Abstract: An apparatus for feedback control in plasma processing systems using radical sensing, and a method for feedback control in plasma processing systems using radical sensing, the apparatus comprising at least one process gas supply system configured to output at least one process gas, at least one plasma source configured to receive the at least one process gas and generate at least one radical flow, at least one process chamber in communication with the at least one plasma source, wherein the process chamber receives the at least one radical flow and directs at least a portion of the at least one radical flow to one or more devices, the process chamber configured to output at least one process chamber output, at least one gas analyzer in communication with and configured to sample at least one of the at least one process gas, at least one radical flow, at least one radical flow within the at least one process chamber, and the at least one process chamber output, and at least one controller in communication with

Abstract: Optical assay device having an active receptive surface supported on a pedestal and held within a first container; the first container comprising first absorbent material located at the base of the pedestal, configured and arranged to absorb liquid draining from the surface, and having a second container, hingedly connected to one side of the first container, the second container comprising a second absorbent material, wherein the second container can be closed to the first container by rotation about the hinge, and wherein such closing causes the second absorbent material to contact the surface.