No abstract

Abstract--This work deals with the characterization of two-phase flows based on fractal techniques in order to develop objective flow regime indicators. Fractal analysis has been used previously for studying turbulent flows and it is a natural way of describing highly irregular fluctuations in two-phase flows. The fractal dimension of measured time series have been evaluated by Higuchi's method. It is shown that the error of the linear fit of the fractal dimension is a sensitive indicator of the changes in the flow regime, while the fractal dimension value itself is less suitable for flow regime identification. The developed method has been applied to the evaluation of two-phase flow experiments at the SIDAS boiling loop at Delft

Saccharomyces cerevisiae CBS 426 was grown aerobically in continuous culture with a mixture of glucose and ethanol as the carbon source. The flows of biomass, glucose, ethanol, oxygen, and carbon dioxide were measured. A model for growth with two substrates was derived. Application of this model to the above-mentioned system yielded values for Y and P/O. The joint confidence regions for these parameters were calculated. The relevance to industrial production of bakers' yeast is discussed.

SummarySaccharomyces cerevisiae CBS 426 was grown aerobically and anaerobically in a glucoselimited chemostat. The flows of biomass, glucose, ethanol, carbon dioxide, oxygen, glycerol, and the elemental composition of the biomass were measured. Models for anaerobic and aerobic growth are constructed. Values for YA,p and P/O are obtained from continuous culture data for aerobic growth; this Y A~p value is compared with that obtained from the anaerobic growth results. The ratio between the heat produced and the oxygen consumed increases if more glucose is fermented to ethanol and carbon dioxide. An equation for c $~/ $0 as a function of the respiratory quotient is given.

No abstract