A gas mixture of $50 \mathrm{wt} . \%$ argon and $50 \mathrm{wt} . \%$ helium flowing through a horizontal tube of uniform diameter at a rate of $1 \mathrm{~kg} \mathrm{~s}^{-1}$ is heated from $300$ K to $400$ K at $1$ bar. Neglect shaft work, and changes in kinetic as well as potential energies between the inlet and the outlet. Assume the mixture exhibits ideal gas behavior. The specific enthalpies of the components are given in the following table.
| $\text{Component}$ | $\text{Specific enthalpy }(\mathrm{kJ\,kg^{-1}})$ |
| $\text{at 300 K}$ | $\text{at 400 K}$ |
| Argon | $348$ | $400$ |
| Helium | $1574$ | $2092$ |
At steady state, the heat input required (in kW ) is $\_\_\_\_$ (rounded off to the nearest integer).
