Engineering Commons^™

Computationally-Driven Insights Into The Ligand Environments Of Materials For Catalysis And Separations, Stephen Vicchio

All Dissertations

Designing new catalytic and sorption materials is necessary to limit global temperature rise below 1.5 ◦C by 2050, while also meeting global energy demands. Climate change and energy production are not mutually exclusive; global population growth has direct impacts on global energy demands and climate. In both catalysis and adsorption applications, new technologies are needed to address these challenges. Catalysis can provide alternate, low-energy routes for converting low-value gases into higher-value chemical commodities, thus altering our current energy production. Likewise, new sorption materials can capture previously emitted CO₂ from decades of energy production from fossil fuels, thus helping to …

Atomistic And Mesoscale Modeling Of Microstructure Development During Solid-State Sintering, Omar Hussein

All Dissertations

Interfaces are ubiquitous in materials systems, and they influence the processing and properties of nearly all engineering and functional materials. Examples include grain boundaries (GBs) in polycrystalline materials, free surfaces in nanoparticles, and phase boundaries in multiphase materials. Therefore, understanding and controlling interfacial processes is a key aspect of materials design and discovery efforts.

Recent developments in advanced manufacturing and synthesis techniques have enabled the fabrication of materials architectures with intricate nanoscale features. Of particular interest is solid-state sintering, known for creating complex and high-precision geometries with controlled microstructures. While sintering science has been the subject of active research, very …

A Tessellation Of Engineers, Grace Jenkins Welsh

University Honors Theses

A capstone project is the culmination of what a student has learned while pursuing an undergraduate degree. A project of this magnitude requires a lot of time and dedication from every member of the team. This essay looks back at the experience of an electrical engineering student participating in the design of an auxiliary power and protection of a planned substation. The author describes the team's work, how they performed as a team, and their involvement with the professional sponsor and advisor. The author examines the experience with the goal of informing and encouraging prospective engineering students who may be …

Evaluating The Impact Of Oyster Reef Breakwaters On Hydrodynamics, Morphodynamics, And Sediment Transport Using Xbeach, Tabassum Islam

<strong> Theses and Dissertations </strong>

Alabama Port is a unique marsh and sandy beach shoreline. Since the 1950s, substantial erosion has occurred along this shoreline due to storms, wind-generated waves, and ship wakes. This research focuses on evaluating the effect of oyster reef breakwaters on wave height attenuation and sediment stabilization through numerical modeling (XBeach) under three different synthetic storm scenarios coupled with three unique sea level rise projections near Alabama Port. This has been accomplished by comparing a with and without project condition using XBeach in a two-dimensional (2D) mode by analyzing wave height, velocity, and cumulative bed-level changes at the study site. The …

Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye

<strong> Theses and Dissertations </strong>

In recent years, several substorm onset criteria have been developed, either from auroral observations (many authors) or from auroral electrojet properties such as those described by (Forsyth et al., 2015; Maimaiti et al., 2019; Newell & Gjerloev, 2011; Partamies et al., 2011) The different criteria are being investigated using a low order physics model of the magnetosphere called WINDMI (Spencer et al., 2009) and inferences are being made in line with the WINDMI model. The model variables will be compared with the criteria for substorm onset proposed by examining the SML index.

The WINDMI model uses solar wind and IMF …

Examining The Efficacy Of Using Irt As An Nde Method For Cfrp And Ztcfrp Composites, William Wyatt Taylor

<strong> Theses and Dissertations </strong>

A film adhesive is commonly used to form the bond-line between composite parts. The bond-line's quality and performance can be affected by defects such as voids, impurities, and agglomerations. Identifying these defects is possible with non-destructive evaluation testing (NDE). In this thesis, the joule-heating effect (JH) through carbon nanofiber (CNF) and carbon nanotube (CNT) modified film adhesive bonded to control carbon fiber reinforced polymer (CCFRP) was used along with infrared thermography testing (IRT) for bond-line defect inspection as a preliminary study. Due to the difference in the electrical conductivity between the modified epoxy and the defect, JH can cause a …

Extremum Seeking Control Algorithms For Extremely High Frequency Antenna System Pointing, Scott Shore

Mechanical Engineering ETDs

The research examines the application of extremum seeking control (ESC) algorithms to ground station antenna pointing for extremely high frequency (EHF) communication systems. ESC algorithms search for local maxima or minima by locating where an objective function gradient goes to zero. With wireless communication expanding into higher frequencies, the ground station pointing requirement is increasing. ESC presents a method which utilizes available equipment and information to perform ground station pointing. Additionally, ESC algorithms do not rely on assumptions or approximations needed for other techniques. The dissertation demonstrates ESC algorithm feasibility for the ground station pointing problem, benchmarks the ESC algorithms …

Electrical Characteristics Of In-House Produced Micro/Nanodielectrics, Dewan Mahmudullah

<strong> Theses and Dissertations </strong>

Dielectric characterization is very important across a wide range of applications, including the design and optimization of capacitors, electrical insulation, and electronic devices. It plays a vital role in providing valuable insights for material selection, performance evaluation, and the development of advanced dielectrics. The permittivity of dielectrics is a fundamental property of dielectric materials that quantifies their ability to store and dissipate energy in the presence of an electric field. Studies for developing advanced dielectrics and accurate measurements of the dielectric constant are essential for understanding and optimizing the performance of various electrical and electronic systems. The objective of this …

Embracing Identities And Affirming Agency: Exploring Effective Mentorship For Women Doctoral Students In Engineering Disciplines Using An Intersectional Lens, Jennifer Brown

All Dissertations

Positive mentoring experiences are crucial for retaining and advancing those who hold marginalized identities in STEM, as they foster a greater sense of belonging and self-efficacy that encourage these students to persist in their fields. Marginalized identities in STEM include, but are not limited to, women, BIPOC (Black, Indigenous, and People of Color), low-income, first-generation, neurodivergent, and members of the LGBTQ+ community. Oftentimes, these identities intersect, introduce additional nuance in interactions within engineering spaces, and affect the mentoring support that both mentees and their mentors require.

Prior research has shown the reciprocal value that is created when graduate students are …

Physics-Based Machine Learning Methods For Control And Sensing In Fish-Like Robots, Colin Rodwell

All Dissertations

Underwater robots are important for the construction and maintenance of underwater infrastructure, underwater resource extraction, and defense. However, they currently fall far behind biological swimmers such as fish in agility, efficiency, and sensing capabilities. As a result, mimicking the capabilities of biological swimmers has become an area of significant research interest. In this work, we focus specifically on improving the control and sensing capabilities of fish-like robots.

Our control work focuses on using the Chaplygin sleigh, a two-dimensional nonholonomic system which has been used to model fish-like swimming, as part of a curriculum to train a reinforcement learning agent to …

Hpc-Enabled Fast And Configurable Dynamic Simulation, Analysis, And Learning For Complex Power System Adaptation And Control, Cong Wang

All Dissertations

This dissertation presents an HPC-enabled fast and configurable dynamic simulation, analysis, and learning framework for complex power system adaptation and control. Dynamic simulation for a large transmission system comprising thousands of buses and branches implies the latency of complicated numerical computations. However, faster-than-real-time execution is often required to provide timely support for power system planning and operation. The traditional approaches for speeding up the simulation demand extensive computing facilities such as CPU-based multi-core supercomputers, resulting in heavily resource-dependent solutions. In this work, by coupling the Message Passing Interface (MPI) protocol with an advanced heterogeneous programming environment, further acceleration can be …

Improving Sizing Resolution Of Particle Impactors In The Nanoparticle Range, Shivuday Kala

All Dissertations

The application of particle size measurement extends across many fields: air quality measurement, pharmaceutical studies, paint and coating production, and nanoparticle formulation to name a few. Therefore, accurate measurement of nanoparticles is critical to aerosol science. While devices currently exist that can size and count nanoparticles such as electrical mobility spectrometers, dynamic light scattering devices, and small angle X-ray scattering devices, their high costs, complex operation, and lack of outdoor usability, restrict their use in practical applications. Among the devices that can size aerosols down to the nanoscale, cascade impactors stand out because of their robustness, relatively simple design, low …

Development Of Scope Of Services For Procurement Of Professional Consultant Services On Transportation Projects – A Study Of South Carolina Department Of Transportation, Ajay Jadhav

All Dissertations

Project Scoping Process (PSP) is one of the significant steps that starts at the very beginning of the project life cycle. During project initiation phase, project scoping is kicked off which includes documenting a list of project-specific goals, deliverables, tasks, costs, and deadlines. The scoping phase duration depends on the project complexity and involves various stakeholders, establishing team, confirming the project purpose and need, initiating the environmental revie process, determining the level of environmental documentation and permit requirements, conducting survey, identifying project risks and tools to mitigate them, and evaluating public involvement strategies. A well-defined PSP is therefore essential for …

Atomistic And Mesoscale Modeling Of Microstructure Development During Solid-State Sintering, Omar Marwan Isa Hussein

All Dissertations

Interfaces are ubiquitous in materials systems, and they influence the processing and properties of nearly all engineering and functional materials. Examples include grain boundaries (GBs) in polycrystalline materials, free surfaces in nanoparticles, and phase boundaries in multiphase materials. Therefore, understanding and controlling interfacial processes is a key aspect of materials design and discovery efforts. Recent developments in advanced manufacturing and synthesis techniques have enabled the fabrication of materials architectures with intricate nanoscale features. Of particular interest is solid-state sintering, known for creating complex and high-precision geometries with controlled microstructures. While sintering science has been the subject of active research, very …

Controlled Manipulation And Transport By Microswimmers In Stokes Flows, Jake Buzhardt

All Dissertations

Remotely actuated microscale swimming robots have the potential to revolutionize many aspects of biomedicine. However, for the longterm goals of this field of research to be achievable, it is necessary to develop modelling, simulation, and control strategies which effectively and efficiently account for not only the motion of individual swimmers, but also the complex interactions of such swimmers with their environment including other nearby swimmers, boundaries, other cargo and passive particles, and the fluid medium itself. The aim of this thesis is to study these problems in simulation from the perspective of controls and dynamical systems, with a particular focus …

Damage Detection With An Integrated Smart Composite Using A Magnetostriction-Based Nondestructive Evaluation Method: Integrating Machine Learning For Prediction, Christopher Nelon

All Dissertations

The development of composite materials for structural components necessitates methods for evaluating and characterizing their damage states after encountering loading conditions. Laminates fabricated from carbon fiber reinforced polymers (CFRPs) are lightweight alternatives to metallic plates; thus, their usage has increased in performance industries such as aerospace and automotive. Additive manufacturing (AM) has experienced a similar growth as composite material inclusion because of its advantages over traditional manufacturing methods. Fabrication with composite laminates and additive manufacturing, specifically fused filament fabrication (fused deposition modeling), requires material to be placed layer-by-layer. If adjacent plies/layers lose adhesion during fabrication or operational usage, the strength …

Synthesis Of Glucomannan-Xylan Composite Biofilms: Characterization And Applications For Food Packaging, Kholoud Al-Ajlouni

Dissertations

Scientists are most concerned about the need for green alternatives for efficient food packaging polymers to replace petroleum-based packaging products. The waste of corn cobs and the roots of the konjac plant contain hemicellulose, xylan and glucomannan respectively, and can be used to produce biofilms for food packaging.

The aim of these studies is to formulate biofilms from glucomannan-xylan blends that compete with petroleum-based plastic wrap. The biofilms must be strong, smooth, transparent, have a water vapor barrier, have the required mechanical properties and be cheap. Biofilms from glucomannan were stiff, lacked mechanical properties, and absorbed moisture. Therefore, it reacts …

A Multi-Objective Stochastic Programming Model For Resilient And Sustainable Supply Chains Under Uncertainty, Mohammad H. Majdfaghihi

Dissertations

Supply chain resilience (SCRES) and sustainable supply chain management (SSCM) have garnered significant attention in the field of Supply Chain Management (SCM) science. This heightened interest is largely attributable to the increasing frequency and severity of uncertainty and disruptions in global supply chains. Resilience is a beneficial approach to managing uncertainties and preparing for and mitigating the adverse consequences of Supply Chain (SC) disruptions. Sustainability is a key concept in SCM, driven by governmental regulations and heightened stakeholder and customer concerns for environmental and societal well-being. Studies on SCRES have traditionally focused on preparing for and reacting to disruptions and …

Towards A Spaceworthy Cots Graphics Processing Unit: Hardware Performance Counter Based Symptomatic Fault Detection, Antonio E. Teijeiro

Open Access Theses & Dissertations

Ionizing radiation remains an obstacle to bringing graphics processing units (GPU) to space. Since radiation-hardened GPU chips are technically infeasible at the moment, an emphasis has been placed on the adaptation of commercial-off-the-shelf (COTS) GPUs to the space domain. At present, GPU error detection methods require redundant computation. This thesis work explores the utilization of hardware performance counters, special registers useful for monitoring internal GPU hardware events, for symptom-based, lightweight error detection. Hardware performance counters are successfully utilized for the detection of anomalous single event upsets in the L0 instruction cache, the load store unit, the arithmetic and logic unit, …

Machine Learning For Kalman Filter Tuning Prediction In Gps/Ins Trajectory Estimation, Peter Wright

Electronic Theses, Projects, and Dissertations

This project is an exploration and implementation of an application using Machine Learning (ML) and Artificial Intelligence (AI) techniques which would be capable of automatically tuning Kalman-Filter parameters used in post-flight trajectory estimation software at Edwards Air Force Base (EAFB), CA. The scope of the work in this paper is to design and develop a skeleton application with modular design, where various AI/ML modules could be developed to plug-in to the application for tuning-switch prediction.

Surface Location Error In Robotic Milling: Modeling And Experiments, Richard Henry Swan Jr.

Masters Theses

Robotic milling offers new opportunities for discrete part manufacturing as an alternative to milling using large conventional machine tools. The advantage of industrial robots is their large work volume, configurability, and comparatively low cost. However, robots are significantly less stiff than conventional machine tools, which can lead to poor surface finish, low machining accuracy, and low material removal rates. The purpose of this research is to predict the geometric errors, or surface location errors, that occur in a robotic mulling tool path, validate these predictions with machining tests, and compensate these errors by tool path modification. Compared with conventional machine …

Investigating Mems Devices In Flow Conditions Relevant To Flow-Through Systems., Mohammad Shafquatul Islam

Electronic Theses and Dissertations

Advancements in microscale actuating technologies has substantially expanded the possibilities of interacting with the surrounding environment. Microstructures that deflect in response to mechanical forces are one of the largest application areas of microelectromechanical systems (MEMS). MEMS devices, functioning as sensors, actuators, and support structures, find applications in inertial sensors, pressure sensors, chemical sensors, and robotics, among others. Driven by the critical role of catalytic membrane reactors, this dissertation aims to evaluate enzyme activity on polymeric membranes and explore how fabrication methods from the field of Electrical and Computer Engineering (ECE) can incorporate sensing and actuation into these porous surfaces. Toward …

Synergistic Strategies In Sinter-Based Material Extrusion (Mex) 3d Printing Of Copper: Process Development, Product Design, Predictive Maps And Models., Kameswara Pavan Kumar Ajjarapu

Electronic Theses and Dissertations

3D printing pure copper with high electrical conductivity and exceptional density has long been challenging. While laser-based additive manufacturing technologies suffered due to copper's highly reflective nature towards laser beams, parts printed via binder-assisted technologies failed to reach over 90% IACS (International Annealed Copper Standard), electrical conductivity. Although promising techniques such as binder jetting, filament, and pellet-based 3D printing that can print copper exist, they however still face difficulties in achieving both high sintered densities and electrical conductivity values. This is due to a lack of comprehensive understanding of property evolution from green to sintered states and the strategies that …

Quantification Of Tumor Biophysical Heterogeneity Through Mechanical And Ultrastructural Analysis., Bradley James Mahaffey

Electronic Theses and Dissertations

Glioblastoma (GBM) is a highly invasive, aggressive brain cancer that carries a median survival of 15 months. This poor prognosis is due, in part, to its resistance to standard therapeutic intervention. Recent studies have demonstrated that tumor heterogeneity plays a critical role in facilitation therapy resistance by mediating tumor adaptation through microenvironmental cues. Efforts to describe these microenvironmental differences may aid in the development of strategies to combat resistance. GBM can be separated into two distinct regions – a core and a rim, which are thought to drive specific aspects of tumor evolution. The core is proliferative as evidenced by …

A Modular Framework For Surface-Embedded Actuation And Optical Sensing In Soft Robots., Paul Bupe Jr

Electronic Theses and Dissertations

This dissertation explores the development and integration of modular technologies in soft robotics, with a focus on the OptiGap sensor system. OptiGap serves as a simple, flexible, cost-effective solution for real-time sensing of bending and deformation, validated through simulation and experimentation. Working as part of an emerging category of soft robotics called Soft, Curved, Reconfigurable, Anisotropic Mechanisms, or SCRAMs, this research also introduces the Thermally-Activated SCRAM Limb (TASL) technology, which employs shape-memory alloy (SMA) wire embedded in curved sheets for surface actuation and served as the initial inspiration for OptiGap. In addition, the EneGate system is presented as a complementary …

Gps-Denied Navigation Using Synthetic Aperture Radar, Tucker Hathaway

All Graduate Theses and Dissertations, Fall 2023 to Present

In most modern navigation systems, GPS is used to determine the precise location of the vehicle; however, GPS signals can easily be blocked, jammed, or spoofed. These signals can be blocked by canyons or tall buildings. Additionally, adversaries can transmit signals that either make GPS signals difficult to interpret or that imitate real GPS signals and cause a navigation system to think it is somewhere other than its true location. GPS-denied (GPS-D) navigation is the process of navigating in the absence of GPS.

Many methods of performing GPS-D navigation have been proposed and explored. One such method is to use …

Subjective Wellbeing Of Undergraduate Engineering Students: A Mixed Methods Study, Muhammad Asghar

All Graduate Theses and Dissertations, Fall 2023 to Present

In higher education, the prevalence of mental health issues among students has raised concerns regarding their overall success and wellbeing. While existing research often focuses on identifying and addressing mental health problems, there is a lack of emphasis on understanding the positive contributors to students' mental health. In this study, I expand the concept of mental health beyond the absence of negative mental health states to include the presence of positive mental health aspects through the concept of Subjective Wellbeing (SWB) (feeling that your life is going well, not badly), of engineering undergraduate participants. Both qualitative and quantitative data were …

Cost Minimizing Energy Management Control Scheme For Microgrids Considering Dynamic Electricity Prices, Levi T. Miller

All Graduate Theses and Dissertations, Fall 2023 to Present

As countries develop and technology improves, the world is using more energy than ever before. This fact along with several other political, social, and economic factors has resulted in simultaneous energy and climate crises. A partial solution to both problems is bringing clean energy sources of electricity closer to the customers who use that energy. A microgrid is a smaller version of the national electric grid where smaller electricity generators are networked with local consumers and controlled independently of the main grid. Because control of electricity sources and loads are transferred to local controllers, the flexibility with which they can …

Effects Of Indole Derivative Idc16 On Cell Proliferation, Transfection, And Alternative Splicing In Production Of Lentiviral Vectors By Transient Co-Transfection, Nataly Mier

All Graduate Theses and Dissertations, Fall 2023 to Present

Viruses can efficiently introduce genetic material into a variety of cells through cell infection. Therefore, viral vectors, defined as virus-based gene delivery systems, effectively transfer functional gene constructs to target cells. Among different viral vectors, lentiviral vectors are of interest due to the advantages offered to research and therapeutic applications. Low productivity of lentiviral vectors in mammalian producer cells and high production cost, however, remain barriers to the vectors’ routinary use, particularly in clinical settings.

Since most lentiviral vectors are derived from human immunodeficiency virus type I, their genome has been engineered to increase safety. Nevertheless, modifications of the lentiviral …

Quantifying The Effect Of Stable Stratification On Low-Reynolds Number Flow Past A Horizontal Cylinder, Holland Kartchner

All Graduate Theses and Dissertations, Fall 2023 to Present

In this research, we study the behavior of flow around a cylinder in the presence of stable stratification, which refers to variations in density throughout the fluid. This phenomenon is observed in natural and industrial settings. We use computer simulations to analyze how stratification affects the flow patterns created by the cylinder. Specifically, we investigate situations where the stratification is perpendicular to the flow direction, and the wake exhibits two-dimensional characteristics. We use spectral-element method based computational fluids dynamics to simulate the phenomena. During the simulations, we vary two important parameters: the Densimetric Froude Number (Fr) and the …