Physical Sciences and Mathematics Commons^™

A Silylation-Based Kinetic Resolution Of Hydroxy Lactones And Lactams With Subsequent Mechanistic Investigations, Robert W. Clark

Theses and Dissertations

The work contained herein focuses on the methodology and design of new reactions for the production of stereoenriched compounds. The primary focus of research discussed is kinetic resolution, a classic and powerful methodology for the separation of a single enantiomer from a racemic mixture. In 2011, a silylation-based resolution catalyzed by a chiral isothiourea produced synthetically useful selectivity factors for mono-functional secondary alcohols. In chapter 2, this methodology was subsequently expanded to include α-hydroxy lactones with selectivity factors up to 100. This study resulted in the most selective reaction reported to date for the aforementioned silylation-based resolution. In addition to …

Commutator Studies In Pursuit Of Finite Basis Results, Nathan E. Faulkner

Theses and Dissertations

Several new results of a general algebraic scope are developed in an effort to build tools for use in finite basis proofs. Many recent finite basis theorems have involved assumption of a finite residual bound, with the broadest result concerning varieties with a difference term (Kearnes, Szendrei, and Willard (2013+)). However, in varieties with a difference term, the finite residual bound hypothesis is known to strongly limit the degree of nilpotence observable in a variety, while, on the other hand, there is another, older series of results in which nilpotence plays a key role (beginning with those of Lyndon (1952) …

The Packing Chromatic Number Of Random D-Regular Graphs, Ann Wells Clifton

Theses and Dissertations

Let G = (V (G),E(G)) be a simple graph of order n and let i be a positive integer. X_i superset V (G) is called an i-packing if vertices in X_i are pairwise distance more than i apart. A packing coloring of G is a partition X = {X₁,X₂,X₃, . . . ,X_k} of V (G) such that each color class X_i is an i-packing. The minimum order k of a packing coloring is called the packing chromatic number of G, denoted by X_p(G). Let G_{n,d …}

Brand Positioning Map And Analysis Using Web Scraping And Advertisement Analysis, Surya Bhatt

Theses and Dissertations

There’s a significant increase in online consumer forums. When customers set out to buy a product they use these forums to form an opinion. Our research focuses on comparing Brand positioning maps based on consumer reviews. We also analyse the impact of advertisements and expert reviews. Our goal is to show that combining consumer reviews with ads and electronic media will help us analyze the effectiveness of advertising on brand positioning maps. This approach shall also help us in making association graphs for a brand using words of perception/opinion associated with that brand/product. Which may in turn assist companies in …

3-D Numerical Simulation Of Carbon Dioxide Injection Into The South Georgia Rift Basin For Geologic Storage, Daniel Eric Taylor Brantley

Theses and Dissertations

This study numerically simulated the injection of supercritical phase CO2 into the South Georgia Rift (SGR) basin to evaluate the feasibility and efficacy of long term geologic storage. The injection simulation modeling was divided into two phases. During phase one of the modeling, very little geologic and reservoir dynamics data was known about the SGR basin. Due to lack of basin data, an equilibrium model was used to estimate the initial hydrostatic pressure, temperature and salinity gradients that represent our study area. For the equilibrium model, the USGS SEAWAT program was used and for the CO2 injection simulation, TOUGH2-ECO2N was …

A Botanical Survey Of Native And Non-Native Species Along The Three Rivers Greenway In Columbia, South Carolina, Rebecca L. Givens

Theses and Dissertations

Baseline surveys are important tools in establishing the present flora located within an area for future monitoring. In addition, knowledge of invasive species presence is essential to help maintain native ecosystem biodiversity. This study aimed to establish a baseline inventory of plant species found along a portion of the Three Rivers Greenway in Columbia, South Carolina, and to create a comprehensive list of native and invasive plant species within this area. In addition, a geographic information system (GIS) was employed to show the spread of a particular known invasive plant species, Hedera helix within the area. Specimens were collected in …

Complexity In Overmarsh Circulation, Jessica Chassereau Sullivan

Theses and Dissertations

Overmarsh circulation is highly complex with variations in current direction over very short timescales and flowpaths that differ substantially between flood and ebb cycles. Understanding such flow complexities in salt marshes is important because they inherently impact the distribution of sediment, larvae and nutrients throughout the marsh, and hence, the ecogeomorphic feedbacks that control landscape evolution. The purpose this Ph.D. research is to quantitatively evaluate the effects of salt marsh topography on overmarsh circulation in a Georgia salt marsh. This dissertation is comprised of three parts. First, digital elevation models (DEMs) were compared to characterize how well airborne lidar (light …

Modeling And Computations Of Cellular Dynamics Using Complex-Fluid Models, Jia Zhao

Theses and Dissertations

Cells are fundamental units in all living organisms as all living organisms are made up of cells of different varieties. The study of cells is therefore an essential part of research in life science. Cells can be classified into two basic types: prokaryotic cells and eukaryotic cells. One typical organisms of prokaryotes is bacterium. And eukaryotes mainly consist of animal cells. In this thesis, we focus on developing predictive models mathematically to study bacteria colonies and animal cell mitotic dynamics.

Instead of living alone, bacteria usually survive in a biofilm, which is a microorganism where bacteria stick together by extracellular …

Neutrino And Antineutrino Induced Meson Production, Libo Jiang

Theses and Dissertations

Coherent meson production measurement is very important in physics research. First, the coherent pion production is a potential background to v oscillation in next generation of Long Base Line Experiment(ELBNF/DUNE); second, coherent pion and coherent p production provide a detailed test of CVC and PCAC hypothesis; third, coherent meson production can be used to monitor the neutrino and anti-neutrino fluxes in the experiment. This dissertation focuses on two parts: coherent pi production in NOMAD, and coherent p simulation using LBNF fluxes. With the NOMAD data, the ratio between cross-sections of coherent pi- and v charged current interactions was measured and …

Bayesian Semi- And Non-Parametric Analysis For Spatially Correlated Survival Data, Haiming Zhou

Theses and Dissertations

Flexible incorporation of both geographical patterning and risk effects in cancer survival models is becoming increasingly important, due in part to the recent availability of large cancer registries. The analysis of spatial survival data is challenged by the presence of spatial dependence and censoring for survival times. Accurately modeling the risk factors and geographical pattern that explain the differences in survival is particularly of interest. Within this dissertation, the first chapter reviews commonlyused baseline priors, semiparametric and nonparametric Bayesian survival models and recent approaches for accommodating spatial dependence, both conditional and marginal. The last three chapters contribute three flexible survival …

Iridium – Bismuth Carbonyl Cluster Complexes: New Directions For Chemistry And Selective Oxidation Catalysis, Gaya R. Elpitiya

Theses and Dissertations

CHAPTER 2 The reaction of Ir3(CO)9(μ3-Bi), 2.1, with BiPh3 has yielded a iridium−bismuth cluster complex Ir5(CO)10(μ3-Bi)2(μ4-Bi), 2.2. The first examples of bimetallic iridium−bismuth nanoparticles have been subsequently synthesized from 2.1 and 2.2, and these have been securely anchored onto the inner walls of mesoporous silica. These isolated, bimetallic iridium−bismuth nanoparticles display a superior catalytic performance, when compared to their analogous monometallic counterparts and equivalent physical mixtures, in the C−H activation of 3-picoline to yield niacin.

CHAPTER 3 The reaction of Ir3(CO)9(μ3-Bi) with Ph3GeH yielded the compound Ir3(CO)6(GePh3)3(μ3-Bi)(μ-H)3 3.1 When 3.1 was heated to reflux in hexane, it was transformed into …

The Development Of Efficient Geminal-Based Methods For Quantum Chemical Calculations, Brett Allen Cagg

Theses and Dissertations

Incorporation of electron correlation to improve the accuracy of computations remains a driving force in quantum chemical method development. Traditionally, electron correlation effects are divided into static and dynamic correlation parts, and the inclusion of both results in methods that are impractical for large chemical systems. The goal of this doctoral research is to develop a method that efficiently accounts for both components of electron correlation in a separate but balanced manner. The approach focuses on combining a geminal method, called the antisymmetrized product of singlet-type, strongly orthogonal geminals (SSG), with dynamic correlation by either density functionals or a recently …

Avoiding Doubled Words In Strings Of Symbols, Michael Lane

Theses and Dissertations

A word on the n-letter alphabet is a finite length string of symbols formed from a set of n letters. A word is doubled if every letter that appears in the word appears at least twice. A word w avoids a word u if there is no non-erasing homomorphism h (a map that respects concatenation) such that h (u) is a subword of w. Finally, a word w is n-avoidable if there is an infinite list of words on the n-letter alphabet that avoid w. In 1906, Thue showed that the simplest doubled word, namely xx, is 3-avoidable. In 1984, …

Chemical Processes Governing The Equilibrium Between Organic And Inorganic Carbon: Probing The Mechanisms Of Iron Catalyzed Reactive Oxygen Species Production, Joy Kelechi Ihekweazu

Theses and Dissertations

This study examines the oxidation of organic carbon that occurs concurrently with the autoxidation of Fe(II) to determine the role that geochemical constituents have on both the autoxidation of Fe(II) and subsequent ROS production. The reaction between reduced carbon and oxygen is thermodynamically favorable, but kinetically proceeds slowly. Fe(II) facilitates the equilibration of reduced carbon and oxygen. This equilibration occurs naturally in saline estuaries, where oxygen rich seawater mixes with anoxic groundwater. We characterized a saline estuary at the Baruch Institute and used those characterizations to recreate natural water conditions in the lab. Using simulated natural water we then examined …

Modification Of Nanoparticles For Designed Interfaces, Tony Lee Neely, Jr.

Theses and Dissertations

The work contained herein, is focused on the design, synthesis, and characterization of polymer nanocomposite interfaces and the property enhancement afforded from said interface design. Through the use of reversible addition fragmentation chain transfer (RAFT) polymerization for the grafting of polymer chains to silica nanoparticles, the surface of silica nanoparticles can be manipulated to tune the properties of the nanocomposite as a whole.

In the first part of this work, heterogeneity is introduced onto the surface of silica nanoparticles via a sequential RAFT polymerization to afford a bimodal brush system. A densely grafted, short brush population is polymerized from the …

Illuminating The Interactions And Functions Of Glutaredoxins, Bola Proteins, And Erv1 In Iron Homeostasis, Adrian Colleen Dlouhy

Theses and Dissertations

Iron is a redox-active protein cofactor required for essential cellular functions such as respiration, however excess intracellular iron can generate damaging reactive oxygen species. Understanding how cells regulate iron levels is critical for treatment of human diseases that span from anemia to iron overload disorders. Glutaredoxins (Grxs) with a CGFS active site are highly conserved proteins shown to have roles in iron homeostasis and iron-sulfur cluster assembly, thus earning them the title “the Iron Whores”. They can exist either as a [2Fe-2S] cluster-bound dimer or an apo monomer, suggesting conservation of structure and function. In addition, Grxs interact with the …

The Role Of Intermembrane Space Redox Factors In Glutathione Metabolism And Intracellular Redox Equilibrium, Hatice Kubra Ozer

Theses and Dissertations

The mitochondrial intermembrane space (IMS) is a unique subcellular compartment that houses key thiol-dependent redox pathways such as protein transport, mitochondrial respiration, and detoxification of ROS (reactive oxygen species). These pathways are all dependent on cysteine-rich proteins, thus maintaining thiol-disulfide balance in this organelle is crucial for cellular functions. An IMS protein import pathway called the Mia40-Erv1 disulfide relay system uses disulfide bond formation for the import and retention of substrate proteins in the IMS. Erv1 is also suggested to be involved in maturation of cytosolic Fe-S cluster proteins and regulation of iron homeostasis in S. cerevisiae. However, these studies …