Engineering Commons^™

Estimating And Detecting Slow-Wave Events In Eeg Signals, Zhenghao Xiong

McKelvey School of Engineering Theses & Dissertations

Slow wave activity (SWA) is an electroencephalogram (EEG) pattern commonly occurring during anesthesia and deep sleep, and is hence a candidate biomarker to quantify such states and understand their connection to various phenotypes. SWA consists of individual slow waves (ISW), high-amplitude deflections lasting for approximately 0.5 to 1 second, and occurring quasi-periodically. This latter fact poses a challenge for conventional power spectral density EEG analysis methods that perform best when there is persistency of oscillatory activity. In this work, we pursue a time-domain detection framework for identifying and quantifying ISWs as a metric for SWA. Our method works, in essence, …

Commercial Adsorbents For Co2 Removal For Biogas Upgradation: An Experimental Study, Aakriti Bagla

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Improving And Integrating Quantitative Single Cell Spatial Biology For Theranostic Medicine, Peng Lu

McKelvey School of Engineering Theses & Dissertations

Disease states are the result of a complex interplay of many different cell types interacting in close proximity in the context of often heterogeneous tissues. Alpha particles are drawing intense research and clinical interest because of their potent cytotoxic effects and their short path lengths. Analyzing the dose distribution and tissue micro-environment for alpha therapy plays a key role in predicting the efficacy of this targeted radiotherapy. However, to date there have been no direct on-tissue analytical methods for alpha dose distributions and the corresponding tissue microenvironments.

Therefore, we have developed a pipeline to overcome this limitation by utilizing quantitative …

Enhanced Fabrication Of Microdroplet Generator Nozzle Arrays: Optimizing Koh Etching For Microfluidic Applications, Hongyu Bai

McKelvey School of Engineering Theses & Dissertations

Ultrasonic microdroplet generators are useful devices with broad applications ranging from aerosolized drug delivery to three-dimensional (3D) printing-based additive manufacturing. One such technology comprises a microfabricated array of nozzles with droplet production driven by a piezoelectric transducer. The present study focuses on refining a critical fabrication step, anisotropic wet etching of pyramidal nozzles using a basic potassium hydroxide (KOH) solution. Given the integral role of nozzle geometry in device operation, high-precision techniques including Reactive Ion Etching (RIE), Deep Reactive Ion Etching (DRIE), and KOH wet etching were employed. A tapering geometry is preferred for acoustic wave focusing and efficient droplet …

Design Of Human Serum Albumin And Adenovirus Conjugation Via Catcher/Tag Molecular Glue, Peijie Zhao

McKelvey School of Engineering Theses & Dissertations

Adenovirus (Ad) has been the ideal cargo delivery mechanism, and its moderate immunological response makes it ideal for in vivo gene therapies since its discovery in 1953. However, the robust immunogenicity of the Ad capsid and low vaccine absorption via mucous membranes and epithelium put a limit on the process of developing intranasal vaccines. Efforts are being made to enhance the effectiveness of Ad vectors and numerous studies have demonstrated the remarkable capacity of human serum albumin (HSA) to extend plasma half-life and facilitate targeted intranasal delivery. In this study, we devised an innovative method for employing the Catcher/Tag molecular …

An Apparatus To Quantify Lengthwise Flexural Rigidity Profiles Of Endovascular Devices, Charles B. Suskin

McKelvey School of Engineering Theses & Dissertations

Endovascular procedures require access to distal anatomical sites through the vasculature using catheters and guidewires. Quantitative frameworks for device behavior during procedures hold the potential to drive device design through greater understanding of the mechanical behavior of endovascular devices, and offer the potential to personalize care based on a patient's particular vascular anatomy. However, data that would facilitate this technology are lacking, partly due to undisclosed material properties from manufacturers and partly due to the intricate variations along the length of each device due to material changes and the intersections between them. We developed a three-point bend test methodology on …

Real-Time Analysis Of Aerosol Size Distributions With The Fast Integrated Mobility Spectrometer (Fims), Daisy Wang

McKelvey School of Engineering Theses & Dissertations

The Fast Integrated Mobility Spectrometer (FIMS) has emerged as an innovative instrument in the aerosol science domain. It employs a spatially varying electric field to separate charged aerosol particles by their electrical mobilities. These separated particles are then enlarged through vapor condensation and imaged in real time by a high-speed CCD camera. FIMS achieves near 100% detection efficiency for particles ranging from 10 nm to 600 nm with a temporal resolution of one second. However, FIMS’ real-time capabilities are limited by an offline data analysis process. Deferring analysis until hours or days after measurement makes FIMS' capabilities less valuable for …

Automatic Cardiac Mri Image Segmentation And Mesh Generation, Ziyuan Li

McKelvey School of Engineering Theses & Dissertations

Segmenting and reconstructing cardiac anatomical structures from magnetic resonance (MR) images is essential for the quantitative measurement and automatic diagnosis of cardiovascular diseases [1]. However, manual evaluation of the time-series cardiac MRI (CMRI) obtained during routine clinical care are laborious, inefficient, and tends to produce biased and non-reproducible results [2]. This thesis proposes an end-to-end pipeline for automatically segmenting short-axis (SAX) CMRI images and generating high-quality 2D and 3D meshes suitable for finite element analysis. The main advantage of our approach is that it can not only work as a stand-alone pipeline for the automatic CMR image segmentation and mesh …

Calculating The Difference In Stiffness Of Living T Cells Through Micropipette Aspiration, Minju Lee

McKelvey School of Engineering Theses & Dissertations

Cardiovascular disease (CVD) accounted for 17.9 million deaths in 2019, with fibrosis contributing to nearly a quarter of these fatalities [1,2]. Fibrosis, characterized by excessive connective tissue formation, has been strongly linked to T cells, essential components of the immune system. This study explores the mechanisms of T cell activation and the subsequent changes in biophysical properties like diameter, stiffness, and elasticity, aiming to develop therapeutic strategies for fibrosis-related diseases, including CVD. Utilizing the micropipette aspiration technique, we accurately assessed T cell stiffness and observed a change in bulk cell stiffness upon activation. The results demonstrated increased fluid-like behavior in …

Watch: A Distributed Clock Time Offset Estimation Tool On The Platform For Open Wireless Data-Driven Experimental Research, Cassie Jeng

McKelvey School of Engineering Theses & Dissertations

The synchronization of the clocks used at different devices across space is of critical importance in wireless communications networks. Each device’s local clock differs slightly, affecting the times at which packets are transmitted from different nodes in the network. This thesis provides experimentation and software development on POWDER, the Platform for Open, Wireless Data-driven Experimental Research, an open wireless testbed across the University of Utah campus. We build upon Shout, a suite of Python scripts that allow devices to iteratively transmit and receive with each other and save the collected data. We introduce WATCH, an experimental method to estimate clock …

Design Of Microwave Superconducting Resonators For Materials Characterization, Xinyi Zhao

McKelvey School of Engineering Theses & Dissertations

A resonator is a specialized device capable of storing and transferring energy at precise frequencies. Resonators find widespread use in various fields, such as electrical engineering, physics, and material science, owing to their exceptional ability to accurately measure, filter, and amplify signals. Different types of resonators exist, but coplanar waveguide (CPW) and coupled coplanar waveguide (CCPW) resonators are popular due to their high-frequency operation and easy integration into microfabrication processes.

Mirror Position Detection In A Catoptric Surface, Run Zhang

McKelvey School of Engineering Theses & Dissertations

The Catoptric Surface research project is a pioneering exploration of controlling daylight effects within built environments. In this thesis, we focus on the mirror position detection problem, which plays a vital role in achieving dynamic control over the direction of reflected light within a space. To address the challenge of mirror position detection, we employ computer vision techniques, specifically edge detection and the RANdom SAmple Consensus (RANSAC) algorithm. Edge detection is utilized to identify significant changes in intensity or color, corresponding to object boundaries, while RANSAC is applied for ellipse fitting. By iteratively selecting minimal subsets of points and fitting …

Performance And Emissions Study Of N+3 And N+4 Engine Models With Several Fuel Types Using Npss, Abel Solomon

McKelvey School of Engineering Theses & Dissertations

The aviation industry is known to be one of the major contributors to greenhouse gases accounting for 4.9% of the global greenhouse emissions. With the ever-increasing threat of climate change to the overall survival of the planet, the exploration of new technologies and alternative energy sources that minimize greenhouse gas emissions are of paramount importance. In this regard, the development of propulsion systems well suited for the performance and emissions requirements of future commercial aircraft plays a crucial role. This thesis investigates N+3 and N+4 technology-level propulsion systems that are proposed by NASA as possible propulsion systems for advanced single-aisle …

The Effect Of Spinal Cord Stimulation And Video Games Training On Body-Machine Interface Control, Jie Fei

McKelvey School of Engineering Theses & Dissertations

Damage to the spinal cord causes long-lasting loss of motor and sensory function, and currently, there is no ‘cure’ for paralysis. However, even people with severe spinal cord injuries (SCI) have some residual mobility. Studies have shown that transcutaneous electrical spinal cord stimulation (tSCS) combined with functional training targeting residual mobility can further improve the motor function of individuals with SCI. In this study, we present a technical framework that aims to enhance rehabilitation outcomes by targeting residual mobility through a motor training-based approach. Our technical framework centers around a non-invasive body-machine interface (BoMI) that relies on the use of …

Novel Microfluidic Devices To Model The Interactions Between Lymphatics And Breast Cancer, Jade Weber

McKelvey School of Engineering Theses & Dissertations

The lymphatic system is responsible for immune circulation and fluid balance in the body. It accomplishes this by draining interstitial fluid from local tissue and transferring it to lymph nodes and back into blood circulation. However, this process is implicated in many pathologies, one of the most dangerous being breast cancer metastasis to the lymph nodes. The largest factor in breast cancer patient mortality is metastasis. Lymphangiogenesis, the growth of new lymphatic vessels, has been thought to play a dynamic role in aiding breast cancer metastasis. Breast cancer tumor cells have been shown to remodel the functionality of local lymph …

Targeted Adversarial Attacks Against Neural Network Trajectory Predictors, Kaiyuan Tan

McKelvey School of Engineering Theses & Dissertations

Trajectory prediction is an integral component of modern autonomous systems as it allows for envisioning future intentions of nearby moving agents. Due to the lack of other agents' dynamics and control policies, deep neural network (DNN) models are often employed for trajectory forecasting tasks. Although there exists an extensive literature on improving the accuracy of these models, there is a very limited number of works studying their robustness against adversarially crafted input trajectories. To bridge this gap, in this paper, we propose a targeted adversarial attack against DNN models for trajectory forecasting tasks. We call the proposed attack TA4TP for …

Two-Dimensional Field Effect Transistor, Yimeng Li

McKelvey School of Engineering Theses & Dissertations

As silicon-based field-effect transistors (FETs) approach their physical limits with channel lengths approaching 5 nm, the search for new semiconductor materials that can surpass this limit has become urgent. Two-dimensional layered semiconductor nanomaterials, represented by graphene, have emerged as promising candidates due to their unique physical, mechanical, and chemical properties. Unlike traditional silicon-based FETs, two dimensional (2D) layered nanomaterials are held together by van der Waals forces between layers, with no dangling bonds on the material surface, which can effectively address the short-channel effect issue faced by traditional silicon-based FETs. However, unlike traditional silicon-based FETs, which have matured fabrication systems, …

Optical Perturbation Of Protein Kinase A Activity Via Photoactivatable Inhibitor Peptides, Peter Chen

McKelvey School of Engineering Theses & Dissertations

Protein Kinase A (PKA) plays important roles in diverse biological processes such as sleep, long term memory, and synaptic plasticity. In addition, PKA also acts as an integrator of neuromodulator signaling though G protein-coupled receptor activation. However, despite genetic knockout and pharmacological inhibition experiments that demonstrate the importance of PKA, it is unclear where, when, or how PKA plays these roles in cellular physiology and behavior. In order to better understand the function of PKA in these processes, and how neuromodulator signaling drives complex behavioral changes, there exists a need for a method to selectively activate/inactivate PKA with high spatial …

Dual Color Optogenetic Control For Analyzing Cardiac Function In Drosophila, Jiantao Zhu

McKelvey School of Engineering Theses & Dissertations

Prolonged consumption of carbohydrate-rich diets and immobile lifestyles frequently cause metabolic disorders and obesity and, as a result, may lead to progressive heart dysfunction among broad social groups of the population. Drosophila melanogaster serves as an essential model organism in cardiovascular disease research due to conserved physiological and genomic traits shared with humans, its genetic and molecular toolbox versatility, and cost-effective maintenance. Here, we combine optogenetics and optical coherence tomography to study cardiovascular function in D. melanogaster. A new optogenetic pacing system has been developed, employing a transgenic line carrying two opsins: ChR2 and NpHR2.0. A custom-built hardware setup …

A Novel Mrna Delivery Strategy Employing Adenovirus Piggyback Mrna Binders Via Catcher/Tag Molecular Glue, Kexin Geng

McKelvey School of Engineering Theses & Dissertations

mRNA-based therapeutics open a new era for the prevention and treatment of a wide range of diseases. However, existing mRNA delivery vehicles have limited repertoires for dendritic cell targeting and intranasal administration which are two paramount delivery pathways of significant advantages for treating cancer and infectious respiratory diseases. Adenovirus (Ad) with well-deciphered viral genomes and intensive-studied structure biology has been developed for DCs-targeted cancer vaccines and intranasal COVID vaccines. In light of these virtues, Ad presents as the “off-the-shelf” tool possessing well-defined manufacturable capabilities and translatable feasibility that perfectly complements the current limitations of mRNA delivery. In this study, we …

Adversarial Patch Attacks On Deep Reinforcement Learning Algorithms, Peizhen Tong

McKelvey School of Engineering Theses & Dissertations

Adversarial patch attack has demonstrated that it can cause the misclassification of deep neural networks to the target label when the size of patch is relatively small to the size of input image; however, the effectiveness of adversarial patch attack has never been experimented on deep reinforcement learning algorithms. We design algorithms to generate adversarial patches to attack two types of deep reinforcement learning algorithms, including deep Q-networks (DQN) and proximal policy optimization (PPO). Our algorithms of generating adversarial patch consist of two parts: choosing attack position and training adversarial patch on that position. Under the same bound of total …

3-Dimensional Visualization Of Cardiac Plaque Mapping Data, Phan Ly Vy Nguyen

McKelvey School of Engineering Theses & Dissertations

Atrial Fibrillation (AF) of one of the most prevalent cardiac arrythmia in humans, and also the most studied arrythmias due to its high association with cardiovascular morbidity and mortality. Diagnosis of AF, which is highly dependent on the observation of the irregular signal in the atria, is often challenging since AF is often asymptomatic at the onset. There has been a lot of effort in exploring different cardiac mapping techniques to understand the dynamics of AF for better intervention. This study aims at developing a MATLAB interface that assists the development of a cardiac plaque mapping data acquisition system in …

Preparing Non-Human Primates To Study Hand-Eye Coordination In Frontal Eye Fields (Fef) During Delayed Movement Task, Juliusz Cydzik

McKelvey School of Engineering Theses & Dissertations

ABSTRACT OF THE THESIS Preparing Non-Human Primates to Study Hand-Eye Coordination in Frontal Eye Fields (FEF) During Delayed Movement Task by Juliusz Cydzik Master of Science in Biomedical Engineering Washington University in St. Louis, 2023 Professor Lawrence Snyder, Chair Hand-eye coordination enables humans and non-human primates to use their hands and eyes to perform various tasks. We are interested in coordination at the systems level, where saccades and reaches are encoded. The parietal reach region (PRR), situated at the posterior end of the intraparietal sulcus (IPS) and overlapping portions of the medial intraparietal area (MIP) and V6a, is commonly attributed …

A General-Purpose Software Platform For Closed-Loop Neuromodulation, William Engelhardt

McKelvey School of Engineering Theses & Dissertations

Implementing closed-loop neuromodulation therapies is a challenging and expensive endeavor. It requires developing software capable of acquiring signals from a bio-signal amplifier, analysis of these signals, and initiation of precisely timed stimulation, all of which need to be accomplished in real-time with very low latency. Developing this software is difficult, as it requires a wide range of expertise ranging from interfacing with hardware to real-time signal processing. Even when successfully implementing such a system for one set of hardware, it often then only works within the laboratory that conceived it. This is because of the inherent heterogeneity in the devices …

Development Of Methods To Enhance Stem Cell Derived Islet Survival, Aining Fan

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Synthesis And Characterization Of Sodium Cathode Materials, He Zhou

McKelvey School of Engineering Theses & Dissertations

As sodium batteries hold great promise as a next-generation energy storage device to replace lithium batteries, the development of sodium battery materials has become increasingly urgent. The current study aims to investigate two potential sodium-ion battery cathode materials, Sodium Vanadium Phosphate, and Sodium Manganese Hexacyanoferrate, optimize the experimental procedures, conduct a systematic analysis of material properties and characterization, and ultimately determine the ideal synthesis conditions for these materials.

In the first part of the study, we focused on optimizing the synthesis of Sodium Vanadium Phosphate. By investigating various synthesis conditions, such as annealing temperature, pressure, ascorbic acid content, and material …

Computational Analysis Of Steady Hypersonic Flow Fields Of Nasa Benchmark Geometries Utilizing Ansys Fluent, Aidan Murphy

McKelvey School of Engineering Theses & Dissertations

The Hypersonic International Flight Research Experimentation (HIFiRE) program explores and advances hypersonic aerospace systems by developing a multitude of test flight geometries and conducting experimental test flights to obtain data for use in validation of computational models and results. This study focuses on computational validation of heat flux, and calculation of static pressure profiles, skin friction coefficient profiles, and flow contours. The flow fields studied are for Mach number 7.18 and angles of attack (α) of 0° & 2°. These flow fields include many compressible flow features such as an expansion wave at the intersection of the cone and flat …

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …

Analytical And Experimental Investigation Of Interphase And Dispersion Effects On The Mechanical Stiffness Of Cellulose Nanocomposites, Will Goldberg

McKelvey School of Engineering Theses & Dissertations

The effect of dispersion and interphase properties on the elastic behavior of cellulose nanocomposites was investigated using a number of composite models, experimental data and a thorough literature review. Cellulose nanocomposites consisting of soy protein isolate (SPI) and cellulose nanocrystals (CNC) or polydopamine coated cellulose nanocrystals (PD-CNC) were prepared via solution casting method and tested for mechanical stiffness. These outcomes were compared to standard composite models as well as novel methods adapted from the literature that incorporate data regarding dispersion quality and interphase properties. The literature review verified that both dispersion and interphase properties are highly dependent on interfacial chemistry …

Persistence Of Dna From Biocontained Genetically Engineered Microbes, Wentao Dai

McKelvey School of Engineering Theses & Dissertations

The utilization of genetically engineered microbes in environmental systems requires effective biocontainment mechanisms to ensure their safe operation. CRISPR-based kill switches are a promising solution, inducing cell death through site-specific DNA cleavage under specific environmental conditions. In this study, we aimed to assess the impact of CRISPR-based kill switches on the abundance and persistence of bacterial DNA. Our results revealed that while CRISPR-based kill switches were capable of achieving high reductions in viable Escherichia coli Nissle 1917 (EcN); the DNA largely remained intact. This was observed in two strains of EcN: one enabled with multi-locus genome cleavage, and the other …