Digital Commons Network^™

Engineering Silicone Magnetic Fluids For Localized Radiation Attenuation During Ocular Melanoma Brachytherapy, Zachary L. Caprow

All Dissertations

Ocular melanoma is commonly treated using plaque brachytherapy; however, radiation-induced damage to healthy ocular tissues frequently results in partial or complete vision loss. This work investigates the development of an injectable, magnetically responsive silicone magnetic fluid designed to localize adjacent to the tumor and attenuate low-energy gamma radiation during treatment.

The material system consists of iron oxide nanoparticles surface-functionalized with a siloxane polymer, in which the nanoparticles provide magnetic responsiveness and radiation attenuation, while the polymer coating ensures colloidal stability, injectability, and biocompatibility. A one-pot synthetic approach was developed wherein a functionalized siloxane polymer containing iron-affinitive groups was reacted with …

Urea-Based Boronium Salts As Antimicrobial Agents, Gabriel Allen Merchant

Honors Theses

Quaternary ammonium compounds (QACs) are widely used in disinfectants due to their ability to inhibit the growth of and eliminate microbes. The potency, broad-spectrum activity, and low cost of QACs have made them a cornerstone of modem hygiene. In recent years, QACs have garnered many health and safety concerns due to their overuse and subsequent accumulation in the environment. The increased use of QACs has further led to an increase in antimicrobial-resistant bacteria, making the synthesis of novel antibacterial compounds vital to combat this growing threat. Recent advances in boronium salts offer a unique alternative to address these adverse effects. …

Structure-Property Relationships In Epoxy/Amine-Derived Polyester Thermosets, Jeffrey Aguinaga

Dissertations

This dissertation relates to ester-containing aromatic epoxy monomers and thermosets formed via reaction of those monomers with either ester-containing or non-ester-containing amine comonomers.  Due to the wide array of potential reactants (many bioderivable) to form ester-containing epoxy monomers that are closely related in structure, fundamental study of structure-property relationships was highly practical for this platform of materials.

Though properties of aromatic epoxy thermosets of relatively high-crosslink density and network strand rigidity vary widely with chemical composition and architecture, relatively low fracture toughness and impact resistance due to lack of ductility are typical. Integration of ester functionality and aliphatic spacers/connectors for …

Exploring The Effects Of Polymer-Graphene Interactions On Bulk Composite Properties Using Finite Element Analysis, Bryant Grove

Dissertations

As a filler in high performance materials, graphene significantly enhances the mechanical properties of polymer composites. Experimental characterization of graphene composite enhancements is limited by labor-intensive processes in both synthesizing composites for different purposes and in characterizing the interactions between graphene and polymer composites that lead to these enhancements. Computational approaches such as finite element analysis (FEA) are suitable alternatives that go beyond experimental analysis. This dissertation demonstrates the utility of FEA in analyzing polymer graphene composites with an emphasis on modeling the interaction between graphene fillers and the matrix within the interphase formed between them. The accessible design framework …

Advancement In Electrochemical Generation-Collection: Snapshot Redox Cycling Voltammetry For Rapid Analysis At Chip-Based, Individually Addressable Microband Electrode Arrays, Blake Aleck Sterling

Graduate Theses and Dissertations

Snapshot redox cycling voltammetry (Snapshot RCV) is introduced as a rapid electrochemical technique that reconstructs the current-potential profile of a redox active species using a microband electrode array. By simultaneously biasing individual generator electrodes alternating in the array to different voltages across the analyte’s potential range while individually holding collector electrodes at a reversing potential, “spatial” voltammetry is achieved in as little as 1 s with the temporal speed of chronoamperometry, rapidly capturing the steady-state redox cycling (RC) profiles. During RC (a mode of generation-collection), the analyte is oxidized (or reduced) at generator electrodes and converted back at neighboring collector …

College Of Natural Sciences Spring Newsletter, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

[Page 1] Dean's Message
[Page] 2 Awards & Recognitions // Student Spotlights
[Page] 3 Zhang Named to Landsat Science Team // The Power of Teaching
[Page] 4 “Science as Art” Competition Welcomes High School Artists
[Page] 5 Testing for “Forever Chemicals” in Surface Water // New Faculty Spotlight
[Page] 6 Ambassador Initiated Outreach
[Page] 7 57th Annual Geography Convention
[Page] 8 Twice the Impact on On Call with the Prairie Doc
[Page] 9 Making Staple Foods Healthier // Halaweish & Cole-Dai Retire
[Page] 10 Drone Day 2026
[Page] 11 Student Research, Scholarship, and Creative Activity Day (SRSCAD)
[Page] 12 Ceremony …

Comparative Development Of Mof‑Based And Mof‑Free Agnp Functionalized Zno Nanorod–Cotton Fabric Composites For Photocatalytic Applications, Md Al Mamun

Master's Theses

Photocatalysis offers a cost‑effective and environmentally friendly strategy for degrading organic pollutants and addressing energy and environmental challenges. This study initially explored MOF‑based cotton‑fabric‑supported ZnO nanorod composites but found that the MOF component primarily acted as an adsorbent rather than an effective photocatalyst. Consequently, MOF‑free composites were developed by directly growing ZnO nanorods on cotton fabric and functionalizing them with silver nanoparticles. Photocatalytic testing revealed that AgNP‑modified ZnO nanorods, particularly at 10 mM AgNP, exhibited superior dye degradation efficiency, thereby demonstrating a scalable and effective photocatalytic platform.

Synthesis Of Novel 1,2,3-Triarylnaphthalenes Via Intermolecular Dehydro-Diels-Alder Reaction, Ethan C. Dailey

Honors Theses

The photo-dehydro-Diels–Alder (PDDA) reaction is a useful method for the construction of substituted naphthalene derivatives from acyclic precursors. While intramolecular variants of this transformation are well established, intermolecular PDDA reactions remain rare due to challenges associated with controlling reactivity under photochemical conditions. Previous studies suggest that electron-withdrawing substituents can promote intermolecular cycloaddition by increasing alkyne polarization and stabilizing reactive intermediates. In this work, the effect of enhanced electron-withdrawing character on intermolecular PDDA reactivity was investigated through the incorporation of a 2,3,5,6-tetrafluoropyridinyl substituent. Corresponding alkyne substrates were synthesized and subjected to photochemical conditions, resulting in the formation of 1,2,3-triarylnaphthalene products. The …

Insights Into Androgen Receptor Allosteric Modulation By P,P'-Dichlorodiphenyldichloroethylene Binding At The Binding Function-3 Site And Site-Specific Binding Function-3 Mutations, Emanuel Aggeo Flores

Theses and Dissertations

One of DDT’s metabolites, p,p’-dichlorodiphenyldichloroethylene (DDE), has been classified as an endocrine disrupting chemical (EDC) due to its ability to interfere with hormone signaling by binding to nuclear receptors (NR) such as the androgen receptor (AR).

Structurally, the AR contains a ligand-binding domain (LBD) where endogenous steroids bind. Furthermore, the LBD contains a surface binding site known as binding function-3 (BF-3), which studies suggest exerts an allosteric effect on bound DHT when small, hydrophobic molecules bind.

Here, we present a study that examines how specific BF-3 site mutations and DDE binding affect steroid stability within the LBP utilizing computational methods. …

Rhodium On Alumina Catalyzed Hydrodechlorination Of Trichlorethylene, Amber Krueger, Gage Mueller

Celebrating Scholarship and Creativity Day (2018-)

Chlorinated ethylenes are common groundwater contaminants that persist in the environment and pose significant risks to human health such as damage to the nervous system, liver, kidneys, and even increased risk of cancer. Catalytic dehydrochlorination has emerged as a promising strategy for detoxifying compounds such as trichloroethylene (TCE). This study investigates whether rhodium on alumina (Rh/Al₂O₃) in the presence of hydrogen gas can completely degrade TCE to non-toxic products without the accumulation of harmful chlorinated intermediates. While palladium catalysts have been widely studied for dehydrochlorination, the activity and mechanism of rhodium supported on alumina in aqueous systems remains less characterized. …

Multiplexing Reductive Alkylation Of Peptides For Quantitative Proteomics, Kevin C. Souza

Honors Scholar Theses

Reductive alkylation is a robust and commonly used labeling technique for quantifying proteins and peptides in complex samples using mass spectrometry. This technique involves the attachment of alkyl groups to an amino group at the N-terminus and lysine residues of a peptide, causing a mass shift that is detectable using mass spectrometry. This work aims to explore the application of reductive alkyl labeling in multiplexed quantitative proteomics. The first part of the study investigates the effectiveness of the labeling of peptides using a variety of aldehydes via reductive alkylation. The aldehydes were chosen, such that they provided various degrees of …

Reversible, Light-Controlled Inhibition Of Stim1-Mediated Calcium Signaling Using Photoswitchable Ml-9 Derivatives In Jurkat-Lucia Nfat Reporter T Cells, José L. Matute Gálvez

Honors Scholar Theses

Store-operated calcium entry (SOCE) through calcium release-activated

calcium (CRAC) channels is the dominant pathway for sustained Ca2+ influx in

non-excitable cells and is essential for T cell activation, driving downstream

signaling through the calcineurin-NFAT transcriptional axis. Dysregulation of

SOCE produces multi-systemic disease phenotypes, establishing that precise,

spatiotemporally controlled modulation of this pathway is a fundamental

therapeutic requirement. ML-9 is one of the only characterized small molecules

capable of targeting SOCE upstream at the level of STIM1 localization, but lacks

the selectivity, pharmacokinetic properties, and spatiotemporal control necessary

for therapeutic development.

This work describes the design, synthesis, and biological evaluation of …

General Chemistry Students' Perceptions Of How Various Course Resources Affect Their Learning And Exam Preparation, Jennifer Scoggin Cortez

Theses and Dissertations

The tertiary-level first-semester general chemistry course has a large range of material with different complexities that can be difficult for students to master within one semester. In the general chemistry I course under study here, students were provided with a variety of resources to help with their learning and understanding, with various components of the course, including the lecture, online textbook, Peer-Led-Team-Learning (PLTL) study sessions, and exams, having associated resources. This study aims to analyze students’ experiences with these various resources. Students were given semi-structured interviews where they talked about their experiences with the resources and provided insight into more …

Probing The Dynamic Behavior Of The Androgen Receptor In The Presence Of Heptyl And Methyl Parabens, Edgardo De Leon

Theses and Dissertations

The androgen receptor (AR) mediates physiological signaling from endogenous androgens, a function that can be disrupted by endocrine disruptors with serious reproductive and developmental consequences. Parabens, widely used preservatives, inhibit AR signaling in cell-based assays, with inhibitory potency correlating with alkyl chain length: heptylparaben exhibits stronger antagonism than methylparaben, which shows no effect. We hypothesize this differential potency arises from allosteric modulation at the AR Binding Function 3 (BF-3) site, altering dihydrotestosterone (DHT) binding dynamics. Docking calculations using antagonist-bound AR crystal structures, followed by molecular dynamics simulations, show that methylparaben fails to remain bound at BF-3, whereas heptylparaben maintains stable …

Structure–Property Engineering Of Sn-Based Hybrid Perovskites Via Bulky Organic Cation Incorporation: From 3d To 2d Architectures, Kevin Alejandro

Theses and Dissertations

This thesis investigates tin-based hybrid organic/inorganic perovskites (HOIPs) as a lead-free alternative to silicon solar cells. To manipulate optoelectronic and efficiency of the semiconductors, methylammonium was substituted with bulky propylammonium and tetrabutylammonium cations to induce quasi-2D/3D Ruddlesden-Popper phases. X-Ray Diffraction confirmed 2D layered phases in propylammonium hybrids (5-15%), while tetrabutylammonium hybrids faced steric limits, triggering vacancy ordered perovskite phases at 1% concentration. Optical analysis showed a bandgap narrowing from 1.30 eV to 1.26 eV with increased substitution. Although photovoltaic performance generally declined, the 10% propylammonium hybrid achieved the highest fill factor of ~0.79, indicating superior internal charge transport. This work …

Stability Of Paraffin-Insulated Nitrogen-Doped Carbon Fiber Ultramicroelectrodes, Maxwell H. Kwakwah

Electronic Theses and Dissertations

Nitrogen-doped carbon materials can facilitate the reduction oxygen-oxygen bonds, a key step in electroreduction of both O₂ (an important reaction in energy applications) and H₂O₂ (an important reaction in sensing and biosensing). Our lab previously demonstrated that thermal decomposition of urea in the presence of carbon fiber (CF) results in an N-doped carbon material that exhibits good electrocatalytic properties for H₂O₂ reduction. However, previous methods of insulating single N-doped CF via laser heating of borosilicate capillaries and epoxy to prepare ultramicroelectrodes (UMEs) seemed to adversely affect surface nitrogen contents and electrocatalytic properties. More recent work that utilized paraffin to …

Adsorption Of Pfas On Bridged Functionalized Organosilica Materials, Elisha Lawerh Kabutey

Electronic Theses and Dissertations

PFAS are hazardous contaminants that have a devastating impact on human health and the environment. Their hazardous nature has led to the development of various adsorption methods for removing these contaminants from water sources. In this study, functionalized organosilica materials were synthesized from bis[3-(trimethoxysilyl)propyl] amine using the sol-gel method. The surface amino groups of the organosilica were converted into amine hydrochloride groups. Their adsorption properties were evaluated using salts of perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorobutanesulfonic acid. Results showed excellent adsorption capacity of the materials. Adsorption of PFAS leads to particle agglomeration and flotation of the spent material. A column …

Isolation, Purification, And Characterization Of Α-Galactosidase From Watermelon (Citrullus Lanatus), Christopher Henley Jr.

Chemistry & Biochemistry Undergraduate Honors Theses

The enzyme α-galactosidase is a type of glycosidase that removes galactose sugar units from larger molecules in cells. Compounds that inhibit glycosidases have been useful for understanding the structure and function of the enzymes they inhibit, and some have been used to treat certain diseases. Using inhibitors of α-galactosidase to study its characteristics and mechanisms may provide insights into its role in disease and its general utility. Advances in fields such as agriculture, sustainable fuels, and biomedicine may be facilitated by inhibition studies of α-galactosidase, but the current library of known inhibitors is relatively lacking. Obtaining α-galactosidase enzymes from chemical …

Tunable Physical Color In Nanostructured Materials: Exploring Reversible Mechanisms For Active Optical Control, Matt Hughes

Chemistry & Biochemistry Undergraduate Honors Theses

Vanadium Dioxide (VO₂) thin films have been grown on silicon wafers using atomic layer deposition of TDMAV (tetrakis(dimethylamino)vanadium(IV)) and H₂O as precursors. A quartz crystal microbalance (QCM) measurement was used during deposition to confirm growth and resulted in a growth rate of approximately 0.6 Angstroms/cycle. X-Ray Reflectivity (XRR) was performed to confirm growth thickness and reported an approximately 30 nm thin film after 500 cycles of TDMAV precursor deposition. X-Ray photoelectron spectroscopy was utilized to determine the phase of the vanadium samples and confirmed the presence of vanadium dioxide as prepared and after annealing under nitrogen …

Energetic Eutectics: An Experimental And Computational Investigation On Explosive Deep Eutectic Solvents, Connor J. Parker

All Theses

This study reports on the incorporation an extreme gradient boosting (XGBoost) machine learning strategy tailored to identifying potential high-energy, insensitive explosive deep eutectic solvents. 1,1-diamino-2,2-dinitroethylene (FOX-7) was investigated as the explosive of interest in our eutectic modeling. The resulting predictions highlighted a wide range of binary compositions demonstrating significant depression from the FOX-7 melting temperature with >70% probabilities of formation. Subsequent computational investigation into select mixtures provided underlying stabilization energies and optimized mixture geometries, which were then assessed experimentally with near simulant compounds oxalyldihydrazide and 1-methyl-3- nitroguanidine replacing FOX-7.

Experimental results with these chosen simulants did not demonstrate classical eutectic …

Membrane Organization Of Rheb And Rhoa: Roles In Function And Allosteric Druggability, Chase M. Hutchins

Dissertations and Theses (Open Access)

Small GTPases of the Ras superfamily are membrane-bound molecular switches that regulate nearly all major cellular processes, and their dysregulation drives cancers, neurological disorders, and metabolic diseases. While anchored to cellular membranes, the catalytic domains of small GTPases undergo orientation dynamics, adopting distinct configurations that can occlude or expose effector-binding surfaces and modulate signaling output. These dynamics have been characterized in the Ras oncoproteins, but whether they extend across the superfamily and influence allosteric druggability has remained unknown.

In this dissertation, I address these questions through Rheb and RhoA, two small GTPases with complementary differences in subfamily lineage, membrane localization, …

Mechanism Of Formation Of Guanine-Guanine Crosslinks As Products Of One-Electron Oxidation Of 1-Methylguanosine In Acidic Medium, Ibrahim Braimah Mr

Electronic Theses and Dissertations

Reactive oxygen species (ROS) from normal metabolism and environmental exposure may cause oxidative DNA damage. Guanine (G) is the most oxidizable nucleobase. One-electron oxidation (OEO) of G in produces guanine radical cation (G•⁺), which deprotonates to form guanyl radical G(-H)•.This radical exists in two tautomeric forms: G(N1-H)• and G(N2-H)•. Dimerization of guanyl radical yields G-G cross-links (D1/D2); a tautomeric form for dimer formation remains elusive. This study presents the first characterization of G• dimerization products from the OEO of 1-MeGuo in acidic medium. Photolysis at 470 nm in the presence of S₂O₈²⁻ and Ru(II)(bpy)₃²⁺ generates two major stereoisomers (D1AW* and …

Hollow Nickel-Iron Nanoshells As Electrocatalysts For The Oxygen Evolution Reaction, Jonathan Batey

Chemistry & Biochemistry Undergraduate Honors Theses

The development of highly active and affordable catalysts for the oxygen evolution reaction is crucial to achieve a future where hydrogen is generated cleanly using renewable methods. Ni-Fe nanocatalysts show great promise in this area, as they are affordable and highly active. However, to overcome the industrial dominance of steam methane reforming, their activity needs improvement. This work aims to increase the activity of Ni-Fe nanocatalysts by making hollow nanostructures. Hollow Ni-Fe nanostructures were synthesized by coating a Cu template with Ni and Fe, followed by the etching of the Cu template. This left hollow Ni-Fe nanoshells, which were used …

Overcoming Glioblastoma Resistance To Temozolomide With New Derivatives: Design, Synthesis, And Mechanistic Studies, Hualin Zhang

Open Access Theses & Dissertations

Glioblastoma multiforme (GBM) is an aggressive brain tumor with rapid progression and poor prognosis. Although temozolomide (TMZ) remains a central component of standard therapy, its clinical benefit is limited and resistance frequently emerges through DNA repair pathways, particularly O6-methylguanine-DNA methyltransferase (MGMT). Because DNA cross-links are generally more difficult to repair than monoalkylated lesions, we hypothesized that TMZ derivatives bearing protein-reactive functionality might generate damage that is less susceptible to MGMT-mediated resistance. Guided by this rationale, we designed a new class of N3-modified TMZ derivatives containing covalent warheads, developed a synthetic route compatible with the chemical instability of the TMZ scaffold, …

Degradation And Metabolic Analysis Of Synthesized Quorum-Sensing Signals By The Model Eukaryote Chlamydomonas Reinhardtii, Adam Josef Bach

Theses and Dissertations

Bacterial organisms can “talk” with one another on a colony-wide scale using a communication system known as quorum-sensing (QS) via chemical signals. These signals are produced at a basal rate throughout the life of the bacteria and are classified as autoinducers, which diffuse across the cell membrane. Once the critical concentration is reached, they begin to diffuse back into the cell and initiate a phenotypic change. As these signals exist outside the membrane of their producer, they are also accessible to other organisms. It has already been noted that some plant species uptake these compounds through their roots and break …

Fret Studies On The Binding Of Fibroblast Growth Factor (Fgf) Proteins To The Hard Corona Of Cuins2-Based Quantum Dots, Colette Robinson

Graduate Theses and Dissertations

Fibroblast Growth Factor (FGF) has been shown to be an important protein in angiogenesis, which is critical in developmental biology and wound healing but has also been implicated in cancer metastasis. FGF interacts with an FGF Receptor (FGFR) to signal the onset of angiogenesis but the detailed mechanism of angiogenesis, and particularly its regulation, is still largely unknown. Imaging the interaction of FGF with FGFR in biologically-relevant environments, such as directly in cells, is key towards furthering this understanding and may eventually aid in the development of better cancer treatments. CuInS2/ZnS quantum dots (QDs) are an attractive fluorescent probe to …

High Throughput Phenomics Pipeline For Pulse Crop Nutritional Breeding, Amod Udayanga Madurapperumage

All Dissertations

Dry pea (Pisum sativum L.), lentil (Lens culinaris Medik.), and chickpea (Cicer arietinum L.) are major pulse crops valued for their high nutritional composition and importance to global food systems. Pulses are rich in carbohydrates, protein, and essential minerals, making them ideal whole foods and critical contributors to food and nutrition security. Due to these advantages, pulse breeding programs are increasingly focusing on enhancing nutritional traits, such as protein quality, amino acid balance, and micronutrient density, through the process of biofortification. However, improvement of agronomic traits remains equally essential. Characteristics such as plant height, standability, stress tolerance, …

Deciphering Chemomechanical Couplings In Proteins Using Molecular Dynamics And Enhanced Sampling Techniques, Matthew Brownd

Graduate Theses and Dissertations

Proteins function through a complex interplay between chemical interactions and mechanical motions across multiple spatial and temporal scales. Understanding how ligand binding, conformational dynamics, and structural flexibility collectively regulate protein function remains one of the central challenges in molecular biophysics. This dissertation presents a computational investigation into chemomechanical coupling in three distinct classes of biomolecular systems using all-atom molecular dynamics (MD) simulations and enhanced sampling methods, with particular emphasis on free-energy calculations and long-timescale conformational analysis. The first part of this work focuses on ligand binding in hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which regulate rhythmic electrical activity in the heart …

Green Synthesis And Characterization Of Carbon Dots From Date Seeds For Antimicrobial Applications, Mariam Rami Hamdan

Theses

This thesis focuses on the synthesis and functionalization of Carbon Dots (CDs) derived from date seeds, followed by their conjugation with different antibiotics for antimicrobial applications. Carbon dots have gained increasing popularity due to their unique optical characteristics, surface properties, and biocompatibility. On the other hand, the utilization of date seeds offers a sustainable route towards obtaining value-added nanomaterials from agricultural waste. The central aim of this project is to develop and characterize CDs from date seeds and investigate their possible use as antibiotic carriers to improve antibacterial efficacy. The CDs were prepared using a green, cost-effective method and characterized …

Taking A Deeper Look: Attributing Tonal Values Of Photolumens To Their Emulsions Using Scanning Electron Microscopy, Anna M. Moore

All Theses

This thesis examines whether tonal variation in photolumens made with historic silver gelatin photographic papers can be linked to differences in elemental composition. Photolumens are cameraless photographic images created by placing objects directly on light-sensitive paper and exposing them to ultraviolet light. Because expired and historic darkroom papers often produce unpredictable colors and tones, this study asks whether visually defined tonal groups also show measurable chemical differences.

Twenty historic paper samples were exposed, documented, and sorted into five tonal groups based on visible image characteristics. Each sample was then analyzed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) …