Engineering Commons^™

Design And Analysis Of A Single Stage, Traveling Wave, Thermoacoustic Engine For Bi-Directional Turbine Generator Integration, Mitchell Mcgaughy

All Theses

The demand for clean, sustainable, and cost-effective energy continues to increase due to global population growth and corresponding use of consumer products. Thermoacoustic technology potentially offers a sustainable and reliable solution to help address the continuing demand for electric power. A thermoacoustic device, operating on the principle of standing or traveling acoustic waves, can be designed as a heat pump or a prime mover system. The provision of heat to a thermoacoustic prime mover results in the generation of an acoustic wave that can be converted into electrical power.

Thermoacoustic devices offer highly reliable and transportable power generation with low …

Regeneration Of The Ventricular Endocardium Within Acellular Whole Rabbit Hearts Using A Layer-By-Layer Seeding Method, Clayton Lewis Compton

All Theses

In the United States, 1 out of every 9 death certificates in 2013 referenced heart failure.1 Despite the outstanding need of treatment options for heart failure, heart transplantation remains the optimal treatment method. However, there is a severe shortage of donor hearts available for transplantation.2 Other available treatment options are not ideal because they do not fully restore function and are associated with creating other complications.3 Thus, there is a need for developing a living tissue engineered whole heart for transplantation to provide an alternative option for patients on the waitlist to receive a donor heart.

Our solution is to …

Non-Newtonian Fabric-Fluid Composites: Fabrication, Characterization And Testing For Anti-Ballistics Applications, Hayley M. Weir

All Theses

This thesis aims to characterize non-Newtonian suspensions for anti-ballistics applications. This involves characterizing the rheological behavior of each suspension. It also includes characterizing the interactions of the suspensions with several types of fabrics with known antiballistics properties. The study also tests the armor composites under ballistics stresses by firing on them with standardized military weaponry. This data is then compiled to determine which, if any, of the fabrics and suspensions are ultimately suitable for anti-ballistics uses.

Determination Of Safe Ballasts For Anchoring Event Tents By Finite Element Analysis, Sandeep Manoharan

All Theses

Event tents are large structures made of fabric covers attached to a structural frame and poles. Every year, many temporarily installed tents are subjected to large wind conditions that lead to sliding or lift of the frame due to improper anchoring to the ground. When ballasted, as opposed to anchored using stakes that penetrate the ground, non-certified tents are generally installed without proper analysis of sufficient ballast weights, which results into tent movements and lack of safety. The objective of this thesis is to determine load factors for non-certified tents affected by high wind loads. The load requirements (load factors) …

Impacts Of Rail Transit Investments On Demographics And Land Use: 1990-2010, Aubrey Trinidad

All Theses

This paper studies the changes in land use and population characteristics around station areas following the building of rail transit stations in 14 major cities in the United States from 1990 to 2010. It answers the question: how have investments in US rail transit made since the 1990s affected land use and demographics? It also looks at the specific effects of investments on population density, race, and ethnicity, means of transportation, median housing value, median household income, vehicle access share, occupations, and land use represented by the share of multifamily versus single-family housing. Using block group level US census data …

The Effect Of Surface Roughness Modifications And Chitosan Surface Coatings On Biofilm Formation For Prevention Of Orthopaedic Infections, Nathan Dewayne Smith

All Theses

Infections have been reported to occur in up to 91% of patients after orthopaedic procedures. Many of these infections are caused by bacterial biofilm growth on the surface of the implanted device. Surface modifications of fracture fixation implants have been taken into consideration in order to reduce infection rates and improve clinical results in orthopaedic procedures. Effective surface treatments will also reduce the need for antibiotics and prevent formation of drug-resistant bacteria. Titanium alloy sample discs (N=144) were prepared with six surface roughness treatments through polishing as well as with four different concentrations of chitosan through spin coating. In vitro …

Nanoscale Solutions To Tailor Fiber Architectures For Realizing Composites With Triumvirate Properties, Vishnu Priya Ramineni

All Theses

The paramount need for the development of multifunctional, smart and adaptive material systems for application in industries like automobile, aeronautical and aerospace is undeniable. Polymer composites are fast becoming the primary material options to this demand in light of their superior mechanical properties, low density, high corrosion resistance and easy manufacturability. The design flexibility offered in terms of achieving higher specific properties and light weighting is the key reason behind their success. Among all the properties that composites possess, it is the stiffness, strength and toughness that most applications mandate. These properties however, provide complimentary and contrasting characteristics for composites …

Quantification Of Volatile Residuals In Polydioxanone By Gas Chromatography: Method Development, Validation And Implementation, Clayton Joseph Culbreath

All Theses

Bioresorbable polymers are increasingly utilized for implantable medical devices to avoid complications related to explant and/or long term responses to foreign materials. As with all polymeric materials, residual levels of unreacted monomer, and other volatiles, drastically affect the mechanical and chemical properties as well as the parameters required to process the material into a device. The 1,4-dioxane-2-one (PDO) monomer is a six membered ring that forms an ether-ester polymer via ring-opening polymerization (ROP) with intermediate absorption rate properties that are ideal for numerous implant situations. Developing devices using poly(1,4-dioxane-2-one) (PPDO, PDO, PDX, PPDX, or PDS) is complicated by residual levels …

Rare Earth Emissions From Polyethylene Terephthalate Fiber, Joshua Jenkins Furtick

All Theses

Rare earth-polymer blends can be useful in many applications including safety, security, displays, and novelty. Polyester, specifically polyethylene terephthalate, is a ubiquitous material in the world today and offers many opportunities for the usefulness of visible light rare earth emissions.

In this work we have attempted to incorporate rare earth complexes with polyester yarn using various methods including coating, extrusion, and dyeing, with the latter having the most success. Nanoparticles were used initially for these experiments, however certain limitations of the particles could not be overcome, for example the size of the particles and the incompatibility of the inorganic matrix …

Development And Initial Validation Of A Surgical Instrument For In Situ Mechanical Characterization Of Surgical Mesh-Tissue Composites, Jorge Ivan Hernandez Sanchez

All Theses

Approximately 5 million Americans have an abdominal wall hernia, and over 700,000 undergo surgical procedures every year to treat them. Surgical procedures have evolved with the goal of preventing recurrences, leading to the current gold standard of treatment: hernia repair with mesh. Hernia repair with mesh consists on augmenting the weakened abdominal wall by implanting a synthetic or biological mesh. Although the adoption of hernia repair with mesh has improved outcomes, recurrence from primary repair procedures with large incisions (>10 cm) remains an alarming 32%.

The wide variety of implanted surgical mesh (materials, structure) and surgical variability (attachment method, …

Autologous Protein Solution Exhibits Potential To Mitigate Osteoarthritis (Oa) Progression In A Human Explant Co-Culture Model, Kathleen Emily Steckbeck

All Theses

Osteoarthritis (OA) is a debilitating and painful disease that affects upwards of one in every eight adults1,2. OA influences the entire joint, but is traditionally characterized by cartilage degradation3. OA is a multifactorial disease with genetic, biological, and biochemical consideration, but there has been a recent shift in scientific opinion that the pathological progression of OA stems from an inflammatory milieu produced by the feed-forward progressive pathway as evidenced by simultaneous cartilage and synovium co-culture4–7. Autologous protein solution (APS) poses as an intriguing potential OA therapy by possessing a high anti-inflammatory and anabolic mediator concentration profile that could potentially mitigate …

Analysis Of Large Scale Pv Systems With Energy Storage To A Utility Grid, Joseph M. Lavalliere

All Theses

With electric distribution network operators experiencing an exponential increase in distributed energy resource connections to the power grid, operational challenges arise attributable to the traditional methods of building distribution feeders. Photovoltaic (PV) solar systems are the major contributor due to recent technological advancements. Though this renewable energy resource is beneficial to human society, unfavorable electrical conditions can arise from the inherit variability of solar energy. Extreme variability of power injection can force excessive operations of voltage regulation equipment and potentially degrade customer voltage quality. If managed and controlled properly, battery energy storage systems installed on a distribution feeder have the …

Fabrication And Characterization Of An Extracellular Matrix Hydrogel For Aortic Valve Applications, Brady Culbreth

All Theses

With an estimated 5 million people suffering from valve disease in the United, valve disease is currently the leading cause of cardiovascular disease. Each year, between 80,000 and 85,000 aortic valve replacements are performed in order to treat the stenotic heart valves. Despite this being a worldwide epidemic, the current valve replacement options that are on the market have distinct limitations. Furthermore, a viable alternative does not exist for the patients that are not candidates for the current treatment methods. Our proposed solution to this epidemic is to create a highly viable injectable scaffold that would allow for the minimally …

Design Of A Meta-Material With Targeted Nonlinear Deformation Response, Zachary Satterfield

All Theses

The M1 Abrams tank contains track pads consist of a high density rubber. This rubber fails prematurely due to heat buildup caused by the hysteretic nature of elastomers. It is therefore desired to replace this elastomer by a meta-material that has equivalent nonlinear deformation characteristics without this primary failure mode. A meta-material is an artificial material in the form of a periodic structure that exhibits behavior that differs from its constitutive material. After a thorough literature review, topology optimization was found as the only method used to design meta-materials. Further investigation determined topology optimization as an infeasible method to design …

An Examination Of Microbial Community Composition At Tba-Degrading Versus Non-Degrading Sites, Courtney Thompson

All Theses

Understanding how fuel oxygenates interact with microorganisms in the subsurface is important for the remediation of contaminated sites and designing and optimizing remedial strategies. The current understanding of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (TBA) degradation in the environment has been developed primarily through gas chromatography GC analysis and culture-based laboratory studies. Microbial communities can be very diverse, and while microcosm studies provide valuable data, few metagenomic studies have been performed. To elucidate the significant microorganisms and pathways involved in the breakdown of MTBE and TBA, the compositions of entire indigenous microbial populations must be investigated and …

Experimental Investigation Of Heat Leakage And Air Leakage In Domestic Refrigerators, Shervin Shoai Naini

All Theses

The optimization of the energy consumption in household refrigerators should consider the influence of the gasket which determines the heat transfer and air infiltration rate. In this research project, engineering methods are developed to evaluate the heat leakage due to the gasket and air infiltration in domestic refrigerators. In the first study, experimental and numerical approaches are applied to evaluate the gasket heat transfer based on the “Reverse Heat Load Method”. The main objective is to find the effective heat leakage with the dimensions of energy leakage per gasket length per temperature difference (W/m.K). An insulated cubic box with a …

Parking Lot Monitoring System Using An Autonomous Quadrotor Uav, Venkataraman Ganesh

All Theses

The main goal of this thesis is to develop a drone-based parking lot monitoring system using low-cost hardware and open-source software. Similar to wall-mounted surveillance cameras, a drone-based system can monitor parking lots without affecting the flow of traffic while also offering the mobility of patrol vehicles. The Parrot AR Drone 2.0 is the quadrotor drone used in this work due to its modularity and cost efficiency. Video and navigation data (including GPS) are communicated to a host computer using a Wi-Fi connection. The host computer analyzes navigation data using a custom flight control loop to determine control commands to …

Improving The Implementation Of Pavement Preservation Strategies In South Carolina, Franklin Reed

All Theses

With compounding budget constraints on infrastructure, cost effective solutions to maintain roadways are becoming increasingly important. Pavement preservation provides a cost effective option to keep the roadway network at an acceptable level. However, pavement preservation is a relatively new concept that many states have not fully implemented successfully. This research supports efforts to improve the pavement preservation practices in the state of South Carolina. It analyzes the current pavement preservation practices in South Carolina as well as other states to identify where improvements could be made. The research also outlines a treatment tracking program for the state of South Carolina …

Co-Design Of Dynamic Real-Time Scheduling And Cooperative Control For Human-Agent Collaboration Systems Based On Mutual Trust, Xiaotian Wang

All Theses

Mutual trust is a key factor in human-human collaboration. Inspired by this social interaction, we analyze human-agent mutual trust in the collaboration of one human and (semi)autonomous multi-agent systems. In the thesis, we derive time-series human-agent mutual trust models based on results from human factors engineering. To avoid both over- trust and under-trust, we set up dynamic timing models for the multi-agent scheduling problem and develop necessary and sufficient conditions to test the schedulability of the human multi-agent collaborative task. Furthermore, we extend the collaboration between one human and multiple agents into the collaboration between multi-human network and swarm-based agents …

A Robust Data Exchange Framework For Connected Vehicle Technology Supported Dynamic Transit Operations, Yucheng An

All Theses

Transit systems are an integral part of surface transportation systems. A connected vehicle technology (CVT) supported transit system will assist the users to manage trips both dynamically and efficiently. The primary focus of this research is to develop and evaluate the performance of a secure, scalable, and resilient data exchange framework. In the developed data exchange framework, a new data analytics layer, named Transit Cloud, is used to receive data from different sources, and send it to different users for a Dynamic Transit Operations (DTO) application. The DTO application allows the transit users to request trip information and obtain itineraries, …

Decellularized Bovine Nucleus Pulposus As A Biomimetic Scaffold For Intervertebral Disc Regeneration, Christopher Fernandez

All Theses

Low back pain (LBP) is a significant burden with a lifetime prevalence of 84% and estimated expenditures of $85.9 billion.[1,2] Although LBP is multifactorial; it has been shown that LBP can originate from degenerating intervertebral discs (IVDs); a process which initiates in the nucleus pulposus (NP); a hydrated tissue primarily composed of type 2 collagen and proteoglycan. Current therapies for IVD degeneration (IDD) are palliative and merely delay surgical management. While these procedures may relieve pain temporarily, they fail to address the underlying cause of degeneration and make no attempt to regenerate the effected tissue. Additional concerns with the use …

Electrical Characterization Of Gold And Platinum Thin Film Electrodes With Polyaniline Modified Surfaces, John Aggas

All Theses

Recent studies into soft organic electronics have burgeoned as a result of discoveries of conducting polymers such as polyaniline, polythiophene, and polypyrrole. However, in order to make these conducting polymers suitable for in vivo soft organic electronics, they must be developed so that they can be biocompatible and provide accurate sensing. Chitosan, a naturally occurring polymer structure found in exoskeletons of crustaceans, has been studied for its biocompatible properties. Composites of polyaniline (PAn), an intrinsically conductive polymer (ICP) and chitosan (Chi), a biopolymer, were developed and applied to gold and platinum Thin Film Electrode (TFE) devices. Electropolymerization and drop cast …

Phasor Measurement Unit Deployment Approach For Maximum Observability Considering Vulnerability Analysis, Jyoti Paudel

All Theses

In recent years, there has been growing interest of synchrophasor measurements like Phasor Measurement Units (PMUs) Power systems are now being gradually populated by PMU since they provide significant phasor information for the protection and control of power systems during normal and abnormal situations. There are several applications of PMUs, out of which state estimation is a widely used. To improve the robustness of state estimation, different approaches for placement of PMUs have been studied. This thesis introduces an approach for deployment the PMUs considering its vulnerability. Two different analysis have been considered to solve the problem of locating PMUs …

A Novel Approach To Evaluating Compact Finite Differences And Similar Tridiagonal Schemes On Gpu-Accelerated Clusters, Ashwin Trikuta Srinath

All Theses

Compact finite difference schemes are widely used in the direct numerical simulation of fluid flows for their ability to better resolve the small scales of turbulence. However, they can be expensive to evaluate and difficult to parallelize. In this work, we present an approach for the computation of compact finite differences and similar tridiagonal schemes on graphics processing units (GPUs). We present a variant of the cyclic reduction algorithm for solving the tridiagonal linear systems that arise in such numerical schemes. We study the impact of the matrix structure on the cyclic reduction algorithm and show that precomputing forward reduction …

Characterization Of A Multi-Laminate Angle-Ply Af Patch For Annulus Fibrosus Repair, Ryan Borem

All Theses

Annually, over 5.7 million Americans are diagnosed with two IVD-associated pathologies: IVD herniation (IVDH- a mechanical disruption of the concentric fibrous layers of the annulus fibrosus (AF))) and degeneration (IVDD- a multifactorial process which initiates within the inner gelatinous core (NP), and results in a biochemical degradation of NP tissue), with over 2.7 million requiring surgical inteventions.1,2 Although both underlying pathologies are different, quite often they both lead to a decrease in IVD height, impaired mechanical function, and increased pain and disability. These pain symptoms affect approximately 80% of the adult population during their lifetime with estimated expenditures exceeding $85.9 …

Analysis Of Citrate Content In Bone Using High Performance Liquid Chromatography, Matthew Konstantin Pysh

All Theses

Approximately 1.5 wt. % of bone is comprised of citrate molecules bound to the surface of apatite crystals. Furthermore, 80 to 90% of physiological citrate is contained within bone. Recently, interest in citrate has increased due to the potential of a citrate based method for estimation of postmortem intervals, time since death, of skeletal remains. The broad objective of this research was to develop and validate a High-Performance Liquid Chromatography (HPLC) method for quantitative and qualitative analysis of citrate in bone. An appropriate HPLC column and operating conditions for the detection of citrate were selected and subsequently used to analyze …

A Training Assistant Tool For The Automated Visual Inspection System, Mohan Karthik Ramaraj

All Theses

This thesis considers the problem of assisting a human user setting up an automated Visual Inspection (VI) system. The VI system uses a stationary camera on an automobile assembly line to inspect cars as they pass by. The inspection process is intended to identify when parts have been missed or incorrect parts have been assembled. The result is reported to a human working on the assembly line who then can take corrective actions. As originally developed, the system requires a setup phase in which the human user places the camera and records a video of at least 30 minutes length …

Operational Analysis Of Traditional Access Management Strategies & Demand-Responsive Access Control On Arterials, Joshua Mitchell

All Theses

Arterials are typically characterized by closely-spaced signalized intersections, high driveway density, and high traffic volumes. These characteristics contribute to congestion, as well as crashes. Access management strategies can address both operational and safety issues on urban arterials. This research focuses on the operational impacts of access management with two objectives: (1) quantify the impacts of ‘traditional’ access management strategies and (2) quantify the impacts of demand-responsive access control. To satisfy Objective 1, four traditional access management strategies were tested – (i) access spacing, (ii) corner clearance, (iii) access restriction, and (iv) raised median implementation. These were analyzed in four respective …

Analysis And Synthesis Of Effective Human-Robot Interaction At Varying Levels In Control Hierarchy, David Spencer

All Theses

Robot controller design is usually hierarchical with both high-level task and motion planning and low-level control law design. In the presented works, we investigate methods for low-level and high-level control designs to guarantee joint performance of human-robot interaction (HRI). In the first work, a low-level method using the switched linear quadratic regulator (SLQR), an optimal control policy based on a quadratic cost function, is used. By incorporating measures of robot performance and human workload, it can be determined when to utilize the human operator in a method that improves overall task performance while reducing operator workload. This method is demonstrated …

Design And Analysis Of Foundation For Onshore Tall Wind Turbines, Shweta Shrestha

All Theses

Wind turbines play a vital role in producing sustainable and clean energy to fulfill the growing energy needs. Energy generated from wind turbines being more sustainable and cost effective, many countries have taken a major step to develop wind turbines with large capacity. There has been a significant reduction in the levelized cost of energy (LCOE) since the 1980’s from the development of larger wind farms and from consistent performance improvements of wind turbine components. The power generation capacity of wind turbines has increased significantly over the years with the use of taller towers. When the tower height increases, the …