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Bayer process

(Encyclopedia)Bayer process, procedure for obtaining alumina from the aluminum ore bauxite. The alumina can then be used for various industrial purposes or smelted to provide aluminum. The first step in the process...

density

(Encyclopedia)density, ratio of the mass of a substance to its volume, expressed, for example, in units of grams per cubic centimeter or pounds per cubic foot. The density of a pure substance varies little from sam...

caisson

(Encyclopedia)caisson kāˈsən, –sŏn [key] [Fr.,=big box], in engineering, a chamber, usually of steel but sometimes of wood or reinforced concrete, used in the construction of foundations or piers in or near a...

damp

(Encyclopedia)damp, in mining, any mixture of gases in an underground mine, especially oxygen-deficient or noxious gases. The term damp probably is derived from the German dampf, meaning fog or vapor. Several disti...

corns and calluses

(Encyclopedia)corns and calluses, thickenings of the outer layer of skin where there is irritation or constant pressure. Corns are cone-shaped with their points protruding into the dermis, or inner layer of skin. T...

Haber process

(Encyclopedia)Haber process häˈbər [key], commercial process for the synthesis of ammonia, NH3. Pure hydrogen and nitrogen gases are mixed in the appropriate proportion, heated to between 450℃ and 600℃, comp...

glaucoma

(Encyclopedia)glaucoma glôkōˈmə [key], ocular disorder characterized by pressure within the eyeball caused by an excessive amount of aqueous humor (the fluid substance filling the eyeball). This causes pressure...

boiler

(Encyclopedia)boiler, device for generating steam. It consists of two principal parts: the furnace, which provides heat, usually by burning a fuel, and the boiler proper, a device in which the heat changes water in...

hydraulic machine

(Encyclopedia)CE5 Hydraulic pressure: In any hydraulic device the pressure exerted by one piston is transmitted throughout the fluid. Since pressure equals force divided by area, a small force (F1) exerted on a ...

iron lung

(Encyclopedia)iron lung, device used to maintain artificial respiration over an extended period of time. Before the successful vaccination program against poliomyelitis, it was used mostly in treatment of that dise...