A differential nitrogen pressure exists across a 3 mm thick steel furnace wall. After some time, steady-state diffusion of the nitrogen is established across the wall. Given that the nitrogen concentration on the high-pressure surface of the wall is 2 kg/m^3 and on the low pressure surface is 0.2 kg/m^3, calculate the flow of the nitrogen through the wall (in kg/m^3) if the diffusion coefficient for nitrogen in steel is 5.0 x 10^-11 m^2/s at the furnace operating temperature. Note: "h" is hour.