Nitrogen inorganic species

Char Analysis. Analyses of char samples were performed on specimens prepared at 2CPC/minute and held at temperature for 30 minutes. Below 55CPC carbonaceous char is present. Above 55CPC in air and above 60CPC in nitrogen the residue consists of zinc, zinc oxide, glass and other inorganic species as shown in Table III. 

The chemistry of inorganic nitrogen compounds is very complicated, and therefore, it is difficult to prove which of these compounds is of a real importance in biological systems. In addition to NO and peroxynitrite, the formation of N02, N203, and NO- might be of importance in biological systems. Some reactions of nitrogen oxide species are cited below. 

Also included in Table 7.7 are the nitrogen fixation reactions. These are similar to the carbon fixation reactions in that they involve the conversion of an oxidized inorganic species (N2) 1° a reduced form, such as ammonium. The fixed forms of nitrogen can be taken up by plants. As with carbon fixation, this process requires an energy source in order to proceed. Some N2 fixers are photosynthetic and others use energy obtained from the oxidation of reduced inorganic compounds. 

Nutrient regeneration The process whereby particulate organic nitrogen and phosphorous are transformed into dissolved inorganic species, such as nitrate and phosphate. Microorganisms are largely responsible for this process. 

Inorganic species Blow down extract with nitrogen to 50 pi... 

Crude oil is composed primarily of hydrocarbon compounds. Organic and inorganic sulfur-, oxygen-, and nitrogen-containing species are also found in crude oil. Additionally, water, vanadium, nickel, sodium, and other metals may be present. 

Generally, N03 dominates over NH4+ at sites close to emission sources (8,12). Dissolved organic nitrogen (DON) concentrations are highly variable in precipitation but often amount to 25-50% of inorganic N deposition (8, 12-14). In some areas, DON can occur in greater concentrations than the inorganic species (15). 

Relatively little quantitative kinetic data is available on the reactions of inorganic nitrogen compounds with other inorganic species. This arises because reactive nitrogen-containing species are relatively difficult to prepare and because many competing and concurrent reactions often occur in these systems making difficult the determination of elementary rate coefficients. 

Sulphur and nitrogen are removed as gases. Metals are deposited on the surface of the catalysts. This may be as a result of decreasing solubility of asphaltenes, as discussed above, or of chemical attack on the organic species associated with the heteroatom. The production of a molecule in which the inorganic species forms a larger fraction also leads to reduced solubility. Either associated with the chemical attack or subsequent to the initial attack, metals are converted to metal sulphides [17,18]. 

A number of inorganic species also absorb. We have noted that many ions of the transition metals are colored in solution and can thus be determined by spectrophotometric measurement. In addition, a number of other species show characteristic absorption peaks, including nitrite, nitrate, and chromate ions, the oxides of nitrogen, the elemental halogens, and ozone. 

Chemiluminescence methods are known for their high sensitivities. Typical detection limits range from parts per million to parts per billion or lower. Applications include the determination of gases, such as oxides of nitrogen, ozone, and sulfur compounds, determination of inorganic species such as hydrogen peroxide and some metal ions, immunoassay techniques, DNA probe assays, and polymerase chain reacrion methods.- ... 

The various redox reactions of inorganic nitrogen containing species are presented in Table 7-1. These reactions can be used to construct a pC-... 

In the polluted atmosphere, the principal reactions of HO with inorganic species are its termination reactions with nitrogen oxides to form nitrous and nitric acids ... 

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