Engine performance and crankcase lubricant viscosity were followed with 1:2 and 1:1 fuel mixtures of degummed soybean oil in No. 2 diesel fuel in tests with a John Deere 6-cylinder, 404 cubic in. displacement, direct-injection, turbocharged engine for a total of 600 running hours. A crankcase oil contamination problem resulting in an unacceptable thickening and a potential for gelling did exist with a 50/50 blend or a greater concentration of soybean oil, but it did not occur with the 1:2 blend. The data accumulated during the initial 600 hr running time indicates that a fuel blend of one-third degurnmed soybean oil and two-thirds No. 2 diesel (1:2 blend) may be a suitable fuel for agricultural equipment during periods of diesel fuel shortages or allocations. Additional data are being accumulated and will be analyzed in the future.

A threshold particle velocity criteria derived by E.R. Fitzgerald for the beginning of crystal lattice breakup and disintegration has been applied to shocked explosives and an inert material. In shocked explosives, reactions leading to detonation occur above a certain “threshold” magnitude. The computed crystal lattice breakup shock pressures compare rather well with observed experimental “threshold” shock pressures for six high explosives. The six explosives are: Comp‐B3, Comp‐B, TNT, PBX‐9404, Tetryl, and H‐6. In addition, the crystal lattice breakup criteria provides an explanation for the observed lowering of the detonation “threshold” shock pressure as the explosives are made more porous or less dense. Finally, the shock pressures, at which output from thermocouples embedded in shocked materials (PBX‐9404 and Plexiglass) increases dramatically, compare favorably with predictions based on crystal lattice disintegration criteria. Consequently, it is tentatively concluded that crystal lattice breakup, or self‐sustained phonon fission as Fitzgerald calls it, is responsible for the initiation of detonation in shocked explosives and enhanced thermocouple output in shocked materials. It is also postulated that the lattice breakup phenomena is also responsible for phase changes, increased chemical reactivity, and anomalous electrical activity which are observed in certain inert materials under relatively low level shock loading.