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Full-Text Articles in Physical Sciences and Mathematics

Diluted Magnetic Semiconductor: Structure, Size And Shape, And Magnetic Properties, Muhammet Arucu Jan 2017

Diluted Magnetic Semiconductor: Structure, Size And Shape, And Magnetic Properties, Muhammet Arucu

Turkish Journal of Physics

In dilute magnetic metallic alloys, spin exchange interactions among transition metal ions at the ZnO structure cause changes in the magnetic properties of the nanocrystals depending on size and shape. The effect of size and shape on the structural and magnetic properties of semiconductors, using atomistic spin calculations, is the main topic of this study. When the size of the system decreases to a few nanometers, stability is not observed as a result of the large size. We theoretically examine the magnetic properties of CoZnO materials according to size and shape effects using the Monte Carlo method and the Heisenberg …


Study Of The Energetic Field Characteristics Of The Te-Modalwaves In Waveguides, Fati̇h Erden Jan 2017

Study Of The Energetic Field Characteristics Of The Te-Modalwaves In Waveguides, Fati̇h Erden

Turkish Journal of Physics

The energetic characteristics of cylindrical medium-free time-domain waveguide fields are solved within the framework of the evolutionary approach to electromagnetics. Solving the boundary-eigenvalue problem for transverse Laplacian yields a configurational basis in the waveguide cross section. Elements of the basis depend on transverse coordinates, whereas the modal amplitudes depend on the longitudinal coordinate, $z,$ and time, $t$. Solving the resulted Klein-Gordon equation yields a basis for analysis of the modal amplitudes. Exact solutions for the amplitudes of TE-modes are obtained, and the energetic field characteristics are derived in accordance with the causality principle.


Triangular Quantum Profiles: Transmission Probability And Energy Spectrum, Altuğ Arda Jan 2017

Triangular Quantum Profiles: Transmission Probability And Energy Spectrum, Altuğ Arda

Turkish Journal of Physics

Analytical expressions for the transition probability and the energy spectrum of the 1D Schrödinger equation with position-dependent mass are presented for the triangular quantum barrier and quantum well. The transmission coefficient is obtained by using the wave functions written in terms of Airy's functions and of the solutions of Kummer's differential equation. In order to show the validity of our analysis, an example by taking some numerical values for a GaAs heterostructure is presented.


Determination Of Height Profile From A Two-Dimensional Fringe Signal Using A Two-Dimensional Continuous Wavelet Transform, Özlem Kocahan Yilmaz Jan 2017

Determination Of Height Profile From A Two-Dimensional Fringe Signal Using A Two-Dimensional Continuous Wavelet Transform, Özlem Kocahan Yilmaz

Turkish Journal of Physics

The main objective of this study was 3-dimensional (3D) profile measurements with standard fringe projection, consisting of a CCD and a projector. For obtaining height information of objects pixel by pixel, phases have to be calculated from the images taken by the fringe projection technique. In this study, the 2-dimensional continuous wavelet transform (2D CWT) phase method was used for phase extraction. 1D and 2D CWT analyses of noisy images were compared in simulations performed for a 2-dimensional fringe signal by introducing the carrier frequencies in two spatial directions, $x $ and $y$. Profile measurement of an object was made …


Investigation Of Low-Lying Magnetic Dipole Excitations In The $^{153}$Eu Nucleus, Emre Tabar Jan 2017

Investigation Of Low-Lying Magnetic Dipole Excitations In The $^{153}$Eu Nucleus, Emre Tabar

Turkish Journal of Physics

The properties of low-lying magnetic dipole ($M$1) excitations in $^{153}$Eu were studied within a rotational invariant quasiparticle phonon model that takes into account the symmetry-restoring as well as spin-spin residual forces. The calculations show that there are purely collective $M$1 excitations lying at 2-4 MeV fragmented over orbital 1$^{+}$ states of the $^{152}$Sm core nucleus. The results were compared to the experimentally known $M$1 excitations at 2-3 MeV. A reasonably good agreement in the total transition strength, the centroid energy, and the resonance width was obtained.


Promising Features Of In$_{0.5}$Ga$_{0.5}$N/Al$_{0.2}$Ga$_{0.8}$N Quantum Dot Lasers, Halima Bouchenafa, Badra Bouabdallah, Boucif Benichou Jan 2017

Promising Features Of In$_{0.5}$Ga$_{0.5}$N/Al$_{0.2}$Ga$_{0.8}$N Quantum Dot Lasers, Halima Bouchenafa, Badra Bouabdallah, Boucif Benichou

Turkish Journal of Physics

The group-III nitrides, InN, GaN, and AlN, and their alloys have emerged as one of the most important material classes for optoelectronic devices. The incorporation of quantum dots (QDs) as active material improves the performance of conventional optoelectronic devices, such as laser diodes. In this study, we present a theoretical analysis of the gain characteristics of In$_{x}$Ga$_{1-x}$N/Al$_{0.2}$Ga$_{0.8}$N three-dimensional quantum box lasers, based on the density matrix theory of semiconductor lasers with relaxation broadening. The study is done on three samples of QDs: GaN/Al$_{0.2}$Ga$_{0.8}$N, In$_{0.3}$Ga$_{0.7}$N/Al$_{0.2}$Ga$_{0.8}$N, and In$_{0.5}$Ga$_{0.5}$N/Al$_{0.2}$Ga$_{0.8}$N. A comparative study of the gain spectra of GaN/Al$_{0.2}$Ga$_{0.8}$N-based quantum-well and QD lasers is …


On The Contribution Of The 6.7 Kev Line Emission Of The Algol Binary System To The 6.7 Kev Line Emission From The Galactic Ridge, Ambrose Chukwudi Eze, Romanus Nwachukwu Chijioke Eze, Sudum Esaenwi Jan 2017

On The Contribution Of The 6.7 Kev Line Emission Of The Algol Binary System To The 6.7 Kev Line Emission From The Galactic Ridge, Ambrose Chukwudi Eze, Romanus Nwachukwu Chijioke Eze, Sudum Esaenwi

Turkish Journal of Physics

We carried out spectroscopic analysis of the extracted stellar flare of the Algol binary system observed using the Suzaku satellite (OBSID: 401093010), and resolved a strong 6.7 keV line emission. The 6.7 keV line emission of the Algol binary system is similar to the 6.7 keV line of the galactic ridge X-ray emission (GRXE). The equivalent width (EW) compared favorably with the EW of the 6.7 keV emission line obtained from different galactic ridge regions. In the galaxy, we have a reasonable number of Algol binary systems and many other stars as strong coronal X-ray emitters characterized by frequent quiescent …


The Milne Problem Using The P$_{N}$ Method For A Nonabsorbing Medium With Linearly Anisotropic Scattering, Mustafa Çeti̇n Güleçyüz, Ahmet Ersoy Jan 2017

The Milne Problem Using The P$_{N}$ Method For A Nonabsorbing Medium With Linearly Anisotropic Scattering, Mustafa Çeti̇n Güleçyüz, Ahmet Ersoy

Turkish Journal of Physics

The Milne problem, known as one of the classical problems of radiative transfer and neutron transport theory, is solved using the P$_{N}$ method for a nonabsorbing medium (c = 1) with a linearly anisotropic scattering kernel. Specular and diffuse reflection boundary conditions are taken into account. The numerical results are listed for different selected parameters. Some results are also compared with the literature.


Annealing And Deposition Time Effects On The Structural, Optical, And Electrical Properties Of Indium Sulfide Thin Films Produced By Chemical Bath Deposition Method, Emi̇ne Güneri̇, Fatma Göde Jan 2017

Annealing And Deposition Time Effects On The Structural, Optical, And Electrical Properties Of Indium Sulfide Thin Films Produced By Chemical Bath Deposition Method, Emi̇ne Güneri̇, Fatma Göde

Turkish Journal of Physics

Indium sulfide thin films were deposited onto indium-doped tin-oxide substrates with different deposition times (60 h, 63 h, 66 h, and 69 h) at room temperature by using a chemical bath deposition method to obtain new structures for solar cells. The film obtained at 60 h was annealed at 400 $^{\circ}$C for 1 h in nitrogen media. The crystallographic structure of the films was observed via the X-ray diffraction pattern while the size and shape of the grains were characterized by scanning electron microscopy. Moreover, the optical transmission spectra of the films were obtained at room temperature in the wavelength …


Lime: Semiautomated Line Measurement And Identification From Stellar Spectra, Ti̇mur Şahi̇n Jan 2017

Lime: Semiautomated Line Measurement And Identification From Stellar Spectra, Ti̇mur Şahi̇n

Turkish Journal of Physics

We present LIME (Line Measurements from ECHELLE Spectra), an IDL-based code, as a powerful tool for semiautomated stellar line measurement and identification. Interactively selected line positions (i.e. wavelengths) are compared with a master line list of the user's selections. Each unknown line that the user interactively chooses is displayed with potential identifications provided by the code in the vicinity of the selected line. The best identification is evaluated on the basis of several criteria (e.g., atomic/molecular line information, wavelength displacement, and theoretical equivalent width for solar atmospheric values). We examined the identifications by LIME in the spectra of post-red supergiant …


Influence Of Silicon Dioxide Medium On The Structural And Electrical Properties Of Nickel Zinc Ferrite, Jacob George, Abraham Kutticheril Eapen Jan 2017

Influence Of Silicon Dioxide Medium On The Structural And Electrical Properties Of Nickel Zinc Ferrite, Jacob George, Abraham Kutticheril Eapen

Turkish Journal of Physics

Nickel zinc ferrite [(Ni$_{0.65}$Zn$_{0.35}$Fe$_{2}$O$_{4}) _{x}$ / (SiO$_{2}) _{1-x}$ where, x = 1.0, 0.85, 0.65, 0.50, 0.35, and 0.15] is synthesized using the glyoxylate precursor method. The synthesis, characterization, and electrical study of nickel zinc ferrites/SiO$_{2}$ powder with low dielectric constant, very low conductivity, and loss tangent with low frequency dispersion, suitable for good insulators, is reported here. X-ray diffraction, TGA, and FT-IR studies are employed for identifying crystalline phases and structure. Crystallite size is calculated by the Scherrer formula and Williamson--Hall equation and found to fall in the range of 4.9--25 nm. TEM of the samples shows spherical particles of …


Second Law Of Gravitational Thermodynamics In The Locally Rotationally Symmetric Bianchi Type-Ii Universe, Murat Korunur Jan 2017

Second Law Of Gravitational Thermodynamics In The Locally Rotationally Symmetric Bianchi Type-Ii Universe, Murat Korunur

Turkish Journal of Physics

In this work, under the assumption that the universe is locally rotationally symmetric (LRS) Bianchi type-II and filled with anisotropic dark fluid (dark energy and dark radiation), we investigate whether the generalized second law of thermodynamics (GSLT) is still valid. We also consider another important condition for LRS Bianchi type-II spacetimes whereby the model expansion $\theta $ is proportional to the shear $\sigma $, which leads to $B=A^{n}$ (where n is a constant and A and B are the metric potentials). Based on this, we derive a general circumstance for the GSLT and find that its validity depends on the …


First-Principles Modeling Of Gan/Mose$_{2}$ Van Der Waals Heterobilayer, Celal Yelgel Jan 2017

First-Principles Modeling Of Gan/Mose$_{2}$ Van Der Waals Heterobilayer, Celal Yelgel

Turkish Journal of Physics

We investigate structural and electronic properties of the graphene-like gallium nitride (GaN) monolayer deposited on a MoSe$_{2}$ monolayer by using density functional theory with the inclusion of the nonlocal van der Waals correction. The GaN is bound weakly to the MoSe$_{2}$ monolayer with adsorption energy of 49 meV/atom. We find that the heterobilayer is energetically favorable with the interlayer distance of 3.302 {\AA} indicating van der Waals (vdW) type interaction and the most stable stacking configuration is verified with different deposition sequences. The heterostructure of GaN/MoSe$_{2}$ is found to be indirect band gap semiconductor with gap value of 1.371 eV. …


Magnetized Strange Quark Matter In Reconstructed $F(R,T)$ Gravity For Bianchi I And V Universes With Cosmological Constant, Can Aktaş Jan 2017

Magnetized Strange Quark Matter In Reconstructed $F(R,T)$ Gravity For Bianchi I And V Universes With Cosmological Constant, Can Aktaş

Turkish Journal of Physics

In this article, we have investigated the behaviors of magnetized strange quark matter distributions for Bianchi I and V universes in reconstructed $f?eft( R,T \right)=\alpha_{1}R+\alpha_{2}f_{3}(T)$ gravity (here $\alpha_{1}$ and $\alpha_{2}$ are constants; $f_{3}(T)$ is an arbitrary function of $T)$. To get solutions of the field equations we have used a deceleration parameter and the equation of state for strange quark matter. The new represented $f(R,T)$ model includes two models of Harko et al. and transforms to general relativity. When $t\to ınfty $, we get the dark energy model ($p=-\rho )$ in reconstructed $f?eft( R,T \right)=\alpha _{1}R+\alpha_{2}f_{3}(T)$ gravity. However, we obtain …


Monte Carlo Simulation Of A Medical Linear Accelerator For Filtered And Fff Systems, Çağri Yazğan, Yi̇ği̇t Çeçen Jan 2017

Monte Carlo Simulation Of A Medical Linear Accelerator For Filtered And Fff Systems, Çağri Yazğan, Yi̇ği̇t Çeçen

Turkish Journal of Physics

In order to simulate radiation transport, various algorithms, codes, and programs have been developed. In this study Monte Carlo N-particle code is used to simulate a medical electron linear accelerator gantry for research purposes. Detailed geometry of the LINAC head and water phantom are modeled and simulated for calculations. Analyses are made for filtered and flattening filter-free (FFF) systems. Percent depth dose and dose profile measurements are calculated with Monte Carlo simulations and compared with experimental and theoretical values for quality assurance of the model. Flux, dose, and spectrum analyses are performed for filtered and FFF systems separately. In this …


Analytical Solution Of The Local Fractional Klein-Gordon Equation For Generalized Hulthen Potential, Hasi̇be Hale Karayer, Ahmet Doğan Demi̇rhan, Fevzi̇ Büyükkiliç Jan 2017

Analytical Solution Of The Local Fractional Klein-Gordon Equation For Generalized Hulthen Potential, Hasi̇be Hale Karayer, Ahmet Doğan Demi̇rhan, Fevzi̇ Büyükkiliç

Turkish Journal of Physics

The one-dimensional Klein-Gordon (KG) equation is investigated in the domain of conformable fractional calculus for one-dimensional scalar potential, namely generalized Hulthen potential. The conformable fractional calculus is based on conformable fractional derivative, which is the most natural definition in noninteger order calculus. Fractional order differential equations can be solved analytically by means of this derivative operator. We obtained exact eigenvalue and eigenfunction solutions of the local fractional KG equation and investigated the evolution of relativistic effects in correspondence with the fractional order.


Applying A Self-Feedback Method To Control Chaos In The Buck Converter, Mei Mei Jia Jan 2017

Applying A Self-Feedback Method To Control Chaos In The Buck Converter, Mei Mei Jia

Turkish Journal of Physics

Chaos exists in the Buck converter due to the switching action of the controlled switch and this nonlinear phenomenon results in unreliable working performances. Hence, this paper uses a self-feedback control method with two adjustable parameters to suppress the chaotic behavior in the Buck converter. First, the self-feedback control method is presented by introducing a generic second-order chaotic system. Then, from the perspective of transfer functions obtained in terms of the piecewise linear model of the controlled Buck converter, effects of controller's parameters on system performances are discussed. On the basis of the Jacobian matrix of the discrete iterative mapping …


Spin (Pseudospin) Doublet In View Of Energy-Dependent Potential, Mustafa Salti, Oktay Aydoğdu Jan 2017

Spin (Pseudospin) Doublet In View Of Energy-Dependent Potential, Mustafa Salti, Oktay Aydoğdu

Turkish Journal of Physics

Behavior of Dirac particles in the presence of scalar, vector, and tensor potentials respectively represented by energy-dependent Morse and Coulomb-like potentials is examined by working out the Dirac equation under the condition of spin (pseudospin) symmetry. The closed form of the energy eigenvalue equation and corresponding wave functions in terms of hypergeometric functions are acquired by making use of the asymptotic iteration method. We investigate the effect of energy-dependent potential on both bound states and energy splitting between members of spin (pseudospin) doublets.


Monitoring Akkuyu Nuclear Reactor Using Antineutrino Flux Measurement, Sertaç Öztürk, Aytül Adigüzel, Veysi̇ Erkcan Özcan, Nafi̇z Gökhan Ünel Jan 2017

Monitoring Akkuyu Nuclear Reactor Using Antineutrino Flux Measurement, Sertaç Öztürk, Aytül Adigüzel, Veysi̇ Erkcan Özcan, Nafi̇z Gökhan Ünel

Turkish Journal of Physics

We present a simulation-based study for monitoring Akkuyu nuclear power plant's activity using antineutrino flux originating from the reactor core. A gadolinium-doped water Cherenkov detector was designed and optimization studies were performed using the Geant4 simulation toolkit. It was found that the bottom (or top) face of the target should be instrumented by six 10-inch-diameter photomultiplier tubes with photon detection efficiency of about 35% and the optimum Gd concentration was found to be about 0.3%-0.5%. The first study on the design of a monitoring detector facility for Akkuyu nuclear power plant is discussed in this paper.


Investigating The Instability Of The Torus Around The Blackhole In The Presence Of The Radial And Angular Velocity Perturbations, Orhan Dönmez Jan 2017

Investigating The Instability Of The Torus Around The Blackhole In The Presence Of The Radial And Angular Velocity Perturbations, Orhan Dönmez

Turkish Journal of Physics

We have performed the numerical simulation of the perturbed relativistic torus around the black hole by solving the general relativistic hydrodynamics equations on the equatorial plane. We have monitored the different simple models by applying the radial and angular velocity perturbations to the steady state torus around the black hole. The instabilities are triggered by adding the subsonic velocity fields over the radial and angular velocities of the stable torus. We have found the disk instability so-called the Papaloizou-Pringle instability and excited modes of the Quasi-Periodic Oscillations (QPOs) in the thin disk approximation case. The significant oscillations and oscillation modes …


The Effect Of Sintering In Different Atmospheres On Superconductivity Parameters Of Ybco, Mehmet Başoğlu Jan 2017

The Effect Of Sintering In Different Atmospheres On Superconductivity Parameters Of Ybco, Mehmet Başoğlu

Turkish Journal of Physics

YBa$_{2}$Cu$_{3}$O$_{7}$ (Y123) is a superconductor material discovered in 1987 and its transition temperature is above the liquid nitrogen temperature. It is known that superconductor samples produced by the solid-state reaction route are very often sintered in air atmosphere. However, in the presented work, Y123 was prepared by the same technique using a sintering ambient composed of a mixture of oxygen and argon gases for the first time. Critical current densities of the samples were calculated using results of magnetization measurements. It was obtained from magnetization analysis that all the samples exhibited superconductor character. It was also observed that the sample …


Higher-Dimensional Dust Collapse In F(R) Gravity, Zahid Ahmad, Muhammad Shoaib Khan Jan 2017

Higher-Dimensional Dust Collapse In F(R) Gravity, Zahid Ahmad, Muhammad Shoaib Khan

Turkish Journal of Physics

The $n+2$-dimensional gravitational collapse of pressureless fluid is investigated in metric $f(R)$ gravity. Matching conditions are derived by taking the $n+2$-dimensional Friedmann-Robertson-Walker (FRW) metric as interior spacetime and the $n+2$-dimensional Schwarzschild metric as exterior spacetime. In the analysis of the solution of field equations, the scalar curvature is assumed to be a constant. It is observed that the scalar curvature constant term $f(R_{0})$ slows the collapse.


Comparison Of Structural Properties Of Some Liquid Crystals, Emi̇ne Mi̇ne Çapar Jan 2017

Comparison Of Structural Properties Of Some Liquid Crystals, Emi̇ne Mi̇ne Çapar

Turkish Journal of Physics

Molecular dynamics simulations were performed for three liquid crystalline molecules, 4-cyano-4$'$-octyloxybip- henyl (8OCB), n-p-cyanobenzylidene-p-octyloxyaniline (CBOOA), and p-n-hexyloxybenzylidene-p$'$-aminobenzonitrile (HBAB). Simulation data were obtained for three liquid crystals in the nematic and isotropic phases to analyze their structural properties. The imine spacer group in the Schiff bases induces a stepped core structure in which the linearity is maintained. The distributions of the angles between some defined vectors imply that the core segments of CBOOA and HBAB are more floppy than the 8OCB core. The biaxialities, molecular dimensions, and molecular anisotropies were calculated. The results were compared for three mesogens in the nematic …


Role Of Mg Doping In The Structural, Optical, And Electrical Characteristics Of Zno-Based Dsscs, İsmai̇l Polat, Sali̇h Yilmaz, Murat Tomaki̇n, Emi̇n Bacaksiz Jan 2017

Role Of Mg Doping In The Structural, Optical, And Electrical Characteristics Of Zno-Based Dsscs, İsmai̇l Polat, Sali̇h Yilmaz, Murat Tomaki̇n, Emi̇n Bacaksiz

Turkish Journal of Physics

ZnO- and Mg-doped ZnO samples are prepared by spray pyrolysis on conducting glass substrates to fabricate ZnO-based dye-sensitized solar cells (DSSCs). Influences of Mg-doping content on the power conversion efficiencies of ZnO-based DSSCs are investigated. X-ray diffraction results show that all the samples exhibit a hexagonal wurtzite structure. Scanning electron microscopy data indicate that the ZnO sample has uniform rods with 1 $\mu $m diameter. With respect to ZnO, the band gap value of 4 at.% Mg-doped ZnO samples improves to the value of 3.27 eV and a further increase in Mg level up to 6 at.% gives rise to …


Design Of Turkish Accelerator And Radiation Laboratory In Ankara (Tarla) Facility Injector Magnets, Avni̇ Aksoy Jan 2017

Design Of Turkish Accelerator And Radiation Laboratory In Ankara (Tarla) Facility Injector Magnets, Avni̇ Aksoy

Turkish Journal of Physics

The installation of a high current thermionic gun-based injector capable to accelerate a maximum 1.5 mA electron beam at 250 keV and continuous wave (CW) for various bunch repetition rates has been continuing at the Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) since 2014. The injector, which is based on totally normal conducting technology, will mainly consist of a thermionic DC electron gun, two stage bunch compressor cavities operating at 260 MHz and 1.3 GHz, one dipole magnet, five solenoid lenses and an additional one dipole magnet that is going to be used as spectrometer, and several steerer magnets. …


Field-Free Molecular Alignment Control Of Filamentation, Necati̇ Kaya Jan 2017

Field-Free Molecular Alignment Control Of Filamentation, Necati̇ Kaya

Turkish Journal of Physics

With an approach of controlling the nonlinearity of medium rather than the light field, the effect of field-free molecular alignment on filamentation and resulting white-light generation is studied. This is done by measuring the rotational wavepacket evolution of nitrogen molecules after passing of a femtosecond laser pump pulse by observing the nonlinear propagation dynamics of a variably delayed filament-producing probe pulse.


Bound States Of The Duffin-Kemmer-Petiau Equation For Square Potential Well With Position-Dependent Mass, Zoulikha Hammoud, Lyazid Chetouani Jan 2017

Bound States Of The Duffin-Kemmer-Petiau Equation For Square Potential Well With Position-Dependent Mass, Zoulikha Hammoud, Lyazid Chetouani

Turkish Journal of Physics

The effective mass Duffin-Kemmer-Petiau equation for spin 0 and spin 1 with a potential well is considered, and transcendental equations are derived for the energy eigenvalues. Numerical results are reported graphically, and the variations of the energy of the bound states are computed as a function of the well width and mass.


Phenomenological Potential Calculations For Cluster Decays, Asim Soylu Jan 2017

Phenomenological Potential Calculations For Cluster Decays, Asim Soylu

Turkish Journal of Physics

The half-lives of cluster decays from various nuclei having experimentally measured values have been calculated by using the Wentzel-Kramers-Brillouin method together with the Bohr-Sommerfeld quantization condition for three different types of phenomenological nuclear interactions: Woods-Saxon (WS), squared Woods-Saxon (WS-2), and mixed Woods-Saxon (mWS) potentials. By comparing the results with experimental values, rms values have been calculated. The half-lives of $^{14}$C, $^{15}$N, $^{16}$O, $^{17}$O, $^{18}$O, $^{20}$O, $^{22}$O, $^{23}$F, $^{22}$Ne, $^{24}$Ne, $^{25}$Ne, $^{26}$Ne, $^{28}$Mg, $^{30}$Mg, and $^{34}$Si decays from various isotopes whose experimental half-lives are unknown have also been calculated by using the WS, WS-2, and mWS potentials. The obtained results have …


Search Of Islands Of Stability For Hypothetical Superheavy Nuclei Using Covariant Density Functional Theory, Hazem Abusara, Shakeb Ahmad Jan 2017

Search Of Islands Of Stability For Hypothetical Superheavy Nuclei Using Covariant Density Functional Theory, Hazem Abusara, Shakeb Ahmad

Turkish Journal of Physics

A systematic search for the location of islands of stability has been performed for the proton number $100\le Z\le 220$ and the neutron number $Z+30\le N\le 2Z+30$ using covariant density functional theory (CDFT), a relativistic Hartree-Bogoliubov (RHB) formalism with separable pairing, for two different force parameters, DD-ME2 and NL3*. Locations of the islands of stability are identified by analysis of the two-neutron and two-proton separation energy, two-nucleon shell gaps, vanishing neutron and proton pairing gap, energy surface, and the single particle states. The results show that beyond $^{292}120$ only Z = 154 and N $>$ 220 can be a …


Linear Instability Of Dust Acoustic Waves In A Magnetized Gravitating Plasma In The Presence Of Dust Streaming, Himangshu Sahoo, Basudev Ghosh, Kalyan Kumar Mondal Jan 2017

Linear Instability Of Dust Acoustic Waves In A Magnetized Gravitating Plasma In The Presence Of Dust Streaming, Himangshu Sahoo, Basudev Ghosh, Kalyan Kumar Mondal

Turkish Journal of Physics

Linear instability of dust acoustic waves (DAWs) has been theoretically studied in a collisionless gravitating dust-ion magnetized plasma including the effect of dust streaming. A linear dispersion relation has been derived by using the method of normal mode analysis. Gravitational effect is found to make the low-frequency DAW mode linearly unstable in certain parametric regions. The dependence of the growth rate of the instability on various plasma parameters such as streaming of dust particles, size of the dust grain, strength of the magnetic field, obliqueness of propagation, and number density of dust particles has been numerically analyzed and presented graphically.