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Articles 10021 - 10050 of 10317
Full-Text Articles in Physical Sciences and Mathematics
Alpha Particle Fragments Produced From Multifragmentation Of ^{16}O+^{16}O, M.Y.H. Farag
Alpha Particle Fragments Produced From Multifragmentation Of ^{16}O+^{16}O, M.Y.H. Farag
Turkish Journal of Physics
Angular distribution for alpha particles produced from multifragmentation of ^{16}O + ^{16}O reactions are calculated using the statistical scission model. The alpha particles are sequentially emitted from long lived states of primary fragments populated in these reactions. Eight alpha particles are produced in these reactions. The calculations are carried out for different energies and for different nuclear temperatures. The variances of this multifragmentation process have been numerically calculated. The obtained results are in good agreement with previous calculations.
Thermodynamics And Structure Of Simple Liquid Metals Calculated Using An Analytic Pair Potential, Serap Dalgiç, Seyfettin Dalgiç, M. Tomak
Thermodynamics And Structure Of Simple Liquid Metals Calculated Using An Analytic Pair Potential, Serap Dalgiç, Seyfettin Dalgiç, M. Tomak
Turkish Journal of Physics
The analytic interatomic pair potential for simple metals is derived from first principles using second order pseudopotential theory by Pettifor and Ward . It is developed using the Heine-Abarenkov pseudopotential for simple metals and applied to the calculations of the structural and thermodynamic properties of liquid metals. The corresponding liquid metal structure is calculated using the random phase approximation and the hypernetted-chain formulation. The long-wavelength limit S(0) of the structure factor of liquid metals using the hard-sphere system as reference is also investigated. The calculated thermodynamic and structural properties using the real space formalism are in better agreement with experimental …
A Study On The Effect Of Ni Dopping On Bi-Pb-Sr-Ca-Cu-O System, M. Tepe, D. Abukay
A Study On The Effect Of Ni Dopping On Bi-Pb-Sr-Ca-Cu-O System, M. Tepe, D. Abukay
Turkish Journal of Physics
The effect of $Ni$ doping on superconductivity properties of the $Bi_{1.7}Pb_{0.3}Sr_2Ca_2(Cu_{1-x}Ni_x)_3O_y$ system has been investigated by means of $x$-ray diffraction, ac electrical resistance, ac magnetic susceptibility and critical current measurements. The volume fraction of the 2223 phase decreases with increasing $Ni$ concentration. The zero-resistance temperature and the critical current density are suppressed with $Ni$ substitution.
Characterization Of Sb Doped Y Bacuo Superconducting Ceramics, K. Kocabaş, N. Kazanci, M. Tepe
Characterization Of Sb Doped Y Bacuo Superconducting Ceramics, K. Kocabaş, N. Kazanci, M. Tepe
Turkish Journal of Physics
In this study the structural characteristics of $Sb_2O_3$ doped $YBa_2Cu_3O_{7-x}$ superconductive ceramics are investigated by electrical and XRD analyses. It is determined that, while in undoped specimens the value of $T_c$ is equal to 92 K, this value is negatively influenced by the addition of $Sb$. Structural phase results obtained from XRD analysis confirm the result obtained from the electrical measurements.
Microscopic Calculations Of The Nucleus-Nucleus Optical Potential, M. M. Osman
Microscopic Calculations Of The Nucleus-Nucleus Optical Potential, M. M. Osman
Turkish Journal of Physics
In present work, a density dependent nucleon-nucleon interactions based on the $G$-matrix elements of the Paris nucleon-nucleon potential have been used to calculate the real part of the nucleus-nucleus optical potential. We have compared our results with those deduced from experiment. We found that our results, obtained using a suitable approximation of the kinetic energy density, agree satisfactory with those extracted from experiment at the strong absorption radius. Moreover, the higher values of the compressibility, $K$, agree better with experiment than the lower values.
Deformation Methods For Investigation Of The Deep Level Parameters In Semiconductors, S. Z. Zainabidinov, A. Abduraimov, O. O. Mamatkarimov, I.G. Tursunov, R.Kh. Khamidov
Deformation Methods For Investigation Of The Deep Level Parameters In Semiconductors, S. Z. Zainabidinov, A. Abduraimov, O. O. Mamatkarimov, I.G. Tursunov, R.Kh. Khamidov
Turkish Journal of Physics
In this paper deformation methods are offered to investigate deep level parameters in semiconductors. It is based on strain parameters measurements of compensated and overcompensated semiconductors. The dynamic changes of current flow in compensated and overcompensated samples of $p$-type $Si: Ni$ and $n$-type $Si: Mn$ under uniform pulse hydrostatic compression (UHC) was investigated. It was observed that in $p$-type $Si: Ni$ samples ionization energy levels $Ni$ at UHC increases, on the contrary in samples $n$-type $Si: Mn$ it decreases. The ionization energy and baric coefficient of the shift of $Ni$ and $Mn$ levels were bounded.
Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov
Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov
Turkish Journal of Physics
Magnetization of MeFe$_2$Se$_4$ (Me = Ti; V; Cr; Fe; Co; Ni) compounds at low temperatures has been investigated. It is shown that these compounds are ferrimagnetics with low values of specific magnetization. It is established that along the crystal axis $c$ of a given compound, there have been carried out two types of exchange interactions; cation-cation and cation-anion-cation with different dependence of their quantity on interatomic distance.
Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya
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.
Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar
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.
Reorientation Of Magnetization In Thin Films, Bengü Kaplan
Reorientation Of Magnetization In Thin Films, Bengü Kaplan
Turkish Journal of Physics
The spin wave energy is determined by the competition between uniaxial and cubic anisotropy. We discuss the reorientation temperature $ T_{R} $ of magnetization in two-dimension and calculate its dependence on the exchange, $J$, and the uniaxial anisotropy, $G$, parameters within random phase approximation. We find that $ T_{R} $ varies as $ \sqrt{JG} $ in the planar regime.
Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov
Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov
Turkish Journal of Physics
The structure of ceramic materials containing molibdenum powder is considered within the framework of leakage theory. Determined are the density of the endless cluster, volumetric parts of the skeleton and dead ends, as well as their dependence on the component concentration. Volumetric part of the skeleton near the threshold of leakage makes a negligible part of the full volume.
The Influence Of Solvents On Formation Of The Molecular Geometry Of [{Fe(Salphen)}_2o], Mehmet Kabak, Ayhan Elmali
The Influence Of Solvents On Formation Of The Molecular Geometry Of [{Fe(Salphen)}_2o], Mehmet Kabak, Ayhan Elmali
Turkish Journal of Physics
The crystal structure and magnetic properties of the complex (I)=[$\{$Fe(salphen)$\}_2$\-O]$\cdot$(C$_4$\-H$_8$SO) and (II)=[$\{$Fe(salphen)$\}_2$O]$\cdot$(C$_4$H$_8$O$_2$)\- (salphen H$_2$=N,N'-o-phenylenebis\-(salicylidene-imine)) were recently reported [1, 2]. This complex crystallized with the solvents of dimethyl sulfoxide and dioxane. In this paper, we investigate the influence of the solvents on the formation of the molecular geometry and study the orbital mechanism of the magnetic super-exchange interactions of this complex.
Delay Time Fluctuations Of The Tunnel Josephson Junction In The Case Of Linearly Growing Current, Iman Novruzoglu Askerzade
Delay Time Fluctuations Of The Tunnel Josephson Junction In The Case Of Linearly Growing Current, Iman Novruzoglu Askerzade
Turkish Journal of Physics
Delay time thermal fluctuations intensity of the tunnel Josephson junction for the case of high current rate is calculated.
A New Probe Head Design For The Weak Field Double Resonance Spectrometer, A. Oral Salman, M. Maral Sünnetçi̇oğlu, Rıza Sungur, Gökçe Bi̇ngöl
A New Probe Head Design For The Weak Field Double Resonance Spectrometer, A. Oral Salman, M. Maral Sünnetçi̇oğlu, Rıza Sungur, Gökçe Bi̇ngöl
Turkish Journal of Physics
In order to observe low field $\sigma$ EPR spectra of free radicals a new probe head was designed to work at 1.53 mT. As a double resonance spectrometer, at 1.53 mT the probe head includes both NMR and EPR rf coils. To induce the $\sigma$ transitions EPR rf coil must produce an rf field parallel to the main static field. Various coil designs were examined for this aim and the best results was obtained with a solenoid NMR coil and saddle shaped single turn EPR coil design combination.
A Study Of Events From Si 28 With Emulsion At 4.5 A Gev/C Without Target Fragmentation, A.A. El-Daiem
A Study Of Events From Si 28 With Emulsion At 4.5 A Gev/C Without Target Fragmentation, A.A. El-Daiem
Turkish Journal of Physics
Atotal sample of 1000 inelastic interactions of Si$^{28}$ in emulsion at 4.5 A GeV/c has been used characteristics of projectile fragments. This paper is therefore to devoted to the study of projectile fragments, with special attention to the class of events $n_h$=0, in which the traget nucleus is unwounded. This paper include the multiplicity distributinon and angular distributions of projectile fragments.
Transfer Of Photometric Quantities At Arbitrary Distribution Temperatures, İzmir Mamedbeyli̇, Zafer Ürey, A. Kamuran Türkoğlu
Transfer Of Photometric Quantities At Arbitrary Distribution Temperatures, İzmir Mamedbeyli̇, Zafer Ürey, A. Kamuran Türkoğlu
Turkish Journal of Physics
Characteristics of a photometric setup used for the measurement of photometric quantities at the National Institute of Metrology (UME) in Turkey are reported. A high accuracy method is developed to adjust the filaments of incandescent lamps with respect to the optical axis. The method also provides the basis for low uncertainty distance measurements between lamp filaments and photometers. Transfer of photometric quantities at arbitrary distribution temperatures is examined both theoretically and experimentally, and the results are compared to the calibration values of the Bureau International Des Poids Et Measures (BIPM), Paris, France.
A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra
A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra
Turkish Journal of Physics
The differential cross sections for elastic scattering of ^{16}O from ^{20}Ne have been calculated using an optical potential and distorted wave Born approximation (DWBA) calculations. In the present calculations several prescriptions were tried in the ion-ion potential. The DWBA calculations were performed employing folded real and Woods-Saxon optical potentials for the distorted waves. Inclusion of the exchange process explains the large back-angle cross sections. The elastic scattering differential cross sections are successfully described by calculations in which elastic alpha-transfer amplitudes are coherently added to direct elastic scattering amplitudes.
Optical Anisotropy Of Iron Garnets With Growing Anisotropy, Odil Ochilov
Optical Anisotropy Of Iron Garnets With Growing Anisotropy, Odil Ochilov
Turkish Journal of Physics
The theoretical analysis of the position of principal diachronic directions at magnetization rotation in (100) and (110) planes for the case of growing dichroism axes in random directions was made. The calculations of angular dependencies of dichroic axes (DA) position for different values of the magneto-optical anisotropy parameter, a, have been done. The relations between the growing and magneto-optical dichroism, K/M, and the angle \delta characterizing the direction of principal growing dichroism axes were given. The angular dependences of DA position in epitaxial iron garnet films have been investigated experimentally. The measurements at the different light wavelengths permitted one to …
Alloying Of Aisi 1008 Steel Surfaces By 10ms Nd: Yag Laser Pulses, Raid A. İsmai̇l
Alloying Of Aisi 1008 Steel Surfaces By 10ms Nd: Yag Laser Pulses, Raid A. İsmai̇l
Turkish Journal of Physics
Hardened surfaces were produced on AISI 1008 steel through a laser surface alloying (LSA) technique. Mixture of pure Boron, Silicon, and Carbon powders of the same grain size were deposited on the substrate. The surface was then melted using pulsed Nd:YAG laser (\tau = 10 ms) at an energy of 12 J. The influence of alloying elements on the microstructure and hardness of treated layer was investigated. Dependending on the alloying elements species, different maximum surface hardness, different maximum depth, and different hardness profile could be obtained. The B+Si alloyed zone exhibited maximum hardness to a nominal alloying depth of …
Domain Structures Of Epitaxial Perovskite Ferroelectric Films: Part Ii. Applications, S. Pamir Alpay, Alexander L. Roytburd
Domain Structures Of Epitaxial Perovskite Ferroelectric Films: Part Ii. Applications, S. Pamir Alpay, Alexander L. Roytburd
Turkish Journal of Physics
The use of domain stability maps for epitaxial perovskite ferroelectric films is illustrated with some examples. The equilibrium domain structure and domain fractions as a function of temperature are predicted for PbTiO_3(001) films grown epitaxially on three different substrates: MgO(001), KTaO_3(001), and SrTiO_3(001). Misfit dislocation formation at the growth temperature is found to have a profound effect on both the domain selection and relative domain populations. Theoretical predictions are compared with available experimental data.
Study Of Emission Parameters Of Ir(Iii)-Ba Film System, F. K. Yusifov, A. K. Orujov
Study Of Emission Parameters Of Ir(Iii)-Ba Film System, F. K. Yusifov, A. K. Orujov
Turkish Journal of Physics
Electrophysical properties of Ir(III)-Ba metal-film system have been studied by thermoionic emission (TE), surface ionization (SI) and thermal desorption spectroscopy (TDS) methods. It has been found that the optimum coverage of barium atoms on iridium (III) face is \theta_{opt} = 0.70 \pm 0.05. The dependence of fractional charge of Richardson constant of Ir(III)-Ba metal-film system on coverage \theta of the Ba atoms in the interval 0 \leq \theta \leq 1 has been experimentally obtained. The dependence of work function of Ir(III)-Ba metal-film system on coverage \theta of Ba atoms has been obtained.
Statistics And Size-Quantized Anisotropy Of Electron States In N-Ge And N-Si Films, Bahshali Kuliev, Vugar Gadjiev
Statistics And Size-Quantized Anisotropy Of Electron States In N-Ge And N-Si Films, Bahshali Kuliev, Vugar Gadjiev
Turkish Journal of Physics
The wave functions and energy spectrum of electrons in size-quantized n-Ge and n-Si films are obtained and the anisotropy of the electron state density is investigated. Also, the analytical expressions for the electronic part of heat capacity at the various approximations of electron gas degeneration are obtained.
Compositional Dependence Of Properties Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste
Compositional Dependence Of Properties Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste
Turkish Journal of Physics
Compositional dependence of superconducting transition temperature (T_c) of Bi_2Sr_{3-x}Ca_xCu_2O_{8+x} thin films grown by rf sputtering on single crystal MgO substrates has been investigated. Films have been assessed by considering their initial composition in terms of (Ca+Sr)/Bi ratio with their atomic concentration normalized to Cu:2. It was found that T_{c-zero} of around 80K is achievable for (Ca+Sr)/Bi ratio between 1.4 and 1.65, while T_{c-onset} remains above 90K. Quenching from high temperature increased T_{c-zero,} but it may result in a deterioration in resistivity due to micro cracks induced by the thermal stress.
Electronic Structure Of Optimized Si_{M}H_{N} Clusters: Mindo3 And Am1 Calculations, Şakir Erkoç, Lemi Türker
Electronic Structure Of Optimized Si_{M}H_{N} Clusters: Mindo3 And Am1 Calculations, Şakir Erkoç, Lemi Türker
Turkish Journal of Physics
We have investigated the electronic structure of optimized hydrogenated silicon microclusters. Si_{m}H_{n} (m=2,3,5,6; n = 4,6) have been investigated. The calculations were performed using both MINDO3 and AM1 semiempirical molecular orbital methods.
A Mean Field Model With Two Order Parameters For Three-Phase Coexistence Near The Tricritical Point, S. Sali̇hoğlu
A Mean Field Model With Two Order Parameters For Three-Phase Coexistence Near The Tricritical Point, S. Sali̇hoğlu
Turkish Journal of Physics
This study gives a mean field model with two order parameters for three-phase coexistence near the multicritical point. The critical exponents calculated from our model are the tricritical exponents for the order parameters, susceptibility and the specific heat. Hence, our mean field model describes adequately the tricritical behaviour of a system in the region of three-phase coexistence.
A Mean Field Model For The Coexistence Of Nematic, Smectic A And Smectic C Phases In Liquid Crystals, H. Yurtseven, S. Sali̇hoğlu
A Mean Field Model For The Coexistence Of Nematic, Smectic A And Smectic C Phases In Liquid Crystals, H. Yurtseven, S. Sali̇hoğlu
Turkish Journal of Physics
We present here a mean field model for the nematic-smectic A-smectic C coexistence of a liquid crystal near the NAC point which is a multicritical point. The critical exponents calculated from our model are tricritical expoenents for the order parameters, susceptibility and the specific heat. Our results show that if the NAC point is the tricritical point, then our mean field model describes adequately the liquid crystalline system in the coexistence region of the nematic-smectic A-smectic C phases.
Numerical Calculation Of Energy Loss Rate For E^+ + E^- \Rightarrow \Nu + \Bar{\Nu} Process, A. Aydemir
Numerical Calculation Of Energy Loss Rate For E^+ + E^- \Rightarrow \Nu + \Bar{\Nu} Process, A. Aydemir
Turkish Journal of Physics
The energy loss rate for pair annihilation is calculated numerically in V-A (Fermi theory) and Weinberg-Salam (Standard theory) theories, taking into account also the variation of density at various temperatures using the results obtained in closed form by Chiu, and Schinder, et al. The calculations made by Chiu, and Salpeter, et al., are seen to be parallel to each other. Dicus has calculated energy loss rate for this process only for a few limiting cases since the integrals can not be taken analytically for all \lambda and \nu. The graph drawn for the values we obtained is compared with the …
The Effect Of Spatially Dependent Screening On The Donor Ionization Energy In A Quantum Wire, B.N. Onwuagba
The Effect Of Spatially Dependent Screening On The Donor Ionization Energy In A Quantum Wire, B.N. Onwuagba
Turkish Journal of Physics
The effect of the spatially dependent screening on the ionization energy of a shallow donor in a 1D quantum well wire made of Ga_{1-x}Al_x/GaAs superlattice is presented. A variational approach is used to obtain ionization energy of the on-centre impurity at the origin of the well and the results obtained are compared with the existing values.
Theorems On Three-Term Relations For Hardy Sum, Y. Şi̇mşek
Theorems On Three-Term Relations For Hardy Sum, Y. Şi̇mşek
Turkish Journal of Mathematics
Some three-term and mixed three-term relations for Hardy sums were given by Goldberg [7]. His proofs are based on Bernd's transformation formulae for the logarithms of the classical Theat-functions. Pettet and Sitaramachandararo [9] proved elementary proofs for all of Goldberg's results and also proved some three-term relations of Dedekind sums. In this paper, some new theorems on three-term relations for hardy sums were found by applying derivative operator to three-term polynomial relation. Furthermore, proofs of the reciprocity relations for Hardy sums are presented in a more concise way from the original proofs of Berndt [2, 3, 4] and Goldberg [7].
Characterization Of An All-Optical Device Based On Organic Materials, Hans-Martin Keller, Mark Andreas Bader, Gerd Marowsky
Characterization Of An All-Optical Device Based On Organic Materials, Hans-Martin Keller, Mark Andreas Bader, Gerd Marowsky
Turkish Journal of Chemistry
We present numerical and first experimental results for an all-optical switching device. The device consists of a periodically modulated nonlinear waveguide, where so-called gap solitons stabilize the switching process. The fabrication of Bragg gratings in different polymeric films, e.g. poly(phenylene vinylene), polydiacetylene or polystyrene by excimer laser photoablation was tested. In preparation of further experiments numerical calculations were performed to characterize the device under realistic conditions, including position dependent index modulations and absorption losses. In further time-dependent simulations the transition from the reflecting to the transparent state was investigated in detail. As a main result, the threshold intensity turns out …