Engineering Commons^™

Synthesis Of Vo2/Poly(Mma-Co-Dmemuabr) Antimicrobial/Thermochromic Dual-Functional Coating And Reactivity Ratios Study, Yixian Liu

Electronic Thesis and Dissertation Repository

Antimicrobial/thermochromic dual-functional coatings were successfully synthesized via UV-curing. The quaternary ammonium compound (QAC) N,N-dimethyl-N-{2-[(2-methylprop-2-enoyl)oxy]ethyl}undecane-1-aminium bromide (dMEMUABr) was synthesized and copolymerized with methyl methacrylate (MMA) for antimicrobial properties. Vanadium oxide (VO₂) nanoparticles were evenly dispersed within the coating, providing thermochromic properties. The dual-functional coating showed high luminous transmittance (T_lum(25°C) =36.1 %) and solar energy modulation ( T_sol=5.8 %). 90.3 % of bacteria reduction was observed against Escherichia coli within 24 h contact. To further understand the sequence distribution of the copolymer poly(MMA-co-dMEMUABr), the reactivity ratios of MMA and dMEMUABr monomer were studied and compared under thermal …

Rotating Heater Pyrolyzer (Rhp): A New Pyrolysis Technology For Biochar Production, Ariel Porat

Electronic Thesis and Dissertation Repository

Biochar provides an effective and inexpensive carbon sequestration technology to combat climate change. It is formed through a process known as pyrolysis; where biomass is thermally decomposed in the absence of oxygen. In this study, a new pyrolysis reactor called the Rotating Heater Pyrolyzer (RHP) was designed and built for biochar production. RHP derived biochar properties were compared to biochars produced with a standard batch pyrolysis reactor (Pyrolytic Shaker Reactor (PSR)) to determine RHP performance. Using several biochar characterization techniques, the soil amendment potential of two solid anaerobic digestate feedstocks were investigated. Woodchip RHP derived biochar processed between 2-3 hrs …

Development Of Novel Solid-State Electrolytes For Sodium Ion Batteries, Fei Sun

Electronic Thesis and Dissertation Repository

Sodium ion battery is considered as a potential candidate to replace lithium ion battery. To eliminate the need for containment of the liquid electrolyte, the solid-state electrolytes attract more attention. However, solid state electrolytes are still restricted to be applied for commercialization because of the inherent low ionic conductivity and the poor mechanical properties. Therefore, my Ph.D. research is focused on developing advanced solid-state electrolytes by improving ionic conductivity and disclosing mechanisms of the electrolytes.

Firstly, a series of La substituted NASICON electrolytes are prepared to achieve high ionic conductivity of mS/cm, and the effects of La substitution concentration are …

Effect Of Ion Implantation On The Mechanical Properties Of The Grain And Grain Boundary Regions Of Inconel X750, Maisaa Nezar Tawfeeq

Electronic Thesis and Dissertation Repository

Annulus gas spacers in CANada Deuterium Uranium (CANDU) nuclear reactors are made from the heat-treated Inconel X750 Nickel-based alloy. This alloy is designed to have high strength and creep resistance at elevated temperature. Unlike other reactor designs, the CANDU reactor has a high thermal neutron fluence, which results in an enhancement of the radiation damage and the internal production of helium and hydrogen. They are thus susceptible to microstructural instability and mechanical property degradation with time. Studies of ex-service spacers have indicated that they display intergranular embrittlement and lower ultimate tensile strength compared to nonirradiated Inconel X750. The primary degradation …

Hydrodynamics Of Liquid-Solid And Three-Phase Inverse Circulating Fluidized Beds, Tian Nan

Electronic Thesis and Dissertation Repository

The hydrodynamics of inverse liquid-solid circulating fluidized bed (ILSCFB) is experimentally studied in a 5.4 m tall and 0.076 m ID column. 5 types of low density particles are investigated with different particle terminal velocities.

Solids holdup distribution is found to be uniform in a wide range of superficial liquid velocities and over 10 solid circulation rates. Average solids hold is not sensitive to particle properties. Clustering phenomenon is found to be significant affecting the slip velocity in the ILSCFB. And the cluster phenomenon is directly related to particle R_­eynolds number (R_et). Particles with little …

Bioremediation Of Refinery Desalter Effluent Using Debaryomyces Hansenii And Parachlorella Kessleri, Leila Azimian

Electronic Thesis and Dissertation Repository

Crude oil desalting operations produce an effluent stream which is challenging to treat due to its salt, heavy metal and hydrocarbon content. Consequently, desalter effluent (DE) is usually diluted into other effluent streams and sent to conventional wastewater treatment plants which may lead to upsets the plant operation.

In this study, a novel microbial approach was applied which investigated DE treatment using halotolerant yeast Debaryomyces hansenii (LAF-3 10 U) or the environmentally robust micro-algae Parachlorella kessleri strain CPCC 266. The effect of these two different approaches on both synthetic and actual DE was investigated in both batch and/or continuous mode. …

Novel Avenues Toward Controlling The Photophysical Properties Of Ultra-Small Silicon Quantum Dots, Mohammed Abdelhameed

Electronic Thesis and Dissertation Repository

Quantum dots (QDs) have attracted an increasing attention in the last decade over many conventional organic dyes. This is due to their unique optical properties including broad absorption spectra, high photostability, and size-tunable photoluminescence (PL). However, some toxicity concerns associated with traditional quantum dots have hindered their wide applicability. Interestingly, silicon quantum dots (SQDs) have been shown to be more advantageous than most of QDs thanks to their excellent biocompatibility and biodegradability, low cytotoxicity, and versatile surface functionalization capability. Thus, SQDs are promising candidates for various biological and biomedical applications such as bioimaging, biosensing, and photodynamic therapy. Unfortunately, only a …

Progress Toward Durable Icephobic Materials, Matthew J. Coady

Electronic Thesis and Dissertation Repository

Ice accumulation is a major engineering challenge in many fields including aerospace, power generation, transportation, and infrastructure. A variety of solutions are being researched to address this challenge. Perhaps the most promising method of combating ice accumulation is by applying coatings with low values of interfacial ice adhesion strength, τ_ice. Icephobic materials are those with ice adhesion below 100 kPa, and it has been shown that passive delamination can occur on surfaces with τ_ice below 20 kPa. While various low adhesion surfaces have been prepared, durability concerns pervade applications where surfaces experience repeated icing or freeze-thaw cycles, …

Airborne Topological Acoustics, Xingxing Liu

Electronic Thesis and Dissertation Repository

Advances in topological acoustics are leading to potential development for noise attenuation, ultrasonic imaging, sound manipulation, and information delivering, etc. Recently, ideas and methodologies from condensed-matter physics, such as the quantum Hall effect (QHE), the quantum spin Hall effect (QSHE), and the quantum valley Hall effect (QVHE), combined with configurations of sonic crystals and metamaterials, have been investigated in manipulating acoustic transmissions in the form of one-way edge modes and defect-immune protected acoustics. However, many related studies are still in their infancy and mostly rely on bulky, noisy, overly complicated, untunable and narrow-band-effective facilities, and so it is highly desirable …

Validation Of Rhocentralfoam For Engineering Applications Of Under-Expanded Impinging Free Jets, Peter Nielsen

Electronic Thesis and Dissertation Repository

A numerical validation study of under-expanded impinging jet is conducted using OpenFOAM, an open-source computational fluid dynamics (CFD) library. RhoCentralFoam, a density based, compressible flow solver with a two-equation shear stress transport (SST) turbulence model is used on an axisymmetric model to reduce the computation cost. Major features of the flow were compared to an experimental study by Henderson et al., with a nozzle pressure ratio (NPR) of 4.0 and nozzle to plate spacing between 1.65-4.16. Of the features measured, the Mach diamond spacing, super-sonic core, and shear layer are all accurately predicted, while the recirculation bubble in the impingement …

Modal Analysis And Analytical Modeling Of Tornado-Like Vortices, Mohammad Karami

Electronic Thesis and Dissertation Repository

Regardless of the type of vortex chamber, many tornado simulators generate flows that reveal similar flow patterns and a general agreement on the variations of the flow structures with swirl ratio (the ratio of tangential velocity to radial velocity) was achieved. However, very little is known about the underlying physics of the flow, mostly of the fluctuating one, as the previous studies have mainly focused on qualitative flow visualization and the quantitative description of the mean flow.

Herein, coherent structures in tornado-like vortices are extracted using modal decomposition techniques. Modal analysis helps us to better understand the complex vortex dynamics …

A Framework For Evaluating Cortical Architectural Anomalies In Temporal Lobe Epilepsy Patients, Hossein Rajali

Electronic Thesis and Dissertation Repository

Focal cortical dysplasia (FCD) are localized regions of malformed cerebral cortex that are frequently associated with drug-resistant epilepsy. Currently, there is a lack of research towards providing quantitative methods for characterizing minor abnormalities in cortical architecture, hindering efforts to determine whether removal affects surgical outcome, and define potential imaging correlates. In our work, we have developed a tool to extract relevant features associated with cortical architectural abnormalities that can deal with artifacts including cortical layer distortions and morphological differences caused by cortical folding effects, and processing artifacts due to improper sectioning. This framework was applied to detect abnormalities across multiple …

Automated Segmentation Of Temporal Bone Structures, Daniel Allen

Electronic Thesis and Dissertation Repository

Mastoidectomy is a challenging surgical procedure that is difficult to perform and practice. As supplementation to current training techniques, surgical simulators have been developed with the ability to visualize and operate on temporal bone anatomy. Medical image segmentation is done to create three-dimensional models of anatomical structures for simulation. Manual segmentation is an accurate but time-consuming process that requires an expert to label each structure on images. An automatic method for segmentation would allow for more practical model creation. The objective of this work was to create an automated segmentation algorithm for structures of the temporal bone relevant to mastoidectomy. …

Analysis Of Roofs Of Wooden Houses Under Uplift Wind Loads- Analytical Solution, Retrofit, And Reliability Analysis, Adnan Farouk Enajar

Electronic Thesis and Dissertation Repository

Observations of post-hurricane events indicate that light-frame wood houses are vulnerable to failure

Observations of post-hurricane events indicate that light-frame wood houses are vulnerable to failure due to the inability of their connections to provide sufficient transfer of uplift wind loads from the roof of the house to the foundation. One of these connections is the roof-to-wall connection (RTWC), which connects roof trusses to the top plate members of the walls. This issue has been investigated through full-scale testing at the Insurance Research Lab for Better Homes. This thesis describes the detailed finite element modelling performed for this full-scale testing …

Understanding The Interplay Between Fluid Mechanics And Particle Size Distributions For Filtration Of Flocculated Mixtures, Brooke Remler

Electronic Thesis and Dissertation Repository

The breakdown of nutrients in biological processes in wastewater treatment require a sub- stantial amount of energy, contributing to greater greenhouse gas (GHG) emissions. Floc- culation can be used to reduce the loading on a biological process by increasing removals during primary treatment in devices such as a rotating belt filter (RBF). The relationship between shear conditions, defined by velocity gradients (G-values) and floc size is crucial. Understanding G-value magnitudes and distributions within an RBF, corresponding trans- port network, and the effects on floc size degradation are needed to maximize removals. G-values were calculated using a newly developed approach, improving …

A Comprehensive Study Of Sequential Simulated Moving Bed: Purification Of Xylo-Oligosaccharides And Fructose-Glucose, Yan Li

Electronic Thesis and Dissertation Repository

Chromatographic separation is a promising alternative for separation and purification of sugars in industry. Simulated moving bed (SMB) technique has been proven as an efficient chromatographic separation method due to its enhanced productivity and purity, reduced solvent consumption, convenient operating control, and improved separation performance for some systems with low resolution and selectivity. The sequential simulated moving bed (SSMB) is a modification of the conventional SMB process, which currently has some applications for sugar separation due to its low solvent consumption. This work mainly investigates the design strategy of the innovative SSMB process and explore its advantages and disadvantages over …

Machine Learning Classification Of Interplanetary Coronal Mass Ejections Using Satellite Accelerometers, Kelsey Doerksen

Electronic Thesis and Dissertation Repository

Space weather phenomena is a complex area of research as there are many different variables and signatures that are used to identify the occurrence of solar storms and Interplanetary Coronal Mass Ejections (ICMEs), with inconsistencies between databases and solar storm catalogues. The identification of space weather events is important from a satellite operation point of view, as strong geomagnetic storms can cause orbit perturbations to satellites in low-earth orbit. The Disturbance storm time (Dst) and the Planetary K-index (Kp) are common indices used to identify the occurrence of geomagnetic storms caused by ICMEs, among several other signatures that are not …

Schrödinger Filtering: A Novel Technique For Removing Gradient Artifact From Electroencephalography Data Acquired During Functional Magnetic Resonance Imaging, Gabriel Bruno Benigno

Electronic Thesis and Dissertation Repository

Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are complementary modalities commonly acquired simultaneously to study brain function with high spatial and temporal resolution. The time-varying gradient fields from fMRI induce massive-amplitude artifacts (GRAs) that overlap in time and frequency with EEG, making GRA removal a challenge for which no satisfactory solution yet exists. We present a new GRA removal method termed Schrödinger filtering (SF). SF is based on semi-classical signal analysis in which a signal is decomposed into a series of energy-based components using the discrete spectrum of the Schrödinger operator. Using a publicly available dataset, we compared our …

Development Of A Co-Rotating, Fully Intermeshing Twin-Screw Extruder Model For The Extrusion Of Natural Fibre Suspensions, Keller J H George

Electronic Thesis and Dissertation Repository

Twin-screw extruders are continuous processing devices that have been used in many industries concerned with the processing of multiphase fibrous suspensions, such as the food and pulping industries. While these devices offer great flexibility due to their modularity and customizability, optimization for specific applications can be challenging due to the unavailability of reliable, global models with accurate predictive capabilities. Consequently, this work seeks to eliminate this knowledge gap with the development of a novel global, composite model capable of predicting key process outputs for suspension-processing, phase-separating, co-rotating, fully-intermeshing twin-screw extruders. Creation of the novel global algorithm involved the modification of …

Design Of Cell-Instructive Biomaterial Scaffolds For Intervertebral Disc Regeneration, Nadia Sharma

Electronic Thesis and Dissertation Repository

Biomaterials-based therapies targeting the nucleus pulposus (NP) have the potential to promote regeneration and restore mechanical function to the intervertebral disc. This study developed composite hydrogels incorporating decellularized NP (DNP) and assessed its effects on viability, retention and differentiation of U-CH1 cells, an NP progenitor-like cell line. A minimal protocol was developed to decellularize bovine NP that reduced nuclear content while preserving key extracellular matrix components predicted to be favourable for bioactivity. The resulting DNP demonstrated cell-instructive effects, supporting U-CH1 viability and retention within the hydrogels, and promoted the differentiation of the progenitor-like cells towards an NP-like phenotype. These studies …

Formation Of A Vascular Regenerative Microenvironment Within Implantable Human Decellularized Adipose Tissue Bioscaffolds, Christopher Leclerc

Electronic Thesis and Dissertation Repository

Cellular therapies targeted at stimulating therapeutic angiogenesis in individuals with critical limb ischemia (CLI) have been under intense investigation. Hematopoietic progenitor cells (HPC) derived from umbilical cord blood have been previously shown to support limb revascularization in animal models of CLI, despite limited cell survival at the site of ischemia. This study attempted to improve HPC survival after transplantation and prolong pro-angiogenic function using human decellularized adipose tissue (hDAT) as a novel cell delivery platform. Compared to HPC conventionally grown on tissue-cultured plastic, hDAT scaffolds were shown to promote viability and proliferation of seeded HPC, and had cell- instructive effects …

Finite Element Analysis Of Hollow-Stemmed Shoulder Implants In Different Bone Qualities Derived From A Statistical Shape And Density Model, Pendar Soltanmohammadi

Electronic Thesis and Dissertation Repository

The incidence of total shoulder arthroplasty procedures (TSA) to treat osteoarthritis has experienced the most rapid growth among all human joint replacements. However, stress shielding of proximal bone following its reconstruction is a complication of TSA triggering unfavorable adaptive bone remodeling, especially for osteoporotic patients.

A better understanding of how the shape and density of the shoulder vary among members of a population can help design more effective population-based orthopedic implants. Therefore, finite element models representing healthy, osteopenic, and osteoporotic bone qualities in a population were developed using our statistical shape and density model. Bones were reconstructed with hollow- and …

A Heterogeneous Patient-Specific Biomechanical Model Of The Lung For Tumor Motion Compensation And Effective Lung Radiation Therapy Planning, Parya Jafari

Electronic Thesis and Dissertation Repository

Radiation therapy is a main component of treatment for many lung cancer patients. However, the respiratory motion can cause inaccuracies in radiation delivery that can lead to treatment complications. In addition, the radiation-induced damage to healthy tissue limits the effectiveness of radiation treatment. Motion management methods have been developed to increase the accuracy of radiation delivery, and functional avoidance treatment planning has emerged to help reduce the chances of radiation-induced toxicity. In this work, we have developed biomechanical model-based techniques for tumor motion estimation, as well as lung functional imaging. The proposed biomechanical model accurately estimates lung and tumor motion/deformation …

Height Measurement Of Basil Crops For Smart Irrigation Applications In Greenhouses Using Commercial Sensors, Leila Bahman

Electronic Thesis and Dissertation Repository

Plant height is a key phenotypic attribute that directly represents how well a plant grows. It can also be a useful parameter in computing other important features such as yield and biomass. As the number of greenhouses increase, the traditional method of measuring plant height requires more time and labor, which increases demand for developing a reliable and affordable method to perform automated height measurements of plants. This research is aimed to develop a solution to automatically measure plant height in greenhouses using low cost sensors and computer vision techniques. For this purpose, the performance of various depth sensing technologies …

An Integrated Framework To Assess Compound Flood Risks For Interdependent Critical Infrastructure In A Coastal Environment, Ying Zhang

Electronic Thesis and Dissertation Repository

Compound flooding refers to flood events caused by multiple factors, including marine processes (e.g. storm tides and waves), hydrometeorological signals (e.g. rainfall and river flows) among others. Saint Lucia is a tropical island in eastern Caribbean Sea, which is frequently affected by weather-related extreme events such as tropical storms and the associated risks are exacerbated due to its mountainous topography and high concentrations of infrastructure and human communities close to the coast. At the southern coast of Saint Lucia, significant infrastructures such as Hewanorra International Airport and Vieux Fort Seaport, and human settlements such as towns of Vieux Fort and …

Catalytic Conversion Of 1,3,5 Tipb Over Y-Zeolite Based Catalysts Catalyst/Oil Ratio(C/O) Effect And A Kinetic Model, Abdualkaber A. Alkhlel

Electronic Thesis and Dissertation Repository

A typical FCC unit involves the transport and rapid catalytic reaction of chemical species using 60-70 micron fluidizable catalyst particles. In FCC, hydrocarbon species evolve in the gas-phase are adsorbed on, and then react with the catalyst particles. In this case, large molecular weight hydrocarbons (vacuum gas oil) are converted into lighter products (gasoline). FCC also yields undesirable products such as light gases and coke. Coke promotes catalyst activity decay and as result, is detrimental to catalyst performance. Given the significance of coke as a catalyst decay agent in FCC, it is the objective of this PhD research to study …

Evaluation Of Biohydrogen Production From Co-Fermentation Of Carbohydrates And Proteins, Emmanuel Andrew Tepari Jr,

Electronic Thesis and Dissertation Repository

The aim of this study was to examine volatile fatty acid (VFA) production from a proteinaceous substrate, bovine serum albumin (BSA) for a pH range of 5 – 9, and to further assess its impact on hydrogen production in a co-fermentation process using starch and BSA at different ratios. The established optimum conditions for VFA production from BSA were an initial pH of 8, incubation time of 3 days and an operating temperature of 37 ℃. Using these fermentation conditions, the stoichiometric reactions that describe the anaerobic degradation of BSA were investigated. A methodology that describes organic acid production from …

The Hydrodynamics And Heat Transfer Of Impinging Jet Flow And Circular Hydraulic Jump, Yunpeng Wang

Electronic Thesis and Dissertation Repository

The laminar axisymmetric flow and heat transfer of a circular impinging jet and hydraulic jump on a solid surface is analyzed theoretically using boundary-layer and thin-film approaches. Liquid jet impingement features many applications such as jet rinsing, jet cooling, liquid atomization and chemical reactors. The associated hydraulic jump dramatically affects the performance of the heat and mass transfer in such applications. In the current thesis, the effects of inertia, surface tension, surface rotation, gravity and heat transfer are comprehensively explored for impinging jet flow and the formation of hydraulic jump.

The boundary-layer heights and film thickness are found to diminish …

Experimental And Numerical Evaluation Of A Novel Piling System For Sound Wall Applications, Daniel Mroz

Electronic Thesis and Dissertation Repository

Drilled shafts are conventionally used as foundations for sound walls. However, steel piles can provide faster installation and immediate utilization. The purpose of this research program is to evaluate a novel pile concept which comprises an H-pile modified to better resist typical load patterns faced by sound wall piles including lateral force and moment from wind and uplift force from adfreeze. The modifications include one or two plates welded to the pile and soil anchors (nodes) welded along the pile flange.

A full-scale pile load testing program was performed on sixteen piles which included monotonic and cyclic lateral load tests …

Shape-Controlled Nanoparticles As Effective Catalysts For Proton Exchange Membrane (Pem) Fuel Cells, Ali Feizabadi

Electronic Thesis and Dissertation Repository

Polymer electrolyte membrane fuel cell (PEMFC), is considered a promising candidate for the next generation power sources in transportation, stationary and portable applications. However, oxygen reduction reaction (ORR), one of the key reactions occurring on PEMFC is kinetically slow; this has limited performance and further advancement in this kind of fuel cells. Thus, improving the PEMFC efficiency requires a thorough understanding of the ORR mechanism on the desired catalyst. To address the above-mentioned demands, the scope of this thesis is focused on the fundamental understanding of facet-controlled nanoparticles, metal-support interactions, and bimetallic platinum catalysts, utilizing synchrotron-based X-ray absorption, X-ray photoelectron …