Applications
Hydraulic brakes
Artesian well
Blood pressure
Hydraulic head
Plant cell turgidity
Pythagorean cup
Pressure washing

Explosion or deflagration pressures
Explosion or deflagration pressures are the result of the ignition of explosive gases, mists, dust/air suspensions, in unconfined and confined spaces. Negative pressures
While pressures are, in general, positive, there are several situations in which negative pressures may be encountered:

When dealing in relative (gauge) pressures. For instance, an absolute pressure of 80 kPa may be described as a gauge pressure of −21 kPa (i.e., 21 kPa below an atmospheric pressure of 101 kPa). For example, abdominal decompression is an obstetric procedure during which negative gauge pressure is applied intermittently to a pregnant womans abdomen. Negative absolute pressures are possible. They are effectively tension, and both bulk solids and bulk liquids can be put under negative absolute pressure by pulling on them. Microscopically, the molecules in solids and liquids have attractive interactions that overpower the thermal kinetic energy, so some tension can be sustained. Thermodynamically, however, a bulk material under negative pressure is in a metastable state, and it is especially fragile in the case of liquids where the negative pressure state is similar to superheating and is easily susceptible to cavitation. In certain situations, the cavitation can be avoided and negative pressures sustained indefinitely, for example, liquid mercury has been observed to sustain up to −425 atm in clean glass containers. Negative liquid pressures are thought to be involved in the ascent of sap in plants taller than 10 m (the atmospheric pressure head of water).
An abscess of the thymus (also known as "Dubois abscesses") is a condition that is one of many possible causes of cysts in the mediastinum. It can present with chest pain behind the sternum.It can be associated with congenital syphilis.Although the thymus is usually classified with the immune system, thymic diseases are classified with endocrine disorders in ICD-9 and ICD-10. References


== External links ==