For a steel alloy it has been determined that a carburizing heat treatment of 10 h duration at 753°C will raise the carbon concentration to 0.50 wt% at a point 3.3 mm from the surface. Estimate the time necessary to achieve the same concentration at a 5.6 mm position for an identical steel and at a carburizing temperature of 1060°C. Assume that D0 is 3.2 × 10-5 m2/s and Qd is 104 kJ/mol.

Which of the following is an easy way to remember the modified “x” tire rotation? a. nondrive wheels straight, cross the drive wheels b. drive wheels straight, cross the nondrive wheels c. drive wheels crossed, nondrive wheels straight d. drive wheels crossed, nondrive wheels crossed

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]

Plan an experiment to measure the surface tension of a liquid similar to water. if necessary, review the ncfmf video surface tension for ideas. which method would be most suitable for use in an undergraduate laboratory? what experimental precision could be expected?