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.
Cause of Vitiligo. Your skin is composed of three layers - the epidermis, the dermis and the subcutaneous tissue. The outermost layer of your skin is the epidermis. Melanin, the pigment that determines the color of your skin, hair and eyes, is produced in the epidermis. Melanin provides the coloring of your skin and helps protect it from damage from ultraviolet light.