A monoclinic mineral, (Ce,La)2 Al(SiO4 )2 (OH) ;
weakly radioactive; green to olive; in contact zones at Bastnaes, Sweden.
Also spelled toernebohmite.
An encased explosive charge that is slid, lowered, or dropped into a
borehole and exploded to clear the hole of obstructions or to open
connections with passage ways to an oil or water supply. Also called a
bullet. Long
The effectiveness of a force that tends to rotate a body; the product of
the force and the perpendicular distance from its line of action to its
axis. AGI
Square or vertically fluted bar run on one type of auger drill to rotate,
raise, and lower the auger. See also:torque rod
A hydraulic coupling that utilizes slippage to multiply torque.
Nichols, 1
A device for measuring the actual torque transmitted to the drilling head
and/or to the drill-rod string. Long
A bar having the function of resisting or absorbing twisting strains.
Syn:torque bar
Tank thickener in which bottom rakes rise when overloaded with settled
material. Pryor, 3
The pressure exerted per square centimeter by a column of mercury 1 mm
high at a temperature of 0 degrees C where the acceleration of gravity is
980.665 cm/s2 . Hy
Beds of quicksand encountered below the chalk marl in the Anzin Coalfield,
in France.
A monoclinic mineral, (Mg,Mn)9 Zn4 (SO4 )2
(OH)22 .8H2 O ; related to mooreite and lawsonbauerite; at
Sterling Hill, NJ.
If a twisting couple is applied at a given section of a straight member,
that section rotates about some point in its plane. This point, which does
not move when the member twists, is the torsional center of that section.
It is sometimes defined as though identical with the flexural center, but
the two points do not always coincide. Syn:center of twist;
center of torsion; center of shear. CF:flexural center; elastic center;
elastic axis. Roark
A shear test in which a relatively thin test specimen of solid circular or
annular cross section, usually confined between rings, is subjected to an
axial load and to shear in torsion. In-place torsion shear tests may be
performed by pressing a dentated solid circular or annular plate against
the soil and measuring its resistance to rotation under a given axial
load. ASCE
A geophysical prospecting instrument that is used to determine distortions in the gravitational field. It consists of a pair of masses suspended by a
sensitive torsion fiber and so supported that they are displaced both
horizontally and vertically from each other. A measurement is made of the
rotation of the suspended system about the fiber; the rotation is caused
by slight differences in the gravitational attraction on the two masses.
Syn:Eoetvoes torsion balance
A break in the drill core caused by an accumulation of chips at the bit
face. When drilling is stopped to rechuck, these chips grip the core, and
the core is twisted and broken. CF:torsion fracture
A spiraled crack in a drill core caused by torque in a blocked bit or core
barrel. CF:torsion break
A seismograph with which the horizontal component of the earthquake can be
defined making use of the torsion of a vertical suspension thread on which
a stationary mass is fastened offcenter. Schieferdecker
Sometimes applied by miners to structures such as pots, bells, kettles,
and other rock masses that tend to fall easily from the roof of a coal
mine. See also:pot bottom; camel back. AGI
See:turbulent flow
The operation of raising the grade or purity of a concentrate by violent
stirring, followed by packing, in a kieve or open dolly tub. Chimming is a
similar process on a smaller scale. See:tozing