For a steel alloy it has been determined that a carburizing heat treatment of 14 h duration at 763°C will raise the carbon concentration to 0.46 wt% at a point 2.2 mm from the surface. Estimate the time necessary to achieve the same concentration at a 5.3 mm position for an identical steel and at a carburizing temperature of 1000°C. Assume that D0 is 1.5 × 10–5 m2/s and Qd is 104 kJ/mol. (Hint – start with equation 5.6 from Callister text book)

1in2 processor chip can be modelled as an isothermal plane wall of silicon, isothermal on both sides. the power input to the bottom of the plane wall, or the processing power of the chip, often called the thermal design power (tdp), is 100w. assume the periphery is adiabatic. the silicon is 400 microns thick. the temperature at the junction, or in this case on the bottom of the isothermal plane wall, is 85°c. what is the top surface temperature, assuming that the only mode of heat transfer is conduction