Evolutionary Computation Applications: Twelve Lessons Learned

A liquid transfer rotary valve assembly capable of measuring and delivering at least a pair of different sample volumes in the microliter range along with a predetermined volume of diluent as a pair of different dilutions directed to different locations. The valve assembly provided herein includes a pair of stationary outer disc members and a movable inner disc member sandwiched therebetween, the facing surface portions being sealingly frictionally engaged. Each disc has an axial central passage to accommodate a spindle. An external hollow loop is provided on one of the stationary discs having a precise volume in the microliter range. A segmenting passageway is provided on the movable inner disc member. A source of sample is communicatively coupled through the other stationary disc to the segmenting passage which is arranged in series with the external loop. After a continuous stream of sample is disposed through the serially connected segmenting passage and loop, the inner member is angularly moved to place the content of the segmenting passage in communication with a source of diluent and a passage leading exterior of the valve. Reverse angular movement of the valve element enables backwash through the valve subsequent to delivery.