Home – Home – Jornals – Thermophysics and Aeromechanics 2023 number 4

The placer deposits of the Miass valley in the Southern Urals have been known since the beginning of the 19th century. Over two centuries of mining more than 120 tons of gold have been extracted from alluvial and alluvial-deluvial placers. Despite the industrial significance of this territory, native gold of alluvial deposits is practically unstudied and there is no data on the mineral composition of concentrates. Native gold and heavy fraction minerals from seven placers of the Miass placer zone of deluvial-alluvial and alluvial types were researched. The study of the typomorphic features of native gold and distribution of heavy fraction minerals in loose deposits makes it possible to determine the genetic types of primary sources of placer formation. Chrome-spinel and ilmenite prevail in the concentrates, magnetite, epidote, rutile, titanite, clinopyroxene, hematite, zircon, garnets, and monazite are less common. Chromespinelides of various placers are represented by chromite and subferrichromite, they are characterized by a high average content of Cr₂O₃ (50.9 wt.%). Chromespinelide chemical composition features show evidence of its penetration into placer sediments from rocks of the ophiolitic association. The composition and morphological features of phosphates of rare earth elements (monazite and xenotime) indicate their metamorphogenic nature and penetration into placers from the Riphean strata. Native gold is characterized by a low degree of roundness. Mineral inclusions in native gold are represented by sulfides, arsenides, bismuthides, cuprous gold, platinoids. Composition of native gold from the Miass River valley placers varies over a wide range. The main admixtures are silver (4.5-23.4 wt.%) and mercury (up to 5.14 wt.%), copper (up to 2.03 wt.%) was noted in several grains. The EBSD study of native gold internal structure showed predominance of primary crystallization structures, a low degree of deformation and growth of gold-rich rims with a fine-grained mosaic structure. Formation of gold-rich rims in gold grains in placers is explained by recrystallization of the most deformed parts of gold during transportation. Placers occurred due to the destruction of primary sources located in the upper reaches of streams or near them, which is confirmed by a low degree of grains’ roundness. The composition of native gold in combination with a set of micro-inclusions indicate the gold-sulfide-quartz type of mineralization of most primary sources.

We have studied the trace element composition of apatite from several varieties of carbonatites and associated apatite ores of the Vuoriyarvi alkaline-ultrabasic carbonatite complex (Kola region, northwestern Russia), which hosts several commercial deposits of apatite-magnetite and pyrochlore ores and large-scale unexplored rare-earth mineral occurrences. The composition of apatite was analyzed by total-reflection X-ray fluorescence spectrometry (hereafter, TXRF). Verification of the obtained results was carried out by ICP-MS analysis of weighed portions of apatite monomineral samples. It is shown that during the evolution of the Vuoriyarvi carbonatites and associated apatite-magnetite ores, the contents of Sr and rare-earth elements (REE) and the degree of REE fractionation in apatite synchronously increased. The obtained TXRF data on the composition of apatite in the carbonatite complex demonstrate the efficiency of TXRF and its high potential in both applied and fundamental research concerned with apatite of various geologic objects.

Cores of Holocene bottom sediment collected in the East Siberian Sea revealed layers with mixed textures and layers with breaks in sedimentation corresponding to the two sea levels defined as modern (upper) and Early Holocene (lower). The layers are characterized by distinctly chaotic variability in textural pattern (mottled appearance, multidirectional banding), colorimetric and geochemical parameters (sawtooth-like distribution curves). Such character of changes is associated with the physical action of dragging keels of ice/icebergs exerted on the seafloor and is referred to as ice gauging (scouring). Its analysis can be used for identification of ice scour-affected layers in other sediment cores collected in this region, and for the purpose of creating a representative database, predicting their occurrence and developing adequate measures to minimize the damaging impact from drifting sea ice and icebergs on the seafloor within the bounds of the Arctic shelf.

This paper describes a set of studies performed at a thermal manifestation (Lake Utinaya Banya) on the Iturup Island (Kuril Islands). These studies include bathymetric survey of the lake basin, geometric leveling across the lake, pitting, sampling of thermal waters from the lake and springs, hydrochemical research, and isotopic analysis of oxygen and hydrogen in the lake water. It is suggested by the shape of the lake basin (close to lenticular with a significant concentric depression), the underwater gas-hydrothermal vents, the bank along the perimeter of the lake basin, and the presence of several layers of clastic deposits at the top of the rampart that the lake was formed by a hydrothermal eruption. The lake temperature has remained constant over the years and ranges on average from 25 to 15 °C, depending on the season. The water of Lake Utinaya Banya is represented by acidic, sulfate calcium, and low-mineralized waters.

Shoulder beds may have a significant effect on the resistivity log responses. This problem is especially acute in studies of complex strata composed of thin beds with contrasting properties. Different approaches to taking account of the shoulder-bed effect on logging signals are known, such as correction charts, deconvolution operations, and using advanced algorithms of numerical data inversion, which allow one to consider the vertical inhomogeneity of the section. The best result is achieved using the inversion toolkit, but the high labor- and resource-intensiveness of the approach limits its widespread use. The deconvolution approach does not have these disadvantages, but it does not take into account the influence of radial changes in the medium properties on the shapes of measured signals.The possibility of using artificial neural networks (ANN) to increase the vertical resolution of the measured logging data is explored. We assume the existence of a deconvolution-like transformation in which change in the medium properties in the radial direction is also considered. In this case, we can find its approximation using a neural network. The approach is demonstrated by creating a transformation algorithm for the high-frequency electromagnetic logging (VIKIZ) sounding tool, which is widely used in the CIS countries for petroleum exploration. The developed algorithm has been tested on the VIKIZ logs from the Fedorovskoe oilfield (Latitudinal Ob’ region).

The paper presents new data on the chemical and mineral compositions of ultramafic rocks and various gabbro of the Birkhin massif in the Ol’khon region. Porphyric phenocrysts and zoned grains of clinopyroxene have been first found and studied in gabbronorite, which made it possible to reconstruct the entire melt crystallization trend from ultramafic to gabbro parageneses. Similar clinopyroxene trends have been established for clinopyroxenites and subvolcanic ankaramites, whose bodies and dikes have been recently discovered within the massif and in its environment. The total petrological data show that the magnesian high-Ca ankaramite melt corresponds in composition to the assumed primary melt for the Birkhin massif.

The tectonothermal evolution of Transbaikalia is reconstructed using U/Pb, ⁴⁰Ar/³⁹Ar, and apatite fission track thermochronology of samples from the Late Paleozoic Angara-Vitim granitoid batholith (AVB). Successive closure of the zircon and amphibole isotope systems provides evidence that the AVB rocks cooled down rapidly soon after crystallization and 4-7 km of rocks were denuded subsequently during an extensive late Paleozoic orogeny in southern Siberia. The isotopic system of feldspar closed in the Middle Jurassic-Early Cretaceous (170-140 Ma) after a period of tectonic stability and slow closure of the biotite isotopic system in the early Permian-Middle Jurassic (295-170 Ma). The 170-140 Ma span was the time when the Mongol-Okhotsk orogen began its evolution, and the orogeny caused denudation of ~3 km of rocks. Denudation was slow in the Paleogene-Miocene (60-5 Ma) but accelerated over the past 5 million years (a ~2-3 km thick layer) during rapid cooling of rocks and activity under a far-field effect of the India-Eurasia collision.

We present the results of comprehensive studies of Holocene bottom sediments from the shallow hypersaline (mineralization up to 282 g/L) Lake Bolshoi Bagan, located in the East Baraba lowland (south of Western Siberia). The research methods include X-ray diffractometry (XRD), IR spectroscopy, laser granulometry, scanning electron microscopy, elemental analysis of sediments and pore water, radiocarbon (¹⁴C AMS) dating. It has been found that during the Holocene an intensive authigenic mineral formation took place in the lake basin; gypsum, halite and carbonates of calcite-dolomite series dominate among the newly formed mineral phases. Mg-calcites with different Mg contents, excess-Ca dolomites, aragonite and occasionally Mg-siderite have been found in the assemblage of carbonate minerals by mathematical modeling of complex XRD patterns. Mineralogical and crystallochemical studies, supplemented by the results of geochemical analyses, allowed us to identify four stages of the evolution of Lake Bolshoi Bagan in the Holocene, due to regional climate variations. The boundaries of the stages in general correspond to the boundaries of the climatostratigraphic phases by the Blytt-Sernander system: Stage I (the end of the Boreal) - the lake formation, humid climate; Stage II (Atlantic) - climate aridization, shallowing of the lake; Stage III (Subboreal) - unstable climate, frequent change of conditions; Stage IV (Subatlantic) - moderately cool and dry climate.

The continuous growth of geomagnetic observations requires adequate methods for their processing and analysis. On the other hand, many studies in the field of geomagnetism require accurate and reliable measurements from both ground and space. Mathematical methods of geoinformatics can provide a solution to these problems. The article describes the progress made in the field of intellectual analysis of geomagnetic data continuously recorded by magnetic observatories and low-orbit satellites, demonstrates the results in the study of rapid variations of the Earth’s core magnetic field associated with the processes in the Earth’s deep interior, and presents the investigation of near-Earth electromagnetic dynamics. The applied value of the obtained results is also shown.

The Angara regional fault which is transversal to the Baikal basin totals about 150 km in length and ranks as a major strike-slip fault with the normal component in the seismically active rift zone. Given that its vicinities represent an area with high population density, the emphasis needs to be placed primarily on the study of its structural features. At this, the Angara fault has been poorly studied by geophysical methods. Results of the specialized mapping carried out in the 1990s revealed the block structure of the Angara fault zone, however without a reliable identification of the fault plane, which leaves its position still to be debatable. To establish the Angara fault plane and studying its deep structure, the integration of such geophysical methods as magnetotelluric (MT) sounding, radon emanation and fieldwalking magnetic surveys was required. Their application in the study of the deep structure of the southern parts of the Angara fault allowed revealing anomalies in all of the measured fields, accordingly. The anomaly-forming object, which the authors associate with the deep penetrated Angara fault plane, was expressed in the most distinct way by the magnetotelluric data (as a high-resistivity region (ER = 8500 Ohm·m) relative to the host rock) and radon emanation survey (radon volumetric activity index RAI ≥ 20). The fact that the magnetic field received only minor distortions from the object may indicate either moderate magnetic characteristics of the latter or a significant occurrence depth. The identified anomaly-forming object localized within the crystalline basement tends to be more sharply expressed in the left bank of the Irkutsk Reservoir, while in the upper part of the cross-section it is overprinted by rocks of the sedimentary cover.

Numerical simulation is performed for a cylinder-bound two-component liquid flow. Simulation model is based on the method of lattice Boltzmann equations (LBM). The collision integral in this model is defined from the MRT approximation. The interaction between liquid components is described by the diffusion interface model with the pseudopotentials approximation. The main deficiency of this known approach is disbalance for discrete forces of two-component interaction; this would generate a pseudo-current in the transition zone. The presented numerical study offers a qualitative view for the pseudopotential function providing a smallest value for intercomponent interaction coefficient. This means the low pseudo-currents and the smallest size for the diffusive transition. The example simulation is presented for a problem of rotation of two components in a cylinder. The simulation gives also the Reynolds number rage and the cylinder aspect ratio that ensure the start of flow recirculation at the cylinder axis. It was demonstrated that simulation results comply with experimental data with a high accuracy.

Results of numerical investigations of the characteristics of a turbulent boundary layer in the case of air injection through a smooth flat perforated surface with a single hole and also through a similar surface with a group of staggered holes 0.18 mm in diameter (d/δ) in a low-velocity flow are reported. The Reynolds number Re** based on the momentum thickness δ^** ahead of the perforated region is 2600. The blowing coefficient C_b is varied in the interval from zero to 0.0438. The influence of some geometric parameters, in particular, the distance between the hole centers, on the properties of the transverse shear flow for identical intensities of blowing in situations with one hole and with a group of holes is analyzed. All observations reveal stable reduction of local friction whose value varies depending on the number of holes and their arrangement on the surface.

An experimental study of heat transfer and hydraulic losses in a channel with one wall being a surface with trench dimple, was carried out. The working surface had four rows of dimples located alternately at angles of 45° and -45° to the channel axis. In the laminar regime, the transfer of heat and the losses of pressure turned out to be close to the parameters of a smooth channel. In the turbulent regime, a 1.5-fold intensification of heat transfer with respect to the transfer of heat in a smooth channel was obtained. The dependence of the increase in pressure losses on the Reynolds number qualitatively agreeing with the dependence for the channels with sandy roughness is obtained.

The experimental results on the effect of longitudinal ribs on the antitorque moment for Couette-Taylor flow between two rotating cylinders are presented. The tangential Reynolds number in the experiments was varied by varying the cylinder speed and the working fluid viscosity (water-glycerin solution). The experiments covered laminar, transient and turbulent flow regimes (Re = 200 - 1·10⁵). It is shown that the ribs have an amplifying effect on the drag torque and mechanical energy dissipation only in the region of small Reynolds numbers (Re < 2000) in the laminar regime and in the presence of Taylor vortices in the gap. The intensification effect can reach two and more times and is caused by intensive turbulence of the flow by longitudinal ribs. In the turbulent regime, the heat release intensification is not observed, which is confirmed by the data available in the literature.

A nonisobaric supersonic jet of vibrationally excited carbon dioxide exhausting from converging axisymmetric nozzles with the diameter ranging in a wide interval (from 0.03 to 114 mm) is studied experimentally and numerically. Numerical simulations are performed within the framework of the two-temperature approach with the use of the Landau-Teller relaxation equation for each vibrational mode of carbon dioxide molecules. The simulations reveal that vibrational nonequilibrium of molecules affects the gas-dynamic structure of the jets in the temperature range of 300 - 900 K, and this effect is verified experimentally. Vibrational excitation of molecules in the experiment is ensured by means of gas heating. The effect of vibrational nonequilibrium is manifested as reduction of the amplitude of the static pressure in wave structure cells and as reduction of the longitudinal size and number of wave structure cells as compared to the case of an equilibrium supersonic flow. It is shown that the maximum effect of nonequilibrium is observed in jets exhausting from the nozzle with a diameter of ≅ 3 mm.

The modern aviation industry has many applications for honeycomb composite panels (HCP). The HCP-manufactured product line becomes more extended. This dictates a need for most effective and inexpensive methods for nondestructive inspection for HCP integrity that can ensure a high level of flight safety. One of promising methods for nondestructive inspection is the thermal technique. This paper presents and analyses the method feasibility of revealing the delamination of outer skin from an HCP filling. This task is performed by numerical simulation and the paper presents a pictorial test with a sample of HCP typical for aircraft engineering. Our results demonstrate how the thermal imaging tools can be used for the fact of skin delamination with account for technical restrictions found in real experiments with a physical sample of HCP.

The paper presents the results of experimental study of disturbances generated by an electric discharge. Tthe disturbances occur in the zone of interaction of a shock wave and a boundary layer (the income shock wave has the Mach number М = 1.43). Experiments were carried out in a supersonic wind tunnel with the unit Reynolds number Re₁ = 11×10⁶ 1/m. The flow velocity was measured using the PIV method and hot wire method. The artificial disturbances are generated by a periodic pulsed electric charge; the charge facility is allocated at the model surface upstream the interaction zone. The discharge time is less than 100 ns: this enables creating a wide-spectrum disturbance inside the boundary layer. The method of phase-synchronous measurement with the ensemble averaging for realization produces the spatial and temporal characteristics of disturbances generated in the interaction zone. The major growth of initial disturbances occurs in the shear layer behind the shock wave/boundary layer interaction zone (here the flow is turbulent).

In the present paper, a computational study of the influence of solar and thermal radiation on the formation of wind and temperature conditions in urban environment is carried out using the example of a region of Krasnoyarsk in winter. For calculations, a developed microscale mathematical model of urban atmosphere was used. The calculation results showed that the presence of radiation in the daytime leads to an increase in temperature and average speed of wind, as well as to the formation of an unsteady wind regime in the urban environment.

Nonlinear waves in a rectilinear rivulet flowing down a vertical plate are investigated on the basis of the developed semi-analytical model. The characteristics of nonlinear quasi-two-dimensional steady-state traveling waves are obtained numerically. Another wave family (the family of double-humped waves), branching off from the first family by doubling the spatial period, is found for small values of the wave number. It is shown that steady-state traveling waves do not exist in a certain narrow range of the excitation frequency, but a pulsating wave mode is realized.

The paper considers experimental data on the dynamics of superfluid helium in a U-shaped cylindrical channel. An experimental cell and a methodology for investigations, parameter measuring and obtained data processing are described. When a heat flux is applied near the heater, vapor can appear, and the interfacial surface executes regular oscillations of macroscopic amplitude with a constant frequency. The dependences of the interfacial surface position and the corresponding parameters on time are given. The obtained experimental results are interpreted based on the earlier obtained analytical solution.

The effect of barodiffusion on the dynamics of gas bubble growth in a highly viscous, gas-saturated magmatic melt undergoing rapid decompression is studied. A mathematical model of the process, which represents a joint dynamic and diffusion problem, is proposed. It is shown that as the bubble grows, a diffusive boundary layer is formed around it, leading to the appearance of a large viscosity gradient in the melt and, as a consequence, to a large pressure gradient. A semi-analytical solution of the problem based on the existence of a quasi-stationary state for the bubble growth process is found. It is shown that the effect of barodiffusion is significant at the initial and transient stages of the process. Its influence decreases with time and disappears completely at the stage of diffusion.

The published data are considered, and the technological aspects of a promising industrial process for the chlorine-free production of alkoxysilanes from silicon dioxide are analysed. Particular attention is paid to key issues that have not yet been considered in the literature. It is shown that the raw material base for the synthesis of alkoxysilanes can be expanded at the expense of microsilica, waste from the production of silicon and ferrosilicon. It has been experimentally confirmed that potassium hydroxide used as a catalyst for the synthesis of alkoxysilanes can be recovered and returned to the process. It has been established that the products of tetramethoxysilane (Si(OMe)₄) synthesis from silicon dioxide and dimethyl carbonate contain 55 components (among them, 45 high-boiling ones have not been identified). The main impurities in the reaction products are MeOH, CH₂O, MeOMe, and (MeO)₃SiOSi(OMe)₃. Technological prospects for the process of obtaining Si(OMe)₄ from industrial wastes are considered.

The regularities of ethoxylation of benzoic acid derivatives during interaction with polyethylene glycol through mechanochemical solid-phase synthesis in a vibrating apparatus have been studied. The conditions for carrying out mechanochemical reactions to increase the conversion degree of initial reagents into reaction products are analysed. The products of ethoxylation are characterized by IR spectroscopy, acid-base potentiometric titration, tensiometry, and dilatational rheology. It has been established that the degree of starting reagents conversion into ethoxylation products depends on the nature of the substituent and its position in the benzene ring. The degree of conversion into reaction products is higher for ortho-substituted derivatives of benzoic acid. It is shown that the salts of ethoxylated derivatives of benzoic acid exhibit pronounced surfactant properties at the air - solution interface.

The distribution of the 1^st hazard class substances and trace elements in the natural waters of the Novosibirsk urban agglomeration is investigated. A substantial role in water pollution is played in the study area not only by a large number of vehicles but also industrial enterprises. The composition of natural waters is determined as mainly hydrocarbonate calcium and hydrocarbonate calcium-magnesium, with total dissolved solids varying from 127 to 910 mg/dm³, and silicon concentration 0.14-11.61 mg/dm³. The geochemical setting changes from reducing (Eh -164.3 mV) to oxidizing (Eh 442.1 mV), pH 6.9-8.8 with O₂(sol.) content 0.48-20.28 mg/dm³. Within the city of Novosibirsk, excesses of background values for 33 elements were revealed; the concentrations of the first hazard class substances are, mg/dm³: Be (6.4·10^-6)-(1.4·10^-4), As 0.0003-0.26, Hg (8.33·10^-7)-(2.3·10^-4), Tl (6.2·10^-7)-(8.2·10^-5), U (1.3·10^-5)-0.21. The activity of radon, established in the natural waters of the city of Novosibirsk, varies from 1 to 1570 Bq/dm³. The waters under active anthropogenic load are mainly the river waters of the Inya, the Eltsovka the 2^nd, the Plyushchikha, the Eltsovka, the Kamyshenka, and the Ob. In groundwater samples, excesses over the actual normative documents and maximum permissible levels were revealed in the well in Kirov settlement (Mn - by a factor of 14, Fe - 10, As - 5), and in the Topol Gardeners Non-Commercial Partnership (Mn - by a factor of 59, Fe - 94, and As - 27).

The analysis of the developed classification schemes of forest hunting grounds is given. Previously, forest typology was taken as a basis with a 4-level division (category-class-group of types-type). The authors adhere to this scheme, but give environment-forming arguments and criteria for their selection. An analysis of the main literature on the classification of forest hunting grounds shows the evolution of the classification of natural resources from the use of available information (forest planning materials) to the specific assessment of productivity displayed on satellite images. Any thematic interpretation of the natural basis does not correspond to the tasks of hunting management. Animals are mobile, and the forest environment is dynamic, so the classification of hunting grounds should take into account the spatial and successional factors in the formation of habitat conditions. The proposed scheme takes into account at the level of the range the action of climatic (zonal, altitudinal-zone), population-ecological (forage, protective and nesting) and population dynamics-succession (dynamics of stands) factors. When hunting planning, the already available materials of forest planning and former hunting planning are taken into account, but the thematic interpretation of the original information must be also considered. A direct interpretation of the ecological properties of the image of hunting grounds from satellite images is proposed, and the developed classification scheme of the dynamic state makes it possible to predict their successional productivity and the level of animal abundance. Therefore, one should focus on obtaining direct information about hunting grounds using high-resolution satellite imagery.

Preserving the integrity of forests after logging and fires involves the development of various methods to promote natural reforestation. One of these methods is the creation of environmentally friendly and safe biofertilizers based on waste from the timber industry. The use of innovative biofertilizer in the Pogorelsky Bor (pine forest) of the Krasnoyarsk forest-steppe had a positive effect on the biopotential of soils and the amount of Scotch pine ( Pinus sylvestris L.) undergrowth after selective felling. In the first two years, in all experimental variants, an increase in the activity of hydrolytic and redox enzymes of the soil by 1.5-2 times was noted; they increased compared to the control. Immediately after the introduction of biofertilizer in the soil microbial complex, the amount of cellulolytics increases to 62 thousand CFU/g of soil in the logging areas. By the end of the growing season, both in the first and in the second year of application of biofertilizer in the experimental variant of the logging, sprouts of Scots pine were recorded 2-3 times more than in the control variant of this site. The fire that took place in May 2022 led to an increase in the total number of microorganisms up to 38 million CFU/g of soil and an increase in the activity of a number of hydrolytic enzymes during the growing season in experimental plots using biofertilizer. At the end of the growing season in 2022, there was no response of microorganisms to the application of biofertilizer, and actinomycetes dominated in the soil microbial complex. Also, by September of this year, the cellulose-decomposing potential, humification, and the activity of hydrolytic and redox enzymes decreased by more than 2 times. Biofertilizer significantly stimulated the formation of shoots and undergrowth of pine in the post-fire areas of the technological areas of felling (logging sites and portage) by 2 times.

This work is devoted to the study of evapotranspiration in the landscape complexes of the northern macroslope of the Western Sayan. Article summarizes literature and authors’ data on evapotranspiration obtained at experimental watersheds in the basin of the river Kebezh, on one of which in the 70s, as an experiment, 50 % of the forest area in the watershed has been cut down. Calculations of the total evaporation of phytocenoses at the basin level has been made, taking into account the altitudinal zonality. To calculate evapotranspiration at the study sites, field data obtained as a result of silvicultural and geobotanical studies and hydrological observations were used. Based on interpretation of remote sensing images and the use of digital elevation model, classification of landscape-hydrological complexes for the basins of the Kebezh and Taigish rivers was carried out, for which the components of evapotranspiration were calculated. The results showed that evapotranspiration in the dark coniferous taiga of the Western Sayan is an important component of the water balance and a significant proportion is the unproductive consumption of moisture for the evaporation of precipitation intercepted by tree crowns. It has also been established that the structure of evapotranspiration changes along the altitudinal zones in accordance with the vertical differentiation of climatic parameters and vegetation productivity. Estimated evapotranspiration data for various landscape-hydrological complexes made it possible to an indirect estimates of their contribution to the formation of runoff in river basins. This study can serve as a theoretical guide for landscape hydrological studies in the temperate cool zone.

Due to the observed climatic shifts, the problem of an adequate assessment of the carbon depositing capacity of forests and its possible climate-related changes is being actualized. To achieve optimal plant productivity, a certain proportionality between its constituent organs must be ensured, which depends, among other things, on the relative amount of biomass in these organs. In contrast to the theories of metabolic scaling and adaptive mass distribution, the study performed is associated with a concept based on non-Gaussian distributions. Using published data on biomass of 4515 trees of forest-forming coniferous genera of Eurasia, a new concept of ranking biomass fractions based on a modified Zipf-Pareto model is presented. Since the stem and branches of the tree perform the same function in its architectonics, namely, the implementation of xylem and phloem transport and the maintenance of the assimilation apparatus of the tree in the canopy space, we combine these two components into one common block when ranking biomasses. Since the 1-year-old seedling has no branches, and the needles are attached directly to its stem (the axis of the initial sprout), combining the biomasses of the stem and branches into a single block allowed us to consider the dynamics of the distribution of biomasses in the plant in the total age range, from seedlings to mature trees. Having accepted the ranking of biomasses in the sequence: stem plus branches, roots and needles, we established a positive relationship of the biomass with its rank at the initial stage of plant growth. As the plant grows, the named positive relationship changes its sign and becomes negative one. The presented regularity is confirmed statistically at the level of p<0.999. The change of the sign of the coefficient of competition for a resource occurs in all the genera in a fairly narrow age range between 2 and 7 years.

The results of a study of seed productivity and sowing qualities of seeds on forest seed objects of the Siberian stone pine ( Pinus sibirica Du Tour) in the Pyzhinsky Forestry Compartment of the Turochaksky Forestry District of the Republic of Altai are discussed in the article. The objects of the studies were forest seed orchards of the first order and permanent forest seed plots of improved origin, created in 1980-1988 by seedlings of a plus trees on the area of 22.8 hectares. Evaluation of seed productivity and seed quality was carried out in the average-yield’s year by standard methods. The average seed yield was 31 kg/ha, varying by objects from 8 to 73, the size of the cones was 7.0 × 5.4 cm, varying from 4.5 × 4.0 to 9.0 × 6.0 cm. The main contribution to the variability of yield indicators is determined by the age, which at the time of the studies was 27-34 years. So far, the yield of seeds from cones and the viability of seeds are reduced somewhat in comparison with natural stands. The highest yield (73 kg/ha) and viability of seeds (87 %) is in the most mature forest seed orchard. Based on the dependence of the yield on age, a forecast was made that the forest seed orchard will achieve the natural Siberian stone pine forests of Altai’s seed productivity (150 kg/ha) to the age of 50. The least variable traits are the sizes of cones and seeds and their shape indices (variation coefficients are about 9-10 %). Intermediate and rather unstable reproduced on various objects are the coefficients of variation of seed viability (5-58 %). Obviously, this is due to differences in the efficiency of pollination due to different ages of stands. The greatest variability is typical for weight and counting traits - from 30 to 200 % or more.

The results of a study of the relationship between forest survey indicators and a condition indicators with the size of trees in diameter and their relative height are presented with the possible use of the latter in assessing the state of even-aged, high-density, pure composition pine forest stands of Zatyumenskiy ecological park in the city of Tyumen. It has been revealed, that 6-13 % of the total number of trees in the sample plots falls on the share of small-diameter trees. At the same time, the timber stock of such trees does not exceed 4 % of the total growing stock. Large-diameter trees account for 18-36 % of the total number of trees and 30-50 % of the total timber stock in the sample plots. In terms of indicators such as tree health and relative vitality, relative height and growth stress coefficient, small-diameter trees, in most cases, are characterized as severely weakened, dying and biologically unstable. At the same time, large and medium-sized trees are considered as healthy or weakened, but biologically stable. The average indicators of the general state of the tree stand are significantly negatively affected by the presence of small-diameter trees, in most cases, very weakened and dying. A general pattern of deterioration in the state of the tree stand with an increase in recreational impact has been revealed. It has been established that weakened trees with a relative height H/D < 100 are characterized by the smallest diameters, and their number and timber stock increase with an increase in recreational impact. Based on the results of the studies, a number of forestry measures have been proposed to increase the biological stability, recreational attractiveness and protective functions of the studied pine forests.

The study of the wood quality in the drained pine stand was carried out on the territory of the north taiga of Arkhangelsk Oblast, which belongs to the green zone of the city of Arkhangelsk and the Arctic zone of the Russian Federation. Repeated measurements of forest inventory parameters were carried out on 6 permanent sample plots affected by melioration since 1974 and reconstruction of the drainage network in 1990. Before drainage, a swampy pine stands of the V^b bonitet class grew on them. At present, medium-aged scots pine ( Pinus sylvestris L.) stands of shrubby-sphagnum forest type, IV bonitet class, grow on the drained area. For half of the plots, it is possible to recommend thinning according to the current Russian Rules of forest care (2020). Some of the trees meet the requirements for the aviation lumber wood quality. For a visual simultaneous analysis of the drainage network quality impact, the location of objects relative to the drainage network and the air temperature in abnormally hot years, diagrams of changes in the average indicators of the width of the annual increment and the wood density in the drained pine stands by year are constructed. Similar diagrams are constructed on the basis of measuring the model tree cores at different relative heights of the trunk. This analytical approach has been applied for the first time. It is suggested that in 10 years the inventory parameters of all facilities will meet the requirements for the thinning purpose, and the wood quality will increase on average, for which it is recommended to reconstruct the channels.

The results of studies on the adaptation of arctic bramble ( Rubus arcticus L.) plants of Astra and Sofia cultivars obtained by the clonal micropropagation method to non-sterile ex vitro conditions using the hydroponic method of cultivation are discussed in the article. The arctic bramble is a highly valuable species of forest berry plants in food and medicinal relations, rarely found and having a low yield in natural conditions. Adaptation to non-sterile ex vitro conditions is one of the limiting stages in clonal micropropagation. The survival rate of regenerated plants of arctic bramble of the studied cultivars in the conditions of a hydroponic system is 98 %, 1 month after planting in open ground - 69 %. Regenerated plants have stronger differences in morphometric parameters between clones within a cultivar than between cultivars. The arctic bramble planted in conglomerates formed shoots in the amount of 5.0 pcs. with an average length of 2.5 cm on the 20th day of adaptation. On the 45th day of arctic bramble plants after division into separate shoots had an average of 3.0 pcs. shoots with an average length of 8.3 cm. The arctic bramble plants of the Sofia cultivar have higher morphometric parameters of the above-ground and root systems compared to the Astra cultivar on the 45th day of cultivation in a hydroponic system: by the number of roots - by 30.3 %, by the total length of the roots - by 23 %, by the number of leaves - by 20 %, by the number of shoots - by 14 %, by the length of the shoots - by 10 %. The indicators of the development of the root system on a hydroponic installation depended on the varietal characteristics and the growing period. The arctic bramble plants have roots 10-20 cm long and shoot growths of 20-30 cm after 2 months of adaptation, which indicates its suitability for planting in open ground conditions.

Data on the interannual dynamics of the seasonal thawing depth in the dominant landscapes of typical tundra at the Marre-Sale geocryological station (western coast of the Yamal Peninsula) are presented. It is shown that drained landscapes have the maximum response to changes in climatic conditions, while wet and boggy landscapes are characterized by the reduced rates of increase in the active layer depth. The slow increase in the depth of seasonal thaw during the current climate warming is explained by the presence of an ice-rich horizon in the upper part of permafrost, thaw subsidence, and an increase in the height of the moss cover. The uneven growth of vegetation, primarily mosses, creates considerable contrasts in the spatial distribution of the active layer depth. For a regional assessment of the thawing depth, the use of its mean weighted value with due account for the share of each landscape in the entire landscape structure of the region is recommended.

Hydrochemical monitoring of inland waters makes it possible to obtain information about their state and to assess the influence of climatic factors on the regime of water reservoirs. In the recent decade, relevance of the research related to the impact of permafrost thaw on the state of small lakes in the Arctic has been growing. The influence of interannual fluctuations in air temperature and precipitation on the ionic composition of lakes has been statistically established for the contents of NO₂, SO₄, and NO₃ ions. Active thermodenudation on the shores of these lakes increases water mineralization levels by an average of 42.8 % and changes the concentrations of major ions Na, Ca, Mg, K, PO₄, and HCO₃.

A study of permafrost and groundwater conditions of the Mahatta Tukulan, Sakha Republic (Yakutia), where thick aquifer talik horizons are common, was carried out. During the first half of July 2021, the water discharge of the Mugur-Taryn Spring was 690 L/s, which is less compared to data from 1973-1974 (770-930 L/s). Current data confirm that the chemical composition of suprapermafrost and interpermafrost groundwater has been stable over the past several decades in the studied sand massifs. The chemical composition of these spring waters is calcium-magnesium bicarbonate, with mineralization of 13-50 mg/dm³. Using field observation data and results of remote sensing data processing, it was determined that the area of the sand massif with a vegetation cover has increased by approximately 18 % during the past 40-50 years. This has led to a decrease in soil temperature, a change in the water heat balance of the massif, and a reduction of water reserves of talik aquifers.

The article offers an analytical solution to the problem of operation of deep seasonal cooling devices (deep SCD) based on the assumption of quasi-stationary regime of soil freezing by the system evaporator. The case of application of the proposed solution for one of the design configurations of a deep SCD on thawed soils with different thermal conductivity under the weather conditions of Salekhard city is considered. We obtained the values of the radius of soil freezing around the evaporator tube as a function of depth at different time intervals of system operation. The present analytical model can be easily applied at the design stage to evaluate and optimize the design of the applied thermal stabilization system in particular geocryological zones for different thermophysical characteristics of soils, taking into account the aggregate state of water in them.

The work is aimed at the theoretical development and modeling of field experiments for a high-resolution geophysical technique of transient electromagnetic sounding in order to substantiate a permafrost monitoring technology. To select the optimal parameters of the sounding system, we established the dynamics of changes in the registered electromotive force in terms of the distance between the signal transmitter and receiver. Based on field temperature measurements at the geophysical test site and the elucidated interrelation between the electrical resistivity and temperature values, we calculated the variations in the resistivity of the near-surface loams and clay loams for the period late January - early April 2022. The dynamics of changes in the boundary between seasonally frozen and underlying rocks was traced. Using the resistivity values calculated from the measured temperatures, we carried out numerical modeling of the electromotive force amplitude to identify the dependence of the signals on the shift of the boundary due to freezing. In addition, approaches were proposed to verification of the results obtained.

In the first decades of the 21st century, the need of changing the paradigm of cryology became obvious. This changing is based on two main approaches. One of them is related to transition from considering the cryosphere as a threat for people to its interpretation as one of the key resources for environmental basis and subsistence. The second approach is based on the need to build a holistic image of the Earth’s cryosphere. Considering the Earth’s cryosphere as a complex system, consisting of cold layers of atmosphere, glaciosphere and subterranean permafrost, brings us to the need for analysis of previous terms identifying object areas that study the world of cold. Ideas about the cryosphere and cryology were formulated in 1974. Modern interpretation of the object and the subject of research was the result of many long-term disputes. Currently, the term “geocryology” remains to be used as a synonym for science of permafrost. However, while building a holistic image of the Earth’s cryosphere, it is necessary to take into account the properties and state of the entire object as a whole and create new terms and concepts that can reflect the expanding contexts of studying cryogenic processes, their ontological hierarchy, system connections, etc. In this situation, the philosophy of science is designed to become a kind of source of generation of new images, concepts, and meanings.

This paper describes the milestones in the scientific career and outreach activities of Vladimir Romanovich Alekseev, an outstanding researcher of Siberian nature. V.R. Alekseev, Professor, Doctor of Geography, Merited Scientist of the Russian Federation, is a principal researcher at the Melnikov Permafrost Institute and an honorary member of the Russian Geographical Society.

This paper describes the milestones in the scientific and pedagogical activity of one of the outstanding scientists in the field of permafrost engineering L.N. Khrustalev, Honored Inventor of the Komi ASSR, Merited Scientist of the Russian Federation, Doctor of Technical Sciences, Honored Professor of Lomonosov Moscow State University.