A gas which can be liquefied only at very low temperatures, and was formerly believed to be incapable of liquefaction; specifically a gas that is above its critical point, and so is impossible to liquefy by pressure alone. Nitrogen and Oxygen, the major constituents of air, are both permanent gases. Water vapour can be readily condensed at room temperature. It is not a permanent gas and is removed from a vacuum system under evacuation much more slowly than Nitrogen and Oxygen.
« Back to Glossary IndexYou may also like
There is presently rapid development of non-volatile memory devices in the form of Magnetic Tunnel Junctions. These structures form the memory elements […]
The sun is a constant in our planet’s life – providing fundamental forces by which we exist. So it may come as […]
Sputtering as a means of thin film deposition has been used for many years. From time-to-time new techniques, or variations in […]
The International system of scientific units is having a shake-up; with four of the basic measurement units (the ampere, kilogram, kelvin and […]