All articles starting with R
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Reciprocal cross
A reciprocal cross is a pair of breeding crosses, A females with B males and B males with A females, used to detect sex-linked and maternal inheritance.
Reciprocal inhibition
Reciprocal inhibition is a behavioral therapy principle, defined by Joseph Wolpe in 1954, in which anxiety is weakened by pairing feared stimuli with an incompatible response like deep muscle relaxation.
Reciprocal lattice
The reciprocal lattice, also known as reciprocal space or the inverse lattice, is the Fourier transform of a crystal's direct lattice and the setting for describing diffraction.
Reciprocal rank fusion
Reciprocal rank fusion (RRF) is an unsupervised method that merges ranked result lists from several search systems into one ranking by summing reciprocal ranks, introduced in 2009.
Reciprocal space mapping
Reciprocal space mapping (RSM) is a high-resolution X-ray diffraction technique that maps intensity over an area of reciprocal space, revealing lattice parameters, strain, and mosaicity in crystals and epitaxial films.
Reciprocal Tariff Act
The Reciprocal Tariff Act is the popular name for the Reciprocal Trade Agreements Act of 1934, which let the president cut tariffs by up to 50 percent.
Reciprocal teaching
Reciprocal teaching is an instructional strategy in which students take turns leading small-group dialogue about a text, using predicting, questioning, clarifying, and summarizing to improve reading comprehension.
Reciprocating compressor
A reciprocating compressor is a positive-displacement machine that raises gas pressure with pistons and valves, serving as one of four essential components of vapor compression refrigeration systems.
Reciprocating engine
Defined by pistons moving in cylinders to convert pressure into rotational motion, the reciprocating engine dominates land transport and powers roughly 99 percent of global transport.
Reciprocating saw
A reciprocating saw, often called a Sawzall or recip saw, is a handheld power saw that cuts wood, metal, and plastic with a rapid back-and-forth blade stroke.
Reciprocating tribometer
A reciprocating tribometer is a laboratory instrument that measures friction and wear between surfaces sliding back and forth under load, commonly a ball on a flat, standardized as ASTM G133.
Reciprocity (social psychology)
Reciprocity (social psychology): the norm of reciprocity, Gouldner's 1960 formulation, obligation to repay gifts and favors, Regan's Coca-Cola experiment, and direct and indirect reciprocity.
Reciprocity calibration (massive MIMO)
Reciprocity calibration (massive MIMO) compensates transmit and receive hardware mismatches in a TDD massive MIMO base station, letting it steer downlink beams from uplink pilots without feedback.
Reciprocity law
A reciprocity law is a theorem of number theory relating solvability of congruences modulo different primes, exemplified by quadratic reciprocity, first proved by Gauss in 1796.
Reciprocity Treaty of 1875
Reciprocity Treaty of 1875, US-Hawaii Treaty of Reciprocity: bilateral commercial reciprocity pact signed January 30, 1875 by Hamilton Fish and Elisha H. Allen, admitting Hawaiian sugar duty-free into the US, fueling a sugar boom and Pearl Harbor's 1887 cession.
Recirculating aquaculture system
Recirculating aquaculture system (RAS), also called reuse or reconditioning system: intensive fish farming that treats and recycles tank water, cutting water use to as little as one-tenth of single-pass flow, with biofiltration, high energy costs, and lower eutrophication but higher greenhouse gas impact than net pens.
RECK
RECK (reversion-inducing cysteine-rich protein with Kazal motifs), also called hRECK or ST15, is a GPI-anchored membrane glycoprotein and tumor suppressor that inhibits MMP-2, MMP-9, MT1-MMP, and ADAM10/17, and enables Wnt7-driven brain vascular development.
Reckful
Reckful (Byron Bernstein, d. 2 July 2020), World of Warcraft arena champion, first to reach 3000 rating, six-season Rank 1, MLG winner, early Twitch pioneer, Everland developer.
Reckitt
Reckitt (Reckitt Benckiser Group plc, LSE: RKT) is a British consumer health and hygiene company formed in 1999 by the merger of Reckitt & Colman and Benckiser NV; £14.2bn 2025 revenue, brands include Lysol, Dettol, Finish, Mucinex, Durex.
Reckless (Bryan Adams album)
Reckless (1984) is Bryan Adams' fourth studio album, produced with Bob Clearmountain and written with Jim Vallance; it hit #1 on Billboard in 1985, sold about 12 million copies, and launched "Summer of '69" and "Heaven".
Reckless Ben
Reckless Ben, real name Benjamin Paul Schneider (born 1995), is an American YouTuber with about 1.5 million subscribers known for undercover investigative documentaries on Scientology, McKamey Manor, Provo Canyon School, and the 2026 Bricks & Minifigs Lego dispute.
Reckless driving
Reckless driving is a traffic offense in which a driver acts with willful or wanton disregard for safety, a mental state above ordinary negligence, defined differently across US states.
Recklessness (law)
Recklessness (law): a fault standard of consciously disregarding a substantial, unjustifiable risk, sitting between knowledge and negligence in the Model Penal Code hierarchy; in England and Wales defined subjectively since R v G (2003), and in tort an interstitial standard marking the boundary of malice.
Recklinghausen
Recklinghausen, a city of about 120,000 in North Rhine-Westphalia at the Münsterland-Ruhr border, seat of Kreis Recklinghausen; first mentioned 1017, town since 1236, home of the Ruhrfestspiele since 1947.
Reckoning (R.E.M. album)
Reckoning, alternatively titled File Under Water, is R.E.M.'s second studio album (1984, I.R.S. Records), produced by Mitch Easter and Don Dixon; it peaked at No. 27 in the US and No. 91 in the UK and went Gold in 1991.
Reckoning (TV series)
Reckoning (2019-2020) is a 10-episode Australian psychological thriller by David Hubbard and David Eick for Playmaker/Sony Pictures Television, starring Aden Young and Sam Trammell, set in California, released on Netflix May 1, 2020; ended after one season.
Reclaimed asphalt pavement
Reclaimed asphalt pavement (RAP) is crushed and screened old asphalt pavement, reused in new asphalt mixes; the United States reused over 101 million tons in 2024.
Reclaimed asphalt shingles
Reclaimed asphalt shingles are processed roofing shingles from manufacturing scrap or residential tear-offs, ground and added to asphalt paving mixtures, supplying up to 20 percent of the mix's binder.
Reclaimed rubber
Reclaimed rubber is rubber made by converting scrap vulcanized rubber, mostly from worn tires, into a processible material that can be vulcanized again with sulfur.
Reclaimed water
Reclaimed water, also known as recycled water or wastewater reuse, is water from sinks, showers, and industry that is treated and used again for irrigation, industrial supply, or even drinking water.