A laboratory reactor with a reaction vessel for receiving media or substances to be processed has devices or units for processing or mixing media or components and for measuring, the devices or units being able to engage in the reaction vessel or reactor vessel from above or below. In order to prevent evaporation of the ink through the nozzles of the printhead, and the consequential depositing of ink components in and around the ink nozzles, the invention provides capping of the nozzle during the non printing modes of the printer. The game pieces are shaped like miniature racecars and are meant to represent actual Nascar racecars. A current-carrying electrode of a particular transistor includes the first doped region and is a source or an emitter and is electrically connected to the buried conductive region. A suction passage is formed along an outer periphery of the cylinder corresponding to a peripheral direction of the cylinder chamber.