electron-indicator tube
31medicine, history of — Introduction the development of the prevention and treatment of disease from prehistoric and ancient times to the 20th century. Medicine and surgery before 1800 Primitive (primitive culture) medicine and folklore Unwritten history is not… …
32Crystal oscillator — A miniature 4 MHz quartz crystal enclosed in a hermetically sealed HC 49/US package, used as the resonator in a crystal oscillator. A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal …
33Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
34Pyridine — Pyridine …
35Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
36Elektronenröhre — Eine Elektronenröhre ist ein elektronisches Bauelement, das aus einem evakuierten oder gasgefüllten Kolben aus Glas, Stahl oder Keramik besteht, in den mehrere Elektroden, mindestens eine beheizte Kathode und eine Anode, eingelassen und von außen …
37ear, human — ▪ anatomy Introduction organ of hearing and equilibrium that detects and analyzes noises by transduction (or the conversion of sound waves into electrochemical impulses) and maintains the sense of balance (equilibrium). The human ear, like …
38Metalworking — Machining a bar of metal on a lathe. Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts… …
39steel — steellike, adj. /steel/, n. 1. any of various modified forms of iron, artificially produced, having a carbon content less than that of pig iron and more than that of wrought iron, and having qualities of hardness, elasticity, and strength varying …
40radar — Synonyms and related words: AA radar, AFC, AFC mixer, CRT, CW oscillator, MAD radar, Navaglobe, Oboe, TR switch, TR unit, VAR, Volscan, altimeter, amplifier, analyzer, astronavigation, automatic electronic navigation, automation, avionics,… …
