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Data on the reserves of viable micro-organisms in the snow cover, thawing waters and soils after snow melting are presented, and indicators of sanitary indicator bacteria Clostridium perfringens, and Escherichia coli group are demonstrated. The participation of alien microorganisms in the increase of toxigenicity of urban soils is shown.

The bio-mass of soil microorganisms and other biological characteristics of soils (respiratory and phosphatase activity) and the microbial component of soils (metabolic coefficient of the biomass and the k_C factor) were studied in the soils of southern and northern subzones of subarctic tundra of Middle Siberia (the Taimyr peninsula). It has been found that the soil microorganisms biomass content, the respiratory activity of the soil and its phosphatase activity strongly vary within the limits of the zone under study, which reflects the special chaoticity of microecotopes of the tundra zone. Thus, the biomass content varied from 1 mg C/100 g (in the soil directly adjoining the permafrost layer in the lower part of the cryoturbation spot in the south of the zone) to 140 mg C/g (in the peated humic gley horizon under grass-moss tundra in the south of the zone). The obtained values of the microbial metabolic coefficient for tundra soils (0.1 to 5 mcg C-CO₂ ^. mg-1 biomass C/hr) are within the limits of values established for soils of other bioclimatic zones. A study of behavior of the microbial component of tundra soils under laboratory conditions has demonstrated that as the temperature increases, the phosphorus immobilization by the microbial biomass bacomes more intense.

For CH₄/O₂ flames doped with trimethyl phosphate (TMP), the flame structure is examined and the velocity of flame propagation is determined with the aim of studying the mechanism of inhibition of flames doped with organophosphorus compounds. The structure of a methane–oxygen flame doped with TMP stabilized on a flat burner at a pressure of 1 atm was studied. The dependence of flame propagation velocity on the concentration of TMP is measured using a Mache–Hebra burner to determine the effectiveness of a number of TMP as a flame inhibitor. The mechanism of destruction of TMP in flames was used to model the flame structure and calculate the velocities of propagation of a methane–air flame as functions of the initial concentration of TMP. Calculation and experimental results are compared.

The paper considers a mathematical model, an algorithm, and a program for calculating nonstationary processes of air gasification of a high-ash coal under pressure in a pilot-scale circulating fluidized bed gasifier reactor. The effect of operation parameters on the course of the process is analyzed. It is shown that "hot spots" (short-duration local heatings) can form at various points of the bed, at which maximum temperature can be close or even exceed the fluid slagging point. Possible mechanisms of formation of "hot spots" are analyzed.

A mathematical model is constructed for compaction of a reacting heterogeneous mixture under continuous loading. A two-component mixture containing a low-melting component is considered. Compaction of the stoichiometric mixtures is analyzed in detail. Formulas for the dynamics of structural transformations and macroscopic characteristics of the product are obtained. It is established that there are different regimes of the process, depending on synthesis conditions, physicochemical parameters of the mixture, and the load.

The paper studies the combustion of mixtures of commercial aluminum powders (ASD-1 and ASD-4) and ultrafine powders of Al and γ-Al₂O₃ in air. It is shown that the combustion of coarsely dispersed commercial powders is accompanied by binding of air nitrogen with formation of AlN and AlON. The combustion of mixtures proceeds in two stages with the possible formation of intermediate gaseous and liquid products. The processes of sintering and incomplete combustion play an important role in the combustion of mixtures of commercial powders and ultrafine powders of aluminum.

The influence of radiation on the characteristics of high-temperature and hysteresis oxidation regimes for a metal particle with an oxide film in a condensed state on its surface is studied. Conditions are defined under which radiative heat exchange with cold walls of the reactor decreases the burning temperature, critical temperatures, and oxide-film thickness, i.e., parameters characteristic of ignition and forced and spontaneous extinction of a metal particle.

The paper reports experimental methods for studying soot formation upon thermal decomposition of carbon and fiberglass plastics in flows of high-temperature gas and flame. The mechanism of the process is analyzed and its microkinetic parameters are determined. The problem of unsteady heating of a semi-infinite body of semitransparent fiberglass plastic is formulated and solved numerically taking into account the process of soot formation under conditions of radiant-convective heat transfer. A comparison of calculation results with experimental data is given in dimensionless variables.

A method for recording values of the electromotive force (e.m.f.) in a combustion wave in conducting condensed systems is proposed. The method uses electrodes made of the solid combustion products of the condensed system studied. The e.m.f. in the combustion wave in the 3Zr + 2WO₃ and Ti + C + 20% TiC systems were measured to be 70–80 and 24–27 mV, respectively (the e.m.f. for these systems has different polarity). It is shown that in the combustion wave of the Al + Ni system, the e.m.f. is close to zero (does not exceed 1–2 mV).