Forming gas Forming gas Forming gas is a mixture of hydrogen (mole fraction varies) and nitrogen. It is sometimes called a "dissociated ammonia atmosphere" due to the reaction which generates it: It can also be manufactured by thermal cracking of ammonia, in an ammonia cracker or forming gas generator. Forming gas is used as an atmosphere for processes that need the properties of hydrogen gas. Typical forming gas formulations (5% H2 in N2) are not explosive. It is used in chambers for gas hypersensitization, a process in which photographic film is heated in forming gas to drive out moisture and oxygen and
Grey atmosphere Grey atmosphere The Grey atmosphere (or gray) is a useful set of approximations made for radiative transfer applications in studies of stellar atmospheres based on the simplification that the absorption coefficient formula_1 of matter within the atmosphere is constant for all frequencies of incident radiation. The application of the grey atmosphere approximation is the primary method astronomers use to determine the temperature and basic radiative properties of astronomical objects including the Sun, planets with atmospheres, other stars, and interstellar clouds of gas and dust. Although the model demonstrates good correlation to observations, it deviates from observational results because real atmospheres