Engineering Commons^™

Design, Implementation And Evaluation Of A Redundancy Management System For Fault-Tolerant Wireless Devices In Harsh Environments, Madison Mccarthy

Electronic Thesis and Dissertation Repository

Wireless sensor networks (WSNs), when deployed in harsh environments, can fail prematurely due to elevated rates of component failures. To counteract this problem, fault-tolerant techniques, such as redundancy, may be used. A redundant design requires a management system. Built-in tests (BITs) are one of the most commonly used approaches for managing redundancy, but it suffers from issues such as imperfect fault coverage and common-cause failures (CCFs). In this work, a BIT based redundancy management system has been designed that makes use of a supervisory unit and a modular architecture to address issues with imperfect fault coverage and CCFs. The design …

Synthesis Of Chemically Stable Vo2 Particles Using Green Solvents And Their Application As Smart Coatings, Dicho Zomaya

Electronic Thesis and Dissertation Repository

Heating and cooling buildings consumes a tremendous amount of energy worldwide, often >50% for Northern climates such as Canada. A major part of this energy is lost through windows. The use of thermochromic windows provides a new intriguing option, in which the window automatically regulates the amount of solar transmission in response to environmental temperature changes. Of the potential thermochromic materials, vanadium dioxide (VO₂) is known to display a fully reversible semiconductor-metal transition (SMT). VO₂ responds thermochromically to environmental temperature changes by changing its crystal structure as a function of temperature. VO₂ is transparent to infrared …

Tissue Equivalent Gellan Gum Gel Materials For Clinical Mri And Radiation Dosimetry, Pawel Brzozowski

Electronic Thesis and Dissertation Repository

Hydrogels contain high amount of water allowing their use as surrogates to human tissues with specific properties that can be tuned by additives. Gellan gum is a gel-forming material of interest and is a replacement for other common gelling agent with limited use as a tissue phantom. Therefore, this thesis examines the application of gellan gum gels as a novel magnetic resonance imaging (MRI) phantom with a design of experiments model to obtain tunable properties. The analysis was extended to include mechanical and electrical properties with a separate design of experiment. Gels doped with synthesized superparamagnetic iron oxide nanoparticles (SPIONs) …

Design Of Tissue-Specific Cellular Microenvironments For Adipose-Derived Stromal Cell Culture And Delivery, Arthi Shridhar

Electronic Thesis and Dissertation Repository

The development of in vitro cell culture models that investigate tissue-specific effects of the extracellular matrix (ECM) on stem/progenitor cell lineage-commitment can contribute towards the design of improved cell delivery strategies. This thesis developed processing methods that conserved ECM bioactivity to generate well-characterized 2- and 3-D culture platforms that facilitated the evaluation of ECM composition on the adipogenic and osteogenic differentiation of human adipose-derived stromal cells (ASCs). Initial work compared α-amylase and pepsin digestion as methods to fabricate ECM coatings. The effects of enzyme processing and ECM composition were explored using human decellularized adipose tissue (DAT) and bovine tendon collagen …

Development And Assessment Of Signal Processing Algorithms For Assistive Hearing Devices, Farid Moshgelani

Electronic Thesis and Dissertation Repository

Speech identification in the presence of background noise is difficult for children with auditory processing disorder and adults with sensorineural hearing loss. The listening difficulty arises from deficits in their temporal, spectral, binaural, and/ or cognitive processing. Given the lack of improvement with conventional assistive hearing devices, alternate speech processing methodologies, which exaggerate the temporal and spectral cues, need to be developed to improve speech intelligibility for individuals who have poor temporal and/ or spectral processing.

This thesis first, reports results from a series of experiments on subjective and objective assessments of two different schemes of envelope enhancement algorithms (dynamic …

Microwave And Ultrasonic Assisted Synthesis Of Zeolites From Coal Fly Ash In Batch And Circulating Batch Operation, Tahani Hassn Aldahri

Electronic Thesis and Dissertation Repository

This research was focused on the production of zeolites from CFA throughutilizing ultrasound and microwave power. The initial conventional heating process of 6 h prior to microwave irradiation for samples with high solid-to-liquid (S/L) ratio (CFA mass/ NaOH solution volume) led to a higher yield of zeolite and decreased the synthesis time and consumption of energy,while keeping the high quality of the synthesized zeolite intact. The crystal growth of the nuclei generated over 6 h of conventional hydrothermal treatment was enhanced by the post-microwave heating. Ultrasound-assisted zeolitizationCFA was also applied in this research.

When ultrasound energy was applied after hydrothermal …

Non-Classical Nucleation Phenomena Study And Following Process Monitoring And Optimization In Solution Crystallization Process, Zhenguo Gao

Electronic Thesis and Dissertation Repository

Nucleation is a crucial step in the solution crystallization process. Despite their good development, classical nucleation theory and two-step nucleation theory cannot explain all the nucleation phenomena, especially for the non-classical nucleation phenomena which include oiling out, gelation and non-monotonic nucleation. Accordingly, for the non-classical nucleation systems, the crystallization processes are seldom designed based on the nucleation monitoring and supervision. In this thesis, crystallization process optimization was conducted to study the mechanism of non-classical nucleation phenomena and in-line process monitoring technology development.

Two kinds of non-classical nucleation phenomena with non-monotonic nucleation rate and gel formation were investigated, and accordingly, two …

Improving Material Mapping In Glenohumeral Finite Element Models: A Multi-Level Evaluation, Nikolas K. Knowles

Electronic Thesis and Dissertation Repository

An improved understanding of glenohumeral bone mechanics can be elucidated using computational models derived from computed tomography data. Although computational tools, such as finite element analysis, provide a powerful quantitative technique to evaluate and answer a variety of biomechanical and clinical questions, glenohumeral finite element models (FEMs) have not kept pace with improvements in modeling techniques or model validation methods seen in other anatomic locations. The present work describes the use of multi-level computational modeling to compare, develop and validate FEMs of the glenohumeral joint.

Common density-modulus relationships within the literature were evaluated using a multi-level comparative testing methodology to …

Investigation And Modeling Of The Dip Coating For Dispersions With Near Wall Effects, Mahdieh Moghadasi

Electronic Thesis and Dissertation Repository

The key to controlling the quality of liquid dispersion coated films lies in the particle distribution in the flow field. The control of particle dispersion in the film can also empower the optimization of the process operation. Therefore, a numerical simulation of a solid-liquid suspension in the dip coating (free withdrawal) process using the finite element method for the fluid flow has been developed. The neutrally buoyant suspension is considered as a Newtonian fluid with a concentration-dependent viscosity. A continuum constitutive equation is employed based on the diffusive flux model in twodimensional flow. The main purpose of this study is …

Advances In Design Methodology In Swelling Shale Rock In Southern Ontario, Thomas R.A. Lardner

Electronic Thesis and Dissertation Repository

As infrastructure requirements increase in southern Ontario, excavations within swelling rock formations will become more frequent and larger. The objective of this study is to advance design capability for structures in swelling rock through three aspects: i) developing a practical swelling model for design engineers, ii) investigate two crushable/compressible materials for the mitigation of swelling rock effects, and iii) observe and analyze the behaviour of swelling rock to current excavation techniques.

A swelling rock constitutive model has been developed. The swelling parameters include the horizontal and vertical free swell potential, threshold stress, and critical stress as well as a “pseudo-Poisson’s …

Estimation Of Nutrient Loads From Septic Systems To Tributaries In The Lake Erie Basin, Lauren Oldfield

Electronic Thesis and Dissertation Repository

Septic systems are often cited as an important source of nutrient loading to surface waters; however, there is limited quantitative evidence supporting this. To address phosphorus (P) load reduction targets for Lake Erie that were set by the Canadian and United States governments, there is a need to quantify the contribution of septic systems to P tributary loads. Doing so is challenging due to the diffuse nature of this nonpoint source, the lack of septic system inventory across Ontario, and the complexity of P transport in the environment. In this study, the artificial sweetener acesulfame, a tracer for human wastewater, …

Full-Scale Measurements To Evaluate Single-Ply Metal Roof Performance Under Extreme Wind Loads, Mahshid Nasiri

Electronic Thesis and Dissertation Repository

This study focused on assessing the performance of single-ply metal roofing system under high wind loads. Full-scale measurements were conducted at Insurance Research Lab for Better Homes at the University of Western Ontario, on a full-scale standing seam metal roof (SSMR) system in order to investigate the load sharing among the clip fasteners. A pressure loading approach was used for applying pressure distributions with spatial and time variation on the roof system as the induced loads on the clips were measured using installed load cells. The influence functions of clip reactions were measured. It was observed that the area of …

Additive Manufacturing Of Piezoelectric Photopolymer Ferroelectrets, Rami Abu Shammeh

Electronic Thesis and Dissertation Repository

Electroactive polymers are an emerging branch of smart materials that possess the capability to change shape in the presence of an electric field. Particularly, ferroelectrets are films of electrostatically charged dielectric polymer foam that comprise a growing portion of EAP literature. Ferroelectrets are characterized by a piezoelectric response and a quasi-permanent charge polarization owing to the dipoles created when the air cavities in the polymer matrix undergo dielectric breakdown. However, these cavities are often irregular in shape, size, and distribution when produced with conventional preparation methods. To overcome this, we employ a light-based additive manufacturing technique to create a hybrid …

The Effect Of Scale On Spray Nozzle Performance, Aaron M. Joness

Electronic Thesis and Dissertation Repository

In the petroleum industry, Fluid Coker^TM are used to upgrade the heaviest remains of heavy oil into useful lighter products such as fuel oil or petrochemical feed. The development of a better injection into a Fluid Coker^TM is a key parameter to obtain a more efficient and sustainable use of heavy crude oil. The main detrimental factor in Fluid Coking^TM is the formation of agglomerates between the injected oil and the coke particles. These agglomerates not only trap injected oil, not allowing free reaction, but also cause harm to the Coker^TM when they fall to the …

Analysis And Control Of Aluminum Concentration In Groundwater: Mathematical Modelling And Laboratory Study, Daria Popugaeva

Electronic Thesis and Dissertation Repository

The remediation of metal-contaminated natural water bodies is prioritized due to metals toxicity, non-biodegradable properties, and accumulative behaviours leading to the increased incidence of adverse health effects. Current investigation is driven by the existing problem of elevated aluminum concentrations in the groundwater of Khibiny alkaline massif (Kola Peninsula). The prohibitive aluminum level exceeding the accepted standard of 0.20 mg L⁻¹ is described as a serious health concern when the groundwater used for the local water supply. The results of comprehensive field data analysis based on chemometric methods applied to the available monitoring data including 12 groundwater quality parameters are …

Investigation Of Radiation-Hardened Design Of Electronic Systems With Applications To Post-Accident Monitoring For Nuclear Power Plants, Qiang Huang

Electronic Thesis and Dissertation Repository

This research aims at improving the robustness of electronic systems used-in high level radiation environments by combining with radiation-hardened (rad-hardened) design and fault-tolerant techniques based on commercial off-the-shelf (COTS) components. A specific of the research is to use such systems for wireless post-accident monitoring in nuclear power plants (NPPs). More specifically, the following methods and systems are developed and investigated to accomplish expected research objectives: analysis of radiation responses, design of a radiation-tolerant system, implementation of a wireless post-accident monitoring system for NPPs, performance evaluation without repeat physical tests, and experimental validation in a radiation environment.

A method is developed …

Development Of In Situ Forming Hydrogels For Intra-Articular Drug Delivery, Andy Prince

Electronic Thesis and Dissertation Repository

Hydrogels are 3-dimensional crosslinked polymer networks that can absorb significant amounts of water. The physical properties associated with hydrogels affords them resemblance to biological tissues making them good candidates for biomedical applications. Many pharmaceuticals, specifically non-steroidal anti-inflammatory drugs (NSAIDs), have poor aqueous solubility, which limits their bioavailability and efficacy. People suffering from chronic osteoarthritis (OA) are required to frequently take large doses to mitigate pain, which can lead to serious side effects. Hydrogels are good strategies to deliver NSAIDs via articular injection because they can form solid gels in situ. This thesis describes the synthesis, formulation, mechanical testing, in …

Autonomous And Real Time Rock Image Classification Using Convolutional Neural Networks, Alexis David Pascual

Electronic Thesis and Dissertation Repository

Autonomous image recognition has numerous potential applications in the field of planetary science and geology. For instance, having the ability to classify images of rocks would allow geologists to have immediate feedback without having to bring back samples to the laboratory. Also, planetary rovers could classify rocks in remote places and even in other planets without needing human intervention. In 2017, Shu et. al. used a Support Vector Machine (SVM) classification algorithm to classify 9 different types of rock images using a with the image features extracted autonomously. Through this method, they achieved a test accuracy of 96.71%. Within the …

A Network Approach To Interdependent Infrastructure Resilience Assessment For Natural Hazards, Howard Tong

Electronic Thesis and Dissertation Repository

Natural disasters are increasingly costly to society as they disrupt basic infrastructure functions. Infrastructure managers face challenges from growing urbanization, climate change, and aging infrastructure. Infrastructure resilience is an emerging concept that has been suggested as a solution to this problem; however, it is not yet mature. This thesis proposes to extend an existing dynamic infrastructure resilience quantification methodology to include infrastructure growth capabilities while relaxing some of the original constraints. The methodology uses a complex networks approach to model infrastructure interdependencies that is applied to a case study in the City of Toronto using a newly developed web tool.

Bouncing Dynamics Of A Class Of Mem/Nem Switching Systems, Mohamed Bognash

Electronic Thesis and Dissertation Repository

The aim of the present research is to understand the bouncing dynamic behavior of NEM/MEM switches in order to improve the switch performance and reliability. It is well known that the bouncing can dramatically degrade the switch performance and life; hence, in the present study, bouncing dynamics of a cantilever-based NME/MEM switch has been studied in detail. To this end, a model of a MEM switch that incorporates electrostatic force, squeeze film air damping force as well as asperity-based contact force has been proposed for an electrostatically actuated switch. An actuation force due to piezoelectric effects is further included in …

Heat Of Hydration Thermal Performance And Flexural Capacity Of Stainless-Steel Reinforced Concrete Sections, Mokhtar Khalifa

Electronic Thesis and Dissertation Repository

Stainless steel (SS) is increasingly used in the construction field due to its high strength and corrosion resistance. However, its coefficient of thermal expansion is different from that of concrete. This difference raises concerns about the potential for concrete cracking during the hydration process. To address this concern, a thermal-structural finite element model was developed to predict the stresses in SS reinforced concrete (RC) sections during the hydration process. Different curing regimes were taken into consideration. The analysis was performed in two stages. First, a transient thermal analysis was performed to determine the temperature distribution within the concrete section as …

Apply Dry Powder On Drug Loading And Enteric Coating Of Esomeprazole Magnesium Trihydrate Beads And Capsules, Xiaojing Ge

Electronic Thesis and Dissertation Repository

Esomeprazole magnesium tri-hydrate (EMT) is a proton pump inhibitor, used for the treatment of gastric and duodenum ulcers. It is currently the best choice for the treatment of acid-related diseases, but it is extremely unstable in gastric acid and sensitive to wet, heat, light. It also will react with the enteric coating material used in this study. So enteric coating and sub coating is needed.

This study offers a new approach, dry powder coating technology, to achieve drug loading and enteric coating of EMT beads and capsules. Dry powder coating, a new type of solvent-less coating technology, can address most …