DUCRETE (Depleted Uranium Concrete) is a high density concrete alternative investigated for use in construction of casks for storage of radioactive waste.

The duck curve is a graph of power production over the course of a day that shows the timing imbalance between peak demand and renewable energy production.

In electrical engineering, electrical terms are associated into pairs called duals.

Dual-fuel engines utilises a lean-burn combustion process.

A GSHP which utilizes two compressors (generally of different capacities) connected to two refrigeration circuits to allow multiple modes of operation.

Dry steam plants use steam directly from a geothermal reservoir to turn generator turbines.

Dry steam is saturated steam that has been very slightly superheated.

Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact.

Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids).

A dry cell uses a paste electrolyte, with only enough moisture to allow current to flow.

Dry cask storage is a method of storing high-level radioactive waste, such as spent nuclear fuel that has already been cooled in the spent fuel pool for at least one year and often as much as ten years.

The dry-bulb temperature is the temperature of air measured by a thermometer freely exposed to the air, but shielded from radiation and moisture.

A method of speed control for AC generators that controls the prime mover. A reduction or increase in generator output has the opposite effect on the output frequency.

A drillship is a merchant vessel designed for use in exploratory offshore drilling of new oil and gas wells or for scientific drilling purposes.

A drilling rig is an integrated system that drills wells, such as oil or water wells, in the earth's subsurface.

In geotechnical engineering, drilling fluid, also called drilling mud, is used to aid the drilling of boreholes into the earth.

The Driller is a team leader in charge during the process of well drilling.

A drill string on a drilling rig is a column, or string, of drill pipe that transmits drilling fluid (via the mud pumps) and torque (via the kelly drive or top drive) to the drill bit.

Drill pipe, is hollow, thin-walled, steel or aluminium alloy piping that is used on drilling rigs.

Rock chippings cut from the formation by the drill bit, and brought to the surface with the mud.