Engineering Commons^™

Linking Molecular Structure Evolution To Mechanical Degradation During Environmental Aging In Conventional And Recyclable Epoxy Systems, Ben T. Jewell

Dissertations, Master's Theses and Master's Reports

The long-term performance of polymeric materials in extreme environments is governed by complex chemical and physical aging processes that alter their molecular structure and mechanical integrity. Conventional thermoset epoxies, while widely used in structural applications, are particularly susceptible to oxidative degradation at elevated temperatures, leading to embrittlement and loss of structural integrity. In the first part of this work, diffusion-limited oxidation (DLO) in a bulk structural epoxy was systematically investigated to establish the link between heterogeneous microstructural evolution and macroscopic mechanical degradation. High-temperature oxidation experiments were conducted in a controlled environmental chamber, and the resulting chemical, thermal, and mechanical changes …

Degradation Of Polymers And Polymer Composites In Extreme Environments, Ben T. Jewell

Dissertations, Master's Theses and Master's Reports

Polymeric materials are widely used in engineering applications due to their high strength-to-weight ratio, easy manufacturability, and cost-effectiveness. When incorporated into composites, they provide further performance enhancements, enabling use in demanding structural applications. However, long-term exposure to harsh environments including elevated temperatures, UV radiation, harsh chemicals, and radiation, can drive degradation processes that alter the material’s network structure, and in turn, degrade its mechanical performance. Exposure to thermo-oxidative conditions is one of the most common environments driving polymer degradation, leading to chain scission and crosslinking events, with the resulting oxidative products causing discoloration, reduced ductility, and changes in glass transition …

A Statistical Analysis For Evaluating The Parameters Influencing The Rutting And Cracking Performance Of Asphalt Mixtures, Alexis Light, Mohammad Tahir Ansari, Andrew F. Braham

2025 Research Poster Competition

Durable pavement is essential for modern transportation infrastructure, especially in the United States of America which boasts over 8.5 million lane miles of roads and highways. Despite advanced construction techniques, asphalt pavements are susceptible to rutting and cracking, significantly affecting their performance and maintenance costs. Current methods for analyzing rutting and cracking in asphalt mixtures rely on various parameters, leading to measurement variability. This highlights the need for more rigorous analysis to explore the relationship between mix design variables and pavement performance. This research explores the IDEAL-CT and Asphalt Pavement Analyzer (APA) data from mix designs collected by the Arkansas …

A Century Of Sediment Metal Contamination Of Mar Menor, Europe's Largest Saltwater Lagoon, Irene Alorda-Montiel, Valentí Rodellas, Ariane Arias-Ortiz, Albert Palanques, Andrea G. Bravo, Júlia Rodriguez-Puig, Aaron Alorda-Kleinglass, Carlos Green-Ruiz, Marc Diego-Feliu, Pere Masqué, Javier Gilabert, Jordi Garcia-Orellana

OES Faculty Publications

Coastal enclosed ecosystems, such as lagoons, are vulnerable to anthropogenic impacts because they favor the accumulation of contaminants from the surrounding watersheds, particularly in their sediments. Europe's largest saltwater lagoon, the Mar Menor (SE, Iberian Peninsula), is a highly impacted ecosystem and the first in the continent to be granted personhood rights. Based on a high-resolution spatial and temporal dataset, we present the historical reconstruction of metal contamination in this ecosystem during the last century. Our results highlight that sediment metal contamination has been mainly driven by the development of the mining industry in the nearby Sierra Minera de Cartagena-La …

Ensemble Machine Learning Approaches For Bathymetry Estimation In Multi-Spectral Images, Kazi A. Islam, Omar Abdul-Hassan, Hongfang Zhang, Victoria Hill, Blake Schaeffer, Richard Zimmerman, Jiang Li

OES Faculty Publications

Traditional bathymetry measures require a large number of human hours, and many bathymetry records are obsolete or missing. Automated measures of bathymetry would reduce costs and increase accessibility for research and applications. In this paper, we optimized a recent machine learning model, named CatBoostOpt, to estimate bathymetry based on high-resolution WorldView-2 (WV-2) multi-spectral optical satellite images. CatBoostOpt was demonstrated across the Florida Big Bend coastline, where the model learned correlations between in situ sound Navigation and Ranging (Sonar) bathymetry measurements and the corresponding multi-spectral reflectance values in WV-2 images to map bathymetry. We evaluated three different feature transformations as inputs …

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, …

Addressing The Barriers To Peritoneal Dialysis-Visual Appeal Matters, Sam Stephens, Larissa Whale, Makenzie Kapales, Fatima Ayub, Morten O. Jensen, Manisha Singh

Biomedical Engineering Faculty Publications and Presentations

Peritoneal dialysis (PD) is an effective renal replacement strategy for patients with end-stage renal disease utilizing the peritoneum as the filter and PD catheter as access. A survey of PD patients showed that some felt uncomfortable with the length of current catheters and would be interested to explore newer, shorter designs. We redesigned the transfer set and external portion of the catheter, addressing this barrier as a part of our multi-institutional design project led by a nephrologist from the University of Arkansas for Medical Sciences (UAMS) and an engineering design team from the biomedical engineering department at the University of …

Reducing Friction In Machine Oil Via Cesium-Hybridized Graphene Oxide Quantum Dot Additives, Islam Gomaa, Sherief Elsoudy, Maryam Galal, Ahmed Azim

Nanotechnology Research Centre

Friction and wear are among the most common causes of energy loss and component failure in mechanical systems, accounting for around 20–30% of total global energy consumption. Conventional lubricants fail to provide consistent performance in harsh conditions due to inadequate additive dispersion, agglomeration, and restricted surface reactivity. Recent advances in nanomaterial-based lubricants have shown promise, but it remains difficult to achieve significant friction and wear reduction at low additive concentrations while preserving stability. In this study, we synthesized and tested cesium-hybridized graphene oxide quantum dots (Cs-GOQDs) as novel lubricant additives. When incorporated into machine oil at 0.1 wt%, Cs-GOQDs reduced …

Experimental And Computational Analysis Of Pfas Adsorption And Transport Through A Soil-Bentonite Cutoff Wall Amended With Activated Carbon, Leeann B. Michael

Master’s Theses

Due to their toxicity, prevalence, and persistence in the environment, poly- and perfluoroalkyl substances (PFAS) pose a significant threat to human health and ecological systems. When conventional groundwater remediation methods are ineffective for PFAS, in situ containment using engineered vertical barriers (cutoff walls) becomes a potentially viable alternative. This research investigates the efficacy of soil-bentonite (SB) cutoff walls amended with granular activated carbon (GAC) for long-term PFAS containment in groundwater. The focus of this work is characterizing PFAS adsorption onto the mixed matrix for determination of isotherm parameters for modeling. Along the way, considerations for sample handling were investigated to …

Same Dynamics, Different Graph: Exploring Correlations, Similarities, And Renormalization Of Dynamics On Networks Using Temporal Distance Theory, Matthew Hockenbrock

Master’s Theses

Analyzing dynamics that take place on graphs (networks) is fundamental to modern network theory, with applications spanning biology, social networks, and engineering systems. A significant body of research exists that considers the similarity and scaling of network topologies. However, understanding how dynamic behavior varies across different graph topologies - particularly how signals propagate and dynamic behaviors scale between small and large networks - remains a significant challenge.

To address this challenge, this thesis presents a comprehensive framework to analyze how dynamic signals propagate and scale on network topologies using temporal distance theory. Three research goals were accomplished. First, a …

Transformer-Based Symbolic Music Generation, Ben Buentello

Master’s Theses

This thesis investigates the capacity of transformer-based architectures to learn generalized musical patterns through symbolic generation. To support this exploration, a complete music generation pipeline was developed, beginning with the construction and classification of a large-scale dataset of over 170,000 MIDI files. The dataset was processed using rule-based heuristics and custom neural classifiers to separate tracks by musical function and contour. A novel tokenization scheme, MINTii, was introduced to encode musical information compactly through interval-based representations, reducing redundancy and promoting generalization. Using this infrastructure, a transformer model was trained to generate single-track melodic sequences. Its performance was evaluated through both …

Supercapacitors With Cotton Shell-Derived Activated Carbons And Porous Polymer Electrolyte Films, Saurabh Singh, Yulin Zhang, S. A. Hashmi, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Some of the well-known challenges in the field of supercapacitors (SCs), or more specifically, electrical double-layer capacitors (EDLCs), such as low energy density and high cost, have proven to be major barriers to their widespread market success despite having some excellent electrochemical merits such as high-power density and good cyclic stability. In this work, efforts have been made to overcome these gaps and eventually enhance the performance of EDLCs via a cost-effective and eco-friendly approach. To fabricate these EDLCs, a bio-waste, namely, cotton-shell-derived activated carbons (ZnACs) (activated with ZnCl2), was used in a mass ratio of 1 : 2 for …

Improvement Of Cellular Pattern Organization And Clarity Through Centrifugal Force, Lauren E. Mehanna, James D. Boyd, Shelley Remus-Williams, Nicole M. Racca, Dawson P. Spraggins, Martha E. Grady, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

Rapid and strategic cell placement is necessary for high throughput tissue fabrication. Current adhesive cell patterning systems rely on fluidic shear flow to remove cells outside of the patterned regions, but limitations in washing complexity and uniformity prevent adhesive patterns from being widely applied. Centrifugation is commonly used to study the adhesive strength of cells to various substrates; however, the approach has not been applied to selective cell adhesion systems to create highly organized cell patterns. This study shows centrifugation as a promising method to wash cellular patterns after selective binding of cells to the surface has taken place. After …

Integrating Protein Language Model And Molecular Dynamics Simulations To Discover Antibiofouling Peptides, Ibrahim A. Imam, Shea Bailey, Duolin Wang, Shuai Zeng, Dong Xu, Qing Shao

Chemical and Materials Engineering Faculty Publications

Antibiofouling peptide materials prevent the nonspecific adsorption of proteins on devices, enabling them to perform their designed functions as desired in complex biological environments. Due to their importance, research on antibiofouling peptide materials has been one of the central subjects of interfacial engineering. However, only a few antibiofouling peptide sequences have been developed. This narrow scope of antibiofouling peptide materials limits their capacity to adapt to the broad spectrum of application scenarios. To address this issue, we searched for antibiofouling peptides in the vast sequence pool of the microbiome library using a combination of deep learning-based high-throughput search and molecular …

Clarifying The Role Of Η-Phase With Varying Chemistry On Localised Corrosion Of A Cu-Containing 7xxx Al-Alloy By Quasi-In-Situ Tem, S. K. Kairy, Y. Wu, S. Turk, A. Shekhter, Rudolph Buchheit, N. Birbilis

Chemical and Materials Engineering Faculty Publications

Quasi-in-situ transmission electron microscopy was employed to study dissolution associated with η-phase (Mg(Zn,Al,Cu)₂) precipitates in a Cu-containing 7xxx Al-alloy. Two distinct η-phase chemistries, with Cu to (Zn+Mg+Al) ratios ∼0.12 and ∼0.2, were studied in 0.01 M NaCl at pH 6 and 2. In near-neutral NaCl, both η-phase precipitates exhibited ‘duplex’ behaviour, i.e., they were primarily more noble with respect to the surrounding Al-matrix, causing matrix dissolution, and simultaneously established nanoscopic active sites within the noble precipitate itself by generating nanoscale pits. Conversely, η-phase precipitates rapidly dealloyed in acidic NaCl, forming nocrystalline Cu remnants containing twins, which subsequently caused …

Enhancing Intrinsic Ductility In Vnbmotaw High Entropy Alloy: A Combinatorial Investigation With Experimental Evaluation Of Theoretical Predictions, Taohid Bin Nur Tuhser, Ian Stewart Winter, Daryl Chrzan, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

The application of refractory high entropy alloys (RHEAs) as engineering materials has been hindered by their poor inherent ductility. In this study, a novel approach combining thin film combinatorial screening with fragmentation testing was employed to identify intrinsically ductile alloy compositions. Inspired by the physics-based intrinsic ductility parameter, the ‘χ-parameter,’ we investigated the replacement of group VI elements (W/Mo) with group V elements (V, Nb, Ta) in the VNbMoTaW system. Conventional combinatorial analyses, including composition, phase, and hardness assessments, were conducted across a wide range of non-equiatomic configurations. The results revealed a broad compositional space favoring a single-phase body-centered cubic …

Engagement In Practice: Partnering With Communities To Address Nuisance Flooding Challenges, Carol L. Considine, Mujde Erten-Unal, Dalya Ismael, Luka Alandra Hamal-Serenity, Farzaneh Soflaei

Engineering Technology Faculty Publications

Many communities are already experiencing the impacts of climate change that disrupt their daily lives. In Coastal Virginia, these impacts take the form of nuisance and stormwater flooding caused by sea level rise and changes in precipitation. Coastal Virginia has one of the highest relative sea level rise rates on the Atlantic Coast and the regional planning district commission recommends that Atlas 14 rainfall intensity, duration, and frequency curves be increased by 20% to account for changes in rainfall. The Coastal Community Design Collaborative (CCDC), a partnership between Hampton University Architecture and Old Dominion University Engineering & Technology, has had …

Leveraging Transformer-Based Ocr Model With Generative Data Augmentation For Engineering Document Recognition, Wael Khallouli, Mohammad Shahab Uddin, Andres Sousa-Poza, Jiang Li, Samuel Kovacic

Engineering Management & Systems Engineering Faculty Publications

The long-standing practice of document-based engineering has resulted in the accumulation of a large number of engineering documents across various industries. Engineering documents, such as 2D drawings, continue to play a significant role in exchanging information and sharing knowledge across multiple engineering processes. However, these documents are often stored in non-digitized formats, such as paper and portable document format (PDF) files, making automation difficult. As digital engineering transforms processes in many industries, digitizing engineering documents presents a crucial challenge that requires advanced methods. This research addresses the problem of automatically extracting textual content from non-digitized legacy engineering documents. We introduced …

Online Parameter Adaptation Of Lqr Controllers Via Rls For Prosthetic Joint Control: Experimental Validation On A Quanser Qube-Servo 2 Platform, Cynthia Lopez-Jordan

Theses and Dissertations

This thesis develops and experimentally validates an online adaptive Linear Quadratic Regulator (LQR) control method for prosthetic joint systems using Recursive Least Squares (RLS)-based real-time parameter estimation on the Quanser QUBE-Servo 2 platform. Traditional LQR controllers assume a fxed system model, which limits adaptability and results in reduced tracking accuracy, poor robustness, and loss of optimal performance when applied to dynamically changing prosthetic joints, infuenced by load variations, user gait changes, and mechanical wear. Limited experimental validation exists for combining RLS with online LQR adaptation in prosthetic-like systems.

To address these limitations, an RLS-driven Adaptive LQR framework was implemented to …

Design And Control Of A Stroke Therapy Device, Hugh Elliott

Open Access Master's Theses

Stroke is a leading cause of physical disability around the world, and the likelihood of stroke increases as people live longer. The current number of physiotherapists is insufficient to meet the increasing demand for their services. As a result, there has been a focus on developing robotic devices that function similarly to traditional therapy, enabling multiple patients to be seen simultaneously. While many devices have been created and tested, most are expensive, complex, and require trained personnel for supervision, thereby limiting their outreach. This thesis presents the design and control of a low-cost stroke therapy device designed to promote upper …

Lunar Refueling: Legal Issues And Suggested Solutions, Francesca Giannoni-Crystal

Journal of Law and Mobility

The establishment of settlements and economic activities on the Moon is expected to occur in the near future, positioning the Moon as a critical hub for continued exploration of the Solar System. Central to this development is the creation of a lunar refueling industry, which will play a pivotal role in supporting lunar activities and fostering further exploration.

Lunar refueling, which includes extracting local resources like lunar ice water to obtain hydrogen, offers key benefits, such as reducing the need for resupply missions from Earth, lowering launch costs, extending mission capabilities, and enabling launches from the Moon, which are more …

Development Of A Spss-Based Prediction Model To Evaluate ‎Volatile Organic Compounds During Trenchless Cured-In-Place Pipe Method, Salar Bavili Nezhad

Civil Engineering Dissertations - Archive

The Cured-in-Place Pipe (CIPP) method is a widely implemented trenchless technology for the rehabilitation of deteriorated pipelines, offering benefits such as cost-effectiveness and reduced surface disruption. However, the CIPP installation process, particularly during curing, raises concerns over the emission of Volatile Organic Compounds (VOCs), which can adversely impact worker safety, public health, and environmental standards. This dissertation aims to address these concerns by evaluating VOC emissions during CIPP installations and developing a predictive model to guide emission management practices.

A comprehensive field study was conducted, collecting air samples from 15 pipeline rehabilitation sites that utilized different site-specific conditions using non-Styrene …

Enhancing Operational Efficiency Of Paratransit Services Using Predictive Models, Troyee Saha

Civil Engineering Dissertations - Archive

Paratransit services play a vital role in supporting the mobility of older adults and individuals with disabilities, yet they experienced major disruptions during the COVID-19 pandemic and continue to face ongoing operational issues such as trip cancellations. This dissertation explores these challenges through three distinct analyses using data from Arlington, TX. The first chapter investigates how COVID-19-related factors (policies, cases, and vaccination) and socio-demographics influenced paratransit usage from 2019 to 2021. Applying SARIMAX and Poisson regression models, the study finds a substantial drop in ridership—41% in 2020—and a shift toward essential medical travel. It also reveals that restrictive policies, such …

Development Of Supervised Machine Learning-Based Life-Cycle Cost Estimation And Prediction Models For Comparative Sewer System Rehabilitation Using Open-Cut And Trenchless Cured-In-Place Pipe Methods, Gayatri R. Thakre

Civil Engineering Dissertations - Archive

Aging wastewater infrastructure in the United States demands renewal strategies that balance cost-effectiveness, sustainability, and minimal social disruption. Conventional open-cut pipeline installation (OCPI) involves extensive excavation and restoration, whereas trenchless alternatives such as Cured-in-Place Pipe (CIPP) Renewal Technology offer reduced surface disturbance and environmental impacts. However, existing studies primarily focus on Construction Costs (CC), neglecting integrated life-cycle evaluations that also account for Environmental Costs (EC) and Social Costs (SC).

The primary objectives of this research are to develop supervised machine-learning (ML) models to estimate and predict CC in 2025 US dollars (USD) per linear foot of OCPI and CIPP Renewal …

Development Of A Drone-Assisted Pavement Management Framework Based On The Pavement Condition Index For University Parking Lots, Omesh Pasuluru

Civil Engineering Theses - Archive

Efficient pavement management is essential for keeping university parking lots in good condition. At the University of Texas at Arlington, parking areas experience heavy use and environmental wear, which can cause damage if not addressed early. Traditional methods for assessing pavement conditions are time-consuming, interrupt daily activities, and are expensive. Hence, there is a need for better solutions. This study introduces a drone-based pavement management approach that uses the Pavement Condition Index (PCI) system. The PCI is a numerical scale from 0 to 100 that rates pavement quality based on surface condition. A high PCI score (85-100) indicates the pavement …

Structural Performance Of High-Rise Rc Buildings With Sfrc Columns And Shear Walls Subjected To Seismic Loading, Ali Azzawi

Civil Engineering Theses - Archive

To investigate the seismic performance of high-rise RC buildings with steel fiber reinforced concrete (SFRC) columns and shear walls, a detailed numerical analysis was established using RISA-3D software on twelve-story RC buildings subjected to earthquakes. The variables included in this research are steel fiber volume fraction (SFVF), number of stories with SFRC columns and shear walls, and concrete strength grade. The mechanical properties of the concrete for each mix are evaluated experimentally. Three types of concrete mix designs were performed in the Civil Engineering Laboratory Building (CELB) using different dosages of steel fibers (0, 25lb/cy, and 70lb/cy). The properties of …

Characterization Of Municipal Solid Waste Using Machine Learning Based Imaging And Chemical Analysis, Enyonam Ahadzi

Theses and Dissertations--Biosystems and Agricultural Engineering

According to the U.S. Department of Energy’s 2023-billion-ton report, the United States generates nearly 300 million tons of municipal solid waste every year. More than 50% of that waste is underutilized and ends up in landfills. This poses serious public health and environmental risks. But beyond the environmental and health implications, this is also a wasted opportunity. The U.S. Energy Information Administration estimates that, for every 100 lbs of waste we throw away, about 85% can be used as fuel or for electricity generation. However, its complex and heterogeneous nature poses challenges for efficient sorting and valorization in waste to …

Valorizing Municipal Solid Waste For Sustainable Aviation Fuel And Polyhydroxyalkanoate Bioplastics: Pyrolysis And Microbial Pathways, Emon Das

Theses and Dissertations--Biosystems and Agricultural Engineering

The escalating global burden of municipal solid waste (MSW), projected to reach 3.88 billion tons annually by 2050, calls for innovative valorization strategies to mitigate environmental impacts and promote a circular bioeconomy. This thesis investigates the conversion of MSW into two high-value products: sustainable aviation fuel (SAF) and polyhydroxyalkanoate (PHA) bioplastics. Chapter one presents comprehensive physicochemical characterization and pyrolysis-GC/MS analysis of MSW feedstocks. The physicochemical results reveal that densification enhances handling and storage properties, while pyrolysis-GC/MS analysis indicates that plastic-rich MSW streams produce bio-oils with favorable hydrocarbon profiles suitable for SAF production, potentially contributing to decarbonization efforts in the aviation …

A Design And Analysis Of Computer Experiments Approach To Water Distribution Network Seismic Rehabilitation Optimization, Uthman Abiola Kareem

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Water is an essential part of human life. However, there are critical infrastructures that enable water availability in communities and homes. One of such is a water distribution network. Water distribution network performance depends on its reliability, which could be threatened by external agents like earthquakes. When earthquakes occur, they cause damages on some pipes within the distribution network and this limits performance of water distribution network. While earthquakes cannot be prevented, effective maintenance intervention may reduce the impact of earthquakes on water distribution networks. In order to develop an effective maintenance plan, researchers approach it in different ways. However, …

Analysis Of Crowd Logistics Networks Using Agent-Based Models, Preetam Kulkarni

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Crowd logistics is a system in which an online platform connects a group of non-professional couriers (crowd/carriers), who use their under-utilized resources to offer delivery service to other individuals or businesses (senders) for a fee. While crowd logistics platforms have the potential to offer more flexible and responsive delivery services for much lower rates than traditional logistics providers, it is difficult for platforms to be successful as it is challenging to meet carriers’ and senders’ expectations. Crowd logistics has been applied in the context of food and grocery delivery, parcel pickup and drop-off services and last-mile delivery, however, it has …