a. The strike or line of bearing.
b. The direction of the line formed by the intersection of the individual
stratum with the horizontal plane. The direction of this line is
customarily referred to north. See also:strike
a. The azimuth of the principal plane of an aerial photograph. AGI
b. The direction of the principal line on a photograph. AGI
A measure of the directional properties of a transducer. It is the ratio
in decibels of the average intensity of response over the whole sphere
surrounding the projector or hydrophone to the intensity or response on
the acoustic axis. Hy
A method of carrying out mining works in which the owners, Board, or
Authority, carry out the scheme by employing labor and purchasing the
necessary equipment. The method is in contrast to work entrusted to
outside contractors for performance at a fixed sum. Nelson
A symmetrical array of points in direct space; used when comparison is
made with the direct lattice. Syn:Bravais lattice; crystal lattice.
The reaction of metals with dry gases, leading to the formation of oxides
or other compounds on the surface; it does not occur to a pronounced
extent except at elevated temperature. CTD
In a graph of particle distribution (screen analysis), a plot in which the
abscissa shows the size and the ordinate shows the percentage of sample of
that size. Pryor, 1
direct raw-water cooling system
A cooling system in which water, received from a constantly available
supply, such as a well or water system, is passed directly over the
cooling surfaces of the rectifier and discharged. Coal Age, 1
direct-reading capillary chart
A graduated scale printed on transparent paper, which, when used in the
prescribed manner, enables one to determine the true angle a borehole is
inclined from readings taken directly on the etch plane in an acid bottle.
This eliminates the need for a protractor or goniometer and for a
capillarity-correction chart. Long
a. A system of incline haulage, comprising one rope and one drum. The
engine hauls up the journey of loaded cars, then the empties are connected
to the rope and returned to the bottom by gravity.
See also:balanced direct-rope haulage
haulage. Nelson
b. Haulage in which a loaded truck is pulled up the slope by a hoist while
an empty one descends, perhaps passing halfway on a loop of single track.
Also called brake incline; engine plane. Pryor, 3
See:natural ore
A copyrighted trade name for green synthetic spinel.
A thin stratum of shale or other inorganic rock material in a coal seam.
Syn:shale band; dirt bed; dirt parting; stone band. AGI
a. Eng. A thin stratum of soft, earthy material interbedded with coal
seams. Syn:dirt band
b. Old soil in which trees, fragments of timber, and numerous plants are
found. Fay
Scot. A debris heap; a waste heap.
See:dirt band
A road scraper or a grading shovel, used in leveling or grading ground.
Fay
See:clay vein
Scot. A coal seam with thick partings of blaes or fireclay; a very ashy
coal.
The glare resulting in reduced visual performance and visibility caused by
the action of stray light, which enters the eye and scatters within. It
causes a "veiling luminescence" over the retina, which, in turn, has the
effect of reducing the perceived contrast of the objects being viewed.
CF:discomfort glare
a. The material extracted from the raw coal and finally thrown away. Also
called dirt; stone. BS, 5
b. The portion of an ingot cropped off to remove the pipe and other
defects. Also called crop. CTD