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Full-Text Articles in Physical Sciences and Mathematics

Efficient C--C Cross-Coupling Reactions By (Isatin)-Schiff Base Functionalized Magnetic Nanoparticle-Supported Cu(Ii) Acetate As A Magnetically Recoverable Catalyst, Seyedeh Simin Miri, Mehdi Khoobi, Fatemeh Ashouri, Farnaz Jafarpour, Parviz Rashidi Ranjbar, Abbas Shafiee Jan 2015

Efficient C--C Cross-Coupling Reactions By (Isatin)-Schiff Base Functionalized Magnetic Nanoparticle-Supported Cu(Ii) Acetate As A Magnetically Recoverable Catalyst, Seyedeh Simin Miri, Mehdi Khoobi, Fatemeh Ashouri, Farnaz Jafarpour, Parviz Rashidi Ranjbar, Abbas Shafiee

Turkish Journal of Chemistry

Copper catalysts were simply fabricated through surface modification of superparamagnetic iron nanoparticles with indoline-2,3-dione(isatin)-Schiff-base and interaction with Cu from low-cost commercially available starting materials. Catalysts were characterized using atomic absorption spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, vibrating sample magnetometry, UV/Vis spectroscopy, scanning electron microscopy, and transmission electron microscopy. These catalysts showed high efficiency for phosphine-free Mizoroki--Heck and Suzuki--Miyaura cross-coupling reactions with good diversity and generality. The catalysts could be easily recovered and reused several times without a significant loss in their catalytic activity and stability.


New Pd(Ii) And Pt(Ii)-Diaminophosphine Complexes Bearing Cyclohexyl Or Isopropyl Moiety: Use Of Pd(Ii) Complexes As Precatalyst In Mizoroki--Heck And Suzuki--Miyaura Cross-Coupling Reactions, Murat Aydemi̇r, Feyyaz Durap, Akin Baysal Jan 2015

New Pd(Ii) And Pt(Ii)-Diaminophosphine Complexes Bearing Cyclohexyl Or Isopropyl Moiety: Use Of Pd(Ii) Complexes As Precatalyst In Mizoroki--Heck And Suzuki--Miyaura Cross-Coupling Reactions, Murat Aydemi̇r, Feyyaz Durap, Akin Baysal

Turkish Journal of Chemistry

Two new diaminophosphine ligands, $N$,$N$'-bis(dicyclohexylphosphino)-2-(aminomethyl)aniline (1) and $N$,$N$'-bis(diisopropylphosphino)-2-(aminomethyl)aniline (2) were synthesized by the reaction of 2-(aminomethyl)aniline with two equivalents of Cy$_{2}$PCl or (iPr)$_{2}$PCl, respectively. The reactions of 1 and 2 with MCl$_{2}$(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield complexes [cis-Pd(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 3, iPr 4) and [cis-Pt(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 5, iPr 6), respectively. The catalytic activity of the palladium complexes was investigated in the Suzuki-Miyaura cross-coupling reaction in the presence of Cs$_{2}$CO$_{3}$ as a base. The palladium complexes were also found to be highly active catalysts in the Mizoroki-Heck reaction.


Resorcinarene-Mono-Benzimidazolium Salts As Nhc Ligands For Suzuki--Miyaura Cross-Couplings Catalysts, Ümi̇t İşci̇, Muhi̇tti̇n Aygün, Resul Sevi̇ncek, Yunus Zorlu, Fabienne Dumoulin Jan 2015

Resorcinarene-Mono-Benzimidazolium Salts As Nhc Ligands For Suzuki--Miyaura Cross-Couplings Catalysts, Ümi̇t İşci̇, Muhi̇tti̇n Aygün, Resul Sevi̇ncek, Yunus Zorlu, Fabienne Dumoulin

Turkish Journal of Chemistry

Two mono-benzimidazolium salts of resorcinarene have been prepared and used as ligands in Suzuki--Miyaura cross-coupling reactions. They have been fully characterized by $^{1}$H and $^{13}$C NMR, MALDI, and FT-IR spectroscopic methods, and their structures were confirmed by X-ray diffraction analysis. These two new resorcinarene-based mono-benzimidazolium salts showed good catalytic activity for coupling reactions in DMF. The highest conversion was achieved for arylation of 4-bromotoluene using the resorcinarenyl mono-dimethylbenzimidazolium salt.


The Synthesis, Characterization, And Catalytic Properties Of ($\Kappa ^{2}-C,N)$-Palladacycles With N-Heterocyclic Carbene-Based Ancillary Ligands, Muhammet Emi̇n Günay, Gülcan Gençay Çoğaşlioğlu, Ruki̇ye Firinci Jan 2015

The Synthesis, Characterization, And Catalytic Properties Of ($\Kappa ^{2}-C,N)$-Palladacycles With N-Heterocyclic Carbene-Based Ancillary Ligands, Muhammet Emi̇n Günay, Gülcan Gençay Çoğaşlioğlu, Ruki̇ye Firinci

Turkish Journal of Chemistry

Novel five-membered ($\kappa ^{2}-C,N)$-palladacyclic complexes were prepared from the reaction of the corresponding acetate-bridged palladacycle dimer with N-heterocyclic carbene (NHC) ligands in high yields. Palladacyclic complexes (3) were fully characterized by elemental analysis and $^{1}$H and $^{13}$C NMR spectroscopy. Palladacyclic complexes were tested as catalyst for the C-C bond forming reaction. These complexes were found to be efficient catalysts for the Suzuki-Miyaura reaction of aryl bromides.


New La-Icp-Ms U-Pb Zircon Dating For Strandja Granitoids (Se Bulgaria): Evidence For Two-Stage Late Variscan Magmatism In The Internal Balkanides, Philip Machev, Valentin Ganev, Laslo Klain Jan 2015

New La-Icp-Ms U-Pb Zircon Dating For Strandja Granitoids (Se Bulgaria): Evidence For Two-Stage Late Variscan Magmatism In The Internal Balkanides, Philip Machev, Valentin Ganev, Laslo Klain

Turkish Journal of Earth Sciences

The Strandja Massif (Sakar-Strandja Zone) forms an important link between the Balkan Zone (external Balkanides) of Bulgaria, which is commonly correlated with the Variscan orogen in Central Europe, and the Western Pontides of Turkey. The Bulgarian part of the massif is composed of a metamorphic basement (various granite gneisses, paragneisses, and schists) traditionally interpreted as having Precambrian age, Triassic-Jurassic metasedimentary cover, and Upper Cretaceous volcanosedimentary sequences. The basement is intruded by large granitic plutons of Variscan age that are widespread mostly across Turkish territory. New LA-ICP-MS data support the suggestion of Variscan granitoid magmatism in the studied area but do …


Clay Mineralogy, Chemistry, And Diagenesis Of Late Devonian K-Bentonite Occurrences In Northwestern Turkey, Asuman Günal Türkmenoğlu, Ömer Bozkaya, Mehmet Cemal Göncüoğlu, Özge Ünlüce, İsmai̇l Ömer Yilmaz, Cengi̇z Okuyucu Jan 2015

Clay Mineralogy, Chemistry, And Diagenesis Of Late Devonian K-Bentonite Occurrences In Northwestern Turkey, Asuman Günal Türkmenoğlu, Ömer Bozkaya, Mehmet Cemal Göncüoğlu, Özge Ünlüce, İsmai̇l Ömer Yilmaz, Cengi̇z Okuyucu

Turkish Journal of Earth Sciences

Thin beds of tephra (K-bentonites) formed by the diagenesis of volcanic ash are exposed within the limestone-dolomitic limestone successions of the Yılanlı formation at Zonguldak and Bartın in northwestern Turkey. They were deposited on the Middle Devonian-Lower Carboniferous shallow carbonate platform of the Zonguldak terrane. In this study, K-bentonite samples collected from Gavurpınarı and Yılanlı Burnu limestone quarries are investigated in order to reveal their mineralogical and geochemical characteristics and diagenetic evolution. Illite is the major clay mineral in the studied K-bentonites. Additionally, kaolinite and mixed-layer illite-smectite are identified in some samples. The nonclay minerals calcite, dolomite, quartz, gypsum, feldspar, …


Nature And Physicochemical Conditions Of Crystallization In The South Dehgolan Intrusion, Nw Iran: Mineral-Chemical Evidence, Fatemeh Sarjoughian, Ali Kananian, David Richard Lentz, Jamshid Ahmadian Jan 2015

Nature And Physicochemical Conditions Of Crystallization In The South Dehgolan Intrusion, Nw Iran: Mineral-Chemical Evidence, Fatemeh Sarjoughian, Ali Kananian, David Richard Lentz, Jamshid Ahmadian

Turkish Journal of Earth Sciences

The South Dehgolan intrusion in the Sanandaj-Sirjan Zone ranges in composition from calc-alkalic monzogabbro to syenite to alkalic granite. This suite is composed mainly of variable proportions of quartz, K-feldspar, plagioclase, biotite, hornblende, and pyroxene. The plagioclase composition varies between albite to labradorite. The biotites are Mg- to Fe-rich in the monzogabbro to granite, respectively. The amphiboles are calcic and the composition varies from magnesiohornblende to actinolite. Clinopyroxene compositions fall in the diopside-augite field. The average calculated near-solidus crystallization temperatures are 774 °C, 655 °C, and 775 °C for the monzogabbro-monzodiorite, syenite, and granite, respectively. Calculated average pressures of emplacement …


Petrography And Geochemistry Of The Kamlial Formation, Southwestern Kohat Plateau, Pakistan: Implications For Paleoclimate Of The Western Himalayas, Kafayat Ullah, Mohammad Arif, Muhammad Tahir Shah Jan 2015

Petrography And Geochemistry Of The Kamlial Formation, Southwestern Kohat Plateau, Pakistan: Implications For Paleoclimate Of The Western Himalayas, Kafayat Ullah, Mohammad Arif, Muhammad Tahir Shah

Turkish Journal of Earth Sciences

The Middle to Late Miocene Kamlial Formation that largely consists of sandstone and interbedded clay/mudstone sequences is exposed in the southwestern part of the Kohat plateau, which constitutes the westernmost extension of the Himalayan Foreland Basin. Whereas the sandstone is gray to brownish gray, fine- to medium-grained, and mostly thick-bedded, the interbedded clay/mudstone sequence is brownish gray to maroon red and occurs as continuous beds as well as lenses. Some mudstone/clay beds are bioturbated and seem to be pedogenic surfaces. Results of geochemical investigation of fresh (unaltered) representative sandstone and mudstone samples from three different sections of the formation in …


Spatial-Temporal Analysis Of Seismicity Before The 2012 Varzeghan, Iran, Mw 6.5 Earthquake, Mohammad Talebi, Mehdi Zare, Rohollah Madahi Zadeh, Aref Bali-Lashak Jan 2015

Spatial-Temporal Analysis Of Seismicity Before The 2012 Varzeghan, Iran, Mw 6.5 Earthquake, Mohammad Talebi, Mehdi Zare, Rohollah Madahi Zadeh, Aref Bali-Lashak

Turkish Journal of Earth Sciences

In this work, the spatial and temporal variations of seismicity in northwestern Iran have been evaluated with a special focus on seismic precursors of the 11 August 2012 Mw 6.5 Varzeghan earthquake. The precursors are defined by the z-value test and the generalized fractal dimensions of earthquake epicenters. The investigation applies earthquakes that have occurred since 2006 in a region that includes the main shock and collected by the Iranian Seismological Center. In order to eliminate the effect of explosions in the processing, we removed the explosion from the used catalog by using the normalized ratio analysis of daytime to …


Lower Devonian Trace Fossils And Their Paleoenvironmental Significance From The Western Yangtze Plate, South China, Li-Jun Zhang, Zhao Zhao Jan 2015

Lower Devonian Trace Fossils And Their Paleoenvironmental Significance From The Western Yangtze Plate, South China, Li-Jun Zhang, Zhao Zhao

Turkish Journal of Earth Sciences

Abundant and diverse trace fossils occur in the littoral-neritic sediments recording an Early Devonian transgression in South China. The well-exposed Ganxi section is located in the Longmen Mountain 100 km northwest of Chendu, Sichuan. The Lower Devonian strata are dominated by sandstones, siltstones, muddy shales, limestones, bioclastic limestones, and muddy limestones. About thirteen ichnogenera were systematically described, including Arenicolites, ?Balanoglossites, Chondrites, Cylindrichnus, Diplocraterion, Planolites, Palaeophycus, Phycodes, Rhizocorallium, Rusophycus, Skolithos, Thalassinoides, and Zoophycos. Six trace fossil associations under different sedimentary environments have been recognized as follows: the Skolithos and Diplocraterion-Skolithos associations mainly consist of domichnia derived from a high-energy zone of …


Rare Earth Element Geochemistry Of The Upper Permian Limestone: The Kanigorgeh Mining District, Nw Iran, Ali Abedini, Ali Asghar Calagari Jan 2015

Rare Earth Element Geochemistry Of The Upper Permian Limestone: The Kanigorgeh Mining District, Nw Iran, Ali Abedini, Ali Asghar Calagari

Turkish Journal of Earth Sciences

The limestone of the Ruteh Formation of Upper Permian age in the Kanigorgeh district (northeast of Bukan, NW Iran) contains several layers and lenses of bauxitic ores. Mineralogical data show that this limestone consists of calcite and quartz as major and plagioclase, kaolinite, and hematite as minor mineral phases. Geochemical analyses reveal that the proportions of ?REEs (La-Lu) in this limestone vary from 35.28 to 160.78 ppm. The values of Eu and Ce anomalies (normalized to PAAS) of the limestone have ranges of 1.11-1.68 and 0.89-1.16, respectively. The high values of ?REEs; low values of Y/Ho; strong and positive correlations …


Petrography And Geochemistry Of Pharaonic Sandstone Monuments In Tall San Al Hagr, Al Sharqiya Governorate, Egypt: Implications For Provenance And Tectonic Setting, Samir Mahmoud Zaid, Oussama El Badry, Fatma Ramadan, Mahmoud Mohamed Jan 2015

Petrography And Geochemistry Of Pharaonic Sandstone Monuments In Tall San Al Hagr, Al Sharqiya Governorate, Egypt: Implications For Provenance And Tectonic Setting, Samir Mahmoud Zaid, Oussama El Badry, Fatma Ramadan, Mahmoud Mohamed

Turkish Journal of Earth Sciences

Petrographic and major and trace element compositions of Tanis sandstones from Tall San Al Hagr, Al Sharqiya Governorate, Egypt, have been investigated to determine their source, provenance, intensity of paleoweathering of the source rocks, and tectonic setting. Tanis sandstones are yellowish brown in color, siliceous, partly calcareous, and originated from sands deposited in fluvial channels. Texturally, Tanis sandstones are medium- to very coarse-grained, mature, and moderately sorted. Scarcity of feldspars indicates that the sandstone is extensively recycled from a distant source. Their average modal composition (Q99.75F0.03L0.22) classifies them as quartz arenites (quartzite), which is consistent with the geochemical study. Chemical …


Petrography And Palynology Of Late Oligocene And Middle Miocene Coals In The Gelibolu Peninsula, Nw Turkey, Ferdi̇ Demi̇rtaş, Mustafa Bozcu, Erdal Koşun, Mehmet Serkan Akki̇raz Jan 2015

Petrography And Palynology Of Late Oligocene And Middle Miocene Coals In The Gelibolu Peninsula, Nw Turkey, Ferdi̇ Demi̇rtaş, Mustafa Bozcu, Erdal Koşun, Mehmet Serkan Akki̇raz

Turkish Journal of Earth Sciences

In this study, coal samples from two different coal zones located close to each other were examined. They occur in the Late Oligocene Osmancık and Miocene Gazhanedere formations in the Gelibolu peninsula, in the SW part of the Thrace Basin (NW Turkey). This paper focuses on the organic-petrographic composition and depositional conditions of the two coal zones by using coal petrography, including maceral ratios, and palynology. The maceral composition of the Oligocene coal samples is similar to that of the Miocene coal samples. The coal samples from both locations are characterized by a high content of huminite group macerals, ranging …


Thuringian Affinity Of The Silurian?Lower Devonian Succession From The Eastern Taurus, Turkey, Valeri Sachanski, Hüseyi̇n Kozlu, Mehmet Cemal Göncüoğlu Jan 2015

Thuringian Affinity Of The Silurian?Lower Devonian Succession From The Eastern Taurus, Turkey, Valeri Sachanski, Hüseyi̇n Kozlu, Mehmet Cemal Göncüoğlu

Turkish Journal of Earth Sciences

The Silurian-Lower Devonian succession in the Değirmentaş-Halevikdere section (E Taurides) shows considerable lithostratigraphic similarities to the three-partite subdivision, initially documented in the same stratigraphic interval in Saxo-Thuringia and later in other peri-Gondwanan terrains. The Llandovery-Wenlockian part of the studied section (ca. 40 m) is characterized by black graptolitic shales. The Llandoverian part is dominated by radiolarian ribbon cherts (ca. 20 m). The Rhuddanian Akidograptus ascensus, Parakidograptus acuminatus, and Cystograptus vesiculosus biozones have been recognized in its lower part, while in the upper part of the succession, the lowermost Telychian Rastrites linnaei Biozone has been documented. The Telychian Spirograptus turriculatus and …


Studies On Mass Attenuation Coefficient, Mass Energy Absorption Coefficient, And Kerma For Fe Alloys At Photon Energies Of 17.44 To 51.70 Kev, Demet Yilmaz, Yusuf Şahi̇n, Lütfü Demi̇r Jan 2015

Studies On Mass Attenuation Coefficient, Mass Energy Absorption Coefficient, And Kerma For Fe Alloys At Photon Energies Of 17.44 To 51.70 Kev, Demet Yilmaz, Yusuf Şahi̇n, Lütfü Demi̇r

Turkish Journal of Physics

The mass attenuation coefficient (mu_m), the mass energy absorption coefficient (mu_{en}/ rho), and kerma relative to air were determined for some alloys, namely Fe_{0.5}Cr_{0.5}, Fe_{0.7}Cr_{0.3}, Fe_{0.8}Cr_{0.2}, Fe_{0.9}Cr_{0.1}, Fe_{0.2}Ni_{0.8}, Fe_{0.3}Ni_{0.7}, Fe_{0.5}Ni_{0.5}, Fe_{0.6}Ni_{0.4}, Fe_{0.7}Ni_{0.3}, and Fe_{0.8}Ni_{0.2}, at 17.44, 19.63, 22.10, 24.90, 32.06, 36.39, 37.26, 43.74, 44.48, 50.38, and 51.70 photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. The experimental results of mu_m were compared with the theoretical results. The theoretical values of mu_{en}/ rho were compared with the semiempirical values. It was observed that kerma values relative to air values were different in Fe-Ce …


A Computational Study On The Interaction Between O$_{2}$ And Pristine And Ge-Doped Aluminum Phosphide Nanotubes, Mahdi Rezaei Sameti, Alireza Kazemi Jan 2015

A Computational Study On The Interaction Between O$_{2}$ And Pristine And Ge-Doped Aluminum Phosphide Nanotubes, Mahdi Rezaei Sameti, Alireza Kazemi

Turkish Journal of Physics

In this research the interaction between oxygen molecules and the outside and inside surfaces of pristine and Ge-doped (4,4) armchair and (6,0) zigzag models of aluminum phosphide nanotubes (AlPNTs) was systematically investigated using density function theory. Structural parameters, adsorption energy, quantum parameters, HOMO/LUMO orbitals, and nuclear quadrupole resonance (NQR) parameters were calculated for all models of AlPNTs. The aim of this work was to investigate the effects of Ge doping and O$_{2}$ adsorption on the electrical and structural parameters of (4,4) armchair and (8,0) zigzag models of AlPNTs. The results revealed that adsorption energies for all models were negative with …


Description Of The Yrast Superdeformed Bands In Even-Even Nuclei In A $\Sim$ 190 Region Using The Nuclear Softness Model, Ali Khalaf, Karima Abdelmageed, Manal Sirag Jan 2015

Description Of The Yrast Superdeformed Bands In Even-Even Nuclei In A $\Sim$ 190 Region Using The Nuclear Softness Model, Ali Khalaf, Karima Abdelmageed, Manal Sirag

Turkish Journal of Physics

A two-parameter nuclear softness (NS2) model for the transition energies is proposed by treating the variation of the moment of inertia with spin. The model has been applied to the yrast superdeformed (SD) bands in even-even nuclei in the mass region A $\sim $ 190. The model parameters have been determined from the fitting procedure in order to minimize the relative root mean square deviation between the experimental E2 transition $\gamma $-ray energies and the calculated ones. The basic experimental data on SD bands are given in the form of a series of $\gamma $-ray transitional energies and the spins …


Secondary Metabolites From Sambucus Ebulus, İrem Atay, Hasan Kirmizibekmez, Ahmet Ceyhan Gören, Erdem Yeşi̇lada Jan 2015

Secondary Metabolites From Sambucus Ebulus, İrem Atay, Hasan Kirmizibekmez, Ahmet Ceyhan Gören, Erdem Yeşi̇lada

Turkish Journal of Chemistry

A new nonglycosidic iridoid, sambulin B (1), was isolated from the methanol extract of Sambucus ebulus L. leaves along with a recently reported new nonglycosidic iridoid, 10-O-acetylpatrinoside aglycone (sambulin A) (2); 2 flavonoids, isorhamnetin-3-O-\beta-D-glucopyranoside (3) and isorhamnetin-3-O-rutinoside (4); and a mixture of 2 flavonoids (5), quercetin-3-O-\beta-D-glucopyranoside and quercetin-3-O-\beta-D-galactopyranoside. Their structures were elucidated by 1-D and 2-D nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS) experiments.


Amperometric Biosensing Of Ethanol Based On Integration Of Alcohol Dehydrogenase With A Pt/Ppy--Pvs/Mb Electrode, Özlem Çolak, Fatma Arslan Jan 2015

Amperometric Biosensing Of Ethanol Based On Integration Of Alcohol Dehydrogenase With A Pt/Ppy--Pvs/Mb Electrode, Özlem Çolak, Fatma Arslan

Turkish Journal of Chemistry

A novel amperometric ethanol biosensor with alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide (NAD^+) on polypyrrole--polyvinylsulfonate (PPy-PVS) film was accomplished. Meldola's blue (MB) was used as a mediator; it can facilitate the electron transfer that involves a chemical interaction between the electrode surface and NADH. Determination of ethanol was carried out by the oxidation of MB at --0.072 V vs. Ag/AgCl. The effects of pH and temperature were investigated and optimum parameters were found to be 7.0 and 40 °C, respectively. There are 2 linear parts at 1.0 \mu M--10.0 \mu M (R^2 = 0.993) and 0.01 mM--0.1 mM (R^2 …


Purification And Characterization Of Nadph-Cytochrome P450 Reductase From Lake Van Fish Liver Microsomes And Investigation Of Some Chemical And Metals' Effects On The Enzyme Activity, Müslüm Kuzu, Mehmet Çi̇ftci̇ Jan 2015

Purification And Characterization Of Nadph-Cytochrome P450 Reductase From Lake Van Fish Liver Microsomes And Investigation Of Some Chemical And Metals' Effects On The Enzyme Activity, Müslüm Kuzu, Mehmet Çi̇ftci̇

Turkish Journal of Chemistry

NADPH-cytochrome P450 reductase was purified from Lake Van fish liver microsomes by primary and secondary DEAE-cellulose column chromatograph with 20.46 \mu M/min/mg enzyme specific activities, 54.4% purification yield, and purification of 38-fold. The purity of the enzyme was established, and its monomer molecular weight was determined by SDS-polyacrylamide gel electrophoresis. SDS-PAGE results showed a single band and the molecular weight of NADPH-cytochrome P450 reductase was 70 kDa. In addition, optimum ionic strength, optimum pH, optimum temperature, and stable pH values were determined for the enzyme in the kinetic studies performed. K_M and V_{max} were determined for NADPH and cytochrome c. …


Low-Cost Sliding Mode Control Of Wecs Based On Dfig With Stability Analysis, Abdelhak Djoudi, Hachemi Chekireb, El Madjid Berkouk, Seddik Bacha Jan 2015

Low-Cost Sliding Mode Control Of Wecs Based On Dfig With Stability Analysis, Abdelhak Djoudi, Hachemi Chekireb, El Madjid Berkouk, Seddik Bacha

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this work is to developing sliding mode control of active and reactive stator powers produced by a wind energy conversion system (WECS), based on doubly fed induction generator (DFIG). A flux estimation model and rotor current sensor are no longer required. The controller is developed from the DFIG nonlinear-coupled model. Moreover, the global stability and the DFIG states' boundedness when our low-cost sliding mode control is applied are established analytically. It is revealed that the $(dq)$ components of the rotor flux remain near their nominal values. Our approach is validated via simulation in the case of a …


Synthesis Of Methyl 4-(9h-Carbazole-9-Carbanothioylthio) Benzoate: Electropolymerization And Impedimetric Study, Murat Ateş, Nesi̇mi̇ Uludağ, Fati̇h Arican, Tolga Karazehi̇r Jan 2015

Synthesis Of Methyl 4-(9h-Carbazole-9-Carbanothioylthio) Benzoate: Electropolymerization And Impedimetric Study, Murat Ateş, Nesi̇mi̇ Uludağ, Fati̇h Arican, Tolga Karazehi̇r

Turkish Journal of Chemistry

Methyl 4-((9H-(carbazole-9-carbanothioylthio) benzoate (MCzCTB) was chemically synthesized and characterized by FTIR, ^1H NMR, and ^{13}C NMR. A novel synthesized monomer was electropolymerized on a glassy carbon electrode (GCE) in various initial molar concentrations of [MCzCTB]_0= 1, 3, 5, and 10 mM in 0.1 M NaClO_4/CH_3CN and 1 M H_2SO_4. P(MCzCTB)/GCE was characterized by cyclic voltammetry, Fourier transform infrared-attenuated transmittance reflectance, scanning electron microscopy-energy dispersive X-ray, and electrochemical impedance spectroscopy. The capacitive behavior of the modified electrode was obtained by Nyquist, Bode-magnitude, and Bode-phase plots. The highest capacitance at low frequency was obtained as \sim 53.1 mF cm^{-2} from Nyquist plot …


Synthesis, Structural Characterization, And Antimicrobial Efficiency Of Sulfadiazine Azo-Azomethine Dyes And Their Bi-Homonuclear Uranyl Complexes For Chemotherapeutic Use, Abdalla M. Khedr, Fawaz A. Saad Jan 2015

Synthesis, Structural Characterization, And Antimicrobial Efficiency Of Sulfadiazine Azo-Azomethine Dyes And Their Bi-Homonuclear Uranyl Complexes For Chemotherapeutic Use, Abdalla M. Khedr, Fawaz A. Saad

Turkish Journal of Chemistry

Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO_2(II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HL^I and HL^{II}) using a modified literature procedure. The structures of the ligands and their UO_2(II)-complexes were elucidated by conventional and thermal gravimetric analyses, molar conductivity, magnetic susceptibility, and IR, UV-Vis, ^1H NMR, and mass spectra. The analytical and spectral data supported the binuclear formulation of the complexes with a 2:1 metal to ligand ratio and octahedral geometry. The molar …


The Synthesis Of 1,3-Dialkyl-4-Methylimidazolinium Salts And Their Application In Palladium Catalyzed Heck Coupling Reactions, Murat Yi̇ği̇t, Güli̇n Bayam, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r Jan 2015

The Synthesis Of 1,3-Dialkyl-4-Methylimidazolinium Salts And Their Application In Palladium Catalyzed Heck Coupling Reactions, Murat Yi̇ği̇t, Güli̇n Bayam, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

Seven novel 1,3-dialkyl-4-methylimidazolinium chloride salts 3a--g were prepared as precursors of N-heterocyclic carbenes by reacting N,N'-alkyl-1,2-diaminopropane, triethyl orthoformate, and ammonium chloride. The salts were characterized spectroscopically. The in situ prepared palladium complexes derived from the imidazolinium salts and palladium acetate were used as catalyst in Heck coupling reactions between aryl bromides and styrene. The corresponding Heck products were obtained in good yields.


Selective Co Methanation Over Nio--Al_2o_3--Zro_2 And Co_3o_4--Al_2o_3--Zro_2 Catalysts, Fi̇li̇z Derekaya, Derya Ermergen Jan 2015

Selective Co Methanation Over Nio--Al_2o_3--Zro_2 And Co_3o_4--Al_2o_3--Zro_2 Catalysts, Fi̇li̇z Derekaya, Derya Ermergen

Turkish Journal of Chemistry

NiO--Al_2O_3--ZrO_2 and Co_3O_4--Al_2O_3--ZrO_2 catalysts were prepared by three different co-precipitation methods, namely co-precipitation, surfactant-assisted co-precipitation, and surfactant-assisted co-precipitation with ultrasound mixing methods, and their activities were tested in selective CO methanation. Catalysts were characterized using N_2 physisorption, XRD, SEM, TEM, XPS, and TPR-H_2 techniques. CO methanation and selective CO methanation reactions were carried out. Catalysts prepared by surfactant assisted co-precipitation gave high surface area, uniform pore size distributions, and small pores. The NiO--Al_2O_3--ZrO_2 catalyst prepared by surfactant-assisted co-precipitation gave 50% CO conversion to CH_4 at 155 °C and all CO converted to CH_4 when T > 225 °C. For the selective …


Redox Polymerization Of N-Isopropylacrylamide By Using Hydroxylated Soya Oil Polymer, Abdulkadi̇r Alli, Ti̇mur Şanal, Baki̇ Hazer Jan 2015

Redox Polymerization Of N-Isopropylacrylamide By Using Hydroxylated Soya Oil Polymer, Abdulkadi̇r Alli, Ti̇mur Şanal, Baki̇ Hazer

Turkish Journal of Chemistry

Water soluble hydroxylated soya oil polymer was used in the redox polymerization of N-isopropylacrylamide (NIPAM) in order to obtain water-based hydroxylated-soya oil polymer-g-PNIPAM graft copolymer. For this purpose, soya oil was exposed to air under sunlight to obtain autoxidized soya oil polymer (PSy-ox). PSy-ox was allowed to react with diethanol amine to obtain hydroxylated soya oil polymer (hydroxylated-PSy). An ammonium persulfate with hydroxylated-PSy redox initiating system was used in the polymerization of NIPAM in order to obtain thermo-responsive hydroxylated-PSy-g-PNIPAM water-based graft copolymers. The graft copolymers were characterized using proton nuclear magnetic resonance, Fourier transform infrared~spectroscopy, gel permeation chromatography, thermal gravimetric …


Gaseous And Dissolved Oxygen Sensing With Stabilized Pyrene In Ionic Liquid Modified Electrospun Slides, Özlem Öter, Gülhan Sabanci Şahi̇n Jan 2015

Gaseous And Dissolved Oxygen Sensing With Stabilized Pyrene In Ionic Liquid Modified Electrospun Slides, Özlem Öter, Gülhan Sabanci Şahi̇n

Turkish Journal of Chemistry

Pyrene dye has many superior characteristics for oxygen sensing studies such as long fluorescence lifetime, high quantum yield, and good sensitivity. It is preferred in some cases over ruthenium dyes for its more lipophilic character and higher sensitivity. However, easy photodegradation of pyrene is a challenging problem. In this study, pyrene dye was for the first time immobilized in an ethyl cellulose matrix and used for oxygen sensing in the form of thin films and electrospun sensing slides. The hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was used as additive for the first time for dissolved oxygen sensing studies. The oxygen sensitivity …


Synthesis, Characterization, And Metal Extraction Studies Of A New Macrobicyclic Ligand, Hali̇l Zeki̇ Gök, Yaşar Gök, Esra Eker Jan 2015

Synthesis, Characterization, And Metal Extraction Studies Of A New Macrobicyclic Ligand, Hali̇l Zeki̇ Gök, Yaşar Gök, Esra Eker

Turkish Journal of Chemistry

This article describes the synthesis, characterization, and metal ion binding properties of a new macrobicyclic ligand. Solvent extraction experiments were performed in order to determine the extraction behavior of new macrobicyclic ligand towards selected metal cations. Selective extraction of heavy metals and precious metals is highly demanded due to their toxicity and commercial importance. Based on our experimental results, macrobicyclic ligand 3 demonstrated remarkable affinity towards the Ag^+ ion by 96.7% and 96.9% to the dichloromethane and chloroform phases, respectively. The extraction experiments with macrobicyclic ligand 3 for the Ag^+ ion were repeated at different temperatures to calculate thermodynamic parameters. …


Two New Coordination Polymers Containing Dicyanidoargentate(I) And Dicyanidoaurate(I): Synthesis And Characterization, And A Detailed In Vitro Investigation Of Their Anticancer Activities On Some Cancer Cell Lines, Ali̇ Aydin, Ahmet Karadağ, Şaban Teki̇n, Nesri̇n Korkmaz, Aslihan Özdemi̇r Jan 2015

Two New Coordination Polymers Containing Dicyanidoargentate(I) And Dicyanidoaurate(I): Synthesis And Characterization, And A Detailed In Vitro Investigation Of Their Anticancer Activities On Some Cancer Cell Lines, Ali̇ Aydin, Ahmet Karadağ, Şaban Teki̇n, Nesri̇n Korkmaz, Aslihan Özdemi̇r

Turkish Journal of Chemistry

Two novel cyanido-bridged bimetallic polymeric complexes, [Ni(edbea)Ag$_{3}$(CN)$_{5}$]$_{n} $(C1) and [Ni(bishydeten) Au$_{2}$(CN)$_{4}$]$_{n}$ (C2), where edbea = [2,2$' $-(ethylenedioxy)bis(ethylamine)] and bishydeten = [($N$,$N' $-bis(2-hydroxyethyl) ethylenediamine)] are ligands, were synthesized and characterized by elemental, infrared, and thermal measurement techniques and investigated for their biological activity in cultured cancer cell lines. The results show that both compounds and free anions, [Ag(CN)$_{2}$]$^{-}$ and [Au(CN)$_{2}$]$^{-}$, exhibited very high antiproliferative activity compared to the anticancer drug 5FU against the cancer cell lines tested. The antiproliferative and cytotoxic activities of C1 and C2 were significantly lower than those of free anions, indicating that the extreme cytotoxicity of free …


Synthesis Of Bis-Thiazoles, Bis-Pyrazoles, Bis-Hydrazonates, And Bis-Triazolothiadiazoles Based On Bis-Hydrazonoyl And Bis-Hydrazones, Abdelwahed Sayed Jan 2015

Synthesis Of Bis-Thiazoles, Bis-Pyrazoles, Bis-Hydrazonates, And Bis-Triazolothiadiazoles Based On Bis-Hydrazonoyl And Bis-Hydrazones, Abdelwahed Sayed

Turkish Journal of Chemistry

A facile synthesis of bis-thiazoles, bis-pyrazoles, and bis-hydrazonates from the reaction of bis-hydrazonoyl dichlorides with different moieties is described. Bis-triazolothiadiazoles were synthesized via oxidative cyclization of bis-hydrazones. Structures of the final product were elucidated by elemental analyses and spectral data.