text: The specific characteristics of MSGE as compared with MSNE is that the emitted neutral particles are limited to gas molecules. MSGE is opposite to Mechanically Stimulated Gas Absorption that usually occurs under fretting corrosion of metals, exposure to gases at high pressures, etc. 
  There are three main sources of MSGE: 
  : I. Gas molecules adsorbed on the surface of a solid
  : IIa. Gases dissolved in the material bulk
  : IIb. Gases occluded or trapped in micro- and nanovoids, discontinuities and on defects in the material bulk
  : III. Gases generated as a result of mechanical activation of chemical reactions.
  Generally, for producing MSGE, the mechanical action on the solid can be of any type including tension, compression, torsion, shearing, rubbing, fretting, rolling, indentation, etc. In previous studies carried out by various groups it was found that MSGE is associated mainly with plastic deformation, fracture, wear and other irreversible modifications of a solid. Under elastic deformation MSGE is almost negligible and only was observed just below elastic limit due to possible microplastic deformation. 
  In accordance to the main sources, the emitted gases usually contain hydrogen (source type IIa), argon (for coatings obtained using PVD in Ar plasma - source type IIb), methane (source type III), water (source type I and/or III), carbon mono- and dioxide (source type I/III). 
  The knowledge on the mechanisms of MSGE is still vague. On the basis of the experimental findings it was speculated that the following processes can be related with MSGE:
  # Transport of gas atoms by moving dislocations
  # Gas diffusion in the bulk driven by gradient of mechanical stress
  # Phase transformation induced by deformation
  # Removal of oxide and other surface layers, which prevent exit of dissolved atoms on the surface
  # Extension of free surface
  Thermal effect seems to be irrelevant to the gas emission under light load conditions.