Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Thin films (18)
- Optical properties (12)
- Solar cell (10)
- ZnO (10)
- Chalcogenide glasses (9)
-
- Thermodynamics (8)
- Cosmology (7)
- DFT (7)
- Density functional theory (7)
- Lattice parameter (7)
- Band gap (6)
- Elastic scattering (6)
- Electrical properties (6)
- Energy levels (6)
- Phase transition (6)
- Photoconductivity (6)
- Quantum well (6)
- Spray pyrolysis (6)
- X-ray diffraction (6)
- Bulk modulus (5)
- Cosmic ray (5)
- Decoherence (5)
- Dirac equation (5)
- Diurnal (5)
- Electrical conductivity (5)
- Entropy (5)
- Nanoparticles (5)
- Nuclear structure (5)
- Quantum dot (5)
- Schrödinger equation (5)
- Publication Year
Articles 991 - 1020 of 1382
Full-Text Articles in Physical Sciences and Mathematics
The Effects Of Nonstoichiometry In High - T_C Superconducting Properties Of Yba_2cu_{3 + X}O_{7 - \Delta}, Beniah Ndudim Onwuagba
The Effects Of Nonstoichiometry In High - T_C Superconducting Properties Of Yba_2cu_{3 + X}O_{7 - \Delta}, Beniah Ndudim Onwuagba
Turkish Journal of Physics
Polycrystalline samples of high T_c superconductor YBa_2Cu_{3 + x}O_{7 - \delta} with 0 \leqslant x \leqslant 0.5 were grown. The effects of nonstoichiometry on the resistance slope above transition temperature T_c and X-ray diffraction patterns for these samples were investigated. In the diffraction patterns obtained, apart from some new features in the peaks, these polycrystalline samples show predominantly 123 phase.
Some Characteristic Properties, Vithal Bhivaba Pujari, V. B. Gaikwad, E. U. Masumdar, P. D. More, L. P. Deshmukh
Some Characteristic Properties, Vithal Bhivaba Pujari, V. B. Gaikwad, E. U. Masumdar, P. D. More, L. P. Deshmukh
Turkish Journal of Physics
This paper presents some information regarding (Cd, Hg) Se materials synthesized by a simple chemical growth process and the structural, optical and electrical transport properties. The growth of these films depends on various preparative parameters and deposition conditions such as concentration of the starting materials, pH, temperature, time, speed of mechanical churning, etc., and the reaction kinetics suggests that the films grow into two different phases: one, initialy an almost linear phase; and second, a saturation phase. The deposits were analysed chemically and by an EDS techniques. It has been seen that more than 70% of the materials taken in …
Mathematical Modeling Of Plasmachemical Processes, Meli̇k-Aslanova Tamilla
Mathematical Modeling Of Plasmachemical Processes, Meli̇k-Aslanova Tamilla
Turkish Journal of Physics
In this research, we studied the kinetics of plasmachemical processes in quasiequilibrium and nonequilibrium conditions. The example of methane conversion into acetylene showed that the most efficient plasmachemical process may be achieved under nonequilibrium conditions, especially, when the reaction was stimulated by vibrational excitation of molecules.
A New Metallicity Calibration For Dwarf Stars With Rgu-Photometry, Sali̇h Karaali̇, Selçuk Bi̇li̇r
A New Metallicity Calibration For Dwarf Stars With Rgu-Photometry, Sali̇h Karaali̇, Selçuk Bi̇li̇r
Turkish Journal of Physics
We have adopted the procedure of Carney to obtain a metallicity calibration for dwarfs utilising RGU-photometry. For this purpose we selected 76 dwarfs of different metallicities from Carney and from Strobel et al., and evaluated their \delta (U-G) ultra-violet excess relative to the Hyades by transforming UBV magnitudes to RGU via the metallicity dependent equations of Ak-Güngör. The \delta_{0.6}/\delta M normalized factors of Sandage transform \delta (U-G) excess at any G-R to \delta \equiv \delta_{1.08}, i.e. the ultra-violet excess at G-R = 1.08 mag, corresponding to B-V = 0.60 mag in the UBV-system. Finally, the (\delta, [Fe/H]) pairs were shown …
Effect Of The Oxygen/Halogen Ratio On The Physical Properties Of Some Sodium-Boro-Vanadate Glasses, Ahmed Gamal El-Din Mostafa
Effect Of The Oxygen/Halogen Ratio On The Physical Properties Of Some Sodium-Boro-Vanadate Glasses, Ahmed Gamal El-Din Mostafa
Turkish Journal of Physics
Four different glass systems of the sodium boro-vanadate type containing halogen ions, were prepared by melting at 1000°C for three hours and annealed at 300°C. These glasses were investigated using dc conductivity, density, molar volume and magnetic susceptibility measurements. It was found that the activation energy shows a decrease as the halogen ions were increased, which was attributed to the increase in the mobility of sodium ions and the gradual formation of some terminal non-bridging halogens, in addition to the electron hopping between the different oxidation states of vanadium. The activation energy values for glasses containing iodine ions was less …
Paramagnetic Defects In \Gamma-Irradiated, Pure And Doped (With As, Cl And Br) Selenium, Ibrahimgizi Salima Mekhtieva, Ibrahimogli Namig Ibragimov, Isaogli Abasat Isaev, Zeinalogli Vasif Zeinalov, Arifogli Eldar Mamedov
Paramagnetic Defects In \Gamma-Irradiated, Pure And Doped (With As, Cl And Br) Selenium, Ibrahimgizi Salima Mekhtieva, Ibrahimogli Namig Ibragimov, Isaogli Abasat Isaev, Zeinalogli Vasif Zeinalov, Arifogli Eldar Mamedov
Turkish Journal of Physics
This paper presents results of an EPR spectrum investigation of \gamma-irradiated (Co^{60} dose 10^{7} Rad) glasses Se, SeCl_{x}, Se_{0.95}As_{0.05}Cl_{x} and Se_{0.95}As_{0.05}Br_{x} (x=0.001--0.1) at 77 K. An analysis of spectra reveals that two types of paramagnetic radiation-induced defects arise (broken bonds localized on Se and As atoms) from the irradiation of such chalcogenide glasses.
Monitoring The Effect Of Recrystallization And Quenching In Almg_{X} Alloy By Pat, A. Ashour, Nour Zaki El-Said, Emad A. Badawi
Monitoring The Effect Of Recrystallization And Quenching In Almg_{X} Alloy By Pat, A. Ashour, Nour Zaki El-Said, Emad A. Badawi
Turkish Journal of Physics
Positron annihilation technique (PAT) lifetime measurements have been carried out on AlMg_{x} samples (x = 0.23, 0.85, 1.27 and 1.4 at %) with point defects and dislocations introduced by plastic deformation at room temperature. Clustering of vacancies was observed by quenching using PAT. The samples were annealed at 573 K for 12 hours to homogenize and divided into two sets. The first set of AlMg_{x} (x = 0.23, 0.85 and 1.4 at %) was deformed to 10, 25 and 35% thickness reduction. Isochronal annealing was studied in the range of 300-550 K. In the second set of measurements, AlMg_{x} (x …
Characterization Of The Sno_{2}/P Contact Resistance And Sno_{2} Properties In Operating A-Si:H P-I-N Solar Cells, Ruhi̇ Kaplan, Bengü Kaplan
Characterization Of The Sno_{2}/P Contact Resistance And Sno_{2} Properties In Operating A-Si:H P-I-N Solar Cells, Ruhi̇ Kaplan, Bengü Kaplan
Turkish Journal of Physics
A method is presented to characterize the TCO/p contact and the TCO sheet resistance in a-Si TCO/p-i-n superstrate devices. It is extremely useful for understanding resistance losses in modulus and diagnosing how plasma processing influences the TCO layers. Analysis of 4-terminal dark J-V measurements as a function of temperature on devices with varying TCO geometry yields the TCO/p contact resistance R_{TCO/p}, its activation energy E_{a} or barrier height, and the TCO sheet resistance R_{SH} in an integrated device structure. The method is applied to devices fabricated on different brands of commercial SnO_{2} substrates with different p-layers. Important new results are …
Measurement Of Photon-Induced K X-Rays Production Cross Sections For Elements With 62 \Le Z \Le 74, Sabri̇ye Seven
Measurement Of Photon-Induced K X-Rays Production Cross Sections For Elements With 62 \Le Z \Le 74, Sabri̇ye Seven
Turkish Journal of Physics
X-ray production cross sections of K\alpha_{1}, K\alpha_{2}, K\beta'_{1} (= K\beta {\ss}_{1} + K\beta_{3} + K\beta_{5}) and K\beta'_{2} (= K\beta_{2} + K\beta_{4} + transitions from higher levels) lines have been measured and theoretically calculated for six elements with 62 \le Z \le 74 at excitation energy of 78.706 keV, the weighted avarage of K conversion x-rays emitted from Bi. The experimental results were compared with theoretically predicted values based on relativistic Hartree-Slater and Hartree-Fock theories, a comparison that was found to be in good agreement to within the experimental uncertainties.
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.
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.
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 …
Photospheric Line Profiles In Deneb (A2 Iae), Berahi̇tdi̇n Albayrak, Cemal Aydin, Dursun Koçer
Photospheric Line Profiles In Deneb (A2 Iae), Berahi̇tdi̇n Albayrak, Cemal Aydin, Dursun Koçer
Turkish Journal of Physics
In this study, the strong lines were examined to determine the effect of velocity gradient due to mass loss on the line profiles in the atmosphere of Deneb. The lines are formed in the optical depth range -1.14 < log \tau < -0.14. None were found to exibit any asymmetry.
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.
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.
On The Statistical Properties Of A Q-Oscillator, Abdullah Algin
On The Statistical Properties Of A Q-Oscillator, Abdullah Algin
Turkish Journal of Physics
Several statistical properties of the Coon-Baker-Yu (CBY) q-oscillator algebra are discussed. Particular emphasis is given to a careful derivation of second quantized particle statistics obtained via the CBY q-oscillator. It is outlined that, beside other limiting cases, the limit q = 0 of the CBY q-oscillator gives the Cuntz oscillator and the Fock space properties of both of these oscillators lead to various interesting results.
Influence Of Above-Molecular Structure, Electronic And Ionic Phenomena On Durable Properties Of Polymer Dielectrics In The Electric Field, T. M. Veliyev, S. A. Abasov, M. J. Zeynalova, E. Hali̇lova, H. Memedov, I. Askerov, S. Aydoğu
Influence Of Above-Molecular Structure, Electronic And Ionic Phenomena On Durable Properties Of Polymer Dielectrics In The Electric Field, T. M. Veliyev, S. A. Abasov, M. J. Zeynalova, E. Hali̇lova, H. Memedov, I. Askerov, S. Aydoğu
Turkish Journal of Physics
Influence of above-molecular structure (AMS) on electrothermoluminescence, the altering time and the mechanic time of polymer dielectrics in strong electric fields that depend on temperature have been investigated. It has been shown that change of AMS considerably influenced the processes of injection and stabilization of charges as well as the solidity properties of polymers. It has been determined that the relaxation translations in large spherolite samples were observed at lower temperatures than the relaxation translations in small spherolite samples.
Is There An Age Of The Universe Problem After The Hipparcos Data?, Murat Özer
Is There An Age Of The Universe Problem After The Hipparcos Data?, Murat Özer
Turkish Journal of Physics
We have reanalyzed the age of the universe problem under the assumption that the lower limit on the age of the globular clusters is \sim11 Gyr, as predicted by the recent Hipparcos data. We find that the globular cluster and the expansion ages in a standard \lambda=0 universe are consistent only if the present value H_0 of the Hubble constant is \leq 60{\rm kms}^{-1}Mpc^{-1}. If H_0>60{\rm kms}^{-1}Mpc^{-1} some kind of modification of the standard \lambda=0 model is required. Invoking a (time-independent) cosmological term \lambda in the Einstein field equations, as has been done frequently before, we have found that …
Effect Of Flux Re-Distribution On Resistivity In Granular Ybco, Muhammad Muneeb Asim, Syed Khurshid Hasanain
Effect Of Flux Re-Distribution On Resistivity In Granular Ybco, Muhammad Muneeb Asim, Syed Khurshid Hasanain
Turkish Journal of Physics
Dc resistivity of a zero-field cooled YBCO was previously studied as a function of angle between applied field and transport current. The resistivity followed a sin^{2}\theta variation that was understood as a consequence of Lorentz force like effect. The resistivity deviated from the harmonic curve giving a minimum at low angles before following the true sin^{2}\theta behavior. The angle corresponding to minimum voltage \theta_{min} has been thoroughly studied in this paper as a function of applied field, transport current and temperature. sin^{2}\theta behavior of resistivity is not affected by the fields below Hc1 at their respective temperatures. The angle \theta_{min} …
Schrödinger Equation Solutions For Small R And Resulting Functional Relations, Harry A. Mavromatis
Schrödinger Equation Solutions For Small R And Resulting Functional Relations, Harry A. Mavromatis
Turkish Journal of Physics
The Schrödinger equation is examined for small r (i.e. one step beyond the limit r \rightarrow 0) for the cases V(r) \rightarrow r^k, (k>0), and V(r) \rightarrow r^{-k} (0
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.
The Temperature Dependence Of Dark Conductivity In Hydrogenated Amorphous Sin_X Films, Hüseyi̇n Tolunay, İlker Ay
The Temperature Dependence Of Dark Conductivity In Hydrogenated Amorphous Sin_X Films, Hüseyi̇n Tolunay, İlker Ay
Turkish Journal of Physics
Thin film samples of hydrogenated amorphous silicon nitride with varying nitrogen content were prepared by conventional plasma deposition from a mixture of SiH_4 and NH_3 . The dark conductivity (\sigma_d) of the films have been measured in the temperature range 420 K - 100 K. The conductivity is thermally activated with a single activation energy down to 250 K and conduction is dominated by electrons in extended states. A strong decrease is observed sigma _d when the nitrogen content is increased.
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.
A Correlation Of Thin Lens Approximation To Thick Lens Design By Using Coddington Factors In Lens Design And Manufacturing, Ömer Faruk Farsakoğlu, D. Mehmet Zengi̇n, Hi̇kmet Kocabaş
A Correlation Of Thin Lens Approximation To Thick Lens Design By Using Coddington Factors In Lens Design And Manufacturing, Ömer Faruk Farsakoğlu, D. Mehmet Zengi̇n, Hi̇kmet Kocabaş
Turkish Journal of Physics
The effect of Coddington factors on aberration functions has been analysed using thin lens approximation. Minimizing spherical aberrations of singlet lenses using Coddington factors in lens design depending on lens manufacturing is discussed. Notation of lens test plate pairs used in lens manufacturing is also presented in terms of Coddington shape factors.
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.
The Investigation Of The Thermoluminescence Emission Bands Of Lif:Mg,Ti (Tld-100) By A Simple Developed Model, A. Necmeddi̇n Yazici, Z. Öztürk, M. Bedi̇r
The Investigation Of The Thermoluminescence Emission Bands Of Lif:Mg,Ti (Tld-100) By A Simple Developed Model, A. Necmeddi̇n Yazici, Z. Öztürk, M. Bedi̇r
Turkish Journal of Physics
In this study, a new simple model based on the classical treatment of lattice vibrations and the Franck-Condon principle is developed to describe the shape of thermoluminescence (TL) emission bands of crystalline solids. According to developed model, shape of the emission band has a Gaussian form and depends on just two physical parameters: peak energy E_{0} and broadening of emission spectra U. In order to demonstrate the success of the developed model, the emission spectra of dosimetric material LiF:Mg,Ti (TLD-100) was also measured. Then, a computerised best-fit program including the developed model was used to analyse the emission spectra. The …
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).
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 (