AEROSOLS |
|
Aerosol spray is the name given to a type of canister containing liquid under pressure from pressurized vapor in equilibrium with another liquid, which often also dissolves the payload (see propellant below). When the can's valve is opened, the liquid is forced out of a small hole and emerges as an aerosol, or mist. As gas expands to drive out the payload, some propellant evaporates inside the can to maintain an even pressure. Outside the can, the droplets of propellant evaporate rapidly, leaving the payload suspended as very fine particles or droplets. Typical liquids dispensed in this way are insecticides, deodorants and paints. An atomiser is a similar device that is pressurised by a hand-operated pump rather than by stored gas.
|
HYDROLOGY |
|
Hydrology (from Greek: Yδρoλoγια, Yδωρ+Λoγos, Hydrologia, the "study of water") is the study of the movement, distribution, and quality of water throughout the Earth, and thus addresses both the hydrologic cycle and water resources. A practitioner of hydrology is a hydrologist, working within the fields of either earth or environmental science, or civil and environmental engineering.
|
|
