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Synthesis And Integration Of Oligoviologens Into Hydrogel Actuators, Kevin Liles

Arts & Sciences Graduate Student Theses and Dissertations

Interest in the development of soft-material artificial molecular muscles has inspired scientists to pursue novel stimuli-responsive systems capable of undergoing change in the physical and mechanical properties of a material in response to external stimuli. This interest has been driven primarily by advances, or the desire for advances, in fields such as soft robotics, microfluidics, and bio-compatible drug-delivery systems. In this work, redox-responsive viologens and their ability to form stable radical-cation complexes were evaluated as a method of actuation in stimuli-responsive materials, specifically hydrogels. First, a brief overview of hydrogel actuators is covered, with some examples given of the broad …

Canvass: A Crowd-Sourced, Natural-Product Screening Library For Exploring Biological Space, Sara E. Kearney, Gergely ZahoráNszky-KőHalmi, Kyle R. Brimacombe, Mark J. Henderson, Caitlin Lynch, Tongan Zhao, Kanny K. Wan, Zina Itkin, Christopher Dillon, Min Shen, Dorian M. Cheff, Tobie D. Lee, Danielle Bougie, Ken Cheng, Nathan P. Coussens, Dorjbal Dorjsuren, Richard T. Eastman, Ruili Huang, Michael J. Iannotti, Surendra Karavadhi, Carleen Klumpp-Thomas, Jacob S. Roth, Srilatha Sakamuru, Wei Sun, Steven A. Titus, Adam Yasgar, Ya-Qin Zhang, Jinghua Zhao, Rodrigo B. Andrade, M. Kevin Brown, Robert B. Grossman

Chemistry Faculty Publications

Natural products and their derivatives continue to be wellsprings of nascent therapeutic potential. However, many laboratories have limited resources for biological evaluation, leaving their previously isolated or synthesized compounds largely or completely untested. To address this issue, the Canvass library of natural products was assembled, in collaboration with academic and industry researchers, for quantitative high-throughput screening (qHTS) across a diverse set of cell-based and biochemical assays. Characterization of the library in terms of physicochemical properties, structural diversity, and similarity to compounds in publicly available libraries indicates that the Canvass library contains many structural elements in common with approved drugs. The …

Computational Studies Of Fullerene-Porphyrin Dyads, Sumreen Gul

Theses and Dissertations

Fullerene (C60) has generated much scientific interest since its discovery due to its novel optical, electronic, and physical properties. Fullerene has been shown to be an excellent electron acceptor and as a result is the acceptor of choice in organic photovoltaics. Porphyrins are excellent electron-donors due to their stability, low ionization potential, and excellent light absorption properties. As a result, fullerene-porphyrin dyads form unique donor-acceptor systems that can be useful for a variety of photoactive applications. In this research, computational studies have been performed on different varieties of C60-Porphyrin dyads and the relationship between molecular topology and the properties of …

Synthesis, Characterization And Enhanced Electrochemical Performance Of Amide-Based Metal Complexes As Electrocatalysts In Energy Devices And Non-Enzymatic Sensor, Charlette Parnell

Theses and Dissertations

The use of metal catalysts supported on the carbon nanomaterials as electrocatalysts has propelled the development of modified electrodes for electrochemical studies. They have been shown to increase sensitivity and electrical conductivity making them advantageous in applications for fuel cells, sensors and supercapacitors. In this dissertation, the synthesis and characterization of metal catalysts supported on carbon nanomaterials will be discussed and their electrochemical activity towards fuel cells, sensor and supercapacitor studies will be explored. Due to the great need for energy efficient and environmentally benign energy devices that can replace the use of fossil fuels in energy production, fuel cells …

H2 Oxidation Over Supported Au Nanoparticle Catalysts: Evidence For Heterolytic H2 Activation At The Metal-Support Interface, Todd N. Whittaker, K. B. Sravan Kumar, Christine Peterson, Meagan N. Pollock, L. C. Grabow, Bert D. Chandler

Chemistry Faculty Research

Water adsorbed at the metal-support interface (MSI) plays an important role in multiple reactions. Due to its importance in CO preferential oxidation (PrOx), we examined H₂ oxidation kinetics in the presence of water over Au/TiO₂ and Au/Al₂O₃ catalysts, reaching the following mechanistic conclusions: (i) O₂ activation follows a similar mechanism to that proposed in CO oxidation catalysis; (ii) weakly adsorbed H₂O is a strong reaction inhibitor; (iii) fast H₂ activation occurs at the MSI, and (iv) H₂ activation kinetics are inconsistent with traditional dissociative H₂ chemisorption on metals. Density …

Structure-Property Relationships Of Solvent-Cast Organic Thin Films For Model Corrosion Control Coatings, Austin Maples

Dissertations

This dissertation aimed at answering several fundamental questions, specifically: 1) What is the effect of scribing parameters on visual corrosion assessments? 2) What role do molecular weight, residual solvent, and polymer composition have on morphological changes in organic thin films? 3) What alternatives to visual assessments could be implemented to better understand and detect corrosion before macroscopic failure? This research definitively proved that scribes can vary in type and dimensions, and yet are still comparable if the scribe dimensions before exposure are known. Furthermore, it demonstrated that solvents common to a variety of coating industries could become trapped within the …

Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George

Chemistry & Biochemistry Faculty Works

High-order harmonic generation (HHG) in solids has entered a new phase of intensive research, with envisioned band-structure mapping on an ultrashort time scale. This partly benefits from a flurry of new HHG materials discovered, but so far has missed an important group. HHG in magnetic materials should have profound impact on future magnetic storage technology advances. Here we introduce and demonstrate HHG in ferromagnetic monolayers. We find that HHG carries spin information and sensitively depends on the relativistic spin–orbit coupling; and if they are dispersed into the crystal momentum k space, harmonics originating from real transitions can be k-resolved and …

Assessing Biofiltration Without Ozonation For Removal Of Trihalomethane Precursors In Drinking Water At The Beaver Water District Drinking Water Treatment Plant, Sana Ajaz

Graduate Theses and Dissertations

Biofiltration without pre-ozonation has the capability to remove natural organic matter (NOM) fractions that serve as precursors of disinfection byproducts (DBPs), which include the four regulated trihalomethanes (THMs) and dichloroacetonitrile (DCAN). Rapid small-scale column tests (RSSCTs) and Pilot Plant filters operated at empty-bed contact times (EBCTs) of 4, 8, and 16 minutes were used to evaluate the performance of nutrient-amended (free ammonia and phosphorus) biofiltration for THM and DCAN precursor removal, as measured using formation potential (FP) tests. NOM surrogates – which include dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA254) and fluorescence-PARAFAC components – were measured weekly throughout the …

Online Bioanalytical Mass Spectrometry Methods For Analysis Of Small And Large Biomolecules Using One- And Two-Dimensional Liquid Chromatography, Yehia Zakaria Baghdady

Chemistry & Biochemistry Dissertations - Archive

In recent years, the innovation in biomarkers and biotherapeutics has increased the demand for state-of-the-art analytical platforms to achieve reliable and accurate discoveries and quantitative analysis methods. The challenges in their determinations are not limited to the large number of small and large biomolecules but also involve the great heterogeneity in chemical properties and abundance of those analytes. Liquid chromatography and mass spectrometry have advanced significantly to be the most common platform for analyzing biological samples. However, there are still many unmet challenges that that require application of novel bioanalytical methods to fill many gaps in online sample preparation, chromatographic …

Fundamental Studies On Ultrafast Separations And Development Of Geopolymer Based Base-Stable Stationary Phase Media, Rasangi Madhumali Wimalasinghe K.K.D.G.

Chemistry & Biochemistry Dissertations - Archive

This thesis consists of two sections. In the first section fundamentals of ultrafast separations is discussed. Ultrafast chromatography is an emerging area of separation science due to its applicability in high-throughput separations and purifications. State of the art superficially porous particles packed short and ultrashort columns are utilized to obtain the amenable speed and chromatographic efficiency required in ultrafast chromatography. Modifications to state of the art HPLC and UHPLC instrumentation required in cases where ultrafast separations are needed. Sub-second liquid chromatographic separations and ultrafast separations of biomolecules and complex mixtures are demonstrated. Fundamentals behind the analytical chromatographic column packing are …

The Regional Distribution And Molecular Interactions Of Phospholipids And Glucose In Mammalian Vitreous Humors., Abigail Nicole Schnepf

Electronic Theses and Dissertations

The vitreous humor (VH) is located in between the lens and the retina. It is composed of 98% water, hyaluronan (HA), collagen, proteins, phospholipids (PLs), and other metabolites. With aging, the VH undergoes liquefaction, a process that causes the gel-like structure of the VH to turn into a liquid and can lead to serious ocular diseases, including retinal detachment, vitreal detachment, and macular hole formation. The liquefaction process is expedited in diabetic VHs. This project focuses on understanding the molecular changes that lead to liquefaction and the reasons for which this process is accelerated with diabetes. Matrix-assisted laser desorption ionization/mass …

Cigarette Litter Leachates: A Statistical Study Of Elements In Freshwater And Saltwater, Cintly Guzman Hernandez

Honors Theses

Cigarette butts are the most common item found in coastal litter cleanups as approximately 4.5 trillion smoked cigarette butts are discarded into the environment every year. Cigarette butts can leach toxic heavy metals and nicotine along with other compounds from tobacco combustion. Past research in our lab has analyzed elements leached from cigarette butts into freshwater. The cigarette butts consisted of smoked and unsmoked butts that were soaked varying periods of time, and at different pH levels to identify the relationship of these variables to the amount of metal leached. The elements analyzed were Al, Ba, Cd, Cr, Cu, Fe, …

Mechanistic Study Of The Inhibition Of Rho Gtpase-Mediated Metastasis, Hope Gloria Umutesi

Chemistry & Biochemistry Dissertations - Archive

The Ras superfamily of small GTPases are monomeric proteins that bind guanine nucleotides, and regulate many cellular signaling pathways. They function as molecular switches by shuttling between active GTP-bound and inactive GDP-bound states. The Ras superfamily consists of its subfamilies including Ras and Rho GTPases. Ras and Rho GTPases function to regulate cellular growth, transformation, transport, motility, traffic, and adhesion. Small GTPases reactions often require regulators, such as guanine nucleotide exchange factors (GEFs) and GTPase Activating Proteins (GAPs). GEFs mediate fast release of GDP and allow loading with GTP while GAPs accelerate the GTP hydrolysis to GDP. Redox agents also …

Development Of Highly Polar Structurally-Tuned Ionic Liquids With Unique Selectivity For Gas Chromatography, Mohsen Talebi

Chemistry & Biochemistry Dissertations - Archive

Ionic Liquids (ILs) are state-of-the-art fluids that have found broad application in separation science. Owing to their unique physicochemical properties such as low vapor pressure, high thermal stability, and high viscosity, they were successfully used as stationary phase in gas chromatography (GC). By properly engineering their molecular structure, ionic liquids with tailor-made properties can be designed. Therefore, a systematic structure-function relationship can be established to study the effect of structural modification on the properties of ionic liquids. Herein, I describe the design and synthesis of several dicationic ionic liquids. The synthesized ILs were characterized in terms their physicochemical properties. The …

The Characterization Of Leather Wwii Artifacts Using Gc/Ms And Raman Spectroscopy, Brice Houser

Fall 2018 - Chemical Analysis Class Projects

Many museums face the challenge of protecting artifacts from deterioration. This process is often hampered by the history of the artifact, which can introduce factors that start or speed up the process of deterioration. An example of this is the method used during WW II to preserve leather. Mink oil or other fatty substances are used to help preserve and soften leather. A major component of mink oil is palmitic acid.

1 This fatty acid may have reacted with the brass in the same way that the oils from the hand react with coins to make that distinctive metallic smell, …

Quantification Of Trigonellinefrom Coffee Beans And Its Correlation With The Ph, Kashif A. Shaikh, Jaspreet K. Rishi, Joshua Sebree

Fall 2018 - Chemical Analysis Class Projects

This project analyzed the amount of trigonelline preseent in coffee beans at various stages of the roasting process.

Vitamin E Promotes The Inverse Hexagonal Phase Via A Novel Mechanism Implications For Antioxidant Role, Paul Harper

University Faculty Publications and Creative Works

No abstract provided.

Heteroleptic Nickel Complexes Of A Bulky Bis(Carbene)Borate Ligand, Jorge L. Martinez, Wei-Tsung Less, Maren Pink, Chun-Hsing Chen, Jeremy M. Smith

Chemistry: Faculty Publications and Other Works

Bis(carbene)borate ligand transfer to the nickel nitrosyl synthon Ni(NO)(PPh3)2Br provides the new nickel nitrosyl complex Ph2B(t BuIm)2Ni(NO)(PPh3). The solid state structure reveals a trigonal pyramidal nickel ion with a very long bond to the apical PPh3 ligand. The complex reversibly dissociates PPh3 in solution to afford three‐coordinate Ph2B(t BuIm)2Ni(NO), with NMR data providing evidence for PPh3 binding at low temperatures. Ligand transfer to Ni(PMe3)2Cl2 provides the square planar complex, Ph2B(t BuIm)2Ni(PMe3)Cl, which shows no evidence for rearranging to the form a homoleptic complex with two bis(carbene)borate ligands. This complex is a suitable synthon for the [Ph2B(t BuIm)2Ni]+ fragment, as demonstrated …

Green Synthesis/Biosynthesis Of Silver Nanoparticles By Using Orange Peel Extract, Leela Joshi

Theses and Dissertations

Joshi, Leela, Green Synthesis/Biosynthesis of Silver Nanoparticles by Using Orange Peel Extract. Master of Science (MS), December, 2018, 40 pages, 23 figures, references, 36 titles. In this work, we report synthesis of silver nanoparticles (AgNPs) with an average size of ~6 nm. The aqueous solution of Ag+ ions is reduced using an aqueous extract from orange peel (Citrus Sinensis) at varying pHs. Reduction of Ag+ ions in solution was monitored using UV-visible absorption spectroscopy, and the corresponding surface plasmon resonance of AgNPs at 435 nm. The solution changed color from yellow to reddish-brown upon bioreduction of silver nitrate in orange …

Effects On Altering Reaction Conditions In Suzuki Cross Coupling Reactions Using The Microwave, Javier Alejandro Perez

Theses and Dissertations

Over the last few decades, Suzuki coupling has become a common process for the synthesis of intermediates in pharmaceutical and industrial applications. It is well known that palladium is an effective catalyst for the formation of cross-coupled products. Therefore, this catalyst was tested in a series of reactions. Also, it is believed that other catalyst with similar properties to palladium can work, for example cerium. Therefore, a cerium hydroxide catalyst was synthesized in lab and used as a potential catalyst for the Suzuki reaction. For this study, some bases were investigated (NaOH, Na2CO 3, K3PO4, NaNO3, NaHCO3, etc) for the …

1. Synthesis And Characterization Of A Vanadium Based Transition State Mimic For Organophosphate Hydrolase 2. Catalytic Oxidation Of Thioanisole And 2-Chloroethyl Ethyl Sulfide Using Resin Bead Supported Oxoperoxidovanadium(V) Complexes, Efram Goldberg

Theses and Dissertations

Two vanadium(V) complexes were prepared for different projects. First the ONS tridentate ligand 14 was prepared according to literature procedure. This ligand was chosen to make the ONS dioxovanadium complex 15 for conjugation to a protein and to eventually elicit catalytic antibodies for the hydrolysis of the chemical weapon VX. Complex 15 was prepared in 65% overall yield and a full characterization was performed including X-ray diffraction. Initial screening performed at the Naval Research Laboratory indicated an IC50 of 84 nM for inhibition of a bacterial cholinesterase. It was also found to be 50% as effective as the control antiobiotic …

Data On Spectrum-Based Fluorescence Resonance Energy Transfer Measurement Of E. Coli Multidrug Transporter Acrb, Yuguang Cai, Thomas E. Wilkop, Yinan Wei

Chemistry Faculty Publications

This paper presented the dataset of correction parameters used in the determination of the energy transfer efficiencies from the spectrum-based fluorescence resonance energy transfer (FRET) measurement in a trimeric membrane protein AcrB. The cyan fluorescent protein (CFP) and yellow fluorescent protein (YPet) were used as the donor and acceptor, respectively. Two AcrB fusion proteins were constructed, AcrB-CFP and AcrB-YPet. The proteins were co-expressed in Escherichia coli cells, and energy transfer efficiency were determined in live cells. To obtain reliable energy transfer data, a complete set of correction parameters need to be first determined to accommodate for factors such as background …

Computational Quantum Chemistry Studies Of The Interactions Of Amino Acids Side Chains With The Guanine Radical Cation., Edward Acheampong

Electronic Theses and Dissertations

Guanine is generally accepted as the most easily oxidized DNA base when cells are subjected to ionizing radiation, photoionization or photosensitization. At pH 7, the midpoint reduction potential is on the order of 0.2 – 0.3 V higher than those of the radicals of e.g. tyrosine, tryptophan cysteine and histidine, so that the radical “repair” (or at least, a thermodynamically favorable reaction) involving these amino acids is feasible. Computational quantum studies have been done on tyrosine, tryptophan, cysteine and histidine side chains as they appear in histones. Density functional theory was employed using B3LYP/6-31G+ (d, p) basis set to study …

Relative Permittivity As A Function Of Co-Solvent And Impedance Spectroscopy For Quantifying Anions In Solution, Yahya Sami Alseiha

Electronic Theses and Dissertations

This work measured relative permittivity from 15.0 to 55.0 °C of aqueous solutions containing acetone or tetrahydrofuran using a BI 870 dielectric meter. A cubic polynomial fit resulted in coefficients for calculating permittivity as a function of temperature and mole fraction. Literature values for other co-solvent system resulted in similar polynomial coefficients. Using BI 870, permittivity measurements of ionic solutions were not possible because of high conductivity. A simple method using impedance spectroscopy measured these solutions. Impedance decreases with increasing temperature and decreases with increasing ionic strength. Due to the temperature dependence of impedance, all measurements were at 25.0 °C. …

Extraction And Purification Of Biologically Active Metabolites From Rhodococcus Sp. Mtm3w5.2, Mohrah Alenazi

Electronic Theses and Dissertations

Rhodococcushas been recognized as a potential antibiotic producer. Recently, a strain of Rhodococcussp. MTM3W5.2 was isolated from a soil sample collected in Morristown, Tennessee and was found to produce an inhibitory compound which is active against other related species. The purpose of this research is to extract, purify and analyze the active metabolite. The compound was extracted from RM broth cultures and purified by preliminary fractionation of crude extract through a Sephadex LH-20 column. Further purification was completed using semi-preparative reversed phase column chromatography. Final purification was obtained using multiple rounds of an analytical C18 HPLC column. Based …

Molecular Dynamics Investigation Of The Thermodynamics Of Nanoscale Droplets And Kinetics Of Weakly Correlated Systems, Kai Yang Leong

Graduate Theses and Dissertations

The surface tension of nanoscale droplets of water was studied with molecular dynamics simulations using the BLYPSP-4F water potential. The internal pressure of the droplet was measured using a correlation between the pressure and density, established through a series of bulk simulations performed at pressures from 1 to 1000 bar. Such a procedure allows for reliable determination of internal pressure without the need to calculate the local Virial. The surface tension, estimated with the Young-Laplace relation, shows a good agreement with the Tolman equation with a Tolman length of -0.48 Å. The interface of a liquid water droplet is shown …

Investigation Of Electrolytic Flocculation For Microalga Scenedesmus Sp Using Aluminum And Graphite Electrodes, Shihong Liu, Husam A. Abu Hajar, Guy Riefler, Ben J. Stuart

Civil & Environmental Engineering Faculty Publications

Electrolytic flocculation using non-sacrificial electrodes with flocculants added was studied on harvesting Scenedesmus sp. In order to optimize the operating conditions of the electrolytic flocculation process and to quantify the amount of flocculants added, aluminum electrodes were first used in the process. It was found that under optimal conditions, the microalgae removal efficiency using aluminum electrodes could reach 98.5%, while 34.2 mg L^-1 of aluminum ions were released during the process. Different metal electrodes were also studied, but high microalgae removal efficiency was witnessed only using aluminum electrodes, indicating the influence of the aluminum ion in flocculation. When non-sacrificial …

Quantum Mechanical Studies Of N-H···N Hydrogen Bonding In Acetamide Derivatives And Amino Acids, Sandra J. Lundell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Proteins are made of vast chains of amino acids that twist and fold into intricate designs. These structures are held in place by networks of noncovalent interactions. One of these, the hydrogen bond, forms bridges between adjacent pieces of the protein chain and is one of the most important contributors to the shape and stability of proteins. Hydrogen bonds come in all shapes and sizes and a full understanding of these not only aids in our understanding of proteins in general but can bridge the gap to finding cures to many protein-related diseases, such as sickle-cell anemia. The primary aim …

Carbon Monoxide On Demand: Light-Induced Co Release Of Flavonols, Stacey N. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carbon monoxide (CO) is an extremely useful molecule with applications in industrial manufacturing, synthetic procedures as a C1 building block, and as a potential pharmaceutical to produce anti-inflammatory effects and vasodilation. However, the toxicity associated with CO has prevented its full utilization. In order to safely handle CO, compounds and molecules have been developed that act as storage materials for the gas. Ideal storage platforms only release CO upon stimulation via a trigger. Light activation is the most desirable trigger as it can be regulated in terms of the intensity and the wavelength of light used. The majority of light-induced …

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 …