Science terms starting with C

1,236 terms

Coefficient of Heat Transmission (U-Value) A value that describes the ability of a material to conduct heat. The number of Btu that flow through 1 square foot of material, in one hour.
Coefficient of Performance (COP) A ratio of the work or useful energy output of a system versus the amount of work or energy inputted into the system as determined by using the same…
Coefficient of Utilization (CU) A term used for lighting appliances; the ratio of lumens received on a flat surface to the light output, in lumens, from a lamp; used to evaluate the…
Coenzyme (cofactor) An organic molecule, such as a vitamin, that binds to an enzyme and is required for its catalytic activity.
Cofactor See Coenzyme.
Coffer Dam A temporary structure enclosing all or part of a construction area so the construction can proceed in a dry area.
Cofferdam A temporary structure enclosing all or part of the construction area so that construction can proceed in the dry.
Cofiring The use of two or more different fuels (e.g. wood and coal) simultaneously in the same combustion chamber of a power plant.
Cogeneration The generation of electricity or shaft power by an energy conversion system and the concurrent use of rejected thermal energy from the conversion system…
Cogenerator A class of energy producer that produces both heat and electricity from a single fuel.
Coherent Radar A radar that utilizes both signal phase and amplitude to determine target characteristics.
Cohesion The mutual attraction of soil particles due to molecular and capillary forces in the presence of water.
Cohesionless materials (cohesionless soil) Soil materials that when unconfined have little or no strength when air-dried and that have little or no cohesion when submerged.
cohesive end See: extension.
Cohesive soil Predominantly clay and silt soil, fine-grained particles, that sticks together whether wet or dry.
COIL As a component of a heating or cooling appliance, rows of tubing or pipe with fins attached through which a heat transfer fluid is circulated and to…
coincidence The ratio of the observed to the expected frequency of double cross-overs, where the expected frequency is calculated by assuming that the two cross-over…
Coincidence Factor The ratio of the coincident, maximum demand or two or more loads to the sum of their noncoincident maximum demand for a given period; the reciprocal of…
Coincident Demand The demand of a consumer of electricity at the time of a power supplier's peak system demand.
Coisogenic or congenic Nearly identical strains of an organism; they vary at only a single locus.
colchicine An alkaloid, obtained from the autumn crocus Colchicum autumnale, which inhibits spindle formation.
Cold Advection Transport of cold air into a region by horizontal winds.
Cold Air Avalanche Downslope flow pulsations that occur at more or less regular intervals as cold air builds up on a peak or plateau, reaches a critical mass, and then…
Cold Air Dam A shallow cold air mass which is carried up the slope of a mountain barrier, but with insufficient strength to surmount the barrier.
Cold Air Damming (CAD) The phenomenon in which a low-level cold air mass is trapped topographically. Often, this cold air is entrenched on the east side of mountainous terrain.
Cold Air Funnel A funnel cloud or (rarely) a small, relatively weak tornado that can develop from a small shower or thunderstorm when the air aloft is unusually cold…
cold front A weather condition accompanied by high, clear skies, and a sudden drop in temperature.
Cold joint An unplanned joint resulting when a concrete surface hardens before the next batch is placed against it. Fresh concrete placed on harden concrete.
Cold low Cold low (or cold cyclone) At a given level in the atmosphere, any low that is generally characterized by colder air near its center than around its…
Cold Night Sky The low effective temperature of the sky on a clear night.
Cold Occlusion A frontal zone formed when a cold front overtakes a warm front and, being colder than the air ahead of the warm front, slides under the warm front…
Cold Pool A region of relatively cold air, represented on a weather map analysis as a relative minimum in temperature surrounded by closed isotherms.
Cold-water fishery Water or water system which has an environment suitable for salmonoid fishes.
coleoptile Protective sheath covering the shoot apex of the embryo in the grasses.
coleorhiza A protective sheath surrounding the radicle in the grasses.
Coliform Organisms common to the intestinal tract of humans and animals; the organisms' presence in waste water is an indicator of pollution.
Coliform bacteria Bacteria whose presence in waste water is an indicator of pollution and of potentially dangerous contamination.
collaborating program A program joining with the ARM Program to pursue a specific set of objectives by providing resources and participating in active planning and execution of…
Collar The open end of a drill hole.
Collar Cloud A generally circular ring of cloud that may be observed on rare occasions surrounding the upper part of a wall cloud.
Collaring Starting a drill hole. When the hole is deep enough to hold the bit from slipping out of it, it is said to be collared.
Collateral Assets that are offered to secure a loan or other credit. For example, if you get a real estate mortgage, the bank's collateral is typically your house.
Collection The capture or obtaining of plant or animal specimens. This can include obtaining specimens for scientific study, pets, or illegal trade.
Collection Efficiency The fraction of droplets approaching a surface that actually deposit on that surface.
Collector The component of a solar energy heating system that collects solar radiation, and that contains components to absorb solar radiation and transfer the heat…
Collector Efficiency The ratio of solar radiation captured and transferred to the collector (heat transfer) fluid.
Collector Fluid The fluid, liquid (water or water/antifreeze solution) or air, used to absorb solar energy and transfer it for direct use, indirect heating of interior…
Collector Tilt The angle that a solar collector is positioned from horizontal.
collenchyma A tissue of living cells, found particularly in midribs and leaf petioles. Characterized by cell walls unevenly thickened with cellulose and…
Colloidal particles Soil particles that are so small that the surface activity has an appreciable influence on the properties of the aggregate. Particles smaller than 0.
Colloidal suspension A method of sediment transport in which water turbulence (movement) supports the weight of the sediment particles, thereby keeping them from settling out…
Colluvium A general term to include loose rock and soil material that accumulates at the base of a slope as the result of mass wasting processes.
Colony A group of identical cells (clones) derived from a single progenitor cell.
colony hybridization A technique that uses a nucleic acid probe to identify a recombinant bacterial colony carrying a particular inserted DNA.
Colony-forming cells Groups of cells growing on a solid nutrient surface with each group being created from the multiplication of an individual cell.
Colony-stimulating factors Diffusible proteins that stimulate the proliferation of hematopoietic stem cells.
Color The sensible perception of hue, value and saturation characteristics of surfaces of window components.
Color Rendition How colors appear when illuminated by a light source. Color rendition is generally considered to be a more important lighting quality than color…
Color Rendition (Rendering) Index (CRI) A measure of light quality. The maximum CRI value of 100 is given to natural daylight and incandescent lighting.
Color Temperature The color of the light source. By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an…
Colorado Low A low pressure storm system that forms in winter in southeastern Colorado or northeastern New Mexico and tracks northeastward across the central plains of…
Columnar Ice Ice consisting of columnar shaped grain. The ordinary black ice is usually columnar-grained.
combinatorial library The many novel combinations (consisting of one heavy and one light immunoglobulin chain coding region) that are generated when a heavy-chain library is…
Combined cycle Two or more generation processes in series or in parallel, configured to optimize the energy output of the system.
Combined cycle plant A plant which achieves higher efficiency by employing two cycles in tandem. For example, heat rejected from a gas-fired turbine is used to generate steam…
Combined Heat and Power (CHP) Also called cogeneration, CHP is the use of the waste heat generated by an engine or power station to produce useful heat, typically for heating of a…
Combined Seas Combination of both wind waves and swell. Also called "Seas" and is approximately equal to significant wave height.
Combined-cycle generators See Combined-cycle Power Plant.
Combined-cycle power plant A power plant that uses two thermodynamic cycles to achieve higher overall system efficiency; e.g.
combining site See: antibody binding site.
Combustion The process of burning; the oxidation of a material by applying heat, which unites oxygen with a material or fuel.
Combustion Air Air that provides the necessary oxygen for complete, clean combustion and maximum heating value.
Combustion Chamber Any wholly or partially enclosed space in which combustion takes place.
Combustion efficiency The actual heat produced by combustion divided by the total heat potential of the fuel consumed.
Combustion Gases The gaseous byproducts of the combustion of a fuel.
Combustion Power Plant A power plant that generates power by combusting a fuel.
Combustion turbine A turbine that generates power from the combustion of a fuel.
Comfort Zone A 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 Cloud A synoptic scale cloud pattern with a characteristic comma-like shape, often seen on satellite photographs associated with large and intense low-pressure…
Comma Echo A thunderstorm radar echo which has a comma-like shape. It often appears during latter stages in the life cycle of a bow echo
Commensalism The close association of two or more dissimilar organisms where the association is advantageous to one and doesn't affect the other(s).
Commercial Building A building with more than 50 percent of its floor space used for commercial activities, which include stores, offices, schools, churches, libraries…
Commercial forest land Forested 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 operation Commercial operation begins when control of the loading of the generator is turned over to the system dispatcher.
Commercial river trip Trips organized by boating companies that conduct tours for paying passengers or customers.
Commercial Sector Consists of businesses that are not engaged in transportation or manufacturing or other types of industrial activities.
Commercial user day Amount of commercial use within a 24-hour period or any portion thereof.
Commercial water use Water for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions.
Commissioning The process by which a power plant, apparatus, or building is approved for operation based on observed or measured operation that meets design…
Common excavation All 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 material All earth materials which do not fall under the definition of rock.
Community A political entity that has the authority to adopt and enforce floodplain ordinances for the area under its jurisdiction.
Community cohesion Ability of a community to have a unified response when facing a problem; e.g., an external threat to their sustainability.
compact An agreement between states apportioning the water of a river basin to each of the signatory states.
Compact Building Design Refers to the act of constructing buildings vertically rather than horizontally, and configuring them on a block or neighborhood scale that makes…
Compact Fluorescent A smaller version of standard fluorescent lamps which can directly replace standard incandescent lights.
Compact Linear Fresnel Reflector (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 backfill Backfill which has been reduced to bulk by rolling, tamping, or soaking.
Compacted embankment Embankment which has been reduced in bulk by rolling, tapping, or soaking.
Compaction To make soil dense by mechanical manipulation. Mechanical action which increases the density by reducing the voids in a material.