Agricultural waste Rice husk ash (RHA) is large and massive by the output of rice milling manufacture and contains a high amount of silica. Taking into account this verdant technology is utilized to get SiO2 Nanoparticles from rice shell ash. In this research, studies on the extraction methods of Nano-silica by combustion rice shell for 2 h at 700 °C were carried out and investigated. However, the Rice shell ash was undergoing to precipitation methods and sol gel method to manufacture Nano silica. precipitation methods involve refluxing silica from Rice shell ash in boiled (1.0,2.0 N NaOH). While the sol-gel method involves calcination of RHA was treated with HCl at 700 °C for 2 h followed by chemical treatment. Results of The Infrared spectral (IR) information display the presence of hydrogen-bonded silanol group and the siloxane groups in silica. The Optical properties through UV-visible spectroscopy of the Nano silica samples show a wide bandgap value and absorption peaks located in the UV region. As well as, the particles size analysis with values of (13.02, 16.83 and 23.96 nm) for the samples (1NSiO2, 2NSiO2, and acid leaching) were obtained respectively.

In this study, the bioactivity of CaSiO3 and Porecalin-CaSiO3 composites have been investigated utilizing X-ray diffraction (XRD) and scanning electron microscopy-Energy-dispersive X-ray spectroscopy (SEM-EDS). CaSiO3 and P-CaSiO3 are prepared by Sol-Gel method for different weight percentages of CaSiO3 (P90CS10, P80CS20 and P70CS30 wt. %). The in vitro bioactive properties have been carried out by immersed the powder and sintered samples on different compositions in simulated body fluids at 32 day to evaluate their bioactivity. Ca/P ratio have been calculated through EDS measurements. Structural characterization revealed the amorphous phase of CaSiO3 when heated at 700 °C and phase transition to the crystalline phase when heated at 950 °C, where pseudowollastonite (α-CaSiO3) and Ca2(SiO4) phases have been appeared. CaSiO3 showed better bioactive ability in comparison with its composites. In general, the bioactivity increases with increasing the CaSiO3 time of immersion in stimulated body fluid (SBF). The closest value to the stoichiometric hydroxyapatite, Ca10(PO4)6(OH)2 has been observed with P70CS30 sintered specimen where Ca/P was 1.694.

The resistance spot welding is adopted to joint dissimilar alloys such as aluminum alloy 1100 , and low carbon steel alloy 1008 by using cover plate. This study aims to optimization the best conditions of dissimilar welding of Aluminum with low carbon steel by RSW, and improving the properties of joints by many method. three different variables were used for the welding process: welding current (5, 6 ,7 and 8 KA), weld time (0.5, 1 and 1.5 sec) and electrode force (13.2 and 15.5 N).The welding joints are ―examined by a scanning electron microscope SEM and a X-ray diffraction‖ for the purpose of discussing the causes of the improved characteristics. The results revealed that the best welding conditions were under welding current 7 KA , weld time 1 sec and electrode force 13.2 KN, where the joint possessed the maximum shear force (4.8KN) and after improvement the tensile shear force become (6.02 KN), in addition to presence of the intermetallic compounds at optimum condition , such as AlFe3,Al5Fe4 and Al13Fe4, in the joint layer between dissimilar metal improves of the tensile shear forces and hardness in fusion zone.