Chemistry Commons^™

Evaluation Of A Radium-Thorium Disequilibrium Sediment Method Used To Model And Assess Porewater And Submarine Groundwater Exchange In The Coastal Marsh, Madeline R. Bodine

Theses and Dissertations

Ground, pore, and surface water exchange has been extensively studied in beach and near shore environments but has been long neglected in saltmarsh systems due to their complexity. Saltmarsh systems are of particular importance as they are the interface between fresh and saltwater. Saltmarshes impact carbon exchange, release and sequestration, and they process particulate matter. Understanding the characteristics of a marsh system such as the nutrient and particulate loads in conjunction with the flux of water exchange through the marsh provides a deeper understanding of these systems and can impact our understanding of the global water and carbon cycles, as …

Hydrothermal Liquefaction Of Saccharina Latissima For The Production Of Biofuel, Mayokun A. Oke

Mechanical Engineering Theses

We performed hydrothermal liquefaction of brown macroalga (Saccharina latissima) in the presence of homogenous and heterogenous catalysts such as KOH, Na₂CO₃, Pd/C, HZSM-5, Ce/HZSM-5, and Ni/SiO₂-Al₂O₃ in hot compressed water, to investigate their effects on product yield and composition in the biocrude. To investigate hydrocarbon production, we used methanol as co-solvent (methanol-to-water 1/4 vol.%) and as the only liquefaction solvent. We carried out the experiments in a batch reactor at 330^oC and 120-130 bar, and varying temperature, algae-to-water ratio, residence time, and pretreatment method. The biocrude yields …

Simulating A Flexible Water Model As Rigid: Best Practices And Lessons Learned, Raymond Weldon, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

Two ways to create rigid versions of flexible models are explored. The rigid model can assume the Model’s Geometry (MG) as if the molecule is not interacting with any other molecules or the ensemble averaged geometry (EG) under a particular thermodynamic condition. Although the MG model is more straightforward to create, it leads to relatively poor performance. The EG model behaves similarly to the corresponding flexible model (the FL model) and, in some cases, agrees even better with experiments. While the difference between the EG and the FL models is mostly a result of flexibility, the MG and EG models …

Synthesis And Characterization Of Some Disubstituted Cyclopentadienyl Rhenium Complexes As Potential Candidates In Semiconductive Materials, Chloe Vernon

Senior Honors Theses

Since 2000, when the Nobel Prize in Chemistry as awarded for conductive polymer research few studies have been performed concerning the conductive capabilities of discrete organometallic compounds. For this project, organometallic compounds were formed specifically with a transition metal included in the structure. Through oxidation and reduction reactions, the variation in the electrical conductivity could allow for an analysis of whether this unique structure would allow for tunability. The goal of this research was to begin with aromatic substituted fulvenes and perform various multistep synthesis processes, utilizing thallium salt intermediates, to produce several disubstituted cyclopentadienyl rhenium complexes. In this project, …

Phenotypic And Target-Based Drug Discovery, Angelica Veronica Carmona

Theses & Dissertations

Batten Disease or Neuronal Ceroid Lipofuscinosis (NCL) is a group of rare, fatal, inherited pediatric neurodegenerative lysosomal storage disorders. NCLs are characterized by intracellular accumulation of an auto-fluorescent lipopigment called ceroid lipofuscin and neurodegeneration. Several forms of NCLs exist, some of which share some of the same features and symptoms but vary in severity and onset of symptoms with respect to age. Some common symptoms include progressive loss of vision, mental and motor deterioration, epileptic seizures, premature death, and in the rare adult-onset, dementia. Subtypes of NCLs occur when one of 13 different genes are mutated, and only two subtypes …

Toward The Yeast Surface Display Of Microviridin B, Jillian Leigh Stafford

Chemistry and Chemical Biology ETDs

Humans have turned to natural products for medicinal therapeutics for millennia. In recent years, the ribosomally synthesized and post-translationally modified peptide (RiPP) class of natural products have garnered a lot of attention due to their ability for heterologous expression, relative ease of mutation, and vast biological activates. Microviridins are a family of RiPPs that contain a tricyclic cage-like structure through the formation of two lactone rings and one lactam ring catalyzed by two ATP-grasp ligase family enzymes. Microviridins are potent inhibitors of serine proteases and mutational studies of a small number of residues indicates the potential of peptide engineering protease …

Engineering Of Bio-Based And Synthetic Polymers: Synthesis And Application In Superabsorbent Materials And Antibacterial Agents, Jihyeon Hwang

Theses and Dissertations

A polymer consists of a large number of monomer units, which can be obtained naturally or via a chemical process called polymerization. Polymers are important materials that are used in our daily life. Life would not be possible without these polymers, either from plant biomass or petroleum-derived synthetic polymers. The substitution of petroleum-derived to biomass-based polymers has been highlighted to mitigate adverse environmental impact. However, the use of bio-based polymers is still a significant challenge for more demanding applications. In this dissertation work, the engineering of both bio-based and synthetic polymers and their properties are investigated.

In Chapter 1, the …

Coordination Environment And Thermodynamics Of Colloidal Quantum Dots In Polar Solvents, Nuwanthaka Prasad Jayaweera Millaniyage

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) have been extensively investigated due to their attractive properties such as size-tunable absorption and emission spectra, large molar extinction coefficients, and significant photostability. These properties make them promising candidates for optoelectronic, photocatalytic, and biomedical applications. Common synthetic procedures of QDs produce nanocrystals capped with long-chain fatty acid derivatives which are stabilized in high boiling point solvents. Especially for bioimaging applications, the exchange of these native hydrophobic ligands with hydrophilic ligands should be performed, while preserving the smaller hydrodynamic radius. The coordination environment and thermodynamic parameters of the ligand exchanges should be carefully investigated to engineer …

Biochemical, Structural, And Immunological Characterization Of Selected Panallergens, Andrea Leigh O'Malley

Theses and Dissertations

Allergies throughout the world are increasing in prevalence and severity. Although the direct causes of the development of allergies are not confirmed, study of proteins that cause reactions will lead to a deeper understanding of allergy. This work focuses on three panallergen families, profilins, parvalbumins, and arginine kinases, to further elucidate the background of allergy from the point of view of the allergens themselves. In Chapter 1, we evaluate pollen, fruit, and mite profilins in the context of allergy, showing the relevance of conserved cysteine residues in stability and oligomerization as well as the first data on cross-reactivity between plant …

Structure Property Investigation And Applications Of Self-Assembled Triphenylamine Bis Urea Macrocycles, Md Faizul Islam

Theses and Dissertations

Porous organic crystals can be advantageous as nanoreactors and in sensing, separations, and storage. The Shimizu group utilizes bifurcated urea hydrogen bonding to direct the assembly small building block into pillars and columns affording functional porous crystals. Recently, our group has examined the incorporation of triphenylamines within the framework of bis-urea macrocycles. These macrocycles assemble into columns that contain the solvent of crystallization bound within the channels. Heating the crystals leads to removal of the solvent and activates the host for guest exchange by single-crystal-to-single[1]crystal transformations. Different electron accepting molecules can be encapsulated inside the pore of the host …

Molecular Devices For Measuring Weak Solvophobic Interactions And The Development Of Pedagogical Tools For Organic Chemistry Students, Alexander N. Manzewitsch

Theses and Dissertations

The main topics of this dissertation are: 1) the development and discussion of a new molecular balance for measuring alkyl-alkyl interactions in a wide array of organic solvents, 2) the development of linear solvation energy relationships between solvent interaction parameters and solvent accessible surface area (SASA) in CH-arene interactions, and 3) the development of online resources for helping undergraduate students perform organic chemistry mechanisms problems well.

The solvophobic effect, that is the forced association between two solutes due to intermolecular attraction of the solvent molecules, is ubiquitous in organic chemistry and responsible for many significant phenomena thereof. However, there is …

Mapping Per- And Polyfluoroalkyl Substances (Pfas) In South Carolina Surface Waters: Are There Hotspots?, Thomas C. Geiger

Senior Theses

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used in consumer products for their unique chemical properties. PFAS compounds are resistant to water, oil, heat, and grease, making them useful for a wide variety of everyday items such as non-stick cooking pans, food packaging, electronics, carpets, upholstery, paints, adhesives, and personal care products.¹ The resilient nature of PFAS has made these compounds immensely popular with consumers but has since been considered a potential environmental and public health hazard for their ability to bioaccumulate and for their stability in the environment. More than 6000 PFAS have been discovered in the …

Surface And Alloy Engineering Of Halide Perovskite (Cspbx3) Nanocrystals For Efficient And Stable Optoelectronics, Sakiru L. Abiodun

Theses and Dissertations

Organic and inorganic halide perovskite quantum dots (QDs) (in form of ABX₃, where A is organic cation e.g CH₃NH₃⁺ or inorganic cation e.g Cs⁺) have emerged as an intriguing alternative to the widely studied chalcogenide and pnictide QDs. Their excellent optoelectronic properties such as large absorption coefficient, high carrier mobility, wide color gamut, long electron-hole diffusion lengths, and tunable bandgap energy are largely responsible for their wide acceptability in various electronic devices. However, despite this enthusiasm, the problem of purification, long-term stability, lead toxicity and inadequate knowledge of their surface chemistry still …

Vaccinia Virus And Measles Virus As Oncolytic Vaccines: The Modulation Of The Viral Infectivity Via Surface Conjugations, Monchupa Kingsak

Theses and Dissertations

Oncolytic virus (OV) therapy has been shown to be an effective targeted cancer therapy treatment in recent years, providing an avenue of treatment that poses no damage to surrounding healthy tissues. Not only do OVs cause direct oncolysis, but they also amplify both innate and adaptive immune responses generating long-term antitumor immunity. However, a key challenge facing oncolytic virotherapy is neutralizing antibodies in vaccinated patients, leading to the viral clearance after systemic administration and failure in the treatment. The encapsulation of OVs using biocompatible polymers is one of the promising methods to prevent the viral clearance from antiviral immune responses. …

Expanding Tailorable Nanomaterial Synthesis With Persistent Micelle Templates, Eric R. Williams

Theses and Dissertations

The control of block polymer micelle dimensions while in solution is critical for a range of emerging applications in diverse fields from drug delivery and nanoreactors to use as sacrificial templates for porous nanomaterials. When under kinetic control, micelles will maintain a constant average size and thus aggregation number (N_agg) through the suppression of chain exchange mechanisms. Such kinetic control effectively enables the decoupling of micelle dimensions from solution conditions. In other words, kinetically trapped micelles can resist reorganizations brough about by e.g., the addition of metal nanoparticles. However, such micelles are traditionally governed by a fickle �� …

Exploring New Techniques For Precision Deuteration Of Alkenes And Alkynes, Zoua Pa Vang

Dissertations (1934 -)

Deuterium labeled compounds are often utilized in chemical research as internal standards in mass spectrometry, to study reaction mechanisms and in the pharmaceutical industry to slow the rate of metabolism. With the increase interest for deuterium labeled molecules, there is a renewed interest in selective methods for the installation of deuterium atoms into small organic molecules. However, current methods to incorporate deuterium atoms into organic molecules can lead to isotopic mixtures such as isotopologues and isotopomers. These isotopic species are indistinguishable due to their similar physical properties, leading to inseparable products by common purification techniques. Furthermore, common spectroscopic techniques to …

Using Capillary Electrophoresis To Quantify Competitive Binding Of Adsorbates To Silver Nanoparticles, Christopher D. Chung , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are increasingly used commercially and medically due to their antimicrobial and antibacterial properties. With increased use comes increased release of AgNPs into the environment, and once released, AgNPs can form coronas with molecules ranging from biomolecules to proteins to natural organic matter (NOM). The molecules in the corona adsorb to the surface of the AgNPs, drastically altering their innate properties such as cytotoxicity and binding behavior. In this study, we characterize and quantify model AgNP-adsorbate systems by obtaining their relevant reaction parameters through three different affordable analytical techniques, including dynamic light scattering (DLS), UV-vis spectroscopy, and capillary …

Master Equation Modeling Of Prompt Dissociation Kinetics For Isoprene Derived Criegee Intermediates, Rory R. Schmidt , '23

Senior Theses, Projects, and Awards

Isoprene ozonolysis is a major atmospheric producer of atmospheric oxidizers and aerosols. This complex reaction pathway forms an exothermic cascade, where constant competition between bimolecular sinks, unimolecular isomerizations, and collisional relaxation dictate reactivity. This work focuses on two isoprene derived Criegee intermediates, methacrolein oxide (MACR oxide) and formaldehyde oxide (FO). While the potential energy surface of FO is well understood, the reactivity of energetically excited FO has not been explored in detail. MACR oxide isomerization and primary products have been adequately characterized and explored computationally and experimentally, but the potential energy surface beyond isopropenyl dioxirane has not received the same …

Biophysical And Structural Characterization Of Non-Canonical Dna Structures, Paul C. Seth , '23

Senior Theses, Projects, and Awards

G-quadruplex (GQ) and i-motif (iM) non-canonical DNA structures can be formed by G- and C-rich sequences within the genome, respectively. GQ and iM DNA play important roles in different biological processes and are promising therapeutic targets. Recently, the first left-handed GQ (LHGQ) was discovered and much remains to be learned about the structure and function of LHGQ DNA.

In this thesis, we investigate the biophysical and structural behavior of two LHGQ-forming sequences from the human genome, from the Human Solute Carrier 1 (SLC) and nuclear receptor binding SET domain (NSD) genes. We found that flanking bases play an important role …

Method Design For Separation Of Non-Canonical Dna Structures Via Capillary Electrophoresis, Erin V. Chen , '23

Senior Theses, Projects, and Awards

G-quadruplex DNA structures are highly relevant subjects of biochemical study, implicated in human diseases and cancer. Conventional methods for G-quadruplex DNA structure separation are time-consuming, environmentally unfriendly, and low throughput. Thus, there is a pressing need for alternative methods of separation to be developed for G-quadruplex DNAs. Here we present work in designing a separation method using the capillary electrophoresis instrument. Capillary electrophoresis is a highly automated, reusable, and quantitative technique that separates analytes based on their size and charge. A capillary method for G-quadruplex separation would be a valuable analytical tool to supplement the biophysical methods available by addressing …

Pc-01 Synthesis Of Zinc Glycoconjugated Phthalocyanines As A Potential Phototherapeutic, Jessica A. Silva-Conejo, Katrina Mccarter, Tessa Greene, Joshua V. Ruppel

SC Upstate Research Symposium

Photodynamic Therapy (PDT) uses photosensitizers that are activated by light to produce singlet oxygen that can cause cell damage and potential cell death. Phthalocyanines are promising photosensitizers due to their absorption at clinically relevant wavelengths, meaning that they absorb at a wavelength that can penetrate deeper into tissues.

One challenge with using Phthalocyanines is that they have very low solubility in biological media. One potential approach to increase solubility is through glycoconjugation. Glycoconjugation can also be used as a strategy to increase selectivity toward targeted tissues. Glycoconjugated phthalocyanines can be synthesized using a copper catalyzed azide-alkyne cycloaddition reaction, otherwise known …

Potential Of Kaolin Clay On Formulation Of Water Based Drilling Mud Reinforced With Biopolymer, Surfactant, And Limestone, Paul M. Omary, Emanuel X. Ricky, Naswibu A. Kasimu, Makungu M. Madirisha, Kessy F. Kilulya, Esther H. J. Lugwisha

Tanzania Journal of Science

Drilling the wellbore into subsurface formations is the earliest stage in the life of a well that requires a suitable drilling fluid with good rheological and filtration control characteristics to achieve a successful drilling operation. This paper reports on the formulation of water-based drilling mud using kaolin clay reinforced with biopolymer, surfactant, and limestone from Tanzania. The raw materials used for the formulation were characterized using XRD, XRF, FTIR, and TGA techniques. The rheological properties, filtration loss, pH, and density of the formulated mud were measured using a viscometer, filter press, pH meter, and mud balance, respectively. The XRD results …

Adsorption Of Water Vapour On The Microstructure And Stability Of Cu-Zn Bimetallic Coordination Polymer, Bukunola K. Oguntade, Gareth M. Watkins

Tanzania Journal of Science

A current challenge in the design of synthesis lies in the incorporation of two or more transition metals into a coordination polymer. The most widely used approach has been to incorporate a second metal as a generally innocent (coordinatively saturated) part of a linear linker as in the case of multifunctional carboxylated porphyrins (MCPs). The empirical method has been used to obtain many other types of MCPs; however, the selective, direct replacement of one transition metal within a monometallic coordination polymer via controlled stoichiometry has not generally led to maintained structural fidelity. In this present work, three pyromellitic acid complexes …

Considerations For Curricular Reform In Undergraduate Chemistry: Cooperative Adoption Factors, Modeling Social Influence, And Focusing On Specific Populations, Jacob D. Mcalpin

USF Tampa Graduate Theses and Dissertations

This dissertation will go through the details of three projects highlighting considerations for curricular reforms in undergraduate chemistry. Improving the teaching of chemistry is facilitated by considering the problem from multiple directions, namely, faculty and students. In addition to the multiple perspectives, this dissertation also seeks to bring new methodologies into the spotlight to improve the toolbox for other chemistry or discipline-based education researchers. Additionally, this dissertation has shown in several locations how focusing in on subgroups within populations can reveal findings that would not have been apparent from a global average of the population. The three project describes in …

Interdisciplinary Diffusion Lab, Sable Rosana Canales, Chloe Gaban

Andrews University Teaching and Learning Conference

Diffusion is a principle in Physics, Chemistry, and Biology. Students can model the rate of diffusion based on particle size by contrasting blue and yellow dyes. Two petri dishes containing agar-agar receive a drop of dye at the center. The radius of expansion is recorded over time and variance increases linearly with time. Diffusion constants vary by particle size, allowing for a size ratio comparison between blue and yellow dyes. Relating the data to cells, students predict that smaller molecules diffuse into living cells, whereas larger molecules need some assistance from protein channels as in facilitated diffusion.

Traffic Lights For Catalysis: Stimuli-Responsive Molecular And Extended Catalytic Systems, Grace C. Thaggard, Johanna Haimeri, Roland A. Fischer Prof. Dr., Kyoung Chul Park, Natalia B. Shustova Prof. Dr.

Faculty Publications

The advances made in the field of stimuli-responsive catalysis during the last five years with a focus on the novel recently-emerged directions and applications have been surveyed. Metal-free catalysts and organometallic complexes, as well as biomimetic systems and extended structures, which display switchable catalytic activity for a variety of organic transformations, are discussed. Light-activated systems comprised of photochromic molecules capable of modulating reaction rate, yield, or enantioselectivity based on geometric and electronic changes associated with photoisomerization are the focus of the detailed discussion. Alternative stimuli, including pH and temperature, which could be applied either alone or in combination with light, …

Increased Efficiency Of A Functional Sod Mimic Achieved With Pyridine Modification On A Pyclen-Based Copper(Ii) Complex, Magy A. Mekhail, Katherine J. Smith, David M. Freire, Kristof Pota, Nam Nguyen, Marianne E. Burnett, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A series of Cu(II) complexes with the formula [Cu^RPyN₃]²⁺ varying in substitution on the pyridine ring were investigated as superoxide dismutase (SOD) mimics to identify the most efficient reaction rates produced by a synthetic, water-soluble copper-based SOD mimic reported to date. The resulting Cu(II) complexes were characterized by X-ray diffraction analysis, UV–visible spectroscopy, cyclic voltammetry, and metal-binding (log β) affinities. Unique to this approach, the modifications to the pyridine ring of the PyN₃ parent system tune the redox potential while exhibiting high binding stabilities without changing the coordination environment of the metal complex within …

Application Of The Recitation Method To Improve The Competence Of Medical Laboratory Technology Students In The Immunology Field, Patricia Gita Naully, Perdina Nursidika

Jurnal Pendidikan Sains

An accredited mid-level MLT (Medical Laboratory Technology) must have the competence to perform medical laboratory examinations from pre-analytic, analytic, and post-analytic stages in several fields, one of which is immunology. Many D3 MLT students are facing obstacles to passed the immunology course. This obstacle is not only experienced by students of D3 MLT but also by medical students, pharmacy students, and similar majors. The purpose of this research is to determine the effect of recitation method in the form of animation video making and immunology based device on the competence of Diploma 3 (D3) MLT students. This research is a …

Using Augmented Reality For Geometry Learning: Indonesian Elementary School Teachers' Experiences, Asep Nuryadin, Karlimah Karlimah, Dindin Abdul Muiz Lidinillah, Ika Fitri Apriani, Ikairn Rachmawati Putri, Lilis Susilawati, Ginna Islamiati, Dede Nurhidayah

Jurnal Pendidikan Sains

This study aims to discover Indonesian elementary school teachers' experiences (n = 257) of using Augmented Reality (AR) for learning, especially related to one of the topics in mathematics learning, namely, geometry. AR is considered to be an alternative instructional media that can be utilized for teaching geometry, including the topic of three-dimensional shapes. A questionnaire consisting of both close-ended and open-ended questions was used to collect data in this study. This study has successfully revealed teachers' use of digital instructional media during the COVID-19 pandemic, their familiarity with AR, frequency of AR use for geometry learning, and challenges in …

Epistemological Obstacles Of Students In Accomplishing Hots Tests According To Field-Dependent Cognitive Style, Widi Candika Pakaya, Fattah Hanurawan

Jurnal Pendidikan Sains

The main goal of this study is to describe the epistemological obstacles faced by students with field-dependent cognitive styles when attempting to solve HOTS questions. This study uses a qualitative-descriptive methodology. The instruments used are cognitive style tests and HOTS questions. Data is collected through interviews and student work. The research subjects were two participants in third-semester PGSD students at Universitas Negeri Gorontalo. In this study, the data were analyzed by identifying the answers of two respondents to the indicators of epistemological barriers that had been done by the students and then interviewing the respondents. The results of this study …