hydro-, hydra-, hydr-, hyd-
2. The elastic interaction between a body and the fluid in which it is immersed.
2. The generation of electricity by using the motive power of water.
3. Relating to or producing electricity by the force of fast moving water; such as, rivers or waterfalls.
In many countries, hydroelectricity is the primary source of electrical power.
2. A device consisting of a flat or curved piece (as a metal plate) so that its surface reacts to the water it is passing through: "The fins of a fish act as hydrofoils."
3. A boat equipped with hydrofoils.
2. Shedding water, as with the hair of certain animals.
3. Describing the water-repellent hairs of certain aquatic insects; used for retaining a film of air.
2. A colloidal gel in which water is the dispersion medium.
Hydrogel is a network of polymer chains that are water-soluble, sometimes found as a colloidal gel in which water is the dispersion medium. Hydrogels are superabsorbent (they can contain over 99% water) natural or synthetic polymers.
Some uses for hydrogel include: disposable diapers that "capture" urine, or in sanitary towels, and for use with contact lenses (silicone hydrogels, polyacrylamides).
2. A colorless, highly flammable gaseous element, the lightest of all gases and the most abundant element in the universe, used in the production of synthetic ammonia and methanol, in petroleum refining, in the hydrogenation of organic materials, as a reducing atmosphere, in oxyhydrogen torches, and in rocket fuels.
3. From 1791, French hydrogène, coined in 1787 by G. de Morveau from Greek hydr-, stem of hydros, "water" + French -gène, "producing". So called because it forms water when exposed to oxygen.
Source: water, most organic compounds. Use: industrial processes, production of ammonia, reduction of metal ores to metals.
Hydrogeology is also concerned with the physical, chemical, and biological features of groundwater.
2. A graph showing the variation of level, speed of flow, or another quantity at some point on a river.