Digital Commons Network^™

Synthesis And Characterization Of Polymer Layers For Control Of Fluid Transport, Fehime Vatansever

All Dissertations

The level of wetting of fiber surface with liquids is an important characteristic of fibrous materials. It is related to fiber surface energy and the structure of the material. Surface energy can be changed by surface modification via the grafting methodologies that have been reported for introducing new and stable functionality to fibrous substrates without changing bulk properties.

Present work is dedicated to synthesis and characterization of macromolecular layers grafted to fiber surface in order to achieve directional liquid transport for the modified fabric. Modification technique used here is based on formation of stable polymer layer on fabric surface using …

Arachidonic Acid Reverses The Pyriproxyfen And Ibuprofen Induced Toxicity In Daphnia Magna, Gautam Kumar Ginjupalli

All Dissertations

Healthy reproduction and neonatal sex ratios of Daphnia are crucial to the health of the aquatic ecosystems in which Daphnia play principal roles in trophic transfer of nutrients. Combinations of environmental factors such as availability and quality of diet, overcrowding, hypoxia, reduced photoperiods and fall in ambient temperatures perturb normal parthenogeneic reproduction and induce sexual reproduction through male production. Male production provides a mechanism for overcoming specific stressors such as overcrowding and overwinter pond desiccation. However, it also induces a decrease in the Daphnia population that could have adverse implications on the pond ecosystem that depend on Daphnia . Interestingly, …

Ecology And Impacts Of Coyotes (Canis Latrans) In The Southeastern United States, Cady Etheredge

All Dissertations

Recent coyote (Canis latrans ) colonization of the southeastern United States has prompted speculation on the top-down effects of a new top predator on systems which have gone without a strong predator presence since the extirpation of the red wolf (Canis rufus ). This dissertation reports on the results of a series of investigations of the potential impact of coyotes on raccoons (Procyon lotor ) and other management issues related to coyotes in the Southeast. Chapters 1-3 present indirect field tests of the Mesopredator Release Hypothesis. Chapter 4 presents an overview of the current knowledge of the …

Encapsulated And Monolithic Resonant Structures For Laser Applications, Aaron Pung

All Dissertations

Typically, the composition of a laser system includes a gain medium, a pump illumination source, and an external feedback cavity. This cavity consists of a highly reflective mirror and an outcoupler component. The geometry of the outcoupler can be engineered to tailor the reflected or transmitted beam's spatial and spectral distribution. Functionally, the transmitted beam profile is dependent on the laser application. Broadband reflection profiles can be obtained by utilizing a distributed Bragg reflector (DBR). A DBR device consists of multiple layers of alternating materials. Constructive interference of the reflected light off each interface between different materials produces the spectrally …

Chemical Evolution Of The Neutron-Rich Iron-Group Isotopes And Implications For The Formation Of Fun Cais, Tianhong Yu

All Dissertations

Calcium-aluminum-rich inclusions (CAIs) are millimeter-sized refractory objects found in primitive meteorites. CAIs are considered as some of the first solids to form in the solar system, because they are refractory. FUN CAIs, those with Fractionated and Unknown Nuclear effects, are a small subset of CAIs. These FUN CAIs show correlated excesses and deficits in the neutron-rich iron-group isotopes such as ⁴⁸ Ca and ⁵⁰ Ti which regular CAIs do not. Interestingly, these isotopes are most likely produced infrequently but in huge quantities in a rare class of thermonuclear (Type Ia) supernovae. I propose that the isotopic effects in the neutron-rich …

Approximation In Multiobjective Optimization With Applications, Lakmali Weerasena

All Dissertations

Over the last couple of decades, the field of multiobjective optimization has received much attention in solving real-life optimization problems in science, engineering, economics and other fields where optimal decisions need to be made in the presence of trade-offs between two or more conflicting objective functions. The conflicting nature of objective functions implies a solution set for a multiobjective optimization problem. Obtaining this set is difficult for many reasons, and a variety of approaches for approximating it either partially or entirely have been proposed.

In response to the growing interest in approximation, this research investigates developing a theory and methodology …

Seismic Site Coefficient Model And Improved Design Response Spectra Based On Conditions In South Carolina, Shimelies Aboye

All Dissertations

A new seismic site coefficient model is developed from the results of over 60,000 total stress, one-dimensional equivalent ground response simulations assuming conditions in South Carolina. Computed site coefficients ( F ) are plotted versus average shear wave velocity in the top 30 m (V_S30 ) and grouped by location, spectral acceleration (S_outcrop ) and spectral period. Locations considered in the Coastal Plain include Aiken, Charleston, Columbia, Florence, Lake Marion, Myrtle Beach, and the South Carolina side of Savannah. Locations considered in the Piedmont include Columbia, Greenville, Greenwood, and Rock Hill. In all the plots of …

L1 Methods For Shrinkage And Correlation, Jie Shen

All Dissertations

This dissertation explored the idea of L1 norm in solving two statistical problems including multiple linear regression and diagnostic checking in time series. In recent years L1 shrinkage methods have become popular in linear regression as they can achieve simultaneous variable selection and parameter estimation. Their objective functions containing a least squares term and an L1 penalty term which can produce sparse solutions (Fan and Li, 2001). Least absolute shrinkage and selection operator (Lasso) was the first L1 penalized method proposed and has been widely used in practice. But the Lasso estimator has noticeable bias and is inconsistent for variable …

Genetic Algorithm Techniques In Climate Changepoint Problems, Shanghong Li

All Dissertations

The first part of this dissertation studies genetic algorithms as a means of estimating the number of changepoints and their locations in a climatic time series. Such methods bypass classical subsegmentation algorithms, which sometimes yield suboptimal conclusions. Minimum description length techniques are introduced. These techniques require optimizing an objective function over all possible changepoint numbers and location times. Our general objective functions allow for correlated data, reference station aspects, and/or non-normal marginal distributions, all common features of climate time series. As an exhaustive evaluation of all changepoint configurations is not possible, the optimization is accomplished via a genetic algorithm that …

Factors Affecting The Surface-Mediated Reduction Of Plutonium In The Presence Of Pure Mineral Phases, Amy Hixon

All Dissertations

The overall objective of the research is to investigate the mechanistic and kinetic aspects of the surface-mediated reduction of plutonium. The first chapter is a critical review of plutonium sorption to pure mineral phases. The objective is to study if and how the mechanisms by which plutonium interacts with mineral surfaces are connected to mechanisms for the surface-mediated reduction of plutonium. The main conclusion of the review is that advanced spectroscopy, microscopy, and molecular modeling are needed to fully understand not only the surface structure of pure mineral phases, but also the coordination and bonding environment of plutonium surface complexes. …

Hybrid Low-Order Modeling For Conceptual Vehicle Design, Robert Mau

All Dissertations

Design freedom, and particularly the freedom to incorporate innovative designs and strategies, is greatest at the very beginning of vehicle conceptual design. Conversely, this is when the least knowledge of the product exists. As product content decisions are made the level of freedom in the design decreases and the design becomes "locked in." The majority of vehicle lifecycle cost is also set by the end of vehicle conceptual design. This makes it critical to make well-informed and validated decisions in the concept design phase to avoid expensive iterations and redesign in the detailed design phase. Parametric vehicle modeling permits rapid …

A Phenomenological Study Of College Seniors In A Performing Arts Music Program, Eric Lapin

All Dissertations

Music has been an integral component of higher education dating back to the Middle Ages. As higher education developed in American institutions a traditional degree program began to emerge. Students in American higher education music programs focused on either performance or music education. However, a review of the literature has shown that these traditional programs are rife with limitations, and in many cases are not properly preparing students. As a result, Performing Arts style undergraduate degree programs are gaining popularity. These Performing Arts programs seek to offer a more comprehensive music and arts experience that more adequately prepares graduates for …

The Detection Of A Light Echo From Sn 2007af, Dina Drozdov

All Theses

Type Ia supernovae are widely studied for their uniform properties, which make them ideal candidates for cosmological surveys. Although these exploding stars are popular targets, key funda-mental questions about their nature remain, and new techniques need to be developed to investigate the progenitor system and explosion mechanisms. Light echoes are created by light scattering off dust that reaches the observer after the direct path light from the explosion arrived and have been studied for the past 100 years. Light echoes from Type Ia supernovae are rare, with only a few cases being discovered in the past decades. Because light echoes …

Characterization Of The Hydrogeology And Stress State In The Vicinity Of The Homestake Mine, Lead, Sd, Johnathan Ebenhack

All Theses

Underground workings in fractured rock are common worldwide. They have applications in numerous areas and fields of study. These include mining operations, civil engineering projects like tunnels and underground facilities, and research projects that require underground laboratories such as the physics research being conducted by Sanford Laboratory at the former Homestake mine and Fermi Laboratory near Chicago (Bahcall et al. 2001, Elsworth 2009, Sadoulet et al. 2006, bge science@DUSEL, fnal.gov). These excavations can reach several kilometers in depth including the 3.9 km deep TauTona mine in South Africa, the 3 km deep LaRonde mine in Quebec and the 2.4 km …

Room Generation, Removal, And Recovery In Udk 3.5, Scott Johnson

All Theses

This paper explores algorithms and techniques for creating an extended game world that represents a radical departure from the widely used static content in current use with most games featuring procedurally generated game worlds. Using the Unreal Development Kit 3.5 game engine and focusing on a small set of rooms and doors the research sets to create a game world that is in constant flux and addresses issues of game development limitations on the size of game worlds.

Lithostratigraphic And Petrophysical Analysis Of The Middle Devonian Marcellus Shale At The Mamont Prospect, Westmoreland County, Pennsylvania, Ty Taylor

All Theses

The organic-rich Middle Devonian Marcellus Shale of the Appalachian basin is a rapidly developing natural gas play. Stratigraphic boundaries of the Marcellus Shale in Westmoreland County, Pennsylvania were identified using geophysical logs from 10 vertical gas-producing wells in a 23 sq. km area. Gamma-ray, bulk density, and resistivity well logs were examined to assess hydrocarbon potential. Values of porosity, total organic carbon (TOC), and water saturation (SW) were derived and mapped by incorporating well-log data into Marcellus-specific formulas. Gamma-ray, penetration (minutes per foot drilled), and mud-logging gas (total gas) from 12 horizontal wells from within the study area were also …

Sociallink: A Social Network Based Trust System For P2p File Sharing Systems, Fang Qi

All Theses

In peer-to-peer (P2P) file sharing systems, many autonomous peers without preexisting trust relationships share files with each other. Due to their open environment and distributed structure, these systems are vulnerable to the significant impact from selfish and misbehaving nodes. Free-riding, whitewash, collusion and Sybil attacks are common and serious threats, which severely harm non-malicious users and degrade the system performance. Many trust systems were proposed for P2P file sharing systems to encourage cooperative behaviors and punish non-cooperative behaviors. However, querying reputation values usually generates latency and overhead for every user. To address this problem, a social network based trust system …

Cultural Convergences, David Armistead

All Theses

As far back as I can remember my family has had two primary outlets in regards to entertainment; going to museum exhibitions and attending or watching football games. My parents have been members of the High Museum in Atlanta for years while simultaneously having season tickets to Georgia Tech football. My current series of paintings, drawings, prints and videos examine the cultural significance of sports in American society; specifically American football. As a "big guy" who was raised in the south, it is often assumed that I played football at some point in my life. Admittedly, I feed this stereotype …

Sequential Autotrophic-Heterotrophic Culture Of Scenedesmus Spp. For Lipid Production, Jazmine Taylor

All Theses

Algae are fascinating organisms that are receiving growing attention for their versatility on many fronts of research areas. Immense amounts of research is being conducted to find solutions to challenges in energy and climate change. A large portion of research is focused on algae as a potential solution to both of these issues. The focus of this research is to look at algae closer to home as a local, economical resource to aid in solving both of these problems. The algal genus Scenedesmus was tested for growth in a bi-phased scheme: photoautotrophically for carbon sequestration then heterotrophically on glycerol for …

Development And Verification Of A Test System To Quantify Strain Of An Optical Displacement Indicator And The Design Of A Strain Indicating Prototype, Josh Lake

All Theses

The organic-rich Middle Devonian Marcellus Shale of the Appalachian basin is a rapidly developing natural gas play. Stratigraphic boundaries of the Marcellus Shale in Westmoreland County, Pennsylvania were identified using geophysical logs from 10 vertical gas-producing wells in a 23 sq. km area. Gamma-ray, bulk density, and resistivity well logs were examined to assess hydrocarbon potential. Values of porosity, total organic carbon (TOC), and water saturation (SW) were derived and mapped by incorporating well-log data into Marcellus-specific formulas. Gamma-ray, penetration (minutes per foot drilled), and mud-logging gas (total gas) from 12 horizontal wells from within the study area were also …

Phonon Transport Analysis Of Semiconductor Nanocomposites Using Monte Carlo Simulations, Mayank Malladi

All Theses

Nanocomposites are composite materials which incorporate nanosized particles, platelets or fibers. The addition of nanosized phases into the bulk matrix can lead to significantly different material properties compared to their macrocomposite counterparts. For nanocomposites, thermal conductivity is one of the most important physical properties. Manipulation and control of thermal conductivity in nanocomposites have impacted a variety of applications. In particular, it has been shown that the phonon thermal conductivity can be reduced significantly in nanocomposites due to the increase in phonon interface scattering while the electrical conductivity can be maintained. This extraordinary property of nanocomposites has been used to enhance …

Macroscopic Investigation Of Ionic- And Nano-Silver Toxicity To Soil Nitrification Process, Abdurrahman Masrahi

All Theses

The worldwide production of engineered nanoparticles (ENPs) has grown rapidly in our era because of the popular applications in industrial and consumer markets. Especially silver (Ag) NP is one of mostly common ENPs in our consumer products due to its unique antimicrobial property. However, release of AgNPs into environment through wastewater treatment plants poses a question that what impact AgNPs have on microbially mediated processes in environment (e.g., nutrient and trace element cycles). In the last decades, numerous toxicological studies of AgNPs on bacteria have been conducted in pure culture systems, and several different antimicrobial mechanisms of AgNPs have been …

Evaluating The Predictive Capability Of Numerical Models Considering Robustness To Non-Probabilistic Uncertianty In The Input Parameters, Parker Shields

All Theses

The paradigm of model evaluation is challenged by compensations between various forms of errors and uncertainties that are inherent to the model development process due to, for instance, imprecise model input parameters, scarcity of experimental data and lack of knowledge regarding an accurate mathematical representation of the system. When calibrating model input parameters based on fidelity to experiments, such compensations lead to non-unique solutions. In turn, the existence of non-unique solutions makes the selection and use of one `best' numerical model risky. Therefore, it becomes necessary to evaluate model performance based not only on the fidelity of the predictions to …

Virtualizing Intelligent River®: A Comparative Study Of Alternative Virtualization Technologies, Aravindh Sampathkumar

All Theses

Emerging cloud computing infrastructure models facilitate a modern and efficient way of utilizing computing resources, enabling applications to scale with varying demands over time. The core enabler of the cloud computing paradigm is virtualization. The concept is not new; virtualization has garnered significant research attention, fostering a race to achieve the lowest possible virtualization overhead. The evolution has led to three primary virtualization approaches: full-virtualization, para-virtualization, and container-based virtualization, each with a unique set of strengths and weaknesses. Thus it becomes important to study and evaluate their quantitative and qualitative differences. The operational requirements of the Intelligent River® middleware system …

Speech Enhancement By Exploiting The Baseband Phase Structure Of Voiced Speech For Effective Non-Stationary Noise Estimation, Sanjay Patil

All Theses

Speech enhancement is one of the most important and challenging issues in the speech communication and signal processing field. It aims to minimize the effect of additive noise on the quality and intelligibility of the speech signal. Speech quality is the measure of noise remaining after the processing on the speech signal and of how pleasant the resulting speech sounds, while intelligibility refers to the accuracy of understanding speech. Speech enhancement algorithms are designed to remove the additive noise with minimum speech distortion.The task of speech enhancement is challenging due to lack of knowledge about the corrupting noise. Hence, the …

Aqueous Geochemistry Of Rhenium And Chromium In Saltstone: Implications For Understanding Technetium Mobility In Saltstone, Amanda Hatfield

All Theses

Incorporation of low level radioactive waste in cementitious materials is an important waste disposal technology in practice at a U.S. DOE facility, the Savannah River Site (SRS), Aiken, SC. One of the major risk drivers, technetium (99Tc)

Stimulated Raman Scattering In Micro Sphere Resonators, Ruoyu Zhang

All Theses

Micro sphere resonators that hold optical whisper gallery modes (WGMs) provide an innovative option for implementing micro optical resonators. The unique properties of the micro sphere resonator make it capable to introduce resonance for various optical phenomenon, like stimulated Raman scattering (SRS), in micron scale.

This thesis illustrates the characteristics of micro sphere resonators and demonstrates the resonance-enhanced SRS in micro sphere resonators with reduce threshold power. Both theoretical and experimental results are presented. Coupling model for WGM is derived in transfer matrix method. Simulation analyses for mode pattern of WGMs are solved based on mathematic model and finite element …

The Fabrication And Study Of Silver Nanoparticle Structures, Aubrie Pfirman

All Theses

Nanotechnology and the synthesis of nanoparticle systems are attractive in part because of interesting, tunable optical and electrical properties that are not observed with bulk material. Silver nanoparticles (Ag NPs) interact with visible light more efficiently than any other system due to the excitation of plasmon resonances, which are the collective oscillations of the free electron density. These collective oscillations produce an enhanced local electromagnetic (EM) field: this field is responsible for highly-utilized phenomena such as surface enhanced Raman scattering (SERS), enhanced fluorescence, surface enhanced infrared absorption (SEIRA), and many others. Many experiments have been conducted to optimize and tailor …

Creating Tradition: Change Ringing And The Myth Of The 'Holy City', Charlotte Hewitt Causey

All Theses

This thesis analyzes the recent creation of tradition surrounding church bells and bell towers in Charleston, South Carolina. Church bells have been a significant feature of Charleston’s aural landscape since the mid-eighteenth century when St. Michael’s hung a ring of bells in the tower that still dominates the intersection of Meeting and Broad Streets. The histories of four churches, St. Michael’s (1751), the Cathedral of St. Luke and St. Paul (1811), St, Matthew’s Lutheran (1867), and Grace Episcopal (1846) affirms the important role that bells played for these congregations. The bells installed in these churches and the uses to which …

Evaporation And Modeling Water Availability In The Savannah River Basin, Ryne Phillips

All Theses

Four methods for estimating lake evaporation are presented and compared. Three are mass transfer methods that incorporated high resolution satellite imagery obtained from the MODIS sensor on the Terra and Aqua satellites. The fourth is the traditional pan method, which used monthly derived pan coefficients and pan evaporation measurements from a Class A evaporation pan located in Clemson, SC.

The four evaporation methods were used to estimate lake evaporation from the five major lakes in the Savannah River Basin for a period of more than one decade. Analysis of the evaporation rates clearly illustrated the uncertainty in daily, monthly, and …