Oxygen uptake kinetics

It is assumed that oxygen transfer takes place only in the vicinity of the impeller, hence only in the micromixer. A mandate for such a handling of oxygen-uptake kinetics has been presented by Bajpai and Reuss (8) and by Reuss et al. ( ). 

The assumptions behind such a representation of oxygen uptake kinetics in a viscous fermentation broth and their explanations are given by Reuss et alk (9J. 

Figure 2. Predicted gross oxygen uptake kinetics for different reactor circulation time distributions corresponding to a mean circulation time (t) of 10 s.

Devol, A. H. (1978). Bacterial oxygen uptake kinetics as related to biological processes in oxyged deficient zones of the oceans. Deep Sea R S. 25, 137-146. 

As it is seen from Figure 10(b), tlie formation of stabihzed radicals occurs with pronounced induction period which is related to antioxidant properties of MWNCT. Such a type of kinetic dependence is coincided with an oxygen uptake kinetics observed during inhibited polyolefines thermal oxidation. Moreover, no EPR signals were observed in the samples of the PP/MCWNT samples heated at 350°C in inert Ar. 

Oxidation is the main cause of the rapid destruction of PP during its service and processing. The oxidation of polyolefins proceeds by the radical chain mechanism with degenerate branching on hydroperoxide [15], It is known that, at the initial stage of uninhibited oxidation of polyolefins, the oxygen uptake kinetics is described by the parabolic law ... 

Subsequently one plots InNo vs tHe and extrapolates to tHe=0. This plot provides the 02 desorption kinetics at the chosen temperature T. The intersect with the N0 axis gives the desired catalyst surface area NG (Fig. 4.8) from which AG can also be computed. More precisely NG is the maximum reactive oxygen uptake of the catalyst-electrode but this value is sufficient for catalyst-electrode characterization. 

Figure 2. Estimated rates of oxygen uptake by samples of silica-supported PVl (circles), PV3 (triangles) and PV14 (diamonds). Approach to saturation was modeled as either first-order kinetics (solid line, x =0.054) or second-order kinetics (dashed line, y =0.585).

Rates of oxygen uptake in the dynamometer-aged catalysts are consistent with published oxidation kinetics of l- m-thick Pd films. 

Comparison of chemiluminescence isothermal runs with oxygen uptake and DSC measurements has been at the centre of interest since practical industrial applications of the chemiluminescence method were attempted. It is a fact that the best comparison may be achieved when studying polymers that give a distinct induction time of oxidation typical for autoaccelerating curves of a stepwise developing oxidation. This is the particular case of polyolefins, polydienes and polyamides. The theoretical justification for the search of a mutual relationship between the oxidation runs found by the various methods follows directly from the kinetic analysis of the Bolland-Gee scheme of polymer oxidation. 

When all the dioxygen consumed appears in hydroperoxide groups and the number of decomposed hydroperoxide molecules is low, the kinetics of oxygen uptake can be described by the following equation [3],... 

Like the oxidation of hydrocarbons, the autocatalytic oxidation of polymers is induced by radicals produced by the decomposition of the hydroperoxyl groups. The rate constants of POOH decomposition can be determined from the induction period of polymer-inhibited oxidation, as well as from the kinetics of polymer autoxidation and oxygen uptake. The initial period of polymer oxidation obeys the parabolic equation [12]... 

The rate of dissociation has been measured by oxygen uptake in the presence of an inhibitor of chain reactions as in the case of hexaaryl-ethanes. Since the uptake of oxygen obeys the same kinetic law, it is a reasonable extrapolation to suppose that here too the rate-determining step is a dissociation into radicals. When one of the phenyl groups in triphenylmethyl is replaced by a cyclohexyl group, the rate of dissociation of the ethane is reduced by a factor of 170.38 Some dissociation rate parameters are given in Tables III A and B. 

Figure 3.The kinetics of oxygen uptake by deformed PP samples at deformation degree X = 0 (1), X =...

Degn, H., Lundsgaard, J. S., Peterson, L C., and Ormicki, A., Folarographic Measurement of Steady State Kinetics of Oxygen Uptake by... 

Steady State Kinetics of Oxygen Uptake by Biological Samples, Polarographic... 

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