A simple spraying technique was employed to deposit nickel hydroxide films on glass substrates. Nickel oxide films with different crystallite size were obtained by post annealing of Ni(OH)2 films in air at 523–673 K. The structure, chemical composition, surface morphology and thickness of the as-deposited and annealed films were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallite size was found to increase with increasing the annealing temperature. SEM revealed rather homogeneous films with an average thickness of about 10 m. Optical absorption study in 200 - 900 nm wavelength range reveals high absorption for wavelengths (λ) less than 400 nm in the ultraviolet (UV) and visible range. The UV absorption edge of NiO nanostructured films show shorter wavelength-shift that increases with increasing the crystallite size. NiO films exhibit optical transition by both direct and indirect allowed transitions. Direct and indirect optical energy gaps were calculated and found to decrease from 3.25 to 2.87 eV and 3.84 to 3.62 eV respectively; while the width of the localized states increases from 0.306 to 0.586 eV with decreasing the crystallite size from 23.4 to 5.7 nm. Dispersion spectra, real and imaginary parts of the dielectric constant spectra are examined at high frequencies.

A simple spraying technique was employed to deposit nickel hydroxide films on glass substrates. Nickel oxide films with different crystallite size were obtained by post annealing of Ni(OH)2 films in air at 523–673 K. The structure, chemical composition, surface morphology and thickness of the as-deposited and annealed films were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallite size was found to increase with increasing the annealing temperature. SEM revealed rather homogeneous films with an average thickness of about 10 m. Optical absorption study in 200 - 900 nm wavelength range reveals high absorption for wavelengths (λ) less than 400 nm in the ultraviolet (UV) and visible range. The UV absorption edge of NiO nanostructured films show shorter wavelength-shift that increases with increasing the crystallite size. NiO films exhibit optical transition by both direct and indirect allowed transitions. Direct and indirect optical energy gaps were calculated and found to decrease from 3.25 to 2.87 eV and 3.84 to 3.62 eV respectively; while the width of the localized states increases from 0.306 to 0.586 eV with decreasing the crystallite size from 23.4 to 5.7 nm. Dispersion spectra, real and imaginary parts of the dielectric constant spectra are examined at high frequencies.

A simple spraying technique was employed to deposit nickel hydroxide films on glass substrates. Nickel oxide films with different crystallite size were obtained by post annealing of Ni(OH)2 films in air at 523–673 K. The structure, chemical composition, surface morphology and thickness of the as-deposited and annealed films were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallite size was found to increase with increasing the annealing temperature. SEM revealed rather homogeneous films with an average thickness of about 10 m. Optical absorption study in 200 - 900 nm wavelength range reveals high absorption for wavelengths (λ) less than 400 nm in the ultraviolet (UV) and visible range. The UV absorption edge of NiO nanostructured films show shorter wavelength-shift that increases with increasing the crystallite size. NiO films exhibit optical transition by both direct and indirect allowed transitions. Direct and indirect optical energy gaps were calculated and found to decrease from 3.25 to 2.87 eV and 3.84 to 3.62 eV respectively; while the width of the localized states increases from 0.306 to 0.586 eV with decreasing the crystallite size from 23.4 to 5.7 nm. Dispersion spectra, real and imaginary parts of the dielectric constant spectra are examined at high frequencies.

The amount of ultraviolet radiation(UVR)reaching the Earth’s surface has been increasing as aresult of an increasingly thinner ozone layer.The UV-A component of the UVR is able to generate oxidative
stress in the compound eye and haemo lymph of Procambarus clarkii when the latter was exposed for as little as 15min daily for one week to UV-A.Changes in the eye involved corneal material, crystalline cones, pigments in cones talks and retinula cells, rhabdom integrity, haemocyte in filtration,and haemal spaces. UV-A had significant impacts on haemolymph iron and glucose, where as Ca ions were unaffected.Total Protein and Cu ions showed on lyin significant changes following UV-A radiation.Involvement of lipid peroxidation and DNA fragmentation was significant with regard to the tissue damage cause by the UV-A.UV A further more induced biological effects on serum electrophoretic patterns: some fractions either increased in size or others decreased. The described change scan be used as reference guide lines in evaluations of UV-A induced stress effects in P. clarkii

The amount of ultraviolet radiation(UVR)reaching the Earth’s surface has been increasing as aresult of an increasingly thinner ozone layer.The UV-A component of the UVR is able to generate oxidative
stress in the compound eye and haemo lymph of Procambarus clarkii when the latter was exposed for as little as 15min daily for one week to UV-A.Changes in the eye involved corneal material, crystalline cones, pigments in cones talks and retinula cells, rhabdom integrity, haemocyte in filtration,and haemal spaces. UV-A had significant impacts on haemolymph iron and glucose, where as Ca ions were unaffected.Total Protein and Cu ions showed on lyin significant changes following UV-A radiation.Involvement of lipid peroxidation and DNA fragmentation was significant with regard to the tissue damage cause by the UV-A.UV A further more induced biological effects on serum electrophoretic patterns: some fractions either increased in size or others decreased. The described change scan be used as reference guide lines in evaluations of UV-A induced stress effects in P. clarkii

The total structure factor, S(K), have been obtained for the chalcogenide Ge20Se80−xTex (where x =0, 10, 20, and 30 at. %) glasses using x-ray diffraction in the wave vector interval 0.28<=K
<=6.87 Å−1. The appearance of the first sharp diffraction peak in the structure factor indicates the presence of the intermediate range order. The radii of the first- and second-coordination shells
(r1 , r2) are increased linearly with Te addition. The large covalent radius of Te atom in compare with that of Se atom was behind the above linear increase. The first coordination number shows
insignificant changes with Te content. The obtained values of r1 / r2 ratio and the corresponding bond angle (theta) indicate that the structural units inside the present alloys are Ge(Se1/2)4 tetrahedra
connected by chains of the chalcogen atoms. Raman spectra confirm the above conclusion and in the same time exclude the existence of Ge(Te1/2)4 tetrahedra. Based on the chemical ordered network mode, Te–Te bonds are responsible for the different behavior of Te-rich (30 at. %) glass from others.

The total structure factor, S(K), have been obtained for the chalcogenide Ge20Se80−xTex (where x =0, 10, 20, and 30 at. %) glasses using x-ray diffraction in the wave vector interval 0.28<=K
<=6.87 Å−1. The appearance of the first sharp diffraction peak in the structure factor indicates the presence of the intermediate range order. The radii of the first- and second-coordination shells
(r1 , r2) are increased linearly with Te addition. The large covalent radius of Te atom in compare with that of Se atom was behind the above linear increase. The first coordination number shows
insignificant changes with Te content. The obtained values of r1 / r2 ratio and the corresponding bond angle (theta) indicate that the structural units inside the present alloys are Ge(Se1/2)4 tetrahedra
connected by chains of the chalcogen atoms. Raman spectra confirm the above conclusion and in the same time exclude the existence of Ge(Te1/2)4 tetrahedra. Based on the chemical ordered network mode, Te–Te bonds are responsible for the different behavior of Te-rich (30 at. %) glass from others.

The total structure factor, S(K), have been obtained for the chalcogenide Ge20Se80−xTex (where x =0, 10, 20, and 30 at. %) glasses using x-ray diffraction in the wave vector interval 0.28<=K
<=6.87 Å−1. The appearance of the first sharp diffraction peak in the structure factor indicates the presence of the intermediate range order. The radii of the first- and second-coordination shells
(r1 , r2) are increased linearly with Te addition. The large covalent radius of Te atom in compare with that of Se atom was behind the above linear increase. The first coordination number shows
insignificant changes with Te content. The obtained values of r1 / r2 ratio and the corresponding bond angle (theta) indicate that the structural units inside the present alloys are Ge(Se1/2)4 tetrahedra
connected by chains of the chalcogen atoms. Raman spectra confirm the above conclusion and in the same time exclude the existence of Ge(Te1/2)4 tetrahedra. Based on the chemical ordered network mode, Te–Te bonds are responsible for the different behavior of Te-rich (30 at. %) glass from others.