Digital Commons Network^™

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 …

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 …

Bf2obn∙Oet2: A Novel Lewis Acid And Its Use In A Regio- And Stereo-Selective Opening Of Trisubstituted Epoxides And Its Application Towards Amphidinolide C, Nicholas A. Morra, Brian Pagenkopf

Chemistry Publications

The generation of a new Lewis acid (BF2OBn·OEt2) has been reported, and its usefulness has been demonstrated in the regio- and stereoselective ring-opening of trisubstituted epoxides. This Lewis acid is one in a series of new Lewis acids generated from BF3·OEt2 that display varying levels of Lewis acidity. When paired with a modified Shi epoxidation protocol, highly functionalized propionate units, such as those found in a wide variety of natural products, can be accessed. In conjunction with a Mukaiyama oxidative cyclization employing our second generation catalyst Co(nmp)2, this procedure ultimately culminated in the shortest and highest yielding route towards the …

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 …

A Treeboost Model For Software Effort Estimation Based On Use Case Points, Luiz Fernando Capretz, Ali Bou Nassif

Electrical and Computer Engineering Publications

Software effort prediction is an important task in the software development life cycle. Many models including regression models, machine learning models, algorithmic models, expert judgment and estimation by analogy have been widely used to estimate software effort and cost. In this work, a Treeboost (Stochastic Gradient Boosting) model is put forward to predict software effort based on the Use Case Point method. The inputs of the model include software size in use case points, productivity and complexity. A multiple linear regression model was created and the Treeboost model was evaluated against the multiple linear regression model, as well as the …

Estimating Software Effort Using An Ann Model Based On Use Case Points, Ali Bou Nassif, Luiz Fernando Capretz, Danny Ho

Electrical and Computer Engineering Publications

In this paper, we propose a novel Artificial Neural Network (ANN) to predict software effort from use case diagrams based on the Use Case Point (UCP) model. The inputs of this model are software size, productivity and complexity, while the output is the predicted software effort. A multiple linear regression model with three independent variables (same inputs of the ANN) and one dependent variable (effort) is also introduced. Our data repository contains 240 data points in which, 214 are industrial and 26 are educational projects. Both the regression and ANN models were trained using 168 data points and tested using …

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 …

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 …

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 …

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 …

A Conceptual Framework For Measuring The Quality Aspect Of Mobile Learning, Luiz Fernando Capretz, Abdalha Ali, Abdelkader Ouda

Electrical and Computer Engineering Publications

With the continuing growth of mobile phones outpacing that of desktops and laptops, mobile phones are the new personal computer. These devices started becoming increasingly sophisticated and extremely powerful. In addition to making phone calls it have the capabilities to perform variety functions, one of the most important functions using it as a classroom tool. However, mobile phone applications must be designed and developed with respect to different technologies skills, learning capabilities and language proficiency in order to be accepted by wide audiences (e.g., students, instructors). However, there is much work that has been done to measure the quality of …

Topics In Field Theory, Alexander Patrushev

Electronic Thesis and Dissertation Repository

This thesis consists of different projects in classical and quantum field theory on a curved background which are connected by a common usage of theoretical ideas as well as cal- culation techniques. The introduction clarifies such connections. In the second chapter we apply the Dirac constraint formalism to the second and first order 1 + 1 dimensional gravitational action coupled to a scalar field. The third chapter is devoted to a calculation of the one loop effective action for a spinor field coupled to a constant background chiral vector field. In the fourth chapter we find a new expression for …

Late Archean Oceans: A Laboratory Model Of Oxygen Oases, Maija J. Raudsepp

Electronic Thesis and Dissertation Repository

A cyanobacterial mat, including associated aerobic and anaerobic heterotrophs, was grown in an airtight chamber to simulate the formation of an oxygen oasis in two different Archean-like environments. In the first experiment, methane added to the ecosystem was rapidly oxidized and then O_2(g) increased to 10%. Photosynthesis resulted in a pH of 9.5 and the precipitation of magnesium-manganese carbonates within the mat. In the second experiment, daily additions of ferrous iron were rapidly oxidized, resulting in ferric hydroxide encrusted mat. The growth of cyanobacteria and iron reducing bacteria resulted in an active redox cycle between ferrous and ferric iron. …

Scanning Electrochemical Microscopy Studies Of Nickel Surfaces And T24 Single Live Cells, Yu Sun

Electronic Thesis and Dissertation Repository

Scanning electrochemical microscopy offers a good insight into nickel surface analysis and human bladder cancer cell studies.

The surface microstructures are related with chemical reactivity by superimposing SECM, SEM and Tof-SIMS images together. Depth scans were exploited for studying chemical reactivity quantitatively by comparison with COMSOL simulation results. Simulation models are described.

Extracellular reactive oxygen species are detected by SECM. Quantitative results were demonstrated by simulation, and concentrations of H₂O₂ and O₂ were acquired. The interaction between cancer cells and vitamin C was investigated. The switch-type behaviour of vitamin C on the PMA-induced ROS burst of …

Preoperative Planning Of Robotics-Assisted Minimally Invasive Cardiac Surgery Under Uncertainty, Hamidreza Azimian

Electronic Thesis and Dissertation Repository

In this thesis, a computational framework for patient-specific preoperative planning of Robotics-Assisted Minimally Invasive Cardiac Surgery (RAMICS) is developed. It is expected that preoperative planning of RAMICS will improve the rate of success by considering robot kinematics, patient-specific thoracic anatomy, and procedure-specific intraoperative conditions. Given the significant anatomical features localized in the preoperative computed tomography images of a patient's thorax, port locations and robot orientations (with respect to the patient's body coordinate frame) are determined to optimize characteristics such as dexterity, reachability, tool approach angles and maneuverability. In this thesis, two approaches for preoperative planning of RAMICS are proposed that …

A New Web Search Engine With Learning Hierarchy, Da Kuang

Electronic Thesis and Dissertation Repository

Most of the existing web search engines (such as Google and Bing) are in the form of keyword-based search. Typically, after the user issues a query with the keywords, the search engine will return a flat list of results. When the query issued by the user is related to a topic, only the keyword matching may not accurately retrieve the whole set of webpages in that topic. On the other hand, there exists another type of search system, particularly in e-Commerce web- sites, where the user can search in the categories of different faceted hierarchies (e.g., product types and price …

Synthesis Of Silicide Nanomaterials Using Chemical Vapour Deposition Method, Hamid Norouzi Banis

Electronic Thesis and Dissertation Repository

Recent research has evidenced that nanotechnology may bring about a material revolution which sweeps through different scientific fields and leads to dramatic changes in the use of natural resources and our everyday life. Compared to their bulk counterparts, the nanomaterials may exhibit significantly improved physical properties by shrinking their size to nanometer scale. Metal silicide are distinguished by their features of combining advantages of both metals and semiconductors which promises superior performance various fields. Despite the progress in the synthesis methods of nanomaterials, it still remains a big challenge in controlled synthesis of 1D silicide nanostructures due to the difficulties …

Pricing And Trading American Put Options Under Sub-Optimal Exercise Policies, William Wei Xing

Electronic Thesis and Dissertation Repository

No analytical expression has been found for the optimal exercise boundary of finite maturity American put options. This thesis evaluates the performance of approximating the optimal boundary with a class of analytically tractable sub-optimal exercise boundaries which admit known first passage time density functions. The performance is evaluated in two steps, first by computing and comparing the value of the put option under the sub-optimal exercise policy to existing numerical approximation methods such as the binomial price, then by examining the profit/loss of a trader that would result from hedging and trading strategies based on the sub-optimal exercise policy. We …

Migration Behaviour Of Discontinuous Buffers In Capillary Electrophoresis During Protein Enrichment, Ting Li

Electronic Thesis and Dissertation Repository

To enrich protein at sub-microliter sample volumes, our group has developed a discontinuous buffer system which consists of an acid and a base inside a capillary. Upon voltage application, the protein moves towards and stacks at the pH junction. Prior to this work, we only focused on the protein enrichment and have not investigated the migration behaviour of various ions in this system. However, it is important to understand the mechanism of the migration of these ions, because the pH junction formation and further the protein enrichment are based on it. In this work, the ion migration patterns at the …

Further Applications Of Higher-Order Markov Chains And Developments In Regime-Switching Models, Xiaojing Xi

Electronic Thesis and Dissertation Repository

We consider a higher-order hidden Markov models (HMM), also called weak HMM (WHMM), to capture the regime-switching and memory properties of financial time series. A technique of transforming a WHMM into a regular HMM is employed, which in turn enables the development of recursive filters. With the use of the change of reference probability measure methodology and EM algorithm, a dynamic estimation of model parameters is obtained. Several applications and extensions were investigated. WHMM is adopted in describing the evolution of asset prices and its performance is examined through a forecasting analysis. This is extended to the case when the …

The Construction Of Edmond Halley's 1701 Map Of Magnetic Declination, Lori L. Murray

Electronic Thesis and Dissertation Repository

Using the navigational instruments of his time, Edmond Halley collected data during sea voyages of the HMS Paramore. Following these voyages, in 1701 he published a map showing lines of equal magnetic declination. Magnetic declination or variation is the angular difference between magnetic north and geographical or true north for any point on the earth’s surface. The map has been held up by many as an early, and good, example of statistical graphics. Halley did not reveal the data analytic techniques that he used in his map construction and they remain unknown to this day. Using some mathematical tools of …

Simultaneous Confidence Intervals For Risk Ratios In The Many-To-One Comparisons Of Proportions, Jungwon Shin

Electronic Thesis and Dissertation Repository

For many-to-one comparisons of independent binomial proportions using their ratios, we propose the MOVER approach generalizing Fieller's theorem to a ratio of proportions by obtaining variance estimates in the neighbourhood of confidence limits for each proportion. We review two existing methods of inverting Wald and score test statistics and compare their performance with the proposed MOVER approach with score limits and Jeffreys limits for single proportions. As an appropriate multiplicity adjustment incorporating correlations between risk ratios, a Dunnett critical value is computed assuming a common, constant correlation of 0.5 instead of plugging in sample correlation coefficients. The simulation results suggest …

Evaluation And Assessment Of Recommenders Using Monte Carlo Simulation, Renato Costa, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

There have been various definitions, representations and derivations of trust in the context of recommender systems. This article presents a recommender predictive model based on collaborative filtering techniques that incorporate a fuzzy-driven quantifier, which includes two upmost relevant social phenomena parameters to address the vagueness inherent in the assessment of trust in social networks relationships. An experimental evaluation procedure utilizing a case study is conducted to analyze the overall predictive accuracy. These results show that the proposed methodology improves the performance of classical recommender approaches. Possible extensions are then outlined.

A Fuzzy-Based Inference Mechanism Of Trust For Improved Social Recommenders, Renato Costa, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

This paper presents a stochastic model based on Monte Carlo simulation techniques for measuring the performance of recommenders. A general procedure to assess the accuracy of recommendation predictions is presented and implemented in a typical case study where input parameters are treated as random values and recommender errors are estimated using sensitive analysis. The results obtained are presented and a new perspective to the evaluation and assessment of recommender systems is discussed.

Deep Crustal Evolution Of The Western Churchill Province, Nunavut, Canada: Isotopic (U-Pb, O), Trace Element And Micro-Structural Analysis Of Zircon From Lower Crustal Xenoliths, Duane C. Petts

Electronic Thesis and Dissertation Repository

Zircon from lower crustal xenoliths can preserve unique crustal formation records of unexplored levels of the lithosphere. The first such records for the western Churchill province (Nunavut, Canada) are presented here. Zircon SIMS U-Pb geochronology and oxygen isotope analysis were conducted on kimberlite-hosted granulite-facies xenoliths: four metabasites (#9864; #9865; #9866; #9870) from the Rankin Inlet region, and five metabasites (#10162; #10163; #10167; #10169; #10179) and three metatonalite/anorthosites (#10158; #10164; #10168) from the Repulse Bay region. For the Rankin Inlet suite, oscillatory planar zoned, igneous cores from metabolite xenolith #9865 record dates between ca. 2.9–2.6 Ga, whereas complex to radial-sector zoned …

The Synthesis And Reactivity Of New Pnictogen(Iii) Cations, Allison L. Brazeau

Electronic Thesis and Dissertation Repository

Chelating nitrogen based ligands are well known for their use with transition metals while their chemistry with p-block elements has been relatively underdeveloped. This thesis examines the structure, bonding and reactivity of group 15 elements supported by a pyridyl tethered 1,2-bis(imino)acenaphthene (“clamshell”) and various homo- and heteroleptic guanidinate frameworks.

The unique “clamshell” ligand contains a pendant Lewis base and has been used to support N-heterocyclic phosphenium and arsenium cations. Reactivity studies with the phosphorus analogue demonstrate the ability of the ligand to act as a Lewis base, while the phosphorus centre provides a Lewis acidic site, showing the amphoteric …

Usability Bugs In Open Source Software And Online Forums, Arif Raza, Luiz Fernando Capretz, Faheem Ahmed

Electrical and Computer Engineering Publications

No abstract provided.

Electrohydrodynamic Enhancement Of Heat Transfer And Mass Transport In Gaseous Media, Bulk Dielectric Liquids And Dielectric Thin Liquid Films, Seyed Reza Mahmoudi

Electronic Thesis and Dissertation Repository

Controlling transport phenomena in liquid and gaseous media through electrostatic forces has brought new important scientific and industrial applications. Although numerous EHD applications have been explored and extensively studied so far, the fast-growing technologies, mainly in the semiconductor industry, introduce new challenges and demands. These challenges require enhancement of heat transfer and mass transport in small scales (sometimes in molecular scales) to remove highly concentrated heat fluxes from reduced size devices. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in both macro and micro-scale devices.

Several existing problems in EHD heat transfer enhancements were investigated in this thesis. …

Bacterial Communities And Their Influence On The Formation And Development Of Potholes In Sandstone Surfaces Of The Semi-Arid Colorado Plateau, Kebbi A. Hughes

Electronic Thesis and Dissertation Repository

Potholes are weathering features, of various sizes and shapes, which are found in exposed rock surfaces that lack vegetative and soil cover. Biofilms associated with the ephemeral aquatic pothole environments of the Colorado Plateau were examined as initial and intermediate stages of colonisation of arid, oligotrophic rock surfaces.

Imaging of the interface between pothole biofilms and their host rock revealed features of biological weathering; chiefly, the breakdown of silicate minerals and precipitation of clay and carbonate minerals. High pH measured in pothole water reflected deposition of secondary carbonate minerals at some locations and indicated the development of high pH microenvironments …

Metallogenic Setting Of High-Grade Iron Ores, Mary River District, North Baffin Island, Nunavut, Meghan E. Macleod

Electronic Thesis and Dissertation Repository

Supracrustals of the 2.76-2.71 Ga Mary River Group form the northeastern segment of the Committee Bay Belt. Field mapping has determined that this succession is preserved in structural keels marginal to high-grade gneiss domes and is characterized by lower metasedimentary rocks and an upper BIF-komatiite-quartzite succession. Algoma-type BIF sited at the dome/keel boundary is host to bodies of high-grade iron ore, the largest being Deposit 1 which has an estimated reserve of 500 mt averaging 64 wt % Fe.

Field mapping, petrography, and EMPA indicates 3 main stages of ore formation. Stage 1 was characterized by the formation of the …