Decomposition, stages fresh

Vibrational Spectra. Infrared spectra were obtained by pressing the freshly prepared powders between silver chloride plates. In the case of CfiF AsF, products of thermal decomposition were present in each spectrum. By recording spectra at successive stages of decomposition, however, it was possible to distinguish those features due to the radical cation salt. In additicm to the characteristic absorptions due to Asp , ... 

Detrital processing can be thought of as a continuum from fresh litter to stabilized SOM (Agren and Bosatta, 2002). At different stages in this continuum, the relative importance of each of these environmental and biological factors that have been identified as controlhng decomposition dynamics will likely vary. The initial stages of mass loss are characteristically most affected by climate, resource quality, and, when abundant, soil macrofauna. The physical soil environment also needs to be considered as an important control on the turnover of more humified SOM in the mineral horizons. It is also evident from this literature review that observed correlations between decay rates and decomposition factors are often attributable to both the direct effects of that factor on microbial metabolism and to the indirect interactions with other factors. 

The above-considered calculational data point to high effectiveness of the bifunctional catalysis in hydrolytic reactions and the reactions related to these, due to involvement of molecular chains of water and ammonia, as well as to the preferability in these reactions of a concerted mechanism. This conclusion is fairly general and is corroborated by calculations on other types of nucleophilic reactions, such as hydrolysis of methyl fluoride, tautomerization of pyridine in aqueous solution etc. [110]. An advisable piece of work would apparently, be an analysis, in the light of the conclusions discussed, of mechanisms of the catalytic act in enzymic hydrolysis reactions of the ester and peptide bonds. In the most advanced up-to-date models for, e.g., the reactions with participation of a-chymotrypsin (see Ref. [Ill]), the steps of the base and the acid catalysis are separated. The latter is commonly thought [84, 111] to be operative at the stage of enzymic decomposition of the tetrahedral intermediate. However, taking into account the possibility of realization of the conformationally excited states of the active enzymic center, it would not be hard to think of some realistic schemes of concerted mechanisms, the more so that the fast growing body of calculational material continuously supplies fresh evidence in favor of such mechanisms. 

The elevated temperatures used during deodorization are sufficient to initiate some chemical reactions both on the oil and on some of its minor components. Hydroperoxides, frequently the precursors of off-flavor development, are completely broken down during the deodorization process, so the peroxide value of a freshly deodorized oil is zero. Values other than zero frequently indicate the presence of a small air leak in the equipment, normally in the post-deodorization cooling stages. Volatile products of this thermal decomposition are normally stripped from the oil during the deodorization process, but any nonvolatile fragments will stay with the finished oil, possibly with detrimental effects on its quality. 

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