Abstract: By providing a fluid flow chamber which is preferably constructed in an elongated, cylindrical shape and incorporates an elongated cylindrical sleeve in which an ultraviolet radiation producing lamp is positioned along the central axis thereof, with the outer surface of the sleeve covered with a unique coating layer, a highly efficient and low cost fluid purification system has been achieved which employs ultraviolet radiation. The unique coating material of the present invention allows the ultraviolet radiation to pass therethrough substantially unimpeded, while also virtually eliminating any buildup of light blocking deposits from the fluid on the surface thereof. As a result, the purification system of the present invention is capable of providing the desired high radiation level exposures for substantially extended periods of time without requiring repeated maintenance.

Abstract: A currency discriminator for determining the denomination of a bank note or the like is disclosed. It includes a source of light directed at the note to be identified. A 2 mm.times.80 mm stripe is illuminated and the reflected light from the illuminated area is measured by a detector and converted into a digital representation. Synchronizing hardware permits 72 samples, each from a 2 mm.times.80 mm area, to be generated as a bank note is moved past the illuminator. The digital representations are then utilized to develop a four bit correlation number N where each bit is a one if (P.sub.n >P.sub.n-2), (P.sub.n >P.sub.n-4), (p.sub.n >P.sub.n-6), and (P.sub.n >P.sub.n-8) where P.sub.n is the present sample and P.sub.n-2, for example, is the second previous sample. The correlation number N is then compared with the corresponding number in a master list for notes of different denomination.

Abstract: In order to perform pictorial pattern recognition at an extremely high data rate, a linear array of photodetectors reads information recorded on photograhic film and the data read is transferred sequentially to an array of microprocessors, converted into binary form and stored in the memories. The microprocessors operating in conjunction with transformation logic then perform successive transformations using an analysis technique, known in the art, which utilizes hexagonal surrounds.