Chemistry Commons^™

Actinide Behavior In Soft Ligand Environments And Higher Oxidation States Of Neptunium In Aqueous Media With Solid-State Synthesis Of Np(Vii) Compounds, Kelly Floyd Seeley

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fundamental properties of Uranium and Neptunium were investigated with Powder X-Ray Diffraction (PXRD) to study the behavior or 5f electrons with chalcogen, alkali metals, and alkaline earth metals. Two novel compounds were generated: NaCuUS₃ and NaCuNpS₃. There are several crystal structures that form in the family of AMM’Q (A = s-block, M = d-block, M’ = d-block or f-block, and Q = chalcogen), with oxidation states of A¹⁺, M¹⁺, M’⁴⁺, and Q^2- ions from the family of type I compounds. Work was continued to …

Investigation Of The Chemical And Electronic Structure Of A 2h Phase Mos2 Single Crystal, Mary Blankenship

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molybdenum disulfide has a wide range of applications in energy conversion devices, like thin-film solar cells, batteries, bio sensors, and more. Although the properties of MoS2 and other transition metal dichalcogenides (TMDC) have been widely studied, disagreements and discrepancies regarding its electronic structure remain.

In this thesis, a highly-oriented synthetic 2H phase MoS₂ single crystal is investigated using a toolchest of spectroscopic techniques to uncover its chemical and electronic properties. Lab-based x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), inverse photoemission spectroscopy (IPES), and low energy electron diffraction (LEED) were performed at UNLV and combined with resonant inelastic soft …

The Room Temperature Electrolysis Of F-Elements In Aqueous And Ionic Liquid Media: Synthesis, Dissolution, And Reduction, Phillip George Hammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Procuring F-element metals is no simple task and often requires the use of caustic and hazardous materials at high temperatures. These materials are invaluable for a variety of scientific missions ranging from the elucidation of fundamental properties, as fast spectrum nuclear fuel forms, to pit production modernizing our nuclear stockpiles. Metallic actinide materials are essential to strategic and critical materials recovery, the nuclear energy sector, and weapons production. Room temperature electrolysis is envisioned as a process to recover laboratory scale (milligram to gram) quantities of actinide metals. This process closes the uranium chemical loop allowing the reclamation of materials for …

Characterization Of Interlayer Laser Shock Peening During Fused Filament Fabrication Of Polylactic Acid (Pla), Fabien Denise

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The field of additive manufacturing (AM) has gained a significant amount of popularity due to the increasing need for more sustainable manufacturing techniques and the adaptive development of complex product geometries. The problem is that AM parts routinely exhibit flaws or weaknesses that affect functionality or performance. Over the years, surface treatments have been developed to compensate certain flaws or weaknesses in manufactured products. Combining surface treatments with the modularity of additive manufacturing could lead to more adaptable and creative improvements of product functions in the future. The current work evaluates the feasibility of pursuing a new research axis in …

Quantification Of Dye Degradation On Titanium Dioxide-Based Membranes, Elizabeth Carol Wood

Graduate Theses and Dissertations

The purpose of this study was to examine the dye degradation on the titanium dioxide (TiO2)-based membranes. While many studies have shown photocatalytic degradation of dye on TiO2 in solution, few studies have been reported on the solid TiO2 substrate. In this work, a new method is developed to quantify the dye degradation on TiO2-based membranes. A hydrothermal method is used to synthesize the photocatalytic TiO2 nanofibers; vacuum filtration is applied to fabricate a self-assembled membrane. Silver is incorporated into the nanofibers through in situ reduction before vacuum filtration to fabricate Ag/TiO2 membrane in an attempt to red shift the …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

Lif-Sn Composite Modification Layer To Modify Garnet/Lithium Metal Interface, Wu Yang, Xue-Fan Zheng, Yu-Qi Wu, Zheng-Liang Gong

Journal of Electrochemistry

The growing demands for electric vehicles and consumer electronics; as well as the expanding renewable energy storage market; have promoted extensive research on energy storage technologies with low costhigh energy density and safety. Lithium (Li) metal and solid-state electrolytes are considered as important components for next-generation batteries because of their great potential for improvements in energy density and safety performance. Inorganic garnet-type solid electrolytes with high Li-ion conductivity (about 10^-3 S·cm^-1) and high shear modulus (55 GPa) are considered to be ideal solid-state electrolytes; however; the issue of Li dendrite growth still obstructs their practical application. Herein; …

Preparation And Lithium Storage Properties Of Carbon Confined Li3Vo4 Nano Materials, Jia-Qi Fan, Huan-Qiao Song, Jia-Ying An, Amantai A-Yi-Da-Na, Mo Chen

Journal of Electrochemistry

Li₃VO₄, as a promising anode material for lithium ion batteries, has been widely studied because of its low and safe voltage, and large capacity. However, its poor electronic conductivity impedes the practical application of Li₃VO₄ particularly at high rates. In this paper, carbon confined Li₃VO₄ nano materials (Li₃VO₄/C) were synthesized by hydrothermal and solid-phase method, and for comparison, the Li₃VO₄ (N) nano materials without carbon confinement and Li₃VO₄ (B) materials were also synthesized by pure solid-phase method. The composition, structure, …

Peg-Water Electrolyte For High-Performance Zinc Iodine Dual-Ion Batteries, Xiao-Feng Qu, Yu-Ting Tang, Xin-Cheng He, Jia-Sheng Zhou, Zi-Heng Tang, Wen-Hua Feng, Jun Liu

Journal of Electrochemistry

Thanks to abundant resource and rapid redox reaction kinetics, iodine is regarded as promising positive materials inthe batteries. However, the shuttling effect due to the high solubility of iodine in the electrolyte makes the performance of battery poor. In this paper, polyethylene glycol (PEG400) and potassium iodide were added into zinc-ion aqueous electrolyte. PEG400 could complex with iodine to reduce the dissolution of iodine, therefore alleviating the formation of soluble triiodide (I₃^–) from iodine and iodide ions. Furthermore, this electrolyte was used in the battery with double carbon cloths as the current collectors, double separators and zinc …

Constructing Carbon-Encapsulated Nifev-Based Electrocatalysts By Alkoxide-Based Self-Template Method For Oxygen Evolution Reaction, En-Hui Ma, Xu-Po Liu, Tao Shen, De-Li Wang

Journal of Electrochemistry

The development of green and sustainable water-splitting hydrogen production technology is beneficial to reducing the over-reliance on fossil fuels and realizing the strategic goal of "carbon neutral". As one of the half reactions for water splitting, oxygen evolution reaction has suffered the problems of sluggish four-electron transfer process and relatively slow reaction kinetics. Therefore, exploring efficient and stable catalysts for oxygen evolution reaction is of critical importance for water-splitting technology. Metal alkoxides are a series of compounds formed by the coordination function of metal ions with alcohol molecules. Metal alkoxides possess the double advantages of organic materials and inorganic materials, …

Electrospun Ethyl Cellulose Nanofibers With Phase Change Materials: Designing Temperature-Responsive Drug Delivery Systems, Michael Wildy

Theses and Dissertations

In this study, ethyl cellulose (EC) nanofibers loaded with either Rhodamine B (RhB) or Doxorubicin HCl (DOX) and phase change materials (PCM) were fabricated by blend electrospinning. EC is a cellulose derivative widely used as an excipient in the pharmaceutical industry and an ideal polymer for controlled drug release. Lauric acid (LA) and stearic acid (SA) were used as a material with a melting point close to physiological body temperature. Good drug-polymer compatibility and an amorphous distribution of drugs were shown by Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. The release rate of RhB was shown to …

Fluorescent Molecular Rotors As Versatile In Situ Sensors For Protein Quantitation, Kevin Daus, Sorachat Tharamak, Wanchai Pluempanupat, Peter Galie, Maria A Theodoraki, Emmanuel A Theodorakis, Mary Alpaugh

College of Science & Mathematics Departmental Research

Accurate protein quantitation is essential for many cellular mechanistic studies. Existing technology relies on extrinsic sample evaluation that requires significant volumes of sample as well as addition of assay-specific reagents and importantly, is a terminal analysis. This study exploits the unique chemical features of a fluorescent molecular rotor that fluctuates between twisted-to-untwisted states, with a subsequent intensity increase in fluorescence depending on environmental conditions (e.g., viscosity). Here we report the development of a rapid, sensitive in situ protein quantitation method using ARCAM-1, a representative fluorescent molecular rotor that can be employed in both non-terminal and terminal assays.

Investigation Of Electron Transfer In The Ksha-Kshb-R286a Protein Complex From Mycobacterium Tuberculosis, Elyse Tavares

Honors Program Theses and Projects

With drug-resistant bacteria such as Mycobacterium tuberculosis being a serious public health problem, infected individuals have minimal treatment options. By investigating the electron transfer within 3-ketosteroid-9��-hydroxylase (KshAB), a protein involved in the energy production pathway of this bacteria, it will allow for potential inhibitors of this enzyme to be designed as antibiotics against tuberculosis. The purpose of this project is to stop the interaction between the KshA and KshB complexes to prevent the bacteria from gaining energy by breaking down steroids like cholesterol. To achieve this goal, an arginine at the 286th position of the KshB protein was mutated to …

Methods For Analytical And Biophysical Analysis For Investigation Of Stimulator Of Interferon Genes In Drug Discovery, William Emmett Brian Lawless

USF Tampa Graduate Theses and Dissertations

This work elaborates on analytical and biophysical techniques including high pressure liquid chromatography (HPLC), mass spectrometry quadrupole time-of-flight (MS-QToF), dynamic light scattering (DLS), microscale thermophoresis (MST), surface plasmon resonance (SPR), isothermal calorimetry (ITC), size exclusion chromatography, and native gel electrophoresis. A basic overview is described for each technique and is designed for easy understanding by both novice and experienced analysts. Best practices for each technique are discussed and suggestions are made for protocol improvements or troubleshooting. Protocol development is discussed, and a method is introduced for MST that can be adapted to any target protein for rapid screening of analog …

New Methods For Stereoselective Glycosylation In Application To Significant Biomedical Targets, Melanie L. Shadrick

Dissertations

Glycosyl halides have been utilized for glycosylation reactions since the early studies by Arthur Michael, nearing the end of the 19^th century. Koenigs and Knorr then utilized silver salts to activate glycosyl bromides and chlorides to create synthetic glycosides. Many efforts to improve the outcome of reactions with glycosyl halides have emerged. The key emphasis has traditionally been placed on reaction rates, product yields, and stereocontrol. Recently, our lab reported that silver(I) oxide-mediated Koenigs-Knorr glycosylation reaction can be dramatically accelerated in the presence of catalytic acid additives. Methods to improve glycosylation was explored using mannosyl and glucosyl bromides. However, …

Investigating The Diffusion Of Solid Yttria Into Solid Zirconia For The Formation Of Yttria Stabilized Zirconia, Logan Thomas Ockershausen

Seton Hall University Dissertations and Theses (ETDs)

A molecular dynamics simulation of yttria-stabilized zirconia (YSZ) is reported in order to analyze the diffusion of the oxygen atoms from the yttria into the zirconia from an initial structure containing a layer of yttria on zirconia. The simulation was performed starting from a pure zirconia slab which was amorphized at the surface followed by placing a slab of yttria on top and a vacuum layer above that. The yttria/zirconia system was simulated at increasing temperatures to 1500K under canonical (NVT) constraints for 6.98 ns until the yttrium atom diffusion was found to occur. The final run was analyzed for …

Sigma Hole Potentials As Tools: Quantifying And Partitioning Substituent Effects, Kelling J. Donald, Nam Pham, Pranav Ravichandran

Chemistry Faculty Publications

Empirical substituent constants such as the Hammett parameters have found important utility in organic and other areas of chemistry. They are useful both in predicting the impact of substitutions on chemical processes and in rationalizing, after the fact, observations on chemical bonding and reactivity. We assess the impact of substitutions on mono-iodinated benzene rings and find that the modifications that substituents induce on the electrostatic potentials at the sigma hole on the terminal I center correlate strongly with established trends of common substituents. As an alternative to the experimental procedures involved in obtaining empirically based substituent constants, the computationally determined …

Cognitive Engagement During Group Learning Activities In Chemistry Courses: An Analysis Of Student Discourse, Safaa Youssef El-Mansy

Dissertations and Theses

As educators, our goal is to help our students be successful, but in order to accomplish this, we need to understand what factors contribute to student success. One factor, small-group active learning, has been correlated to improved academic outcomes; however, the magnitude of this improvement can vary across different courses, different types of group work, and even across courses that use the same group work structure. Therefore, it is important to understand what aspects of group work contribute to its effectiveness. The work presented in this dissertation investigated one specific aspect: students’ cognitive engagement. This was done by analyzing the …

Exclusive Regioselective Synthesis Of Potentially Bioactive 1,3,4-Selenadiazole, Mohamed Ali Mahmoud

Thesis/ Dissertation Defenses

Isoselenocyanates have a crucial role as reactants in chemical processes, facilitating the efficient synthesis of significant chemical intermediates and physiologically active chemicals. The utilization of (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides in a one-step procedure for the synthesis of the core structure of various heterocyclic compounds has been widely explored. This study focuses on the synthesis of 5-arylimino-1,3,4-selenadiazole derivatives through the reaction of isoselenocyanates with various substituted (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides. The objective is to achieve selective and accurate formation of these derivatives. The derivatives exhibit a diverse range of functional groups on both aryl rings. The synthetic procedure is conducted under ambient conditions, promoting environmental …

Impacts Of Hydrophobic Mismatch On Antimicrobial Peptide Efficacy And Bilayer Permeabilization., Steven Meier, Zachary M Ridgway, Angela L Picciano, Gregory A. Caputo

College of Science & Mathematics Departmental Research

Antimicrobial resistance continues to be a major threat to world health, with the continued emergence of resistant bacterial strains. Antimicrobial peptides have emerged as an attractive option for the development of novel antimicrobial compounds in part due to their ubiquity in nature and the general lack of resistance development to this class of molecules. In this work, we analyzed the antimicrobial peptide C18G and several truncated forms for efficacy and the underlying mechanistic effects of the sequence truncation. The peptides were screened for antimicrobial efficacy against several standard laboratory strains, and further analyzed using fluorescence spectroscopy to evaluate binding to …

Binding Interactions Of Biologically Relevant Molecules Studied Using Surface-Modified And Nanostructured Surfaces, Palak Sondhi

Dissertations

This research focuses on the field of surface nanobioscience, wherein different nanosurfaces that will be used as working electrodes in the electrochemical cell are manufactured and surface modified to understand the critical binding interactions between biologically significant molecules like proteins, carbohydrates, small drug molecules, and glycoproteins. This research is essential if we are to determine whether a synthetic molecule can serve as a therapeutic candidate or diagnose a disease in its early stages. In order to fully understand the binding interactions, the study begins with defining some of the fundamental concepts, principles, and analytical tools for biosensing.

Afterwards, we addressed …

Functional Aggregation Of Cell-Free Proteins Enables Fungal Ice Nucleation, Ralph Schwidetzky, Ingrid De Almeida Ribeiro, Nadine Bothen, Anna T. Backes, Arthur L. Devries, Mischa Bonn, Janine Fröhlich-Nowoisky, Valeria Molinero, Konrad Meister

Chemistry and Biochemistry Faculty Publications and Presentations

Biological ice nucleation plays a key role in the survival of cold-adapted organisms. Several species of bacteria, fungi, and insects produce ice nucleators (INs) that enable ice formation at temperatures above −10 °C. Bacteria and fungi produce particularly potent INs that can promote water crystallization above −5 °C. Bacterial INs consist of extended protein units that aggregate to achieve superior functionality. Despite decades of research, the nature and identity of fungal INs remain elusive. Here, we combine ice nucleation measurements, physicochemical characterization, numerical modeling, and nucleation theory to shed light on the size and nature of the INs from the …

Evaluation Of Iron Element By New Cpe Method And (Icp-Ms) In The Wastewater Of The Lifting And Treatment Stations, Mohammed Nasser Hussain, Ahmed Fadhil Khudhair, Hussain Jawad Ahmed

Al-Bahir

A new micell-mediated phase separation technique has been created to preconcentrate levels of iron before measuring it using a UV-Vis spectrophotometer. The method is based on the extraction of iron from the 1-Nitroso-2- naphthol reagent using Triton X-114 in a cloud point extraction procedure, where the method's ideal conditions were attained. 0.2 mL of Triton X-114, 2.887 mmol. L-1 of 1-Nitroso-2-naphthol reagent, pH = 8, 60 ºC. The Iron detection limit for the method is 0.05 µg. mL-1, and the RSD% is 4.728 µg. mL-1. Linearity was maintained in the iron concentration range of 0.25 to 16 µg. mL-1. Furthermore, …

Development Of Antibacterial Neural Stimulation Electrodes Via Hierarchical Surface Restructuring And Atomic Layer Deposition., Henna Khosla, Wesley Seche, Daniel Ammerman, Sahar Elyahoodayan, Gregory A. Caputo, Jeffrey Hettinger, Shahram Amini, Gang Feng

College of Science & Mathematics Departmental Research

Miniaturization and electrochemical performance enhancement of electrodes and microelectrode arrays in emerging long-term implantable neural stimulation devices improves specificity, functionality, and performance of these devices. However, surgical site and post-implantation infections are amongst the most devastating complications after surgical procedures and implantations. Additionally, with the increased use of antibiotics, the threat of antibiotic resistance is significant and is increasingly being recognized as a global problem. Therefore, the need for alternative strategies to eliminate post-implantation infections and reduce antibiotic use has led to the development of medical devices with antibacterial properties. In this work, we report on the development of electrochemically …

Inhibition Of Chromium(Iii) Oxidation Through Manganese(Iv) Oxide Passivation And Iron(Ii) Abiotic Reduction, Miranda L. Aiken, Macon J. Abernathy, Michael V. Schaefer, Ilkeun Lee, Samantha C. Ying

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Manganese (Mn) oxides are strong oxidants that are ubiquitous in soils and can oxidize redox-active metals, including chromium (Cr). In soil environments, trivalent chromium (Cr(III)) is a benign, immobile micronutrient, whereas the hexavalent Cr(VI) form is present as a highly mobile, toxic chromate oxyanion. Although many studies have characterized the capacity of Mn(III/IV) oxides to oxidize Cr(III) to toxic Cr(VI), the oxidative capacity of Mn oxides in the presence of potentially passivating soil constituents, specifically reduced soluble iron (Fe(II)aq), remains unresolved. We hypothesized that chemical processes at redox interfaces, such as diffusion-limited environments within soil aggregates, can lead to decreased …

Bioelectrocatalytic Synthesis: Concepts And Applications, Dylan G. Boucher, Emily Carroll, Zachary A. Nguyen, Rohit G. Jadhav, Olja Simoska, Kevin Beaver, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Bio electrocatalytic synthesis is the conversion of electrical energy into value-added products using biocatalysts. These methods merge the specificity and selectivity of biocatalysis and energy-related electrocatalysis to address challenges in the sustainable synthesis of pharmaceuticals, commodity chemicals, fuels, feedstocks and fertilizers. However, the specialized experimental setups and domain knowledge for bio electrocatalysis pose a significant barrier to adoption. This review introduces key concepts of bioelectrosynthetic systems. We provide a tutorial on the methods of biocatalyst utilization, the setup of bioelectrosynthetic cells, and the analytical methods for assessing bio electrocatalysts. Key applications of bio electrosynthesis in ammonia production and small-molecule synthesis …

Youth In Danger And Students At Risk Of Dropping Out, Mamoona Muzammil, Muzammil Arshad

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Bullying is any unwanted aggressive behavior(s) by another youth or group of youth that involves an observed or perceived power imbalance and is repeated multiple times or is highly likely to be repeated. Bullying may inflict harm or distress on the targeted youth including physical, psychological, social, or educational harm. Bullying can lead to fear of school, absenteeism, and stunted academic progress, which in turn are precursors to dropping out of school.

• Effects of Bullying on Students Long lasting effects
• School Dropout.
• Lack of Concentration
• Reduced Motivation
• Less Class Participation
• Less Attendance Lower Academic Achievement

Student Dropouts

The increase in …

Cost Analysis Of Adsorption Based Air Capture Of Co2, Mona Muzammil, Muzammil Arshad, Muazzam Arshad

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Carbon dioxide (CO2) capture and conversion to value added products, such as chemicals, polymers, and carbon-based fuels represents a promising approach to transform a potential threat to the environment into a value-added product for long term sustainability. Emerging Carbon Capture Technologies: Towards a Sustainable Future provides a multidisciplinary view of the research that is being carried out in this field, covering materials and processes for CO2 capture and utilization and including a broad discussion of the impact of novel technologies in carbon capture on the energy landscape, society and climate. Of interest to students, researchers and professionals in industries related …

Electrochemical Degradation Of Methylene Blue With Seawater And Pb/Pbo2 Electrodes From Battery Waste, Gunawan Gunawan, N. B. Adiwibawa Prasetya, Didik Setiyo Widodo, Roni Adi Wijaya

Karbala International Journal of Modern Science

Electrochemical degradation of methylene blue (MB) dye with seawater electrolyte using lead and lead oxide (Pb/PbO2) electrodes from waste batteries has been successfully conducted. Characterization of battery waste, the effectiveness of dye degradation, sodium hypochlorite (NaOCl) concentration, dissolved oxygen (DO) level, reaction mechanism, the effect of time variation (15, 30, 45, and 60 minutes), and voltage variation (0, 1, 2, 3, 4, and 5 volts) were observed. Characterization showed results by the characteristics of Pb and PbO2 confirmed by X-ray diffractometer (XRD) result-ing in 2θ peaks of Pb at 31.36, 36.38, 52.26, 62.36, 65.38º and 2θ (β-PbO2) at 25.4, 32.0, …

Biochemical Characterization Of A Fructosyltransferase Enzyme From A Halophilic Archaeon, Haloarcula Marismotui, For Biotechnological Applications, Ahlam Khalifa Al Ameri

Thesis/ Dissertation Defenses

Fructosyltransferase enzymes are involved in the production of fructans, which are polymers of fructose and naturally present in many foods like fruits, vegetables, legumes, and cereals. Fructans with short chain lengths are called Fructooligosaccharides (FOS), which are small dietary fibers having low caloric values and are known as “prebiotics”. Fructans have a broad range of applications in the food, pharmaceutical, cosmetics, and chemical industries. They have unique physicochemical properties and functionalities depending on the source of enzyme used for their production. The present study aimed at the utilization of a recently discovered unique fructosyltransferase enzyme from an extremely halophilic microorganism, …