Quarterly report of the Argonne National Laboratory Chemical Engineering Division regarding activities related to properties and handling of radioactive materials, operation of nuclear reactors, and other relevant research.

We report on experiments run on a set of shared-memory multiprocessors. Our goal was to demonstrate that one could conveniently utilize a set of shared-memory multiprocessors cooperatively working on typical state-space searches. We utilized a technology for writing portable code for multiprocessors, coded three depth-first state-space searches, and ran them on a set of multiprocessors. The final problem used substantial resources (over 65 hours on a single processor) and was successfully distributed over four distinct shared memory multiprocessors (2 Sequents and 2 Encores), reducing the time to perform the computation to slightly over 2 hours.

The domain and surface structures of metallic sodium tungsten bronzes, NaxWO₃, 0.4 < x < 1, were studied using optical microscopy, supplemented by chemical methods, photoelectron spectroscopy, electron microscopy, etc. The birefringent, multidomain structure of the bronze is exhibited by a sodium-deficient, epitaxial surface film and hence is not, as reported elsewhere, a bulk property. The film can be synthesized by anodic electrolysis in alkaline solution and can exist only epitaxially with the substrate. It is chemically inert, translucent, and often laminated to a multilayered film. The film domain is hypersensitive to lateral stress and to thermal change, and appears to be modulated by minute structural changes of the substrate. This epitaxial modulation of the film is strikingly large at the phase transitions of the substrate induced by slightly different tiltings of the oxygen octahedra. The domain-wall movement is often slow enough to be visible, and that by thermal effect is occasionally accompanied by an audible, high-pitched, snapping sound.

This sixth symposium covers process control processes and issues involved in the conversion of fossil fuels into synthetic fuels.