The dynamic response of a stirred-tank bioreactor can be represented by the transfer function C′ (s) C′ F(s) = 4 2s + 1 where C′ is the exit substrate concentration, mol/L, and C′ F is the feed substrate concentration, mol/L. (a) Derive an expression for c′ (t) if cF(t) is a rectangular pulse (Fig. 5.2) with the following characteristics: cF(t) = ⎧ ⎪ ⎨ ⎪ ⎩ 2 t < 0 4 0 ≤ t < 2 2 2 ≤ t < [infinity] (b) What is the maximum value of c′ (t)? When does it occur? What is the final value of c′ (t)? (c) If the initial value is c(0) = 1, how long does it take for c(t) to return to a value of 1.05 after it has reached its maximum value? 5.5 A th

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Wiy doeres rere okhn a pump whon working betwon the same pressure range?