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2023

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Articles 271 - 283 of 283

Full-Text Articles in Chemistry

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. …


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 …


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 …


Synthesis Of Pyridinium-Based Ionic Liquids And Their Application To Improve Candida Rugosa Lipase Stability In A Methanol-Water Solvent System, Oktavianus Cipta, Anita Alni, Rukman Hertadi Jan 2023

Synthesis Of Pyridinium-Based Ionic Liquids And Their Application To Improve Candida Rugosa Lipase Stability In A Methanol-Water Solvent System, Oktavianus Cipta, Anita Alni, Rukman Hertadi

Turkish Journal of Chemistry

This paper studied the effect of pyridinium-based ionic liquids as cosolvents in a methanol-water solvent system on the hydrolytic activity of Candida rugosa lipase. These ionic liquids were successfully synthesized using imidazolium-based ionic liquid synthesizing methods with a certain adjustment. The hydrolytic activity of Candida rugosa lipase was analyzed using 4-nitrophenol acetate (pNPA) and 4-nitrophenol palmitate (pNPP) as substrates. The addition of ionic liquids had no significant effect on the hydrolytic activity of lipase in a water solvent, and it had a greater effect in methanol. The addition of [C6Py] Br ionic liquid as a methanol cosolvent (methanol: ionic liquid, …


Sars-Cov-2 Main Protease Targeting Potent Fluorescent Inhibitors: Repurposing Thioxanthones, Gönül Saadet Batibay, Eyüp Meti̇n Jan 2023

Sars-Cov-2 Main Protease Targeting Potent Fluorescent Inhibitors: Repurposing Thioxanthones, Gönül Saadet Batibay, Eyüp Meti̇n

Turkish Journal of Chemistry

The coronavirus disease, COVID-19, is the major focus of the whole world due to insufficient treatment options. It has spread all around the world and is responsible for the death of numerous human beings. The future consequences for the disease survivors are still unknown. Hence, all contributions to understand the disease and effectively inhibit the effects of the disease have great importance. In this study, different thioxanthone based molecules, which are known to be fluorescent compounds, were selectively chosen to study if they can inhibit the main protease of SARS-CoV-2 using various computational tools. All candidate ligands were optimized, molecular …


The Effect Of Poss Nanoparticles On Crosslinking Of Styrene-Butadiene Rubber Nanocomposites, Seda Beki̇n Açar, Mehmet Ati̇lla Taşdelen, Bağdagül Karaağaç Jan 2023

The Effect Of Poss Nanoparticles On Crosslinking Of Styrene-Butadiene Rubber Nanocomposites, Seda Beki̇n Açar, Mehmet Ati̇lla Taşdelen, Bağdagül Karaağaç

Turkish Journal of Chemistry

The effect of octaisobutyl-polyhedral oligomeric silsesquioxane (OIB-POSS) as a nanosized reinforcement on the cure kinetics, crosslinking density, and mechanical properties of styrene-butadiene rubber (SBR) nanocomposites was examined in this study. For this purpose, SBR compounds with various OIB-POSS nanoparticle loadings at 1, 3, and 5 phr were prepared and their results were compared with a reference compound without OIB-POSS. When 1 phr of OIB-POSS was added to the rubber matrix, the elongation at break values and tensile strength of the corresponding nanocomposite increased by 24.1% and 29.2% compared to the reference sample, respectively. The presence of OIB-POSS nanoparticles and their …


In Vitro Tyrosinase Inhibitory, Dna Interaction Studies, And Lc?Hrms Analysis Of Ficus Carica Leaves, Güli̇n Renda, Burak Barut, Rümeysa Ceren, Enes Aydin Jan 2023

In Vitro Tyrosinase Inhibitory, Dna Interaction Studies, And Lc?Hrms Analysis Of Ficus Carica Leaves, Güli̇n Renda, Burak Barut, Rümeysa Ceren, Enes Aydin

Turkish Journal of Chemistry

Turkey is the world?s leading producer of figs, a typical Mediterranean fruit. The fig, Ficus carica L. (Moraceae), has been widely cultivated since ancient times due to the nutritional value of its fruits. It was aimed to investigate the phytochemical characterization and biological properties of F. carica leaf extracts in order to determine their potential for use in the treatment of various diseases. F. carica leaves were extracted in 70% methanol at 40 °C under reflux. To obtain extracts of different polarities, the crude extract was fractionated with n-hexane, dichloromethane, and n-butanol. Phenolic content was determined using liquid chromatography?high resolution …


A New Method In The Synthesis Of Conductive Polymers; Synthesis, Characterization, And Investigation Of Photocatalytic Properties Of Polyaniline, Muzaffer Can Jan 2023

A New Method In The Synthesis Of Conductive Polymers; Synthesis, Characterization, And Investigation Of Photocatalytic Properties Of Polyaniline, Muzaffer Can

Turkish Journal of Chemistry

As known, in the synthesis of conductive polyaniline polymer from aniline monomer, the polymerization medium must be acidic. In order to make the polymerization medium acidic, protonic acids such as HCl and H2SO4 are generally used. In this study, two acids have been used to make the polymerization medium acidic. One of them, as we know, is H2SO4 as a protonic acid. The other acid is the zinc ion, which is a Lewis acid. The metal ion has never been used for this purpose up to now. Two polyaniline polymers have been synthesized to prove that conductive polymers can also …


Modelling And Simulation Of Chemical Reaction Of Porous Mgcl2 Pellets With Nh3 By Including Impact Of Heat And Mass Transfer And Structure Change, Zeynep Karakaş Helvaci, Gürkan Karakaş, Yusuf Uludağ Jan 2023

Modelling And Simulation Of Chemical Reaction Of Porous Mgcl2 Pellets With Nh3 By Including Impact Of Heat And Mass Transfer And Structure Change, Zeynep Karakaş Helvaci, Gürkan Karakaş, Yusuf Uludağ

Turkish Journal of Chemistry

The MgCl2?NH3 reactive system is investigated in terms of heat and mass transfer coupled with chemical reaction through numerical simulation. The reversible nature of the chemical reaction is captured by including adsorption and desorption terms in the rate expression simultaneously. The kinetic coefficients of the adsorption are directly adopted from the literature, while those for the desorption reaction are calculated based on the thermodynamic relations. The impact of changing pressure and pellet porosity are also investigated in the simulations. The initial temperature of the pellet is 300 K in all simulations. Temperature, NH3 pressure, and conversion distributions in the pellets, …


Spectrophotometric Quantification Of Paracetamol And Tramadol Hydrochloride By Chemometric Calibration Methods, Faysal Seli̇moğlu, Nermi̇n Pinarcik Jan 2023

Spectrophotometric Quantification Of Paracetamol And Tramadol Hydrochloride By Chemometric Calibration Methods, Faysal Seli̇moğlu, Nermi̇n Pinarcik

Turkish Journal of Chemistry

The results of UV spectrophotometric analysis were analysed using partial least squares (PLS) and principal component regression (PCR) techniques to allow simultaneous evaluation of tramadol hydrochloride (TRA) and p-acetaminophen (PAR) in tablets. A calibration set of 16 mixtures, each containing PAR and TRA in various amounts, was created using a 24-full fractional design. The absorbance data set for the calibration set were obtained between 215?280 nm (?? = 0.1 nm). Subsequently, the concentration and absorbance sets were used to generate PCR and PLS calibrations. The ratio spectra- first derivative method was devised as a solution to the same problem to …


Investigation Of Boron Adsorption By Graphene Oxide: Equilibrium, Kinetic, And Thermodynamic Studies, Mehmet Fati̇h Önen, Nalan Erdöl Aydin, Osman Eksi̇k, Peli̇n Demi̇rci̇vi̇, Gülhayat Saygili Jan 2023

Investigation Of Boron Adsorption By Graphene Oxide: Equilibrium, Kinetic, And Thermodynamic Studies, Mehmet Fati̇h Önen, Nalan Erdöl Aydin, Osman Eksi̇k, Peli̇n Demi̇rci̇vi̇, Gülhayat Saygili

Turkish Journal of Chemistry

Graphene oxide, which has a great application in industry, is one of the promising carbonous materials. Modified Hummers method was applied to synthesize graphene oxide. Characterization techniques showed that pure graphene oxide was successfully obtained. Its adsorptive properties were investigated by boron adsorption. The results were demonstrated that boron adsorption on graphene oxide was a pH-dependent process and maximum adsorption was achieved at pH 6 (0.98 mg g?1). Langmuir adsorption capacity was calculated as 3.92 mg g?1 with R2 = 0.99. The kinetic data brought to light that pseudosecond-order kinetic model was well described the experimental data (R2 = 0.99), …


Novel Technique In Production Of Pb (Ii)- Imprinted Polymers, Ehab Mohammed, Mostafa M. Elsheikh, Adham A. El-Zomrawy, Farag A. Ahmed Jan 2023

Novel Technique In Production Of Pb (Ii)- Imprinted Polymers, Ehab Mohammed, Mostafa M. Elsheikh, Adham A. El-Zomrawy, Farag A. Ahmed

Al-Azhar Bulletin of Science

Ion imprinting techniques were used to produce ion imprinted polymer (IIP) particles for the selective removal of Pb2+ from aqueous environments. As the Templating monomers, acrylic acid, acrylic amine ligand, and Methylene Bisacrylamide crosslinker were chosen. The imprinted polymer was prepared by free radical polymerization. By leaching with 0.1 M HCl, the (Pb2+) ion was removed from the template. The polymer particles were characterized by IR spectroscopy, Thermal analysis and potentiometric analysis. The produced polymer was mechanically crushed into fine particles, assembled into a sensor probe, and linked to a bare HB graphite pencil electrode (GPE). The sensor has a …


Enhanced Adsorption Of Anionic Dyes Using Sr-Doped Zno Nanoparticles: Nonlinear Kinetics And Isotherm Studies, Mostafa H. Mohamed, Taha M. Elmorsi, H. M. Abdelbary Jan 2023

Enhanced Adsorption Of Anionic Dyes Using Sr-Doped Zno Nanoparticles: Nonlinear Kinetics And Isotherm Studies, Mostafa H. Mohamed, Taha M. Elmorsi, H. M. Abdelbary

Al-Azhar Bulletin of Science

Using a co-precipitation process, sr-doped ZnO was prepared and demonstrated to be effective in the removal of anionic congo red dye, since its surface positive charge was increased to 17.3 mV. To investigate the surface morphology and physicochemical characteristics of Sr-doped ZnO, FTIR spectroscopy, scanning electron microscopy (SEM), elemental analysis, and point of zero charges (pHPZC) were employed. We conducted batch adsorption experiments to investigate the effects of contact time (180 minutes), pH (3.5–11), adsorbent dosage (0.5–3.0 g L−1), and temperature (288–328 K). The kinetic study was modeled using several equations, including pseudo-firstorder (PFO), pseudo-second-order (PSO), Elovich, and intra-particle diffusion …