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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 …
Profiling Of Lithium And Potassium Into Silicon, Ali M. Mousa
Profiling Of Lithium And Potassium Into Silicon, Ali M. Mousa
Turkish Journal of Physics
The profiling of Lithium and Potassium into Silicon doped by electro deposition from molten salts (LiBr, KI) has been studied for various time periods and deposition currents. For the samples studied, changes in the deposition time and current have significant effects on the conductivity type and sheet resistance variation. This has been attributed to the high value of solid solubility of Lithium and Potassium in Silicon. Additionally, surface concentration variation with depth is affected significantly by variation in deposition time, particular for samples with a deposition time of 7 minutes. A junction was found 156 microns from the surface. For …
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 …
Inexpensive Near-Ir Photodetector, Omar A. Abdulrazaq, Evan T. Saleem
Inexpensive Near-Ir Photodetector, Omar A. Abdulrazaq, Evan T. Saleem
Turkish Journal of Physics
Fabrication and characterization of a CdS/Si heterojunction detector for 1.064 \mu m Nd:YAG laser detection has been carried out by pyrolytic spraying of CdS films onto single crystal n-type Si substrates. Response time has been determined in this study.
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.
Pendant ^{13}C Nmr Spectroscopy Applied To Ch_N Groups, Azmi̇ Gençten, İrfan Şaka, Sedat Gümüş
Pendant ^{13}C Nmr Spectroscopy Applied To Ch_N Groups, Azmi̇ Gençten, İrfan Şaka, Sedat Gümüş
Turkish Journal of Physics
Polarization enhancement nurtured during attached nucleus testing (PENDANT) NMR spectroscopy gives signals of quaternary carbon atoms in addition to signals indicative of CH, CH_2 and CH_3 groups. In this study, using product operator theory, analytical description of PENDANT NMR spectroscopy for CH_n (IS_n, I = 1/2, S = 1/2, n = 0, 1, 2, 3) spin systems are presented. Simulation and experimental results of PENDANT NMR spectroscopy are also presented. Theoretical results are found to be in exact agreement with the simulation results and in good agreement with the experimental ones.
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.
Relativistic Density Functional Theory Method: Applications To Autoionization States Of Atoms, Şaki̇r Erkoç
Relativistic Density Functional Theory Method: Applications To Autoionization States Of Atoms, Şaki̇r Erkoç
Turkish Journal of Physics
A brief introductory information about the accurate atomic calculations using Density Functional Theory has been reviewed. How relativistic effects can be considered in atomic calculations through the density functional theory has been discussed. Some sample calculation results for the autoionization states of the neutral and cationic atoms have been presented.
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 …
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.
First Principles Approach To Batio_3, Mustafa Uludoğan, Tahi̇r Çağin
First Principles Approach To Batio_3, Mustafa Uludoğan, Tahi̇r Çağin
Turkish Journal of Physics
We present state of art first-principles study on the static and dynamic properties of BaTiO_3, a typical ferroelectric material. Here, structure, equation of state, phase stability, and phase transformations of BaTiO_3 studied in Generalized Gradient Approximation. Furthermore, properties such as, Born effective charges, optical dielectric constant and phonon spectra are calculated from Density Functional Perturbation Theory.
A Molecular Dynamics Study Of The Static Structure, Thermodynamic And Transport Properties Of Liquid Iron Using The Modified Analytic Embedded Atom Method, Serap Şentürk Dalgiç, İbrahi̇m Koçoğlu
A Molecular Dynamics Study Of The Static Structure, Thermodynamic And Transport Properties Of Liquid Iron Using The Modified Analytic Embedded Atom Method, Serap Şentürk Dalgiç, İbrahi̇m Koçoğlu
Turkish Journal of Physics
Using the modified analytic embedded atom method (MAEAM), we have carried out molecular dynamics (MD) simulation to compute structure,thermodynamic and transport properties of liquid iron. The Foiles type effective pair potential based on the MAEAM potential functions proposed by Quyang and co-workers are shown to predict the pair distribution function well near its melting. The calculated thermodynamic properties such as, the internal energy, Helmholtz free energy and entropy are in a good agreement with experimental data. The results for the computed self-diffusion coefficients are in reasonable agreement with experiments and other works.
Self-Diffusion Coefficients In Liquid Ag Using The Embedded Atom Model Based Effective Pair Potentials, Seyfetti̇n Dalgiç, Mutlu Çolakoğullari
Self-Diffusion Coefficients In Liquid Ag Using The Embedded Atom Model Based Effective Pair Potentials, Seyfetti̇n Dalgiç, Mutlu Çolakoğullari
Turkish Journal of Physics
We present the dynamical properties of liquid Ag at different temperatures, using the Mishin and Doyoma-Kagure version of the Embedded Atom Model (EAM) potentials. They have been evaluated within the framework of the mode-coupling theory, using a self-consistent scheme that uses as input data only the static structure functions and the interatomic pair potentials of the liquid Ag. We have computed single-particle and collective time dependent properties of liquid Ag, and thereby calculated its self-diffusion constants. We have also discussed our results comparing with both experimental data and results of molecular dynamic simulation.
Molecular Dynamics Studies On Glass Formation Of Pd-Ni Alloys By Rapid Quenching, Sevgi̇ Özdemi̇r Kart, Mehmet Tomak, Mustafa Uludoğan, Tahi̇r Çağin
Molecular Dynamics Studies On Glass Formation Of Pd-Ni Alloys By Rapid Quenching, Sevgi̇ Özdemi̇r Kart, Mehmet Tomak, Mustafa Uludoğan, Tahi̇r Çağin
Turkish Journal of Physics
The rapid solidification of Pd-Ni alloys is studied with the constant-pressure and constant-temperature (TPN) and the constant-volume and constant-temperature (TVN) molecular dynamics technique to obtain an atomic description of glass formation in the alloy. Quantum Sutton-Chen potential for Pd-Ni binary system is applied in the simulations. We present some thermodynamic and structural results from simulations of such glasses over a range of compositions. The structural properties are analyzed by means of pair distribution function, volume, and enthalpy as a function of temperature and concentration at the cooling rates ranging from 5 K/ps to 0.05 K/ps to see whether the Pd-Ni …
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 …
Casimir Energies For Some Single Cavities, Haci Ahmedov, İsmai̇l Hakki Duru
Casimir Energies For Some Single Cavities, Haci Ahmedov, İsmai̇l Hakki Duru
Turkish Journal of Physics
Casimir energies are discussed for some cavities.
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.
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.
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.
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.