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Articles 1 - 30 of 65
Full-Text Articles in Physics
Calculation Of The Potential And Electric Flux Lines For Parallel Plate Capacitors With Symmetrically Placed Equal Lengths By Using The Method Of Conformal Mapping, Erhan Albayrak
Turkish Journal of Physics
The classical problem of the parallel-plate capacitors has been investigated by a number of authors, including Love [1], Langton [2] and Lin [3]. In this paper, the exact equipotentials and electric flux lines of symmetrically placed two thin conducting plates are obtained using the Schwarz- Cristoffel transformation and the method of conformal mapping. The coordinates x , y in the z-plane corresponding to the constant electric flux lines and equipotential lines are obtained after very detailed and cumbersome calculations. The complete field distribution is given by constructing the family of lines of electric flux and equipotential.
Optical Transmission Measurements On Glow-Discharge Amorphous Silicon Nitride Films, İlker Ay, Hüseyi̇n Tolunay
Optical Transmission Measurements On Glow-Discharge Amorphous Silicon Nitride Films, İlker Ay, Hüseyi̇n Tolunay
Turkish Journal of Physics
Hydrogenated amorphous silicon nitride films have been prepared by the glow-discharge decomposition of ammonia/silane gas mixture. From optical transmission measurements in the wavelength range from 400 nm to 1100 nm refractive indices absorption coefficients and optical Tauc gaps of the films have been obtained. A systematic investigation of optical parameters has been carried out as a function of the nitrogen content of samples.
Study Of Slip Systems In Epidote Single Crystal, Salah-Ud Din, Munnawar Ahmad, Shahzad Chishti
Study Of Slip Systems In Epidote Single Crystal, Salah-Ud Din, Munnawar Ahmad, Shahzad Chishti
Turkish Journal of Physics
Measurements of microhardness anisotropy by Knoop diamond indentations on the prismatic (100) planes of epidote crystals, point group 2/m and space group P21/m, show that microhardness is determined by crystallographic slip on the (100) systems. Microhardness anisotropy is explained in terms of the effective resolved shear stress distribution in these slip systems.
Computation Of Overlap, Kinetic And Nuclear Attraction Integrals By A Novel Method, Gökhan Budak, Abdulhali̇k Karabulut, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n
Computation Of Overlap, Kinetic And Nuclear Attraction Integrals By A Novel Method, Gökhan Budak, Abdulhali̇k Karabulut, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n
Turkish Journal of Physics
A new way of computing overlap, kinetic and nuclear attraction integrals over Slater functions by means of optimized Gaussian expansion is proposed. This article is concerned with the construction of the general algorithm for evaluating the three integrals. These integral formulae presented in the form of a series whose terms are the analytical function of inter-atomic distances. In the present method, unlike many other popular methods, the numerical integration procedure is unnecessary since it does not contain the incomplete gamma function. The present scheme has been programmed in standard Fortran-77 and tested for various orbitals. The result of the calculation …
Some String Cosmological Models In Cylindrically Symmetric Inhomogeneous Universe, Hüsnü Baysal, İlhami̇ Yavuz, İsmai̇l Tarhan, Uğur Camci, İshan Yilmaz
Some String Cosmological Models In Cylindrically Symmetric Inhomogeneous Universe, Hüsnü Baysal, İlhami̇ Yavuz, İsmai̇l Tarhan, Uğur Camci, İshan Yilmaz
Turkish Journal of Physics
The aim of this paper is to investigate the behavior of a string in the cylindrically symmetric inhomogeneous cosmological model. It has been assumed that expansion \theta in the model is proportional to \sigma^1_1 of the eigenvalue of the shear tensor \sigma^{\mu}_{\nu}. Also, various physical and geometrical properties of the model have been discussed.
Lattice Dynamical Calculations For The Co-Fe Alloys, Kemal Çolakoğlu, Yasemi̇n Özteki̇n Çi̇ftçi̇
Lattice Dynamical Calculations For The Co-Fe Alloys, Kemal Çolakoğlu, Yasemi̇n Özteki̇n Çi̇ftçi̇
Turkish Journal of Physics
Lattice dynamical calculations are performed on Co_{0.92}-Fe_{0.08} alloy with fcc structure. The de Launay Angular force (DAF) model is used to represent the ion-ion intreactions, and the long-range ion-electron interactions are accounted for along the lines of the Sharma-Joshi scheme. The frequency distribution and the lattice specific heat are also computed for the studied alloys. The present theoretical results are in reasonable agreement with the available experimental data.
Second Order Elastic Constants And Some Thermoelastic Properties Of Alkali Halides Using Woodcock Potential, Harun Reşi̇t Yazar, Sedat Ağan, Kemal Çolakoğlu
Second Order Elastic Constants And Some Thermoelastic Properties Of Alkali Halides Using Woodcock Potential, Harun Reşi̇t Yazar, Sedat Ağan, Kemal Çolakoğlu
Turkish Journal of Physics
Second Order Elastic Constants (S.O.E.C) of NaCl-type crystals have been calculated using the Woodcock potential. Short-range repulsive interactions have been included up to second-nearest neighbors. This potential form represents the composite form of the inverse power dependence and exponential dependence of the repulsive energy on interionic distance. Some thermoelastic and thermodynamic properties such as Anderson-Grüneisen parameters \delta _{T}, and \delta _{S}, Volume thermal expansion coefficient \beta and Grüneisen gama \gamma _{G} have been calculated in terms of calculated values of S.O.E.C and Third Order Elastic Constant ( T.O.E.C).
Computational Study For The Structural Change Of The System Cdte_{1-X} S_X Thin Film, Emad Khdayer Al-Shakarchi
Computational Study For The Structural Change Of The System Cdte_{1-X} S_X Thin Film, Emad Khdayer Al-Shakarchi
Turkish Journal of Physics
Polycrystalline thin film of the graded system CdTe_{1-x}S_{x} for x=0,0.1,\ldots,1 are prepared by using thermal evaporation technique deposited on the glass substrate with an average thickness 3000 Å for each individual value of x . XRD technique is used with the aid of a computational program to study the phase change from cubic zinc blend structure to hexagonal wurtzite with an inversion point related to the x-value. It is found that x=0.1 gives us an inversion point in the structural change from cubic to hexagonal phase.
The Lattice Dynamics And The Elastic Behaviour Of Fcc And Bcc Ba, Yasemi̇n Özteki̇n Çi̇ftçi̇, Kemal Çolakoğlu
The Lattice Dynamics And The Elastic Behaviour Of Fcc And Bcc Ba, Yasemi̇n Özteki̇n Çi̇ftçi̇, Kemal Çolakoğlu
Turkish Journal of Physics
The two-body pairwise E.G.E.P. (Extended Generalized Exponantial Potential) type Morse potential and volume dependent energy are assumed to represent the total energy of the Ba crystal. The parametrized potential is used to calculate the second- and third-order elastic constants C_{ij} and C_{ijk}, pressure derivatives of bulk moduli and Grüneisen parameter \gamma . The phonon frequencies are also computed and plotted. The obtained results are compared with available experimental data and, in general, the agreement is good.
Iba-1 Calculations Of E2/M1 Mixing Ratios And Quadrupole Moments In ^{154}Gd, Mehmet Baylan
Iba-1 Calculations Of E2/M1 Mixing Ratios And Quadrupole Moments In ^{154}Gd, Mehmet Baylan
Turkish Journal of Physics
In this study the Interacting Boson Approximation is applied in its basic form (IBA-1) to the calculation of gamma-ray E2/M1 multipole mixing ratios and quadrupole moments [Q( 2^{+} )] of electromagnetic transitions in ^{154}Gd. The numerical results obtained for ^{154}Gd are in reasanably good agreement with previous experimental and theoretical values.
Built-In Potential Measurements In A-Si:H P-I-N Solar Cells, Ruhi̇ Kaplan, Bengü Kaplan
Built-In Potential Measurements In A-Si:H P-I-N Solar Cells, Ruhi̇ Kaplan, Bengü Kaplan
Turkish Journal of Physics
We have measured the open-circuit voltage V_{oc} and the short-circuit current density J_{sc} of amorphous silicon (a-Si:H) p-i-n solar cells deposited by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at different monochromatic illuminations, and temperatures. From the measurements, the built-in potential V_{bi} was determined by using two different methods: activation energy and differential temperature. The results from both methods were analyzed and compared as a function of excitation wavelength. It was observed that there is good agreement between the two methods. We found that V_{bi} increases until about 650 nm, and then decreases with increasing wavelength. This behaviour is explained and …
Space Charge Limited Current At High Fields In Al-Ge-Al Surface Barrier Devices, A. I. Mukolu
Space Charge Limited Current At High Fields In Al-Ge-Al Surface Barrier Devices, A. I. Mukolu
Turkish Journal of Physics
The current-voltage (I-V) characteristics of Aluminium-Germanium-Aluminium (Al-Ge-Al) surface barrier devices at different fields (
Coproduct Of Su_{Q} (2), Coherent States And Four Point Function With Logarithmic Regge Trajectories, M. Arik, Ayşe Peker-Dobie
Coproduct Of Su_{Q} (2), Coherent States And Four Point Function With Logarithmic Regge Trajectories, M. Arik, Ayşe Peker-Dobie
Turkish Journal of Physics
The representation of the operators belonging to a 2 \times 2 SU_q (2) matrix yield a Hilbert space H. The coproducts of these operators define a Hilbert space H^{(2)} isomorphic to H and canonically embedded in H \otimes H. The four-point function obtained by taking the scalar product of the ground state of H^{(2)} with the coherent states in H \otimes H is uniquely defined, is meromorphic and has Regge behaviour.
Null String In Curved Backgrounds, Sergey Nikolaevich Roshchupkin
Null String In Curved Backgrounds, Sergey Nikolaevich Roshchupkin
Turkish Journal of Physics
We consider null string in curved backgrounds. Some exact solutions of the classical equations of motion and of the constraints for the null string in a large class of cosmological backgrounds are found.
On The Evaluation Of Determinantal Wave Functions In Open-Shell Hartree-Fock Theory, I. I. Guseinov, Ramazan Demi̇r
On The Evaluation Of Determinantal Wave Functions In Open-Shell Hartree-Fock Theory, I. I. Guseinov, Ramazan Demi̇r
Turkish Journal of Physics
Slater method is modified for the evaluation of determinantal wave functions appearing in open-shell Hartree-Fock (HF) theory [1]. Using modified Slater method we have calculated, as an example, the orbital energies and the wave functions of terms obtained from the electronic configuration of a ground state of an N-atom system in the Hartree-Fock-Roothaan (HFR) approximation. The modified determinantal method introduced in this paper can be of considerable help and importance in the simplification and calculation of atomic and molecular electronic structure.
Excitation Plus Ionization In Electron-Atom Collisions To He^{+} (N=2): (E,2e), (E, E\Gamma ) And (E, 2e\Gamma ) Studies, Mevlut Dogan, Albert Crowe
Excitation Plus Ionization In Electron-Atom Collisions To He^{+} (N=2): (E,2e), (E, E\Gamma ) And (E, 2e\Gamma ) Studies, Mevlut Dogan, Albert Crowe
Turkish Journal of Physics
Simultaneous excitation-ionization of helium atoms by electron impact is observed by the coincidence detection of the outgoing particles. The relationship between (e,2e), (e,e\gamma ) and (e,2e\gamma ) experiments is discussed.
Covariant Two Fermion Equations With Anomalous Moments, Ahmet Turan Alan, Z. Zekeri̇ya Aydin, Nuretti̇n Karagöz, Ali̇ Ulvi̇ Yilmazer
Covariant Two Fermion Equations With Anomalous Moments, Ahmet Turan Alan, Z. Zekeri̇ya Aydin, Nuretti̇n Karagöz, Ali̇ Ulvi̇ Yilmazer
Turkish Journal of Physics
We derive covariant equations for two-fermion systems, taking into account the anomalous magnetic moments of the particles.
Double Transition Effect In Anderson Transition, Hüseyi̇n Aktaş
Double Transition Effect In Anderson Transition, Hüseyi̇n Aktaş
Turkish Journal of Physics
In this work we have studied the electronic mobility \mu within a completely disordered lattice system by using the strong interatomic hopping potential V(r) = ( - {\frac{{r}}{{a_{o}} }}) \exp( - r / a_{o} ) for site representation of the Hamiltonian. It is shown that a metallic system of a completely disordered lattice first goes insulating and then goes back to metallic again at higher atomic density \rho .
Autoionization Resonances In The Simultaneous Excitation-Ionization Of Helium, Mevlut Dogan, Albert Crowe
Autoionization Resonances In The Simultaneous Excitation-Ionization Of Helium, Mevlut Dogan, Albert Crowe
Turkish Journal of Physics
The effect of autoionizing states on excitation-ionization processes has been investigated experimentally by observation of the electron impact ionization process leading to He^{ + }(2p) with the excitation energy region in helium corresponding to doubly excitated states above the second ionization threshold. Also, the process arising from the decay of the doubly excited `parity unfavoured' (2p^{2})^{3}P state of helium, is studied.
The Langmuir Properties Of A Mixed Copolysiloxane Monolayer, Rifat Çapan, Tim H. Richardson, David Lacey
The Langmuir Properties Of A Mixed Copolysiloxane Monolayer, Rifat Çapan, Tim H. Richardson, David Lacey
Turkish Journal of Physics
A family of linear copolysiloxanes [1-3] substituted with side chains containing carboxylic head groups has been synthesised. The Langmuir properties of the mixed monolayer at the water-air interface has been studied using a single layer Langmuir trough. The area per molecule for the mixed monolayer is calculated theoretically and experimentally. This study has not only shown that there is an excellent agreement between theoretical and experimental values, but has also shown that this mixed monolayer at the water-air interface can be transferred as a monolayer onto a solid substrate.
Magnetization Measurements On Electrodeposited Cu_{1 - X}Co_{X} Alloy Films, Ömer F. Bakkaloğlu, İsmai̇l H. Karahan, Hasan Efeoğlu, Muhammet Yildirim, Uğur Çevi̇k, Yahya Kemal Yoğurtçu
Magnetization Measurements On Electrodeposited Cu_{1 - X}Co_{X} Alloy Films, Ömer F. Bakkaloğlu, İsmai̇l H. Karahan, Hasan Efeoğlu, Muhammet Yildirim, Uğur Çevi̇k, Yahya Kemal Yoğurtçu
Turkish Journal of Physics
The magnetic properties of Cu_{1 - x}Co_{x} alloy films prepared by electrodeposition technique were investigated by Alternating Gradient Force Magnetometer. The magnetization curves of Cu_{0.94}Co_{0.06}, Cu_{0.87}Co_{0.13} and Cu_{0.74}Co_{0.26} films were easily saturated while the other Cu_{1 - x}Co_{x} samples with x= 0.17, 0.19 and 0.21 had more inclined magnetization curves. The saturation magnetization value of Cu_{1 - x}Co_{x} film increased with increasing Co content in the film. The minimum values of the ratio of remanence to magnetization and the coercive field were determined in the Cu_{0.81}Co_{0.19} alloy film among the others. The ferromagnetic order in the Cu_{1 - x}Co_{x} films …
Production And Structure Of Rapidly Solidified Al-Si Alloys, Orhan Uzun, Tuncay Karaaslan, Mustafa Keski̇n
Production And Structure Of Rapidly Solidified Al-Si Alloys, Orhan Uzun, Tuncay Karaaslan, Mustafa Keski̇n
Turkish Journal of Physics
Al-Si alloys with compositions 8, 12, 16wt% Si were manufactured by chill casting and melt-spinning (MS) methods. The resulting ribbon samples have been characterized by optical and scanning electron microscopy (SEM) and X-ray diffractometry and compared with their ingot counterparts. Microstructural examinations revealed that microstructures of the melt-spun ribbons were quite fine compared to their ingot counterparts. Both XRD analyses and microstructural examinations indicated that the solubility of Si in \alpha -Al phase was nearly complete.
Lattice Changes In Shape Memory Cuznal Alloys On Aging At Room Temperature, Seyfetti̇n Çakmak, Ekrem Artunç, Nejdet Kayali, Osman Adigüzel
Lattice Changes In Shape Memory Cuznal Alloys On Aging At Room Temperature, Seyfetti̇n Çakmak, Ekrem Artunç, Nejdet Kayali, Osman Adigüzel
Turkish Journal of Physics
The aging behavior of CuZnAl martensites (Cu-21.62 wt.% Zn-5.68 wt.% Al and Cu-24.98 wt.% Zn-4.43 wt.% Al) at about 297 K was studied by analyzing diffraction line profiles obtained by X-ray diffractometry. For the alloys, the change of the lattice parameters and the tetragonality associated with the aging time at room temperature were investigated. The habit planes versus the aging time at room temperature were calculated using the De Vos-Aernoundt-Delaey model, based on the crystallographic theory of Wechsler-Lieberman-Read(WLR), and from the DO_{3}\rightarrow 18R martensite transformation theory.
Physical Properties Of Melt-Cast Annealed Bi_{1.6}Pb_{0.4}Sr_{2}Ca_{3}Cu_{4} O_{12} Compound, Ati̇lla Coşkun, Beki̇r Özçeli̇k, Keri̇m Kiymaç
Physical Properties Of Melt-Cast Annealed Bi_{1.6}Pb_{0.4}Sr_{2}Ca_{3}Cu_{4} O_{12} Compound, Ati̇lla Coşkun, Beki̇r Özçeli̇k, Keri̇m Kiymaç
Turkish Journal of Physics
A Bi_{1.6}Pb_{0.4}Sr_{2}Ca_{3}Cu_{4}O_{12} compound was produced by melt-casting method. The microstructure of the sample was studied by Scanning Electron Microscopy. Phase analysis was carried out by X-ray diffraction patterns and EDAX. The electrical resistance exhibites the existance of a superconducting phase with an onset temperature T_{c} at 110 K along with a minor phase with an onset T_{c} at 80 K. It has been found that the superconducting phase temperature T_{c} increases with increasing sintering temperature.
Magnetoresistance Measurements On Electrodeposited Co_X Cu_{1-X} Alloy Films, Ömer F. Bakkaloğlu, İsmai̇l H. Karahan
Magnetoresistance Measurements On Electrodeposited Co_X Cu_{1-X} Alloy Films, Ömer F. Bakkaloğlu, İsmai̇l H. Karahan
Turkish Journal of Physics
Co_x Cu_{1-x} alloy films were prepared by using electrodeposition technique. The variations of Co and Cu contents of the films were investigated as functions of bath pH and Co content. The compositions of the alloy films were determined using an atomic absorption spectrophotometer. The crystal structures of the alloy films were analyzed using a Cu (K \alpha )-X-ray diffractometer. The diffraction lines observed were only those of copper component in the alloy films. All three films showed negative magnetoresistance and a giant magnetoresistance effect on the order of 1% in Co_{0.26} Cu_{0.74} and 1.7% in Co_{0.19} Cu_{0.81} alloy films at …
Multiple Structures Of (110) Csl Twist Boundaries In Fcc Metals, A. Ghafoor, B. A. S. Faridi, S. A. Ahmad
Multiple Structures Of (110) Csl Twist Boundaries In Fcc Metals, A. Ghafoor, B. A. S. Faridi, S. A. Ahmad
Turkish Journal of Physics
The geometry of different possible structures of (110) fcc twist boundaries is explored. Computer simulation of all possible low energy structures have been carried out for \Sigma=3 and \Sigma=9 twist boundaries using many-body potentials representing copper, silver and gold. Low symmetry structures are found to have lower energies than the high symmetry CSL structures.
A Novel Technique For The Preparation Of Textured Yba_{2}Cu_{3}O_{7-\Delta} Superconductor, Naheed Kouser, Saadat Anwar Siddiqi, Asghari Maqsood
A Novel Technique For The Preparation Of Textured Yba_{2}Cu_{3}O_{7-\Delta} Superconductor, Naheed Kouser, Saadat Anwar Siddiqi, Asghari Maqsood
Turkish Journal of Physics
Textured samples having composition of YBa_{2}Cu_{3}O_{7-\delta} were prepared by using a novel technique of heating the samples in a thermal gradient which varies linearly between 930-950 ^oC over a distance of 5 cm. The samples were characterized by X-ray powder diffraction analysis, temperature dependent resistivity and magnetic susceptibility measurements, and scanning electron microscopy. XRD analysis shows that sample heated between 930-935 ^oC has tetragonal symmetry and all other three samples show orthorhombic symmetry. Samples heated in temperature gradient of 935-945 ^oC aligned along the c-axis. The orthorhombic samples exhibited zero resistance above 86K with short transition width and samples heated …
Multiparticle Equations For Scalar Particles, Valery Nikolaevich Kapshai, Alexander Ivanovich Fursin
Multiparticle Equations For Scalar Particles, Valery Nikolaevich Kapshai, Alexander Ivanovich Fursin
Turkish Journal of Physics
Multiparticle equations for scalar particles are derived in the framework of the Lagrangian formalism of field theory as a consequence of the Dyson-Schwinger equations for the generating functional of Green's functions. The general form of the n-particle equation is determined. The formula for the kernel of the equation is obtained. It makes possible to use the functional methods for the investigation of the equation. It is proven that the equation is correct in the lower orders for two-particle Green's functions.
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.