Physical Sciences and Mathematics Commons^™

Estimating Subsurface Anisotropy: Combining Waveform Tomography And Simulated Annealing, Michael Victor Afanasiev

Electronic Thesis and Dissertation Repository

Crosshole seismic tomography has been used by Vale to provide geophysical images of mineralized massive sulphides in the Eastern Deeps deposit at Voisey's Bay. High resolution seismic images are presented by applying acoustic waveform tomography to these data. In waveform tomography, an initial model is required which predicts the first arrival traveltimes to within a half-cycle of the lowest frequency in the data. Because seismic velocity anisotropy can be significant, the initial model must quantify the anisotropy, as well as the velocity, in order to meet the half-cycle criterion.

In our case study, difficulties were encountered in generating an accurate …

Stable Isotopes And Xrd Investigation Of Gold Mineralization At The Syenite-Hosted Young-Davidson Deposit, Matachewan, Ontario, Niloufar Naderi

Electronic Thesis and Dissertation Repository

The Young-Davidson mine is a syenite-hosted orogenic gold deposit at the western end of the Cadillac-Larder-Lake deformation zone in the southern Abitibi greenstone belt, Canada. This study utilized oxygen isotopes to assess the sources of the fluids and evaluate the role of magmatic and metamorphic fluids in gold mineralization. XRD analyses completed on whole-rock powder samples combined with petrography provides a better understanding of the distribution, timing, and nature of alteration patterns and their relationship to gold mineralization.

Temperatures calculated from mineral separates oxygen isotope thermometry indicate the fluids ranged from approximately 322 ± 25° to 431 ± 30°C. The …

Crystal Structure And Al/Si Cation Ordering In "Fassaite": A Combined Single Crystal, 27al And 29si Nmr Study, Monika M. Haring

Electronic Thesis and Dissertation Repository

Al-,Ti-rich diopside, referred to herein as fassaite, occurs in both terrestrial and extraterrestrial environments. The composition of fassaite, Ca(Mg,Al)(Si,Al)₂O₆, makes it ideal for Al/Si cation ordering studies. In this study, crystal XRD, ²⁷Al and 29Si MAS NMR as well as ²⁷Al 3QMAS NMR is used to study cation ordering in extraterrestrial fassaite from Allende CAIs and a terrestrial analogue from Fassa Valley Italy. From ²⁷Al and ²⁹Si spectroscopy, fassaite from Allende CAIs is found to have more local Al/Si cation ordering than terrestrial Fassaite. Both terrestrial and extraterrestrial have C2/c …

Fast Absolute Quantification Of In Vivo Water And Fat Content With Magnetic Resonance Imaging, Yifan Cui

Electronic Thesis and Dissertation Repository

Quantitative water fat imaging offers a non-invasive method for monitoring and staging diseases associated with changes in either water or fat content in tissue. In this work absolute water and fat mass density measurement with in vivo Magnetic Resonance Imaging (MRI) is demonstrated. T₁ independent, T₂^* corrected chemical shift based water-fat separated images are acquired. By placing a phantom with known mass density in the field of view for signal intensity calibration, absolute water or fat mass density can be computed, assuming the B₁⁺ (transmit) and B₁^- (receive) fields can be measured. Phantom …

Automatic Classification Of Epilepsy Lesions, Junwei Sun

Electronic Thesis and Dissertation Repository

Epilepsy is a common and diverse set of chronic neurological disorders characterized by seizures. Epileptic seizures result from abnormal, excessive or hypersynchronous neuronal activity in the brain. Seizure types are organized firstly according to whether the source of the seizure within the brain is localized or distributed. In this work, our objective is to validate the use of MRI (Magnetic Resonance Imaging) for localizing seizure focus for improved surgical planning. We apply computer vision and machine learning techniques to tackle the problem of epilepsy lesion classification. First datasets of digitized histology images from brain cortexes of different patients are obtained …

Automatic Foreground Initialization For Binary Image Segmentation, Wei Li

Electronic Thesis and Dissertation Repository

Foreground segmentation is a fundamental problem in computer vision. A popular approach for foreground extraction is through graph cuts in energy minimization framework. Most existing graph cuts based image segmentation algorithms rely on user’s initialization. In this work, we aim to find an automatic initialization for graph cuts. Unlike many previous methods, no additional training dataset is needed. Collecting a training set is not only expensive and time consuming, but it also may bias the algorithm to the particular data distribution of the collected dataset. We assume that the foreground differs significantly from the background in some unknown feature space …

An Outcome-Based Approach For Ensuring Regulatory Compliance Of Business Processes, Quanjun Yin

Electronic Thesis and Dissertation Repository

In service industries, such as healthcare, catering, tourism, etc., there exist regulations that require organisations’ service comply with the regulations. More and more regulations in the service sector are, or are aimed to be, outcome-focused regulations. An outcome prescribed in the regulation is what users should experience or achieve when the regulated business processes are compliant. Service providers need to proactively ensure that the outcomes specified in the regulations have been achieved prior to conducting the relevant part of the business or prior to inspectors discovering noncompliance. Current approaches check system requirements or business processes, not outcomes, against regulations and …

Charateristics And Impact Of Interpersonal Conflicts On Requirements Risks, Avinder Walia

Electronic Thesis and Dissertation Repository

Interpersonal conflicts in software projects have an impact on project’s success, product’s quality, team’s performance, etc. However, in Requirements Engineering (RE), there is dearth of research on this topic; previous research has focused largely on conflicts among requirements. We conducted a case study of an industrial project to determine the characteristics (e.g., type, severity, conflict management styles, etc.) and impact of interpersonal conflicts rooted in RE (RE-Conflicts), on project risks associated with requirements (e..g., inadequately identified requirements, incorrect requirements, etc). The findings show that the conflicts over administrative procedures (47%) had the highest frequency count. The highest number of …

Synthesis And Characterization Of Copper Nanoparticles And Copper-Polymer Nanocomposites For Plasmonic Photovoltaic Applications, Sabastine Chukwuemeka Ezugwu

Electronic Thesis and Dissertation Repository

Deposition techniques for the fabrication of metal nanostructures influence their morphological properties, which in turn control their optical behavior. Here, copper nanoparticles (np-Cu’s) were grown using a deposition system that was specifically set up during this work, and is based on a radio frequency (RF) sputtering source that can operate at high temperature and under bias voltage. The effect of deposition conditions (RF power, chamber pressure and substrate bias voltage) on RF sputtered np-Cu’s using RF sputtering has been studied. The study included a comparison between the morphological and optical properties of as-grown np-Cu’s and thermally treated samples. The characterization …

Multi-Sensor Calibration And Validation Of The Uwo-Pcl Water Vapour Lidar, Robin Wing

Electronic Thesis and Dissertation Repository

The Purple Crow Lidar (PCL) has recently participated in a water vapour validation cam- paign with the NASA/GSFC Atmospheric Laboratory for Validation/Interagency Collaboration and Education (ALVICE) Lidar. The purpose of this calibration campaign is to insure that PCL water vapour measurements are of sufficient quality for use in scientific investigations of atmo- spheric change, and to be included in the Network for the Detection of Atmospheric Climate Change (NDACC) data base. The detection of long term changes in water vapour concentra- tion, particularly in the upper troposphere and lower stratosphere (UTLS) is an issue of pressing scientific, ecological and societal …

Improvements On Seeding Based Protein Sequence Similarity Search, Weiming Li

Electronic Thesis and Dissertation Repository

The primary goal of bioinformatics is to increase an understanding in the biology of organisms. Computational, statistical, and mathematical theories and techniques have been developed on formal and practical problems that assist to achieve this primary goal. For the past three decades, the primary application of bioinformatics has been biological data analysis. The DNA or protein sequence similarity search is perhaps the most common, yet vitally important task for analyzing biological data.

The sequence similarity search is a process of finding optimal sequence alignments. On the theoretical level, the problem of sequence similarity search is complex. On the applicational level, …

Error Correction In Next Generation Dna Sequencing Data, Michael Z. Molnar

Electronic Thesis and Dissertation Repository

Motivation: High throughput Next Generation Sequencing (NGS) technologies can sequence the genome of a species quickly and cheaply. Errors that are introduced by NGS technologies limit the full potential of the applications that rely on their data. Current techniques used to correct these errors are not sufficient, and a more efficient and accurate program is needed to correct errors.

Results: We have designed and implemented RACER (Rapid Accurate Correction of Errors in Reads), an error correction program that targets the Illumina genome sequencer, which is currently the dominant NGS technology. RACER combines advanced data structures with an intricate analysis of …

Arctic Cold Spring Mineralogy As An Indicator Of Spring Deposits, Water, And Habitable Environments On Mars, Melissa M. Battler

Electronic Thesis and Dissertation Repository

Springs exist in many terrestrial settings and have supported microbial communities throughout Earth’s history. There is mounting evidence for spring deposits on Mars from Noachian age to present, implying that water may be circulating in Mars’ subsurface despite current cold, arid conditions. Current datasets for most of Mars are limited to mineralogy via orbital spectroscopy and geomorphology from visual imagery and laser altimetry. Much is known about terrestrial spring morphology, but few springs exist in Mars analogue settings, and of those, few have been investigated for mineralogy. This study reports on two sets of cold spring sites in the Canadian …

Topographic Influences On Trends And Cycles In Nutrient Export From Forested Catchments On The Precambrian Shield, Samson G. Mengistu

Electronic Thesis and Dissertation Repository

This dissertation explored topographic controls on spatial and temporal patterns in water yield and nutrient (carbon, nitrogen and phosphorus) export from forested headwater catchments in the Turkey Lakes Watershed in central Ontario, where other factors contributing to differences in water yield and nutrient export, including climate, geology, forest, and soils, are relatively constant. Topographic characteristics, including (a) hydrological flushing potential (expansion of water table into nitrate-N producing areas); (b) hydrological storage potential (area of wetlands, which can alternatively allow water and nutrients to bypass wetlands when storage capacity is filled with water or to trap them when not filled); and …

Simultaneous Radar And Video Meteors, Robert J. Weryk

Electronic Thesis and Dissertation Repository

The goal of this thesis is to better understand the physical and chemical properties of meteoroids by using simultaneous radar and video observations of meteors. The Canadian Meteor Orbit Radar (CMOR) and several Gen-III image-intensified CCD cameras were used to measure common meteors and validate metric errors determined through Monte Carlo modelling and to relate radar electron line density (q) to video photon radiant power (I). By adopting an ionisation coefficient from Jones (1997) and using recorded measurements of q/I, a corresponding estimate of the fraction of meteoroid kinetic energy loss converted into light (luminous efficiency) was found.

It was …

A New Algorithm For De Novo Genome Assembly, Md. Bahlul Haider

Electronic Thesis and Dissertation Repository

The enormous amount of short reads produced by next generation sequencing (NGS) techniques such as Roche/454, Illumina/Solexa and SOLiD sequencing opened the possibility of de novo genome assembly. Some of the de novo genome assemblers (e.g., Edena, SGA) use an overlap graph approach to assemble a genome, while others (e.g., ABySS and SOAPdenovo) use a de Bruijn graph approach. Currently, the approaches based on the de Bruijn graph are the most successful, yet their performance is far from being able to assemble entire genomic sequences. We developed a new overlap graph based genome assembler called Paired-End Genome ASsembly Using Short-sequences …

Strength, Elasticity And Phase Transition Study On Nacl And Mgo-Nacl Mixture To Mantle Pressures, Zhongying Mi

Electronic Thesis and Dissertation Repository

Rheological properties of the Earth control most of the important geological processes, such as mantle convection, plate tectonics, earthquakes and nature of thermal evolution. Most parts of the Earth consist of multi-phase polycrystalline aggregates with various composition and compressibility. Therefore, deformation studies on multi-phase materials are important to understand the rheological properties and convection of the Earth. NaCl and MgO with large contrast in elastic properties are excellent analogue materials for modelling the Earth that is generally made of both strong and weak materials. In addition, NaCl and MgO are widely used as pressure transmitting medium and pressure calibration standard …

The Reasonable Effectiveness Of Mathematics In The Natural Sciences, Nicolas Fillion

Electronic Thesis and Dissertation Repository

One of the most unsettling problems in the history of philosophy examines how mathematics can be used to adequately represent the world. An influential thesis, stated by Eugene Wigner in his paper entitled "The Unreasonable Effectiveness of Mathematics in the Natural Sciences," claims that "the miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics is a wonderful gift which we neither understand nor deserve." Contrary to this view, this thesis delineates and implements a strategy to show that the applicability of mathematics is very reasonable indeed.

I distinguish three forms of the …

Optimization Of Chiral Separation Of Nadolol By Simulated Moving Bed Technology, Nesma Nehad Hashem

Electronic Thesis and Dissertation Repository

Simulated Moving Bed (SMB) technology has gained increasing attention as one of the most powerful techniques for chromatographic separations due to its cost-effectiveness and efficiency. Application of SMB technology is especially important in the pharmaceutical industry for production of enantiopure drugs, as required under strict FDA regulations, to avoid possible adverse effects of racemic drugs. In this study, the performance of the SMB process in separation of racemic nadolol on a perphenyl carbamoylated beta cyclodextrin (β-CD) stationary phase was investigated. The equilibrium dispersive model coupled with bi-Langmuir adsorption isotherm and lumped kinetic approximation, constitute the mathematical model used to simulate …

Incomplete Market Models Of Carbon Emissions Markets, Walid Mnif

Electronic Thesis and Dissertation Repository

New regulatory frameworks have been developed with the aim of decreasing global greenhouse gas emissions over both short and long time periods. Incentives must be established to encourage the transition to a clean energy economy. Emissions taxes represent a "price" incentive for this transition, but economists agree this approach is suboptimal. Instead, the "quantity" instrument provided by cap-and-trade markets are superior from an economic point of view. This thesis focuses on the cap-and-trade instrument. Carbon emissions markets have recently been implemented in different countries. We summarize the state of world cap-and-trade schemes. We also provide a literature review of existing …

Studies On Molecular Sieve Crystallization And Heteroatomic Substitution, Adam R. Macintosh

Electronic Thesis and Dissertation Repository

Molecular sieves have been scientifically and industrially important materials since their inception. These porous, crystalline networks of tetrahedrally coordinated atoms bridged by oxygen are known for their extremely high surface area and low density, making them excellent systems for catalysis. The framework of the AlPO₄ family of molecular sieves is itself non-catalytic, but through heteroatomic substitution these materials can diversify into the catalytically active silicoaluminophosphate (SAPO) and metalloaluminophosphate (MAPO) families of heterogeneous acid and redox catalysts. Research into the methods by which these substitutions occur, and the effects therein on the crystallization of the sieves, is of great importance, …

Characterization Of Novel Ichnofossils In Meteorite Impact Glass From The Ries Impact Structure, Germany, Haley M. Sapers

Electronic Thesis and Dissertation Repository

The initial catastrophic biological effects of hypervelocity impacts are well established. However, a growing body of evidence suggests that meteorite impact events have beneficial effects for microbial life. This, in turn, has led many to suggest that impact craters may have been important habitats for life on early Earth. Any large meteorite impact into a water-rich target on a solid planetary body has the potential to generate hydrothermal systems. Impact-generated hydrothermal systems expand the potential environments for microbial colonization to environments without endogenous volcanic heat sources to drive hydrothermal activity. Examination of impact glass from the Ries impact structure, Germany, …

On The Distribution Of Quadratic Expressions In Various Types Of Random Vectors, Ali Akbar Mohsenipour

Electronic Thesis and Dissertation Repository

Several approximations to the distribution of indefinite quadratic expressions in possibly singular Gaussian random vectors and ratios thereof are obtained in this dissertation. It is established that such quadratic expressions can be represented in their most general form as the difference of two positive definite quadratic forms plus a linear combination of Gaussian random variables. New advances on the distribution of quadratic expressions in elliptically contoured vectors, which are expressed as scalar mixtures of Gaussian vectors, are proposed as well. Certain distributional aspects of Hermitian quadratic expressions in complex Gaussian vectors are also investigated. Additionally, approximations to the distributions of …

Strategies For Visco-Acoustic Waveform Inversion In The Laplace-Fourier Domain, With Application To The Nankai Subduction Zone, Rie Kamei

Electronic Thesis and Dissertation Repository

Waveform inversion is a non-linear and ill-posed inverse problem, with the objective of utilizing the full information content of recorded seismic waveforms. A Laplace-Fourier domain implementation allows a natural `multiscale' approach that mitigates the non-linearity and ill-posedness by inverting low-frequency, early arrival data in the initial stages of inversion. High-frequency components, and late arrivals are incorporated at a later stage. This allows the development of robust inversion strategies capable of handling large wide-angle crustal surveys, leading to reliable, high-resolution velocity and attenuation models of crustal structures. I apply waveform inversion to extract a P-wave velocity model of the active megasplay …

Controlled Degradation Of Poly(Ester Amide)S Via Cyclization Of Pendant Functional Groups, Jose Samuel Mejia

Electronic Thesis and Dissertation Repository

Polyesters have been used for many biomedical applications ranging from sutures to drug delivery vehicles. However, their bulk degradation results in an accumulation of acidic byproducts, which is detrimental to the human body. In order to circumvent this problem, as well as to impart new properties and functions to polymers for biomedical applications, poly(ester amide)s (PEAs) have been proposed as a different class of biodegradable polymers. However, up to date, there exists no way to stimulate the degradation of these polymers.

The Gillies research group has previously incorporated self-immolative spacers into polymers and has been able to stimulate their degradation …

The Behavior Of A Falling Particle In A Funnel, Tahani Hassn Aldahri

Electronic Thesis and Dissertation Repository

Recent theoretical work has suggested that a frictional, inelastic, spherical particle falling under gravity through a symmetric funnel will display interesting behavior as a function of the angle of the funnel walls. We have studied this system experimentally, using high-speed video to record the particle trajectories. By analyzing the video images, we have analyzed the time the ball spends in the funnel and its energy loss as functions of the angle of the walls with respect to the horizontal. The coefficient of restitution was also varied by using different balls and funnel materials. We found some similarities and differences between …

Evaluation Of Jarosite As A Biosignature: A Comparison Of Biogenic And Synthetic Jarosites, Liane Loiselle

Electronic Thesis and Dissertation Repository

The detection of jarosite (K)Fe₃(SO₄)₂OH₆ on Mars has been interpreted as mineralogical evidence of acid-sulfate aqueous processes, including putative evidence of biological activity. Terrestrial habitats where acidic conditions occur are environments where microbiota thrive and generate biological signatures. A biotic and synthetic jarosite were produced to evaluate the ability and effectiveness of existing analytical methods to identify biosignatures in targeted geological materials. Using a comprehensive suite of microscopic (light microscopy, SEM and TEM), mineralogical (XRD), spectroscopic (IR, LIBS, Mössbauer, UV-Vis-NIR, and Raman) and mass spectrometry (ToF-SIMS) techniques, the two jarosites were found to …

Geography, News Media Discourse, And Water Management: A Case Study Of The Devils Lake Outlet, Daniel J. Bednar

Electronic Thesis and Dissertation Repository

This thesis explores the print news media discourse surrounding the dispute between Manitoba and North Dakota over a flood mitigation plan in Devils Lake North Dakota. In order to do so, critical discourse analysis was applied to news media from a seventeen year period during the dispute. Findings were compared between media sources as well as to pertinent policy documents. The thesis finds that the political arena provided by local newspapers as well as the discourses of scale, confrontation, history, and economics had the largest effect on the dispute’s public face. A total of nine findings within these areas are …

Diatoms In Castor Lake (North-Central Washington, Usa) – Proxies Of Climate And Hydrologic Variation, Kelly D. Hollingshead

Electronic Thesis and Dissertation Repository

This research provides a high temporal resolution (1 sample / 2-3 years) record of hydrologic variation for the last 2,000 years using a lake sediment record from Castor Lake, a closed-basin system in Washington, USA. The core was dated using ¹³⁷Cs, ¹⁴C, and tephrochronology. Approximately 600 diatoms were identified and enumerated in 198 samples from a Castor Lake freeze core and Livingstone-piston core. A diatom-inference model for salinity was applied to reconstruct fossil diatom salinity. Diatom-inferred salinity for the last century tracked Palmer Drought Severity Index, indicating diatom community composition tracks effective moisture and can be used to …

Evolution Of The Late Ordovician Plaesiomyid Brachiopod Lineage In Laurentia, Colin D. Sproat

Electronic Thesis and Dissertation Repository

During the Late Ordovician, a transgression flooded much of Laurentia. The fauna of these intracratonic basins became differentiated from the fauna of the pericratonic shelves and platforms, typically displaying gigantism and coarser shell ornamentation. In this study, 509 specimens from 11 species of the Plaesiomyidae brachiopod family from the Katian and Hirnantian were measured, of which 198 included in principal component analysis to quantify morphological changes over this interval. Three trends were revealed: 1) increasing globosity and dorsal convexity from the early to late Katian, 2) coarser, but fewer ribs on species from the paleoequatorial intracratonic seas compared to species …