A contact print that has largely replaced the blueprints. Pryor, 3
The British spelling of dike.
A method of retarding an electric winder or haulage, in which a direct
current is injected into the alternating-current winder motor stator
during the deceleration period; the motor then acts as an alternator, and
the negative load of the winding cycle is absorbed as electric power and
wasted as heat in the controller. See also:electric braking
Nelson
Usually found in seismographs or seismometers where damping of motion is
desired that is in proportion to the velocity of the moving mass.
AGI
A general term for the branch of geology that deals with the causes and
processes of geologic phenomena; physical geology. AGI
The head of fluid that would statically produce the pressure of a given
moving fluid. Syn:velocity head
a. An alternating or variable load. Osborne
b. See:live load
The total of the processes and effects of orogenic movements and
differential stresses in producing new rocks from old, with marked
structural and mineralogical changes due to crushing and shearing at low
temperatures and extensive recrystallization at higher temperatures. It
may involve large areas of the Earth's crust, i.e., be regional in
character. CF:dynamothermal metamorphism; regional metamorphism.
Syn:dynamometamorphism
See:penetration test
Maintainence of a drill ship's position through the use of outboard
engines on opposite sides of the vessel. The position is maintained by
automatic centering in a circle of sonar reflectors placed around the
drilling target, either on the bottom or suspended by taut wire buoys.
Several drilling ships are now equipped with this facility. Mining
a. An industrial explosive that is detonated by blasting caps. The
principal explosive ingredient is nitroglycerin. Diethyleneglycol
dinitrate, which is also explosive, is often added as a freezing-point
depressant. A dope, such as wood pulp, and an antacid, such as calcium
carbonate, are also essential. See also:blasting gelatin
such as ammonium nitrate, and fuels, such as vegetable fiber, are usually
added.
b. A general term for detonable explosives in which the principal
constituent, nitroglycerin, is contained within an absorbent substance.
"Detonable" is a significant part of the definition since there are
compositions that contain significant amounts of nitroglycerin but that
are not detonable and are not considered to be dynamite.
A powerful exploder usually operated by a vertical rack, which, on a
downward movement, drives an armature. At the end of the stroke of the
rack bar an internal short-circuiting device opens and the current
generated by the rapidly revolving armature passes into the shot-firing
circuit. See also:blasting machine; exploder. Nelson
Augen gneiss containing much microline and orthoclase.
Dynamic metamorphism.
Appliance used in engineering to measure power as output, input, or
transitional. Pryor, 3
A permissible explosive of the ammonium nitrate group. Stoces
A common type of metamorphism involving the effects of directed pressures
and shearing stress as well as a wide range of confining pressures and
temperatures. It is related both geographically and genetically to large
orogenic belts, and hence is regional in character.
CF:regional metamorphism; dynamic metamorphism. AGI
A high-strength, low-density permitted explosive; no water resistance. It
is used for coal blasting in a machine-cut seam of medium hardness in dry
conditions. Nelson
A natural antimonide of silver, Ag3 Sb ; color and streak,
silver-white; luster, metallic; usually tarnished; Mohs hardness, 3.5 to
4; sp gr, 9.74; found in Germany, France, and Canada. An ore of silver.
Syn:antimonial silver