Abstract: In a gas chromatograph a valve assembly for providing gradual, uninterrupted re-direction of gas flow between a flow measurement position and a bypass position. The valve assembly maintains constant gas flow through the chromatograph during transition between an auto-zeroing mode in which a flow sensor is calibrated and a flow measurement mode. The valve assembly includes a valve rotor having eccentric grooves formed for providing the desired re-direction of gas flow.

Abstract: A microscope slide receptacle system for positionably receiving and releasably holding specimen retaining microscope slides in a generally vertical disposition. The system includes a plurality of hinged first and second frames each frame comprising a generally inverted "U"-shaped changer and having complementary coupling hinges for inter-coupling multiple frames together to form the system. A releasable clip is fastened to the frame structure for engaging and supporting the slides. Each frame has a support hanger along the upper surface to permit coupling to a system support.

Abstract: An improved receptacle or holder for microscope slides used in scientific, medical or medically related procedures, with the receptacles being configured to positionably receive, hold and index microscope slides either vertically or horizontally by means of an articulated array of individual holders. The design further minimizes slide-to-cradle contact, with the configuration allowing for rapid drainage of liquids from the slide surfaces. The cradle is also configured to facilitate manual grasping of the edge surfaces of slides being held within the cradle.