Engineering Commons^™

Nano-Bio Interactions: Implications And Applications, Anushree Ghosh

McKelvey School of Engineering Graduate Student Theses & Dissertations

Rapid expansion of technology development at the nanoscale has underpinned a promising industry. Towards this, there remain significant information gaps which are critical with regard to decision making processes and ultimate industrial sustainability. From an implication point of view, understanding how common biological macromolecules, including glycolipids and/or biopolymers produced by bacteria and fungi, which are ubiquitous in the environment, is fundamental to predicting the behavior of released/produced nanoparticles. Conversely, other bio-based tailored macromolecules, including mussel foot protein (MFP), have significant potential as functional material coatings for advanced applications.This PhD thesis is focused on interfacial processes related to superparamagnetic iron oxide …

Understanding Control Of Metabolite Dynamics And Heterogeneity, Christopher John Hartline

McKelvey School of Engineering Graduate Student Theses & Dissertations

Microbes live in complex and continually changing environments. Rapid shifts in nutrient availability are a common challenge for microbes, and cause changes in intracellular metabolite levels. Microbial response to dynamic environments requires coordination of multiple levels of cellular machinery including gene expression and metabolite concentrations. This coordination is achieved through metabolic control systems, which sense metabolite concentrations and direct cellular activity in response. Several reoccurring control architectures are found throughout diverse metabolic systems, which suggests underlying evolutionary advantages for using these control systems to coordinate metabolism. One common, yet understudied, control architecture is the positive feedback metabolite uptake loop, which …

Calcium Bearing Mineral-Hydrogel Composites For Phosphate Removal And Recovery, Albern Xuan-Wei Tan

McKelvey School of Engineering Graduate Student Theses & Dissertations

The millions of tons of phosphate rock ore mined every year for use as phosphorus fertilizer have created two challenges. First, phosphate rock is a mined, non-renewable resource that is also heavily geographically concentrated, raising concerns about the long-term sustainability and availability of phosphorus. Second, after it is applied as a fertilizer, phosphorus will also be released to the broader environment. There, it contributes to harmful algal blooms and eutrophication, which threaten surface water quality and can harm aquatic ecosystems and the communities and industries that rely on them. These considerations motivate the coupled development of techniques for removing and …

Foundations For Finite-State Modelling Of A Two-Dimensional Airfoil That Reverses Direction, Jake Michael Oscar Welsh

McKelvey School of Engineering Graduate Student Theses & Dissertations

Current 3-D finite-state wake models are incapable of simulating a maneuver in which the sign of the free-stream velocity changes direction and the rotor enters its own wake -- as might occur in the case of a helicopter which ascends and then descends. It is the purpose of this work to create a 2-D finite-state wake model which is capable of handling changes in free-stream direction as a precursor to development of a 3-D model that can do the same.

The 2-D finite-state model used for reentry modifications is an existing model created by Peters, Johnson, and Karunamoorthy. By the …

Brain Electrophysiology In The Presence Of Acoustic Stimuli, Kristen Howorka

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neuroscience is the study of the structure and function of the brain. This is inclusive of neurochemistry, physiology, anatomy, molecular biology, computer science, engineering and many adjacent disciplines. While there have been a multitude of studies in this field, there are still so many questions left unanswered about the brain. One such question pertains to how animals and humans perceive stimuli from the environmental periphery, a neuroscience sub-area known as sensory processing.

By design, humans have neurological states and receptors which organically take in all of these stimuli and decipher them for everyday needs. Sensory input enables subjects to perform …

Selective Recovery Of Rare Earth Elements Using A Hydroxyapatite-Chitosan Composite, Zixuan Xie

McKelvey School of Engineering Graduate Student Theses & Dissertations

Rare earth elements (REEs) have special properties that make them extremely important in modern clean energy technology. With rising global demand and increasing supply risks, sustainable use of rare earth resources is increasingly imperative. Coal fly ash is a promising source for recovering REEs, but the coexistence of large amounts of non-target elements requires recovery materials with a high preference for REEs. For this recovery study, we found that hydroxyapatite (HAP) that has high density of phosphate groups is efficient in selective REE recovery. The addition of chitosan (CS) as a binder increased the mechanical stability of composites and their …

A Modification To The Skiving Process For The Manufacture Of Offset Geometry Strip-Fin Heat Sinks, Daniel Luberda

McKelvey School of Engineering Graduate Student Theses & Dissertations

High-powered electronics are extremely prevalent, and a vast majority of these devices use some form of heat sinks as either an active or passive cooling device. Although two-phase cooling technology has rapidly advanced to accommodate increasing heat loads on modern electronics, the added costs and complication inherent in two-phase cooling solutions makes effective air-cooled heat sinks potentially valuable.

A more effective heat sink can occupy a smaller footprint to dissipate the same heat flux, meaning material and packaging costs can be reduced. Aluminum heat sinks are produced through a variety of manufacturing processes, including machining, bonding, extrusion, casting, forging, 3D …

The Effects Of Host-Like Environmental Signals And Gene Expression On Capsule Growth In Cryptococcus Neoformans, Yu Min Jung

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cryptococcus neoformans is a fungal pathogen that causes cryptococcosis, a disease that kills almost 200,000 people worldwide each year. A unique feature of this deadly yeast is its polysaccharide capsule, which is known to be associated with its virulence. Here, we systematically explore the effects of all possible combinations of 4 capsule-inducing signals on gene expression, cell size, and capsule size. These signals are medium (YPD, DMEM or RPMI), temperature (30°C or 37°C), CO₂ (room air or 5%), cAMP (0 mM or 20 mM), and pH buffer (HEPES/no HEPES). We explore the effects of exogenous cAMP at a range …

Jme 4110: Battery Operated Extendable Limb Shears, James Lehn, Ngoc Nguyen, Cory Sellers, Larissa Wells

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project entails the design, analysis, and construction process of battery operated extendable limb shears. The design consists of shears mounted on top of extendable poles and is powered by a DeWalt hand-held drill mounted on a manufactured steel box. By using the mechanics of pulleys and tension force, the shears can cut branches up to 1.5 inches in diameter and as tall as 16 feet above the ground.

Jme 4110: Yogurt Lid Remover Device, Odette Beagrie, Seela Wang, Moises Martinez Camarena, Keaton Christensen

Washington University / UMSL Mechanical Engineering Design Project JME 4110

There are not many, if any, products that tackle an issue every demographic, generation, and person faces, removing a yogurt lid completely and without a mess. For the elder generation, this proves more difficult as the lid is not easy to peel off for a variety of yogurts. Lucky enough, there is now a portable, easy to use product that will solve this everyday obstacle; the Yogurt Lid Remover (YLR).

Jme 4110: Rain Barrel Irrigation System, Micah Oaks, Samuel Fallon, Joshua Dooley

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project would be to design and build a prototype sprinkler system using rain barrel technology. The system would need to be scaled up to utilize multiple barrels or one large underground tank. Pumps would be utilized to pressurize the lawn sprinkler system. The pumps would be powered preferably by solar power and/or head pressure. The idea would be to create a modular system to be economically deployed.

Active Testing Of Executive Functions: Toward More Efficient And Equitable Individual Behavioral Modeling, Mariluz Rojo Domingo

McKelvey School of Engineering Graduate Student Theses & Dissertations

Inferences about executive functions are commonly drawn through serial administration of various individual assessments that often take a long time to complete and cannot capture complex trends across multiple variables. In an attempt to improve upon current methods used to estimate latent brain constructs, this thesis makes two primary contributions to the field of behavioral modeling. First, it brings attention to sequential designs for more efficient diagnostic testing of fluctuations in executive functions with respect to a baseline level. It was shown that a sequential framework was successfully capable of detecting significant differences in cognitive performance more rapidly than conventional …

Design Of An Offner-Chrisp Imaging Spectrometer For A Planetary Fluorescence Instrument, Tristan Wells Carlson

McKelvey School of Engineering Graduate Student Theses & Dissertations

Spectrometers have been an integral part of space exploration in the late 20th and 21st centuries and will continue to provide quantitative measurements to answer exciting questions like, “Is or was there life on other planets?” PERISCOPE, Probe for Exploring Regolith and Ice by Subsurface Classification of Organics, Polycyclic aromatic hydrocarbons, and Elements, is a next generation spectrometer designed to explore icy worlds like Europa. It uses time-resolved ultraviolet (UV) fluorescence spectroscopy, a technique that identifies organic molecules, polycyclic aromatic hydrocarbons (PAH), and rare earth elements (REE). Photon wavelength discrimination is very important for this technique and is accomplished by …

Anti-Amyloid Chimeric Antigen Receptor Macrophages For Alzheimer's Disease Immunotherapy, Qiuyun Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Alzheimer’s disease is the most common cause of dementia. None of the available drugs can cure the disease. Chimeric Antigen Receptor (CAR) macrophages, because of their phagocytic activity, have potential as a cellular treatment for amyloid aggregation. In this study, we generated an anti-amyloid CAR hematopoietic progenitor cell line. By inducing the progenitor cell line to differentiate into macrophages, we show that the anti-amyloid CAR-Macrophage has enhanced specific phagocytic activity towards amyloid in in vitro experiments. In addition, in ex vivo experiments, anti-amyloid CAR significantly reduces the plaque load on brain slice from APP/PS1 mice when compared to a non-targeted …

Application Of Neural Networks To Predict Patient-Specific Cellular Parameters In Computational Cardiac Models, Chang Hi Lee

McKelvey School of Engineering Graduate Student Theses & Dissertations

Sudden cardiac death(SCD) is a significant cause of death that accounts for more than 180,000 deaths in the US and 4 million deaths worldwide annually. SCDs are mainly caused by irregular heartbeats called arrhythmias, which are caused by abnormal electrical activity within the heart. Precision medicine, in the form of personalized computational cardiac models of a patient’s heart, can suggest optimal therapies for cardiac arrhythmias. Prior work has used finite element meshes derived from cardiac MRIs to simulate cardiac electrical activity. In this study, I sought to augment this approach by developing a neural network to learn the parameters that …

Application Of Crowdsourcing And Machine Learning To Predict Sentiments In Textual Student Feedback In Large Computer Science Classes, Robert Kasumba

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the increasing enrollment numbers into popular computer science courses, there is a need to bridge the similarly increasing feedback gap between individual students and course instructors. One way to address this challenge is for instructors to collect feedback from students in form of textual reviews or unit-of-study reflections – however, manually reading these reviews is time-consuming, and self-reported Likert scale responses are noisy. Rule-based approaches to sentiment analysis such as VADER (Valence Aware Dictionary and sEntiment Reasoner) have been used to capture the sentiments conveyed in textual feedback, they however fail to capture contextual differences as many words have …

Design Of Polar Materials Using Materials Informatics And First-Principles Calculations, Jon Okenfuss

McKelvey School of Engineering Graduate Student Theses & Dissertations

Polar materials have a dipole moment or polarization. Ferroelectrics are a special class of polar materials wherein the polarization can be switched with an external electric field. Because of their characteristics, ferroelectrics are especially useful in adjustable capacitors, non-volatile memories, and sensors. Materials databases like Materials Project contain a large number of materials, but identifying new metastable polar, and more specifically ferroelectric materials can be time consuming. In this project, we train a machine learning model to distinguish between binary compounds having a wurtzite structure—which have a permanent polarization—and their nonpolar zincblende and rock salt polymorphs. We use this model …

Effect Of Static Magnetic Field On Focused Ultrasound Induced Blood-Brain Barrier Opening, Leqi Yang

McKelvey School of Engineering Graduate Student Theses & Dissertations

No abstract provided.

Motion Field Integrated Reconstruction Using Deep Learning For Mr And Pet/Mr Respiratory Motion Correction, Sihao Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

Since motion is unavoidable in clinical human imaging studies, motion correction in PET and MRI has long been of interest for the liver/lung imaging community. Respiratory motion, the most crucial source of motion in body imaging, affects thoracic organs and the upper/lower abdomen. In MRI, motion can severely blur the images and create artifacts due to incorrect sampling of k-space data in the Fourier domain. In PET imaging, the periodic respiratory motion negatively impacts the detection of small lesions and quantification of PET tracer uptake values. Typically, breath-holding is used in clinical MR scans. However, breath-holding limits spatial coverage and …

Enhancing Pet Functionalities With Novel Geometries And Multimodal Imaging Techniques, Suranjana Samanta

McKelvey School of Engineering Graduate Student Theses & Dissertations

Positron emission tomography (PET) is a highly sensitive imaging modality that can provide in vivo quantitative information of biological processes at a biochemical level. The majority of PET systems have a ring geometry where the detectors fully encircle an axial section of a patient to provide whole-body imaging capability using multiple bed positions. However, these clinical whole-body PET systems are limited in terms of both image resolution and system sensitivity. To achieve a high resolution, customized geometries which trade global utility for application specific performance (breast, small animals etc.) imaging probes may be utilized. In some cases, an application-specific PET …

Multi-Dimensional Single-Molecule Nanoscopy: Fundamental Limits And Novel Approaches, Oumeng Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Single molecules (SMs) have become important tools for studying nanoscale dynamics in biological studies since they were first optically observed in 1989. Numerous techniques, termed single molecule orientation localization microscopy (SMOLM), have been developed to measure the position and orientation of SMs. Due to the challenging signal-to-background ratio (SBR) in typical SM experiments, it is critical to understand whether an imaging system is optimal for a specific target sample. However, the maximum theoretical limit of measurement performance has yet to be quantified. In Chapter 3. We first develop a mathematical framework to compute the accuracy limit in measuring the rotational …

Particle Formation And Thermal Radiation In Laminar Diffusion Flames With Applications To Energy And Materials, Phillip Irace

McKelvey School of Engineering Graduate Student Theses & Dissertations

Fossil fuels supply over 80% of the world’s primary energy, and if current policy and technology trends continue, global energy and energy-related carbon dioxide (CO2) emissions are predicted to increase for at least several decades owing to population and economic growth, leading to serious concerns regarding global warming. Natural gas releases less CO2 than other fossil fuels (e.g., coal and oil) and can help meet future CO2 emission targets. Natural gas combustion, however, has poor radiation heat transfer when compared to other fossil fuels owing to its low propensity for soot formation, making it difficult to use as a drop-in …

Optimization And Information Problems In Operations, Puping Jiang

Olin Business School Graduate Student Theses and Dissertations

The main purpose of this dissertation is to study the optimization problems and the value of information in various commercial settings, especially in the emerging platform economy.

Chapter 1, “Data-Driven Asset Selling”. Motivated by online asset selling marketplace business (e.g., used cars and real estate), we formulate a data-driven asset selling dynamic pricing framework which utilizes platforms’ access to customers’ online behavioral data. With mild assumptions on the demand model, careful characterization of the problem structure shows that the model admits some ideal properties that facilitate our regret analysis under our dynamic programming setting. Instead of studying the policy performance …

Interpreting Uterine Contractions Using Physiological Models And Statistical Signal Processing, Uri Abraham Goldsztejn

McKelvey School of Engineering Graduate Student Theses & Dissertations

Pregnancy and labor are important stages in every mother and child’s life. Unfortunately, complications during pregnancy and labor are common. Every day, globally, about 800 mothers and 7000 newborns in their first month of life die from medical complications. Additionally, these complications result in about 5000 stillbirths daily around the world. Preterm births, labor dystocia, and postpartum hemorrhage are leading causes of maternal and child morbidity and mortality and are associated with inappropriate uterine contractile activity. Preterm births, i.e., those that occur before completing 37 weeks of gestation, are a leading cause of child morbidity and mortality. Preterm birth are …

Design & Analysis Of Mixed-Mode Integrated Circuit For Pulse-Shape Discrimination, Bryan Orabutt

McKelvey School of Engineering Graduate Student Theses & Dissertations

In nuclear science experiments it is usually necessary to determine the type of radiation, its energy and direction with considerable accuracy. The detection of neutrons and discriminating them from gamma rays is particularly difficult. A popular method of doing so is to measure characteristics intrinsic to the pulse shape of each radiation type in order to perform pulse-shape discrimination (PSD).

Historically, PSD capable systems have been designed with two approaches in mind: specialized analog circuitry, or digital signal processing (DSP). In this work we propose a PSD capable circuit topology using techniques from both the analog and DSP domains. We …

Modeling Metastasis In Breast Cancer Patients Using Ehr Data, The Area Deprivation Index (Adi), And Machine Learning Models, Vishesh Patel

McKelvey School of Engineering Graduate Student Theses & Dissertations

Applying machine learning and statistical analysis on traditionally informatics problems is a growing area of research that can result in clinicians being better-able to predict disease outcomes and create more personalized levels of care. In this study, several machine learning models are used to model the likelihood of metastasis in breast cancer patients using a mix of data from the electronic health record and socioeconomic information derived from the Area Deprivation Index (ADI). Metastasis is a late-stage disease progression in a cancer diagnosis where a tumor spreads from its initial development point to another part of the body. In breast …

Locating Unknown Interference Sources With Time Difference Of Arrival Estimates, Chia Ying Kuo

McKelvey School of Engineering Graduate Student Theses & Dissertations

Adaptive spectrum sharing between different systems and operators is being deployed in order to make use of the wireless spectrum more efficiently. However, when the spectrum is shared, it can create situations in which an operator is unable to determine the identity of an interferer transmitting an unknown signal. This is the situation in which the POWDER testbed found itself in, starting in late 2021. This thesis provides general-purpose tools for operators to locate an unknown signal source in real-world outdoor environments. We used cross-correlation between the signals measured at multiple time-synchronized base stations to estimate the time difference of …

A Reconfigurable Fpga Overlay Architecture For Matrix-Matrix Multiplication, Zihao Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

The increasing popularity of deep learning in workloads across vision, speech, and language has inspired many attempts to develop hardware accelerators for matrix-matrix multiplication. Both application-specific integrated circuits (ASICs), and field-programmable arrays (FPGAs) are used for this purpose. However, a trade-off between the two platforms is that ASICs provide little flexibility after they are manufactured while designs on FPGAs are flexible but application development on FPGAs is more time-consuming. In this work, we aim to find the balance between reconfigurability and development efficiency by designing a reconfigurable systolic architecture as an overlay on the FPGA. Our contribution to the reconfigurable …

Tell It Slant: Investigating The Engagement, Discourse, And Popularity Of Data Visualization In Online Communities, Emma Baker

McKelvey School of Engineering Graduate Student Theses & Dissertations

Data visualizations are increasingly accessible to people online, often to non-specialized audiences. However, what we know about how people make sense of data and engage with the visualized content is typically limited to observations from controlled user studies, sometimes with highly-specialized participants. As a result, there is a limited vocabulary to describe how visualizations as a technique of information sharing permeate organic communities. This thesis investigates how data visualization systems infiltrate online social settings and characterizes the conditions under which users engage or do not engage with them. We captured conversations on Reddit from March 2, 2021 to December 31, …

Self-Supervised Joint Image Reconstruction And Coil Sensitivity Calibration In Parallel Mri Without Ground Truth, Yuyang Hu

McKelvey School of Engineering Graduate Student Theses & Dissertations

No abstract provided.