Digital Commons Network^™

Additive Manufacturing Of Carbons From Commodity Polyolefins, Paul Smith

Dissertations

Though tremendous progress has been made engineering carbon materials across length-scales from the molecular to the macroscopic, on-demand macro-structural control of carbons is still developing. Many carbon materials like graphene, carbon nanotubes, activated carbons, and carbon fibers have powder or fiber form factors. Recent research has pioneered on-demand carbon production through additive manufacturing (AM) via 1) extrusion and post-processing of highly filled carbon slurries, or 2) printing and pyrolysis of polymeric carbon precursors such as polyimides, acrylated polyethylene glycol, and phenolics. While groundbreaking, most methods face challenges with adoption due to costly/complex materials and manufacturing processes, and large dimensional changes …

A Review Of Waste Heat Sources For District Heating, Olamide Opadokun, Yong Tao, Julian Lamb

Mechanical Engineering Faculty Publications

As the world's energy needs rise, carbon emissions and climate change become a bigger concern. Therefore, there is a growing need for cleaner energy sources as well as higher levels of energy efficiency. Building energy is of great interest to researchers and policymakers, as it accounts for about a third of global energy consumption, and this is projected to rise as more people gain access to higher incomes and improved amenities. For over a century, district energy systems have proved to be an efficient means of providing thermal energy to buildings, and developments in district heating have enabled the use …

Measurement-Based Dynamic Load Model Parameterization Via A Stacked Long Short-Term Memory - Deep Neural Network, Zach H. Smith

All Theses

Increases in distributed generation and changes to predominate load types in modern power systems are driving the need for updated or newly developed dynamic load models. Accurate load modeling is necessary for transmission planning and operation, post-mortem analysis, and inter-regional transfer studies. The most widely used dynamic load model is the WECC Composite Load (CMLD). The CMLD model is an aggregation of substation impedance, under voltage and frequency controls, dynamic motor loads, and static loads. Parameterizing dynamic load models, especially composite models with high parameter counts like the CMLD, is can be difficult. This work proposes a measurement-based, machine learning …

Extremum-Seeking Approach For Real-Time Self-Healing Of Position Sensor Offset Error In Non-Salient Pmsms, Ramitha Kalhara Dissanayake Ralalage

Masters Theses

The inherent advantages of permanent magnet synchronous machines (PMSMs), such as high efficiency, has led to their frequent use in industry, including safety-critical applications, such as transportation electrification. The accurate measurement of the rotor position is key to achieving efficient and reliable field-orientation-based torque regulation. With the high reliance on the rotor position measurement, position sensor fault diagnosis and mitigation facilitate a layer of safety. Conventional methods for compensating position sensor offset errors in electric drives typically depend on accurate knowledge of motor parameters. However, these parameters are often subject to variation due to temperature changes, system aging, and other …

Depth-Averaged Two-Dimensional Hydrodynamic Modeling In Headwater Channel And Floodplain Design., Jesse Dylan Robinson

Electronic Theses and Dissertations

In the channels and floodplains of inland waterways the hydrodynamic forces of floods destroy property and infrastructure, threaten lives, and damage aquatic habitat. Flood simulations using robust and efficient depth-averaged two-dimensional hydrodynamic models (2D models) can be interpreted to design effective solutions for areas vulnerable to damage. The reliable interpretation of 2D models for use in design is improved here through direct comparison of 2D model output to observed flood events at 6 headwater research sites. Instrumentation was used for model calibration and to define the surface hydrodynamics at sites with confined flows, wide and shallow flows, at vertical steps, …

Molecular Dynamics Simulations Of Biologically Relevant Interfaces: From Tear Film Lipid Layers To Rna Adsorption On Silica Surfaces., Mahbuba Khanom

Electronic Theses and Dissertations

Molecular dynamics (MD) simulation is an important tool in biochemical sciences for studying complex molecular processes and interfacial interactions at the molecular level. Biological interfaces play key roles in processes such as ocular lubrication and biomolecular adsorption. This dissertation studies interfacial phenomena involving two distinct yet conceptually related systems: the tear film lipid layer (TFLL) at the air–water interface at the surface of the human eye, and RNA adsorption on silica surfaces. These studies provide insight into how interfacial composition, structure, and environmental conditions affect larger-scale behavior. Atomistic MD simulations were used to model the TFLL. The TFLL is essential …

Integrating Due Process Into Large Language Models., Joshua Paul Johnson

Electronic Theses and Dissertations

This research investigates the ability of large language models (LLMs) to recognize due process issues. Due process is a legal concept focused on the protection of the individual during interactions with government when life, liberty, or property are being impacted. Due process presents both substantive and procedural aspects that are challenging to incorporate into generative artificial intelligence. Through assessing model performance, creating benchmarking techniques, retrieval-augmented generation (RAG), and fine-tuning, this work seeks to measure due process recognition performance and improve performance in identifying due process issues. The results of evaluating larger parameter LLMs such as from Google, Meta, and OpenAI …

Thermal Heterogeneity And Lithium Plating During Fast Charging Of Lithium-Ion Battery., Ayodeji Avis Adeniran

Electronic Theses and Dissertations

Presently, widespread adoption of electric vehicles (EVs) is hindered by challenges associated with XFC, including heat generation, lithium plating, and accelerated battery degradation. This dissertation addresses these barriers through two coordinated themes—lithium plating and thermal management—spanning four manuscripts that integrate operando diagnostics, physics-based simulation, and module-level design optimization. The first theme seeks a fundamental investigation into the dynamic interplay between temperature heterogeneity and lithium plating during fast charging, a phenomenon that poses significant limitations on the performance of graphite-based anodes. Firstly, a custom operando cell with a sapphire window was designed to enable synchronized MWIR thermography and optical imaging of …

Alkali-Silica Reactivity And Ionic Transport In Mortar With Hydrophobic Inclusions., Isaac Offei

Electronic Theses and Dissertations

Alkali-silica reaction (ASR) causes extensive damage to concrete infrastructure worldwide, with traditional mitigation strategies increasingly constrained by supplementary cementitious material (SCM) supply limitations. This dissertation investigates an innovative approach to ASR prevention through strategic application of hydrophobic materials to modify moisture and ionic transport pathways in cement mortars. The research employed a comprehensive three-objective experimental program using highly reactive aggregates and three hydrophobic materials: hexamethyldisilazane (HMDS)-treated fumed silica, silane-based emulsion, and silane-based crème. The first objective demonstrated the feasibility of hydrophobic aggregate surface modification, achieving 46% and 38% reductions in ASR expansion for washed and non-washed hydrophobic aggregates, respectively. Microstructural …

Detecting Non-Axisymmetric Instabilities In Fluid-Based Manufacturing Via Multi-View Tensor Analysis., Bidusi Khadka

Electronic Theses and Dissertations

Fluid-based manufacturing processes, such as inkjet printing and electrospinning, fabricate micro- and nano-scale structures with high precision, but are prone to complex fluid dynamics exhibiting axisymmetric and non-axisymmetric instabilities. Conventional monitoring often relies on single-camera inputs and symmetry assumptions, limiting the detection of three-dimensional anomalies like jet deflection. This study presents a novel multi-view streaming video-based anomaly detection framework to address this gap. The framework employs a modified Tensor Sequential Sampling (TSS) algorithm with edge-based sampling to capture geometric spatiotemporal features of each camera view using the videos obtained from an orthogonally positioned dual-camera setup. These features are fused with …

Isolated Dc-Dc Converter For An Ev Microgrid, Oscar Yu, William Leiker

Electrical Engineering

This product is a redesign of a DC-DC buck-boost converter which utilizes a new topology, the flyback converter, for use in an electric vehicle (EV) as a microgrid. The main driver behind the redesign is to provide electrical isolation between elements in the microgrid. The EV microgrid consists of the battery, motor, external DC and AC ports, and the power electronics (DC-DC converter and AC-DC inverter) which were designed and built in previous senior projects. Using EV’s as microgrids can help relieve stress from the main power grid caused by charging electric vehicles. Implementing EV’s as a microgrid enables the …

Effect Of Polymer Contaminants Sourced From Coated Paper On The Performance Of The Resulting Recycled Paper, Ezekiel J. Guevarra

All Theses

The growing demand for sustainable packaging has accelerated the use of paper-based materials as alternatives to plastics. To provide barrier and functional properties, these materials are often modified with polymer coatings. While beneficial during use, such coatings can persist as contaminants during recycling, potentially disrupting fiber bonding and reducing the quality of recycled paper. This study examined the impact of extrusion-coated low-density polyethylene (LDPE) films and two aqueous dispersions (Vapor/Water-Barrier, Acrylic Film (VWAF) and Oil & Grease Barrier (OGBF)) on contaminant distribution and mechanical performance of recycled handsheets. Kraft paper coated at varying levels was repulped and formed into handsheets, …

Ai-Optimized Resource Management In Next-Gen Wireless Networks, Fatemeh Lotfi

All Dissertations

Next-generation wireless networks must deliver highly adaptive, scalable, and intelligent connectivity to satisfy the heterogeneous demands of emerging services, including enhanced mobile broadband, massive machine-type communications, and ultra reliable low latency applications. The Open Radio Access Network (O-RAN) paradigm has emerged as a key enabler of this vision, introducing openness, virtualization, and artificial intelligence (AI)-driven control into the RAN ecosystem. O-RAN’s disaggregated architecture facilitates multi-vendor interoperability and empowers intelligent management through the RAN Intelligent Controller (RIC). However, achieving real-time, autonomous, and generalized optimization in such a dynamic environment remains a significant challenge due to its distributed nature, non-stationary traffic, and …

Adaptive Deep Learning In Physical Layer Applications, Ali Owfi

All Dissertations

Traditionally, signal processing models in communication systems have been designed based on solid foundations in statistics and information theory, often assuming linearity and optimizing for simplified models. However, real-world communication systems exhibit numerous imperfections and non-linearities that traditional linear models struggle to capture accurately. Deep Learning (DL)-based approaches, unconstrained by rigid mathematical models, have shown promise in optimizing system performance by accommodating specific hardware configurations and dynamic channel conditions as an alternative to the traditional methods. Despite all the recent research efforts on DL-based methods for physical layer applications, DL models have still not been widely applied to physical layer …

Friction And Texture Evaluation Of Asphalt-Based Binders As Alternatives To Epoxy-Based High-Friction Surface Treatments, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-friction surface treatment (HFST) is a safety-focused pavement treatment that restores and maintains pavement friction to reduce road accidents. Traditional epoxy-based HFSTs, while widely used, face challenges such as high costs, potential compatibility issues with the substrate pavement, and long-term durability under specific conditions. This study investigates asphalt-based alternative HFST, which is compatible with various pavement types and cost-effective and versatile solutions for a wider range of pavement applications. Performance and friction testing, including the British pendulum test, British wheel test, and dynamic friction test, were performed to examine the coefficient of friction (COF) before and after polishing with a …

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Lifestyle Habits On Arterial Compliance, Joshua M. Whitaker

Master's Theses

Cardiovascular disease remains as a leading cause of death for both sexes and across all racial backgrounds. Continuing to research causes, early predictors, and preventative actions are paramount to ensuring that cardiovascular disease starts to decrease in its activity. Endothelial dysfunction is the earliest known predictor of cardiovascular disease, therefore investigating early detection methods of endothelial dysfunction can improve health outcomes. This study revolves around a non-invasive calibrated cuff device that uses the principles of segmental plethysmography and oscilliometry to measure arterial compliance of baseline and induced hyperemic conditions in human subjects to determine how well arteries vasodilate in response …

Draft Genome Sequences Of Four Phosphate-Solubilizing Microbes Of The Family Burkholderiaceae Isolated From Tailings From The Former Pea Ridge Mine In Washington County, Mo, Usa, Prince Oppong Amoh, Abiodun E. Idowu, Elizabeth R. Grube, Melanie R. Mormile, Hunter W. Schroer

Biological Sciences Faculty Research & Creative Works

We present draft genome sequences of four Gram-negative phosphate-solubilizing microbes isolated from Pea Ridge Mine tailings in Missouri, USA. Belonging to the family Burkholderiaceae, these isolates exhibit a phosphate-mineral-dissolving phenotype in liquid and solid cultures. Genome sizes span 5.6–9.7 Mb, with GC contents of 61.6%–67.0%.

Mechanics Post-Tavr For Trileaflet Vs Bicuspid Aortic Valves: Insights From Computational Simulation, Breandan B. Yeats, Aniket Venkatesh, Sri Krishna Sivakumar, Hoda Hatoum, Milad Samaee, Venkateshwar Polsani, Et. Al.

Michigan Tech Publications

Background: Bicuspid aortic valve (BAV) disease is the most common congenital heart defect and is associated with elliptical openings and excess calcification. Limited data are available on long-term efficacy of transcatheter aortic valve replacement (TAVR) for BAV patients.

Objectives: The purpose of this study was to compare simulated mechanical metrics post-TAVR between BAV and trileaflet patients with calcific aortic stenosis.

Methods: Pre-TAVR computed tomography scans of trileaflet (n = 22) and BAV (n = 25) were used to segment the aortic valve. Simulated balloon-expandable stent deployment was performed from a previously developed protocol. The bioprosthetic leaflets were then pressurized under …

Evaluating The Preparedness Of Local Zoning Regulations For Flood Risk Reduction In The Most Affected Local Jurisdictions In Nebraska, Md Asaduzzaman Noor

Community and Regional Planning Program: Theses

Flooding has profound social, economic, and environmental impacts on local communities, and zoning plays a critical role in mitigating these risks. The 2019 Nebraska floods, among the most severe in the state’s history, highlighted the urgent need to strengthen local preparedness and mitigation strategies. This study assesses the extent to which local zoning regulations in Nebraska’s most affected jurisdiction, including rural areas, address flood risk reduction. A systematic review of 117 zoning ordinances from counties, cities, towns, and villages, we applied a structured analytical framework encompassing regulatory and permitting policies, voluntary and incentive-based measures, and nature-based solutions. The results show …

Platforming For Circuit Education, Grady Oliver Schneider

Computer Engineering

The purpose of this project was to provide an alternative for students being introduced to resistive circuits. As a freshman in electrical engineering (transferred to computer engineering), I saw the struggles of other freshman to grasp the conceptual basics of circuits. While there’s lots of guides to circuit education, I think many of them fall short of being both engaging and teaching the intuition behind circuits. A lot of the more advanced concepts in circuits depends on the basic intuition of KCL, KVL, and Ohm’s Law. While there’s several basic techniques (such as voltage divider, current divider, and mesh current …

Capillary Imbibition Of Shear-Thinning Xanthan Gum Solutions, Aimee Sayster

All Theses

Capillary rise in confined geometries plays a critical role in numerous natural and industrial processes. While classical models such as the Lucas–Washburn equation accurately describe the dynamics of Newtonian fluids, they fail to capture the complex behavior of shear-thinning, non- Newtonian fluids whose viscosity varies with shear rate. This research investigates the capillary rise dynamics of shear-thinning xanthan gum polymer solutions in capillary tubes. The rheological behavior of each fluid is characterized using the Ellis model, which accounts for shear-thinning effects through three key parameters: zero-shear viscosity μ0, characteristic shear stress τ1/2 and viscosity index α. Experimental data was collected …

Dendrimer Gel Nanoparticles With Dual-Targeting Of Upar And Ribonucleotide Reductase R2 Influence Necrosis, Apoptosis, And Cell Cycle Arrest In Triple-Negative Breast Cancer, Hsin Yin Chuang, Yue-Wern Huang, Hu Yang

Biological Sciences Faculty Research & Creative Works

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited treatment options due to the absence of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER2) receptors. We previously developed highly adaptable polyamidoamine (PAMAM) dendrimer-based gel nanoparticles (GDP-uPA/GTI) with dual-targeting capabilities against urokinase-type plasminogen activator receptor (uPAR) and ribonucleotide reductase R2 (R2) to achieve selective antitumor effects. In this study, we investigated the underlying mechanisms of GDP-uPA/GTI-induced tumor inhibition. In vivo, GDP-uPA/GTI significantly downregulated R2 expression and activated caspase 8 and caspase 3, indicating caspase-dependent apoptosis. Histological evaluation of major organs revealed no observable toxicity. …

Elucidating Differences In Constitutionally Isomeric Diamine- And Bisphenol-Based Polybenzoxazine Networks, Benjamin L. G. Morasch

Dissertations

This dissertation aims to expand the fundamental understanding of diamine-based benzoxazine chemistry by examining how synthesis influences the network properties of 4,4’-ddm and phenol-based (P-ddm) benzoxazine, compared to the constitutionally isomeric bisphenol-F and aniline-based (BF-a) benzoxazine. While bisphenol-based benzoxazines such as BF-a have been studied more extensively, diamine-based benzoxazines are still relatively unexplored due to the competition with the formation of 1,3,5-hexahydrotriazine intermediates and the inconsistent thermal and mechanical properties reported in the literature. These inconsistencies stem from factors including synthetic methods, curing conditions, and degradation during polymerization that have been overlooked.

To address these issues, this dissertation is organized …

Upcycling Commodity Polymers To Advanced Materials For Energy And Environmental Sustainability, Anthony Griffin-Espinoza

Dissertations

Synthetic polymers play an essential role in nearly every aspect of our lives. Extending beyond single-use packaging, polymeric material design has progressed to attain tailorable architectures granting exceptional performance across advanced applications, including carbon-fiber reinforced polymer composites for aerospace, conductive materials for soft electronics, and drug carriers for biomedicine. While highly promising, intricately designed polymers needed to achieve excellent performance often have limited processability, complex synthetic methods, and expensive precursors. Furthermore, due to a lack of recyclability, commodity polymer waste streams result in both environmental impacts and a substantial loss of economic value. This dissertation focuses on developing robust strategies …

Privacy Preserving-Based Artificial Intelligence For Precision Agriculture, Partha P. Sengupta

Dissertations

The research work finds a solution to precision agriculture of cotton cultivation using artificial intelligence (AI) models. Two sets of model performance based on the application are selected namely a low resource and a high resource setting. This is because using drone surveys to capture images identifying the classes of stressed and unstressed cotton plantation requires limited model architecture and CPU based computation. Thus, traditional AI models were selected for low resource settings. Again, for high computation intensive models like transfer learning-convolution neural network (CNN) based architectures were grouped into high resource settings. There was another issue of class imbalance …

Understanding Crystallization Behaviors Of Polyethylene-Derived Vitrimers, Sara Valdez

Dissertations

Polyolefins (POs), particularly polyethylene (PE) and polypropylene (PP), are among the most widely utilized polymers globally, valued for their low production costs and favorable mechanical properties stemming from their semicrystalline microstructure. However, their extensive use and improper disposal have raised serious environmental and human health concerns. In response, PO-derived covalent adaptable networks (CANs) have emerged, integrating dynamic chemistries to enable recyclability and sustainable end-of-life strategies. While existing literature has largely focused on novel CAN systems, structure–property relationships, and network rearrangement in relation to thermal transitions (e.g., topological freezing temperature), the influence of network formation on crystallinity and crystallization kinetics remains …

Processing-Driven Crystallization, Morphology, And Mechanics In Pekk Composites, Nicholas Ryan Enos

Dissertations

This dissertation aims to understand how thermoplastic composites can be processed at faster manufacturing rates while identifying how processing variables influence crystallization, morphology, and mechanical properties. Throughout this dissertation, the influence of nano-scale additives, carbon fibers, rapid cooling, shear, and molecular weight on polymer physics, crystallization, morphology, and mechanics is investigated.

The inclusion of carbon nanotubes and graphene nanoplatelets accelerated crystallization, increased nucleation density, reduced lamellar thickness, and shifted governing Hoffman-Lauritzen growth regimes in PEKK. Velisaris-Seferis modelling identified a surface-induced nucleation mechanism in PEKK nanocomposites, and fast scanning calorimetry allowed for the study of rapid cooling rates, helping to identify …

Steel-Concrete Composite Girder Experiments To Isolate Interface Load Transfer Effects On Stud Fatigue Life, Marc Crespi Hromcova

Graduate Theses and Dissertations

Metal fatigue resulting from repeated loading is a primary limit state that affects the quantity of headed shear studs required in the composite design of steel bridge girders. While concrete-deck-to-steel-superstructure load transfer is only considered through stud bearing in the American Association of State Highway Transportation Officials (AASHTO) design standards, friction and interface interlocking effects may also contribute. This study aims to experimentally quantify the effect of interface conditions on the fatigue life of headed studs within composite girders. In this study, two full-scale composite girder specimens having the same geometry and material properties are tested with two interface conditions. …

Optimizing Indigenous Timber Short-Gap Crossing Designs By Minimizing Wood Moisture Content, Robert Greenwood

Graduate Theses and Dissertations

Reducing moisture content increases wood strength and reduces the weight of timber members. An accurate and efficient method for measuring moisture content is important for the design and construction of indigenous timber short-gap crossings. This study evaluates different methods for measuring moisture content in timber, describes a methodology for developing a representative moisture content value for a timber log, and approaches for quickly drying large timber logs. The results of this thesis will support activities in developing a representative moisture content of a log for structural design purposes and reducing weight for constructability purposes. The approaches discussed were developed considering …

Toward A Better Understanding Of Friction, Adhesion, And Stud Bearing Shear Transfer At The Steel-Concrete Interface Of Composite Bridge Girders, Callie Grace James

Graduate Theses and Dissertations

Following curing of the concrete deck, load transfer between the concrete and steel components in a composite bridge girder is possible through three mechanisms: 1) mechanical contact (bearing) between the embedded shear connectors and surrounding cured concrete, 2) adhesion between the cured concrete and steel-section top flange, and 3) friction between the contacting materials Understanding the mechanisms of bearing, adhesion, and friction shear transfer at the steel-concrete interface of composite bridge girders is necessary for efficient proportioning of headed shear connectors (or studs) in design. To better understand the roles that stud bearing, adhesion, and friction play in composite girder …