Accordingly,
the energy provided into the carrier gas (Ein) is equivalent to the multiplication of DHT, Q, and duration (t, min), namely,
Ein = DHT Q t. The operating conditions of 300 C (or 573 K) for
60 min has the highest energy input, this energy input is thus
adopted as the reference energy input (Ein,ref). An index of dimensionless
energy input (DEI) is defined by