Ultrasound produces heating, pressure changes and mechanical disturbances in tissue.

Naturally, in this case no mechanical disturbance of the system under examination can take place in the crucial stage of the process of measurement.

A soil clod, however, is not a ped but rather a mass of soil that results from mechanical disturbance.

Technically, sound is defined as a mechanical disturbance traveling through an elastic medium-a material that tends to return to its original condition after being deformed.

Besides fire suppression and conversion of the habitat, threats include herbicide use and mechanical disturbance such as mowing.

Small, rapid variations in a waveform due to mechanical disturbances or to changes in the characteristic of components.

Hammering or jarring: the mechanical disturbance tends to randomize the magnetic domains.

Larger fragments of the thallus may break away when the lichen dries or due to mechanical disturbances(see the section on reproduction in lichens).

The luminescence occurs as a brief (0.1 sec) blue flash (max 476 nm) when stimulated, usually by mechanical disturbance.

He says, "No mechanical disturbance is evident."