Combustion turbineA turbine that generates power from the combustion of a fuel.
Comfort ZoneA frequently used room or area that is maintained at a more comfortable level than the rest of the house; also known as a "warm room."
Comma CloudA synoptic scale cloud pattern with a characteristic comma-like shape, often seen on satellite photographs associated with large and intense low-pressure…
Comma EchoA thunderstorm radar echo which has a comma-like shape. It often appears during latter stages in the life cycle of a bow echo
CommensalismThe close association of two or more dissimilar organisms where the association is advantageous to one and doesn't affect the other(s).
Commercial BuildingA building with more than 50 percent of its floor space used for commercial activities, which include stores, offices, schools, churches, libraries…
Commercial forest landForested land which is capable of producing new growth at a minimum rate of 20 cubic feet per acre per year, excluding lands withdrawn from timber…
Commercial operationCommercial operation begins when control of the loading of the generator is turned over to the system dispatcher.
Commercial river tripTrips organized by boating companies that conduct tours for paying passengers or customers.
Commercial SectorConsists of businesses that are not engaged in transportation or manufacturing or other types of industrial activities.
Commercial user dayAmount of commercial use within a 24-hour period or any portion thereof.
Commercial water useWater for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions.
CommissioningThe process by which a power plant, apparatus, or building is approved for operation based on observed or measured operation that meets design…
Common excavationAll materials excavated not considered as rock. Boulders or detached pieces of solid rock less than 1 cubic yard in volume are classified as common…
Common materialAll earth materials which do not fall under the definition of rock.
CommunityA political entity that has the authority to adopt and enforce floodplain ordinances for the area under its jurisdiction.
Community cohesionAbility of a community to have a unified response when facing a problem; e.g., an external threat to their sustainability.
compactAn agreement between states apportioning the water of a river basin to each of the signatory states.
Compact Building DesignRefers to the act of constructing buildings vertically rather than horizontally, and configuring them on a block or neighborhood scale that makes…
Compact FluorescentA smaller version of standard fluorescent lamps which can directly replace standard incandescent lights.
Compact Linear Fresnel Reflector (CLFR)(CLFR)A type of concentrated solar power (CSP) technology similar to a parabolic trough design, where the sun's heat energy is reflected onto a receiver…
Compacted backfillBackfill which has been reduced to bulk by rolling, tamping, or soaking.
Compacted embankmentEmbankment which has been reduced in bulk by rolling, tapping, or soaking.
CompactionTo make soil dense by mechanical manipulation. Mechanical action which increases the density by reducing the voids in a material.
Compaction testA laboratory compacting procedure whereby a soil at a known moisture content is placed in a specified manner into a mold of given dimensions, subjected to…
companion cellA living cell associated with the sieve cell of phloem tissue in vascular plants.
Comparative genomicsThe study of human genetics by comparisons with model organisms such as mice, the fruit fly, and the bacterium E. coli.
comparative mappingThe comparison of map locations of genes and markers between species. In comparisons between closely related species, this will usually uncover a high…
comparative positional candidate geneRelates to an indirect means of assigning function to a QTL. Where a QTL has been linked to a marker in one species, and that same marker is linked to a…
CompensationA type of mitigation in which the impacts to a species or habitat are offset by protecting, restoring, or creating suitable habitat elsewhere.
Compensatory mitigation(For purposes of the Clean Water Act Section 404 and Rivers and Harbors Act Section 10 regulatory programs), compensatory mitigation is the restoration…
CompetencyAn ephemeral state, induced by treatment with cold cations, during which bacterial cells are capable of uptaking foreign DNA.
competent1. Bacterial cells able to take up foreign DNA molecules and thereby become genetically transformed.
complement proteins Proteins that bind to antibody -antigen complexes and help degrade the complexes by proteolysis.
complementarity1. See: complementary. 2. The similar correspondence between DNA and the mRNA transcribed from it.
complementarity-determining regions(Abbreviation: CDR). Regions of the light and heavy subunits of the immunoglobulin molecules that interact with the antigen.
complementaryTwo DNA molecules are complementary to one another when each successive base position from the 5' end in the first molecule is matched by the…
complementary DNA(Abbreviation: cDNA ). A DNA strand synthesized in vitro from a mature RNA template using reverse transcriptase.
Complementary DNA (cDNA)DNA that is synthesized in the laboratory from a messenger RNA template.
Complementary DNA or RNAThe matching strand of a DNA or RNA molecule to which its bases pair. (See DNA, RNA.)
complementary entity1. Synonym of base pair. 2. One of a pair of segments or strands of nucleic acid that will hybridize with one another.
complementary genesTwo or more interdependent genes, such that (in the case of dominant complementarity) the dominant allele from either gene can only produce an effect on…
Complementary nucleotidesMembers of the pairs adenine-thymine, adenine-uracil, and guaninecytosine that have the ability to hydrogen bond to one another. (See nucleotide.)
Complementary sequenceNucleic acid base sequence that can form a double-stranded structure with another DNA fragment by following base-pairing rules (A pairs with T and C with…
complementation testA genetic method to test whether or not independent mutations are allelic. In a cross between the two mutant individuals, the genotype will be m1m2 if the…
complete digestThe treatment of a DNA preparation with a restriction endonuclease for sufficient time for all of the potential target sites within that DNA to have been…
Complete Mix DigesterA type of anaerobic digester that has a mechanical mixing system and where temperature and volume are controlled to maximize the anaerobic digestion…
Complex Gale/StormIn the high seas and offshore forecasts, an area for which gale/storm force winds are forecast or are occurring but for which no single center is the…
Complex TerrainTypically used to refer to mountainous terrain. In general usage, it may also refer to coastal regions and heterogeneous landscapes.
Complex traitTrait that has a genetic component that does not follow strict Mendelian inheritance.
CompositeAn average that is calculated according to specific criteria. For example, one might want a composite for the rainfall at a given location for all years…
Composite HydrographA stream discharge hydrograph which includes base flow, or one which corresponds to a net rain storm of duration longer than one unit period.
Composite noise levelA single noise level summed on an energy basis from many noise sources (e.g., Stirling engine, electric generator, cooling fan, and air compressor for a…
Composite power valueThe value of power including both a capacity and energy component, usually expressed in mills per kilowatt-hour.
composite transposonA transposon formed when two identical or nearly identical transposons insert on either side of a non-transposable segment of DNA.
CompostPartially decomposed organic plant and animal matter that can be used as a soil conditioner or fertilizer. See decomposition.
CompostingThe process of degrading organic material (biomass) by microorganisms in aerobic conditions.
Composting ToiletA self-contained toilet that use the process of aerobic decomposition (composting) to break down feces into humus and odorless gases.
Compound(KOM-pownd) In science, a substance that is made up of more than one ingredient.
compound chromosomeA chromosome formed by the fusion of two separate chromosomes, as in attached-X chromosomes or attached-X-Y chromosomes.
Comprehensive Facility Review (CFR)A review performed on a high- or significant-hazard dam every 6 years, which includes a field examination and a state-of-the-art review of a structure's…
Comprehensive PlanRegional, state, or local documents that describe community visions for future growth.
Compressed Air StorageThe storage of compressed air in a container for use to operate a prime mover for electricity generation.
Compressed Natural Gas (CNG)(CNG)Natural gas (methane) that has been compressed to a higher pressure gaseous state by a compressor; used in CNG vehicles.
CompressibilityProperty of a soil describing its susceptibility to decrease in volume when subjected to load.
CompressionCompression algorithms such as Zip and RLE reduce the size of files saving both storage space and reducing bandwidth required for access and transmission.
Compression ChillerA cooling device that uses mechanical energy to produce chilled water.
Compression curveAny function relating volume change to effective stress.
CompressorA device used to compress air for mechanical or electrical power production, and in air conditioners, heat pumps, and refrigerators to pressurize the…
Computer base stationComputer equipment that is designated to receive data from the data collection platforms and translate that data into useable information for the decision…
ConcatemerA DNA segment composed of repeated sequences linked end to end.
Concentrated flow pathAn existing hypothetical avenue of concentrated seepage. The descriptor "concentrated" implies sufficient energy to carry/move material and erode.
Concentrating (Solar) CollectorA solar collector that uses reflective surfaces to concentrate sunlight onto a small area, where it is absorbed and converted to heat or, in the case of…
Concentrating solar power (CSP) technologies(CSP)Any of a family of solar energy technologies that reflect and concentrate the sun's energy to produce heat that is subsequently used to produce steam to…
ConcentrationAmount of a chemical in a particular volume or weight of air, water, soil, or other medium.
ConcentratorA photovoltaic module, which includes optical components such as lenses (Fresnel lens) to direct and concentrate sunlight onto a solar cell.
Concentric RingsThese are common in the most intense hurricanes. They usually mark the end the period of intensification.
concordanceIdentity of matched pairs or groups for a given trait, such as sibs expressing the same trait.
Concrete damSee arch dam, buttress dam, or gravity dam. See also masonry dam. A concrete dam generally requires a sound rock foundation.
Concrete liftIn concrete work, the vertical distance between successive horizontal construction joints.
ConcussionShock or sharp air waves caused by an explosion or heavy blow.
CondensateThe liquid resulting when water vapor contacts a cool surface; also the liquid resulting when a vaporized working fluid (such as a refrigerant) is cooled…
CondensationThe process by which water in air changes from a vapor to a liquid due to a change in temperature or pressure; occurs when water vapor reaches its dew…
Condensation FunnelA funnel-shaped cloud associated with rotation and consisting of condensed water droplets (as opposed to smoke, dust, debris, etc.).