Fragmented reaction zone

Figures 4.6—4.8 are the results for the stoichiometric propane-air flame. Figure 4.6 reports the variance of the major species, temperature, and heat release Figure 4.7 reports the major stable propane fragment distribution due to the proceeding reactions and Figure 4.8 shows the radical and formaldehyde distributions—all as a function of a spatial distance through the flame wave. As stated, the total wave thickness is chosen from the point at which one of the reactant mole fractions begins to decay to the point at which the heat release rate begins to taper off sharply. Since the point of initial reactant decay corresponds closely to the initial perceptive rise in temperature, the initial thermoneutral period is quite short. The heat release rate curve would ordinarily drop to zero sharply except that the recombination of the radicals in the burned gas zone contribute some energy. The choice of the position that separates the preheat zone and the reaction zone has been made to account for the slight exothermicity of the fuel attack reactions by radicals which have diffused into...

Interfacial carrier molecules are presented by their hydrophUic fragments in adjacent aqueous solutions and by their hydrophobic parts in an organic phase of a hquid membrane. Thus, the reaction can be treated as a homogeneous type occurring in an adjacent reaction zone instead of a heterogeneous adsorption-type reaction process. 

On the other hand, the characteristics of detonation, electric spark sensitivity, and thermal decomposition correlate with the N NMR chemical shifts of nitrogen atoms of the most reactive nitro groups. The basis of initiation by electric spark could lie in a thermal stimulus [35,39,52,53]. However, thermal stimuli cannot be considered in the process of detonation initiation by shock (also by impact) [115]. This also agrees with the finding that the detonation characteristics of energetic materials correlate with the characteristics of their low-temperature decomposition, which means that the primary fragmentation of polynitro compounds in their detonation transformation proceeds at milder conditions than those present at the front of detonation wave or in its reaction zone. That also means that the detonation transformation itself of the given substance should be preceded by an induction period [120]. 

Pyrolysis has had only a limited success in the study of lipids. The rapid heating and short residence times of the products in the reaction zone (Figure 8.1) often result in escape of intact or at most minimally fragmented lipids, e.g., complete fatty acids which are subsequently lost by condensation on the walls of the reaction chamber. Thus, lipid moieties tend to be strongly underrepresented in the pyrograms of lipid-containing samples. 

Only the coohmt has to be circulate, and the same tope free from fission fragments. A schedule of replace-circulation cools the reaction and absorption zones. No 65 ment can readily be worked out to keep the reactor gas is evolved from the reaction zone and poisoning fac- operating with minimum shutdown times, in accordance tors, due to retention of fission product neutron absorb- with the power output and resultant use rate of the ers in the reaction zone, do not become critical because plutonium. 

FIGURE 9.4-2 Matrix mineral fragment illustrating reaction zone and reacted and unreacted regions. 

The kinetics of the coalescence-fragmentation sequence in cascade reactors is unknown, but, obviously, droplets with very different compositions are present in a reaction zone. Hence, alkylates of different compositions are being produced in different droplets in each zone. In addition, part of the hydrocarbons in the droplets is vaporized to maintain the desired temperatures. Most, but not all, of the heats of reaction and of the energy supplied by the agitators are removed. A small temperature rise occurs from one zone to the next as indicated by Ackerman and co-workers (8). In one case, the temperature increased from 1.2°C in the first zone to 6.4°C in the 10th zone. These temperatures are lower than those normally used in Stratco reactors. The average quality of the alkylates in this... 

A detonation-fine fragmentation model to calculate the rapid fragmentation and steam generation in a propagating reaction zone. 

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