It is proposed that a non-polar filler can reduce interfacial energies between polar and non-polar polymers. Experiments have been carried out to test this hypothesis using carbon black as the filler in blends of natural rubber (NR) and a nitrile rubber (NBR) with an acrylonitrile content of 45%. Blends of NR-NBR (70/30) were prepared in an internal mixer with varying amounts of carbon black. The dramatic decrease in domain size on addition of carbon black was nonetheless lower than that predicted. Further experiments showed that the amount of carbon black available at the interface for compatibilisation was influenced by preferential incorporation into the lower viscosity elastomer (NBR). Thus, elastomers of similar viscosity should be added to the mixer prior to the carbon black in order to maximise the amount of 'free' unwetted carbon black present when the elastomers are blended together. Blending experiments carried out under these conditions resulted in a morphology close to the prediction based on thermodynamic theory.

The following is a short note reporting preliminary experimental work designed to test the feasibility of simulating early diagenetic changes in Recent carbonates. Two experiments are reported; one lasted a period of 3 months and the other for a period of 6 months. In both cases, samples of Recent ooids, split from a single sample taken from the Schooner Cays tidal belt, off Eleuthera Island, Bahamas, were held in a constant temperature/pressure regime in the presence of standard sea water.

Much published literature on the way in which phase morphology and filler distribution affect blend properties is contradictory or confusing. Experiments were carried out to elucidate the relationships and to determine whether the use of compatibilizers or special mixing techniques might have a beneficial effect on natural rubber:butadiene rubber (NR:BR) blend properties. NR:BR blends were prepared using both a masterbatch method and a single-stage mixing method. A cure system which gave an even distribution of crosslinks between the phases was used. The morphology, tensile strength and tear strength properties of the blends were measured. Results indicated a high degree of compatibility with fine textured blends (domain sizes < 1µm) being quickly and easily produced, even from masterbatches of very different viscosities. Strength properties of these fine textured masterbatch blends could be predicted by applying the simple rule of mixtures to properties of individual compounds mixed under the same conditions. Although in particular situations a coarse morphology could result in high tear resistance values, for most applications a fine textured morphology gives the most satisfactory overall tensile and tear strength properties. For blends mixed in a single-stage process, development of a fine textured morphology was much quicker than that of filler dispersion. For NR:BR blends containing an optimum cure system it was concluded that the mixing cycle should be chosen to optimize filler dispersion and that use of a compatibilizer will not significantly shorten the mixing cycle or improve the properties of the blend.

The reluctance of top managers to use computers themselves has become almost legendary, although there are good reasons for their apparent preference for traditional information sources and access routes. Isolated cases have shown how computer-based executive support systems can be used by top managers when great care is taken by the system developers over data presentation and the user interface. Now, the advent of high quality commercial software means that Executive Information Systems (EIS) may become far more widespread. This paper describes the principal features of the new EIS from the executive users' point of view and indicates those characteristics which appear to be most conducive to success. Research directions which will identify the extent and impact of EIS software on top management are identified.

The results of a number of experiments simulating the early diagenesis of carbonate ooids are presented and discussed. consideratin of both inorganic and organic reactions indicate that the presence and maturation of organic matter i scritica. It is suggested matter, while the inorganic reactions are likely to be controlled by the by‐products of the maturation of the oraganic matter. In gernral the results obtained show a marked similarily to the geilogical situation.