For a typical steel framed 30 ft by 30 ft office building bay, the fre-quency will be in the 5-8 Hz range. Frequency is a function of span (the longer the span, the lower the frequen-cy) and weight supported (the heavier the floor and the supported contents, the lower the frequency).
The following medical conditions are some of the possible causes of Skin color changes. There are likely to be other possible causes, so ask your doctor about your symptoms. 1  Causes of skin whitening:  Vitiligo.
Pigmentation is color in your skin produced by melanin, a natural pigment that also determines eye and hair color. However, if too much melanin is produced in one area, the result is a brown patch on your skin ( brown spot or hyper-pigmentation.)