Neumann peak

Figure 6, which is for the same simulation as Fig. 4, shows sectional averages of the pressure, particle velocity, and density as a function of position with the dashed lines denoting the initial values in the undisturbed crystal. These quantities peak at the front and then relax during the reaction and expansion behind the shock. The shockfront shape is in accord with ZND continuum theory for unsupported planar detonations, which predicts a von Neumann peak near the front followed by a reacting flow and a (Taylor) rarefaction wave. The peak pressure around 1.0 eV/A (Fig. 6, top), which corresponds to an effective pressure of approximately 400 kbar, and maximum particle velocity of 4.8 km/s (Fig. 6, middle) are consistent... 

The density profiles computed at different times of the simulation are plotted in Fig. 9, in a shock front reference frame. Each profile exhibits a peak with a similar shape followed by a decrease, which we associate to the von Neumann peak and ZND reaction zone. The constant shape (versus time) of this peak accounts for the steadiness of the reactive wave. Behind the... 

Von Neumann peak A narrow zone of high pressure behind the detonation front and ahead of the reaction zone. The pressure level is calculated from the shock-wave equations and the detonation velocity. 

Neumann, H., Peak-Chew, S.Y. and Chin, J.W. (2008) Genetically encoding N(epsilon)-acetyllysine in recombinant proteins. Nature Chemical Biology, 4, 232-234. 

Spike (or peak) pressure ahead of the detonation front was determined accdg to von Neumann theory. For this a linear extrapolation of the Us—Up data was conducted and assumption made that Us up relations represent nonreactive Hugoniots to the detonation velocities of expls... 

Detonation, Water Plexiglos Induced Shock Wove Velocity in. Cook et al (Ref 2) applied the "aquarium technique in the exptl detn of the equation of state for water Lucire. The results for water are compared with similar results by other methods. Measurements of the peak pressures in the deton wave are presented for RDX, RDX/salt, TNT HBX-1. Peak pressures were found to be the CJ or deton pressures of the thermohydro-dynamic theory. There was no evidence whatever for the "spike of the Zel dovich-von Neumann model even though conditions were such that this spike would have been detected by the method employed if it were present, at lease in the large diam, nonideal expls of max reaction zone length Refs.T) C. Fauquignon, CR 251, 38 (I960) 2) M, A. Cook et al, JAppl... 

The absolute values and temperature dependence of the calculated heat capacity (Cp ) agree well with the actual heat capacity of LaCrOs, which indicates that the heat capacity of those oxides can be estimated by Neumann-Kopp s theory. The heat capacity data of LaMnOs (Kobayashi et al., 1993), LaCo03 (Horinouchi et al., 1981), and Lai j Srj Co03 (Barkhatova, et al., 1990) measured by a laser flash method are shown in fig. 14. The heat capacities of LaMnOs and Lai-jcSr cCoOs show peaks due to the phase trairsition from orthorhombic to rhombohedral stracture, however, the heat capacity of LaCoOs shows complicated temperature dependence due to the magnetic phase transitions. 

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