The aim of this study was to investigate the effect of non- stability surface of support leg on the instep kicking kinematics in soccer players.
30 male soccer players participated in this study. After the measurement of static and dynamic balance tests by the Biodex System, 20 players were selected who were at a desired level of the balance. Data were recorded using the three- dimensional motion analysis system with 6 optoelectronic cameras (200 HZ). The kinematic parameters in three critical moments of kicking (Forward swing of hip, Contact to ball, Follow through) were compared by using repeated measures of variance and independent t- test (0/05).
The results showed that the values of maximum angular velocity and displacement of hip and velocity of ball at the kicking over stability surface was significantly higher from the kicking over non- stability surface.
These results indicate that the kicking over non- stability surface causes the lower of kinematic parameters in the more of the kicking skill phases and the movement prime velocity of ball.

Vertical and uniform zinc oxide (ZnO) nanorods were grown on seeded silicon substrate using chemical bath deposition (CBD) technique. A ZnO thin film was sputtered on Si substrate to be used as a seed layer. The effects of growth temperature and time on morphology and structural properties of ZnO nanorods were investigated using scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The results showed that ZnO seed layer acts an important role for uniformity of synthesized nanorods. Furthermore, uniform and vertical nanorods can be grown on silicon substrates by optimization of growth parameters. The ZnO nanorods which were grown using this technique can show improved structural properties without post-deposition thermal treatments. Due to the compatibility of silicon with electronic devices, ZnO nanostructures based on seeded silicon can be widely used in optoelectronic industries.

Nitrogen-doped graphene oxide N-GO nanocomposite synthesized by a hydrothermal method in which urea used as a reduction agent. The reduction of graphene oxide confirmed by the x-ray diffraction, scanning electron microscopy, fourier transform infrared and UV-VIS spectroscopy analyzes. The measurement of the distance between the sheets and energy band gap of the N-GO nanocomposite indicated an increasing in interspaces of sheets and a slight broadening in energy band gap due to adding of nitrogen. For the first time, the optical susceptibility of N-GO nanocomposite calculated via Z-scan technique and confirmed the third-order optical nonlinearity. The nonlinear optical susceptibility calculated in the order of 10-9 esu that shows the high efficiency of this nanocomposite for using in optoelectronic devices.

The increasing attention of researchers to reduce the thickness of two-dimensional nanostructures, is due to their unique physical, chemical, mechanical, and optical properties, which is based on their two-dimensional morphology and ultrathin thickness. In this research, the aim is introduce and express the applications of ultrathin two-dimensional nanomaterial. Ultrathin two-dimensional nanomaterial are more important than other nanomaterial due to a number of their unique properties. In fact, these characteristics have attracted interest in using them in the fields of the electronics/optoelectronics, catalysis, energy storage and conversion, water remediation, sensors and biomedicine. Recently, using them are increasing in extraction and removal of materials from aqueous media and complex matrices.

In the present study, we introduce a concept to generate the spin-polarized current in armchair transition metal dichalcogenide nanoribbons (TMDNs) by  using light irradiation. For simulating the opto-spin current, we use electron-photon interaction in non-equilibrium Green's function methods. Because of the intrinsic spin-orbit coupling, light irradiation produces spin-photocurrent in TMDNs without applying any external magnetic element. Moreover, transverse electric field modifies the magnitude and position of optical absorption peaks, as well as the magnitude of the spin-photocurrent. Finally, the fully spin-polarized photocurrent, the high quantum efficiency with a maximum of approximately 50%, the wide-wavelength-range operation from ultraviolet to infrared and optical spin-filtering effects are tunable with transverse electric field indicate the high performance of this spin-photodetector based on armchair TMDNs, thereby paving the way  toward the improved design and performance of this photodetector in spin-optoelectronics.

potential candidate for using in spintronic and optoelectronic devices. Using first principle calculations based on density functional theory within generalized gradient approximation (GGA), we studied the elastic,mechanical, electronic, magnetic and optical properties of NbBiCs half-Heusler alloy in bulk state. Spin polarization at Fermi level is 97.6% and 100% whitin GGA and GGA+mBJ, respectively. The real part of the dielectric function for half-Heusler alloy NbBiCs in α phase for energies greater than 20eV converge to one, indicating that it act as an isotropic insulator and also the refractive index for energies greater than 7.5 eV is less than one, indicating super-liminance.

In this paper, two-dimensional organic-inorganic hybrid structures with the general formulas of (BA)2PbI4 and (PEA)2PbI4 as the luminescent materials are experimentally investigated. The luminosity properties of the these organic-inorganic hybrid structures are also examined in the absence and presence of coating with thin layers of gold and platinum of 20 nm in thickness at different temperatures ranging from the room temperature to about 106 K under excitation by a light source with the wavelength of approximately 400 nm. According to the observations, illumination in the case of the (BA)2PbI4 structure at 120 K can be enhanced by 12.9 times the illumination at room temperature. In addition, illumination in the case of the (PEA)2PbI4 structure coated with a 20 nm thick platinum layer at 173 K can be enhanced 12.2 times the illumination at room temperature. These results suggest that two-dimensional organic-inorganic hybrid structures (especially (BA)2PbI4 and (PEA)2PbI4 structures) can be useful for the design of novel electronics and optoelectronics devices.

Due to the unique physical and chemical properties of two-dimensional (2D) materials, such as linear band structure near the Fermi level, high electrical and thermal conductivity, they have opened up a wide vision in the fabrication of nanoelectronic devices, energy storage and information transmission. One of the theses materials that has recently received attention is a two-dimensional monolayer of boron atoms called borophene which has various allotropes such as α, β12, χ3, 2-pmmn and 8-pmmn. This 2D material has tilted and anisotropic Dirac cone and in addition to excellent transparency, it has excellent electron and ion conductivity. These properties along with other properties of borophene have caused diverse and potential applications of this material in gas sensors, metal ion batteries and electronic and optoelectronic devices. In this paper, we intend to review the properties of borophene and investigate the effect of factors such as impurity, light radiation, strain, dimension reduction in the form of nanoribbon, temperature, electric and magnetic fields on the properties of electron transport in this material.

Nitrate compounds III-N with a wide band gap have an important role in the field of optoelectronics and electronic devices with high frequency and power. Gallium nitride (GaN) has emerged as one of the most important and widely used semiconducting material among them. In this article, the electron mobility in one dimensional nanoribbon gallium nitride in the presence of impurities has been investigated and we compare our results with electron mobility of two dimensional systems. The Boltzmann transport equation and relaxation time approximation with considering the ionized impurity potential are used in calculations. The influence of different relevant physical parameters such as width of nanoribbon strips, Fermi energy and impurity density on the mobility is examined. Finally the electron mobility as a function of Fermi energy, distance between impurity with carriers and width of nanoribbons for gallium nitride is plotted. As it is expected, numerical results show that the mobility of GaN nanoribbon for very large width move toward mobility in two dimensional electron gas.