An imaging-type interferometric optical profiler splits a beam reflected from a sample into two beam portions. Microchannelelectrokinetic pump cooling systems utilize active cooling technology to reduce thermal gradients and operating temperature of a microelectronic die. The node B confirms that it has received the grant signal from the node C, and after that, changes its state from the wait grant state to a wait idle state where the node B transmits an idle signal to the node C, and waits until the grant signal from the node C changes into an idle signal. Instead of keeping or recovering snapshots of the entire dataset which requires the entire cluster, the DCBR system identifies the particular nodes andor archive files where the dataset resides so that backup or recovery may be done with a much smaller number of nodes. The flow restriction section may be a narrowed section of the longitudinal passageway, in which an upstream side of the flow restriction section may have compressed air at substantially the compressor discharge pressure and a downstream side may have air at a lower pressure and a higher velocity. The opening of the second container is generally equal in size to the opening of the first container.