All articles starting with R
22,461 articles
Rolipram
Rolipram is a selective PDE4 inhibitor synthesized in 1977 by Schering AG and trialed as an antidepressant, but nausea and vomiting kept it off the market.
Rolit
Rolit, a 1997 abstract board game by Adi Golad (Goliath), is a 2-4 player Reversi/Othello variant on an 8x8 board using 64 four-colored balls, with a free-choice rule replacing Reversi's passing rule.
Roll bending
Roll bending is a metal forming process in which sheet or plate metal is passed between powered rolls and takes a permanent curved radius, a continuous form of three-point bending.
Roll bonding
Roll bonding, also called roll welding, is a solid-state welding process in which stacked metal sheets are rolled until they bond, without melting either metal.
Roll Bounce
Roll Bounce is a 2005 American comedy-drama directed by Malcolm D. Lee, starring Bow Wow as a teenager whose skating crew moves to a rival Chicago rink in 1978.
Roll casting
Roll casting, also called strip casting, is a metal casting process in which molten metal solidifies between water-cooled counter-rotating rolls into thin strip or sheet.
Roll damping
Roll damping is the dissipation of energy opposing a ship's side-to-side rolling motion; roll is the largest and least damped ship motion, so it is central to predicting behavior in waves.
Roll film
Roll film is photographic film wound on a spool with opaque paper backing for daylight handling, used in medium-format cameras since George Eastman's 1885 roll film.
Roll forming
Roll forming is a continuous metal forming process in which flat sheet or strip is progressively bent into a constant cross-sectional profile by passing through successive pairs of profiled rolls.
Roll of Thunder, Hear My Cry
Roll of Thunder, Hear My Cry is Mildred D. Taylor's 1976 Newbery Medal novel about the Logan family, a landowning Black family in Depression-era Mississippi under Jim Crow, narrated by nine-year-old Cassie Logan.
Roll Over Beethoven
Roll Over Beethoven: 1956 Chuck Berry rock and roll single on Chess Records (B-side Drifting Heart) declaring rhythm and blues's triumph over classical music; Rolling Stone #97, National Recording Registry 2003, covered by the Beatles (1963) and Electric Light Orchestra (1973).
Roll the Bones
Roll the Bones is Rush's fourteenth studio album, released September 3, 1991 on Atlantic, produced by Rupert Hine, peaking at No. 3 on the Billboard 200, certified platinum, and known for its rap-inflected title track and mortality-themed lyrics.
Roll your own
Roll your own, also known as Choose 'Em or Flip, is a style of seven-card stud poker in which players choose which of their face-down cards to reveal.
Roll-on/roll-off
Roll-on/roll-off, or ro-ro, is a ship design in which wheeled cargo such as cars and trucks is driven on and off through ramps instead of being lifted by crane.
Roll-to-roll processing
Roll-to-roll processing, also called reel-to-reel or web processing, is a manufacturing method that builds structures continuously on a moving flexible web, used for RFID labels and solar cells.
Rolla
Rolla is a long narrative poem by Alfred de Musset, published in 1833, about Jacques Rolla, a ruined Parisian libertine who kills himself after a final night of debauchery.
Rollback (computing)
Rollback is the operation of restoring a system to a prior consistent state by undoing changes, most commonly discarding the updates made by an uncommitted database transaction.
Rollcage
A rollcage, also known as a safety cage or safety cell, is a multi-tubular structure fitted in a competition car's cockpit to protect occupants during rollovers and serious accidents.
Rolle's theorem
Rolle's theorem, also known as Rolle's lemma, is a result of differential calculus: a function continuous on [a, b], differentiable inside, and equal at the endpoints has some point with zero derivative.
Rolled oats
Rolled oats are whole oat groats steamed and pressed into flat flakes 0.4–1 mm thick, sold as old-fashioned, quick, or instant oats. Developed by Ferdinand Schumacher in the 1870s, they cook in about 10 minutes and have a GI of 40–69.
Rolleiflex
The Rolleiflex is a twin-lens reflex medium-format camera introduced in 1929 by Franke & Heidecke of Braunschweig, Germany, the first medium format roll film camera.
Roller brake
The roller brake is a Shimano cable-operated drum brake for bicycles, in which rollers press steel shoes against a drum inside the hub; it appeared in 1995 as the INTER-M.
Roller coaster
A roller coaster is an amusement ride in which open cars run along an elevated track, gaining energy from a lift hill or launch and coasting under gravity.
Roller derby
Roller derby is a full-contact team sport played on roller skates, in which each team's jammer scores points by lapping opposing blockers on an oval track.
Roller hockey
Roller hockey, also known as Hoquei em Patins, is a team sport on skates played in two forms: inline hockey, and quad or rink hockey on four-wheel skates.
Roller hockey (quad)
Roller hockey, also called rink hockey, is a team sport on quad skates in which five-player teams use curved sticks to drive a hard ball into the goal.
Roller Hockey International
Roller Hockey International (RHI) was a North American professional inline hockey league founded by Dennis Murphy, playing 1993 to 1999 (some accounts to 2001), with 24 teams, ESPN broadcasts, the Murphy Cup, and 4-on-4 high-scoring rules.
Roller linear guide
A roller linear guide is a profiled rail linear bearing in which cylindrical rollers recirculate between a rail and a runner block, carrying heavier loads than ball guides.
Roller screw
A roller screw is a mechanical transmission that converts rotary motion into linear motion using rollers rolling between a screw shaft and a nut, carrying about three times the load of a ball screw.
Roller skates
Roller skates are boots fitted with wheels for gliding over smooth, hard surfaces, popular since James Plimpton's steerable 1863 design and later revived by inline Rollerblades in 1979.