Nitrogen, correlation between sulfur

EVANS Why do you think the correlation between sulfur oxides and nitrogen oxides and protons is only 0.82 What do you think are the major components that would not solidify the nitrogen ... 

Correlation between sulfur laboratory data and LIBS intensity in natural coals in VUV in air with nitrogen flashed spectrometer using single-pulse IR excitation (a). Two different trends represent two coal types and result from matrix effect (b)... 

Burning fossil fuels can release air pollutants such as carbon dioxide, sulfur oxides, nitrogen oxides, ozone, and particulate matter. Sulfur and nitrogen oxides contribute to acid rain ozone is a component of urban smog, and particulate matter affects respiratory health. In fact, several studies have documented a disturbing correlation between suspended particulate levels and human mortality. It is estimated that air pollution may help cause 500,000 premature deaths and millions of new respiratory illnesses each year. 

The nitrogen cycle is closely connected with the fluxes of hydrogen, sulfur, and other chemicals (Smith et al., 1998 Dimitroulopoulou and Marsh, 1997 Chapin et al., 2002 Rhee et al., 2005 Stevenson and Cole, 1999). Nitrogen and hydrogen react under great pressure and temperature in the presence of a catalyst to make ammonia. The study of correlations between the cycles of these elements is necessary to improve... 

Investigation of replacement of the 5-methoxy group by substituents with different electronic and lipophilic properties and methylation of the indole nitrogen or its replacement by a sulfur atom was evidence for the shift of the 5-methoxy group to the 4-position of the indole nucleus led to the most active radical scavenger but much less effective as a cytoprotectant [135]. 5-alkoxy-2-(N-acylaminoethyl)indole (Fig. 15) appeared as the key feature to confer both antioxidant and cytoprotective activity to the structure. Antioxidant activity seems essential for cytoprotection, but it is not sufficient, and there is no statistically significant correlation between the two types of activity. 

Figure 15.7. Stoichiometric correlations among nitrate, phosphate, oxygen, sulfide, and carbon. The correlations can be explained by the stoichiometry of reactions such as equation 3 concentrations are in micromolar, (a) Correlation between nitrate nitrogen and phosphate phosphoms corrected for salt error in waters of the western Atlantic, (b) Correlation between nitrate nitrogen and apparent oxygen utilization in same samples. The points falling off the line are for data from samples above 1000 m (Redfield, 1934, p. 177). (c) Correlation between nitrate nitrogen and carbonate carbon in waters of the western Atlantic, (d) Relation of sulfide sulfur and total carbonate carbon in waters of the Black Sea. Numbers indicate depth of samples. Slope of line corresponds to AS /AC = 0.36. (From data of Skopintsev et al., 1958, as quoted in Redfield et al., 1966.) (e) Correlation of the concentration of nitrogen to phosphate in the Atlantic Ocean (GEOSECS data). The slope through all the data yields an N/P ratio close to 16.

In a study of the relative ligand coupling efficiencies between oxygen, sulfur and nitrogen containing heteroaromatic systems, the correlation between the ligand coupling abilities and the C-NMR values of the ipso carbon atoms (6 in ppm are reported in Scheme 3.15) was not clearly... 

Photoelectron spectroscopy has demonstrated that there is no linear correlation between the ionization energies and p values of azoles <84JHC269>. The gas phase photoelectron spectra of a series of hydantoin derivatives (32) have been compared with those of model compounds, and with the results of HAM/3 and CNDO/S calculations. Evidence is found for significant interactions between the 7r-orbitals and the chalcogen atoms for sulfur and selenium derivatives. In contrast, n-orbitals of the nitrogen atoms are localized in the whole series of compoimds, especially in the oxy analogues and in monosubstituted derivatives <88JST(175)447>. 

Analyses of feed composition and of spent catalysts from the catalyst performance tests show that there is a fairly good correlation between the amount of coke and the amount of PNA in the feeds as seen in figure 1. The amounts of mono, di- or triaromatic compounds in the feed do not significantly influence the amount of coke. Since the sulfur compounds are almost exclusively found in the diaromatic fractions which often constitute the major part, the feed sulfur seems to be unimportant for coke formation. These results show that the most important coke precursors must be present in the PNA fraction, which as mentioned also contains all the nitrogen compounds. 

Correlations between the parameters Bj and aj and AE and rj within each term can affect the accuracy of the best-fit results. An even worse problem for the present system is that the phase and amplitude functions for the two types of neighbors (nitrogen and sulfur or chlorine) are not sufficiently different to prevent "trade offs between the two terms. Both of these problems can be circumvented by the FABM method. 

A subset of emissions is visual opacity from the stack. A direct correlation between opacity, particle loading and size can be computed using simple light scattering computations where sulfur is not a significant contributor. Nitrogen oxides ... 

Acid precipitation shows a strong geographic dependence, as illustrated in Figure 15.10, representing the pH of precipitation in the continental U.S. The preponderance of acidic rainfall in the northeastern U.S., which also affects southeastern Canada, is obvious. Analyses of the movements of air masses have shown a correlation between acid precipitation and prior movement of an air mass over major sources of anthropogenic sulfur and nitrogen oxides emissions. This is particularly obvious in southern Scandinavia, which receives a heavy burden of air pollution from densely populated, heavily industrialized areas in Europe. 

Exponential correlations (E). These correlations have the general form of Equations 12.5 and 12.6. Ng (1997) established various exponential correlations to predict variations of total sulfur, metals (Ni + V), CCR, and nitrogen contents in deasphalted oils (DAO) as a function of the asphalt content (defined by the author as the sum of resins and asphaltenes). The correlation for sulfur (Equation 12.21) shows a moderate value (0.6328), while the Equations 12.22 through 12.24 for metals, CCR, and nitrogen have between 0.8819 and 0.9389. 

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