Composites nitrogen-enriched

The second important parameter deals with the nature and composition of the oxynitride. Table 1 evidences that for one AIPO4 composition, the O/N ratio may be changed in two different ways, by acting either on the temperature or on the time of nitiidation. It has been previously reported (24) that the Al/P ratio may also influence this ratio, under the same nitridation conditions. Let us mention here that the bulk nitrogen enrichment of the solid is lower for higher Al/P ratios. The temperature of the nitridation reaction plays an important role and two main domains have been defined. 

The electrochemical performance of the nitrogen-enriched composites used as electrodes in supercapacitors is determined by the... 

Figure 9.10 Voltammetry characteristics at 10 mV/s scan rate for the Nt+M+F nitrogen enriched composite. Various aqueous electrolytic solutions and organic medium.

A second kind of model is briefly treated, based on isotopic mass balance arguments, and it is shown that large isotopic discrimination during methano-genesis in ruminants may account for data trends when comparing herbivores and carnivores. A third class of model is sketched at the level of biochemical flows, where some fundamental points are made concerning points where the isotopic composition of metabolites may be altered. The relevance of this to nitrogen isotopic enrichment is considered. 

Hydrogen in these particles is correlated with carbon and is presumed to occur in organic matter. Analyses of the isotopic composition of hydrogen (McKeegan et al., 2006) show D/H enrichments (Fig. 12.12). The D/H ratios overlap those of H20 in comets but are well below those determined for organic matter in CP IDPs. Measurements of nitrogen isotopes show 15N enhancements, suggesting an interstellar contribution. 

When a second nitrogen atom is introduced into the pyridine ring the basicity is reduced (pjRTa 5.23 for pyridine and 2.33 for pyridazine). The effect of the additional substituents on pKK depends on the position of the substituents (Table 3). An extensive set of pK values of pyridazine derivatives has been submitted to correlation analysis using the Hammett and the two Taft equations, which shows that the pKa values are most sensitive to the effect of a 2-substituent followed by the effects of 3- and 4-substituents. The interactions between nitrogen atom and 2-substituents represent over 70% of the inductive character. The composition of the effects of +M 4-substituents is significantly enriched in the resonance interactions, whereas -M 4-substituents interact with the nitrogen atom mainly by induction (77MI21201). 

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