QSpace: Queen's Scholarship & Digital Collections

QSpace is an open access repository for scholarship and research produced at Queen's University. QSpace offers faculty, students, staff, and researchers a free and secure home to preserve and present their scholarship.

Recent Submissions

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    Laboratory Investigation of Bubble-Facilitated Contaminant Transport from Aquatic Sediments
    (2024-05-17) McKinstry, Aidan; Civil Engineering; Mumford, Kevin; Mulligan, Ryan
    In waterbodies with contaminated sediments, there is significant potential for gas bubbles released from those sediments (ebullition) to mobilize and transport buried and otherwise inaccessible contaminants out of the sediments and into the water column. The goal of this research is to conduct a set of laboratory experiments to investigate three different mechanisms of bubble-facilitated mass transport: air lift, sorption, and coating. This is accomplished by designing an apparatus consisting of a clear, acrylic vertical column, with gas injected at the base of the column, and placing a sand bed that is overlain by fresh water to represent a natural waterbody. The sand layer properties are varied in terms of the grain sizes and the layer heights, and the emplaced sands are contaminated with fluorescein or sodium dodecylbenzene sulfonate (SDBS) to evaluate the mass transport due to air lift and sorption. Coating is evaluated using a sample of fluid tailings (FT) from an end pit lake associated with the Alberta oil sands, and a bitumen trap is developed to estimate the mass of bitumen transported to the water surface. The results of these experiments indicate that the grain size of the sediments controls the bubble release characteristics, which in turn influence the transport rates of the contaminants. This is seen with larger sediments producing smaller bubbles and higher transport rates. The depth of the sand pack does not have a significant impact on the mass transport rates over the duration of the tests. Air lift and sorption increase the rates of mass transport of fluorescein and SDBS in all tests conducted. Coating demonstrates the highest rates of mass transport of all three mechanisms investigated, suggesting that it may be the dominant mechanism. Overall, these experiments demonstrate that bubble-facilitated mass transport has the potential to mobilize and transport significant contaminant mass out of aquatic sediments, into the overlying water column, and to the atmosphere. These vertical column results provide a detailed baseline for understanding factors that influence three mechanisms for contaminant transport, and further investigation is required to better understand bubble-facilitated mass transport in natural systems.
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    Field assessment of Vincetoxicum rossicum secondary metabolites and their effects on species richness and V. rossicum invasion
    (2024-05-17) Le, Andrew; Biology; Colautti, Robert
    Vincetoxicum rossicum is an invasive vine in North America that impacts native biodiversity and ecosystem services. One of the leading hypotheses to explain the rapid proliferation of V. rossicum is its ability to produce phytotoxic chemicals that directly inhibit the growth of native plants or act indirectly by altering soil fungal communities. Although (-)-antofine, septicine, and tylophorine have been shown to exhibit antifungal properties in vitro, it is unclear whether these chemicals are biologically active and ecologically relevant under natural field conditions. In this thesis, I test the ecological relevance of (-)-antofine and other phytochemicals using field survey data from the Rouge National Urban Park, Canada. First, I test the hypothesis that plots with higher densities of V. rossicum will have higher soil concentrations of (-)-antofine, septicine, and tylophorine. Second, I test the hypothesis that species richness will be lower in plots with higher concentrations of these allelochemicals. Finally, I test the hypothesis that plots with higher allelochemical concentrations will have a direct negative effect on species richness in the following year, and an indirect positive effect on V. rossicum abundance. Soil cores were collected from twelve meadow and nine forest understory sites. In total 168 soil samples were analyzed using ultra-performance liquid chromatography with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOF-MS) to measure the concentration of all three secondary metabolites. The impacts of soil allelochemicals produced by V. rossicum were compared using linear and structural equation models. Overall, the concentrations of soil allelochemicals were all positively correlated with the density of V. rossicum, and species richness was negatively correlated with allelochemical concentrations. Furthermore, our structural equation model provides empirical evidence that these allelochemicals impact V. rossicum abundance but not species richness in the following year. In addition, my findings suggest that allelochemicals produced by V. rossicum varied across habitat-type and allelochemical type, with only (-)-antofine impacting meadow habitat. My research indicates that (-)-antofine may be an important factor, but it is not sufficient, to fully account for the success of V. rossicum.
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    Understanding Canadian Fascism and Neo-fascism from Past to Present: A Critical Coxian Examination
    (2024-05-17) Marmura Brown, Simon Elias; Political Studies; Cox, Wayne
    This dissertation examines the rise and fall of fascist movements from past to present. It is inspired by the emergence of “neo-fascism” in this country and the successes of far-right movements globally. In it, I deploy “Critical Coxian Theory” in novel ways to better understand the antecedents to fascism’s 20th century successes and failures. Specifically, I examine fascism from the 1920s-1940s in both Italy and Canada. Finally, I examine the contemporary Canadian climate and examine purportedly “fascist” movements here. Ultimately, this dissertation operationalizes theory in novel ways, offers a revision of existing fascist taxonomies, conducts a novel examination of Italian and Canadian histories, and examines the potential for future fascist or neo-fascist successes in Canada.
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    An Artist's Almanac to Research, Organization, Education, and Bookings
    (2024-05-17) Lochhead, Neven; Film and Media (Screen Cultures and Curatorial Studies); Kibbins, Gary
    Fusing together current discourses on contemporary artistic research, contemporary art theory, curatorial practice, organizational studies, sound studies, and educational theory, An Artist’s Almanac to Research, Organization, Education, and Bookings is a theoretically diverse dissertation-portfolio that interweaves methodological analysis with applied experimentation. Across four chapters, it examines the epistemological possibilities of art’s status as a form of knowledge, proposes a new theory of curatorial practice through the lens of organizational science, develops an educational philosophy driven by sonic phenomena, and launches a speculative academic discipline called Booking Studies. In its blending of disciplinary forms, which involves academic and conceptual writing, immersive exhibitions, performances, workshop designs, audio works, and films, a set of distinct methodological systems are built, each offering in their own way new perspectives on the possibilities of art-as-research. The author and artist invents, engineers, and implements a range of conceptual tools and vocabularies that help to comprehend and intervene on forces shaping the present regimes of artistic research, namely 'financialization,' 'professionalization,' and 'homogenization.' A consistent intervention upon these impasses throughout is the text’s emphasis on the role of the habitat or ‘scene’ in the trajectories of artistic knowledge, which is conceptualized by the author as an adaptive contextual medium that is always amenable to recalibration, capable of constantly proposing new frames of reference for the aims of practice-led inquiry. This contention is defended both theoretically, in the academic writing, and concretely, in a series of applied projects interwoven throughout the chapters. The nested documentation of these projects both amplifies and dramatizes the dissertation, through a formally varied body of work that reflects the author’s own embedded roles as an artist, curator, and educator. Lochhead's practice-led thinking unfolds as an always responsive process to a range of institutional sites, from which a multifaceted ecology of activity emerges, involving the coordination of artistic research teams and distributed learning environments. In its form and content, this work seeks to expand and reorient the thresholds of art's ‘doctorateness,’ working across platforms and modes of address to persistently evolve its voice into something else.
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    Integrated Photonic Waveguides and Grating Couplers for InP Quantum Optics
    (2024-05-17) Shadkami, Kasra; Physics, Engineering Physics and Astronomy; Rotenberg, Nir
    In the field of telecommunications, the emergence of quantum technologies represents a significant advancement, promising improvements in security, speed, and efficiency. At the core of these innovations lie quantum photonic circuits, complex system with many parts and aspects. These circuits serve as essential foundations in the field of quantum technology. This thesis focuses on two critical aspects of this circuit: grating couplers and waveguides. Grating couplers designed for the critical 1550 nm wavelength are essential for modern optical communication systems. These couplers play a crucial role in integrating quantum technologies into existing infrastructure, thereby enhancing the efficiency and security of communication protocols. Meanwhile, waveguides fulfill the crucial function of confining and directing light between various circuit components. Central to the research goals is the effort to improve grating coupling and waveguide fabrication techniques. Research on grating couplers revolves around optimizing their design to achieve higher efficiency and minimize losses. This includes uniform grating couplers and apodization, with the aim of discovering new strategies to optimize performance at the critical wavelength. Notably, in 3D simulations, apodization grating couplers show an efficiency of approximately 77$\%$ with a bandwidth of about 250 nm. Advanced fabrication techniques are carefully explored to achieve waveguides capable of precisely controlling light propagation. Additionally, significant progress has been made in identifying suitable parameters for the fabrication of 500 nm wide waveguides. This coherent approach emphasizes the comprehensive nature of research and contributes to the advancement of quantum telecommunication platforms with practical insights and experimental validation. Exploration of grating couplers and waveguides includes theoretical fundamentals, simulation methodology, design considerations, fabrication processes, and experimental results. Through a rigorous combination of experimentation and analysis, this research aims to advance quantum telecommunication platforms, thereby facilitating the widespread adoption of secure and efficient quantum computing and communication technologies.

Communities in QSpace

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  • Digital Collections
    This community includes digital collections produced by members of the Queen’s community, as well as digital special collections made available via W.D. Jordan Rare Books & Special Collections.
  • Exams & Syllabi
    This community provides access for staff and students at Queen’s University to degree examination papers and syllabi.
  • Graduate Theses, Dissertations and Projects
    This community includes graduate theses, dissertations and projects produced by students at Queen’s University.
  • Research Data
    This community includes research data produced by faculty and staff at Queen’s University.
  • Scholarly Contributions
    This community includes Queen’s peer-reviewed research publications, including journal articles, book chapters, conference proceedings, and more.