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 enlier range IS questionable
even in an inter atmosphere (argon or nitrogen) In this paper,
we have restricted our analysis to the commonly used models
and methodology, so as to enable a comparative evaluaion
The limitation of these models and alternative approaches are
bemg emed and reported separately
The rate of disappearance of A may be represented by the
following relahon