Abstract: A pipette tip storage and dispensing system has a series of pipette tip holder cards each of which has a plurality of openings for holding a set of pipette tips extending partway through the openings in an upright orientation. The openings in each card match those in the other cards, and cards loaded with pipette tips can be stacked vertically with the pipette tips in one card extending into the open upper ends of the tips in the next adjacent card of the stack, to minimize storage space. An alignment device is arranged to hold the pipette tips in a card in a vertical orientation as the card is removed from the top of the stack and transferred to a pipette tip holder tray so that the pipette tips can be lowered into aligned openings in the holder tray with the card resting on the top wall of the tray.

Abstract: A gas-cooled nuclear reactor includes a central core located in the lower portion of a prestressed concrete reactor vessel. Primary coolant gas flows upward through the core and into four overlying heat-exchangers wherein stream is generated. During normal operation, the return flow of coolant is between the core and the vessel sidewall to a pair of motor-driven circulators located at about the bottom of the concrete pressure vessel. The circulators repressurize the gas coolant and return it back to the core through passageways in the underlying core structure.If during emergency conditions the primary circulators are no longer functioning, the decay heat is effectively removed from the core by means of natural convection circulation. The hot gas rising through the core exits the top of the shroud of the heat-exchangers and flows radially outward to the sidewall of the concrete pressure vessel.