Physical Sciences and Mathematics Commons^™

The Application Of Geophysical Inversion Techniques To The Nechalacho Rare Earth Element Deposit, Nt, Derek W. Kouhi

Electronic Thesis and Dissertation Repository

The Nechalacho deposit is a world-class rare earth element deposit located in the Thor Lake region approximately 100 kilometers southwest of Yellowknife, NT, Canada. Located within the Blatchford Lake Intrusion Complex, this deposit has the potential to be a large-scale economic asset due to its relatively shallow and sub-horizontal geometry. In this study, geophysical inversion techniques are used to model subsurface magnetic susceptibility and density in order to delineate the deposit. Isolated and joint inversion of both magnetic and gravity data provides similar models. Each inversion procedure delineates a shallow, sub-horizontal layer of high susceptibility and density in approximately the …

Model Of The Formation Of Iron Oxide Nanoparticles By Irradiation In Aqueous Media, Thomas I. Sutherland

Electronic Thesis and Dissertation Repository

This thesis aims to develop the mechanistic understanding of the formation of iron oxide nanoparticles by γ-irradiation. Under irradiation water breaks down into a wide array of redox active species (H•, •OH, H₂O₂, •e^-_(aq)) uniformly throughout the solution. These species are capable of rapidly interconverting any soluble Fe^II and insoluble Fe^III species resulting in the formation of nanoparticles with a narrow size distribution. The initial concentration of Fe²⁺ in the solution, the solution pH, the presence of any radical scavengers, the temperature of the reaction, and the dose rate of …

Nanostructured Air Electrodes And Electrochemical Reaction Mechanism Studies For Sodium-Oxygen Batteries, Hossein Yadegari

Electronic Thesis and Dissertation Repository

Alkali metal-O₂ batteries, i.e. Li- and Na-O₂, are considered as the next generation of energy saving technologies with potential application in electric transportation. The high theoretical energy density in these cells is related to the use of high energy alkali metals as negative and oxygen as the positive electrode materials. The performance of alkali metal-O₂ cells is highly dependent on the positive electrode material, where oxygen reduction and evolution reactions take place. Besides, the primary products of oxygen reduction reaction in these cells are typically metal oxides, which are insoluble in nonaqueous electrolytes, resulting in accumulation …

Essays In Market Structure And Liquidity, Adrian J. Walton

Electronic Thesis and Dissertation Repository

Market structure concerns the mechanisms for negotiating trades and the composition of trading participants, and can affect liquidity and price efficiency. More gains from trade can be realized from an asset that is more liquid, and a better allocation of risk and capital can be achieved when an asset’s price is more efficient so it is important to understand market structure. This thesis uses theory and empirical methods to examine the effects of a few specific aspects of market structure.

In Chapter 1, we study a novel market structure on the New York Stock Exchange (NYSE), the Retail Liqudity Program …

Algorithms For Glycan Structure Identification With Tandem Mass Spectrometry, Weiping Sun

Electronic Thesis and Dissertation Repository

Glycosylation is a frequently observed post-translational modification (PTM) of proteins. It has been estimated over half of eukaryotic proteins in nature are glycoproteins. Glycoprotein analysis plays a vital role in drug preparation. Thus, characterization of glycans that are linked to proteins has become necessary in glycoproteomics. Mass spectrometry has become an effective analytical technique for glycoproteomics analysis because of its high throughput and sensitivity. The large amount of spectral data collected in a mass spectrometry experiment makes manual interpretation impossible and requires effective computational approaches for automated analysis. Different algorithmic solutions have been proposed to address the challenges in glycoproteomics …

Utilization Of Lidar Intensity Data And Passive Visible Imagery For Geological Mapping Of Planetary Surfaces, Taylor M. Haid

Electronic Thesis and Dissertation Repository

While lidar has been historically used for generating digital terrain maps and as a navigation tool, recent research demonstrates that lidar has many potential scientific applications, including high resolution analysis of geological outcrops. Case studies were completed at the Tunnunik impact structure, Victoria Island, Arctic Canada, and the Nickel Rim South mine, Sudbury, Canada, to assess the fidelity of characterizing and differentiating mineralogical and lithological units remotely by integrating passive visible imagery with lidar intensity data. Unsupervised classification via k-means clustering was performed on the fused datasets, with results indicating that lithologies can indeed be successfully differentiated with minor a …

Microstructural Geochronology Of Zircon Across The Central Uplift Of The Vredefort Impact Structure, South Africa, Connor Lawrence Davis

Electronic Thesis and Dissertation Repository

The Vredefort central uplift, or ‘dome,’ represents the erosional remnant of one of the largest (~300 km diameter) and oldest (~2.020 Ga) terrestrial impact structures. This investigation was performed to help elucidate the complexity of the shock process on zircon, incorporating various electron beam methods, including BSE and SE imaging, EBSD, CL, and EDS (mapping and semi-quantitative compositional analysis). A new shock microstructural progression in terrestrial zircon is suggested, as well as a complete structure-wide analysis of impact melt inclusions in zircon. Regional trends in the effects of shock on zircon are included. Impact melt glass inclusion compositions vary widely, …

Investigating Mycotoxins And Secondary Metabolites In Canadian Agricultural Commodities Using High-Resolution Mass Spectrometry, Megan J. Kelman

Electronic Thesis and Dissertation Repository

Mycotoxins are secondary metabolites produced by fungi, which are harmful to humans and/or animals. Alternaria is a common fungal plant pathogen that can produce mycotoxins in agricultural commodities, such as processed wheat products, and fruit juices. Liquid chromatography mass spectrometry (LC-MS) is commonly used for the detection, characterization and quantitation of mycotoxins in agricultural products. Canadian Alternaria species were assessed to provide a risk assessment of their secondary metabolites in agricultural products by describing their global metabolome data obtained from the Orbitrap LC-MS instrument. Combination of this high mass accuracy data with post data-acquisition analysis techniques resulted in the discovery …

Formation And Past Evolution Of The Meteoroid Complex Of Comet 96p/Machholz, Abedin Yusein Abedin

Electronic Thesis and Dissertation Repository

The past dynamical evolution of the meteoroid streams associated with comet 96P/Machholz is investigated. The goal is to obtain a coherent picture of the past capture of this large comet into a short period orbit, and its subsequent breakup hierarchy. In particular, the aim is to constrain the earliest epoch that this large first precursor started to supply meteoroids into the interplanetary space. The fragments and meteoroid streams of that past cometary decay constitute a wide multiplex of interplanetary bodies, knows as the 96P/Machholz complex. The largest presently surviving fragment is comet 96P/Machholz, followed by a large amount of debris …

Emplacement Of The Foy, Hess And Pele Offset Dykes At The Sudbury Impact Structure, Canada, Eric A. Pilles

Electronic Thesis and Dissertation Repository

The 1.85 Ga Sudbury impact structure is the remnant of what is generally considered to have been an ~150–200 km diameter impact basin in central Ontario, Canada. The so-called Offset Dykes are impact melt dykes that are found concentrically around – and extending radially outward from – the Sudbury Igneous Complex (SIC), a ~3 km thick differentiated impact melt sheet. The dykes are typically composed of two main phases of granodiorite: an inclusion- and sulfide-rich granodiorite in the centre of the dyke, and an inclusion- and sulfide-poor granodiorite along the margins of the dyke. This study uses a combination of …

Constraining The Formation And Alteration Of Sudbury Breccia, Ontario, Canada: Implications For Footwall Cu-Ni-Pge Exploration, Jonathan W. O'Callaghan

Electronic Thesis and Dissertation Repository

Sudbury breccia is an impactite situated in the footwall of the 1.85 Ga Sudbury impact structure, situated in Ontario. Developing exploration vectors towards Sudbury breccia-hosted Cu-Ni-PGE mineralization is inhibited by an insufficient understanding of the relative contributions of footwall lithologies versus impact melt. By combining whole-rock geochemistry, field observations, statistical modelling and petrography, this study has determined that Sudbury breccia is a parautochthonous shock melt, which does not require a melt sheet contribution. Furthermore, the trace metal content of the breccia is largely controlled by the assimilation of mafic footwall lithologies, the exception being breccia proximal to mineralization, where a …

Novel Reactions Of Donor-Acceptor Cyclopropanes, And Diels-Alder Approach Towards Fargesine And Fumimycin, Polydoros Kyriacou

Electronic Thesis and Dissertation Repository

The first chapter of this thesis consists of two related projects that explore novel reactivity of donor-acceptor cyclopropanes, specifically 2-substituted cyclopropane 1,1-diesters. The first project involves the nucleophilic ring opening of donor-acceptor cyclopropanes with potassium organotrifluoroborates. It was found that during the ring opening of the cyclopropane, the diesters of the cyclopropane formed a malonyl-BF₂ complex. The complex could then be hydrolyzed to afford substituted malonates. The reaction was limited to aryl cyclopropanes and potassium alkynyltrifluoroborates. The second project in this chapter explores modifying the Kerr group’s previous synthesis of tetrahydro-1,2-oxazines, such that geminal allyl, methyl esters are now …

Fabricating And Characterizing Chalcogenide Thin Films As Light Absorbing Layers In Solar Cells, Daniel Vaccarello

Electronic Thesis and Dissertation Repository

Solar cell development has been a focus in energy research, with light-absorbing layers as the key theme. Copper indium disulphide (CuInS₂) and copper zinc tin sulphide (Cu₂ZnSnS₄ or CZTS) have energy band gaps that are optimal for solar energy conversion. New preparation methods have been developed with practicality, safety, and low costs in mind. The one-pot method developed in this thesis group has been utilized to create nanocrystals that can be used to absorb light and generate current. The use of low temperatures and minimalistic reaction conditions has led to the production of CIS and …

Hydraulic And Electrokinetic Delivery Of Remediants For In-Situ Remediation, Ahmed I. A. Chowdhury

Electronic Thesis and Dissertation Repository

Nano-scale zero valent iron (nZVI) has shown promising mobility and in-situ reactivity with chlorinated volatile organic compounds when injected into saturated porous media. The current study evaluated nZVI mobility and subsequent reactivity with in-situ contaminants in a variably saturated porous media. The nZVI particles, synthesized onsite at subzero temperatures, demonstrated complete trichloroethene (TCE) degradation within the target area. Furthermore, a three dimensional finite difference model (CompSim) was utilized to investigate nZVI mobility in variably saturated zones. Model predicted well head data were in very good agreement with field observations. Simulation results showed that the injected slurry migrated radially outward from …

Advances In Portmanteau Diagnostic Tests, Jinkun Xiao

Electronic Thesis and Dissertation Repository

Portmanteau test serves an important role in model diagnostics for Box-Jenkins Modelling procedures. A large number of Portmanteau test based on the autocorrelation function are proposed for a general purpose goodness-of-fit test. Since the asymptotic distributions for the statistics has a complicated form which makes it hard to obtain the p-value directly, the gamma approximation is introduced to obtain the p-value. But the approximation will inevitably introduce approximation errors and needs a large number of observations to yield a good approximation. To avoid some pitfalls in the approximation, the Lin-Mcleod Test is further proposed to obtain a numeric solution to …

Dicke’S Superradiance In Astrophysics, Fereshteh Rajabi

Electronic Thesis and Dissertation Repository

It is generally assumed that in the interstellar medium much of the emission emanating from atomic and molecular transitions within a radiating gas happen independently for each atom or molecule, but as was pointed out by R. H. Dicke in a seminal paper several decades ago this assumption does not apply in all conditions. As will be discussed in this thesis, and following Dicke’s original analysis, closely packed atoms/molecules can interact with their common electromagnetic field and radiate coherently through an effect he named superradiance. Superradiance is a cooperative quantum mechanical phenomenon characterized by high intensity, spatially compact, burst-like features …

Complex Event Processing As A Service In Multi-Cloud Environments, Wilson A. Higashino

Electronic Thesis and Dissertation Repository

The rise of mobile technologies and the Internet of Things, combined with advances in Web technologies, have created a new Big Data world in which the volume and velocity of data generation have achieved an unprecedented scale. As a technology created to process continuous streams of data, Complex Event Processing (CEP) has been often related to Big Data and used as a tool to obtain real-time insights. However, despite this recent surge of interest, the CEP market is still dominated by solutions that are costly and inflexible or too low-level and hard to operate.

To address these problems, this research …

Molecular Distance Maps: An Alignment-Free Computational Tool For Analyzing And Visualizing Dna Sequences' Interrelationships, Rallis Karamichalis

Electronic Thesis and Dissertation Repository

In an attempt to identify and classify species based on genetic evidence, we propose a novel combination of methods to quantify and visualize the interrelationships between thousand of species. This is possible by using Chaos Game Representation (CGR) of DNA sequences to compute genomic signatures which we then compare by computing pairwise distances. In the last step, the original DNA sequences are embedded in a high dimensional space using Multi-Dimensional Scaling (MDS) before everything is projected on a Euclidean 3D space.

To start with, we apply this method to a mitochondrial DNA dataset from NCBI containing over 3,000 species. The …

A Data Fusion Approach To Automated Decision Making In Intelligent Vehicles, Besat Zardosht

Electronic Thesis and Dissertation Repository

The goal of an intelligent transportation system is to increase safety, convenience and efficiency in driving. Besides these obvious advantages, the integration of intelligent features and autonomous functionalities on vehicles will lead to major economic benefits from reduced fuel consumption to efficient exploitation of the road network.

While giving this information to the driver can be useful, there is also the possibility of overloading the driver with too much information. Existing vehicles already have some mechanisms to take certain actions if the driver fails to act. Future vehicles will need more complex decision making modules which receive the raw data …

Collective Contextual Anomaly Detection For Building Energy Consumption, Daniel Berhane Araya

Electronic Thesis and Dissertation Repository

Commercial and residential buildings are responsible for a substantial portion of total global energy consumption and as a result make a significant contribution to global carbon emissions. Hence, energy-saving goals that target buildings can have a major impact in reducing environmental damage. During building operation, a significant amount of energy is wasted due to equipment and human-related faults. To reduce waste, today's smart buildings monitor energy usage with the aim of identifying abnormal consumption behaviour and notifying the building manager to implement appropriate energy-saving procedures. To this end, this research proposes the \textit{ensemble anomaly detection} (EAD) framework. The EAD is …

Agora: A Knowledge Marketplace For Machine Learning, Mauro Ribeiro

Electronic Thesis and Dissertation Repository

More and more data are becoming part of people's lives. With the popularization of technologies like sensors, and the Internet of Things, data gathering is becoming possible and accessible for users. With these data in hand, users should be able to extract insights from them, and they want results as soon as possible. Average users have little or no experience in data analytics and machine learning and are not great observers who can collect enough data to build their own machine learning models. With large quantities of similar data being generated around the world and many machine learning models being …

The Spectral Variability Of Astronomical Pahs, Matthew Shannon

Electronic Thesis and Dissertation Repository

Polycyclic aromatic hydrocarbons (PAHs) are highly abundant molecules found throughout the universe. Illuminated by ultraviolet photons, they can emit up to 10% of the total power output of star-forming galaxies and are involved in many important physical and chemical processes (e.g., gas heating). They produce prominent emission bands between 3-20 μm which vary strongly in intensity and spectral profile. The origins of these variations are not fully understood, which limits the use of PAHs as (ubiquitous) diagnostic tracers of physical conditions. To characterize their variability, we studied the relative intensities and profiles of the 10-20 μm PAH bands in a …

Martian Gully Formation And Evolution: Studies From The Local To Global Scale, Tanya Nicole Harrison

Electronic Thesis and Dissertation Repository

Gullies in the mid- and high-latitudes of Mars were first observed in Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images in 1997. Appearing to be geologically young, they quickly became a feature of interest due to the implication of liquid water in their formation based on distinct morphological characteristics including incised channels, many exhibiting features indicative of fluid flow. However, the temperature and pressure conditions on the surface of Mars during its most recent geologic era have not been conducive to sustaining water in the liquid phase for extended periods of time; therefore, a number of “wet” (water-related) and …

Development Of Novel Anode Materials For Lithium Ion Batteries, Mike A. Nieradko

Electronic Thesis and Dissertation Repository

This thesis focuses on the development of new anodes for Li ion batteries. Aluminium has been long considered as promising anode material for Li ion batteries because of its low cost, abundance, and low toxicity. Aluminium undergoes alloying with lithium through intermetallic LiAl formation which offers a relatively high theoretical capacity of 993 mAh/g compared to 372 mAh/g for graphite that is currently the principal anode material in commercial Li ion batteries. However, despite intensive research, all aluminium-based anodes tested so far suffered from rapid capacity fading and failure within first few cycles. Furthermore, there is insufficient understanding of the …

Stratigraphy, Sedimentology And Paleogeography Of The Lower Cretaceous (Upper Albian) Peace River, Joli Fou And Pelican Formations, Northern Alberta, Canada, Kathleen Vannelli

Electronic Thesis and Dissertation Repository

Late Albian (~ 104-101 Ma) strata in northern Alberta are assigned to the marginal-marine Paddy Member, and the marine Joli Fou, Pelican and Viking formations. Temporal relationships between these units have never been established in detail. This study shows that the marine Joli Fou mudstone forms a sheet that onlaps westward against a subaerial ridge (?forebulge); coeval fluvio-lagoonal lower Paddy strata onlap against the opposite side. The ridge crest was buried by upper Paddy strata, of Cordilleran provenance, that grade eastward into deltaic lower Pelican quartz arenites derived from the Canadian Shield. The presence of quartz arenites in the Peace …

Similarity, Adequacy, And Purpose: Understanding The Success Of Scientific Models, Melissa Jacquart

Electronic Thesis and Dissertation Repository

A central component to scientific practice is the construction and use of scientific models. Scientists believe that the success of a model justifies making claims that go beyond the model itself. However, philosophical analysis of models suggests that drawing inferences about the world from successful models is more complex. In this dissertation I develop a framework that can help disentangle the related strands of evaluation of model success, model extendibility, and the ability to draw ampliative inferences about the world from models.

I present and critically assess two leading accounts of model assessment, arguing that neither is sufficient to provide …

Parametric Design, Modeling, And Optical Evaluation Of Retroreflective Prismatic Structures, Sama Hussein

Electronic Thesis and Dissertation Repository

Retroreflectors (RR) are defined as passive optical structures that redirect incident light to its originating source. Specific types of retroreflectors called inverted cubes (ICs) function through total internal reflection (TIR) and are used in various applications such as measurement tools, traffic signs and automotive rear and side lighting. This thesis aims to model, analyze, fabricate and study a novel type of IC retroreflectors called right triangular prism (RTP). A parametric approach is used to model existing IC geometries from a generic unit cube and is then implemented to model the novel RTP geometry. Those elements are then tested by optical …

What Governs Star Formation In Galaxies? A Modern Statistical Approach, Sahar Rahmani

Electronic Thesis and Dissertation Repository

Understanding the process of star formation is one of the key steps in understanding the formation and evolution of galaxies. In this thesis, I address the empirical star formation laws, and study the properties of galaxies that can affect the star formation rate.

The Andromeda galaxy (M31) is the nearest large spiral galaxy, and Therefore, high resolution images of this galaxy are available. These images provide data from various regions with different physical properties. Star formation rate and gas mass surface densities of M31have been measured using three different methods, and have been used to compare different star formation laws …

Photo-Isomerizable Self-Complementary Hydrogen Bond Arrays, Iamnica Janic Linares Mendez

Electronic Thesis and Dissertation Repository

This thesis exploits the use of a photochromic system in a self-complementary hydrogen bond array; i.e. the azo group, -N=N. The novelty of the approach described in this thesis resides in the double function of the azo group within the array: as a hydrogen bond acceptor site and as an element that promotes a structural change capable of disrupting the complexation equilibrium when irradiated with light.

The photo-isomerizable self-complementary hydrogen bond arrays presented are obtained by a general and practical synthetic method from inexpensive starting materials. Their self-complementary recognition was corroborated by ¹H NMR dilution experiments and single crystal …

First Major Appearance Of Brachiopod-Dominated Benthic Shelly Communities In The Reef Ecosystem During The Early Silurian, Cale A.C. Gushulak

Electronic Thesis and Dissertation Repository

The early Silurian reefs of the Attawapiskat Formation in the Hudson Bay Basin preserved the oldest record of major invasion of the coral-stromatoporoid skeletal reefs by brachiopods and other marine shelly benthos, providing an excellent opportunity for studying the early evolution, functional morphology, and community organization of the rich and diverse reef-dwelling brachiopods. Biometric and multivariate analysis demonstrate that the reef-dwelling Pentameroides septentrionalis evolved from the level-bottom-dwelling Pentameroides subrectus to develop a larger and more globular shell. The reef-dwelling brachiopods in the paleoequatorial Hudson Bay Basin were more diverse than contemporaneous higher latitude reef-dwelling brachiopod faunas, with ten distinct …