compression-rarefaction wave
21Rocket engine — RS 68 being tested at NASA s Stennis Space Center. The nearly transparent exhaust is due to this engine s exhaust being mostly superheated steam (water vapor from its propellants, hydrogen and oxygen) …
22Acoustic impedance — The acoustic impedance Z (or sound impedance) is a frequency f dependent parameter and is very useful, for example, for describing the behaviour of musical wind instruments. Mathematically, it is the sound pressure p divided by the particle… …
23Cavitation — is defined as the phenomenon of formation of vapour bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapour pressure. Cavitation is usually divided into two classes of behavior: inertial (or transient)… …
24test — 1. To prove; to try a substance; to determine the chemical nature of a substance by means of reagents. 2. A method of examination, as to determine the presence or absence of a definite disease or of some substance in any of the fluids, tissues,… …
25Active noise control — (ANC) (also known as noise cancellation, active noise reduction (ANR) or antinoise) is a method for reducing unwanted sound. Contents 1 Explanation 2 Applications 3 See also 4 …
26cycle — 1. A recurrent series of events. 2. A recurring period of time. 3. One successive compression and rarefaction of a wave, as of a sound wave. [G. kyklos, circle] anovulatory c. a …
27Neuronal encoding of sound — The neuronal encoding of sound is the representation of auditory sensation and perception in the nervous system. This article explores the basic physiological principles of sound perception, and traces hearing mechanisms from sound as pressure… …
28respiration — respirational, adj. /res peuh ray sheuhn/, n. 1. the act of respiring; inhalation and exhalation of air; breathing. 2. Biol. a. the sum total of the physical and chemical processes in an organism by which oxygen is conveyed to tissues and cells,… …
29sound — 1. n. & v. n. 1 a sensation caused in the ear by the vibration of the surrounding air or other medium. 2 a vibrations causing this sensation. b similar vibrations whether audible or not. 3 what is or may be heard. 4 an idea or impression conveyed …
30Radio acoustic sounding system — A radio acoustic sounding system (RASS) is a system for measuring the atmospheric lapse rate using backscattering of radio waves from an acoustic wave front to measure the speed of sound at various heights above the ground. This is possible… …
