the spread of a group of organisms into new habitats

(physics) the process in which incident radiated energy is retained without reflection or transmission on passing through a medium

the process of becoming acid or being converted into an acid

(thermodynamics) any process that occurs without gain or loss of heat

the process of exposing to air (so as to purify)

the process of preventing redeposition

any process in which an atomic or nuclear system acquires an additional particle

a process whereby a star or planet holds an object in its gravitational field

the process of separating substances of different densities by the use of a centrifuge

(chemistry) any process determined by the atomic and molecular composition and structure of the substances involved

a process used for separating mixtures by virtue of differences in absorbency

the formation of stonelike objects within a body organ (e.g., the kidneys)

the process of changing from a gaseous to a liquid or solid state

(meteorology) the vertical movement of heat or other properties by massive motion within the atmosphere

the process of forming semisolid lumps in a liquid

the process of gradually becoming inferior

the process of removing magnetization

changing from an adsorbed state on a surface to a gaseous or liquid state

(physics) the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration

separation into component parts

the process of purifying a liquid by boiling it and condensing its vapors

the gradual departure from an intended course due to external influences (as a ship or plane)

the process of bubbling as gas escapes

the motion of charged particles in a colloid under the influence of an electric field; particles with a positive charge go to the cathode and negative to the anode

(ecology) the process by which a plant or animal becomes established in a new habitat

the reduction of the intensity of radiation as a consequence of absorption and radiation

the process of obtaining something from a mixture or compound by chemical or physical or mechanical means

the process in which part of the output of a system is returned to its input in order to regulate its further output

the process whereby fluids pass through a filter or a filtering medium

the process of flocculating; forming woolly cloudlike aggregations

any uninterrupted stream or discharge

natural process that causes something to form

the process of fossilizing a plant or animal that existed in some earlier age; the process of being turned to stone

(geology) a natural process whereby geological features are modified

the process of becoming hard or solid by cooling or drying or crystallization

the process of rendering inactive

a process in which ions are exchanged between a solution and an insoluble (usually resinous) solid; widely used in industrial processing

the process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas

the process of leaching

the process that makes a substance magnetic (temporarily or permanently)

the process of coming into being; becoming reality

(physics) a process that alters the energy or structure or composition of atomic nuclei

the process of becoming cloudy or opaque

the process of oscillating between states

the process of providing or combining or treating with oxygen

the transformation of a gamma-ray photon into an electron and a positron when the photon passes close to an atomic nucleus

a change from one state (solid or liquid or gas) to another without a change in chemical composition

a slow westward shift of the equinoxes along the plane of the ecliptic caused by precession of the Earth's axis of rotation

a process that liberates or discharges something

(geology) the leaping movement of sand or soil particles as they are transported in a fluid medium over an uneven surface

the physical process in which particles are deflected haphazardly as a result of collisions

raising silkworms in order to obtain raw silk

(technology) a process that acts to absorb or remove energy or a substance from a system

the process of becoming softened and saturated as a consequence of being immersed in water (or other liquid)

the process of becoming softer

the process in which one substance takes up or holds another (by either absorption or adsorption)

(technology) a process by which energy or a substance enters a system

the process of becoming stiff or rigid

(physiology) the effect of a stimulus (on nerves or organs etc.)

(ecology) the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established

a natural process resulting in the evolution of organisms best adapted to the environment

the working together of two things (muscles or drugs for example) to produce an effect greater than the sum of their individual effects

a process whereby the degree of hotness of a body (or medium) changes

the process whereby a transducer accepts energy in one form and gives back related energy in a different form

the passage of gases through fine tubes because of differences in pressure or temperature

the process of becoming vitreous

a metal conductor specially designed to conduct (and radiate) heat

the development of many different forms from an originally homogeneous group of organisms as they fill different ecological niches

the flow of air that is driven backwards by an aircraft propeller

flow in which the velocity at any point varies erratically

flow of a gas or liquid in which the velocity at any point is relatively steady

(chemistry) a process in which one substance permeates another; a fluid permeates or is dissolved by a liquid or solid

stimulation of activity in an organism or chemical

the process of introducing an acyl group into a compound

the accumulation of molecules of a gas to form a thin film on the surface of a solid

(meteorology) the horizontal transfer of heat or other atmospheric properties

the coalescing of small particles that are suspended in solution; these larger masses are then (usually) precipitated

gradual formation of new land, by recession of the sea or deposit of sediment

conversion of starch to sugar

(chemistry) any process of combination (especially in solution) that depends on relatively weak chemical bonding

a process in which liquid blood is changed into a semisolid mass (a blood clot)

a process that makes something blue (or bluish)

a process that impregnates something with calcium (or calcium salts)

acceleration of a chemical reaction induced the presence of material that is chemically unchanged at the end of the reaction

soft decayed area in a tooth; progressive decay can lead to the death of a tooth

a self-sustaining nuclear reaction; a series of nuclear fissions in which neutrons released by splitting one atom leads to the splitting of others

the process of forming a ring by forming one or more hydrogen bonds

(chemistry) a process in which one or more substances are changed into others

the addition or substitution of chlorine in organic compounds

the breaking of a chemical bond in a molecule resulting in smaller molecules

a change in the world's climate

chromatography that uses selective adsorption by a column of powders

the process of congealing; solidification by (or as if by) freezing

the transfer of heat through a fluid (liquid or gas) caused by molecular motion

the process of becoming cooler; a falling temperature

erosion by chemical action

decay of matter (as by rot or oxidation)

the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)

removal of the amino radical from an amino acid or other amino compound

loss of calcium from bones or teeth

the process of removing a carboxyl group from a chemical compound (usually replacing it with hydrogen)

the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation

(pharmacology) the extraction of water-soluble drug substances by boiling

(biology) the process of decay caused by bacterial or fungal action

the process of making a (steel) ship's hull nonmagnetic by producing an opposing magnetic field

the process of extracting moisture

the removal of iodine atoms from organic compounds

the removal of minerals and mineral salts from a liquid (especially from water)

the removal of salt (especially from sea water)

the gradual transformation of habitable land into desert; is usually caused by climate change or by destructive use of the land

the process of deformation that produces continents and ocean basins in the earth's crust

the process of decomposing organic matter (as in sewage) by bacteria or by chemical action or heat

the process of becoming dilapidated

(chemistry) the temporary or reversible process in which a molecule or ion is broken down into smaller molecules or ions

the process of extracting one material from another by washing with a solvent to remove adsorbed material from an adsorbent (as in washing of loaded ion-exchange resins to remove captured ions); used to obtain uranium ions

the release of electrons from parent atoms

a nuclear reaction occurring with absorption of energy

(geology) the mechanical process of wearing or grinding something down (as by particles washing over it)

a nuclear reaction accompanied by the evolution of energy

a normal ongoing process that dissolves fibrin and results in the removal of small blood clots

flow into something (as a container)

a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy

gradual internal motion or deformation of a solid body (as by heat)

a geological process that causes a bend in a stratum of rock

the withdrawal of heat to change something from a liquid to a solid

a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy

stimulation with a galvanic current

the process of changing into gas

the process of interacting with gas

the process of covering the earth with glaciers or masses of ice

the process of becoming warmer; a rising temperature

a chemical process that adds hydrogen atoms to an unsaturated oil

electrophoresis to separate antigens and antibodies

the formation of a crust

the process of flowing in

the process of extracting certain active properties (as a drug from a plant) by steeping or soaking (usually in water)

the forcing of molten rock into fissures or between strata of an earlier rock formation

the increase in volume of certain substances when they are heated (often accompanied by release of water)

a chemical process in which the direction of optical rotation of a substance is reversed from dextrorotatory to levorotary or vice versa

the substitution or addition of iodine atoms in organic compounds

(of a ship or plane) sideways drift

(astronomy) a real or apparent slow oscillation of a moon or satellite

the conversion of a solid or a gas into a liquid

(biochemistry) dissolution or destruction of cells such as blood cells or bacteria

softening due to soaking or steeping

the atomic process that occurs during a chemical reaction

change in the structure of rock by natural agencies such as pressure or heat or introduction of new chemical substances

the transduction of sound waves into electrical waves (by a microphone)

crushing and separating ore into valuable substances or waste by any of a variety of techniques

feedback in opposite phase with (decreasing) the input

the chemical process in which a nitro group is added to an organic compound (or substituted for another group in an organic compound)

the process of mountain formation (especially by the upward displacement of the earth's crust)

(biology, chemistry) diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

the process of flowing out

chromatography that uses selective adsorption on a strip of paper

electrophoresis carried out on filter paper

the process of converting to a sol; bringing to a colloidal solution

the slow passage of a liquid through a filtering medium

the process of permeating or infusing something with a substance

the process of turning some plant material into stone by infiltration with water carrying mineral particles without changing the original shape

synthesis of compounds with the aid of radiant energy (especially in plants)

a chemical process that combines several monomers to form a polymer or polymeric compound

feedback in phase with (augmenting) the input

(medicine) the synergistic effect of two drugs given simultaneously

the process of forming a chemical precipitate

the hydrolysis of proteins into peptides and amino acids by cleavage of their peptide bonds

processes for chemical reactions at high temperatures

(photography) the formation of a network of cracks or wrinkles in a photographic emulsion

muscular stiffening that begins 2 to 4 hours after death and lasts for about 4 days

the action of forming a chelate or other stable compound with an ion or atom or molecule so that it is no longer available for reactions

the source of something's existence or from which it derives or is derived

(physics) a nuclear reaction in which a bombarded nucleus breaks up into many particles

the process of becoming spoiled

forming or depositing in layers

a geological process in which one edge of a crustal plate is forced sideways and downward into the mantle below another plate

the separation of liquid from a gel that is caused by contraction (as in cheese making)

the process of producing a chemical compound (usually by the union of simpler chemical compounds)

the process whereby heat changes something from a solid to a liquid

congealing tissue by heat (as by electric current)

the process of transfering an amino group from one compound to another

the process of transposing an amino group within a chemical compound

an exchange of molecules (and their kinetic energy and momentum) across the boundary between adjacent layers of a fluid or across cell membranes

centrifugation at very high speeds

the process of becoming a vapor

a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol

a method of extracting natural gas or oil from rock by injecting liquid at high pressure