All articles starting with O
9,097 articles
Organophosphorus chemistry
Organophosphorus chemistry is the branch of chemistry studying compounds with phosphorus–carbon bonds, spanning phosphines, phosphates, phosphonates, ylides, and phosphazenes, applied in catalysis, medicine, agrochemicals, and flame retardants.
Organophosphorus compounds
Organophosphorus compounds are organic molecules with a P–C bond, which are synthesized industrially from P4 derivatives and span oxidation states from P(III) to P(V), used in flame retardants and ligands.
Organophotocatalysis with cyanoarenes
Organophotocatalysis with cyanoarenes uses metal-free donor–acceptor organic dyes, the prototype 4CzIPN introduced in 2016, as photocatalysts absorbing visible light to drive single-electron-transfer reactions, widely replacing ruthenium and iridium catalysts.
Organophotoredox catalysis
Organophotoredox catalysis is a branch of photoredox catalysis in which organic molecules absorb visible light and shuttle single electrons to generate radical intermediates under mild conditions.
Organosilicon chemistry
Organosilicon chemistry, the study of compounds containing silicon–carbon bonds, began with tetraethylsilane and now underpins a large silicone industry plus reagents for organic synthesis, pharmaceuticals, and materials.
Organosolv pretreatment
Organosolv pretreatment is a chemical fractionation method that cooks lignocellulosic biomass in aqueous organic solvent, often acid-catalyzed, to dissolve lignin and hemicellulose, leaving cellulose-rich pulp for biofuel use.
Organosolv pulping
Organosolv pulping is a chemical pulping method that dissolves lignin from wood using aqueous organic solvents, developed since the 1970s as an alternative to kraft pulping but never commercialized.
Organosulfur compounds
Organosulfur compounds are organic molecules containing a carbon–sulfur bond, spanning thiols, sulfides, disulfides, sulfoxides, sulfones, and thiophene, and central to odor chemistry, protein biochemistry, and industrial synthesis.
Organotherapy
Organotherapy, or opotherapy, is the historical treatment of disease with animal organ or gland extracts, launched by Brown-Séquard's 1889 testicular-extract self-experiment; thyroid and adrenal extracts worked, testicular extracts were placebo, and synthetic hormones replaced it.
Organotrifluoroborate
Organotrifluoroborates, organoboron anions of the form RBF₃⁻, are air- and moisture-stable crystalline salts typically isolated as potassium salts and used in Suzuki–Miyaura coupling and photoredox radical chemistry.
Organotypic culture
Organotypic culture is a cell culture method that grows cells or tissue in three dimensions, preserving the architecture and cell-type diversity of the original tissue.
Organotypic slice culture
Organotypic slice culture is a bench biology technique that keeps thin tissue slices, most often brain, alive for weeks to months while preserving their 3D architecture and synaptic connections.
Orgasm (ργασμός)
Orgasm (Greek ὀργασμός) is the climax of sexual arousal, with intense pleasure and rhythmic pelvic muscle contractions. Key facts: no standard definition, Masters and Johnson's four-phase response cycle, and a 22–30 point orgasm gap between men and women.
Orgasm Inc: The Story of OneTaste
2022 Netflix investigative documentary by Sarah Gibson and Sloane Klevin about the sexual wellness company OneTaste, its orgasmic meditation practice, founder Nicole Daedone, and subsequent forced labor convictions.
Orgasmic dysfunctions
Orgasmic dysfunctions (ICD-11 HA02, orgasmic dysfunction) are WHO-classified sexual dysfunctions of the subjective orgasm experience, chiefly anorgasmia (HA02.0) with lifelong/acquired and generalised/situational subtypes, plus hypohedonic orgasm, postorgasmic illness syndrome, and painful orgasm under HA02.Y.
Orgazmo
Orgazmo is a 1997 American comedy film written and directed by Trey Parker. It stars Parker as a Mormon missionary who takes a role as a superhero.
Orgburo
The Orgburo (Оргбюро), short for Organizational Bureau, was the Communist Party body directing organizational work and cadre appointments from 1919 until its abolition in 1952.
Orgeat syrup
Orgeat syrup, also called orzata, is a sweet non-alcoholic almond syrup with orange flower or rose water, originally a barley drink. Essential to the Mai Tai and tiki cocktails; homemade versions keep about two weeks refrigerated.
Orghana Khatun
Orghana Khatun, also spelled Orqina, was an Oirat noblewoman who ruled the Chagatai Khanate as regent from 1252 to 1260 for her son Mubarak Shah, the only woman to rule it.
Orgone
Orgone is a hypothetical life energy proposed by Wilhelm Reich in the 1930s, tied to his bion research, orgone accumulators, and cloudbuster; it is dismissed as pseudoscience and led to Reich's 1957 imprisonment.
Orgov Radio-Optical Telescope
The Orgov Radio-Optical Telescope (ROT-54/2), also called the Herouni Mirror Radio Telescope, is a 54-meter fixed hemispherical radio telescope with a 2.6-meter optical telescope on Mount Aragats, Armenia.
Orgueil meteorite
The Orgueil meteorite is a carbonaceous chondrite that fell as an observed fall near Orgueil, France, in 1864, and its composition is the reference standard for the solar system.
Orgy
Orgy (Greek orgia): originally secret Dionysiac rites of ancient Greek and Roman religion; the word shifted to mean drunken revelry and, in modern usage, multi-partner group sex, now studied as socially organized group sex cultures.
Orgy (band)
Orgy is a Los Angeles electronic rock/industrial band formed in 1997, led by Jay Gordon, whose 1998 debut Candyass and New Order "Blue Monday" cover made it a fixture of the late-1990s nu metal scene on Korn's Elementree label.
Orgy of the Damned
Orgy of the Damned is a 2024 blues cover album by guitarist Slash, his sixth solo album, featuring guest singers like Brian Johnson and Iggy Pop.
Orgy of the Dead
Orgy of the Dead is a 1965 American nudie-cutie horror film directed by Stephen C. Apostolof (A. C. Stephen) from Ed Wood Jr.'s screenplay and novel, starring Criswell as the Emperor of the Dead judging topless dancers in a moonlit cemetery.
Orgyia pseudotsugata
Orgyia pseudotsugata, the Douglas-fir tussock moth, a lymantriine moth defoliating Douglas-fir and true firs in western North America, with cyclical outbreaks collapsing via a specific nucleopolyhedrosis virus.
Orhan (أورخان غازي)
Orhan Gazi (أورخان غازي), second Ottoman ruler (1324–1362), son of Osman I; took Bursa (1326) and İznik (1331), won Pelekanon (1329), annexed Karesi, and began Ottoman settlement in Europe (Gallipoli 1354, Edirne 1361).
Orhan Kemal
Orhan Kemal, real name Mehmet Raşit Öğütçü (1914–1970), was a Turkish novelist and short-story writer known for social realist works about workers, migrants, and small tradesmen.
Orhan Pamuk
Orhan Pamuk (Ferit Orhan Pamuk), Turkish novelist born 1952 in Istanbul; first Turkish Nobel laureate in Literature (2006). Novels include The Black Book, My Name Is Red, Snow, and The Museum of Innocence; charged under Article 301 in 2005.