Home – Home – Jornals – Atmospheric and Oceanic Optics 2023 number 7

The comparative analysis of data available from open sources on the water spectral lines intensities in the frequency range from 0 to 1.75 THz has been carried out. The calculations by the method of effective Hamiltonians and the variational method, as well as experimental data were taken into account. It has been established that the intensity uncertainty is less than 2% for lines in the ground vibrational state with an intensity of more than 10^-27 cm/mol. and is about 5-10% for weaker lines. For strong (more than 10^-26 cm/mol.) lines in the ν₂ state, the uncertainty ranges from 2 to 5% and increases to 5-10% for weak lines. For all lines in the 2ν₂, ν₁, and ν₃ states, the uncertainty is no more than 5-10%. The presented data show that most of the considered lines can be assigned a higher (by 1-2 steps according to the classification adopted in HITRAN) category of intensity accuracy.

Results of an experimental study of the influence of argon addition on microwave plasma chemical vapor deposition of diamond from a hydrogen-methane mixture are reported. A specific feature of this method is the use of a high-velocity jet for transporting gases activated in a microwave plasma in the discharge chamber to the substrate located in the deposition chamber. Optical emission spectroscopy is used for systematic investigations of the microwave discharge plasma in the discharge chamber. Diamond coating samples obtained on the molybdenum substrate are studied by methods of scanning electron microscopy and Raman scattering spectrography.

The present numerical study is aimed at revealing the influence of the distance between the nozzle exit and the resonator edge on the gas-dynamic characteristics of the acoustic-convective flow in the flow path of a bichannel system. The aim of the work is the development of a computational technology for describing the physical processes in the flow path of multichannel systems that generate high-intensity acoustic fields. Five configurations of the bichannel system were considered, where the gap was 0.85, 1.10, 1.35, 1.60, and 1.85 of the resonator diameter. As a result of the study, a complete picture of the gas-dynamic flow formed in the flow path of the bichannel system was obtained, including the resonating cavity and the region in between the nozzle and the resonator. With the help of numerical simulation, the formation of a flow with high-frequency, low-amplitude oscillations at a small gap between the nozzle exit and the resonator edge, which was observed in experiments, has been demonstrated. Pure-tone oscillations with maximum intensity occur when the resonator is placed in the region of the beginning of the second barrel, this observation being in good agreement with the data by other authors. Subsequent increase in the distance between the nozzle and the resonator leads to the emergence of subharmonics and multiple harmonics. Verification of gained numerical results with known experimental data is carried out.

Modeling of processes with phase transition in confined spaces needs high-accuracy simulations with account for non-equilibrium. In the present paper, we use the direct simulation Monte Carlo method for describing evaporation into a vapor-filled half-space with a subsonic monoatomic gas flow. Two types of boundary conditions for open half-space are considered: the interaction approach with consecutive calculating of temperature and pressure, and the approach with a fixed velocity. We compared these approaches for obtaining the accurate solution of the problem. The fixed-velocity approach provides a higher accuracy for the flow with a low Mach number. The calculated results are compared with a known solution of a model kinetic equation.

The present work deals with the design optimization of different vehicle configurations for planetary entry. Choosing the aerothermodynamic characteristics of heat flux and drag as the objective function we have analyzed and simulated the effects of atmospheric resistance on planetary entry vehicles in the rarefied atmosphere. We have utilized the SPARTA (Stochastic PArallel Rarefied-gas Time-accurate Analyzer) DSMC simulator for our simulation. The optimization is carried out with the help of MATLAB optimization module. We have simulated the descent of the present work demonstrates two of the planetary atmospheric conditions, the first one is Earth, and the later one is Mars. The vehicle geometry is then optimized according to the planetary atmospheric conditions. This work ultimately provides insight into how the effects of geometrical parameters play a pivotal role in the aerothermal loads of planetary entry vehicles.

The problem of laminar mixed convection is considered in a flat vertical channel with lifting and lowering flow and liquid heating, i.e., for cases of coincidence of the directions of free and forced convection, as well as their opposite directions. The solution of the system of equations of motion, continuity and energy is performed by the finite difference method. Data on the profiles of the longitudinal velocity, temperature, and Nusselt numbers at the lifting and lowering flows have been obtained. An explanation is given for the peculiarities of these values under the influence of buoyancy force. All components of the hydraulic resistance coefficient for lifting and lowering flow have been analyzed. The influence of the Prandtl number and the velocity profile at the channel input on the hydrodynamic and thermal characteristics of the flow is considered.

Within the framework of the linear subsonic theory, the problem of influence of flow boundaries on the flow around airfoil according to the measured distribution of pressures on the airfoil and on the test-section walls is solved. For the test case (testing a BGK1 airfoil in the IAR1.5m wind tunnel), we compared the corrections to the oncoming-flow Mach number and to the airfoil angle of attack that were obtained using our method and in works by other authors. For a OSPB-77 airfoil model tested in the T-128 wind tunnel for two values of wall permeability, ƒ = 0 and 3 %, correction of distributed data and integral loads was applied in the range of Mach numbers from 0.2 to 0.78. The application of corrections has made it possible to bring the results for ƒ = 0 and ƒ = 3% in closer agreement up to the angles of attack at which flow separation occurs on the airfoil.

The structure of a slug gas-liquid flow and interfacial mass transfer during the flow of ethanol-N₂ and ethanol-CO₂ mixtures in a horizontal rectangular microchannel have been experimentally studied. The experiments were carried out in a straight microchannel with a cross-section of 380×190 µm. To determine a change in the volume of a gas slug along the microchannel length, the method of high-speed visualization with digital processing was applied. In a wide range of gas flow rates, the repetition rate and the volume of gas slugs and their velocity were measured, and he volumetric coefficient of mass transfer from liquid was determined for the ethanol-CO₂ mixture. A physically substantiated model of interfacial mass transfer for a slug flow in a channel of rectangular cross-section, which takes into account the circulation flow in a liquid bridge, is proposed.

One of the promising methods of geophysical research in operating wells is active thermometry. The method consists in creating an artificial temperature field in a well due to local heating of the metal casing. Observation of heat tags movement enables determining the fluid flow rate in the well and identifying the intervals of the behind casing flow. The article is devoted to the study of non-stationary thermal processes in a well during induction heating. The calculations were performed in the commercial simulator Ansys Fluent*. It was established that with an increase in the volumetric flow rate through the column from 5 to 50 m³/day for the modeling conditions, the maximum heating of the liquid (a change in the average mass cross-section temperature) is reduced by 85%, and the maximum heating of the column is reduced by 7%. The influence of natural convection on the formation of a temperature field in a liquid and a column has been studied. For the model with natural convection accounted, the column heats up significantly less than for the model without convection: the error in calculating the temperature changes due to neglect of natural convection can reach several hundred percent. During the process of induction heating for the casing, the effect of natural convection remains significant throughout the entire flow range of 5-50 m³/day.

The flow of liquid over the corrugated sheets of regular packings largely determines the processes of heat and mass transfer in distillation columns. An important role in the distribution of liquid over the structured packing sheets is played not only by the characteristics of packing surface microtexture, but also by the drip point location in the liquid distributor relative to the sheets in the structured packing plugs. It has been established that even a slight displacement of the drip point relative to the channels of a regular packing can lead to noticeable redistribution of liquid over the packing sheets. Knowledge of the detailed structure of the flow in the distillation column allows better understanding of the physical nature of the mechanisms that control the flow. It is shown experimentally that the negative impact of the uncertainty associated with the drip point position on the liquid distribution under a layer of structured packing can be reduced using liquid redistributors in the form of inclined plates with horizontal microtexture.

Three-dimensional numerical simulation of a transverse hydrogen jet blowing into a duct with a supersonic flow of air (warmed by a fire heater) has been carried out. The study is based on experimental data obtained at the ONERA-LAERTE facility. The RANS equations for the reacting gas were solved, closed by the SST model and various kinetic mechanisms of hydrogen combustion in air. The channel walls roughness was taken into account. The dependence of the flow characteristics on such physical factors as the shape of the fuel injector channel, the effective roughness height, and various methods of describing molecular diffusion has been studied. It has been established that the equivalent diameter of a grain of sand has a significant influence on the longitudinal pressure distribution in the duct. The influence of chemical kinetics on the flow structure in separation zones within the duct is demonstrated.

The study presents the results of simulation and experiment for motion of a supersonic two-phase jet passing through a round aperture in a mask. The mask is placed at different distances from the deposition substrate with performing the cold gas spraying. The calculations were performed using the fluid dynamics code ANSYS Fluent; flow visualization is achieved using the Schlieren method. Solution analysis and comparison of results were performed for example of aluminum powder spraying.

Phenol oxidation in a water-oxygen fluid in a tubular batch reactor with its uniform heating (1°C/min) to 600°C was studied. An increase in the amount of O₂ over the stoichiometric ratio by 25% leads to an increase in the degree of carbon burnout by the factor of 1.09. Replacing 10% of the stoichiometric amount of oxygen with nitrous oxide leads to the same increase in the degree of carbon burnout, primarily due to its afterburning at a temperature of ≥ 400°C. Replacement of some part of phenol with isopropanol leads to an increase in the degree of carbon burnout by 1.02 times. It was established for the first time that the heterogeneous mechanism of phenol oxidation in a water-oxygen fluid is the main one. However, the overstoichiometric amount of O₂, as well as the addition of N₂O and isopropanol, intensifies gas-phase combustion of carbon. A catalytic effect of a Pt-Rh/Pt thermocouple on the degree of phenol conversion in the presence of O₂ at temperatures above 135°C was found.

The enthalpy and heat capacity of solid and liquid Mg₂Ca intermetallic alloy were measured with the help of mixing by massive high-temperature isothermal drop calorimeter over the temperature range of 298.15-1177 K. The estimated errors in the data on enthalpy and heat capacity were 0.2% and 2%, respectively. The fusion enthalpy of the Mg₂Ca intermetallic alloy was determined to be 483 ± 3 J/g. The heat capacity of the Mg²Ca melt was shown to be constant in the range of 993.2-1177 K. A comparison of the obtained results with literature data has been carried out.

The presented paper considers a number of problems. The first of them concerns the analysis of experimental (ρ_l, ρ_g, T)-data for SF₆ at relative temperatures (1,5∙10^-8< τ < 0,3). The second task is related to the development of combined models (ρ_l(D, C, τ), ρ_g( D, C, τ), … ), that agree with a number of boundary conditions, including the requirements of the scale theory of critical phenomena. The third task is to calculate (D, C)-parameters included in the combined models; at this stage, a basic array of (ρ_l, ρ_g, T)-data is formed, including experimental results obtained in the laboratory of Prof. Funke (Germany), and (ρ_l, ρ_g, T)-data obtained by recalculating the results in the laboratory of Prof. Garrabos (France). The models for (ρ_l(D, C, τ) and ρ_g(D, C, τ) served as the basis for calculating some thermodynamic properties of SF₆ in the critical region.

Using the method of differential scanning calorimetry, the heat capacity of Mg-Ca alloys containing 10.50, 33.34, and 73.00 at. % Ca, being promising for various practical applications (biocompatible and biodegradable alloys, ultralight construction materials, anode materials, hydrogen absorbent materials, etc.) has been studied experimentally. New reliable experimental results on the specific heat capacity in the temperature range of 190-576.692 K of the solid state have been obtained. The estimated errors of the received data were 2-3 %. The reference tables for temperature dependences of specific heat capacity of Mg-Ca alloys have been compiled. It has been established that over a wide temperature range the heat capacity of solid magnesium-calcium alloys can be estimated with high accuracy using the Neumann-Kopp rule.

The paper describes an algorithm that using numerical methods allows calculating the relationship between the temperature of the spectral ratio and the actual temperature of a "non-gray" object, which takes into account not only the dependence of the spectral emissivity of the object on the wavelength, but also its temperature dependence, inherent in almost all real objects (materials). This algorithm is applicable to any pyrometers of spectral ratio: narrowband and broadband ones. Previously, both in domestic and foreign literature, there has been no solution to the specified problem which would simultaneously consider both dependences. The proposed solution is based on a well-known algorithm that allows calculating the relationship between the temperature of the spectral ratio and the actual temperature of a "non-gray" object, taking account only the dependence of the spectral emissivity of the object on the wavelength. The presented algorithm has been modified to consider its temperature dependence as well. An example of the implementation of the described algorithm is given.

The results of an experimental study of the thermal expansion of gallium garnets Gd₃Ga₅O₁₂, Gd_3.04Sc_1.8Ga_3.16O₁₂ and Ca₃Nb_1.5Ga_3.5O₁₂ in a wide temperature range (293.15 - 1473 K) are presented. A noticeable effect of niobium in the structure of gallium garnets on the coefficient of thermal expansion has been found. The temperature dependences of the volumetric properties have been obtained.

Here we present the results of thermodynamic and kinetic calculations as well as experimental studies of plasma processing of rubber powder of recycled tires, demonstrating the promise of using the plasma-chemical technology for gasification of this powder with the production of energy gas. The results of experiment and calculations were compared and showed good agreement.

The authors attempt the numerical modeling of the geomechanical behavior of a rock mass in the course of single unit face longwall mining. The calculation models are constructed for the rock mass geomechanics from ground surface down to mining depth. The model problems are solved in two and in three dimensions. The resultant characteristics of a trough subsidence on ground surface were compared with the data of engineering analysis. The modeling results are verified using actual in-situ observations of check point subsidence. The comparative analysis of the trough subsidence characteristics on ground surface from the geomechanical modeling and engineering analysis show their correlation in case of all test alternatives.

The coal freezing adhesion tests on typical substrates including metal, rubber and plastic substrates were carried out, the steady and separated interfacial structures between coal and substrate surfaces were investigated, and the strength characteristics of coal freezing adhesion on substrates were analyzed in depth. At the stable interface of coal freezing adhesion, the frozen coal slime area is formed in some areas, while the direct contact area as well as the void area may appear between the frozen coal and substrate surface in other areas. The surfaces of metal and rubber substrates have small water contact angle and good wettability, and the separation failure of freezing adhesion occurs at the interior of the frozen coal slime area or the frozen coal itself, thus the coal freezing adhesion strength is reflected by the freezing strength of the frozen coal slime or the frozen coal itself. The surfaces of plastic substrates have large water contact angle and poor wettability, and the separation failure occurs at the bonding interface between the frozen coal slime area and substrate surface, thus the coal freezing adhesion strength is reflected by the bonding strength. The coal freezing adhesive strength on plastic substrates is 4-12 time less than on metal and rubber substrates.

In this study, the rebound hardness values (Shore-Schmidt-Leeb) were calculated for 12 different carbonate rocks using three different devices. The relationships between hardness values and rock cuttability properties (specific cutting energy and noise level) were investigated by simple and multiple regression analyses. It is determined that the Leeb hardness of the rocks can be an alternative to the Shore hardness and Schmidt hardness and that both the specific cutting energy and the noise level can be estimated with the Leeb hardness values.

This study examines the usability of concrete wastes generated from buildings demolished for various reasons in shotcrete. The strength properties of shotcrete produced from recycled aggregates (RA), cylinder specimen and plate specimen were tested. it was observed that as the ratio of RA used instead of natural aggregate increases, the strength of the cylinder specimen decreases, ultrasonic pulse velocity increases. The toughness value has increased in the concrete samples prepared by replacing the natural aggregate with 50% or more RA. It was observed that the fiber amount and load carrying capacity were proportional in fiber reinforced plates prepared using RA. As a result, it has been observed that the interaction of RA with fiber is positive and it can be used in shotcrete. It has been revealed that RA can contribute to the reduction of environmental pollution caused by construction and wreckage wastes and can be presented as an alternative to natural aggregate.

The authors discuss the mechanisms of gas transfer in exposed coal on the strength of the phenomenology of coal gas content. The phenomenon of gas transfer is divided into flow and diffusion, and the major characteristics of these processes in the overall gas travel are revealed.

The authors make a geomechanical assessment of undermined rock mass before and after formation of a sinkhole on ground surface during blind orebody mining on Podruslovy site. The geophysical surveys allowed finding the pillar size dynamics above the mined-out void. The borehole gravity measurements in integration with an orthophotomap made it possible to determine the boundaries of the mined-out void and the parameters of the sinkhole. The mathematical modeling estimated the zones of stress concentration and fracture in enclosing rock mass in the neighborhood of the test boreholes. The safety precautions are designed for the further mining operations on Podruslovy site at Sheregesh deposit.

The usability of salt mine water with high content of chloride-ions in preparing cemented paste backfill is studied. The rheological and mechanical properties of experimental backfill mixtures at different cement consumption are analyzed at uniform and compound aggregate hydrated with tap and mine water with the content of chloride-ions up to 0.75% of the mass of cement. The strength, elasticity modulus and Poisson’s ratio are calculated in cemented paste backfill with tap and mine water after curing for 28, 60, 90 and 360 days. It is found that the strength, elasticity and deformation characteristics of the test cemented paste backfill made of mine water change similarly to the backfill made of tap water, at deviation of ± 10% and ± 4% in terms of strength and deformation, respectively. Chloride-ions contained in mine water have no adverse effect on rheological properties of backfill or hydrated cement, and on dynamics of development of strength in the mixture.

It is examined how convergence of roof and floor affects condition of temporary roadways during extraction of coal series in Kuzbass. The geological and geotechnical factors that can cause deformation in roadways are identified. Roadways are classified in terms of their location relative to a coal seam being mined and a coal seam being overmined in a coal series. The parameters and phases of deformation of rocks are analyzed as primary and secondary convergence of roof and floor rocks in temporary roadways. The primary convergence is observed in temporary roadways located in parallel to the mined-out void and driven in the bottom layer of a thick coal seam being overmined. The secondary convergence takes place in temporary roadways in the abutment pressure zone induced by the earlier mined-out extraction site.

The authors perform the aerodynamic design of axial fans with impeller and inlet guide vane to reverse air flow direction via killing rotation of the impeller while putting the guide vane into rotation. This approach can substantially enhance fan efficiency in reverse mode. The newly developed blade angle analysis procedure allows finding air flow parameters in reversal. The parametric regions in aerodynamic designs of axial fans, where the proposed approach of reversal is effective, are delineated. Design of a fan having similar aerodynamic characteristics in the forward and reverse air flow is undertaken. The swirl ratios of flow in the guide vane are correlated with the axial velocity ratios toward geometrical similarity of blade profiles of impeller and guide vane at an average radius.

A brief review of machines for pit wall scaling is given. The inertial impact technique is compared with the surface miner operation. The authors describe an inertial impact machine with a hammer rotor for pit wall scaling. The procedure and data of the numerical and lab-scale testing of the machine are presented. The tests produced the rational range of lip angles for hammer plates and the preferable impact frequency, which ensure the minimized energy intake of the rotor motor and the least counterforce of rock mass to the bearing seat of the rotor at the preserved efficiency of fracture process.

The found interaction mechanism between a mineral-diamond mixture and a modifying agent includes the stage of adhesive attachment of luminophore at grains of diamonds and kimberlite. The selected compositions of modifying agents and the modification process parameters ensure efficient attachment of luminophore-bearing compositions at diamonds. The proposed criterion of selective action of modifying agent on spectral characteristics of diamonds enable choosing modes of recovery of weak and high luminous diamonds from kimberlite ore in X-ray luminescence separation. The rational variation parameters are determined for the organic collector composition, water phase of a modifying agent and for the process of modifying treatment of diamond-kimberlite products before the X-ray luminescence separation. The test of the selected compositions of modifying agents and the diamond-bearing product treatment modes proved almost complete extraction of weak and high luminescence diamonds to concentrate at minimized yield of kimberlite.

The literature review discloses preferability of using the time of induction rather than the wetting angle as a criterion of coal floatability. The authors analyze kinetics of coal flotation as function of surface properties of heteropolar collectors relative to the gas-liquid interface. The correlation between the spreading velocity of collectors on water surface and the coal flotation kinetics is determined as a case-study of fat coal slurries. Justification is given for using the time of displacement of the boundary between three states of aggregation as the time of induction. From the correlation of the spreading velocity of a collector, displacement time of the contact line (induction time) and the flotation velocity, it is found that flotation activity of the collector is governed by its properties relative to the gas-liquid interface.

The article proves the promising nature of joint roasting of rebellious oxidized and sulfide lead-and-zinc ore from Ozerny deposit at the stage of ore preparation for flotation. The joint roasting of lead-and-zinc ore and sulfide ore initiates generation of sulfur-containing agents and sulfidation of rebellious oxidized lead and zinc. It is experimentally proved that selective oxidation of pyrite proceeds together with disintegration of lead and zinc along the interphase boundaries. The main products of such interaction are ZnS, PbS, Fe₃O₄ and Fe₂O₃, which can greatly facilitate flotation later on. This method of complex ore processing can potentiate commercialization of oxidized lead-and-zinc ore and rebellious sulfide ore, can prolong service life of mines and mitigate the environmental impact of the industry. The produced samples are analyzed and described using the X-ray phase analysis, differential scanning calorimetry, optical microscopy, chemical analysis, Rietveld refinement and program TOPAS.

Consumable supplies in mines (explosives and explosive devices, oil, lubricants, rubber, protective devices, spare parts for machinery and equipment, flotation reagents, etc.) should be sufficient for stable production. However, for mining operations, supplies are burden costs, as storing supplies increases operating costs. The logical question is how to achieve the balance between mine production stability and minimization of costs of supplies, that is, how to optimize supplies. The paper presents a quantitative model of stochastic supplies optimization as a possible answer to this question. The application was demonstrated in the specific case of polymetallic ore lead, zinc, copper, and silver mine flotation with value indicators.

The authors discuss the mineral resources and mineral reserves of the Russian Far East in terms of their volume and production of certain minerals. The key challenges of subsoil use, which complicate advancement in the mining sector at the present time, are identified. The growth prospects of the mining sector can build on the processing industry and on the transition from mineral extraction to mineral production at high degree of conversion. The economic efficiency of subsoil use depends on the professional corporate management, transportation and power generation infrastructure, sound scientific grounding and on the development of the processing industry which uses products of the mining industry. The main trends of the spatial development in subsoil use are proposed. The large infrastructural projects are described, which can promote social and economic progress in the Far East Federal District of Russia. Emphasis is laid on improvement of personnel potential and on introduction of scientific supervision in the mining and processing industry in the region.

The authors present a multi-factor algorithm for making provisions for geological/geotechnical constraints and operation timing criteria subject to availability of resources. The algorithm enables embracing a variety of possible combinations of heading or stoping conditions at each specific underground mine facility. The algorithm is a part of the digital tool of automated underground mine production planning in geological and mining information system MINEFRAME.

The authors examine the present-day hydrogeological situation and its post-mining phase forecast in the Chelyabinsk Coal Field. Geotechnical facilities in the areas of Krasnaya Gornyachka Mine and Kopeisk and Korkino Open Pit Mines are discussed. The problems to arise during flooding are identified. The hydrological forecasts and an action plan to prevent underflooding in the study areas are presented.

The article presents the case-study of properties of domestic binders in dust suppression at tailing storage facilities at a mining and processing plant in the Murmansk Region. The strength development dynamics of the binder-formed blankets and the change in the strength in the wetting-drying mode are determined, the impact of chemical agents on water permeability of treated tailings is estimated, and leaching of polymerized concentrates in weakly acid and alkaline media is carried out. The authors emphasize essentiality of an integrated research for the well-founded choice of a binder.

In the study, the particulate matter (PM) measurements were carried out during several blasting operations using a portable Cascade Impactor with eight particle size fractions. The particle mass size distribution was characterized for each blast shot. The PM dispersion trend equations were established for using the measurements collected from various distances in the downwind direction and classified for different fractions (respirable, thoracic, and inhalable) to assess the health risks. As an outcome of the study, the amount of dust generated in the blasting source was specified according to the blasting theory. The PM dispersion trends were established by evaluating measurement results. It was concluded that, PM decreases from gram to milligram grades in the first 100 m distance. All of the PM fractions ultimately settles at an approximate distance of 535m and not spread out of the quarry pit. Regarding particle mass size distribution studies, blast-induced PM is classified as fine particles. The study has preceded features regarding both PM sampling during a blasting event and revealing PM fractions close to the blasting point. The context also provides a detailed comparison of the amount and characteristics of dust caused by blasting with other activities.

The authors investigate geophysical parameters of water-saturated and frozen rock samples, and compare the results with the data of natural rocks. The samples were subjected to dynamic loading, an acceleration signal was recorded and a spectral density was calculated. On this basis, later on, the authors determined the longitudinal vibration velocity, the logarithmic decrement of damping, the internal friction factor and the acoustic Q-factor. The water-saturated and frozen rock samples demonstrated the increased velocities of longitudinal vibrations. The samples, which had the high acoustic Q-factors in the frozen conditions, fractured under much higher loads. The degree of water saturation affected the strength of the test samples: their strength reduced with the higher water saturation. Freezing of the samples generated microseismic vibrations in the region of high frequencies. In the uniaxial compression tests to failure of the samples under critical loading, a high frequency signal was recorded during initiation of an extension fracture, and the signal spectrum shifted toward lower frequencies as the fracture grew.

Article analyzes scientific achievements and heritage of Elena Grigor’evna Minina - famous Russian scientist, biologist, plant physiologist (24.04.1903 - 01.04.1989). Being an outstanding researcher in many fields of reproductive biology and plant physiology, E. G. Minina created the doctrine of sex determination and sexual reproduction in plants and the influence of phytohormones on the processes of sexualization. She considered the course of the processes of sexualization as a complex chain of chemical transformations, primarily the redox system and hormonal regulation. Elena Grigor’evna determined the directions of the studies under environmental stress, laid the foundations for studying the patterns of morphogenesis, sexual transformations in woody plants. She was the first to describe sexual transformations in the Siberian stone pine ( Pinus sibirica Du Tour) trees with acceleration of the reproductive cycle. These forms show signs of apomixis, characteristic of thriving angiosperms. Much attention in Elena Grigor’evna’s research was paid to elucidating the role of gravity in the processes of growth, formation and seed-bearing in coniferous plants. The criterion of the initial stage of atmospheric pollution, in her opinion, may be the direction of growth of lateral shoots. She is particularly interested in the problems of evolutionary physiology and reproductive biology of plants, provides schemes of phylogenetic relationships in the evolutionary development of angiosperms and gymnosperms. The level of evolutionary advancement of taxa and individuals within the species, in her opinion, is manifested in the intensity of photosynthesis, carbohydrate-nitrogen metabolism, biosynthesis of gibberellins and growth processes. According to Elena Grigor’evna’s teaching, a biotechnology of somatic embryogenesis of coniferous species is being developed, in which somatic cells in in vitro culture switch to the path of embryonic development, forming numerous embryos and plants with selectively significant traits. The list of the main scientific publications and the list of dissertations defended under his supervision is given.