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.
Vitiligo is a disease in which the skin forms white patches. It occurs when melanocyte cells stop producing melanin, either because they die off or simply stop functioning. Causes of the condition are unclear, but it is thought to be an autoimmune disease. It can appear at any age and on any part of the body.