travelling-wave ratio
51Optical coating — Optically coated mirrors and lenses. An optical coating is one or more thin layers of material deposited on an optical component such as a lens or mirror, which alters the way in which the optic reflects and transmits light. One type of optical… …
52Spud gun (cannon) — This article is about pipe based cannons and similar which use air pressure, or combustion of a gaseous fuel, or both, to launch large projectiles at low speed. They are in two types: * To fire whole potatoes. These launchers are built and fired… …
53undersea exploration — Introduction the investigation and description of the ocean waters and the seafloor and of the Earth beneath. Primary objectives and accomplishments Included in the scope of undersea exploration are the physical and chemical… …
54Spud gun — For the child s toy which fires small pieces of potato, see spud gun (toy). A pneumatic potato cannon A potato cannon (also known as a spud gun or spudzooka ) is a pipe based cannon which uses air pressure (pneumatic), Propellant, or… …
55Hull (watercraft) — Half hull of the 46 gun ship of the line Tigre, build from 1724 in Toulon after plans by Blaise Coulomb A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull …
56Space elevator — A space elevator for Earth would consist of a cable anchored to the Earth s equator, reaching into space. By attaching a counterweight at the end (or by further extending the cable upward for the same purpose), the center of mass is kept well… …
57Control line — Brodak Control Line Aerobatic Strega in flight Control line (also called U Control ) is a simple and light way of controlling a flying model aircraft. The aircraft is connected to the operator by a pair of lines, attached to a handle, that work… …
58Kamioka Observatory — The nihongo|Kamioka Observatory, Institute for Cosmic Ray Research|神岡宇宙素粒子研究施設|Kamioka Uchū Soryūshi Kenkyū Shisetsu is a neutrino physics laboratory located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co. near the Kamioka… …
59Pelagic fish — A school of large pelagic predator fish (giant trevally) sizing up a school of small pelagic prey fish (anchovies) Pelagic fish live near the surface or in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or… …
60Marine habitats — Coral reefs provide marine habitats for tube sponges, which in turn become marine habitats for fishes Littoral zone …
