to leave a vacuum
91light — light1 lightful, adj. lightfully, adv. /luyt/, n., adj., lighter, lightest, v., lighted or lit, lighting. n. 1. something that makes things visible or affords illumination: All colors depend on light. 2. Physics …
92spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… …
93Casting (metalworking) — Casting iron in a sand mold In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which… …
94Spontaneous symmetry breaking — Quantum field theory (Feynman diagram) …
95Getter — Getters are reactive materials used for removing traces of gas from vacuum systems. Flashed getters are prepared by arranging a reservoir of a volatile and reactive material inside the vacuum system; once the system is sealed, the material is… …
96X-ray tube — An X ray tube is a vacuum tube that produces X rays. They are used in X ray machines. X rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X ray tubes evolved from experimental… …
97Glass-to-metal seal — Glass to metal seals are a very important element of the construction of vacuum tubes, electric discharge tubes, incandescent light bulbs, glass encapsulated semiconductor diodes, reed switches, pressure tight glass windows in metal cases, and… …
98Cathode — Diagram of a copper cathode in a galvanic cell (e.g., a battery). A positive current i flows out of the cathode (CCD mnemonic: Cathode Current Departs). A cathode is an electrode through which electric current flows out of a polarized electrical… …
99Finnish Civil War — Tampere s civilian buildings destroyed in the civil war. Date …
100Robot — This article is about mechanical robots. For other uses of the term, see robot (disambiguation). For software agents, see Bot. ASIMO (2000) at the Expo 2005, a humanoid robot …
