Engineering Commons^™

Prototype Instrument Development For Measuring Directionality Of Aerosol Light Scattering, Esther K. Monroe

McKelvey School of Engineering Theses & Dissertations

Investigation of aerosol interactions with electromagnetic waves provides insights into the scattering particles. Aerosol phase function, an angular distribution of scattered light, is a value required to calculate parameters used in direct radiative forcing (DRF) models in the atmosphere. Currently no direct measurement of phase function is available hence it is estimated from ground observations such as backscatter fraction b and subsequently relating the parameters via Henyey-Greenstein (HG) approximation. This method has shown to introduce errors in radiation transfer models. HG phase function, in particular, does not account for particle microphysical properties such as shape and refractive index. Given the …

Production Of Medical Radioisotopes Using Titanium Accelerator Targets, Christopher Shaun Loveless

Arts & Sciences Electronic Theses and Dissertations

Theranostic radiopharmaceuticals enable diagnostic imaging and radionuclide therapy in patients using a single molecular agent labeled with a diagnostic-therapeutic pair (e.g., 68Ga/177Lu) or a theranostic radionuclide (e.g., 131I). This theranostic approach can help inform patient-specific treatment plans and improve clinical outcomes. Radionuclide pairs used in theranostic agents fall into two categories: pseudo matched-pairs (e.g., 68Ga/177Lu) and matched-pairs (e.g., 124I/131I). Pseudo matched-pair radionuclides have similar chemistries and pharmacokinetics when bound to the same bioconjugate molecule. In contrast, identical chemistries and pharmacokinetics can be obtained by using the matched-pair radionuclides.

The isotopes of Sc include two diagnostic radioisotopes, 43Sc & 44Sc, and …

Separating Signal From Noise In High-Density Diffuse Optical Tomography, Arefeh Sherafati

Arts & Sciences Electronic Theses and Dissertations

High-density diffuse optical tomography (HD-DOT) is a relatively new neuroimaging technique that detects the changes in hemoglobin concentrations following neuronal activity through the measurement of near-infrared light intensities. Thus, it has the potential to be a surrogate for functional MRI (fMRI) as a more naturalistic, portable, and cost-effective neuroimaging system. As in other neuroimaging modalities, head motion is the most common source of noise in HD-DOT data that results in spurious effects in the functional brain images. Unlike other neuroimaging modalities, data quality assessment methods are still underdeveloped for HD-DOT. Therefore, developing robust motion detection and motion removal methods in …

New Modeling Approaches For The Prediction Of Combustion Pollutants, Phillip R. Johnson

McKelvey School of Engineering Theses & Dissertations

Combustion processes are ubiquitous to human technological development and provide many benefits such as large-scale power generation for electricity and transportation along with residential and commercial heating for manufacturing, cooking, and warmth. However, these various processes can also have harmful effects on human health and the environment via emission of CO2 and other pollutants such as NOx and particulate matter (PM; often in the form of soot). For these reasons, there is a continued need for controlling, improving, and optimizing combustion processes. Modeling of these processes provides powerful insights into system-level dynamics and their control. Due to the size and …

Structural Organization And Chemical Activity Revealed By New Developments In Single-Molecule Fluorescence And Orientation Imaging, Tianben Ding

McKelvey School of Engineering Theses & Dissertations

Single-molecule (SM) fluorescence and its localization are important and versatile tools for understanding and quantifying dynamical nanoscale behavior of nanoparticles and biological systems. By actively controlling the concentration of fluorescent molecules and precisely localizing individual single molecules, it is possible to overcome the classical diffraction limit and achieve 'super-resolution' with image resolution on the order of 10 nanometers.

Single molecules also can be considered as nanoscale sensors since their fluorescence changes in response to their local nanoenvironment. This dissertation discusses extending this SM approach to resolve heterogeneity and dynamics of nanoscale materials and biophysical structures by using positions and orientations …

Pathophysiology And Proteogenomics Of Post-Infectious And Post-Hemorrhagic Hydrocephalus In Infants, Albert M. Isaacs

Arts & Sciences Electronic Theses and Dissertations

Post-infectious (PIH) and post-hemorrhagic (PHH) hydrocephalus occur as sequalae of neonatal sepsis or intraventricular hemorrhage (IVH) of prematurity, respectively. Together, PIH and PHH represent the most common form of infantile hydrocephalus, the most common indication for neurosurgery in children globally, and the leading cause of neurological morbidity and mortality worldwide. The lack of understanding of the pathophysiology of PIH and PHH, particularly with regards to the host central nervous system response to the antecedent infection and hemorrhage, perturbation of differentiating neural stems in the ventricular (VZ) and subventricular (SVZ) zones, and damage to periventricular white matter (PVWM) tracts carrying sensorimotor …

Growth Of Small Particles In Nonequilibrium Plasmas, Necip Berker Üner

McKelvey School of Engineering Theses & Dissertations

Nonequilibrium plasma (NEP) is an extraordinary environment for material synthesis. NEP is comprised of hot electrons with temperatures greater than 10000 K and of cold ions and neutrals that are usually at few hundred kelvins above room temperature. Due to this large difference in species’ temperatures, the assumption of local thermal equilibrium does not hold in NEP. Therefore, NEP can act as a unique processor of mass, and it can transform materials along pathways that are not accessible by methods wherein local thermal equilibrium is valid. For decades, NEPs have been employed in the semiconductor industry to manufacture many thin …

Domain Specific Computing In Tightly-Coupled Heterogeneous Systems, Anthony Michael Cabrera

McKelvey School of Engineering Theses & Dissertations

Over the past several decades, researchers and programmers across many disciplines have relied on Moores law and Dennard scaling for increases in compute capability in modern processors. However, recent data suggest that the number of transistors per square inch on integrated circuits is losing pace with Moores laws projection due to the breakdown of Dennard scaling at smaller semiconductor process nodes. This has signaled the beginning of a new “golden age in computer architecture” in which the paradigm will be shifted from improving traditional processor performance for general tasks to architecting hardware that executes a class of applications in a …

Advanced Materials For Air Pollutants Removal In A Combustion System, Sungyoon Jung

McKelvey School of Engineering Theses & Dissertations

Air pollutants directly or indirectly impact human health and the environment. Large quantities of CO2, volatile organic compounds (VOCs), and particulate matter are emitted from combustion systems, and cause climate change, smog formation, and pose serious health risks. The increasing demand for the remediation of air pollutants at the source has drawn much attention to the use of advanced materials due to their high reactivities and special properties. In order to achieve the successful application of advanced materials for the remediation of problematic emissions, three aspects, (1) synthesis method, (2) characterization of materials’ structural properties, and (3) evaluation of materials’ …

Microrna Gene Expression States Underlying Individual Variation In Aging And Lifespan In Isogenic C. Elegans, Holly Kinser

McKelvey School of Engineering Theses & Dissertations

Average lifespan differs greatly between species, but lifespan among same-species individuals is also highly variable. While much effort has been devoted to uncovering longevity-associated traits and lifespan-extending perturbations in humans and model organisms, how differences in lifespan arise between individuals is unknown. Studies of human identical twins demonstrate that surprisingly little of the variation in lifespan between individuals can be explained by genetics and shared environment. Furthermore, even genetically identical C. elegans reared in highly homogeneous environments display a degree of variability in lifespan similar to that of outbred human populations. Thus, longevity must be determined at least in part …

Aging Effects On Arterial Mechanics And Matrix Remodeling, Jie Hawes

McKelvey School of Engineering Theses & Dissertations

Large elastic arteries are a composite structure composed of cells and extracellular matrix proteins. Passive arterial mechanical behavior is determined by the composition of extracellular matrix proteins, in particular elastin and collagen. Elastin provides reversible elasticity to the large elastic arteries during cyclic loading and dampens the pulsatile flow from the left ventricle, reducing the workload on the heart and protecting the end organs. Disorganization and insufficiency of elastin alters the passive mechanical behavior of the large arteries. The arterial wall responds to changes in elastin organization or amount through matrix remodeling. Aging causes elastin fragmentation and degradation which changes …

Convex Relaxations For Particle-Gradient Flow With Applications In Super-Resolution Single-Molecule Localization Microscopy, Hesam Mazidisharfabadi

McKelvey School of Engineering Theses & Dissertations

Single-molecule localization microscopy (SMLM) techniques have become advanced bioanalytical tools by quantifying the positions and orientations of molecules in space and time at the nanoscale. With the noisy and heterogeneous nature of SMLM datasets in mind, we discuss leveraging particle-gradient flow 1) for quantifying the accuracy of localization algorithms with and without ground truth and 2) as a basis for novel, model-driven localization algorithms with empirically robust performance. Using experimental data, we demonstrate that overlapping images of molecules, a typical consequence of densely packed biological structures, cause biases in position estimates and reconstruction artifacts. To minimize such biases, we develop …

A Thesis On The Interactions Between Lead Pipe Scales And Dissolved Silica From The Addition Of Sodium Silicate As A Corrosion Inhibitor, Ziqi Wang

McKelvey School of Engineering Theses & Dissertations

Ingestion of lead-contaminated drinking water is one of the major pathways for human exposure to lead. Addition of sodium silicate can potentially control lead release from lead service lines (LSLs) to the water that they convey, but the mechanism of silica uptake and corrosion control have not been reported. Knowledge of variables which affect the uptake of dissolved silica and the consumption rate of added sodium silicate by scales of corrosion products that are present on lead service lines will be useful to water utilities and distribution systems. This study investigated the effects of pH, initial silica concentration and mass …

First-Principles Investigation Of Doping And Alloying Of Β-Ga2o3, Ben Tattersfield

McKelvey School of Engineering Theses & Dissertations

β-Ga₂O₃ is an emergent semiconductor for power electronics applications. It has a wide band gap of 4.8 eV and is transparent on the whole spectrum of visible light up to deep ultraviolet. It has a high Baliga figure of merit (BFOM) — a weighted numerical combination of the dielectric constant, charge carrier mobility, and critical breakdown field —, which is commonly used for a quantitative comparison of semiconductors for high-current operation and power switching applications. β-Ga₂O₃ can be grown as thin films or as large single crystals by melt growth-techniques, which is …

Data Processing Electronics For An Ultra-Fast Single-Photon Counting Camera, Jackson Hyde

McKelvey School of Engineering Theses & Dissertations

Localizing photon arrivals with high spatial (megapixel) and temporal (sub-nanosecond) resolution would be transformative for a number of applications, including single-molecule super-resolution fluorescence microscopy. Here, the Data Processing Field Programmable Gate Array (FPGA) is developed as an ultra-fast computational platform built on an FPGA for a microchannel plate (MCP)-photomultiplier tube (PMT) based single-photon counting camera. Each photon is converted by the MCP-PMT into an electron cloud that generates current pulses across a 50×50 cross-strip anode. The Data Processing FPGA executes a massively parallel center-of-gravity coordinate determination algorithm on the digitized current pulses to determine a 2D position and time of …

Investigating Single Precision Floating General Matrix Multiply In Heterogeneous Hardware, Steven Harris

McKelvey School of Engineering Theses & Dissertations

The fundamental operation of matrix multiplication is ubiquitous across a myriad of disciplines. Yet, the identification of new optimizations for matrix multiplication remains relevant for emerging hardware architectures and heterogeneous systems. Frameworks such as OpenCL enable computation orchestration on existing systems, and its availability using the Intel High Level Synthesis compiler allows users to architect new designs for reconfigurable hardware using C/C++. Using the HARPv2 as a vehicle for exploration, we investigate the utility of several of the most notable matrix multiplication optimizations to better understand the performance portability of OpenCL and the implications for such optimizations on this and …

Cfd Evaluation Of Blood Flow In An Improved Blalock-Taussig Shunt Using Patient Specific Geometries, Zhenghao Lin

McKelvey School of Engineering Theses & Dissertations

Blalock-Taussig (BT) Shunt is a palliative surgical procedure used during a Norwood surgery on a newborn baby suffering from cyanotic heart defects. The BT Shunt can increase blood flow in patients’ pulmonary artery which can ease the “Blue Baby Syndrome.” Currently used BT Shunts do not produce a balanced flow distribution to the pulmonary arteries (PAs) which can cause high wall shear stress (WSS) and blood flow separation resulting in blood clots. A modified BT Shunt was designed to partially solve this problem. In our previous work [1], the modified BT Shunt was shown by numerical simulations to have the …

Tissue Engineering Of Induced Pluripotent Stem Cells For The Development Of Novel Treatment Strategies For Osteoarthritis, Alison Ross

McKelvey School of Engineering Theses & Dissertations

Osteoarthritis (OA) is a debilitating joint disease that is primarily characterized by the degeneration of articular cartilage, the soft connective tissue that covers articulating bone surfaces in diarthrodial joints. While there are a number of risk factors for developing OA, the progression of this disease is mediated in part by pro-inflammatory cytokines from both the synovium and chondrocytes, the resident cells of articular cartilage. These cytokines, specifically interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF-α), induce aberrant expression of catabolic and degradative enzymes and inflammatory cytokines in OA, which promotes degradation of engineered tissues as well as native articular …

Chemistry Of Nanoscale Solids And Organic Matter In Sustainable Water Management Systems, Xuanhao Wu

McKelvey School of Engineering Theses & Dissertations

To alleviate global water scarcity and improve public health, engineered water treatment and management systems have been developed for purifying contaminated water and desalinating brackish or ocean water. These engineered systems provide substantial amounts of potable water and lessen environmental concerns about the release of contaminated water. Wastewater treatment plants (WWTPs), water desalination plants (WDPs), and managed aquifer recharge systems (MARs) are three representative sustainable water management (SWM) systems. But the operation of all three poses two fundamental questions: (1) What is the fate of nanoscale solids (e.g., engineered nanomaterials, naturally occurring nanoparticles) in SWM systems and how will their …

Ultrafine Particle-Particle And Particle-Ion Interactions In Aerosol Reactors, Girish Sharma

McKelvey School of Engineering Theses & Dissertations

Aerosol science and technology has enabled the material synthesis of ‘good’ nanoparticles, as well as, addressed the problem of air pollution by developing particle capture technologies for ‘bad’ nanoparticles. For material synthesis at industrial scale, flame aerosol reactors are extensively used for large-scale industrial production of ‘good’ nanoparticles. But, there exists a knowledge gap in understanding the early stages (1-10 nm) of particle formation and growth, which is necessary for tailoring the synthesized nanoparticles’ properties. To achieve this goal, measurement tools for the characterization of 1-10 nm particles are quintessential. On the other hand, to capture ‘bad’ particles, existing control …

Nucleation Dynamics For Water Condensation On Hydrophobic Surfaces In The Presence Of Non-Condensable Gases, Xinyu Jiang

McKelvey School of Engineering Theses & Dissertations

The density and rate of nucleation (here-in called nucleation density rate) significantly influences the heat transfer performance during dropwise condensation, as more than 70% of the total heat transfer happen for droplets smaller than 10 μm. Based on the classical nucleation theory, supersaturation strongly influences nucleation dynamics. However, the presence of non-condensable gas can strongly reduce the nucleation density rate by forming a vapor-depleted gas diffusion layer. Therefore, this work studied the relationship between nucleation density rate and supersaturation ratio during dropwise condensation on subcooled smooth hydrophobic surfaces with the presence of non-condensable gases in a custom-built condensation chamber. High-speed …

Applying Bayesian Techniques To The Optimization Of Parameterized Quantum Circuits, Arthur Rattew

McKelvey School of Engineering Theses & Dissertations

In this work, we explore the challenges faced when creating quantum algorithms for near-term quantum computers. We examine the characteristics of problems that are amenable to such advantage, and the limitations of existing approaches. Additionally, we explore the importance of the classical optimizer in the Variational Quantum Eigensolver (VQE), and propose a Bayesian method to optimally configure a single parameter in a given quantum circuit. Experimental testing confirms that our method is significantly more tolerant to noise than the existing analytical approach and its variants (p < 0.008).

Blood Flow Simulation Of Particle Trapping In Models Of Arterial Bifurcations, Qihang Xu

McKelvey School of Engineering Theses & Dissertations

This thesis describes the particle trapping mechanism in blood flow in different arterial bifurcation models. For validation of CFD calculations, a T-junction model and a Y-junction model are analyzed. In both the models, there is one inlet pipe with two outlet pipes creating a symmetric bifurcation at some angle from the centerline of the inlet pipe. Naiver-Stokes (RANS) equations are solved for single phase laminar flow using the commercial CFD software ANSYS Fluent. After validation, Eulerian simulations are performed by using the Discrete Phase Model (DPM) for two-phase flow with particles injected in different bifurcation models with bifurcation angle of …

The Role Of Gene Transcription And Inflammatory Cytokines In Bone Fracture Repair, Brandon Alan Coates

McKelvey School of Engineering Theses & Dissertations

In most instances, the skeleton has a remarkable capacity for repair following injury. However, in 5 to 10% of patients, fractures fail to properly heal resulting in non-union. A need exists for a more comprehensive understanding of the complex biology of fracture repair, which involves the coordinated work of many cell types including osteoblasts, osteoclasts, and immune cells. Depending on the extent of injury, fractures will heal through either intramembranous bone formation, involving the direct formation of bone callus, or endochondral bone formation, featuring a cartilage intermediary prior to bone callus formation. Both processes begin with inflammation, which sets the …

Exploring Usage Of Web Resources Through A Model Of Api Learning, Finn Voichick

McKelvey School of Engineering Theses & Dissertations

Application programming interfaces (APIs) are essential to modern software development, and new APIs are frequently being produced. Consequently, software developers must regularly learn new APIs, which they typically do on the job from online resources rather than in a formal educational context. The Kelleher–Ichinco COIL model, an acronym for “Collection and Organization of Information for Learning,” was recently developed to model the entire API learning process, drawing from information foraging theory, cognitive load theory, and external memory research. We ran an exploratory empirical user study in which participants performed a programming task using the React API with the goal of …

Predicate Informed Syntax-Guidance For Semantic Role Labeling, Sijia Wang

McKelvey School of Engineering Theses & Dissertations

In this thesis, we consider neural network approaches to the semantic role labeling task in seman-tic parsing. Recent state-of-the-art results for semantic role labeling are achieved by combiningLSTM neural networks and pre-trained features. This work offers a simple BERT-based modelwhich shows that, contrary to the popular belief that more complexity means better performance,removing LSTM improves the state of the art for span-based semantic role labeling. This modelhas improved F1 scores on both the test set of CoNLL-2012, and the Brown test set of CoNLL-2005 by at least 3 percentage points.In addition to this refinement of existing architectures, we also propose …

Exploring Attacks And Defenses In Additive Manufacturing Processes: Implications In Cyber-Physical Security, Nicholas Deily

McKelvey School of Engineering Theses & Dissertations

Many industries are rapidly adopting additive manufacturing (AM) because of the added versatility this technology offers over traditional manufacturing techniques. But with AM, there comes a unique set of security challenges that must be addressed. In particular, the issue of part verification is critically important given the growing reliance of safety-critical systems on 3D printed parts. In this thesis, the current state of part verification technologies will be examined in the con- text of AM-specific geometric-modification attacks, and an automated tool for 3D printed part verification will be presented. This work will cover: 1) the impacts of malicious attacks on …

Cfd Analysis Of A Wind Turbine Airfoil With Flap, Heyou Tan

McKelvey School of Engineering Theses & Dissertations

The focus of this thesis is to evaluate the aerodynamic performance of NREL S809 airfoil (widely used airfoil for wind turbine blades) with a trailing-edge flap by numerical simulations. In the simulations, the geometry of the flap and the gap between the main element and the flap are varied. The airfoil geometry is created in Design Modeler and structured mesh around the airfoil is generated using meshing software ICEM. Simulations are performed using the Reynolds-Averaged Navier-Stokes (RANS) equations with SST k-ω, Spalart-Allmaras (SA) and Wray-Agarwal (WA) turbulence models at Reynolds number 106 at angles of attack of 0, 5o, 10o, …

First-Principles Studies Of Anion Engineering In Functional Ceramics, Steven Timothy Hartman

McKelvey School of Engineering Theses & Dissertations

Ceramic materials display a wide variety of valuable properties, such as ferroelectricity, superconductivity, and magnetic ordering, due to the partially covalent bonds which connect the cations and anions. While many breakthroughs have been made by mixing multiple cations on a sublattice, the equivalent mixed-anion ceramics have not received nearly as much attention, despite the key role the anion plays in the materials’ properties. There is great potential for functional ceramics design using anion engineering, which aims to tune the materials properties by adding and removing different types of anions in existing classes of ceramic materials. In this dissertation, I present …

Ultrasound Guided Diffuse Optical Tomography For Breast Cancer Diagnosis: Algorithm Development, K M Shihab Uddin

McKelvey School of Engineering Theses & Dissertations

According to National Breast Cancer Society, one in every eight women in United States is diagnosed with breast cancer in her lifetime. American Cancer Society recommends a semi-annual breast-cancer screening for every woman which can be heavily facilitated by the availability of low-cost, non-invasive diagnostic method with good sensitivity and penetration depth. Ultrasound (US) guided Diffuse Optical Tomography (US-guided DOT) has been explored as a breast-cancer diagnostic and screening tool over the past two decades. It has demonstrated a great potential for breast-cancer diagnosis, treatment monitoring and chemotherapy-response prediction. In this imaging method, optical measurements of four different wavelengths are …