Engineering Commons^™

In Vitro Comparative Study Of Composite Coatings For Magnesium-Based Bone Implants, Abdelrahman Amin, Bryce Williams, Thomas Mcgehee, Alyssandra Navarro, Vipul Patil, Mostafa Elsaadany, Hanna Ibrahim

Biomedical Engineering Faculty Publications and Presentations

This study provides a comparative assessment of the corrosion, morphology, and biological properties of four of the most promising coating methods for magnesium in biomedical applications, namely micro-arc oxidation (MAO), graphene oxide (GO)-containing MAO coating, MAO/sol-gel composite coating, and MAO/polycaprolactone (PCL) polymer dip coating approaches. Despite the abundance of research focused on these promising coating approaches, there is a notable lack of comparative studies evaluating their properties. To this end, the investigated composite coatings are ZK60+MAO, ZK60+MAO/GO, ZK60+MAO/Sol-gel, and ZK60+MAO/PCL composite coating. Several tests were used to assess various properties of the prepared groups such as in vitro corrosion characteristics, …

Universal Shape Replication Via Self-Assembly With Signal-Passing Tiles, Andrew Alseth, Daniel Hader, Matthew J. Patitz

Computer Science and Computer Engineering Faculty Publications and Presentations

In this paper, we investigate shape-assembling power of a tile-based model of self-assembly called the Signal-Passing Tile Assembly Model (STAM). In this model, the glues that bind tiles together can be turned on and off by the binding actions of other glues via “signals”. Specifically, the problem we investigate is “shape replication” wherein, given a set of input assemblies of arbitrary shape, a system must construct an arbitrary number of assemblies with the same shapes and, with the exception of size-bounded junk assemblies that result from the process, no others. We provide the first fully universal shape replication result, namely …

Medium-Entropy Engineering Of Magnetism In Layered Antiferromagnet CuXNi2(1-X)CrXP2S6, Dinesh Upreti, Rabindra Basnet, M. M. Sharma, Santosh Karki Chhetri, Gokul Acharya, Md Rafique Un Nabi, Joshua Sakon, Mourad Benamara, Mansour Mortazavi, Jin Hu

Physics Faculty Publications and Presentations

Antiferromagnetic van der Waals-type M₂P₂X₆ compounds provide a versatile material platform for studying 2D magnetism and relevant phenomena. Establishing ferromagnetism in 2D materials is technologically valuable. Though magnetism is generally tunable via a chemical way, it is challenging to induce ferromagnetism with isovalent chalcogen and bimetallic substitutions in M₂P₂X₆. Here, we report co-substitution of Cu¹⁺ and Cr³⁺ for Ni²⁺ in Ni₂P₂S₆, creating Cu_xNi_2(1-x)Cr_xP₂S₆ medium-entropy alloys spanning a full substitution range ( …

Assessing The Effect Of Material Properties On Full Depth Reclamation (Fdr) Mixtures Via Compressive Strength Characterization, Toluwanimi Ogundipe

Graduate Theses and Dissertations

Enormous amounts of money to replace all poorly maintained roads with brand new construction or with rehabilitation options like the mill and overlay which neglects the address of underlying pavement issues. To reduce the cost intensity of new construction of dilapidated pavements, state departments of transportation are seeking cost-effective techniques to rehabilitate roads. One of the techniques that have been explored and implemented by state DOTs is full-depth reclamation. Full depth reclamation (FDR) as a pavement rehabilitation technique is the reclaiming and recycling of an existing pavement with a predetermined amount of existing base layer. The combination of the reclaimed …

Controlling Expansion Behavior Through Curing And Mix Design For An Expansive, Rapid-Setting Bcsa Cement, Amanda Parolini Dutra

Graduate Theses and Dissertations

Cracking in concrete has been a concern for engineers because it reduces its durability and strength. Some of this cracking behavior is due to shrinkage, which occurs when the water in the concrete evaporates and causes a reduction in volume. Expansive cements were invented to counteract this shrinkage behavior. This research studies a new formulation of a standalone, fast-setting, fast-strength gain expansive BCSA cement. Since it is a new cement, a limited amount of literature is available about mixture design, strength properties, and how to obtain the desired level of expansion. This study then aims to fill some of these …

Determination Of The Internal Erosion Potential Of Bcsa Soil-Cement Using A Modified Hole Erosion Test System, Edgar Enrique Ortega De La Cruz

Graduate Theses and Dissertations

Levees play a fundamental role in preserving human lives and resources and are the key infrastructure protecting against flood events. In the United States, the levee system is extensive, but unfortunately many of the levees were either not engineered or have well exceeded their intended design life. This was evident after the Midwest floods of 2019, which resulted in the failure of multiple levees leading to costly losses and repairs. In addition, flood levels remained high for days at a time, making it imperative to find fast and effective repair methods. This thesis presents a study conducted at the University …

Advanced Numerical Techniques For Multiscale Simulations In Biofluid Dynamics, Justin Tamico Jack

Graduate Theses and Dissertations

The study of anisometric particle suspensions and congenital heart defects (CHDs) involve exploring complex phenomena within the biological sciences. The former subject dives into the phase behavior of liquid crystals (LCs), particularly the influence of the shape anisotropy of rod-like nanoparticles on phase transitions, through the implementation of statistical techniques involving molecular dynamics (MD). Conversely, the latter topic focuses on the assessment and management of severe congenital arterial stenoses, such as those found in Williams-Beuren syndrome (WS), through advanced multi-scale computational fluid dynamics (CFD) simulations. Both areas emphasize the importance of detailed analysis and the use of advanced numerical modeling …

Paste Properties, Hardened Concrete Properties, And Mix Design Process For Magnesium Phosphate Cement, Rilye Dillard

Graduate Theses and Dissertations

Magnesium phosphate cement (MPC) is a rapid-setting alternative cement typically used as a quick repair material. MPC has gained popularity in recent years due to its ability to reduce CO2 emissions, its strong chemical resistance, and potential use in large scale applications. There is currently limited research on the properties of MPC when varying the proportions of its ingredients. Several hardened concrete properties were analyzed on concrete mixtures made with MPC. A mix design process for MPC concrete is proposed based on testing of 300 MPC paste mixtures and 115 MPC concrete mixtures. A standardized mix design process is imperative …

An Investigation Into The Effect Of Performance Engineered Mixture (Pem) Design On The Workability And Strength Of Concrete Pavement Mixtures, Alexander Cook

Graduate Theses and Dissertations

The Arkansas Department of Transportation (ARDOT) currently requires a minimum cement content of 564 pounds of cement per cubic yard of concrete. This minimum cement requirement can be reduced through the utilization of optimized gradation of aggregates within concrete mixtures as well as the addition of supplementary cementitious materials (SCMs) such as fly ash. The study presented in this paper aims to demonstrate how the use of the Tarantula Curve can be used to design concrete mixtures with reduced cement contents while maintaining sufficient workability for concrete mixtures to be used for slipform paving. Fresh workability was measured using the …

An Empirical Study On The Capability Of Large Language Models In Learning Causality, Joseph Bergin

Electrical Engineering and Computer Science Undergraduate Honors Theses

Large language models (LLMs), including Google’s Gemini, OpenAI’s GPT series, and Meta’s Llama, have driven remarkable advancements in artificial intelligence, achieving complex, human-like performance across many fields. These transformer-based models are skilled at processing and generating many types of textual information, enabling them to perform a variety of tasks. However, an important question remains about their actual capacity to grasp causal relationships—whether these models can truly differentiate between causal directions or simply respond based on learned patterns. This thesis tests this ability by evaluating LLMs on tasks created to test their understanding of causal, anti-causal, and third-party reasoning. We conduct …

Leveraging P4 Programmable-Hardware Switches For In-Network Pmu Packet Recovery, Evan Michael Bonar

Electrical Engineering and Computer Science Undergraduate Honors Theses

Phasor Measurement Unit (PMU) systems are essential for real-time power grid monitor- ing but often face data loss due to network delays, equipment malfunctions, or transmis- sion errors. Traditional centralized recovery solutions introduce significant latency and scalability challenges. This thesis presents a P4-based in-network recovery mechanism that embeds detection and recovery directly into the data plane of P4-enabled programmable switches, significantly reducing recovery time and infrastructure complexity. Using the Aurora 610 switch, the system detects missing packets via sequence number analysis and recovers magnitudes with an efficient register-based algorithm.

Evaluation demonstrates high accuracy and low latency, achieving a mean absolute …

Enhancing Webtas: From An Atam Simulator To A Developmental Environment, Elizabeth G. Schmidt

Electrical Engineering and Computer Science Undergraduate Honors Theses

As interest in a niche research area, like the abstract Tile Assembly Model (aTAM), grows it is crucial to ensure that simulation tools are accessible and user-friendly for a broad audience. Existing resources can pose challenges for less experienced users, highlighting the need for enhancements that improve usability and functionality. To address these issues, key upgrades to the current online simulation platform, WebTAS, were implemented, including breakpoint functionality and nondeterminism checks, alongside features such as XML file integration, image capturing, and simulation view resets. These enhancements collectively elevate the platform from a basic learning tool to a comprehensive environment for …

Cytotoxicity And Genotoxicity Of Glyphosate And Roundup Quickpro On Chinese Hamster Ovary Cells, Tasnimul Ferdous

Graduate Theses and Dissertations

Glyphosate and Roundup products have become the most used herbicide worldwide. However, previous bans in Europe and recent reversal have caused confusion over their safety. This study aims to investigate the cytotoxic and genotoxic effects of Roundup QuickPro and its main ingredient glyphosate using Chinese hamster ovary (CHO) cells. Cytotoxicity was calculated by measuring CHO cell viability with 72 hours of exposure to each toxicant. Roundup exhibited higher cytotoxicity with LC50 of 511.2 μg/mL than glyphosate’s LC50 of 3389 μg/mL. The recommended application concentration (11,233.7 μg/mL) of Roundup QuickPro is much higher than the measured LC50, which caused complete cell …

Integrating Sustainability And Food Safety Through Quantitative Microbial Risk Assessment And Life Cycle Assessment Of Low-Moisture Foods, Jessica Bain

Graduate Theses and Dissertations

Food safety and sustainability are critical concerns in the food industry. However, these areas are often evaluated separately, leading to an incomplete understanding of the overall impact of food production on human health. This dissertation aims to integrate food safety with sustainability to provide a comprehensive assessment of the impact of low-moisture foods on human health, using the almond processing supply chain as a case study.

In addition to conducting life cycle assessments (LCA) of almond processing, wheat flour production, and dried apple processing, this dissertation aims to create a framework to bridge the gap between sustainability and food safety. …

Modeling, Synthesis, And Experimental Characterization Of Rhenium Disulfide For Optoelectronic Devices, Solomon Opeyami Ojo

Graduate Theses and Dissertations

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have garnered considerable interest for their potential in optoelectronics and photonics owing to their remarkable combination of electronic, optical, and mechanical properties. These characteristics distinguish them from other 2D materials, including graphene, making them particularly valuable for next-generation technologies. This dissertation focuses on ReS_₂, a 2D TMD with a unique anisotropic 1T distorted crystal structure. The research aims to elucidate its fundamental properties through a combination of theoretical modeling, material synthesis, and experimental characterization techniques, with the goal of optimizing ReS_₂ for device applications. A theoretical investigation utilizing Density Functional Theory …

Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro

Graduate Theses and Dissertations

Today’s world of electronics is dominated by semiconductor devices which utilize silicon as their substrate material. Though, silicon is not ideal for semiconductor devices in high-voltage or high-temperature applications. Additionally, the efficiency of silicon devices becomes drastically reduced in nonideal operating conditions. Therefore, finding alternatives to silicon?based devices has been a topic for decades now. A few great candidates to replace silicon devices for said applications include Silicon Carbide (SiC), Gallium Nitride (GaN), and Aluminum Arsenide (AlAs). SiC has grown its reputation as the best candidate, when compared to other potential alternatives, due to its wide bandgap, high operating frequency, …

Gate Driver Design In High-Temperature Cmos Process For Heterogeneous Integration Inside Sic Power Module, Khandoker Asif Faruque

Graduate Theses and Dissertations

The shift toward electrification in transportation, including electric and hybrid vehicles, presents challenges for power electronic converters. Silicon Carbide (SiC) power devices are promising due to their high efficiency, temperature tolerance, and reduced losses compared to traditional silicon devices. However, their use is hindered by issues such as parasitic capacitances and gate inductances, which can lead to voltage spikes and stress on the device gate oxide, hence impacting converter reliability. Increasing gate resistance can help manage these issues, but it reduces switching speed and increases losses. Snubber circuits can mitigate switching stress but add extra components, reducing efficiency. Active gate …

A Cmos Ldo Voltage Regulator For Low Power Applications, Nicolaus Vail

Graduate Theses and Dissertations

This thesis presents the design, simulation, layout, and testing of a low dropout linear voltage regulator (LDO) in a 180 nm CMOS process. The LDO is intended for use in low-power, battery-operated applications, and it has an adjustable output for a variety of different implementations. It can supply up to 100 mA of current, which is enough to power many small electronic circuits. It has a dropout voltage of 150 mV, and it consumes less than 200 μA of current during operation, which is on par with many commercial regulators. The line regulation is also comparable to commercially available LDOs, …

Synthesis And Process Optimization Of Cellulose Nanocrystals From Miscanthus X. Giganteus For Commercial Viability, Jaspreet Kaur

Graduate Theses and Dissertations

Cellulose nanocrystals (CNCs), derivatives of an abundant biopolymer, i.e., cellulose, are emerging as promising alternatives to petrochemical-based products due to their unique properties, including biodegradability, low toxicity, high strength, low density, large surface area and low coefficient of expansion. CNCs have diverse applications ranging from food packaging and textiles to drug delivery and medical implants, etc. Despite their potential, the widespread commercialization of CNCs faces significant hurdles owing to the high environmental burden and production costs. They are mainly driven by the commonly used source utilized for CNC synthesis i.e., wood and the intensive synthesis process i.e., requirement of …

Development Of A Manifold Microchannel Heat Sink For The Electrification Of Aircraft, Joshua Mora Sanchez

Mechanical Engineering Undergraduate Honors Theses

The miniaturization of microprocessors and power electronics is leading to critical thermal management challenges. For instance, the heat flux generated in modern computer chips is at the order of 100W/cm², which is well beyond the limit of air cooling. This high heat generation can cause a variety of thermal or mechanical failures in electronic devices. As such, there is a pressing need to devise effective cooling strategies for these microelectronic devices. Liquid cooling with microchannel heat sinks is a promising technology for high power loads. Nevertheless, traditional heat sinks with straight microchannels suffer from two critical challenges: high pressure drop …

Investigating Functionalized Cvd Graphene Heterostructures As Platforms For Hydrogen Gas Sensing, Evans Asiedu Addo-Mensah

Graduate Theses and Dissertations

The hydrogen economy is rapidly advancing and is poised to become one of the world's largest economies, driven by the abundance of hydrogen gas. Several organizations, particularly in the United States of America, are closely or have been monitoring this development, with rapidly increasing interest. Considering that hydrogen gas has no taste, smell (odor), or color, and very combustible, it’s imperative to develop detectors and sensors capable of rapidly detecting leaks to prevent application disasters. Owing to its extraordinary mechanical and electrical characteristics, graphene is the material that has been studied the most. When combined with hexagonal boron nitride (hBN), …

Multimodal Spectroscopy To Study Tumor Microenvironmental Changes In Vivo, April Mordi

Graduate Theses and Dissertations

Every year there are millions of new cancer diagnoses and deaths worldwide. While great strides have been made in technologies and drugs for cancer treatment, there is still a need to understand tumor response to therapy as many patients still endure treatment failure after completing their treatment regimen. Current clinical imaging techniques for detecting response to therapy are utilized weeks to months after the course of treatment, and present limitations to measuring response during treatment. Optical spectroscopy techniques can help meet this need to determine the response of tumors to treatment as it allows for near real-time in vivo characterization …

Causal Discovery In Time Series Data Using Deep Learning Techniques, Saima Zahin Farhana Absar

Graduate Theses and Dissertations

Causal structure learning from observational data has been an active field of research over the past decades. In the literature, different algorithms and models have been proposed, such as constrained-based methods and score-based methods including the emerging deep learning-based methods. However, most of the approaches apply to static and non-dynamic data only. In many applications, the data is temporal. For example, monitoring systems, weather surveillance systems, and stock data, to name but a few. Incorporating temporal information is an important extension of the causal discovery field. With the growth of observational data these days, the discovery of causal relationships from …

Clusteredlog: Optimizing Log Structures For Efficient Data Recovery And Integrity Management In Database Systems, Mariha Siddika Ahmad, Brajendra Panda

Electrical Engineering and Computer Science Faculty Publications and Presentations

In modern database systems, efficient log management is crucial for ensuring data integrity and facilitating swift recovery from potential data corruption or system failures. Traditional log structures, which store operations sequentially as they occur, often lead to significant delays in accessing and recovering specific data objects due to their scattered nature across the log. ClusteredLog addresses the limitations of traditional logging methods by implementing a novel logical organization of log entries. Instead of simply storing operations sequentially, it groups related operations for each data item into clusters. As a result, ClusteredLog enables faster identification and recovery of damaged data items …

Neural Network Architecture Search Enabled Wide-Deep Learning (Nas-Wd) Integrated Hyperspectral Imaging Understanding For Woody Breast In Poultry Processing, Chaitanya Kumar Reddy Pallerla

Graduate Theses and Dissertations

The development and implementation of a Wide & Deep (WD) learning model tailored for classification and regression tasks utilizing spectral data provides a robust solution to evaluate woody breast (WB) conditions in poultry fillets. This process begins with thorough data preprocessing, which includes loading spectral and classification datasets, imputing missing values with medians, and splitting the data into training and testing sets to ensure rigorous model evaluation. The WD model architecture integrates wide linear models and deep neural networks to harness the strengths of both approaches. The wide component excels at memorizing sparse feature interactions, while the deep component captures …

Two-Photon Imaging For Characterizing Tumor Microenvironmental Changes In Non-Small Cell Lung Cancer Associated With Metastatic Recurrence, Paola Monterroso Diaz

Graduate Theses and Dissertations

Lung cancer remains the leading cause of cancer deaths, comprising nearly 25% of all cancer deaths (Sung et al., 2021a). The five-year survival rate of patients with non-small cell lung carcinoma (NSCLC) remains significantly low given that over half present with locally advanced or metastatic disease at time of diagnosis, and experience tumor recurrence following therapeutic intervention (Tamura et al., 2015; Uramoto & Tanaka, 2014). Current evaluation techniques to assess treatment response are lacking, given they are implemented several weeks after treatment completion and are solely based on anatomical changes in tumor size, forgoing other criteria such as functional or …

Design And Optimization Of Matrix Core Transformer For High Power Bidirectional Isolated Dc/Dc Converter, Zhe Zhao

Graduate Theses and Dissertations

Thanks to the advancement of semiconductor technology, the silicon carbide (SiC) devices with high voltage and power capability are developed and widely used in several industry applications, e.g., gird-connected photovoltaic (PV) system, data center power supply, and electrical vehicle (EV) charging station. After the concept of solid-state transformer (SST) was proposed as an important solution to the medium voltage (MV) power conversion systems, this bidirectional isolated DC/DC converter has attracted much attention in academia and industry. One of the main advantages of SST is to improve both the power density and efficiency of the power conversion system by replacing the …

White Hall Green Roof Proposal, Hope Dwyer

Biological and Agricultural Engineering Undergraduate Honors Theses

This project will propose designs for a GR system while determining the potential cost, the feasibility of the system implementation, as well as potential psychological and educational benefits of a GR system. These factors will be examined and evaluated with regard to two different proposed GR designs: extensive and intensive.

Quantum Visual Feature Encoding Revisited, Xuan-Bac Nguyen, Hoang-Quan Nguyen, Hugh Churchill, Samee U. Khan, Khoa Luu

Computer Science and Computer Engineering Faculty Publications and Presentations

Although quantum machine learning has been introduced for a while, its applications in computer vision are still limited. This paper, therefore, revisits the quantum visual encoding strategies, the initial step in quantum machine learning. Investigating the root cause, we uncover that the existing quantum encoding design fails to ensure information preservation of the visual features after the encoding process, thus complicating the learning process of the quantum machine learning models. In particular, the problem, termed the “Quantum Information Gap” (QIG), leads to an information gap between classical and corresponding quantum features. We provide theoretical proof and practical examples with visualization …

An Automated Design Flow From Synchronous Rtl To Optimized Layout Using Commercial Eda Tools For Multi-Threshold Null Convention Logic Circuits, Cole Harrington Sherrill

Graduate Theses and Dissertations

This work presents the first automated design flow from synchronous RTL to highly optimized layout for Multi-Threshold NULL Convention Logic (MTNCL) circuits. The developed synthesis flow overcomes many of the drawbacks of existing attempts and leverages the advanced optimization features provided by modern synthesis tools. The remaining timing race conditions native to the MTNCL architecture have been identified and thoroughly explored. Two sets of novel timing constraints were devised: the first responds to these race conditions, yielding highly reliable MTNCL circuits; the second directly targets the critical paths within MTNCL circuits, allowing the designer to optimize the target circuit for …