Briefly describe and reason the differences between metals, ceramics, and polymers on the origins/causes of electrical conduction and thermal conduction as a function of temperature and impurity concentration. (b) Why are the differences between metals, ceramics, and polymers in electrical conductivity normally much more significant (up to 10-15 orders of magnitude) than those in thermal conductivity (less than one order of magnitude)

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.

Hydraulic fluid with a sg. of 0.78 is flowing through a 1.5 in. i.d. pipe at 58 gal/min. the fluid has an absolute viscosity of 11.8 x 105 lbf-sec/ft2. is the flow laminar, turbulent or within the critical range? give both a numerical reynolds number and a term answer.

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]