A timber framework or set for roof support. CTD
See:calamine
An electrolytic cell that is capable of producing electric energy by
electrochemical action. See also:cell
a. Corrosion associated with the current of a galvanic cell consisting of
two dissimilar conductors in an electrolyte or two similar conductors in
dissimilar electrolytes. Where the two dissimilar metals are in contact,
the resulting reaction is referred to as couple action. ASM, 1
b. The corrosion above normal corrosion of a metal that is associated with
the flow of current to a less active metal in the same solution and in
contact with the more active metal. Hunt
galvanic electromagnetic methods
Electrical exploration methods in which electric current is introduced in
the ground by means of contact electrodes and in which one determines the
magnetic field that is associated with the current. Schieferdecker
To coat with zinc. Fay
Immersion of clean steel or iron in bath of molten zinc for purpose of
forming a protective coating. Sherardizing is the process of heating iron
articles with zinc dust to a temperature at which a strong adherent
coating is formed. Electrolytic galvanizing is the electrodeposition of
zinc on the iron. See also:hot-dip coating
An instrument employed for detecting an electric current and showing its
direction. It differs from a galvanometer in being only qualitative.
Standard, 2
An instrument for measuring the heat generated by an electric current or
for measuring the current by the heat that it generates.
Standard, 2
A monoclinic mineral, (Ba2 (Fe,Mn)(VO4 )2 (OH) ;
brackebuschite group; forms prismatic crystals and aggregates of needles
with diaspore, ephesite, and bixbyite in manganese ore at Gamagara ridge,
Postmasburg, Republic of South Africa.
Braz. A wooden bowl, about 2 ft (0.6 m) wide at the mouth, and 5 in or 6
in (12.7 cm or 15.2 cm) deep, used for washing gold out of the auriferous
material collected in sluices and in river sand. Syn:batea
a. In a biaxial crystal, the largest index of refraction. AGI
b. The interaxial angle between the a and b crystallographic axes.
CF:alpha; beta. AGI
c. The cgs unit of magnetic field intensity commonly used in magnetic
exploration. It is equal to 10-5 Oe (7.957747 X 10-4
A/m). Syn:nanotesla
d. adj. Of or relating to one of three or more closely related minerals
and specifying a particular physical structure (esp. a polymorphous
modification); specif. said of a mineral that is stable at a temperature
higher than those of its alpha and beta polymorphs (e.g., gamma quartz or
gamma -quartz). AGI
A borehole measurement of gamma rays originating in a gamma-ray source in
the instrument and scattering back from the rock formation to a detector
shielded from the source. The amount of scattering is proportional to
electron density and, therefore, proportional to mass concentration so
that the measurement, after certain corrections, yields a density log of
the formation penetrated. AGI
In the United States a term for inspection by gamma rays. Osborne
The face-centered cubic form of pure iron, which is stable from 1,670 to
2,550 degrees F (910 to 1,400 degrees C). ASM, 1
Emission by radioactive substances of quanta of energy corresponding to
X-rays and visible light but with a much shorter wavelength than light.
May be detected by gamma-ray Geiger counters. AGI
A gamma-ray counter device built into a watertight case small enough in
diameter to be lowered into a borehole. Long
High-energy, short-wavelength, electromagnetic radiation emitted by a
nucleus. Energies of gamma rays are usually between 0.010 and 10 million
eV. X-rays also occur in this energy range but are of nonnuclear origin.
Gamma radiation usually accompanies alpha and beta emissions and always
accompanies fission. Gamma rays are very penetrating and are best
attenuated by dense materials like lead and depleted uranium.
Lyman
An instrument for measuring the energy distribution, or spectrum, of gamma
rays, whether from natural or artificial sources. It is used in airborne
remote sensing for potassium, thorium, and uranium. AGI
A log that measures the relative quantities of potassium, thorium, and
uranium present in the rocks penetrated by a borehole. Wyllie
The radioactivity log curve of the intensity of broad-spectrum,
undifferentiated natural gamma radiation emitted from the rocks in a cased
or uncased borehole. It is used for correlation, and for distinguishing
shales (which are usually richer in naturally radioactive elements) from
sandstones, carbonates, and evaporites. CF:spectral gamma-ray log
See also:radioactivity log