Cryogenics Cryogenics In physics, cryogenics is the production and behaviour of materials at very low temperatures. A person who studies elements that have been subjected to extremely cold temperatures is called a "cryogenicist". It is not well-defined at what point on the temperature scale refrigeration ends and cryogenics begins, but scientists assume a gas to be cryogenic if it can be liquefied at or below . The U.S. National Institute of Standards and Technology has chosen to consider the field of cryogenics as that involving temperatures below . This is a logical dividing line, since the normal boiling points of the
Numeral prefix words with the same spellings (such as and ). Several technical numerical prefixes are not derived from words for numbers. ( is not derived from a number word, for example.) Similarly, some are only derived from words for numbers inasmuch as they are word play. ( is word play on , for example. See its etymology for details.) The root language of a numerical prefix need not be related to the root language of the word that it prefixes. Some words comprising numerical prefixes are hybrid words. In certain classes of systematic names, there are a few other exceptions to