1 Therefore, the idea is to use a set of optimum conditions to get the most efficient yield of ammonia and this involves getting a low % yield (e.g. 8% - 15% conversion) but fast. 2  Described below are the conditions to give the most economic production of ammonia.
Causes of Vitiligo. Melanin is the pigment that gives the skin its characteristic color. Vitiligo is caused by a loss of pigment in the skin, due to destruction of pigment-forming cells known as melanocytes. The exact cause of the destruction of these cells is not known. One possible explanation might be that the body's immune system destroys the cells, as in other autoimmune conditions.
This is the theory that the susceptibility or predisposition to vitiligo is genetic, and that some defect in the genetic structure, makes people more susceptible to vitiligo. While we do see vitiligo in more than one family member about 20% of the time, about 80% of patients report no other family members with vitiligo.