All articles starting with O
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Opera houses of the South and West
Opera houses of the South and West were multifunction stage halls in small towns, built between roughly 1867 and 1920 and named for prestige rather than opera.
Opera Mini
Opera Mini is a mobile web browser developed by Opera Software, announced in 2005, that renders pages on remote servers to cut mobile data use by up to 90%.
Opéra sauvage
Opéra sauvage is a 1979 Polydor soundtrack album by Vangelis for Frédéric Rossif's French documentary series L'Opéra sauvage, recorded at Nemo Studios, London, with Jon Anderson on harp; seven tracks including Hymne, Rêve, and L'Enfant.
Operación Triunfo (Spain)
Operación Triunfo is a Spanish television music talent show, first broadcast by TVE in 2001, in which young singers train in an academy while the public votes weekly.
Operand
An operand is the number, variable, or data that an operator acts on in mathematics or computing, as in 7 + 5, where 7 and 5 are operands.
Operando 18O isotope labeling of the oxygen evolution reaction
Operando 18O isotope labeling of the oxygen evolution reaction is an experimental method that traces whether evolved O2 comes from water or the catalyst lattice.
Operando spectroscopy
Operando spectroscopy characterizes a material while it is working under real reaction conditions, measuring its structure and performance on the same sample at the same time.
Operando X-ray absorption spectroscopy
Operando X-ray absorption spectroscopy (operando XAS) is an analytical method that records a material's X-ray absorption spectrum while it is actively working, measuring catalytic activity at the same time.
Operando X-ray microscopy
Operando X-ray microscopy is the imaging of working batteries and catalysts with X-rays while their activity is measured at the same time, capturing short-lived states that extracted samples miss.
Operant conditioning
Operant conditioning is learning in which behavior is strengthened or weakened by its consequences, studied via Skinner boxes and reinforcement schedules (fixed/variable, interval/ratio), rooted in Thorndike's law of effect and applied in ABA, education, and animal training.
Operant conditioning chamber
The operant conditioning chamber, better known as the Skinner box, is a lab device invented by psychologist B. F. Skinner around 1930 to study operant conditioning in rats and pigeons.
Operant conditioning task
An operant conditioning task is a behavioral paradigm in which an animal's voluntary response produces a consequence, such as food reward or punishment, measuring instrumental learning and motivation.
Operário em Construção
"Operário em Construção" is a narrative poem of more than 200 verses by the Brazilian poet Vinicius de Moraes, following a construction worker from alienated labor to class consciousness.
Operários
Operários (Workers) is a 1933 oil painting by the Brazilian modernist Tarsila do Amaral, the principal work of her social phase, showing worker faces before São Paulo's factory chimneys.
Operating characteristic curve
An operating characteristic curve is a graph used in acceptance sampling that plots the probability of accepting a lot against its true quality, as the fraction defective.
Operating income
Operating income is the profit a company earns from its core business after deducting operating expenses such as cost of goods sold, wages, and depreciation, but before interest and taxes.
Operating lease
An operating lease is a lease in which the lessor keeps the risks and rewards of ownership, so the lessee returns the asset at the end of the term.
Operating leverage
Operating leverage is the amplification of sales changes into larger percentage changes in operating income (EBIT) that arises when a company's costs include fixed costs.
Operating system
An operating system is software that manages a computer's resources, arbitrating access to the CPU, memory, devices, and storage so programs run securely, portably, and efficiently.
Operating Tables
Operating tables (OT tables, operating room tables) are adjustable patient-support surfaces for surgery, built as tabletop, column, and transporter; stationary or mobile, radiolucent for C-arm imaging, governed by IEC 60601-2-46:2023.
Operating temperature
Operating temperature is the range of temperature within which a device is specified to function correctly. For electronics it may refer to ambient, case, or junction temperature.
Operating theater
Operating theater (operating room, OR): a hospital room for surgery in a sterile environment. Defined by aseptic technique, positive-pressure ventilation at about 15 ACH, zoning, team safety processes, and hybrid imaging variants.
Operating Thetan
Operating Thetan (OT) is a spiritual state in Scientology doctrine, above Clear, in which the thetan is said to be at cause over thought, life, matter, energy, space, and time.
Operation (game)
Operation (game): electronic dexterity board game invented by John Spinello in 1964, published by Milton Bradley in 1965; players tweeze 12 ailments from Cavity Sam without triggering the buzzer and light-up nose.
Operation (mathematics)
In mathematics, an operation is a function that takes a fixed number of elements of a set as inputs and returns one element of the same set.
Operation 1027
Operation 1027, launched 27 October 2023 by Myanmar's Three Brotherhood Alliance (MNDAA, TNLA, Arakan Army) in northern Shan State, was the anti-junta offensive that inflicted the Tatmadaw's worst defeats in decades, capturing Laukkaing and inspiring nationwide resistance offensives.
Operation 1111
Operation 1111 was a coordinated offensive launched on 11 November 2023 by Karenni resistance forces against Myanmar's military regime, taking seven towns though never capturing the capital Loikaw.
Operation Agreement
Operation Agreement was a failed British-led amphibious and commando raid on the Axis-held port of Tobruk, Libya, on 13 September 1942, costing several hundred men killed or captured and three warships.
Operation Anaconda
Operation Anaconda, 2-16 March 2002, Shah-i-Kot Valley, Afghanistan: largest U.S. ground battle of the early Afghan War, led by Maj. Gen. Hagenbeck against al-Qaeda; planned 72-hour encirclement became a two-week fight marked by air-ground coordination failures.
Operation Aphrodite
Operation Aphrodite was a secret 1944 US Army Air Forces program converting war-weary B-17 bombers into radio-controlled flying bombs; no drone ever destroyed its target.