Engineering Commons^™

Rational Synthesis Of Ultra-Small And Durable Platinum-Based Catalysts For Renewable Energy Applications, Fahim Bin Abdur Rahman

Theses and Dissertations

Ultrasmall supported platinum nanoparticles (Pt NPs) are often used in two promising renewable energy production technologies – hybrid-sulfur water splitting for actively catalyzing H2SO4 decomposition and in fuel cells for the oxygen reduction reaction (ORR). However, the stability of Pt NPs under reaction conditions is the ultimate challenge for these processes. Two prevalent ways to overcome this challenge are improving stability by anchoring Pt onto a secondary metal or doping heteroatoms into the support. This dissertation covers the rational design, synthesis, and stabilization of Pt-based catalysts in these two ways to achieve durable catalytic performance with desired activity and selectivity. …

Upper Regime Bedform Geometries And Types As A Function Of Sediment Supply And Grain Size, Sydney Sanders

Theses and Dissertations

Most research on fluvial bedforms focuses on the study of dunes (lower regime), and much less is known on upper regime bedforms. Studying upper regime bedforms, the conditions in which they form and how the geometry changes with flow and sediment properties is necessary for interpreting the stratigraphic record, estimate flow resistance and reconstruct flow characteristics from observed geometries. Here I present results of laboratory experiments designed to investigate the role of suspended bed material and sediment grain size on upper regime bedforms. Experiments were performed in open channel flow mode in a sediment-feed flume with a 0.19 m wide, …

Engineering And Optimization Of An Aav Based Viral Vector To Limit The In-Vitro Expression Of Sars-Cov-2 Spike-Protein, Ronald Anderson Smithwick

Theses and Dissertations

Severe Acute Respiratory Syndrome Corona Virus-2, also known as SARS-CoV-2, is a newly emerged respiratory viral pathogen. The outbreak of SARS-CoV-2 started in Wuhan, China, in late 2019 and rapidly transformed into a pandemic. Several vaccines have been developed and are available to the public on an unprecedented timeline, protecting individuals from a severe infection and saving precious lives. However, none of the vaccines can provide a sterile immunity, and the SARS-CoV-2 transmission cycle continues. Additionally, because of the mutation-prone RNA genome and immunological selection pressure, SARS-CoV-2 is rapidly mutating, especially the Spike(S) protein, and new viral strains are arising …

First-Principles Based Heterogeneous Catalyst Design For Energy Conversion And Plastics Upcycling Processes, Kyung-Eun You

Theses and Dissertations

Replacing scarce and expensive Pt-group metals (Pt, Pd, Ir, Rh, and Ru) commonly used in heterogeneous catalysis with earth-abundant and inexpensive materials is an important challenge to achieve sustainability

The main focus of the first project is to develop highly selective non-precious metal catalysts for the hydrodeoxygenation (HDO) of biomass-derived polyols and we chose to examine the HDO of glycerol and its deoxygenated reaction products (1,2- and 1,3- propanediol) over Cu modified Mo₂C (Cu/Mo₂C) catalysts. In this study, we combined experimental and density functional theory (DFT) results to reveal that the Cu modifier can significantly reduce …

Manufacturing Process Considerations When Transitioning From Thermoset To Thermoplastic Composite Material For Urban Air Mobility Propellers, Samuel Leonard Jones Iii

Theses and Dissertations

Aerospace manufacturing has seen continually increased use of carbon fiber reinforced polymers in aircraft structures. The favorable strength to weight ratios, as well as the increased resistance to fatigue and corrosion, compared to metallic structures, provide a common argument for further research and development of composite airframes. Two main classes of carbon fiber reinforced polymers can be distinguished, thermosetting polymers and thermoplastic polymers. Thermoset polymers have been relied on for decades for the ability to reliably produce strong laminates for aircraft structures. By comparison thermoplastic polymers experience less comparable utilization on primary structures despite boasting similar or greater performance capabilities …

Fundamentals Of Adsorption And Large Scale Pressure Swing Adsorption (Psa) Process Design, Huan Jiang

Theses and Dissertations

This work focused on both fundamental of adsorption and large-scale PSA design. Chapter 1 and 2 addressed the analysis of conditions for formation of adsorption azeotropes in binary systems. Chapter 1 theoretically assessed the necessary and sufficient conditions for the formation of an adsorption azeotrope in a binary gas mixture when this mixture exhibits either intersecting or non-intersecting single gas isotherms. Chapter 2 confirmed theoretically whether adsorption azeotropes can form in a binary mixture at a pressure below the intersection pressure of the corresponding single gas isotherms. Analytical expressions derived for both general and dual thermodynamically consistent process Langmuir (DPL) …

Classification Of Acoustic Emission Data Into Load Steps Using An Artificial Neural Network, Allen Ross

Theses and Dissertations

The average age of bridges in South Carolina is approaching 40 years, very close to the 50-year service life. Almost 11% of the bridges in South Carolina are rated as structurally deficient, greater than the national average of 7.5% (South 2021). Health monitoring is the concept that in-situ sensors can continuously monitor civil structures and send real time signals of damage. This process allows for automation and could save time and money on the inspection and load rating of bridges. Health monitoring requires sensors that provide uninterrupted data without sacrificing the functionality of the bridge. A prime candidate for this …

Interrogating The Role Of Ing4 In Hematopoietic Stem Cells And Cancer, Zanshé Thompson

Theses and Dissertations

We recently identified the tumor suppressor, Ing4, as a critical regulator of hematopoietic stem cell (HSC) homeostasis. The mis-regulation of Ing4 in human cancers has also been shown to lend malignant cells specific advantages that support carcinogenesis and tumor progression. This activity is, in part, due to Ing4 mediated regulation of overlapping signaling pathways that regulate stem cell activity and cancer cells, including NF-B and c-Myc. In a two-part study, we have investigated the role of Ing4 in murine hematopoiesis and human malignancies. While the specific mechanisms of stem cell self-renewal, maintenance, and differentiation are poorly characterized, we have determined …

Quadratic Neural Network Architecture As Evaluated Relative To Conventional Neural Network Architecture, Reid Taylor

Senior Theses

Current work in the field of deep learning and neural networks revolves around several variations of the same mathematical model for associative learning. These variations, while significant and exceptionally applicable in the real world, fail to push the limits of modern computational prowess. This research does just that: by leveraging high order tensors in place of 2nd order tensors, quadratic neural networks can be developed and can allow for substantially more complex machine learning models which allow for self-interactions of collected and analyzed data. This research shows the theorization and development of mathematical model necessary for such an idea to …

In Vitro And In Vivo Studies Of Mediator Kinase, Lili Wang

Theses and Dissertations

This project addresses the molecular and in vivo activities of transcriptionregulating module CKM, comprised of CDK8 (or CDK19) kinases, Cyclin C, MED12 and MED13. Our lab has found that CDK8/19 potentiates NFkB-induced transcription. In this study, we confirmed that both CDK8 and CDK19 regulate gene expression in kinasedependent manner. CDK8 and CDK19 are not required for NFkB-induced transcription, which also occurs in HEK293-dKO (CDK8 and CDK19 double knockout) cells, but such transcription becomes CDK8/19-dependent upon re-expression of CDK8 or CDK19 in dKO. Surprisingly. pre-treatment with a CDK8/19 inhibitor decreases the effect of CDK8/19 on NFkB-induced transcription.

In another set of …

Mechanistic Multiphysics Modeling Of Cladding Rupture In Nuclear Fuel Rods During Loss-Of-Coolant Accident Conditions, Kyle Allan Lawrence Gamble

Theses and Dissertations

The Loss of Coolant Accident (LOCA) is a design basis accident that is included as part of the safety analysis of nuclear power plants. As the nuclear industry desires to increase the cycle length and discharge burnup of existing nuclear power plants they must demonstrate safe operation during a LOCA on high burnup fuel. During a LOCA transient on high burnup fuel rods, the rods may undergo a process known as fuel fragmentation, relocation, and dispersal (FFRD). To permit dispersal, the cladding encapsulating the fuel must rupture with an opening size large enough to allow the fragmented fuel particles to …

The Submission Of A Section 513(G) Request For Information, Morgan Ashley Lano

Theses and Dissertations

The Food and Drug Administration designates all medical devices into one of three general classes contingent on their intended use, indications for use, and potential risk to the user. This classification dictates the further path the device must take to be approved for the commercial market. Section 513(g) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 360c(g)) is submitted in order to gain the agency’s unofficial classification and suggested regulatory requirements. The Coagulation Companion (MicroVide) is a device designed to fluorescently quantify a key enzyme involved in the coagulation cascade, plasmin, in pediatric patients. clot formation and degradation …

Coalitional Game Theory For Stormwater Management And Green Infrastructure Practices, Carly Lawyer

Theses and Dissertations

As global warming and climate Variability bring about more frequent and intense rainstorms and accelerate sea level rise, our social and built environments are at heightened risk of flood induced damages and consequent costs. This is particularly true for coastal areas, facing the coupled effects of these threats while serving as home to people, businesses, unique landscapes, and historic landmarks. Complex decisions at all levels of government and community planning stand to benefit from increased understanding of possible outcomes and pathways resulting from decentralized human behavior and decision making in the realm of water resources engineering and management. Game theory …

Deep Learning Based Generative Materials Design, Yong Zhao

Theses and Dissertations

Discovery of novel functional materials is playing an increasingly important role in many key industries such as lithium batteries for electric vehicles and cell phones. However experimental tinkering of existing materials or Density Functional Theory (DFT) based screening of known crystal structures, two of the major current materials design approaches, are both severely constrained by the limited scale (around 250,000 in ICSD database) and diversity of existing materials and the lack of a sufficient number of materials with annotated properties. How to generate a large number of physically feasible, stable, and synthesizable crystal materials and build accurate property prediction models …

Understanding The Mechanism Of Deep Learning Frameworks In Lesion Detection For Pathological Images With Breast Cancer, Wei-Wen Hsu, Chung-Hao Chen, Chang Hao, Yu-Ling Hou, Xiang Gao, Yun Shao, Xueli Zhang, Jingjing Wang, Tao He, Yanhong Tai

Electrical & Computer Engineering Faculty Publications

With the advances of scanning sensors and deep learning algorithms, computational pathology has drawn much attention in recent years and started to play an important role in the clinical workflow. Computer-aided detection (CADe) systems have been developed to assist pathologists in slide assessment, increasing diagnosis efficiency and reducing misdetections. In this study, we conducted four experiments to demonstrate that the features learned by deep learning models are interpretable from a pathological perspective. In addition, classifiers such as the support vector machine (SVM) and random forests (RF) were used in experiments to replace the fully connected layers and decompose the end-to-end …

Biomechanical Analysis Of Athletes Sprinting With Varying Degrees Of Resistance, Michaela Ott

Honors Program: Senior Projects (Public)

Utilizing resistance methods for sprinters is a common approach to their training. In this study, six athletes from the University of Nebraska-Lincoln Women’s Track and Field Team ran a series of sprints using a resistance machine to collect data regarding the change in power output, stride length, level of trunk tilt with respect to the ground, and acceleration throughout a distance of ten meters when different amounts of resistant forces were applied to the athlete. It was hypothesized that as resistance increased, power output would increase, stride length would decrease, the runners would become more horizontal resulting in a larger …

Stochastic Model Predictive Control Via Fixed Structure Policies, Elias Wilson

Doctoral Dissertations and Master's Theses

In this work, the model predictive control problem is extended to include not only open-loop control sequences but also state-feedback control laws by directly optimizing parameters of a control policy. Additionally, continuous cost functions are developed to allow training of the control policy in making discrete decisions, which is typically done with model-free learning algorithms. This general control policy encompasses a wide class of functions and allows the optimization to occur both online and offline while adding robustness to unmodelled dynamics and outside disturbances. General formulations regarding nonlinear discrete-time dynamics and abstract cost functions are formed for both deterministic and …

Influence Of Cavs On Driver’S Decisions In Various Roadway Scenarios, Nathalie Joy Taboga Dante

Honors Capstones

No abstract provided.

Polyaniline/Cobalt Nanoparticle Composite Films, Rifat Mahbub

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Polymer nanocomposites have been gaining attention because of the enhanced properties of the element materials it can offer. These composites have been used in biological sector as well as quantum computing and memory devices. These are also used as different kind of sensors. Polymer composites incorporated with magnetic nanoparticles can modify the magnetic property of the nanoparticles and that has huge potential to be used in different sort of applications.

This work aims to develop a polymeric nanocomposite incorporating a conducting polymer and magnetic nanoparticles. The influence of the conducting polymer on the magnetic property of the nanoparticles was investigated. …

Application Of Red Cabbage Anthocyanins As Ph-Sensitive Pigments In Smart Food Packaging And Sensors, Reza Abedi-Firoozjah, Shima Yousefi, Mahshid Heydari, Faezeh Seyedfatehi, Shima Jafarzadeh, Reza Mohammadi, Milad Rouhi, Farhad Garavand

Research outputs 2022 to 2026

Anthocyanins are excellent antioxidant/antimicrobial agents as well as pH-sensitive indicators that provide new prospects to foster innovative smart packaging systems due to their ability to improve food shelf life and detect physicochemical and biological changes in packaged food. Compared with anthocyanins from other natural sources, red cabbage anthocyanins (RCAs) are of great interest in food packaging because they represent an acceptable color spectrum over a broad range of pH values. The current review addressed the recent advances in the application of RCAs in smart bio-based food packaging systems and sensors. This review was prepared based on the scientific reports found …

Multiscale And Multiphysics Influences On Fluids In Unconventional Reservoirs: Modeling And Simulation, Jianchao Cai, David A. Wood, Hadi Hajibeygi, Stefan Iglauer

Research outputs 2022 to 2026

Unconventional reservoir resources are important to supplement energy consumption and maintain the balance of supply and demand in the oil and gas market. However, due to the complex geological conditions, it is a significant challenge to develop unconventional reservoirs efficiently and economically. At present, unconventional reservoirs are extensively studied, covering a wide range of areas, with special attention to the multiscale characterization of pore structures and fracture networks, description of complex fluid transport mechanisms, mathematical modeling of flow properties, and coupled analysis with multiphysics fields. This work briefly describes the multiscale and multiphysics influences on fluids in unconventional reservoirs, and …

Conditional Variational Autoencoder (Cvae) For The Augmentation Of Ecl Biosensor Data, Matthew Dulcich

Honors Theses

Machine Learning (ML) is vastly improving the world, from computer vision to fully self-driving cars, we are now able accomplish objectives that were thought to only be dreams. In order to train ML models accurately, they require mountains of information to work with, but sometimes it becomes impossible to collect the data needed, so we turn to data augmentation. In this project we use a conditional variational auto encoder to supplement the original video electrochemiluminescence biosensor dataset, in order to increase the accuracy of a future classification model. In other words, using a cVAE we will create unique realistic videos …

Exploring The Efficiency Of Neural Architecture Search (Nas) Modules, Joshua Dulcich

Honors Theses

Machine learning is obscure and expensive to develop. Neural architecture search (NAS) algorithms automate this process by learning to create premier ML networks, minimizing the bias and necessity of human experts. From this recently emerging field, most research has focused on optimizing a promisingly unique combination of NAS’s three segments. Despite regularly acquiring state of the art results, this practice sacrifices computing time and resources for slight increases in accuracy; this also obstructs performance comparison across papers. To resolve this issue, we use NASLib’s modular library to test the efficiency per module in a unique subset of combinations. Each NAS …

Survivability Analysis In The Shadow Of Apollo: Part Ii - Spacecraft Charging Vulnerability Near The Stable Earth-Moon Lagrange Points, Robert A. Bettinger, Nathan R. Boone, Nicholas S. Hamilton, Bryan D. Little

Faculty Publications

Though the reality of routine travel and sustained operations in space likely remains several decades away, the building blocks of space exploration and space system development necessary to realize this reality are currently being laid by peer, near-peer, and emerging space-faring nations. The pursuance of sustained cislunar space operations will necessitate a renewed examination of spacecraft survivability and the capability of spacecraft to avoid and/or withstand the natural and manmade environmental risks posed by this “new” ultimate high ground.

Pseudo-Modal Expansions For Generating Random Electromagnetic Beams, Milo W. Hyde Iv, Olga Korotkova

Faculty Publications

Excerpt: We derive two pseudo-modal expansions that provide insight into the structure of stationary electromagnetic sources and can be used for their physical realization and in computer simulations. Both expansions are derived from the vectorial version of Bochner’s theorem of functional analysis.

Biomechanical And Psychological Predictors Of Failure In The Air Force Physical Fitness Test, Jeffrey Turner, Brent T. Langhals, Torrey J. Wagner

Faculty Publications

Physical fitness is a pillar of U.S. Air Force (USAF) readiness and ensures that Airmen can fulfill their assigned mission and be fit to deploy in any environment. The USAF assesses the fitness of service members on a periodic basis, and discharge can result from failed assessments. In this study, a 21-feature dataset was analyzed related to 223 active-duty Airmen who participated in a comprehensive mental and social health survey, body composition assessment, and physical performance battery. Graphical analysis revealed pass/fail trends related to body composition and obesity. Logistic regression and limited-capacity neural network algorithms were then applied to predict …

The Professional Constructor, Full Issue, Volume 47, Number 01

The Professional Constructor

No abstract provided.

Aerial Radiation Detection Identification And Measurement System Detector Material Comparison Study, Benjamin C. Troxell, Kacey D. Mcgee, Christina L. Dugan

Faculty Publications

The 20th Chemical Biological Radiological Nuclear and Explosives Command (CBRNE) currently utilizes an airborne sodium iodide gamma and beta detection system to map radiation fields over large areas of interest. The 20th CBRNE explored emergent detector technologies utilizing two detection materials; thallium-activated cesium iodide and high purity germanium (HPGe). These detectors were simulated at various altitudes and compared to background measurements. The sodium iodide detector failed to provide isotopic discrimination at distance. The thallium-activated cesium iodide CsI(Tl) detector provided sufficient absolute efficiency and energy resolution to identify isotopics at distance. The HPGe detector provided the best energy resolution. However, current …

Macrophage-Targeted Anti-Ccl2 Immunotherapy Enhances Tumor Sensitivity To 5-Fluorouracil In A Balb/C-Ct26 Murine Colon Carcinoma Model Measured Using Diffuse Reflectance Spectroscopy, Shelby N. Bess, Gage J. Greening, Narasimhan Rajaram, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Background

Immunotherapy in colorectal cancer (CRC) regulates specific immune checkpoints and, when used in combination with chemotherapy, can improve patient prognosis. One specific immune checkpoint is the recruitment of circulating monocytes that differentiate into tumor-associated macrophages (TAMs) and promote tumor angiogenesis. Changes in vascularization can be non-invasively assessed via diffuse reflectance spectroscopy using hemoglobin concentrations and oxygenation in a localized tumor volume. In this study, we examine whether blockade of monocyte recruitment via CCL2 (macrophage chemoattractant protein-1) leads to enhanced sensitivity of 5-fluorouracil (5-FU) in a CT26-Balb/c mouse model of CRC. It was hypothesized that the blockade of TAMs will …

Process- And Product-Related Foulants In Virus Filtration, Solomon Isu, Xianghong Qian, Andrew L. Zydney, S. Ranil Wickramasinghe

Biomedical Engineering Faculty Publications and Presentations

Regulatory authorities place stringent guidelines on the removal of contaminants during the manufacture of biopharmaceutical products. Monoclonal antibodies, Fc-fusion proteins, and other mammalian cell-derived biotherapeutics are heterogeneous molecules that are validated based on the production process and not on molecular homogeneity. Validation of clearance of potential contamination by viruses is a major challenge during the downstream purification of these therapeutics. Virus filtration is a single-use, size-based separation process in which the contaminating virus particles are retained while the therapeutic molecules pass through the membrane pores. Virus filtration is routinely used as part of the overall virus clearance strategy. Compromised performance …