Engineering Commons^™

Realtime Implementation Of An Internal-Model-Principle Signal Identifier, Edris Saleh Mohsen

Electronic Thesis and Dissertation Repository

This thesis presents a new means approach of tuning an adaptive internal model principle based signal identification algorithm whose computational costs are low enough to allow a realtime implementation. The algorithm allows an instantaneous Fourier decomposition of nonstationary signals that have a strongly predictable component. The algorithm is implemented as a feedback loop resulting in a closed loop system with a frequency response of a bandpass filter with notches at the frequencies of the Fourier decomposition. This is achieved through real time selection of the coefficients of the transfer functions in the feedback loop. Previous work showed how the dynamics …

Efficiency And Accuracy Enhancement Of Intrusion Detection System Using Feature Selection And Cross-Layer Mechanism, Mahsa Bataghva

Electronic Thesis and Dissertation Repository

The dramatic increase in the number of connected devices and the significant growth of the network traffic data have led to many security vulnerabilities and cyber-attacks. Hence, developing new methods to secure the network infrastructure and protect data from malicious and unauthorized access becomes a vital aspect of communication network design. Intrusion Detection Systems (IDSs), as common widely used security techniques, are critical to detect network attacks and unauthorized network access and thus minimize further cyber-attack damages. However, there are a number of weaknesses that need to be addressed to make reliable IDS for real-world applications. One of the fundamental …

Functional Design And Analysis Of A Linked Shoulder Prosthesis, Emily West

Electronic Thesis and Dissertation Repository

Persistent shoulder instability following joint arthroplasty remains a concern with mixed outcomes following clinical and surgical intervention. Thus, a linked universal joint implant was developed and functionally analyzed. A virtual model of the linked implant was developed and implanted in a 3D bony specimen to measure the available circumduction range of motion. Stresses in the implant were estimated using finite element analysis based on joint loads during activities of daily life. The glenoid fixation stress was evaluated using finite element analysis.

The implant was capable of restoring normal range of motion, and withstanding expected joint loads without yield or fatigue …

Novel Night And Day Control Of A Pv Solar System As A Statcom (Pv-Statcom) For Damping Of Power Oscillations, Hesamaldin Maleki

Electronic Thesis and Dissertation Repository

Installations of large scale PV solar farms are rapidly increasing, worldwide. This is causing a growing apprehension that inertialess power injections from these inverter based generators will result in a decline in power system stability. Instead, this thesis presents novel applications of a patent pending technology whereby the PV solar farms actually help significantly increase system stability. A novel 24/7 (night and day) control of a large-scale PV solar farm as a dynamic reactive power compensator STATCOM, termed PV-STATCOM, is presented for damping low-frequency electromechanical power oscillations resulting in a significant improvement in power transfer capability of existing power transmission …

Bi-Directional Cyclic Behaviour And Liquefaction Analysis Of A Silica-Carbonate Sand, Keyvan Mirbaha

Electronic Thesis and Dissertation Repository

The cyclic behavior and liquefaction behavior of reconstituted samples of a local silica-carbonate sand are examined by performing monotonic and cyclic simple shear tests in addition to bender element shear wave velocity measurements. Shear wave velocity was found to vary with effective overburden stresses by an average power of 0.25. Maximum shear modulus (G_max) was also computed from the shear wave velocity measurements and a correlation was developed between G_max, effective stress and void ratio. Small strain and cyclic strain dependent shear modulus of the soil were determined, and shear modulus reduction curves were obtained. The …

Development Of Nanomaterials For Lithium-Ion Batteries By Atomic Layer Deposition, Biqiong Wang

Electronic Thesis and Dissertation Repository

Lithium ion batteries (LIBs) have been the dominant candidate in the field of energy storage. The ever-growing demand of high energy and power density, longer battery life, and more assured safety level has geared the development of LIBs towards all-solid-state batteries (ASSBs). The solid-state nature allows more flexibility in battery design and higher area capacity to be obtained within limited space. Moreover, replacing liquid electrolytes with solid-state electrolytes (SSEs) is a most effective approach to achieve safer battery system. In addition, ASSBs hold great promise in the actual fabrication of microbatteries for microelectronics. Therefore, a technique which can synthesize materials …

Comparison Of Dc Motors And Dielectric Elastomer Actuators For Wearable Wrist Exoskeletons, Myles Lidka

Electronic Thesis and Dissertation Repository

Paralysis or loss of strength resulting from stroke requires patients to undergo extensive rehabilitation therapy. It is known that intensive therapy contributes significantly to recovery, but as the number of surviving stroke patients increases, it is difficult for clinics to provide patients with the optimal level of therapy. Robotic devices for wrist rehabilitation have been developed to lessen these problems, but at the moment they are physically large and must be used within a clinical setting. More benefit could be obtained if the devices were portable, so that they could be used by the patients on a daily basis. To …

Seismic Performance Of Steel Helical Piles, Moustafa K. El-Sawy

Electronic Thesis and Dissertation Repository

Recent earthquakes have highlighted the need for safe and efficient construction of earthquake resilient structures. Meanwhile, helical piles are gaining popularity as a foundation for new structures and retrofitting solution for existing deficient foundations due to their immense advantages over conventional driven pile alternatives. In addition, helical pile foundations performed well in recent earthquakes, proving they can be a suitable foundation option in seismic regions. The objective of this thesis is to evaluate the seismic performance of helical piles by conducting full-scale shaking table tests and nonlinear three-dimensional numerical modeling using the computer program ABAQUS/Standard. The experimental setup involved installing …

Advanced Materials For Lithium Ion Batteries:Surface And Interface Chemistry, Yulong Liu

Electronic Thesis and Dissertation Repository

Lithium ion batteries (LIBs) are the indispensable energy storage devices in our modern society. LiFePO₄, as one of the most promising cathode, are widely used in LIBs. However, impurity phases are formed in LiFePO₄ during carbon coating process due to the intrinsic strong reducing atmosphere. Herein, as the first part of my work, interface chemistry of carbon coating on LiFePO₄ are symmetrically investigated by advanced characterization techniques. Two distinct secondary phases are formed during carbon coating process at different condition. Moreover, secondary phase formation is controllable by changing the particle size of LiFePO₄, annealing …

Modeling Of Force And Motion Transmission In Tendon-Driven Surgical Robots, Farshad Anooshahpour

Electronic Thesis and Dissertation Repository

Tendon-based transmission is a common approach for transferring motion and forces in surgical robots. In spite of design simplicity and compactness that comes with the tendon drives, there exists a number of issues associated with the tendon-based transmission. In particular, the elasticity of the tendons and the frictional interaction between the tendon and the routing result in substantially nonlinear behavior. Also, in surgical applications, the distal joints of the robot and instruments cannot be sensorized in most cases due to technical limitations. Therefore, direct measurement of forces and use of feedback motion/force control for compensation of uncertainties in tendon-based motion …

Enumeration, Variability, And Transport Of Escherichia Coli In The Foreshore Reservoir And Surface Water At Freshwater Beaches, Laura J. Vogel

Electronic Thesis and Dissertation Repository

Beaches are of immense recreational, societal and economic value. This value, however, is considerably diminished by poor water quality. Fecal indicator bacteria (FIB) are measured at recreational beaches worldwide to assess the water quality. A beach closure or advisory is issued if FIB concentrations in surface water exceed recreational water quality standards. Due to the lengthy time required to enumerate FIB (24 – 96 hours), statistical and mechanistic models have been developed to predict water quality exceedances a priori and to better understand why and under what conditions water quality exceedances occur. These models as well as beach water quality …

Metal Sulfides As Anode For Lithium Ion And Sodium Ion Battery, Ali Abdulla

Electronic Thesis and Dissertation Repository

Abstract

Nanomaterials have been studied intensively in the last decades due to their unique physical and chemical properties and their potential for applications in different domains. Among these applications, energy storage has become the center of focus by many research groups and companies to develop high efficiency and reliable energy devices such as the commercial lithium ion batteries (LIBs). However, LIBs has not yet met the growing requirements of the high demand for increasing energy density. More efforts are requested to improve the performance of the batteries by designing better electrode materials and increasing the battery safety. Another type of …

Development Of High-Performance Carbon And Phosphorus Anode Materials For Sodium-Ion Batteries, Wei Xiao

Electronic Thesis and Dissertation Repository

Abstract

Lithium-ion batteries, as dominant power sources for prevailing consumer electronics and electric vehicles, have been plagued by limited lithium resources with the soaring prices. Sodium-ion batteries, benefitted from ubiquitous and inexpensive sodium resources without toxicity and pollution, have emerged as promising alternatives for large-scale applications. Considering their kinetic challenges and disadvantageous energy densities, it is urgently necessary to pursue high-performance electrode materials to remedy these intrinsic defects. For anode materials, the primary choices of sodium metal and graphite are correspondingly denied for safety issues and intercalation incapability. Therefore, the objective for this doctoral work is to develop high-performance anode …

A Patient-Specific Cardiac Phantom For Training And Pre-Procedure Surgical Planning, Justin Laing

Electronic Thesis and Dissertation Repository

Minimally invasive cardiac procedures requiring a transseptal puncture are becoming increasingly common. For cases of complex or diseased anatomy, clinicians may benefit from using a patient-specific cardiac phantom for training, surgical planning, and the validation of devices or techniques.

An imaging compatible cardiac phantom was developed to simulate a MitraClip ® procedure. The phantom contained a patient-specific cardiac model manufactured using tissue mimicking materials.

To evaluate accuracy, the patient-specific model was imaged using CT, segmented, and the resulting point cloud data set was compared using absolute distance to the original patient data. The phantom was validated using a MitraClip ® …

Influence Of Scapular Notching On Contact Mechanics And Simulator Wear Of Reverse Total Shoulder Arthroplasty Implants, Michael William Griffiths

Electronic Thesis and Dissertation Repository

Scapular notching is a common complication of reverse total shoulder arthroplasty (RTSA) wherein the predominant focus of current literature has been on changes in osseous anatomy. However, the implications on RTSA performance from the damaged humeral cup is largely unknown. Therefore the present work describes the effects of the initiation and propagation of the humeral cup defect resulting from scapular notching through the use of finite element modeling and wear simulation, in order to assess changes in RTSA contact mechanics and tribological properties. A significant decrease in articular contact area and increase in maximum contact stress values was found for …

Surface Topography Formation And Thermographic Analysis In Laser Polishing Of H13 Tool Steel, Joshua D. Miller

Electronic Thesis and Dissertation Repository

Laser polishing, in its simplest form, is the melting of a small layer of material via laser radiation. This creates a small molten pool which is re-distrusted across the surface, resulting in a much smoother finished surface. Although this process has been around for decades now, there has been a recent insurgence into industrial applications. Despite this, the phenomena that occur during the process are still not fully understood. Therefore, increasing the knowledge surrounding the process would be ideal.

To accomplish this, various input parameters of the process are altered to analyze the effect on the finished polished surface. Through …

Influence Of Turbulence On The Aerodynamics Of Low-Rise Buildings, Fakhruzzaman Arif

Electronic Thesis and Dissertation Repository

During extreme wind events, roofing failures may lead to damage of the whole structure. In order to alleviate the effect, surface pressure coefficients on the roofs have been extensively investigated. This research aims to determine the roof pressures acting on low-rise buildings with consideration of the effects of turbulence (terrain). Pressure measurements, as well as wind speed data, were taken at the Boundary Layer Wind Tunnel Laboratory (BLWTL) of the University of Western Ontario (UWO) to examine the influence of turbulence level (i.e., terrain condition) on the critical wind directions corresponding to the largest surface roof pressure coefficients for various …

Generic Numerical Tornado Model For Common Interpretation Of Existing Experimental Simulators, Anant Gairola

Electronic Thesis and Dissertation Repository

There are difficulties in making a common interpretation of results of similar experiments done in different experimental tornado simulation facilities. This is primarily because of the differences in vortex generation mechanisms utilized as well as geometric differences in these facilities. Therefore, in an attempt to facilitate a universal interpretation of results, a generic numerical tornado model, representing the three major existing experimental tornado simulators, is developed in this study. The three experimental simulators in consideration are VorTECH at Texas Tech University, Tornado Simulator at Iowa State University and WindEEE Dome at Western University as representatives of “Ward” type, “top-down” type …

The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet

Electronic Thesis and Dissertation Repository

The motivation of this thesis is the development of simple microscopic-scale model (representative elemental volume; REV) that can be used to conduct flow and heat transfer simulations from which closure coefficients can be established for the volume-averaged transport equations for porous media (packed bed). The thesis provides a brief introduction to the computational technique adopted for the geometric generation of the REV (YADE), followed by a parametric study undertaken to reveal the minimum number of particles inside the REV that are required to mimic the appropriate physics. Additional analysis was conducted with the goal of determining the influence of deviation …

3d Printing Of Functional Materials: Surface Technology And Structural Optimization, Dongxing Zhang

Electronic Thesis and Dissertation Repository

There has been a surge in interest of 3D printing technology in the recent 5 years with respect to the equipment and materials, because this technology allows one to create sophisticated and customized parts in a manner that is more efficient regarding both material and time consumption. However, 3D printing has not yet become a mainstream technology within the established manufacturing routes. One primary factor accounting for this slow progress is the lack of a broad variety of 3D printable materials, resulting in limited functions of 3D printed parts.

To bridge this gap, I present an integrated strategy to fabricate …

Numerical Simulations Of Two-Phase Flows In The Liquid Solid Circulating Fluidized Bed, Hao Luo

Electronic Thesis and Dissertation Repository

The liquid-solid circulating fluidized bed (LSCFB) has many potential applications in biochemical and petroleum industries, as well as in wastewater treatments, given its higher contact efficiency and being able to accommodate two reactions under one system. With extensive experimental results becoming available, there is clearly a need for computational fluid dynamics (CFD) modeling to expand our understandings of LSCFBs and to predict the hydrodynamic behaviors of the two-phase flows within LSCFB.

In this research, the Eulerian-Eulerian two-phase model combined with the kinetic theory for the granular phase is applied to simulate the two-phase flows in LSCFBs. The key factors affecting …

Time-Lapse Electrical Resistivity Tomography For Mapping In Situ Smouldering Remediation (Star), Lais Muchatte Trento

Electronic Thesis and Dissertation Repository

Time-lapse Electrical Resistivity Tomography (ERT), a surface geophysical technique, was applied for the first time to monitor the first full-scale application of Self-sustaining Treatment for Active Remediation (STAR) at a coal tar contaminated site. STAR is a self-sustaining smouldering technology that destroys contaminants in situ by combustion, generating heat, water, and combustion gases. ERT is used as a complementary source of information to support conventional temperature and gas concentration data collected during STAR operations. A shallow (2.4 mbgs) and a deep (7.8 mbgs) treatment cell were monitored, with 2D surface resistivity surveys conducted before, during and after treatment. Two 36 …

Experimental Measurements Of Far Field Cough Airflows Produced By Healthy And Influenza- Infected Human Subjects, Ahmed Faraj Alarbi Mohamed

Electronic Thesis and Dissertation Repository

The present work details an experimental study of the cough airflow fields produced by subjects infected with influenza and when they are convalescent, together with data from healthy cohorts. The PIV and HWA measurements were taken far downstream at 1 m from the source within a cough chamber, along with droplet sampling at two different locations and nasal swabs from the sick subjects. The measured data over different seasons were used to evaluate and compare the results from sick, convalescent and healthy subjects. Although a total of 8 sick participants from winter 2014 and 2017 yielded positive nasal swab analysis, …

The Onset Of Convection In Rarefied Gases, Md Asif Zobaer

Electronic Thesis and Dissertation Repository

The onset of convection in the Rayleigh-Bénard problem for a monatomic rarefied gas at small Knudsen number has been investigated. Compressibility-induced density variations have been considered without imposing any restriction on the magnitude of temperature difference. A linear temporal stability analysis has been conducted for a compressible slip-flow model considering a Maxwellian gas and the dispersion relation is calculated using a Chebyshev collocation method. A neutral stability curve obtained in the Froude-Knudsen number plane marks transition to convection from a pure conduction state. The critical wave number observed for the onset of convection is in good agreement with the existing …

A Study On Hydraulic Conductivity Of Fine Oil Sand Tailings, Mingyue Liu

Electronic Thesis and Dissertation Repository

In oil sand waste tailings pond, the gravity segregation takes place, where coarse particles settle relatively more quickly than fine particles, and a stable suspension, known as the mature fine tailings (MFT), is formed. Compression of MFT appears to be very slow, and MFT remains suspended in tailings pond for decades due to the low permeability. Large volumes of MFT continually accumulate in tailings ponds, and therefore MFT storage requires a large containment pond, which generates environmental concerns and leads to MFT management challenges. Hydraulic conductivity is one of the most important properties of MFT because it controls consolidation behaviors. …

A Biomechanical Investigation Of Load Sharing At The Distal Forearm, Martine E. Mcgregor

Electronic Thesis and Dissertation Repository

Loading at the distal forearm has been previously examined under static loads, however there remains no consensus on how loading is affected by active wrist and forearm motion. This work examines load magnitudes and load sharing at the distal radius and ulna during of active wrist and forearm motion. Two instrumented implants were designed to measure in vitro loading in cadaveric specimen. The implants were evaluated and found reliable for use in further biomechanical studies. An in vitro study investigated the effect of joint angle and direction of joint motion on loads in the distal radius and ulna during active …

Analysis Of Framing Failures In Wood-Frame Residential Roofs Under Wind Load, Sarah A. Stevenson

Electronic Thesis and Dissertation Repository

Wood-frame residential roof failures are among the most common and expensive types of tornado damage. Hip roofs are commonly understood to be more resilient during extreme wind in relation to gable roofs. However, inspection of damage survey data from recent tornadoes has revealed a previously unstudied failure mode in which hip roofs suffer partial failure of the framing structure. This research focuses on proving the concept of framing failures in hip roofs. Evidence of partial framing failures and statistics of their occurrence are explored and discussed, and common roof design and construction practice is reviewed. Two-dimensional finite element models are …

Pressure Equalization Of Wind-Induced Pressures On Residential Vinyl Siding Cladding In Full-Scale, Randy A. Van Straaten

Electronic Thesis and Dissertation Repository

Residential vinyl siding cladding system failures have been observed in high wind events. North American vinyl siding design standards allow a 64% pressure equalization factor, which yield relatively low wind load resistance for these products. The allowance is based on testing, which is questioned based on the literature review. The modified discharge equation analytical model, developed by others, accurately predict extent of pressure equalization found in scaled wind tunnel measurements. The model provides value in informing testing standards, product design and forensic investigations. However, it has only been validated based on scaled wind tunnel testing which may present scaling effect …

Estimation Of Turbulence Effects On Wind-Induced Suctions On The Roof Of A Low-Rise Building, Chieh-Hsun Wu

Electronic Thesis and Dissertation Repository

The effects of turbulence in the atmospheric boundary layer (ABL) on surface pressures of a typical low-rise building roof are investigated in this thesis. A 1/50 geometrically-scaled model of the Texas Tech University Wind Engineering Field Research Lab (WERFL) building model is used for pressure measurements in wind tunnel experiments. ABL wind turbulence intensities ranging from about 10% to 30%, and length scales ranging from 6 to 12 times of the building height (H) are generated. The effects of ABL turbulence on the mean roof pressures within the separated flow are explained from the time-averaged Navier-Stokes equations. The pressure fields …

Static And Dynamic Properties Of Controlled Low-Strength Materials Incorporating Treated Oil Sands Waste, Ahmed Mneina

Electronic Thesis and Dissertation Repository

Controlled Low-Strength Materials (CLSM) is a self-compacted self-leveling cementitious material with compressive strength of 8.3 MPa or less. It is used as an alternative of soil backfill materials in geotechnical and infrastructure applications. This study investigates the effects of incorporating treated oil sand wastes (TOSW) as a partial replacement of sand or fly ash on fresh and hardened properties of CLSM. In addition, the environmental impact of the proposed new mixtures was evaluated. The results show that CLSM mixtures incorporating TOSW had satisfied the limits and requirements of ACI committee 229 for CLSM with no environmental hazards. The incorporation of …