Problem 1. You are operating a batch bioreactor. At the stationary phase, you turn off the oxygen supply for 5 minutes, and then turn it back on. You obtained the following data from your experiment. What is the oxygen uptake rate and kla for your experiment? (Assume the solubility limit (C*) is 7.3mg/L and use graphing method to find kla)

Time (min) DO(mg/L)
1 3.3
Air off 0 3.3
1 2.4
2 1.3
3 0.3
4 0.1
Air on 5 0
6 0.3
8 1
9 1.6
10 2
11 2.4
12 2.7
13 2.9
14 3

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

The force on a cutting tool are 2600n vertically downward and 2100 horizontal. determine the resultant force acting on the tool and the angle at which it acts.

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.