الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Hydroxyapatite, (HA), Ca10(PO4)6(OH)2, is a naturally occurring mineral found in the inorganic component of human bone and enamel. The constituent elements of HA are primarily calcium and phosphorous, with a stoichiometric calcium to phosphorous ratio of 1.667 capable of promoting intimate bone growth on to femoral implants. HAp is rendered a bioactive material since it has the ability to promote such growth with rapid fixation in what is also considered an osteoconductive process. The performance, lifespan and quality of the resultant biological coating in vivo is largely dependent on the coating morphology, phase composition, particle size and crystallinity of the powders pre-coating application
The present study aims to synthesize phase pure HAp powders by a simple precipitation and sol gel process. The crystal structures and morphologies of the as synthesized hydroxyapatite were analyzed by X-ray diffractions (X-ray), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive x-ray spectroscopy (EDX). Single phase HAP, with an average grain size of about 55 nm and surface area of 61 m2/g,
III
was obtained. The antibacterial activity of the as synthesized HA nanoparticles related to gram positive and gram negative bacteria’s were examined.
Then this thesis is focused on development optical properties of hydroxyapatite by doping it with Iron (III) chloride.
Finally, we study effect of gamma radiation in decrease crystal size of hydroxyapatite. latter achieved by developing two phase pure and near-stoichiometric composition HA samples (Ca/P ratio = 1.67), prepared by the co- precipitation synthesis route, and calculated crystal size of irradiated hydroxyapatite which showed that with increase dose of gamma radiation crystal size is decreased