All articles starting with Q
2,252 articles
Quarto
Quarto (board game), also called 4x4, is a 1991 two-player abstract strategy game by Blaise Müller, published by Gigamic: 16 shared pieces on a 4x4 board, opponent picks your piece, four-in-a-row by shared attribute wins; solved as a draw.
Quartu S. Elena
Quartu S. Elena (Quartu Sant'Elena), a large town in the metropolitan city of Cagliari, Sardinia, four Roman miles from Caralis, with 38 nuraghi, the Nuraghe Diana, and the partially submerged Roman maritime villa of Sant'Andrea (2nd-4th century AD).
Quartus
Quartus, currently Quartus Prime, is the integrated development environment from Altera, the FPGA company spun out of Intel, for designing and programming its FPGAs, SoCs, and CPLDs.
Quartz
Quartz, also known as rock crystal, is a crystalline mineral of silicon dioxide, abundant in igneous, metamorphic, and sedimentary rocks, famous for its purple amethyst variety.
Quartz accelerometer
A quartz accelerometer is a pendulous force-rebalance accelerometer machined from a single piece of fused quartz; Honeywell's Q-Flex line is the de facto industry standard for navigation-grade inertial navigation.
Quartz clock
A quartz clock keeps time using the vibration of a piezoelectric quartz crystal, replaced pendulums as national standards in 1929, and now times billions of wristwatches.
Quartz crisis
The quartz crisis, also called the quartz revolution, was the collapse of the Swiss watch industry in the 1970s under competition from cheap quartz watches.
Quartz crystal microbalance with dissipation
Quartz crystal microbalance with dissipation (QCM-D) is a surface-sensitive acoustic technique that measures frequency and dissipation shifts to study adsorption and viscoelastic properties of polymer, biomolecular, and cell layers.
Quartz Mountain (solar farm)
Quartz Mountain is the name of a solar farm with no verifiable record; the nearest namesake is the 120 MW North Fork plant near Quartz Mountain State Park in Hobart, Oklahoma.
Quartz sand
Quartz sand, also called silica sand, is sand dominated by quartz (SiO2), 0.06–2 mm grains, Mohs 7. Used in glass, foundries, fracking, and, as high-purity quartz (99.99%+), semiconductors; Spruce Pine, North Carolina is the key HPQ source.
Quartzite
Quartzite, also known as metaquartzite, is a hard, quartz-rich metamorphic rock formed when sandstone or chert recrystallizes under regional or thermal metamorphism; the name also covers some well-cemented sandstone.
Quarup
Quarup is a 1967 novel by the Brazilian writer Antônio Callado, tracing a young priest's journey from the Xingu region into the armed struggle against the military dictatorship.
Quasar
A quasar, short for quasi-stellar radio source, is an extremely luminous galactic center powered by a supermassive black hole consuming gas, outshining its host galaxy.
Quasar clustering
Quasar clustering is the statistical excess of quasar pairs at given separations, measured to show how these active supermassive black holes trace the large-scale structure of the universe.
Quasar Hubble diagram
The quasar Hubble diagram is a plot of distance against redshift for quasars, using their UV and X-ray luminosity relation to test cosmology at redshifts beyond Type Ia supernovae.
Quasar luminosity function
The quasar luminosity function is the comoving number density of quasars per unit luminosity, whose evolution with redshift traces the history of accretion onto supermassive black holes.
Quasar quartet
The quasar quartet is the first known system of four quasars in close proximity, discovered in 2015 with the Keck I Telescope in Hawaii and announced in Science.
Quasi-Biennial Oscillation
The quasi-biennial oscillation (QBO) is a quasi-periodic reversal of equatorial stratospheric winds averaging about 28 months, first detected in 1960 and among the most predictable atmospheric cycles.
Quasi-contract
Quasi-contract, or contract implied in law, is a court-imposed obligation preventing unjust enrichment without any agreement. Covers Roman quasi ex contractu roots, the 1937 and Third Restatements, civil law negotiorum gestio, and comparative Islamic approaches.
Quasi-delict
Quasi-delict: a wrongful act giving rise to compensation obligations, from Roman obligations quasi ex delicto in Justinian's Institutes; survives in Philippine Civil Code Article 2176 and EU private international law, distinct from deliberate delict and common-law tort.
Quasi-direct drive
Quasi-direct drive is a robot actuation approach pairing a high-torque motor with a low gear ratio for backdrivability, now the dominant architecture in commercial humanoid and quadruped robots.
Quasi-elastic neutron scattering
Quasi-elastic neutron scattering (QENS) is a neutron spectroscopy technique that measures broadening of the elastic line from stochastic diffusive motions, revealing diffusion coefficients and molecular motion geometry.
Quasi-experiment
A quasi-experiment, also called a quasi-experimental design, is a study design for estimating causal effects without random assignment, using repeated measurements or a comparison group instead.
Quasi-Fermi level
A quasi-Fermi level, also called Imref, is a fictitious Fermi level assigned separately to electrons and holes in a semiconductor under illumination or bias, where equilibrium is broken.
Quasi-fission
Quasi-fission is a fission-like outcome of a heavy-ion collision in which two touching nuclei re-separate before forming an equilibrated compound nucleus, strongly suppressing superheavy element synthesis.
Quasi-geostrophic theory
Quasi-geostrophic (QG) theory is a simplified system of equations for large-scale midlatitude atmospheric and oceanic flow, developed mainly by J. G. Charney in the late 1940s and still central to weather forecasting.
Quasi-harmonic approximation
The quasi-harmonic approximation (QHA) is a lattice dynamics method that treats a crystal as harmonic at each volume, letting phonon frequencies vary with volume to obtain thermal expansion and heat capacity.
Quasi-isodynamic stellarator
A quasi-isodynamic stellarator is a type of optimized stellarator, a magnetic-confinement fusion device that minimizes heat losses and produces zero bootstrap current, tested by Wendelstein 7-X and favored in recent reactor concepts like Stellaris.
Quasi-isometry
A quasi-isometry is a map between metric spaces that preserves distances up to a multiplicative factor and additive constant, the central notion of geometric group theory.
Quasi-judicial body
A quasi-judicial body is a non-court government organ exercising court-like functions: hearings, evidence, and decisions affecting rights, subject to judicial review. Examples include administrative tribunals, regulatory commissions, and UN treaty bodies, with the ICC and Humphrey's Executor as landmarks.