The gaseous form of substances which are normally in the solid or liquid state (at room temperature and pressure). The vapor can be changed back to the solid or liquid states either by increasing the pressure or decreasing the temperature alone.

A quantity capable of assuming two or more different values.

One of the principal methods used for the engineering control of occupational health hazards. The process causes fresh air to circulate to replace contaminated air that is simultaneously removed.

Dizziness due to vestibular dysfunction. In true vestibular vertigo the victim experiences a sensation of rotary motion of either himself or the environment. Vertigo may be experienced in aviators as a function of acceleration. In divers, vertigo may occur as a result of caloric stimulation or unequal middle ear pressurization (alternobaric vertigo). Permanent vestibular injury and vertigo may result from vestibular decompression sickness or round window rupture.

Any substance that produces blisters.

An oscillation wherein the quantity is a parameter that defines the motion of a mechanical system.

Systematically tabulated information concerning births, marriages, separations, divorces, and deaths based on registrations of these vital events.