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 condition that causes patchy loss of skin coloring (pigmentation). The average age of onset of vitiligo is in the mid-twenties, but it can appear at any age.It tends to progress over time, with larger areas of the skin losing pigment.esearchers have identified several forms of vitiligo. Generalized vitiligo (also called nonsegmental vitiligo), which is the most common form, involves loss of pigment (depigmentation) in patches of skin all over the body.