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transition temperature

The temperature at which the change from tough to brittle fracture occurs
in a notched bar impact test, or sometimes in other forms of test, e.g.,
notched tensile test. Syn:inversion point

transitman

One who operates a surveyor's transit. The person need not necessarily be
a graduate engineer. Crispin

translational fault

A fault in which there has been translational movement and no rotational
component of movement; dip in the two walls remains the same. It can be
strictly applied only to segments of faults. Syn:translatory fault
AGI

translational movement

Apparent fault-block displacement in which the blocks have not rotated
relative to one another, so that features that were parallel before
movement remain so afterwards. CF:rotational movement
See also:translational fault
AGI

translation lattice

See:crystal lattice

translatory fault

See:translational fault

translucency

A term used to describe mineral crystals sufficiently transparent to
transmit light. Also called subtransparency. CF:transparency
Pryor, 3

translucent

The optical property of a mineral to transmit light without objects being
visible. CF:opaque

translucent attritus

This term was first used by R. Thiessen in 1930 referring to the attritus
of ordinary humic coal, which is ordinarily composed largely of
transparent humic matter, with spores, cuticles, resins, and opaque matter
in minor proportions. Translucent attritus consists of the complex
residual organic matter, exclusive of anthraxylon, in bituminous lower
rank coal that transmits light in thin section. The following macerals of
the Stopes-Heerlen nomenclature are included in translucent attritus:
vitrinite less than 14 mu m thick; sporinite; cutinite; alginite;
resinite; and those parts of semifusinite, micrinite, and sclerotinite
that are weakly reflecting, that is semitranslucent. Translucent attritus
is a collective term and is not comparable with any of the microlithotypes
of the European system of nomenclature. IHCP

translucent glass

Glass that will admit rays of light to pass but through which objects
cannot be seen. Mersereau, 2

translucent humic degradation matter

Transparent humic matter consisting of irregular particles varying greatly
in shape and size. Although rounded or ovoid particles are not rare, humic
matter is mostly flattened in form and usually of frayed or tattered
appearance. The particles are of the same deep red color as the
anthraxylon strips, becoming lighter in thinner sections. Syn:THDM
IHCP

transmissibility

Term used to describe the ability of a system either to amplify or to
suppress an input vibration. It is the ratio of the response amplitude of
the system in steady-state forced vibration to the excitation amplitude.
The ratio may be between forces, displacements, velocities, or
accelerations. Hy

transmission

A mechanism that provides a variety of gear ratios for different load
conditions, speed, or direction of rotation.

transmission reversing

A transmission that has only a forward and reverse shift.
Nichols, 1

transmissometer

An instrument that measures the capability of a fluid to transmit light;
esp. one that measures the turbidity of water by determining the percent
transmission of a light beam. See also:turbidimeter

transmittance

Rate of heat flow per unit area per unit temperature difference.
Strock, 2

transmitted light

Light that has passed through an object, as distinguished from light
reflected from a surface. The nonopaque minerals in rocks are commonly
studied in transmitted plane-polarized light for characterization and
identification by use of a polarized-light microscope. Gems are usually
examined for imperfections by transmitted light. CF:birefringence;
index of refraction.

transmutation

The transformation of one element into another. Radioactive decay is an
example. Transmutation can also be accomplished by bombardment of atoms
with high-speed particles. AGI

transmute

In alchemy, the transformation of baser metals into more precious metals.
Gordon

transopaque

The property of a mineral to transmit light in part of the visible
spectrum while being opaque in another. CF:opaque

transparency

a. The degree to which visible light is transmitted through a solid. A
mineral is termed transparent if objects can be clearly seen through it,
as through glass; e.g., rock crystal (quartz), selenite (gypsum), Iceland
spar (calcite), and gem diamond. Syn:diaphaneity
opaque.
b. The capacity of seawater to transmit light; the depth to which water is
transparent may be measured by use of a Secchi disc.
c. A positive image, either black and white or in color, on a clear base
(glass or film), intended to be viewed by transmitted light; a
diapositive.