Abstract: A rotary Wankel-Stirling machine operating upon a compressible working fluid, having a rotary expander having a hot side housing with a heat input interface, a hot side rotor having rotor passages adapted to allow passage of the working fluid between the rotor hub and rotor face, heated chambers formed between the rotor face and the hot side housing, a rotary compressor having a cold side housing with a heat rejection interface, a cold side rotor having rotor passages adapted to allow passage of the working fluid between the rotor hub and rotor face, cooled chambers formed between the rotor face and the cold side housing, a shaft, adapted to rotatably couple the rotor hub of the hot side rotor and the rotor hub of the cold side rotor, the shaft having shaft passages adapted to allow passage of the working fluid between the heated chambers and the cooled chambers, and the working fluid sealed in the machine, wherein the machine operates under the Carnot cycle.

Abstract: A method and mechanism for performing a spatial join between two sets of objects employs a two-pass primary filter. The objects are decomposed into variable-sized cells no larger than a predetermined cell size and stored in respective spatial indexes. The spatial indexes include a code for the variable-size cells of the object and a code for the fixed-size supercell of the variable-size cells. The first pass can be implemented as an equijoin filtering operation using the fixed-size cell codes corresponding to the predetermined cell size, and the second pass as a join operation using the variable-size cell codes at smaller cell sizes.