Nitration ratio

The constancy of the acetoxylation nitration ratio and zeroth reaction order in aromatic suggested that both reactions were brought about by a common species (protonated acetyl nitrate) the formation of which was rate-determining according to equilibria (30) and (31), with the latter being a slow step. Since the total rate of acetoxylation plus nitration is given by... 

Fig. 17 Reciprocal perturbations in nitrations ratios of 4-/2-nitration are shown in parentheses...

P. Imas, B. Bar-Yosef, U. Kakafi, and R. Ganmore-Neumann, Carboxylic anions and proton secretion by tomato roots in response to ammonium/nitrate ratio and pH in nutrient. solution. Plant Soil 191 (1997). 

From these two reduction processes, it follows that the transformation of 1/5 mole of NO3-N equals the transformation of 1/4 mole of 02, i.e., the oxy-gen-to-nitrate ratio for comparison of the two substances as electron acceptors is as follows ... 

Reduction of nitrate (and nitrite) occurs by interaction with the metal, for example, by metallic iron that has been widely studied for elaborating a technology to remove nitrate from water [66-70]. The very principle of this procedure that the anodic transformation (dissolution) corrosion of metallic iron Fe(0) leading to the formation of Fe(II) and Fe(III) species is coupled with the reduction process. The effect of pFi and the iron-to-nitrate ratio, temperature, and mass transport were studied under various conditions in order to elaborate a suitable technology. 

Data have been presented on the kinetics of nitration of acetanilide in mixtures of nitric and sulfuric acids.29 A review discusses the several mechanisms operative in the nitration of phenol including /> / -sclective nitrosation-oxidation and mechanisms involving phenoxy radical-nitrogen dioxide reaction yielding a 55 45 ortho para nitration ratio.30 The kinetics of mononitration of biphenyl-2-carboxylic acid have been investigated in several solvents. The maximum ortho para product ratio of 8.4 is observed in tetrachloromethane.31 Nitration products were not formed in the presence of dioxane.31,32 Quantum-chemical AMI calculations were performed and the predominant formation of the ortho-nitro product is accounted for by stabilization of the cr-complex by the carboxyl group.33... 

The influence of nitrogen concentration and ammonium/nitrate ratio on N-uptake of citrus was studied by Serna et al. (1992). In short-term water culture experiments with 15N labelled NH/ or N03 at various concentrations, citrus seedlings absorbed... 

Summers, P.W. Barrie, L.A., "The Spatial and Temporal Variation of Sulphate to Nitrate Ratio in Precipitation in eastern North America," presented at Muskoka Conference, September, 1985. 

Note This procedure is not applicable to liquids or to materials having a high chlorine-to-nitrate ratio. 

Turner, R. E., Qureshi, N., Rabalais, N. N., Dortch, Q., Justic, D., Shaw, R. F., and Cope, J. (1998). Fluctuating silicate Nitrate ratios and coastal plankton food webs. Proc. Natl Acad. Sci. U.S.A. 95, 13048-13051. 

Conditions which favor peroxynitrite formation could result in dramatic shifts in the nitrite/nitrate ratio as well as significant loss of total nitrogen oxides through tyrosine nitration. 

The importance of the base to alkyl nitrate ratio on the mononitration of cyclanones in the KNH2-A.NH3 system is shown in Table VIII. A 2 1 ratio of nitrating agent to base is essential to obtain high yields. 

JACOBSON I think the clearest way of describing the data in Table III is that the applications of simulated rain with the higher sulfate to nitrate ratios increased the dry mass of apical leaves and roots of lettuce plants. Unfortunately, we have no information on the sulfur content of the soil. Perhaps addition of sulfate in rain can overcome sulfur deficiency in the soil. Future experiments on the effects of acid rain should always include measurement of soil sulfur. 

JACOBSON The interpretation that the high sulfate to nitrate ratio increased growth is indeed more reasonable than suggesting that the high nitrate to sulfate ratio treatment depressed growth. 

Figure 39.4 shows the effect of urea addition on the morphology and nanoparticle formation of YAH (hexagonal YAIO3, an intermediate phase of YAG). The urea-nitrate ratio, in which the nitrate represents the precursor solution, was varied from 0 to 30. Figure 39.4a shows that most of the particles prepared from a precursor without a urea addition were in the submicron size (400-700 pm) with a small amount of nano-sized particles. When 1 M of urea (urea-nitrate ration is 10) was added, the quantity of nanoparticles increased while the size of larger particles was reduced. Well-dispersed nanoparticles, with an average size of 20 nm, were produced from the addition of 2 M urea in the nitrate precursor, as shown in Fig. 39.4c. The addition of more than 2 M of urea produced nanoparticles with an agglomerated morphology, as shown in Fig. 39.4d (urea addition of 3 M). These results show that the addition of 2 M urea into 0.1 M nitrate precursor is an effective way to produce...

Fig. 39.4 FE-SEM images of hexagonal YAIO3 (YAH, intermediate phase of YAG) indicating nanoparticle dispersion evolution as a function of urea-nitrate ratios of (a) 0, (b) 10, (c) 20, and (d) 30. ([9] Reproduced by permission of Elsevier)...

Determination of nitrite/nitrate ratio in meat products nitrate in the water being used... 

Online monitoring and control of the biological denitrification process in a cell recyle membrane reactor has been developed and implemented at laboratory scale. The system has been tested with a real groundwater contaminated with nitrate. It is shown that a simple feedforward control strategy that adjusts the feed rate of the carbon source to maintain the optimum inlet carbon/nitrate ratio value is effective at reducing both nitrate and nitrite concentrations in the treated water below the maximum admissible values. 

Using an identical analytical setup for the determinations of nitrite and nitrate (identical cuvette lengths and reagents), the calibration factor (see Section 10.2.4) for nitrate should be 0.48 times that of nitrite. A 50 % reduction of the absorbance/nitrate ratio is caused by the 1 + 1 sample/buffer dilution in the nitrate determination. The addition of 2mL of reagents (2 1 mL) to a 25 mL nitrate sample as opposed to 2mL of reagents to a 50 mL nitrite sample causes another 2 % loss in the absorbance/nitrate ratio. 

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