drives definition

Collectively, stream invertebrates (almost wholly the aquatic larval stages of insects) that voluntarily or accidentally leave the substrate to move or float with the current, as well as terrestrial invertebrates that drop into the stream. Also, any detrital material transported in the water current.

(09 Oct 1997)

(DCLC) This is an electrostatic microinstability (frequencies at harmonics of the ion cyclotron frequency) which is of major concern in small mirror devices. Mode is driven by radial gradients in the electron density, and causes loss of ions due to non-conservation of magnetic moment (see adiabatic invariant) as they interact with the mode, and are dispersed in velocity space into the loss cone. Stabilisation is accomplished by increasing the plasma size and by partially filling the loss cone with a continuous extermal warm plasma stream.

(09 Oct 1997)

Fish and other predators that forage on invertebrates drifting on the water surface or in the water column.

(09 Oct 1997)

Random movement of a tooth to a position of greater stability.

An accumulation of water-carried debris along a contour or at the base of vegetation that provides direct evidence of prior inundation and often indicates the directional flow of flood waters.

(09 Oct 1997)

<radiobiology> Ordinarily particles placed in a magnetic field will simply orbit in circles, but if the magnetic field is not uniform, or curves, or there is an electrical field perpendicular to the magnetic field, or another force is applied perpendicular to the magnetic field, then the guiding centres of the particle orbits will drift (generally perpendicular to the magnetic field and to the applied force).

(09 Oct 1997)

Preferred term: drifts

<mechanics> A smooth drift. See Drift.

<radiobiology> A process that removes ions trapped in a thermal barrier using radial transport induced by an externally-applied radiofrequency field tuned to resonate with the azimuthal drift frequency.

(09 Oct 1997)

Slow ocular movements of greater amplitude than flicks, occurring during ocular fixation.

Synonyms: drift movements.

<radiobiology> Surface on which the guiding centre of a particle is constrained to move, due to the effects of the laws of adiabatic invariance on its drift motion.

(09 Oct 1997)

<radiobiology> Characteristic velocity at which the centre of a particle's orbit (guiding centre) drifts when drift motion (see above) occurs.

(09 Oct 1997)

<radiobiology> Oscillations in a magnetically-confined plasma arising in the presence of density gradients (such as at the plasma's surface). These resemble the waves that propagate at the interface of two fluids with different density in a gravitational field.

(09 Oct 1997)

1. A common way, road, or path, for driving cattle.

2. <chemical>

Same as Drift.

1. Wood drifted or floated by water.

2. Whatever is drifting or floating as on water. "The current of humanity, with its heavy proportion of very useless driftwood." (new Your Times)