S: (n) radiation (the spread of a group of organisms into new habitats)
S: (n) absorption ((physics) the process in which incident radiated energy is retained without reflection or transmission on passing through a medium) "the absorption of photons by atoms or molecules"
S: (n) acidification (the process of becoming acid or being converted into an acid)
S: (n) adiabatic process ((thermodynamics) any process that occurs without gain or loss of heat)
S: (n) aeration (the process of exposing to air (so as to purify)) "the aeration of the soil"
S: (n) desorption (changing from an adsorbed state on a surface to a gaseous or liquid state)
S: (n) diffusion ((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)
S: (n) establishment, ecesis ((ecology) the process by which a plant or animal becomes established in a new habitat)
S: (n) extinction (the reduction of the intensity of radiation as a consequence of absorption and radiation)
S: (n) extraction (the process of obtaining something from a mixture or compound by chemical or physical or mechanical means)
S: (n) feedback (the process in which part of the output of a system is returned to its input in order to regulate its further output)
S: (n) filtration (the process whereby fluids pass through a filter or a filtering medium)
S: (n) flocculation (the process of flocculating; forming woolly cloudlike aggregations)
S: (n) flow (any uninterrupted stream or discharge)
S: (n) formation (natural process that causes something to form) "the formation of gas in the intestine"; "the formation of crystals"; "the formation of pseudopods"
S: (n) fossilization, fossilisation (the process of fossilizing a plant or animal that existed in some earlier age; the process of being turned to stone)
S: (n) inactivation (the process of rendering inactive) "the gene inactivation system"; "thermal inactivation of serum samples"
S: (n) ion exchange (a process in which ions are exchanged between a solution and an insoluble (usually resinous) solid; widely used in industrial processing)
S: (n) ionization, ionisation (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)
S: (n) precession of the equinoxes (a slow westward shift of the equinoxes along the plane of the ecliptic caused by precession of the Earth's axis of rotation)
S: (n) release (a process that liberates or discharges something) "there was a sudden release of oxygen"; "the release of iodine from the thyroid gland"
S: (n) saltation ((geology) the leaping movement of sand or soil particles as they are transported in a fluid medium over an uneven surface)
S: (n) scattering (the physical process in which particles are deflected haphazardly as a result of collisions)
S: (n) sink ((technology) a process that acts to absorb or remove energy or a substance from a system) "the ocean is a sink for carbon dioxide"
S: (n) soak, soakage, soaking (the process of becoming softened and saturated as a consequence of being immersed in water (or other liquid)) "a good soak put life back in the wagon"
S: (n) softening (the process of becoming softer) "refrigeration delayed the softening of the fruit"; "he observed the softening of iron by heat"
S: (n) sorption (the process in which one substance takes up or holds another (by either absorption or adsorption))
S: (n) source ((technology) a process by which energy or a substance enters a system) "a heat source"; "a source of carbon dioxide"
S: (n) stimulation ((physiology) the effect of a stimulus (on nerves or organs etc.))
S: (n) succession, ecological succession ((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)
S: (n) synergy, synergism (the working together of two things (muscles or drugs for example) to produce an effect greater than the sum of their individual effects)
S: (n) transduction (the process whereby a transducer accepts energy in one form and gives back related energy in a different form) "the transduction of acoustic waves into voltages by a microphone"
S: (n) transpiration (the passage of gases through fine tubes because of differences in pressure or temperature)