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Refractive index
The refractive index (symbol n), also called index of refraction, is the ratio of light's speed in vacuum to its speed in a material, determining how much light bends.
Refractive index detection
Refractive index detection (RID) is a liquid-chromatography detection method comparing the refractive index of column effluent with the mobile phase, used mainly for carbohydrates and polymers.
Refractometer
A refractometer is an optical instrument that measures refractive index, most often via the critical angle, doubling as a concentration meter for sugar solutions, urine, and gems.
Refractometry
Refractometry is an optical measurement technique that determines the refractive index of liquids, solids, or gases, used in chemistry, pharmacy, and food industries to assess purity and concentration.
Refractory dissolved organic carbon
Refractory dissolved organic carbon, or rDOC, is the ocean's dissolved organic carbon that resists microbial degradation, persisting for millennia and totaling about 640 Pg C.
Refractory metals
Refractory metals, usually niobium, tantalum, molybdenum, tungsten, and rhenium, are metals with melting points above 2,000 °C and resistance to softening at high temperatures, though they oxidize poorly; tungsten melts at 3,422 °C.
Reg Watson
Reg A. Watson is an Australian fisheries and ecological modeling scientist at the University of Tasmania, known for mapping where the world's marine fisheries catch is taken.
Regenerated cellulose
Regenerated cellulose is cellulose dissolved from wood pulp and reformed into fibers or films, sold as rayon and lyocell; it was the first man-made fiber, named rayon in 1924.
Regenerative amplifier
A regenerative amplifier is an optical amplifier built as a laser cavity that traps a seed pulse, amplifies it over many round trips, and switches it out.
Regenerative process
A regenerative process is a stochastic process with random regeneration points at which it becomes a probabilistic replica of itself, producing independent, identically distributed cycles used in steady-state analysis.
Regenerative Rankine cycle
The regenerative Rankine cycle is a steam power cycle that preheats feedwater with steam extracted from the turbine, raising thermal efficiency while reducing specific work.
Regge calculus
Regge calculus is a formulation of general relativity, introduced by Tullio Regge in 1961, in which curved spacetime is approximated by a piecewise-flat lattice with curvature concentrated on triangles.
Regge theory
Regge theory describes high-energy scattering through Regge poles, moving singularities in the complex angular momentum plane, introduced by Tullio Regge and extended to particle physics by Chew, Frautschi, Gribov, and Pomeranchuk.
Regge–Wheeler equation
The Regge–Wheeler equation, derived by Tullio Regge and John Wheeler in 1957, is a Schrödinger-type wave equation governing odd-parity gravitational perturbations of the Schwarzschild black hole spacetime.
Reggeon
A reggeon is the exchange object associated with a Regge pole, a singularity of a scattering amplitude in the complex angular momentum plane, introduced by Tullio Regge in 1959.
Reginald Aldworth Daly
Reginald Aldworth Daly (1871–1957) was a Canadian-born American petrologist who spent most of his career at Harvard University and is best known for the theory of magmatic stoping.
Reginald E. Newell
Reginald E. Newell (1931–2002) was a British-born meteorologist who spent his career at MIT, studying climate system balances, global air pollution, and layered trace gases in the troposphere.
Reginald M. Penner
Reginald M. Penner, also published as Reginald Penner, is an American electrochemist at UC Irvine known for the LPNE nanowire fabrication method and nanowire sensors.
Reginald Victor Jones
Reginald Victor Jones was a British physicist who led scientific intelligence in World War II, countering German bomber beams and warning of the V-1 and V-2.
Regiomontanus
Regiomontanus, born Johann Müller of Königsberg, was a German astronomer and mathematician who completed the Epitome of the Almagest and founded the first printing house dedicated to scientific books.
Regional and national women-in-physics conferences
Regional and national women-in-physics conferences are recurring meetings giving women physics students role models, career information, and mentoring, including the American CUWiP series that began in 2006.
Regional climate model
A regional climate model (RCM) is a limited-area atmospheric model driven at its edges by a global climate model, downscaling coarse global projections into regional detail for climate studies.
Regional Greenhouse Gas Initiative
The Regional Greenhouse Gas Initiative (RGGI) is a cooperative cap-and-invest program of eleven U.S. states that caps and reduces carbon dioxide emissions from the electric power sector.
Regional impacts of climate change
Regional impacts of climate change are the effects of global warming on particular regions, which differ sharply, with the Arctic warming fastest and low-lying coasts hit hardest.
Regional metamorphism
Regional metamorphism is metamorphism affecting rocks over large areas of the crust, the most widespread type, occurring mainly where plates converge and mountain belts form.
Regional metrology organizations
Regional metrology organizations (RMOs) are regional associations of national metrology institutes defined within the CIPM Mutual Recognition Arrangement; six are recognized, including EURAMET, APMP, SIM, and COOMET.
Regional Ocean Modeling System
The Regional Ocean Modeling System (ROMS) is an open-source, three-dimensional ocean circulation model developed at Rutgers University and UCLA and used in NOAA coastal forecasts.
Regional physics conferences of Latin America, Asia–Pacific and Africa
Regional physics conference series gathering physicists by world region include SILAFAE, the triennial Asia–Pacific Physics Conference, and the biennial African Conference on Fundamental Physics and Applications.
Regioselectivity
Regioselectivity is the preferential formation of one constitutional isomer, or regioisomer, over others in a chemical reaction, seen classically in Markovnikov addition and ortho/para direction in aromatic substitution.
Register machine
A register machine is an abstract computing model, developed in the 1960s, whose registers hold non-negative integers; it is Turing equivalent and defines the same computable functions as Turing machines.