An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

(v.tr.) To direct the course of; to lead or guide. To serve as a medium for conveying; transmit.
(v.intr.) To act as a conductor.

From L. conductus, p.p. of conducere "to lead or bring together," from → com- "together" + ducere "to lead."

Hâxtan, hâzidan, from Mid.Pers. "to lead, guide, persuade," Av. hak-, hacaiti "to attach oneself to, to join," cf. Skt. sacate "accompanies, follows," Gk. hepesthai "to follow,", L. sequi "to follow;" PIE *sekw-.

The ability of a system to conduct electricity, calculated as the ratio of the current which flows to the potential difference present. This is the reciprocal of the → resistance, and is measured in → siemens or → mhos.

→ conduct + → -ance.

The transference of energy through a body, without visible motion of any part of the body. → induction; → reduction; → subduction; → transduction.

Verbal noun from → conduct.

An electron whose energy lies in the conduction band of a solid, where it is free to move under the influence of an electron field.

→ conduction; → electron.

In the energy spectrum of a solid, a range of energies in which electrons can move freely under the influence of an electrical field. Metals have many electrons in this range, insulators have none. In semiconductors the conduction band contains few electrons provided by impurity atoms or ejected from the valence bands by thermal energy or photon absorption.

→ conduction; → bande.

(Adj.) Having the property or capability of conducting.

From → conduct + -ive a suffix of adj.

1) General: A measure of the ability to transmit, as electricity, thermal energy, sound, and so on.
2) → electrical conductivity.
3) → thermal conductivity.

From → conductive + → -ity suffix forming abstract nouns expressing state or condition.

Substance, or body, which offers a relatively small resistance to the passage of an electric current.

Agent noun from conduce, → conduct, + → -tor.

A measure of a material's ability to conduct an electrical current. It is the reciprocal of the → resistivity. Conductivity is expressed by σ = ne²l/(2mv), where n is the number of electrons per cm³ volume of the → conductor, e is the → electron charge, l is the → mean free path, m is the → electron mass, and v is the arithmetic mean velocity of thermal motion of electrons at a given temperature.

→ electrical; → conductivity.

Photoconductivity due to the addition of impurities or external causes.

→ extrinsic; → photoconductivity.

Šidhâzandegi, → photoconductivity; borungin, → extrinsic.

A semiconductor, such as silicon, whose responsive properties can be altered by the addition of impurities. Copper- and mercury-doped germanium are both examples of this semiconductor material.

→ extrinsic; → semiconductor.

A type of → heat transfer by means of molecular agitation within a material without any motion of the material as a whole.

→ heat; → conduction.

A pure semiconductor containing no → impurity atoms. → extrinsic semiconductor.

→ intrinsic; → semiconductor.

The conductivity in a semiconductor caused by a flow of electrons, whereas p-type conductivity is caused by a flow of holes.

n standing for → negative; → type; → conductivity.

Any of various solid crystalline substances, such as germanium or silicon, which has conducting properties intermediate between metals and insulators.

→ semi-; → conductor.

In a semiconductor device, a region of transition between semiconducting regions of different electrical properties.

→ semiconductor; → junction.

The phenomenon in which certain materials, when cooled to a sufficiently low temperature, lose all resistance to the flow of electricity.

→ super-; → conductivity

A material which shows almost perfect conductivity at temperatures approaching absolute zero.

→ super-; → conductor.

A process that occurs in a medium where a → temperature gradient exists: dQ = -κ(dT/dx)dA.dt, where dQ is the amount of heat passing through the time dt across an area dA in the direction of the normal x to this area and toward the reduction in temperature, κ is the → thermal conductivity, and (dT/dx) the temperature gradient.

→ thermal; → conduction.

In → thermal conduction, the amount of heat passing across unit area per unit time and per unit → temperature gradient.

→ thermal; → conductivity.