All articles starting with R
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Radix tree
A radix tree, also called a Patricia trie, is a space-saving tree data structure for storing strings, in which chains of single-child nodes are merged into one node.
Radixact
Radixact is a ring-gantry radiation therapy system made by Accuray that delivers helical intensity-modulated radiotherapy with integrated image guidance; FDA cleared in 2016, it is the fourth-generation TomoTherapy platform.
Radiy Khabirov
Radiy Khabirov is a Russian politician and United Russia member who has served as Head of the Republic of Bashkortostan since 2019, elected with 82 percent of the vote.
Radja Nainggolan
Radja Nainggolan, born 1988 in Antwerp, Belgian central midfielder nicknamed the Ninja; starred for Cagliari and Roma (203 apps, 33 goals), played for Inter, won 30 Belgium caps, omitted from the 2018 World Cup, later detained in a 2025 drug-trafficking investigation.
Radjah
Radjah is a monotypic shelduck genus holding the Radjah Shelduck (Radjah radjah, formerly Tadorna radjah), also called Burdekin duck, a white, chestnut-banded waterfowl of northern Australia, New Guinea, and the Moluccas, IUCN Least Concern.
Radko Dimitriev
Radko Dimitriev (Радко Димитриев, 1859–1918) was a Bulgarian-born general who commanded the Bulgarian Third Army in the First Balkan War before transferring to Russian service in 1914.
Radlett
Radlett is a commuter town in the parish of Aldenham, Hertfordshire, England, on Watling Street between Elstree and St Albans, with about 8,000 residents served by Radlett station.
Radley College
Radley College (College of St Peter, Radley) is a selective full-boarding boys' independent school for ages 13 to 18 near Oxford, founded in 1847 by William Sewell and Robert Corbet Singleton, known for its Social boarding houses, 800-acre campus, and 2019 ISI 'excellent' grading.
Radnik
Radnik is a Bosnian football club from Bijeljina, founded in 1945, best known for winning the Bosnian Cup in 2016 and seven Republika Srpska Cups.
Radoje Domanović
Radoje Domanović (Радоје Домановић), 1873 to 1908, was a Serbian writer, journalist, and political activist, regarded as the founder of the allegorical-satirical short story and best known for Danga, Vođa, and Stradija.
Radoje Drmanac
Radoje (Rade) Drmanac is a Serbian-born scientist and entrepreneur who co-founded Complete Genomics in 2005 and invented the DNA nanoball sequencing approach known as DNBSEQ.
Radom
Radom, city in Masovian Voivodeship, Poland (191,819 residents, 2025). Medieval royal city, 1401 Polish-Lithuanian union, 1767 Radom Confederation, arms industry, 1976 workers' protest.
Radom Biosphere Reserve
Radom Biosphere Reserve (Al Radom), South Darfur, Sudan: UNESCO MAB site designated 1982 (one source 1979) around Radom National Park, 1,250,970 ha of wooded savanna on the Adda and Umbelasha rivers near the Central African Republic border.
Radom Confederation
The Radom Confederation (konfederacja radomska) was an armed union of Polish-Lithuanian nobles formed at Radom in 1767 under Russian ambassador Nikolai Repnin, opposing King Stanisław August's reforms and placing the Commonwealth under a formal Russian guarantee.
Radome
A radome, or radar dome, is an electromagnetically transparent enclosure that protects an antenna while letting radio waves pass with minimal loss, covering ground radars, aircraft noses, and missile seekers.
Radomiak Radom
Radomiak Radom, Polish Ekstraklasa football club from Radom rooted in the 1910-1912 Radomskie Towarzystwo Sportowe; founded 1945, Ekstraklasa 1984/85, bankruptcy 2008, I liga champions 2020/21, returned to the top flight after 36 years.
Radomir Drasovic
Radomir Drašović (Радомир Драшовић), born 1997 in Belgrade, is a Serbian water polo defender and Paris 2024 Olympic gold medalist who plays for CN Marseille after Szolnok and Novi Beograd.
Radomir Putnik
Radomir Putnik (Радомир Путник), 1847 to 1917, was a Serbian field marshal and five-time Minister of War who led the army through the Balkan Wars and the First World War.
Radomyshl Raion
Radomyshl Raion (Радомишльський район), former district of Zhytomyr Oblast, Ukraine, centered on Radomyshl; 1,109.39 km², 34,262 people, four hromadas; abolished by the 2020 reform, territory now in Zhytomyr Raion.
Radon
Radon, a radioactive noble gas, atomic number 86, forms from decaying radium in soil, accumulates in homes, and causes about 21,000 lung cancer deaths yearly in the US.
Radon measure
A Radon measure is a Borel measure on a Hausdorff space that is locally finite and inner regular, meaning every Borel set is approximated by compact subsets; Johann Radon introduced it in 1913.
Radon mitigation
Radon mitigation is the set of techniques for reducing radon, a radioactive soil gas, inside buildings, most commonly by drawing soil gas away from the foundation.
Radon transform
The Radon transform is an integral transform mapping a function to its integrals over lines or hyperplanes, introduced by Johann Radon in 1917 and central to CT image reconstruction.
Radon-222
Radon-222, also called radium emanation, is a colorless radioactive noble gas with a 3.82-day half-life that forms from radium decay and is the leading source of indoor radiation exposure.
Radopholus similis
Radopholus similis, the burrowing nematode (nematodo barrenador), is a migratory endoparasitic plant nematode and top-10 pest causing banana toppling disease, citrus spreading decline, and pepper yellows, with banana and citrus host races.
Radoslav Filipovic
Radoslav Filipović (Радослав Филиповић), born 1997 in Novi Sad, is a Serbian water polo goalkeeper who won Olympic gold at Paris 2024 (13–11 over Croatia) and the 2026 European title with Serbia, playing for Radnički Kragujevac.
Radoslav R. Adžić
Radoslav R. Adžić, also known as Radoslav Adzic, is a Serbian electrochemist who pioneered platinum monolayer and core-shell electrocatalysts that cut platinum use in hydrogen fuel cells.
Radosław Kujawa
Radosław Kujawa is a Polish brigadier general and politician, Secretary of State in the Chancellery of the Prime Minister and former Head of the Military Intelligence Service.
Radosław Sikorski
Radosław Sikorski, also known as Radek Sikorski, is a Polish politician and former war correspondent serving as Minister of Foreign Affairs since 2023 and Deputy Prime Minister since 2025.
Radosław Żelezny
Radosław Dominik Żelezny (born 2006, Wrocław) is a Polish goalkeeper, 1.93 m, left-footed. Juventus youth 2022–2025, AS Roma from July 2025 (contract to 2029, shirt 91), on loan at Perugia in Serie C from August 2026.