Nitrate correlation

The spatial scale of intersite correlation differs somewhat with location. However, the average pattern for wet sulfate and nitrate correlation is shown with spacing of stations in Figure 4. The graphs represent an agglomeration of correlation data between 1981 and 1984 for more than 20 EUS sites. The distance over which correlation occurs for sulfate extends almost to 2000 km, but correlation decreases rapidly below less than 0.5 within 100 km. A similar pattern is found for nitrate, except the station spacing reflecting no correlation is less than for sulfate (approximately 1200 km). 

DRI), 1.66(AV), and 1.21(GGC). The high values for the AV and GGC collectors indicate that concentration effects due to evaporation are significant problems in these collectors. In the case of nitrate correlations, the slopes of the observed concentrations vs. the median values for the same sequence of collectors were found to be 0.83(SUNY), 0.94(CIT), 0.93(DRI), 2.43(AV), and 1.17(GGC). When identical RAC s were placed at different locations at Henninger Flats the results correlated quite well. There appeared to be no statistical difference between the separated collectors (66,67). 

To relate now the solution enthalpy to the slope of solubility curves, in Table 3.3 the AsHoo values are compiled for selected salts included in Figure 3.17. The steep increase of the solubility curve of potassium nitrate correlates with its comparatively high-positive solution enthalpy. Consistently, the weak (positive) temperature dependence of the sodium chloride solubility is expressed by a low (also positive) AsHoo value. Negative solution enthalpies occur for anhydrates of salts forming stable hydrates at room temperature (such as sodium sulfate and sodium carbonate) where hydration is connected vhth a strongly exothermal effect. 

Hji function. A better correlation, up to nearly 89% sulphuric acid, is obtained by comparing the results at 25 °C with the acidity function — (/f + log % q). si, 42a, 43a these comparisons a straight line of approximately unit slope is obtained (fig. 2.4), although for the nitration of benzene in acidities greater than 68% sulphuric acid, the slope becomes i-20 (fig. 2.5). 

The correlations of rates with acidity functions provide a convenient means of treatii results, and their uses will frequently be illustrated. However, their status is empirical, for whilst the acidity dependence of nitration becomes less steep with increasing temperature, the slope of... 

Reactivity numbers of the most reactive positions have been used to correlate the reactivities in nitration (see below) and other substitutions of a series of polycyclic aromatic hydrocarbons, and they give somewhat better correlations than any of the other commonly used indices of reactivity. The relationship shown below, which was discussed earlier ( 7.1.1),... 

Most correlations of rates with localisation energies have used values for the latter derived from the Hiickel approximation. More advanced methods of m.o. theory can, of course, be used, and fig. 7.1 illustrates plots correlating data for the nitration of polynuclear hydrocarbons in acetic anhydride -" with localisation energies derived from self-... 

With rates of nitration in sulphuric acid, Brown s (r+-constants do not correlate well. ... 

The development of linear free energy correlations of the rate of aromatic substitutions has been discussed ( 7.3). We record here the results of such correlations for nitration. 

For the nine substituents m- andp-methyl, p-fluoro, m- and p-chloro, m- and p-bromo, and m- and p-iodo, using the results for nitration carried out at 25 °C in nitromethane or acetic anhydride - (see tables 9.1, 9.5), a plot of logjoA/ j against cr+ produced a substituent constant p = —6-53 with a standard deviation from the regression line i = 0-335, 2 correlation coefficient c = 0-975. Inclusion of... 

Considering that the results used for these plots relate to nitrations carried out under different conditions, the success of the correlations is remarkable. 

No nitration of thiazole occurs with the classical nitration reagents, even in forcing conditions (341-343). In a study concerning the correlation between the ability of thiazole derivatives to be nitrated and the HNMR chemical shifts of their hydrogen atoms, Dou (239) suggested that only those thiazoles that present chemical shifts lower than 476 Hz can be nitrated. From the lowest field signal of thiazole appearing at 497 Hz one can infer that its nitration is quite unlikely. Thiazole sulfonation occurs... 

Inhibition of Nitrosamine Formation. Nitrites can react with secondary amines and A/-substituted amides under the acidic conditions of the stomach to form /V-nitrosamines and A/-nitrosamides. These compounds are collectively called N-nitroso compounds. There is strong circumstantial evidence that in vivo A/-nitroso compounds production contributes to the etiology of cancer of the stomach (135,136), esophagus (136,137), and nasopharynx (136,138). Ascorbic acid consumption is negatively correlated with the incidence of these cancers, due to ascorbic acid inhibition of in vivo A/-nitroso compound formation (139). The concentration of A/-nitroso compounds formed in the stomach depends on the nitrate and nitrite intake. 

Another interesting case occurred when attempting to correlate adipic acid plant product nitrate content with production rate. A plot of nitrate content versus production rate produced the worst shotgun effect I have ever seen. Each production level produced a range of nitrate contents. 

At best, expl power i a somewhat nebulous quantity. If we consider relative power as measured in a Ballistic Mortar or Trauzl Block, then OB correlates reasonably well with relative power, provided these comparisons are made for similar expls. This is illustrated in Fig 1, where Ballistic Mortar measurements axe respectively correlated with OB for nitro, nitramine, nitrate ester and aluminized expls. In general Ballistic Mortar measurements are more reproducible than Trauzl Block data. Consequently we have shown these in preference to Trauzl Block measurements. Correlation between Trauzl block data and OB are reported in Refs 1 8... 

Model A cannot be eliminated definitely by the photographs there are, however, some points which make this model improbable. From the curve for this model the first minimum would be expected to be at least as well pronounced as the second minimum, whereas on the photographs the first minimum is not very well defined. That the qualitative appearance of the photographs supports model C rather than model A is further shown by the fact that the photographs resemble those of methyl nitrate more closely than those of carbon tetrafluoride. Some evidence is also provided by the radial distribution curve (Fig. 1), the first peak being displaced by 0.15 A. from the position expected for it for model A. For these reasons and the additional reason that it is difficult to correlate the tetrahedral configuration with an electronic structure involving only completed octets, we consider model A not to be satisfactory.7... 

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