Physical Sciences and Mathematics Commons^™

Modeling, Analysis, And Simulation Of Discrete-Continuum Models Of Step-Flow Epitaxy: Bunching Instabilities And Continuum Limits, Nicholas O. Kirby

University of Kentucky Doctoral Dissertations

Vicinal surfaces consist of terraces separated by atomic steps. In the step-flow regime, deposited atoms (adatoms) diffuse on terraces, eventually reaching steps where they attach to the crystal, thereby causing the steps to move. There are two main objectives of this work. First, we analyze rigorously the differences in qualitative behavior between vicinal surfaces consisting of infinitely many steps and nanowires whose top surface consists of a small number of steps bounded by a reflecting wall. Second, we derive the continuum model that describes the macroscopic behavior of vicinal surfaces from detailed microscopic models of step dynamics.

We use the …

Some Contributions To The Censored Empirical Likelihood With Hazard-Type Constraints, Yanling Hu

University of Kentucky Doctoral Dissertations

Empirical likelihood (EL) is a recently developed nonparametric method of statistical inference. Owen’s 2001 book contains many important results for EL with uncensored data. However, fewer results are available for EL with right-censored data. In this dissertation, we first investigate a right-censored-data extension of Qin and Lawless (1994). They studied EL with uncensored data when the number of estimating equations is larger than the number of parameters (over-determined case). We obtain results similar to theirs for the maximum EL estimator and the EL ratio test, for the over-determined case, with right-censored data. We employ hazard-type constraints which are better able …

Development Of Luminescent Sensing Systems With Clinical Applications, Daniel F. Scott

University of Kentucky Doctoral Dissertations

As the move towards the miniaturization of many diagnostic and detection systems continues, the need for increasingly versatile yet sensitive labels for use in these systems also grows. Luminescent reporters provide us with a solution to many of the issues at hand through their unique and favorable characteristics. Bioluminescent proteins offer detection at extremely low concentrations and no interference from physiological fluids leading to excellent detection limits, while the vast number of fluorescent proteins and molecules available allows the opportunity to select a tailored reporter for a specific task. Both provide relatively simply instrumentation requirements and have exhibited great promise …

A Reliability-Based Routing Protocol For Vehicular Ad-Hoc Networks, James Bernsen

University of Kentucky Master's Theses

Vehicular Ad hoc NETworks (VANETs), an emerging technology, would allow vehicles to form a self-organized network without the aid of a permanent infrastructure. As a prerequisite to communication in VANETs, an efficient route between communicating nodes in the network must be established, and the routing protocol must adapt to the rapidly changing topology of vehicles in motion. This is one of the goals of VANET routing protocols. In this thesis, we present an efficient routing protocol for VANETs, called the Reliable Inter-VEhicular Routing (RIVER) protocol. RIVER utilizes an undirected graph that represents the surrounding street layout where the vertices of …

Parametric Estimation In Competing Risks And Multi-State Models, Yushun Lin

Theses and Dissertations--Statistics

The typical research of Alzheimer's disease includes a series of cognitive states. Multi-state models are often used to describe the history of disease evolvement. Competing risks models are a sub-category of multi-state models with one starting state and several absorbing states.

Analyses for competing risks data in medical papers frequently assume independent risks and evaluate covariate effects on these events by modeling distinct proportional hazards regression models for each event. Jeong and Fine (2007) proposed a parametric proportional sub-distribution hazard (SH) model for cumulative incidence functions (CIF) without assumptions about the dependence among the risks. We modified their model to …

Engineering Proteins With Unique Characteristics For Diagnostics And Biosensors, Smita Joel

University of Kentucky Doctoral Dissertations

Proteins possess a broad range of structural and functional properties and, therefore, can be employed in a variety of biomedical applications. While a good number of protein-based biosensing systems and biosensors for target analytes have been developed, the search for versatile, highly sensitive and selective sensors with long term stability able to provide fast detection of target analytes continues to be a challenge. To that end, we now report the design and development of modified proteins with tailored characteristics and their further utilization in the development of biosensing systems.

We take advantage of binding proteins that undergo a change in …

Studies On Silicon Nmr Characterization And Kinetic Modeling Of The Structural Evolution Of Siloxane-Based Materials And Their Applications In Drug Delivery And Adsorption, Jyotrhirmai Ambati

University of Kentucky Doctoral Dissertations

This dissertation presents studies of the synthetic processes and applications of siloxane-based materials. Kinetic investigations of bridged organoalkoxysilanes that are precursors to organic-inorganic hybrid polysilsesquioxanes are a primary focus. Quick gelation despite extensive cyclization is found during the polymerization of bridged silane precursors except for silanes with certain short bridges. This work is an attempt to characterize and understand some of the distinct features of bridged silanes using experimental characterization, kinetic modeling and simulation. In addition to this, the dissertation shows how the properties of siloxane- materials can be engineered for drug delivery and adsorption.

The phase behavior of polymerizing …

New Photovoltaic Acceptors: Synthesis And Characterization Of Functionalized C-Fused Anthradithiophene Quinones, Kerri Shelton

University of Kentucky Master's Theses

Stable organic semiconductors are critical to produce inexpensive, efficient and flexible thin film organic solar cells. A current chemical focus is the synthesis of stable, electron-accepting materials to be utilized as an acceptor layer in photovoltaics.¹ The Anthony group has shown that the functionalization of pentacene with suitable electron withdrawing groups provides a catalog of suitable acceptors for this purpose.² These pentacenes can be further modified to pack in a unique 1-dimensional "sandwich herringbone" crystal packing, leading to improved device current.³ To improve the stability of acene acceptors, we have taken two hetero-atom themed approaches. First, we …

Development Of Novel Electrophilic Ruthenium(Ii) And Iridium(Iii) Complexes And Their Applications As Homogeneous Catalysts, Ryan R. Ketcham

University of Kentucky Master's Theses

Our aim was to develop the synthetic potential and reaction chemistry of Ir³⁺ and Ru²⁺ electrophiles by preparing well-characterized complexes whose properties are controllable by modification of the ancillary ligand environment Specifically, we prepared a series of ruthenium complexes to serve as selective hydrogenation and hydrogenolysis catalysts of furan derivatives. We also expanded the synthesis of electrophilic Ir³⁺ di-thiolate complexes. These types of compounds could eventually serve as catalysts precursors for the addition of weak nucleophiles to alkynes and nitriles.

Conceptualizing And Improving Red Wine Grape Cultivars Grown In Kentucky, Matthew Simson

University of Kentucky Master's Theses

Wine sensory attributes are associated with quality of wines. Cabernet Franc did not possess good coloration of its wine. Therefore, in the 2009 and 2010 growing seasons, studies including the sampling of four red wine grape cultivars from the end of flowering throughout the rest of the season and applying treatments to Cabernet Franc grapevines at veraison were commenced to address suitability and color enhancement, respectively. The study examining Cabernet Franc, Cabernet Sauvignon, Chambourcin, and Norton looked at sampling their grapes at two-week intervals from times post-flowering to understand the demands of each cultivar during key stages of berry development, …

Investigation Of The Toxicity And Efflux Of Polychlorinated Biphenyls And Hydroxylated Polychlorinated Biphenyls In Escherichia Coli, Shen Geng

University of Kentucky Master's Theses

Polychlorinated biphenyls (PCBs) are persistent organic pollutants. Due to their properties, PCBs accumulate in the food-chain and post a threat to the health of human beings and wildlife. Hydroxylated PCBs (OH-PCBs) are oxidative metabolites of PCBs and are more hydrophilic than their parent PCBs. One of the best approaches to break down these contaminants is through bioremediation, which is an environmental friendly process that uses microorganisms to restore natural environment.

Towards this goal, we have investigated the toxicity and accumulation of PCBs and OH-PCBs in a Gram-negative bacterium, Escherichia coli. We have also determined the role played by a …

Cluster-Based Term Weighting And Document Ranking Models, Keerthiram Murugesan

University of Kentucky Master's Theses

A term weighting scheme measures the importance of a term in a collection. A document ranking model uses these term weights to find the rank or score of a document in a collection. We present a series of cluster-based term weighting and document ranking models based on the TF-IDF and Okapi BM25 models. These term weighting and document ranking models update the inter-cluster and intra-cluster frequency components based on the generated clusters. These inter-cluster and intra-cluster frequency components are used for weighting the importance of a term in addition to the term and document frequency components. In this thesis, we …

Cell And Protein-Based Sensing Systems For The Detection Of Environmentally And Physiologically Relevant Molecules, Kendrick Bruce Turner

Theses and Dissertations--Chemistry

The detection of small molecules in complex sample matrices such as environmental (surface and ground water, sediment, etc.) and biological (blood, serum, plasma, etc.) samples is of paramount importance for monitoring the distribution of environmental pollutants and their patterns of exposure within the population as well as diagnosing and managing diseases. Biosensors have demonstrated a singular ability to sensitively and selectively detect analytes in complex samples without the need for extensive sample preparation and pretreatment. Nature has demonstrated myriad examples of exquisite selectivity in spite of complexity and we seek to take advantage of that attribute in the development of …

Novel Solution Processable Acceptors For Organic Photovoltaic Applications, Ying Shu

University of Kentucky Doctoral Dissertations

The field of organic electronics has become an increasingly important field of research in recent years. Organic based semiconductors have the potential for creating inexpensive, solution processed devices on flexible substrates. Some of the applications of organic semiconductors include organic field effect transistors, organic light emitting diodes and organic photovoltaics.

Functionalized pentacenes have been proven to be viable donor materials for use in organic photovoltaic devices. The goal of this research is to synthesize and test the viability of novel electron deficient pentacenes and pentacene based materials as acceptors to be used as drop-in replacements for PCBM in bulk-heterojunction organic …

Gauge-Gravity Duality And Its Applications To Cosmology And Fluid Dynamics, Jae-Hyuk Oh

University of Kentucky Doctoral Dissertations

This thesis is devoted to the study of two important applications of gauge-gravity duality: the cosmological singularity problem and conformal fluid dynamics. Gauge-gravity duality is a concrete dual relationship between a gauge theory (such as electromagnetism, the theories of weak and strong interactions), and a theory of strings which contains gravity. The most concrete application of this duality is the AdS/CFT correspondence, where the theory containing gravity lives in the bulk of an asymptotically anti-de-Sitter space-time, while the dual gauge theory is a deformation of a conformal field theory which lives on the boundary of anti-de-Sitter space-time(AdS).

Our first application …

Depositional And Stratigraphic Significance Of Marine, Green-Clay, Mineral Facies In The Lower-Middle Mississippian Borden And Fort Payne Formations, Western Appalachian And Eastern Illinois Basins, Kentucky, Devi Bhagabati Prasad Udgata

University of Kentucky Doctoral Dissertations

Detailed study of strata associated with the glauconite-rich Floyds Knob Bed in the western Appalachian and eastern Illinois basins have corroborated previous interpretations that the unit is a widespread, largely synchronous marker horizon. However, in some areas there are multiple glauconite beds; in others a distinct bed is lacking, but the glauconite is dispersed throughout many beds, forming an interval rather than a distinct bed. In Kentucky and adjacent states, the Floyds Knob interval, in upper parts of the Lower-Middle Mississippian Borden-Grainger delta sequence and in lower parts of the Fort Payne carbonate sequence, was deposited at the end of …

Interactions And Effects Of Biomolecules On Au Nanomaterial Surfaces, Manish Sethi

University of Kentucky Doctoral Dissertations

Au nanoparticles are increasingly being used in biological applications. Their use is of interest based upon their unique properties that are achieved at the nanoscale, which includes strong optical absorbances that are size and aggregation state dependent. Such absorbances can be used in sensitive chemical/biological detection schemes where bioligands can be directly attached to the nanoparticle surface using facile methods. Unfortunately, a number of complications persist that prevent their wide-scale use. These limitations include minimal nanoparticle stability in biological-based media of high ionic strength, unknown surface functionalization effects using simple biomolecules, and determining the binding motifs of the ligands to …

Three Dimensional Modeling And Animation Of Facial Expressions, Alice J. Lin

University of Kentucky Doctoral Dissertations

Facial expression and animation are important aspects of the 3D environment featuring human characters. These animations are frequently used in many kinds of applications and there have been many efforts to increase the realism. Three aspects are still stimulating active research: the detailed subtle facial expressions, the process of rigging a face, and the transfer of an expression from one person to another. This dissertation focuses on the above three aspects.

A system for freely designing and creating detailed, dynamic, and animated facial expressions is developed. The presented pattern functions produce detailed and animated facial expressions. The system produces realistic …

Fate Of Stable Isotope Label During Predation Of 15N-Tagged Wild-Type Escherichia Coli By Protozoa, Ashley M. Barton

University of Kentucky Master's Theses

Currently, bacterial movement in karst aquifers is not well understood. Use of stable isotopes to label non-pathogenic Escherichia coli as a particulate groundwater tracer in karst systems has been examined in previous studies. Loss of the stable isotope signal is anticipated in traces greater than 500 m in length. Potential loss of ¹⁵N due to predation by protozoa was examined. Filter-sterilized water from Royal Spring in Georgetown, Kentucky, was inoculated with a mixture of either Tetrahymena pyriformis or Colpoda steinii and ¹⁵N-enriched E. coli and stored in the dark at 14°C. Samples were analyzed for their nitrogen isotope …

Determining Interstellar Reddening: A New Approach Using Spectroscopy And Photometry, Syed A. Uddin

University of Kentucky Master's Theses

The mystery of Canis Major overdensity is addressed. We discuss concurrent methods and their limitations on the determination of interstellar reddening. We establish a new way to determine line of sight interstellear reddening by observing stellar spectral lines and UBV colors. We observe and analyze spectra of 22 stars in different open clusters. We find that Hydrogen Balmer line at 4861 angstrom can predict the stellar atmospheric parameters and intrinsic colors with reasonable accuracy. Comparing with observed colors we derive the reddening of the stars. We compare our results with standard database WEBDA and find that within 90% probability limit …

Chemical Evolution And Residence Time Of Groundwater In The Wilcox Aquifer Of The Northern Gulf Coastal Plain, Estifanos Haile

Theses and Dissertations--Earth and Environmental Sciences

This study aims to integrate groundwater geochemistry and mathematical modeling to determine the dominant geochemical processes and groundwater residence time within the Wilcox aquifer in the northern Gulf Coastal Plain. Groundwater samples were collected and analyzed for major ion chemistry, stable isotopes (¹⁸O, ²H, and ¹³C), and radioisotope ³⁶Cl content. Geochemical modeling enabled the identification of major sources and sinks of solutes in the aquifer. A two-dimensional, finite-difference, numerical model was used to determine the deep groundwater flow rate and transport of ³⁶Cl in the aquifer. Major ion chemistry shows a chromatographic pattern along …

Magnetic Shielding Studies For The Neutron Electric Dipole Moment Experiment At The Spallation Neutron Source, Susan Kate Malkowski

Theses and Dissertations--Physics and Astronomy

The neutron Electric Dipole Moment Experiment at the Spallation Neutron Source requires an overall magnetic shielding factor of order 10⁵ to attenuate external background magnetic fields. At present, the shielding design includes an external (room-temperature) multi-layer μ-metal magnetic shield, a cryogenic (4 Kelvin) Pb superconducting shield, and a cryogenic (4 Kelvin) ferromagnetic shield composed of Metglas ribbon. This research determined how to construct a Metglas shield using minimal material that produced axial and transverse shielding factors of ~267 and ~1500. In addition, the μ-metal and Metglas shields were modeled using finite element analysis. The FEA model includes external coils …

Structural Evolution Of An Intracratonic Rift System; Mississippi Valley Graben, Rough Creek Graben, And Rome Trough Of Kentucky, Usa, John Bibb Hickman Jr.

University of Kentucky Doctoral Dissertations

As indicated by drilling and geophysical data, the Mississippi Valley Graben, the Rough Creek Graben, together with the Rome Trough of eastern Kentucky and West Virginia, are fault-bounded graben structures filled with as much as 27,000 feet of Early to Middle Cambrian sediments. Detailed regional mapping of Cambrian and younger strata within and surrounding these structures indicates that they formed contemporaneously. The proximity of these structures suggests they developed within the same regional stress fields and tectonic environments. These three structures are mechanically and kinematically connected, and formed part of a single continent-scale rift system produced during the breakup of …

A Systematic Study Of Thermodynamic And Transport Properties Of Layered 4d And 5d Correlated Electron Systems, Shalinee Chikara

University of Kentucky Doctoral Dissertations

Correlated electron materials have been at the forefront of condensed matter research in the past couple of decades. Correlation in materials, especially, with open d and f electronic shells often lead to very exciting and intriguing phenomenon like high temperature superconductivity, Mott metal-insulator transition, colossal magnetoresistance (CMR). This thesis focuses on triple-layered Sr₄Ru₃O₁₀, Sr substituted double layered (Ca1-- xA_x)₃Ru₂O₇ (A = Ba, Sr) and 5d system Sr₂IrO₄ and Sr₃Ir₂O₇. Triple-layered Sr₄Ru₃O_{10 …}

Bedrock Geology And Tectonic Evolution Of The Western Central Maine Zone, South Central Massachusetts, Thomas Bradley Walker

Theses and Dissertations--Earth and Environmental Sciences

Bedrock geology of the East Brookfield quadrangle (EBQ), based on new 1:24000 scale mapping, consists of an interfolded sequence of Rangeley Fm. and Paxton Fm. metasediments, intruded by Early Mississippian tonalitic to granitic orthogneisses and underlain in the western half by folded orthogneisses of unknown age. Pervasive flattening strains have created planar, generally NNE-SSW striking and consistent moderately west dipping foliations. Generally strike-parallel stretching lineations and boudinage structures, with rarer dip parallel stretching lineations, reflect extrusion of CMZ metasediments and orthogneisses with a flattening component. Mapping in the EBQ demonstrates that a transition between deformational mechanisms of the southern Central …

Arsenic Heterogeneity In Aquifer Sediments From West Bengal, India, Emily Eastridge

Theses and Dissertations--Earth and Environmental Sciences

Multiple studies in the Bengal basin have shown that elevated As in groundwater coincides with reduced, relatively dark sediments of Himalayan provenance. In West Bengal state (India), As concentrations > 10 μg/L tend to occur east of the River Bhagirathi-Hoogly, the main distributary of the Ganges. Associations among sediment chemistry and mineralogy for four cores from either side of the Bhagirathi-Hoogly (cores 1 and 2 to the east, 3 and 4 to the west) in Murshidabad district were investigated. Ten sediment samples were collected from each boring at various depths to a maximum of 38 to 43 m. Sediment chemistry was …

Checkpointing And Recovery In Distributed And Database Systems, Jiang Wu

Theses and Dissertations--Computer Science

A transaction-consistent global checkpoint of a database records a state of the database which reflects the effect of only completed transactions and not the re- sults of any partially executed transactions. This thesis establishes the necessary and sufficient conditions for a checkpoint of a data item (or the checkpoints of a set of data items) to be part of a transaction-consistent global checkpoint of the database. This result would be useful for constructing transaction-consistent global checkpoints incrementally from the checkpoints of each individual data item of a database. By applying this condition, we can start from any useful checkpoint of …

Locating Hot Spots Of Fecal Pollution In An Urban Watershed Of Central Kentucky Using Bacteroides 16s Rrna Markers, Tricia L. Coakley

Theses and Dissertations--Earth and Environmental Sciences

The field of molecular fecal source tracking in the water environment has developed rapidly since the first PCR assays for general and host-­‐specific Bacteroides 16s rRNA markers were published. Numerous host-­‐specific molecular markers and PCR assays have been developed, adding greater specificity, sensitivity and quantitative methods to the array of options. The public demand for readying methods for transfer to the commercial lab, so that they may be used to generate data for public utilities, citizen action groups and regulatory agencies, has fueled the development of an entire new research community. These methods, however plentiful, have not found community agreement …

On Simple But Hard Random Instances Of Propositional Theories And Logic Programs, Gayathri Namasivayam

University of Kentucky Doctoral Dissertations

In the last decade, Answer Set Programming (ASP) and Satisfiability (SAT) have been used to solve combinatorial search problems and practical applications in which they arise. In each of these formalisms, a tool called a solver is used to solve problems. A solver takes as input a specification of the problem – a logic program in the case of ASP, and a CNF theory for SAT – and produces as output a solution to the problem. Designing fast solvers is important for the success of this general-purpose approach to solving search problems. Classes of instances that pose challenges to solvers …

Partially Halogenated Acenes And Heteroacenes For Organic Electronics, Balaji Purushothaman

University of Kentucky Doctoral Dissertations

Inorganic materials have dominated electronic applications such as photovoltaic cells, thin film transistors (TFTs) and light emitting diodes (LEDs). However developments in the field of organic electronics over the past three decades have enabled the use of organic materials in these devices. While significant improvements have been made to improve their electronic properties there are several road blocks towards commercial application. One of the significant obstacles is the poor charge carrier mobility associated with organic semiconductors processed by well established printing methods. The goal of my research project is to improve the charge carrier mobility of solution cast films of …