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Articles 10141 - 10170 of 10230
Full-Text Articles in Physical Sciences and Mathematics
On Homogeneous Riemann Boundary Value Problem, K. Kutlu
On Homogeneous Riemann Boundary Value Problem, K. Kutlu
Turkish Journal of Mathematics
In this work we consider homogeneous Riemann boundary value problem (BVP) on general open rectifiable curves. We prove certain estimates for Cauchy type integrals in terms of local moduli of continuity and local maximum of modulus, which allow us to describe the solvability of Riemann BVP with unbounded oscillating coefficients on a wide class of non-smooth rectifiable Jordan curves.
On Strongly Regular Rings, A. Kaya, F. Kuzucuoğlu
On Strongly Regular Rings, A. Kaya, F. Kuzucuoğlu
Turkish Journal of Mathematics
Some characterizations of strongly regular rings will be given. Let R be a ring and I(\neq R) a right ideal of R. If, for each pair of right ideals A and B of R, AB \subseteq I implies that either A \subseteq I or B \subseteq I, then I is called a prime right ideal (or equivalently, if aRb \ \ \not\subseteq I whenever a and b do not belong to I). I is strongly prime right ideal if, for each pair of a and b in R, aIb \subseteq I and ab \in I imply that either a \in …
Weak\Star- Invariantly Complemented Subspaces Of L^{\Infty}(1/\Omega) And Ideals Of L^{1}(\Omega) With A Bounded Approximate Identity, Z. Argün, C. Tonyali
Weak\Star- Invariantly Complemented Subspaces Of L^{\Infty}(1/\Omega) And Ideals Of L^{1}(\Omega) With A Bounded Approximate Identity, Z. Argün, C. Tonyali
Turkish Journal of Mathematics
For a locally compact group G let L^{1}(\omega) be the weighted group algebra and let X be a weak \star-closed translation invariant subspace of L^{\infty} (1/\omega). In this paper for a certain class of functions we show that the following conditions are equivalent: (i) X is topological invariantly complemented in L^{\infty}(1/\omega); (ii) X is invariantly complemented in L^{\infty}(1/\omega); (iii) The left ideal X_{\perp} has a bounded right approximate identity.
Extension Of Caristi-Kirk's Theorem, M. O. Diallo, M. Oudadess
Extension Of Caristi-Kirk's Theorem, M. O. Diallo, M. Oudadess
Turkish Journal of Mathematics
We give some extensions and/or improvements, to uniform spaces and to multi-valued mappings, of Caristi-Kirk's theorem.
Normal Boundary Value Problems For Differential Equations Of Higher Order, F. G. Maksudov, Z. I. Ismailov
Normal Boundary Value Problems For Differential Equations Of Higher Order, F. G. Maksudov, Z. I. Ismailov
Turkish Journal of Mathematics
In this work the arbitrary order differential operator expression of the form \imath (u) = \frac{\partial u (t)}{\partial t^n}+Au(t), where A is a bounded normal operator in the Hilbert Space H is considered in the Hilbert Space of vector functions L_2(H(0,1)). This paper describes all normal boundary value problem for the indicated diferential expression in terms of abstnract boundary conditions and determines a connection with other typea of boundary value problems.
T_2-Objects In Categories Of Filter And Local Filter Convergence Spaces, M. Baran
T_2-Objects In Categories Of Filter And Local Filter Convergence Spaces, M. Baran
Turkish Journal of Mathematics
There are various generalizations of the usual T_2 (Hausdorff) axiom of topology to an arbitrary topological category defined in [1]. In this paper, four more new generalizations of Hausdorff spaces are given in the topological categories. Moreover, the relationships among all of these T_2 structures and the ones given in [5] and [7] as well as some invariance properties of them are investigated in the categories of filter and local filter convergence spaces. Keywords: Topological Categories, T_2-objects, Filter Convergence Spaces.
On Conformally Flat Lorentzian Spaces Satisfying A Certain Condition On The Curvature Tensor, M. Erdoğan
On Conformally Flat Lorentzian Spaces Satisfying A Certain Condition On The Curvature Tensor, M. Erdoğan
Turkish Journal of Mathematics
In this paper we prove a local classification theorem for the conformally flat lorentzian spaces satisfying the condition R(X,Y)R=0.
On The Additive Group Structure Of Nonstandard Models Of Z, Ç. Gencer, M. Terzi̇ler
On The Additive Group Structure Of Nonstandard Models Of Z, Ç. Gencer, M. Terzi̇ler
Turkish Journal of Mathematics
Let \hat{Z} denote the inverse limit of finite cyclic groups and F_gZ the group where $F$ is a vector space over Q and + is defined by (a, x)+(b, y)=(a+b, x+y+g(a,b)) for some g: F\times F\rightarrow Z. In this paper we show that any nonstandard model Z^{\star} of Z is isomorphic to F_{\beta}Z for some \beta: F\rightarrow \hat{Z} where F=Z^{\star}/Z.
A Note On Double Sequences Of Fuzzy Numbers, E. Savaş
A Note On Double Sequences Of Fuzzy Numbers, E. Savaş
Turkish Journal of Mathematics
In this paper we introduce double convergent sequences of fuzzy numbers and we also study the space of double convergent sequences of fuzzy numbers.
Rings In Which Strongly Prime Right Ideals Are Finitely Generated, A. Kaya
Rings In Which Strongly Prime Right Ideals Are Finitely Generated, A. Kaya
Turkish Journal of Mathematics
Some properties of rings in which every strongly prime right ideal is finitely generated will be investigated, and sufficient conditions for such rings to be right noetherian will be given. Let R be an s-unital ring (i.e., a\in aR\cap Ra for each a\in R) and I(\neq R)a right ideal of R. If, for each right ideals A and B of R, AB\subseteq I implies that either A\subseteq I or B\subseteq I, then I is called a prime right ideal (or equivalently, if a\, R\,b \not\subseteq I whenever a and b do not belong to I). I is strongly prime if, …
Relations Between Classes Of Dragilev Spaces (F_1)_{\Sigma} And (F_2)_{\Sigma} For Arbitrary Function F^{-1}_{1}\Circ F_2}, V. Kashirin, A. Vakulenko
Relations Between Classes Of Dragilev Spaces (F_1)_{\Sigma} And (F_2)_{\Sigma} For Arbitrary Function F^{-1}_{1}\Circ F_2}, V. Kashirin, A. Vakulenko
Turkish Journal of Mathematics
Necessary and sufficient condition under wich Dragilev classes (f_1)_{\sigma} and (f_2)_{\sigma} coincide have been found for an arbitrary function f^{-1}_{1}\circ f_2.
A Property Of Meldrum Groups, A. O. Asar, S. Atlihan
A Property Of Meldrum Groups, A. O. Asar, S. Atlihan
Turkish Journal of Mathematics
In this work it is shown that the direct product of two Meldrum groups does not satisfy the normalizer condition. It is not known yet if the same result holds true for any two HM-groups.
The Group Structure Of Hecke Groups H(\Lambda_Q), İ. N. Cangül
The Group Structure Of Hecke Groups H(\Lambda_Q), İ. N. Cangül
Turkish Journal of Mathematics
In this work a new proof of the fact that the group structure of the Hecke groups is isomorphic to the free product of two cyclic groups of orders 2 and q is given The method used in the proof requires a result of A.M. Macbeath together with the notion of fundamental region. Also given are some new results on the parabolic points of Hecke groups, which still is an open problem.
Absolutely Representing Systems And Convolution Operators In The Complex Domain, Yu. F. Korobeinik
Absolutely Representing Systems And Convolution Operators In The Complex Domain, Yu. F. Korobeinik
Turkish Journal of Mathematics
The author suggests a method of characterizing of the kernel of a convolution-type operator. The method is based on the exact description of nontrivial expansions of zero of an absolutely representing system consisting of eigen vectors of some linear operator with continuous spectrum. The method suggested in the paper is applied to the characterization of the kernel of the convolution-type operator defined on some space of entire functions and to the factorization of such an operator.
(\Sigma, \Tau)- Lie Ideals In Prime Rings With Derivation, M. Soytürk
(\Sigma, \Tau)- Lie Ideals In Prime Rings With Derivation, M. Soytürk
Turkish Journal of Mathematics
Let R be a prime ring, char R\neq 2,3 \, \sigma, \tau : R\rightarrow R two automorphisms, U a nonzero (\sigma, \tau)- Lie ideal of R and o\neq d : R\rightarrow R$ a derivation such that \sigma d = d\sigma, \tau d = d\tau. In this paper we have proved the following results. (1) If d (U) \subset Z then U\subset Z (2) If d(U) \subset U and d^2 (U) \subset Z then U\subset Z.
Linear Topologic Invariants And Their Applications To Isomorphic Classification Of Generalized Power Spaces, V. Zahariuta
Linear Topologic Invariants And Their Applications To Isomorphic Classification Of Generalized Power Spaces, V. Zahariuta
Turkish Journal of Mathematics
In the present survey generalized linear topological invariants are considered as a development of classical invariants of Kolmogorov and Pelczynski (approximative and diametral dimensions). It is realized a geometric idea to construct some new invariant characteristics by applying of classical characteristics (diameter or entropy-like characteristics) to some symplest interpolational constructions under neighborhoods, taken from a given basis of neighborhoods of zero. It is considered various applications to isomorphic classification of generalized power K\"{o}the spaces (in particular, tensor products of finite and infinite type power series spaces, spaces of analytic and infinitely differentiable vector-valued functions, spaces of analytic functions of several …
On Homotopic, Non--Isomorphic Tight Contact Structures On 3-Manifolds, Paolo Lisca, Gordana Matic
On Homotopic, Non--Isomorphic Tight Contact Structures On 3-Manifolds, Paolo Lisca, Gordana Matic
Turkish Journal of Mathematics
No abstract provided.
A Survey Of Symplectic 4-Manifolds With B^+ = 1, Dusa Mcduff, Dietmar Salamon
A Survey Of Symplectic 4-Manifolds With B^+ = 1, Dusa Mcduff, Dietmar Salamon
Turkish Journal of Mathematics
No abstract provided.
Removable Singularities And A Vanishing Theorem For Seiberg-Witten Invariants, Dietmar Salamon
Removable Singularities And A Vanishing Theorem For Seiberg-Witten Invariants, Dietmar Salamon
Turkish Journal of Mathematics
No abstract provided.
Higher Genus Symplectic Invariants And Sigma Model Coupled With Gravity, Yongbin Ruan, Gang Tian
Higher Genus Symplectic Invariants And Sigma Model Coupled With Gravity, Yongbin Ruan, Gang Tian
Turkish Journal of Mathematics
No abstract provided.
Akbulut's Corks And H-Cobordisms Of Smooth, Simply Connected 4-Manifolds, Rob Kirby
Akbulut's Corks And H-Cobordisms Of Smooth, Simply Connected 4-Manifolds, Rob Kirby
Turkish Journal of Mathematics
No abstract provided.
On Affine Selection And Separation Of Vector Valued Functions, S. Alpay, Z. Ercan
On Affine Selection And Separation Of Vector Valued Functions, S. Alpay, Z. Ercan
Turkish Journal of Mathematics
Let K be a Choquet simplex, E a Fr\'{e}chet space and \Phi: K \ra 2^E a map such that \Phi(x) is closed and convex for each x \in K. A sufficient condition is given for \Phi to have a continuous affine selection.This is employed to prove a separation theorem for vector valued semicontinuous functions from a Choquet simplex into an ordered Fr\'{e}chet space.
Zeros Of Derivatives Of Dirichlet L-Functions, C. Yalçin Yildirim
Zeros Of Derivatives Of Dirichlet L-Functions, C. Yalçin Yildirim
Turkish Journal of Mathematics
In this paper diverse results on the location and number of zeros of derivatives of Dirichlet L-functions are proved.
Chelate Ring-Closure Kinetics Of Cr(Co)_5 (Dppm) Studied By ^{31}P-Nmr Spectroscopy, Saim Özkar, Ceyhan Kayran, Ayşin Tekkaya
Chelate Ring-Closure Kinetics Of Cr(Co)_5 (Dppm) Studied By ^{31}P-Nmr Spectroscopy, Saim Özkar, Ceyhan Kayran, Ayşin Tekkaya
Turkish Journal of Chemistry
^{31}P-NMR spectroscopy was used to study the kinetics of the chelate ring-closure reaction in CR(CO)_5 (DPPM) where DPPM is bis (diphenylphosphino) methane. DPPM is potentially a bidentate ligand, but in this complex it is coordinated to the transition metal in a monodentate fashion and therefore can undergo chelation. The thermal chelate ring-closure reaction was carried out in an NMR sample tube at a constant temperature and the course of the reaction was quantitatively followed by taking ^{31}P-NMR spectra in appropriate time intervals. Kinetic results have shown that the chelate ring-closure reaction of Cr(CO)_5 DPPM is of zero-order. Activation parameters were …
The Investigation Of Aluminum Sulfate-Potassium Chloride Solid Phase Reaction, İ. Ayhan Şengi̇l
The Investigation Of Aluminum Sulfate-Potassium Chloride Solid Phase Reaction, İ. Ayhan Şengi̇l
Turkish Journal of Chemistry
It was found that aluminum sulfate reacts with potassium chloride to produce K_{2}SO_{4}, Al_{2}O_{3}, and Cl_{2} in the solid phase at 700 ^{\circ}C. This reaction was investigated with thermal analysis under air and nitrogen atmosphere. By changing temperature and time parameters, the actual yield of conversion in question was examined analytically and the optimum temperature and time were found for the reaction. The rate expression of the solid phase reaction was also investigated and the rate equation was obtained.
Analysis Of Retention In Supercritical Fluid Chromatography And Its Relation To Solubility, Z. Şermin Gönenç, Uğur Akman, Aydın K. Sunol
Analysis Of Retention In Supercritical Fluid Chromatography And Its Relation To Solubility, Z. Şermin Gönenç, Uğur Akman, Aydın K. Sunol
Turkish Journal of Chemistry
The effects of temperature, pressure and supercritical fluid density on the solubility-retention relationship of solutes in supercritical fluid chromatography are investigated. New retention data for naphthalene, phenanthrene, benzoic acid and 2-methoxy-naphthalene is obtained as a function of pressure at different temperatures. The bulk of the data is taken near the critical region of the mobile gas where the anomalities are expected. This data is used to compare two approaches for thermodynamic modeling of pressure dependence of solute retention. In these approaches, mobile-phase partial molar volumes of the solutes are determined either from bulk solubility data or from infinite-dilution fugacity coefficients. …
Quantum-Chemical Investigations On The Functionalized 1h-Pyrimidines, İsmail Yildirim, Makbule Tezcan, Yahya Güzel, Emin Saripinar, Yunus Akçamur
Quantum-Chemical Investigations On The Functionalized 1h-Pyrimidines, İsmail Yildirim, Makbule Tezcan, Yahya Güzel, Emin Saripinar, Yunus Akçamur
Turkish Journal of Chemistry
Conformational analysis and quantum-chemical calculations were carried out by means of the methods MMP2 and SCF MO LCAO in the CNDO/2 and MNDO approximation for the series of compounds being functionalized 1H- pyrimidines. The analysis of the electron density distribution depending on the substituents' nature was done on the basis of the data obtained.
Transmission Electron Microscopy (Tem) Study Of Polycrystalline Ru:Ag/Alumina Supported Catalyst System., S. Tajammul Hussain
Transmission Electron Microscopy (Tem) Study Of Polycrystalline Ru:Ag/Alumina Supported Catalyst System., S. Tajammul Hussain
Turkish Journal of Chemistry
Transmission Electron Microscopy (TEM) was used to characterize bimetallic Ru/Ag Catalyst samples dispersed on a high surface area Alumina support. The addition of Ag increases the metal dispersion but no consistent trend is observed. Ag forms crystallites of various shape and sizes, some of them are present in the close vicinity of Ru but not forming Ru:Ag bimetallics. A part of Ag crystallites cover the Ru surface hence blocking Ru emission. These irregular shaped crystallites are possibly responsible for the increase in metal dispersion. Particles below 2.5 nm were Ag particles, between 2.5 to 5.0 nm were Ru:Ag mixed crystallites …
Investigation Of Acid Sites On V_{2}O_{5}/Tio_{2}(A) Catalysts By Ftir With Adsorption Of Pyridine, Ahmet Akbaş, Holger Mi̇tzel, Dieter Höni̇ce
Investigation Of Acid Sites On V_{2}O_{5}/Tio_{2}(A) Catalysts By Ftir With Adsorption Of Pyridine, Ahmet Akbaş, Holger Mi̇tzel, Dieter Höni̇ce
Turkish Journal of Chemistry
The V_{2}O_{5}/TiO_{2}(A) catalysts were prepared by the grafting and their Br\"{o}nsted and Lewis acid sites were investigated with pyridine adsorption by using FTIR Spectroscopy. The results obtained showed that monolayer or less coverage of the surface of the support, TiO_{2}(A), took place up to V_{2}O_{5} content of 11.88 \%. When V_{2}O_{5} amount was higher then 11.88 \%, the support was covered as multilayer. Pyridine adsorption studies showed that the number of the Lewis acid sites of the V_{2}O_{5}/TiO_{2}(A) catalysts decreased with increasing of V_{2} O_{5} amount. The number of the Br\"{o}nsted acid sites increased with increasing V_{2}O_{5} content, reached a …
Poly (D,L-Lactic Acid) Homopolymers: Synthesis And Characterization, Xu Kaitian, Ahmet Kozluca, Emir B. Denkbaş, Erhan Pi̇şki̇n
Poly (D,L-Lactic Acid) Homopolymers: Synthesis And Characterization, Xu Kaitian, Ahmet Kozluca, Emir B. Denkbaş, Erhan Pi̇şki̇n
Turkish Journal of Chemistry
In this study, poly(D,L-lactic acid or D,L-lactide) (PDLLA) homopolymers were synthesized with different molecular weights. Low molecular weight PDLLAs (MW_n: 500-2300) were synthesized by direct polycondensation of DL-lactic acid without using any catalyst, while high molecular weight PDLLAs ( MW_n: 8x10^3-150x10^3) were produced by ring-opening polymerization of DL-lactide with stannous chloride as catalyst (initiator). Average molecular weights of PDLLAs were determined by end-group analysis, by viscosimetric measurements and by HPLC. PDLLA homopolymers were characterized by FTIR, NMR and DSC. In the production of PDLLAs by direct polymerization, molecular weights of the PDLLAs increased with the increase in the polymerization time …