Physical Sciences and Mathematics Commons^™

Laboratory Studies In Chemically Mediated Phosphorus Removal, Rebecca L. Gilmore

Theses and Dissertations (Comprehensive)

Chemically mediated phosphorus removal, done during wastewater treatment, is an effective means of reducing nutrient loads to sensitive environments. Although this method of treatment is widely used, the mechanism of removal is poorly understood. Moreover, phosphorus regulations for wastewater effluents are moving to concentration ranges of 10-100 μg P/L (total phosphorus). This is much lower than current regulations (∼0.1 ∼0.2 mg P/L as TP) required by municipalities (Takács et al., 2006a; Murthy et al., 2005). The analytical methods for low level phosphate analysis need to be optimized to perform reliably and accurately at these low levels. To accomplish this, absorbance …

First-Passage Time Models With A Stochastic Time Change In Credit Risk, Hui Li

Theses and Dissertations (Comprehensive)

Many authors have used a time-changed Brownian motion as a model of log-stock returns. Using a Levy process as a stochastic time change, one obtains well known asset price models such as the variance gamma (VG) and normal inverse Gaussian (NIG) models. Following on the heels of these asset price models, it is natural to extend structural credit models by using a time-changed geometric Brownian motion and other jump-diffusion processes to model the value of a firm. To avoid the difficulties that arise in computing the associated first passage time distribution and in analogy to the time-changed Markov chain models, …

Mathematical Modeling Of Quantum Dots With Generalized Envelope Functions Approximations And Coupled Partial Differential Equations, Dmytro Sytnyk

Theses and Dissertations (Comprehensive)

No abstract provided.

Vibrational Spectroscopy Of Isotopically Labeled Indoles And Electron Transfer Involving Indole (Tryptophan) Radicals, Senghane Dominique Dieng

Theses, Dissertations and Culminating Projects

Vibrational spectroscopy of tryptophan can be used as a probe for local protein conformation and to study protein electron transfer. For the interpretation of the vibrational spectra, the proper assignment of the vibrational bands to normal modes is essential. We report the experimentally measured infrared and Raman spectra of tryptophan, indole and 3-methylindole as well as of several of their isotope substituted forms; tryptophan indole-d₅ and -¹⁵N₂, and indole 2-¹³C. The effect of the exchange of the indole NH to ND on the vibrational spectra of these molecules was also determined. The measurements …

Oxidative Stress, Calcium Homeostasis, And Altered Gene Expression In Human Lung Epithelial Cells Exposed To Zno Nanoparticles, Chuan-Chin Huang

Masters Theses

"The influence of 20 nm ZnO nanoparticles on oxidative stress, intracellular calcium homeostasis, and gene expression was studied in human bronchial epithelial cells (BEAS-2B). ZnO caused a concentration- and time-dependent cytotoxicity while elevating oxidative stress and causing membrane damage (cellular LDH release). There was a remarkably steep relationship between concentration and toxicity at concentrations from 5 to 10 μg/ml. Exposure to ZnO increased intracellular calcium levels in a concentration- and time-dependent manner. Treatment with the antioxidant N-acetylcysteine prevented cell loss and diminished the increase in intracellular calcium concentration, suggesting oxidative stress mediated cytotoxicity. Exposure to a sublethal concentration of ZnO …

A Logistic Approximation To The Cumulative Normal Distribution, Shannon R. Bowling, Mohammad T. Khasawneh, Sittichai Kaewkuekool, Byung R. Cho

Engineering Management & Systems Engineering Faculty Publications

This paper develops a logistic approximation to the cumulative normal distribution. Although the literature contains a vast collection of approximate functions for the normal distribution, they are very complicated, not very accurate, or valid for only a limited range. This paper proposes an enhanced approximate function. When comparing the proposed function to other approximations studied in the literature, it can be observed that the proposed logistic approximation has a simpler functional form and that it gives higher accuracy, with the maximum error of less than 0.00014 for the entire range. This is, to the best of the authors’ knowledge, the …

A Photochemically Initiated Chemistry For Coupling Underivatized Carbohydrates To Gold Nanoparticles, Xin Wang, Olof Ramström, Mingdi Yan

Chemistry Faculty Publications and Presentations

The sensitive optoelectronic properties of metal nanoparticles make nanoparticle-based materials a powerful tool to study fundamental biorecognition processes. Here we present a new and versatile method for coupling underivatized carbohydrates to gold nanoparticles (Au NPs) via the photochemically induced reaction of perfluorophenylazide (PFPA). A one-pot procedure was developed where Au NPs were synthesized and functionalized with PFPA by a ligand-exchange reaction. Carbohydrates were subsequently immobilized on the NPs by a fast light activation. The coupling reaction was efficient, resulting in high coupling yield as well as high ligand surface coverage. A colorimetric system based on the carbohydrate-modified Au NPs was …

Integration Of A Gis Learning System Into Civil Engineering Curricula: An Evaluation, Basanta Tandon

Masters Theses

"An evaluation of a web-based e-learning system to facilitate integration of Geographical Information Systems (GIS) into the Civil Engineering curriculum was conducted. The principal goals of the evaluation were to examine the effectiveness of the learning system and to develop a preliminary model to describe how students interact with the learning system. Quantitative and qualitative data were collected from 80 students who participated in a geotechnical engineering laboratory session, which covered soil borrow sites. Students rated the laboratory session as significantly more effective for learning, a nd more motivational than the class text. They also rated the lab significantly more …

Automated Offspring Sizing In Evolutionary Algorithms, André Chidi Nwamba

Masters Theses

"Evolutionary Algorithms (EAs) are a class of algorithms inspired by biological evolution. EAs are applicable to a wide range of problems; however, there are a number of parameters to set in order to use an EA. The performance of an EA is extremely sensitive to these parameter values; setting these parameters often requires expert knowledge of EAs. This prevents EAs from being more widely adopted by nonexperts. Parameter control, the automation of dynamic parameter value selection, has the potential to not only alleviate the burden of parameter tuning, but also to improve performance of EAs on a variety of problem …

Strict-Dominance Solvability Of Games On Continuous Strategy Spaces, Andrew Campbell Elkington

Theses and Dissertations (Comprehensive)

The concept of strict dominance provides a technique that can be used normatively to predict the play of games based only on the assumption of individual rationality. Such predictions, unlike those based on Nash equilibria, do not depend on players’ beliefs about the behaviour of others. One strategy strictly dominates another if and only if the payoff from the first strategy is strictly greater than the payoff from the second, no matter how the opponent(s) plays. It is possible for iterated elimination of strictly dominated strategies to remove all but a single choice for each player, in which case we …

Models For On-Line Social Networks, Noor Hadi

Theses and Dissertations (Comprehensive)

On-line social networks such as Facebook or Myspace are of increasing interest to computer scientists, mathematicians, and social scientists alike. In such real-world networks, nodes represent people and edges represent friendships between them. Mathematical models have been proposed for a variety of complex real-world networks such as the web graph, but relatively few models exist for on-line social networks.

We present two new models for on-line social networks: a deterministic model we call Iterated Local Transitivity (ILT), and a random ILT model. We study various properties in the deterministic ILT model such as average degree, average distance, and diameter. We …

Applications Of New Diffusion Models To Barrier Option Pricing And First Hitting Time In Finance, Keang Ly

Theses and Dissertations (Comprehensive)

The main focus of this thesis is in the application of a new family of analytical solvable diffusion models to arbitrage-free pricing exotic financial derivatives, such as barrier options. The family of diffusions is the so-called “Drifted Bessel family” having nonlinear (smile-like) local volatility with multiple adjustable parameters. In particular, the drifted Bessel-K diffusion is used to model asset (stock) price processes under a risk-neutral measure whereby discounted asset price are martingales.

Closed-form spectral expansions for barrier option values are derived within the Bessel-K family of models. This follow from the closed-form spectral expansions for the transition probability …

Simulation Studies On Estimation Of Variance Components For Multilevel Models, Sara Vakilian

Theses and Dissertations (Comprehensive)

With the presence of unequal sampling in a multilevel model, the weight inflated estimators for variance components can be biased even though the use of survey weights results in design consistent estimators of the parameters. In this thesis I will carry out a simulation study to examine the performance of current existing methods and I will examine the resampling method for correcting bias of estimators of variance components of a multilevel model with covariates. This study will be based on these three papers: “Weighting for Unequal Selection Probabilities in Multilevel Models” by D. Pfeffermann , C. J. Skinner, D.J. Holmes, …

Characterization Of Firn Microstructure Using Scanning Electron Microscopy: Implications For Physical Properties Measurements And Climate Reconstructions, Nicole Spaulding

Electronic Theses and Dissertations

Samples from 12 East Antarctic firn and ice cores were analyzed using scanning electron micrcoscopy (SEM) in order to first develop a technique for the accurate characterization of physical properties and then to investigate the relationship between the physical microstructure and chemical properties. Both physical properties, such as grain size and porosity, and chemical properties, such as major ion and trace element concentration, provide information about atmospheric temperature changes, impurity content, accumulation rate and deformation history; therefore the characterization of both types of properties is necessary. Further, knowledge of the relationship between the physical and chemical properties may increase our …

Modeling Ice Streams, Aitbala Sargent

Electronic Theses and Dissertations

Modeling glacier and ice sheet flow is a computationally challenging problem. The most challenging part in simulating ice sheet flow is modeling the fastest moving part of ice sheets, ice streams. In the first part of the thesis, we have constructed two numerical models of isothermal ice stream flow, a three-dimensional full-Stokes ice-sheet/ice-stream/ice-shelf model and a modified MacAyeal-Morland ice-stream/ice-shelf model. In the second part of the thesis, we studied the possibility of using SuperLU-DIST multiprocessor software package for solving the systems of linear equations generated by the model. The uniqueness of the modified MacAyeal-Morland model is in its inclusion of …

Satellite Photography: Instrumental, Rhetorical, Affective?, Irangi Kaushalya Egodapitiya

Masters Theses

"This study examines how tsunami satellite images operate and could provoke various interpretations. The goal of this research project is to study whether the interpretation of tsunami satellite images could extend beyond scientific features to affective messages. Primarily based on the satellite images of Sri Lanka taken before and during the 2004 tsunami, this study analyses: How could mechanical satellite images, taken automatically by a machine in orbit, become an object of profound emotional meaning?; How do viewer's experiences, knowledge, and discourse affect their interpretations of mechanical artifacts?; How are tsunami satellite images connected to affective responses by viewers?; How …

Information Flow Properties For Cyber-Physical Systems, Rav Akella

Masters Theses

"In cyber-physical systems, which are the integrations of computational and physical processes, security properties are difficult to enforce. Fundamentally, physically observable behavior leads to violations of confidentiality. This work analyzes certain noninterference based security properties to ensure that interactions between the cyber and physical processes preserve confidentiality. A considerable barrier to this analysis is the representation of physical system interactions at the cyber-level. This thesis presents encoding of these physical system properties into a discrete event system and represents the cyber-physical system using Security Process Algebra (SPA). The model checker, Checker of Persistent Security (CoPS) shows Bisimulation based NonDeducibility on …

Electricity Generation And Ethanol Production Using Iron-Reducing, Haloalkaliphilic Bacteria, Varun Paul

Masters Theses

"Microbial life in extreme environments has been studied primarily for their metabolic activities. Very few commercial or industrial applications have been known from these systems. In this study, the metabolic pathways and properties of bacteria from a haloalkaliphilic environment of Soap Lake, Washington were employed in two research applications related to energy production. In the first study, the bacterial cultures that were known to reduce iron (III) were used in a Microbial Fuel Cell (MFC) reactor. Iron reducing bacteria have shown to shunt their electrons on to the surface of a carbon electrode of an MFC, and the electrons can …

Nona-Arginine Peptides Facilitate Cellular Entry Of Semiconductor Nanocrystals: Mechanisms Of Uptake, Yi Xu

Masters Theses

"Luminescent semiconductor quantum dots (QDs) have recently been used for delivering and monitoring biomolecules, such as drugs and proteins. However, QDs alone have a very low efficiency of transport across the plasma membrane. In order to increase the efficiency of QD delivery, synthetic nona-arginine (sR9) was used, a cell penetrating peptide, to facilitate uptake. Data demonstrated that sR9 could significantly increase the cellular uptake of QDs by noncovalent binding between QDs and sR9. Furthermore, the mechanisms of QD/sR9 cellular internalization were investigated. Low temperature and metabolic inhibitors markedly inhibited the uptake of QD/sR9, indicating that internalization is an energy-dependent process. …

Quantitative Rescattering Theory For Nonsequential Double Ionization Of Atoms By Intense Laser Pulses, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

Laser-induced electron recollisions are fundamental to many strong field phenomena in atoms and molecules. Using the recently developed quantitative rescattering theory, we demonstrate that the nonsequential double ionization (NSDI) of atoms by lasers can be obtained quantitatively in terms of inelastic collisions of the target ions with the free returning electrons where the latter are explicitly given by a spectrum-characterized wave packet. Using argon atoms as target, we calculated the NSDI yield including contributions from direct (e,2e) electron-impact ionization and electron-impact excitation accompanied by subsequent field ionization. We further investigate the dependence of total NSDI on the carrier-envelope phase of …

The Search For Quantum Critical Scaling In A Classical System, Jagat Lamsal, John Gaddy, Marcus Petrovic, Wouter Montfrooij, Thomas Vojta

Physics Faculty Research & Creative Works

Order-disorder phase transitions in magnetic metals that occur at zero temperature have been studied in great detail. Theorists have advanced scenarios for these quantum critical systems in which the unusual response can be seen to evolve from a competition between ordering and disordering tendencies, driven by quantum fluctuations. Unfortunately, there is a potential disconnect between the real systems that are being studied experimentally, and the idealized systems that theoretical scenarios are based upon. Here we discuss how disorder introduces a change in morphology from a three-dimensional system to a collection of magnetic clusters, and we present neutron scattering data on …

Kinetic Energy Release Distributions For C⁺₂ Emission From Multiply Charged C₆₀ And C₇₀ Fullerenes, Henrik Cederquist, Nicole Haag, Zoltan Berenyi, Peter Reinhed, Daniel Fischer, M. Gudmundsson, Birgitta W. Johansson, Torsten Schmidt, Henning Zettergren

Physics Faculty Research & Creative Works

We present asystematic study of experimental kinetic energy release distributions for the asymmetric fission processes C^q+₆₀ C^(iq-1<)+₇₀+ C⁺₂ and C ^q+₇₀ C^(q-1)+₆₀+ C⁺ ₂ for mother ions incharge states q 4-8 produced incollisions with slow highly charged ions. Somewhat to our surprise, we find that the KERD for asymmetric fission from C^q+₆₀ are considerably wider and have larger most likely values than the C^q+₇₀ distributions inthe corresponding charge states when q > 4.

Kentucky River Basin, Daniel I. Carey

Map and Chart--KGS

The Kentucky River Basin's nearly 7,000 square miles in 42 counties contain 16,000 miles of streams. From a hill in Letcher County 3,250 feet above sea level, and the Kentucky River runs down the Eastern Kentucky Coal Field, Knobs, and Bluegrass Regions to the Ohio River at 420 feet above sea level.

Along the way the river washes rocks laid down as sediments over a period of 150 million years—past the 300-million-year-old sandstone, siltstone, shale, and Camp Nelson limestones at the base of the Kentucky River Palisades in central Kentucky.

Residents draw about 100 million gallons of water per day …

Big Sandy/Little Sandy And Tygarts Creek Basins, Daniel I. Carey

Map and Chart--KGS

Nearly 7,600 miles of streams flow through the basin's 3,440 square miles in 14 counties to the Tug Fork, Big Sandy River, and Ohio River. The Tygarts Creek–Little Sandy River Basin includes 1,160 square miles. The Big Sandy River Basin has 2,285 square miles in Kentucky and 1,950 square miles in West Virginia and Virginia. There are nearly 17,000 acres of wetlands, including water bodies.

Residents draw about 27 million gallons of water per day (mgd) from streams and reservoirs in the basin. About three in five residents are on public water; other households rely primarily on domestic wells. Only …

The Mississippian Section At Paddys Bluff, Crittenden County, Kentucky, Ron Counts, F. Brett Denny, James C. Hower, Zakaria Lasemi, Rodney D. Norby, Paul E. Potter, Scott Waninger, David A. Williams

Map and Chart--KGS

Paddys Bluff (Figs. 1-3) is located on the south side of the Illinois Basin on the Cumberland River, 1.7 miles downstream from Dycusburg in Crittenden County, Ky., in Carter coordinate section 23-I-16 and ecoregion 71f of the Western Highland Rim of Kentucky (Woods and others, 2002). This bluff is on a right-descending bend 18 liver miles above its junction with the Ohio River at Smithland, Livingston County. The bluff (Figs. 4A, B) is locally famous as the location for a scene from the classic 1962 film, "How the West Was Won,' a winner of three Academy Awards, starling James Stewart, …

Mapped Karst Groundwater Basins In The Tell City And Part Of The Jasper 30 X 60 Minute Quadrangles, Joseph A. Ray, Jack R. Moody, Robert J. Blair, James C. Currens, Randall L. Paylor

Map and Chart--KGS

No abstract provided.

Satisfaction Assessment Of Textual Software Engineering Artifacts, Elizabeth Ashlee Holbrook

University of Kentucky Doctoral Dissertations

A large number of software projects exist and will continue to be developed that have textual requirements and textual design elements where the design elements should fully satisfy the requirements. Current techniques to assess the satisfaction of requirements by corresponding design elements are largely manual processes that lack formal criteria and standard practices. Software projects that require satisfaction assessment are often very large systems containing several hundred requirements and design elements. Often these projects are within a high assurance project domain, where human lives and millions of dollars of funding are at stake. Manual satisfaction assessment is expensive in terms …

Alterations Of Zinc Transporters In Alzheimer's Disease, Ganna Lyubartseva

University of Kentucky Doctoral Dissertations

Alzheimer’s disease (AD), one of the major causes of disability and mortality in Western societies, is a progressive age-related neurodegenerative disorder. Increasing evidence suggests the etiology of AD may involve disruptions of zinc (Zn) homeostasis. We hypothesize that disruption of Zn homeostasis leads to alterations of Zn transporter (ZnT) proteins, resulting in increased production of neurotoxic amyloid beta (Aβ) peptide in AD brain. To address this hypothesis we carried out the following studies.

1. We characterized alterations of ZnT-1, ZnT-4 and ZnT-6 in the brain of preclinical AD (PCAD) subjects, who show no overt clinical manifestations of AD but demonstrate …

Rees Products Of Posets And Inequalities, Tricia Muldoon Brown

University of Kentucky Doctoral Dissertations

In this dissertation we will look at properties of two different posets from different perspectives. The first poset is the Rees product of the face lattice of the n-cube with the chain. Specifically we study the Möbius function of this poset. Our proof techniques include straightforward enumeration and a bijection between a set of labeled augmented skew diagrams and barred signed permutations which label the maximal chains of this poset. Because the Rees product of this poset is Cohen-Macaulay, we find a basis for the top homology group and a representation of the top homology group over the symmetric …

Study Of Qcd Critical Point Using Canonical Ensemble Method, Anyi Li

University of Kentucky Doctoral Dissertations

QCD at non-zero baryon density is expected to have a critical point where the finite temperature crossover at zero density turns into a first order phase transition. To identify this point, we use the canonical ensemble approach to scan the temperaturedensity plane through lattice QCD simulations with Wilson-type fermions. In order to scan a wide range of the phase diagram, we develop an algorithm, the ”winding number expansion method” (WNEM) to fix the numerical instability problem due to the discrete Fourier transform for calculating the projected determinant. For a given temperature, we measure the chemical potential as a function of …