A server system for providing a plurality of virtual machines constructed on a physical machine with a physical resource is provided. A calibration operation is used to obtain a ratiometric difference between first and second series connected battery cells of the DC bus, which is indicative of a variance in their respective output voltages. Particularly improved results in fluid contacting processes can be achieved by enhanced mixing within a wicking layer within a microchannel. An insulating interlayer is formed that covers the conductive structures. 185d when a diameter of a torque transmission ball is represented by d.