The average number of tons of a specified material to be carried by a
conveyor per hour, based on total operating-shift tonnage. NEMA, 2
An isometric mineral, Tl2 O3 ; black; forms minute crystals.
Letter name specifying the dimensions of bits, core barrels, and drill
rods in the A-size and W-group wireline diamond drilling system having a
core diameter of 30.1 mm and a hole diameter of 48 mm. Syn:AX
Cumming, 2
An isometric mineral, Ni2 Fe to Ni3 Fe .
Syn:native nickel-iron
Letter name specifying the dimensions of core, core barrels, and casing in
the A-size and X-series wireline diamond drilling system having a core
diameter of 30.1 mm and a hole diameter of 48 mm. The AX designation for
coring bits has been replaced by the AW designation. Syn:AW
Cumming, 2
a. Crystallographic directions through a crystal; used as lines of
reference. Hurlbut
b. Reference coordinates a, b, c, in crystallography, crystallographic
axes.
c. Directions of apparent isotropy in anisotropic crystals, optic axes.
d. Elements of rotational symmetry, symmetry axes.
e. In ellipsoids representing the Fletcher indicatrix of refractive
indices, semiaxes represent optic directions. Singular: axis. Also called
optic axes.
a. The acute angle between the two optic axes of a biaxial crystal. Its
symbol is 2V. AGI
b. The axial angle in air (symbol 2E) is the larger angle between the
optic axes after being refracted on leaving the crystal. AGI
c. See:optic angle
In experimental work with cylinders, a compression applied parallel with
the cylinder axis. It should be used in an appropriate sense only in the
interpretation of deformed rocks. AGI
In crystallography, the ratio of a unit distance along a crystallographic
axis and the corresponding angle between axes. Syn:lattice parameter
a. The interference figure that is obtained in convergent light when an
optic axis of the mineral being observed in thin section or as a fragment
coincides with the axis of the polarizing microscope. When a thin section
of a uniaxial mineral that was cut at right angles to an optic axis is
examined between crossed nicols (that is, between two polarizers, the
polarization planes of which are at right angles to each other) an
equal-armed shadowy cross and a series of spectrally colored, circular
bands are seen. If the mineral is biaxial, two shadowy parabolic curves
called isogyres and opening away from each other in a series of spectrally
colored, oval bands appear. Hess
b. In polarized light microscopy, an interference figure in which an optic
axis is centered in the field of view.
In pumping or in ventilation, the use of a propeller or impeller to
accelerate the load along the axis of the impeller. Pryor, 3
A compressor in which air is compressed in a series of stages as it flows
axially through a decreasing tubular area. Pryor, 3
a. A type of mine fan in which the mine air enters along the axis parallel
to the shaft and continues in this direction to the point of exhaust. The
axial-flow fan may have fixed blades (fixed-pitch fan) or adjustable
blades (variable-pitch fan). Two, four, or six aerofoil section blades
(like an aircraft wing) are usually employed. Also called a screw fan.
CF:radial-flow fan; mixed-flow fan.
See also:contra-rotating axial fan; mine-ventilation fan.
b. The compressed-air auxiliary fan consists essentially of a single-stage
axial-flow fan in which the rotor also forms the rotor of a compressed-air
turbine. The exhaust from the turbine is added to the ventilating air. The
result is a light and very compact machine, capable of the same duties as
the smaller sizes of electric auxiliary fans. Roberts, 1
See:axis
a. A more or less planar surface that intersects a fold in such a manner
that the limbs of the fold are symmetrically arranged with reference to
it.
b. The plane of the optic axes of an optically biaxial crystal.
c. A crystallographic plane that includes two crystallographic axes.
AGI
d. Of geologic structures, a plane that intersects the crest of the trough
or a fold such that the limbs, or sides, of the fold are more or less
symmetrically arrayed with reference to it.
Cleavage that is closely related to the axial planes of folds in the rock,
either being rigidly parallel to the axes, or diverging slightly on each
flank (fan cleavage). Most axial-plane cleavage is closely related to the
minor folds seen in individual outcrops, but some is merely parallel to
the regional fold axes. Most axial-plane cleavage is also slaty cleavage.
AGI
Large-scale secondary folding of preexisting folds, in response to
stresses that varied considerably from those that caused the original
folding. The axial planes of the original folds are folded. AGI
Foliation that developed parallel to the axial plane of a fold and
perpendicular to the principal deformational pressure. AGI
The distance between axial surfaces of adjacent antiforms and synforms
where the folds occur in the same layer or surface. AGI
A system for priming blast agents in which a core of priming material
extends through most or all of the blasting agent charge length.
The lengths of crystallographic axes defined in terms of their ratios
with, by convention, a set at unity where one axis is unique and b set at
unity where all three axes are required.