Behavior of Ultrasound in Materials
Ultrasound is broadly defined as any sound having a frequency above 20 kHz, which is approximately the highest frequency that can be detected by the human ear. However, the acoustic microscopes emit ultrasound ranging from 5 MHz to beyond 400 MHz so that micrometre size resolution can be achieved. The ultrasound that penetrates a sample may be scattered, absorbed or reflected by the internal features or the material itself. These actions are analogous to the behavior of light. Ultrasound that is reflected from an internal feature, or (in some applications) that has traveled through the entire thickness of the sample, is used to make acoustic images.
Read more about this topic: Acoustic Microscopy
Famous quotes containing the words behavior and/or materials:
“... two men could be just alike in all their dispositions to verbal behavior under all possible sensory stimulations, and yet the meanings or ideas expressed in their identically triggered and identically sounding utterances could diverge radically, for the two men, in a wide range of cases.”
—Willard Van Orman Quine (b. 1908)
“He was no specialist except in the relation of things.... He took most of his materials at second hand.... But no matter who mined the gold, the image and superscription are his.”
—Woodrow Wilson (1856–1924)