Physical Sciences and Mathematics Commons^™

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …

A Stereospecific Pd-Catalyzed Suzuki Cross-Coupling Reaction And A Statistical Study Of The Ligand's Role In Stereoselection, Shibin Zhao

Dissertations, Theses, and Capstone Projects

The development of palladium-catalyzed carbon-carbon cross-coupling reactions has profoundly influenced the manner through which we approach the synthesis of complex organic molecules. Among established cross-coupling reactions, which include Kumada, Negishi, and Stille reactions, the Suzuki cross-coupling reaction exhibits particularly wide functional group compatibility, while employing non-toxic, air-stable organoboron nucleophiles. Conventional studies of Pd-catalyzed Suzuki cross-coupling reactions have focused on C(sp²)-C(sp²) cross-coupling reactions, which result in the formation of planar products. Conceptually, the use of C(sp³) (secondary) nucleophiles would enable the reliable manipulation of organic molecules in three dimensions. However, this process has not been …

Design And Synthesis Of Circadian Clock Modulators And The Study Of Lov Domain Protein Lkp2 In Arabidosis Thaliana And Brassica Rapa, Aditi Nagar

Chemistry Theses and Dissertations

Circadian rhythms are self-autonomous endogenous clocks synchronized with the rotation of the Earth. With the Earth’s rotation and revolution on its axis, the internal clock undergoes oscillation in the period of ~24 hour and governs day to day activities in most organisms. In humans, it regulates the day to day physiological activities. Today’s modern lifestyle has an impact on health: shift work, jet lag, and irregular eating habits contribute to the misalignment of the endogenous circadian oscillator, thereby, increasing the risk of many metabolic disorders including diabetes, irregular blood pressure, sleep disorders, obesity, depression, and cancer. The primary goal of …

Steric Effects Of Alkyl Ammonium Salts On The Combustion Of Exchanged Smectite Clays, Celeste A. Keith

Electronic Theses and Dissertations

Bomb calorimetry was explored as a new method for determining the cation exchange capacity (CEC) of clays. Smectite clays were modified with several alkyl ammonium salts varying in number of carbons and the spatial orientation of the carbons about the central nitrogen atom. The clays used, standards purchased from the Source Clay Repository, have CECs of 44, 80, 88, and 120 meq/100 g. Theoretically, the combustion energy of the organo-clays should be approximately the same for each salt. Any differences in energy would be due to the different structures of the salts and how they are oriented in the interlamellar …

Advances In Local Vibrational Mode Theory And Unified Reaction Valley Approach (Urva), Yunwen Tao

Chemistry Theses and Dissertations

Since the establishment of the Local Vibrational Mode Theory and the Unified Reaction Valley Approach (URVA), these two research pillars have been pushed forward in the CATCO group and played an important role in (i) characterizing the chemical bonds in molecules and (ii) molecular chemical reactions. This dissertation elaborates my contributions to the Local Vibrational Mode Theory and the Unified Reaction Valley Approach (URVA).

We have applied the Local Vibrational Mode Theory to hydrogen bonding in liquid water and proposed an explanation for the Mpemba effect. We explored and discovered new directions of applying local vibrational modes majorly in characterizing …

Multi-Reference Systems In Chemistry; Unconventional Bonding In Organic Chemistry; Covalent Bonding In Transition Metal Clusters, Alan Wilfred Humason

Chemistry Theses and Dissertations

The geometries, chemical properties, and reactivities of molecules are determined by their electronic structure. The field of ab initio computational chemistry works to calculate the kinetic and potential energies between the nuclei and electrons of a molecule. These calculations usually begin with the determination the electronic ground state.

Molecules that cannot be adequately described with a single, ground state configuration are called \textit{multi-reference systems}, which require the calculation of a linear combination of all pertinent electronic configurations, with a corresponding increase in computational cost. This is not `black box' methodology, because solving these systems requires a good understanding of the …

Breaking The Language Barrier: Equitable Assessment In General Chemistry, Eshani Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Because language provides the framework through which knowledge is constructed, it is crucial to consider the ways in which students with limited English proficiencies are able to express their understanding. English language learners (ELLs) make up a significant portion of the student body in the education system and represent many ethnic and racial minorities in STEM (Science, Technology, Engineering & Mathematics) fields (Burke & Mattis, 2007). Despite the national push to build a more diversified, STEM-ready workforce, there is little research that considers the way ELLs are assessed in STEM courses at the postsecondary level. Literature reports that science tests …

Synthesis Of A Silsesquioxane Based Supramolecular Polymer, Rachel Bianculli

Honors Projects

Research toward smart materials, specifically self-healing polymers, is an expanding topic within the materials science field. These materials rely heavily on dynamic crosslinking that is achieved by inducing different degrees of hydrogen bonding, van der Waals forces, etc. This work, demonstrated by research previously done within the Ostrowski research group, shows how coordination bonds of transition metals have been shown to create light activated, self-healing properties. Work done with these light-activated chromium (III) complexes with a poly(butylyene-co-ethylene) backbone have shown how metal—ligand coordination geometries can tune mechanical properties of the polymeric material. However, these materials suffer from being incredibly soft …

Assessment Of Catalytic Function Of Gold Nanorod-Bound Tempo Under Nir Irradiation, Kristi L. St. Clair

Honors College Theses

Gold nanoparticles are of interest to a number of fields due to their size-dependent optical properties, high stability, and large surface area. The combination of these properties allows for a variety of uses including photothermal therapy, drug delivery and catalysis. Gold nanorods (GNR) absorb light of a given wavelength which stimulates the oscillation of electrons on the surface and is known as the surface plasmon resonance effect. The localized heating of rods via irradiation may cause enhanced effectiveness of an attached organic catalyst which allows the oxidation of alcohols to occur at room temperature. Previously, similar catalytic systems required high …

Steric Effects On The Formation Of Manganese Oxide Clusters And 2-Dimensional Ammonium Formate Architectures, Carl Oberle

Dissertations

It has been demonstrated by the Beatty group that altering the identity of the ortho-substituent of a dianiline counterion affects the assembly and dimensionality of a cadmium-chloride layer from 2-D to 0-D. This work seeks to extend this finding to metal oxide and organic hydrogen-bonded materials. By systematically increasing the ortho­-substituent’s size on the benzoate building block of reported manganese oxide clusters, of formula Mn_xO_y(O₂C-R)_zL_w (where R = Alkyl, L = neutral monodentate ligand), we aim to impact the self-assembly of these materials relative to their parent …

From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson

Nanoscience and Microsystems ETDs

Semiconducting nanocrystals, also known as quantum dots (QDs), that emit light with near-unity quantum yield and are extremely photostable are attractive options as down-conversion and direct electricity-to-light materials for a variety of applications including solid-state lighting, display technologies, bio-imaging and optical tracking. Standard QDs with a core/thin shell structure display fluorescence intermittency (blinking) and photobleaching when exposed to prolonged room temperature excitation for single dot measurements, as well as significant reabsorption and energy transfer when densely packed into polymers or at high solution concentrations.

We have developed thick shell “giant” QDs (gQDs), ultra-stable photon sources both at the ensemble and …

Combined Theoretical And Experimental Investigation Of Hydrogen Production Catalysis, Carolyn Noelle Virca

Dissertations and Theses

The widespread use of solar energy has been limited in part by the issue of effective storage. Water splitting is a means of converting solar energy into chemical fuel, in the form of hydrogen gas. It can be performed through both photochemical and electrochemical processes, via the two half reactions of water oxidation and proton reduction. Electrochemically, the catalyst receives electrons from an external circuit, which can be coupled to a renewable source such as a solar cell. Photochemically, a light-absorbing molecule provides an excited electron to a catalyst, which either generates oxygen or hydrogen gas. The work described herein …

The Preparation Of Diaryliodonium Salts For Application In Arylation Chemistry, Thomas Ludwig Seidl

Dissertations and Theses

Diaryliodonium salts offer potential as novel reagents for arylation chemistry. An overall goal and successful outcome of this work has been to further understanding of diaryliodonium salt chemistry by developing practical methods that enable chemists more convenient access to these reagents, for the purpose of reaction development. To this end a robust and convenient preparation method has been developed and resulted in novel commercially available diaryliodonium salts. The remainder of the work described, has focused on understanding the parameters important to diaryliodonium mediated arylation and has resulted in a solid framework that multiple future development efforts can build upon.

A …

Making Soap Green, Asia Sweet

Thinking Matters Symposium Archive

The One Gallon Soap Company (OGSC) recycles partially used bar soap from local Portland hotels and repurposes it as liquid hand soap. The preliminary formulations originally prepared by the OGSC produced a smooth, homogeneous liquid soap with good foaming action. However, over short and often variable time periods, the soap would separate into two layers: a watery bottom layer with little foaming action and an oily top layer. The OGSC asked the USM Chemistry Department to investigate the formulation process in an effort to provide a more stable product – one that would maintain a constant consistency over several months.

Organocatalyzed Synthesis Of Epoxides From Chalcones Utilizing Amino Acids, Sabrina N. Kegeler

Masters Theses

The epoxide functional group is important throughout the chemical and pharmaceutical industries, as well as in nature. In the chemical industry, epoxides are present in resins and fragrances. In the pharmaceutical industry, epoxide-containing compounds are used as intermediates in the manufacturing of drugs. In nature, many natural products contain epoxide groups and are used for medicinal purposes, and for models to create synthetic molecules.

One approach to epoxide synthesis involves the use of an alkene precursor, a base, and an oxidizing agent. This is where my investigations began. The first step was to optimize the epoxidation reaction, examining substrate scope, …

Comparison Of Processed And Non-Processed Biomass Digestion, Richard Bruce Clark Iii

Graduate Theses - Chemistry and Biochemistry

Lignocellulosic ethanol is the main focus of second-generation biofuels [1]. Because cellulose is the most abundant organic material on earth, second-generation biofuels are a more sustainable option than the classical first-generation biofuels that use foodstuffs as the main feedstock in ethanol production [1]. Furthermore, biofuel can be produced not only from unprocessed biomass such as corn husks but also from processed material like paper [1]. Ionic liquids have shown to be quite effective in dissolving naturally occurring, and traditionally insoluble, polymers such as cellulose into solution, and cellulase enzymes have been shown to effectively digest cellulose into simple sugars [2]. …

A Comprehensive Analysis Of Aromatic-Proton Mediated Hydrogen Bonds, Mona S. Alshamrani

Electronic Theses and Dissertations

Hydrogen bonds play critical role in folding, structure and recognition of biological macromolecules (e.g., proteins, RNA, DNA). In addition to classical hydrogen bonds (e.g., ─OH---O=, ─OH---O─, ─NH---O─ etc.), structural analysis of protein and nucleic acids, almost a decade ago, showed that hydrogen bonds (e.g., CH---O) with hydrogen atoms on aliphatic carbon atoms (hereafter, aliphatic-protons) also play very important role in the structure and function of biomolecules. Even though, protons of aromatic ring systems (hereafter, aromatic-protons) are more polar than the aliphatic-protons, systematic analysis of hydrogen bonds of aromatic-protons have not been carried out. Therefore, I carried out a systematic analysis …

Development Of Bioanalytical Methods For Quantitative Measurement Of Anticancer Agents, Sandeep R. Kunati

ETD Archive

The ever-growing need to develop new anticancer agents due to increased incidence of cancer and its recurrence has led to a broad range of investigational efforts in anticancer research. Drug discovery and development processes involve evaluations of pharmacokinetic and pharmacodynamic parameters of potential drug candidates in order to assess their safety, toxicity, and efficacy profiles. By providing sensitivity, assay precision, reliability, and high-throughput, mass spectrometry has become an indispensable tool in quantitative and qualitative analysis, from early-stage drug discovery and development processes to routine laboratory analysis. Development of bioanalytical methods requires knowledge of separation science with instrumentation, data interpretation and …

Biomimetic Macromolecules For Macrophage Targeting And Modulation, Joshua Whited

ETD Archive

Carbohydrate recognition has come to the forefront of biological aiming to uncover the mechanisms of physiological and pathological processes. Cell surface glycans are involved in processes including cellular adhesion, cell signaling, and immune response. A new approach for profiling cell surface glycans has great potential for a wide range of biomedical applications. Lectins have been conventionally used to determine the structure and function of glycoproteins, however, their numbers are still restricted compared to the number of glycan structures. Boronic acid has proven a remarkable small molecule capable of binding diols in aqueous solution. This interaction indicates boronic acid derived molecules …

Synthesis And Biological Evaluation Of Small Molecular Drug Candidates For The Treatment Of Her2 Overexpressed Breast Cancer, Anran Zhao

ETD Archive

In the US breast cancer is the most common cancer after skin cancer. Currently in the US the average risk of a woman to develop breast cancer in her life is roughly 12%. About 25-30% of breast cancer patients have HER2 overexpressed tumor, and the growth of tumor cell is depend on HER2 pathway. It has been well-documented that patients with over-expressed HER2 are associated with increased disease recurrence, worse prognosis and lower survival. Currently there are two type of HER2 targeting drug. The first group is HER2 monoclonal antibody drugs such as trastuzumab approved by FDA in 1998; the …

Quantitative Analysis Of Bleomycin In Rat Plasma By Lc-Ms/Ms, Huawen Li

ETD Archive

Bleomycin is the most commonly used compound in its group of antineoplastic drugs. It works on tumor cells by single and double stranded DNA cleavage after its activation, in which it blocks tumor cells’ DNA replication or transcription activities to inhibit tumor cells’ growth. Bleomycin sulfate (Blenoxane) is the most popular preparation used in clinical research, and contains Bleomycin fractions of A2 and B2, which causes difficulties in quantitative analysis. This work uses the metal chelating property of Bleomycin as an advantage to simplify and improve sensitivity of existing quantitative methods. Copper was spiked in excess to plasma samples, followed …

Computational Investigation Of Protein Assemblies, Sm Bargeen Alam Turzo

ETD Archive

Selective nitrosylation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) at Cys-247 affects gene regulation through the interferon-gamma (IFN- γ) activated inhibitor of translation (GAIT) complex. Oxidized low-density lipoprotein (LDL_ox) and INF-γ induce assembly of the nitrosylase complex composed of inducible nitric oxide synthase (iNOS), S100A8, and S100A9 proteins. Crystal structure of the complex of GAPDH and S100A8A9 is not known, structural prediction method were employed by protein-protein docking and binding energy calculation with PatchDock and FIREDock respectively. Candidate models were selected, based on a weight factor calculated, from the computational method developed from the "artificial protease" cleavage mapping Fe(III) (s)-1-(p- …

Oxidation Of Ferrocene Derivatives With Dibenzoyl Peroxide And Meta-Chloroperoxybenzoic Acid, Jos M. Halstead

ETD Archive

The chemical oxidation of ferrocene and related derivatives (RFc) via organic peroxides solvated in acetonitrile was studied spectrophotometrically by varying concentration and temperature to determine kinetics and activation parameters. The reaction rate of ferrocene with dibenzoyl peroxide depends strongly on whether electron withdrawing or donating substituents are present. Products were analyzed and the effect of different solvents on reactivity were studied. The rate law was first order in both oxidant and reductant, and steric and solvent effects are consistent with outer sphere electron transfer (ET) as the rate-controlling step. B3YLP calculations were conducted to determine reorganization energies using Marcus theory …

Model Chemistry Study Of Choline And Urea Based Deep Eutectic Solvents, Libby Nicole Kellat

ETD Archive

Gaussian and GaussView software were utilized to characterize interactions between choline salts and urea, which form a deep eutectic solvent (DES). The initial system studied was choline chloride and urea, at a 1:2 molar ratio, which is also known as reline. Subsequent systems, substituting the chloride anion with other anions (fluoride, bromide, and hydroxide), were studied to show that the system with greater calculated strength of interaction will have more non-ideal physical properties, such as melting point (found in literature). Observations regarding structure related to counterion electron density and hydrogen bonding were made throughout the studies.

Il-17 Drives Copper Uptake And Activation Of Growth Pathways In Colorectal Cancer Cells In A Steap4-Dependent Manner, Evan Martin

ETD Archive

Colorectal cancer is a disease characterized by abnormal, invasive cell growth beginning in the colon or rectum. The third most common type of cancer worldwide, approximately one million new cases of the disease are diagnosed across the globe annually, resulting in an estimated 700,000+ deaths. One major risk factor associated with development of colorectal cancer is the presence of chronic inflammation in the large intestine, also known as colitis. Inflammation is a complex immune response against harmful stimuli, characterized by symptoms including heat, redness, swelling and pain. One important molecular mediator of this process is interleukin 17 (IL-17), a pro-inflammatory …

Il-17 Drives Copper Uptake And Activation Of Growth Pathways In Colorectal Cancer Cells In A Steap4-Dependent Manner, Evan Martin

ETD Archive

Colorectal cancer is a disease characterized by abnormal, invasive cell growth beginning in the colon or rectum. The third most common type of cancer worldwide, approximately one million new cases of the disease are diagnosed across the globe annually, resulting in an estimated 700,000+ deaths. One major risk factor associated with development of colorectal cancer is the presence of chronic inflammation in the large intestine, also known as colitis. Inflammation is a complex immune response against harmful stimuli, characterized by symptoms including heat, redness, swelling and pain. One important molecular mediator of this process is interleukin 17 (IL-17), a pro-inflammatory …

Analysis Of Oxidation Of Carbon Monoxide On Rh (110), Razan Tanbour

Senior Honors Theses and Projects

81% of all rhodium (Rh) is used in automobile catalytic converters. Consequently, researchers have dedicated a lot of effort into understanding the behavior of nonmetal oxides on a Rh surface. Using a computer simulation program, we have studied the absorption and oxidation of carbon monoxide (CO) on a terraced Rh surface (lattice) with a width of three and a height of 10000 using a mechanism that describes the behavior at low temperatures. Varying the reaction activation energies (rate constants), and the mobility of the CO, led to changes in the surface coverages of oxygen and CO. Specifically, increasing the activation …

Oil Dries: A New Absorbent Material For Collection Of Ignitable Liquids From Semi-Porous Material, Jessica Sosa

Online Theses and Dissertations

Extraction of an ignitable liquid sample from a semi-porous surface such as concrete is especially difficult. For this purpose, two different solid oil dry absorbent materials, Instazorb and MAXXAbsorb, were researched for use of collection of ignitable liquid samples at a fire scene. These oil dries were spiked with different ignitable liquids (Coleman fuel, gasoline, kerosene, and diesel). Isolation of the ignitable liquid from the oil dry absorbent was accomplished by passive headspace isolation. Data was obtained by gas chromatography coupled with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Chromatograms obtained from both oil dries …

The Synthesis Of Highly Substituted Aromatics And The Reaction Of Alkene Pi Systems With Vinyl Cations, Nicholas Jarrod Dodge

Graduate College Dissertations and Theses

Aldol cyclotrimerizations have been used to achieve the rational chemical synthesis of both fullerenes and fullerene fragments in the past. Under certain conditions this reaction produces the corresponding cyclotetramer which has sometimes been regarded as an undesired byproduct. This work details efforts to synthesize and use these cyclotetramers toward a synthesis of a C240 fullerene fragment. One principal focus in this work is tridecacyclene, a cyclic tetramer of acenaphthylene given its name by our group for its thirteen rings. Relatively low yields for the synthesis of tridecacyclene and its derivatives drove us to investigate the mechanism of its formation and …

Differentiation Of Potential False Positives From Human Saliva Using Raman Spectroscopy For Forensic Purposes, Selina Casadei

Legacy Theses & Dissertations (2009 - 2024)

Traces of body fluids can be found at a crime scene. Being able to identify and differentiate the body fluids while preserving DNA is fundamentally important for forensic applications. Saliva is an important body fluid that can be found on bite marks, cigarette butts, and more, being an excellent source for DNA extraction. Current tests for saliva and other body fluids are destructive and body fluid specific, and are prone to false positives. Our laboratory has developed a universal method for identification of all main body fluids; saliva, semen, sweat, peripheral blood, and vaginal fluid, using Raman spectroscopy combined with …