How does one observe Lent? It differs from person to person and church to church, but some of the things Christians opt to do to observe Lent include: 1  On the first day of Lent (Ash Wednesday), some Christians mark their foreheads with ash as a symbol of sorrow and mourning over their sin.
An uncommon practice is to submerge the computer's components in a thermally, but not electrically, conductive liquid. Although rarely used for the cooling of personal computers, liquid submersion is a routine method of cooling large power distribution components such as transformers.
Other methods of refrigeration include the air cycle machine used in aircraft; the vortex tube used for spot cooling, when compressed air is available; and thermoacoustic refrigeration using sound waves in a pressurized gas to drive heat transfer and heat exchange; steam jet cooling popular in the early 1930s for air conditioning large buildings; thermoelastic cooling using a smart metal alloy stretching and relaxing.