to compact concrete by vibration
21Chakra — For other uses, see Chakra (disambiguation). Coloured Chakras with Descriptions …
22Vacuum cleaner — Cylinder vacuum cleaner for home use. French train vacuum cleaner …
23Reverberation — is the persistence of sound in a particular space after the original sound is removedFact|date=March 2008. When sound is produced in a space, a large number of echoes build up and then slowly decay as the sound is absorbed by the walls and air,… …
24Nuclear marine propulsion — is propulsion of a ship by a nuclear reactor. Naval nuclear propulsion is propulsion that specifically refers to naval warships (see Nuclear navy). Only a very few experimental civil nuclear ships have been built; the elimination of fossil fuel… …
25Flood control in the Netherlands — Without dikes, this part of the Netherlands would be flooded …
26military technology — Introduction range of weapons, equipment, structures, and vehicles used specifically for the purpose of fighting. It includes the knowledge required to construct such technology, to employ it in combat, and to repair and replenish it.… …
27South American Indian languages — Introduction group of languages that once covered and today still partially cover all of South America, the Antilles, and Central America to the south of a line from the Gulf of Honduras to the Nicoya Peninsula in Costa Rica. Estimates of… …
28Duo Zikr — Origin Kiev, Ukraine; Moscow, Russia Genres free voice, ambient Years active from 1993 Labels Free Website …
