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Turkish Journal of Electrical Engineering and Computer Sciences
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Optimal Location For Shunt Connected Facts Devices In A Series Compensated Long Transmission Line, P.R. Sharma, Ashok Kumar, Narender Kumar
Optimal Location For Shunt Connected Facts Devices In A Series Compensated Long Transmission Line, P.R. Sharma, Ashok Kumar, Narender Kumar
Turkish Journal of Electrical Engineering and Computer Sciences
Shunt FACTS devices are used for controlling transmission voltage, power flow, reducing reactive losses, and damping of power system oscillations for high power transfer levels. In this paper the optimal location of a shunt FACT device is investigated for an actual line model of a transmission line having series compensation at the center. Effect of change in degree of series compensation on the optimal location of the shunt FACTS device to get the highest possible benefit is studied. It is found that the optimal location of the shunt FACTS device varies with the change in the level of series compensation …
A New Relaying Algorithm To Detect Loss Of Excitation Of Synchronous Generators, Ömer Usta, M. H. Musa, M. Bayrak, M.A. Redfern
A New Relaying Algorithm To Detect Loss Of Excitation Of Synchronous Generators, Ömer Usta, M. H. Musa, M. Bayrak, M.A. Redfern
Turkish Journal of Electrical Engineering and Computer Sciences
A new digital relaying algorithm is introduced for the protection of synchronous generators against loss of excitation conditions. The new algorithm is based on measuring of the 3-phase reactive power output of the machines, and monitors the direction and magnitude of leading reactive power at the generator terminal. The protection algorithm is designed such that it can provide reliable protection against loss of field conditions and remains stable during recoverable power system swing conditions. While the new relay produces a trip signal for partial loss of field conditions causing the machine to lose its stability, it remains stable for the …
A Sensitive Ann Based Differential Relay For Transformer Protection With Security Against Ct Saturation And Tap Changer Operation, Hassan Khorashadi Zadeh, Zuyi Li
A Sensitive Ann Based Differential Relay For Transformer Protection With Security Against Ct Saturation And Tap Changer Operation, Hassan Khorashadi Zadeh, Zuyi Li
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents an artificial neural network (ANN) based scheme for fault identification in power transformer protection. The proposed scheme is featured by the application of ANN to identifying system patterns, the unique choice of harmonics of positive sequence differential currents as ANN inputs, the effective handling of current transformer (CT) saturation with an ANN based approach, and the consideration of tap changer position for correcting secondary CT current. Performance of the proposed scheme is studied for a wide variety of operating conditions using data generated from simulation. The results indicate that the proposed scheme provides a fast and sensitive …
Study Of The Warranty Cost Model For Software Reliability With An Imperfect Debugging Phenomenon, D.R. Prince Williams
Study Of The Warranty Cost Model For Software Reliability With An Imperfect Debugging Phenomenon, D.R. Prince Williams
Turkish Journal of Electrical Engineering and Computer Sciences
Software reliability is one of the most important characteristics of software quality. Its measurement and management technologies employed during the software life-cycle are essential for producing and maintaining quality/reliable software systems. Herein, we discuss a modified approach to calculating the delivery cost of a software product, when warranty is to be provided, with an imperfect debugging phenomenon. Unlike existing cost models, here the strategy was to consider maintenance support given to the customer with an imperfect debugging phenomenon. The optimal release time can be calculated for various reliability levels by minimizing the cost. The delivery cost, reliability of the software …
Chemoenzymatic Synthesis Of 2-Bromo-6-Hydroxy-3-Methoxy-2-Cyclohexen-1-One, Emi̇ne Özgül Karaaslan, Yasemi̇n Toka
Chemoenzymatic Synthesis Of 2-Bromo-6-Hydroxy-3-Methoxy-2-Cyclohexen-1-One, Emi̇ne Özgül Karaaslan, Yasemi̇n Toka
Turkish Journal of Chemistry
A chemoenzymatic synthesis of 2-bromo-6-hydroxy-3-methoxy-2- cyclohexen-1-one starting from cyclohexane-1,3-dione is reported. Manganese(III) acetate-mediated acetoxylation followed by the enzyme-mediated hydrolysis of \alpha'-acetoxy enone affords hydroxy-enone 5 and acetoxy enone 4 with high enantiomeric excesses in good yields.
Iridoid Glucosides From Lamium Garganicum Subsp. Laevigatum, Tayfun Ersöz, Duygu Kaya, Funda Nuray Yalçin, Cavi̇t Kazaz, Erhan Palaska, Charlott H. Gotfredsen, Soren R. Jensen, İhsan Çaliş
Iridoid Glucosides From Lamium Garganicum Subsp. Laevigatum, Tayfun Ersöz, Duygu Kaya, Funda Nuray Yalçin, Cavi̇t Kazaz, Erhan Palaska, Charlott H. Gotfredsen, Soren R. Jensen, İhsan Çaliş
Turkish Journal of Chemistry
Phytochemical investigations on the above-ground parts of Lamium garganicum subsp. laevigatum resulted in the isolation of 7 iridoid glucosides: shanzhiside methyl ester (1), barlerin (8-O-acetylshanzhiside methyl ester) (2), 6-O-syringyl-8-O-acetylshanzhiside methyl ester (3), 6\beta-hydroxyipolamiide (4), lamalbide (5), dehydropenstemoside (6), and sesamoside (7). The structure of the iridoids was elucidated by spectroscopic (UV, IR, 1D- and 2D-NMR, and ESI-MS) evidence.
Synthesis Of Nitrogen-Containing Heterocycles From The Reaction Of Amidrazones With \Alpha-Haloesters, Hany M. Dalloul, Peter H. Boyle
Synthesis Of Nitrogen-Containing Heterocycles From The Reaction Of Amidrazones With \Alpha-Haloesters, Hany M. Dalloul, Peter H. Boyle
Turkish Journal of Chemistry
The reaction of amidrazones 1 with \alpha-haloesters 2 formed 1,3,5-substituted 4,5-dihydro-1,2,4-triazin-6-ones (4a-z) rather than 1,2,4-triazin-5-one derivatives (5a-z). The microanalysis and spectral data of the synthesized compounds are in full agreement with their molecular structure.
Basic Al_2o_3 As A Recyclable Reagent For The Protection Of Carbonyl Groups With Phenylhydrazine Derivatives And Semicarbazides, Khodabakhsh Niknam, Ali Reza Kiasat, Bahador Karami, Nima Heydari
Basic Al_2o_3 As A Recyclable Reagent For The Protection Of Carbonyl Groups With Phenylhydrazine Derivatives And Semicarbazides, Khodabakhsh Niknam, Ali Reza Kiasat, Bahador Karami, Nima Heydari
Turkish Journal of Chemistry
Basic alumina is employed as an inorganic basic solid catalyst for the clean and less hazardous protection of carbonyl compounds, such as phenylhydrazones, 2,4-dinitrophenylhydrazones, semicarbazones, and thiosemicarbazones, under solvent-free conditions. The reactions proceed smoothly and require a short reaction time with good to excellent yields, and the alumina used can be recycled.
Synthesis And Characterization Of Polyimides Prepared From Optically Active (R,R) And (S,S)-1,3-Bis(P-N,N´-Dimethylaminobenzyl)-Perhydrobenzimidazol-2-Thion, Murat Yi̇ği̇t, Turgay Seçki̇n, Süleyman Köytepe, Engi̇n Çeti̇nkaya
Synthesis And Characterization Of Polyimides Prepared From Optically Active (R,R) And (S,S)-1,3-Bis(P-N,N´-Dimethylaminobenzyl)-Perhydrobenzimidazol-2-Thion, Murat Yi̇ği̇t, Turgay Seçki̇n, Süleyman Köytepe, Engi̇n Çeti̇nkaya
Turkish Journal of Chemistry
This paper presents the synthesis and characterization of polyimides containing a chiral (R,R) or (S,S) 1,3-bis(p-N,N´-dimethylaminobenzyl)-perhydrobenzimidazol-2-thion unit in the backbone. The reactions occur between equimolar amounts of a dianhydride and an aromatic dimethylamine in the presence of the solvent N-methyl-2-pyrollidone (NMP). In this work, the chiral monomer RR and SS -1,3-bis(p-N,N´-dimethylaminobenzyl)-perhydrobenzimidazol- 2-thion were used as diamines. The polyimides obtained were characterized by thermogravimetry (TGA), differential thermal analysis (DTA), differential scanning calorimeter (DSC), infrared spectroscopy (FT-IR), and gel permeation chromatography (GPC). It was found that the composition of the polymer had a significant effect upon the thermal behavior of the material.
Synthesis Of 2-Acylamino, 2-Aroylamino And Ethoxycarbonyl Imino-1,3,4-Thiadiazoles As Antitumor Agents, Kemal Sancak, Yasemi̇n Ünver, Mustafa Er
Synthesis Of 2-Acylamino, 2-Aroylamino And Ethoxycarbonyl Imino-1,3,4-Thiadiazoles As Antitumor Agents, Kemal Sancak, Yasemi̇n Ünver, Mustafa Er
Turkish Journal of Chemistry
2-Amino-1,3,4-thiadiazoles compounds (2a-e) were obtained from the reaction of thiosemi carbazide with 2-cyanomethoxyphenoxyacetonitriles (1). Mono acylamino, mono aroylamino and diethoxycarbonyl imino-1,3,4-thiadiazole compounds (3a-e, 4a-e, 5a-c) were synthesized via the reaction of 2-amino-1,3,4-thiadiazole compounds (2a-e) with acetyl chloride or acetic anhydride, benzoyl chloride or benzoic anhydride and ethyl chloroformate, respectively. The in vitro antitumor activities of some selected compounds were screened and compounds 2a, 2b, 2c, 3a, 3b, 3c, 5a, 5b and 5c were found to be active.
Synthesis And Spectroscopic Characterization Of New [Cu(^{Tbu}Salpphen)]_2, [Mocl_2(Salpphen)]_2 Complexes And Sn_2cl_8(^{Tbu}Salpphen).2hnet_3 Adduct, Peli̇n Sözen, Yurdanur Akgül, Funda Demi̇rhan
Synthesis And Spectroscopic Characterization Of New [Cu(^{Tbu}Salpphen)]_2, [Mocl_2(Salpphen)]_2 Complexes And Sn_2cl_8(^{Tbu}Salpphen).2hnet_3 Adduct, Peli̇n Sözen, Yurdanur Akgül, Funda Demi̇rhan
Turkish Journal of Chemistry
Tetradentate Schiff base ligands, which were derived from the condensation of phenylenediamine with salicylaldehyde [salpphenH_2: N, N'-p-phenylene-bis(salicyclideneimine)] or 3,5-di-tert-butyl-2-hydroxyben- zaldehyde [^{tBu}salpphenH_2: N, N'-p-phenylene-bis(3,5-di-tert-butylsalicylidene)] and their complexes of Cu(II), Mo(IV) and adduct of Sn(IV) were synthesized and characterized by ^1H-NMR, ^{13}C-NMR, and IR spectroscopic methods, mp, elemental analysis, and magnetic susceptibility. According to these data probable structures were assigned to these complexes and adduct. These are of the formula [Cu(^{tBu}salpphen)]_2 and [MoCl_2(salpphen)]_2, and Sn_2Cl_8(^{tBu}salpphen).2HNEt_3. [Cu(^{tBu}salpphen)]_2 was prepared by the reaction of the metal salt with the ^{tBu}salpphenH_2 Schiff base ligand in EtOH. [MoCl_2(salpphen)]_2 was synthesized by reactions of [MoCl_4(CH_3CN)_2] with the …
On-Line Preconcentration And Speciation Of Chromium By An 8-Hydroxyquinoline Microcolumn Immobilized On Surfactant-Coated Alumina And Flow Injection Atomic Absorption Spectrometry, Seyyed Hamid Ahmadi, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, Masoumeh Taei
On-Line Preconcentration And Speciation Of Chromium By An 8-Hydroxyquinoline Microcolumn Immobilized On Surfactant-Coated Alumina And Flow Injection Atomic Absorption Spectrometry, Seyyed Hamid Ahmadi, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, Masoumeh Taei
Turkish Journal of Chemistry
An on-line technique for the determination of chromium species with atomic absorption spectrometry is described. The method is based on separation and preconcentration of Cr(III) on a microcolumn of immobilized 8-hydroxyquinoline on surfactant-coated alumina. The adsorbed analyte is then eluted with 400 \mu L of 20% ethanolic solution of 1.5 mol L^{-1} hydrochloric acid and is transported to a flame atomic absorption spectrometer for quantification. The effects of pH, sample and eluent flow rate, sorption capacity, and the presence of various cations and anions on the sorption of Cr(III) were investigated. The sorption was quantitative in the pH 6-8 range, …
Synthesis And Physico-Chemical And Spectroscopic Investigations Of Sodium Dihydrobis(1,2,3-Benzotriazolyl)Borate Ligand And Its Transition Metal Complexes, . Lutfullah, Ahmad Umar, Mohammed Muzibur Rahman, Mohammad Mansoob Khan, Yoon Bong Hahn
Synthesis And Physico-Chemical And Spectroscopic Investigations Of Sodium Dihydrobis(1,2,3-Benzotriazolyl)Borate Ligand And Its Transition Metal Complexes, . Lutfullah, Ahmad Umar, Mohammed Muzibur Rahman, Mohammad Mansoob Khan, Yoon Bong Hahn
Turkish Journal of Chemistry
The title ligand, sodium dihydrobis(1,2,3-benzotriazolyl)borate, Na[H_2B(BTz)_2], was synthesized by refluxing 1 mole of sodium borohydride with 2 moles of 1,2,3- benzotriazole in toluene. The ligand shows ample reactivity towards Cr(III), Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) metal ions and forms stable complexes. The ligand and its metal complexes were characterized by physico-chemical and spectroscopic techniques. All the complexes of divalent metal ions are tetrahedral except for Cu(II), which has been proposed to have a square-planar geometry. The complexes of Cr(III) and Fe(III) appear to have an octahedral geometry. The magnitude of molar conductance of 10^{-3} M …
Investigation Of The Voltammetric Characteristics Of Poly(1,4-Diaminobenzene) Film As A Dopamine-Selective Polymer Electrode, Gamze Erdoğdu, A. Ersi̇n Karagözler
Investigation Of The Voltammetric Characteristics Of Poly(1,4-Diaminobenzene) Film As A Dopamine-Selective Polymer Electrode, Gamze Erdoğdu, A. Ersi̇n Karagözler
Turkish Journal of Chemistry
Electrochemical polymerization of 1,4-diaminobenzene in the KCl aqueous electrolyte at a potential of 0.600 V versus Ag/AgCl produces adherent poly(1,4-diaminobenzene) film on a gold electrode. The electrochemical behavior of dopamine and ascorbic acid at the polymer electrode prepared in this manner was examined by cyclic and differential pulse voltammetry. Voltammetry studies showed that polymeric film with a thickness corresponding to a 7-mC charge exhibited selective permeation for dopamine while retaining ascorbic acid. All the polymerization parameters affecting the permselective characteristics were systematically investigated and the optimum values were determined. The results showed that a polymeric membrane, owing to its permselective …
Investigation Of Some 1,3-Diols For The Requirements Of Solvent Extraction Of Boron: 2,2,6-Trimethyl-1,3 Heptanediol As A Potential Boron Extractant, Bi̇lsen Tural, Servet Tural, Hali̇l Hoşgören
Investigation Of Some 1,3-Diols For The Requirements Of Solvent Extraction Of Boron: 2,2,6-Trimethyl-1,3 Heptanediol As A Potential Boron Extractant, Bi̇lsen Tural, Servet Tural, Hali̇l Hoşgören
Turkish Journal of Chemistry
Eighteen 1,3-diols were synthesized and their structure and distribution ratio for the solvent extraction of boron were studied. Diols with a high distribution ratio (D_{B(OH)_3 > 10) were investigated for the requirements of solvent extraction of boron. Their extraction capacity, and solubility in aqueous phase and in organic diluents were investigated by comparison to 2-ethyl-1,3-hexanediol (EHD), which is widely used as a boron extractant. Among a series of 1,3 diols, 1-benzyl-2,2-dimethyl-1,3-propanediol (4a) and 2,2,6-trimethyl-1,3-heptanediol (3a) were found to have very low solubility in the aqueous phase compared to the others. IPD (3a) was found to have a high solubility in aliphatic …
Hydrothermal Synthesis, Characterization And Photocatalytic Activity Of Nanosized Tio_2 Based Catalysts For Rhodamine B Degradation, Funda Sayilkan, Meltem Asi̇ltürk, Şadi̇ye Şener, Sema Erdemoğlu, Murat Erdemoğlu, Hi̇kmet Sayilkan
Hydrothermal Synthesis, Characterization And Photocatalytic Activity Of Nanosized Tio_2 Based Catalysts For Rhodamine B Degradation, Funda Sayilkan, Meltem Asi̇ltürk, Şadi̇ye Şener, Sema Erdemoğlu, Murat Erdemoğlu, Hi̇kmet Sayilkan
Turkish Journal of Chemistry
Nanosize crystalline TiO_2 and SiO_2/TiO_2 mixed oxide particles as a photocatalyst for rhodamine B dye (RB) degradation in aqueous media were synthesized by a hydrothermal process at 200 °C. They were characterized using XRD, SEM, FT-IR, UV/VIS and BET analysis. The effects of silica content on the crystallinity and photocatalytic activity of TiO_2 were investigated. Photocatalytic activity of the nano-TiO_2 was compared with that of SiO_2/TiO_2 mixed oxides at the same conditions for degradation of RB, and mixed oxide catalysts showed more effective catalytic activity than the TiO_2. The results revealed that photodegradation of RB proceeds by pseudo-first-order reaction kinetics …
Voltammetric And Spectroscopic Studies Of Vanadium(V)-- Nicotinamide Interactions At Physiological Ph, Semi̇ha Çakir, Ender Bi̇çer
Voltammetric And Spectroscopic Studies Of Vanadium(V)-- Nicotinamide Interactions At Physiological Ph, Semi̇ha Çakir, Ender Bi̇çer
Turkish Journal of Chemistry
The interaction of nicotinamide (NA) with NH_4VO_3 at the physiological pH (pH 7.4) was studied by voltammetry and UV-Vis spectroscopy. The reduction of V(V) ions complexed with NA in phosphate buffer (pH 7.4) was observed as a well-defined reversible reduction peak at --0.35 V. The stoichiometric (metal:ligand) ratio of the complex of V(V) with NA was determined as 1:2 by the mole ratio method.
Template-Free Synthesis Of Zsm-5 Type Zeolite Layers On Porous Alumina Disks, Hali̇l Kalipçilar, Ali̇ Çulfaz
Template-Free Synthesis Of Zsm-5 Type Zeolite Layers On Porous Alumina Disks, Hali̇l Kalipçilar, Ali̇ Çulfaz
Turkish Journal of Chemistry
ZSM-5 crystals were synthesized from template-free batches on macroporous \alpha-alumina disks. The SiO_2/Al_2O_3 ratio of the synthesis gel influenced the crystal morphology, surface coverage and intergrowth among the crystals. Prismatic ZSM-5 crystals covered the disk surface when the SiO_2/Al_2O_3 ratio of the batch was higher than 100, whereas spherical polycrystalline particles of ZSM-5 were obtained from batches with a SiO_2/Al_2O_3 ratio of 80. Mordenite type zeolite was formed on the disk surface due to the incorporation of alumina dissolved from the disk when the time of crystallization was extended. The effects of silica source and seeding of the support surface …
An Electrochemical Dna Biosensor For The Detection Of Dna Damage Caused By Radioactive Iodine And Technetium, Pinar Kara, Kağan Dağdevi̇ren, Mehmet Özsöz
An Electrochemical Dna Biosensor For The Detection Of Dna Damage Caused By Radioactive Iodine And Technetium, Pinar Kara, Kağan Dağdevi̇ren, Mehmet Özsöz
Turkish Journal of Chemistry
A DNA damage process by radioactive iodine (I-131) and technetium (Tc-99m) is described. The procedure relies on a label-free electrochemical DNA biosensor. Fish sperm double stranded DNA was immobilized onto a carbon paste electrode (CPE) by electro deposition and the changes to the guanine oxidation signal were observed upon exposure to radioactive I-131 and Tc-99m by differential pulse voltammetry (DPV). The changes to the signal of guanine after exposure to therapeutic doses of Tc-99m and I-131 showed conformational changes in DNA molecules.
A New Approach To Furan-Containing Macrolactones, Christoph Schmidt, Ruth Messmer, Franz Bracher, Jurgen Krauss
A New Approach To Furan-Containing Macrolactones, Christoph Schmidt, Ruth Messmer, Franz Bracher, Jurgen Krauss
Turkish Journal of Chemistry
Furan and tetrahydrofuran heterocycles are part of many natural products, like the Galerucella pheromone, furano epothilones, bipinnatin, and amphidinolides. This paper describes a short and efficient synthetic approach to furan-containing macrolactones in 4 steps, including as key steps a Sonogashira reaction and an olefin metathesis. The resulting compounds were tested at the National Cancer Institute for their cytotoxicity, but did not exhibit significant cytotoxicity in the human tumour cell line screen.
Preparation And Properties Of Triethoxyvinylsilane-Modified Styrene - Butyl Acrylate Emulsion Copolymers, Hamit Javaherian Naghash, Akram Karimzadeh, Ahmad Reza Momeni, Ahmad Reza Massah, Hamid Alian
Preparation And Properties Of Triethoxyvinylsilane-Modified Styrene - Butyl Acrylate Emulsion Copolymers, Hamit Javaherian Naghash, Akram Karimzadeh, Ahmad Reza Momeni, Ahmad Reza Massah, Hamid Alian
Turkish Journal of Chemistry
The copolymers of triethoxyvinylsilane (TEVS) with styrene (St), butyl acrylate (BA), and methacrylic acid (MAA) were prepared by emulsion polymerization. The copolymerization was carried out by using auxiliary agents at 90 °C in the presence of potassium peroxodisulfate (KPS) as the initiator. Nonylphenol ethylene oxide -- 40 units (NP-40) and sodium lauryl sulfoacetate (SLSA) were used as nonionic and anionic emulsifiers, respectively. The resulting copolymers were characterized by Fourier transform infrared spectroscopy (FTIR). Thermal properties of the copolymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of copolymers was also investigated by optical microscopy (OM) …
Mono-, Di- And Trinuclear Copper(Ii) Complexes Of A Schiff Base Ligand, 2-{(E)-[(6-{[(1e)-(2-Hydroxyphenyl)Methylene]Amino}Pyridin-2-Yl)Imino]-Methyl}Phenol, Nevi̇n Karaböcek, Serdar Karaböcek, Fatma Kormali
Mono-, Di- And Trinuclear Copper(Ii) Complexes Of A Schiff Base Ligand, 2-{(E)-[(6-{[(1e)-(2-Hydroxyphenyl)Methylene]Amino}Pyridin-2-Yl)Imino]-Methyl}Phenol, Nevi̇n Karaböcek, Serdar Karaböcek, Fatma Kormali
Turkish Journal of Chemistry
A Schiff base ligand, 2-{(E)-[(6-[(1E)-(2-hydroxyphenyl) methylene]amino}-pyridin-2-yl)imino]-methyl} phenol (H_2PySAL), was prepared by condensation of 2,6-diaminopyridine and salicylaldehide in EtOH. The Schiff base ligand was checked by elemental analyses, ^1H-NMR, ^{13}C-NMR, IR, UV/Vis, and mass spectral studies. Three new mono-, di-, and trinuclear copper(II) complexes of the Schiff base ligand, formula [Cu(H_2PySAL)]Cl_2, [Cu_2(PySAL) (Phen)]Cl_2, [Cu_3(PySAL)_2]Cl_2, were prepared and characterized by elemental analyses, magnetic moment, and IR, Uv/Vis, and mass spectral studies. The spectroscopic data of the complexes indicate that the copper(II) ions are coordinated by the oxygen atoms and nitrogen atoms (C=N) of the ligand. In the dinuclear complex, in which the …
Fft-Adsorptive Voltammetric Technique For Pico-Level Determination Of Tetracycline In Capsules At An Au Microelectrode In Flowing Solutions, Parviz Norouzi, Mohammad Reza Ganjali, Parandis Daneshgar
Fft-Adsorptive Voltammetric Technique For Pico-Level Determination Of Tetracycline In Capsules At An Au Microelectrode In Flowing Solutions, Parviz Norouzi, Mohammad Reza Ganjali, Parandis Daneshgar
Turkish Journal of Chemistry
This study illustrates a novel method for fast monitoring of tetracycline in flow-injection systems. The fast Fourier transformation, along with continuous cyclic voltammetry (FFTCV) at a gold microelectrode in a flowing solution system, was used for the determination of tetracycline in its pharmaceutical formulation. The benefit of the developed technique is that it is simple, precise, accurate, time-saving, and economical compared to all of the previously reported methods. The effects of various parameters on the sensitivity of the method were investigated. Three considerable advantages are demonstrated by this method, which other methods do not possess. Firstly, there is no requirement …
Speciation Of Manganese Using A Pneumatic Flow Injection Analysis-Tandem Spectrometer System, Meissam Noroozifar, Mozhgan Khorasani-Motlagh, Reza Akbari
Speciation Of Manganese Using A Pneumatic Flow Injection Analysis-Tandem Spectrometer System, Meissam Noroozifar, Mozhgan Khorasani-Motlagh, Reza Akbari
Turkish Journal of Chemistry
A pneumatic flow injection-tandem spectrometer system, without a delivery pump, was used for the speciation of manganese (Mn). In this system the suction force of the pneumatic nebulizer of a flame atomic absorption spectrometer (FAAS) was used for solution delivery through the manifold. Mn(VII) and total Mn (Mn(VII) and Mn(II)) concentrations were determined using a UV-Vis spectrometer and FAAS, respectively. The Mn(II) concentration was determined by the difference between the two. The calibration curves were linear up to 15.00 mg L^{-1} for Mn(VII) and total Mn, with a detection limit of 0.08 mg L^{-1} and 0.05 mg L^{-1} for Mn(VII) …
Synthesis Of Some New 1-Acylthiosemicarbazides And 1,2,4-Triazol-5-Thiones, And Their Analgesic And Anti-Inflammatory Activities, Yasemi̇n Dündar, Bi̇lge Çakir, Esra Küpeli̇, M. Fethi̇ Şahi̇n, Ni̇ngur Noyanalpan
Synthesis Of Some New 1-Acylthiosemicarbazides And 1,2,4-Triazol-5-Thiones, And Their Analgesic And Anti-Inflammatory Activities, Yasemi̇n Dündar, Bi̇lge Çakir, Esra Küpeli̇, M. Fethi̇ Şahi̇n, Ni̇ngur Noyanalpan
Turkish Journal of Chemistry
We synthesized new 1-[3-(2-oxobenzothiazolin-3-yl)propanoyl]-4- substituted-thiosemicarbazides and their corresponding cyclized 3-[2-(2-oxobenzothiazoline-3-yl)ethyl]-4-substituted-1,2,4-triazol-5-thione ana-logs in which position 4 of the triazole ring was substituted by cyclohexyl, methyl, allyl, phenyl, p-methylphenyl, p-methoxyphenyl, p-chlorophenyl, p-nitrophenyl, benzyl, and phenylethyl to screen their analgesic and anti-inflammatory activities as well as gastric ulceration potential in test animals. None of the compounds, except 5a, 5e, and 5h, caused gastric lesions or bleeding. Compound 5g was found to have higher analgesic and anti-inflammatory activity among the synthesized compounds.
Synthesis Of Some Novel 3,5-Diaryl-1,2,4-Triazole Derivatives And Investigation Of Their Antimicrobial Activities, Mevlut Serdar, Nurhan Gümrükçüoğlu, Şengül Alpay Karaoğlu, Nesli̇han Demi̇rbaş
Synthesis Of Some Novel 3,5-Diaryl-1,2,4-Triazole Derivatives And Investigation Of Their Antimicrobial Activities, Mevlut Serdar, Nurhan Gümrükçüoğlu, Şengül Alpay Karaoğlu, Nesli̇han Demi̇rbaş
Turkish Journal of Chemistry
A series of acylhydrazones (2a-d) was synthesized from the reactions of iminoester hydrochlorides (1a-e) with acyl hydrazines. 2,5-Dialkyl 1,3,4-oxadiazoles (3a-d) were obtained in the same reaction media. The treatment of acylhydrazones with hydrazine hydrate afforded 4-amino-3,5-dialkyl-1,2,4-triazoles (4a-c). The acetylation of 4-amino-3-(4-hydroxyphenyl)-5-phenyl-4H-1,2,4-triazole (4a) produced 4-amino-5-(4-acetoxyphenyl)-3-phenyl-4H-1,2,4-triazole (9), while the acetylation of 4-amino-3-(4-tolyl)-5-phenyl-4H-1,2,4-triazole (4b) gave 4-acetylamino-3-phenyl-5-(4-tolyl)-4H-1,2,4-triazole (10). The treatment of compound 4b with various aromatic aldehydes or acetophenone and 4-nitroacetophenone resulted in the formation of 4-arylidenamino-3,5-dialkyl-4H-1,2,4-triazoles (5a-e and 7a,b). Sodium borohydride reduction of 4-arylidenamino derivatives of 1,2,4-triazoles afforded 4-alkylamino-3,5-dialkyl-4H-1,2,4-triazoles (6a-e and 8a,b). All newly synthesized compounds were screened for their antimicrobial and antifungal …
Studies On The Anion Recognition Properties Of Synthesized Receptors Iii: A Novel Thiourea-Based Receptor Constructed By Benzo-15-Crown-5 For Sensing Anions In A Strong Polar Solvent, You-Ming Zhang, Hai-Xian Ren, Yan-Qing Zhou, Rong Luo, Wei-Xia Xu, Tai-Bao Wei
Studies On The Anion Recognition Properties Of Synthesized Receptors Iii: A Novel Thiourea-Based Receptor Constructed By Benzo-15-Crown-5 For Sensing Anions In A Strong Polar Solvent, You-Ming Zhang, Hai-Xian Ren, Yan-Qing Zhou, Rong Luo, Wei-Xia Xu, Tai-Bao Wei
Turkish Journal of Chemistry
A new series of receptors were designed and synthesized, and their interactions with anions, such as F^-, Cl^-, Br^-, I^-, CH_3COO^-, HSO_4^-, and NO_3^-, in DMSO solvent were investigated using UV-Vis absorption spectroscopy. The results showed that hydrogen-bonding complexes were formed between the receptors and the tested anions, such as CH_3COO^- and F^-. It was also found that the selectivity of the receptors for anions could be efficiently tuned by changing the place of the substituent group at the N-phenyl moiety. The recognition mechanism and binding mode are discussed. These findings were expected to be of significance for designing and …
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nurhan Gümrükçüoğlu, Mevlut Serdar, Eli̇f Çeli̇k, Ali̇ Sevi̇m, Nesli̇han Demi̇rbaş
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nurhan Gümrükçüoğlu, Mevlut Serdar, Eli̇f Çeli̇k, Ali̇ Sevi̇m, Nesli̇han Demi̇rbaş
Turkish Journal of Chemistry
A series of acylhydrazones (2a-f) were synthesized by the condensation of iminoester hydrochlorides (1a-f) with acyl hydrazines. 2,5-Dialkyl 1,3,4-oxadiazoles (3a,c,e) were obtained in the same reaction media. The treatment of acylhydrazones with hydrazine hydrate afforded 4-amino-3,5-dialkyl-1,2,4-triazoles (4a-c). The acetylation of 4-amino-3,5-dialkyl-1,2,4-triazoles produced N-[3,5-dialkyl-4H-1,2,4-triazol-4-yl] acetamides (5-7). The treatment of compounds 4a and 4c with various aromatic aldehydes resulted in the formation of 4-arylidenamino-3,5-dialkyl-1,2,4-triazoles (8a,d, e, and 10a-e). Sodium borohydride reduction of 4-arylidenamino derivatives afforded 4-alkylamino-3,5-dialkyl-1,2,4-triazoles (9a,d, e, and 11a-e). Compounds 4b, 4c, 7, 8d, and 11c showed good antifungal activity only against yeast-like fungi, while compounds 3e, 6, 8e, and 9e …