فائز صالح عباس -

In this paper, we present a calculation method for evaluating the possibility of enhancing the thermal stability of nickel silicide by alloying with metals, which consists in determining the formation enthalpy (ΔH) of nickel silicide using the Miedema model. Changes in formation enthalpy (ΔH) were observed for nickel silicides that were alloyed with Mo, Pt, Pd, W, and Zr. The MAAT (Materials Analysis Applying Thermodynamics) software was used to calculate and plot the formation enthalpy of binary and ternary systems. Based on our calculations, we found that in binary systems, the optimum values to expand the formation enthalpy were 51.28 and 49.57 kJ/mol for nickel silicide alloys. For the ternary system, the results showed that adding Zr could increase monosilicide phase stability

The five conjugated D–π–A systems are theoretically analyses by applying the Density Functional Theory (DFT) and Time– Dependent Density Functional Theory (TDDFT) /6–311G (d, p)/B3LYP methodology for the ground and the exaction state at the gas phase. The Gaussian 09 software package was utilized to complete the computations with Gauss View 5.0. The various electron side groups were added as donor–moieties in D–π–A formation to discover highly efficient dyes for Dye- Sensitized Solar Cells (DCCs) applications. The structural, electronic, optoelectronic, photovoltaic, absorption, electronic excitation, dipole moment, regeneration, and electron injection characteristics of all designed systems have been reported. The results showed that the designed dyes have efficient properties such as: good delocalization of HOMO, LUMO with energy gab, effective electron injection, performance charge transfer, subsequent regeneration, large LHE, conversion efficiency, direction transition and strong photo sensitizing. Therefore, these results demonstration that the new D–π–A structures can be considered as a new candidate dye-sensitized for applications in organic solar cells.

The Miedema semi-empirical model is suitable for estimating the thermodynamic parameters of solid solution and amorphous binary and ternary Fe-Al-Ni systems. A novel software, MAAT (materials Analysis Applying Thermodynamics), was utilized to calculate the thermodynamic characteristics of both binary and ternary systems. The results demonstrated that the values of the Gibbs free energy of the binary systems of the solid solution of Fe-Al, Fe-Ni, and Al-Ni, and amorphous phases Fe-Al and Al-Ni were negative, while for the amorphous Ni-Fe was positive. For the ternary system, the Gibbs free energy was seen to be negative in the entire composition range. The ΔGss is more damaging than the ΔGam. They suggested driving forces to reach to the solid solution and amorphous phase from the pure Fe, Al, and Ni powders in the entire composition extent.

Abstract.In this work, new organic donor-π-acceptor molecules based on thienopyrazine is designed and reported. Diverse side based electron groups were presented to evaluate their impacts on the electronic and photovoltaic properties. The calculations of ground state were done by employing the DFT-B3LYP/6-31G(d,p) and the TD-DFT method for the excitation properties of the produced molecules. The results indicated that the “HOMO” and “LUMO” level are slightly changed and this suggests that there are different structures, playing important roles in improving the electronic and photovoltaic properties and in improving the electron accepting ability. The attained values of band gap together with the open circuit voltage are parameters that can be manipulated to improve the quality of solar cell applications. Moreover, the results showed that these molecules can be used for a solar cell as organic sensitizers due to probability of the electron injection process from the molecules to the conduction band of PC60BM, PC70BM or TiO2, in addition to the help of the compounds in designing more effective functional photovoltaic organic materials

A B S T R A C T In this article, the relativistic nonlinear self-focusing of a right circular polarized laser beam propagated through magnetized plasma was investigated. The high power of laser beam which resulted from the self-focusing effect was exploited to excite an electromagnetic wave to the terahertz frequency range. By controlling the external longitudinal magnetic field, a high stabilized terahertz field was observed. At terahertz frequency (1THz) where the initial laser beam radius (x0 = 20 μm) and initial laser beam intensity (I0 = 10 W/cm ) 17 2 , the highe

Abstract Background: In this work, solar cell sample was exposed to a 137Cs gamma ray source. The voltage - current characteristics of a mono-crystalline silicon solar cell were investigated before and after the irradiation with gamma source. Materials and methods: commercially silicon solar cells, solar module analyzer 6A V110906, reflective lamp, gamma ray source. We obtain voltage - current (I-V) characteristics and output parameters of solar cell before and after irradiation were measured. solar cell were illuminated by reflective lamp. The measurements were performed at room temperature with highly accurate measuring equipment. Results: The resulted data demonstrated basic solar cell parameters which include , , & has clearly changed when the gamma ray exposure increased from 0 - 4 days. Magnitudes of the parameters ( , , & ) inversely proportional with -ray exposure. This would indicate that high gamma ray exposure would induce certain defects. A decline in the silicon solar cell parameters after gamma irradiation was seen; this is strongly supported by marked decrease in the minority carriers lifetime as exposure time to radiation increases. Conclusion: Obtained results could lead to new designs of silicon solar to increasing their applications in radiation environments.