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.
The rate at which melanin granules are formed in these cells and their concentration in the epidermis are inherited characteristics and major factors in skin color differences. When no melanin is produced, the involved patch of skin becomes white. When a white patch grows or spreads, the cause may be vitiligo.