Pseudo first order reaction kinetics

From this work, it is apparent that the inactivation of DPP IV by u and / nitrile does not follow pseudo-first-order reaction kinetics. The inactivation process is dependent principally on inhibitor concentration, and only slightly changes with incubation time. Secondly, the inhibitory potency of inhibitor u and / nitrile is nearly equivalent (for u K, = 6.03 pM and for /K = 7.69 pM), that is, the inhibitors interact with DPP IV relatively little difference in potency. K of both u and / are four to five times lower than Ala-Pro-NHO-Bz(4-N02). Both u and / nitrile exhibit superior inhibitory activity to the previously prepared Ala-Pro-NHO-Bz(4-N02) compound. Surprisingly both the u and / nitrile have superior activity to mechanism based Alai/ [CF=C]-Pro-NHO-Bz inhibitor. 

The data in Figure 7.13 show reductive-dissolution kinetics of various Mn-oxide minerals as discussed above. These data obey pseudo first-order reaction kinetics and the various manganese-oxides exhibit different stability. Mechanistic interpretation of the pseudo first-order plots is difficult because reductive dissolution is a complex process. It involves many elementary reactions, including formation of a Mn-oxide-H202 complex, a surface electron-transfer process, and a dissolution process. Therefore, the fact that such reactions appear to obey pseudo first-order reaction kinetics reveals little about the mechanisms of the process. In nature, reductive dissolution of manganese is most likely catalyzed by microbes and may need a few minutes to hours to reach completion. The abiotic reductive-dissolution data presented in Figure 7.13 may have relative meaning with respect to nature, but this would need experimental verification. 

In these reactions, the radical concentrations are typically much lower than the concentrations of the substrate (S) molecules (or ions), and the reaction kinetics follow pseudo-first order-reaction kinetics ... 

Bimolecular quenching reactions of excited states are typically represented by the pseudo-first-order reaction kinetics, equation 6a. When a distribution of probe environments exists, the difference between the macroscopic fluorescence decay profile observed and microscopic fluores-... 

The elimination of MTBE by the UV/Ti02 process follows pseudo-first order reaction kinetics [105]. The limiting step of the reaction is the adsorption of MTBE onto Ti02 surface where OH radicals are generated. Dark experiments showed that after 1 h less than 10% MTBE are adsorbed on the surface and saturation was achieved [89,93]. The adsorption equilibrium is... 

MTBE is eliminated with pseudo-first order reaction kinetics [108-111]. The reaction rate is dependent on the frequency and power density of the ultrasound. At higher frequency, the elimination of MTBE is much faster. For each frequency the power density shows an optimum, since the interaction of and influence on cavitation bubble size, collapse time, transient temperature and internal pressure is very complex. Initial MTBE concentration was also observed to be of influence the reaction rate decreased with increasing MTBE concentration. This indicates that the reaction is limited by OH radical diffusion. 

However, under conditions where there is a large excess of water, pseudo-first-order reaction kinetics can be observed. The expression now simplifies to ... 

The thermal decomposition of DNQs in novolac resist film follows pseudo first-order reaction kinetics (see Fig. 11.23.). The 2,1,4-DNQ PAC is more... 

Bimolecular quenching reactions of excited states are typically represented by the pseudo-first-order reaction kinetics, Equation (30.6a). When a distribution of probe environments exists, the difference between the macroscopic fluorescence decay profile observed and microscopic fluorescence decay rates present must be recognized. The composite distribution of both unimolecular decay rates and the respective bimolecular reaction rates are combined in the distribution of observable decay rates. Hence, the parameters in Equation (30.6a) have to be redefined in the Gaussian distribution terminology to yield Equation (30.6b). 

Chin et al. (2007b) used pseudo-first order reaction kinetics combined with the ideal continuous stirred tank reactor (CSTR) model to evaluate the effect of initial concentration of pollutant on the performance of a submerged membrane photocatalytic reactor for the degradation of bisphenol A in water (Equation [21.2]) ... 

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