What name is given to a volcanic opening that gives out gas and steam?
Volcanic gas smokers, at the point of emission into the cold seawater. The gas release can occur by advection through fractures, or via diffuse degassing through large areas of permeable ground as diffuse degassing structures (DDS). At sites of advective gas loss, precipitation of sulfur and rare minerals forms sulfur deposits and small sulfur chimneys, called fumaroles. Very low-temperature (below 100 °C) fumarolic structures are also known as solfataras. Sites of cold degassing of predominantly carbon dioxide are called mofettes. Hot springs on volcanoes often show a measurable amount of magmatic gas in dissolved form. Volcanic gases were collected and analysed as
Combined gas and steam Combined gas and steam Combined gas and steam (COGAS) is the name given to marine compound powerplants comprising gas and steam turbines, the latter being driven by steam generated using the heat from the exhaust of the gas turbines. In this way, some of the otherwise lost energy can be reclaimed and the specific fuel consumption of the plant can be decreased. Large (land-based) electric powerplants built using this combined cycle can reach conversion efficiencies of over 60%. If the turbines do not drive a propeller shafts directly and instead a turbo-electric transmission is used, the system is also known