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Articles 8281 - 8310 of 10319
Full-Text Articles in Physical Sciences and Mathematics
Chemical Constituents Of Galium Tortumense, Zühal Güvenalp, Nurcan Kiliç, Cavi̇t Kazaz, Yusuf Kaya, L. Ömür Demi̇rezer
Chemical Constituents Of Galium Tortumense, Zühal Güvenalp, Nurcan Kiliç, Cavi̇t Kazaz, Yusuf Kaya, L. Ömür Demi̇rezer
Turkish Journal of Chemistry
From the aerial parts of Galium tortumense Ehrend & Schönb.-Tem., 8 iridoid glycosides, a flavonol glycoside, a oleanane-type triterpene acid, an ursan-type triterpene acid and a sterol were isolated. The structures of the compounds were elucidated by high field 1D and 2D NMR and EIMS spectroscopies.
Iridoids, Flavonoids And Monoterpene Glycosides From Galium Verum Subsp. Verum, L. Ömür Demi̇rezer, Fi̇li̇z Gürbüz, Zühal Güvenalp, Karsten Ströch, Axel Zeeck
Iridoids, Flavonoids And Monoterpene Glycosides From Galium Verum Subsp. Verum, L. Ömür Demi̇rezer, Fi̇li̇z Gürbüz, Zühal Güvenalp, Karsten Ströch, Axel Zeeck
Turkish Journal of Chemistry
From the aerial parts of Galium verum subsp. verum L. were isolated 7 iridoid glycosides, asperuloside (1), asperulosidic acid (2), deacetyl-asperulosidic acid (3), monotropein (4), 6-O-epi-acetylscandoside (5), daphylloside (6) and deacetyl-daphylloside (7); 2 flavonol glycosides, astragalin [= kaempferol 3-O-\beta-glucopyranoside] (8) and rutin [= quercetin 3-O- rutinoside] (9); and 2 monoterpene glycosides, betulalbuside A (10) and (2E)-2,6-dimethyl-2,7-octadien-1,6-diol-6-O-\beta -glucopyranoside (11). The structures of the isolates were established by 1D and 2D NMR spectroscopy in combination with IR, UV and ESI-MS analysis.
Dichloride[1-(2,4,6-Trimethylbenzyl)-3-(Biphenyl-2-Ylmethyl)-Imidazolidin- 2-Ylidine (\Eta^6-Hexamethylbenzene)]Ruthenium, Hakan Arslan, Donald Van Derveer, İsmai̇l Özdemi̇r, Sedat Yaşar, Beki̇r Çeti̇nkaya
Dichloride[1-(2,4,6-Trimethylbenzyl)-3-(Biphenyl-2-Ylmethyl)-Imidazolidin- 2-Ylidine (\Eta^6-Hexamethylbenzene)]Ruthenium, Hakan Arslan, Donald Van Derveer, İsmai̇l Özdemi̇r, Sedat Yaşar, Beki̇r Çeti̇nkaya
Turkish Journal of Chemistry
The single crystal X-ray structure of the imidazolidin ruthenium complex, C_{38}H_{46}N_2Cl_2Ru, was determined. The complex is an orthorhombic space group Pbca with a = 17.3586(32) Å, b = 14.4447(27) Å, c = 27.4325(52) Å, and V = 6878.466(4) Å^3 with Z = 8 for D_{calc} = 1.357 g/cm^3. It exhibits the expected 3-legged piano stool geometry. There is one coordination bond of the ruthenium atom with the electrons of the \eta^6-hexamethylbenzene, 2 symmetrical Ru-Cl bonds, and one Ru-C bond involving the imidazole ring. The coordination around the ruthenium atom is 4-fold, which in this is case is pseudo-tetrahedral.
Performance Comparison Between Monolithic C18 And Conventional C18 Particle-Packed Columns In The Liquid Chromatographic Determination Of Propranolol Hcl, Sami El Deeb, Hermann Watzig
Performance Comparison Between Monolithic C18 And Conventional C18 Particle-Packed Columns In The Liquid Chromatographic Determination Of Propranolol Hcl, Sami El Deeb, Hermann Watzig
Turkish Journal of Chemistry
Monolithic and conventional particle-packed columns were applied for the determination of propranolol hydrochloride in the presence of its 2 main degradation products, 3-(1-naphthyloxy)-propane-1,2- diol and 4-isopropyl-1,7-bis-(1-naphthyloxy)-4-azaheptane-2,6-diol. The separations were investigated on monolithic columns at flow rates from 1 to 9 mL/min. Fast and efficient separation was obtained by monolithic columns. The analysis time was decreased by about 5-fold on monolithic columns at a flow rate of 4 mL/min, while maintaining sufficient resolution between propranolol and its degradation products. The method was validated using a set of 3 monolithic columns and compared to a conventional (Superspher) C18 column. The precision for …
Synthesis Of Some New Functionalized Octasilsesquioxane Hybrid Nanoclusters. Iii. Potential Of The Octameric Clusters As Hydraulic Lubricating Fluids, Enock O. Dare
Turkish Journal of Chemistry
The reaction of suitable organic compounds such as \omega -halo-1-alkenes, allyltrichlorosilane or 2-methyl-3-butyn-2-ol in combination with a well-defined inorganic silsesquioxane, H_8Si_8O_{12} A cores, leads to covalently bound organic-inorganic hybrid materials in high yields. The hydraulic fluid properties of these viscous hybrid materials were evaluated and compared with those of some commercially available hydraulic fluids: Mobil EAL 224H, Super-V (AP) and Puroil SHO. The results showed that most silsesquioxane semi-liquids possess hydraulic fluid properties comparable to those of the 3 commercial lubricants.
Superabsorbency, Ph-Sensitivity And Swelling Kinetics Of Partially Hydrolyzed Chitosan-G-Poly(Acrylamide) Hydrogels, Ali Pourjavadi, Gholam Reza Mahdavinia
Superabsorbency, Ph-Sensitivity And Swelling Kinetics Of Partially Hydrolyzed Chitosan-G-Poly(Acrylamide) Hydrogels, Ali Pourjavadi, Gholam Reza Mahdavinia
Turkish Journal of Chemistry
Acrylamide (AAm) monomer was directly grafted onto chitosan using ammonium persulfate (APS) as an initiator and methylenebisacrylamide (MBA) as a crosslinking agent under an inert atmosphere. Two factors affecting the swelling capacity of the obtained hydrogel, AAm and MBA concentrations, were studied. The polymer structures were characterized by FTIR spectroscopy. Water absorbencies of the hydrogels were compared between before and after the alkaline hydrolysis treatment. Saponification of chitosan-g-poly(acrylamide) (chitosan-g-PAAm) with a hot sodium hydroxide solution gave rise to a high water absorbency. Swelling of the hydrogel samples in saline solution (0.15 mol/L NaCl, CaCl_2 and AlCl_3) was examined. Swelling capacity …
Synthesis And Vibrational Spectroscopic Study Of Some Metal(Ii) Halide And Tetracyanonickelate Complexes Of Isonicotinic Acid, Ahmet Ataç, Fehmi̇ Bardak
Synthesis And Vibrational Spectroscopic Study Of Some Metal(Ii) Halide And Tetracyanonickelate Complexes Of Isonicotinic Acid, Ahmet Ataç, Fehmi̇ Bardak
Turkish Journal of Chemistry
The M(IN)_2Ni(CN)_4 [where M: Cu, Mn, Zn, IN: Isonicotinic acid, abbreviated to M-Ni-IN] tetracyanonickelate and some metal halide complexes with the following stoichiometries: Cu(IN)X_2 (X:Br,I), Cd(IN)_2X_2, (X:Cl,Br), and Zn(IN)_4X_2 (X:Br,I) were synthesized for the first time. Their FT-IR spectra were reported in the 4000-400 cm^{-1} region. Vibrational assignments were given for all the observed bands. The analysis of the vibrational spectra indicates that there are some structure-spectrum correlations. For a given series of isomorphous complexes, the sum of the difference between the values of the vibrational modes of uncoordinated isonicotinic acid that were coordinated to the metal ion isonicotinic acid …
Attempted Synthesis Of 1-Cyclohepta-1,2-Dien-1-Ylbenzene And Wurtz-Like Condensation Products In The Reaction Of 1-(2,3-Dibromocyclohept-1-En-1-Yl)Benzene With Zinc, Mustafa Ceylan, Yakup Budak, M. Burcu Gürdere
Attempted Synthesis Of 1-Cyclohepta-1,2-Dien-1-Ylbenzene And Wurtz-Like Condensation Products In The Reaction Of 1-(2,3-Dibromocyclohept-1-En-1-Yl)Benzene With Zinc, Mustafa Ceylan, Yakup Budak, M. Burcu Gürdere
Turkish Journal of Chemistry
7,7-Dibromo-1-phenylbicyclo[4.1.0]heptane 4 was synthesized and its thermal and silver ion-catalyzed rearrangements were studied. Alcohol 8 was converted to 1-(2,3-dibromocyclohept-1-en-1-yl)benzene 6. The zinc-mediated elimination of 1-(2,3-dibromocyclohept-1-en-1-yl)benzene 6 resulted in the formation of 2 isomeric Wurtz-like condensation products 15 and 16 (whose structural assignments were based on ^1H-and ^{13}C-NMR spectral data) instead of the expected 1-cyclohepta-1,2-dien-1-ylbenzene 14.
A New Flame-Retardant Polyamide Containing Phosphine Oxide And N,N-(4,4-Diphenylether) Moieties In The Main Chain: Synthesis And Characterization, Khalil Faghihi
Turkish Journal of Chemistry
A new flame-retardant polyamide containing phosphine oxide moieties in the main chain was synthesized from the solution polycondensation reaction of bis(3-aminophenyl) phenyl phosphine oxide with N,N-(4,4-diphenylether) bis trimellitimide, using thionyl chloride, N-methyl-2-pyrolidone, and pyridine as condensing agents. This new polymer was obtained in high yield (92%), has high inherent viscosity (0.73 dL/g), and was characterized by elemental analysis, FT-IR spectroscopy, thermal gravimetric analysis (TGA and DTG), and solubility testing. Furthermore, another polyamide was prepared by the solution polycondensation reaction of N,N-(4,4-diphenylether) bis trimellitimide with 1,4-phenylene diamine, and its flame-retardant behavior was compared to that of the previous one.
The Impact Of Polyacrylamide Molecular Weight On Its Adsorption Behavior At The Gold/Acidic Solution Interface, Dragica B. Chamovska, Toma P. Grchev, Maja V. Cvetkovska
The Impact Of Polyacrylamide Molecular Weight On Its Adsorption Behavior At The Gold/Acidic Solution Interface, Dragica B. Chamovska, Toma P. Grchev, Maja V. Cvetkovska
Turkish Journal of Chemistry
Adsorption isotherms for polyacrylamide (PAA) on polycrystalline gold, from sulfuric acid (potential range 0-2.0 V/she; 293 K), were obtained by means of cyclic voltammetry with simultaneous monitoring of the double-layer capacity. The Frumkin isotherm indicates that relatively strong attractive forces are present (a = 0.8-1.0), and the Gibbs energies range between 43 and 56 kJ mol^{-1}. The coverage (\theta) of the metal surface with polymer molecules depends on the molar concentration of PAA, as well as on its molecular weight, and the size of the statistical polymer coil in the solution (R_G = 7.49 \times 10^{-3} \times M_n^{0.64}/nm). The adsorption …
Simple Synthesis Of \Alpha -Oxime Derivatives Of 2-Ketomethyl Quinolines Under Mild And Heterogeneous Conditions, Javad Safari, Mehdi Adib, Firouzeh Sheibani, Zahra Sadeghi
Simple Synthesis Of \Alpha -Oxime Derivatives Of 2-Ketomethyl Quinolines Under Mild And Heterogeneous Conditions, Javad Safari, Mehdi Adib, Firouzeh Sheibani, Zahra Sadeghi
Turkish Journal of Chemistry
2-Ketomethyl quinolines are converted to their \alpha-oximinoketone derivatives in quantitative yields using sodium nitrite in the presence of silica sulfuric acid as nitrosating agent under mild and heterogeneous conditions.
Synthesis And Properties Of Triazol-5-One Substituted Phthalocyanines By Microwave Irradiation, Bahatti̇n Kahveci̇, Selami̇ Şaşmaz, Musa Özi̇l, Ci̇han Kantar, Başak Koşar, Orhan Büyükgüngör
Synthesis And Properties Of Triazol-5-One Substituted Phthalocyanines By Microwave Irradiation, Bahatti̇n Kahveci̇, Selami̇ Şaşmaz, Musa Özi̇l, Ci̇han Kantar, Başak Koşar, Orhan Büyükgüngör
Turkish Journal of Chemistry
Triazol-5-one substituted phthalocyanines were prepared quickly by the reaction of 4-nitrophthalonitrile with anhydrous metal salts in DBU (1,8-diazabicyclo[5,4,0]undec-7-ene) and DMAE (dimethylaminoethanol) by microwave irradiation. Microwave yields were higher than those of the conventional synthesis methods. All of these complexes are insoluble in polar solvents such as ethanol, ethyl acetate and chloroform. The characterization of the compounds was accomplished by elemental analysis, ^1H NMR (for I and II), ^{13}C NMR (for I and II), IR and UV-Vis spectral data. In addition, the structure of the starting material (I) was determined by single crystal diffraction.
Synthesis, Spectroscopic (Ft-Ir, ^1h, ^{13}C, Mass Spectrometry), And Biological Investigation Of Five-Coordinated Germanium-Substituted Tricyclohexyl Antimony Dipropionates: Crystal Structure Of Tricyclohexylantimony Dibromide, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Kieran C. Molloy, Sarim Dastgir, Farkhanda Shaheen
Synthesis, Spectroscopic (Ft-Ir, ^1h, ^{13}C, Mass Spectrometry), And Biological Investigation Of Five-Coordinated Germanium-Substituted Tricyclohexyl Antimony Dipropionates: Crystal Structure Of Tricyclohexylantimony Dibromide, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Kieran C. Molloy, Sarim Dastgir, Farkhanda Shaheen
Turkish Journal of Chemistry
A series of five-coordinated germanium-substituted tricyclohexylantimony dipropionates have been synthesized and characterized by different instrumental techniques, such as elemental analyses, FT-IR, multinuclear NMR (^1H, ^{13}C) and mass spectrometry. These compounds have also been screened against different microbes and they showed good activity against different bacteria that was comparable to the reference drugs. The crystal structure of the precursor (C_6H_{11})_3SbBr_2 is reported here, which showed that the antimony atom in an asymmetric unit exists in trigonal bipyramidal geometry, having space group C2/c with the monoclinic crystal system.
Tkachenko Modes Of The Square Vortex Lattice In A Two-Component Bose-Einstein Condensate, M. Keçeli̇, M. Ö. Oktel
Tkachenko Modes Of The Square Vortex Lattice In A Two-Component Bose-Einstein Condensate, M. Keçeli̇, M. Ö. Oktel
Turkish Journal of Physics
We study Tkachenko modes of the square vortex lattice of a two-component Bose-Einstein condensate (BEC) in the mean-field quantum Hall regime, considering the coupling of these modes with density excitations. We derive the hydrodynamic equations and obtain the dispersion relations of the excitation modes. We find that there are two types of excitations, gapped inertial modes and gapless Tkachenko modes. These modes have two branches which we call acoustic and optical modes in analogy with phonons. The former has quadratic while the latter has linear wave-number dependence in both inertial and Tkachenko modes. Acoustic Tkachenko mode is found to be …
Dwba Of The Reaction ^0be(P, \Alpha )^6li At E_P = 18.6\Sim 50 Mev, S. E. Abdel-Kariem
Dwba Of The Reaction ^0be(P, \Alpha )^6li At E_P = 18.6\Sim 50 Mev, S. E. Abdel-Kariem
Turkish Journal of Physics
The compound nucleus produced in the reaction ^9Be(p, \alpha)^6Li in the incident energy range E_p = 18.6 \sim 50 MeV is mainly occurred when its excitation energy is greater than the \alpha -particle threshold separation energy by about 20 MeV, strongly suggesting the reaction mechanism is a direct one-step process. To understand this phenomenon, we employ semi-microscopic zero-range distorted-wave Born approximation (DWBA) theory to analyse experimental data obtained in this energy range for the lower three ^6Li-states: ground state (1^+; 0); 2.186 MeV (3^+; 0); and 3.563 MeV (0^+; 1). The Kurath-Millener spectroscopic-factor amplitudes for the triton-cluster transfer are used …
Relativistic Density Functional Theory Method: Applications To Autoionization States Of Atoms, Şaki̇r Erkoç
Relativistic Density Functional Theory Method: Applications To Autoionization States Of Atoms, Şaki̇r Erkoç
Turkish Journal of Physics
A brief introductory information about the accurate atomic calculations using Density Functional Theory has been reviewed. How relativistic effects can be considered in atomic calculations through the density functional theory has been discussed. Some sample calculation results for the autoionization states of the neutral and cationic atoms have been presented.
Applications Of Genetic Algorithm To Quantum Mechanical Systems, Mehmet Şahi̇n, Ülfet Atav, Mehmet Tomak
Applications Of Genetic Algorithm To Quantum Mechanical Systems, Mehmet Şahi̇n, Ülfet Atav, Mehmet Tomak
Turkish Journal of Physics
Genetic algorithm (GA) inspired by the biological world is a general search and optimization method. It was first proposed by Holland in 1975. GA has been applied to many scientific areas especially in engineering optimization problems. It is also used in solving of quantum mechanical problems. In this study, we have applied this method to different realistic quantum mechanical problems of both self-consistent and non-self-consistent type. The results obtained are compared with the results of other methods and it is seen that the GA can be a very powerful alternative to some other traditional techniques such as variational method.
First Principles Approach To Batio_3, Mustafa Uludoğan, Tahi̇r Çağin
First Principles Approach To Batio_3, Mustafa Uludoğan, Tahi̇r Çağin
Turkish Journal of Physics
We present state of art first-principles study on the static and dynamic properties of BaTiO_3, a typical ferroelectric material. Here, structure, equation of state, phase stability, and phase transformations of BaTiO_3 studied in Generalized Gradient Approximation. Furthermore, properties such as, Born effective charges, optical dielectric constant and phonon spectra are calculated from Density Functional Perturbation Theory.
Petrography And Geochemistry Of Paragneisses In The Çine Submassif Of The Menderes Massif, Western Anatolia, Firat Şengün, Osman Candan, O. Özcan Dora, O. Ersi̇n Koralay
Petrography And Geochemistry Of Paragneisses In The Çine Submassif Of The Menderes Massif, Western Anatolia, Firat Şengün, Osman Candan, O. Özcan Dora, O. Ersi̇n Koralay
Turkish Journal of Earth Sciences
The Menderes Massif, which covers a large area in western Turkey, is made up of Pan-African basement rocks and a Palaeozoic to Early Tertiary cover sequence. The study area is located in the Dalama and Hallaçlar (Aydın) area, in the northern and central parts of the Çine submassif of the Menderes Massif. The oldest units of the Pan-African basement are metaclastics, consisting of paragneisses and mica schists that gradually and conformably overlay paragneisses. Macroscopic appearances and mineralogical and textural data indicate that paragneisses can be subdivided into four subgroups. These are: (1) black spotted, (2) white spotted, (3) massive, grey-coloured …
Investigation Of Water Masses In İzmir Bay, Western Turkey, Erdem Sayin, İdi̇l Pazi, Canan Eronat
Investigation Of Water Masses In İzmir Bay, Western Turkey, Erdem Sayin, İdi̇l Pazi, Canan Eronat
Turkish Journal of Earth Sciences
The main purpose of this paper is to explore seasonal variability of the local hydrography and investigate the water masses, their seasonal and regional variations in the vicinity of İzmir Bay based on data sets collected between 1994 and 2003. The general water movement characteristics in the bay are provided by CTD data analysis together with Killworth's general circulation model. In the bay, three distinct water masses exist: ASW (Aegean Sea water), IBW (İzmir Bay water) and IBIW (İzmir Bay inner water). Generally, vertically homogenous ASW enters the bay from the north, near Karaburun in winter, and horizontally homogeneous ASW …
Contact Metamorphism Around The Eocene Saraycık Granodiorite, Eastern Pontides, Turkey, Gülteki̇n Topuz
Contact Metamorphism Around The Eocene Saraycık Granodiorite, Eastern Pontides, Turkey, Gülteki̇n Topuz
Turkish Journal of Earth Sciences
The Eocene Saraycık granodiorite, eastern Pontides, Turkey, is a small post-tectonic intrusive body (~11 km2), cross-cutting tectonically juxtaposed distinct metamorphic and non-metamorphic lithologies. A ~0.8 to 1-km-wide contact-metamorphic aureole has developed around the intrusion. Disequilibrium is prevalent in all lithologies, even in the inner zones of the contact aureole. Conditions of contact metamorphism are estimated by simple phase equilibria applied to microdomains in the metapelitic lithologies without obvious signs of disequilibrium: Shallow emplacement depths (0.21±0.05 GPa = ~5-8 km) are suggested by contact-metamorphic mineral assemblages (e.g., andalusite + corundum + K-feldspar), by Al-in-hornblende barometry on granodiorite and by partial melting …
Stratigraphic And Palaeoenvironmental Significance Of Bartonian–Priabonian (Middle–Late Eocene) Microfossils From The Başçeşme Formation, Denizli Province, Western Anatolia, M. Serkan Akki̇raz, Funda Akgün, Sefer Örçen, Angela Bruch, Volker Mosbrugger
Stratigraphic And Palaeoenvironmental Significance Of Bartonian–Priabonian (Middle–Late Eocene) Microfossils From The Başçeşme Formation, Denizli Province, Western Anatolia, M. Serkan Akki̇raz, Funda Akgün, Sefer Örçen, Angela Bruch, Volker Mosbrugger
Turkish Journal of Earth Sciences
This study explains the stratigraphical and palaeoenvironmental significance of Bartonian-Priabonian (Middle-Late Eocene) fossils, the fauna and flora obtained from the Başçeşme formation of the Çardak-Tokça basin (western Anatolia). The studied sequence is an outcrop from the Başçeşme formation, deposited in a shallow-marine to coastal environment without stratigraphic breaks. Forty genera and 58 species have been recognized in the palynological assemblage of the Başçeşme formation. A well-preserved diverse palynomorph and foraminiferal assemblages yield the Middle-Late Eocene age for the Başçeşme formation. In western Anatolia, mangrove elements Nypa and Pelliciera have been first recorded in this study. The pollen of Mauritia and …
Calcretized Ferricretes Around The Jaisalmer Area, Thar Desert, India: Their Chemistry, Mineralogy, Micromorphology And Genesis, D. Ramakrishnan, Krishna Chandra Tiwari
Calcretized Ferricretes Around The Jaisalmer Area, Thar Desert, India: Their Chemistry, Mineralogy, Micromorphology And Genesis, D. Ramakrishnan, Krishna Chandra Tiwari
Turkish Journal of Earth Sciences
Ferricrete, an iron duricrust, caps Tertiary and Mesozoic rocks around Jaisalmer in the Indian desert. These ferricretes are associated with two distinct present-day landforms. The upper unit is a high-level dissected, rocky structural plain and the lower one a colluvial flat with soft ferricrete gravels. This study pertains to the first situation wherein field observations, micromorphological features and regolith chemistry suggest an in situ origin for the ferricretes, as in the case of the Walther profile. Subsequent tectonism and changes in base level resulted in a shift in processes from weathering to erosion. Episodes of erosion resulted in inversion of …
Mineral-Chemical Constraints On The Miocene Calc-Alkaline And Shoshonitic Volcanic Rocks Of Western Turkey: Disequilibrium Phenocryst Assemblages As Indicators Of Magma Storage And Mixing Conditions, Ercan Aldanmaz
Turkish Journal of Earth Sciences
Early to Middle Miocene (22 to 15 Ma) volcanic activity across western Turkey produced a series of lavas and pyroclastic deposits with calc-alkaline and shoshonitic affinities. The erupted magmas show a broad range of compositions from basaltic to rhyolitic (48-75 SiO2 wt%) and are composed of variable phenocryst assemblages. Petrographic and mineral-chemical characteristics suggest that the magmas underwent hydrous crystallization in deep crustal magma chambers that was dominated by plagioclase + pyroxene + pargasitic amphibole fractionation. Subsequent crystallization in shallower magma chambers followed two different trends: (1) anhydrous (pyroxene + plagioclase-dominated); and (2) hydrous (plagioclase + edenitic amphibole + pyroxene-dominated). …
Geochemical Constraints On The Provenance, Mineral Sorting And Subaerial Weathering Of Lower Jurassic And Upper Cretaceous Clastic Rocks Of The Eastern Pontides, Yusufeli (Artvin), Ne Turkey, Abdurrahman Dokuz, Erkan Tanyolu
Geochemical Constraints On The Provenance, Mineral Sorting And Subaerial Weathering Of Lower Jurassic And Upper Cretaceous Clastic Rocks Of The Eastern Pontides, Yusufeli (Artvin), Ne Turkey, Abdurrahman Dokuz, Erkan Tanyolu
Turkish Journal of Earth Sciences
An integrated petrographic and geochemical study of the shales and sandstones of Early Jurassic and Late Cretaceous age in the Yusufeli area (Turkey) was carried out to obtain more information on their provenance, sedimentological history and tectonic setting, as well as to evaluate the influence of weathering, hydraulic sorting and recycling processes upon source-rock signature. Depending on their matrix and mineralogical content, the Lower Jurassic sandstones are identified as arkosic arenite and wacke, while the Upper Cretaceous sandstones are defined as lithic arenite and wacke. Elemental ratios such as La/Sc, Cr/Ni, Co/Th, Th/Sc and Cr/Th indicate a mafic source for …
Palynomorph, Foraminifera, And Calcareous Nannoplankton Biostratigraphy Of Oligo–Miocene Sediments In The Muş Basin, Eastern Anatolia, Turkey, Recep Hayretti̇n Sancay, Zühtü Bati, Uğraş Işik, Sabri̇ Kirici, Ni̇hal Akça
Palynomorph, Foraminifera, And Calcareous Nannoplankton Biostratigraphy Of Oligo–Miocene Sediments In The Muş Basin, Eastern Anatolia, Turkey, Recep Hayretti̇n Sancay, Zühtü Bati, Uğraş Işik, Sabri̇ Kirici, Ni̇hal Akça
Turkish Journal of Earth Sciences
Oligo-Miocene sediments have not been adequately studied biostratigraphically, and a detailed bio-chronostratigraphic framework has not yet been established in Eastern Anatolian basins. Palynomorphs have therefore been correlated with the biozonations of marine dinoflagellates, planktonic foraminifera and calcareous nannoplankton of similar latitudes in combined samples from the Ebulbahar and Kelereşdere measured stratigraphic sections, which are located in the northeastern part of Muş. Palynological (dinoflagellate), foraminiferal micropalaentological, and nannopalaeontological events, correlatable with worldwide defined biozonations, have been documented from uppermost Rupelian to Upper Miocene-Pliocene sediments. First occurrences (FOs) and and last occurrences (LOs) of selected dinoflagellates are important in establishing the biostratigraphic …
Reply To Comment On ‘Petrography And Petrology Of The Calc-Alkaline Sarıhan Granitoid (Ne Turkey): An Example Of Magma Mingling And Mixing’, Zafer Arslan
Turkish Journal of Earth Sciences
No abstract provided.
Optical Pulse Distortion In Fibonacci-Class Multilayer Stacks, A Rostami, S. Matloub
Optical Pulse Distortion In Fibonacci-Class Multilayer Stacks, A Rostami, S. Matloub
Turkish Journal of Physics
Optical pulse distortion and propagation through quasi-periodic structures generally and especially for Fibonacci-class, is investigated analytically and simulated numerically. In this analysis, the transfer matrix method (TMM) for distortion evaluation is used. The simulated results for Fibonacci-class quasi-periodic structures and pure periodic multilayer stacks are compared. We show that the Fibonacci-class quasi-periodic structure has a large dispersion coefficient with respect to a similar case in the periodic structure. So, quasi-periodic structures will destroy the incident pulse shape for smaller stack length than a periodic case in a similar situation. Finally, using output power, the distortion limit can be estimated and …
Tensor Polarization And Quadrupole Form Factor Of The Deuteron, A. K. A. Azzam, M. A. Fawzy, E. M. Hassan, A. M. Yasser
Tensor Polarization And Quadrupole Form Factor Of The Deuteron, A. K. A. Azzam, M. A. Fawzy, E. M. Hassan, A. M. Yasser
Turkish Journal of Physics
A new experimental value, M = 0.06925 \pm 0.00281, of the peak of the quadrupole form factor F_Q(q) is obtained by fitting the straight line relation found between the peak values of both T_{21}(q) and F_Q(q).
Dimensional Crossover In Semiconductor Structures: From 3d Electron Transport To Ballistic Electrons In 1d, Karl-Fredrick Berggren
Dimensional Crossover In Semiconductor Structures: From 3d Electron Transport To Ballistic Electrons In 1d, Karl-Fredrick Berggren
Turkish Journal of Physics
Modern semiconductor technologies have made possible special devices in which a gradual dimensional crossover may be induced by means of applied electric fields. Two specific examples are described. The first one is a special GaAs field effect transistor in which the thickness of the active electron gas layer may be varied by external voltages. With decreasing layer thickness transverse states become quantized and by depopulating the corresponding subbands a tunable dimensional crossover from 3D to 2D is achieved. The second example describes how a 2D to 1D crossover may be obtained in high-mobility split-gate GaAs/AlGaAs heterostructures. Effects of interactions in …