Cryogenics scale, both of which measure from absolute zero, rather than more usual scales such as Celsius or Fahrenheit, with their zeroes at arbitrary temperatures. The word "cryogenics" stems from Greek "κρύο (cryo)" – "cold" + "γονική (genic)" – "having to do with production". Cryogenic fluids with their boiling point in Kelvin Liquefied gases, such as liquid nitrogen and liquid helium, are used in many cryogenic applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally purchasable around the world. Liquid helium is also commonly used and allows for the lowest attainable temperatures to be reached. These
English prefix English prefix English prefixes are affixes (i.e., bound morphemes that provide lexical meaning) that are added before either simple roots or complex "bases" (or "operands") consisting of (a) a root and other affixes, (b) multiple roots, or (c) multiple roots and other affixes. Examples of these follow: English words may consist of multiple prefixes: "anti-pseudo-classicism" (containing both an "anti-" prefix and a "pseudo-" prefix). In English, all prefixes are derivational. This contrasts with English suffixes, which may be either derivational or inflectional. As is often the case with derivational morphology, many English prefixes can only be added to bases of