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Full-Text Articles in Physical Sciences and Mathematics

Synthesis Of Azobenzo[B]Thiophene Derivatives And Their Dyeing Performance On Polyester Fibre, Hari Raghav Maradiya Jan 2001

Synthesis Of Azobenzo[B]Thiophene Derivatives And Their Dyeing Performance On Polyester Fibre, Hari Raghav Maradiya

Turkish Journal of Chemistry

Ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate was synthesised by the reaction of cyclohexanone and sulphur with ethylcyanoacetate. The 2-aminothiophene derivative was diazotised and coupled with various N-arylmaleimides to give monoazo disperse dyes. The dyeing performance of these dyes was assessed on polyester fabric. These dyes were found to give light pink to reddish pink shades with very good depth and levelness on polyester fabric. The dyed fabric showed fair light fastness and excellent washing, rubbing, perspiration and sublimation fastness. The dyebath exhaustion on polyester fabric was found to be good and acceptable.


Purification And Partial Characterisation Of Superoxide Dismutase From Chicken Erythrocytes, Tüli̇n Aydemi̇r, Leman Tarhan Jan 2001

Purification And Partial Characterisation Of Superoxide Dismutase From Chicken Erythrocytes, Tüli̇n Aydemi̇r, Leman Tarhan

Turkish Journal of Chemistry

Superoxide dismutase (SOD), which plays a very important role in protecting organisms from oxygen toxicity, was purified from chicken erythrocyte and partially characterised. Erythrocyte membranes were disintegrated via freeze-thaw methods in the presence of Triton X-100. Following ethanol precipitation, SOD-containing solution was applied to DEAE-cellulose and then Sephadex G-100 gel columns. Chicken erythrocyte SOD was purified 508-fold with a specific activity of 8,480 units per mg. The molecular weight was estimated to be 30.6 kDa \pm 0.4 by gel filtration. The enzyme was composed of two subunits of equal size and contained one atom of copper and one atom of …


Study Of The Effect Of Number Of Layers On The Electrosynthesis Of Cobalt(Iii) Acetate In A Bipolar Packed-Bed Flow Reactor, Altan Güvenç, Belgi̇n Karabacakoğlu Jan 2001

Study Of The Effect Of Number Of Layers On The Electrosynthesis Of Cobalt(Iii) Acetate In A Bipolar Packed-Bed Flow Reactor, Altan Güvenç, Belgi̇n Karabacakoğlu

Turkish Journal of Chemistry

Cobalt(III) acetate, which is an important oxidizing agent and catalyst in organic reactions, was electrosynthesized from cobalt(II) acetate solution in a bipolar packed-bed flow reactor. In order to determine the effect of the number of layers on the yield of cobalt(III) acetate, experiments were performed in three different lengths of bipolar electrode cells, namely 16, 29 and 55 layers of graphite Raschig rings. The experiments were carried out at controlled potentials of 50-450 V, measuring the total current and using the solution (5% H_{2}O, 95% CH_{3}COOH, 0.06MCo(CH_{3}COO)_{2}.4H_{2}O, 0.2M CH_{3}COONa.3H_{2}O) at 298 K and 0.133 L.h^{-1} flow rate. According to the …


Voltammetry Of The Anticancer Drug Mitoxantrone And Dna, Arzum Erdem, Mehmet Özsöz Jan 2001

Voltammetry Of The Anticancer Drug Mitoxantrone And Dna, Arzum Erdem, Mehmet Özsöz

Turkish Journal of Chemistry

The interaction of mitoxantrone (MTX) with calf thymus double-stranded DNA (dsDNA) and calf thymus single-stranded DNA (ssDNA) was studied electrochemically by using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) at a carbon paste electrode (CPE). The changes in the experimental parameters (the concentration of MTX, the concentration of DNA and the accumulation time of MTX) were studied by DPV; in addition, the detection limit and the reproducibility were determined. It was observed for the interaction of MTX with dsDNA and ssDNA that the signal of the bare electrode was higher than the signal of the dsDNA modified CPE. The …


Separation Process Of Citric Acid With Tertiary Amines/Diluents In Supercritical Co_{2}, Arzu Koparan, Afi̇fe Güvenç, Nurcan Kapucu, Ülkü Mehmetoğlu, Ayla Çalimli Jan 2001

Separation Process Of Citric Acid With Tertiary Amines/Diluents In Supercritical Co_{2}, Arzu Koparan, Afi̇fe Güvenç, Nurcan Kapucu, Ülkü Mehmetoğlu, Ayla Çalimli

Turkish Journal of Chemistry

Reactive extraction of citric acid was investigated at atmospheric and supercritical conditions. The most suitable diluent and amine from among the tertiary amines and eight different diluents were determined at atmospheric conditions. The distribution coefficient values obtained with Hostarex A 327 were higher than those of Alamine 336. The selected amine (Hostarex A327) and the diluent (Oleyl alcohol) were used for reactive extraction of citric acid at supercritical conditions. Separation yields of citric acid were obtained in the temperature ranges of 308 to 328 K and in the pressure ranges of 80 to 180 bars in a supercritical extraction system …


Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n Jan 2001

Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n

Turkish Journal of Chemistry

A spectrophotometric method was developed for the determination of the beta adrenergic blocking drug propranolol. The method was based on the formation of Cu(II), Ni(II) and Co(II)-dithiocarbamate complexes from the secondary amine group of propranolol with carbondisulfide (CS_{2}) and the acetate salts of the metals in ammonia medium. The method was applied to the analysis of propranolol tablets and the results were statistically compared with those obtained by the official method using t- and F-tests. There was no significant difference between the mean values and the precisions of the two methods at the 95% confidence level.


Synthesis And Spectrophotometric Investigation Of A New Vic-Dioxime Ligand And Its Transition Metal Complexes, Mustafa Dolaz, Mehmet Tümer, Ayşegül Gölcü, Selahatti̇n Seri̇n Jan 2001

Synthesis And Spectrophotometric Investigation Of A New Vic-Dioxime Ligand And Its Transition Metal Complexes, Mustafa Dolaz, Mehmet Tümer, Ayşegül Gölcü, Selahatti̇n Seri̇n

Turkish Journal of Chemistry

A new vic-dioxime ligand and its Cu(II), Co(II), Ni(II), Pd(II), VO(IV) and Zn(II) complexes have been prepared and characterized by elemental analyses, infrared, electronic spectra, magnetic moment and molar conductance data. The Ni(II), Pd(II) and Zn(II) complexes have a diamagnetic character. The ^{1}H- and ^{13}C-nmr and GC/MS spectra of the vic-dioxime ligand and its Ni(II), Pd(II) and Zn(II) complexes were recorded. In addition, all compounds are non-electrolyte.


New Photochemical And Electrochemical Methods For The Degradation Of Pesticides In Aqueous Media. Environmental Applications, J. J. Aaron, Mehmet A. Oturan Jan 2001

New Photochemical And Electrochemical Methods For The Degradation Of Pesticides In Aqueous Media. Environmental Applications, J. J. Aaron, Mehmet A. Oturan

Turkish Journal of Chemistry

The development of new electrochemical and photochemical methods for the decontamination of natural water containing significant concentrations of aromatic pesticides is described. The electrochemical method is based on the electro-Fenton process, i.e. the simultaneous reduction of O_{2} and Fe^{3+} ions. Hydroxyl (OH^{.}) radicals are electrosynthesized in aqueous solutions, followed by complete mineralization of the initial pollutants. The photochemical methods involve either a direct photodegradation reaction of pesticides by UV light, or indirect photodegradation processes including H_{2}O_{2} photolysis or photo-Fenton reagents (H_{2}O_{2}/ Fe^{3+} ). Examples of the application of these methods to chlorophenoxy acid herbicides and four aromatic pesticides (bendiocarb, pirimiphos-methyl, …


Heavy Metal Contents Of Lake Sapanca, Nevi̇n Yalçin, Vahdetti̇n Sevi̇nç Jan 2001

Heavy Metal Contents Of Lake Sapanca, Nevi̇n Yalçin, Vahdetti̇n Sevi̇nç

Turkish Journal of Chemistry

The heavy metal pollution of Lake Sapanca located in the Marmara region (Turkey), was investigated over time. The lake is the drinking water source of the city of Adapazarı and its environs. The D-80 (TEM) motorway passes about 5 km along the lake's zero point in the Sapanca district. The motorway's wastewater drainages have been connected to the lake without having been subjected to any wastewater treatment. The motorway was opened to service in October 1990. Analyses were performed in 1991 and were repeated in 1999 in order to observe changes in Pb, Fe and Zn contents. Samples were collected …


Photocuring Of Acrylate Oligomers In The Presence Of Vinyl Phosphonic Acids As A Flame Retarding Monomer And The Properties Of The Cured Films, Tüli̇n İmamoğlu, Yusuf Yağci Jan 2001

Photocuring Of Acrylate Oligomers In The Presence Of Vinyl Phosphonic Acids As A Flame Retarding Monomer And The Properties Of The Cured Films, Tüli̇n İmamoğlu, Yusuf Yağci

Turkish Journal of Chemistry

Photocuring of formulations containing polyurethane based acrylates and a flame retarding monomer (FR), namely vinyl phosphonic acid with an \alpha -cleavage type photoinitiator; 2-hydroxy-2-methylphenyl propane-1-one were studied. The flame retardancy, and the physical and mechanical properties of the cured films were determined.


Determination Of Hydrochlorothiazide And Enalapril Maleate In Tablet Formulations By Reversed-Phase Hplc, Idrees F. Al-Momani̇ Jan 2001

Determination Of Hydrochlorothiazide And Enalapril Maleate In Tablet Formulations By Reversed-Phase Hplc, Idrees F. Al-Momani̇

Turkish Journal of Chemistry

A high-performance liquid chromatographic procedure is presented for the determination of hydrochlorothiazide (HCT) and enalapril maleate (EM) in pharmaceutical tablets. An aliquot of the sample is dissolved in 15% acetonitrile (ACN) containing thiophylline as an internal standard and chromatographed on a Supelcosil LC-8 (5 \mu m), (150 mm x 4.6 mm i.d.) column. The mobile phase was 3.0 mM tetrabutylammoniumhydrogen sulfate (TBAHS) in ACN/water/triethylamine (TEA), (14, 85.6, 6.4 V/V) adjusted to pH 4.1 by glacial acetic acid. The detection was at 220 nm. The method was tested for linearity, accuracy, recovery, and specificity.


The Composition Of Essential Oils From Two Varieties Of Sideritis Erythrantha Var. Erythrantha And Var. Cedretorum, Nurhayat Tabanca, Neş'E Kirimer, K. Hüsnü Can Başer Jan 2001

The Composition Of Essential Oils From Two Varieties Of Sideritis Erythrantha Var. Erythrantha And Var. Cedretorum, Nurhayat Tabanca, Neş'E Kirimer, K. Hüsnü Can Başer

Turkish Journal of Chemistry

Water distilled essential oils from two varieties of Sideritis erythrantha: var. erythrantha} and var. cedretorum, both endemic in Turkey, were analysed by GC/MS. The main components were characterized as \alpha -pinene (16.3-19.5%) and sabinene (6.1- 10.4%) for var. erythrantha; myrcene (21.9-24.3%) and \alpha -pinene (11.4- 12.4%) for var. cedretorum.


Investigation Of The Microporous And Mesoporous Structures Of The Reşadiye (Tokat/Turkey) Bentonite And Its Fractions, Müşerref Önal, Yüksel Sarikaya, Tülay Alemdaroğlu Jan 2001

Investigation Of The Microporous And Mesoporous Structures Of The Reşadiye (Tokat/Turkey) Bentonite And Its Fractions, Müşerref Önal, Yüksel Sarikaya, Tülay Alemdaroğlu

Turkish Journal of Chemistry

It was determined by X-ray diffraction that, besides containing clay minerals such as montmorillonite and illite, the original bentonite contained also clinoptilolite, opal-C, quartz, calcite and dolomite. The original bentonite was separated into four fractions by decantation and precipitation from its aqueous suspension. The adsorption and desorption of nitrogen on the original bentonite and its fractions at 77 K were investigated. The specific surface areas of the samples were determined according to the methods of Brunauer-Emmett-Teller, de Boer-Lippens, and Harkins-Jura by using the adsorption data. The mesopore size distribution curves were plotted by using the desorption data. The specific micropore …


Towards The Asymmetric Synthesis Of Ascochlorin, Özdemi̇r Doğan, Wolfgang Oppolzer Jan 2001

Towards The Asymmetric Synthesis Of Ascochlorin, Özdemi̇r Doğan, Wolfgang Oppolzer

Turkish Journal of Chemistry

A synthetic approach is described to the asymmetric synthesis of ascochlorin (1), an antiviral antibiotic, based on the construction of a sesquiterpene unit via asymmetric Diels-Alder reaction of tigloyl sultam 4 & butadiene, and the introduction of the aromatic side chain (C9-C12 unit) by employing cuprate chemistry.


Determination Of Some Of The Physicochemical Properties Of Fine Alumina Powders Prepared By Emulsion Evaporation, Yüksel Sarikaya, İsmet Sevi̇nç, Müşerref Önal, Tülay Alemdaroğlu Jan 2001

Determination Of Some Of The Physicochemical Properties Of Fine Alumina Powders Prepared By Emulsion Evaporation, Yüksel Sarikaya, İsmet Sevi̇nç, Müşerref Önal, Tülay Alemdaroğlu

Turkish Journal of Chemistry

In order to prepare fine alumina powders, an emulsion was prepared under optimum conditions. The emulsion was examined by optical microscopy and the prepared fine alumina powders were characterised by electron microscopy. The particles were formed of porous spheres and their sizes were between 1 and 10 \\mum. The powder samples were sintered by varying the temperature between 700 and 1600°C. The adsorption and desorption of nitrogen on these samples were investigated. By using the adsorption data, the specific surface areas were calculated according to different procedures and the correlation between them was discussed. The specific micropore and mesopore volumes …


Adsorption Of Non-Ionic Surface Active Agent On Fine Coal And Lignite, Zeki̇ Aktaş Jan 2001

Adsorption Of Non-Ionic Surface Active Agent On Fine Coal And Lignite, Zeki̇ Aktaş

Turkish Journal of Chemistry

The adsorption of Triton X-100 in aqueous solution on the less than 53 \\mum size fractions of Tunçbilek lignite and Zonguldak bituminous coal was studied. The adsorption isotherms were formed for 5, 30 and 1,440 (equilibrium) minutes. The isotherms were evaluated using both Langmuir and Freundlich adsorption equations. Concentrations of the reagent in the monolayer after equilibrium adsorption were determined to be 8.17 and 7.27 \\muM/g coal for the lignite and bituminous coal using the Langmuir adsorption equation. The specific adsorption capacity per unit area of Zonguldak bituminous coal was 5.3 times higher than that of Tunçbilek lignite. The adsorption …


Evaluation Of Sample Pre-Treatment Procedures For The Determination Of Cr, Ni And V In Biological Matrices By Etaas, Jan Medved, Jana Kubova, Eva Chmielewska, Vladimir Stresko Jan 2001

Evaluation Of Sample Pre-Treatment Procedures For The Determination Of Cr, Ni And V In Biological Matrices By Etaas, Jan Medved, Jana Kubova, Eva Chmielewska, Vladimir Stresko

Turkish Journal of Chemistry

Electrothermal atomic absorption spectrometry (ETAAS) was applied for the determination of chromium, nickel and vanadium in biological materials (earthworms, feather, lucerne). Three different decomposition procedures of biological matrices are presented. The utilization of NH_4H_2PO_4, Mg(NO_3)_2 and Pd(NO_3)_2+ Mg(NO_3)_2 as chemical modifiers are investigated and compared. Optimal temperature conditions for the electrothermal determination of Cr, Ni and V are selected. Precision of the determination expressed as relative standard deviations for Cr, Ni and V varied from 6 to 22% . The detection limits are for Cr 8 \\mu g kg^{ - 1}, Ni 12 \\mu g kg^{ - 1}, and V …


Selenium Speciation In Karakaya Dam Lake's Water (Malatya-Turkey), F. Zehra Küçükbay, Mustafa Demi̇r Jan 2001

Selenium Speciation In Karakaya Dam Lake's Water (Malatya-Turkey), F. Zehra Küçükbay, Mustafa Demi̇r

Turkish Journal of Chemistry

Concentrations of total inorganic selenium, Se(IV), Se(VI) and organically bonded selenium from samples of Karakaya dam lake\\\'s water were determined using ammonium pyrollidine dithio carbamate (APDC) as a chelating agent and subsequent adsorption on amberlite type XAD-8 resins. Eluted analytes are taken up in a matrix free acidic solution suitable for graphite furnace atomic absorption spectroscopy (GFAAS). According to our results, levels of the total inorganic selenium, Se(IV), Se(VI) and organically bonded selenium were found to be between 0.11 \\pm 0.01 and 0.17 \\pm 0.01 \\mug/L, 0.07 \\pm 0.01 and 0.12 \\pm 0.01 \\mug/L, 0.02 \\pm 0.01 and 0.05 \\pm …


Calculation Of Multi-Center Integrals For The Region Of Moderate And Weak Overlap, Abdulhali̇k Karabulut, Gökhan Budak, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n Jan 2001

Calculation Of Multi-Center Integrals For The Region Of Moderate And Weak Overlap, Abdulhali̇k Karabulut, Gökhan Budak, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n

Turkish Journal of Chemistry

In this study a general formula was established for multi-center integrals over Gaussian basis sets using the two-center expansion of nuclear attraction and electron repulsion potentials. The terms of the formula are the analytical functions of interatomic distances. Three kinds of integrals contained in these formulae can be evaluated analytically. In the presented method, unlike many other popular methods, the numerical integrations procedure is unnecessary since it does not contain the incomplete gamma function. A computer program was written and tested for various orbitals. The calculations show that the series converge very rapidly.


Conductimetric And Potentiometric Titration Of Some Hydroxylated Cinnamic Acids With Tetrabutylammonium Hydroxide In Non-Aqueous Media, A.Hakan Aktaş, Gülsüm Yaşar, Güleren Özkan Alsancak, Şahi̇nde Demi̇rci̇ Jan 2001

Conductimetric And Potentiometric Titration Of Some Hydroxylated Cinnamic Acids With Tetrabutylammonium Hydroxide In Non-Aqueous Media, A.Hakan Aktaş, Gülsüm Yaşar, Güleren Özkan Alsancak, Şahi̇nde Demi̇rci̇

Turkish Journal of Chemistry

In this study, four hydroxycinnamic acids, namely 3,4-dihydroxycinnamic acid, 4-hydroxycinnamic acid, 4-hydroxy --3- methoxycinnamic acid and 4-hydroxy-3,5-dimethoxycinnamic acid, were titrated conductimetrically and potentiometrically using triethylamine and tetrabutylammonium hydroxide in acetonitrile, 2-propanol, and pyridine solvents under a nitrogen atmosphere at 25 ^oC. In conductimetric titration with tetrabutylammonium hydroxide all of the compounds exhibited conventional stoichiometric titration curves in 2-propanol . As is evident from the titration curves, all these compounds gave two well-defined end points. The first end point corresponds to exactly one equivalent and the second one to the two equivalents of the base. In conductimetric titration with tetrabutylammonium hydroxide, …


Surface Bundles: Some Interesting Examples, Jim Bryan, Ron Donagi, Andras I. Stipsicz Jan 2001

Surface Bundles: Some Interesting Examples, Jim Bryan, Ron Donagi, Andras I. Stipsicz

Turkish Journal of Mathematics

We show two constructions of surface bundles over Riemann surfaces admitting nonvanishing signatures.


Torus Fibrations On Symplectic Four-Manifolds, Ivan Smith Jan 2001

Torus Fibrations On Symplectic Four-Manifolds, Ivan Smith

Turkish Journal of Mathematics

This paper has two essentially unrelated halves. In the first we prove that a closed symplectic four-manifold admitting a fibration by connected, homologically essential Lagrangian tori with "tame" singularities, is fibre-preserving diffeomorphic to a K3 surface or to a torus bundle over a torus with first Betti number at least three. In the second, we prove that these torus bundles over tori admit Lefschetz pencils by genus three curves. It follows that the genus three mapping class group admits infinitely many inequivalent irreducible positive relations. Motivations for the questions are provided from mirror symmetry, integrable systems and Seiberg-Witten theory: in …


Sections Of Lefschetz Fibrations And Stein Fillings, Andras I. Stipsicz Jan 2001

Sections Of Lefschetz Fibrations And Stein Fillings, Andras I. Stipsicz

Turkish Journal of Mathematics

Using Eliashberg's theorem about Stein fillings of S^3 we prove that a section of a Lefschetz fibration over S^2 has nonnegative square. This observation, in particular, implies that the identity element 1\in \Gamma _g ^1 in the mapping class group of a genus-g surface with one boundary component cannot be written as a product of positive Dehn twists.


Floer Homology And Its Continuity For Non-Compact Lagrangian Submanifolds, Yong-Geum Oh Jan 2001

Floer Homology And Its Continuity For Non-Compact Lagrangian Submanifolds, Yong-Geum Oh

Turkish Journal of Mathematics

We give a construction of the Floer homology of the pair of vnon-compact Lagrangian submanifolds, which satisfies natural continuity property under the Hamiltonian isotopy that moves the infinity but leaves the intersection set of the pair compact. This construction uses the concept of Lagrangian cobordism and certain singular Lagrangian submanifolds. We apply this construction to conormal bundles (or varieties) in the cotangent bundle, and relate it to a conjecture made by MacPherson on the intersection theory of the characteristic Lagrangian cycles associated to the perverse sheaves constructible to a complex stratification on the complex algebraic manifold.


The Canonical Class Of A Symplectic Four Manifold, Ronald Fintushel, Ronald Stern Jan 2001

The Canonical Class Of A Symplectic Four Manifold, Ronald Fintushel, Ronald Stern

Turkish Journal of Mathematics

In this article we present examples of simply connected symplectic 4-manifolds X whose canonical classes are represented by complicated disjoint unions of symplectic submanifolds of X: Theorem. Given finite collections {g_i}, {m_i}, i=1,...,n, of positive integers, there is a minimal symplectic simply connected 4-manifold X whose canonical class is represented by a disjoint union of embedded symplectic surfaces K ~ S_{g_1,1} « ... « S_{g_1,m_1} « ... « S_{g_n,1} «... « S{g_n,m_n} where S_{g_i,j} is a surface of genus g_i. Furthermore, c_1^2(X) = c_h(X) - (2+ b) where b= S{i=1}^n m_i is the total number of connected components of the …


On The Tautological Ring Of \Bar{\Mathcal{M}}_{G,N}, Tom Graber, Ravi Vakil Jan 2001

On The Tautological Ring Of \Bar{\Mathcal{M}}_{G,N}, Tom Graber, Ravi Vakil

Turkish Journal of Mathematics

We prove that the dimension 0 part of the tautological ring of the moduli space of stable pointed curves is one-dimensional. This provides the first genus-free evidence for a conjecture of Faber and Pandharipande that the tautological ring of the moduli space is Gorenstein, answering in the affirmative a question of Hain and Looijenga.


Formula For The Highly Regularized Trace Of The Sturm-Liouville Operator With Unbounded Operator Coefficients Having Singularity, İnci̇ Albayrak, Oya Baykal, Erdal Gül Jan 2001

Formula For The Highly Regularized Trace Of The Sturm-Liouville Operator With Unbounded Operator Coefficients Having Singularity, İnci̇ Albayrak, Oya Baykal, Erdal Gül

Turkish Journal of Mathematics

In this work, a formula for the n^{th} regularized trace of the Sturm-Liouville operator with unbounded operator coefficients having singularity is obtained


On The Expansions In Eigenfunctions Of Hill's Operator, Fi̇li̇z Aras, Gusei̇n Sh Gusei̇nov Jan 2001

On The Expansions In Eigenfunctions Of Hill's Operator, Fi̇li̇z Aras, Gusei̇n Sh Gusei̇nov

Turkish Journal of Mathematics

In this paper we show how one can deduce the Titchmarsh expansion formula in eigenfunctions of Hill's operator from the Gel'fand expansion formula.


A Perturbed Version Of The Ostrowski Inequality For Twice Differentiable Mappings, A. Sofo, S. S. Dragomir Jan 2001

A Perturbed Version Of The Ostrowski Inequality For Twice Differentiable Mappings, A. Sofo, S. S. Dragomir

Turkish Journal of Mathematics

A generalisation of a perturbed version of the Ostrowski inequality for twice differentiable mappings is studied. It is shown that the error bounds are better than those obtained previously. Applications for general quadrature formulae are also given.


On Qr-Submanifolds Of A Quaternionic Space Form, Bayram Şahi̇n Jan 2001

On Qr-Submanifolds Of A Quaternionic Space Form, Bayram Şahi̇n

Turkish Journal of Mathematics

In this paper, we investigate mixed QR-submanifolds in a quaternionic space form and pseudo umbilical QR-submanifold of a quaternionic space form under some additional condition. Finally we give a necessary condition for QR-submanifold of a quaternion Kaehler manifold such that \dim \upsilon ^{\perp }=1 to be a 3-quasi Sasakian Manifold.