Following suggestions from the literature that, in some cases, mud flow and debris flow may be treated in computations as viscous laminar flow, this paper contains test results compared with results obtained with a one-dimensional numerical model of a high-viscosity fluid wave on an inclined bottom. A gate that initially retained the fluid at the upstream end of a channel was quickly removed. The set up of the numerical model is discussed in detail. A finite difference scheme is applied. Viscous bottom friction is counted for. To overcome the discontinuity at the start of the break, the classical analytical solution of the zero-viscosity dam break wave on a horizontal bottom is introduced. RÉSUMÉComme Ie suggèrent certains auteurs, il est possible d'envisager, dans certains cas, un traitement informatique des écoulements de boue et de débris comme s'il s'agissait d'écoulements visqueux laminers. Ce travail présente des résultats expérimentaux qui sont compares a une modèle numérique unidimensionnel représentant une onde de fluide de haute viscosité sur un plan incline. L'expérience simulée commence par l'ouverture rapide d'une vanne qui retient Ie liquide visqueux. Le modèle est presenté en détail. Le schema des differences finies est mis en application. Le frottement sur le fond est pris en compte. Pour surmonter le problème de la discontinuité, on a fait appel a la solution analytique classique de Tonde de rupture de viscosité nulle sur un fond horizontal.

Oxidation of lipids in fish meal has been studied. The course of the reaction has been followed by means of oxygen absorption, peroxide values and chromatographic analyses. The latter has been used quantitatively, because the method of methylation of the unreacted fatty acids obtained by hydrolysis of the glyceryl esters has proved to be quantitative. The results indicate: (a) there are other oxygen-consuming reactions which account for up to 10 times the oxygen consumed by simple peroxidation of the polyunsaturated lipids; (b) increasing moisture content has a marked prooxidant effect in all the oxidative reactions; (c) the overall rate of reaction is apparently independent of the peroxide concentration in the lipid, possibly due to the fact that there is some resistance to the diffusion of oxygen which produces deviations from the normal autocatalytic path of the reaction occurring when oxygen is fully available. 56 25 j: J J J

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