Volume 466, Nº 2 (2016)

Mechanisms of consumption of inhibitors in gas mixtures in different combustion modes—ignition prevention and suppression of flame propagation and detonation—have been revealed. It has been found that no more than a few hundredths of a percent of the initial reagents, including the inhibitor, are consumed for the prevention of ignition. In suppression of flame propagation and detonation, the inhibitor is consumed only in chain termination reactions. Oxygen is additionally consumed only in reactions with the products of incomplete oxidation of the inhibitor. The results have been interpreted in the framework of the theory of nonisothermal chain processes.

The products of bromination of polychlorinated biphenyls (PCBs) that constitute Trichlorobiphenyl and Sovol PCB technical mixtures were studied by gas chromatography–mass spectrometry. On the basis of mass spectrometric data, the reaction was shown to result in formation of a mixture of poly(bromochloro)biphenyls containing from one to five bromine atoms and from two to six chlorine atoms in different combinations. It was found that the content of monobromo derivatives increases while the content of di-, tri-, and tetrabromo PCB derivatives decreases when the chlorination degree of the initial PCBs increases.

Deuterium-labeled 5-oxo-Pro-Arg-Pro, 5-oxo-Pro-His-Pro-Gly-Pro-NH₂, and Phe-Pro-LeuPro-Ala were synthesized. The effect of the method of peptide deposition on the catalyst, the catalyst nature, temperature, and structure of peptides on the inclusion of deuterium with the formation of the appropriate number of isotopomers was demonstrated. The 5-oxo-Pro-Arg-Pro, 5-oxo-Pro-His-Pro-Gly-Pro-NH₂, and Phe-Pro-Leu-Pro-Ala peptides containing, on average, 4.6, 7.7, and 5.4 deuterium atoms per peptide molecule, respectively, were obtained.

The first results of studying the possibility of self-preservation of methane hydrates produced in a “dry-water” dispersion were presented. It was shown for the first time that the anomalously low rates of dissociation of gas hydrates at a temperature below 273 K and a pressure of 0.1 MPa, which were previously known for methane hydrates, are also characteristic of methane hydrates forming in dry water. Methane hydrates obtained in dry water containing no more than 5 wt % stabilizer (hydrophobized silica nanoparticles) are primarily solids at a pressure of 0.1 MPa and a temperature below 273 K. At a stabilizer content of dry water of 10 or 15 wt %, a significant part of the hydrate sample looks like a free-flowing powder. The powder fraction increases with increasing stabilizer content, which reduces the efficiency of self-preservation of methane hydrates.