Mechanized rake used to loosen sluice bed or move ore or concentrate through a kiln or furnace,
Luminous radiation arising from rays from radioactive elements, particularly in mineral form.
Device for providing thrust produced by the expulsion of hot gases from a combustion chamber. Oxygen for burning the fuel would normally be carried in the vehicle, not collected from the atmosphere. See reaction propulsion, rocket propulsion and panel on Rocket.
The imaginary part of the impedance. Reactances are characterized by the storage of energy rather than by its dissipation as in resistance,
Large masses of limestone formed by reef- building organisms; found typically in the Craven district of Yorkshire where they have weathered out as rounded hills above the lower ground on the shales. These are of Carboniferous age.
A sunken joint between adjacent building- stones.
The number of bits which can be stored in a computer register,
Study of radiation-induced chemical effects eg decomposition, polymerization etc. Cf radiochemistry,
A bacterial colony produced by muta
A machine for closing, clinching or setting rivets. See hydraulic riveter, pneumatic riveter.