Thermal conductivity and enthalphy data for nitrogen gas
By way of comparison, using NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP) – NIST Standard Reference Database 23, Version 9, I have got a specific enthalpy of $h=306.26\ \mathrm{kJ/kg}$ and thermal conductivity of $\lambda=25.601\ \mathrm{mW/(K\ m)}$ for nitrogen at a temperature of $T=295.15\ \mathrm K$ and a pressure of $p=0.5\ \mathrm{bar}$.

Note that the absolute value of enthalpy at a single state point is meaningless; it is only the difference between two different state points that matters.