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1998

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Articles 2221 - 2250 of 2574

Full-Text Articles in Physical Sciences and Mathematics

Determination Of The Protonation Constants Of 2-[4-Dimethylaminocinnamalamino] Benzoic Acid (Dacab) In Dioxane - Water Medium And Preparation Of Some Of Its Transition Metal Complexes, Mustafa Yalçin, Harun Mutluay, Hüsnü Cankurtaran Jan 1998

Determination Of The Protonation Constants Of 2-[4-Dimethylaminocinnamalamino] Benzoic Acid (Dacab) In Dioxane - Water Medium And Preparation Of Some Of Its Transition Metal Complexes, Mustafa Yalçin, Harun Mutluay, Hüsnü Cankurtaran

Turkish Journal of Chemistry

In this study, the Schiff base 2-[4-Dimethylaminocinnamalamino]- benzoic acid [(CH$_3$)$_2$N.C$_6$H$_4$.CH:CH.N.C$_6$H$_4$.COOH] (DACAB) was prepared by the reaction of 2-Aminobenzoic acid with p-Dimethylaminocinnamaldehyde. The protonation constants of the ligand were determined in a 50\% (v/v) dioxane - water medium using the Irving-Rossotti and PKAS-BEST computer methods. The complexes of Fe(III), Co(II), Ni(II), Cu(II) with DACAB were synthesized and the structures of these complexes were elucidated by means of data obtained from elemental analysis, using IR, $^1$H-NMR methods. The magnetic properties of the solid complexes were measured.


Indirect Complexometric Determination Of Mercury Using Potassium Iodide As Selective Masking Agent, B. Muralidhara Rao Jan 1998

Indirect Complexometric Determination Of Mercury Using Potassium Iodide As Selective Masking Agent, B. Muralidhara Rao

Turkish Journal of Chemistry

This paper describes a indirect complexometric method for the determination of mercury in the presence of co-ions, based on the selective masking ability of potassium iodide. To the mixture of mercury (II) and other metal ion solution, EDTA solution was added in excess of the metal ions present. The pH of the solution was adjusted to 5.0-6.0 using solid hexamine ($10 \pm 2$ g) and surplus EDTA was titrated with zinc sulfate solution using xylenol orange indicator. An excess of solid potassium iodide was then added to decompose the Hg-EDTA complex and the released EDTA was titrated with standard zinc …


Optimization Of Starting Time And Period Of Induction And Inducer Concentration In The Production Of The Restriction Enzyme Ecori From Recombinant Escherichia Coli 294, Candan Yildir Tamerler, Z. İlsen Önsan, Betül Kirdar Jan 1998

Optimization Of Starting Time And Period Of Induction And Inducer Concentration In The Production Of The Restriction Enzyme Ecori From Recombinant Escherichia Coli 294, Candan Yildir Tamerler, Z. İlsen Önsan, Betül Kirdar

Turkish Journal of Chemistry

Induction parameters including inducer concentration, period of induction and the cell concentration at which inducer is to be added to the fermentation broth were optimized in order to increase the yield of the {\em Eco}RI restriction endonuclease isolated from recombinant {\em E. coli}. Bacterial cells harboring the plasmid pPG430 containing {\em Eco}RI endonuclease and the methylase genes under the control of {\em lac} promoter were used in the experiments where induction was accomplished by using lactose isopropyl-$\beta$-D-thiogalactoside (IPTG). An IPTG concentration of 0.1mM, the late exponential phase of growth (at an optical density of 1.2 at 595 nm) and an …


Reactions Of 4-Amino-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones And 4-Amino-4h-1,2,4-Triazoles With Some Carboxylic Acid Anhydrides, Şule Bahçeci̇, Nurhan İnce, Asun İki̇zler Jan 1998

Reactions Of 4-Amino-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones And 4-Amino-4h-1,2,4-Triazoles With Some Carboxylic Acid Anhydrides, Şule Bahçeci̇, Nurhan İnce, Asun İki̇zler

Turkish Journal of Chemistry

3-Alkyl(Aryl)-4-tetrachlorophthalimido-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) and 3-alkyl(aryl)-4-(1,8-naphthalimido)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were synthesized from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with tetrachlorophthalic anhydride and 1,8-naphthalic anhydride, respectively. In addition, the reactions of 4-amino-4H-1,2,4-triazoles (4) with succinic anhydride and phthalic anhydride were studied.


Cu And Pb Adsorption On Some Bentonitic Clays, Oğuz İnel, Fehmi Albayrak, Ayşgül Aşkin Jan 1998

Cu And Pb Adsorption On Some Bentonitic Clays, Oğuz İnel, Fehmi Albayrak, Ayşgül Aşkin

Turkish Journal of Chemistry

Cu$^{2+}$ and Pb$^{2+}$ adsorption isotherms were measured on some clay samples obtained from various regions of Turkey. Also specific surface areas of clays were determined from adsorption data of ortho-phenanthroline(OP). The adsorptions of ions and OP were studied using the batch equilibration technique as a function of adsorbate concentration. The adsorption data, over the whole range of concentrations used, follow the Langmuir adsorption isotherm. The retention capacities of the adsorbates and the cation exchange capacities of the clays were determined. Plots of K$_d$, the distribution coefficient of ions between the solid and solution phases, vs. $\Gamma$, the surface density of …


The Effectof Lanthanum And Barium Additives On The Thermal Stabilization Of \Gamma-Al_2o_3, A. İnci İşli̇, A. Erhan Aksoylu, Z. İlsen Önsan Jan 1998

The Effectof Lanthanum And Barium Additives On The Thermal Stabilization Of \Gamma-Al_2o_3, A. İnci İşli̇, A. Erhan Aksoylu, Z. İlsen Önsan

Turkish Journal of Chemistry

The effect of La and Ba additives on the thermal stabilization of $\gamma$-Al$_2$O$_3$ was investigated through total-surface-area measurements. The parameters considered were additive content, calcination temperature, and calcination period. The effect of precalcination was also studied. It was found that thermal stabilization caused by 3 wt\% La and Ba is superior to 6 wt \% La or Ba, and the positive effect of 3 wt\% La and 3 wt\% Ba are almost identical. The nearly threefold increase in the total surface area of 3 wt\% La or Ba doped samples calcined above the $\gamma - \alpha$ phase-transition temperature indicates that …


Gas Chromatography In The Low Concentration Determination Of Nitrous Oxide And Volatile Anaesthetics, Ahmet Uyanik Jan 1998

Gas Chromatography In The Low Concentration Determination Of Nitrous Oxide And Volatile Anaesthetics, Ahmet Uyanik

Turkish Journal of Chemistry

A previously reported single-column gas chromatographic separation method was modified for dual-detection gas chromatography (TCD+FID) and evaluated for the low concentration analysis of volatile anaesthetics (halothane, isoflurane) and nitrous oxide. It was found that no serious problem occurs in the determination of volatile anaesthetics with FID ($


Crystal Structure Of Dichlorodiaquabis-(P- Dimethylaminobenzaldehyde)Manganese(Ii), Veysel T. Yilmaz, Turan K. Yazicilar, Halis Ölmez, R. Alan Howie Jan 1998

Crystal Structure Of Dichlorodiaquabis-(P- Dimethylaminobenzaldehyde)Manganese(Ii), Veysel T. Yilmaz, Turan K. Yazicilar, Halis Ölmez, R. Alan Howie

Turkish Journal of Chemistry

The crystal structure of dichlorodiaquabis-($p$-dimethylaminobenzaldehyde)manganese(II), [MnCl$_2$(OH$_2$)$_2$(C$_9$H$_{11}$NO)$_2$], was determined from X-ray intensity data. The structure consists of the isolated molecules of the complex. The central Mn atom in the complex is coordinated by txo $p$-dimethylaminobenzaldehyde and two water molecules and also two chlorine atoms, resulting in a distorted octahedral environment. The same molecules or ions occupy {\it trans} positions. The crystal structure is stabilized by weak hydrogen bonds present between the isolated molecules.


Potential Utilization Of Fusel Oil: A Kinetic Approach For Production Of Fusel Oil Esters Through Chemical Reaction, Zeki Küçücük, Kadim Ceylan Jan 1998

Potential Utilization Of Fusel Oil: A Kinetic Approach For Production Of Fusel Oil Esters Through Chemical Reaction, Zeki Küçücük, Kadim Ceylan

Turkish Journal of Chemistry

Fusel oil is a by-product of the distillation of ethyl alcohol from the fermentation of molasses and contains mainly C3-C5 alcohols. Acetic acid and butyric acid esters of its major alcohol components have economic value as chemicals for flavor and fragrance manufacturing. This study presents some data regarding the uncatalyzed esterification of fusel oil with acetic acid, propionic acid and butyric acid. The reactions were carried out at two temperatures, i.e., $45^{\circ}$C and under the reflux conditions ($80-85^{\circ}$C). The composition of raw fusel oil and the reaction mixtures were determined by gas chromatography. The reaction rate constants for the formation …


Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik Jan 1998

Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik

Turkish Journal of Chemistry

It is well known that fish lipids are effective against cardiovascular diseases due to their high contents of polyunsaturated omega-3 (n-3) fatty acids. In order to determine a suitable fish diet, the fatty acid compositions and total lipid and cholesterol contents of 9 common fish species obtained from the central fish market in Ğstanbul were determined. Palmitic (C-16:0) and oleic acid (C-18:1) were the predominant saturated and monounsaturated fatty acids. The predominant polyunsaturated fatty acids were eicosapentaenoic (C-20:5) acid and docosahexaenoic (C-22:6) acid. The amounts of cholesterol in fish lipids did not differ significantly. Sardine ({\it Sardina pilchardus}) and mackerel …


Voltammetric Determination Of Thioridazine Hydrochloride, İnci Bi̇ryol, Saadet Dermi̇ş Jan 1998

Voltammetric Determination Of Thioridazine Hydrochloride, İnci Bi̇ryol, Saadet Dermi̇ş

Turkish Journal of Chemistry

This study describes the optimal conditions for the determination of Thioridazine HCl (Tz-HCl) in 0.2 M sulphuric acid by voltammetry using ruthenium (Ru), platinum (Pt) and glassy carbon (GC) electrodes. A new and sensitive method is described for electrochemical determination of Tz-HCl in the concentration range $5.10^{-5} - 10^{-3}$ M (20.35-407 $\mu$gml$^{-1}$); $6.10^{-4} - 10^{-2}$ M (244.2 - 4070 $\mu$gml$^{-1}$); $10^{-4} - 10^{-3}$ M (40,7 - 407 $\mu$gml$^{-1}$), with Ru, Pt and glassy carbon electrodes, respectively. The method was applied successfully to the determination of Tz-HCl in pure form or incorporated in their representative pharmaceutical preparations. The precision of the …


Polarographic Studies On The Kinetics Of The Electrode Reaction Of 4-Benzoyl-1,5 Diphenyl Pyrazole-3-Carboxylic Acid, M. Veri̇rşen, S. Erturan Jan 1998

Polarographic Studies On The Kinetics Of The Electrode Reaction Of 4-Benzoyl-1,5 Diphenyl Pyrazole-3-Carboxylic Acid, M. Veri̇rşen, S. Erturan

Turkish Journal of Chemistry

The polarographic behavior of 4-Benzoyl-1,5 diphenyl pyrazole-3- Carboxylic acid (BDPPCA) in aqueous ethanol solution (76 \% v/v) at 25^oC was studied as a function of pH using Mcl buffer solution. One well-defined wave was obtained in the pH range of 3.3-5.4. This wave, corresponding to two electron reduction processes, was irreversible and diffusion controlled. However, in the pH range of 5.4-7.4 a single reversible and diffusion-controlled wave involving two electrons resulted. The kinetic parameters $(n_a, k^o_{f,h})$ were calculated by Koutecky's method. A tentative mechanism was put forward for the reduction process of depolarizer. Furthermore, the effects of different supporting electrolytes …


Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk Jan 1998

Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk

Turkish Journal of Chemistry

Aliphatic and aromatic alcohols are amphiprotic compounds which have both polar and nonpolar parts in their structure. These compounds were studied with respect to the nonreactive toxic effects on the microorganism {\it Pseudomonas putida}. The toxicity of these chemicals to aerobic bacterium {\it P. putida} was measured in terms of inhibition of dehydrogenase activity. The test results, expressed as concentration of chemicals 50\% effective in inhibition (IC$_{50}$), were correlated with their physicochemical properties such as aqueous solubility (S) and octanol-water partition coefficient (P).


Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan Jan 1998

Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan

Turkish Journal of Chemistry

In this study, ethanol was produced with the microorganism {\em Saccharomyces cerevisiae} by using sucrose as a substrate. Batch processes were tested by using the same substrate, microorganism and medium composition. {\em Saccharomyces cerevisiae}, used in the free form in the first group of experiments, was immobilized by different methods. In the second group of experiments agar, sponge and a natural material called luffa cylindrica fiber were used as support materials. The batch processes with free and immobilized microorganisms were compared with respect to efficiency and yield.


The Effectof Temperature On The Dynmaic Viscosity Of Acetone Sunflower-Seed Oil Mixtures, Hüseyin Topallar, Yüksel Bayrak Jan 1998

The Effectof Temperature On The Dynmaic Viscosity Of Acetone Sunflower-Seed Oil Mixtures, Hüseyin Topallar, Yüksel Bayrak

Turkish Journal of Chemistry

The effect of acetone on the dynamic viscosity of sunflower-seed oil was studied under a dynamic heating regime at temeparuters ranging from 25^oC to 50^oC at 5^oC intervals. Acetone dramatically reduced the viscosity of sunflower-seed oil. The reduction of viscosity was far less with further addition of acetone. A linear relationship was found between the density of sunflower-seed oil and temperature. The influence of a solvent on the density of the sunflower-seed oil/acetone solution can be accounted for by the mixing theory of ideal solutions, whereas the effect of temperature on the dynamic viscosity of the oil solution is best …


Further Studies On The Reaction Of Unsaturated Acids With O-Phenylenediamine And 4-Substituted O-Phenylenediamines In Acid Medium, Mashooda Hasan, Shagufta Munawar, Naeema Khan, Zahida Maqbool Jan 1998

Further Studies On The Reaction Of Unsaturated Acids With O-Phenylenediamine And 4-Substituted O-Phenylenediamines In Acid Medium, Mashooda Hasan, Shagufta Munawar, Naeema Khan, Zahida Maqbool

Turkish Journal of Chemistry

Condensation of methylcrotonic acid with 4-chloro-o-phenylenediamine in 4N HCl yielded 5-chloro-2-(1-isobutenyl)benzimidazole and 7-chloro-4, 4-dimethyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one. Methacrylic acid when condensed with o-phenylenediamine in 4N HCl yielded the already reported 3-methyl-1,2,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one and 2(2-propenyl)benzimidazole. Condensation of methacrylic acid with 4-chloro-o-phenylenediamine in 4N HCl yielded 5-chloro-2(2-propenyl)benzimidazole. The structures of all the purified compounds were confirmed with the help of mass and $^1$H NMR spectral analysis.


Solvent Extraction Of La^{3+} Withethylenediamine-N,N'-Ditetradecyl-N,N'-Diacetic Acid(Eddat) In Dichloromethane, Mürüvvet Yurdakoç, Halil Hoşgören Jan 1998

Solvent Extraction Of La^{3+} Withethylenediamine-N,N'-Ditetradecyl-N,N'-Diacetic Acid(Eddat) In Dichloromethane, Mürüvvet Yurdakoç, Halil Hoşgören

Turkish Journal of Chemistry

Ethylenediamine-N,N'-ditetradecyl-N,N'-diacetic acid (EDDAT) was synthesized for the solvent extraction of La$^{3+}$. EDDAT was prepared from ethylenediamine-N,N'-diacetic acid (EDDA) and tetradecyl bromide in a basic n-amylalcohol-ethanol-water solvent system. The structure of this new extracting reagent was identified according to spectroscopic data, i.e. $^{13}$C NMR, $^1$H NMR, and elemental analysis results. The solvent extraction of La$^{3+}$ with EDDAT in dichloromethane was studied as a function of parameters of the aqueous and organic phases. The optimal extraction conditions were determined. The extraction yield increased with a decrease in hydrogen ions in the aqueous phase. Stripping of the La$^{3+}$ loaded organic phase was achieved …


Kinetic Studies Of The Thermal Decomposition Of Di- And Tri-Organotin Derivatives Of 1-Nitroso-2-Naphthol, Saqib Ali, Moazzam H. Bhatti, Sohail Mahmood, Muhammad Mazhar, M. Saleem Khalid, Nazar Hussain Jan 1998

Kinetic Studies Of The Thermal Decomposition Of Di- And Tri-Organotin Derivatives Of 1-Nitroso-2-Naphthol, Saqib Ali, Moazzam H. Bhatti, Sohail Mahmood, Muhammad Mazhar, M. Saleem Khalid, Nazar Hussain

Turkish Journal of Chemistry

The di- and tri-organotin complexes of general formula R$_2$SnL$_2$ and R$_3$SnL where R = C$_4$H$_9$, C$_6$H$_5$, C$_6$H$_5$CH$_2$, C$_6$H$_{11}$ and L=1-nitroso-2-naphthol, were subjected to thermal decomposition by means of thermogravimetry (TG). The decomposition occurred in steps and the kinetics of every set of reactions were determined using the method described by Coats and Redfern. These results were analysed to establish the decomposition kinetics and hence to calculate activation energies. The activation energies were also determined by applying the method described by Horowitz, which yielded comparable results.


Thermal Behaviour Of Some Azo Dyes Containing Sterically Hindered And Water-Soluble Groups, Hasan Kocaokutgen, Zerrin Heren Jan 1998

Thermal Behaviour Of Some Azo Dyes Containing Sterically Hindered And Water-Soluble Groups, Hasan Kocaokutgen, Zerrin Heren

Turkish Journal of Chemistry

Thermal behaviour of six azo dyes containing steric hindered groups such as tert-butyl, sec-butyl and isopropyl, were investigated by means of thermogravimetry (TG), differential thermal analysis (DTA) and differential thermogravimetry (DTG). The thermal decomposition points and amount of volatile pyrolysis products, were determined in nitrogen atmosphere using TG, DTA and DTG curves.


Crystal And Molecular Structure Of Tris(2,6-Dichlorophenyl) Thiophosphate, Veysel T. Yilmaz, Mustafa Odabaşoğlu, R. Alan Howie Jan 1998

Crystal And Molecular Structure Of Tris(2,6-Dichlorophenyl) Thiophosphate, Veysel T. Yilmaz, Mustafa Odabaşoğlu, R. Alan Howie

Turkish Journal of Chemistry

The crystal structure of tris(2,6-dichlorophenyl)thiophosphate was determined by single crystal X-ray diffractometry. The structure consists of isolated molecules and each unit cell contains 8 molecules of the compound. The crystal system is monoclinic with a space group of C2/c. The P atom is bonded to three O atoms and one S atom in a distorted tetrahedron environment.


Reflective Remote Method Invocation, George K. Thiruvathukal, Lovely S. Thomas, Andy T. Korczynski Jan 1998

Reflective Remote Method Invocation, George K. Thiruvathukal, Lovely S. Thomas, Andy T. Korczynski

Computer Science: Faculty Publications and Other Works

Remote Method Invocation (RMI) is available in the current Java language design and implementation, providing the much-needed capability of allowing objects running in different Java processes to collaborate using a variation on the popular Remote Procedure Call (RPC).

Although RMI provides features which are desirable for high-performance distributed computing, its design and implementation are deficient in key areas of importance to the high-performance computing community in general. This paper addresses the key deficiencies of RMI and how these deficiencies affect the design and implementation of distributed object applications.

Reflective RMI (RRMI) is an open RMI implementation which makes better use …


Wide-Area Implementation Of The Message Passing Interface, Ian Foster, Jonathan Geisler, William Gropp, Nicholas Karonis, Ewing Lusk, George K. Thiruvathukal, Steven Tuecke Jan 1998

Wide-Area Implementation Of The Message Passing Interface, Ian Foster, Jonathan Geisler, William Gropp, Nicholas Karonis, Ewing Lusk, George K. Thiruvathukal, Steven Tuecke

Computer Science: Faculty Publications and Other Works

The Message Passing Interface (MPI) can be used as a portable, high-performance programming model for wide-area computing systems. The wide-area environment introduces challenging problems for the MPI implementor, due to the heterogeneity of both the underlying physical infrastructure and the software environment at different sites. In this article, we describe an MPI implementation that incorporates solutions to these problems. This implementation has beenconstructed by extending the Argonne MPICH implementation of MPI to use communicationservices provided by the Nexus communication library and authentication, resource allocation, process creation/management, and information services provided by the I-Soft system (initially) and the Globus metacomputing toolkit …


The Effect Of Temperature Dependent Frequency Factor On The Evaluated Trapping Parameters Of Tsl Glow Curves, A. N. Yazici, Z. Öztürk Jan 1998

The Effect Of Temperature Dependent Frequency Factor On The Evaluated Trapping Parameters Of Tsl Glow Curves, A. N. Yazici, Z. Öztürk

Turkish Journal of Physics

The effect of temperature dependency on frequency factor and its relationship to trapping parameters is discussed by using the peak shape method. The coefficients appearing in the peak shape formula for the calculation of the activation energy have been determined and tabulated for the symmetry factor $\mu_g(X)$ for $x=0.50$ and 0.75 of the peak intensity. It is found that significant errors occur in the value of the trapping parameters if the temperature dependecy of the frequency factor is not consider.


Fine Structure Analysis Of 4702 ^Oa Band Of The Molecule, M.B. Sureshkumar, S.R. Srikant Jan 1998

Fine Structure Analysis Of 4702 ^Oa Band Of The Molecule, M.B. Sureshkumar, S.R. Srikant

Turkish Journal of Physics

The emission spectrum of the cobalt monochloride molecule has been excited in a high frequency discharge tube source and the (0,0) band of H-system at 4702 \AA was photo-graphed at an inverse dispersion of 0.973 \AA/mm in the 5th order of a two meter plane grating spectrograph (Carl-Zeiss). The fine structure analysis of the band has been carried out and the molecular constants are reported for the first time. Rotational isotopic shift due to $^{37}$Cl support the analysis. The electronic transition involved is of the type $0^-$----- $0^-$ of case (c) which is equivalent of $^{3}\sum^{+}$-----$^{3}\sum^+$ or $^5\sum^+$-----$^5\sum^+$.


The Space-Time Critical Dimension Of An Open Parabosonic String, N. Mebarki & N. Belaloui, M. Haouchine Jan 1998

The Space-Time Critical Dimension Of An Open Parabosonic String, N. Mebarki & N. Belaloui, M. Haouchine

Turkish Journal of Physics

Using analytical properties of a 1-loop open parabosonic M-point transition amplitude, we show that the space-time critical dimension depends on the order of the paraquantization.


The Structure Of (001) Csl Twist Boundaries In Fcc Metals, A. Ghafoor, S.A. Ahmad, B.A.S. Faridi Jan 1998

The Structure Of (001) Csl Twist Boundaries In Fcc Metals, A. Ghafoor, S.A. Ahmad, B.A.S. Faridi

Turkish Journal of Physics

Computer simulation techniques based on discrete lattice approach and empirical many-body potentials have been used to study the structure and energy of $\Sigma = 5$, and $\Sigma = 13$ coincident site lattice (001) twist boundaries in three fcc metals. Energy computed for $\Sigma = 5$ boundary in copper is 17.5 \% less than the earlier result obtained by using pair potential. However the present calculations of twist boundary energies are somewhat higher than the results obtained using embedded atom method.


Low-Temperature Phase Transition In Tl In Se_{2} Crystals, Oktay Zeynelabidin O Alekperov, Mazahir Amirjan Oglu Aljanov, Elmira M. Ali Gizi Keri̇mova Jan 1998

Low-Temperature Phase Transition In Tl In Se_{2} Crystals, Oktay Zeynelabidin O Alekperov, Mazahir Amirjan Oglu Aljanov, Elmira M. Ali Gizi Keri̇mova

Turkish Journal of Physics

Heat capacity, lattice parameter, spectral and temperature dependences of photoconductivity of chained crystal Tl In Se_{2} have been investigated in this work. For the first time, it has been found that the phase transtion takes plase at temperatures 135 and 184 K in this crystal. The changes of heat capacity, photoconductivity and lattice parameter of Tl In Se_{2} in the region of phase transition is supposed to be connected with the presence of an incommensurate phase in this crystal.


Coulomb Breakup Of Nucleus ^6 Li On Ion ^{208}Pb, B. F. Irgaziev, H. T. Ergashbaev Jan 1998

Coulomb Breakup Of Nucleus ^6 Li On Ion ^{208}Pb, B. F. Irgaziev, H. T. Ergashbaev

Turkish Journal of Physics

In the framework of the three-body approach the A(a,bc)A Coulomb breakup has been investigated. The three-body Coulomb dynamic is taken into account to derive the expression for the reaction matrix element. The mechanism of the breakup includes the direct process and the excitation of resonance state of the particle a. The calculation of the triple differential cross section of the ^{208}Pb(^6Li, \alpha d)^{208}Pb Coulomb dissociation have been performed in the energy region E_{\alpha d} < 1MeV. Calculations for the Coulomb dissociation ^{208}Pb(^6Li, \alpha d)^{208}Pb, including consideration of the triple cross section going through the first resonance of ^6Li have been performed. The results of the calculations are compared with experimental data.


Ree Chemistry Of Arid Zone Calcrete Profiles-A Case Study From The Thar Desert, India, D. Ramakrishnan, Krishna Chandra Tiwari Jan 1998

Ree Chemistry Of Arid Zone Calcrete Profiles-A Case Study From The Thar Desert, India, D. Ramakrishnan, Krishna Chandra Tiwari

Turkish Journal of Earth Sciences

Calcrete is the widely prevalent duricrust associated with the weathering profiles of the Thar desert. The studies on REE behaviour within different weathering horizons of calcrete profiles, have revealed distinct pattern of enrichment and depletion. Fractionation of REE as evidenced through La/Lu, La/Sm, Nd/Dy ratios and removal index, are attributed to pedogenic processes such as breakdown of micas, pyroxenes, amphiboles, feldspars; removal of elements as soluble complexes; selective fixation of elements in neoformed clay minerals like montmorillonite, illite and chlorite. Sesquioxides rich Bir horizon shows enrichment of REE. REE depletion in Palaeo- Bt horizons could be due to their removal …


Post-Collisional Central Anatolian Alkaline Plutonism, Turkey, Durmuş Boztuğ Jan 1998

Post-Collisional Central Anatolian Alkaline Plutonism, Turkey, Durmuş Boztuğ

Turkish Journal of Earth Sciences

A number of Upper Cretaceous-Palaeogene alkaline plutons intruded into the crustal metamorphic rocks, the pre-Maastrichtian ophiolitic mélange, and the Cretaceous-Lower Tertiary units are located in the Central Anatolia (CA), Turkey. These alkaline plutons constitute an important association in the post-collisional Central Anatolian Granitoids. The Dumluca, Murmana, Karakeban, Kösedağ, Hasançelebi, Karaçayir and Davulalan plutons constitute the eastern; whereas the Egrialan, Baranadağ, Hamit, Çamsarı, Durmuslu and Bayindir units the western part of this alkaline association. These plutons are mainly composed of silica oversaturated syenitic to monzonitic, and undersaturated syenitic felsic rocks. However, the Dumluca, Murmana and Karakeban plutons also include some undersaturated …