  We studied the outflow behaviour from accretion discs around black holes
taking into account the vertical equilibrium accretion flow model. The outflow
rate is found to depend crucially on flow composition. Our approach is to study
the outflow behaviour as function of inflow around black holes with an equation
of state which allows flow to be thermally relativistic close to black holes
and non relativistic far away from black holes. We studied shock ejection
model. A pure electron positron pair flow never undergoes shock transition
while presence of some baryons (common in outflows and jets) makes it possible
to have standing shock waves in the flow. It can be concluded that the presence
of protons is necessary for the flow to show the outflow behaviour. The outflow
rate is maximum when the flow contains the proton number density which is 27%
of the electron number density. We conclude that a pure electron-positron jet
is unlikely to form.
