non-Hermitian physics in magnetic systems

The Role of Nonprofit Organizations in the Context of Increased Living Costs in Ontario

This research highlights the crucial role of non-profit organization in supporting the well-being of local communities in Ontario, particularly amidst increased cost of living. The increased cost of living has led to a higher CPI, negatively impacting the quality of life for many Ontarians and Canadians. While the vulnerable population become increasingly uncertain about the future, the role of non-profit organizations becomes prominent as effective community leaders. This research will illustrate how non-profit organizations address the most significant challenges the vulnerable population face today in terms of their quality of life, which are: housing insecurity, food insecurity, and transportation. The research methodology section will illustrate a case study of a local non-profit organization within the Windsor-Essex region in Ontario. The results indicate a growing demand and reliance on non-profit organizations of their services

Toxoplasma gondii: Comparing Vesicles from Healthy and Infected CellsÂ

Toxoplasma gondii is a protozoan parasite with a successfully high infection rate in humans. T. gondii infection can cause a clinical illness called toxoplasmosis when a person ingests contaminated food and water or from mother to fetus during pregnancy as it can cross the placenta. Approximately 1/3rd of the current general population is infected with toxoplasmosis. Typically, toxoplasmosis presents as asymptomatic and dormant in immunocompetent individuals. However, for immunocompromised individuals, toxoplasmosis can present as a serious disease that can lead to various negative effects such as infertility, blindness, encephalitis, acute respiratory failure, and occasionally, death. There is no vaccine for toxoplasmosis, although recent studies show that small extracellular vesicles (EVs) relate to disease protection and the induction of an immune response. T. gondii changes the content of vesicles within cells that it infects, which in turn changes the way cell-to-cell communication occurs between non-infected and infected cells. To test this hypothesis, human foreskin fibroblast (HFF) cells will be cultured in D10 media until fully confluent. Afterwards, using osmotic vesiculation, the EVs of both non-infected and infected cells are excreted and isolated through centrifugation. Then, the EVs go through a Bligh and Dyer procedure to separate proteins embedded on the plasma membrane surface to allow better lipid characterization. Once the proteins are separated, the EVs undergo staining with fluorescent dyes which bind onto different lipid phase regions thus allowing us to characterize the lipid content. Comparison of the vesicle content that is derived from both non-infected cells and infected cells will help identify significant differences which will help current researchers gain a more thorough understanding of how toxoplasmosis affects cell-to-cell communication

Biocompatible self-immolative polymers: Towards traceless medical devices

Stimuli-responsive self-immolative polymers have become a popular area of study in chemistry recently, as they can be used in drug delivery, sensory materials, plastics, and more. Self-immolative polymers are unstable polymers that spontaneously depolymerize from head to tail into smaller molecules. These polymers can be stabilized by attaching an end-cap and will remain stable until the endcap is removed by an external stimulus such as pH, light, heat, enzymes, or redox potential. Once the end-cap is removed these polymers will undergo a fast decomposition. These polymers can be used in drug encapsulation, delivery, and release in cancer treatments, with the hydrophobic toxic materials encapsulated in the membrane and hydrophilic materials in the core of a vesicle. This project aims to develop self-immolative polymers with end-caps, to create non-toxic amphiphilic block copolymers based on biomolecules for various applications, especially peptide and drug delivery. In this project, amino acids are used as the base for the self-immolative polymers to use in the preparation of amphiphilic block copolymers, where both the hydrophobic and hydrophilic polymers will be self-immolative polymers that can self-assemble in aqueous solutions to form nanoparticles. On each residue, there is a free amine that has the potential to become a fluorescent tag, a biological ligand, or a cross-linkable moiety to a pharmacophore to create a prodrug. This project is focussing on using these biocompatible self-immolative polymers to create traceless medical devices

Relative age affects among hockey draftees: An analysis of the Ontario Hockey League Priority Selection and Under-18 drafts.

Athletes born in the months immediately after a cut-off date often benefit from selection advantages known as relative age effects (RAEs; Barnsley et al., 1985). The purpose of this study was to compare birth distributions of athletes selected in the Ontario Hockey League (OHL) Priority Selection and U18 drafts against the larger populations from which they were derived. We sought to determine if the addition of the U18 draft in 2017, which gives players an extra year to develop, would reduce RAEs. Birthdate information for athletes drafted from 2017 through 2020 were retrieved from ontariohockeyleague.com. Chi-square goodness of fit tests were used to compare the birth distributions of athletes from both drafts to what would be expected based upon Canadian population birth rates and Ontario Hockey Federation (OHF) birth rates for ‘Midget’ players. A supplementary analysis was performed to identify differences between the Priority Selection and U18 drafts. Our results showed a significant overrepresentation in the number of players born in the first quartile of the year in both the Priority Selection and U18 drafts compared to Canadian birth rates, providing evidence of RAEs. Similarly, RAEs were found among players in the Priority Selection draft when compared against OHF birthrates, but not for players in the U18 draft. Finally, the birth distribution of players in the Priority Selection were significantly different from those in the U18 draft, with the RAE trend being less pronounced among U18 players. Our findings suggest RAEs remain a prominent issue in the OHL

Spy 1: A Potential Driving Force of the Breast Cancer Stem Cell Population

Breast cancer is the most commonly diagnosed cancer in women. Despite recent improvements in diagnostics and treatment options, the tremendous heterogeneity of the disease often complicates treatment. Triple Negative Breast Cancer (TNBC) occurs in 10-15% of breast cancer diagnoses and typically has poorer outcomes. This is largely due to lack of targeted therapies and the existence of a population of cells known as breast cancer stem cells (BCSCs); a population known to be high in TNBC. BCSCs are more resistant to therapy and capable of driving patient relapse. Cell cycle mediators may play a key role in driving expansion of this population of dangerous cells. Spy1, a cyclin-like protein, promotes cell cycle progression through the G1/S, and the G2/M phase of the cell cycle and has been shown to be elevated in TNBC patients. Additionally, Spy1 is known to expand the brain tumour initiating cell population in brain cancers. Using an in vitromodel of TNBC (MDA-MB-231 cell line), the relative abundancy of the BCSC population can be assessed to determine if increased levels of Spy1 can expand the BCSC population resulting in more aggressive, invasive and resistant cancers. BCSCs can be identified using markers known to label this population such as the CD44 high/CD24 low, and ALDH isoforms. This work seeks to determine if Spy1 is capable of regulating the BCSC population and may allow for the development of targeted therapy to increase the survival rate of those diagnosed with TNBC