as mechanism is unlikely to be the predominant mechsm
m an oxidizing atmosphere (ari or oxygen) The validity of a
single stage equation (1) over the entue range IS questionable
even in an intert atmosphere (argon or nitrogen) In this paper,
we have restncted our analysis to the commonly used models
and methodology, so as to enable a comparative evaluaion
The limitation of these models and altemhve approaches are
bemg emed and reported separately
The rate of disappearance of A may be represented by the
followmg relahon