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- Critical current density (3)
- High-T_c superconductors (3)
- K-doping (3)
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- 3D J-Resolved NMR spectroscopy. (1)
- A^{III}B^{III}C_2^{VI} compounds (1)
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- CdS(Ag) (1)
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- Crystal growth laboratory (1)
- Disorder. (1)
- Furnace (1)
- Kramers-Kronig Analysis. (1)
- Layer and chained structure (1)
- Magnetic Super - Exchange; Antiferromagnetic Coupling; Crystal Structure. (1)
- Magnetic moment (1)
- Microcanonical molecular dynamics (1)
- Open clusters (1)
- Optical Constant (1)
- Oscillator Fit Procedure (1)
- Phase transition. (1)
- Product operator (1)
- Radioluminescence (1)
- Recombination. (1)
- Si Single Crystals (1)
Articles 1 - 30 of 74
Full-Text Articles in Physical Sciences and Mathematics
An Extended Adiabatic Approach For Nuclear Reactions, Mustafa Yilmaz, Bülent Gönül
An Extended Adiabatic Approach For Nuclear Reactions, Mustafa Yilmaz, Bülent Gönül
Turkish Journal of Physics
In this letter, an alternative approximation is developed for the treatment of breakup process in nuclear reactions, which presents a way of evaluating non-adiabatic corrections to the adiabatic model three-body wavefunction by introducing a more consistent prescription for the continuum n-p center of mass energy. Although the present formalism goes beyond the quasi-adiabatic approach, due to the use of exact continuum channel energies, its application to deuteron involving reactions at medium energies shows that such an approach can not be used in its present form. A possible reason behind this failure is discussed.
Microhardness Creep In Single Crystals Of Tin-Chalcogenides, S. M. Vyas, C. F. Desai, R. C. Shah, G. R. Pandya
Microhardness Creep In Single Crystals Of Tin-Chalcogenides, S. M. Vyas, C. F. Desai, R. C. Shah, G. R. Pandya
Turkish Journal of Physics
SnSe and SnS have been grown by Bridgman- Stockbarger method. Loading time as a function of vickers microhardness has been measured at different temperatures in the range 303 K to 388K. Al measurement of hardness have been carried out on the cleavage planes. The activation energy for creep has been evaluated to be 2.92 and 1.75 K Cal/mole, respectively, for SnSe and SnS crystals.
The Lattice Dynamics Of Bcc Titanium, Kemal Çolakoğlu, Yasemi̇n Özteki̇n Çi̇ftçi̇
The Lattice Dynamics Of Bcc Titanium, Kemal Çolakoğlu, Yasemi̇n Özteki̇n Çi̇ftçi̇
Turkish Journal of Physics
Using in measurements of the phonon frequencies of bcc Titanium, the lattice dynamical calculations are performed on the same phase by using the Third-neighbour Clark-Gazis-Wallis(CGW) model. The theory is used to compute the phonon dispersion curves, the frequency spectra and the lattice spesific heat of the studied phase. The obtained results are compared with the available experimental data.
Properties Of Ag-Doped Bi_{(1.6)}Pb_{(0.4)}Sr_2ca_3cu_{(4-X)}Ag_Xo_Y (2234) Oxides Prepared By S.S.R. Method, Süleyman Bolat, E. Yanmaz, H. Cömert
Properties Of Ag-Doped Bi_{(1.6)}Pb_{(0.4)}Sr_2ca_3cu_{(4-X)}Ag_Xo_Y (2234) Oxides Prepared By S.S.R. Method, Süleyman Bolat, E. Yanmaz, H. Cömert
Turkish Journal of Physics
The effect of Ag-doping Bi$_{1.6}$Pb$_{0.4}$Sr$_{2}$Ca$_{3}$Cu$_{4-x}$Ag$_{x}$O$_{y}$ compounds (x=0.0-1.0), prepared by conventional Solid-State-Reaction (SSR) technique, was studied using x-ray diffraction (XRD) and electrical resistivity. The high-T$_{c}$ fraction of the 2223 phase, formed from the nominal composition of 2234, decreases with increasing Ag content. From lattice parameter calculations it follows that Ag-doping the unit cell phase of (Bi,Pb)$_{2}$Sr$_{2}$Ca$_{2}$Cu$_{3}$O$_{y}$ is limited to the value of x$\leq$0.1. The zero resistance critical temperature (T$_{c,zero}$) was determined from the resistivity curves for all samples. The value of T$_{c,zero}$ decreases slightly to 106 K for x$\leq$0.4 and when the nominal silver content increases up to x=0.7 or more …
Multi-Species Asymmetric Exclusion Process In Ordered Sequential Update, M. Ebrahi̇m Fouladvand, Farhad Jafarpour
Multi-Species Asymmetric Exclusion Process In Ordered Sequential Update, M. Ebrahi̇m Fouladvand, Farhad Jafarpour
Turkish Journal of Physics
A multi-species generalization of the asymmetric simple exclusion process (ASEP) is studied in ordered sequential and sub-lattice parallel updating schemes. In this model, particles hop with their own specific probabilities to their rightmost empty site and fast particles overtake slow ones with a definite probability. Using Matrix Product Ansatz (MPA), we obtain the relevant algebra, and study the uncorrelated stationary state of the model both for an open system and on a ring. A complete comparison between the physical results in these updates and those of random sequential introduced in [20,21] is made.
Product Integral Representations Of Wilson Lines And Wilson Loops And Non-Abelian Stokes Theorem, Robert L. Karp, Freydoon Mansouri, Jung S. Rno
Product Integral Representations Of Wilson Lines And Wilson Loops And Non-Abelian Stokes Theorem, Robert L. Karp, Freydoon Mansouri, Jung S. Rno
Turkish Journal of Physics
We make use of product integrals to provide an unambiguous mathematical representation of Wilson line and Wilson loop operators. Then, drawing upon various properties of product integrals, we discuss such properties of Wilson lines and Wilson loops as approximating them with partial sums, their convergence, and their behavior under gauge transformations. We also obtain a surface product integral representation for the Wilson loop operator. The result can be interpreted as the non-abelian version of Stokes theorem.
Associations Of X-Ray Binaries With Open Clusters And Supernova Remnants, Eni̇s Tuncer, H. Guseinov, Ü. Kiziloğlu, A. O. Allakhverdiev
Associations Of X-Ray Binaries With Open Clusters And Supernova Remnants, Eni̇s Tuncer, H. Guseinov, Ü. Kiziloğlu, A. O. Allakhverdiev
Turkish Journal of Physics
Searching for X-ray binaries projected on open clusters (OCs) and supernova remnants (SNRs), associations of X-ray binaries with OCs and SNRs in the Galaxy are discussed. Three of the high mass X-ray binaries (HMXBs) and four of the low mass X-ray binaries (LMXBs) are projected on open clusters. Five of HMXBs and six of LMXBs are projected on SNRs. The number of the HMXB projections are less than the LMXBs, which is not expected and is surprising since the objects in this study, except the LMXBs, are all young objects. Such associations help us improve distance and age estimates of …
Ferromagnetic Transitions In Ni-Mn Alloys, F. Boakye, R. K. Nkum
Ferromagnetic Transitions In Ni-Mn Alloys, F. Boakye, R. K. Nkum
Turkish Journal of Physics
Ferromagnetic transitions in nickel and nickel-manganese alloys have been studied using resistivity-temperature measurements from 800 to 77 K. The results establish the transition temperature of nickel as 610 K and the transition temperature is shifted to lower values as the concentration of Mn in the alloy is increased. Analysis of the resistivity results near the ordering temperature \( (T
Radioluminescent Properties Of Cds(Ag) Crystals, Ruhi̇ Kaplan, F. Esen Özsan
Radioluminescent Properties Of Cds(Ag) Crystals, Ruhi̇ Kaplan, F. Esen Özsan
Turkish Journal of Physics
The radioluminescent proporties of silver-doped cadmium sulphide, CdS(Ag), crystals excited by 5.5 MeV $ \alpha $-particles from an $ ^{241}$Am radioactive source have been investigated. The emission spectra, decay profiles and thermal quenching curves were obtained accurately at temperatures between 80 K and 300 K. Two main radioluminescent emission bands centered at about 5760 \AA\ and 5940 \AA\ were observed. Their decay curves were found to be fast and nonexponential. From the thermal quenching of radioluminescence, the activation energies of centers responsible for these emissions were determined. The results are interpreted as the radioluminescence is possibly due to donor-acceptor pair …
A Glancing Incidence Exafs Study Of Evaporated Silver Films On Glass, Ahmet Bulut, Bünyami̇n Karabulut, Engi̇n Başaran, James Robinson
A Glancing Incidence Exafs Study Of Evaporated Silver Films On Glass, Ahmet Bulut, Bünyami̇n Karabulut, Engi̇n Başaran, James Robinson
Turkish Journal of Physics
A glancing incidence EXAFS experiment has been carried out with evaporated silver films on glass substrates. Prior to EXAFS data collection, a reflectivity curve was performed from which the critical angle for total external reflection of x-rays from surface were determined. The analysed EXAFS data revealed that there is a reduction in the coordination number and an increase in Debye-Waller factor compared to bulk values. These changes were explained in terms of grain size effect and the surface effects of the silver film.
Consistency Of The Born Approximation For Aharonov-Bohm Scattering With Massless Spin-1/2 Particles, Müge Boz, Namik Kemal Pak
Consistency Of The Born Approximation For Aharonov-Bohm Scattering With Massless Spin-1/2 Particles, Müge Boz, Namik Kemal Pak
Turkish Journal of Physics
The second order contribution for the relativistic scattering of massless spin-$\frac{1}{2}$ particles from an infinitely long solenoid, in the context of covariant perturbation theory, is calculated and shown to vanish. Thus, Born approximation is consistent for this case as well.
Temperature Dependence Of Vickers Microhardness And Creep Study Of In_X Bi_{2-X} Te_3 Crystals, G. R. Pandya, S. R. Bhavsar, C. F. Desai
Temperature Dependence Of Vickers Microhardness And Creep Study Of In_X Bi_{2-X} Te_3 Crystals, G. R. Pandya, S. R. Bhavsar, C. F. Desai
Turkish Journal of Physics
Temperature dependence of Vickers microhardness of ln$_x$ Bi$_{2-x}$ Te$_3$ single crystals with x ranging from 0.1 to 0.5 has been studied. Loading time dependence of microhardness at different temperatures has been used for creep study in the temperature range 300 K to 400 K. The activation energy for indentation creep of the crystals has been evaluated.
Generalized 2d Yang-Mills Theories: Large-N Limit And Phase Structure, Masoud Alimohammadi
Generalized 2d Yang-Mills Theories: Large-N Limit And Phase Structure, Masoud Alimohammadi
Turkish Journal of Physics
After review the 2D Yang--Mills theories (YM$_2$) and its large--$N$ behaviour, the Generalized 2D Yang--Mills theories (gYM$_2$) and their partition functions on a general two--dimensional Riemann surface are discussed.The large--$N$ behaviour of these models is studied in weak regime, and in strong regime, we restrict ourselves to $\phi^4$ gYM$_2$. We show that this model has a third order phase transition, similar to ordinary YM$_2$ theory.
Spinors And Positive Mass, Malcolm Ludvigsen
Spinors And Positive Mass, Malcolm Ludvigsen
Turkish Journal of Physics
As an example of how spinor methods can be applied to the positive-mass theorem, a simple, spinor-based proof of the theorem is presented for the case of a single black hole. Generalisations of the theorem are also discussed.
The Decay Of A Black Hole As A Quantum Dissipative Process, Carl Wolf
The Decay Of A Black Hole As A Quantum Dissipative Process, Carl Wolf
Turkish Journal of Physics
By considering the decay of a black hole as a result of the interaction of a quantum system with a dissipative vacuum, or in terms of string theory, the interaction of localized string modes with non-local string modes, we demonstrate how the single parameter representing dissipation can be calculated in terms of known fundamental constants. In view of the uncertainty embodied in all the present theories of black hole decay it is suggested that the approach of this note might provide fresh insight to the problem of black hole decay. P.A.C.S.: 98.80-Dr Cosmology
The Effect Of Various Experimental Parameters On Glow Peaks And Trapping Parameters Of Caf_2:Dy (Tld-200) Crystals, A. Necmeddi̇n Yazici, M. Yakup Hacii̇brahi̇moğlu, Meti̇n Bedi̇r
The Effect Of Various Experimental Parameters On Glow Peaks And Trapping Parameters Of Caf_2:Dy (Tld-200) Crystals, A. Necmeddi̇n Yazici, M. Yakup Hacii̇brahi̇moğlu, Meti̇n Bedi̇r
Turkish Journal of Physics
In the present study, thermoluminescence glow curves of CaF$_{2}$:Dy (TLD-200) crystals have been investigated in detail between the temperature region 300-550 K. The number of peaks and their trapping parameters (E, s and b) have been determined using the computerized glow curve fitting, peak shape and isothermal decay methods. In addition, the effect of storage times at room temperature, dose levels and heating rates on the trapping parameters have been investigated in detail by using computerized glow curve deconvolution method (CGCD) using first and general order kinetic equations.
Effects Of Disorder On The Drag Rate In Double Quantum-Wire Systems, B. Tanatar
Effects Of Disorder On The Drag Rate In Double Quantum-Wire Systems, B. Tanatar
Turkish Journal of Physics
We study the Coulomb drag rate for electrons in a double quantum-wire structure in the presence of disorder. We use the particle number-conserving relaxation-time approximation to phenomenologically broaden the response functions entering the drag rate expression to account for the disorder effects. In contrast to the usual low-temperature regime investigated by various researchers, we focus our attention on the high-temperature drag rate to which plasmon modes are known to make substantial contribution. The full wave vector and frequency dependent random-phase approximation (RPA) at finite temperature and disorder strength is employed to describe the effective interlayer Coulomb interaction. The interplay between …
Steady States Of Dynamically Coupled Two-Species Systems, Muntasi̇r Barma, Sri̇ram Ramaswamy
Steady States Of Dynamically Coupled Two-Species Systems, Muntasi̇r Barma, Sri̇ram Ramaswamy
Turkish Journal of Physics
We study the steady states of two stochastic lattice models with two species of particles, where the local mobility of one species depends on the spatial distribution of the other. The eigenvalues of a $2\times 2$ matrix of couplings can develop imaginary parts, and the question arises whether this implies an instability to a macroscopically different steady state. In the first model, where the mobility depends on the local density of the other species, we show that the system undergoes macroscopic phase separation. In the second model, where the mobility depends on the second derivative of the density of the …
Global Results In Space Of Inter-Monomer Interactions For Hp Lattice Model, M. R. Ejtehadi̇, V. Shahrezaei̇, N. Hamedani̇
Global Results In Space Of Inter-Monomer Interactions For Hp Lattice Model, M. R. Ejtehadi̇, V. Shahrezaei̇, N. Hamedani̇
Turkish Journal of Physics
Using the ground state candidates for Hydrophobic-Polar lattice model on a two dimensional square lattice, we exactly enumerate the native states of proteins with length up to 20 for a wide range of energy parameters. We find the reduced set of contact maps, ground state candidates, perfectly stable sequences and designability of configurations.
Chaos In Closed Isotropic Cosmological Models With Steep Scalar Field Potential, A. V. Toporensky
Chaos In Closed Isotropic Cosmological Models With Steep Scalar Field Potential, A. V. Toporensky
Turkish Journal of Physics
The dynamics of closed scalar field FRW cosmological models is studied for several types of exponentially and more than exponentially steep potentials. The parameters of scalar field potentials which allow a chaotic behaviour are found from numerical investigations. It is argued that analytical studies of equation of motion at the Euclidean boundary can provide an important information about the properties of chaotic dynamics. Several types of transition from chaotic to regular dynamics are described.
Thermal Stability Of Fe_{85.5}B_{14.5} Metallic Glass, Asghari Maqsood, Ashfaq Ahmad
Thermal Stability Of Fe_{85.5}B_{14.5} Metallic Glass, Asghari Maqsood, Ashfaq Ahmad
Turkish Journal of Physics
The thermal stability and crystallization behaviour of metallic glass Fe\( _{85.5} \)B\( _{14.5} \) were investigated by Dynamic Temperature Resistivity Measurement (DTRM) technique from room temperature to 1050K in forward and reverse mode at a heating rate of 40 K/hr. The slope of Resistivity-Temperature-Curve (RTC) changes sign and magnitude at the temperature where the transition takes place. Differential Thermal Analysis (DTA) was carried out at the heating rates of 10, 20, 30 \& 40 K/min. A comparison of the results of DTRM and DTA measurements shows that crystallization in this alloy is two-stage process. Activation energy for two crystallization steps …
The Magnetic Super-Exchange Coupling In Copper(Ii) Acetate Monohydrate And A Redetermination Of The Crystal Structure, Ayhan Elmali
The Magnetic Super-Exchange Coupling In Copper(Ii) Acetate Monohydrate And A Redetermination Of The Crystal Structure, Ayhan Elmali
Turkish Journal of Physics
The magnetic properties and redetermination of crystal structure of copper(II) acetate monohydrate have been studied. The copper(II) centers are separated by 2.617(1) \AA \ and antiferromagnetically coupled (-2J = 292.2 cm$^{-1}$), which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.2 to 300 K. The magnetic moment at 300 K is about 2.1 Bohr magnetons while 0.1 Bohr magnetons at 4.2 K. The magnetic susceptibility is at a maximum near 250 K and decreases rapidly as the temperature is lowered to liquid helium temperature.
Antiferromagnetic Transition In \Alpha-Mn-Fe System, R. K. Nkum, F. Boakye
Antiferromagnetic Transition In \Alpha-Mn-Fe System, R. K. Nkum, F. Boakye
Turkish Journal of Physics
Antiferromagnetic transition in $\alpha$-Mn-Fe alloys has been studied using resistivity-temperature measurements from 300 to 1.5 K. The results indicate that the transition temperature $T_N$ of the samples studied increases with increasing Fe concentration. This suggests that the N\'{e}el temperature is affected by Fe. Also, Fe plays a significant role in the local disorder on the magnetic moment of the ions in the complex manganese structure.
Synthesis And Characteristics Of Nickel Manganite By Lithiation, S. V. Salvi, M. R. Parab
Synthesis And Characteristics Of Nickel Manganite By Lithiation, S. V. Salvi, M. R. Parab
Turkish Journal of Physics
Spinel nickel manganite has been synthesized using ceramic technique, from (2MnO$_{2}$+NiO) mixture reduced using LiAlH$_{4}$. Powder X-ray diffractometry (XRD) indicates the formation of cubic spinel (a=8.33 A^o), while IR absorption spectral features are rather broad, though similar to those of spinel. The d.c. electrical conductivity of the ceramic is much smaller than that reported for NiMn$_{2}$O$_{4}$. Even though the band gap remains the same, when the sintering temperature is increased from 950^oC to 1100 ^oC, all other changes are insignificant except that the porosity and particle size nearly halve. The characteristics of the system are discussed in terms of `lithiation'.
The Absorption Properties Of P-Type Tlin_X Ga_{(1-X)} Se_2 And Tlgase_2, Beki̇r Gürbulak, Muhammet Yildirim, Aytunç Ateş, Sebahatti̇n Tüzemen, Yahya Kemal Yoğurtçu
The Absorption Properties Of P-Type Tlin_X Ga_{(1-X)} Se_2 And Tlgase_2, Beki̇r Gürbulak, Muhammet Yildirim, Aytunç Ateş, Sebahatti̇n Tüzemen, Yahya Kemal Yoğurtçu
Turkish Journal of Physics
$p-TlGaSe_2$, $p-TlIn_{0.3}Ga_{0.7}Se_2$ and $p-TlIn_{0.5}Ga_{0.5}Se_2$ single crystals were grown by the modified Bridgman-Stockbarger method in our crystal growth laboratory. The absorption measurements were carried out on $p-TlIn_xGa_{(1-x)}Se_2$ samples in temperature range 10-300 K in steps of 10 K. The binding energies of $p-TlGaSe_2$, $p-TlIn_{0.3}Ga_{0.7}Se_2$ and $p-TlIn_{0.5} Ga_{0.5}$ $Se_2$ were obtained as \\ 35.0 meV, 16.5 meV and 14.5 meV, respectively. THe direct band gaps were calculated as 2.244 eV, 2.195 eV, 2.164 eV in $p-TlGaSe_2$, 2.158 eV, 2.131 eV, 2.098 eV in $p-TlIn_{0.3}Ga_{0.7}Se_2$, and 2.107 eV, 2.075 eV, 2.019 eV in $p-TlIn_{0.5}Ga_{0.5}Se_2$ respectively, at sample temperatures of 10 K, 140 K …
Quark And Lepton Masses From Fundamental Algebra With Exact Color Symmetry, Engi̇n Arik, Meti̇n Arik, Ufuk Kayserilioglu, M. Burcin Unlu
Quark And Lepton Masses From Fundamental Algebra With Exact Color Symmetry, Engi̇n Arik, Meti̇n Arik, Ufuk Kayserilioglu, M. Burcin Unlu
Turkish Journal of Physics
We propose a deformed algebra of creation and annihilation operators relating quark-lepton states. A diagonal mass operator with three parameters together with the three deformation parameters of the algebra gives a reasonable fit to observed quark-lepton masses.
On Integrable Systems Related To Semisimple Lie Groups, G. A. Keri̇mov
On Integrable Systems Related To Semisimple Lie Groups, G. A. Keri̇mov
Turkish Journal of Physics
Quantum scattering systems related to the noncompact semisimple Lie groups G in the sense that the Hamiltonian of the system can be written as a function of the Casimir operator of G are considered. The S-matrix for such systems are defined in terms of an interwining operator of underling symmetry group G.
Barrier Heights Of Antimony / And Bismuth / P -Silcon (100) Junctions, A. A. Oberafo, A. Z. Ziriki
Barrier Heights Of Antimony / And Bismuth / P -Silcon (100) Junctions, A. A. Oberafo, A. Z. Ziriki
Turkish Journal of Physics
Junctions were fabricated in vacuum of about $10^{-5}$ Torr by thermal evaporation of Sb or Bi onto chemically etched $p$-type silicon (100) substrates. The electrical properties were studied by current voltage (I-V) measurements. Some of the Sb and Bi junctions were heated-treated for $\frac{1}{2}$ hr at 200 and 150^oC, respectively. The barrier height (BH) was equal to 0.64 eV for both as-deposited and heat-treated Sb junctions, while it was 0.56 and 0.74 eV for as-deposited and heat-treated Bi Junctions, respectively. These observatimons indicate that for Sb junctions, annealing at a temperature of 200^oC resulted only in partial elimination of any …
Mass-Radius Relations For Helium White Dwarfs, Ri̇kkat Ci̇velek, Ni̇lgün Kiziloğlu
Mass-Radius Relations For Helium White Dwarfs, Ri̇kkat Ci̇velek, Ni̇lgün Kiziloğlu
Turkish Journal of Physics
We studied the static mass-radius relation of white dwarf stars with masses greater than 0.45 $M_\odot$. We assumed pure degenerate helium interiors at a finite temperature with luminosity-mass ratio due to neutrino energy loss. We compared the obtained M-R relation with those of other writers.
The Growth Of P-Type A^{Iii} B^{Iii} C_2^{V I} Single Crystals, Beki̇r Gürbulak, Cevdet Coşkun, Seydi̇ Doğan, Aytunç Ateş, Yahya Kemal Yoğurtçu
The Growth Of P-Type A^{Iii} B^{Iii} C_2^{V I} Single Crystals, Beki̇r Gürbulak, Cevdet Coşkun, Seydi̇ Doğan, Aytunç Ateş, Yahya Kemal Yoğurtçu
Turkish Journal of Physics
$A^{III}B^{III}C_2^{VI}$ single crystals were grown by the modified Bridgman-Stockbarger method, a procedure similar to direct freezing in our crystal growth laboratory. $A^{III}B^{III}C_2^{VI}$ compounds are collected into two groups (III. group: TI, Ga, In and VI. group: Se, S, Te): 1. TlGaSe$_2$, TlGaS$_2$ and TlInS$_2$ have layer structure. 2. TlInSe$_2$, TlInTe$_2$ and TlGaTe$_2$ have chained structure. The main reasons such crystals grown with this method is similar to the direct freezing method because 1) quality of crystals is the same as crystals grown by other methods, and 2) growth time of crystals is shorter by about 5-10 days. None of the …