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Pratt & Whitney R-2800 Double Wasp
The Pratt & Whitney R-2800 Double Wasp is an American 18-cylinder, air-cooled radial aircraft engine produced from 1939 to 1960, powering the P-47 Thunderbolt, F4U Corsair, and F6F Hellcat.
Pratt & Whitney R-4360 Wasp Major
The Pratt & Whitney R-4360 Wasp Major is an American 28-cylinder, four-row air-cooled radial aircraft engine built from 1944 to 1955, powering the B-36, B-50, and Boeing 377 Stratocruiser.
Pratt & Whitney R-985 Wasp Junior
Pratt & Whitney R-985 Wasp Junior: nine-cylinder air-cooled supercharged radial aircraft engine, 300–450 hp, 985 cu in, first certificated January 1930; 39,037 built 1929–1953; powered Beech 18, Lockheed Electra, Grumman Goose, DHC Beaver, and WWII trainers.
Pratt & Whitney TF30
The Pratt & Whitney TF30 is an American afterburning turbofan engine that powered the F-111 and F-14A Tomcat, the first American turbofan with an afterburner.
Pratt & Whitney Wasp series
Pratt & Whitney Wasp series: family of air-cooled radial piston aircraft engines from the 1925 R-1340 Wasp through the R-1830 Twin Wasp (173,618 built) and R-4360 Wasp Major, powering DC-3, B-24, B-36.
Pratt truss
The Pratt truss is a bridge truss with diagonals in tension and verticals in compression, patented by Thomas and Caleb Pratt in 1844 and once the most common US bridge form.
Pravdinskoye Oil Field
Pravdinskoye Oil Field (Правдинское месторождение) is a large oil field in the Khanty-Mansi Autonomous Area of Western Siberia, Russia, discovered in 1964 and producing since 1968.
Praveen Chaudhari
Praveen Chaudhari (1937–2010) was an Indian-born American materials physicist who led IBM's T. J. Watson Research Center, directed Brookhaven National Laboratory, and won the National Medal of Technology in 1995.
Prayer hall
A prayer hall is the main interior space of a mosque where Muslims gather for congregational prayer, oriented toward the qibla, the direction of Mecca.
Pre-control (quality control)
Pre-control is a statistical process control technique that divides specification tolerance into colored zones operators use to adjust processes, developed in the 1950s by Rath and Strong.
Pre-dreadnought battleship
A pre-dreadnought battleship is a battleship built between roughly 1890 and 1905, carrying four heavy guns plus medium batteries, until HMS Dreadnought made the type obsolete in 1906.
Pre-ignition
Pre-ignition is the uncontrolled ignition of the fuel-air mixture in a spark-ignition engine by a hot surface before the spark plug fires, distinct from knock; its low-speed form, LSPI, damages pistons in turbocharged engines.
Pre-lithiation
Pre-lithiation is a battery manufacturing technique that adds extra active lithium to a lithium-ion cell, compensating for lithium irreversibly lost during the first charge and early cycling.
Pre-modern dam construction techniques
Pre-modern dam construction techniques built water barriers of masonry, earth, and rock without concrete or steel, from the Jawa Dam of the mid-4th millennium BC onward.
Pre-shared key
A pre-shared key (PSK) is a secret shared between two parties in advance and used to authenticate them during key exchanges such as IPsec VPNs.
Preact
Preact is a small, fast JavaScript library for building user interfaces with a virtual DOM, offering an API closely modeled on React at roughly 3 kB, with React compatibility through its preact/compat layer.
Preboot Execution Environment
The Preboot Execution Environment (PXE) is an industry-standard method for booting a computer over a network without local boot media, defined by Intel in the 1990s.
Precast concrete
Precast concrete is concrete cast and cured in a controlled factory environment using reusable forms, then transported to a construction site as a finished component, unlike cast-in-place concrete.
Precast concrete pavement
Precast concrete pavement (PCP) is a pavement construction method in which concrete slabs are fabricated in a plant and installed overnight for rapid, long-lasting repair of roads, ramps, and intersections.
Precast segmental construction
Precast segmental construction is a bridge-building method in which concrete segments cast in a plant are joined into a continuous span by post-tensioning, first used in Europe in the 1950s.
PRECEYES Surgical System
The PRECEYES Surgical System is a telemanipulated robot for vitreoretinal surgery developed by Preceyes B.V. in Eindhoven, first used inside a human eye in 2016 and CE-marked in 2019.
Precipitation-strengthened high-entropy alloys
Precipitation-strengthened high-entropy alloys are multi-principal-element alloys whose yield strength is raised by fine ordered nanoprecipitates, such as L1₂ and B2 particles, formed during quenching and aging.
Precisely (company)
Precisely (formerly Syncsort, founded 1968 as Whitlow Computer Systems) is a Burlington, MA-based data integrity software company serving 12,000+ customers in 100 countries, acquired by Clearlake and TA Associates in 2021.
Precision approach path indicator
A precision approach path indicator, or PAPI lights, is an airport lighting system showing red and white signals that guide pilots down the approach slope to a runway.
Precision engineering
Precision engineering is the branch of engineering concerned with designing, manufacturing, and measuring components to tight dimensional tolerances, underpinning semiconductor fabrication, aerospace, and medical device manufacturing, where thermal effects are the largest source of error.
Precision fermentation
Precision fermentation is the use of genetically engineered microorganisms, such as yeasts and fungi, to produce specific molecules like proteins and enzymes without using animals or plants.
Precision RTL
Precision RTL is an FPGA logic-synthesis tool, originally from Mentor Graphics and now sold by Siemens EDA, that turns Verilog or VHDL into netlists for multiple FPGA vendors.
Precision Runway Monitor
The Precision Runway Monitor (PRM) is an air traffic surveillance system that lets aircraft fly simultaneous independent instrument approaches to parallel runways as close as 3,000 feet apart.
Precision Scheduled Railroading
Precision Scheduled Railroading (PSR) is a freight railroad operating model developed by Hunter Harrison, first applied at Illinois Central, that manages freight at the carload level.
Precision-guided munition
The precision-guided munition, also known as a smart munition or precision-guided weapon, is a guided weapon meant to destroy a point target while minimizing collateral damage.