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.
There are some natural solutions that may help reduce the appearance of uneven skin tone. Though tasty in your smoothies, kiwi may also help. What Causes Uneven Skin Tone? Those dark areas on your face are caused by an increase in melanin production. Melanin is the natural pigment of your skin, and is responsible for your skin, hair, and eye color. Too much of it, however, can cause dark splotches and spots.