For closed systems with no external source or sink of energy, the first law of thermodynamics states that a system's energy is constant unless energy is transferred in or out by mechanical work or heat, and that no energy is lost in transfer. This means that it is impossible to create or destroy energy.
GROGAN. The Irish name Grogan is derived from the native Gaelic O'Gruagain Sept that was initially located in County Roscommon but which became widely dispersed. The name is derived from a Gaelic word meaning 'fierceness'. Grugan, Groggan, Groogan and O'Grogan are among the variants of this name.he Irish name Grogan is derived from the native Gaelic O'Gruagain Sept that was initially located in County Roscommon but which became widely dispersed.
Curiously, in addition to the Old English word gÄr meaning spear; GÄr also has a corresponding rune (á¸) in the (Old English) Anglo-Saxon futhorc, which again has the meaning spear (and is transliterated into the modern letter G).ther surnames derived from Gerard and Gerald include: Gerrard, Garratt, Garret, Garred, Garrad, Garrard, Garrod, Jarrett, Jarratt, Jarrard, and Jerrold.