JOURNAL OF RESEARCH ON MANY BODY SYSTEMS
Year:2017 | Volume:7 | Issue:14 |Papers Count:10

The present study investigated nuclear fusion of 48Ca ions with 248Cm nuclei for synthesizing the super heavy nuclei 296Lv located in the island of stability. We estimate the fusion barrier against 48Ca and 248Cm nuclei in the framework of the theoretical calculations and investigate the influence of the direction of target nuclei on the parameters of the fusion barrier. Furthermore, we show that the minimum energy for synthesizing 296Lv is equal to 205. 17 MeV which is relevant to the collision between the projectile and target nuclei under orientations( ).   0  0 Finally, in the framework of the statistical model we estimate the evaporation residue cross-section for 293Lv and 292Lv nuclei after emission of three and four neutrons from 296Lv nuclei and we show that the results are in good agreement with the experimental data.

In this article, we consider rectangular superconducting small grains for hole-doped cuprates near diagonal zone. Since important models for high temperature superconductivity contain the exchange of spin fluctuations, we want to apply one of the famous modelscalled spin-fermion. Based on this model, we want to obtain the total polarization (without considering self-energy and using standard Eliashberg equations) and first order correction of polarization (using perturbed linearized equation and normal and anomalous first order Green's function) in terms of finite size and disorder effects, numerically. It's worth mentioning that the first order perturbed polarization is expanded in terms of size-dependent gap and this polarization itself depends on disorder. Finally, competition between two effects is investigated and it is observed that the finite size effect is more dominant with respect to the disorder effect.

In this study, we investigate the electromagnetic wave absorption of Hard-Soft ferrite nanocomposites in the frequency range of 1-18 GHz. These composites consist of two different magnetic phases with different weight ratios. The hard magnetic phase consists of Strontium Hexaferrite (SF) and the soft magnetic phase consists of Cobalt Zinc Ferrite (CZF). XRD analysis of the samples indicate formation of pure phase for each magnetic phases. Investigation of the real and imaginary parts of complex permittivity and permeability of samples indicate the response of electromagnetic waves to these samples in the frequency range of 1-18 GHz. The reflection loss versus frequency shows this absorbing behavior in the samples.

In this investigation calculated cross section of induced photo-fission of uranium Isotopes, 230-239U using simulation through optical model are compared with experimental data. To obtain photo-fission cross section transition probability through three humps fission barrier is used. Also, in order to calculate level density of compound nucleus, improved version of Enhanced Generalized Super-fluid Model (EGSM) is employed. Simulated cross sections using Empire code for these Isotopes in a wide range of energy are compared with available experimental data. Cross sections for different isotopes of uranium are plotted as a function of energy in the range 5 to 20 MeV. Good agreement achieved when the results of Empire code are compared with available experimental data.

The Isomeric Yield Ratio (IYR) of 115m, gCd in the 40, 45, 50, 55, 60, 65, 70 and 75 MeV bremsstrahlung induced reaction of natCd has been determined for the first time by off-line gamma ray spectrometric technique using 100 MeV electron linac at Pohang Accelerator Laboratory (PAL), Pohang, Korea. The IYR of 115m, gCd as a function of bremsstrahlung energy was also calculated theoretically using computer code TALYS 1. 6. The experimental IYR in the 116Cd(γ , n)115m, gCd reaction obtained in the present work along with literature data at lower energies are compared with the theoretical value from TALYS and found to be in general agreement. It was observed that the experimental and theoretical IYR of 115m, gCd increases with the increase of end-point bremsstrahlung energy, which shows the effect of excitation energy. It was also seen that the IYR of 115m, gCd increases sharply from the reaction threshold value to endpoint bremsstrahlung energy of 18 MeV and thereafter increase slowly. This indicates the role of Giant Dipole Resonance (GDR) besides the effect of excitation energy.

We study quantum nature of metamaterials in the presence of electromagnetic field. Starting from a Lagrangian, the electromagnetic field is canonically quantized in the presence of eht metamaterials. The equations of motion for the canonical variables are solved using Laplace technique. In the large-time limit, the vector potential operator is found and expressed in terms of the medium operators. In a global thermal state, finite temperature two-point correlation functions of the electromagnetic field are calculated. The electromagnetic energy flux and energy density and absorbed energy in metamaterials are obtained by considering the special case of thermal equilibrium and using Noether's theorem.

The electronic properties of thin films and nanostructures as well as the surface electronic structure can be obtained using reflection electron energy loss technique at low energy. In this study, dielectric function of SrTiO3 is obtained by Yubero-Tougaard method using the experimental inelastic cross section obtained by Tougaard-Chorkrndorf method. Theoretical cross section obtained at energy 1423 eV, incidence angle 15° and exit angle 35° was found to be in good consistency with experimental cross section. In addition, the angular distribution of the surface excitation parameter for this crystal was determined at energies 1000, 1423, 2000, 2500 and 3000 eV. To this end, the definition presented by Pauly and Tougaard was used which relies on the variation in excitation probability at surface and moving in semi-infinite medium. This parameter was calculated based on the differential inelastic electron dispersion cross section using QUEELS software, which is valid for reflection electron energy loss spectrum.

In this paper, entropy and specific heat of a GaAs quantum wire with two different cross sections is studied. First, using the solution of Schrodinger equation, the eigenvalues and eigenfunctions are calculated analytically. Then, we have obtained entropy and specific heat of two quantum wires using Tsallis formalism. The results show that entropy and specific heat are continnus functions. Unlike classical thermodynamics, entropy and specific heat will not have any value and by a condition (cut off) is determined. For both wire, with increasing wire size the peak numbers in specific heat are changed. The stronger the quantum confinement, the thermodynamic properties of the discrete nature becomes more apparent.

In this article, we investigate the spin transport properties of a superlattice silicene nanoribbon connected to two semi-infinite metallic leads, in the tight-binding model and Green's function approach, and in the presence of disorder and electric and exchange fields. Our calculations show that the metal-semiconductor phase transition occurs, when a perpendicular electric field and/or disorder is applied to the system. Also by changing the steplike electric field, the width of the energy gap will be controlled. In addition, by applying the disorder such as vacancy and impurity, the conductance of the system decreases and its band gap increases. Namely, the band gap of the system can be tuned by varying the relevant parameters, such as disorder concentration, steplike electric field and exchange field strength.

In this investigation, fabrication and investigation on structural and optical properties, the layer growth and quantum efficiency of CdS/ CdTe bi-layer structure on ITO substrate for the production of cadmium telluride-base solar cells are dealt with. The mentioned bi-layer was made by using physical vapor deposition (PVD) method. In order to find the crystal structure of the individual layers or observation of new phase formed at their interface, X-ray diffraction analysis was used. With the help of this analysis, CdTe1-xSx ternary phase was observed at 2Ө =89. 95° which has been attributed to the inter diffusion of the two layers. Optical studies show the change in optical transmission compared to the pure cadmium telluride. The surface uniformity and thickness of the specimens and morphology of the grown columns were investigated by FESEM analysis. The FESEM images showed that the layers growth was in uniform columnar form. Quantum efficiency showed that during photovoltaic phenomenon, all photons with a wavelength of 800 nm can produce either an electron. I-V plot study of the prepared bi-layer structure shows a cell efficiency of 1. 4 percent and fill factor of 0. 65.