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- Electromagnetic transition (3)
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Dwba Of The Reaction ^0be(P, \Alpha )^6li At E_P = 18.6\Sim 50 Mev, S. E. Abdel-Kariem
Dwba Of The Reaction ^0be(P, \Alpha )^6li At E_P = 18.6\Sim 50 Mev, S. E. Abdel-Kariem
Turkish Journal of Physics
The compound nucleus produced in the reaction ^9Be(p, \alpha)^6Li in the incident energy range E_p = 18.6 \sim 50 MeV is mainly occurred when its excitation energy is greater than the \alpha -particle threshold separation energy by about 20 MeV, strongly suggesting the reaction mechanism is a direct one-step process. To understand this phenomenon, we employ semi-microscopic zero-range distorted-wave Born approximation (DWBA) theory to analyse experimental data obtained in this energy range for the lower three ^6Li-states: ground state (1^+; 0); 2.186 MeV (3^+; 0); and 3.563 MeV (0^+; 1). The Kurath-Millener spectroscopic-factor amplitudes for the triton-cluster transfer are used …
Optical Pulse Distortion In Fibonacci-Class Multilayer Stacks, A Rostami, S. Matloub
Optical Pulse Distortion In Fibonacci-Class Multilayer Stacks, A Rostami, S. Matloub
Turkish Journal of Physics
Optical pulse distortion and propagation through quasi-periodic structures generally and especially for Fibonacci-class, is investigated analytically and simulated numerically. In this analysis, the transfer matrix method (TMM) for distortion evaluation is used. The simulated results for Fibonacci-class quasi-periodic structures and pure periodic multilayer stacks are compared. We show that the Fibonacci-class quasi-periodic structure has a large dispersion coefficient with respect to a similar case in the periodic structure. So, quasi-periodic structures will destroy the incident pulse shape for smaller stack length than a periodic case in a similar situation. Finally, using output power, the distortion limit can be estimated and …
Transient Photoconductivity In Amorphous Se-Ge-Ag System, R. S. Sharma, D. Kumar, A. Kumar
Transient Photoconductivity In Amorphous Se-Ge-Ag System, R. S. Sharma, D. Kumar, A. Kumar
Turkish Journal of Physics
Transient Photoconductivity measurements have been made in vacuum evaporated thin films of Se_{0.80 - x}Ge_{0.20}Ag_x at different intensities, temperatures and illumination times. The films exhibit long-lived residual photoconductivity, called persistent photoconductivity, with an extremely slow decay rate. The persistent photoconductivity (PPC) increases with an increase in intensity and illumination time. However, this quantity decreases with increase in temperature. These results indicate that the decay of photoconductivity is not only governed by the carrier trapped in the intrinsic defects but also gets affected by the light induced defect creation through structural changes The persistent photoconductivity effect is found to be suppressed …
Stagnation Point Flow And Heat Transfer Of A Micropolar Fluid In A Porous Medium, Hazem Ali Attia
Stagnation Point Flow And Heat Transfer Of A Micropolar Fluid In A Porous Medium, Hazem Ali Attia
Turkish Journal of Physics
The steady laminar flow in a porous medium of an incompressible non-Newtonian micropolar fluid impinging on a permeable flat plate with heat transfer is investigated. A numerical solution for the governing nonlinear momentum and energy equations is obtained. The effect of the porosity of the medium and the characteristics of the non-Newtonian fluid on both the flow and heat transfer is presented and discussed.
A Treatment Of A Higher-Order Singular Lagrangian As Fields System, N. I. Farahat, M. R. Heles
A Treatment Of A Higher-Order Singular Lagrangian As Fields System, N. I. Farahat, M. R. Heles
Turkish Journal of Physics
The higher-order singular Lagrangian system is treated as field system. Euler-Lagrange equations are solved with some constraints. An example is studied and a comparison with Hamiltonian formulation is done.
Tunneling-Enhanced Recombination In Polycrystalline Cds/Cdte Solar Cells, Habi̇be Bayhan
Tunneling-Enhanced Recombination In Polycrystalline Cds/Cdte Solar Cells, Habi̇be Bayhan
Turkish Journal of Physics
The dominant dark current transport mechanism in as-grown and CdCl_2 processed CdS/CdTe heterojunction solar cells for temperatures below 300~K was investigated. The current-voltage properties of these solar cells is explained via tunnelling enhanced bulk and interface recombination models which give a quantitative description of the electronic loss mechanisms in the chalcopyrite-based heterojunction solar cells. The temperature dependence of the saturation current and the diode ideality factors of the as-grown and CdCl_2 processed CdTe solar cells are shown to be well described by this model.
Cherenkov Radiation In Homogeneous Isotropic Chiral Media, Pierre Hillion
Cherenkov Radiation In Homogeneous Isotropic Chiral Media, Pierre Hillion
Turkish Journal of Physics
We present a Fourier transform analysis of Cherenkov radiation for a point charge uniformly moving inside a 2D-homogeneous, isotropic, unbounded, chiral medium endowed with the Drude-Born-Fedorov constitutive relations when the chirality parameter ß and the wave number k make negligible the ß^2k^2 terms. The electromagnetic field is not described in terms of circularly right and left polarized waves but in terms of TM and TE components. The Cherenkov radiation arises when the velocity v of the point charge is greater than the phase velocity c/n, where n is the refractive index of the chiral medium and the electromagnetic field stands …
Assessment Of Wind Power Potential For Coastal Areas Of Pakistan, M. Akhlaque Ahmed, Firoz Ahmed, M. Wasim Akhtar
Assessment Of Wind Power Potential For Coastal Areas Of Pakistan, M. Akhlaque Ahmed, Firoz Ahmed, M. Wasim Akhtar
Turkish Journal of Physics
Selected coastal areas of Pakistan (Karachi, Ormara, Jivani and Pasni) were studied for the possibility of wind energy generation, using available meteorological data. Wind speed pattern, Extractable Wind power, Wind Energy and associated Weibull parameter for these coastal areas have been examined. The analysis also includes seasonal changes in wind speed values. The power output using fast and slow wind machines using different blade diameters have been estimated to explore the possible use for irrigation deep well pumping and small scale power generation. Along with this, 4 KW and 20 KW aero generators were also examined. It was found that, …
Ensemble Teleportation, Thomas Krüger
Ensemble Teleportation, Thomas Krüger
Turkish Journal of Physics
The possibility of teleportation is by sure the most interesting consequence of quantum non-separability. So far, however, teleportation schemes have been formulated by use of state vectors and considering individual entities only. In the present article the feasibility of teleportation is examined on the basis of the rigorous ensemble interpretation of quantum mechanics (not to be confused with a mere treatment of noisy EPR pairs) leading to results which are unexpected from the usual point of view.
Effect Of Thermal Annealing On The Band Gap And Optical Properties Of Chemical Bath Deposited Znse Thin Films, F. I. Ezema, A. B. C. Ekwealor, R. U. Osuji
Effect Of Thermal Annealing On The Band Gap And Optical Properties Of Chemical Bath Deposited Znse Thin Films, F. I. Ezema, A. B. C. Ekwealor, R. U. Osuji
Turkish Journal of Physics
Zinc selenide (ZnSe) thin films were deposited on glass substrate using the chemical bath deposition method at room temperature from aqueous solutions of zinc sulphate and sodium selenosulfate in which sodium hydroxide was employed as complexing agents. The `as-deposited' ZnSe thin films are red in color and annealed in oven at 473 K for 1 hour and on a hot plate in open air at 333 K for 5 minutes, affecting the morphological and optical properties. Optical properties such as absorption coefficient \alpha and extinction coefficient k, were determined using the absorbance and transmission measurement from Unico UV-2102 PC spectrophotometer, …
Phase Distribution Of The Output Of Jaynes-Cummings Model With The Superposition Of Squeezed Displaced Fock States, Gamal Mohamed Abd Al-Kader
Phase Distribution Of The Output Of Jaynes-Cummings Model With The Superposition Of Squeezed Displaced Fock States, Gamal Mohamed Abd Al-Kader
Turkish Journal of Physics
The Wigner quasi-probability function for the superposition of squeezed displaced Fock states (SDFS's) is reviewed. The interaction of these states with a two-level atom in cavity with the presence of additional Kerr medium is studied. Exact general matrix elements of the time-dependent operators of a Jaynes-Cummings model (JCM), in the presence of a Kerr medium, with these states are derived. We have obtained the phase distribution by two different ways: one is by Pegg-Barnett formalism, the second is by integration of the Wigner function over the radial variable. Results of these two approaches are compared. The Wigner phase distributions for …
Modulated Photoconductivity Studies Of A-As_2se_3 Thin Films, Ruhi̇ Kaplan
Modulated Photoconductivity Studies Of A-As_2se_3 Thin Films, Ruhi̇ Kaplan
Turkish Journal of Physics
Modulated photocurrent measurements in amorphous arsenic triselenide (a-As_2Se_3) is reported. Particular focus is paid towards photocarrier lifetimes as a function of temperature, and applied electric field (i.e. dc) were determined by using the quadrature frequency-resolved spectroscopy method. The activation energy from the photocurrent as a function of temperature was determined to be about 125 meV for a constant illumination intensity of 2.3 mW. Its value was found to be almost independent of the applied electric field. The exponent \nu in the power law relationship (I_{ph} \propto G^v) between generating flux and photocurrent was obtained under different electric fields. The electric …
Electrical Switching Behaviour In Lead Phosphovanadate Glasses, B. Sujatha, C. Narayana Reddy
Electrical Switching Behaviour In Lead Phosphovanadate Glasses, B. Sujatha, C. Narayana Reddy
Turkish Journal of Physics
Electrical switching behaviour of lead phosphovanadate glasses were studied by determining the current-voltage characteristics. All the investigated glasses exhibit the dependence of threshold voltages on temperature, thickness and composition. Below holding current the I - V characteristics obey Ohms law followed by a negative resistance region where the bulk behaviour dominates and at higher values of current the samples goes to a low resistance state. The studied glasses exhibit memory type switching. It is suggested that the initial switching and channel formation are due to electronic, while thermal effects dominate in the formation of channels.
Equivariant Localization For Susy Quantum Mechanics, Levent Akant
Equivariant Localization For Susy Quantum Mechanics, Levent Akant
Turkish Journal of Physics
We apply equivariant localization to supersymmetric quantum mechanics and show that the partition function localizes on the instantons of the theory. Our construction of equivariant cohomology for SUSY quantum mechanics is different than the ones that already exist in the literature. A hidden bosonic symmetry is made explicit and the supersymmetry is extended. New bosonic symmetry is the square of the new fermionic symmetry. The D term is now the parameter of the bosonic symmetry. This construction provides us with an equivariant complex together with a Cartan differential and makes the use of localization principle possible.
Plane Symmetric Solutions Of Gravitational Field Equations In Five Dimensions, A. N. Aliev, Hakan Cebeci̇, Teki̇n Dereli̇
Plane Symmetric Solutions Of Gravitational Field Equations In Five Dimensions, A. N. Aliev, Hakan Cebeci̇, Teki̇n Dereli̇
Turkish Journal of Physics
We present the effective field equations obtained from a generalized gravity action with Euler-Poincaré term and a cosmological constant in a D dimensional bulk space-time. A class of plane-symmetric solutions that describe a 3-brane world embedded in a D=5 dimensional bulk space-time are given.
Degenerate Spin Structures And The Lévy-Leblond Equation, Teki̇n Dereli̇, Şahi̇n Koçak, Murat Li̇moncu
Degenerate Spin Structures And The Lévy-Leblond Equation, Teki̇n Dereli̇, Şahi̇n Koçak, Murat Li̇moncu
Turkish Journal of Physics
Newton-Cartan manifolds and the Galilei group are defined by the use of co-rank one degenerate metric tensor. Newton-Cartan connection is lifted to the degenerate spinor bundle over a Newton-Cartan 4-manifold by the aid of degenerate spin group. Levy-Leblond equation is constructed with the lifted connection.
Explicit Realization Of Pseudo-Hermitian And Quasi-Hermitian Quantum Mechanics For Two-Level Systems, Ali̇ Mostafazadeh, Seher Özçeli̇k
Explicit Realization Of Pseudo-Hermitian And Quasi-Hermitian Quantum Mechanics For Two-Level Systems, Ali̇ Mostafazadeh, Seher Özçeli̇k
Turkish Journal of Physics
We give an explicit characterization of the most general quasi-Hermitian operator H, the associated metric operators \eta_+, and \eta_+-pseudo-Hermitian operators acting in C^2. The latter represent the physical observables of a model whose Hamiltonian and Hilbert space are respectively H and \C^2 endowed with the inner product defined by \eta_+. Our calculations allows for a direct demonstration of the fact that the choice of an irreducible family of observables fixes the metric operator up to a multiplicative factor.
Infinite-Hamiltonian Structures Of The Riemann Equation, Refi̇k Turhan
Infinite-Hamiltonian Structures Of The Riemann Equation, Refi̇k Turhan
Turkish Journal of Physics
We give two distinct infinite-Hamiltonian representations for the Riemann equation. One with first order Hamiltonian operators and another with third order-first order Hamiltonian operators. Both representations contain an arbitrary function of the dynamical variable. We prove that all the Hamiltonian operators of the Riemann equation are mutually compatible.
Dimensional Crossover In Semiconductor Structures: From 3d Electron Transport To Ballistic Electrons In 1d, Karl-Fredrick Berggren
Dimensional Crossover In Semiconductor Structures: From 3d Electron Transport To Ballistic Electrons In 1d, Karl-Fredrick Berggren
Turkish Journal of Physics
Modern semiconductor technologies have made possible special devices in which a gradual dimensional crossover may be induced by means of applied electric fields. Two specific examples are described. The first one is a special GaAs field effect transistor in which the thickness of the active electron gas layer may be varied by external voltages. With decreasing layer thickness transverse states become quantized and by depopulating the corresponding subbands a tunable dimensional crossover from 3D to 2D is achieved. The second example describes how a 2D to 1D crossover may be obtained in high-mobility split-gate GaAs/AlGaAs heterostructures. Effects of interactions in …
Applications Of Genetic Algorithm To Quantum Mechanical Systems, Mehmet Şahi̇n, Ülfet Atav, Mehmet Tomak
Applications Of Genetic Algorithm To Quantum Mechanical Systems, Mehmet Şahi̇n, Ülfet Atav, Mehmet Tomak
Turkish Journal of Physics
Genetic algorithm (GA) inspired by the biological world is a general search and optimization method. It was first proposed by Holland in 1975. GA has been applied to many scientific areas especially in engineering optimization problems. It is also used in solving of quantum mechanical problems. In this study, we have applied this method to different realistic quantum mechanical problems of both self-consistent and non-self-consistent type. The results obtained are compared with the results of other methods and it is seen that the GA can be a very powerful alternative to some other traditional techniques such as variational method.
Tkachenko Modes Of The Square Vortex Lattice In A Two-Component Bose-Einstein Condensate, M. Keçeli̇, M. Ö. Oktel
Tkachenko Modes Of The Square Vortex Lattice In A Two-Component Bose-Einstein Condensate, M. Keçeli̇, M. Ö. Oktel
Turkish Journal of Physics
We study Tkachenko modes of the square vortex lattice of a two-component Bose-Einstein condensate (BEC) in the mean-field quantum Hall regime, considering the coupling of these modes with density excitations. We derive the hydrodynamic equations and obtain the dispersion relations of the excitation modes. We find that there are two types of excitations, gapped inertial modes and gapless Tkachenko modes. These modes have two branches which we call acoustic and optical modes in analogy with phonons. The former has quadratic while the latter has linear wave-number dependence in both inertial and Tkachenko modes. Acoustic Tkachenko mode is found to be …
Pseudopotential-Based Full Zone K . P Technique For Indirect Bandgap Semiconductors: Si, Ge, Diamond And Sic, Ceyhun Bulutay
Pseudopotential-Based Full Zone K . P Technique For Indirect Bandgap Semiconductors: Si, Ge, Diamond And Sic, Ceyhun Bulutay
Turkish Journal of Physics
The k . p is a versatile technique that describes the semiconductor band structure in the vicinity of the bandgap. The technique can be extended to full Brillouin zone by including more coupled bands into consideration. For completeness, a detailed formulation is provided where the associated k . p parameters are extracted from the local empirical pseudopotential method in the form of band edge energies and generalized momentum matrix elements. We demonstrate the systematic improvement of the technique with the proper choice of the band edge states for the group-IV indirect bandgap semiconductors: Si, Ge, diamond and SiC of the …
A Detailed Ensemble Monte Carlo Study Of The Effect Of Quantum Well Width On Quantum Well Infrared Photodetector Characteristics, Sema Memi̇ş, Oray Orkun Cellek, Umut Bostanci, Mehmet Tomak, Cengi̇z Beşi̇kçi̇
A Detailed Ensemble Monte Carlo Study Of The Effect Of Quantum Well Width On Quantum Well Infrared Photodetector Characteristics, Sema Memi̇ş, Oray Orkun Cellek, Umut Bostanci, Mehmet Tomak, Cengi̇z Beşi̇kçi̇
Turkish Journal of Physics
We present a simulation based investigation of the dependence of the device characteristics on the quantum well width in AlGaAs/GaAs quantum well infrared photodetectors (QWIPs) through the ensemble Monte Carlo technique. The simulations on two different standard Al_{0.3}Ga_{0.7}As/GaAs QWIPs with quantum well widths of 36 and 44 Å have shown that the gain in the former is considerably higher, which is due to much longer lifetime of the photoexcited electrons as a result of lower capture probability in the device. We discuss this observation by the investigation of the electron scattering rates in these structures through realistically evaluated scattering mechanisms …
Helicity Dependence Of The \Vec\Gamma\Vec N \To \Pi N Reaction Channels In The \Delta-Resonance Region, Eed M. Darwish, Mohamed A. El-Zohry
Helicity Dependence Of The \Vec\Gamma\Vec N \To \Pi N Reaction Channels In The \Delta-Resonance Region, Eed M. Darwish, Mohamed A. El-Zohry
Turkish Journal of Physics
Based on a prior effective Lagrangian model on single pion photoproduction from the nucleon, successfully tested in total and differential cross sections, the helicity dependence from the interaction of circularly polarized photons and a longitudinally polarized nucleon target is studied in the energy range from \pi-threshold through the \Delta(1232)-resonance region. The doubly polarized total and differential cross section differences for parallel \sigma^{3/2} and antiparallel \sigma^{1/2} helicity states are predicted and compared with recent experimental data. We show that the results are sensitive to interferences among different contributions to the process and, thus, represent a complementary test of the theoretical model. …
Influence Of Thickness On Optical Properties Of A: As_2se_3 Thin Films, Dinesh C. Sati, Rajendra Kumar, Ram Mohan Mehra
Influence Of Thickness On Optical Properties Of A: As_2se_3 Thin Films, Dinesh C. Sati, Rajendra Kumar, Ram Mohan Mehra
Turkish Journal of Physics
This paper reports optical properties of amorphous chalcogenide thin films of As_2Se_3 of different thicknesses 2000-6800 Å. The transmittance and reflectance of thin films were measured in the wavelength range 500-1000 nm. It was found that the optical band gap increases with film thickness. Variation of refractive index n and extinction coefficient k with thickness have been studied to analyze optical efficiency of the As_2Se_3 thin films. The dielectric behavior of the films has also been studied and high frequency dielectric constants \varepsilon_{\infty} has been estimated as a function of thickness of films.
The Symmetric Teleparallel Gravity, Muzaffer Adak
The Symmetric Teleparallel Gravity, Muzaffer Adak
Turkish Journal of Physics
We study symmetric teleparallel (STP) gravity model, in which only spacetime non-metricity is nonzero. First we obtain STP equivalent Einstein-Hilbert Lagrangian and give an approach for a generic solution in terms of only metric tensor. Then we obtain a spherically symmetric static solution to the Einstein's equation in STP space-time and discuss the singularities. Finally, we study a model given by a Lagrangian 4-form quadratic in non-metricity. Thus, we seek Schwarzschild-type solutions because of its observational success and obtain some sets of solutions. Finally, we discuss physical relevance of the solutions.
Non-Commutative And Non-Anticommutative Supersymmetric U(1) Gauge Theories, Kayhan Ülker
Non-Commutative And Non-Anticommutative Supersymmetric U(1) Gauge Theories, Kayhan Ülker
Turkish Journal of Physics
We introduce a parent action for component fields of N=1 supersymmetric U(1) gauge theory in four dimensions which generates both the original and the (s-) dual supersymmetric actions. By using the noncommutative and nonanticommutative deformations of this theory we propose the corresponding parent actions as generalizations of the ordinary case. We then show that duality symmetry under the interchange of fields with duals accompanied by the replacement of the noncommutativity and nonanticommutativity parameters in a suitable way.
Quantum Information Entropies For The Morse Potential, Ekrem Aydiner, Cenk Orta, Ramazan Sever
Quantum Information Entropies For The Morse Potential, Ekrem Aydiner, Cenk Orta, Ramazan Sever
Turkish Journal of Physics
Quantum information entropies for the one dimensional Morse potential are discussed in position and momentum space. These entropies for different strengths of the potential well are numerically obtained. Interesting features of the entropy densities are also graphically demonstrated and it is shown that the position and momentum space information entropies satisfy the bound which is obtained by Beckner, Bialynicki-Birula, and Mycielski.
Coset Algebras Of The Maxwell-Einstein Supergravities, Nejat Tevfi̇k Yilmaz
Coset Algebras Of The Maxwell-Einstein Supergravities, Nejat Tevfi̇k Yilmaz
Turkish Journal of Physics
The general structure of the scalar cosets of the Maxwell-Einstein supergravities is given. Following an introduction of the non-linear coset formalism of the supergravity theories a comparison of the coset algebras of the Maxwell-Einstein supergravities in various dimensions is discussed.
Hamilton-Jacobi Formulation Of Siegel Superparticle, N. I. Farahat, Hanaa A. Elegla
Hamilton-Jacobi Formulation Of Siegel Superparticle, N. I. Farahat, Hanaa A. Elegla
Turkish Journal of Physics
The Hamilton-Jacobi formalism of constrained systems is used to study Siegel superparticles moving in R^{4 mid 4} flat superspace. The equations of motion for a singular system are obtained as total differential equations in many variables. These equations of motion are in exact agreement with those obtained by Dirac's method.