Physical Sciences and Mathematics Commons^™

2024 World Fuel Cell Conference Held In Ningbo, Zhejiang, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

The Characterization And Electrochemistry Of Natural Uranium Dioxide Under Long-Term Disposal Conditions, Martin D. M. Badley

Electronic Thesis and Dissertation Repository

This thesis describes the studies performed on a number of natural uranium dioxide (UO₂) specimens to determine a range of reactivities. This work will support the safety case for the long-term disposal of spent nuclear fuel in Canada. Under relevant long-term disposal conditions, water radiolysis could produce oxidizing conditions at the surface of the fuel, potentially leading to fuel corrosion and the release of radionuclides into the groundwater. The rate of such a process would be determined by the radiation dose rate from the fuel and the reactivity of the fuel, which will be determined by its composition, …

Investigating The Cellular Localization, Trafficking, And Biological Function Of Ghrelin O-Acyltransferase, Sadie Xiao Hua Novak

Dissertations - ALL

Ghrelin O-acyltransferase (GOAT) catalyzes the acylation and activation of ghrelin, a peptide hormone involved in a range of physiological pathways and therapeutic target for metabolism-linked diseases such as obesity and diabetes. GOAT was determined to be localized in the membrane of the endoplasmic reticulum (ER) in early cell-based studies, but recent patient studies detected this integral membrane enzyme in blood plasma and urine. These findings challenge the current understanding of GOAT’s cellular localization, and it may provide a potential mechanism for ghrelin re-acylation by plasma membrane-resident GOAT. The work described in this dissertation aimed to define the intracellular trafficking mechanism …

An Online Nanoinformatics Platform Empowering Computational Modeling Of Nanomaterials By Nanostructure Annotations And Machine Learning Toolkits., Tong Wang, Daniel P Russo, Philip Demokritou, Xuelian Jia, Heng Huang, Xinyu Yang, Hao Zhu

College of Science & Mathematics Departmental Research

Modern nanotechnology has generated numerous datasets from in vitro and in vivo studies on nanomaterials, with some available on nanoinformatics portals. However, these existing databases lack the digital data and tools suitable for machine learning studies. Here, we report a nanoinformatics platform that accurately annotates nanostructures into machine-readable data files and provides modeling toolkits. This platform, accessible to the public at https://vinas-toolbox.com/, has annotated nanostructures of 14 material types. The associated nanodescriptor data and assay test results are appropriate for modeling purposes. The modeling toolkits enable data standardization, data visualization, and machine learning model development to predict properties and bioactivities …

Molecular Docking, Pharmacological Profiling, And Molecular Dynamics Simulation Of Potential Antihyperuricemic Agent From Secondary Metabolites Of Dillenia Philippinensis Rolfe (Dilleniaceae), Louie Rince C. Suyo, John P. Paulin, Nicole Clarence Louise L. Gapaz, Markus Brent S. Arevalo, Vince Tyrell P. Yongco, Librado A. Santiago

Karbala International Journal of Modern Science

Crystal accumulation in the joints due to increased serum uric acid (sUA) may lead to an inflammatory condition called gout. Increased sUA is caused by the excessive reabsorption of the urate anion transporter-1 (URAT-1). Therefore, URAT-1 inhibition will promote uric acid excretion and reduce the risk of having gout. Dillenia philippinensis Rolfe, often known as katmon, is an endemic plant in the Philippines with bioactive compounds associated with several therapeutic benefits. The present study represents the first scientific inquiry into the antihyperuricemic potential of compounds isolated from D. philippinensis. This study aimed to assess the interaction of URAT-1 with …

Exploring The Efficiency Of Nitrogenated Carbon Quantum Dots/Tio2 S-Scheme Heterojunction In Photodegradation Of Ciprofloxacin In Aqueous Environments, Yilmaz Ateş, Zafer Eroğlu, Özkan Açişli, Önder Meti̇n, Semra Karaca

Turkish Journal of Chemistry

The usability of polyvinyl chloride-based quaternary triethanol ammonium chloride anionite (PVC-TEAC) as a potential extractant for tungstate was investigated to recover tungstate from Gabal Qash Amir, Egypt, assaying 70.91% WO3. Structure elucidation for PVC-TEAC anionite was successfully carried out using several techniques. Experimental measurements, such as pH, agitation time, initial tungsten concentration, anionite dose, co-ions, temperature, and eluting agents, have been optimized. It was found that PVC-TEAC anionite has a maximum capacity of 63 mg per gram. From the distribution isotherm modeling, Langmuir’s model fits the experimental results better than Freundlich’s, with a theoretical value of 61.728 mg g–1. According …

Synthesis And Characterization Of New Hexahydroquinoline Derivatives, Evaluation Of Their Cytotoxicity, Intracellular Ros Production And Inhibitory Effects On Inflammatory Mediators, Ezgi̇ Pehli̇vanlar, Deni̇z Arca Çakir, Sonia Sanajou, Hülya Tezel Yalçin, Terken Baydar, Pinar Erkekoğlu, Hani̇fe Avci, Rahi̇me Şi̇mşek

Turkish Journal of Chemistry

Inflammation is a response to injury and infection in the organism. It can be categorized as acute and chronic inflammation. Chronic inflammation is the underlying cause of many diseases such as Alzheimer's, diabetes, rheumatoid arthritis, atherosclerosis and cardiovascular diseases. Recent studies have proven the anti-inflammatory properties of 1,4-dihydropyridines (1,4-DHPs) and its derivatives, which have many biological properties including calcium channel blockers. The structures of the synthesized compounds were elucidated by IR, 1H-NMR, 13C-NMR and HRMS methods. The cytotoxic properties of the compounds were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method in 3T3 cell line. Among the 15 compounds, the three compounds …

A Coarse-Grained Molecular Dynamics Study Of Gas Hydrate Formation And Dissociation, Meisam Adibifard

LSU Doctoral Dissertations

The study of gas hydrates has increased significantly over the last two decades because of their potential application in energy storage, production and transportation, water desalination, refrigeration, gas separation, etc. There is a significant interest in commercially developing natural gas hydrates because the energy content of methane hydrate reservoirs (MHRs) is at least twice that of all conventional fossil fuels combined. Additionally, due to the higher storage capacity of hydrates, it is proposed to sequester CO₂ in the form of CO₂ hydrate, thereby reducing the amount of greenhouse gases. Hence, hydrates offer a dual solution to two of …

Preparation Of A Chiral Hyperbranched Polymer Based On Cinchona Alkaloids And Investigation Of Its Catalytic Activity In Asymmetric Reactions, Rafiqul Islam, Mohammad Shahid Ullah, Abdus Salam, Shinichi Itsuno

Turkish Journal of Chemistry

Cinchona alkaloid-derived sulfonamides and ester dimers containing chiral hyperbranched polymers have been successfully synthesized and applied as catalysts in asymmetric reactions. Several hyperbranched polymers derived from cinchona alkaloids, incorporating sulfonamides and esters, were synthesized through Mizoroki–Heck coupling polymerization. These polymers were subsequently applied in enantioselective Michael addition reactions. As the prepared polymers are not soluble in frequently used organic solvents, they act as efficient catalysts in the enantioselective reaction of β-ketoesters to nitroolefins, achieving up to 99% enantioselectivity with good yields. The insoluble property allows them to better satisfy “green chemistry” requirements and be used several times without losing the …

Synthesis, Characterization, And Physico-Chemical Aspects Of A New Pvc-Based Quaternary Triethanol Ammonium Chloride Anionite For Tungsten Recovery, Bahig Atia

Turkish Journal of Chemistry

The usability of polyvinyl chloride-based quaternary triethanol ammonium chloride anionite (PVC-TEAC) as a potential extractant for tungstate was investigated to recover tungstate from Gabal Qash Amir, Egypt, assaying 70.91% WO3. Structure elucidation for PVC-TEAC anionite was successfully carried out using several techniques. Experimental measurements, such as pH, agitation time, initial tungsten concentration, anionite dose, co-ions, temperature, and eluting agents, have been optimized. It was found that PVC-TEAC anionite has a maximum capacity of 63 mg per gram. From the distribution isotherm modeling, Langmuir’s model fits the experimental results better than Freundlich’s, with a theoretical value of 61.728 mg g–1. According …

Liquefaction Optimization Of Grape Pulp Using Response Surface Methodology For Biopolyol Production And Bio-Based Polyurethane Foam Synthesis, Furkan Çolakoğlu, Emre Akdoğan, Murat Erdem

Turkish Journal of Chemistry

Both environmental and economic disadvantages of using petroleum-based products have been forcing researchers to work on environmentally friendly, sustainable, and economical alternatives. The purpose of this study is to optimize the solvothermal liquefaction process of grape pomace using response surface methodology coupled with a central composite design. After investigating the physicochemical properties of the liquified products (biopolyol) in detail, a bio-based rigid polyurethane foam (RPUF) was synthesized and characterized. The hydroxyl and acid numbers and viscosity values of all the biopolyols were analyzed. According to variance analysis results (%95 confidence range), both the reaction temperature and catalyst loading were determined …

New Imidazolidindionedioximes And Their Pt(Ii) Complexes: Synthesis And Investigation Of Their Antitumoral Activities On Breast Cancer Cells, Emrah Karahan, Tuğba Gençoğlu Katmerli̇kaya, Emel Önal, Aydan Dağ, Ayşe Gül Gürek, Vefa Ahsen

Turkish Journal of Chemistry

Breast cancer is one of the most common types of cancer worldwide and has the most lethality ratio for females among all cancers. Although current cancer therapeutics have made considerable advancements, there is still room for improvement in terms of efficacy. Many anticancer drugs have a risk of causing serious adverse effects due to their non-specific cytotoxic effects on both tumor and healthy cells. New therapeutics might have a greater ability to kill cancer cells, reduce the volume of tumors, and improve overall therapy response rates. Herein, we report the efficient synthesis and characterization of three amphi vic-dioximes and their …

Synthesis Of 3-Methyl-3-Buten-1-Ol By Supercritical Co2 In Coordination With Hzsm-5 Catalyzed Formaldehyde-Isobutene Prins Reaction, Hang Yuan, Gui-Ping Cao, Hui Lv

Turkish Journal of Chemistry

The reaction solvent and catalyst play an essential role in the Prins reaction for the synthesis of 3-methyl-3-buten-1-ol (MBO) from formaldehyde and isobutene. The reactivity of the solid base catalyzed Prins condensation reaction by formaldehyde and isobutene in supercritical CO2 was investigated using CsH2PO4 modified HZSM-5. We finds that the alkaline sites of the alkali-loaded catalyst can extract the α-H on isobutene to generate olefin carbon negative ions, while the supercritical CO2 with weak Lewis acidity can activate formaldehyde to carbon positive ions, which can combine more easily with the carbon negative isobutene to react, thus improving the reactivity of …

Magnetic Solid-Phase Extraction Technique Based On Fe3o4@Coppy-Pth Nanocomposite For Extraction Of Cobalt, Chromium, And Nickel Prior To Determination By Micro-Sample Injection System-Flame Atomic Absorption Spectrometry In Alcoholic And Nonalcoholic Beverages, Meli̇ke Küçüksakalli, Qamar Salamat, Buket Ti̇reli̇, Şükrü Gökhan Elçi̇

Turkish Journal of Chemistry

A novel Fe3O4@coPPy-PTH nanocomposite-based sorbent was prepared via in-situ oxidative polymerization using Fe3O4 nanoparticles with spherical and flower-like morphologies of thiophene and pyrrole as the feedstocks. The synthesized nanocomposite utilized sensitive extraction and determination of the metal ions Co(II), Cr(III), and Ni(II) without a chelating agent, followed by a micro-sample injection system-flame atomic absorption spectrometer (MIS-FAAS). The composition and morphology of Fe3O4@coPPy-PTH nanocomposite were characterized by advanced spectroscopic and imaging techniques like SEM and FT-IR. SEM observations showed the size of Fe3O4 nanoparticles changed from 30 nm to 120 nm in diameter after the copolymer (PPy-PTH) coating. The Fe3O4@coPPy-PTH nanocomposite …

Β-Ketoenamine-Linked Covalent Organic Framework For Efficient Iodine Capture, Onur Büyükçakir

Turkish Journal of Chemistry

Exploring the materials that effectively capture radioactive iodine is crucial in managing nuclear waste produced from nuclear power plants. Herein, a β-ketoenamine-linked covalent organic framework (bCOF) was reported as an effective adsorbent to capture iodine from both vapor and solution. bCOF's high porosity and heteroatom-rich skeleton offer a notable iodine vapor uptake capacity of up to 2.51 g g-1 at 75 oC under ambient pressure. Furthermore, after five consecutive adsorption-desorption cycles, the bCOF demonstrates a high reusability performance with a significant iodine vapor capacity retention. The adsorption mechanism was also investigated using various ex-situ structural characterization techniques, and these mechanistic …

Lacoo3 Is A Promising Catalyst For Dry Reforming Of Benzene Used As A Surrogate Of Biomass Tar, Başar Çağlar, Deni̇z Üner

Turkish Journal of Chemistry

Tar build-up is one of the bottlenecks of biomass gasification process. Dry reforming of tar is an alternative solution if oxygen chemical potential on the catalyst surface is at sufficient levels. For this purpose, an oxygen donor perovskite, LaCoO3, was used as a catalyst for dry reforming of tar. To circumvent the complexity of the tar and its constituents, benzene molecule was chosen as a model compound. Dry reforming of benzene vapour on the LaCoO3 catalyst was investigated at temperatures of 600, 700, 800 °C, at the CO2/C6H6 ratios of 3, 6, 12 and at space velocities of 14000 and …

Identification Of Blood At Simulated Crime Scenes Using Silver Nanoparticles With Sers, Uğur Köroğlu, Necdet Sağlam, Uğur Tamer, Ramazan Akcan, İsmai̇l Hakki Boyaci, Eylül Evran

Turkish Journal of Chemistry

Analysis of substances and samples obtained from the crime scene are very important in solving forensic cases. In order to determine the variables involved in a crime and to expedite the investigation process, especially the rapid analysis of body fluids in a small quantity and within an environment containing diverse components is necessary. For this reason, it is of great importance to analyse biological fluids with rapid, non-chemical contamination, non-destructive, low-cost and accurate techniques. In recent years, with advancements in laser technology, spectroscopic methods have been introduced as an analytical technique in forensic medicine and chemical studies. This study focuses …

Synthesis And Photooxygenation Of 3-(P-Substituted Phenyl)-3a,8a-Dihydro-4h-Cyclohepta[D]Isoxazoles: Facial Selectivity, Mahi̇re Emel Olgun, Abdullah Menzek, Ertan Şahi̇n, Yasi̇n Çeti̇nkaya

Turkish Journal of Chemistry

Two 3-(p-substituted phenyl)-3a,8a-dihydro-4H-cyclohepta[d]isoxazoles were synthesized by 1,3-dipolar cycloaddition of the corresponding nitrile oxides with cycloheptatriene. Two endoperoxides were synthesized as facially selective and single products in high yields (93-95%) from the reactions of isoxazole derivatives with singlet oxygen. The exact configurations of the endoperoxide with a methyl group in the phenyl ring and the diol synthesized from it were confirmed by X-ray analysis. To elucidate the mechanism, the formation energy of the endoperoxide was investigated by simulations using the software package Gaussian 09 and density functional theory calculations via the M06-2X/6-311+G(d,p) level method in dichloromethane. The results were consistent with …

Corrigendum To “Polybrominated Methoxy- And Hydroxynaphthalenes” [Turkish Journal Of Chemistry 40 (2) 2016 332-346 ], Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç

Turkish Journal of Chemistry

This corrigendum is to address an issue regarding the manuscript’s previous publication. The authors have regrettably noticed that the incorrect version of the figure and crystal data was used in the original published version of this paper. To rectify this oversight and ensure the accuracy of the published work the correct figure and data are included for your reference.

Link to the original article: https://journals.tubitak.gov.tr/chem/vol40/iss2/11/

Mild Hydrothermal Crystal Growth Strategies For Complex Inorganic Metal Fluorides, Navindra Keerthisinghe

Theses and Dissertations

Inorganic metal fluorides have been investigated for their interesting magnetic and optical properties, their electrochemical behavior, and their ionic conductivity. Fluoride materials can accommodate metals in very low oxidation states, which can be advantageous for designing new magnetic materials. Specifically, mixed metal fluorides incorporating transition metal cations often exhibit interesting magnetic behavior, such as frustrated magnetism. However, many challenges are encountered during the synthesis of such fluoride materials, including the inability to perform reactions under ambient conditions and the involvement of toxic gases for fluorination during solid-state reactions. Therefore, solution growth techniques such as mild hydrothermal synthesis are currently utilized …

Synergetic And Orthogonal Switching In Dual Photochromic Metal-Organic Frameworks, Gina Rene Wilson

Theses and Dissertations

Cooperative behavior and orthogonal responses of two classes of coordinatively integrated photochromic molecules towards distinct external stimuli were demonstrated on the first example of a photo-thermo-responsive hierarchical platform. Synergetic and orthogonal responses to temperature and excitation wavelength are achieved by confining the stimuli-responsive moieties within a metal-organic framework (MOF), leading to the preparation of a novel photo-thermo-responsive spiropyran-diarylethene based material. Synergistic behavior of two photoswitches enables the study of stimuli-responsive resonance energy transfer as well as control of the photoinduced charge transfer processes, milestones required to advance optoelectronics development. Spectroscopic studies in combination with theoretical modeling revealed a nonlinear effect …

Advances In Chalcogenide Crystal Growth, Anna Berseneva

Theses and Dissertations

Chalcogenides are the cornerstone of the semiconductor and thermoelectric industries and are up-and-coming materials for superconductors, catalysis, and battery applications. Challenges in the synthesis of those materials emerge from the chalcogen’s volatility and the tendencies of chalcogenide to react with even trace quantities of oxygen. Nonetheless, many techniques have been applied to the growth of chalcogenide single crystals, which are convenient for structure determinations and intrinsic property measurements. This dissertation will detail synthetic strategies applied to the crystal growth of novel chalcogenide materials via molten flux preparation (Chapters 2, 4, and 5), hydrothermal synthesis (Chapter 1 and 3), and single-crystal-to-single …

Metal-Organic Frameworks For Global Environmental Challenges, Kyoungchul Park

Theses and Dissertations

Over the past few decades, there has been a demand for improving nuclear waste administration due to a significant increase in the utilization of nuclear energy. The driving force for proper nuclear waste disposal is evident when considering past nuclear catastrophes—such as Chernobyl and Fukushima—where radionuclide contamination of large bodies of water sparked public concern. In order to manage such radioactive species, the emerging areas of radionuclide sequestration, storage, separation, and sensing must be addressed in the upcoming years. This dissertation presents a potential candidate for addressing these challenges, called metal-organic frameworks (MOFs). Due to their porosity, high surface area, …

Controlling Properties Of Hybrid Materials: Leaching Kinetics And Electronic Structure, Anna Berseneva

Theses and Dissertations

Hybrid materials are a unique class of materials that merge the properties of organic and inorganic building blocks. These materials are at the frontier of material science due to their wide modularity and applicability in numerous fields, ranging from catalysis to nuclear waste treatment. Unprecedented tunability of physical properties via changes in organic, inorganic moieties and their connectivity, enables for hybrid materials to address current challenges in the materials’ applications improving energy landscape.

The presented work consists of six chapters where the synthesis and design of new hybrid materials, fundamental understanding of electronic behavior and its modulation in organic-inorganic materials, …

Mechanism Of Iron-Catalyzed Oxidative Α-Amination Of Ketones With Sulfonamides, Gloria M. Parrales, Nina C. Hollin, Fubin Song, Yangyang Lyu, Anne-Marie O. Martin, Alexandra E. Strom

Chemistry: Faculty Publications

We report the mechanism of the iron-catalyzed oxidative α-amination of ketones with sulfonamides. Using linear free energy relationships, competition experiments, and identification of reaction intermediates, we have found that the mechanism of this reaction proceeds through rate-limiting electron transfer to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) from an iron enolate in the process of forming an α-DDQ adduct. The adduct then serves as the electrophile for substitution with sulfonamide nucleophiles, accelerated by iron and additional DDQ. This mechanistic study rules out formation of an α-carbocation intermediate and purely radical mechanistic hypotheses.

Electronic Structure Investigation Of Photoswitch-Embedded Organic Frameworks And External Electric Field Effects On Carbon Dioxide, Austin Hill

Theses and Dissertations

Metal- and Covalent-Organic Frameworks (MOFs and COFs, respectively) are chemically versatile systems that have diverse applications, ranging from drug delivery to energy storage. This versatility is due to the highly tunable nature of organic frameworks, which utilize metal clusters, chemically diverse metals, and organic ligands. Researchers have recently demonstrated how MOFs and COFs can be remotely tuned through the use of photochromic organic linkers and light (Martin, et al., 2022). The implications of these findings are significant and have numerous applications, primarily in optical switching and energy storage. However, the photochromic mechanism within the organic framework must be investigated, which …

Molecular And Hybrid Catalysts For Selective Hydrodeoxygenation Of Lignin Model Compounds, Jacob G. Tillou

Theses and Dissertations

Lignin is a highly aromatic, branched polymer and could be utilized as a renewable source of liquid fuel. The advent of “lignin-first” depolymerization processes have allowed for the high-yield isolation of oxygenated aromatic monomers from lignin. These oxygenated aromatic compounds are lower in energy and stability than their deoxygenated counterparts. Selective deoxygenation of these compounds would result in stable, higher value liquid fuels. Using molecular catalysts, selective deoxygenation, or hydrodeoxygenation (HDO), of lignin-derived compounds in the presence of hydrogen is possible.

Immobilization of these molecular catalysts on metal oxide surfaces eliminates the possibility of bimolecular decomposition and allows for easier …

Molecular Rotors For Quantifying Kinetic Effects Of Stabilizing Non-Covalent Interactions, Binzhou Lin

Theses and Dissertations

This thesis describes the development of molecular machines as analytical instruments to measure the strength of non-covalent interactions and to test hypotheses of reaction mechanisms. The first chapter is a review of molecular rotors. The second chapter presents the development of a molecular rotor that can be controlled using electrostatic interactions. Previous examples have used electrostatic interactions to slow down or inhibit molecular motion. Our system is activated and sped up using electrostatic interactions. The third and fourth chapters describe the application of molecular rotors designed to experimentally measure the strength and stability trends for non-covalent pnictogen and chalcogen interactions. …

Impaired Waters: New Treatments And Improved Methods For Pfas And Algae Toxins, Alexandria Forster

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS) are high-profile environmental contaminants, many having long persistence in the environment and widespread presence in humans and wildlife. Following phase-out of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in North America and restrictions in Europe, PFAS replacements are now widely found in the environment. While liquid chromatography (LC)-mass spectrometry (MS) is typically used for measurement, much of the PFAS is missed. To more comprehensively capture organic fluorine, we developed sensitive and robust methods using activated carbon adsorption, solid phase extraction, and combustion ion chromatography (CIC) to measure total organic fluorine (TOF) in industrial wastewaters, river …

Northern Fur Ssal Vibrissae Organochlorine Contaminant Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …