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Articles 8671 - 8700 of 10319
Full-Text Articles in Physical Sciences and Mathematics
Defect Structure And Properties Of Sr-Doped La Cr O_{3-\Delta}, Mahmoud Omari, Ilhem Chadli, Salah Belaidi
Defect Structure And Properties Of Sr-Doped La Cr O_{3-\Delta}, Mahmoud Omari, Ilhem Chadli, Salah Belaidi
Turkish Journal of Chemistry
A defect chemical model for the behavior of acceptor-doped LaCrO_3 as a function of oxygen pressure is proposed. This is considered within the regime that corresponds to oxygen deficit oxygen. The mathematical approach allows us to calculate the oxygen partial pressure dependant properties of La_{1-x} Sr_x Cr O_{3-\delta} in the range 0.10 \le x \le 0.30. The results show that the conductivity was independent of pO_2 and was proportional to the dopant concentration at high pO_2. Therefore, under reducing conditions, the conductivity decreased exponentially with decreasing pO_2 and asymptotically approached a pO_2^{1/4} relationship. Stability regimes and compensation mechanisms at various …
Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci
Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci
Turkish Journal of Chemistry
Three isoenzymes of polyphenol oxidase (PPO) were isolated from a local pear variety (Ankara Armutu) through ammonium sulfate precipitation, dialysis and gel filtration. The sample obtained from dialysis after ammonium sulfate precipitation was used for characterization of the partially purified enzyme. Optimum pH values of PPO were 8.2 for pyrogallol, 7.2 for 4-methylcatechol, 7.0 for catechol, 5.6 for D-tyrosine, 5.0 for p-cresol and 4.8 for L-dopa. The optimum temperature of PPO was 35 °C with 4-methylcatechol. Catechol was oxidized more rapidly than the other substrates; however, 4-methylcatechol, chlorogenic acid and caffeic acid were also good substrates. The effect of 6 …
Synthesis Of Novel 4-Alkylidene- And 4-Alkylamino-5-Oxo-4,5-Dihydro-[1,2,4] Triazole Derivatives And Investigation Of Their Antitumor Activities, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Synthesis Of Novel 4-Alkylidene- And 4-Alkylamino-5-Oxo-4,5-Dihydro-[1,2,4] Triazole Derivatives And Investigation Of Their Antitumor Activities, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Turkish Journal of Chemistry
A series of novel 3-alkyl-4-cyclohexylmethylenamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (6a-e) and 3-alkyl-4-hexylidenamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (7b-e) were synthesized from the reaction of corresponding 3-alkyl-4-amino-5-oxo-4,5-dihydro-[1,2,4]triazoles (1) with cyclohexancarboxaldehyde and capronaldehyde. The acetylation of compounds 6e and 7b resulted in the formation of 1-acetyl-4- cyclohexylmethylenamino-5-oxo-3-(p-tolyl)-4,5-dihydro-[1,2,4]triazole (10) and 3-benzyl-4-hexylidenamino-5-oxo-4,5-dihydro-[1,2,4]triazole (11). 3-Alkyl-4-cyclohexylmethylamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (8a-e) and 3-alkyl-4-hexylamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (9b-e) were obtained from the selective reduction of compounds 6a-e and 7b-e with NaBH_4. The in vitro antitumor activity of some selected compounds was screened by the National Cancer Institute (USA) against several human tumor cell lines, and compounds 8c, 9d and 11c were found to be active.
Rapid Complexometric Determination Of Mercury(Ii) Using Glutathione As A Selective Demasking Reagent, Prakash Shetty, A. Nithyananda Shetty
Rapid Complexometric Determination Of Mercury(Ii) Using Glutathione As A Selective Demasking Reagent, Prakash Shetty, A. Nithyananda Shetty
Turkish Journal of Chemistry
A simple, rapid and selective complexometric method is proposed for the determination of mercury(II) in the presence of associated metal ions. Mercury(II) is first complexed with an excess of EDTA and the surplus EDTA is titrated against standard zinc sulphate solution at pH 5-6 using xylenol orange indicator. Glutathione is then added to displace EDTA from the Hg-EDTA complex quantitatively and the EDTA released is back titrated against a standard zinc sulphate solution as before. The method works well in the range 4 to 80 mg of mercury with a relative error of less than 0.30% and a coefficient of …
Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu
Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu
Turkish Journal of Chemistry
The synthesis of a new symmetric disazo direct dye containing the non--carcinogenic 4,4'-diaminobenzanilide as the middle component and salicylic acid as the coupling component is presented. The synthesized dye is an analog of the benzidine based dye C. I. Direct Yellow 1 (C. I. 22,250) and was analyzed by thin layer chromatography (TLC), electronic spectra (VIS) and mass spectroscopy (FAB-MS). The coloristic and fastness properties of the synthesized dye were determined and compared with those of C. I. Direct Yellow 1. The toxicities of the dye and of its precursors were evaluated by biological tests, using the process of metamorphosis …
Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal
Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal
Turkish Journal of Chemistry
The synthesis, characterisation and partial hydrolysis of poly(tert-butylmethacrylate), (PTBMA), and the electrorheological (ER) properties of its suspensions were investigated. The polymer was synthesised by radical polymerisation and partially hydrolysed by para-toluenesulphonic acid monohydrate (PTSA.H_2O), and then converted to a lithium salt (PTBMA-Li) by washing with a LiOH_{(aq)} solution. From particle size measurements, the average particle size of PTBMA-Li was determined to be 74 \mu m. Colloidal suspensions of ionomer were prepared in various insulating oils [silicone oil (SO), mineral oil (MO), threeoctylthreemellitate (TOTM) and dioctylphatalete (DOP)] at a series of concentrations (c = 5-33 m/m, %). The sedimentation stabilities of …
Separation Of Abscisic Acid, Indole-3-Acetic Acid, Gibberellic Acid In 99 R (Vitis Berlandieri X Vitis Rupestris) And Rose Oil (Rosa Damascena Mill.) By Reversed Phase Liquid Chromatography, Mustafa Kelen, Ebru Çubuk Demi̇ralay, Songül Şen, Güleren Özkan Alsancak
Separation Of Abscisic Acid, Indole-3-Acetic Acid, Gibberellic Acid In 99 R (Vitis Berlandieri X Vitis Rupestris) And Rose Oil (Rosa Damascena Mill.) By Reversed Phase Liquid Chromatography, Mustafa Kelen, Ebru Çubuk Demi̇ralay, Songül Şen, Güleren Özkan Alsancak
Turkish Journal of Chemistry
Plant hormones, specialized chemical substances produced by plants, are the main internal factors controlling growth and development. In this study the pH and polarity of the mobile phase were taken into consideration to optimize the mobile phase for the chromatographic separation of 3 important plant hormones: abscisic acid (ABA), indole-3-acetic acid (IAA) and gibberellic acid (GA_3). pK_a values of ABA, IAA and GA_3 were determined using retention factors. These 3 hormones were extracted from 99 R (Vitis berlandieri x Vitis rupestris) and rose oil (Rosa damascena Mill.) and the chromatographic method developed was used for the separation of these hormones.
Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin
Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin
Turkish Journal of Chemistry
A sensitive, selective and rapid method for the determination of cobalt based on the rapid reaction of cobalt(II) with QADEAA and the solid phase extraction of the Co(II)-QADEAA chelate with C_{18} membrane disks was developed. In the presence of pH = 5.5 buffer solution and cetyl trimethylammonium bromide (CTMAB) medium, QADEAA reacts with cobalt to form a violet complex with a molar ratio of 1:2 (cobalt to QADEAA). This chelate was enriched by the solid phase extraction with C_{18} membrane disks. An enrichment factor of 50 was obtained by elution of the chelate from the disks with a minimal amount …
Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Turkish Journal of Chemistry
From the aerial parts of Verbascum salviifolium Boiss., 2 neolignan glucosides, dehydrodiconiferyl alcohol-9'-O-\beta -D-glucopyranoside (1) and dehydrodiconiferyl alcohol-9-O-\beta- D-glucopyranoside (2), along with 5 phenylethanoid glycosides, acteoside (= verbascoside) (3), \beta -hydroxyacteoside (4), forsythoside B (5), angoroside A (6) and martynoside (7), were isolated. The structure elucidation of the isolated compounds was established on the basis of spectroscopic evidence. Compounds 1-7 demonstrated scavenging properties toward the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in TLC autographic and spectroscopic assays.
Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan
Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan
Turkish Journal of Chemistry
A set of 14 mono-organotin(IV) derivatives of general formulae n-BuSnClL_2 and n-BuSnL_3, where `L' are various non-steroidal anti-inflammatory drugs (NSAIDs), were synthesized and structurally characterized by vibrational, ^1H, ^{13}C and ^{119}Sn spectroscopies and mass spectrometry to propose their structure. Biological activity data (antibacterial, antifungal and cytotoxicity) of the synthesized complexes were compared with the precursors to establish the significance of the complexes.
Crystal And Molecular Structure Of The Yellow Form Of Chloro(2,2':6',2''-Terpyridine)Platinum (Ii)Chloride Dihydrate, [Pt(Terpy)Cl]Cl · 2h_2o, Abdurrahman Şengül
Crystal And Molecular Structure Of The Yellow Form Of Chloro(2,2':6',2''-Terpyridine)Platinum (Ii)Chloride Dihydrate, [Pt(Terpy)Cl]Cl · 2h_2o, Abdurrahman Şengül
Turkish Journal of Chemistry
The synthesis, characterization, and X-ray crystal structure of the yellow dimorph, [Pt(terpy)Cl]Cl · 2H_2O, are reported. The yellow acicular crystals are monoclinic: space group P2_1/n, a = 6.908(3) Å, b = 17.06700(11) Å, c = 13. 8390(10) Å, \beta = 98.607(4)°, and D_{calc} = 2.204 Mg m^{-3} for Z = 4. The cation consists of platinum coordinated to tridentate terpyridine ligand and to chloride ion. The coordination geometry is essentially square-planar with distortions arising from the constraints of the terpyridine ligand. Bond distances are within the acceptable limits of predicted values. The cations stack in a head-to-tail orientation with an …
Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Turkish Journal of Chemistry
A series of 4-(1-naphthylidenamino)-1,2,4-triazol-5-one derivatives (3a-e) were synthesized by condensation of corresponding 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 1-naphthaldehyde. Acetylation and alkylation of these compounds gave 4a-e and 5a-e, respectively. Sodium borohydride reduction of 1-naphthylidenamino derivatives afforded naphthylmethylamino derivatives, which were subsequently acetylated. Depending on the duration of the acetylation, mono or bis acetamide derivatives were obtained. The in vitro antitumor activities of some selected compounds were screened and compounds 3e, 5c, 6e and 9c} were found to be active.
Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot
Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot
Turkish Journal of Chemistry
The paper reports the synthesis of crystalline oxovanadium(IV), VO^{2+}, complexes of thiosemicarbazones, i.e. 4[N-(4'-nitrobenzalidene)amino]antipyrine thiosemicarbazone (4'-NO_2BAAPTS) and 4[N-(furan-2'-aldimine)amino]antipyrine thiosemicarbazone (FFAAPTS) with general composition VOX_2L (X = Cl, Br, I, NO_3 or NCS) and VO(ClO_4)_2(L)H_2O (L = 4'-NO_2BAAPTS or FFAAPTS). All the complexes were characterized by elemental analyses, molar mass, molar conductance, magnetic susceptibility, infrared and electronic spectra. In all the complexes, both the thiosemicarbazones behave as neutral tridentate (N, N, S) ligands. The thermal properties of the representative complexes are also reported. The most probable geometry of the complexes is proposed.
An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül
An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül
Turkish Journal of Chemistry
2,2'-Bipyridyl-3,3'-dicarboxylic acid (H_2BDC) spontaneously resolves on crystallization from water, giving monohydrated crystals of the space group P2_12_12_1. In any individual crystal, all the atropisomeric-skewed molecules are of one hand; however, on dissolution in water, optical activity is lost. Strong hydrogen bonding leads to a helical structure, via O--H ... N links, and 3 further strong bonds between water and carboxylate groups produce a framework structure. The pK_a values measured for H_2BDC (3.18 \pm 0.04 and 4.59 \pm 0.02 at 20 \pm 1 °C, in dilute aqueous solution) agree with the zwitterionic form. The reaction of H_2BDC with potassium tetrachloroplatinate(II) in …
Bromination Of Tricyclo[7.2.1.0^{2,7}]Dodeca-2,4,6,10-Tetraene Derivatives: Electronic And Neighboring Group Effects On Bromination, Ari̇f Daştan
Turkish Journal of Chemistry
The bromination reaction of tricyclo[7.2.1.0^{2,7}]dodeca-2,4,6,10-tetraene derivatives was studied. The bromination of 9 gave only rearranged products 12 and 13, while the bromination of 8 with molecular bromine formed both rearranged 12 and non-rearranged products 15 and 16. The possible role of a substituent in the rearrangements was examined. All compounds were characterized properly, in particular by NMR spectra and chemical transformation.
X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad
X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad
Turkish Journal of Chemistry
Poly (methyl methacrylate) -- PMMA -- and poly (methacryloyl chloride) -- PMACl -- were synthesized by free radical solution polymerization. The thermal stabilities of these polymers were determined with the help of thermogravimetry and differential thermal analysis. The structural changes in these materials at different temperatures (90, 140, 220 and 410 °C) were studied by X-ray diffraction. These studies indicate that PMACl is less amorphous than PMMA due to the presence of bulky chloride groups
External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel
External Mass Transfer Studies During The Adsorptions Of Some Dyestuffs And P-Nitrophenol Onto Chitosan From Aqueous Solution, İlhan Uzun, Fuat Güzel
Turkish Journal of Chemistry
The effect of temperature on the adsorptions of some dyestuffs [orange II (O-II), crystal violet (CV) and reactive blue 5 (RB5)] and an ideal adsorbate p-nitrophenol (PNP) by chitosan (Sigma C 3646) from aqueous solution was investigated. The experimental data related to adsorption isotherms were applied to linear forms of the equations that they fitted, and isotherm constants were calculated. Since the isotherm curves obtained for the adsorptions of O-II and CV by chitosan fitted the Langmuir adsorption isotherm, the Langmuir constants (q_m and b) related to the adsorption isotherms of these dyestuffs together with their kinetical data at different …
Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir
Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir
Turkish Journal of Chemistry
The lignan content of Linum olympicum Boiss. was investigated by HPLC and GC-MS in comparison with standards, and 2 phenylpropanoid glycosides, syringin (1) and coniferin (2), were isolated from the aerial parts. Identification of the 2 compounds was achieved by comparison with standards using TLC and HPLC and the structures of the isolated compounds were established by UV and ^1H-NMR analysis.
Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan
Main Flavonoids Of Tilia Argentea Desf. Ex Dc. Leaves, Gülnur Toker, Merve Memi̇şoğlu, Erdem Yeşi̇lada, Mustafa Aslan
Turkish Journal of Chemistry
No abstract provided.
Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara
Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara
Turkish Journal of Chemistry
This study deals with the isolation of a new acylated 5,6,7,3',4'-pentahydroxy-flavone glycoside (1) and 3 known allose-containing acylated flavone glycosides (2-4) as well as a known flavone aglycone (5) from the aerial parts of Veronica pectinata var. glandulosa and V. persica. The structures of the isolated compounds were determined to be 3' -hydroxy-4'-O-methylscutellarein-7-O-[2''-O-\alpha -L-rhamnopyranosyl-3''-O-(6''''-O-acetyl-\beta -D-glucopyranosyl)]-\beta- D-glucopyranoside, named sarachoside (1), 4' -O-methylisoscutellarein-7-O-2''- O-(6''' -O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (2), isos\-cutellarein-7-O-2''-O-(6'''-O-acetyl-\beta-D-allopyranosyl)-\beta- D-glucopyranoside (3), 3'-hydroxy-4'-O-methy\-lisoscutellarein-7-O-2'' -O-(6'''-O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (4) and 5,4'-dihydroxy-6,7,3' -trimethoxyflavone, named circilineol (5) by extensive 1-D and 2D-NMR spectroscopy. Sarachoside (1) exhibited potent radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.
Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara
Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara
Turkish Journal of Chemistry
Three rare methoxyflavonoids, rhamnazin 3-O-rutinoside (1), rhamnocitrin 3-O-rutinoside (2) and isorhamnetin 3-O-rutinoside (3), were isolated from the methanolic extract of Pinaropappus roseus together with 2 well-known flavonoids, quercetin 3-O-rutinoside (=rutin) (4) and kaempferol 3-O-rutinoside (5). The structures of the isolated compounds were elucidated on the basis of UV, 1D and 2D NMR and FAB-Mass spectral analysis. Free radical scavenging activities of the isolated compounds were also demonstrated. This is the first report on the chemical composition of the genus Pinaropappus.
Solution Of The Schrödinger Equation With One And Two Timensional Double-Well Potentials, Ramazan Koç, Derya Haydargi̇l
Solution Of The Schrödinger Equation With One And Two Timensional Double-Well Potentials, Ramazan Koç, Derya Haydargi̇l
Turkish Journal of Physics
The Schrödinger equation with one and two dimensional potentials are solved in the framework of the sl_2(R) Lie algebra. Eigenfunctions of the Schrödinger equation for various asymmetric double-well potentials have been determined and the eigenstates are expressed in terms of the orthogonal polynomials. The solution of the double-well potential in two dimension have been analyzed.
On Electron Mobility In A Rectangular Quantum Wire Due To Alloy Disorder, Guseyn Behbudoglu Ibragimov
On Electron Mobility In A Rectangular Quantum Wire Due To Alloy Disorder, Guseyn Behbudoglu Ibragimov
Turkish Journal of Physics
Analytic expressions are derived to describe the electron mobility and relaxation rate in the rectangular quantum wire experiencing scattering due to alloy disorder. The dependence of electron mobility on the temperature and transverse dimension is numerically evaluated and it is found that the mobility increases continuously with temperature, because there is no new intersubband scattering with increase in temperature. It is shown that the alternating increase/decrease in the mobility---depending on the transverse dimension of the quantum wire---occurs due to intersubband scattering. It is found that the mobility in a quantum wire is significantly greater than mobility in a quantum well.
Areal Distribution And Bulk Rock Density Variations Of The Welded İncesu Ignimbrite, Central Anatolia, Turkey, Ulrike Mues-Schumcher, Rolf Schumacher, Lothar Georg Viereck-Götte, Petra Lepetit
Areal Distribution And Bulk Rock Density Variations Of The Welded İncesu Ignimbrite, Central Anatolia, Turkey, Ulrike Mues-Schumcher, Rolf Schumacher, Lothar Georg Viereck-Götte, Petra Lepetit
Turkish Journal of Earth Sciences
The 2.8 Ma İncesu ignimbrite is one of the most densely welded ignimbrites of the Cappadocian Volcanic Province. Estimates of areal extent and volume reveal at least 7,760 km^2 and 38 km^3 of erupted magma. The source area can be located beneath the northeastern flanks of the Erciyes Dağ-Koçdağ stratovolcano. Today, the ignimbrite typically forms relatively small plateaus or isolated remnants and caps on hill tops. Field characteristics of the deposit include a local dark-brown or black basal vitrophyre and horizontally zoned changes in colour which correspond to changes in modal composition. Upwardly increasing amounts of lithic fragments and pumice …
The Problem Of The Core-Cover Boundary Of The Menderes Massif And An Emplacement Mechanism For Regionally Extensive Gneissic Granites, Western Anatolia (Turkey), Burhan Erdoğan, Tali̇p Güngör
The Problem Of The Core-Cover Boundary Of The Menderes Massif And An Emplacement Mechanism For Regionally Extensive Gneissic Granites, Western Anatolia (Turkey), Burhan Erdoğan, Tali̇p Güngör
Turkish Journal of Earth Sciences
In previous studies, the stratigraphy of the Menderes Massif was divided into a Precambrian core and Mesozoic cover associations, the core consisting of gneissic granites and high-grade schists and the cover of mica schists and platform-type marbles. It has also been proposed that the two associations are separated by an unconformity although nowhere is this relation clearly observed. In this study, the Bafa and Kavaklıdere areas in the southern part of the massif have been examined. In the Bafa area, Mesozoic mica schists with marble lenses occur in the lowermost parts of the sequence and are overlain, along a gradational …
Geochemistry And Geochronology Of Orthogneisses In The Derbent (Alaşehir) Area, Eastern Part Of The Ödemiş-Kiraz Submassif, Menderes Massif: Pan-African Magmatic Activity, Ersi̇n Koralay, O. Özcan Dora, Fukun Chen, Muharrem Satir, Osman Candan
Geochemistry And Geochronology Of Orthogneisses In The Derbent (Alaşehir) Area, Eastern Part Of The Ödemiş-Kiraz Submassif, Menderes Massif: Pan-African Magmatic Activity, Ersi̇n Koralay, O. Özcan Dora, Fukun Chen, Muharrem Satir, Osman Candan
Turkish Journal of Earth Sciences
Pan-African basement rocks and the Palaeozoic cover series of the Menderes Massif are exposed around Derbent (Alaşehir) in the eastern part of the Ödemiş-Kiraz submassif. Garnet-mica schists of the Pan-African basement are intruded by the protoliths of orthogneisses and Triassic leucocratic orthogneisses. This study focuses on the geochronology and geochemistry of orthogneisses related to the Pan-African evolution of the Menderes Massif in latest Proterozoic time. Geochemical data suggest that the orthogneisses were derived from S-type, peraluminous, syn- to post-collisional granitoids of calc-alkaline affinity. Zircon grains from the orthogneisses, which are euhedral with typical igneous morphologies, were dated by the Pb-Pb …
Ac Conductivity And Dielectric Study Of Chalcogenide Glasses Of Se-Te-Ge System, Fathy Salman
Ac Conductivity And Dielectric Study Of Chalcogenide Glasses Of Se-Te-Ge System, Fathy Salman
Turkish Journal of Physics
The ac conductivity and dielectric properties of glassy system Se_{x}Te_{79 - x}Ge_{21}, with x = 11, 14, 17 at.%, has been studied at temperatures 300 to 450 K and over a wide range of frequencies (50 Hz to 500 kHz). Experimental results indicate that the ac conductivity and the dielectric constants depend on temperature, frequency and Se content. The conductivity as a function of frequency exhibited two components: dc conductivity \sigma _{dc}, and ac conductivity \sigma _{ac}, where \sigma _{ac} \sim \omega ^{s}. The mechanism of ac conductivity can be reasonably interpreted in terms of the correlated barrier hopping model …
Raman Scattering In Layered Cdingas_4, Aydin Kulibekov
Raman Scattering In Layered Cdingas_4, Aydin Kulibekov
Turkish Journal of Physics
Raman scattering spectra of CdInGaS_4 crystals grown by the chemical transport method were measured at room and liquid-nitrogen temperatures. Band pairs at 29-38, 43-48 and 60-65 cm^{-1} are reported for the first time. The origin of these bands is attributed to the Davydov doublets, arising due to a small interlayer interaction. Seventeen bands observed in the Raman spectra are assigned to normal modes on the basis of the C_{3v}^1 space group. This modification contains two layers per unit cell and do not have inversion symmetry. It is shown that the crystals grown from the vapor phase and by the Bridgman …
The Hypervirial-Padé Summation Method Applied To The Anharmonic Oscillator, Altuğ Arda
The Hypervirial-Padé Summation Method Applied To The Anharmonic Oscillator, Altuğ Arda
Turkish Journal of Physics
The energy eigenvalues of the anharmonic oscillator characterized by the cubic potential for various eigenstates are determined within the framework of the hypervirial-Padé summation method. For this purpose the E[3, 3] and E[3, 4] Padé approximants are formed to the energy perturbation series and given the energy eigenvalues up to fourth order in terms of the anharmonicity parameter \lambda.
Effect Of Radiation On The Persistent Length Of A Chain, B. L. Oksengendler, Ni̇gora Turaeva, I. N. Ruban, S. Sh. Rashidova
Effect Of Radiation On The Persistent Length Of A Chain, B. L. Oksengendler, Ni̇gora Turaeva, I. N. Ruban, S. Sh. Rashidova
Turkish Journal of Chemistry
The effect of radiation on the persistent length of a chain in a water solution of polymer is considered in the work. This effect is suggested to be related to the breaking of the hydrogen bonds in hydrate layers around the chain. The kinetic equation of the breakage of the hydrogen bonds is defined and the stationary solution is found with the help of the equation. The expression of average value of the persistent length of the chain at a fixed average number of broken bonds is determined by means of the Poisson distribution. We found that the persistent length …