Any mine gas, or mixture of gases, particularly those deficient in oxygen.
Damp is probably derived from the German dampf, meaning a fog or vapor.
See also:afterdamp; blackdamp; chokedamp; combustible gases; firedamp;
stinkdamp; white damp. Nelson
a. In seismology, a resistance, contrary to friction, independent of the
nature of the contacting surface. Being proportional to the speed of
motion, it diminishes with the latter to nothing. Schieferdecker
b. A force opposing vibration, damping acts to decrease the amplitudes of
successive free vibrations. Damping may result from internal friction
within the system, from air resistance, or from mechanical or magnetic
absorbers. CF:attenuation
c. The loss of amplitude of an oscillation, owing to absorption.
See also:critical damping; damping factor. AGI
In damped seismographs, this term is by definition equal to one-half the
ratio of the damping resistance (force per unit velocity) to the moving
mass. It has the dimensions of a frequency. AGI
In pyrometallurgy, reduction of air supply to a furnace, to lower
temperature or reduce working rate. Pryor, 3
The ratio of the observed damping to that required for critical damping.
See also:damping
a. The damping ratio for a system with viscous damping is the ratio of the
actual damping coefficient to the critical damping coefficient.
Hunt
b. The ratio of two equiphase peak amplitudes within one period of a
damped seismograph or seismometer. The ratio is always greater than unity
since the greater amplitude is divided by the succeeding amplitude.
AGI
In a blast furnace, the cast-iron plate that supports the dam or dam stone
in front. Fay
S. Staff. A large sheet placed as a curtain or partition across a gate
road to stop and turn an air current.
Mid. Mine air mixed with so much carbonic acid gas as to cause the lights
to burn badly or to go out.
Boreholes drilled to determine petrological and structural features of the
rock or overburden materials at or near the area on which the foundations
of a dam will rest. Long
The wall of firebrick or stone enclosing the front of the hearth in a
blast furnace. Fay
a. Mid. A tub or barrel, sometimes with and sometimes without wheels, in
which mine water is conveyed along underground roadways to the sump or
raised to the surface.
b. A small box or sledge for carrying coal or waste in a mine.
A cobaltoan variety of arsenopyrite.
An isometric mineral, Fe4 Be3 (SiO4 )3 S ;
vitreoresinous; forms series with genthelvite and helvite.
An orthorhombic mineral, CaB2 Si2 O8 ; resembles
topaz in habit, appearance, and properties; in marbles, low-temperature
veins, and placers.
Lowermost Paleocene or uppermost Cretaceous. AGI
A primary cell, with a constant electromotive force of about 1.1 V, having
as its electrodes: (1) copper in a copper sulfate solution, and (2) zinc
in dilute sulfuric acid or zinc sulfate--the two solutions being separated
by a porous partition. Webster 3rd
Pebbles for grinding media, of superior hardness, toughness, and
uniformity, found on the shores of Greenland. AIME, 1
A revolving mechanical puddler. See also:puddling
A monoclinic mineral, Mn2 (Fe2+ , Mg)5 Si8 O
22 (OH)2 ; amphibole group; has Fe2+ /(Mg + Fe
2+ ) = 0.5 to 1.0 ; columnar or fibrous; at Dannemora, Sweden.
An isometric mineral, Na21 Mg(SO4 )10 Cl3 .