The trains are pressure-sealed to reduce passenger discomfort from pressure variations during tunnel passages.
Computer-aided photography can be used to produce false-color images, where the color range corresponds to the pressure variations.
It is a wind belt where air is warm, with little pressure variations.
These disturbances propagate from their source as longitudinal pressure variations along the path of propagation.
Note that the pressure drop across the regenerator is very low compared to the overall pressure variation in the cycle.
The mixed systems operation combines pressure variations from positive to negative.
For getting the cooling, the source of the pressure variations is unimportant.
Coaches are pressurised to avoid uncomfortable pressure variations in tunnels.
The constant volume case is important in geochemistry and atmospheric chemistry where pressure variations are significant.
"I'll filter them at maximum sensitivity for pressure variations two orders of magnitude or greater with a duration under ten seconds."