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.
Share |. Vitiligo is a skin condition whose exact cause is unknown. In vitiligo, patches of skin lose their pigmentation when the pigment producing cells, the 'melanocytes' are attacked and destroyed. It may affect the skin, mucous membranes, eyes, inner ear or hairs leaving white patches. The usual type of vitiligo is called 'Vitiligo Vulgaris' (means: common vitiligo).