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A study of the relationship of dispersant effectiveness and mixing energy was performed. Energy was varied by changing the rotational speed of a specially designed apparatus. The effects of dispersant type and oil type were also measured. The stability of the resulting emulsions was gauged by measuring the amount of oil that remained in the water column over time. The findings are that each oil-dispersant combination shows a unique threshold or onset of dispersion. The effectiveness goes up linearly with energy, expressed as flask rotational speed. Natural dispersion was also measured and shows behavior similar to that of chemical dispersion, except that the thresholds occur at a higher energy and effectiveness rises more slowly with increasing energy. Effectiveness (defined as the percentage of oil in the water column) rises rapidly to 80 to 90 percent with increasing energy for light oils treated with chemical dispersants. Heavier oils will disperse, but to lesser effectiveness values.

In this paper we present the nonlinear effects we obtained so far through ferromagnetic-transmissionresonance experiments in iron and nickel. The experiments were performed in the geometry in which both the applied and microwave fields are mutually parallel and also parallel to the sample surface at the input cavity. In this geometry, we have found two interesting transmitted waves through ferromagnetic samples several microns thick. One is polarized parallel to and has the same frequency as the applied microwave field. The other, polarized perpendicular to the applied field, has a frequency half that of the applied field and is generated in the ferromagnetic sample. The results are compared to the nonlinear theory presented in the previous paper. The agreement between the experimental and theoretical results is reasonable. The theory shows that the nonlinear phenomena are very sensitive to the exchange stiffness constant. It is thus hoped that these phenomena will be useful in determining the exchange stiffness constant, and ultimately the exchange integral, as a function of temperature. Further, they might provide new information on spin-relaxation processes.

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