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regulator door

See:scale door

regulus

Impure metal produced during smelting of ores or concentrates.
Pryor, 3

reheater

An apparatus for reheating a substance, as ingot steel, that has cooled or
partly cooled during some process. Standard, 2

reheater load

The amount of sensible heat in w (British thermal units per hour),
restored to the air in reheating. Hartman, 2

reheating furnace

The furnace in which metal ingots, billets, blooms, etc., are heated to
bring them to the temperature required for hot-working. CTD

Rehisshakenhobel

A plow developed from the Anbauhobel machine and designed for cutting thin
coal seams. The plow drives, instead of being on the face side of the
conveyor, are on the waste side and the plow chains run in two tubes along
the waste side of the conveyor chutes. See also:Anbauhobel
Nelson

reinerite

An orthorhombic mineral, Zn3 (AsO3 )2 ; blue to
green; at Tsumeb, Namibia. (Not renierite.)

reinforcing bar

a. The basic material used to form grouted roof belts.
b. Iron or steel bars of various cross-sectional shapes used to strengthen
concrete.
c. See:rebar; reenforcing bar.

reinforcing steel

Steel bars of various shapes used in concrete construction to give added
strength. Crispin

reinite

A pseudomorph, FeWO4 ; after scheelite(?).

reiteration

In surveying, angular measurement made first with vertical circle of
theodolite to right of sighting telescope, then repeated after transiting
this through 180 degrees . Also called face right, face left observation.
Pryor, 3

reject

a. The material extracted from the feed during cleaning for retreatment or
discard. BS, 5
b. The stone or dirt discarded from a coal preparation plant, washery, or
other process; has no value. See also:middlings; refuse; residue;
tailings. Nelson

reject elevator

An elevator for removing and draining the reject from a washing appliance.
Syn:refuse elevator

reject gate

The mechanism of the refuse extractor that may be manually or
automatically operated to control the rate of removal of reject from the
washbox. BS, 5

rejuvenation

The renewal of any geologic process, such as the revival of a stream's
erosive activity or the reactivation of a fissure.

relative age

The geologic age of a fossil organism, rock, geologic feature, or event,
defined relative to other organisms, rocks, features, or events rather
than in terms of years. CF:absolute age

relative biological effectiveness

The relative effectiveness of a given kind of ionizing radiation in
producing a biological response as compared with 250,000 electron-volt
gamma rays. Abbrev., rbe. Lyman

relative bulk strength

A measure of the energy available per unit volume of explosive as compared
to an equal volume of ANFO at a density of 0.81 g/cm3 ; it is
calculated by dividing the bulk strength of an explosive by the bulk
strength of ANFO and multiplying by 100.
See also:absolute bulk strength

relative compaction

a. For soil compaction, two types of tests are necessary: (1) determining
the dry density of the soil after a standard amount of compaction has been
applied, and (2) measuring the density of the soil in the field. The state
of compaction is expressed as the relative compaction, and is the
percentage ratio of the field density to the maximum density as determined
by standard compaction. The percentages of relative compaction are high,
since the initial relative compaction is about 80%. Nelson
b. The dry density of a soil in situ divided by the maximum dry density of
the soil as established by the Proctor compaction test or any other
standard test. See also:loose ground

relative consistency

The ratio of the liquid limit minus the natural water content to the
plasticity index. ASCE

relative density

a. The relative density or specific gravity of a substance denotes the
number of times the substance is heavier or lighter than water (for the
same volume). Relative density and specific gravity mean the same thing.
Morris
b. The ratio of the difference between the void ratio of a cohesionless
soil in the loosest state and any given void ratio to the difference
between its void ratios in the loosest and in the densest states.
ASCE