Many emerging technologies, including that used in ever-improving cell phones, begin with the capture and analysis of speech. speech is a continuum of variances in acoustic pressure produced by the talker. in wireless technology, electronics inside a mobile telephone converts the waves produced by the talker to impulses on the transmitting side and on the receiving side it converts these impulses back to their original wave form.

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]