A sheet of steel 2.5 mm thick has nitrogen atmospheres on both sides at 900C and is permitted to achieve a steady-state diffusion condition. The diffusion coefficient for nitrogen in steel at this temperature is 1.2e-10 m2/s and the diffusion flux is found to be 9.12e-8 kg/m2-s. Also, it is known that the concentration of nitrogen in the steel at the high pressure surface is 2 kg/ m3. How far into the sheet from this high pressure side will the concentration be 0.52 kg/ m3?