Uson SPRINT LC, Owner'S Manual

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Ideal vs. Real Gas
Gases are typified as ideal or real. The ideal gas follows certain gas Laws
exactly, whereas a real gas closely follows these Laws only at low density.
Ideal behavior can be ascribed to a real gas if its molecules are separated
by very large distances, so that intermolecular attraction is negligible.
Adiabatic Process
(ad-ee-uh-bat-ik)
Adiabatic compression and expansion are thermodynamic processes in
which the pressure of a gas is increased or decreased without any
exchange of heat energy with the surroundings. Any process that occurs
without heat transfer is called an adiabatic process.
The adiabatic compression or expansion of a gas can occur if the gas is
insulated from its surroundings or if the process takes place quickly
enough to prevent any significant heat transfer. This is essentially the case
in a number of important devices, including air compressors.
An adiabatic expansion is usually accompanied by a decrease in the gas
temperature. This can be observed in a common aerosol can, which
becomes cold after some compressed gas is released. The reason for the
temperature drop is that the gas is released too quickly to absorb any
significant heat energy from its surroundings. Work performed in
expanding the released gas drains some internal energy of the gas still in
the can, making it colder. After the can metal becomes cold, however, the
process is no longer adiabatic.
In a similar fashion, adiabatic compression usually increases the
temperature of a gas, since work is done on the system by the
surroundings. For example, when air is pumped into an automobile tire,
the air temperature rises as a result of adiabatic compression.