Abstract: Atmospheric ducts, which are caused by the rapid decrease in the refractive index of the lower atmosphere, can trap the propagating signals. The trapping effects of the atmospheric ducts can ...

A dacryocystorhinostomy (DCR) is a surgery that creates a new path for tears to drain between your eyes and your nose. You may need this surgery if your tear duct has become blocked. The procedure can ...

Each breast has 15 to 20 sections, called lobes. They are arranged like the petals of a daisy. Each lobe has many smaller structures called lobules. These end in dozens of tiny bulbs that can produce ...