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Articles 1861 - 1890 of 34530

Full-Text Articles in Physical Sciences and Mathematics

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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Effect Of Carbon Fiber Reinforcement On Dimensional Variations Of 3d Printed Polyamide-6 Composites: A Simulation Study, Ans Al Rashid, Hamid Ikram, Muammer Koç Jan 2023

Effect Of Carbon Fiber Reinforcement On Dimensional Variations Of 3d Printed Polyamide-6 Composites: A Simulation Study, Ans Al Rashid, Hamid Ikram, Muammer Koç

Turkish Journal of Chemistry

Due to material design and fabrication flexibility, additive manufacturing (AM) or 3D printing (3DP) processes and polymer composites have paved their way into several industrial sectors. The quality of 3D printed polymer composites is highly dependent on the reinforcement content of polymers and 3DP process parameters. Several experimental studies are performed to optimize the reinforcement contents and process parameters; however, exploring the numerical modeling and simulation techniques is vital to lower the research and development costs. In the study, the numerical simulations for the 3DP process were performed using Digimat® software for carbon fiber-reinforced polyamide-6 (PA6) composites fabricated via the …

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Effect Of Calcium Carbonate Particle Size And Content On The Thermal Properties Of Pvc Foamed Layer Used For Coated Textiles, Mouna Stambouli, Walid Chaouch, Sondes Gargoubi, Riadh Zouari, Slah Msahli Jan 2023

Effect Of Calcium Carbonate Particle Size And Content On The Thermal Properties Of Pvc Foamed Layer Used For Coated Textiles, Mouna Stambouli, Walid Chaouch, Sondes Gargoubi, Riadh Zouari, Slah Msahli

Turkish Journal of Chemistry

The goal of this research is to see how the amount and particle size of calcium carbonate (CaCO$_{3}$) used in the foamed layer in use for PVC-coated textiles affects the thermal properties of the material. Two different particle sizes were used at various concentrations. The impact of different CaCO$_{3}$ loadings and particle sizes on the PVC foamed layer's thermal properties were examined. Thermogravimetry (TGA and DTG) and differential scanning calorimetry (DSC) measurements were utilized to investigate the thermal properties of the PVC foamed layer and the samples have been also characterized by FTIR spectroscopy. According to the findings, the thermal …

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Electrically Assisted Solution Blow Spinning Of Pvdf/Tpu Nanofibrous Mats For Air Filtration Applications, Andinet Kumella Eticha, Ali̇ Toptaş, Yasi̇n Akgül, Ali̇ Kiliç Jan 2023

Electrically Assisted Solution Blow Spinning Of Pvdf/Tpu Nanofibrous Mats For Air Filtration Applications, Andinet Kumella Eticha, Ali̇ Toptaş, Yasi̇n Akgül, Ali̇ Kiliç

Turkish Journal of Chemistry

In this study, pure polyvinylidene fluoride (PVDF), pure thermoplastic polyurethane (TPU), and PVDF/TPU blend nanofibers (1:3, 2:2, 3:1 ratios) were produced via electrically assisted solution blow spinning for air filtration applications. Scanning electron microscopy (SEM) analysis was conducted to investigate the diameters and morphology of nanofibers. The filtration performance of nanofibrous mats was examined by air filtration test with challenging with 0.26 ± 0.07 μm salt particles. Moreover, the flexibility and strength of the samples were determined via tensile tests. Results showed that pure TPU nanofibers had better mechanical properties, while pure PVDF nanofibers showed better filtration performance. However, 3PVDF/1TPU …

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Investigating The Effect Of Poly (Ε-Caprolactone) Nanofibers Scaffolds With Random, Unidirectionally, And Radially Aligned Morphologies On The Fibroblast Cell?S Attachment And Growth Behavior, Saeed Nezari, Mohammadamin Sarli, Ahmad Hivechi, Hajir Bahrami, Peiman B. Milan, Noorahmad Latifi, Fatemeh Latifi, Tayyeb Ghadimi, S. Mohammad Amin Haramshahi, Soheila Naderi Gharahgheshlagh Jan 2023

Investigating The Effect Of Poly (Ε-Caprolactone) Nanofibers Scaffolds With Random, Unidirectionally, And Radially Aligned Morphologies On The Fibroblast Cell?S Attachment And Growth Behavior, Saeed Nezari, Mohammadamin Sarli, Ahmad Hivechi, Hajir Bahrami, Peiman B. Milan, Noorahmad Latifi, Fatemeh Latifi, Tayyeb Ghadimi, S. Mohammad Amin Haramshahi, Soheila Naderi Gharahgheshlagh

Turkish Journal of Chemistry

In the last decade, significant progress in tissue engineering, repairing, and replacing organs has been achieved. The design and production of scaffolds for tissue engineering are one of the main areas which have attracted the researcher's interest. In this regard, electrospinning is one of the most popular methods of nanoscale scaffold similar to extracellular matrix production. This paper reports the fabrication of scaffolds consisting of radially aligned PCL nanofibers by utilizing a collector composed of a central point electrode and a peripheral ring electrode. The chemical and physical properties were compared using SEM, FTIR, XRD, and DSC experiments, as well …

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Surface Modification Of Polypropylene Nonwoven With Chitosan, Tio$_{2}$, And Ag Nanoparticles For The Removal Of Acid Dye From Water, Aminoddin Haji, Mohsen Hadizadeh, Masoumeh Ferdosi Jan 2023

Surface Modification Of Polypropylene Nonwoven With Chitosan, Tio$_{2}$, And Ag Nanoparticles For The Removal Of Acid Dye From Water, Aminoddin Haji, Mohsen Hadizadeh, Masoumeh Ferdosi

Turkish Journal of Chemistry

In this study, polypropylene nonwoven was coated with chitosan after being activated by oxygen/argon low-pressure plasma. The chitosan-treated sample (PP-Ch) was coated with TiO$_{2}$ nanoparticles by a pad-dry method. Silver nanoparticles were in situ synthesized on the chitosan-TiO$_{2}$-coated sample by a chemical reduction method. The morphology of each of the samples mentioned above was evaluated by FESEM. The efficiency of each sample in the removal of C.I. Acid Brown 248 from aqueous media was evaluated. The PP-Ch sample removed 90% of the dye at pH=3. Coating the PP-Ch sample with TiO$_{2}$ and silver nanoparticles improved the dye removal efficiency under …

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Copper-Catalyzed Reactions Of Β-Alkoxy/Phenoxy Enones With Dimethyl Diazomalonate, Füsun Şeyma Kişkan Jan 2023

Copper-Catalyzed Reactions Of Β-Alkoxy/Phenoxy Enones With Dimethyl Diazomalonate, Füsun Şeyma Kişkan

Turkish Journal of Chemistry

2,3-dihydrofurans were synthesized from carbonyl-ylides via 1,5-electrocyclization reactions with high yields. Dimethyl diazomalonate was reacted with several β-alkoxy and/or β-phenoxy α,β-unsaturated compounds in the presence of Cu(acac)$_{2}$ as a catalyst. From the reaction of β-methoxy enone with diazo compound, dioxole, and Cα-H insertion products were also obtained as side products along with 2,3-dihydrofuran derivative. When the unsaturated compound has an ester and a ketone group, only one dihydrofuran derivative was formed, which occurred by the 1,5-ring closure of keto-carbonyl ylide. Dihydrofuran derivative from the formation of ester carbonyl ylide in the reactions was not obtained.

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Catalytic Evaluation Of Cellulose Pyrolysis By Using Nanosized Metal Oxide Catalysts, Yusuf Osman Donar, Ali̇ Tolga Ünalan, Samed Ergenekon, Ali̇ Sinağ Jan 2023

Catalytic Evaluation Of Cellulose Pyrolysis By Using Nanosized Metal Oxide Catalysts, Yusuf Osman Donar, Ali̇ Tolga Ünalan, Samed Ergenekon, Ali̇ Sinağ

Turkish Journal of Chemistry

In this study, effects of TiO$_{2}$ and ZnO nanometal oxides on cellulose pyrolysis have been investigated. Both catalysts have been synthesized via hydrothermal method and characterized by using different techniques. Catalytic and catalyst-free experiments were carried out so as to identify the catalytic abilities of synthesized nanoparticles. Catalyst-free experiments were carried out at 500, 600, and 700 °C in order to determine the optimal condition for pyrolysis and it was found as 700 °C. Optimum catalyst ratio for cellulose pyrolysis was found as 5% (w/w) for both TiO$_{2}$ and ZnO catalysts. GC-MS and micro-GC analyses were conducted in order to …

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Evaluation Of Photochemically Cross-Linked Collagen/Gold Nanoparticle Composites As Potential Skin Tissue Scaffolds, Evri̇m Meri̇ç Yelkuvan, Özge Erdemli̇, Bengi̇ Yilmaz, Ömer Aktürk Jan 2023

Evaluation Of Photochemically Cross-Linked Collagen/Gold Nanoparticle Composites As Potential Skin Tissue Scaffolds, Evri̇m Meri̇ç Yelkuvan, Özge Erdemli̇, Bengi̇ Yilmaz, Ömer Aktürk

Turkish Journal of Chemistry

Collagen type I is the main structural unit in skin tissue and is therefore used preferentially in skin tissue scaffolds. However, collagen-based 3D scaffolds have weak aqueous stability and degradation profiles in their uncross-linked states and chemical cross-linking reagents arise toxicity concerns, which generally restrict the spectrum of their biomedical applicability. Here, the research goal is to photochemically cross-link collagen type I with rose bengal (RB) when subjected to green laser light and to investigate the effect of silk sericin-capped gold nanoparticles (S-AuNP) when incorporated into scaffolds on the cross-linking process and thus on the scaffold properties. All the collagen …

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Electrochemical Determination Of Aripiprazole Based On Aluminium Oxide Nanoparticles Modified Carbon Paste Electrode, Funda Öztürk, Eli̇f Yüksel, Pinar Esra Erden, Esma Kiliç Jan 2023

Electrochemical Determination Of Aripiprazole Based On Aluminium Oxide Nanoparticles Modified Carbon Paste Electrode, Funda Öztürk, Eli̇f Yüksel, Pinar Esra Erden, Esma Kiliç

Turkish Journal of Chemistry

The electrochemical oxidation of aripiprazole was explored at a carbon paste electrode modified with aluminium oxide nanoparticles by cyclic voltammetry and square-wave anodic adsorptive stripping voltammetry. Experimental parameters such as carbon paste composition, scan rate, buffer pH, accumulation time, and accumulation potential were optimized in order to obtain high analytical performance. The incorporation of aluminium oxide nanoparticles into the carbon paste matrix enhanced the effective surface area of the carbon paste electrode and improved the sensitivity. On the aluminium oxide nanoparticles modified carbon paste electrode, aripiprazole exhibited an irreversible anodic peak at +1.17 V in pH 1.8 BR buffer solution. …

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Polymeric Nanoparticle-Based Electrochemical Sensor For The Detection Of Ca 125, Ceren Türkcan, Si̇nan Akgöl Jan 2023

Polymeric Nanoparticle-Based Electrochemical Sensor For The Detection Of Ca 125, Ceren Türkcan, Si̇nan Akgöl

Turkish Journal of Chemistry

In this paper, Cys-graft-p(HEMA) nanomaterials and a new electrochemical method were developed for determination of CA 125. Cys-graft-p(HEMA) nanomaterials were synthesized with emulsion polymerization method and modified with grafting procedure. It was determined that Cys-graft-p(HEMA) nanomaterials had 50 nm dimension and spherical morphology, and per gram polymeric material contained 0.011 mmol L-cysteine. Electrode surface was prepared step by step for electrochemical analysis with optimization process. Linear determination range was determined as 5-400 U/mL (R= 0.9935). Detection limit (LOD) was calculated as 1.87 U/mL, and quantification limit (LOQ) was determined as 5.62 U/mL. The fabricated sensor system showed good repeatability, accuracy, …

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Structure-Emission Relationship Of Some Coumarin Laser Dyes And Related Molecules: Prediction Of Radiative Energy Dissipation And The Intersystem Crossing Rate Constants, Msa Abdelmottaleb Jan 2023

Structure-Emission Relationship Of Some Coumarin Laser Dyes And Related Molecules: Prediction Of Radiative Energy Dissipation And The Intersystem Crossing Rate Constants, Msa Abdelmottaleb

Turkish Journal of Chemistry

Dye lasers are commonly used in optical investigation because their solutions in organic solvents deliver tunable, coherent emissions. They exhibit intense fluorescence owing to some specific spectroscopic characteristics. One drawback of the laser dyes is that it shows excessive triplet-state losses (TSLs.) The lack of theoretical predictions of fluorescence rates, intersystem crossing (ISC), and phosphorescence in laser dyes prompted us to report on the predicted rates of radiative and nonradiative transitions of some laser dyes. Structural engineering by some substituents influencing the simulated rates of coumarin laser dye derivatives for an efficient operation was investigated. The NH$_{2}$ functional group renders …

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Carbon Quantum Dots And Chitosan-Based Heterogeneous Silver Catalyst For Reduction Of Nitroaromatic Compounds, Farah Sami̇r Sali̇m, İdri̇s Sargin, Gülşi̇n Arslan Jan 2023

Carbon Quantum Dots And Chitosan-Based Heterogeneous Silver Catalyst For Reduction Of Nitroaromatic Compounds, Farah Sami̇r Sali̇m, İdri̇s Sargin, Gülşi̇n Arslan

Turkish Journal of Chemistry

Chitosan plays a crucial role in catalysis, environmental remediation, and sustainable chemistry as a renewable and cationic polysaccharide. Chitosan-based metal catalysts are used in a broad range of chemical transformations. In the study, carbon quantum dots (CQDs) were derived from Momordica charantia fruits by microwave irradiation following a green chemistry approach. Three catalysts were designed: Ag(0)-chitosan, Ag(0)-chitosan-M. charantia fruit powder, and Ag(0)-chitosan-CQDs. The catalyst supports were prepared by stabilizing CQDs or M. charantia powder within the polymeric matrix of chitosan beads. Metallic silver particles were anchored onto glutaraldehyde cross-linked chitosan beads from the aqueous solution of silver nitrate. The …

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Design, Synthesis, And Enzyme Inhibition Evaluation Of Some Novel Mono- And Di-O-Ss-D-Glycopyranosyl Chalcone Analogues With Molecular Docking Studies, Gonca Çeli̇k, Gi̇zem Tatar Yilmaz, Hüseyi̇n Şahi̇n, Burak Barut, Nuretti̇n Yayli Jan 2023

Design, Synthesis, And Enzyme Inhibition Evaluation Of Some Novel Mono- And Di-O-Ss-D-Glycopyranosyl Chalcone Analogues With Molecular Docking Studies, Gonca Çeli̇k, Gi̇zem Tatar Yilmaz, Hüseyi̇n Şahi̇n, Burak Barut, Nuretti̇n Yayli

Turkish Journal of Chemistry

In this study, some novel mono- and di-O-β-D-glycopyranosyl chalcone analogs were designed, synthesized, and characterized. The chalcone derivatives were synthesized with good yields by base-catalyzed Claisen-Schmidt condensation in EtOH solution. Then these chalcones were reacted with TAGBr (2,3,4,6-tetra-O-acetyl-μ-D-glucopyranosylbromide) in dry acetone under the anhydrous condition at 0-5 °C. Deacylated was carried out by the Zemplen's method with NaOCH3 in dry methanol results in substituted chalcone-O-glycosides (mono- and di-O-β-D-glycopyranosyl chalcone analogs). The chemical structures of all synthesized compounds were elucidated based on IR, NMR spectral data, and mass spectrometry. Further, the compounds (7a-c, 8a-c, 12a-c, 16a-c, and 17a-c) …

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Synthesis And Kinetic Analysis Of Poly(N-Acryloylmorpholine) Brushes Via Surface Initiated Raft Polymerization, Esma Mutlutürk, Tuncer Çaykara Jan 2023

Synthesis And Kinetic Analysis Of Poly(N-Acryloylmorpholine) Brushes Via Surface Initiated Raft Polymerization, Esma Mutlutürk, Tuncer Çaykara

Turkish Journal of Chemistry

Polymer brushes are promising many applications as smart materials and biocompatible surfaces. Surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization is one of the most effective techniques for synthesis of well-defined polymer brushes. Herein, a biocompatible, uniform and stable poly(N-acryloylmorpholine)-silicon hybrid system was achieved using surface-initiated RAFT polymerization. Evidence of a well-controlled surface-initiated RAFT polymerization was confirmed by a linear increase of number average molecular weight (M$_{n}$) with overall monomer conversions. Water contact angle, ellipsometry, X-ray photoelectron spectroscopy and atomic force microscopy verified the presence of poly(N-acryloylmorpholine) (poly(NAM)) on silicon wafers. The grafting density (σ) and the average distance between grafting …

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Synthesis And Characterization Of Nicr$_{2}$O$_{3}$- Ceo$_{2nrs}$ Anode Electrocatalyst For Ethanol Electrooxidation Reaction In Alkaline Media, Emi̇ne Sena Kazan, Mahmut Rahi̇m Bayramoğlu Jan 2023

Synthesis And Characterization Of Nicr$_{2}$O$_{3}$- Ceo$_{2nrs}$ Anode Electrocatalyst For Ethanol Electrooxidation Reaction In Alkaline Media, Emi̇ne Sena Kazan, Mahmut Rahi̇m Bayramoğlu

Turkish Journal of Chemistry

In this paper, ceria (CeO$_{2}$) nanorod (NR) supported Ni-Cr$_{2}$O$_{3}$ anode electrocatalysts were synthesized as nonnoble metalbased anode electrocatalysts for ethanol electrooxidation reaction (EOR) in alkaline media. Physicochemical characterization of the electrocatalysts was investigated by XRD, SEM, and TEM techniques. Electrochemical performances of the catalysts were investigated via cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA) techniques. The data from linear LSV were used for the diffusion coefficient of the electrocatalysts. The CA experiments' results showed the tolerance for catalytic poisoning and durability of the synthesized electrocatalysts.

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Fabrication Of Dendritic Pdcu Alloy Supported On 3d N-Doped Hollow Graphene For Efficient Ethanol Electrooxidation, Zhijie Ji̇ang, Shuiyuan Fu, Wei Zhao, Xvtang Liu, Fei Wang, Mingyu Cui, Linyang Dong Jan 2023

Fabrication Of Dendritic Pdcu Alloy Supported On 3d N-Doped Hollow Graphene For Efficient Ethanol Electrooxidation, Zhijie Ji̇ang, Shuiyuan Fu, Wei Zhao, Xvtang Liu, Fei Wang, Mingyu Cui, Linyang Dong

Turkish Journal of Chemistry

Fabricating highly efficient Pd-based nanocatalysts with a well-defined structure is desired for the commercialization of direct ethanol fuel cell (DEFC). Herein, a series of hierarchical three-dimensional N-doped hollow graphene spheres (NHGS) supported dendritic PdCu alloy catalysts Pd$_{x}$Cu$_{(d)}$-NHGS (x: Cu/Pd theoretical molar ratio of 4, 2, and 1) are assembled by one-pot ascorbic acid reduction-immobilization method. Aiming to maximize the Pd utilization and realize the efficient ethanol electrooxidation, this novel electrocatalyst offers potent activity sites and promotes electron and ion kinetics simultaneously. Characterization indicates that the as-obtained Pd$_{4}$Cu$_{(d)}$ alloy nanoparticles with average sizes of approximately 55 nm are evenly dispersed on …

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Investigation Of The Dehydration Of Ulexite Ore With Different Parameters And Modeling With Artificial Neural Network (Ann) Method, Mustafa Engi̇n Kocadaği̇stan Jan 2023

Investigation Of The Dehydration Of Ulexite Ore With Different Parameters And Modeling With Artificial Neural Network (Ann) Method, Mustafa Engi̇n Kocadaği̇stan

Turkish Journal of Chemistry

Study experiments were conducted considering the temperature, time, and sample weight parameters in order to model the dehydration by applying dehydration processes to ulexite ores. Data obtained from the dehydration processes of ulexite ore were compared with TG analyzes. It was observed as the result of the heat treatment that the fastest water removal was provided in the temperature range of 150-250 °C and it was very low in the range of 400-750 °C. In order to design the ANN method, 4 different models were proposed with the same parameters in the dehydration experiments and the network structure was determined. …

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Effect Of Microfluidic Channel Integration Onto Gold Microelectrode On Its Redox Electrochemistry, Ahmet Uçar, Zahraa Ali Hajool, Hamed Ghorbanpoor, Reza Didarian, Fatma Doğan Güzel Jan 2023

Effect Of Microfluidic Channel Integration Onto Gold Microelectrode On Its Redox Electrochemistry, Ahmet Uçar, Zahraa Ali Hajool, Hamed Ghorbanpoor, Reza Didarian, Fatma Doğan Güzel

Turkish Journal of Chemistry

Microfluidic systems have attracted significant interest in recent years as they are extensively employed in lab-on-chip and organ-on-chip research. Their combination with electrochemical platforms offers many advantages, promising a high potential for sensing applications, still the microfluidic-channel integration onto electrodes might induce challenges related to changes in signal-tonoise ratios and mass transport conditions. In this study, we investigated the effect of microfluidic channel integration in redox behavior of thermally deposited gold thin film microelectrodes by voltammetric (CV and SWV) electrochemical measurements. Using different dimensions of PDMS microfluidic channels (i.e. widths of 50, 100, 250, and 500 μm) and a constant …

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Enhanced Ionic Conductivity And Mechanical Strength In Nanocomposite Electrolytes With Nonlinear Polymer Architectures, Recep Bakar, Saeid Darvishi, Erkan Şenses Jan 2023

Enhanced Ionic Conductivity And Mechanical Strength In Nanocomposite Electrolytes With Nonlinear Polymer Architectures, Recep Bakar, Saeid Darvishi, Erkan Şenses

Turkish Journal of Chemistry

Solvent-free polymer-based electrolytes (SPEs) have gained significant attention to realize safer and flexible lithium-ion batteries. Among all polymers used for preparing SPEs electrolytes, poly(ethylene oxide), a biocompatible and biodegradable polymer, has been the most prevalent one mainly because of its high ionic conductivity in the molten state, the capability for the dissolution of a wide range of different lithium salts as well as its potential for the environmental health and safety. However, linear PEO is highly semicrystalline at room temperature and thus exhibits weak mechanical performance. Addition of nanoparticles enhances the mechanical strength and effectively decreases the crystallization of linear …

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Synthesis, Molecular Simulation Studies, In Vitro Biological Assessment Of 2-Substituted Benzoxazole Derivatives As Promising Antimicrobial Agents, Gajanan S. Shanbhan, Amit Bhargava, Giridhar Pal Singh, Shrinivas D. Joshi, Narendra Chundawat Jan 2023

Synthesis, Molecular Simulation Studies, In Vitro Biological Assessment Of 2-Substituted Benzoxazole Derivatives As Promising Antimicrobial Agents, Gajanan S. Shanbhan, Amit Bhargava, Giridhar Pal Singh, Shrinivas D. Joshi, Narendra Chundawat

Turkish Journal of Chemistry

The 2-substituted benzoxazole derivatives are known to exhibit a wide spectrum of biological potential. Two series of novel benzoxazole derivatives containing 2-phenyl and 2-N-phenyl groups were synthesized, by following the green chemistry approach. All the newly synthesized derivatives were screened against gram-positive bacteria (Streptococcus pyogenes, Staphylococcus aureus), gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli) and the fungus (Aspergillus clavatus and Candida albicans). Most of these compounds have demonstrated potent antibacterial activities, especially against E. coli at 25 μg/mL, along with moderate antifungal activity. Among these, two compounds, 21 and 18, showed interesting antibacterial profile. Molecular …

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Inclusion Complexes Of Squalene With Beta-Cyclodextrin And Methyl-Beta-Cyclodextrin: Preparation And Characterization, Anh Van Nguyen, Victor Ivanovic Deineka, Anh Thi Ngoc Vu, Tuan Dinh Le, Hieu Tran Trung, Tien Anh Nguyen Jan 2023

Inclusion Complexes Of Squalene With Beta-Cyclodextrin And Methyl-Beta-Cyclodextrin: Preparation And Characterization, Anh Van Nguyen, Victor Ivanovic Deineka, Anh Thi Ngoc Vu, Tuan Dinh Le, Hieu Tran Trung, Tien Anh Nguyen

Turkish Journal of Chemistry

The present work aimed to investigate inclusion complexes of squalene with various cyclodextrins (native ß-cyclodextrin and methyl-ß-cyclodextrin). The production of squalene-ß-cyclodextrin inclusion complex was obtained using Response Surface Methodology and obtained inclusion complexes were studied with FTIR spectroscopy, X-ray diffractometry, thermal analysis, and 1H-NMR spectrometry. At the same time, squalene content was determined by reversed-phase high-performance liquid chromatography. All results confirmed that squalene was successfully involved in the cyclodextrin cavities. Optimizing the condition in preparation for the squalen-ß-cyclodextrin inclusion complex yielded 54.3% with squalene content of 9.01%. The essential difference for the inclusion complex of squalene with methylated beta-cyclodextrin was …

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