Aone-dimensional slab without heat generation has a thickness of 20 mm with surfaces main- tained at temperatures of 275 k and 325 k. determine the heat flux through the system if it is constructed from (a) pure aluminum, (b) aisi 316 stainless steel, and (c) concrete.

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?