This defense in depth discussion scenario is an intentional cybersecurity attack on the water utility’s SCADA system. It occurs during the fall after a dry summer in Fringe City. The water utility’s Information Technology (IT) person did not receive an expected pay raise and decides to reprogram the SCADA system to shut off the high-lift pumps. The operator’s familiarity with the SCADA system allows him to reprogram the alarms that typically notify operators of a high-lift pump failure. In addition, he prevents access to the SCADA system by others. A wildfire breaks out on the outskirts of the city. Please identify what type(s) of new countermeasures should have been implemented to prevent this cyber attack from occurring.
Show that the logarithmic mean area Am of a cylinder of unit length, internal radius r1, external radius r2, thermal conductivity k, whose inside and outside surface temperature are t1 and t2 respectively are given by: A_m=(2p(r_2-r_1))/(l_n r_2/r_1 ) (6 marks) b) Wet steam at 20 bar is carried in a steel steam mains of outside diameter 140mm, thickness 6mm and length 8m. The mains is insulated with an inner layer of diatomaceous earth 38mm, and an outer layer of magnesia 30mm thick. The inside heat transfer coefficient is 8.5 W/m2K and that of the outside surface lagging is 18W/m2K. The thermal conductivities of the diatomaceous earth, magnesia and steel are 0.09, 0.06 and 48W/mK, respectively. Determine: The rate of heat loss. The temperature of the outside surface of the lagging.
April 21, 2016
5:20 am
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