What are some effective ways of controlling mold temperature and mold build up?

Which from the following instrument is commonly used to detect the high pitch butzing sound in bearings? [clo4] a)-digital ultrasonic meter b)-infrared camera c)-spectroscopic d)-vibrometer

Agas mixture consists of 8 kmol of h2 and 2 kmol of n2. determine the mass of each gas and the apparent gas constant of the mixture.

The characteristic roots of a dynamic system are: 1.7920 1.8160 i, -1.7920 1.8160 i, -0.4160 what is the order of this system? what are the settling time and damping ratio of the system?