Raman histogram

The data plotted in Fig. 8 were taken near the flame boundary, 50 fuel-tip diameters downstream, with no optical background corrections made to the vibrational Raman raw data. With such corrections, the data appear as in Fig. 9. (It is these data that are plotted in Fig. 4 in the top histogram, corresponding to r = 14.5 mm.) Similarly, Figs. 10 and 11 show data taken near the flame axis the data in Fig. 11 appear in Fig. 4 in the bottom histogram, corresponding to r = 1 mm. What do we learn from these plots ... 

The normal-mode calculation produced 597 frequencies and eigenvectors. We represent the former in Fig. 33 by giving a histogram of the calculated frequencies below 1700 cm", plotting the number of normal modes in each 5-cm interval. Such a density of vibrational states, which can be probed by inelastic neutron scattering (Jacrot et al., 1982), is not observed directly by IR or Raman. As we noted, and will consider further below, the IR spectrum is determined by the dji/dQ in each normal mode, which remains to be calculated. Since hydrogen bonding and TDC have also not been included in this calculation, the values of the amide frequencies and the distribution of the low-frequency modes cannot be considered finalized as yet. 

Figure 11.1 Raman images created as integrated intensity maps (1310-1350cm ) from Raman maps of an acetaminophen crystal recorded at net acquisition times of (a) 100ms (red) (b) 1 s (green) and (c) 2s (blue) per spectrum Figure 11.2. The histogram of each Raman image (x-axis, Raman intensity in arbitrary units y-axis, number of spectra) is displayed next to each Raman image.

Figure 11.12 A histogram of a Raman image. Total number of spectra = 6561 mean score = -0.35 standard deviation of scores = 1.3 skew of scores = 1.3 kurtosis of scores = 1.4.

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