Abstract: A dental support structure for crown restoration which may be screwed into a hollow dental implant. The support structure has a stem which is adapted to receive a crown and which is moveable along the axis of the support structure in resistance to spring pressure and whose axis may tilt without substantial resistance from said spring pressure.

Abstract: An electromechanical demonstrator board of one or more of the six trigonometric functions. The board is powered electrically by a battery and mechanically by a hand crank which drives a pointer and contact arm. The circuits include light emitting diodes (LEDs) arranged into three groups. The first group represents a unit circle. The second group is on a vertical segment, and the third group is on the path of the function and the horizontal axis. The first group of LEDs indicates particular angle measures on the unit circle. In the second group, vertically oriented LEDs indicate harmonic motion. The third group of LEDs demonstrates a graph of the trigonometric function and the measure of linear movement related to rotation on the unit circle.

Abstract: A drinking water distribution system for poultry is disclosed providing poultry such as turkeys and chickens with fresh clean drinking water. The system utilizes gravity feed to distribute water from a reservoir through a conduit to a series of water cups connected to the conduit in open communication with the conduit and extending upwardly therefrom. The conduit and reservoir are suspendingly supported above the floor of the poultry house by cables depending downwardly from overhead portions of the poultry house and connected to a winch so as to be easily raised to a suitable height to accommodate growth of the poultry. The system further monitors the water temperature and if the temperature of the water gets too warm, the system replaces it with water of a lower temperature. The invention further includes an arrangement for periodically purging and cleansing the system by replacing the drinking water with liquid disinfectant for a predetermined dwell period.