Estimate the thermal diffusivity of butter at 20°C.

An aluminum film was deposited at a rate of 1 μm/min in vacuum at 25 °C. It was found that the oxygen content in the film was 0.01 at% (remember that is only O). What was the total air pressure in the system (assuming air is 20% O2)?

To increase the hardness of a steel gear, it was carburized at 850oC by introducing 1.3%C at its  steel surface. What will be the final carbon content 1.4 mm beneath the surface if this treatment  was lasted for 26 hours. The initial carbon content of steel is 0.1%C. (gas constant is 8.31 j/mol.K)

ε = ce { 3. Assume the activation energy for the creep of Al2O3 is 425kJ/mol. (a) Predict the creep rate, &, for Al2O3 at 1000°C and 1800 psi applied stress. (See Table 6.12 for data at 1300°C and 1800psi.) (b) Calculate the lifetime of an furnace tube at 1000°C and 1800 psi if 1% total strain is permissible. (ε = 2.7x10-6/hr for Al2O3 at 1300°C and 1800psi.)