Abstract: The dispenser and rack for a roll of paper, plastic, or foil, which comprises a magazine for generally vertical disposition having an open bottom, and the inside dimensions of the magazine are sufficient to accommodate at least one roll. A paddle is mounted in the magazine, and a handle affixed to the paddle extends from an opening in the magazine and is free to be moved along the opening so as to actuate the paddle between a lower-most position and an upper-most position. The paddle is arranged so when in its lower-most position, it obstructs the open bottom so as to prevent a roll from dropping from the magazine; and when the paddle is actuated to its upper-most position, clearance is provided to allow a roll to drop from the magazine. A suitable bracket depends from the magazine beneath the open bottom, and the paddle allows one roll a time to drop from the magazine for engagement with the bracket, and is revolvedly mounted on the bracket, thereby exposing the roll for use.

Abstract: Properties of thin films are monitored in real time by measuring the interactions of the light from an injection laser diode with the thin film adjacent to one of the facets of the laser diode by an associated photodetector. Thickness, index of refraction and other properties can be measured as a function of the output power, slope efficiency and threshold current of the laser diode.

Abstract: A heater which burns agricultural waste as its heat source includes a combustion chamber for the waste having a bottom opening, a grate for supporting the waste, an access lid at the top and an air intake at or adjacent the top. The bottom opening is connected to an exhaust system which includes a fan for creating a downward draft in the combustion chamber causing the exhaust gas stream to leave the chamber at the bottom opening. The exhaust system also includes elements for the removal of solid combustion products from the exhaust stream and for regulating the temperature of the exhaust stream which is then usable for heating purposes.