HYDROPONICS (from gidro... And grech. ponos - activity), a propagation (vegetable, flower, berrylike, etc.) without soil. Roots become stronger in gravel, a moss, sand and the other solid substrate (where water with dissolved nutrients in her files), are dipped in a nutrient solution or, being in air medium, periodically by this solution are spraied.

HYDRAULIC DRIVE, the same, that a hydraulic drive.

The HYDRODESIGN of a name of S.J.Zhuka, the All-Russia association (up to 1991 design and survey and a research institute), it is based in 1936 in Moscow. Designing of shipping canals and hydropower structures. Among activities of institute - designs of waterpower plants Volga (Russian Federation) and Dneprovskogo (Ukraine) of cascades, Brotherly, Krasnoyarsk and Sajano-SHushenskoj in the Russian Federation, Altitude Asuanskoj dams in Egypt, Evfratskogo a hydrocomplex in Syria, etc.

HYDROSALPINX (from gidro... And grech. salpinx - a pipe), inflammatory disease of a parent pipe with a clump in its lumen of a serum.

SEAPLANE (hydroplane), airplane for take-off from water and planting to it. Distinguish a flying boat (the body is in the form of boats; ensures take-off, planting and maintenance of a seaplane on water), an amphibia (with a wheeled undercarriage for dry-land touchdown) and a floatplane (instead of sprockets floats are established).

SLURRY, mechanical mixture of particles of loose or ground solid rocks with water by development by their means of a hydro-mechanization.

HYDROSTAT (from gidro... And... stat), the apparatus for submerged probes and activities; alights on a cable from vessel - base. In the chamber of a hydrostat (orbicular or a cylindricity) air revitalization systems, research instrumentation, the earphone, etc. are placed crew (1-3 persons). Hydrostats have devices for fixation on object of activities, positioners, propellers. A driving depth up to 300 m.

HYDROSTATICS (from gidro... And a statics), section of hydromechanics in which balance of liquids and influence of reposing liquids on bodies submersed in them and on the surfaces limiting a liquid is studied.

The HYDROSTATIC PARADOX, weight of a liquid, juicy in a vessel, can differ from the force of pressure rendered by her on a bottom of a vessel. So, in vessels extending up force of pressure on a bottom is less than weight of a liquid, and in cotracting - it is more. In a cylindrical vessel both forces are equal. The hydrostatic paradox that, that as hydrostatic pressure r always normally to vascular walls, force of pressure on slope walls has a vertical component ð1 which indemnifies weight redundant against the cylinder of 1 volume of a liquid in a vessel 3 and weight of the missing volume of a liquid in a vessel 2 speaks. The hydrostatic paradox is found by B.Paskalem (1654).

HYDROSTATIC PRESSING, the same, that a hydroextrusion.

HYDROSPHERE (from gidro... And an orb), set of all water objects of a terrestrial globe: oceans, seas, the rivers, lakes, water reservoirs, bogs, underground waters, icehouses and a snow mantle. Often a hydrosphere imply only oceans and starving.

HYDROTAXIS, see in an item. Taxises.

HYDROTHERAPY (from gidro... And therapy), the same, that a water treatment.

HYDROTHERMAL DEPOSITS (from gidro... And grech. therme - it is warm), the deposits of mineral wealths which are generatrix at a deposition of substances, dissolved in circulating in entrails of the Earth hot salting waters (at the temperature of from 700-600 °S till 50-20 °S).

HYDROTHERMAL SYNTHESIS, obtaining of crystals of inorganic matters (napr., SiO2, phosphates) in the conditions modelling processes of education of minerals in an earth interior. It is based on abilities of water and water solutions at heats (up to 500 °S) and pressure (it is routine 10-80 MPa) to solve substances, practically insoluble in a usual terms, - some oxides, silikates, sulphides, etc. In similar conditions cultivate also large single crystals (napr., quartz crystals in mass up to 50 kg).

HYDRAULIC ENGINEERING (from gidro... And technique), branch of science and the technique, engaging study of water resources, their use for needs of a national economy and extirpation with devastating effect of waters with the help of special (hydrotechnical) structures, devices and the equipment.

HYDRAULIC ENGINEERINGS INSTITUTE All-Russia (VNIIG) him. B.E.Vedeneyev, it is based in 1921 in Petrograd. Probes and developments in range of hydrotechnical constructions.

HYDROTECHNICAL CONSTRUCTIONS, intended for use of water resources, and also for extirpation with destructive action of water physical agent. Distinguish hydrotechnical constructions: water-supported (dams, dams, etc.), vodoprovodjashchie (channels, pipe lines, tunnels, etc.), reguljatsionnye (the groynes enclosuring shafts, etc.), water-intaking, water-overflow, special (buildings of waterpower plants, sluices, boat lifts, etc.). Often hydrotechnical constructions integrate in a unified complex - a hydraulic project.

The HYDRAULIC CONCRETE, is applied to construction of the structures permanently located in water or periodically contacting with aqueous medium; a version of a concrete of high specific weight. It is defined by high rust resistance, water tightness, frost resistance.