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.
Causes of Skin Moles. Prev Next. Moles are common skin growths that result from a natural process in the skin. Melanin is the natural pigment that gives skin, hair and the irises of the eyes their color. In the skin, melanin is produced in cells called melanocytes located in the two upper layers of the skin.