beam power efficiency
41Heterojunction bipolar transistor — The heterojunction bipolar transistor (HBT) is a type of bipolar junction transistor (BJT) which uses differing semiconductor materials for the emitter and base regions, creating a heterojunction. The HBT improves on the BJT in that it that can… …
42Orlunda radio transmitter — Orlunda transmitter building today with 86.4 metre tall guyed mast used for mobile phone services …
43electron tube — an electronic device that consists, typically, of a sealed glass bulb containing two or more electrodes: used to generate, amplify, and rectify electric oscillations and alternating currents. Also called electronic tube. Cf. gas tube, vacuum tube …
44Inertial confinement fusion — (ICF) is a process where nuclear fusion reactions are initiated by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium.To compress and heat the fuel, energy is… …
45Antenna (radio) — Whip antenna on car …
46Parabolic antenna — A parabolic satellite communications antenna at Erdfunkstelle Raisting, the biggest facility for satellite communication in the world, in Raisting, Bavaria, Germany. It has a Cassegrain type feed. A parabolic antenna is an antenna that uses a… …
47technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
48Bicycle lighting — has two purposes: seeing and being seen. There are many types of bicycle lights available, each with its own advantages and disadvantages. There is no one best solution for any rider, and many riders mix and match different technologies to… …
49Business and Industry Review — ▪ 1999 Introduction Overview Annual Average Rates of Growth of Manufacturing Output, 1980 97, Table Pattern of Output, 1994 97, Table Index Numbers of Production, Employment, and Productivity in Manufacturing Industries, Table (For Annual… …
50Spacecraft propulsion — A remote camera captures a close up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Spacecraft propulsion is any method used to accelerate spacecraft and artificial… …
