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Full-Text Articles in Physical Sciences and Mathematics

Transport And Plugging Performance Evaluation Of A Novel Re-Crosslinkable Microgel Used For Conformance Control In Mature Oilfields With Super-Permeable Channels, Adel Alotibi, T. Song, Baojun Bai, Thomas P. Schuman Jan 2023

Transport And Plugging Performance Evaluation Of A Novel Re-Crosslinkable Microgel Used For Conformance Control In Mature Oilfields With Super-Permeable Channels, Adel Alotibi, T. Song, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Preformed particle gels (PPG) have been widely applied in oilfields to control excessive water production. However, PPG has limited success in treating opening features because the particles can be flushed readily during post-water flooding. We have developed a novel micro-sized Re-crosslinkable PPG (micro-RPPG) to solve the problem. The microgel can re-crosslink to form a bulk gel, avoiding being washed out easily. This paper evaluates the novel microgels' transport and plugging performance through super-permeable channels. Micro-RPPG was synthesized and evaluated for this study. Its storage moduli after fully swelling are approximately 82 Pa. The microgel characterization, self-healing process, transportation behavior, and …

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Chemical Decomposition Of Flexible Polyurethane Foam To Generate A Media For Microbial Upcycling, Kaushik Baruah Jan 2023

Chemical Decomposition Of Flexible Polyurethane Foam To Generate A Media For Microbial Upcycling, Kaushik Baruah

Dissertations, Master's Theses and Master's Reports

Polyurethane waste is becoming a global concern as a large amount is being disposed of in landfills every year, and only a fraction is being recycled. Several polyurethane recycling techniques exist, of which ammonolysis and base-catalyzed hydrolysis is the least explored. Flexible polyurethane foam (FPUF) decomposition can generate amines that can act as a carbon source for the growth of microbial consortia. This study aims to generate a novel media capable of microbial upcycling via ammonolysis and base-catalyzed hydrolysis of flexible polyurethane foams (FPUFs) using ammonium hydroxide and subsequently determine the reaction conditions for maximum solubilization of polyurethane foam in …

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Molecular Dynamics Modeling Of Polymers For Aerospace Composites, Swapnil Sambhaji Bamane Jan 2023

Molecular Dynamics Modeling Of Polymers For Aerospace Composites, Swapnil Sambhaji Bamane

Dissertations, Master's Theses and Master's Reports

Polymer matrix composite materials are widely used as structural materials in aerospace and aeronautical vehicles. Resin/reinforcement wetting and the effect of polymerization on the thermo-mechanical properties of the resin are key parameters in the manufacturing of aerospace composite materials. Determining the contact angle between combinations of liquid resin and reinforcement surfaces is a common method for quantifying wettability. It is challenging to determine contact angle values experimentally of high-performance resins on CNT materials such as CNT, graphene, bundles or yarns, and BNNT surfaces. It is also experimentally difficult to determine the effect of polymerization reaction on material properties of a …

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Sound The (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide Pgpp, Areej Malik, Megan A. Hept, Erin B. Purcell Jan 2023

Sound The (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide Pgpp, Areej Malik, Megan A. Hept, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been …

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Synthesis Of A Series Of Trimeric Branched Glycoconjugates And Their Applications For Supramolecular Gels And Catalysis, Jonathan Bietsch, Anji Chen, Dan Wang, Guijun Wang Jan 2023

Synthesis Of A Series Of Trimeric Branched Glycoconjugates And Their Applications For Supramolecular Gels And Catalysis, Jonathan Bietsch, Anji Chen, Dan Wang, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-derived molecular gelators have found many practical applications as soft materials. To better understand the structure and molecular gelation relationship and further explore the applications of sugar-based gelators, we designed and synthesized eight trimeric branched sugar triazole derivatives and studied their self-assembling properties. These included glucose, glucosamine, galactose, and maltose derivatives. Interestingly, the gelation properties of these compounds exhibited correlations with the peripheral sugar structures. The maltose derivative did not form gels in the tested solvents, but all other compounds exhibited gelation properties in at least one of the solvents. Glucose derivatives showed superior performance, followed by glucosamine derivatives. They …

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Detection And Quantification Of Antiviral Drug Tenofovir Using Silver Nanoparticles And Surface Enhanced Raman Spectroscopy (Sers) With Spatially Resolved Hotspot Selection, Marguerite R. Butler, Jana Hrncirova, Terry A. Jacot, Sucharita Dutta, Meredith R. Clark, Gustavo F. Doncel, John B. Cooper Jan 2023

Detection And Quantification Of Antiviral Drug Tenofovir Using Silver Nanoparticles And Surface Enhanced Raman Spectroscopy (Sers) With Spatially Resolved Hotspot Selection, Marguerite R. Butler, Jana Hrncirova, Terry A. Jacot, Sucharita Dutta, Meredith R. Clark, Gustavo F. Doncel, John B. Cooper

Chemistry & Biochemistry Faculty Publications

This study introduces a convenient and ultra-sensitive method of detection and quantification of the antiviral drug, tenofovir (TFV), by surface-enhanced Raman spectroscopy (SERS). Novel spatially resolved instrumentation for spectral acquisition and subsequent statistical analysis for hot spot selection was developed for convenient quantification of TFV in an aqueous matrix. Methods of statistical analysis include the use of partial least squares (PLS) regression vector analysis and spectral ranking by quality indices computed using CHAOS theory. Hydroxylamine-reduced Ag colloidal nanoparticles evaporated to dryness on an aluminum well-plate were used as the SERS substrate. To our knowledge, quantification of TFV down to 25 …

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Modulatory Effects Of Deacetylated Sialic Acids (A Sugar Residue) In Nk-Mediated Cytotoxicity And Targeted Therapy By Receptor Tyrosine Kinase Inhibitors, Mathias Tawiah Anim Jan 2023

Modulatory Effects Of Deacetylated Sialic Acids (A Sugar Residue) In Nk-Mediated Cytotoxicity And Targeted Therapy By Receptor Tyrosine Kinase Inhibitors, Mathias Tawiah Anim

Electronic Theses and Dissertations

The complex nature of the biology of cancer is still an unraveling science, yielding several biomarkers that have served as molecular targets for detection and treatment of the disease. How sugars, glycans, play a role has remained relatively uninvestigated. Sialic acid (Sia), a sugar residue on the surface of cells, has been identified as a hallmark of cancer and its progression. Sialic acid can be highly functionalized, but we became interested in acetylated Sias. This functional group is modulated by Sialate O- acetylesterase (encoded by the gene SIAE) and Sialate O-acetyltransferase (encoded by CASD1), enzymes that play a crucial role …

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Development And Assessment Of Gamified Process-Oriented Guided Inquiry Learning Activities In Undergraduate Large Lecture Chemistry Courses, Nathan Turner Jan 2023

Development And Assessment Of Gamified Process-Oriented Guided Inquiry Learning Activities In Undergraduate Large Lecture Chemistry Courses, Nathan Turner

Electronic Theses and Dissertations

Students who take general chemistry and do not perform well are more likely to pursue an alternative degree or remove themselves from STEM curriculum entirely. Poor academic performance and high student attrition rates in general chemistry courses have resulted in the perception of chemistry courses being gatekeepers for students in pursuit of STEM degrees. Process-Oriented Guided Inquiry Learning (POGIL) has shown promising results in both lecture and laboratory teaching on student performance in chemistry while gamification has been used to enhance student learning experiences to help students grasp chemistry concepts. The current project blends two student-centered approaches, gamification and POGIL, …

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Autodocking Studies Of Oxygenated Fullerenes As Inhibitors Of The Hiv Protease, Michael Kaminski Jan 2023

Autodocking Studies Of Oxygenated Fullerenes As Inhibitors Of The Hiv Protease, Michael Kaminski

All Student Theses and Dissertations

In a previous study, several oxygenated fullerene compounds were produced by ozonation of C60 (Buckminsterfullerene) and were identified by elemental analysis and by SALI (surface analysis by laser ionization). Some of these compounds, especially a batch, SK-5, a mixture of C60O1-8, were shown to inhibit activities of HIV-Protease with IC50 (concentration for 50% inhibition) of 1 mg/mol in the in-vitro studies. The oxygenated fullerenes were shown to have epoxide, ketones, and hydroxyl functionalities. As expected, C60 interacted with ozone with alkene functionality and not as an aromatic compound. It was postulated that C60O had epoxide functionality, as a product of …

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Cultivating Health, Not Wealth In The United States' Healthcare System: Comprehensive Revisions For The Orphan Drug Act Of 1983, Kayla Smith Jan 2023

Cultivating Health, Not Wealth In The United States' Healthcare System: Comprehensive Revisions For The Orphan Drug Act Of 1983, Kayla Smith

Regis University Student Publications (comprehensive collection)

This thesis explores the way in which the Orphan Drug Act of 1983, originally instituted in response to a lack of treatments for rare diseases in the United States of America, has failed to achieve its initial objectives in the 40 years since its implementation. In evaluating various successful examples of government subsidization programs designed to intervene in private industry, this thesis composes the criterion required for funding-based legislation which maximize market outcomes while minimizing tax-payer burden. An analysis of the synthetic organic chemistry industry – and a case study into the production of a particular orphan treatment for a …

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Comprehensive Analysis And Forensic Investigation Of Cyanide, Thiocyanate, And 2-Amino-2-Thiazoline-4-Carboxylic Acid In-Ante- And Postmortem Blood Utilizing Advanced Analytical Techniques, Abdullah Hamad Alluhayb Jan 2023

Comprehensive Analysis And Forensic Investigation Of Cyanide, Thiocyanate, And 2-Amino-2-Thiazoline-4-Carboxylic Acid In-Ante- And Postmortem Blood Utilizing Advanced Analytical Techniques, Abdullah Hamad Alluhayb

Electronic Theses and Dissertations

Cyanide (CN), present as cyanide anion (CN-) or hydrogen cyanide (HCN), is a deadly poison. The main mechanism of CN toxicity is blocking terminal electron transfer, leading to cellular hypoxia, cytotoxic anoxia, and potential death. Determining blood CN concen-trations along with its major metabolite, thiocyanate (SCN-), is crucial. A sensitive method for concurrent detection of CN and SCN- from human ante- and post-mortem blood via liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was devel-oped. The method involved active microdiffusion with chemical modification using naph-thalene-2,3-dicarboxaldehyde (NDA) and taurine, while monobromobimane (MBB) mod-ification was used for SCN-. The method showed good sensitivity for …

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Understanding The Role Of Hba/Hbd Variations On Deep Eutectic Solvent Properties And Activity Using Acetylsalicylic Acid As A Model Drug, Michael Frimpong Jan 2023

Understanding The Role Of Hba/Hbd Variations On Deep Eutectic Solvent Properties And Activity Using Acetylsalicylic Acid As A Model Drug, Michael Frimpong

Electronic Theses and Dissertations

Deep eutectic solvents (DES) are emerging as a versatile class of solvents, attracting considerable attention for their unique solvent properties and potential applications. This study examines the effects of variations in combinations as well as molar ratios of hydrogen-bond acceptor (HBA) and hydrogen-bond donor (HBD) on the structure of DES. It further explores the structure-activity relationship, measured using the rate of acetylsalicylic acid (ASA) degradation in the solvent. The project is based on the model that variations in HBA/HBD combinations and their relative molar ratios impact the solvent structure (hydrogen bonding), observable in physicochemical measurements, infrared (IR), and nuclear magnetic …

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Investigating The Environmental And Molecular Dependence Of Single-Molecule Blinking-Based Multiplexing, Grace Desalvo Jan 2023

Investigating The Environmental And Molecular Dependence Of Single-Molecule Blinking-Based Multiplexing, Grace Desalvo

Dissertations, Theses, and Masters Projects

Visualizing nanoscale biological systems allows us to uncover their detailed structure and functions, which have major implications in the biomedical field. Super-resolution microscopy is a powerful tool for fluorescence imaging because, by overcoming the diffraction limit of light, it accesses structural detail with unprecedented spatial resolution. Although multicolor super-resolution imaging has been successfully implemented in many experiments, its efficiency is limited by reliance on spectral measurement for emitter identification, which limits the combinations of compatible probes to be used together. Blinking-based multiplexing (BBM) is a novel approach that circumvents the need for spectrally-distinct emitters by instead exploiting the intrinsic differences …

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Gas-Phase Proton Affinities Of Proline- And Pipecolic Acid-Containing Dipeptides, Trinh Ton Jan 2023

Gas-Phase Proton Affinities Of Proline- And Pipecolic Acid-Containing Dipeptides, Trinh Ton

Dissertations, Theses, and Masters Projects

Mass spectrometry (MS) is one of the most used techniques in proteomics because it allows for both high-throughput and quantitative analyses. Bottom-up MS-based proteomics involves breaking down proteins into smaller chains of amino acids called peptides, ionizing and fragmenting the peptides, and identifying the fragments using sequencing databases. These databases depend on the random fragmentation at the backbone peptide bond of the peptides, as predicted by the mobile proton model. Research has shown that peptides containing proline or pipecolic acid have selective fragmentations that could lead to incorrect identification in the sequencing algorithms. These selective cleavages are called “the proline …

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Bioanalytical Studies Of Disease Protein Profiles: Maldi-Tof Ms, Prajkta Satish Chivte Jan 2023

Bioanalytical Studies Of Disease Protein Profiles: Maldi-Tof Ms, Prajkta Satish Chivte

Graduate Research Theses & Dissertations

Coronavirus disease-2019 (COVID-19), which is caused by a novel coronavirus named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has ravaged the world for the past 3 years. Even today, there still exists a need for rapid, accurate, economical and non-invasive diagnostic testing platforms that yield high specificity and sensitivity towards the constantly mutating SARS-CoV-2. Research has consistently indicated saliva to be a more amenable specimen type for early detection of SARS-CoV-2, compared to the oral and nasopharyngeal swabs. Considering the limitations and high demand of the existing COVID-19 testing platforms, this dissertation work studies used MALDI-ToF MS (matrix-assisted laser desorption/ionization-time of …

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Structural Analysis Of Polar Aggregates And Inter-Ionic Distances In Room Temperature Ionic Liquids, Emily Elizabeth Dalbey Jan 2023

Structural Analysis Of Polar Aggregates And Inter-Ionic Distances In Room Temperature Ionic Liquids, Emily Elizabeth Dalbey

Graduate Research Theses & Dissertations

Ionic liquids have a wide variety of applications in chemistry due to their unique properties such as low flammability, low volatility, and high thermal and chemical stability. These properties make them great solvents, electrolytes for lithium-ion batteries, and more. Ionic liquids are salts whose components are mis-matched in size and shape leading to low melting points. To design an ionic liquid with a desired property it is key to first understand their structure. Lineshape analysis of the charge alternation peak from the experimentally measured or computationally calculated X-ray scattering data can give information about the size of the polar aggregates …

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Insight Into The Nanostructure Of “Water-In-Salt” Solutions: A Saxs/Waxs Study On Imide-Based Lithium Salts Aqueous Solutions, Xinyi Liu Jan 2023

Insight Into The Nanostructure Of “Water-In-Salt” Solutions: A Saxs/Waxs Study On Imide-Based Lithium Salts Aqueous Solutions, Xinyi Liu

Graduate Research Theses & Dissertations

The fundamental understanding of the liquid electrolytes (LEs) solvation structure and electrode-electrolyte interface behavior is important to the entire electrochemical energy storage field. Understanding the solvation structures from a few angstroms to hundreds of nanometers will undoubtedly lay a good foundation for studying the macroscopic transport properties, such as viscosity and ionic conductivity, of the LEs."Water-in-salt" electrolytes that contain 21 m lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) with excellent electrochemical and physical properties have been extensively investigated. However, the structural understanding of the LiTFSI in water is still lacking. Here, we perform synchrotron X-ray scattering to systemically study the structural variation of …

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The Effect Of S-Glutahionylation Of Keap-1/Nrf-2 And Caspase 3, Claire Greenless Jan 2023

The Effect Of S-Glutahionylation Of Keap-1/Nrf-2 And Caspase 3, Claire Greenless

Celebration of Scholarship 2023

S-glutathionylation is a form of post-translational modification where glutathione forms disulfide bonds with protein cysteine residues under oxidative conditions. The process of Sglutathionylation is important because it is a reversible process, regulates enzyme activity, and may link to disease development. In this work, under physiological conditions, KEAP-1 and NRF-2 bind together as a complex. Upon oxidative stress, NRF-2 dissociates from KEAP-1 and triggers an antioxidant response. However, the dissociation mechanism was not well studied. S-glutathionylation of KEAP-1 causes dissociation of NRF-2. This result demonstrates a possible dissociation mechanism of NRF-2. Caspase 3 is a cysteine containing protein and a key …

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Biophysical Insights Into Peptide And Alcohol Perturbations On Biomimetic Membranes, Michael Hai Nguen Jan 2023

Biophysical Insights Into Peptide And Alcohol Perturbations On Biomimetic Membranes, Michael Hai Nguen

Electronic Theses and Dissertations

Biological membranes exist in every domain of life. Life exists due to the presence of these special structures for which we take for granted. They are composed of fatty lipids and workhorse proteins and act as the premier interface of biological processes. Due to the sheer quantity and complexity within their thin boundary, studying their actions and properties pose challenges to researchers. As a result, simplified biomembrane mimics are employed regularly. We will use several types of biomembrane mimics to understand fundamental properties of membranes. In the present thesis, we also attempt to move beyond the canonical structure-based theories upon …

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Implementation Of Course Structure In Stem Courses For Student Motivation And Learning, And Lab Innovation, Muzammil Arshad, Mamoona Muzammil Jan 2023

Implementation Of Course Structure In Stem Courses For Student Motivation And Learning, And Lab Innovation, Muzammil Arshad, Mamoona Muzammil

Chemistry Faculty Publications and Presentations

The present study is an extension of implementation of the course structure which was initially designed, developed and implemented at Texas A&M University for engineering courses. This study extends its implementation to other STEM courses to assess its applicability and effectiveness in science related courses. The course structure is employed at the Chemistry department at University of Texas Rio Grande Valley (UTRGV). The present study is an autoethnography of the implementation of the course structure and its effectiveness assessment. This study highlights the implementation of the course structure considering student motivation and learning since student motivation is an important research …

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Description Of Quantum Interference Using Mixed Quantum/Classical Theory Of Inelastic Scattering, Dulat Bostan, Bikramaditya Mandal, Carolin Joy, Dmitri Babikov Jan 2023

Description Of Quantum Interference Using Mixed Quantum/Classical Theory Of Inelastic Scattering, Dulat Bostan, Bikramaditya Mandal, Carolin Joy, Dmitri Babikov

Chemistry Faculty Research and Publications

Manifestation of the quantum interference effect in the oscillation of scattering cross section is explored using the N2 + O system as a case study. Calculations are carried out for two electronic PESs of the system, for various initial rotational states of N2, in a broad range of N2 + O collision energies and using three theoretical methods: two versions of the approximate mixed quantum/classical theory (MQCT and AT-MQCT) and the accurate full-quantum coupled-channel method (implemented in MOLSCAT). A good agreement between different methods is observed, especially at high energies. Elastic scattering cross-sections oscillate as a function of …

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What Moves The Needle On Dfw Rates And Student Success In General Chemistry? A Quarter-Century Perspective, Vijay Vyas, Scott A. Reid Jan 2023

What Moves The Needle On Dfw Rates And Student Success In General Chemistry? A Quarter-Century Perspective, Vijay Vyas, Scott A. Reid

Chemistry Faculty Research and Publications

Second-term general chemistry is a key gateway course at our institution for a variety of STEM (Science, Technology, Engineering, and Mathematics) majors. Herein, we examine data on DFW% (i.e., % of D and F grades and withdrawals) in our general chemistry courses over roughly a quarter-century period, focusing on sections taught by the authors. The data are discussed in light of changes in curriculum, pedagogy, and assessments, which included introduction of recitation sections, classroom response systems (clickers), and online homework, restructuring of course content into a modular format, followed by a redesign of the course modules along an anchoring concepts …

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Impact Of A Low-Stakes Assessments Model With Retake In General Chemistry: Connecting To Student Attitudes And Self-Concept, Vijay Vyas, Llanie Nobile, James R. Gardinier, Scott A. Reid Jan 2023

Impact Of A Low-Stakes Assessments Model With Retake In General Chemistry: Connecting To Student Attitudes And Self-Concept, Vijay Vyas, Llanie Nobile, James R. Gardinier, Scott A. Reid

Chemistry Faculty Research and Publications

Across a variety of fields, the use of low-stakes assessments has led to reductions in achievement gaps and improved student success. Here, we probe the use of a low-stakes assessment model with a retake option for failed quizzes in a two-semester general chemistry sequence. We find that the quiz-retake rate in general chemistry II was significantly higher for students who had completed a retake in a general chemistry I section, and the percentage of students who failed at least one quiz in general chemistry I but passed all quizzes in general chemistry II was significantly higher for students who had …

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Molecular Understanding Of Zwitterions And Quantum Computing For Sustainability, Manh Tien Nguyen Jan 2023

Molecular Understanding Of Zwitterions And Quantum Computing For Sustainability, Manh Tien Nguyen

Theses and Dissertations--Chemical and Materials Engineering

The sustainable development of society needs sustainable energy solutions and the mitigation of greenhouse gas emissions. One key subject in this area is the development of safe and efficient ion-based batteries. Moreover, CO2 capture is a crucial pathway in mitigating emissions from the combustion of fossil fuels. Ongoing efforts are to improve both technologies' safety and efficiency. This thesis presents our efforts to conduct computational research on understanding advanced zwitterionic electrolytes and CO2 capture. Chapters 2-4 illustrate the computational research to understand ionic solvation in zwitterionic electrolytes. Solid-state electrolytes are essential for safer batteries. While solid polymer electrolytes …

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Development Of Spreadsheet-Based Simulation To Reduce Number Of Experimental Trials In Separation With Comprehensive Two-Dimensional Gas Chromatography, Chisanupong Kunmas Jan 2023

Development Of Spreadsheet-Based Simulation To Reduce Number Of Experimental Trials In Separation With Comprehensive Two-Dimensional Gas Chromatography, Chisanupong Kunmas

Chulalongkorn University Theses and Dissertations (Chula ETD)

Method development and optimization in comprehensive two- dimensional gas chromatography (GC´GC) is a process with the requirement to perform a large number of experiments maximizing the number of separated components in each sample. These are the skills which cannot be developed by students in a general lecture class; while, they can be achieved in a laboratory although with consumption of large amount of budget, energy and time. This thesis developed a spreadsheet in Microsoft Excel format to simulate a GC´GC retention time plot and a number of separated peaks for a given sample within a few milliseconds. Application of this …

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Stereoselective Synthesis Of (+)- And (-)-Cananodine, Haley Holliday Jan 2023

Stereoselective Synthesis Of (+)- And (-)-Cananodine, Haley Holliday

WWU Graduate School Collection

Natural products are an important class of molecules utilized in traditional medicine and inspire drug design in medicinal chemistry. Cananga odorata, a tree commonly known as ylang-ylang, contains natural products known to positively benefit health, and specifically promote liver health. One alkaloid isolated from Cananga odorata, cananodine, possesses cytotoxic properties, specifically against hepatocellular carcinoma (HCC). HCC is the most common type of liver cancer, with one million diagnoses projected by 2025 globally. Cananodine is a member of the guaipyridine alkaloid family, a class of compounds that feature a substituted pyridine bonded to a seven-membered ring. The first enantiomer …

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Rapid Generation Of P(V)-F Bonds Through The Use Of Sulfone Iminium Fluoride Reagents, Lucy P. Miller, James A. Vogel, Shiraz Harel, Jenna M. Krussman, Patrick R. Melvin Jan 2023

Rapid Generation Of P(V)-F Bonds Through The Use Of Sulfone Iminium Fluoride Reagents, Lucy P. Miller, James A. Vogel, Shiraz Harel, Jenna M. Krussman, Patrick R. Melvin

Chemistry Faculty Research and Scholarship

Phosphorus–fluorine bonds have become increasingly relevant in the pharmaceutical industry. To continue their exploration, more efficient synthetic methods are needed. Here, we report the application of sulfone iminium fluoride (SIF) reagents to the synthesis of P(V)–F bonds. The SIF reagents promote the deoxyfluorination of phosphinic acids in just 60 s with excellent yields and scope. The same P(V)–F products can also be synthesized from secondary phosphine oxides using an SIF reagent.

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Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody Jan 2023

Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody

Articles

The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …

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Alkyd Resins Produced From Bio-Based Resources For More Sustainable And Environmentally Friendly Coating Applications, Cemi̇l Dizman, Eli̇f Cerrahoğlu Kaçakgi̇l Jan 2023

Alkyd Resins Produced From Bio-Based Resources For More Sustainable And Environmentally Friendly Coating Applications, Cemi̇l Dizman, Eli̇f Cerrahoğlu Kaçakgi̇l

Turkish Journal of Chemistry

Recently, due to the depletion of natural resources and raising environmental and economic concerns regarding petroleum derivatives, the creation of novel ecologically friendly and sustainable materials made from bio-based and renewable resources is gaining popularity. Alkyd resins are synthetic resins in which both renewable (fatty acids, glycerol, oil, etc.) and nonrenewable (maleic anhydride, pentaerythritol, phthalic anhydride, etc.) raw materials are used in their production. Due to their superior performance (good aging, greater weather resistance and high heat resistance, outstanding gloss, etc.) over other resins, easy application, low cost, and varied use, in the coating and paint industries, they are commonly …

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Effect Of Okra Bast Fillers On Biodegradation Properties Of Poly(Vinyl Alcohol) Composites, Gazi Md Arifuzzaman Khan, Nazi̇re Deni̇z Yilmaz Jan 2023

Effect Of Okra Bast Fillers On Biodegradation Properties Of Poly(Vinyl Alcohol) Composites, Gazi Md Arifuzzaman Khan, Nazi̇re Deni̇z Yilmaz

Turkish Journal of Chemistry

This paper focuses on the effect of okra bast fillers on biodegradation of poly(vinyl alcohol) composites. Fibers were obtained from okra plant stems via biological degumming and subjected to different chemical treatments such as scouring, alkalizing, maleic anhydride treatment, and vinyl acetate grafting. The fibers were ground and PVA-okra bast filler composites were produced at 20 wt% fiber load via the solution casting method. The obtained composites were tested in terms of mechanical properties and exposed to biodegradation in soil. Effects of okra bast filler addition and chemical treatments on changes in mass, breaking strength, elasticity modulus, and breaking elongation …

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