Serratia marcescens bacteria are used for the production of threonine. The maximum specific oxygen uptake rate of S. marcescens in batch culture is 4 mmol O2 g-1 h-1. It is planned to operate the fermenter to achieve a maximum cell density of 50 g l-1. At the fermentation temperature and pressure, the solubility of oxygen in the culture liquid is 8 × 10-3 kg m-3. The concentration of oxygen in the culture liquid is 0.5 × 10-3 kg m-3. At a particular stirrer speed, kLa is 0.17 s-1. Under these conditions, will the rate of cell metabolism be limited by mass transfer?

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature

Which of the following refers to refers to how well the control system responds to sudden changes in the system. a)-transient regulation b)- distributed regulation c)-constant regulation d)-steady-state regulation