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The Effect Of Temperature Dependent Frequency Factor On The Evaluated Trapping Parameters Of Tsl Glow Curves, A. N. Yazici, Z. Öztürk Jan 1998

The Effect Of Temperature Dependent Frequency Factor On The Evaluated Trapping Parameters Of Tsl Glow Curves, A. N. Yazici, Z. Öztürk

Turkish Journal of Physics

The effect of temperature dependency on frequency factor and its relationship to trapping parameters is discussed by using the peak shape method. The coefficients appearing in the peak shape formula for the calculation of the activation energy have been determined and tabulated for the symmetry factor $\mu_g(X)$ for $x=0.50$ and 0.75 of the peak intensity. It is found that significant errors occur in the value of the trapping parameters if the temperature dependecy of the frequency factor is not consider.


A Time-Dependent Quantum Study Of Li+Hf(\Nu=1) -> Lif(\Nu')+H, Fahrettin Gögtaş, Gabriel G. Balint-Kurti Jan 1998

A Time-Dependent Quantum Study Of Li+Hf(\Nu=1) -> Lif(\Nu')+H, Fahrettin Gögtaş, Gabriel G. Balint-Kurti

Turkish Journal of Physics

Time-dependent quantum wave packet calculations are performed for a model based (two-dimensional) $Li+HF(\nu=1)\ra LiF(\nu^{\prime})+H$ reaction. The reaction probabilities for a broad range of collison energies are calculated by a single solution of the time-dependent Schr\\"{o}dinger equation. The calculated reaction probabilities show many sharp features as a function of energy which are ascribed to scattering resonances.


Rotation In Stars, Halil Kirbiyik Jan 1998

Rotation In Stars, Halil Kirbiyik

Turkish Journal of Physics

In this study the subject of rotation in stars and its effects have been considered. First the historical development of the subject is reviewed. After discussing the observational aspects of rotation, the effect of rotation on evolution has been investigated. The velocity of rotational meridional circulation currents and related time scales were estimated. Mixing induced by circulation currents and the turbulence which may appear as a result of such a mixing have been studied. Order of magnitude calculations have shown that rotational mixing may occur in early type stars and thus contributes to the diffusion of chemical elements. Thus, it …


The Solutions Of The Classical Relativistic Two-Body Equation, Coşkun Önem Jan 1998

The Solutions Of The Classical Relativistic Two-Body Equation, Coşkun Önem

Turkish Journal of Physics

With the relativistic Kepler problem, a two-body system is studied for positronium, the hydrogen atom and $m_2 >> m_1$ cases.


Dimensionality And Energy Levels Of Quantum Mechanical Systems, Harry A. Mavromatis Jan 1998

Dimensionality And Energy Levels Of Quantum Mechanical Systems, Harry A. Mavromatis

Turkish Journal of Physics

The $N$-dimensional Schrödinger equation involving a general, central potential $V_N(r)$, is decomposed into a 3-dimensional component plus a term that may be treated as a dimension-dependent perturbation. This allows discussion of the general $N$-dimensional system from a 3-dimensional perspective.


Symmetry Of C_{60} And A Force Constant Model For Vibrational Modes, Ramazan Koç, Hayriye Tütüncüler Jan 1998

Symmetry Of C_{60} And A Force Constant Model For Vibrational Modes, Ramazan Koç, Hayriye Tütüncüler

Turkish Journal of Physics

A force-constant model for the vibrational modes in $C_{60}$ is presented. The Keating type potential is adopted for calculating the dynamical matrix. Using symmetries of the molecule, the dynamical matrix which yields the vibrational modes is block-diagonalized. We summarize the role of group theory in specifying the vibrational modes. The results are in excellent agreement with experiments. The effect of bond-stretching force constants on the vibrational modes will be presented.


Structural Defects And Electrical Properties Of Extruded Samples Of Bi_{85}Sb_{15} Solid Solutions, Farkhad Samedov, Mail Tagiev Jan 1998

Structural Defects And Electrical Properties Of Extruded Samples Of Bi_{85}Sb_{15} Solid Solutions, Farkhad Samedov, Mail Tagiev

Turkish Journal of Physics

The effect of 5 hours annealing in vacuum $\sim 10^{-3} Pa$ at $503 K$ on the electroconductivity $(\sigma)$, the coefficient of thermoelectric power $(\alpha)$ and the Hall coefficient $(R_x)$ for extruded samples of $Bi_{85}Sb_{15}$ has been investigated in the temperature range from $\sim 77 K$ up to $\sim 300 K$. The samples were taken with a different concentration of $Pb$ (lead) up to $\sim 0.1 a.w \%$. The anisotropy of electrical properties of these samples was also studied in the temperature range between $77 K$ and $300 K$ and in the presence of magnetic field up to $\sim 74 \times …


Theoretical Analysis Of The Crystallography For Do_3 --> M18r Martensitic Transformation, Seyfettin Çakmak, Ekrem Artunç Jan 1998

Theoretical Analysis Of The Crystallography For Do_3 --> M18r Martensitic Transformation, Seyfettin Çakmak, Ekrem Artunç

Turkish Journal of Physics

A mathematical approach of the phenomenological theory has been applied to the martensitic transformation of DO$_3 \rightarrow$ M18R close-packed structure. The crystallography of DO$_3 \rightarrow$ M18R martensitic transformation in Fe-25.8 wt\%Mn-7.4wt\%Al-0.11wt\%C alloy was studied using single crystals. Martensitic crystallographic parameters such as habit plane, magnitude of lattice invariant shear, shape deformation direction and orientation relationships are calculated with new mathematical approach. Phenomenological theoretical calculations were compared with predictions of the phenomenological crystallographic CRAB theory and with experimental observations.


Effect Of Neutron Irradiation On Carriers Removel Rates In N-Si, M.S. Yunusov, M. Karimov, B.L. Oksengendler, M.A. Zhalelov Jan 1998

Effect Of Neutron Irradiation On Carriers Removel Rates In N-Si, M.S. Yunusov, M. Karimov, B.L. Oksengendler, M.A. Zhalelov

Turkish Journal of Physics

Carrier removal rate in $n-Si \langle P, Rh \rangle$ with different doping rhodium concentrations were investigated under fast neutrons irradiation. It is shown that the rate of carrier removal increases with phosphorus atom concentration but decreases with rhodium atom concentration. Theoretical analysis on the base of kinetic equations has shown that standard scheme of quasichemical reactions taking into account the interaction between rhodium atoms, vacancies and self interstitial atoms could not explain the results of experiment. Therefore a new model based on the use of radiation to increase the barrier between regions of fluctuating impurity concentration has been proposed.


An Analysis Of The Variation In Calculated Confined-State Energies Using Different Envelope-Function Models, Beşire Gönül Jan 1998

An Analysis Of The Variation In Calculated Confined-State Energies Using Different Envelope-Function Models, Beşire Gönül

Turkish Journal of Physics

We investigate different formulations of the envelope-function method and show that the accuracy of the calculated zone-centre confinement energies can be calculated by means of bulk band structure. We show how coupling to the conduction and spin-split-off bands can decrease the light-hole zone-centre confinement energies and lead to significant differences in the calculated subband dispersion.


Q1d-Polarons In Rigid Boundary Cylindrical Wires: "Mixed-Coupling Approximation", R. T. Senger And A. Erçelebi̇ Jan 1998

Q1d-Polarons In Rigid Boundary Cylindrical Wires: "Mixed-Coupling Approximation", R. T. Senger And A. Erçelebi̇

Turkish Journal of Physics

We consider the interaction of a confined electron with bulk polar-optical phonons in a cylindrical quantum well wire with infinite boundary potential. Expressions for the polaron self energy and mass are derived within a composite variational scheme consisting of a strong-coupling characterization imposed in the lateral directions and a weak-coupling LLP-counterpart structured along the length of the wire. The formulation is seen to be rather commendable and yields a sensible description of the Q1D-polaron in thin wires of weak or intermediate electron-phonon coupling strengths.


Singlet Axial Current Form Factor In The Chiral Solitonic Bag Model With Massive Quarks, N. Karagöz Jan 1998

Singlet Axial Current Form Factor In The Chiral Solitonic Bag Model With Massive Quarks, N. Karagöz

Turkish Journal of Physics

Singlet axial current form factor $g_A^0$ is calculated as a function of bag radius in the two flavor chiral solitonic bag model with unequal quark masses. The value of $g_A^0$ near 1 fm is sufficiently small.


Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov Jan 1998

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.


Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya Jan 1998

Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya

Turkish Journal of Physics

In this work, we develop a model for radiant heat transfer calculations inside spherical and cylindrical spaces. The analysis of the possibility of mirror cone subreflector applications for uniform flux density attainment is carried out. A procedure optimizing equiilluminate space forming a search for an indicatrix's composition is developed.


Anomalous Electrical Characteristics Of Ion Implanted P^+-N Juntions, N. Siddiqui Jan 1998

Anomalous Electrical Characteristics Of Ion Implanted P^+-N Juntions, N. Siddiqui

Turkish Journal of Physics

Electrical characteristics of three $P^+ - n$ diodes fabricated on high resistivity silicon by ion implantation technique are studied by making capacitance-voltage (C-V), reverse current-voltage (I-V) and dielectric spectroscopy of semiconductor (DSS) measurements. The C-V characteristics show abrupt fall in capacitance, while I-V characteristics show abrupt rise in current at the same voltages as in the C-V characteristics. These abrupt discontinuities are ascribed to the formation of defect clusters in the lightly doped base regions where charge transfer might be taking place by thermally assisted tunneling. Low activation energies obtained in the DSS measurements also point toward the same mechanism.


Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar Jan 1998

Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar

Turkish Journal of Physics

Polymer dispersed liquid crystal (PDLC) films are potentially useful in electro-optic devices since they can be used for vision products. In this work the PDLC thin films were prepared by a photopolymerization induced phase separation method and electro-optic properties of the films were investigated.


The Effect Of Halogen Impurities On Electrocunductivity Of Chalcogenide Glass Semicunductor Se-As System, A.I. Isaogli, S.M. Ibrahimgizi, A.R. Kamilogli Jan 1998

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.


Fibonaccization And Multiparameter Q-Oscillator, M. Arik, T. Rador, G. Ünel Jan 1998

Fibonaccization And Multiparameter Q-Oscillator, M. Arik, T. Rador, G. Ünel

Turkish Journal of Physics

Starting from Coon-Baker-Yu (CBY) q-oscillator, a two parameter, multidimensional q-oscillator is formulated. It is shown that this procedure, called Fibonaccization, can be extended to any number of parameters. The relation between CBY states and Fibonacci CBY states are also investigated.


Comparison Of Metallicities Adopted For The Synthetic Ubv Photometry With Those Evaluated By Means Of Rgu Photometry, S. Karaali̇, S. Güngör, Y. Karataş Jan 1998

Comparison Of Metallicities Adopted For The Synthetic Ubv Photometry With Those Evaluated By Means Of Rgu Photometry, S. Karaali̇, S. Güngör, Y. Karataş

Turkish Journal of Physics

Comparison of metallicities adopted for synthetic UBV photometry with those evaluated by means of RGU photometry for 92 stars is presented. The agreement is only for zero metallicity. The discrepancy increases to low metallicities which cover Intermediate Population II and Population II main-sequence stars. U-G and G-R colour indices are transformed from UBV synthetic data and do not include any observational error. Therefore, the disagreement may originate from a systematic error in the metallicity calibration of relatively metal-poor stars in RGU photometry. Keywords: photometry - stars : abundances - metal-poor.


Study Of The Total Reaction Cross Section Of 17.0 Mev=N 132 Xe + 238 U Heavy Ion Interactions, J.J. Baluch, E.U. Khan, M.S. Zafar, I.E. Qureshi Jan 1998

Study Of The Total Reaction Cross Section Of 17.0 Mev=N 132 Xe + 238 U Heavy Ion Interactions, J.J. Baluch, E.U. Khan, M.S. Zafar, I.E. Qureshi

Turkish Journal of Physics

We have studied heavy ion nuclear interactions of 17.0 $MeV/N$ $^{132}Xe+^{238}U$ using muscovite mica as Solid State Nuclear Track Detector (SSNTD). Experimental reaction cross section has been determined by two independent methods. Theoretical reaction cross section has been calculated by a classical formula taking into account the energy dependence of the nuclear radius parameter. The cross section determined in the present work has been compared with those at two other energies for the same reaction.


Magnetic Diffuse Scattering In The Frustrated Square Lattice, Ali Bayri, Funda Ersoy Atalay, Hüseyin Gencer Jan 1998

Magnetic Diffuse Scattering In The Frustrated Square Lattice, Ali Bayri, Funda Ersoy Atalay, Hüseyin Gencer

Turkish Journal of Physics

Some of the first transition metal alloys show first order antiferromagnetic phase transition as a function of alloy concentration [1-5]. The antiferromagnetism of materials can be classified into three different class: type I, type II and type III. Although the neutron diffraction studies give information about the type of magnetism, they do not show the fluctuations of magnetic moment from the original direction. So in order to have some information about this fluctuations one must perform the magnetic diffuse scattering. Recently, we proposed that the square lattice may have a double-Q structure as well as single-Q [6]. We showed that …


Solution Of Optic Reconstructive Problem Considering Registered Signal Velocity, A.A. Aliverdiev, M.G. Karimov Jan 1998

Solution Of Optic Reconstructive Problem Considering Registered Signal Velocity, A.A. Aliverdiev, M.G. Karimov

Turkish Journal of Physics

A solution to the tomographic problem of dynamic reconstruction of a processes, the rate of which is comparable with the velocity of the registered signal is presented. The obtained data can be used both for theoretical and applied tomography.


The Eect Of Exposure Time To Clean Room Air On Characteristic Parameters Of Au /Epilayer N-Si Schottky Diodes, M. Sağlam, Ç. Nuhoğlu, E. Ayyildiz, A. Türüt, H.A. Çeti̇nkara Jan 1998

The Eect Of Exposure Time To Clean Room Air On Characteristic Parameters Of Au /Epilayer N-Si Schottky Diodes, M. Sağlam, Ç. Nuhoğlu, E. Ayyildiz, A. Türüt, H.A. Çeti̇nkara

Turkish Journal of Physics

A study has been made on determination and comparison of current-voltage (I-V) and capacitance-voltage (C-V) characteristics parameters of $Au/n-Si$ Schottky barrier diodes (SBDs) with and without thin native oxide layer fabricated on $n$-type $Si$ grown by LPE (Liquid-phase Epitaxy) technique. The native oxide layer with different thicknesses on chemically cleaned on $Si$ surface were obtained by exposing the surfaces to clean room air before evaporating metal. The native oxide thicknesses of samples D2, D3, D4 and D5 are in the form $D2 < D3 < D4 \leq D5$, depending on the exposing time. It has been seen that the values of barrier height $\Phi_b$ of samples D2(0.64 eV), D3(0.66 eV), D4(0.69 eV) and D5(0.69 eV) with the interfacial layer increased with increasing the exposure time and tended to that of the initial sample D1 (nonoxidezed sample, 0.74 eV), and thus also their I-V and C-V curves. The reverse current of sample D1 showed slight nonsaturating behavior. This ''soft'' behavior has been ascribed to the spatial inhomogeneity in the barrier heights at the MS interface. In particular, reverse bias curves of samples D2, D3, D4 and D5 have shown excellent saturation which may be attributed to the passivation of the semiconductor surface states by the native oxide layer which reduces the penetration of the wave functions of electron in the metal into the semiconductor. Especially, the I-V characteristics and experimental parameters of our devices are in agreement with recently reported results revealed by the pulsed surface photovoltage technique for the electronic properties of the HF-treated Si surface during initial oxidation in air.


Resonans Reflectionless Absorption Ofelectromagnetic Waves In Solutions, E. Salaev, E. Gasimov, S. Azizov, J. Qajar Jan 1998

Resonans Reflectionless Absorption Ofelectromagnetic Waves In Solutions, E. Salaev, E. Gasimov, S. Azizov, J. Qajar

Turkish Journal of Physics

No abstract provided.


\Tau->\Rho\Nu Decay And Leptonic Decay Constants Of Vector Mesons, Kh. Ablakulov, B.N. Kuranov, T.Z. Nasyrov Jan 1998

\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 Jan 1998

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 Jan 1998

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.


Quaternionic Roots Of E 8 Related Coxeter Graphs And Quasicrystals, Mehmet Koca, Nazife Özdeş Koca, Ramazan Koç Jan 1998

Quaternionic Roots Of E 8 Related Coxeter Graphs And Quasicrystals, Mehmet Koca, Nazife Özdeş Koca, Ramazan Koç

Turkish Journal of Physics

The lattice matching of two sets of quaternionic roots of $F_4$ leads to quaternionic roots of $E_8$ which has a decomposition $H_4 + \sigma H_4$ where the Coxeter graph $H_4$ is represented by the 120 quaternionic elements of the binary icosahedral group. The 30 pure imaginary quaternions constitute the roots of $H_3$ which has a natural extension to $H_3 + \sigma H_3$ describing the root system of the Lie algebra $D_6$. It is noted that there exist three lattices in 6-dimensions whose point group $W(D_6)$ admits the icosahedral symmetry $H_3$ as a subgroup, the roots of which describe the mid-points …


Eect Of Sintering Time On Sb Added Bipbsrcacuo Superconducting Ceramics, K. Kocabaş Jan 1998

Eect Of Sintering Time On Sb Added Bipbsrcacuo Superconducting Ceramics, K. Kocabaş

Turkish Journal of Physics

In this study, superconducting Sb doped BiPbSrCaCuO ceramics with a fixed nominal composition were prepared and sintered at 850^oC for different periods. The structural phases of the sintered ceramics were determined by means of the measurements of the resistivity-temperature behaviour and of the XRD analysis. Sb doping along with Pb doping in the BiSrCaCuO ceramics was observed to increase the volume fraction of the high $T_c$ phase, the onset temperature and the critical temperature $T_c$. The critical temperature for the 100 hour sintered sample was 4K higher than that of the 60 hour sintered sample.


Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇ Jan 1998

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 $CdTe$ …