A single stage continuous culture of Corynebacterium glutamicum bacteria is conducted in a 200 L stirred fermenter, at 30oC. The reactor is sparged with a gas mixture of 63% oxygen and 37%
nitrogen at a rate of 1 VVM (Volume/Volume. min) at room temperature. Average pressure in the
fermenter is 1 atm. Volumetric flow rate of off-gas from the fermenter is 189 L min–1. Exit gas
stream from the fermenter has been analysed and found that it contains 52% O2.
a) What is the oxygen transfer rate?
b) If the maximum specific oxygen uptake rate of the microorganism is 5.10-3 g L-1 s-1, is the
cell growth in the fermenter limited by mass transfer? Explain shortly.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way