Extinction profile limitations

A sufficiently high inlet velocity will cause the flame to be extinguished [270]. There are two reasons for the extinction. One is heat loss to the wall, which reduces the flame temperature and hence the chemical reaction rates. The second, and perhaps less obvious, is strain extinction. As the inlet velocity increases and the boundary layer thins, the radial velocity increases (the general shape of the radial velocity profiles are shown in Fig.6.6). As the radial velocity increases, the residence time in the flame zone also decreases. The reduced residence time, in turn, limits the time available for the relatively slow radical-recombination reactions to keep the flame temperature high. Reduced temperature and residence time limit the relatively slow the chain-branching reaction H + O2 OH + O, which is needed to sustain a flame. Ultimately a flame cannot be sustained [214],... 

Knowledge of soil surfaces is still very poor, as there is limited information on basic parameters such as light intensity profiles in the soil, extinction coefficients and reaction quantum yields. Because light intensity decreases... 

The electronic plasmon absorption of a 6 nm Ag island film is shown in Figure 3. In the same figure, the extinction cross section calculated for a silver sphere and a silver prolate with a 3 1 aspect ratio, within the long wavelength limit of Mie theory, are included for comparison. The computation clearly illustrates the considerable shift to the red of the main plasmon absorption of the prolate spheroids in reference to the silver sphere. The broad plasmon absorption indicates a large distribution of sizes and shapes of Ag nanoparticles, and has a maximum at 494 nm. Notably, the SERS excitation profile follows closely the measured plasmon absorption, confirming the EM nature of the observed enhanced intensities. ... 

---