Subject index dispersion

Robert V. Macbeth Gas-Liquid Dispersions William Resnick and Benjamin Gal-Or Author Index—Subject Index... 

Lubricants. Petroleum lubricants continue to be the mainstay for automotive, industrial, and process lubricants. Synthetic oils are used extensively in industry and for jet engines they, of course, are made from hydrocarbons. Since the viscosity index (a measure of the viscosity behavior of a lubricant with change in temperature) of lube oil fractions from different cmdes may vary from +140 to as low as —300, additional refining steps are needed. To improve the viscosity index (VI), lube oil fractions are subjected to solvent extraction, solvent dewaxing, solvent deasphalting, and hydrogenation. Furthermore, automotive lube oils typically contain about 12—14% additives. These additives maybe oxidation inhibitors to prevent formation of gum and varnish, corrosion inhibitors, or detergent dispersants, and viscosity index improvers. The United States consumption of lubricants is shown in Table 7. 

The McReynolds data were standardized and subjected to principal component analysis by several groups of workers who were able to reduce the data to three statistical components. Burns and Hawkes42 further refined the calculations to produce four quasi-theoretical indices that measure dispersion, polarity, acidity, and basicity. Hawkes has described this process in a more recent paper43 in which his group confirmed and refined these calculations with spectroscopic measurements. In addition to justifying their approach, they provide four indices for each of the 26 common liquid phases that were identified earlier as being the most important.36 The dispersion index is calculated from refractive indices, but the other three indices are based at least partially on chromatographic data. 

The majority of results so far available in this Held have been derived from spectra recorded on dispersive instruments. In order to test tl validity of Eq. (1) several independent experiments have been performed in which a highly oriented polyethylene terephthalate film is subjected stepwise to increasingly higher stresses in the stretching machine illustrated in Fig. 1 and FTIR spectra are taken at the relaxed stress levels with unpolarized radiation. In Fig. 4 the wavenumber shifts of the v(0—CH2) absorption band are plotted as a fimctimi of the applied stress for different experiments. From these systematic investigations, however, no linear relationship between the wavenumber shift Av and the plied stress good index of determination (0.98) was obtained for the power function ... 

Although the relative band intensities of ATR spectra that have been subjected to the ATR correction are similar to those of the corresponding spectra measured in transmission, they are not the same because of the effect of anomalous dispersion (i.e., the variation of refractive index across an absorption band see Section 1.5.2). Let the refractive index, 2, of the optically rare material (the sample ) in spectral regions where there is no absorption be ave. Because 2 is smaller than Wave at higher wavenumbers than the band center, Vq (see, e.g.. Figure 13.19), the depth of penetration will be less than the value calculated by Eq. 15.4 when ave... 

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