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indoor stroke

Eng. That stroke of a Cornish pump that lifts the water at the bottom or
drawing lift.

indraft

The act of drawing in, or that which is drawn in; an inward flow; such as
an indraft of air. Standard, 2

induced breaks

The fine breaks or cracks that occur in the nether roof of a coal seam
following the holing of the coal or its removal, and having the same
general direction as that of the coal face itself. TIME

induced bursts

Rock bursts caused by stoping operations to distinguish them from
development bursts, which are called inherent. Spalding

induced caving

In the block caving mining method, the ore zone is undercut until the ore
material breaks apart and falls under gravity load into draw points. If
the ore zone is reluctant to fall under gravity loading, the fall is
sometimes induced with explosives set in boreholes drilled into the
orebody. This induced caving is generally accomplished from drifts above
the ore zone. SME, 1

induced cleavage

See:induced fracture

induced current

See:induction

induced fracture

Fracture formed in a roof bed as a result of mining operations. For
example, on longwall faces fractures are formed in a shale roof parallel
to and along successive lines of face. They are induced after coal cutting
and become intensified at the end of the loading shift. The distance
between the fractures coincides, roughly, with the depth of cut.
See also:break

induced magnetization

The magnetic field spontaneously induced in a volume of rock by the
uniform action of an applied field. Its direction and magnitude are
parallel and proportional, respectively, to the applied field. In the
absence of remanent magnetization, induced magnetization is the magnetic
moment per unit volume. See also:remanent magnetization

induced polarization

The production of a double layer of charge at a mineral interface, or
production of changes in double-layer density of charge, brought about by
application of an electric or magnetic field (induced electrical or
magnetic polarization). Induced electrical polarization is manifested
either by a decay of voltage in the Earth following the cessation of an
excitation current pulse, or by a frequency dependence of the apparent
resistivity of the Earth. Abbrev: IP. AGI

induction

The production of magnetization or electrification in a body by the mere
proximity of magnetized or electrified bodies, or of an electric current
in a conductor by the variation of the magnetic field in its vicinity.
Syn:induced current

induction balance

An apparatus for measuring changes of conductivity, detecting the
proximity of metallic bodies, etc., by noting extremely minute changes in
an electric current. Standard, 2

induction furnace

An alternating-current electric furnace in which the primary conductor is
coiled and generates, by electromagnetic induction, a secondary current
that develops heat within the metal charge. ASM, 1

induction hardening

Quench hardening in which the heat is generated by electrical induction.
ASM, 1

induction log

A continuous record of the conductivity of strata traversed by a borehole
as a function of depth.

induction period

A term used with reference to instantaneous caps to describe the time
between the bridge break and the detonation of the base charge.
Streefkerk

induction time

The interval between the bursting and lag times of a detonator.
BS, 12

inductively coupled plasma spectroscopy

An atomic emission spectroscopy analytical technique where liquid
solutions are passed through a quartz tube surrounded by a high-frequency
induction coil for heating the sample to high temperatures. It is an
important method for measuring trace element concentrations.

inductive method

An electrical exploration method in which electric current is introduced
into the ground by means of electromagnetic induction and in which the
magnetic field associated with the current is determined. AGI

indurated

Said of a rock or soil hardened or consolidated by pressure, cementation,
or heat. AGI

induration

a. The hardening of a rock or rock material by heat, pressure, or the
introduction of cementing material; esp. the process by which relatively
consolidated rock is made harder or more compact.
See also:lithification
b. The hardening of a soil horizon by chemical action to form a hardpan.
AGI