Real gas

Real gases are non-hypothetical gases whose molecules occupy space and have interactions; consequently, they adhere to gas laws. To understand the behaviour of real gases, the following must be taken into account:

For most applications, such a detailed analysis is unnecessary, and the ideal gas approximation can be used with reasonable accuracy. On the other hand, real-gas models have to be used near the condensation point of gases, near critical points, at very high pressures, to explain the Joule–Thomson effect and in other less usual cases. The deviation from ideality can be described by the compressibility factor Z.

Models

van der Waals model

Real gases are often modeled by taking into account their molar weight and molar volume

Where P is the pressure, T is the temperature, R the ideal gas constant, and V_m the molar volume. a and b are parameters that are determined empirically for each gas, but are sometimes estimated from their critical temperature (T_c) and critical pressure (P_c) using these relations:

Gas

Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide). A gas mixture would contain a variety of pure gases much like the air. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer. The interaction of gas particles in the presence of electric and gravitational fields are considered negligible as indicated by the constant velocity vectors in the image. One type of commonly known gas is steam.

The gaseous state of matter is found between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention. High-density atomic gases super cooled to incredibly low temperatures are classified by their statistical behavior as either a Bose gas or a Fermi gas. For a comprehensive listing of these exotic states of matter see list of states of matter.

Gas (musician)

Gas is a music project of Wolfgang Voigt (born 1961), a Cologne, Germany-based electronic musician. Voigt cites his youthful LSD experiences in the Königsforst, a German forest situated near his hometown of Köln, as the inspiration behind his work under the name Gas. He has claimed that the intention of the project is to "bring the forest to the disco, or vice-versa".

Aliases and projects

Voigt is known for his numerous, nearly inexhaustible list of one-off projects and aliases. Of these, his best known is arguably Gas, a project that saw the marriage of ambient music and 4/4 techno.

Other names under which Voigt has released music include, but are not limited to, All, Auftrieb, Brom, C.K. Decker, Centrifugal Force, Crocker, Dextro NRG, Dieter Gorny, Digital, Dom, Doppel, Filter, Freiland, Fuchsbau, Gelb, Grungerman, Kafkatrax, Love Inc., M:I:5, Mike Ink, Mint, Panthel, Popacid, Riss, RX7, Split Inc., Strass, Studio 1, Tal, Vinyl Countdown, W.V., Wassermann, and X-Lvis.

Characteristics

Gas (1981 film)

(not to be confused with a similar sounding 1970 film Gas-s-s-s)

Gas is a 1981 Canadian comedy film released by Paramount Pictures, the plot of which was inspired by the 1979 energy crisis.

Plot summary

A small Midwestern town is thrown into chaos when the local oil tycoon (Sterling Hayden) orchestrates a phony oil shortage in order to increase profits. A news reporter (Susan Anspach) tries to uncover the plot, and a radio DJ in a helicopter (Donald Sutherland) reports on the craziness caused by the gasoline shortage.

Cast