Chemistry Commons^™

Water In The Computer Lab! (A Computational Project For Undergraduate Inorganic Chemistry), Bradley M. Wile, Trilisa M. Perrine

Chemistry and Biochemistry Faculty Scholarship

No abstract provided.

Thin Films Cds/Cdte Diodes For Nuclear Radiation Detection, Julianna Calkins, John Murphy, Lindsey Smith, Israel Mejia, Bruce Gnade, Manuel Quevedo-Lopez

Undergraduate Research Conference

No abstract provided.

High Level Protein Expression Slows Down Rate Of Growth Of Bacterial Broth Cultures, Saad Chaudhry, Kenechukwu Ekwemalor, Shobhit Keswani, Odutayo Odunuge

Undergraduate Research Conference

No abstract provided.

Determination Of Anions In Lanana Creek By Ion Chromatography, Tania Benavides

Undergraduate Research Conference

Abstract

Lanana Creek is one of two springs that surround Nacogdoches, TX. Lanana Creek starts southwest of Lake Naconiche, conjoining with several other bodies of water along its path, and becomes part of the Angelina River. This body of water eventually ends in the Gulf of Mexico which may contribute to the dead zone. Contaminants in water may be of small concentration; however, prolonged exposure could produce many negative effects. To prevent further contamination, the source of the contamination must be identified through testing the water for contaminants. Some possible sources of contamination may be from fertilizers and pesticides used …

Antibacterial Activity Of Biotransformation Product: 1s-(2-Benzfuranyl)-Ethanol, Amey Gonzalez, Marianne Burnett, Michele Harris

Undergraduate Research Conference

No abstract provided.

Characterization Of Proteins Involved In Biotransformation, Jasmine Moreland, Amey Gonzalez, Marianne Burnett, Michele Harris

Undergraduate Research Conference

No abstract provided.

Laboratory Evaluation Of Black Carbon Deposition Onto Snow And Transport Via Snowmelt, Larry D. Hermanson, Joshua P. Schwarz

STAR Program Research Presentations

Black carbon (BC) is an aerosol material produced by incomplete combustion of fossil fuels and biomass. BC has been shown to be the second most important anthropogenic climate warming agent after carbon dioxide due to its ability to absorb solar radiation, influence cloud behavior, and accelerate snow melt. BC in otherwise clean snow can significantly reduce its reflectivity. In order to learn about the significance of BC contamination in snow, we explored the deposition of BC onto snow and the transport of BC in snow during snowmelt. A Single Particle Soot Photometer (SP2), was used to measure the concentration and …

Determining Force Field Parameters Involved With Metal Organic Framework Synthesis, Marcus A. Tubbs, David Cantu, Vanda Glezakou

STAR Program Research Presentations

Metal organic frameworks (MOFs) are synthetic materials made of a cage-like lattice with consistently spaced pores. The size of these pores are the defining characteristic of a MOF, as it determines which gases are allowed to pass through and which can be trapped. Examples of their potential use can be greenhouse gas sequestration or storage. Currently, the synthesis of MOFs is based on trial-and-error, and the successes are not well understood. We are working on building the theoretical framework that describes how a particular MOF, MIL-101, comes together during synthesis. Our initial approach was to simulate the possible reactions with …

Characterization Of Organic Carbon In Sediments From Old Rifle, Co, A Former Uranium Mill, Francis Michael Tee, Morris Jones, Sharon Bone, Michael Schaefer, Scott Fendorf, John Bargar

STAR Program Research Presentations

Characterization of sediments from Old Rifle, CO, a former uranium mill

More than 34 million gallons (~129 million liters) of groundwater are contaminated with uranium at Old Rifle, Colorado – a former uranium-processing site that operated until 1958. The original Department of Energy strategy for remediation, involving natural flushing of U from the groundwater through mixing with surface water, has not been as successful as predicted. The uranium plume is replenished when insoluble U(IV) is oxidized to the more mobile U(VI). Relatively thin pockets of silt-, clay-, and organic-rich sediments contain reduced uranium, iron and sulfur and are referred to …

Exploring Soil Moisture Protocol Alternatives For The Classroom Setting, Garrett Smith

STAR Program Research Presentations

Climate change poses a direct threat to future water resources but current climate models suffer from uncertainties regarding the availability of regional water. SMAP or the Soil Moisture Active Passive mission seeks to make improvements to climate models by taking highly accurate, high resolution measurements of global soil moisture. To engage students around the world in a collection of meaningful data that may support the SMAP satellite mission, the Global Learning and Observations to Benefit the Environment program or GLOBE, has forged a partnership with NASA and JPL. GLOBE brings the power of citizen science to the SMAP mission, empowering …

Does A Plastron Improve Heat Transfer?, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Superamphiphobic surfaces strongly repel both water and oils. In this work, aluminum coupons are processed by sanding with various grit of sand paper to impart microscale roughness. Subsequent submersion of the aluminum substrate in boiling water grows nanoscale grass-like structures. The oxide layer of Al is slightly soluble in water. During a fast diffusion/equilibrium, Al₂O₃ nanograss grows on the surface. A low energy coating is then deposited on the surface. The micro and nanoscale features create re-entrant structures that trap air enabling contact liquid to be in a Cassie-Baxter state. Superamphiphobicity of the samples were confirmed by …

Antimicrobial Nanoparticles: A Green And Novel Approach For Enhancing Bactericidal Efficacy Of Commercial Antibiotics, Monic Shah

Masters Theses & Specialist Projects

On the verge of entering the post-antibiotic era, numerous efforts are in place to regain the waning charm of antibiotics which are proving ineffective against most “Superbugs”. Engineered nanomaterials, especially gold nanoparticles (GNPs) capped with antibacterial agents, are proving to be an effective and novel strategy against multidrug resistant (MDR) bacteria. In this study, we report a one-step synthesis of antibioticcapped GNPs (25 ± 5 nm) utilizing the combined reducing and capping ability of a cephalosporin antibiotic, ceftazidime. No signs of aggregation or leaching of ceftazidime from GNP surface was observed upon its storage. Antibacterial testing showed dosedependent broad spectrum …

Green Synthesis And Evaluation Of Catalytic Activity Of Sugar Capped Gold Nanoparticles, Yogesh A. Kherde

Masters Theses & Specialist Projects

Owing to the importance of gold nanoparticles in catalysis, designing of them has become a major focus of the researchers. Most of the current methods available for the synthesis of gold nanoaprticles (GNPs) suffer from the challenges of polydispersity, stability and use of toxic and harmful chemicals. To overcome these limitations of conventional methods, in our present study, we made an attempt to design a method for the green synthesis of monodispersed and stable gold nanoparticles by sugars which act as reducing and stabilizing agent. Characterization of synthesized nanoparticles was done by using various analytical techniques such as transmission electron …

Selective Oxidations By Iron(Iii) Porphyrins And Iron(Iii) Corroles, Aaron Dalnamath Carver

Masters Theses & Specialist Projects

The selective oxidation of organic compounds represents a leading technology for chemical industries. They are used in chemical synthesis in the pharmaceutical and petrochemicals industries, and possible the decontamination of harmful substances. However, oxidations reaction are among the most challenging processes to control. Many stoichiometric oxidants with heavy metals are expensive, or toxic maybe both, and therefore unfeasible to be utilized. The ideal processes for catalytic oxidation would use molecular oxygen or hydrogen peroxide as the primary oxygen source, with transition metal catalysts to mimic the predominant oxidation catalysts in Nature, the cytochrome P450 enzymes. This study focuses on the …

Electron Paramagnetic Resonance Imaging And Probes, Hanan B. Elajaili

Electronic Theses and Dissertations

EPR imaging at low frequency is an important method to measure in vivo physiology. Because native paramagnetic species exist at low concentrations in living systems, exogenous paramagnetic species are needed for in vivo EPR. Selection of the appropriate EPR probe allows the experimenter to obtain information about the environment of the imaged probe and its spatial distribution. Relaxation times for several nitroxide radicals were studied with the aim of understanding the relaxation mechanisms, which provides criteria for design of suitable in vivo imaging probes.

Amino-substituted trityl radicals have the potential to monitor pH in vivo, and the suitability for this …

Isotropic Oscillator Under A Magnetic And Spatially Varying Electric Field, David L. Frost Mr., Frank Hagelberg

Undergraduate Honors Theses

We investigate the energy levels of a particle confined in the isotropic oscillator potential with a magnetic and spatially varying electric field. Here we are able to exactly solve the Schrodinger equation, using matrix methods, for the first excited states. To this end we find that the spatial gradient of the electric field acts as a magnetic field in certain circumstances. Here we present the changes in the energy levels as functions of the electric field, and other parameters.

Synthesis And Antimicrobial Activity Of Brominated Quaternary Ammonium Compounds, Wendy Pippin

Honors Capstones

No abstract provided.

Ice Caves On Extraterrestrial Bodies: What Are The Prospects For Speleogenesis And Detection?, Penelope J. Boston

The International Workshop on Ice Caves

Potential mechanisms for creating cavities in icy extraterrestrial bodies have been tentatively explored by several authors. On one hand we have examples of mechanisms that create caves in water ice here on Earth. In addition, there may be unique mechanisms on other Solar System objects that do not occur on Earth but might produce cavities, e.g. sublimation of comets upon perihelion passage. The methods of detecting such cavities depend upon the nature of the icy body in question, the potential for orbital or landed missions to visit those bodies in the future, and remote or landed methods for detecting the …

Theoretical/Experimental Comparison Of Deep Tunneling Decay Of Quasi-Bound H(D)Oco To H(D) + Co₂, Albert F. Wagner, Richard Dawes, Robert Continetti, Hua Guo

Chemistry Faculty Research & Creative Works

The measured H(D)OCO survival fractions of the photoelectron-photofragment coincidence experiments by the Continetti group are qualitatively reproduced by tunneling calculations to H(D) + CO₂ on several recent ab initio potential energy surfaces for the HOCO system. the tunneling calculations involve effective one-dimensional barriers based on steepest descent paths computed on each potential energy surface. the resulting tunneling probabilities are converted into H(D)OCO survival fractions using a model developed by the Continetti group in which every oscillation of the H(D)-OCO stretch provides an opportunity to tunnel. Four different potential energy surfaces are examined with the best qualitative agreement with experiment …

A Novel Dual Allosteric Activation Mechanism Of Escherichia Coli Adp-Glucose Pyrophosphorylase: The Role Of Pyruvate, Matías D. Asención Diez, Mabel C. Aleanzi, Alberto A. Iglesias, Miguel Ballicora

Chemistry: Faculty Publications and Other Works

Fructose-1,6-bisphosphate activates ADP-glucose pyrophosphorylase and the synthesis of glycogen in Escherichia coli. Here, we show that although pyruvate is a weak activator by itself, it synergically enhances the fructose-1,6-bisphosphate activation. They increase the enzyme affinity for each other, and the combination increases Vmax, substrate apparent affinity, and decreases AMP inhibition. Our results indicate that there are two distinct interacting allosteric sites for activation. Hence, pyruvate modulates E. coli glycogen metabolism by orchestrating a functional network of allosteric regulators. We postulate that this novel dual activator mechanism increases the evolvability of ADP-glucose pyrophosphorylase and its related metabolic control.

Self-Assembly Of Gold Nanosphere Dimers By Inertial Force, George Andrew Christopher Sakhel

Graduate Theses and Dissertations

The morphology and composition of a nanoparticle (NP) play a critical role in determining the NP's properties and function. To date, researchers have created a myriad of NPs of different shapes, sizes, and compositions with interesting attributes and applications ushering a revolution in medicine, electronics, microscopy, and microfluidics.

In this study, gold (Au) nanosphere dimers (NSDs) have been synthesized through a novel self-assembly method. These particles were created from Au NPs mono-dispersed in aqueous solution via a process of centrifugation and capping agent replacement. Au NSDs consist of two Au NPs combined together with minimal gaps between them. Optical spectral …

Testing Predicted Specificity Determinants In The Dihydrofolate Reductase Enzyme Family, Seema J. Patel

Theses, Dissertations and Culminating Projects

Dihydrofolate Reductase (DHFR) is an essential enzyme for most organisms, ranging from bacteria to humans. DHFR has essential functions in DNA biosynthesis and cell replication; as a result, cell growth can be inhibited by the inhibition of DHFR. Evaluating the use of well-known DHFR inhibitors is becoming essential in treating infections in the developing world as DHFR is a known target of antibacterial and antiparasitic drugs. Understanding determinants of DHFR inhibitor specificity in terms of amino acid sequence and structure will allow repurposing or designing of new compounds that selectively target DHFR from the pathogenic organism of interest over the …

Cryoprotective Effect Of L-Carnitine On Motility, Vitality And Dna Oxidation Of Human Spermatozoa, S. Banihani, A. Agarwal, R. Sharma, Mekki Bayachou

Chemistry Faculty Publications

Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l-carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l-carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l-carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l-carnitine concentration in each cryovial was 0.5 …

Phosphorous Acid Route Synthesis Of Iron Tavorite Phases, Lifepo₄(Oh)ₓf₁₋ₓ [0 ≤ X ≤ 1] And Comparative Study Of Their Electrochemical Activities, Hooman Yaghoobnejad Asl, Amitava Choudhury

Chemistry Faculty Research & Creative Works

New synthesis routes were employed for the synthesis of three derivatives of iron hydroxo-, fluoro-, and mixed hydroxo-fluoro phosphates LiFePO ₄(OH)_xF_1-x where 0 ? x ? 1 with the tavorite structure type, and their detail electrochemical activities have been presented. The hydrothermal synthesis of the pure hydroxo-derivative, LiFePO₄OH, using phosphorous acid as a source of phosphate yielded good quality crystals from which the crystal structure was solved for the first time using SC-XRD (single crystal X-ray diffraction). The fluoro derivative, LiFePO₄F, was prepared as a very fine powder at low temperature in …

Communication: Rigorous Quantum Dynamics Of O + O₂ Exchange Reactions On An Ab Initio Potential Energy Surface Substantiate The Negative Temperature Dependence Of Rate Coefficients, Yaqin Li, Zhigang Sun, Bin Jiang, Daiqian Xie, Richard Dawes, Hua Guo

Chemistry Faculty Research & Creative Works

The kinetics and dynamics of several O + O₂ isotope exchange reactions have been investigated on a recently determined accurate global O₃ potential energy surface using a time-dependent wave packet method. The agreement between calculated and measured rate coefficients is significantly improved over previous work. More importantly, the experimentally observed negative temperature dependence of the rate coefficients is for the first time rigorously reproduced theoretically. This negative temperature dependence can be attributed to the absence in the new potential energy surface of a submerged "reef" structure, which was present in all previous potential energy surfaces. In addition, contributions …

Heat Release Of Polyurethanes Containing Potential Flame Retardants Based On Boron And Phosphorus Chemistries, Vladimir Benin, Bastien Gardelle, Alexander Morgan

Chemistry Faculty Publications

Using a polyurethane of methylene diphenyl isocyanate and 1,3-propane diol, several new non-halogenated aromatic boron and phosphorus flame retardants were evaluated for heat release reduction potential using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods, and were then analyzed via spectroscopic methods to determine if the flame retardant was still present in the final product. PCFC testing on the resulting products showed that the flame retardant molecule can have different effects on heat release depending upon how it is mixed into the polyurethane. Some …

The Nucleic Acid Binding Properties Of The Pwi Motif, Hamideh Keshavarz-Mohammadian

Masters Theses

The PWI motif is a highly conserved domain that contains a Proline-Tryptophan-Isoleucine (PWI) tripeptide sequence, for which it is named. Proteins that contain a PWI motif are known to be involved in the constitutive and alternative splicing and the 3'-end processing of messenger RNA transcripts. The hypothesized role of the PWI motif is to nonspecifically interact with nucleic acids. The PWI motif is capable of binding both doublestranded and single stranded forms of DNA and RNA. The structure of the highly conserved core of the PWI motif reveals that it adopts a four-helix bundle fold. The structured core domain, however, …

Chitosan-Cellulose Composite For Wound Dressing Material. Part 2. Antimicrobial Activity, Blood Absorption Ability, And Biocompatibility, April L. Harkins, Simon Duri, Luther C. Kloth, Chieu D. Tran

Clinical Lab Sciences Faculty Research and Publications

Chitosan (CS), a polysaccharide derived from chitin, the second most abundant polysaccharide, is widely used in the medical world because of its natural and nontoxic properties and its innate ability for antibacterial and hemostasis effects. In this study, the novel composites containing CS and cellulose (CEL) (i.e., [CEL + CS]), which we have previously synthesized using a green and totally recyclable method, were investigated for their antimicrobial activity, absorption of anticoagulated whole blood, anti-inflammatory activity through the reduction of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and the biocompatibility with human fibroblasts. The [CEL + CS] composites were found to …

Synthesis Of 4'-Ester Resveratrol Analogues, Chromium Trioxide Oxidation Of Terpenes, And Synthesis Of Mimics Of (-)-Englerin A, Mark Jeffrey Acerson

Theses and Dissertations

4’ -ester analogues of resveratrol were synthesized using reaction conditions developed to produce mono-ester products in the presence of two other unprotected phenols. Basic conditions were employed to deprotonate the most acidic 4’ phenol followed by addition of anhydrides or acid chlorides to give the ester product. The reaction favored 4’-ester formation in polar aprotic solvents with DMSO being the optimal solvent.

(—)-Englerin A is a guaiane-type sesquiterpene containing two ester side chains. Mimics of (—)-englerin A were proposed that retained the ester side chains while replacing the non-polar core with less complicated structures. These proposed mimic cores would maintain …

Extension And Applications Of The Gvvpt2 Method To The Study Of Transition Metals, Patrick K. Tamukong

Theses and Dissertations

The ground and low-lying excited electronic states of molecules of the first ( 2 Sc , 2 Cr , 2 Mn , and 2 Ni ) and second ( 2 Y , 2 Mo , and 2 Tc ) row of transition elements have been investigated for the first time with the generalized Van Vleck second order multireference perturbation theory (GVVPT2) method, a variant of MRPT. All potential energy curves (PECs) obtained in these studies were smooth and continuous; that is, they are free from wiggles or inflexion points. In order to account for relativistic effects, which become important in …