1). an electronic pid temperature controller is at steady state with an output of 10 ma. the set point equals the initial steady-state process temperature. at t = 0, the error signal is increased at the rate of 0.4 ma/min, which is equivalent to a rate of 2°f/min. if the current settings are kc = 3 (dimensionless), τi = 1.5 min, τd = 0.5 min, then (a) derive an expression for the controller output p(t) (b) repeat (a) for τd = 0 (a pi controller only) (c) plot the two controller outputs and qualitatively discuss their differences. (d) what is the transmitter calibration of ma/°f? (e) say after 1 min, the error signal went back to zero. what would p(t) be in that case?

Manometers are good examples of measuring instruments, nowadays they are not as common as before. a)-capacitive probe gauges b)-gravitational gauges deformation ) gauges d)-digital gauges

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

What is the major difference between thermoplastics and thermosetting plastics from the polymerization structure point of view?