Engineering Commons^™

Synthesis Of Lithium Nickel Cobalt Manganese Oxide (Ncm) Cathodes For Lithium-Ion Batteries, Jethrine H. Mugumya

Theses and Dissertations

There are various ways to produce lithium nickel manganese cobalt oxide (NCM) based cathodes for lithium-ion batteries, among them; co-precipitation synthesis carried out in tank-based reactors followed by lithiation is commonly employed because of its cost-effectiveness and scalability. Although it is the preferred synthesis method, it has several issues and challenges. Discussed in this dissertation are some of these issues as well as potential solutions. Physical and chemical properties of the co-precipitation product such as yield, particle size, morphology, and tap density, depend on various reaction parameters, which include pH, chelating agents, metal salt concentrations, and stirring speed. In the …

Muscle-Nerve Signaling And Its Role In Myogenesis, Synaptogenesis, And Regeneration, James T. Redden

Theses and Dissertations

Despite only comprising 0.1% of the myofiber surface area, a healthy motor endplate is densely packed with acetylcholine receptors (AChRs) responsible for mediating activity between the connected motor neuron and skeletal muscle via the neurotransmitter, acetylcholine. Loss of the endplate, known as fragmentation, is caused by car crashes, deep lacerations, and other traumatic injuries to the innervating nerve or direct injuries to the limb muscle(s) with intramuscular denervation as a common comorbidity. In both cases, endplate fragmentation begins within a week of injury proceeding muscle atrophy causing decreased mobility, paralysis, and quality of life. Endplate fragmentation of intact muscle fibers …

Hybrid Design Approaches For Reconfigurable Em Structures, Jonathan D. Lundquist

Theses and Dissertations

The modern world is replete with reasons for employing reconfigurable electromagnetic (EM) structures, but some of the most pressing needs require advancements in power consumption, speed, and footprint [1]. Next generation air defense (NGAD) fighters could benefit from new electronic warfare (EW) countermeasures [2], as well as adaptive stealth technology [3], while doctors could benefit from reconfigurable microwave ablation antennas that can modify radiation pattern and input impedance to match changes in tissue during ablation and account for variations in tumor shapes [4]. The future of antennas, filters, and lenses is reconfigurable as real-world matters of life and death may …

Machine Learning Assisted Optimization For Calculation And Automated Tuning Of Antennas, Lauren Linkous

Theses and Dissertations

The Antenna Calculation and Autotuning Tool (AntennaCAT) software suite represents a significant advancement in the field of antenna design by automating the entire design, CAD, simulation, and optimization process compatible with several EM simulation software suites. It is the first comprehensive implementation of machine learning in this context. In particular, this work includes the capability to create and export structured datasets from the aforementioned EM software for iterative improvement and includes an expandable selection of optimizers.

T Cell Polarization Regulates The Inflammatory Response And Tissue Regeneration At The Peri-Implant Interface, Derek Avery

Theses and Dissertations

Unresolved healing and localized chronic inflammation are common occurrences after biomaterial implantation, resulting in unfavorable clinical outcomes such as implant failure or fibrous encapsulation. T cells are adaptive immune cells found in lymph nodes, thymus, spleen, bone marrow, and around biomaterials, significantly impacting the degree of inflammation and wound healing. T cells are vital for inflammatory cytokine production and modulation of innate immune cells, including neutrophils and macrophages. T cells can be differentiated into two primary subsets, CD4⁺ and CD8⁺ T cells, playing distinctive roles in various pathologies and disease states. While T cells have been characterized well …

Effect Of Annealing On Photoluminescence From Defects In Gan, Oleksandr Andrieiev

Theses and Dissertations

Annealing is a critical process in modern GaN technology, essential for achieving p-type conductivity by activating the Mg_Ga acceptor, as first demonstrated by Shuji Nakamura in the early 1990s. Despite the omnipresence of hydrogen as an impurity in GaN crystals, the precise mechanisms governing hydrogen diffusion and acceptor passivation remain only partially understood. The presented research investigates the effects of annealing-induced activation and hydrogen passivation on C and Be acceptors in GaN grown by MOCVD, HVPE, and MBE methods. We explored these effects by using several annealing techniques, gas compositions, and thermal regimes. A transient behavior between the C …

Bridging The Gap In Epsilon-Near-Zero Nonlinear Materials, Adam R. Ball

Theses and Dissertations

Studying how light and matter interact has been of interest to humans for thousands of years. From the invention of the first mirror, burning ants with a magnifying glass, to optical fiber communication, light has been central to mankind. Researchers have sought to take this to the extreme with nonlinear optics where intense laser light interacts with materials. The study of this thesis is to understand a new generation of materials that has come to light. Epsilon-near-zero (ENZ) materials have shown promise for ultrafast light manipulation in tandem with modern day CMOS compatible electronics. Here, I seek to bridge the …

Openfoam Computational Fluid Dynamic Modeling Of Plasma Expansion Into Vacuum, Robert B. Padgett

Theses and Dissertations

Nuclear weapons, and their effects, have been heavily studied with decades of data and information to create simulations and quantify the risks of their use. However, in the modern day, nuclear strikes pose new risks to precision electronics, power systems, and vital infrastructure. As such, simulations of nuclear weapon use are required due to nuclear weapon testing being prohibited. These simulations can incorporate testing practices, such as laboratory lasers, and computer simulation technology, such as OpenFOAM Computational Fluid Dynamics (CFD). The use of OpenFOAM CFD allows testing in an area that has never been tested with nuclear weapons before, specifically …

Multi-Magnetic Material Transcranial Magnetic Stimulation Coils Development And Electric Field Measurement & Modeling Using Machine Learning, Mohannad Tashli

Theses and Dissertations

Transcranial Magnetic Stimulation (TMS) is a safe, effective, and non-invasive therapy for treating several psychiatric and neurological disorders. TMS is Food and Drug Administration (FDA) approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic …

Fluid Flow And Thermal Performance Investigation Of Twisted Elliptical Tubes For Use In High Prandtl Number Systems, Connor F. Donlan

Theses and Dissertations

The development of clean energy systems is paramount to reducing mankind's climate impact. These clean energy systems include solar, wind, and nuclear power where nuclear power shows a reduced lifetime carbon dioxide footprint per kilowatt hour compared to other sources [102]. Advanced nuclear reactors, fusion energy systems, and concentrated solar power designers are looking at using molten salt heat transfer fluids and improved heat exchanger design to increase power production and efficiency of clean energy systems. The improving heat transfer within the main heat transfer components within advanced nuclear reactors will enable increased efficiencies and power production.

Heat transfer improvements …

Functional Monitoring For Run-Time Assurance Of A Real-Time Cyber Physical System, Matthew W. Gelber

Theses and Dissertations

As cyber-physical systems (CPS) become more integrated into everyday life, the security of these systems must also be considered during their development due to their ever-increasing importance. With the growth of physical components in the system, more autonomous control requirements, and increased dependence on proper functionality, verifying system safety and correct operation becomes increasingly difficult. CPS have become more complex through the combination of additional hardware and the resulting interconnected software in many layers, each requiring unique security solutions. One example of such a safety-critical CPS embedded system is the Flight Control System (FCS) of an Unmanned Aerial System (UAS). …

External Runtime Execution Monitoring Of A Cyber Physical System Via Trace Interfaces, Peter Vaughan Truslow

Theses and Dissertations

In the past two decades, Unmanned Aerial Systems have progressed from expensive military hardware or one-off custom builds, to include off-the-shelf drones that can be purchased for a rather affordable price and flown by nearly anyone. As the technology and performance have improved, the door is opened to applications that require operation in environments where the consequences for failure are high, such as operating in the navigable airspace or in urban environments, or with human passengers. This requires a great deal of trust in the reliability and integrity of the control systems of the aircraft. A method of monitoring the …

Towards The Automation Of Post-Processing Of Additive Manufacturing Using Collaborative Robots, Logan Schorr

Theses and Dissertations

Despite the incredible potential that collaborative robots have, they are underutilized in several industries that could benefit greatly. These specialized fields, such as additive manufacturing, face challenges that can be solved with the use of robotics, including advanced computer vision, end-effector tooling, and process refinement. My research aims to utilize collaborative robots in an effort to solve the above stated problems, for the specific fields of additive manufacturing. Specifically within this field is the automation of post-processing; this is normally completely manual, as the tools for automation are not sufficiently developed to handle the flexibility required for additive manufacturing. This …

Development And Evaluation Of Reactor Physics Transient Benchmarks For Molten Salt Reactors Based On The Molten Salt Reactor Experiment, Mohamed H. Elhareef

Theses and Dissertations

Molten salt reactors (MSRs) are a promising class of advanced nuclear reactors selected as

one of the generation IV reactors. This class of reactors employs a unique design, where fissile

material is dissolved in a molten salt mixture, serving as fuel and coolant of the reactor. The design

features high-temperature low-pressure operation and efficient heat transfer capability, which

leads to significant improvements in reactor thermal efficiency, safety, and waste management.

However, MSRs also have complex phenomena not observed in conventional reactors, such as

fission product transport in the circulating fuel loop. These phenomena impact neutron distribution

and reactivity feedback mechanisms …

Development Of Tio2/Nh2-Mil-125 Nanocomposite For The Removal Of Ciprofloxacin Under Induced Solar Irradiation, Bilkis Mojisola Ajiwokewu

Theses

This research focuses on the development and application of Metal-Organic Frameworks (MOFs)-based nanocomposites for the photocatalytic removal of pharmaceutical contaminants, with a specific emphasis on ciprofloxacin (CIP). The photocatalytic degradation of CIP was investigated using as-synthesized photocatalysts of TiO₂ nanowires (TiO₂NWs), bare MOF of NH₂-MIL-125, TiO₂NW/NH₂-MIL-125 composite, and Lanthanum (La)-doped composite. Intriguingly, the TiO₂NW/NH₂-MIL-125 composite exhibited the highest efficiency, achieving a photodegradation rate of 0.0111 min-1, surpassing the independent performances of bare MOF of NH₂-MIL-125 and TiO₂NW. The observed efficiency was attributed to …

Electrospun Pt-Tio₂ Nanofibers Doped With Hpa For Catalytic Hydrodeoxygenation, Amos Taiswa, Randy L. Maglinao, Jessica M. Andriolo, Sandeep Kumar, Jack L. Skinner

Civil & Environmental Engineering Faculty Publications

Electrospinning is utilized to fabricate catalytic nanofiber scaffold for biocrude upgrading in hydrodeoxygenation (HDO) following computational studies suggesting the need for nano-catalysts for efficient HDO conversion and selectivity. Here, Pt-TiO₂ nanofibers are fabricated through electrospinning, followed by wet impregnation with a heteropoly acid (HPA), tungstosilicic acid. Intensive heat treatments were incorporated during and after processes to obtain a HPA doped Pt-TiO₂ nano-catalyst. Catalytic HDO was performed in a batch reactor with phenol as the raw biocrude dissolved in hexadecane. The HPA doped Pt-TiO₂ catalyst demonstrated promising HDO performance of 37.2% conversion and a 78.9% selectivity to oxygen …

Compound Flooding Hazards Due To Storm Surge And Pluvial Flow In A Low-Gradient Coastal Region, Sunghoon Han, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Flood risk analyses often focus on a single flooding source, typically storm surge or rainfall-driven flooding, depending on the predominant threat. However, hurricanes frequently cause compound flooding through significant storm surges accompanied by heavy rainfall. This study employs a hydrodynamic model based on Delft3D-Flexible Mesh that couples flow, waves, and rainfall-driven flow to simulate five historical tropical cyclones in Virginia's southeast coastal region. These storms produced varying intensities of storm surge and rainfall in the study area. Model simulations, incorporating rainfall through a rain-on-grid approach, account for the dynamic interaction between storm tides, and pluvial flow and enable the definition …

Single-Atom Catalysts For Electrochemical Energy Conversion: Copper Single-Atom Catalyst For Oxygen Reduction Reaction And Quantification Of Site Density By Co Stripping Voltammetry, Dawatage Perera

Theses and Dissertations--Chemistry

Fuel cells are considered a promising technology for achieving cleaner and more sustainable energy production and utilization. However, one of the current major challenges is the economic viability associated with the extensive use of Pt group metal (PGM) catalysts, particularly on the cathode side. Therefore, non-PGM single-atom catalysts (SACs) have received considerable attention as alternatives for PGM catalysts in the oxygen reduction reaction (ORR), which occurs at the cathode of the fuel cell. Among various SAC structures, the non-PGM/nitrogen-doped carbon-based structure (M-N-C) stands out for its excellent ORR performance.

Chapter 2 illustrates the use of copper metal in place of …

Automation Of Productive Machinery. Bases For An Innovative Business Model, Carlos Guillermo Hernández-Cenzano, Angel Contreras-Cruz, Eduardo Humada-Tello

Engineering and Technology Management Faculty Publications and Presentations

Nowadays, some laboratories perform elastic properties tests for concrete or rock cores using equipment manufactured 50 years ago. The original data collection procedure uses analog and manual recordings, which can cause inaccuracies in the measurements taken during these trials The process is tedious and updated since each trial's measurement data is recorded manually. In this context, this study systematizes the process and proposes an automated data acquisition and recording system for this type of equipment, followed by a case study presenting a rock compression test.

Design And Analysis Of Coupler Installation Tooling With Computer Vision For Fermilab’S Single Spoke Resonator 2 Srf Cavity, Caleb T. Denton

Graduate Research Theses & Dissertations

Fermi National Laboratory (Fermilab) and the European Council for Nuclear Research (CERN), forerunners in the exploration of the subatomic world, are both in the process of improving their particle accelerators with the Proton Improvement Plan II at Fermilab and the High-Luminosity Large Hadron Collider Accelerator Upgrade Plan (HL-LHC AUP) at CERN. Both particle accelerators have cavities that serve to either accelerate the particle beam or guide it into an optimal position and have the need for radio frequency (RF) power couplers to generate the field that controls the particle beams. When installing the coupler onto the cavity, a reliable vacuum …

Applying Synchrotron Saxs And Xas To Study The Microstructure Of Energy Conversion And Storage Materials, Lingzhe Fang

Graduate Research Theses & Dissertations

The microstructure of energy conversion and storage materials is a key determinant of physical properties and electrochemical performance. Synchrotron X-ray techniques, with their strengths of high flux and exceptional brightness, play an irreplaceable role in understanding nano and sub-nano structures. This helps the study of reaction mechanisms and benefits material design in energy conversion and storage area. Electrifying CO2 transformation using renewable energy offers a carbon-neutral solution to CO2 recycling and fuel generation. Among various feedstocks from the CO2 reduction reaction, CO, HCOOH, and CH4 have approached the performance thresholds for industry implementation. The application of single atom catalysts (SACs) …

Evaluating Computational Reproducibility Of Jupyter Notebooks Using Machine Learning And Natural Language Processing, A S M Shahadat Hossain

Graduate Research Theses & Dissertations

In recent years, computational reproducibility, which refers to achieving consistent results upon rerunning an experiment, has become one of the major concerns of various research communities. Jupyter Notebook, as a web-based computational notebook application, offers useful features for running and publishing computational experiments through interactive environments. However, rerunning notebooks does not always reproduce the experimental results. This thesis aims to develop novel methods to evaluate reproducibility by comparing different types of outputs between original and rerun notebooks. It also explores the idea of using machine learning models to predict reproducibility of notebooks automatically without the need of rerunning them. Through …

Modeling And Performance Evaluation Of Traditional And Ai-Based Mppt Techniques For Photovoltaic Systems., Md Badruddaza

Graduate Research Theses & Dissertations

The efficiency levels to convert from sunlight to electricity are in the range up to 22% commercially, based on the technology used. Due to comparatively low efficiency of photovoltaic systems, it is imperative to extract maximum power from the PV module array. Thus, in solar PV system, tracking the module’s MPP (maximum power point) is crucial and at the same time challenging as well due to varying climatic conditions. This research focuses on the modeling and performance evaluation of traditional Maximum Power Point Tracking (MPPT) techniques and AI-Based MPPT algorithms in photovoltaic systems. It addresses the issue of dynamic adjustment …

Dna I-Motifs: Biophysical Characterization And Structure-Property Correlation As Foundation For Functional Material Design, Alexander Minasyan

Graduate Research Theses & Dissertations

Over the past decades, nucleic acids have emerged as crucial frameworks with significance in biological systems and functional material engineering. Cytosine-rich deoxyribonucleotide sequences can form quadruplex structures a.k.a. i-motifs. Recently, i-motifs have attracted scientific interest in biological and material design areas.

In this work, we systematically investigate an effect of structured and unstructured modifications such as hairpins, stems, loops and overhangs on the kinetic and thermodynamic properties of DNA i-motifs. We demonstrate that the modifications can influence i-motif’s stability and folding/unfolding rates: thus, double stranded stems and hairpins are the best at stabilizing i-motifs and increasing kinetic rates of folding. …

Producing Biocomposites From Hemp Residues, Mohammad Faghani

Graduate Research Theses & Dissertations

The significant environmental challenges posed by traditional fossil fuel-derived plastics necessitate the exploration of sustainable alternatives. The global production of plastic has dramatically increased from 2 million tons in 1950 to 368 million tons in 2019, with projections exceeding 600 million tons by 2025. By 2040, the greenhouse gas emissions from the lifecycle of these plastics are expected to consume 19% of the global carbon budget. The United States alone produces nearly twice as much plastic waste as China and more than the entire European Union combined, highlighting the urgency of finding eco-friendly solutions.

Biocomposites, combining natural fibers with either …

A One-Wheeled Robot For Exploring Rolling Disk Locomotion, David H. J. Schmidt

Graduate Research Theses & Dissertations

The work proposed in this thesis is motivated by observations of one-wheel vehicles called monocycles. Whereas the unicycle has the rider sitting on a seat above the wheel, the monocycle’s rider sits inside a large circular hoop that serves as the wheel. Due to the position of the rider inside the wheel, it lowers the overall center of mass of the vehicle below the center of the wheel. For this reason, the uncontrolled longitudinal (forward/backward, or drive axis) dynamics are stable. For modest speeds above a certain threshold, the lateral (side-to-side, or lean axis) dynamics of the monocycle are also …

Bidirectional In-Situ Analysis And Visualization Of Fluid Structure Interactions With Applications In Blood Flow, Nazariy Tishchenko

Graduate Research Theses & Dissertations

Interactive blood flow simulation has applications in the understanding of complex fluids,training medical professionals, diagnostics, and surgical procedure planning. Bidirectional in situ visualization and analysis are much needed to streamline the analysis of large-scale patient-specific blood flow simulations. The in situ component ensures the live visualization of the simulation results while the simulation is running, and the bidirectional component allows for real-time control and configuration of the simulation parameters (i.e., setting and retrieving the simulation parameters and data based on need). In this project, a highly accurate multiphysics simulation was instrumented to work with an existing bidirectional in situ framework. …

Machine Learning For Environmental Sustainability, Syeda Nyma Ferdous

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research proposes a comprehensive approach to address pressing challenges in environmental sustainability, agricultural residue management, using machine learning based approaches. Machine learning (ML) techniques have emerged as powerful tools for addressing environmental sustainability challenges by facilitating the analysis and prediction of ecological phenomena, and optimization of resource management strategies. The study explores the synergies between environmental sustainability and machine learning to develop a framework that leverages artificial intelligence techniques covering a wide range of tasks including crop residue management, soil CO2 flux prediction, and forest carbon system prediction for sustainable development. The study analyze various ML models, such as, …

Evaluating The Impact Of Ergonomic Interventions On Reducing Knee Musculoskeletal Disorder Risks During Residential Roof Shingle Installation: A Phase-Level Analysis, Nazia Zerin

Graduate Theses, Dissertations, and Problem Reports (ETD)

The prevalence of knee musculoskeletal disorders (MSDs) among roofers due to awkward kneeling postures during shingle installation is a well-recognized concern. While knee-saving interventions like knee savers (KSs) and knee pads (KPs) have shown the potential to reduce MSD risks, their effectiveness across different phases of shingle installation remains unknown. The objective of this study is to assess how interventions of KSs and KPs alleviate the risks of MSDs in the knees during various phases of shingle installation. These phases include (1) reaching for shingles, (2) placing shingles, (3) grabbing a nail gun, (4) moving to the first nailing position, …

Novel Membrane Materials For Nutrient Recovery From Nutrient-Rich Resources, Km Prottoy Shariar Piash

Graduate Theses, Dissertations, and Problem Reports (ETD)

Global demand for fertilizer production is expanding substantially to meet the food demand of an increasing world population. Anaerobic digestate (AD) of various centralized wastewater facilities contains substantial amounts of ammonium (NH₄⁺) (300-800 mg/L), potassium (K⁺) (13-120 mg/L), and phosphorus (P) (30-100 mg/L)- based nutrients. In addition to reducing energy costs and CO₂ emissions compared to conventional fertilizing raw material manufacturing, recovering nutrients from these waste streams could help mitigate problems such as eutrophication, which otherwise incurs billions of dollars losses to US economy annually. Apart from nutrients, wastewater streams also contain organic pollutants …