• Ranunculus repens (plant)

    buttercup: Major species: …North American wetlands; and the Eurasian creeping buttercup, or butter daisy (R. repens), widely naturalized in America. Both the pond crowfoot (R. peltatus) and the common water crowfoot (R. aquatilis) have broad floating leaves and finely dissected submerged leaves.

  • Ranunculus septentrionalis (plant)

    buttercup: Major species: … but widely introduced elsewhere; the swamp buttercup (R. hispidis) of eastern North American wetlands; and the Eurasian creeping buttercup, or butter daisy (R. repens), widely naturalized in America. Both the pond crowfoot (R. peltatus) and the common water crowfoot (R. aquatilis) have broad floating leaves and finely dissected

  • Ranvier’s tactile disk (anatomy)

    Louis-Antoine Ranvier: …that are now known as Ranvier’s tactile disks. With the French bacteriologist André-Victor Cornil he wrote Manual of Pathological Histology (1869), considered a landmark of 19th-century medicine.

  • Ranvier, Louis-Antoine (French histologist and pathologist)

    Louis-Antoine Ranvier was a French histologist and pathologist whose dynamic approach to the study of minute anatomy made his laboratories a world centre for students of histology and contributed especially to knowledge of nervous structure and function. Assistant to the eminent French physiologist

  • Ranvier, node of (anatomy)

    node of Ranvier, periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses. These interruptions in the myelin covering were first discovered in 1878 by French histologist and pathologist Louis-Antoine Ranvier, who

  • ranz des vaches (songs)

    Swiss literature: …was achieved by the various ranz des vaches (melodies sung, or played on the alphorn, by herdsmen).

  • Ranzania laevis (fish)

    mola: However, the slender mola (Ranzania laevis) is smaller, measuring no more than 1 meter (39.3 inches) long. Some classifications also include the southern sunfish (M. ramsayi) is slightly smaller, measuring about 3 meters (9.9 feet), and is native to the southwestern Pacific Ocean.

  • Rao, Dileep (American actor)

    Inception: …(Tom Hardy), chemist Yusuf (Dileep Rao), and “architect” Ariadne (Ellen Page), who is in charge of creating the dreamscapes the team will occupy. In order to plant the idea, Cobb and his crew must descend through several layers of dreaming to penetrate the target’s subconscious. In the process, however,…

  • Rao, K. Chandrasekhar (Indian politician)

    Telangana: History of Telangana: K. Chandrasekhar Rao, leader of the TRS, was named the state’s first chief minister. On June 2, 2024, Hyderabad ceased to be the capital of Andhra Pradesh, as agreed. On June 11, 2024, a day before Chandrababu Naidu was sworn in as the chief minister…

  • Rao, P.V. Narasimha (prime minister of India)

    P.V. Narasimha Rao was a leader of the Congress (I) Party faction of the Indian National Congress (Congress Party) and prime minister of India from 1991 to 1996. Widely recognized for his efforts to liberalize the Indian economy in the early 1990’s, Rao was conferred the Bharat Ratna, India’s

  • Rao, Pamulaparti Venkata Narasimha (prime minister of India)

    P.V. Narasimha Rao was a leader of the Congress (I) Party faction of the Indian National Congress (Congress Party) and prime minister of India from 1991 to 1996. Widely recognized for his efforts to liberalize the Indian economy in the early 1990’s, Rao was conferred the Bharat Ratna, India’s

  • Rao, Patthe Bapu (Indian singer-poet)

    South Asian arts: Folk theatre: Another famous singer-poet was Patthe Bapu Rao (1868–1941), a Brahman who married a beautiful low-caste dancer, Pawala. They were the biggest tamasha stars during the first quarter of the 20th century. The tamasha actress, commonly called the nautchi (meaning “nautch girl,” or “prostitute”) is the life and soul of…

  • Rao, Raja (Indian writer)

    Raja Rao was an author who was among the most significant Indian novelists writing in English during the middle decades of the 20th century. Descended from a distinguished Brahman family in southern India, Rao studied English at Nizam College, Hyderabad, and then at the University of Madras, where

  • Raoul (king of France)

    Rudolf was the duke of Burgundy (921–936) and later king of the West Franks, or France (923–936), who, after a stormy career typical of the general political instability that characterized the age, succeeded in consolidating his authority shortly before he died. Rudolf was the son-in-law of Robert

  • Raoul (island, New Zealand)

    Kermadec Islands: Raoul enjoys a mild climate and receives 57 in. (1,450 mm) of rainfall annually, some of which forms lagoons. Lying at the western edge of the Kermadec Trench, the group is frequently shaken by earth tremors.

  • Raoul de Houdan (French author and trouvère)

    Raoul de Houdenc was a French trouvère poet-musician of courtly romances, credited with writing one of the first French romances, told in an ornate, allegorical style. Little is known of Raoul’s life. His name could have originated from a dozen cities. Certain passages in his writings suggest that

  • Raoul de Houdenc (French author and trouvère)

    Raoul de Houdenc was a French trouvère poet-musician of courtly romances, credited with writing one of the first French romances, told in an ornate, allegorical style. Little is known of Raoul’s life. His name could have originated from a dozen cities. Certain passages in his writings suggest that

  • Raoul de Presles (French scholar)

    France: Culture and art: …learned and vernacular cultures narrowed: Raoul de Presles translated St. Augustine; Nicolas Oresme translated Aristotle. Christine de Pisan (1364–c. 1430) challenged traditional assertions of women’s inferiority, incorporated in texts such as the Roman de la Rose (The Romance of the Rose), the most popular literary work of the 13th century.…

  • Raoult’s law (chemistry)

    ideal solution: …statement of this condition is Raoult’s law, which is valid for many highly dilute solutions and for a limited class of concentrated solutions, namely, those in which the interactions between the molecules of solute and solvent are the same as those between the molecules of each substance by itself. Solutions…

  • Raoult, François-Marie (French chemist)

    François-Marie Raoult was a French chemist who formulated a law on solutions (called Raoult’s law) that made it possible to determine the molecular weights of dissolved substances. Raoult taught at the University of Grenoble from 1867 and was professor there from 1870 until his death. About 1886 he

  • RAP (French agency)

    Elf Aquitaine: In 1939 the Régie Autonome des Pétroles (RAP; “Autonomous Petroleum Administration”) was set up to exploit a gas deposit found near Saint-Marcet in the foothills of the Pyrenees, and in 1941 the Société Nationale des Pétroles d’Aquitaine (SNPA; “National Society for Petroleum in Aquitaine”) was founded to explore…

  • rap (music)

    rap, musical style in which rhythmic and/or rhyming speech is chanted (“rapped”) to musical accompaniment. This backing music, which can include digital sampling (music and sounds extracted from other recordings), is also called hip-hop, the name used to refer to a broader cultural movement that

  • rap metal (music)

    rap metal, subgenre of heavy metal music. Heavy metal tended to be one of rock’s most porous genres, influencing (and in turn being influenced by) such disparate sounds as psychedelic, glam, punk, and alternative rock. Rap metal (and the related genre, nu metal) represented a fusion of heavy metal

  • rap music (music)

    rap, musical style in which rhythmic and/or rhyming speech is chanted (“rapped”) to musical accompaniment. This backing music, which can include digital sampling (music and sounds extracted from other recordings), is also called hip-hop, the name used to refer to a broader cultural movement that

  • Rap on Race, A (work by Mead and Baldwin)

    Margaret Mead: Work and impact: …Continuities in Cultural Evolution (1964); A Rap on Race (1971, with James Baldwin); Male and Female: A Study of the Sexes in a Changing World (1949 ); Anthropology: A Human Science (1964); Culture and Commitment (1970); Ruth Benedict (1974), a biography of that anthropologist; and Blackberry Winter (1972), an autobiography…

  • Rap Sh!t, (American television series)

    Issa Rae: A Black Lady Sketch Show and Rap Sh!t: …Insecure was the television series Rap Sh!t, which premiered in 2022. It centers on a pair of female rappers as they try to make it in Miami. In addition to creating the series, Rae serves as an executive producer and a writer. The show was renewed for a second season,…

  • Rapa (island, French Polynesia)

    Tubuai Islands: …square miles [16 square km]), Rapa (15 square miles [39 square km]), Rimatara, (3 square miles [8 square km]), Rurutu (11 square miles [29 square km]), and Tubuai (18 square miles [47 square km])—as well as the tiny, uninhabited Marotiri Islands at the southern end of the chain, and Maria…

  • Rapa Nui (island, Chile)

    Easter Island, Chilean dependency in the eastern Pacific Ocean. It is the easternmost outpost of the Polynesian island world. It is famous for its giant stone statues. The island stands in isolation 1,200 miles (1,900 km) east of Pitcairn Island and 2,200 miles (3,540 km) west of Chile. Forming a

  • Rapace, Noomi (Swedish actress)

    Noomi Rapace is a Swedish actress who was best known for portraying Lisbeth Salander in film adaptations of Stieg Larsson’s Millennium trilogy of crime novels. Norén was the daughter of a Swedish actress and a Spanish flamenco singer. As a young child she lived with her mother and stepfather in

  • Rapace, Ola (Swedish actor)

    Noomi Rapace: …married (divorced 2011) the actor Ola Rapace, who later costarred with her in Svinalängorna (2010; Beyond), in which she portrayed a woman who must come to terms with her past as the abused daughter of alcoholic parents. Notable among Rapace’s other movies was the bleak Danish picture Daisy Diamond (2007),…

  • Rapacki Plan (United Nations history)

    Adam Rapacki: …was noted for his “Rapacki Plan” for an atom-bomb-free zone in Europe.

  • Rapacki, Adam (Polish diplomat)

    Adam Rapacki was a Polish socialist who joined the communists after World War II and who, as minister of foreign affairs, was noted for his “Rapacki Plan” for an atom-bomb-free zone in Europe. Son of Marian Rapacki, founder of the cooperative movement in Poland, Rapacki studied in France and Italy

  • rapakivi (igneous rock)

    Precambrian: Orogenic belts: …by tin-bearing crustal-melt granites, called rapakivi granites after their coarse, zoned feldspar megacrysts (that is, crystals that are significantly larger than the surrounding fine-grained matrix). The rocks in this zone probably formed as a result of mantle plume activity.

  • Rapallo (Italy)

    Rapallo, city, Genova provincia, Liguria regione, northwestern Italy, on the Levante Riviera at the head of Rapallo Gulf, southeast of Genoa. First mentioned in 964, Rapallo was sacked successively by the Lombards, Normans, and Swiss. It was the site of the Allied Conference of Rapallo in 1917, and

  • Rapallo, Treaty of (Soviet Union-Germany [1922])

    Treaty of Rapallo, (April 16, 1922) treaty between Germany and the Soviet Union, signed at Rapallo, Italy. Negotiated by Germany’s Walther Rathenau and the Soviet Union’s Georgy V. Chicherin, it reestablished normal relations between the two nations. The nations agreed to cancel all financial

  • rapamycin (drug)

    rapamycin, drug characterized primarily by its ability to suppress the immune system, which led to its use in the prevention of transplant rejection. Rapamycin is produced by the soil bacterium Streptomyces hygroscopicus. The drug’s name comes from Rapa Nui, the indigenous name of Easter Island,

  • Rapanos v. United States (law case)

    Clean Water Act: …the Court’s plurality opinion in Rapanos v. United States [2006]) that would significantly reduce the number of wetlands that the EPA could protect.

  • rape (plant)

    rapeseed, (Brassica napus, variety napus), plant of the mustard family (Brassicaceae) grown for its seeds, which yield canola, or rapeseed, oil. Canola oil is variously used in cooking, as an ingredient in soap and margarine, and as a lamp fuel (colza oil). The esterified form of the oil is used as

  • rape (crime)

    rape, unlawful sexual activity, most often involving sexual intercourse, against the will of the victim through force or the threat of force or with an individual who is incapable of giving legal consent because of minor status, mental illness, mental deficiency, intoxication, unconsciousness, or

  • Rape Me (song by Cobain)

    Nirvana: …as “All Apologies” and “Rape Me”—reached number one on the U.S. album charts. By this point, however, Cobain’s heroin use was out of control. After a reputed suicide attempt in Rome in March 1994, he entered a Los Angeles treatment centre. In a mysterious sequence of events, he returned…

  • Rape of Deianira, The (painting by Pollaiuolo)

    Albrecht Dürer: First journey to Italy: …figure of Hercules from Pollaiuolo’s The Rape of Deianira for his painting Hercules and the Birds of Stymphalis. A purely mythological painting in the Renaissance tradition, Hercules is exceptional among Dürer’s works. The centre panel from the Dresden Altarpiece, which Dürer painted in about 1498, is stylistically similar to Hercules…

  • Rape of Helen, The (poem by Colluthus)

    Colluthus of Lycopolis: …by only one extant poem, The Rape of Helen (which was discovered in Calabria, Italy). The short poem (394 verses) is in imitation of Homer and Nonnus and tells the story of Paris and Helen from the wedding of Peleus and Thetis down to Helen’s arrival at Troy. According to…

  • Rape of Lucrece, The (poem by Shakespeare)

    William Shakespeare: The poems of William Shakespeare: Venus and Adonis (1593) and The Rape of Lucrece (1594) are the only works that Shakespeare seems to have shepherded through the printing process. Both owe a good deal to Ovid , the Classical poet whose writings Shakespeare encountered repeatedly in school. These two poems are the only works for…

  • Rape of Lucretia, The (opera by Britten)

    Benjamin Britten: His later operas include The Rape of Lucretia (1946); the comic Albert Herring (1947); Billy Budd (1951; after Herman Melville); Gloriana (1953; written for the coronation of Queen Elizabeth II); The Turn of the Screw (1954; after Henry James); A Midsummer Night’s Dream (1960); Owen Wingrave (television, 1971); and…

  • Rape of Persephone, The (sculpture by Girardon)

    François Girardon: …Goujon’s Fontaine des Innocents, and The Rape of Persephone (1677–79; pedestal completed 1699), in which he challenges comparison with Giambologna’s Rape of the Sabines. The effect of this group is marred by its present situation in the centre of the colonnade at Versailles, where it can be seen from all…

  • Rape of Proserpine, The (work by Claudian)

    Claudian: …minor contains the mythological epic Raptus Proserpinae (“The Rape of Proserpine”), on which Claudian’s medieval fame largely depended. The second book of the epic has an elegiac epistle addressed to Florentinus, the city prefect, and reflects Claudian’s interest in the Eleusinian mysteries.

  • Rape of Shavi, The (work by Emecheta)

    Buchi Emecheta: Perhaps her strongest work, The Rape of Shavi (1983), is also the most difficult to categorize. Set in an imaginary idyllic African kingdom, it explores the dislocations that occur when a plane carrying Europeans seeking to escape an imminent nuclear disaster crashes.

  • Rape of the Bucket, The (work by Tassoni)

    Alessandro Tassoni: …poem La secchia rapita (The Rape of the Bucket), the earliest and, according to most critics, the best of many Italian works in that genre.

  • Rape of the Lock, The (poem by Pope)

    The Rape of the Lock, mock-epic poem in heroic couplets by Alexander Pope. The first version, published in 1712, consisted of two cantos; the final version, published in 1714, was expanded to five cantos. Based on an actual incident and written to reconcile the families that had been estranged by

  • Rape of the Sabines, The (painting by David)

    Jacques-Louis David: Later years: 1794–1825: …with a new giant canvas, The Sabines. The picture represents the moment in the story when, a few years after their abduction, the Sabine women, now contented wives and mothers, halt a battle between their Roman husbands and the Sabine men who have come on an unwanted rescue mission. In…

  • Rape of the Sabines, The (sculpture by Giambologna)

    Giambologna: Rape of a Sabine (1579–83; Loggia dei Lanzi, Florence), while uncluttered and monumental, is even more complex. The composition is subtly designed so that it can be viewed from any side with equal effect. In his fountain Mercury (c. 1580; Bargello, Florence) Giambologna uses the…

  • Rape Scene (work by Mendieta)

    Ana Mendieta: Moffitt Building Piece, Rape Scene, and Silueta series: …collections around the world as Rape Scene (1973).

  • rape shield law

    rape shield law, statute or court rule, introduced in the late 20th century, which limits the ability of the defendant’s counsel to introduce the accuser’s sexual history as evidence during a rape trial and therefore can prevent the accuser from being discredited by information that is not relevant

  • rapeseed (plant)

    rapeseed, (Brassica napus, variety napus), plant of the mustard family (Brassicaceae) grown for its seeds, which yield canola, or rapeseed, oil. Canola oil is variously used in cooking, as an ingredient in soap and margarine, and as a lamp fuel (colza oil). The esterified form of the oil is used as

  • rapeseed oil

    canola oil, vegetable oil made from the pressed seeds of rapeseed (Brassica napus variety napus), a relative of turnips and cabbage in the mustard family. Rapeseed oil has long been used in industry as a lubricant for engines and other machine parts, but, because of its high level of potentially

  • Rapetosaurus (dinosaur genus)

    titanosaur: …addition, some titanosaurs, such as Rapetosaurus and Saltasaurus, have been shown to have possessed osteoderms (armoured plates).

  • Raphael (Italian painter and architect)

    Raphael was a master painter and architect of the Italian High Renaissance. Raphael is best known for his Madonnas and for his large figure compositions in the Vatican. His School of Athens in the Stanza della Segnatura, a room in Pope Julius II’s private apartments in the Vatican, is perhaps the

  • Raphael (archangel)

    Raphael, in the Bible, one of the archangels. In the apocryphal Old Testament (Hebrew Bible) Book of Tobit, he is the one who, in human disguise and under the name of Azarias (“Yahweh helps”), accompanied Tobias in his adventurous journey and conquered the demon Asmodeus. He is said (Tobit 12:15)

  • Raphael, Dana (American medical anthropologist)

    doula: In 1973 American medical anthropologist Dana Raphael used the term doula in the context of breastfeeding by new mothers, the success of which in certain populations appeared to depend on support by other women who often came from outside of the mother’s family. The term gradually came to also refer…

  • Raphael, House of (palace, Rome, Italy)

    Donato Bramante: Roman period of Donato Bramante: …design was that of the Palazzo Caprini (House of Raphael; later destroyed) in the Borgo, which became the model for many 16th-century palaces. This palazzo was later acquired by Raphael. According to Vasari, Bramante, about 1509, had designed the architectural background for the School of Athens by Raphael (1508–11; Vatican,…

  • Raphael, Yuval (Israeli singer and songwriter)

    Eurovision Song Contest: Eurovision and politics: …social media channels; Israeli entrant Yuval Raphael subsequently won the fan vote by a wide margin. In December 2025 the EBU adopted language that discouraged direct government influence in fan voting, but it declined to hold a vote on the inclusion of Israel in the contest. In response, five countries—Spain,…

  • Raphaelson, Samson (screenwriter)

    Ernst Lubitsch: Transition to sound: …contributors to the screenplay was Samson Raphaelson, who would collaborate frequently with Lubitsch throughout the director’s career. Lubitsch’s follow-up to The Smiling Lieutenant, the sombre antiwar drama Broken Lullaby (1932; also released as The Man I Killed), with Lionel Barrymore, was praised for its brilliant camera work, but with his…

  • Raphanus (plant genus)

    Brassicales: Brassicaceae, Capparaceae, and Cleomaceae: Thus, Raphanus (the radish genus) and Brassica (including broccoli and many other cruciferous vegetables) apparently have very different fruits. In the former, they split transversely into one-seeded segments, and in the latter they open in an ordinary fashion to release the individual seeds. Nonetheless, the two…

  • Raphanus raphanistrum (plant)

    wild radish, (Raphanus raphanistrum), widespread annual plant of the mustard family (Brassicaceae), native to Eurasia. Wild radish has naturalized throughout much of the world and is a noxious agricultural weed in many places. The plant is believed by some authorities to be the ancestor of the

  • Raphanus sativus (plant)

    radish, (Raphanus sativus), annual or biennial plant in the mustard family (Brassicaceae), grown for its large succulent taproot. The common radish is likely of Asian or Mediterranean origin and is cultivated worldwide. Radish roots are low in calories and are usually eaten raw; the young leaves

  • Raphanus sativus, variety longipinnatus (plant)

    daikon, (Raphanus sativus, variety longipinnatus), type of radish (family Brassicaceae) native to East Asia and cultivated for its edible white root. It can be used raw in much the same way as other radishes, and it is an important ingredient in the cookery of Korea, China, Japan, Vietnam, and

  • raphe (anatomy)

    scrotum: …a middle ridge called the raphe. Internally, the raphe connects to a muscular partition, the septum, which serves to divide the scrotum into its two areas.

  • Raphia (plant genus)

    palm: Distribution: Africa, Elaeis (oil palm) and Raphia (raffia palm, or jupati) in Africa and America, and Borassus (palmyra palm), Calamus (rattan palm), Hyphaene (doum palm), and Phoenix (date palm) in Africa and Asia. Numbers of individuals of a species may be few or many.

  • Raphia (city, border of the Gaza Strip and Egypt)

    Rafah, city along the border of the Gaza Strip and Egypt that, for most of the 20th and into the 21st century, has been bisected with an eastern half in the Gaza area and a western half in Egypt. In 2023–24 Gazans displaced by the Israel-Hamas War crowded into the city as it became the final refuge

  • Raphia farinifera (tree species)

    palm: Economic importance: …rain capes, baskets, raffia (Raphia farinifera), hats, hammocks, and the fiber known as piassava.

  • Raphia ruffia (tree)

    palm: Distribution: …areas; other species of the raffia palm dominate similar habitats in West Africa. The raffia palm occurs in nearly pure stands between marsh and dicotyledonous swamp forests along the Caribbean and Pacific coasts of Costa Rica, and Mauritia flexuosa is found in vast stands in inland parts of the Amazon…

  • Raphia taedigera (tree species)

    palm: Distribution: In the Amazon estuary Raphia taedigera covers extensive areas; other species of the raffia palm dominate similar habitats in West Africa. The raffia palm occurs in nearly pure stands between marsh and dicotyledonous swamp forests along the Caribbean and Pacific coasts of Costa Rica, and Mauritia flexuosa is found…

  • Raphidae (extinct bird family)

    columbiform: Annotated classification: Family Raphidae (dodoes and solitaires) Extinct but with no fossil record. Flightless, with much reduced furculum and wing, fused coracoid and scapula and no basipterygoid processes. Large; weight probably exceeded 10 kg (22 pounds). Limited to Mascarene Islands. 3 species.

  • raphide (botany)

    dumb cane: …with stinging crystals, known as raphides, that are composed of calcium oxalate. If chewed or ingested, the raphides and sap of the plant can irritate the mucous membranes and cause swelling and inflammation of the tongue and throat. The plant is considered to be toxic to cats, though ingestion is…

  • Raphidiodea (insect)

    snakefly, (order Raphidiodea or Raphidioptera), any of more than 175 species of insects that are easily recognized by their small head and long, slender “neck,” which is actually the elongated prothorax. The snakefly, about 15 mm (0.6 inch) long, has two pairs of similar, net-veined wings, long

  • Raphidioptera (insect)

    snakefly, (order Raphidiodea or Raphidioptera), any of more than 175 species of insects that are easily recognized by their small head and long, slender “neck,” which is actually the elongated prothorax. The snakefly, about 15 mm (0.6 inch) long, has two pairs of similar, net-veined wings, long

  • Raphidophyceae (algae class)

    algae: Annotated classification: Class Raphidophyceae (Chloromonadophyceae) Flagellates with mucocysts (mucilage-releasing bodies) occasionally found in freshwater or marine environments; fewer than 50 species; includes Chattonella, Gonyostomum, Heterosigma, Psammamonas, and Vacuolaria. Class Synurophyceae

  • Raphus cucullatus (extinct bird)

    dodo, (Raphus cucullatus), extinct flightless bird of Mauritius (an island of the Indian Ocean), one of the three extinct species that most classifications place with pigeons in the order Columbiformes. The other two species, which were once found on islands of the Indian Ocean, were the solitaires

  • Raphus solitarius (extinct bird)

    dodo: …Ocean, were the solitaires (Raphus solitarius of Réunion and Pezophaps solitaria of Rodrigues). Although a few classifications still assign the dodo and other members of the family to the order Raphiformes, most researchers consider the order outdated.

  • rapid application development (information science)

    information system: Internal information systems development: In various RAD methodologies a prototype—a preliminary working version of an application—is built quickly and inexpensively, albeit imperfectly. This prototype is turned over to the users, their reactions are collected, suggested modifications are incorporated, and successive prototype versions eventually evolve into the complete system. Formal processes for…

  • Rapid City (South Dakota, United States)

    Rapid City, city, seat (1877) of Pennington county, western South Dakota, U.S. It lies at the eastern edge of the Black Hills on Rapid Creek, from which it derived its name. It was settled in 1876 during the Black Hills gold rush. In the beginning the community grew slowly, and there was often

  • rapid eye movement sleep (physiology)

    REM sleep, one of two phases in the sleep cycle, in which a person experiences dreams, atonia (reduced muscle tone), irregular closed eye movements, and elevated levels of brain activity. The other phase of the human sleep cycle is known as non-rapid eye movement (NREM) sleep. A single sleep cycle,

  • rapid infiltration method (sanitation engineering)

    wastewater treatment: Land treatment: In the rapid infiltration method, the wastewater is stored in large ponds called recharge basins. Most of it percolates to the groundwater, and very little is absorbed by vegetation. For this method to work, soils must be highly permeable. In overland flow, wastewater is sprayed onto an…

  • rapid neutron capture (chemistry)

    chemical element: Neutron capture: …be distinguished: the r -process, rapid neutron capture; and the s -process, slow neutron capture. If neutrons are added to a stable nucleus, it is not long before the product nucleus becomes unstable and the neutron is converted into a proton. Outside a nucleus, a neutron decays into a proton…

  • rapid plasma reagin test (medicine)

    syphilis test: Nontreponemal tests include the rapid plasma reagin (RPR) test and the Venereal Disease Research Laboratory (VDRL) test, both of which are based on the detection in the blood of syphilis reagin (a type of serum antibody). Treponemal tests include the Treponema pallidum hemagglutination assay (TPHA; or T. pallidum particle

  • rapid process (chemistry)

    chemical element: Neutron capture: …be distinguished: the r -process, rapid neutron capture; and the s -process, slow neutron capture. If neutrons are added to a stable nucleus, it is not long before the product nucleus becomes unstable and the neutron is converted into a proton. Outside a nucleus, a neutron decays into a proton…

  • rapid reading

    Evelyn Wood: …a widely used system of high-speed reading.

  • rapid response collecting (art)

    Victoria and Albert Museum: Collection: …pioneered a program of so-called rapid response collecting, wherein the museum promptly acquired objects from significant moments in recent history. Pieces include the pussyhat, a knitted pink hat worn by participants in the 2017 Women’s March; an Xbox

  • Rapid Robert (American baseball player)

    Bob Feller was an American professional baseball player, a right-handed pitcher whose fastball made him a frequent leader in games won and strikeouts during his 18-year career with the Cleveland Indians (now the Cleveland Guardians) of the American League (AL). Feller made his major league debut at

  • rapid sand filter (chemistry)

    water supply system: Filtration: …are in use: slow and rapid. Slow filters require much more surface area than rapid filters and are difficult to clean. Most modern water-treatment plants now use rapid dual-media filters following coagulation and sedimentation. A dual-media filter consists of a layer of anthracite coal above a layer of fine sand.…

  • Rapid Support Forces (Darfur-based paramilitary group)

    Rapid Support Forces (RSF), Darfur-based paramilitary group in Sudan. The RSF was established in 2013 by the government to fight Sudanese rebels. After defeating those forces, the group grew into such a powerful and integral component of Sudan’s defenses that it came to challenge Sudan’s official

  • rapid transit

    rapid transit, system of railways, usually electric, that is used for local transit in a metropolitan area. A rapid transit line may run underground (subway), above street level (elevated transit line), or at street level. Rapid transit is distinguished from other forms of mass transit by its

  • rapid-fire field artillery gun (weaponry)

    World War I: Technology of war in 1914: …the machine gun and the rapid-fire field artillery gun. The modern machine gun, which had been developed in the 1880s and ’90s, was a reliable belt-fed gun capable of sustained rates of extremely rapid fire; it could fire 600 bullets per minute with a range of more than 1,000 yards…

  • rapid-hardening portland cement (cement)

    cement: Types of portland cement: … (Type I), modified (Type II), high-early-strength (Type III), low-heat (Type IV), and sulfate-resistant (Type V). In other countries Type II is omitted, and Type III is called rapid-hardening. Type V is known in some European countries as Ferrari cement.

  • rapids (hydrology)

    waterfall: …in channel gradient are called rapids.

  • rapier (sword)

    sword: …his weapon, and the thrust-and-parry rapier came into use.

  • Rapier (missile)

    rocket and missile system: Surface-to-air: …Soviet systems was the British Rapier, a short-range, semimobile system intended primarily for airfield defense. The Rapier missile was fired from a small, rotating launcher that was transported by trailer. In the initial version, deployed in the early 1970s and used with some success in 1982 in the Falklands conflict,…

  • rapier loom (weaving)

    rapier loom, a shuttleless weaving loom in which the filling yarn is carried through the shed of warp yarns to the other side of the loom by fingerlike carriers called rapiers. One type has a single long rapier that reaches across the loom’s width to carry the filling to the other side. Another

  • Rapier, James T. (American politician)

    James T. Rapier was a Black planter and labor organizer who was a member of the U.S. House of Representatives from Alabama during Reconstruction. Born in affluence—his father was a wealthy planter—Rapier was educated by private tutors and later studied at Montreal College (Canada), the University

  • Rapier, James Thomas (American politician)

    James T. Rapier was a Black planter and labor organizer who was a member of the U.S. House of Representatives from Alabama during Reconstruction. Born in affluence—his father was a wealthy planter—Rapier was educated by private tutors and later studied at Montreal College (Canada), the University