61,984 articles
DR Class 52.80
The DR Class 52.80, or Rekolok 52.80, is a German steam locomotive rebuilt from 200 wartime Class 52 engines in East Germany between 1960 and 1967.
DR Class V 100
The DR Class V 100 was a family of diesel-hydraulic locomotives built for the East German Deutsche Reichsbahn from 1966, with 1,146 units replacing steam in light and medium service.
Dr Narla Tata Rao Thermal Power Station
Dr Narla Tata Rao Thermal Power Station, also known as Vijayawada Thermal Power Station, is a 2,560 MW coal-fired power station at Ibrahimpatnam in Andhra Pradesh, India, owned by APGENCO.
Dr. Babasaheb Ambedkar International Airport
Dr. Babasaheb Ambedkar International Airport, also known as Nagpur Airport, is the international airport serving Nagpur, Maharashtra, India. Commissioned in 1917–18, it anchors the MIHAN cargo hub.
Draft survey
A draft survey is a procedure that determines cargo weight loaded onto or discharged from a ship by measuring drafts and computing the change in displacement.
Draft tube
A draft tube is the conduit carrying water from the runner of a reaction turbine, such as a Francis or Kaplan, down to the tailrace, recovering kinetic energy.
Drafter
A drafter, also called a draftsperson, is a technical worker who uses CAD software to convert designs by engineers and architects into technical drawings, mostly specializing in architectural, civil, electrical, or mechanical drafting.
Drag chain
A drag chain, also called a chain drag, is a heavy pile of steel chain dragged along the seabed to stop a ship after its launch down a slipway.
Drag teaching
Drag teaching, also called lead-through teaching or hand guiding, is a robot programming method in which an operator physically moves the arm along a path the robot replays.
Drag-reducing agent
A drag-reducing agent, also called a flow improver, is a chemical additive injected in parts-per-million concentrations into pipelines to suppress turbulence and increase crude oil throughput without new pipe.
Dragados
Dragados is a Spanish construction company founded in 1941, known for underground works with over 550 projects in 20 countries, and part of the ACS Group since 2003.
Draganflyer X6
The Draganflyer X6 is a six-rotor unmanned aerial vehicle built by Draganfly Innovations of Saskatoon, Canada, launched in 2008 and flown by North American police for aerial photography.
Dragline excavator
A dragline excavator, also called a dragline crane, is a large cable-operated digging machine that drags a suspended bucket through the ground to fill and empty it.
Dragon 2
Dragon 2 is a reusable SpaceX spacecraft carrying astronauts and pressurized cargo to the International Space Station, flying in Crew Dragon and cargo Dragon variants.
Dragon 32/64
The Dragon 32 and Dragon 64 were 8-bit home computers made in Wales by Dragon Data, a Mettoy company, launched in 1982 and 1983 at £199 and £229, similar to the Tandy Color Computer.
Dragon boat
A dragon boat (赛龙舟) is a long paddled watercraft decorated with a dragon's head and tail, raced by crews of 10 to 20 paddlers, tied to China's Duanwu Festival.
Dragon drone
The dragon drone (Дрон-дракон) is a Ukrainian incendiary drone that drops thermite burning above 2,200 degrees Celsius to burn away tree cover concealing Russian troops, first seen in September 2024.
Dragon Fire (robot)
Dragon Fire, or Dragon Firefighter, is a Japanese firefighting robot developed at Tohoku University from 2016, a water-filled hose that flies on its own jets' thrust.
Dragon LNG Terminal
Dragon LNG Terminal is a liquefied natural gas import terminal at Milford Haven in Pembrokeshire, Wales, operational since 2009 and supplying over 10% of UK gas demand.
Dragon reactor
The Dragon reactor was the first experimental high-temperature gas-cooled reactor, a 20 MW helium-cooled design at Winfrith in Dorset built by twelve European countries and operated from 1964 to 1975.
Dragon Skin
Dragon Skin was a flexible body armor from Pinnacle Armor of Fresno, California, made of overlapping ceramic discs, that failed US military rifle-round testing in 2006.
Dragon's teeth (fortification)
Dragon's teeth, known in German as Drachenzähne, are pyramidal reinforced-concrete anti-tank obstacles set in multiple rows, used on the Siegfried Line, the Atlantic Wall, and in Ukraine since 2022.
Dragonfire (laser weapon)
DragonFire is a British 50 kW-class laser directed energy weapon developed by a consortium led by MBDA UK to shoot down drones, joining Royal Navy destroyers from 2027.
Dragonfly (yacht)
Dragonfly is a range of folding sailing trimarans built by Quorning Boats in Skærbæk, Denmark, whose patented Swing Wing system folds the outer hulls in under a minute.
Dragonfly algorithm
The Dragonfly algorithm is a swarm intelligence metaheuristic that solves single-objective, discrete, and multi-objective optimization problems by mimicking the static and dynamic swarming behavior of dragonflies.
Dragonfly Energy
Dragonfly Energy is a Reno, Nevada lithium battery maker founded in 2012 by Denis Phares, best known for its Battle Born Batteries brand and listed on Nasdaq in 2022.
Dragonfly topology
Dragonfly topology is a supercomputer interconnect design proposed in 2008 by Kim, Dally, Scott, and Abts, arranging routers in fully connected groups so packets cross one global link at most.
Dragunov SVU
The Dragunov SVU, designated OTs-03, is a Russian bullpup designated marksman rifle built on the Dragunov SVD action and produced in Tula since the mid-1990s for Russian law enforcement.
Drain cleaner
Drain cleaner, also known as drain opener, is a corrosive or enzymatic product that clears drain blockages with sulfuric acid, sodium hydroxide, oxidizers, or slow-acting enzymes, and is among the most dangerous products in households.
Drain-induced barrier lowering
Drain-induced barrier lowering (DIBL) is a short-channel effect in field-effect transistors in which drain voltage lowers the source-channel potential barrier, cutting threshold voltage and raising leakage.