Engineering Commons^™

Molecularly Targeted Nanoparticles For Modulation Of Inflammatory Mediators In Atherosclerosis, Rohun Udatta Palekar

McKelvey School of Engineering Theses & Dissertations

The enzyme thrombin has been demonstrated through experimental and clinical studies to play a crucial role in mediating both inflammation and thrombosis in atherosclerosis. The cellular effects of thrombin in promoting atherosclerosis involve the activation of signaling pathways that result in the secretion of a host of various chemokines, cytokines, cell adhesion molecules, etc. that promote vascular inflammation. Due in part to thrombin and other pro-atherogenic molecules, this prolonged inflammatory state in atherosclerosis results in the deterioration of the endothelium, increasing the risk of focal thrombosis. Current treatment strategies to address the role of thrombin in atherosclerosis, despite efficacy of …

Segmentation And Strain Mapping Of A Beating Heart, Kenna Middleton

McKelvey School of Engineering Theses & Dissertations

Conventional methods of estimating deformation optically often compare image intensities before and after deformation to help estimate the strain fields. However, these current meth ods often introduce undesirable error that propagates through the system, growing larger through each strain calculation. These errors create false, concentrated regions of strain throughout the image. Additionally, gathering and evaluating images in three- and four dimensional space creates even more difficulty for conventional methods. Here, by imple menting new techniques of gathering four-dimensional ultrasound data sets and calculating deformation fields with traditional errors reduced three-fold, four-dimensional images were evaluated to create a novel visualization tool …

Understanding The Nano- And Macroscale Processes Impacting Arsenic Mobilization During Managed Aquifer Recharge Using Reclaimed Wastewater, Chelsea Wren Neil

McKelvey School of Engineering Theses & Dissertations

Managed aquifer recharge (MAR) utilizing reclaimed wastewater is a vital means of replenishing natural freshwater supplies in order to meet growing demands. Unfortunately, this process has been found to induce unfavorable geochemical reactions which mobilize arsenic from aquifer sediments. This process is further complicated by the simultaneous formation of iron(III) (hydr)oxide secondary minerals, which can sorb aqueous arsenic. It is crucial to fully elucidate these physico-chemical processes in order to establish safe MAR operations which minimize arsenic release. Thus, the mechanisms controlling arsenic release from arsenopyrite during MAR were investigated from the nano- to macroscale.

First, nanoscale iron(III) (hydr)oxide nucleation …

Automating Intensity Modulated Radiation Therapy Treatment Planning By Using Hierarchical Optimization, Paras Babu Tiwari

McKelvey School of Engineering Theses & Dissertations

The intensity modulated radiation therapy (IMRT) optimizes the beam’s intensity to deliver the prescribed dose to the target while minimizing the radiation exposure to normal structures. The IMRT optimization is a complex optimization problem because of the multiple conflicting objectives in it. Due to the complexity of the optimization, the IMRT treatment planning is still a trial and error process. Hierarchical optimization was proposed to automate the treatment planning process, but its potential has not been demonstrated in a clinical setting. Moreover, hierarchical optimization is slower than the traditional optimization. The dissertation studied a sampling algorithm to reduce the hierarchical …

Copper And Zinc Oxide Composite Nanostructures For Solar Energy Harvesting, Fei Wu

McKelvey School of Engineering Theses & Dissertations

Solar energy is a clean and sustainable energy source to counter global environmental issues of rising atmospheric CO2 levels and depletion of natural resources. To extract useful work from solar energy, silicon-based photovoltaic devices are extensively used. The technological maturity and the high quality of silicon (Si) make it a material of choice. However limitations in Si exist, ranging from its indirect band gap to low light absorption coefficient and energy and capital intensive crystal growth schemes. Therefore, alternate materials that are earth-abundant, benign and simpler to process are needed for developing new platforms for solar energy harvesting applications.

In …

Measurement, Modeling, And Mitigation Of Lead Impacts From General Aviation, Stephen Neil Feinberg

McKelvey School of Engineering Theses & Dissertations

Airborne lead (Pb) has been regulated as a criteria pollutant by the United States Environmental Protection Agency (EPA) since the Clean Air Act and its amendments in the 1970s. During the 1970s, atmospheric Pb emissions were dominated by the combustion of leaded automobile fuel and metals manufacturing. Over time, those emissions have decreased greatly and according to the EPA the largest emitter of Pb today is piston-engine aircraft. Additionally, in 2008 the EPA reduced the National Ambient Air Quality Standard (NAAQS) for Pb by an order of magnitude. These combined factors served as the impetus for further study of general …

Novel Applications Of Electrostatic Precipitators In Coal - Biomass Combustion Systems, He Jing

McKelvey School of Engineering Theses & Dissertations

Pulverized coal combustion is an important source of electricity production worldwide. However, it is also a primary air pollution emission (particulate matters, mercury, etc.) source. Electrostatic precipitators (ESPs) are widely used in coal-fired power plants to control particulate matters. This dissertation contributes in the study of the pollution formation from coal combustion processes and pollution control based on ESPs in the following three aspects: (1) explore novel applications of ESPs in particulate matters and mercury removal; (2) develop and evaluate an compact electrostatic precipitator for sampling purpose, which can support offline fly ash particle analysis; (3) study the submicrometer particle …

Data Structures And Algorithms For Scalable Ndn Forwarding, Haowei Yuan

McKelvey School of Engineering Theses & Dissertations

Named Data Networking (NDN) is a recently proposed general-purpose network architecture that aims to address the limitations of the Internet Protocol (IP), while maintaining its strengths. NDN takes an information-centric approach, focusing on named data rather than computer addresses. In NDN, the content is identified by its name, and each NDN packet has a name that specifies the content it is fetching or delivering. Since there are no source and destination addresses in an NDN packet, it is forwarded based on a lookup of its name in the forwarding plane, which consists of the Forwarding Information Base (FIB), Pending Interest …

Thermally Evolved & Separated Composition Of Atmospheric Aerosols: Development And Application Of Advanced Data Analysis Techniques For A Thermal Desorption Aerosol Gas Chromatograph (Tag), Yaping Zhang

McKelvey School of Engineering Theses & Dissertations

Atmospheric organic aerosols are composed of thousands of individual compounds, interacting with climate through changes in aerosol optical properties and cloud interactions, and can be detrimental to human health. Aerosol mass spectrometry (MS) and gas chromatography (GC)-separated MS measurements have been utilized to better characterize the chemical composition of this material that comes from a variety of sources and experiences continuous oxidation while in the atmosphere. This dissertation describes the development of a novel rapid data analysis method for grouping of major components within chromatography-separated measurements and first application using thermal desorption aerosol gas chromatograph (TAG) – MS data. Chromatograms …

Optimization Of Looped Airfoil Wind Turbine (Lawt) And Looped Airfoil Hydro-Turbine (Laht) Design Parameters For Maximum Power Generation, Binhe Song

McKelvey School of Engineering Theses & Dissertations

This focus of this research is on the study of the aerodynamic performance of a Looped Airfoil Wind Turbine (LAWT™) using the Computational Fluid Dynamics (CFD) software. The looped airfoil wind turbine (LAWT™) is a patented new technology by EverLift Wind Technology, Inc. for generating power from wind. It takes advantage of the superior lift force of a linearly traveling wing compared to the rotating blades in conventional wind turbine configurations. Compared to horizontal and vertical axis wind turbines, the LAWT™ can be manufactured with minimal cost because it does not require complex gear systems and its blades have a …

Applying Bayesian Machine Learning Methods To Theoretical Surface Science, Shane Carr

McKelvey School of Engineering Theses & Dissertations

Machine learning is a rapidly evolving field in computer science with increasingly many applications to other domains. In this thesis, I present a Bayesian machine learning approach to solving a problem in theoretical surface science: calculating the preferred active site on a catalyst surface for a given adsorbate molecule. I formulate the problem as a low-dimensional objective function. I show how the objective function can be approximated into a certain confidence interval using just one iteration of the self-consistent field (SCF) loop in density functional theory (DFT). I then use Bayesian optimization to perform a global search for the solution. …

Cyber-Physical Co-Design Of Wireless Control Systems, Bo Li

McKelvey School of Engineering Theses & Dissertations

Wireless sensor-actuator network (WSAN) technology is gaining rapid adoption in process industries because of its advantages in lowering deployment and maintenance cost in challenging environments. While early success of industrial WSANs has been recognized, significant potential remains in exploring WSANs as unified networks for industrial plants.

This thesis research explores a cyber-physical co-design approach to design wireless control systems. To enable holistic studies of wireless control systems, we have developed the Wireless Cyber-Physical Simulator (WCPS), an integrated co-simulation environment that integrates Simulink and our implementation of WSANs based on the industrial WirelessHART standard. We further develop novel WSAN protocols tailored …

Relating Neural Dynamics To Olfactory Coding And Behavior, Chao Li

McKelvey School of Engineering Theses & Dissertations

Sensory stimuli often evoke temporal patterns of spiking activity across a population of neurons in the early processing stages. What features of these spatiotemporal responses encode behaviorally relevant information, and how dynamic processing of sensory signals facilitates information processing are fundamental problems in sensory neuroscience that remain to be understood. In this thesis, I have investigated these issues using a relatively simple invertebrate model (locusts; Schistocerca americana).

In locusts, odorants are transduced into electrical signals by olfactory sensory neurons in the antenna and are subsequently relayed to the downstream neural circuit in the antennal lobe (analogous to the olfactory bulb …

Clinical Application Of Electrocardiographic Imaging In Patients With Ischemic Cardiomyopathy, Early Repolarization Syndrome And Brugada Syndrome, Junjie Zhang

McKelvey School of Engineering Theses & Dissertations

Electrocardiographic Imaging (ECGI) is a noninvasive modality for human application in both research and clinical settings. It is an important tool for investigation of abnormal electrophysiological (EP) substrates and arrhythmias in patients. Multi-channel body surface potential recordings and the patient-specific heart-torso geometry from ECG gated computed tomography are processed by ECGI algorithms to reconstruct epicardial potentials, electrograms and patterns of activation and repolarization. ECGI is able to continuously generate high-resolution, panoramic EP maps of the entire heart on a beat-by-beat basis, which cannot be achieved with invasive catheter mapping.

ECGI was applied in ischemic cardiomyopathy patients to characterize the abnormal …

High Resolution Multi-Parametric Diagnostics And Therapy Of Atrial Fibrillation: Chasing Arrhythmia Vulnerabilities In The Spatial Domain, Sarah Gutbrod

McKelvey School of Engineering Theses & Dissertations

After a century of research, atrial fibrillation (AF) remains a challenging disease to study and exceptionally resilient to treatment. Unfortunately, AF is becoming a massive burden on the health care system with an increasing population of susceptible elderly patients and expensive unreliable treatment options. Pharmacological therapies continue to be disappointingly ineffective or are hampered by side effects due to the ubiquitous nature of ion channel targets throughout the body. Ablative therapy for atrial tachyarrhythmias is growing in acceptance. However, ablation procedures can be complex, leading to varying levels of recurrence, and have a number of serious risks. The high recurrence …

Spectrum Management Using Markov Decision Processes, John Leo Meier

McKelvey School of Engineering Theses & Dissertations

Abstract: The advent of cognitive radio technology has enabled dramatically more options in the use of RF spectrum, allowing multiple transmitters to effectively share spectrum in ways that were previously unavailable (either due to technical limitations or regulatory restrictions). In this dissertation, we investigate approaches to managing RF spectrum use, with a focus on combining multiple control decisions in a mutually beneficial manner.

Our approach to making spectrum management decisions is grounded in Markov decision theory, which has a rich formal foundation and is frequently used to guide decision making in other disciplines. Here, we develop a set of Markov …

Sustained Dual Drug Delivery Of Anti-Inhibitory Molecules For Spinal Cord Injury Treatment, Thomas Wilems

McKelvey School of Engineering Theses & Dissertations

Regeneration of lost synaptic connections following spinal cord injury (SCI) is limited due to local ischemia, cell death, and an excitotoxic environment, which leads to the development of an inhibitory glial scar surrounding a cystic cavity. Myelin-associated inhibitors (MAIs) and chondroitin sulfate proteoglycans (CSPGs) are major inhibitors to axon growth inhibition found within the glial scar and limit functional recovery. The NEP1-40 peptide competitively binds the Nogo receptor and partially blocks inhibition from MAIs, while chondroitinase ABC (ChABC) enzymatically digests CSPGs, which are upregulated at the site of injury. The first part of this work develops drug delivery systems which …

Bio-Inspired Multi-Spectral Imaging Sensors And Algorithms For Image Guided Surgery, Shengkui Gao

McKelvey School of Engineering Theses & Dissertations

Image guided surgery (IGS) utilizes emerging imaging technologies to provide additional structural and functional information to the physician in clinical settings. This additional visual information can help physicians delineate cancerous tissue during resection as well as avoid damage to near-by healthy tissue. Near-infrared (NIR) fluorescence imaging (700 nm to 900 nm wavelengths) is a promising imaging modality for IGS, namely for the following reasons: First, tissue absorption and scattering in the NIR window is very low, which allows for deeper imaging and localization of tumor tissue in the range of several millimeters to a centimeter depending on the tissue surrounding …

Optimal Battery Operations And Design Considering Capacity Fade Mechanisms, Bharatkumar Suthar

McKelvey School of Engineering Theses & Dissertations

Safely and capacity fade are the key issues that restrict the use of the lithium-ion battery for many applications. These issues are being tackled in a variety of ways. This dissertation focuses on using detailed continuum-level electrochemical models to study transport, kinetics, and mechanical processes in the lithium-ion batteries. These models can be used to quantify the effect of capacity fade mechanisms (side reactions and mechanical degradation) and improve the safety aspects of the lithium ion batteries. Three capacity-fade mechanisms—solid electrolyte interface side reaction, lithium-plating side reaction and mechanical degradation due to intercalation-induced stresses—are considered in the dissertation. Monitoring and …

Synthesis Of Clickable Poly(Ethylene Glycol) Derivatives For Fabrication Of Modular Microsphere-Based Scaffolds To Promote Vascularization, Peter Nguyen

McKelvey School of Engineering Theses & Dissertations

Vascularization plays an important role in supporting transplanted tissues and cells in tissue engineering applications. Most tissues require access to blood vessels for the delivery of oxygen and nutrients, as well as the removal of carbon dioxide and cellular waste products. Without an adequate blood supply, cells within tissue-engineered constructs and scaffolds lose viability and fail to perform their intended functions. The goal of this dissertation was to design scaffolds that can promote vascularization of biomaterial implants for biomedical applications. In order to accomplish this goal, clickable poly(ethylene glycol) (PEG) derivatives were synthesized in order to fabricate modular microsphere-based scaffolds …

Smoke Aerosol Characterization For Spacecraft Fire Detection Systems, Marit Elisabeth Meyer

McKelvey School of Engineering Theses & Dissertations

Appropriate design of fire detection systems requires knowledge of both the expected fire signature and the background aerosol levels. Terrestrial fire detection systems have been developed based on extensive study of terrestrial fires. Unfortunately there is no corresponding data set for spacecraft fires and consequently the fire detectors in current spacecraft were developed based upon terrestrial designs. There are a number of factors that affect the smoke particle size distribution in spacecraft fires. In low gravity, buoyant flow is negligible which causes particles to concentrate at the smoke source, increasing their residence time, and increasing the transport time to smoke …

Shape Optimization Of Busemann-Type Biplane Airfoil For Drag Reduction Under Nonlifting And Lifting Conditions Using Genetic Algorithms, Yi Tian

McKelvey School of Engineering Theses & Dissertations

The focus of this thesis is on the shape optimization of the Busemann-type biplane airfoil for drag reduction under both nonlifting and lifting conditions using genetic algorithms. The concept of the Busemann-type biplane airfoil was first introduced by Adolf Busemann in 1935. Under its design condition at a specific supersonic flow speed, the Busemann biplane airfoil eliminates all wave drag due to its symmetrical biplane configuration; however it produces zero lift. Previous research has shown that the original Busemann biplane airfoil design has a poor performance under off-design conditions as well. In order to solve this problem of zero lift …

Online Modeling And Tuning Of Parallel Stream Processing Systems, Jonathan Curtis Beard

McKelvey School of Engineering Theses & Dissertations

Writing performant computer programs is hard. Code for high performance applications is profiled, tweaked, and re-factored for months specifically for the hardware for which it is to run. Consumer application code doesn't get the benefit of endless massaging that benefits high performance code, even though heterogeneous processor environments are beginning to resemble those in more performance oriented arenas. This thesis offers a path to performant, parallel code (through stream processing) which is tuned online and automatically adapts to the environment it is given. This approach has the potential to reduce the tuning costs associated with high performance code and brings …

Cfd Simulation And Shape Optimization Of Supersonic Ejectors For Refrigeration And Desalination Applications, Liju Su

McKelvey School of Engineering Theses & Dissertations

The aim of this thesis is to investigate the detailed flow field inside the supersonic ejector using numerical methods and to optimize the ejector’s mixing chamber wall shape to obtain a maximum entrainment ratio (ER) in order to obtain the highest possible efficiency that can be attained by the ejector. A steam ejector applied in the cooling industry is first studied to determine the most accurate turbulence model for its supersonic jet flow field simulation with mixing with the entrained steam in the mixing chamber. A commercial Computational Fluid Dynamics (CFD) package FLUENT 14.5 along with the meshing tool ICEM …

System Level And Reactor Level Simulations Of Chemical Looping Combustion And Chemical Looping With Oxygen Uncoupling, Xiao Zhang

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Growth Factor Gradient Formation And Release From Peg Microspheres For Nerve Regeneration., Jacob Roam

McKelvey School of Engineering Theses & Dissertations

Many biological processes depend on concentration gradients in signaling molecules. Thus, introduction of spatial patterning of proteins, while retaining activity and releasability, will be critical for the field of regenerative medicine. In particular, the area of nerve regeneration is in need of innovations to improve outcomes. Only about 25% of surgical patients with peripheral nerve damage (~200,000 surgical interventions performed each year) regain full motor function with less than 3% regaining sensation. The use of nerve guidance conduits (NGC’s) which are filled with biomimetic scaffolds is one treatment being explored. These scaffolds, however, lack the spatial patterning of proteins found …

Photoacoustic Microscopy And Photoacoustic Computed Tomography Using High-Frequency Linear Array Ultrasonic Transducers, Guo Li

McKelvey School of Engineering Theses & Dissertations

Photoacoustic tomography (PAT) is a highly promising imaging technology which forms images by detecting the induced pressure waves resulting from pulsed light absorption in biological tissues. Because the excitation source is light, PAT is a very safe, non-ionizing, and non-carcinogenic imaging technology. In biomedicine, PAT has the unique advantage of probing endogenous optical absorbers at different length scales with 100% relative sensitivity. With such scalability, PAT can image anatomical, functional, metabolic, molecular, and genetic contrasts of vasculature, hemodynamics, oxygen metabolism, biomarkers, and gene expression. Among several implementations of PAT, optical-resolution photoacoustic microscopy (OR-PAM) and photoacoustic computed tomography (PACT) are two …

Spontaneous Firing Of Sensory Neurons Modulates The Gain In The Downstream Circuit Of A Simple Olfactory System, Matthew O'Neill

McKelvey School of Engineering Theses & Dissertations

In locusts and other insects, odorants are transduced into electrical signal by the olfactory receptor neurons and transmitted to central circuits for further processing. Previous studies have shown that exogenous variables (e.g., flow rates, humidity, temperature, odor mixtures, etc.) can influence the responses of the sensory neurons and therefore modulate the central circuits. However, how the sensory neuron activity is manipulated to achieve adaptive gain control in the following circuit is yet to be understood. It is possible that the magnitude of the stimulus-evoked response in the receptor neurons, their spontaneous activity, or both of these factors can change how …

Process And Reactor Level Simulations Of Calcium Looping Combustion, Wei Dai

McKelvey School of Engineering Theses & Dissertations

Calcium looping (CaL) is a recent technology for carbon capture from coal fired power plants which consumes less energy than other approaches such as oxy-fuel. In the first part of this thesis, a system level model is developed in ASPEN PLUS to calculate the energy penalty of introducing Calcium looping in a coal fired power plant. Several simplifications and assumptions are made to model the Calcium looping process. The relationship between the energy penalty due to CaL and carbon capture efficiency is used to validate the process model for both pre-combustion CaL and post-combustion CaL; it agrees well with the …

Diamond Coated Wire Cutting Of Solar Si Ingots: New Insights Using Raman Microspectroscopy, Junting Yang

McKelvey School of Engineering Theses & Dissertations

Diamond embedded abrasive wire (henceforth called diamond wire) sawing process of Si is a highly efficient technique for rapid wafering of solar Si ingots. However, the root causes for cutting efficiency losses are unknown. One approach to understanding this complex process is to study 1) diamond particles on diamond coated wire (DCW) and 2) Si swarf collected during cutting process. In this thesis, we use confocal, micro Raman spectroscopy to unravel loss mechanisms of wafer sawing efficiency.

In the first part, we analyze the diamond microparticles which perform the sawing. By analyzing the phase transformation and stress distribution on single …