Examples are the Upper and Lower peninsulas of the U.S. state of Michigan, the Scandinavian Peninsula and the Niagara peninsula.[1][2][3][4] The surrounding water is usually understood to be continuous, though not necessarily named as a single body of water.
A vacuum breaker is an attachment commonly placed on a bibcock valve or toilet or urinal flush valve, that prevents water from being siphoned backward into the public drinking water system. This prevents contamination should the public drinking water system's pressure drop. vacuum breaker typically contains a plastic disc that is pressed forward by water supply pressure, and covers small vent holes.
Sulfur hexafluoride circuit breakers protect electrical power stations and distribution systems by interrupting electric currents, when tripped by a protective relay. Instead of oil, air, or a vacuum, a sulfur hexafluoride circuit breaker uses sulfur hexafluoride gas to cool and quench the arc on opening a circuit. Advantages over other media include lower operating noise and no emission of hot gases, and relatively low maintenance. Developed in the 1950's and onward, SF6 circuit breakers are wi