Home – Home – Jornals – Atmospheric and Oceanic Optics 2023 number 11

Simple isotopic relations relating the energy levels of the isotopologues ³²S¹⁶O₂, ³³S¹⁶O₂, and ³⁴S¹⁶O₂ with the levels of other isotopic variants are applied to calculations of vibrational-rotational energy leveles. To estimate the accuracy of the isotopic ratio, we calculated and compared with the measured line centers of the microwave spectrum of the ³⁶S¹⁶O₂ isotopologue. Comparison showed their quite satisfactory agreement at a level of 10^-3 cm^-1. Vibrational-rotational energy levels of sulfur dioxide isotopologues X S¹⁶O₂, X = 35-38, up to J = 9 for five lower vibrational states are presented.

The chemical composition of aerosol in the atmosphere of the research station „Cape Baranov Ice Base“ (Severnaya Zemlya archipelago) collected in 2017-2022 is studied. The interannual and seasonal dynamics of ions and trace elements in the aerosol composition is analyzed in detail. A 1.5-fold increase in the annual mean concentrations of the sum of ions is traced. The growth of the sum of ions was mainly due to the concentrations of ions of marine origin Na⁺ and Cl^-, the content of which is minimal in summer and maximal in winter. The variability of concentrations of non-marine ions NH₄⁺, K⁺, Ca²⁺, F^-, NO₂^- i NO₃^-differed from the seasonal course of concentrations of Na⁺ and Cl^- and consisted in a decrease during the transition from winter to spring season and an increase in the summer period with a subsequent decrease in autumn against the background of an increase in the sum of ions at the expense of ions of marine origin. Formation of aerosol ion composition is affected by the marine factor, air mass transport, underlying surface, and wildfires. Among trace elements, Fe, Al, Zn, Mn, Sn, Cr, and Cu dominated with high concentrations in the fall and winter periods. Based on enrichment factors, elements of terrigenous (Al, Ti, Mn, Fe, Th, U), mixed terrigenous and non-terrigenous (Li, Be, V, Co, Sr, Ba), and non-terrigenous origin (Ni, Cu, Zn, Cr, Mo, Mo, W, Ag, Tl, Pb, As, Se, Cd, Sn, Sb) are identified. In winter and autumn periods, Fe and Mn have the highest contribution to the total level of air pollution, while in spring and summer, Fe and Be. Among non-terrigenic elements, Cu, Sn, Zn, Se and Ni had increased contribution in all seasons. The level of atmospheric pollution by trace elements at the station „Cape Baranov Ice Base“ is assessed as low.

Measurements of polarization scattering phase functions and spectral extinction coefficients were carried out in smoke aerosols formed as a result of thermal decomposition of pine wood in the mode of low-temperature pyrolysis in the Big Aerosol Chamber (BAC) of IAO SB RAS. Using the developed algorithm for inverting optical measurements, the microstructure and complex refractive index of pyrolysis smoke are retrieved. The volume concentration and the mean radius of particles are analyzed microstructure parameters, with division into fine and coarse fractions. The temporal variability of the microphysical parameters of smoke aerosol is studied for 65 hours. It has been established that the real part of the refractive index is in the vicinity of n = 1.55, and the imaginary part is in the range 0.007 < k < 0.009. The mean radius of fine particles varies in the narrow range 0.137-0.146 mm. During smoke aging, the mean particle radius of the total ensemble monotonically increased from 0.19 to 0.6 mm, mainly due to a relative increase in the content of coarse aerosol. Results of this work are important for estimation of the radiative forcing of aerosol, improvement of climate models and algorithms of remote optical sounding.

Based on the results of a comprehensive experiment conducted in September 2020, the spatial distribution of the following trace gases over the seas of the Russian Arctic are analyzed: carbon monoxide (CO), ozone (O₃), nitrogen oxide and dioxide (NO and NO₂), and sulfur dioxide (SO₂). It is shown that the gas concentrations in the surface air layer over the seas (at a height of 200 m) vary in the range 18-36 ppb for O₃, 60-130 ppb for CO, 0.005-0.12 ppb for NO, 0.10-1.00 ppb for NO₂, and 0.06-0.80 ppb for SO₂. Over most seas, the distribution of the gases across the water area is heterogeneous, which most likely reflects differences in their uptake by the ocean and peculiarities of transport from the continent.

Behavior of ozone in the Arctic is of major concern. Ozone anomalies occur every five years on the average. The last, record strong decrease of the ozone level in the stratosphere of the Arctic took place in March-April 2020. In February 2022, ozone destruction developed by the scenario very similar to the anomaly of 2020. Like in 2020, the ClO mixing ratio, which can be considered a reliable indicator of ozone destruction, strongly increased after the end of the polar night in Arctic latitudes in 2022, but the subsequent ozone depletion process was halted by a sudden major stratospheric warming on March 20, 2022. In this work, we analyze ozone destruction in 2020-2022 based on measurements of the total ozone content over 2003-2022 from the TEMIS service, profiles of the air temperature and ozone mixing ratio for 2005-2022 and of ClO mixing ratio for 2020-2022 from Aura MLS observations. The following sites are considered: Eureka, Canada; Ny-Ålesund, Norway; Thule, Greenland; and Resolute, Canada. A relationship is revealed between ozone and chlorine oxide contents. High coefficients of correlations between oscillations of the above parameters at close altitudes of their recording, as well as between the total O₃ and ClO contents calculated from their profiles, indicates their close interrelation. Hence, the ClO concentration and total content can be used as indicators of ozone destruction in the Arctic stratosphere.

Atmospheric waves are of increased interest in connection with exchange processes occurring in the atmospheric boundary layer. Experimental results of sounding mesoscale Kelvin-Helmholtz waves by turbulent lidars in a stably stratified boundary layer of the atmosphere are presented. This paper presents the data of measurements by BSE-4 lidar (532 nm), which has been working over forest-steppe for a long time. Atmospheric waves in most cases were observed in the evening and at night in the range of heights from the land to 600 m, when the Richardson number in the surface air layer did not exceed a critical value of +1/4. Fourier analysis of the time series of the structural characteristic of the refractive index Cn² showed that the spectrum of the wave process in the atmospheric boundary layer consists of a set of monochromatic waves with different oscillation frequencies. During the observations, the period of the waves varied from 1 to 11 min, and their amplitude changed from 20 to 300 m. It is found that monochromatic waves exist from half an hour to two hours. The disappearance of some monochromatic waves is compensated by the appearance of new ones. The process of generating small-scale turbulence runs throughout the life cycle of a Kelvin-Helmholtz wave. The results indicate that the turbulent lidar ensures remote detection and observation of atmospheric waves.

The article studies a single thundercloud that developed at night near the coast of the Gulf of Finland. Using three meteorological radars, two lightning detection systems, and a 3D numerical model, the physical processes that caused its electrification are analyzed. It is shown that the first lightning occurred during the period when there was a small area containing graupel particles in the upper part of the cloud. Updrafts played an important role in the formation of this area and the microstructure of the cloud, as shown both by radar observations and numerical simulation. Further intensification of thunderstorm activity is associated with an increase in the cloud volume with graupel and hail. Analysis of the charge values of individual cloud fractions based on the results of numerical simulation showed that hailstones are the main carriers of the negative charge.

The paper is devoted to the study of the effect of relative air humidity on the color of diffuse plasma jets (DPJs) initiated by a capacitive discharge at pressures of 0.03-1 torr, which are analogues of columnar sprites. Photographs and emission spectra of DPJs are given, as well as a photograph of a sprite. The results of the study showed that a decrease in the relative air humidity at pressures less than 0.1 torr contributes to the preservation of the red color of DPJs. Quantifying the average number of red and blue pixels in the photographs confirms this result. It has been established that an increase in the reduced electric field leads to a change in the color and spectrum of the periodic domain structure due to an increase in the intensity of the emission of the bands of the first negative nitrogen system.

In order to study temporal variations in the mixing ratios of greenhouse carbon-containing gases and factors influencing them, local measurements of CO₂, CH₄ (January 2013 - January 2020), and CO (January 2013 - January 2019) mixing ratios in atmospheric air at the St. Petersburg State University station are analyzed. For this analysis, the trend and seasonal oscillations are taken into account. Linear trends for CO₂, CH₄, and CO, which are 2.42 ppm/year (0.60%), 8.6 ppb/year (0.49%), and -3.8 ppb/year (-2.2%), respectively, are in a good agreement with independent estimates for both global/background changes and changes in urban area. The analysis of the CO/CO₂ emission ratio confirmed that motor vehicles are the dominant anthropogenic source affecting the composition of atmospheric air in the area of the St. Petersburg State University monitoring station. The results presented in this work can be used for validation of atmospheric models, as well as for independent estimations of greenhouse gas fluxes.

A new iterative method for the modeling of non-Gaussian random vectors with given marginal distributions and covariance matrix is proposed in this paper. The algorithm is compared with another iterative algorithm for the modeling of non-Gaussian vectors, which is based on reordering a sample of independent random variables with given marginal distributions. Our numerical studies show that both algorithms are equivalent in terms of the accuracy of reproducing the given covariance matrix, but the proposed algorithm turns out to be more efficient in terms of memory usage and, in many cases, is faster than the other one.

In this paper, iterative stochastic simulation algorithms for the Lamè equation describing the displacements of an isotropic elastic body are constructed. Three different stochastic methods are proposed: the first one is based on a global algorithm of random walk on spheres to compute the solution and its derivatives for an anisotropic diffusion equation. It does not use grids and does not require large amounts of RAM. The second method is based on a randomized algorithm for solving large systems of linear equations and requires the introduction of a grid. The third method is also grid-based and uses a random walk algorithm. All three methods implement an iterative process, at each step of which anisotropic diffusion equations are solved. The paper provides a comparative analysis of the proposed methods and discusses the limits of applicability of each of them.

A review of the relatively little-known matrix class, called coninvolutions, is given. The properties of these matrices are compared with those of the well studied involutory matrices or, briefly, involutions.

The Lax-Friedrichs scheme is traditionally considered an alternative to the Godunov scheme, since it does not require solving the Riemann problem. In the equations of special relativistic hydrodynamics, the speed of light is a natural limitation of the wave propagation speed. The use of such an upper estimate of the slopes of characteristics in the schemes of Roe, the Rusanov type, or the Harten-Lax-Van Leer family leads to a construction equivalent to the Lax-Friedrichs scheme. Due to the absolute robustness of the scheme, a number of software implementations have been developed on its basis for modeling relativistic gas flows. In this paper, we propose a piecewise parabolic reconstruction of the physical variables to reduce dissipation of the numerical method. The use of such a reconstruction in the Lax-Friedrichs scheme allows us to obtain an absolutely robust simple scheme of high-order accuracy on smooth solutions and with small dissipation at the discontinuities. The computational experiments carried out in the article confirm these properties of the scheme.

A new correlative-grid approximation of a homogeneous and isotropic random density field is introduced for the effective numerically-analytical investigation of overexponential growth of the mean particles flux in a random medium with multiplication. In this case the complexity of the particle trajectory realization is not dependent on the correlation scale. For the correlative-grid approximation the possibility of a Gaussian asymptotics of the mean particles multiplication rate is justified for a random field of bounded density. It ensures a superexponential growth of the flux in some initial time interval. An estimate of further overexponential flux growth is constructed based on some test computations.

A process of searching on the sphere for the best (in a sense) cubature formulas that are invariant under the transformations of the icosahedral rotation group is described. The parameters of the best cubature formulas of this symmetry type up to the 30th order of accuracy are given to 16 significant digits. A table which contains the main characteristics of all the best to date cubature formulas of the icosahedral rotation group up to the 79th order of accuracy is given.

To calculate flows of a gas-liquid mixture, a modified inverse method of characteristics is proposed, in whose algorithm an additional fractional time step is introduced, which makes it possible to carry out calculations with a large time step without loss of accuracy and stability. A formulation of boundary conditions on curvilinear walls is discussed in relation to the multidimensional nodal method of characteristics, which is based on splitting along the coordinate directions of the original system of equations into a number of one-dimensional subsystems. For the boundary points located on curvilinear impenetrable surfaces, a calculation method based on the method of fictitious nodes is proposed. When testing the modified method, the supersonic interaction of a homogeneous dispersed flow with a barrier is calculated for a flow regime with an attached shock wave. Problems of steady mixture flows near an external obtuse angle, as well as near a cone, which are analogues of the Prandtl-Meyer and Busemann flows in gas dynamics, are solved. The calculation results are compared with available self-similar solutions, and a satisfactory agreement is reached.

A difference scheme of the predictor-corrector type is constructed for solving nonlinear dispersion equations of wave hydrodynamics with a high order of approximation of the dispersion relation, based on splitting of the original system of equations into a hyperbolic system and a scalar equation of the elliptic type. A dissipation and dispersion analysis of the new scheme is performed, a condition for its stability is obtained, and a formula for the phase error is written and analyzed. Parameters are found at which the phase characteristics of the difference scheme, the nonlinear-dispersive model approximated by it, and the full model of potential flows have the same order of accuracy.

Results of studying stabilization of a homogeneous hydrogen-air flame on an optical discharge plasma in a high-velocity flow are reported. The main aspect of experiments is providing stable combustion behind the region of laser beam focusing without any mechanical flame holders. The laser radiation parameters are sufficient for creating a quasi-steady plasma in the flow. It is shown that the optical discharge stabilizes the flame front in a wide range of equivalence ratios for flow velocities up to u = 200 m/s. The laser radiation parameters within the range of their variation from one experiment to another exert a minor effect on the turbulent flame velocity. Flame stabilization behind the optical discharge region has some specific features. An important parameter is heat release due to hydrogen combustion. A dimensionless criterion is derived; the turbulent flame velocity is a linear function of this criterion.

Injection of inert particles into a stoichiometric hydrogen-air mixture with velocities ranging from 0.1 to 1.0 of the Chapman-Jouguet detonation velocity is calculated. Resultant flow regimes are analyzed. It is found that an increase in the particle temperature leads to ignition of the mixture, while an increase in the particle velocity leads to detonation wave initiation. Critical conditions of detonation initiation in terms of the particle concentration, particle size, and injection velocity are determined. Various possible scenarios of detonation initiation are demonstrated, depending on the particle diameter and concentration, including regimes with multiple initiation sites. Flow charts are constructed in the plane of the parameters “injection velocity, temperature of particles of various sizes”.

This paper first presents chemical time scale values measured by the PIV method for premixed methane-air and dimethyl ether-air flames depending on the equivalence ratio and the concentration of the inhibitor trimethyl phosphate at atmospheric pressure. Comparison of the experimental results with theoretical estimates made based on the Zeldovich-Barenblatt hypothesis shows their qualitative agreement. The chemical time scale within the accuracy of the experiment depended only on the burning rate, rapidly decreasing as it increases. At fuel-air flame speeds close to and above 0.6 m/s, the results of the experiments shown high accuracy of theoretical estimates based on the Zeldovich-Barenblatt hypothesis.

Heat and mass transfer processes and the rate of fuel oxidation are the determining parameters of combustion of pre-mixed fuel gas streams and an oxidizer and combustion of condensed fuels in a gaseous oxidizer. A correct description of these processes is of both scientific and practical interest. The influence of the kinetics of chemical reactions and diffusion of fuel molecules on the thermal and chemical structure of the flame forming around a polymethyl methacrylate (PMMA) sphere under f natural convection in the air has been studied by numerical simulation. The three-dimensional gas flow around the solid body was calculated on the basis of the system of full Navier-Stokes equations for a multicomponent mixture taking into account diffusion and heat exchange between the surface and gas, convection, and radiation heat transfer. The kinetic model represents conjugate reactions both on the surface of the condensed material and in the gas phase. The formation of gaseous fuel methyl methacrylate (MMA) on the surface is described by a one-step efficient PMMA pyrolysis reaction. The oxidation of MMA in the gas phase is described by the global reaction C₅H₈O₂ + 6O₂ → 5CO₂ + 4H₂O. It has been found that the temperature and flame species concentration profiles practically do not depend on the rate constant of this reaction provided that the characteristic reaction time is much less than the characteristic time of MMA diffusion. It has been shown that varying the diffusion coefficient of MMA has a significant effect on the thermal and chemical structure of the flame. An increase in the diffusion coefficient of MMA leads to an increase in the maximum flame temperature. The results of the study show that the transport properties of compounds required to calculate their transpot coefficients are one of the most important parameters for accurate CFD simulation.

This paper presents the results of a chromatographic analysis of gaseous products formed during the laser synthesis of catalytic Cr/Al₂O₃ nanoparticles in a methane-argon environment. The main difficulties of such studies are noted. Methods for solving this problem and ways to optimize the methane pyrolysis accompanying the laser synthesis of nanoparticles are proposed. The fundamental possibility of simultaneous synthesis of catalytic nanoparticles and their use for methane pyrolysis is demonstrated. The main products of pyrolysis in this process are hydrogen and amorphous carbon. The maximum hydrogen yield is 4% (vol.). It is shown how the process can be optimized to increase the yield of hydrogen and expand the range of reaction products for unsaturated hydrocarbons.

The properties of azidoacetylene derivatives of s-triazine containing various combinations of propynyloxy, propynylamino, methylpropynylamino and azido groups have been studied, and their enthalpy of formation in the condensed phase, density, and impact and friction sensitivity have been determined. Based on these data, the energy parameters of the detonation, combustion, and adiabatic transformation of both individual compounds and their compositions with SKI-3 binding isoprene rubber have been calculated. The results of the integrated experimental and theoretical studies lead to the conclusion about the high calorific value of the investigated individual compounds and compositions based on them.

The ignition and combustion characteristics of a high-energy material containing ammonium perchlorate, butadiene rubber, and an ultrafine powder mixture of aluminum, titanium, or iron with amorphous boron are presented. An experimental testbed, a CO₂ laser, and a constant-pressure bomb are used to measure the ignition delay time and burning rate of the high-energy material while varying the heat flux density and pressure in the chamber. It is shown that replacing amorphous boron with ultrafine Al/B, Ti/B, or Fe/B in the material reduces the heating time and the moment of flame appearance on the propellant surface due to an increase in the reaction rate and a decrease in the oxidation temperature of these mixtures on the surface of the reaction layer. In this case, the burning rate of the high-energy materials with Me/B at excess pressures increases significantly (up to 240% for Al/B-HEM and up to 120% for Ti/B-HEM at a pressure of 5.0 MPa).

This paper presents combined metal oxide catalysts for the decomposition of ammonium perchlorate, combining two transition metal oxides (iron and cobalt) deposited on the surface of a carbon support. Combined catalysts are obtained by impregnation and chemical precipitation methods. Catalyst samples containing various phases of iron and cobalt oxides are obtained by varying the calcination temperature. The structural and morphological features of the synthesized catalysts are studied using XRD, SEM, and BET methods. As shown by the study performed using differential scanning calorimetry, the synthesized combination catalysts manifest high catalytic activity during the thermal decomposition of ammonium perchlorate, reducing the peak temperature of the high-temperature stage of decomposition by more than 60oC.

The rheological characteristics of struvite-based fire-extinguishing powder mixtures are comparatively analyzed when using hydrophobic silicon dioxide as a functional filler, obtained during a single-stage synthesis by various methods. Infrared spectroscopy, scanning electron microscopy, low-temperature nitrogen sorption-desorption, and other methods are used to investigate the influence of the synthesis method on the textural and structural properties of hydrophobic functional fillers of fire-extinguishing powder mixtures. It is revealed that the key factor affecting the rheological properties of such mixtures is the uniform distribution of the functional filler over the surface of the particles of a fire extinguishing component (struvite). It is proven that the struvite-based powder composition and the developed functional filler are highly effective for fire extinguishment.

Due to the total lack of reliable experimental data on the kinetics of solid-phase transformations at high temperatures, adequate estimates of the ignition and combustion characteristics of real energetic materials are currently unavailable. In combustion theory, balance relations in the form of ignition criteria and in the form of the equivalence principle of the increase in burning rate under the action of a radiation flux corresponding to an increase in initial temperature are used in most cases without sufficient theoretical justification, what can lead to incorrect results. Numerical simulation of the ignition and combustion of model energetic materials can provide the basis to determine the conditions for the correct use of balance relations. In this work, ignition and combustion under the action of a radiant flux have been numerically studied using a model of unsteady combustion of melting energetic materials and the matching coefficients in the balance relations were obtained. It is shown that the values of these coefficients depend on the kinetic parameters of solid-phase transformations and the intensity of the external heating source. It is concluded that it is necessary to continue the theoretical research aimed at developing valid approaches to determining the parameters of global reactions in the condensed phase using data on ignition delay by heat flux and to determining the correct matching coefficients when using the equivalence principle.

A tetrahedral structure model has been proposed to estimate the size of metal agglomerates during combustion of a composite solid propellant. According to this model, oxidizing particles are located at the vertices of a regular tetrahedron, and the internal volume of the pyramid is occupied by a mixture of binder fuel and metal - the so-called pocket. Experimental data are compared with the results of calculations using the tetrahedral model, the Cohen model and the empirical correlations of Hermsen, Salita, Beckstead, Grigoriev, and Duterque. The comparison was carried out for a composite propellants containing ammonium perchlorate, binder and aluminum as an example. It has been shown that in some cases the tetrahedral model predicts the diameter of agglomerates better than the other models.

An attempt to understand the relation between the burning characteristics and thermal decomposition in a wide range of pressure is made in the present investigation based on solid propellants with ammonium perchlorate as an oxidizer and 3,3-diazomethylepoxybutane and tetrahydrofuran as a fuel binder. The burning rate measurement is carried out in a wide range of pressure: 1.0, 3.0, 7.0, 13.8, 15.0, and 20.0 MPa. The inflection point of the pressure exponent for ammonium perchlorate with and without oxalate and the flame extinguishing point both appear at 13.8 MPa. Various mechanisms of burning rate reduction by the quaternary ammonium salt and oxalate are analyzed by theoretical analysis, thermogravimetric analysis, and differential scanning calorimetry analysis. The burning rate and decomposition of the oxidizer and fuel binder with combustion modifiers and their overall impact on propellant combustion are studied. Due to modifiers, a transition between kinetically controlled combustion and diffusion controlled combustion is found to occur.

This study describes a model for initiating an explosive decomposition of composite materials based on high explosives that weakly absorb radiation and ultradisperse metal inclusions under the influence of nanosecond laser pulses. The model is based on experimental results obtained from studying the explosive decomposition of PETN with inclusions of ultrafine metal particles (Al, Ni, Fe). The model serves as a basis for constructing a scientifically grounded algorithm for determining the composition of a material with minimal thresholds for laser initiation of explosive decomposition, which makes it possible to replace most experiments with theoretical calculations and optical-acoustic measurements. The algorithm is verified using data from laser initiation of RDX with inclusions of ultrafine iron particles.

This paper describes a study of explosive parameters of a Bi₂O₃/Al nanothermite mixture with the addition of 1-methyl-3-nitro-1,2,4-triazole (1Me-3H) depending on the content of the latter and the component ratio of a Bi₂O₃/Al basic nanothermite pair. Adding 1Me-3H to the mixture increases the explosive force, but it begins to decrease as soon as the additive content reaches over a certain limit. Depending on the mixture formulation, it is possible to increase the explosive force by 22-29% relative to Bi₂O₃/Al nanothermite. Changing the mixture composition makes it possible to vary the burning rate of Bi₂O₃/Al/1Me-3H within a range of 400-690 m/s in charges 2 mm in diameter and within a range of 120-430 m/s in a 0.1-mm thick layer.

Formal transposition of kinetic data obtained in studying the processes of ignition and low-velocity combustion to supersonic detonation processes most often leads to noticeable underestimation of the critical initiation energy, detonation cell size, and other dimensional parameters of detonation as compared to experimental data. Thus, numerical predictions of the combustible system behavior become less reliable. However, because of the instability-induced non-one-dimensional, nonhomogeneous, and oscillating character of the multifront detonation wave, it is next to impossible to perform reliable experimental measurements of the kinetic parameters of combustible mixtures under the detonation conditions. In the present paper, we propose and approve a method that allows one to get over the above-mentioned limitations by using a technique as close to the detonation conditions as possible. The technique is based on using a decaying shock wave for combustible mixture initiation instead of the classical steady shock wave. Such a decaying wave is formed in the case of reaction failure behind a steadily propagating detonation wave due to its propagation in a channel with sudden expansion (so-called detonation wave diffraction). The basic issues of the technique are discussed, required estimates are made, experimental verification is performed, and results obtained are reported.

Measurements of the electrical resistance of shock-compressed aluminum is used in the present study to estimate the concentration of point defects generated by the shock wave front. The parameters of the physical state of a thin metal sample are found by means of modeling the shock wave processes in the measurement cell. Experimental values of the specific electrical resistance of aluminum are compared with predictions of the equilibrium electrical resistance model. The proposed model ensures an adequate description of currently available reference data on equilibrium isothermal compression and isobaric heating of aluminum. At the same time, the shock wave experiment yields a higher specific electrical resistance than that predicted by the model of the electrical resistance of an equilibrium defectless crystal. The detected difference in the specific electrical resistances testifies to generation of defects of the crystal structure of the metal subjected to dynamic compression. Under the assumption of predominant formation of vacancies, the concentration of defects in aluminum is estimated as a function of the shock wave pressure. The number of defects in the metal increases with an increase in the shock wave pressure. The data obtained are qualitatively consistent with available results for copper and silver, which allows one to claim that generation of defects under shock compression has common specific features for these metals. The physical state of shock-compressed aluminum is thermodynamically nonequilibrium and includes numerous defects.

By means of determining the suspension effect, the authors studied the change in the surface properties of apatite under the action of reagents and ions present in flotation pulp during processing of apatite-bearing ore. It is shown that the ratio of acid-base centers of apatite surface change in interaction with ions HCO₃⁻ , CO₃^2- , HPO₄ ²⁻ , and oleate ions in distilled water and in water after deionization to remove carbon dioxide. The change in apatite surface properties in alkaline water shows up as quantitative superiority of base centers. Such ionization of mineral surface favors adsorption of cations, for example, Ca²⁺, and sets background for more efficient interaction between anion-type agents. The data obtained from the studies of the suspension effect, correlate with the results of infrared spectroscopy of apatite treated by the appropriate agents.

In order to realize the rational utilization of low-grade polymetallic symbiotic mineral resources with low input, typical copper-nickel symbiotic low-grade ores were used as the test object. After careful process mineralogy research on the ore, it was learned that the main valuable elements of the ore were Cu and Ni, and the content of these two elements was 0.16 wt.% and 0.39 wt.%, respectively. The main copper-bearing mineral in the ore was chalcopyrite, and the main nickel-bearing mineral was pentlandite. Useful minerals were finely distributed in ores. Based on the properties of ore, a beneficiation process of one stage grinding → copper/nickel mixed flotation → copper/nickel separation was proposed. A copper concentrate with a Cu grade of 17.08 wt.% and a nickel concentrate with a Ni grade of 4.63 wt.% were obtained by separation. This study provides a low-investment technical solution for the rational utilization of polymetallic paragenetic mineral resources.

The prospects for ecologization of technological paradigm of development in the sector of mineral resources are studied and substantiated with regard to the requirements and constraints, and based on the equal possibilities for the biosphere and technosphere. The notion of the nature-like technologies is structured subject to the coincidence of missions of the content-rich components in the natural and geotechnical systems. The methodology of the homeostatic transformation of the biological system functions into the structure of a cluster on the convergent mining technologies is presented.

The supply of coal-fired thermal power plants with limestone as a sorbent in the flue gas desulfurization process highlights two key issues. Apart from the raw material quality adequate to meet the technological conditions of the installed desulfurization plants in thermal power systems with several potential production and user entities, the question of rational limestone supply arises. The paper presents a multi-attribute ranking model as a possible approach to solving such tasks.

The paper presents the single-criterion modeling of limestone supply under the conditions of the variable structure of the thermal power complex of Serbia. In the end, the paper provides an analysis of the differences between multi-attribute and single-criterion solutions.

As a result of hardware updating of Prognoz-L based on the modern electronic engineering and the accumulated experience, rock mass express-evaluator Prognoz-L.2 has been designed. The test data of the evaluator are presented as a case-study of a rockburst-hazardous mineral deposit.

The article presents the fracture test data of rock samples with the porphyroblastic, granoblastic lepidoblatic and laminated structure. The tests were carried out on lab-scale tester ASI-2. The test samples were subjected to uniaxial compression until discontinuity with synchronous recording of associated electromagnetic emission, load and displacements along the compression axis. The laminated rock samples in fracture show anisotropy of geophysical parameters and electromagnetic emission.