Abstract: A display apparatus simulates a container of gaseous liquid. The display apparatus has a reservoir formed by closely spaced inner and outer walls, at least the outer wall being transparent or translucent and shaped to resemble the container. In use, a foamable liquid is held within the reservoir, and gas is introduced into the liquid at the bottom of the reservoir to thereby form bubbles which rise through the liquid and form a head of foam on the liquid. A foam regulating mechanism allows the gas from burst foam bubbles to escape from the reservoir, but returns the liquid component of burst foam bubbles to the reservoir. The display apparatus is suitable for simulating soda drinks, beer and other aerated beverages.

Abstract: A test sample card has a fluid passage network provided on both sides of the card to provide for maximum separation distance between adjacent growth wells. The card also has cored sections along its periphery adjacent the wells, which improve the flow of plastic during the molding of the cards. The cored sections control the formation of knit lines in the surface of the card and eliminate knit lines from forming that could potentially bridge adjacent wells. These features, singly and together, combine to produce a card that is essentially immune to cross-talk between adjacent wells, yet permit a greater number of wells in a card of given dimensions. Improved bubble trap features are also provided for the card, including a bubble trap passage having a restriction formed therein. The restriction prevents air bubbles in the bubble trap from migrating back to the growth wells.