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The Effects Of Solution Ph, Temperature And Redox Environment On Corrosion And Oxide Formation On Inconel X-750, Mohsen Bahrami

Electronic Thesis and Dissertation Repository

Nickel-based superalloys have a wide range of applications in different industries due to their exceptional mechanical and corrosion-resistance properties. These alloys are widely employed in the nuclear industry. Inside a nuclear reactor, these alloys are exposed to a continuous flux of gamma-radiation. When exposed to gamma-radiation, water decomposes, resulting in the production of oxidizing and reducing species. These species have a considerable effect on the redox chemistry of the solution, which controls the overall corrosion behaviour of nickel-based superalloys.

Corrosion of metals and alloys involves several elementary steps. A comprehensive understanding of these steps and how they influence each other …

Brown Dwarf Atmospheres At High Cadence And Spectral Resolution: A Speed Limit On Brown Dwarf Rotation And A Spectroscopic Atlas Of A 1050 K Atmosphere, Megan E. Tannock

Electronic Thesis and Dissertation Repository

Brown dwarfs are sub-stellar objects that form like stars but are not sufficiently massive to sustain hydrogen fusion in their cores. Characterized by cool, molecule-rich atmospheres, brown dwarfs demonstrate great diversity in spectroscopic appearance and share many properties with giant exoplanets. In this thesis I present two investigations: the first is a detailed photometric and spectroscopic study of the three most rapidly rotating brown dwarfs. The second examines a spectrum of a cool brown dwarf at unprecedented spectral resolution and signal-to-noise ratio to study the accuracy of theoretical model photospheres.

Photometric monitoring of brown dwarfs has revealed that periodic variability …

How Can Local Transitional Justice Mechanisms Work Towards Measures Of Non-Recurrence?, Isaac Bayor

Electronic Thesis and Dissertation Repository

This dissertation examines questions of local agency and inclusion. It develops a conceptual understanding of whether, and if so how, local customary justice mechanisms could serve as guarantees of non-recurrence. It looks at how grassroots practices of “justice” could be utilized at the community level to deter the commission of future abuses and prevent the repetition of violent conflict, especially where the state has been completely absent. It specifically explores Acholi indigenous and customary practices of peacemaking and justice in Northern Uganda to understand how local practices could secure a lasting peace and cement communities’ commitment to peaceful coexistence.

While …

Behaviour Of Transmission Line Conductors Under Tornadoes, Dingyu Yao

Electronic Thesis and Dissertation Repository

Transmission line (TL) structure failures caused by tornadoes have been observed in multiple countries around the globe. The objective of this study is to develop an accurate load case that can simulate the critical tornado forces transmitted from the TL conductors to the towers. In order to achieve the goal, three different tornado wind fields, which were previously developed using computational fluid dynamic simulations, are considered. The tornado wind field provides the most critical forces on the TL conductors is determined and considered to obtain the critical load cases. Using the critical wind field, parametric studies are conducted to identify …

Fear Of The Human "Super-Predator" In African Mammals, Nikita R. Frizzelle

Electronic Thesis and Dissertation Repository

Humans’ exploitive killing of virtually every mammal species globally may result in a perception of humans as feared, ultra-lethal predators. In Africa, mammals are central to the continent’s tourism industry; however, it is largely unknown whether African mammals fear the presence of tourists. Firstly, I aimed to review how the presence of humans on the landscape affects African mammal behaviour. Of 31 studies, most authors reported that humans alter mammal behaviour in a manner that may negatively impact survival. To test if a fear of humans can pervade communities, I simulated the presence of humans, hunting, lions, and birds using …

Improving Developing Countries’ Health Information Systems Capacity For Infectious Disease Pandemic Responses: A Case Study Of The Ebola Virus Disease And The Coronavirus Disease Pandemics, Uche Ikenyei

Electronic Thesis and Dissertation Repository

There is increasing evidence to demonstrate that current information system theoretical models meant to assess the success of the health information systems (HIS) lack the applicable theoretical underpinning suitable for developing countries. This stems partly from a theory-evidence gap where theoretical models developed in the West are applied in developing country contexts but lack tailoring to localized, contextual realities. Therefore, this study addresses this gap by enhancing the DeLeon and McLean's information system success model with six contextual factors peculiar to the infectious disease HISs in a developing country context.

This study took place in two developing countries, Liberia and …

Behaviour Of Transmission Lines Subjected To Tornadoes Through Aeroelastic Testing And Numerical Modeling, Nima Ezami

Electronic Thesis and Dissertation Repository

Tornadoes, as a form of high intensity wind (HIW) events, represent major threats to transmission line systems in many regions around the globe. Transmission line systems are among the most vulnerable structures to tornadoes due to their expansion over hundreds of kilometers and, therefore, increased exposure to such localized wind events. A comprehensive research project has been developed over the past two decades at Western University to study this problem. The research conducted in this thesis provides a significant development to the advancement of knowledge in this area through achieving three main objectives. The first objective is to assess and …

Short-Term Vs. Long-Term Warming And Nitrogen Treatment Effects On Soil Carbon And Microbial Activity In A Temperate Old Field, Erica Stroud

Electronic Thesis and Dissertation Repository

Climate warming and atmospheric nitrogen deposition, two elements of global change, are expected to exert strong effects on northern temperate ecosystems over the next century. I added new nitrogen addition and warming plots to a pre-existing nitrogen and warming field experiment in London, Ontario to compare the short-term (1-2 year; new plots) versus long-term (14-15 year; old plots) treatment effects on soil carbon and microbial activity. I used soil density fractionation and size fractionation to separate soil carbon fractions and analyzed carbon quality using Fourier-transform infrared spectroscopy (FTIR). I used extracellular enzyme assays to assess microbial activities. The soil organic …

Seismic Response Of Driven And Helical Piles In Non-Liquefiable And Liquefiable Soils, Ahmed Fouad Hussein

Electronic Thesis and Dissertation Repository

The thesis investigates the nonlinear soil-pile-structure interaction through three-dimensional nonlinear finite element models (FEM) employing the OpenSees platform. The FEMs were validated with the results of large-scale shaking table tests of model pile groups-superstructure systems in dry and saturated sand and large-scale field tests on single piles installed in cohesive soil. The numerical models correctly predicted the different pile deformation modes that were exhibited in the experiments. The results illustrated that the inertial interaction contributed to the bending moments at the pile top, while the kinematic interaction contributed to the bending moment at the layers interface. In addition, the excess …

Behavior Of Wind Turbine Towers And Blades Under Tornado Wind Fields, Mohamed Abugazia

Electronic Thesis and Dissertation Repository

The installation rate of wind turbines around the world is increasing significantly. Therefore, wind turbine farms are constructed in plentiful wind resources areas that put a considerable number of wind turbine towers under severe wind conditions. As a result, failures due to unexpected wind loads on either the blades or the tower are increasing. In addition, wind turbines are designed to resist synoptic wind loads as per the current guidelines, which do not consider high-intensity wind (HIW) events such as tornadoes. The built-in-house numerical code “HIW-WT” has been developed in this study to model wind turbines under three-dimensional wind fields …

Consideration Of Executive Functioning For Physiotherapy Rehabilitation: Studies Of Physiotherapists’ Knowledge, Normative Data, And A Practice Application, Nicole A. Guitar

Electronic Thesis and Dissertation Repository

Executive functioning (EF) refers to cognitive abilities involved in decision-making and self-regulation and can be impaired in many patients referred for physiotherapy, including older adults and people living with chronic pain. This dissertation aimed to determine what physiotherapists understood about EF, to summarize normative data for application in physiotherapy practice, and to provide an assessment of feasibility for studying EF impairments in people living with chronic pain. Study one surveyed what physiotherapists understood about EF as a concept, what EF assessments they used, and if this was influenced by their primary area of practice. Respondents (N = 262) subjectively reported …

Hibernation Is Super Complex: Dynamics Of Electron Transport System Supercomplexes, Amalie J. Hutchinson

Electronic Thesis and Dissertation Repository

The electron transport system complexes form supercomplexes (SCs) within mitochondrial membranes, perhaps increasing respiratory capacity or reducing reactive oxygen species production. My project aimed to determine the abundance, composition, and stability of SCs in a hibernator. Hibernators have dynamic metabolisms that change greatly during the winter. I isolated mitochondria from rats and thirteen-lined ground squirrels (TLGS) in different hibernation states and measured mitochondrial respiration. I extracted mitochondrial proteins using two detergents of different strengths, and quantified SC abundance using 2-dimensional gel electrophoresis and immunoblotting. Rats had fewer SCs than TLGS. SCs are dynamic in hibernation and the complex III composition …

Precision Grasp Planning For Integrated Arm-Hand Systems, Shuwei Qiu

Electronic Thesis and Dissertation Repository

The demographic shift has caused labor shortages across the world, and it seems inevitable to rely on robots more than ever to fill the widening gap in the workforce. The robotic replacement of human workers necessitates the ability of autonomous grasping as the most natural but rather a vital part of almost all activities. Among different types of grasping, fingertip grasping attracts much attention because of its superior performance for dexterous manipulation. This thesis contributes to autonomous fingertip grasping in four areas including hand-eye calibration, grasp quality evaluation, inverse kinematics (IK) solution of robotic arm-hand systems, and simultaneous achievement of …

Effect Of Pretreatment Of Resin Acids On Anaerobic Digestibility Of Pulp And Paper Mill's Primary Sludge, Sreejon Das

Electronic Thesis and Dissertation Repository

Pulp and paper (P&P) mills’ wastewater contain high concentrations of resin acids (10–10,000 mg/L) which are toxic to aquatic organisms. In mill’s primary and waste activated sludge treatments reduced concentrations of resin acids in effluent; however, most of the resin acids are ultimately ended up in sludge after primary and secondary clarification due to their extreme hydrophobic nature (log K_ow 6.0). Nevertheless, adsorbed resin acids on the surfaces of anaerobes and substrates affect anaerobic digestion (AD) process negatively. The objective of the present work was to determine the effect of pretreatment of thermomechanical pulping mill’s primary sludge (TMP-PS) on …

Equisingular Approximation Of Analytic Germs, Aftab Yusuf Patel

Electronic Thesis and Dissertation Repository

This thesis deals with the problem of approximating germs of real or complex analytic spaces by Nash or algebraic germs. In particular, we investigate the problem of approximating analytic germs in various ways while preserving the Hilbert-Samuel function, which is of importance in the resolution of singularities. We first show that analytic germs that are complete intersections can be arbitrarily closely approximated by algebraic germs which are complete intersections with the same Hilbert-Samuel function. We then show that analytic germs whose local rings are Cohen-Macaulay can be arbitrarily closely approximated by Nash germs whose local rings are Cohen- Macaulay and …

A Visual Analytics System For Rapid Sensemaking Of Scientific Documents, Amirreza Haghverdiloo Barzegar

Electronic Thesis and Dissertation Repository

With the rapid growth of scientific documents over the years, researchers must examine large collections of documents to keep up with their research fields. Over the past years, numerous tools have been developed to support researchers in making sense of the documents collection; however, due to the high load and complexity of scientific information, many of these tools have only covered basic tasks or restricted information items. This thesis describes a visual analytics system (i.e., a tool that integrates data visualization, human-data interaction, and machine learning) that helps researchers explore and examine scientific documents thoroughly and rapidly with an especial …

Exercise As A Treatment For Cognitive Decline In Older Adults: The Role Of Growth Factors And Inflammatory Cytokines, Joshua A. Titus

Electronic Thesis and Dissertation Repository

The purpose of this thesis was to investigate the effects that exercise modalities have on neurotrophic and inflammatory blood markers and cognitive outcomes in older adults. A systematic review and meta-analysis were completed. The included studies illustrated that most of the literature evaluated the effect of aerobic exercise interventions on systemic concentrations of the blood marker brain-derived neurotrophic factor (BDNF). The review found that aerobic exercise increases BDNF and resistance training increases insulin-like growth factor 1 (IGF-1). Interventions with sex-specific cohorts presented advantages in males for blood marker and cognitive outcomes compared to females. One of three included interventions decreased …

Treatability Of Micropollutants And Microplastics Using Selected Wastewater Treatment Processes, Juan Li

Electronic Thesis and Dissertation Repository

Micropollutants and microplastics are ubiquitously detected in environment, which are directly linked to human health and ecosystems safety. Conventional wastewater treatment plants (WWTPs) are regarded as a major source for discharging these contaminants into environment. Therefore, it is of great significance to study the behavior of these pollutants and their removal potential in WWTPs. This work investigated specific treatment processes to determine their efficiency in removing target micropollutants and microplastics.

Primary treatments in WWTPs are first step to removal solid particle and other floated materials from the water stream. Therefore, the process is important for microplastics particles. The behavior of …

The Use Of Ct To Assess Shoulder Kinematics And Measure Glenohumeral Arthrokinematics, Baraa Daher

Electronic Thesis and Dissertation Repository

Recently, studies have started employing dynamic four-dimensional computed tomography (4DCT) imaging as a biomechanical assessment tool. These studies would benefit from the valuable work that has been done in the past using three-dimensional computed tomography (3DCT). Thus, a structured review was conducted to examine the extent and range of methods employing CT imaging to measure shoulder kinematics. The findings of the review were utilized to conduct a study that employed 4DCT imaging to measure glenohumeral joint congruency and arthrokinematics during internal rotation to the back in a population of healthy individuals. The results of this work show the importance of …

The Role Of Exogenous Ketones On Various Aspects Of Exercise Performance, Manuel D. Quinones

Electronic Thesis and Dissertation Repository

Routinely, athletes and coaches pursue novel nutritional strategies in an attempt to support exercise training techniques and/or enhance athletic performance. Body carbohydrate (CHO) stores are limited so strategies to enhance fat use and spare CHO during exercise and thus, attenuate the onset of fatigue are commonplace. It has been suggested that oral exogenous ketone administration is ergogenic not only by altering exercise metabolism (sparing CHO), but also by improving exercise cognitive function as well as enhancing post-exercise glycogen resynthesis. However, data supporting these claims are limited and contradictory. Therefore, the purpose of this dissertation was to explore the role of …

Static Liquefaction Of Oil Sand Tailings: An Experimental Investigation Into The Effect Of Saturation And Fines Content, Farshad Zehforoosh

Electronic Thesis and Dissertation Repository

The main goals of this research are to explore the influence of partial saturation and fine content on the shear response of oil sand tailings, to identify the liquefaction susceptibility under different initial states. Monotonic triaxial compression tests were carried out to understand the mechanical behavior of the saturated oil sand tailings with varying void ratios. Then the effect of fine content on the yield and critical shear strength, critical state line, and instability line was evaluated by increasing the fine content up to 50%. The experimental results revealed that the shear strength of the oil sand increases with fine …

Edge Intelligence Enabled Distributed And Collaborative Authentication In Uav Swarms, Huanchi Wang

Electronic Thesis and Dissertation Repository

Unmanned Aerial Vehicles (UAVs) have been widely deployed in various fields with many benefits such as cost reduction, safety improvement and service coverage enhancement. Unlike the other mobile ad hoc networks, the UAV swarm, which is a flying ad hoc network, may operate in a hostile environment or experience rapid network topology change which brings high vulnerability by using cloud-based centralized security provisioning techniques. Hence, securing the UAV networks with the on-site authentication resources becomes a vital aspect to accomplish the mission. The on-site authentication resources, such as the cross-layer attributes, can be utilized to form a unique characteristic of …

Health Providers Perspectives On The Access And Use Of Formal Health And Social Services By Stroke Caregivers, Hannah Pollock

Electronic Thesis and Dissertation Repository

Informal stroke caregivers, comprised of family and friends, can experience prolonged stress that places them at risk of poor health and social outcomes. These caregivers may benefit from formal health and social services, but they are often underused and challenging to access. This qualitative interpretive description study sought to explore health providers’ perspectives on the factors that impact stroke caregivers' access and use of formal health and social services. In addition, it sought to explore health providers' experiences and how they perceive their role in supporting stroke caregivers'. In-depth, semi-structured interviews were conducted with 18 health providers. Through inductive thematic …

Falls Screening In Community- Dwelling Older Adults, Hadi Kooshiar

Electronic Thesis and Dissertation Repository

Falls screening can prevent falls and their consequences. The two studies of this thesis aimed to identify the accuracy of falls screening tools and explore patient preferences and empirical validity of the self-rated Falls Risk Questionnaire (FRQ). The first study, Systematic Literature Review, found the Toulouse-St. Louis University Mini Falls Assessment and the Activities-specific Balance Confidence scale Hindi version emerged as accurate tools for predicting falls in the target population. The second study determined most of respondents, 36%, had no preference between Activities Specific Balance Confidence 6 items (ABC-6) or FRQ. The Bland & Altman approach revealed a degree of …

Effects Of The Soil Spatial Variability On Pipelines, Jose Luis Espinosa Mendez

Electronic Thesis and Dissertation Repository

Pipelines are the safest and most efficient way to transport large volumes of oil and gas from extraction fields, to refineries, industry and home consumption. Extensively used to transport fluids over long distances, pipelines may pass through terrain features exposed to geohazards. The performance of buried pipelines in areas subjected to ground displacements constitute a criterion for design, assessment and management of gas pipelines, to ensure public, environment and property safety in a cost-effective manner. Modern surveying and sampling techniques allow for better geotechnical characterization of ground movements and the variability of the soil properties with confidence. The statistical data …

Guidelines For Designing The Overhead Transmission Tower Foundations Adjacent To Cohesionless Slopes, Meshel Q. Alkahtani

Electronic Thesis and Dissertation Repository

Foundations supporting electrical transmission line towers are subjected to oblique loading due to tower own weight along with wind loading. Due to land limitation and linear alignment of transmission lines, many power transmission towers are situated in sand near sloping grounds and proper evaluation of their foundation performance is essential for the safety and reliability of the critical power transmission lines. There is currently no guidance available on the behaviour of transmission towers foundations constructed near slopes. Thus, the primary objectives of this study are to evaluate the response of transmission tower foundations in cohesionless sloping grounds and investigate the …

Exploring The Perspectives Of Older Adults And Health Care Providers On Patient Participation In Transitional Care From Hospital To Cardiac Rehabilitation During The Covid-19 Pandemic, Cecilia Flores Sandoval

Electronic Thesis and Dissertation Repository

Older adults who transition from hospital to cardiac rehabilitation settings often are vulnerable and at risk of experiencing adverse health care outcomes. Given the complexities of transitional care, it is crucial to engage older adults in the clinical decision-making process and to promote their active participation in their medical care. Older adults have unique ways of understanding their participation in the transitional care process. Gaining an in-depth understanding of their specific needs during this process can help inform clinical practice and interventions aiming to improve care for older adults living with cardiovascular disease. Focused ethnography methodology was used to explore …

The Development, Short-Term Efficacy, And Pilot Implementation Of An E-Learning Course In Physical Activity And Sedentary Behaviour For Pre-Service Early Childhood Educators, Brianne Bruijns

Electronic Thesis and Dissertation Repository

The overarching purpose of this dissertation was to develop an e-Learning course in physical activity and sedentary behaviour and test its short-term efficacy and implementation among pre- and in-service early childhood educators (ECEs). The Delphi approach was adopted for Study 1, wherein a panel of international experts in physical activity and sedentary behaviour suggested topics for the course and, together with a panel of ECE experts, rated their importance. Study 2 employed a pre-post design to explore the changes in pre- and in-service ECEs’ physical activity and sedentary behaviour-related knowledge, self-efficacy, behavioural intention, and perceived behavioural control following course completion. …

Understanding The Lived Experience Of Health Through The Exploration Of Well-Being Of Women With Multiple Sclerosis In Southwestern Ontario, Jennifer Howard

Electronic Thesis and Dissertation Repository

The prevalence of Multiple Sclerosis (MS) is increasing globally with 2.8 million cases worldwide as of 2021, with Canada experiencing the highest incidence for this disease (Multiple Sclerosis International Foundation [MSIF], 2021; Multiple Sclerosis Society of Canada [MSSC], 2021). MS is an autoimmune disease that damages the myelin sheath in the central nervous system (spinal cord and brain) which may result in problematic symptoms such as cognitive dysfunction and lead to physical disability (MSSC, 2021). There are over 90,000 Canadians with MS, impacting women on a ratio of 3:1 compared to men (MSSC, 2021; Statistics Canada, 2013). Current literature suggests …

Femoroacetabular Impingement Syndrome: Evaluating Postoperative Rehabilitation Progress And Return To Sport Readiness, Trevor A. Day

Electronic Thesis and Dissertation Repository

Femoroacetabular impingement syndrome (FAIS) is a common cause of non-arthritic hip pain and reduced physical activity in active young adults. It is defined as a motion-related disorder of the hip with a triad of symptoms, clinical signs, and imaging findings that represents symptomatic premature contact between the proximal femur and the acetabulum. There are two anatomical morphologies that can cause FAIS, cam, and pincer, and is a challenging clinical pathology. Patients typically undergo hip arthroscopy to repair damage to the joint and recess the bone causing the impingement. These procedures can result in positive outcomes for the patient, like reduced …