Until today there are many works have been done to improve this white gold crop. This work is an attempt to study cotton fibers using X-ray technique, and I think as it looks easy but it is very useful to understand the the desired mechanical properties of cotton fiber through the crystalline structure of these fibers. In this work, I have studied the effect of crystalline structure defects on the elastic modulus of cotton fibers. As will as, I have selected different species of cotton fibers which cultivated in India and Yemen. I hope this research work will be first step to develop the cultivation of this crop in my country (Yemen).

Samir Osman Mohammed was born and grew up in Taiz, Yemen(1974) and received his Ph.D. in Physics from Mysore University, India in 2009 and B.Sc. degree in Physics Science from Taiz University,Yemen in 1997(with High Honors) and M.Sc. degree from Mousl University, Iraq in 2002(the first class). He is mainly interesting in environmental physics.