Nitrate factors affecting levels

Candela, M. 1., Fisher, E. G., and Hewitt, E. J. (1957). Molybdenum as a plant nutrient. X. Some factors affecting the activity of nitrate reductase in cauliflower plants grown with different nitrogen sources and molybdenum levels in sand culture. Plant Physiol. 32 280-8. 

The behavior of chlorinated ethanes and ethenes in natural waters is variable and depends strongly on environmental conditions. For example, at some TCE-contaminated sites, a rapid decrease in concentration from high to negligible levels is observed, whereas at others the level of contamination remains constant (Chapman et al, 2007). Inadequate electron donors, high concentration of other electron acceptors like oxygen, nitrate, dissolved iron and sulfate, short contact time, absence of indigenous bacteria capable of dechlorination, and low pH in the subsurface are the most important factors affecting the natural attenuation of chlorinated solvents (Robinson et al 2009 Loffler and Edwards 2006). 

More details of other factors that affect the critical pitting potential have been discussed by Uhlig and his co-workers" . They indicated that for stainless steel the critical pitting potential decreased with increasing concentration of chloride ion. At a fixed chloride level, passivating ions in solution, such as sulphate and nitrate, etc., cause the pitting potential to become more positive at a sufficient concentration these ions totally inhibited pitting, as shown in Fig. 19.40 for SO and CIO . 

One way in which cobalt dispersion can be increased is the addition of an organic compound to the cobalt nitrate prior to calcination. Previous work in this area is summarized in Table 1.1. The data are complex, but there are a number of factors that affect the nature of the catalyst prepared. One of these is the cobalt loading. Preparation of catalysts containing low levels of cobalt tends to lead to high concentrations of cobalt-support compounds. For example, Mochizuki et al. [37] used x-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) to identify cobalt silicate-like species in their 5% Co/Si02 catalysts modified with nitrilotriacetic acid (NTA). The nature of the support also has... 

Section VI indicates that availability of nitrate at the induction and assimilation sites plays a major role in regulating the level of nitrate reductase and the in situ rate of reduction of nitrate. If this is valid, then factors that regulate the uptake, translocation, and entry of nitrate into the cytoplasm of cells of various plant organs have more significant effects on regulating enzyme induction and rate of nitrate assimilation throughout the life cycle of plants than other mechanisms that affect induction, inhibition, and assimilation. 

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