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.
Last name origins & meanings: 1  Irish: reduced Anglicized form of Gaelic O Ã³ âgrugain grÃºgÃ¡in Descendant â, of grugan grÃºgÃ¡n a personal name from a âdiminutiveâ, âofâ. 2  Grug: grÃºg Anger fierceness irish Reduced ANGLICIZED Form âof gaelic O â, Ã³ gruagain gruagÃ¡in descendant of gruagan gruagÃ¡n a âpersonalâ.  name from a diminutive of gruag hairast name origins & meanings: 1  Irish: reduced Anglicized form of Gaelic O Ã³ âgrugain grÃºgÃ¡in Descendant â, of grugan grÃºgÃ¡n a personal name from a âdiminutiveâ, âofâ. 2  Grug: grÃºg Anger fierceness irish Reduced ANGLICIZED Form âof gaelic O â, Ã³ gruagain gruagÃ¡in descendant of gruagan gruagÃ¡n a âpersonalâ.  name from a diminutive of gruag hair