All articles starting with U
6,146 articles
Unimolecular reaction
A unimolecular reaction is a chemical reaction involving only one molecular entity, such as dissociation or isomerization; gas-phase rate constants depend on pressure, per Lindemann's 1922 mechanism.
Unimpaired runoff
Unimpaired runoff, also called full natural flow, is the flow a river would carry without dams or diversions, estimated by removing human effects from measured flows.
Unincorporated area
Unincorporated area: territory outside incorporated city or municipal boundaries, governed by county or township; over one-third of the U.S. population; counted via census designated places; distinct from incorporated municipalities with charters.
Uninhabited Planet Survive! (無人惑星サヴァイヴ)
Uninhabited Planet Survive! (無人惑星サヴァイヴ, Mujin Wakusei Survive), aka Planet Survival: 52-episode NHK Educational TV anime (Oct 2003–Oct 2004) by Madhouse and Telecom Animation Film, directed by Yuichiro Yano, about seven teens and a robot cat stranded on an uninhabited planet.
Unintended consequences
Unintended consequences are unplanned outcomes of actions or policies, rooted in Robert K. Merton's 1936 sociology and explained today by complexity thinking: feedback loops, adaptive agents, and limits to policy learning make policy effects hard to predict and evaluate.
Unintended pregnancy
Unintended pregnancy, also called unplanned pregnancy, is a pregnancy that was unwanted or mistimed. About 121 million occur yearly worldwide; measured via NSFG and DHS surveys; prevented by contraception.
Uninterruptible power supply
An uninterruptible power supply (UPS), or battery backup, is a device that instantly supplies battery power when the main power fails, letting computers and data centers keep running or shut down safely.
Uninvited (2024 film)
Uninvited (2024) is a Philippine mystery crime thriller directed by Dan Villegas, written by Dodo Dayao, starring Vilma Santos, Aga Muhlach, and Nadine Lustre; an MMFF 2024 revenge film about a mother targeting the billionaire behind her daughter's death, released on Netflix in 2025.
Union (American Civil War)
The Union was the loyal side in the American Civil War (1861–1865): 20-plus states under Abraham Lincoln, including slaveholding border states, fielding 2,672,341 soldiers, winning in 1865, ending slavery, and permanently strengthening federal authority.
Union (film)
Union (2024) is an American documentary by Stephen Maing and Brett Story about Chris Smalls and the Amazon Labor Union's campaign to unionize the JFK8 warehouse in Staten Island; Sundance Special Jury Award winner and Oscar shortlist.
Union (set theory)
The union, or set union, of two sets is the set of all objects belonging to at least one of them, written A ∪ B.
Union (Yes album)
Union (Yes album), 1991 Arista release, thirteenth Yes studio album merging the Big Generator lineup with Anderson Bruford Wakeman Howe as an octet; produced by Elias, Howe, Rabin, Offord; 84-date revolving-stage tour.
Union and election treaty of 1610 (agreement with Sigismund)
The Union and election treaty of 1610, concluded near Smolensk on 4 February 1610, offered the Russian throne to Prince Wladyslaw, son of Sigismund III of Poland.
Union Bank of India (यूनियन बैंक ऑफ़ इंडिया)
Union Bank of India (यूनियन बैंक ऑफ़ इंडिया) is a government-majority public sector bank headquartered in Mumbai, registered in 1919 and inaugurated by Mahatma Gandhi in 1921.
Union between Sweden and Norway
Union between Sweden and Norway (1814–1905), the United Kingdoms of Sweden and Norway: a personal union under one king with common foreign policy, formed after the 1814 Treaty of Kiel, dissolved peacefully in 1905 after Norway's 7 June declaration, referendum, and the Karlstad Agreement.
Union blockade
Union blockade: the US Navy's 1861–1865 closure of Confederate ports proclaimed by Lincoln on April 19, 1861, part of the Anaconda Plan. Over 3,000 miles of coast, 100,000 sailors; porous (runners got through over 90% at Carolina ports) but economically devastating, breaking Confederate transport, food supply, and currency.
Union Brescia
Union Brescia, Italian Serie C football club founded 17 July 2025 from the renamed FeralpiSalò after Brescia Calcio's bankruptcy; plays at Stadio Mario Rigamonti, president Giuseppe Pasini, coach Eugenio Corini.
Union budget of India
The Union budget of India, also known as the federal budget, is the government's annual statement of estimated receipts and expenditure, presented on 1 February each year.
Union Buildings
The Union Buildings (Afrikaans: Die Uniegebou) are the official seat of the government of South Africa, standing on Meintjeskop hill in Pretoria and housing The Presidency.
Union Canal (Scotland)
The Union Canal (Edinburgh and Glasgow Union Canal) is a 51 km lock-free contour canal from Lochrin Basin, Edinburgh, to the Falkirk Wheel; built 1818-1822 by Hugh Baird, closed in the 1960s, reopened in 2001.
Union Carbide
Union Carbide Corporation is an American chemicals company founded in 1898, known for pioneering petrochemicals and the 1984 Bhopal gas leak, and owned by Dow since 2001.
Union Carbide India Limited
Union Carbide India Limited (UCIL), Indian subsidiary 50.9% owned by Union Carbide Corporation, operated the Bhopal pesticide plant where the December 1984 methyl isocyanate leak killed thousands; sold in 1994 and renamed Eveready Industries India Limited.
Union City, New Jersey
Union City, New Jersey: dense Hudson County city formed June 1, 1925 by merging Union Hill and West Hoboken; 68,589 residents (2020), 81.8% Hispanic, historic embroidery capital on the Palisades near the Lincoln Tunnel.
Union College
Union College, Schenectady, New York: private undergraduate liberal arts college chartered 1795, home of the first social fraternity (Kappa Alpha, 1825), engineering within a liberal arts curriculum, about 2,000 students, NECHE-accredited since 2026.
Union Council of Ministers (संघ मंत्रिपरिषद)
Union Council of Ministers (संघ मंत्रिपरिषद): India's Union executive headed by the Prime Minister under Article 74, advising the President, collectively responsible to the Lok Sabha under Article 75(3), capped at 15% of Lok Sabha strength by the 91st Amendment.
Union County (film)
Union County is a 2026 American docudrama by Adam Meeks, his feature debut adapted from his 2020 short, starring Will Poulter and Noah Centineo as foster brothers in an Ohio drug court recovery program; Sundance premiere, Oscilloscope release, 95% Rotten Tomatoes.
Union County, North Carolina, United States
Union County, North Carolina: Piedmont county formed in 1842 from Mecklenburg and Anson, seat Monroe, part of the Charlotte-Concord-Gastonia MSA; 238,267 residents in 2020, among the state's fastest-growing counties.
Union Cycliste Internationale
Union Cycliste Internationale (UCI), world governing body for cycling, founded 14 April 1900 in Paris replacing the ICA; based in Aigle, Switzerland, with 205 national federations, 11 disciplines, and president David Lappartient since 2017.
Union Defence Force (South Africa)
The Union Defence Force (UDF) was the armed force of the Union of South Africa, established on 1 July 1912 and renamed the South African Defence Force in 1957.
Union Election Commission
The Union Election Commission (UEC) is Myanmar's electoral management body, responsible for administering parliamentary elections, registering voters, and regulating political parties; it administered the 2010, 2015, and 2020 elections.