The following data are from total solids and total volatile solids tests on a wastewater sample. Calculate the total and volatile solids concentrations in milligrams per liter. Weight of empty dish = 68.942 g Weight of dish plus dry solids = 69.049 g Weight of dish plus ignited solids = 69.003 g Volume of wastewater sample = 100 ml

Apreheater involves the use of condensing steam at 100°c on the inside of a bank of tubes to heat air that enters at 1 atm and 25°c. the air moves at 5 m/s in cross flow over the tubes. each tube is 1 m long and has an outside diameter of 10 mm. what is the minimum value of nl needed to achieve an outlet temperature of t 75 c? what is the corresponding pressure drop across the tube bank?