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Drill stem test
A drill stem test (DST) is a well test that isolates a formation with packers so its pressure, fluids, and productivity can be measured before a well is completed.
Drilling
Drilling is the process of making a cylindrical hole with a rotating cutting tool, covering machining with twist drills and well drilling for water and energy.
Drilling and blasting
Drilling and blasting, also called drill and blast, is a rock excavation method that fragments rock with explosives in boreholes, used widely in tunnels and mining.
Drilling fluid
Drilling fluid, also called drilling mud, is the circulating fluid used in rotary drilling of wells to clean the hole, carry cuttings to the surface, and counterbalance formation pressure.
Drilling rig
A drilling rig, or drill rig, is the machine used to drill a wellbore for oil, gas, or geothermal resources, combining hoisting, rotating, and circulating systems on land or offshore.
Drilling riser
A drilling riser is the large-diameter pipe connecting a floating drilling vessel to the subsea blowout preventer on the seafloor, returning drilling mud to the surface.
Drillship
A drillship is a maritime vessel modified with a drilling rig and station-keeping equipment, held on location by anchors, thrusters, or both, for drilling in deep water.
Drinking water
Drinking water, also called potable water, is water safe enough for human consumption, managed through treatment and regulation; globally, coverage rose from 68% to 74% between 2015 and 2024.
Drinking Water Directive
The Drinking Water Directive is the European Union's binding law on water for human consumption, replacing the 1998 directive and setting enforceable limits for contaminants including lead and PFAS.
Drinking Water Inspectorate
The Drinking Water Inspectorate (DWI) is the drinking water quality regulator for public water supplies in England and Wales, formed in 1990 and employing about 70 staff.
Drinking water quality in the United States
Drinking water quality in the United States is governed by the Safe Drinking Water Act, under which the EPA sets enforceable standards for about 147,000 public water systems.
Drinking water quality standards
Drinking water quality standards define how clean drinking water must be: legally enforceable contaminant limits, treatment rules, and monitoring set by national authorities, with WHO guidelines as the international reference.
Drinking water supply
Drinking water supply: systems of source, treatment, storage, and distribution delivering safe water. 74% of people used safely managed services in 2024; 2.1 billion still lack them, per WHO/UNICEF JMP.
Drinking water treatment
Drinking water treatment: processes (coagulation, filtration, disinfection, GAC, ion exchange, reverse osmosis) that make raw water safe to drink; US routine disinfection began in Jersey City, 1908, cutting typhoid from 100 to 0.1 cases per 100,000.
Drip coffee maker
A drip coffee maker is an electric appliance that drips heated water over ground coffee in a filter, brewing into a carafe; it spread through American homes in the 1970s.
Drip irrigation
Drip irrigation, also called trickle irrigation, applies water slowly through emitters to the root zone, wetting far less soil than sprinklers and saving 30 to 60 percent of water.
Drive Pilot
Drive Pilot is Mercedes-Benz's SAE Level 3 automated driving system, available on the S-Class and EQS Sedan. Germany approved it in 2021, the first such approval worldwide.
Drive shaft
A drive shaft, also called a propeller shaft or cardan shaft, is a rotating mechanical component that transmits torque between two points of a machine.
Drive test
A drive test is a field measurement method in mobile network engineering in which an instrumented vehicle records signal strength, quality, and service performance from a cellular network.
Driveco
Driveco is a Paris-based electric-vehicle charging company founded in 2010 by Corsica Sole; it runs one of France's largest public charging networks and manufactures 22 kW AC chargers.
Driveline retarder
A driveline retarder is an auxiliary braking device that slows a commercial vehicle via fluid drag or magnetic eddy currents, keeping the wheel brakes cool on long downgrades.
Driven pile
A driven pile is a preformed foundation element, typically steel, precast concrete, or timber, forced into the ground by an impact hammer or vibratory driver.
Driver Alcohol Detection System for Safety
Driver Alcohol Detection System for Safety (DADSS) is a US research program by NHTSA and automakers developing sensors that detect driver intoxication and stop the vehicle.
Driver and Vehicle Licensing Agency
The Driver and Vehicle Licensing Agency (DVLA) is an executive agency of the UK Department for Transport that licenses drivers and vehicles, based in Swansea.
Driver's license
Driver's license (driving licence): official document certifying the right to drive specified vehicle categories, issued after testing. Covers history from Benz's 1888 permit, EU classes, costs, medical standards, international permits, and the 2025 EU digital licence directive.
Driver's licenses in the United States
A driver's license in the United States is a state-issued credential that certifies the holder's privilege to drive and serves as the country's most widely used identity document.
DriveTest (Ontario)
DriveTest is the brand under which Serco Canada delivers driver examination services in Ontario on behalf of the Ministry of Transportation, including knowledge tests, road tests, and application processing.
Drivetrain
A drivetrain, also called a driveline, is the set of components that carries mechanical power from a vehicle's engine or electric motor to its drive wheels, including the transmission, driveshaft, differential, and axles.
Driving
Driving is the controlled operation of a motor vehicle on a road, combining perception, decision-making, and vehicle control, and causing about 1.19 million deaths in 2021.
Driving licence in Brazil
The Carteira Nacional de Habilitação (CNH), Brazil's national driving license, authorizes driving motor vehicles in Brazil, with categories A through E and renewal every 10 to 3 years by age.