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Full-Text Articles in Physical Sciences and Mathematics

The Effects Of Polyacrylic Acid/Polypyrrole Composite Coating On Photocorrosion And Photoactivity Of Pyrite Electrodes, A. Sezai Saraç, Belkıs Ustamehmetoğlu, Esma Sezer, Candan Erbi̇l Jan 1996

The Effects Of Polyacrylic Acid/Polypyrrole Composite Coating On Photocorrosion And Photoactivity Of Pyrite Electrodes, A. Sezai Saraç, Belkıs Ustamehmetoğlu, Esma Sezer, Candan Erbi̇l

Turkish Journal of Chemistry

Electrically conducting polyacrylic acid (PAA)/Polypyrrole (PPy) composite films were prepared by electrochemical polymerization of pyrrole on PAA which was electrocheimically adsorbed on natural and synthetic pyrite ( FeS_{2}) electrodes. The application of such polymer coating on pyrite, which is one of the semiconducting materials for solar applications, shows almost total protection against corrosion and can improve the photoactive character of the electrode. Addition of Ce(IV) ammonium nitrate into this system improved the photoactivity of the PAA/PPy composite. The composite polymer has higher photoconductivity than the pure PPy, because of the doping effect of anions on the PPA/PPy composite.


The Mechanism Of The Photoprotolytic Reactions Of Some Oxyazomethine Compounds, Lubov Efimovna Zelt'ser, Milan B. Bastic, Ljubinka V. Rajakovic Jan 1996

The Mechanism Of The Photoprotolytic Reactions Of Some Oxyazomethine Compounds, Lubov Efimovna Zelt'ser, Milan B. Bastic, Ljubinka V. Rajakovic

Turkish Journal of Chemistry

The kinetic spectral study of the photoprotolytic reactions of oxyazomethine molecules was performed. It was established that the deprotonation reactions of oxyazomethines proceed with the participation of electronically excited molecules and are characterized by parameters which differ to basic state reactions.


Synthesis Of Some Pyrazolo-Pyridazine Compounds, Adem Önal, Yunus Akçamur, Behzat Altural Jan 1996

Synthesis Of Some Pyrazolo-Pyridazine Compounds, Adem Önal, Yunus Akçamur, Behzat Altural

Turkish Journal of Chemistry

Addition of {\bf 1} to two moles of phenylhydrazine gives 1,2,4,6- tetraphenyl-(2,3-d)-pyrazolo-5,6-pyridazine-7-one {\bf 4} isomer compound 1, 2,3,5-tetraphenyl-(2,3-d) pyrazolo-5,6-pyridazine-7-one {\bf 5} of {\bf 4} was synthesized by the reaction of {\bf 2} with phenylhydrazine. 3,4- Diphenyl-(2,3-d)-pyrazolo-(1H,6H)-pyridazine-7-one {\bf 6} was also obtained in two different ways. Reaction of {\bf 1} and 4-benzoyl-5 phenyl- furan-2,3-dione {\bf 3} with hydrazinium hydrate furnished compound {\bf 6}. The structures of {\bf 4,5} and {\bf 6} were determined by the ^{13} C- NMR, IR spectra and elemental analysis. These new isomer and condensed compounds synthesized in this study are important for heterocyclic chemistry.


Synthesis Of Optically Active Camphorsulphonylbenzimidazoles, Mashooda Hasan, Humaira Masood, Naeema Khan, M. Zia-Ul-Haq Jan 1996

Synthesis Of Optically Active Camphorsulphonylbenzimidazoles, Mashooda Hasan, Humaira Masood, Naeema Khan, M. Zia-Ul-Haq

Turkish Journal of Chemistry

The preparation of optically active camphorsulphonylbenzimidazole {(\bf 1)}, a mixture of regioisomeric 5-nitro- {\bf (2A)} and 6-nitro-{\bf (2B)} camphorsulphonylbenzimidazoles, 5-nitro-{\bf (3A)} and 6-nitro-{\bf (3B)} 2- methyl camphorsulphonylbenzimidazoles is described. In this study the structure of the purified camphorsulphonylbenzimidazoles {\bf 1, 2B, 3A} and {\bf 3B} was confirmed by their mass and ^{1}H NMR spectral analysis. The specific rotation of each pure compound is also reported.


Structural Fusion Of Condensed Benzenoid Systems, Lemi Türker Jan 1996

Structural Fusion Of Condensed Benzenoid Systems, Lemi Türker

Turkish Journal of Chemistry

On the basis of ring topologies, some theorems for the structural fusion of condensed benzenoids are presented. It has been proved that the oddness or evenness of the fused system is dictated by the degree of fusion.


An Unusual Zinc-Promoted Reductive Retro-Wagner-Meerwein Rearrangement, Yavuz Taşkesenli̇gi̇l, Metin Balci Jan 1996

An Unusual Zinc-Promoted Reductive Retro-Wagner-Meerwein Rearrangement, Yavuz Taşkesenli̇gi̇l, Metin Balci

Turkish Journal of Chemistry

Bromination and dehydrobromination of exocyclic olefin {\bf 8} resulted in the formation of bromomethylene compound {\bf 9} and Wagner-Meerwein rearrangement product {\bf 10}. The dehydrobromination of {\bf 10} with potassium {\it tert}-butoxide provided the corresponding bromomethyl compound {\bf 11} in high yield. Reaction of {\bf 11} with Zn-Cu couple in methanol afforded the methyl derivative {\bf 12} and the parent olefin {\bf 8}. The unusual formation mechanism of {\bf 8} has been discussed in term of a reductive retro-Wagner-Meerwein rearrangement.


The Epoxidation Of Oil Obtained From The Eastern Black Sea Fishes, Eyüp Özcan, Bahri Ülküseven Jan 1996

The Epoxidation Of Oil Obtained From The Eastern Black Sea Fishes, Eyüp Özcan, Bahri Ülküseven

Turkish Journal of Chemistry

In this study we have investigated the suitable reaction conditions for the epoxidation of the semi-refined fish oil obtained from the fishes of eastern Black Sea, with peracetic acid. Various oxidation mixtures to reach the highest epoxyd-oxygene amount have been tested mean while the effective factors were established. In order to establish some specifications of the epoxy-product. Iodine-, hydroxyl-indices and epoxyd-oxygene percents were determined. We've also tried to explain how some reaction conditions (mole ratio of acetic acid to double bond and temperature) influenced the epoxy-product.


An Extension Of The Binomial Theorem With Application To Stability Theory, Z. Zahreddinea Jan 1996

An Extension Of The Binomial Theorem With Application To Stability Theory, Z. Zahreddinea

Turkish Journal of Mathematics

We show how it is possible to put different stability types such as Routh-Hurwitz and Schur-Cohn on common grounds by establishing direct links between them. In the process, we obtain natural and elegant extensions of both Pascal's rule and the binomial theorem, which prove useful in establishing our main results. A M S subject classification: Primary 34D, Secondary 93D.


The Inverse Nonstationary Scattering Problem For A Hyperbolic System Of Equations On Semi-Axis, N. Sh. Iskenderov, A. Yildiz Jan 1996

The Inverse Nonstationary Scattering Problem For A Hyperbolic System Of Equations On Semi-Axis, N. Sh. Iskenderov, A. Yildiz

Turkish Journal of Mathematics

In this paper, the direct and inverse nonstationary scattering problem for a hyperbolic system of n equations (n>3) on a semi-axis is studied. The coefficients of the system are uniquely determined according to scattering operator. The solution of the problem is generalized for an arbitrary natural number n applying the properties of separation of factors by means of operator transformations to some elements of the scattering operator and its inverse as well as reducing the scattering problem given on a semi-axis to the scattering problem on the whole-axis.


Some Applications Of Fractional Calculus Operators To A Certain Subclass Of Analytic Functions With Negative Coefficients, Nak Eun Cho, M. K. Aouf Jan 1996

Some Applications Of Fractional Calculus Operators To A Certain Subclass Of Analytic Functions With Negative Coefficients, Nak Eun Cho, M. K. Aouf

Turkish Journal of Mathematics

The object of the present paper is to prove various distortion theorems for the fractional calculus of functions in the class T_{n}\left(\lambda,\alpha\right) consisting of analytic and univalent functions with negative coefficients. Furthermore, a distortion theorem for a fractional integral operator of functions in the class T_{n}\left(\lambda,\alpha\right) is shown.


On A Differential Sequence In Geometry, E. Ortaçgi̇l Jan 1996

On A Differential Sequence In Geometry, E. Ortaçgi̇l

Turkish Journal of Mathematics

We construct an exact differential sequence which indicates certain relations between curvature, local flatness, torsion and simplicity of higher order connections. Our formulas are expressed explicity in terms of the Christoffel symbols of dual \varepsilon-connections.


On The \Ell_{P} Norms Of Almost Cauchy-Toeplitz Matrices, D. Bozkurt Jan 1996

On The \Ell_{P} Norms Of Almost Cauchy-Toeplitz Matrices, D. Bozkurt

Turkish Journal of Mathematics

In this study, we have given the definition of almost Cauchy-Toeplitz matrix. i.e. its elements are t_{ij}= a(i=j) and t_{ij}=1/(i-j)\, (i\neq j) such that a is a real number. We have found a lower and upper bounds for the \ell_{p} norm of this matrix. Furthermore, we have done the proof of the conjecture that were given by myself for the spectral norm of this matrix.


On (\Sigma,\Tau) Derivations With Module Values, M. Soytürk Jan 1996

On (\Sigma,\Tau) Derivations With Module Values, M. Soytürk

Turkish Journal of Mathematics

Let R be a ring, X\neq (0) an R-bi-module, d: R\ra X a(\sigma,\tau)- derivation with module value such that d\sigma=\sigma d, d\tau=\tau d and U\neq (0) an ideal of R. Furthermore the following properties are also satisfied. \begin{eqnarray*} && \mbox{For }x\in X, a\in R\quad x Ra=0 \mbox{ implies } x=0 \mbox{ or } a=0 \ldots\ldots (G_{1})\\ && \mbox{For }a\in R, x\in X \quad a Rx=0 \mbox{ implies } a=0 \mbox{ or } x=0 \ldots\ldots (G_{2}) \end{eqnarray*} \noindent In this paper we have proved the following results; (1) If (G_{1}) (or (G_{2})) is satisfied and for a \in R, d(U) a=0 …


Magnetic Solid-Phase Extraction Of Trace Cobalt(Ii) On Iron Oxide-Hexagonal Boron Nitride In Water And Food Samples, Mustafa Soylak, Ali Mohammednour Ali Mohammed, Furkan Uzcan Jan 1970

Magnetic Solid-Phase Extraction Of Trace Cobalt(Ii) On Iron Oxide-Hexagonal Boron Nitride In Water And Food Samples, Mustafa Soylak, Ali Mohammednour Ali Mohammed, Furkan Uzcan

Turkish Journal of Chemistry

Determination of trace cobalt(II) (Co(II)) in real samples remains challenging because of its very low concentration and strong matrix interferences. In this study, a simple and green magnetic solid-phase extraction (mSPE) method was developed for the selective separation and preconcentration of Co(II) ions using a newly designed iron oxide/hexagonal boron nitride (IOhBN) nanocomposite. The material was synthesized through a one-step, surfactant-free coprecipitation process, combining the high surface area, stability, and layered structure of hBN with the magnetic and reactive features of Fe₃O₄ nanoparticles. This hybrid structure provided abundant active sites and rapid magnetic separability, enabling efficient extraction within 5 min …