1045 steel is carburized at 650 degree C for 500 hr. The carbon concentration is 0.6 wt% at a position of 3.7 mm beneath the surface. Qd and D0 are respectively equal to 0.83 eV/atom and 3.47 in2/hr. Calculate the surface concentration of carbon in units of kg carbon per m3 of the alloy. Assume that the alloy has a density of 7.87 g/cc for that calculation.