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.
The cause is not known. Vitiligo may be an autoimmune disease. These diseases happen when your immune system mistakenly attacks some part of your own body. In vitiligo, the immune system may destroy the melanocytes in the skin.It is also possible that one or more genes may make a person more likely to get the disorder. Some researchers think that the melanocytes destroy themselves. Others think that a single event such as sunburn or emotional distress can cause vitiligo.he disorder affects all races and both sexes equally, however, it is more noticeable in people with dark skin. People with certain autoimmune diseases (such as hyperthyroidism) are more likely to get vitiligo than people who donât have any autoimmune diseases.