Engineering Commons^™

Stochastic Wavenumber Estimation: Damage Detection Through Simulated Guide Lamb Waves, Garrison Stevens

All Theses

Structural Health Monitoring (SHM) is a field of research that seeks to identify the onset of damage in infrastructure systems such that catastrophic failures can be averted. Acoustic Wavenumber Spectroscopy (AWS) is an emerging SHM technique that can identify and locate change of thickness resulting from damage in thin plates through the estimation of the characteristic wavenumber. AWS measures the ultrasonically induced vibrations of thin plates by laser scanners and monitors the propagation of Rayleigh-Lamb waves through the structure. This method is particularly suitable for thin-walled structures such as those contained in pipes, airplanes, and wind turbine blades. While AWS …

Fabrication And Characterization Of Magnetic Nanoparticle Composite Membranes, Akeem Cruickshank

All Theses

To effectively and accurately deliver drugs within the human body, both new designs and components for implantable micropumps are being studied. Designs must ensure high biocompatibility, drug compatibility, accuracy and small power consumption. The focus of this thesis was to fabricate a prototype magnetic nanoparticle membrane for eventual incorporation into a biomedical pump and then determine the relationship between this membrane deflection and applied pneumatic or magnetic force. The magnetic nanoparticle polymer composite (MNPC) membranes in this study were composed of crosslinked polydimethylsiloxane (PDMS) and iron oxide nanoparticles (IONPs). An optimal iron oxide fabrication route was identified and particle size …

A Device To Record Naturally Daily Wrist Motion, Surya Sharma

All Theses

We introduce a new device to record and store wrist motion activity data. The motivation to create this device was the fact that this data can be used to detect periods of eating or the number of bites consumed. There is no similar device available in the market. This device uses new components that have been recently introduced to the market, and newer techniques that can be used for low quantity production. The production cost for this device was $52, similar to other fitness trackers on the market. The device was capable of recording wrist motion activity for 24 hours …

Geotechnical Analysis Of The Foundation Of Fort Sumter National Monument Using Numerical Modeling, Daniel Kyser

All Theses

The foundational condition of the historical coastal fortification of Fort Sumter in Charleston, SC was analyzed though the use of numerical modeling. In this study, two-dimensional Finite Element (FE) analyses were conducted to assess the stability of the foundation-casemates-wall system in a coupled manner subjected to potential loadings such as ocean waves, storm surge and earthquake. The finite element model was verified by modeling the historical events (construction between 1820 and 1860, demolition due to artillery bombardment, reconstruction, earthquake, building of the Battery Huger, and the removal of fill from the parade ground) since the construction of the fort in …

Characterizing Navigational Tools In A Virtual Search Task, Austin Riggs

All Theses

The goal of this thesis is to characterize and empirically compare navigational tools in the context of a virtual inspection task. The framework considers both directional-cue navigational tools (e.g., GPS navigation arrows) and trail navigational tools (e.g.,footprints) in comparison to a control condition. Characterizing the tools allows for documented relationships between specific navigational tool-performance combinations. It is intended that by characterizing and comparing the tools a more advantageous use of navigational tools will emerge to increase the benefit provided to both the users and implementers of virtual environments. The focus of the metrics in the paper were distance traveled, speed …

Combined Numberical And Experimental Assessment Of Steel Roof Decks Subjected To Windborne Debris, Robert Roper

All Theses

In the summer of 2013, a steel roof deck manufacturer (Company A) approached Clemson University about testing their steel roof decking product to evaluate the performance of the steel roof deck to resist impact from tornado windborne debris using FEMA P-361 Design and Construction Guidance for Community Safe Rooms. To assist Company A in better serving their customers in areas prone to severe wind events and to facilitate use of their products in community safe rooms, debris impact tests were conducted on two cold-formed corrugated steel roof decking products. Community safe rooms are buildings that are constructed in accordance with …

A Model Of The Diurnal Variation In Lake Surface Temperature, Jonathan L. Hodges

All Theses

Satellite measurements of water surface temperature can benefit several environmental ap-plications such as predictions of lake evaporation, meteorological forecasts, and predictions of lake overturning events, among others. However, limitations on the temporal resolution of satellite mea-surements restrict these improvements. A model of the diurnal variation in lake surface temperature could potentially increase the effective temporal resolution of satellite measurements of surface tem-perature, thereby enhancing the utility of these measurements in the above applications. Herein, a one-dimensional transient thermal model of a lake is used in combination with surface tempera-ture measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the …

Steps Toward A Net-Zero Campus With Renewable Energy Resources, Andrew Clarke

All Dissertations

With the increasing attention and support behind plug in hybrid electric vehicles, research must be conducted to examine the impacts of vehicles on electric distribution and transmission systems. This research aims first to model the behavior of vehicle battery chargers during system disturbances and mitigate any impacts. A distribution test system example is modeled and several different vehicle charger topologies are added. Faults are applied to the distribution system with vehicle chargers connected and the results are examined. Based on these results, a control strategy to mitigate their negative impacts is suggested. Photovoltaic panels are then added to the system …

Experimental Evidence For Colloid-Facilitated Transport Of Plutonium, Hilary Emerson

All Dissertations

Colloid-facilitated transport of the actinides has been observed previously in the field on the kilometer scale. The objective of this work is to investigate the mechanisms of colloid-facilitated transport with controlled settings and conditions. The experimental work in this dissertation investigates transport of a ternary complex with iron oxide colloids, organic ligands and actinides in the presence of quartz or a natural sandy soil as well as simplified systems building up to the ternary complexes. The first three papers investigate the following: (1) unsaturated transport of iron oxide colloids in a natural sandy soil lysimeter with and without natural organic …

Effects Of Transportation Hazards On Package Performance And Food Product Shelf Life, Kyle Dunno

All Dissertations

This research studied the effect of transportation hazards on food product shelf life and package performance. Studies were conducted to determine the effect of package headspace volume, product viscosity and storage temperature on package integrity. Finally, accelerated shelf life testing (ASLT) was utilized to determine how simulated transportation hazards affected the shelf life of a specific food product. Institutional retort pouches containing either water or 5% starch solution were filled with varying amounts of headspace volume to determine if package headspace volume could aid in package performance during simulated engineering tests for packaged products. Fixed displacement vibration testing and compression …

Toward Understanding The Thermodynamics And Mechanisms Of Actinide Sorption Reactions, Shanna Estes

All Dissertations

The environmental fate of actinides is greatly influenced by interfacial reactions, including sorption onto solid surfaces. Because changes in the primary hydration sphere of the actinide are expected to greatly influence the thermodynamics (i.e., reaction enthalpy and entropy) of these reactions, examining actinide sorption thermodynamics may provide insight into actinide sorption mechanisms. Additionally, examining actinide sorption thermodynamics may enhance the ability to model or predict these reactions in environmental or engineered systems where variable or elevated temperatures are expected. However, few researchers have studied actinide sorption thermodynamics. Therefore, this research examined the thermodynamics of Eu(III) (a trivalent actinide analog), Th(IV), …

Investigation Of Subgrid-Scale Mixing In Turbulent Plane Jets And Turbulent Jet Flames, Shuaishuai Liu

All Dissertations

The subgrid-scale (SGS) mixing of mixture fraction, temperature, and species mass fraction in turbulent partially premixed (Sandia) flames is studied. We focus on the effects of the SGS mixing regimes and the spatial relationships among the scalars on the SGS mixing of the species mass fractions. High resolution lines images are used to obtain the scalar filtered mass density function and the conditionally filtered diffusion. The results show that for small SGS variance the scalar fields have a relatively simple structure. For large SGS variance the structure is more complex. The spatial relationships among the scalars result in different SGS …

Nonequilibrium Transport Of Ionic Liquids In Electrified Nanosystems, Xikai Jiang

All Dissertations

Room-temperature ionic liquids (RTILs) are a promising class of electrolyte that are composed entirely of ions but are liquid at room temperature. Their remarkable properties such as wide electrochemical window make them ideal electrolytes in many electrochemical systems. Because the non-equilibrium transport of RTILs often determines the performance of these systems, a fundamental understanding of such transport is needed. Here, using molecular dynamic (MD) and continuum simulations, we investigated the non-equilibrium transport of RTILs in three scenarios relevant to the application of RTILs in electrochemical systems: the electroosmotic flow (EOF) of RTILs through nanochannels, the electrokinetic transport of RTILs through …

Synthesis And Characterization Of Chemically Functionalized Shape Memory Nanofoams For Unattended Sensing Applications, Anna Paola Soliani

All Dissertations

The work in this dissertation is devoted to the synthesis and characterization of novel materials for off-line unattended sensing: shape-memory grafted nanofoams. The fabrication process and characterization of highly efficient, polymeric nanosensor element with the ability to selectively detect analytes and retain memory of specific exposure events is reported. These shape memory nanofoams could potentially act as efficient and highly sensitive coatings for evanescent waveguide-based optical monitoring systems. On exposure to specific analytes, the polymeric coatings locally change their internal structure irreversibly at the nanolevel, affecting the local optical properties such as refractive index. Currently, enrichment polymer layers (EPLs) are …

Autonomous Control And Automotive Simulator Based Driver Training Methodologies For Vehicle Run-Off-Road And Recovery Events, Paul Freeman

All Dissertations

Traffic fatalities and injuries continue to demand the attention of researchers and governments across the world as they remain significant factors in public health and safety. Enhanced legislature along with vehicle and roadway technology has helped to reduce the impact of traffic crashes in many scenarios. However, one specifically troublesome area of traffic safety, which persists, is run-off-road (ROR) where a vehicle's wheels leave the paved portion of the roadway and begin traveling on the shoulder or side of the road. Large percentages of fatal and injury traffic crashes are attributable to ROR. One of the most critical reasons why …

Particle Scavenging By Water Drops In An Ultrasonic Standing Wave Field, Weiyu Ran

All Dissertations

Currently the backbone of the world's energy supply is composed of fossil fuels. However, the combustion of fossil fuels results in the production of enormous quantities of particulate pollutants. The smog resulting from these particulate pollutants causes significant health problem for city dwellers. Wet scrubbers, which use a water spray to scavenge airborne particles, is one of the most widely used devices to control particulate pollutants. Typical wet scrubbers can scavenge particles with diameters bigger than 10 um, but it is inefficient in scavenging particles with diameters on the order of 1 um. Unfortunately these fine particles are more dangerous …

Studies Of Imbalance Difference Theory In Modeling Conversion Between Differential Mode And Common Mode Signals, Li Niu

All Dissertations

This dissertation describes three related studies regarding the imbalance difference theory in modeling the conversion between differential mode and common mode/antenna mode signals. The topics covered are: rigorous derivation of imbalance difference theory for modeling radiated emission problems, modeling the conversion between differential mode and common mode propagation in transmission lines, and modeling the loading impedance on differential mode signals due to radiated emissions. The imbalance difference theory describes a method for calculating the coupling between differential mode signals and common mode signals due to changes in electrical balance on a transmission line. It provides both physical insight and a …

High Frequency Devices And Circuit Modules For Biochemical Microsystems, Jiwei Sun

All Dissertations

This dissertation investigates high frequency devices and circuit modules for biochemical microsystems. These modules are designed towards replacing external bulky laboratory instruments and integrating with biochemical microsystems to generate and analyze signals in frequency and time domain. The first is a charge pump circuit with modified triple well diodes, which is used as an on-chip power supply. The second is an on-chip pulse generation circuit to generate high voltage short pulses. It includes a pulse-forming-line (PFL) based pulse generation circuit, a Marx generator and a Blumlein generator. The third is a six-port circuit based on four quadrature hybrids with 2.0~6.0 …

A Comprehensive Assessment Methodology Based On Life Cycle Analysis For On-Board Photovoltaic Solar Modules In Vehicles, Mahmoud Abdelhamid

All Dissertations

This dissertation presents a novel comprehensive assessment methodology for using on-board photovoltaic (PV) solar technologies in vehicle applications. A well-to-wheels life cycle analysis based on a unique energy, greenhouse gas (GHG) emission, and economic perspective is carried out in the context of meeting corporate average fuel economy (CAFE) standards through 2025 along with providing an alternative energy path for the purpose of sustainable transportation. The study includes 14 different vehicles, 3 different travel patterns, in 12 U.S. states and 16 nations using 19 different cost analysis scenarios for determining the challenges and benefits of using on-board photovoltaic (PV) solar technologies …

The Development And Characterization Of Tannic Acid Cross-Linked Collagen Scaffolds For The Prevention Of Breast Cancer Recurrence In Lumpectomy Patients, Beau Inskeep

All Dissertations

Breast cancer is the second most common cancer amongst women, second only to lung cancer. In 2014, it was estimated that there were approximately 295,000 new cases of breast cancer diagnosed in women, with approximately 40,000 deaths caused by breast cancer in the United States. It has been reported that a woman has a 12% chance of developing breast cancer in her lifetime and a 3% chance of dying from breast cancer. There are several treatment options available for breast cancer, including chemotherapy, radiation therapy, as well as two different forms of surgery, mastectomy and lumpectomy. However, none of these …

Thermally Responsive Polymer Electrolytes For Inherently Safe Electrochemical Energy Storage, Jesse Kelly

All Dissertations

Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in …

Development Of An In Vitro Three-Dimensional Breast Tissue Model To Decipher The Effects Of Stromal Heterogeneity On Normal And Cancerous Mammary Epithelial Cells, Erin Mccave

All Dissertations

A goal of breast cancer research is to develop a detailed understanding of the underlying mechanisms of disease progression and to generate approaches to improve early detection, monitoring, and treatment of breast cancerous lesions. Current breast cancer therapies are not successful for all cases as they were developed as a standard of care for 'average' breast cancer condition. To further current clinical success, the characteristics of each tumor mass must be considered. Such an individualized or personalized approach is incompatible with current understanding of 'average' breast cancer tumors and responses to treatments. The long-term objective of the present research is …

Thermo-Mechanical Characterization Of Glass And Its Effect On Predictions Of Stress State, Birefringence And Fracture In Precision Glass Molded Lenses, Dhananjay Joshi

All Dissertations

The Precision Glass Molding (PGM) process was established as an economical and sustainable option for the production of aspherical glass optics to satisfy the increased industrial demand. Applications of precision molded aspherical lenses range from consumer electronics products such as cell phone cameras to defense and medical systems. An aspherical lens can eliminate the spherical and optical aberrations as compared to a spherical lens thus making the lens system more compact and lighter. In spite of being a clean and environmentally friendly process, the lens molding operation suffers from a few drawbacks such as lens profile deviation, stress birefringence/refractive index …

Modeling Sustainability In Renewable Energy Supply Chain Systems, Fei Xie

All Dissertations

This dissertation aims at modeling sustainability of renewable fuel supply chain systems against emerging challenges. In particular, the dissertation focuses on the biofuel supply chain system design, and manages to develop advanced modeling framework and corresponding solution methods in tackling challenges in sustaining biofuel supply chain systems. These challenges include: (1) to integrate 'environmental thinking' into the long-term biofuel supply chain planning; (2) to adopt multimodal transportation to mitigate seasonality in biofuel supply chain operations; (3) to provide strategies in hedging against uncertainty from conversion technology; and (4) to develop methodologies in long-term sequential planning of the biofuel supply chain …

The Effects Of Secondary Trapping Mechanisms On Geologic Storage Of Carbon Dioxide, Catherine Ruprecht

All Dissertations

The goal of this Dissertation is to further the understanding of secondary trapping mechanisms in geologic CO₂ storage systems to improve storage design and security. This Dissertation takes the form of three chapters. The objective of the first chapter was to analyze the storage performance of supercritical and brine saturated CO₂ injection strategies to determine their advantages and disadvantages on distribution and immobilization of CO₂ and pressure buildup. Results showed dissolved CO₂ injection was favorable in terms of storage security in all cases as it resulted in smaller areal extents on the caprock and did not …

Earth Abundant Thin Film Technology For Next Generation Photovoltaic Modules, Githin Alapatt

All Dissertations

With a cumulative generation capacity of over 100 GW, Photovoltaics (PV) technology is uniquely poised to become increasingly popular in the coming decades. Although, several breakthroughs have propelled PV technology, it accounts for only less than 1% of the energy produced worldwide. This aspect of the PV technology is primarily due to the somewhat high cost per watt, which is dependent on the efficiency of the PV cells as well as the cost of manufacturing and installing them. Currently, the efficiency of the PV conversion process is limited to about 25% for commercial terrestrial cells; improving this efficiency can increase …

Composite Films With Magnetic Nanorods: Fundamentals, Processing And Applications, Yu Gu

All Dissertations

This Dissertation is centered on studying the composite films with magnetic nanorods. In recent years, one-dimensional magnetic nanostructures, such as magnetic nanorods, chains of magnetic nanoparticles, and nanotubes filled with magnetic nanoparticles have caught great attentions due to the breadth of applications. Their unique magnetic and geometrical features open new avenues of studies in medicine, sensors, optofluidics, magnetic swimming, and microrheology. In particular, they offered great opportunities for design of multifunctional devices and for manufacturing of anisotropic nano- and microstructures with unprecedented magnetic and mechanical properties. However, the strategy for nanorod alignment in both Newtonian and complex fluids has not …

Development Of A Transport System For Advancing Tissue Engineering And Cell Identification, Suzanne Mae Tabbaa

All Dissertations

This work centers on the development of a novel passive transport system for two tissue engineering applications – cell distribution and cell separation. This approach relies on a wicking fiber-based system, derived from the textile field that functions by directing and maintaining transport of cells as well as fluids and biomolecules. This system has the ability to enhance cell movement for both the purpose of cell seeding distribution as well as to isolate specific cell types from heterogeneous cell populations.

The success of spinal fusions and large bone defects is often limited by the decreased surrounding vasculature and the ability …

Coagulation-Ceramic Membrane Filtrati On For U.S. Surface Water Treatment Summary, Tanju Karanfil, Amir Y. Alansari, James E. Amburgey, Meric Selbes, Jaehong Kim, Seungjin Lee, Yonggyun Park

Publications

The objective of this project was to conduct a systematic pilot-scale investigation of a hybrid coagulation-ceramic membrane treatment system to gain fundamental insights about necessary pretreatment conditions, fouling mechanisms, and contaminant removal capabilities, using two U.S. surface water sources. A two-phase plan was implemented for each of the three coagulants considered in this study: aluminum sulfate, aluminum chlorohydrate, and ferric chloride. The first phase involved the optimization of the coagulation pretreatment conditions that provided the best performance in terms of particle removal, organics removal, and membrane fouling. The second phase involved a comprehensive performance evaluation of the optimized system. The …

Improving Tennis Player Performance Using System Development Interpretations Methodology, Dotan Shvorin, Kevin Taaffe

Publications

This research demonstrates a unique analytical approach to improving a player's performance in the game of tennis. We introduce a system development interpretations (SDI) methodology for associating player characteristics and factors in a hierarchical structure. We then show how this tool is applied in a human performance environment such as tennis. This approach was developed as a multi-disciplinary quality tool for process improvement that identifies factor dependencies and depicts their impact on the resulting player performance. From the implementation of the SDI methodology, the research was able to define the tennis player's difficulties and it has allowed the researchers to …