Only an outer panel is being replaced. Technician A says that removing the spot welds by drilling through both panels allows the plug welds to be made through the replacement outer panel. Technician B says that placing a metal tab between panels may help prevent cutting into the flange. Who is right

Estimate the change in specific internal energy au and specific enthalpy h from inlet to outlet for ethylene glycol (a liquid) flowing through each of the following devices: (a) a heat exchanger where the glycol temperature increases from 20 °c to 80 °c; (b) a pump operating at about 25 °c and increasing the glycol pressure from 100 kpa to 8 mpa.