Digital Commons Network^™

Single Asperity Fretting Corrosion Of Traditional And Additively Manufactured Metallic Biomaterials: Quantitative Analysis From Acetabular Tapers To Micron And Nanometer Scale Tribocorrosion, Annsley Mace

All Dissertations

Mechanically assisted crevice corrosion (MACC) of metallic biomaterials continues to be a significant degradation mode. This is, in part, due to a lack of understanding of fundamental micron- and sub-micron scale mechanisms of metal degradation in biological environments. Metal-metal (or metal-hard) load bearing surfaces of hip arthroplasties are subjected to fretting crevice corrosion (FCC, one form of MACC). Current work in tribocorrosion involves large contact area tests with multiple asperities, with a distribution of load and wear that changes over time. A more systematic and controlled study of the FCC micro- and nanomechanics is needed.

Therefore, the goal of this …

Analyzing Vulnerabilities In The Northwest Arkansas Highway Network Using Mathematical Optimization, Brandon Jerome

Industrial Engineering Undergraduate Honors Theses

The highway and bridge network is a critical infrastructure that allows for the free transportation of citizens and enables truck-borne freight transportation. Disruption of this system could be caused by a terrorist attack, natural disaster, growth of population, required repairs and upgrades, or collapse caused by old age or malfunction. In the event of a disruption cities and regions can experience increased traffic and supply chain shortages, thus causing cascading effects throughout surrounding areas. With this motivation, we develop a network interdiction optimization model to identify a limited subset of roads that, if disrupted, causes the greatest increase in the …

Atomic Force Microscopy Based Dna Sensing And Manipulation, Matthew Shubert

Mechanical Engineering Undergraduate Honors Theses

Sequencing DNA provides a positive impact for the biomedical community by understanding a wide variety of applications such as human genetics, disease, and pathogens. The reason the Arkansas Micro & Nano Systems lab is involved with research in DNA sequencing is due to the current, leading industry method. Nanopore sequencing was developed by Oxford Nanopore Technology in which its sequencing method separates double stranded DNA to electrically characterize individual nucleotides traveling through a charged nanopore. Unfortunately, nanopore sequencing uses biological materials that require a shelf life and drives high cost. Therefore, the Arkansas Micro & Nano Systems lab has developed …

Deep Learning Object-Based Detection Of Manufacturing Defects In X-Ray Inspection Imaging, Juan C. Parducci

Mechanical & Aerospace Engineering Theses & Dissertations

Current analysis of manufacturing defects in the production of rims and tires via x-ray inspection at an industry partner’s manufacturing plant requires that a quality control specialist visually inspect radiographic images for defects of varying sizes. For each sample, twelve radiographs are taken within 35 seconds. Some defects are very small in size and difficult to see (e.g., pinholes) whereas others are large and easily identifiable. Implementing this quality control practice across all products in its human-effort driven state is not feasible given the time constraint present for analysis.

This study aims to identify and develop an object detector capable …

A Preventive Medicine Framework For Wearable Abiotic Glucose Detection System, Saikat Banerjee

Electrical & Computer Engineering Theses & Dissertations

In this work, we present a novel abiotic glucose fuel cell with battery-less remote access. In the presence of a glucose analyte, we characterized the power generation and biosensing capabilities. This system is developed on a flexible substrate in bacterial nanocellulose with gold nanoparticles used as a conductive ink for piezoelectric deposition based printing. The abiotic glucose fuel cell is constructed using colloidal platinum on gold (Au-co-Pt) and a composite of silver oxide nanoparticles and carbon nanotubes as the anodic and cathodic materials. At a concentration of 20 mM glucose, the glucose fuel cell produced a maximum open circuit voltage …

Investigating Arrhythmia Potential In Cardiac Myocytes In Presence Of Long Qt Syndrome, Victoria Lin Lam

Biomedical Engineering Theses & Dissertations

Long QT Syndrome (LQTS) is an increasingly studied condition that leads to potentially fatal heart rhythm disorders, called arrhythmias, and sudden cardiac death. The alterations in the electrocardiograms (ECGs) seen in LQTS patients is caused by mutations to genes related to ion channels in cardiac cells. Computational modeling allows the mechanistic study of these ion channel mutations in LQTS by providing quantitative predictors of cardiac behavior in human and rabbit heart models. This work hypothesizes that the repolarization reserve in cardiac Purkinje cells (PC), that form the cardiac conduction system, is lower than that of ventricular myocytes (VM), resulting in …

Development Of Modeling And Simulation Platform For Path-Planning And Control Of Autonomous Underwater Vehicles In Three-Dimensional Spaces, Sai Krishna Abhiram Kondapalli

Mechanical & Aerospace Engineering Theses & Dissertations

Autonomous underwater vehicles (AUVs) operating in deep sea and littoral environments have diverse applications including marine biology exploration, ocean environment monitoring, search for plane crash sites, inspection of ship-hulls and pipelines, underwater oil rig maintenance, border patrol, etc. Achieving autonomy in underwater vehicles relies on a tight integration between modules of sensing, navigation, decision-making, path-planning, trajectory tracking, and low-level control. This system integration task benefits from testing the related algorithms and techniques in a simulated environment before implementation in a physical test bed. This thesis reports on the development of a modeling and simulation platform that supports the design and …

Pedestrian Evacuation: Vulnerable Group Member Influence On The Group Leaders’ Decision-Making And The Impact On Evacuation Time, Terra Lynne Elzie

Computational Modeling & Simulation Engineering Theses & Dissertations

As pedestrian evacuations of buildings, outdoor venues, and special events occur, dynamic interactions between pedestrians and vehicles during egress are possible. To model pedestrian and vehicle evacuations, simulation models have evolved to incorporate more realistic crowd characteristics and behaviors to provide improved results. Past studies using modeling and simulation, specifically agent-based modeling, have explored pedestrian behaviors such as decision-making, navigation within a virtual environment, group formations, intra-group interactions, inter-group dynamics, crowd behaviors such as queuing and herding, and pedestrianvehicle interactions. These studies have led to relevant insights helpful to improving the accuracy of evacuation times for normal and emergency egress …

Complex System Governance Leadership, David C. Walters

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to develop a systems theory-based framework for leadership in governance of complex systems. Recognizing complexity and uncertainty as norms for the environments in which organizations exist encouraged researchers to suggest complexity theory, complex systems, and complex adaptive systems as appropriate for addressing these conditions. Complex System Governance (CSG), based in systems theory, management cybernetics, and governance, endeavors to provide for the design, execution and evolution of functions that provide control, communication, coordination, and integration at the metasystem level to support operations and continued system existence (viability). From a management cybernetics perspective, CSG leadership has …

On The Thermogravimetric Analysis Of Polymers: Polyethylene Oxide Powder And Nanofibers, Oriretan Omosola, Dorina M. Chipara, Mohammed Jasim Uddin, Karen Lozano, Mataz Alcoutlabi, Victoria Padilla-Gainza, Mircea Chipara

Mechanical Engineering Faculty Publications

Thermogravimetric analysis of polyethylene oxide (powder and nanofibers obtained by force spinning water or chloroform solutions of polyethylene oxide) was studied using different theoretical models such as Friedman and Flynn-Wall-Ozawa. A semiempirical approach for estimating the “sigmoid activation energy” from the thermal degradation was suggested and confirmed by the experimental data on PEO powder and nanofibers' mats. The equation allowed for calculating a “sigmoid activation energy” from a single thermogram using a single heating rate without requiring any model for the actual complex set of chemical reactions involved in the thermal degradation process. For PEO (powder and nanofibers obtained from …

Desalination Waste Revitalization Using Carbon Capture: Process Optimization Using Machine Learning, Ahmed Mohamed Elsayed

Theses

Over the next five to ten years, desalination will play an ever-important role in our society. Developing nations will look at desalination from the point of water scarcity, while developed nations will consider the perspective of the Water-Energy-Food nexus. With current technology, for every liter of freshwater produced, one and a half liters is thrown away as waste. This body of research proposes to employ chemical precipitation in ammoniated brine solutions, that have reasonably high ionic concentrations. CO2 absorption in Bubble Column Reactors can reduce sodium ions by precipitating NaHCO3. Also, the absorbed CO2 can reduce chloride ions and induce …

Membrane Bioreactor For Enhanced Enzymatic Hydrolysis Of Cellulose, Saleha Abdullah Al-Mardeai

Dissertations

With the rising environmental concerns related to fossil fuels utilization and the depletion of these resources, interest in bioethanol from lignocellulosic waste as an alternative, sustainable energy source has been increasing. Date palm waste is considered a good feedstock for bioethanol production, especially in countries of large date palm plantations, such as the United Arab Emirates.

In the lignocellulose to bioethanol process, the enzymatic hydrolysis of celluloses to produce simple sugars that can be converted to bioethanol by fermentation is the most challenging step, and enhancing it is essential for efficient and feasible operation. Enzyme inhibition by the products is …

Understanding The Role Of Nano-Tio2 On The Toxicity Of Pb On C. Dubia Through Modeling—Is It Additive Or Synergistic?, Xuesong Liu, Jianmin Wang, Yue-Wern Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Nano-TiO₂ can remarkably increase lead (Pb) toxicity in aquatic organisms. However, the mechanism of this toxicity, additive or synergistic, is not well understood. To explore this mechanism, we inspected the role of nano-TiO₂ in the toxicity of Pb on Ceriodaphnia dubia (C. dubia), a model water flea species typically used for ecotoxicity studies. The effect of algae, a diet for aquatic organisms, on the effect of this binary mixture was also investigated. A two-compartment toxicokinetic (TK)-toxicodynamic (TD) modeling approach was used to quantify the Pb toxicity under these complex conditions and to develop critical parameters for understanding the …

Review Of Biomechanical Studies And Finite Element Modeling Of Sternal Closure Using Bio-Active Adhesives, Amatulraheem Al-Abassi, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The most common complication of median sternotomy surgery is sternum re-separation after sternal fixation, which leads to high rates of morbidity and mortality. The adhered sternal fixation technique comprises the wiring fixation technique and the use of bio-adhesives. Adhered sternal fixation techniques have not been extensively studied using finite element analysis, so mechanical testing studies and finite element analysis of sternal fixation will be presented in this review to find the optimum techniques for simulating sternal fixation with adhesives. The optimal wiring technique should enhance bone stability and limit sternal displacement. Bio-adhesives have been proposed to support sternal fixation, as …

Establishing Pteridine Metabolism In A Progressive Isogenic Breast Cancer Cell Model – Part Ii, Lindsey Rasmussen, Zachary Foulks, Jiandong Wu, Casey Burton, Honglan Shi

Chemistry Faculty Research & Creative Works

Introduction: Determining the biological significance of pteridines in cancer development and progression remains an important step in understanding the altered levels of urinary pteridines seen in certain cancers. Our companion study revealed that several folate-derived pteridines and lumazines correlated with tumorigenicity in an isogenic, progressive breast cancer cell model, providing direct evidence for the tumorigenic origin of pteridines. Objectives: This study sought to elucidate the pteridine biosynthetic pathway in a progressive breast cancer model via direct pteridine dosing to determine how pteridine metabolism changes with tumorigenicity. Methods: First, MCF10AT breast cancer cells were dosed individually with 15 pteridines to determine …

Identification Of Orthologous Gene Groups Using Machine Learning, Dillon Burgess

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Identification of genes that show similarity between different organisms, a.k.a orthologous genes, is an open problem in computational biology. The purpose of this thesis is to create an algorithm to group orthologous genes using machine learning. Following an optimization step to find the best characterization based on training data, we represented sequences of genes or proteins with kmer vectors. These kmer vectors were then clustered into orthologous groups using hierarchical clustering. We optimized the clustering phase with the same training data for the method and parameter selection. Our results indicated that use of protein sequences with k=2 and scaling the …

Assessment Of Manure Treatment Technology Adoption And Feedlot Runoff Monitoring Opportunities, Juan Carlos Ramos Tanchez

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Livestock products contain valuable nutrients that enhance human health, and their production generates positive local and national economic impacts. The livestock sector also deals with large quantities of environmentally important nutrients in manure. The purpose of this thesis is to further the aims of researchers and educators working at the intersection of livestock production and the environment to identify and promote best practices for livestock production and manure management that are economically and environmentally sustainable.

The second chapter explored options to evaluate nutrient flows in feedlot runoff at the pen scale. Pen scale monitoring is an important consideration for research …

Study On Electrochemical Conversion Of Ammonium Sulfate To Ammonium Persulfate In Acetylpyrazine Wastewater, Yi-Jie Wang, Dong-Fang Niu, Xin-Sheng Zhang

Journal of Electrochemistry

Acetylpyrazine is an important spice and also plays important roles in biology, medicine and other fields. However, the wastewater containing ammonium persulfate, ferric ion (Fe³⁺), pyrazine, and a large amount of ammonium sulfate was produced during the production of acetylpyrazine. In this study, ammonium sulfate in acetylpyrazine wastewater was electrolytically converted into ammonium persulfate for economic benefits. Using platinum as an anode and graphite as a cathode, the influence factors of the electrolysis process (including the composition of the anolyte, the current density, the temperature, etc.) were firstly investigated without interference from other compositions. Under the optimal condition, …

Tuning The Physicochemical, Structural, And Antimicrobial Attributes Of Whey-Based Poly (L-Lactic Acid) (Plla) Films By Chitosan Nanoparticles, Farhad Garavand, Milad Rouhi, Shima Jafarzadeh, Diako Khodaei, Ilaria Cacciotti, Masoumeh Zargar, Seyed Hadi Razavi

Research outputs 2022 to 2026

Recently, the research and innovation to produce raw materials from microbial processes has gained much attention due to their economic and environmental impacts. Lactic acid is a very important microbial product due to its wide application in the food, pharmaceutical, cosmetic, and chemical industries. In the current study, poly (L-lactic acid) (PLLA) was produced by the ring opening polymerization (ROP) technique of L-lactic acid recovered from whey fermentation, and was used for the production of nanocomposites films reinforced with chitosan nanoparticles (CNPs) (average diameter ca. 100–200 nm). Three different CNPs concentrations, namely 1, 3, and 5% w/w, were tested, and …

Acoustofluidics For Simultaneous Nanoparticle-Based Drug Loading And Exosome Encapsulation, Zeyu Wang, Joseph Rich, Nanjing Hao, Yuyang Gu, Chuyi Chen, Shujie Yang, Peiran Zhang, Tony Jun Huang

Faculty Publications

Nanocarrier and exosome encapsulation has been found to significantly increase the efficacy of targeted drug delivery while also minimizing unwanted side effects. However, the development of exosome-encapsulated drug nanocarriers is limited by low drug loading efficiencies and/or complex, time-consuming drug loading processes. Herein, we have developed an acoustofluidic device that simultaneously performs both drug loading and exosome encapsulation. By synergistically leveraging the acoustic radiation force, acoustic microstreaming, and shear stresses in a rotating droplet, the concentration, and fusion of exosomes, drugs, and porous silica nanoparticles is achieved. The final product consists of drug-loaded silica nanocarriers that are encased within an …

2021-2022 Program And Abstracts: Celebration Of Student Scholarship, Morehead State University. Undergraduate Research Fellowship Program.

2022 Celebration of Student Scholarship - Poster Presentations

The 2021-2022 Program and Abstracts for the Celebration of Student Scholarship at Morehead State University held on April 27, 2022. A Showcase of Student Research, Scholarship, Creative Work, and Performance Arts.

Students Interest And Thoughts On Stem, Chrisitine Girtain

STEM Month

I am Juan Sebastian Bohorquez Mora, I am a sophomore student at Toms River High School North. I am interested in biofuels because I believe they are a good option to replace fossil fuels. I am also interested in duckweed because biofuels are made out of crops, and people need to eat those crops. That’s when duckweed comes in and it can be used as a feedstock for ethanol production which is a biofuel. Bioethanol is a type of biofuel and it is derived from the corn’s starch. Instead of making ethanol from the corn’s starch, we can use duckweed …

Neuromorphic Computing Using Electrostatic Mems Devices, Fadi Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

A continuous - time recurrent neural network ( CTRNN ) is described that exploits the nonlinear dynamics of micro electro - mechanical system ( MEMS ) devices to model a neuron in accordance with a neuron rate model that is the basis for dynamic field theory . Each MEMS device in the CTRNN is configured to simulate a neuron population by exploiting the characteristics of bi - stability and hysteresis inherent in certain MEMS device structures . In an embodiment , the MEMS device is a microbeam or cantilevered microbeam device that is excited with an alternating current ( AC …

Characterizing And Predicting Human Visual Perception Of Unmanned Aerial Vehicle Gestures, Paul Fletcher

School of Computing: Dissertations, Theses, and Student Research

Unmanned Aerial Vehicles (UAVs) are being used in public domains and hazardous environments where effective communication strategies are critical. UAV gesture techniques have been shown to communicate meaning to human observers and may be ideal in contexts that require lightweight systems such as unmanned aerial flight, however, this work may be limited to an idealized range of viewer perspectives. As gesture is a visual communication technique it is necessary to consider how the perception of a robot gesture may suffer from obfuscation or self-occlusion from some viewpoints. This thesis presents the results of three online user-studies that examine participants’ ability …

Effective Parameters Controlling Sterol Transfer: A Time‑Resolved Small‑Angle Neutron Scattering Study, Ursula Perez-Salas, Lionel Porcar, Sumit Garg, Manuela A.A. Ayee-Leong, Irena Levitan

Faculty Work Comprehensive List

Though cholesterol is the most prevalent and essential sterol in mammalian cellular membranes, its precursors, post-synthesis cholesterol products, as well as its oxidized derivatives play many other important physiological roles. Using a non-invasive in situ technique, time-resolved small angle neutron scattering, we report on the rate of membrane desorption and corresponding activation energy for this process for a series of sterol precursors and post-synthesis cholesterol products that vary from cholesterol by the number and position of double bonds in B ring of cholesterol’s steroid core. In addition, we report on sterols that have oxidation modifications in ring A and ring …

Identification Of Return-Oriented Programming Attacks Using Risc-V Instruction Trace Data, Daniel F. Koranek, Scott R. Graham, Brett J. Borghetti, Wayne C. Henry

Faculty Publications

An increasing number of embedded systems include dedicated neural hardware. To benefit from this specialized hardware, deep learning techniques to discover malware on embedded systems are needed. This effort evaluated candidate machine learning detection techniques for distinguishing exploited from non-exploited RISC-V program behavior using execution traces. We first developed a dataset of execution traces containing Return Oriented Programming (ROP) exploitation on the RISC-V Instruction Set Architecture (ISA) and then developed several deep learning bidirectional Long Short-Term Memory (LSTM) models capable of distinguishing exploited traces from non-exploited traces, each using subsets of features from the execution traces. An objective of this …

Mechanobiology In The Comorbidities Of Ehlers Danlos Syndrome, Shaina P. Royer, Sangyoon J. Han

Michigan Tech Publications, Part 1

Ehlers-Danlos Syndromes (EDSs) are a group of connective tissue disorders, characterized by skin stretchability, joint hypermobility and instability. Mechanically, various tissues from EDS patients exhibit lowered elastic modulus and lowered ultimate strength. This change in mechanics has been associated with EDS symptoms. However, recent evidence points toward a possibility that the comorbidities of EDS could be also associated with reduced tissue stiffness. In this review, we focus on mast cell activation syndrome and impaired wound healing, comorbidities associated with the classical type (cEDS) and the hypermobile type (hEDS), respectively, and discuss potential mechanobiological pathways involved in the comorbidities.

Development Of A Bio-Inspired Artificial Butterfly Vehicle, Thomas Payne Clark

Honors Capstone Projects and Theses

No abstract provided.

Efficient Low Dimensional Representation Of Vector Gaussian Distributions, Md Mahmudul Hasan

LSU Doctoral Dissertations

This dissertation seeks to find optimal graphical tree model for low dimensional representation of vector Gaussian distributions. For a special case we assumed that the population co-variance matrix $\Sigma_x$ has an additional latent graphical constraint, namely, a latent star topology. We have found the Constrained Minimum Determinant Factor Analysis (CMDFA) and Constrained Minimum Trace Factor Analysis (CMTFA) decompositions of this special $\Sigma_x$ in connection with the operational meanings of the respective solutions. Characterizing the CMDFA solution of special $\Sigma_x$, according to the second interpretation of Wyner's common information, is equivalent to solving the source coding problem of finding the minimum …

Estimating Animal Pose Using Deep Learning A Trained Deep Learning Model Outperforms Morphological Analysis, Sanghoon Lee, Jarod Banzon, Kevin Le, Dal Hyung Kim

Computer Sciences and Electrical Engineering Faculty Research

INTRODUCTION: Analyzing animal behavior helps researchers understand their decision-making process and helper tools are rapidly becoming an indispensable part of many interdisciplinary studies. However, researchers are often challenged to estimate animal pose because of the limitation of the tools and its vulnerability to a specific environment. Over the years, deep learning has been introduced as an alternative solution to overcome these challenges.

OBJECTIVES: This study investigates how deep learning models can be applied for the accurate prediction of animal behavior, comparing with traditional morphological analysis based on image pixels.

METHODS: Transparent Omnidirectional Locomotion Compensator (TOLC), a tracking device, is used …