The science and technology of two interacting surfaces in relative
motion and of related subjects and practices. The popular
equivalent is friction, wear, and lubrication in surfaces sliding
against each other, as in bearing and gears.
Turn-on-voltage
Applied voltage required to produce conduction in a diode.
ULSI
Ultra large scale integration; a chip with over 1,000,000
components.
Unit cell
The basic structural unit of a crystal structure, defined in terms
of atom (or ion) positions within a parallelepiped volume.
URL
Universal Resource Locator -- address of a World Wide Web site.
Usenet
Interlinked bulletin boards available via Internet and commercial
on-line services.
UV
Ultraviolet -- characterization of short-wavelength light for
exposing photoresist in making semiconductor devices.
Valence band
The electron energy band that contains the valence electrons in
solid materials.
Valence electrons
The electrons in the outermost occupied electron shell, that
participate in interatomic bonding.
van der Waals bond
A secondary, permanent or induced, interatomic bond between
adjacent molecular dipoles.
