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Articles 10411 - 10440 of 10730
Full-Text Articles in Physical Sciences and Mathematics
Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov
Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov
Turkish Journal of Physics
Magnetization of MeFe$_2$Se$_4$ (Me = Ti; V; Cr; Fe; Co; Ni) compounds at low temperatures has been investigated. It is shown that these compounds are ferrimagnetics with low values of specific magnetization. It is established that along the crystal axis $c$ of a given compound, there have been carried out two types of exchange interactions; cation-cation and cation-anion-cation with different dependence of their quantity on interatomic distance.
The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli
The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli
Turkish Journal of Physics
DC conductivity has been measured as function of dopant concentration for Se-As glass containing 2-10 \% As, doped with Cl or Br. It was established that concentration dependences of the conductivity have maxima for concentration of Cl or Br between $10^{-3}$ and $10^{-2}$ at \%. The effect of halogen impurities on electroconductivity of Se-As glasses has been attributed to the change of relative concentrations of the charged defect centers $(C^-_1, C^+_3)$ and to the occurrence of new $Cl^-, Br^-$ centers associated with chlorine (bromine) atoms and the compensation of the effect of arsenic on the energy spectrum of electron states.
Shallow Donors In A Quantum Well Wire; Electric Field And Geometrical Effects, M. Ulaş, H. Akbaş, M. Tomak
Shallow Donors In A Quantum Well Wire; Electric Field And Geometrical Effects, M. Ulaş, H. Akbaş, M. Tomak
Turkish Journal of Physics
Subband and shallow donor binding energies are calculated. The emphasis is given on the electric field effects for wires of different shapes. It is shown that the donor binding energy is sensitive to the interplay of the electric field and geometrical effects.
\Tau->\Rho\Nu Decay And Leptonic Decay Constants Of Vector Mesons, Kh. Ablakulov, B.N. Kuranov, T.Z. Nasyrov
\Tau->\Rho\Nu Decay And Leptonic Decay Constants Of Vector Mesons, Kh. Ablakulov, B.N. Kuranov, T.Z. Nasyrov
Turkish Journal of Physics
The new Salpeter equation for vector mesons is proposed and the representation for their leptonic decay constants is obtained.
Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar
Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar
Turkish Journal of Physics
We study the resonance production of new particles predicted by preonic models at Linac-Ring type $ep$ and $\gamma p$ colliders. It is shown that these machines will allow to investigate the new particles with masses up to few TeV scale.
Determination Of Temperature Dependent Frequency Factor Constant From Tl Glow Curves, A. Necmeddin Yazici
Determination Of Temperature Dependent Frequency Factor Constant From Tl Glow Curves, A. Necmeddin Yazici
Turkish Journal of Physics
A new method solely based on the theoretical and experimental analysis of thermoluminescence glow curves is proposed for the determination of the temperature dependent frequency factor constant.
Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇
Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇
Turkish Journal of Physics
$CdTe, CdS$ thin films and $n-CdS/p-CdTe$ heterostructures have been prepared by conventional vacuum evaporation technique. Some post deposition treatments to optimize the device efficiency have been analyzed and the effects of the individual process steps on the material and device properties were investigated. Annealing in air with and without $CdCl_2$-treatment decreased the $CdTe$ resistivity. The $CdCl_2$-dip followed by annealing in air at $300^{\circ}C$ for 5 min improved the grain size and polycrystalline nature of $CdTe$ thin films. Solar efficiency improvements were achieved when heterojunctions were prepared on successively treated (i.e. etched, air annealed, $CdCl_2$-processed) $CdTe$ surfaces. Etching of the $CdTe$ …
Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov
Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov
Turkish Journal of Physics
The structure of ceramic materials containing molibdenum powder is considered within the framework of leakage theory. Determined are the density of the endless cluster, volumetric parts of the skeleton and dead ends, as well as their dependence on the component concentration. Volumetric part of the skeleton near the threshold of leakage makes a negligible part of the full volume.
Delay Time Fluctuations Of The Tunnel Josephson Junction In The Case Of Linearly Growing Current, Iman Novruzoglu Askerzade
Delay Time Fluctuations Of The Tunnel Josephson Junction In The Case Of Linearly Growing Current, Iman Novruzoglu Askerzade
Turkish Journal of Physics
Delay time thermal fluctuations intensity of the tunnel Josephson junction for the case of high current rate is calculated.
A New Probe Head Design For The Weak Field Double Resonance Spectrometer, A. Oral Salman, M. Maral Sünnetçi̇oğlu, Rıza Sungur, Gökçe Bi̇ngöl
A New Probe Head Design For The Weak Field Double Resonance Spectrometer, A. Oral Salman, M. Maral Sünnetçi̇oğlu, Rıza Sungur, Gökçe Bi̇ngöl
Turkish Journal of Physics
In order to observe low field $\sigma$ EPR spectra of free radicals a new probe head was designed to work at 1.53 mT. As a double resonance spectrometer, at 1.53 mT the probe head includes both NMR and EPR rf coils. To induce the $\sigma$ transitions EPR rf coil must produce an rf field parallel to the main static field. Various coil designs were examined for this aim and the best results was obtained with a solenoid NMR coil and saddle shaped single turn EPR coil design combination.
Characterization Of Spray Deposited Bismuth Oxide Thin Films From Non-Aqueous Medium, V.V. Killedar, C.H. Bhosale, C.D. Lokhande
Characterization Of Spray Deposited Bismuth Oxide Thin Films From Non-Aqueous Medium, V.V. Killedar, C.H. Bhosale, C.D. Lokhande
Turkish Journal of Physics
Bismuth oxide thin films have been prepared on amorphous glass substrates from non-aqueous medium using spray pyrolysis method. Characterization of the films was carried out with XRD, optical absorption, dark resistivity and thermoelectric power (TEP) measurements. These studies reveal that films as deposited are polycrystalline; having an optical band gap of 2.6 eV; electrical resistivity is of the order of $10^6$ ohm-cm; and electron carrier concentration and mobility are of the order of $3.8 \times 10^{19}$cm$^3$ and $1.5 \times 10^{-4}$cm$^2$ V$^{-1}$s$^{-1}$, respectively.
Analysis Of Atmospheric Concentrations Of Radon And Thoron Using Beta Counting Technique, G. S. Islam, S. M. Basunia
Analysis Of Atmospheric Concentrations Of Radon And Thoron Using Beta Counting Technique, G. S. Islam, S. M. Basunia
Turkish Journal of Physics
This paper presents a detailed theory and experimental procedure for measurement and analysis of mixed radon and thoron in the environment. The technique has been successfully applied to the study of seasonal variations of radon and thoron in the atmosphere around Rajshahi, Banladesh, during the years 1989-1991. The maximum radon concentration in outdoor air was observed in the winter from December to January while the indoor radon concentration was found to be maximum during the monsoon months of July and August. The implication of the results is briefly discussed in the paper.
A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra
A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra
Turkish Journal of Physics
The differential cross sections for elastic scattering of ^{16}O from ^{20}Ne have been calculated using an optical potential and distorted wave Born approximation (DWBA) calculations. In the present calculations several prescriptions were tried in the ion-ion potential. The DWBA calculations were performed employing folded real and Woods-Saxon optical potentials for the distorted waves. Inclusion of the exchange process explains the large back-angle cross sections. The elastic scattering differential cross sections are successfully described by calculations in which elastic alpha-transfer amplitudes are coherently added to direct elastic scattering amplitudes.
Effect Of Deposition Conditions On Composition Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste
Effect Of Deposition Conditions On Composition Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste
Turkish Journal of Physics
The effect of rf-magnetron sputtering conditions on as-deposited film composition using a stoichiometric Bi_2Sr_2CaCu_2O_y (Bi-2212) target was investigated in an on-axis configuration, as the stoichiometrical control of the film is the most important parameter for the proper study of film characteristics. It was found that substrate target distance up to 55-60 mm may provide a film composition close to the target composition. The sputtering chamber pressure effecting film composition, especially in respect of Bi, is an important parameter which needs very pracise control. Bi ratio in the deposited films increases with increasing Ar pressure while Sr and Ca are not …
Flavour Violating \Tau-Decays In Magnetic Interaction And E_6 Models, A.T. Alan, Z.Z. Aydin And S. Sultansoy
Flavour Violating \Tau-Decays In Magnetic Interaction And E_6 Models, A.T. Alan, Z.Z. Aydin And S. Sultansoy
Turkish Journal of Physics
In the view of future c-\tau-factories, we report an analysis of the rare decays of the \tau lepton via \tau \to \mu e \overline{e}, \tau \to e \mu \overline{\mu}, \tau \to \mu \mu \overline{\mu} and \tau \to ee \overline{e} in the two models, i.e., in Barut's magnetic interaction model (MIM) and in an E_6 model proposed by Gürsey and his collaborators. The energy distributions of one of the final leptons are given for both models. Numerical estimates reveal that these decays can be as large as 10^{-6}, which may be observed in LEP experiments or at other c-\tau factories.
Quantum Integrable Systems Of The Group Su(1, 1), Mehmet Sezgi̇n, Yılmaz Asad Verdi̇yev
Quantum Integrable Systems Of The Group Su(1, 1), Mehmet Sezgi̇n, Yılmaz Asad Verdi̇yev
Turkish Journal of Physics
Quantum integrable systems related with SU(1, 1) group manifold or hyperboloid [x, x] = x^2_1 + x^2_2 - x^2_3 - x^2_4 = 1 in spherical, hyperbolic and parabolic coordinates systems are considered. The explicit expressions for waves functions, spectra and S-matrices are given.
Object-Oriented Computer Simulations Of Physical Systems Using Dual Reciprocity Boundary Element Methodology, J. Friedrich
Object-Oriented Computer Simulations Of Physical Systems Using Dual Reciprocity Boundary Element Methodology, J. Friedrich
Turkish Journal of Electrical Engineering and Computer Sciences
Models of physical systems are essential in every engineering field. This work deals with computer simulations of physical systems that can be mathematically modelled by differential equations together with sufficient boundary conditions. The computer simulations are based on object-oriented technology and the dual reciprocity boundary element method which is a universal solution scheme for various types of partial differential equations (e.g. Laplace, Poisson, diffusion, convection-diffusion, and steady Navier-Stokes equation). This technique fulfills efficiency criteria like precision, robustness, versatility, programmability, user-friendliness, need of computational time and computer memory to a very high degree. This is demonstrated by three examples: Laplace's solution …
Distribution System Planning Usign Mixed Integer Programming, Belgin Türkay
Distribution System Planning Usign Mixed Integer Programming, Belgin Türkay
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents an improved mathematical model to optimise the size and locations of substations and the network routing problem. The model was formulated to minimise the total cost of the network by determining the optima of the substation locations and power, the load transfers between the demand centers, the feeder routes and the load flow in the network subject to a set of constraints. The computational results of a devised sample problem indicate that the developed optimisation model and its code are adequate for computer aided planning of distribution systems.
Analysis Of Nonlinear Sustained Oscillations In Discrete Systems With Backlash And Resolution By Using A Discretization-Oriented Describing Function, M. De La Sen, A. Pena, J. Esnaola
Analysis Of Nonlinear Sustained Oscillations In Discrete Systems With Backlash And Resolution By Using A Discretization-Oriented Describing Function, M. De La Sen, A. Pena, J. Esnaola
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a discretization-oriented describing function is derived for nonlinear devices combining backlash and quantization (resolution) while being subject to discretization through a sampler and zero-order hold. Such a describing function is frequency-dependent so that the overall nonlinearity, which includes both resolution and backlash, is interpreted as possessing nonlinear inertia. That nonlinear inertia is generated by the sampling process, since it does not appear if the system is continuous. The presence of nonlinear sustained oscillations (limit cycles) is investigated through simulations.
Signal Injection With Perceptual Criteria, T. Engi̇n Tuncer
Signal Injection With Perceptual Criteria, T. Engi̇n Tuncer
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a novel method for increasing the coding performance and information transmission capacity is presented. This method is mainly based on perceptual modelling of input signal such as speech or audio. Presented approach may be seen as an alternative to transforms which dynamically change analysis window for better energy compaction. A perceptual model is established in order to obtain a global masking threshold in frequency below which sounds become inaudible. Certain criteria are developed for identifying the signal injection bands. A new multiband filter design method which is a generalization of windowing method is used to separate the …
State Of Art In Realistic Head Modeling For Electro-Magnetic Source Imaging Of The Human Brain, Nevzat G. Gençer, İ. Oğuz Tanzer, M. Kemal Özdemi̇r, Can E. Acar, Mert Sungur
State Of Art In Realistic Head Modeling For Electro-Magnetic Source Imaging Of The Human Brain, Nevzat G. Gençer, İ. Oğuz Tanzer, M. Kemal Özdemi̇r, Can E. Acar, Mert Sungur
Turkish Journal of Electrical Engineering and Computer Sciences
Electric currents produced by the neural activity in the brain create electric potentials on the scalp and magnetic field distribution outside the scalp. Measuring electric and magnetic fields provides a means to understand the spatio-temporal distribution of the neural activity. The representations of the intracellular electric current of active cell populations based on bimodal data are called electro-magnetic source image (EMSI). With the recent development of large arrays of magnetic sensors, and systems for measuring scalp voltages at more than 100 locations, it is now feasible to implement computational methods that employ numerical models which incorporate the correct geometry and …
The Tachibana Operator And Transfer Of Lifts, Abdullah Mağden, Muhammet Kamali, Arif A. Salimov
The Tachibana Operator And Transfer Of Lifts, Abdullah Mağden, Muhammet Kamali, Arif A. Salimov
Turkish Journal of Mathematics
The main purpose of this paper is to investigate, using the Tachibana operator, transfer of the complete lifts of affinor structures along the cross-sections of the tangent and cotangent bundles.
Study Of Magnetic Non-Uniformities In Yttrium-Iron Garnet By The Measuring Method Of Magneto-Optical Susceptibility, Komil Mukimov, Odil Ochilov, Makhset Khalmuratov, Asror Ramazanov, Ulpash Mirzakulova
Study Of Magnetic Non-Uniformities In Yttrium-Iron Garnet By The Measuring Method Of Magneto-Optical Susceptibility, Komil Mukimov, Odil Ochilov, Makhset Khalmuratov, Asror Ramazanov, Ulpash Mirzakulova
Turkish Journal of Physics
Study of magnetic non-uniformities in yttrium-iron garnet by the measuring in method of magneto-optical susceptibility in laser beam with the wave length of \lambda = 1.15 \mu m.
A Phase Diagram Of The Nematic, Smectic A And Smectic C Phases In Liquid Crystals, S. Sali̇hoğlu, H. Yurtseven
A Phase Diagram Of The Nematic, Smectic A And Smectic C Phases In Liquid Crystals, S. Sali̇hoğlu, H. Yurtseven
Turkish Journal of Physics
In this study we have obtained a phase diagram for the nematic, smectic A and smectic C phases in liquid crystals. For this phase diagram we have studied two different mean field models for a mixture of liquid crystalline system. In our first model we consider the NC and AC transitions as first order, and the NA transition as a second order. In our second model we consider the NC and NA transitions as first order, and the AC transition as a second order.
A Mean Field Model For The Coexistence Of Nematic, Smectic A And Smectic C Phases In Liquid Crystals, H. Yurtseven, S. Sali̇hoğlu
A Mean Field Model For The Coexistence Of Nematic, Smectic A And Smectic C Phases In Liquid Crystals, H. Yurtseven, S. Sali̇hoğlu
Turkish Journal of Physics
We present here a mean field model for the nematic-smectic A-smectic C coexistence of a liquid crystal near the NAC point which is a multicritical point. The critical exponents calculated from our model are tricritical expoenents for the order parameters, susceptibility and the specific heat. Our results show that if the NAC point is the tricritical point, then our mean field model describes adequately the liquid crystalline system in the coexistence region of the nematic-smectic A-smectic C phases.
Timelike Ruled Surfaces In The Minkowski 3-Space-Ii, A. Turgut, H. H. Hacisali̇oğlu
Timelike Ruled Surfaces In The Minkowski 3-Space-Ii, A. Turgut, H. H. Hacisali̇oğlu
Turkish Journal of Mathematics
This paper is devoted to a study of timelike ruled surfaces in three dimensional Minkowski space obtained by a spacelike straight line moving along a timelike curve. The central point, the curve of striction and the distribution parameter of a timelike ruled surface in Minkowski 3-space are considered, and some theorems relating to their structure are obtained. In addition, some results about developable timelike ruled surfaces are also given.
About Some Classical Functional Equations, Nicolae Neamtu
About Some Classical Functional Equations, Nicolae Neamtu
Turkish Journal of Mathematics
The purpose of this paper is to give a new method of finding the solution of Lobashevsky's functional equation and those of other classical functional equations. At the beginning we present the properties of solution $f, \; f \neq 0$, of Lobachevsky's functional equation. Using only the boundedness property on $(-r, r)$, we deduce the continuity, convexity and differentiability properties of the solution.
An Improper Integral Representation Of Linnik's Probability Densities, A. (Bastiyali) Hayfavi̇
An Improper Integral Representation Of Linnik's Probability Densities, A. (Bastiyali) Hayfavi̇
Turkish Journal of Mathematics
A representation of Linnik's Probability Densities by a contour integral distinct than the one given in [2] is obtained. An Improper integral representation of the same density functions is derived. An investigation into the exceptional set is achieved as well.
The Origin Of Clay Minerals In Salina Playa-Mudflat Facies,Yeniçubuk Formation (Lower-Middle Miocene), Gemerek, Sivas, Türkiye, İbrahim Türkmen, Cemal Bölücek
The Origin Of Clay Minerals In Salina Playa-Mudflat Facies,Yeniçubuk Formation (Lower-Middle Miocene), Gemerek, Sivas, Türkiye, İbrahim Türkmen, Cemal Bölücek
Turkish Journal of Earth Sciences
The playa-mudflat facies under investigation are found in the Gemerek Basin (Sivas, Türkiye). This Miocene basin is bordered by the Akdağ Metamorphics (Paleozoic) to the N-NW, the Elmalıdağ Volcanic Rocks (Thanetian) to the E and clastic rocks and evaporites of the Cevizcik Formation (Oligocene) to the S-SW. Illite, palygorskite, smectites (montmorillonite, saponite and sauconite), chlorite (clinochlore) and serpentines had been studied using XRD analysis of mudstone samples. Illites and chlorites were found to have originated from marble, schists, granitic rocks, dioritic rocks and syenitic rocks of Akdağ Massif to the north. Palygorskite were formed in evaporitic basins by chemical sedimantation. …
Geochemistry And Origin Of The Oligocene Binkılıç Manganese Deposit;Thrace Basin, Turkey, Ali Haydar Gülteki̇n
Geochemistry And Origin Of The Oligocene Binkılıç Manganese Deposit;Thrace Basin, Turkey, Ali Haydar Gülteki̇n
Turkish Journal of Earth Sciences
Many Oligocene Manganese deposits are found in the Trace basin, a Tertiary collisional-collapse type basin in the northwestern part of Turkey. All the mineralizations are originally sedimentary type. The most economically important deposits are around Çatalça; of these, the Binkılıç manganese ore occurs conformably within the Oligocene fossiliferous formations, as a stratiform type manganese deposit. The manganese ores at Binkiliç show a continuity along strike and consists of micro-to Cryptocrystalline pyrolusite, psilomelane, radial manganite, cryptomelane, wad, rhodochrosite and dispersed organic matter, calcite, feldspar, clay minerals, and quartz but generally only minor quantities of limonite and goethite. Mn oxides with variable …