Trent University

Microwave resonances in isolated water-based spheres, dimers, and trimers are explored using simulations conducted with COMSOL Multiphysics. The study centers on morphology-dependent resonances (MDRs) and hotspot characteristics in cm-sized objects at microwave frequencies. Monomers subjected to microwave radiation exhibit four distinct resonant modes at specific sizes characterized by electric and magnetic field distributions which correspond to magnetic-dipolar, electric-dipolar, magnetic quadrupolar, and electric quadrupolar resonances, respectively. Dimer configurations reveal intriguing hotspot features, with axial hotspots emerging as a key resonant characteristic. The three fundamental dimer orientations dictate unique resonant behaviors, highlighting the sensitivity of hotspot intensity to orientation changes, but smooth and consistent trends during transitions between them. Investigations into trimer structures, as a more intricate geometry formed by interconnected dimers, reveal the subtle interactions of spheres in a trimer structure. Trimer hotspots largely reflect the sum of isolated dimer hotspot contributions, showcasing the energy conservation with no evidence of a newly formed hotpot. Our results, while arising as a consequence of the particularly high index of refraction of water at GHz frequencies, are generalizable to other length scales (such as nano-photonics), were materials with sufficiently high refractive index and transparency to be found.

Author Keywords: COMSOL simulations, Electromagnetic physics, Microwave frequencies, Morphology-dependent resonance, water-based objects

Acoustic communication is vital for mediating interactions between individuals and their environment. From echolocating bats to isolated rodent pups, ultrasonic vocalizations are a useful mechanism for producing localized and cryptic acoustic signals. Flying squirrels have been demonstrated to produce almost exclusively ultrasonic calls which is rare in both squirrels and mammals, though the significance of this acoustic range is unknown. To investigate the context of ultrasonic calls in these gliding mammals, I created phylogenetic comparative analyses to compare ecological and morphological traits against call frequencies. I found that nocturnality, a trait entangled with gliding in squirrels, was related to higher-frequency calls. Furthermore, by comparing all gliding mammals and their non-gliding counterparts, I found that gliding mammals produce significantly higher frequencies than these relatives. This form of cryptic communication is likely used to avoid predation, which was further supported by behavioural experiments wherein flying squirrels used significantly higher frequencies when predation risk increased. While high frequency communication was used by most gliders, I found that ultraviolet-induced photoluminescence, another potential form of crypsis, was strongly associated with nocturnality, with half of the tested gliding mammals showing evidence of this unique colouration. While ultrasonic vocalizations are widespread in echolocating bats and echonavigating mammals, I did not find evidence to support echonavigation in flying squirrels. Instead, I found that ultrasonic vocalizations are used in a variety of social contexts and during solitary foraging and exploration. These combined results demonstrate the unique ecological and evolutionary pressures acting on small-bodied, nocturnal gliding taxa and the resulting cryptic behaviours and communication.

Author Keywords: communication, flying squirrels, gliding mammals, Sciuridae, ultrasound, ultraviolet-induced photoluminescence

This thesis examines Beyoncé's art within the context of Black feminist thought, specifically focusing on how her work reflects and contributes to the themes of sisterhood, female empowerment, and intersectionality. A comprehensive analysis of her songs and performances will demonstrate how Beyoncé's art advocates for unity, female empowerment, particularly for Black women, and encourages sisterhood and support. The results reveal that Beyoncé's art serves as a powerful tool to challenge societal norms, address racial and gender inequalities, and advocate for justice, especially in the lives of Black women. Through her music and performances, Beyoncé has become a powerful example of using popular music as a medium for social change and cultural empowerment. This research highlights the significance of her contributions to the ongoing conversations surrounding race, gender, and socioeconomic factors, underlining the powerful influence of her art in encouraging a more inclusive society.

Author Keywords: Beyoncé, Black Feminist Thought, Female Empowerment, Gender inequalities, Intersectionality, Sisterhood

This thesis explores the remediation of naphthenic acids (NAs) from oil sands process-affected water (OSPW) using activated carbon (AC) derived from petroleum coke (PC) chemically activated with potassium hydroxide. The research aims to identify the most effective method for the adsorptive removal of NAs by optimizing the use of economically viable KOH quantities and to apply Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) for species-specific detection and characterization of NAs, crucial for targeting specific NAs in future studies.Prior research focused on single-species adsorption, establishing a foundational understanding of non-competitive adsorption before applying these findings to more complex NA mixtures and OSPW. This study builds upon this foundation, addressing a significant gap in the literature concerning the use of petcoke-derived AC with low KOH ratios and short activation times, which are economically advantageous for large scale applications. In this thesis, a comprehensive investigation into the kinetics and isotherms of NA adsorption on various ACs including PAC (petroleum coke AC), PWAC (pore-widened AC), HAC (heat-treated wood-based AC), and CAC (commercial AC) was conducted. The study specifically examines the adsorption behaviors of seven model NAs, reflecting the diverse molecular structures present in real world OSPW. The research also explores the impact of pore widening techniques on the adsorption efficiency of ACs, hypothesizing that increased mesoporosity enhances the adsorption of NA compounds. The findings demonstrate that FT-ICR-MS is an essential tool for precisely characterizing the NA species in OSPW, revealing that pore-widened ACs significantly improve the adsorption of NAFCs. This thesis contributes to the field of environmental remediation by offering new insights into the optimization of AC for NA removal, emphasizing the importance of surface chemistry and mesoporosity in enhancing adsorption efficiency. The study's outcomes have significant implications for the treatment of OSPW, providing a scalable and cost-effective solution to mitigate the environmental impacts of oil sands production.

Author Keywords: activated carbon, FT-ICR-MS, naphthenic acids, oil sands, petroleum coke, process-affected water

The interplay between electron charge, spin, and ferroelectric polarization is under-explored for conducting ferroelectric domain walls (DWs). DWs are interfaces that separate regions (domains) within a material that have different orientations of spontaneous polarization. We investigated the electronic band structure of t2g electrons, confined to 90° charged do main walls (CDWs) in barium titanate (BaTiO3), a prototypical perovskite ferroelectric. A key novel aspect of our study is the explicit inclusion of both orbital and spin degrees of freedom in the Hamiltonian. This leads to an Ising-type spin-orbit coupling (SOC). We constructed a tight-binding (TB) model for t2g electrons that is constrained by symmetries of the DW, including time-reversal, mirror, and rotational symmetries. First-principles density functional theory (DFT) calculations were performed to extract the TB parame ters. Our findings offer new insights into spin-orbit interactions at ferroelectric domain walls and open avenues for their potential use in next-generation electronic and spintronic devices

In this thesis I argue that Sing-Song: A Nursery Rhyme Book (1872) disrupts conventional narratives of the idealized maternal role in the Victorian era, "the angel in the house" by confronting and giving a voice to the often overlooked realities of maternal suffering. Rossetti accomplishes this by fostering the conversation regarding the challenges inherent in motherhood. Sing-Song has been dismissed by critics as inappropriate for its intended child audience. However, such assessments rely on outdated assumptions and fail to recognize the intention behind the poetry collection. The subtle coding of the rhymes for a maternal audience has largely been overlooked. Rossetti deliberately represents the psychological and emotional complexities of motherhood, offering a more realistic portrayal of the mental health challenges that may accompany the maternal experience. In turn, Sing-Song challenges the idealized mother figure of the Victorian era and represents a more nuanced understanding of motherhood.

Keywords: motherhood, idealized, maternal mental health, the angel in the house, infant death

Author Keywords: idealized, infant death, maternal mental health, motherhood, the angel in the house

My research into Et'sehch'i, the Traditional Dene Burial Practices, is a comprehensive study into how smaller groups, clans, of our northern Dene understood and handled matters of funerals. The research focuses on the Dene community of Radelie Koe, Fort Good Hope in the Northwest Territories of Canada, my home community. In these Pre-Contact times, there weren't any of the modern tools we are now familiar with. The dead were interred on outdoor stages, raised platforms.

The most important part of Et'sehch'i involved the matriarch or another Elder of the clan hand-picking individual youths to help keep the Community together. They kept together as a group, going around together, cutting wood for people, hauling water or ice and generally reinstalling joy into the People's lives. Another form of these coming-of-age ceremonials involved young girls becoming women. The research involves the ways in which the Dene handled anything to do with major changes throughout our history. It was mandated by the Elders Council and Band Council of Fort Good Hope and followed a community protocol of respect for culturally sensitive material. These traditions, following ethical standards, account in good part for our survival from a time we call "When the World was New", from dinosaurs to today's computers.

Keywords: Dene Community, Burial Practice, Et'sehch'i, Ceremony, Funeral, Youth, Painting, Ceremonial Practice, Ways of Being

Author Keywords: Burial Practice, Ceremony, Dene Community, Et'sehch'i, Funeral, Painting

This dissertation focuses on the intersectionality between images posted on social media and social rules in the lives of young people. The findings are based on thirty-four qualitative interviews with young social media users where photo-based methodologies were employed. From these interviews, three key themes emerged: 1) Posting and sharing images are connected to identity exploration and formation, 2) Social rules around embodied emotions affect how youth present their emotions in online photographic material, and 3) The conflation of private and public spaces in the digital sphere complicates how social media users interact with images. While the findings presented are clear, this dissertation aims to take a holistic approach to understanding youth digital culture and avoids coming to conclusions that view social media as "good" or "bad" for youth. This tactic allows the findings to acknowledge the complexities of communicative digital spaces and understand the intricacies of social media in the daily lives of young people (boyd, 2014; Tilleczek & Campbell, 2019). This dissertation discusses both challenges youth face on social media when posting and viewing images, as well as how images can be used to defy social norms.

Author Keywords: Affect, Culture, Image, Social Media, Youth

Fungi are a diverse group of organisms that play crucial roles in various ecological processes and have immense economic importance. Understanding the intricate mechanisms underlying fungal growth and development is fundamental to harnessing their potential and exploring their applications in different fields. Signalling molecules, such as hormones, have been identified as key regulators in fungal physiology, orchestrating intricate processes and modulating biological responses to the environment. Phytohormones, commonly associated with plants, have been proposed as potential myco-hormones due to their production in a wide variety of fungi. Metabolomic analyses were performed via LC-MS/MS to investigate the role of phytohormones, specifically cytokinins (CKs) and indole-3-acetic acid (IAA), along with lipids and energetic metabolites such as organic acids during the growth and development of the model fungus Sordaria macrospora. The results revealed a clear switch between CK ribosides and CK free bases during the ascosporegenesis stage, with increased levels of cZ and iP and decreased levels of iPR and cZR. A similar pattern was observed in the mutant strain smgpi1 but demonstrating higher levels of CK free bases and increased fruiting body formation compared to the wild type. These findings provide insights into the regulation of phytohormones especially during fungal fruiting body development. In terms of IAA, the levels increased during the transition to sexual development in all strains, with the per5 mutant, unable to produce lipids via the cytosol, demonstrating a higher concentration than the wild type. The interplay between energetic metabolites and IAA suggests a potential role in the transition to sexual development. Additionally, the dose-dependent effects of exogenous CK application were investigated, showing the potential of low concentrations, from 1 to 10 μM, of CKs in promoting biomass accumulation or sexual development. Furthermore, gene editing in S. macrospora was proposed as a future direction to explore the functions of CKs and other metabolites during fungal development. Overall, this research contributes to our understanding of phytohormone-mediated processes in fungi and opens avenues for future investigations in fungal biology.

Author Keywords: fungi, LC-MS, metabolomics, myco-hormone, phytohormone, sexual development

Mortuary archaeology presents a unique opportunity to compare cultural and biological factors within burial assemblages. This study expands upon the previous bioarchaeological research in the eastern portion of the Southern Maya Lowlands through a comparative mortuary analysis that highlights burial trends between the site of Ka'kabish, Belize, and surrounding settlements. Ka'kabish spans from the Middle Formative through to the Postclassic periods (ca. 800 BC to AD 1500) and signifies a diverse social-strata with burials ranging from a variety of ritual and domestic complexes. Ka'kabish displays a preference for primary interments of non-extended positioning, greater chultun (subterranean chambers) use than displayed regionally, potential ancestor veneration, and demonstrates a transition from public, monumental burials, to private, domestic burials, from the Middle/Late Formative to the Postclassic periods. Inter-site comparisons demonstrate that Ka'kabish's mortuary patterns do not directly fit within a specific regional trend; rather, Ka'kabish displays a wide range of influences from many sites in the surrounding lowlands.

Author Keywords: Belize, Ka'kabish, Lowlands, Maya, Mortuary, Southern