29) ratio values reflect the higher contents of carboxylic acids, carbohydrates and aliphatic character of humic acid or lower degree of condensation and aromaticity
As the light absorption molecules of dissolved humus reach higher levels of aromaticity
, the absorption spectra tend to shift towards longer wavelengths.
Overall, the results reflect the strong aromaticity
of the biochars produced in this experiment (both treated and controls).
The increase in resistance to radiation with excess of HMMM can be ascribed to the increase in aromaticity
due to the presence of more triazine rings.
Overall, the different spectra obtained for each type of char confirmed the results inferred from the elemental analysis of the samples, that is, the greater aromaticity
of the biochar sample (produced at 550[degrees]C) than the hydrochar sample, and the greater potential reactivity of the hydrochar relative to the biochar (if the inorganic fraction is excluded).
Once segregation has taken place in our system, there may be also an enthalpy gain for ester exchange reactions running in the direction of a progressive increase of the degree of aromaticity
of the LC phase.
The extent of sorption of pesticides in soils has been found to depend on the aromaticity
of SOC (Ahmad et al.
The degree of aromaticity
of the different materials, calculated as the ratio of the number of aromatic carbons to the total number of atoms in the backbone, according to Calundann and Jaffe (39) is also reported in Table 4.
Aromatic characteristics, obtained from the aryl and O-aryl groups, also showed the lowest proportions in the CR plot and the highest aromaticity
in the 2 BF plots.
Under comparable conditions, practically no evidence of such reactions was found with the LCP of highest aromaticity
About 73% of aromaticity
could be explained by the variation of temperature/precipitation ratio and the rest by the variation of soil pH and the C:N ratio.
irradiation induced also chemical structural changes through chain scission, crosslinking and recombination by the free radicals and physical structural changes through amorphization, loss of aromaticity
, and decrease of molecular stereo-regularity (28, 29).