Physical Sciences and Mathematics Commons^™

Luminescence And Structural Properties Of Silicon-Germanium Quantum Structures Fabricated By Ion Implantation, Matheus Coelho Adam

Electronic Thesis and Dissertation Repository

The advancement of semiconductor materials has played a crucial role in driving positive technological breakthroughs that impact humanity in numerous ways. The presence of defects significantly alters the physical properties of semiconductors, making their analysis essential in the fabrication of semiconductor devices. I presented a new method to quantify surface and near-surface defects in single crystal semiconductors. Epitaxially-grown silicon was measured by low energy electron diffraction (LEED) to obtain the surface Debye temperature (θ_D). The results showed the surface θ_D of bulk Si (001), 1.0 μm, and 0.6 μm Si on sapphire of 333 K, 299 K, …

The Study Of Titan's Surface Using Impact Craters And Analogues, Jahnavi Shah

Electronic Thesis and Dissertation Repository

Titan, Saturn’s largest moon, is an icy world harbouring a subsurface water ocean, a substantial atmosphere, and a flowing liquid on its surface. These distinctive characteristics give rise to complex chemical reactions on Titan, and also render it akin to Earth in terms of its landforms and processes. This positions Titan as a key target for studying prebiotic chemistry. NASA's fourth New Frontiers mission, Dragonfly, is poised to explore Titan’s surface in the 2030s. Dragonfly’s primary study site will be Selk crater, a relatively fresh impact crater located in Titan’s equatorial sand seas. Impact craters serve as valuable markers for …

Attribution Robustness Of Neural Networks, Sunanda Gamage

Electronic Thesis and Dissertation Repository

While deep neural networks have demonstrated excellent learning capabilities, explainability of model predictions remains a challenge due to their black box nature. Attributions or feature significance methods are tools for explaining model predictions, facilitating model debugging, human-machine collaborative decision making, and establishing trust and compliance in critical applications. Recent work has shown that attributions of neural networks can be distorted by imperceptible adversarial input perturbations, which makes attributions unreliable as an explainability method. This thesis addresses the research problem of attribution robustness of neural networks and introduces novel techniques that enable robust training at scale.

Firstly, a novel generic framework …

Modeling Thermosyphon And Heat Pipe Performance For Mold Cooling Applications, Dwaipayan Sarkar

Electronic Thesis and Dissertation Repository

Thermosyphons are enhanced heat transfer devices that can continuously transfer very large amounts of heat rapidly over long distances with small temperature differences. The high heat transfer rate is achieved through simultaneous boiling and condensation of the working fluid and the continuous heat transfer is achieved through recirculation of the working fluid in its liquid and vapor phase. A potentially important application of the thermosyphons has been towards reducing the cycle times of the mold cooling processes which would provide economic incentives to the automotive industry.

Different operational and geometrical parameters such as the input heating power, fill ratio (FR), …

Controls On Plastic Debris Capture In Urban Stormwater Drains Of London, Canada: A Study Within The Great Lakes Watershed, Nina Kozikowski

Electronic Thesis and Dissertation Repository

Land-based sources are the greatest contributors of plastic pollution in aquatic environments. Prior to this investigation, there were no available studies concerning the number and types of plastic debris items between 1 mm and 5 mm captured in urban stormwater drains. The present study examined macroplastic (>5 mm) and large microplastic (1-5 mm) debris that accumulated in LittaTrap^TM devices at six drain sites over four seasonal periods in London, Ontario, Canada. Macroplastics (MaPs) and microplastics (MPs) were found in all 36 samples, and the totals ranged from 5-158 MaPs and 18-359 MPs per trap. Out of the 118 …

A Target-Based And A Targetless Extrinsic Calibration Methods For Thermal Camera And 3d Lidar, Farhad Dalirani

Electronic Thesis and Dissertation Repository

This thesis introduces two novel methods for the extrinsic calibration of a thermal camera and a 3D LiDAR sensor, which are crucial for seamless data integration. The first method employs a distinctive calibration target, leveraging lines and plane equations correspondence in both modalities for a single pose, and incorporating more poses by matching the target's edges. It achieves reliable results, even with just one pose yielding 10.82% translation and 0.51-degree rotation errors. This outperforms alternative methods, which require eight pairs for similar results. The second method eliminates the need for a dedicated target. Instead, by collecting data during the sensor …

Luminescent Group 11 Metal (I) Chalcogen Clusters With A Conjugated Diphosphine Ligand, Kai Yu Jeffrey Li

Electronic Thesis and Dissertation Repository

Polynuclear Au (I) complexes exhibit rich photochemical properties and have the potential to find applications as molecular sensors, switches, or energy storage devices. Although dinuclear Au (I) complexes with bridging diphosphines have been extensively examined, most of those reported do not contain rigid-diphosphine ligands.

This thesis examines how the rigid diphosphine, 4,6-bis(diphenylphosphino)dibenzofuran (DBFDP) can be incorporated for the controlled assembly of photoluminescent gold (I) metal – chalcogenolate (chalcogenolate = RS^-, RSe^-; R = organic moiety) and gold (I) chalcogenide (chalcogenide = S^2-, Se^2-) bimetallic complexes. In these studies, the chalcogen …

Exploring The Reactivity Of Metal-Ligand Cooperative Complexes With Dioxazolones, Terminal Alkynes, And 2-Ethynylbenzyl Alcohol, Megan A. Hoffer Miss

Electronic Thesis and Dissertation Repository

N-Acyl ketenimines were attempted to be synthesized catalytically by [Ru(Cp)(P^Ph₂N^Ph₂)(NCMe)]PF₆ with phenylacetylene and 3-phenethynyl-1,2,4-dioxazol-5-one. Trapping agents were employed to identify the major product of the reaction, as many products were formed. [Ru(Cp)(P^Ph₂N^Ph₂)(NCMe)]PF₆ reacts with 3-phenethynyl-1,2,4-dioxazol-5-one generating an isocyanate via the Curtius rearrangement, confirmed by a forced Curtius rearrangement with 3-phenethynyl-1,2,4-dioxazol-5-one and 1,2,4-triazole. Rates of vinylidene formation using [Ru(Cp)(P^Ph₂N^Ph₂)(NCMe)]PF₆ and various terminal alkynes of different sterics and electronics were evaluated using a Hammett analysis for and simple rate comparisons. …