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Articles 9271 - 9300 of 10317
Full-Text Articles in Physical Sciences and Mathematics
Cation Distribution And Magnetisation Study Of Nd^{+3} Substituted Zn-Mg Ferrites, B. P. Ladgaonkar, P. N. Vasambekar, A. S. Vaingankar
Cation Distribution And Magnetisation Study Of Nd^{+3} Substituted Zn-Mg Ferrites, B. P. Ladgaonkar, P. N. Vasambekar, A. S. Vaingankar
Turkish Journal of Physics
Polycrystalline ferrites Zn_{x}Mg_{1-x}Fe_{2-y}Nd_{y}O_{4} (x = 0.00, 0.20, 0.40, 0.80 and 1.00; y = 0.00, 0.05 and 0.10) were prepared by standard ceramic method. Thecompositions,oncharacterisation by X-ray diffraction, shows formation of single phase cubic spinels. Magnetic measurement of these composition shows increase in magnetic moment n_{\beta} with Zn^{2+} concentration up to x = 0.4 and decreases thereafter. This is attributed to the existence of locallised canted spin. The compositions for x = 0.8 and 1.0 shows paramagnetic behaviour at and above room temperature. The trivalent substitution of Nd^{3+} ion causes reduction in the magnetic moment. The cation distribution of the sytem …
Electrical Characterization Of Gate And Gate:Cu Semiconductor Compounds, Hüsnü Sali̇h Güder, Bahatti̇n Abay, Hasan Efeoğlu, Cevdet Coşkun, Şaki̇r Aydoğan, Yahya Kemal Yoğurtçu
Electrical Characterization Of Gate And Gate:Cu Semiconductor Compounds, Hüsnü Sali̇h Güder, Bahatti̇n Abay, Hasan Efeoğlu, Cevdet Coşkun, Şaki̇r Aydoğan, Yahya Kemal Yoğurtçu
Turkish Journal of Physics
Electrical properties of GaTe and GaTe:Cu binary compound semiconductors were investigated by Hall effect and resistivity measurements in the 77-320 K temperature range. Donor and acceptor densities, compensation ratios, acceptor ionization energies, valence band effective mass of holes and effective density of states in valence band were determined for the undoped and Cu doped samples using the single donor-single acceptor analysis of the hole concentration. Temperature coefficient of the hole mobility was determined and compared with related theories.
Urbach-Martienssen's Tail In Layered Ternary Semiconductor Tlgas_{2}, Bahatti̇n Abay, Hüsnü Sali̇h Güder, Hasan Efeoğlu, Yahya Kemal Yoğurtçu
Urbach-Martienssen's Tail In Layered Ternary Semiconductor Tlgas_{2}, Bahatti̇n Abay, Hüsnü Sali̇h Güder, Hasan Efeoğlu, Yahya Kemal Yoğurtçu
Turkish Journal of Physics
Dependence of the absorption coefficient on the photon energy and temperature near the fundamental absorption edge was measured for layered single crystal TlGaS_{2}. The exponentially increasing absorption tail was explained as an Urbach-Martienssen's (U-M's) tail for TlGaS_{2} samples in the 10-340 K temperature range. The characteristic Urbach's parameters such as steepness parameter [\sigma (T)] and Urbach's energy [(E_{u} = k_{B} T / \sigma )] were determined. Analyzing the temperature dependence of these parameters based on the general models, which takes into account the possible role of several different types of disorder, we conclude that the absorption process in the fundamental …
Determination Of The Trapping Parameters Of Glow Peaks Of Caf2:Dy(Tld-200) By Using Computer Glov Curve Deconcolution Method, A. Necmeddi̇n Yazici, M. Yakup Hacii̇brahi̇moğlu
Determination Of The Trapping Parameters Of Glow Peaks Of Caf2:Dy(Tld-200) By Using Computer Glov Curve Deconcolution Method, A. Necmeddi̇n Yazici, M. Yakup Hacii̇brahi̇moğlu
Turkish Journal of Physics
Computerized glow curve deconvolution method is used to determine the number of peaks, the order of kinetics b, the activation energy E_a,frequency factor s and number of the trapped electrons n_0 associated with the glow peaks in single crystal of CaF_2:Dy (TLD-200). Glow curve analysis indicate that the glow curve in the temperature region between room temperature and 250 ^oC can be best described as a superposition of six peaks. First five peaks are described by first-order kinetics and sixth peak general-order kinetic. The number of trapped electrons, activation energies and frequency factor for individual glow peaks are as follows: …
Preparation Of Pb Doped 110 K Phase Bisrcacuo Thick Films By Screen Printing, Ertan Şahi̇n, Necdet Baştürk
Preparation Of Pb Doped 110 K Phase Bisrcacuo Thick Films By Screen Printing, Ertan Şahi̇n, Necdet Baştürk
Turkish Journal of Physics
Thick Films of Bi_2Sr_2Ca_2Cu_3O_x were obtained on cleaved MgO (100) substrates from a component gel of stoichiometric composition with partial Pb substitution of Bi. Formation employeed screen printing method. Films were subjected two step annealing at temperatures above 850^oC and 880^\oC for the formation of the crystal structure and to attain superconducting properties. X-ray diffraction patterns and R-T measurements showed coexistence of the (2212) and (2223) phases for most of the films. Metallic behaviour in resistance and 110 K onset temperature were observed for good quality films with a completed superconducting transition between 78-103 K. Critical current densities were found …
The Investigation Of The Thermoluminescence Emission Bands Of Lif:Mg,Ti (Tld-100) By A Simple Developed Model, A. Necmeddi̇n Yazici, Z. Öztürk, M. Bedi̇r
The Investigation Of The Thermoluminescence Emission Bands Of Lif:Mg,Ti (Tld-100) By A Simple Developed Model, A. Necmeddi̇n Yazici, Z. Öztürk, M. Bedi̇r
Turkish Journal of Physics
In this study, a new simple model based on the classical treatment of lattice vibrations and the Franck-Condon principle is developed to describe the shape of thermoluminescence (TL) emission bands of crystalline solids. According to developed model, shape of the emission band has a Gaussian form and depends on just two physical parameters: peak energy E_{0} and broadening of emission spectra U. In order to demonstrate the success of the developed model, the emission spectra of dosimetric material LiF:Mg,Ti (TLD-100) was also measured. Then, a computerised best-fit program including the developed model was used to analyse the emission spectra. The …
Is There An Age Of The Universe Problem After The Hipparcos Data?, Murat Özer
Is There An Age Of The Universe Problem After The Hipparcos Data?, Murat Özer
Turkish Journal of Physics
We have reanalyzed the age of the universe problem under the assumption that the lower limit on the age of the globular clusters is \sim11 Gyr, as predicted by the recent Hipparcos data. We find that the globular cluster and the expansion ages in a standard \lambda=0 universe are consistent only if the present value H_0 of the Hubble constant is \leq 60{\rm kms}^{-1}Mpc^{-1}. If H_0>60{\rm kms}^{-1}Mpc^{-1} some kind of modification of the standard \lambda=0 model is required. Invoking a (time-independent) cosmological term \lambda in the Einstein field equations, as has been done frequently before, we have found that …
Path Integral Treatment For Spinless Relativistic Equation In The Two Component Theory, M. Merad, T. Boudjedaa, Lyazid Chetouani
Path Integral Treatment For Spinless Relativistic Equation In The Two Component Theory, M. Merad, T. Boudjedaa, Lyazid Chetouani
Turkish Journal of Physics
In this paper we have set up a path integral formalism for Feshbach-Villars equation by using the fermionic Schwinger model for Pauli matrices which describe an isocharge symmetry. This choice is made in analogy with spin model and the coherent state representation is then used. We have also given a general method of treating the problem of vanishing scalar potential by reducing it the to non-relativistic case and then, via Foldy-Wouthuysen canonical transformation, an explicit solution is constructed. The free case and constant magnetic field interaction are explicitly exposed. In each cases the propagators are evaluated and the energy spectrum …
Vacuum Cryostat's Pressure Dependent Dark Conductivity Measurements On A-Si:H And A-Sin:H Films, İlker Ay, Hüseyi̇n Tolunay
Vacuum Cryostat's Pressure Dependent Dark Conductivity Measurements On A-Si:H And A-Sin:H Films, İlker Ay, Hüseyi̇n Tolunay
Turkish Journal of Physics
The electrical properties of a-Si:( H ) and a- SiN ):( H ) films prepared by plasma deposition from SiH_4+NH_3 gas mixtures have been investigated. We observed anomalous peaks in the temperature dependent dark conductivity curves of annealed a-Si:H and a-SiN:H samples when the temperatures were increased from 90 K to room temperature at a constant heating rate. To study the surface adsorption effect, vacuum cryostat pressure dependence of these peaks are investigated. We have also studied the effect of nitrogen on these observed peaks in dark conductivity.
A Correlation Of Thin Lens Approximation To Thick Lens Design By Using Coddington Factors In Lens Design And Manufacturing, Ömer Faruk Farsakoğlu, D. Mehmet Zengi̇n, Hi̇kmet Kocabaş
A Correlation Of Thin Lens Approximation To Thick Lens Design By Using Coddington Factors In Lens Design And Manufacturing, Ömer Faruk Farsakoğlu, D. Mehmet Zengi̇n, Hi̇kmet Kocabaş
Turkish Journal of Physics
The effect of Coddington factors on aberration functions has been analysed using thin lens approximation. Minimizing spherical aberrations of singlet lenses using Coddington factors in lens design depending on lens manufacturing is discussed. Notation of lens test plate pairs used in lens manufacturing is also presented in terms of Coddington shape factors.
Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n
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.
Schrödinger Equation Solutions For Small R And Resulting Functional Relations, Harry A. Mavromatis
Schrödinger Equation Solutions For Small R And Resulting Functional Relations, Harry A. Mavromatis
Turkish Journal of Physics
The Schrödinger equation is examined for small r (i.e. one step beyond the limit r \rightarrow 0) for the cases V(r) \rightarrow r^k, (k>0), and V(r) \rightarrow r^{-k} (0
Photospheric Line Profiles In Deneb (A2 Iae), Berahi̇tdi̇n Albayrak, Cemal Aydin, Dursun Koçer
Photospheric Line Profiles In Deneb (A2 Iae), Berahi̇tdi̇n Albayrak, Cemal Aydin, Dursun Koçer
Turkish Journal of Physics
In this study, the strong lines were examined to determine the effect of velocity gradient due to mass loss on the line profiles in the atmosphere of Deneb. The lines are formed in the optical depth range -1.14 < log \tau < -0.14. None were found to exibit any asymmetry.
A Theoretical Model For The Non-Linear Susceptibility Of The Antiferromagnetic Systems, Beki̇r Özçeli̇k, Keri̇m Kiymaç, Ahmet Eki̇ci̇bi̇l
A Theoretical Model For The Non-Linear Susceptibility Of The Antiferromagnetic Systems, Beki̇r Özçeli̇k, Keri̇m Kiymaç, Ahmet Eki̇ci̇bi̇l
Turkish Journal of Physics
In this study, we have developed a general theoretical model, based upon the simple mean field model of N\'{e}el, for the non-linear response of an antiferromagnetic system. The results indicate that the odd order derivatives, (d^{2n + 1}m_{a})_{0} = (-d^{2n + 1}m_{b})_{0}, where n=1,2,3......, will diverge and the even order derivatives, (d^{2n}m_{a})_{0} = (d^{2n}m_{b})_{0} will vanish due to the symmetry of two sublattices, ``a'' and ``b'', forming the antiferromagnet. This model also supports our experimental results performed on two antiferromagnetic samples, namely, Cs_{2}MnCl_{4}.2H_{2}O and MnCl_{2}.4H_{2}O [1].
Symplectic Maps To Projective Spaces And Symplectic Invariants, Denis Auroux
Symplectic Maps To Projective Spaces And Symplectic Invariants, Denis Auroux
Turkish Journal of Mathematics
After reviewing recent results on symplectic Lefschetz pencils and symplectic branched covers of \CP^2, we describe a new construction of maps from symplectic manifolds of any dimension to \CP^2 and the associated monodromy invariants. We also show that a dimensional induction process makes it possible to describe any compact symplectic manifold by a series of words in braid groups and a word in a symmetric group.
The Topology Of Symplectic Manifolds, Robert E. Gompf
The Topology Of Symplectic Manifolds, Robert E. Gompf
Turkish Journal of Mathematics
A topological structure is introduced that seems likely to provide a complete topological characterization of compact symplectic manifolds. The article begins with a leisurely introduction to symplectic manifolds from a topological viewpoint. It then focuses on Thurston's construction of a symplectic structure on the total space of a fiber bundle. This is generalized to a technique for putting a symplectic structure on the domain of a J-holomorphic map. A topological structure called a hyperpencil on a compact 2n-manifold is then defined; this is motivated by the special case of a linear system of curves on an algebraic manifold, and it …
Surface Bundles: Some Interesting Examples, Jim Bryan, Ron Donagi, Andras I. Stipsicz
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
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 …
Floer Homology And Its Continuity For Non-Compact Lagrangian Submanifolds, Yong-Geum Oh
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.
A Partial Order On The Group Of Contactomorphisms Of $\R^{2n+1}$ Via Generating Functions, Mohan Bhupal
A Partial Order On The Group Of Contactomorphisms Of $\R^{2n+1}$ Via Generating Functions, Mohan Bhupal
Turkish Journal of Mathematics
In this note we construct a nontrivial partial order on the identity component of the group of compactly supported contactomorphisms of \R^{2n+1} using the method of generating functions. Our construction is in the framework of the theory developed by Viterbo in the paper \cite{V} wherein, among other things, he showed how one could use generating functions to construct a partial order on the group of compactly supported Hamiltonian symplectomorphisms of \R^{2n}.
Knotting Of Algebraic Curves In Complex Surfaces, Sergey Finashin
Knotting Of Algebraic Curves In Complex Surfaces, Sergey Finashin
Turkish Journal of Mathematics
For any d\ge 5, I constructed infinitely many pairwise smoothly non-equivalent surfaces F\subset\Cp{2} homeomorphic to a non-singular algebraic curve of degree d, realizing the same homology class as such a curve and having abelian fundamental group \pi_1(\Cp2\stmin F). It is a special case of a more general theorem, which concerns for instance those algebraic curves, A, in a simply connected algebraic surface, X, which admit irreducible degenerations to a curve A_0, with a unique singularity of the type X_9, and such that A\cite A>16.
Topological Quantum Field Theory And Hyperkähler Geometry, Justin Sawon
Topological Quantum Field Theory And Hyperkähler Geometry, Justin Sawon
Turkish Journal of Mathematics
Rozansky and Witten proposed a 3-dimensional sigma-model whose target space is a hyperkähler manifold. They conjectured that this theory has an associated TQFT, with vector spaces given by certain cohomology groups of the hyperkähler manifold. On the other hand, there is a certain modified TQFT constructed by Murakami and Ohtsuki using the universal quantum invariant. We explain how the Rozansky-Witten TQFT can be obtained from the latter by applying a "hyperkähler weight system".
Induced Cat^1-Groups, Murat Alp
Induced Cat^1-Groups, Murat Alp
Turkish Journal of Mathematics
In this paper we define the pullback cat^1-group and show that this Pullback has a right adjoint which is the induced cat^1-group. Later we show that this right adjoint is a pushout of category of cat^1-groups. We calculate the Peiffer subgroups to find a finite group of the source of induced cat^1-groups. The generating set of Peiffer subgroups are also given in this paper. All results are corrected by a GAP[13] program package in [4]. This paper also contains the some computational examples which are the calculation-induced cat^1-group and comparative times between the induced crossed modules and induced cat^1-groups.
P -Banach Algebras With Generalized Involution And C^*-Algebra Structure, Abdellah El Kinani, Aziz Ifzarne, Mohamed Oudadess
P -Banach Algebras With Generalized Involution And C^*-Algebra Structure, Abdellah El Kinani, Aziz Ifzarne, Mohamed Oudadess
Turkish Journal of Mathematics
In this paper, we consider p-Banach algebras endowed with a generalized involution. We show that various C^*-like conditions force the algebra to be C^*-algebra under an equivalent norm.
Inequalities For The Vibrating Clamped Plate Problem, Kimberley Mchale, Ünal Ufuktepe
Inequalities For The Vibrating Clamped Plate Problem, Kimberley Mchale, Ünal Ufuktepe
Turkish Journal of Mathematics
We study the eigenvalues of the vibrating clamped plate problem. We have made improvements on the bounds of the ratios of the eigenvalues of the biharmonic operator (clamped plate) using the methods of Payne, Polya, and Weinberger. The difference in our proof lies mainly with the trial functions and the orthogonality arguments. While Payne, Polya, and Weinberger and Hile and Yeh project away components along u_1,u_2,...,u_k to meet the orthogonality conditions,we use a translation/rotation argument to meet these conditions.
A Perturbed Version Of The Ostrowski Inequality For Twice Differentiable Mappings, A. Sofo, S. S. Dragomir
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 The L^P Solutions Of Dilation Equations, İbrahi̇m Kirat
On The L^P Solutions Of Dilation Equations, İbrahi̇m Kirat
Turkish Journal of Mathematics
In this paper, the concepts concerning the space of constant breadth were extended to E^n-space. An approximate solution of the equation system which belongs to this curve was obtained. Using this solution vectorial expression of the curves of constant breadth was obtained. The relation \int_0^{2\pi}\widetilde{f}(s)\,ds=0 between the curvatures of curves of constant breadth in E^n was obtained. Key Words and Phrases: Curvature, Constant Breadth, Integral Characterization of Curve"> MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']], displayMath: [['\\[','\\]'], ['$$','$$']]}}); Academic Journals Find Manuscript Copyright Release Form Copyright Release Form(Turkey) Copyright Release Form(Other Countries) Manuscript Submission and Evaluation System On the L^p Solutions of Dilation …
Some Characterization Of Curves Of Constant Breadth In E^N Space, Zülfi̇gar Akdoğan, Abdullah Mağden
Some Characterization Of Curves Of Constant Breadth In E^N Space, Zülfi̇gar Akdoğan, Abdullah Mağden
Turkish Journal of Mathematics
In this paper, the concepts concerning the space of constant breadth were extended to E^n-space. An approximate solution of the equation system which belongs to this curve was obtained. Using this solution vectorial expression of the curves of constant breadth was obtained. The relation \int_0^{2\pi}\widetilde{f}(s)ds=0 between the curvatures of curves of constant breadth in E^n was obtained. Key Words and Phrases: Curvature, Constant Breadth, Integral Characterization of Curve
Fuzzy Maximal Ideals Of Gamma Near-Rings, Young Bae Yun, Kyung Ho Kim, Mehmet Ali̇ Öztürk
Fuzzy Maximal Ideals Of Gamma Near-Rings, Young Bae Yun, Kyung Ho Kim, Mehmet Ali̇ Öztürk
Turkish Journal of Mathematics
Fuzzy maximal ideals and complete normal fuzzy ideals in \Gamma-near-rings are considered, and related properties are investigated.
On The Lebesgue Measure Of Self-Affine Sets, İbrahi̇m Kirat
On The Lebesgue Measure Of Self-Affine Sets, İbrahi̇m Kirat
Turkish Journal of Mathematics
Flaherty and Wang studied Haar-type multiwavelets and multi-tiles. The information on what digit sets give multi-attractors with positive Lebesgue measure is very limited. In this note, we give a few classes of digit sets leading to multi-attractors with positive measure. The attractors we obtain include the Haar-type multi-tiles of Flaherty and Wang.