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Full-Text Articles in Physical Sciences and Mathematics

Trace Element Accumulation In Selected Bioindicators Exposed To Emissions Along The Industrial Facilities Of Danube Lowland, Heide Spiegel Jan 2002

Trace Element Accumulation In Selected Bioindicators Exposed To Emissions Along The Industrial Facilities Of Danube Lowland, Heide Spiegel

Turkish Journal of Chemistry

The scope of this study was to investigate the effects of the atmospheric emissions of two significant industrial centres of the Danube Lowland: the Schwechat and Slovnaft refineries. In this connection the environmental pollution of emission zones by heavy metals on the base of selected bioindicators (soil, lucerne, wheat, earthworms) should be evaluated. The phenomenon of the atmospheric impact of heavy metal aerosols on the food chain and substance transfer for the model studied (soil - plants - terrestrial invertebrates) was quantified by transfer (bioaccumulation) factors. Due to the orographic depression between the Eastern Alps and Western Carpathian Mountains and …


Conformational Analysis Of Pol-Rfamide Ii (Glu}^{1}-Trp^{2}-Leu^{3}-Lys^{4}-Gly^{5}-Arg^{6}-Phe^{7}-Nh_{2}) Heptapeptide, Lütfü Demi̇r, Niftali Mihrali Godjaev Jan 2002

Conformational Analysis Of Pol-Rfamide Ii (Glu}^{1}-Trp^{2}-Leu^{3}-Lys^{4}-Gly^{5}-Arg^{6}-Phe^{7}-Nh_{2}) Heptapeptide, Lütfü Demi̇r, Niftali Mihrali Godjaev

Turkish Journal of Chemistry

The geometrical structure of the sea anemone and sea pansies neuropeptide Pol-RFamide II Glu^{1}-Trp^{2}-Leu^{3}-Lys^{4}-Gly^{5}-Arg^{6}-Phe^{7}-NH_{2} was carried out by molecular mechanics (MM). The linkage bonds are characterised by the torsional angles \phi, \psi and \omega and the side groups characterised by the torsional angles \chi_{1}, \chi_{2}, \chi_{3},... subsequently. The energy-map for each monopeptide of the Pol-RFamide II was drawn in the range of -180° to 180° with increments of 20°. Conformation facilities for monopeptides were decided from these maps. These results were used in the analysis of the dipeptide Glu^{1}-Trp^{2}. Then, the Glu^{1}-Trp^{2}-Leu^{3} tripeptide was examined by using the calculated results …


Acid-Base Equilibria Of Some N-Substituted Thiophene-2-Carboxamidoximes In Non-Aqueous Media, Nedi̇me Dürüst, Yaşar Dürüst, İlknur Meri̇ç Jan 2002

Acid-Base Equilibria Of Some N-Substituted Thiophene-2-Carboxamidoximes In Non-Aqueous Media, Nedi̇me Dürüst, Yaşar Dürüst, İlknur Meri̇ç

Turkish Journal of Chemistry

The protonation constants of the amino nitrogens of some N-substituted thiophene-2-carboxamidoximes have been determined in acetic acid by means of potentiometric titration with perchloric acid. pK_{a} values of the title compounds were interpreted on the basis of structural effects due to the substituents and the main skeleton.


Spectrophotometric Determination Of Mexiletine Hydrochloride In Capsules Using Bromothymol Blue, Zeynep Aydoğmuş, S. Müge Çeti̇n, Sedat Tosunoğlu Jan 2002

Spectrophotometric Determination Of Mexiletine Hydrochloride In Capsules Using Bromothymol Blue, Zeynep Aydoğmuş, S. Müge Çeti̇n, Sedat Tosunoğlu

Turkish Journal of Chemistry

A new spectrophotometric method based on the formation of an ion-pair using bromothymol blue as ion-pair complexing reagent was developed for the determination of mexiletine hydrochloride in capsules. The ion-pair formed was highly coloured and easily extracted with dichloromethane. The calibration curve was linear over the concentration range 1.08--10.8 \mu g.ml^{-1} at \lambda_{max} = 408 nm (r = 0.9999). The results obtained from the developed method were compared statistically with those obtained by the British Pharmacopeia method.


The Protonation Constants Of Some Aliphatic Alkylamines In Ethanol-Water Mixtures, Esma Kiliç, Gülteki̇n Gökçe, Esi̇n Canel Jan 2002

The Protonation Constants Of Some Aliphatic Alkylamines In Ethanol-Water Mixtures, Esma Kiliç, Gülteki̇n Gökçe, Esi̇n Canel

Turkish Journal of Chemistry

Protonation constants of methyl-, ethyl-, propyl- and butylamines Were determined potentiometrically using an electrode system calibrated in concentration units of hydrogen ion in ethanol-water mixtures (10\% -80\% ethanol, v/v) at an ionic strength of 0.1 and at 25°C. The trend in the values of protonation constants of these aliphatic amines was explained in terms of the number of alkyl groups and solvent composition. The basicity orders were found to be NH_{3} < R_{3}N < RNH_{2} < R_{2}NH (R:-CH_{3}, -C_{2}H_{5}, -n-C_{3}H_{7} and --n-C_{4}H_{9}) in all the solvent mixtures studied.


Swelling Of Superabsorbent Acrylamide/Sodium Acrylate Hydrogels Prepared Using Multifunctional Crosslinkers, Erdener Karadağ, Dursun Saraydin Jan 2002

Swelling Of Superabsorbent Acrylamide/Sodium Acrylate Hydrogels Prepared Using Multifunctional Crosslinkers, Erdener Karadağ, Dursun Saraydin

Turkish Journal of Chemistry

Superwaterabsorbent acrylamide-sodium acrylate hydrogels were Prepared by free radical polymerization in aqueous solutions of acrylamide and of acrylamide with sodium acrylate as comonomer. For each copolymerization, nine different compositions were used and in all systems a concentration of a multifunctional crosslinker such as trimethylolpropane triacrylate, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate and N,N'-methylenebisacrylamide was employed. As a result of dynamic swelling tests, the influence of crosslinkers and the relative content of sodium acrylate on the swelling properties, the initial swelling rate and the swelling rate constant, swelling exponent, swelling coefficients and diffusional behaviour of water in the hydrogel systems were examined. …


Modeling Of Taqi Endonuclease Purification By Hplc, Mehmet Düzenli̇, Kutlu Ö. Ülgen Jan 2002

Modeling Of Taqi Endonuclease Purification By Hplc, Mehmet Düzenli̇, Kutlu Ö. Ülgen

Turkish Journal of Chemistry

The present work is based on the previously reported purification study of TaqI endonuclease^{5} and aimed to simulate the experimentally obtained chromatograms in order to reduce the time and cost in the design, optimization and scaling up of purification processes. Three different models depending on equilibrium, rate and plate theories are used in the mathematical description of experimental elution profiles and the solutions of the model equations are compared. The equilibrium-dispersive theory provides excellent results in predicting the experimental chromatograms. It is thus recognized that band dispersion takes place in the column through axial dispersion and nonequilibrium effects. The user-friendly …


The Selective Protection And Deprotection Of Ambident Nucleophiles With Parent And Substituted Triarylmethyls, İbrahi̇m Demi̇rtaş, Bülent Büyükkidan, Mahfuz Elmastaş Jan 2002

The Selective Protection And Deprotection Of Ambident Nucleophiles With Parent And Substituted Triarylmethyls, İbrahi̇m Demi̇rtaş, Bülent Büyükkidan, Mahfuz Elmastaş

Turkish Journal of Chemistry

N-triphenylmethyl and N-4,4'-dimethoxytriphenylmethyl of o-aminophenol, m-aminophenol, and p-aminophenol compounds were easily prepared from triphenylmethyl chloride and 4,4'-dimethoxytriphenyl- methyl chloride. S-triphenylmethyl-2-mercapto ethanol was also selectively synthesized using the triphenylmethyl chloride and 2-mercapto ethanol. The reactivity of nitrogen and sulfur versus oxygen in the protection reactions was compared. In principle, the protection of aminophenols and 2-mercapto ethanol with triarylmethyls (trityls) may take place on the oxygen. However, in this framework, we discuss the different reactivities of oxygen, nitrogen and sulfur towards triphenylmethyl chloride (TrCl) and 4,4'-dimethoxytriphenylmethyl chloride (DMTrCl) and find that nitrogen and sulfur are more reactive than oxygen.


Synthesis Of Novel Acidic Mono Azo Dyes And An Investigation Of Their Use In The Textile Industry, Emel Yildiz, Hami̇t Boztepe Jan 2002

Synthesis Of Novel Acidic Mono Azo Dyes And An Investigation Of Their Use In The Textile Industry, Emel Yildiz, Hami̇t Boztepe

Turkish Journal of Chemistry

1,2-hydroxo phenyl azo,8-amino naphthalene, 3,6-disulfonic acid Mono sodium salt (HFANS) and its metal complex with chromium (III) salt (ligand metal ratio 1:1) were synthesized as H-acid derivatives. Having an acidic character these dyes are used for dyeing polyamide and protein fibers. Their properties such as dyeing, wash fastness and color classification were investigated according to international standard methods.


Anodic Behavior Of Tungsten In H_{3}Po_{4}-K_{2}So_{4}-H_{2}So_{4}/Koh Solutions, Mustafa Anik Jan 2002

Anodic Behavior Of Tungsten In H_{3}Po_{4}-K_{2}So_{4}-H_{2}So_{4}/Koh Solutions, Mustafa Anik

Turkish Journal of Chemistry

Potentiodynamic and potentiostatic polarizations were used to study the effect of pH on the anodic reaction characteristics of tungsten (W) in a very broad pH range (0.4-13). The open circuit potential was observed to decrease with a constant slope of 58 mV/pH, as pH increased. The oxide phase of W showed typical amphoteric surface behavior in the acidic regime. The oxide dissolution went through a minimum at pH 2.5, which was identified as the point of zero charge (pzc) of W--oxide. The oxide dissolution below the pzc was H^{+} -assisted and above the pzc was OH^{-}-assisted. At around the pzc …


Bromination Of Benzonorbornadiene Using A Mixture Of Sodium Bromide And Sodium Perborate At High Temperatures, Erdal Şenocak, Yavuz Taşkesenli̇gi̇l, Ferhan Tümer Jan 2002

Bromination Of Benzonorbornadiene Using A Mixture Of Sodium Bromide And Sodium Perborate At High Temperatures, Erdal Şenocak, Yavuz Taşkesenli̇gi̇l, Ferhan Tümer

Turkish Journal of Chemistry

Bromination of benzonorbornadiene (1) with sodium bromide in the presence of sodium perborate at room temperature gave only one product, the dibromide 2 produced via Wagner-Meerwein rearrangement. However, at high temperatures, bromination resulted predominantly in the formation of rearranged solvolytic products whose formation mechanisms are discussed.


New Triterpenic Saponins From Cephalaria Transsylvanica, Süheyla Kirmizigül, Hüseyi̇n Anil Jan 2002

New Triterpenic Saponins From Cephalaria Transsylvanica, Süheyla Kirmizigül, Hüseyi̇n Anil

Turkish Journal of Chemistry

Three new triterpenic saponins, 3-O-[\beta-D-xylopyranosyl (1 \to 4)-\beta-D-glucopyranosyl (1 \to 4)-\beta-D-glucopyranosyl (1 \to 3)-\alpha-L-rhamnopyranosyl (1 \to 4)-\beta-D-xylopyranosyl] hederagenin 28-O-[\beta-D-glucopy\-ranosyl (1 \to 4)-\beta-D-glucopyranosyl] ester (1), 3-O-[\beta-D-glucopyranosyl (1 \to 4)-\beta-D-glucopyranosyl (1 \to 3)-\alpha-L-rhamnopyranosyl (1 \to 4)-\beta-D-xylopyranosyl] hederagenin 28-O-[\beta -D-glucopyranosyl] ester (2) and 3-O-[\beta-D-glucopyranosyl (1 \to 3)-\alpha-L-rhamnopyranosyl (1 \to 4)-\beta-D-xylopyranosyl] hederagenin(3) were isolated from Cephalaria transsylvanica. After cleavage of the ester-glycosidic linkage of the bisdesmosidic compounds, two new prosapogenins, 3-O-[\beta-D-xylopyranosyl (1 \to 4)-\beta-D-glucpyranosyl (1 \to 4)-\beta-D-glucopyranosyl (1 \to 3)-\alpha-L-rhamnopyranosyl (1 \to 4)-\beta-D-xylopyranosyl] hederagenin (4) and 3-O-[\beta-D-glucopyranosyl (1 \to 4)- \beta-D-glucopyranosyl (1 \to 3)-\alpha-L-rhamnopyranosyl (1 \to 4)-\beta-D-xylopyranosyl] hederagenin (5) were also isolated. The structures …


Pyridine And Benzene Templated Potential Peptidomimetics, Kadi̇r Dabak Jan 2002

Pyridine And Benzene Templated Potential Peptidomimetics, Kadi̇r Dabak

Turkish Journal of Chemistry

This study provides a new approach for the synthesis of pyridine and benzene templated potential peptidomimetics. By the attachment of various amino acid side chains in different combinations on the pyridine template at the 2- and 3- positions and on the benzene core at 1,2,4 positions, different peptidomimetics may be obtained. Arg-10, Leu-11 and Tyr-13 amino acid side chain mimics and their precursors were attached to the pyridine and benzene core with a special arrangement to produce potential peptidomimetics of omega-conotoxin MVIIA.


Metallation Of Mesitylene By Organolithium Compounds In The Presence Of Lithium Polyether Alkoxides, Tuba Kayhan, Ni̇han Nugay, Turgut Nugay Jan 2002

Metallation Of Mesitylene By Organolithium Compounds In The Presence Of Lithium Polyether Alkoxides, Tuba Kayhan, Ni̇han Nugay, Turgut Nugay

Turkish Journal of Chemistry

The catalytic effect of polyether alkoxides (PEAs) on the activity Of organolithium compounds as a metallating agent studied. The sites of metallation as mono, di, tri, and gem metallation at three different benzylic positions were investigated in terms of relative yield by using gas chromatography-mass spectroscopy (GC-MS couple) techniques. The yield of the trimetallated (1,3,5-metallated) mesitylene was optimized by improving the metallation conditions. Special attention was paid to the effect of metal type, alkoxide structure, solvent polarity, temperature and also relative mole ratios of was reactants such as alkoxide to mesitylene and n-butyllithium to mesitylene on metallation reactions. It was …


Stimulated Polarization In \Bf Linbo_{3} And \Bf Ba_{2}Nanb_{5}O_{15} Crystals, Süleyman Çabuk, Amirullah Mamedov Jan 2002

Stimulated Polarization In \Bf Linbo_{3} And \Bf Ba_{2}Nanb_{5}O_{15} Crystals, Süleyman Çabuk, Amirullah Mamedov

Turkish Journal of Physics

Thermally Stimulated Conductivity (TSC) and thermoelectret state in LiNbO_{3} and Ba_{2}NaNb_{5}O_{15} were measured as a function of temperature and time in dark and under UV excitation at liquid nitrogen temperature. Effect of polarization and the other external influences on thermoelectret were investigated. The thermal activation energy levels of traps were determined from TSC measurements as well as parameters (electric field, temperature, etc.) which are necessary for characterizing thermoelectrets were obtained.


The Ibm-2 Study For Some Even - Even Platinum Isotopes, Mehmet Baylan, Mehmet Altay Atlihan Jan 2002

The Ibm-2 Study For Some Even - Even Platinum Isotopes, Mehmet Baylan, Mehmet Altay Atlihan

Turkish Journal of Physics

The structure of some even -- even Pt isotopes have been studied within the framework of the interacting boson model. The B(E2), B(M1) and Q(I) values of the above nuclei have been calculated. The numerical results obtained for Pt have been compared with the previous experimental and theoretical values obtained on the basis of the interacting boson model (IBA-2).


Justification Of Spherical Approximations Using Degree Of Linear Polarization Of Hot Electron Luminescence From Gaas Crystal, Mohammad Naeem Khalid, Shazia Yasin Jan 2002

Justification Of Spherical Approximations Using Degree Of Linear Polarization Of Hot Electron Luminescence From Gaas Crystal, Mohammad Naeem Khalid, Shazia Yasin

Turkish Journal of Physics

The anisotropic momentum distribution of photoexcited hot electrons on recombination with holes at the acceptor level produces linearly polarized luminescence. It is found that the degree of linear polarization (DoLP) of the luminescence over the whole width of the first heavy hole peak (0HH) is not constant. Calculations within the spherical approximation show that in bulk GaAs the DoLP over the 0HH peak should vary from zero, at the low energy side, to its maximum value (0.33), at the high energy side of the 0HH peak, for the electric vector of excitation \hat {\boldsymbol e}\vert \vert [110] excitation geometry and …


The Single Step Vmhnc Calculations For Liquid Alkali Metals In The Inverse Problem, Serap Şentürk Dalgiç, Seyfetti̇n Dalgiç, Mehmet Tomak Jan 2002

The Single Step Vmhnc Calculations For Liquid Alkali Metals In The Inverse Problem, Serap Şentürk Dalgiç, Seyfetti̇n Dalgiç, Mehmet Tomak

Turkish Journal of Physics

An effective pair potential \phi (r) for liquid alkali metals close totheir melting points is extracted from an experimental structure factor using the inverse method based on the variational modified hypernetted-chain integral equation theory of liquids (VMHNC). The first order pair potential according to the procedure suggested by de Angelis and March is also presented for comparison. It has been found that the inverted pair potentials of liquid alkali metals scale well.


Formation Energy In Al-Mg Alloy By Positron Annihilation Lifetime Technique (Palt), Mamduh Abedl-Rahman, Emad A. Badawi, Essmat Mahmoud Hassan, Gamal Yahya Jan 2002

Formation Energy In Al-Mg Alloy By Positron Annihilation Lifetime Technique (Palt), Mamduh Abedl-Rahman, Emad A. Badawi, Essmat Mahmoud Hassan, Gamal Yahya

Turkish Journal of Physics

The propose of the present work is to study the interaction of positrons with quenched-in defects and clustered atoms to estimate formation enthalpy in series 50xx of commercial Al-Mg alloys, namely, 5049, 5051,5052 and 5083 at various concentrations: 1.9, 2.09, 2.46 and 4.44 wt % of Mg, respectively. Typically additional impurities were mainly Si, Fe, Cu, Cr and Ti. The monvacancy formation energy of Al-Mg alloys was measured from a trapping model analysis of the T-dependence of the positron lifetime.


Defect Structure Of Glow Peak 1 In Lif:Mg,Ti (Tld-100), A. Necmeddi̇n Yazici Jan 2002

Defect Structure Of Glow Peak 1 In Lif:Mg,Ti (Tld-100), A. Necmeddi̇n Yazici

Turkish Journal of Physics

The possible defect structure of peak 1 of LiF:Mg,Ti (TLD-100) was studied in the present work after different pre-irradiation heat treatments between 80°C and 150°C using the computer glow curve deconvolution (CGCD) method. It was shown that the defect structure of peak 1 is based on colloid centers, Ti^{+4}-3O_{2}^{-}-mixed centers and U_{1}-centers.


Measurement Of Photon-Induced K X-Rays Production Cross Sections For Elements With 62 \Le Z \Le 74, Sabri̇ye Seven Jan 2002

Measurement Of Photon-Induced K X-Rays Production Cross Sections For Elements With 62 \Le Z \Le 74, Sabri̇ye Seven

Turkish Journal of Physics

X-ray production cross sections of K\alpha_{1}, K\alpha_{2}, K\beta'_{1} (= K\beta {\ss}_{1} + K\beta_{3} + K\beta_{5}) and K\beta'_{2} (= K\beta_{2} + K\beta_{4} + transitions from higher levels) lines have been measured and theoretically calculated for six elements with 62 \le Z \le 74 at excitation energy of 78.706 keV, the weighted avarage of K conversion x-rays emitted from Bi. The experimental results were compared with theoretically predicted values based on relativistic Hartree-Slater and Hartree-Fock theories, a comparison that was found to be in good agreement to within the experimental uncertainties.


Temperature Dependence Of Galvanomagnetic Properties For Lightly Doped N-Type Si, Aytunç Ateş, Beki̇r Gürbulak, Seydi̇ Doğan, Muhammet Yildirim, Sebahatti̇n Tüzemen Jan 2002

Temperature Dependence Of Galvanomagnetic Properties For Lightly Doped N-Type Si, Aytunç Ateş, Beki̇r Gürbulak, Seydi̇ Doğan, Muhammet Yildirim, Sebahatti̇n Tüzemen

Turkish Journal of Physics

The temperature dependence of Hall and magnetoresistance effects in n-type Si having a resistivity of 1400 {\Omega } cm at room temperature is studied in the temperature range of 210-320 K. The variation of transverse magnetoresistance as a function of temperature is similar to the longitudinal magnetoresistance variation in < 001 > and < 1\bar {1}0 > n-Si the samples. It is observed that, in < 001 > sample, the transverse and longitudinal magnetoresistance variation is greater than that in the < 1\bar {1}0 > sample. In both samples, the temperature dependences of magnetoresistance is in accordance to double space anisotropy parameters. In both samples, the transverse and longitudinal magnetoresistance coefficents increase with increasing …


Micro-Crystallographic, Optical And Transport Studies Of Cd_{0.7} Zn_{0.3} Se : Sb Thin Films, D. S. Sutrave, G. S. Shahane, V. B. Patil, L. P. Deshmukh, B. D. Sarwade Jan 2002

Micro-Crystallographic, Optical And Transport Studies Of Cd_{0.7} Zn_{0.3} Se : Sb Thin Films, D. S. Sutrave, G. S. Shahane, V. B. Patil, L. P. Deshmukh, B. D. Sarwade

Turkish Journal of Physics

Cd_{1-x}Zn_{x}Se thin film structures doped with various concentrations of trivalent antimony were chemically deposited onto glass-substrates. These structures were then characterised through the XRD, SEM, optical and electrical characterization techniques. The X-ray diffractograms of both as-prepared and Sb-doped samples were obtained and analysed. The analysis revealed that the samples are microcrystalline over the whole range of the doping concentration (0 to 2 mol %). It is striking that the intensities of hexagonal and cubic reflections of CdSe went on increasing with doping concentration upto 0.1 mol % and decreased with further increase in Sb^{3+} content in the film whereas peak …


Effect Of The Zn Concentration On The Characteristic Parameters Of Zn_{X}Cd_{1 - X}S Thin Films Developed By Spraying Pyrolysis Method Under The Nitrogen Atmosphere, Meti̇n Bedi̇r, Refi̇k Kayali, Mustafa Öztaş Jan 2002

Effect Of The Zn Concentration On The Characteristic Parameters Of Zn_{X}Cd_{1 - X}S Thin Films Developed By Spraying Pyrolysis Method Under The Nitrogen Atmosphere, Meti̇n Bedi̇r, Refi̇k Kayali, Mustafa Öztaş

Turkish Journal of Physics

The electronic and optical properties of Zn_{x}Cd _{(1- x)}S thin films (0.0 \le x \le 0.7) fabricated using the chemical spray method have been investigated in nitrogen atmosphere. The films are deposited on glass substrates at 420^oC substrate temperature. The related optical data are recorded in the wavelength range 200-700 nm. In addition, the absorption coefficient is determined and correlated with the photon energy in order to estimate the direct transition energy bandgap. The crystallite size and degree of preferential orientation were found to decrease with the increase of x and to improve upon annealing in vacuum at \cong 600^oC. …


Spatial Non-Uniformity Measurements Of Large Area Silicon Photodiodes, Murat Durak, Farhad Samadov, A. Kamuran Türkoğlu Jan 2002

Spatial Non-Uniformity Measurements Of Large Area Silicon Photodiodes, Murat Durak, Farhad Samadov, A. Kamuran Türkoğlu

Turkish Journal of Physics

Accurate determination of the responsivity of silicon photodiodes are highly desired in photometry. The change of responsivity over the surface, the so-called spatial non-uniformity, effects power measurements especially in photodiodes with large active areas. To study this effect, first an intensity-stabilized laser source-optics has been established. A purpose-built step-motor controlled two axis micro mechanical stage has been designed to scan the photodiode surface. In this study, the technique and the results of the uniformity mapping of large area research-grade silicon photodiodes which were measured on the purpose-built set-up are presented.


Some Characteristic Properties, Vithal Bhivaba Pujari, V. B. Gaikwad, E. U. Masumdar, P. D. More, L. P. Deshmukh Jan 2002

Some Characteristic Properties, Vithal Bhivaba Pujari, V. B. Gaikwad, E. U. Masumdar, P. D. More, L. P. Deshmukh

Turkish Journal of Physics

This paper presents some information regarding (Cd, Hg) Se materials synthesized by a simple chemical growth process and the structural, optical and electrical transport properties. The growth of these films depends on various preparative parameters and deposition conditions such as concentration of the starting materials, pH, temperature, time, speed of mechanical churning, etc., and the reaction kinetics suggests that the films grow into two different phases: one, initialy an almost linear phase; and second, a saturation phase. The deposits were analysed chemically and by an EDS techniques. It has been seen that more than 70% of the materials taken in …


Monitoring The Effect Of Recrystallization And Quenching In Almg_{X} Alloy By Pat, A. Ashour, Nour Zaki El-Said, Emad A. Badawi Jan 2002

Monitoring The Effect Of Recrystallization And Quenching In Almg_{X} Alloy By Pat, A. Ashour, Nour Zaki El-Said, Emad A. Badawi

Turkish Journal of Physics

Positron annihilation technique (PAT) lifetime measurements have been carried out on AlMg_{x} samples (x = 0.23, 0.85, 1.27 and 1.4 at %) with point defects and dislocations introduced by plastic deformation at room temperature. Clustering of vacancies was observed by quenching using PAT. The samples were annealed at 573 K for 12 hours to homogenize and divided into two sets. The first set of AlMg_{x} (x = 0.23, 0.85 and 1.4 at %) was deformed to 10, 25 and 35% thickness reduction. Isochronal annealing was studied in the range of 300-550 K. In the second set of measurements, AlMg_{x} (x …


Off-Diagonal Matrix Elements And Sum Rules Involving Coulomb And Isotropic Oscillator Functions, Harry A. Mavromatis Jan 2002

Off-Diagonal Matrix Elements And Sum Rules Involving Coulomb And Isotropic Oscillator Functions, Harry A. Mavromatis

Turkish Journal of Physics

Off-diagonal matrix elements and sum rules for the Coulomb and isotropic oscillator systems are obtained from a study of relations between the off-diagonal matrix elements of a general recursion relation.


Revised Stratigraphy And Facies Analysis Of Palaeocene-Eocene Supra-Allochthonous Sediments (Denizli, Sw Turkey) And Their Tectonic Significance, Hasan Sözbi̇li̇r Jan 2002

Revised Stratigraphy And Facies Analysis Of Palaeocene-Eocene Supra-Allochthonous Sediments (Denizli, Sw Turkey) And Their Tectonic Significance, Hasan Sözbi̇li̇r

Turkish Journal of Earth Sciences

A non-metamorphosed sedimentary sequence of Late Palaeocene-Eocene age exposed to the south of Dereköy Village (east of Denizli) was formerly interpreted as the uppermost part of the Menderes Massif. However, detailed field data indicates that the Dereköy succession rests unconformably on the Lycian ophiolitic mélange and thus cannot be accepted as a part of the Menderes sequence. The Dereköy succession consists of shelf to sub-marine sedimentary deposits that begin with a transgressive basal conglomerate, followed by limestone and then grading upward into clastic turbidites. The clastic beds have intra-basinal and extra-basinal fragments derived from carbonate lenses and the Lycian thrust …


Pyrite Deformation Textures In The Deposits Of The Küre Mining District (Kastamonu-Turkey), İlkay Kuşcu, Ayhan Erler Jan 2002

Pyrite Deformation Textures In The Deposits Of The Küre Mining District (Kastamonu-Turkey), İlkay Kuşcu, Ayhan Erler

Turkish Journal of Earth Sciences

The Küre volcanogenic massive sulfide deposits lie within the Kastamonu province in the western part of the Pontide tectonic belt of Turkey, and are hosted by ophiolite-related pre-Liassic basaltic sequences. Mineralogical studies of the pyritic massive sulfide deposits of the Küre mining district have shown that the sulfide assemblages, particularly pyrite, have undergone a history of deformation and metamorphism. The Küre volcanogenic massive sulfide deposits show a range of macroscopic and microscopic textures, which are also observed in metamorphosed VMS deposits elsewhere. These textures are cataclastic, annealing and fracture-filling textures which developed in two successive stages; cataclastic texture predominated during …