Awave soldering machine failures follow 3-parameter weibull distribution with β = 1.6, η = 800 hours and γ = 500 hours. the cost of one pm is $ 6000 and the cost of an unexpected failure is $ 16 000. the machine operates 24 hours/day and pms are done every three months. determine the yearly cost for this maintenance schedule.

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]