Physical Sciences and Mathematics Commons^™

General Chemistry Students’ Cognitive Engagement And What They Attend To During A Three-Dimensional Modeling Activity Focused On Chemical And Physical Properties Of Coordination Complexes, Hailey Knoeferl, Tiyana Mccullough, Tia Gordon, Cassidy Terrell, Adriane Randolph, Kimberly Linenberger Cortes

Symposium of Student Scholars

In chemistry, three-dimensional models are being used to help students comprehend advanced topics within the subject. Because a greater cognitive load is often related to three-dimensional models, learning what raises the cognitive load and determining the best way to measure it is critical. From there, steps can be taken to help lower the cognitive load and make the material easier for students to comprehend. To understand cognitive load concerning models, students were presented with physical three-dimensional models of various coordination complexes and asked to determine bond angles, the metal present in the complex, polarity, and to draw possible isomers and …

Computer Simulation Of Raman Spectra And Mode Assignment: Application To Methane, Oluwaseun Omodemi, Ciara Tyler, Martina Kaledin

Symposium of Student Scholars

This work uses driven molecular dynamics (DMD) method, in conjunction with an analytic PES calculated using MP2/aug-cc-pVDZ energies to identify and assign Raman vibrational modes of methane. Recently, a new linearized approach was proposed for the Polarizability Tensor Surfaces (PTS) that yields a unique solution to the least-squares fitting problem and provides a competitive level of accuracy compared to the non-linear PTS model. We used the previously reported B3LYP/6-31+G(d) molecular geometries for CH₄ and generated a new PTS at the MP2/aug-cc-pVDZ level of theory. The performance of the linearly parametrized functional form for the CH₄ PTS is examined. …

Corrosion Prevention Of Aluminum Alloy, Andrea Brenner

Symposium of Student Scholars

Aluminum alloy (Al-alloy) is a widely used metal in construction, aerospace, aviation, and other necessary fields due to its lightweight and tweakable properties. However, corrosion is inevitable on metals and alloys, and that causes millions of dollars of revenue loss every year. Therefore, we propose to research fabricating coating to prevent corrosion on Al-alloy. This study uses an iron-based metal-organic framework (MOF) and polyurethane (PU) based composite coating to prevent corrosion on the Al-alloy. The makeup of the composite material is changed by varying the percentage of MOF. In addition, a binder is also used to enhance the homogenization between …

Spin Interactions In New Donor-Acceptor Complexes, Ju Chen

Chemistry and Chemical Biology ETDs

Transition metal complexes ligated by Donor-Acceptor (D-A) biradicals are of interest for probing the degree of electronic coupling between chemically biased radical fragments. The unique nature of their electronic coupling has allowed these systems to serve as ground state analogues of charge separated excited states generated by photoexcitation. We have been interested in how the nature of the acceptor radical affects the magnitude of the electronic coupling matrix element in these biradicals. As such, we have synthesized a new series of D-A semiquinone-verdazyl (SQ-VD) biradical ligands and their transition metal complexes. We have characterized these new complexes by x-ray crystallography, …

Optimization Of Adsorption Of Methylene Blue Dye On Activated Charcoal, Abigail Seputro

Research and Creativity Symposium

Methylene blue and crystal violet are cationic dyes of high intensity that are commonly discharged in wastewater. The colored compounds in wastewater inhibit sunlight penetration in waterways, resulting in the destruction of aquatic ecosystems. Activated carbon offers an attractive option for the efficient removal of dyes from wastewater due its excellent adsorption ability, highly porous structure, and large thermal/chemical stability. This study was conducted in order to investigate the adsorption of methylene blue dye from aqueous solution by various types of activated charcoal using UV-Vis spectroscopy. The effects of temperature and adsorbent quantity were studied to optimize the efficiency of …

Computer Simulations And Network-Based Profiling Of Binding And Allosteric Interactions Of Sars-Cov-2 Spike Variant Complexes And The Host Receptor: Dissecting The Mechanistic Effects Of The Delta And Omicron Mutations, Gennady M. Verkhivker, Steve Agajanian, Ryan Kassab, Keerthi Krishnan

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, we combine all-atom MD simulations and comprehensive mutational scanning of S-RBD complexes with the angiotensin-converting enzyme 2 (ACE2) host receptor in the native form as well as the S-RBD Delta and Omicron variants to (a) examine the differences in the dynamic signatures of the S-RBD complexes and (b) identify the critical binding hotspots and sensitivity of the mutational positions. We also examined the differences in allosteric interactions and communications in the S-RBD complexes for the Delta and Omicron variants. Through the perturbation-based scanning of the allosteric propensities of the SARS-CoV-2 S-RBD residues and dynamics-based network centrality and …

Building-Block Approach To The Discovery Of Na8mn2(Ge2se6)2: A Polar Chalcogenide Exhibiting Promising Harmonic Generation Signals With A High Laser-Induced Damage Threshold, Srikanth Balijapelly, Andrew J. Craig, Jeong Bin Cho, Joon I. Jang, Kartik Ghosh, Jennifer A. Aitken, Aleksandr V. Chernatynskiy, Amitava Choudhury

Physics Faculty Research & Creative Works

A new polar quaternary chalcogenide, Na8Mn2(Ge2Se6)2, has been synthesized using the building-block approach by reacting preformed Na6Ge2Se6 and MnCl2 at 750 °C. The structure consists of layers of [Na(1)Mn(Ge2Se6)]3– stacked perpendicular to the c-axis and sodium ions occupying the interlayer space. An indirect bandgap of 1.52 eV has been calculated using density functional theory, which is expectedly underestimated compared to the observed optical bandgap of 1.95 eV derived from diffuse reflectance spectroscopic measurements in the UV/Vis/NIR region. Magnetic measurements confirm the paramagnetic nature of Na8Mn2(Ge2Se6)2 with an experimental magnetic moment of 5.8 μB in good agreement with the theoretical spin …

Approaches In Molecular Engineering To Optimize The Desired Properties Of Photoactive Molecules, Douglas Joseph Breen

Chemistry and Chemical Biology ETDs

Within this dissertation, photochemical systems that bear significance to next-generation photonic materials and devices are explored. Notable advances in the design, synthesis, and characterization of three distinct groups of photoactive molecules are achieved through molecular design and spectroscopic analysis. First, novel ruthenium sulfoxide complexes bearing substituted phosphine ligands are found to provide extraordinary control over photoisomerization quantum yields. A comparison of these complexes reveals ground-state characteristics that are instrumental in this reactivity, while a novel spectroscopic technique provides rare structural evidence for an O-bonded metastable isomer. Ruthenium complexes bearing chelating carbene-sulfoxide ligands rapidly thermally revert from the O-bonded metastable isomer …

Optimizing The Alkylation Of Carboxylic Acid Derivatives For Use In The Synthesis Of The Oxidative Metabolites Of Dehp, Hannah Harris

Research and Creativity Symposium

Di(2-ethylhexyl) phthalate (DEHP) is a widely used chiral plasticizer whose primary metabolite (MEHP) and secondary oxidative metabolites have been shown to have peroxisome proliferating and endocrine disrupting effects in mice. The synthesis of these oxidative metabolites is necessary to study their binding affinity to nuclear receptor PPAR. Here, the first step in these syntheses, the construction of the alkyl side chains, was optimized by comparing GC-MS data showing percent composition of the desired alkylation product under varying reaction conditions. The most successful yield with the fewest byproducts was obtained when using LDA as the base, tert-butyl butanoate as the starting …

Elemental Characterization Between Single Origin Arabica And Peaberry Robusta From Vietnam, Docia Atanda, Takoda Chris, Carleigh Mcdonald, Emily Morris

Research and Creativity Symposium

Coffea arabica and coffea canephora (robusta) are the two most common species of coffee. With the rising price and rising global demand for coffee there is an increasing incentive for distributors to pass cheap coffee as more expensive coffee creating a need to verify the authenticity of coffee. This research was conducted to perform elemental characterization of Nguyen brand arabica and robusta coffee grown in Vietnam. The coffee beans were ground and digested by nitric acid digestion. The samples were run using inductively coupled plasma atomic emission spectrometry (ICP-AES) and compared with prepared standards containing calcium, iron, rubidium and manganese. …

Ground Water Iron Concentration, Caroline Sampson, Emma Jones, Katherine Lauderbaugh, Joey Pack

Research and Creativity Symposium

Groundwater samples from Louisa County contain high unknown quantities of iron, resulting in red rust-stained sediments in areas with constant water. This leads to concern over the amount of Fe that contaminates the water, as the WHO suggests levels below 0.3 mg/L, while levels in groundwater can be as high as 5 mg/L. The unknown concentrations of iron can be evaluated through the use of UV-Vis spectroscopy. A set of Fe standards was created using a known concentration (2.5-100 μM) which combined with phenathroline to create an orange ferroin complex, in addtion to hydroxylamine and acetate buffer. The ferroin complex …

Analysis Of Glyphosate In Pond Water By Hplc, Madison Minvielle, Abigail Seputro, Dorothy Haas, Zahia Clemmons

Research and Creativity Symposium

Glyphosate is the main ingredient in several herbicides such as Roundup, Agrisel, and Eraser. While glyphosate is typically not directly harmful to aquatic life, there is the potential for the compound to be indirectly harmful when it is present in runoff that enters aquatic ecosystems. A sample of water from a pond local to sod and agricultural farms was obtained to analyze the presence of glyphosate and make an assessment based on the concentration of glyphosate in the sample of the risk of toxicity to the aquatic life. A 1 mL glyphosate standard of concentration 1000 ug/mL was used to …

Initial Investigation Of The Chemical Contribution Of Hemp To Beer Aroma, Caitlyn Hunt

Undergraduate Research Competition

As the availability and consumer interest in hemp materials increases, the production and consumption of products incorporating hemp and CBD oil has increased. The industrial hemp market has seen a steady increase in value of the market and is projected to reach 26.6 billion USD. South Carolina has seen an increase in the cultivation of hemp and the production of CBD oil. There has been some interest in the market for alternative uses for both raw hemp and the leftover material following the CBD oil extraction process. This interest is a result of hemp-flavored beers in the market. The use …

A Step In The Search For Arboviruses: Determining Blood Meals Eaten By Mosquitoes, Carson Mickey, Olivia Shirley, Elody Bensch

Undergraduate Research Competition

Mosquitos are known to spread diseases throughout communities, including viruses, referred to as arboviruses. In 2017, DHEC reported 158 incidents of arboviruses in South Carolina, including West Nile, Dengue Fever, and Zika virus. The infections rate was up from the year before when 124 incidents of arboviruses were reported. Monitoring these infected mosquitos can be an asset for proper health protection in our community. Understanding what the mosquitoes are feeding on can help us better monitor the zoonosis threats that our community faces. A series of primers have been developed that target unique sequences in the cytochrome b gene in …

Identification And Characterization Of Small Regulatory Rna In Streptococcus, Klea Hoxha, William C. Oakes Iii, Nicole M. Ward, L. Brooke Busby

Undergraduate Research Competition

Background: The human gut is a rich habitat for a diverse population of bacteria. These bacteria play a vital role in a multitude of functions. They affect immune responses, metabolism, and even neurological activities. Some inhabitants of the gut biome include the lactic acid bacteria: Streptococcus thermophilus, Lactobacillus acidophilus, and Lactobacillus bulgaricus. These bacteria are essential members of the flora and are non-pathogenic, however, some of their relatives like Streptococcus pyogenes cause severe diseases such as flesh-eating disease. The metabolic functions of these bacteria are mediated by small regulatory RNAs (sRNAs), which are noncoding RNA sequences that fold into complex …

Plasmonically-Active Nanomaterials For Enhanced Second-Harmonic Generation And Chemical Reactions, Denis Ab Therien

Electronic Thesis and Dissertation Repository

Upon excitation by an electromagnetic field, metallic nanomaterials will produce highly localized areas of electromagnetic enhancement, a phenomenon known as localized surface plasmon resonance (LSPR), which can be applied to a variety of techniques including second-harmonic generation (SHG) and surface chemistry. These tunable LSPRs can be modelled prior to fabrication by finite-difference time-domain (FDTD) calculations and observed experimentally by SHG microscopy (SHGM). In this thesis, two types of nanomaterials were characterized using SHGM: plasmon-active dendritic fractals (dendrimers) and transition-metal dichalcogenides (TMDs). Dendrimers with specific geometries and LSPRs were used to demonstrate how nanomaterial symmetry affects SHG as well as how …

Biochemical Characterization Of Induced Pluripotent Stem Cell-Derived Cardiomyocytes As A Model Of Barth Syndrome, Alisha J. House

ETD Archive

Barth Syndrome (BTHS) is an X-linked inborn error of metabolism (IEM) which manifests as a multi-systemic disease. One of the primary symptoms is dilated cardiomyopathy, and alongside the cardiovascular disease that arises, patients often experience metabolic abnormalities such as 3-methylglutaconic aciduria, growth retardation, and neutropenia. There has been a need for the development of a suitable in vitro modeling system which will accurately recapitulate the biochemical and physical nature of BTHS. The purpose of this project has been to develop a model for studying the biochemical pathogenesis of Barth Syndrome using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). To achieve …

An Investigation Into The Protein Dynamics And Proton Transfer Mechanism Of Class-A Β-Lactamase (Ctx-Ms) By Nmr Spectroscopy, Radwan Ebna Noor

USF Tampa Graduate Theses and Dissertations

Extended-spectrum β-lactamases (ESBLs) of different Enterobacteriaceae (e.g. Escherichia coli, Klebsiella pneumoniae) have developed significant resistance mechanisms against antibiotics. ESBLs, like class A CTX-Ms (cefotaximases) enzymes hydrolyze the β-lactam ring of different antibiotics such as penicillins and third-generation oxyimino-cephalosporins. Although CTX-Ms are repeatedly found in many clinical and community settings, molecular-level information on their function/activity is currently limited to structural studies performed by X-ray crystallography. In order to gain further insights into the structure and functions of this class of proteins, it is also essential to fully understand their dynamic and chemical properties in solution. In order to better understand the …

Organic Chemistry Through Dance, Holly Gibson

Undergraduate Research Conference

This research project explores representing organic chemistry mechanisms using dance. Dancers represent molecules, electrons, and atoms in demonstrating the movement of electrons and bonds created and broken by the movement. It was concluded that some organic mechanisms and ideas can be easily transferred to a dance concept, while others take more time and exploration. Additionally, dancers representing the atoms and electrons were able to have a better grasp of what was occurring, regardless of chemical education background. This leads to the conclusion of a new way to implement kinesthetic learning into the chemistry classroom. The purpose of the videos are …

Bomb Calorimetry: A New Method Of Cec Determination, Trace Washburn

Undergraduate Research Conference

A new method of determining the cation exchange capacity (CEC) of clay minerals was examined. This method involved exchanging the smectite clay with organic cations and using bomb calorimetry to measure the energy of combustion of the material. Because the clay is noncombustible, the energy is completely dependent on the amount of organic present, which is dependent on the CEC of the clay. Two organic cations, tetrapentylammonium and octadecyltrimethylammonium , with similar size but much different shape were used. For clays with lower CECs, using the more symmetric ion yielded better accuracy (4.24%), while for clays with higher CEC, using …

Casein Kinases Are Required For The Stability Of The Glucose Sensing Receptor Rgt2 In Yeast, Danny Bloor

Liberty University Research Week

Undergraduate

Basic

Historical Investigation Of New London Alum Springs Through Elemental Analysis, Chloe Vernon, Asia Eskaros

Liberty University Research Week

Undergraduate

Textual or Investigative

Isolation And Analysis Of Extracellular Vesicles From Lactic Acid Bacteria, L. Brooke Busby, Isabel Myers, Klea Hoxha

Undergraduate Research Competition

Extracellular Vesicles, also referred to as EVs, are spherical lipid membrane-bound vesicles produced by both Gram positive and Gram negative bacteria. These vesicles are secreted into the extracellular space and play important functions in cellular and host communication, elimination of competitors, virulence, detoxification of environmental stress, and nutrition sensing. They are often packed with proteins, enzymes, lipids, and nucleic acids like DNA or RNA molecules among other biological entities. Streptococcus thermophilus is a lactic acid bacterium (LAB), inhabiting the human digestive tract, that has been shown to produce EVs. The bacterial flora has a great impact on the host immune …

Identifying Conditions For Indole Additions To Aldehydes To Be Applied To The Synthesis Of Phidianidine Analogues, Lindsay Newton, Anna Tingler

Undergraduate Research Competition

Phidianidines are natural products originally isolated from Phidiana Militaru, a shell-less mollusk. The compounds are comprised of an indole, a 1,2,4 oxadiazole ring, and an aminoalkylguanadine group on the C-3' position of the ring. They have been found to neutralize reactive oxygen species and are agonists of the µ-opioid receptor. Other groups have synthesized analogues of the phidianidines that have substituted the aminoalkylguanadine group for a biaryl ring system, which has been shown to have neuroprotective properties. The current synthetic routes make substitution of the indole and changing the oxadiazole difficult, so our goal is to create a synthesis that …

Environmental Bacteriophage Detection On Coastal Carolina University Campus, Hailey Oldfield, Madison Gentilo

Undergraduate Research Competition

The purpose of this study is to utilize bacteriophage as an environmental indicator of the presence of harmful bacteria in waterways on Coastal Carolina's campus and to identify bacteriophage that could be used to control bacterial blooms. Bacteriophages are viruses that infect bacteria. These viruses are found ubiquitously in the environment and are the most abundant organism on Earth. Eleven sites are designated for weekly sample collection. Water samples are filtered and amplified using strains of E. coli B and E. coli K12 to allow potential viruses in the sample to proliferate to detectable levels. Plaque assays are used as …

Exploration Of The Effects Of Bond Length On The Potential Energy Curves For Diatomic Compounds, Ramsey Cotton, Ashley Summers

Research and Creativity Symposium

Bond dissociation energy (BDE) is the unique energy required to break a bond in a molecule into its respective atoms or molecular fragments. In this study, the theories behind harmonic and anharmonic oscillators, which address BDE of diatomic molecules, were employed to relate the length of a bond to its corresponding potential energy. A computational chemistry program was utilized to investigate the potential energies of diatomic hydrogen (H2), bromine (Br2), and hydrogen bromide (HBr). The diatomic molecules were found to obey Hooke’s law for harmonic oscillation at low energies, but as the energy increased with stretching the bond, deviations were …

Transition State Theory: Thermodynamics And Kinetics Of Ammonia Production Via Dft Functional, Madeleine Stanisha, Emma Freakley

Research and Creativity Symposium

The thermodynamics and kinetics of a proposed mechanism for ammonia production from nitrogen and hydrogen gas were analyzed by utilizing transition state theory (TST) and density functional theory (DFT). The enthalpy and entropy for the overall reaction were computed via DFT functionals, PBE0 and B3LYP, and were compared to literature values for the thermodynamics of ammonia production. PBE0 produced an enthalpy and entropy for the overall reaction of -81.32 kJ/mol and -197.75 kJ/mol K with percent errors of -11.5 % and -0.18 %, respectively. In comparison, B3LYP produced an enthalpy and entropy for the overall reaction of -1923.02 kJ/mol and …

Assessing The Correlation Between The Electron-Nucleus Binding And Electron-Electron Repulsion, Isabella Groover, Joey Henry

Research and Creativity Symposium

Multi-electron systems add a level of complexity to the Schrödinger equation by introducing an electron-electron repulsion term into the potential energy. The electron-electron repulsion term is difficult to assess utilizing the Schrödinger equation due to extensive computation required. In this study, the binding energy between the 1s electron(s) and the nucleus of the atoms in the first two rows of the periodic table were determined using an ab initio computational method, 6-31G*, that incorporated the electron-electron repulsion instead of assuming that electrons act independently of one another. As the number of electrons increased, pushing the 1s electrons closer to the …

Using Potential Energy Surfaces Of Diatomic Molecules To Determine The Bond Dissociation Energy Via Computational Chemistry, Skye Curry, Nathaniel Holbrook

Research and Creativity Symposium

The bond length along which two atoms vibrate can be altered in order to construct a potential energy surface used to determine the bond dissociation energy of a diatomic molecule. Carbon monoxide was initially used as the diatomic molecule of choice in this ChemCompute lab experiment. The bond length of carbon monoxide was altered in the range of .086 to .177 nm, and the electronic energy produced was recorded. A potential energy curve was constructed at these bond lengths until the molecule dissociated; a relative potential energy curve was then constructed. The equilibrium bond length, 0.113 nm, and the well …

Method Development For Analysis Of Dietary Supplements Using Flame Atomic Absorption Spectroscopy, Elijah Hongsermeier-Baxter

2022 Student Academic Showcase

Dietary supplements are typically ingested by customers who already have a well-balanced diet and an awareness of a personal, specific deficiency or fitness goal serving as their reason for doing so. Accordingly, the accuracy of the composition of a supplement on its label is paramount in determining if said tablets are worthwhile for customer use. A method was developed to determine the accuracy of the nutrition facts labels on two different brands of iron and zinc supplements. Samples were prepared via dissolution in nitric acid followed by filtration, dilution and analysis via flame atomic absorption spectroscopy. A standard curve method …