Engineering Commons^™

Virtual Prototyping Of Pebb Based Power Electronics System For Ground Vehicles, Yi Li

All Theses

Power electronics are heavily involved in power and energy systems in plenty of applications nowadays. The increase of demand brings more challenges into simulations for development. Considering the complexity of the systems and high frequency operational conditions, this paper presents comprehensive research on modeling, simulating, and validation on ground vehicle propulsion system applications.

To reduce the computational burden, the Power Electronics Building Blocks concept is utilized to simplify the structure of modeling under different conversion scenarios in ground vehicle systems. In addition, the Average and Switching versions models are included. To speedup the simulation, the engagement of advanced computing technique …

Modeling Heat Propagation And Thermal Enhanced Decay In A Solar Thermal Remediation System, Justin Trainor

All Theses

Low temperature solar thermal remediation is designed to accelerate ongoing biotic and abiotic treatment processes at a much lower temperature and cost than high temperature thermal remediation strategies. An array of borehole heat exchangers are used to circulate a solar-heated fluid through a closed-loop system of thermally conductive pipes. Thermal energy heats the surrounding contaminated zone through the process of thermal conduction which serves to enhance the degradation of the contaminant.

A three dimensional analytical solution was previously constructed to model heat propagation from borehole heat exchangers into the surrounding subsurface. The model utilizes a system of finite line sources …

Investigation Into The Load Transfer Mechanism Of Trees To Develop An Innovative Foundation Configuration Using 3d Finite Element Modeling, Kaleb Boland

All Theses

This study was inspired by a tree’s reliance on its root system that enables it to withstand a natural disaster, such as an extreme hydroclimatic event or hurricane. This curiosity has led to an investigation into what makes this possible, developing a new and innovative foundation configuration for infrastructure systems, and a new possible construction material and method. This study provides results on a material that does not have conventional testing procedures or standards: a tree root. The trees studied are common to the upstate of South Carolina, which are Pine, Sweetgum, and White Oak. According to the results, on …

Examining Biological Algal Harvest For Use In Clemson University’S Algal Carbon Capture System Using Freshwater Mussel Elliptio Complanata, Jack Grimes

All Theses

Capture of atmospheric carbon by freshwater algae is being proposed in Clemson University’s outdoor algal carbon capture system, formerly described as the Partitioned Aquaculture System (Drapcho and Brune, 2000). Several algal species have been present in the system, depending on cultivation conditions. However, mechanical harvesting of the algae has proven difficult because of the cost of chemical flocculants, the energy cost of filtration due to small particle size of algae, and the relatively dilute algal cell concentrations in the system. Prior research on algal filtration by freshwater mussels has indicated its potential for use as a biological filter. This research …

Integrated Energy-Aware Motion Planning And Charge Scheduling Of Unmanned Aerial Vehicles, Hayleyesus Alemayehu

All Theses

The growing demand for unmanned aerial vehicles (UAVs) is driven by their operational convenience, cost-effectiveness, availability, and adaptability to various scenarios. In energy-constrained environments, optimizing energy consumption and ensuring a continuous power supply for UAVs is crucial for mission success. The objective of this thesis is to address this issue by integrating energy-aware motion planning and charge scheduling for UAVs by utilizing a charger hosted on an unmanned ground vehicle (UGV), whose rendezvous locations and routes are jointly computed to minimize overall energy consumption.

This thesis proposes a hierarchical trajectory and control framework comprising local and global planners for each …

Design And Fabrication Of An Optical Blade Tip Timing Sensor, Nick Tomlinson

All Theses

Electricity is a vital energy source that powers modern technology. Turbines are heavily relied on in the electric power industry for the conversion of natural energy sources into electricity. These turbines operate under harsh conditions which increase the likelihood of blade damage. Structural health monitoring of a turbine’s blades is important to detect problems before a blade experiences failure. The blade tip timing method can be used to monitor blade vibrations and determine if damage has occurred. An optical blade tip timing sensor is designed and fabricated to advance the field of sensing in the power industry.

Preparation Of High Entropy Titanite Pyrochlore And Radiation Stability Study, Adam Gootgeld

All Theses

Pyrochlore has been studied as a host phase for safe storage of radionuclides and exists naturally with long-term stability with good long-range order [1]. High entropy oxides show promising tunable properties that could demonstrate favorable bulk deposit of radioactive materials such as spent nuclear fuel (Uranium and other actinides). It is proposed that using high entropy oxides (HEOs) as the cation in this framework will shift the gibbs free energy so that radioactive nuclear waste will be stabilized for safe, long-term, eco-friendly storage. We have established a consistent method to fabricate high entropy titanite pyrochlores. In this study, ion beam …

Towards Validating Satellite Remote Sensing Of Aerosols With Ground-Based Low-Cost Sensors, Francine Roberts

All Theses

Poor ambient air quality has significant impacts on the environment and human health. Extensive regulation and monitoring has resulted in improvements since the first iteration of the Clean Air Act was passed in 1955. However, work still needs to be done in regard to higher spatial and temporal monitoring. Temporally, sensors used for regulatory purposes often only report every other or every third day. Spatially, they are often spread across vast distances due to cost. The following research is working towards improving the spatiotemporal measurements of particulate matter (PM), specifically in South Carolina. The two methods available for improving the …

The Extent Of Drone Education Being Taught In Asc Schools To 4-Year Construction Students, Cheran Teja Dumpati

All Theses

The technology of Unmanned Aircraft Systems (UAS) is growing rapidly in many fields and has become one of the skills in demand in the industry. Universities are one of the primary sources of teaching drone technology with a career-oriented approach. The goal of this study is to investigate the content of the drone curriculum being taught in Associated Schools of Construction (ASC) schools. This includes the topics covered, practical training offered, and the key deliverables taught. This information serves as a foundation for the schools that are looking forward to start drone courses in their department. The research found that …

Characterization Of Mechanically Recycled Polylactic Acid (Pla) Filament For 3d-Printing By Evaluating Mechanical, Thermal, And Chemical Properties And Process Performance, Mahsa Shabani Samghabady

All Theses

Polylactic acid (PLA) is a biopolymer made from renewable resources such as sugar and corn. PLA filament is a popular material used in Fused Deposition Modeling (FDM) 3D-printing. While this material has many advantages, all the failed parts, support structures, rafts, nozzle tests, and the many prototype iterations during the 3D-printing process contribute to the plastic pollution and release of greenhouse gases. Although PLA is biodegradable, it can take years to degrade in landfills. Instead of throwing away PLA waste and buying new filaments, PLA can be recycled. Amongst the different recycling technologies, mechanical recycling is the most environmentally friendly. …

Dynamics And Steering Of A Vibration-Driven Bristle Bot In A Pipe System, Ian Stewart

All Theses

Soft vibrational robots are robots that incorporate compliant structures into their design and are driven by oscillating actuators. A recent, popular version of a soft vibrational robot is the bristle bot, which uses flexible bristles and a vibration motor to propel itself across surfaces and through pipes. This motion is primarily driven by stick-slip dynamics resulting from asymmetric frictional forces applied at the bristle tips. Depending on the frequency of vibration of the motor, the robot experiences various resonance regions allowing it to maneuver in different directions. Attaching bristles to all sides of the robot and placing it in a …

Examining Individuals' Use Of The Internet For Healthcare Activities Over Time: Statistical Analysis Of Nhis Data, Zachary Junkins

All Theses

Telehealth is an increasingly important component of healthcare services. Telehealth services may present an opportunity to increase the equity, accessibility, and effectiveness of healthcare. As such, it is critical that telehealth design focus on reducing the barriers to access and usability that may impair some telehealth users. I utilized data from the National Health Interview Survey (NHIS) and multiple logit regression models focused on different aspects of telehealth in order to determine demographic characteristics, behaviors, or opinions which may predict groups that are likely to face a barrier to using telehealth services. This analysis provides an exploratory look at the …

Photodynamic Therapy To Treat Triple Negative Breast Cancer In Vitro, Hunter S. Warren

All Theses

Triple negative breast cancer (TNBC) is the most resilient form of breast cancer, being one of the leading causes of death for women and making up 7% of all cancer deaths. Photodynamic therapy (PDT) offers a minimally invasive solution to TNBC as a passive-targeting treatment that reduces the need for other well established yet harsh treatments that can be taxing on the patient. PDT involves the use of a high-energy red light on the area of a tumor injected with photosensitizers (PS) that generate reactive oxygen species (ROS) in the tumor, triggering cell death. The PS tetra(hydroxyphenyl)chlorin (m-THPC) was used …

Carbon Fibers From Athabasca Oil-Sand Asphaltenes, Blake Reardon

All Theses

Carbon fibers possess ultra-high specific strength and modulus. Therefore, the material is popular in aerospace, automotive, and sports industries. Approximately 95% of all carbon fibers are spun from a high-cost precursor, polyacrylonitrile (PAN). There is a need for a cheaper grade of carbon fiber for low-cost applications because about half of carbon fiber cost is associated with precursor cost. A promising alternative to the high-cost PAN precursor is petroleum-based asphaltene. Asphaltenes are highly aromatic and have a high carbon content but lack the purity of the PAN precursor. Processes like the molten- sodium desulfurization upgrading have been used to harvest …

Augmented Human Inspired Phase Variable Using A Canonical Dynamical System, Timothy Driscoll

All Theses

Accurately parameterizing human gait is highly important in the continued development of assistive robotics, including but not limited to lower limb prostheses and exoskeletons. Previous studies introduce the idea of time-invariant real-time gait parameterization via human-inspired phase variables. The phase represents the location or percent of the gait cycle the user has progressed through. This thesis proposes an alternative approach for determining the gait phase leveraging previous methods and a canonical dynamical system.

Human subject experiments demonstrate the ability to accurately produce a phase variable corresponding to the human gait progression for various walking configurations. Configurations include changes in incline …

Experimental Investigation Of The Long-Term Bending Deflection And Creep Performance Of Cross-Laminated Timber (Clt), Aaron Desantis

All Theses

Rising popularity in mass timber construction for residential and commercial projects has escalated the need to develop and increase understanding of mass timber products both from a strength and serviceability perspective. For cross-laminated timber (CLT) there is a significant lack of research on the creep characteristics also known as long-term deflection behavior. Creep is particularly important for products such as CLT that are used for floors with longer spans. Full-scale creep testing was conducted using 5-ply CLT panels over the course of 6 months in a controlled environment under dry service condition. Testing resulted in average final deflections 1.73 times …

Healthcare Built Environment And The Covid-19 Pandemic, A Mixed-Method Study, Mohammad Saleh Nikooopayan Tak

All Theses

The outbreak of COVID-19 presented an unparalleled risk to public health, leading to urgent scientific efforts in understanding transmission mechanisms and mitigating risks, especially in healthcare settings. This mixed-methods study examines knowledge advancement regarding indoor air quality in healthcare facilities during the pandemic. A systematic literature review of 163 post-COVID studies identifies key research thrusts and 31 recommendations related to building ventilation, air filtration, surface disinfection, and monitoring. Comparison with over 200 pre-pandemic publications reveals both reliance on established infection control principles and unique contributions, such as detecting viral RNA in air and surface samples indicating potential airborne and fomite …

The Effects Of Compression Wrapping Techniques And Primary Wound Dressings On Leg Skin Interface Pressure, James Cox

All Theses

Peripheral edema affects approximately 20% of people in the US over the age of 50 and is frequently encountered among individuals with conditions such as heart disease, prolonged immobility, and venous insufficiency.¹ Compression is an established therapeutic tool utilized for the management of several chronic edema presentations including lymphedema and venous leg ulcers.^2,3 Therapeutic efficacy of compressive applications can be evaluated by defining interface pressure (IP) and IP distributions associated with specific textile combinations.² During compressive applications where an open wound is present, primary wound dressings should be used in combination with compressive wraps. Primary wound dressings …

The Effect Of Package Types On Fresh Peaches In The Direct-To-Consumer Distribution Environment, Brennan Lytle

All Theses

The direct-to-consumer (DTC) shipping mode presents new opportunity for fresh peach sales in North America where demand over the past four decades has steadily declined. The hazards in this distribution mode are severe, and fresh peaches are fragile emphasizing the need for proper protection. A full analysis that not only encompasses the effects of the direct-to-consumer distribution environment, but also incorporates analyses of the environmental and economic impact of the packages utilized for transit of peaches is necessary. In this study, we use the metrics of peach grade, firmness, soluble solids concentration, and percent softness before and after the distribution …

Design And Data-Driven Identification Of A Quadruped Robot, Dakota Rufino

All Theses

The existence of nonlinearities and the lack of sufficient equations are fundamental challenges in modeling, analyzing, and controlling complex systems. However, recent developments revolutionizing the study of dynamical systems. An emerging method in nonlinear dynamical systems is the Koopman operator theory, which provides us with key advantages in performing the modeling, prediction, and control of nonlinear systems. The linear system representation allows us to leverage linear stability analysis. The first section of this thesis briefly covers the construction of a quadrupedal robot, a sufficiently complex nonlinear dynamical system, for the use of analyzing data-driven modeling techniques. The second section details …

An In Vivo Biocompatibility Analysis Of A Novel Tissue Regeneration Matrix Using A Pig Model, Shamar Thomas

All Theses

The goal of this project is to develop an injectable bead scaffold to promote tissue regeneration in the void created by lumpectomy and to alleviate post lumpectomy problems by preventing local recurrence and minimizing surgical-related infections. Microbeads were synthesized from collagen type I and crosslinked with tannic acid to form the basis for this injectable therapeutic. Tannic acid acts as a therapeutic anticancer agent. The action mechanisms of tannins in breast cancer cells have been studied with studies showing tannins to be cytotoxic to cancer cells in a dose-dependent manner. Tannic acid induces apoptosis in breast cancer cells via caspase …

Comparative Design Space For Bistable Composites: An Integrated Framework Of Optimization, Finite Element Analysis, And Experimental Testing, Jonathan Bolanos

All Theses

Bistable composites are a class of advanced materials that can actuate between two stable shapes, making them attractive for a wide range of engineering applications. However, designing these composites to achieve optimal performance remains a challenging task. To address the challenge, this research develops an integrated framework that combines a genetic algorithm optimization technique, finite element analysis in Abaqus, and experimental testing to explore the design comparative space for square bistable composites composed of DA 409 carbon fibers. This leads to the study of generating an optimization algorithm to account for the relationship between the chances of a successful maximum …

Laser Stabilization Through Optical Turbulence, Liam Vanderschaaf

All Theses

Laser jitter presents a significant issue in the fields of laser communication and sensing. There are two main categories of positional noise in regards to the instantaneous centroid of a laser propagating over long distances: jitter resulting from optical turbulence and jitter resulting from mechanical vibrations. Optical turbulence was generated using Clemson University’s Variable Turbulence Generator (VTG). The VTG is capable of creating a desired level of optical turbulence that is comparable to atmospheric conditions with fried parameters greater than 0.3 cm. A gaussian laser was transmitted through the VTG and a system of Fast Steering Mirrors and Position Sensing …

A Hidden Spider Web Of Roots: Utilizing Ground Penetrating Radar To Uncover Laterally Expansive Roots Of An Oak Tree, Megan Lapkoff

All Theses

Roots are critical to understanding tree health, subsurface biomass, and overall tree root stability. However, accessing tree roots is difficult and traditional methods used to quantify roots harm or kill the tree. Ground penetrating radar (GPR) provides a non-invasive way to characterize subsurface roots without harming the tree. GPR provides high-resolution data and the ability to collect data with high spatial coverage, making it an ideal tool for characterizing roots. GPR works by detecting contrasts in dielectric permittivity or electromagnetic (EM) velocity at interfaces between materials. Small scattering objects, like roots, generate predictable artifacts called diffraction hyperbolas. Diffraction hyperbolas will …

Development And Evaluation Of Machine Learning Models For Fugitive Methane Detection And Intensity Prediction, Jacquan Pollard

All Theses

The environmental impacts of global warming driven by fugitive methane (CH4) emissions have catalyzed significant research initiatives in developing novel technologies that enable proactive and rapid detection of CH4 emissions. This study evaluated the performance of data-driven machine learning (ML) models using support vector machines (SVM) to detect the presence of trace CH4 emissions and the corresponding intensity amongst various meteorological conditions. The author used simulation data comprising various meteorological parameters such as temperature, relative humidity, wind speed, water vapor, pressure, precipitation rate, and a parameter possessing trace concentrations of CH4 emissions. The novelty of the SVM models developed in …

Evaluating The Effect Of Palmitic Acid Concentration On Growth And Inhibition Of Syntrophomonas Sp., Clancy Kerr

All Theses

Various industries produce fats, oils, and greases (FOG). These hydrophobic compounds cause issues in municipal wastewater collection and treatment systems. Anaerobic co-digestion is an effective way to treat FOG and presents an opportunity to produce more significant quantities of biogas. However, many microorganisms are sensitive to the degradation products like long-chain fatty acids (LCFAs). Palmitic acid is the most prevalent LCFA in anaerobic co-digestion of FOG and wastewater. Sytrophomonas is a β-oxidizer able to break down palmitic acid. Palmitic acid is known to feed and inhibit Syntrophomonas growth and methanogenesis. The objectives of this investigation are: To determine if Syntrophomonas …

Universal Short-Circuit And Open-Circuit Fault Detection For An Inverter, Buck Brown

All Theses

Short-circuit and open-circuit faults of an inverter’s power device often lead to catastrophic failure of the entire system if not detected and acted upon within a few microseconds, particularly for emerging wide bandgap (WGB) power semiconductors. While a significant amount of research has been done on the fast and accurate protection and detection of short-circuit faults, there has been less success corresponding to the research on open-circuit faults. Common downfalls include protection and detection that are too application-specific, take longer than a couple of microseconds, and are not cost-efficient. This study proposes a new open-circuit fault protection and detection system …

Network Effects Of Emergency Department Clinician Strain And Patient Congestion, Aisha Nelson

All Theses

We develop a discrete-event simulation model to study how staffing strain affects patient outcomes across a network of Emergency Departments (EDs). The aim is to observe how clinician staffing and transfers throughout the system affect the system’s behavior. We will study the network of the seven EDs in the Prisma Health-Upstate system. Patient acuity and resource need are stratified using the five-level Emergency Severity Index (ESI). Patient flow data within and between EDs are collected from EPIC, staffing data from ShiftAdmin, and environmental COVID-19 prevalence data from the Department of Health and Environmental Control. Time periods include the Omicron wave …

Systematic Literature Review Of Roof Systems On Energy Efficiency Of A Building To Support An Ideal Study Framework, Ayushi Raj Dua

All Theses

A sustainable building envelope is a crucial element to build energy efficient structures that contribute towards sustainable communities. The demand for sustainable building envelopes has grown in response to a growing emphasis on sustainable living. The roofing system is an important component of a sustainable building envelope because it influences the building's energy consumption and indoor comfort levels. The current study focuses on roofing systems and associated solar reflectance and albedo values to document the impact on energy efficiency via cooling/heating energy usage, dollar savings and temperature (ambient and surface) reductions due to the roofing systems. Additionally, the study focuses …

Improving Inference Speed Of Perception Systems In Autonomous Unmanned Ground Vehicles, Bradley Selee

All Theses

Autonomous vehicle (AV) development has become one of the largest research challenges in businesses and research institutions. While much research has been done, autonomous driving still requires extensive amounts of research due to its immense, multi-factorial difficulty. Autonomous vehicles rely on many complex systems to function, make accurate decisions, and, above all, provide maximum safety. One of the most crucial components of autonomous driving is the perception system.

The perception system allows the vehicle to identify its surroundings and make accurate, but safe, decisions through the use of computer vision techniques like object detection, image segmentation, and path planning. Due …