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Recyclable Composites Prepared From Animal Coproducts And Industrial Waste Sulfur, Perla Y. Sauceda-Oloño

All Dissertations

Pursuing sustainable and environmentally friendly materials has become a significant objective in materials science, particularly flame retardants and construction materials. This dissertation explores the development and evaluation of novel composites and high sulfur-content materials (HSMs) as potential alternatives to conventional, environmentally harmful materials.

Chapter one reviews recent advancements in environmentally benign flame-retardant additives, highlighting the potential of bio-derived phenols, polysaccharide derivatives, and greener phosphorus sources. The review discusses how green additives can enhance the flame retardancy, thermal stability, and smoke suppression properties of various polymers while addressing the challenges and future directions in the field.

Chapter two investigates the production …

Comparison Of Autoclaving And Γ-Radiation Impact On Four Spices Aroma Profiles And Microbial Load Using Hs-Spme Gc–Ms And Chemometric Tools, Mostafa H. Baky, Nora M. Elkenawy, Heba A.S. El-Nashar, Bishoy Abib, Mohamed A. Farag

Faculty Journal Articles

Herbal spices are widely consumed as food additives owing to their distinct aroma and taste as well as a myriad of economic and health value. The aroma profile of four major spices including bay leaf, black pepper, capsicum, and fennel was tested using HS-SPME/GC–MS and in response to the most widely used spices´ processing methods including autoclaving and γ-radiation at low and high doses. Additionally, the impact of processing on microbial contamination of spices was tested using total aerobic count. GC–MS analysis led to the identification of 22 volatiles in bay leaf, 34 in black pepper, 23 in capsicum, and …

Co2 Capture Utilizing Novel Deep Eutectic Solvents: Modeling, Process Simulation, And Cost Analysis, Nazneen Aspi Kolah

Masters Theses

One of the most pressing global issues that humans face is climate change caused by anthropogenic greenhouse gas emissions, especially carbon dioxide (CO2). Conventional solvents utilized for CO₂ capture, such as amines, are widely used in industrial applications due to their high CO2 absorption capacity. However, deep eutectic solvents (DES) have attracted a lot of academic attention recently due to their biodegradability and low energy for regeneration.

This research serves as a foundational proof-of-concept for using DESs in industrial gas separation processes. Five DES are evaluated for CO2 removal from flue gases. Aspen Plus is utilized to simulate the performance …

Phytoplankton Responses To Changing Irradiance And Carbon Fertilization, Alison Siersma

Graduate Theses and Dissertations (2019 - present)

Phytoplankton play a crucial role in marine ecosystems due to their innate ability to fix carbon. As atmospheric CO2 levels continue to rise from fossil fuel combustion, the resulting increase in dissolved CO2 and the concurrent decrease in ocean pH are likely to impact the phytoplankton community. The response of phytoplankton to elevated CO2 can vary significantly among species and environmental conditions (e.g. light, temperature, nutrient availability). To address these variations, an experiment was conducted using a controlled photobioreactor system, maintaining high and low light, constant temperature, nutrient levels, and two pCO2 concentrations. This study focused on two regionally relevant …

Rare Variants Of Dna Ligase 1 Show Distinct Mechanisms Of Deficiency, Jenna H. Veenstra, Alexandria Chabez, Terrance J. Haanen Iii, Austin Keranen, Charlotte Cunningham-Rundles, Patrick J. O'Brien

Faculty Work Comprehensive List

Human DNA ligase 1 (LIG1) performs the final step in DNA repair and recombination pathways by sealing DNA breaks, and it functions as the main replicative ligase. Hypomorphic LIG1 variants R771W and R641L cause immune deficiencies in LIG1 Syndrome patients. In vitro these LIG1 variants have decreased catalytic efficiency and increased abortive ligation and it is not known if either biochemical defect is sufficient on its own to cause immune deficiency. We investigated the enzymatic activity of several new candidate LIG1 Syndrome variants chosen based on their structural proximity to known clinical variants, low minor allele frequency (MAF), high level …

Synthesis Of Novel Chromenone Esters For Biochemical Assays, Andrew Dean Helmerich

Undergraduate Honors Thesis Collection

This project details the synthesis of a variety of novel chromenone esters to be used as enzymatic probes. A robust, initial library of 22 chromenone esters was successfully synthesized with differences in chain length, branching, and the incorporation of cyclic and heteroatomic moieties. These new chromenones were fully characterized by 1HNMR, 13CNMR, DEPT HRMS, 19FNMR, and HSQC. The utility of these compounds comes from the fact that they will fluoresce upon cleavage of the ester; thus, this property makes them ideal candidates to be used in the monitoring of enzymatic activity of esterases. Elucidating the enzyme-substrate structure activity relationship (SAR) …

Impact Of Water Ionic Chemistry On Kombucha Fermentation, Katherine A. Thompson-Witrick, Olivia Sundman, Sadie Disselkoen, Nicholas Hanson, Cheyenne Butler, Victoria Jordan, Ian Galbraith, Jada Spake, Seiler Pollock, Drew M. Budner

Chemistry

Kombucha is made by using a symbiotic culture of bacteria and yeast (SCOBY) to ferment sweetened tea. This fermentation produces a beverage with a unique aroma and acidic flavor. Kombucha has recently gained popularity in the United States and has been reported to have numerous health benefits. While there is a wide variation in kombucha composition, little is known about the impact water’s chemistry has on the fermentation and the resulting kombucha. Brewing water for kombucha was altered using the following ions: bicarbonate, chloride, calcium, magnesium, and sulfate at different concentrations. Pre-(tea) and post-(kombucha) fermentation (kombucha) products were analyzed for …

Use Of Equine H3n8 Hemagglutinin As A Broadly Protective Influenza Vaccine Immunogen, David Verhoeven, Brett A. Sponseller, James E. Crowe, Sandhya Bangaru, Richard J. Webby, Brian M. Lee

Chemistry

Development of an efficacious universal influenza vaccines remains a long-sought goal. Current vaccines have shortfalls such as mid/low efficacy and needing yearly strain revisions to account for viral drift/shift. Horses undergo bi-annual vaccines for the H3N8 equine influenza virus, and surveillance of sera from vaccinees demonstrated very broad reactivity and neutralization to many influenza strains. Subsequently, vaccinating mice using the equine A/Kentucky/1/1991 strain or recombinant hemagglutinin (HA) induced similar broadly reactive and neutralizing antibodies to seasonal and high pathogenicity avian influenza strains. Challenge of vaccinated mice protected from lethal virus challenges across H1N1 and H3N2 strains. This protection correlated with …

Theoretical Investigation Of Hydrogen Abstraction From Fluorinated Propanones And Fluorinated Propanals, Laurel Washburn

Honors Theses

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of industrially used compounds often called “forever” chemicals because of their slow degradation process that leads to accumulation in soil, dust, drinking water, and the body. PFAS are used for their grease and water resistance properties but some of these compounds are toxic at extremely low levels. To better understand the effects of these types of compounds, the main pathways of their degradation need to be further investigated. This study analyzes computationally the hydrogen abstraction reactions by both hydroxyl radical and triplet oxygen atom for all possible fluorinated propanones and …

Investigation Of Magnesium-Potassium Phosphates As Potential Nuclear Waste Form For The Immobilization Of Minor Actinides, Hans Conrad Zur Loye, Petr Vecernik, Monika Kiselova, Vlastislav Kašpar, Hana Korenkova, Vlastimil Miller, Petr Bezdicka, Jan Šubrt, Natalija Murafa, Volodymyr Shkuropatenko, Sergey Sayenko

Faculty Publications

Several recent studies have evaluated technologies of spent nuclear fuel processing specifically for solidifying transuranic (TRU) waste as a by-product of fission. Of the TRU group, plutonium and the minor actinides will be responsible for the bulk of the radiotoxicity and heat generation of spent nuclear fuel in the long term (300 to 20,000 years). In this study, we investigated magnesium potassium phosphate (MKP)-based compounds as host waste forms for the encapsulation of inactive trivalent Nd and Sm as analogues of the minor trivalent actinides, Am and Cm. Waste forms were fabricated under ambient atmospheric conditions by adding 5 wt.% …

Composites Developed By The Reaction Of Elemental Sulfur With Biologically Derived Fats And Oils, Katelyn Tisdale

All Dissertations

Human civilization’s modern infrastructure relies mainly on cement and petrochemical products. However, the production of these building materials have harmful ecological effects such as green gas emissions, therefore intensifying the need to develop alternative, sustainable structural materials from renewably sourced or waste material precursors. The work presented herein investigates various biomass derived resources that serve as the olefin source for reaction with elemental sulfur, another abundant waste source, via inverse vulcanization to form high strength composites competitive with that of traditional building materials.

Chapter one reviews various techniques that have been developed and executed in an effort towards lignin valorization …

Influence Of Glycopolymer Structure On Amphiphilic, Hybrid, Linear Branched Block Copolymer Properties For Use In Biomedical Applications, Kevin Green

Dissertations

The focus of this dissertation is evaluating and adding fundamental knowledge regarding the structure-property relations of glycopolymers used in the design of hybrid block copolymers (HBC) that are cable of self-assembling into delivery vehicles for biomedical applications. A shift to the utilization of natural materials in the design and fabrication of drug-delivery vehicles has garnered significant attention. Understanding the effects of linear glycopolymers content and composition on the resulting HBCs properties can provide valuable insight into how these materials may be tailored for use in targeted biological applications.

The first chapter introduces current literature on the need for improvement in …

Aars Online: A Collaborative Database On The Structure, Function, And Evolution Of The Aminoacyl-Trna Synthetases, Jordan Douglas, Haissi Cui, John J. Perona, Oscar Vargas-Rodriguez, Henna Tyynismaa, Claudia Alvarez Carreno, Jiqiang Ling, Lluis Ribas De Pouplana, Xiang-Lei Yang, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

The aminoacyl-tRNA synthetases (aaRS) are a large group of enzymes that implement the genetic code in all known biological systems. They attach amino acids to their cognate tRNAs, moonlight in various translational and non-translational activities beyond aminoacylation, and are linked to many genetic disorders. The aaRS have a subtle ontology characterized by structural and functional idiosyncrasies that vary from organism to organism, and protein to protein. Across the tree of life, the 22 coded amino acids are handled by 16 evolutionary families of Class I aaRS and 21 families of Class II aaRS. We introduce AARS Online, an interactive Wikipedia-like …

Insights From Diverse Environments: Investigating The Fate And Transport Of Semivolatile Organic Contaminants In Alpine, Arctic, And Arid Regions, Jeffrey Perala-Dewey

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation investigates the fate and transport of pollutants through four field-based studies in a diverse array of environments. These pollutants travel through the atmosphere and end up in places far from their original sources. In this work I explore how chemical properties of the pollutants and the environmental processes that are present change the way the pollutants travel through the environment. In the first study, pollutants from car engines were quantified in the vegetation along transects in three alpine valleys. Using these measurements, I investigated how the chemical properties of the pollutants impacted their interplay with wind systems in …

Cellulose–Starch Composite Aerogels As Thermal Superinsulating Materials, Safoura Ahmadzadeh, Angelina Sagardui, David Huitink, Jingyi Chen, Ali Ubeyitogullari

Chemistry & Biochemistry Faculty Publications and Presentations

The demand for sustainable packaging materials is rapidly increasing due to growing environmental concerns over the impact of plastic waste. In this study, biodegradable, porous, lightweight, and high-surface-area microcrystalline cellulose–starch (MCC-S) hybrid aerogels were synthesized via supercritical carbon dioxide (SC–CO₂) drying. The samples were generated using five different MCC-S weight ratios and characterized for their morphology, crystallinity, and structural and thermal properties. When MCC and S were used together, aerogels with superior properties were obtained compared to those made from each component individually. Specifically, the 1:2 MCC-S aerogel exhibited the highest porosity (97%), the lowest density (0.058 g/cm …

Understanding Defect Dynamics In Black Phosphorene Under Noble Gas Ion Irradiation., Saransh Gupta

Electronic Theses and Dissertations

Controlled introduction of defects in phosphorene using high-energy ion beams offers a promising route to design novel high-performance materials for energy technologies. However, this potential remains underexplored due to a lack of fundamental understanding of the atomic-scale mechanisms governing the production, accumulation, and temporal evolution of defects during ion irradiation. Here, we employ a combination of classical and ab initio molecular dynamics simulations to elucidate the effects of ion energy, angle of incidence, noble gas ion size/mass, and fluence on (a) defect generation (i.e., point defects, topological imperfections, voids), (b) atomic-scale mechanisms of defect formation and re-arrangement, and (c) defect …

Density Functional Theory And Machine Learning Analysis Of C—C Reductive Coupling From Terminal Cyanido And Cyaphido Complexes, Roberto Magdiel Escobar

Theses and Dissertations

Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals and industrial chemistry. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations using the Gaussian16 package to elucidate and compare …

Assessing Reproducibility Challenges In Clinical Metabolics, Darcy Lin Cochran

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Current metabolomics research is expanding to be multiplatform and interdisciplinary. Metabolomic analysis has the potential to provide detailed insight into any biological system of interest to analyze the underlying molecular mechanisms of variables like environment, disease, and genetics. Human clinical metabolomics is a major research area that is often focused on finding biomarkers or panels of biomarkers for different diseases. However, results are difficult to compare across different laboratories since the field of metabolomics has yet to widely adopt best practices for sample preparation, data acquisition and data processing, results are difficult to compare across different laboratories.

This thesis focuses …

Ai Is A Viable Alternative To High Throughput Screening: A 318-Target Study, Izhar Wallach, Denzil Bernard, Kong Nguyen, Gregory Ho, Adrian Morrison, Adrian Stecula, Andreana Rosnik, Ann Marie O'Sullivan, Aram Davtyan, Ben Samudio, Bill Thomas, Brad Worley, Brittany Butler, Christian Laggner

Chemistry Faculty Research & Creative Works

High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, …

Development Of Uranium Fluoride Microstructures, Harry Jang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Uranium microstructured materials with controlled size and shape have found applications in several branches of the nuclear industry including as targets for medical isotopes production, fuels for nuclear reactors, standards for analytical measurements, and energy sources for space exploration. Morphological studies of actinide materials are also highly relevant to nuclear forensics-related work. Other potential applications include information storage, catalysis, sensors, and luminescent devices. Most studies on uranium microstructured materials have focused on binary oxides, nitrides, carbides, and fluorides, with the spherical shape being the dominant morphology. Prior to the work reported in this dissertation, aside from UF4 microspheres (ms) and …

Evaluation Of Polymerization Condition Reactions Of Methyl Vinyl Ketone For Hydrogen Storage, Rituborna Ghosh

Theses and Dissertations

Hydrogen is widely regarded as one of the most promising clean alternative fuel sources; however, its widespread adoption has been hindered by significant challenges related to storage and transportation. Various storage methods have been proposed and developed, with continuous advancements being made to address these issues. Among the most effective solutions is the utilization of polymers, which serve as safe and efficient hydrogen storage media. This work investigated the polymerization of methyl vinyl ketone using different ratio of monomer: initiator and monomer: crosslinker using N,N′-methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator in a free radical polymerization mechanism. …

Physicochemical Property Effects On Immune Modulating Polymeric Nanoparticles: Potential Applications In Spinal Cord Injury, Daniel J. Kolpek, Jaechang Kim, Hisham Mohammed, John C. Gensel, Jonghyuck Park

Markey Cancer Center Faculty Publications

Nanoparticles (NPs) offer promising potential as therapeutic agents for inflammation-related diseases, owing to their capabilities in drug delivery and immune modulation. In preclinical studies focusing on spinal cord injury (SCI), polymeric NPs have demonstrated the ability to reprogram innate immune cells. This reprogramming results in redirecting immune cells away from the injury site, downregulating pro-inflammatory signaling, and promoting a regenerative environment post-injury. However, to fully understand the mechanisms driving these effects and maximize therapeutic efficacy, it is crucial to assess NP interactions with innate immune cells. This review examines how the physicochemical properties of polymeric NPs influence their modulation of …

Unraveling Phytosulfokine Trafficking In Arabidopsis Thaliana Using Fiber-Optic Fluorescence Microscopy, Issaka Obuaba

Electronic Theses and Dissertations

As sessile organisms, plants manage stress through complex signaling networks involving phytohormones such as phytosulfokine (PSK). PSK, a disulfated pentapeptide, regulates plant growth, development, and stress responses by interacting with specific PSK receptors (PSKRs). In this study, we explored the trafficking dynamics of PSK, its post-application fate, and the synthesis of an analog. We administered both native PSK and a fluorescent version tagged with TAMRA (5(6)-carboxytetramethylrhodamine) to various Arabidopsis thaliana genotypes, including wild type, a PSKR-deficient mutant, and a strain overexpressing PSKR1 tagged with green fluorescent protein (GFP) over the wild-type background. Fiber-optic fluorescence microscopy revealed that receptor presence influences …

Investigating Phytosulfokine Trafficking: Insights Into The Role Of Phytohormones In Plant Signaling, Martin Tindi

Electronic Theses and Dissertations

Phytosulfokine is a critical signaling peptide involved in plant growth, development, and stress responses. This thesis investigates the trafficking mechanisms of Phytosulfokine (PSK) in Arabidopsis thaliana, employing fluorescently labelled PSK for non-destructive imaging using a custom-built fiber-optic fluorescence microscope. The study aims to determine the mobility and fate of PSK in plant tissues. Experimental results reveal the short-range and long-range movement of PSK across leaves. Additionally, the project highlights the optimization of non-destructive imaging techniques and the synthesis of caged dexamethasone to facilitate optogenetic studies. These findings provide new insights into PSK trafficking mechanisms in plants, enhancing our understanding …

Experimental Evaluation Of A Recrosslinkable Co2-Resistant Micro-Sized Preformed Particle Gel For Co2 Sweep Efficiency Improvement In Reservoirs With Super-K Channels, Adel Alotibi, Tao Song, Ali Al Brahim, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A recross linkable CO₂-resistant branched preformed particle gel (CO₂-BRPPG) was developed for controlling CO₂ injection conformance, particularly in reservoirs with super-permeable channels. Previous work focused on a millimeter-sized CO₂-BRPPG in open fractures, but its performance in high-permeability channels with pore throat networks remained unexplored. This study used a sand pack model to evaluate a micro-sized CO₂-BRPPG under varying conditions of salinity, gel concentration, and pH. at ambient conditions, the equilibrium swelling ratio (ESR) of the gel reached 76 times its original size. This ratio decreased with increasing salinity but remained stable …

Machine Learning Optimized Depolymerization Of Pet (Polyethylene Terephthalate) Via Glycolysis, Mehwash Aamir

Theses and Dissertations

Over 90% of the approximately 1 million PET bottles sold every minute end up in landfills or oceans, where they can persist for centuries. Plastic pollution urgently needs sustainable management and recycling solutions to mitigate the environmental impact of PET waste. From all techniques to recycle plastic waste, catalytic glycolysis stands out for its rapid reaction time, high monomer yields, lower costs, and enhanced durability.

In this work glycolysis of PET was evaluated under microwave conditions using 1,5,7-Triazabicyclo [4.4.0] dec5-ene (TBD) and 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU) as catalysts, being DBU as the best catalyst for further analysis. The effect of …

The Application Of High-Resolution Mass Spectrometry For The Analysis Of Biopolymers, Metabolites, And Biologically Relevant Small Molecules, Christ Duc Tran

Graduate Doctoral Dissertations

High-resolution mass spectrometry (HRMS), as its name suggests, possesses high resolving power that enables the separation of ions with very close mass values. This is particularly beneficial for analyzing complex samples where numerous compounds may have similar masses, as it helps prevent signal overlaps and ensures an accurate spectral analysis. The current work explores the diverse applications of high-resolution mass spectrometry in oligonucleotide research, organic synthesis and medicinal chemistry. Oligonucleotide research: Chapters 2-5 present the research results from studies that employed ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) to understand the pharmacokinetics of RNA interference (RNAi) therapeutics. The …

Optimization And Purification Of Magnesium Borides Fabricated By Combustion Synthesis And By High-Temperature Sintering, Miguel Joaquin Camarena

Open Access Theses & Dissertations

Hydrogen as a fuel provides several benefits over the use of fossil fuels; however, one challenge in utilizing hydrogen as an energy carrier revolves around its storage. Achieving sufficient volumetric hydrogen density in a storage solution will facilitate hydrogenâ??s adoption for use in both stationary and mobile applications. Solid-state hydrogen storage provides a promising pathway to solving this problem. However, the hydrogenation of these materials is characterized by slow kinetics and extreme thermodynamic conditions. Magnesium borohydride (Mg(BH4)2) is a promising material in hydrogen storage due to its reversible properties and a theoretical hydrogen capacity of 14.9 wt.%. To synthesize this …

Functionalized Carbon Quantum Dots: A Promising Nanomaterial For Investigating Their Potential In Neurodegenerative Disease Treatment, Sherin M. El Morsy

Open Access Theses & Dissertations

Neurodegenerative diseases such as Parkinson's Disease (PD), Alzheimer's Disease (AD), and Huntington's Disease (HD) remain incurable, despite extensive research into therapeutic development. In the United States of America, the annual cost of PD and AD in terms of patient care and lost productivity is approximately $200 billion. Consequently, there is a critical and unaddressed need for the development of innovative drugs and drug delivery systems that can decelerate, stop, or ideally reverse neurodegenerative diseases. The dissertation presented here focuses on devising strategies to target PD through multiple mechanisms, including the inhibition of protein aggregation and the reduction of oxidative stress. …

Microwave-Assisted Green Synthesis Of Spiroindolinopyranopyrazoles, Esther Owusu

Theses and Dissertations

Green Chemistry, usually known as sustainable chemistry, is widely implemented worldwide to safeguard human health and the environment. Recent investigations in organic synthesis and chemical transformation have demonstrated that green chemistry techniques are significantly reducing both chemical waste and reaction time. In order to fulfill this ecological requirement, it is crucial to lessen the utilization of perilous solvents and noxious chemicals, while also creating innovative reaction methods that decrease the production of trash. The implementation of such methodologies can greatly enhance the field of green chemistry. A more environmentally friendly synthetic method was utilized to generate spiro chemicals and their …