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2025

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Full-Text Articles in Chemistry

Facile Synthesis Of Tetraaryl Phosphonium Ionic Liquids, Stephanie C. Jones, Devin J. Schwaibold, Grant Meadows, Brennan Shuler, Richard E. Sykora, Frank Rolf Fronczék, James H. Davis, Benjamin Wicker Mar 2025

Facile Synthesis Of Tetraaryl Phosphonium Ionic Liquids, Stephanie C. Jones, Devin J. Schwaibold, Grant Meadows, Brennan Shuler, Richard E. Sykora, Frank Rolf Fronczék, James H. Davis, Benjamin Wicker

EKU Faculty and Staff Scholarship

The syntheses of triphenyl-2-pyridylphosphonium salts, [Mopyphos]A, where A-= BF4-, B(C6H5)4-, (CF3SO2)2N-, Sac-, and Ace-. (Sac-= saccharinate, Ace-= acesulfamate) are described. These salts can be synthesized on a multi-gram scale with good yields and have been characterized by NMR, single crystal XRD, and HRMS. Thermal analyses indicate that the bistriflimide (Tf2N-= (CF3SO2)2N-) salts are especially amenable towards high-temperature ionic liquid (IL) applications with decomposition temperatures above 450 degrees C. The synthetic methods described herein can be utilized to generate several phosphonium bistriflimide ILs of the general formula [(C6H5)3P-Ar]Tf2N, where Ar = N-heteroaryl).


Development, Optimization, And Validation Of A High-Sensitivity Capillary Zone Electrophoresis System For Bioanalytical Applications, Aaron I. Mena Mar 2025

Development, Optimization, And Validation Of A High-Sensitivity Capillary Zone Electrophoresis System For Bioanalytical Applications, Aaron I. Mena

Electronic Theses and Dissertations

Capillary zone electrophoresis (CZE) is a powerful analytical technique widely used for biomolecular separation due to its high resolution, efficiency, and sensitivity. This report presents the development and validation of a novel CZE system designed to improve modularity, reproducibility, and operational efficiency. The system integrates a laser-induced fluorescence (LIF) detection method with a 488 nm laser, enhanced fluid control through a negative pressure system, and a user-friendly GUI for automated operation and data acquisition. Performance verification included pressure stability tests, fluorescence accuracy assessments, and electrophoretic reproducibility studies. Comparative analysis with a previous CZE iteration confirmed improved baseline stability, peak resolution, …


Synthetic Protein Mimetic Based Therapies For Neurodegeneration, Nicholas H. Stillman Mar 2025

Synthetic Protein Mimetic Based Therapies For Neurodegeneration, Nicholas H. Stillman

Electronic Theses and Dissertations

Protein-protein interactions (PPIs) are crucial for the regulation of a majority of, if not every fundamental cellular process. Despite their role in regular biological processes, dysregulated and/or aberrant protein-protein interactions (aPPIs) are often related to the onset of disease including cancer, viral infection, and amyloid diseases. aPPIs have historically been deemed ‘undruggable’ due to their large surface area and lack of a binding cavity; however, today, more than 40 disease-related aPPIs have been targeted with small molecules and several of those have reached clinical trials.

A class of synthetic protein mimetics called oligopyridylamides (OPs) has been shown to inhibit disease-related …


An Alternative To Biliverdin, Mesobiliverdin Ixα And Mesobiliverdin-Enriched Microalgae: A Review On The Production And Applications Of Mesobiliverdin-Related Products, Naveena Poudyal, Jon Y. Takemoto, Yuan-Yu Lin, Cheng-Wei T. Chang Mar 2025

An Alternative To Biliverdin, Mesobiliverdin Ixα And Mesobiliverdin-Enriched Microalgae: A Review On The Production And Applications Of Mesobiliverdin-Related Products, Naveena Poudyal, Jon Y. Takemoto, Yuan-Yu Lin, Cheng-Wei T. Chang

Chemistry and Biochemistry Student Research

Despite attracting interest for decades due to its anti-inflammatory and antioxidant capabilities, the use of biliverdin IXα (BV) in medicine and agriculture is hampered by uncertain purity and limited availability. A significant amount of effort has been devoted to the production and application of BV, but with limited success. Mesobiliverdin IXα (MBV), a natural BV analog derived from microalgae, offers a path to overcome the limitations of BV. MBV production is scalable, and it can be obtained at high purity. MBV and BV share important structural features (e.g., bridging propionate groups) and both are substrates of biliverdin reductase A (BVRA), …


Phase Separation Clustering Of Poly Ubiquitin Cargos On Ternary Mixture Lipid Membranes By Synthetically Cross-Linked Ubiquitin Binder Peptides, Soojung Kim, Kamsy K. Okafor, Rina Tabuchi, Cedric Briones, Il Hyung Lee Mar 2025

Phase Separation Clustering Of Poly Ubiquitin Cargos On Ternary Mixture Lipid Membranes By Synthetically Cross-Linked Ubiquitin Binder Peptides, Soojung Kim, Kamsy K. Okafor, Rina Tabuchi, Cedric Briones, Il Hyung Lee

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Ubiquitylation is involved in various physiological processes, such as signaling and vesicle trafficking, whereas ubiquitin (UB) is considered an important clinical target. The polymeric addition of UB enables cargo molecules to be recognized specifically by multivalent binding interactions with UB-binding proteins, which results in various downstream processes. Recently, protein condensate formation by ubiquitylated proteins has been reported in many independent UB processes, suggesting its potential role in governing the spatial organization of ubiquitylated cargo proteins. We created modular polymeric UB binding motifs and polymeric UB cargos by synthetic bioconjugation and protein purification. Giant unilamellar vesicles with lipid raft composition were …


Development Of S(Vi) And S(Iv) Chemistry: From Asymmetric Synthesis To Covalent Reactive Groups, Chuan Shan Mar 2025

Development Of S(Vi) And S(Iv) Chemistry: From Asymmetric Synthesis To Covalent Reactive Groups, Chuan Shan

USF Tampa Graduate Theses and Dissertations

This dissertation mainly covers the development of synthetic methodologies related to several heteroatom functional groups, including phosphonates P(V), sulfoximines S(VI), sulfonimidamides S(VI), sulfonimidoyl fluorides S(VI), and sulfinamides S(IV). The interests in these functionalities are not only out of chemistry curiosity but also due to their pharmaceutical importance indicated by the existing drug molecules that contain these functional groups. The first chapter introduced the importance of phosphonates in biochemistry and organic synthesis, also provided some essential background of our synthetic efforts. The second chapter described the phosphonate synthesis from commercially available starting materials, with the purpose to obtain heterocyclic phosphonates in …


Salmon As An Ecological Pathway Of Contaminants Into Alaskan Food Webs, Miranda Brohman, Gretchen Roffler, Dimitri G. Giarikos, David Kerstetter, Amy C. Hirons Mar 2025

Salmon As An Ecological Pathway Of Contaminants Into Alaskan Food Webs, Miranda Brohman, Gretchen Roffler, Dimitri G. Giarikos, David Kerstetter, Amy C. Hirons

SECLER Data

Salmon are important fish taxa for humans and animals in hemiboreal and subarctic ecosystems. Trace elements and their marine food web bioaccumulation raises biomagnification and potential human health risk concerns. Sixteen trace element concentrations and their health risk assessments were determined in seven different tissues of two Southeast Alaska salmon species (chum, Oncorhynchus keta and pink, Oncorhynchus gorbuscha). Chum tissues had overall higher trace element concentrations compared to pink, which may be attributed to a difference of diets, generally longer-lived and spending more time in the open ocean. All kidney and liver samples exceeded the tolerable daily intake for …


Efforts To Improve General Chemistry Student Success: Describing Stoichiometry Solution Patterns And Investigating Challenge Perceptions, Dianna Kim Mar 2025

Efforts To Improve General Chemistry Student Success: Describing Stoichiometry Solution Patterns And Investigating Challenge Perceptions, Dianna Kim

USF Tampa Graduate Theses and Dissertations

There is a need for capable STEM graduates to fill needed STEM career gaps, particularly for people who have been historically under-represented in the STEM field (e.g., women, people of color, people of lower economic status, etc.). A course that have great impact would be General Chemistry which typically acts as a pre-requisite for manty STEM majors and careers. The efforts to be described in this thesis was conducted at a large, public doctoral granting university in the southeastern United States of America. The first effort described in this thesis explores how students solve different types of stoichiometry-based problems along …


Redefining The Limits Of Functional Continuity In The Early Evolution Of P-Loop Ntpases, Andrey O. Demkiv, Saacnicteh Toledo-Patiño, Encarnación Medina-Carmona, Andrej Berg, Gaspar P. Pinto, Antonietta Parracino, Jose M. Sanchez-Ruiz, Alvan C. Hengge, Paola Laurino, Liam M. Longo, Shina Caroline Lynn Kamerlin Mar 2025

Redefining The Limits Of Functional Continuity In The Early Evolution Of P-Loop Ntpases, Andrey O. Demkiv, Saacnicteh Toledo-Patiño, Encarnación Medina-Carmona, Andrej Berg, Gaspar P. Pinto, Antonietta Parracino, Jose M. Sanchez-Ruiz, Alvan C. Hengge, Paola Laurino, Liam M. Longo, Shina Caroline Lynn Kamerlin

Chemistry and Biochemistry Faculty Publications

At the heart of many nucleoside triphosphatases is a conserved phosphate-binding sequence motif. A current model of early enzyme evolution proposes that this six to eight residue motif could have sparked the emergence of the very first nucleoside triphosphatases—a striking example of evolutionary continuity from simple beginnings, if true. To test this provocative model, seven disembodied Walker A-derived peptides were extensively computationally characterized. Although dynamic flickers of nest-like conformations were observed, significant structural similarity between the situated peptide and its disembodied counterpart was not detected. Simulations suggest that phosphate binding is nonspecific, with a preference for GTP over orthophosphate. Control …


Synthesis Of A Series Of Rare-Earth-Based Multi-Anion Chalcogenide Iodides Re3Si2SeXS8-XI (Re = La, Ce, Pr, And Nd) Using The Flux-Assisted Boron-Chalcogen Mixture Method, Gopabandhu Panigrahi, Habiba Binte Kashem, Gregory Morrison, Hans Conrad Zur Loye Mar 2025

Synthesis Of A Series Of Rare-Earth-Based Multi-Anion Chalcogenide Iodides Re3Si2SeXS8-XI (Re = La, Ce, Pr, And Nd) Using The Flux-Assisted Boron-Chalcogen Mixture Method, Gopabandhu Panigrahi, Habiba Binte Kashem, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

Single crystals and polycrystalline powders of rare earth mixed chalcogenide iodides La3Si2Se1.21S6.79I, Ce3Si2Se1.39S6.61I, Pr3Si2Se1.22S6.78I, and Nd3Si2Se1.18S6.82I were prepared using the reactive flux-assisted boron-chalcogen mixture (BCM) method at 850 °C. All compounds crystallized in the monoclinic crystal system, space group C2/c (space group number 15). The series adopts the La3Si2O8Cl structure type, containing isolated SiQ4 tetrahedra connected by REQ8 (RE = La, Ce, Pr and Nd) polyhedra; this arrangement creates tunnels that are filled by I atoms. The partial substitution of S by Se was carried out to modulate the optical properties. Phase pure samples and uniform solid solutions were obtained …


The Binding Of Cu2+ To Lipid Membranes Is Not Substantially Influenced By Electrostatic Screening, Christopher M. Reynolds, Olivia C. Fiebig, Alexa Marroquin, Andrew J. Glaid, Kushaal Chokhany, Ryan G. Zdenek, Maria Laura Da Cruz Garcia, Paul S. Cremer Mar 2025

The Binding Of Cu2+ To Lipid Membranes Is Not Substantially Influenced By Electrostatic Screening, Christopher M. Reynolds, Olivia C. Fiebig, Alexa Marroquin, Andrew J. Glaid, Kushaal Chokhany, Ryan G. Zdenek, Maria Laura Da Cruz Garcia, Paul S. Cremer

Chemistry: Faculty Publications

Gouy-Chapman theory predicts that salt screening and modulating the interfacial charge density should strongly influence the apparent dissociation constant, Kd,app, between Cu2+ and negatively charged phosphatidylserine (PS) lipids in supported lipid bilayers (SLBs). Specifically, Kd,app would be expected to increase (weaken binding) by a factor of 40 when 100 mM NaCl is introduced into the solution because of electrostatic screening between the membrane and Cu2+ cations. Surprisingly, however, fluorescence quenching measurements demonstrate that Kd,app increases by less than a factor of 2 when increasing the salt concentration in the presence of standard buffers, such as tris(hydroxymethyl)aminomethane (Tris). Moreover, …


A Comparison Of Unconventional Microwave And Ultrasound-Assisted Extraction Methods Used For Flavonoids, Istiqomah Rahmawati, Daffa Hafiziaulhaq Azizi, Jihan Nafila Wibowo, Muhammad Reza, Boy Arief Fachri, Bekti Palupi, Meta Fitri Rizkiana, Helda Wika Amini, Ifan Ramadana, Felix Arie Setiawan Mar 2025

A Comparison Of Unconventional Microwave And Ultrasound-Assisted Extraction Methods Used For Flavonoids, Istiqomah Rahmawati, Daffa Hafiziaulhaq Azizi, Jihan Nafila Wibowo, Muhammad Reza, Boy Arief Fachri, Bekti Palupi, Meta Fitri Rizkiana, Helda Wika Amini, Ifan Ramadana, Felix Arie Setiawan

Makara Journal of Science

Cocoa pods (Theobroma cacao L.) are a rich source of flavonoids, which are natural antioxidants known for their health benefits. This study investigated the use of microwave-assisted extraction (MAE) and ultrasound-assisted ex-traction (UAE) to extract the maximum flavonoids and antioxidants from cocoa pods. MAE and UAE are efficient and sustainable methods for extracting bioactive compounds like flavonoids and antioxidants from cocoa pods, offer-ing faster extraction, reduced solvent use, and better compound preservation compared to conventional methods. These technologies unlock the untapped potential of cocoa pods for applications in food, cosmetics, and pharmaceuti-cals. The effects of extraction time (2–10 min), microwave …


Overexpression And Biophysical And Functional Characterization Of A Recombinant Fgf21, Phuc Phan, Jason Hoang, Thallapuranam Krishnaswamy Suresh Kumar Mar 2025

Overexpression And Biophysical And Functional Characterization Of A Recombinant Fgf21, Phuc Phan, Jason Hoang, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast growth factor 21 (FGF21) is an endocrine FGF that plays a vital role in regulating essential metabolic pathways. FGF21 increases glucose uptake by cells, promotes fatty acid oxidation, reduces blood glucose levels, and alleviates metabolic diseases. However, detailed studies on its stability and biophysical characteristics have not been reported. Herein, we present the overexpression, biophysical characterization, and metabolic activity of a soluble recombinant FGF21 (rFGF21). The far-UV circular dichroism spectra of rFGF21 show a negative trough at 215 nm, indicating that the protein's backbone predominantly adopts a 13 sheet conformation. rFGF21 shows intrinsic tyrosine fluorescence at 305 nm. Thermal …


Energy-Aware Clustering Using Intelligent Scheme For Heterogeneous Wireless Sensor Networks, Enaam A. Al-Hussain, Ghaida A. Al-Suhail Mar 2025

Energy-Aware Clustering Using Intelligent Scheme For Heterogeneous Wireless Sensor Networks, Enaam A. Al-Hussain, Ghaida A. Al-Suhail

Karbala International Journal of Modern Science

Heterogeneous Wireless Sensor Networks (WSNs) involve nodes with varying capabilities, such as different energy levels, sensing ranges, and computational abilities, which enable them to execute different tasks professionally. Clustering techniques play a crucial role in improving energy efficiency and reliability in WSNs. The evolution of cluster based WSNs from homogeneous into heterogeneous techniques allowed the deployment of smart devices capable of performing complex operations in in diverse environments. However, the heterogeneity of nodes necessitates more sophisticated and adaptive algorithms to fully exploit these capabilities. This paper proposes a new protocol, referred to as IT2F-HLEACH, which integrates Interval Type-2 Fuzzy Logic …


Comprehensive Review On The Application Of Bio-Immunoinformatics In The Development Of Highly Ef-Fective New Candidate Vaccines Against Tuberculosis, Ahyar Ahmad, Andriansjah Rukmana, Miski A. Khairinisa, Dian A. E. Pitaloka, Rosana Agus, Rusdina B. Ladju, Tarwadi Ahmad, Astutiati Nurhasanah, Carina C. D. Joe, Muhammad N. Massi, Harningsih Karim, Irda Handayani, Siti Roszilawati Binti Ramli Mar 2025

Comprehensive Review On The Application Of Bio-Immunoinformatics In The Development Of Highly Ef-Fective New Candidate Vaccines Against Tuberculosis, Ahyar Ahmad, Andriansjah Rukmana, Miski A. Khairinisa, Dian A. E. Pitaloka, Rosana Agus, Rusdina B. Ladju, Tarwadi Ahmad, Astutiati Nurhasanah, Carina C. D. Joe, Muhammad N. Massi, Harningsih Karim, Irda Handayani, Siti Roszilawati Binti Ramli

Karbala International Journal of Modern Science

Tuberculosis (TB) remains a significant public health challenge worldwide. Currently, Bacillus Calmette-Guerin (BCG) is the only vaccine available for TB prophylaxis. However, the efficacy of the BCG vaccine against adult pulmonary TB is considered inconsistent. This condition encourages researchers to look for more effective options, such as subunit vaccines. This condition requires the development of a more effective subunit vaccine to protect active TB in productive and adult ages. There is an urgent need for more effective vaccines, as the Bacillus Calmette-Guérin (BCG) vaccine currently available has inconsistent efficacy and is only partially effective in adults. Bio-immunoinformatics, an interdisciplinary field …


Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah Mar 2025

Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah

Makara Journal of Science

Thin films of zinc oxide (ZnO) and niobium (Nb)-doped ZnO were deposited on a glass substrate using the sol–gel spin coating method. Diethanolamine, isopropyl alcohol, and zinc acetate served as the stabilizers, solvent, and starting ma-terial, respectively. Niobium pentachloride was employed as the dopant source. Energy-dispersive X-ray analysis con-firmed Nb incorporation. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultravio-let–visible spectroscopy (UV–Vis) analyses characterized the morphology, structure, and optics of the films, respective-ly. Both films, comprising nanoparticles, were visible in FESEM. Nb doping reduced the particle size from 44.2 nm to 35.8 nm. The XRD peaks at 31.23°, …


Biochemical, Structural, And Conformational Characterization Of A Fungal Ethylene-Forming Enzyme, Shramana Chatterjee, Joel A. Rankin, Mark A. Farrugia, Simahudeen Bathir J S Rifayee, Christo Z. Christov, Jian Hu, Et. Al. Mar 2025

Biochemical, Structural, And Conformational Characterization Of A Fungal Ethylene-Forming Enzyme, Shramana Chatterjee, Joel A. Rankin, Mark A. Farrugia, Simahudeen Bathir J S Rifayee, Christo Z. Christov, Jian Hu, Et. Al.

Michigan Tech Publications

The ethylene-forming enzyme (EFE) from the fungus Penicillium digitatum strain Pd1 was heterologously produced in Escherichia coli and its properties were compared to the extensively characterized bacterial enzyme from Pseudomonas savastanoi strain PK2. Both enzymes catalyze four reactions: the conversion of 2-oxoglutarate (2OG) to ethylene and CO2, oxidative decarboxylation of 2OG coupled to L-arginine (L-Arg) hydroxylation, uncoupled oxidative decarboxylation of 2OG, and the production of 3-hydroxypropionate (3-HP) from 2OG. The strain Pd1 enzyme exhibited a greater ratio of ethylene production over L-Arg hydroxylation than the PK2 strain EFE. The uncoupled decarboxylation of 2OG and …


Visible-Light-Driven Catalytic Dehalogenation Of Trichloroacetic Acid And Α-Halocarbonyl Compounds: Multiple Roles Of Copper, Abigail J. Thillman, Erin C. Kill, Alexander N. Erickson, Dian Wang Mar 2025

Visible-Light-Driven Catalytic Dehalogenation Of Trichloroacetic Acid And Α-Halocarbonyl Compounds: Multiple Roles Of Copper, Abigail J. Thillman, Erin C. Kill, Alexander N. Erickson, Dian Wang

Chemistry Faculty Research and Publications

Herein, we report the reaction development and mechanistic studies of visible-light-driven Cu-catalyzed dechlorination of trichloroacetic acid for the highly selective formation of monochloroacetic acid. Visible-light-driven transition metal catalysis via an inner-sphere pathway features the dual roles of transition metal species in photoexcitation and substrate activation steps, and a detailed mechanistic understanding of their roles is crucial for the further development of light-driven catalysis. This catalytic method, which features environmentally desired ascorbic acid as the hydrogen atom source and water/ethanol as the solvent, can be further applied to the dehalogenation of a variety of halocarboxylic acids and amides. Spectroscopic, X-ray crystallographic, …


Infrared Laser Ablation Of Biomolecules From Formalin-Fixed Tissue, Blessing Chisom Egbejiogu Mar 2025

Infrared Laser Ablation Of Biomolecules From Formalin-Fixed Tissue, Blessing Chisom Egbejiogu

LSU Doctoral Dissertations

In the research described in this dissertation, a high-precision infrared laser ablation microsampling method was utilized for spatially resolved proteomic and lipidomic analyses of formalin fixed paraffin embedded (FFPE) tissue, a widely used archival sample in biomedical research. Despite its extensive use, FFPE tissue presents challenges for proteomic analysis due to protein cross-linking and modifications introduced during fixation, which can hinder extraction and identification. Developing a streamlined high-resolution method to recover biomolecules from FFPE samples is critical for advancing biomarker discovery, retrospective studies, and multi-omics research. To address these challenges, this study employs an infrared (IR) laser ablation microdissection system …


A Bland–Altman Comparison Of The Lead Care® System And Inductively Coupled Plasma Mass Spectrometry For Detecting Low-Level Lead In Child Whole Blood Samples, Christina Sobin, Tanner Schaub, Natali Parisi, Eva De La Riva Mar 2025

A Bland–Altman Comparison Of The Lead Care® System And Inductively Coupled Plasma Mass Spectrometry For Detecting Low-Level Lead In Child Whole Blood Samples, Christina Sobin, Tanner Schaub, Natali Parisi, Eva De La Riva

Departmental Papers (PH)

Chronic childhood lead exposure, yielding blood lead levels consistently below 10 μg/dL, remains a major public health concern. Low neurotoxic effect thresholds have not yet been established. Progress requires accurate, efficient, and cost-effective methods for testing large numbers of children. The LeadCare® System (LCS) may provide one ready option. The comparability of this system to the “gold standard” method of inductively coupled plasma mass spectrometry (ICP-MS) for the purpose of detecting blood lead levels below 10 μg/dL has not yet been examined. Paired blood samples from 177 children ages 5.2–12.8 years were tested with LCS and ICP-MS. Triplicate repeat tests …


Raw Data For Violations Of Coordination: Exploring Metastable Diborides For Energy Storage, Michael Yeung Mar 2025

Raw Data For Violations Of Coordination: Exploring Metastable Diborides For Energy Storage, Michael Yeung

Chemistry Department Faculty Scholarship

The ideal aeronautical solid-state fuel should possess a high density (more thrust per Newton’s Third Law), high gravimetric heat of combustion (more energy for less weight), and a high volumetric heat of combustion (more room for mission-critical items). In this work, manganese diboride (MnB2) demonstrates a high density of 5.3 g/cm3, a high gravimetric heat of combustion of 38.30 kJ/g, and the highest volumetric heat of combustion of any known fuel of 202.99 kJ /cm3. When compared to the currently used fuel in Space Shuttle rocket boosters and the Space Launch System, aluminum metal, MnB2 represents a 100% increase in …


Nanostructure Retention To 1100 °C In Soft-Templated Niobium Tungstates Using Dual-Carbon Strategy, Sean C. Wechsler, Alexander Gregg, Coby S. Collins, Santosh Kiran Balijepalli, Morgan Stefik Mar 2025

Nanostructure Retention To 1100 °C In Soft-Templated Niobium Tungstates Using Dual-Carbon Strategy, Sean C. Wechsler, Alexander Gregg, Coby S. Collins, Santosh Kiran Balijepalli, Morgan Stefik

Faculty Publications

Mesoporous metal oxides (MMOs) have diverse applications including energy storage, catalysis, and separation membranes. Block polymer structure directing agents enable the control of morphology and pore size, however preservation of the nanostructure is often limited to a narrow range of heat treatment temperatures which constrains the tailoring of defect chemistries. High temperature treatments typically lead to collapse of the porous structure as surface area is reduced during crystal growth. Here, using a mesoporous niobium tungstate it is shown that neither in situ carbon generation nor ex situ carbon infiltration alone enable preservation of the ordered mesostructure at temperatures high enough …


The Role Of Homocysteine Redox Chemistry In Biomolecular Mechanisms, Megha Gupta Mar 2025

The Role Of Homocysteine Redox Chemistry In Biomolecular Mechanisms, Megha Gupta

Dissertations and Theses

Homocysteine at elevated levels is a well-known independent risk factor for cardiovascular disease. However, it is still unclear, after large scale clinical trials, involving tens of thousands of patients, whether homocysteine is a disease mediator or marker. The disconnect between the basic science showing the association of homocysteine with cardiovascular disease and the outcomes of clinical trials based on vitamin therapy for homocysteine lowering, highlights the need for insights into the molecular mechanisms linking homocysteine to cardiovascular disease and other pathologies. For example, elevated homocysteine levels have also been associated with risk for stroke, venous thromboembolism, Alzheimer's disease, neural tube …


Solid-State Crystallization Of Zeolites And Their Use In Plastic Upcycling Applications, Yixin Liao Mar 2025

Solid-State Crystallization Of Zeolites And Their Use In Plastic Upcycling Applications, Yixin Liao

Doctoral Dissertations

Plastics have been an irreplaceable component of modern technology as well as everyday life. They have brought much convenience to us with their characteristics of great malleability, durability, and stability. The versatile and low-cost nature of plastics also enables their wide engagement in many modern industries including automobile, medical, communication as well as aerospace. Polyethylene (“PE”), made from polymerization of ethylene, is one of the most widely used plastics in the world. Being cheap, flexible, and long-lasting, they are extensively used in the packaging industry, especially for plastic bags and other sorts of containers. However, the durability of plastics, on …


Photo-Enhanced Output In Memdiode Devices Based On Hybrid Materials Open Access, Jacob Lee, Prabir Patra, Judy Fan Mar 2025

Photo-Enhanced Output In Memdiode Devices Based On Hybrid Materials Open Access, Jacob Lee, Prabir Patra, Judy Fan

Physics Faculty Research

The discovery of photo-enhanced outputs in the fabricated memdiodes based on metal halide-embedded polymeric hybrid composites has meaningful and practical implications. The two-terminal devices exhibit typical rectifying characteristics, similar to a standard pn junction diode, with unusual photo-enhanced charge transportation and hysteresis behaviors. The MDs consist of an active layer of blended organic–inorganic hybrid material [a mixture of CuCl2 and polyethylene glycol (PEG)] deposited on a layer of pure polymer (polymethyl methacrylate) and, in turn, on a rigid substrate (ITO glass or Si wafer). It is found that the photoinduced current increases hundreds of times in magnitude on the ITO …


Air-Based Chemical Patient Decontamination Methodologies For Arctic Regions Using Methly Salicylate As A Chemical Agent Surrogate On A Litter-Bound Manikin, Marcus D. Shadd Mar 2025

Air-Based Chemical Patient Decontamination Methodologies For Arctic Regions Using Methly Salicylate As A Chemical Agent Surrogate On A Litter-Bound Manikin, Marcus D. Shadd

Theses and Dissertations

This study evaluated a mobile air shower for patient decontamination without disrobing or rinsing, an alternative for Arctic conditions where water is scarce. A manikin in extreme cold weather gear was exposed to 10 µL of methyl salicylate (MeS), a sulfur mustard surrogate, and placed in a horizontal chamber on a military litter. Airborne MeS was measured using a ppbRAE 3000 detector to assess inhalation risk for the patient and decontamination team. Three methods were tested: an air-knife system, paper towels, and no decontamination, with 10 trials each (30 total). ANOVA analysis showed significant reductions in airborne MeS with air-knife …


Refining Chlorosulfonation Methods For The Synthesis Of A Perfluoroalkyl Arylsulfonimide (Pfsi) Monomer, Ainsley P. Foster, Ben Varney, Hua Mei Mar 2025

Refining Chlorosulfonation Methods For The Synthesis Of A Perfluoroalkyl Arylsulfonimide (Pfsi) Monomer, Ainsley P. Foster, Ben Varney, Hua Mei

SPARK Symposium Presentations

Proton-exchange membrane (PEM) fuel cells are sources of energy that are clean, quiet, and highly responsive to changes in power needs, making them promising for use in automobiles and other portable power devices. The electrolyte of a PEM cell–the layer responsible for conductivity–is a polymer membrane, commonly consisting of perfluoroalkyl sulfonic acid (PFSA) polymers. In place of the PFSA polymers, perfluoroalkyl arylsulfonimide (PFSI) polymers are expected to improve the efficiency of PEM fuel cells with better stability and proton conductivity. The trifluovinylether (TFVE) aryl perfluorosulfonamide monomer is a new PFSI monomer proposed to fulfill these benefits once polymerized. The previous …


Molecular Scale Investigations Of Interactions Between Pfas And Concrete, Eric E. Keeler Mar 2025

Molecular Scale Investigations Of Interactions Between Pfas And Concrete, Eric E. Keeler

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS), widely referred to as “forever chemicals,” exhibit high environmental persistence and potential health risks due to their robust carbon-fluorine bonds. These substances are prevalent in aqueous film-forming foams (AFFF), used in industrial and military applications, and are known to contaminate environmental surfaces, including concrete. This study aims to characterize the molecular-level interaction energies of six PFAS species—PFOA, PFOS, PFHxS, PFHxA, 6:2 FTS, and PFBS—with calcium silicate, a key component of concrete, using density functional theory (DFT) calculations. Change in Gibbs free energy (ΔG) was determined for each of the interactions, revealing negative ΔG values for …


Evaluating Dry Air Personnel Decontamination Of Methyl Salicylate As A Chemical Agent Surrogate In Extreme Cold Environments To Reduce Airborne Risks Using A Manikin, Lance E. Campbell Mar 2025

Evaluating Dry Air Personnel Decontamination Of Methyl Salicylate As A Chemical Agent Surrogate In Extreme Cold Environments To Reduce Airborne Risks Using A Manikin, Lance E. Campbell

Theses and Dissertations

This research investigated a mobile air shower as an alternative to water washing for personnel chemical decontamination in Arctic environments, where traditional methods like disrobing and rinsing are impractical. Interest in Arctic operations has grown with recent U.S. military focus on strategic advancements by Russia and China, yet research on air shower effectiveness for chemical decontamination remains limited. This study examined whether a commercial off-the-shelf air shower could effectively decontaminate methyl salicylate (MES), a surrogate for chemical warfare blister agents, from a manikin outfitted in military cold-weather gear. Researchers used a ppbRAE 3000 photo-ionization detector to measure MES concentrations following …


Atmospheric Water Generation: Bacterial And Inorganic Chemical Quality, Garrett E. Stanley Mar 2025

Atmospheric Water Generation: Bacterial And Inorganic Chemical Quality, Garrett E. Stanley

Theses and Dissertations

This study investigated the quality of untreated water collected from a vapor compression-based atmospheric water generator (AWG) operated outdoors in Dayton, Ohio. The concentrations of bacterial and chemical constituents were determined. The concentration of culturable bacteria was between 200 and 2300 CFU/mL, significantly higher than the reference levels described in recreational and drinking water quality guidance. Three discrete bacteria phenotypes were visually identified; two were yellow in color, rod-shaped and gram-negative while the third was milky white, circular, and gram-positive. Chemical analysis on 15 randomly selected samples revealed the presence of Barium (average = 0.16 mg/L), Magnesium (0.08 = mg/L), …