Range FoldingThis occurs when the radar receives a signal return from a pulse other than the most recent pulse.
Range GateThe discrete point in range along a single radial of radar data at which the received signal is sampled.
Range Height IndicatorThe RHI is a radar display in which the radar scans vertically, with the antenna pointing at a specific azimuth or radial.
Range NormalizationA receiver gain function in the radar which compensates for the effect of range (distance) on the received power for an equivalent reflectivity.
Range ResolutionThe ability of the radar to distinguish two targets along the same radial but at different ranges. it is approximately ½ the pulse length.
Range UnfoldingProcess of removing range ambiguity in apparent range of a multitrip target on the radar.
RangelandLand on which the native vegetation, climax, or natural potential consists predominately of grasses, grasslike plants, forbs, or shrubs.
Rankine CycleThe thermodynamic cycle that is an ideal standard for comparing performance of heat-engines, steam power plants, steam turbines, and heat pump systems…
Rankine steam cycleThe thermodynamic cycle of temperature and pressure changes of water as it is converted from a liquid to a gaseous state by heating, and returns back to…
Rankine VortexVelocity profile for a symmetric circulation in which the inner core is in solid rotation and tangential winds outside the core vary inversely with radial…
RAPDAbbreviation for random amplified polymorphic DNA.
RapidA section of a river where the current is very fast moving, caused by a steep descent in the riverbed through a constriction of the main channel.
Rapid DeepeningA decrease in the minimum sea-level pressure of a tropical cyclone of 1.75 mb/hr or 42 mb for 24 hours
Rapid flowAlso refered to as supercritical flow, rapid flow is distinguished from tranquil flow by a dimensionless number called the Froude number.
Rapid IntensificationAn increase in the maximum sustained winds of a tropical cyclone of at least 30 kt in a 24-h period.
Rapidly IntensifyingIndicator for a maritime cyclone whose central pressure is dropping, or is expected to drop, at a rate of 1 MB per hour for 24 hours.
RAPTORA bird of prey such as a falcon, hawk, or eagle.
Rate meterAn electronic instrument that indicates, on a meter, the number of radiation induced pulses per minute from radiation detectors such as a Geiger-Muller…
Rate ScheduleA mechanism used by electric utilities to determine prices for electricity; typically defines rates according to amounts of power demanded/consumed during…
rate-limiting enzymeThe enzyme whose activity controls the output of final product from a multi-enzyme metabolic pathway.
Rated battery capacityThe term used by battery manufacturers to indicate the maximum amount of energy that can be withdrawn from a battery under specified discharge rate and…
Rated capacityThat capacity which a hydrogenerator can deliver without exceeding mechanical safety factors or a nominal temperature rise.
Rated headWater depth for which a hydroelectric generator and turbines were designed.
Rated LifeThe length of time that a product or appliance is expected to meet a certain level of performance under nominal operating conditions; in a luminaire, the…
Rated PowerThe power output of a device under specific or nominal operating conditions.
Rating CurveA graph showing the relationship between the stage, usually plotted vertically (Y-axis) and the discharge, usually plotted horizontally (X-axis).
Rating TableA table of stage values and the corresponding discharge for a river gaging site.
Ratio of reductionThe relationship between the maximum size of the stone which will enter a crusher, and the size of its product.
rational drug designA systematic method of creating compounds by analysing their structure, function and stereochemical interactions.
RawinsondeA radiosonde that is tracked to measure winds.
Rayleigh Frequency DistributionA mathematical representation of the frequency or ratio that specific wind speeds occur within a specified time interval.
Rayleigh ScatteringChanges in directions of electromagnetic energy by particles whose diameters are 1/16 wavelength or less.
ReachAny specified length of stream, channel, or other water conveyance. A portion of a stream or a river.
reactionA chemical reaction is a dissociation, recombination, or rearrangement of atoms.
Reactive PowerThe electrical power that oscillates between the magnetic field of an inductor and the electrical field of a capacitor.
read-throughTranscription or translation that proceeds beyond the normal stopping point because of the absence of the usual transcription or translation termination…
Reading frameA series of triplet codons beginning from a specific nucleotide. Depending on where one begins, each DNA strand contains three different reading frames.
Ready reserveGeneration capacity that can be synchronized and ready to serve load in a short time period, usually 10 minutes or less.
Real PriceThe unit price of a good or service estimated from some base year in order to provide a consistent means of comparison.
Real TimeWhen an event is reported as it happens - such as a quick jump in a stock's price or the constantly changing numbers on a market index - you are getting…
Real-time marketAn electricity market that settles–determines the price–for one-hour periods or less during the day of delivery.
Real-time pricingThe instantaneous pricing of electricity based on the cost of the electricity available for use at the time the electricity is demanded by the customer.
Rear Flank DowndraftA region of dry air subsiding on the back side of, and wrapping around, a mesocyclone. It often is visible as a clear slot wrapping around the wall cloud.
Reattachment depositSand deposit located where downstream flow meets the channel bank at the downstream end of a recirculating zone.
Rebound (of water levels)The recovery/rise of the water level in a groundwater aquifer after groundwater pumping has ceased.
recAA protein, found in most bacteria, that is essential for DNA repair and DNA recombination.
recalcitrantOf seeds, unable to survive drying and subsequent storage at low temperature. See: field gene bank.
RecedeTo move away from the observer, which is, in most cosmological instances, the earth.
ReceiverThe component of a central receiver solar thermal system where reflected solar energy is absorbed and converted to thermal energy.
Receiving DistrictAn overlay zoning district established by the Town Meeting/ Town Council upon recommendation from the Planning Board as an area suitable to receive…
receptacleEnlarged end of the pedicel or peduncle, to which other flower parts are attached.
receptor(reh-SEP-ter) A molecule inside or on the surface of a cell that binds to a specific substance and causes a specific physiologic effect in the cell.
receptor-binding screeningA biotechnology-based method for drug discovery, which relies on the fact that many drugs act by binding to specific receptors on or in cells.
Recession ConstantConstant used to reduce the API value daily in the API method of estimating runoff.
recessiveDescribing an allele whose effect with respect to a particular trait is not evident in heterozygotes. Opposite: dominant.
recessive alleleAllelic state of a gene, where homozygosity is required for the expression of the relevant phenotype. Opposite:.
Recessive geneCharacterized as having a phenotype expressed only when both copies of the gene are mutated or missing.
recessive oncogeneA single copy of this gene is sufficient to suppress cell proliferation; the loss of both copies of the gene contributes to cancer formation.
Recessive(-acting) oncogene, (anti-oncogene)A single copy of this gene is sufficient to suppress cell proliferation; the loss of both copies of the gene contributes to cancer formation.
RechargeWater that infiltrates into the ground, usually from above, that replenishes groundwater reserves, provides soil moisture, and affords evapotranspiration.
Recharge rateThe quantity of water per unit time that replenishes or refills an aquifer.
Reciprocal translocationWhen a pair of chromosomes exchange exactly the same length and area of DNA. Results in a shuffling of genes.
reciprocating shakerA platform shaker used for agitating culture flasks, with a back and forth action at variable speeds.
Recirculated AirAir that is returned from a heated or cooled space, reconditioned and/or cleaned, and returned to the space.
RecirculationReturning a fraction of the effluent outflow to the inlet to dilute incoming wastewater.
Recirculation SystemsA type of solar heating system that circulate warm water from storage through the collectors and exposed piping whenever freezing conditions occur…
Recirculation zoneArea of flow composed of one or more eddies immediately downstream from a constriction in the channel, such as a debris fan or rock outcrop.
ReclamationThe process of restoring surface environment to acceptable pre-existing conditions.
Reclamation Reform Act of 1982 (RRA)The Reclamation Reform Act of 1982 limits the amount of owned land that is eligible to receive project (Reclamation) irrigation water and addresses the…
Reclamation withdrawalWithholding an area of public land from the operation of the public land laws for the purpose of reserving the land for the use of the Bureau of…
Recognition sequence (site)A nucleotide sequence--composed typically of 4, 6, or 8 nucleotides--that is recognized by a restriction endonuclease.
recognition siteA nucleotide sequence, typically 4-8bp long and often palindromic, that is recognized by, and at which a restriction endonuclease binds to the DNA.
recombinant(ree-KOM-bih-nunt) In genetics, describes DNA, proteins, cells, or organisms that are made by combining genetic material from two different sources.
Recombinant cloneClone containing recombinant DNA molecules. See also: recombinant DNA technology
recombinant DNAThe process of cutting and recombining DNA fragments from different sources as a means to isolate genes or to alter their structure and function.
Recombinant DNA moleculesA combination of DNA molecules of different origin that are joined using recombinant DNA technologies.
Recombinant DNA molecules (rDNA)A combination of DNA molecules of different origin that are joined using recombinant DNA technologies.
Recombinant DNA technologyA set of techniques for manipulating DNA, including: the identification and cloning of genes; the study of the expression of cloned genes; and the…
recombinant human(Abbreviation rh). A prefix denoting molecules made through the use of recombinant DNA technology.
recombinant proteinA protein encoded by a cloned gene. Synonym: heterologous protein.
recombinant RNARNA molecules joined in vitro by T4 RNA ligase.
recombinant toxinA single multifunctional toxic protein encoded by a recombinant gene.