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Sudden death as a result of cardiac arrhythmias can be induced in swine by combining precordial X-irradiation and an atherogenic diet. Hypothyroidism was not essential to the rapid induction of disease. We monitored the electrical activity of the heart during the terminal episode in 18 swine; 13 electrocardiograms showed ventricular fibrillation and 5 showed ventricular asystole. All 18 animals had advanced coronary atherosclerosis, and 14 had anatomically demonstrable myocardial infarcts. In a correlated separate experiment, ventricular fibrillation threshold was significantly lower in atherosclerotic swine. Infusion of lidocaine increased the fibrillation threshold 4-fold in these animals. This animal model appears to be useful for other investigations related to cardiac arrhythmias.

A simplified model is used for calculating the time-dependent velocity of polymeric fluid in an extruder. The flow properties of the fluid are characterized by a simple constitutive equation based on two parameters: a constant viscosity μ and a constant elasticity modulus G. It was found that the transient velocity fluctuates periodically, and the time tt needed to restore the steady-state velocity from a disturbance varies with the ratio G/μ and the dimensionless group ρH2G/μ2, where ρ is the density of the fluid and H is the screw depth of the extruder.

Improvements on, or alternatives to, the acrylonitrile melt retarding process were sought by three different approaches. First, trying to crosslink with halo-phosphorous compounds, and thus to combine melt and flame retardation holds excellent promise for an alternative process of meltproofing, but has not been found practical for flameproofing. Second, coating by inter facial polymerization. Time was not sufficient to elaborate all the many angles of this group of reactions. It was established that the basic method can be applied on a laboratory scale and does lead to meltproofing. An elaboration of this approach with a view to achieving simulta neous flame retardation is highly indicated. Finally, reactivating melt-retarding coatings for the anchorage of flameretarding agents. Promising leads uncovered were the copolymerization of acrylonitrile with methacryloylchloride, though the subsequent steps of anchoring a suitable chemical to the active acid chloride site has not been worked out.