Mastoid surgery is usually performed under general anaesthetic and can take up to 3 hours. The method used will depend on the level of infection and damage within your middle ear. Your surgeon will make an incision (cut) either behind your ear or just above your ear. They will remove the bone that is covering the infected area leaving the area (called the mastoid cavity) open.
steam noun [U]. B2 the âhot âgas that is âproduced when âwater âboils: Steam ârose from the âsimmering âstew. steam âturbines a steam âengine/âlocomotive the âage of steam (= the âperiod when steam âprovided âpower for ârailways and âfactories) The âpump is âdriven by steam.
A steam engine is a machine that burns coal to release the heat energy it containsâso it's an example of what we call a heat engine. It's a bit like a giant kettle sitting on top of a coal fire. The heat from the fire boils the water in the kettle and turns it into steam.hoto: Close-up of the piston and cylinder in a steam engine. Our diagram up above shows a very simple, one-cylinder steam engine powering a steam locomotive down a track. This is called a rotary steam engine, because the piston's job is to make a wheel rotate.