This problem is distinct from biologic interference caused by acoustic energy generated by marine life, such as the squeaks of porpoises and other cetaceans, and measured by acoustic receivers.
32.
Transmission loss does not involve the source impedance and the radiation impedance inasmuch as it represents the difference between incident acoustic energy and that transmitted into an anechoic environment.
33.
Engineering and wind-tunnel tests revealed that the geometry of the rear fuselage and the engine exhaust created flutter-inducing turbulence that was aggravated by the high-frequency acoustic energy from the exhaust.
34.
For example, an explosion is the result of a chain reaction that transforms potential energy stored in chemical, mechanical, or nuclear form into kinetic energy, acoustic energy, and electromagnetic radiation.
35.
In the past, such calls for countermeasures before flight _ such as muffling material, baffles and mounting brackets that do not transmit acoustic energy _ were ignored to control costs.
36.
Liners are applied on the internal walls of the engine nacelle, both in the intake and by-pass ducts, and use Helmholtz resonance principle for the dissipation of incident acoustic energy.
37.
"' Geometrical acoustics "'or "'ray acoustics "'is a branch of acoustics that studies propagation of sound on the basis of the concept of rays considered as lines along which the acoustic energy is transported.
38.
He tested the range of frequency and found that transmitting acoustic energy between 18 kilohertz and 36 kilohertz, or just above the level that humans can hear, had a devastating effect on the larvae.
39.
This technology focuses acoustic energy into a fluid sample in order to eject droplets as small as a millionth of a millionth of a litre ( picoliter = 10 " 12 litre ).
40.
These standing waves can be considered a temporary storage of acoustic energy as they take a finite time to build up and a finite time to dissipate once the sound energy source has been removed.
